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 && MEM_ADDR_SPACE (a
) == MEM_ADDR_SPACE (b
)
1333 && if_info
->branch_cost
>= 5)
1335 enum machine_mode address_mode
1336 = targetm
.addr_space
.address_mode (MEM_ADDR_SPACE (a
));
1340 x
= gen_reg_rtx (address_mode
);
1344 /* ??? We could handle this if we knew that a load from A or B could
1345 not fault. This is also true if we've already loaded
1346 from the address along the path from ENTRY. */
1347 else if (may_trap_p (a
) || may_trap_p (b
))
1350 /* if (test) x = a + b; else x = c - d;
1357 code
= GET_CODE (if_info
->cond
);
1358 insn_a
= if_info
->insn_a
;
1359 insn_b
= if_info
->insn_b
;
1361 /* Total insn_rtx_cost should be smaller than branch cost. Exit
1362 if insn_rtx_cost can't be estimated. */
1365 insn_cost
= insn_rtx_cost (PATTERN (insn_a
),
1366 optimize_bb_for_speed_p (BLOCK_FOR_INSN (insn_a
)));
1367 if (insn_cost
== 0 || insn_cost
> COSTS_N_INSNS (if_info
->branch_cost
))
1375 insn_cost
+= insn_rtx_cost (PATTERN (insn_b
),
1376 optimize_bb_for_speed_p (BLOCK_FOR_INSN (insn_b
)));
1377 if (insn_cost
== 0 || insn_cost
> COSTS_N_INSNS (if_info
->branch_cost
))
1381 /* Possibly rearrange operands to make things come out more natural. */
1382 if (reversed_comparison_code (if_info
->cond
, if_info
->jump
) != UNKNOWN
)
1385 if (rtx_equal_p (b
, x
))
1387 else if (general_operand (b
, GET_MODE (b
)))
1392 code
= reversed_comparison_code (if_info
->cond
, if_info
->jump
);
1393 tmp
= a
, a
= b
, b
= tmp
;
1394 tmp
= insn_a
, insn_a
= insn_b
, insn_b
= tmp
;
1403 /* If either operand is complex, load it into a register first.
1404 The best way to do this is to copy the original insn. In this
1405 way we preserve any clobbers etc that the insn may have had.
1406 This is of course not possible in the IS_MEM case. */
1407 if (! general_operand (a
, GET_MODE (a
)))
1413 tmp
= gen_reg_rtx (GET_MODE (a
));
1414 tmp
= emit_insn (gen_rtx_SET (VOIDmode
, tmp
, a
));
1417 goto end_seq_and_fail
;
1420 a
= gen_reg_rtx (GET_MODE (a
));
1421 tmp
= copy_rtx (insn_a
);
1422 set
= single_set (tmp
);
1424 tmp
= emit_insn (PATTERN (tmp
));
1426 if (recog_memoized (tmp
) < 0)
1427 goto end_seq_and_fail
;
1429 if (! general_operand (b
, GET_MODE (b
)))
1435 tmp
= gen_reg_rtx (GET_MODE (b
));
1436 tmp
= gen_rtx_SET (VOIDmode
, tmp
, b
);
1439 goto end_seq_and_fail
;
1442 b
= gen_reg_rtx (GET_MODE (b
));
1443 tmp
= copy_rtx (insn_b
);
1444 set
= single_set (tmp
);
1446 tmp
= PATTERN (tmp
);
1449 /* If insn to set up A clobbers any registers B depends on, try to
1450 swap insn that sets up A with the one that sets up B. If even
1451 that doesn't help, punt. */
1452 last
= get_last_insn ();
1453 if (last
&& modified_in_p (orig_b
, last
))
1455 tmp
= emit_insn_before (tmp
, get_insns ());
1456 if (modified_in_p (orig_a
, tmp
))
1457 goto end_seq_and_fail
;
1460 tmp
= emit_insn (tmp
);
1462 if (recog_memoized (tmp
) < 0)
1463 goto end_seq_and_fail
;
1466 target
= noce_emit_cmove (if_info
, x
, code
, XEXP (if_info
->cond
, 0),
1467 XEXP (if_info
->cond
, 1), a
, b
);
1470 goto end_seq_and_fail
;
1472 /* If we're handling a memory for above, emit the load now. */
1475 tmp
= gen_rtx_MEM (GET_MODE (if_info
->x
), target
);
1477 /* Copy over flags as appropriate. */
1478 if (MEM_VOLATILE_P (if_info
->a
) || MEM_VOLATILE_P (if_info
->b
))
1479 MEM_VOLATILE_P (tmp
) = 1;
1480 if (MEM_IN_STRUCT_P (if_info
->a
) && MEM_IN_STRUCT_P (if_info
->b
))
1481 MEM_IN_STRUCT_P (tmp
) = 1;
1482 if (MEM_SCALAR_P (if_info
->a
) && MEM_SCALAR_P (if_info
->b
))
1483 MEM_SCALAR_P (tmp
) = 1;
1484 if (MEM_ALIAS_SET (if_info
->a
) == MEM_ALIAS_SET (if_info
->b
))
1485 set_mem_alias_set (tmp
, MEM_ALIAS_SET (if_info
->a
));
1487 MIN (MEM_ALIGN (if_info
->a
), MEM_ALIGN (if_info
->b
)));
1489 gcc_assert (MEM_ADDR_SPACE (if_info
->a
) == MEM_ADDR_SPACE (if_info
->b
));
1490 set_mem_addr_space (tmp
, MEM_ADDR_SPACE (if_info
->a
));
1492 noce_emit_move_insn (if_info
->x
, tmp
);
1494 else if (target
!= x
)
1495 noce_emit_move_insn (x
, target
);
1497 tmp
= end_ifcvt_sequence (if_info
);
1501 emit_insn_before_setloc (tmp
, if_info
->jump
, INSN_LOCATOR (if_info
->insn_a
));
1509 /* For most cases, the simplified condition we found is the best
1510 choice, but this is not the case for the min/max/abs transforms.
1511 For these we wish to know that it is A or B in the condition. */
1514 noce_get_alt_condition (struct noce_if_info
*if_info
, rtx target
,
1517 rtx cond
, set
, insn
;
1520 /* If target is already mentioned in the known condition, return it. */
1521 if (reg_mentioned_p (target
, if_info
->cond
))
1523 *earliest
= if_info
->cond_earliest
;
1524 return if_info
->cond
;
1527 set
= pc_set (if_info
->jump
);
1528 cond
= XEXP (SET_SRC (set
), 0);
1530 = GET_CODE (XEXP (SET_SRC (set
), 2)) == LABEL_REF
1531 && XEXP (XEXP (SET_SRC (set
), 2), 0) == JUMP_LABEL (if_info
->jump
);
1532 if (if_info
->then_else_reversed
)
1535 /* If we're looking for a constant, try to make the conditional
1536 have that constant in it. There are two reasons why it may
1537 not have the constant we want:
1539 1. GCC may have needed to put the constant in a register, because
1540 the target can't compare directly against that constant. For
1541 this case, we look for a SET immediately before the comparison
1542 that puts a constant in that register.
1544 2. GCC may have canonicalized the conditional, for example
1545 replacing "if x < 4" with "if x <= 3". We can undo that (or
1546 make equivalent types of changes) to get the constants we need
1547 if they're off by one in the right direction. */
1549 if (CONST_INT_P (target
))
1551 enum rtx_code code
= GET_CODE (if_info
->cond
);
1552 rtx op_a
= XEXP (if_info
->cond
, 0);
1553 rtx op_b
= XEXP (if_info
->cond
, 1);
1556 /* First, look to see if we put a constant in a register. */
1557 prev_insn
= prev_nonnote_insn (if_info
->cond_earliest
);
1559 && BLOCK_NUM (prev_insn
) == BLOCK_NUM (if_info
->cond_earliest
)
1560 && INSN_P (prev_insn
)
1561 && GET_CODE (PATTERN (prev_insn
)) == SET
)
1563 rtx src
= find_reg_equal_equiv_note (prev_insn
);
1565 src
= SET_SRC (PATTERN (prev_insn
));
1566 if (CONST_INT_P (src
))
1568 if (rtx_equal_p (op_a
, SET_DEST (PATTERN (prev_insn
))))
1570 else if (rtx_equal_p (op_b
, SET_DEST (PATTERN (prev_insn
))))
1573 if (CONST_INT_P (op_a
))
1578 code
= swap_condition (code
);
1583 /* Now, look to see if we can get the right constant by
1584 adjusting the conditional. */
1585 if (CONST_INT_P (op_b
))
1587 HOST_WIDE_INT desired_val
= INTVAL (target
);
1588 HOST_WIDE_INT actual_val
= INTVAL (op_b
);
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
);
1614 if (actual_val
== desired_val
+ 1)
1617 op_b
= GEN_INT (desired_val
);
1625 /* If we made any changes, generate a new conditional that is
1626 equivalent to what we started with, but has the right
1628 if (code
!= GET_CODE (if_info
->cond
)
1629 || op_a
!= XEXP (if_info
->cond
, 0)
1630 || op_b
!= XEXP (if_info
->cond
, 1))
1632 cond
= gen_rtx_fmt_ee (code
, GET_MODE (cond
), op_a
, op_b
);
1633 *earliest
= if_info
->cond_earliest
;
1638 cond
= canonicalize_condition (if_info
->jump
, cond
, reverse
,
1639 earliest
, target
, false, true);
1640 if (! cond
|| ! reg_mentioned_p (target
, cond
))
1643 /* We almost certainly searched back to a different place.
1644 Need to re-verify correct lifetimes. */
1646 /* X may not be mentioned in the range (cond_earliest, jump]. */
1647 for (insn
= if_info
->jump
; insn
!= *earliest
; insn
= PREV_INSN (insn
))
1648 if (INSN_P (insn
) && reg_overlap_mentioned_p (if_info
->x
, PATTERN (insn
)))
1651 /* A and B may not be modified in the range [cond_earliest, jump). */
1652 for (insn
= *earliest
; insn
!= if_info
->jump
; insn
= NEXT_INSN (insn
))
1654 && (modified_in_p (if_info
->a
, insn
)
1655 || modified_in_p (if_info
->b
, insn
)))
1661 /* Convert "if (a < b) x = a; else x = b;" to "x = min(a, b);", etc. */
1664 noce_try_minmax (struct noce_if_info
*if_info
)
1666 rtx cond
, earliest
, target
, seq
;
1667 enum rtx_code code
, op
;
1670 /* ??? Reject modes with NaNs or signed zeros since we don't know how
1671 they will be resolved with an SMIN/SMAX. It wouldn't be too hard
1672 to get the target to tell us... */
1673 if (HONOR_SIGNED_ZEROS (GET_MODE (if_info
->x
))
1674 || HONOR_NANS (GET_MODE (if_info
->x
)))
1677 cond
= noce_get_alt_condition (if_info
, if_info
->a
, &earliest
);
1681 /* Verify the condition is of the form we expect, and canonicalize
1682 the comparison code. */
1683 code
= GET_CODE (cond
);
1684 if (rtx_equal_p (XEXP (cond
, 0), if_info
->a
))
1686 if (! rtx_equal_p (XEXP (cond
, 1), if_info
->b
))
1689 else if (rtx_equal_p (XEXP (cond
, 1), if_info
->a
))
1691 if (! rtx_equal_p (XEXP (cond
, 0), if_info
->b
))
1693 code
= swap_condition (code
);
1698 /* Determine what sort of operation this is. Note that the code is for
1699 a taken branch, so the code->operation mapping appears backwards. */
1732 target
= expand_simple_binop (GET_MODE (if_info
->x
), op
,
1733 if_info
->a
, if_info
->b
,
1734 if_info
->x
, unsignedp
, OPTAB_WIDEN
);
1740 if (target
!= if_info
->x
)
1741 noce_emit_move_insn (if_info
->x
, target
);
1743 seq
= end_ifcvt_sequence (if_info
);
1747 emit_insn_before_setloc (seq
, if_info
->jump
, INSN_LOCATOR (if_info
->insn_a
));
1748 if_info
->cond
= cond
;
1749 if_info
->cond_earliest
= earliest
;
1754 /* Convert "if (a < 0) x = -a; else x = a;" to "x = abs(a);",
1755 "if (a < 0) x = ~a; else x = a;" to "x = one_cmpl_abs(a);",
1759 noce_try_abs (struct noce_if_info
*if_info
)
1761 rtx cond
, earliest
, target
, seq
, a
, b
, c
;
1763 bool one_cmpl
= false;
1765 /* Reject modes with signed zeros. */
1766 if (HONOR_SIGNED_ZEROS (GET_MODE (if_info
->x
)))
1769 /* Recognize A and B as constituting an ABS or NABS. The canonical
1770 form is a branch around the negation, taken when the object is the
1771 first operand of a comparison against 0 that evaluates to true. */
1774 if (GET_CODE (a
) == NEG
&& rtx_equal_p (XEXP (a
, 0), b
))
1776 else if (GET_CODE (b
) == NEG
&& rtx_equal_p (XEXP (b
, 0), a
))
1778 c
= a
; a
= b
; b
= c
;
1781 else if (GET_CODE (a
) == NOT
&& rtx_equal_p (XEXP (a
, 0), b
))
1786 else if (GET_CODE (b
) == NOT
&& rtx_equal_p (XEXP (b
, 0), a
))
1788 c
= a
; a
= b
; b
= c
;
1795 cond
= noce_get_alt_condition (if_info
, b
, &earliest
);
1799 /* Verify the condition is of the form we expect. */
1800 if (rtx_equal_p (XEXP (cond
, 0), b
))
1802 else if (rtx_equal_p (XEXP (cond
, 1), b
))
1810 /* Verify that C is zero. Search one step backward for a
1811 REG_EQUAL note or a simple source if necessary. */
1814 rtx set
, insn
= prev_nonnote_insn (earliest
);
1816 && BLOCK_NUM (insn
) == BLOCK_NUM (earliest
)
1817 && (set
= single_set (insn
))
1818 && rtx_equal_p (SET_DEST (set
), c
))
1820 rtx note
= find_reg_equal_equiv_note (insn
);
1830 && GET_CODE (XEXP (c
, 0)) == SYMBOL_REF
1831 && CONSTANT_POOL_ADDRESS_P (XEXP (c
, 0)))
1832 c
= get_pool_constant (XEXP (c
, 0));
1834 /* Work around funny ideas get_condition has wrt canonicalization.
1835 Note that these rtx constants are known to be CONST_INT, and
1836 therefore imply integer comparisons. */
1837 if (c
== constm1_rtx
&& GET_CODE (cond
) == GT
)
1839 else if (c
== const1_rtx
&& GET_CODE (cond
) == LT
)
1841 else if (c
!= CONST0_RTX (GET_MODE (b
)))
1844 /* Determine what sort of operation this is. */
1845 switch (GET_CODE (cond
))
1864 target
= expand_one_cmpl_abs_nojump (GET_MODE (if_info
->x
), b
,
1867 target
= expand_abs_nojump (GET_MODE (if_info
->x
), b
, if_info
->x
, 1);
1869 /* ??? It's a quandary whether cmove would be better here, especially
1870 for integers. Perhaps combine will clean things up. */
1871 if (target
&& negate
)
1874 target
= expand_simple_unop (GET_MODE (target
), NOT
, target
,
1877 target
= expand_simple_unop (GET_MODE (target
), NEG
, target
,
1887 if (target
!= if_info
->x
)
1888 noce_emit_move_insn (if_info
->x
, target
);
1890 seq
= end_ifcvt_sequence (if_info
);
1894 emit_insn_before_setloc (seq
, if_info
->jump
, INSN_LOCATOR (if_info
->insn_a
));
1895 if_info
->cond
= cond
;
1896 if_info
->cond_earliest
= earliest
;
1901 /* Convert "if (m < 0) x = b; else x = 0;" to "x = (m >> C) & b;". */
1904 noce_try_sign_mask (struct noce_if_info
*if_info
)
1906 rtx cond
, t
, m
, c
, seq
;
1907 enum machine_mode mode
;
1909 bool t_unconditional
;
1911 cond
= if_info
->cond
;
1912 code
= GET_CODE (cond
);
1917 if (if_info
->a
== const0_rtx
)
1919 if ((code
== LT
&& c
== const0_rtx
)
1920 || (code
== LE
&& c
== constm1_rtx
))
1923 else if (if_info
->b
== const0_rtx
)
1925 if ((code
== GE
&& c
== const0_rtx
)
1926 || (code
== GT
&& c
== constm1_rtx
))
1930 if (! t
|| side_effects_p (t
))
1933 /* We currently don't handle different modes. */
1934 mode
= GET_MODE (t
);
1935 if (GET_MODE (m
) != mode
)
1938 /* This is only profitable if T is unconditionally executed/evaluated in the
1939 original insn sequence or T is cheap. The former happens if B is the
1940 non-zero (T) value and if INSN_B was taken from TEST_BB, or there was no
1941 INSN_B which can happen for e.g. conditional stores to memory. For the
1942 cost computation use the block TEST_BB where the evaluation will end up
1943 after the transformation. */
1946 && (if_info
->insn_b
== NULL_RTX
1947 || BLOCK_FOR_INSN (if_info
->insn_b
) == if_info
->test_bb
));
1948 if (!(t_unconditional
1949 || (rtx_cost (t
, SET
, optimize_bb_for_speed_p (if_info
->test_bb
))
1950 < COSTS_N_INSNS (2))))
1954 /* Use emit_store_flag to generate "m < 0 ? -1 : 0" instead of expanding
1955 "(signed) m >> 31" directly. This benefits targets with specialized
1956 insns to obtain the signmask, but still uses ashr_optab otherwise. */
1957 m
= emit_store_flag (gen_reg_rtx (mode
), LT
, m
, const0_rtx
, mode
, 0, -1);
1958 t
= m
? expand_binop (mode
, and_optab
, m
, t
, NULL_RTX
, 0, OPTAB_DIRECT
)
1967 noce_emit_move_insn (if_info
->x
, t
);
1969 seq
= end_ifcvt_sequence (if_info
);
1973 emit_insn_before_setloc (seq
, if_info
->jump
, INSN_LOCATOR (if_info
->insn_a
));
1978 /* Optimize away "if (x & C) x |= C" and similar bit manipulation
1982 noce_try_bitop (struct noce_if_info
*if_info
)
1984 rtx cond
, x
, a
, result
, seq
;
1985 enum machine_mode mode
;
1990 cond
= if_info
->cond
;
1991 code
= GET_CODE (cond
);
1993 /* Check for no else condition. */
1994 if (! rtx_equal_p (x
, if_info
->b
))
1997 /* Check for a suitable condition. */
1998 if (code
!= NE
&& code
!= EQ
)
2000 if (XEXP (cond
, 1) != const0_rtx
)
2002 cond
= XEXP (cond
, 0);
2004 /* ??? We could also handle AND here. */
2005 if (GET_CODE (cond
) == ZERO_EXTRACT
)
2007 if (XEXP (cond
, 1) != const1_rtx
2008 || !CONST_INT_P (XEXP (cond
, 2))
2009 || ! rtx_equal_p (x
, XEXP (cond
, 0)))
2011 bitnum
= INTVAL (XEXP (cond
, 2));
2012 mode
= GET_MODE (x
);
2013 if (BITS_BIG_ENDIAN
)
2014 bitnum
= GET_MODE_BITSIZE (mode
) - 1 - bitnum
;
2015 if (bitnum
< 0 || bitnum
>= HOST_BITS_PER_WIDE_INT
)
2022 if (GET_CODE (a
) == IOR
|| GET_CODE (a
) == XOR
)
2024 /* Check for "if (X & C) x = x op C". */
2025 if (! rtx_equal_p (x
, XEXP (a
, 0))
2026 || !CONST_INT_P (XEXP (a
, 1))
2027 || (INTVAL (XEXP (a
, 1)) & GET_MODE_MASK (mode
))
2028 != (unsigned HOST_WIDE_INT
) 1 << bitnum
)
2031 /* if ((x & C) == 0) x |= C; is transformed to x |= C. */
2032 /* if ((x & C) != 0) x |= C; is transformed to nothing. */
2033 if (GET_CODE (a
) == IOR
)
2034 result
= (code
== NE
) ? a
: NULL_RTX
;
2035 else if (code
== NE
)
2037 /* if ((x & C) == 0) x ^= C; is transformed to x |= C. */
2038 result
= gen_int_mode ((HOST_WIDE_INT
) 1 << bitnum
, mode
);
2039 result
= simplify_gen_binary (IOR
, mode
, x
, result
);
2043 /* if ((x & C) != 0) x ^= C; is transformed to x &= ~C. */
2044 result
= gen_int_mode (~((HOST_WIDE_INT
) 1 << bitnum
), mode
);
2045 result
= simplify_gen_binary (AND
, mode
, x
, result
);
2048 else if (GET_CODE (a
) == AND
)
2050 /* Check for "if (X & C) x &= ~C". */
2051 if (! rtx_equal_p (x
, XEXP (a
, 0))
2052 || !CONST_INT_P (XEXP (a
, 1))
2053 || (INTVAL (XEXP (a
, 1)) & GET_MODE_MASK (mode
))
2054 != (~((HOST_WIDE_INT
) 1 << bitnum
) & GET_MODE_MASK (mode
)))
2057 /* if ((x & C) == 0) x &= ~C; is transformed to nothing. */
2058 /* if ((x & C) != 0) x &= ~C; is transformed to x &= ~C. */
2059 result
= (code
== EQ
) ? a
: NULL_RTX
;
2067 noce_emit_move_insn (x
, result
);
2068 seq
= end_ifcvt_sequence (if_info
);
2072 emit_insn_before_setloc (seq
, if_info
->jump
,
2073 INSN_LOCATOR (if_info
->insn_a
));
2079 /* Similar to get_condition, only the resulting condition must be
2080 valid at JUMP, instead of at EARLIEST.
2082 If THEN_ELSE_REVERSED is true, the fallthrough does not go to the
2083 THEN block of the caller, and we have to reverse the condition. */
2086 noce_get_condition (rtx jump
, rtx
*earliest
, bool then_else_reversed
)
2091 if (! any_condjump_p (jump
))
2094 set
= pc_set (jump
);
2096 /* If this branches to JUMP_LABEL when the condition is false,
2097 reverse the condition. */
2098 reverse
= (GET_CODE (XEXP (SET_SRC (set
), 2)) == LABEL_REF
2099 && XEXP (XEXP (SET_SRC (set
), 2), 0) == JUMP_LABEL (jump
));
2101 /* We may have to reverse because the caller's if block is not canonical,
2102 i.e. the THEN block isn't the fallthrough block for the TEST block
2103 (see find_if_header). */
2104 if (then_else_reversed
)
2107 /* If the condition variable is a register and is MODE_INT, accept it. */
2109 cond
= XEXP (SET_SRC (set
), 0);
2110 tmp
= XEXP (cond
, 0);
2111 if (REG_P (tmp
) && GET_MODE_CLASS (GET_MODE (tmp
)) == MODE_INT
)
2116 cond
= gen_rtx_fmt_ee (reverse_condition (GET_CODE (cond
)),
2117 GET_MODE (cond
), tmp
, XEXP (cond
, 1));
2121 /* Otherwise, fall back on canonicalize_condition to do the dirty
2122 work of manipulating MODE_CC values and COMPARE rtx codes. */
2123 return canonicalize_condition (jump
, cond
, reverse
, earliest
,
2124 NULL_RTX
, false, true);
2127 /* Return true if OP is ok for if-then-else processing. */
2130 noce_operand_ok (const_rtx op
)
2132 /* We special-case memories, so handle any of them with
2133 no address side effects. */
2135 return ! side_effects_p (XEXP (op
, 0));
2137 if (side_effects_p (op
))
2140 return ! may_trap_p (op
);
2143 /* Return true if a write into MEM may trap or fault. */
2146 noce_mem_write_may_trap_or_fault_p (const_rtx mem
)
2150 if (MEM_READONLY_P (mem
))
2153 if (may_trap_or_fault_p (mem
))
2156 addr
= XEXP (mem
, 0);
2158 /* Call target hook to avoid the effects of -fpic etc.... */
2159 addr
= targetm
.delegitimize_address (addr
);
2162 switch (GET_CODE (addr
))
2170 addr
= XEXP (addr
, 0);
2174 addr
= XEXP (addr
, 1);
2177 if (CONST_INT_P (XEXP (addr
, 1)))
2178 addr
= XEXP (addr
, 0);
2185 if (SYMBOL_REF_DECL (addr
)
2186 && decl_readonly_section (SYMBOL_REF_DECL (addr
), 0))
2196 /* Return whether we can use store speculation for MEM. TOP_BB is the
2197 basic block above the conditional block where we are considering
2198 doing the speculative store. We look for whether MEM is set
2199 unconditionally later in the function. */
2202 noce_can_store_speculate_p (basic_block top_bb
, const_rtx mem
)
2204 basic_block dominator
;
2206 for (dominator
= get_immediate_dominator (CDI_POST_DOMINATORS
, top_bb
);
2208 dominator
= get_immediate_dominator (CDI_POST_DOMINATORS
, dominator
))
2212 FOR_BB_INSNS (dominator
, insn
)
2214 /* If we see something that might be a memory barrier, we
2215 have to stop looking. Even if the MEM is set later in
2216 the function, we still don't want to set it
2217 unconditionally before the barrier. */
2219 && (volatile_insn_p (PATTERN (insn
))
2220 || (CALL_P (insn
) && (!RTL_CONST_CALL_P (insn
)))))
2223 if (memory_modified_in_insn_p (mem
, insn
))
2225 if (modified_in_p (XEXP (mem
, 0), insn
))
2234 /* Given a simple IF-THEN-JOIN or IF-THEN-ELSE-JOIN block, attempt to convert
2235 it without using conditional execution. Return TRUE if we were successful
2236 at converting the block. */
2239 noce_process_if_block (struct noce_if_info
*if_info
)
2241 basic_block test_bb
= if_info
->test_bb
; /* test block */
2242 basic_block then_bb
= if_info
->then_bb
; /* THEN */
2243 basic_block else_bb
= if_info
->else_bb
; /* ELSE or NULL */
2244 basic_block join_bb
= if_info
->join_bb
; /* JOIN */
2245 rtx jump
= if_info
->jump
;
2246 rtx cond
= if_info
->cond
;
2249 rtx orig_x
, x
, a
, b
;
2251 /* We're looking for patterns of the form
2253 (1) if (...) x = a; else x = b;
2254 (2) x = b; if (...) x = a;
2255 (3) if (...) x = a; // as if with an initial x = x.
2257 The later patterns require jumps to be more expensive.
2259 ??? For future expansion, look for multiple X in such patterns. */
2261 /* Look for one of the potential sets. */
2262 insn_a
= first_active_insn (then_bb
);
2264 || insn_a
!= last_active_insn (then_bb
, FALSE
)
2265 || (set_a
= single_set (insn_a
)) == NULL_RTX
)
2268 x
= SET_DEST (set_a
);
2269 a
= SET_SRC (set_a
);
2271 /* Look for the other potential set. Make sure we've got equivalent
2273 /* ??? This is overconservative. Storing to two different mems is
2274 as easy as conditionally computing the address. Storing to a
2275 single mem merely requires a scratch memory to use as one of the
2276 destination addresses; often the memory immediately below the
2277 stack pointer is available for this. */
2281 insn_b
= first_active_insn (else_bb
);
2283 || insn_b
!= last_active_insn (else_bb
, FALSE
)
2284 || (set_b
= single_set (insn_b
)) == NULL_RTX
2285 || ! rtx_equal_p (x
, SET_DEST (set_b
)))
2290 insn_b
= prev_nonnote_insn (if_info
->cond_earliest
);
2291 while (insn_b
&& DEBUG_INSN_P (insn_b
))
2292 insn_b
= prev_nonnote_insn (insn_b
);
2293 /* We're going to be moving the evaluation of B down from above
2294 COND_EARLIEST to JUMP. Make sure the relevant data is still
2297 || BLOCK_NUM (insn_b
) != BLOCK_NUM (if_info
->cond_earliest
)
2298 || !NONJUMP_INSN_P (insn_b
)
2299 || (set_b
= single_set (insn_b
)) == NULL_RTX
2300 || ! rtx_equal_p (x
, SET_DEST (set_b
))
2301 || ! noce_operand_ok (SET_SRC (set_b
))
2302 || reg_overlap_mentioned_p (x
, SET_SRC (set_b
))
2303 || modified_between_p (SET_SRC (set_b
), insn_b
, jump
)
2304 /* Likewise with X. In particular this can happen when
2305 noce_get_condition looks farther back in the instruction
2306 stream than one might expect. */
2307 || reg_overlap_mentioned_p (x
, cond
)
2308 || reg_overlap_mentioned_p (x
, a
)
2309 || modified_between_p (x
, insn_b
, jump
))
2310 insn_b
= set_b
= NULL_RTX
;
2313 /* If x has side effects then only the if-then-else form is safe to
2314 convert. But even in that case we would need to restore any notes
2315 (such as REG_INC) at then end. That can be tricky if
2316 noce_emit_move_insn expands to more than one insn, so disable the
2317 optimization entirely for now if there are side effects. */
2318 if (side_effects_p (x
))
2321 b
= (set_b
? SET_SRC (set_b
) : x
);
2323 /* Only operate on register destinations, and even then avoid extending
2324 the lifetime of hard registers on small register class machines. */
2327 || (SMALL_REGISTER_CLASSES
2328 && REGNO (x
) < FIRST_PSEUDO_REGISTER
))
2330 if (GET_MODE (x
) == BLKmode
)
2333 if (GET_CODE (x
) == ZERO_EXTRACT
2334 && (!CONST_INT_P (XEXP (x
, 1))
2335 || !CONST_INT_P (XEXP (x
, 2))))
2338 x
= gen_reg_rtx (GET_MODE (GET_CODE (x
) == STRICT_LOW_PART
2339 ? XEXP (x
, 0) : x
));
2342 /* Don't operate on sources that may trap or are volatile. */
2343 if (! noce_operand_ok (a
) || ! noce_operand_ok (b
))
2347 /* Set up the info block for our subroutines. */
2348 if_info
->insn_a
= insn_a
;
2349 if_info
->insn_b
= insn_b
;
2354 /* Try optimizations in some approximation of a useful order. */
2355 /* ??? Should first look to see if X is live incoming at all. If it
2356 isn't, we don't need anything but an unconditional set. */
2358 /* Look and see if A and B are really the same. Avoid creating silly
2359 cmove constructs that no one will fix up later. */
2360 if (rtx_equal_p (a
, b
))
2362 /* If we have an INSN_B, we don't have to create any new rtl. Just
2363 move the instruction that we already have. If we don't have an
2364 INSN_B, that means that A == X, and we've got a noop move. In
2365 that case don't do anything and let the code below delete INSN_A. */
2366 if (insn_b
&& else_bb
)
2370 if (else_bb
&& insn_b
== BB_END (else_bb
))
2371 BB_END (else_bb
) = PREV_INSN (insn_b
);
2372 reorder_insns (insn_b
, insn_b
, PREV_INSN (jump
));
2374 /* If there was a REG_EQUAL note, delete it since it may have been
2375 true due to this insn being after a jump. */
2376 if ((note
= find_reg_note (insn_b
, REG_EQUAL
, NULL_RTX
)) != 0)
2377 remove_note (insn_b
, note
);
2381 /* If we have "x = b; if (...) x = a;", and x has side-effects, then
2382 x must be executed twice. */
2383 else if (insn_b
&& side_effects_p (orig_x
))
2390 if (!set_b
&& MEM_P (orig_x
))
2392 /* Disallow the "if (...) x = a;" form (implicit "else x = x;")
2393 for optimizations if writing to x may trap or fault,
2394 i.e. it's a memory other than a static var or a stack slot,
2395 is misaligned on strict aligned machines or is read-only. If
2396 x is a read-only memory, then the program is valid only if we
2397 avoid the store into it. If there are stores on both the
2398 THEN and ELSE arms, then we can go ahead with the conversion;
2399 either the program is broken, or the condition is always
2400 false such that the other memory is selected. */
2401 if (noce_mem_write_may_trap_or_fault_p (orig_x
))
2404 /* Avoid store speculation: given "if (...) x = a" where x is a
2405 MEM, we only want to do the store if x is always set
2406 somewhere in the function. This avoids cases like
2407 if (pthread_mutex_trylock(mutex))
2409 where we only want global_variable to be changed if the mutex
2410 is held. FIXME: This should ideally be expressed directly in
2412 if (!noce_can_store_speculate_p (test_bb
, orig_x
))
2416 if (noce_try_move (if_info
))
2418 if (noce_try_store_flag (if_info
))
2420 if (noce_try_bitop (if_info
))
2422 if (noce_try_minmax (if_info
))
2424 if (noce_try_abs (if_info
))
2426 if (HAVE_conditional_move
2427 && noce_try_cmove (if_info
))
2429 if (! HAVE_conditional_execution
)
2431 if (noce_try_store_flag_constants (if_info
))
2433 if (noce_try_addcc (if_info
))
2435 if (noce_try_store_flag_mask (if_info
))
2437 if (HAVE_conditional_move
2438 && noce_try_cmove_arith (if_info
))
2440 if (noce_try_sign_mask (if_info
))
2444 if (!else_bb
&& set_b
)
2446 insn_b
= set_b
= NULL_RTX
;
2455 /* If we used a temporary, fix it up now. */
2461 noce_emit_move_insn (orig_x
, x
);
2463 set_used_flags (orig_x
);
2464 unshare_all_rtl_in_chain (seq
);
2467 emit_insn_before_setloc (seq
, BB_END (test_bb
), INSN_LOCATOR (insn_a
));
2470 /* The original THEN and ELSE blocks may now be removed. The test block
2471 must now jump to the join block. If the test block and the join block
2472 can be merged, do so. */
2475 delete_basic_block (else_bb
);
2479 remove_edge (find_edge (test_bb
, join_bb
));
2481 remove_edge (find_edge (then_bb
, join_bb
));
2482 redirect_edge_and_branch_force (single_succ_edge (test_bb
), join_bb
);
2483 delete_basic_block (then_bb
);
2486 if (can_merge_blocks_p (test_bb
, join_bb
))
2488 merge_blocks (test_bb
, join_bb
);
2492 num_updated_if_blocks
++;
2496 /* Check whether a block is suitable for conditional move conversion.
2497 Every insn must be a simple set of a register to a constant or a
2498 register. For each assignment, store the value in the array VALS,
2499 indexed by register number, then store the register number in
2500 REGS. COND is the condition we will test. */
2503 check_cond_move_block (basic_block bb
, rtx
*vals
, VEC (int, heap
) **regs
, rtx cond
)
2507 /* We can only handle simple jumps at the end of the basic block.
2508 It is almost impossible to update the CFG otherwise. */
2510 if (JUMP_P (insn
) && !onlyjump_p (insn
))
2513 FOR_BB_INSNS (bb
, insn
)
2517 if (!NONDEBUG_INSN_P (insn
) || JUMP_P (insn
))
2519 set
= single_set (insn
);
2523 dest
= SET_DEST (set
);
2524 src
= SET_SRC (set
);
2526 || (SMALL_REGISTER_CLASSES
&& HARD_REGISTER_P (dest
)))
2529 if (!CONSTANT_P (src
) && !register_operand (src
, VOIDmode
))
2532 if (side_effects_p (src
) || side_effects_p (dest
))
2535 if (may_trap_p (src
) || may_trap_p (dest
))
2538 /* Don't try to handle this if the source register was
2539 modified earlier in the block. */
2541 && vals
[REGNO (src
)] != NULL
)
2542 || (GET_CODE (src
) == SUBREG
&& REG_P (SUBREG_REG (src
))
2543 && vals
[REGNO (SUBREG_REG (src
))] != NULL
))
2546 /* Don't try to handle this if the destination register was
2547 modified earlier in the block. */
2548 if (vals
[REGNO (dest
)] != NULL
)
2551 /* Don't try to handle this if the condition uses the
2552 destination register. */
2553 if (reg_overlap_mentioned_p (dest
, cond
))
2556 /* Don't try to handle this if the source register is modified
2557 later in the block. */
2558 if (!CONSTANT_P (src
)
2559 && modified_between_p (src
, insn
, NEXT_INSN (BB_END (bb
))))
2562 vals
[REGNO (dest
)] = src
;
2564 VEC_safe_push (int, heap
, *regs
, REGNO (dest
));
2570 /* Given a basic block BB suitable for conditional move conversion,
2571 a condition COND, and arrays THEN_VALS and ELSE_VALS containing the
2572 register values depending on COND, emit the insns in the block as
2573 conditional moves. If ELSE_BLOCK is true, THEN_BB was already
2574 processed. The caller has started a sequence for the conversion.
2575 Return true if successful, false if something goes wrong. */
2578 cond_move_convert_if_block (struct noce_if_info
*if_infop
,
2579 basic_block bb
, rtx cond
,
2580 rtx
*then_vals
, rtx
*else_vals
,
2584 rtx insn
, cond_arg0
, cond_arg1
;
2586 code
= GET_CODE (cond
);
2587 cond_arg0
= XEXP (cond
, 0);
2588 cond_arg1
= XEXP (cond
, 1);
2590 FOR_BB_INSNS (bb
, insn
)
2592 rtx set
, target
, dest
, t
, e
;
2595 /* ??? Maybe emit conditional debug insn? */
2596 if (!NONDEBUG_INSN_P (insn
) || JUMP_P (insn
))
2598 set
= single_set (insn
);
2599 gcc_assert (set
&& REG_P (SET_DEST (set
)));
2601 dest
= SET_DEST (set
);
2602 regno
= REGNO (dest
);
2604 t
= then_vals
[regno
];
2605 e
= else_vals
[regno
];
2609 /* If this register was set in the then block, we already
2610 handled this case there. */
2623 target
= noce_emit_cmove (if_infop
, dest
, code
, cond_arg0
, cond_arg1
,
2629 noce_emit_move_insn (dest
, target
);
2635 /* Given a simple IF-THEN-JOIN or IF-THEN-ELSE-JOIN block, attempt to convert
2636 it using only conditional moves. Return TRUE if we were successful at
2637 converting the block. */
2640 cond_move_process_if_block (struct noce_if_info
*if_info
)
2642 basic_block test_bb
= if_info
->test_bb
;
2643 basic_block then_bb
= if_info
->then_bb
;
2644 basic_block else_bb
= if_info
->else_bb
;
2645 basic_block join_bb
= if_info
->join_bb
;
2646 rtx jump
= if_info
->jump
;
2647 rtx cond
= if_info
->cond
;
2649 int max_reg
, size
, c
, reg
;
2652 VEC (int, heap
) *then_regs
= NULL
;
2653 VEC (int, heap
) *else_regs
= NULL
;
2656 /* Build a mapping for each block to the value used for each
2658 max_reg
= max_reg_num ();
2659 size
= (max_reg
+ 1) * sizeof (rtx
);
2660 then_vals
= (rtx
*) alloca (size
);
2661 else_vals
= (rtx
*) alloca (size
);
2662 memset (then_vals
, 0, size
);
2663 memset (else_vals
, 0, size
);
2665 /* Make sure the blocks are suitable. */
2666 if (!check_cond_move_block (then_bb
, then_vals
, &then_regs
, cond
)
2667 || (else_bb
&& !check_cond_move_block (else_bb
, else_vals
, &else_regs
, cond
)))
2669 VEC_free (int, heap
, then_regs
);
2670 VEC_free (int, heap
, else_regs
);
2674 /* Make sure the blocks can be used together. If the same register
2675 is set in both blocks, and is not set to a constant in both
2676 cases, then both blocks must set it to the same register. We
2677 have already verified that if it is set to a register, that the
2678 source register does not change after the assignment. Also count
2679 the number of registers set in only one of the blocks. */
2681 for (i
= 0; VEC_iterate (int, then_regs
, i
, reg
); i
++)
2683 if (!then_vals
[reg
] && !else_vals
[reg
])
2686 if (!else_vals
[reg
])
2690 if (!CONSTANT_P (then_vals
[reg
])
2691 && !CONSTANT_P (else_vals
[reg
])
2692 && !rtx_equal_p (then_vals
[reg
], else_vals
[reg
]))
2694 VEC_free (int, heap
, then_regs
);
2695 VEC_free (int, heap
, else_regs
);
2701 /* Finish off c for MAX_CONDITIONAL_EXECUTE. */
2702 for (i
= 0; VEC_iterate (int, else_regs
, i
, reg
); ++i
)
2703 if (!then_vals
[reg
])
2706 /* Make sure it is reasonable to convert this block. What matters
2707 is the number of assignments currently made in only one of the
2708 branches, since if we convert we are going to always execute
2710 if (c
> MAX_CONDITIONAL_EXECUTE
)
2712 VEC_free (int, heap
, then_regs
);
2713 VEC_free (int, heap
, else_regs
);
2717 /* Try to emit the conditional moves. First do the then block,
2718 then do anything left in the else blocks. */
2720 if (!cond_move_convert_if_block (if_info
, then_bb
, cond
,
2721 then_vals
, else_vals
, false)
2723 && !cond_move_convert_if_block (if_info
, else_bb
, cond
,
2724 then_vals
, else_vals
, true)))
2727 VEC_free (int, heap
, then_regs
);
2728 VEC_free (int, heap
, else_regs
);
2731 seq
= end_ifcvt_sequence (if_info
);
2734 VEC_free (int, heap
, then_regs
);
2735 VEC_free (int, heap
, else_regs
);
2739 loc_insn
= first_active_insn (then_bb
);
2742 loc_insn
= first_active_insn (else_bb
);
2743 gcc_assert (loc_insn
);
2745 emit_insn_before_setloc (seq
, jump
, INSN_LOCATOR (loc_insn
));
2749 delete_basic_block (else_bb
);
2753 remove_edge (find_edge (test_bb
, join_bb
));
2755 remove_edge (find_edge (then_bb
, join_bb
));
2756 redirect_edge_and_branch_force (single_succ_edge (test_bb
), join_bb
);
2757 delete_basic_block (then_bb
);
2760 if (can_merge_blocks_p (test_bb
, join_bb
))
2762 merge_blocks (test_bb
, join_bb
);
2766 num_updated_if_blocks
++;
2768 VEC_free (int, heap
, then_regs
);
2769 VEC_free (int, heap
, else_regs
);
2774 /* Determine if a given basic block heads a simple IF-THEN-JOIN or an
2775 IF-THEN-ELSE-JOIN block.
2777 If so, we'll try to convert the insns to not require the branch,
2778 using only transformations that do not require conditional execution.
2780 Return TRUE if we were successful at converting the block. */
2783 noce_find_if_block (basic_block test_bb
,
2784 edge then_edge
, edge else_edge
,
2787 basic_block then_bb
, else_bb
, join_bb
;
2788 bool then_else_reversed
= false;
2791 struct noce_if_info if_info
;
2793 /* We only ever should get here before reload. */
2794 gcc_assert (!reload_completed
);
2796 /* Recognize an IF-THEN-ELSE-JOIN block. */
2797 if (single_pred_p (then_edge
->dest
)
2798 && single_succ_p (then_edge
->dest
)
2799 && single_pred_p (else_edge
->dest
)
2800 && single_succ_p (else_edge
->dest
)
2801 && single_succ (then_edge
->dest
) == single_succ (else_edge
->dest
))
2803 then_bb
= then_edge
->dest
;
2804 else_bb
= else_edge
->dest
;
2805 join_bb
= single_succ (then_bb
);
2807 /* Recognize an IF-THEN-JOIN block. */
2808 else if (single_pred_p (then_edge
->dest
)
2809 && single_succ_p (then_edge
->dest
)
2810 && single_succ (then_edge
->dest
) == else_edge
->dest
)
2812 then_bb
= then_edge
->dest
;
2813 else_bb
= NULL_BLOCK
;
2814 join_bb
= else_edge
->dest
;
2816 /* Recognize an IF-ELSE-JOIN block. We can have those because the order
2817 of basic blocks in cfglayout mode does not matter, so the fallthrough
2818 edge can go to any basic block (and not just to bb->next_bb, like in
2820 else if (single_pred_p (else_edge
->dest
)
2821 && single_succ_p (else_edge
->dest
)
2822 && single_succ (else_edge
->dest
) == then_edge
->dest
)
2824 /* The noce transformations do not apply to IF-ELSE-JOIN blocks.
2825 To make this work, we have to invert the THEN and ELSE blocks
2826 and reverse the jump condition. */
2827 then_bb
= else_edge
->dest
;
2828 else_bb
= NULL_BLOCK
;
2829 join_bb
= single_succ (then_bb
);
2830 then_else_reversed
= true;
2833 /* Not a form we can handle. */
2836 /* The edges of the THEN and ELSE blocks cannot have complex edges. */
2837 if (single_succ_edge (then_bb
)->flags
& EDGE_COMPLEX
)
2840 && single_succ_edge (else_bb
)->flags
& EDGE_COMPLEX
)
2843 num_possible_if_blocks
++;
2848 "\nIF-THEN%s-JOIN block found, pass %d, test %d, then %d",
2849 (else_bb
) ? "-ELSE" : "",
2850 pass
, test_bb
->index
, then_bb
->index
);
2853 fprintf (dump_file
, ", else %d", else_bb
->index
);
2855 fprintf (dump_file
, ", join %d\n", join_bb
->index
);
2858 /* If the conditional jump is more than just a conditional
2859 jump, then we can not do if-conversion on this block. */
2860 jump
= BB_END (test_bb
);
2861 if (! onlyjump_p (jump
))
2864 /* If this is not a standard conditional jump, we can't parse it. */
2865 cond
= noce_get_condition (jump
,
2867 then_else_reversed
);
2871 /* We must be comparing objects whose modes imply the size. */
2872 if (GET_MODE (XEXP (cond
, 0)) == BLKmode
)
2875 /* Initialize an IF_INFO struct to pass around. */
2876 memset (&if_info
, 0, sizeof if_info
);
2877 if_info
.test_bb
= test_bb
;
2878 if_info
.then_bb
= then_bb
;
2879 if_info
.else_bb
= else_bb
;
2880 if_info
.join_bb
= join_bb
;
2881 if_info
.cond
= cond
;
2882 if_info
.cond_earliest
= cond_earliest
;
2883 if_info
.jump
= jump
;
2884 if_info
.then_else_reversed
= then_else_reversed
;
2885 if_info
.branch_cost
= BRANCH_COST (optimize_bb_for_speed_p (test_bb
),
2886 predictable_edge_p (then_edge
));
2888 /* Do the real work. */
2890 if (noce_process_if_block (&if_info
))
2893 if (HAVE_conditional_move
2894 && cond_move_process_if_block (&if_info
))
2901 /* Merge the blocks and mark for local life update. */
2904 merge_if_block (struct ce_if_block
* ce_info
)
2906 basic_block test_bb
= ce_info
->test_bb
; /* last test block */
2907 basic_block then_bb
= ce_info
->then_bb
; /* THEN */
2908 basic_block else_bb
= ce_info
->else_bb
; /* ELSE or NULL */
2909 basic_block join_bb
= ce_info
->join_bb
; /* join block */
2910 basic_block combo_bb
;
2912 /* All block merging is done into the lower block numbers. */
2915 df_set_bb_dirty (test_bb
);
2917 /* Merge any basic blocks to handle && and || subtests. Each of
2918 the blocks are on the fallthru path from the predecessor block. */
2919 if (ce_info
->num_multiple_test_blocks
> 0)
2921 basic_block bb
= test_bb
;
2922 basic_block last_test_bb
= ce_info
->last_test_bb
;
2923 basic_block fallthru
= block_fallthru (bb
);
2928 fallthru
= block_fallthru (bb
);
2929 merge_blocks (combo_bb
, bb
);
2932 while (bb
!= last_test_bb
);
2935 /* Merge TEST block into THEN block. Normally the THEN block won't have a
2936 label, but it might if there were || tests. That label's count should be
2937 zero, and it normally should be removed. */
2941 merge_blocks (combo_bb
, then_bb
);
2945 /* The ELSE block, if it existed, had a label. That label count
2946 will almost always be zero, but odd things can happen when labels
2947 get their addresses taken. */
2950 merge_blocks (combo_bb
, else_bb
);
2954 /* If there was no join block reported, that means it was not adjacent
2955 to the others, and so we cannot merge them. */
2959 rtx last
= BB_END (combo_bb
);
2961 /* The outgoing edge for the current COMBO block should already
2962 be correct. Verify this. */
2963 if (EDGE_COUNT (combo_bb
->succs
) == 0)
2964 gcc_assert (find_reg_note (last
, REG_NORETURN
, NULL
)
2965 || (NONJUMP_INSN_P (last
)
2966 && GET_CODE (PATTERN (last
)) == TRAP_IF
2967 && (TRAP_CONDITION (PATTERN (last
))
2968 == const_true_rtx
)));
2971 /* There should still be something at the end of the THEN or ELSE
2972 blocks taking us to our final destination. */
2973 gcc_assert (JUMP_P (last
)
2974 || (EDGE_SUCC (combo_bb
, 0)->dest
== EXIT_BLOCK_PTR
2976 && SIBLING_CALL_P (last
))
2977 || ((EDGE_SUCC (combo_bb
, 0)->flags
& EDGE_EH
)
2978 && can_throw_internal (last
)));
2981 /* The JOIN block may have had quite a number of other predecessors too.
2982 Since we've already merged the TEST, THEN and ELSE blocks, we should
2983 have only one remaining edge from our if-then-else diamond. If there
2984 is more than one remaining edge, it must come from elsewhere. There
2985 may be zero incoming edges if the THEN block didn't actually join
2986 back up (as with a call to a non-return function). */
2987 else if (EDGE_COUNT (join_bb
->preds
) < 2
2988 && join_bb
!= EXIT_BLOCK_PTR
)
2990 /* We can merge the JOIN cleanly and update the dataflow try
2991 again on this pass.*/
2992 merge_blocks (combo_bb
, join_bb
);
2997 /* We cannot merge the JOIN. */
2999 /* The outgoing edge for the current COMBO block should already
3000 be correct. Verify this. */
3001 gcc_assert (single_succ_p (combo_bb
)
3002 && single_succ (combo_bb
) == join_bb
);
3004 /* Remove the jump and cruft from the end of the COMBO block. */
3005 if (join_bb
!= EXIT_BLOCK_PTR
)
3006 tidy_fallthru_edge (single_succ_edge (combo_bb
));
3009 num_updated_if_blocks
++;
3012 /* Find a block ending in a simple IF condition and try to transform it
3013 in some way. When converting a multi-block condition, put the new code
3014 in the first such block and delete the rest. Return a pointer to this
3015 first block if some transformation was done. Return NULL otherwise. */
3018 find_if_header (basic_block test_bb
, int pass
)
3020 ce_if_block_t ce_info
;
3024 /* The kind of block we're looking for has exactly two successors. */
3025 if (EDGE_COUNT (test_bb
->succs
) != 2)
3028 then_edge
= EDGE_SUCC (test_bb
, 0);
3029 else_edge
= EDGE_SUCC (test_bb
, 1);
3031 if (df_get_bb_dirty (then_edge
->dest
))
3033 if (df_get_bb_dirty (else_edge
->dest
))
3036 /* Neither edge should be abnormal. */
3037 if ((then_edge
->flags
& EDGE_COMPLEX
)
3038 || (else_edge
->flags
& EDGE_COMPLEX
))
3041 /* Nor exit the loop. */
3042 if ((then_edge
->flags
& EDGE_LOOP_EXIT
)
3043 || (else_edge
->flags
& EDGE_LOOP_EXIT
))
3046 /* The THEN edge is canonically the one that falls through. */
3047 if (then_edge
->flags
& EDGE_FALLTHRU
)
3049 else if (else_edge
->flags
& EDGE_FALLTHRU
)
3052 else_edge
= then_edge
;
3056 /* Otherwise this must be a multiway branch of some sort. */
3059 memset (&ce_info
, '\0', sizeof (ce_info
));
3060 ce_info
.test_bb
= test_bb
;
3061 ce_info
.then_bb
= then_edge
->dest
;
3062 ce_info
.else_bb
= else_edge
->dest
;
3063 ce_info
.pass
= pass
;
3065 #ifdef IFCVT_INIT_EXTRA_FIELDS
3066 IFCVT_INIT_EXTRA_FIELDS (&ce_info
);
3069 if (! reload_completed
3070 && noce_find_if_block (test_bb
, then_edge
, else_edge
, pass
))
3073 if (HAVE_conditional_execution
&& reload_completed
3074 && cond_exec_find_if_block (&ce_info
))
3078 && optab_handler (ctrap_optab
, word_mode
)->insn_code
!= CODE_FOR_nothing
3079 && find_cond_trap (test_bb
, then_edge
, else_edge
))
3082 if (dom_info_state (CDI_POST_DOMINATORS
) >= DOM_NO_FAST_QUERY
3083 && (! HAVE_conditional_execution
|| reload_completed
))
3085 if (find_if_case_1 (test_bb
, then_edge
, else_edge
))
3087 if (find_if_case_2 (test_bb
, then_edge
, else_edge
))
3095 fprintf (dump_file
, "Conversion succeeded on pass %d.\n", pass
);
3096 /* Set this so we continue looking. */
3097 cond_exec_changed_p
= TRUE
;
3098 return ce_info
.test_bb
;
3101 /* Return true if a block has two edges, one of which falls through to the next
3102 block, and the other jumps to a specific block, so that we can tell if the
3103 block is part of an && test or an || test. Returns either -1 or the number
3104 of non-note, non-jump, non-USE/CLOBBER insns in the block. */
3107 block_jumps_and_fallthru_p (basic_block cur_bb
, basic_block target_bb
)
3110 int fallthru_p
= FALSE
;
3117 if (!cur_bb
|| !target_bb
)
3120 /* If no edges, obviously it doesn't jump or fallthru. */
3121 if (EDGE_COUNT (cur_bb
->succs
) == 0)
3124 FOR_EACH_EDGE (cur_edge
, ei
, cur_bb
->succs
)
3126 if (cur_edge
->flags
& EDGE_COMPLEX
)
3127 /* Anything complex isn't what we want. */
3130 else if (cur_edge
->flags
& EDGE_FALLTHRU
)
3133 else if (cur_edge
->dest
== target_bb
)
3140 if ((jump_p
& fallthru_p
) == 0)
3143 /* Don't allow calls in the block, since this is used to group && and ||
3144 together for conditional execution support. ??? we should support
3145 conditional execution support across calls for IA-64 some day, but
3146 for now it makes the code simpler. */
3147 end
= BB_END (cur_bb
);
3148 insn
= BB_HEAD (cur_bb
);
3150 while (insn
!= NULL_RTX
)
3157 && !DEBUG_INSN_P (insn
)
3158 && GET_CODE (PATTERN (insn
)) != USE
3159 && GET_CODE (PATTERN (insn
)) != CLOBBER
)
3165 insn
= NEXT_INSN (insn
);
3171 /* Determine if a given basic block heads a simple IF-THEN or IF-THEN-ELSE
3172 block. If so, we'll try to convert the insns to not require the branch.
3173 Return TRUE if we were successful at converting the block. */
3176 cond_exec_find_if_block (struct ce_if_block
* ce_info
)
3178 basic_block test_bb
= ce_info
->test_bb
;
3179 basic_block then_bb
= ce_info
->then_bb
;
3180 basic_block else_bb
= ce_info
->else_bb
;
3181 basic_block join_bb
= NULL_BLOCK
;
3186 ce_info
->last_test_bb
= test_bb
;
3188 /* We only ever should get here after reload,
3189 and only if we have conditional execution. */
3190 gcc_assert (HAVE_conditional_execution
&& reload_completed
);
3192 /* Discover if any fall through predecessors of the current test basic block
3193 were && tests (which jump to the else block) or || tests (which jump to
3195 if (single_pred_p (test_bb
)
3196 && single_pred_edge (test_bb
)->flags
== EDGE_FALLTHRU
)
3198 basic_block bb
= single_pred (test_bb
);
3199 basic_block target_bb
;
3200 int max_insns
= MAX_CONDITIONAL_EXECUTE
;
3203 /* Determine if the preceding block is an && or || block. */
3204 if ((n_insns
= block_jumps_and_fallthru_p (bb
, else_bb
)) >= 0)
3206 ce_info
->and_and_p
= TRUE
;
3207 target_bb
= else_bb
;
3209 else if ((n_insns
= block_jumps_and_fallthru_p (bb
, then_bb
)) >= 0)
3211 ce_info
->and_and_p
= FALSE
;
3212 target_bb
= then_bb
;
3215 target_bb
= NULL_BLOCK
;
3217 if (target_bb
&& n_insns
<= max_insns
)
3219 int total_insns
= 0;
3222 ce_info
->last_test_bb
= test_bb
;
3224 /* Found at least one && or || block, look for more. */
3227 ce_info
->test_bb
= test_bb
= bb
;
3228 total_insns
+= n_insns
;
3231 if (!single_pred_p (bb
))
3234 bb
= single_pred (bb
);
3235 n_insns
= block_jumps_and_fallthru_p (bb
, target_bb
);
3237 while (n_insns
>= 0 && (total_insns
+ n_insns
) <= max_insns
);
3239 ce_info
->num_multiple_test_blocks
= blocks
;
3240 ce_info
->num_multiple_test_insns
= total_insns
;
3242 if (ce_info
->and_and_p
)
3243 ce_info
->num_and_and_blocks
= blocks
;
3245 ce_info
->num_or_or_blocks
= blocks
;
3249 /* The THEN block of an IF-THEN combo must have exactly one predecessor,
3250 other than any || blocks which jump to the THEN block. */
3251 if ((EDGE_COUNT (then_bb
->preds
) - ce_info
->num_or_or_blocks
) != 1)
3254 /* The edges of the THEN and ELSE blocks cannot have complex edges. */
3255 FOR_EACH_EDGE (cur_edge
, ei
, then_bb
->preds
)
3257 if (cur_edge
->flags
& EDGE_COMPLEX
)
3261 FOR_EACH_EDGE (cur_edge
, ei
, else_bb
->preds
)
3263 if (cur_edge
->flags
& EDGE_COMPLEX
)
3267 /* The THEN block of an IF-THEN combo must have zero or one successors. */
3268 if (EDGE_COUNT (then_bb
->succs
) > 0
3269 && (!single_succ_p (then_bb
)
3270 || (single_succ_edge (then_bb
)->flags
& EDGE_COMPLEX
)
3271 || (epilogue_completed
&& tablejump_p (BB_END (then_bb
), NULL
, NULL
))))
3274 /* If the THEN block has no successors, conditional execution can still
3275 make a conditional call. Don't do this unless the ELSE block has
3276 only one incoming edge -- the CFG manipulation is too ugly otherwise.
3277 Check for the last insn of the THEN block being an indirect jump, which
3278 is listed as not having any successors, but confuses the rest of the CE
3279 code processing. ??? we should fix this in the future. */
3280 if (EDGE_COUNT (then_bb
->succs
) == 0)
3282 if (single_pred_p (else_bb
))
3284 rtx last_insn
= BB_END (then_bb
);
3287 && NOTE_P (last_insn
)
3288 && last_insn
!= BB_HEAD (then_bb
))
3289 last_insn
= PREV_INSN (last_insn
);
3292 && JUMP_P (last_insn
)
3293 && ! simplejump_p (last_insn
))
3297 else_bb
= NULL_BLOCK
;
3303 /* If the THEN block's successor is the other edge out of the TEST block,
3304 then we have an IF-THEN combo without an ELSE. */
3305 else if (single_succ (then_bb
) == else_bb
)
3308 else_bb
= NULL_BLOCK
;
3311 /* If the THEN and ELSE block meet in a subsequent block, and the ELSE
3312 has exactly one predecessor and one successor, and the outgoing edge
3313 is not complex, then we have an IF-THEN-ELSE combo. */
3314 else if (single_succ_p (else_bb
)
3315 && single_succ (then_bb
) == single_succ (else_bb
)
3316 && single_pred_p (else_bb
)
3317 && ! (single_succ_edge (else_bb
)->flags
& EDGE_COMPLEX
)
3318 && ! (epilogue_completed
&& tablejump_p (BB_END (else_bb
), NULL
, NULL
)))
3319 join_bb
= single_succ (else_bb
);
3321 /* Otherwise it is not an IF-THEN or IF-THEN-ELSE combination. */
3325 num_possible_if_blocks
++;
3330 "\nIF-THEN%s block found, pass %d, start block %d "
3331 "[insn %d], then %d [%d]",
3332 (else_bb
) ? "-ELSE" : "",
3335 BB_HEAD (test_bb
) ? (int)INSN_UID (BB_HEAD (test_bb
)) : -1,
3337 BB_HEAD (then_bb
) ? (int)INSN_UID (BB_HEAD (then_bb
)) : -1);
3340 fprintf (dump_file
, ", else %d [%d]",
3342 BB_HEAD (else_bb
) ? (int)INSN_UID (BB_HEAD (else_bb
)) : -1);
3344 fprintf (dump_file
, ", join %d [%d]",
3346 BB_HEAD (join_bb
) ? (int)INSN_UID (BB_HEAD (join_bb
)) : -1);
3348 if (ce_info
->num_multiple_test_blocks
> 0)
3349 fprintf (dump_file
, ", %d %s block%s last test %d [%d]",
3350 ce_info
->num_multiple_test_blocks
,
3351 (ce_info
->and_and_p
) ? "&&" : "||",
3352 (ce_info
->num_multiple_test_blocks
== 1) ? "" : "s",
3353 ce_info
->last_test_bb
->index
,
3354 ((BB_HEAD (ce_info
->last_test_bb
))
3355 ? (int)INSN_UID (BB_HEAD (ce_info
->last_test_bb
))
3358 fputc ('\n', dump_file
);
3361 /* Make sure IF, THEN, and ELSE, blocks are adjacent. Actually, we get the
3362 first condition for free, since we've already asserted that there's a
3363 fallthru edge from IF to THEN. Likewise for the && and || blocks, since
3364 we checked the FALLTHRU flag, those are already adjacent to the last IF
3366 /* ??? As an enhancement, move the ELSE block. Have to deal with
3367 BLOCK notes, if by no other means than backing out the merge if they
3368 exist. Sticky enough I don't want to think about it now. */
3370 if (else_bb
&& (next
= next
->next_bb
) != else_bb
)
3372 if ((next
= next
->next_bb
) != join_bb
&& join_bb
!= EXIT_BLOCK_PTR
)
3380 /* Do the real work. */
3382 ce_info
->else_bb
= else_bb
;
3383 ce_info
->join_bb
= join_bb
;
3385 /* If we have && and || tests, try to first handle combining the && and ||
3386 tests into the conditional code, and if that fails, go back and handle
3387 it without the && and ||, which at present handles the && case if there
3388 was no ELSE block. */
3389 if (cond_exec_process_if_block (ce_info
, TRUE
))
3392 if (ce_info
->num_multiple_test_blocks
)
3396 if (cond_exec_process_if_block (ce_info
, FALSE
))
3403 /* Convert a branch over a trap, or a branch
3404 to a trap, into a conditional trap. */
3407 find_cond_trap (basic_block test_bb
, edge then_edge
, edge else_edge
)
3409 basic_block then_bb
= then_edge
->dest
;
3410 basic_block else_bb
= else_edge
->dest
;
3411 basic_block other_bb
, trap_bb
;
3412 rtx trap
, jump
, cond
, cond_earliest
, seq
;
3415 /* Locate the block with the trap instruction. */
3416 /* ??? While we look for no successors, we really ought to allow
3417 EH successors. Need to fix merge_if_block for that to work. */
3418 if ((trap
= block_has_only_trap (then_bb
)) != NULL
)
3419 trap_bb
= then_bb
, other_bb
= else_bb
;
3420 else if ((trap
= block_has_only_trap (else_bb
)) != NULL
)
3421 trap_bb
= else_bb
, other_bb
= then_bb
;
3427 fprintf (dump_file
, "\nTRAP-IF block found, start %d, trap %d\n",
3428 test_bb
->index
, trap_bb
->index
);
3431 /* If this is not a standard conditional jump, we can't parse it. */
3432 jump
= BB_END (test_bb
);
3433 cond
= noce_get_condition (jump
, &cond_earliest
, false);
3437 /* If the conditional jump is more than just a conditional jump, then
3438 we can not do if-conversion on this block. */
3439 if (! onlyjump_p (jump
))
3442 /* We must be comparing objects whose modes imply the size. */
3443 if (GET_MODE (XEXP (cond
, 0)) == BLKmode
)
3446 /* Reverse the comparison code, if necessary. */
3447 code
= GET_CODE (cond
);
3448 if (then_bb
== trap_bb
)
3450 code
= reversed_comparison_code (cond
, jump
);
3451 if (code
== UNKNOWN
)
3455 /* Attempt to generate the conditional trap. */
3456 seq
= gen_cond_trap (code
, copy_rtx (XEXP (cond
, 0)),
3457 copy_rtx (XEXP (cond
, 1)),
3458 TRAP_CODE (PATTERN (trap
)));
3462 /* Emit the new insns before cond_earliest. */
3463 emit_insn_before_setloc (seq
, cond_earliest
, INSN_LOCATOR (trap
));
3465 /* Delete the trap block if possible. */
3466 remove_edge (trap_bb
== then_bb
? then_edge
: else_edge
);
3467 df_set_bb_dirty (test_bb
);
3468 df_set_bb_dirty (then_bb
);
3469 df_set_bb_dirty (else_bb
);
3471 if (EDGE_COUNT (trap_bb
->preds
) == 0)
3473 delete_basic_block (trap_bb
);
3477 /* Wire together the blocks again. */
3478 if (current_ir_type () == IR_RTL_CFGLAYOUT
)
3479 single_succ_edge (test_bb
)->flags
|= EDGE_FALLTHRU
;
3484 lab
= JUMP_LABEL (jump
);
3485 newjump
= emit_jump_insn_after (gen_jump (lab
), jump
);
3486 LABEL_NUSES (lab
) += 1;
3487 JUMP_LABEL (newjump
) = lab
;
3488 emit_barrier_after (newjump
);
3492 if (can_merge_blocks_p (test_bb
, other_bb
))
3494 merge_blocks (test_bb
, other_bb
);
3498 num_updated_if_blocks
++;
3502 /* Subroutine of find_cond_trap: if BB contains only a trap insn,
3506 block_has_only_trap (basic_block bb
)
3510 /* We're not the exit block. */
3511 if (bb
== EXIT_BLOCK_PTR
)
3514 /* The block must have no successors. */
3515 if (EDGE_COUNT (bb
->succs
) > 0)
3518 /* The only instruction in the THEN block must be the trap. */
3519 trap
= first_active_insn (bb
);
3520 if (! (trap
== BB_END (bb
)
3521 && GET_CODE (PATTERN (trap
)) == TRAP_IF
3522 && TRAP_CONDITION (PATTERN (trap
)) == const_true_rtx
))
3528 /* Look for IF-THEN-ELSE cases in which one of THEN or ELSE is
3529 transformable, but not necessarily the other. There need be no
3532 Return TRUE if we were successful at converting the block.
3534 Cases we'd like to look at:
3537 if (test) goto over; // x not live
3545 if (! test) goto label;
3548 if (test) goto E; // x not live
3562 (3) // This one's really only interesting for targets that can do
3563 // multiway branching, e.g. IA-64 BBB bundles. For other targets
3564 // it results in multiple branches on a cache line, which often
3565 // does not sit well with predictors.
3567 if (test1) goto E; // predicted not taken
3583 (A) Don't do (2) if the branch is predicted against the block we're
3584 eliminating. Do it anyway if we can eliminate a branch; this requires
3585 that the sole successor of the eliminated block postdominate the other
3588 (B) With CE, on (3) we can steal from both sides of the if, creating
3597 Again, this is most useful if J postdominates.
3599 (C) CE substitutes for helpful life information.
3601 (D) These heuristics need a lot of work. */
3603 /* Tests for case 1 above. */
3606 find_if_case_1 (basic_block test_bb
, edge then_edge
, edge else_edge
)
3608 basic_block then_bb
= then_edge
->dest
;
3609 basic_block else_bb
= else_edge
->dest
;
3613 /* If we are partitioning hot/cold basic blocks, we don't want to
3614 mess up unconditional or indirect jumps that cross between hot
3617 Basic block partitioning may result in some jumps that appear to
3618 be optimizable (or blocks that appear to be mergeable), but which really
3619 must be left untouched (they are required to make it safely across
3620 partition boundaries). See the comments at the top of
3621 bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */
3623 if ((BB_END (then_bb
)
3624 && find_reg_note (BB_END (then_bb
), REG_CROSSING_JUMP
, NULL_RTX
))
3625 || (BB_END (test_bb
)
3626 && find_reg_note (BB_END (test_bb
), REG_CROSSING_JUMP
, NULL_RTX
))
3627 || (BB_END (else_bb
)
3628 && find_reg_note (BB_END (else_bb
), REG_CROSSING_JUMP
,
3632 /* THEN has one successor. */
3633 if (!single_succ_p (then_bb
))
3636 /* THEN does not fall through, but is not strange either. */
3637 if (single_succ_edge (then_bb
)->flags
& (EDGE_COMPLEX
| EDGE_FALLTHRU
))
3640 /* THEN has one predecessor. */
3641 if (!single_pred_p (then_bb
))
3644 /* THEN must do something. */
3645 if (forwarder_block_p (then_bb
))
3648 num_possible_if_blocks
++;
3651 "\nIF-CASE-1 found, start %d, then %d\n",
3652 test_bb
->index
, then_bb
->index
);
3654 /* THEN is small. */
3655 if (! cheap_bb_rtx_cost_p (then_bb
,
3656 COSTS_N_INSNS (BRANCH_COST (optimize_bb_for_speed_p (then_edge
->src
),
3657 predictable_edge_p (then_edge
)))))
3660 /* Registers set are dead, or are predicable. */
3661 if (! dead_or_predicable (test_bb
, then_bb
, else_bb
,
3662 single_succ (then_bb
), 1))
3665 /* Conversion went ok, including moving the insns and fixing up the
3666 jump. Adjust the CFG to match. */
3668 /* We can avoid creating a new basic block if then_bb is immediately
3669 followed by else_bb, i.e. deleting then_bb allows test_bb to fall
3672 if (then_bb
->next_bb
== else_bb
3673 && then_bb
->prev_bb
== test_bb
3674 && else_bb
!= EXIT_BLOCK_PTR
)
3676 redirect_edge_succ (FALLTHRU_EDGE (test_bb
), else_bb
);
3680 new_bb
= redirect_edge_and_branch_force (FALLTHRU_EDGE (test_bb
),
3683 df_set_bb_dirty (test_bb
);
3684 df_set_bb_dirty (else_bb
);
3686 then_bb_index
= then_bb
->index
;
3687 delete_basic_block (then_bb
);
3689 /* Make rest of code believe that the newly created block is the THEN_BB
3690 block we removed. */
3693 df_bb_replace (then_bb_index
, new_bb
);
3694 /* Since the fallthru edge was redirected from test_bb to new_bb,
3695 we need to ensure that new_bb is in the same partition as
3696 test bb (you can not fall through across section boundaries). */
3697 BB_COPY_PARTITION (new_bb
, test_bb
);
3701 num_updated_if_blocks
++;
3706 /* Test for case 2 above. */
3709 find_if_case_2 (basic_block test_bb
, edge then_edge
, edge else_edge
)
3711 basic_block then_bb
= then_edge
->dest
;
3712 basic_block else_bb
= else_edge
->dest
;
3716 /* If we are partitioning hot/cold basic blocks, we don't want to
3717 mess up unconditional or indirect jumps that cross between hot
3720 Basic block partitioning may result in some jumps that appear to
3721 be optimizable (or blocks that appear to be mergeable), but which really
3722 must be left untouched (they are required to make it safely across
3723 partition boundaries). See the comments at the top of
3724 bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */
3726 if ((BB_END (then_bb
)
3727 && find_reg_note (BB_END (then_bb
), REG_CROSSING_JUMP
, NULL_RTX
))
3728 || (BB_END (test_bb
)
3729 && find_reg_note (BB_END (test_bb
), REG_CROSSING_JUMP
, NULL_RTX
))
3730 || (BB_END (else_bb
)
3731 && find_reg_note (BB_END (else_bb
), REG_CROSSING_JUMP
,
3735 /* ELSE has one successor. */
3736 if (!single_succ_p (else_bb
))
3739 else_succ
= single_succ_edge (else_bb
);
3741 /* ELSE outgoing edge is not complex. */
3742 if (else_succ
->flags
& EDGE_COMPLEX
)
3745 /* ELSE has one predecessor. */
3746 if (!single_pred_p (else_bb
))
3749 /* THEN is not EXIT. */
3750 if (then_bb
->index
< NUM_FIXED_BLOCKS
)
3753 /* ELSE is predicted or SUCC(ELSE) postdominates THEN. */
3754 note
= find_reg_note (BB_END (test_bb
), REG_BR_PROB
, NULL_RTX
);
3755 if (note
&& INTVAL (XEXP (note
, 0)) >= REG_BR_PROB_BASE
/ 2)
3757 else if (else_succ
->dest
->index
< NUM_FIXED_BLOCKS
3758 || dominated_by_p (CDI_POST_DOMINATORS
, then_bb
,
3764 num_possible_if_blocks
++;
3767 "\nIF-CASE-2 found, start %d, else %d\n",
3768 test_bb
->index
, else_bb
->index
);
3770 /* ELSE is small. */
3771 if (! cheap_bb_rtx_cost_p (else_bb
,
3772 COSTS_N_INSNS (BRANCH_COST (optimize_bb_for_speed_p (else_edge
->src
),
3773 predictable_edge_p (else_edge
)))))
3776 /* Registers set are dead, or are predicable. */
3777 if (! dead_or_predicable (test_bb
, else_bb
, then_bb
, else_succ
->dest
, 0))
3780 /* Conversion went ok, including moving the insns and fixing up the
3781 jump. Adjust the CFG to match. */
3783 df_set_bb_dirty (test_bb
);
3784 df_set_bb_dirty (then_bb
);
3785 delete_basic_block (else_bb
);
3788 num_updated_if_blocks
++;
3790 /* ??? We may now fallthru from one of THEN's successors into a join
3791 block. Rerun cleanup_cfg? Examine things manually? Wait? */
3796 /* A subroutine of dead_or_predicable called through for_each_rtx.
3797 Return 1 if a memory is found. */
3800 find_memory (rtx
*px
, void *data ATTRIBUTE_UNUSED
)
3805 /* Used by the code above to perform the actual rtl transformations.
3806 Return TRUE if successful.
3808 TEST_BB is the block containing the conditional branch. MERGE_BB
3809 is the block containing the code to manipulate. NEW_DEST is the
3810 label TEST_BB should be branching to after the conversion.
3811 REVERSEP is true if the sense of the branch should be reversed. */
3814 dead_or_predicable (basic_block test_bb
, basic_block merge_bb
,
3815 basic_block other_bb
, basic_block new_dest
, int reversep
)
3817 rtx head
, end
, jump
, earliest
= NULL_RTX
, old_dest
, new_label
= NULL_RTX
;
3818 /* Number of pending changes. */
3819 int n_validated_changes
= 0;
3821 jump
= BB_END (test_bb
);
3823 /* Find the extent of the real code in the merge block. */
3824 head
= BB_HEAD (merge_bb
);
3825 end
= BB_END (merge_bb
);
3827 while (DEBUG_INSN_P (end
) && end
!= head
)
3828 end
= PREV_INSN (end
);
3830 /* If merge_bb ends with a tablejump, predicating/moving insn's
3831 into test_bb and then deleting merge_bb will result in the jumptable
3832 that follows merge_bb being removed along with merge_bb and then we
3833 get an unresolved reference to the jumptable. */
3834 if (tablejump_p (end
, NULL
, NULL
))
3838 head
= NEXT_INSN (head
);
3839 while (DEBUG_INSN_P (head
) && head
!= end
)
3840 head
= NEXT_INSN (head
);
3845 head
= end
= NULL_RTX
;
3848 head
= NEXT_INSN (head
);
3849 while (DEBUG_INSN_P (head
) && head
!= end
)
3850 head
= NEXT_INSN (head
);
3857 head
= end
= NULL_RTX
;
3860 end
= PREV_INSN (end
);
3861 while (DEBUG_INSN_P (end
) && end
!= head
)
3862 end
= PREV_INSN (end
);
3865 /* Disable handling dead code by conditional execution if the machine needs
3866 to do anything funny with the tests, etc. */
3867 #ifndef IFCVT_MODIFY_TESTS
3868 if (HAVE_conditional_execution
)
3870 /* In the conditional execution case, we have things easy. We know
3871 the condition is reversible. We don't have to check life info
3872 because we're going to conditionally execute the code anyway.
3873 All that's left is making sure the insns involved can actually
3878 cond
= cond_exec_get_condition (jump
);
3882 prob_val
= find_reg_note (jump
, REG_BR_PROB
, NULL_RTX
);
3884 prob_val
= XEXP (prob_val
, 0);
3888 enum rtx_code rev
= reversed_comparison_code (cond
, jump
);
3891 cond
= gen_rtx_fmt_ee (rev
, GET_MODE (cond
), XEXP (cond
, 0),
3894 prob_val
= GEN_INT (REG_BR_PROB_BASE
- INTVAL (prob_val
));
3897 if (cond_exec_process_insns (NULL
, head
, end
, cond
, prob_val
, 0)
3898 && verify_changes (0))
3899 n_validated_changes
= num_validated_changes ();
3906 /* Try the NCE path if the CE path did not result in any changes. */
3907 if (n_validated_changes
== 0)
3909 /* In the non-conditional execution case, we have to verify that there
3910 are no trapping operations, no calls, no references to memory, and
3911 that any registers modified are dead at the branch site. */
3913 rtx insn
, cond
, prev
;
3914 bitmap merge_set
, test_live
, test_set
;
3915 unsigned i
, fail
= 0;
3918 /* Check for no calls or trapping operations. */
3919 for (insn
= head
; ; insn
= NEXT_INSN (insn
))
3923 if (NONDEBUG_INSN_P (insn
))
3925 if (may_trap_p (PATTERN (insn
)))
3928 /* ??? Even non-trapping memories such as stack frame
3929 references must be avoided. For stores, we collect
3930 no lifetime info; for reads, we'd have to assert
3931 true_dependence false against every store in the
3933 if (for_each_rtx (&PATTERN (insn
), find_memory
, NULL
))
3940 if (! any_condjump_p (jump
))
3943 /* Find the extent of the conditional. */
3944 cond
= noce_get_condition (jump
, &earliest
, false);
3949 MERGE_SET = set of registers set in MERGE_BB
3950 TEST_LIVE = set of registers live at EARLIEST
3951 TEST_SET = set of registers set between EARLIEST and the
3952 end of the block. */
3954 merge_set
= BITMAP_ALLOC (®_obstack
);
3955 test_live
= BITMAP_ALLOC (®_obstack
);
3956 test_set
= BITMAP_ALLOC (®_obstack
);
3958 /* ??? bb->local_set is only valid during calculate_global_regs_live,
3959 so we must recompute usage for MERGE_BB. Not so bad, I suppose,
3960 since we've already asserted that MERGE_BB is small. */
3961 /* If we allocated new pseudos (e.g. in the conditional move
3962 expander called from noce_emit_cmove), we must resize the
3964 if (max_regno
< max_reg_num ())
3965 max_regno
= max_reg_num ();
3967 FOR_BB_INSNS (merge_bb
, insn
)
3969 if (NONDEBUG_INSN_P (insn
))
3971 unsigned int uid
= INSN_UID (insn
);
3973 for (def_rec
= DF_INSN_UID_DEFS (uid
); *def_rec
; def_rec
++)
3975 df_ref def
= *def_rec
;
3976 bitmap_set_bit (merge_set
, DF_REF_REGNO (def
));
3981 /* For small register class machines, don't lengthen lifetimes of
3982 hard registers before reload. */
3983 if (SMALL_REGISTER_CLASSES
&& ! reload_completed
)
3985 EXECUTE_IF_SET_IN_BITMAP (merge_set
, 0, i
, bi
)
3987 if (i
< FIRST_PSEUDO_REGISTER
3989 && ! global_regs
[i
])
3994 /* For TEST, we're interested in a range of insns, not a whole block.
3995 Moreover, we're interested in the insns live from OTHER_BB. */
3997 /* The loop below takes the set of live registers
3998 after JUMP, and calculates the live set before EARLIEST. */
3999 bitmap_copy (test_live
, df_get_live_in (other_bb
));
4000 df_simulate_initialize_backwards (test_bb
, test_live
);
4001 for (insn
= jump
; ; insn
= prev
)
4005 df_simulate_find_defs (insn
, test_set
);
4006 df_simulate_one_insn_backwards (test_bb
, insn
, test_live
);
4008 prev
= PREV_INSN (insn
);
4009 if (insn
== earliest
)
4013 /* We can perform the transformation if
4014 MERGE_SET & (TEST_SET | TEST_LIVE)
4016 TEST_SET & DF_LIVE_IN (merge_bb)
4019 if (bitmap_intersect_p (test_set
, merge_set
)
4020 || bitmap_intersect_p (test_live
, merge_set
)
4021 || bitmap_intersect_p (test_set
, df_get_live_in (merge_bb
)))
4024 BITMAP_FREE (merge_set
);
4025 BITMAP_FREE (test_live
);
4026 BITMAP_FREE (test_set
);
4033 /* We don't want to use normal invert_jump or redirect_jump because
4034 we don't want to delete_insn called. Also, we want to do our own
4035 change group management. */
4037 old_dest
= JUMP_LABEL (jump
);
4038 if (other_bb
!= new_dest
)
4040 new_label
= block_label (new_dest
);
4042 ? ! invert_jump_1 (jump
, new_label
)
4043 : ! redirect_jump_1 (jump
, new_label
))
4047 if (verify_changes (n_validated_changes
))
4048 confirm_change_group ();
4052 if (other_bb
!= new_dest
)
4054 redirect_jump_2 (jump
, old_dest
, new_label
, 0, reversep
);
4056 redirect_edge_succ (BRANCH_EDGE (test_bb
), new_dest
);
4059 gcov_type count
, probability
;
4060 count
= BRANCH_EDGE (test_bb
)->count
;
4061 BRANCH_EDGE (test_bb
)->count
= FALLTHRU_EDGE (test_bb
)->count
;
4062 FALLTHRU_EDGE (test_bb
)->count
= count
;
4063 probability
= BRANCH_EDGE (test_bb
)->probability
;
4064 BRANCH_EDGE (test_bb
)->probability
4065 = FALLTHRU_EDGE (test_bb
)->probability
;
4066 FALLTHRU_EDGE (test_bb
)->probability
= probability
;
4067 update_br_prob_note (test_bb
);
4071 /* Move the insns out of MERGE_BB to before the branch. */
4076 if (end
== BB_END (merge_bb
))
4077 BB_END (merge_bb
) = PREV_INSN (head
);
4079 /* PR 21767: When moving insns above a conditional branch, REG_EQUAL
4080 notes might become invalid. */
4086 if (! INSN_P (insn
))
4088 note
= find_reg_note (insn
, REG_EQUAL
, NULL_RTX
);
4091 set
= single_set (insn
);
4092 if (!set
|| !function_invariant_p (SET_SRC (set
)))
4093 remove_note (insn
, note
);
4094 } while (insn
!= end
&& (insn
= NEXT_INSN (insn
)));
4096 reorder_insns (head
, end
, PREV_INSN (earliest
));
4099 /* Remove the jump and edge if we can. */
4100 if (other_bb
== new_dest
)
4103 remove_edge (BRANCH_EDGE (test_bb
));
4104 /* ??? Can't merge blocks here, as then_bb is still in use.
4105 At minimum, the merge will get done just before bb-reorder. */
4115 /* Main entry point for all if-conversion. */
4125 df_live_add_problem ();
4126 df_live_set_all_dirty ();
4129 num_possible_if_blocks
= 0;
4130 num_updated_if_blocks
= 0;
4131 num_true_changes
= 0;
4133 loop_optimizer_init (AVOID_CFG_MODIFICATIONS
);
4134 mark_loop_exit_edges ();
4135 loop_optimizer_finalize ();
4136 free_dominance_info (CDI_DOMINATORS
);
4138 /* Compute postdominators. */
4139 calculate_dominance_info (CDI_POST_DOMINATORS
);
4141 df_set_flags (DF_LR_RUN_DCE
);
4143 /* Go through each of the basic blocks looking for things to convert. If we
4144 have conditional execution, we make multiple passes to allow us to handle
4145 IF-THEN{-ELSE} blocks within other IF-THEN{-ELSE} blocks. */
4150 /* Only need to do dce on the first pass. */
4151 df_clear_flags (DF_LR_RUN_DCE
);
4152 cond_exec_changed_p
= FALSE
;
4155 #ifdef IFCVT_MULTIPLE_DUMPS
4156 if (dump_file
&& pass
> 1)
4157 fprintf (dump_file
, "\n\n========== Pass %d ==========\n", pass
);
4163 while (!df_get_bb_dirty (bb
)
4164 && (new_bb
= find_if_header (bb
, pass
)) != NULL
)
4168 #ifdef IFCVT_MULTIPLE_DUMPS
4169 if (dump_file
&& cond_exec_changed_p
)
4170 print_rtl_with_bb (dump_file
, get_insns ());
4173 while (cond_exec_changed_p
);
4175 #ifdef IFCVT_MULTIPLE_DUMPS
4177 fprintf (dump_file
, "\n\n========== no more changes\n");
4180 free_dominance_info (CDI_POST_DOMINATORS
);
4185 clear_aux_for_blocks ();
4187 /* If we allocated new pseudos, we must resize the array for sched1. */
4188 if (max_regno
< max_reg_num ())
4189 max_regno
= max_reg_num ();
4191 /* Write the final stats. */
4192 if (dump_file
&& num_possible_if_blocks
> 0)
4195 "\n%d possible IF blocks searched.\n",
4196 num_possible_if_blocks
);
4198 "%d IF blocks converted.\n",
4199 num_updated_if_blocks
);
4201 "%d true changes made.\n\n\n",
4206 df_remove_problem (df_live
);
4208 #ifdef ENABLE_CHECKING
4209 verify_flow_info ();
4214 gate_handle_if_conversion (void)
4216 return (optimize
> 0)
4217 && dbg_cnt (if_conversion
);
4220 /* If-conversion and CFG cleanup. */
4222 rest_of_handle_if_conversion (void)
4224 if (flag_if_conversion
)
4227 dump_flow_info (dump_file
, dump_flags
);
4228 cleanup_cfg (CLEANUP_EXPENSIVE
);
4236 struct rtl_opt_pass pass_rtl_ifcvt
=
4241 gate_handle_if_conversion
, /* gate */
4242 rest_of_handle_if_conversion
, /* execute */
4245 0, /* static_pass_number */
4246 TV_IFCVT
, /* tv_id */
4247 0, /* properties_required */
4248 0, /* properties_provided */
4249 0, /* properties_destroyed */
4250 0, /* todo_flags_start */
4251 TODO_df_finish
| TODO_verify_rtl_sharing
|
4252 TODO_dump_func
/* todo_flags_finish */
4257 gate_handle_if_after_combine (void)
4259 return optimize
> 0 && flag_if_conversion
4260 && dbg_cnt (if_after_combine
);
4264 /* Rerun if-conversion, as combine may have simplified things enough
4265 to now meet sequence length restrictions. */
4267 rest_of_handle_if_after_combine (void)
4273 struct rtl_opt_pass pass_if_after_combine
=
4278 gate_handle_if_after_combine
, /* gate */
4279 rest_of_handle_if_after_combine
, /* execute */
4282 0, /* static_pass_number */
4283 TV_IFCVT
, /* tv_id */
4284 0, /* properties_required */
4285 0, /* properties_provided */
4286 0, /* properties_destroyed */
4287 0, /* todo_flags_start */
4288 TODO_df_finish
| TODO_verify_rtl_sharing
|
4290 TODO_ggc_collect
/* todo_flags_finish */
4296 gate_handle_if_after_reload (void)
4298 return optimize
> 0 && flag_if_conversion2
4299 && dbg_cnt (if_after_reload
);
4303 rest_of_handle_if_after_reload (void)
4310 struct rtl_opt_pass pass_if_after_reload
=
4315 gate_handle_if_after_reload
, /* gate */
4316 rest_of_handle_if_after_reload
, /* execute */
4319 0, /* static_pass_number */
4320 TV_IFCVT2
, /* tv_id */
4321 0, /* properties_required */
4322 0, /* properties_provided */
4323 0, /* properties_destroyed */
4324 0, /* todo_flags_start */
4325 TODO_df_finish
| TODO_verify_rtl_sharing
|
4327 TODO_ggc_collect
/* todo_flags_finish */