1 /* Fold a constant sub-tree into a single node for C-compiler
2 Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
3 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 2, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to the Free
20 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
23 /*@@ This file should be rewritten to use an arbitrary precision
24 @@ representation for "struct tree_int_cst" and "struct tree_real_cst".
25 @@ Perhaps the routines could also be used for bc/dc, and made a lib.
26 @@ The routines that translate from the ap rep should
27 @@ warn if precision et. al. is lost.
28 @@ This would also make life easier when this technology is used
29 @@ for cross-compilers. */
31 /* The entry points in this file are fold, size_int_wide, size_binop
34 fold takes a tree as argument and returns a simplified tree.
36 size_binop takes a tree code for an arithmetic operation
37 and two operands that are trees, and produces a tree for the
38 result, assuming the type comes from `sizetype'.
40 size_int takes an integer value, and creates a tree constant
41 with type from `sizetype'.
43 force_fit_type takes a constant, an overflowable flag and prior
44 overflow indicators. It forces the value to fit the type and sets
45 TREE_OVERFLOW and TREE_CONSTANT_OVERFLOW as appropriate. */
49 #include "coretypes.h"
61 #include "langhooks.h"
64 /* Non-zero if we are folding constants inside an initializer; zero
66 int folding_initializer = 0;
68 /* The following constants represent a bit based encoding of GCC's
69 comparison operators. This encoding simplifies transformations
70 on relational comparison operators, such as AND and OR. */
71 enum comparison_code {
90 static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
91 static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
92 static bool negate_mathfn_p (enum built_in_function);
93 static bool negate_expr_p (tree);
94 static tree negate_expr (tree);
95 static tree split_tree (tree, enum tree_code, tree *, tree *, tree *, int);
96 static tree associate_trees (tree, tree, enum tree_code, tree);
97 static tree const_binop (enum tree_code, tree, tree, int);
98 static enum comparison_code comparison_to_compcode (enum tree_code);
99 static enum tree_code compcode_to_comparison (enum comparison_code);
100 static tree combine_comparisons (enum tree_code, enum tree_code,
101 enum tree_code, tree, tree, tree);
102 static int truth_value_p (enum tree_code);
103 static int operand_equal_for_comparison_p (tree, tree, tree);
104 static int twoval_comparison_p (tree, tree *, tree *, int *);
105 static tree eval_subst (tree, tree, tree, tree, tree);
106 static tree pedantic_omit_one_operand (tree, tree, tree);
107 static tree distribute_bit_expr (enum tree_code, tree, tree, tree);
108 static tree make_bit_field_ref (tree, tree, int, int, int);
109 static tree optimize_bit_field_compare (enum tree_code, tree, tree, tree);
110 static tree decode_field_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
111 enum machine_mode *, int *, int *,
113 static int all_ones_mask_p (tree, int);
114 static tree sign_bit_p (tree, tree);
115 static int simple_operand_p (tree);
116 static tree range_binop (enum tree_code, tree, tree, int, tree, int);
117 static tree range_predecessor (tree);
118 static tree range_successor (tree);
119 static tree make_range (tree, int *, tree *, tree *, bool *);
120 static tree build_range_check (tree, tree, int, tree, tree);
121 static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
123 static tree fold_range_test (enum tree_code, tree, tree, tree);
124 static tree fold_cond_expr_with_comparison (tree, tree, tree, tree);
125 static tree unextend (tree, int, int, tree);
126 static tree fold_truthop (enum tree_code, tree, tree, tree);
127 static tree optimize_minmax_comparison (enum tree_code, tree, tree, tree);
128 static tree extract_muldiv (tree, tree, enum tree_code, tree, bool *);
129 static tree extract_muldiv_1 (tree, tree, enum tree_code, tree, bool *);
130 static int multiple_of_p (tree, tree, tree);
131 static tree fold_binary_op_with_conditional_arg (enum tree_code, tree,
134 static bool fold_real_zero_addition_p (tree, tree, int);
135 static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
137 static tree fold_inf_compare (enum tree_code, tree, tree, tree);
138 static tree fold_div_compare (enum tree_code, tree, tree, tree);
139 static bool reorder_operands_p (tree, tree);
140 static tree fold_negate_const (tree, tree);
141 static tree fold_not_const (tree, tree);
142 static tree fold_relational_const (enum tree_code, tree, tree, tree);
143 static int native_encode_expr (tree, unsigned char *, int);
144 static tree native_interpret_expr (tree, unsigned char *, int);
147 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
148 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
149 and SUM1. Then this yields nonzero if overflow occurred during the
152 Overflow occurs if A and B have the same sign, but A and SUM differ in
153 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
155 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
157 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
158 We do that by representing the two-word integer in 4 words, with only
159 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
160 number. The value of the word is LOWPART + HIGHPART * BASE. */
163 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
164 #define HIGHPART(x) \
165 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
166 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
168 /* Unpack a two-word integer into 4 words.
169 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
170 WORDS points to the array of HOST_WIDE_INTs. */
173 encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
175 words[0] = LOWPART (low);
176 words[1] = HIGHPART (low);
177 words[2] = LOWPART (hi);
178 words[3] = HIGHPART (hi);
181 /* Pack an array of 4 words into a two-word integer.
182 WORDS points to the array of words.
183 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
186 decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
189 *low = words[0] + words[1] * BASE;
190 *hi = words[2] + words[3] * BASE;
193 /* T is an INT_CST node. OVERFLOWABLE indicates if we are interested
194 in overflow of the value, when >0 we are only interested in signed
195 overflow, for <0 we are interested in any overflow. OVERFLOWED
196 indicates whether overflow has already occurred. CONST_OVERFLOWED
197 indicates whether constant overflow has already occurred. We force
198 T's value to be within range of T's type (by setting to 0 or 1 all
199 the bits outside the type's range). We set TREE_OVERFLOWED if,
200 OVERFLOWED is nonzero,
201 or OVERFLOWABLE is >0 and signed overflow occurs
202 or OVERFLOWABLE is <0 and any overflow occurs
203 We set TREE_CONSTANT_OVERFLOWED if,
204 CONST_OVERFLOWED is nonzero
205 or we set TREE_OVERFLOWED.
206 We return either the original T, or a copy. */
209 force_fit_type (tree t, int overflowable,
210 bool overflowed, bool overflowed_const)
212 unsigned HOST_WIDE_INT low;
215 int sign_extended_type;
217 gcc_assert (TREE_CODE (t) == INTEGER_CST);
219 low = TREE_INT_CST_LOW (t);
220 high = TREE_INT_CST_HIGH (t);
222 if (POINTER_TYPE_P (TREE_TYPE (t))
223 || TREE_CODE (TREE_TYPE (t)) == OFFSET_TYPE)
226 prec = TYPE_PRECISION (TREE_TYPE (t));
227 /* Size types *are* sign extended. */
228 sign_extended_type = (!TYPE_UNSIGNED (TREE_TYPE (t))
229 || (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
230 && TYPE_IS_SIZETYPE (TREE_TYPE (t))));
232 /* First clear all bits that are beyond the type's precision. */
234 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
236 else if (prec > HOST_BITS_PER_WIDE_INT)
237 high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
241 if (prec < HOST_BITS_PER_WIDE_INT)
242 low &= ~((HOST_WIDE_INT) (-1) << prec);
245 if (!sign_extended_type)
246 /* No sign extension */;
247 else if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
248 /* Correct width already. */;
249 else if (prec > HOST_BITS_PER_WIDE_INT)
251 /* Sign extend top half? */
252 if (high & ((unsigned HOST_WIDE_INT)1
253 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
254 high |= (HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT);
256 else if (prec == HOST_BITS_PER_WIDE_INT)
258 if ((HOST_WIDE_INT)low < 0)
263 /* Sign extend bottom half? */
264 if (low & ((unsigned HOST_WIDE_INT)1 << (prec - 1)))
267 low |= (HOST_WIDE_INT)(-1) << prec;
271 /* If the value changed, return a new node. */
272 if (overflowed || overflowed_const
273 || low != TREE_INT_CST_LOW (t) || high != TREE_INT_CST_HIGH (t))
275 t = build_int_cst_wide (TREE_TYPE (t), low, high);
279 || (overflowable > 0 && sign_extended_type))
282 TREE_OVERFLOW (t) = 1;
283 TREE_CONSTANT_OVERFLOW (t) = 1;
285 else if (overflowed_const)
288 TREE_CONSTANT_OVERFLOW (t) = 1;
295 /* Add two doubleword integers with doubleword result.
296 Return nonzero if the operation overflows according to UNSIGNED_P.
297 Each argument is given as two `HOST_WIDE_INT' pieces.
298 One argument is L1 and H1; the other, L2 and H2.
299 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
302 add_double_with_sign (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
303 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
304 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
307 unsigned HOST_WIDE_INT l;
311 h = h1 + h2 + (l < l1);
317 return (unsigned HOST_WIDE_INT) h < (unsigned HOST_WIDE_INT) h1;
319 return OVERFLOW_SUM_SIGN (h1, h2, h);
322 /* Negate a doubleword integer with doubleword result.
323 Return nonzero if the operation overflows, assuming it's signed.
324 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
325 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
328 neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
329 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
335 return (*hv & h1) < 0;
345 /* Multiply two doubleword integers with doubleword result.
346 Return nonzero if the operation overflows according to UNSIGNED_P.
347 Each argument is given as two `HOST_WIDE_INT' pieces.
348 One argument is L1 and H1; the other, L2 and H2.
349 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
352 mul_double_with_sign (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
353 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
354 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
357 HOST_WIDE_INT arg1[4];
358 HOST_WIDE_INT arg2[4];
359 HOST_WIDE_INT prod[4 * 2];
360 unsigned HOST_WIDE_INT carry;
362 unsigned HOST_WIDE_INT toplow, neglow;
363 HOST_WIDE_INT tophigh, neghigh;
365 encode (arg1, l1, h1);
366 encode (arg2, l2, h2);
368 memset (prod, 0, sizeof prod);
370 for (i = 0; i < 4; i++)
373 for (j = 0; j < 4; j++)
376 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
377 carry += arg1[i] * arg2[j];
378 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
380 prod[k] = LOWPART (carry);
381 carry = HIGHPART (carry);
386 decode (prod, lv, hv);
387 decode (prod + 4, &toplow, &tophigh);
389 /* Unsigned overflow is immediate. */
391 return (toplow | tophigh) != 0;
393 /* Check for signed overflow by calculating the signed representation of the
394 top half of the result; it should agree with the low half's sign bit. */
397 neg_double (l2, h2, &neglow, &neghigh);
398 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
402 neg_double (l1, h1, &neglow, &neghigh);
403 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
405 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
408 /* Shift the doubleword integer in L1, H1 left by COUNT places
409 keeping only PREC bits of result.
410 Shift right if COUNT is negative.
411 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
412 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
415 lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
416 HOST_WIDE_INT count, unsigned int prec,
417 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
419 unsigned HOST_WIDE_INT signmask;
423 rshift_double (l1, h1, -count, prec, lv, hv, arith);
427 if (SHIFT_COUNT_TRUNCATED)
430 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
432 /* Shifting by the host word size is undefined according to the
433 ANSI standard, so we must handle this as a special case. */
437 else if (count >= HOST_BITS_PER_WIDE_INT)
439 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
444 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
445 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
449 /* Sign extend all bits that are beyond the precision. */
451 signmask = -((prec > HOST_BITS_PER_WIDE_INT
452 ? ((unsigned HOST_WIDE_INT) *hv
453 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
454 : (*lv >> (prec - 1))) & 1);
456 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
458 else if (prec >= HOST_BITS_PER_WIDE_INT)
460 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
461 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
466 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
467 *lv |= signmask << prec;
471 /* Shift the doubleword integer in L1, H1 right by COUNT places
472 keeping only PREC bits of result. COUNT must be positive.
473 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
474 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
477 rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
478 HOST_WIDE_INT count, unsigned int prec,
479 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
482 unsigned HOST_WIDE_INT signmask;
485 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
488 if (SHIFT_COUNT_TRUNCATED)
491 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
493 /* Shifting by the host word size is undefined according to the
494 ANSI standard, so we must handle this as a special case. */
498 else if (count >= HOST_BITS_PER_WIDE_INT)
501 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
505 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
507 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
510 /* Zero / sign extend all bits that are beyond the precision. */
512 if (count >= (HOST_WIDE_INT)prec)
517 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
519 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
521 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
522 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
527 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
528 *lv |= signmask << (prec - count);
532 /* Rotate the doubleword integer in L1, H1 left by COUNT places
533 keeping only PREC bits of result.
534 Rotate right if COUNT is negative.
535 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
538 lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
539 HOST_WIDE_INT count, unsigned int prec,
540 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
542 unsigned HOST_WIDE_INT s1l, s2l;
543 HOST_WIDE_INT s1h, s2h;
549 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
550 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
555 /* Rotate the doubleword integer in L1, H1 left by COUNT places
556 keeping only PREC bits of result. COUNT must be positive.
557 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
560 rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
561 HOST_WIDE_INT count, unsigned int prec,
562 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
564 unsigned HOST_WIDE_INT s1l, s2l;
565 HOST_WIDE_INT s1h, s2h;
571 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
572 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
577 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
578 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
579 CODE is a tree code for a kind of division, one of
580 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
582 It controls how the quotient is rounded to an integer.
583 Return nonzero if the operation overflows.
584 UNS nonzero says do unsigned division. */
587 div_and_round_double (enum tree_code code, int uns,
588 unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
589 HOST_WIDE_INT hnum_orig,
590 unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
591 HOST_WIDE_INT hden_orig,
592 unsigned HOST_WIDE_INT *lquo,
593 HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
597 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
598 HOST_WIDE_INT den[4], quo[4];
600 unsigned HOST_WIDE_INT work;
601 unsigned HOST_WIDE_INT carry = 0;
602 unsigned HOST_WIDE_INT lnum = lnum_orig;
603 HOST_WIDE_INT hnum = hnum_orig;
604 unsigned HOST_WIDE_INT lden = lden_orig;
605 HOST_WIDE_INT hden = hden_orig;
608 if (hden == 0 && lden == 0)
609 overflow = 1, lden = 1;
611 /* Calculate quotient sign and convert operands to unsigned. */
617 /* (minimum integer) / (-1) is the only overflow case. */
618 if (neg_double (lnum, hnum, &lnum, &hnum)
619 && ((HOST_WIDE_INT) lden & hden) == -1)
625 neg_double (lden, hden, &lden, &hden);
629 if (hnum == 0 && hden == 0)
630 { /* single precision */
632 /* This unsigned division rounds toward zero. */
638 { /* trivial case: dividend < divisor */
639 /* hden != 0 already checked. */
646 memset (quo, 0, sizeof quo);
648 memset (num, 0, sizeof num); /* to zero 9th element */
649 memset (den, 0, sizeof den);
651 encode (num, lnum, hnum);
652 encode (den, lden, hden);
654 /* Special code for when the divisor < BASE. */
655 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
657 /* hnum != 0 already checked. */
658 for (i = 4 - 1; i >= 0; i--)
660 work = num[i] + carry * BASE;
661 quo[i] = work / lden;
667 /* Full double precision division,
668 with thanks to Don Knuth's "Seminumerical Algorithms". */
669 int num_hi_sig, den_hi_sig;
670 unsigned HOST_WIDE_INT quo_est, scale;
672 /* Find the highest nonzero divisor digit. */
673 for (i = 4 - 1;; i--)
680 /* Insure that the first digit of the divisor is at least BASE/2.
681 This is required by the quotient digit estimation algorithm. */
683 scale = BASE / (den[den_hi_sig] + 1);
685 { /* scale divisor and dividend */
687 for (i = 0; i <= 4 - 1; i++)
689 work = (num[i] * scale) + carry;
690 num[i] = LOWPART (work);
691 carry = HIGHPART (work);
696 for (i = 0; i <= 4 - 1; i++)
698 work = (den[i] * scale) + carry;
699 den[i] = LOWPART (work);
700 carry = HIGHPART (work);
701 if (den[i] != 0) den_hi_sig = i;
708 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
710 /* Guess the next quotient digit, quo_est, by dividing the first
711 two remaining dividend digits by the high order quotient digit.
712 quo_est is never low and is at most 2 high. */
713 unsigned HOST_WIDE_INT tmp;
715 num_hi_sig = i + den_hi_sig + 1;
716 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
717 if (num[num_hi_sig] != den[den_hi_sig])
718 quo_est = work / den[den_hi_sig];
722 /* Refine quo_est so it's usually correct, and at most one high. */
723 tmp = work - quo_est * den[den_hi_sig];
725 && (den[den_hi_sig - 1] * quo_est
726 > (tmp * BASE + num[num_hi_sig - 2])))
729 /* Try QUO_EST as the quotient digit, by multiplying the
730 divisor by QUO_EST and subtracting from the remaining dividend.
731 Keep in mind that QUO_EST is the I - 1st digit. */
734 for (j = 0; j <= den_hi_sig; j++)
736 work = quo_est * den[j] + carry;
737 carry = HIGHPART (work);
738 work = num[i + j] - LOWPART (work);
739 num[i + j] = LOWPART (work);
740 carry += HIGHPART (work) != 0;
743 /* If quo_est was high by one, then num[i] went negative and
744 we need to correct things. */
745 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
748 carry = 0; /* add divisor back in */
749 for (j = 0; j <= den_hi_sig; j++)
751 work = num[i + j] + den[j] + carry;
752 carry = HIGHPART (work);
753 num[i + j] = LOWPART (work);
756 num [num_hi_sig] += carry;
759 /* Store the quotient digit. */
764 decode (quo, lquo, hquo);
767 /* If result is negative, make it so. */
769 neg_double (*lquo, *hquo, lquo, hquo);
771 /* Compute trial remainder: rem = num - (quo * den) */
772 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
773 neg_double (*lrem, *hrem, lrem, hrem);
774 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
779 case TRUNC_MOD_EXPR: /* round toward zero */
780 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
784 case FLOOR_MOD_EXPR: /* round toward negative infinity */
785 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
788 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
796 case CEIL_MOD_EXPR: /* round toward positive infinity */
797 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
799 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
807 case ROUND_MOD_EXPR: /* round to closest integer */
809 unsigned HOST_WIDE_INT labs_rem = *lrem;
810 HOST_WIDE_INT habs_rem = *hrem;
811 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
812 HOST_WIDE_INT habs_den = hden, htwice;
814 /* Get absolute values. */
816 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
818 neg_double (lden, hden, &labs_den, &habs_den);
820 /* If (2 * abs (lrem) >= abs (lden)) */
821 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
822 labs_rem, habs_rem, <wice, &htwice);
824 if (((unsigned HOST_WIDE_INT) habs_den
825 < (unsigned HOST_WIDE_INT) htwice)
826 || (((unsigned HOST_WIDE_INT) habs_den
827 == (unsigned HOST_WIDE_INT) htwice)
828 && (labs_den < ltwice)))
832 add_double (*lquo, *hquo,
833 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
836 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
848 /* Compute true remainder: rem = num - (quo * den) */
849 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
850 neg_double (*lrem, *hrem, lrem, hrem);
851 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
855 /* If ARG2 divides ARG1 with zero remainder, carries out the division
856 of type CODE and returns the quotient.
857 Otherwise returns NULL_TREE. */
860 div_if_zero_remainder (enum tree_code code, tree arg1, tree arg2)
862 unsigned HOST_WIDE_INT int1l, int2l;
863 HOST_WIDE_INT int1h, int2h;
864 unsigned HOST_WIDE_INT quol, reml;
865 HOST_WIDE_INT quoh, remh;
866 tree type = TREE_TYPE (arg1);
867 int uns = TYPE_UNSIGNED (type);
869 int1l = TREE_INT_CST_LOW (arg1);
870 int1h = TREE_INT_CST_HIGH (arg1);
871 int2l = TREE_INT_CST_LOW (arg2);
872 int2h = TREE_INT_CST_HIGH (arg2);
874 div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
875 &quol, &quoh, &reml, &remh);
876 if (remh != 0 || reml != 0)
879 return build_int_cst_wide (type, quol, quoh);
882 /* This is non-zero if we should defer warnings about undefined
883 overflow. This facility exists because these warnings are a
884 special case. The code to estimate loop iterations does not want
885 to issue any warnings, since it works with expressions which do not
886 occur in user code. Various bits of cleanup code call fold(), but
887 only use the result if it has certain characteristics (e.g., is a
888 constant); that code only wants to issue a warning if the result is
891 static int fold_deferring_overflow_warnings;
893 /* If a warning about undefined overflow is deferred, this is the
894 warning. Note that this may cause us to turn two warnings into
895 one, but that is fine since it is sufficient to only give one
896 warning per expression. */
898 static const char* fold_deferred_overflow_warning;
900 /* If a warning about undefined overflow is deferred, this is the
901 level at which the warning should be emitted. */
903 static enum warn_strict_overflow_code fold_deferred_overflow_code;
905 /* Start deferring overflow warnings. We could use a stack here to
906 permit nested calls, but at present it is not necessary. */
909 fold_defer_overflow_warnings (void)
911 ++fold_deferring_overflow_warnings;
914 /* Stop deferring overflow warnings. If there is a pending warning,
915 and ISSUE is true, then issue the warning if appropriate. STMT is
916 the statement with which the warning should be associated (used for
917 location information); STMT may be NULL. CODE is the level of the
918 warning--a warn_strict_overflow_code value. This function will use
919 the smaller of CODE and the deferred code when deciding whether to
920 issue the warning. CODE may be zero to mean to always use the
924 fold_undefer_overflow_warnings (bool issue, tree stmt, int code)
929 gcc_assert (fold_deferring_overflow_warnings > 0);
930 --fold_deferring_overflow_warnings;
931 if (fold_deferring_overflow_warnings > 0)
933 if (fold_deferred_overflow_warning != NULL
935 && code < (int) fold_deferred_overflow_code)
936 fold_deferred_overflow_code = code;
940 warnmsg = fold_deferred_overflow_warning;
941 fold_deferred_overflow_warning = NULL;
943 if (!issue || warnmsg == NULL)
946 /* Use the smallest code level when deciding to issue the
948 if (code == 0 || code > (int) fold_deferred_overflow_code)
949 code = fold_deferred_overflow_code;
951 if (!issue_strict_overflow_warning (code))
954 if (stmt == NULL_TREE || !EXPR_HAS_LOCATION (stmt))
955 locus = input_location;
957 locus = EXPR_LOCATION (stmt);
958 warning (OPT_Wstrict_overflow, "%H%s", &locus, warnmsg);
961 /* Stop deferring overflow warnings, ignoring any deferred
965 fold_undefer_and_ignore_overflow_warnings (void)
967 fold_undefer_overflow_warnings (false, NULL_TREE, 0);
970 /* Whether we are deferring overflow warnings. */
973 fold_deferring_overflow_warnings_p (void)
975 return fold_deferring_overflow_warnings > 0;
978 /* This is called when we fold something based on the fact that signed
979 overflow is undefined. */
982 fold_overflow_warning (const char* gmsgid, enum warn_strict_overflow_code wc)
984 gcc_assert (!flag_wrapv && !flag_trapv);
985 if (fold_deferring_overflow_warnings > 0)
987 if (fold_deferred_overflow_warning == NULL
988 || wc < fold_deferred_overflow_code)
990 fold_deferred_overflow_warning = gmsgid;
991 fold_deferred_overflow_code = wc;
994 else if (issue_strict_overflow_warning (wc))
995 warning (OPT_Wstrict_overflow, gmsgid);
998 /* Return true if the built-in mathematical function specified by CODE
999 is odd, i.e. -f(x) == f(-x). */
1002 negate_mathfn_p (enum built_in_function code)
1006 CASE_FLT_FN (BUILT_IN_ASIN):
1007 CASE_FLT_FN (BUILT_IN_ASINH):
1008 CASE_FLT_FN (BUILT_IN_ATAN):
1009 CASE_FLT_FN (BUILT_IN_ATANH):
1010 CASE_FLT_FN (BUILT_IN_CBRT):
1011 CASE_FLT_FN (BUILT_IN_SIN):
1012 CASE_FLT_FN (BUILT_IN_SINH):
1013 CASE_FLT_FN (BUILT_IN_TAN):
1014 CASE_FLT_FN (BUILT_IN_TANH):
1023 /* Check whether we may negate an integer constant T without causing
1027 may_negate_without_overflow_p (tree t)
1029 unsigned HOST_WIDE_INT val;
1033 gcc_assert (TREE_CODE (t) == INTEGER_CST);
1035 type = TREE_TYPE (t);
1036 if (TYPE_UNSIGNED (type))
1039 prec = TYPE_PRECISION (type);
1040 if (prec > HOST_BITS_PER_WIDE_INT)
1042 if (TREE_INT_CST_LOW (t) != 0)
1044 prec -= HOST_BITS_PER_WIDE_INT;
1045 val = TREE_INT_CST_HIGH (t);
1048 val = TREE_INT_CST_LOW (t);
1049 if (prec < HOST_BITS_PER_WIDE_INT)
1050 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
1051 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
1054 /* Determine whether an expression T can be cheaply negated using
1055 the function negate_expr without introducing undefined overflow. */
1058 negate_expr_p (tree t)
1065 type = TREE_TYPE (t);
1067 STRIP_SIGN_NOPS (t);
1068 switch (TREE_CODE (t))
1071 if (TYPE_OVERFLOW_WRAPS (type))
1074 /* Check that -CST will not overflow type. */
1075 return may_negate_without_overflow_p (t);
1077 return (INTEGRAL_TYPE_P (type)
1078 && TYPE_OVERFLOW_WRAPS (type));
1085 return negate_expr_p (TREE_REALPART (t))
1086 && negate_expr_p (TREE_IMAGPART (t));
1089 if (FLOAT_TYPE_P (type) && !flag_unsafe_math_optimizations)
1091 /* -(A + B) -> (-B) - A. */
1092 if (negate_expr_p (TREE_OPERAND (t, 1))
1093 && reorder_operands_p (TREE_OPERAND (t, 0),
1094 TREE_OPERAND (t, 1)))
1096 /* -(A + B) -> (-A) - B. */
1097 return negate_expr_p (TREE_OPERAND (t, 0));
1100 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
1101 return (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1102 && reorder_operands_p (TREE_OPERAND (t, 0),
1103 TREE_OPERAND (t, 1));
1106 if (TYPE_UNSIGNED (TREE_TYPE (t)))
1112 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
1113 return negate_expr_p (TREE_OPERAND (t, 1))
1114 || negate_expr_p (TREE_OPERAND (t, 0));
1117 case TRUNC_DIV_EXPR:
1118 case ROUND_DIV_EXPR:
1119 case FLOOR_DIV_EXPR:
1121 case EXACT_DIV_EXPR:
1122 /* In general we can't negate A / B, because if A is INT_MIN and
1123 B is 1, we may turn this into INT_MIN / -1 which is undefined
1124 and actually traps on some architectures. But if overflow is
1125 undefined, we can negate, because - (INT_MIN / 1) is an
1127 if (INTEGRAL_TYPE_P (TREE_TYPE (t))
1128 && !TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t)))
1130 return negate_expr_p (TREE_OPERAND (t, 1))
1131 || negate_expr_p (TREE_OPERAND (t, 0));
1134 /* Negate -((double)float) as (double)(-float). */
1135 if (TREE_CODE (type) == REAL_TYPE)
1137 tree tem = strip_float_extensions (t);
1139 return negate_expr_p (tem);
1144 /* Negate -f(x) as f(-x). */
1145 if (negate_mathfn_p (builtin_mathfn_code (t)))
1146 return negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1)));
1150 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1151 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1153 tree op1 = TREE_OPERAND (t, 1);
1154 if (TREE_INT_CST_HIGH (op1) == 0
1155 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1156 == TREE_INT_CST_LOW (op1))
1167 /* Given T, an expression, return a folded tree for -T or NULL_TREE, if no
1168 simplification is possible.
1169 If negate_expr_p would return true for T, NULL_TREE will never be
1173 fold_negate_expr (tree t)
1175 tree type = TREE_TYPE (t);
1178 switch (TREE_CODE (t))
1180 /* Convert - (~A) to A + 1. */
1182 if (INTEGRAL_TYPE_P (type))
1183 return fold_build2 (PLUS_EXPR, type, TREE_OPERAND (t, 0),
1184 build_int_cst (type, 1));
1188 tem = fold_negate_const (t, type);
1189 if (!TREE_OVERFLOW (tem)
1190 || !TYPE_OVERFLOW_TRAPS (type))
1195 tem = fold_negate_const (t, type);
1196 /* Two's complement FP formats, such as c4x, may overflow. */
1197 if (! TREE_OVERFLOW (tem) || ! flag_trapping_math)
1203 tree rpart = negate_expr (TREE_REALPART (t));
1204 tree ipart = negate_expr (TREE_IMAGPART (t));
1206 if ((TREE_CODE (rpart) == REAL_CST
1207 && TREE_CODE (ipart) == REAL_CST)
1208 || (TREE_CODE (rpart) == INTEGER_CST
1209 && TREE_CODE (ipart) == INTEGER_CST))
1210 return build_complex (type, rpart, ipart);
1215 return TREE_OPERAND (t, 0);
1218 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1220 /* -(A + B) -> (-B) - A. */
1221 if (negate_expr_p (TREE_OPERAND (t, 1))
1222 && reorder_operands_p (TREE_OPERAND (t, 0),
1223 TREE_OPERAND (t, 1)))
1225 tem = negate_expr (TREE_OPERAND (t, 1));
1226 return fold_build2 (MINUS_EXPR, type,
1227 tem, TREE_OPERAND (t, 0));
1230 /* -(A + B) -> (-A) - B. */
1231 if (negate_expr_p (TREE_OPERAND (t, 0)))
1233 tem = negate_expr (TREE_OPERAND (t, 0));
1234 return fold_build2 (MINUS_EXPR, type,
1235 tem, TREE_OPERAND (t, 1));
1241 /* - (A - B) -> B - A */
1242 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1243 && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
1244 return fold_build2 (MINUS_EXPR, type,
1245 TREE_OPERAND (t, 1), TREE_OPERAND (t, 0));
1249 if (TYPE_UNSIGNED (type))
1255 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type)))
1257 tem = TREE_OPERAND (t, 1);
1258 if (negate_expr_p (tem))
1259 return fold_build2 (TREE_CODE (t), type,
1260 TREE_OPERAND (t, 0), negate_expr (tem));
1261 tem = TREE_OPERAND (t, 0);
1262 if (negate_expr_p (tem))
1263 return fold_build2 (TREE_CODE (t), type,
1264 negate_expr (tem), TREE_OPERAND (t, 1));
1268 case TRUNC_DIV_EXPR:
1269 case ROUND_DIV_EXPR:
1270 case FLOOR_DIV_EXPR:
1272 case EXACT_DIV_EXPR:
1273 /* In general we can't negate A / B, because if A is INT_MIN and
1274 B is 1, we may turn this into INT_MIN / -1 which is undefined
1275 and actually traps on some architectures. But if overflow is
1276 undefined, we can negate, because - (INT_MIN / 1) is an
1278 if (!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
1280 const char * const warnmsg = G_("assuming signed overflow does not "
1281 "occur when negating a division");
1282 tem = TREE_OPERAND (t, 1);
1283 if (negate_expr_p (tem))
1285 if (INTEGRAL_TYPE_P (type)
1286 && (TREE_CODE (tem) != INTEGER_CST
1287 || integer_onep (tem)))
1288 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
1289 return fold_build2 (TREE_CODE (t), type,
1290 TREE_OPERAND (t, 0), negate_expr (tem));
1292 tem = TREE_OPERAND (t, 0);
1293 if (negate_expr_p (tem))
1295 if (INTEGRAL_TYPE_P (type)
1296 && (TREE_CODE (tem) != INTEGER_CST
1297 || tree_int_cst_equal (tem, TYPE_MIN_VALUE (type))))
1298 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
1299 return fold_build2 (TREE_CODE (t), type,
1300 negate_expr (tem), TREE_OPERAND (t, 1));
1306 /* Convert -((double)float) into (double)(-float). */
1307 if (TREE_CODE (type) == REAL_TYPE)
1309 tem = strip_float_extensions (t);
1310 if (tem != t && negate_expr_p (tem))
1311 return negate_expr (tem);
1316 /* Negate -f(x) as f(-x). */
1317 if (negate_mathfn_p (builtin_mathfn_code (t))
1318 && negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1))))
1320 tree fndecl, arg, arglist;
1322 fndecl = get_callee_fndecl (t);
1323 arg = negate_expr (TREE_VALUE (TREE_OPERAND (t, 1)));
1324 arglist = build_tree_list (NULL_TREE, arg);
1325 return build_function_call_expr (fndecl, arglist);
1330 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1331 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1333 tree op1 = TREE_OPERAND (t, 1);
1334 if (TREE_INT_CST_HIGH (op1) == 0
1335 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1336 == TREE_INT_CST_LOW (op1))
1338 tree ntype = TYPE_UNSIGNED (type)
1339 ? lang_hooks.types.signed_type (type)
1340 : lang_hooks.types.unsigned_type (type);
1341 tree temp = fold_convert (ntype, TREE_OPERAND (t, 0));
1342 temp = fold_build2 (RSHIFT_EXPR, ntype, temp, op1);
1343 return fold_convert (type, temp);
1355 /* Like fold_negate_expr, but return a NEGATE_EXPR tree, if T can not be
1356 negated in a simpler way. Also allow for T to be NULL_TREE, in which case
1357 return NULL_TREE. */
1360 negate_expr (tree t)
1367 type = TREE_TYPE (t);
1368 STRIP_SIGN_NOPS (t);
1370 tem = fold_negate_expr (t);
1372 tem = build1 (NEGATE_EXPR, TREE_TYPE (t), t);
1373 return fold_convert (type, tem);
1376 /* Split a tree IN into a constant, literal and variable parts that could be
1377 combined with CODE to make IN. "constant" means an expression with
1378 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1379 commutative arithmetic operation. Store the constant part into *CONP,
1380 the literal in *LITP and return the variable part. If a part isn't
1381 present, set it to null. If the tree does not decompose in this way,
1382 return the entire tree as the variable part and the other parts as null.
1384 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1385 case, we negate an operand that was subtracted. Except if it is a
1386 literal for which we use *MINUS_LITP instead.
1388 If NEGATE_P is true, we are negating all of IN, again except a literal
1389 for which we use *MINUS_LITP instead.
1391 If IN is itself a literal or constant, return it as appropriate.
1393 Note that we do not guarantee that any of the three values will be the
1394 same type as IN, but they will have the same signedness and mode. */
1397 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
1398 tree *minus_litp, int negate_p)
1406 /* Strip any conversions that don't change the machine mode or signedness. */
1407 STRIP_SIGN_NOPS (in);
1409 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
1411 else if (TREE_CODE (in) == code
1412 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1413 /* We can associate addition and subtraction together (even
1414 though the C standard doesn't say so) for integers because
1415 the value is not affected. For reals, the value might be
1416 affected, so we can't. */
1417 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1418 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1420 tree op0 = TREE_OPERAND (in, 0);
1421 tree op1 = TREE_OPERAND (in, 1);
1422 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1423 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1425 /* First see if either of the operands is a literal, then a constant. */
1426 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
1427 *litp = op0, op0 = 0;
1428 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
1429 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1431 if (op0 != 0 && TREE_CONSTANT (op0))
1432 *conp = op0, op0 = 0;
1433 else if (op1 != 0 && TREE_CONSTANT (op1))
1434 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1436 /* If we haven't dealt with either operand, this is not a case we can
1437 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1438 if (op0 != 0 && op1 != 0)
1443 var = op1, neg_var_p = neg1_p;
1445 /* Now do any needed negations. */
1447 *minus_litp = *litp, *litp = 0;
1449 *conp = negate_expr (*conp);
1451 var = negate_expr (var);
1453 else if (TREE_CONSTANT (in))
1461 *minus_litp = *litp, *litp = 0;
1462 else if (*minus_litp)
1463 *litp = *minus_litp, *minus_litp = 0;
1464 *conp = negate_expr (*conp);
1465 var = negate_expr (var);
1471 /* Re-associate trees split by the above function. T1 and T2 are either
1472 expressions to associate or null. Return the new expression, if any. If
1473 we build an operation, do it in TYPE and with CODE. */
1476 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1483 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1484 try to fold this since we will have infinite recursion. But do
1485 deal with any NEGATE_EXPRs. */
1486 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1487 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1489 if (code == PLUS_EXPR)
1491 if (TREE_CODE (t1) == NEGATE_EXPR)
1492 return build2 (MINUS_EXPR, type, fold_convert (type, t2),
1493 fold_convert (type, TREE_OPERAND (t1, 0)));
1494 else if (TREE_CODE (t2) == NEGATE_EXPR)
1495 return build2 (MINUS_EXPR, type, fold_convert (type, t1),
1496 fold_convert (type, TREE_OPERAND (t2, 0)));
1497 else if (integer_zerop (t2))
1498 return fold_convert (type, t1);
1500 else if (code == MINUS_EXPR)
1502 if (integer_zerop (t2))
1503 return fold_convert (type, t1);
1506 return build2 (code, type, fold_convert (type, t1),
1507 fold_convert (type, t2));
1510 return fold_build2 (code, type, fold_convert (type, t1),
1511 fold_convert (type, t2));
1514 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1515 to produce a new constant. Return NULL_TREE if we don't know how
1516 to evaluate CODE at compile-time.
1518 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1521 int_const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1523 unsigned HOST_WIDE_INT int1l, int2l;
1524 HOST_WIDE_INT int1h, int2h;
1525 unsigned HOST_WIDE_INT low;
1527 unsigned HOST_WIDE_INT garbagel;
1528 HOST_WIDE_INT garbageh;
1530 tree type = TREE_TYPE (arg1);
1531 int uns = TYPE_UNSIGNED (type);
1533 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1536 int1l = TREE_INT_CST_LOW (arg1);
1537 int1h = TREE_INT_CST_HIGH (arg1);
1538 int2l = TREE_INT_CST_LOW (arg2);
1539 int2h = TREE_INT_CST_HIGH (arg2);
1544 low = int1l | int2l, hi = int1h | int2h;
1548 low = int1l ^ int2l, hi = int1h ^ int2h;
1552 low = int1l & int2l, hi = int1h & int2h;
1558 /* It's unclear from the C standard whether shifts can overflow.
1559 The following code ignores overflow; perhaps a C standard
1560 interpretation ruling is needed. */
1561 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1568 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1573 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1577 neg_double (int2l, int2h, &low, &hi);
1578 add_double (int1l, int1h, low, hi, &low, &hi);
1579 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1583 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1586 case TRUNC_DIV_EXPR:
1587 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1588 case EXACT_DIV_EXPR:
1589 /* This is a shortcut for a common special case. */
1590 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1591 && ! TREE_CONSTANT_OVERFLOW (arg1)
1592 && ! TREE_CONSTANT_OVERFLOW (arg2)
1593 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1595 if (code == CEIL_DIV_EXPR)
1598 low = int1l / int2l, hi = 0;
1602 /* ... fall through ... */
1604 case ROUND_DIV_EXPR:
1605 if (int2h == 0 && int2l == 0)
1607 if (int2h == 0 && int2l == 1)
1609 low = int1l, hi = int1h;
1612 if (int1l == int2l && int1h == int2h
1613 && ! (int1l == 0 && int1h == 0))
1618 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1619 &low, &hi, &garbagel, &garbageh);
1622 case TRUNC_MOD_EXPR:
1623 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1624 /* This is a shortcut for a common special case. */
1625 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1626 && ! TREE_CONSTANT_OVERFLOW (arg1)
1627 && ! TREE_CONSTANT_OVERFLOW (arg2)
1628 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1630 if (code == CEIL_MOD_EXPR)
1632 low = int1l % int2l, hi = 0;
1636 /* ... fall through ... */
1638 case ROUND_MOD_EXPR:
1639 if (int2h == 0 && int2l == 0)
1641 overflow = div_and_round_double (code, uns,
1642 int1l, int1h, int2l, int2h,
1643 &garbagel, &garbageh, &low, &hi);
1649 low = (((unsigned HOST_WIDE_INT) int1h
1650 < (unsigned HOST_WIDE_INT) int2h)
1651 || (((unsigned HOST_WIDE_INT) int1h
1652 == (unsigned HOST_WIDE_INT) int2h)
1655 low = (int1h < int2h
1656 || (int1h == int2h && int1l < int2l));
1658 if (low == (code == MIN_EXPR))
1659 low = int1l, hi = int1h;
1661 low = int2l, hi = int2h;
1668 t = build_int_cst_wide (TREE_TYPE (arg1), low, hi);
1672 /* Propagate overflow flags ourselves. */
1673 if (((!uns || is_sizetype) && overflow)
1674 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1677 TREE_OVERFLOW (t) = 1;
1678 TREE_CONSTANT_OVERFLOW (t) = 1;
1680 else if (TREE_CONSTANT_OVERFLOW (arg1) | TREE_CONSTANT_OVERFLOW (arg2))
1683 TREE_CONSTANT_OVERFLOW (t) = 1;
1687 t = force_fit_type (t, 1,
1688 ((!uns || is_sizetype) && overflow)
1689 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2),
1690 TREE_CONSTANT_OVERFLOW (arg1)
1691 | TREE_CONSTANT_OVERFLOW (arg2));
1696 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1697 constant. We assume ARG1 and ARG2 have the same data type, or at least
1698 are the same kind of constant and the same machine mode. Return zero if
1699 combining the constants is not allowed in the current operating mode.
1701 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1704 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1706 /* Sanity check for the recursive cases. */
1713 if (TREE_CODE (arg1) == INTEGER_CST)
1714 return int_const_binop (code, arg1, arg2, notrunc);
1716 if (TREE_CODE (arg1) == REAL_CST)
1718 enum machine_mode mode;
1721 REAL_VALUE_TYPE value;
1722 REAL_VALUE_TYPE result;
1726 /* The following codes are handled by real_arithmetic. */
1741 d1 = TREE_REAL_CST (arg1);
1742 d2 = TREE_REAL_CST (arg2);
1744 type = TREE_TYPE (arg1);
1745 mode = TYPE_MODE (type);
1747 /* Don't perform operation if we honor signaling NaNs and
1748 either operand is a NaN. */
1749 if (HONOR_SNANS (mode)
1750 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1753 /* Don't perform operation if it would raise a division
1754 by zero exception. */
1755 if (code == RDIV_EXPR
1756 && REAL_VALUES_EQUAL (d2, dconst0)
1757 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1760 /* If either operand is a NaN, just return it. Otherwise, set up
1761 for floating-point trap; we return an overflow. */
1762 if (REAL_VALUE_ISNAN (d1))
1764 else if (REAL_VALUE_ISNAN (d2))
1767 inexact = real_arithmetic (&value, code, &d1, &d2);
1768 real_convert (&result, mode, &value);
1770 /* Don't constant fold this floating point operation if
1771 the result has overflowed and flag_trapping_math. */
1772 if (flag_trapping_math
1773 && MODE_HAS_INFINITIES (mode)
1774 && REAL_VALUE_ISINF (result)
1775 && !REAL_VALUE_ISINF (d1)
1776 && !REAL_VALUE_ISINF (d2))
1779 /* Don't constant fold this floating point operation if the
1780 result may dependent upon the run-time rounding mode and
1781 flag_rounding_math is set, or if GCC's software emulation
1782 is unable to accurately represent the result. */
1783 if ((flag_rounding_math
1784 || (REAL_MODE_FORMAT_COMPOSITE_P (mode)
1785 && !flag_unsafe_math_optimizations))
1786 && (inexact || !real_identical (&result, &value)))
1789 t = build_real (type, result);
1791 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2);
1792 TREE_CONSTANT_OVERFLOW (t)
1794 | TREE_CONSTANT_OVERFLOW (arg1)
1795 | TREE_CONSTANT_OVERFLOW (arg2);
1799 if (TREE_CODE (arg1) == COMPLEX_CST)
1801 tree type = TREE_TYPE (arg1);
1802 tree r1 = TREE_REALPART (arg1);
1803 tree i1 = TREE_IMAGPART (arg1);
1804 tree r2 = TREE_REALPART (arg2);
1805 tree i2 = TREE_IMAGPART (arg2);
1812 real = const_binop (code, r1, r2, notrunc);
1813 imag = const_binop (code, i1, i2, notrunc);
1817 real = const_binop (MINUS_EXPR,
1818 const_binop (MULT_EXPR, r1, r2, notrunc),
1819 const_binop (MULT_EXPR, i1, i2, notrunc),
1821 imag = const_binop (PLUS_EXPR,
1822 const_binop (MULT_EXPR, r1, i2, notrunc),
1823 const_binop (MULT_EXPR, i1, r2, notrunc),
1830 = const_binop (PLUS_EXPR,
1831 const_binop (MULT_EXPR, r2, r2, notrunc),
1832 const_binop (MULT_EXPR, i2, i2, notrunc),
1835 = const_binop (PLUS_EXPR,
1836 const_binop (MULT_EXPR, r1, r2, notrunc),
1837 const_binop (MULT_EXPR, i1, i2, notrunc),
1840 = const_binop (MINUS_EXPR,
1841 const_binop (MULT_EXPR, i1, r2, notrunc),
1842 const_binop (MULT_EXPR, r1, i2, notrunc),
1845 if (INTEGRAL_TYPE_P (TREE_TYPE (r1)))
1846 code = TRUNC_DIV_EXPR;
1848 real = const_binop (code, t1, magsquared, notrunc);
1849 imag = const_binop (code, t2, magsquared, notrunc);
1858 return build_complex (type, real, imag);
1864 /* Create a size type INT_CST node with NUMBER sign extended. KIND
1865 indicates which particular sizetype to create. */
1868 size_int_kind (HOST_WIDE_INT number, enum size_type_kind kind)
1870 return build_int_cst (sizetype_tab[(int) kind], number);
1873 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1874 is a tree code. The type of the result is taken from the operands.
1875 Both must be the same type integer type and it must be a size type.
1876 If the operands are constant, so is the result. */
1879 size_binop (enum tree_code code, tree arg0, tree arg1)
1881 tree type = TREE_TYPE (arg0);
1883 if (arg0 == error_mark_node || arg1 == error_mark_node)
1884 return error_mark_node;
1886 gcc_assert (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1887 && type == TREE_TYPE (arg1));
1889 /* Handle the special case of two integer constants faster. */
1890 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1892 /* And some specific cases even faster than that. */
1893 if (code == PLUS_EXPR && integer_zerop (arg0))
1895 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1896 && integer_zerop (arg1))
1898 else if (code == MULT_EXPR && integer_onep (arg0))
1901 /* Handle general case of two integer constants. */
1902 return int_const_binop (code, arg0, arg1, 0);
1905 return fold_build2 (code, type, arg0, arg1);
1908 /* Given two values, either both of sizetype or both of bitsizetype,
1909 compute the difference between the two values. Return the value
1910 in signed type corresponding to the type of the operands. */
1913 size_diffop (tree arg0, tree arg1)
1915 tree type = TREE_TYPE (arg0);
1918 gcc_assert (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1919 && type == TREE_TYPE (arg1));
1921 /* If the type is already signed, just do the simple thing. */
1922 if (!TYPE_UNSIGNED (type))
1923 return size_binop (MINUS_EXPR, arg0, arg1);
1925 ctype = type == bitsizetype ? sbitsizetype : ssizetype;
1927 /* If either operand is not a constant, do the conversions to the signed
1928 type and subtract. The hardware will do the right thing with any
1929 overflow in the subtraction. */
1930 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1931 return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
1932 fold_convert (ctype, arg1));
1934 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1935 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1936 overflow) and negate (which can't either). Special-case a result
1937 of zero while we're here. */
1938 if (tree_int_cst_equal (arg0, arg1))
1939 return build_int_cst (ctype, 0);
1940 else if (tree_int_cst_lt (arg1, arg0))
1941 return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1943 return size_binop (MINUS_EXPR, build_int_cst (ctype, 0),
1944 fold_convert (ctype, size_binop (MINUS_EXPR,
1948 /* A subroutine of fold_convert_const handling conversions of an
1949 INTEGER_CST to another integer type. */
1952 fold_convert_const_int_from_int (tree type, tree arg1)
1956 /* Given an integer constant, make new constant with new type,
1957 appropriately sign-extended or truncated. */
1958 t = build_int_cst_wide (type, TREE_INT_CST_LOW (arg1),
1959 TREE_INT_CST_HIGH (arg1));
1961 t = force_fit_type (t,
1962 /* Don't set the overflow when
1963 converting a pointer */
1964 !POINTER_TYPE_P (TREE_TYPE (arg1)),
1965 (TREE_INT_CST_HIGH (arg1) < 0
1966 && (TYPE_UNSIGNED (type)
1967 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
1968 | TREE_OVERFLOW (arg1),
1969 TREE_CONSTANT_OVERFLOW (arg1));
1974 /* A subroutine of fold_convert_const handling conversions a REAL_CST
1975 to an integer type. */
1978 fold_convert_const_int_from_real (enum tree_code code, tree type, tree arg1)
1983 /* The following code implements the floating point to integer
1984 conversion rules required by the Java Language Specification,
1985 that IEEE NaNs are mapped to zero and values that overflow
1986 the target precision saturate, i.e. values greater than
1987 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
1988 are mapped to INT_MIN. These semantics are allowed by the
1989 C and C++ standards that simply state that the behavior of
1990 FP-to-integer conversion is unspecified upon overflow. */
1992 HOST_WIDE_INT high, low;
1994 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
1998 case FIX_TRUNC_EXPR:
1999 real_trunc (&r, VOIDmode, &x);
2003 real_ceil (&r, VOIDmode, &x);
2006 case FIX_FLOOR_EXPR:
2007 real_floor (&r, VOIDmode, &x);
2010 case FIX_ROUND_EXPR:
2011 real_round (&r, VOIDmode, &x);
2018 /* If R is NaN, return zero and show we have an overflow. */
2019 if (REAL_VALUE_ISNAN (r))
2026 /* See if R is less than the lower bound or greater than the
2031 tree lt = TYPE_MIN_VALUE (type);
2032 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
2033 if (REAL_VALUES_LESS (r, l))
2036 high = TREE_INT_CST_HIGH (lt);
2037 low = TREE_INT_CST_LOW (lt);
2043 tree ut = TYPE_MAX_VALUE (type);
2046 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
2047 if (REAL_VALUES_LESS (u, r))
2050 high = TREE_INT_CST_HIGH (ut);
2051 low = TREE_INT_CST_LOW (ut);
2057 REAL_VALUE_TO_INT (&low, &high, r);
2059 t = build_int_cst_wide (type, low, high);
2061 t = force_fit_type (t, -1, overflow | TREE_OVERFLOW (arg1),
2062 TREE_CONSTANT_OVERFLOW (arg1));
2066 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2067 to another floating point type. */
2070 fold_convert_const_real_from_real (tree type, tree arg1)
2072 REAL_VALUE_TYPE value;
2075 real_convert (&value, TYPE_MODE (type), &TREE_REAL_CST (arg1));
2076 t = build_real (type, value);
2078 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
2079 TREE_CONSTANT_OVERFLOW (t)
2080 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2084 /* Attempt to fold type conversion operation CODE of expression ARG1 to
2085 type TYPE. If no simplification can be done return NULL_TREE. */
2088 fold_convert_const (enum tree_code code, tree type, tree arg1)
2090 if (TREE_TYPE (arg1) == type)
2093 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
2095 if (TREE_CODE (arg1) == INTEGER_CST)
2096 return fold_convert_const_int_from_int (type, arg1);
2097 else if (TREE_CODE (arg1) == REAL_CST)
2098 return fold_convert_const_int_from_real (code, type, arg1);
2100 else if (TREE_CODE (type) == REAL_TYPE)
2102 if (TREE_CODE (arg1) == INTEGER_CST)
2103 return build_real_from_int_cst (type, arg1);
2104 if (TREE_CODE (arg1) == REAL_CST)
2105 return fold_convert_const_real_from_real (type, arg1);
2110 /* Construct a vector of zero elements of vector type TYPE. */
2113 build_zero_vector (tree type)
2118 elem = fold_convert_const (NOP_EXPR, TREE_TYPE (type), integer_zero_node);
2119 units = TYPE_VECTOR_SUBPARTS (type);
2122 for (i = 0; i < units; i++)
2123 list = tree_cons (NULL_TREE, elem, list);
2124 return build_vector (type, list);
2127 /* Convert expression ARG to type TYPE. Used by the middle-end for
2128 simple conversions in preference to calling the front-end's convert. */
2131 fold_convert (tree type, tree arg)
2133 tree orig = TREE_TYPE (arg);
2139 if (TREE_CODE (arg) == ERROR_MARK
2140 || TREE_CODE (type) == ERROR_MARK
2141 || TREE_CODE (orig) == ERROR_MARK)
2142 return error_mark_node;
2144 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig)
2145 || lang_hooks.types_compatible_p (TYPE_MAIN_VARIANT (type),
2146 TYPE_MAIN_VARIANT (orig)))
2147 return fold_build1 (NOP_EXPR, type, arg);
2149 switch (TREE_CODE (type))
2151 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
2152 case POINTER_TYPE: case REFERENCE_TYPE:
2154 if (TREE_CODE (arg) == INTEGER_CST)
2156 tem = fold_convert_const (NOP_EXPR, type, arg);
2157 if (tem != NULL_TREE)
2160 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2161 || TREE_CODE (orig) == OFFSET_TYPE)
2162 return fold_build1 (NOP_EXPR, type, arg);
2163 if (TREE_CODE (orig) == COMPLEX_TYPE)
2165 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2166 return fold_convert (type, tem);
2168 gcc_assert (TREE_CODE (orig) == VECTOR_TYPE
2169 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2170 return fold_build1 (NOP_EXPR, type, arg);
2173 if (TREE_CODE (arg) == INTEGER_CST)
2175 tem = fold_convert_const (FLOAT_EXPR, type, arg);
2176 if (tem != NULL_TREE)
2179 else if (TREE_CODE (arg) == REAL_CST)
2181 tem = fold_convert_const (NOP_EXPR, type, arg);
2182 if (tem != NULL_TREE)
2186 switch (TREE_CODE (orig))
2189 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2190 case POINTER_TYPE: case REFERENCE_TYPE:
2191 return fold_build1 (FLOAT_EXPR, type, arg);
2194 return fold_build1 (NOP_EXPR, type, arg);
2197 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2198 return fold_convert (type, tem);
2205 switch (TREE_CODE (orig))
2208 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2209 case POINTER_TYPE: case REFERENCE_TYPE:
2211 return build2 (COMPLEX_EXPR, type,
2212 fold_convert (TREE_TYPE (type), arg),
2213 fold_convert (TREE_TYPE (type), integer_zero_node));
2218 if (TREE_CODE (arg) == COMPLEX_EXPR)
2220 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
2221 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
2222 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
2225 arg = save_expr (arg);
2226 rpart = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2227 ipart = fold_build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg);
2228 rpart = fold_convert (TREE_TYPE (type), rpart);
2229 ipart = fold_convert (TREE_TYPE (type), ipart);
2230 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
2238 if (integer_zerop (arg))
2239 return build_zero_vector (type);
2240 gcc_assert (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2241 gcc_assert (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2242 || TREE_CODE (orig) == VECTOR_TYPE);
2243 return fold_build1 (VIEW_CONVERT_EXPR, type, arg);
2246 return fold_build1 (NOP_EXPR, type, fold_ignored_result (arg));
2253 /* Return false if expr can be assumed not to be an lvalue, true
2257 maybe_lvalue_p (tree x)
2259 /* We only need to wrap lvalue tree codes. */
2260 switch (TREE_CODE (x))
2271 case ALIGN_INDIRECT_REF:
2272 case MISALIGNED_INDIRECT_REF:
2274 case ARRAY_RANGE_REF:
2280 case PREINCREMENT_EXPR:
2281 case PREDECREMENT_EXPR:
2283 case TRY_CATCH_EXPR:
2284 case WITH_CLEANUP_EXPR:
2295 /* Assume the worst for front-end tree codes. */
2296 if ((int)TREE_CODE (x) >= NUM_TREE_CODES)
2304 /* Return an expr equal to X but certainly not valid as an lvalue. */
2309 /* While we are in GIMPLE, NON_LVALUE_EXPR doesn't mean anything to
2314 if (! maybe_lvalue_p (x))
2316 return build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2319 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2320 Zero means allow extended lvalues. */
2322 int pedantic_lvalues;
2324 /* When pedantic, return an expr equal to X but certainly not valid as a
2325 pedantic lvalue. Otherwise, return X. */
2328 pedantic_non_lvalue (tree x)
2330 if (pedantic_lvalues)
2331 return non_lvalue (x);
2336 /* Given a tree comparison code, return the code that is the logical inverse
2337 of the given code. It is not safe to do this for floating-point
2338 comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
2339 as well: if reversing the comparison is unsafe, return ERROR_MARK. */
2342 invert_tree_comparison (enum tree_code code, bool honor_nans)
2344 if (honor_nans && flag_trapping_math)
2354 return honor_nans ? UNLE_EXPR : LE_EXPR;
2356 return honor_nans ? UNLT_EXPR : LT_EXPR;
2358 return honor_nans ? UNGE_EXPR : GE_EXPR;
2360 return honor_nans ? UNGT_EXPR : GT_EXPR;
2374 return UNORDERED_EXPR;
2375 case UNORDERED_EXPR:
2376 return ORDERED_EXPR;
2382 /* Similar, but return the comparison that results if the operands are
2383 swapped. This is safe for floating-point. */
2386 swap_tree_comparison (enum tree_code code)
2393 case UNORDERED_EXPR:
2419 /* Convert a comparison tree code from an enum tree_code representation
2420 into a compcode bit-based encoding. This function is the inverse of
2421 compcode_to_comparison. */
2423 static enum comparison_code
2424 comparison_to_compcode (enum tree_code code)
2441 return COMPCODE_ORD;
2442 case UNORDERED_EXPR:
2443 return COMPCODE_UNORD;
2445 return COMPCODE_UNLT;
2447 return COMPCODE_UNEQ;
2449 return COMPCODE_UNLE;
2451 return COMPCODE_UNGT;
2453 return COMPCODE_LTGT;
2455 return COMPCODE_UNGE;
2461 /* Convert a compcode bit-based encoding of a comparison operator back
2462 to GCC's enum tree_code representation. This function is the
2463 inverse of comparison_to_compcode. */
2465 static enum tree_code
2466 compcode_to_comparison (enum comparison_code code)
2483 return ORDERED_EXPR;
2484 case COMPCODE_UNORD:
2485 return UNORDERED_EXPR;
2503 /* Return a tree for the comparison which is the combination of
2504 doing the AND or OR (depending on CODE) of the two operations LCODE
2505 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2506 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2507 if this makes the transformation invalid. */
2510 combine_comparisons (enum tree_code code, enum tree_code lcode,
2511 enum tree_code rcode, tree truth_type,
2512 tree ll_arg, tree lr_arg)
2514 bool honor_nans = HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg)));
2515 enum comparison_code lcompcode = comparison_to_compcode (lcode);
2516 enum comparison_code rcompcode = comparison_to_compcode (rcode);
2517 enum comparison_code compcode;
2521 case TRUTH_AND_EXPR: case TRUTH_ANDIF_EXPR:
2522 compcode = lcompcode & rcompcode;
2525 case TRUTH_OR_EXPR: case TRUTH_ORIF_EXPR:
2526 compcode = lcompcode | rcompcode;
2535 /* Eliminate unordered comparisons, as well as LTGT and ORD
2536 which are not used unless the mode has NaNs. */
2537 compcode &= ~COMPCODE_UNORD;
2538 if (compcode == COMPCODE_LTGT)
2539 compcode = COMPCODE_NE;
2540 else if (compcode == COMPCODE_ORD)
2541 compcode = COMPCODE_TRUE;
2543 else if (flag_trapping_math)
2545 /* Check that the original operation and the optimized ones will trap
2546 under the same condition. */
2547 bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
2548 && (lcompcode != COMPCODE_EQ)
2549 && (lcompcode != COMPCODE_ORD);
2550 bool rtrap = (rcompcode & COMPCODE_UNORD) == 0
2551 && (rcompcode != COMPCODE_EQ)
2552 && (rcompcode != COMPCODE_ORD);
2553 bool trap = (compcode & COMPCODE_UNORD) == 0
2554 && (compcode != COMPCODE_EQ)
2555 && (compcode != COMPCODE_ORD);
2557 /* In a short-circuited boolean expression the LHS might be
2558 such that the RHS, if evaluated, will never trap. For
2559 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2560 if neither x nor y is NaN. (This is a mixed blessing: for
2561 example, the expression above will never trap, hence
2562 optimizing it to x < y would be invalid). */
2563 if ((code == TRUTH_ORIF_EXPR && (lcompcode & COMPCODE_UNORD))
2564 || (code == TRUTH_ANDIF_EXPR && !(lcompcode & COMPCODE_UNORD)))
2567 /* If the comparison was short-circuited, and only the RHS
2568 trapped, we may now generate a spurious trap. */
2570 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2573 /* If we changed the conditions that cause a trap, we lose. */
2574 if ((ltrap || rtrap) != trap)
2578 if (compcode == COMPCODE_TRUE)
2579 return constant_boolean_node (true, truth_type);
2580 else if (compcode == COMPCODE_FALSE)
2581 return constant_boolean_node (false, truth_type);
2583 return fold_build2 (compcode_to_comparison (compcode),
2584 truth_type, ll_arg, lr_arg);
2587 /* Return nonzero if CODE is a tree code that represents a truth value. */
2590 truth_value_p (enum tree_code code)
2592 return (TREE_CODE_CLASS (code) == tcc_comparison
2593 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2594 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2595 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2598 /* Return nonzero if two operands (typically of the same tree node)
2599 are necessarily equal. If either argument has side-effects this
2600 function returns zero. FLAGS modifies behavior as follows:
2602 If OEP_ONLY_CONST is set, only return nonzero for constants.
2603 This function tests whether the operands are indistinguishable;
2604 it does not test whether they are equal using C's == operation.
2605 The distinction is important for IEEE floating point, because
2606 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2607 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2609 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
2610 even though it may hold multiple values during a function.
2611 This is because a GCC tree node guarantees that nothing else is
2612 executed between the evaluation of its "operands" (which may often
2613 be evaluated in arbitrary order). Hence if the operands themselves
2614 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
2615 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
2616 unset means assuming isochronic (or instantaneous) tree equivalence.
2617 Unless comparing arbitrary expression trees, such as from different
2618 statements, this flag can usually be left unset.
2620 If OEP_PURE_SAME is set, then pure functions with identical arguments
2621 are considered the same. It is used when the caller has other ways
2622 to ensure that global memory is unchanged in between. */
2625 operand_equal_p (tree arg0, tree arg1, unsigned int flags)
2627 /* If either is ERROR_MARK, they aren't equal. */
2628 if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK)
2631 /* If both types don't have the same signedness, then we can't consider
2632 them equal. We must check this before the STRIP_NOPS calls
2633 because they may change the signedness of the arguments. */
2634 if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1)))
2637 /* If both types don't have the same precision, then it is not safe
2639 if (TYPE_PRECISION (TREE_TYPE (arg0)) != TYPE_PRECISION (TREE_TYPE (arg1)))
2645 /* In case both args are comparisons but with different comparison
2646 code, try to swap the comparison operands of one arg to produce
2647 a match and compare that variant. */
2648 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2649 && COMPARISON_CLASS_P (arg0)
2650 && COMPARISON_CLASS_P (arg1))
2652 enum tree_code swap_code = swap_tree_comparison (TREE_CODE (arg1));
2654 if (TREE_CODE (arg0) == swap_code)
2655 return operand_equal_p (TREE_OPERAND (arg0, 0),
2656 TREE_OPERAND (arg1, 1), flags)
2657 && operand_equal_p (TREE_OPERAND (arg0, 1),
2658 TREE_OPERAND (arg1, 0), flags);
2661 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2662 /* This is needed for conversions and for COMPONENT_REF.
2663 Might as well play it safe and always test this. */
2664 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2665 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2666 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2669 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2670 We don't care about side effects in that case because the SAVE_EXPR
2671 takes care of that for us. In all other cases, two expressions are
2672 equal if they have no side effects. If we have two identical
2673 expressions with side effects that should be treated the same due
2674 to the only side effects being identical SAVE_EXPR's, that will
2675 be detected in the recursive calls below. */
2676 if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST)
2677 && (TREE_CODE (arg0) == SAVE_EXPR
2678 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2681 /* Next handle constant cases, those for which we can return 1 even
2682 if ONLY_CONST is set. */
2683 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2684 switch (TREE_CODE (arg0))
2687 return (! TREE_CONSTANT_OVERFLOW (arg0)
2688 && ! TREE_CONSTANT_OVERFLOW (arg1)
2689 && tree_int_cst_equal (arg0, arg1));
2692 return (! TREE_CONSTANT_OVERFLOW (arg0)
2693 && ! TREE_CONSTANT_OVERFLOW (arg1)
2694 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2695 TREE_REAL_CST (arg1)));
2701 if (TREE_CONSTANT_OVERFLOW (arg0)
2702 || TREE_CONSTANT_OVERFLOW (arg1))
2705 v1 = TREE_VECTOR_CST_ELTS (arg0);
2706 v2 = TREE_VECTOR_CST_ELTS (arg1);
2709 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
2712 v1 = TREE_CHAIN (v1);
2713 v2 = TREE_CHAIN (v2);
2720 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2722 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2726 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2727 && ! memcmp (TREE_STRING_POINTER (arg0),
2728 TREE_STRING_POINTER (arg1),
2729 TREE_STRING_LENGTH (arg0)));
2732 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2738 if (flags & OEP_ONLY_CONST)
2741 /* Define macros to test an operand from arg0 and arg1 for equality and a
2742 variant that allows null and views null as being different from any
2743 non-null value. In the latter case, if either is null, the both
2744 must be; otherwise, do the normal comparison. */
2745 #define OP_SAME(N) operand_equal_p (TREE_OPERAND (arg0, N), \
2746 TREE_OPERAND (arg1, N), flags)
2748 #define OP_SAME_WITH_NULL(N) \
2749 ((!TREE_OPERAND (arg0, N) || !TREE_OPERAND (arg1, N)) \
2750 ? TREE_OPERAND (arg0, N) == TREE_OPERAND (arg1, N) : OP_SAME (N))
2752 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2755 /* Two conversions are equal only if signedness and modes match. */
2756 switch (TREE_CODE (arg0))
2761 case FIX_TRUNC_EXPR:
2762 case FIX_FLOOR_EXPR:
2763 case FIX_ROUND_EXPR:
2764 if (TYPE_UNSIGNED (TREE_TYPE (arg0))
2765 != TYPE_UNSIGNED (TREE_TYPE (arg1)))
2775 case tcc_comparison:
2777 if (OP_SAME (0) && OP_SAME (1))
2780 /* For commutative ops, allow the other order. */
2781 return (commutative_tree_code (TREE_CODE (arg0))
2782 && operand_equal_p (TREE_OPERAND (arg0, 0),
2783 TREE_OPERAND (arg1, 1), flags)
2784 && operand_equal_p (TREE_OPERAND (arg0, 1),
2785 TREE_OPERAND (arg1, 0), flags));
2788 /* If either of the pointer (or reference) expressions we are
2789 dereferencing contain a side effect, these cannot be equal. */
2790 if (TREE_SIDE_EFFECTS (arg0)
2791 || TREE_SIDE_EFFECTS (arg1))
2794 switch (TREE_CODE (arg0))
2797 case ALIGN_INDIRECT_REF:
2798 case MISALIGNED_INDIRECT_REF:
2804 case ARRAY_RANGE_REF:
2805 /* Operands 2 and 3 may be null. */
2808 && OP_SAME_WITH_NULL (2)
2809 && OP_SAME_WITH_NULL (3));
2812 /* Handle operand 2 the same as for ARRAY_REF. Operand 0
2813 may be NULL when we're called to compare MEM_EXPRs. */
2814 return OP_SAME_WITH_NULL (0)
2816 && OP_SAME_WITH_NULL (2);
2819 return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
2825 case tcc_expression:
2826 switch (TREE_CODE (arg0))
2829 case TRUTH_NOT_EXPR:
2832 case TRUTH_ANDIF_EXPR:
2833 case TRUTH_ORIF_EXPR:
2834 return OP_SAME (0) && OP_SAME (1);
2836 case TRUTH_AND_EXPR:
2838 case TRUTH_XOR_EXPR:
2839 if (OP_SAME (0) && OP_SAME (1))
2842 /* Otherwise take into account this is a commutative operation. */
2843 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2844 TREE_OPERAND (arg1, 1), flags)
2845 && operand_equal_p (TREE_OPERAND (arg0, 1),
2846 TREE_OPERAND (arg1, 0), flags));
2849 /* If the CALL_EXPRs call different functions, then they
2850 clearly can not be equal. */
2855 unsigned int cef = call_expr_flags (arg0);
2856 if (flags & OEP_PURE_SAME)
2857 cef &= ECF_CONST | ECF_PURE;
2864 /* Now see if all the arguments are the same. operand_equal_p
2865 does not handle TREE_LIST, so we walk the operands here
2866 feeding them to operand_equal_p. */
2867 arg0 = TREE_OPERAND (arg0, 1);
2868 arg1 = TREE_OPERAND (arg1, 1);
2869 while (arg0 && arg1)
2871 if (! operand_equal_p (TREE_VALUE (arg0), TREE_VALUE (arg1),
2875 arg0 = TREE_CHAIN (arg0);
2876 arg1 = TREE_CHAIN (arg1);
2879 /* If we get here and both argument lists are exhausted
2880 then the CALL_EXPRs are equal. */
2881 return ! (arg0 || arg1);
2887 case tcc_declaration:
2888 /* Consider __builtin_sqrt equal to sqrt. */
2889 return (TREE_CODE (arg0) == FUNCTION_DECL
2890 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
2891 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
2892 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
2899 #undef OP_SAME_WITH_NULL
2902 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2903 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2905 When in doubt, return 0. */
2908 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
2910 int unsignedp1, unsignedpo;
2911 tree primarg0, primarg1, primother;
2912 unsigned int correct_width;
2914 if (operand_equal_p (arg0, arg1, 0))
2917 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2918 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2921 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2922 and see if the inner values are the same. This removes any
2923 signedness comparison, which doesn't matter here. */
2924 primarg0 = arg0, primarg1 = arg1;
2925 STRIP_NOPS (primarg0);
2926 STRIP_NOPS (primarg1);
2927 if (operand_equal_p (primarg0, primarg1, 0))
2930 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2931 actual comparison operand, ARG0.
2933 First throw away any conversions to wider types
2934 already present in the operands. */
2936 primarg1 = get_narrower (arg1, &unsignedp1);
2937 primother = get_narrower (other, &unsignedpo);
2939 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2940 if (unsignedp1 == unsignedpo
2941 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2942 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2944 tree type = TREE_TYPE (arg0);
2946 /* Make sure shorter operand is extended the right way
2947 to match the longer operand. */
2948 primarg1 = fold_convert (lang_hooks.types.signed_or_unsigned_type
2949 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
2951 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
2958 /* See if ARG is an expression that is either a comparison or is performing
2959 arithmetic on comparisons. The comparisons must only be comparing
2960 two different values, which will be stored in *CVAL1 and *CVAL2; if
2961 they are nonzero it means that some operands have already been found.
2962 No variables may be used anywhere else in the expression except in the
2963 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2964 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2966 If this is true, return 1. Otherwise, return zero. */
2969 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
2971 enum tree_code code = TREE_CODE (arg);
2972 enum tree_code_class class = TREE_CODE_CLASS (code);
2974 /* We can handle some of the tcc_expression cases here. */
2975 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
2977 else if (class == tcc_expression
2978 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2979 || code == COMPOUND_EXPR))
2982 else if (class == tcc_expression && code == SAVE_EXPR
2983 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2985 /* If we've already found a CVAL1 or CVAL2, this expression is
2986 two complex to handle. */
2987 if (*cval1 || *cval2)
2997 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
3000 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
3001 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3002 cval1, cval2, save_p));
3007 case tcc_expression:
3008 if (code == COND_EXPR)
3009 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
3010 cval1, cval2, save_p)
3011 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3012 cval1, cval2, save_p)
3013 && twoval_comparison_p (TREE_OPERAND (arg, 2),
3014 cval1, cval2, save_p));
3017 case tcc_comparison:
3018 /* First see if we can handle the first operand, then the second. For
3019 the second operand, we know *CVAL1 can't be zero. It must be that
3020 one side of the comparison is each of the values; test for the
3021 case where this isn't true by failing if the two operands
3024 if (operand_equal_p (TREE_OPERAND (arg, 0),
3025 TREE_OPERAND (arg, 1), 0))
3029 *cval1 = TREE_OPERAND (arg, 0);
3030 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
3032 else if (*cval2 == 0)
3033 *cval2 = TREE_OPERAND (arg, 0);
3034 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
3039 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
3041 else if (*cval2 == 0)
3042 *cval2 = TREE_OPERAND (arg, 1);
3043 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
3055 /* ARG is a tree that is known to contain just arithmetic operations and
3056 comparisons. Evaluate the operations in the tree substituting NEW0 for
3057 any occurrence of OLD0 as an operand of a comparison and likewise for
3061 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
3063 tree type = TREE_TYPE (arg);
3064 enum tree_code code = TREE_CODE (arg);
3065 enum tree_code_class class = TREE_CODE_CLASS (code);
3067 /* We can handle some of the tcc_expression cases here. */
3068 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
3070 else if (class == tcc_expression
3071 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
3077 return fold_build1 (code, type,
3078 eval_subst (TREE_OPERAND (arg, 0),
3079 old0, new0, old1, new1));
3082 return fold_build2 (code, type,
3083 eval_subst (TREE_OPERAND (arg, 0),
3084 old0, new0, old1, new1),
3085 eval_subst (TREE_OPERAND (arg, 1),
3086 old0, new0, old1, new1));
3088 case tcc_expression:
3092 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
3095 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
3098 return fold_build3 (code, type,
3099 eval_subst (TREE_OPERAND (arg, 0),
3100 old0, new0, old1, new1),
3101 eval_subst (TREE_OPERAND (arg, 1),
3102 old0, new0, old1, new1),
3103 eval_subst (TREE_OPERAND (arg, 2),
3104 old0, new0, old1, new1));
3108 /* Fall through - ??? */
3110 case tcc_comparison:
3112 tree arg0 = TREE_OPERAND (arg, 0);
3113 tree arg1 = TREE_OPERAND (arg, 1);
3115 /* We need to check both for exact equality and tree equality. The
3116 former will be true if the operand has a side-effect. In that
3117 case, we know the operand occurred exactly once. */
3119 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
3121 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
3124 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
3126 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
3129 return fold_build2 (code, type, arg0, arg1);
3137 /* Return a tree for the case when the result of an expression is RESULT
3138 converted to TYPE and OMITTED was previously an operand of the expression
3139 but is now not needed (e.g., we folded OMITTED * 0).
3141 If OMITTED has side effects, we must evaluate it. Otherwise, just do
3142 the conversion of RESULT to TYPE. */
3145 omit_one_operand (tree type, tree result, tree omitted)
3147 tree t = fold_convert (type, result);
3149 if (TREE_SIDE_EFFECTS (omitted))
3150 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
3152 return non_lvalue (t);
3155 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
3158 pedantic_omit_one_operand (tree type, tree result, tree omitted)
3160 tree t = fold_convert (type, result);
3162 if (TREE_SIDE_EFFECTS (omitted))
3163 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
3165 return pedantic_non_lvalue (t);
3168 /* Return a tree for the case when the result of an expression is RESULT
3169 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
3170 of the expression but are now not needed.
3172 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
3173 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
3174 evaluated before OMITTED2. Otherwise, if neither has side effects,
3175 just do the conversion of RESULT to TYPE. */
3178 omit_two_operands (tree type, tree result, tree omitted1, tree omitted2)
3180 tree t = fold_convert (type, result);
3182 if (TREE_SIDE_EFFECTS (omitted2))
3183 t = build2 (COMPOUND_EXPR, type, omitted2, t);
3184 if (TREE_SIDE_EFFECTS (omitted1))
3185 t = build2 (COMPOUND_EXPR, type, omitted1, t);
3187 return TREE_CODE (t) != COMPOUND_EXPR ? non_lvalue (t) : t;
3191 /* Return a simplified tree node for the truth-negation of ARG. This
3192 never alters ARG itself. We assume that ARG is an operation that
3193 returns a truth value (0 or 1).
3195 FIXME: one would think we would fold the result, but it causes
3196 problems with the dominator optimizer. */
3199 fold_truth_not_expr (tree arg)
3201 tree type = TREE_TYPE (arg);
3202 enum tree_code code = TREE_CODE (arg);
3204 /* If this is a comparison, we can simply invert it, except for
3205 floating-point non-equality comparisons, in which case we just
3206 enclose a TRUTH_NOT_EXPR around what we have. */
3208 if (TREE_CODE_CLASS (code) == tcc_comparison)
3210 tree op_type = TREE_TYPE (TREE_OPERAND (arg, 0));
3211 if (FLOAT_TYPE_P (op_type)
3212 && flag_trapping_math
3213 && code != ORDERED_EXPR && code != UNORDERED_EXPR
3214 && code != NE_EXPR && code != EQ_EXPR)
3218 code = invert_tree_comparison (code,
3219 HONOR_NANS (TYPE_MODE (op_type)));
3220 if (code == ERROR_MARK)
3223 return build2 (code, type,
3224 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
3231 return constant_boolean_node (integer_zerop (arg), type);
3233 case TRUTH_AND_EXPR:
3234 return build2 (TRUTH_OR_EXPR, type,
3235 invert_truthvalue (TREE_OPERAND (arg, 0)),
3236 invert_truthvalue (TREE_OPERAND (arg, 1)));
3239 return build2 (TRUTH_AND_EXPR, type,
3240 invert_truthvalue (TREE_OPERAND (arg, 0)),
3241 invert_truthvalue (TREE_OPERAND (arg, 1)));
3243 case TRUTH_XOR_EXPR:
3244 /* Here we can invert either operand. We invert the first operand
3245 unless the second operand is a TRUTH_NOT_EXPR in which case our
3246 result is the XOR of the first operand with the inside of the
3247 negation of the second operand. */
3249 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
3250 return build2 (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
3251 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
3253 return build2 (TRUTH_XOR_EXPR, type,
3254 invert_truthvalue (TREE_OPERAND (arg, 0)),
3255 TREE_OPERAND (arg, 1));
3257 case TRUTH_ANDIF_EXPR:
3258 return build2 (TRUTH_ORIF_EXPR, type,
3259 invert_truthvalue (TREE_OPERAND (arg, 0)),
3260 invert_truthvalue (TREE_OPERAND (arg, 1)));
3262 case TRUTH_ORIF_EXPR:
3263 return build2 (TRUTH_ANDIF_EXPR, type,
3264 invert_truthvalue (TREE_OPERAND (arg, 0)),
3265 invert_truthvalue (TREE_OPERAND (arg, 1)));
3267 case TRUTH_NOT_EXPR:
3268 return TREE_OPERAND (arg, 0);
3272 tree arg1 = TREE_OPERAND (arg, 1);
3273 tree arg2 = TREE_OPERAND (arg, 2);
3274 /* A COND_EXPR may have a throw as one operand, which
3275 then has void type. Just leave void operands
3277 return build3 (COND_EXPR, type, TREE_OPERAND (arg, 0),
3278 VOID_TYPE_P (TREE_TYPE (arg1))
3279 ? arg1 : invert_truthvalue (arg1),
3280 VOID_TYPE_P (TREE_TYPE (arg2))
3281 ? arg2 : invert_truthvalue (arg2));
3285 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
3286 invert_truthvalue (TREE_OPERAND (arg, 1)));
3288 case NON_LVALUE_EXPR:
3289 return invert_truthvalue (TREE_OPERAND (arg, 0));
3292 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
3293 return build1 (TRUTH_NOT_EXPR, type, arg);
3297 return build1 (TREE_CODE (arg), type,
3298 invert_truthvalue (TREE_OPERAND (arg, 0)));
3301 if (!integer_onep (TREE_OPERAND (arg, 1)))
3303 return build2 (EQ_EXPR, type, arg,
3304 build_int_cst (type, 0));
3307 return build1 (TRUTH_NOT_EXPR, type, arg);
3309 case CLEANUP_POINT_EXPR:
3310 return build1 (CLEANUP_POINT_EXPR, type,
3311 invert_truthvalue (TREE_OPERAND (arg, 0)));
3320 /* Return a simplified tree node for the truth-negation of ARG. This
3321 never alters ARG itself. We assume that ARG is an operation that
3322 returns a truth value (0 or 1).
3324 FIXME: one would think we would fold the result, but it causes
3325 problems with the dominator optimizer. */
3328 invert_truthvalue (tree arg)
3332 if (TREE_CODE (arg) == ERROR_MARK)
3335 tem = fold_truth_not_expr (arg);
3337 tem = build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg), arg);
3342 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
3343 operands are another bit-wise operation with a common input. If so,
3344 distribute the bit operations to save an operation and possibly two if
3345 constants are involved. For example, convert
3346 (A | B) & (A | C) into A | (B & C)
3347 Further simplification will occur if B and C are constants.
3349 If this optimization cannot be done, 0 will be returned. */
3352 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
3357 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3358 || TREE_CODE (arg0) == code
3359 || (TREE_CODE (arg0) != BIT_AND_EXPR
3360 && TREE_CODE (arg0) != BIT_IOR_EXPR))
3363 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
3365 common = TREE_OPERAND (arg0, 0);
3366 left = TREE_OPERAND (arg0, 1);
3367 right = TREE_OPERAND (arg1, 1);
3369 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
3371 common = TREE_OPERAND (arg0, 0);
3372 left = TREE_OPERAND (arg0, 1);
3373 right = TREE_OPERAND (arg1, 0);
3375 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
3377 common = TREE_OPERAND (arg0, 1);
3378 left = TREE_OPERAND (arg0, 0);
3379 right = TREE_OPERAND (arg1, 1);
3381 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
3383 common = TREE_OPERAND (arg0, 1);
3384 left = TREE_OPERAND (arg0, 0);
3385 right = TREE_OPERAND (arg1, 0);
3390 return fold_build2 (TREE_CODE (arg0), type, common,
3391 fold_build2 (code, type, left, right));
3394 /* Knowing that ARG0 and ARG1 are both RDIV_EXPRs, simplify a binary operation
3395 with code CODE. This optimization is unsafe. */
3397 distribute_real_division (enum tree_code code, tree type, tree arg0, tree arg1)
3399 bool mul0 = TREE_CODE (arg0) == MULT_EXPR;
3400 bool mul1 = TREE_CODE (arg1) == MULT_EXPR;
3402 /* (A / C) +- (B / C) -> (A +- B) / C. */
3404 && operand_equal_p (TREE_OPERAND (arg0, 1),
3405 TREE_OPERAND (arg1, 1), 0))
3406 return fold_build2 (mul0 ? MULT_EXPR : RDIV_EXPR, type,
3407 fold_build2 (code, type,
3408 TREE_OPERAND (arg0, 0),
3409 TREE_OPERAND (arg1, 0)),
3410 TREE_OPERAND (arg0, 1));
3412 /* (A / C1) +- (A / C2) -> A * (1 / C1 +- 1 / C2). */
3413 if (operand_equal_p (TREE_OPERAND (arg0, 0),
3414 TREE_OPERAND (arg1, 0), 0)
3415 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
3416 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
3418 REAL_VALUE_TYPE r0, r1;
3419 r0 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
3420 r1 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
3422 real_arithmetic (&r0, RDIV_EXPR, &dconst1, &r0);
3424 real_arithmetic (&r1, RDIV_EXPR, &dconst1, &r1);
3425 real_arithmetic (&r0, code, &r0, &r1);
3426 return fold_build2 (MULT_EXPR, type,
3427 TREE_OPERAND (arg0, 0),
3428 build_real (type, r0));
3434 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
3435 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
3438 make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos,
3445 tree size = TYPE_SIZE (TREE_TYPE (inner));
3446 if ((INTEGRAL_TYPE_P (TREE_TYPE (inner))
3447 || POINTER_TYPE_P (TREE_TYPE (inner)))
3448 && host_integerp (size, 0)
3449 && tree_low_cst (size, 0) == bitsize)
3450 return fold_convert (type, inner);
3453 result = build3 (BIT_FIELD_REF, type, inner,
3454 size_int (bitsize), bitsize_int (bitpos));
3456 BIT_FIELD_REF_UNSIGNED (result) = unsignedp;
3461 /* Optimize a bit-field compare.
3463 There are two cases: First is a compare against a constant and the
3464 second is a comparison of two items where the fields are at the same
3465 bit position relative to the start of a chunk (byte, halfword, word)
3466 large enough to contain it. In these cases we can avoid the shift
3467 implicit in bitfield extractions.
3469 For constants, we emit a compare of the shifted constant with the
3470 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
3471 compared. For two fields at the same position, we do the ANDs with the
3472 similar mask and compare the result of the ANDs.
3474 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
3475 COMPARE_TYPE is the type of the comparison, and LHS and RHS
3476 are the left and right operands of the comparison, respectively.
3478 If the optimization described above can be done, we return the resulting
3479 tree. Otherwise we return zero. */
3482 optimize_bit_field_compare (enum tree_code code, tree compare_type,
3485 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
3486 tree type = TREE_TYPE (lhs);
3487 tree signed_type, unsigned_type;
3488 int const_p = TREE_CODE (rhs) == INTEGER_CST;
3489 enum machine_mode lmode, rmode, nmode;
3490 int lunsignedp, runsignedp;
3491 int lvolatilep = 0, rvolatilep = 0;
3492 tree linner, rinner = NULL_TREE;
3496 /* Get all the information about the extractions being done. If the bit size
3497 if the same as the size of the underlying object, we aren't doing an
3498 extraction at all and so can do nothing. We also don't want to
3499 do anything if the inner expression is a PLACEHOLDER_EXPR since we
3500 then will no longer be able to replace it. */
3501 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
3502 &lunsignedp, &lvolatilep, false);
3503 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
3504 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
3509 /* If this is not a constant, we can only do something if bit positions,
3510 sizes, and signedness are the same. */
3511 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
3512 &runsignedp, &rvolatilep, false);
3514 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
3515 || lunsignedp != runsignedp || offset != 0
3516 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
3520 /* See if we can find a mode to refer to this field. We should be able to,
3521 but fail if we can't. */
3522 nmode = get_best_mode (lbitsize, lbitpos,
3523 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
3524 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
3525 TYPE_ALIGN (TREE_TYPE (rinner))),
3526 word_mode, lvolatilep || rvolatilep);
3527 if (nmode == VOIDmode)
3530 /* Set signed and unsigned types of the precision of this mode for the
3532 signed_type = lang_hooks.types.type_for_mode (nmode, 0);
3533 unsigned_type = lang_hooks.types.type_for_mode (nmode, 1);
3535 /* Compute the bit position and size for the new reference and our offset
3536 within it. If the new reference is the same size as the original, we
3537 won't optimize anything, so return zero. */
3538 nbitsize = GET_MODE_BITSIZE (nmode);
3539 nbitpos = lbitpos & ~ (nbitsize - 1);
3541 if (nbitsize == lbitsize)
3544 if (BYTES_BIG_ENDIAN)
3545 lbitpos = nbitsize - lbitsize - lbitpos;
3547 /* Make the mask to be used against the extracted field. */
3548 mask = build_int_cst (unsigned_type, -1);
3549 mask = force_fit_type (mask, 0, false, false);
3550 mask = fold_convert (unsigned_type, mask);
3551 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
3552 mask = const_binop (RSHIFT_EXPR, mask,
3553 size_int (nbitsize - lbitsize - lbitpos), 0);
3556 /* If not comparing with constant, just rework the comparison
3558 return build2 (code, compare_type,
3559 build2 (BIT_AND_EXPR, unsigned_type,
3560 make_bit_field_ref (linner, unsigned_type,
3561 nbitsize, nbitpos, 1),
3563 build2 (BIT_AND_EXPR, unsigned_type,
3564 make_bit_field_ref (rinner, unsigned_type,
3565 nbitsize, nbitpos, 1),
3568 /* Otherwise, we are handling the constant case. See if the constant is too
3569 big for the field. Warn and return a tree of for 0 (false) if so. We do
3570 this not only for its own sake, but to avoid having to test for this
3571 error case below. If we didn't, we might generate wrong code.
3573 For unsigned fields, the constant shifted right by the field length should
3574 be all zero. For signed fields, the high-order bits should agree with
3579 if (! integer_zerop (const_binop (RSHIFT_EXPR,
3580 fold_convert (unsigned_type, rhs),
3581 size_int (lbitsize), 0)))
3583 warning (0, "comparison is always %d due to width of bit-field",
3585 return constant_boolean_node (code == NE_EXPR, compare_type);
3590 tree tem = const_binop (RSHIFT_EXPR, fold_convert (signed_type, rhs),
3591 size_int (lbitsize - 1), 0);
3592 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
3594 warning (0, "comparison is always %d due to width of bit-field",
3596 return constant_boolean_node (code == NE_EXPR, compare_type);
3600 /* Single-bit compares should always be against zero. */
3601 if (lbitsize == 1 && ! integer_zerop (rhs))
3603 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
3604 rhs = build_int_cst (type, 0);
3607 /* Make a new bitfield reference, shift the constant over the
3608 appropriate number of bits and mask it with the computed mask
3609 (in case this was a signed field). If we changed it, make a new one. */
3610 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
3613 TREE_SIDE_EFFECTS (lhs) = 1;
3614 TREE_THIS_VOLATILE (lhs) = 1;
3617 rhs = const_binop (BIT_AND_EXPR,
3618 const_binop (LSHIFT_EXPR,
3619 fold_convert (unsigned_type, rhs),
3620 size_int (lbitpos), 0),
3623 return build2 (code, compare_type,
3624 build2 (BIT_AND_EXPR, unsigned_type, lhs, mask),
3628 /* Subroutine for fold_truthop: decode a field reference.
3630 If EXP is a comparison reference, we return the innermost reference.
3632 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3633 set to the starting bit number.
3635 If the innermost field can be completely contained in a mode-sized
3636 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3638 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3639 otherwise it is not changed.
3641 *PUNSIGNEDP is set to the signedness of the field.
3643 *PMASK is set to the mask used. This is either contained in a
3644 BIT_AND_EXPR or derived from the width of the field.
3646 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3648 Return 0 if this is not a component reference or is one that we can't
3649 do anything with. */
3652 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
3653 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
3654 int *punsignedp, int *pvolatilep,
3655 tree *pmask, tree *pand_mask)
3657 tree outer_type = 0;
3659 tree mask, inner, offset;
3661 unsigned int precision;
3663 /* All the optimizations using this function assume integer fields.
3664 There are problems with FP fields since the type_for_size call
3665 below can fail for, e.g., XFmode. */
3666 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3669 /* We are interested in the bare arrangement of bits, so strip everything
3670 that doesn't affect the machine mode. However, record the type of the
3671 outermost expression if it may matter below. */
3672 if (TREE_CODE (exp) == NOP_EXPR
3673 || TREE_CODE (exp) == CONVERT_EXPR
3674 || TREE_CODE (exp) == NON_LVALUE_EXPR)
3675 outer_type = TREE_TYPE (exp);
3678 if (TREE_CODE (exp) == BIT_AND_EXPR)
3680 and_mask = TREE_OPERAND (exp, 1);
3681 exp = TREE_OPERAND (exp, 0);
3682 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3683 if (TREE_CODE (and_mask) != INTEGER_CST)
3687 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3688 punsignedp, pvolatilep, false);
3689 if ((inner == exp && and_mask == 0)
3690 || *pbitsize < 0 || offset != 0
3691 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3694 /* If the number of bits in the reference is the same as the bitsize of
3695 the outer type, then the outer type gives the signedness. Otherwise
3696 (in case of a small bitfield) the signedness is unchanged. */
3697 if (outer_type && *pbitsize == TYPE_PRECISION (outer_type))
3698 *punsignedp = TYPE_UNSIGNED (outer_type);
3700 /* Compute the mask to access the bitfield. */
3701 unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
3702 precision = TYPE_PRECISION (unsigned_type);
3704 mask = build_int_cst (unsigned_type, -1);
3705 mask = force_fit_type (mask, 0, false, false);
3707 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3708 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3710 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3712 mask = fold_build2 (BIT_AND_EXPR, unsigned_type,
3713 fold_convert (unsigned_type, and_mask), mask);
3716 *pand_mask = and_mask;
3720 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
3724 all_ones_mask_p (tree mask, int size)
3726 tree type = TREE_TYPE (mask);
3727 unsigned int precision = TYPE_PRECISION (type);
3730 tmask = build_int_cst (lang_hooks.types.signed_type (type), -1);
3731 tmask = force_fit_type (tmask, 0, false, false);
3734 tree_int_cst_equal (mask,
3735 const_binop (RSHIFT_EXPR,
3736 const_binop (LSHIFT_EXPR, tmask,
3737 size_int (precision - size),
3739 size_int (precision - size), 0));
3742 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
3743 represents the sign bit of EXP's type. If EXP represents a sign
3744 or zero extension, also test VAL against the unextended type.
3745 The return value is the (sub)expression whose sign bit is VAL,
3746 or NULL_TREE otherwise. */
3749 sign_bit_p (tree exp, tree val)
3751 unsigned HOST_WIDE_INT mask_lo, lo;
3752 HOST_WIDE_INT mask_hi, hi;
3756 /* Tree EXP must have an integral type. */
3757 t = TREE_TYPE (exp);
3758 if (! INTEGRAL_TYPE_P (t))
3761 /* Tree VAL must be an integer constant. */
3762 if (TREE_CODE (val) != INTEGER_CST
3763 || TREE_CONSTANT_OVERFLOW (val))
3766 width = TYPE_PRECISION (t);
3767 if (width > HOST_BITS_PER_WIDE_INT)
3769 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
3772 mask_hi = ((unsigned HOST_WIDE_INT) -1
3773 >> (2 * HOST_BITS_PER_WIDE_INT - width));
3779 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
3782 mask_lo = ((unsigned HOST_WIDE_INT) -1
3783 >> (HOST_BITS_PER_WIDE_INT - width));
3786 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
3787 treat VAL as if it were unsigned. */
3788 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
3789 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
3792 /* Handle extension from a narrower type. */
3793 if (TREE_CODE (exp) == NOP_EXPR
3794 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
3795 return sign_bit_p (TREE_OPERAND (exp, 0), val);
3800 /* Subroutine for fold_truthop: determine if an operand is simple enough
3801 to be evaluated unconditionally. */
3804 simple_operand_p (tree exp)
3806 /* Strip any conversions that don't change the machine mode. */
3809 return (CONSTANT_CLASS_P (exp)
3810 || TREE_CODE (exp) == SSA_NAME
3812 && ! TREE_ADDRESSABLE (exp)
3813 && ! TREE_THIS_VOLATILE (exp)
3814 && ! DECL_NONLOCAL (exp)
3815 /* Don't regard global variables as simple. They may be
3816 allocated in ways unknown to the compiler (shared memory,
3817 #pragma weak, etc). */
3818 && ! TREE_PUBLIC (exp)
3819 && ! DECL_EXTERNAL (exp)
3820 /* Loading a static variable is unduly expensive, but global
3821 registers aren't expensive. */
3822 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3825 /* The following functions are subroutines to fold_range_test and allow it to
3826 try to change a logical combination of comparisons into a range test.
3829 X == 2 || X == 3 || X == 4 || X == 5
3833 (unsigned) (X - 2) <= 3
3835 We describe each set of comparisons as being either inside or outside
3836 a range, using a variable named like IN_P, and then describe the
3837 range with a lower and upper bound. If one of the bounds is omitted,
3838 it represents either the highest or lowest value of the type.
3840 In the comments below, we represent a range by two numbers in brackets
3841 preceded by a "+" to designate being inside that range, or a "-" to
3842 designate being outside that range, so the condition can be inverted by
3843 flipping the prefix. An omitted bound is represented by a "-". For
3844 example, "- [-, 10]" means being outside the range starting at the lowest
3845 possible value and ending at 10, in other words, being greater than 10.
3846 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3849 We set up things so that the missing bounds are handled in a consistent
3850 manner so neither a missing bound nor "true" and "false" need to be
3851 handled using a special case. */
3853 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3854 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3855 and UPPER1_P are nonzero if the respective argument is an upper bound
3856 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3857 must be specified for a comparison. ARG1 will be converted to ARG0's
3858 type if both are specified. */
3861 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
3862 tree arg1, int upper1_p)
3868 /* If neither arg represents infinity, do the normal operation.
3869 Else, if not a comparison, return infinity. Else handle the special
3870 comparison rules. Note that most of the cases below won't occur, but
3871 are handled for consistency. */
3873 if (arg0 != 0 && arg1 != 0)
3875 tem = fold_build2 (code, type != 0 ? type : TREE_TYPE (arg0),
3876 arg0, fold_convert (TREE_TYPE (arg0), arg1));
3878 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3881 if (TREE_CODE_CLASS (code) != tcc_comparison)
3884 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3885 for neither. In real maths, we cannot assume open ended ranges are
3886 the same. But, this is computer arithmetic, where numbers are finite.
3887 We can therefore make the transformation of any unbounded range with
3888 the value Z, Z being greater than any representable number. This permits
3889 us to treat unbounded ranges as equal. */
3890 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3891 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3895 result = sgn0 == sgn1;
3898 result = sgn0 != sgn1;
3901 result = sgn0 < sgn1;
3904 result = sgn0 <= sgn1;
3907 result = sgn0 > sgn1;
3910 result = sgn0 >= sgn1;
3916 return constant_boolean_node (result, type);
3919 /* Given EXP, a logical expression, set the range it is testing into
3920 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3921 actually being tested. *PLOW and *PHIGH will be made of the same
3922 type as the returned expression. If EXP is not a comparison, we
3923 will most likely not be returning a useful value and range. Set
3924 *STRICT_OVERFLOW_P to true if the return value is only valid
3925 because signed overflow is undefined; otherwise, do not change
3926 *STRICT_OVERFLOW_P. */
3929 make_range (tree exp, int *pin_p, tree *plow, tree *phigh,
3930 bool *strict_overflow_p)
3932 enum tree_code code;
3933 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
3934 tree exp_type = NULL_TREE, arg0_type = NULL_TREE;
3936 tree low, high, n_low, n_high;
3938 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3939 and see if we can refine the range. Some of the cases below may not
3940 happen, but it doesn't seem worth worrying about this. We "continue"
3941 the outer loop when we've changed something; otherwise we "break"
3942 the switch, which will "break" the while. */
3945 low = high = build_int_cst (TREE_TYPE (exp), 0);
3949 code = TREE_CODE (exp);
3950 exp_type = TREE_TYPE (exp);
3952 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3954 if (TREE_CODE_LENGTH (code) > 0)
3955 arg0 = TREE_OPERAND (exp, 0);
3956 if (TREE_CODE_CLASS (code) == tcc_comparison
3957 || TREE_CODE_CLASS (code) == tcc_unary
3958 || TREE_CODE_CLASS (code) == tcc_binary)
3959 arg0_type = TREE_TYPE (arg0);
3960 if (TREE_CODE_CLASS (code) == tcc_binary
3961 || TREE_CODE_CLASS (code) == tcc_comparison
3962 || (TREE_CODE_CLASS (code) == tcc_expression
3963 && TREE_CODE_LENGTH (code) > 1))
3964 arg1 = TREE_OPERAND (exp, 1);
3969 case TRUTH_NOT_EXPR:
3970 in_p = ! in_p, exp = arg0;
3973 case EQ_EXPR: case NE_EXPR:
3974 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3975 /* We can only do something if the range is testing for zero
3976 and if the second operand is an integer constant. Note that
3977 saying something is "in" the range we make is done by
3978 complementing IN_P since it will set in the initial case of
3979 being not equal to zero; "out" is leaving it alone. */
3980 if (low == 0 || high == 0
3981 || ! integer_zerop (low) || ! integer_zerop (high)
3982 || TREE_CODE (arg1) != INTEGER_CST)
3987 case NE_EXPR: /* - [c, c] */
3990 case EQ_EXPR: /* + [c, c] */
3991 in_p = ! in_p, low = high = arg1;
3993 case GT_EXPR: /* - [-, c] */
3994 low = 0, high = arg1;
3996 case GE_EXPR: /* + [c, -] */
3997 in_p = ! in_p, low = arg1, high = 0;
3999 case LT_EXPR: /* - [c, -] */
4000 low = arg1, high = 0;
4002 case LE_EXPR: /* + [-, c] */
4003 in_p = ! in_p, low = 0, high = arg1;
4009 /* If this is an unsigned comparison, we also know that EXP is
4010 greater than or equal to zero. We base the range tests we make
4011 on that fact, so we record it here so we can parse existing
4012 range tests. We test arg0_type since often the return type
4013 of, e.g. EQ_EXPR, is boolean. */
4014 if (TYPE_UNSIGNED (arg0_type) && (low == 0 || high == 0))
4016 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4018 build_int_cst (arg0_type, 0),
4022 in_p = n_in_p, low = n_low, high = n_high;
4024 /* If the high bound is missing, but we have a nonzero low
4025 bound, reverse the range so it goes from zero to the low bound
4027 if (high == 0 && low && ! integer_zerop (low))
4030 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
4031 integer_one_node, 0);
4032 low = build_int_cst (arg0_type, 0);
4040 /* (-x) IN [a,b] -> x in [-b, -a] */
4041 n_low = range_binop (MINUS_EXPR, exp_type,
4042 build_int_cst (exp_type, 0),
4044 n_high = range_binop (MINUS_EXPR, exp_type,
4045 build_int_cst (exp_type, 0),
4047 low = n_low, high = n_high;
4053 exp = build2 (MINUS_EXPR, exp_type, negate_expr (arg0),
4054 build_int_cst (exp_type, 1));
4057 case PLUS_EXPR: case MINUS_EXPR:
4058 if (TREE_CODE (arg1) != INTEGER_CST)
4061 /* If flag_wrapv and ARG0_TYPE is signed, then we cannot
4062 move a constant to the other side. */
4063 if (!TYPE_UNSIGNED (arg0_type)
4064 && !TYPE_OVERFLOW_UNDEFINED (arg0_type))
4067 /* If EXP is signed, any overflow in the computation is undefined,
4068 so we don't worry about it so long as our computations on
4069 the bounds don't overflow. For unsigned, overflow is defined
4070 and this is exactly the right thing. */
4071 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4072 arg0_type, low, 0, arg1, 0);
4073 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4074 arg0_type, high, 1, arg1, 0);
4075 if ((n_low != 0 && TREE_OVERFLOW (n_low))
4076 || (n_high != 0 && TREE_OVERFLOW (n_high)))
4079 if (TYPE_OVERFLOW_UNDEFINED (arg0_type))
4080 *strict_overflow_p = true;
4082 /* Check for an unsigned range which has wrapped around the maximum
4083 value thus making n_high < n_low, and normalize it. */
4084 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
4086 low = range_binop (PLUS_EXPR, arg0_type, n_high, 0,
4087 integer_one_node, 0);
4088 high = range_binop (MINUS_EXPR, arg0_type, n_low, 0,
4089 integer_one_node, 0);
4091 /* If the range is of the form +/- [ x+1, x ], we won't
4092 be able to normalize it. But then, it represents the
4093 whole range or the empty set, so make it
4095 if (tree_int_cst_equal (n_low, low)
4096 && tree_int_cst_equal (n_high, high))
4102 low = n_low, high = n_high;
4107 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
4108 if (TYPE_PRECISION (arg0_type) > TYPE_PRECISION (exp_type))
4111 if (! INTEGRAL_TYPE_P (arg0_type)
4112 || (low != 0 && ! int_fits_type_p (low, arg0_type))
4113 || (high != 0 && ! int_fits_type_p (high, arg0_type)))
4116 n_low = low, n_high = high;
4119 n_low = fold_convert (arg0_type, n_low);
4122 n_high = fold_convert (arg0_type, n_high);
4125 /* If we're converting arg0 from an unsigned type, to exp,
4126 a signed type, we will be doing the comparison as unsigned.
4127 The tests above have already verified that LOW and HIGH
4130 So we have to ensure that we will handle large unsigned
4131 values the same way that the current signed bounds treat
4134 if (!TYPE_UNSIGNED (exp_type) && TYPE_UNSIGNED (arg0_type))
4137 tree equiv_type = lang_hooks.types.type_for_mode
4138 (TYPE_MODE (arg0_type), 1);
4140 /* A range without an upper bound is, naturally, unbounded.
4141 Since convert would have cropped a very large value, use
4142 the max value for the destination type. */
4144 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
4145 : TYPE_MAX_VALUE (arg0_type);
4147 if (TYPE_PRECISION (exp_type) == TYPE_PRECISION (arg0_type))
4148 high_positive = fold_build2 (RSHIFT_EXPR, arg0_type,
4149 fold_convert (arg0_type,
4151 fold_convert (arg0_type,
4154 /* If the low bound is specified, "and" the range with the
4155 range for which the original unsigned value will be
4159 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4160 1, n_low, n_high, 1,
4161 fold_convert (arg0_type,
4166 in_p = (n_in_p == in_p);
4170 /* Otherwise, "or" the range with the range of the input
4171 that will be interpreted as negative. */
4172 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4173 0, n_low, n_high, 1,
4174 fold_convert (arg0_type,
4179 in_p = (in_p != n_in_p);
4184 low = n_low, high = n_high;
4194 /* If EXP is a constant, we can evaluate whether this is true or false. */
4195 if (TREE_CODE (exp) == INTEGER_CST)
4197 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
4199 && integer_onep (range_binop (LE_EXPR, integer_type_node,
4205 *pin_p = in_p, *plow = low, *phigh = high;
4209 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
4210 type, TYPE, return an expression to test if EXP is in (or out of, depending
4211 on IN_P) the range. Return 0 if the test couldn't be created. */
4214 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
4216 tree etype = TREE_TYPE (exp);
4219 #ifdef HAVE_canonicalize_funcptr_for_compare
4220 /* Disable this optimization for function pointer expressions
4221 on targets that require function pointer canonicalization. */
4222 if (HAVE_canonicalize_funcptr_for_compare
4223 && TREE_CODE (etype) == POINTER_TYPE
4224 && TREE_CODE (TREE_TYPE (etype)) == FUNCTION_TYPE)
4230 value = build_range_check (type, exp, 1, low, high);
4232 return invert_truthvalue (value);
4237 if (low == 0 && high == 0)
4238 return build_int_cst (type, 1);
4241 return fold_build2 (LE_EXPR, type, exp,
4242 fold_convert (etype, high));
4245 return fold_build2 (GE_EXPR, type, exp,
4246 fold_convert (etype, low));
4248 if (operand_equal_p (low, high, 0))
4249 return fold_build2 (EQ_EXPR, type, exp,
4250 fold_convert (etype, low));
4252 if (integer_zerop (low))
4254 if (! TYPE_UNSIGNED (etype))
4256 etype = lang_hooks.types.unsigned_type (etype);
4257 high = fold_convert (etype, high);
4258 exp = fold_convert (etype, exp);
4260 return build_range_check (type, exp, 1, 0, high);
4263 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
4264 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
4266 unsigned HOST_WIDE_INT lo;
4270 prec = TYPE_PRECISION (etype);
4271 if (prec <= HOST_BITS_PER_WIDE_INT)
4274 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
4278 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
4279 lo = (unsigned HOST_WIDE_INT) -1;
4282 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
4284 if (TYPE_UNSIGNED (etype))
4286 etype = lang_hooks.types.signed_type (etype);
4287 exp = fold_convert (etype, exp);
4289 return fold_build2 (GT_EXPR, type, exp,
4290 build_int_cst (etype, 0));
4294 /* Optimize (c>=low) && (c<=high) into (c-low>=0) && (c-low<=high-low).
4295 This requires wrap-around arithmetics for the type of the expression. */
4296 switch (TREE_CODE (etype))
4299 /* There is no requirement that LOW be within the range of ETYPE
4300 if the latter is a subtype. It must, however, be within the base
4301 type of ETYPE. So be sure we do the subtraction in that type. */
4302 if (TREE_TYPE (etype))
4303 etype = TREE_TYPE (etype);
4308 etype = lang_hooks.types.type_for_size (TYPE_PRECISION (etype),
4309 TYPE_UNSIGNED (etype));
4316 /* If we don't have wrap-around arithmetics upfront, try to force it. */
4317 if (TREE_CODE (etype) == INTEGER_TYPE
4318 && !TYPE_OVERFLOW_WRAPS (etype))
4320 tree utype, minv, maxv;
4322 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
4323 for the type in question, as we rely on this here. */
4324 utype = lang_hooks.types.unsigned_type (etype);
4325 maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
4326 maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
4327 integer_one_node, 1);
4328 minv = fold_convert (utype, TYPE_MIN_VALUE (etype));
4330 if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
4337 high = fold_convert (etype, high);
4338 low = fold_convert (etype, low);
4339 exp = fold_convert (etype, exp);
4341 value = const_binop (MINUS_EXPR, high, low, 0);
4343 if (value != 0 && !TREE_OVERFLOW (value))
4344 return build_range_check (type,
4345 fold_build2 (MINUS_EXPR, etype, exp, low),
4346 1, build_int_cst (etype, 0), value);
4351 /* Return the predecessor of VAL in its type, handling the infinite case. */
4354 range_predecessor (tree val)
4356 tree type = TREE_TYPE (val);
4358 if (INTEGRAL_TYPE_P (type)
4359 && operand_equal_p (val, TYPE_MIN_VALUE (type), 0))
4362 return range_binop (MINUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4365 /* Return the successor of VAL in its type, handling the infinite case. */
4368 range_successor (tree val)
4370 tree type = TREE_TYPE (val);
4372 if (INTEGRAL_TYPE_P (type)
4373 && operand_equal_p (val, TYPE_MAX_VALUE (type), 0))
4376 return range_binop (PLUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4379 /* Given two ranges, see if we can merge them into one. Return 1 if we
4380 can, 0 if we can't. Set the output range into the specified parameters. */
4383 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
4384 tree high0, int in1_p, tree low1, tree high1)
4392 int lowequal = ((low0 == 0 && low1 == 0)
4393 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4394 low0, 0, low1, 0)));
4395 int highequal = ((high0 == 0 && high1 == 0)
4396 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4397 high0, 1, high1, 1)));
4399 /* Make range 0 be the range that starts first, or ends last if they
4400 start at the same value. Swap them if it isn't. */
4401 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
4404 && integer_onep (range_binop (GT_EXPR, integer_type_node,
4405 high1, 1, high0, 1))))
4407 temp = in0_p, in0_p = in1_p, in1_p = temp;
4408 tem = low0, low0 = low1, low1 = tem;
4409 tem = high0, high0 = high1, high1 = tem;
4412 /* Now flag two cases, whether the ranges are disjoint or whether the
4413 second range is totally subsumed in the first. Note that the tests
4414 below are simplified by the ones above. */
4415 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
4416 high0, 1, low1, 0));
4417 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
4418 high1, 1, high0, 1));
4420 /* We now have four cases, depending on whether we are including or
4421 excluding the two ranges. */
4424 /* If they don't overlap, the result is false. If the second range
4425 is a subset it is the result. Otherwise, the range is from the start
4426 of the second to the end of the first. */
4428 in_p = 0, low = high = 0;
4430 in_p = 1, low = low1, high = high1;
4432 in_p = 1, low = low1, high = high0;
4435 else if (in0_p && ! in1_p)
4437 /* If they don't overlap, the result is the first range. If they are
4438 equal, the result is false. If the second range is a subset of the
4439 first, and the ranges begin at the same place, we go from just after
4440 the end of the second range to the end of the first. If the second
4441 range is not a subset of the first, or if it is a subset and both
4442 ranges end at the same place, the range starts at the start of the
4443 first range and ends just before the second range.
4444 Otherwise, we can't describe this as a single range. */
4446 in_p = 1, low = low0, high = high0;
4447 else if (lowequal && highequal)
4448 in_p = 0, low = high = 0;
4449 else if (subset && lowequal)
4451 low = range_successor (high1);
4456 /* We are in the weird situation where high0 > high1 but
4457 high1 has no successor. Punt. */
4461 else if (! subset || highequal)
4464 high = range_predecessor (low1);
4468 /* low0 < low1 but low1 has no predecessor. Punt. */
4476 else if (! in0_p && in1_p)
4478 /* If they don't overlap, the result is the second range. If the second
4479 is a subset of the first, the result is false. Otherwise,
4480 the range starts just after the first range and ends at the
4481 end of the second. */
4483 in_p = 1, low = low1, high = high1;
4484 else if (subset || highequal)
4485 in_p = 0, low = high = 0;
4488 low = range_successor (high0);
4493 /* high1 > high0 but high0 has no successor. Punt. */
4501 /* The case where we are excluding both ranges. Here the complex case
4502 is if they don't overlap. In that case, the only time we have a
4503 range is if they are adjacent. If the second is a subset of the
4504 first, the result is the first. Otherwise, the range to exclude
4505 starts at the beginning of the first range and ends at the end of the
4509 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
4510 range_successor (high0),
4512 in_p = 0, low = low0, high = high1;
4515 /* Canonicalize - [min, x] into - [-, x]. */
4516 if (low0 && TREE_CODE (low0) == INTEGER_CST)
4517 switch (TREE_CODE (TREE_TYPE (low0)))
4520 if (TYPE_PRECISION (TREE_TYPE (low0))
4521 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0))))
4525 if (tree_int_cst_equal (low0,
4526 TYPE_MIN_VALUE (TREE_TYPE (low0))))
4530 if (TYPE_UNSIGNED (TREE_TYPE (low0))
4531 && integer_zerop (low0))
4538 /* Canonicalize - [x, max] into - [x, -]. */
4539 if (high1 && TREE_CODE (high1) == INTEGER_CST)
4540 switch (TREE_CODE (TREE_TYPE (high1)))
4543 if (TYPE_PRECISION (TREE_TYPE (high1))
4544 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1))))
4548 if (tree_int_cst_equal (high1,
4549 TYPE_MAX_VALUE (TREE_TYPE (high1))))
4553 if (TYPE_UNSIGNED (TREE_TYPE (high1))
4554 && integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
4556 integer_one_node, 1)))
4563 /* The ranges might be also adjacent between the maximum and
4564 minimum values of the given type. For
4565 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
4566 return + [x + 1, y - 1]. */
4567 if (low0 == 0 && high1 == 0)
4569 low = range_successor (high0);
4570 high = range_predecessor (low1);
4571 if (low == 0 || high == 0)
4581 in_p = 0, low = low0, high = high0;
4583 in_p = 0, low = low0, high = high1;
4586 *pin_p = in_p, *plow = low, *phigh = high;
4591 /* Subroutine of fold, looking inside expressions of the form
4592 A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
4593 of the COND_EXPR. This function is being used also to optimize
4594 A op B ? C : A, by reversing the comparison first.
4596 Return a folded expression whose code is not a COND_EXPR
4597 anymore, or NULL_TREE if no folding opportunity is found. */
4600 fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
4602 enum tree_code comp_code = TREE_CODE (arg0);
4603 tree arg00 = TREE_OPERAND (arg0, 0);
4604 tree arg01 = TREE_OPERAND (arg0, 1);
4605 tree arg1_type = TREE_TYPE (arg1);
4611 /* If we have A op 0 ? A : -A, consider applying the following
4614 A == 0? A : -A same as -A
4615 A != 0? A : -A same as A
4616 A >= 0? A : -A same as abs (A)
4617 A > 0? A : -A same as abs (A)
4618 A <= 0? A : -A same as -abs (A)
4619 A < 0? A : -A same as -abs (A)
4621 None of these transformations work for modes with signed
4622 zeros. If A is +/-0, the first two transformations will
4623 change the sign of the result (from +0 to -0, or vice
4624 versa). The last four will fix the sign of the result,
4625 even though the original expressions could be positive or
4626 negative, depending on the sign of A.
4628 Note that all these transformations are correct if A is
4629 NaN, since the two alternatives (A and -A) are also NaNs. */
4630 if ((FLOAT_TYPE_P (TREE_TYPE (arg01))
4631 ? real_zerop (arg01)
4632 : integer_zerop (arg01))
4633 && ((TREE_CODE (arg2) == NEGATE_EXPR
4634 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
4635 /* In the case that A is of the form X-Y, '-A' (arg2) may
4636 have already been folded to Y-X, check for that. */
4637 || (TREE_CODE (arg1) == MINUS_EXPR
4638 && TREE_CODE (arg2) == MINUS_EXPR
4639 && operand_equal_p (TREE_OPERAND (arg1, 0),
4640 TREE_OPERAND (arg2, 1), 0)
4641 && operand_equal_p (TREE_OPERAND (arg1, 1),
4642 TREE_OPERAND (arg2, 0), 0))))
4647 tem = fold_convert (arg1_type, arg1);
4648 return pedantic_non_lvalue (fold_convert (type, negate_expr (tem)));
4651 return pedantic_non_lvalue (fold_convert (type, arg1));
4654 if (flag_trapping_math)
4659 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4660 arg1 = fold_convert (lang_hooks.types.signed_type
4661 (TREE_TYPE (arg1)), arg1);
4662 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
4663 return pedantic_non_lvalue (fold_convert (type, tem));
4666 if (flag_trapping_math)
4670 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4671 arg1 = fold_convert (lang_hooks.types.signed_type
4672 (TREE_TYPE (arg1)), arg1);
4673 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
4674 return negate_expr (fold_convert (type, tem));
4676 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
4680 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
4681 A == 0 ? A : 0 is always 0 unless A is -0. Note that
4682 both transformations are correct when A is NaN: A != 0
4683 is then true, and A == 0 is false. */
4685 if (integer_zerop (arg01) && integer_zerop (arg2))
4687 if (comp_code == NE_EXPR)
4688 return pedantic_non_lvalue (fold_convert (type, arg1));
4689 else if (comp_code == EQ_EXPR)
4690 return build_int_cst (type, 0);
4693 /* Try some transformations of A op B ? A : B.
4695 A == B? A : B same as B
4696 A != B? A : B same as A
4697 A >= B? A : B same as max (A, B)
4698 A > B? A : B same as max (B, A)
4699 A <= B? A : B same as min (A, B)
4700 A < B? A : B same as min (B, A)
4702 As above, these transformations don't work in the presence
4703 of signed zeros. For example, if A and B are zeros of
4704 opposite sign, the first two transformations will change
4705 the sign of the result. In the last four, the original
4706 expressions give different results for (A=+0, B=-0) and
4707 (A=-0, B=+0), but the transformed expressions do not.
4709 The first two transformations are correct if either A or B
4710 is a NaN. In the first transformation, the condition will
4711 be false, and B will indeed be chosen. In the case of the
4712 second transformation, the condition A != B will be true,
4713 and A will be chosen.
4715 The conversions to max() and min() are not correct if B is
4716 a number and A is not. The conditions in the original
4717 expressions will be false, so all four give B. The min()
4718 and max() versions would give a NaN instead. */
4719 if (operand_equal_for_comparison_p (arg01, arg2, arg00)
4720 /* Avoid these transformations if the COND_EXPR may be used
4721 as an lvalue in the C++ front-end. PR c++/19199. */
4723 || (strcmp (lang_hooks.name, "GNU C++") != 0
4724 && strcmp (lang_hooks.name, "GNU Objective-C++") != 0)
4725 || ! maybe_lvalue_p (arg1)
4726 || ! maybe_lvalue_p (arg2)))
4728 tree comp_op0 = arg00;
4729 tree comp_op1 = arg01;
4730 tree comp_type = TREE_TYPE (comp_op0);
4732 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
4733 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
4743 return pedantic_non_lvalue (fold_convert (type, arg2));
4745 return pedantic_non_lvalue (fold_convert (type, arg1));
4750 /* In C++ a ?: expression can be an lvalue, so put the
4751 operand which will be used if they are equal first
4752 so that we can convert this back to the
4753 corresponding COND_EXPR. */
4754 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4756 comp_op0 = fold_convert (comp_type, comp_op0);
4757 comp_op1 = fold_convert (comp_type, comp_op1);
4758 tem = (comp_code == LE_EXPR || comp_code == UNLE_EXPR)
4759 ? fold_build2 (MIN_EXPR, comp_type, comp_op0, comp_op1)
4760 : fold_build2 (MIN_EXPR, comp_type, comp_op1, comp_op0);
4761 return pedantic_non_lvalue (fold_convert (type, tem));
4768 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4770 comp_op0 = fold_convert (comp_type, comp_op0);
4771 comp_op1 = fold_convert (comp_type, comp_op1);
4772 tem = (comp_code == GE_EXPR || comp_code == UNGE_EXPR)
4773 ? fold_build2 (MAX_EXPR, comp_type, comp_op0, comp_op1)
4774 : fold_build2 (MAX_EXPR, comp_type, comp_op1, comp_op0);
4775 return pedantic_non_lvalue (fold_convert (type, tem));
4779 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4780 return pedantic_non_lvalue (fold_convert (type, arg2));
4783 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4784 return pedantic_non_lvalue (fold_convert (type, arg1));
4787 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
4792 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
4793 we might still be able to simplify this. For example,
4794 if C1 is one less or one more than C2, this might have started
4795 out as a MIN or MAX and been transformed by this function.
4796 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
4798 if (INTEGRAL_TYPE_P (type)
4799 && TREE_CODE (arg01) == INTEGER_CST
4800 && TREE_CODE (arg2) == INTEGER_CST)
4804 /* We can replace A with C1 in this case. */
4805 arg1 = fold_convert (type, arg01);
4806 return fold_build3 (COND_EXPR, type, arg0, arg1, arg2);
4809 /* If C1 is C2 + 1, this is min(A, C2). */
4810 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4812 && operand_equal_p (arg01,
4813 const_binop (PLUS_EXPR, arg2,
4814 integer_one_node, 0),
4816 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
4821 /* If C1 is C2 - 1, this is min(A, C2). */
4822 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
4824 && operand_equal_p (arg01,
4825 const_binop (MINUS_EXPR, arg2,
4826 integer_one_node, 0),
4828 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
4833 /* If C1 is C2 - 1, this is max(A, C2). */
4834 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
4836 && operand_equal_p (arg01,
4837 const_binop (MINUS_EXPR, arg2,
4838 integer_one_node, 0),
4840 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
4845 /* If C1 is C2 + 1, this is max(A, C2). */
4846 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4848 && operand_equal_p (arg01,
4849 const_binop (PLUS_EXPR, arg2,
4850 integer_one_node, 0),
4852 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
4866 #ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
4867 #define LOGICAL_OP_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
4870 /* EXP is some logical combination of boolean tests. See if we can
4871 merge it into some range test. Return the new tree if so. */
4874 fold_range_test (enum tree_code code, tree type, tree op0, tree op1)
4876 int or_op = (code == TRUTH_ORIF_EXPR
4877 || code == TRUTH_OR_EXPR);
4878 int in0_p, in1_p, in_p;
4879 tree low0, low1, low, high0, high1, high;
4880 bool strict_overflow_p = false;
4881 tree lhs = make_range (op0, &in0_p, &low0, &high0, &strict_overflow_p);
4882 tree rhs = make_range (op1, &in1_p, &low1, &high1, &strict_overflow_p);
4884 const char * const warnmsg = G_("assuming signed overflow does not occur "
4885 "when simplifying range test");
4887 /* If this is an OR operation, invert both sides; we will invert
4888 again at the end. */
4890 in0_p = ! in0_p, in1_p = ! in1_p;
4892 /* If both expressions are the same, if we can merge the ranges, and we
4893 can build the range test, return it or it inverted. If one of the
4894 ranges is always true or always false, consider it to be the same
4895 expression as the other. */
4896 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
4897 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
4899 && 0 != (tem = (build_range_check (type,
4901 : rhs != 0 ? rhs : integer_zero_node,
4904 if (strict_overflow_p)
4905 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
4906 return or_op ? invert_truthvalue (tem) : tem;
4909 /* On machines where the branch cost is expensive, if this is a
4910 short-circuited branch and the underlying object on both sides
4911 is the same, make a non-short-circuit operation. */
4912 else if (LOGICAL_OP_NON_SHORT_CIRCUIT
4913 && lhs != 0 && rhs != 0
4914 && (code == TRUTH_ANDIF_EXPR
4915 || code == TRUTH_ORIF_EXPR)
4916 && operand_equal_p (lhs, rhs, 0))
4918 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
4919 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
4920 which cases we can't do this. */
4921 if (simple_operand_p (lhs))
4922 return build2 (code == TRUTH_ANDIF_EXPR
4923 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
4926 else if (lang_hooks.decls.global_bindings_p () == 0
4927 && ! CONTAINS_PLACEHOLDER_P (lhs))
4929 tree common = save_expr (lhs);
4931 if (0 != (lhs = build_range_check (type, common,
4932 or_op ? ! in0_p : in0_p,
4934 && (0 != (rhs = build_range_check (type, common,
4935 or_op ? ! in1_p : in1_p,
4938 if (strict_overflow_p)
4939 fold_overflow_warning (warnmsg,
4940 WARN_STRICT_OVERFLOW_COMPARISON);
4941 return build2 (code == TRUTH_ANDIF_EXPR
4942 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
4951 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
4952 bit value. Arrange things so the extra bits will be set to zero if and
4953 only if C is signed-extended to its full width. If MASK is nonzero,
4954 it is an INTEGER_CST that should be AND'ed with the extra bits. */
4957 unextend (tree c, int p, int unsignedp, tree mask)
4959 tree type = TREE_TYPE (c);
4960 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
4963 if (p == modesize || unsignedp)
4966 /* We work by getting just the sign bit into the low-order bit, then
4967 into the high-order bit, then sign-extend. We then XOR that value
4969 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
4970 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
4972 /* We must use a signed type in order to get an arithmetic right shift.
4973 However, we must also avoid introducing accidental overflows, so that
4974 a subsequent call to integer_zerop will work. Hence we must
4975 do the type conversion here. At this point, the constant is either
4976 zero or one, and the conversion to a signed type can never overflow.
4977 We could get an overflow if this conversion is done anywhere else. */
4978 if (TYPE_UNSIGNED (type))
4979 temp = fold_convert (lang_hooks.types.signed_type (type), temp);
4981 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
4982 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
4984 temp = const_binop (BIT_AND_EXPR, temp,
4985 fold_convert (TREE_TYPE (c), mask), 0);
4986 /* If necessary, convert the type back to match the type of C. */
4987 if (TYPE_UNSIGNED (type))
4988 temp = fold_convert (type, temp);
4990 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
4993 /* Find ways of folding logical expressions of LHS and RHS:
4994 Try to merge two comparisons to the same innermost item.
4995 Look for range tests like "ch >= '0' && ch <= '9'".
4996 Look for combinations of simple terms on machines with expensive branches
4997 and evaluate the RHS unconditionally.
4999 For example, if we have p->a == 2 && p->b == 4 and we can make an
5000 object large enough to span both A and B, we can do this with a comparison
5001 against the object ANDed with the a mask.
5003 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
5004 operations to do this with one comparison.
5006 We check for both normal comparisons and the BIT_AND_EXPRs made this by
5007 function and the one above.
5009 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
5010 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
5012 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
5015 We return the simplified tree or 0 if no optimization is possible. */
5018 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
5020 /* If this is the "or" of two comparisons, we can do something if
5021 the comparisons are NE_EXPR. If this is the "and", we can do something
5022 if the comparisons are EQ_EXPR. I.e.,
5023 (a->b == 2 && a->c == 4) can become (a->new == NEW).
5025 WANTED_CODE is this operation code. For single bit fields, we can
5026 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
5027 comparison for one-bit fields. */
5029 enum tree_code wanted_code;
5030 enum tree_code lcode, rcode;
5031 tree ll_arg, lr_arg, rl_arg, rr_arg;
5032 tree ll_inner, lr_inner, rl_inner, rr_inner;
5033 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
5034 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
5035 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
5036 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
5037 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
5038 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
5039 enum machine_mode lnmode, rnmode;
5040 tree ll_mask, lr_mask, rl_mask, rr_mask;
5041 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
5042 tree l_const, r_const;
5043 tree lntype, rntype, result;
5044 int first_bit, end_bit;
5046 tree orig_lhs = lhs, orig_rhs = rhs;
5047 enum tree_code orig_code = code;
5049 /* Start by getting the comparison codes. Fail if anything is volatile.
5050 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
5051 it were surrounded with a NE_EXPR. */
5053 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
5056 lcode = TREE_CODE (lhs);
5057 rcode = TREE_CODE (rhs);
5059 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
5061 lhs = build2 (NE_EXPR, truth_type, lhs,
5062 build_int_cst (TREE_TYPE (lhs), 0));
5066 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
5068 rhs = build2 (NE_EXPR, truth_type, rhs,
5069 build_int_cst (TREE_TYPE (rhs), 0));
5073 if (TREE_CODE_CLASS (lcode) != tcc_comparison
5074 || TREE_CODE_CLASS (rcode) != tcc_comparison)
5077 ll_arg = TREE_OPERAND (lhs, 0);
5078 lr_arg = TREE_OPERAND (lhs, 1);
5079 rl_arg = TREE_OPERAND (rhs, 0);
5080 rr_arg = TREE_OPERAND (rhs, 1);
5082 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
5083 if (simple_operand_p (ll_arg)
5084 && simple_operand_p (lr_arg))
5087 if (operand_equal_p (ll_arg, rl_arg, 0)
5088 && operand_equal_p (lr_arg, rr_arg, 0))
5090 result = combine_comparisons (code, lcode, rcode,
5091 truth_type, ll_arg, lr_arg);
5095 else if (operand_equal_p (ll_arg, rr_arg, 0)
5096 && operand_equal_p (lr_arg, rl_arg, 0))
5098 result = combine_comparisons (code, lcode,
5099 swap_tree_comparison (rcode),
5100 truth_type, ll_arg, lr_arg);
5106 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
5107 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
5109 /* If the RHS can be evaluated unconditionally and its operands are
5110 simple, it wins to evaluate the RHS unconditionally on machines
5111 with expensive branches. In this case, this isn't a comparison
5112 that can be merged. Avoid doing this if the RHS is a floating-point
5113 comparison since those can trap. */
5115 if (BRANCH_COST >= 2
5116 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
5117 && simple_operand_p (rl_arg)
5118 && simple_operand_p (rr_arg))
5120 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
5121 if (code == TRUTH_OR_EXPR
5122 && lcode == NE_EXPR && integer_zerop (lr_arg)
5123 && rcode == NE_EXPR && integer_zerop (rr_arg)
5124 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
5125 return build2 (NE_EXPR, truth_type,
5126 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5128 build_int_cst (TREE_TYPE (ll_arg), 0));
5130 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
5131 if (code == TRUTH_AND_EXPR
5132 && lcode == EQ_EXPR && integer_zerop (lr_arg)
5133 && rcode == EQ_EXPR && integer_zerop (rr_arg)
5134 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
5135 return build2 (EQ_EXPR, truth_type,
5136 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5138 build_int_cst (TREE_TYPE (ll_arg), 0));
5140 if (LOGICAL_OP_NON_SHORT_CIRCUIT)
5142 if (code != orig_code || lhs != orig_lhs || rhs != orig_rhs)
5143 return build2 (code, truth_type, lhs, rhs);
5148 /* See if the comparisons can be merged. Then get all the parameters for
5151 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
5152 || (rcode != EQ_EXPR && rcode != NE_EXPR))
5156 ll_inner = decode_field_reference (ll_arg,
5157 &ll_bitsize, &ll_bitpos, &ll_mode,
5158 &ll_unsignedp, &volatilep, &ll_mask,
5160 lr_inner = decode_field_reference (lr_arg,
5161 &lr_bitsize, &lr_bitpos, &lr_mode,
5162 &lr_unsignedp, &volatilep, &lr_mask,
5164 rl_inner = decode_field_reference (rl_arg,
5165 &rl_bitsize, &rl_bitpos, &rl_mode,
5166 &rl_unsignedp, &volatilep, &rl_mask,
5168 rr_inner = decode_field_reference (rr_arg,
5169 &rr_bitsize, &rr_bitpos, &rr_mode,
5170 &rr_unsignedp, &volatilep, &rr_mask,
5173 /* It must be true that the inner operation on the lhs of each
5174 comparison must be the same if we are to be able to do anything.
5175 Then see if we have constants. If not, the same must be true for
5177 if (volatilep || ll_inner == 0 || rl_inner == 0
5178 || ! operand_equal_p (ll_inner, rl_inner, 0))
5181 if (TREE_CODE (lr_arg) == INTEGER_CST
5182 && TREE_CODE (rr_arg) == INTEGER_CST)
5183 l_const = lr_arg, r_const = rr_arg;
5184 else if (lr_inner == 0 || rr_inner == 0
5185 || ! operand_equal_p (lr_inner, rr_inner, 0))
5188 l_const = r_const = 0;
5190 /* If either comparison code is not correct for our logical operation,
5191 fail. However, we can convert a one-bit comparison against zero into
5192 the opposite comparison against that bit being set in the field. */
5194 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
5195 if (lcode != wanted_code)
5197 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
5199 /* Make the left operand unsigned, since we are only interested
5200 in the value of one bit. Otherwise we are doing the wrong
5209 /* This is analogous to the code for l_const above. */
5210 if (rcode != wanted_code)
5212 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
5221 /* After this point all optimizations will generate bit-field
5222 references, which we might not want. */
5223 if (! lang_hooks.can_use_bit_fields_p ())
5226 /* See if we can find a mode that contains both fields being compared on
5227 the left. If we can't, fail. Otherwise, update all constants and masks
5228 to be relative to a field of that size. */
5229 first_bit = MIN (ll_bitpos, rl_bitpos);
5230 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
5231 lnmode = get_best_mode (end_bit - first_bit, first_bit,
5232 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
5234 if (lnmode == VOIDmode)
5237 lnbitsize = GET_MODE_BITSIZE (lnmode);
5238 lnbitpos = first_bit & ~ (lnbitsize - 1);
5239 lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
5240 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
5242 if (BYTES_BIG_ENDIAN)
5244 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
5245 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
5248 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
5249 size_int (xll_bitpos), 0);
5250 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
5251 size_int (xrl_bitpos), 0);
5255 l_const = fold_convert (lntype, l_const);
5256 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
5257 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
5258 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
5259 fold_build1 (BIT_NOT_EXPR,
5263 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5265 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5270 r_const = fold_convert (lntype, r_const);
5271 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
5272 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
5273 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
5274 fold_build1 (BIT_NOT_EXPR,
5278 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5280 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5284 /* If the right sides are not constant, do the same for it. Also,
5285 disallow this optimization if a size or signedness mismatch occurs
5286 between the left and right sides. */
5289 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
5290 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
5291 /* Make sure the two fields on the right
5292 correspond to the left without being swapped. */
5293 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
5296 first_bit = MIN (lr_bitpos, rr_bitpos);
5297 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
5298 rnmode = get_best_mode (end_bit - first_bit, first_bit,
5299 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
5301 if (rnmode == VOIDmode)
5304 rnbitsize = GET_MODE_BITSIZE (rnmode);
5305 rnbitpos = first_bit & ~ (rnbitsize - 1);
5306 rntype = lang_hooks.types.type_for_size (rnbitsize, 1);
5307 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
5309 if (BYTES_BIG_ENDIAN)
5311 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
5312 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
5315 lr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, lr_mask),
5316 size_int (xlr_bitpos), 0);
5317 rr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, rr_mask),
5318 size_int (xrr_bitpos), 0);
5320 /* Make a mask that corresponds to both fields being compared.
5321 Do this for both items being compared. If the operands are the
5322 same size and the bits being compared are in the same position
5323 then we can do this by masking both and comparing the masked
5325 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
5326 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
5327 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
5329 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
5330 ll_unsignedp || rl_unsignedp);
5331 if (! all_ones_mask_p (ll_mask, lnbitsize))
5332 lhs = build2 (BIT_AND_EXPR, lntype, lhs, ll_mask);
5334 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
5335 lr_unsignedp || rr_unsignedp);
5336 if (! all_ones_mask_p (lr_mask, rnbitsize))
5337 rhs = build2 (BIT_AND_EXPR, rntype, rhs, lr_mask);
5339 return build2 (wanted_code, truth_type, lhs, rhs);
5342 /* There is still another way we can do something: If both pairs of
5343 fields being compared are adjacent, we may be able to make a wider
5344 field containing them both.
5346 Note that we still must mask the lhs/rhs expressions. Furthermore,
5347 the mask must be shifted to account for the shift done by
5348 make_bit_field_ref. */
5349 if ((ll_bitsize + ll_bitpos == rl_bitpos
5350 && lr_bitsize + lr_bitpos == rr_bitpos)
5351 || (ll_bitpos == rl_bitpos + rl_bitsize
5352 && lr_bitpos == rr_bitpos + rr_bitsize))
5356 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
5357 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
5358 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
5359 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
5361 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
5362 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
5363 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
5364 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
5366 /* Convert to the smaller type before masking out unwanted bits. */
5368 if (lntype != rntype)
5370 if (lnbitsize > rnbitsize)
5372 lhs = fold_convert (rntype, lhs);
5373 ll_mask = fold_convert (rntype, ll_mask);
5376 else if (lnbitsize < rnbitsize)
5378 rhs = fold_convert (lntype, rhs);
5379 lr_mask = fold_convert (lntype, lr_mask);
5384 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
5385 lhs = build2 (BIT_AND_EXPR, type, lhs, ll_mask);
5387 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
5388 rhs = build2 (BIT_AND_EXPR, type, rhs, lr_mask);
5390 return build2 (wanted_code, truth_type, lhs, rhs);
5396 /* Handle the case of comparisons with constants. If there is something in
5397 common between the masks, those bits of the constants must be the same.
5398 If not, the condition is always false. Test for this to avoid generating
5399 incorrect code below. */
5400 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
5401 if (! integer_zerop (result)
5402 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
5403 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
5405 if (wanted_code == NE_EXPR)
5407 warning (0, "%<or%> of unmatched not-equal tests is always 1");
5408 return constant_boolean_node (true, truth_type);
5412 warning (0, "%<and%> of mutually exclusive equal-tests is always 0");
5413 return constant_boolean_node (false, truth_type);
5417 /* Construct the expression we will return. First get the component
5418 reference we will make. Unless the mask is all ones the width of
5419 that field, perform the mask operation. Then compare with the
5421 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
5422 ll_unsignedp || rl_unsignedp);
5424 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
5425 if (! all_ones_mask_p (ll_mask, lnbitsize))
5426 result = build2 (BIT_AND_EXPR, lntype, result, ll_mask);
5428 return build2 (wanted_code, truth_type, result,
5429 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
5432 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
5436 optimize_minmax_comparison (enum tree_code code, tree type, tree op0, tree op1)
5439 enum tree_code op_code;
5440 tree comp_const = op1;
5442 int consts_equal, consts_lt;
5445 STRIP_SIGN_NOPS (arg0);
5447 op_code = TREE_CODE (arg0);
5448 minmax_const = TREE_OPERAND (arg0, 1);
5449 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
5450 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
5451 inner = TREE_OPERAND (arg0, 0);
5453 /* If something does not permit us to optimize, return the original tree. */
5454 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
5455 || TREE_CODE (comp_const) != INTEGER_CST
5456 || TREE_CONSTANT_OVERFLOW (comp_const)
5457 || TREE_CODE (minmax_const) != INTEGER_CST
5458 || TREE_CONSTANT_OVERFLOW (minmax_const))
5461 /* Now handle all the various comparison codes. We only handle EQ_EXPR
5462 and GT_EXPR, doing the rest with recursive calls using logical
5466 case NE_EXPR: case LT_EXPR: case LE_EXPR:
5468 tree tem = optimize_minmax_comparison (invert_tree_comparison (code, false),
5471 return invert_truthvalue (tem);
5477 fold_build2 (TRUTH_ORIF_EXPR, type,
5478 optimize_minmax_comparison
5479 (EQ_EXPR, type, arg0, comp_const),
5480 optimize_minmax_comparison
5481 (GT_EXPR, type, arg0, comp_const));
5484 if (op_code == MAX_EXPR && consts_equal)
5485 /* MAX (X, 0) == 0 -> X <= 0 */
5486 return fold_build2 (LE_EXPR, type, inner, comp_const);
5488 else if (op_code == MAX_EXPR && consts_lt)
5489 /* MAX (X, 0) == 5 -> X == 5 */
5490 return fold_build2 (EQ_EXPR, type, inner, comp_const);
5492 else if (op_code == MAX_EXPR)
5493 /* MAX (X, 0) == -1 -> false */
5494 return omit_one_operand (type, integer_zero_node, inner);
5496 else if (consts_equal)
5497 /* MIN (X, 0) == 0 -> X >= 0 */
5498 return fold_build2 (GE_EXPR, type, inner, comp_const);
5501 /* MIN (X, 0) == 5 -> false */
5502 return omit_one_operand (type, integer_zero_node, inner);
5505 /* MIN (X, 0) == -1 -> X == -1 */
5506 return fold_build2 (EQ_EXPR, type, inner, comp_const);
5509 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
5510 /* MAX (X, 0) > 0 -> X > 0
5511 MAX (X, 0) > 5 -> X > 5 */
5512 return fold_build2 (GT_EXPR, type, inner, comp_const);
5514 else if (op_code == MAX_EXPR)
5515 /* MAX (X, 0) > -1 -> true */
5516 return omit_one_operand (type, integer_one_node, inner);
5518 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
5519 /* MIN (X, 0) > 0 -> false
5520 MIN (X, 0) > 5 -> false */
5521 return omit_one_operand (type, integer_zero_node, inner);
5524 /* MIN (X, 0) > -1 -> X > -1 */
5525 return fold_build2 (GT_EXPR, type, inner, comp_const);
5532 /* T is an integer expression that is being multiplied, divided, or taken a
5533 modulus (CODE says which and what kind of divide or modulus) by a
5534 constant C. See if we can eliminate that operation by folding it with
5535 other operations already in T. WIDE_TYPE, if non-null, is a type that
5536 should be used for the computation if wider than our type.
5538 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
5539 (X * 2) + (Y * 4). We must, however, be assured that either the original
5540 expression would not overflow or that overflow is undefined for the type
5541 in the language in question.
5543 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
5544 the machine has a multiply-accumulate insn or that this is part of an
5545 addressing calculation.
5547 If we return a non-null expression, it is an equivalent form of the
5548 original computation, but need not be in the original type.
5550 We set *STRICT_OVERFLOW_P to true if the return values depends on
5551 signed overflow being undefined. Otherwise we do not change
5552 *STRICT_OVERFLOW_P. */
5555 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type,
5556 bool *strict_overflow_p)
5558 /* To avoid exponential search depth, refuse to allow recursion past
5559 three levels. Beyond that (1) it's highly unlikely that we'll find
5560 something interesting and (2) we've probably processed it before
5561 when we built the inner expression. */
5570 ret = extract_muldiv_1 (t, c, code, wide_type, strict_overflow_p);
5577 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type,
5578 bool *strict_overflow_p)
5580 tree type = TREE_TYPE (t);
5581 enum tree_code tcode = TREE_CODE (t);
5582 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
5583 > GET_MODE_SIZE (TYPE_MODE (type)))
5584 ? wide_type : type);
5586 int same_p = tcode == code;
5587 tree op0 = NULL_TREE, op1 = NULL_TREE;
5588 bool sub_strict_overflow_p;
5590 /* Don't deal with constants of zero here; they confuse the code below. */
5591 if (integer_zerop (c))
5594 if (TREE_CODE_CLASS (tcode) == tcc_unary)
5595 op0 = TREE_OPERAND (t, 0);
5597 if (TREE_CODE_CLASS (tcode) == tcc_binary)
5598 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
5600 /* Note that we need not handle conditional operations here since fold
5601 already handles those cases. So just do arithmetic here. */
5605 /* For a constant, we can always simplify if we are a multiply
5606 or (for divide and modulus) if it is a multiple of our constant. */
5607 if (code == MULT_EXPR
5608 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
5609 return const_binop (code, fold_convert (ctype, t),
5610 fold_convert (ctype, c), 0);
5613 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
5614 /* If op0 is an expression ... */
5615 if ((COMPARISON_CLASS_P (op0)
5616 || UNARY_CLASS_P (op0)
5617 || BINARY_CLASS_P (op0)
5618 || EXPRESSION_CLASS_P (op0))
5619 /* ... and is unsigned, and its type is smaller than ctype,
5620 then we cannot pass through as widening. */
5621 && ((TYPE_UNSIGNED (TREE_TYPE (op0))
5622 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
5623 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
5624 && (GET_MODE_SIZE (TYPE_MODE (ctype))
5625 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
5626 /* ... or this is a truncation (t is narrower than op0),
5627 then we cannot pass through this narrowing. */
5628 || (GET_MODE_SIZE (TYPE_MODE (type))
5629 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
5630 /* ... or signedness changes for division or modulus,
5631 then we cannot pass through this conversion. */
5632 || (code != MULT_EXPR
5633 && (TYPE_UNSIGNED (ctype)
5634 != TYPE_UNSIGNED (TREE_TYPE (op0))))))
5637 /* Pass the constant down and see if we can make a simplification. If
5638 we can, replace this expression with the inner simplification for
5639 possible later conversion to our or some other type. */
5640 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
5641 && TREE_CODE (t2) == INTEGER_CST
5642 && ! TREE_CONSTANT_OVERFLOW (t2)
5643 && (0 != (t1 = extract_muldiv (op0, t2, code,
5645 ? ctype : NULL_TREE,
5646 strict_overflow_p))))
5651 /* If widening the type changes it from signed to unsigned, then we
5652 must avoid building ABS_EXPR itself as unsigned. */
5653 if (TYPE_UNSIGNED (ctype) && !TYPE_UNSIGNED (type))
5655 tree cstype = (*lang_hooks.types.signed_type) (ctype);
5656 if ((t1 = extract_muldiv (op0, c, code, cstype, strict_overflow_p))
5659 t1 = fold_build1 (tcode, cstype, fold_convert (cstype, t1));
5660 return fold_convert (ctype, t1);
5664 /* If the constant is negative, we cannot simplify this. */
5665 if (tree_int_cst_sgn (c) == -1)
5669 if ((t1 = extract_muldiv (op0, c, code, wide_type, strict_overflow_p))
5671 return fold_build1 (tcode, ctype, fold_convert (ctype, t1));
5674 case MIN_EXPR: case MAX_EXPR:
5675 /* If widening the type changes the signedness, then we can't perform
5676 this optimization as that changes the result. */
5677 if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
5680 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
5681 sub_strict_overflow_p = false;
5682 if ((t1 = extract_muldiv (op0, c, code, wide_type,
5683 &sub_strict_overflow_p)) != 0
5684 && (t2 = extract_muldiv (op1, c, code, wide_type,
5685 &sub_strict_overflow_p)) != 0)
5687 if (tree_int_cst_sgn (c) < 0)
5688 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
5689 if (sub_strict_overflow_p)
5690 *strict_overflow_p = true;
5691 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
5692 fold_convert (ctype, t2));
5696 case LSHIFT_EXPR: case RSHIFT_EXPR:
5697 /* If the second operand is constant, this is a multiplication
5698 or floor division, by a power of two, so we can treat it that
5699 way unless the multiplier or divisor overflows. Signed
5700 left-shift overflow is implementation-defined rather than
5701 undefined in C90, so do not convert signed left shift into
5703 if (TREE_CODE (op1) == INTEGER_CST
5704 && (tcode == RSHIFT_EXPR || TYPE_UNSIGNED (TREE_TYPE (op0)))
5705 /* const_binop may not detect overflow correctly,
5706 so check for it explicitly here. */
5707 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
5708 && TREE_INT_CST_HIGH (op1) == 0
5709 && 0 != (t1 = fold_convert (ctype,
5710 const_binop (LSHIFT_EXPR,
5713 && ! TREE_OVERFLOW (t1))
5714 return extract_muldiv (build2 (tcode == LSHIFT_EXPR
5715 ? MULT_EXPR : FLOOR_DIV_EXPR,
5716 ctype, fold_convert (ctype, op0), t1),
5717 c, code, wide_type, strict_overflow_p);
5720 case PLUS_EXPR: case MINUS_EXPR:
5721 /* See if we can eliminate the operation on both sides. If we can, we
5722 can return a new PLUS or MINUS. If we can't, the only remaining
5723 cases where we can do anything are if the second operand is a
5725 sub_strict_overflow_p = false;
5726 t1 = extract_muldiv (op0, c, code, wide_type, &sub_strict_overflow_p);
5727 t2 = extract_muldiv (op1, c, code, wide_type, &sub_strict_overflow_p);
5728 if (t1 != 0 && t2 != 0
5729 && (code == MULT_EXPR
5730 /* If not multiplication, we can only do this if both operands
5731 are divisible by c. */
5732 || (multiple_of_p (ctype, op0, c)
5733 && multiple_of_p (ctype, op1, c))))
5735 if (sub_strict_overflow_p)
5736 *strict_overflow_p = true;
5737 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
5738 fold_convert (ctype, t2));
5741 /* If this was a subtraction, negate OP1 and set it to be an addition.
5742 This simplifies the logic below. */
5743 if (tcode == MINUS_EXPR)
5744 tcode = PLUS_EXPR, op1 = negate_expr (op1);
5746 if (TREE_CODE (op1) != INTEGER_CST)
5749 /* If either OP1 or C are negative, this optimization is not safe for
5750 some of the division and remainder types while for others we need
5751 to change the code. */
5752 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
5754 if (code == CEIL_DIV_EXPR)
5755 code = FLOOR_DIV_EXPR;
5756 else if (code == FLOOR_DIV_EXPR)
5757 code = CEIL_DIV_EXPR;
5758 else if (code != MULT_EXPR
5759 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
5763 /* If it's a multiply or a division/modulus operation of a multiple
5764 of our constant, do the operation and verify it doesn't overflow. */
5765 if (code == MULT_EXPR
5766 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5768 op1 = const_binop (code, fold_convert (ctype, op1),
5769 fold_convert (ctype, c), 0);
5770 /* We allow the constant to overflow with wrapping semantics. */
5772 || (TREE_OVERFLOW (op1) && !TYPE_OVERFLOW_WRAPS (ctype)))
5778 /* If we have an unsigned type is not a sizetype, we cannot widen
5779 the operation since it will change the result if the original
5780 computation overflowed. */
5781 if (TYPE_UNSIGNED (ctype)
5782 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
5786 /* If we were able to eliminate our operation from the first side,
5787 apply our operation to the second side and reform the PLUS. */
5788 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
5789 return fold_build2 (tcode, ctype, fold_convert (ctype, t1), op1);
5791 /* The last case is if we are a multiply. In that case, we can
5792 apply the distributive law to commute the multiply and addition
5793 if the multiplication of the constants doesn't overflow. */
5794 if (code == MULT_EXPR)
5795 return fold_build2 (tcode, ctype,
5796 fold_build2 (code, ctype,
5797 fold_convert (ctype, op0),
5798 fold_convert (ctype, c)),
5804 /* We have a special case here if we are doing something like
5805 (C * 8) % 4 since we know that's zero. */
5806 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
5807 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
5808 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
5809 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5810 return omit_one_operand (type, integer_zero_node, op0);
5812 /* ... fall through ... */
5814 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
5815 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
5816 /* If we can extract our operation from the LHS, do so and return a
5817 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
5818 do something only if the second operand is a constant. */
5820 && (t1 = extract_muldiv (op0, c, code, wide_type,
5821 strict_overflow_p)) != 0)
5822 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
5823 fold_convert (ctype, op1));
5824 else if (tcode == MULT_EXPR && code == MULT_EXPR
5825 && (t1 = extract_muldiv (op1, c, code, wide_type,
5826 strict_overflow_p)) != 0)
5827 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
5828 fold_convert (ctype, t1));
5829 else if (TREE_CODE (op1) != INTEGER_CST)
5832 /* If these are the same operation types, we can associate them
5833 assuming no overflow. */
5835 && 0 != (t1 = const_binop (MULT_EXPR, fold_convert (ctype, op1),
5836 fold_convert (ctype, c), 0))
5837 && ! TREE_OVERFLOW (t1))
5838 return fold_build2 (tcode, ctype, fold_convert (ctype, op0), t1);
5840 /* If these operations "cancel" each other, we have the main
5841 optimizations of this pass, which occur when either constant is a
5842 multiple of the other, in which case we replace this with either an
5843 operation or CODE or TCODE.
5845 If we have an unsigned type that is not a sizetype, we cannot do
5846 this since it will change the result if the original computation
5848 if ((TYPE_OVERFLOW_UNDEFINED (ctype)
5849 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
5850 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
5851 || (tcode == MULT_EXPR
5852 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
5853 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
5855 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5857 if (TYPE_OVERFLOW_UNDEFINED (ctype))
5858 *strict_overflow_p = true;
5859 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
5860 fold_convert (ctype,
5861 const_binop (TRUNC_DIV_EXPR,
5864 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
5866 if (TYPE_OVERFLOW_UNDEFINED (ctype))
5867 *strict_overflow_p = true;
5868 return fold_build2 (code, ctype, fold_convert (ctype, op0),
5869 fold_convert (ctype,
5870 const_binop (TRUNC_DIV_EXPR,
5883 /* Return a node which has the indicated constant VALUE (either 0 or
5884 1), and is of the indicated TYPE. */
5887 constant_boolean_node (int value, tree type)
5889 if (type == integer_type_node)
5890 return value ? integer_one_node : integer_zero_node;
5891 else if (type == boolean_type_node)
5892 return value ? boolean_true_node : boolean_false_node;
5894 return build_int_cst (type, value);
5898 /* Return true if expr looks like an ARRAY_REF and set base and
5899 offset to the appropriate trees. If there is no offset,
5900 offset is set to NULL_TREE. Base will be canonicalized to
5901 something you can get the element type from using
5902 TREE_TYPE (TREE_TYPE (base)). Offset will be the offset
5903 in bytes to the base. */
5906 extract_array_ref (tree expr, tree *base, tree *offset)
5908 /* One canonical form is a PLUS_EXPR with the first
5909 argument being an ADDR_EXPR with a possible NOP_EXPR
5911 if (TREE_CODE (expr) == PLUS_EXPR)
5913 tree op0 = TREE_OPERAND (expr, 0);
5914 tree inner_base, dummy1;
5915 /* Strip NOP_EXPRs here because the C frontends and/or
5916 folders present us (int *)&x.a + 4B possibly. */
5918 if (extract_array_ref (op0, &inner_base, &dummy1))
5921 if (dummy1 == NULL_TREE)
5922 *offset = TREE_OPERAND (expr, 1);
5924 *offset = fold_build2 (PLUS_EXPR, TREE_TYPE (expr),
5925 dummy1, TREE_OPERAND (expr, 1));
5929 /* Other canonical form is an ADDR_EXPR of an ARRAY_REF,
5930 which we transform into an ADDR_EXPR with appropriate
5931 offset. For other arguments to the ADDR_EXPR we assume
5932 zero offset and as such do not care about the ADDR_EXPR
5933 type and strip possible nops from it. */
5934 else if (TREE_CODE (expr) == ADDR_EXPR)
5936 tree op0 = TREE_OPERAND (expr, 0);
5937 if (TREE_CODE (op0) == ARRAY_REF)
5939 tree idx = TREE_OPERAND (op0, 1);
5940 *base = TREE_OPERAND (op0, 0);
5941 *offset = fold_build2 (MULT_EXPR, TREE_TYPE (idx), idx,
5942 array_ref_element_size (op0));
5946 /* Handle array-to-pointer decay as &a. */
5947 if (TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE)
5948 *base = TREE_OPERAND (expr, 0);
5951 *offset = NULL_TREE;
5955 /* The next canonical form is a VAR_DECL with POINTER_TYPE. */
5956 else if (SSA_VAR_P (expr)
5957 && TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5960 *offset = NULL_TREE;
5968 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
5969 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
5970 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
5971 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
5972 COND is the first argument to CODE; otherwise (as in the example
5973 given here), it is the second argument. TYPE is the type of the
5974 original expression. Return NULL_TREE if no simplification is
5978 fold_binary_op_with_conditional_arg (enum tree_code code,
5979 tree type, tree op0, tree op1,
5980 tree cond, tree arg, int cond_first_p)
5982 tree cond_type = cond_first_p ? TREE_TYPE (op0) : TREE_TYPE (op1);
5983 tree arg_type = cond_first_p ? TREE_TYPE (op1) : TREE_TYPE (op0);
5984 tree test, true_value, false_value;
5985 tree lhs = NULL_TREE;
5986 tree rhs = NULL_TREE;
5988 /* This transformation is only worthwhile if we don't have to wrap
5989 arg in a SAVE_EXPR, and the operation can be simplified on at least
5990 one of the branches once its pushed inside the COND_EXPR. */
5991 if (!TREE_CONSTANT (arg))
5994 if (TREE_CODE (cond) == COND_EXPR)
5996 test = TREE_OPERAND (cond, 0);
5997 true_value = TREE_OPERAND (cond, 1);
5998 false_value = TREE_OPERAND (cond, 2);
5999 /* If this operand throws an expression, then it does not make
6000 sense to try to perform a logical or arithmetic operation
6002 if (VOID_TYPE_P (TREE_TYPE (true_value)))
6004 if (VOID_TYPE_P (TREE_TYPE (false_value)))
6009 tree testtype = TREE_TYPE (cond);
6011 true_value = constant_boolean_node (true, testtype);
6012 false_value = constant_boolean_node (false, testtype);
6015 arg = fold_convert (arg_type, arg);
6018 true_value = fold_convert (cond_type, true_value);
6020 lhs = fold_build2 (code, type, true_value, arg);
6022 lhs = fold_build2 (code, type, arg, true_value);
6026 false_value = fold_convert (cond_type, false_value);
6028 rhs = fold_build2 (code, type, false_value, arg);
6030 rhs = fold_build2 (code, type, arg, false_value);
6033 test = fold_build3 (COND_EXPR, type, test, lhs, rhs);
6034 return fold_convert (type, test);
6038 /* Subroutine of fold() that checks for the addition of +/- 0.0.
6040 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
6041 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
6042 ADDEND is the same as X.
6044 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
6045 and finite. The problematic cases are when X is zero, and its mode
6046 has signed zeros. In the case of rounding towards -infinity,
6047 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
6048 modes, X + 0 is not the same as X because -0 + 0 is 0. */
6051 fold_real_zero_addition_p (tree type, tree addend, int negate)
6053 if (!real_zerop (addend))
6056 /* Don't allow the fold with -fsignaling-nans. */
6057 if (HONOR_SNANS (TYPE_MODE (type)))
6060 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
6061 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
6064 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
6065 if (TREE_CODE (addend) == REAL_CST
6066 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
6069 /* The mode has signed zeros, and we have to honor their sign.
6070 In this situation, there is only one case we can return true for.
6071 X - 0 is the same as X unless rounding towards -infinity is
6073 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
6076 /* Subroutine of fold() that checks comparisons of built-in math
6077 functions against real constants.
6079 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
6080 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
6081 is the type of the result and ARG0 and ARG1 are the operands of the
6082 comparison. ARG1 must be a TREE_REAL_CST.
6084 The function returns the constant folded tree if a simplification
6085 can be made, and NULL_TREE otherwise. */
6088 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
6089 tree type, tree arg0, tree arg1)
6093 if (BUILTIN_SQRT_P (fcode))
6095 tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
6096 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
6098 c = TREE_REAL_CST (arg1);
6099 if (REAL_VALUE_NEGATIVE (c))
6101 /* sqrt(x) < y is always false, if y is negative. */
6102 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
6103 return omit_one_operand (type, integer_zero_node, arg);
6105 /* sqrt(x) > y is always true, if y is negative and we
6106 don't care about NaNs, i.e. negative values of x. */
6107 if (code == NE_EXPR || !HONOR_NANS (mode))
6108 return omit_one_operand (type, integer_one_node, arg);
6110 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
6111 return fold_build2 (GE_EXPR, type, arg,
6112 build_real (TREE_TYPE (arg), dconst0));
6114 else if (code == GT_EXPR || code == GE_EXPR)
6118 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
6119 real_convert (&c2, mode, &c2);
6121 if (REAL_VALUE_ISINF (c2))
6123 /* sqrt(x) > y is x == +Inf, when y is very large. */
6124 if (HONOR_INFINITIES (mode))
6125 return fold_build2 (EQ_EXPR, type, arg,
6126 build_real (TREE_TYPE (arg), c2));
6128 /* sqrt(x) > y is always false, when y is very large
6129 and we don't care about infinities. */
6130 return omit_one_operand (type, integer_zero_node, arg);
6133 /* sqrt(x) > c is the same as x > c*c. */
6134 return fold_build2 (code, type, arg,
6135 build_real (TREE_TYPE (arg), c2));
6137 else if (code == LT_EXPR || code == LE_EXPR)
6141 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
6142 real_convert (&c2, mode, &c2);
6144 if (REAL_VALUE_ISINF (c2))
6146 /* sqrt(x) < y is always true, when y is a very large
6147 value and we don't care about NaNs or Infinities. */
6148 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
6149 return omit_one_operand (type, integer_one_node, arg);
6151 /* sqrt(x) < y is x != +Inf when y is very large and we
6152 don't care about NaNs. */
6153 if (! HONOR_NANS (mode))
6154 return fold_build2 (NE_EXPR, type, arg,
6155 build_real (TREE_TYPE (arg), c2));
6157 /* sqrt(x) < y is x >= 0 when y is very large and we
6158 don't care about Infinities. */
6159 if (! HONOR_INFINITIES (mode))
6160 return fold_build2 (GE_EXPR, type, arg,
6161 build_real (TREE_TYPE (arg), dconst0));
6163 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
6164 if (lang_hooks.decls.global_bindings_p () != 0
6165 || CONTAINS_PLACEHOLDER_P (arg))
6168 arg = save_expr (arg);
6169 return fold_build2 (TRUTH_ANDIF_EXPR, type,
6170 fold_build2 (GE_EXPR, type, arg,
6171 build_real (TREE_TYPE (arg),
6173 fold_build2 (NE_EXPR, type, arg,
6174 build_real (TREE_TYPE (arg),
6178 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
6179 if (! HONOR_NANS (mode))
6180 return fold_build2 (code, type, arg,
6181 build_real (TREE_TYPE (arg), c2));
6183 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
6184 if (lang_hooks.decls.global_bindings_p () == 0
6185 && ! CONTAINS_PLACEHOLDER_P (arg))
6187 arg = save_expr (arg);
6188 return fold_build2 (TRUTH_ANDIF_EXPR, type,
6189 fold_build2 (GE_EXPR, type, arg,
6190 build_real (TREE_TYPE (arg),
6192 fold_build2 (code, type, arg,
6193 build_real (TREE_TYPE (arg),
6202 /* Subroutine of fold() that optimizes comparisons against Infinities,
6203 either +Inf or -Inf.
6205 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6206 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6207 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6209 The function returns the constant folded tree if a simplification
6210 can be made, and NULL_TREE otherwise. */
6213 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6215 enum machine_mode mode;
6216 REAL_VALUE_TYPE max;
6220 mode = TYPE_MODE (TREE_TYPE (arg0));
6222 /* For negative infinity swap the sense of the comparison. */
6223 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
6225 code = swap_tree_comparison (code);
6230 /* x > +Inf is always false, if with ignore sNANs. */
6231 if (HONOR_SNANS (mode))
6233 return omit_one_operand (type, integer_zero_node, arg0);
6236 /* x <= +Inf is always true, if we don't case about NaNs. */
6237 if (! HONOR_NANS (mode))
6238 return omit_one_operand (type, integer_one_node, arg0);
6240 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
6241 if (lang_hooks.decls.global_bindings_p () == 0
6242 && ! CONTAINS_PLACEHOLDER_P (arg0))
6244 arg0 = save_expr (arg0);
6245 return fold_build2 (EQ_EXPR, type, arg0, arg0);
6251 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
6252 real_maxval (&max, neg, mode);
6253 return fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6254 arg0, build_real (TREE_TYPE (arg0), max));
6257 /* x < +Inf is always equal to x <= DBL_MAX. */
6258 real_maxval (&max, neg, mode);
6259 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6260 arg0, build_real (TREE_TYPE (arg0), max));
6263 /* x != +Inf is always equal to !(x > DBL_MAX). */
6264 real_maxval (&max, neg, mode);
6265 if (! HONOR_NANS (mode))
6266 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6267 arg0, build_real (TREE_TYPE (arg0), max));
6269 /* The transformation below creates non-gimple code and thus is
6270 not appropriate if we are in gimple form. */
6274 temp = fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6275 arg0, build_real (TREE_TYPE (arg0), max));
6276 return fold_build1 (TRUTH_NOT_EXPR, type, temp);
6285 /* Subroutine of fold() that optimizes comparisons of a division by
6286 a nonzero integer constant against an integer constant, i.e.
6289 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6290 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6291 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6293 The function returns the constant folded tree if a simplification
6294 can be made, and NULL_TREE otherwise. */
6297 fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6299 tree prod, tmp, hi, lo;
6300 tree arg00 = TREE_OPERAND (arg0, 0);
6301 tree arg01 = TREE_OPERAND (arg0, 1);
6302 unsigned HOST_WIDE_INT lpart;
6303 HOST_WIDE_INT hpart;
6304 bool unsigned_p = TYPE_UNSIGNED (TREE_TYPE (arg0));
6308 /* We have to do this the hard way to detect unsigned overflow.
6309 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
6310 overflow = mul_double_with_sign (TREE_INT_CST_LOW (arg01),
6311 TREE_INT_CST_HIGH (arg01),
6312 TREE_INT_CST_LOW (arg1),
6313 TREE_INT_CST_HIGH (arg1),
6314 &lpart, &hpart, unsigned_p);
6315 prod = build_int_cst_wide (TREE_TYPE (arg00), lpart, hpart);
6316 prod = force_fit_type (prod, -1, overflow, false);
6317 neg_overflow = false;
6321 tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
6324 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
6325 overflow = add_double_with_sign (TREE_INT_CST_LOW (prod),
6326 TREE_INT_CST_HIGH (prod),
6327 TREE_INT_CST_LOW (tmp),
6328 TREE_INT_CST_HIGH (tmp),
6329 &lpart, &hpart, unsigned_p);
6330 hi = build_int_cst_wide (TREE_TYPE (arg00), lpart, hpart);
6331 hi = force_fit_type (hi, -1, overflow | TREE_OVERFLOW (prod),
6332 TREE_CONSTANT_OVERFLOW (prod));
6334 else if (tree_int_cst_sgn (arg01) >= 0)
6336 tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
6337 switch (tree_int_cst_sgn (arg1))
6340 neg_overflow = true;
6341 lo = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6346 lo = fold_negate_const (tmp, TREE_TYPE (arg0));
6351 hi = int_const_binop (PLUS_EXPR, prod, tmp, 0);
6361 /* A negative divisor reverses the relational operators. */
6362 code = swap_tree_comparison (code);
6364 tmp = int_const_binop (PLUS_EXPR, arg01, integer_one_node, 0);
6365 switch (tree_int_cst_sgn (arg1))
6368 hi = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6373 hi = fold_negate_const (tmp, TREE_TYPE (arg0));
6378 neg_overflow = true;
6379 lo = int_const_binop (PLUS_EXPR, prod, tmp, 0);
6391 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6392 return omit_one_operand (type, integer_zero_node, arg00);
6393 if (TREE_OVERFLOW (hi))
6394 return fold_build2 (GE_EXPR, type, arg00, lo);
6395 if (TREE_OVERFLOW (lo))
6396 return fold_build2 (LE_EXPR, type, arg00, hi);
6397 return build_range_check (type, arg00, 1, lo, hi);
6400 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6401 return omit_one_operand (type, integer_one_node, arg00);
6402 if (TREE_OVERFLOW (hi))
6403 return fold_build2 (LT_EXPR, type, arg00, lo);
6404 if (TREE_OVERFLOW (lo))
6405 return fold_build2 (GT_EXPR, type, arg00, hi);
6406 return build_range_check (type, arg00, 0, lo, hi);
6409 if (TREE_OVERFLOW (lo))
6411 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6412 return omit_one_operand (type, tmp, arg00);
6414 return fold_build2 (LT_EXPR, type, arg00, lo);
6417 if (TREE_OVERFLOW (hi))
6419 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6420 return omit_one_operand (type, tmp, arg00);
6422 return fold_build2 (LE_EXPR, type, arg00, hi);
6425 if (TREE_OVERFLOW (hi))
6427 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6428 return omit_one_operand (type, tmp, arg00);
6430 return fold_build2 (GT_EXPR, type, arg00, hi);
6433 if (TREE_OVERFLOW (lo))
6435 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6436 return omit_one_operand (type, tmp, arg00);
6438 return fold_build2 (GE_EXPR, type, arg00, lo);
6448 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6449 equality/inequality test, then return a simplified form of the test
6450 using a sign testing. Otherwise return NULL. TYPE is the desired
6454 fold_single_bit_test_into_sign_test (enum tree_code code, tree arg0, tree arg1,
6457 /* If this is testing a single bit, we can optimize the test. */
6458 if ((code == NE_EXPR || code == EQ_EXPR)
6459 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6460 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6462 /* If we have (A & C) != 0 where C is the sign bit of A, convert
6463 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
6464 tree arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
6466 if (arg00 != NULL_TREE
6467 /* This is only a win if casting to a signed type is cheap,
6468 i.e. when arg00's type is not a partial mode. */
6469 && TYPE_PRECISION (TREE_TYPE (arg00))
6470 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00))))
6472 tree stype = lang_hooks.types.signed_type (TREE_TYPE (arg00));
6473 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
6474 result_type, fold_convert (stype, arg00),
6475 build_int_cst (stype, 0));
6482 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6483 equality/inequality test, then return a simplified form of
6484 the test using shifts and logical operations. Otherwise return
6485 NULL. TYPE is the desired result type. */
6488 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
6491 /* If this is testing a single bit, we can optimize the test. */
6492 if ((code == NE_EXPR || code == EQ_EXPR)
6493 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6494 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6496 tree inner = TREE_OPERAND (arg0, 0);
6497 tree type = TREE_TYPE (arg0);
6498 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
6499 enum machine_mode operand_mode = TYPE_MODE (type);
6501 tree signed_type, unsigned_type, intermediate_type;
6504 /* First, see if we can fold the single bit test into a sign-bit
6506 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1,
6511 /* Otherwise we have (A & C) != 0 where C is a single bit,
6512 convert that into ((A >> C2) & 1). Where C2 = log2(C).
6513 Similarly for (A & C) == 0. */
6515 /* If INNER is a right shift of a constant and it plus BITNUM does
6516 not overflow, adjust BITNUM and INNER. */
6517 if (TREE_CODE (inner) == RSHIFT_EXPR
6518 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
6519 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
6520 && bitnum < TYPE_PRECISION (type)
6521 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
6522 bitnum - TYPE_PRECISION (type)))
6524 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
6525 inner = TREE_OPERAND (inner, 0);
6528 /* If we are going to be able to omit the AND below, we must do our
6529 operations as unsigned. If we must use the AND, we have a choice.
6530 Normally unsigned is faster, but for some machines signed is. */
6531 #ifdef LOAD_EXTEND_OP
6532 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND
6533 && !flag_syntax_only) ? 0 : 1;
6538 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
6539 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
6540 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
6541 inner = fold_convert (intermediate_type, inner);
6544 inner = build2 (RSHIFT_EXPR, intermediate_type,
6545 inner, size_int (bitnum));
6547 if (code == EQ_EXPR)
6548 inner = fold_build2 (BIT_XOR_EXPR, intermediate_type,
6549 inner, integer_one_node);
6551 /* Put the AND last so it can combine with more things. */
6552 inner = build2 (BIT_AND_EXPR, intermediate_type,
6553 inner, integer_one_node);
6555 /* Make sure to return the proper type. */
6556 inner = fold_convert (result_type, inner);
6563 /* Check whether we are allowed to reorder operands arg0 and arg1,
6564 such that the evaluation of arg1 occurs before arg0. */
6567 reorder_operands_p (tree arg0, tree arg1)
6569 if (! flag_evaluation_order)
6571 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
6573 return ! TREE_SIDE_EFFECTS (arg0)
6574 && ! TREE_SIDE_EFFECTS (arg1);
6577 /* Test whether it is preferable two swap two operands, ARG0 and
6578 ARG1, for example because ARG0 is an integer constant and ARG1
6579 isn't. If REORDER is true, only recommend swapping if we can
6580 evaluate the operands in reverse order. */
6583 tree_swap_operands_p (tree arg0, tree arg1, bool reorder)
6585 STRIP_SIGN_NOPS (arg0);
6586 STRIP_SIGN_NOPS (arg1);
6588 if (TREE_CODE (arg1) == INTEGER_CST)
6590 if (TREE_CODE (arg0) == INTEGER_CST)
6593 if (TREE_CODE (arg1) == REAL_CST)
6595 if (TREE_CODE (arg0) == REAL_CST)
6598 if (TREE_CODE (arg1) == COMPLEX_CST)
6600 if (TREE_CODE (arg0) == COMPLEX_CST)
6603 if (TREE_CONSTANT (arg1))
6605 if (TREE_CONSTANT (arg0))
6611 if (reorder && flag_evaluation_order
6612 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
6620 /* It is preferable to swap two SSA_NAME to ensure a canonical form
6621 for commutative and comparison operators. Ensuring a canonical
6622 form allows the optimizers to find additional redundancies without
6623 having to explicitly check for both orderings. */
6624 if (TREE_CODE (arg0) == SSA_NAME
6625 && TREE_CODE (arg1) == SSA_NAME
6626 && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
6632 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where
6633 ARG0 is extended to a wider type. */
6636 fold_widened_comparison (enum tree_code code, tree type, tree arg0, tree arg1)
6638 tree arg0_unw = get_unwidened (arg0, NULL_TREE);
6640 tree shorter_type, outer_type;
6644 if (arg0_unw == arg0)
6646 shorter_type = TREE_TYPE (arg0_unw);
6648 #ifdef HAVE_canonicalize_funcptr_for_compare
6649 /* Disable this optimization if we're casting a function pointer
6650 type on targets that require function pointer canonicalization. */
6651 if (HAVE_canonicalize_funcptr_for_compare
6652 && TREE_CODE (shorter_type) == POINTER_TYPE
6653 && TREE_CODE (TREE_TYPE (shorter_type)) == FUNCTION_TYPE)
6657 if (TYPE_PRECISION (TREE_TYPE (arg0)) <= TYPE_PRECISION (shorter_type))
6660 arg1_unw = get_unwidened (arg1, NULL_TREE);
6662 /* If possible, express the comparison in the shorter mode. */
6663 if ((code == EQ_EXPR || code == NE_EXPR
6664 || TYPE_UNSIGNED (TREE_TYPE (arg0)) == TYPE_UNSIGNED (shorter_type))
6665 && (TREE_TYPE (arg1_unw) == shorter_type
6666 || (TYPE_PRECISION (shorter_type)
6667 >= TYPE_PRECISION (TREE_TYPE (arg1_unw)))
6668 || (TREE_CODE (arg1_unw) == INTEGER_CST
6669 && (TREE_CODE (shorter_type) == INTEGER_TYPE
6670 || TREE_CODE (shorter_type) == BOOLEAN_TYPE)
6671 && int_fits_type_p (arg1_unw, shorter_type))))
6672 return fold_build2 (code, type, arg0_unw,
6673 fold_convert (shorter_type, arg1_unw));
6675 if (TREE_CODE (arg1_unw) != INTEGER_CST
6676 || TREE_CODE (shorter_type) != INTEGER_TYPE
6677 || !int_fits_type_p (arg1_unw, shorter_type))
6680 /* If we are comparing with the integer that does not fit into the range
6681 of the shorter type, the result is known. */
6682 outer_type = TREE_TYPE (arg1_unw);
6683 min = lower_bound_in_type (outer_type, shorter_type);
6684 max = upper_bound_in_type (outer_type, shorter_type);
6686 above = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6688 below = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6695 return omit_one_operand (type, integer_zero_node, arg0);
6700 return omit_one_operand (type, integer_one_node, arg0);
6706 return omit_one_operand (type, integer_one_node, arg0);
6708 return omit_one_operand (type, integer_zero_node, arg0);
6713 return omit_one_operand (type, integer_zero_node, arg0);
6715 return omit_one_operand (type, integer_one_node, arg0);
6724 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where for
6725 ARG0 just the signedness is changed. */
6728 fold_sign_changed_comparison (enum tree_code code, tree type,
6729 tree arg0, tree arg1)
6731 tree arg0_inner, tmp;
6732 tree inner_type, outer_type;
6734 if (TREE_CODE (arg0) != NOP_EXPR
6735 && TREE_CODE (arg0) != CONVERT_EXPR)
6738 outer_type = TREE_TYPE (arg0);
6739 arg0_inner = TREE_OPERAND (arg0, 0);
6740 inner_type = TREE_TYPE (arg0_inner);
6742 #ifdef HAVE_canonicalize_funcptr_for_compare
6743 /* Disable this optimization if we're casting a function pointer
6744 type on targets that require function pointer canonicalization. */
6745 if (HAVE_canonicalize_funcptr_for_compare
6746 && TREE_CODE (inner_type) == POINTER_TYPE
6747 && TREE_CODE (TREE_TYPE (inner_type)) == FUNCTION_TYPE)
6751 if (TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
6754 if (TREE_CODE (arg1) != INTEGER_CST
6755 && !((TREE_CODE (arg1) == NOP_EXPR
6756 || TREE_CODE (arg1) == CONVERT_EXPR)
6757 && TREE_TYPE (TREE_OPERAND (arg1, 0)) == inner_type))
6760 if (TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
6765 if (TREE_CODE (arg1) == INTEGER_CST)
6767 tmp = build_int_cst_wide (inner_type,
6768 TREE_INT_CST_LOW (arg1),
6769 TREE_INT_CST_HIGH (arg1));
6770 arg1 = force_fit_type (tmp, 0,
6771 TREE_OVERFLOW (arg1),
6772 TREE_CONSTANT_OVERFLOW (arg1));
6775 arg1 = fold_convert (inner_type, arg1);
6777 return fold_build2 (code, type, arg0_inner, arg1);
6780 /* Tries to replace &a[idx] CODE s * delta with &a[idx CODE delta], if s is
6781 step of the array. Reconstructs s and delta in the case of s * delta
6782 being an integer constant (and thus already folded).
6783 ADDR is the address. MULT is the multiplicative expression.
6784 If the function succeeds, the new address expression is returned. Otherwise
6785 NULL_TREE is returned. */
6788 try_move_mult_to_index (enum tree_code code, tree addr, tree op1)
6790 tree s, delta, step;
6791 tree ref = TREE_OPERAND (addr, 0), pref;
6795 /* Canonicalize op1 into a possibly non-constant delta
6796 and an INTEGER_CST s. */
6797 if (TREE_CODE (op1) == MULT_EXPR)
6799 tree arg0 = TREE_OPERAND (op1, 0), arg1 = TREE_OPERAND (op1, 1);
6804 if (TREE_CODE (arg0) == INTEGER_CST)
6809 else if (TREE_CODE (arg1) == INTEGER_CST)
6817 else if (TREE_CODE (op1) == INTEGER_CST)
6824 /* Simulate we are delta * 1. */
6826 s = integer_one_node;
6829 for (;; ref = TREE_OPERAND (ref, 0))
6831 if (TREE_CODE (ref) == ARRAY_REF)
6833 itype = TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (ref, 0)));
6837 step = array_ref_element_size (ref);
6838 if (TREE_CODE (step) != INTEGER_CST)
6843 if (! tree_int_cst_equal (step, s))
6848 /* Try if delta is a multiple of step. */
6849 tree tmp = div_if_zero_remainder (EXACT_DIV_EXPR, delta, step);
6858 if (!handled_component_p (ref))
6862 /* We found the suitable array reference. So copy everything up to it,
6863 and replace the index. */
6865 pref = TREE_OPERAND (addr, 0);
6866 ret = copy_node (pref);
6871 pref = TREE_OPERAND (pref, 0);
6872 TREE_OPERAND (pos, 0) = copy_node (pref);
6873 pos = TREE_OPERAND (pos, 0);
6876 TREE_OPERAND (pos, 1) = fold_build2 (code, itype,
6877 fold_convert (itype,
6878 TREE_OPERAND (pos, 1)),
6879 fold_convert (itype, delta));
6881 return fold_build1 (ADDR_EXPR, TREE_TYPE (addr), ret);
6885 /* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
6886 means A >= Y && A != MAX, but in this case we know that
6887 A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
6890 fold_to_nonsharp_ineq_using_bound (tree ineq, tree bound)
6892 tree a, typea, type = TREE_TYPE (ineq), a1, diff, y;
6894 if (TREE_CODE (bound) == LT_EXPR)
6895 a = TREE_OPERAND (bound, 0);
6896 else if (TREE_CODE (bound) == GT_EXPR)
6897 a = TREE_OPERAND (bound, 1);
6901 typea = TREE_TYPE (a);
6902 if (!INTEGRAL_TYPE_P (typea)
6903 && !POINTER_TYPE_P (typea))
6906 if (TREE_CODE (ineq) == LT_EXPR)
6908 a1 = TREE_OPERAND (ineq, 1);
6909 y = TREE_OPERAND (ineq, 0);
6911 else if (TREE_CODE (ineq) == GT_EXPR)
6913 a1 = TREE_OPERAND (ineq, 0);
6914 y = TREE_OPERAND (ineq, 1);
6919 if (TREE_TYPE (a1) != typea)
6922 diff = fold_build2 (MINUS_EXPR, typea, a1, a);
6923 if (!integer_onep (diff))
6926 return fold_build2 (GE_EXPR, type, a, y);
6929 /* Fold a sum or difference of at least one multiplication.
6930 Returns the folded tree or NULL if no simplification could be made. */
6933 fold_plusminus_mult_expr (enum tree_code code, tree type, tree arg0, tree arg1)
6935 tree arg00, arg01, arg10, arg11;
6936 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
6938 /* (A * C) +- (B * C) -> (A+-B) * C.
6939 (A * C) +- A -> A * (C+-1).
6940 We are most concerned about the case where C is a constant,
6941 but other combinations show up during loop reduction. Since
6942 it is not difficult, try all four possibilities. */
6944 if (TREE_CODE (arg0) == MULT_EXPR)
6946 arg00 = TREE_OPERAND (arg0, 0);
6947 arg01 = TREE_OPERAND (arg0, 1);
6952 arg01 = build_one_cst (type);
6954 if (TREE_CODE (arg1) == MULT_EXPR)
6956 arg10 = TREE_OPERAND (arg1, 0);
6957 arg11 = TREE_OPERAND (arg1, 1);
6962 arg11 = build_one_cst (type);
6966 if (operand_equal_p (arg01, arg11, 0))
6967 same = arg01, alt0 = arg00, alt1 = arg10;
6968 else if (operand_equal_p (arg00, arg10, 0))
6969 same = arg00, alt0 = arg01, alt1 = arg11;
6970 else if (operand_equal_p (arg00, arg11, 0))
6971 same = arg00, alt0 = arg01, alt1 = arg10;
6972 else if (operand_equal_p (arg01, arg10, 0))
6973 same = arg01, alt0 = arg00, alt1 = arg11;
6975 /* No identical multiplicands; see if we can find a common
6976 power-of-two factor in non-power-of-two multiplies. This
6977 can help in multi-dimensional array access. */
6978 else if (host_integerp (arg01, 0)
6979 && host_integerp (arg11, 0))
6981 HOST_WIDE_INT int01, int11, tmp;
6984 int01 = TREE_INT_CST_LOW (arg01);
6985 int11 = TREE_INT_CST_LOW (arg11);
6987 /* Move min of absolute values to int11. */
6988 if ((int01 >= 0 ? int01 : -int01)
6989 < (int11 >= 0 ? int11 : -int11))
6991 tmp = int01, int01 = int11, int11 = tmp;
6992 alt0 = arg00, arg00 = arg10, arg10 = alt0;
6999 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
7001 alt0 = fold_build2 (MULT_EXPR, TREE_TYPE (arg00), arg00,
7002 build_int_cst (TREE_TYPE (arg00),
7007 maybe_same = alt0, alt0 = alt1, alt1 = maybe_same;
7012 return fold_build2 (MULT_EXPR, type,
7013 fold_build2 (code, type,
7014 fold_convert (type, alt0),
7015 fold_convert (type, alt1)),
7016 fold_convert (type, same));
7021 /* Subroutine of native_encode_expr. Encode the INTEGER_CST
7022 specified by EXPR into the buffer PTR of length LEN bytes.
7023 Return the number of bytes placed in the buffer, or zero
7027 native_encode_int (tree expr, unsigned char *ptr, int len)
7029 tree type = TREE_TYPE (expr);
7030 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7031 int byte, offset, word, words;
7032 unsigned char value;
7034 if (total_bytes > len)
7036 words = total_bytes / UNITS_PER_WORD;
7038 for (byte = 0; byte < total_bytes; byte++)
7040 int bitpos = byte * BITS_PER_UNIT;
7041 if (bitpos < HOST_BITS_PER_WIDE_INT)
7042 value = (unsigned char) (TREE_INT_CST_LOW (expr) >> bitpos);
7044 value = (unsigned char) (TREE_INT_CST_HIGH (expr)
7045 >> (bitpos - HOST_BITS_PER_WIDE_INT));
7047 if (total_bytes > UNITS_PER_WORD)
7049 word = byte / UNITS_PER_WORD;
7050 if (WORDS_BIG_ENDIAN)
7051 word = (words - 1) - word;
7052 offset = word * UNITS_PER_WORD;
7053 if (BYTES_BIG_ENDIAN)
7054 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7056 offset += byte % UNITS_PER_WORD;
7059 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7060 ptr[offset] = value;
7066 /* Subroutine of native_encode_expr. Encode the REAL_CST
7067 specified by EXPR into the buffer PTR of length LEN bytes.
7068 Return the number of bytes placed in the buffer, or zero
7072 native_encode_real (tree expr, unsigned char *ptr, int len)
7074 tree type = TREE_TYPE (expr);
7075 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7076 int byte, offset, word, words, bitpos;
7077 unsigned char value;
7079 /* There are always 32 bits in each long, no matter the size of
7080 the hosts long. We handle floating point representations with
7084 if (total_bytes > len)
7086 words = 32 / UNITS_PER_WORD;
7088 real_to_target (tmp, TREE_REAL_CST_PTR (expr), TYPE_MODE (type));
7090 for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7091 bitpos += BITS_PER_UNIT)
7093 byte = (bitpos / BITS_PER_UNIT) & 3;
7094 value = (unsigned char) (tmp[bitpos / 32] >> (bitpos & 31));
7096 if (UNITS_PER_WORD < 4)
7098 word = byte / UNITS_PER_WORD;
7099 if (WORDS_BIG_ENDIAN)
7100 word = (words - 1) - word;
7101 offset = word * UNITS_PER_WORD;
7102 if (BYTES_BIG_ENDIAN)
7103 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7105 offset += byte % UNITS_PER_WORD;
7108 offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
7109 ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)] = value;
7114 /* Subroutine of native_encode_expr. Encode the COMPLEX_CST
7115 specified by EXPR into the buffer PTR of length LEN bytes.
7116 Return the number of bytes placed in the buffer, or zero
7120 native_encode_complex (tree expr, unsigned char *ptr, int len)
7125 part = TREE_REALPART (expr);
7126 rsize = native_encode_expr (part, ptr, len);
7129 part = TREE_IMAGPART (expr);
7130 isize = native_encode_expr (part, ptr+rsize, len-rsize);
7133 return rsize + isize;
7137 /* Subroutine of native_encode_expr. Encode the VECTOR_CST
7138 specified by EXPR into the buffer PTR of length LEN bytes.
7139 Return the number of bytes placed in the buffer, or zero
7143 native_encode_vector (tree expr, unsigned char *ptr, int len)
7145 int i, size, offset, count;
7146 tree itype, elem, elements;
7149 elements = TREE_VECTOR_CST_ELTS (expr);
7150 count = TYPE_VECTOR_SUBPARTS (TREE_TYPE (expr));
7151 itype = TREE_TYPE (TREE_TYPE (expr));
7152 size = GET_MODE_SIZE (TYPE_MODE (itype));
7153 for (i = 0; i < count; i++)
7157 elem = TREE_VALUE (elements);
7158 elements = TREE_CHAIN (elements);
7165 if (native_encode_expr (elem, ptr+offset, len-offset) != size)
7170 if (offset + size > len)
7172 memset (ptr+offset, 0, size);
7180 /* Subroutine of fold_view_convert_expr. Encode the INTEGER_CST,
7181 REAL_CST, COMPLEX_CST or VECTOR_CST specified by EXPR into the
7182 buffer PTR of length LEN bytes. Return the number of bytes
7183 placed in the buffer, or zero upon failure. */
7186 native_encode_expr (tree expr, unsigned char *ptr, int len)
7188 switch (TREE_CODE (expr))
7191 return native_encode_int (expr, ptr, len);
7194 return native_encode_real (expr, ptr, len);
7197 return native_encode_complex (expr, ptr, len);
7200 return native_encode_vector (expr, ptr, len);
7208 /* Subroutine of native_interpret_expr. Interpret the contents of
7209 the buffer PTR of length LEN as an INTEGER_CST of type TYPE.
7210 If the buffer cannot be interpreted, return NULL_TREE. */
7213 native_interpret_int (tree type, unsigned char *ptr, int len)
7215 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7216 int byte, offset, word, words;
7217 unsigned char value;
7218 unsigned int HOST_WIDE_INT lo = 0;
7219 HOST_WIDE_INT hi = 0;
7221 if (total_bytes > len)
7223 if (total_bytes * BITS_PER_UNIT > 2 * HOST_BITS_PER_WIDE_INT)
7225 words = total_bytes / UNITS_PER_WORD;
7227 for (byte = 0; byte < total_bytes; byte++)
7229 int bitpos = byte * BITS_PER_UNIT;
7230 if (total_bytes > UNITS_PER_WORD)
7232 word = byte / UNITS_PER_WORD;
7233 if (WORDS_BIG_ENDIAN)
7234 word = (words - 1) - word;
7235 offset = word * UNITS_PER_WORD;
7236 if (BYTES_BIG_ENDIAN)
7237 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7239 offset += byte % UNITS_PER_WORD;
7242 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7243 value = ptr[offset];
7245 if (bitpos < HOST_BITS_PER_WIDE_INT)
7246 lo |= (unsigned HOST_WIDE_INT) value << bitpos;
7248 hi |= (unsigned HOST_WIDE_INT) value
7249 << (bitpos - HOST_BITS_PER_WIDE_INT);
7252 return force_fit_type (build_int_cst_wide (type, lo, hi),
7257 /* Subroutine of native_interpret_expr. Interpret the contents of
7258 the buffer PTR of length LEN as a REAL_CST of type TYPE.
7259 If the buffer cannot be interpreted, return NULL_TREE. */
7262 native_interpret_real (tree type, unsigned char *ptr, int len)
7264 enum machine_mode mode = TYPE_MODE (type);
7265 int total_bytes = GET_MODE_SIZE (mode);
7266 int byte, offset, word, words, bitpos;
7267 unsigned char value;
7268 /* There are always 32 bits in each long, no matter the size of
7269 the hosts long. We handle floating point representations with
7274 total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7275 if (total_bytes > len || total_bytes > 24)
7277 words = 32 / UNITS_PER_WORD;
7279 memset (tmp, 0, sizeof (tmp));
7280 for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7281 bitpos += BITS_PER_UNIT)
7283 byte = (bitpos / BITS_PER_UNIT) & 3;
7284 if (UNITS_PER_WORD < 4)
7286 word = byte / UNITS_PER_WORD;
7287 if (WORDS_BIG_ENDIAN)
7288 word = (words - 1) - word;
7289 offset = word * UNITS_PER_WORD;
7290 if (BYTES_BIG_ENDIAN)
7291 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7293 offset += byte % UNITS_PER_WORD;
7296 offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
7297 value = ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)];
7299 tmp[bitpos / 32] |= (unsigned long)value << (bitpos & 31);
7302 real_from_target (&r, tmp, mode);
7303 return build_real (type, r);
7307 /* Subroutine of native_interpret_expr. Interpret the contents of
7308 the buffer PTR of length LEN as a COMPLEX_CST of type TYPE.
7309 If the buffer cannot be interpreted, return NULL_TREE. */
7312 native_interpret_complex (tree type, unsigned char *ptr, int len)
7314 tree etype, rpart, ipart;
7317 etype = TREE_TYPE (type);
7318 size = GET_MODE_SIZE (TYPE_MODE (etype));
7321 rpart = native_interpret_expr (etype, ptr, size);
7324 ipart = native_interpret_expr (etype, ptr+size, size);
7327 return build_complex (type, rpart, ipart);
7331 /* Subroutine of native_interpret_expr. Interpret the contents of
7332 the buffer PTR of length LEN as a VECTOR_CST of type TYPE.
7333 If the buffer cannot be interpreted, return NULL_TREE. */
7336 native_interpret_vector (tree type, unsigned char *ptr, int len)
7338 tree etype, elem, elements;
7341 etype = TREE_TYPE (type);
7342 size = GET_MODE_SIZE (TYPE_MODE (etype));
7343 count = TYPE_VECTOR_SUBPARTS (type);
7344 if (size * count > len)
7347 elements = NULL_TREE;
7348 for (i = count - 1; i >= 0; i--)
7350 elem = native_interpret_expr (etype, ptr+(i*size), size);
7353 elements = tree_cons (NULL_TREE, elem, elements);
7355 return build_vector (type, elements);
7359 /* Subroutine of fold_view_convert_expr. Interpret the contents of
7360 the buffer PTR of length LEN as a constant of type TYPE. For
7361 INTEGRAL_TYPE_P we return an INTEGER_CST, for SCALAR_FLOAT_TYPE_P
7362 we return a REAL_CST, etc... If the buffer cannot be interpreted,
7363 return NULL_TREE. */
7366 native_interpret_expr (tree type, unsigned char *ptr, int len)
7368 switch (TREE_CODE (type))
7373 return native_interpret_int (type, ptr, len);
7376 return native_interpret_real (type, ptr, len);
7379 return native_interpret_complex (type, ptr, len);
7382 return native_interpret_vector (type, ptr, len);
7390 /* Fold a VIEW_CONVERT_EXPR of a constant expression EXPR to type
7391 TYPE at compile-time. If we're unable to perform the conversion
7392 return NULL_TREE. */
7395 fold_view_convert_expr (tree type, tree expr)
7397 /* We support up to 512-bit values (for V8DFmode). */
7398 unsigned char buffer[64];
7401 /* Check that the host and target are sane. */
7402 if (CHAR_BIT != 8 || BITS_PER_UNIT != 8)
7405 len = native_encode_expr (expr, buffer, sizeof (buffer));
7409 return native_interpret_expr (type, buffer, len);
7413 /* Fold a unary expression of code CODE and type TYPE with operand
7414 OP0. Return the folded expression if folding is successful.
7415 Otherwise, return NULL_TREE. */
7418 fold_unary (enum tree_code code, tree type, tree op0)
7422 enum tree_code_class kind = TREE_CODE_CLASS (code);
7424 gcc_assert (IS_EXPR_CODE_CLASS (kind)
7425 && TREE_CODE_LENGTH (code) == 1);
7430 if (code == NOP_EXPR || code == CONVERT_EXPR
7431 || code == FLOAT_EXPR || code == ABS_EXPR)
7433 /* Don't use STRIP_NOPS, because signedness of argument type
7435 STRIP_SIGN_NOPS (arg0);
7439 /* Strip any conversions that don't change the mode. This
7440 is safe for every expression, except for a comparison
7441 expression because its signedness is derived from its
7444 Note that this is done as an internal manipulation within
7445 the constant folder, in order to find the simplest
7446 representation of the arguments so that their form can be
7447 studied. In any cases, the appropriate type conversions
7448 should be put back in the tree that will get out of the
7454 if (TREE_CODE_CLASS (code) == tcc_unary)
7456 if (TREE_CODE (arg0) == COMPOUND_EXPR)
7457 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
7458 fold_build1 (code, type, TREE_OPERAND (arg0, 1)));
7459 else if (TREE_CODE (arg0) == COND_EXPR)
7461 tree arg01 = TREE_OPERAND (arg0, 1);
7462 tree arg02 = TREE_OPERAND (arg0, 2);
7463 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
7464 arg01 = fold_build1 (code, type, arg01);
7465 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
7466 arg02 = fold_build1 (code, type, arg02);
7467 tem = fold_build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
7470 /* If this was a conversion, and all we did was to move into
7471 inside the COND_EXPR, bring it back out. But leave it if
7472 it is a conversion from integer to integer and the
7473 result precision is no wider than a word since such a
7474 conversion is cheap and may be optimized away by combine,
7475 while it couldn't if it were outside the COND_EXPR. Then return
7476 so we don't get into an infinite recursion loop taking the
7477 conversion out and then back in. */
7479 if ((code == NOP_EXPR || code == CONVERT_EXPR
7480 || code == NON_LVALUE_EXPR)
7481 && TREE_CODE (tem) == COND_EXPR
7482 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
7483 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
7484 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
7485 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
7486 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
7487 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
7488 && (! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
7490 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
7491 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD)
7492 || flag_syntax_only))
7493 tem = build1 (code, type,
7495 TREE_TYPE (TREE_OPERAND
7496 (TREE_OPERAND (tem, 1), 0)),
7497 TREE_OPERAND (tem, 0),
7498 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
7499 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
7502 else if (COMPARISON_CLASS_P (arg0))
7504 if (TREE_CODE (type) == BOOLEAN_TYPE)
7506 arg0 = copy_node (arg0);
7507 TREE_TYPE (arg0) = type;
7510 else if (TREE_CODE (type) != INTEGER_TYPE)
7511 return fold_build3 (COND_EXPR, type, arg0,
7512 fold_build1 (code, type,
7514 fold_build1 (code, type,
7515 integer_zero_node));
7524 case FIX_TRUNC_EXPR:
7526 case FIX_FLOOR_EXPR:
7527 case FIX_ROUND_EXPR:
7528 if (TREE_TYPE (op0) == type)
7531 /* If we have (type) (a CMP b) and type is an integral type, return
7532 new expression involving the new type. */
7533 if (COMPARISON_CLASS_P (op0) && INTEGRAL_TYPE_P (type))
7534 return fold_build2 (TREE_CODE (op0), type, TREE_OPERAND (op0, 0),
7535 TREE_OPERAND (op0, 1));
7537 /* Handle cases of two conversions in a row. */
7538 if (TREE_CODE (op0) == NOP_EXPR
7539 || TREE_CODE (op0) == CONVERT_EXPR)
7541 tree inside_type = TREE_TYPE (TREE_OPERAND (op0, 0));
7542 tree inter_type = TREE_TYPE (op0);
7543 int inside_int = INTEGRAL_TYPE_P (inside_type);
7544 int inside_ptr = POINTER_TYPE_P (inside_type);
7545 int inside_float = FLOAT_TYPE_P (inside_type);
7546 int inside_vec = TREE_CODE (inside_type) == VECTOR_TYPE;
7547 unsigned int inside_prec = TYPE_PRECISION (inside_type);
7548 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
7549 int inter_int = INTEGRAL_TYPE_P (inter_type);
7550 int inter_ptr = POINTER_TYPE_P (inter_type);
7551 int inter_float = FLOAT_TYPE_P (inter_type);
7552 int inter_vec = TREE_CODE (inter_type) == VECTOR_TYPE;
7553 unsigned int inter_prec = TYPE_PRECISION (inter_type);
7554 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
7555 int final_int = INTEGRAL_TYPE_P (type);
7556 int final_ptr = POINTER_TYPE_P (type);
7557 int final_float = FLOAT_TYPE_P (type);
7558 int final_vec = TREE_CODE (type) == VECTOR_TYPE;
7559 unsigned int final_prec = TYPE_PRECISION (type);
7560 int final_unsignedp = TYPE_UNSIGNED (type);
7562 /* In addition to the cases of two conversions in a row
7563 handled below, if we are converting something to its own
7564 type via an object of identical or wider precision, neither
7565 conversion is needed. */
7566 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
7567 && (((inter_int || inter_ptr) && final_int)
7568 || (inter_float && final_float))
7569 && inter_prec >= final_prec)
7570 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7572 /* Likewise, if the intermediate and final types are either both
7573 float or both integer, we don't need the middle conversion if
7574 it is wider than the final type and doesn't change the signedness
7575 (for integers). Avoid this if the final type is a pointer
7576 since then we sometimes need the inner conversion. Likewise if
7577 the outer has a precision not equal to the size of its mode. */
7578 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
7579 || (inter_float && inside_float)
7580 || (inter_vec && inside_vec))
7581 && inter_prec >= inside_prec
7582 && (inter_float || inter_vec
7583 || inter_unsignedp == inside_unsignedp)
7584 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
7585 && TYPE_MODE (type) == TYPE_MODE (inter_type))
7587 && (! final_vec || inter_prec == inside_prec))
7588 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7590 /* If we have a sign-extension of a zero-extended value, we can
7591 replace that by a single zero-extension. */
7592 if (inside_int && inter_int && final_int
7593 && inside_prec < inter_prec && inter_prec < final_prec
7594 && inside_unsignedp && !inter_unsignedp)
7595 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7597 /* Two conversions in a row are not needed unless:
7598 - some conversion is floating-point (overstrict for now), or
7599 - some conversion is a vector (overstrict for now), or
7600 - the intermediate type is narrower than both initial and
7602 - the intermediate type and innermost type differ in signedness,
7603 and the outermost type is wider than the intermediate, or
7604 - the initial type is a pointer type and the precisions of the
7605 intermediate and final types differ, or
7606 - the final type is a pointer type and the precisions of the
7607 initial and intermediate types differ.
7608 - the final type is a pointer type and the initial type not
7609 - the initial type is a pointer to an array and the final type
7611 /* Java pointer type conversions generate checks in some
7612 cases, so we explicitly disallow this optimization. */
7613 if (! inside_float && ! inter_float && ! final_float
7614 && ! inside_vec && ! inter_vec && ! final_vec
7615 && (inter_prec >= inside_prec || inter_prec >= final_prec)
7616 && ! (inside_int && inter_int
7617 && inter_unsignedp != inside_unsignedp
7618 && inter_prec < final_prec)
7619 && ((inter_unsignedp && inter_prec > inside_prec)
7620 == (final_unsignedp && final_prec > inter_prec))
7621 && ! (inside_ptr && inter_prec != final_prec)
7622 && ! (final_ptr && inside_prec != inter_prec)
7623 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
7624 && TYPE_MODE (type) == TYPE_MODE (inter_type))
7625 && final_ptr == inside_ptr
7627 && TREE_CODE (TREE_TYPE (inside_type)) == ARRAY_TYPE
7628 && TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE)
7629 && ! ((strcmp (lang_hooks.name, "GNU Java") == 0)
7631 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7634 /* Handle (T *)&A.B.C for A being of type T and B and C
7635 living at offset zero. This occurs frequently in
7636 C++ upcasting and then accessing the base. */
7637 if (TREE_CODE (op0) == ADDR_EXPR
7638 && POINTER_TYPE_P (type)
7639 && handled_component_p (TREE_OPERAND (op0, 0)))
7641 HOST_WIDE_INT bitsize, bitpos;
7643 enum machine_mode mode;
7644 int unsignedp, volatilep;
7645 tree base = TREE_OPERAND (op0, 0);
7646 base = get_inner_reference (base, &bitsize, &bitpos, &offset,
7647 &mode, &unsignedp, &volatilep, false);
7648 /* If the reference was to a (constant) zero offset, we can use
7649 the address of the base if it has the same base type
7650 as the result type. */
7651 if (! offset && bitpos == 0
7652 && TYPE_MAIN_VARIANT (TREE_TYPE (type))
7653 == TYPE_MAIN_VARIANT (TREE_TYPE (base)))
7654 return fold_convert (type, build_fold_addr_expr (base));
7657 if (TREE_CODE (op0) == MODIFY_EXPR
7658 && TREE_CONSTANT (TREE_OPERAND (op0, 1))
7659 /* Detect assigning a bitfield. */
7660 && !(TREE_CODE (TREE_OPERAND (op0, 0)) == COMPONENT_REF
7661 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (op0, 0), 1))))
7663 /* Don't leave an assignment inside a conversion
7664 unless assigning a bitfield. */
7665 tem = fold_build1 (code, type, TREE_OPERAND (op0, 1));
7666 /* First do the assignment, then return converted constant. */
7667 tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), op0, tem);
7668 TREE_NO_WARNING (tem) = 1;
7669 TREE_USED (tem) = 1;
7673 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
7674 constants (if x has signed type, the sign bit cannot be set
7675 in c). This folds extension into the BIT_AND_EXPR. */
7676 if (INTEGRAL_TYPE_P (type)
7677 && TREE_CODE (type) != BOOLEAN_TYPE
7678 && TREE_CODE (op0) == BIT_AND_EXPR
7679 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
7682 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
7685 if (TYPE_UNSIGNED (TREE_TYPE (and))
7686 || (TYPE_PRECISION (type)
7687 <= TYPE_PRECISION (TREE_TYPE (and))))
7689 else if (TYPE_PRECISION (TREE_TYPE (and1))
7690 <= HOST_BITS_PER_WIDE_INT
7691 && host_integerp (and1, 1))
7693 unsigned HOST_WIDE_INT cst;
7695 cst = tree_low_cst (and1, 1);
7696 cst &= (HOST_WIDE_INT) -1
7697 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
7698 change = (cst == 0);
7699 #ifdef LOAD_EXTEND_OP
7701 && !flag_syntax_only
7702 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
7705 tree uns = lang_hooks.types.unsigned_type (TREE_TYPE (and0));
7706 and0 = fold_convert (uns, and0);
7707 and1 = fold_convert (uns, and1);
7713 tem = build_int_cst_wide (type, TREE_INT_CST_LOW (and1),
7714 TREE_INT_CST_HIGH (and1));
7715 tem = force_fit_type (tem, 0, TREE_OVERFLOW (and1),
7716 TREE_CONSTANT_OVERFLOW (and1));
7717 return fold_build2 (BIT_AND_EXPR, type,
7718 fold_convert (type, and0), tem);
7722 /* Convert (T1)((T2)X op Y) into (T1)X op Y, for pointer types T1 and
7723 T2 being pointers to types of the same size. */
7724 if (POINTER_TYPE_P (type)
7725 && BINARY_CLASS_P (arg0)
7726 && TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
7727 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0))))
7729 tree arg00 = TREE_OPERAND (arg0, 0);
7731 tree t1 = TREE_TYPE (arg00);
7732 tree tt0 = TREE_TYPE (t0);
7733 tree tt1 = TREE_TYPE (t1);
7734 tree s0 = TYPE_SIZE (tt0);
7735 tree s1 = TYPE_SIZE (tt1);
7737 if (s0 && s1 && operand_equal_p (s0, s1, OEP_ONLY_CONST))
7738 return build2 (TREE_CODE (arg0), t0, fold_convert (t0, arg00),
7739 TREE_OPERAND (arg0, 1));
7742 /* Convert (T1)(~(T2)X) into ~(T1)X if T1 and T2 are integral types
7743 of the same precision, and X is a integer type not narrower than
7744 types T1 or T2, i.e. the cast (T2)X isn't an extension. */
7745 if (INTEGRAL_TYPE_P (type)
7746 && TREE_CODE (op0) == BIT_NOT_EXPR
7747 && INTEGRAL_TYPE_P (TREE_TYPE (op0))
7748 && (TREE_CODE (TREE_OPERAND (op0, 0)) == NOP_EXPR
7749 || TREE_CODE (TREE_OPERAND (op0, 0)) == CONVERT_EXPR)
7750 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0)))
7752 tem = TREE_OPERAND (TREE_OPERAND (op0, 0), 0);
7753 if (INTEGRAL_TYPE_P (TREE_TYPE (tem))
7754 && TYPE_PRECISION (type) <= TYPE_PRECISION (TREE_TYPE (tem)))
7755 return fold_build1 (BIT_NOT_EXPR, type, fold_convert (type, tem));
7758 tem = fold_convert_const (code, type, op0);
7759 return tem ? tem : NULL_TREE;
7761 case VIEW_CONVERT_EXPR:
7762 if (TREE_CODE (op0) == VIEW_CONVERT_EXPR)
7763 return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
7764 return fold_view_convert_expr (type, op0);
7767 tem = fold_negate_expr (arg0);
7769 return fold_convert (type, tem);
7773 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
7774 return fold_abs_const (arg0, type);
7775 else if (TREE_CODE (arg0) == NEGATE_EXPR)
7776 return fold_build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
7777 /* Convert fabs((double)float) into (double)fabsf(float). */
7778 else if (TREE_CODE (arg0) == NOP_EXPR
7779 && TREE_CODE (type) == REAL_TYPE)
7781 tree targ0 = strip_float_extensions (arg0);
7783 return fold_convert (type, fold_build1 (ABS_EXPR,
7787 /* ABS_EXPR<ABS_EXPR<x>> = ABS_EXPR<x> even if flag_wrapv is on. */
7788 else if (TREE_CODE (arg0) == ABS_EXPR)
7790 else if (tree_expr_nonnegative_p (arg0))
7793 /* Strip sign ops from argument. */
7794 if (TREE_CODE (type) == REAL_TYPE)
7796 tem = fold_strip_sign_ops (arg0);
7798 return fold_build1 (ABS_EXPR, type, fold_convert (type, tem));
7803 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7804 return fold_convert (type, arg0);
7805 if (TREE_CODE (arg0) == COMPLEX_EXPR)
7807 tree itype = TREE_TYPE (type);
7808 tree rpart = fold_convert (itype, TREE_OPERAND (arg0, 0));
7809 tree ipart = fold_convert (itype, TREE_OPERAND (arg0, 1));
7810 return fold_build2 (COMPLEX_EXPR, type, rpart, negate_expr (ipart));
7812 if (TREE_CODE (arg0) == COMPLEX_CST)
7814 tree itype = TREE_TYPE (type);
7815 tree rpart = fold_convert (itype, TREE_REALPART (arg0));
7816 tree ipart = fold_convert (itype, TREE_IMAGPART (arg0));
7817 return build_complex (type, rpart, negate_expr (ipart));
7819 if (TREE_CODE (arg0) == CONJ_EXPR)
7820 return fold_convert (type, TREE_OPERAND (arg0, 0));
7824 if (TREE_CODE (arg0) == INTEGER_CST)
7825 return fold_not_const (arg0, type);
7826 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
7827 return TREE_OPERAND (arg0, 0);
7828 /* Convert ~ (-A) to A - 1. */
7829 else if (INTEGRAL_TYPE_P (type) && TREE_CODE (arg0) == NEGATE_EXPR)
7830 return fold_build2 (MINUS_EXPR, type, TREE_OPERAND (arg0, 0),
7831 build_int_cst (type, 1));
7832 /* Convert ~ (A - 1) or ~ (A + -1) to -A. */
7833 else if (INTEGRAL_TYPE_P (type)
7834 && ((TREE_CODE (arg0) == MINUS_EXPR
7835 && integer_onep (TREE_OPERAND (arg0, 1)))
7836 || (TREE_CODE (arg0) == PLUS_EXPR
7837 && integer_all_onesp (TREE_OPERAND (arg0, 1)))))
7838 return fold_build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0));
7839 /* Convert ~(X ^ Y) to ~X ^ Y or X ^ ~Y if ~X or ~Y simplify. */
7840 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
7841 && (tem = fold_unary (BIT_NOT_EXPR, type,
7843 TREE_OPERAND (arg0, 0)))))
7844 return fold_build2 (BIT_XOR_EXPR, type, tem,
7845 fold_convert (type, TREE_OPERAND (arg0, 1)));
7846 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
7847 && (tem = fold_unary (BIT_NOT_EXPR, type,
7849 TREE_OPERAND (arg0, 1)))))
7850 return fold_build2 (BIT_XOR_EXPR, type,
7851 fold_convert (type, TREE_OPERAND (arg0, 0)), tem);
7855 case TRUTH_NOT_EXPR:
7856 /* The argument to invert_truthvalue must have Boolean type. */
7857 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
7858 arg0 = fold_convert (boolean_type_node, arg0);
7860 /* Note that the operand of this must be an int
7861 and its values must be 0 or 1.
7862 ("true" is a fixed value perhaps depending on the language,
7863 but we don't handle values other than 1 correctly yet.) */
7864 tem = fold_truth_not_expr (arg0);
7867 return fold_convert (type, tem);
7870 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7871 return fold_convert (type, arg0);
7872 if (TREE_CODE (arg0) == COMPLEX_EXPR)
7873 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
7874 TREE_OPERAND (arg0, 1));
7875 if (TREE_CODE (arg0) == COMPLEX_CST)
7876 return fold_convert (type, TREE_REALPART (arg0));
7877 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7879 tree itype = TREE_TYPE (TREE_TYPE (arg0));
7880 tem = fold_build2 (TREE_CODE (arg0), itype,
7881 fold_build1 (REALPART_EXPR, itype,
7882 TREE_OPERAND (arg0, 0)),
7883 fold_build1 (REALPART_EXPR, itype,
7884 TREE_OPERAND (arg0, 1)));
7885 return fold_convert (type, tem);
7887 if (TREE_CODE (arg0) == CONJ_EXPR)
7889 tree itype = TREE_TYPE (TREE_TYPE (arg0));
7890 tem = fold_build1 (REALPART_EXPR, itype, TREE_OPERAND (arg0, 0));
7891 return fold_convert (type, tem);
7896 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7897 return fold_convert (type, integer_zero_node);
7898 if (TREE_CODE (arg0) == COMPLEX_EXPR)
7899 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
7900 TREE_OPERAND (arg0, 0));
7901 if (TREE_CODE (arg0) == COMPLEX_CST)
7902 return fold_convert (type, TREE_IMAGPART (arg0));
7903 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7905 tree itype = TREE_TYPE (TREE_TYPE (arg0));
7906 tem = fold_build2 (TREE_CODE (arg0), itype,
7907 fold_build1 (IMAGPART_EXPR, itype,
7908 TREE_OPERAND (arg0, 0)),
7909 fold_build1 (IMAGPART_EXPR, itype,
7910 TREE_OPERAND (arg0, 1)));
7911 return fold_convert (type, tem);
7913 if (TREE_CODE (arg0) == CONJ_EXPR)
7915 tree itype = TREE_TYPE (TREE_TYPE (arg0));
7916 tem = fold_build1 (IMAGPART_EXPR, itype, TREE_OPERAND (arg0, 0));
7917 return fold_convert (type, negate_expr (tem));
7923 } /* switch (code) */
7926 /* Fold a binary expression of code CODE and type TYPE with operands
7927 OP0 and OP1, containing either a MIN-MAX or a MAX-MIN combination.
7928 Return the folded expression if folding is successful. Otherwise,
7929 return NULL_TREE. */
7932 fold_minmax (enum tree_code code, tree type, tree op0, tree op1)
7934 enum tree_code compl_code;
7936 if (code == MIN_EXPR)
7937 compl_code = MAX_EXPR;
7938 else if (code == MAX_EXPR)
7939 compl_code = MIN_EXPR;
7943 /* MIN (MAX (a, b), b) == b. */
7944 if (TREE_CODE (op0) == compl_code
7945 && operand_equal_p (TREE_OPERAND (op0, 1), op1, 0))
7946 return omit_one_operand (type, op1, TREE_OPERAND (op0, 0));
7948 /* MIN (MAX (b, a), b) == b. */
7949 if (TREE_CODE (op0) == compl_code
7950 && operand_equal_p (TREE_OPERAND (op0, 0), op1, 0)
7951 && reorder_operands_p (TREE_OPERAND (op0, 1), op1))
7952 return omit_one_operand (type, op1, TREE_OPERAND (op0, 1));
7954 /* MIN (a, MAX (a, b)) == a. */
7955 if (TREE_CODE (op1) == compl_code
7956 && operand_equal_p (op0, TREE_OPERAND (op1, 0), 0)
7957 && reorder_operands_p (op0, TREE_OPERAND (op1, 1)))
7958 return omit_one_operand (type, op0, TREE_OPERAND (op1, 1));
7960 /* MIN (a, MAX (b, a)) == a. */
7961 if (TREE_CODE (op1) == compl_code
7962 && operand_equal_p (op0, TREE_OPERAND (op1, 1), 0)
7963 && reorder_operands_p (op0, TREE_OPERAND (op1, 0)))
7964 return omit_one_operand (type, op0, TREE_OPERAND (op1, 0));
7969 /* Subroutine of fold_binary. This routine performs all of the
7970 transformations that are common to the equality/inequality
7971 operators (EQ_EXPR and NE_EXPR) and the ordering operators
7972 (LT_EXPR, LE_EXPR, GE_EXPR and GT_EXPR). Callers other than
7973 fold_binary should call fold_binary. Fold a comparison with
7974 tree code CODE and type TYPE with operands OP0 and OP1. Return
7975 the folded comparison or NULL_TREE. */
7978 fold_comparison (enum tree_code code, tree type, tree op0, tree op1)
7980 tree arg0, arg1, tem;
7985 STRIP_SIGN_NOPS (arg0);
7986 STRIP_SIGN_NOPS (arg1);
7988 tem = fold_relational_const (code, type, arg0, arg1);
7989 if (tem != NULL_TREE)
7992 /* If one arg is a real or integer constant, put it last. */
7993 if (tree_swap_operands_p (arg0, arg1, true))
7994 return fold_build2 (swap_tree_comparison (code), type, op1, op0);
7996 /* Transform comparisons of the form X +- C1 CMP C2 to X CMP C2 +- C1. */
7997 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7998 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7999 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
8000 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
8001 && (TREE_CODE (arg1) == INTEGER_CST
8002 && !TREE_OVERFLOW (arg1)))
8004 tree const1 = TREE_OPERAND (arg0, 1);
8006 tree variable = TREE_OPERAND (arg0, 0);
8009 lhs_add = TREE_CODE (arg0) != PLUS_EXPR;
8011 lhs = fold_build2 (lhs_add ? PLUS_EXPR : MINUS_EXPR,
8012 TREE_TYPE (arg1), const2, const1);
8013 if (TREE_CODE (lhs) == TREE_CODE (arg1)
8014 && (TREE_CODE (lhs) != INTEGER_CST
8015 || !TREE_OVERFLOW (lhs)))
8017 fold_overflow_warning (("assuming signed overflow does not occur "
8018 "when changing X +- C1 cmp C2 to "
8020 WARN_STRICT_OVERFLOW_COMPARISON);
8021 return fold_build2 (code, type, variable, lhs);
8025 /* If this is a comparison of two exprs that look like an ARRAY_REF of the
8026 same object, then we can fold this to a comparison of the two offsets in
8027 signed size type. This is possible because pointer arithmetic is
8028 restricted to retain within an object and overflow on pointer differences
8029 is undefined as of 6.5.6/8 and /9 with respect to the signed ptrdiff_t.
8031 We check flag_wrapv directly because pointers types are unsigned,
8032 and therefore TYPE_OVERFLOW_WRAPS returns true for them. That is
8033 normally what we want to avoid certain odd overflow cases, but
8035 if (POINTER_TYPE_P (TREE_TYPE (arg0))
8037 && !TYPE_OVERFLOW_TRAPS (TREE_TYPE (arg0)))
8039 tree base0, offset0, base1, offset1;
8041 if (extract_array_ref (arg0, &base0, &offset0)
8042 && extract_array_ref (arg1, &base1, &offset1)
8043 && operand_equal_p (base0, base1, 0))
8045 tree signed_size_type_node;
8046 signed_size_type_node = signed_type_for (size_type_node);
8048 /* By converting to signed size type we cover middle-end pointer
8049 arithmetic which operates on unsigned pointer types of size
8050 type size and ARRAY_REF offsets which are properly sign or
8051 zero extended from their type in case it is narrower than
8053 if (offset0 == NULL_TREE)
8054 offset0 = build_int_cst (signed_size_type_node, 0);
8056 offset0 = fold_convert (signed_size_type_node, offset0);
8057 if (offset1 == NULL_TREE)
8058 offset1 = build_int_cst (signed_size_type_node, 0);
8060 offset1 = fold_convert (signed_size_type_node, offset1);
8062 return fold_build2 (code, type, offset0, offset1);
8066 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
8068 tree targ0 = strip_float_extensions (arg0);
8069 tree targ1 = strip_float_extensions (arg1);
8070 tree newtype = TREE_TYPE (targ0);
8072 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
8073 newtype = TREE_TYPE (targ1);
8075 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
8076 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
8077 return fold_build2 (code, type, fold_convert (newtype, targ0),
8078 fold_convert (newtype, targ1));
8080 /* (-a) CMP (-b) -> b CMP a */
8081 if (TREE_CODE (arg0) == NEGATE_EXPR
8082 && TREE_CODE (arg1) == NEGATE_EXPR)
8083 return fold_build2 (code, type, TREE_OPERAND (arg1, 0),
8084 TREE_OPERAND (arg0, 0));
8086 if (TREE_CODE (arg1) == REAL_CST)
8088 REAL_VALUE_TYPE cst;
8089 cst = TREE_REAL_CST (arg1);
8091 /* (-a) CMP CST -> a swap(CMP) (-CST) */
8092 if (TREE_CODE (arg0) == NEGATE_EXPR)
8093 return fold_build2 (swap_tree_comparison (code), type,
8094 TREE_OPERAND (arg0, 0),
8095 build_real (TREE_TYPE (arg1),
8096 REAL_VALUE_NEGATE (cst)));
8098 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
8099 /* a CMP (-0) -> a CMP 0 */
8100 if (REAL_VALUE_MINUS_ZERO (cst))
8101 return fold_build2 (code, type, arg0,
8102 build_real (TREE_TYPE (arg1), dconst0));
8104 /* x != NaN is always true, other ops are always false. */
8105 if (REAL_VALUE_ISNAN (cst)
8106 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
8108 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
8109 return omit_one_operand (type, tem, arg0);
8112 /* Fold comparisons against infinity. */
8113 if (REAL_VALUE_ISINF (cst))
8115 tem = fold_inf_compare (code, type, arg0, arg1);
8116 if (tem != NULL_TREE)
8121 /* If this is a comparison of a real constant with a PLUS_EXPR
8122 or a MINUS_EXPR of a real constant, we can convert it into a
8123 comparison with a revised real constant as long as no overflow
8124 occurs when unsafe_math_optimizations are enabled. */
8125 if (flag_unsafe_math_optimizations
8126 && TREE_CODE (arg1) == REAL_CST
8127 && (TREE_CODE (arg0) == PLUS_EXPR
8128 || TREE_CODE (arg0) == MINUS_EXPR)
8129 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
8130 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
8131 ? MINUS_EXPR : PLUS_EXPR,
8132 arg1, TREE_OPERAND (arg0, 1), 0))
8133 && ! TREE_CONSTANT_OVERFLOW (tem))
8134 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
8136 /* Likewise, we can simplify a comparison of a real constant with
8137 a MINUS_EXPR whose first operand is also a real constant, i.e.
8138 (c1 - x) < c2 becomes x > c1-c2. */
8139 if (flag_unsafe_math_optimizations
8140 && TREE_CODE (arg1) == REAL_CST
8141 && TREE_CODE (arg0) == MINUS_EXPR
8142 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
8143 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
8145 && ! TREE_CONSTANT_OVERFLOW (tem))
8146 return fold_build2 (swap_tree_comparison (code), type,
8147 TREE_OPERAND (arg0, 1), tem);
8149 /* Fold comparisons against built-in math functions. */
8150 if (TREE_CODE (arg1) == REAL_CST
8151 && flag_unsafe_math_optimizations
8152 && ! flag_errno_math)
8154 enum built_in_function fcode = builtin_mathfn_code (arg0);
8156 if (fcode != END_BUILTINS)
8158 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
8159 if (tem != NULL_TREE)
8165 /* Convert foo++ == CONST into ++foo == CONST + INCR. */
8166 if (TREE_CONSTANT (arg1)
8167 && (TREE_CODE (arg0) == POSTINCREMENT_EXPR
8168 || TREE_CODE (arg0) == POSTDECREMENT_EXPR)
8169 /* This optimization is invalid for ordered comparisons
8170 if CONST+INCR overflows or if foo+incr might overflow.
8171 This optimization is invalid for floating point due to rounding.
8172 For pointer types we assume overflow doesn't happen. */
8173 && (POINTER_TYPE_P (TREE_TYPE (arg0))
8174 || (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
8175 && (code == EQ_EXPR || code == NE_EXPR))))
8177 tree varop, newconst;
8179 if (TREE_CODE (arg0) == POSTINCREMENT_EXPR)
8181 newconst = fold_build2 (PLUS_EXPR, TREE_TYPE (arg0),
8182 arg1, TREE_OPERAND (arg0, 1));
8183 varop = build2 (PREINCREMENT_EXPR, TREE_TYPE (arg0),
8184 TREE_OPERAND (arg0, 0),
8185 TREE_OPERAND (arg0, 1));
8189 newconst = fold_build2 (MINUS_EXPR, TREE_TYPE (arg0),
8190 arg1, TREE_OPERAND (arg0, 1));
8191 varop = build2 (PREDECREMENT_EXPR, TREE_TYPE (arg0),
8192 TREE_OPERAND (arg0, 0),
8193 TREE_OPERAND (arg0, 1));
8197 /* If VAROP is a reference to a bitfield, we must mask
8198 the constant by the width of the field. */
8199 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
8200 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (varop, 0), 1))
8201 && host_integerp (DECL_SIZE (TREE_OPERAND
8202 (TREE_OPERAND (varop, 0), 1)), 1))
8204 tree fielddecl = TREE_OPERAND (TREE_OPERAND (varop, 0), 1);
8205 HOST_WIDE_INT size = tree_low_cst (DECL_SIZE (fielddecl), 1);
8206 tree folded_compare, shift;
8208 /* First check whether the comparison would come out
8209 always the same. If we don't do that we would
8210 change the meaning with the masking. */
8211 folded_compare = fold_build2 (code, type,
8212 TREE_OPERAND (varop, 0), arg1);
8213 if (TREE_CODE (folded_compare) == INTEGER_CST)
8214 return omit_one_operand (type, folded_compare, varop);
8216 shift = build_int_cst (NULL_TREE,
8217 TYPE_PRECISION (TREE_TYPE (varop)) - size);
8218 shift = fold_convert (TREE_TYPE (varop), shift);
8219 newconst = fold_build2 (LSHIFT_EXPR, TREE_TYPE (varop),
8221 newconst = fold_build2 (RSHIFT_EXPR, TREE_TYPE (varop),
8225 return fold_build2 (code, type, varop, newconst);
8228 if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
8229 && (TREE_CODE (arg0) == NOP_EXPR
8230 || TREE_CODE (arg0) == CONVERT_EXPR))
8232 /* If we are widening one operand of an integer comparison,
8233 see if the other operand is similarly being widened. Perhaps we
8234 can do the comparison in the narrower type. */
8235 tem = fold_widened_comparison (code, type, arg0, arg1);
8239 /* Or if we are changing signedness. */
8240 tem = fold_sign_changed_comparison (code, type, arg0, arg1);
8245 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
8246 constant, we can simplify it. */
8247 if (TREE_CODE (arg1) == INTEGER_CST
8248 && (TREE_CODE (arg0) == MIN_EXPR
8249 || TREE_CODE (arg0) == MAX_EXPR)
8250 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8252 tem = optimize_minmax_comparison (code, type, op0, op1);
8257 /* Simplify comparison of something with itself. (For IEEE
8258 floating-point, we can only do some of these simplifications.) */
8259 if (operand_equal_p (arg0, arg1, 0))
8264 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8265 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8266 return constant_boolean_node (1, type);
8271 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8272 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8273 return constant_boolean_node (1, type);
8274 return fold_build2 (EQ_EXPR, type, arg0, arg1);
8277 /* For NE, we can only do this simplification if integer
8278 or we don't honor IEEE floating point NaNs. */
8279 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
8280 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8282 /* ... fall through ... */
8285 return constant_boolean_node (0, type);
8291 /* If we are comparing an expression that just has comparisons
8292 of two integer values, arithmetic expressions of those comparisons,
8293 and constants, we can simplify it. There are only three cases
8294 to check: the two values can either be equal, the first can be
8295 greater, or the second can be greater. Fold the expression for
8296 those three values. Since each value must be 0 or 1, we have
8297 eight possibilities, each of which corresponds to the constant 0
8298 or 1 or one of the six possible comparisons.
8300 This handles common cases like (a > b) == 0 but also handles
8301 expressions like ((x > y) - (y > x)) > 0, which supposedly
8302 occur in macroized code. */
8304 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
8306 tree cval1 = 0, cval2 = 0;
8309 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
8310 /* Don't handle degenerate cases here; they should already
8311 have been handled anyway. */
8312 && cval1 != 0 && cval2 != 0
8313 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
8314 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
8315 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
8316 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
8317 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
8318 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
8319 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
8321 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
8322 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
8324 /* We can't just pass T to eval_subst in case cval1 or cval2
8325 was the same as ARG1. */
8328 = fold_build2 (code, type,
8329 eval_subst (arg0, cval1, maxval,
8333 = fold_build2 (code, type,
8334 eval_subst (arg0, cval1, maxval,
8338 = fold_build2 (code, type,
8339 eval_subst (arg0, cval1, minval,
8343 /* All three of these results should be 0 or 1. Confirm they are.
8344 Then use those values to select the proper code to use. */
8346 if (TREE_CODE (high_result) == INTEGER_CST
8347 && TREE_CODE (equal_result) == INTEGER_CST
8348 && TREE_CODE (low_result) == INTEGER_CST)
8350 /* Make a 3-bit mask with the high-order bit being the
8351 value for `>', the next for '=', and the low for '<'. */
8352 switch ((integer_onep (high_result) * 4)
8353 + (integer_onep (equal_result) * 2)
8354 + integer_onep (low_result))
8358 return omit_one_operand (type, integer_zero_node, arg0);
8379 return omit_one_operand (type, integer_one_node, arg0);
8383 return save_expr (build2 (code, type, cval1, cval2));
8384 return fold_build2 (code, type, cval1, cval2);
8389 /* Fold a comparison of the address of COMPONENT_REFs with the same
8390 type and component to a comparison of the address of the base
8391 object. In short, &x->a OP &y->a to x OP y and
8392 &x->a OP &y.a to x OP &y */
8393 if (TREE_CODE (arg0) == ADDR_EXPR
8394 && TREE_CODE (TREE_OPERAND (arg0, 0)) == COMPONENT_REF
8395 && TREE_CODE (arg1) == ADDR_EXPR
8396 && TREE_CODE (TREE_OPERAND (arg1, 0)) == COMPONENT_REF)
8398 tree cref0 = TREE_OPERAND (arg0, 0);
8399 tree cref1 = TREE_OPERAND (arg1, 0);
8400 if (TREE_OPERAND (cref0, 1) == TREE_OPERAND (cref1, 1))
8402 tree op0 = TREE_OPERAND (cref0, 0);
8403 tree op1 = TREE_OPERAND (cref1, 0);
8404 return fold_build2 (code, type,
8405 build_fold_addr_expr (op0),
8406 build_fold_addr_expr (op1));
8410 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
8411 into a single range test. */
8412 if ((TREE_CODE (arg0) == TRUNC_DIV_EXPR
8413 || TREE_CODE (arg0) == EXACT_DIV_EXPR)
8414 && TREE_CODE (arg1) == INTEGER_CST
8415 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8416 && !integer_zerop (TREE_OPERAND (arg0, 1))
8417 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
8418 && !TREE_OVERFLOW (arg1))
8420 tem = fold_div_compare (code, type, arg0, arg1);
8421 if (tem != NULL_TREE)
8429 /* Subroutine of fold_binary. Optimize complex multiplications of the
8430 form z * conj(z), as pow(realpart(z),2) + pow(imagpart(z),2). The
8431 argument EXPR represents the expression "z" of type TYPE. */
8434 fold_mult_zconjz (tree type, tree expr)
8436 tree itype = TREE_TYPE (type);
8437 tree rpart, ipart, tem;
8439 if (TREE_CODE (expr) == COMPLEX_EXPR)
8441 rpart = TREE_OPERAND (expr, 0);
8442 ipart = TREE_OPERAND (expr, 1);
8444 else if (TREE_CODE (expr) == COMPLEX_CST)
8446 rpart = TREE_REALPART (expr);
8447 ipart = TREE_IMAGPART (expr);
8451 expr = save_expr (expr);
8452 rpart = fold_build1 (REALPART_EXPR, itype, expr);
8453 ipart = fold_build1 (IMAGPART_EXPR, itype, expr);
8456 rpart = save_expr (rpart);
8457 ipart = save_expr (ipart);
8458 tem = fold_build2 (PLUS_EXPR, itype,
8459 fold_build2 (MULT_EXPR, itype, rpart, rpart),
8460 fold_build2 (MULT_EXPR, itype, ipart, ipart));
8461 return fold_build2 (COMPLEX_EXPR, type, tem,
8462 fold_convert (itype, integer_zero_node));
8466 /* Fold a binary expression of code CODE and type TYPE with operands
8467 OP0 and OP1. Return the folded expression if folding is
8468 successful. Otherwise, return NULL_TREE. */
8471 fold_binary (enum tree_code code, tree type, tree op0, tree op1)
8473 enum tree_code_class kind = TREE_CODE_CLASS (code);
8474 tree arg0, arg1, tem;
8475 tree t1 = NULL_TREE;
8476 bool strict_overflow_p;
8478 gcc_assert (IS_EXPR_CODE_CLASS (kind)
8479 && TREE_CODE_LENGTH (code) == 2
8481 && op1 != NULL_TREE);
8486 /* Strip any conversions that don't change the mode. This is
8487 safe for every expression, except for a comparison expression
8488 because its signedness is derived from its operands. So, in
8489 the latter case, only strip conversions that don't change the
8492 Note that this is done as an internal manipulation within the
8493 constant folder, in order to find the simplest representation
8494 of the arguments so that their form can be studied. In any
8495 cases, the appropriate type conversions should be put back in
8496 the tree that will get out of the constant folder. */
8498 if (kind == tcc_comparison)
8500 STRIP_SIGN_NOPS (arg0);
8501 STRIP_SIGN_NOPS (arg1);
8509 /* Note that TREE_CONSTANT isn't enough: static var addresses are
8510 constant but we can't do arithmetic on them. */
8511 if ((TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
8512 || (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
8513 || (TREE_CODE (arg0) == COMPLEX_CST && TREE_CODE (arg1) == COMPLEX_CST)
8514 || (TREE_CODE (arg0) == VECTOR_CST && TREE_CODE (arg1) == VECTOR_CST))
8516 if (kind == tcc_binary)
8517 tem = const_binop (code, arg0, arg1, 0);
8518 else if (kind == tcc_comparison)
8519 tem = fold_relational_const (code, type, arg0, arg1);
8523 if (tem != NULL_TREE)
8525 if (TREE_TYPE (tem) != type)
8526 tem = fold_convert (type, tem);
8531 /* If this is a commutative operation, and ARG0 is a constant, move it
8532 to ARG1 to reduce the number of tests below. */
8533 if (commutative_tree_code (code)
8534 && tree_swap_operands_p (arg0, arg1, true))
8535 return fold_build2 (code, type, op1, op0);
8537 /* ARG0 is the first operand of EXPR, and ARG1 is the second operand.
8539 First check for cases where an arithmetic operation is applied to a
8540 compound, conditional, or comparison operation. Push the arithmetic
8541 operation inside the compound or conditional to see if any folding
8542 can then be done. Convert comparison to conditional for this purpose.
8543 The also optimizes non-constant cases that used to be done in
8546 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
8547 one of the operands is a comparison and the other is a comparison, a
8548 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
8549 code below would make the expression more complex. Change it to a
8550 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
8551 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
8553 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
8554 || code == EQ_EXPR || code == NE_EXPR)
8555 && ((truth_value_p (TREE_CODE (arg0))
8556 && (truth_value_p (TREE_CODE (arg1))
8557 || (TREE_CODE (arg1) == BIT_AND_EXPR
8558 && integer_onep (TREE_OPERAND (arg1, 1)))))
8559 || (truth_value_p (TREE_CODE (arg1))
8560 && (truth_value_p (TREE_CODE (arg0))
8561 || (TREE_CODE (arg0) == BIT_AND_EXPR
8562 && integer_onep (TREE_OPERAND (arg0, 1)))))))
8564 tem = fold_build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
8565 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
8568 fold_convert (boolean_type_node, arg0),
8569 fold_convert (boolean_type_node, arg1));
8571 if (code == EQ_EXPR)
8572 tem = invert_truthvalue (tem);
8574 return fold_convert (type, tem);
8577 if (TREE_CODE_CLASS (code) == tcc_binary
8578 || TREE_CODE_CLASS (code) == tcc_comparison)
8580 if (TREE_CODE (arg0) == COMPOUND_EXPR)
8581 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
8582 fold_build2 (code, type,
8583 TREE_OPERAND (arg0, 1), op1));
8584 if (TREE_CODE (arg1) == COMPOUND_EXPR
8585 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
8586 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
8587 fold_build2 (code, type,
8588 op0, TREE_OPERAND (arg1, 1)));
8590 if (TREE_CODE (arg0) == COND_EXPR || COMPARISON_CLASS_P (arg0))
8592 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
8594 /*cond_first_p=*/1);
8595 if (tem != NULL_TREE)
8599 if (TREE_CODE (arg1) == COND_EXPR || COMPARISON_CLASS_P (arg1))
8601 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
8603 /*cond_first_p=*/0);
8604 if (tem != NULL_TREE)
8612 /* A + (-B) -> A - B */
8613 if (TREE_CODE (arg1) == NEGATE_EXPR)
8614 return fold_build2 (MINUS_EXPR, type,
8615 fold_convert (type, arg0),
8616 fold_convert (type, TREE_OPERAND (arg1, 0)));
8617 /* (-A) + B -> B - A */
8618 if (TREE_CODE (arg0) == NEGATE_EXPR
8619 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
8620 return fold_build2 (MINUS_EXPR, type,
8621 fold_convert (type, arg1),
8622 fold_convert (type, TREE_OPERAND (arg0, 0)));
8623 /* Convert ~A + 1 to -A. */
8624 if (INTEGRAL_TYPE_P (type)
8625 && TREE_CODE (arg0) == BIT_NOT_EXPR
8626 && integer_onep (arg1))
8627 return fold_build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0));
8629 /* Handle (A1 * C1) + (A2 * C2) with A1, A2 or C1, C2 being the
8631 if ((TREE_CODE (arg0) == MULT_EXPR
8632 || TREE_CODE (arg1) == MULT_EXPR)
8633 && (!FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
8635 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
8640 if (! FLOAT_TYPE_P (type))
8642 if (integer_zerop (arg1))
8643 return non_lvalue (fold_convert (type, arg0));
8645 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
8646 with a constant, and the two constants have no bits in common,
8647 we should treat this as a BIT_IOR_EXPR since this may produce more
8649 if (TREE_CODE (arg0) == BIT_AND_EXPR
8650 && TREE_CODE (arg1) == BIT_AND_EXPR
8651 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8652 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
8653 && integer_zerop (const_binop (BIT_AND_EXPR,
8654 TREE_OPERAND (arg0, 1),
8655 TREE_OPERAND (arg1, 1), 0)))
8657 code = BIT_IOR_EXPR;
8661 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
8662 (plus (plus (mult) (mult)) (foo)) so that we can
8663 take advantage of the factoring cases below. */
8664 if (((TREE_CODE (arg0) == PLUS_EXPR
8665 || TREE_CODE (arg0) == MINUS_EXPR)
8666 && TREE_CODE (arg1) == MULT_EXPR)
8667 || ((TREE_CODE (arg1) == PLUS_EXPR
8668 || TREE_CODE (arg1) == MINUS_EXPR)
8669 && TREE_CODE (arg0) == MULT_EXPR))
8671 tree parg0, parg1, parg, marg;
8672 enum tree_code pcode;
8674 if (TREE_CODE (arg1) == MULT_EXPR)
8675 parg = arg0, marg = arg1;
8677 parg = arg1, marg = arg0;
8678 pcode = TREE_CODE (parg);
8679 parg0 = TREE_OPERAND (parg, 0);
8680 parg1 = TREE_OPERAND (parg, 1);
8684 if (TREE_CODE (parg0) == MULT_EXPR
8685 && TREE_CODE (parg1) != MULT_EXPR)
8686 return fold_build2 (pcode, type,
8687 fold_build2 (PLUS_EXPR, type,
8688 fold_convert (type, parg0),
8689 fold_convert (type, marg)),
8690 fold_convert (type, parg1));
8691 if (TREE_CODE (parg0) != MULT_EXPR
8692 && TREE_CODE (parg1) == MULT_EXPR)
8693 return fold_build2 (PLUS_EXPR, type,
8694 fold_convert (type, parg0),
8695 fold_build2 (pcode, type,
8696 fold_convert (type, marg),
8701 /* Try replacing &a[i1] + c * i2 with &a[i1 + i2], if c is step
8702 of the array. Loop optimizer sometimes produce this type of
8704 if (TREE_CODE (arg0) == ADDR_EXPR)
8706 tem = try_move_mult_to_index (PLUS_EXPR, arg0, arg1);
8708 return fold_convert (type, tem);
8710 else if (TREE_CODE (arg1) == ADDR_EXPR)
8712 tem = try_move_mult_to_index (PLUS_EXPR, arg1, arg0);
8714 return fold_convert (type, tem);
8719 /* See if ARG1 is zero and X + ARG1 reduces to X. */
8720 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
8721 return non_lvalue (fold_convert (type, arg0));
8723 /* Likewise if the operands are reversed. */
8724 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
8725 return non_lvalue (fold_convert (type, arg1));
8727 /* Convert X + -C into X - C. */
8728 if (TREE_CODE (arg1) == REAL_CST
8729 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
8731 tem = fold_negate_const (arg1, type);
8732 if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
8733 return fold_build2 (MINUS_EXPR, type,
8734 fold_convert (type, arg0),
8735 fold_convert (type, tem));
8738 if (flag_unsafe_math_optimizations
8739 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
8740 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
8741 && (tem = distribute_real_division (code, type, arg0, arg1)))
8744 /* Convert x+x into x*2.0. */
8745 if (operand_equal_p (arg0, arg1, 0)
8746 && SCALAR_FLOAT_TYPE_P (type))
8747 return fold_build2 (MULT_EXPR, type, arg0,
8748 build_real (type, dconst2));
8750 /* Convert a + (b*c + d*e) into (a + b*c) + d*e. */
8751 if (flag_unsafe_math_optimizations
8752 && TREE_CODE (arg1) == PLUS_EXPR
8753 && TREE_CODE (arg0) != MULT_EXPR)
8755 tree tree10 = TREE_OPERAND (arg1, 0);
8756 tree tree11 = TREE_OPERAND (arg1, 1);
8757 if (TREE_CODE (tree11) == MULT_EXPR
8758 && TREE_CODE (tree10) == MULT_EXPR)
8761 tree0 = fold_build2 (PLUS_EXPR, type, arg0, tree10);
8762 return fold_build2 (PLUS_EXPR, type, tree0, tree11);
8765 /* Convert (b*c + d*e) + a into b*c + (d*e +a). */
8766 if (flag_unsafe_math_optimizations
8767 && TREE_CODE (arg0) == PLUS_EXPR
8768 && TREE_CODE (arg1) != MULT_EXPR)
8770 tree tree00 = TREE_OPERAND (arg0, 0);
8771 tree tree01 = TREE_OPERAND (arg0, 1);
8772 if (TREE_CODE (tree01) == MULT_EXPR
8773 && TREE_CODE (tree00) == MULT_EXPR)
8776 tree0 = fold_build2 (PLUS_EXPR, type, tree01, arg1);
8777 return fold_build2 (PLUS_EXPR, type, tree00, tree0);
8783 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
8784 is a rotate of A by C1 bits. */
8785 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
8786 is a rotate of A by B bits. */
8788 enum tree_code code0, code1;
8789 code0 = TREE_CODE (arg0);
8790 code1 = TREE_CODE (arg1);
8791 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
8792 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
8793 && operand_equal_p (TREE_OPERAND (arg0, 0),
8794 TREE_OPERAND (arg1, 0), 0)
8795 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
8797 tree tree01, tree11;
8798 enum tree_code code01, code11;
8800 tree01 = TREE_OPERAND (arg0, 1);
8801 tree11 = TREE_OPERAND (arg1, 1);
8802 STRIP_NOPS (tree01);
8803 STRIP_NOPS (tree11);
8804 code01 = TREE_CODE (tree01);
8805 code11 = TREE_CODE (tree11);
8806 if (code01 == INTEGER_CST
8807 && code11 == INTEGER_CST
8808 && TREE_INT_CST_HIGH (tree01) == 0
8809 && TREE_INT_CST_HIGH (tree11) == 0
8810 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
8811 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
8812 return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
8813 code0 == LSHIFT_EXPR ? tree01 : tree11);
8814 else if (code11 == MINUS_EXPR)
8816 tree tree110, tree111;
8817 tree110 = TREE_OPERAND (tree11, 0);
8818 tree111 = TREE_OPERAND (tree11, 1);
8819 STRIP_NOPS (tree110);
8820 STRIP_NOPS (tree111);
8821 if (TREE_CODE (tree110) == INTEGER_CST
8822 && 0 == compare_tree_int (tree110,
8824 (TREE_TYPE (TREE_OPERAND
8826 && operand_equal_p (tree01, tree111, 0))
8827 return build2 ((code0 == LSHIFT_EXPR
8830 type, TREE_OPERAND (arg0, 0), tree01);
8832 else if (code01 == MINUS_EXPR)
8834 tree tree010, tree011;
8835 tree010 = TREE_OPERAND (tree01, 0);
8836 tree011 = TREE_OPERAND (tree01, 1);
8837 STRIP_NOPS (tree010);
8838 STRIP_NOPS (tree011);
8839 if (TREE_CODE (tree010) == INTEGER_CST
8840 && 0 == compare_tree_int (tree010,
8842 (TREE_TYPE (TREE_OPERAND
8844 && operand_equal_p (tree11, tree011, 0))
8845 return build2 ((code0 != LSHIFT_EXPR
8848 type, TREE_OPERAND (arg0, 0), tree11);
8854 /* In most languages, can't associate operations on floats through
8855 parentheses. Rather than remember where the parentheses were, we
8856 don't associate floats at all, unless the user has specified
8857 -funsafe-math-optimizations. */
8859 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
8861 tree var0, con0, lit0, minus_lit0;
8862 tree var1, con1, lit1, minus_lit1;
8865 /* Split both trees into variables, constants, and literals. Then
8866 associate each group together, the constants with literals,
8867 then the result with variables. This increases the chances of
8868 literals being recombined later and of generating relocatable
8869 expressions for the sum of a constant and literal. */
8870 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
8871 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
8872 code == MINUS_EXPR);
8874 /* With undefined overflow we can only associate constants
8875 with one variable. */
8876 if ((POINTER_TYPE_P (type)
8877 || (INTEGRAL_TYPE_P (type)
8878 && !(TYPE_UNSIGNED (type) || flag_wrapv)))
8884 if (TREE_CODE (tmp0) == NEGATE_EXPR)
8885 tmp0 = TREE_OPERAND (tmp0, 0);
8886 if (TREE_CODE (tmp1) == NEGATE_EXPR)
8887 tmp1 = TREE_OPERAND (tmp1, 0);
8888 /* The only case we can still associate with two variables
8889 is if they are the same, modulo negation. */
8890 if (!operand_equal_p (tmp0, tmp1, 0))
8894 /* Only do something if we found more than two objects. Otherwise,
8895 nothing has changed and we risk infinite recursion. */
8897 && (2 < ((var0 != 0) + (var1 != 0)
8898 + (con0 != 0) + (con1 != 0)
8899 + (lit0 != 0) + (lit1 != 0)
8900 + (minus_lit0 != 0) + (minus_lit1 != 0))))
8902 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
8903 if (code == MINUS_EXPR)
8906 var0 = associate_trees (var0, var1, code, type);
8907 con0 = associate_trees (con0, con1, code, type);
8908 lit0 = associate_trees (lit0, lit1, code, type);
8909 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
8911 /* Preserve the MINUS_EXPR if the negative part of the literal is
8912 greater than the positive part. Otherwise, the multiplicative
8913 folding code (i.e extract_muldiv) may be fooled in case
8914 unsigned constants are subtracted, like in the following
8915 example: ((X*2 + 4) - 8U)/2. */
8916 if (minus_lit0 && lit0)
8918 if (TREE_CODE (lit0) == INTEGER_CST
8919 && TREE_CODE (minus_lit0) == INTEGER_CST
8920 && tree_int_cst_lt (lit0, minus_lit0))
8922 minus_lit0 = associate_trees (minus_lit0, lit0,
8928 lit0 = associate_trees (lit0, minus_lit0,
8936 return fold_convert (type,
8937 associate_trees (var0, minus_lit0,
8941 con0 = associate_trees (con0, minus_lit0,
8943 return fold_convert (type,
8944 associate_trees (var0, con0,
8949 con0 = associate_trees (con0, lit0, code, type);
8950 return fold_convert (type, associate_trees (var0, con0,
8958 /* A - (-B) -> A + B */
8959 if (TREE_CODE (arg1) == NEGATE_EXPR)
8960 return fold_build2 (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0));
8961 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
8962 if (TREE_CODE (arg0) == NEGATE_EXPR
8963 && (FLOAT_TYPE_P (type)
8964 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
8965 && negate_expr_p (arg1)
8966 && reorder_operands_p (arg0, arg1))
8967 return fold_build2 (MINUS_EXPR, type, negate_expr (arg1),
8968 TREE_OPERAND (arg0, 0));
8969 /* Convert -A - 1 to ~A. */
8970 if (INTEGRAL_TYPE_P (type)
8971 && TREE_CODE (arg0) == NEGATE_EXPR
8972 && integer_onep (arg1))
8973 return fold_build1 (BIT_NOT_EXPR, type,
8974 fold_convert (type, TREE_OPERAND (arg0, 0)));
8976 /* Convert -1 - A to ~A. */
8977 if (INTEGRAL_TYPE_P (type)
8978 && integer_all_onesp (arg0))
8979 return fold_build1 (BIT_NOT_EXPR, type, arg1);
8981 if (! FLOAT_TYPE_P (type))
8983 if (integer_zerop (arg0))
8984 return negate_expr (fold_convert (type, arg1));
8985 if (integer_zerop (arg1))
8986 return non_lvalue (fold_convert (type, arg0));
8988 /* Fold A - (A & B) into ~B & A. */
8989 if (!TREE_SIDE_EFFECTS (arg0)
8990 && TREE_CODE (arg1) == BIT_AND_EXPR)
8992 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
8993 return fold_build2 (BIT_AND_EXPR, type,
8994 fold_build1 (BIT_NOT_EXPR, type,
8995 TREE_OPERAND (arg1, 0)),
8997 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8998 return fold_build2 (BIT_AND_EXPR, type,
8999 fold_build1 (BIT_NOT_EXPR, type,
9000 TREE_OPERAND (arg1, 1)),
9004 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
9005 any power of 2 minus 1. */
9006 if (TREE_CODE (arg0) == BIT_AND_EXPR
9007 && TREE_CODE (arg1) == BIT_AND_EXPR
9008 && operand_equal_p (TREE_OPERAND (arg0, 0),
9009 TREE_OPERAND (arg1, 0), 0))
9011 tree mask0 = TREE_OPERAND (arg0, 1);
9012 tree mask1 = TREE_OPERAND (arg1, 1);
9013 tree tem = fold_build1 (BIT_NOT_EXPR, type, mask0);
9015 if (operand_equal_p (tem, mask1, 0))
9017 tem = fold_build2 (BIT_XOR_EXPR, type,
9018 TREE_OPERAND (arg0, 0), mask1);
9019 return fold_build2 (MINUS_EXPR, type, tem, mask1);
9024 /* See if ARG1 is zero and X - ARG1 reduces to X. */
9025 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
9026 return non_lvalue (fold_convert (type, arg0));
9028 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
9029 ARG0 is zero and X + ARG0 reduces to X, since that would mean
9030 (-ARG1 + ARG0) reduces to -ARG1. */
9031 else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
9032 return negate_expr (fold_convert (type, arg1));
9034 /* Fold &x - &x. This can happen from &x.foo - &x.
9035 This is unsafe for certain floats even in non-IEEE formats.
9036 In IEEE, it is unsafe because it does wrong for NaNs.
9037 Also note that operand_equal_p is always false if an operand
9040 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
9041 && operand_equal_p (arg0, arg1, 0))
9042 return fold_convert (type, integer_zero_node);
9044 /* A - B -> A + (-B) if B is easily negatable. */
9045 if (negate_expr_p (arg1)
9046 && ((FLOAT_TYPE_P (type)
9047 /* Avoid this transformation if B is a positive REAL_CST. */
9048 && (TREE_CODE (arg1) != REAL_CST
9049 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
9050 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv)))
9051 return fold_build2 (PLUS_EXPR, type,
9052 fold_convert (type, arg0),
9053 fold_convert (type, negate_expr (arg1)));
9055 /* Try folding difference of addresses. */
9059 if ((TREE_CODE (arg0) == ADDR_EXPR
9060 || TREE_CODE (arg1) == ADDR_EXPR)
9061 && ptr_difference_const (arg0, arg1, &diff))
9062 return build_int_cst_type (type, diff);
9065 /* Fold &a[i] - &a[j] to i-j. */
9066 if (TREE_CODE (arg0) == ADDR_EXPR
9067 && TREE_CODE (TREE_OPERAND (arg0, 0)) == ARRAY_REF
9068 && TREE_CODE (arg1) == ADDR_EXPR
9069 && TREE_CODE (TREE_OPERAND (arg1, 0)) == ARRAY_REF)
9071 tree aref0 = TREE_OPERAND (arg0, 0);
9072 tree aref1 = TREE_OPERAND (arg1, 0);
9073 if (operand_equal_p (TREE_OPERAND (aref0, 0),
9074 TREE_OPERAND (aref1, 0), 0))
9076 tree op0 = fold_convert (type, TREE_OPERAND (aref0, 1));
9077 tree op1 = fold_convert (type, TREE_OPERAND (aref1, 1));
9078 tree esz = array_ref_element_size (aref0);
9079 tree diff = build2 (MINUS_EXPR, type, op0, op1);
9080 return fold_build2 (MULT_EXPR, type, diff,
9081 fold_convert (type, esz));
9086 /* Try replacing &a[i1] - c * i2 with &a[i1 - i2], if c is step
9087 of the array. Loop optimizer sometimes produce this type of
9089 if (TREE_CODE (arg0) == ADDR_EXPR)
9091 tem = try_move_mult_to_index (MINUS_EXPR, arg0, arg1);
9093 return fold_convert (type, tem);
9096 if (flag_unsafe_math_optimizations
9097 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
9098 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
9099 && (tem = distribute_real_division (code, type, arg0, arg1)))
9102 /* Handle (A1 * C1) - (A2 * C2) with A1, A2 or C1, C2 being the
9104 if ((TREE_CODE (arg0) == MULT_EXPR
9105 || TREE_CODE (arg1) == MULT_EXPR)
9106 && (!FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
9108 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
9116 /* (-A) * (-B) -> A * B */
9117 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
9118 return fold_build2 (MULT_EXPR, type,
9119 fold_convert (type, TREE_OPERAND (arg0, 0)),
9120 fold_convert (type, negate_expr (arg1)));
9121 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
9122 return fold_build2 (MULT_EXPR, type,
9123 fold_convert (type, negate_expr (arg0)),
9124 fold_convert (type, TREE_OPERAND (arg1, 0)));
9126 if (! FLOAT_TYPE_P (type))
9128 if (integer_zerop (arg1))
9129 return omit_one_operand (type, arg1, arg0);
9130 if (integer_onep (arg1))
9131 return non_lvalue (fold_convert (type, arg0));
9132 /* Transform x * -1 into -x. */
9133 if (integer_all_onesp (arg1))
9134 return fold_convert (type, negate_expr (arg0));
9136 /* (a * (1 << b)) is (a << b) */
9137 if (TREE_CODE (arg1) == LSHIFT_EXPR
9138 && integer_onep (TREE_OPERAND (arg1, 0)))
9139 return fold_build2 (LSHIFT_EXPR, type, arg0,
9140 TREE_OPERAND (arg1, 1));
9141 if (TREE_CODE (arg0) == LSHIFT_EXPR
9142 && integer_onep (TREE_OPERAND (arg0, 0)))
9143 return fold_build2 (LSHIFT_EXPR, type, arg1,
9144 TREE_OPERAND (arg0, 1));
9146 strict_overflow_p = false;
9147 if (TREE_CODE (arg1) == INTEGER_CST
9148 && 0 != (tem = extract_muldiv (op0,
9149 fold_convert (type, arg1),
9151 &strict_overflow_p)))
9153 if (strict_overflow_p)
9154 fold_overflow_warning (("assuming signed overflow does not "
9155 "occur when simplifying "
9157 WARN_STRICT_OVERFLOW_MISC);
9158 return fold_convert (type, tem);
9161 /* Optimize z * conj(z) for integer complex numbers. */
9162 if (TREE_CODE (arg0) == CONJ_EXPR
9163 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
9164 return fold_mult_zconjz (type, arg1);
9165 if (TREE_CODE (arg1) == CONJ_EXPR
9166 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
9167 return fold_mult_zconjz (type, arg0);
9171 /* Maybe fold x * 0 to 0. The expressions aren't the same
9172 when x is NaN, since x * 0 is also NaN. Nor are they the
9173 same in modes with signed zeros, since multiplying a
9174 negative value by 0 gives -0, not +0. */
9175 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
9176 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
9177 && real_zerop (arg1))
9178 return omit_one_operand (type, arg1, arg0);
9179 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
9180 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
9181 && real_onep (arg1))
9182 return non_lvalue (fold_convert (type, arg0));
9184 /* Transform x * -1.0 into -x. */
9185 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
9186 && real_minus_onep (arg1))
9187 return fold_convert (type, negate_expr (arg0));
9189 /* Convert (C1/X)*C2 into (C1*C2)/X. */
9190 if (flag_unsafe_math_optimizations
9191 && TREE_CODE (arg0) == RDIV_EXPR
9192 && TREE_CODE (arg1) == REAL_CST
9193 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
9195 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
9198 return fold_build2 (RDIV_EXPR, type, tem,
9199 TREE_OPERAND (arg0, 1));
9202 /* Strip sign operations from X in X*X, i.e. -Y*-Y -> Y*Y. */
9203 if (operand_equal_p (arg0, arg1, 0))
9205 tree tem = fold_strip_sign_ops (arg0);
9206 if (tem != NULL_TREE)
9208 tem = fold_convert (type, tem);
9209 return fold_build2 (MULT_EXPR, type, tem, tem);
9213 /* Optimize z * conj(z) for floating point complex numbers.
9214 Guarded by flag_unsafe_math_optimizations as non-finite
9215 imaginary components don't produce scalar results. */
9216 if (flag_unsafe_math_optimizations
9217 && TREE_CODE (arg0) == CONJ_EXPR
9218 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
9219 return fold_mult_zconjz (type, arg1);
9220 if (flag_unsafe_math_optimizations
9221 && TREE_CODE (arg1) == CONJ_EXPR
9222 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
9223 return fold_mult_zconjz (type, arg0);
9225 if (flag_unsafe_math_optimizations)
9227 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
9228 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
9230 /* Optimizations of root(...)*root(...). */
9231 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
9233 tree rootfn, arg, arglist;
9234 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
9235 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
9237 /* Optimize sqrt(x)*sqrt(x) as x. */
9238 if (BUILTIN_SQRT_P (fcode0)
9239 && operand_equal_p (arg00, arg10, 0)
9240 && ! HONOR_SNANS (TYPE_MODE (type)))
9243 /* Optimize root(x)*root(y) as root(x*y). */
9244 rootfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
9245 arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
9246 arglist = build_tree_list (NULL_TREE, arg);
9247 return build_function_call_expr (rootfn, arglist);
9250 /* Optimize expN(x)*expN(y) as expN(x+y). */
9251 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
9253 tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
9254 tree arg = fold_build2 (PLUS_EXPR, type,
9255 TREE_VALUE (TREE_OPERAND (arg0, 1)),
9256 TREE_VALUE (TREE_OPERAND (arg1, 1)));
9257 tree arglist = build_tree_list (NULL_TREE, arg);
9258 return build_function_call_expr (expfn, arglist);
9261 /* Optimizations of pow(...)*pow(...). */
9262 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
9263 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
9264 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
9266 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
9267 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
9269 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
9270 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
9273 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
9274 if (operand_equal_p (arg01, arg11, 0))
9276 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
9277 tree arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
9278 tree arglist = tree_cons (NULL_TREE, arg,
9279 build_tree_list (NULL_TREE,
9281 return build_function_call_expr (powfn, arglist);
9284 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
9285 if (operand_equal_p (arg00, arg10, 0))
9287 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
9288 tree arg = fold_build2 (PLUS_EXPR, type, arg01, arg11);
9289 tree arglist = tree_cons (NULL_TREE, arg00,
9290 build_tree_list (NULL_TREE,
9292 return build_function_call_expr (powfn, arglist);
9296 /* Optimize tan(x)*cos(x) as sin(x). */
9297 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
9298 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
9299 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
9300 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
9301 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
9302 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
9303 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
9304 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
9306 tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
9308 if (sinfn != NULL_TREE)
9309 return build_function_call_expr (sinfn,
9310 TREE_OPERAND (arg0, 1));
9313 /* Optimize x*pow(x,c) as pow(x,c+1). */
9314 if (fcode1 == BUILT_IN_POW
9315 || fcode1 == BUILT_IN_POWF
9316 || fcode1 == BUILT_IN_POWL)
9318 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
9319 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
9321 if (TREE_CODE (arg11) == REAL_CST
9322 && ! TREE_CONSTANT_OVERFLOW (arg11)
9323 && operand_equal_p (arg0, arg10, 0))
9325 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
9329 c = TREE_REAL_CST (arg11);
9330 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
9331 arg = build_real (type, c);
9332 arglist = build_tree_list (NULL_TREE, arg);
9333 arglist = tree_cons (NULL_TREE, arg0, arglist);
9334 return build_function_call_expr (powfn, arglist);
9338 /* Optimize pow(x,c)*x as pow(x,c+1). */
9339 if (fcode0 == BUILT_IN_POW
9340 || fcode0 == BUILT_IN_POWF
9341 || fcode0 == BUILT_IN_POWL)
9343 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
9344 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
9346 if (TREE_CODE (arg01) == REAL_CST
9347 && ! TREE_CONSTANT_OVERFLOW (arg01)
9348 && operand_equal_p (arg1, arg00, 0))
9350 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
9354 c = TREE_REAL_CST (arg01);
9355 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
9356 arg = build_real (type, c);
9357 arglist = build_tree_list (NULL_TREE, arg);
9358 arglist = tree_cons (NULL_TREE, arg1, arglist);
9359 return build_function_call_expr (powfn, arglist);
9363 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
9365 && operand_equal_p (arg0, arg1, 0))
9367 tree powfn = mathfn_built_in (type, BUILT_IN_POW);
9371 tree arg = build_real (type, dconst2);
9372 tree arglist = build_tree_list (NULL_TREE, arg);
9373 arglist = tree_cons (NULL_TREE, arg0, arglist);
9374 return build_function_call_expr (powfn, arglist);
9383 if (integer_all_onesp (arg1))
9384 return omit_one_operand (type, arg1, arg0);
9385 if (integer_zerop (arg1))
9386 return non_lvalue (fold_convert (type, arg0));
9387 if (operand_equal_p (arg0, arg1, 0))
9388 return non_lvalue (fold_convert (type, arg0));
9391 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9392 && INTEGRAL_TYPE_P (TREE_TYPE (arg1))
9393 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
9395 t1 = build_int_cst (type, -1);
9396 t1 = force_fit_type (t1, 0, false, false);
9397 return omit_one_operand (type, t1, arg1);
9401 if (TREE_CODE (arg1) == BIT_NOT_EXPR
9402 && INTEGRAL_TYPE_P (TREE_TYPE (arg0))
9403 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
9405 t1 = build_int_cst (type, -1);
9406 t1 = force_fit_type (t1, 0, false, false);
9407 return omit_one_operand (type, t1, arg0);
9410 /* Canonicalize (X & C1) | C2. */
9411 if (TREE_CODE (arg0) == BIT_AND_EXPR
9412 && TREE_CODE (arg1) == INTEGER_CST
9413 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
9415 unsigned HOST_WIDE_INT hi1, lo1, hi2, lo2, mlo, mhi;
9416 int width = TYPE_PRECISION (type);
9417 hi1 = TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1));
9418 lo1 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
9419 hi2 = TREE_INT_CST_HIGH (arg1);
9420 lo2 = TREE_INT_CST_LOW (arg1);
9422 /* If (C1&C2) == C1, then (X&C1)|C2 becomes (X,C2). */
9423 if ((hi1 & hi2) == hi1 && (lo1 & lo2) == lo1)
9424 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
9426 if (width > HOST_BITS_PER_WIDE_INT)
9428 mhi = (unsigned HOST_WIDE_INT) -1
9429 >> (2 * HOST_BITS_PER_WIDE_INT - width);
9435 mlo = (unsigned HOST_WIDE_INT) -1
9436 >> (HOST_BITS_PER_WIDE_INT - width);
9439 /* If (C1|C2) == ~0 then (X&C1)|C2 becomes X|C2. */
9440 if ((~(hi1 | hi2) & mhi) == 0 && (~(lo1 | lo2) & mlo) == 0)
9441 return fold_build2 (BIT_IOR_EXPR, type,
9442 TREE_OPERAND (arg0, 0), arg1);
9444 /* Minimize the number of bits set in C1, i.e. C1 := C1 & ~C2. */
9447 if ((hi1 & ~hi2) != hi1 || (lo1 & ~lo2) != lo1)
9448 return fold_build2 (BIT_IOR_EXPR, type,
9449 fold_build2 (BIT_AND_EXPR, type,
9450 TREE_OPERAND (arg0, 0),
9451 build_int_cst_wide (type,
9457 /* (X & Y) | Y is (X, Y). */
9458 if (TREE_CODE (arg0) == BIT_AND_EXPR
9459 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
9460 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
9461 /* (X & Y) | X is (Y, X). */
9462 if (TREE_CODE (arg0) == BIT_AND_EXPR
9463 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
9464 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
9465 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
9466 /* X | (X & Y) is (Y, X). */
9467 if (TREE_CODE (arg1) == BIT_AND_EXPR
9468 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
9469 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
9470 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
9471 /* X | (Y & X) is (Y, X). */
9472 if (TREE_CODE (arg1) == BIT_AND_EXPR
9473 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
9474 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
9475 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
9477 t1 = distribute_bit_expr (code, type, arg0, arg1);
9478 if (t1 != NULL_TREE)
9481 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
9483 This results in more efficient code for machines without a NAND
9484 instruction. Combine will canonicalize to the first form
9485 which will allow use of NAND instructions provided by the
9486 backend if they exist. */
9487 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9488 && TREE_CODE (arg1) == BIT_NOT_EXPR)
9490 return fold_build1 (BIT_NOT_EXPR, type,
9491 build2 (BIT_AND_EXPR, type,
9492 TREE_OPERAND (arg0, 0),
9493 TREE_OPERAND (arg1, 0)));
9496 /* See if this can be simplified into a rotate first. If that
9497 is unsuccessful continue in the association code. */
9501 if (integer_zerop (arg1))
9502 return non_lvalue (fold_convert (type, arg0));
9503 if (integer_all_onesp (arg1))
9504 return fold_build1 (BIT_NOT_EXPR, type, arg0);
9505 if (operand_equal_p (arg0, arg1, 0))
9506 return omit_one_operand (type, integer_zero_node, arg0);
9509 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9510 && INTEGRAL_TYPE_P (TREE_TYPE (arg1))
9511 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
9513 t1 = build_int_cst (type, -1);
9514 t1 = force_fit_type (t1, 0, false, false);
9515 return omit_one_operand (type, t1, arg1);
9519 if (TREE_CODE (arg1) == BIT_NOT_EXPR
9520 && INTEGRAL_TYPE_P (TREE_TYPE (arg0))
9521 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
9523 t1 = build_int_cst (type, -1);
9524 t1 = force_fit_type (t1, 0, false, false);
9525 return omit_one_operand (type, t1, arg0);
9528 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
9529 with a constant, and the two constants have no bits in common,
9530 we should treat this as a BIT_IOR_EXPR since this may produce more
9532 if (TREE_CODE (arg0) == BIT_AND_EXPR
9533 && TREE_CODE (arg1) == BIT_AND_EXPR
9534 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9535 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
9536 && integer_zerop (const_binop (BIT_AND_EXPR,
9537 TREE_OPERAND (arg0, 1),
9538 TREE_OPERAND (arg1, 1), 0)))
9540 code = BIT_IOR_EXPR;
9544 /* (X | Y) ^ X -> Y & ~ X*/
9545 if (TREE_CODE (arg0) == BIT_IOR_EXPR
9546 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
9548 tree t2 = TREE_OPERAND (arg0, 1);
9549 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
9551 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
9552 fold_convert (type, t1));
9556 /* (Y | X) ^ X -> Y & ~ X*/
9557 if (TREE_CODE (arg0) == BIT_IOR_EXPR
9558 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
9560 tree t2 = TREE_OPERAND (arg0, 0);
9561 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
9563 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
9564 fold_convert (type, t1));
9568 /* X ^ (X | Y) -> Y & ~ X*/
9569 if (TREE_CODE (arg1) == BIT_IOR_EXPR
9570 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
9572 tree t2 = TREE_OPERAND (arg1, 1);
9573 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
9575 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
9576 fold_convert (type, t1));
9580 /* X ^ (Y | X) -> Y & ~ X*/
9581 if (TREE_CODE (arg1) == BIT_IOR_EXPR
9582 && operand_equal_p (TREE_OPERAND (arg1, 1), arg0, 0))
9584 tree t2 = TREE_OPERAND (arg1, 0);
9585 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
9587 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
9588 fold_convert (type, t1));
9592 /* Convert ~X ^ ~Y to X ^ Y. */
9593 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9594 && TREE_CODE (arg1) == BIT_NOT_EXPR)
9595 return fold_build2 (code, type,
9596 fold_convert (type, TREE_OPERAND (arg0, 0)),
9597 fold_convert (type, TREE_OPERAND (arg1, 0)));
9599 /* Fold (X & 1) ^ 1 as (X & 1) == 0. */
9600 if (TREE_CODE (arg0) == BIT_AND_EXPR
9601 && integer_onep (TREE_OPERAND (arg0, 1))
9602 && integer_onep (arg1))
9603 return fold_build2 (EQ_EXPR, type, arg0,
9604 build_int_cst (TREE_TYPE (arg0), 0));
9606 /* Fold (X & Y) ^ Y as ~X & Y. */
9607 if (TREE_CODE (arg0) == BIT_AND_EXPR
9608 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
9610 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
9611 return fold_build2 (BIT_AND_EXPR, type,
9612 fold_build1 (BIT_NOT_EXPR, type, tem),
9613 fold_convert (type, arg1));
9615 /* Fold (X & Y) ^ X as ~Y & X. */
9616 if (TREE_CODE (arg0) == BIT_AND_EXPR
9617 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
9618 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
9620 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
9621 return fold_build2 (BIT_AND_EXPR, type,
9622 fold_build1 (BIT_NOT_EXPR, type, tem),
9623 fold_convert (type, arg1));
9625 /* Fold X ^ (X & Y) as X & ~Y. */
9626 if (TREE_CODE (arg1) == BIT_AND_EXPR
9627 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
9629 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
9630 return fold_build2 (BIT_AND_EXPR, type,
9631 fold_convert (type, arg0),
9632 fold_build1 (BIT_NOT_EXPR, type, tem));
9634 /* Fold X ^ (Y & X) as ~Y & X. */
9635 if (TREE_CODE (arg1) == BIT_AND_EXPR
9636 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
9637 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
9639 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
9640 return fold_build2 (BIT_AND_EXPR, type,
9641 fold_build1 (BIT_NOT_EXPR, type, tem),
9642 fold_convert (type, arg0));
9645 /* See if this can be simplified into a rotate first. If that
9646 is unsuccessful continue in the association code. */
9650 if (integer_all_onesp (arg1))
9651 return non_lvalue (fold_convert (type, arg0));
9652 if (integer_zerop (arg1))
9653 return omit_one_operand (type, arg1, arg0);
9654 if (operand_equal_p (arg0, arg1, 0))
9655 return non_lvalue (fold_convert (type, arg0));
9657 /* ~X & X is always zero. */
9658 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9659 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
9660 return omit_one_operand (type, integer_zero_node, arg1);
9662 /* X & ~X is always zero. */
9663 if (TREE_CODE (arg1) == BIT_NOT_EXPR
9664 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
9665 return omit_one_operand (type, integer_zero_node, arg0);
9667 /* Canonicalize (X | C1) & C2 as (X & C2) | (C1 & C2). */
9668 if (TREE_CODE (arg0) == BIT_IOR_EXPR
9669 && TREE_CODE (arg1) == INTEGER_CST
9670 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
9671 return fold_build2 (BIT_IOR_EXPR, type,
9672 fold_build2 (BIT_AND_EXPR, type,
9673 TREE_OPERAND (arg0, 0), arg1),
9674 fold_build2 (BIT_AND_EXPR, type,
9675 TREE_OPERAND (arg0, 1), arg1));
9677 /* (X | Y) & Y is (X, Y). */
9678 if (TREE_CODE (arg0) == BIT_IOR_EXPR
9679 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
9680 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
9681 /* (X | Y) & X is (Y, X). */
9682 if (TREE_CODE (arg0) == BIT_IOR_EXPR
9683 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
9684 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
9685 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
9686 /* X & (X | Y) is (Y, X). */
9687 if (TREE_CODE (arg1) == BIT_IOR_EXPR
9688 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
9689 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
9690 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
9691 /* X & (Y | X) is (Y, X). */
9692 if (TREE_CODE (arg1) == BIT_IOR_EXPR
9693 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
9694 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
9695 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
9697 /* Fold (X ^ 1) & 1 as (X & 1) == 0. */
9698 if (TREE_CODE (arg0) == BIT_XOR_EXPR
9699 && integer_onep (TREE_OPERAND (arg0, 1))
9700 && integer_onep (arg1))
9702 tem = TREE_OPERAND (arg0, 0);
9703 return fold_build2 (EQ_EXPR, type,
9704 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
9705 build_int_cst (TREE_TYPE (tem), 1)),
9706 build_int_cst (TREE_TYPE (tem), 0));
9708 /* Fold ~X & 1 as (X & 1) == 0. */
9709 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9710 && integer_onep (arg1))
9712 tem = TREE_OPERAND (arg0, 0);
9713 return fold_build2 (EQ_EXPR, type,
9714 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
9715 build_int_cst (TREE_TYPE (tem), 1)),
9716 build_int_cst (TREE_TYPE (tem), 0));
9719 /* Fold (X ^ Y) & Y as ~X & Y. */
9720 if (TREE_CODE (arg0) == BIT_XOR_EXPR
9721 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
9723 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
9724 return fold_build2 (BIT_AND_EXPR, type,
9725 fold_build1 (BIT_NOT_EXPR, type, tem),
9726 fold_convert (type, arg1));
9728 /* Fold (X ^ Y) & X as ~Y & X. */
9729 if (TREE_CODE (arg0) == BIT_XOR_EXPR
9730 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
9731 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
9733 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
9734 return fold_build2 (BIT_AND_EXPR, type,
9735 fold_build1 (BIT_NOT_EXPR, type, tem),
9736 fold_convert (type, arg1));
9738 /* Fold X & (X ^ Y) as X & ~Y. */
9739 if (TREE_CODE (arg1) == BIT_XOR_EXPR
9740 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
9742 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
9743 return fold_build2 (BIT_AND_EXPR, type,
9744 fold_convert (type, arg0),
9745 fold_build1 (BIT_NOT_EXPR, type, tem));
9747 /* Fold X & (Y ^ X) as ~Y & X. */
9748 if (TREE_CODE (arg1) == BIT_XOR_EXPR
9749 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
9750 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
9752 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
9753 return fold_build2 (BIT_AND_EXPR, type,
9754 fold_build1 (BIT_NOT_EXPR, type, tem),
9755 fold_convert (type, arg0));
9758 t1 = distribute_bit_expr (code, type, arg0, arg1);
9759 if (t1 != NULL_TREE)
9761 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
9762 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
9763 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
9766 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
9768 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
9769 && (~TREE_INT_CST_LOW (arg1)
9770 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
9771 return fold_convert (type, TREE_OPERAND (arg0, 0));
9774 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
9776 This results in more efficient code for machines without a NOR
9777 instruction. Combine will canonicalize to the first form
9778 which will allow use of NOR instructions provided by the
9779 backend if they exist. */
9780 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9781 && TREE_CODE (arg1) == BIT_NOT_EXPR)
9783 return fold_build1 (BIT_NOT_EXPR, type,
9784 build2 (BIT_IOR_EXPR, type,
9785 TREE_OPERAND (arg0, 0),
9786 TREE_OPERAND (arg1, 0)));
9792 /* Don't touch a floating-point divide by zero unless the mode
9793 of the constant can represent infinity. */
9794 if (TREE_CODE (arg1) == REAL_CST
9795 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
9796 && real_zerop (arg1))
9799 /* Optimize A / A to 1.0 if we don't care about
9800 NaNs or Infinities. Skip the transformation
9801 for non-real operands. */
9802 if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (arg0))
9803 && ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
9804 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg0)))
9805 && operand_equal_p (arg0, arg1, 0))
9807 tree r = build_real (TREE_TYPE (arg0), dconst1);
9809 return omit_two_operands (type, r, arg0, arg1);
9812 /* The complex version of the above A / A optimization. */
9813 if (COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
9814 && operand_equal_p (arg0, arg1, 0))
9816 tree elem_type = TREE_TYPE (TREE_TYPE (arg0));
9817 if (! HONOR_NANS (TYPE_MODE (elem_type))
9818 && ! HONOR_INFINITIES (TYPE_MODE (elem_type)))
9820 tree r = build_real (elem_type, dconst1);
9821 /* omit_two_operands will call fold_convert for us. */
9822 return omit_two_operands (type, r, arg0, arg1);
9826 /* (-A) / (-B) -> A / B */
9827 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
9828 return fold_build2 (RDIV_EXPR, type,
9829 TREE_OPERAND (arg0, 0),
9830 negate_expr (arg1));
9831 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
9832 return fold_build2 (RDIV_EXPR, type,
9834 TREE_OPERAND (arg1, 0));
9836 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
9837 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
9838 && real_onep (arg1))
9839 return non_lvalue (fold_convert (type, arg0));
9841 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
9842 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
9843 && real_minus_onep (arg1))
9844 return non_lvalue (fold_convert (type, negate_expr (arg0)));
9846 /* If ARG1 is a constant, we can convert this to a multiply by the
9847 reciprocal. This does not have the same rounding properties,
9848 so only do this if -funsafe-math-optimizations. We can actually
9849 always safely do it if ARG1 is a power of two, but it's hard to
9850 tell if it is or not in a portable manner. */
9851 if (TREE_CODE (arg1) == REAL_CST)
9853 if (flag_unsafe_math_optimizations
9854 && 0 != (tem = const_binop (code, build_real (type, dconst1),
9856 return fold_build2 (MULT_EXPR, type, arg0, tem);
9857 /* Find the reciprocal if optimizing and the result is exact. */
9861 r = TREE_REAL_CST (arg1);
9862 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
9864 tem = build_real (type, r);
9865 return fold_build2 (MULT_EXPR, type,
9866 fold_convert (type, arg0), tem);
9870 /* Convert A/B/C to A/(B*C). */
9871 if (flag_unsafe_math_optimizations
9872 && TREE_CODE (arg0) == RDIV_EXPR)
9873 return fold_build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
9874 fold_build2 (MULT_EXPR, type,
9875 TREE_OPERAND (arg0, 1), arg1));
9877 /* Convert A/(B/C) to (A/B)*C. */
9878 if (flag_unsafe_math_optimizations
9879 && TREE_CODE (arg1) == RDIV_EXPR)
9880 return fold_build2 (MULT_EXPR, type,
9881 fold_build2 (RDIV_EXPR, type, arg0,
9882 TREE_OPERAND (arg1, 0)),
9883 TREE_OPERAND (arg1, 1));
9885 /* Convert C1/(X*C2) into (C1/C2)/X. */
9886 if (flag_unsafe_math_optimizations
9887 && TREE_CODE (arg1) == MULT_EXPR
9888 && TREE_CODE (arg0) == REAL_CST
9889 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
9891 tree tem = const_binop (RDIV_EXPR, arg0,
9892 TREE_OPERAND (arg1, 1), 0);
9894 return fold_build2 (RDIV_EXPR, type, tem,
9895 TREE_OPERAND (arg1, 0));
9898 if (flag_unsafe_math_optimizations)
9900 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
9901 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
9903 /* Optimize sin(x)/cos(x) as tan(x). */
9904 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
9905 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
9906 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
9907 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
9908 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
9910 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
9912 if (tanfn != NULL_TREE)
9913 return build_function_call_expr (tanfn,
9914 TREE_OPERAND (arg0, 1));
9917 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
9918 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
9919 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
9920 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
9921 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
9922 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
9924 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
9926 if (tanfn != NULL_TREE)
9928 tree tmp = TREE_OPERAND (arg0, 1);
9929 tmp = build_function_call_expr (tanfn, tmp);
9930 return fold_build2 (RDIV_EXPR, type,
9931 build_real (type, dconst1), tmp);
9935 /* Optimize sin(x)/tan(x) as cos(x) if we don't care about
9936 NaNs or Infinities. */
9937 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_TAN)
9938 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_TANF)
9939 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_TANL)))
9941 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
9942 tree arg01 = TREE_VALUE (TREE_OPERAND (arg1, 1));
9944 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
9945 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
9946 && operand_equal_p (arg00, arg01, 0))
9948 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
9950 if (cosfn != NULL_TREE)
9951 return build_function_call_expr (cosfn,
9952 TREE_OPERAND (arg0, 1));
9956 /* Optimize tan(x)/sin(x) as 1.0/cos(x) if we don't care about
9957 NaNs or Infinities. */
9958 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_SIN)
9959 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_SINF)
9960 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_SINL)))
9962 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
9963 tree arg01 = TREE_VALUE (TREE_OPERAND (arg1, 1));
9965 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
9966 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
9967 && operand_equal_p (arg00, arg01, 0))
9969 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
9971 if (cosfn != NULL_TREE)
9973 tree tmp = TREE_OPERAND (arg0, 1);
9974 tmp = build_function_call_expr (cosfn, tmp);
9975 return fold_build2 (RDIV_EXPR, type,
9976 build_real (type, dconst1),
9982 /* Optimize pow(x,c)/x as pow(x,c-1). */
9983 if (fcode0 == BUILT_IN_POW
9984 || fcode0 == BUILT_IN_POWF
9985 || fcode0 == BUILT_IN_POWL)
9987 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
9988 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0, 1)));
9989 if (TREE_CODE (arg01) == REAL_CST
9990 && ! TREE_CONSTANT_OVERFLOW (arg01)
9991 && operand_equal_p (arg1, arg00, 0))
9993 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
9997 c = TREE_REAL_CST (arg01);
9998 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
9999 arg = build_real (type, c);
10000 arglist = build_tree_list (NULL_TREE, arg);
10001 arglist = tree_cons (NULL_TREE, arg1, arglist);
10002 return build_function_call_expr (powfn, arglist);
10006 /* Optimize x/expN(y) into x*expN(-y). */
10007 if (BUILTIN_EXPONENT_P (fcode1))
10009 tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
10010 tree arg = negate_expr (TREE_VALUE (TREE_OPERAND (arg1, 1)));
10011 tree arglist = build_tree_list (NULL_TREE,
10012 fold_convert (type, arg));
10013 arg1 = build_function_call_expr (expfn, arglist);
10014 return fold_build2 (MULT_EXPR, type, arg0, arg1);
10017 /* Optimize x/pow(y,z) into x*pow(y,-z). */
10018 if (fcode1 == BUILT_IN_POW
10019 || fcode1 == BUILT_IN_POWF
10020 || fcode1 == BUILT_IN_POWL)
10022 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
10023 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
10024 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
10025 tree neg11 = fold_convert (type, negate_expr (arg11));
10026 tree arglist = tree_cons(NULL_TREE, arg10,
10027 build_tree_list (NULL_TREE, neg11));
10028 arg1 = build_function_call_expr (powfn, arglist);
10029 return fold_build2 (MULT_EXPR, type, arg0, arg1);
10034 case TRUNC_DIV_EXPR:
10035 case FLOOR_DIV_EXPR:
10036 /* Simplify A / (B << N) where A and B are positive and B is
10037 a power of 2, to A >> (N + log2(B)). */
10038 strict_overflow_p = false;
10039 if (TREE_CODE (arg1) == LSHIFT_EXPR
10040 && (TYPE_UNSIGNED (type)
10041 || tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p)))
10043 tree sval = TREE_OPERAND (arg1, 0);
10044 if (integer_pow2p (sval) && tree_int_cst_sgn (sval) > 0)
10046 tree sh_cnt = TREE_OPERAND (arg1, 1);
10047 unsigned long pow2 = exact_log2 (TREE_INT_CST_LOW (sval));
10049 if (strict_overflow_p)
10050 fold_overflow_warning (("assuming signed overflow does not "
10051 "occur when simplifying A / (B << N)"),
10052 WARN_STRICT_OVERFLOW_MISC);
10054 sh_cnt = fold_build2 (PLUS_EXPR, TREE_TYPE (sh_cnt),
10055 sh_cnt, build_int_cst (NULL_TREE, pow2));
10056 return fold_build2 (RSHIFT_EXPR, type,
10057 fold_convert (type, arg0), sh_cnt);
10062 case ROUND_DIV_EXPR:
10063 case CEIL_DIV_EXPR:
10064 case EXACT_DIV_EXPR:
10065 if (integer_onep (arg1))
10066 return non_lvalue (fold_convert (type, arg0));
10067 if (integer_zerop (arg1))
10069 /* X / -1 is -X. */
10070 if (!TYPE_UNSIGNED (type)
10071 && TREE_CODE (arg1) == INTEGER_CST
10072 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
10073 && TREE_INT_CST_HIGH (arg1) == -1)
10074 return fold_convert (type, negate_expr (arg0));
10076 /* Convert -A / -B to A / B when the type is signed and overflow is
10078 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
10079 && TREE_CODE (arg0) == NEGATE_EXPR
10080 && negate_expr_p (arg1))
10082 if (INTEGRAL_TYPE_P (type))
10083 fold_overflow_warning (("assuming signed overflow does not occur "
10084 "when distributing negation across "
10086 WARN_STRICT_OVERFLOW_MISC);
10087 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
10088 negate_expr (arg1));
10090 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
10091 && TREE_CODE (arg1) == NEGATE_EXPR
10092 && negate_expr_p (arg0))
10094 if (INTEGRAL_TYPE_P (type))
10095 fold_overflow_warning (("assuming signed overflow does not occur "
10096 "when distributing negation across "
10098 WARN_STRICT_OVERFLOW_MISC);
10099 return fold_build2 (code, type, negate_expr (arg0),
10100 TREE_OPERAND (arg1, 0));
10103 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
10104 operation, EXACT_DIV_EXPR.
10106 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
10107 At one time others generated faster code, it's not clear if they do
10108 after the last round to changes to the DIV code in expmed.c. */
10109 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
10110 && multiple_of_p (type, arg0, arg1))
10111 return fold_build2 (EXACT_DIV_EXPR, type, arg0, arg1);
10113 strict_overflow_p = false;
10114 if (TREE_CODE (arg1) == INTEGER_CST
10115 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
10116 &strict_overflow_p)))
10118 if (strict_overflow_p)
10119 fold_overflow_warning (("assuming signed overflow does not occur "
10120 "when simplifying division"),
10121 WARN_STRICT_OVERFLOW_MISC);
10122 return fold_convert (type, tem);
10127 case CEIL_MOD_EXPR:
10128 case FLOOR_MOD_EXPR:
10129 case ROUND_MOD_EXPR:
10130 case TRUNC_MOD_EXPR:
10131 /* X % 1 is always zero, but be sure to preserve any side
10133 if (integer_onep (arg1))
10134 return omit_one_operand (type, integer_zero_node, arg0);
10136 /* X % 0, return X % 0 unchanged so that we can get the
10137 proper warnings and errors. */
10138 if (integer_zerop (arg1))
10141 /* 0 % X is always zero, but be sure to preserve any side
10142 effects in X. Place this after checking for X == 0. */
10143 if (integer_zerop (arg0))
10144 return omit_one_operand (type, integer_zero_node, arg1);
10146 /* X % -1 is zero. */
10147 if (!TYPE_UNSIGNED (type)
10148 && TREE_CODE (arg1) == INTEGER_CST
10149 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
10150 && TREE_INT_CST_HIGH (arg1) == -1)
10151 return omit_one_operand (type, integer_zero_node, arg0);
10153 /* Optimize TRUNC_MOD_EXPR by a power of two into a BIT_AND_EXPR,
10154 i.e. "X % C" into "X & (C - 1)", if X and C are positive. */
10155 strict_overflow_p = false;
10156 if ((code == TRUNC_MOD_EXPR || code == FLOOR_MOD_EXPR)
10157 && (TYPE_UNSIGNED (type)
10158 || tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p)))
10161 /* Also optimize A % (C << N) where C is a power of 2,
10162 to A & ((C << N) - 1). */
10163 if (TREE_CODE (arg1) == LSHIFT_EXPR)
10164 c = TREE_OPERAND (arg1, 0);
10166 if (integer_pow2p (c) && tree_int_cst_sgn (c) > 0)
10168 tree mask = fold_build2 (MINUS_EXPR, TREE_TYPE (arg1),
10169 arg1, integer_one_node);
10170 if (strict_overflow_p)
10171 fold_overflow_warning (("assuming signed overflow does not "
10172 "occur when simplifying "
10173 "X % (power of two)"),
10174 WARN_STRICT_OVERFLOW_MISC);
10175 return fold_build2 (BIT_AND_EXPR, type,
10176 fold_convert (type, arg0),
10177 fold_convert (type, mask));
10181 /* X % -C is the same as X % C. */
10182 if (code == TRUNC_MOD_EXPR
10183 && !TYPE_UNSIGNED (type)
10184 && TREE_CODE (arg1) == INTEGER_CST
10185 && !TREE_CONSTANT_OVERFLOW (arg1)
10186 && TREE_INT_CST_HIGH (arg1) < 0
10187 && !TYPE_OVERFLOW_TRAPS (type)
10188 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
10189 && !sign_bit_p (arg1, arg1))
10190 return fold_build2 (code, type, fold_convert (type, arg0),
10191 fold_convert (type, negate_expr (arg1)));
10193 /* X % -Y is the same as X % Y. */
10194 if (code == TRUNC_MOD_EXPR
10195 && !TYPE_UNSIGNED (type)
10196 && TREE_CODE (arg1) == NEGATE_EXPR
10197 && !TYPE_OVERFLOW_TRAPS (type))
10198 return fold_build2 (code, type, fold_convert (type, arg0),
10199 fold_convert (type, TREE_OPERAND (arg1, 0)));
10201 if (TREE_CODE (arg1) == INTEGER_CST
10202 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
10203 &strict_overflow_p)))
10205 if (strict_overflow_p)
10206 fold_overflow_warning (("assuming signed overflow does not occur "
10207 "when simplifying modulos"),
10208 WARN_STRICT_OVERFLOW_MISC);
10209 return fold_convert (type, tem);
10216 if (integer_all_onesp (arg0))
10217 return omit_one_operand (type, arg0, arg1);
10221 /* Optimize -1 >> x for arithmetic right shifts. */
10222 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type))
10223 return omit_one_operand (type, arg0, arg1);
10224 /* ... fall through ... */
10228 if (integer_zerop (arg1))
10229 return non_lvalue (fold_convert (type, arg0));
10230 if (integer_zerop (arg0))
10231 return omit_one_operand (type, arg0, arg1);
10233 /* Since negative shift count is not well-defined,
10234 don't try to compute it in the compiler. */
10235 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
10238 /* Turn (a OP c1) OP c2 into a OP (c1+c2). */
10239 if (TREE_CODE (op0) == code && host_integerp (arg1, false)
10240 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
10241 && host_integerp (TREE_OPERAND (arg0, 1), false)
10242 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
10244 HOST_WIDE_INT low = (TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1))
10245 + TREE_INT_CST_LOW (arg1));
10247 /* Deal with a OP (c1 + c2) being undefined but (a OP c1) OP c2
10248 being well defined. */
10249 if (low >= TYPE_PRECISION (type))
10251 if (code == LROTATE_EXPR || code == RROTATE_EXPR)
10252 low = low % TYPE_PRECISION (type);
10253 else if (TYPE_UNSIGNED (type) || code == LSHIFT_EXPR)
10254 return build_int_cst (type, 0);
10256 low = TYPE_PRECISION (type) - 1;
10259 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
10260 build_int_cst (type, low));
10263 /* Transform (x >> c) << c into x & (-1<<c), or transform (x << c) >> c
10264 into x & ((unsigned)-1 >> c) for unsigned types. */
10265 if (((code == LSHIFT_EXPR && TREE_CODE (arg0) == RSHIFT_EXPR)
10266 || (TYPE_UNSIGNED (type)
10267 && code == RSHIFT_EXPR && TREE_CODE (arg0) == LSHIFT_EXPR))
10268 && host_integerp (arg1, false)
10269 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
10270 && host_integerp (TREE_OPERAND (arg0, 1), false)
10271 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
10273 HOST_WIDE_INT low0 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
10274 HOST_WIDE_INT low1 = TREE_INT_CST_LOW (arg1);
10280 arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
10282 lshift = build_int_cst (type, -1);
10283 lshift = int_const_binop (code, lshift, arg1, 0);
10285 return fold_build2 (BIT_AND_EXPR, type, arg00, lshift);
10289 /* Rewrite an LROTATE_EXPR by a constant into an
10290 RROTATE_EXPR by a new constant. */
10291 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
10293 tree tem = build_int_cst (NULL_TREE,
10294 GET_MODE_BITSIZE (TYPE_MODE (type)));
10295 tem = fold_convert (TREE_TYPE (arg1), tem);
10296 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
10297 return fold_build2 (RROTATE_EXPR, type, arg0, tem);
10300 /* If we have a rotate of a bit operation with the rotate count and
10301 the second operand of the bit operation both constant,
10302 permute the two operations. */
10303 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
10304 && (TREE_CODE (arg0) == BIT_AND_EXPR
10305 || TREE_CODE (arg0) == BIT_IOR_EXPR
10306 || TREE_CODE (arg0) == BIT_XOR_EXPR)
10307 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10308 return fold_build2 (TREE_CODE (arg0), type,
10309 fold_build2 (code, type,
10310 TREE_OPERAND (arg0, 0), arg1),
10311 fold_build2 (code, type,
10312 TREE_OPERAND (arg0, 1), arg1));
10314 /* Two consecutive rotates adding up to the width of the mode can
10316 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
10317 && TREE_CODE (arg0) == RROTATE_EXPR
10318 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
10319 && TREE_INT_CST_HIGH (arg1) == 0
10320 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
10321 && ((TREE_INT_CST_LOW (arg1)
10322 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
10323 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
10324 return TREE_OPERAND (arg0, 0);
10329 if (operand_equal_p (arg0, arg1, 0))
10330 return omit_one_operand (type, arg0, arg1);
10331 if (INTEGRAL_TYPE_P (type)
10332 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
10333 return omit_one_operand (type, arg1, arg0);
10334 tem = fold_minmax (MIN_EXPR, type, arg0, arg1);
10340 if (operand_equal_p (arg0, arg1, 0))
10341 return omit_one_operand (type, arg0, arg1);
10342 if (INTEGRAL_TYPE_P (type)
10343 && TYPE_MAX_VALUE (type)
10344 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
10345 return omit_one_operand (type, arg1, arg0);
10346 tem = fold_minmax (MAX_EXPR, type, arg0, arg1);
10351 case TRUTH_ANDIF_EXPR:
10352 /* Note that the operands of this must be ints
10353 and their values must be 0 or 1.
10354 ("true" is a fixed value perhaps depending on the language.) */
10355 /* If first arg is constant zero, return it. */
10356 if (integer_zerop (arg0))
10357 return fold_convert (type, arg0);
10358 case TRUTH_AND_EXPR:
10359 /* If either arg is constant true, drop it. */
10360 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
10361 return non_lvalue (fold_convert (type, arg1));
10362 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
10363 /* Preserve sequence points. */
10364 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
10365 return non_lvalue (fold_convert (type, arg0));
10366 /* If second arg is constant zero, result is zero, but first arg
10367 must be evaluated. */
10368 if (integer_zerop (arg1))
10369 return omit_one_operand (type, arg1, arg0);
10370 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
10371 case will be handled here. */
10372 if (integer_zerop (arg0))
10373 return omit_one_operand (type, arg0, arg1);
10375 /* !X && X is always false. */
10376 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
10377 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10378 return omit_one_operand (type, integer_zero_node, arg1);
10379 /* X && !X is always false. */
10380 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
10381 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10382 return omit_one_operand (type, integer_zero_node, arg0);
10384 /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
10385 means A >= Y && A != MAX, but in this case we know that
10388 if (!TREE_SIDE_EFFECTS (arg0)
10389 && !TREE_SIDE_EFFECTS (arg1))
10391 tem = fold_to_nonsharp_ineq_using_bound (arg0, arg1);
10392 if (tem && !operand_equal_p (tem, arg0, 0))
10393 return fold_build2 (code, type, tem, arg1);
10395 tem = fold_to_nonsharp_ineq_using_bound (arg1, arg0);
10396 if (tem && !operand_equal_p (tem, arg1, 0))
10397 return fold_build2 (code, type, arg0, tem);
10401 /* We only do these simplifications if we are optimizing. */
10405 /* Check for things like (A || B) && (A || C). We can convert this
10406 to A || (B && C). Note that either operator can be any of the four
10407 truth and/or operations and the transformation will still be
10408 valid. Also note that we only care about order for the
10409 ANDIF and ORIF operators. If B contains side effects, this
10410 might change the truth-value of A. */
10411 if (TREE_CODE (arg0) == TREE_CODE (arg1)
10412 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
10413 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
10414 || TREE_CODE (arg0) == TRUTH_AND_EXPR
10415 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
10416 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
10418 tree a00 = TREE_OPERAND (arg0, 0);
10419 tree a01 = TREE_OPERAND (arg0, 1);
10420 tree a10 = TREE_OPERAND (arg1, 0);
10421 tree a11 = TREE_OPERAND (arg1, 1);
10422 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
10423 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
10424 && (code == TRUTH_AND_EXPR
10425 || code == TRUTH_OR_EXPR));
10427 if (operand_equal_p (a00, a10, 0))
10428 return fold_build2 (TREE_CODE (arg0), type, a00,
10429 fold_build2 (code, type, a01, a11));
10430 else if (commutative && operand_equal_p (a00, a11, 0))
10431 return fold_build2 (TREE_CODE (arg0), type, a00,
10432 fold_build2 (code, type, a01, a10));
10433 else if (commutative && operand_equal_p (a01, a10, 0))
10434 return fold_build2 (TREE_CODE (arg0), type, a01,
10435 fold_build2 (code, type, a00, a11));
10437 /* This case if tricky because we must either have commutative
10438 operators or else A10 must not have side-effects. */
10440 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
10441 && operand_equal_p (a01, a11, 0))
10442 return fold_build2 (TREE_CODE (arg0), type,
10443 fold_build2 (code, type, a00, a10),
10447 /* See if we can build a range comparison. */
10448 if (0 != (tem = fold_range_test (code, type, op0, op1)))
10451 /* Check for the possibility of merging component references. If our
10452 lhs is another similar operation, try to merge its rhs with our
10453 rhs. Then try to merge our lhs and rhs. */
10454 if (TREE_CODE (arg0) == code
10455 && 0 != (tem = fold_truthop (code, type,
10456 TREE_OPERAND (arg0, 1), arg1)))
10457 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
10459 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
10464 case TRUTH_ORIF_EXPR:
10465 /* Note that the operands of this must be ints
10466 and their values must be 0 or true.
10467 ("true" is a fixed value perhaps depending on the language.) */
10468 /* If first arg is constant true, return it. */
10469 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
10470 return fold_convert (type, arg0);
10471 case TRUTH_OR_EXPR:
10472 /* If either arg is constant zero, drop it. */
10473 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
10474 return non_lvalue (fold_convert (type, arg1));
10475 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
10476 /* Preserve sequence points. */
10477 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
10478 return non_lvalue (fold_convert (type, arg0));
10479 /* If second arg is constant true, result is true, but we must
10480 evaluate first arg. */
10481 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
10482 return omit_one_operand (type, arg1, arg0);
10483 /* Likewise for first arg, but note this only occurs here for
10485 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
10486 return omit_one_operand (type, arg0, arg1);
10488 /* !X || X is always true. */
10489 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
10490 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10491 return omit_one_operand (type, integer_one_node, arg1);
10492 /* X || !X is always true. */
10493 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
10494 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10495 return omit_one_operand (type, integer_one_node, arg0);
10499 case TRUTH_XOR_EXPR:
10500 /* If the second arg is constant zero, drop it. */
10501 if (integer_zerop (arg1))
10502 return non_lvalue (fold_convert (type, arg0));
10503 /* If the second arg is constant true, this is a logical inversion. */
10504 if (integer_onep (arg1))
10506 /* Only call invert_truthvalue if operand is a truth value. */
10507 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
10508 tem = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg0), arg0);
10510 tem = invert_truthvalue (arg0);
10511 return non_lvalue (fold_convert (type, tem));
10513 /* Identical arguments cancel to zero. */
10514 if (operand_equal_p (arg0, arg1, 0))
10515 return omit_one_operand (type, integer_zero_node, arg0);
10517 /* !X ^ X is always true. */
10518 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
10519 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10520 return omit_one_operand (type, integer_one_node, arg1);
10522 /* X ^ !X is always true. */
10523 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
10524 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10525 return omit_one_operand (type, integer_one_node, arg0);
10531 tem = fold_comparison (code, type, op0, op1);
10532 if (tem != NULL_TREE)
10535 /* bool_var != 0 becomes bool_var. */
10536 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
10537 && code == NE_EXPR)
10538 return non_lvalue (fold_convert (type, arg0));
10540 /* bool_var == 1 becomes bool_var. */
10541 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
10542 && code == EQ_EXPR)
10543 return non_lvalue (fold_convert (type, arg0));
10545 /* bool_var != 1 becomes !bool_var. */
10546 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
10547 && code == NE_EXPR)
10548 return fold_build1 (TRUTH_NOT_EXPR, type, arg0);
10550 /* bool_var == 0 becomes !bool_var. */
10551 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
10552 && code == EQ_EXPR)
10553 return fold_build1 (TRUTH_NOT_EXPR, type, arg0);
10555 /* ~a != C becomes a != ~C where C is a constant. Likewise for ==. */
10556 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10557 && TREE_CODE (arg1) == INTEGER_CST)
10559 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
10560 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
10561 fold_build1 (BIT_NOT_EXPR, cmp_type,
10562 fold_convert (cmp_type, arg1)));
10565 /* If this is an equality comparison of the address of a non-weak
10566 object against zero, then we know the result. */
10567 if (TREE_CODE (arg0) == ADDR_EXPR
10568 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg0, 0))
10569 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
10570 && integer_zerop (arg1))
10571 return constant_boolean_node (code != EQ_EXPR, type);
10573 /* If this is an equality comparison of the address of two non-weak,
10574 unaliased symbols neither of which are extern (since we do not
10575 have access to attributes for externs), then we know the result. */
10576 if (TREE_CODE (arg0) == ADDR_EXPR
10577 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg0, 0))
10578 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
10579 && ! lookup_attribute ("alias",
10580 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
10581 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
10582 && TREE_CODE (arg1) == ADDR_EXPR
10583 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg1, 0))
10584 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
10585 && ! lookup_attribute ("alias",
10586 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
10587 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
10589 /* We know that we're looking at the address of two
10590 non-weak, unaliased, static _DECL nodes.
10592 It is both wasteful and incorrect to call operand_equal_p
10593 to compare the two ADDR_EXPR nodes. It is wasteful in that
10594 all we need to do is test pointer equality for the arguments
10595 to the two ADDR_EXPR nodes. It is incorrect to use
10596 operand_equal_p as that function is NOT equivalent to a
10597 C equality test. It can in fact return false for two
10598 objects which would test as equal using the C equality
10600 bool equal = TREE_OPERAND (arg0, 0) == TREE_OPERAND (arg1, 0);
10601 return constant_boolean_node (equal
10602 ? code == EQ_EXPR : code != EQ_EXPR,
10606 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
10607 a MINUS_EXPR of a constant, we can convert it into a comparison with
10608 a revised constant as long as no overflow occurs. */
10609 if (TREE_CODE (arg1) == INTEGER_CST
10610 && (TREE_CODE (arg0) == PLUS_EXPR
10611 || TREE_CODE (arg0) == MINUS_EXPR)
10612 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
10613 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
10614 ? MINUS_EXPR : PLUS_EXPR,
10615 fold_convert (TREE_TYPE (arg0), arg1),
10616 TREE_OPERAND (arg0, 1), 0))
10617 && ! TREE_CONSTANT_OVERFLOW (tem))
10618 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
10620 /* Similarly for a NEGATE_EXPR. */
10621 if (TREE_CODE (arg0) == NEGATE_EXPR
10622 && TREE_CODE (arg1) == INTEGER_CST
10623 && 0 != (tem = negate_expr (arg1))
10624 && TREE_CODE (tem) == INTEGER_CST
10625 && ! TREE_CONSTANT_OVERFLOW (tem))
10626 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
10628 /* If we have X - Y == 0, we can convert that to X == Y and similarly
10629 for !=. Don't do this for ordered comparisons due to overflow. */
10630 if (TREE_CODE (arg0) == MINUS_EXPR
10631 && integer_zerop (arg1))
10632 return fold_build2 (code, type,
10633 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
10635 /* Convert ABS_EXPR<x> == 0 or ABS_EXPR<x> != 0 to x == 0 or x != 0. */
10636 if (TREE_CODE (arg0) == ABS_EXPR
10637 && (integer_zerop (arg1) || real_zerop (arg1)))
10638 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), arg1);
10640 /* If this is an EQ or NE comparison with zero and ARG0 is
10641 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
10642 two operations, but the latter can be done in one less insn
10643 on machines that have only two-operand insns or on which a
10644 constant cannot be the first operand. */
10645 if (TREE_CODE (arg0) == BIT_AND_EXPR
10646 && integer_zerop (arg1))
10648 tree arg00 = TREE_OPERAND (arg0, 0);
10649 tree arg01 = TREE_OPERAND (arg0, 1);
10650 if (TREE_CODE (arg00) == LSHIFT_EXPR
10651 && integer_onep (TREE_OPERAND (arg00, 0)))
10653 tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
10654 arg01, TREE_OPERAND (arg00, 1));
10655 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
10656 build_int_cst (TREE_TYPE (arg0), 1));
10657 return fold_build2 (code, type,
10658 fold_convert (TREE_TYPE (arg1), tem), arg1);
10660 else if (TREE_CODE (arg01) == LSHIFT_EXPR
10661 && integer_onep (TREE_OPERAND (arg01, 0)))
10663 tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
10664 arg00, TREE_OPERAND (arg01, 1));
10665 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
10666 build_int_cst (TREE_TYPE (arg0), 1));
10667 return fold_build2 (code, type,
10668 fold_convert (TREE_TYPE (arg1), tem), arg1);
10672 /* If this is an NE or EQ comparison of zero against the result of a
10673 signed MOD operation whose second operand is a power of 2, make
10674 the MOD operation unsigned since it is simpler and equivalent. */
10675 if (integer_zerop (arg1)
10676 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
10677 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
10678 || TREE_CODE (arg0) == CEIL_MOD_EXPR
10679 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
10680 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
10681 && integer_pow2p (TREE_OPERAND (arg0, 1)))
10683 tree newtype = lang_hooks.types.unsigned_type (TREE_TYPE (arg0));
10684 tree newmod = fold_build2 (TREE_CODE (arg0), newtype,
10685 fold_convert (newtype,
10686 TREE_OPERAND (arg0, 0)),
10687 fold_convert (newtype,
10688 TREE_OPERAND (arg0, 1)));
10690 return fold_build2 (code, type, newmod,
10691 fold_convert (newtype, arg1));
10694 /* Fold ((X >> C1) & C2) == 0 and ((X >> C1) & C2) != 0 where
10695 C1 is a valid shift constant, and C2 is a power of two, i.e.
10697 if (TREE_CODE (arg0) == BIT_AND_EXPR
10698 && TREE_CODE (TREE_OPERAND (arg0, 0)) == RSHIFT_EXPR
10699 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1))
10701 && integer_pow2p (TREE_OPERAND (arg0, 1))
10702 && integer_zerop (arg1))
10704 tree itype = TREE_TYPE (arg0);
10705 unsigned HOST_WIDE_INT prec = TYPE_PRECISION (itype);
10706 tree arg001 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 1);
10708 /* Check for a valid shift count. */
10709 if (TREE_INT_CST_HIGH (arg001) == 0
10710 && TREE_INT_CST_LOW (arg001) < prec)
10712 tree arg01 = TREE_OPERAND (arg0, 1);
10713 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
10714 unsigned HOST_WIDE_INT log2 = tree_log2 (arg01);
10715 /* If (C2 << C1) doesn't overflow, then ((X >> C1) & C2) != 0
10716 can be rewritten as (X & (C2 << C1)) != 0. */
10717 if ((log2 + TREE_INT_CST_LOW (arg001)) < prec)
10719 tem = fold_build2 (LSHIFT_EXPR, itype, arg01, arg001);
10720 tem = fold_build2 (BIT_AND_EXPR, itype, arg000, tem);
10721 return fold_build2 (code, type, tem, arg1);
10723 /* Otherwise, for signed (arithmetic) shifts,
10724 ((X >> C1) & C2) != 0 is rewritten as X < 0, and
10725 ((X >> C1) & C2) == 0 is rewritten as X >= 0. */
10726 else if (!TYPE_UNSIGNED (itype))
10727 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR, type,
10728 arg000, build_int_cst (itype, 0));
10729 /* Otherwise, of unsigned (logical) shifts,
10730 ((X >> C1) & C2) != 0 is rewritten as (X,false), and
10731 ((X >> C1) & C2) == 0 is rewritten as (X,true). */
10733 return omit_one_operand (type,
10734 code == EQ_EXPR ? integer_one_node
10735 : integer_zero_node,
10740 /* If this is an NE comparison of zero with an AND of one, remove the
10741 comparison since the AND will give the correct value. */
10742 if (code == NE_EXPR
10743 && integer_zerop (arg1)
10744 && TREE_CODE (arg0) == BIT_AND_EXPR
10745 && integer_onep (TREE_OPERAND (arg0, 1)))
10746 return fold_convert (type, arg0);
10748 /* If we have (A & C) == C where C is a power of 2, convert this into
10749 (A & C) != 0. Similarly for NE_EXPR. */
10750 if (TREE_CODE (arg0) == BIT_AND_EXPR
10751 && integer_pow2p (TREE_OPERAND (arg0, 1))
10752 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10753 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
10754 arg0, fold_convert (TREE_TYPE (arg0),
10755 integer_zero_node));
10757 /* If we have (A & C) != 0 or (A & C) == 0 and C is the sign
10758 bit, then fold the expression into A < 0 or A >= 0. */
10759 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1, type);
10763 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
10764 Similarly for NE_EXPR. */
10765 if (TREE_CODE (arg0) == BIT_AND_EXPR
10766 && TREE_CODE (arg1) == INTEGER_CST
10767 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10769 tree notc = fold_build1 (BIT_NOT_EXPR,
10770 TREE_TYPE (TREE_OPERAND (arg0, 1)),
10771 TREE_OPERAND (arg0, 1));
10772 tree dandnotc = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
10774 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
10775 if (integer_nonzerop (dandnotc))
10776 return omit_one_operand (type, rslt, arg0);
10779 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
10780 Similarly for NE_EXPR. */
10781 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10782 && TREE_CODE (arg1) == INTEGER_CST
10783 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10785 tree notd = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1);
10786 tree candnotd = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
10787 TREE_OPERAND (arg0, 1), notd);
10788 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
10789 if (integer_nonzerop (candnotd))
10790 return omit_one_operand (type, rslt, arg0);
10793 /* If this is a comparison of a field, we may be able to simplify it. */
10794 if (((TREE_CODE (arg0) == COMPONENT_REF
10795 && lang_hooks.can_use_bit_fields_p ())
10796 || TREE_CODE (arg0) == BIT_FIELD_REF)
10797 /* Handle the constant case even without -O
10798 to make sure the warnings are given. */
10799 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
10801 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
10806 /* Optimize comparisons of strlen vs zero to a compare of the
10807 first character of the string vs zero. To wit,
10808 strlen(ptr) == 0 => *ptr == 0
10809 strlen(ptr) != 0 => *ptr != 0
10810 Other cases should reduce to one of these two (or a constant)
10811 due to the return value of strlen being unsigned. */
10812 if (TREE_CODE (arg0) == CALL_EXPR
10813 && integer_zerop (arg1))
10815 tree fndecl = get_callee_fndecl (arg0);
10819 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
10820 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
10821 && (arglist = TREE_OPERAND (arg0, 1))
10822 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
10823 && ! TREE_CHAIN (arglist))
10825 tree iref = build_fold_indirect_ref (TREE_VALUE (arglist));
10826 return fold_build2 (code, type, iref,
10827 build_int_cst (TREE_TYPE (iref), 0));
10831 /* Fold (X >> C) != 0 into X < 0 if C is one less than the width
10832 of X. Similarly fold (X >> C) == 0 into X >= 0. */
10833 if (TREE_CODE (arg0) == RSHIFT_EXPR
10834 && integer_zerop (arg1)
10835 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10837 tree arg00 = TREE_OPERAND (arg0, 0);
10838 tree arg01 = TREE_OPERAND (arg0, 1);
10839 tree itype = TREE_TYPE (arg00);
10840 if (TREE_INT_CST_HIGH (arg01) == 0
10841 && TREE_INT_CST_LOW (arg01)
10842 == (unsigned HOST_WIDE_INT) (TYPE_PRECISION (itype) - 1))
10844 if (TYPE_UNSIGNED (itype))
10846 itype = lang_hooks.types.signed_type (itype);
10847 arg00 = fold_convert (itype, arg00);
10849 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
10850 type, arg00, build_int_cst (itype, 0));
10854 /* (X ^ Y) == 0 becomes X == Y, and (X ^ Y) != 0 becomes X != Y. */
10855 if (integer_zerop (arg1)
10856 && TREE_CODE (arg0) == BIT_XOR_EXPR)
10857 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
10858 TREE_OPERAND (arg0, 1));
10860 /* (X ^ Y) == Y becomes X == 0. We know that Y has no side-effects. */
10861 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10862 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10863 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
10864 build_int_cst (TREE_TYPE (arg1), 0));
10865 /* Likewise (X ^ Y) == X becomes Y == 0. X has no side-effects. */
10866 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10867 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10868 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10869 return fold_build2 (code, type, TREE_OPERAND (arg0, 1),
10870 build_int_cst (TREE_TYPE (arg1), 0));
10872 /* (X ^ C1) op C2 can be rewritten as X op (C1 ^ C2). */
10873 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10874 && TREE_CODE (arg1) == INTEGER_CST
10875 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10876 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
10877 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg1),
10878 TREE_OPERAND (arg0, 1), arg1));
10880 /* Fold (~X & C) == 0 into (X & C) != 0 and (~X & C) != 0 into
10881 (X & C) == 0 when C is a single bit. */
10882 if (TREE_CODE (arg0) == BIT_AND_EXPR
10883 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_NOT_EXPR
10884 && integer_zerop (arg1)
10885 && integer_pow2p (TREE_OPERAND (arg0, 1)))
10887 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
10888 TREE_OPERAND (TREE_OPERAND (arg0, 0), 0),
10889 TREE_OPERAND (arg0, 1));
10890 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR,
10894 /* Fold ((X & C) ^ C) eq/ne 0 into (X & C) ne/eq 0, when the
10895 constant C is a power of two, i.e. a single bit. */
10896 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10897 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
10898 && integer_zerop (arg1)
10899 && integer_pow2p (TREE_OPERAND (arg0, 1))
10900 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
10901 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
10903 tree arg00 = TREE_OPERAND (arg0, 0);
10904 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
10905 arg00, build_int_cst (TREE_TYPE (arg00), 0));
10908 /* Likewise, fold ((X ^ C) & C) eq/ne 0 into (X & C) ne/eq 0,
10909 when is C is a power of two, i.e. a single bit. */
10910 if (TREE_CODE (arg0) == BIT_AND_EXPR
10911 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_XOR_EXPR
10912 && integer_zerop (arg1)
10913 && integer_pow2p (TREE_OPERAND (arg0, 1))
10914 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
10915 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
10917 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
10918 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg000),
10919 arg000, TREE_OPERAND (arg0, 1));
10920 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
10921 tem, build_int_cst (TREE_TYPE (tem), 0));
10924 if (integer_zerop (arg1)
10925 && tree_expr_nonzero_p (arg0))
10927 tree res = constant_boolean_node (code==NE_EXPR, type);
10928 return omit_one_operand (type, res, arg0);
10936 tem = fold_comparison (code, type, op0, op1);
10937 if (tem != NULL_TREE)
10940 /* Transform comparisons of the form X +- C CMP X. */
10941 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
10942 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10943 && ((TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
10944 && !HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0))))
10945 || (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
10946 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))))
10948 tree arg01 = TREE_OPERAND (arg0, 1);
10949 enum tree_code code0 = TREE_CODE (arg0);
10952 if (TREE_CODE (arg01) == REAL_CST)
10953 is_positive = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg01)) ? -1 : 1;
10955 is_positive = tree_int_cst_sgn (arg01);
10957 /* (X - c) > X becomes false. */
10958 if (code == GT_EXPR
10959 && ((code0 == MINUS_EXPR && is_positive >= 0)
10960 || (code0 == PLUS_EXPR && is_positive <= 0)))
10962 if (TREE_CODE (arg01) == INTEGER_CST
10963 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
10964 fold_overflow_warning (("assuming signed overflow does not "
10965 "occur when assuming that (X - c) > X "
10966 "is always false"),
10967 WARN_STRICT_OVERFLOW_ALL);
10968 return constant_boolean_node (0, type);
10971 /* Likewise (X + c) < X becomes false. */
10972 if (code == LT_EXPR
10973 && ((code0 == PLUS_EXPR && is_positive >= 0)
10974 || (code0 == MINUS_EXPR && is_positive <= 0)))
10976 if (TREE_CODE (arg01) == INTEGER_CST
10977 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
10978 fold_overflow_warning (("assuming signed overflow does not "
10979 "occur when assuming that "
10980 "(X + c) < X is always false"),
10981 WARN_STRICT_OVERFLOW_ALL);
10982 return constant_boolean_node (0, type);
10985 /* Convert (X - c) <= X to true. */
10986 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
10988 && ((code0 == MINUS_EXPR && is_positive >= 0)
10989 || (code0 == PLUS_EXPR && is_positive <= 0)))
10991 if (TREE_CODE (arg01) == INTEGER_CST
10992 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
10993 fold_overflow_warning (("assuming signed overflow does not "
10994 "occur when assuming that "
10995 "(X - c) <= X is always true"),
10996 WARN_STRICT_OVERFLOW_ALL);
10997 return constant_boolean_node (1, type);
11000 /* Convert (X + c) >= X to true. */
11001 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
11003 && ((code0 == PLUS_EXPR && is_positive >= 0)
11004 || (code0 == MINUS_EXPR && is_positive <= 0)))
11006 if (TREE_CODE (arg01) == INTEGER_CST
11007 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
11008 fold_overflow_warning (("assuming signed overflow does not "
11009 "occur when assuming that "
11010 "(X + c) >= X is always true"),
11011 WARN_STRICT_OVERFLOW_ALL);
11012 return constant_boolean_node (1, type);
11015 if (TREE_CODE (arg01) == INTEGER_CST)
11017 /* Convert X + c > X and X - c < X to true for integers. */
11018 if (code == GT_EXPR
11019 && ((code0 == PLUS_EXPR && is_positive > 0)
11020 || (code0 == MINUS_EXPR && is_positive < 0)))
11022 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
11023 fold_overflow_warning (("assuming signed overflow does "
11024 "not occur when assuming that "
11025 "(X + c) > X is always true"),
11026 WARN_STRICT_OVERFLOW_ALL);
11027 return constant_boolean_node (1, type);
11030 if (code == LT_EXPR
11031 && ((code0 == MINUS_EXPR && is_positive > 0)
11032 || (code0 == PLUS_EXPR && is_positive < 0)))
11034 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
11035 fold_overflow_warning (("assuming signed overflow does "
11036 "not occur when assuming that "
11037 "(X - c) < X is always true"),
11038 WARN_STRICT_OVERFLOW_ALL);
11039 return constant_boolean_node (1, type);
11042 /* Convert X + c <= X and X - c >= X to false for integers. */
11043 if (code == LE_EXPR
11044 && ((code0 == PLUS_EXPR && is_positive > 0)
11045 || (code0 == MINUS_EXPR && is_positive < 0)))
11047 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
11048 fold_overflow_warning (("assuming signed overflow does "
11049 "not occur when assuming that "
11050 "(X + c) <= X is always false"),
11051 WARN_STRICT_OVERFLOW_ALL);
11052 return constant_boolean_node (0, type);
11055 if (code == GE_EXPR
11056 && ((code0 == MINUS_EXPR && is_positive > 0)
11057 || (code0 == PLUS_EXPR && is_positive < 0)))
11059 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
11060 fold_overflow_warning (("assuming signed overflow does "
11061 "not occur when assuming that "
11062 "(X - c) >= X is always true"),
11063 WARN_STRICT_OVERFLOW_ALL);
11064 return constant_boolean_node (0, type);
11069 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
11070 This transformation affects the cases which are handled in later
11071 optimizations involving comparisons with non-negative constants. */
11072 if (TREE_CODE (arg1) == INTEGER_CST
11073 && TREE_CODE (arg0) != INTEGER_CST
11074 && tree_int_cst_sgn (arg1) > 0)
11076 if (code == GE_EXPR)
11078 arg1 = const_binop (MINUS_EXPR, arg1,
11079 build_int_cst (TREE_TYPE (arg1), 1), 0);
11080 return fold_build2 (GT_EXPR, type, arg0,
11081 fold_convert (TREE_TYPE (arg0), arg1));
11083 if (code == LT_EXPR)
11085 arg1 = const_binop (MINUS_EXPR, arg1,
11086 build_int_cst (TREE_TYPE (arg1), 1), 0);
11087 return fold_build2 (LE_EXPR, type, arg0,
11088 fold_convert (TREE_TYPE (arg0), arg1));
11092 /* Comparisons with the highest or lowest possible integer of
11093 the specified size will have known values. */
11095 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
11097 if (TREE_CODE (arg1) == INTEGER_CST
11098 && ! TREE_CONSTANT_OVERFLOW (arg1)
11099 && width <= 2 * HOST_BITS_PER_WIDE_INT
11100 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
11101 || POINTER_TYPE_P (TREE_TYPE (arg1))))
11103 HOST_WIDE_INT signed_max_hi;
11104 unsigned HOST_WIDE_INT signed_max_lo;
11105 unsigned HOST_WIDE_INT max_hi, max_lo, min_hi, min_lo;
11107 if (width <= HOST_BITS_PER_WIDE_INT)
11109 signed_max_lo = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
11114 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
11116 max_lo = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
11122 max_lo = signed_max_lo;
11123 min_lo = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
11129 width -= HOST_BITS_PER_WIDE_INT;
11130 signed_max_lo = -1;
11131 signed_max_hi = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
11136 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
11138 max_hi = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
11143 max_hi = signed_max_hi;
11144 min_hi = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
11148 if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1) == max_hi
11149 && TREE_INT_CST_LOW (arg1) == max_lo)
11153 return omit_one_operand (type, integer_zero_node, arg0);
11156 return fold_build2 (EQ_EXPR, type, op0, op1);
11159 return omit_one_operand (type, integer_one_node, arg0);
11162 return fold_build2 (NE_EXPR, type, op0, op1);
11164 /* The GE_EXPR and LT_EXPR cases above are not normally
11165 reached because of previous transformations. */
11170 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
11172 && TREE_INT_CST_LOW (arg1) == max_lo - 1)
11176 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
11177 return fold_build2 (EQ_EXPR, type,
11178 fold_convert (TREE_TYPE (arg1), arg0),
11181 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
11182 return fold_build2 (NE_EXPR, type,
11183 fold_convert (TREE_TYPE (arg1), arg0),
11188 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
11190 && TREE_INT_CST_LOW (arg1) == min_lo)
11194 return omit_one_operand (type, integer_zero_node, arg0);
11197 return fold_build2 (EQ_EXPR, type, op0, op1);
11200 return omit_one_operand (type, integer_one_node, arg0);
11203 return fold_build2 (NE_EXPR, type, op0, op1);
11208 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
11210 && TREE_INT_CST_LOW (arg1) == min_lo + 1)
11214 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
11215 return fold_build2 (NE_EXPR, type,
11216 fold_convert (TREE_TYPE (arg1), arg0),
11219 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
11220 return fold_build2 (EQ_EXPR, type,
11221 fold_convert (TREE_TYPE (arg1), arg0),
11227 else if (!in_gimple_form
11228 && TREE_INT_CST_HIGH (arg1) == signed_max_hi
11229 && TREE_INT_CST_LOW (arg1) == signed_max_lo
11230 && TYPE_UNSIGNED (TREE_TYPE (arg1))
11231 /* signed_type does not work on pointer types. */
11232 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
11234 /* The following case also applies to X < signed_max+1
11235 and X >= signed_max+1 because previous transformations. */
11236 if (code == LE_EXPR || code == GT_EXPR)
11239 st = lang_hooks.types.signed_type (TREE_TYPE (arg1));
11240 return fold_build2 (code == LE_EXPR ? GE_EXPR : LT_EXPR,
11241 type, fold_convert (st, arg0),
11242 build_int_cst (st, 0));
11248 /* If we are comparing an ABS_EXPR with a constant, we can
11249 convert all the cases into explicit comparisons, but they may
11250 well not be faster than doing the ABS and one comparison.
11251 But ABS (X) <= C is a range comparison, which becomes a subtraction
11252 and a comparison, and is probably faster. */
11253 if (code == LE_EXPR
11254 && TREE_CODE (arg1) == INTEGER_CST
11255 && TREE_CODE (arg0) == ABS_EXPR
11256 && ! TREE_SIDE_EFFECTS (arg0)
11257 && (0 != (tem = negate_expr (arg1)))
11258 && TREE_CODE (tem) == INTEGER_CST
11259 && ! TREE_CONSTANT_OVERFLOW (tem))
11260 return fold_build2 (TRUTH_ANDIF_EXPR, type,
11261 build2 (GE_EXPR, type,
11262 TREE_OPERAND (arg0, 0), tem),
11263 build2 (LE_EXPR, type,
11264 TREE_OPERAND (arg0, 0), arg1));
11266 /* Convert ABS_EXPR<x> >= 0 to true. */
11267 strict_overflow_p = false;
11268 if (code == GE_EXPR
11269 && (integer_zerop (arg1)
11270 || (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
11271 && real_zerop (arg1)))
11272 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
11274 if (strict_overflow_p)
11275 fold_overflow_warning (("assuming signed overflow does not occur "
11276 "when simplifying comparison of "
11277 "absolute value and zero"),
11278 WARN_STRICT_OVERFLOW_CONDITIONAL);
11279 return omit_one_operand (type, integer_one_node, arg0);
11282 /* Convert ABS_EXPR<x> < 0 to false. */
11283 strict_overflow_p = false;
11284 if (code == LT_EXPR
11285 && (integer_zerop (arg1) || real_zerop (arg1))
11286 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
11288 if (strict_overflow_p)
11289 fold_overflow_warning (("assuming signed overflow does not occur "
11290 "when simplifying comparison of "
11291 "absolute value and zero"),
11292 WARN_STRICT_OVERFLOW_CONDITIONAL);
11293 return omit_one_operand (type, integer_zero_node, arg0);
11296 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
11297 and similarly for >= into !=. */
11298 if ((code == LT_EXPR || code == GE_EXPR)
11299 && TYPE_UNSIGNED (TREE_TYPE (arg0))
11300 && TREE_CODE (arg1) == LSHIFT_EXPR
11301 && integer_onep (TREE_OPERAND (arg1, 0)))
11302 return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
11303 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
11304 TREE_OPERAND (arg1, 1)),
11305 build_int_cst (TREE_TYPE (arg0), 0));
11307 if ((code == LT_EXPR || code == GE_EXPR)
11308 && TYPE_UNSIGNED (TREE_TYPE (arg0))
11309 && (TREE_CODE (arg1) == NOP_EXPR
11310 || TREE_CODE (arg1) == CONVERT_EXPR)
11311 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
11312 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
11314 build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
11315 fold_convert (TREE_TYPE (arg0),
11316 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
11317 TREE_OPERAND (TREE_OPERAND (arg1, 0),
11319 build_int_cst (TREE_TYPE (arg0), 0));
11323 case UNORDERED_EXPR:
11331 if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
11333 t1 = fold_relational_const (code, type, arg0, arg1);
11334 if (t1 != NULL_TREE)
11338 /* If the first operand is NaN, the result is constant. */
11339 if (TREE_CODE (arg0) == REAL_CST
11340 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
11341 && (code != LTGT_EXPR || ! flag_trapping_math))
11343 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
11344 ? integer_zero_node
11345 : integer_one_node;
11346 return omit_one_operand (type, t1, arg1);
11349 /* If the second operand is NaN, the result is constant. */
11350 if (TREE_CODE (arg1) == REAL_CST
11351 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
11352 && (code != LTGT_EXPR || ! flag_trapping_math))
11354 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
11355 ? integer_zero_node
11356 : integer_one_node;
11357 return omit_one_operand (type, t1, arg0);
11360 /* Simplify unordered comparison of something with itself. */
11361 if ((code == UNLE_EXPR || code == UNGE_EXPR || code == UNEQ_EXPR)
11362 && operand_equal_p (arg0, arg1, 0))
11363 return constant_boolean_node (1, type);
11365 if (code == LTGT_EXPR
11366 && !flag_trapping_math
11367 && operand_equal_p (arg0, arg1, 0))
11368 return constant_boolean_node (0, type);
11370 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
11372 tree targ0 = strip_float_extensions (arg0);
11373 tree targ1 = strip_float_extensions (arg1);
11374 tree newtype = TREE_TYPE (targ0);
11376 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
11377 newtype = TREE_TYPE (targ1);
11379 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
11380 return fold_build2 (code, type, fold_convert (newtype, targ0),
11381 fold_convert (newtype, targ1));
11386 case COMPOUND_EXPR:
11387 /* When pedantic, a compound expression can be neither an lvalue
11388 nor an integer constant expression. */
11389 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
11391 /* Don't let (0, 0) be null pointer constant. */
11392 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
11393 : fold_convert (type, arg1);
11394 return pedantic_non_lvalue (tem);
11397 if ((TREE_CODE (arg0) == REAL_CST
11398 && TREE_CODE (arg1) == REAL_CST)
11399 || (TREE_CODE (arg0) == INTEGER_CST
11400 && TREE_CODE (arg1) == INTEGER_CST))
11401 return build_complex (type, arg0, arg1);
11405 /* An ASSERT_EXPR should never be passed to fold_binary. */
11406 gcc_unreachable ();
11410 } /* switch (code) */
11413 /* Callback for walk_tree, looking for LABEL_EXPR.
11414 Returns tree TP if it is LABEL_EXPR. Otherwise it returns NULL_TREE.
11415 Do not check the sub-tree of GOTO_EXPR. */
11418 contains_label_1 (tree *tp,
11419 int *walk_subtrees,
11420 void *data ATTRIBUTE_UNUSED)
11422 switch (TREE_CODE (*tp))
11427 *walk_subtrees = 0;
11434 /* Checks whether the sub-tree ST contains a label LABEL_EXPR which is
11435 accessible from outside the sub-tree. Returns NULL_TREE if no
11436 addressable label is found. */
11439 contains_label_p (tree st)
11441 return (walk_tree (&st, contains_label_1 , NULL, NULL) != NULL_TREE);
11444 /* Fold a ternary expression of code CODE and type TYPE with operands
11445 OP0, OP1, and OP2. Return the folded expression if folding is
11446 successful. Otherwise, return NULL_TREE. */
11449 fold_ternary (enum tree_code code, tree type, tree op0, tree op1, tree op2)
11452 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
11453 enum tree_code_class kind = TREE_CODE_CLASS (code);
11455 gcc_assert (IS_EXPR_CODE_CLASS (kind)
11456 && TREE_CODE_LENGTH (code) == 3);
11458 /* Strip any conversions that don't change the mode. This is safe
11459 for every expression, except for a comparison expression because
11460 its signedness is derived from its operands. So, in the latter
11461 case, only strip conversions that don't change the signedness.
11463 Note that this is done as an internal manipulation within the
11464 constant folder, in order to find the simplest representation of
11465 the arguments so that their form can be studied. In any cases,
11466 the appropriate type conversions should be put back in the tree
11467 that will get out of the constant folder. */
11482 case COMPONENT_REF:
11483 if (TREE_CODE (arg0) == CONSTRUCTOR
11484 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
11486 unsigned HOST_WIDE_INT idx;
11488 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg0), idx, field, value)
11495 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
11496 so all simple results must be passed through pedantic_non_lvalue. */
11497 if (TREE_CODE (arg0) == INTEGER_CST)
11499 tree unused_op = integer_zerop (arg0) ? op1 : op2;
11500 tem = integer_zerop (arg0) ? op2 : op1;
11501 /* Only optimize constant conditions when the selected branch
11502 has the same type as the COND_EXPR. This avoids optimizing
11503 away "c ? x : throw", where the throw has a void type.
11504 Avoid throwing away that operand which contains label. */
11505 if ((!TREE_SIDE_EFFECTS (unused_op)
11506 || !contains_label_p (unused_op))
11507 && (! VOID_TYPE_P (TREE_TYPE (tem))
11508 || VOID_TYPE_P (type)))
11509 return pedantic_non_lvalue (tem);
11512 if (operand_equal_p (arg1, op2, 0))
11513 return pedantic_omit_one_operand (type, arg1, arg0);
11515 /* If we have A op B ? A : C, we may be able to convert this to a
11516 simpler expression, depending on the operation and the values
11517 of B and C. Signed zeros prevent all of these transformations,
11518 for reasons given above each one.
11520 Also try swapping the arguments and inverting the conditional. */
11521 if (COMPARISON_CLASS_P (arg0)
11522 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
11523 arg1, TREE_OPERAND (arg0, 1))
11524 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
11526 tem = fold_cond_expr_with_comparison (type, arg0, op1, op2);
11531 if (COMPARISON_CLASS_P (arg0)
11532 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
11534 TREE_OPERAND (arg0, 1))
11535 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op2))))
11537 tem = fold_truth_not_expr (arg0);
11538 if (tem && COMPARISON_CLASS_P (tem))
11540 tem = fold_cond_expr_with_comparison (type, tem, op2, op1);
11546 /* If the second operand is simpler than the third, swap them
11547 since that produces better jump optimization results. */
11548 if (truth_value_p (TREE_CODE (arg0))
11549 && tree_swap_operands_p (op1, op2, false))
11551 /* See if this can be inverted. If it can't, possibly because
11552 it was a floating-point inequality comparison, don't do
11554 tem = fold_truth_not_expr (arg0);
11556 return fold_build3 (code, type, tem, op2, op1);
11559 /* Convert A ? 1 : 0 to simply A. */
11560 if (integer_onep (op1)
11561 && integer_zerop (op2)
11562 /* If we try to convert OP0 to our type, the
11563 call to fold will try to move the conversion inside
11564 a COND, which will recurse. In that case, the COND_EXPR
11565 is probably the best choice, so leave it alone. */
11566 && type == TREE_TYPE (arg0))
11567 return pedantic_non_lvalue (arg0);
11569 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
11570 over COND_EXPR in cases such as floating point comparisons. */
11571 if (integer_zerop (op1)
11572 && integer_onep (op2)
11573 && truth_value_p (TREE_CODE (arg0)))
11574 return pedantic_non_lvalue (fold_convert (type,
11575 invert_truthvalue (arg0)));
11577 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
11578 if (TREE_CODE (arg0) == LT_EXPR
11579 && integer_zerop (TREE_OPERAND (arg0, 1))
11580 && integer_zerop (op2)
11581 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
11583 /* sign_bit_p only checks ARG1 bits within A's precision.
11584 If <sign bit of A> has wider type than A, bits outside
11585 of A's precision in <sign bit of A> need to be checked.
11586 If they are all 0, this optimization needs to be done
11587 in unsigned A's type, if they are all 1 in signed A's type,
11588 otherwise this can't be done. */
11589 if (TYPE_PRECISION (TREE_TYPE (tem))
11590 < TYPE_PRECISION (TREE_TYPE (arg1))
11591 && TYPE_PRECISION (TREE_TYPE (tem))
11592 < TYPE_PRECISION (type))
11594 unsigned HOST_WIDE_INT mask_lo;
11595 HOST_WIDE_INT mask_hi;
11596 int inner_width, outer_width;
11599 inner_width = TYPE_PRECISION (TREE_TYPE (tem));
11600 outer_width = TYPE_PRECISION (TREE_TYPE (arg1));
11601 if (outer_width > TYPE_PRECISION (type))
11602 outer_width = TYPE_PRECISION (type);
11604 if (outer_width > HOST_BITS_PER_WIDE_INT)
11606 mask_hi = ((unsigned HOST_WIDE_INT) -1
11607 >> (2 * HOST_BITS_PER_WIDE_INT - outer_width));
11613 mask_lo = ((unsigned HOST_WIDE_INT) -1
11614 >> (HOST_BITS_PER_WIDE_INT - outer_width));
11616 if (inner_width > HOST_BITS_PER_WIDE_INT)
11618 mask_hi &= ~((unsigned HOST_WIDE_INT) -1
11619 >> (HOST_BITS_PER_WIDE_INT - inner_width));
11623 mask_lo &= ~((unsigned HOST_WIDE_INT) -1
11624 >> (HOST_BITS_PER_WIDE_INT - inner_width));
11626 if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == mask_hi
11627 && (TREE_INT_CST_LOW (arg1) & mask_lo) == mask_lo)
11629 tem_type = lang_hooks.types.signed_type (TREE_TYPE (tem));
11630 tem = fold_convert (tem_type, tem);
11632 else if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == 0
11633 && (TREE_INT_CST_LOW (arg1) & mask_lo) == 0)
11635 tem_type = lang_hooks.types.unsigned_type (TREE_TYPE (tem));
11636 tem = fold_convert (tem_type, tem);
11643 return fold_convert (type,
11644 fold_build2 (BIT_AND_EXPR,
11645 TREE_TYPE (tem), tem,
11646 fold_convert (TREE_TYPE (tem),
11650 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
11651 already handled above. */
11652 if (TREE_CODE (arg0) == BIT_AND_EXPR
11653 && integer_onep (TREE_OPERAND (arg0, 1))
11654 && integer_zerop (op2)
11655 && integer_pow2p (arg1))
11657 tree tem = TREE_OPERAND (arg0, 0);
11659 if (TREE_CODE (tem) == RSHIFT_EXPR
11660 && TREE_CODE (TREE_OPERAND (tem, 1)) == INTEGER_CST
11661 && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
11662 TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
11663 return fold_build2 (BIT_AND_EXPR, type,
11664 TREE_OPERAND (tem, 0), arg1);
11667 /* A & N ? N : 0 is simply A & N if N is a power of two. This
11668 is probably obsolete because the first operand should be a
11669 truth value (that's why we have the two cases above), but let's
11670 leave it in until we can confirm this for all front-ends. */
11671 if (integer_zerop (op2)
11672 && TREE_CODE (arg0) == NE_EXPR
11673 && integer_zerop (TREE_OPERAND (arg0, 1))
11674 && integer_pow2p (arg1)
11675 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
11676 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
11677 arg1, OEP_ONLY_CONST))
11678 return pedantic_non_lvalue (fold_convert (type,
11679 TREE_OPERAND (arg0, 0)));
11681 /* Convert A ? B : 0 into A && B if A and B are truth values. */
11682 if (integer_zerop (op2)
11683 && truth_value_p (TREE_CODE (arg0))
11684 && truth_value_p (TREE_CODE (arg1)))
11685 return fold_build2 (TRUTH_ANDIF_EXPR, type,
11686 fold_convert (type, arg0),
11689 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
11690 if (integer_onep (op2)
11691 && truth_value_p (TREE_CODE (arg0))
11692 && truth_value_p (TREE_CODE (arg1)))
11694 /* Only perform transformation if ARG0 is easily inverted. */
11695 tem = fold_truth_not_expr (arg0);
11697 return fold_build2 (TRUTH_ORIF_EXPR, type,
11698 fold_convert (type, tem),
11702 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
11703 if (integer_zerop (arg1)
11704 && truth_value_p (TREE_CODE (arg0))
11705 && truth_value_p (TREE_CODE (op2)))
11707 /* Only perform transformation if ARG0 is easily inverted. */
11708 tem = fold_truth_not_expr (arg0);
11710 return fold_build2 (TRUTH_ANDIF_EXPR, type,
11711 fold_convert (type, tem),
11715 /* Convert A ? 1 : B into A || B if A and B are truth values. */
11716 if (integer_onep (arg1)
11717 && truth_value_p (TREE_CODE (arg0))
11718 && truth_value_p (TREE_CODE (op2)))
11719 return fold_build2 (TRUTH_ORIF_EXPR, type,
11720 fold_convert (type, arg0),
11726 /* Check for a built-in function. */
11727 if (TREE_CODE (op0) == ADDR_EXPR
11728 && TREE_CODE (TREE_OPERAND (op0, 0)) == FUNCTION_DECL
11729 && DECL_BUILT_IN (TREE_OPERAND (op0, 0)))
11730 return fold_builtin (TREE_OPERAND (op0, 0), op1, false);
11733 case BIT_FIELD_REF:
11734 if (TREE_CODE (arg0) == VECTOR_CST
11735 && type == TREE_TYPE (TREE_TYPE (arg0))
11736 && host_integerp (arg1, 1)
11737 && host_integerp (op2, 1))
11739 unsigned HOST_WIDE_INT width = tree_low_cst (arg1, 1);
11740 unsigned HOST_WIDE_INT idx = tree_low_cst (op2, 1);
11743 && simple_cst_equal (arg1, TYPE_SIZE (type)) == 1
11744 && (idx % width) == 0
11745 && (idx = idx / width)
11746 < TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0)))
11748 tree elements = TREE_VECTOR_CST_ELTS (arg0);
11749 while (idx-- > 0 && elements)
11750 elements = TREE_CHAIN (elements);
11752 return TREE_VALUE (elements);
11754 return fold_convert (type, integer_zero_node);
11761 } /* switch (code) */
11764 /* Perform constant folding and related simplification of EXPR.
11765 The related simplifications include x*1 => x, x*0 => 0, etc.,
11766 and application of the associative law.
11767 NOP_EXPR conversions may be removed freely (as long as we
11768 are careful not to change the type of the overall expression).
11769 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
11770 but we can constant-fold them if they have constant operands. */
11772 #ifdef ENABLE_FOLD_CHECKING
11773 # define fold(x) fold_1 (x)
11774 static tree fold_1 (tree);
11780 const tree t = expr;
11781 enum tree_code code = TREE_CODE (t);
11782 enum tree_code_class kind = TREE_CODE_CLASS (code);
11785 /* Return right away if a constant. */
11786 if (kind == tcc_constant)
11789 if (IS_EXPR_CODE_CLASS (kind))
11791 tree type = TREE_TYPE (t);
11792 tree op0, op1, op2;
11794 switch (TREE_CODE_LENGTH (code))
11797 op0 = TREE_OPERAND (t, 0);
11798 tem = fold_unary (code, type, op0);
11799 return tem ? tem : expr;
11801 op0 = TREE_OPERAND (t, 0);
11802 op1 = TREE_OPERAND (t, 1);
11803 tem = fold_binary (code, type, op0, op1);
11804 return tem ? tem : expr;
11806 op0 = TREE_OPERAND (t, 0);
11807 op1 = TREE_OPERAND (t, 1);
11808 op2 = TREE_OPERAND (t, 2);
11809 tem = fold_ternary (code, type, op0, op1, op2);
11810 return tem ? tem : expr;
11819 return fold (DECL_INITIAL (t));
11823 } /* switch (code) */
11826 #ifdef ENABLE_FOLD_CHECKING
11829 static void fold_checksum_tree (tree, struct md5_ctx *, htab_t);
11830 static void fold_check_failed (tree, tree);
11831 void print_fold_checksum (tree);
11833 /* When --enable-checking=fold, compute a digest of expr before
11834 and after actual fold call to see if fold did not accidentally
11835 change original expr. */
11841 struct md5_ctx ctx;
11842 unsigned char checksum_before[16], checksum_after[16];
11845 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
11846 md5_init_ctx (&ctx);
11847 fold_checksum_tree (expr, &ctx, ht);
11848 md5_finish_ctx (&ctx, checksum_before);
11851 ret = fold_1 (expr);
11853 md5_init_ctx (&ctx);
11854 fold_checksum_tree (expr, &ctx, ht);
11855 md5_finish_ctx (&ctx, checksum_after);
11858 if (memcmp (checksum_before, checksum_after, 16))
11859 fold_check_failed (expr, ret);
11865 print_fold_checksum (tree expr)
11867 struct md5_ctx ctx;
11868 unsigned char checksum[16], cnt;
11871 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
11872 md5_init_ctx (&ctx);
11873 fold_checksum_tree (expr, &ctx, ht);
11874 md5_finish_ctx (&ctx, checksum);
11876 for (cnt = 0; cnt < 16; ++cnt)
11877 fprintf (stderr, "%02x", checksum[cnt]);
11878 putc ('\n', stderr);
11882 fold_check_failed (tree expr ATTRIBUTE_UNUSED, tree ret ATTRIBUTE_UNUSED)
11884 internal_error ("fold check: original tree changed by fold");
11888 fold_checksum_tree (tree expr, struct md5_ctx *ctx, htab_t ht)
11891 enum tree_code code;
11892 struct tree_function_decl buf;
11897 gcc_assert ((sizeof (struct tree_exp) + 5 * sizeof (tree)
11898 <= sizeof (struct tree_function_decl))
11899 && sizeof (struct tree_type) <= sizeof (struct tree_function_decl));
11902 slot = htab_find_slot (ht, expr, INSERT);
11906 code = TREE_CODE (expr);
11907 if (TREE_CODE_CLASS (code) == tcc_declaration
11908 && DECL_ASSEMBLER_NAME_SET_P (expr))
11910 /* Allow DECL_ASSEMBLER_NAME to be modified. */
11911 memcpy ((char *) &buf, expr, tree_size (expr));
11912 expr = (tree) &buf;
11913 SET_DECL_ASSEMBLER_NAME (expr, NULL);
11915 else if (TREE_CODE_CLASS (code) == tcc_type
11916 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)
11917 || TYPE_CACHED_VALUES_P (expr)
11918 || TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr)))
11920 /* Allow these fields to be modified. */
11921 memcpy ((char *) &buf, expr, tree_size (expr));
11922 expr = (tree) &buf;
11923 TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr) = 0;
11924 TYPE_POINTER_TO (expr) = NULL;
11925 TYPE_REFERENCE_TO (expr) = NULL;
11926 if (TYPE_CACHED_VALUES_P (expr))
11928 TYPE_CACHED_VALUES_P (expr) = 0;
11929 TYPE_CACHED_VALUES (expr) = NULL;
11932 md5_process_bytes (expr, tree_size (expr), ctx);
11933 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
11934 if (TREE_CODE_CLASS (code) != tcc_type
11935 && TREE_CODE_CLASS (code) != tcc_declaration
11936 && code != TREE_LIST)
11937 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
11938 switch (TREE_CODE_CLASS (code))
11944 md5_process_bytes (TREE_STRING_POINTER (expr),
11945 TREE_STRING_LENGTH (expr), ctx);
11948 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
11949 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
11952 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
11958 case tcc_exceptional:
11962 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
11963 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
11964 expr = TREE_CHAIN (expr);
11965 goto recursive_label;
11968 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
11969 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
11975 case tcc_expression:
11976 case tcc_reference:
11977 case tcc_comparison:
11980 case tcc_statement:
11981 len = TREE_CODE_LENGTH (code);
11982 for (i = 0; i < len; ++i)
11983 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
11985 case tcc_declaration:
11986 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
11987 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
11988 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_COMMON))
11990 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
11991 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
11992 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
11993 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
11994 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
11996 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_WITH_VIS))
11997 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
11999 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_NON_COMMON))
12001 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
12002 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
12003 fold_checksum_tree (DECL_ARGUMENT_FLD (expr), ctx, ht);
12007 if (TREE_CODE (expr) == ENUMERAL_TYPE)
12008 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
12009 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
12010 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
12011 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
12012 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
12013 if (INTEGRAL_TYPE_P (expr)
12014 || SCALAR_FLOAT_TYPE_P (expr))
12016 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
12017 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
12019 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
12020 if (TREE_CODE (expr) == RECORD_TYPE
12021 || TREE_CODE (expr) == UNION_TYPE
12022 || TREE_CODE (expr) == QUAL_UNION_TYPE)
12023 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
12024 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
12033 /* Fold a unary tree expression with code CODE of type TYPE with an
12034 operand OP0. Return a folded expression if successful. Otherwise,
12035 return a tree expression with code CODE of type TYPE with an
12039 fold_build1_stat (enum tree_code code, tree type, tree op0 MEM_STAT_DECL)
12042 #ifdef ENABLE_FOLD_CHECKING
12043 unsigned char checksum_before[16], checksum_after[16];
12044 struct md5_ctx ctx;
12047 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
12048 md5_init_ctx (&ctx);
12049 fold_checksum_tree (op0, &ctx, ht);
12050 md5_finish_ctx (&ctx, checksum_before);
12054 tem = fold_unary (code, type, op0);
12056 tem = build1_stat (code, type, op0 PASS_MEM_STAT);
12058 #ifdef ENABLE_FOLD_CHECKING
12059 md5_init_ctx (&ctx);
12060 fold_checksum_tree (op0, &ctx, ht);
12061 md5_finish_ctx (&ctx, checksum_after);
12064 if (memcmp (checksum_before, checksum_after, 16))
12065 fold_check_failed (op0, tem);
12070 /* Fold a binary tree expression with code CODE of type TYPE with
12071 operands OP0 and OP1. Return a folded expression if successful.
12072 Otherwise, return a tree expression with code CODE of type TYPE
12073 with operands OP0 and OP1. */
12076 fold_build2_stat (enum tree_code code, tree type, tree op0, tree op1
12080 #ifdef ENABLE_FOLD_CHECKING
12081 unsigned char checksum_before_op0[16],
12082 checksum_before_op1[16],
12083 checksum_after_op0[16],
12084 checksum_after_op1[16];
12085 struct md5_ctx ctx;
12088 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
12089 md5_init_ctx (&ctx);
12090 fold_checksum_tree (op0, &ctx, ht);
12091 md5_finish_ctx (&ctx, checksum_before_op0);
12094 md5_init_ctx (&ctx);
12095 fold_checksum_tree (op1, &ctx, ht);
12096 md5_finish_ctx (&ctx, checksum_before_op1);
12100 tem = fold_binary (code, type, op0, op1);
12102 tem = build2_stat (code, type, op0, op1 PASS_MEM_STAT);
12104 #ifdef ENABLE_FOLD_CHECKING
12105 md5_init_ctx (&ctx);
12106 fold_checksum_tree (op0, &ctx, ht);
12107 md5_finish_ctx (&ctx, checksum_after_op0);
12110 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
12111 fold_check_failed (op0, tem);
12113 md5_init_ctx (&ctx);
12114 fold_checksum_tree (op1, &ctx, ht);
12115 md5_finish_ctx (&ctx, checksum_after_op1);
12118 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
12119 fold_check_failed (op1, tem);
12124 /* Fold a ternary tree expression with code CODE of type TYPE with
12125 operands OP0, OP1, and OP2. Return a folded expression if
12126 successful. Otherwise, return a tree expression with code CODE of
12127 type TYPE with operands OP0, OP1, and OP2. */
12130 fold_build3_stat (enum tree_code code, tree type, tree op0, tree op1, tree op2
12134 #ifdef ENABLE_FOLD_CHECKING
12135 unsigned char checksum_before_op0[16],
12136 checksum_before_op1[16],
12137 checksum_before_op2[16],
12138 checksum_after_op0[16],
12139 checksum_after_op1[16],
12140 checksum_after_op2[16];
12141 struct md5_ctx ctx;
12144 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
12145 md5_init_ctx (&ctx);
12146 fold_checksum_tree (op0, &ctx, ht);
12147 md5_finish_ctx (&ctx, checksum_before_op0);
12150 md5_init_ctx (&ctx);
12151 fold_checksum_tree (op1, &ctx, ht);
12152 md5_finish_ctx (&ctx, checksum_before_op1);
12155 md5_init_ctx (&ctx);
12156 fold_checksum_tree (op2, &ctx, ht);
12157 md5_finish_ctx (&ctx, checksum_before_op2);
12161 tem = fold_ternary (code, type, op0, op1, op2);
12163 tem = build3_stat (code, type, op0, op1, op2 PASS_MEM_STAT);
12165 #ifdef ENABLE_FOLD_CHECKING
12166 md5_init_ctx (&ctx);
12167 fold_checksum_tree (op0, &ctx, ht);
12168 md5_finish_ctx (&ctx, checksum_after_op0);
12171 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
12172 fold_check_failed (op0, tem);
12174 md5_init_ctx (&ctx);
12175 fold_checksum_tree (op1, &ctx, ht);
12176 md5_finish_ctx (&ctx, checksum_after_op1);
12179 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
12180 fold_check_failed (op1, tem);
12182 md5_init_ctx (&ctx);
12183 fold_checksum_tree (op2, &ctx, ht);
12184 md5_finish_ctx (&ctx, checksum_after_op2);
12187 if (memcmp (checksum_before_op2, checksum_after_op2, 16))
12188 fold_check_failed (op2, tem);
12193 /* Perform constant folding and related simplification of initializer
12194 expression EXPR. These behave identically to "fold_buildN" but ignore
12195 potential run-time traps and exceptions that fold must preserve. */
12197 #define START_FOLD_INIT \
12198 int saved_signaling_nans = flag_signaling_nans;\
12199 int saved_trapping_math = flag_trapping_math;\
12200 int saved_rounding_math = flag_rounding_math;\
12201 int saved_trapv = flag_trapv;\
12202 int saved_folding_initializer = folding_initializer;\
12203 flag_signaling_nans = 0;\
12204 flag_trapping_math = 0;\
12205 flag_rounding_math = 0;\
12207 folding_initializer = 1;
12209 #define END_FOLD_INIT \
12210 flag_signaling_nans = saved_signaling_nans;\
12211 flag_trapping_math = saved_trapping_math;\
12212 flag_rounding_math = saved_rounding_math;\
12213 flag_trapv = saved_trapv;\
12214 folding_initializer = saved_folding_initializer;
12217 fold_build1_initializer (enum tree_code code, tree type, tree op)
12222 result = fold_build1 (code, type, op);
12229 fold_build2_initializer (enum tree_code code, tree type, tree op0, tree op1)
12234 result = fold_build2 (code, type, op0, op1);
12241 fold_build3_initializer (enum tree_code code, tree type, tree op0, tree op1,
12247 result = fold_build3 (code, type, op0, op1, op2);
12253 #undef START_FOLD_INIT
12254 #undef END_FOLD_INIT
12256 /* Determine if first argument is a multiple of second argument. Return 0 if
12257 it is not, or we cannot easily determined it to be.
12259 An example of the sort of thing we care about (at this point; this routine
12260 could surely be made more general, and expanded to do what the *_DIV_EXPR's
12261 fold cases do now) is discovering that
12263 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
12269 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
12271 This code also handles discovering that
12273 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
12275 is a multiple of 8 so we don't have to worry about dealing with a
12276 possible remainder.
12278 Note that we *look* inside a SAVE_EXPR only to determine how it was
12279 calculated; it is not safe for fold to do much of anything else with the
12280 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
12281 at run time. For example, the latter example above *cannot* be implemented
12282 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
12283 evaluation time of the original SAVE_EXPR is not necessarily the same at
12284 the time the new expression is evaluated. The only optimization of this
12285 sort that would be valid is changing
12287 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
12291 SAVE_EXPR (I) * SAVE_EXPR (J)
12293 (where the same SAVE_EXPR (J) is used in the original and the
12294 transformed version). */
12297 multiple_of_p (tree type, tree top, tree bottom)
12299 if (operand_equal_p (top, bottom, 0))
12302 if (TREE_CODE (type) != INTEGER_TYPE)
12305 switch (TREE_CODE (top))
12308 /* Bitwise and provides a power of two multiple. If the mask is
12309 a multiple of BOTTOM then TOP is a multiple of BOTTOM. */
12310 if (!integer_pow2p (bottom))
12315 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
12316 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
12320 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
12321 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
12324 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
12328 op1 = TREE_OPERAND (top, 1);
12329 /* const_binop may not detect overflow correctly,
12330 so check for it explicitly here. */
12331 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
12332 > TREE_INT_CST_LOW (op1)
12333 && TREE_INT_CST_HIGH (op1) == 0
12334 && 0 != (t1 = fold_convert (type,
12335 const_binop (LSHIFT_EXPR,
12338 && ! TREE_OVERFLOW (t1))
12339 return multiple_of_p (type, t1, bottom);
12344 /* Can't handle conversions from non-integral or wider integral type. */
12345 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
12346 || (TYPE_PRECISION (type)
12347 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
12350 /* .. fall through ... */
12353 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
12356 if (TREE_CODE (bottom) != INTEGER_CST
12357 || (TYPE_UNSIGNED (type)
12358 && (tree_int_cst_sgn (top) < 0
12359 || tree_int_cst_sgn (bottom) < 0)))
12361 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
12369 /* Return true if `t' is known to be non-negative. If the return
12370 value is based on the assumption that signed overflow is undefined,
12371 set *STRICT_OVERFLOW_P to true; otherwise, don't change
12372 *STRICT_OVERFLOW_P. */
12375 tree_expr_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
12377 if (t == error_mark_node)
12380 if (TYPE_UNSIGNED (TREE_TYPE (t)))
12383 switch (TREE_CODE (t))
12386 /* Query VRP to see if it has recorded any information about
12387 the range of this object. */
12388 return ssa_name_nonnegative_p (t);
12391 /* We can't return 1 if flag_wrapv is set because
12392 ABS_EXPR<INT_MIN> = INT_MIN. */
12393 if (!INTEGRAL_TYPE_P (TREE_TYPE (t)))
12395 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t)))
12397 *strict_overflow_p = true;
12403 return tree_int_cst_sgn (t) >= 0;
12406 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
12409 if (FLOAT_TYPE_P (TREE_TYPE (t)))
12410 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
12412 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
12413 strict_overflow_p));
12415 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
12416 both unsigned and at least 2 bits shorter than the result. */
12417 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
12418 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
12419 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
12421 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
12422 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
12423 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
12424 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
12426 unsigned int prec = MAX (TYPE_PRECISION (inner1),
12427 TYPE_PRECISION (inner2)) + 1;
12428 return prec < TYPE_PRECISION (TREE_TYPE (t));
12434 if (FLOAT_TYPE_P (TREE_TYPE (t)))
12436 /* x * x for floating point x is always non-negative. */
12437 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
12439 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
12441 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
12442 strict_overflow_p));
12445 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
12446 both unsigned and their total bits is shorter than the result. */
12447 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
12448 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
12449 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
12451 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
12452 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
12453 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
12454 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
12455 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
12456 < TYPE_PRECISION (TREE_TYPE (t));
12462 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
12464 || tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
12465 strict_overflow_p));
12471 case TRUNC_DIV_EXPR:
12472 case CEIL_DIV_EXPR:
12473 case FLOOR_DIV_EXPR:
12474 case ROUND_DIV_EXPR:
12475 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
12477 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
12478 strict_overflow_p));
12480 case TRUNC_MOD_EXPR:
12481 case CEIL_MOD_EXPR:
12482 case FLOOR_MOD_EXPR:
12483 case ROUND_MOD_EXPR:
12485 case NON_LVALUE_EXPR:
12487 case FIX_TRUNC_EXPR:
12488 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
12489 strict_overflow_p);
12491 case COMPOUND_EXPR:
12493 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
12494 strict_overflow_p);
12497 return tree_expr_nonnegative_warnv_p (expr_last (TREE_OPERAND (t, 1)),
12498 strict_overflow_p);
12501 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
12503 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 2),
12504 strict_overflow_p));
12508 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
12509 tree outer_type = TREE_TYPE (t);
12511 if (TREE_CODE (outer_type) == REAL_TYPE)
12513 if (TREE_CODE (inner_type) == REAL_TYPE)
12514 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
12515 strict_overflow_p);
12516 if (TREE_CODE (inner_type) == INTEGER_TYPE)
12518 if (TYPE_UNSIGNED (inner_type))
12520 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
12521 strict_overflow_p);
12524 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
12526 if (TREE_CODE (inner_type) == REAL_TYPE)
12527 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t,0),
12528 strict_overflow_p);
12529 if (TREE_CODE (inner_type) == INTEGER_TYPE)
12530 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
12531 && TYPE_UNSIGNED (inner_type);
12538 tree temp = TARGET_EXPR_SLOT (t);
12539 t = TARGET_EXPR_INITIAL (t);
12541 /* If the initializer is non-void, then it's a normal expression
12542 that will be assigned to the slot. */
12543 if (!VOID_TYPE_P (t))
12544 return tree_expr_nonnegative_warnv_p (t, strict_overflow_p);
12546 /* Otherwise, the initializer sets the slot in some way. One common
12547 way is an assignment statement at the end of the initializer. */
12550 if (TREE_CODE (t) == BIND_EXPR)
12551 t = expr_last (BIND_EXPR_BODY (t));
12552 else if (TREE_CODE (t) == TRY_FINALLY_EXPR
12553 || TREE_CODE (t) == TRY_CATCH_EXPR)
12554 t = expr_last (TREE_OPERAND (t, 0));
12555 else if (TREE_CODE (t) == STATEMENT_LIST)
12560 if (TREE_CODE (t) == MODIFY_EXPR
12561 && TREE_OPERAND (t, 0) == temp)
12562 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
12563 strict_overflow_p);
12570 tree fndecl = get_callee_fndecl (t);
12571 tree arglist = TREE_OPERAND (t, 1);
12572 if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
12573 switch (DECL_FUNCTION_CODE (fndecl))
12575 CASE_FLT_FN (BUILT_IN_ACOS):
12576 CASE_FLT_FN (BUILT_IN_ACOSH):
12577 CASE_FLT_FN (BUILT_IN_CABS):
12578 CASE_FLT_FN (BUILT_IN_COSH):
12579 CASE_FLT_FN (BUILT_IN_ERFC):
12580 CASE_FLT_FN (BUILT_IN_EXP):
12581 CASE_FLT_FN (BUILT_IN_EXP10):
12582 CASE_FLT_FN (BUILT_IN_EXP2):
12583 CASE_FLT_FN (BUILT_IN_FABS):
12584 CASE_FLT_FN (BUILT_IN_FDIM):
12585 CASE_FLT_FN (BUILT_IN_HYPOT):
12586 CASE_FLT_FN (BUILT_IN_POW10):
12587 CASE_INT_FN (BUILT_IN_FFS):
12588 CASE_INT_FN (BUILT_IN_PARITY):
12589 CASE_INT_FN (BUILT_IN_POPCOUNT):
12593 CASE_FLT_FN (BUILT_IN_SQRT):
12594 /* sqrt(-0.0) is -0.0. */
12595 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (t))))
12597 return tree_expr_nonnegative_warnv_p (TREE_VALUE (arglist),
12598 strict_overflow_p);
12600 CASE_FLT_FN (BUILT_IN_ASINH):
12601 CASE_FLT_FN (BUILT_IN_ATAN):
12602 CASE_FLT_FN (BUILT_IN_ATANH):
12603 CASE_FLT_FN (BUILT_IN_CBRT):
12604 CASE_FLT_FN (BUILT_IN_CEIL):
12605 CASE_FLT_FN (BUILT_IN_ERF):
12606 CASE_FLT_FN (BUILT_IN_EXPM1):
12607 CASE_FLT_FN (BUILT_IN_FLOOR):
12608 CASE_FLT_FN (BUILT_IN_FMOD):
12609 CASE_FLT_FN (BUILT_IN_FREXP):
12610 CASE_FLT_FN (BUILT_IN_LCEIL):
12611 CASE_FLT_FN (BUILT_IN_LDEXP):
12612 CASE_FLT_FN (BUILT_IN_LFLOOR):
12613 CASE_FLT_FN (BUILT_IN_LLCEIL):
12614 CASE_FLT_FN (BUILT_IN_LLFLOOR):
12615 CASE_FLT_FN (BUILT_IN_LLRINT):
12616 CASE_FLT_FN (BUILT_IN_LLROUND):
12617 CASE_FLT_FN (BUILT_IN_LRINT):
12618 CASE_FLT_FN (BUILT_IN_LROUND):
12619 CASE_FLT_FN (BUILT_IN_MODF):
12620 CASE_FLT_FN (BUILT_IN_NEARBYINT):
12621 CASE_FLT_FN (BUILT_IN_POW):
12622 CASE_FLT_FN (BUILT_IN_RINT):
12623 CASE_FLT_FN (BUILT_IN_ROUND):
12624 CASE_FLT_FN (BUILT_IN_SIGNBIT):
12625 CASE_FLT_FN (BUILT_IN_SINH):
12626 CASE_FLT_FN (BUILT_IN_TANH):
12627 CASE_FLT_FN (BUILT_IN_TRUNC):
12628 /* True if the 1st argument is nonnegative. */
12629 return tree_expr_nonnegative_warnv_p (TREE_VALUE (arglist),
12630 strict_overflow_p);
12632 CASE_FLT_FN (BUILT_IN_FMAX):
12633 /* True if the 1st OR 2nd arguments are nonnegative. */
12634 return (tree_expr_nonnegative_warnv_p (TREE_VALUE (arglist),
12636 || (tree_expr_nonnegative_warnv_p
12637 (TREE_VALUE (TREE_CHAIN (arglist)),
12638 strict_overflow_p)));
12640 CASE_FLT_FN (BUILT_IN_FMIN):
12641 /* True if the 1st AND 2nd arguments are nonnegative. */
12642 return (tree_expr_nonnegative_warnv_p (TREE_VALUE (arglist),
12644 && (tree_expr_nonnegative_warnv_p
12645 (TREE_VALUE (TREE_CHAIN (arglist)),
12646 strict_overflow_p)));
12648 CASE_FLT_FN (BUILT_IN_COPYSIGN):
12649 /* True if the 2nd argument is nonnegative. */
12650 return (tree_expr_nonnegative_warnv_p
12651 (TREE_VALUE (TREE_CHAIN (arglist)),
12652 strict_overflow_p));
12659 /* ... fall through ... */
12663 tree type = TREE_TYPE (t);
12664 if ((TYPE_PRECISION (type) != 1 || TYPE_UNSIGNED (type))
12665 && truth_value_p (TREE_CODE (t)))
12666 /* Truth values evaluate to 0 or 1, which is nonnegative unless we
12667 have a signed:1 type (where the value is -1 and 0). */
12672 /* We don't know sign of `t', so be conservative and return false. */
12676 /* Return true if `t' is known to be non-negative. Handle warnings
12677 about undefined signed overflow. */
12680 tree_expr_nonnegative_p (tree t)
12683 bool strict_overflow_p;
12685 strict_overflow_p = false;
12686 ret = tree_expr_nonnegative_warnv_p (t, &strict_overflow_p);
12687 if (strict_overflow_p)
12688 fold_overflow_warning (("assuming signed overflow does not occur when "
12689 "determining that expression is always "
12691 WARN_STRICT_OVERFLOW_MISC);
12695 /* Return true when T is an address and is known to be nonzero.
12696 For floating point we further ensure that T is not denormal.
12697 Similar logic is present in nonzero_address in rtlanal.h.
12699 If the return value is based on the assumption that signed overflow
12700 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
12701 change *STRICT_OVERFLOW_P. */
12704 tree_expr_nonzero_warnv_p (tree t, bool *strict_overflow_p)
12706 tree type = TREE_TYPE (t);
12707 bool sub_strict_overflow_p;
12709 /* Doing something useful for floating point would need more work. */
12710 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
12713 switch (TREE_CODE (t))
12716 /* Query VRP to see if it has recorded any information about
12717 the range of this object. */
12718 return ssa_name_nonzero_p (t);
12721 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
12722 strict_overflow_p);
12725 /* We used to test for !integer_zerop here. This does not work correctly
12726 if TREE_CONSTANT_OVERFLOW (t). */
12727 return (TREE_INT_CST_LOW (t) != 0
12728 || TREE_INT_CST_HIGH (t) != 0);
12731 if (TYPE_OVERFLOW_UNDEFINED (type))
12733 /* With the presence of negative values it is hard
12734 to say something. */
12735 sub_strict_overflow_p = false;
12736 if (!tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
12737 &sub_strict_overflow_p)
12738 || !tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
12739 &sub_strict_overflow_p))
12741 /* One of operands must be positive and the other non-negative. */
12742 /* We don't set *STRICT_OVERFLOW_P here: even if this value
12743 overflows, on a twos-complement machine the sum of two
12744 nonnegative numbers can never be zero. */
12745 return (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
12747 || tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
12748 strict_overflow_p));
12753 if (TYPE_OVERFLOW_UNDEFINED (type))
12755 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
12757 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
12758 strict_overflow_p))
12760 *strict_overflow_p = true;
12768 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
12769 tree outer_type = TREE_TYPE (t);
12771 return (TYPE_PRECISION (outer_type) >= TYPE_PRECISION (inner_type)
12772 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
12773 strict_overflow_p));
12779 tree base = get_base_address (TREE_OPERAND (t, 0));
12784 /* Weak declarations may link to NULL. */
12785 if (VAR_OR_FUNCTION_DECL_P (base))
12786 return !DECL_WEAK (base);
12788 /* Constants are never weak. */
12789 if (CONSTANT_CLASS_P (base))
12796 sub_strict_overflow_p = false;
12797 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
12798 &sub_strict_overflow_p)
12799 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 2),
12800 &sub_strict_overflow_p))
12802 if (sub_strict_overflow_p)
12803 *strict_overflow_p = true;
12809 sub_strict_overflow_p = false;
12810 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
12811 &sub_strict_overflow_p)
12812 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
12813 &sub_strict_overflow_p))
12815 if (sub_strict_overflow_p)
12816 *strict_overflow_p = true;
12821 sub_strict_overflow_p = false;
12822 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
12823 &sub_strict_overflow_p))
12825 if (sub_strict_overflow_p)
12826 *strict_overflow_p = true;
12828 /* When both operands are nonzero, then MAX must be too. */
12829 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
12830 strict_overflow_p))
12833 /* MAX where operand 0 is positive is positive. */
12834 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
12835 strict_overflow_p);
12837 /* MAX where operand 1 is positive is positive. */
12838 else if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
12839 &sub_strict_overflow_p)
12840 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
12841 &sub_strict_overflow_p))
12843 if (sub_strict_overflow_p)
12844 *strict_overflow_p = true;
12849 case COMPOUND_EXPR:
12852 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
12853 strict_overflow_p);
12856 case NON_LVALUE_EXPR:
12857 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
12858 strict_overflow_p);
12861 return (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
12863 || tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
12864 strict_overflow_p));
12867 return alloca_call_p (t);
12875 /* Return true when T is an address and is known to be nonzero.
12876 Handle warnings about undefined signed overflow. */
12879 tree_expr_nonzero_p (tree t)
12881 bool ret, strict_overflow_p;
12883 strict_overflow_p = false;
12884 ret = tree_expr_nonzero_warnv_p (t, &strict_overflow_p);
12885 if (strict_overflow_p)
12886 fold_overflow_warning (("assuming signed overflow does not occur when "
12887 "determining that expression is always "
12889 WARN_STRICT_OVERFLOW_MISC);
12893 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
12894 attempt to fold the expression to a constant without modifying TYPE,
12897 If the expression could be simplified to a constant, then return
12898 the constant. If the expression would not be simplified to a
12899 constant, then return NULL_TREE. */
12902 fold_binary_to_constant (enum tree_code code, tree type, tree op0, tree op1)
12904 tree tem = fold_binary (code, type, op0, op1);
12905 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
12908 /* Given the components of a unary expression CODE, TYPE and OP0,
12909 attempt to fold the expression to a constant without modifying
12912 If the expression could be simplified to a constant, then return
12913 the constant. If the expression would not be simplified to a
12914 constant, then return NULL_TREE. */
12917 fold_unary_to_constant (enum tree_code code, tree type, tree op0)
12919 tree tem = fold_unary (code, type, op0);
12920 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
12923 /* If EXP represents referencing an element in a constant string
12924 (either via pointer arithmetic or array indexing), return the
12925 tree representing the value accessed, otherwise return NULL. */
12928 fold_read_from_constant_string (tree exp)
12930 if ((TREE_CODE (exp) == INDIRECT_REF
12931 || TREE_CODE (exp) == ARRAY_REF)
12932 && TREE_CODE (TREE_TYPE (exp)) == INTEGER_TYPE)
12934 tree exp1 = TREE_OPERAND (exp, 0);
12938 if (TREE_CODE (exp) == INDIRECT_REF)
12939 string = string_constant (exp1, &index);
12942 tree low_bound = array_ref_low_bound (exp);
12943 index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
12945 /* Optimize the special-case of a zero lower bound.
12947 We convert the low_bound to sizetype to avoid some problems
12948 with constant folding. (E.g. suppose the lower bound is 1,
12949 and its mode is QI. Without the conversion,l (ARRAY
12950 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
12951 +INDEX), which becomes (ARRAY+255+INDEX). Opps!) */
12952 if (! integer_zerop (low_bound))
12953 index = size_diffop (index, fold_convert (sizetype, low_bound));
12959 && TYPE_MODE (TREE_TYPE (exp)) == TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))
12960 && TREE_CODE (string) == STRING_CST
12961 && TREE_CODE (index) == INTEGER_CST
12962 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
12963 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
12965 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
12966 return fold_convert (TREE_TYPE (exp),
12967 build_int_cst (NULL_TREE,
12968 (TREE_STRING_POINTER (string)
12969 [TREE_INT_CST_LOW (index)])));
12974 /* Return the tree for neg (ARG0) when ARG0 is known to be either
12975 an integer constant or real constant.
12977 TYPE is the type of the result. */
12980 fold_negate_const (tree arg0, tree type)
12982 tree t = NULL_TREE;
12984 switch (TREE_CODE (arg0))
12988 unsigned HOST_WIDE_INT low;
12989 HOST_WIDE_INT high;
12990 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
12991 TREE_INT_CST_HIGH (arg0),
12993 t = build_int_cst_wide (type, low, high);
12994 t = force_fit_type (t, 1,
12995 (overflow | TREE_OVERFLOW (arg0))
12996 && !TYPE_UNSIGNED (type),
12997 TREE_CONSTANT_OVERFLOW (arg0));
13002 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
13006 gcc_unreachable ();
13012 /* Return the tree for abs (ARG0) when ARG0 is known to be either
13013 an integer constant or real constant.
13015 TYPE is the type of the result. */
13018 fold_abs_const (tree arg0, tree type)
13020 tree t = NULL_TREE;
13022 switch (TREE_CODE (arg0))
13025 /* If the value is unsigned, then the absolute value is
13026 the same as the ordinary value. */
13027 if (TYPE_UNSIGNED (type))
13029 /* Similarly, if the value is non-negative. */
13030 else if (INT_CST_LT (integer_minus_one_node, arg0))
13032 /* If the value is negative, then the absolute value is
13036 unsigned HOST_WIDE_INT low;
13037 HOST_WIDE_INT high;
13038 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
13039 TREE_INT_CST_HIGH (arg0),
13041 t = build_int_cst_wide (type, low, high);
13042 t = force_fit_type (t, -1, overflow | TREE_OVERFLOW (arg0),
13043 TREE_CONSTANT_OVERFLOW (arg0));
13048 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
13049 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
13055 gcc_unreachable ();
13061 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
13062 constant. TYPE is the type of the result. */
13065 fold_not_const (tree arg0, tree type)
13067 tree t = NULL_TREE;
13069 gcc_assert (TREE_CODE (arg0) == INTEGER_CST);
13071 t = build_int_cst_wide (type,
13072 ~ TREE_INT_CST_LOW (arg0),
13073 ~ TREE_INT_CST_HIGH (arg0));
13074 t = force_fit_type (t, 0, TREE_OVERFLOW (arg0),
13075 TREE_CONSTANT_OVERFLOW (arg0));
13080 /* Given CODE, a relational operator, the target type, TYPE and two
13081 constant operands OP0 and OP1, return the result of the
13082 relational operation. If the result is not a compile time
13083 constant, then return NULL_TREE. */
13086 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
13088 int result, invert;
13090 /* From here on, the only cases we handle are when the result is
13091 known to be a constant. */
13093 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
13095 const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
13096 const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);
13098 /* Handle the cases where either operand is a NaN. */
13099 if (real_isnan (c0) || real_isnan (c1))
13109 case UNORDERED_EXPR:
13123 if (flag_trapping_math)
13129 gcc_unreachable ();
13132 return constant_boolean_node (result, type);
13135 return constant_boolean_node (real_compare (code, c0, c1), type);
13138 /* Handle equality/inequality of complex constants. */
13139 if (TREE_CODE (op0) == COMPLEX_CST && TREE_CODE (op1) == COMPLEX_CST)
13141 tree rcond = fold_relational_const (code, type,
13142 TREE_REALPART (op0),
13143 TREE_REALPART (op1));
13144 tree icond = fold_relational_const (code, type,
13145 TREE_IMAGPART (op0),
13146 TREE_IMAGPART (op1));
13147 if (code == EQ_EXPR)
13148 return fold_build2 (TRUTH_ANDIF_EXPR, type, rcond, icond);
13149 else if (code == NE_EXPR)
13150 return fold_build2 (TRUTH_ORIF_EXPR, type, rcond, icond);
13155 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
13157 To compute GT, swap the arguments and do LT.
13158 To compute GE, do LT and invert the result.
13159 To compute LE, swap the arguments, do LT and invert the result.
13160 To compute NE, do EQ and invert the result.
13162 Therefore, the code below must handle only EQ and LT. */
13164 if (code == LE_EXPR || code == GT_EXPR)
13169 code = swap_tree_comparison (code);
13172 /* Note that it is safe to invert for real values here because we
13173 have already handled the one case that it matters. */
13176 if (code == NE_EXPR || code == GE_EXPR)
13179 code = invert_tree_comparison (code, false);
13182 /* Compute a result for LT or EQ if args permit;
13183 Otherwise return T. */
13184 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
13186 if (code == EQ_EXPR)
13187 result = tree_int_cst_equal (op0, op1);
13188 else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
13189 result = INT_CST_LT_UNSIGNED (op0, op1);
13191 result = INT_CST_LT (op0, op1);
13198 return constant_boolean_node (result, type);
13201 /* Build an expression for the a clean point containing EXPR with type TYPE.
13202 Don't build a cleanup point expression for EXPR which don't have side
13206 fold_build_cleanup_point_expr (tree type, tree expr)
13208 /* If the expression does not have side effects then we don't have to wrap
13209 it with a cleanup point expression. */
13210 if (!TREE_SIDE_EFFECTS (expr))
13213 /* If the expression is a return, check to see if the expression inside the
13214 return has no side effects or the right hand side of the modify expression
13215 inside the return. If either don't have side effects set we don't need to
13216 wrap the expression in a cleanup point expression. Note we don't check the
13217 left hand side of the modify because it should always be a return decl. */
13218 if (TREE_CODE (expr) == RETURN_EXPR)
13220 tree op = TREE_OPERAND (expr, 0);
13221 if (!op || !TREE_SIDE_EFFECTS (op))
13223 op = TREE_OPERAND (op, 1);
13224 if (!TREE_SIDE_EFFECTS (op))
13228 return build1 (CLEANUP_POINT_EXPR, type, expr);
13231 /* Build an expression for the address of T. Folds away INDIRECT_REF to
13232 avoid confusing the gimplify process. */
13235 build_fold_addr_expr_with_type (tree t, tree ptrtype)
13237 /* The size of the object is not relevant when talking about its address. */
13238 if (TREE_CODE (t) == WITH_SIZE_EXPR)
13239 t = TREE_OPERAND (t, 0);
13241 /* Note: doesn't apply to ALIGN_INDIRECT_REF */
13242 if (TREE_CODE (t) == INDIRECT_REF
13243 || TREE_CODE (t) == MISALIGNED_INDIRECT_REF)
13245 t = TREE_OPERAND (t, 0);
13246 if (TREE_TYPE (t) != ptrtype)
13247 t = build1 (NOP_EXPR, ptrtype, t);
13253 while (handled_component_p (base))
13254 base = TREE_OPERAND (base, 0);
13256 TREE_ADDRESSABLE (base) = 1;
13258 t = build1 (ADDR_EXPR, ptrtype, t);
13265 build_fold_addr_expr (tree t)
13267 return build_fold_addr_expr_with_type (t, build_pointer_type (TREE_TYPE (t)));
13270 /* Given a pointer value OP0 and a type TYPE, return a simplified version
13271 of an indirection through OP0, or NULL_TREE if no simplification is
13275 fold_indirect_ref_1 (tree type, tree op0)
13281 subtype = TREE_TYPE (sub);
13282 if (!POINTER_TYPE_P (subtype))
13285 if (TREE_CODE (sub) == ADDR_EXPR)
13287 tree op = TREE_OPERAND (sub, 0);
13288 tree optype = TREE_TYPE (op);
13289 /* *&CONST_DECL -> to the value of the const decl. */
13290 if (TREE_CODE (op) == CONST_DECL)
13291 return DECL_INITIAL (op);
13292 /* *&p => p; make sure to handle *&"str"[cst] here. */
13293 if (type == optype)
13295 tree fop = fold_read_from_constant_string (op);
13301 /* *(foo *)&fooarray => fooarray[0] */
13302 else if (TREE_CODE (optype) == ARRAY_TYPE
13303 && type == TREE_TYPE (optype))
13305 tree type_domain = TYPE_DOMAIN (optype);
13306 tree min_val = size_zero_node;
13307 if (type_domain && TYPE_MIN_VALUE (type_domain))
13308 min_val = TYPE_MIN_VALUE (type_domain);
13309 return build4 (ARRAY_REF, type, op, min_val, NULL_TREE, NULL_TREE);
13311 /* *(foo *)&complexfoo => __real__ complexfoo */
13312 else if (TREE_CODE (optype) == COMPLEX_TYPE
13313 && type == TREE_TYPE (optype))
13314 return fold_build1 (REALPART_EXPR, type, op);
13317 /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */
13318 if (TREE_CODE (sub) == PLUS_EXPR
13319 && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
13321 tree op00 = TREE_OPERAND (sub, 0);
13322 tree op01 = TREE_OPERAND (sub, 1);
13326 op00type = TREE_TYPE (op00);
13327 if (TREE_CODE (op00) == ADDR_EXPR
13328 && TREE_CODE (TREE_TYPE (op00type)) == COMPLEX_TYPE
13329 && type == TREE_TYPE (TREE_TYPE (op00type)))
13331 tree size = TYPE_SIZE_UNIT (type);
13332 if (tree_int_cst_equal (size, op01))
13333 return fold_build1 (IMAGPART_EXPR, type, TREE_OPERAND (op00, 0));
13337 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
13338 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
13339 && type == TREE_TYPE (TREE_TYPE (subtype)))
13342 tree min_val = size_zero_node;
13343 sub = build_fold_indirect_ref (sub);
13344 type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
13345 if (type_domain && TYPE_MIN_VALUE (type_domain))
13346 min_val = TYPE_MIN_VALUE (type_domain);
13347 return build4 (ARRAY_REF, type, sub, min_val, NULL_TREE, NULL_TREE);
13353 /* Builds an expression for an indirection through T, simplifying some
13357 build_fold_indirect_ref (tree t)
13359 tree type = TREE_TYPE (TREE_TYPE (t));
13360 tree sub = fold_indirect_ref_1 (type, t);
13365 return build1 (INDIRECT_REF, type, t);
13368 /* Given an INDIRECT_REF T, return either T or a simplified version. */
13371 fold_indirect_ref (tree t)
13373 tree sub = fold_indirect_ref_1 (TREE_TYPE (t), TREE_OPERAND (t, 0));
13381 /* Strip non-trapping, non-side-effecting tree nodes from an expression
13382 whose result is ignored. The type of the returned tree need not be
13383 the same as the original expression. */
13386 fold_ignored_result (tree t)
13388 if (!TREE_SIDE_EFFECTS (t))
13389 return integer_zero_node;
13392 switch (TREE_CODE_CLASS (TREE_CODE (t)))
13395 t = TREE_OPERAND (t, 0);
13399 case tcc_comparison:
13400 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
13401 t = TREE_OPERAND (t, 0);
13402 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
13403 t = TREE_OPERAND (t, 1);
13408 case tcc_expression:
13409 switch (TREE_CODE (t))
13411 case COMPOUND_EXPR:
13412 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
13414 t = TREE_OPERAND (t, 0);
13418 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
13419 || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
13421 t = TREE_OPERAND (t, 0);
13434 /* Return the value of VALUE, rounded up to a multiple of DIVISOR.
13435 This can only be applied to objects of a sizetype. */
13438 round_up (tree value, int divisor)
13440 tree div = NULL_TREE;
13442 gcc_assert (divisor > 0);
13446 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
13447 have to do anything. Only do this when we are not given a const,
13448 because in that case, this check is more expensive than just
13450 if (TREE_CODE (value) != INTEGER_CST)
13452 div = build_int_cst (TREE_TYPE (value), divisor);
13454 if (multiple_of_p (TREE_TYPE (value), value, div))
13458 /* If divisor is a power of two, simplify this to bit manipulation. */
13459 if (divisor == (divisor & -divisor))
13463 t = build_int_cst (TREE_TYPE (value), divisor - 1);
13464 value = size_binop (PLUS_EXPR, value, t);
13465 t = build_int_cst (TREE_TYPE (value), -divisor);
13466 value = size_binop (BIT_AND_EXPR, value, t);
13471 div = build_int_cst (TREE_TYPE (value), divisor);
13472 value = size_binop (CEIL_DIV_EXPR, value, div);
13473 value = size_binop (MULT_EXPR, value, div);
13479 /* Likewise, but round down. */
13482 round_down (tree value, int divisor)
13484 tree div = NULL_TREE;
13486 gcc_assert (divisor > 0);
13490 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
13491 have to do anything. Only do this when we are not given a const,
13492 because in that case, this check is more expensive than just
13494 if (TREE_CODE (value) != INTEGER_CST)
13496 div = build_int_cst (TREE_TYPE (value), divisor);
13498 if (multiple_of_p (TREE_TYPE (value), value, div))
13502 /* If divisor is a power of two, simplify this to bit manipulation. */
13503 if (divisor == (divisor & -divisor))
13507 t = build_int_cst (TREE_TYPE (value), -divisor);
13508 value = size_binop (BIT_AND_EXPR, value, t);
13513 div = build_int_cst (TREE_TYPE (value), divisor);
13514 value = size_binop (FLOOR_DIV_EXPR, value, div);
13515 value = size_binop (MULT_EXPR, value, div);
13521 /* Returns the pointer to the base of the object addressed by EXP and
13522 extracts the information about the offset of the access, storing it
13523 to PBITPOS and POFFSET. */
13526 split_address_to_core_and_offset (tree exp,
13527 HOST_WIDE_INT *pbitpos, tree *poffset)
13530 enum machine_mode mode;
13531 int unsignedp, volatilep;
13532 HOST_WIDE_INT bitsize;
13534 if (TREE_CODE (exp) == ADDR_EXPR)
13536 core = get_inner_reference (TREE_OPERAND (exp, 0), &bitsize, pbitpos,
13537 poffset, &mode, &unsignedp, &volatilep,
13539 core = build_fold_addr_expr (core);
13545 *poffset = NULL_TREE;
13551 /* Returns true if addresses of E1 and E2 differ by a constant, false
13552 otherwise. If they do, E1 - E2 is stored in *DIFF. */
13555 ptr_difference_const (tree e1, tree e2, HOST_WIDE_INT *diff)
13558 HOST_WIDE_INT bitpos1, bitpos2;
13559 tree toffset1, toffset2, tdiff, type;
13561 core1 = split_address_to_core_and_offset (e1, &bitpos1, &toffset1);
13562 core2 = split_address_to_core_and_offset (e2, &bitpos2, &toffset2);
13564 if (bitpos1 % BITS_PER_UNIT != 0
13565 || bitpos2 % BITS_PER_UNIT != 0
13566 || !operand_equal_p (core1, core2, 0))
13569 if (toffset1 && toffset2)
13571 type = TREE_TYPE (toffset1);
13572 if (type != TREE_TYPE (toffset2))
13573 toffset2 = fold_convert (type, toffset2);
13575 tdiff = fold_build2 (MINUS_EXPR, type, toffset1, toffset2);
13576 if (!cst_and_fits_in_hwi (tdiff))
13579 *diff = int_cst_value (tdiff);
13581 else if (toffset1 || toffset2)
13583 /* If only one of the offsets is non-constant, the difference cannot
13590 *diff += (bitpos1 - bitpos2) / BITS_PER_UNIT;
13594 /* Simplify the floating point expression EXP when the sign of the
13595 result is not significant. Return NULL_TREE if no simplification
13599 fold_strip_sign_ops (tree exp)
13603 switch (TREE_CODE (exp))
13607 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
13608 return arg0 ? arg0 : TREE_OPERAND (exp, 0);
13612 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (exp))))
13614 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
13615 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
13616 if (arg0 != NULL_TREE || arg1 != NULL_TREE)
13617 return fold_build2 (TREE_CODE (exp), TREE_TYPE (exp),
13618 arg0 ? arg0 : TREE_OPERAND (exp, 0),
13619 arg1 ? arg1 : TREE_OPERAND (exp, 1));