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_move
51 #define HAVE_conditional_move 0
63 #ifndef MAX_CONDITIONAL_EXECUTE
64 #define MAX_CONDITIONAL_EXECUTE \
65 (BRANCH_COST (optimize_function_for_speed_p (cfun), false) \
69 #define IFCVT_MULTIPLE_DUMPS 1
71 #define NULL_BLOCK ((basic_block) NULL)
73 /* # of IF-THEN or IF-THEN-ELSE blocks we looked at */
74 static int num_possible_if_blocks
;
76 /* # of IF-THEN or IF-THEN-ELSE blocks were converted to conditional
78 static int num_updated_if_blocks
;
80 /* # of changes made. */
81 static int num_true_changes
;
83 /* Whether conditional execution changes were made. */
84 static int cond_exec_changed_p
;
86 /* Forward references. */
87 static int count_bb_insns (const_basic_block
);
88 static bool cheap_bb_rtx_cost_p (const_basic_block
, int);
89 static rtx
first_active_insn (basic_block
);
90 static rtx
last_active_insn (basic_block
, int);
91 static basic_block
block_fallthru (basic_block
);
92 static int cond_exec_process_insns (ce_if_block_t
*, rtx
, rtx
, rtx
, rtx
, int);
93 static rtx
cond_exec_get_condition (rtx
);
94 static rtx
noce_get_condition (rtx
, rtx
*, bool);
95 static int noce_operand_ok (const_rtx
);
96 static void merge_if_block (ce_if_block_t
*);
97 static int find_cond_trap (basic_block
, edge
, edge
);
98 static basic_block
find_if_header (basic_block
, int);
99 static int block_jumps_and_fallthru_p (basic_block
, basic_block
);
100 static int noce_find_if_block (basic_block
, edge
, edge
, int);
101 static int cond_exec_find_if_block (ce_if_block_t
*);
102 static int find_if_case_1 (basic_block
, edge
, edge
);
103 static int find_if_case_2 (basic_block
, edge
, edge
);
104 static int find_memory (rtx
*, void *);
105 static int dead_or_predicable (basic_block
, basic_block
, basic_block
,
107 static void noce_emit_move_insn (rtx
, rtx
);
108 static rtx
block_has_only_trap (basic_block
);
110 /* Count the number of non-jump active insns in BB. */
113 count_bb_insns (const_basic_block bb
)
116 rtx insn
= BB_HEAD (bb
);
120 if (CALL_P (insn
) || NONJUMP_INSN_P (insn
))
123 if (insn
== BB_END (bb
))
125 insn
= NEXT_INSN (insn
);
131 /* Determine whether the total insn_rtx_cost on non-jump insns in
132 basic block BB is less than MAX_COST. This function returns
133 false if the cost of any instruction could not be estimated. */
136 cheap_bb_rtx_cost_p (const_basic_block bb
, int max_cost
)
139 rtx insn
= BB_HEAD (bb
);
140 bool speed
= optimize_bb_for_speed_p (bb
);
144 if (NONJUMP_INSN_P (insn
))
146 int cost
= insn_rtx_cost (PATTERN (insn
), speed
);
150 /* If this instruction is the load or set of a "stack" register,
151 such as a floating point register on x87, then the cost of
152 speculatively executing this insn may need to include
153 the additional cost of popping its result off of the
154 register stack. Unfortunately, correctly recognizing and
155 accounting for this additional overhead is tricky, so for
156 now we simply prohibit such speculative execution. */
159 rtx set
= single_set (insn
);
160 if (set
&& STACK_REG_P (SET_DEST (set
)))
166 if (count
>= max_cost
)
169 else if (CALL_P (insn
))
172 if (insn
== BB_END (bb
))
174 insn
= NEXT_INSN (insn
);
180 /* Return the first non-jump active insn in the basic block. */
183 first_active_insn (basic_block bb
)
185 rtx insn
= BB_HEAD (bb
);
189 if (insn
== BB_END (bb
))
191 insn
= NEXT_INSN (insn
);
194 while (NOTE_P (insn
) || DEBUG_INSN_P (insn
))
196 if (insn
== BB_END (bb
))
198 insn
= NEXT_INSN (insn
);
207 /* Return the last non-jump active (non-jump) insn in the basic block. */
210 last_active_insn (basic_block bb
, int skip_use_p
)
212 rtx insn
= BB_END (bb
);
213 rtx head
= BB_HEAD (bb
);
217 || DEBUG_INSN_P (insn
)
219 && NONJUMP_INSN_P (insn
)
220 && GET_CODE (PATTERN (insn
)) == USE
))
224 insn
= PREV_INSN (insn
);
233 /* Return the basic block reached by falling though the basic block BB. */
236 block_fallthru (basic_block bb
)
241 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
242 if (e
->flags
& EDGE_FALLTHRU
)
245 return (e
) ? e
->dest
: NULL_BLOCK
;
248 /* Go through a bunch of insns, converting them to conditional
249 execution format if possible. Return TRUE if all of the non-note
250 insns were processed. */
253 cond_exec_process_insns (ce_if_block_t
*ce_info ATTRIBUTE_UNUSED
,
254 /* if block information */rtx start
,
255 /* first insn to look at */rtx end
,
256 /* last insn to look at */rtx test
,
257 /* conditional execution test */rtx prob_val
,
258 /* probability of branch taken. */int mod_ok
)
260 int must_be_last
= FALSE
;
268 for (insn
= start
; ; insn
= NEXT_INSN (insn
))
270 if (NOTE_P (insn
) || DEBUG_INSN_P (insn
))
273 gcc_assert(NONJUMP_INSN_P (insn
) || CALL_P (insn
));
275 /* Remove USE insns that get in the way. */
276 if (reload_completed
&& GET_CODE (PATTERN (insn
)) == USE
)
278 /* ??? Ug. Actually unlinking the thing is problematic,
279 given what we'd have to coordinate with our callers. */
280 SET_INSN_DELETED (insn
);
284 /* Last insn wasn't last? */
288 if (modified_in_p (test
, insn
))
295 /* Now build the conditional form of the instruction. */
296 pattern
= PATTERN (insn
);
297 xtest
= copy_rtx (test
);
299 /* If this is already a COND_EXEC, rewrite the test to be an AND of the
301 if (GET_CODE (pattern
) == COND_EXEC
)
303 if (GET_MODE (xtest
) != GET_MODE (COND_EXEC_TEST (pattern
)))
306 xtest
= gen_rtx_AND (GET_MODE (xtest
), xtest
,
307 COND_EXEC_TEST (pattern
));
308 pattern
= COND_EXEC_CODE (pattern
);
311 pattern
= gen_rtx_COND_EXEC (VOIDmode
, xtest
, pattern
);
313 /* If the machine needs to modify the insn being conditionally executed,
314 say for example to force a constant integer operand into a temp
315 register, do so here. */
316 #ifdef IFCVT_MODIFY_INSN
317 IFCVT_MODIFY_INSN (ce_info
, pattern
, insn
);
322 validate_change (insn
, &PATTERN (insn
), pattern
, 1);
324 if (CALL_P (insn
) && prob_val
)
325 validate_change (insn
, ®_NOTES (insn
),
326 alloc_EXPR_LIST (REG_BR_PROB
, prob_val
,
327 REG_NOTES (insn
)), 1);
337 /* Return the condition for a jump. Do not do any special processing. */
340 cond_exec_get_condition (rtx jump
)
344 if (any_condjump_p (jump
))
345 test_if
= SET_SRC (pc_set (jump
));
348 cond
= XEXP (test_if
, 0);
350 /* If this branches to JUMP_LABEL when the condition is false,
351 reverse the condition. */
352 if (GET_CODE (XEXP (test_if
, 2)) == LABEL_REF
353 && XEXP (XEXP (test_if
, 2), 0) == JUMP_LABEL (jump
))
355 enum rtx_code rev
= reversed_comparison_code (cond
, jump
);
359 cond
= gen_rtx_fmt_ee (rev
, GET_MODE (cond
), XEXP (cond
, 0),
366 /* Given a simple IF-THEN or IF-THEN-ELSE block, attempt to convert it
367 to conditional execution. Return TRUE if we were successful at
368 converting the block. */
371 cond_exec_process_if_block (ce_if_block_t
* ce_info
,
372 /* if block information */int do_multiple_p
)
374 basic_block test_bb
= ce_info
->test_bb
; /* last test block */
375 basic_block then_bb
= ce_info
->then_bb
; /* THEN */
376 basic_block else_bb
= ce_info
->else_bb
; /* ELSE or NULL */
377 rtx test_expr
; /* expression in IF_THEN_ELSE that is tested */
378 rtx then_start
; /* first insn in THEN block */
379 rtx then_end
; /* last insn + 1 in THEN block */
380 rtx else_start
= NULL_RTX
; /* first insn in ELSE block or NULL */
381 rtx else_end
= NULL_RTX
; /* last insn + 1 in ELSE block */
382 int max
; /* max # of insns to convert. */
383 int then_mod_ok
; /* whether conditional mods are ok in THEN */
384 rtx true_expr
; /* test for else block insns */
385 rtx false_expr
; /* test for then block insns */
386 rtx true_prob_val
; /* probability of else block */
387 rtx false_prob_val
; /* probability of then block */
389 enum rtx_code false_code
;
391 /* If test is comprised of && or || elements, and we've failed at handling
392 all of them together, just use the last test if it is the special case of
393 && elements without an ELSE block. */
394 if (!do_multiple_p
&& ce_info
->num_multiple_test_blocks
)
396 if (else_bb
|| ! ce_info
->and_and_p
)
399 ce_info
->test_bb
= test_bb
= ce_info
->last_test_bb
;
400 ce_info
->num_multiple_test_blocks
= 0;
401 ce_info
->num_and_and_blocks
= 0;
402 ce_info
->num_or_or_blocks
= 0;
405 /* Find the conditional jump to the ELSE or JOIN part, and isolate
407 test_expr
= cond_exec_get_condition (BB_END (test_bb
));
411 /* If the conditional jump is more than just a conditional jump,
412 then we can not do conditional execution conversion on this block. */
413 if (! onlyjump_p (BB_END (test_bb
)))
416 /* Collect the bounds of where we're to search, skipping any labels, jumps
417 and notes at the beginning and end of the block. Then count the total
418 number of insns and see if it is small enough to convert. */
419 then_start
= first_active_insn (then_bb
);
420 then_end
= last_active_insn (then_bb
, TRUE
);
421 n_insns
= ce_info
->num_then_insns
= count_bb_insns (then_bb
);
422 max
= MAX_CONDITIONAL_EXECUTE
;
427 else_start
= first_active_insn (else_bb
);
428 else_end
= last_active_insn (else_bb
, TRUE
);
429 n_insns
+= ce_info
->num_else_insns
= count_bb_insns (else_bb
);
435 /* Map test_expr/test_jump into the appropriate MD tests to use on
436 the conditionally executed code. */
438 true_expr
= test_expr
;
440 false_code
= reversed_comparison_code (true_expr
, BB_END (test_bb
));
441 if (false_code
!= UNKNOWN
)
442 false_expr
= gen_rtx_fmt_ee (false_code
, GET_MODE (true_expr
),
443 XEXP (true_expr
, 0), XEXP (true_expr
, 1));
445 false_expr
= NULL_RTX
;
447 #ifdef IFCVT_MODIFY_TESTS
448 /* If the machine description needs to modify the tests, such as setting a
449 conditional execution register from a comparison, it can do so here. */
450 IFCVT_MODIFY_TESTS (ce_info
, true_expr
, false_expr
);
452 /* See if the conversion failed. */
453 if (!true_expr
|| !false_expr
)
457 true_prob_val
= find_reg_note (BB_END (test_bb
), REG_BR_PROB
, NULL_RTX
);
460 true_prob_val
= XEXP (true_prob_val
, 0);
461 false_prob_val
= GEN_INT (REG_BR_PROB_BASE
- INTVAL (true_prob_val
));
464 false_prob_val
= NULL_RTX
;
466 /* If we have && or || tests, do them here. These tests are in the adjacent
467 blocks after the first block containing the test. */
468 if (ce_info
->num_multiple_test_blocks
> 0)
470 basic_block bb
= test_bb
;
471 basic_block last_test_bb
= ce_info
->last_test_bb
;
480 enum rtx_code f_code
;
482 bb
= block_fallthru (bb
);
483 start
= first_active_insn (bb
);
484 end
= last_active_insn (bb
, TRUE
);
486 && ! cond_exec_process_insns (ce_info
, start
, end
, false_expr
,
487 false_prob_val
, FALSE
))
490 /* If the conditional jump is more than just a conditional jump, then
491 we can not do conditional execution conversion on this block. */
492 if (! onlyjump_p (BB_END (bb
)))
495 /* Find the conditional jump and isolate the test. */
496 t
= cond_exec_get_condition (BB_END (bb
));
500 f_code
= reversed_comparison_code (t
, BB_END (bb
));
501 if (f_code
== UNKNOWN
)
504 f
= gen_rtx_fmt_ee (f_code
, GET_MODE (t
), XEXP (t
, 0), XEXP (t
, 1));
505 if (ce_info
->and_and_p
)
507 t
= gen_rtx_AND (GET_MODE (t
), true_expr
, t
);
508 f
= gen_rtx_IOR (GET_MODE (t
), false_expr
, f
);
512 t
= gen_rtx_IOR (GET_MODE (t
), true_expr
, t
);
513 f
= gen_rtx_AND (GET_MODE (t
), false_expr
, f
);
516 /* If the machine description needs to modify the tests, such as
517 setting a conditional execution register from a comparison, it can
519 #ifdef IFCVT_MODIFY_MULTIPLE_TESTS
520 IFCVT_MODIFY_MULTIPLE_TESTS (ce_info
, bb
, t
, f
);
522 /* See if the conversion failed. */
530 while (bb
!= last_test_bb
);
533 /* For IF-THEN-ELSE blocks, we don't allow modifications of the test
534 on then THEN block. */
535 then_mod_ok
= (else_bb
== NULL_BLOCK
);
537 /* Go through the THEN and ELSE blocks converting the insns if possible
538 to conditional execution. */
542 || ! cond_exec_process_insns (ce_info
, then_start
, then_end
,
543 false_expr
, false_prob_val
,
547 if (else_bb
&& else_end
548 && ! cond_exec_process_insns (ce_info
, else_start
, else_end
,
549 true_expr
, true_prob_val
, TRUE
))
552 /* If we cannot apply the changes, fail. Do not go through the normal fail
553 processing, since apply_change_group will call cancel_changes. */
554 if (! apply_change_group ())
556 #ifdef IFCVT_MODIFY_CANCEL
557 /* Cancel any machine dependent changes. */
558 IFCVT_MODIFY_CANCEL (ce_info
);
563 #ifdef IFCVT_MODIFY_FINAL
564 /* Do any machine dependent final modifications. */
565 IFCVT_MODIFY_FINAL (ce_info
);
568 /* Conversion succeeded. */
570 fprintf (dump_file
, "%d insn%s converted to conditional execution.\n",
571 n_insns
, (n_insns
== 1) ? " was" : "s were");
573 /* Merge the blocks! */
574 merge_if_block (ce_info
);
575 cond_exec_changed_p
= TRUE
;
579 #ifdef IFCVT_MODIFY_CANCEL
580 /* Cancel any machine dependent changes. */
581 IFCVT_MODIFY_CANCEL (ce_info
);
588 /* Used by noce_process_if_block to communicate with its subroutines.
590 The subroutines know that A and B may be evaluated freely. They
591 know that X is a register. They should insert new instructions
592 before cond_earliest. */
596 /* The basic blocks that make up the IF-THEN-{ELSE-,}JOIN block. */
597 basic_block test_bb
, then_bb
, else_bb
, join_bb
;
599 /* The jump that ends TEST_BB. */
602 /* The jump condition. */
605 /* New insns should be inserted before this one. */
608 /* Insns in the THEN and ELSE block. There is always just this
609 one insns in those blocks. The insns are single_set insns.
610 If there was no ELSE block, INSN_B is the last insn before
611 COND_EARLIEST, or NULL_RTX. In the former case, the insn
612 operands are still valid, as if INSN_B was moved down below
616 /* The SET_SRC of INSN_A and INSN_B. */
619 /* The SET_DEST of INSN_A. */
622 /* True if this if block is not canonical. In the canonical form of
623 if blocks, the THEN_BB is the block reached via the fallthru edge
624 from TEST_BB. For the noce transformations, we allow the symmetric
626 bool then_else_reversed
;
628 /* Estimated cost of the particular branch instruction. */
632 static rtx
noce_emit_store_flag (struct noce_if_info
*, rtx
, int, int);
633 static int noce_try_move (struct noce_if_info
*);
634 static int noce_try_store_flag (struct noce_if_info
*);
635 static int noce_try_addcc (struct noce_if_info
*);
636 static int noce_try_store_flag_constants (struct noce_if_info
*);
637 static int noce_try_store_flag_mask (struct noce_if_info
*);
638 static rtx
noce_emit_cmove (struct noce_if_info
*, rtx
, enum rtx_code
, rtx
,
640 static int noce_try_cmove (struct noce_if_info
*);
641 static int noce_try_cmove_arith (struct noce_if_info
*);
642 static rtx
noce_get_alt_condition (struct noce_if_info
*, rtx
, rtx
*);
643 static int noce_try_minmax (struct noce_if_info
*);
644 static int noce_try_abs (struct noce_if_info
*);
645 static int noce_try_sign_mask (struct noce_if_info
*);
647 /* Helper function for noce_try_store_flag*. */
650 noce_emit_store_flag (struct noce_if_info
*if_info
, rtx x
, int reversep
,
653 rtx cond
= if_info
->cond
;
657 cond_complex
= (! general_operand (XEXP (cond
, 0), VOIDmode
)
658 || ! general_operand (XEXP (cond
, 1), VOIDmode
));
660 /* If earliest == jump, or when the condition is complex, try to
661 build the store_flag insn directly. */
665 rtx set
= pc_set (if_info
->jump
);
666 cond
= XEXP (SET_SRC (set
), 0);
667 if (GET_CODE (XEXP (SET_SRC (set
), 2)) == LABEL_REF
668 && XEXP (XEXP (SET_SRC (set
), 2), 0) == JUMP_LABEL (if_info
->jump
))
669 reversep
= !reversep
;
670 if (if_info
->then_else_reversed
)
671 reversep
= !reversep
;
675 code
= reversed_comparison_code (cond
, if_info
->jump
);
677 code
= GET_CODE (cond
);
679 if ((if_info
->cond_earliest
== if_info
->jump
|| cond_complex
)
680 && (normalize
== 0 || STORE_FLAG_VALUE
== normalize
))
684 tmp
= gen_rtx_fmt_ee (code
, GET_MODE (x
), XEXP (cond
, 0),
686 tmp
= gen_rtx_SET (VOIDmode
, x
, tmp
);
689 tmp
= emit_insn (tmp
);
691 if (recog_memoized (tmp
) >= 0)
697 if_info
->cond_earliest
= if_info
->jump
;
705 /* Don't even try if the comparison operands or the mode of X are weird. */
706 if (cond_complex
|| !SCALAR_INT_MODE_P (GET_MODE (x
)))
709 return emit_store_flag (x
, code
, XEXP (cond
, 0),
710 XEXP (cond
, 1), VOIDmode
,
711 (code
== LTU
|| code
== LEU
712 || code
== GEU
|| code
== GTU
), normalize
);
715 /* Emit instruction to move an rtx, possibly into STRICT_LOW_PART.
716 X is the destination/target and Y is the value to copy. */
719 noce_emit_move_insn (rtx x
, rtx y
)
721 enum machine_mode outmode
;
725 if (GET_CODE (x
) != STRICT_LOW_PART
)
727 rtx seq
, insn
, target
;
731 /* Check that the SET_SRC is reasonable before calling emit_move_insn,
732 otherwise construct a suitable SET pattern ourselves. */
733 insn
= (OBJECT_P (y
) || CONSTANT_P (y
) || GET_CODE (y
) == SUBREG
)
734 ? emit_move_insn (x
, y
)
735 : emit_insn (gen_rtx_SET (VOIDmode
, x
, y
));
739 if (recog_memoized (insn
) <= 0)
741 if (GET_CODE (x
) == ZERO_EXTRACT
)
743 rtx op
= XEXP (x
, 0);
744 unsigned HOST_WIDE_INT size
= INTVAL (XEXP (x
, 1));
745 unsigned HOST_WIDE_INT start
= INTVAL (XEXP (x
, 2));
747 /* store_bit_field expects START to be relative to
748 BYTES_BIG_ENDIAN and adjusts this value for machines with
749 BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN. In order to be able to
750 invoke store_bit_field again it is necessary to have the START
751 value from the first call. */
752 if (BITS_BIG_ENDIAN
!= BYTES_BIG_ENDIAN
)
755 start
= BITS_PER_UNIT
- start
- size
;
758 gcc_assert (REG_P (op
));
759 start
= BITS_PER_WORD
- start
- size
;
763 gcc_assert (start
< (MEM_P (op
) ? BITS_PER_UNIT
: BITS_PER_WORD
));
764 store_bit_field (op
, size
, start
, GET_MODE (x
), y
);
768 switch (GET_RTX_CLASS (GET_CODE (y
)))
771 ot
= code_to_optab
[GET_CODE (y
)];
775 target
= expand_unop (GET_MODE (y
), ot
, XEXP (y
, 0), x
, 0);
776 if (target
!= NULL_RTX
)
779 emit_move_insn (x
, target
);
788 ot
= code_to_optab
[GET_CODE (y
)];
792 target
= expand_binop (GET_MODE (y
), ot
,
793 XEXP (y
, 0), XEXP (y
, 1),
795 if (target
!= NULL_RTX
)
798 emit_move_insn (x
, target
);
815 inner
= XEXP (outer
, 0);
816 outmode
= GET_MODE (outer
);
817 bitpos
= SUBREG_BYTE (outer
) * BITS_PER_UNIT
;
818 store_bit_field (inner
, GET_MODE_BITSIZE (outmode
), bitpos
, outmode
, y
);
821 /* Return sequence of instructions generated by if conversion. This
822 function calls end_sequence() to end the current stream, ensures
823 that are instructions are unshared, recognizable non-jump insns.
824 On failure, this function returns a NULL_RTX. */
827 end_ifcvt_sequence (struct noce_if_info
*if_info
)
830 rtx seq
= get_insns ();
832 set_used_flags (if_info
->x
);
833 set_used_flags (if_info
->cond
);
834 unshare_all_rtl_in_chain (seq
);
837 /* Make sure that all of the instructions emitted are recognizable,
838 and that we haven't introduced a new jump instruction.
839 As an exercise for the reader, build a general mechanism that
840 allows proper placement of required clobbers. */
841 for (insn
= seq
; insn
; insn
= NEXT_INSN (insn
))
843 || recog_memoized (insn
) == -1)
849 /* Convert "if (a != b) x = a; else x = b" into "x = a" and
850 "if (a == b) x = a; else x = b" into "x = b". */
853 noce_try_move (struct noce_if_info
*if_info
)
855 rtx cond
= if_info
->cond
;
856 enum rtx_code code
= GET_CODE (cond
);
859 if (code
!= NE
&& code
!= EQ
)
862 /* This optimization isn't valid if either A or B could be a NaN
864 if (HONOR_NANS (GET_MODE (if_info
->x
))
865 || HONOR_SIGNED_ZEROS (GET_MODE (if_info
->x
)))
868 /* Check whether the operands of the comparison are A and in
870 if ((rtx_equal_p (if_info
->a
, XEXP (cond
, 0))
871 && rtx_equal_p (if_info
->b
, XEXP (cond
, 1)))
872 || (rtx_equal_p (if_info
->a
, XEXP (cond
, 1))
873 && rtx_equal_p (if_info
->b
, XEXP (cond
, 0))))
875 y
= (code
== EQ
) ? if_info
->a
: if_info
->b
;
877 /* Avoid generating the move if the source is the destination. */
878 if (! rtx_equal_p (if_info
->x
, y
))
881 noce_emit_move_insn (if_info
->x
, y
);
882 seq
= end_ifcvt_sequence (if_info
);
886 emit_insn_before_setloc (seq
, if_info
->jump
,
887 INSN_LOCATOR (if_info
->insn_a
));
894 /* Convert "if (test) x = 1; else x = 0".
896 Only try 0 and STORE_FLAG_VALUE here. Other combinations will be
897 tried in noce_try_store_flag_constants after noce_try_cmove has had
898 a go at the conversion. */
901 noce_try_store_flag (struct noce_if_info
*if_info
)
906 if (CONST_INT_P (if_info
->b
)
907 && INTVAL (if_info
->b
) == STORE_FLAG_VALUE
908 && if_info
->a
== const0_rtx
)
910 else if (if_info
->b
== const0_rtx
911 && CONST_INT_P (if_info
->a
)
912 && INTVAL (if_info
->a
) == STORE_FLAG_VALUE
913 && (reversed_comparison_code (if_info
->cond
, if_info
->jump
)
921 target
= noce_emit_store_flag (if_info
, if_info
->x
, reversep
, 0);
924 if (target
!= if_info
->x
)
925 noce_emit_move_insn (if_info
->x
, target
);
927 seq
= end_ifcvt_sequence (if_info
);
931 emit_insn_before_setloc (seq
, if_info
->jump
,
932 INSN_LOCATOR (if_info
->insn_a
));
942 /* Convert "if (test) x = a; else x = b", for A and B constant. */
945 noce_try_store_flag_constants (struct noce_if_info
*if_info
)
949 HOST_WIDE_INT itrue
, ifalse
, diff
, tmp
;
950 int normalize
, can_reverse
;
951 enum machine_mode mode
;
953 if (CONST_INT_P (if_info
->a
)
954 && CONST_INT_P (if_info
->b
))
956 mode
= GET_MODE (if_info
->x
);
957 ifalse
= INTVAL (if_info
->a
);
958 itrue
= INTVAL (if_info
->b
);
960 /* Make sure we can represent the difference between the two values. */
961 if ((itrue
- ifalse
> 0)
962 != ((ifalse
< 0) != (itrue
< 0) ? ifalse
< 0 : ifalse
< itrue
))
965 diff
= trunc_int_for_mode (itrue
- ifalse
, mode
);
967 can_reverse
= (reversed_comparison_code (if_info
->cond
, if_info
->jump
)
971 if (diff
== STORE_FLAG_VALUE
|| diff
== -STORE_FLAG_VALUE
)
973 else if (ifalse
== 0 && exact_log2 (itrue
) >= 0
974 && (STORE_FLAG_VALUE
== 1
975 || if_info
->branch_cost
>= 2))
977 else if (itrue
== 0 && exact_log2 (ifalse
) >= 0 && can_reverse
978 && (STORE_FLAG_VALUE
== 1 || if_info
->branch_cost
>= 2))
979 normalize
= 1, reversep
= 1;
981 && (STORE_FLAG_VALUE
== -1
982 || if_info
->branch_cost
>= 2))
984 else if (ifalse
== -1 && can_reverse
985 && (STORE_FLAG_VALUE
== -1 || if_info
->branch_cost
>= 2))
986 normalize
= -1, reversep
= 1;
987 else if ((if_info
->branch_cost
>= 2 && STORE_FLAG_VALUE
== -1)
988 || if_info
->branch_cost
>= 3)
995 tmp
= itrue
; itrue
= ifalse
; ifalse
= tmp
;
996 diff
= trunc_int_for_mode (-diff
, mode
);
1000 target
= noce_emit_store_flag (if_info
, if_info
->x
, reversep
, normalize
);
1007 /* if (test) x = 3; else x = 4;
1008 => x = 3 + (test == 0); */
1009 if (diff
== STORE_FLAG_VALUE
|| diff
== -STORE_FLAG_VALUE
)
1011 target
= expand_simple_binop (mode
,
1012 (diff
== STORE_FLAG_VALUE
1014 GEN_INT (ifalse
), target
, if_info
->x
, 0,
1018 /* if (test) x = 8; else x = 0;
1019 => x = (test != 0) << 3; */
1020 else if (ifalse
== 0 && (tmp
= exact_log2 (itrue
)) >= 0)
1022 target
= expand_simple_binop (mode
, ASHIFT
,
1023 target
, GEN_INT (tmp
), if_info
->x
, 0,
1027 /* if (test) x = -1; else x = b;
1028 => x = -(test != 0) | b; */
1029 else if (itrue
== -1)
1031 target
= expand_simple_binop (mode
, IOR
,
1032 target
, GEN_INT (ifalse
), if_info
->x
, 0,
1036 /* if (test) x = a; else x = b;
1037 => x = (-(test != 0) & (b - a)) + a; */
1040 target
= expand_simple_binop (mode
, AND
,
1041 target
, GEN_INT (diff
), if_info
->x
, 0,
1044 target
= expand_simple_binop (mode
, PLUS
,
1045 target
, GEN_INT (ifalse
),
1046 if_info
->x
, 0, OPTAB_WIDEN
);
1055 if (target
!= if_info
->x
)
1056 noce_emit_move_insn (if_info
->x
, target
);
1058 seq
= end_ifcvt_sequence (if_info
);
1062 emit_insn_before_setloc (seq
, if_info
->jump
,
1063 INSN_LOCATOR (if_info
->insn_a
));
1070 /* Convert "if (test) foo++" into "foo += (test != 0)", and
1071 similarly for "foo--". */
1074 noce_try_addcc (struct noce_if_info
*if_info
)
1077 int subtract
, normalize
;
1079 if (GET_CODE (if_info
->a
) == PLUS
1080 && rtx_equal_p (XEXP (if_info
->a
, 0), if_info
->b
)
1081 && (reversed_comparison_code (if_info
->cond
, if_info
->jump
)
1084 rtx cond
= if_info
->cond
;
1085 enum rtx_code code
= reversed_comparison_code (cond
, if_info
->jump
);
1087 /* First try to use addcc pattern. */
1088 if (general_operand (XEXP (cond
, 0), VOIDmode
)
1089 && general_operand (XEXP (cond
, 1), VOIDmode
))
1092 target
= emit_conditional_add (if_info
->x
, code
,
1097 XEXP (if_info
->a
, 1),
1098 GET_MODE (if_info
->x
),
1099 (code
== LTU
|| code
== GEU
1100 || code
== LEU
|| code
== GTU
));
1103 if (target
!= if_info
->x
)
1104 noce_emit_move_insn (if_info
->x
, target
);
1106 seq
= end_ifcvt_sequence (if_info
);
1110 emit_insn_before_setloc (seq
, if_info
->jump
,
1111 INSN_LOCATOR (if_info
->insn_a
));
1117 /* If that fails, construct conditional increment or decrement using
1119 if (if_info
->branch_cost
>= 2
1120 && (XEXP (if_info
->a
, 1) == const1_rtx
1121 || XEXP (if_info
->a
, 1) == constm1_rtx
))
1124 if (STORE_FLAG_VALUE
== INTVAL (XEXP (if_info
->a
, 1)))
1125 subtract
= 0, normalize
= 0;
1126 else if (-STORE_FLAG_VALUE
== INTVAL (XEXP (if_info
->a
, 1)))
1127 subtract
= 1, normalize
= 0;
1129 subtract
= 0, normalize
= INTVAL (XEXP (if_info
->a
, 1));
1132 target
= noce_emit_store_flag (if_info
,
1133 gen_reg_rtx (GET_MODE (if_info
->x
)),
1137 target
= expand_simple_binop (GET_MODE (if_info
->x
),
1138 subtract
? MINUS
: PLUS
,
1139 if_info
->b
, target
, if_info
->x
,
1143 if (target
!= if_info
->x
)
1144 noce_emit_move_insn (if_info
->x
, target
);
1146 seq
= end_ifcvt_sequence (if_info
);
1150 emit_insn_before_setloc (seq
, if_info
->jump
,
1151 INSN_LOCATOR (if_info
->insn_a
));
1161 /* Convert "if (test) x = 0;" to "x &= -(test == 0);" */
1164 noce_try_store_flag_mask (struct noce_if_info
*if_info
)
1170 if ((if_info
->branch_cost
>= 2
1171 || STORE_FLAG_VALUE
== -1)
1172 && ((if_info
->a
== const0_rtx
1173 && rtx_equal_p (if_info
->b
, if_info
->x
))
1174 || ((reversep
= (reversed_comparison_code (if_info
->cond
,
1177 && if_info
->b
== const0_rtx
1178 && rtx_equal_p (if_info
->a
, if_info
->x
))))
1181 target
= noce_emit_store_flag (if_info
,
1182 gen_reg_rtx (GET_MODE (if_info
->x
)),
1185 target
= expand_simple_binop (GET_MODE (if_info
->x
), AND
,
1187 target
, if_info
->x
, 0,
1192 if (target
!= if_info
->x
)
1193 noce_emit_move_insn (if_info
->x
, target
);
1195 seq
= end_ifcvt_sequence (if_info
);
1199 emit_insn_before_setloc (seq
, if_info
->jump
,
1200 INSN_LOCATOR (if_info
->insn_a
));
1210 /* Helper function for noce_try_cmove and noce_try_cmove_arith. */
1213 noce_emit_cmove (struct noce_if_info
*if_info
, rtx x
, enum rtx_code code
,
1214 rtx cmp_a
, rtx cmp_b
, rtx vfalse
, rtx vtrue
)
1216 /* If earliest == jump, try to build the cmove insn directly.
1217 This is helpful when combine has created some complex condition
1218 (like for alpha's cmovlbs) that we can't hope to regenerate
1219 through the normal interface. */
1221 if (if_info
->cond_earliest
== if_info
->jump
)
1225 tmp
= gen_rtx_fmt_ee (code
, GET_MODE (if_info
->cond
), cmp_a
, cmp_b
);
1226 tmp
= gen_rtx_IF_THEN_ELSE (GET_MODE (x
), tmp
, vtrue
, vfalse
);
1227 tmp
= gen_rtx_SET (VOIDmode
, x
, tmp
);
1230 tmp
= emit_insn (tmp
);
1232 if (recog_memoized (tmp
) >= 0)
1244 /* Don't even try if the comparison operands are weird. */
1245 if (! general_operand (cmp_a
, GET_MODE (cmp_a
))
1246 || ! general_operand (cmp_b
, GET_MODE (cmp_b
)))
1249 #if HAVE_conditional_move
1250 return emit_conditional_move (x
, code
, cmp_a
, cmp_b
, VOIDmode
,
1251 vtrue
, vfalse
, GET_MODE (x
),
1252 (code
== LTU
|| code
== GEU
1253 || code
== LEU
|| code
== GTU
));
1255 /* We'll never get here, as noce_process_if_block doesn't call the
1256 functions involved. Ifdef code, however, should be discouraged
1257 because it leads to typos in the code not selected. However,
1258 emit_conditional_move won't exist either. */
1263 /* Try only simple constants and registers here. More complex cases
1264 are handled in noce_try_cmove_arith after noce_try_store_flag_arith
1265 has had a go at it. */
1268 noce_try_cmove (struct noce_if_info
*if_info
)
1273 if ((CONSTANT_P (if_info
->a
) || register_operand (if_info
->a
, VOIDmode
))
1274 && (CONSTANT_P (if_info
->b
) || register_operand (if_info
->b
, VOIDmode
)))
1278 code
= GET_CODE (if_info
->cond
);
1279 target
= noce_emit_cmove (if_info
, if_info
->x
, code
,
1280 XEXP (if_info
->cond
, 0),
1281 XEXP (if_info
->cond
, 1),
1282 if_info
->a
, if_info
->b
);
1286 if (target
!= if_info
->x
)
1287 noce_emit_move_insn (if_info
->x
, target
);
1289 seq
= end_ifcvt_sequence (if_info
);
1293 emit_insn_before_setloc (seq
, if_info
->jump
,
1294 INSN_LOCATOR (if_info
->insn_a
));
1307 /* Try more complex cases involving conditional_move. */
1310 noce_try_cmove_arith (struct noce_if_info
*if_info
)
1322 /* A conditional move from two memory sources is equivalent to a
1323 conditional on their addresses followed by a load. Don't do this
1324 early because it'll screw alias analysis. Note that we've
1325 already checked for no side effects. */
1326 /* ??? FIXME: Magic number 5. */
1327 if (cse_not_expected
1328 && MEM_P (a
) && MEM_P (b
)
1329 && MEM_ADDR_SPACE (a
) == MEM_ADDR_SPACE (b
)
1330 && if_info
->branch_cost
>= 5)
1332 enum machine_mode address_mode
1333 = targetm
.addr_space
.address_mode (MEM_ADDR_SPACE (a
));
1337 x
= gen_reg_rtx (address_mode
);
1341 /* ??? We could handle this if we knew that a load from A or B could
1342 not fault. This is also true if we've already loaded
1343 from the address along the path from ENTRY. */
1344 else if (may_trap_p (a
) || may_trap_p (b
))
1347 /* if (test) x = a + b; else x = c - d;
1354 code
= GET_CODE (if_info
->cond
);
1355 insn_a
= if_info
->insn_a
;
1356 insn_b
= if_info
->insn_b
;
1358 /* Total insn_rtx_cost should be smaller than branch cost. Exit
1359 if insn_rtx_cost can't be estimated. */
1362 insn_cost
= insn_rtx_cost (PATTERN (insn_a
),
1363 optimize_bb_for_speed_p (BLOCK_FOR_INSN (insn_a
)));
1364 if (insn_cost
== 0 || insn_cost
> COSTS_N_INSNS (if_info
->branch_cost
))
1372 insn_cost
+= insn_rtx_cost (PATTERN (insn_b
),
1373 optimize_bb_for_speed_p (BLOCK_FOR_INSN (insn_b
)));
1374 if (insn_cost
== 0 || insn_cost
> COSTS_N_INSNS (if_info
->branch_cost
))
1378 /* Possibly rearrange operands to make things come out more natural. */
1379 if (reversed_comparison_code (if_info
->cond
, if_info
->jump
) != UNKNOWN
)
1382 if (rtx_equal_p (b
, x
))
1384 else if (general_operand (b
, GET_MODE (b
)))
1389 code
= reversed_comparison_code (if_info
->cond
, if_info
->jump
);
1390 tmp
= a
, a
= b
, b
= tmp
;
1391 tmp
= insn_a
, insn_a
= insn_b
, insn_b
= tmp
;
1400 /* If either operand is complex, load it into a register first.
1401 The best way to do this is to copy the original insn. In this
1402 way we preserve any clobbers etc that the insn may have had.
1403 This is of course not possible in the IS_MEM case. */
1404 if (! general_operand (a
, GET_MODE (a
)))
1410 tmp
= gen_reg_rtx (GET_MODE (a
));
1411 tmp
= emit_insn (gen_rtx_SET (VOIDmode
, tmp
, a
));
1414 goto end_seq_and_fail
;
1417 a
= gen_reg_rtx (GET_MODE (a
));
1418 tmp
= copy_rtx (insn_a
);
1419 set
= single_set (tmp
);
1421 tmp
= emit_insn (PATTERN (tmp
));
1423 if (recog_memoized (tmp
) < 0)
1424 goto end_seq_and_fail
;
1426 if (! general_operand (b
, GET_MODE (b
)))
1432 tmp
= gen_reg_rtx (GET_MODE (b
));
1433 tmp
= gen_rtx_SET (VOIDmode
, tmp
, b
);
1436 goto end_seq_and_fail
;
1439 b
= gen_reg_rtx (GET_MODE (b
));
1440 tmp
= copy_rtx (insn_b
);
1441 set
= single_set (tmp
);
1443 tmp
= PATTERN (tmp
);
1446 /* If insn to set up A clobbers any registers B depends on, try to
1447 swap insn that sets up A with the one that sets up B. If even
1448 that doesn't help, punt. */
1449 last
= get_last_insn ();
1450 if (last
&& modified_in_p (orig_b
, last
))
1452 tmp
= emit_insn_before (tmp
, get_insns ());
1453 if (modified_in_p (orig_a
, tmp
))
1454 goto end_seq_and_fail
;
1457 tmp
= emit_insn (tmp
);
1459 if (recog_memoized (tmp
) < 0)
1460 goto end_seq_and_fail
;
1463 target
= noce_emit_cmove (if_info
, x
, code
, XEXP (if_info
->cond
, 0),
1464 XEXP (if_info
->cond
, 1), a
, b
);
1467 goto end_seq_and_fail
;
1469 /* If we're handling a memory for above, emit the load now. */
1472 tmp
= gen_rtx_MEM (GET_MODE (if_info
->x
), target
);
1474 /* Copy over flags as appropriate. */
1475 if (MEM_VOLATILE_P (if_info
->a
) || MEM_VOLATILE_P (if_info
->b
))
1476 MEM_VOLATILE_P (tmp
) = 1;
1477 if (MEM_IN_STRUCT_P (if_info
->a
) && MEM_IN_STRUCT_P (if_info
->b
))
1478 MEM_IN_STRUCT_P (tmp
) = 1;
1479 if (MEM_SCALAR_P (if_info
->a
) && MEM_SCALAR_P (if_info
->b
))
1480 MEM_SCALAR_P (tmp
) = 1;
1481 if (MEM_ALIAS_SET (if_info
->a
) == MEM_ALIAS_SET (if_info
->b
))
1482 set_mem_alias_set (tmp
, MEM_ALIAS_SET (if_info
->a
));
1484 MIN (MEM_ALIGN (if_info
->a
), MEM_ALIGN (if_info
->b
)));
1486 gcc_assert (MEM_ADDR_SPACE (if_info
->a
) == MEM_ADDR_SPACE (if_info
->b
));
1487 set_mem_addr_space (tmp
, MEM_ADDR_SPACE (if_info
->a
));
1489 noce_emit_move_insn (if_info
->x
, tmp
);
1491 else if (target
!= x
)
1492 noce_emit_move_insn (x
, target
);
1494 tmp
= end_ifcvt_sequence (if_info
);
1498 emit_insn_before_setloc (tmp
, if_info
->jump
, INSN_LOCATOR (if_info
->insn_a
));
1506 /* For most cases, the simplified condition we found is the best
1507 choice, but this is not the case for the min/max/abs transforms.
1508 For these we wish to know that it is A or B in the condition. */
1511 noce_get_alt_condition (struct noce_if_info
*if_info
, rtx target
,
1514 rtx cond
, set
, insn
;
1517 /* If target is already mentioned in the known condition, return it. */
1518 if (reg_mentioned_p (target
, if_info
->cond
))
1520 *earliest
= if_info
->cond_earliest
;
1521 return if_info
->cond
;
1524 set
= pc_set (if_info
->jump
);
1525 cond
= XEXP (SET_SRC (set
), 0);
1527 = GET_CODE (XEXP (SET_SRC (set
), 2)) == LABEL_REF
1528 && XEXP (XEXP (SET_SRC (set
), 2), 0) == JUMP_LABEL (if_info
->jump
);
1529 if (if_info
->then_else_reversed
)
1532 /* If we're looking for a constant, try to make the conditional
1533 have that constant in it. There are two reasons why it may
1534 not have the constant we want:
1536 1. GCC may have needed to put the constant in a register, because
1537 the target can't compare directly against that constant. For
1538 this case, we look for a SET immediately before the comparison
1539 that puts a constant in that register.
1541 2. GCC may have canonicalized the conditional, for example
1542 replacing "if x < 4" with "if x <= 3". We can undo that (or
1543 make equivalent types of changes) to get the constants we need
1544 if they're off by one in the right direction. */
1546 if (CONST_INT_P (target
))
1548 enum rtx_code code
= GET_CODE (if_info
->cond
);
1549 rtx op_a
= XEXP (if_info
->cond
, 0);
1550 rtx op_b
= XEXP (if_info
->cond
, 1);
1553 /* First, look to see if we put a constant in a register. */
1554 prev_insn
= prev_nonnote_insn (if_info
->cond_earliest
);
1556 && BLOCK_NUM (prev_insn
) == BLOCK_NUM (if_info
->cond_earliest
)
1557 && INSN_P (prev_insn
)
1558 && GET_CODE (PATTERN (prev_insn
)) == SET
)
1560 rtx src
= find_reg_equal_equiv_note (prev_insn
);
1562 src
= SET_SRC (PATTERN (prev_insn
));
1563 if (CONST_INT_P (src
))
1565 if (rtx_equal_p (op_a
, SET_DEST (PATTERN (prev_insn
))))
1567 else if (rtx_equal_p (op_b
, SET_DEST (PATTERN (prev_insn
))))
1570 if (CONST_INT_P (op_a
))
1575 code
= swap_condition (code
);
1580 /* Now, look to see if we can get the right constant by
1581 adjusting the conditional. */
1582 if (CONST_INT_P (op_b
))
1584 HOST_WIDE_INT desired_val
= INTVAL (target
);
1585 HOST_WIDE_INT actual_val
= INTVAL (op_b
);
1590 if (actual_val
== desired_val
+ 1)
1593 op_b
= GEN_INT (desired_val
);
1597 if (actual_val
== desired_val
- 1)
1600 op_b
= GEN_INT (desired_val
);
1604 if (actual_val
== desired_val
- 1)
1607 op_b
= GEN_INT (desired_val
);
1611 if (actual_val
== desired_val
+ 1)
1614 op_b
= GEN_INT (desired_val
);
1622 /* If we made any changes, generate a new conditional that is
1623 equivalent to what we started with, but has the right
1625 if (code
!= GET_CODE (if_info
->cond
)
1626 || op_a
!= XEXP (if_info
->cond
, 0)
1627 || op_b
!= XEXP (if_info
->cond
, 1))
1629 cond
= gen_rtx_fmt_ee (code
, GET_MODE (cond
), op_a
, op_b
);
1630 *earliest
= if_info
->cond_earliest
;
1635 cond
= canonicalize_condition (if_info
->jump
, cond
, reverse
,
1636 earliest
, target
, false, true);
1637 if (! cond
|| ! reg_mentioned_p (target
, cond
))
1640 /* We almost certainly searched back to a different place.
1641 Need to re-verify correct lifetimes. */
1643 /* X may not be mentioned in the range (cond_earliest, jump]. */
1644 for (insn
= if_info
->jump
; insn
!= *earliest
; insn
= PREV_INSN (insn
))
1645 if (INSN_P (insn
) && reg_overlap_mentioned_p (if_info
->x
, PATTERN (insn
)))
1648 /* A and B may not be modified in the range [cond_earliest, jump). */
1649 for (insn
= *earliest
; insn
!= if_info
->jump
; insn
= NEXT_INSN (insn
))
1651 && (modified_in_p (if_info
->a
, insn
)
1652 || modified_in_p (if_info
->b
, insn
)))
1658 /* Convert "if (a < b) x = a; else x = b;" to "x = min(a, b);", etc. */
1661 noce_try_minmax (struct noce_if_info
*if_info
)
1663 rtx cond
, earliest
, target
, seq
;
1664 enum rtx_code code
, op
;
1667 /* ??? Reject modes with NaNs or signed zeros since we don't know how
1668 they will be resolved with an SMIN/SMAX. It wouldn't be too hard
1669 to get the target to tell us... */
1670 if (HONOR_SIGNED_ZEROS (GET_MODE (if_info
->x
))
1671 || HONOR_NANS (GET_MODE (if_info
->x
)))
1674 cond
= noce_get_alt_condition (if_info
, if_info
->a
, &earliest
);
1678 /* Verify the condition is of the form we expect, and canonicalize
1679 the comparison code. */
1680 code
= GET_CODE (cond
);
1681 if (rtx_equal_p (XEXP (cond
, 0), if_info
->a
))
1683 if (! rtx_equal_p (XEXP (cond
, 1), if_info
->b
))
1686 else if (rtx_equal_p (XEXP (cond
, 1), if_info
->a
))
1688 if (! rtx_equal_p (XEXP (cond
, 0), if_info
->b
))
1690 code
= swap_condition (code
);
1695 /* Determine what sort of operation this is. Note that the code is for
1696 a taken branch, so the code->operation mapping appears backwards. */
1729 target
= expand_simple_binop (GET_MODE (if_info
->x
), op
,
1730 if_info
->a
, if_info
->b
,
1731 if_info
->x
, unsignedp
, OPTAB_WIDEN
);
1737 if (target
!= if_info
->x
)
1738 noce_emit_move_insn (if_info
->x
, target
);
1740 seq
= end_ifcvt_sequence (if_info
);
1744 emit_insn_before_setloc (seq
, if_info
->jump
, INSN_LOCATOR (if_info
->insn_a
));
1745 if_info
->cond
= cond
;
1746 if_info
->cond_earliest
= earliest
;
1751 /* Convert "if (a < 0) x = -a; else x = a;" to "x = abs(a);",
1752 "if (a < 0) x = ~a; else x = a;" to "x = one_cmpl_abs(a);",
1756 noce_try_abs (struct noce_if_info
*if_info
)
1758 rtx cond
, earliest
, target
, seq
, a
, b
, c
;
1760 bool one_cmpl
= false;
1762 /* Reject modes with signed zeros. */
1763 if (HONOR_SIGNED_ZEROS (GET_MODE (if_info
->x
)))
1766 /* Recognize A and B as constituting an ABS or NABS. The canonical
1767 form is a branch around the negation, taken when the object is the
1768 first operand of a comparison against 0 that evaluates to true. */
1771 if (GET_CODE (a
) == NEG
&& rtx_equal_p (XEXP (a
, 0), b
))
1773 else if (GET_CODE (b
) == NEG
&& rtx_equal_p (XEXP (b
, 0), a
))
1775 c
= a
; a
= b
; b
= c
;
1778 else if (GET_CODE (a
) == NOT
&& rtx_equal_p (XEXP (a
, 0), b
))
1783 else if (GET_CODE (b
) == NOT
&& rtx_equal_p (XEXP (b
, 0), a
))
1785 c
= a
; a
= b
; b
= c
;
1792 cond
= noce_get_alt_condition (if_info
, b
, &earliest
);
1796 /* Verify the condition is of the form we expect. */
1797 if (rtx_equal_p (XEXP (cond
, 0), b
))
1799 else if (rtx_equal_p (XEXP (cond
, 1), b
))
1807 /* Verify that C is zero. Search one step backward for a
1808 REG_EQUAL note or a simple source if necessary. */
1811 rtx set
, insn
= prev_nonnote_insn (earliest
);
1813 && BLOCK_NUM (insn
) == BLOCK_NUM (earliest
)
1814 && (set
= single_set (insn
))
1815 && rtx_equal_p (SET_DEST (set
), c
))
1817 rtx note
= find_reg_equal_equiv_note (insn
);
1827 && GET_CODE (XEXP (c
, 0)) == SYMBOL_REF
1828 && CONSTANT_POOL_ADDRESS_P (XEXP (c
, 0)))
1829 c
= get_pool_constant (XEXP (c
, 0));
1831 /* Work around funny ideas get_condition has wrt canonicalization.
1832 Note that these rtx constants are known to be CONST_INT, and
1833 therefore imply integer comparisons. */
1834 if (c
== constm1_rtx
&& GET_CODE (cond
) == GT
)
1836 else if (c
== const1_rtx
&& GET_CODE (cond
) == LT
)
1838 else if (c
!= CONST0_RTX (GET_MODE (b
)))
1841 /* Determine what sort of operation this is. */
1842 switch (GET_CODE (cond
))
1861 target
= expand_one_cmpl_abs_nojump (GET_MODE (if_info
->x
), b
,
1864 target
= expand_abs_nojump (GET_MODE (if_info
->x
), b
, if_info
->x
, 1);
1866 /* ??? It's a quandary whether cmove would be better here, especially
1867 for integers. Perhaps combine will clean things up. */
1868 if (target
&& negate
)
1871 target
= expand_simple_unop (GET_MODE (target
), NOT
, target
,
1874 target
= expand_simple_unop (GET_MODE (target
), NEG
, target
,
1884 if (target
!= if_info
->x
)
1885 noce_emit_move_insn (if_info
->x
, target
);
1887 seq
= end_ifcvt_sequence (if_info
);
1891 emit_insn_before_setloc (seq
, if_info
->jump
, INSN_LOCATOR (if_info
->insn_a
));
1892 if_info
->cond
= cond
;
1893 if_info
->cond_earliest
= earliest
;
1898 /* Convert "if (m < 0) x = b; else x = 0;" to "x = (m >> C) & b;". */
1901 noce_try_sign_mask (struct noce_if_info
*if_info
)
1903 rtx cond
, t
, m
, c
, seq
;
1904 enum machine_mode mode
;
1906 bool t_unconditional
;
1908 cond
= if_info
->cond
;
1909 code
= GET_CODE (cond
);
1914 if (if_info
->a
== const0_rtx
)
1916 if ((code
== LT
&& c
== const0_rtx
)
1917 || (code
== LE
&& c
== constm1_rtx
))
1920 else if (if_info
->b
== const0_rtx
)
1922 if ((code
== GE
&& c
== const0_rtx
)
1923 || (code
== GT
&& c
== constm1_rtx
))
1927 if (! t
|| side_effects_p (t
))
1930 /* We currently don't handle different modes. */
1931 mode
= GET_MODE (t
);
1932 if (GET_MODE (m
) != mode
)
1935 /* This is only profitable if T is unconditionally executed/evaluated in the
1936 original insn sequence or T is cheap. The former happens if B is the
1937 non-zero (T) value and if INSN_B was taken from TEST_BB, or there was no
1938 INSN_B which can happen for e.g. conditional stores to memory. For the
1939 cost computation use the block TEST_BB where the evaluation will end up
1940 after the transformation. */
1943 && (if_info
->insn_b
== NULL_RTX
1944 || BLOCK_FOR_INSN (if_info
->insn_b
) == if_info
->test_bb
));
1945 if (!(t_unconditional
1946 || (rtx_cost (t
, SET
, optimize_bb_for_speed_p (if_info
->test_bb
))
1947 < COSTS_N_INSNS (2))))
1951 /* Use emit_store_flag to generate "m < 0 ? -1 : 0" instead of expanding
1952 "(signed) m >> 31" directly. This benefits targets with specialized
1953 insns to obtain the signmask, but still uses ashr_optab otherwise. */
1954 m
= emit_store_flag (gen_reg_rtx (mode
), LT
, m
, const0_rtx
, mode
, 0, -1);
1955 t
= m
? expand_binop (mode
, and_optab
, m
, t
, NULL_RTX
, 0, OPTAB_DIRECT
)
1964 noce_emit_move_insn (if_info
->x
, t
);
1966 seq
= end_ifcvt_sequence (if_info
);
1970 emit_insn_before_setloc (seq
, if_info
->jump
, INSN_LOCATOR (if_info
->insn_a
));
1975 /* Optimize away "if (x & C) x |= C" and similar bit manipulation
1979 noce_try_bitop (struct noce_if_info
*if_info
)
1981 rtx cond
, x
, a
, result
, seq
;
1982 enum machine_mode mode
;
1987 cond
= if_info
->cond
;
1988 code
= GET_CODE (cond
);
1990 /* Check for no else condition. */
1991 if (! rtx_equal_p (x
, if_info
->b
))
1994 /* Check for a suitable condition. */
1995 if (code
!= NE
&& code
!= EQ
)
1997 if (XEXP (cond
, 1) != const0_rtx
)
1999 cond
= XEXP (cond
, 0);
2001 /* ??? We could also handle AND here. */
2002 if (GET_CODE (cond
) == ZERO_EXTRACT
)
2004 if (XEXP (cond
, 1) != const1_rtx
2005 || !CONST_INT_P (XEXP (cond
, 2))
2006 || ! rtx_equal_p (x
, XEXP (cond
, 0)))
2008 bitnum
= INTVAL (XEXP (cond
, 2));
2009 mode
= GET_MODE (x
);
2010 if (BITS_BIG_ENDIAN
)
2011 bitnum
= GET_MODE_BITSIZE (mode
) - 1 - bitnum
;
2012 if (bitnum
< 0 || bitnum
>= HOST_BITS_PER_WIDE_INT
)
2019 if (GET_CODE (a
) == IOR
|| GET_CODE (a
) == XOR
)
2021 /* Check for "if (X & C) x = x op C". */
2022 if (! rtx_equal_p (x
, XEXP (a
, 0))
2023 || !CONST_INT_P (XEXP (a
, 1))
2024 || (INTVAL (XEXP (a
, 1)) & GET_MODE_MASK (mode
))
2025 != (unsigned HOST_WIDE_INT
) 1 << bitnum
)
2028 /* if ((x & C) == 0) x |= C; is transformed to x |= C. */
2029 /* if ((x & C) != 0) x |= C; is transformed to nothing. */
2030 if (GET_CODE (a
) == IOR
)
2031 result
= (code
== NE
) ? a
: NULL_RTX
;
2032 else if (code
== NE
)
2034 /* if ((x & C) == 0) x ^= C; is transformed to x |= C. */
2035 result
= gen_int_mode ((HOST_WIDE_INT
) 1 << bitnum
, mode
);
2036 result
= simplify_gen_binary (IOR
, mode
, x
, result
);
2040 /* if ((x & C) != 0) x ^= C; is transformed to x &= ~C. */
2041 result
= gen_int_mode (~((HOST_WIDE_INT
) 1 << bitnum
), mode
);
2042 result
= simplify_gen_binary (AND
, mode
, x
, result
);
2045 else if (GET_CODE (a
) == AND
)
2047 /* Check for "if (X & C) x &= ~C". */
2048 if (! rtx_equal_p (x
, XEXP (a
, 0))
2049 || !CONST_INT_P (XEXP (a
, 1))
2050 || (INTVAL (XEXP (a
, 1)) & GET_MODE_MASK (mode
))
2051 != (~((HOST_WIDE_INT
) 1 << bitnum
) & GET_MODE_MASK (mode
)))
2054 /* if ((x & C) == 0) x &= ~C; is transformed to nothing. */
2055 /* if ((x & C) != 0) x &= ~C; is transformed to x &= ~C. */
2056 result
= (code
== EQ
) ? a
: NULL_RTX
;
2064 noce_emit_move_insn (x
, result
);
2065 seq
= end_ifcvt_sequence (if_info
);
2069 emit_insn_before_setloc (seq
, if_info
->jump
,
2070 INSN_LOCATOR (if_info
->insn_a
));
2076 /* Similar to get_condition, only the resulting condition must be
2077 valid at JUMP, instead of at EARLIEST.
2079 If THEN_ELSE_REVERSED is true, the fallthrough does not go to the
2080 THEN block of the caller, and we have to reverse the condition. */
2083 noce_get_condition (rtx jump
, rtx
*earliest
, bool then_else_reversed
)
2088 if (! any_condjump_p (jump
))
2091 set
= pc_set (jump
);
2093 /* If this branches to JUMP_LABEL when the condition is false,
2094 reverse the condition. */
2095 reverse
= (GET_CODE (XEXP (SET_SRC (set
), 2)) == LABEL_REF
2096 && XEXP (XEXP (SET_SRC (set
), 2), 0) == JUMP_LABEL (jump
));
2098 /* We may have to reverse because the caller's if block is not canonical,
2099 i.e. the THEN block isn't the fallthrough block for the TEST block
2100 (see find_if_header). */
2101 if (then_else_reversed
)
2104 /* If the condition variable is a register and is MODE_INT, accept it. */
2106 cond
= XEXP (SET_SRC (set
), 0);
2107 tmp
= XEXP (cond
, 0);
2108 if (REG_P (tmp
) && GET_MODE_CLASS (GET_MODE (tmp
)) == MODE_INT
)
2113 cond
= gen_rtx_fmt_ee (reverse_condition (GET_CODE (cond
)),
2114 GET_MODE (cond
), tmp
, XEXP (cond
, 1));
2118 /* Otherwise, fall back on canonicalize_condition to do the dirty
2119 work of manipulating MODE_CC values and COMPARE rtx codes. */
2120 return canonicalize_condition (jump
, cond
, reverse
, earliest
,
2121 NULL_RTX
, false, true);
2124 /* Return true if OP is ok for if-then-else processing. */
2127 noce_operand_ok (const_rtx op
)
2129 /* We special-case memories, so handle any of them with
2130 no address side effects. */
2132 return ! side_effects_p (XEXP (op
, 0));
2134 if (side_effects_p (op
))
2137 return ! may_trap_p (op
);
2140 /* Return true if a write into MEM may trap or fault. */
2143 noce_mem_write_may_trap_or_fault_p (const_rtx mem
)
2147 if (MEM_READONLY_P (mem
))
2150 if (may_trap_or_fault_p (mem
))
2153 addr
= XEXP (mem
, 0);
2155 /* Call target hook to avoid the effects of -fpic etc.... */
2156 addr
= targetm
.delegitimize_address (addr
);
2159 switch (GET_CODE (addr
))
2167 addr
= XEXP (addr
, 0);
2171 addr
= XEXP (addr
, 1);
2174 if (CONST_INT_P (XEXP (addr
, 1)))
2175 addr
= XEXP (addr
, 0);
2182 if (SYMBOL_REF_DECL (addr
)
2183 && decl_readonly_section (SYMBOL_REF_DECL (addr
), 0))
2193 /* Return whether we can use store speculation for MEM. TOP_BB is the
2194 basic block above the conditional block where we are considering
2195 doing the speculative store. We look for whether MEM is set
2196 unconditionally later in the function. */
2199 noce_can_store_speculate_p (basic_block top_bb
, const_rtx mem
)
2201 basic_block dominator
;
2203 for (dominator
= get_immediate_dominator (CDI_POST_DOMINATORS
, top_bb
);
2205 dominator
= get_immediate_dominator (CDI_POST_DOMINATORS
, dominator
))
2209 FOR_BB_INSNS (dominator
, insn
)
2211 /* If we see something that might be a memory barrier, we
2212 have to stop looking. Even if the MEM is set later in
2213 the function, we still don't want to set it
2214 unconditionally before the barrier. */
2216 && (volatile_insn_p (PATTERN (insn
))
2217 || (CALL_P (insn
) && (!RTL_CONST_CALL_P (insn
)))))
2220 if (memory_modified_in_insn_p (mem
, insn
))
2222 if (modified_in_p (XEXP (mem
, 0), insn
))
2231 /* Given a simple IF-THEN-JOIN or IF-THEN-ELSE-JOIN block, attempt to convert
2232 it without using conditional execution. Return TRUE if we were successful
2233 at converting the block. */
2236 noce_process_if_block (struct noce_if_info
*if_info
)
2238 basic_block test_bb
= if_info
->test_bb
; /* test block */
2239 basic_block then_bb
= if_info
->then_bb
; /* THEN */
2240 basic_block else_bb
= if_info
->else_bb
; /* ELSE or NULL */
2241 basic_block join_bb
= if_info
->join_bb
; /* JOIN */
2242 rtx jump
= if_info
->jump
;
2243 rtx cond
= if_info
->cond
;
2246 rtx orig_x
, x
, a
, b
;
2248 /* We're looking for patterns of the form
2250 (1) if (...) x = a; else x = b;
2251 (2) x = b; if (...) x = a;
2252 (3) if (...) x = a; // as if with an initial x = x.
2254 The later patterns require jumps to be more expensive.
2256 ??? For future expansion, look for multiple X in such patterns. */
2258 /* Look for one of the potential sets. */
2259 insn_a
= first_active_insn (then_bb
);
2261 || insn_a
!= last_active_insn (then_bb
, FALSE
)
2262 || (set_a
= single_set (insn_a
)) == NULL_RTX
)
2265 x
= SET_DEST (set_a
);
2266 a
= SET_SRC (set_a
);
2268 /* Look for the other potential set. Make sure we've got equivalent
2270 /* ??? This is overconservative. Storing to two different mems is
2271 as easy as conditionally computing the address. Storing to a
2272 single mem merely requires a scratch memory to use as one of the
2273 destination addresses; often the memory immediately below the
2274 stack pointer is available for this. */
2278 insn_b
= first_active_insn (else_bb
);
2280 || insn_b
!= last_active_insn (else_bb
, FALSE
)
2281 || (set_b
= single_set (insn_b
)) == NULL_RTX
2282 || ! rtx_equal_p (x
, SET_DEST (set_b
)))
2287 insn_b
= prev_nonnote_insn (if_info
->cond_earliest
);
2288 while (insn_b
&& DEBUG_INSN_P (insn_b
))
2289 insn_b
= prev_nonnote_insn (insn_b
);
2290 /* We're going to be moving the evaluation of B down from above
2291 COND_EARLIEST to JUMP. Make sure the relevant data is still
2294 || BLOCK_NUM (insn_b
) != BLOCK_NUM (if_info
->cond_earliest
)
2295 || !NONJUMP_INSN_P (insn_b
)
2296 || (set_b
= single_set (insn_b
)) == NULL_RTX
2297 || ! rtx_equal_p (x
, SET_DEST (set_b
))
2298 || ! noce_operand_ok (SET_SRC (set_b
))
2299 || reg_overlap_mentioned_p (x
, SET_SRC (set_b
))
2300 || modified_between_p (SET_SRC (set_b
), insn_b
, jump
)
2301 /* Likewise with X. In particular this can happen when
2302 noce_get_condition looks farther back in the instruction
2303 stream than one might expect. */
2304 || reg_overlap_mentioned_p (x
, cond
)
2305 || reg_overlap_mentioned_p (x
, a
)
2306 || modified_between_p (x
, insn_b
, jump
))
2307 insn_b
= set_b
= NULL_RTX
;
2310 /* If x has side effects then only the if-then-else form is safe to
2311 convert. But even in that case we would need to restore any notes
2312 (such as REG_INC) at then end. That can be tricky if
2313 noce_emit_move_insn expands to more than one insn, so disable the
2314 optimization entirely for now if there are side effects. */
2315 if (side_effects_p (x
))
2318 b
= (set_b
? SET_SRC (set_b
) : x
);
2320 /* Only operate on register destinations, and even then avoid extending
2321 the lifetime of hard registers on small register class machines. */
2324 || (SMALL_REGISTER_CLASSES
2325 && REGNO (x
) < FIRST_PSEUDO_REGISTER
))
2327 if (GET_MODE (x
) == BLKmode
)
2330 if (GET_CODE (x
) == ZERO_EXTRACT
2331 && (!CONST_INT_P (XEXP (x
, 1))
2332 || !CONST_INT_P (XEXP (x
, 2))))
2335 x
= gen_reg_rtx (GET_MODE (GET_CODE (x
) == STRICT_LOW_PART
2336 ? XEXP (x
, 0) : x
));
2339 /* Don't operate on sources that may trap or are volatile. */
2340 if (! noce_operand_ok (a
) || ! noce_operand_ok (b
))
2344 /* Set up the info block for our subroutines. */
2345 if_info
->insn_a
= insn_a
;
2346 if_info
->insn_b
= insn_b
;
2351 /* Try optimizations in some approximation of a useful order. */
2352 /* ??? Should first look to see if X is live incoming at all. If it
2353 isn't, we don't need anything but an unconditional set. */
2355 /* Look and see if A and B are really the same. Avoid creating silly
2356 cmove constructs that no one will fix up later. */
2357 if (rtx_equal_p (a
, b
))
2359 /* If we have an INSN_B, we don't have to create any new rtl. Just
2360 move the instruction that we already have. If we don't have an
2361 INSN_B, that means that A == X, and we've got a noop move. In
2362 that case don't do anything and let the code below delete INSN_A. */
2363 if (insn_b
&& else_bb
)
2367 if (else_bb
&& insn_b
== BB_END (else_bb
))
2368 BB_END (else_bb
) = PREV_INSN (insn_b
);
2369 reorder_insns (insn_b
, insn_b
, PREV_INSN (jump
));
2371 /* If there was a REG_EQUAL note, delete it since it may have been
2372 true due to this insn being after a jump. */
2373 if ((note
= find_reg_note (insn_b
, REG_EQUAL
, NULL_RTX
)) != 0)
2374 remove_note (insn_b
, note
);
2378 /* If we have "x = b; if (...) x = a;", and x has side-effects, then
2379 x must be executed twice. */
2380 else if (insn_b
&& side_effects_p (orig_x
))
2387 if (!set_b
&& MEM_P (orig_x
))
2389 /* Disallow the "if (...) x = a;" form (implicit "else x = x;")
2390 for optimizations if writing to x may trap or fault,
2391 i.e. it's a memory other than a static var or a stack slot,
2392 is misaligned on strict aligned machines or is read-only. If
2393 x is a read-only memory, then the program is valid only if we
2394 avoid the store into it. If there are stores on both the
2395 THEN and ELSE arms, then we can go ahead with the conversion;
2396 either the program is broken, or the condition is always
2397 false such that the other memory is selected. */
2398 if (noce_mem_write_may_trap_or_fault_p (orig_x
))
2401 /* Avoid store speculation: given "if (...) x = a" where x is a
2402 MEM, we only want to do the store if x is always set
2403 somewhere in the function. This avoids cases like
2404 if (pthread_mutex_trylock(mutex))
2406 where we only want global_variable to be changed if the mutex
2407 is held. FIXME: This should ideally be expressed directly in
2409 if (!noce_can_store_speculate_p (test_bb
, orig_x
))
2413 if (noce_try_move (if_info
))
2415 if (noce_try_store_flag (if_info
))
2417 if (noce_try_bitop (if_info
))
2419 if (noce_try_minmax (if_info
))
2421 if (noce_try_abs (if_info
))
2423 if (HAVE_conditional_move
2424 && noce_try_cmove (if_info
))
2426 if (! targetm
.have_conditional_execution ())
2428 if (noce_try_store_flag_constants (if_info
))
2430 if (noce_try_addcc (if_info
))
2432 if (noce_try_store_flag_mask (if_info
))
2434 if (HAVE_conditional_move
2435 && noce_try_cmove_arith (if_info
))
2437 if (noce_try_sign_mask (if_info
))
2441 if (!else_bb
&& set_b
)
2443 insn_b
= set_b
= NULL_RTX
;
2452 /* If we used a temporary, fix it up now. */
2458 noce_emit_move_insn (orig_x
, x
);
2460 set_used_flags (orig_x
);
2461 unshare_all_rtl_in_chain (seq
);
2464 emit_insn_before_setloc (seq
, BB_END (test_bb
), INSN_LOCATOR (insn_a
));
2467 /* The original THEN and ELSE blocks may now be removed. The test block
2468 must now jump to the join block. If the test block and the join block
2469 can be merged, do so. */
2472 delete_basic_block (else_bb
);
2476 remove_edge (find_edge (test_bb
, join_bb
));
2478 remove_edge (find_edge (then_bb
, join_bb
));
2479 redirect_edge_and_branch_force (single_succ_edge (test_bb
), join_bb
);
2480 delete_basic_block (then_bb
);
2483 if (can_merge_blocks_p (test_bb
, join_bb
))
2485 merge_blocks (test_bb
, join_bb
);
2489 num_updated_if_blocks
++;
2493 /* Check whether a block is suitable for conditional move conversion.
2494 Every insn must be a simple set of a register to a constant or a
2495 register. For each assignment, store the value in the array VALS,
2496 indexed by register number, then store the register number in
2497 REGS. COND is the condition we will test. */
2500 check_cond_move_block (basic_block bb
, rtx
*vals
, VEC (int, heap
) **regs
, rtx cond
)
2504 /* We can only handle simple jumps at the end of the basic block.
2505 It is almost impossible to update the CFG otherwise. */
2507 if (JUMP_P (insn
) && !onlyjump_p (insn
))
2510 FOR_BB_INSNS (bb
, insn
)
2514 if (!NONDEBUG_INSN_P (insn
) || JUMP_P (insn
))
2516 set
= single_set (insn
);
2520 dest
= SET_DEST (set
);
2521 src
= SET_SRC (set
);
2523 || (SMALL_REGISTER_CLASSES
&& HARD_REGISTER_P (dest
)))
2526 if (!CONSTANT_P (src
) && !register_operand (src
, VOIDmode
))
2529 if (side_effects_p (src
) || side_effects_p (dest
))
2532 if (may_trap_p (src
) || may_trap_p (dest
))
2535 /* Don't try to handle this if the source register was
2536 modified earlier in the block. */
2538 && vals
[REGNO (src
)] != NULL
)
2539 || (GET_CODE (src
) == SUBREG
&& REG_P (SUBREG_REG (src
))
2540 && vals
[REGNO (SUBREG_REG (src
))] != NULL
))
2543 /* Don't try to handle this if the destination register was
2544 modified earlier in the block. */
2545 if (vals
[REGNO (dest
)] != NULL
)
2548 /* Don't try to handle this if the condition uses the
2549 destination register. */
2550 if (reg_overlap_mentioned_p (dest
, cond
))
2553 /* Don't try to handle this if the source register is modified
2554 later in the block. */
2555 if (!CONSTANT_P (src
)
2556 && modified_between_p (src
, insn
, NEXT_INSN (BB_END (bb
))))
2559 vals
[REGNO (dest
)] = src
;
2561 VEC_safe_push (int, heap
, *regs
, REGNO (dest
));
2567 /* Given a basic block BB suitable for conditional move conversion,
2568 a condition COND, and arrays THEN_VALS and ELSE_VALS containing the
2569 register values depending on COND, emit the insns in the block as
2570 conditional moves. If ELSE_BLOCK is true, THEN_BB was already
2571 processed. The caller has started a sequence for the conversion.
2572 Return true if successful, false if something goes wrong. */
2575 cond_move_convert_if_block (struct noce_if_info
*if_infop
,
2576 basic_block bb
, rtx cond
,
2577 rtx
*then_vals
, rtx
*else_vals
,
2581 rtx insn
, cond_arg0
, cond_arg1
;
2583 code
= GET_CODE (cond
);
2584 cond_arg0
= XEXP (cond
, 0);
2585 cond_arg1
= XEXP (cond
, 1);
2587 FOR_BB_INSNS (bb
, insn
)
2589 rtx set
, target
, dest
, t
, e
;
2592 /* ??? Maybe emit conditional debug insn? */
2593 if (!NONDEBUG_INSN_P (insn
) || JUMP_P (insn
))
2595 set
= single_set (insn
);
2596 gcc_assert (set
&& REG_P (SET_DEST (set
)));
2598 dest
= SET_DEST (set
);
2599 regno
= REGNO (dest
);
2601 t
= then_vals
[regno
];
2602 e
= else_vals
[regno
];
2606 /* If this register was set in the then block, we already
2607 handled this case there. */
2620 target
= noce_emit_cmove (if_infop
, dest
, code
, cond_arg0
, cond_arg1
,
2626 noce_emit_move_insn (dest
, target
);
2632 /* Given a simple IF-THEN-JOIN or IF-THEN-ELSE-JOIN block, attempt to convert
2633 it using only conditional moves. Return TRUE if we were successful at
2634 converting the block. */
2637 cond_move_process_if_block (struct noce_if_info
*if_info
)
2639 basic_block test_bb
= if_info
->test_bb
;
2640 basic_block then_bb
= if_info
->then_bb
;
2641 basic_block else_bb
= if_info
->else_bb
;
2642 basic_block join_bb
= if_info
->join_bb
;
2643 rtx jump
= if_info
->jump
;
2644 rtx cond
= if_info
->cond
;
2646 int max_reg
, size
, c
, reg
;
2649 VEC (int, heap
) *then_regs
= NULL
;
2650 VEC (int, heap
) *else_regs
= NULL
;
2653 /* Build a mapping for each block to the value used for each
2655 max_reg
= max_reg_num ();
2656 size
= (max_reg
+ 1) * sizeof (rtx
);
2657 then_vals
= (rtx
*) alloca (size
);
2658 else_vals
= (rtx
*) alloca (size
);
2659 memset (then_vals
, 0, size
);
2660 memset (else_vals
, 0, size
);
2662 /* Make sure the blocks are suitable. */
2663 if (!check_cond_move_block (then_bb
, then_vals
, &then_regs
, cond
)
2664 || (else_bb
&& !check_cond_move_block (else_bb
, else_vals
, &else_regs
, cond
)))
2666 VEC_free (int, heap
, then_regs
);
2667 VEC_free (int, heap
, else_regs
);
2671 /* Make sure the blocks can be used together. If the same register
2672 is set in both blocks, and is not set to a constant in both
2673 cases, then both blocks must set it to the same register. We
2674 have already verified that if it is set to a register, that the
2675 source register does not change after the assignment. Also count
2676 the number of registers set in only one of the blocks. */
2678 for (i
= 0; VEC_iterate (int, then_regs
, i
, reg
); i
++)
2680 if (!then_vals
[reg
] && !else_vals
[reg
])
2683 if (!else_vals
[reg
])
2687 if (!CONSTANT_P (then_vals
[reg
])
2688 && !CONSTANT_P (else_vals
[reg
])
2689 && !rtx_equal_p (then_vals
[reg
], else_vals
[reg
]))
2691 VEC_free (int, heap
, then_regs
);
2692 VEC_free (int, heap
, else_regs
);
2698 /* Finish off c for MAX_CONDITIONAL_EXECUTE. */
2699 for (i
= 0; VEC_iterate (int, else_regs
, i
, reg
); ++i
)
2700 if (!then_vals
[reg
])
2703 /* Make sure it is reasonable to convert this block. What matters
2704 is the number of assignments currently made in only one of the
2705 branches, since if we convert we are going to always execute
2707 if (c
> MAX_CONDITIONAL_EXECUTE
)
2709 VEC_free (int, heap
, then_regs
);
2710 VEC_free (int, heap
, else_regs
);
2714 /* Try to emit the conditional moves. First do the then block,
2715 then do anything left in the else blocks. */
2717 if (!cond_move_convert_if_block (if_info
, then_bb
, cond
,
2718 then_vals
, else_vals
, false)
2720 && !cond_move_convert_if_block (if_info
, else_bb
, cond
,
2721 then_vals
, else_vals
, true)))
2724 VEC_free (int, heap
, then_regs
);
2725 VEC_free (int, heap
, else_regs
);
2728 seq
= end_ifcvt_sequence (if_info
);
2731 VEC_free (int, heap
, then_regs
);
2732 VEC_free (int, heap
, else_regs
);
2736 loc_insn
= first_active_insn (then_bb
);
2739 loc_insn
= first_active_insn (else_bb
);
2740 gcc_assert (loc_insn
);
2742 emit_insn_before_setloc (seq
, jump
, INSN_LOCATOR (loc_insn
));
2746 delete_basic_block (else_bb
);
2750 remove_edge (find_edge (test_bb
, join_bb
));
2752 remove_edge (find_edge (then_bb
, join_bb
));
2753 redirect_edge_and_branch_force (single_succ_edge (test_bb
), join_bb
);
2754 delete_basic_block (then_bb
);
2757 if (can_merge_blocks_p (test_bb
, join_bb
))
2759 merge_blocks (test_bb
, join_bb
);
2763 num_updated_if_blocks
++;
2765 VEC_free (int, heap
, then_regs
);
2766 VEC_free (int, heap
, else_regs
);
2771 /* Determine if a given basic block heads a simple IF-THEN-JOIN or an
2772 IF-THEN-ELSE-JOIN block.
2774 If so, we'll try to convert the insns to not require the branch,
2775 using only transformations that do not require conditional execution.
2777 Return TRUE if we were successful at converting the block. */
2780 noce_find_if_block (basic_block test_bb
,
2781 edge then_edge
, edge else_edge
,
2784 basic_block then_bb
, else_bb
, join_bb
;
2785 bool then_else_reversed
= false;
2788 struct noce_if_info if_info
;
2790 /* We only ever should get here before reload. */
2791 gcc_assert (!reload_completed
);
2793 /* Recognize an IF-THEN-ELSE-JOIN block. */
2794 if (single_pred_p (then_edge
->dest
)
2795 && single_succ_p (then_edge
->dest
)
2796 && single_pred_p (else_edge
->dest
)
2797 && single_succ_p (else_edge
->dest
)
2798 && single_succ (then_edge
->dest
) == single_succ (else_edge
->dest
))
2800 then_bb
= then_edge
->dest
;
2801 else_bb
= else_edge
->dest
;
2802 join_bb
= single_succ (then_bb
);
2804 /* Recognize an IF-THEN-JOIN block. */
2805 else if (single_pred_p (then_edge
->dest
)
2806 && single_succ_p (then_edge
->dest
)
2807 && single_succ (then_edge
->dest
) == else_edge
->dest
)
2809 then_bb
= then_edge
->dest
;
2810 else_bb
= NULL_BLOCK
;
2811 join_bb
= else_edge
->dest
;
2813 /* Recognize an IF-ELSE-JOIN block. We can have those because the order
2814 of basic blocks in cfglayout mode does not matter, so the fallthrough
2815 edge can go to any basic block (and not just to bb->next_bb, like in
2817 else if (single_pred_p (else_edge
->dest
)
2818 && single_succ_p (else_edge
->dest
)
2819 && single_succ (else_edge
->dest
) == then_edge
->dest
)
2821 /* The noce transformations do not apply to IF-ELSE-JOIN blocks.
2822 To make this work, we have to invert the THEN and ELSE blocks
2823 and reverse the jump condition. */
2824 then_bb
= else_edge
->dest
;
2825 else_bb
= NULL_BLOCK
;
2826 join_bb
= single_succ (then_bb
);
2827 then_else_reversed
= true;
2830 /* Not a form we can handle. */
2833 /* The edges of the THEN and ELSE blocks cannot have complex edges. */
2834 if (single_succ_edge (then_bb
)->flags
& EDGE_COMPLEX
)
2837 && single_succ_edge (else_bb
)->flags
& EDGE_COMPLEX
)
2840 num_possible_if_blocks
++;
2845 "\nIF-THEN%s-JOIN block found, pass %d, test %d, then %d",
2846 (else_bb
) ? "-ELSE" : "",
2847 pass
, test_bb
->index
, then_bb
->index
);
2850 fprintf (dump_file
, ", else %d", else_bb
->index
);
2852 fprintf (dump_file
, ", join %d\n", join_bb
->index
);
2855 /* If the conditional jump is more than just a conditional
2856 jump, then we can not do if-conversion on this block. */
2857 jump
= BB_END (test_bb
);
2858 if (! onlyjump_p (jump
))
2861 /* If this is not a standard conditional jump, we can't parse it. */
2862 cond
= noce_get_condition (jump
,
2864 then_else_reversed
);
2868 /* We must be comparing objects whose modes imply the size. */
2869 if (GET_MODE (XEXP (cond
, 0)) == BLKmode
)
2872 /* Initialize an IF_INFO struct to pass around. */
2873 memset (&if_info
, 0, sizeof if_info
);
2874 if_info
.test_bb
= test_bb
;
2875 if_info
.then_bb
= then_bb
;
2876 if_info
.else_bb
= else_bb
;
2877 if_info
.join_bb
= join_bb
;
2878 if_info
.cond
= cond
;
2879 if_info
.cond_earliest
= cond_earliest
;
2880 if_info
.jump
= jump
;
2881 if_info
.then_else_reversed
= then_else_reversed
;
2882 if_info
.branch_cost
= BRANCH_COST (optimize_bb_for_speed_p (test_bb
),
2883 predictable_edge_p (then_edge
));
2885 /* Do the real work. */
2887 if (noce_process_if_block (&if_info
))
2890 if (HAVE_conditional_move
2891 && cond_move_process_if_block (&if_info
))
2898 /* Merge the blocks and mark for local life update. */
2901 merge_if_block (struct ce_if_block
* ce_info
)
2903 basic_block test_bb
= ce_info
->test_bb
; /* last test block */
2904 basic_block then_bb
= ce_info
->then_bb
; /* THEN */
2905 basic_block else_bb
= ce_info
->else_bb
; /* ELSE or NULL */
2906 basic_block join_bb
= ce_info
->join_bb
; /* join block */
2907 basic_block combo_bb
;
2909 /* All block merging is done into the lower block numbers. */
2912 df_set_bb_dirty (test_bb
);
2914 /* Merge any basic blocks to handle && and || subtests. Each of
2915 the blocks are on the fallthru path from the predecessor block. */
2916 if (ce_info
->num_multiple_test_blocks
> 0)
2918 basic_block bb
= test_bb
;
2919 basic_block last_test_bb
= ce_info
->last_test_bb
;
2920 basic_block fallthru
= block_fallthru (bb
);
2925 fallthru
= block_fallthru (bb
);
2926 merge_blocks (combo_bb
, bb
);
2929 while (bb
!= last_test_bb
);
2932 /* Merge TEST block into THEN block. Normally the THEN block won't have a
2933 label, but it might if there were || tests. That label's count should be
2934 zero, and it normally should be removed. */
2938 merge_blocks (combo_bb
, then_bb
);
2942 /* The ELSE block, if it existed, had a label. That label count
2943 will almost always be zero, but odd things can happen when labels
2944 get their addresses taken. */
2947 merge_blocks (combo_bb
, else_bb
);
2951 /* If there was no join block reported, that means it was not adjacent
2952 to the others, and so we cannot merge them. */
2956 rtx last
= BB_END (combo_bb
);
2958 /* The outgoing edge for the current COMBO block should already
2959 be correct. Verify this. */
2960 if (EDGE_COUNT (combo_bb
->succs
) == 0)
2961 gcc_assert (find_reg_note (last
, REG_NORETURN
, NULL
)
2962 || (NONJUMP_INSN_P (last
)
2963 && GET_CODE (PATTERN (last
)) == TRAP_IF
2964 && (TRAP_CONDITION (PATTERN (last
))
2965 == const_true_rtx
)));
2968 /* There should still be something at the end of the THEN or ELSE
2969 blocks taking us to our final destination. */
2970 gcc_assert (JUMP_P (last
)
2971 || (EDGE_SUCC (combo_bb
, 0)->dest
== EXIT_BLOCK_PTR
2973 && SIBLING_CALL_P (last
))
2974 || ((EDGE_SUCC (combo_bb
, 0)->flags
& EDGE_EH
)
2975 && can_throw_internal (last
)));
2978 /* The JOIN block may have had quite a number of other predecessors too.
2979 Since we've already merged the TEST, THEN and ELSE blocks, we should
2980 have only one remaining edge from our if-then-else diamond. If there
2981 is more than one remaining edge, it must come from elsewhere. There
2982 may be zero incoming edges if the THEN block didn't actually join
2983 back up (as with a call to a non-return function). */
2984 else if (EDGE_COUNT (join_bb
->preds
) < 2
2985 && join_bb
!= EXIT_BLOCK_PTR
)
2987 /* We can merge the JOIN cleanly and update the dataflow try
2988 again on this pass.*/
2989 merge_blocks (combo_bb
, join_bb
);
2994 /* We cannot merge the JOIN. */
2996 /* The outgoing edge for the current COMBO block should already
2997 be correct. Verify this. */
2998 gcc_assert (single_succ_p (combo_bb
)
2999 && single_succ (combo_bb
) == join_bb
);
3001 /* Remove the jump and cruft from the end of the COMBO block. */
3002 if (join_bb
!= EXIT_BLOCK_PTR
)
3003 tidy_fallthru_edge (single_succ_edge (combo_bb
));
3006 num_updated_if_blocks
++;
3009 /* Find a block ending in a simple IF condition and try to transform it
3010 in some way. When converting a multi-block condition, put the new code
3011 in the first such block and delete the rest. Return a pointer to this
3012 first block if some transformation was done. Return NULL otherwise. */
3015 find_if_header (basic_block test_bb
, int pass
)
3017 ce_if_block_t ce_info
;
3021 /* The kind of block we're looking for has exactly two successors. */
3022 if (EDGE_COUNT (test_bb
->succs
) != 2)
3025 then_edge
= EDGE_SUCC (test_bb
, 0);
3026 else_edge
= EDGE_SUCC (test_bb
, 1);
3028 if (df_get_bb_dirty (then_edge
->dest
))
3030 if (df_get_bb_dirty (else_edge
->dest
))
3033 /* Neither edge should be abnormal. */
3034 if ((then_edge
->flags
& EDGE_COMPLEX
)
3035 || (else_edge
->flags
& EDGE_COMPLEX
))
3038 /* Nor exit the loop. */
3039 if ((then_edge
->flags
& EDGE_LOOP_EXIT
)
3040 || (else_edge
->flags
& EDGE_LOOP_EXIT
))
3043 /* The THEN edge is canonically the one that falls through. */
3044 if (then_edge
->flags
& EDGE_FALLTHRU
)
3046 else if (else_edge
->flags
& EDGE_FALLTHRU
)
3049 else_edge
= then_edge
;
3053 /* Otherwise this must be a multiway branch of some sort. */
3056 memset (&ce_info
, '\0', sizeof (ce_info
));
3057 ce_info
.test_bb
= test_bb
;
3058 ce_info
.then_bb
= then_edge
->dest
;
3059 ce_info
.else_bb
= else_edge
->dest
;
3060 ce_info
.pass
= pass
;
3062 #ifdef IFCVT_INIT_EXTRA_FIELDS
3063 IFCVT_INIT_EXTRA_FIELDS (&ce_info
);
3066 if (! reload_completed
3067 && noce_find_if_block (test_bb
, then_edge
, else_edge
, pass
))
3070 if (targetm
.have_conditional_execution () && reload_completed
3071 && cond_exec_find_if_block (&ce_info
))
3075 && optab_handler (ctrap_optab
, word_mode
)->insn_code
!= CODE_FOR_nothing
3076 && find_cond_trap (test_bb
, then_edge
, else_edge
))
3079 if (dom_info_state (CDI_POST_DOMINATORS
) >= DOM_NO_FAST_QUERY
3080 && (! targetm
.have_conditional_execution () || reload_completed
))
3082 if (find_if_case_1 (test_bb
, then_edge
, else_edge
))
3084 if (find_if_case_2 (test_bb
, then_edge
, else_edge
))
3092 fprintf (dump_file
, "Conversion succeeded on pass %d.\n", pass
);
3093 /* Set this so we continue looking. */
3094 cond_exec_changed_p
= TRUE
;
3095 return ce_info
.test_bb
;
3098 /* Return true if a block has two edges, one of which falls through to the next
3099 block, and the other jumps to a specific block, so that we can tell if the
3100 block is part of an && test or an || test. Returns either -1 or the number
3101 of non-note, non-jump, non-USE/CLOBBER insns in the block. */
3104 block_jumps_and_fallthru_p (basic_block cur_bb
, basic_block target_bb
)
3107 int fallthru_p
= FALSE
;
3114 if (!cur_bb
|| !target_bb
)
3117 /* If no edges, obviously it doesn't jump or fallthru. */
3118 if (EDGE_COUNT (cur_bb
->succs
) == 0)
3121 FOR_EACH_EDGE (cur_edge
, ei
, cur_bb
->succs
)
3123 if (cur_edge
->flags
& EDGE_COMPLEX
)
3124 /* Anything complex isn't what we want. */
3127 else if (cur_edge
->flags
& EDGE_FALLTHRU
)
3130 else if (cur_edge
->dest
== target_bb
)
3137 if ((jump_p
& fallthru_p
) == 0)
3140 /* Don't allow calls in the block, since this is used to group && and ||
3141 together for conditional execution support. ??? we should support
3142 conditional execution support across calls for IA-64 some day, but
3143 for now it makes the code simpler. */
3144 end
= BB_END (cur_bb
);
3145 insn
= BB_HEAD (cur_bb
);
3147 while (insn
!= NULL_RTX
)
3154 && !DEBUG_INSN_P (insn
)
3155 && GET_CODE (PATTERN (insn
)) != USE
3156 && GET_CODE (PATTERN (insn
)) != CLOBBER
)
3162 insn
= NEXT_INSN (insn
);
3168 /* Determine if a given basic block heads a simple IF-THEN or IF-THEN-ELSE
3169 block. If so, we'll try to convert the insns to not require the branch.
3170 Return TRUE if we were successful at converting the block. */
3173 cond_exec_find_if_block (struct ce_if_block
* ce_info
)
3175 basic_block test_bb
= ce_info
->test_bb
;
3176 basic_block then_bb
= ce_info
->then_bb
;
3177 basic_block else_bb
= ce_info
->else_bb
;
3178 basic_block join_bb
= NULL_BLOCK
;
3183 ce_info
->last_test_bb
= test_bb
;
3185 /* We only ever should get here after reload,
3186 and only if we have conditional execution. */
3187 gcc_assert (targetm
.have_conditional_execution () && reload_completed
);
3189 /* Discover if any fall through predecessors of the current test basic block
3190 were && tests (which jump to the else block) or || tests (which jump to
3192 if (single_pred_p (test_bb
)
3193 && single_pred_edge (test_bb
)->flags
== EDGE_FALLTHRU
)
3195 basic_block bb
= single_pred (test_bb
);
3196 basic_block target_bb
;
3197 int max_insns
= MAX_CONDITIONAL_EXECUTE
;
3200 /* Determine if the preceding block is an && or || block. */
3201 if ((n_insns
= block_jumps_and_fallthru_p (bb
, else_bb
)) >= 0)
3203 ce_info
->and_and_p
= TRUE
;
3204 target_bb
= else_bb
;
3206 else if ((n_insns
= block_jumps_and_fallthru_p (bb
, then_bb
)) >= 0)
3208 ce_info
->and_and_p
= FALSE
;
3209 target_bb
= then_bb
;
3212 target_bb
= NULL_BLOCK
;
3214 if (target_bb
&& n_insns
<= max_insns
)
3216 int total_insns
= 0;
3219 ce_info
->last_test_bb
= test_bb
;
3221 /* Found at least one && or || block, look for more. */
3224 ce_info
->test_bb
= test_bb
= bb
;
3225 total_insns
+= n_insns
;
3228 if (!single_pred_p (bb
))
3231 bb
= single_pred (bb
);
3232 n_insns
= block_jumps_and_fallthru_p (bb
, target_bb
);
3234 while (n_insns
>= 0 && (total_insns
+ n_insns
) <= max_insns
);
3236 ce_info
->num_multiple_test_blocks
= blocks
;
3237 ce_info
->num_multiple_test_insns
= total_insns
;
3239 if (ce_info
->and_and_p
)
3240 ce_info
->num_and_and_blocks
= blocks
;
3242 ce_info
->num_or_or_blocks
= blocks
;
3246 /* The THEN block of an IF-THEN combo must have exactly one predecessor,
3247 other than any || blocks which jump to the THEN block. */
3248 if ((EDGE_COUNT (then_bb
->preds
) - ce_info
->num_or_or_blocks
) != 1)
3251 /* The edges of the THEN and ELSE blocks cannot have complex edges. */
3252 FOR_EACH_EDGE (cur_edge
, ei
, then_bb
->preds
)
3254 if (cur_edge
->flags
& EDGE_COMPLEX
)
3258 FOR_EACH_EDGE (cur_edge
, ei
, else_bb
->preds
)
3260 if (cur_edge
->flags
& EDGE_COMPLEX
)
3264 /* The THEN block of an IF-THEN combo must have zero or one successors. */
3265 if (EDGE_COUNT (then_bb
->succs
) > 0
3266 && (!single_succ_p (then_bb
)
3267 || (single_succ_edge (then_bb
)->flags
& EDGE_COMPLEX
)
3268 || (epilogue_completed
&& tablejump_p (BB_END (then_bb
), NULL
, NULL
))))
3271 /* If the THEN block has no successors, conditional execution can still
3272 make a conditional call. Don't do this unless the ELSE block has
3273 only one incoming edge -- the CFG manipulation is too ugly otherwise.
3274 Check for the last insn of the THEN block being an indirect jump, which
3275 is listed as not having any successors, but confuses the rest of the CE
3276 code processing. ??? we should fix this in the future. */
3277 if (EDGE_COUNT (then_bb
->succs
) == 0)
3279 if (single_pred_p (else_bb
))
3281 rtx last_insn
= BB_END (then_bb
);
3284 && NOTE_P (last_insn
)
3285 && last_insn
!= BB_HEAD (then_bb
))
3286 last_insn
= PREV_INSN (last_insn
);
3289 && JUMP_P (last_insn
)
3290 && ! simplejump_p (last_insn
))
3294 else_bb
= NULL_BLOCK
;
3300 /* If the THEN block's successor is the other edge out of the TEST block,
3301 then we have an IF-THEN combo without an ELSE. */
3302 else if (single_succ (then_bb
) == else_bb
)
3305 else_bb
= NULL_BLOCK
;
3308 /* If the THEN and ELSE block meet in a subsequent block, and the ELSE
3309 has exactly one predecessor and one successor, and the outgoing edge
3310 is not complex, then we have an IF-THEN-ELSE combo. */
3311 else if (single_succ_p (else_bb
)
3312 && single_succ (then_bb
) == single_succ (else_bb
)
3313 && single_pred_p (else_bb
)
3314 && ! (single_succ_edge (else_bb
)->flags
& EDGE_COMPLEX
)
3315 && ! (epilogue_completed
&& tablejump_p (BB_END (else_bb
), NULL
, NULL
)))
3316 join_bb
= single_succ (else_bb
);
3318 /* Otherwise it is not an IF-THEN or IF-THEN-ELSE combination. */
3322 num_possible_if_blocks
++;
3327 "\nIF-THEN%s block found, pass %d, start block %d "
3328 "[insn %d], then %d [%d]",
3329 (else_bb
) ? "-ELSE" : "",
3332 BB_HEAD (test_bb
) ? (int)INSN_UID (BB_HEAD (test_bb
)) : -1,
3334 BB_HEAD (then_bb
) ? (int)INSN_UID (BB_HEAD (then_bb
)) : -1);
3337 fprintf (dump_file
, ", else %d [%d]",
3339 BB_HEAD (else_bb
) ? (int)INSN_UID (BB_HEAD (else_bb
)) : -1);
3341 fprintf (dump_file
, ", join %d [%d]",
3343 BB_HEAD (join_bb
) ? (int)INSN_UID (BB_HEAD (join_bb
)) : -1);
3345 if (ce_info
->num_multiple_test_blocks
> 0)
3346 fprintf (dump_file
, ", %d %s block%s last test %d [%d]",
3347 ce_info
->num_multiple_test_blocks
,
3348 (ce_info
->and_and_p
) ? "&&" : "||",
3349 (ce_info
->num_multiple_test_blocks
== 1) ? "" : "s",
3350 ce_info
->last_test_bb
->index
,
3351 ((BB_HEAD (ce_info
->last_test_bb
))
3352 ? (int)INSN_UID (BB_HEAD (ce_info
->last_test_bb
))
3355 fputc ('\n', dump_file
);
3358 /* Make sure IF, THEN, and ELSE, blocks are adjacent. Actually, we get the
3359 first condition for free, since we've already asserted that there's a
3360 fallthru edge from IF to THEN. Likewise for the && and || blocks, since
3361 we checked the FALLTHRU flag, those are already adjacent to the last IF
3363 /* ??? As an enhancement, move the ELSE block. Have to deal with
3364 BLOCK notes, if by no other means than backing out the merge if they
3365 exist. Sticky enough I don't want to think about it now. */
3367 if (else_bb
&& (next
= next
->next_bb
) != else_bb
)
3369 if ((next
= next
->next_bb
) != join_bb
&& join_bb
!= EXIT_BLOCK_PTR
)
3377 /* Do the real work. */
3379 ce_info
->else_bb
= else_bb
;
3380 ce_info
->join_bb
= join_bb
;
3382 /* If we have && and || tests, try to first handle combining the && and ||
3383 tests into the conditional code, and if that fails, go back and handle
3384 it without the && and ||, which at present handles the && case if there
3385 was no ELSE block. */
3386 if (cond_exec_process_if_block (ce_info
, TRUE
))
3389 if (ce_info
->num_multiple_test_blocks
)
3393 if (cond_exec_process_if_block (ce_info
, FALSE
))
3400 /* Convert a branch over a trap, or a branch
3401 to a trap, into a conditional trap. */
3404 find_cond_trap (basic_block test_bb
, edge then_edge
, edge else_edge
)
3406 basic_block then_bb
= then_edge
->dest
;
3407 basic_block else_bb
= else_edge
->dest
;
3408 basic_block other_bb
, trap_bb
;
3409 rtx trap
, jump
, cond
, cond_earliest
, seq
;
3412 /* Locate the block with the trap instruction. */
3413 /* ??? While we look for no successors, we really ought to allow
3414 EH successors. Need to fix merge_if_block for that to work. */
3415 if ((trap
= block_has_only_trap (then_bb
)) != NULL
)
3416 trap_bb
= then_bb
, other_bb
= else_bb
;
3417 else if ((trap
= block_has_only_trap (else_bb
)) != NULL
)
3418 trap_bb
= else_bb
, other_bb
= then_bb
;
3424 fprintf (dump_file
, "\nTRAP-IF block found, start %d, trap %d\n",
3425 test_bb
->index
, trap_bb
->index
);
3428 /* If this is not a standard conditional jump, we can't parse it. */
3429 jump
= BB_END (test_bb
);
3430 cond
= noce_get_condition (jump
, &cond_earliest
, false);
3434 /* If the conditional jump is more than just a conditional jump, then
3435 we can not do if-conversion on this block. */
3436 if (! onlyjump_p (jump
))
3439 /* We must be comparing objects whose modes imply the size. */
3440 if (GET_MODE (XEXP (cond
, 0)) == BLKmode
)
3443 /* Reverse the comparison code, if necessary. */
3444 code
= GET_CODE (cond
);
3445 if (then_bb
== trap_bb
)
3447 code
= reversed_comparison_code (cond
, jump
);
3448 if (code
== UNKNOWN
)
3452 /* Attempt to generate the conditional trap. */
3453 seq
= gen_cond_trap (code
, copy_rtx (XEXP (cond
, 0)),
3454 copy_rtx (XEXP (cond
, 1)),
3455 TRAP_CODE (PATTERN (trap
)));
3459 /* Emit the new insns before cond_earliest. */
3460 emit_insn_before_setloc (seq
, cond_earliest
, INSN_LOCATOR (trap
));
3462 /* Delete the trap block if possible. */
3463 remove_edge (trap_bb
== then_bb
? then_edge
: else_edge
);
3464 df_set_bb_dirty (test_bb
);
3465 df_set_bb_dirty (then_bb
);
3466 df_set_bb_dirty (else_bb
);
3468 if (EDGE_COUNT (trap_bb
->preds
) == 0)
3470 delete_basic_block (trap_bb
);
3474 /* Wire together the blocks again. */
3475 if (current_ir_type () == IR_RTL_CFGLAYOUT
)
3476 single_succ_edge (test_bb
)->flags
|= EDGE_FALLTHRU
;
3481 lab
= JUMP_LABEL (jump
);
3482 newjump
= emit_jump_insn_after (gen_jump (lab
), jump
);
3483 LABEL_NUSES (lab
) += 1;
3484 JUMP_LABEL (newjump
) = lab
;
3485 emit_barrier_after (newjump
);
3489 if (can_merge_blocks_p (test_bb
, other_bb
))
3491 merge_blocks (test_bb
, other_bb
);
3495 num_updated_if_blocks
++;
3499 /* Subroutine of find_cond_trap: if BB contains only a trap insn,
3503 block_has_only_trap (basic_block bb
)
3507 /* We're not the exit block. */
3508 if (bb
== EXIT_BLOCK_PTR
)
3511 /* The block must have no successors. */
3512 if (EDGE_COUNT (bb
->succs
) > 0)
3515 /* The only instruction in the THEN block must be the trap. */
3516 trap
= first_active_insn (bb
);
3517 if (! (trap
== BB_END (bb
)
3518 && GET_CODE (PATTERN (trap
)) == TRAP_IF
3519 && TRAP_CONDITION (PATTERN (trap
)) == const_true_rtx
))
3525 /* Look for IF-THEN-ELSE cases in which one of THEN or ELSE is
3526 transformable, but not necessarily the other. There need be no
3529 Return TRUE if we were successful at converting the block.
3531 Cases we'd like to look at:
3534 if (test) goto over; // x not live
3542 if (! test) goto label;
3545 if (test) goto E; // x not live
3559 (3) // This one's really only interesting for targets that can do
3560 // multiway branching, e.g. IA-64 BBB bundles. For other targets
3561 // it results in multiple branches on a cache line, which often
3562 // does not sit well with predictors.
3564 if (test1) goto E; // predicted not taken
3580 (A) Don't do (2) if the branch is predicted against the block we're
3581 eliminating. Do it anyway if we can eliminate a branch; this requires
3582 that the sole successor of the eliminated block postdominate the other
3585 (B) With CE, on (3) we can steal from both sides of the if, creating
3594 Again, this is most useful if J postdominates.
3596 (C) CE substitutes for helpful life information.
3598 (D) These heuristics need a lot of work. */
3600 /* Tests for case 1 above. */
3603 find_if_case_1 (basic_block test_bb
, edge then_edge
, edge else_edge
)
3605 basic_block then_bb
= then_edge
->dest
;
3606 basic_block else_bb
= else_edge
->dest
;
3610 /* If we are partitioning hot/cold basic blocks, we don't want to
3611 mess up unconditional or indirect jumps that cross between hot
3614 Basic block partitioning may result in some jumps that appear to
3615 be optimizable (or blocks that appear to be mergeable), but which really
3616 must be left untouched (they are required to make it safely across
3617 partition boundaries). See the comments at the top of
3618 bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */
3620 if ((BB_END (then_bb
)
3621 && find_reg_note (BB_END (then_bb
), REG_CROSSING_JUMP
, NULL_RTX
))
3622 || (BB_END (test_bb
)
3623 && find_reg_note (BB_END (test_bb
), REG_CROSSING_JUMP
, NULL_RTX
))
3624 || (BB_END (else_bb
)
3625 && find_reg_note (BB_END (else_bb
), REG_CROSSING_JUMP
,
3629 /* THEN has one successor. */
3630 if (!single_succ_p (then_bb
))
3633 /* THEN does not fall through, but is not strange either. */
3634 if (single_succ_edge (then_bb
)->flags
& (EDGE_COMPLEX
| EDGE_FALLTHRU
))
3637 /* THEN has one predecessor. */
3638 if (!single_pred_p (then_bb
))
3641 /* THEN must do something. */
3642 if (forwarder_block_p (then_bb
))
3645 num_possible_if_blocks
++;
3648 "\nIF-CASE-1 found, start %d, then %d\n",
3649 test_bb
->index
, then_bb
->index
);
3651 /* THEN is small. */
3652 if (! cheap_bb_rtx_cost_p (then_bb
,
3653 COSTS_N_INSNS (BRANCH_COST (optimize_bb_for_speed_p (then_edge
->src
),
3654 predictable_edge_p (then_edge
)))))
3657 /* Registers set are dead, or are predicable. */
3658 if (! dead_or_predicable (test_bb
, then_bb
, else_bb
,
3659 single_succ (then_bb
), 1))
3662 /* Conversion went ok, including moving the insns and fixing up the
3663 jump. Adjust the CFG to match. */
3665 /* We can avoid creating a new basic block if then_bb is immediately
3666 followed by else_bb, i.e. deleting then_bb allows test_bb to fall
3669 if (then_bb
->next_bb
== else_bb
3670 && then_bb
->prev_bb
== test_bb
3671 && else_bb
!= EXIT_BLOCK_PTR
)
3673 redirect_edge_succ (FALLTHRU_EDGE (test_bb
), else_bb
);
3677 new_bb
= redirect_edge_and_branch_force (FALLTHRU_EDGE (test_bb
),
3680 df_set_bb_dirty (test_bb
);
3681 df_set_bb_dirty (else_bb
);
3683 then_bb_index
= then_bb
->index
;
3684 delete_basic_block (then_bb
);
3686 /* Make rest of code believe that the newly created block is the THEN_BB
3687 block we removed. */
3690 df_bb_replace (then_bb_index
, new_bb
);
3691 /* Since the fallthru edge was redirected from test_bb to new_bb,
3692 we need to ensure that new_bb is in the same partition as
3693 test bb (you can not fall through across section boundaries). */
3694 BB_COPY_PARTITION (new_bb
, test_bb
);
3698 num_updated_if_blocks
++;
3703 /* Test for case 2 above. */
3706 find_if_case_2 (basic_block test_bb
, edge then_edge
, edge else_edge
)
3708 basic_block then_bb
= then_edge
->dest
;
3709 basic_block else_bb
= else_edge
->dest
;
3713 /* If we are partitioning hot/cold basic blocks, we don't want to
3714 mess up unconditional or indirect jumps that cross between hot
3717 Basic block partitioning may result in some jumps that appear to
3718 be optimizable (or blocks that appear to be mergeable), but which really
3719 must be left untouched (they are required to make it safely across
3720 partition boundaries). See the comments at the top of
3721 bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */
3723 if ((BB_END (then_bb
)
3724 && find_reg_note (BB_END (then_bb
), REG_CROSSING_JUMP
, NULL_RTX
))
3725 || (BB_END (test_bb
)
3726 && find_reg_note (BB_END (test_bb
), REG_CROSSING_JUMP
, NULL_RTX
))
3727 || (BB_END (else_bb
)
3728 && find_reg_note (BB_END (else_bb
), REG_CROSSING_JUMP
,
3732 /* ELSE has one successor. */
3733 if (!single_succ_p (else_bb
))
3736 else_succ
= single_succ_edge (else_bb
);
3738 /* ELSE outgoing edge is not complex. */
3739 if (else_succ
->flags
& EDGE_COMPLEX
)
3742 /* ELSE has one predecessor. */
3743 if (!single_pred_p (else_bb
))
3746 /* THEN is not EXIT. */
3747 if (then_bb
->index
< NUM_FIXED_BLOCKS
)
3750 /* ELSE is predicted or SUCC(ELSE) postdominates THEN. */
3751 note
= find_reg_note (BB_END (test_bb
), REG_BR_PROB
, NULL_RTX
);
3752 if (note
&& INTVAL (XEXP (note
, 0)) >= REG_BR_PROB_BASE
/ 2)
3754 else if (else_succ
->dest
->index
< NUM_FIXED_BLOCKS
3755 || dominated_by_p (CDI_POST_DOMINATORS
, then_bb
,
3761 num_possible_if_blocks
++;
3764 "\nIF-CASE-2 found, start %d, else %d\n",
3765 test_bb
->index
, else_bb
->index
);
3767 /* ELSE is small. */
3768 if (! cheap_bb_rtx_cost_p (else_bb
,
3769 COSTS_N_INSNS (BRANCH_COST (optimize_bb_for_speed_p (else_edge
->src
),
3770 predictable_edge_p (else_edge
)))))
3773 /* Registers set are dead, or are predicable. */
3774 if (! dead_or_predicable (test_bb
, else_bb
, then_bb
, else_succ
->dest
, 0))
3777 /* Conversion went ok, including moving the insns and fixing up the
3778 jump. Adjust the CFG to match. */
3780 df_set_bb_dirty (test_bb
);
3781 df_set_bb_dirty (then_bb
);
3782 delete_basic_block (else_bb
);
3785 num_updated_if_blocks
++;
3787 /* ??? We may now fallthru from one of THEN's successors into a join
3788 block. Rerun cleanup_cfg? Examine things manually? Wait? */
3793 /* A subroutine of dead_or_predicable called through for_each_rtx.
3794 Return 1 if a memory is found. */
3797 find_memory (rtx
*px
, void *data ATTRIBUTE_UNUSED
)
3802 /* Used by the code above to perform the actual rtl transformations.
3803 Return TRUE if successful.
3805 TEST_BB is the block containing the conditional branch. MERGE_BB
3806 is the block containing the code to manipulate. NEW_DEST is the
3807 label TEST_BB should be branching to after the conversion.
3808 REVERSEP is true if the sense of the branch should be reversed. */
3811 dead_or_predicable (basic_block test_bb
, basic_block merge_bb
,
3812 basic_block other_bb
, basic_block new_dest
, int reversep
)
3814 rtx head
, end
, jump
, earliest
= NULL_RTX
, old_dest
, new_label
= NULL_RTX
;
3815 /* Number of pending changes. */
3816 int n_validated_changes
= 0;
3818 jump
= BB_END (test_bb
);
3820 /* Find the extent of the real code in the merge block. */
3821 head
= BB_HEAD (merge_bb
);
3822 end
= BB_END (merge_bb
);
3824 while (DEBUG_INSN_P (end
) && end
!= head
)
3825 end
= PREV_INSN (end
);
3827 /* If merge_bb ends with a tablejump, predicating/moving insn's
3828 into test_bb and then deleting merge_bb will result in the jumptable
3829 that follows merge_bb being removed along with merge_bb and then we
3830 get an unresolved reference to the jumptable. */
3831 if (tablejump_p (end
, NULL
, NULL
))
3835 head
= NEXT_INSN (head
);
3836 while (DEBUG_INSN_P (head
) && head
!= end
)
3837 head
= NEXT_INSN (head
);
3842 head
= end
= NULL_RTX
;
3845 head
= NEXT_INSN (head
);
3846 while (DEBUG_INSN_P (head
) && head
!= end
)
3847 head
= NEXT_INSN (head
);
3854 head
= end
= NULL_RTX
;
3857 end
= PREV_INSN (end
);
3858 while (DEBUG_INSN_P (end
) && end
!= head
)
3859 end
= PREV_INSN (end
);
3862 /* Disable handling dead code by conditional execution if the machine needs
3863 to do anything funny with the tests, etc. */
3864 #ifndef IFCVT_MODIFY_TESTS
3865 if (targetm
.have_conditional_execution ())
3867 /* In the conditional execution case, we have things easy. We know
3868 the condition is reversible. We don't have to check life info
3869 because we're going to conditionally execute the code anyway.
3870 All that's left is making sure the insns involved can actually
3875 cond
= cond_exec_get_condition (jump
);
3879 prob_val
= find_reg_note (jump
, REG_BR_PROB
, NULL_RTX
);
3881 prob_val
= XEXP (prob_val
, 0);
3885 enum rtx_code rev
= reversed_comparison_code (cond
, jump
);
3888 cond
= gen_rtx_fmt_ee (rev
, GET_MODE (cond
), XEXP (cond
, 0),
3891 prob_val
= GEN_INT (REG_BR_PROB_BASE
- INTVAL (prob_val
));
3894 if (cond_exec_process_insns (NULL
, head
, end
, cond
, prob_val
, 0)
3895 && verify_changes (0))
3896 n_validated_changes
= num_validated_changes ();
3903 /* Try the NCE path if the CE path did not result in any changes. */
3904 if (n_validated_changes
== 0)
3906 /* In the non-conditional execution case, we have to verify that there
3907 are no trapping operations, no calls, no references to memory, and
3908 that any registers modified are dead at the branch site. */
3910 rtx insn
, cond
, prev
;
3911 bitmap merge_set
, test_live
, test_set
;
3912 unsigned i
, fail
= 0;
3915 /* Check for no calls or trapping operations. */
3916 for (insn
= head
; ; insn
= NEXT_INSN (insn
))
3920 if (NONDEBUG_INSN_P (insn
))
3922 if (may_trap_p (PATTERN (insn
)))
3925 /* ??? Even non-trapping memories such as stack frame
3926 references must be avoided. For stores, we collect
3927 no lifetime info; for reads, we'd have to assert
3928 true_dependence false against every store in the
3930 if (for_each_rtx (&PATTERN (insn
), find_memory
, NULL
))
3937 if (! any_condjump_p (jump
))
3940 /* Find the extent of the conditional. */
3941 cond
= noce_get_condition (jump
, &earliest
, false);
3946 MERGE_SET = set of registers set in MERGE_BB
3947 TEST_LIVE = set of registers live at EARLIEST
3948 TEST_SET = set of registers set between EARLIEST and the
3949 end of the block. */
3951 merge_set
= BITMAP_ALLOC (®_obstack
);
3952 test_live
= BITMAP_ALLOC (®_obstack
);
3953 test_set
= BITMAP_ALLOC (®_obstack
);
3955 /* ??? bb->local_set is only valid during calculate_global_regs_live,
3956 so we must recompute usage for MERGE_BB. Not so bad, I suppose,
3957 since we've already asserted that MERGE_BB is small. */
3958 /* If we allocated new pseudos (e.g. in the conditional move
3959 expander called from noce_emit_cmove), we must resize the
3961 if (max_regno
< max_reg_num ())
3962 max_regno
= max_reg_num ();
3964 FOR_BB_INSNS (merge_bb
, insn
)
3966 if (NONDEBUG_INSN_P (insn
))
3968 unsigned int uid
= INSN_UID (insn
);
3970 for (def_rec
= DF_INSN_UID_DEFS (uid
); *def_rec
; def_rec
++)
3972 df_ref def
= *def_rec
;
3973 bitmap_set_bit (merge_set
, DF_REF_REGNO (def
));
3978 /* For small register class machines, don't lengthen lifetimes of
3979 hard registers before reload. */
3980 if (SMALL_REGISTER_CLASSES
&& ! reload_completed
)
3982 EXECUTE_IF_SET_IN_BITMAP (merge_set
, 0, i
, bi
)
3984 if (i
< FIRST_PSEUDO_REGISTER
3986 && ! global_regs
[i
])
3991 /* For TEST, we're interested in a range of insns, not a whole block.
3992 Moreover, we're interested in the insns live from OTHER_BB. */
3994 /* The loop below takes the set of live registers
3995 after JUMP, and calculates the live set before EARLIEST. */
3996 bitmap_copy (test_live
, df_get_live_in (other_bb
));
3997 df_simulate_initialize_backwards (test_bb
, test_live
);
3998 for (insn
= jump
; ; insn
= prev
)
4002 df_simulate_find_defs (insn
, test_set
);
4003 df_simulate_one_insn_backwards (test_bb
, insn
, test_live
);
4005 prev
= PREV_INSN (insn
);
4006 if (insn
== earliest
)
4010 /* We can perform the transformation if
4011 MERGE_SET & (TEST_SET | TEST_LIVE)
4013 TEST_SET & DF_LIVE_IN (merge_bb)
4016 if (bitmap_intersect_p (test_set
, merge_set
)
4017 || bitmap_intersect_p (test_live
, merge_set
)
4018 || bitmap_intersect_p (test_set
, df_get_live_in (merge_bb
)))
4021 BITMAP_FREE (merge_set
);
4022 BITMAP_FREE (test_live
);
4023 BITMAP_FREE (test_set
);
4030 /* We don't want to use normal invert_jump or redirect_jump because
4031 we don't want to delete_insn called. Also, we want to do our own
4032 change group management. */
4034 old_dest
= JUMP_LABEL (jump
);
4035 if (other_bb
!= new_dest
)
4037 new_label
= block_label (new_dest
);
4039 ? ! invert_jump_1 (jump
, new_label
)
4040 : ! redirect_jump_1 (jump
, new_label
))
4044 if (verify_changes (n_validated_changes
))
4045 confirm_change_group ();
4049 if (other_bb
!= new_dest
)
4051 redirect_jump_2 (jump
, old_dest
, new_label
, 0, reversep
);
4053 redirect_edge_succ (BRANCH_EDGE (test_bb
), new_dest
);
4056 gcov_type count
, probability
;
4057 count
= BRANCH_EDGE (test_bb
)->count
;
4058 BRANCH_EDGE (test_bb
)->count
= FALLTHRU_EDGE (test_bb
)->count
;
4059 FALLTHRU_EDGE (test_bb
)->count
= count
;
4060 probability
= BRANCH_EDGE (test_bb
)->probability
;
4061 BRANCH_EDGE (test_bb
)->probability
4062 = FALLTHRU_EDGE (test_bb
)->probability
;
4063 FALLTHRU_EDGE (test_bb
)->probability
= probability
;
4064 update_br_prob_note (test_bb
);
4068 /* Move the insns out of MERGE_BB to before the branch. */
4073 if (end
== BB_END (merge_bb
))
4074 BB_END (merge_bb
) = PREV_INSN (head
);
4076 /* PR 21767: When moving insns above a conditional branch, REG_EQUAL
4077 notes might become invalid. */
4083 if (! INSN_P (insn
))
4085 note
= find_reg_note (insn
, REG_EQUAL
, NULL_RTX
);
4088 set
= single_set (insn
);
4089 if (!set
|| !function_invariant_p (SET_SRC (set
)))
4090 remove_note (insn
, note
);
4091 } while (insn
!= end
&& (insn
= NEXT_INSN (insn
)));
4093 reorder_insns (head
, end
, PREV_INSN (earliest
));
4096 /* Remove the jump and edge if we can. */
4097 if (other_bb
== new_dest
)
4100 remove_edge (BRANCH_EDGE (test_bb
));
4101 /* ??? Can't merge blocks here, as then_bb is still in use.
4102 At minimum, the merge will get done just before bb-reorder. */
4112 /* Main entry point for all if-conversion. */
4122 df_live_add_problem ();
4123 df_live_set_all_dirty ();
4126 num_possible_if_blocks
= 0;
4127 num_updated_if_blocks
= 0;
4128 num_true_changes
= 0;
4130 loop_optimizer_init (AVOID_CFG_MODIFICATIONS
);
4131 mark_loop_exit_edges ();
4132 loop_optimizer_finalize ();
4133 free_dominance_info (CDI_DOMINATORS
);
4135 /* Compute postdominators. */
4136 calculate_dominance_info (CDI_POST_DOMINATORS
);
4138 df_set_flags (DF_LR_RUN_DCE
);
4140 /* Go through each of the basic blocks looking for things to convert. If we
4141 have conditional execution, we make multiple passes to allow us to handle
4142 IF-THEN{-ELSE} blocks within other IF-THEN{-ELSE} blocks. */
4147 /* Only need to do dce on the first pass. */
4148 df_clear_flags (DF_LR_RUN_DCE
);
4149 cond_exec_changed_p
= FALSE
;
4152 #ifdef IFCVT_MULTIPLE_DUMPS
4153 if (dump_file
&& pass
> 1)
4154 fprintf (dump_file
, "\n\n========== Pass %d ==========\n", pass
);
4160 while (!df_get_bb_dirty (bb
)
4161 && (new_bb
= find_if_header (bb
, pass
)) != NULL
)
4165 #ifdef IFCVT_MULTIPLE_DUMPS
4166 if (dump_file
&& cond_exec_changed_p
)
4167 print_rtl_with_bb (dump_file
, get_insns ());
4170 while (cond_exec_changed_p
);
4172 #ifdef IFCVT_MULTIPLE_DUMPS
4174 fprintf (dump_file
, "\n\n========== no more changes\n");
4177 free_dominance_info (CDI_POST_DOMINATORS
);
4182 clear_aux_for_blocks ();
4184 /* If we allocated new pseudos, we must resize the array for sched1. */
4185 if (max_regno
< max_reg_num ())
4186 max_regno
= max_reg_num ();
4188 /* Write the final stats. */
4189 if (dump_file
&& num_possible_if_blocks
> 0)
4192 "\n%d possible IF blocks searched.\n",
4193 num_possible_if_blocks
);
4195 "%d IF blocks converted.\n",
4196 num_updated_if_blocks
);
4198 "%d true changes made.\n\n\n",
4203 df_remove_problem (df_live
);
4205 #ifdef ENABLE_CHECKING
4206 verify_flow_info ();
4211 gate_handle_if_conversion (void)
4213 return (optimize
> 0)
4214 && dbg_cnt (if_conversion
);
4217 /* If-conversion and CFG cleanup. */
4219 rest_of_handle_if_conversion (void)
4221 if (flag_if_conversion
)
4224 dump_flow_info (dump_file
, dump_flags
);
4225 cleanup_cfg (CLEANUP_EXPENSIVE
);
4233 struct rtl_opt_pass pass_rtl_ifcvt
=
4238 gate_handle_if_conversion
, /* gate */
4239 rest_of_handle_if_conversion
, /* execute */
4242 0, /* static_pass_number */
4243 TV_IFCVT
, /* tv_id */
4244 0, /* properties_required */
4245 0, /* properties_provided */
4246 0, /* properties_destroyed */
4247 0, /* todo_flags_start */
4248 TODO_df_finish
| TODO_verify_rtl_sharing
|
4249 TODO_dump_func
/* todo_flags_finish */
4254 gate_handle_if_after_combine (void)
4256 return optimize
> 0 && flag_if_conversion
4257 && dbg_cnt (if_after_combine
);
4261 /* Rerun if-conversion, as combine may have simplified things enough
4262 to now meet sequence length restrictions. */
4264 rest_of_handle_if_after_combine (void)
4270 struct rtl_opt_pass pass_if_after_combine
=
4275 gate_handle_if_after_combine
, /* gate */
4276 rest_of_handle_if_after_combine
, /* execute */
4279 0, /* static_pass_number */
4280 TV_IFCVT
, /* tv_id */
4281 0, /* properties_required */
4282 0, /* properties_provided */
4283 0, /* properties_destroyed */
4284 0, /* todo_flags_start */
4285 TODO_df_finish
| TODO_verify_rtl_sharing
|
4287 TODO_ggc_collect
/* todo_flags_finish */
4293 gate_handle_if_after_reload (void)
4295 return optimize
> 0 && flag_if_conversion2
4296 && dbg_cnt (if_after_reload
);
4300 rest_of_handle_if_after_reload (void)
4307 struct rtl_opt_pass pass_if_after_reload
=
4312 gate_handle_if_after_reload
, /* gate */
4313 rest_of_handle_if_after_reload
, /* execute */
4316 0, /* static_pass_number */
4317 TV_IFCVT2
, /* tv_id */
4318 0, /* properties_required */
4319 0, /* properties_provided */
4320 0, /* properties_destroyed */
4321 0, /* todo_flags_start */
4322 TODO_df_finish
| TODO_verify_rtl_sharing
|
4324 TODO_ggc_collect
/* todo_flags_finish */