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, shorter_type);
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 || (TREE_CODE (arg1_unw) == INTEGER_CST
6667 && (TREE_CODE (shorter_type) == INTEGER_TYPE
6668 || TREE_CODE (shorter_type) == BOOLEAN_TYPE)
6669 && int_fits_type_p (arg1_unw, shorter_type))))
6670 return fold_build2 (code, type, arg0_unw,
6671 fold_convert (shorter_type, arg1_unw));
6673 if (TREE_CODE (arg1_unw) != INTEGER_CST
6674 || TREE_CODE (shorter_type) != INTEGER_TYPE
6675 || !int_fits_type_p (arg1_unw, shorter_type))
6678 /* If we are comparing with the integer that does not fit into the range
6679 of the shorter type, the result is known. */
6680 outer_type = TREE_TYPE (arg1_unw);
6681 min = lower_bound_in_type (outer_type, shorter_type);
6682 max = upper_bound_in_type (outer_type, shorter_type);
6684 above = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6686 below = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6693 return omit_one_operand (type, integer_zero_node, arg0);
6698 return omit_one_operand (type, integer_one_node, arg0);
6704 return omit_one_operand (type, integer_one_node, arg0);
6706 return omit_one_operand (type, integer_zero_node, arg0);
6711 return omit_one_operand (type, integer_zero_node, arg0);
6713 return omit_one_operand (type, integer_one_node, arg0);
6722 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where for
6723 ARG0 just the signedness is changed. */
6726 fold_sign_changed_comparison (enum tree_code code, tree type,
6727 tree arg0, tree arg1)
6729 tree arg0_inner, tmp;
6730 tree inner_type, outer_type;
6732 if (TREE_CODE (arg0) != NOP_EXPR
6733 && TREE_CODE (arg0) != CONVERT_EXPR)
6736 outer_type = TREE_TYPE (arg0);
6737 arg0_inner = TREE_OPERAND (arg0, 0);
6738 inner_type = TREE_TYPE (arg0_inner);
6740 #ifdef HAVE_canonicalize_funcptr_for_compare
6741 /* Disable this optimization if we're casting a function pointer
6742 type on targets that require function pointer canonicalization. */
6743 if (HAVE_canonicalize_funcptr_for_compare
6744 && TREE_CODE (inner_type) == POINTER_TYPE
6745 && TREE_CODE (TREE_TYPE (inner_type)) == FUNCTION_TYPE)
6749 if (TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
6752 if (TREE_CODE (arg1) != INTEGER_CST
6753 && !((TREE_CODE (arg1) == NOP_EXPR
6754 || TREE_CODE (arg1) == CONVERT_EXPR)
6755 && TREE_TYPE (TREE_OPERAND (arg1, 0)) == inner_type))
6758 if (TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
6763 if (TREE_CODE (arg1) == INTEGER_CST)
6765 tmp = build_int_cst_wide (inner_type,
6766 TREE_INT_CST_LOW (arg1),
6767 TREE_INT_CST_HIGH (arg1));
6768 arg1 = force_fit_type (tmp, 0,
6769 TREE_OVERFLOW (arg1),
6770 TREE_CONSTANT_OVERFLOW (arg1));
6773 arg1 = fold_convert (inner_type, arg1);
6775 return fold_build2 (code, type, arg0_inner, arg1);
6778 /* Tries to replace &a[idx] CODE s * delta with &a[idx CODE delta], if s is
6779 step of the array. Reconstructs s and delta in the case of s * delta
6780 being an integer constant (and thus already folded).
6781 ADDR is the address. MULT is the multiplicative expression.
6782 If the function succeeds, the new address expression is returned. Otherwise
6783 NULL_TREE is returned. */
6786 try_move_mult_to_index (enum tree_code code, tree addr, tree op1)
6788 tree s, delta, step;
6789 tree ref = TREE_OPERAND (addr, 0), pref;
6793 /* Canonicalize op1 into a possibly non-constant delta
6794 and an INTEGER_CST s. */
6795 if (TREE_CODE (op1) == MULT_EXPR)
6797 tree arg0 = TREE_OPERAND (op1, 0), arg1 = TREE_OPERAND (op1, 1);
6802 if (TREE_CODE (arg0) == INTEGER_CST)
6807 else if (TREE_CODE (arg1) == INTEGER_CST)
6815 else if (TREE_CODE (op1) == INTEGER_CST)
6822 /* Simulate we are delta * 1. */
6824 s = integer_one_node;
6827 for (;; ref = TREE_OPERAND (ref, 0))
6829 if (TREE_CODE (ref) == ARRAY_REF)
6831 itype = TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (ref, 0)));
6835 step = array_ref_element_size (ref);
6836 if (TREE_CODE (step) != INTEGER_CST)
6841 if (! tree_int_cst_equal (step, s))
6846 /* Try if delta is a multiple of step. */
6847 tree tmp = div_if_zero_remainder (EXACT_DIV_EXPR, delta, step);
6856 if (!handled_component_p (ref))
6860 /* We found the suitable array reference. So copy everything up to it,
6861 and replace the index. */
6863 pref = TREE_OPERAND (addr, 0);
6864 ret = copy_node (pref);
6869 pref = TREE_OPERAND (pref, 0);
6870 TREE_OPERAND (pos, 0) = copy_node (pref);
6871 pos = TREE_OPERAND (pos, 0);
6874 TREE_OPERAND (pos, 1) = fold_build2 (code, itype,
6875 fold_convert (itype,
6876 TREE_OPERAND (pos, 1)),
6877 fold_convert (itype, delta));
6879 return fold_build1 (ADDR_EXPR, TREE_TYPE (addr), ret);
6883 /* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
6884 means A >= Y && A != MAX, but in this case we know that
6885 A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
6888 fold_to_nonsharp_ineq_using_bound (tree ineq, tree bound)
6890 tree a, typea, type = TREE_TYPE (ineq), a1, diff, y;
6892 if (TREE_CODE (bound) == LT_EXPR)
6893 a = TREE_OPERAND (bound, 0);
6894 else if (TREE_CODE (bound) == GT_EXPR)
6895 a = TREE_OPERAND (bound, 1);
6899 typea = TREE_TYPE (a);
6900 if (!INTEGRAL_TYPE_P (typea)
6901 && !POINTER_TYPE_P (typea))
6904 if (TREE_CODE (ineq) == LT_EXPR)
6906 a1 = TREE_OPERAND (ineq, 1);
6907 y = TREE_OPERAND (ineq, 0);
6909 else if (TREE_CODE (ineq) == GT_EXPR)
6911 a1 = TREE_OPERAND (ineq, 0);
6912 y = TREE_OPERAND (ineq, 1);
6917 if (TREE_TYPE (a1) != typea)
6920 diff = fold_build2 (MINUS_EXPR, typea, a1, a);
6921 if (!integer_onep (diff))
6924 return fold_build2 (GE_EXPR, type, a, y);
6927 /* Fold a sum or difference of at least one multiplication.
6928 Returns the folded tree or NULL if no simplification could be made. */
6931 fold_plusminus_mult_expr (enum tree_code code, tree type, tree arg0, tree arg1)
6933 tree arg00, arg01, arg10, arg11;
6934 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
6936 /* (A * C) +- (B * C) -> (A+-B) * C.
6937 (A * C) +- A -> A * (C+-1).
6938 We are most concerned about the case where C is a constant,
6939 but other combinations show up during loop reduction. Since
6940 it is not difficult, try all four possibilities. */
6942 if (TREE_CODE (arg0) == MULT_EXPR)
6944 arg00 = TREE_OPERAND (arg0, 0);
6945 arg01 = TREE_OPERAND (arg0, 1);
6950 arg01 = build_one_cst (type);
6952 if (TREE_CODE (arg1) == MULT_EXPR)
6954 arg10 = TREE_OPERAND (arg1, 0);
6955 arg11 = TREE_OPERAND (arg1, 1);
6960 arg11 = build_one_cst (type);
6964 if (operand_equal_p (arg01, arg11, 0))
6965 same = arg01, alt0 = arg00, alt1 = arg10;
6966 else if (operand_equal_p (arg00, arg10, 0))
6967 same = arg00, alt0 = arg01, alt1 = arg11;
6968 else if (operand_equal_p (arg00, arg11, 0))
6969 same = arg00, alt0 = arg01, alt1 = arg10;
6970 else if (operand_equal_p (arg01, arg10, 0))
6971 same = arg01, alt0 = arg00, alt1 = arg11;
6973 /* No identical multiplicands; see if we can find a common
6974 power-of-two factor in non-power-of-two multiplies. This
6975 can help in multi-dimensional array access. */
6976 else if (host_integerp (arg01, 0)
6977 && host_integerp (arg11, 0))
6979 HOST_WIDE_INT int01, int11, tmp;
6982 int01 = TREE_INT_CST_LOW (arg01);
6983 int11 = TREE_INT_CST_LOW (arg11);
6985 /* Move min of absolute values to int11. */
6986 if ((int01 >= 0 ? int01 : -int01)
6987 < (int11 >= 0 ? int11 : -int11))
6989 tmp = int01, int01 = int11, int11 = tmp;
6990 alt0 = arg00, arg00 = arg10, arg10 = alt0;
6997 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
6999 alt0 = fold_build2 (MULT_EXPR, TREE_TYPE (arg00), arg00,
7000 build_int_cst (TREE_TYPE (arg00),
7005 maybe_same = alt0, alt0 = alt1, alt1 = maybe_same;
7010 return fold_build2 (MULT_EXPR, type,
7011 fold_build2 (code, type,
7012 fold_convert (type, alt0),
7013 fold_convert (type, alt1)),
7014 fold_convert (type, same));
7019 /* Subroutine of native_encode_expr. Encode the INTEGER_CST
7020 specified by EXPR into the buffer PTR of length LEN bytes.
7021 Return the number of bytes placed in the buffer, or zero
7025 native_encode_int (tree expr, unsigned char *ptr, int len)
7027 tree type = TREE_TYPE (expr);
7028 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7029 int byte, offset, word, words;
7030 unsigned char value;
7032 if (total_bytes > len)
7034 words = total_bytes / UNITS_PER_WORD;
7036 for (byte = 0; byte < total_bytes; byte++)
7038 int bitpos = byte * BITS_PER_UNIT;
7039 if (bitpos < HOST_BITS_PER_WIDE_INT)
7040 value = (unsigned char) (TREE_INT_CST_LOW (expr) >> bitpos);
7042 value = (unsigned char) (TREE_INT_CST_HIGH (expr)
7043 >> (bitpos - HOST_BITS_PER_WIDE_INT));
7045 if (total_bytes > UNITS_PER_WORD)
7047 word = byte / UNITS_PER_WORD;
7048 if (WORDS_BIG_ENDIAN)
7049 word = (words - 1) - word;
7050 offset = word * UNITS_PER_WORD;
7051 if (BYTES_BIG_ENDIAN)
7052 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7054 offset += byte % UNITS_PER_WORD;
7057 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7058 ptr[offset] = value;
7064 /* Subroutine of native_encode_expr. Encode the REAL_CST
7065 specified by EXPR into the buffer PTR of length LEN bytes.
7066 Return the number of bytes placed in the buffer, or zero
7070 native_encode_real (tree expr, unsigned char *ptr, int len)
7072 tree type = TREE_TYPE (expr);
7073 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7074 int byte, offset, word, words, bitpos;
7075 unsigned char value;
7077 /* There are always 32 bits in each long, no matter the size of
7078 the hosts long. We handle floating point representations with
7082 if (total_bytes > len)
7084 words = 32 / UNITS_PER_WORD;
7086 real_to_target (tmp, TREE_REAL_CST_PTR (expr), TYPE_MODE (type));
7088 for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7089 bitpos += BITS_PER_UNIT)
7091 byte = (bitpos / BITS_PER_UNIT) & 3;
7092 value = (unsigned char) (tmp[bitpos / 32] >> (bitpos & 31));
7094 if (UNITS_PER_WORD < 4)
7096 word = byte / UNITS_PER_WORD;
7097 if (WORDS_BIG_ENDIAN)
7098 word = (words - 1) - word;
7099 offset = word * UNITS_PER_WORD;
7100 if (BYTES_BIG_ENDIAN)
7101 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7103 offset += byte % UNITS_PER_WORD;
7106 offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
7107 ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)] = value;
7112 /* Subroutine of native_encode_expr. Encode the COMPLEX_CST
7113 specified by EXPR into the buffer PTR of length LEN bytes.
7114 Return the number of bytes placed in the buffer, or zero
7118 native_encode_complex (tree expr, unsigned char *ptr, int len)
7123 part = TREE_REALPART (expr);
7124 rsize = native_encode_expr (part, ptr, len);
7127 part = TREE_IMAGPART (expr);
7128 isize = native_encode_expr (part, ptr+rsize, len-rsize);
7131 return rsize + isize;
7135 /* Subroutine of native_encode_expr. Encode the VECTOR_CST
7136 specified by EXPR into the buffer PTR of length LEN bytes.
7137 Return the number of bytes placed in the buffer, or zero
7141 native_encode_vector (tree expr, unsigned char *ptr, int len)
7143 int i, size, offset, count;
7144 tree itype, elem, elements;
7147 elements = TREE_VECTOR_CST_ELTS (expr);
7148 count = TYPE_VECTOR_SUBPARTS (TREE_TYPE (expr));
7149 itype = TREE_TYPE (TREE_TYPE (expr));
7150 size = GET_MODE_SIZE (TYPE_MODE (itype));
7151 for (i = 0; i < count; i++)
7155 elem = TREE_VALUE (elements);
7156 elements = TREE_CHAIN (elements);
7163 if (native_encode_expr (elem, ptr+offset, len-offset) != size)
7168 if (offset + size > len)
7170 memset (ptr+offset, 0, size);
7178 /* Subroutine of fold_view_convert_expr. Encode the INTEGER_CST,
7179 REAL_CST, COMPLEX_CST or VECTOR_CST specified by EXPR into the
7180 buffer PTR of length LEN bytes. Return the number of bytes
7181 placed in the buffer, or zero upon failure. */
7184 native_encode_expr (tree expr, unsigned char *ptr, int len)
7186 switch (TREE_CODE (expr))
7189 return native_encode_int (expr, ptr, len);
7192 return native_encode_real (expr, ptr, len);
7195 return native_encode_complex (expr, ptr, len);
7198 return native_encode_vector (expr, ptr, len);
7206 /* Subroutine of native_interpret_expr. Interpret the contents of
7207 the buffer PTR of length LEN as an INTEGER_CST of type TYPE.
7208 If the buffer cannot be interpreted, return NULL_TREE. */
7211 native_interpret_int (tree type, unsigned char *ptr, int len)
7213 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7214 int byte, offset, word, words;
7215 unsigned char value;
7216 unsigned int HOST_WIDE_INT lo = 0;
7217 HOST_WIDE_INT hi = 0;
7219 if (total_bytes > len)
7221 if (total_bytes * BITS_PER_UNIT > 2 * HOST_BITS_PER_WIDE_INT)
7223 words = total_bytes / UNITS_PER_WORD;
7225 for (byte = 0; byte < total_bytes; byte++)
7227 int bitpos = byte * BITS_PER_UNIT;
7228 if (total_bytes > UNITS_PER_WORD)
7230 word = byte / UNITS_PER_WORD;
7231 if (WORDS_BIG_ENDIAN)
7232 word = (words - 1) - word;
7233 offset = word * UNITS_PER_WORD;
7234 if (BYTES_BIG_ENDIAN)
7235 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7237 offset += byte % UNITS_PER_WORD;
7240 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7241 value = ptr[offset];
7243 if (bitpos < HOST_BITS_PER_WIDE_INT)
7244 lo |= (unsigned HOST_WIDE_INT) value << bitpos;
7246 hi |= (unsigned HOST_WIDE_INT) value
7247 << (bitpos - HOST_BITS_PER_WIDE_INT);
7250 return force_fit_type (build_int_cst_wide (type, lo, hi),
7255 /* Subroutine of native_interpret_expr. Interpret the contents of
7256 the buffer PTR of length LEN as a REAL_CST of type TYPE.
7257 If the buffer cannot be interpreted, return NULL_TREE. */
7260 native_interpret_real (tree type, unsigned char *ptr, int len)
7262 enum machine_mode mode = TYPE_MODE (type);
7263 int total_bytes = GET_MODE_SIZE (mode);
7264 int byte, offset, word, words, bitpos;
7265 unsigned char value;
7266 /* There are always 32 bits in each long, no matter the size of
7267 the hosts long. We handle floating point representations with
7272 total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7273 if (total_bytes > len || total_bytes > 24)
7275 words = 32 / UNITS_PER_WORD;
7277 memset (tmp, 0, sizeof (tmp));
7278 for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7279 bitpos += BITS_PER_UNIT)
7281 byte = (bitpos / BITS_PER_UNIT) & 3;
7282 if (UNITS_PER_WORD < 4)
7284 word = byte / UNITS_PER_WORD;
7285 if (WORDS_BIG_ENDIAN)
7286 word = (words - 1) - word;
7287 offset = word * UNITS_PER_WORD;
7288 if (BYTES_BIG_ENDIAN)
7289 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7291 offset += byte % UNITS_PER_WORD;
7294 offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
7295 value = ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)];
7297 tmp[bitpos / 32] |= (unsigned long)value << (bitpos & 31);
7300 real_from_target (&r, tmp, mode);
7301 return build_real (type, r);
7305 /* Subroutine of native_interpret_expr. Interpret the contents of
7306 the buffer PTR of length LEN as a COMPLEX_CST of type TYPE.
7307 If the buffer cannot be interpreted, return NULL_TREE. */
7310 native_interpret_complex (tree type, unsigned char *ptr, int len)
7312 tree etype, rpart, ipart;
7315 etype = TREE_TYPE (type);
7316 size = GET_MODE_SIZE (TYPE_MODE (etype));
7319 rpart = native_interpret_expr (etype, ptr, size);
7322 ipart = native_interpret_expr (etype, ptr+size, size);
7325 return build_complex (type, rpart, ipart);
7329 /* Subroutine of native_interpret_expr. Interpret the contents of
7330 the buffer PTR of length LEN as a VECTOR_CST of type TYPE.
7331 If the buffer cannot be interpreted, return NULL_TREE. */
7334 native_interpret_vector (tree type, unsigned char *ptr, int len)
7336 tree etype, elem, elements;
7339 etype = TREE_TYPE (type);
7340 size = GET_MODE_SIZE (TYPE_MODE (etype));
7341 count = TYPE_VECTOR_SUBPARTS (type);
7342 if (size * count > len)
7345 elements = NULL_TREE;
7346 for (i = count - 1; i >= 0; i--)
7348 elem = native_interpret_expr (etype, ptr+(i*size), size);
7351 elements = tree_cons (NULL_TREE, elem, elements);
7353 return build_vector (type, elements);
7357 /* Subroutine of fold_view_convert_expr. Interpret the contents of
7358 the buffer PTR of length LEN as a constant of type TYPE. For
7359 INTEGRAL_TYPE_P we return an INTEGER_CST, for SCALAR_FLOAT_TYPE_P
7360 we return a REAL_CST, etc... If the buffer cannot be interpreted,
7361 return NULL_TREE. */
7364 native_interpret_expr (tree type, unsigned char *ptr, int len)
7366 switch (TREE_CODE (type))
7371 return native_interpret_int (type, ptr, len);
7374 return native_interpret_real (type, ptr, len);
7377 return native_interpret_complex (type, ptr, len);
7380 return native_interpret_vector (type, ptr, len);
7388 /* Fold a VIEW_CONVERT_EXPR of a constant expression EXPR to type
7389 TYPE at compile-time. If we're unable to perform the conversion
7390 return NULL_TREE. */
7393 fold_view_convert_expr (tree type, tree expr)
7395 /* We support up to 512-bit values (for V8DFmode). */
7396 unsigned char buffer[64];
7399 /* Check that the host and target are sane. */
7400 if (CHAR_BIT != 8 || BITS_PER_UNIT != 8)
7403 len = native_encode_expr (expr, buffer, sizeof (buffer));
7407 return native_interpret_expr (type, buffer, len);
7411 /* Fold a unary expression of code CODE and type TYPE with operand
7412 OP0. Return the folded expression if folding is successful.
7413 Otherwise, return NULL_TREE. */
7416 fold_unary (enum tree_code code, tree type, tree op0)
7420 enum tree_code_class kind = TREE_CODE_CLASS (code);
7422 gcc_assert (IS_EXPR_CODE_CLASS (kind)
7423 && TREE_CODE_LENGTH (code) == 1);
7428 if (code == NOP_EXPR || code == CONVERT_EXPR
7429 || code == FLOAT_EXPR || code == ABS_EXPR)
7431 /* Don't use STRIP_NOPS, because signedness of argument type
7433 STRIP_SIGN_NOPS (arg0);
7437 /* Strip any conversions that don't change the mode. This
7438 is safe for every expression, except for a comparison
7439 expression because its signedness is derived from its
7442 Note that this is done as an internal manipulation within
7443 the constant folder, in order to find the simplest
7444 representation of the arguments so that their form can be
7445 studied. In any cases, the appropriate type conversions
7446 should be put back in the tree that will get out of the
7452 if (TREE_CODE_CLASS (code) == tcc_unary)
7454 if (TREE_CODE (arg0) == COMPOUND_EXPR)
7455 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
7456 fold_build1 (code, type, TREE_OPERAND (arg0, 1)));
7457 else if (TREE_CODE (arg0) == COND_EXPR)
7459 tree arg01 = TREE_OPERAND (arg0, 1);
7460 tree arg02 = TREE_OPERAND (arg0, 2);
7461 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
7462 arg01 = fold_build1 (code, type, arg01);
7463 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
7464 arg02 = fold_build1 (code, type, arg02);
7465 tem = fold_build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
7468 /* If this was a conversion, and all we did was to move into
7469 inside the COND_EXPR, bring it back out. But leave it if
7470 it is a conversion from integer to integer and the
7471 result precision is no wider than a word since such a
7472 conversion is cheap and may be optimized away by combine,
7473 while it couldn't if it were outside the COND_EXPR. Then return
7474 so we don't get into an infinite recursion loop taking the
7475 conversion out and then back in. */
7477 if ((code == NOP_EXPR || code == CONVERT_EXPR
7478 || code == NON_LVALUE_EXPR)
7479 && TREE_CODE (tem) == COND_EXPR
7480 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
7481 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
7482 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
7483 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
7484 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
7485 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
7486 && (! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
7488 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
7489 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD)
7490 || flag_syntax_only))
7491 tem = build1 (code, type,
7493 TREE_TYPE (TREE_OPERAND
7494 (TREE_OPERAND (tem, 1), 0)),
7495 TREE_OPERAND (tem, 0),
7496 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
7497 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
7500 else if (COMPARISON_CLASS_P (arg0))
7502 if (TREE_CODE (type) == BOOLEAN_TYPE)
7504 arg0 = copy_node (arg0);
7505 TREE_TYPE (arg0) = type;
7508 else if (TREE_CODE (type) != INTEGER_TYPE)
7509 return fold_build3 (COND_EXPR, type, arg0,
7510 fold_build1 (code, type,
7512 fold_build1 (code, type,
7513 integer_zero_node));
7522 case FIX_TRUNC_EXPR:
7524 case FIX_FLOOR_EXPR:
7525 case FIX_ROUND_EXPR:
7526 if (TREE_TYPE (op0) == type)
7529 /* If we have (type) (a CMP b) and type is an integral type, return
7530 new expression involving the new type. */
7531 if (COMPARISON_CLASS_P (op0) && INTEGRAL_TYPE_P (type))
7532 return fold_build2 (TREE_CODE (op0), type, TREE_OPERAND (op0, 0),
7533 TREE_OPERAND (op0, 1));
7535 /* Handle cases of two conversions in a row. */
7536 if (TREE_CODE (op0) == NOP_EXPR
7537 || TREE_CODE (op0) == CONVERT_EXPR)
7539 tree inside_type = TREE_TYPE (TREE_OPERAND (op0, 0));
7540 tree inter_type = TREE_TYPE (op0);
7541 int inside_int = INTEGRAL_TYPE_P (inside_type);
7542 int inside_ptr = POINTER_TYPE_P (inside_type);
7543 int inside_float = FLOAT_TYPE_P (inside_type);
7544 int inside_vec = TREE_CODE (inside_type) == VECTOR_TYPE;
7545 unsigned int inside_prec = TYPE_PRECISION (inside_type);
7546 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
7547 int inter_int = INTEGRAL_TYPE_P (inter_type);
7548 int inter_ptr = POINTER_TYPE_P (inter_type);
7549 int inter_float = FLOAT_TYPE_P (inter_type);
7550 int inter_vec = TREE_CODE (inter_type) == VECTOR_TYPE;
7551 unsigned int inter_prec = TYPE_PRECISION (inter_type);
7552 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
7553 int final_int = INTEGRAL_TYPE_P (type);
7554 int final_ptr = POINTER_TYPE_P (type);
7555 int final_float = FLOAT_TYPE_P (type);
7556 int final_vec = TREE_CODE (type) == VECTOR_TYPE;
7557 unsigned int final_prec = TYPE_PRECISION (type);
7558 int final_unsignedp = TYPE_UNSIGNED (type);
7560 /* In addition to the cases of two conversions in a row
7561 handled below, if we are converting something to its own
7562 type via an object of identical or wider precision, neither
7563 conversion is needed. */
7564 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
7565 && (((inter_int || inter_ptr) && final_int)
7566 || (inter_float && final_float))
7567 && inter_prec >= final_prec)
7568 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7570 /* Likewise, if the intermediate and final types are either both
7571 float or both integer, we don't need the middle conversion if
7572 it is wider than the final type and doesn't change the signedness
7573 (for integers). Avoid this if the final type is a pointer
7574 since then we sometimes need the inner conversion. Likewise if
7575 the outer has a precision not equal to the size of its mode. */
7576 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
7577 || (inter_float && inside_float)
7578 || (inter_vec && inside_vec))
7579 && inter_prec >= inside_prec
7580 && (inter_float || inter_vec
7581 || inter_unsignedp == inside_unsignedp)
7582 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
7583 && TYPE_MODE (type) == TYPE_MODE (inter_type))
7585 && (! final_vec || inter_prec == inside_prec))
7586 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7588 /* If we have a sign-extension of a zero-extended value, we can
7589 replace that by a single zero-extension. */
7590 if (inside_int && inter_int && final_int
7591 && inside_prec < inter_prec && inter_prec < final_prec
7592 && inside_unsignedp && !inter_unsignedp)
7593 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7595 /* Two conversions in a row are not needed unless:
7596 - some conversion is floating-point (overstrict for now), or
7597 - some conversion is a vector (overstrict for now), or
7598 - the intermediate type is narrower than both initial and
7600 - the intermediate type and innermost type differ in signedness,
7601 and the outermost type is wider than the intermediate, or
7602 - the initial type is a pointer type and the precisions of the
7603 intermediate and final types differ, or
7604 - the final type is a pointer type and the precisions of the
7605 initial and intermediate types differ.
7606 - the final type is a pointer type and the initial type not
7607 - the initial type is a pointer to an array and the final type
7609 /* Java pointer type conversions generate checks in some
7610 cases, so we explicitly disallow this optimization. */
7611 if (! inside_float && ! inter_float && ! final_float
7612 && ! inside_vec && ! inter_vec && ! final_vec
7613 && (inter_prec >= inside_prec || inter_prec >= final_prec)
7614 && ! (inside_int && inter_int
7615 && inter_unsignedp != inside_unsignedp
7616 && inter_prec < final_prec)
7617 && ((inter_unsignedp && inter_prec > inside_prec)
7618 == (final_unsignedp && final_prec > inter_prec))
7619 && ! (inside_ptr && inter_prec != final_prec)
7620 && ! (final_ptr && inside_prec != inter_prec)
7621 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
7622 && TYPE_MODE (type) == TYPE_MODE (inter_type))
7623 && final_ptr == inside_ptr
7625 && TREE_CODE (TREE_TYPE (inside_type)) == ARRAY_TYPE
7626 && TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE)
7627 && ! ((strcmp (lang_hooks.name, "GNU Java") == 0)
7629 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7632 /* Handle (T *)&A.B.C for A being of type T and B and C
7633 living at offset zero. This occurs frequently in
7634 C++ upcasting and then accessing the base. */
7635 if (TREE_CODE (op0) == ADDR_EXPR
7636 && POINTER_TYPE_P (type)
7637 && handled_component_p (TREE_OPERAND (op0, 0)))
7639 HOST_WIDE_INT bitsize, bitpos;
7641 enum machine_mode mode;
7642 int unsignedp, volatilep;
7643 tree base = TREE_OPERAND (op0, 0);
7644 base = get_inner_reference (base, &bitsize, &bitpos, &offset,
7645 &mode, &unsignedp, &volatilep, false);
7646 /* If the reference was to a (constant) zero offset, we can use
7647 the address of the base if it has the same base type
7648 as the result type. */
7649 if (! offset && bitpos == 0
7650 && TYPE_MAIN_VARIANT (TREE_TYPE (type))
7651 == TYPE_MAIN_VARIANT (TREE_TYPE (base)))
7652 return fold_convert (type, build_fold_addr_expr (base));
7655 if (TREE_CODE (op0) == MODIFY_EXPR
7656 && TREE_CONSTANT (TREE_OPERAND (op0, 1))
7657 /* Detect assigning a bitfield. */
7658 && !(TREE_CODE (TREE_OPERAND (op0, 0)) == COMPONENT_REF
7659 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (op0, 0), 1))))
7661 /* Don't leave an assignment inside a conversion
7662 unless assigning a bitfield. */
7663 tem = fold_build1 (code, type, TREE_OPERAND (op0, 1));
7664 /* First do the assignment, then return converted constant. */
7665 tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), op0, tem);
7666 TREE_NO_WARNING (tem) = 1;
7667 TREE_USED (tem) = 1;
7671 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
7672 constants (if x has signed type, the sign bit cannot be set
7673 in c). This folds extension into the BIT_AND_EXPR. */
7674 if (INTEGRAL_TYPE_P (type)
7675 && TREE_CODE (type) != BOOLEAN_TYPE
7676 && TREE_CODE (op0) == BIT_AND_EXPR
7677 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
7680 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
7683 if (TYPE_UNSIGNED (TREE_TYPE (and))
7684 || (TYPE_PRECISION (type)
7685 <= TYPE_PRECISION (TREE_TYPE (and))))
7687 else if (TYPE_PRECISION (TREE_TYPE (and1))
7688 <= HOST_BITS_PER_WIDE_INT
7689 && host_integerp (and1, 1))
7691 unsigned HOST_WIDE_INT cst;
7693 cst = tree_low_cst (and1, 1);
7694 cst &= (HOST_WIDE_INT) -1
7695 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
7696 change = (cst == 0);
7697 #ifdef LOAD_EXTEND_OP
7699 && !flag_syntax_only
7700 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
7703 tree uns = lang_hooks.types.unsigned_type (TREE_TYPE (and0));
7704 and0 = fold_convert (uns, and0);
7705 and1 = fold_convert (uns, and1);
7711 tem = build_int_cst_wide (type, TREE_INT_CST_LOW (and1),
7712 TREE_INT_CST_HIGH (and1));
7713 tem = force_fit_type (tem, 0, TREE_OVERFLOW (and1),
7714 TREE_CONSTANT_OVERFLOW (and1));
7715 return fold_build2 (BIT_AND_EXPR, type,
7716 fold_convert (type, and0), tem);
7720 /* Convert (T1)((T2)X op Y) into (T1)X op Y, for pointer types T1 and
7721 T2 being pointers to types of the same size. */
7722 if (POINTER_TYPE_P (type)
7723 && BINARY_CLASS_P (arg0)
7724 && TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
7725 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0))))
7727 tree arg00 = TREE_OPERAND (arg0, 0);
7729 tree t1 = TREE_TYPE (arg00);
7730 tree tt0 = TREE_TYPE (t0);
7731 tree tt1 = TREE_TYPE (t1);
7732 tree s0 = TYPE_SIZE (tt0);
7733 tree s1 = TYPE_SIZE (tt1);
7735 if (s0 && s1 && operand_equal_p (s0, s1, OEP_ONLY_CONST))
7736 return build2 (TREE_CODE (arg0), t0, fold_convert (t0, arg00),
7737 TREE_OPERAND (arg0, 1));
7740 /* Convert (T1)(~(T2)X) into ~(T1)X if T1 and T2 are integral types
7741 of the same precision, and X is a integer type not narrower than
7742 types T1 or T2, i.e. the cast (T2)X isn't an extension. */
7743 if (INTEGRAL_TYPE_P (type)
7744 && TREE_CODE (op0) == BIT_NOT_EXPR
7745 && INTEGRAL_TYPE_P (TREE_TYPE (op0))
7746 && (TREE_CODE (TREE_OPERAND (op0, 0)) == NOP_EXPR
7747 || TREE_CODE (TREE_OPERAND (op0, 0)) == CONVERT_EXPR)
7748 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0)))
7750 tem = TREE_OPERAND (TREE_OPERAND (op0, 0), 0);
7751 if (INTEGRAL_TYPE_P (TREE_TYPE (tem))
7752 && TYPE_PRECISION (type) <= TYPE_PRECISION (TREE_TYPE (tem)))
7753 return fold_build1 (BIT_NOT_EXPR, type, fold_convert (type, tem));
7756 tem = fold_convert_const (code, type, op0);
7757 return tem ? tem : NULL_TREE;
7759 case VIEW_CONVERT_EXPR:
7760 if (TREE_CODE (op0) == VIEW_CONVERT_EXPR)
7761 return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
7762 return fold_view_convert_expr (type, op0);
7765 tem = fold_negate_expr (arg0);
7767 return fold_convert (type, tem);
7771 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
7772 return fold_abs_const (arg0, type);
7773 else if (TREE_CODE (arg0) == NEGATE_EXPR)
7774 return fold_build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
7775 /* Convert fabs((double)float) into (double)fabsf(float). */
7776 else if (TREE_CODE (arg0) == NOP_EXPR
7777 && TREE_CODE (type) == REAL_TYPE)
7779 tree targ0 = strip_float_extensions (arg0);
7781 return fold_convert (type, fold_build1 (ABS_EXPR,
7785 /* ABS_EXPR<ABS_EXPR<x>> = ABS_EXPR<x> even if flag_wrapv is on. */
7786 else if (TREE_CODE (arg0) == ABS_EXPR)
7788 else if (tree_expr_nonnegative_p (arg0))
7791 /* Strip sign ops from argument. */
7792 if (TREE_CODE (type) == REAL_TYPE)
7794 tem = fold_strip_sign_ops (arg0);
7796 return fold_build1 (ABS_EXPR, type, fold_convert (type, tem));
7801 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7802 return fold_convert (type, arg0);
7803 if (TREE_CODE (arg0) == COMPLEX_EXPR)
7805 tree itype = TREE_TYPE (type);
7806 tree rpart = fold_convert (itype, TREE_OPERAND (arg0, 0));
7807 tree ipart = fold_convert (itype, TREE_OPERAND (arg0, 1));
7808 return fold_build2 (COMPLEX_EXPR, type, rpart, negate_expr (ipart));
7810 if (TREE_CODE (arg0) == COMPLEX_CST)
7812 tree itype = TREE_TYPE (type);
7813 tree rpart = fold_convert (itype, TREE_REALPART (arg0));
7814 tree ipart = fold_convert (itype, TREE_IMAGPART (arg0));
7815 return build_complex (type, rpart, negate_expr (ipart));
7817 if (TREE_CODE (arg0) == CONJ_EXPR)
7818 return fold_convert (type, TREE_OPERAND (arg0, 0));
7822 if (TREE_CODE (arg0) == INTEGER_CST)
7823 return fold_not_const (arg0, type);
7824 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
7825 return TREE_OPERAND (arg0, 0);
7826 /* Convert ~ (-A) to A - 1. */
7827 else if (INTEGRAL_TYPE_P (type) && TREE_CODE (arg0) == NEGATE_EXPR)
7828 return fold_build2 (MINUS_EXPR, type, TREE_OPERAND (arg0, 0),
7829 build_int_cst (type, 1));
7830 /* Convert ~ (A - 1) or ~ (A + -1) to -A. */
7831 else if (INTEGRAL_TYPE_P (type)
7832 && ((TREE_CODE (arg0) == MINUS_EXPR
7833 && integer_onep (TREE_OPERAND (arg0, 1)))
7834 || (TREE_CODE (arg0) == PLUS_EXPR
7835 && integer_all_onesp (TREE_OPERAND (arg0, 1)))))
7836 return fold_build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0));
7837 /* Convert ~(X ^ Y) to ~X ^ Y or X ^ ~Y if ~X or ~Y simplify. */
7838 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
7839 && (tem = fold_unary (BIT_NOT_EXPR, type,
7841 TREE_OPERAND (arg0, 0)))))
7842 return fold_build2 (BIT_XOR_EXPR, type, tem,
7843 fold_convert (type, TREE_OPERAND (arg0, 1)));
7844 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
7845 && (tem = fold_unary (BIT_NOT_EXPR, type,
7847 TREE_OPERAND (arg0, 1)))))
7848 return fold_build2 (BIT_XOR_EXPR, type,
7849 fold_convert (type, TREE_OPERAND (arg0, 0)), tem);
7853 case TRUTH_NOT_EXPR:
7854 /* The argument to invert_truthvalue must have Boolean type. */
7855 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
7856 arg0 = fold_convert (boolean_type_node, arg0);
7858 /* Note that the operand of this must be an int
7859 and its values must be 0 or 1.
7860 ("true" is a fixed value perhaps depending on the language,
7861 but we don't handle values other than 1 correctly yet.) */
7862 tem = fold_truth_not_expr (arg0);
7865 return fold_convert (type, tem);
7868 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7869 return fold_convert (type, arg0);
7870 if (TREE_CODE (arg0) == COMPLEX_EXPR)
7871 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
7872 TREE_OPERAND (arg0, 1));
7873 if (TREE_CODE (arg0) == COMPLEX_CST)
7874 return fold_convert (type, TREE_REALPART (arg0));
7875 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7877 tree itype = TREE_TYPE (TREE_TYPE (arg0));
7878 tem = fold_build2 (TREE_CODE (arg0), itype,
7879 fold_build1 (REALPART_EXPR, itype,
7880 TREE_OPERAND (arg0, 0)),
7881 fold_build1 (REALPART_EXPR, itype,
7882 TREE_OPERAND (arg0, 1)));
7883 return fold_convert (type, tem);
7885 if (TREE_CODE (arg0) == CONJ_EXPR)
7887 tree itype = TREE_TYPE (TREE_TYPE (arg0));
7888 tem = fold_build1 (REALPART_EXPR, itype, TREE_OPERAND (arg0, 0));
7889 return fold_convert (type, tem);
7894 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7895 return fold_convert (type, integer_zero_node);
7896 if (TREE_CODE (arg0) == COMPLEX_EXPR)
7897 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
7898 TREE_OPERAND (arg0, 0));
7899 if (TREE_CODE (arg0) == COMPLEX_CST)
7900 return fold_convert (type, TREE_IMAGPART (arg0));
7901 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7903 tree itype = TREE_TYPE (TREE_TYPE (arg0));
7904 tem = fold_build2 (TREE_CODE (arg0), itype,
7905 fold_build1 (IMAGPART_EXPR, itype,
7906 TREE_OPERAND (arg0, 0)),
7907 fold_build1 (IMAGPART_EXPR, itype,
7908 TREE_OPERAND (arg0, 1)));
7909 return fold_convert (type, tem);
7911 if (TREE_CODE (arg0) == CONJ_EXPR)
7913 tree itype = TREE_TYPE (TREE_TYPE (arg0));
7914 tem = fold_build1 (IMAGPART_EXPR, itype, TREE_OPERAND (arg0, 0));
7915 return fold_convert (type, negate_expr (tem));
7921 } /* switch (code) */
7924 /* Fold a binary expression of code CODE and type TYPE with operands
7925 OP0 and OP1, containing either a MIN-MAX or a MAX-MIN combination.
7926 Return the folded expression if folding is successful. Otherwise,
7927 return NULL_TREE. */
7930 fold_minmax (enum tree_code code, tree type, tree op0, tree op1)
7932 enum tree_code compl_code;
7934 if (code == MIN_EXPR)
7935 compl_code = MAX_EXPR;
7936 else if (code == MAX_EXPR)
7937 compl_code = MIN_EXPR;
7941 /* MIN (MAX (a, b), b) == b. */
7942 if (TREE_CODE (op0) == compl_code
7943 && operand_equal_p (TREE_OPERAND (op0, 1), op1, 0))
7944 return omit_one_operand (type, op1, TREE_OPERAND (op0, 0));
7946 /* MIN (MAX (b, a), b) == b. */
7947 if (TREE_CODE (op0) == compl_code
7948 && operand_equal_p (TREE_OPERAND (op0, 0), op1, 0)
7949 && reorder_operands_p (TREE_OPERAND (op0, 1), op1))
7950 return omit_one_operand (type, op1, TREE_OPERAND (op0, 1));
7952 /* MIN (a, MAX (a, b)) == a. */
7953 if (TREE_CODE (op1) == compl_code
7954 && operand_equal_p (op0, TREE_OPERAND (op1, 0), 0)
7955 && reorder_operands_p (op0, TREE_OPERAND (op1, 1)))
7956 return omit_one_operand (type, op0, TREE_OPERAND (op1, 1));
7958 /* MIN (a, MAX (b, a)) == a. */
7959 if (TREE_CODE (op1) == compl_code
7960 && operand_equal_p (op0, TREE_OPERAND (op1, 1), 0)
7961 && reorder_operands_p (op0, TREE_OPERAND (op1, 0)))
7962 return omit_one_operand (type, op0, TREE_OPERAND (op1, 0));
7967 /* Subroutine of fold_binary. This routine performs all of the
7968 transformations that are common to the equality/inequality
7969 operators (EQ_EXPR and NE_EXPR) and the ordering operators
7970 (LT_EXPR, LE_EXPR, GE_EXPR and GT_EXPR). Callers other than
7971 fold_binary should call fold_binary. Fold a comparison with
7972 tree code CODE and type TYPE with operands OP0 and OP1. Return
7973 the folded comparison or NULL_TREE. */
7976 fold_comparison (enum tree_code code, tree type, tree op0, tree op1)
7978 tree arg0, arg1, tem;
7983 STRIP_SIGN_NOPS (arg0);
7984 STRIP_SIGN_NOPS (arg1);
7986 tem = fold_relational_const (code, type, arg0, arg1);
7987 if (tem != NULL_TREE)
7990 /* If one arg is a real or integer constant, put it last. */
7991 if (tree_swap_operands_p (arg0, arg1, true))
7992 return fold_build2 (swap_tree_comparison (code), type, op1, op0);
7994 /* Transform comparisons of the form X +- C1 CMP C2 to X CMP C2 +- C1. */
7995 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7996 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7997 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
7998 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
7999 && (TREE_CODE (arg1) == INTEGER_CST
8000 && !TREE_OVERFLOW (arg1)))
8002 tree const1 = TREE_OPERAND (arg0, 1);
8004 tree variable = TREE_OPERAND (arg0, 0);
8007 lhs_add = TREE_CODE (arg0) != PLUS_EXPR;
8009 lhs = fold_build2 (lhs_add ? PLUS_EXPR : MINUS_EXPR,
8010 TREE_TYPE (arg1), const2, const1);
8011 if (TREE_CODE (lhs) == TREE_CODE (arg1)
8012 && (TREE_CODE (lhs) != INTEGER_CST
8013 || !TREE_OVERFLOW (lhs)))
8015 fold_overflow_warning (("assuming signed overflow does not occur "
8016 "when changing X +- C1 cmp C2 to "
8018 WARN_STRICT_OVERFLOW_COMPARISON);
8019 return fold_build2 (code, type, variable, lhs);
8023 /* If this is a comparison of two exprs that look like an ARRAY_REF of the
8024 same object, then we can fold this to a comparison of the two offsets in
8025 signed size type. This is possible because pointer arithmetic is
8026 restricted to retain within an object and overflow on pointer differences
8027 is undefined as of 6.5.6/8 and /9 with respect to the signed ptrdiff_t.
8029 We check flag_wrapv directly because pointers types are unsigned,
8030 and therefore TYPE_OVERFLOW_WRAPS returns true for them. That is
8031 normally what we want to avoid certain odd overflow cases, but
8033 if (POINTER_TYPE_P (TREE_TYPE (arg0))
8035 && !TYPE_OVERFLOW_TRAPS (TREE_TYPE (arg0)))
8037 tree base0, offset0, base1, offset1;
8039 if (extract_array_ref (arg0, &base0, &offset0)
8040 && extract_array_ref (arg1, &base1, &offset1)
8041 && operand_equal_p (base0, base1, 0))
8043 tree signed_size_type_node;
8044 signed_size_type_node = signed_type_for (size_type_node);
8046 /* By converting to signed size type we cover middle-end pointer
8047 arithmetic which operates on unsigned pointer types of size
8048 type size and ARRAY_REF offsets which are properly sign or
8049 zero extended from their type in case it is narrower than
8051 if (offset0 == NULL_TREE)
8052 offset0 = build_int_cst (signed_size_type_node, 0);
8054 offset0 = fold_convert (signed_size_type_node, offset0);
8055 if (offset1 == NULL_TREE)
8056 offset1 = build_int_cst (signed_size_type_node, 0);
8058 offset1 = fold_convert (signed_size_type_node, offset1);
8060 return fold_build2 (code, type, offset0, offset1);
8064 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
8066 tree targ0 = strip_float_extensions (arg0);
8067 tree targ1 = strip_float_extensions (arg1);
8068 tree newtype = TREE_TYPE (targ0);
8070 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
8071 newtype = TREE_TYPE (targ1);
8073 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
8074 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
8075 return fold_build2 (code, type, fold_convert (newtype, targ0),
8076 fold_convert (newtype, targ1));
8078 /* (-a) CMP (-b) -> b CMP a */
8079 if (TREE_CODE (arg0) == NEGATE_EXPR
8080 && TREE_CODE (arg1) == NEGATE_EXPR)
8081 return fold_build2 (code, type, TREE_OPERAND (arg1, 0),
8082 TREE_OPERAND (arg0, 0));
8084 if (TREE_CODE (arg1) == REAL_CST)
8086 REAL_VALUE_TYPE cst;
8087 cst = TREE_REAL_CST (arg1);
8089 /* (-a) CMP CST -> a swap(CMP) (-CST) */
8090 if (TREE_CODE (arg0) == NEGATE_EXPR)
8091 return fold_build2 (swap_tree_comparison (code), type,
8092 TREE_OPERAND (arg0, 0),
8093 build_real (TREE_TYPE (arg1),
8094 REAL_VALUE_NEGATE (cst)));
8096 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
8097 /* a CMP (-0) -> a CMP 0 */
8098 if (REAL_VALUE_MINUS_ZERO (cst))
8099 return fold_build2 (code, type, arg0,
8100 build_real (TREE_TYPE (arg1), dconst0));
8102 /* x != NaN is always true, other ops are always false. */
8103 if (REAL_VALUE_ISNAN (cst)
8104 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
8106 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
8107 return omit_one_operand (type, tem, arg0);
8110 /* Fold comparisons against infinity. */
8111 if (REAL_VALUE_ISINF (cst))
8113 tem = fold_inf_compare (code, type, arg0, arg1);
8114 if (tem != NULL_TREE)
8119 /* If this is a comparison of a real constant with a PLUS_EXPR
8120 or a MINUS_EXPR of a real constant, we can convert it into a
8121 comparison with a revised real constant as long as no overflow
8122 occurs when unsafe_math_optimizations are enabled. */
8123 if (flag_unsafe_math_optimizations
8124 && TREE_CODE (arg1) == REAL_CST
8125 && (TREE_CODE (arg0) == PLUS_EXPR
8126 || TREE_CODE (arg0) == MINUS_EXPR)
8127 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
8128 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
8129 ? MINUS_EXPR : PLUS_EXPR,
8130 arg1, TREE_OPERAND (arg0, 1), 0))
8131 && ! TREE_CONSTANT_OVERFLOW (tem))
8132 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
8134 /* Likewise, we can simplify a comparison of a real constant with
8135 a MINUS_EXPR whose first operand is also a real constant, i.e.
8136 (c1 - x) < c2 becomes x > c1-c2. */
8137 if (flag_unsafe_math_optimizations
8138 && TREE_CODE (arg1) == REAL_CST
8139 && TREE_CODE (arg0) == MINUS_EXPR
8140 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
8141 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
8143 && ! TREE_CONSTANT_OVERFLOW (tem))
8144 return fold_build2 (swap_tree_comparison (code), type,
8145 TREE_OPERAND (arg0, 1), tem);
8147 /* Fold comparisons against built-in math functions. */
8148 if (TREE_CODE (arg1) == REAL_CST
8149 && flag_unsafe_math_optimizations
8150 && ! flag_errno_math)
8152 enum built_in_function fcode = builtin_mathfn_code (arg0);
8154 if (fcode != END_BUILTINS)
8156 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
8157 if (tem != NULL_TREE)
8163 /* Convert foo++ == CONST into ++foo == CONST + INCR. */
8164 if (TREE_CONSTANT (arg1)
8165 && (TREE_CODE (arg0) == POSTINCREMENT_EXPR
8166 || TREE_CODE (arg0) == POSTDECREMENT_EXPR)
8167 /* This optimization is invalid for ordered comparisons
8168 if CONST+INCR overflows or if foo+incr might overflow.
8169 This optimization is invalid for floating point due to rounding.
8170 For pointer types we assume overflow doesn't happen. */
8171 && (POINTER_TYPE_P (TREE_TYPE (arg0))
8172 || (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
8173 && (code == EQ_EXPR || code == NE_EXPR))))
8175 tree varop, newconst;
8177 if (TREE_CODE (arg0) == POSTINCREMENT_EXPR)
8179 newconst = fold_build2 (PLUS_EXPR, TREE_TYPE (arg0),
8180 arg1, TREE_OPERAND (arg0, 1));
8181 varop = build2 (PREINCREMENT_EXPR, TREE_TYPE (arg0),
8182 TREE_OPERAND (arg0, 0),
8183 TREE_OPERAND (arg0, 1));
8187 newconst = fold_build2 (MINUS_EXPR, TREE_TYPE (arg0),
8188 arg1, TREE_OPERAND (arg0, 1));
8189 varop = build2 (PREDECREMENT_EXPR, TREE_TYPE (arg0),
8190 TREE_OPERAND (arg0, 0),
8191 TREE_OPERAND (arg0, 1));
8195 /* If VAROP is a reference to a bitfield, we must mask
8196 the constant by the width of the field. */
8197 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
8198 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (varop, 0), 1))
8199 && host_integerp (DECL_SIZE (TREE_OPERAND
8200 (TREE_OPERAND (varop, 0), 1)), 1))
8202 tree fielddecl = TREE_OPERAND (TREE_OPERAND (varop, 0), 1);
8203 HOST_WIDE_INT size = tree_low_cst (DECL_SIZE (fielddecl), 1);
8204 tree folded_compare, shift;
8206 /* First check whether the comparison would come out
8207 always the same. If we don't do that we would
8208 change the meaning with the masking. */
8209 folded_compare = fold_build2 (code, type,
8210 TREE_OPERAND (varop, 0), arg1);
8211 if (TREE_CODE (folded_compare) == INTEGER_CST)
8212 return omit_one_operand (type, folded_compare, varop);
8214 shift = build_int_cst (NULL_TREE,
8215 TYPE_PRECISION (TREE_TYPE (varop)) - size);
8216 shift = fold_convert (TREE_TYPE (varop), shift);
8217 newconst = fold_build2 (LSHIFT_EXPR, TREE_TYPE (varop),
8219 newconst = fold_build2 (RSHIFT_EXPR, TREE_TYPE (varop),
8223 return fold_build2 (code, type, varop, newconst);
8226 if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
8227 && (TREE_CODE (arg0) == NOP_EXPR
8228 || TREE_CODE (arg0) == CONVERT_EXPR))
8230 /* If we are widening one operand of an integer comparison,
8231 see if the other operand is similarly being widened. Perhaps we
8232 can do the comparison in the narrower type. */
8233 tem = fold_widened_comparison (code, type, arg0, arg1);
8237 /* Or if we are changing signedness. */
8238 tem = fold_sign_changed_comparison (code, type, arg0, arg1);
8243 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
8244 constant, we can simplify it. */
8245 if (TREE_CODE (arg1) == INTEGER_CST
8246 && (TREE_CODE (arg0) == MIN_EXPR
8247 || TREE_CODE (arg0) == MAX_EXPR)
8248 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8250 tem = optimize_minmax_comparison (code, type, op0, op1);
8255 /* Simplify comparison of something with itself. (For IEEE
8256 floating-point, we can only do some of these simplifications.) */
8257 if (operand_equal_p (arg0, arg1, 0))
8262 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8263 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8264 return constant_boolean_node (1, type);
8269 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8270 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8271 return constant_boolean_node (1, type);
8272 return fold_build2 (EQ_EXPR, type, arg0, arg1);
8275 /* For NE, we can only do this simplification if integer
8276 or we don't honor IEEE floating point NaNs. */
8277 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
8278 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8280 /* ... fall through ... */
8283 return constant_boolean_node (0, type);
8289 /* If we are comparing an expression that just has comparisons
8290 of two integer values, arithmetic expressions of those comparisons,
8291 and constants, we can simplify it. There are only three cases
8292 to check: the two values can either be equal, the first can be
8293 greater, or the second can be greater. Fold the expression for
8294 those three values. Since each value must be 0 or 1, we have
8295 eight possibilities, each of which corresponds to the constant 0
8296 or 1 or one of the six possible comparisons.
8298 This handles common cases like (a > b) == 0 but also handles
8299 expressions like ((x > y) - (y > x)) > 0, which supposedly
8300 occur in macroized code. */
8302 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
8304 tree cval1 = 0, cval2 = 0;
8307 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
8308 /* Don't handle degenerate cases here; they should already
8309 have been handled anyway. */
8310 && cval1 != 0 && cval2 != 0
8311 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
8312 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
8313 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
8314 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
8315 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
8316 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
8317 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
8319 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
8320 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
8322 /* We can't just pass T to eval_subst in case cval1 or cval2
8323 was the same as ARG1. */
8326 = fold_build2 (code, type,
8327 eval_subst (arg0, cval1, maxval,
8331 = fold_build2 (code, type,
8332 eval_subst (arg0, cval1, maxval,
8336 = fold_build2 (code, type,
8337 eval_subst (arg0, cval1, minval,
8341 /* All three of these results should be 0 or 1. Confirm they are.
8342 Then use those values to select the proper code to use. */
8344 if (TREE_CODE (high_result) == INTEGER_CST
8345 && TREE_CODE (equal_result) == INTEGER_CST
8346 && TREE_CODE (low_result) == INTEGER_CST)
8348 /* Make a 3-bit mask with the high-order bit being the
8349 value for `>', the next for '=', and the low for '<'. */
8350 switch ((integer_onep (high_result) * 4)
8351 + (integer_onep (equal_result) * 2)
8352 + integer_onep (low_result))
8356 return omit_one_operand (type, integer_zero_node, arg0);
8377 return omit_one_operand (type, integer_one_node, arg0);
8381 return save_expr (build2 (code, type, cval1, cval2));
8382 return fold_build2 (code, type, cval1, cval2);
8387 /* Fold a comparison of the address of COMPONENT_REFs with the same
8388 type and component to a comparison of the address of the base
8389 object. In short, &x->a OP &y->a to x OP y and
8390 &x->a OP &y.a to x OP &y */
8391 if (TREE_CODE (arg0) == ADDR_EXPR
8392 && TREE_CODE (TREE_OPERAND (arg0, 0)) == COMPONENT_REF
8393 && TREE_CODE (arg1) == ADDR_EXPR
8394 && TREE_CODE (TREE_OPERAND (arg1, 0)) == COMPONENT_REF)
8396 tree cref0 = TREE_OPERAND (arg0, 0);
8397 tree cref1 = TREE_OPERAND (arg1, 0);
8398 if (TREE_OPERAND (cref0, 1) == TREE_OPERAND (cref1, 1))
8400 tree op0 = TREE_OPERAND (cref0, 0);
8401 tree op1 = TREE_OPERAND (cref1, 0);
8402 return fold_build2 (code, type,
8403 build_fold_addr_expr (op0),
8404 build_fold_addr_expr (op1));
8408 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
8409 into a single range test. */
8410 if ((TREE_CODE (arg0) == TRUNC_DIV_EXPR
8411 || TREE_CODE (arg0) == EXACT_DIV_EXPR)
8412 && TREE_CODE (arg1) == INTEGER_CST
8413 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8414 && !integer_zerop (TREE_OPERAND (arg0, 1))
8415 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
8416 && !TREE_OVERFLOW (arg1))
8418 tem = fold_div_compare (code, type, arg0, arg1);
8419 if (tem != NULL_TREE)
8427 /* Subroutine of fold_binary. Optimize complex multiplications of the
8428 form z * conj(z), as pow(realpart(z),2) + pow(imagpart(z),2). The
8429 argument EXPR represents the expression "z" of type TYPE. */
8432 fold_mult_zconjz (tree type, tree expr)
8434 tree itype = TREE_TYPE (type);
8435 tree rpart, ipart, tem;
8437 if (TREE_CODE (expr) == COMPLEX_EXPR)
8439 rpart = TREE_OPERAND (expr, 0);
8440 ipart = TREE_OPERAND (expr, 1);
8442 else if (TREE_CODE (expr) == COMPLEX_CST)
8444 rpart = TREE_REALPART (expr);
8445 ipart = TREE_IMAGPART (expr);
8449 expr = save_expr (expr);
8450 rpart = fold_build1 (REALPART_EXPR, itype, expr);
8451 ipart = fold_build1 (IMAGPART_EXPR, itype, expr);
8454 rpart = save_expr (rpart);
8455 ipart = save_expr (ipart);
8456 tem = fold_build2 (PLUS_EXPR, itype,
8457 fold_build2 (MULT_EXPR, itype, rpart, rpart),
8458 fold_build2 (MULT_EXPR, itype, ipart, ipart));
8459 return fold_build2 (COMPLEX_EXPR, type, tem,
8460 fold_convert (itype, integer_zero_node));
8464 /* Fold a binary expression of code CODE and type TYPE with operands
8465 OP0 and OP1. Return the folded expression if folding is
8466 successful. Otherwise, return NULL_TREE. */
8469 fold_binary (enum tree_code code, tree type, tree op0, tree op1)
8471 enum tree_code_class kind = TREE_CODE_CLASS (code);
8472 tree arg0, arg1, tem;
8473 tree t1 = NULL_TREE;
8474 bool strict_overflow_p;
8476 gcc_assert (IS_EXPR_CODE_CLASS (kind)
8477 && TREE_CODE_LENGTH (code) == 2
8479 && op1 != NULL_TREE);
8484 /* Strip any conversions that don't change the mode. This is
8485 safe for every expression, except for a comparison expression
8486 because its signedness is derived from its operands. So, in
8487 the latter case, only strip conversions that don't change the
8490 Note that this is done as an internal manipulation within the
8491 constant folder, in order to find the simplest representation
8492 of the arguments so that their form can be studied. In any
8493 cases, the appropriate type conversions should be put back in
8494 the tree that will get out of the constant folder. */
8496 if (kind == tcc_comparison)
8498 STRIP_SIGN_NOPS (arg0);
8499 STRIP_SIGN_NOPS (arg1);
8507 /* Note that TREE_CONSTANT isn't enough: static var addresses are
8508 constant but we can't do arithmetic on them. */
8509 if ((TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
8510 || (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
8511 || (TREE_CODE (arg0) == COMPLEX_CST && TREE_CODE (arg1) == COMPLEX_CST)
8512 || (TREE_CODE (arg0) == VECTOR_CST && TREE_CODE (arg1) == VECTOR_CST))
8514 if (kind == tcc_binary)
8515 tem = const_binop (code, arg0, arg1, 0);
8516 else if (kind == tcc_comparison)
8517 tem = fold_relational_const (code, type, arg0, arg1);
8521 if (tem != NULL_TREE)
8523 if (TREE_TYPE (tem) != type)
8524 tem = fold_convert (type, tem);
8529 /* If this is a commutative operation, and ARG0 is a constant, move it
8530 to ARG1 to reduce the number of tests below. */
8531 if (commutative_tree_code (code)
8532 && tree_swap_operands_p (arg0, arg1, true))
8533 return fold_build2 (code, type, op1, op0);
8535 /* ARG0 is the first operand of EXPR, and ARG1 is the second operand.
8537 First check for cases where an arithmetic operation is applied to a
8538 compound, conditional, or comparison operation. Push the arithmetic
8539 operation inside the compound or conditional to see if any folding
8540 can then be done. Convert comparison to conditional for this purpose.
8541 The also optimizes non-constant cases that used to be done in
8544 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
8545 one of the operands is a comparison and the other is a comparison, a
8546 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
8547 code below would make the expression more complex. Change it to a
8548 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
8549 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
8551 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
8552 || code == EQ_EXPR || code == NE_EXPR)
8553 && ((truth_value_p (TREE_CODE (arg0))
8554 && (truth_value_p (TREE_CODE (arg1))
8555 || (TREE_CODE (arg1) == BIT_AND_EXPR
8556 && integer_onep (TREE_OPERAND (arg1, 1)))))
8557 || (truth_value_p (TREE_CODE (arg1))
8558 && (truth_value_p (TREE_CODE (arg0))
8559 || (TREE_CODE (arg0) == BIT_AND_EXPR
8560 && integer_onep (TREE_OPERAND (arg0, 1)))))))
8562 tem = fold_build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
8563 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
8566 fold_convert (boolean_type_node, arg0),
8567 fold_convert (boolean_type_node, arg1));
8569 if (code == EQ_EXPR)
8570 tem = invert_truthvalue (tem);
8572 return fold_convert (type, tem);
8575 if (TREE_CODE_CLASS (code) == tcc_binary
8576 || TREE_CODE_CLASS (code) == tcc_comparison)
8578 if (TREE_CODE (arg0) == COMPOUND_EXPR)
8579 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
8580 fold_build2 (code, type,
8581 TREE_OPERAND (arg0, 1), op1));
8582 if (TREE_CODE (arg1) == COMPOUND_EXPR
8583 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
8584 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
8585 fold_build2 (code, type,
8586 op0, TREE_OPERAND (arg1, 1)));
8588 if (TREE_CODE (arg0) == COND_EXPR || COMPARISON_CLASS_P (arg0))
8590 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
8592 /*cond_first_p=*/1);
8593 if (tem != NULL_TREE)
8597 if (TREE_CODE (arg1) == COND_EXPR || COMPARISON_CLASS_P (arg1))
8599 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
8601 /*cond_first_p=*/0);
8602 if (tem != NULL_TREE)
8610 /* A + (-B) -> A - B */
8611 if (TREE_CODE (arg1) == NEGATE_EXPR)
8612 return fold_build2 (MINUS_EXPR, type,
8613 fold_convert (type, arg0),
8614 fold_convert (type, TREE_OPERAND (arg1, 0)));
8615 /* (-A) + B -> B - A */
8616 if (TREE_CODE (arg0) == NEGATE_EXPR
8617 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
8618 return fold_build2 (MINUS_EXPR, type,
8619 fold_convert (type, arg1),
8620 fold_convert (type, TREE_OPERAND (arg0, 0)));
8621 /* Convert ~A + 1 to -A. */
8622 if (INTEGRAL_TYPE_P (type)
8623 && TREE_CODE (arg0) == BIT_NOT_EXPR
8624 && integer_onep (arg1))
8625 return fold_build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0));
8627 /* Handle (A1 * C1) + (A2 * C2) with A1, A2 or C1, C2 being the
8629 if ((TREE_CODE (arg0) == MULT_EXPR
8630 || TREE_CODE (arg1) == MULT_EXPR)
8631 && (!FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
8633 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
8638 if (! FLOAT_TYPE_P (type))
8640 if (integer_zerop (arg1))
8641 return non_lvalue (fold_convert (type, arg0));
8643 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
8644 with a constant, and the two constants have no bits in common,
8645 we should treat this as a BIT_IOR_EXPR since this may produce more
8647 if (TREE_CODE (arg0) == BIT_AND_EXPR
8648 && TREE_CODE (arg1) == BIT_AND_EXPR
8649 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8650 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
8651 && integer_zerop (const_binop (BIT_AND_EXPR,
8652 TREE_OPERAND (arg0, 1),
8653 TREE_OPERAND (arg1, 1), 0)))
8655 code = BIT_IOR_EXPR;
8659 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
8660 (plus (plus (mult) (mult)) (foo)) so that we can
8661 take advantage of the factoring cases below. */
8662 if (((TREE_CODE (arg0) == PLUS_EXPR
8663 || TREE_CODE (arg0) == MINUS_EXPR)
8664 && TREE_CODE (arg1) == MULT_EXPR)
8665 || ((TREE_CODE (arg1) == PLUS_EXPR
8666 || TREE_CODE (arg1) == MINUS_EXPR)
8667 && TREE_CODE (arg0) == MULT_EXPR))
8669 tree parg0, parg1, parg, marg;
8670 enum tree_code pcode;
8672 if (TREE_CODE (arg1) == MULT_EXPR)
8673 parg = arg0, marg = arg1;
8675 parg = arg1, marg = arg0;
8676 pcode = TREE_CODE (parg);
8677 parg0 = TREE_OPERAND (parg, 0);
8678 parg1 = TREE_OPERAND (parg, 1);
8682 if (TREE_CODE (parg0) == MULT_EXPR
8683 && TREE_CODE (parg1) != MULT_EXPR)
8684 return fold_build2 (pcode, type,
8685 fold_build2 (PLUS_EXPR, type,
8686 fold_convert (type, parg0),
8687 fold_convert (type, marg)),
8688 fold_convert (type, parg1));
8689 if (TREE_CODE (parg0) != MULT_EXPR
8690 && TREE_CODE (parg1) == MULT_EXPR)
8691 return fold_build2 (PLUS_EXPR, type,
8692 fold_convert (type, parg0),
8693 fold_build2 (pcode, type,
8694 fold_convert (type, marg),
8699 /* Try replacing &a[i1] + c * i2 with &a[i1 + i2], if c is step
8700 of the array. Loop optimizer sometimes produce this type of
8702 if (TREE_CODE (arg0) == ADDR_EXPR)
8704 tem = try_move_mult_to_index (PLUS_EXPR, arg0, arg1);
8706 return fold_convert (type, tem);
8708 else if (TREE_CODE (arg1) == ADDR_EXPR)
8710 tem = try_move_mult_to_index (PLUS_EXPR, arg1, arg0);
8712 return fold_convert (type, tem);
8717 /* See if ARG1 is zero and X + ARG1 reduces to X. */
8718 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
8719 return non_lvalue (fold_convert (type, arg0));
8721 /* Likewise if the operands are reversed. */
8722 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
8723 return non_lvalue (fold_convert (type, arg1));
8725 /* Convert X + -C into X - C. */
8726 if (TREE_CODE (arg1) == REAL_CST
8727 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
8729 tem = fold_negate_const (arg1, type);
8730 if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
8731 return fold_build2 (MINUS_EXPR, type,
8732 fold_convert (type, arg0),
8733 fold_convert (type, tem));
8736 if (flag_unsafe_math_optimizations
8737 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
8738 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
8739 && (tem = distribute_real_division (code, type, arg0, arg1)))
8742 /* Convert x+x into x*2.0. */
8743 if (operand_equal_p (arg0, arg1, 0)
8744 && SCALAR_FLOAT_TYPE_P (type))
8745 return fold_build2 (MULT_EXPR, type, arg0,
8746 build_real (type, dconst2));
8748 /* Convert a + (b*c + d*e) into (a + b*c) + d*e. */
8749 if (flag_unsafe_math_optimizations
8750 && TREE_CODE (arg1) == PLUS_EXPR
8751 && TREE_CODE (arg0) != MULT_EXPR)
8753 tree tree10 = TREE_OPERAND (arg1, 0);
8754 tree tree11 = TREE_OPERAND (arg1, 1);
8755 if (TREE_CODE (tree11) == MULT_EXPR
8756 && TREE_CODE (tree10) == MULT_EXPR)
8759 tree0 = fold_build2 (PLUS_EXPR, type, arg0, tree10);
8760 return fold_build2 (PLUS_EXPR, type, tree0, tree11);
8763 /* Convert (b*c + d*e) + a into b*c + (d*e +a). */
8764 if (flag_unsafe_math_optimizations
8765 && TREE_CODE (arg0) == PLUS_EXPR
8766 && TREE_CODE (arg1) != MULT_EXPR)
8768 tree tree00 = TREE_OPERAND (arg0, 0);
8769 tree tree01 = TREE_OPERAND (arg0, 1);
8770 if (TREE_CODE (tree01) == MULT_EXPR
8771 && TREE_CODE (tree00) == MULT_EXPR)
8774 tree0 = fold_build2 (PLUS_EXPR, type, tree01, arg1);
8775 return fold_build2 (PLUS_EXPR, type, tree00, tree0);
8781 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
8782 is a rotate of A by C1 bits. */
8783 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
8784 is a rotate of A by B bits. */
8786 enum tree_code code0, code1;
8787 code0 = TREE_CODE (arg0);
8788 code1 = TREE_CODE (arg1);
8789 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
8790 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
8791 && operand_equal_p (TREE_OPERAND (arg0, 0),
8792 TREE_OPERAND (arg1, 0), 0)
8793 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
8795 tree tree01, tree11;
8796 enum tree_code code01, code11;
8798 tree01 = TREE_OPERAND (arg0, 1);
8799 tree11 = TREE_OPERAND (arg1, 1);
8800 STRIP_NOPS (tree01);
8801 STRIP_NOPS (tree11);
8802 code01 = TREE_CODE (tree01);
8803 code11 = TREE_CODE (tree11);
8804 if (code01 == INTEGER_CST
8805 && code11 == INTEGER_CST
8806 && TREE_INT_CST_HIGH (tree01) == 0
8807 && TREE_INT_CST_HIGH (tree11) == 0
8808 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
8809 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
8810 return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
8811 code0 == LSHIFT_EXPR ? tree01 : tree11);
8812 else if (code11 == MINUS_EXPR)
8814 tree tree110, tree111;
8815 tree110 = TREE_OPERAND (tree11, 0);
8816 tree111 = TREE_OPERAND (tree11, 1);
8817 STRIP_NOPS (tree110);
8818 STRIP_NOPS (tree111);
8819 if (TREE_CODE (tree110) == INTEGER_CST
8820 && 0 == compare_tree_int (tree110,
8822 (TREE_TYPE (TREE_OPERAND
8824 && operand_equal_p (tree01, tree111, 0))
8825 return build2 ((code0 == LSHIFT_EXPR
8828 type, TREE_OPERAND (arg0, 0), tree01);
8830 else if (code01 == MINUS_EXPR)
8832 tree tree010, tree011;
8833 tree010 = TREE_OPERAND (tree01, 0);
8834 tree011 = TREE_OPERAND (tree01, 1);
8835 STRIP_NOPS (tree010);
8836 STRIP_NOPS (tree011);
8837 if (TREE_CODE (tree010) == INTEGER_CST
8838 && 0 == compare_tree_int (tree010,
8840 (TREE_TYPE (TREE_OPERAND
8842 && operand_equal_p (tree11, tree011, 0))
8843 return build2 ((code0 != LSHIFT_EXPR
8846 type, TREE_OPERAND (arg0, 0), tree11);
8852 /* In most languages, can't associate operations on floats through
8853 parentheses. Rather than remember where the parentheses were, we
8854 don't associate floats at all, unless the user has specified
8855 -funsafe-math-optimizations. */
8857 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
8859 tree var0, con0, lit0, minus_lit0;
8860 tree var1, con1, lit1, minus_lit1;
8863 /* Split both trees into variables, constants, and literals. Then
8864 associate each group together, the constants with literals,
8865 then the result with variables. This increases the chances of
8866 literals being recombined later and of generating relocatable
8867 expressions for the sum of a constant and literal. */
8868 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
8869 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
8870 code == MINUS_EXPR);
8872 /* With undefined overflow we can only associate constants
8873 with one variable. */
8874 if ((POINTER_TYPE_P (type)
8875 || (INTEGRAL_TYPE_P (type)
8876 && !(TYPE_UNSIGNED (type) || flag_wrapv)))
8882 if (TREE_CODE (tmp0) == NEGATE_EXPR)
8883 tmp0 = TREE_OPERAND (tmp0, 0);
8884 if (TREE_CODE (tmp1) == NEGATE_EXPR)
8885 tmp1 = TREE_OPERAND (tmp1, 0);
8886 /* The only case we can still associate with two variables
8887 is if they are the same, modulo negation. */
8888 if (!operand_equal_p (tmp0, tmp1, 0))
8892 /* Only do something if we found more than two objects. Otherwise,
8893 nothing has changed and we risk infinite recursion. */
8895 && (2 < ((var0 != 0) + (var1 != 0)
8896 + (con0 != 0) + (con1 != 0)
8897 + (lit0 != 0) + (lit1 != 0)
8898 + (minus_lit0 != 0) + (minus_lit1 != 0))))
8900 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
8901 if (code == MINUS_EXPR)
8904 var0 = associate_trees (var0, var1, code, type);
8905 con0 = associate_trees (con0, con1, code, type);
8906 lit0 = associate_trees (lit0, lit1, code, type);
8907 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
8909 /* Preserve the MINUS_EXPR if the negative part of the literal is
8910 greater than the positive part. Otherwise, the multiplicative
8911 folding code (i.e extract_muldiv) may be fooled in case
8912 unsigned constants are subtracted, like in the following
8913 example: ((X*2 + 4) - 8U)/2. */
8914 if (minus_lit0 && lit0)
8916 if (TREE_CODE (lit0) == INTEGER_CST
8917 && TREE_CODE (minus_lit0) == INTEGER_CST
8918 && tree_int_cst_lt (lit0, minus_lit0))
8920 minus_lit0 = associate_trees (minus_lit0, lit0,
8926 lit0 = associate_trees (lit0, minus_lit0,
8934 return fold_convert (type,
8935 associate_trees (var0, minus_lit0,
8939 con0 = associate_trees (con0, minus_lit0,
8941 return fold_convert (type,
8942 associate_trees (var0, con0,
8947 con0 = associate_trees (con0, lit0, code, type);
8948 return fold_convert (type, associate_trees (var0, con0,
8956 /* A - (-B) -> A + B */
8957 if (TREE_CODE (arg1) == NEGATE_EXPR)
8958 return fold_build2 (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0));
8959 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
8960 if (TREE_CODE (arg0) == NEGATE_EXPR
8961 && (FLOAT_TYPE_P (type)
8962 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
8963 && negate_expr_p (arg1)
8964 && reorder_operands_p (arg0, arg1))
8965 return fold_build2 (MINUS_EXPR, type, negate_expr (arg1),
8966 TREE_OPERAND (arg0, 0));
8967 /* Convert -A - 1 to ~A. */
8968 if (INTEGRAL_TYPE_P (type)
8969 && TREE_CODE (arg0) == NEGATE_EXPR
8970 && integer_onep (arg1))
8971 return fold_build1 (BIT_NOT_EXPR, type,
8972 fold_convert (type, TREE_OPERAND (arg0, 0)));
8974 /* Convert -1 - A to ~A. */
8975 if (INTEGRAL_TYPE_P (type)
8976 && integer_all_onesp (arg0))
8977 return fold_build1 (BIT_NOT_EXPR, type, arg1);
8979 if (! FLOAT_TYPE_P (type))
8981 if (integer_zerop (arg0))
8982 return negate_expr (fold_convert (type, arg1));
8983 if (integer_zerop (arg1))
8984 return non_lvalue (fold_convert (type, arg0));
8986 /* Fold A - (A & B) into ~B & A. */
8987 if (!TREE_SIDE_EFFECTS (arg0)
8988 && TREE_CODE (arg1) == BIT_AND_EXPR)
8990 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
8991 return fold_build2 (BIT_AND_EXPR, type,
8992 fold_build1 (BIT_NOT_EXPR, type,
8993 TREE_OPERAND (arg1, 0)),
8995 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8996 return fold_build2 (BIT_AND_EXPR, type,
8997 fold_build1 (BIT_NOT_EXPR, type,
8998 TREE_OPERAND (arg1, 1)),
9002 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
9003 any power of 2 minus 1. */
9004 if (TREE_CODE (arg0) == BIT_AND_EXPR
9005 && TREE_CODE (arg1) == BIT_AND_EXPR
9006 && operand_equal_p (TREE_OPERAND (arg0, 0),
9007 TREE_OPERAND (arg1, 0), 0))
9009 tree mask0 = TREE_OPERAND (arg0, 1);
9010 tree mask1 = TREE_OPERAND (arg1, 1);
9011 tree tem = fold_build1 (BIT_NOT_EXPR, type, mask0);
9013 if (operand_equal_p (tem, mask1, 0))
9015 tem = fold_build2 (BIT_XOR_EXPR, type,
9016 TREE_OPERAND (arg0, 0), mask1);
9017 return fold_build2 (MINUS_EXPR, type, tem, mask1);
9022 /* See if ARG1 is zero and X - ARG1 reduces to X. */
9023 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
9024 return non_lvalue (fold_convert (type, arg0));
9026 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
9027 ARG0 is zero and X + ARG0 reduces to X, since that would mean
9028 (-ARG1 + ARG0) reduces to -ARG1. */
9029 else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
9030 return negate_expr (fold_convert (type, arg1));
9032 /* Fold &x - &x. This can happen from &x.foo - &x.
9033 This is unsafe for certain floats even in non-IEEE formats.
9034 In IEEE, it is unsafe because it does wrong for NaNs.
9035 Also note that operand_equal_p is always false if an operand
9038 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
9039 && operand_equal_p (arg0, arg1, 0))
9040 return fold_convert (type, integer_zero_node);
9042 /* A - B -> A + (-B) if B is easily negatable. */
9043 if (negate_expr_p (arg1)
9044 && ((FLOAT_TYPE_P (type)
9045 /* Avoid this transformation if B is a positive REAL_CST. */
9046 && (TREE_CODE (arg1) != REAL_CST
9047 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
9048 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv)))
9049 return fold_build2 (PLUS_EXPR, type,
9050 fold_convert (type, arg0),
9051 fold_convert (type, negate_expr (arg1)));
9053 /* Try folding difference of addresses. */
9057 if ((TREE_CODE (arg0) == ADDR_EXPR
9058 || TREE_CODE (arg1) == ADDR_EXPR)
9059 && ptr_difference_const (arg0, arg1, &diff))
9060 return build_int_cst_type (type, diff);
9063 /* Fold &a[i] - &a[j] to i-j. */
9064 if (TREE_CODE (arg0) == ADDR_EXPR
9065 && TREE_CODE (TREE_OPERAND (arg0, 0)) == ARRAY_REF
9066 && TREE_CODE (arg1) == ADDR_EXPR
9067 && TREE_CODE (TREE_OPERAND (arg1, 0)) == ARRAY_REF)
9069 tree aref0 = TREE_OPERAND (arg0, 0);
9070 tree aref1 = TREE_OPERAND (arg1, 0);
9071 if (operand_equal_p (TREE_OPERAND (aref0, 0),
9072 TREE_OPERAND (aref1, 0), 0))
9074 tree op0 = fold_convert (type, TREE_OPERAND (aref0, 1));
9075 tree op1 = fold_convert (type, TREE_OPERAND (aref1, 1));
9076 tree esz = array_ref_element_size (aref0);
9077 tree diff = build2 (MINUS_EXPR, type, op0, op1);
9078 return fold_build2 (MULT_EXPR, type, diff,
9079 fold_convert (type, esz));
9084 /* Try replacing &a[i1] - c * i2 with &a[i1 - i2], if c is step
9085 of the array. Loop optimizer sometimes produce this type of
9087 if (TREE_CODE (arg0) == ADDR_EXPR)
9089 tem = try_move_mult_to_index (MINUS_EXPR, arg0, arg1);
9091 return fold_convert (type, tem);
9094 if (flag_unsafe_math_optimizations
9095 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
9096 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
9097 && (tem = distribute_real_division (code, type, arg0, arg1)))
9100 /* Handle (A1 * C1) - (A2 * C2) with A1, A2 or C1, C2 being the
9102 if ((TREE_CODE (arg0) == MULT_EXPR
9103 || TREE_CODE (arg1) == MULT_EXPR)
9104 && (!FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
9106 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
9114 /* (-A) * (-B) -> A * B */
9115 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
9116 return fold_build2 (MULT_EXPR, type,
9117 fold_convert (type, TREE_OPERAND (arg0, 0)),
9118 fold_convert (type, negate_expr (arg1)));
9119 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
9120 return fold_build2 (MULT_EXPR, type,
9121 fold_convert (type, negate_expr (arg0)),
9122 fold_convert (type, TREE_OPERAND (arg1, 0)));
9124 if (! FLOAT_TYPE_P (type))
9126 if (integer_zerop (arg1))
9127 return omit_one_operand (type, arg1, arg0);
9128 if (integer_onep (arg1))
9129 return non_lvalue (fold_convert (type, arg0));
9130 /* Transform x * -1 into -x. */
9131 if (integer_all_onesp (arg1))
9132 return fold_convert (type, negate_expr (arg0));
9134 /* (a * (1 << b)) is (a << b) */
9135 if (TREE_CODE (arg1) == LSHIFT_EXPR
9136 && integer_onep (TREE_OPERAND (arg1, 0)))
9137 return fold_build2 (LSHIFT_EXPR, type, arg0,
9138 TREE_OPERAND (arg1, 1));
9139 if (TREE_CODE (arg0) == LSHIFT_EXPR
9140 && integer_onep (TREE_OPERAND (arg0, 0)))
9141 return fold_build2 (LSHIFT_EXPR, type, arg1,
9142 TREE_OPERAND (arg0, 1));
9144 strict_overflow_p = false;
9145 if (TREE_CODE (arg1) == INTEGER_CST
9146 && 0 != (tem = extract_muldiv (op0,
9147 fold_convert (type, arg1),
9149 &strict_overflow_p)))
9151 if (strict_overflow_p)
9152 fold_overflow_warning (("assuming signed overflow does not "
9153 "occur when simplifying "
9155 WARN_STRICT_OVERFLOW_MISC);
9156 return fold_convert (type, tem);
9159 /* Optimize z * conj(z) for integer complex numbers. */
9160 if (TREE_CODE (arg0) == CONJ_EXPR
9161 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
9162 return fold_mult_zconjz (type, arg1);
9163 if (TREE_CODE (arg1) == CONJ_EXPR
9164 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
9165 return fold_mult_zconjz (type, arg0);
9169 /* Maybe fold x * 0 to 0. The expressions aren't the same
9170 when x is NaN, since x * 0 is also NaN. Nor are they the
9171 same in modes with signed zeros, since multiplying a
9172 negative value by 0 gives -0, not +0. */
9173 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
9174 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
9175 && real_zerop (arg1))
9176 return omit_one_operand (type, arg1, arg0);
9177 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
9178 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
9179 && real_onep (arg1))
9180 return non_lvalue (fold_convert (type, arg0));
9182 /* Transform x * -1.0 into -x. */
9183 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
9184 && real_minus_onep (arg1))
9185 return fold_convert (type, negate_expr (arg0));
9187 /* Convert (C1/X)*C2 into (C1*C2)/X. */
9188 if (flag_unsafe_math_optimizations
9189 && TREE_CODE (arg0) == RDIV_EXPR
9190 && TREE_CODE (arg1) == REAL_CST
9191 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
9193 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
9196 return fold_build2 (RDIV_EXPR, type, tem,
9197 TREE_OPERAND (arg0, 1));
9200 /* Strip sign operations from X in X*X, i.e. -Y*-Y -> Y*Y. */
9201 if (operand_equal_p (arg0, arg1, 0))
9203 tree tem = fold_strip_sign_ops (arg0);
9204 if (tem != NULL_TREE)
9206 tem = fold_convert (type, tem);
9207 return fold_build2 (MULT_EXPR, type, tem, tem);
9211 /* Optimize z * conj(z) for floating point complex numbers.
9212 Guarded by flag_unsafe_math_optimizations as non-finite
9213 imaginary components don't produce scalar results. */
9214 if (flag_unsafe_math_optimizations
9215 && TREE_CODE (arg0) == CONJ_EXPR
9216 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
9217 return fold_mult_zconjz (type, arg1);
9218 if (flag_unsafe_math_optimizations
9219 && TREE_CODE (arg1) == CONJ_EXPR
9220 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
9221 return fold_mult_zconjz (type, arg0);
9223 if (flag_unsafe_math_optimizations)
9225 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
9226 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
9228 /* Optimizations of root(...)*root(...). */
9229 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
9231 tree rootfn, arg, arglist;
9232 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
9233 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
9235 /* Optimize sqrt(x)*sqrt(x) as x. */
9236 if (BUILTIN_SQRT_P (fcode0)
9237 && operand_equal_p (arg00, arg10, 0)
9238 && ! HONOR_SNANS (TYPE_MODE (type)))
9241 /* Optimize root(x)*root(y) as root(x*y). */
9242 rootfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
9243 arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
9244 arglist = build_tree_list (NULL_TREE, arg);
9245 return build_function_call_expr (rootfn, arglist);
9248 /* Optimize expN(x)*expN(y) as expN(x+y). */
9249 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
9251 tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
9252 tree arg = fold_build2 (PLUS_EXPR, type,
9253 TREE_VALUE (TREE_OPERAND (arg0, 1)),
9254 TREE_VALUE (TREE_OPERAND (arg1, 1)));
9255 tree arglist = build_tree_list (NULL_TREE, arg);
9256 return build_function_call_expr (expfn, arglist);
9259 /* Optimizations of pow(...)*pow(...). */
9260 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
9261 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
9262 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
9264 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
9265 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
9267 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
9268 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
9271 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
9272 if (operand_equal_p (arg01, arg11, 0))
9274 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
9275 tree arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
9276 tree arglist = tree_cons (NULL_TREE, arg,
9277 build_tree_list (NULL_TREE,
9279 return build_function_call_expr (powfn, arglist);
9282 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
9283 if (operand_equal_p (arg00, arg10, 0))
9285 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
9286 tree arg = fold_build2 (PLUS_EXPR, type, arg01, arg11);
9287 tree arglist = tree_cons (NULL_TREE, arg00,
9288 build_tree_list (NULL_TREE,
9290 return build_function_call_expr (powfn, arglist);
9294 /* Optimize tan(x)*cos(x) as sin(x). */
9295 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
9296 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
9297 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
9298 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
9299 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
9300 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
9301 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
9302 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
9304 tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
9306 if (sinfn != NULL_TREE)
9307 return build_function_call_expr (sinfn,
9308 TREE_OPERAND (arg0, 1));
9311 /* Optimize x*pow(x,c) as pow(x,c+1). */
9312 if (fcode1 == BUILT_IN_POW
9313 || fcode1 == BUILT_IN_POWF
9314 || fcode1 == BUILT_IN_POWL)
9316 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
9317 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
9319 if (TREE_CODE (arg11) == REAL_CST
9320 && ! TREE_CONSTANT_OVERFLOW (arg11)
9321 && operand_equal_p (arg0, arg10, 0))
9323 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
9327 c = TREE_REAL_CST (arg11);
9328 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
9329 arg = build_real (type, c);
9330 arglist = build_tree_list (NULL_TREE, arg);
9331 arglist = tree_cons (NULL_TREE, arg0, arglist);
9332 return build_function_call_expr (powfn, arglist);
9336 /* Optimize pow(x,c)*x as pow(x,c+1). */
9337 if (fcode0 == BUILT_IN_POW
9338 || fcode0 == BUILT_IN_POWF
9339 || fcode0 == BUILT_IN_POWL)
9341 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
9342 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
9344 if (TREE_CODE (arg01) == REAL_CST
9345 && ! TREE_CONSTANT_OVERFLOW (arg01)
9346 && operand_equal_p (arg1, arg00, 0))
9348 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
9352 c = TREE_REAL_CST (arg01);
9353 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
9354 arg = build_real (type, c);
9355 arglist = build_tree_list (NULL_TREE, arg);
9356 arglist = tree_cons (NULL_TREE, arg1, arglist);
9357 return build_function_call_expr (powfn, arglist);
9361 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
9363 && operand_equal_p (arg0, arg1, 0))
9365 tree powfn = mathfn_built_in (type, BUILT_IN_POW);
9369 tree arg = build_real (type, dconst2);
9370 tree arglist = build_tree_list (NULL_TREE, arg);
9371 arglist = tree_cons (NULL_TREE, arg0, arglist);
9372 return build_function_call_expr (powfn, arglist);
9381 if (integer_all_onesp (arg1))
9382 return omit_one_operand (type, arg1, arg0);
9383 if (integer_zerop (arg1))
9384 return non_lvalue (fold_convert (type, arg0));
9385 if (operand_equal_p (arg0, arg1, 0))
9386 return non_lvalue (fold_convert (type, arg0));
9389 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9390 && INTEGRAL_TYPE_P (TREE_TYPE (arg1))
9391 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
9393 t1 = build_int_cst (type, -1);
9394 t1 = force_fit_type (t1, 0, false, false);
9395 return omit_one_operand (type, t1, arg1);
9399 if (TREE_CODE (arg1) == BIT_NOT_EXPR
9400 && INTEGRAL_TYPE_P (TREE_TYPE (arg0))
9401 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
9403 t1 = build_int_cst (type, -1);
9404 t1 = force_fit_type (t1, 0, false, false);
9405 return omit_one_operand (type, t1, arg0);
9408 /* Canonicalize (X & C1) | C2. */
9409 if (TREE_CODE (arg0) == BIT_AND_EXPR
9410 && TREE_CODE (arg1) == INTEGER_CST
9411 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
9413 unsigned HOST_WIDE_INT hi1, lo1, hi2, lo2, mlo, mhi;
9414 int width = TYPE_PRECISION (type);
9415 hi1 = TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1));
9416 lo1 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
9417 hi2 = TREE_INT_CST_HIGH (arg1);
9418 lo2 = TREE_INT_CST_LOW (arg1);
9420 /* If (C1&C2) == C1, then (X&C1)|C2 becomes (X,C2). */
9421 if ((hi1 & hi2) == hi1 && (lo1 & lo2) == lo1)
9422 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
9424 if (width > HOST_BITS_PER_WIDE_INT)
9426 mhi = (unsigned HOST_WIDE_INT) -1
9427 >> (2 * HOST_BITS_PER_WIDE_INT - width);
9433 mlo = (unsigned HOST_WIDE_INT) -1
9434 >> (HOST_BITS_PER_WIDE_INT - width);
9437 /* If (C1|C2) == ~0 then (X&C1)|C2 becomes X|C2. */
9438 if ((~(hi1 | hi2) & mhi) == 0 && (~(lo1 | lo2) & mlo) == 0)
9439 return fold_build2 (BIT_IOR_EXPR, type,
9440 TREE_OPERAND (arg0, 0), arg1);
9442 /* Minimize the number of bits set in C1, i.e. C1 := C1 & ~C2. */
9445 if ((hi1 & ~hi2) != hi1 || (lo1 & ~lo2) != lo1)
9446 return fold_build2 (BIT_IOR_EXPR, type,
9447 fold_build2 (BIT_AND_EXPR, type,
9448 TREE_OPERAND (arg0, 0),
9449 build_int_cst_wide (type,
9455 /* (X & Y) | Y is (X, Y). */
9456 if (TREE_CODE (arg0) == BIT_AND_EXPR
9457 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
9458 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
9459 /* (X & Y) | X is (Y, X). */
9460 if (TREE_CODE (arg0) == BIT_AND_EXPR
9461 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
9462 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
9463 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
9464 /* X | (X & Y) is (Y, X). */
9465 if (TREE_CODE (arg1) == BIT_AND_EXPR
9466 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
9467 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
9468 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
9469 /* X | (Y & X) is (Y, X). */
9470 if (TREE_CODE (arg1) == BIT_AND_EXPR
9471 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
9472 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
9473 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
9475 t1 = distribute_bit_expr (code, type, arg0, arg1);
9476 if (t1 != NULL_TREE)
9479 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
9481 This results in more efficient code for machines without a NAND
9482 instruction. Combine will canonicalize to the first form
9483 which will allow use of NAND instructions provided by the
9484 backend if they exist. */
9485 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9486 && TREE_CODE (arg1) == BIT_NOT_EXPR)
9488 return fold_build1 (BIT_NOT_EXPR, type,
9489 build2 (BIT_AND_EXPR, type,
9490 TREE_OPERAND (arg0, 0),
9491 TREE_OPERAND (arg1, 0)));
9494 /* See if this can be simplified into a rotate first. If that
9495 is unsuccessful continue in the association code. */
9499 if (integer_zerop (arg1))
9500 return non_lvalue (fold_convert (type, arg0));
9501 if (integer_all_onesp (arg1))
9502 return fold_build1 (BIT_NOT_EXPR, type, arg0);
9503 if (operand_equal_p (arg0, arg1, 0))
9504 return omit_one_operand (type, integer_zero_node, arg0);
9507 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9508 && INTEGRAL_TYPE_P (TREE_TYPE (arg1))
9509 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
9511 t1 = build_int_cst (type, -1);
9512 t1 = force_fit_type (t1, 0, false, false);
9513 return omit_one_operand (type, t1, arg1);
9517 if (TREE_CODE (arg1) == BIT_NOT_EXPR
9518 && INTEGRAL_TYPE_P (TREE_TYPE (arg0))
9519 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
9521 t1 = build_int_cst (type, -1);
9522 t1 = force_fit_type (t1, 0, false, false);
9523 return omit_one_operand (type, t1, arg0);
9526 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
9527 with a constant, and the two constants have no bits in common,
9528 we should treat this as a BIT_IOR_EXPR since this may produce more
9530 if (TREE_CODE (arg0) == BIT_AND_EXPR
9531 && TREE_CODE (arg1) == BIT_AND_EXPR
9532 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9533 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
9534 && integer_zerop (const_binop (BIT_AND_EXPR,
9535 TREE_OPERAND (arg0, 1),
9536 TREE_OPERAND (arg1, 1), 0)))
9538 code = BIT_IOR_EXPR;
9542 /* (X | Y) ^ X -> Y & ~ X*/
9543 if (TREE_CODE (arg0) == BIT_IOR_EXPR
9544 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
9546 tree t2 = TREE_OPERAND (arg0, 1);
9547 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
9549 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
9550 fold_convert (type, t1));
9554 /* (Y | X) ^ X -> Y & ~ X*/
9555 if (TREE_CODE (arg0) == BIT_IOR_EXPR
9556 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
9558 tree t2 = TREE_OPERAND (arg0, 0);
9559 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
9561 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
9562 fold_convert (type, t1));
9566 /* X ^ (X | Y) -> Y & ~ X*/
9567 if (TREE_CODE (arg1) == BIT_IOR_EXPR
9568 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
9570 tree t2 = TREE_OPERAND (arg1, 1);
9571 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
9573 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
9574 fold_convert (type, t1));
9578 /* X ^ (Y | X) -> Y & ~ X*/
9579 if (TREE_CODE (arg1) == BIT_IOR_EXPR
9580 && operand_equal_p (TREE_OPERAND (arg1, 1), arg0, 0))
9582 tree t2 = TREE_OPERAND (arg1, 0);
9583 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
9585 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
9586 fold_convert (type, t1));
9590 /* Convert ~X ^ ~Y to X ^ Y. */
9591 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9592 && TREE_CODE (arg1) == BIT_NOT_EXPR)
9593 return fold_build2 (code, type,
9594 fold_convert (type, TREE_OPERAND (arg0, 0)),
9595 fold_convert (type, TREE_OPERAND (arg1, 0)));
9597 /* Fold (X & 1) ^ 1 as (X & 1) == 0. */
9598 if (TREE_CODE (arg0) == BIT_AND_EXPR
9599 && integer_onep (TREE_OPERAND (arg0, 1))
9600 && integer_onep (arg1))
9601 return fold_build2 (EQ_EXPR, type, arg0,
9602 build_int_cst (TREE_TYPE (arg0), 0));
9604 /* Fold (X & Y) ^ Y as ~X & Y. */
9605 if (TREE_CODE (arg0) == BIT_AND_EXPR
9606 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
9608 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
9609 return fold_build2 (BIT_AND_EXPR, type,
9610 fold_build1 (BIT_NOT_EXPR, type, tem),
9611 fold_convert (type, arg1));
9613 /* Fold (X & Y) ^ X as ~Y & X. */
9614 if (TREE_CODE (arg0) == BIT_AND_EXPR
9615 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
9616 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
9618 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
9619 return fold_build2 (BIT_AND_EXPR, type,
9620 fold_build1 (BIT_NOT_EXPR, type, tem),
9621 fold_convert (type, arg1));
9623 /* Fold X ^ (X & Y) as X & ~Y. */
9624 if (TREE_CODE (arg1) == BIT_AND_EXPR
9625 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
9627 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
9628 return fold_build2 (BIT_AND_EXPR, type,
9629 fold_convert (type, arg0),
9630 fold_build1 (BIT_NOT_EXPR, type, tem));
9632 /* Fold X ^ (Y & X) as ~Y & X. */
9633 if (TREE_CODE (arg1) == BIT_AND_EXPR
9634 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
9635 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
9637 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
9638 return fold_build2 (BIT_AND_EXPR, type,
9639 fold_build1 (BIT_NOT_EXPR, type, tem),
9640 fold_convert (type, arg0));
9643 /* See if this can be simplified into a rotate first. If that
9644 is unsuccessful continue in the association code. */
9648 if (integer_all_onesp (arg1))
9649 return non_lvalue (fold_convert (type, arg0));
9650 if (integer_zerop (arg1))
9651 return omit_one_operand (type, arg1, arg0);
9652 if (operand_equal_p (arg0, arg1, 0))
9653 return non_lvalue (fold_convert (type, arg0));
9655 /* ~X & X is always zero. */
9656 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9657 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
9658 return omit_one_operand (type, integer_zero_node, arg1);
9660 /* X & ~X is always zero. */
9661 if (TREE_CODE (arg1) == BIT_NOT_EXPR
9662 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
9663 return omit_one_operand (type, integer_zero_node, arg0);
9665 /* Canonicalize (X | C1) & C2 as (X & C2) | (C1 & C2). */
9666 if (TREE_CODE (arg0) == BIT_IOR_EXPR
9667 && TREE_CODE (arg1) == INTEGER_CST
9668 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
9669 return fold_build2 (BIT_IOR_EXPR, type,
9670 fold_build2 (BIT_AND_EXPR, type,
9671 TREE_OPERAND (arg0, 0), arg1),
9672 fold_build2 (BIT_AND_EXPR, type,
9673 TREE_OPERAND (arg0, 1), arg1));
9675 /* (X | Y) & Y is (X, Y). */
9676 if (TREE_CODE (arg0) == BIT_IOR_EXPR
9677 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
9678 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
9679 /* (X | Y) & X is (Y, X). */
9680 if (TREE_CODE (arg0) == BIT_IOR_EXPR
9681 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
9682 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
9683 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
9684 /* X & (X | Y) is (Y, X). */
9685 if (TREE_CODE (arg1) == BIT_IOR_EXPR
9686 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
9687 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
9688 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
9689 /* X & (Y | X) is (Y, X). */
9690 if (TREE_CODE (arg1) == BIT_IOR_EXPR
9691 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
9692 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
9693 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
9695 /* Fold (X ^ 1) & 1 as (X & 1) == 0. */
9696 if (TREE_CODE (arg0) == BIT_XOR_EXPR
9697 && integer_onep (TREE_OPERAND (arg0, 1))
9698 && integer_onep (arg1))
9700 tem = TREE_OPERAND (arg0, 0);
9701 return fold_build2 (EQ_EXPR, type,
9702 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
9703 build_int_cst (TREE_TYPE (tem), 1)),
9704 build_int_cst (TREE_TYPE (tem), 0));
9706 /* Fold ~X & 1 as (X & 1) == 0. */
9707 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9708 && integer_onep (arg1))
9710 tem = TREE_OPERAND (arg0, 0);
9711 return fold_build2 (EQ_EXPR, type,
9712 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
9713 build_int_cst (TREE_TYPE (tem), 1)),
9714 build_int_cst (TREE_TYPE (tem), 0));
9717 /* Fold (X ^ Y) & Y as ~X & Y. */
9718 if (TREE_CODE (arg0) == BIT_XOR_EXPR
9719 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
9721 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
9722 return fold_build2 (BIT_AND_EXPR, type,
9723 fold_build1 (BIT_NOT_EXPR, type, tem),
9724 fold_convert (type, arg1));
9726 /* Fold (X ^ Y) & X as ~Y & X. */
9727 if (TREE_CODE (arg0) == BIT_XOR_EXPR
9728 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
9729 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
9731 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
9732 return fold_build2 (BIT_AND_EXPR, type,
9733 fold_build1 (BIT_NOT_EXPR, type, tem),
9734 fold_convert (type, arg1));
9736 /* Fold X & (X ^ Y) as X & ~Y. */
9737 if (TREE_CODE (arg1) == BIT_XOR_EXPR
9738 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
9740 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
9741 return fold_build2 (BIT_AND_EXPR, type,
9742 fold_convert (type, arg0),
9743 fold_build1 (BIT_NOT_EXPR, type, tem));
9745 /* Fold X & (Y ^ X) as ~Y & X. */
9746 if (TREE_CODE (arg1) == BIT_XOR_EXPR
9747 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
9748 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
9750 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
9751 return fold_build2 (BIT_AND_EXPR, type,
9752 fold_build1 (BIT_NOT_EXPR, type, tem),
9753 fold_convert (type, arg0));
9756 t1 = distribute_bit_expr (code, type, arg0, arg1);
9757 if (t1 != NULL_TREE)
9759 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
9760 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
9761 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
9764 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
9766 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
9767 && (~TREE_INT_CST_LOW (arg1)
9768 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
9769 return fold_convert (type, TREE_OPERAND (arg0, 0));
9772 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
9774 This results in more efficient code for machines without a NOR
9775 instruction. Combine will canonicalize to the first form
9776 which will allow use of NOR instructions provided by the
9777 backend if they exist. */
9778 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9779 && TREE_CODE (arg1) == BIT_NOT_EXPR)
9781 return fold_build1 (BIT_NOT_EXPR, type,
9782 build2 (BIT_IOR_EXPR, type,
9783 TREE_OPERAND (arg0, 0),
9784 TREE_OPERAND (arg1, 0)));
9790 /* Don't touch a floating-point divide by zero unless the mode
9791 of the constant can represent infinity. */
9792 if (TREE_CODE (arg1) == REAL_CST
9793 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
9794 && real_zerop (arg1))
9797 /* Optimize A / A to 1.0 if we don't care about
9798 NaNs or Infinities. Skip the transformation
9799 for non-real operands. */
9800 if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (arg0))
9801 && ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
9802 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg0)))
9803 && operand_equal_p (arg0, arg1, 0))
9805 tree r = build_real (TREE_TYPE (arg0), dconst1);
9807 return omit_two_operands (type, r, arg0, arg1);
9810 /* The complex version of the above A / A optimization. */
9811 if (COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
9812 && operand_equal_p (arg0, arg1, 0))
9814 tree elem_type = TREE_TYPE (TREE_TYPE (arg0));
9815 if (! HONOR_NANS (TYPE_MODE (elem_type))
9816 && ! HONOR_INFINITIES (TYPE_MODE (elem_type)))
9818 tree r = build_real (elem_type, dconst1);
9819 /* omit_two_operands will call fold_convert for us. */
9820 return omit_two_operands (type, r, arg0, arg1);
9824 /* (-A) / (-B) -> A / B */
9825 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
9826 return fold_build2 (RDIV_EXPR, type,
9827 TREE_OPERAND (arg0, 0),
9828 negate_expr (arg1));
9829 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
9830 return fold_build2 (RDIV_EXPR, type,
9832 TREE_OPERAND (arg1, 0));
9834 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
9835 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
9836 && real_onep (arg1))
9837 return non_lvalue (fold_convert (type, arg0));
9839 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
9840 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
9841 && real_minus_onep (arg1))
9842 return non_lvalue (fold_convert (type, negate_expr (arg0)));
9844 /* If ARG1 is a constant, we can convert this to a multiply by the
9845 reciprocal. This does not have the same rounding properties,
9846 so only do this if -funsafe-math-optimizations. We can actually
9847 always safely do it if ARG1 is a power of two, but it's hard to
9848 tell if it is or not in a portable manner. */
9849 if (TREE_CODE (arg1) == REAL_CST)
9851 if (flag_unsafe_math_optimizations
9852 && 0 != (tem = const_binop (code, build_real (type, dconst1),
9854 return fold_build2 (MULT_EXPR, type, arg0, tem);
9855 /* Find the reciprocal if optimizing and the result is exact. */
9859 r = TREE_REAL_CST (arg1);
9860 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
9862 tem = build_real (type, r);
9863 return fold_build2 (MULT_EXPR, type,
9864 fold_convert (type, arg0), tem);
9868 /* Convert A/B/C to A/(B*C). */
9869 if (flag_unsafe_math_optimizations
9870 && TREE_CODE (arg0) == RDIV_EXPR)
9871 return fold_build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
9872 fold_build2 (MULT_EXPR, type,
9873 TREE_OPERAND (arg0, 1), arg1));
9875 /* Convert A/(B/C) to (A/B)*C. */
9876 if (flag_unsafe_math_optimizations
9877 && TREE_CODE (arg1) == RDIV_EXPR)
9878 return fold_build2 (MULT_EXPR, type,
9879 fold_build2 (RDIV_EXPR, type, arg0,
9880 TREE_OPERAND (arg1, 0)),
9881 TREE_OPERAND (arg1, 1));
9883 /* Convert C1/(X*C2) into (C1/C2)/X. */
9884 if (flag_unsafe_math_optimizations
9885 && TREE_CODE (arg1) == MULT_EXPR
9886 && TREE_CODE (arg0) == REAL_CST
9887 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
9889 tree tem = const_binop (RDIV_EXPR, arg0,
9890 TREE_OPERAND (arg1, 1), 0);
9892 return fold_build2 (RDIV_EXPR, type, tem,
9893 TREE_OPERAND (arg1, 0));
9896 if (flag_unsafe_math_optimizations)
9898 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
9899 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
9901 /* Optimize sin(x)/cos(x) as tan(x). */
9902 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
9903 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
9904 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
9905 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
9906 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
9908 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
9910 if (tanfn != NULL_TREE)
9911 return build_function_call_expr (tanfn,
9912 TREE_OPERAND (arg0, 1));
9915 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
9916 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
9917 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
9918 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
9919 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
9920 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
9922 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
9924 if (tanfn != NULL_TREE)
9926 tree tmp = TREE_OPERAND (arg0, 1);
9927 tmp = build_function_call_expr (tanfn, tmp);
9928 return fold_build2 (RDIV_EXPR, type,
9929 build_real (type, dconst1), tmp);
9933 /* Optimize sin(x)/tan(x) as cos(x) if we don't care about
9934 NaNs or Infinities. */
9935 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_TAN)
9936 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_TANF)
9937 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_TANL)))
9939 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
9940 tree arg01 = TREE_VALUE (TREE_OPERAND (arg1, 1));
9942 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
9943 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
9944 && operand_equal_p (arg00, arg01, 0))
9946 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
9948 if (cosfn != NULL_TREE)
9949 return build_function_call_expr (cosfn,
9950 TREE_OPERAND (arg0, 1));
9954 /* Optimize tan(x)/sin(x) as 1.0/cos(x) if we don't care about
9955 NaNs or Infinities. */
9956 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_SIN)
9957 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_SINF)
9958 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_SINL)))
9960 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
9961 tree arg01 = TREE_VALUE (TREE_OPERAND (arg1, 1));
9963 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
9964 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
9965 && operand_equal_p (arg00, arg01, 0))
9967 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
9969 if (cosfn != NULL_TREE)
9971 tree tmp = TREE_OPERAND (arg0, 1);
9972 tmp = build_function_call_expr (cosfn, tmp);
9973 return fold_build2 (RDIV_EXPR, type,
9974 build_real (type, dconst1),
9980 /* Optimize pow(x,c)/x as pow(x,c-1). */
9981 if (fcode0 == BUILT_IN_POW
9982 || fcode0 == BUILT_IN_POWF
9983 || fcode0 == BUILT_IN_POWL)
9985 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
9986 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0, 1)));
9987 if (TREE_CODE (arg01) == REAL_CST
9988 && ! TREE_CONSTANT_OVERFLOW (arg01)
9989 && operand_equal_p (arg1, arg00, 0))
9991 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
9995 c = TREE_REAL_CST (arg01);
9996 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
9997 arg = build_real (type, c);
9998 arglist = build_tree_list (NULL_TREE, arg);
9999 arglist = tree_cons (NULL_TREE, arg1, arglist);
10000 return build_function_call_expr (powfn, arglist);
10004 /* Optimize x/expN(y) into x*expN(-y). */
10005 if (BUILTIN_EXPONENT_P (fcode1))
10007 tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
10008 tree arg = negate_expr (TREE_VALUE (TREE_OPERAND (arg1, 1)));
10009 tree arglist = build_tree_list (NULL_TREE,
10010 fold_convert (type, arg));
10011 arg1 = build_function_call_expr (expfn, arglist);
10012 return fold_build2 (MULT_EXPR, type, arg0, arg1);
10015 /* Optimize x/pow(y,z) into x*pow(y,-z). */
10016 if (fcode1 == BUILT_IN_POW
10017 || fcode1 == BUILT_IN_POWF
10018 || fcode1 == BUILT_IN_POWL)
10020 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
10021 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
10022 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
10023 tree neg11 = fold_convert (type, negate_expr (arg11));
10024 tree arglist = tree_cons(NULL_TREE, arg10,
10025 build_tree_list (NULL_TREE, neg11));
10026 arg1 = build_function_call_expr (powfn, arglist);
10027 return fold_build2 (MULT_EXPR, type, arg0, arg1);
10032 case TRUNC_DIV_EXPR:
10033 case FLOOR_DIV_EXPR:
10034 /* Simplify A / (B << N) where A and B are positive and B is
10035 a power of 2, to A >> (N + log2(B)). */
10036 strict_overflow_p = false;
10037 if (TREE_CODE (arg1) == LSHIFT_EXPR
10038 && (TYPE_UNSIGNED (type)
10039 || tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p)))
10041 tree sval = TREE_OPERAND (arg1, 0);
10042 if (integer_pow2p (sval) && tree_int_cst_sgn (sval) > 0)
10044 tree sh_cnt = TREE_OPERAND (arg1, 1);
10045 unsigned long pow2 = exact_log2 (TREE_INT_CST_LOW (sval));
10047 if (strict_overflow_p)
10048 fold_overflow_warning (("assuming signed overflow does not "
10049 "occur when simplifying A / (B << N)"),
10050 WARN_STRICT_OVERFLOW_MISC);
10052 sh_cnt = fold_build2 (PLUS_EXPR, TREE_TYPE (sh_cnt),
10053 sh_cnt, build_int_cst (NULL_TREE, pow2));
10054 return fold_build2 (RSHIFT_EXPR, type,
10055 fold_convert (type, arg0), sh_cnt);
10060 case ROUND_DIV_EXPR:
10061 case CEIL_DIV_EXPR:
10062 case EXACT_DIV_EXPR:
10063 if (integer_onep (arg1))
10064 return non_lvalue (fold_convert (type, arg0));
10065 if (integer_zerop (arg1))
10067 /* X / -1 is -X. */
10068 if (!TYPE_UNSIGNED (type)
10069 && TREE_CODE (arg1) == INTEGER_CST
10070 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
10071 && TREE_INT_CST_HIGH (arg1) == -1)
10072 return fold_convert (type, negate_expr (arg0));
10074 /* Convert -A / -B to A / B when the type is signed and overflow is
10076 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
10077 && TREE_CODE (arg0) == NEGATE_EXPR
10078 && negate_expr_p (arg1))
10080 if (INTEGRAL_TYPE_P (type))
10081 fold_overflow_warning (("assuming signed overflow does not occur "
10082 "when distributing negation across "
10084 WARN_STRICT_OVERFLOW_MISC);
10085 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
10086 negate_expr (arg1));
10088 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
10089 && TREE_CODE (arg1) == NEGATE_EXPR
10090 && negate_expr_p (arg0))
10092 if (INTEGRAL_TYPE_P (type))
10093 fold_overflow_warning (("assuming signed overflow does not occur "
10094 "when distributing negation across "
10096 WARN_STRICT_OVERFLOW_MISC);
10097 return fold_build2 (code, type, negate_expr (arg0),
10098 TREE_OPERAND (arg1, 0));
10101 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
10102 operation, EXACT_DIV_EXPR.
10104 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
10105 At one time others generated faster code, it's not clear if they do
10106 after the last round to changes to the DIV code in expmed.c. */
10107 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
10108 && multiple_of_p (type, arg0, arg1))
10109 return fold_build2 (EXACT_DIV_EXPR, type, arg0, arg1);
10111 strict_overflow_p = false;
10112 if (TREE_CODE (arg1) == INTEGER_CST
10113 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
10114 &strict_overflow_p)))
10116 if (strict_overflow_p)
10117 fold_overflow_warning (("assuming signed overflow does not occur "
10118 "when simplifying division"),
10119 WARN_STRICT_OVERFLOW_MISC);
10120 return fold_convert (type, tem);
10125 case CEIL_MOD_EXPR:
10126 case FLOOR_MOD_EXPR:
10127 case ROUND_MOD_EXPR:
10128 case TRUNC_MOD_EXPR:
10129 /* X % 1 is always zero, but be sure to preserve any side
10131 if (integer_onep (arg1))
10132 return omit_one_operand (type, integer_zero_node, arg0);
10134 /* X % 0, return X % 0 unchanged so that we can get the
10135 proper warnings and errors. */
10136 if (integer_zerop (arg1))
10139 /* 0 % X is always zero, but be sure to preserve any side
10140 effects in X. Place this after checking for X == 0. */
10141 if (integer_zerop (arg0))
10142 return omit_one_operand (type, integer_zero_node, arg1);
10144 /* X % -1 is zero. */
10145 if (!TYPE_UNSIGNED (type)
10146 && TREE_CODE (arg1) == INTEGER_CST
10147 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
10148 && TREE_INT_CST_HIGH (arg1) == -1)
10149 return omit_one_operand (type, integer_zero_node, arg0);
10151 /* Optimize TRUNC_MOD_EXPR by a power of two into a BIT_AND_EXPR,
10152 i.e. "X % C" into "X & (C - 1)", if X and C are positive. */
10153 strict_overflow_p = false;
10154 if ((code == TRUNC_MOD_EXPR || code == FLOOR_MOD_EXPR)
10155 && (TYPE_UNSIGNED (type)
10156 || tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p)))
10159 /* Also optimize A % (C << N) where C is a power of 2,
10160 to A & ((C << N) - 1). */
10161 if (TREE_CODE (arg1) == LSHIFT_EXPR)
10162 c = TREE_OPERAND (arg1, 0);
10164 if (integer_pow2p (c) && tree_int_cst_sgn (c) > 0)
10166 tree mask = fold_build2 (MINUS_EXPR, TREE_TYPE (arg1),
10167 arg1, integer_one_node);
10168 if (strict_overflow_p)
10169 fold_overflow_warning (("assuming signed overflow does not "
10170 "occur when simplifying "
10171 "X % (power of two)"),
10172 WARN_STRICT_OVERFLOW_MISC);
10173 return fold_build2 (BIT_AND_EXPR, type,
10174 fold_convert (type, arg0),
10175 fold_convert (type, mask));
10179 /* X % -C is the same as X % C. */
10180 if (code == TRUNC_MOD_EXPR
10181 && !TYPE_UNSIGNED (type)
10182 && TREE_CODE (arg1) == INTEGER_CST
10183 && !TREE_CONSTANT_OVERFLOW (arg1)
10184 && TREE_INT_CST_HIGH (arg1) < 0
10185 && !TYPE_OVERFLOW_TRAPS (type)
10186 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
10187 && !sign_bit_p (arg1, arg1))
10188 return fold_build2 (code, type, fold_convert (type, arg0),
10189 fold_convert (type, negate_expr (arg1)));
10191 /* X % -Y is the same as X % Y. */
10192 if (code == TRUNC_MOD_EXPR
10193 && !TYPE_UNSIGNED (type)
10194 && TREE_CODE (arg1) == NEGATE_EXPR
10195 && !TYPE_OVERFLOW_TRAPS (type))
10196 return fold_build2 (code, type, fold_convert (type, arg0),
10197 fold_convert (type, TREE_OPERAND (arg1, 0)));
10199 if (TREE_CODE (arg1) == INTEGER_CST
10200 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
10201 &strict_overflow_p)))
10203 if (strict_overflow_p)
10204 fold_overflow_warning (("assuming signed overflow does not occur "
10205 "when simplifying modulos"),
10206 WARN_STRICT_OVERFLOW_MISC);
10207 return fold_convert (type, tem);
10214 if (integer_all_onesp (arg0))
10215 return omit_one_operand (type, arg0, arg1);
10219 /* Optimize -1 >> x for arithmetic right shifts. */
10220 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type))
10221 return omit_one_operand (type, arg0, arg1);
10222 /* ... fall through ... */
10226 if (integer_zerop (arg1))
10227 return non_lvalue (fold_convert (type, arg0));
10228 if (integer_zerop (arg0))
10229 return omit_one_operand (type, arg0, arg1);
10231 /* Since negative shift count is not well-defined,
10232 don't try to compute it in the compiler. */
10233 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
10236 /* Turn (a OP c1) OP c2 into a OP (c1+c2). */
10237 if (TREE_CODE (op0) == code && host_integerp (arg1, false)
10238 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
10239 && host_integerp (TREE_OPERAND (arg0, 1), false)
10240 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
10242 HOST_WIDE_INT low = (TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1))
10243 + TREE_INT_CST_LOW (arg1));
10245 /* Deal with a OP (c1 + c2) being undefined but (a OP c1) OP c2
10246 being well defined. */
10247 if (low >= TYPE_PRECISION (type))
10249 if (code == LROTATE_EXPR || code == RROTATE_EXPR)
10250 low = low % TYPE_PRECISION (type);
10251 else if (TYPE_UNSIGNED (type) || code == LSHIFT_EXPR)
10252 return build_int_cst (type, 0);
10254 low = TYPE_PRECISION (type) - 1;
10257 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
10258 build_int_cst (type, low));
10261 /* Transform (x >> c) << c into x & (-1<<c), or transform (x << c) >> c
10262 into x & ((unsigned)-1 >> c) for unsigned types. */
10263 if (((code == LSHIFT_EXPR && TREE_CODE (arg0) == RSHIFT_EXPR)
10264 || (TYPE_UNSIGNED (type)
10265 && code == RSHIFT_EXPR && TREE_CODE (arg0) == LSHIFT_EXPR))
10266 && host_integerp (arg1, false)
10267 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
10268 && host_integerp (TREE_OPERAND (arg0, 1), false)
10269 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
10271 HOST_WIDE_INT low0 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
10272 HOST_WIDE_INT low1 = TREE_INT_CST_LOW (arg1);
10278 arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
10280 lshift = build_int_cst (type, -1);
10281 lshift = int_const_binop (code, lshift, arg1, 0);
10283 return fold_build2 (BIT_AND_EXPR, type, arg00, lshift);
10287 /* Rewrite an LROTATE_EXPR by a constant into an
10288 RROTATE_EXPR by a new constant. */
10289 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
10291 tree tem = build_int_cst (NULL_TREE,
10292 GET_MODE_BITSIZE (TYPE_MODE (type)));
10293 tem = fold_convert (TREE_TYPE (arg1), tem);
10294 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
10295 return fold_build2 (RROTATE_EXPR, type, arg0, tem);
10298 /* If we have a rotate of a bit operation with the rotate count and
10299 the second operand of the bit operation both constant,
10300 permute the two operations. */
10301 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
10302 && (TREE_CODE (arg0) == BIT_AND_EXPR
10303 || TREE_CODE (arg0) == BIT_IOR_EXPR
10304 || TREE_CODE (arg0) == BIT_XOR_EXPR)
10305 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10306 return fold_build2 (TREE_CODE (arg0), type,
10307 fold_build2 (code, type,
10308 TREE_OPERAND (arg0, 0), arg1),
10309 fold_build2 (code, type,
10310 TREE_OPERAND (arg0, 1), arg1));
10312 /* Two consecutive rotates adding up to the width of the mode can
10314 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
10315 && TREE_CODE (arg0) == RROTATE_EXPR
10316 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
10317 && TREE_INT_CST_HIGH (arg1) == 0
10318 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
10319 && ((TREE_INT_CST_LOW (arg1)
10320 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
10321 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
10322 return TREE_OPERAND (arg0, 0);
10327 if (operand_equal_p (arg0, arg1, 0))
10328 return omit_one_operand (type, arg0, arg1);
10329 if (INTEGRAL_TYPE_P (type)
10330 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
10331 return omit_one_operand (type, arg1, arg0);
10332 tem = fold_minmax (MIN_EXPR, type, arg0, arg1);
10338 if (operand_equal_p (arg0, arg1, 0))
10339 return omit_one_operand (type, arg0, arg1);
10340 if (INTEGRAL_TYPE_P (type)
10341 && TYPE_MAX_VALUE (type)
10342 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
10343 return omit_one_operand (type, arg1, arg0);
10344 tem = fold_minmax (MAX_EXPR, type, arg0, arg1);
10349 case TRUTH_ANDIF_EXPR:
10350 /* Note that the operands of this must be ints
10351 and their values must be 0 or 1.
10352 ("true" is a fixed value perhaps depending on the language.) */
10353 /* If first arg is constant zero, return it. */
10354 if (integer_zerop (arg0))
10355 return fold_convert (type, arg0);
10356 case TRUTH_AND_EXPR:
10357 /* If either arg is constant true, drop it. */
10358 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
10359 return non_lvalue (fold_convert (type, arg1));
10360 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
10361 /* Preserve sequence points. */
10362 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
10363 return non_lvalue (fold_convert (type, arg0));
10364 /* If second arg is constant zero, result is zero, but first arg
10365 must be evaluated. */
10366 if (integer_zerop (arg1))
10367 return omit_one_operand (type, arg1, arg0);
10368 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
10369 case will be handled here. */
10370 if (integer_zerop (arg0))
10371 return omit_one_operand (type, arg0, arg1);
10373 /* !X && X is always false. */
10374 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
10375 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10376 return omit_one_operand (type, integer_zero_node, arg1);
10377 /* X && !X is always false. */
10378 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
10379 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10380 return omit_one_operand (type, integer_zero_node, arg0);
10382 /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
10383 means A >= Y && A != MAX, but in this case we know that
10386 if (!TREE_SIDE_EFFECTS (arg0)
10387 && !TREE_SIDE_EFFECTS (arg1))
10389 tem = fold_to_nonsharp_ineq_using_bound (arg0, arg1);
10390 if (tem && !operand_equal_p (tem, arg0, 0))
10391 return fold_build2 (code, type, tem, arg1);
10393 tem = fold_to_nonsharp_ineq_using_bound (arg1, arg0);
10394 if (tem && !operand_equal_p (tem, arg1, 0))
10395 return fold_build2 (code, type, arg0, tem);
10399 /* We only do these simplifications if we are optimizing. */
10403 /* Check for things like (A || B) && (A || C). We can convert this
10404 to A || (B && C). Note that either operator can be any of the four
10405 truth and/or operations and the transformation will still be
10406 valid. Also note that we only care about order for the
10407 ANDIF and ORIF operators. If B contains side effects, this
10408 might change the truth-value of A. */
10409 if (TREE_CODE (arg0) == TREE_CODE (arg1)
10410 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
10411 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
10412 || TREE_CODE (arg0) == TRUTH_AND_EXPR
10413 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
10414 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
10416 tree a00 = TREE_OPERAND (arg0, 0);
10417 tree a01 = TREE_OPERAND (arg0, 1);
10418 tree a10 = TREE_OPERAND (arg1, 0);
10419 tree a11 = TREE_OPERAND (arg1, 1);
10420 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
10421 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
10422 && (code == TRUTH_AND_EXPR
10423 || code == TRUTH_OR_EXPR));
10425 if (operand_equal_p (a00, a10, 0))
10426 return fold_build2 (TREE_CODE (arg0), type, a00,
10427 fold_build2 (code, type, a01, a11));
10428 else if (commutative && operand_equal_p (a00, a11, 0))
10429 return fold_build2 (TREE_CODE (arg0), type, a00,
10430 fold_build2 (code, type, a01, a10));
10431 else if (commutative && operand_equal_p (a01, a10, 0))
10432 return fold_build2 (TREE_CODE (arg0), type, a01,
10433 fold_build2 (code, type, a00, a11));
10435 /* This case if tricky because we must either have commutative
10436 operators or else A10 must not have side-effects. */
10438 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
10439 && operand_equal_p (a01, a11, 0))
10440 return fold_build2 (TREE_CODE (arg0), type,
10441 fold_build2 (code, type, a00, a10),
10445 /* See if we can build a range comparison. */
10446 if (0 != (tem = fold_range_test (code, type, op0, op1)))
10449 /* Check for the possibility of merging component references. If our
10450 lhs is another similar operation, try to merge its rhs with our
10451 rhs. Then try to merge our lhs and rhs. */
10452 if (TREE_CODE (arg0) == code
10453 && 0 != (tem = fold_truthop (code, type,
10454 TREE_OPERAND (arg0, 1), arg1)))
10455 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
10457 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
10462 case TRUTH_ORIF_EXPR:
10463 /* Note that the operands of this must be ints
10464 and their values must be 0 or true.
10465 ("true" is a fixed value perhaps depending on the language.) */
10466 /* If first arg is constant true, return it. */
10467 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
10468 return fold_convert (type, arg0);
10469 case TRUTH_OR_EXPR:
10470 /* If either arg is constant zero, drop it. */
10471 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
10472 return non_lvalue (fold_convert (type, arg1));
10473 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
10474 /* Preserve sequence points. */
10475 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
10476 return non_lvalue (fold_convert (type, arg0));
10477 /* If second arg is constant true, result is true, but we must
10478 evaluate first arg. */
10479 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
10480 return omit_one_operand (type, arg1, arg0);
10481 /* Likewise for first arg, but note this only occurs here for
10483 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
10484 return omit_one_operand (type, arg0, arg1);
10486 /* !X || X is always true. */
10487 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
10488 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10489 return omit_one_operand (type, integer_one_node, arg1);
10490 /* X || !X is always true. */
10491 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
10492 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10493 return omit_one_operand (type, integer_one_node, arg0);
10497 case TRUTH_XOR_EXPR:
10498 /* If the second arg is constant zero, drop it. */
10499 if (integer_zerop (arg1))
10500 return non_lvalue (fold_convert (type, arg0));
10501 /* If the second arg is constant true, this is a logical inversion. */
10502 if (integer_onep (arg1))
10504 /* Only call invert_truthvalue if operand is a truth value. */
10505 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
10506 tem = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg0), arg0);
10508 tem = invert_truthvalue (arg0);
10509 return non_lvalue (fold_convert (type, tem));
10511 /* Identical arguments cancel to zero. */
10512 if (operand_equal_p (arg0, arg1, 0))
10513 return omit_one_operand (type, integer_zero_node, arg0);
10515 /* !X ^ X is always true. */
10516 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
10517 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10518 return omit_one_operand (type, integer_one_node, arg1);
10520 /* X ^ !X is always true. */
10521 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
10522 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10523 return omit_one_operand (type, integer_one_node, arg0);
10529 tem = fold_comparison (code, type, op0, op1);
10530 if (tem != NULL_TREE)
10533 /* bool_var != 0 becomes bool_var. */
10534 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
10535 && code == NE_EXPR)
10536 return non_lvalue (fold_convert (type, arg0));
10538 /* bool_var == 1 becomes bool_var. */
10539 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
10540 && code == EQ_EXPR)
10541 return non_lvalue (fold_convert (type, arg0));
10543 /* bool_var != 1 becomes !bool_var. */
10544 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
10545 && code == NE_EXPR)
10546 return fold_build1 (TRUTH_NOT_EXPR, type, arg0);
10548 /* bool_var == 0 becomes !bool_var. */
10549 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
10550 && code == EQ_EXPR)
10551 return fold_build1 (TRUTH_NOT_EXPR, type, arg0);
10553 /* ~a != C becomes a != ~C where C is a constant. Likewise for ==. */
10554 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10555 && TREE_CODE (arg1) == INTEGER_CST)
10557 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
10558 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
10559 fold_build1 (BIT_NOT_EXPR, cmp_type,
10560 fold_convert (cmp_type, arg1)));
10563 /* If this is an equality comparison of the address of a non-weak
10564 object against zero, then we know the result. */
10565 if (TREE_CODE (arg0) == ADDR_EXPR
10566 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg0, 0))
10567 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
10568 && integer_zerop (arg1))
10569 return constant_boolean_node (code != EQ_EXPR, type);
10571 /* If this is an equality comparison of the address of two non-weak,
10572 unaliased symbols neither of which are extern (since we do not
10573 have access to attributes for externs), then we know the result. */
10574 if (TREE_CODE (arg0) == ADDR_EXPR
10575 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg0, 0))
10576 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
10577 && ! lookup_attribute ("alias",
10578 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
10579 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
10580 && TREE_CODE (arg1) == ADDR_EXPR
10581 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg1, 0))
10582 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
10583 && ! lookup_attribute ("alias",
10584 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
10585 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
10587 /* We know that we're looking at the address of two
10588 non-weak, unaliased, static _DECL nodes.
10590 It is both wasteful and incorrect to call operand_equal_p
10591 to compare the two ADDR_EXPR nodes. It is wasteful in that
10592 all we need to do is test pointer equality for the arguments
10593 to the two ADDR_EXPR nodes. It is incorrect to use
10594 operand_equal_p as that function is NOT equivalent to a
10595 C equality test. It can in fact return false for two
10596 objects which would test as equal using the C equality
10598 bool equal = TREE_OPERAND (arg0, 0) == TREE_OPERAND (arg1, 0);
10599 return constant_boolean_node (equal
10600 ? code == EQ_EXPR : code != EQ_EXPR,
10604 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
10605 a MINUS_EXPR of a constant, we can convert it into a comparison with
10606 a revised constant as long as no overflow occurs. */
10607 if (TREE_CODE (arg1) == INTEGER_CST
10608 && (TREE_CODE (arg0) == PLUS_EXPR
10609 || TREE_CODE (arg0) == MINUS_EXPR)
10610 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
10611 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
10612 ? MINUS_EXPR : PLUS_EXPR,
10613 fold_convert (TREE_TYPE (arg0), arg1),
10614 TREE_OPERAND (arg0, 1), 0))
10615 && ! TREE_CONSTANT_OVERFLOW (tem))
10616 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
10618 /* Similarly for a NEGATE_EXPR. */
10619 if (TREE_CODE (arg0) == NEGATE_EXPR
10620 && TREE_CODE (arg1) == INTEGER_CST
10621 && 0 != (tem = negate_expr (arg1))
10622 && TREE_CODE (tem) == INTEGER_CST
10623 && ! TREE_CONSTANT_OVERFLOW (tem))
10624 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
10626 /* If we have X - Y == 0, we can convert that to X == Y and similarly
10627 for !=. Don't do this for ordered comparisons due to overflow. */
10628 if (TREE_CODE (arg0) == MINUS_EXPR
10629 && integer_zerop (arg1))
10630 return fold_build2 (code, type,
10631 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
10633 /* Convert ABS_EXPR<x> == 0 or ABS_EXPR<x> != 0 to x == 0 or x != 0. */
10634 if (TREE_CODE (arg0) == ABS_EXPR
10635 && (integer_zerop (arg1) || real_zerop (arg1)))
10636 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), arg1);
10638 /* If this is an EQ or NE comparison with zero and ARG0 is
10639 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
10640 two operations, but the latter can be done in one less insn
10641 on machines that have only two-operand insns or on which a
10642 constant cannot be the first operand. */
10643 if (TREE_CODE (arg0) == BIT_AND_EXPR
10644 && integer_zerop (arg1))
10646 tree arg00 = TREE_OPERAND (arg0, 0);
10647 tree arg01 = TREE_OPERAND (arg0, 1);
10648 if (TREE_CODE (arg00) == LSHIFT_EXPR
10649 && integer_onep (TREE_OPERAND (arg00, 0)))
10651 fold_build2 (code, type,
10652 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
10653 build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
10654 arg01, TREE_OPERAND (arg00, 1)),
10655 fold_convert (TREE_TYPE (arg0),
10656 integer_one_node)),
10658 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
10659 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
10661 fold_build2 (code, type,
10662 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
10663 build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
10664 arg00, TREE_OPERAND (arg01, 1)),
10665 fold_convert (TREE_TYPE (arg0),
10666 integer_one_node)),
10670 /* If this is an NE or EQ comparison of zero against the result of a
10671 signed MOD operation whose second operand is a power of 2, make
10672 the MOD operation unsigned since it is simpler and equivalent. */
10673 if (integer_zerop (arg1)
10674 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
10675 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
10676 || TREE_CODE (arg0) == CEIL_MOD_EXPR
10677 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
10678 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
10679 && integer_pow2p (TREE_OPERAND (arg0, 1)))
10681 tree newtype = lang_hooks.types.unsigned_type (TREE_TYPE (arg0));
10682 tree newmod = fold_build2 (TREE_CODE (arg0), newtype,
10683 fold_convert (newtype,
10684 TREE_OPERAND (arg0, 0)),
10685 fold_convert (newtype,
10686 TREE_OPERAND (arg0, 1)));
10688 return fold_build2 (code, type, newmod,
10689 fold_convert (newtype, arg1));
10692 /* Fold ((X >> C1) & C2) == 0 and ((X >> C1) & C2) != 0 where
10693 C1 is a valid shift constant, and C2 is a power of two, i.e.
10695 if (TREE_CODE (arg0) == BIT_AND_EXPR
10696 && TREE_CODE (TREE_OPERAND (arg0, 0)) == RSHIFT_EXPR
10697 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1))
10699 && integer_pow2p (TREE_OPERAND (arg0, 1))
10700 && integer_zerop (arg1))
10702 tree itype = TREE_TYPE (arg0);
10703 unsigned HOST_WIDE_INT prec = TYPE_PRECISION (itype);
10704 tree arg001 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 1);
10706 /* Check for a valid shift count. */
10707 if (TREE_INT_CST_HIGH (arg001) == 0
10708 && TREE_INT_CST_LOW (arg001) < prec)
10710 tree arg01 = TREE_OPERAND (arg0, 1);
10711 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
10712 unsigned HOST_WIDE_INT log2 = tree_log2 (arg01);
10713 /* If (C2 << C1) doesn't overflow, then ((X >> C1) & C2) != 0
10714 can be rewritten as (X & (C2 << C1)) != 0. */
10715 if ((log2 + TREE_INT_CST_LOW (arg001)) < prec)
10717 tem = fold_build2 (LSHIFT_EXPR, itype, arg01, arg001);
10718 tem = fold_build2 (BIT_AND_EXPR, itype, arg000, tem);
10719 return fold_build2 (code, type, tem, arg1);
10721 /* Otherwise, for signed (arithmetic) shifts,
10722 ((X >> C1) & C2) != 0 is rewritten as X < 0, and
10723 ((X >> C1) & C2) == 0 is rewritten as X >= 0. */
10724 else if (!TYPE_UNSIGNED (itype))
10725 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR, type,
10726 arg000, build_int_cst (itype, 0));
10727 /* Otherwise, of unsigned (logical) shifts,
10728 ((X >> C1) & C2) != 0 is rewritten as (X,false), and
10729 ((X >> C1) & C2) == 0 is rewritten as (X,true). */
10731 return omit_one_operand (type,
10732 code == EQ_EXPR ? integer_one_node
10733 : integer_zero_node,
10738 /* If this is an NE comparison of zero with an AND of one, remove the
10739 comparison since the AND will give the correct value. */
10740 if (code == NE_EXPR
10741 && integer_zerop (arg1)
10742 && TREE_CODE (arg0) == BIT_AND_EXPR
10743 && integer_onep (TREE_OPERAND (arg0, 1)))
10744 return fold_convert (type, arg0);
10746 /* If we have (A & C) == C where C is a power of 2, convert this into
10747 (A & C) != 0. Similarly for NE_EXPR. */
10748 if (TREE_CODE (arg0) == BIT_AND_EXPR
10749 && integer_pow2p (TREE_OPERAND (arg0, 1))
10750 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10751 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
10752 arg0, fold_convert (TREE_TYPE (arg0),
10753 integer_zero_node));
10755 /* If we have (A & C) != 0 or (A & C) == 0 and C is the sign
10756 bit, then fold the expression into A < 0 or A >= 0. */
10757 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1, type);
10761 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
10762 Similarly for NE_EXPR. */
10763 if (TREE_CODE (arg0) == BIT_AND_EXPR
10764 && TREE_CODE (arg1) == INTEGER_CST
10765 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10767 tree notc = fold_build1 (BIT_NOT_EXPR,
10768 TREE_TYPE (TREE_OPERAND (arg0, 1)),
10769 TREE_OPERAND (arg0, 1));
10770 tree dandnotc = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
10772 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
10773 if (integer_nonzerop (dandnotc))
10774 return omit_one_operand (type, rslt, arg0);
10777 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
10778 Similarly for NE_EXPR. */
10779 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10780 && TREE_CODE (arg1) == INTEGER_CST
10781 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10783 tree notd = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1);
10784 tree candnotd = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
10785 TREE_OPERAND (arg0, 1), notd);
10786 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
10787 if (integer_nonzerop (candnotd))
10788 return omit_one_operand (type, rslt, arg0);
10791 /* If this is a comparison of a field, we may be able to simplify it. */
10792 if (((TREE_CODE (arg0) == COMPONENT_REF
10793 && lang_hooks.can_use_bit_fields_p ())
10794 || TREE_CODE (arg0) == BIT_FIELD_REF)
10795 /* Handle the constant case even without -O
10796 to make sure the warnings are given. */
10797 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
10799 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
10804 /* Optimize comparisons of strlen vs zero to a compare of the
10805 first character of the string vs zero. To wit,
10806 strlen(ptr) == 0 => *ptr == 0
10807 strlen(ptr) != 0 => *ptr != 0
10808 Other cases should reduce to one of these two (or a constant)
10809 due to the return value of strlen being unsigned. */
10810 if (TREE_CODE (arg0) == CALL_EXPR
10811 && integer_zerop (arg1))
10813 tree fndecl = get_callee_fndecl (arg0);
10817 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
10818 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
10819 && (arglist = TREE_OPERAND (arg0, 1))
10820 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
10821 && ! TREE_CHAIN (arglist))
10823 tree iref = build_fold_indirect_ref (TREE_VALUE (arglist));
10824 return fold_build2 (code, type, iref,
10825 build_int_cst (TREE_TYPE (iref), 0));
10829 /* Fold (X >> C) != 0 into X < 0 if C is one less than the width
10830 of X. Similarly fold (X >> C) == 0 into X >= 0. */
10831 if (TREE_CODE (arg0) == RSHIFT_EXPR
10832 && integer_zerop (arg1)
10833 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10835 tree arg00 = TREE_OPERAND (arg0, 0);
10836 tree arg01 = TREE_OPERAND (arg0, 1);
10837 tree itype = TREE_TYPE (arg00);
10838 if (TREE_INT_CST_HIGH (arg01) == 0
10839 && TREE_INT_CST_LOW (arg01)
10840 == (unsigned HOST_WIDE_INT) (TYPE_PRECISION (itype) - 1))
10842 if (TYPE_UNSIGNED (itype))
10844 itype = lang_hooks.types.signed_type (itype);
10845 arg00 = fold_convert (itype, arg00);
10847 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
10848 type, arg00, build_int_cst (itype, 0));
10852 /* (X ^ Y) == 0 becomes X == Y, and (X ^ Y) != 0 becomes X != Y. */
10853 if (integer_zerop (arg1)
10854 && TREE_CODE (arg0) == BIT_XOR_EXPR)
10855 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
10856 TREE_OPERAND (arg0, 1));
10858 /* (X ^ Y) == Y becomes X == 0. We know that Y has no side-effects. */
10859 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10860 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10861 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
10862 build_int_cst (TREE_TYPE (arg1), 0));
10863 /* Likewise (X ^ Y) == X becomes Y == 0. X has no side-effects. */
10864 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10865 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10866 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10867 return fold_build2 (code, type, TREE_OPERAND (arg0, 1),
10868 build_int_cst (TREE_TYPE (arg1), 0));
10870 /* (X ^ C1) op C2 can be rewritten as X op (C1 ^ C2). */
10871 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10872 && TREE_CODE (arg1) == INTEGER_CST
10873 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10874 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
10875 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg1),
10876 TREE_OPERAND (arg0, 1), arg1));
10878 /* Fold (~X & C) == 0 into (X & C) != 0 and (~X & C) != 0 into
10879 (X & C) == 0 when C is a single bit. */
10880 if (TREE_CODE (arg0) == BIT_AND_EXPR
10881 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_NOT_EXPR
10882 && integer_zerop (arg1)
10883 && integer_pow2p (TREE_OPERAND (arg0, 1)))
10885 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
10886 TREE_OPERAND (TREE_OPERAND (arg0, 0), 0),
10887 TREE_OPERAND (arg0, 1));
10888 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR,
10892 /* Fold ((X & C) ^ C) eq/ne 0 into (X & C) ne/eq 0, when the
10893 constant C is a power of two, i.e. a single bit. */
10894 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10895 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
10896 && integer_zerop (arg1)
10897 && integer_pow2p (TREE_OPERAND (arg0, 1))
10898 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
10899 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
10901 tree arg00 = TREE_OPERAND (arg0, 0);
10902 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
10903 arg00, build_int_cst (TREE_TYPE (arg00), 0));
10906 /* Likewise, fold ((X ^ C) & C) eq/ne 0 into (X & C) ne/eq 0,
10907 when is C is a power of two, i.e. a single bit. */
10908 if (TREE_CODE (arg0) == BIT_AND_EXPR
10909 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_XOR_EXPR
10910 && integer_zerop (arg1)
10911 && integer_pow2p (TREE_OPERAND (arg0, 1))
10912 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
10913 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
10915 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
10916 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg000),
10917 arg000, TREE_OPERAND (arg0, 1));
10918 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
10919 tem, build_int_cst (TREE_TYPE (tem), 0));
10922 if (integer_zerop (arg1)
10923 && tree_expr_nonzero_p (arg0))
10925 tree res = constant_boolean_node (code==NE_EXPR, type);
10926 return omit_one_operand (type, res, arg0);
10934 tem = fold_comparison (code, type, op0, op1);
10935 if (tem != NULL_TREE)
10938 /* Transform comparisons of the form X +- C CMP X. */
10939 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
10940 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10941 && ((TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
10942 && !HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0))))
10943 || (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
10944 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))))
10946 tree arg01 = TREE_OPERAND (arg0, 1);
10947 enum tree_code code0 = TREE_CODE (arg0);
10950 if (TREE_CODE (arg01) == REAL_CST)
10951 is_positive = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg01)) ? -1 : 1;
10953 is_positive = tree_int_cst_sgn (arg01);
10955 /* (X - c) > X becomes false. */
10956 if (code == GT_EXPR
10957 && ((code0 == MINUS_EXPR && is_positive >= 0)
10958 || (code0 == PLUS_EXPR && is_positive <= 0)))
10960 if (TREE_CODE (arg01) == INTEGER_CST
10961 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
10962 fold_overflow_warning (("assuming signed overflow does not "
10963 "occur when assuming that (X - c) > X "
10964 "is always false"),
10965 WARN_STRICT_OVERFLOW_ALL);
10966 return constant_boolean_node (0, type);
10969 /* Likewise (X + c) < X becomes false. */
10970 if (code == LT_EXPR
10971 && ((code0 == PLUS_EXPR && is_positive >= 0)
10972 || (code0 == MINUS_EXPR && is_positive <= 0)))
10974 if (TREE_CODE (arg01) == INTEGER_CST
10975 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
10976 fold_overflow_warning (("assuming signed overflow does not "
10977 "occur when assuming that "
10978 "(X + c) < X is always false"),
10979 WARN_STRICT_OVERFLOW_ALL);
10980 return constant_boolean_node (0, type);
10983 /* Convert (X - c) <= X to true. */
10984 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
10986 && ((code0 == MINUS_EXPR && is_positive >= 0)
10987 || (code0 == PLUS_EXPR && is_positive <= 0)))
10989 if (TREE_CODE (arg01) == INTEGER_CST
10990 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
10991 fold_overflow_warning (("assuming signed overflow does not "
10992 "occur when assuming that "
10993 "(X - c) <= X is always true"),
10994 WARN_STRICT_OVERFLOW_ALL);
10995 return constant_boolean_node (1, type);
10998 /* Convert (X + c) >= X to true. */
10999 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
11001 && ((code0 == PLUS_EXPR && is_positive >= 0)
11002 || (code0 == MINUS_EXPR && is_positive <= 0)))
11004 if (TREE_CODE (arg01) == INTEGER_CST
11005 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
11006 fold_overflow_warning (("assuming signed overflow does not "
11007 "occur when assuming that "
11008 "(X + c) >= X is always true"),
11009 WARN_STRICT_OVERFLOW_ALL);
11010 return constant_boolean_node (1, type);
11013 if (TREE_CODE (arg01) == INTEGER_CST)
11015 /* Convert X + c > X and X - c < X to true for integers. */
11016 if (code == GT_EXPR
11017 && ((code0 == PLUS_EXPR && is_positive > 0)
11018 || (code0 == MINUS_EXPR && is_positive < 0)))
11020 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
11021 fold_overflow_warning (("assuming signed overflow does "
11022 "not occur when assuming that "
11023 "(X + c) > X is always true"),
11024 WARN_STRICT_OVERFLOW_ALL);
11025 return constant_boolean_node (1, type);
11028 if (code == LT_EXPR
11029 && ((code0 == MINUS_EXPR && is_positive > 0)
11030 || (code0 == PLUS_EXPR && is_positive < 0)))
11032 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
11033 fold_overflow_warning (("assuming signed overflow does "
11034 "not occur when assuming that "
11035 "(X - c) < X is always true"),
11036 WARN_STRICT_OVERFLOW_ALL);
11037 return constant_boolean_node (1, type);
11040 /* Convert X + c <= X and X - c >= X to false for integers. */
11041 if (code == LE_EXPR
11042 && ((code0 == PLUS_EXPR && is_positive > 0)
11043 || (code0 == MINUS_EXPR && is_positive < 0)))
11045 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
11046 fold_overflow_warning (("assuming signed overflow does "
11047 "not occur when assuming that "
11048 "(X + c) <= X is always false"),
11049 WARN_STRICT_OVERFLOW_ALL);
11050 return constant_boolean_node (0, type);
11053 if (code == GE_EXPR
11054 && ((code0 == MINUS_EXPR && is_positive > 0)
11055 || (code0 == PLUS_EXPR && is_positive < 0)))
11057 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
11058 fold_overflow_warning (("assuming signed overflow does "
11059 "not occur when assuming that "
11060 "(X - c) >= X is always true"),
11061 WARN_STRICT_OVERFLOW_ALL);
11062 return constant_boolean_node (0, type);
11067 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
11068 This transformation affects the cases which are handled in later
11069 optimizations involving comparisons with non-negative constants. */
11070 if (TREE_CODE (arg1) == INTEGER_CST
11071 && TREE_CODE (arg0) != INTEGER_CST
11072 && tree_int_cst_sgn (arg1) > 0)
11074 if (code == GE_EXPR)
11076 arg1 = const_binop (MINUS_EXPR, arg1,
11077 build_int_cst (TREE_TYPE (arg1), 1), 0);
11078 return fold_build2 (GT_EXPR, type, arg0,
11079 fold_convert (TREE_TYPE (arg0), arg1));
11081 if (code == LT_EXPR)
11083 arg1 = const_binop (MINUS_EXPR, arg1,
11084 build_int_cst (TREE_TYPE (arg1), 1), 0);
11085 return fold_build2 (LE_EXPR, type, arg0,
11086 fold_convert (TREE_TYPE (arg0), arg1));
11090 /* Comparisons with the highest or lowest possible integer of
11091 the specified size will have known values. */
11093 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
11095 if (TREE_CODE (arg1) == INTEGER_CST
11096 && ! TREE_CONSTANT_OVERFLOW (arg1)
11097 && width <= 2 * HOST_BITS_PER_WIDE_INT
11098 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
11099 || POINTER_TYPE_P (TREE_TYPE (arg1))))
11101 HOST_WIDE_INT signed_max_hi;
11102 unsigned HOST_WIDE_INT signed_max_lo;
11103 unsigned HOST_WIDE_INT max_hi, max_lo, min_hi, min_lo;
11105 if (width <= HOST_BITS_PER_WIDE_INT)
11107 signed_max_lo = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
11112 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
11114 max_lo = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
11120 max_lo = signed_max_lo;
11121 min_lo = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
11127 width -= HOST_BITS_PER_WIDE_INT;
11128 signed_max_lo = -1;
11129 signed_max_hi = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
11134 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
11136 max_hi = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
11141 max_hi = signed_max_hi;
11142 min_hi = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
11146 if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1) == max_hi
11147 && TREE_INT_CST_LOW (arg1) == max_lo)
11151 return omit_one_operand (type, integer_zero_node, arg0);
11154 return fold_build2 (EQ_EXPR, type, op0, op1);
11157 return omit_one_operand (type, integer_one_node, arg0);
11160 return fold_build2 (NE_EXPR, type, op0, op1);
11162 /* The GE_EXPR and LT_EXPR cases above are not normally
11163 reached because of previous transformations. */
11168 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
11170 && TREE_INT_CST_LOW (arg1) == max_lo - 1)
11174 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
11175 return fold_build2 (EQ_EXPR, type,
11176 fold_convert (TREE_TYPE (arg1), arg0),
11179 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
11180 return fold_build2 (NE_EXPR, type,
11181 fold_convert (TREE_TYPE (arg1), arg0),
11186 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
11188 && TREE_INT_CST_LOW (arg1) == min_lo)
11192 return omit_one_operand (type, integer_zero_node, arg0);
11195 return fold_build2 (EQ_EXPR, type, op0, op1);
11198 return omit_one_operand (type, integer_one_node, arg0);
11201 return fold_build2 (NE_EXPR, type, op0, op1);
11206 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
11208 && TREE_INT_CST_LOW (arg1) == min_lo + 1)
11212 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
11213 return fold_build2 (NE_EXPR, type,
11214 fold_convert (TREE_TYPE (arg1), arg0),
11217 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
11218 return fold_build2 (EQ_EXPR, type,
11219 fold_convert (TREE_TYPE (arg1), arg0),
11225 else if (!in_gimple_form
11226 && TREE_INT_CST_HIGH (arg1) == signed_max_hi
11227 && TREE_INT_CST_LOW (arg1) == signed_max_lo
11228 && TYPE_UNSIGNED (TREE_TYPE (arg1))
11229 /* signed_type does not work on pointer types. */
11230 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
11232 /* The following case also applies to X < signed_max+1
11233 and X >= signed_max+1 because previous transformations. */
11234 if (code == LE_EXPR || code == GT_EXPR)
11237 st = lang_hooks.types.signed_type (TREE_TYPE (arg1));
11238 return fold_build2 (code == LE_EXPR ? GE_EXPR : LT_EXPR,
11239 type, fold_convert (st, arg0),
11240 build_int_cst (st, 0));
11246 /* If we are comparing an ABS_EXPR with a constant, we can
11247 convert all the cases into explicit comparisons, but they may
11248 well not be faster than doing the ABS and one comparison.
11249 But ABS (X) <= C is a range comparison, which becomes a subtraction
11250 and a comparison, and is probably faster. */
11251 if (code == LE_EXPR
11252 && TREE_CODE (arg1) == INTEGER_CST
11253 && TREE_CODE (arg0) == ABS_EXPR
11254 && ! TREE_SIDE_EFFECTS (arg0)
11255 && (0 != (tem = negate_expr (arg1)))
11256 && TREE_CODE (tem) == INTEGER_CST
11257 && ! TREE_CONSTANT_OVERFLOW (tem))
11258 return fold_build2 (TRUTH_ANDIF_EXPR, type,
11259 build2 (GE_EXPR, type,
11260 TREE_OPERAND (arg0, 0), tem),
11261 build2 (LE_EXPR, type,
11262 TREE_OPERAND (arg0, 0), arg1));
11264 /* Convert ABS_EXPR<x> >= 0 to true. */
11265 strict_overflow_p = false;
11266 if (code == GE_EXPR
11267 && (integer_zerop (arg1)
11268 || (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
11269 && real_zerop (arg1)))
11270 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
11272 if (strict_overflow_p)
11273 fold_overflow_warning (("assuming signed overflow does not occur "
11274 "when simplifying comparison of "
11275 "absolute value and zero"),
11276 WARN_STRICT_OVERFLOW_CONDITIONAL);
11277 return omit_one_operand (type, integer_one_node, arg0);
11280 /* Convert ABS_EXPR<x> < 0 to false. */
11281 strict_overflow_p = false;
11282 if (code == LT_EXPR
11283 && (integer_zerop (arg1) || real_zerop (arg1))
11284 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
11286 if (strict_overflow_p)
11287 fold_overflow_warning (("assuming signed overflow does not occur "
11288 "when simplifying comparison of "
11289 "absolute value and zero"),
11290 WARN_STRICT_OVERFLOW_CONDITIONAL);
11291 return omit_one_operand (type, integer_zero_node, arg0);
11294 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
11295 and similarly for >= into !=. */
11296 if ((code == LT_EXPR || code == GE_EXPR)
11297 && TYPE_UNSIGNED (TREE_TYPE (arg0))
11298 && TREE_CODE (arg1) == LSHIFT_EXPR
11299 && integer_onep (TREE_OPERAND (arg1, 0)))
11300 return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
11301 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
11302 TREE_OPERAND (arg1, 1)),
11303 build_int_cst (TREE_TYPE (arg0), 0));
11305 if ((code == LT_EXPR || code == GE_EXPR)
11306 && TYPE_UNSIGNED (TREE_TYPE (arg0))
11307 && (TREE_CODE (arg1) == NOP_EXPR
11308 || TREE_CODE (arg1) == CONVERT_EXPR)
11309 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
11310 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
11312 build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
11313 fold_convert (TREE_TYPE (arg0),
11314 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
11315 TREE_OPERAND (TREE_OPERAND (arg1, 0),
11317 build_int_cst (TREE_TYPE (arg0), 0));
11321 case UNORDERED_EXPR:
11329 if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
11331 t1 = fold_relational_const (code, type, arg0, arg1);
11332 if (t1 != NULL_TREE)
11336 /* If the first operand is NaN, the result is constant. */
11337 if (TREE_CODE (arg0) == REAL_CST
11338 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
11339 && (code != LTGT_EXPR || ! flag_trapping_math))
11341 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
11342 ? integer_zero_node
11343 : integer_one_node;
11344 return omit_one_operand (type, t1, arg1);
11347 /* If the second operand is NaN, the result is constant. */
11348 if (TREE_CODE (arg1) == REAL_CST
11349 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
11350 && (code != LTGT_EXPR || ! flag_trapping_math))
11352 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
11353 ? integer_zero_node
11354 : integer_one_node;
11355 return omit_one_operand (type, t1, arg0);
11358 /* Simplify unordered comparison of something with itself. */
11359 if ((code == UNLE_EXPR || code == UNGE_EXPR || code == UNEQ_EXPR)
11360 && operand_equal_p (arg0, arg1, 0))
11361 return constant_boolean_node (1, type);
11363 if (code == LTGT_EXPR
11364 && !flag_trapping_math
11365 && operand_equal_p (arg0, arg1, 0))
11366 return constant_boolean_node (0, type);
11368 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
11370 tree targ0 = strip_float_extensions (arg0);
11371 tree targ1 = strip_float_extensions (arg1);
11372 tree newtype = TREE_TYPE (targ0);
11374 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
11375 newtype = TREE_TYPE (targ1);
11377 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
11378 return fold_build2 (code, type, fold_convert (newtype, targ0),
11379 fold_convert (newtype, targ1));
11384 case COMPOUND_EXPR:
11385 /* When pedantic, a compound expression can be neither an lvalue
11386 nor an integer constant expression. */
11387 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
11389 /* Don't let (0, 0) be null pointer constant. */
11390 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
11391 : fold_convert (type, arg1);
11392 return pedantic_non_lvalue (tem);
11395 if ((TREE_CODE (arg0) == REAL_CST
11396 && TREE_CODE (arg1) == REAL_CST)
11397 || (TREE_CODE (arg0) == INTEGER_CST
11398 && TREE_CODE (arg1) == INTEGER_CST))
11399 return build_complex (type, arg0, arg1);
11403 /* An ASSERT_EXPR should never be passed to fold_binary. */
11404 gcc_unreachable ();
11408 } /* switch (code) */
11411 /* Callback for walk_tree, looking for LABEL_EXPR.
11412 Returns tree TP if it is LABEL_EXPR. Otherwise it returns NULL_TREE.
11413 Do not check the sub-tree of GOTO_EXPR. */
11416 contains_label_1 (tree *tp,
11417 int *walk_subtrees,
11418 void *data ATTRIBUTE_UNUSED)
11420 switch (TREE_CODE (*tp))
11425 *walk_subtrees = 0;
11432 /* Checks whether the sub-tree ST contains a label LABEL_EXPR which is
11433 accessible from outside the sub-tree. Returns NULL_TREE if no
11434 addressable label is found. */
11437 contains_label_p (tree st)
11439 return (walk_tree (&st, contains_label_1 , NULL, NULL) != NULL_TREE);
11442 /* Fold a ternary expression of code CODE and type TYPE with operands
11443 OP0, OP1, and OP2. Return the folded expression if folding is
11444 successful. Otherwise, return NULL_TREE. */
11447 fold_ternary (enum tree_code code, tree type, tree op0, tree op1, tree op2)
11450 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
11451 enum tree_code_class kind = TREE_CODE_CLASS (code);
11453 gcc_assert (IS_EXPR_CODE_CLASS (kind)
11454 && TREE_CODE_LENGTH (code) == 3);
11456 /* Strip any conversions that don't change the mode. This is safe
11457 for every expression, except for a comparison expression because
11458 its signedness is derived from its operands. So, in the latter
11459 case, only strip conversions that don't change the signedness.
11461 Note that this is done as an internal manipulation within the
11462 constant folder, in order to find the simplest representation of
11463 the arguments so that their form can be studied. In any cases,
11464 the appropriate type conversions should be put back in the tree
11465 that will get out of the constant folder. */
11480 case COMPONENT_REF:
11481 if (TREE_CODE (arg0) == CONSTRUCTOR
11482 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
11484 unsigned HOST_WIDE_INT idx;
11486 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg0), idx, field, value)
11493 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
11494 so all simple results must be passed through pedantic_non_lvalue. */
11495 if (TREE_CODE (arg0) == INTEGER_CST)
11497 tree unused_op = integer_zerop (arg0) ? op1 : op2;
11498 tem = integer_zerop (arg0) ? op2 : op1;
11499 /* Only optimize constant conditions when the selected branch
11500 has the same type as the COND_EXPR. This avoids optimizing
11501 away "c ? x : throw", where the throw has a void type.
11502 Avoid throwing away that operand which contains label. */
11503 if ((!TREE_SIDE_EFFECTS (unused_op)
11504 || !contains_label_p (unused_op))
11505 && (! VOID_TYPE_P (TREE_TYPE (tem))
11506 || VOID_TYPE_P (type)))
11507 return pedantic_non_lvalue (tem);
11510 if (operand_equal_p (arg1, op2, 0))
11511 return pedantic_omit_one_operand (type, arg1, arg0);
11513 /* If we have A op B ? A : C, we may be able to convert this to a
11514 simpler expression, depending on the operation and the values
11515 of B and C. Signed zeros prevent all of these transformations,
11516 for reasons given above each one.
11518 Also try swapping the arguments and inverting the conditional. */
11519 if (COMPARISON_CLASS_P (arg0)
11520 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
11521 arg1, TREE_OPERAND (arg0, 1))
11522 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
11524 tem = fold_cond_expr_with_comparison (type, arg0, op1, op2);
11529 if (COMPARISON_CLASS_P (arg0)
11530 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
11532 TREE_OPERAND (arg0, 1))
11533 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op2))))
11535 tem = fold_truth_not_expr (arg0);
11536 if (tem && COMPARISON_CLASS_P (tem))
11538 tem = fold_cond_expr_with_comparison (type, tem, op2, op1);
11544 /* If the second operand is simpler than the third, swap them
11545 since that produces better jump optimization results. */
11546 if (truth_value_p (TREE_CODE (arg0))
11547 && tree_swap_operands_p (op1, op2, false))
11549 /* See if this can be inverted. If it can't, possibly because
11550 it was a floating-point inequality comparison, don't do
11552 tem = fold_truth_not_expr (arg0);
11554 return fold_build3 (code, type, tem, op2, op1);
11557 /* Convert A ? 1 : 0 to simply A. */
11558 if (integer_onep (op1)
11559 && integer_zerop (op2)
11560 /* If we try to convert OP0 to our type, the
11561 call to fold will try to move the conversion inside
11562 a COND, which will recurse. In that case, the COND_EXPR
11563 is probably the best choice, so leave it alone. */
11564 && type == TREE_TYPE (arg0))
11565 return pedantic_non_lvalue (arg0);
11567 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
11568 over COND_EXPR in cases such as floating point comparisons. */
11569 if (integer_zerop (op1)
11570 && integer_onep (op2)
11571 && truth_value_p (TREE_CODE (arg0)))
11572 return pedantic_non_lvalue (fold_convert (type,
11573 invert_truthvalue (arg0)));
11575 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
11576 if (TREE_CODE (arg0) == LT_EXPR
11577 && integer_zerop (TREE_OPERAND (arg0, 1))
11578 && integer_zerop (op2)
11579 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
11581 /* sign_bit_p only checks ARG1 bits within A's precision.
11582 If <sign bit of A> has wider type than A, bits outside
11583 of A's precision in <sign bit of A> need to be checked.
11584 If they are all 0, this optimization needs to be done
11585 in unsigned A's type, if they are all 1 in signed A's type,
11586 otherwise this can't be done. */
11587 if (TYPE_PRECISION (TREE_TYPE (tem))
11588 < TYPE_PRECISION (TREE_TYPE (arg1))
11589 && TYPE_PRECISION (TREE_TYPE (tem))
11590 < TYPE_PRECISION (type))
11592 unsigned HOST_WIDE_INT mask_lo;
11593 HOST_WIDE_INT mask_hi;
11594 int inner_width, outer_width;
11597 inner_width = TYPE_PRECISION (TREE_TYPE (tem));
11598 outer_width = TYPE_PRECISION (TREE_TYPE (arg1));
11599 if (outer_width > TYPE_PRECISION (type))
11600 outer_width = TYPE_PRECISION (type);
11602 if (outer_width > HOST_BITS_PER_WIDE_INT)
11604 mask_hi = ((unsigned HOST_WIDE_INT) -1
11605 >> (2 * HOST_BITS_PER_WIDE_INT - outer_width));
11611 mask_lo = ((unsigned HOST_WIDE_INT) -1
11612 >> (HOST_BITS_PER_WIDE_INT - outer_width));
11614 if (inner_width > HOST_BITS_PER_WIDE_INT)
11616 mask_hi &= ~((unsigned HOST_WIDE_INT) -1
11617 >> (HOST_BITS_PER_WIDE_INT - inner_width));
11621 mask_lo &= ~((unsigned HOST_WIDE_INT) -1
11622 >> (HOST_BITS_PER_WIDE_INT - inner_width));
11624 if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == mask_hi
11625 && (TREE_INT_CST_LOW (arg1) & mask_lo) == mask_lo)
11627 tem_type = lang_hooks.types.signed_type (TREE_TYPE (tem));
11628 tem = fold_convert (tem_type, tem);
11630 else if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == 0
11631 && (TREE_INT_CST_LOW (arg1) & mask_lo) == 0)
11633 tem_type = lang_hooks.types.unsigned_type (TREE_TYPE (tem));
11634 tem = fold_convert (tem_type, tem);
11641 return fold_convert (type,
11642 fold_build2 (BIT_AND_EXPR,
11643 TREE_TYPE (tem), tem,
11644 fold_convert (TREE_TYPE (tem),
11648 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
11649 already handled above. */
11650 if (TREE_CODE (arg0) == BIT_AND_EXPR
11651 && integer_onep (TREE_OPERAND (arg0, 1))
11652 && integer_zerop (op2)
11653 && integer_pow2p (arg1))
11655 tree tem = TREE_OPERAND (arg0, 0);
11657 if (TREE_CODE (tem) == RSHIFT_EXPR
11658 && TREE_CODE (TREE_OPERAND (tem, 1)) == INTEGER_CST
11659 && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
11660 TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
11661 return fold_build2 (BIT_AND_EXPR, type,
11662 TREE_OPERAND (tem, 0), arg1);
11665 /* A & N ? N : 0 is simply A & N if N is a power of two. This
11666 is probably obsolete because the first operand should be a
11667 truth value (that's why we have the two cases above), but let's
11668 leave it in until we can confirm this for all front-ends. */
11669 if (integer_zerop (op2)
11670 && TREE_CODE (arg0) == NE_EXPR
11671 && integer_zerop (TREE_OPERAND (arg0, 1))
11672 && integer_pow2p (arg1)
11673 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
11674 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
11675 arg1, OEP_ONLY_CONST))
11676 return pedantic_non_lvalue (fold_convert (type,
11677 TREE_OPERAND (arg0, 0)));
11679 /* Convert A ? B : 0 into A && B if A and B are truth values. */
11680 if (integer_zerop (op2)
11681 && truth_value_p (TREE_CODE (arg0))
11682 && truth_value_p (TREE_CODE (arg1)))
11683 return fold_build2 (TRUTH_ANDIF_EXPR, type,
11684 fold_convert (type, arg0),
11687 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
11688 if (integer_onep (op2)
11689 && truth_value_p (TREE_CODE (arg0))
11690 && truth_value_p (TREE_CODE (arg1)))
11692 /* Only perform transformation if ARG0 is easily inverted. */
11693 tem = fold_truth_not_expr (arg0);
11695 return fold_build2 (TRUTH_ORIF_EXPR, type,
11696 fold_convert (type, tem),
11700 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
11701 if (integer_zerop (arg1)
11702 && truth_value_p (TREE_CODE (arg0))
11703 && truth_value_p (TREE_CODE (op2)))
11705 /* Only perform transformation if ARG0 is easily inverted. */
11706 tem = fold_truth_not_expr (arg0);
11708 return fold_build2 (TRUTH_ANDIF_EXPR, type,
11709 fold_convert (type, tem),
11713 /* Convert A ? 1 : B into A || B if A and B are truth values. */
11714 if (integer_onep (arg1)
11715 && truth_value_p (TREE_CODE (arg0))
11716 && truth_value_p (TREE_CODE (op2)))
11717 return fold_build2 (TRUTH_ORIF_EXPR, type,
11718 fold_convert (type, arg0),
11724 /* Check for a built-in function. */
11725 if (TREE_CODE (op0) == ADDR_EXPR
11726 && TREE_CODE (TREE_OPERAND (op0, 0)) == FUNCTION_DECL
11727 && DECL_BUILT_IN (TREE_OPERAND (op0, 0)))
11728 return fold_builtin (TREE_OPERAND (op0, 0), op1, false);
11731 case BIT_FIELD_REF:
11732 if (TREE_CODE (arg0) == VECTOR_CST
11733 && type == TREE_TYPE (TREE_TYPE (arg0))
11734 && host_integerp (arg1, 1)
11735 && host_integerp (op2, 1))
11737 unsigned HOST_WIDE_INT width = tree_low_cst (arg1, 1);
11738 unsigned HOST_WIDE_INT idx = tree_low_cst (op2, 1);
11741 && simple_cst_equal (arg1, TYPE_SIZE (type)) == 1
11742 && (idx % width) == 0
11743 && (idx = idx / width)
11744 < TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0)))
11746 tree elements = TREE_VECTOR_CST_ELTS (arg0);
11747 while (idx-- > 0 && elements)
11748 elements = TREE_CHAIN (elements);
11750 return TREE_VALUE (elements);
11752 return fold_convert (type, integer_zero_node);
11759 } /* switch (code) */
11762 /* Perform constant folding and related simplification of EXPR.
11763 The related simplifications include x*1 => x, x*0 => 0, etc.,
11764 and application of the associative law.
11765 NOP_EXPR conversions may be removed freely (as long as we
11766 are careful not to change the type of the overall expression).
11767 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
11768 but we can constant-fold them if they have constant operands. */
11770 #ifdef ENABLE_FOLD_CHECKING
11771 # define fold(x) fold_1 (x)
11772 static tree fold_1 (tree);
11778 const tree t = expr;
11779 enum tree_code code = TREE_CODE (t);
11780 enum tree_code_class kind = TREE_CODE_CLASS (code);
11783 /* Return right away if a constant. */
11784 if (kind == tcc_constant)
11787 if (IS_EXPR_CODE_CLASS (kind))
11789 tree type = TREE_TYPE (t);
11790 tree op0, op1, op2;
11792 switch (TREE_CODE_LENGTH (code))
11795 op0 = TREE_OPERAND (t, 0);
11796 tem = fold_unary (code, type, op0);
11797 return tem ? tem : expr;
11799 op0 = TREE_OPERAND (t, 0);
11800 op1 = TREE_OPERAND (t, 1);
11801 tem = fold_binary (code, type, op0, op1);
11802 return tem ? tem : expr;
11804 op0 = TREE_OPERAND (t, 0);
11805 op1 = TREE_OPERAND (t, 1);
11806 op2 = TREE_OPERAND (t, 2);
11807 tem = fold_ternary (code, type, op0, op1, op2);
11808 return tem ? tem : expr;
11817 return fold (DECL_INITIAL (t));
11821 } /* switch (code) */
11824 #ifdef ENABLE_FOLD_CHECKING
11827 static void fold_checksum_tree (tree, struct md5_ctx *, htab_t);
11828 static void fold_check_failed (tree, tree);
11829 void print_fold_checksum (tree);
11831 /* When --enable-checking=fold, compute a digest of expr before
11832 and after actual fold call to see if fold did not accidentally
11833 change original expr. */
11839 struct md5_ctx ctx;
11840 unsigned char checksum_before[16], checksum_after[16];
11843 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
11844 md5_init_ctx (&ctx);
11845 fold_checksum_tree (expr, &ctx, ht);
11846 md5_finish_ctx (&ctx, checksum_before);
11849 ret = fold_1 (expr);
11851 md5_init_ctx (&ctx);
11852 fold_checksum_tree (expr, &ctx, ht);
11853 md5_finish_ctx (&ctx, checksum_after);
11856 if (memcmp (checksum_before, checksum_after, 16))
11857 fold_check_failed (expr, ret);
11863 print_fold_checksum (tree expr)
11865 struct md5_ctx ctx;
11866 unsigned char checksum[16], cnt;
11869 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
11870 md5_init_ctx (&ctx);
11871 fold_checksum_tree (expr, &ctx, ht);
11872 md5_finish_ctx (&ctx, checksum);
11874 for (cnt = 0; cnt < 16; ++cnt)
11875 fprintf (stderr, "%02x", checksum[cnt]);
11876 putc ('\n', stderr);
11880 fold_check_failed (tree expr ATTRIBUTE_UNUSED, tree ret ATTRIBUTE_UNUSED)
11882 internal_error ("fold check: original tree changed by fold");
11886 fold_checksum_tree (tree expr, struct md5_ctx *ctx, htab_t ht)
11889 enum tree_code code;
11890 struct tree_function_decl buf;
11895 gcc_assert ((sizeof (struct tree_exp) + 5 * sizeof (tree)
11896 <= sizeof (struct tree_function_decl))
11897 && sizeof (struct tree_type) <= sizeof (struct tree_function_decl));
11900 slot = htab_find_slot (ht, expr, INSERT);
11904 code = TREE_CODE (expr);
11905 if (TREE_CODE_CLASS (code) == tcc_declaration
11906 && DECL_ASSEMBLER_NAME_SET_P (expr))
11908 /* Allow DECL_ASSEMBLER_NAME to be modified. */
11909 memcpy ((char *) &buf, expr, tree_size (expr));
11910 expr = (tree) &buf;
11911 SET_DECL_ASSEMBLER_NAME (expr, NULL);
11913 else if (TREE_CODE_CLASS (code) == tcc_type
11914 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)
11915 || TYPE_CACHED_VALUES_P (expr)
11916 || TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr)))
11918 /* Allow these fields to be modified. */
11919 memcpy ((char *) &buf, expr, tree_size (expr));
11920 expr = (tree) &buf;
11921 TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr) = 0;
11922 TYPE_POINTER_TO (expr) = NULL;
11923 TYPE_REFERENCE_TO (expr) = NULL;
11924 if (TYPE_CACHED_VALUES_P (expr))
11926 TYPE_CACHED_VALUES_P (expr) = 0;
11927 TYPE_CACHED_VALUES (expr) = NULL;
11930 md5_process_bytes (expr, tree_size (expr), ctx);
11931 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
11932 if (TREE_CODE_CLASS (code) != tcc_type
11933 && TREE_CODE_CLASS (code) != tcc_declaration
11934 && code != TREE_LIST)
11935 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
11936 switch (TREE_CODE_CLASS (code))
11942 md5_process_bytes (TREE_STRING_POINTER (expr),
11943 TREE_STRING_LENGTH (expr), ctx);
11946 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
11947 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
11950 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
11956 case tcc_exceptional:
11960 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
11961 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
11962 expr = TREE_CHAIN (expr);
11963 goto recursive_label;
11966 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
11967 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
11973 case tcc_expression:
11974 case tcc_reference:
11975 case tcc_comparison:
11978 case tcc_statement:
11979 len = TREE_CODE_LENGTH (code);
11980 for (i = 0; i < len; ++i)
11981 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
11983 case tcc_declaration:
11984 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
11985 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
11986 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_COMMON))
11988 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
11989 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
11990 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
11991 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
11992 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
11994 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_WITH_VIS))
11995 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
11997 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_NON_COMMON))
11999 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
12000 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
12001 fold_checksum_tree (DECL_ARGUMENT_FLD (expr), ctx, ht);
12005 if (TREE_CODE (expr) == ENUMERAL_TYPE)
12006 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
12007 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
12008 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
12009 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
12010 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
12011 if (INTEGRAL_TYPE_P (expr)
12012 || SCALAR_FLOAT_TYPE_P (expr))
12014 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
12015 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
12017 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
12018 if (TREE_CODE (expr) == RECORD_TYPE
12019 || TREE_CODE (expr) == UNION_TYPE
12020 || TREE_CODE (expr) == QUAL_UNION_TYPE)
12021 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
12022 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
12031 /* Fold a unary tree expression with code CODE of type TYPE with an
12032 operand OP0. Return a folded expression if successful. Otherwise,
12033 return a tree expression with code CODE of type TYPE with an
12037 fold_build1_stat (enum tree_code code, tree type, tree op0 MEM_STAT_DECL)
12040 #ifdef ENABLE_FOLD_CHECKING
12041 unsigned char checksum_before[16], checksum_after[16];
12042 struct md5_ctx ctx;
12045 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
12046 md5_init_ctx (&ctx);
12047 fold_checksum_tree (op0, &ctx, ht);
12048 md5_finish_ctx (&ctx, checksum_before);
12052 tem = fold_unary (code, type, op0);
12054 tem = build1_stat (code, type, op0 PASS_MEM_STAT);
12056 #ifdef ENABLE_FOLD_CHECKING
12057 md5_init_ctx (&ctx);
12058 fold_checksum_tree (op0, &ctx, ht);
12059 md5_finish_ctx (&ctx, checksum_after);
12062 if (memcmp (checksum_before, checksum_after, 16))
12063 fold_check_failed (op0, tem);
12068 /* Fold a binary tree expression with code CODE of type TYPE with
12069 operands OP0 and OP1. Return a folded expression if successful.
12070 Otherwise, return a tree expression with code CODE of type TYPE
12071 with operands OP0 and OP1. */
12074 fold_build2_stat (enum tree_code code, tree type, tree op0, tree op1
12078 #ifdef ENABLE_FOLD_CHECKING
12079 unsigned char checksum_before_op0[16],
12080 checksum_before_op1[16],
12081 checksum_after_op0[16],
12082 checksum_after_op1[16];
12083 struct md5_ctx ctx;
12086 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
12087 md5_init_ctx (&ctx);
12088 fold_checksum_tree (op0, &ctx, ht);
12089 md5_finish_ctx (&ctx, checksum_before_op0);
12092 md5_init_ctx (&ctx);
12093 fold_checksum_tree (op1, &ctx, ht);
12094 md5_finish_ctx (&ctx, checksum_before_op1);
12098 tem = fold_binary (code, type, op0, op1);
12100 tem = build2_stat (code, type, op0, op1 PASS_MEM_STAT);
12102 #ifdef ENABLE_FOLD_CHECKING
12103 md5_init_ctx (&ctx);
12104 fold_checksum_tree (op0, &ctx, ht);
12105 md5_finish_ctx (&ctx, checksum_after_op0);
12108 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
12109 fold_check_failed (op0, tem);
12111 md5_init_ctx (&ctx);
12112 fold_checksum_tree (op1, &ctx, ht);
12113 md5_finish_ctx (&ctx, checksum_after_op1);
12116 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
12117 fold_check_failed (op1, tem);
12122 /* Fold a ternary tree expression with code CODE of type TYPE with
12123 operands OP0, OP1, and OP2. Return a folded expression if
12124 successful. Otherwise, return a tree expression with code CODE of
12125 type TYPE with operands OP0, OP1, and OP2. */
12128 fold_build3_stat (enum tree_code code, tree type, tree op0, tree op1, tree op2
12132 #ifdef ENABLE_FOLD_CHECKING
12133 unsigned char checksum_before_op0[16],
12134 checksum_before_op1[16],
12135 checksum_before_op2[16],
12136 checksum_after_op0[16],
12137 checksum_after_op1[16],
12138 checksum_after_op2[16];
12139 struct md5_ctx ctx;
12142 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
12143 md5_init_ctx (&ctx);
12144 fold_checksum_tree (op0, &ctx, ht);
12145 md5_finish_ctx (&ctx, checksum_before_op0);
12148 md5_init_ctx (&ctx);
12149 fold_checksum_tree (op1, &ctx, ht);
12150 md5_finish_ctx (&ctx, checksum_before_op1);
12153 md5_init_ctx (&ctx);
12154 fold_checksum_tree (op2, &ctx, ht);
12155 md5_finish_ctx (&ctx, checksum_before_op2);
12159 tem = fold_ternary (code, type, op0, op1, op2);
12161 tem = build3_stat (code, type, op0, op1, op2 PASS_MEM_STAT);
12163 #ifdef ENABLE_FOLD_CHECKING
12164 md5_init_ctx (&ctx);
12165 fold_checksum_tree (op0, &ctx, ht);
12166 md5_finish_ctx (&ctx, checksum_after_op0);
12169 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
12170 fold_check_failed (op0, tem);
12172 md5_init_ctx (&ctx);
12173 fold_checksum_tree (op1, &ctx, ht);
12174 md5_finish_ctx (&ctx, checksum_after_op1);
12177 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
12178 fold_check_failed (op1, tem);
12180 md5_init_ctx (&ctx);
12181 fold_checksum_tree (op2, &ctx, ht);
12182 md5_finish_ctx (&ctx, checksum_after_op2);
12185 if (memcmp (checksum_before_op2, checksum_after_op2, 16))
12186 fold_check_failed (op2, tem);
12191 /* Perform constant folding and related simplification of initializer
12192 expression EXPR. These behave identically to "fold_buildN" but ignore
12193 potential run-time traps and exceptions that fold must preserve. */
12195 #define START_FOLD_INIT \
12196 int saved_signaling_nans = flag_signaling_nans;\
12197 int saved_trapping_math = flag_trapping_math;\
12198 int saved_rounding_math = flag_rounding_math;\
12199 int saved_trapv = flag_trapv;\
12200 int saved_folding_initializer = folding_initializer;\
12201 flag_signaling_nans = 0;\
12202 flag_trapping_math = 0;\
12203 flag_rounding_math = 0;\
12205 folding_initializer = 1;
12207 #define END_FOLD_INIT \
12208 flag_signaling_nans = saved_signaling_nans;\
12209 flag_trapping_math = saved_trapping_math;\
12210 flag_rounding_math = saved_rounding_math;\
12211 flag_trapv = saved_trapv;\
12212 folding_initializer = saved_folding_initializer;
12215 fold_build1_initializer (enum tree_code code, tree type, tree op)
12220 result = fold_build1 (code, type, op);
12227 fold_build2_initializer (enum tree_code code, tree type, tree op0, tree op1)
12232 result = fold_build2 (code, type, op0, op1);
12239 fold_build3_initializer (enum tree_code code, tree type, tree op0, tree op1,
12245 result = fold_build3 (code, type, op0, op1, op2);
12251 #undef START_FOLD_INIT
12252 #undef END_FOLD_INIT
12254 /* Determine if first argument is a multiple of second argument. Return 0 if
12255 it is not, or we cannot easily determined it to be.
12257 An example of the sort of thing we care about (at this point; this routine
12258 could surely be made more general, and expanded to do what the *_DIV_EXPR's
12259 fold cases do now) is discovering that
12261 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
12267 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
12269 This code also handles discovering that
12271 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
12273 is a multiple of 8 so we don't have to worry about dealing with a
12274 possible remainder.
12276 Note that we *look* inside a SAVE_EXPR only to determine how it was
12277 calculated; it is not safe for fold to do much of anything else with the
12278 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
12279 at run time. For example, the latter example above *cannot* be implemented
12280 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
12281 evaluation time of the original SAVE_EXPR is not necessarily the same at
12282 the time the new expression is evaluated. The only optimization of this
12283 sort that would be valid is changing
12285 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
12289 SAVE_EXPR (I) * SAVE_EXPR (J)
12291 (where the same SAVE_EXPR (J) is used in the original and the
12292 transformed version). */
12295 multiple_of_p (tree type, tree top, tree bottom)
12297 if (operand_equal_p (top, bottom, 0))
12300 if (TREE_CODE (type) != INTEGER_TYPE)
12303 switch (TREE_CODE (top))
12306 /* Bitwise and provides a power of two multiple. If the mask is
12307 a multiple of BOTTOM then TOP is a multiple of BOTTOM. */
12308 if (!integer_pow2p (bottom))
12313 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
12314 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
12318 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
12319 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
12322 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
12326 op1 = TREE_OPERAND (top, 1);
12327 /* const_binop may not detect overflow correctly,
12328 so check for it explicitly here. */
12329 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
12330 > TREE_INT_CST_LOW (op1)
12331 && TREE_INT_CST_HIGH (op1) == 0
12332 && 0 != (t1 = fold_convert (type,
12333 const_binop (LSHIFT_EXPR,
12336 && ! TREE_OVERFLOW (t1))
12337 return multiple_of_p (type, t1, bottom);
12342 /* Can't handle conversions from non-integral or wider integral type. */
12343 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
12344 || (TYPE_PRECISION (type)
12345 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
12348 /* .. fall through ... */
12351 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
12354 if (TREE_CODE (bottom) != INTEGER_CST
12355 || (TYPE_UNSIGNED (type)
12356 && (tree_int_cst_sgn (top) < 0
12357 || tree_int_cst_sgn (bottom) < 0)))
12359 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
12367 /* Return true if `t' is known to be non-negative. If the return
12368 value is based on the assumption that signed overflow is undefined,
12369 set *STRICT_OVERFLOW_P to true; otherwise, don't change
12370 *STRICT_OVERFLOW_P. */
12373 tree_expr_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
12375 if (t == error_mark_node)
12378 if (TYPE_UNSIGNED (TREE_TYPE (t)))
12381 switch (TREE_CODE (t))
12384 /* Query VRP to see if it has recorded any information about
12385 the range of this object. */
12386 return ssa_name_nonnegative_p (t);
12389 /* We can't return 1 if flag_wrapv is set because
12390 ABS_EXPR<INT_MIN> = INT_MIN. */
12391 if (!INTEGRAL_TYPE_P (TREE_TYPE (t)))
12393 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t)))
12395 *strict_overflow_p = true;
12401 return tree_int_cst_sgn (t) >= 0;
12404 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
12407 if (FLOAT_TYPE_P (TREE_TYPE (t)))
12408 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
12410 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
12411 strict_overflow_p));
12413 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
12414 both unsigned and at least 2 bits shorter than the result. */
12415 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
12416 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
12417 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
12419 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
12420 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
12421 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
12422 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
12424 unsigned int prec = MAX (TYPE_PRECISION (inner1),
12425 TYPE_PRECISION (inner2)) + 1;
12426 return prec < TYPE_PRECISION (TREE_TYPE (t));
12432 if (FLOAT_TYPE_P (TREE_TYPE (t)))
12434 /* x * x for floating point x is always non-negative. */
12435 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
12437 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
12439 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
12440 strict_overflow_p));
12443 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
12444 both unsigned and their total bits is shorter than the result. */
12445 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
12446 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
12447 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
12449 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
12450 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
12451 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
12452 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
12453 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
12454 < TYPE_PRECISION (TREE_TYPE (t));
12460 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
12462 || tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
12463 strict_overflow_p));
12469 case TRUNC_DIV_EXPR:
12470 case CEIL_DIV_EXPR:
12471 case FLOOR_DIV_EXPR:
12472 case ROUND_DIV_EXPR:
12473 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
12475 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
12476 strict_overflow_p));
12478 case TRUNC_MOD_EXPR:
12479 case CEIL_MOD_EXPR:
12480 case FLOOR_MOD_EXPR:
12481 case ROUND_MOD_EXPR:
12483 case NON_LVALUE_EXPR:
12485 case FIX_TRUNC_EXPR:
12486 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
12487 strict_overflow_p);
12489 case COMPOUND_EXPR:
12491 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
12492 strict_overflow_p);
12495 return tree_expr_nonnegative_warnv_p (expr_last (TREE_OPERAND (t, 1)),
12496 strict_overflow_p);
12499 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
12501 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 2),
12502 strict_overflow_p));
12506 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
12507 tree outer_type = TREE_TYPE (t);
12509 if (TREE_CODE (outer_type) == REAL_TYPE)
12511 if (TREE_CODE (inner_type) == REAL_TYPE)
12512 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
12513 strict_overflow_p);
12514 if (TREE_CODE (inner_type) == INTEGER_TYPE)
12516 if (TYPE_UNSIGNED (inner_type))
12518 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
12519 strict_overflow_p);
12522 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
12524 if (TREE_CODE (inner_type) == REAL_TYPE)
12525 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t,0),
12526 strict_overflow_p);
12527 if (TREE_CODE (inner_type) == INTEGER_TYPE)
12528 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
12529 && TYPE_UNSIGNED (inner_type);
12536 tree temp = TARGET_EXPR_SLOT (t);
12537 t = TARGET_EXPR_INITIAL (t);
12539 /* If the initializer is non-void, then it's a normal expression
12540 that will be assigned to the slot. */
12541 if (!VOID_TYPE_P (t))
12542 return tree_expr_nonnegative_warnv_p (t, strict_overflow_p);
12544 /* Otherwise, the initializer sets the slot in some way. One common
12545 way is an assignment statement at the end of the initializer. */
12548 if (TREE_CODE (t) == BIND_EXPR)
12549 t = expr_last (BIND_EXPR_BODY (t));
12550 else if (TREE_CODE (t) == TRY_FINALLY_EXPR
12551 || TREE_CODE (t) == TRY_CATCH_EXPR)
12552 t = expr_last (TREE_OPERAND (t, 0));
12553 else if (TREE_CODE (t) == STATEMENT_LIST)
12558 if (TREE_CODE (t) == MODIFY_EXPR
12559 && TREE_OPERAND (t, 0) == temp)
12560 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
12561 strict_overflow_p);
12568 tree fndecl = get_callee_fndecl (t);
12569 tree arglist = TREE_OPERAND (t, 1);
12570 if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
12571 switch (DECL_FUNCTION_CODE (fndecl))
12573 CASE_FLT_FN (BUILT_IN_ACOS):
12574 CASE_FLT_FN (BUILT_IN_ACOSH):
12575 CASE_FLT_FN (BUILT_IN_CABS):
12576 CASE_FLT_FN (BUILT_IN_COSH):
12577 CASE_FLT_FN (BUILT_IN_ERFC):
12578 CASE_FLT_FN (BUILT_IN_EXP):
12579 CASE_FLT_FN (BUILT_IN_EXP10):
12580 CASE_FLT_FN (BUILT_IN_EXP2):
12581 CASE_FLT_FN (BUILT_IN_FABS):
12582 CASE_FLT_FN (BUILT_IN_FDIM):
12583 CASE_FLT_FN (BUILT_IN_HYPOT):
12584 CASE_FLT_FN (BUILT_IN_POW10):
12585 CASE_INT_FN (BUILT_IN_FFS):
12586 CASE_INT_FN (BUILT_IN_PARITY):
12587 CASE_INT_FN (BUILT_IN_POPCOUNT):
12591 CASE_FLT_FN (BUILT_IN_SQRT):
12592 /* sqrt(-0.0) is -0.0. */
12593 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (t))))
12595 return tree_expr_nonnegative_warnv_p (TREE_VALUE (arglist),
12596 strict_overflow_p);
12598 CASE_FLT_FN (BUILT_IN_ASINH):
12599 CASE_FLT_FN (BUILT_IN_ATAN):
12600 CASE_FLT_FN (BUILT_IN_ATANH):
12601 CASE_FLT_FN (BUILT_IN_CBRT):
12602 CASE_FLT_FN (BUILT_IN_CEIL):
12603 CASE_FLT_FN (BUILT_IN_ERF):
12604 CASE_FLT_FN (BUILT_IN_EXPM1):
12605 CASE_FLT_FN (BUILT_IN_FLOOR):
12606 CASE_FLT_FN (BUILT_IN_FMOD):
12607 CASE_FLT_FN (BUILT_IN_FREXP):
12608 CASE_FLT_FN (BUILT_IN_LCEIL):
12609 CASE_FLT_FN (BUILT_IN_LDEXP):
12610 CASE_FLT_FN (BUILT_IN_LFLOOR):
12611 CASE_FLT_FN (BUILT_IN_LLCEIL):
12612 CASE_FLT_FN (BUILT_IN_LLFLOOR):
12613 CASE_FLT_FN (BUILT_IN_LLRINT):
12614 CASE_FLT_FN (BUILT_IN_LLROUND):
12615 CASE_FLT_FN (BUILT_IN_LRINT):
12616 CASE_FLT_FN (BUILT_IN_LROUND):
12617 CASE_FLT_FN (BUILT_IN_MODF):
12618 CASE_FLT_FN (BUILT_IN_NEARBYINT):
12619 CASE_FLT_FN (BUILT_IN_POW):
12620 CASE_FLT_FN (BUILT_IN_RINT):
12621 CASE_FLT_FN (BUILT_IN_ROUND):
12622 CASE_FLT_FN (BUILT_IN_SIGNBIT):
12623 CASE_FLT_FN (BUILT_IN_SINH):
12624 CASE_FLT_FN (BUILT_IN_TANH):
12625 CASE_FLT_FN (BUILT_IN_TRUNC):
12626 /* True if the 1st argument is nonnegative. */
12627 return tree_expr_nonnegative_warnv_p (TREE_VALUE (arglist),
12628 strict_overflow_p);
12630 CASE_FLT_FN (BUILT_IN_FMAX):
12631 /* True if the 1st OR 2nd arguments are nonnegative. */
12632 return (tree_expr_nonnegative_warnv_p (TREE_VALUE (arglist),
12634 || (tree_expr_nonnegative_warnv_p
12635 (TREE_VALUE (TREE_CHAIN (arglist)),
12636 strict_overflow_p)));
12638 CASE_FLT_FN (BUILT_IN_FMIN):
12639 /* True if the 1st AND 2nd arguments are nonnegative. */
12640 return (tree_expr_nonnegative_warnv_p (TREE_VALUE (arglist),
12642 && (tree_expr_nonnegative_warnv_p
12643 (TREE_VALUE (TREE_CHAIN (arglist)),
12644 strict_overflow_p)));
12646 CASE_FLT_FN (BUILT_IN_COPYSIGN):
12647 /* True if the 2nd argument is nonnegative. */
12648 return (tree_expr_nonnegative_warnv_p
12649 (TREE_VALUE (TREE_CHAIN (arglist)),
12650 strict_overflow_p));
12657 /* ... fall through ... */
12661 tree type = TREE_TYPE (t);
12662 if ((TYPE_PRECISION (type) != 1 || TYPE_UNSIGNED (type))
12663 && truth_value_p (TREE_CODE (t)))
12664 /* Truth values evaluate to 0 or 1, which is nonnegative unless we
12665 have a signed:1 type (where the value is -1 and 0). */
12670 /* We don't know sign of `t', so be conservative and return false. */
12674 /* Return true if `t' is known to be non-negative. Handle warnings
12675 about undefined signed overflow. */
12678 tree_expr_nonnegative_p (tree t)
12681 bool strict_overflow_p;
12683 strict_overflow_p = false;
12684 ret = tree_expr_nonnegative_warnv_p (t, &strict_overflow_p);
12685 if (strict_overflow_p)
12686 fold_overflow_warning (("assuming signed overflow does not occur when "
12687 "determining that expression is always "
12689 WARN_STRICT_OVERFLOW_MISC);
12693 /* Return true when T is an address and is known to be nonzero.
12694 For floating point we further ensure that T is not denormal.
12695 Similar logic is present in nonzero_address in rtlanal.h.
12697 If the return value is based on the assumption that signed overflow
12698 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
12699 change *STRICT_OVERFLOW_P. */
12702 tree_expr_nonzero_warnv_p (tree t, bool *strict_overflow_p)
12704 tree type = TREE_TYPE (t);
12705 bool sub_strict_overflow_p;
12707 /* Doing something useful for floating point would need more work. */
12708 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
12711 switch (TREE_CODE (t))
12714 /* Query VRP to see if it has recorded any information about
12715 the range of this object. */
12716 return ssa_name_nonzero_p (t);
12719 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
12720 strict_overflow_p);
12723 /* We used to test for !integer_zerop here. This does not work correctly
12724 if TREE_CONSTANT_OVERFLOW (t). */
12725 return (TREE_INT_CST_LOW (t) != 0
12726 || TREE_INT_CST_HIGH (t) != 0);
12729 if (TYPE_OVERFLOW_UNDEFINED (type))
12731 /* With the presence of negative values it is hard
12732 to say something. */
12733 sub_strict_overflow_p = false;
12734 if (!tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
12735 &sub_strict_overflow_p)
12736 || !tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
12737 &sub_strict_overflow_p))
12739 /* One of operands must be positive and the other non-negative. */
12740 /* We don't set *STRICT_OVERFLOW_P here: even if this value
12741 overflows, on a twos-complement machine the sum of two
12742 nonnegative numbers can never be zero. */
12743 return (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
12745 || tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
12746 strict_overflow_p));
12751 if (TYPE_OVERFLOW_UNDEFINED (type))
12753 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
12755 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
12756 strict_overflow_p))
12758 *strict_overflow_p = true;
12766 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
12767 tree outer_type = TREE_TYPE (t);
12769 return (TYPE_PRECISION (outer_type) >= TYPE_PRECISION (inner_type)
12770 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
12771 strict_overflow_p));
12777 tree base = get_base_address (TREE_OPERAND (t, 0));
12782 /* Weak declarations may link to NULL. */
12783 if (VAR_OR_FUNCTION_DECL_P (base))
12784 return !DECL_WEAK (base);
12786 /* Constants are never weak. */
12787 if (CONSTANT_CLASS_P (base))
12794 sub_strict_overflow_p = false;
12795 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
12796 &sub_strict_overflow_p)
12797 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 2),
12798 &sub_strict_overflow_p))
12800 if (sub_strict_overflow_p)
12801 *strict_overflow_p = true;
12807 sub_strict_overflow_p = false;
12808 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
12809 &sub_strict_overflow_p)
12810 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
12811 &sub_strict_overflow_p))
12813 if (sub_strict_overflow_p)
12814 *strict_overflow_p = true;
12819 sub_strict_overflow_p = false;
12820 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
12821 &sub_strict_overflow_p))
12823 if (sub_strict_overflow_p)
12824 *strict_overflow_p = true;
12826 /* When both operands are nonzero, then MAX must be too. */
12827 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
12828 strict_overflow_p))
12831 /* MAX where operand 0 is positive is positive. */
12832 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
12833 strict_overflow_p);
12835 /* MAX where operand 1 is positive is positive. */
12836 else if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
12837 &sub_strict_overflow_p)
12838 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
12839 &sub_strict_overflow_p))
12841 if (sub_strict_overflow_p)
12842 *strict_overflow_p = true;
12847 case COMPOUND_EXPR:
12850 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
12851 strict_overflow_p);
12854 case NON_LVALUE_EXPR:
12855 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
12856 strict_overflow_p);
12859 return (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
12861 || tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
12862 strict_overflow_p));
12865 return alloca_call_p (t);
12873 /* Return true when T is an address and is known to be nonzero.
12874 Handle warnings about undefined signed overflow. */
12877 tree_expr_nonzero_p (tree t)
12879 bool ret, strict_overflow_p;
12881 strict_overflow_p = false;
12882 ret = tree_expr_nonzero_warnv_p (t, &strict_overflow_p);
12883 if (strict_overflow_p)
12884 fold_overflow_warning (("assuming signed overflow does not occur when "
12885 "determining that expression is always "
12887 WARN_STRICT_OVERFLOW_MISC);
12891 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
12892 attempt to fold the expression to a constant without modifying TYPE,
12895 If the expression could be simplified to a constant, then return
12896 the constant. If the expression would not be simplified to a
12897 constant, then return NULL_TREE. */
12900 fold_binary_to_constant (enum tree_code code, tree type, tree op0, tree op1)
12902 tree tem = fold_binary (code, type, op0, op1);
12903 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
12906 /* Given the components of a unary expression CODE, TYPE and OP0,
12907 attempt to fold the expression to a constant without modifying
12910 If the expression could be simplified to a constant, then return
12911 the constant. If the expression would not be simplified to a
12912 constant, then return NULL_TREE. */
12915 fold_unary_to_constant (enum tree_code code, tree type, tree op0)
12917 tree tem = fold_unary (code, type, op0);
12918 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
12921 /* If EXP represents referencing an element in a constant string
12922 (either via pointer arithmetic or array indexing), return the
12923 tree representing the value accessed, otherwise return NULL. */
12926 fold_read_from_constant_string (tree exp)
12928 if ((TREE_CODE (exp) == INDIRECT_REF
12929 || TREE_CODE (exp) == ARRAY_REF)
12930 && TREE_CODE (TREE_TYPE (exp)) == INTEGER_TYPE)
12932 tree exp1 = TREE_OPERAND (exp, 0);
12936 if (TREE_CODE (exp) == INDIRECT_REF)
12937 string = string_constant (exp1, &index);
12940 tree low_bound = array_ref_low_bound (exp);
12941 index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
12943 /* Optimize the special-case of a zero lower bound.
12945 We convert the low_bound to sizetype to avoid some problems
12946 with constant folding. (E.g. suppose the lower bound is 1,
12947 and its mode is QI. Without the conversion,l (ARRAY
12948 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
12949 +INDEX), which becomes (ARRAY+255+INDEX). Opps!) */
12950 if (! integer_zerop (low_bound))
12951 index = size_diffop (index, fold_convert (sizetype, low_bound));
12957 && TYPE_MODE (TREE_TYPE (exp)) == TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))
12958 && TREE_CODE (string) == STRING_CST
12959 && TREE_CODE (index) == INTEGER_CST
12960 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
12961 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
12963 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
12964 return fold_convert (TREE_TYPE (exp),
12965 build_int_cst (NULL_TREE,
12966 (TREE_STRING_POINTER (string)
12967 [TREE_INT_CST_LOW (index)])));
12972 /* Return the tree for neg (ARG0) when ARG0 is known to be either
12973 an integer constant or real constant.
12975 TYPE is the type of the result. */
12978 fold_negate_const (tree arg0, tree type)
12980 tree t = NULL_TREE;
12982 switch (TREE_CODE (arg0))
12986 unsigned HOST_WIDE_INT low;
12987 HOST_WIDE_INT high;
12988 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
12989 TREE_INT_CST_HIGH (arg0),
12991 t = build_int_cst_wide (type, low, high);
12992 t = force_fit_type (t, 1,
12993 (overflow | TREE_OVERFLOW (arg0))
12994 && !TYPE_UNSIGNED (type),
12995 TREE_CONSTANT_OVERFLOW (arg0));
13000 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
13004 gcc_unreachable ();
13010 /* Return the tree for abs (ARG0) when ARG0 is known to be either
13011 an integer constant or real constant.
13013 TYPE is the type of the result. */
13016 fold_abs_const (tree arg0, tree type)
13018 tree t = NULL_TREE;
13020 switch (TREE_CODE (arg0))
13023 /* If the value is unsigned, then the absolute value is
13024 the same as the ordinary value. */
13025 if (TYPE_UNSIGNED (type))
13027 /* Similarly, if the value is non-negative. */
13028 else if (INT_CST_LT (integer_minus_one_node, arg0))
13030 /* If the value is negative, then the absolute value is
13034 unsigned HOST_WIDE_INT low;
13035 HOST_WIDE_INT high;
13036 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
13037 TREE_INT_CST_HIGH (arg0),
13039 t = build_int_cst_wide (type, low, high);
13040 t = force_fit_type (t, -1, overflow | TREE_OVERFLOW (arg0),
13041 TREE_CONSTANT_OVERFLOW (arg0));
13046 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
13047 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
13053 gcc_unreachable ();
13059 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
13060 constant. TYPE is the type of the result. */
13063 fold_not_const (tree arg0, tree type)
13065 tree t = NULL_TREE;
13067 gcc_assert (TREE_CODE (arg0) == INTEGER_CST);
13069 t = build_int_cst_wide (type,
13070 ~ TREE_INT_CST_LOW (arg0),
13071 ~ TREE_INT_CST_HIGH (arg0));
13072 t = force_fit_type (t, 0, TREE_OVERFLOW (arg0),
13073 TREE_CONSTANT_OVERFLOW (arg0));
13078 /* Given CODE, a relational operator, the target type, TYPE and two
13079 constant operands OP0 and OP1, return the result of the
13080 relational operation. If the result is not a compile time
13081 constant, then return NULL_TREE. */
13084 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
13086 int result, invert;
13088 /* From here on, the only cases we handle are when the result is
13089 known to be a constant. */
13091 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
13093 const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
13094 const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);
13096 /* Handle the cases where either operand is a NaN. */
13097 if (real_isnan (c0) || real_isnan (c1))
13107 case UNORDERED_EXPR:
13121 if (flag_trapping_math)
13127 gcc_unreachable ();
13130 return constant_boolean_node (result, type);
13133 return constant_boolean_node (real_compare (code, c0, c1), type);
13136 /* Handle equality/inequality of complex constants. */
13137 if (TREE_CODE (op0) == COMPLEX_CST && TREE_CODE (op1) == COMPLEX_CST)
13139 tree rcond = fold_relational_const (code, type,
13140 TREE_REALPART (op0),
13141 TREE_REALPART (op1));
13142 tree icond = fold_relational_const (code, type,
13143 TREE_IMAGPART (op0),
13144 TREE_IMAGPART (op1));
13145 if (code == EQ_EXPR)
13146 return fold_build2 (TRUTH_ANDIF_EXPR, type, rcond, icond);
13147 else if (code == NE_EXPR)
13148 return fold_build2 (TRUTH_ORIF_EXPR, type, rcond, icond);
13153 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
13155 To compute GT, swap the arguments and do LT.
13156 To compute GE, do LT and invert the result.
13157 To compute LE, swap the arguments, do LT and invert the result.
13158 To compute NE, do EQ and invert the result.
13160 Therefore, the code below must handle only EQ and LT. */
13162 if (code == LE_EXPR || code == GT_EXPR)
13167 code = swap_tree_comparison (code);
13170 /* Note that it is safe to invert for real values here because we
13171 have already handled the one case that it matters. */
13174 if (code == NE_EXPR || code == GE_EXPR)
13177 code = invert_tree_comparison (code, false);
13180 /* Compute a result for LT or EQ if args permit;
13181 Otherwise return T. */
13182 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
13184 if (code == EQ_EXPR)
13185 result = tree_int_cst_equal (op0, op1);
13186 else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
13187 result = INT_CST_LT_UNSIGNED (op0, op1);
13189 result = INT_CST_LT (op0, op1);
13196 return constant_boolean_node (result, type);
13199 /* Build an expression for the a clean point containing EXPR with type TYPE.
13200 Don't build a cleanup point expression for EXPR which don't have side
13204 fold_build_cleanup_point_expr (tree type, tree expr)
13206 /* If the expression does not have side effects then we don't have to wrap
13207 it with a cleanup point expression. */
13208 if (!TREE_SIDE_EFFECTS (expr))
13211 /* If the expression is a return, check to see if the expression inside the
13212 return has no side effects or the right hand side of the modify expression
13213 inside the return. If either don't have side effects set we don't need to
13214 wrap the expression in a cleanup point expression. Note we don't check the
13215 left hand side of the modify because it should always be a return decl. */
13216 if (TREE_CODE (expr) == RETURN_EXPR)
13218 tree op = TREE_OPERAND (expr, 0);
13219 if (!op || !TREE_SIDE_EFFECTS (op))
13221 op = TREE_OPERAND (op, 1);
13222 if (!TREE_SIDE_EFFECTS (op))
13226 return build1 (CLEANUP_POINT_EXPR, type, expr);
13229 /* Build an expression for the address of T. Folds away INDIRECT_REF to
13230 avoid confusing the gimplify process. */
13233 build_fold_addr_expr_with_type (tree t, tree ptrtype)
13235 /* The size of the object is not relevant when talking about its address. */
13236 if (TREE_CODE (t) == WITH_SIZE_EXPR)
13237 t = TREE_OPERAND (t, 0);
13239 /* Note: doesn't apply to ALIGN_INDIRECT_REF */
13240 if (TREE_CODE (t) == INDIRECT_REF
13241 || TREE_CODE (t) == MISALIGNED_INDIRECT_REF)
13243 t = TREE_OPERAND (t, 0);
13244 if (TREE_TYPE (t) != ptrtype)
13245 t = build1 (NOP_EXPR, ptrtype, t);
13251 while (handled_component_p (base))
13252 base = TREE_OPERAND (base, 0);
13254 TREE_ADDRESSABLE (base) = 1;
13256 t = build1 (ADDR_EXPR, ptrtype, t);
13263 build_fold_addr_expr (tree t)
13265 return build_fold_addr_expr_with_type (t, build_pointer_type (TREE_TYPE (t)));
13268 /* Given a pointer value OP0 and a type TYPE, return a simplified version
13269 of an indirection through OP0, or NULL_TREE if no simplification is
13273 fold_indirect_ref_1 (tree type, tree op0)
13279 subtype = TREE_TYPE (sub);
13280 if (!POINTER_TYPE_P (subtype))
13283 if (TREE_CODE (sub) == ADDR_EXPR)
13285 tree op = TREE_OPERAND (sub, 0);
13286 tree optype = TREE_TYPE (op);
13287 /* *&CONST_DECL -> to the value of the const decl. */
13288 if (TREE_CODE (op) == CONST_DECL)
13289 return DECL_INITIAL (op);
13290 /* *&p => p; make sure to handle *&"str"[cst] here. */
13291 if (type == optype)
13293 tree fop = fold_read_from_constant_string (op);
13299 /* *(foo *)&fooarray => fooarray[0] */
13300 else if (TREE_CODE (optype) == ARRAY_TYPE
13301 && type == TREE_TYPE (optype))
13303 tree type_domain = TYPE_DOMAIN (optype);
13304 tree min_val = size_zero_node;
13305 if (type_domain && TYPE_MIN_VALUE (type_domain))
13306 min_val = TYPE_MIN_VALUE (type_domain);
13307 return build4 (ARRAY_REF, type, op, min_val, NULL_TREE, NULL_TREE);
13309 /* *(foo *)&complexfoo => __real__ complexfoo */
13310 else if (TREE_CODE (optype) == COMPLEX_TYPE
13311 && type == TREE_TYPE (optype))
13312 return fold_build1 (REALPART_EXPR, type, op);
13315 /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */
13316 if (TREE_CODE (sub) == PLUS_EXPR
13317 && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
13319 tree op00 = TREE_OPERAND (sub, 0);
13320 tree op01 = TREE_OPERAND (sub, 1);
13324 op00type = TREE_TYPE (op00);
13325 if (TREE_CODE (op00) == ADDR_EXPR
13326 && TREE_CODE (TREE_TYPE (op00type)) == COMPLEX_TYPE
13327 && type == TREE_TYPE (TREE_TYPE (op00type)))
13329 tree size = TYPE_SIZE_UNIT (type);
13330 if (tree_int_cst_equal (size, op01))
13331 return fold_build1 (IMAGPART_EXPR, type, TREE_OPERAND (op00, 0));
13335 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
13336 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
13337 && type == TREE_TYPE (TREE_TYPE (subtype)))
13340 tree min_val = size_zero_node;
13341 sub = build_fold_indirect_ref (sub);
13342 type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
13343 if (type_domain && TYPE_MIN_VALUE (type_domain))
13344 min_val = TYPE_MIN_VALUE (type_domain);
13345 return build4 (ARRAY_REF, type, sub, min_val, NULL_TREE, NULL_TREE);
13351 /* Builds an expression for an indirection through T, simplifying some
13355 build_fold_indirect_ref (tree t)
13357 tree type = TREE_TYPE (TREE_TYPE (t));
13358 tree sub = fold_indirect_ref_1 (type, t);
13363 return build1 (INDIRECT_REF, type, t);
13366 /* Given an INDIRECT_REF T, return either T or a simplified version. */
13369 fold_indirect_ref (tree t)
13371 tree sub = fold_indirect_ref_1 (TREE_TYPE (t), TREE_OPERAND (t, 0));
13379 /* Strip non-trapping, non-side-effecting tree nodes from an expression
13380 whose result is ignored. The type of the returned tree need not be
13381 the same as the original expression. */
13384 fold_ignored_result (tree t)
13386 if (!TREE_SIDE_EFFECTS (t))
13387 return integer_zero_node;
13390 switch (TREE_CODE_CLASS (TREE_CODE (t)))
13393 t = TREE_OPERAND (t, 0);
13397 case tcc_comparison:
13398 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
13399 t = TREE_OPERAND (t, 0);
13400 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
13401 t = TREE_OPERAND (t, 1);
13406 case tcc_expression:
13407 switch (TREE_CODE (t))
13409 case COMPOUND_EXPR:
13410 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
13412 t = TREE_OPERAND (t, 0);
13416 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
13417 || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
13419 t = TREE_OPERAND (t, 0);
13432 /* Return the value of VALUE, rounded up to a multiple of DIVISOR.
13433 This can only be applied to objects of a sizetype. */
13436 round_up (tree value, int divisor)
13438 tree div = NULL_TREE;
13440 gcc_assert (divisor > 0);
13444 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
13445 have to do anything. Only do this when we are not given a const,
13446 because in that case, this check is more expensive than just
13448 if (TREE_CODE (value) != INTEGER_CST)
13450 div = build_int_cst (TREE_TYPE (value), divisor);
13452 if (multiple_of_p (TREE_TYPE (value), value, div))
13456 /* If divisor is a power of two, simplify this to bit manipulation. */
13457 if (divisor == (divisor & -divisor))
13461 t = build_int_cst (TREE_TYPE (value), divisor - 1);
13462 value = size_binop (PLUS_EXPR, value, t);
13463 t = build_int_cst (TREE_TYPE (value), -divisor);
13464 value = size_binop (BIT_AND_EXPR, value, t);
13469 div = build_int_cst (TREE_TYPE (value), divisor);
13470 value = size_binop (CEIL_DIV_EXPR, value, div);
13471 value = size_binop (MULT_EXPR, value, div);
13477 /* Likewise, but round down. */
13480 round_down (tree value, int divisor)
13482 tree div = NULL_TREE;
13484 gcc_assert (divisor > 0);
13488 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
13489 have to do anything. Only do this when we are not given a const,
13490 because in that case, this check is more expensive than just
13492 if (TREE_CODE (value) != INTEGER_CST)
13494 div = build_int_cst (TREE_TYPE (value), divisor);
13496 if (multiple_of_p (TREE_TYPE (value), value, div))
13500 /* If divisor is a power of two, simplify this to bit manipulation. */
13501 if (divisor == (divisor & -divisor))
13505 t = build_int_cst (TREE_TYPE (value), -divisor);
13506 value = size_binop (BIT_AND_EXPR, value, t);
13511 div = build_int_cst (TREE_TYPE (value), divisor);
13512 value = size_binop (FLOOR_DIV_EXPR, value, div);
13513 value = size_binop (MULT_EXPR, value, div);
13519 /* Returns the pointer to the base of the object addressed by EXP and
13520 extracts the information about the offset of the access, storing it
13521 to PBITPOS and POFFSET. */
13524 split_address_to_core_and_offset (tree exp,
13525 HOST_WIDE_INT *pbitpos, tree *poffset)
13528 enum machine_mode mode;
13529 int unsignedp, volatilep;
13530 HOST_WIDE_INT bitsize;
13532 if (TREE_CODE (exp) == ADDR_EXPR)
13534 core = get_inner_reference (TREE_OPERAND (exp, 0), &bitsize, pbitpos,
13535 poffset, &mode, &unsignedp, &volatilep,
13537 core = build_fold_addr_expr (core);
13543 *poffset = NULL_TREE;
13549 /* Returns true if addresses of E1 and E2 differ by a constant, false
13550 otherwise. If they do, E1 - E2 is stored in *DIFF. */
13553 ptr_difference_const (tree e1, tree e2, HOST_WIDE_INT *diff)
13556 HOST_WIDE_INT bitpos1, bitpos2;
13557 tree toffset1, toffset2, tdiff, type;
13559 core1 = split_address_to_core_and_offset (e1, &bitpos1, &toffset1);
13560 core2 = split_address_to_core_and_offset (e2, &bitpos2, &toffset2);
13562 if (bitpos1 % BITS_PER_UNIT != 0
13563 || bitpos2 % BITS_PER_UNIT != 0
13564 || !operand_equal_p (core1, core2, 0))
13567 if (toffset1 && toffset2)
13569 type = TREE_TYPE (toffset1);
13570 if (type != TREE_TYPE (toffset2))
13571 toffset2 = fold_convert (type, toffset2);
13573 tdiff = fold_build2 (MINUS_EXPR, type, toffset1, toffset2);
13574 if (!cst_and_fits_in_hwi (tdiff))
13577 *diff = int_cst_value (tdiff);
13579 else if (toffset1 || toffset2)
13581 /* If only one of the offsets is non-constant, the difference cannot
13588 *diff += (bitpos1 - bitpos2) / BITS_PER_UNIT;
13592 /* Simplify the floating point expression EXP when the sign of the
13593 result is not significant. Return NULL_TREE if no simplification
13597 fold_strip_sign_ops (tree exp)
13601 switch (TREE_CODE (exp))
13605 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
13606 return arg0 ? arg0 : TREE_OPERAND (exp, 0);
13610 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (exp))))
13612 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
13613 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
13614 if (arg0 != NULL_TREE || arg1 != NULL_TREE)
13615 return fold_build2 (TREE_CODE (exp), TREE_TYPE (exp),
13616 arg0 ? arg0 : TREE_OPERAND (exp, 0),
13617 arg1 ? arg1 : TREE_OPERAND (exp, 1));