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 MIN (MEM_ALIGN (if_info->a), MEM_ALIGN (if_info->b)));
1115 noce_emit_move_insn (if_info->x, tmp);
1117 else if (target != x)
1118 noce_emit_move_insn (x, target);
1122 emit_insns_before (tmp, if_info->cond_earliest);
1130 /* For most cases, the simplified condition we found is the best
1131 choice, but this is not the case for the min/max/abs transforms.
1132 For these we wish to know that it is A or B in the condition. */
1135 noce_get_alt_condition (if_info, target, earliest)
1136 struct noce_if_info *if_info;
1140 rtx cond, set, insn;
1143 /* If target is already mentioned in the known condition, return it. */
1144 if (reg_mentioned_p (target, if_info->cond))
1146 *earliest = if_info->cond_earliest;
1147 return if_info->cond;
1150 set = pc_set (if_info->jump);
1151 cond = XEXP (SET_SRC (set), 0);
1153 = GET_CODE (XEXP (SET_SRC (set), 2)) == LABEL_REF
1154 && XEXP (XEXP (SET_SRC (set), 2), 0) == JUMP_LABEL (if_info->jump);
1156 /* If we're looking for a constant, try to make the conditional
1157 have that constant in it. There are two reasons why it may
1158 not have the constant we want:
1160 1. GCC may have needed to put the constant in a register, because
1161 the target can't compare directly against that constant. For
1162 this case, we look for a SET immediately before the comparison
1163 that puts a constant in that register.
1165 2. GCC may have canonicalized the conditional, for example
1166 replacing "if x < 4" with "if x <= 3". We can undo that (or
1167 make equivalent types of changes) to get the constants we need
1168 if they're off by one in the right direction. */
1170 if (GET_CODE (target) == CONST_INT)
1172 enum rtx_code code = GET_CODE (if_info->cond);
1173 rtx op_a = XEXP (if_info->cond, 0);
1174 rtx op_b = XEXP (if_info->cond, 1);
1177 /* First, look to see if we put a constant in a register. */
1178 prev_insn = PREV_INSN (if_info->cond_earliest);
1180 && INSN_P (prev_insn)
1181 && GET_CODE (PATTERN (prev_insn)) == SET)
1183 rtx src = find_reg_equal_equiv_note (prev_insn);
1185 src = SET_SRC (PATTERN (prev_insn));
1186 if (GET_CODE (src) == CONST_INT)
1188 if (rtx_equal_p (op_a, SET_DEST (PATTERN (prev_insn))))
1190 else if (rtx_equal_p (op_b, SET_DEST (PATTERN (prev_insn))))
1193 if (GET_CODE (op_a) == CONST_INT)
1198 code = swap_condition (code);
1203 /* Now, look to see if we can get the right constant by
1204 adjusting the conditional. */
1205 if (GET_CODE (op_b) == CONST_INT)
1207 HOST_WIDE_INT desired_val = INTVAL (target);
1208 HOST_WIDE_INT actual_val = INTVAL (op_b);
1213 if (actual_val == desired_val + 1)
1216 op_b = GEN_INT (desired_val);
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);
1245 /* If we made any changes, generate a new conditional that is
1246 equivalent to what we started with, but has the right
1248 if (code != GET_CODE (if_info->cond)
1249 || op_a != XEXP (if_info->cond, 0)
1250 || op_b != XEXP (if_info->cond, 1))
1252 cond = gen_rtx_fmt_ee (code, GET_MODE (cond), op_a, op_b);
1253 *earliest = if_info->cond_earliest;
1258 cond = canonicalize_condition (if_info->jump, cond, reverse,
1260 if (! cond || ! reg_mentioned_p (target, cond))
1263 /* We almost certainly searched back to a different place.
1264 Need to re-verify correct lifetimes. */
1266 /* X may not be mentioned in the range (cond_earliest, jump]. */
1267 for (insn = if_info->jump; insn != *earliest; insn = PREV_INSN (insn))
1268 if (INSN_P (insn) && reg_mentioned_p (if_info->x, insn))
1271 /* A and B may not be modified in the range [cond_earliest, jump). */
1272 for (insn = *earliest; insn != if_info->jump; insn = NEXT_INSN (insn))
1274 && (modified_in_p (if_info->a, insn)
1275 || modified_in_p (if_info->b, insn)))
1281 /* Convert "if (a < b) x = a; else x = b;" to "x = min(a, b);", etc. */
1284 noce_try_minmax (if_info)
1285 struct noce_if_info *if_info;
1287 rtx cond, earliest, target, seq;
1288 enum rtx_code code, op;
1291 /* ??? Can't guarantee that expand_binop won't create pseudos. */
1295 /* ??? Reject FP modes since we don't know how 0 vs -0 or NaNs
1296 will be resolved with an SMIN/SMAX. It wouldn't be too hard
1297 to get the target to tell us... */
1298 if (FLOAT_MODE_P (GET_MODE (if_info->x))
1299 && TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
1300 && ! flag_unsafe_math_optimizations)
1303 cond = noce_get_alt_condition (if_info, if_info->a, &earliest);
1307 /* Verify the condition is of the form we expect, and canonicalize
1308 the comparison code. */
1309 code = GET_CODE (cond);
1310 if (rtx_equal_p (XEXP (cond, 0), if_info->a))
1312 if (! rtx_equal_p (XEXP (cond, 1), if_info->b))
1315 else if (rtx_equal_p (XEXP (cond, 1), if_info->a))
1317 if (! rtx_equal_p (XEXP (cond, 0), if_info->b))
1319 code = swap_condition (code);
1324 /* Determine what sort of operation this is. Note that the code is for
1325 a taken branch, so the code->operation mapping appears backwards. */
1358 target = expand_simple_binop (GET_MODE (if_info->x), op,
1359 if_info->a, if_info->b,
1360 if_info->x, unsignedp, OPTAB_WIDEN);
1366 if (target != if_info->x)
1367 noce_emit_move_insn (if_info->x, target);
1372 if (seq_contains_jump (seq))
1375 emit_insns_before (seq, earliest);
1376 if_info->cond = cond;
1377 if_info->cond_earliest = earliest;
1382 /* Convert "if (a < 0) x = -a; else x = a;" to "x = abs(a);", etc. */
1385 noce_try_abs (if_info)
1386 struct noce_if_info *if_info;
1388 rtx cond, earliest, target, seq, a, b, c;
1391 /* ??? Can't guarantee that expand_binop won't create pseudos. */
1395 /* Recognize A and B as constituting an ABS or NABS. */
1398 if (GET_CODE (a) == NEG && rtx_equal_p (XEXP (a, 0), b))
1400 else if (GET_CODE (b) == NEG && rtx_equal_p (XEXP (b, 0), a))
1402 c = a; a = b; b = c;
1408 cond = noce_get_alt_condition (if_info, b, &earliest);
1412 /* Verify the condition is of the form we expect. */
1413 if (rtx_equal_p (XEXP (cond, 0), b))
1415 else if (rtx_equal_p (XEXP (cond, 1), b))
1420 /* Verify that C is zero. Search backward through the block for
1421 a REG_EQUAL note if necessary. */
1424 rtx insn, note = NULL;
1425 for (insn = earliest;
1426 insn != if_info->test_bb->head;
1427 insn = PREV_INSN (insn))
1429 && ((note = find_reg_note (insn, REG_EQUAL, c))
1430 || (note = find_reg_note (insn, REG_EQUIV, c))))
1436 if (GET_CODE (c) == MEM
1437 && GET_CODE (XEXP (c, 0)) == SYMBOL_REF
1438 && CONSTANT_POOL_ADDRESS_P (XEXP (c, 0)))
1439 c = get_pool_constant (XEXP (c, 0));
1441 /* Work around funny ideas get_condition has wrt canonicalization.
1442 Note that these rtx constants are known to be CONST_INT, and
1443 therefore imply integer comparisons. */
1444 if (c == constm1_rtx && GET_CODE (cond) == GT)
1446 else if (c == const1_rtx && GET_CODE (cond) == LT)
1448 else if (c != CONST0_RTX (GET_MODE (b)))
1451 /* Determine what sort of operation this is. */
1452 switch (GET_CODE (cond))
1471 target = expand_simple_unop (GET_MODE (if_info->x), ABS, b, if_info->x, 0);
1473 /* ??? It's a quandry whether cmove would be better here, especially
1474 for integers. Perhaps combine will clean things up. */
1475 if (target && negate)
1476 target = expand_simple_unop (GET_MODE (target), NEG, target, if_info->x, 0);
1484 if (target != if_info->x)
1485 noce_emit_move_insn (if_info->x, target);
1490 if (seq_contains_jump (seq))
1493 emit_insns_before (seq, earliest);
1494 if_info->cond = cond;
1495 if_info->cond_earliest = earliest;
1500 /* Look for the condition for the jump first. We'd prefer to avoid
1501 get_condition if we can -- it tries to look back for the contents
1502 of an original compare. On targets that use normal integers for
1503 comparisons, e.g. alpha, this is wasteful. */
1506 noce_get_condition (jump, earliest)
1513 /* If the condition variable is a register and is MODE_INT, accept it.
1514 Otherwise, fall back on get_condition. */
1516 if (! any_condjump_p (jump))
1519 set = pc_set (jump);
1521 cond = XEXP (SET_SRC (set), 0);
1522 if (GET_CODE (XEXP (cond, 0)) == REG
1523 && GET_MODE_CLASS (GET_MODE (XEXP (cond, 0))) == MODE_INT)
1527 /* If this branches to JUMP_LABEL when the condition is false,
1528 reverse the condition. */
1529 if (GET_CODE (XEXP (SET_SRC (set), 2)) == LABEL_REF
1530 && XEXP (XEXP (SET_SRC (set), 2), 0) == JUMP_LABEL (jump))
1531 cond = gen_rtx_fmt_ee (reverse_condition (GET_CODE (cond)),
1532 GET_MODE (cond), XEXP (cond, 0),
1536 cond = get_condition (jump, earliest);
1541 /* Return true if OP is ok for if-then-else processing. */
1544 noce_operand_ok (op)
1547 /* We special-case memories, so handle any of them with
1548 no address side effects. */
1549 if (GET_CODE (op) == MEM)
1550 return ! side_effects_p (XEXP (op, 0));
1552 if (side_effects_p (op))
1555 /* ??? Unfortuantely may_trap_p can't look at flag_trapping_math, due to
1556 being linked into the genfoo programs. This is probably a mistake.
1557 With finite operands, most fp operations don't trap. */
1558 if (!flag_trapping_math && FLOAT_MODE_P (GET_MODE (op)))
1559 switch (GET_CODE (op))
1565 /* ??? This is kinda lame -- almost every target will have forced
1566 the constant into a register first. But given the expense of
1567 division, this is probably for the best. */
1568 return (CONSTANT_P (XEXP (op, 1))
1569 && XEXP (op, 1) != CONST0_RTX (GET_MODE (op))
1570 && ! may_trap_p (XEXP (op, 0)));
1573 switch (GET_RTX_CLASS (GET_CODE (op)))
1576 return ! may_trap_p (XEXP (op, 0));
1579 return ! may_trap_p (XEXP (op, 0)) && ! may_trap_p (XEXP (op, 1));
1584 return ! may_trap_p (op);
1587 /* Given a simple IF-THEN or IF-THEN-ELSE block, attempt to convert it
1588 without using conditional execution. Return TRUE if we were
1589 successful at converting the the block. */
1592 noce_process_if_block (test_bb, then_bb, else_bb, join_bb)
1593 basic_block test_bb; /* Basic block test is in */
1594 basic_block then_bb; /* Basic block for THEN block */
1595 basic_block else_bb; /* Basic block for ELSE block */
1596 basic_block join_bb; /* Basic block the join label is in */
1598 /* We're looking for patterns of the form
1600 (1) if (...) x = a; else x = b;
1601 (2) x = b; if (...) x = a;
1602 (3) if (...) x = a; // as if with an initial x = x.
1604 The later patterns require jumps to be more expensive.
1606 ??? For future expansion, look for multiple X in such patterns. */
1608 struct noce_if_info if_info;
1611 rtx orig_x, x, a, b;
1612 rtx jump, cond, insn;
1614 /* If this is not a standard conditional jump, we can't parse it. */
1615 jump = test_bb->end;
1616 cond = noce_get_condition (jump, &if_info.cond_earliest);
1620 /* If the conditional jump is more than just a conditional jump,
1621 then we can not do if-conversion on this block. */
1622 if (! onlyjump_p (jump))
1625 /* We must be comparing objects whose modes imply the size. */
1626 if (GET_MODE (XEXP (cond, 0)) == BLKmode)
1629 /* Look for one of the potential sets. */
1630 insn_a = first_active_insn (then_bb);
1632 || ! last_active_insn_p (then_bb, insn_a)
1633 || (set_a = single_set (insn_a)) == NULL_RTX)
1636 x = SET_DEST (set_a);
1637 a = SET_SRC (set_a);
1639 /* Look for the other potential set. Make sure we've got equivalent
1641 /* ??? This is overconservative. Storing to two different mems is
1642 as easy as conditionally computing the address. Storing to a
1643 single mem merely requires a scratch memory to use as one of the
1644 destination addresses; often the memory immediately below the
1645 stack pointer is available for this. */
1649 insn_b = first_active_insn (else_bb);
1651 || ! last_active_insn_p (else_bb, insn_b)
1652 || (set_b = single_set (insn_b)) == NULL_RTX
1653 || ! rtx_equal_p (x, SET_DEST (set_b)))
1658 insn_b = prev_nonnote_insn (if_info.cond_earliest);
1660 || GET_CODE (insn_b) != INSN
1661 || (set_b = single_set (insn_b)) == NULL_RTX
1662 || ! rtx_equal_p (x, SET_DEST (set_b))
1663 || reg_mentioned_p (x, cond)
1664 || reg_mentioned_p (x, a)
1665 || reg_mentioned_p (x, SET_SRC (set_b)))
1666 insn_b = set_b = NULL_RTX;
1668 b = (set_b ? SET_SRC (set_b) : x);
1670 /* X may not be mentioned in the range (cond_earliest, jump]. */
1671 for (insn = jump; insn != if_info.cond_earliest; insn = PREV_INSN (insn))
1672 if (INSN_P (insn) && reg_mentioned_p (x, insn))
1675 /* A and B may not be modified in the range [cond_earliest, jump). */
1676 for (insn = if_info.cond_earliest; insn != jump; insn = NEXT_INSN (insn))
1678 && (modified_in_p (a, insn) || modified_in_p (b, insn)))
1681 /* Only operate on register destinations, and even then avoid extending
1682 the lifetime of hard registers on small register class machines. */
1684 if (GET_CODE (x) != REG
1685 || (SMALL_REGISTER_CLASSES
1686 && REGNO (x) < FIRST_PSEUDO_REGISTER))
1690 x = gen_reg_rtx (GET_MODE (GET_CODE (x) == STRICT_LOW_PART
1691 ? XEXP (x, 0) : x));
1694 /* Don't operate on sources that may trap or are volatile. */
1695 if (! noce_operand_ok (a) || ! noce_operand_ok (b))
1698 /* Set up the info block for our subroutines. */
1699 if_info.test_bb = test_bb;
1700 if_info.cond = cond;
1701 if_info.jump = jump;
1702 if_info.insn_a = insn_a;
1703 if_info.insn_b = insn_b;
1708 /* Try optimizations in some approximation of a useful order. */
1709 /* ??? Should first look to see if X is live incoming at all. If it
1710 isn't, we don't need anything but an unconditional set. */
1712 /* Look and see if A and B are really the same. Avoid creating silly
1713 cmove constructs that no one will fix up later. */
1714 if (rtx_equal_p (a, b))
1716 /* If we have an INSN_B, we don't have to create any new rtl. Just
1717 move the instruction that we already have. If we don't have an
1718 INSN_B, that means that A == X, and we've got a noop move. In
1719 that case don't do anything and let the code below delete INSN_A. */
1720 if (insn_b && else_bb)
1724 if (else_bb && insn_b == else_bb->end)
1725 else_bb->end = PREV_INSN (insn_b);
1726 reorder_insns (insn_b, insn_b, PREV_INSN (if_info.cond_earliest));
1728 /* If there was a REG_EQUAL note, delete it since it may have been
1729 true due to this insn being after a jump. */
1730 if ((note = find_reg_note (insn_b, REG_EQUAL, NULL_RTX)) != 0)
1731 remove_note (insn_b, note);
1735 /* If we have "x = b; if (...) x = a;", and x has side-effects, then
1736 x must be executed twice. */
1737 else if (insn_b && side_effects_p (orig_x))
1744 if (noce_try_store_flag (&if_info))
1746 if (noce_try_minmax (&if_info))
1748 if (noce_try_abs (&if_info))
1750 if (HAVE_conditional_move
1751 && noce_try_cmove (&if_info))
1753 if (! HAVE_conditional_execution)
1755 if (noce_try_store_flag_constants (&if_info))
1757 if (noce_try_store_flag_inc (&if_info))
1759 if (noce_try_store_flag_mask (&if_info))
1761 if (HAVE_conditional_move
1762 && noce_try_cmove_arith (&if_info))
1769 /* The original sets may now be killed. */
1770 delete_insn (insn_a);
1772 /* Several special cases here: First, we may have reused insn_b above,
1773 in which case insn_b is now NULL. Second, we want to delete insn_b
1774 if it came from the ELSE block, because follows the now correct
1775 write that appears in the TEST block. However, if we got insn_b from
1776 the TEST block, it may in fact be loading data needed for the comparison.
1777 We'll let life_analysis remove the insn if it's really dead. */
1778 if (insn_b && else_bb)
1779 delete_insn (insn_b);
1781 /* The new insns will have been inserted before cond_earliest. We should
1782 be able to remove the jump with impunity, but the condition itself may
1783 have been modified by gcse to be shared across basic blocks. */
1786 /* If we used a temporary, fix it up now. */
1790 noce_emit_move_insn (orig_x, x);
1791 insn_b = gen_sequence ();
1794 emit_insn_after (insn_b, test_bb->end);
1797 /* Merge the blocks! */
1798 merge_if_block (test_bb, then_bb, else_bb, join_bb);
1803 /* Attempt to convert an IF-THEN or IF-THEN-ELSE block into
1804 straight line code. Return true if successful. */
1807 process_if_block (test_bb, then_bb, else_bb, join_bb)
1808 basic_block test_bb; /* Basic block test is in */
1809 basic_block then_bb; /* Basic block for THEN block */
1810 basic_block else_bb; /* Basic block for ELSE block */
1811 basic_block join_bb; /* Basic block the join label is in */
1813 if (! reload_completed
1814 && noce_process_if_block (test_bb, then_bb, else_bb, join_bb))
1817 if (HAVE_conditional_execution
1819 && cond_exec_process_if_block (test_bb, then_bb, else_bb, join_bb))
1825 /* Merge the blocks and mark for local life update. */
1828 merge_if_block (test_bb, then_bb, else_bb, join_bb)
1829 basic_block test_bb; /* Basic block test is in */
1830 basic_block then_bb; /* Basic block for THEN block */
1831 basic_block else_bb; /* Basic block for ELSE block */
1832 basic_block join_bb; /* Basic block the join label is in */
1834 basic_block combo_bb;
1836 /* All block merging is done into the lower block numbers. */
1840 /* First merge TEST block into THEN block. This is a no-brainer since
1841 the THEN block did not have a code label to begin with. */
1844 COPY_REG_SET (combo_bb->global_live_at_end, then_bb->global_live_at_end);
1845 merge_blocks_nomove (combo_bb, then_bb);
1846 num_removed_blocks++;
1848 /* The ELSE block, if it existed, had a label. That label count
1849 will almost always be zero, but odd things can happen when labels
1850 get their addresses taken. */
1853 merge_blocks_nomove (combo_bb, else_bb);
1854 num_removed_blocks++;
1857 /* If there was no join block reported, that means it was not adjacent
1858 to the others, and so we cannot merge them. */
1862 /* The outgoing edge for the current COMBO block should already
1863 be correct. Verify this. */
1864 if (combo_bb->succ == NULL_EDGE)
1867 /* There should still be a branch at the end of the THEN or ELSE
1868 blocks taking us to our final destination. */
1869 if (GET_CODE (combo_bb->end) != JUMP_INSN)
1873 /* The JOIN block may have had quite a number of other predecessors too.
1874 Since we've already merged the TEST, THEN and ELSE blocks, we should
1875 have only one remaining edge from our if-then-else diamond. If there
1876 is more than one remaining edge, it must come from elsewhere. There
1877 may be zero incoming edges if the THEN block didn't actually join
1878 back up (as with a call to abort). */
1879 else if ((join_bb->pred == NULL
1880 || join_bb->pred->pred_next == NULL)
1881 && join_bb != EXIT_BLOCK_PTR)
1883 /* We can merge the JOIN. */
1885 COPY_REG_SET (combo_bb->global_live_at_end,
1886 join_bb->global_live_at_end);
1887 merge_blocks_nomove (combo_bb, join_bb);
1888 num_removed_blocks++;
1892 /* We cannot merge the JOIN. */
1894 /* The outgoing edge for the current COMBO block should already
1895 be correct. Verify this. */
1896 if (combo_bb->succ->succ_next != NULL_EDGE
1897 || combo_bb->succ->dest != join_bb)
1900 /* Remove the jump and cruft from the end of the COMBO block. */
1901 if (join_bb != EXIT_BLOCK_PTR)
1902 tidy_fallthru_edge (combo_bb->succ, combo_bb, join_bb);
1905 /* Make sure we update life info properly. */
1906 SET_UPDATE_LIFE (combo_bb);
1908 num_updated_if_blocks++;
1911 /* Find a block ending in a simple IF condition. Return TRUE if
1912 we were able to transform it in some way. */
1915 find_if_header (test_bb)
1916 basic_block test_bb;
1921 /* The kind of block we're looking for has exactly two successors. */
1922 if ((then_edge = test_bb->succ) == NULL_EDGE
1923 || (else_edge = then_edge->succ_next) == NULL_EDGE
1924 || else_edge->succ_next != NULL_EDGE)
1927 /* Neither edge should be abnormal. */
1928 if ((then_edge->flags & EDGE_COMPLEX)
1929 || (else_edge->flags & EDGE_COMPLEX))
1932 /* The THEN edge is canonically the one that falls through. */
1933 if (then_edge->flags & EDGE_FALLTHRU)
1935 else if (else_edge->flags & EDGE_FALLTHRU)
1938 else_edge = then_edge;
1942 /* Otherwise this must be a multiway branch of some sort. */
1945 if (find_if_block (test_bb, then_edge, else_edge))
1947 if (HAVE_trap && HAVE_conditional_trap
1948 && find_cond_trap (test_bb, then_edge, else_edge))
1951 && (! HAVE_conditional_execution || reload_completed))
1953 if (find_if_case_1 (test_bb, then_edge, else_edge))
1955 if (find_if_case_2 (test_bb, then_edge, else_edge))
1963 fprintf (rtl_dump_file, "Conversion succeeded.\n");
1967 /* Determine if a given basic block heads a simple IF-THEN or IF-THEN-ELSE
1968 block. If so, we'll try to convert the insns to not require the branch.
1969 Return TRUE if we were successful at converting the the block. */
1972 find_if_block (test_bb, then_edge, else_edge)
1973 basic_block test_bb;
1974 edge then_edge, else_edge;
1976 basic_block then_bb = then_edge->dest;
1977 basic_block else_bb = else_edge->dest;
1978 basic_block join_bb = NULL_BLOCK;
1979 edge then_succ = then_bb->succ;
1980 edge else_succ = else_bb->succ;
1983 /* The THEN block of an IF-THEN combo must have exactly one predecessor. */
1984 if (then_bb->pred->pred_next != NULL_EDGE)
1987 /* The THEN block of an IF-THEN combo must have zero or one successors. */
1988 if (then_succ != NULL_EDGE
1989 && (then_succ->succ_next != NULL_EDGE
1990 || (then_succ->flags & EDGE_COMPLEX)))
1993 /* If the THEN block has no successors, conditional execution can still
1994 make a conditional call. Don't do this unless the ELSE block has
1995 only one incoming edge -- the CFG manipulation is too ugly otherwise.
1996 Check for the last insn of the THEN block being an indirect jump, which
1997 is listed as not having any successors, but confuses the rest of the CE
1998 code processing. XXX we should fix this in the future. */
1999 if (then_succ == NULL)
2001 if (else_bb->pred->pred_next == NULL_EDGE)
2003 rtx last_insn = then_bb->end;
2006 && GET_CODE (last_insn) == NOTE
2007 && last_insn != then_bb->head)
2008 last_insn = PREV_INSN (last_insn);
2011 && GET_CODE (last_insn) == JUMP_INSN
2012 && ! simplejump_p (last_insn))
2016 else_bb = NULL_BLOCK;
2022 /* If the THEN block's successor is the other edge out of the TEST block,
2023 then we have an IF-THEN combo without an ELSE. */
2024 else if (then_succ->dest == else_bb)
2027 else_bb = NULL_BLOCK;
2030 /* If the THEN and ELSE block meet in a subsequent block, and the ELSE
2031 has exactly one predecessor and one successor, and the outgoing edge
2032 is not complex, then we have an IF-THEN-ELSE combo. */
2033 else if (else_succ != NULL_EDGE
2034 && then_succ->dest == else_succ->dest
2035 && else_bb->pred->pred_next == NULL_EDGE
2036 && else_succ->succ_next == NULL_EDGE
2037 && ! (else_succ->flags & EDGE_COMPLEX))
2038 join_bb = else_succ->dest;
2040 /* Otherwise it is not an IF-THEN or IF-THEN-ELSE combination. */
2044 num_possible_if_blocks++;
2049 fprintf (rtl_dump_file,
2050 "\nIF-THEN-ELSE block found, start %d, then %d, else %d, join %d\n",
2051 test_bb->index, then_bb->index, else_bb->index,
2054 fprintf (rtl_dump_file,
2055 "\nIF-THEN block found, start %d, then %d, join %d\n",
2056 test_bb->index, then_bb->index, join_bb->index);
2059 /* Make sure IF, THEN, and ELSE, blocks are adjacent. Actually, we
2060 get the first condition for free, since we've already asserted that
2061 there's a fallthru edge from IF to THEN. */
2062 /* ??? As an enhancement, move the ELSE block. Have to deal with
2063 BLOCK notes, if by no other means than aborting the merge if they
2064 exist. Sticky enough I don't want to think about it now. */
2065 next_index = then_bb->index;
2066 if (else_bb && ++next_index != else_bb->index)
2068 if (++next_index != join_bb->index && join_bb->index != EXIT_BLOCK)
2076 /* Do the real work. */
2077 return process_if_block (test_bb, then_bb, else_bb, join_bb);
2080 /* Convert a branch over a trap, or a branch to a trap,
2081 into a conditional trap. */
2084 find_cond_trap (test_bb, then_edge, else_edge)
2085 basic_block test_bb;
2086 edge then_edge, else_edge;
2088 basic_block then_bb, else_bb, join_bb, trap_bb;
2089 rtx trap, jump, cond, cond_earliest, seq;
2092 then_bb = then_edge->dest;
2093 else_bb = else_edge->dest;
2096 /* Locate the block with the trap instruction. */
2097 /* ??? While we look for no successors, we really ought to allow
2098 EH successors. Need to fix merge_if_block for that to work. */
2099 /* ??? We can't currently handle merging the blocks if they are not
2100 already adjacent. Prevent losage in merge_if_block by detecting
2102 if (then_bb->succ == NULL)
2105 if (else_bb->index != then_bb->index + 1)
2110 else if (else_bb->succ == NULL)
2113 if (else_bb->index != then_bb->index + 1)
2115 else if (then_bb->succ
2116 && ! then_bb->succ->succ_next
2117 && ! (then_bb->succ->flags & EDGE_COMPLEX)
2118 && then_bb->succ->dest->index == else_bb->index + 1)
2119 join_bb = then_bb->succ->dest;
2124 /* Don't confuse a conditional return with something we want to
2126 if (trap_bb == EXIT_BLOCK_PTR)
2129 /* The only instruction in the THEN block must be the trap. */
2130 trap = first_active_insn (trap_bb);
2131 if (! (trap == trap_bb->end
2132 && GET_CODE (PATTERN (trap)) == TRAP_IF
2133 && TRAP_CONDITION (PATTERN (trap)) == const_true_rtx))
2138 if (trap_bb == then_bb)
2139 fprintf (rtl_dump_file,
2140 "\nTRAP-IF block found, start %d, trap %d",
2141 test_bb->index, then_bb->index);
2143 fprintf (rtl_dump_file,
2144 "\nTRAP-IF block found, start %d, then %d, trap %d",
2145 test_bb->index, then_bb->index, trap_bb->index);
2147 fprintf (rtl_dump_file, ", join %d\n", join_bb->index);
2149 fputc ('\n', rtl_dump_file);
2152 /* If this is not a standard conditional jump, we can't parse it. */
2153 jump = test_bb->end;
2154 cond = noce_get_condition (jump, &cond_earliest);
2158 /* If the conditional jump is more than just a conditional jump,
2159 then we can not do if-conversion on this block. */
2160 if (! onlyjump_p (jump))
2163 /* We must be comparing objects whose modes imply the size. */
2164 if (GET_MODE (XEXP (cond, 0)) == BLKmode)
2167 /* Reverse the comparison code, if necessary. */
2168 code = GET_CODE (cond);
2169 if (then_bb == trap_bb)
2171 code = reversed_comparison_code (cond, jump);
2172 if (code == UNKNOWN)
2176 /* Attempt to generate the conditional trap. */
2177 seq = gen_cond_trap (code, XEXP (cond, 0), XEXP (cond, 1),
2178 TRAP_CODE (PATTERN (trap)));
2182 /* Emit the new insns before cond_earliest; delete the old jump
2185 emit_insn_before (seq, cond_earliest);
2191 /* Merge the blocks! */
2192 if (trap_bb != then_bb && ! else_bb)
2194 flow_delete_block (trap_bb);
2195 num_removed_blocks++;
2197 merge_if_block (test_bb, then_bb, else_bb, join_bb);
2202 /* Look for IF-THEN-ELSE cases in which one of THEN or ELSE is
2203 transformable, but not necessarily the other. There need be no
2206 Return TRUE if we were successful at converting the the block.
2208 Cases we'd like to look at:
2211 if (test) goto over; // x not live
2219 if (! test) goto label;
2222 if (test) goto E; // x not live
2236 (3) // This one's really only interesting for targets that can do
2237 // multiway branching, e.g. IA-64 BBB bundles. For other targets
2238 // it results in multiple branches on a cache line, which often
2239 // does not sit well with predictors.
2241 if (test1) goto E; // predicted not taken
2257 (A) Don't do (2) if the branch is predicted against the block we're
2258 eliminating. Do it anyway if we can eliminate a branch; this requires
2259 that the sole successor of the eliminated block postdominate the other
2262 (B) With CE, on (3) we can steal from both sides of the if, creating
2271 Again, this is most useful if J postdominates.
2273 (C) CE substitutes for helpful life information.
2275 (D) These heuristics need a lot of work. */
2277 /* Tests for case 1 above. */
2280 find_if_case_1 (test_bb, then_edge, else_edge)
2281 basic_block test_bb;
2282 edge then_edge, else_edge;
2284 basic_block then_bb = then_edge->dest;
2285 basic_block else_bb = else_edge->dest, new_bb;
2286 edge then_succ = then_bb->succ;
2288 /* THEN has one successor. */
2289 if (!then_succ || then_succ->succ_next != NULL)
2292 /* THEN does not fall through, but is not strange either. */
2293 if (then_succ->flags & (EDGE_COMPLEX | EDGE_FALLTHRU))
2296 /* THEN has one predecessor. */
2297 if (then_bb->pred->pred_next != NULL)
2300 /* THEN must do something. */
2301 if (forwarder_block_p (then_bb))
2304 num_possible_if_blocks++;
2306 fprintf (rtl_dump_file,
2307 "\nIF-CASE-1 found, start %d, then %d\n",
2308 test_bb->index, then_bb->index);
2310 /* THEN is small. */
2311 if (count_bb_insns (then_bb) > BRANCH_COST)
2314 /* Registers set are dead, or are predicable. */
2315 if (! dead_or_predicable (test_bb, then_bb, else_bb,
2316 then_bb->succ->dest, 1))
2319 /* Conversion went ok, including moving the insns and fixing up the
2320 jump. Adjust the CFG to match. */
2322 SET_UPDATE_LIFE (test_bb);
2323 bitmap_operation (test_bb->global_live_at_end,
2324 else_bb->global_live_at_start,
2325 then_bb->global_live_at_end, BITMAP_IOR);
2327 new_bb = redirect_edge_and_branch_force (FALLTHRU_EDGE (test_bb), else_bb);
2328 /* Make rest of code believe that the newly created block is the THEN_BB
2329 block we are going to remove. */
2332 new_bb->aux = then_bb->aux;
2333 SET_UPDATE_LIFE (then_bb);
2335 flow_delete_block (then_bb);
2336 /* We've possibly created jump to next insn, cleanup_cfg will solve that
2339 num_removed_blocks++;
2340 num_updated_if_blocks++;
2345 /* Test for case 2 above. */
2348 find_if_case_2 (test_bb, then_edge, else_edge)
2349 basic_block test_bb;
2350 edge then_edge, else_edge;
2352 basic_block then_bb = then_edge->dest;
2353 basic_block else_bb = else_edge->dest;
2354 edge else_succ = else_bb->succ;
2357 /* ELSE has one successor. */
2358 if (!else_succ || else_succ->succ_next != NULL)
2361 /* ELSE outgoing edge is not complex. */
2362 if (else_succ->flags & EDGE_COMPLEX)
2365 /* ELSE has one predecessor. */
2366 if (else_bb->pred->pred_next != NULL)
2369 /* THEN is not EXIT. */
2370 if (then_bb->index < 0)
2373 /* ELSE is predicted or SUCC(ELSE) postdominates THEN. */
2374 note = find_reg_note (test_bb->end, REG_BR_PROB, NULL_RTX);
2375 if (note && INTVAL (XEXP (note, 0)) >= REG_BR_PROB_BASE / 2)
2377 else if (else_succ->dest->index < 0
2378 || TEST_BIT (post_dominators[ORIG_INDEX (then_bb)],
2379 ORIG_INDEX (else_succ->dest)))
2384 num_possible_if_blocks++;
2386 fprintf (rtl_dump_file,
2387 "\nIF-CASE-2 found, start %d, else %d\n",
2388 test_bb->index, else_bb->index);
2390 /* ELSE is small. */
2391 if (count_bb_insns (then_bb) > BRANCH_COST)
2394 /* Registers set are dead, or are predicable. */
2395 if (! dead_or_predicable (test_bb, else_bb, then_bb, else_succ->dest, 0))
2398 /* Conversion went ok, including moving the insns and fixing up the
2399 jump. Adjust the CFG to match. */
2401 SET_UPDATE_LIFE (test_bb);
2402 bitmap_operation (test_bb->global_live_at_end,
2403 then_bb->global_live_at_start,
2404 else_bb->global_live_at_end, BITMAP_IOR);
2406 flow_delete_block (else_bb);
2408 num_removed_blocks++;
2409 num_updated_if_blocks++;
2411 /* ??? We may now fallthru from one of THEN's successors into a join
2412 block. Rerun cleanup_cfg? Examine things manually? Wait? */
2417 /* A subroutine of dead_or_predicable called through for_each_rtx.
2418 Return 1 if a memory is found. */
2421 find_memory (px, data)
2423 void *data ATTRIBUTE_UNUSED;
2425 return GET_CODE (*px) == MEM;
2428 /* Used by the code above to perform the actual rtl transformations.
2429 Return TRUE if successful.
2431 TEST_BB is the block containing the conditional branch. MERGE_BB
2432 is the block containing the code to manipulate. NEW_DEST is the
2433 label TEST_BB should be branching to after the conversion.
2434 REVERSEP is true if the sense of the branch should be reversed. */
2437 dead_or_predicable (test_bb, merge_bb, other_bb, new_dest, reversep)
2438 basic_block test_bb, merge_bb, other_bb;
2439 basic_block new_dest;
2442 rtx head, end, jump, earliest, old_dest, new_label;
2444 jump = test_bb->end;
2446 /* Find the extent of the real code in the merge block. */
2447 head = merge_bb->head;
2448 end = merge_bb->end;
2450 if (GET_CODE (head) == CODE_LABEL)
2451 head = NEXT_INSN (head);
2452 if (GET_CODE (head) == NOTE)
2456 head = end = NULL_RTX;
2459 head = NEXT_INSN (head);
2462 if (GET_CODE (end) == JUMP_INSN)
2466 head = end = NULL_RTX;
2469 end = PREV_INSN (end);
2472 /* Disable handling dead code by conditional execution if the machine needs
2473 to do anything funny with the tests, etc. */
2474 #ifndef IFCVT_MODIFY_TESTS
2475 if (HAVE_conditional_execution)
2477 /* In the conditional execution case, we have things easy. We know
2478 the condition is reversable. We don't have to check life info,
2479 becase we're going to conditionally execute the code anyway.
2480 All that's left is making sure the insns involved can actually
2485 cond = cond_exec_get_condition (jump);
2489 prob_val = find_reg_note (jump, REG_BR_PROB, NULL_RTX);
2491 prob_val = XEXP (prob_val, 0);
2495 enum rtx_code rev = reversed_comparison_code (cond, jump);
2498 cond = gen_rtx_fmt_ee (rev, GET_MODE (cond), XEXP (cond, 0),
2501 prob_val = GEN_INT (REG_BR_PROB_BASE - INTVAL (prob_val));
2504 if (! cond_exec_process_insns (head, end, cond, prob_val, 0))
2512 /* In the non-conditional execution case, we have to verify that there
2513 are no trapping operations, no calls, no references to memory, and
2514 that any registers modified are dead at the branch site. */
2516 rtx insn, cond, prev;
2517 regset_head merge_set_head, tmp_head, test_live_head, test_set_head;
2518 regset merge_set, tmp, test_live, test_set;
2519 struct propagate_block_info *pbi;
2522 /* Check for no calls or trapping operations. */
2523 for (insn = head; ; insn = NEXT_INSN (insn))
2525 if (GET_CODE (insn) == CALL_INSN)
2529 if (may_trap_p (PATTERN (insn)))
2532 /* ??? Even non-trapping memories such as stack frame
2533 references must be avoided. For stores, we collect
2534 no lifetime info; for reads, we'd have to assert
2535 true_dependance false against every store in the
2537 if (for_each_rtx (&PATTERN (insn), find_memory, NULL))
2544 if (! any_condjump_p (jump))
2547 /* Find the extent of the conditional. */
2548 cond = noce_get_condition (jump, &earliest);
2553 MERGE_SET = set of registers set in MERGE_BB
2554 TEST_LIVE = set of registers live at EARLIEST
2555 TEST_SET = set of registers set between EARLIEST and the
2556 end of the block. */
2558 tmp = INITIALIZE_REG_SET (tmp_head);
2559 merge_set = INITIALIZE_REG_SET (merge_set_head);
2560 test_live = INITIALIZE_REG_SET (test_live_head);
2561 test_set = INITIALIZE_REG_SET (test_set_head);
2563 /* ??? bb->local_set is only valid during calculate_global_regs_live,
2564 so we must recompute usage for MERGE_BB. Not so bad, I suppose,
2565 since we've already asserted that MERGE_BB is small. */
2566 propagate_block (merge_bb, tmp, merge_set, merge_set, 0);
2568 /* For small register class machines, don't lengthen lifetimes of
2569 hard registers before reload. */
2570 if (SMALL_REGISTER_CLASSES && ! reload_completed)
2572 EXECUTE_IF_SET_IN_BITMAP
2575 if (i < FIRST_PSEUDO_REGISTER
2577 && ! global_regs[i])
2582 /* For TEST, we're interested in a range of insns, not a whole block.
2583 Moreover, we're interested in the insns live from OTHER_BB. */
2585 COPY_REG_SET (test_live, other_bb->global_live_at_start);
2586 pbi = init_propagate_block_info (test_bb, test_live, test_set, test_set,
2589 for (insn = jump; ; insn = prev)
2591 prev = propagate_one_insn (pbi, insn);
2592 if (insn == earliest)
2596 free_propagate_block_info (pbi);
2598 /* We can perform the transformation if
2599 MERGE_SET & (TEST_SET | TEST_LIVE)
2601 TEST_SET & merge_bb->global_live_at_start
2604 bitmap_operation (tmp, test_set, test_live, BITMAP_IOR);
2605 bitmap_operation (tmp, tmp, merge_set, BITMAP_AND);
2606 EXECUTE_IF_SET_IN_BITMAP(tmp, 0, i, fail = 1);
2608 bitmap_operation (tmp, test_set, merge_bb->global_live_at_start,
2610 EXECUTE_IF_SET_IN_BITMAP(tmp, 0, i, fail = 1);
2613 FREE_REG_SET (merge_set);
2614 FREE_REG_SET (test_live);
2615 FREE_REG_SET (test_set);
2622 /* We don't want to use normal invert_jump or redirect_jump because
2623 we don't want to delete_insn called. Also, we want to do our own
2624 change group management. */
2626 old_dest = JUMP_LABEL (jump);
2627 new_label = block_label (new_dest);
2629 ? ! invert_jump_1 (jump, new_label)
2630 : ! redirect_jump_1 (jump, new_label))
2633 if (! apply_change_group ())
2637 LABEL_NUSES (old_dest) -= 1;
2639 LABEL_NUSES (new_label) += 1;
2640 JUMP_LABEL (jump) = new_label;
2643 invert_br_probabilities (jump);
2645 redirect_edge_succ (BRANCH_EDGE (test_bb), new_dest);
2648 gcov_type count, probability;
2649 count = BRANCH_EDGE (test_bb)->count;
2650 BRANCH_EDGE (test_bb)->count = FALLTHRU_EDGE (test_bb)->count;
2651 FALLTHRU_EDGE (test_bb)->count = count;
2652 probability = BRANCH_EDGE (test_bb)->probability;
2653 BRANCH_EDGE (test_bb)->probability = FALLTHRU_EDGE (test_bb)->probability;
2654 FALLTHRU_EDGE (test_bb)->probability = probability;
2657 /* Move the insns out of MERGE_BB to before the branch. */
2660 if (end == merge_bb->end)
2661 merge_bb->end = PREV_INSN (head);
2663 squeeze_notes (&head, &end);
2665 reorder_insns (head, end, PREV_INSN (earliest));
2674 /* Main entry point for all if-conversion. */
2677 if_convert (x_life_data_ok)
2682 num_possible_if_blocks = 0;
2683 num_updated_if_blocks = 0;
2684 num_removed_blocks = 0;
2685 life_data_ok = (x_life_data_ok != 0);
2687 /* Free up basic_block_for_insn so that we don't have to keep it
2688 up to date, either here or in merge_blocks_nomove. */
2689 free_basic_block_vars (1);
2691 /* Compute postdominators if we think we'll use them. */
2692 post_dominators = NULL;
2693 if (HAVE_conditional_execution || life_data_ok)
2695 post_dominators = sbitmap_vector_alloc (n_basic_blocks, n_basic_blocks);
2696 calculate_dominance_info (NULL, post_dominators, CDI_POST_DOMINATORS);
2699 /* Record initial block numbers. */
2700 for (block_num = 0; block_num < n_basic_blocks; block_num++)
2701 SET_ORIG_INDEX (BASIC_BLOCK (block_num), block_num);
2703 /* Go through each of the basic blocks looking for things to convert. */
2704 for (block_num = 0; block_num < n_basic_blocks; )
2706 basic_block bb = BASIC_BLOCK (block_num);
2707 if (find_if_header (bb))
2708 block_num = bb->index;
2713 if (post_dominators)
2714 sbitmap_vector_free (post_dominators);
2717 fflush (rtl_dump_file);
2719 /* Rebuild life info for basic blocks that require it. */
2720 if (num_removed_blocks && life_data_ok)
2722 sbitmap update_life_blocks = sbitmap_alloc (n_basic_blocks);
2723 sbitmap_zero (update_life_blocks);
2725 /* If we allocated new pseudos, we must resize the array for sched1. */
2726 if (max_regno < max_reg_num ())
2728 max_regno = max_reg_num ();
2729 allocate_reg_info (max_regno, FALSE, FALSE);
2732 for (block_num = 0; block_num < n_basic_blocks; block_num++)
2733 if (UPDATE_LIFE (BASIC_BLOCK (block_num)))
2734 SET_BIT (update_life_blocks, block_num);
2736 count_or_remove_death_notes (update_life_blocks, 1);
2737 /* ??? See about adding a mode that verifies that the initial
2738 set of blocks don't let registers come live. */
2739 update_life_info (update_life_blocks, UPDATE_LIFE_GLOBAL,
2740 PROP_DEATH_NOTES | PROP_SCAN_DEAD_CODE
2741 | PROP_KILL_DEAD_CODE);
2743 sbitmap_free (update_life_blocks);
2745 clear_aux_for_blocks ();
2747 /* Write the final stats. */
2748 if (rtl_dump_file && num_possible_if_blocks > 0)
2750 fprintf (rtl_dump_file,
2751 "\n%d possible IF blocks searched.\n",
2752 num_possible_if_blocks);
2753 fprintf (rtl_dump_file,
2754 "%d IF blocks converted.\n",
2755 num_updated_if_blocks);
2756 fprintf (rtl_dump_file,
2757 "%d basic blocks deleted.\n\n\n",
2758 num_removed_blocks);
2761 #ifdef ENABLE_CHECKING
2762 verify_flow_info ();