1 /* If-conversion support.
2 Copyright (C) 2000, 2001 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GCC is distributed in the hope that it will be useful, but WITHOUT
12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
13 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
14 License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING. If not, write to the Free
18 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
28 #include "insn-config.h"
31 #include "hard-reg-set.h"
32 #include "basic-block.h"
40 #ifndef HAVE_conditional_execution
41 #define HAVE_conditional_execution 0
43 #ifndef HAVE_conditional_move
44 #define HAVE_conditional_move 0
55 #ifndef HAVE_conditional_trap
56 #define HAVE_conditional_trap 0
59 #ifndef MAX_CONDITIONAL_EXECUTE
60 #define MAX_CONDITIONAL_EXECUTE (BRANCH_COST + 1)
63 #define NULL_EDGE ((struct edge_def *)NULL)
64 #define NULL_BLOCK ((struct basic_block_def *)NULL)
66 /* # of IF-THEN or IF-THEN-ELSE blocks we looked at */
67 static int num_possible_if_blocks;
69 /* # of IF-THEN or IF-THEN-ELSE blocks were converted to conditional
71 static int num_updated_if_blocks;
73 /* # of basic blocks that were removed. */
74 static int num_removed_blocks;
76 /* True if life data ok at present. */
77 static bool life_data_ok;
79 /* The post-dominator relation on the original block numbers. */
80 static sbitmap *post_dominators;
82 /* Forward references. */
83 static int count_bb_insns PARAMS ((basic_block));
84 static rtx first_active_insn PARAMS ((basic_block));
85 static int last_active_insn_p PARAMS ((basic_block, rtx));
86 static int seq_contains_jump PARAMS ((rtx));
88 static int cond_exec_process_insns PARAMS ((rtx, rtx, rtx, rtx, int));
89 static rtx cond_exec_get_condition PARAMS ((rtx));
90 static int cond_exec_process_if_block PARAMS ((basic_block, basic_block,
91 basic_block, basic_block));
93 static rtx noce_get_condition PARAMS ((rtx, rtx *));
94 static int noce_operand_ok PARAMS ((rtx));
95 static int noce_process_if_block PARAMS ((basic_block, basic_block,
96 basic_block, basic_block));
98 static int process_if_block PARAMS ((basic_block, basic_block,
99 basic_block, basic_block));
100 static void merge_if_block PARAMS ((basic_block, basic_block,
101 basic_block, basic_block));
103 static int find_if_header PARAMS ((basic_block));
104 static int find_if_block PARAMS ((basic_block, edge, edge));
105 static int find_if_case_1 PARAMS ((basic_block, edge, edge));
106 static int find_if_case_2 PARAMS ((basic_block, edge, edge));
107 static int find_cond_trap PARAMS ((basic_block, edge, edge));
108 static rtx block_has_only_trap PARAMS ((basic_block));
109 static int find_memory PARAMS ((rtx *, void *));
110 static int dead_or_predicable PARAMS ((basic_block, basic_block,
111 basic_block, basic_block, int));
112 static void noce_emit_move_insn PARAMS ((rtx, rtx));
114 /* Abuse the basic_block AUX field to store the original block index,
115 as well as a flag indicating that the block should be rescaned for
118 #define SET_ORIG_INDEX(BB,I) ((BB)->aux = (void *)((size_t)(I) << 1))
119 #define ORIG_INDEX(BB) ((size_t)(BB)->aux >> 1)
120 #define SET_UPDATE_LIFE(BB) ((BB)->aux = (void *)((size_t)(BB)->aux | 1))
121 #define UPDATE_LIFE(BB) ((size_t)(BB)->aux & 1)
124 /* Count the number of non-jump active insns in BB. */
135 if (GET_CODE (insn) == CALL_INSN || GET_CODE (insn) == INSN)
140 insn = NEXT_INSN (insn);
146 /* Return the first non-jump active insn in the basic block. */
149 first_active_insn (bb)
154 if (GET_CODE (insn) == CODE_LABEL)
158 insn = NEXT_INSN (insn);
161 while (GET_CODE (insn) == NOTE)
165 insn = NEXT_INSN (insn);
168 if (GET_CODE (insn) == JUMP_INSN)
174 /* Return true if INSN is the last active non-jump insn in BB. */
177 last_active_insn_p (bb, insn)
185 insn = NEXT_INSN (insn);
187 while (GET_CODE (insn) == NOTE);
189 return GET_CODE (insn) == JUMP_INSN;
192 /* It is possible, especially when having dealt with multi-word
193 arithmetic, for the expanders to have emitted jumps. Search
194 through the sequence and return TRUE if a jump exists so that
195 we can abort the conversion. */
198 seq_contains_jump (insn)
203 if (GET_CODE (insn) == JUMP_INSN)
205 insn = NEXT_INSN (insn);
210 /* Go through a bunch of insns, converting them to conditional
211 execution format if possible. Return TRUE if all of the non-note
212 insns were processed. */
215 cond_exec_process_insns (start, end, test, prob_val, mod_ok)
216 rtx start; /* first insn to look at */
217 rtx end; /* last insn to look at */
218 rtx test; /* conditional execution test */
219 rtx prob_val; /* probability of branch taken. */
220 int mod_ok; /* true if modifications ok last insn. */
222 int must_be_last = FALSE;
226 for (insn = start; ; insn = NEXT_INSN (insn))
228 if (GET_CODE (insn) == NOTE)
231 if (GET_CODE (insn) != INSN && GET_CODE (insn) != CALL_INSN)
234 /* Remove USE insns that get in the way. */
235 if (reload_completed && GET_CODE (PATTERN (insn)) == USE)
237 /* ??? Ug. Actually unlinking the thing is problematic,
238 given what we'd have to coordinate with our callers. */
239 PUT_CODE (insn, NOTE);
240 NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
241 NOTE_SOURCE_FILE (insn) = 0;
245 /* Last insn wasn't last? */
249 if (modified_in_p (test, insn))
256 /* Now build the conditional form of the instruction. */
257 pattern = PATTERN (insn);
259 /* If the machine needs to modify the insn being conditionally executed,
260 say for example to force a constant integer operand into a temp
261 register, do so here. */
262 #ifdef IFCVT_MODIFY_INSN
263 IFCVT_MODIFY_INSN (pattern, insn);
268 validate_change (insn, &PATTERN (insn),
269 gen_rtx_COND_EXEC (VOIDmode, copy_rtx (test),
272 if (GET_CODE (insn) == CALL_INSN && prob_val)
273 validate_change (insn, ®_NOTES (insn),
274 alloc_EXPR_LIST (REG_BR_PROB, prob_val,
275 REG_NOTES (insn)), 1);
285 /* Return the condition for a jump. Do not do any special processing. */
288 cond_exec_get_condition (jump)
293 if (any_condjump_p (jump))
294 test_if = SET_SRC (pc_set (jump));
297 cond = XEXP (test_if, 0);
299 /* If this branches to JUMP_LABEL when the condition is false,
300 reverse the condition. */
301 if (GET_CODE (XEXP (test_if, 2)) == LABEL_REF
302 && XEXP (XEXP (test_if, 2), 0) == JUMP_LABEL (jump))
304 enum rtx_code rev = reversed_comparison_code (cond, jump);
308 cond = gen_rtx_fmt_ee (rev, GET_MODE (cond), XEXP (cond, 0),
315 /* Given a simple IF-THEN or IF-THEN-ELSE block, attempt to convert it
316 to conditional execution. Return TRUE if we were successful at
317 converting the the block. */
320 cond_exec_process_if_block (test_bb, then_bb, else_bb, join_bb)
321 basic_block test_bb; /* Basic block test is in */
322 basic_block then_bb; /* Basic block for THEN block */
323 basic_block else_bb; /* Basic block for ELSE block */
324 basic_block join_bb; /* Basic block the join label is in */
326 rtx test_expr; /* expression in IF_THEN_ELSE that is tested */
327 rtx then_start; /* first insn in THEN block */
328 rtx then_end; /* last insn + 1 in THEN block */
329 rtx else_start = NULL_RTX; /* first insn in ELSE block or NULL */
330 rtx else_end = NULL_RTX; /* last insn + 1 in ELSE block */
331 int max; /* max # of insns to convert. */
332 int then_mod_ok; /* whether conditional mods are ok in THEN */
333 rtx true_expr; /* test for else block insns */
334 rtx false_expr; /* test for then block insns */
335 rtx true_prob_val; /* probability of else block */
336 rtx false_prob_val; /* probability of then block */
338 enum rtx_code false_code;
340 /* Find the conditional jump to the ELSE or JOIN part, and isolate
342 test_expr = cond_exec_get_condition (test_bb->end);
346 /* If the conditional jump is more than just a conditional jump,
347 then we can not do conditional execution conversion on this block. */
348 if (!onlyjump_p (test_bb->end))
351 /* Collect the bounds of where we're to search. */
353 then_start = then_bb->head;
354 then_end = then_bb->end;
356 /* Skip a label heading THEN block. */
357 if (GET_CODE (then_start) == CODE_LABEL)
358 then_start = NEXT_INSN (then_start);
360 /* Skip a (use (const_int 0)) or branch as the final insn. */
361 if (GET_CODE (then_end) == INSN
362 && GET_CODE (PATTERN (then_end)) == USE
363 && GET_CODE (XEXP (PATTERN (then_end), 0)) == CONST_INT)
364 then_end = PREV_INSN (then_end);
365 else if (GET_CODE (then_end) == JUMP_INSN)
366 then_end = PREV_INSN (then_end);
370 /* Skip the ELSE block's label. */
371 else_start = NEXT_INSN (else_bb->head);
372 else_end = else_bb->end;
374 /* Skip a (use (const_int 0)) or branch as the final insn. */
375 if (GET_CODE (else_end) == INSN
376 && GET_CODE (PATTERN (else_end)) == USE
377 && GET_CODE (XEXP (PATTERN (else_end), 0)) == CONST_INT)
378 else_end = PREV_INSN (else_end);
379 else if (GET_CODE (else_end) == JUMP_INSN)
380 else_end = PREV_INSN (else_end);
383 /* How many instructions should we convert in total? */
387 max = 2 * MAX_CONDITIONAL_EXECUTE;
388 n_insns = count_bb_insns (else_bb);
391 max = MAX_CONDITIONAL_EXECUTE;
392 n_insns += count_bb_insns (then_bb);
396 /* Map test_expr/test_jump into the appropriate MD tests to use on
397 the conditionally executed code. */
399 true_expr = test_expr;
401 false_code = reversed_comparison_code (true_expr, test_bb->end);
402 if (false_code != UNKNOWN)
403 false_expr = gen_rtx_fmt_ee (false_code, GET_MODE (true_expr),
404 XEXP (true_expr, 0), XEXP (true_expr, 1));
406 false_expr = NULL_RTX;
408 #ifdef IFCVT_MODIFY_TESTS
409 /* If the machine description needs to modify the tests, such as setting a
410 conditional execution register from a comparison, it can do so here. */
411 IFCVT_MODIFY_TESTS (true_expr, false_expr, test_bb, then_bb, else_bb,
414 /* See if the conversion failed */
415 if (!true_expr || !false_expr)
419 true_prob_val = find_reg_note (test_bb->end, REG_BR_PROB, NULL_RTX);
422 true_prob_val = XEXP (true_prob_val, 0);
423 false_prob_val = GEN_INT (REG_BR_PROB_BASE - INTVAL (true_prob_val));
426 false_prob_val = NULL_RTX;
428 /* For IF-THEN-ELSE blocks, we don't allow modifications of the test
429 on then THEN block. */
430 then_mod_ok = (else_bb == NULL_BLOCK);
432 /* Go through the THEN and ELSE blocks converting the insns if possible
433 to conditional execution. */
437 || ! cond_exec_process_insns (then_start, then_end, false_expr,
438 false_prob_val, then_mod_ok)))
442 && ! cond_exec_process_insns (else_start, else_end,
443 true_expr, true_prob_val, TRUE))
446 if (! apply_change_group ())
449 #ifdef IFCVT_MODIFY_FINAL
450 /* Do any machine dependent final modifications */
451 IFCVT_MODIFY_FINAL (test_bb, then_bb, else_bb, join_bb);
454 /* Conversion succeeded. */
456 fprintf (rtl_dump_file, "%d insn%s converted to conditional execution.\n",
457 n_insns, (n_insns == 1) ? " was" : "s were");
459 /* Merge the blocks! */
460 merge_if_block (test_bb, then_bb, else_bb, join_bb);
464 #ifdef IFCVT_MODIFY_CANCEL
465 /* Cancel any machine dependent changes. */
466 IFCVT_MODIFY_CANCEL (test_bb, then_bb, else_bb, join_bb);
473 /* Used by noce_process_if_block to communicate with its subroutines.
475 The subroutines know that A and B may be evaluated freely. They
476 know that X is a register. They should insert new instructions
477 before cond_earliest. */
484 rtx jump, cond, cond_earliest;
487 static rtx noce_emit_store_flag PARAMS ((struct noce_if_info *,
489 static int noce_try_store_flag PARAMS ((struct noce_if_info *));
490 static int noce_try_store_flag_inc PARAMS ((struct noce_if_info *));
491 static int noce_try_store_flag_constants PARAMS ((struct noce_if_info *));
492 static int noce_try_store_flag_mask PARAMS ((struct noce_if_info *));
493 static rtx noce_emit_cmove PARAMS ((struct noce_if_info *,
494 rtx, enum rtx_code, rtx,
496 static int noce_try_cmove PARAMS ((struct noce_if_info *));
497 static int noce_try_cmove_arith PARAMS ((struct noce_if_info *));
498 static rtx noce_get_alt_condition PARAMS ((struct noce_if_info *,
500 static int noce_try_minmax PARAMS ((struct noce_if_info *));
501 static int noce_try_abs PARAMS ((struct noce_if_info *));
503 /* Helper function for noce_try_store_flag*. */
506 noce_emit_store_flag (if_info, x, reversep, normalize)
507 struct noce_if_info *if_info;
509 int reversep, normalize;
511 rtx cond = if_info->cond;
515 cond_complex = (! general_operand (XEXP (cond, 0), VOIDmode)
516 || ! general_operand (XEXP (cond, 1), VOIDmode));
518 /* If earliest == jump, or when the condition is complex, try to
519 build the store_flag insn directly. */
522 cond = XEXP (SET_SRC (pc_set (if_info->jump)), 0);
525 code = reversed_comparison_code (cond, if_info->jump);
527 code = GET_CODE (cond);
529 if ((if_info->cond_earliest == if_info->jump || cond_complex)
530 && (normalize == 0 || STORE_FLAG_VALUE == normalize))
534 tmp = gen_rtx_fmt_ee (code, GET_MODE (x), XEXP (cond, 0),
536 tmp = gen_rtx_SET (VOIDmode, x, tmp);
539 tmp = emit_insn (tmp);
541 if (recog_memoized (tmp) >= 0)
547 if_info->cond_earliest = if_info->jump;
555 /* Don't even try if the comparison operands are weird. */
559 return emit_store_flag (x, code, XEXP (cond, 0),
560 XEXP (cond, 1), VOIDmode,
561 (code == LTU || code == LEU
562 || code == GEU || code == GTU), normalize);
565 /* Emit instruction to move an rtx into STRICT_LOW_PART. */
567 noce_emit_move_insn (x, y)
570 enum machine_mode outmode, inmode;
574 if (GET_CODE (x) != STRICT_LOW_PART)
576 emit_move_insn (x, y);
581 inner = XEXP (outer, 0);
582 outmode = GET_MODE (outer);
583 inmode = GET_MODE (inner);
584 bitpos = SUBREG_BYTE (outer) * BITS_PER_UNIT;
585 store_bit_field (inner, GET_MODE_BITSIZE (outmode), bitpos, outmode, y,
586 GET_MODE_BITSIZE (inmode));
589 /* Convert "if (test) x = 1; else x = 0".
591 Only try 0 and STORE_FLAG_VALUE here. Other combinations will be
592 tried in noce_try_store_flag_constants after noce_try_cmove has had
593 a go at the conversion. */
596 noce_try_store_flag (if_info)
597 struct noce_if_info *if_info;
602 if (GET_CODE (if_info->b) == CONST_INT
603 && INTVAL (if_info->b) == STORE_FLAG_VALUE
604 && if_info->a == const0_rtx)
606 else if (if_info->b == const0_rtx
607 && GET_CODE (if_info->a) == CONST_INT
608 && INTVAL (if_info->a) == STORE_FLAG_VALUE
609 && (reversed_comparison_code (if_info->cond, if_info->jump)
617 target = noce_emit_store_flag (if_info, if_info->x, reversep, 0);
620 if (target != if_info->x)
621 noce_emit_move_insn (if_info->x, target);
625 emit_insns_before (seq, if_info->jump);
636 /* Convert "if (test) x = a; else x = b", for A and B constant. */
639 noce_try_store_flag_constants (if_info)
640 struct noce_if_info *if_info;
644 HOST_WIDE_INT itrue, ifalse, diff, tmp;
645 int normalize, can_reverse;
646 enum machine_mode mode;
649 && GET_CODE (if_info->a) == CONST_INT
650 && GET_CODE (if_info->b) == CONST_INT)
652 mode = GET_MODE (if_info->x);
653 ifalse = INTVAL (if_info->a);
654 itrue = INTVAL (if_info->b);
656 /* Make sure we can represent the difference between the two values. */
657 if ((itrue - ifalse > 0)
658 != ((ifalse < 0) != (itrue < 0) ? ifalse < 0 : ifalse < itrue))
661 diff = trunc_int_for_mode (itrue - ifalse, mode);
663 can_reverse = (reversed_comparison_code (if_info->cond, if_info->jump)
667 if (diff == STORE_FLAG_VALUE || diff == -STORE_FLAG_VALUE)
669 else if (ifalse == 0 && exact_log2 (itrue) >= 0
670 && (STORE_FLAG_VALUE == 1
671 || BRANCH_COST >= 2))
673 else if (itrue == 0 && exact_log2 (ifalse) >= 0 && can_reverse
674 && (STORE_FLAG_VALUE == 1 || BRANCH_COST >= 2))
675 normalize = 1, reversep = 1;
677 && (STORE_FLAG_VALUE == -1
678 || BRANCH_COST >= 2))
680 else if (ifalse == -1 && can_reverse
681 && (STORE_FLAG_VALUE == -1 || BRANCH_COST >= 2))
682 normalize = -1, reversep = 1;
683 else if ((BRANCH_COST >= 2 && STORE_FLAG_VALUE == -1)
691 tmp = itrue; itrue = ifalse; ifalse = tmp;
692 diff = trunc_int_for_mode (-diff, mode);
696 target = noce_emit_store_flag (if_info, if_info->x, reversep, normalize);
703 /* if (test) x = 3; else x = 4;
704 => x = 3 + (test == 0); */
705 if (diff == STORE_FLAG_VALUE || diff == -STORE_FLAG_VALUE)
707 target = expand_simple_binop (mode,
708 (diff == STORE_FLAG_VALUE
710 GEN_INT (ifalse), target, if_info->x, 0,
714 /* if (test) x = 8; else x = 0;
715 => x = (test != 0) << 3; */
716 else if (ifalse == 0 && (tmp = exact_log2 (itrue)) >= 0)
718 target = expand_simple_binop (mode, ASHIFT,
719 target, GEN_INT (tmp), if_info->x, 0,
723 /* if (test) x = -1; else x = b;
724 => x = -(test != 0) | b; */
725 else if (itrue == -1)
727 target = expand_simple_binop (mode, IOR,
728 target, GEN_INT (ifalse), if_info->x, 0,
732 /* if (test) x = a; else x = b;
733 => x = (-(test != 0) & (b - a)) + a; */
736 target = expand_simple_binop (mode, AND,
737 target, GEN_INT (diff), if_info->x, 0,
740 target = expand_simple_binop (mode, PLUS,
741 target, GEN_INT (ifalse),
742 if_info->x, 0, OPTAB_WIDEN);
751 if (target != if_info->x)
752 noce_emit_move_insn (if_info->x, target);
757 if (seq_contains_jump (seq))
760 emit_insns_before (seq, if_info->jump);
768 /* Convert "if (test) foo++" into "foo += (test != 0)", and
769 similarly for "foo--". */
772 noce_try_store_flag_inc (if_info)
773 struct noce_if_info *if_info;
776 int subtract, normalize;
782 /* Should be no `else' case to worry about. */
783 && if_info->b == if_info->x
784 && GET_CODE (if_info->a) == PLUS
785 && (XEXP (if_info->a, 1) == const1_rtx
786 || XEXP (if_info->a, 1) == constm1_rtx)
787 && rtx_equal_p (XEXP (if_info->a, 0), if_info->x)
788 && (reversed_comparison_code (if_info->cond, if_info->jump)
791 if (STORE_FLAG_VALUE == INTVAL (XEXP (if_info->a, 1)))
792 subtract = 0, normalize = 0;
793 else if (-STORE_FLAG_VALUE == INTVAL (XEXP (if_info->a, 1)))
794 subtract = 1, normalize = 0;
796 subtract = 0, normalize = INTVAL (XEXP (if_info->a, 1));
800 target = noce_emit_store_flag (if_info,
801 gen_reg_rtx (GET_MODE (if_info->x)),
805 target = expand_simple_binop (GET_MODE (if_info->x),
806 subtract ? MINUS : PLUS,
807 if_info->x, target, if_info->x,
811 if (target != if_info->x)
812 noce_emit_move_insn (if_info->x, target);
817 if (seq_contains_jump (seq))
820 emit_insns_before (seq, if_info->jump);
831 /* Convert "if (test) x = 0;" to "x &= -(test == 0);" */
834 noce_try_store_flag_mask (if_info)
835 struct noce_if_info *if_info;
843 || STORE_FLAG_VALUE == -1)
844 && ((if_info->a == const0_rtx
845 && rtx_equal_p (if_info->b, if_info->x))
846 || ((reversep = (reversed_comparison_code (if_info->cond,
849 && if_info->b == const0_rtx
850 && rtx_equal_p (if_info->a, if_info->x))))
853 target = noce_emit_store_flag (if_info,
854 gen_reg_rtx (GET_MODE (if_info->x)),
857 target = expand_simple_binop (GET_MODE (if_info->x), AND,
858 if_info->x, target, if_info->x, 0,
863 if (target != if_info->x)
864 noce_emit_move_insn (if_info->x, target);
869 if (seq_contains_jump (seq))
872 emit_insns_before (seq, if_info->jump);
883 /* Helper function for noce_try_cmove and noce_try_cmove_arith. */
886 noce_emit_cmove (if_info, x, code, cmp_a, cmp_b, vfalse, vtrue)
887 struct noce_if_info *if_info;
888 rtx x, cmp_a, cmp_b, vfalse, vtrue;
891 /* If earliest == jump, try to build the cmove insn directly.
892 This is helpful when combine has created some complex condition
893 (like for alpha's cmovlbs) that we can't hope to regenerate
894 through the normal interface. */
896 if (if_info->cond_earliest == if_info->jump)
900 tmp = gen_rtx_fmt_ee (code, GET_MODE (if_info->cond), cmp_a, cmp_b);
901 tmp = gen_rtx_IF_THEN_ELSE (GET_MODE (x), tmp, vtrue, vfalse);
902 tmp = gen_rtx_SET (VOIDmode, x, tmp);
905 tmp = emit_insn (tmp);
907 if (recog_memoized (tmp) >= 0)
919 /* Don't even try if the comparison operands are weird. */
920 if (! general_operand (cmp_a, GET_MODE (cmp_a))
921 || ! general_operand (cmp_b, GET_MODE (cmp_b)))
924 #if HAVE_conditional_move
925 return emit_conditional_move (x, code, cmp_a, cmp_b, VOIDmode,
926 vtrue, vfalse, GET_MODE (x),
927 (code == LTU || code == GEU
928 || code == LEU || code == GTU));
930 /* We'll never get here, as noce_process_if_block doesn't call the
931 functions involved. Ifdef code, however, should be discouraged
932 because it leads to typos in the code not selected. However,
933 emit_conditional_move won't exist either. */
938 /* Try only simple constants and registers here. More complex cases
939 are handled in noce_try_cmove_arith after noce_try_store_flag_arith
940 has had a go at it. */
943 noce_try_cmove (if_info)
944 struct noce_if_info *if_info;
949 if ((CONSTANT_P (if_info->a) || register_operand (if_info->a, VOIDmode))
950 && (CONSTANT_P (if_info->b) || register_operand (if_info->b, VOIDmode)))
954 code = GET_CODE (if_info->cond);
955 target = noce_emit_cmove (if_info, if_info->x, code,
956 XEXP (if_info->cond, 0),
957 XEXP (if_info->cond, 1),
958 if_info->a, if_info->b);
962 if (target != if_info->x)
963 noce_emit_move_insn (if_info->x, target);
967 emit_insns_before (seq, if_info->jump);
980 /* Try more complex cases involving conditional_move. */
983 noce_try_cmove_arith (if_info)
984 struct noce_if_info *if_info;
994 /* A conditional move from two memory sources is equivalent to a
995 conditional on their addresses followed by a load. Don't do this
996 early because it'll screw alias analysis. Note that we've
997 already checked for no side effects. */
998 if (! no_new_pseudos && cse_not_expected
999 && GET_CODE (a) == MEM && GET_CODE (b) == MEM
1000 && BRANCH_COST >= 5)
1004 x = gen_reg_rtx (Pmode);
1008 /* ??? We could handle this if we knew that a load from A or B could
1009 not fault. This is also true if we've already loaded
1010 from the address along the path from ENTRY. */
1011 else if (may_trap_p (a) || may_trap_p (b))
1014 /* if (test) x = a + b; else x = c - d;
1021 code = GET_CODE (if_info->cond);
1022 insn_a = if_info->insn_a;
1023 insn_b = if_info->insn_b;
1025 /* Possibly rearrange operands to make things come out more natural. */
1026 if (reversed_comparison_code (if_info->cond, if_info->jump) != UNKNOWN)
1029 if (rtx_equal_p (b, x))
1031 else if (general_operand (b, GET_MODE (b)))
1036 code = reversed_comparison_code (if_info->cond, if_info->jump);
1037 tmp = a, a = b, b = tmp;
1038 tmp = insn_a, insn_a = insn_b, insn_b = tmp;
1044 /* If either operand is complex, load it into a register first.
1045 The best way to do this is to copy the original insn. In this
1046 way we preserve any clobbers etc that the insn may have had.
1047 This is of course not possible in the IS_MEM case. */
1048 if (! general_operand (a, GET_MODE (a)))
1053 goto end_seq_and_fail;
1057 tmp = gen_reg_rtx (GET_MODE (a));
1058 tmp = emit_insn (gen_rtx_SET (VOIDmode, tmp, a));
1061 goto end_seq_and_fail;
1064 a = gen_reg_rtx (GET_MODE (a));
1065 tmp = copy_rtx (insn_a);
1066 set = single_set (tmp);
1068 tmp = emit_insn (PATTERN (tmp));
1070 if (recog_memoized (tmp) < 0)
1071 goto end_seq_and_fail;
1073 if (! general_operand (b, GET_MODE (b)))
1078 goto end_seq_and_fail;
1082 tmp = gen_reg_rtx (GET_MODE (b));
1083 tmp = emit_insn (gen_rtx_SET (VOIDmode, tmp, b));
1086 goto end_seq_and_fail;
1089 b = gen_reg_rtx (GET_MODE (b));
1090 tmp = copy_rtx (insn_b);
1091 set = single_set (tmp);
1093 tmp = emit_insn (PATTERN (tmp));
1095 if (recog_memoized (tmp) < 0)
1096 goto end_seq_and_fail;
1099 target = noce_emit_cmove (if_info, x, code, XEXP (if_info->cond, 0),
1100 XEXP (if_info->cond, 1), a, b);
1103 goto end_seq_and_fail;
1105 /* If we're handling a memory for above, emit the load now. */
1108 tmp = gen_rtx_MEM (GET_MODE (if_info->x), target);
1110 /* Copy over flags as appropriate. */
1111 if (MEM_VOLATILE_P (if_info->a) || MEM_VOLATILE_P (if_info->b))
1112 MEM_VOLATILE_P (tmp) = 1;
1113 if (MEM_IN_STRUCT_P (if_info->a) && MEM_IN_STRUCT_P (if_info->b))
1114 MEM_IN_STRUCT_P (tmp) = 1;
1115 if (MEM_SCALAR_P (if_info->a) && MEM_SCALAR_P (if_info->b))
1116 MEM_SCALAR_P (tmp) = 1;
1117 if (MEM_ALIAS_SET (if_info->a) == MEM_ALIAS_SET (if_info->b))
1118 set_mem_alias_set (tmp, MEM_ALIAS_SET (if_info->a));
1120 MIN (MEM_ALIGN (if_info->a), MEM_ALIGN (if_info->b)));
1122 noce_emit_move_insn (if_info->x, tmp);
1124 else if (target != x)
1125 noce_emit_move_insn (x, target);
1129 emit_insns_before (tmp, if_info->jump);
1137 /* For most cases, the simplified condition we found is the best
1138 choice, but this is not the case for the min/max/abs transforms.
1139 For these we wish to know that it is A or B in the condition. */
1142 noce_get_alt_condition (if_info, target, earliest)
1143 struct noce_if_info *if_info;
1147 rtx cond, set, insn;
1150 /* If target is already mentioned in the known condition, return it. */
1151 if (reg_mentioned_p (target, if_info->cond))
1153 *earliest = if_info->cond_earliest;
1154 return if_info->cond;
1157 set = pc_set (if_info->jump);
1158 cond = XEXP (SET_SRC (set), 0);
1160 = GET_CODE (XEXP (SET_SRC (set), 2)) == LABEL_REF
1161 && XEXP (XEXP (SET_SRC (set), 2), 0) == JUMP_LABEL (if_info->jump);
1163 /* If we're looking for a constant, try to make the conditional
1164 have that constant in it. There are two reasons why it may
1165 not have the constant we want:
1167 1. GCC may have needed to put the constant in a register, because
1168 the target can't compare directly against that constant. For
1169 this case, we look for a SET immediately before the comparison
1170 that puts a constant in that register.
1172 2. GCC may have canonicalized the conditional, for example
1173 replacing "if x < 4" with "if x <= 3". We can undo that (or
1174 make equivalent types of changes) to get the constants we need
1175 if they're off by one in the right direction. */
1177 if (GET_CODE (target) == CONST_INT)
1179 enum rtx_code code = GET_CODE (if_info->cond);
1180 rtx op_a = XEXP (if_info->cond, 0);
1181 rtx op_b = XEXP (if_info->cond, 1);
1184 /* First, look to see if we put a constant in a register. */
1185 prev_insn = PREV_INSN (if_info->cond_earliest);
1187 && INSN_P (prev_insn)
1188 && GET_CODE (PATTERN (prev_insn)) == SET)
1190 rtx src = find_reg_equal_equiv_note (prev_insn);
1192 src = SET_SRC (PATTERN (prev_insn));
1193 if (GET_CODE (src) == CONST_INT)
1195 if (rtx_equal_p (op_a, SET_DEST (PATTERN (prev_insn))))
1197 else if (rtx_equal_p (op_b, SET_DEST (PATTERN (prev_insn))))
1200 if (GET_CODE (op_a) == CONST_INT)
1205 code = swap_condition (code);
1210 /* Now, look to see if we can get the right constant by
1211 adjusting the conditional. */
1212 if (GET_CODE (op_b) == CONST_INT)
1214 HOST_WIDE_INT desired_val = INTVAL (target);
1215 HOST_WIDE_INT actual_val = INTVAL (op_b);
1220 if (actual_val == desired_val + 1)
1223 op_b = GEN_INT (desired_val);
1227 if (actual_val == desired_val - 1)
1230 op_b = GEN_INT (desired_val);
1234 if (actual_val == desired_val - 1)
1237 op_b = GEN_INT (desired_val);
1241 if (actual_val == desired_val + 1)
1244 op_b = GEN_INT (desired_val);
1252 /* If we made any changes, generate a new conditional that is
1253 equivalent to what we started with, but has the right
1255 if (code != GET_CODE (if_info->cond)
1256 || op_a != XEXP (if_info->cond, 0)
1257 || op_b != XEXP (if_info->cond, 1))
1259 cond = gen_rtx_fmt_ee (code, GET_MODE (cond), op_a, op_b);
1260 *earliest = if_info->cond_earliest;
1265 cond = canonicalize_condition (if_info->jump, cond, reverse,
1267 if (! cond || ! reg_mentioned_p (target, cond))
1270 /* We almost certainly searched back to a different place.
1271 Need to re-verify correct lifetimes. */
1273 /* X may not be mentioned in the range (cond_earliest, jump]. */
1274 for (insn = if_info->jump; insn != *earliest; insn = PREV_INSN (insn))
1275 if (INSN_P (insn) && reg_mentioned_p (if_info->x, insn))
1278 /* A and B may not be modified in the range [cond_earliest, jump). */
1279 for (insn = *earliest; insn != if_info->jump; insn = NEXT_INSN (insn))
1281 && (modified_in_p (if_info->a, insn)
1282 || modified_in_p (if_info->b, insn)))
1288 /* Convert "if (a < b) x = a; else x = b;" to "x = min(a, b);", etc. */
1291 noce_try_minmax (if_info)
1292 struct noce_if_info *if_info;
1294 rtx cond, earliest, target, seq;
1295 enum rtx_code code, op;
1298 /* ??? Can't guarantee that expand_binop won't create pseudos. */
1302 /* ??? Reject FP modes since we don't know how 0 vs -0 or NaNs
1303 will be resolved with an SMIN/SMAX. It wouldn't be too hard
1304 to get the target to tell us... */
1305 if (FLOAT_MODE_P (GET_MODE (if_info->x))
1306 && TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
1307 && ! flag_unsafe_math_optimizations)
1310 cond = noce_get_alt_condition (if_info, if_info->a, &earliest);
1314 /* Verify the condition is of the form we expect, and canonicalize
1315 the comparison code. */
1316 code = GET_CODE (cond);
1317 if (rtx_equal_p (XEXP (cond, 0), if_info->a))
1319 if (! rtx_equal_p (XEXP (cond, 1), if_info->b))
1322 else if (rtx_equal_p (XEXP (cond, 1), if_info->a))
1324 if (! rtx_equal_p (XEXP (cond, 0), if_info->b))
1326 code = swap_condition (code);
1331 /* Determine what sort of operation this is. Note that the code is for
1332 a taken branch, so the code->operation mapping appears backwards. */
1365 target = expand_simple_binop (GET_MODE (if_info->x), op,
1366 if_info->a, if_info->b,
1367 if_info->x, unsignedp, OPTAB_WIDEN);
1373 if (target != if_info->x)
1374 noce_emit_move_insn (if_info->x, target);
1379 if (seq_contains_jump (seq))
1382 emit_insns_before (seq, if_info->jump);
1383 if_info->cond = cond;
1384 if_info->cond_earliest = earliest;
1389 /* Convert "if (a < 0) x = -a; else x = a;" to "x = abs(a);", etc. */
1392 noce_try_abs (if_info)
1393 struct noce_if_info *if_info;
1395 rtx cond, earliest, target, seq, a, b, c;
1398 /* ??? Can't guarantee that expand_binop won't create pseudos. */
1402 /* Recognize A and B as constituting an ABS or NABS. */
1405 if (GET_CODE (a) == NEG && rtx_equal_p (XEXP (a, 0), b))
1407 else if (GET_CODE (b) == NEG && rtx_equal_p (XEXP (b, 0), a))
1409 c = a; a = b; b = c;
1415 cond = noce_get_alt_condition (if_info, b, &earliest);
1419 /* Verify the condition is of the form we expect. */
1420 if (rtx_equal_p (XEXP (cond, 0), b))
1422 else if (rtx_equal_p (XEXP (cond, 1), b))
1427 /* Verify that C is zero. Search backward through the block for
1428 a REG_EQUAL note if necessary. */
1431 rtx insn, note = NULL;
1432 for (insn = earliest;
1433 insn != if_info->test_bb->head;
1434 insn = PREV_INSN (insn))
1436 && ((note = find_reg_note (insn, REG_EQUAL, c))
1437 || (note = find_reg_note (insn, REG_EQUIV, c))))
1443 if (GET_CODE (c) == MEM
1444 && GET_CODE (XEXP (c, 0)) == SYMBOL_REF
1445 && CONSTANT_POOL_ADDRESS_P (XEXP (c, 0)))
1446 c = get_pool_constant (XEXP (c, 0));
1448 /* Work around funny ideas get_condition has wrt canonicalization.
1449 Note that these rtx constants are known to be CONST_INT, and
1450 therefore imply integer comparisons. */
1451 if (c == constm1_rtx && GET_CODE (cond) == GT)
1453 else if (c == const1_rtx && GET_CODE (cond) == LT)
1455 else if (c != CONST0_RTX (GET_MODE (b)))
1458 /* Determine what sort of operation this is. */
1459 switch (GET_CODE (cond))
1478 target = expand_simple_unop (GET_MODE (if_info->x), ABS, b, if_info->x, 0);
1480 /* ??? It's a quandry whether cmove would be better here, especially
1481 for integers. Perhaps combine will clean things up. */
1482 if (target && negate)
1483 target = expand_simple_unop (GET_MODE (target), NEG, target, if_info->x, 0);
1491 if (target != if_info->x)
1492 noce_emit_move_insn (if_info->x, target);
1497 if (seq_contains_jump (seq))
1500 emit_insns_before (seq, if_info->jump);
1501 if_info->cond = cond;
1502 if_info->cond_earliest = earliest;
1507 /* Look for the condition for the jump first. We'd prefer to avoid
1508 get_condition if we can -- it tries to look back for the contents
1509 of an original compare. On targets that use normal integers for
1510 comparisons, e.g. alpha, this is wasteful. */
1513 noce_get_condition (jump, earliest)
1520 /* If the condition variable is a register and is MODE_INT, accept it.
1521 Otherwise, fall back on get_condition. */
1523 if (! any_condjump_p (jump))
1526 set = pc_set (jump);
1528 cond = XEXP (SET_SRC (set), 0);
1529 if (GET_CODE (XEXP (cond, 0)) == REG
1530 && GET_MODE_CLASS (GET_MODE (XEXP (cond, 0))) == MODE_INT)
1534 /* If this branches to JUMP_LABEL when the condition is false,
1535 reverse the condition. */
1536 if (GET_CODE (XEXP (SET_SRC (set), 2)) == LABEL_REF
1537 && XEXP (XEXP (SET_SRC (set), 2), 0) == JUMP_LABEL (jump))
1538 cond = gen_rtx_fmt_ee (reverse_condition (GET_CODE (cond)),
1539 GET_MODE (cond), XEXP (cond, 0),
1543 cond = get_condition (jump, earliest);
1548 /* Return true if OP is ok for if-then-else processing. */
1551 noce_operand_ok (op)
1554 /* We special-case memories, so handle any of them with
1555 no address side effects. */
1556 if (GET_CODE (op) == MEM)
1557 return ! side_effects_p (XEXP (op, 0));
1559 if (side_effects_p (op))
1562 /* ??? Unfortuantely may_trap_p can't look at flag_trapping_math, due to
1563 being linked into the genfoo programs. This is probably a mistake.
1564 With finite operands, most fp operations don't trap. */
1565 if (!flag_trapping_math && FLOAT_MODE_P (GET_MODE (op)))
1566 switch (GET_CODE (op))
1572 /* ??? This is kinda lame -- almost every target will have forced
1573 the constant into a register first. But given the expense of
1574 division, this is probably for the best. */
1575 return (CONSTANT_P (XEXP (op, 1))
1576 && XEXP (op, 1) != CONST0_RTX (GET_MODE (op))
1577 && ! may_trap_p (XEXP (op, 0)));
1580 switch (GET_RTX_CLASS (GET_CODE (op)))
1583 return ! may_trap_p (XEXP (op, 0));
1586 return ! may_trap_p (XEXP (op, 0)) && ! may_trap_p (XEXP (op, 1));
1591 return ! may_trap_p (op);
1594 /* Given a simple IF-THEN or IF-THEN-ELSE block, attempt to convert it
1595 without using conditional execution. Return TRUE if we were
1596 successful at converting the the block. */
1599 noce_process_if_block (test_bb, then_bb, else_bb, join_bb)
1600 basic_block test_bb; /* Basic block test is in */
1601 basic_block then_bb; /* Basic block for THEN block */
1602 basic_block else_bb; /* Basic block for ELSE block */
1603 basic_block join_bb; /* Basic block the join label is in */
1605 /* We're looking for patterns of the form
1607 (1) if (...) x = a; else x = b;
1608 (2) x = b; if (...) x = a;
1609 (3) if (...) x = a; // as if with an initial x = x.
1611 The later patterns require jumps to be more expensive.
1613 ??? For future expansion, look for multiple X in such patterns. */
1615 struct noce_if_info if_info;
1618 rtx orig_x, x, a, b;
1619 rtx jump, cond, insn;
1621 /* If this is not a standard conditional jump, we can't parse it. */
1622 jump = test_bb->end;
1623 cond = noce_get_condition (jump, &if_info.cond_earliest);
1627 /* If the conditional jump is more than just a conditional jump,
1628 then we can not do if-conversion on this block. */
1629 if (! onlyjump_p (jump))
1632 /* We must be comparing objects whose modes imply the size. */
1633 if (GET_MODE (XEXP (cond, 0)) == BLKmode)
1636 /* Look for one of the potential sets. */
1637 insn_a = first_active_insn (then_bb);
1639 || ! last_active_insn_p (then_bb, insn_a)
1640 || (set_a = single_set (insn_a)) == NULL_RTX)
1643 x = SET_DEST (set_a);
1644 a = SET_SRC (set_a);
1646 /* Look for the other potential set. Make sure we've got equivalent
1648 /* ??? This is overconservative. Storing to two different mems is
1649 as easy as conditionally computing the address. Storing to a
1650 single mem merely requires a scratch memory to use as one of the
1651 destination addresses; often the memory immediately below the
1652 stack pointer is available for this. */
1656 insn_b = first_active_insn (else_bb);
1658 || ! last_active_insn_p (else_bb, insn_b)
1659 || (set_b = single_set (insn_b)) == NULL_RTX
1660 || ! rtx_equal_p (x, SET_DEST (set_b)))
1665 insn_b = prev_nonnote_insn (if_info.cond_earliest);
1667 || GET_CODE (insn_b) != INSN
1668 || (set_b = single_set (insn_b)) == NULL_RTX
1669 || ! rtx_equal_p (x, SET_DEST (set_b))
1670 || reg_mentioned_p (x, cond)
1671 || reg_mentioned_p (x, a)
1672 || reg_mentioned_p (x, SET_SRC (set_b)))
1673 insn_b = set_b = NULL_RTX;
1675 b = (set_b ? SET_SRC (set_b) : x);
1677 /* X may not be mentioned in the range (cond_earliest, jump]. */
1678 for (insn = jump; insn != if_info.cond_earliest; insn = PREV_INSN (insn))
1679 if (INSN_P (insn) && reg_mentioned_p (x, insn))
1682 /* A and B may not be modified in the range [cond_earliest, jump). */
1683 for (insn = if_info.cond_earliest; insn != jump; insn = NEXT_INSN (insn))
1685 && (modified_in_p (a, insn) || modified_in_p (b, insn)))
1688 /* Only operate on register destinations, and even then avoid extending
1689 the lifetime of hard registers on small register class machines. */
1691 if (GET_CODE (x) != REG
1692 || (SMALL_REGISTER_CLASSES
1693 && REGNO (x) < FIRST_PSEUDO_REGISTER))
1697 x = gen_reg_rtx (GET_MODE (GET_CODE (x) == STRICT_LOW_PART
1698 ? XEXP (x, 0) : x));
1701 /* Don't operate on sources that may trap or are volatile. */
1702 if (! noce_operand_ok (a) || ! noce_operand_ok (b))
1705 /* Set up the info block for our subroutines. */
1706 if_info.test_bb = test_bb;
1707 if_info.cond = cond;
1708 if_info.jump = jump;
1709 if_info.insn_a = insn_a;
1710 if_info.insn_b = insn_b;
1715 /* Try optimizations in some approximation of a useful order. */
1716 /* ??? Should first look to see if X is live incoming at all. If it
1717 isn't, we don't need anything but an unconditional set. */
1719 /* Look and see if A and B are really the same. Avoid creating silly
1720 cmove constructs that no one will fix up later. */
1721 if (rtx_equal_p (a, b))
1723 /* If we have an INSN_B, we don't have to create any new rtl. Just
1724 move the instruction that we already have. If we don't have an
1725 INSN_B, that means that A == X, and we've got a noop move. In
1726 that case don't do anything and let the code below delete INSN_A. */
1727 if (insn_b && else_bb)
1731 if (else_bb && insn_b == else_bb->end)
1732 else_bb->end = PREV_INSN (insn_b);
1733 reorder_insns (insn_b, insn_b, PREV_INSN (if_info.cond_earliest));
1735 /* If there was a REG_EQUAL note, delete it since it may have been
1736 true due to this insn being after a jump. */
1737 if ((note = find_reg_note (insn_b, REG_EQUAL, NULL_RTX)) != 0)
1738 remove_note (insn_b, note);
1742 /* If we have "x = b; if (...) x = a;", and x has side-effects, then
1743 x must be executed twice. */
1744 else if (insn_b && side_effects_p (orig_x))
1751 if (noce_try_store_flag (&if_info))
1753 if (noce_try_minmax (&if_info))
1755 if (noce_try_abs (&if_info))
1757 if (HAVE_conditional_move
1758 && noce_try_cmove (&if_info))
1760 if (! HAVE_conditional_execution)
1762 if (noce_try_store_flag_constants (&if_info))
1764 if (noce_try_store_flag_inc (&if_info))
1766 if (noce_try_store_flag_mask (&if_info))
1768 if (HAVE_conditional_move
1769 && noce_try_cmove_arith (&if_info))
1776 /* The original sets may now be killed. */
1777 delete_insn (insn_a);
1779 /* Several special cases here: First, we may have reused insn_b above,
1780 in which case insn_b is now NULL. Second, we want to delete insn_b
1781 if it came from the ELSE block, because follows the now correct
1782 write that appears in the TEST block. However, if we got insn_b from
1783 the TEST block, it may in fact be loading data needed for the comparison.
1784 We'll let life_analysis remove the insn if it's really dead. */
1785 if (insn_b && else_bb)
1786 delete_insn (insn_b);
1788 /* The new insns will have been inserted just before the jump. We should
1789 be able to remove the jump with impunity, but the condition itself may
1790 have been modified by gcse to be shared across basic blocks. */
1793 /* If we used a temporary, fix it up now. */
1797 noce_emit_move_insn (copy_rtx (orig_x), x);
1798 insn_b = gen_sequence ();
1801 emit_insn_after (insn_b, test_bb->end);
1804 /* Merge the blocks! */
1805 merge_if_block (test_bb, then_bb, else_bb, join_bb);
1810 /* Attempt to convert an IF-THEN or IF-THEN-ELSE block into
1811 straight line code. Return true if successful. */
1814 process_if_block (test_bb, then_bb, else_bb, join_bb)
1815 basic_block test_bb; /* Basic block test is in */
1816 basic_block then_bb; /* Basic block for THEN block */
1817 basic_block else_bb; /* Basic block for ELSE block */
1818 basic_block join_bb; /* Basic block the join label is in */
1820 if (! reload_completed
1821 && noce_process_if_block (test_bb, then_bb, else_bb, join_bb))
1824 if (HAVE_conditional_execution
1826 && cond_exec_process_if_block (test_bb, then_bb, else_bb, join_bb))
1832 /* Merge the blocks and mark for local life update. */
1835 merge_if_block (test_bb, then_bb, else_bb, join_bb)
1836 basic_block test_bb; /* Basic block test is in */
1837 basic_block then_bb; /* Basic block for THEN block */
1838 basic_block else_bb; /* Basic block for ELSE block */
1839 basic_block join_bb; /* Basic block the join label is in */
1841 basic_block combo_bb;
1843 /* All block merging is done into the lower block numbers. */
1847 /* First merge TEST block into THEN block. This is a no-brainer since
1848 the THEN block did not have a code label to begin with. */
1852 COPY_REG_SET (combo_bb->global_live_at_end,
1853 then_bb->global_live_at_end);
1854 merge_blocks_nomove (combo_bb, then_bb);
1855 num_removed_blocks++;
1858 /* The ELSE block, if it existed, had a label. That label count
1859 will almost always be zero, but odd things can happen when labels
1860 get their addresses taken. */
1863 merge_blocks_nomove (combo_bb, else_bb);
1864 num_removed_blocks++;
1867 /* If there was no join block reported, that means it was not adjacent
1868 to the others, and so we cannot merge them. */
1872 rtx last = combo_bb->end;
1874 /* The outgoing edge for the current COMBO block should already
1875 be correct. Verify this. */
1876 if (combo_bb->succ == NULL_EDGE)
1878 if (find_reg_note (last, REG_NORETURN, NULL))
1880 else if (GET_CODE (last) == INSN
1881 && GET_CODE (PATTERN (last)) == TRAP_IF
1882 && TRAP_CONDITION (PATTERN (last)) == const_true_rtx)
1888 /* There should still be something at the end of the THEN or ELSE
1889 blocks taking us to our final destination. */
1890 else if (GET_CODE (last) == JUMP_INSN)
1892 else if (combo_bb->succ->dest == EXIT_BLOCK_PTR
1893 && GET_CODE (last) == CALL_INSN
1894 && SIBLING_CALL_P (last))
1896 else if ((combo_bb->succ->flags & EDGE_EH)
1897 && can_throw_internal (last))
1903 /* The JOIN block may have had quite a number of other predecessors too.
1904 Since we've already merged the TEST, THEN and ELSE blocks, we should
1905 have only one remaining edge from our if-then-else diamond. If there
1906 is more than one remaining edge, it must come from elsewhere. There
1907 may be zero incoming edges if the THEN block didn't actually join
1908 back up (as with a call to abort). */
1909 else if ((join_bb->pred == NULL
1910 || join_bb->pred->pred_next == NULL)
1911 && join_bb != EXIT_BLOCK_PTR)
1913 /* We can merge the JOIN. */
1915 COPY_REG_SET (combo_bb->global_live_at_end,
1916 join_bb->global_live_at_end);
1917 merge_blocks_nomove (combo_bb, join_bb);
1918 num_removed_blocks++;
1922 /* We cannot merge the JOIN. */
1924 /* The outgoing edge for the current COMBO block should already
1925 be correct. Verify this. */
1926 if (combo_bb->succ->succ_next != NULL_EDGE
1927 || combo_bb->succ->dest != join_bb)
1930 /* Remove the jump and cruft from the end of the COMBO block. */
1931 if (join_bb != EXIT_BLOCK_PTR)
1932 tidy_fallthru_edge (combo_bb->succ, combo_bb, join_bb);
1935 /* Make sure we update life info properly. */
1936 SET_UPDATE_LIFE (combo_bb);
1938 num_updated_if_blocks++;
1941 /* Find a block ending in a simple IF condition. Return TRUE if
1942 we were able to transform it in some way. */
1945 find_if_header (test_bb)
1946 basic_block test_bb;
1951 /* The kind of block we're looking for has exactly two successors. */
1952 if ((then_edge = test_bb->succ) == NULL_EDGE
1953 || (else_edge = then_edge->succ_next) == NULL_EDGE
1954 || else_edge->succ_next != NULL_EDGE)
1957 /* Neither edge should be abnormal. */
1958 if ((then_edge->flags & EDGE_COMPLEX)
1959 || (else_edge->flags & EDGE_COMPLEX))
1962 /* The THEN edge is canonically the one that falls through. */
1963 if (then_edge->flags & EDGE_FALLTHRU)
1965 else if (else_edge->flags & EDGE_FALLTHRU)
1968 else_edge = then_edge;
1972 /* Otherwise this must be a multiway branch of some sort. */
1975 if (find_if_block (test_bb, then_edge, else_edge))
1977 if (HAVE_trap && HAVE_conditional_trap
1978 && find_cond_trap (test_bb, then_edge, else_edge))
1981 && (! HAVE_conditional_execution || reload_completed))
1983 if (find_if_case_1 (test_bb, then_edge, else_edge))
1985 if (find_if_case_2 (test_bb, then_edge, else_edge))
1993 fprintf (rtl_dump_file, "Conversion succeeded.\n");
1997 /* Determine if a given basic block heads a simple IF-THEN or IF-THEN-ELSE
1998 block. If so, we'll try to convert the insns to not require the branch.
1999 Return TRUE if we were successful at converting the the block. */
2002 find_if_block (test_bb, then_edge, else_edge)
2003 basic_block test_bb;
2004 edge then_edge, else_edge;
2006 basic_block then_bb = then_edge->dest;
2007 basic_block else_bb = else_edge->dest;
2008 basic_block join_bb = NULL_BLOCK;
2009 edge then_succ = then_bb->succ;
2010 edge else_succ = else_bb->succ;
2013 /* The THEN block of an IF-THEN combo must have exactly one predecessor. */
2014 if (then_bb->pred->pred_next != NULL_EDGE)
2017 /* The THEN block of an IF-THEN combo must have zero or one successors. */
2018 if (then_succ != NULL_EDGE
2019 && (then_succ->succ_next != NULL_EDGE
2020 || (then_succ->flags & EDGE_COMPLEX)))
2023 /* If the THEN block has no successors, conditional execution can still
2024 make a conditional call. Don't do this unless the ELSE block has
2025 only one incoming edge -- the CFG manipulation is too ugly otherwise.
2026 Check for the last insn of the THEN block being an indirect jump, which
2027 is listed as not having any successors, but confuses the rest of the CE
2028 code processing. XXX we should fix this in the future. */
2029 if (then_succ == NULL)
2031 if (else_bb->pred->pred_next == NULL_EDGE)
2033 rtx last_insn = then_bb->end;
2036 && GET_CODE (last_insn) == NOTE
2037 && last_insn != then_bb->head)
2038 last_insn = PREV_INSN (last_insn);
2041 && GET_CODE (last_insn) == JUMP_INSN
2042 && ! simplejump_p (last_insn))
2046 else_bb = NULL_BLOCK;
2052 /* If the THEN block's successor is the other edge out of the TEST block,
2053 then we have an IF-THEN combo without an ELSE. */
2054 else if (then_succ->dest == else_bb)
2057 else_bb = NULL_BLOCK;
2060 /* If the THEN and ELSE block meet in a subsequent block, and the ELSE
2061 has exactly one predecessor and one successor, and the outgoing edge
2062 is not complex, then we have an IF-THEN-ELSE combo. */
2063 else if (else_succ != NULL_EDGE
2064 && then_succ->dest == else_succ->dest
2065 && else_bb->pred->pred_next == NULL_EDGE
2066 && else_succ->succ_next == NULL_EDGE
2067 && ! (else_succ->flags & EDGE_COMPLEX))
2068 join_bb = else_succ->dest;
2070 /* Otherwise it is not an IF-THEN or IF-THEN-ELSE combination. */
2074 num_possible_if_blocks++;
2079 fprintf (rtl_dump_file,
2080 "\nIF-THEN-ELSE block found, start %d, then %d, else %d, join %d\n",
2081 test_bb->index, then_bb->index, else_bb->index,
2084 fprintf (rtl_dump_file,
2085 "\nIF-THEN block found, start %d, then %d, join %d\n",
2086 test_bb->index, then_bb->index, join_bb->index);
2089 /* Make sure IF, THEN, and ELSE, blocks are adjacent. Actually, we
2090 get the first condition for free, since we've already asserted that
2091 there's a fallthru edge from IF to THEN. */
2092 /* ??? As an enhancement, move the ELSE block. Have to deal with
2093 BLOCK notes, if by no other means than aborting the merge if they
2094 exist. Sticky enough I don't want to think about it now. */
2095 next_index = then_bb->index;
2096 if (else_bb && ++next_index != else_bb->index)
2098 if (++next_index != join_bb->index && join_bb->index != EXIT_BLOCK)
2106 /* Do the real work. */
2107 return process_if_block (test_bb, then_bb, else_bb, join_bb);
2110 /* Convert a branch over a trap, or a branch to a trap,
2111 into a conditional trap. */
2114 find_cond_trap (test_bb, then_edge, else_edge)
2115 basic_block test_bb;
2116 edge then_edge, else_edge;
2118 basic_block then_bb, else_bb, trap_bb, other_bb;
2119 rtx trap, jump, cond, cond_earliest, seq;
2122 then_bb = then_edge->dest;
2123 else_bb = else_edge->dest;
2125 /* Locate the block with the trap instruction. */
2126 /* ??? While we look for no successors, we really ought to allow
2127 EH successors. Need to fix merge_if_block for that to work. */
2128 if ((trap = block_has_only_trap (then_bb)) != NULL)
2129 trap_bb = then_bb, other_bb = else_bb;
2130 else if ((trap = block_has_only_trap (else_bb)) != NULL)
2131 trap_bb = else_bb, other_bb = then_bb;
2137 fprintf (rtl_dump_file, "\nTRAP-IF block found, start %d, trap %d\n",
2138 test_bb->index, trap_bb->index);
2141 /* If this is not a standard conditional jump, we can't parse it. */
2142 jump = test_bb->end;
2143 cond = noce_get_condition (jump, &cond_earliest);
2147 /* If the conditional jump is more than just a conditional jump,
2148 then we can not do if-conversion on this block. */
2149 if (! onlyjump_p (jump))
2152 /* We must be comparing objects whose modes imply the size. */
2153 if (GET_MODE (XEXP (cond, 0)) == BLKmode)
2156 /* Reverse the comparison code, if necessary. */
2157 code = GET_CODE (cond);
2158 if (then_bb == trap_bb)
2160 code = reversed_comparison_code (cond, jump);
2161 if (code == UNKNOWN)
2165 /* Attempt to generate the conditional trap. */
2166 seq = gen_cond_trap (code, XEXP (cond, 0), XEXP (cond, 1),
2167 TRAP_CODE (PATTERN (trap)));
2171 /* Emit the new insns before cond_earliest. */
2172 emit_insn_before (seq, cond_earliest);
2174 /* Delete the trap block if possible. */
2175 remove_edge (trap_bb == then_bb ? then_edge : else_edge);
2176 if (trap_bb->pred == NULL)
2178 flow_delete_block (trap_bb);
2179 num_removed_blocks++;
2182 /* If the non-trap block and the test are now adjacent, merge them.
2183 Otherwise we must insert a direct branch. */
2184 if (test_bb->index + 1 == other_bb->index)
2187 merge_if_block (test_bb, NULL, NULL, other_bb);
2193 lab = JUMP_LABEL (jump);
2194 newjump = emit_jump_insn_after (gen_jump (lab), jump);
2195 LABEL_NUSES (lab) += 1;
2196 JUMP_LABEL (newjump) = lab;
2197 emit_barrier_after (newjump);
2205 /* Subroutine of find_cond_trap: if BB contains only a trap insn,
2209 block_has_only_trap (bb)
2214 /* We're not the exit block. */
2215 if (bb == EXIT_BLOCK_PTR)
2218 /* The block must have no successors. */
2222 /* The only instruction in the THEN block must be the trap. */
2223 trap = first_active_insn (bb);
2224 if (! (trap == bb->end
2225 && GET_CODE (PATTERN (trap)) == TRAP_IF
2226 && TRAP_CONDITION (PATTERN (trap)) == const_true_rtx))
2232 /* Look for IF-THEN-ELSE cases in which one of THEN or ELSE is
2233 transformable, but not necessarily the other. There need be no
2236 Return TRUE if we were successful at converting the the block.
2238 Cases we'd like to look at:
2241 if (test) goto over; // x not live
2249 if (! test) goto label;
2252 if (test) goto E; // x not live
2266 (3) // This one's really only interesting for targets that can do
2267 // multiway branching, e.g. IA-64 BBB bundles. For other targets
2268 // it results in multiple branches on a cache line, which often
2269 // does not sit well with predictors.
2271 if (test1) goto E; // predicted not taken
2287 (A) Don't do (2) if the branch is predicted against the block we're
2288 eliminating. Do it anyway if we can eliminate a branch; this requires
2289 that the sole successor of the eliminated block postdominate the other
2292 (B) With CE, on (3) we can steal from both sides of the if, creating
2301 Again, this is most useful if J postdominates.
2303 (C) CE substitutes for helpful life information.
2305 (D) These heuristics need a lot of work. */
2307 /* Tests for case 1 above. */
2310 find_if_case_1 (test_bb, then_edge, else_edge)
2311 basic_block test_bb;
2312 edge then_edge, else_edge;
2314 basic_block then_bb = then_edge->dest;
2315 basic_block else_bb = else_edge->dest, new_bb;
2316 edge then_succ = then_bb->succ;
2318 /* THEN has one successor. */
2319 if (!then_succ || then_succ->succ_next != NULL)
2322 /* THEN does not fall through, but is not strange either. */
2323 if (then_succ->flags & (EDGE_COMPLEX | EDGE_FALLTHRU))
2326 /* THEN has one predecessor. */
2327 if (then_bb->pred->pred_next != NULL)
2330 /* THEN must do something. */
2331 if (forwarder_block_p (then_bb))
2334 num_possible_if_blocks++;
2336 fprintf (rtl_dump_file,
2337 "\nIF-CASE-1 found, start %d, then %d\n",
2338 test_bb->index, then_bb->index);
2340 /* THEN is small. */
2341 if (count_bb_insns (then_bb) > BRANCH_COST)
2344 /* Registers set are dead, or are predicable. */
2345 if (! dead_or_predicable (test_bb, then_bb, else_bb,
2346 then_bb->succ->dest, 1))
2349 /* Conversion went ok, including moving the insns and fixing up the
2350 jump. Adjust the CFG to match. */
2352 SET_UPDATE_LIFE (test_bb);
2353 bitmap_operation (test_bb->global_live_at_end,
2354 else_bb->global_live_at_start,
2355 then_bb->global_live_at_end, BITMAP_IOR);
2357 new_bb = redirect_edge_and_branch_force (FALLTHRU_EDGE (test_bb), else_bb);
2358 /* Make rest of code believe that the newly created block is the THEN_BB
2359 block we are going to remove. */
2362 new_bb->aux = then_bb->aux;
2363 SET_UPDATE_LIFE (then_bb);
2365 flow_delete_block (then_bb);
2366 /* We've possibly created jump to next insn, cleanup_cfg will solve that
2369 num_removed_blocks++;
2370 num_updated_if_blocks++;
2375 /* Test for case 2 above. */
2378 find_if_case_2 (test_bb, then_edge, else_edge)
2379 basic_block test_bb;
2380 edge then_edge, else_edge;
2382 basic_block then_bb = then_edge->dest;
2383 basic_block else_bb = else_edge->dest;
2384 edge else_succ = else_bb->succ;
2387 /* ELSE has one successor. */
2388 if (!else_succ || else_succ->succ_next != NULL)
2391 /* ELSE outgoing edge is not complex. */
2392 if (else_succ->flags & EDGE_COMPLEX)
2395 /* ELSE has one predecessor. */
2396 if (else_bb->pred->pred_next != NULL)
2399 /* THEN is not EXIT. */
2400 if (then_bb->index < 0)
2403 /* ELSE is predicted or SUCC(ELSE) postdominates THEN. */
2404 note = find_reg_note (test_bb->end, REG_BR_PROB, NULL_RTX);
2405 if (note && INTVAL (XEXP (note, 0)) >= REG_BR_PROB_BASE / 2)
2407 else if (else_succ->dest->index < 0
2408 || TEST_BIT (post_dominators[ORIG_INDEX (then_bb)],
2409 ORIG_INDEX (else_succ->dest)))
2414 num_possible_if_blocks++;
2416 fprintf (rtl_dump_file,
2417 "\nIF-CASE-2 found, start %d, else %d\n",
2418 test_bb->index, else_bb->index);
2420 /* ELSE is small. */
2421 if (count_bb_insns (then_bb) > BRANCH_COST)
2424 /* Registers set are dead, or are predicable. */
2425 if (! dead_or_predicable (test_bb, else_bb, then_bb, else_succ->dest, 0))
2428 /* Conversion went ok, including moving the insns and fixing up the
2429 jump. Adjust the CFG to match. */
2431 SET_UPDATE_LIFE (test_bb);
2432 bitmap_operation (test_bb->global_live_at_end,
2433 then_bb->global_live_at_start,
2434 else_bb->global_live_at_end, BITMAP_IOR);
2436 flow_delete_block (else_bb);
2438 num_removed_blocks++;
2439 num_updated_if_blocks++;
2441 /* ??? We may now fallthru from one of THEN's successors into a join
2442 block. Rerun cleanup_cfg? Examine things manually? Wait? */
2447 /* A subroutine of dead_or_predicable called through for_each_rtx.
2448 Return 1 if a memory is found. */
2451 find_memory (px, data)
2453 void *data ATTRIBUTE_UNUSED;
2455 return GET_CODE (*px) == MEM;
2458 /* Used by the code above to perform the actual rtl transformations.
2459 Return TRUE if successful.
2461 TEST_BB is the block containing the conditional branch. MERGE_BB
2462 is the block containing the code to manipulate. NEW_DEST is the
2463 label TEST_BB should be branching to after the conversion.
2464 REVERSEP is true if the sense of the branch should be reversed. */
2467 dead_or_predicable (test_bb, merge_bb, other_bb, new_dest, reversep)
2468 basic_block test_bb, merge_bb, other_bb;
2469 basic_block new_dest;
2472 rtx head, end, jump, earliest, old_dest, new_label = NULL_RTX;
2474 jump = test_bb->end;
2476 /* Find the extent of the real code in the merge block. */
2477 head = merge_bb->head;
2478 end = merge_bb->end;
2480 if (GET_CODE (head) == CODE_LABEL)
2481 head = NEXT_INSN (head);
2482 if (GET_CODE (head) == NOTE)
2486 head = end = NULL_RTX;
2489 head = NEXT_INSN (head);
2492 if (GET_CODE (end) == JUMP_INSN)
2496 head = end = NULL_RTX;
2499 end = PREV_INSN (end);
2502 /* Disable handling dead code by conditional execution if the machine needs
2503 to do anything funny with the tests, etc. */
2504 #ifndef IFCVT_MODIFY_TESTS
2505 if (HAVE_conditional_execution)
2507 /* In the conditional execution case, we have things easy. We know
2508 the condition is reversable. We don't have to check life info,
2509 becase we're going to conditionally execute the code anyway.
2510 All that's left is making sure the insns involved can actually
2515 cond = cond_exec_get_condition (jump);
2519 prob_val = find_reg_note (jump, REG_BR_PROB, NULL_RTX);
2521 prob_val = XEXP (prob_val, 0);
2525 enum rtx_code rev = reversed_comparison_code (cond, jump);
2528 cond = gen_rtx_fmt_ee (rev, GET_MODE (cond), XEXP (cond, 0),
2531 prob_val = GEN_INT (REG_BR_PROB_BASE - INTVAL (prob_val));
2534 if (! cond_exec_process_insns (head, end, cond, prob_val, 0))
2542 /* In the non-conditional execution case, we have to verify that there
2543 are no trapping operations, no calls, no references to memory, and
2544 that any registers modified are dead at the branch site. */
2546 rtx insn, cond, prev;
2547 regset_head merge_set_head, tmp_head, test_live_head, test_set_head;
2548 regset merge_set, tmp, test_live, test_set;
2549 struct propagate_block_info *pbi;
2552 /* Check for no calls or trapping operations. */
2553 for (insn = head; ; insn = NEXT_INSN (insn))
2555 if (GET_CODE (insn) == CALL_INSN)
2559 if (may_trap_p (PATTERN (insn)))
2562 /* ??? Even non-trapping memories such as stack frame
2563 references must be avoided. For stores, we collect
2564 no lifetime info; for reads, we'd have to assert
2565 true_dependence false against every store in the
2567 if (for_each_rtx (&PATTERN (insn), find_memory, NULL))
2574 if (! any_condjump_p (jump))
2577 /* Find the extent of the conditional. */
2578 cond = noce_get_condition (jump, &earliest);
2583 MERGE_SET = set of registers set in MERGE_BB
2584 TEST_LIVE = set of registers live at EARLIEST
2585 TEST_SET = set of registers set between EARLIEST and the
2586 end of the block. */
2588 tmp = INITIALIZE_REG_SET (tmp_head);
2589 merge_set = INITIALIZE_REG_SET (merge_set_head);
2590 test_live = INITIALIZE_REG_SET (test_live_head);
2591 test_set = INITIALIZE_REG_SET (test_set_head);
2593 /* ??? bb->local_set is only valid during calculate_global_regs_live,
2594 so we must recompute usage for MERGE_BB. Not so bad, I suppose,
2595 since we've already asserted that MERGE_BB is small. */
2596 propagate_block (merge_bb, tmp, merge_set, merge_set, 0);
2598 /* For small register class machines, don't lengthen lifetimes of
2599 hard registers before reload. */
2600 if (SMALL_REGISTER_CLASSES && ! reload_completed)
2602 EXECUTE_IF_SET_IN_BITMAP
2605 if (i < FIRST_PSEUDO_REGISTER
2607 && ! global_regs[i])
2612 /* For TEST, we're interested in a range of insns, not a whole block.
2613 Moreover, we're interested in the insns live from OTHER_BB. */
2615 COPY_REG_SET (test_live, other_bb->global_live_at_start);
2616 pbi = init_propagate_block_info (test_bb, test_live, test_set, test_set,
2619 for (insn = jump; ; insn = prev)
2621 prev = propagate_one_insn (pbi, insn);
2622 if (insn == earliest)
2626 free_propagate_block_info (pbi);
2628 /* We can perform the transformation if
2629 MERGE_SET & (TEST_SET | TEST_LIVE)
2631 TEST_SET & merge_bb->global_live_at_start
2634 bitmap_operation (tmp, test_set, test_live, BITMAP_IOR);
2635 bitmap_operation (tmp, tmp, merge_set, BITMAP_AND);
2636 EXECUTE_IF_SET_IN_BITMAP(tmp, 0, i, fail = 1);
2638 bitmap_operation (tmp, test_set, merge_bb->global_live_at_start,
2640 EXECUTE_IF_SET_IN_BITMAP(tmp, 0, i, fail = 1);
2643 FREE_REG_SET (merge_set);
2644 FREE_REG_SET (test_live);
2645 FREE_REG_SET (test_set);
2652 /* We don't want to use normal invert_jump or redirect_jump because
2653 we don't want to delete_insn called. Also, we want to do our own
2654 change group management. */
2656 old_dest = JUMP_LABEL (jump);
2657 if (other_bb != new_dest)
2659 new_label = block_label (new_dest);
2661 ? ! invert_jump_1 (jump, new_label)
2662 : ! redirect_jump_1 (jump, new_label))
2666 if (! apply_change_group ())
2669 if (other_bb != new_dest)
2672 LABEL_NUSES (old_dest) -= 1;
2674 LABEL_NUSES (new_label) += 1;
2675 JUMP_LABEL (jump) = new_label;
2677 invert_br_probabilities (jump);
2679 redirect_edge_succ (BRANCH_EDGE (test_bb), new_dest);
2682 gcov_type count, probability;
2683 count = BRANCH_EDGE (test_bb)->count;
2684 BRANCH_EDGE (test_bb)->count = FALLTHRU_EDGE (test_bb)->count;
2685 FALLTHRU_EDGE (test_bb)->count = count;
2686 probability = BRANCH_EDGE (test_bb)->probability;
2687 BRANCH_EDGE (test_bb)->probability
2688 = FALLTHRU_EDGE (test_bb)->probability;
2689 FALLTHRU_EDGE (test_bb)->probability = probability;
2690 update_br_prob_note (test_bb);
2694 /* Move the insns out of MERGE_BB to before the branch. */
2697 if (end == merge_bb->end)
2698 merge_bb->end = PREV_INSN (head);
2700 if (squeeze_notes (&head, &end))
2703 reorder_insns (head, end, PREV_INSN (earliest));
2706 /* Remove the jump and edge if we can. */
2707 if (other_bb == new_dest)
2710 remove_edge (BRANCH_EDGE (test_bb));
2711 /* ??? Can't merge blocks here, as then_bb is still in use.
2712 At minimum, the merge will get done just before bb-reorder. */
2722 /* Main entry point for all if-conversion. */
2725 if_convert (x_life_data_ok)
2730 num_possible_if_blocks = 0;
2731 num_updated_if_blocks = 0;
2732 num_removed_blocks = 0;
2733 life_data_ok = (x_life_data_ok != 0);
2735 /* Free up basic_block_for_insn so that we don't have to keep it
2736 up to date, either here or in merge_blocks_nomove. */
2737 free_basic_block_vars (1);
2739 /* Compute postdominators if we think we'll use them. */
2740 post_dominators = NULL;
2741 if (HAVE_conditional_execution || life_data_ok)
2743 post_dominators = sbitmap_vector_alloc (n_basic_blocks, n_basic_blocks);
2744 calculate_dominance_info (NULL, post_dominators, CDI_POST_DOMINATORS);
2747 /* Record initial block numbers. */
2748 for (block_num = 0; block_num < n_basic_blocks; block_num++)
2749 SET_ORIG_INDEX (BASIC_BLOCK (block_num), block_num);
2751 /* Go through each of the basic blocks looking for things to convert. */
2752 for (block_num = 0; block_num < n_basic_blocks; )
2754 basic_block bb = BASIC_BLOCK (block_num);
2755 if (find_if_header (bb))
2756 block_num = bb->index;
2761 if (post_dominators)
2762 sbitmap_vector_free (post_dominators);
2765 fflush (rtl_dump_file);
2767 /* Rebuild life info for basic blocks that require it. */
2768 if (num_removed_blocks && life_data_ok)
2770 sbitmap update_life_blocks = sbitmap_alloc (n_basic_blocks);
2771 sbitmap_zero (update_life_blocks);
2773 /* If we allocated new pseudos, we must resize the array for sched1. */
2774 if (max_regno < max_reg_num ())
2776 max_regno = max_reg_num ();
2777 allocate_reg_info (max_regno, FALSE, FALSE);
2780 for (block_num = 0; block_num < n_basic_blocks; block_num++)
2781 if (UPDATE_LIFE (BASIC_BLOCK (block_num)))
2782 SET_BIT (update_life_blocks, block_num);
2784 clear_aux_for_blocks ();
2785 count_or_remove_death_notes (update_life_blocks, 1);
2786 /* ??? See about adding a mode that verifies that the initial
2787 set of blocks don't let registers come live. */
2788 update_life_info (update_life_blocks, UPDATE_LIFE_GLOBAL,
2789 PROP_DEATH_NOTES | PROP_SCAN_DEAD_CODE
2790 | PROP_KILL_DEAD_CODE);
2792 sbitmap_free (update_life_blocks);
2795 clear_aux_for_blocks ();
2797 /* Write the final stats. */
2798 if (rtl_dump_file && num_possible_if_blocks > 0)
2800 fprintf (rtl_dump_file,
2801 "\n%d possible IF blocks searched.\n",
2802 num_possible_if_blocks);
2803 fprintf (rtl_dump_file,
2804 "%d IF blocks converted.\n",
2805 num_updated_if_blocks);
2806 fprintf (rtl_dump_file,
2807 "%d basic blocks deleted.\n\n\n",
2808 num_removed_blocks);
2811 #ifdef ENABLE_CHECKING
2812 verify_flow_info ();