1 /* If-conversion support.
2 Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
3 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
12 GCC is distributed in the hope that it will be useful, but WITHOUT
13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
15 License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
23 #include "coretypes.h"
30 #include "insn-config.h"
33 #include "hard-reg-set.h"
34 #include "basic-block.h"
44 #include "tree-pass.h"
50 #ifndef HAVE_conditional_execution
51 #define HAVE_conditional_execution 0
53 #ifndef HAVE_conditional_move
54 #define HAVE_conditional_move 0
66 #ifndef MAX_CONDITIONAL_EXECUTE
67 #define MAX_CONDITIONAL_EXECUTE \
68 (BRANCH_COST (optimize_function_for_speed_p (cfun), false) \
72 #define IFCVT_MULTIPLE_DUMPS 1
74 #define NULL_BLOCK ((basic_block) NULL)
76 /* # of IF-THEN or IF-THEN-ELSE blocks we looked at */
77 static int num_possible_if_blocks
;
79 /* # of IF-THEN or IF-THEN-ELSE blocks were converted to conditional
81 static int num_updated_if_blocks
;
83 /* # of changes made. */
84 static int num_true_changes
;
86 /* Whether conditional execution changes were made. */
87 static int cond_exec_changed_p
;
89 /* Forward references. */
90 static int count_bb_insns (const_basic_block
);
91 static bool cheap_bb_rtx_cost_p (const_basic_block
, int);
92 static rtx
first_active_insn (basic_block
);
93 static rtx
last_active_insn (basic_block
, int);
94 static basic_block
block_fallthru (basic_block
);
95 static int cond_exec_process_insns (ce_if_block_t
*, rtx
, rtx
, rtx
, rtx
, int);
96 static rtx
cond_exec_get_condition (rtx
);
97 static rtx
noce_get_condition (rtx
, rtx
*, bool);
98 static int noce_operand_ok (const_rtx
);
99 static void merge_if_block (ce_if_block_t
*);
100 static int find_cond_trap (basic_block
, edge
, edge
);
101 static basic_block
find_if_header (basic_block
, int);
102 static int block_jumps_and_fallthru_p (basic_block
, basic_block
);
103 static int noce_find_if_block (basic_block
, edge
, edge
, int);
104 static int cond_exec_find_if_block (ce_if_block_t
*);
105 static int find_if_case_1 (basic_block
, edge
, edge
);
106 static int find_if_case_2 (basic_block
, edge
, edge
);
107 static int find_memory (rtx
*, void *);
108 static int dead_or_predicable (basic_block
, basic_block
, basic_block
,
110 static void noce_emit_move_insn (rtx
, rtx
);
111 static rtx
block_has_only_trap (basic_block
);
113 /* Count the number of non-jump active insns in BB. */
116 count_bb_insns (const_basic_block bb
)
119 rtx insn
= BB_HEAD (bb
);
123 if (CALL_P (insn
) || NONJUMP_INSN_P (insn
))
126 if (insn
== BB_END (bb
))
128 insn
= NEXT_INSN (insn
);
134 /* Determine whether the total insn_rtx_cost on non-jump insns in
135 basic block BB is less than MAX_COST. This function returns
136 false if the cost of any instruction could not be estimated. */
139 cheap_bb_rtx_cost_p (const_basic_block bb
, int max_cost
)
142 rtx insn
= BB_HEAD (bb
);
143 bool speed
= optimize_bb_for_speed_p (bb
);
147 if (NONJUMP_INSN_P (insn
))
149 int cost
= insn_rtx_cost (PATTERN (insn
), speed
);
153 /* If this instruction is the load or set of a "stack" register,
154 such as a floating point register on x87, then the cost of
155 speculatively executing this insn may need to include
156 the additional cost of popping its result off of the
157 register stack. Unfortunately, correctly recognizing and
158 accounting for this additional overhead is tricky, so for
159 now we simply prohibit such speculative execution. */
162 rtx set
= single_set (insn
);
163 if (set
&& STACK_REG_P (SET_DEST (set
)))
169 if (count
>= max_cost
)
172 else if (CALL_P (insn
))
175 if (insn
== BB_END (bb
))
177 insn
= NEXT_INSN (insn
);
183 /* Return the first non-jump active insn in the basic block. */
186 first_active_insn (basic_block bb
)
188 rtx insn
= BB_HEAD (bb
);
192 if (insn
== BB_END (bb
))
194 insn
= NEXT_INSN (insn
);
197 while (NOTE_P (insn
) || DEBUG_INSN_P (insn
))
199 if (insn
== BB_END (bb
))
201 insn
= NEXT_INSN (insn
);
210 /* Return the last non-jump active (non-jump) insn in the basic block. */
213 last_active_insn (basic_block bb
, int skip_use_p
)
215 rtx insn
= BB_END (bb
);
216 rtx head
= BB_HEAD (bb
);
220 || DEBUG_INSN_P (insn
)
222 && NONJUMP_INSN_P (insn
)
223 && GET_CODE (PATTERN (insn
)) == USE
))
227 insn
= PREV_INSN (insn
);
236 /* Return the basic block reached by falling though the basic block BB. */
239 block_fallthru (basic_block bb
)
244 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
245 if (e
->flags
& EDGE_FALLTHRU
)
248 return (e
) ? e
->dest
: NULL_BLOCK
;
251 /* Go through a bunch of insns, converting them to conditional
252 execution format if possible. Return TRUE if all of the non-note
253 insns were processed. */
256 cond_exec_process_insns (ce_if_block_t
*ce_info ATTRIBUTE_UNUSED
,
257 /* if block information */rtx start
,
258 /* first insn to look at */rtx end
,
259 /* last insn to look at */rtx test
,
260 /* conditional execution test */rtx prob_val
,
261 /* probability of branch taken. */int mod_ok
)
263 int must_be_last
= FALSE
;
271 for (insn
= start
; ; insn
= NEXT_INSN (insn
))
273 if (NOTE_P (insn
) || DEBUG_INSN_P (insn
))
276 gcc_assert(NONJUMP_INSN_P (insn
) || CALL_P (insn
));
278 /* Remove USE insns that get in the way. */
279 if (reload_completed
&& GET_CODE (PATTERN (insn
)) == USE
)
281 /* ??? Ug. Actually unlinking the thing is problematic,
282 given what we'd have to coordinate with our callers. */
283 SET_INSN_DELETED (insn
);
287 /* Last insn wasn't last? */
291 if (modified_in_p (test
, insn
))
298 /* Now build the conditional form of the instruction. */
299 pattern
= PATTERN (insn
);
300 xtest
= copy_rtx (test
);
302 /* If this is already a COND_EXEC, rewrite the test to be an AND of the
304 if (GET_CODE (pattern
) == COND_EXEC
)
306 if (GET_MODE (xtest
) != GET_MODE (COND_EXEC_TEST (pattern
)))
309 xtest
= gen_rtx_AND (GET_MODE (xtest
), xtest
,
310 COND_EXEC_TEST (pattern
));
311 pattern
= COND_EXEC_CODE (pattern
);
314 pattern
= gen_rtx_COND_EXEC (VOIDmode
, xtest
, pattern
);
316 /* If the machine needs to modify the insn being conditionally executed,
317 say for example to force a constant integer operand into a temp
318 register, do so here. */
319 #ifdef IFCVT_MODIFY_INSN
320 IFCVT_MODIFY_INSN (ce_info
, pattern
, insn
);
325 validate_change (insn
, &PATTERN (insn
), pattern
, 1);
327 if (CALL_P (insn
) && prob_val
)
328 validate_change (insn
, ®_NOTES (insn
),
329 alloc_EXPR_LIST (REG_BR_PROB
, prob_val
,
330 REG_NOTES (insn
)), 1);
340 /* Return the condition for a jump. Do not do any special processing. */
343 cond_exec_get_condition (rtx jump
)
347 if (any_condjump_p (jump
))
348 test_if
= SET_SRC (pc_set (jump
));
351 cond
= XEXP (test_if
, 0);
353 /* If this branches to JUMP_LABEL when the condition is false,
354 reverse the condition. */
355 if (GET_CODE (XEXP (test_if
, 2)) == LABEL_REF
356 && XEXP (XEXP (test_if
, 2), 0) == JUMP_LABEL (jump
))
358 enum rtx_code rev
= reversed_comparison_code (cond
, jump
);
362 cond
= gen_rtx_fmt_ee (rev
, GET_MODE (cond
), XEXP (cond
, 0),
369 /* Given a simple IF-THEN or IF-THEN-ELSE block, attempt to convert it
370 to conditional execution. Return TRUE if we were successful at
371 converting the block. */
374 cond_exec_process_if_block (ce_if_block_t
* ce_info
,
375 /* if block information */int do_multiple_p
)
377 basic_block test_bb
= ce_info
->test_bb
; /* last test block */
378 basic_block then_bb
= ce_info
->then_bb
; /* THEN */
379 basic_block else_bb
= ce_info
->else_bb
; /* ELSE or NULL */
380 rtx test_expr
; /* expression in IF_THEN_ELSE that is tested */
381 rtx then_start
; /* first insn in THEN block */
382 rtx then_end
; /* last insn + 1 in THEN block */
383 rtx else_start
= NULL_RTX
; /* first insn in ELSE block or NULL */
384 rtx else_end
= NULL_RTX
; /* last insn + 1 in ELSE block */
385 int max
; /* max # of insns to convert. */
386 int then_mod_ok
; /* whether conditional mods are ok in THEN */
387 rtx true_expr
; /* test for else block insns */
388 rtx false_expr
; /* test for then block insns */
389 rtx true_prob_val
; /* probability of else block */
390 rtx false_prob_val
; /* probability of then block */
392 enum rtx_code false_code
;
394 /* If test is comprised of && or || elements, and we've failed at handling
395 all of them together, just use the last test if it is the special case of
396 && elements without an ELSE block. */
397 if (!do_multiple_p
&& ce_info
->num_multiple_test_blocks
)
399 if (else_bb
|| ! ce_info
->and_and_p
)
402 ce_info
->test_bb
= test_bb
= ce_info
->last_test_bb
;
403 ce_info
->num_multiple_test_blocks
= 0;
404 ce_info
->num_and_and_blocks
= 0;
405 ce_info
->num_or_or_blocks
= 0;
408 /* Find the conditional jump to the ELSE or JOIN part, and isolate
410 test_expr
= cond_exec_get_condition (BB_END (test_bb
));
414 /* If the conditional jump is more than just a conditional jump,
415 then we can not do conditional execution conversion on this block. */
416 if (! onlyjump_p (BB_END (test_bb
)))
419 /* Collect the bounds of where we're to search, skipping any labels, jumps
420 and notes at the beginning and end of the block. Then count the total
421 number of insns and see if it is small enough to convert. */
422 then_start
= first_active_insn (then_bb
);
423 then_end
= last_active_insn (then_bb
, TRUE
);
424 n_insns
= ce_info
->num_then_insns
= count_bb_insns (then_bb
);
425 max
= MAX_CONDITIONAL_EXECUTE
;
430 else_start
= first_active_insn (else_bb
);
431 else_end
= last_active_insn (else_bb
, TRUE
);
432 n_insns
+= ce_info
->num_else_insns
= count_bb_insns (else_bb
);
438 /* Map test_expr/test_jump into the appropriate MD tests to use on
439 the conditionally executed code. */
441 true_expr
= test_expr
;
443 false_code
= reversed_comparison_code (true_expr
, BB_END (test_bb
));
444 if (false_code
!= UNKNOWN
)
445 false_expr
= gen_rtx_fmt_ee (false_code
, GET_MODE (true_expr
),
446 XEXP (true_expr
, 0), XEXP (true_expr
, 1));
448 false_expr
= NULL_RTX
;
450 #ifdef IFCVT_MODIFY_TESTS
451 /* If the machine description needs to modify the tests, such as setting a
452 conditional execution register from a comparison, it can do so here. */
453 IFCVT_MODIFY_TESTS (ce_info
, true_expr
, false_expr
);
455 /* See if the conversion failed. */
456 if (!true_expr
|| !false_expr
)
460 true_prob_val
= find_reg_note (BB_END (test_bb
), REG_BR_PROB
, NULL_RTX
);
463 true_prob_val
= XEXP (true_prob_val
, 0);
464 false_prob_val
= GEN_INT (REG_BR_PROB_BASE
- INTVAL (true_prob_val
));
467 false_prob_val
= NULL_RTX
;
469 /* If we have && or || tests, do them here. These tests are in the adjacent
470 blocks after the first block containing the test. */
471 if (ce_info
->num_multiple_test_blocks
> 0)
473 basic_block bb
= test_bb
;
474 basic_block last_test_bb
= ce_info
->last_test_bb
;
483 enum rtx_code f_code
;
485 bb
= block_fallthru (bb
);
486 start
= first_active_insn (bb
);
487 end
= last_active_insn (bb
, TRUE
);
489 && ! cond_exec_process_insns (ce_info
, start
, end
, false_expr
,
490 false_prob_val
, FALSE
))
493 /* If the conditional jump is more than just a conditional jump, then
494 we can not do conditional execution conversion on this block. */
495 if (! onlyjump_p (BB_END (bb
)))
498 /* Find the conditional jump and isolate the test. */
499 t
= cond_exec_get_condition (BB_END (bb
));
503 f_code
= reversed_comparison_code (t
, BB_END (bb
));
504 if (f_code
== UNKNOWN
)
507 f
= gen_rtx_fmt_ee (f_code
, GET_MODE (t
), XEXP (t
, 0), XEXP (t
, 1));
508 if (ce_info
->and_and_p
)
510 t
= gen_rtx_AND (GET_MODE (t
), true_expr
, t
);
511 f
= gen_rtx_IOR (GET_MODE (t
), false_expr
, f
);
515 t
= gen_rtx_IOR (GET_MODE (t
), true_expr
, t
);
516 f
= gen_rtx_AND (GET_MODE (t
), false_expr
, f
);
519 /* If the machine description needs to modify the tests, such as
520 setting a conditional execution register from a comparison, it can
522 #ifdef IFCVT_MODIFY_MULTIPLE_TESTS
523 IFCVT_MODIFY_MULTIPLE_TESTS (ce_info
, bb
, t
, f
);
525 /* See if the conversion failed. */
533 while (bb
!= last_test_bb
);
536 /* For IF-THEN-ELSE blocks, we don't allow modifications of the test
537 on then THEN block. */
538 then_mod_ok
= (else_bb
== NULL_BLOCK
);
540 /* Go through the THEN and ELSE blocks converting the insns if possible
541 to conditional execution. */
545 || ! cond_exec_process_insns (ce_info
, then_start
, then_end
,
546 false_expr
, false_prob_val
,
550 if (else_bb
&& else_end
551 && ! cond_exec_process_insns (ce_info
, else_start
, else_end
,
552 true_expr
, true_prob_val
, TRUE
))
555 /* If we cannot apply the changes, fail. Do not go through the normal fail
556 processing, since apply_change_group will call cancel_changes. */
557 if (! apply_change_group ())
559 #ifdef IFCVT_MODIFY_CANCEL
560 /* Cancel any machine dependent changes. */
561 IFCVT_MODIFY_CANCEL (ce_info
);
566 #ifdef IFCVT_MODIFY_FINAL
567 /* Do any machine dependent final modifications. */
568 IFCVT_MODIFY_FINAL (ce_info
);
571 /* Conversion succeeded. */
573 fprintf (dump_file
, "%d insn%s converted to conditional execution.\n",
574 n_insns
, (n_insns
== 1) ? " was" : "s were");
576 /* Merge the blocks! */
577 merge_if_block (ce_info
);
578 cond_exec_changed_p
= TRUE
;
582 #ifdef IFCVT_MODIFY_CANCEL
583 /* Cancel any machine dependent changes. */
584 IFCVT_MODIFY_CANCEL (ce_info
);
591 /* Used by noce_process_if_block to communicate with its subroutines.
593 The subroutines know that A and B may be evaluated freely. They
594 know that X is a register. They should insert new instructions
595 before cond_earliest. */
599 /* The basic blocks that make up the IF-THEN-{ELSE-,}JOIN block. */
600 basic_block test_bb
, then_bb
, else_bb
, join_bb
;
602 /* The jump that ends TEST_BB. */
605 /* The jump condition. */
608 /* New insns should be inserted before this one. */
611 /* Insns in the THEN and ELSE block. There is always just this
612 one insns in those blocks. The insns are single_set insns.
613 If there was no ELSE block, INSN_B is the last insn before
614 COND_EARLIEST, or NULL_RTX. In the former case, the insn
615 operands are still valid, as if INSN_B was moved down below
619 /* The SET_SRC of INSN_A and INSN_B. */
622 /* The SET_DEST of INSN_A. */
625 /* True if this if block is not canonical. In the canonical form of
626 if blocks, the THEN_BB is the block reached via the fallthru edge
627 from TEST_BB. For the noce transformations, we allow the symmetric
629 bool then_else_reversed
;
631 /* Estimated cost of the particular branch instruction. */
635 static rtx
noce_emit_store_flag (struct noce_if_info
*, rtx
, int, int);
636 static int noce_try_move (struct noce_if_info
*);
637 static int noce_try_store_flag (struct noce_if_info
*);
638 static int noce_try_addcc (struct noce_if_info
*);
639 static int noce_try_store_flag_constants (struct noce_if_info
*);
640 static int noce_try_store_flag_mask (struct noce_if_info
*);
641 static rtx
noce_emit_cmove (struct noce_if_info
*, rtx
, enum rtx_code
, rtx
,
643 static int noce_try_cmove (struct noce_if_info
*);
644 static int noce_try_cmove_arith (struct noce_if_info
*);
645 static rtx
noce_get_alt_condition (struct noce_if_info
*, rtx
, rtx
*);
646 static int noce_try_minmax (struct noce_if_info
*);
647 static int noce_try_abs (struct noce_if_info
*);
648 static int noce_try_sign_mask (struct noce_if_info
*);
650 /* Helper function for noce_try_store_flag*. */
653 noce_emit_store_flag (struct noce_if_info
*if_info
, rtx x
, int reversep
,
656 rtx cond
= if_info
->cond
;
660 cond_complex
= (! general_operand (XEXP (cond
, 0), VOIDmode
)
661 || ! general_operand (XEXP (cond
, 1), VOIDmode
));
663 /* If earliest == jump, or when the condition is complex, try to
664 build the store_flag insn directly. */
668 rtx set
= pc_set (if_info
->jump
);
669 cond
= XEXP (SET_SRC (set
), 0);
670 if (GET_CODE (XEXP (SET_SRC (set
), 2)) == LABEL_REF
671 && XEXP (XEXP (SET_SRC (set
), 2), 0) == JUMP_LABEL (if_info
->jump
))
672 reversep
= !reversep
;
673 if (if_info
->then_else_reversed
)
674 reversep
= !reversep
;
678 code
= reversed_comparison_code (cond
, if_info
->jump
);
680 code
= GET_CODE (cond
);
682 if ((if_info
->cond_earliest
== if_info
->jump
|| cond_complex
)
683 && (normalize
== 0 || STORE_FLAG_VALUE
== normalize
))
687 tmp
= gen_rtx_fmt_ee (code
, GET_MODE (x
), XEXP (cond
, 0),
689 tmp
= gen_rtx_SET (VOIDmode
, x
, tmp
);
692 tmp
= emit_insn (tmp
);
694 if (recog_memoized (tmp
) >= 0)
700 if_info
->cond_earliest
= if_info
->jump
;
708 /* Don't even try if the comparison operands or the mode of X are weird. */
709 if (cond_complex
|| !SCALAR_INT_MODE_P (GET_MODE (x
)))
712 return emit_store_flag (x
, code
, XEXP (cond
, 0),
713 XEXP (cond
, 1), VOIDmode
,
714 (code
== LTU
|| code
== LEU
715 || code
== GEU
|| code
== GTU
), normalize
);
718 /* Emit instruction to move an rtx, possibly into STRICT_LOW_PART.
719 X is the destination/target and Y is the value to copy. */
722 noce_emit_move_insn (rtx x
, rtx y
)
724 enum machine_mode outmode
;
728 if (GET_CODE (x
) != STRICT_LOW_PART
)
730 rtx seq
, insn
, target
;
734 /* Check that the SET_SRC is reasonable before calling emit_move_insn,
735 otherwise construct a suitable SET pattern ourselves. */
736 insn
= (OBJECT_P (y
) || CONSTANT_P (y
) || GET_CODE (y
) == SUBREG
)
737 ? emit_move_insn (x
, y
)
738 : emit_insn (gen_rtx_SET (VOIDmode
, x
, y
));
742 if (recog_memoized (insn
) <= 0)
744 if (GET_CODE (x
) == ZERO_EXTRACT
)
746 rtx op
= XEXP (x
, 0);
747 unsigned HOST_WIDE_INT size
= INTVAL (XEXP (x
, 1));
748 unsigned HOST_WIDE_INT start
= INTVAL (XEXP (x
, 2));
750 /* store_bit_field expects START to be relative to
751 BYTES_BIG_ENDIAN and adjusts this value for machines with
752 BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN. In order to be able to
753 invoke store_bit_field again it is necessary to have the START
754 value from the first call. */
755 if (BITS_BIG_ENDIAN
!= BYTES_BIG_ENDIAN
)
758 start
= BITS_PER_UNIT
- start
- size
;
761 gcc_assert (REG_P (op
));
762 start
= BITS_PER_WORD
- start
- size
;
766 gcc_assert (start
< (MEM_P (op
) ? BITS_PER_UNIT
: BITS_PER_WORD
));
767 store_bit_field (op
, size
, start
, GET_MODE (x
), y
);
771 switch (GET_RTX_CLASS (GET_CODE (y
)))
774 ot
= code_to_optab
[GET_CODE (y
)];
778 target
= expand_unop (GET_MODE (y
), ot
, XEXP (y
, 0), x
, 0);
779 if (target
!= NULL_RTX
)
782 emit_move_insn (x
, target
);
791 ot
= code_to_optab
[GET_CODE (y
)];
795 target
= expand_binop (GET_MODE (y
), ot
,
796 XEXP (y
, 0), XEXP (y
, 1),
798 if (target
!= NULL_RTX
)
801 emit_move_insn (x
, target
);
818 inner
= XEXP (outer
, 0);
819 outmode
= GET_MODE (outer
);
820 bitpos
= SUBREG_BYTE (outer
) * BITS_PER_UNIT
;
821 store_bit_field (inner
, GET_MODE_BITSIZE (outmode
), bitpos
, outmode
, y
);
824 /* Return sequence of instructions generated by if conversion. This
825 function calls end_sequence() to end the current stream, ensures
826 that are instructions are unshared, recognizable non-jump insns.
827 On failure, this function returns a NULL_RTX. */
830 end_ifcvt_sequence (struct noce_if_info
*if_info
)
833 rtx seq
= get_insns ();
835 set_used_flags (if_info
->x
);
836 set_used_flags (if_info
->cond
);
837 unshare_all_rtl_in_chain (seq
);
840 /* Make sure that all of the instructions emitted are recognizable,
841 and that we haven't introduced a new jump instruction.
842 As an exercise for the reader, build a general mechanism that
843 allows proper placement of required clobbers. */
844 for (insn
= seq
; insn
; insn
= NEXT_INSN (insn
))
846 || recog_memoized (insn
) == -1)
852 /* Convert "if (a != b) x = a; else x = b" into "x = a" and
853 "if (a == b) x = a; else x = b" into "x = b". */
856 noce_try_move (struct noce_if_info
*if_info
)
858 rtx cond
= if_info
->cond
;
859 enum rtx_code code
= GET_CODE (cond
);
862 if (code
!= NE
&& code
!= EQ
)
865 /* This optimization isn't valid if either A or B could be a NaN
867 if (HONOR_NANS (GET_MODE (if_info
->x
))
868 || HONOR_SIGNED_ZEROS (GET_MODE (if_info
->x
)))
871 /* Check whether the operands of the comparison are A and in
873 if ((rtx_equal_p (if_info
->a
, XEXP (cond
, 0))
874 && rtx_equal_p (if_info
->b
, XEXP (cond
, 1)))
875 || (rtx_equal_p (if_info
->a
, XEXP (cond
, 1))
876 && rtx_equal_p (if_info
->b
, XEXP (cond
, 0))))
878 y
= (code
== EQ
) ? if_info
->a
: if_info
->b
;
880 /* Avoid generating the move if the source is the destination. */
881 if (! rtx_equal_p (if_info
->x
, y
))
884 noce_emit_move_insn (if_info
->x
, y
);
885 seq
= end_ifcvt_sequence (if_info
);
889 emit_insn_before_setloc (seq
, if_info
->jump
,
890 INSN_LOCATOR (if_info
->insn_a
));
897 /* Convert "if (test) x = 1; else x = 0".
899 Only try 0 and STORE_FLAG_VALUE here. Other combinations will be
900 tried in noce_try_store_flag_constants after noce_try_cmove has had
901 a go at the conversion. */
904 noce_try_store_flag (struct noce_if_info
*if_info
)
909 if (CONST_INT_P (if_info
->b
)
910 && INTVAL (if_info
->b
) == STORE_FLAG_VALUE
911 && if_info
->a
== const0_rtx
)
913 else if (if_info
->b
== const0_rtx
914 && CONST_INT_P (if_info
->a
)
915 && INTVAL (if_info
->a
) == STORE_FLAG_VALUE
916 && (reversed_comparison_code (if_info
->cond
, if_info
->jump
)
924 target
= noce_emit_store_flag (if_info
, if_info
->x
, reversep
, 0);
927 if (target
!= if_info
->x
)
928 noce_emit_move_insn (if_info
->x
, target
);
930 seq
= end_ifcvt_sequence (if_info
);
934 emit_insn_before_setloc (seq
, if_info
->jump
,
935 INSN_LOCATOR (if_info
->insn_a
));
945 /* Convert "if (test) x = a; else x = b", for A and B constant. */
948 noce_try_store_flag_constants (struct noce_if_info
*if_info
)
952 HOST_WIDE_INT itrue
, ifalse
, diff
, tmp
;
953 int normalize
, can_reverse
;
954 enum machine_mode mode
;
956 if (CONST_INT_P (if_info
->a
)
957 && CONST_INT_P (if_info
->b
))
959 mode
= GET_MODE (if_info
->x
);
960 ifalse
= INTVAL (if_info
->a
);
961 itrue
= INTVAL (if_info
->b
);
963 /* Make sure we can represent the difference between the two values. */
964 if ((itrue
- ifalse
> 0)
965 != ((ifalse
< 0) != (itrue
< 0) ? ifalse
< 0 : ifalse
< itrue
))
968 diff
= trunc_int_for_mode (itrue
- ifalse
, mode
);
970 can_reverse
= (reversed_comparison_code (if_info
->cond
, if_info
->jump
)
974 if (diff
== STORE_FLAG_VALUE
|| diff
== -STORE_FLAG_VALUE
)
976 else if (ifalse
== 0 && exact_log2 (itrue
) >= 0
977 && (STORE_FLAG_VALUE
== 1
978 || if_info
->branch_cost
>= 2))
980 else if (itrue
== 0 && exact_log2 (ifalse
) >= 0 && can_reverse
981 && (STORE_FLAG_VALUE
== 1 || if_info
->branch_cost
>= 2))
982 normalize
= 1, reversep
= 1;
984 && (STORE_FLAG_VALUE
== -1
985 || if_info
->branch_cost
>= 2))
987 else if (ifalse
== -1 && can_reverse
988 && (STORE_FLAG_VALUE
== -1 || if_info
->branch_cost
>= 2))
989 normalize
= -1, reversep
= 1;
990 else if ((if_info
->branch_cost
>= 2 && STORE_FLAG_VALUE
== -1)
991 || if_info
->branch_cost
>= 3)
998 tmp
= itrue
; itrue
= ifalse
; ifalse
= tmp
;
999 diff
= trunc_int_for_mode (-diff
, mode
);
1003 target
= noce_emit_store_flag (if_info
, if_info
->x
, reversep
, normalize
);
1010 /* if (test) x = 3; else x = 4;
1011 => x = 3 + (test == 0); */
1012 if (diff
== STORE_FLAG_VALUE
|| diff
== -STORE_FLAG_VALUE
)
1014 target
= expand_simple_binop (mode
,
1015 (diff
== STORE_FLAG_VALUE
1017 GEN_INT (ifalse
), target
, if_info
->x
, 0,
1021 /* if (test) x = 8; else x = 0;
1022 => x = (test != 0) << 3; */
1023 else if (ifalse
== 0 && (tmp
= exact_log2 (itrue
)) >= 0)
1025 target
= expand_simple_binop (mode
, ASHIFT
,
1026 target
, GEN_INT (tmp
), if_info
->x
, 0,
1030 /* if (test) x = -1; else x = b;
1031 => x = -(test != 0) | b; */
1032 else if (itrue
== -1)
1034 target
= expand_simple_binop (mode
, IOR
,
1035 target
, GEN_INT (ifalse
), if_info
->x
, 0,
1039 /* if (test) x = a; else x = b;
1040 => x = (-(test != 0) & (b - a)) + a; */
1043 target
= expand_simple_binop (mode
, AND
,
1044 target
, GEN_INT (diff
), if_info
->x
, 0,
1047 target
= expand_simple_binop (mode
, PLUS
,
1048 target
, GEN_INT (ifalse
),
1049 if_info
->x
, 0, OPTAB_WIDEN
);
1058 if (target
!= if_info
->x
)
1059 noce_emit_move_insn (if_info
->x
, target
);
1061 seq
= end_ifcvt_sequence (if_info
);
1065 emit_insn_before_setloc (seq
, if_info
->jump
,
1066 INSN_LOCATOR (if_info
->insn_a
));
1073 /* Convert "if (test) foo++" into "foo += (test != 0)", and
1074 similarly for "foo--". */
1077 noce_try_addcc (struct noce_if_info
*if_info
)
1080 int subtract
, normalize
;
1082 if (GET_CODE (if_info
->a
) == PLUS
1083 && rtx_equal_p (XEXP (if_info
->a
, 0), if_info
->b
)
1084 && (reversed_comparison_code (if_info
->cond
, if_info
->jump
)
1087 rtx cond
= if_info
->cond
;
1088 enum rtx_code code
= reversed_comparison_code (cond
, if_info
->jump
);
1090 /* First try to use addcc pattern. */
1091 if (general_operand (XEXP (cond
, 0), VOIDmode
)
1092 && general_operand (XEXP (cond
, 1), VOIDmode
))
1095 target
= emit_conditional_add (if_info
->x
, code
,
1100 XEXP (if_info
->a
, 1),
1101 GET_MODE (if_info
->x
),
1102 (code
== LTU
|| code
== GEU
1103 || code
== LEU
|| code
== GTU
));
1106 if (target
!= if_info
->x
)
1107 noce_emit_move_insn (if_info
->x
, target
);
1109 seq
= end_ifcvt_sequence (if_info
);
1113 emit_insn_before_setloc (seq
, if_info
->jump
,
1114 INSN_LOCATOR (if_info
->insn_a
));
1120 /* If that fails, construct conditional increment or decrement using
1122 if (if_info
->branch_cost
>= 2
1123 && (XEXP (if_info
->a
, 1) == const1_rtx
1124 || XEXP (if_info
->a
, 1) == constm1_rtx
))
1127 if (STORE_FLAG_VALUE
== INTVAL (XEXP (if_info
->a
, 1)))
1128 subtract
= 0, normalize
= 0;
1129 else if (-STORE_FLAG_VALUE
== INTVAL (XEXP (if_info
->a
, 1)))
1130 subtract
= 1, normalize
= 0;
1132 subtract
= 0, normalize
= INTVAL (XEXP (if_info
->a
, 1));
1135 target
= noce_emit_store_flag (if_info
,
1136 gen_reg_rtx (GET_MODE (if_info
->x
)),
1140 target
= expand_simple_binop (GET_MODE (if_info
->x
),
1141 subtract
? MINUS
: PLUS
,
1142 if_info
->b
, target
, if_info
->x
,
1146 if (target
!= if_info
->x
)
1147 noce_emit_move_insn (if_info
->x
, target
);
1149 seq
= end_ifcvt_sequence (if_info
);
1153 emit_insn_before_setloc (seq
, if_info
->jump
,
1154 INSN_LOCATOR (if_info
->insn_a
));
1164 /* Convert "if (test) x = 0;" to "x &= -(test == 0);" */
1167 noce_try_store_flag_mask (struct noce_if_info
*if_info
)
1173 if ((if_info
->branch_cost
>= 2
1174 || STORE_FLAG_VALUE
== -1)
1175 && ((if_info
->a
== const0_rtx
1176 && rtx_equal_p (if_info
->b
, if_info
->x
))
1177 || ((reversep
= (reversed_comparison_code (if_info
->cond
,
1180 && if_info
->b
== const0_rtx
1181 && rtx_equal_p (if_info
->a
, if_info
->x
))))
1184 target
= noce_emit_store_flag (if_info
,
1185 gen_reg_rtx (GET_MODE (if_info
->x
)),
1188 target
= expand_simple_binop (GET_MODE (if_info
->x
), AND
,
1190 target
, if_info
->x
, 0,
1195 if (target
!= if_info
->x
)
1196 noce_emit_move_insn (if_info
->x
, target
);
1198 seq
= end_ifcvt_sequence (if_info
);
1202 emit_insn_before_setloc (seq
, if_info
->jump
,
1203 INSN_LOCATOR (if_info
->insn_a
));
1213 /* Helper function for noce_try_cmove and noce_try_cmove_arith. */
1216 noce_emit_cmove (struct noce_if_info
*if_info
, rtx x
, enum rtx_code code
,
1217 rtx cmp_a
, rtx cmp_b
, rtx vfalse
, rtx vtrue
)
1219 /* If earliest == jump, try to build the cmove insn directly.
1220 This is helpful when combine has created some complex condition
1221 (like for alpha's cmovlbs) that we can't hope to regenerate
1222 through the normal interface. */
1224 if (if_info
->cond_earliest
== if_info
->jump
)
1228 tmp
= gen_rtx_fmt_ee (code
, GET_MODE (if_info
->cond
), cmp_a
, cmp_b
);
1229 tmp
= gen_rtx_IF_THEN_ELSE (GET_MODE (x
), tmp
, vtrue
, vfalse
);
1230 tmp
= gen_rtx_SET (VOIDmode
, x
, tmp
);
1233 tmp
= emit_insn (tmp
);
1235 if (recog_memoized (tmp
) >= 0)
1247 /* Don't even try if the comparison operands are weird. */
1248 if (! general_operand (cmp_a
, GET_MODE (cmp_a
))
1249 || ! general_operand (cmp_b
, GET_MODE (cmp_b
)))
1252 #if HAVE_conditional_move
1253 return emit_conditional_move (x
, code
, cmp_a
, cmp_b
, VOIDmode
,
1254 vtrue
, vfalse
, GET_MODE (x
),
1255 (code
== LTU
|| code
== GEU
1256 || code
== LEU
|| code
== GTU
));
1258 /* We'll never get here, as noce_process_if_block doesn't call the
1259 functions involved. Ifdef code, however, should be discouraged
1260 because it leads to typos in the code not selected. However,
1261 emit_conditional_move won't exist either. */
1266 /* Try only simple constants and registers here. More complex cases
1267 are handled in noce_try_cmove_arith after noce_try_store_flag_arith
1268 has had a go at it. */
1271 noce_try_cmove (struct noce_if_info
*if_info
)
1276 if ((CONSTANT_P (if_info
->a
) || register_operand (if_info
->a
, VOIDmode
))
1277 && (CONSTANT_P (if_info
->b
) || register_operand (if_info
->b
, VOIDmode
)))
1281 code
= GET_CODE (if_info
->cond
);
1282 target
= noce_emit_cmove (if_info
, if_info
->x
, code
,
1283 XEXP (if_info
->cond
, 0),
1284 XEXP (if_info
->cond
, 1),
1285 if_info
->a
, if_info
->b
);
1289 if (target
!= if_info
->x
)
1290 noce_emit_move_insn (if_info
->x
, target
);
1292 seq
= end_ifcvt_sequence (if_info
);
1296 emit_insn_before_setloc (seq
, if_info
->jump
,
1297 INSN_LOCATOR (if_info
->insn_a
));
1310 /* Try more complex cases involving conditional_move. */
1313 noce_try_cmove_arith (struct noce_if_info
*if_info
)
1325 /* A conditional move from two memory sources is equivalent to a
1326 conditional on their addresses followed by a load. Don't do this
1327 early because it'll screw alias analysis. Note that we've
1328 already checked for no side effects. */
1329 /* ??? FIXME: Magic number 5. */
1330 if (cse_not_expected
1331 && MEM_P (a
) && MEM_P (b
)
1332 && if_info
->branch_cost
>= 5)
1336 x
= gen_reg_rtx (Pmode
);
1340 /* ??? We could handle this if we knew that a load from A or B could
1341 not fault. This is also true if we've already loaded
1342 from the address along the path from ENTRY. */
1343 else if (may_trap_p (a
) || may_trap_p (b
))
1346 /* if (test) x = a + b; else x = c - d;
1353 code
= GET_CODE (if_info
->cond
);
1354 insn_a
= if_info
->insn_a
;
1355 insn_b
= if_info
->insn_b
;
1357 /* Total insn_rtx_cost should be smaller than branch cost. Exit
1358 if insn_rtx_cost can't be estimated. */
1361 insn_cost
= insn_rtx_cost (PATTERN (insn_a
),
1362 optimize_bb_for_speed_p (BLOCK_FOR_INSN (insn_a
)));
1363 if (insn_cost
== 0 || insn_cost
> COSTS_N_INSNS (if_info
->branch_cost
))
1371 insn_cost
+= insn_rtx_cost (PATTERN (insn_b
),
1372 optimize_bb_for_speed_p (BLOCK_FOR_INSN (insn_b
)));
1373 if (insn_cost
== 0 || insn_cost
> COSTS_N_INSNS (if_info
->branch_cost
))
1377 /* Possibly rearrange operands to make things come out more natural. */
1378 if (reversed_comparison_code (if_info
->cond
, if_info
->jump
) != UNKNOWN
)
1381 if (rtx_equal_p (b
, x
))
1383 else if (general_operand (b
, GET_MODE (b
)))
1388 code
= reversed_comparison_code (if_info
->cond
, if_info
->jump
);
1389 tmp
= a
, a
= b
, b
= tmp
;
1390 tmp
= insn_a
, insn_a
= insn_b
, insn_b
= tmp
;
1399 /* If either operand is complex, load it into a register first.
1400 The best way to do this is to copy the original insn. In this
1401 way we preserve any clobbers etc that the insn may have had.
1402 This is of course not possible in the IS_MEM case. */
1403 if (! general_operand (a
, GET_MODE (a
)))
1409 tmp
= gen_reg_rtx (GET_MODE (a
));
1410 tmp
= emit_insn (gen_rtx_SET (VOIDmode
, tmp
, a
));
1413 goto end_seq_and_fail
;
1416 a
= gen_reg_rtx (GET_MODE (a
));
1417 tmp
= copy_rtx (insn_a
);
1418 set
= single_set (tmp
);
1420 tmp
= emit_insn (PATTERN (tmp
));
1422 if (recog_memoized (tmp
) < 0)
1423 goto end_seq_and_fail
;
1425 if (! general_operand (b
, GET_MODE (b
)))
1431 tmp
= gen_reg_rtx (GET_MODE (b
));
1432 tmp
= gen_rtx_SET (VOIDmode
, tmp
, b
);
1435 goto end_seq_and_fail
;
1438 b
= gen_reg_rtx (GET_MODE (b
));
1439 tmp
= copy_rtx (insn_b
);
1440 set
= single_set (tmp
);
1442 tmp
= PATTERN (tmp
);
1445 /* If insn to set up A clobbers any registers B depends on, try to
1446 swap insn that sets up A with the one that sets up B. If even
1447 that doesn't help, punt. */
1448 last
= get_last_insn ();
1449 if (last
&& modified_in_p (orig_b
, last
))
1451 tmp
= emit_insn_before (tmp
, get_insns ());
1452 if (modified_in_p (orig_a
, tmp
))
1453 goto end_seq_and_fail
;
1456 tmp
= emit_insn (tmp
);
1458 if (recog_memoized (tmp
) < 0)
1459 goto end_seq_and_fail
;
1462 target
= noce_emit_cmove (if_info
, x
, code
, XEXP (if_info
->cond
, 0),
1463 XEXP (if_info
->cond
, 1), a
, b
);
1466 goto end_seq_and_fail
;
1468 /* If we're handling a memory for above, emit the load now. */
1471 tmp
= gen_rtx_MEM (GET_MODE (if_info
->x
), target
);
1473 /* Copy over flags as appropriate. */
1474 if (MEM_VOLATILE_P (if_info
->a
) || MEM_VOLATILE_P (if_info
->b
))
1475 MEM_VOLATILE_P (tmp
) = 1;
1476 if (MEM_IN_STRUCT_P (if_info
->a
) && MEM_IN_STRUCT_P (if_info
->b
))
1477 MEM_IN_STRUCT_P (tmp
) = 1;
1478 if (MEM_SCALAR_P (if_info
->a
) && MEM_SCALAR_P (if_info
->b
))
1479 MEM_SCALAR_P (tmp
) = 1;
1480 if (MEM_ALIAS_SET (if_info
->a
) == MEM_ALIAS_SET (if_info
->b
))
1481 set_mem_alias_set (tmp
, MEM_ALIAS_SET (if_info
->a
));
1483 MIN (MEM_ALIGN (if_info
->a
), MEM_ALIGN (if_info
->b
)));
1485 noce_emit_move_insn (if_info
->x
, tmp
);
1487 else if (target
!= x
)
1488 noce_emit_move_insn (x
, target
);
1490 tmp
= end_ifcvt_sequence (if_info
);
1494 emit_insn_before_setloc (tmp
, if_info
->jump
, INSN_LOCATOR (if_info
->insn_a
));
1502 /* For most cases, the simplified condition we found is the best
1503 choice, but this is not the case for the min/max/abs transforms.
1504 For these we wish to know that it is A or B in the condition. */
1507 noce_get_alt_condition (struct noce_if_info
*if_info
, rtx target
,
1510 rtx cond
, set
, insn
;
1513 /* If target is already mentioned in the known condition, return it. */
1514 if (reg_mentioned_p (target
, if_info
->cond
))
1516 *earliest
= if_info
->cond_earliest
;
1517 return if_info
->cond
;
1520 set
= pc_set (if_info
->jump
);
1521 cond
= XEXP (SET_SRC (set
), 0);
1523 = GET_CODE (XEXP (SET_SRC (set
), 2)) == LABEL_REF
1524 && XEXP (XEXP (SET_SRC (set
), 2), 0) == JUMP_LABEL (if_info
->jump
);
1525 if (if_info
->then_else_reversed
)
1528 /* If we're looking for a constant, try to make the conditional
1529 have that constant in it. There are two reasons why it may
1530 not have the constant we want:
1532 1. GCC may have needed to put the constant in a register, because
1533 the target can't compare directly against that constant. For
1534 this case, we look for a SET immediately before the comparison
1535 that puts a constant in that register.
1537 2. GCC may have canonicalized the conditional, for example
1538 replacing "if x < 4" with "if x <= 3". We can undo that (or
1539 make equivalent types of changes) to get the constants we need
1540 if they're off by one in the right direction. */
1542 if (CONST_INT_P (target
))
1544 enum rtx_code code
= GET_CODE (if_info
->cond
);
1545 rtx op_a
= XEXP (if_info
->cond
, 0);
1546 rtx op_b
= XEXP (if_info
->cond
, 1);
1549 /* First, look to see if we put a constant in a register. */
1550 prev_insn
= prev_nonnote_insn (if_info
->cond_earliest
);
1552 && BLOCK_NUM (prev_insn
) == BLOCK_NUM (if_info
->cond_earliest
)
1553 && INSN_P (prev_insn
)
1554 && GET_CODE (PATTERN (prev_insn
)) == SET
)
1556 rtx src
= find_reg_equal_equiv_note (prev_insn
);
1558 src
= SET_SRC (PATTERN (prev_insn
));
1559 if (CONST_INT_P (src
))
1561 if (rtx_equal_p (op_a
, SET_DEST (PATTERN (prev_insn
))))
1563 else if (rtx_equal_p (op_b
, SET_DEST (PATTERN (prev_insn
))))
1566 if (CONST_INT_P (op_a
))
1571 code
= swap_condition (code
);
1576 /* Now, look to see if we can get the right constant by
1577 adjusting the conditional. */
1578 if (CONST_INT_P (op_b
))
1580 HOST_WIDE_INT desired_val
= INTVAL (target
);
1581 HOST_WIDE_INT actual_val
= INTVAL (op_b
);
1586 if (actual_val
== desired_val
+ 1)
1589 op_b
= GEN_INT (desired_val
);
1593 if (actual_val
== desired_val
- 1)
1596 op_b
= GEN_INT (desired_val
);
1600 if (actual_val
== desired_val
- 1)
1603 op_b
= GEN_INT (desired_val
);
1607 if (actual_val
== desired_val
+ 1)
1610 op_b
= GEN_INT (desired_val
);
1618 /* If we made any changes, generate a new conditional that is
1619 equivalent to what we started with, but has the right
1621 if (code
!= GET_CODE (if_info
->cond
)
1622 || op_a
!= XEXP (if_info
->cond
, 0)
1623 || op_b
!= XEXP (if_info
->cond
, 1))
1625 cond
= gen_rtx_fmt_ee (code
, GET_MODE (cond
), op_a
, op_b
);
1626 *earliest
= if_info
->cond_earliest
;
1631 cond
= canonicalize_condition (if_info
->jump
, cond
, reverse
,
1632 earliest
, target
, false, true);
1633 if (! cond
|| ! reg_mentioned_p (target
, cond
))
1636 /* We almost certainly searched back to a different place.
1637 Need to re-verify correct lifetimes. */
1639 /* X may not be mentioned in the range (cond_earliest, jump]. */
1640 for (insn
= if_info
->jump
; insn
!= *earliest
; insn
= PREV_INSN (insn
))
1641 if (INSN_P (insn
) && reg_overlap_mentioned_p (if_info
->x
, PATTERN (insn
)))
1644 /* A and B may not be modified in the range [cond_earliest, jump). */
1645 for (insn
= *earliest
; insn
!= if_info
->jump
; insn
= NEXT_INSN (insn
))
1647 && (modified_in_p (if_info
->a
, insn
)
1648 || modified_in_p (if_info
->b
, insn
)))
1654 /* Convert "if (a < b) x = a; else x = b;" to "x = min(a, b);", etc. */
1657 noce_try_minmax (struct noce_if_info
*if_info
)
1659 rtx cond
, earliest
, target
, seq
;
1660 enum rtx_code code
, op
;
1663 /* ??? Reject modes with NaNs or signed zeros since we don't know how
1664 they will be resolved with an SMIN/SMAX. It wouldn't be too hard
1665 to get the target to tell us... */
1666 if (HONOR_SIGNED_ZEROS (GET_MODE (if_info
->x
))
1667 || HONOR_NANS (GET_MODE (if_info
->x
)))
1670 cond
= noce_get_alt_condition (if_info
, if_info
->a
, &earliest
);
1674 /* Verify the condition is of the form we expect, and canonicalize
1675 the comparison code. */
1676 code
= GET_CODE (cond
);
1677 if (rtx_equal_p (XEXP (cond
, 0), if_info
->a
))
1679 if (! rtx_equal_p (XEXP (cond
, 1), if_info
->b
))
1682 else if (rtx_equal_p (XEXP (cond
, 1), if_info
->a
))
1684 if (! rtx_equal_p (XEXP (cond
, 0), if_info
->b
))
1686 code
= swap_condition (code
);
1691 /* Determine what sort of operation this is. Note that the code is for
1692 a taken branch, so the code->operation mapping appears backwards. */
1725 target
= expand_simple_binop (GET_MODE (if_info
->x
), op
,
1726 if_info
->a
, if_info
->b
,
1727 if_info
->x
, unsignedp
, OPTAB_WIDEN
);
1733 if (target
!= if_info
->x
)
1734 noce_emit_move_insn (if_info
->x
, target
);
1736 seq
= end_ifcvt_sequence (if_info
);
1740 emit_insn_before_setloc (seq
, if_info
->jump
, INSN_LOCATOR (if_info
->insn_a
));
1741 if_info
->cond
= cond
;
1742 if_info
->cond_earliest
= earliest
;
1747 /* Convert "if (a < 0) x = -a; else x = a;" to "x = abs(a);",
1748 "if (a < 0) x = ~a; else x = a;" to "x = one_cmpl_abs(a);",
1752 noce_try_abs (struct noce_if_info
*if_info
)
1754 rtx cond
, earliest
, target
, seq
, a
, b
, c
;
1756 bool one_cmpl
= false;
1758 /* Reject modes with signed zeros. */
1759 if (HONOR_SIGNED_ZEROS (GET_MODE (if_info
->x
)))
1762 /* Recognize A and B as constituting an ABS or NABS. The canonical
1763 form is a branch around the negation, taken when the object is the
1764 first operand of a comparison against 0 that evaluates to true. */
1767 if (GET_CODE (a
) == NEG
&& rtx_equal_p (XEXP (a
, 0), b
))
1769 else if (GET_CODE (b
) == NEG
&& rtx_equal_p (XEXP (b
, 0), a
))
1771 c
= a
; a
= b
; b
= c
;
1774 else if (GET_CODE (a
) == NOT
&& rtx_equal_p (XEXP (a
, 0), b
))
1779 else if (GET_CODE (b
) == NOT
&& rtx_equal_p (XEXP (b
, 0), a
))
1781 c
= a
; a
= b
; b
= c
;
1788 cond
= noce_get_alt_condition (if_info
, b
, &earliest
);
1792 /* Verify the condition is of the form we expect. */
1793 if (rtx_equal_p (XEXP (cond
, 0), b
))
1795 else if (rtx_equal_p (XEXP (cond
, 1), b
))
1803 /* Verify that C is zero. Search one step backward for a
1804 REG_EQUAL note or a simple source if necessary. */
1807 rtx set
, insn
= prev_nonnote_insn (earliest
);
1809 && BLOCK_NUM (insn
) == BLOCK_NUM (earliest
)
1810 && (set
= single_set (insn
))
1811 && rtx_equal_p (SET_DEST (set
), c
))
1813 rtx note
= find_reg_equal_equiv_note (insn
);
1823 && GET_CODE (XEXP (c
, 0)) == SYMBOL_REF
1824 && CONSTANT_POOL_ADDRESS_P (XEXP (c
, 0)))
1825 c
= get_pool_constant (XEXP (c
, 0));
1827 /* Work around funny ideas get_condition has wrt canonicalization.
1828 Note that these rtx constants are known to be CONST_INT, and
1829 therefore imply integer comparisons. */
1830 if (c
== constm1_rtx
&& GET_CODE (cond
) == GT
)
1832 else if (c
== const1_rtx
&& GET_CODE (cond
) == LT
)
1834 else if (c
!= CONST0_RTX (GET_MODE (b
)))
1837 /* Determine what sort of operation this is. */
1838 switch (GET_CODE (cond
))
1857 target
= expand_one_cmpl_abs_nojump (GET_MODE (if_info
->x
), b
,
1860 target
= expand_abs_nojump (GET_MODE (if_info
->x
), b
, if_info
->x
, 1);
1862 /* ??? It's a quandary whether cmove would be better here, especially
1863 for integers. Perhaps combine will clean things up. */
1864 if (target
&& negate
)
1867 target
= expand_simple_unop (GET_MODE (target
), NOT
, target
,
1870 target
= expand_simple_unop (GET_MODE (target
), NEG
, target
,
1880 if (target
!= if_info
->x
)
1881 noce_emit_move_insn (if_info
->x
, target
);
1883 seq
= end_ifcvt_sequence (if_info
);
1887 emit_insn_before_setloc (seq
, if_info
->jump
, INSN_LOCATOR (if_info
->insn_a
));
1888 if_info
->cond
= cond
;
1889 if_info
->cond_earliest
= earliest
;
1894 /* Convert "if (m < 0) x = b; else x = 0;" to "x = (m >> C) & b;". */
1897 noce_try_sign_mask (struct noce_if_info
*if_info
)
1899 rtx cond
, t
, m
, c
, seq
;
1900 enum machine_mode mode
;
1902 bool t_unconditional
;
1904 cond
= if_info
->cond
;
1905 code
= GET_CODE (cond
);
1910 if (if_info
->a
== const0_rtx
)
1912 if ((code
== LT
&& c
== const0_rtx
)
1913 || (code
== LE
&& c
== constm1_rtx
))
1916 else if (if_info
->b
== const0_rtx
)
1918 if ((code
== GE
&& c
== const0_rtx
)
1919 || (code
== GT
&& c
== constm1_rtx
))
1923 if (! t
|| side_effects_p (t
))
1926 /* We currently don't handle different modes. */
1927 mode
= GET_MODE (t
);
1928 if (GET_MODE (m
) != mode
)
1931 /* This is only profitable if T is unconditionally executed/evaluated in the
1932 original insn sequence or T is cheap. The former happens if B is the
1933 non-zero (T) value and if INSN_B was taken from TEST_BB, or there was no
1934 INSN_B which can happen for e.g. conditional stores to memory. For the
1935 cost computation use the block TEST_BB where the evaluation will end up
1936 after the transformation. */
1939 && (if_info
->insn_b
== NULL_RTX
1940 || BLOCK_FOR_INSN (if_info
->insn_b
) == if_info
->test_bb
));
1941 if (!(t_unconditional
1942 || (rtx_cost (t
, SET
, optimize_bb_for_speed_p (if_info
->test_bb
))
1943 < COSTS_N_INSNS (2))))
1947 /* Use emit_store_flag to generate "m < 0 ? -1 : 0" instead of expanding
1948 "(signed) m >> 31" directly. This benefits targets with specialized
1949 insns to obtain the signmask, but still uses ashr_optab otherwise. */
1950 m
= emit_store_flag (gen_reg_rtx (mode
), LT
, m
, const0_rtx
, mode
, 0, -1);
1951 t
= m
? expand_binop (mode
, and_optab
, m
, t
, NULL_RTX
, 0, OPTAB_DIRECT
)
1960 noce_emit_move_insn (if_info
->x
, t
);
1962 seq
= end_ifcvt_sequence (if_info
);
1966 emit_insn_before_setloc (seq
, if_info
->jump
, INSN_LOCATOR (if_info
->insn_a
));
1971 /* Optimize away "if (x & C) x |= C" and similar bit manipulation
1975 noce_try_bitop (struct noce_if_info
*if_info
)
1977 rtx cond
, x
, a
, result
, seq
;
1978 enum machine_mode mode
;
1983 cond
= if_info
->cond
;
1984 code
= GET_CODE (cond
);
1986 /* Check for no else condition. */
1987 if (! rtx_equal_p (x
, if_info
->b
))
1990 /* Check for a suitable condition. */
1991 if (code
!= NE
&& code
!= EQ
)
1993 if (XEXP (cond
, 1) != const0_rtx
)
1995 cond
= XEXP (cond
, 0);
1997 /* ??? We could also handle AND here. */
1998 if (GET_CODE (cond
) == ZERO_EXTRACT
)
2000 if (XEXP (cond
, 1) != const1_rtx
2001 || !CONST_INT_P (XEXP (cond
, 2))
2002 || ! rtx_equal_p (x
, XEXP (cond
, 0)))
2004 bitnum
= INTVAL (XEXP (cond
, 2));
2005 mode
= GET_MODE (x
);
2006 if (BITS_BIG_ENDIAN
)
2007 bitnum
= GET_MODE_BITSIZE (mode
) - 1 - bitnum
;
2008 if (bitnum
< 0 || bitnum
>= HOST_BITS_PER_WIDE_INT
)
2015 if (GET_CODE (a
) == IOR
|| GET_CODE (a
) == XOR
)
2017 /* Check for "if (X & C) x = x op C". */
2018 if (! rtx_equal_p (x
, XEXP (a
, 0))
2019 || !CONST_INT_P (XEXP (a
, 1))
2020 || (INTVAL (XEXP (a
, 1)) & GET_MODE_MASK (mode
))
2021 != (unsigned HOST_WIDE_INT
) 1 << bitnum
)
2024 /* if ((x & C) == 0) x |= C; is transformed to x |= C. */
2025 /* if ((x & C) != 0) x |= C; is transformed to nothing. */
2026 if (GET_CODE (a
) == IOR
)
2027 result
= (code
== NE
) ? a
: NULL_RTX
;
2028 else if (code
== NE
)
2030 /* if ((x & C) == 0) x ^= C; is transformed to x |= C. */
2031 result
= gen_int_mode ((HOST_WIDE_INT
) 1 << bitnum
, mode
);
2032 result
= simplify_gen_binary (IOR
, mode
, x
, result
);
2036 /* if ((x & C) != 0) x ^= C; is transformed to x &= ~C. */
2037 result
= gen_int_mode (~((HOST_WIDE_INT
) 1 << bitnum
), mode
);
2038 result
= simplify_gen_binary (AND
, mode
, x
, result
);
2041 else if (GET_CODE (a
) == AND
)
2043 /* Check for "if (X & C) x &= ~C". */
2044 if (! rtx_equal_p (x
, XEXP (a
, 0))
2045 || !CONST_INT_P (XEXP (a
, 1))
2046 || (INTVAL (XEXP (a
, 1)) & GET_MODE_MASK (mode
))
2047 != (~((HOST_WIDE_INT
) 1 << bitnum
) & GET_MODE_MASK (mode
)))
2050 /* if ((x & C) == 0) x &= ~C; is transformed to nothing. */
2051 /* if ((x & C) != 0) x &= ~C; is transformed to x &= ~C. */
2052 result
= (code
== EQ
) ? a
: NULL_RTX
;
2060 noce_emit_move_insn (x
, result
);
2061 seq
= end_ifcvt_sequence (if_info
);
2065 emit_insn_before_setloc (seq
, if_info
->jump
,
2066 INSN_LOCATOR (if_info
->insn_a
));
2072 /* Similar to get_condition, only the resulting condition must be
2073 valid at JUMP, instead of at EARLIEST.
2075 If THEN_ELSE_REVERSED is true, the fallthrough does not go to the
2076 THEN block of the caller, and we have to reverse the condition. */
2079 noce_get_condition (rtx jump
, rtx
*earliest
, bool then_else_reversed
)
2084 if (! any_condjump_p (jump
))
2087 set
= pc_set (jump
);
2089 /* If this branches to JUMP_LABEL when the condition is false,
2090 reverse the condition. */
2091 reverse
= (GET_CODE (XEXP (SET_SRC (set
), 2)) == LABEL_REF
2092 && XEXP (XEXP (SET_SRC (set
), 2), 0) == JUMP_LABEL (jump
));
2094 /* We may have to reverse because the caller's if block is not canonical,
2095 i.e. the THEN block isn't the fallthrough block for the TEST block
2096 (see find_if_header). */
2097 if (then_else_reversed
)
2100 /* If the condition variable is a register and is MODE_INT, accept it. */
2102 cond
= XEXP (SET_SRC (set
), 0);
2103 tmp
= XEXP (cond
, 0);
2104 if (REG_P (tmp
) && GET_MODE_CLASS (GET_MODE (tmp
)) == MODE_INT
)
2109 cond
= gen_rtx_fmt_ee (reverse_condition (GET_CODE (cond
)),
2110 GET_MODE (cond
), tmp
, XEXP (cond
, 1));
2114 /* Otherwise, fall back on canonicalize_condition to do the dirty
2115 work of manipulating MODE_CC values and COMPARE rtx codes. */
2116 return canonicalize_condition (jump
, cond
, reverse
, earliest
,
2117 NULL_RTX
, false, true);
2120 /* Return true if OP is ok for if-then-else processing. */
2123 noce_operand_ok (const_rtx op
)
2125 /* We special-case memories, so handle any of them with
2126 no address side effects. */
2128 return ! side_effects_p (XEXP (op
, 0));
2130 if (side_effects_p (op
))
2133 return ! may_trap_p (op
);
2136 /* Return true if a write into MEM may trap or fault. */
2139 noce_mem_write_may_trap_or_fault_p (const_rtx mem
)
2143 if (MEM_READONLY_P (mem
))
2146 if (may_trap_or_fault_p (mem
))
2149 addr
= XEXP (mem
, 0);
2151 /* Call target hook to avoid the effects of -fpic etc.... */
2152 addr
= targetm
.delegitimize_address (addr
);
2155 switch (GET_CODE (addr
))
2163 addr
= XEXP (addr
, 0);
2167 addr
= XEXP (addr
, 1);
2170 if (CONST_INT_P (XEXP (addr
, 1)))
2171 addr
= XEXP (addr
, 0);
2178 if (SYMBOL_REF_DECL (addr
)
2179 && decl_readonly_section (SYMBOL_REF_DECL (addr
), 0))
2189 /* Return whether we can use store speculation for MEM. TOP_BB is the
2190 basic block above the conditional block where we are considering
2191 doing the speculative store. We look for whether MEM is set
2192 unconditionally later in the function. */
2195 noce_can_store_speculate_p (basic_block top_bb
, const_rtx mem
)
2197 basic_block dominator
;
2199 for (dominator
= get_immediate_dominator (CDI_POST_DOMINATORS
, top_bb
);
2201 dominator
= get_immediate_dominator (CDI_POST_DOMINATORS
, dominator
))
2205 FOR_BB_INSNS (dominator
, insn
)
2207 /* If we see something that might be a memory barrier, we
2208 have to stop looking. Even if the MEM is set later in
2209 the function, we still don't want to set it
2210 unconditionally before the barrier. */
2212 && (volatile_insn_p (PATTERN (insn
))
2213 || (CALL_P (insn
) && (!RTL_CONST_CALL_P (insn
)))))
2216 if (memory_modified_in_insn_p (mem
, insn
))
2218 if (modified_in_p (XEXP (mem
, 0), insn
))
2227 /* Given a simple IF-THEN-JOIN or IF-THEN-ELSE-JOIN block, attempt to convert
2228 it without using conditional execution. Return TRUE if we were successful
2229 at converting the block. */
2232 noce_process_if_block (struct noce_if_info
*if_info
)
2234 basic_block test_bb
= if_info
->test_bb
; /* test block */
2235 basic_block then_bb
= if_info
->then_bb
; /* THEN */
2236 basic_block else_bb
= if_info
->else_bb
; /* ELSE or NULL */
2237 basic_block join_bb
= if_info
->join_bb
; /* JOIN */
2238 rtx jump
= if_info
->jump
;
2239 rtx cond
= if_info
->cond
;
2242 rtx orig_x
, x
, a
, b
;
2244 /* We're looking for patterns of the form
2246 (1) if (...) x = a; else x = b;
2247 (2) x = b; if (...) x = a;
2248 (3) if (...) x = a; // as if with an initial x = x.
2250 The later patterns require jumps to be more expensive.
2252 ??? For future expansion, look for multiple X in such patterns. */
2254 /* Look for one of the potential sets. */
2255 insn_a
= first_active_insn (then_bb
);
2257 || insn_a
!= last_active_insn (then_bb
, FALSE
)
2258 || (set_a
= single_set (insn_a
)) == NULL_RTX
)
2261 x
= SET_DEST (set_a
);
2262 a
= SET_SRC (set_a
);
2264 /* Look for the other potential set. Make sure we've got equivalent
2266 /* ??? This is overconservative. Storing to two different mems is
2267 as easy as conditionally computing the address. Storing to a
2268 single mem merely requires a scratch memory to use as one of the
2269 destination addresses; often the memory immediately below the
2270 stack pointer is available for this. */
2274 insn_b
= first_active_insn (else_bb
);
2276 || insn_b
!= last_active_insn (else_bb
, FALSE
)
2277 || (set_b
= single_set (insn_b
)) == NULL_RTX
2278 || ! rtx_equal_p (x
, SET_DEST (set_b
)))
2283 insn_b
= prev_nonnote_insn (if_info
->cond_earliest
);
2284 while (insn_b
&& DEBUG_INSN_P (insn_b
))
2285 insn_b
= prev_nonnote_insn (insn_b
);
2286 /* We're going to be moving the evaluation of B down from above
2287 COND_EARLIEST to JUMP. Make sure the relevant data is still
2290 || BLOCK_NUM (insn_b
) != BLOCK_NUM (if_info
->cond_earliest
)
2291 || !NONJUMP_INSN_P (insn_b
)
2292 || (set_b
= single_set (insn_b
)) == NULL_RTX
2293 || ! rtx_equal_p (x
, SET_DEST (set_b
))
2294 || ! noce_operand_ok (SET_SRC (set_b
))
2295 || reg_overlap_mentioned_p (x
, SET_SRC (set_b
))
2296 || modified_between_p (SET_SRC (set_b
), insn_b
, jump
)
2297 /* Likewise with X. In particular this can happen when
2298 noce_get_condition looks farther back in the instruction
2299 stream than one might expect. */
2300 || reg_overlap_mentioned_p (x
, cond
)
2301 || reg_overlap_mentioned_p (x
, a
)
2302 || modified_between_p (x
, insn_b
, jump
))
2303 insn_b
= set_b
= NULL_RTX
;
2306 /* If x has side effects then only the if-then-else form is safe to
2307 convert. But even in that case we would need to restore any notes
2308 (such as REG_INC) at then end. That can be tricky if
2309 noce_emit_move_insn expands to more than one insn, so disable the
2310 optimization entirely for now if there are side effects. */
2311 if (side_effects_p (x
))
2314 b
= (set_b
? SET_SRC (set_b
) : x
);
2316 /* Only operate on register destinations, and even then avoid extending
2317 the lifetime of hard registers on small register class machines. */
2320 || (SMALL_REGISTER_CLASSES
2321 && REGNO (x
) < FIRST_PSEUDO_REGISTER
))
2323 if (GET_MODE (x
) == BLKmode
)
2326 if (GET_CODE (x
) == ZERO_EXTRACT
2327 && (!CONST_INT_P (XEXP (x
, 1))
2328 || !CONST_INT_P (XEXP (x
, 2))))
2331 x
= gen_reg_rtx (GET_MODE (GET_CODE (x
) == STRICT_LOW_PART
2332 ? XEXP (x
, 0) : x
));
2335 /* Don't operate on sources that may trap or are volatile. */
2336 if (! noce_operand_ok (a
) || ! noce_operand_ok (b
))
2340 /* Set up the info block for our subroutines. */
2341 if_info
->insn_a
= insn_a
;
2342 if_info
->insn_b
= insn_b
;
2347 /* Try optimizations in some approximation of a useful order. */
2348 /* ??? Should first look to see if X is live incoming at all. If it
2349 isn't, we don't need anything but an unconditional set. */
2351 /* Look and see if A and B are really the same. Avoid creating silly
2352 cmove constructs that no one will fix up later. */
2353 if (rtx_equal_p (a
, b
))
2355 /* If we have an INSN_B, we don't have to create any new rtl. Just
2356 move the instruction that we already have. If we don't have an
2357 INSN_B, that means that A == X, and we've got a noop move. In
2358 that case don't do anything and let the code below delete INSN_A. */
2359 if (insn_b
&& else_bb
)
2363 if (else_bb
&& insn_b
== BB_END (else_bb
))
2364 BB_END (else_bb
) = PREV_INSN (insn_b
);
2365 reorder_insns (insn_b
, insn_b
, PREV_INSN (jump
));
2367 /* If there was a REG_EQUAL note, delete it since it may have been
2368 true due to this insn being after a jump. */
2369 if ((note
= find_reg_note (insn_b
, REG_EQUAL
, NULL_RTX
)) != 0)
2370 remove_note (insn_b
, note
);
2374 /* If we have "x = b; if (...) x = a;", and x has side-effects, then
2375 x must be executed twice. */
2376 else if (insn_b
&& side_effects_p (orig_x
))
2383 if (!set_b
&& MEM_P (orig_x
))
2385 /* Disallow the "if (...) x = a;" form (implicit "else x = x;")
2386 for optimizations if writing to x may trap or fault,
2387 i.e. it's a memory other than a static var or a stack slot,
2388 is misaligned on strict aligned machines or is read-only. If
2389 x is a read-only memory, then the program is valid only if we
2390 avoid the store into it. If there are stores on both the
2391 THEN and ELSE arms, then we can go ahead with the conversion;
2392 either the program is broken, or the condition is always
2393 false such that the other memory is selected. */
2394 if (noce_mem_write_may_trap_or_fault_p (orig_x
))
2397 /* Avoid store speculation: given "if (...) x = a" where x is a
2398 MEM, we only want to do the store if x is always set
2399 somewhere in the function. This avoids cases like
2400 if (pthread_mutex_trylock(mutex))
2402 where we only want global_variable to be changed if the mutex
2403 is held. FIXME: This should ideally be expressed directly in
2405 if (!noce_can_store_speculate_p (test_bb
, orig_x
))
2409 if (noce_try_move (if_info
))
2411 if (noce_try_store_flag (if_info
))
2413 if (noce_try_bitop (if_info
))
2415 if (noce_try_minmax (if_info
))
2417 if (noce_try_abs (if_info
))
2419 if (HAVE_conditional_move
2420 && noce_try_cmove (if_info
))
2422 if (! HAVE_conditional_execution
)
2424 if (noce_try_store_flag_constants (if_info
))
2426 if (noce_try_addcc (if_info
))
2428 if (noce_try_store_flag_mask (if_info
))
2430 if (HAVE_conditional_move
2431 && noce_try_cmove_arith (if_info
))
2433 if (noce_try_sign_mask (if_info
))
2437 if (!else_bb
&& set_b
)
2439 insn_b
= set_b
= NULL_RTX
;
2448 /* If we used a temporary, fix it up now. */
2454 noce_emit_move_insn (orig_x
, x
);
2456 set_used_flags (orig_x
);
2457 unshare_all_rtl_in_chain (seq
);
2460 emit_insn_before_setloc (seq
, BB_END (test_bb
), INSN_LOCATOR (insn_a
));
2463 /* The original THEN and ELSE blocks may now be removed. The test block
2464 must now jump to the join block. If the test block and the join block
2465 can be merged, do so. */
2468 delete_basic_block (else_bb
);
2472 remove_edge (find_edge (test_bb
, join_bb
));
2474 remove_edge (find_edge (then_bb
, join_bb
));
2475 redirect_edge_and_branch_force (single_succ_edge (test_bb
), join_bb
);
2476 delete_basic_block (then_bb
);
2479 if (can_merge_blocks_p (test_bb
, join_bb
))
2481 merge_blocks (test_bb
, join_bb
);
2485 num_updated_if_blocks
++;
2489 /* Check whether a block is suitable for conditional move conversion.
2490 Every insn must be a simple set of a register to a constant or a
2491 register. For each assignment, store the value in the array VALS,
2492 indexed by register number, then store the register number in
2493 REGS. COND is the condition we will test. */
2496 check_cond_move_block (basic_block bb
, rtx
*vals
, VEC (int, heap
) **regs
, rtx cond
)
2500 /* We can only handle simple jumps at the end of the basic block.
2501 It is almost impossible to update the CFG otherwise. */
2503 if (JUMP_P (insn
) && !onlyjump_p (insn
))
2506 FOR_BB_INSNS (bb
, insn
)
2510 if (!NONDEBUG_INSN_P (insn
) || JUMP_P (insn
))
2512 set
= single_set (insn
);
2516 dest
= SET_DEST (set
);
2517 src
= SET_SRC (set
);
2519 || (SMALL_REGISTER_CLASSES
&& HARD_REGISTER_P (dest
)))
2522 if (!CONSTANT_P (src
) && !register_operand (src
, VOIDmode
))
2525 if (side_effects_p (src
) || side_effects_p (dest
))
2528 if (may_trap_p (src
) || may_trap_p (dest
))
2531 /* Don't try to handle this if the source register was
2532 modified earlier in the block. */
2534 && vals
[REGNO (src
)] != NULL
)
2535 || (GET_CODE (src
) == SUBREG
&& REG_P (SUBREG_REG (src
))
2536 && vals
[REGNO (SUBREG_REG (src
))] != NULL
))
2539 /* Don't try to handle this if the destination register was
2540 modified earlier in the block. */
2541 if (vals
[REGNO (dest
)] != NULL
)
2544 /* Don't try to handle this if the condition uses the
2545 destination register. */
2546 if (reg_overlap_mentioned_p (dest
, cond
))
2549 /* Don't try to handle this if the source register is modified
2550 later in the block. */
2551 if (!CONSTANT_P (src
)
2552 && modified_between_p (src
, insn
, NEXT_INSN (BB_END (bb
))))
2555 vals
[REGNO (dest
)] = src
;
2557 VEC_safe_push (int, heap
, *regs
, REGNO (dest
));
2563 /* Given a basic block BB suitable for conditional move conversion,
2564 a condition COND, and arrays THEN_VALS and ELSE_VALS containing the
2565 register values depending on COND, emit the insns in the block as
2566 conditional moves. If ELSE_BLOCK is true, THEN_BB was already
2567 processed. The caller has started a sequence for the conversion.
2568 Return true if successful, false if something goes wrong. */
2571 cond_move_convert_if_block (struct noce_if_info
*if_infop
,
2572 basic_block bb
, rtx cond
,
2573 rtx
*then_vals
, rtx
*else_vals
,
2577 rtx insn
, cond_arg0
, cond_arg1
;
2579 code
= GET_CODE (cond
);
2580 cond_arg0
= XEXP (cond
, 0);
2581 cond_arg1
= XEXP (cond
, 1);
2583 FOR_BB_INSNS (bb
, insn
)
2585 rtx set
, target
, dest
, t
, e
;
2588 /* ??? Maybe emit conditional debug insn? */
2589 if (!NONDEBUG_INSN_P (insn
) || JUMP_P (insn
))
2591 set
= single_set (insn
);
2592 gcc_assert (set
&& REG_P (SET_DEST (set
)));
2594 dest
= SET_DEST (set
);
2595 regno
= REGNO (dest
);
2597 t
= then_vals
[regno
];
2598 e
= else_vals
[regno
];
2602 /* If this register was set in the then block, we already
2603 handled this case there. */
2616 target
= noce_emit_cmove (if_infop
, dest
, code
, cond_arg0
, cond_arg1
,
2622 noce_emit_move_insn (dest
, target
);
2628 /* Given a simple IF-THEN-JOIN or IF-THEN-ELSE-JOIN block, attempt to convert
2629 it using only conditional moves. Return TRUE if we were successful at
2630 converting the block. */
2633 cond_move_process_if_block (struct noce_if_info
*if_info
)
2635 basic_block test_bb
= if_info
->test_bb
;
2636 basic_block then_bb
= if_info
->then_bb
;
2637 basic_block else_bb
= if_info
->else_bb
;
2638 basic_block join_bb
= if_info
->join_bb
;
2639 rtx jump
= if_info
->jump
;
2640 rtx cond
= if_info
->cond
;
2642 int max_reg
, size
, c
, reg
;
2645 VEC (int, heap
) *then_regs
= NULL
;
2646 VEC (int, heap
) *else_regs
= NULL
;
2649 /* Build a mapping for each block to the value used for each
2651 max_reg
= max_reg_num ();
2652 size
= (max_reg
+ 1) * sizeof (rtx
);
2653 then_vals
= (rtx
*) alloca (size
);
2654 else_vals
= (rtx
*) alloca (size
);
2655 memset (then_vals
, 0, size
);
2656 memset (else_vals
, 0, size
);
2658 /* Make sure the blocks are suitable. */
2659 if (!check_cond_move_block (then_bb
, then_vals
, &then_regs
, cond
)
2660 || (else_bb
&& !check_cond_move_block (else_bb
, else_vals
, &else_regs
, cond
)))
2662 VEC_free (int, heap
, then_regs
);
2663 VEC_free (int, heap
, else_regs
);
2667 /* Make sure the blocks can be used together. If the same register
2668 is set in both blocks, and is not set to a constant in both
2669 cases, then both blocks must set it to the same register. We
2670 have already verified that if it is set to a register, that the
2671 source register does not change after the assignment. Also count
2672 the number of registers set in only one of the blocks. */
2674 for (i
= 0; VEC_iterate (int, then_regs
, i
, reg
); i
++)
2676 if (!then_vals
[reg
] && !else_vals
[reg
])
2679 if (!else_vals
[reg
])
2683 if (!CONSTANT_P (then_vals
[reg
])
2684 && !CONSTANT_P (else_vals
[reg
])
2685 && !rtx_equal_p (then_vals
[reg
], else_vals
[reg
]))
2687 VEC_free (int, heap
, then_regs
);
2688 VEC_free (int, heap
, else_regs
);
2694 /* Finish off c for MAX_CONDITIONAL_EXECUTE. */
2695 for (i
= 0; VEC_iterate (int, else_regs
, i
, reg
); ++i
)
2696 if (!then_vals
[reg
])
2699 /* Make sure it is reasonable to convert this block. What matters
2700 is the number of assignments currently made in only one of the
2701 branches, since if we convert we are going to always execute
2703 if (c
> MAX_CONDITIONAL_EXECUTE
)
2705 VEC_free (int, heap
, then_regs
);
2706 VEC_free (int, heap
, else_regs
);
2710 /* Try to emit the conditional moves. First do the then block,
2711 then do anything left in the else blocks. */
2713 if (!cond_move_convert_if_block (if_info
, then_bb
, cond
,
2714 then_vals
, else_vals
, false)
2716 && !cond_move_convert_if_block (if_info
, else_bb
, cond
,
2717 then_vals
, else_vals
, true)))
2720 VEC_free (int, heap
, then_regs
);
2721 VEC_free (int, heap
, else_regs
);
2724 seq
= end_ifcvt_sequence (if_info
);
2727 VEC_free (int, heap
, then_regs
);
2728 VEC_free (int, heap
, else_regs
);
2732 loc_insn
= first_active_insn (then_bb
);
2735 loc_insn
= first_active_insn (else_bb
);
2736 gcc_assert (loc_insn
);
2738 emit_insn_before_setloc (seq
, jump
, INSN_LOCATOR (loc_insn
));
2742 delete_basic_block (else_bb
);
2746 remove_edge (find_edge (test_bb
, join_bb
));
2748 remove_edge (find_edge (then_bb
, join_bb
));
2749 redirect_edge_and_branch_force (single_succ_edge (test_bb
), join_bb
);
2750 delete_basic_block (then_bb
);
2753 if (can_merge_blocks_p (test_bb
, join_bb
))
2755 merge_blocks (test_bb
, join_bb
);
2759 num_updated_if_blocks
++;
2761 VEC_free (int, heap
, then_regs
);
2762 VEC_free (int, heap
, else_regs
);
2767 /* Determine if a given basic block heads a simple IF-THEN-JOIN or an
2768 IF-THEN-ELSE-JOIN block.
2770 If so, we'll try to convert the insns to not require the branch,
2771 using only transformations that do not require conditional execution.
2773 Return TRUE if we were successful at converting the block. */
2776 noce_find_if_block (basic_block test_bb
,
2777 edge then_edge
, edge else_edge
,
2780 basic_block then_bb
, else_bb
, join_bb
;
2781 bool then_else_reversed
= false;
2784 struct noce_if_info if_info
;
2786 /* We only ever should get here before reload. */
2787 gcc_assert (!reload_completed
);
2789 /* Recognize an IF-THEN-ELSE-JOIN block. */
2790 if (single_pred_p (then_edge
->dest
)
2791 && single_succ_p (then_edge
->dest
)
2792 && single_pred_p (else_edge
->dest
)
2793 && single_succ_p (else_edge
->dest
)
2794 && single_succ (then_edge
->dest
) == single_succ (else_edge
->dest
))
2796 then_bb
= then_edge
->dest
;
2797 else_bb
= else_edge
->dest
;
2798 join_bb
= single_succ (then_bb
);
2800 /* Recognize an IF-THEN-JOIN block. */
2801 else if (single_pred_p (then_edge
->dest
)
2802 && single_succ_p (then_edge
->dest
)
2803 && single_succ (then_edge
->dest
) == else_edge
->dest
)
2805 then_bb
= then_edge
->dest
;
2806 else_bb
= NULL_BLOCK
;
2807 join_bb
= else_edge
->dest
;
2809 /* Recognize an IF-ELSE-JOIN block. We can have those because the order
2810 of basic blocks in cfglayout mode does not matter, so the fallthrough
2811 edge can go to any basic block (and not just to bb->next_bb, like in
2813 else if (single_pred_p (else_edge
->dest
)
2814 && single_succ_p (else_edge
->dest
)
2815 && single_succ (else_edge
->dest
) == then_edge
->dest
)
2817 /* The noce transformations do not apply to IF-ELSE-JOIN blocks.
2818 To make this work, we have to invert the THEN and ELSE blocks
2819 and reverse the jump condition. */
2820 then_bb
= else_edge
->dest
;
2821 else_bb
= NULL_BLOCK
;
2822 join_bb
= single_succ (then_bb
);
2823 then_else_reversed
= true;
2826 /* Not a form we can handle. */
2829 /* The edges of the THEN and ELSE blocks cannot have complex edges. */
2830 if (single_succ_edge (then_bb
)->flags
& EDGE_COMPLEX
)
2833 && single_succ_edge (else_bb
)->flags
& EDGE_COMPLEX
)
2836 num_possible_if_blocks
++;
2841 "\nIF-THEN%s-JOIN block found, pass %d, test %d, then %d",
2842 (else_bb
) ? "-ELSE" : "",
2843 pass
, test_bb
->index
, then_bb
->index
);
2846 fprintf (dump_file
, ", else %d", else_bb
->index
);
2848 fprintf (dump_file
, ", join %d\n", join_bb
->index
);
2851 /* If the conditional jump is more than just a conditional
2852 jump, then we can not do if-conversion on this block. */
2853 jump
= BB_END (test_bb
);
2854 if (! onlyjump_p (jump
))
2857 /* If this is not a standard conditional jump, we can't parse it. */
2858 cond
= noce_get_condition (jump
,
2860 then_else_reversed
);
2864 /* We must be comparing objects whose modes imply the size. */
2865 if (GET_MODE (XEXP (cond
, 0)) == BLKmode
)
2868 /* Initialize an IF_INFO struct to pass around. */
2869 memset (&if_info
, 0, sizeof if_info
);
2870 if_info
.test_bb
= test_bb
;
2871 if_info
.then_bb
= then_bb
;
2872 if_info
.else_bb
= else_bb
;
2873 if_info
.join_bb
= join_bb
;
2874 if_info
.cond
= cond
;
2875 if_info
.cond_earliest
= cond_earliest
;
2876 if_info
.jump
= jump
;
2877 if_info
.then_else_reversed
= then_else_reversed
;
2878 if_info
.branch_cost
= BRANCH_COST (optimize_bb_for_speed_p (test_bb
),
2879 predictable_edge_p (then_edge
));
2881 /* Do the real work. */
2883 if (noce_process_if_block (&if_info
))
2886 if (HAVE_conditional_move
2887 && cond_move_process_if_block (&if_info
))
2894 /* Merge the blocks and mark for local life update. */
2897 merge_if_block (struct ce_if_block
* ce_info
)
2899 basic_block test_bb
= ce_info
->test_bb
; /* last test block */
2900 basic_block then_bb
= ce_info
->then_bb
; /* THEN */
2901 basic_block else_bb
= ce_info
->else_bb
; /* ELSE or NULL */
2902 basic_block join_bb
= ce_info
->join_bb
; /* join block */
2903 basic_block combo_bb
;
2905 /* All block merging is done into the lower block numbers. */
2908 df_set_bb_dirty (test_bb
);
2910 /* Merge any basic blocks to handle && and || subtests. Each of
2911 the blocks are on the fallthru path from the predecessor block. */
2912 if (ce_info
->num_multiple_test_blocks
> 0)
2914 basic_block bb
= test_bb
;
2915 basic_block last_test_bb
= ce_info
->last_test_bb
;
2916 basic_block fallthru
= block_fallthru (bb
);
2921 fallthru
= block_fallthru (bb
);
2922 merge_blocks (combo_bb
, bb
);
2925 while (bb
!= last_test_bb
);
2928 /* Merge TEST block into THEN block. Normally the THEN block won't have a
2929 label, but it might if there were || tests. That label's count should be
2930 zero, and it normally should be removed. */
2934 merge_blocks (combo_bb
, then_bb
);
2938 /* The ELSE block, if it existed, had a label. That label count
2939 will almost always be zero, but odd things can happen when labels
2940 get their addresses taken. */
2943 merge_blocks (combo_bb
, else_bb
);
2947 /* If there was no join block reported, that means it was not adjacent
2948 to the others, and so we cannot merge them. */
2952 rtx last
= BB_END (combo_bb
);
2954 /* The outgoing edge for the current COMBO block should already
2955 be correct. Verify this. */
2956 if (EDGE_COUNT (combo_bb
->succs
) == 0)
2957 gcc_assert (find_reg_note (last
, REG_NORETURN
, NULL
)
2958 || (NONJUMP_INSN_P (last
)
2959 && GET_CODE (PATTERN (last
)) == TRAP_IF
2960 && (TRAP_CONDITION (PATTERN (last
))
2961 == const_true_rtx
)));
2964 /* There should still be something at the end of the THEN or ELSE
2965 blocks taking us to our final destination. */
2966 gcc_assert (JUMP_P (last
)
2967 || (EDGE_SUCC (combo_bb
, 0)->dest
== EXIT_BLOCK_PTR
2969 && SIBLING_CALL_P (last
))
2970 || ((EDGE_SUCC (combo_bb
, 0)->flags
& EDGE_EH
)
2971 && can_throw_internal (last
)));
2974 /* The JOIN block may have had quite a number of other predecessors too.
2975 Since we've already merged the TEST, THEN and ELSE blocks, we should
2976 have only one remaining edge from our if-then-else diamond. If there
2977 is more than one remaining edge, it must come from elsewhere. There
2978 may be zero incoming edges if the THEN block didn't actually join
2979 back up (as with a call to a non-return function). */
2980 else if (EDGE_COUNT (join_bb
->preds
) < 2
2981 && join_bb
!= EXIT_BLOCK_PTR
)
2983 /* We can merge the JOIN cleanly and update the dataflow try
2984 again on this pass.*/
2985 merge_blocks (combo_bb
, join_bb
);
2990 /* We cannot merge the JOIN. */
2992 /* The outgoing edge for the current COMBO block should already
2993 be correct. Verify this. */
2994 gcc_assert (single_succ_p (combo_bb
)
2995 && single_succ (combo_bb
) == join_bb
);
2997 /* Remove the jump and cruft from the end of the COMBO block. */
2998 if (join_bb
!= EXIT_BLOCK_PTR
)
2999 tidy_fallthru_edge (single_succ_edge (combo_bb
));
3002 num_updated_if_blocks
++;
3005 /* Find a block ending in a simple IF condition and try to transform it
3006 in some way. When converting a multi-block condition, put the new code
3007 in the first such block and delete the rest. Return a pointer to this
3008 first block if some transformation was done. Return NULL otherwise. */
3011 find_if_header (basic_block test_bb
, int pass
)
3013 ce_if_block_t ce_info
;
3017 /* The kind of block we're looking for has exactly two successors. */
3018 if (EDGE_COUNT (test_bb
->succs
) != 2)
3021 then_edge
= EDGE_SUCC (test_bb
, 0);
3022 else_edge
= EDGE_SUCC (test_bb
, 1);
3024 if (df_get_bb_dirty (then_edge
->dest
))
3026 if (df_get_bb_dirty (else_edge
->dest
))
3029 /* Neither edge should be abnormal. */
3030 if ((then_edge
->flags
& EDGE_COMPLEX
)
3031 || (else_edge
->flags
& EDGE_COMPLEX
))
3034 /* Nor exit the loop. */
3035 if ((then_edge
->flags
& EDGE_LOOP_EXIT
)
3036 || (else_edge
->flags
& EDGE_LOOP_EXIT
))
3039 /* The THEN edge is canonically the one that falls through. */
3040 if (then_edge
->flags
& EDGE_FALLTHRU
)
3042 else if (else_edge
->flags
& EDGE_FALLTHRU
)
3045 else_edge
= then_edge
;
3049 /* Otherwise this must be a multiway branch of some sort. */
3052 memset (&ce_info
, '\0', sizeof (ce_info
));
3053 ce_info
.test_bb
= test_bb
;
3054 ce_info
.then_bb
= then_edge
->dest
;
3055 ce_info
.else_bb
= else_edge
->dest
;
3056 ce_info
.pass
= pass
;
3058 #ifdef IFCVT_INIT_EXTRA_FIELDS
3059 IFCVT_INIT_EXTRA_FIELDS (&ce_info
);
3062 if (! reload_completed
3063 && noce_find_if_block (test_bb
, then_edge
, else_edge
, pass
))
3066 if (HAVE_conditional_execution
&& reload_completed
3067 && cond_exec_find_if_block (&ce_info
))
3071 && optab_handler (ctrap_optab
, word_mode
)->insn_code
!= CODE_FOR_nothing
3072 && find_cond_trap (test_bb
, then_edge
, else_edge
))
3075 if (dom_info_state (CDI_POST_DOMINATORS
) >= DOM_NO_FAST_QUERY
3076 && (! HAVE_conditional_execution
|| reload_completed
))
3078 if (find_if_case_1 (test_bb
, then_edge
, else_edge
))
3080 if (find_if_case_2 (test_bb
, then_edge
, else_edge
))
3088 fprintf (dump_file
, "Conversion succeeded on pass %d.\n", pass
);
3089 /* Set this so we continue looking. */
3090 cond_exec_changed_p
= TRUE
;
3091 return ce_info
.test_bb
;
3094 /* Return true if a block has two edges, one of which falls through to the next
3095 block, and the other jumps to a specific block, so that we can tell if the
3096 block is part of an && test or an || test. Returns either -1 or the number
3097 of non-note, non-jump, non-USE/CLOBBER insns in the block. */
3100 block_jumps_and_fallthru_p (basic_block cur_bb
, basic_block target_bb
)
3103 int fallthru_p
= FALSE
;
3110 if (!cur_bb
|| !target_bb
)
3113 /* If no edges, obviously it doesn't jump or fallthru. */
3114 if (EDGE_COUNT (cur_bb
->succs
) == 0)
3117 FOR_EACH_EDGE (cur_edge
, ei
, cur_bb
->succs
)
3119 if (cur_edge
->flags
& EDGE_COMPLEX
)
3120 /* Anything complex isn't what we want. */
3123 else if (cur_edge
->flags
& EDGE_FALLTHRU
)
3126 else if (cur_edge
->dest
== target_bb
)
3133 if ((jump_p
& fallthru_p
) == 0)
3136 /* Don't allow calls in the block, since this is used to group && and ||
3137 together for conditional execution support. ??? we should support
3138 conditional execution support across calls for IA-64 some day, but
3139 for now it makes the code simpler. */
3140 end
= BB_END (cur_bb
);
3141 insn
= BB_HEAD (cur_bb
);
3143 while (insn
!= NULL_RTX
)
3150 && !DEBUG_INSN_P (insn
)
3151 && GET_CODE (PATTERN (insn
)) != USE
3152 && GET_CODE (PATTERN (insn
)) != CLOBBER
)
3158 insn
= NEXT_INSN (insn
);
3164 /* Determine if a given basic block heads a simple IF-THEN or IF-THEN-ELSE
3165 block. If so, we'll try to convert the insns to not require the branch.
3166 Return TRUE if we were successful at converting the block. */
3169 cond_exec_find_if_block (struct ce_if_block
* ce_info
)
3171 basic_block test_bb
= ce_info
->test_bb
;
3172 basic_block then_bb
= ce_info
->then_bb
;
3173 basic_block else_bb
= ce_info
->else_bb
;
3174 basic_block join_bb
= NULL_BLOCK
;
3179 ce_info
->last_test_bb
= test_bb
;
3181 /* We only ever should get here after reload,
3182 and only if we have conditional execution. */
3183 gcc_assert (HAVE_conditional_execution
&& reload_completed
);
3185 /* Discover if any fall through predecessors of the current test basic block
3186 were && tests (which jump to the else block) or || tests (which jump to
3188 if (single_pred_p (test_bb
)
3189 && single_pred_edge (test_bb
)->flags
== EDGE_FALLTHRU
)
3191 basic_block bb
= single_pred (test_bb
);
3192 basic_block target_bb
;
3193 int max_insns
= MAX_CONDITIONAL_EXECUTE
;
3196 /* Determine if the preceding block is an && or || block. */
3197 if ((n_insns
= block_jumps_and_fallthru_p (bb
, else_bb
)) >= 0)
3199 ce_info
->and_and_p
= TRUE
;
3200 target_bb
= else_bb
;
3202 else if ((n_insns
= block_jumps_and_fallthru_p (bb
, then_bb
)) >= 0)
3204 ce_info
->and_and_p
= FALSE
;
3205 target_bb
= then_bb
;
3208 target_bb
= NULL_BLOCK
;
3210 if (target_bb
&& n_insns
<= max_insns
)
3212 int total_insns
= 0;
3215 ce_info
->last_test_bb
= test_bb
;
3217 /* Found at least one && or || block, look for more. */
3220 ce_info
->test_bb
= test_bb
= bb
;
3221 total_insns
+= n_insns
;
3224 if (!single_pred_p (bb
))
3227 bb
= single_pred (bb
);
3228 n_insns
= block_jumps_and_fallthru_p (bb
, target_bb
);
3230 while (n_insns
>= 0 && (total_insns
+ n_insns
) <= max_insns
);
3232 ce_info
->num_multiple_test_blocks
= blocks
;
3233 ce_info
->num_multiple_test_insns
= total_insns
;
3235 if (ce_info
->and_and_p
)
3236 ce_info
->num_and_and_blocks
= blocks
;
3238 ce_info
->num_or_or_blocks
= blocks
;
3242 /* The THEN block of an IF-THEN combo must have exactly one predecessor,
3243 other than any || blocks which jump to the THEN block. */
3244 if ((EDGE_COUNT (then_bb
->preds
) - ce_info
->num_or_or_blocks
) != 1)
3247 /* The edges of the THEN and ELSE blocks cannot have complex edges. */
3248 FOR_EACH_EDGE (cur_edge
, ei
, then_bb
->preds
)
3250 if (cur_edge
->flags
& EDGE_COMPLEX
)
3254 FOR_EACH_EDGE (cur_edge
, ei
, else_bb
->preds
)
3256 if (cur_edge
->flags
& EDGE_COMPLEX
)
3260 /* The THEN block of an IF-THEN combo must have zero or one successors. */
3261 if (EDGE_COUNT (then_bb
->succs
) > 0
3262 && (!single_succ_p (then_bb
)
3263 || (single_succ_edge (then_bb
)->flags
& EDGE_COMPLEX
)
3264 || (epilogue_completed
&& tablejump_p (BB_END (then_bb
), NULL
, NULL
))))
3267 /* If the THEN block has no successors, conditional execution can still
3268 make a conditional call. Don't do this unless the ELSE block has
3269 only one incoming edge -- the CFG manipulation is too ugly otherwise.
3270 Check for the last insn of the THEN block being an indirect jump, which
3271 is listed as not having any successors, but confuses the rest of the CE
3272 code processing. ??? we should fix this in the future. */
3273 if (EDGE_COUNT (then_bb
->succs
) == 0)
3275 if (single_pred_p (else_bb
))
3277 rtx last_insn
= BB_END (then_bb
);
3280 && NOTE_P (last_insn
)
3281 && last_insn
!= BB_HEAD (then_bb
))
3282 last_insn
= PREV_INSN (last_insn
);
3285 && JUMP_P (last_insn
)
3286 && ! simplejump_p (last_insn
))
3290 else_bb
= NULL_BLOCK
;
3296 /* If the THEN block's successor is the other edge out of the TEST block,
3297 then we have an IF-THEN combo without an ELSE. */
3298 else if (single_succ (then_bb
) == else_bb
)
3301 else_bb
= NULL_BLOCK
;
3304 /* If the THEN and ELSE block meet in a subsequent block, and the ELSE
3305 has exactly one predecessor and one successor, and the outgoing edge
3306 is not complex, then we have an IF-THEN-ELSE combo. */
3307 else if (single_succ_p (else_bb
)
3308 && single_succ (then_bb
) == single_succ (else_bb
)
3309 && single_pred_p (else_bb
)
3310 && ! (single_succ_edge (else_bb
)->flags
& EDGE_COMPLEX
)
3311 && ! (epilogue_completed
&& tablejump_p (BB_END (else_bb
), NULL
, NULL
)))
3312 join_bb
= single_succ (else_bb
);
3314 /* Otherwise it is not an IF-THEN or IF-THEN-ELSE combination. */
3318 num_possible_if_blocks
++;
3323 "\nIF-THEN%s block found, pass %d, start block %d "
3324 "[insn %d], then %d [%d]",
3325 (else_bb
) ? "-ELSE" : "",
3328 BB_HEAD (test_bb
) ? (int)INSN_UID (BB_HEAD (test_bb
)) : -1,
3330 BB_HEAD (then_bb
) ? (int)INSN_UID (BB_HEAD (then_bb
)) : -1);
3333 fprintf (dump_file
, ", else %d [%d]",
3335 BB_HEAD (else_bb
) ? (int)INSN_UID (BB_HEAD (else_bb
)) : -1);
3337 fprintf (dump_file
, ", join %d [%d]",
3339 BB_HEAD (join_bb
) ? (int)INSN_UID (BB_HEAD (join_bb
)) : -1);
3341 if (ce_info
->num_multiple_test_blocks
> 0)
3342 fprintf (dump_file
, ", %d %s block%s last test %d [%d]",
3343 ce_info
->num_multiple_test_blocks
,
3344 (ce_info
->and_and_p
) ? "&&" : "||",
3345 (ce_info
->num_multiple_test_blocks
== 1) ? "" : "s",
3346 ce_info
->last_test_bb
->index
,
3347 ((BB_HEAD (ce_info
->last_test_bb
))
3348 ? (int)INSN_UID (BB_HEAD (ce_info
->last_test_bb
))
3351 fputc ('\n', dump_file
);
3354 /* Make sure IF, THEN, and ELSE, blocks are adjacent. Actually, we get the
3355 first condition for free, since we've already asserted that there's a
3356 fallthru edge from IF to THEN. Likewise for the && and || blocks, since
3357 we checked the FALLTHRU flag, those are already adjacent to the last IF
3359 /* ??? As an enhancement, move the ELSE block. Have to deal with
3360 BLOCK notes, if by no other means than backing out the merge if they
3361 exist. Sticky enough I don't want to think about it now. */
3363 if (else_bb
&& (next
= next
->next_bb
) != else_bb
)
3365 if ((next
= next
->next_bb
) != join_bb
&& join_bb
!= EXIT_BLOCK_PTR
)
3373 /* Do the real work. */
3375 ce_info
->else_bb
= else_bb
;
3376 ce_info
->join_bb
= join_bb
;
3378 /* If we have && and || tests, try to first handle combining the && and ||
3379 tests into the conditional code, and if that fails, go back and handle
3380 it without the && and ||, which at present handles the && case if there
3381 was no ELSE block. */
3382 if (cond_exec_process_if_block (ce_info
, TRUE
))
3385 if (ce_info
->num_multiple_test_blocks
)
3389 if (cond_exec_process_if_block (ce_info
, FALSE
))
3396 /* Convert a branch over a trap, or a branch
3397 to a trap, into a conditional trap. */
3400 find_cond_trap (basic_block test_bb
, edge then_edge
, edge else_edge
)
3402 basic_block then_bb
= then_edge
->dest
;
3403 basic_block else_bb
= else_edge
->dest
;
3404 basic_block other_bb
, trap_bb
;
3405 rtx trap
, jump
, cond
, cond_earliest
, seq
;
3408 /* Locate the block with the trap instruction. */
3409 /* ??? While we look for no successors, we really ought to allow
3410 EH successors. Need to fix merge_if_block for that to work. */
3411 if ((trap
= block_has_only_trap (then_bb
)) != NULL
)
3412 trap_bb
= then_bb
, other_bb
= else_bb
;
3413 else if ((trap
= block_has_only_trap (else_bb
)) != NULL
)
3414 trap_bb
= else_bb
, other_bb
= then_bb
;
3420 fprintf (dump_file
, "\nTRAP-IF block found, start %d, trap %d\n",
3421 test_bb
->index
, trap_bb
->index
);
3424 /* If this is not a standard conditional jump, we can't parse it. */
3425 jump
= BB_END (test_bb
);
3426 cond
= noce_get_condition (jump
, &cond_earliest
, false);
3430 /* If the conditional jump is more than just a conditional jump, then
3431 we can not do if-conversion on this block. */
3432 if (! onlyjump_p (jump
))
3435 /* We must be comparing objects whose modes imply the size. */
3436 if (GET_MODE (XEXP (cond
, 0)) == BLKmode
)
3439 /* Reverse the comparison code, if necessary. */
3440 code
= GET_CODE (cond
);
3441 if (then_bb
== trap_bb
)
3443 code
= reversed_comparison_code (cond
, jump
);
3444 if (code
== UNKNOWN
)
3448 /* Attempt to generate the conditional trap. */
3449 seq
= gen_cond_trap (code
, copy_rtx (XEXP (cond
, 0)),
3450 copy_rtx (XEXP (cond
, 1)),
3451 TRAP_CODE (PATTERN (trap
)));
3455 /* Emit the new insns before cond_earliest. */
3456 emit_insn_before_setloc (seq
, cond_earliest
, INSN_LOCATOR (trap
));
3458 /* Delete the trap block if possible. */
3459 remove_edge (trap_bb
== then_bb
? then_edge
: else_edge
);
3460 df_set_bb_dirty (test_bb
);
3461 df_set_bb_dirty (then_bb
);
3462 df_set_bb_dirty (else_bb
);
3464 if (EDGE_COUNT (trap_bb
->preds
) == 0)
3466 delete_basic_block (trap_bb
);
3470 /* Wire together the blocks again. */
3471 if (current_ir_type () == IR_RTL_CFGLAYOUT
)
3472 single_succ_edge (test_bb
)->flags
|= EDGE_FALLTHRU
;
3477 lab
= JUMP_LABEL (jump
);
3478 newjump
= emit_jump_insn_after (gen_jump (lab
), jump
);
3479 LABEL_NUSES (lab
) += 1;
3480 JUMP_LABEL (newjump
) = lab
;
3481 emit_barrier_after (newjump
);
3485 if (can_merge_blocks_p (test_bb
, other_bb
))
3487 merge_blocks (test_bb
, other_bb
);
3491 num_updated_if_blocks
++;
3495 /* Subroutine of find_cond_trap: if BB contains only a trap insn,
3499 block_has_only_trap (basic_block bb
)
3503 /* We're not the exit block. */
3504 if (bb
== EXIT_BLOCK_PTR
)
3507 /* The block must have no successors. */
3508 if (EDGE_COUNT (bb
->succs
) > 0)
3511 /* The only instruction in the THEN block must be the trap. */
3512 trap
= first_active_insn (bb
);
3513 if (! (trap
== BB_END (bb
)
3514 && GET_CODE (PATTERN (trap
)) == TRAP_IF
3515 && TRAP_CONDITION (PATTERN (trap
)) == const_true_rtx
))
3521 /* Look for IF-THEN-ELSE cases in which one of THEN or ELSE is
3522 transformable, but not necessarily the other. There need be no
3525 Return TRUE if we were successful at converting the block.
3527 Cases we'd like to look at:
3530 if (test) goto over; // x not live
3538 if (! test) goto label;
3541 if (test) goto E; // x not live
3555 (3) // This one's really only interesting for targets that can do
3556 // multiway branching, e.g. IA-64 BBB bundles. For other targets
3557 // it results in multiple branches on a cache line, which often
3558 // does not sit well with predictors.
3560 if (test1) goto E; // predicted not taken
3576 (A) Don't do (2) if the branch is predicted against the block we're
3577 eliminating. Do it anyway if we can eliminate a branch; this requires
3578 that the sole successor of the eliminated block postdominate the other
3581 (B) With CE, on (3) we can steal from both sides of the if, creating
3590 Again, this is most useful if J postdominates.
3592 (C) CE substitutes for helpful life information.
3594 (D) These heuristics need a lot of work. */
3596 /* Tests for case 1 above. */
3599 find_if_case_1 (basic_block test_bb
, edge then_edge
, edge else_edge
)
3601 basic_block then_bb
= then_edge
->dest
;
3602 basic_block else_bb
= else_edge
->dest
;
3606 /* If we are partitioning hot/cold basic blocks, we don't want to
3607 mess up unconditional or indirect jumps that cross between hot
3610 Basic block partitioning may result in some jumps that appear to
3611 be optimizable (or blocks that appear to be mergeable), but which really
3612 must be left untouched (they are required to make it safely across
3613 partition boundaries). See the comments at the top of
3614 bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */
3616 if ((BB_END (then_bb
)
3617 && find_reg_note (BB_END (then_bb
), REG_CROSSING_JUMP
, NULL_RTX
))
3618 || (BB_END (test_bb
)
3619 && find_reg_note (BB_END (test_bb
), REG_CROSSING_JUMP
, NULL_RTX
))
3620 || (BB_END (else_bb
)
3621 && find_reg_note (BB_END (else_bb
), REG_CROSSING_JUMP
,
3625 /* THEN has one successor. */
3626 if (!single_succ_p (then_bb
))
3629 /* THEN does not fall through, but is not strange either. */
3630 if (single_succ_edge (then_bb
)->flags
& (EDGE_COMPLEX
| EDGE_FALLTHRU
))
3633 /* THEN has one predecessor. */
3634 if (!single_pred_p (then_bb
))
3637 /* THEN must do something. */
3638 if (forwarder_block_p (then_bb
))
3641 num_possible_if_blocks
++;
3644 "\nIF-CASE-1 found, start %d, then %d\n",
3645 test_bb
->index
, then_bb
->index
);
3647 /* THEN is small. */
3648 if (! cheap_bb_rtx_cost_p (then_bb
,
3649 COSTS_N_INSNS (BRANCH_COST (optimize_bb_for_speed_p (then_edge
->src
),
3650 predictable_edge_p (then_edge
)))))
3653 /* Registers set are dead, or are predicable. */
3654 if (! dead_or_predicable (test_bb
, then_bb
, else_bb
,
3655 single_succ (then_bb
), 1))
3658 /* Conversion went ok, including moving the insns and fixing up the
3659 jump. Adjust the CFG to match. */
3661 /* We can avoid creating a new basic block if then_bb is immediately
3662 followed by else_bb, i.e. deleting then_bb allows test_bb to fall
3665 if (then_bb
->next_bb
== else_bb
3666 && then_bb
->prev_bb
== test_bb
3667 && else_bb
!= EXIT_BLOCK_PTR
)
3669 redirect_edge_succ (FALLTHRU_EDGE (test_bb
), else_bb
);
3673 new_bb
= redirect_edge_and_branch_force (FALLTHRU_EDGE (test_bb
),
3676 df_set_bb_dirty (test_bb
);
3677 df_set_bb_dirty (else_bb
);
3679 then_bb_index
= then_bb
->index
;
3680 delete_basic_block (then_bb
);
3682 /* Make rest of code believe that the newly created block is the THEN_BB
3683 block we removed. */
3686 df_bb_replace (then_bb_index
, new_bb
);
3687 /* Since the fallthru edge was redirected from test_bb to new_bb,
3688 we need to ensure that new_bb is in the same partition as
3689 test bb (you can not fall through across section boundaries). */
3690 BB_COPY_PARTITION (new_bb
, test_bb
);
3694 num_updated_if_blocks
++;
3699 /* Test for case 2 above. */
3702 find_if_case_2 (basic_block test_bb
, edge then_edge
, edge else_edge
)
3704 basic_block then_bb
= then_edge
->dest
;
3705 basic_block else_bb
= else_edge
->dest
;
3709 /* If we are partitioning hot/cold basic blocks, we don't want to
3710 mess up unconditional or indirect jumps that cross between hot
3713 Basic block partitioning may result in some jumps that appear to
3714 be optimizable (or blocks that appear to be mergeable), but which really
3715 must be left untouched (they are required to make it safely across
3716 partition boundaries). See the comments at the top of
3717 bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */
3719 if ((BB_END (then_bb
)
3720 && find_reg_note (BB_END (then_bb
), REG_CROSSING_JUMP
, NULL_RTX
))
3721 || (BB_END (test_bb
)
3722 && find_reg_note (BB_END (test_bb
), REG_CROSSING_JUMP
, NULL_RTX
))
3723 || (BB_END (else_bb
)
3724 && find_reg_note (BB_END (else_bb
), REG_CROSSING_JUMP
,
3728 /* ELSE has one successor. */
3729 if (!single_succ_p (else_bb
))
3732 else_succ
= single_succ_edge (else_bb
);
3734 /* ELSE outgoing edge is not complex. */
3735 if (else_succ
->flags
& EDGE_COMPLEX
)
3738 /* ELSE has one predecessor. */
3739 if (!single_pred_p (else_bb
))
3742 /* THEN is not EXIT. */
3743 if (then_bb
->index
< NUM_FIXED_BLOCKS
)
3746 /* ELSE is predicted or SUCC(ELSE) postdominates THEN. */
3747 note
= find_reg_note (BB_END (test_bb
), REG_BR_PROB
, NULL_RTX
);
3748 if (note
&& INTVAL (XEXP (note
, 0)) >= REG_BR_PROB_BASE
/ 2)
3750 else if (else_succ
->dest
->index
< NUM_FIXED_BLOCKS
3751 || dominated_by_p (CDI_POST_DOMINATORS
, then_bb
,
3757 num_possible_if_blocks
++;
3760 "\nIF-CASE-2 found, start %d, else %d\n",
3761 test_bb
->index
, else_bb
->index
);
3763 /* ELSE is small. */
3764 if (! cheap_bb_rtx_cost_p (else_bb
,
3765 COSTS_N_INSNS (BRANCH_COST (optimize_bb_for_speed_p (else_edge
->src
),
3766 predictable_edge_p (else_edge
)))))
3769 /* Registers set are dead, or are predicable. */
3770 if (! dead_or_predicable (test_bb
, else_bb
, then_bb
, else_succ
->dest
, 0))
3773 /* Conversion went ok, including moving the insns and fixing up the
3774 jump. Adjust the CFG to match. */
3776 df_set_bb_dirty (test_bb
);
3777 df_set_bb_dirty (then_bb
);
3778 delete_basic_block (else_bb
);
3781 num_updated_if_blocks
++;
3783 /* ??? We may now fallthru from one of THEN's successors into a join
3784 block. Rerun cleanup_cfg? Examine things manually? Wait? */
3789 /* A subroutine of dead_or_predicable called through for_each_rtx.
3790 Return 1 if a memory is found. */
3793 find_memory (rtx
*px
, void *data ATTRIBUTE_UNUSED
)
3798 /* Used by the code above to perform the actual rtl transformations.
3799 Return TRUE if successful.
3801 TEST_BB is the block containing the conditional branch. MERGE_BB
3802 is the block containing the code to manipulate. NEW_DEST is the
3803 label TEST_BB should be branching to after the conversion.
3804 REVERSEP is true if the sense of the branch should be reversed. */
3807 dead_or_predicable (basic_block test_bb
, basic_block merge_bb
,
3808 basic_block other_bb
, basic_block new_dest
, int reversep
)
3810 rtx head
, end
, jump
, earliest
= NULL_RTX
, old_dest
, new_label
= NULL_RTX
;
3811 /* Number of pending changes. */
3812 int n_validated_changes
= 0;
3814 jump
= BB_END (test_bb
);
3816 /* Find the extent of the real code in the merge block. */
3817 head
= BB_HEAD (merge_bb
);
3818 end
= BB_END (merge_bb
);
3820 while (DEBUG_INSN_P (end
) && end
!= head
)
3821 end
= PREV_INSN (end
);
3823 /* If merge_bb ends with a tablejump, predicating/moving insn's
3824 into test_bb and then deleting merge_bb will result in the jumptable
3825 that follows merge_bb being removed along with merge_bb and then we
3826 get an unresolved reference to the jumptable. */
3827 if (tablejump_p (end
, NULL
, NULL
))
3831 head
= NEXT_INSN (head
);
3832 while (DEBUG_INSN_P (head
) && head
!= end
)
3833 head
= NEXT_INSN (head
);
3838 head
= end
= NULL_RTX
;
3841 head
= NEXT_INSN (head
);
3842 while (DEBUG_INSN_P (head
) && head
!= end
)
3843 head
= NEXT_INSN (head
);
3850 head
= end
= NULL_RTX
;
3853 end
= PREV_INSN (end
);
3854 while (DEBUG_INSN_P (end
) && end
!= head
)
3855 end
= PREV_INSN (end
);
3858 /* Disable handling dead code by conditional execution if the machine needs
3859 to do anything funny with the tests, etc. */
3860 #ifndef IFCVT_MODIFY_TESTS
3861 if (HAVE_conditional_execution
)
3863 /* In the conditional execution case, we have things easy. We know
3864 the condition is reversible. We don't have to check life info
3865 because we're going to conditionally execute the code anyway.
3866 All that's left is making sure the insns involved can actually
3871 cond
= cond_exec_get_condition (jump
);
3875 prob_val
= find_reg_note (jump
, REG_BR_PROB
, NULL_RTX
);
3877 prob_val
= XEXP (prob_val
, 0);
3881 enum rtx_code rev
= reversed_comparison_code (cond
, jump
);
3884 cond
= gen_rtx_fmt_ee (rev
, GET_MODE (cond
), XEXP (cond
, 0),
3887 prob_val
= GEN_INT (REG_BR_PROB_BASE
- INTVAL (prob_val
));
3890 if (cond_exec_process_insns (NULL
, head
, end
, cond
, prob_val
, 0)
3891 && verify_changes (0))
3892 n_validated_changes
= num_validated_changes ();
3899 /* Try the NCE path if the CE path did not result in any changes. */
3900 if (n_validated_changes
== 0)
3902 /* In the non-conditional execution case, we have to verify that there
3903 are no trapping operations, no calls, no references to memory, and
3904 that any registers modified are dead at the branch site. */
3906 rtx insn
, cond
, prev
;
3907 bitmap merge_set
, test_live
, test_set
;
3908 unsigned i
, fail
= 0;
3911 /* Check for no calls or trapping operations. */
3912 for (insn
= head
; ; insn
= NEXT_INSN (insn
))
3916 if (NONDEBUG_INSN_P (insn
))
3918 if (may_trap_p (PATTERN (insn
)))
3921 /* ??? Even non-trapping memories such as stack frame
3922 references must be avoided. For stores, we collect
3923 no lifetime info; for reads, we'd have to assert
3924 true_dependence false against every store in the
3926 if (for_each_rtx (&PATTERN (insn
), find_memory
, NULL
))
3933 if (! any_condjump_p (jump
))
3936 /* Find the extent of the conditional. */
3937 cond
= noce_get_condition (jump
, &earliest
, false);
3942 MERGE_SET = set of registers set in MERGE_BB
3943 TEST_LIVE = set of registers live at EARLIEST
3944 TEST_SET = set of registers set between EARLIEST and the
3945 end of the block. */
3947 merge_set
= BITMAP_ALLOC (®_obstack
);
3948 test_live
= BITMAP_ALLOC (®_obstack
);
3949 test_set
= BITMAP_ALLOC (®_obstack
);
3951 /* ??? bb->local_set is only valid during calculate_global_regs_live,
3952 so we must recompute usage for MERGE_BB. Not so bad, I suppose,
3953 since we've already asserted that MERGE_BB is small. */
3954 /* If we allocated new pseudos (e.g. in the conditional move
3955 expander called from noce_emit_cmove), we must resize the
3957 if (max_regno
< max_reg_num ())
3958 max_regno
= max_reg_num ();
3960 FOR_BB_INSNS (merge_bb
, insn
)
3962 if (NONDEBUG_INSN_P (insn
))
3964 unsigned int uid
= INSN_UID (insn
);
3966 for (def_rec
= DF_INSN_UID_DEFS (uid
); *def_rec
; def_rec
++)
3968 df_ref def
= *def_rec
;
3969 bitmap_set_bit (merge_set
, DF_REF_REGNO (def
));
3974 /* For small register class machines, don't lengthen lifetimes of
3975 hard registers before reload. */
3976 if (SMALL_REGISTER_CLASSES
&& ! reload_completed
)
3978 EXECUTE_IF_SET_IN_BITMAP (merge_set
, 0, i
, bi
)
3980 if (i
< FIRST_PSEUDO_REGISTER
3982 && ! global_regs
[i
])
3987 /* For TEST, we're interested in a range of insns, not a whole block.
3988 Moreover, we're interested in the insns live from OTHER_BB. */
3990 /* The loop below takes the set of live registers
3991 after JUMP, and calculates the live set before EARLIEST. */
3992 bitmap_copy (test_live
, df_get_live_in (other_bb
));
3993 df_simulate_initialize_backwards (test_bb
, test_live
);
3994 for (insn
= jump
; ; insn
= prev
)
3998 df_simulate_find_defs (insn
, test_set
);
3999 df_simulate_one_insn_backwards (test_bb
, insn
, test_live
);
4001 prev
= PREV_INSN (insn
);
4002 if (insn
== earliest
)
4006 /* We can perform the transformation if
4007 MERGE_SET & (TEST_SET | TEST_LIVE)
4009 TEST_SET & DF_LIVE_IN (merge_bb)
4012 if (bitmap_intersect_p (test_set
, merge_set
)
4013 || bitmap_intersect_p (test_live
, merge_set
)
4014 || bitmap_intersect_p (test_set
, df_get_live_in (merge_bb
)))
4017 BITMAP_FREE (merge_set
);
4018 BITMAP_FREE (test_live
);
4019 BITMAP_FREE (test_set
);
4026 /* We don't want to use normal invert_jump or redirect_jump because
4027 we don't want to delete_insn called. Also, we want to do our own
4028 change group management. */
4030 old_dest
= JUMP_LABEL (jump
);
4031 if (other_bb
!= new_dest
)
4033 new_label
= block_label (new_dest
);
4035 ? ! invert_jump_1 (jump
, new_label
)
4036 : ! redirect_jump_1 (jump
, new_label
))
4040 if (verify_changes (n_validated_changes
))
4041 confirm_change_group ();
4045 if (other_bb
!= new_dest
)
4047 redirect_jump_2 (jump
, old_dest
, new_label
, 0, reversep
);
4049 redirect_edge_succ (BRANCH_EDGE (test_bb
), new_dest
);
4052 gcov_type count
, probability
;
4053 count
= BRANCH_EDGE (test_bb
)->count
;
4054 BRANCH_EDGE (test_bb
)->count
= FALLTHRU_EDGE (test_bb
)->count
;
4055 FALLTHRU_EDGE (test_bb
)->count
= count
;
4056 probability
= BRANCH_EDGE (test_bb
)->probability
;
4057 BRANCH_EDGE (test_bb
)->probability
4058 = FALLTHRU_EDGE (test_bb
)->probability
;
4059 FALLTHRU_EDGE (test_bb
)->probability
= probability
;
4060 update_br_prob_note (test_bb
);
4064 /* Move the insns out of MERGE_BB to before the branch. */
4069 if (end
== BB_END (merge_bb
))
4070 BB_END (merge_bb
) = PREV_INSN (head
);
4072 /* PR 21767: When moving insns above a conditional branch, REG_EQUAL
4073 notes might become invalid. */
4079 if (! INSN_P (insn
))
4081 note
= find_reg_note (insn
, REG_EQUAL
, NULL_RTX
);
4084 set
= single_set (insn
);
4085 if (!set
|| !function_invariant_p (SET_SRC (set
)))
4086 remove_note (insn
, note
);
4087 } while (insn
!= end
&& (insn
= NEXT_INSN (insn
)));
4089 reorder_insns (head
, end
, PREV_INSN (earliest
));
4092 /* Remove the jump and edge if we can. */
4093 if (other_bb
== new_dest
)
4096 remove_edge (BRANCH_EDGE (test_bb
));
4097 /* ??? Can't merge blocks here, as then_bb is still in use.
4098 At minimum, the merge will get done just before bb-reorder. */
4108 /* Main entry point for all if-conversion. */
4118 df_live_add_problem ();
4119 df_live_set_all_dirty ();
4122 num_possible_if_blocks
= 0;
4123 num_updated_if_blocks
= 0;
4124 num_true_changes
= 0;
4126 loop_optimizer_init (AVOID_CFG_MODIFICATIONS
);
4127 mark_loop_exit_edges ();
4128 loop_optimizer_finalize ();
4129 free_dominance_info (CDI_DOMINATORS
);
4131 /* Compute postdominators. */
4132 calculate_dominance_info (CDI_POST_DOMINATORS
);
4134 df_set_flags (DF_LR_RUN_DCE
);
4136 /* Go through each of the basic blocks looking for things to convert. If we
4137 have conditional execution, we make multiple passes to allow us to handle
4138 IF-THEN{-ELSE} blocks within other IF-THEN{-ELSE} blocks. */
4143 /* Only need to do dce on the first pass. */
4144 df_clear_flags (DF_LR_RUN_DCE
);
4145 cond_exec_changed_p
= FALSE
;
4148 #ifdef IFCVT_MULTIPLE_DUMPS
4149 if (dump_file
&& pass
> 1)
4150 fprintf (dump_file
, "\n\n========== Pass %d ==========\n", pass
);
4156 while (!df_get_bb_dirty (bb
)
4157 && (new_bb
= find_if_header (bb
, pass
)) != NULL
)
4161 #ifdef IFCVT_MULTIPLE_DUMPS
4162 if (dump_file
&& cond_exec_changed_p
)
4163 print_rtl_with_bb (dump_file
, get_insns ());
4166 while (cond_exec_changed_p
);
4168 #ifdef IFCVT_MULTIPLE_DUMPS
4170 fprintf (dump_file
, "\n\n========== no more changes\n");
4173 free_dominance_info (CDI_POST_DOMINATORS
);
4178 clear_aux_for_blocks ();
4180 /* If we allocated new pseudos, we must resize the array for sched1. */
4181 if (max_regno
< max_reg_num ())
4182 max_regno
= max_reg_num ();
4184 /* Write the final stats. */
4185 if (dump_file
&& num_possible_if_blocks
> 0)
4188 "\n%d possible IF blocks searched.\n",
4189 num_possible_if_blocks
);
4191 "%d IF blocks converted.\n",
4192 num_updated_if_blocks
);
4194 "%d true changes made.\n\n\n",
4199 df_remove_problem (df_live
);
4201 #ifdef ENABLE_CHECKING
4202 verify_flow_info ();
4207 gate_handle_if_conversion (void)
4209 return (optimize
> 0)
4210 && dbg_cnt (if_conversion
);
4213 /* If-conversion and CFG cleanup. */
4215 rest_of_handle_if_conversion (void)
4217 if (flag_if_conversion
)
4220 dump_flow_info (dump_file
, dump_flags
);
4221 cleanup_cfg (CLEANUP_EXPENSIVE
);
4229 struct rtl_opt_pass pass_rtl_ifcvt
=
4234 gate_handle_if_conversion
, /* gate */
4235 rest_of_handle_if_conversion
, /* execute */
4238 0, /* static_pass_number */
4239 TV_IFCVT
, /* tv_id */
4240 0, /* properties_required */
4241 0, /* properties_provided */
4242 0, /* properties_destroyed */
4243 0, /* todo_flags_start */
4244 TODO_df_finish
| TODO_verify_rtl_sharing
|
4245 TODO_dump_func
/* todo_flags_finish */
4250 gate_handle_if_after_combine (void)
4252 return optimize
> 0 && flag_if_conversion
4253 && dbg_cnt (if_after_combine
);
4257 /* Rerun if-conversion, as combine may have simplified things enough
4258 to now meet sequence length restrictions. */
4260 rest_of_handle_if_after_combine (void)
4266 struct rtl_opt_pass pass_if_after_combine
=
4271 gate_handle_if_after_combine
, /* gate */
4272 rest_of_handle_if_after_combine
, /* execute */
4275 0, /* static_pass_number */
4276 TV_IFCVT
, /* tv_id */
4277 0, /* properties_required */
4278 0, /* properties_provided */
4279 0, /* properties_destroyed */
4280 0, /* todo_flags_start */
4281 TODO_df_finish
| TODO_verify_rtl_sharing
|
4283 TODO_ggc_collect
/* todo_flags_finish */
4289 gate_handle_if_after_reload (void)
4291 return optimize
> 0 && flag_if_conversion2
4292 && dbg_cnt (if_after_reload
);
4296 rest_of_handle_if_after_reload (void)
4303 struct rtl_opt_pass pass_if_after_reload
=
4308 gate_handle_if_after_reload
, /* gate */
4309 rest_of_handle_if_after_reload
, /* execute */
4312 0, /* static_pass_number */
4313 TV_IFCVT2
, /* tv_id */
4314 0, /* properties_required */
4315 0, /* properties_provided */
4316 0, /* properties_destroyed */
4317 0, /* todo_flags_start */
4318 TODO_df_finish
| TODO_verify_rtl_sharing
|
4320 TODO_ggc_collect
/* todo_flags_finish */