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"
30 #include "hard-reg-set.h"
31 #include "basic-block.h"
39 #ifndef HAVE_conditional_execution
40 #define HAVE_conditional_execution 0
42 #ifndef HAVE_conditional_move
43 #define HAVE_conditional_move 0
54 #ifndef HAVE_conditional_trap
55 #define HAVE_conditional_trap 0
58 #ifndef MAX_CONDITIONAL_EXECUTE
59 #define MAX_CONDITIONAL_EXECUTE (BRANCH_COST + 1)
62 #define NULL_EDGE ((struct edge_def *)NULL)
63 #define NULL_BLOCK ((struct basic_block_def *)NULL)
65 /* # of IF-THEN or IF-THEN-ELSE blocks we looked at */
66 static int num_possible_if_blocks;
68 /* # of IF-THEN or IF-THEN-ELSE blocks were converted to conditional
70 static int num_updated_if_blocks;
72 /* # of basic blocks that were removed. */
73 static int num_removed_blocks;
75 /* True if life data ok at present. */
76 static bool life_data_ok;
78 /* The post-dominator relation on the original block numbers. */
79 static sbitmap *post_dominators;
81 /* Forward references. */
82 static int count_bb_insns PARAMS ((basic_block));
83 static rtx first_active_insn PARAMS ((basic_block));
84 static int last_active_insn_p PARAMS ((basic_block, rtx));
85 static int seq_contains_jump PARAMS ((rtx));
87 static int cond_exec_process_insns PARAMS ((rtx, rtx, rtx, rtx, int));
88 static rtx cond_exec_get_condition PARAMS ((rtx));
89 static int cond_exec_process_if_block PARAMS ((basic_block, basic_block,
90 basic_block, basic_block));
92 static rtx noce_get_condition PARAMS ((rtx, rtx *));
93 static int noce_operand_ok PARAMS ((rtx));
94 static int noce_process_if_block PARAMS ((basic_block, basic_block,
95 basic_block, basic_block));
97 static int process_if_block PARAMS ((basic_block, basic_block,
98 basic_block, basic_block));
99 static void merge_if_block PARAMS ((basic_block, basic_block,
100 basic_block, basic_block));
102 static int find_if_header PARAMS ((basic_block));
103 static int find_if_block PARAMS ((basic_block, edge, edge));
104 static int find_if_case_1 PARAMS ((basic_block, edge, edge));
105 static int find_if_case_2 PARAMS ((basic_block, edge, edge));
106 static int find_cond_trap PARAMS ((basic_block, edge, edge));
107 static int find_memory PARAMS ((rtx *, void *));
108 static int dead_or_predicable PARAMS ((basic_block, basic_block,
109 basic_block, basic_block, int));
110 static void noce_emit_move_insn PARAMS ((rtx, rtx));
112 /* Abuse the basic_block AUX field to store the original block index,
113 as well as a flag indicating that the block should be rescaned for
116 #define SET_ORIG_INDEX(BB,I) ((BB)->aux = (void *)((size_t)(I) << 1))
117 #define ORIG_INDEX(BB) ((size_t)(BB)->aux >> 1)
118 #define SET_UPDATE_LIFE(BB) ((BB)->aux = (void *)((size_t)(BB)->aux | 1))
119 #define UPDATE_LIFE(BB) ((size_t)(BB)->aux & 1)
122 /* Count the number of non-jump active insns in BB. */
133 if (GET_CODE (insn) == CALL_INSN || GET_CODE (insn) == INSN)
138 insn = NEXT_INSN (insn);
144 /* Return the first non-jump active insn in the basic block. */
147 first_active_insn (bb)
152 if (GET_CODE (insn) == CODE_LABEL)
156 insn = NEXT_INSN (insn);
159 while (GET_CODE (insn) == NOTE)
163 insn = NEXT_INSN (insn);
166 if (GET_CODE (insn) == JUMP_INSN)
172 /* Return true if INSN is the last active non-jump insn in BB. */
175 last_active_insn_p (bb, insn)
183 insn = NEXT_INSN (insn);
185 while (GET_CODE (insn) == NOTE);
187 return GET_CODE (insn) == JUMP_INSN;
190 /* It is possible, especially when having dealt with multi-word
191 arithmetic, for the expanders to have emitted jumps. Search
192 through the sequence and return TRUE if a jump exists so that
193 we can abort the conversion. */
196 seq_contains_jump (insn)
201 if (GET_CODE (insn) == JUMP_INSN)
203 insn = NEXT_INSN (insn);
208 /* Go through a bunch of insns, converting them to conditional
209 execution format if possible. Return TRUE if all of the non-note
210 insns were processed. */
213 cond_exec_process_insns (start, end, test, prob_val, mod_ok)
214 rtx start; /* first insn to look at */
215 rtx end; /* last insn to look at */
216 rtx test; /* conditional execution test */
217 rtx prob_val; /* probability of branch taken. */
218 int mod_ok; /* true if modifications ok last insn. */
220 int must_be_last = FALSE;
224 for (insn = start; ; insn = NEXT_INSN (insn))
226 if (GET_CODE (insn) == NOTE)
229 if (GET_CODE (insn) != INSN && GET_CODE (insn) != CALL_INSN)
232 /* Remove USE insns that get in the way. */
233 if (reload_completed && GET_CODE (PATTERN (insn)) == USE)
235 /* ??? Ug. Actually unlinking the thing is problematic,
236 given what we'd have to coordinate with our callers. */
237 PUT_CODE (insn, NOTE);
238 NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
239 NOTE_SOURCE_FILE (insn) = 0;
243 /* Last insn wasn't last? */
247 if (modified_in_p (test, insn))
254 /* Now build the conditional form of the instruction. */
255 pattern = PATTERN (insn);
257 /* If the machine needs to modify the insn being conditionally executed,
258 say for example to force a constant integer operand into a temp
259 register, do so here. */
260 #ifdef IFCVT_MODIFY_INSN
261 IFCVT_MODIFY_INSN (pattern, insn);
266 validate_change (insn, &PATTERN (insn),
267 gen_rtx_COND_EXEC (VOIDmode, copy_rtx (test),
270 if (GET_CODE (insn) == CALL_INSN && prob_val)
271 validate_change (insn, ®_NOTES (insn),
272 alloc_EXPR_LIST (REG_BR_PROB, prob_val,
273 REG_NOTES (insn)), 1);
283 /* Return the condition for a jump. Do not do any special processing. */
286 cond_exec_get_condition (jump)
291 if (any_condjump_p (jump))
292 test_if = SET_SRC (pc_set (jump));
295 cond = XEXP (test_if, 0);
297 /* If this branches to JUMP_LABEL when the condition is false,
298 reverse the condition. */
299 if (GET_CODE (XEXP (test_if, 2)) == LABEL_REF
300 && XEXP (XEXP (test_if, 2), 0) == JUMP_LABEL (jump))
302 enum rtx_code rev = reversed_comparison_code (cond, jump);
306 cond = gen_rtx_fmt_ee (rev, GET_MODE (cond), XEXP (cond, 0),
313 /* Given a simple IF-THEN or IF-THEN-ELSE block, attempt to convert it
314 to conditional execution. Return TRUE if we were successful at
315 converting the the block. */
318 cond_exec_process_if_block (test_bb, then_bb, else_bb, join_bb)
319 basic_block test_bb; /* Basic block test is in */
320 basic_block then_bb; /* Basic block for THEN block */
321 basic_block else_bb; /* Basic block for ELSE block */
322 basic_block join_bb; /* Basic block the join label is in */
324 rtx test_expr; /* expression in IF_THEN_ELSE that is tested */
325 rtx then_start; /* first insn in THEN block */
326 rtx then_end; /* last insn + 1 in THEN block */
327 rtx else_start = NULL_RTX; /* first insn in ELSE block or NULL */
328 rtx else_end = NULL_RTX; /* last insn + 1 in ELSE block */
329 int max; /* max # of insns to convert. */
330 int then_mod_ok; /* whether conditional mods are ok in THEN */
331 rtx true_expr; /* test for else block insns */
332 rtx false_expr; /* test for then block insns */
333 rtx true_prob_val; /* probability of else block */
334 rtx false_prob_val; /* probability of then block */
336 enum rtx_code false_code;
338 /* Find the conditional jump to the ELSE or JOIN part, and isolate
340 test_expr = cond_exec_get_condition (test_bb->end);
344 /* If the conditional jump is more than just a conditional jump,
345 then we can not do conditional execution conversion on this block. */
346 if (!onlyjump_p (test_bb->end))
349 /* Collect the bounds of where we're to search. */
351 then_start = then_bb->head;
352 then_end = then_bb->end;
354 /* Skip a label heading THEN block. */
355 if (GET_CODE (then_start) == CODE_LABEL)
356 then_start = NEXT_INSN (then_start);
358 /* Skip a (use (const_int 0)) or branch as the final insn. */
359 if (GET_CODE (then_end) == INSN
360 && GET_CODE (PATTERN (then_end)) == USE
361 && GET_CODE (XEXP (PATTERN (then_end), 0)) == CONST_INT)
362 then_end = PREV_INSN (then_end);
363 else if (GET_CODE (then_end) == JUMP_INSN)
364 then_end = PREV_INSN (then_end);
368 /* Skip the ELSE block's label. */
369 else_start = NEXT_INSN (else_bb->head);
370 else_end = else_bb->end;
372 /* Skip a (use (const_int 0)) or branch as the final insn. */
373 if (GET_CODE (else_end) == INSN
374 && GET_CODE (PATTERN (else_end)) == USE
375 && GET_CODE (XEXP (PATTERN (else_end), 0)) == CONST_INT)
376 else_end = PREV_INSN (else_end);
377 else if (GET_CODE (else_end) == JUMP_INSN)
378 else_end = PREV_INSN (else_end);
381 /* How many instructions should we convert in total? */
385 max = 2 * MAX_CONDITIONAL_EXECUTE;
386 n_insns = count_bb_insns (else_bb);
389 max = MAX_CONDITIONAL_EXECUTE;
390 n_insns += count_bb_insns (then_bb);
394 /* Map test_expr/test_jump into the appropriate MD tests to use on
395 the conditionally executed code. */
397 true_expr = test_expr;
399 false_code = reversed_comparison_code (true_expr, test_bb->end);
400 if (false_code != UNKNOWN)
401 false_expr = gen_rtx_fmt_ee (false_code, GET_MODE (true_expr),
402 XEXP (true_expr, 0), XEXP (true_expr, 1));
404 false_expr = NULL_RTX;
406 #ifdef IFCVT_MODIFY_TESTS
407 /* If the machine description needs to modify the tests, such as setting a
408 conditional execution register from a comparison, it can do so here. */
409 IFCVT_MODIFY_TESTS (true_expr, false_expr, test_bb, then_bb, else_bb,
412 /* See if the conversion failed */
413 if (!true_expr || !false_expr)
417 true_prob_val = find_reg_note (test_bb->end, REG_BR_PROB, NULL_RTX);
420 true_prob_val = XEXP (true_prob_val, 0);
421 false_prob_val = GEN_INT (REG_BR_PROB_BASE - INTVAL (true_prob_val));
424 false_prob_val = NULL_RTX;
426 /* For IF-THEN-ELSE blocks, we don't allow modifications of the test
427 on then THEN block. */
428 then_mod_ok = (else_bb == NULL_BLOCK);
430 /* Go through the THEN and ELSE blocks converting the insns if possible
431 to conditional execution. */
435 || ! cond_exec_process_insns (then_start, then_end, false_expr,
436 false_prob_val, then_mod_ok)))
440 && ! cond_exec_process_insns (else_start, else_end,
441 true_expr, true_prob_val, TRUE))
444 if (! apply_change_group ())
447 #ifdef IFCVT_MODIFY_FINAL
448 /* Do any machine dependent final modifications */
449 IFCVT_MODIFY_FINAL (test_bb, then_bb, else_bb, join_bb);
452 /* Conversion succeeded. */
454 fprintf (rtl_dump_file, "%d insn%s converted to conditional execution.\n",
455 n_insns, (n_insns == 1) ? " was" : "s were");
457 /* Merge the blocks! */
458 merge_if_block (test_bb, then_bb, else_bb, join_bb);
462 #ifdef IFCVT_MODIFY_CANCEL
463 /* Cancel any machine dependent changes. */
464 IFCVT_MODIFY_CANCEL (test_bb, then_bb, else_bb, join_bb);
471 /* Used by noce_process_if_block to communicate with its subroutines.
473 The subroutines know that A and B may be evaluated freely. They
474 know that X is a register. They should insert new instructions
475 before cond_earliest. */
482 rtx jump, cond, cond_earliest;
485 static rtx noce_emit_store_flag PARAMS ((struct noce_if_info *,
487 static int noce_try_store_flag PARAMS ((struct noce_if_info *));
488 static int noce_try_store_flag_inc PARAMS ((struct noce_if_info *));
489 static int noce_try_store_flag_constants PARAMS ((struct noce_if_info *));
490 static int noce_try_store_flag_mask PARAMS ((struct noce_if_info *));
491 static rtx noce_emit_cmove PARAMS ((struct noce_if_info *,
492 rtx, enum rtx_code, rtx,
494 static int noce_try_cmove PARAMS ((struct noce_if_info *));
495 static int noce_try_cmove_arith PARAMS ((struct noce_if_info *));
496 static rtx noce_get_alt_condition PARAMS ((struct noce_if_info *,
498 static int noce_try_minmax PARAMS ((struct noce_if_info *));
499 static int noce_try_abs PARAMS ((struct noce_if_info *));
501 /* Helper function for noce_try_store_flag*. */
504 noce_emit_store_flag (if_info, x, reversep, normalize)
505 struct noce_if_info *if_info;
507 int reversep, normalize;
509 rtx cond = if_info->cond;
513 cond_complex = (! general_operand (XEXP (cond, 0), VOIDmode)
514 || ! general_operand (XEXP (cond, 1), VOIDmode));
516 /* If earliest == jump, or when the condition is complex, try to
517 build the store_flag insn directly. */
520 cond = XEXP (SET_SRC (pc_set (if_info->jump)), 0);
523 code = reversed_comparison_code (cond, if_info->jump);
525 code = GET_CODE (cond);
527 if ((if_info->cond_earliest == if_info->jump || cond_complex)
528 && (normalize == 0 || STORE_FLAG_VALUE == normalize))
532 tmp = gen_rtx_fmt_ee (code, GET_MODE (x), XEXP (cond, 0),
534 tmp = gen_rtx_SET (VOIDmode, x, tmp);
537 tmp = emit_insn (tmp);
539 if (recog_memoized (tmp) >= 0)
545 if_info->cond_earliest = if_info->jump;
553 /* Don't even try if the comparison operands are weird. */
557 return emit_store_flag (x, code, XEXP (cond, 0),
558 XEXP (cond, 1), VOIDmode,
559 (code == LTU || code == LEU
560 || code == GEU || code == GTU), normalize);
563 /* Emit instruction to move an rtx into STRICT_LOW_PART. */
565 noce_emit_move_insn (x, y)
568 enum machine_mode outmode, inmode;
572 if (GET_CODE (x) != STRICT_LOW_PART)
574 emit_move_insn (x, y);
579 inner = XEXP (outer, 0);
580 outmode = GET_MODE (outer);
581 inmode = GET_MODE (inner);
582 bitpos = SUBREG_BYTE (outer) * BITS_PER_UNIT;
583 store_bit_field (inner, GET_MODE_BITSIZE (outmode),
584 bitpos, outmode, y, GET_MODE_BITSIZE (inmode),
585 GET_MODE_BITSIZE (inmode));
588 /* Convert "if (test) x = 1; else x = 0".
590 Only try 0 and STORE_FLAG_VALUE here. Other combinations will be
591 tried in noce_try_store_flag_constants after noce_try_cmove has had
592 a go at the conversion. */
595 noce_try_store_flag (if_info)
596 struct noce_if_info *if_info;
601 if (GET_CODE (if_info->b) == CONST_INT
602 && INTVAL (if_info->b) == STORE_FLAG_VALUE
603 && if_info->a == const0_rtx)
605 else if (if_info->b == const0_rtx
606 && GET_CODE (if_info->a) == CONST_INT
607 && INTVAL (if_info->a) == STORE_FLAG_VALUE
608 && (reversed_comparison_code (if_info->cond, if_info->jump)
616 target = noce_emit_store_flag (if_info, if_info->x, reversep, 0);
619 if (target != if_info->x)
620 noce_emit_move_insn (if_info->x, target);
624 emit_insns_before (seq, if_info->cond_earliest);
635 /* Convert "if (test) x = a; else x = b", for A and B constant. */
638 noce_try_store_flag_constants (if_info)
639 struct noce_if_info *if_info;
643 HOST_WIDE_INT itrue, ifalse, diff, tmp;
644 int normalize, can_reverse;
645 enum machine_mode mode;
648 && GET_CODE (if_info->a) == CONST_INT
649 && GET_CODE (if_info->b) == CONST_INT)
651 mode = GET_MODE (if_info->x);
652 ifalse = INTVAL (if_info->a);
653 itrue = INTVAL (if_info->b);
654 diff = trunc_int_for_mode (itrue - ifalse, mode);
656 can_reverse = (reversed_comparison_code (if_info->cond, if_info->jump)
660 if (diff == STORE_FLAG_VALUE || diff == -STORE_FLAG_VALUE)
662 else if (ifalse == 0 && exact_log2 (itrue) >= 0
663 && (STORE_FLAG_VALUE == 1
664 || BRANCH_COST >= 2))
666 else if (itrue == 0 && exact_log2 (ifalse) >= 0 && can_reverse
667 && (STORE_FLAG_VALUE == 1 || BRANCH_COST >= 2))
668 normalize = 1, reversep = 1;
670 && (STORE_FLAG_VALUE == -1
671 || BRANCH_COST >= 2))
673 else if (ifalse == -1 && can_reverse
674 && (STORE_FLAG_VALUE == -1 || BRANCH_COST >= 2))
675 normalize = -1, reversep = 1;
676 else if ((BRANCH_COST >= 2 && STORE_FLAG_VALUE == -1)
684 tmp = itrue; itrue = ifalse; ifalse = tmp;
685 diff = trunc_int_for_mode (-diff, mode);
689 target = noce_emit_store_flag (if_info, if_info->x, reversep, normalize);
696 /* if (test) x = 3; else x = 4;
697 => x = 3 + (test == 0); */
698 if (diff == STORE_FLAG_VALUE || diff == -STORE_FLAG_VALUE)
700 target = expand_simple_binop (mode,
701 (diff == STORE_FLAG_VALUE
703 GEN_INT (ifalse), target, if_info->x, 0,
707 /* if (test) x = 8; else x = 0;
708 => x = (test != 0) << 3; */
709 else if (ifalse == 0 && (tmp = exact_log2 (itrue)) >= 0)
711 target = expand_simple_binop (mode, ASHIFT,
712 target, GEN_INT (tmp), if_info->x, 0,
716 /* if (test) x = -1; else x = b;
717 => x = -(test != 0) | b; */
718 else if (itrue == -1)
720 target = expand_simple_binop (mode, IOR,
721 target, GEN_INT (ifalse), if_info->x, 0,
725 /* if (test) x = a; else x = b;
726 => x = (-(test != 0) & (b - a)) + a; */
729 target = expand_simple_binop (mode, AND,
730 target, GEN_INT (diff), if_info->x, 0,
733 target = expand_simple_binop (mode, PLUS,
734 target, GEN_INT (ifalse),
735 if_info->x, 0, OPTAB_WIDEN);
744 if (target != if_info->x)
745 noce_emit_move_insn (if_info->x, target);
750 if (seq_contains_jump (seq))
753 emit_insns_before (seq, if_info->cond_earliest);
761 /* Convert "if (test) foo++" into "foo += (test != 0)", and
762 similarly for "foo--". */
765 noce_try_store_flag_inc (if_info)
766 struct noce_if_info *if_info;
769 int subtract, normalize;
775 /* Should be no `else' case to worry about. */
776 && if_info->b == if_info->x
777 && GET_CODE (if_info->a) == PLUS
778 && (XEXP (if_info->a, 1) == const1_rtx
779 || XEXP (if_info->a, 1) == constm1_rtx)
780 && rtx_equal_p (XEXP (if_info->a, 0), if_info->x)
781 && (reversed_comparison_code (if_info->cond, if_info->jump)
784 if (STORE_FLAG_VALUE == INTVAL (XEXP (if_info->a, 1)))
785 subtract = 0, normalize = 0;
786 else if (-STORE_FLAG_VALUE == INTVAL (XEXP (if_info->a, 1)))
787 subtract = 1, normalize = 0;
789 subtract = 0, normalize = INTVAL (XEXP (if_info->a, 1));
793 target = noce_emit_store_flag (if_info,
794 gen_reg_rtx (GET_MODE (if_info->x)),
798 target = expand_simple_binop (GET_MODE (if_info->x),
799 subtract ? MINUS : PLUS,
800 if_info->x, target, if_info->x,
804 if (target != if_info->x)
805 noce_emit_move_insn (if_info->x, target);
810 if (seq_contains_jump (seq))
813 emit_insns_before (seq, if_info->cond_earliest);
824 /* Convert "if (test) x = 0;" to "x &= -(test == 0);" */
827 noce_try_store_flag_mask (if_info)
828 struct noce_if_info *if_info;
836 || STORE_FLAG_VALUE == -1)
837 && ((if_info->a == const0_rtx
838 && rtx_equal_p (if_info->b, if_info->x))
839 || ((reversep = (reversed_comparison_code (if_info->cond,
842 && if_info->b == const0_rtx
843 && rtx_equal_p (if_info->a, if_info->x))))
846 target = noce_emit_store_flag (if_info,
847 gen_reg_rtx (GET_MODE (if_info->x)),
850 target = expand_simple_binop (GET_MODE (if_info->x), AND,
851 if_info->x, target, if_info->x, 0,
856 if (target != if_info->x)
857 noce_emit_move_insn (if_info->x, target);
862 if (seq_contains_jump (seq))
865 emit_insns_before (seq, if_info->cond_earliest);
876 /* Helper function for noce_try_cmove and noce_try_cmove_arith. */
879 noce_emit_cmove (if_info, x, code, cmp_a, cmp_b, vfalse, vtrue)
880 struct noce_if_info *if_info;
881 rtx x, cmp_a, cmp_b, vfalse, vtrue;
884 /* If earliest == jump, try to build the cmove insn directly.
885 This is helpful when combine has created some complex condition
886 (like for alpha's cmovlbs) that we can't hope to regenerate
887 through the normal interface. */
889 if (if_info->cond_earliest == if_info->jump)
893 tmp = gen_rtx_fmt_ee (code, GET_MODE (if_info->cond), cmp_a, cmp_b);
894 tmp = gen_rtx_IF_THEN_ELSE (GET_MODE (x), tmp, vtrue, vfalse);
895 tmp = gen_rtx_SET (VOIDmode, x, tmp);
898 tmp = emit_insn (tmp);
900 if (recog_memoized (tmp) >= 0)
912 /* Don't even try if the comparison operands are weird. */
913 if (! general_operand (cmp_a, GET_MODE (cmp_a))
914 || ! general_operand (cmp_b, GET_MODE (cmp_b)))
917 #if HAVE_conditional_move
918 return emit_conditional_move (x, code, cmp_a, cmp_b, VOIDmode,
919 vtrue, vfalse, GET_MODE (x),
920 (code == LTU || code == GEU
921 || code == LEU || code == GTU));
923 /* We'll never get here, as noce_process_if_block doesn't call the
924 functions involved. Ifdef code, however, should be discouraged
925 because it leads to typos in the code not selected. However,
926 emit_conditional_move won't exist either. */
931 /* Try only simple constants and registers here. More complex cases
932 are handled in noce_try_cmove_arith after noce_try_store_flag_arith
933 has had a go at it. */
936 noce_try_cmove (if_info)
937 struct noce_if_info *if_info;
942 if ((CONSTANT_P (if_info->a) || register_operand (if_info->a, VOIDmode))
943 && (CONSTANT_P (if_info->b) || register_operand (if_info->b, VOIDmode)))
947 code = GET_CODE (if_info->cond);
948 target = noce_emit_cmove (if_info, if_info->x, code,
949 XEXP (if_info->cond, 0),
950 XEXP (if_info->cond, 1),
951 if_info->a, if_info->b);
955 if (target != if_info->x)
956 noce_emit_move_insn (if_info->x, target);
960 emit_insns_before (seq, if_info->cond_earliest);
973 /* Try more complex cases involving conditional_move. */
976 noce_try_cmove_arith (if_info)
977 struct noce_if_info *if_info;
987 /* A conditional move from two memory sources is equivalent to a
988 conditional on their addresses followed by a load. Don't do this
989 early because it'll screw alias analysis. Note that we've
990 already checked for no side effects. */
991 if (! no_new_pseudos && cse_not_expected
992 && GET_CODE (a) == MEM && GET_CODE (b) == MEM
997 x = gen_reg_rtx (Pmode);
1001 /* ??? We could handle this if we knew that a load from A or B could
1002 not fault. This is also true if we've already loaded
1003 from the address along the path from ENTRY. */
1004 else if (may_trap_p (a) || may_trap_p (b))
1007 /* if (test) x = a + b; else x = c - d;
1014 code = GET_CODE (if_info->cond);
1015 insn_a = if_info->insn_a;
1016 insn_b = if_info->insn_b;
1018 /* Possibly rearrange operands to make things come out more natural. */
1019 if (reversed_comparison_code (if_info->cond, if_info->jump) != UNKNOWN)
1022 if (rtx_equal_p (b, x))
1024 else if (general_operand (b, GET_MODE (b)))
1029 code = reversed_comparison_code (if_info->cond, if_info->jump);
1030 tmp = a, a = b, b = tmp;
1031 tmp = insn_a, insn_a = insn_b, insn_b = tmp;
1037 /* If either operand is complex, load it into a register first.
1038 The best way to do this is to copy the original insn. In this
1039 way we preserve any clobbers etc that the insn may have had.
1040 This is of course not possible in the IS_MEM case. */
1041 if (! general_operand (a, GET_MODE (a)))
1046 goto end_seq_and_fail;
1050 tmp = gen_reg_rtx (GET_MODE (a));
1051 tmp = emit_insn (gen_rtx_SET (VOIDmode, tmp, a));
1054 goto end_seq_and_fail;
1057 a = gen_reg_rtx (GET_MODE (a));
1058 tmp = copy_rtx (insn_a);
1059 set = single_set (tmp);
1061 tmp = emit_insn (PATTERN (tmp));
1063 if (recog_memoized (tmp) < 0)
1064 goto end_seq_and_fail;
1066 if (! general_operand (b, GET_MODE (b)))
1071 goto end_seq_and_fail;
1075 tmp = gen_reg_rtx (GET_MODE (b));
1076 tmp = emit_insn (gen_rtx_SET (VOIDmode, tmp, b));
1079 goto end_seq_and_fail;
1082 b = gen_reg_rtx (GET_MODE (b));
1083 tmp = copy_rtx (insn_b);
1084 set = single_set (tmp);
1086 tmp = emit_insn (PATTERN (tmp));
1088 if (recog_memoized (tmp) < 0)
1089 goto end_seq_and_fail;
1092 target = noce_emit_cmove (if_info, x, code, XEXP (if_info->cond, 0),
1093 XEXP (if_info->cond, 1), a, b);
1096 goto end_seq_and_fail;
1098 /* If we're handling a memory for above, emit the load now. */
1101 tmp = gen_rtx_MEM (GET_MODE (if_info->x), target);
1103 /* Copy over flags as appropriate. */
1104 if (MEM_VOLATILE_P (if_info->a) || MEM_VOLATILE_P (if_info->b))
1105 MEM_VOLATILE_P (tmp) = 1;
1106 if (MEM_IN_STRUCT_P (if_info->a) && MEM_IN_STRUCT_P (if_info->b))
1107 MEM_IN_STRUCT_P (tmp) = 1;
1108 if (MEM_SCALAR_P (if_info->a) && MEM_SCALAR_P (if_info->b))
1109 MEM_SCALAR_P (tmp) = 1;
1110 if (MEM_ALIAS_SET (if_info->a) == MEM_ALIAS_SET (if_info->b))
1111 set_mem_alias_set (tmp, MEM_ALIAS_SET (if_info->a));
1113 noce_emit_move_insn (if_info->x, tmp);
1115 else if (target != x)
1116 noce_emit_move_insn (x, target);
1120 emit_insns_before (tmp, if_info->cond_earliest);
1128 /* For most cases, the simplified condition we found is the best
1129 choice, but this is not the case for the min/max/abs transforms.
1130 For these we wish to know that it is A or B in the condition. */
1133 noce_get_alt_condition (if_info, target, earliest)
1134 struct noce_if_info *if_info;
1138 rtx cond, set, insn;
1141 /* If target is already mentioned in the known condition, return it. */
1142 if (reg_mentioned_p (target, if_info->cond))
1144 *earliest = if_info->cond_earliest;
1145 return if_info->cond;
1148 set = pc_set (if_info->jump);
1149 cond = XEXP (SET_SRC (set), 0);
1151 = GET_CODE (XEXP (SET_SRC (set), 2)) == LABEL_REF
1152 && XEXP (XEXP (SET_SRC (set), 2), 0) == JUMP_LABEL (if_info->jump);
1154 /* If we're looking for a constant, try to make the conditional
1155 have that constant in it. There are two reasons why it may
1156 not have the constant we want:
1158 1. GCC may have needed to put the constant in a register, because
1159 the target can't compare directly against that constant. For
1160 this case, we look for a SET immediately before the comparison
1161 that puts a constant in that register.
1163 2. GCC may have canonicalized the conditional, for example
1164 replacing "if x < 4" with "if x <= 3". We can undo that (or
1165 make equivalent types of changes) to get the constants we need
1166 if they're off by one in the right direction. */
1168 if (GET_CODE (target) == CONST_INT)
1170 enum rtx_code code = GET_CODE (if_info->cond);
1171 rtx op_a = XEXP (if_info->cond, 0);
1172 rtx op_b = XEXP (if_info->cond, 1);
1175 /* First, look to see if we put a constant in a register. */
1176 prev_insn = PREV_INSN (if_info->cond_earliest);
1178 && INSN_P (prev_insn)
1179 && GET_CODE (PATTERN (prev_insn)) == SET)
1181 rtx src = find_reg_equal_equiv_note (prev_insn);
1183 src = SET_SRC (PATTERN (prev_insn));
1184 if (GET_CODE (src) == CONST_INT)
1186 if (rtx_equal_p (op_a, SET_DEST (PATTERN (prev_insn))))
1188 else if (rtx_equal_p (op_b, SET_DEST (PATTERN (prev_insn))))
1191 if (GET_CODE (op_a) == CONST_INT)
1196 code = swap_condition (code);
1201 /* Now, look to see if we can get the right constant by
1202 adjusting the conditional. */
1203 if (GET_CODE (op_b) == CONST_INT)
1205 HOST_WIDE_INT desired_val = INTVAL (target);
1206 HOST_WIDE_INT actual_val = INTVAL (op_b);
1211 if (actual_val == desired_val + 1)
1214 op_b = GEN_INT (desired_val);
1218 if (actual_val == desired_val - 1)
1221 op_b = GEN_INT (desired_val);
1225 if (actual_val == desired_val - 1)
1228 op_b = GEN_INT (desired_val);
1232 if (actual_val == desired_val + 1)
1235 op_b = GEN_INT (desired_val);
1243 /* If we made any changes, generate a new conditional that is
1244 equivalent to what we started with, but has the right
1246 if (code != GET_CODE (if_info->cond)
1247 || op_a != XEXP (if_info->cond, 0)
1248 || op_b != XEXP (if_info->cond, 1))
1250 cond = gen_rtx_fmt_ee (code, GET_MODE (cond), op_a, op_b);
1251 *earliest = if_info->cond_earliest;
1256 cond = canonicalize_condition (if_info->jump, cond, reverse,
1258 if (! cond || ! reg_mentioned_p (target, cond))
1261 /* We almost certainly searched back to a different place.
1262 Need to re-verify correct lifetimes. */
1264 /* X may not be mentioned in the range (cond_earliest, jump]. */
1265 for (insn = if_info->jump; insn != *earliest; insn = PREV_INSN (insn))
1266 if (INSN_P (insn) && reg_mentioned_p (if_info->x, insn))
1269 /* A and B may not be modified in the range [cond_earliest, jump). */
1270 for (insn = *earliest; insn != if_info->jump; insn = NEXT_INSN (insn))
1272 && (modified_in_p (if_info->a, insn)
1273 || modified_in_p (if_info->b, insn)))
1279 /* Convert "if (a < b) x = a; else x = b;" to "x = min(a, b);", etc. */
1282 noce_try_minmax (if_info)
1283 struct noce_if_info *if_info;
1285 rtx cond, earliest, target, seq;
1286 enum rtx_code code, op;
1289 /* ??? Can't guarantee that expand_binop won't create pseudos. */
1293 /* ??? Reject FP modes since we don't know how 0 vs -0 or NaNs
1294 will be resolved with an SMIN/SMAX. It wouldn't be too hard
1295 to get the target to tell us... */
1296 if (FLOAT_MODE_P (GET_MODE (if_info->x))
1297 && TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
1298 && ! flag_unsafe_math_optimizations)
1301 cond = noce_get_alt_condition (if_info, if_info->a, &earliest);
1305 /* Verify the condition is of the form we expect, and canonicalize
1306 the comparison code. */
1307 code = GET_CODE (cond);
1308 if (rtx_equal_p (XEXP (cond, 0), if_info->a))
1310 if (! rtx_equal_p (XEXP (cond, 1), if_info->b))
1313 else if (rtx_equal_p (XEXP (cond, 1), if_info->a))
1315 if (! rtx_equal_p (XEXP (cond, 0), if_info->b))
1317 code = swap_condition (code);
1322 /* Determine what sort of operation this is. Note that the code is for
1323 a taken branch, so the code->operation mapping appears backwards. */
1356 target = expand_simple_binop (GET_MODE (if_info->x), op,
1357 if_info->a, if_info->b,
1358 if_info->x, unsignedp, OPTAB_WIDEN);
1364 if (target != if_info->x)
1365 noce_emit_move_insn (if_info->x, target);
1370 if (seq_contains_jump (seq))
1373 emit_insns_before (seq, earliest);
1374 if_info->cond = cond;
1375 if_info->cond_earliest = earliest;
1380 /* Convert "if (a < 0) x = -a; else x = a;" to "x = abs(a);", etc. */
1383 noce_try_abs (if_info)
1384 struct noce_if_info *if_info;
1386 rtx cond, earliest, target, seq, a, b, c;
1389 /* ??? Can't guarantee that expand_binop won't create pseudos. */
1393 /* Recognize A and B as constituting an ABS or NABS. */
1396 if (GET_CODE (a) == NEG && rtx_equal_p (XEXP (a, 0), b))
1398 else if (GET_CODE (b) == NEG && rtx_equal_p (XEXP (b, 0), a))
1400 c = a; a = b; b = c;
1406 cond = noce_get_alt_condition (if_info, b, &earliest);
1410 /* Verify the condition is of the form we expect. */
1411 if (rtx_equal_p (XEXP (cond, 0), b))
1413 else if (rtx_equal_p (XEXP (cond, 1), b))
1418 /* Verify that C is zero. Search backward through the block for
1419 a REG_EQUAL note if necessary. */
1422 rtx insn, note = NULL;
1423 for (insn = earliest;
1424 insn != if_info->test_bb->head;
1425 insn = PREV_INSN (insn))
1427 && ((note = find_reg_note (insn, REG_EQUAL, c))
1428 || (note = find_reg_note (insn, REG_EQUIV, c))))
1434 if (GET_CODE (c) == MEM
1435 && GET_CODE (XEXP (c, 0)) == SYMBOL_REF
1436 && CONSTANT_POOL_ADDRESS_P (XEXP (c, 0)))
1437 c = get_pool_constant (XEXP (c, 0));
1439 /* Work around funny ideas get_condition has wrt canonicalization.
1440 Note that these rtx constants are known to be CONST_INT, and
1441 therefore imply integer comparisons. */
1442 if (c == constm1_rtx && GET_CODE (cond) == GT)
1444 else if (c == const1_rtx && GET_CODE (cond) == LT)
1446 else if (c != CONST0_RTX (GET_MODE (b)))
1449 /* Determine what sort of operation this is. */
1450 switch (GET_CODE (cond))
1469 target = expand_simple_unop (GET_MODE (if_info->x), ABS, b, if_info->x, 0);
1471 /* ??? It's a quandry whether cmove would be better here, especially
1472 for integers. Perhaps combine will clean things up. */
1473 if (target && negate)
1474 target = expand_simple_unop (GET_MODE (target), NEG, target, if_info->x, 0);
1482 if (target != if_info->x)
1483 noce_emit_move_insn (if_info->x, target);
1488 if (seq_contains_jump (seq))
1491 emit_insns_before (seq, earliest);
1492 if_info->cond = cond;
1493 if_info->cond_earliest = earliest;
1498 /* Look for the condition for the jump first. We'd prefer to avoid
1499 get_condition if we can -- it tries to look back for the contents
1500 of an original compare. On targets that use normal integers for
1501 comparisons, e.g. alpha, this is wasteful. */
1504 noce_get_condition (jump, earliest)
1511 /* If the condition variable is a register and is MODE_INT, accept it.
1512 Otherwise, fall back on get_condition. */
1514 if (! any_condjump_p (jump))
1517 set = pc_set (jump);
1519 cond = XEXP (SET_SRC (set), 0);
1520 if (GET_CODE (XEXP (cond, 0)) == REG
1521 && GET_MODE_CLASS (GET_MODE (XEXP (cond, 0))) == MODE_INT)
1525 /* If this branches to JUMP_LABEL when the condition is false,
1526 reverse the condition. */
1527 if (GET_CODE (XEXP (SET_SRC (set), 2)) == LABEL_REF
1528 && XEXP (XEXP (SET_SRC (set), 2), 0) == JUMP_LABEL (jump))
1529 cond = gen_rtx_fmt_ee (reverse_condition (GET_CODE (cond)),
1530 GET_MODE (cond), XEXP (cond, 0),
1534 cond = get_condition (jump, earliest);
1539 /* Return true if OP is ok for if-then-else processing. */
1542 noce_operand_ok (op)
1545 /* We special-case memories, so handle any of them with
1546 no address side effects. */
1547 if (GET_CODE (op) == MEM)
1548 return ! side_effects_p (XEXP (op, 0));
1550 if (side_effects_p (op))
1553 /* ??? Unfortuantely may_trap_p can't look at flag_trapping_math, due to
1554 being linked into the genfoo programs. This is probably a mistake.
1555 With finite operands, most fp operations don't trap. */
1556 if (!flag_trapping_math && FLOAT_MODE_P (GET_MODE (op)))
1557 switch (GET_CODE (op))
1563 /* ??? This is kinda lame -- almost every target will have forced
1564 the constant into a register first. But given the expense of
1565 division, this is probably for the best. */
1566 return (CONSTANT_P (XEXP (op, 1))
1567 && XEXP (op, 1) != CONST0_RTX (GET_MODE (op))
1568 && ! may_trap_p (XEXP (op, 0)));
1571 switch (GET_RTX_CLASS (GET_CODE (op)))
1574 return ! may_trap_p (XEXP (op, 0));
1577 return ! may_trap_p (XEXP (op, 0)) && ! may_trap_p (XEXP (op, 1));
1582 return ! may_trap_p (op);
1585 /* Given a simple IF-THEN or IF-THEN-ELSE block, attempt to convert it
1586 without using conditional execution. Return TRUE if we were
1587 successful at converting the the block. */
1590 noce_process_if_block (test_bb, then_bb, else_bb, join_bb)
1591 basic_block test_bb; /* Basic block test is in */
1592 basic_block then_bb; /* Basic block for THEN block */
1593 basic_block else_bb; /* Basic block for ELSE block */
1594 basic_block join_bb; /* Basic block the join label is in */
1596 /* We're looking for patterns of the form
1598 (1) if (...) x = a; else x = b;
1599 (2) x = b; if (...) x = a;
1600 (3) if (...) x = a; // as if with an initial x = x.
1602 The later patterns require jumps to be more expensive.
1604 ??? For future expansion, look for multiple X in such patterns. */
1606 struct noce_if_info if_info;
1609 rtx orig_x, x, a, b;
1610 rtx jump, cond, insn;
1612 /* If this is not a standard conditional jump, we can't parse it. */
1613 jump = test_bb->end;
1614 cond = noce_get_condition (jump, &if_info.cond_earliest);
1618 /* If the conditional jump is more than just a conditional jump,
1619 then we can not do if-conversion on this block. */
1620 if (! onlyjump_p (jump))
1623 /* We must be comparing objects whose modes imply the size. */
1624 if (GET_MODE (XEXP (cond, 0)) == BLKmode)
1627 /* Look for one of the potential sets. */
1628 insn_a = first_active_insn (then_bb);
1630 || ! last_active_insn_p (then_bb, insn_a)
1631 || (set_a = single_set (insn_a)) == NULL_RTX)
1634 x = SET_DEST (set_a);
1635 a = SET_SRC (set_a);
1637 /* Look for the other potential set. Make sure we've got equivalent
1639 /* ??? This is overconservative. Storing to two different mems is
1640 as easy as conditionally computing the address. Storing to a
1641 single mem merely requires a scratch memory to use as one of the
1642 destination addresses; often the memory immediately below the
1643 stack pointer is available for this. */
1647 insn_b = first_active_insn (else_bb);
1649 || ! last_active_insn_p (else_bb, insn_b)
1650 || (set_b = single_set (insn_b)) == NULL_RTX
1651 || ! rtx_equal_p (x, SET_DEST (set_b)))
1656 insn_b = prev_nonnote_insn (if_info.cond_earliest);
1658 || GET_CODE (insn_b) != INSN
1659 || (set_b = single_set (insn_b)) == NULL_RTX
1660 || ! rtx_equal_p (x, SET_DEST (set_b))
1661 || reg_mentioned_p (x, cond)
1662 || reg_mentioned_p (x, a)
1663 || reg_mentioned_p (x, SET_SRC (set_b)))
1664 insn_b = set_b = NULL_RTX;
1666 b = (set_b ? SET_SRC (set_b) : x);
1668 /* X may not be mentioned in the range (cond_earliest, jump]. */
1669 for (insn = jump; insn != if_info.cond_earliest; insn = PREV_INSN (insn))
1670 if (INSN_P (insn) && reg_mentioned_p (x, insn))
1673 /* A and B may not be modified in the range [cond_earliest, jump). */
1674 for (insn = if_info.cond_earliest; insn != jump; insn = NEXT_INSN (insn))
1676 && (modified_in_p (a, insn) || modified_in_p (b, insn)))
1679 /* Only operate on register destinations, and even then avoid extending
1680 the lifetime of hard registers on small register class machines. */
1682 if (GET_CODE (x) != REG
1683 || (SMALL_REGISTER_CLASSES
1684 && REGNO (x) < FIRST_PSEUDO_REGISTER))
1688 x = gen_reg_rtx (GET_MODE (GET_CODE (x) == STRICT_LOW_PART
1689 ? XEXP (x, 0) : x));
1692 /* Don't operate on sources that may trap or are volatile. */
1693 if (! noce_operand_ok (a) || ! noce_operand_ok (b))
1696 /* Set up the info block for our subroutines. */
1697 if_info.test_bb = test_bb;
1698 if_info.cond = cond;
1699 if_info.jump = jump;
1700 if_info.insn_a = insn_a;
1701 if_info.insn_b = insn_b;
1706 /* Try optimizations in some approximation of a useful order. */
1707 /* ??? Should first look to see if X is live incoming at all. If it
1708 isn't, we don't need anything but an unconditional set. */
1710 /* Look and see if A and B are really the same. Avoid creating silly
1711 cmove constructs that no one will fix up later. */
1712 if (rtx_equal_p (a, b))
1714 /* If we have an INSN_B, we don't have to create any new rtl. Just
1715 move the instruction that we already have. If we don't have an
1716 INSN_B, that means that A == X, and we've got a noop move. In
1717 that case don't do anything and let the code below delete INSN_A. */
1718 if (insn_b && else_bb)
1722 if (else_bb && insn_b == else_bb->end)
1723 else_bb->end = PREV_INSN (insn_b);
1724 reorder_insns (insn_b, insn_b, PREV_INSN (if_info.cond_earliest));
1726 /* If there was a REG_EQUAL note, delete it since it may have been
1727 true due to this insn being after a jump. */
1728 if ((note = find_reg_note (insn_b, REG_EQUAL, NULL_RTX)) != 0)
1729 remove_note (insn_b, note);
1733 /* If we have "x = b; if (...) x = a;", and x has side-effects, then
1734 x must be executed twice. */
1735 else if (insn_b && side_effects_p (orig_x))
1742 if (noce_try_store_flag (&if_info))
1744 if (noce_try_minmax (&if_info))
1746 if (noce_try_abs (&if_info))
1748 if (HAVE_conditional_move
1749 && noce_try_cmove (&if_info))
1751 if (! HAVE_conditional_execution)
1753 if (noce_try_store_flag_constants (&if_info))
1755 if (noce_try_store_flag_inc (&if_info))
1757 if (noce_try_store_flag_mask (&if_info))
1759 if (HAVE_conditional_move
1760 && noce_try_cmove_arith (&if_info))
1767 /* The original sets may now be killed. */
1768 delete_insn (insn_a);
1770 /* Several special cases here: First, we may have reused insn_b above,
1771 in which case insn_b is now NULL. Second, we want to delete insn_b
1772 if it came from the ELSE block, because follows the now correct
1773 write that appears in the TEST block. However, if we got insn_b from
1774 the TEST block, it may in fact be loading data needed for the comparison.
1775 We'll let life_analysis remove the insn if it's really dead. */
1776 if (insn_b && else_bb)
1777 delete_insn (insn_b);
1779 /* The new insns will have been inserted before cond_earliest. We should
1780 be able to remove the jump with impunity, but the condition itself may
1781 have been modified by gcse to be shared across basic blocks. */
1784 /* If we used a temporary, fix it up now. */
1788 noce_emit_move_insn (orig_x, x);
1789 insn_b = gen_sequence ();
1792 emit_insn_after (insn_b, test_bb->end);
1795 /* Merge the blocks! */
1796 merge_if_block (test_bb, then_bb, else_bb, join_bb);
1801 /* Attempt to convert an IF-THEN or IF-THEN-ELSE block into
1802 straight line code. Return true if successful. */
1805 process_if_block (test_bb, then_bb, else_bb, join_bb)
1806 basic_block test_bb; /* Basic block test is in */
1807 basic_block then_bb; /* Basic block for THEN block */
1808 basic_block else_bb; /* Basic block for ELSE block */
1809 basic_block join_bb; /* Basic block the join label is in */
1811 if (! reload_completed
1812 && noce_process_if_block (test_bb, then_bb, else_bb, join_bb))
1815 if (HAVE_conditional_execution
1817 && cond_exec_process_if_block (test_bb, then_bb, else_bb, join_bb))
1823 /* Merge the blocks and mark for local life update. */
1826 merge_if_block (test_bb, then_bb, else_bb, join_bb)
1827 basic_block test_bb; /* Basic block test is in */
1828 basic_block then_bb; /* Basic block for THEN block */
1829 basic_block else_bb; /* Basic block for ELSE block */
1830 basic_block join_bb; /* Basic block the join label is in */
1832 basic_block combo_bb;
1834 /* All block merging is done into the lower block numbers. */
1838 /* First merge TEST block into THEN block. This is a no-brainer since
1839 the THEN block did not have a code label to begin with. */
1842 COPY_REG_SET (combo_bb->global_live_at_end, then_bb->global_live_at_end);
1843 merge_blocks_nomove (combo_bb, then_bb);
1844 num_removed_blocks++;
1846 /* The ELSE block, if it existed, had a label. That label count
1847 will almost always be zero, but odd things can happen when labels
1848 get their addresses taken. */
1851 merge_blocks_nomove (combo_bb, else_bb);
1852 num_removed_blocks++;
1855 /* If there was no join block reported, that means it was not adjacent
1856 to the others, and so we cannot merge them. */
1860 /* The outgoing edge for the current COMBO block should already
1861 be correct. Verify this. */
1862 if (combo_bb->succ == NULL_EDGE)
1865 /* There should still be a branch at the end of the THEN or ELSE
1866 blocks taking us to our final destination. */
1867 if (GET_CODE (combo_bb->end) != JUMP_INSN)
1871 /* The JOIN block may have had quite a number of other predecessors too.
1872 Since we've already merged the TEST, THEN and ELSE blocks, we should
1873 have only one remaining edge from our if-then-else diamond. If there
1874 is more than one remaining edge, it must come from elsewhere. There
1875 may be zero incoming edges if the THEN block didn't actually join
1876 back up (as with a call to abort). */
1877 else if ((join_bb->pred == NULL
1878 || join_bb->pred->pred_next == NULL)
1879 && join_bb != EXIT_BLOCK_PTR)
1881 /* We can merge the JOIN. */
1883 COPY_REG_SET (combo_bb->global_live_at_end,
1884 join_bb->global_live_at_end);
1885 merge_blocks_nomove (combo_bb, join_bb);
1886 num_removed_blocks++;
1890 /* We cannot merge the JOIN. */
1892 /* The outgoing edge for the current COMBO block should already
1893 be correct. Verify this. */
1894 if (combo_bb->succ->succ_next != NULL_EDGE
1895 || combo_bb->succ->dest != join_bb)
1898 /* Remove the jump and cruft from the end of the COMBO block. */
1899 if (join_bb != EXIT_BLOCK_PTR)
1900 tidy_fallthru_edge (combo_bb->succ, combo_bb, join_bb);
1903 /* Make sure we update life info properly. */
1904 SET_UPDATE_LIFE (combo_bb);
1906 num_updated_if_blocks++;
1909 /* Find a block ending in a simple IF condition. Return TRUE if
1910 we were able to transform it in some way. */
1913 find_if_header (test_bb)
1914 basic_block test_bb;
1919 /* The kind of block we're looking for has exactly two successors. */
1920 if ((then_edge = test_bb->succ) == NULL_EDGE
1921 || (else_edge = then_edge->succ_next) == NULL_EDGE
1922 || else_edge->succ_next != NULL_EDGE)
1925 /* Neither edge should be abnormal. */
1926 if ((then_edge->flags & EDGE_COMPLEX)
1927 || (else_edge->flags & EDGE_COMPLEX))
1930 /* The THEN edge is canonically the one that falls through. */
1931 if (then_edge->flags & EDGE_FALLTHRU)
1933 else if (else_edge->flags & EDGE_FALLTHRU)
1936 else_edge = then_edge;
1940 /* Otherwise this must be a multiway branch of some sort. */
1943 if (find_if_block (test_bb, then_edge, else_edge))
1945 if (HAVE_trap && HAVE_conditional_trap
1946 && find_cond_trap (test_bb, then_edge, else_edge))
1949 && (! HAVE_conditional_execution || reload_completed))
1951 if (find_if_case_1 (test_bb, then_edge, else_edge))
1953 if (find_if_case_2 (test_bb, then_edge, else_edge))
1961 fprintf (rtl_dump_file, "Conversion succeeded.\n");
1965 /* Determine if a given basic block heads a simple IF-THEN or IF-THEN-ELSE
1966 block. If so, we'll try to convert the insns to not require the branch.
1967 Return TRUE if we were successful at converting the the block. */
1970 find_if_block (test_bb, then_edge, else_edge)
1971 basic_block test_bb;
1972 edge then_edge, else_edge;
1974 basic_block then_bb = then_edge->dest;
1975 basic_block else_bb = else_edge->dest;
1976 basic_block join_bb = NULL_BLOCK;
1977 edge then_succ = then_bb->succ;
1978 edge else_succ = else_bb->succ;
1981 /* The THEN block of an IF-THEN combo must have exactly one predecessor. */
1982 if (then_bb->pred->pred_next != NULL_EDGE)
1985 /* The THEN block of an IF-THEN combo must have zero or one successors. */
1986 if (then_succ != NULL_EDGE
1987 && (then_succ->succ_next != NULL_EDGE
1988 || (then_succ->flags & EDGE_COMPLEX)))
1991 /* If the THEN block has no successors, conditional execution can still
1992 make a conditional call. Don't do this unless the ELSE block has
1993 only one incoming edge -- the CFG manipulation is too ugly otherwise.
1994 Check for the last insn of the THEN block being an indirect jump, which
1995 is listed as not having any successors, but confuses the rest of the CE
1996 code processing. XXX we should fix this in the future. */
1997 if (then_succ == NULL)
1999 if (else_bb->pred->pred_next == NULL_EDGE)
2001 rtx last_insn = then_bb->end;
2004 && GET_CODE (last_insn) == NOTE
2005 && last_insn != then_bb->head)
2006 last_insn = PREV_INSN (last_insn);
2009 && GET_CODE (last_insn) == JUMP_INSN
2010 && ! simplejump_p (last_insn))
2014 else_bb = NULL_BLOCK;
2020 /* If the THEN block's successor is the other edge out of the TEST block,
2021 then we have an IF-THEN combo without an ELSE. */
2022 else if (then_succ->dest == else_bb)
2025 else_bb = NULL_BLOCK;
2028 /* If the THEN and ELSE block meet in a subsequent block, and the ELSE
2029 has exactly one predecessor and one successor, and the outgoing edge
2030 is not complex, then we have an IF-THEN-ELSE combo. */
2031 else if (else_succ != NULL_EDGE
2032 && then_succ->dest == else_succ->dest
2033 && else_bb->pred->pred_next == NULL_EDGE
2034 && else_succ->succ_next == NULL_EDGE
2035 && ! (else_succ->flags & EDGE_COMPLEX))
2036 join_bb = else_succ->dest;
2038 /* Otherwise it is not an IF-THEN or IF-THEN-ELSE combination. */
2042 num_possible_if_blocks++;
2047 fprintf (rtl_dump_file,
2048 "\nIF-THEN-ELSE block found, start %d, then %d, else %d, join %d\n",
2049 test_bb->index, then_bb->index, else_bb->index,
2052 fprintf (rtl_dump_file,
2053 "\nIF-THEN block found, start %d, then %d, join %d\n",
2054 test_bb->index, then_bb->index, join_bb->index);
2057 /* Make sure IF, THEN, and ELSE, blocks are adjacent. Actually, we
2058 get the first condition for free, since we've already asserted that
2059 there's a fallthru edge from IF to THEN. */
2060 /* ??? As an enhancement, move the ELSE block. Have to deal with
2061 BLOCK notes, if by no other means than aborting the merge if they
2062 exist. Sticky enough I don't want to think about it now. */
2063 next_index = then_bb->index;
2064 if (else_bb && ++next_index != else_bb->index)
2066 if (++next_index != join_bb->index && join_bb->index != EXIT_BLOCK)
2074 /* Do the real work. */
2075 return process_if_block (test_bb, then_bb, else_bb, join_bb);
2078 /* Convert a branch over a trap, or a branch to a trap,
2079 into a conditional trap. */
2082 find_cond_trap (test_bb, then_edge, else_edge)
2083 basic_block test_bb;
2084 edge then_edge, else_edge;
2086 basic_block then_bb, else_bb, join_bb, trap_bb;
2087 rtx trap, jump, cond, cond_earliest, seq;
2090 then_bb = then_edge->dest;
2091 else_bb = else_edge->dest;
2094 /* Locate the block with the trap instruction. */
2095 /* ??? While we look for no successors, we really ought to allow
2096 EH successors. Need to fix merge_if_block for that to work. */
2097 /* ??? We can't currently handle merging the blocks if they are not
2098 already adjacent. Prevent losage in merge_if_block by detecting
2100 if (then_bb->succ == NULL)
2103 if (else_bb->index != then_bb->index + 1)
2108 else if (else_bb->succ == NULL)
2111 if (else_bb->index != then_bb->index + 1)
2113 else if (then_bb->succ
2114 && ! then_bb->succ->succ_next
2115 && ! (then_bb->succ->flags & EDGE_COMPLEX)
2116 && then_bb->succ->dest->index == else_bb->index + 1)
2117 join_bb = then_bb->succ->dest;
2122 /* Don't confuse a conditional return with something we want to
2124 if (trap_bb == EXIT_BLOCK_PTR)
2127 /* The only instruction in the THEN block must be the trap. */
2128 trap = first_active_insn (trap_bb);
2129 if (! (trap == trap_bb->end
2130 && GET_CODE (PATTERN (trap)) == TRAP_IF
2131 && TRAP_CONDITION (PATTERN (trap)) == const_true_rtx))
2136 if (trap_bb == then_bb)
2137 fprintf (rtl_dump_file,
2138 "\nTRAP-IF block found, start %d, trap %d",
2139 test_bb->index, then_bb->index);
2141 fprintf (rtl_dump_file,
2142 "\nTRAP-IF block found, start %d, then %d, trap %d",
2143 test_bb->index, then_bb->index, trap_bb->index);
2145 fprintf (rtl_dump_file, ", join %d\n", join_bb->index);
2147 fputc ('\n', rtl_dump_file);
2150 /* If this is not a standard conditional jump, we can't parse it. */
2151 jump = test_bb->end;
2152 cond = noce_get_condition (jump, &cond_earliest);
2156 /* If the conditional jump is more than just a conditional jump,
2157 then we can not do if-conversion on this block. */
2158 if (! onlyjump_p (jump))
2161 /* We must be comparing objects whose modes imply the size. */
2162 if (GET_MODE (XEXP (cond, 0)) == BLKmode)
2165 /* Reverse the comparison code, if necessary. */
2166 code = GET_CODE (cond);
2167 if (then_bb == trap_bb)
2169 code = reversed_comparison_code (cond, jump);
2170 if (code == UNKNOWN)
2174 /* Attempt to generate the conditional trap. */
2175 seq = gen_cond_trap (code, XEXP (cond, 0), XEXP (cond, 1),
2176 TRAP_CODE (PATTERN (trap)));
2180 /* Emit the new insns before cond_earliest; delete the old jump
2183 emit_insn_before (seq, cond_earliest);
2189 /* Merge the blocks! */
2190 if (trap_bb != then_bb && ! else_bb)
2192 flow_delete_block (trap_bb);
2193 num_removed_blocks++;
2195 merge_if_block (test_bb, then_bb, else_bb, join_bb);
2200 /* Look for IF-THEN-ELSE cases in which one of THEN or ELSE is
2201 transformable, but not necessarily the other. There need be no
2204 Return TRUE if we were successful at converting the the block.
2206 Cases we'd like to look at:
2209 if (test) goto over; // x not live
2217 if (! test) goto label;
2220 if (test) goto E; // x not live
2234 (3) // This one's really only interesting for targets that can do
2235 // multiway branching, e.g. IA-64 BBB bundles. For other targets
2236 // it results in multiple branches on a cache line, which often
2237 // does not sit well with predictors.
2239 if (test1) goto E; // predicted not taken
2255 (A) Don't do (2) if the branch is predicted against the block we're
2256 eliminating. Do it anyway if we can eliminate a branch; this requires
2257 that the sole successor of the eliminated block postdominate the other
2260 (B) With CE, on (3) we can steal from both sides of the if, creating
2269 Again, this is most useful if J postdominates.
2271 (C) CE substitutes for helpful life information.
2273 (D) These heuristics need a lot of work. */
2275 /* Tests for case 1 above. */
2278 find_if_case_1 (test_bb, then_edge, else_edge)
2279 basic_block test_bb;
2280 edge then_edge, else_edge;
2282 basic_block then_bb = then_edge->dest;
2283 basic_block else_bb = else_edge->dest, new_bb;
2284 edge then_succ = then_bb->succ;
2286 /* THEN has one successor. */
2287 if (!then_succ || then_succ->succ_next != NULL)
2290 /* THEN does not fall through, but is not strange either. */
2291 if (then_succ->flags & (EDGE_COMPLEX | EDGE_FALLTHRU))
2294 /* THEN has one predecessor. */
2295 if (then_bb->pred->pred_next != NULL)
2298 /* THEN must do something. */
2299 if (forwarder_block_p (then_bb))
2302 num_possible_if_blocks++;
2304 fprintf (rtl_dump_file,
2305 "\nIF-CASE-1 found, start %d, then %d\n",
2306 test_bb->index, then_bb->index);
2308 /* THEN is small. */
2309 if (count_bb_insns (then_bb) > BRANCH_COST)
2312 /* Registers set are dead, or are predicable. */
2313 if (! dead_or_predicable (test_bb, then_bb, else_bb,
2314 then_bb->succ->dest, 1))
2317 /* Conversion went ok, including moving the insns and fixing up the
2318 jump. Adjust the CFG to match. */
2320 SET_UPDATE_LIFE (test_bb);
2321 bitmap_operation (test_bb->global_live_at_end,
2322 else_bb->global_live_at_start,
2323 then_bb->global_live_at_end, BITMAP_IOR);
2325 new_bb = redirect_edge_and_branch_force (FALLTHRU_EDGE (test_bb), else_bb);
2326 /* Make rest of code believe that the newly created block is the THEN_BB
2327 block we are going to remove. */
2330 new_bb->aux = then_bb->aux;
2331 SET_UPDATE_LIFE (then_bb);
2333 flow_delete_block (then_bb);
2334 /* We've possibly created jump to next insn, cleanup_cfg will solve that
2337 num_removed_blocks++;
2338 num_updated_if_blocks++;
2343 /* Test for case 2 above. */
2346 find_if_case_2 (test_bb, then_edge, else_edge)
2347 basic_block test_bb;
2348 edge then_edge, else_edge;
2350 basic_block then_bb = then_edge->dest;
2351 basic_block else_bb = else_edge->dest;
2352 edge else_succ = else_bb->succ;
2355 /* ELSE has one successor. */
2356 if (!else_succ || else_succ->succ_next != NULL)
2359 /* ELSE outgoing edge is not complex. */
2360 if (else_succ->flags & EDGE_COMPLEX)
2363 /* ELSE has one predecessor. */
2364 if (else_bb->pred->pred_next != NULL)
2367 /* THEN is not EXIT. */
2368 if (then_bb->index < 0)
2371 /* ELSE is predicted or SUCC(ELSE) postdominates THEN. */
2372 note = find_reg_note (test_bb->end, REG_BR_PROB, NULL_RTX);
2373 if (note && INTVAL (XEXP (note, 0)) >= REG_BR_PROB_BASE / 2)
2375 else if (else_succ->dest->index < 0
2376 || TEST_BIT (post_dominators[ORIG_INDEX (then_bb)],
2377 ORIG_INDEX (else_succ->dest)))
2382 num_possible_if_blocks++;
2384 fprintf (rtl_dump_file,
2385 "\nIF-CASE-2 found, start %d, else %d\n",
2386 test_bb->index, else_bb->index);
2388 /* ELSE is small. */
2389 if (count_bb_insns (then_bb) > BRANCH_COST)
2392 /* Registers set are dead, or are predicable. */
2393 if (! dead_or_predicable (test_bb, else_bb, then_bb, else_succ->dest, 0))
2396 /* Conversion went ok, including moving the insns and fixing up the
2397 jump. Adjust the CFG to match. */
2399 SET_UPDATE_LIFE (test_bb);
2400 bitmap_operation (test_bb->global_live_at_end,
2401 then_bb->global_live_at_start,
2402 else_bb->global_live_at_end, BITMAP_IOR);
2404 flow_delete_block (else_bb);
2406 num_removed_blocks++;
2407 num_updated_if_blocks++;
2409 /* ??? We may now fallthru from one of THEN's successors into a join
2410 block. Rerun cleanup_cfg? Examine things manually? Wait? */
2415 /* A subroutine of dead_or_predicable called through for_each_rtx.
2416 Return 1 if a memory is found. */
2419 find_memory (px, data)
2421 void *data ATTRIBUTE_UNUSED;
2423 return GET_CODE (*px) == MEM;
2426 /* Used by the code above to perform the actual rtl transformations.
2427 Return TRUE if successful.
2429 TEST_BB is the block containing the conditional branch. MERGE_BB
2430 is the block containing the code to manipulate. NEW_DEST is the
2431 label TEST_BB should be branching to after the conversion.
2432 REVERSEP is true if the sense of the branch should be reversed. */
2435 dead_or_predicable (test_bb, merge_bb, other_bb, new_dest, reversep)
2436 basic_block test_bb, merge_bb, other_bb;
2437 basic_block new_dest;
2440 rtx head, end, jump, earliest, old_dest, new_label;
2442 jump = test_bb->end;
2444 /* Find the extent of the real code in the merge block. */
2445 head = merge_bb->head;
2446 end = merge_bb->end;
2448 if (GET_CODE (head) == CODE_LABEL)
2449 head = NEXT_INSN (head);
2450 if (GET_CODE (head) == NOTE)
2454 head = end = NULL_RTX;
2457 head = NEXT_INSN (head);
2460 if (GET_CODE (end) == JUMP_INSN)
2464 head = end = NULL_RTX;
2467 end = PREV_INSN (end);
2470 /* Disable handling dead code by conditional execution if the machine needs
2471 to do anything funny with the tests, etc. */
2472 #ifndef IFCVT_MODIFY_TESTS
2473 if (HAVE_conditional_execution)
2475 /* In the conditional execution case, we have things easy. We know
2476 the condition is reversable. We don't have to check life info,
2477 becase we're going to conditionally execute the code anyway.
2478 All that's left is making sure the insns involved can actually
2483 cond = cond_exec_get_condition (jump);
2487 prob_val = find_reg_note (jump, REG_BR_PROB, NULL_RTX);
2489 prob_val = XEXP (prob_val, 0);
2493 enum rtx_code rev = reversed_comparison_code (cond, jump);
2496 cond = gen_rtx_fmt_ee (rev, GET_MODE (cond), XEXP (cond, 0),
2499 prob_val = GEN_INT (REG_BR_PROB_BASE - INTVAL (prob_val));
2502 if (! cond_exec_process_insns (head, end, cond, prob_val, 0))
2510 /* In the non-conditional execution case, we have to verify that there
2511 are no trapping operations, no calls, no references to memory, and
2512 that any registers modified are dead at the branch site. */
2514 rtx insn, cond, prev;
2515 regset_head merge_set_head, tmp_head, test_live_head, test_set_head;
2516 regset merge_set, tmp, test_live, test_set;
2517 struct propagate_block_info *pbi;
2520 /* Check for no calls or trapping operations. */
2521 for (insn = head; ; insn = NEXT_INSN (insn))
2523 if (GET_CODE (insn) == CALL_INSN)
2527 if (may_trap_p (PATTERN (insn)))
2530 /* ??? Even non-trapping memories such as stack frame
2531 references must be avoided. For stores, we collect
2532 no lifetime info; for reads, we'd have to assert
2533 true_dependance false against every store in the
2535 if (for_each_rtx (&PATTERN (insn), find_memory, NULL))
2542 if (! any_condjump_p (jump))
2545 /* Find the extent of the conditional. */
2546 cond = noce_get_condition (jump, &earliest);
2551 MERGE_SET = set of registers set in MERGE_BB
2552 TEST_LIVE = set of registers live at EARLIEST
2553 TEST_SET = set of registers set between EARLIEST and the
2554 end of the block. */
2556 tmp = INITIALIZE_REG_SET (tmp_head);
2557 merge_set = INITIALIZE_REG_SET (merge_set_head);
2558 test_live = INITIALIZE_REG_SET (test_live_head);
2559 test_set = INITIALIZE_REG_SET (test_set_head);
2561 /* ??? bb->local_set is only valid during calculate_global_regs_live,
2562 so we must recompute usage for MERGE_BB. Not so bad, I suppose,
2563 since we've already asserted that MERGE_BB is small. */
2564 propagate_block (merge_bb, tmp, merge_set, merge_set, 0);
2566 /* For small register class machines, don't lengthen lifetimes of
2567 hard registers before reload. */
2568 if (SMALL_REGISTER_CLASSES && ! reload_completed)
2570 EXECUTE_IF_SET_IN_BITMAP
2573 if (i < FIRST_PSEUDO_REGISTER
2575 && ! global_regs[i])
2580 /* For TEST, we're interested in a range of insns, not a whole block.
2581 Moreover, we're interested in the insns live from OTHER_BB. */
2583 COPY_REG_SET (test_live, other_bb->global_live_at_start);
2584 pbi = init_propagate_block_info (test_bb, test_live, test_set, test_set,
2587 for (insn = jump; ; insn = prev)
2589 prev = propagate_one_insn (pbi, insn);
2590 if (insn == earliest)
2594 free_propagate_block_info (pbi);
2596 /* We can perform the transformation if
2597 MERGE_SET & (TEST_SET | TEST_LIVE)
2599 TEST_SET & merge_bb->global_live_at_start
2602 bitmap_operation (tmp, test_set, test_live, BITMAP_IOR);
2603 bitmap_operation (tmp, tmp, merge_set, BITMAP_AND);
2604 EXECUTE_IF_SET_IN_BITMAP(tmp, 0, i, fail = 1);
2606 bitmap_operation (tmp, test_set, merge_bb->global_live_at_start,
2608 EXECUTE_IF_SET_IN_BITMAP(tmp, 0, i, fail = 1);
2611 FREE_REG_SET (merge_set);
2612 FREE_REG_SET (test_live);
2613 FREE_REG_SET (test_set);
2620 /* We don't want to use normal invert_jump or redirect_jump because
2621 we don't want to delete_insn called. Also, we want to do our own
2622 change group management. */
2624 old_dest = JUMP_LABEL (jump);
2625 new_label = block_label (new_dest);
2627 ? ! invert_jump_1 (jump, new_label)
2628 : ! redirect_jump_1 (jump, new_label))
2631 if (! apply_change_group ())
2635 LABEL_NUSES (old_dest) -= 1;
2637 LABEL_NUSES (new_label) += 1;
2638 JUMP_LABEL (jump) = new_label;
2641 invert_br_probabilities (jump);
2643 redirect_edge_succ (BRANCH_EDGE (test_bb), new_dest);
2646 gcov_type count, probability;
2647 count = BRANCH_EDGE (test_bb)->count;
2648 BRANCH_EDGE (test_bb)->count = FALLTHRU_EDGE (test_bb)->count;
2649 FALLTHRU_EDGE (test_bb)->count = count;
2650 probability = BRANCH_EDGE (test_bb)->probability;
2651 BRANCH_EDGE (test_bb)->probability = FALLTHRU_EDGE (test_bb)->probability;
2652 FALLTHRU_EDGE (test_bb)->probability = probability;
2655 /* Move the insns out of MERGE_BB to before the branch. */
2658 if (end == merge_bb->end)
2659 merge_bb->end = PREV_INSN (head);
2661 squeeze_notes (&head, &end);
2663 reorder_insns (head, end, PREV_INSN (earliest));
2672 /* Main entry point for all if-conversion. */
2675 if_convert (x_life_data_ok)
2680 num_possible_if_blocks = 0;
2681 num_updated_if_blocks = 0;
2682 num_removed_blocks = 0;
2683 life_data_ok = (x_life_data_ok != 0);
2685 /* Free up basic_block_for_insn so that we don't have to keep it
2686 up to date, either here or in merge_blocks_nomove. */
2687 free_basic_block_vars (1);
2689 /* Compute postdominators if we think we'll use them. */
2690 post_dominators = NULL;
2691 if (HAVE_conditional_execution || life_data_ok)
2693 post_dominators = sbitmap_vector_alloc (n_basic_blocks, n_basic_blocks);
2694 calculate_dominance_info (NULL, post_dominators, CDI_POST_DOMINATORS);
2697 /* Record initial block numbers. */
2698 for (block_num = 0; block_num < n_basic_blocks; block_num++)
2699 SET_ORIG_INDEX (BASIC_BLOCK (block_num), block_num);
2701 /* Go through each of the basic blocks looking for things to convert. */
2702 for (block_num = 0; block_num < n_basic_blocks; )
2704 basic_block bb = BASIC_BLOCK (block_num);
2705 if (find_if_header (bb))
2706 block_num = bb->index;
2711 if (post_dominators)
2712 sbitmap_vector_free (post_dominators);
2715 fflush (rtl_dump_file);
2717 /* Rebuild life info for basic blocks that require it. */
2718 if (num_removed_blocks && life_data_ok)
2720 sbitmap update_life_blocks = sbitmap_alloc (n_basic_blocks);
2721 sbitmap_zero (update_life_blocks);
2723 /* If we allocated new pseudos, we must resize the array for sched1. */
2724 if (max_regno < max_reg_num ())
2726 max_regno = max_reg_num ();
2727 allocate_reg_info (max_regno, FALSE, FALSE);
2730 for (block_num = 0; block_num < n_basic_blocks; block_num++)
2731 if (UPDATE_LIFE (BASIC_BLOCK (block_num)))
2732 SET_BIT (update_life_blocks, block_num);
2734 count_or_remove_death_notes (update_life_blocks, 1);
2735 /* ??? See about adding a mode that verifies that the initial
2736 set of blocks don't let registers come live. */
2737 update_life_info (update_life_blocks, UPDATE_LIFE_GLOBAL,
2738 PROP_DEATH_NOTES | PROP_SCAN_DEAD_CODE
2739 | PROP_KILL_DEAD_CODE);
2741 sbitmap_free (update_life_blocks);
2744 /* Write the final stats. */
2745 if (rtl_dump_file && num_possible_if_blocks > 0)
2747 fprintf (rtl_dump_file,
2748 "\n%d possible IF blocks searched.\n",
2749 num_possible_if_blocks);
2750 fprintf (rtl_dump_file,
2751 "%d IF blocks converted.\n",
2752 num_updated_if_blocks);
2753 fprintf (rtl_dump_file,
2754 "%d basic blocks deleted.\n\n\n",
2755 num_removed_blocks);
2758 #ifdef ENABLE_CHECKING
2759 verify_flow_info ();