1 /* If-conversion support.
2 Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005
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 2, 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 COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
24 #include "coretypes.h"
31 #include "insn-config.h"
34 #include "hard-reg-set.h"
35 #include "basic-block.h"
46 #ifndef HAVE_conditional_execution
47 #define HAVE_conditional_execution 0
49 #ifndef HAVE_conditional_move
50 #define HAVE_conditional_move 0
61 #ifndef HAVE_conditional_trap
62 #define HAVE_conditional_trap 0
65 #ifndef MAX_CONDITIONAL_EXECUTE
66 #define MAX_CONDITIONAL_EXECUTE (BRANCH_COST + 1)
69 #define NULL_EDGE ((edge) NULL)
70 #define NULL_BLOCK ((basic_block) NULL)
72 /* # of IF-THEN or IF-THEN-ELSE blocks we looked at */
73 static int num_possible_if_blocks
;
75 /* # of IF-THEN or IF-THEN-ELSE blocks were converted to conditional
77 static int num_updated_if_blocks
;
79 /* # of changes made which require life information to be updated. */
80 static int num_true_changes
;
82 /* Whether conditional execution changes were made. */
83 static int cond_exec_changed_p
;
85 /* True if life data ok at present. */
86 static bool life_data_ok
;
88 /* Forward references. */
89 static int count_bb_insns (basic_block
);
90 static bool cheap_bb_rtx_cost_p (basic_block
, int);
91 static rtx
first_active_insn (basic_block
);
92 static rtx
last_active_insn (basic_block
, int);
93 static basic_block
block_fallthru (basic_block
);
94 static int cond_exec_process_insns (ce_if_block_t
*, rtx
, rtx
, rtx
, rtx
, int);
95 static rtx
cond_exec_get_condition (rtx
);
96 static int cond_exec_process_if_block (ce_if_block_t
*, int);
97 static rtx
noce_get_condition (rtx
, rtx
*);
98 static int noce_operand_ok (rtx
);
99 static int noce_process_if_block (ce_if_block_t
*);
100 static int process_if_block (ce_if_block_t
*);
101 static void merge_if_block (ce_if_block_t
*);
102 static int find_cond_trap (basic_block
, edge
, edge
);
103 static basic_block
find_if_header (basic_block
, int);
104 static int block_jumps_and_fallthru_p (basic_block
, basic_block
);
105 static int find_if_block (ce_if_block_t
*);
106 static int find_if_case_1 (basic_block
, edge
, edge
);
107 static int find_if_case_2 (basic_block
, edge
, edge
);
108 static int find_memory (rtx
*, void *);
109 static int dead_or_predicable (basic_block
, basic_block
, basic_block
,
111 static void noce_emit_move_insn (rtx
, rtx
);
112 static rtx
block_has_only_trap (basic_block
);
113 static void mark_loop_exit_edges (void);
115 /* Sets EDGE_LOOP_EXIT flag for all loop exits. */
117 mark_loop_exit_edges (void)
123 flow_loops_find (&loops
, LOOP_TREE
);
124 free_dominance_info (CDI_DOMINATORS
);
131 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
133 if (find_common_loop (bb
->loop_father
, e
->dest
->loop_father
)
135 e
->flags
|= EDGE_LOOP_EXIT
;
137 e
->flags
&= ~EDGE_LOOP_EXIT
;
142 flow_loops_free (&loops
);
145 /* Count the number of non-jump active insns in BB. */
148 count_bb_insns (basic_block bb
)
151 rtx insn
= BB_HEAD (bb
);
155 if (CALL_P (insn
) || NONJUMP_INSN_P (insn
))
158 if (insn
== BB_END (bb
))
160 insn
= NEXT_INSN (insn
);
166 /* Determine whether the total insn_rtx_cost on non-jump insns in
167 basic block BB is less than MAX_COST. This function returns
168 false if the cost of any instruction could not be estimated. */
171 cheap_bb_rtx_cost_p (basic_block bb
, int max_cost
)
174 rtx insn
= BB_HEAD (bb
);
178 if (NONJUMP_INSN_P (insn
))
180 int cost
= insn_rtx_cost (PATTERN (insn
));
184 /* If this instruction is the load or set of a "stack" register,
185 such as a floating point register on x87, then the cost of
186 speculatively executing this instruction needs to include
187 the additional cost of popping this register off of the
191 rtx set
= single_set (insn
);
192 if (set
&& STACK_REG_P (SET_DEST (set
)))
193 cost
+= COSTS_N_INSNS (1);
198 if (count
>= max_cost
)
201 else if (CALL_P (insn
))
204 if (insn
== BB_END (bb
))
206 insn
= NEXT_INSN (insn
);
212 /* Return the first non-jump active insn in the basic block. */
215 first_active_insn (basic_block bb
)
217 rtx insn
= BB_HEAD (bb
);
221 if (insn
== BB_END (bb
))
223 insn
= NEXT_INSN (insn
);
226 while (NOTE_P (insn
))
228 if (insn
== BB_END (bb
))
230 insn
= NEXT_INSN (insn
);
239 /* Return the last non-jump active (non-jump) insn in the basic block. */
242 last_active_insn (basic_block bb
, int skip_use_p
)
244 rtx insn
= BB_END (bb
);
245 rtx head
= BB_HEAD (bb
);
250 && NONJUMP_INSN_P (insn
)
251 && GET_CODE (PATTERN (insn
)) == USE
))
255 insn
= PREV_INSN (insn
);
264 /* Return the basic block reached by falling though the basic block BB. */
267 block_fallthru (basic_block bb
)
272 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
273 if (e
->flags
& EDGE_FALLTHRU
)
276 return (e
) ? e
->dest
: NULL_BLOCK
;
279 /* Go through a bunch of insns, converting them to conditional
280 execution format if possible. Return TRUE if all of the non-note
281 insns were processed. */
284 cond_exec_process_insns (ce_if_block_t
*ce_info ATTRIBUTE_UNUSED
,
285 /* if block information */rtx start
,
286 /* first insn to look at */rtx end
,
287 /* last insn to look at */rtx test
,
288 /* conditional execution test */rtx prob_val
,
289 /* probability of branch taken. */int mod_ok
)
291 int must_be_last
= FALSE
;
299 for (insn
= start
; ; insn
= NEXT_INSN (insn
))
304 if (!NONJUMP_INSN_P (insn
) && !CALL_P (insn
))
307 /* Remove USE insns that get in the way. */
308 if (reload_completed
&& GET_CODE (PATTERN (insn
)) == USE
)
310 /* ??? Ug. Actually unlinking the thing is problematic,
311 given what we'd have to coordinate with our callers. */
312 SET_INSN_DELETED (insn
);
316 /* Last insn wasn't last? */
320 if (modified_in_p (test
, insn
))
327 /* Now build the conditional form of the instruction. */
328 pattern
= PATTERN (insn
);
329 xtest
= copy_rtx (test
);
331 /* If this is already a COND_EXEC, rewrite the test to be an AND of the
333 if (GET_CODE (pattern
) == COND_EXEC
)
335 if (GET_MODE (xtest
) != GET_MODE (COND_EXEC_TEST (pattern
)))
338 xtest
= gen_rtx_AND (GET_MODE (xtest
), xtest
,
339 COND_EXEC_TEST (pattern
));
340 pattern
= COND_EXEC_CODE (pattern
);
343 pattern
= gen_rtx_COND_EXEC (VOIDmode
, xtest
, pattern
);
345 /* If the machine needs to modify the insn being conditionally executed,
346 say for example to force a constant integer operand into a temp
347 register, do so here. */
348 #ifdef IFCVT_MODIFY_INSN
349 IFCVT_MODIFY_INSN (ce_info
, pattern
, insn
);
354 validate_change (insn
, &PATTERN (insn
), pattern
, 1);
356 if (CALL_P (insn
) && prob_val
)
357 validate_change (insn
, ®_NOTES (insn
),
358 alloc_EXPR_LIST (REG_BR_PROB
, prob_val
,
359 REG_NOTES (insn
)), 1);
369 /* Return the condition for a jump. Do not do any special processing. */
372 cond_exec_get_condition (rtx jump
)
376 if (any_condjump_p (jump
))
377 test_if
= SET_SRC (pc_set (jump
));
380 cond
= XEXP (test_if
, 0);
382 /* If this branches to JUMP_LABEL when the condition is false,
383 reverse the condition. */
384 if (GET_CODE (XEXP (test_if
, 2)) == LABEL_REF
385 && XEXP (XEXP (test_if
, 2), 0) == JUMP_LABEL (jump
))
387 enum rtx_code rev
= reversed_comparison_code (cond
, jump
);
391 cond
= gen_rtx_fmt_ee (rev
, GET_MODE (cond
), XEXP (cond
, 0),
398 /* Given a simple IF-THEN or IF-THEN-ELSE block, attempt to convert it
399 to conditional execution. Return TRUE if we were successful at
400 converting the block. */
403 cond_exec_process_if_block (ce_if_block_t
* ce_info
,
404 /* if block information */int do_multiple_p
)
406 basic_block test_bb
= ce_info
->test_bb
; /* last test block */
407 basic_block then_bb
= ce_info
->then_bb
; /* THEN */
408 basic_block else_bb
= ce_info
->else_bb
; /* ELSE or NULL */
409 rtx test_expr
; /* expression in IF_THEN_ELSE that is tested */
410 rtx then_start
; /* first insn in THEN block */
411 rtx then_end
; /* last insn + 1 in THEN block */
412 rtx else_start
= NULL_RTX
; /* first insn in ELSE block or NULL */
413 rtx else_end
= NULL_RTX
; /* last insn + 1 in ELSE block */
414 int max
; /* max # of insns to convert. */
415 int then_mod_ok
; /* whether conditional mods are ok in THEN */
416 rtx true_expr
; /* test for else block insns */
417 rtx false_expr
; /* test for then block insns */
418 rtx true_prob_val
; /* probability of else block */
419 rtx false_prob_val
; /* probability of then block */
421 enum rtx_code false_code
;
423 /* If test is comprised of && or || elements, and we've failed at handling
424 all of them together, just use the last test if it is the special case of
425 && elements without an ELSE block. */
426 if (!do_multiple_p
&& ce_info
->num_multiple_test_blocks
)
428 if (else_bb
|| ! ce_info
->and_and_p
)
431 ce_info
->test_bb
= test_bb
= ce_info
->last_test_bb
;
432 ce_info
->num_multiple_test_blocks
= 0;
433 ce_info
->num_and_and_blocks
= 0;
434 ce_info
->num_or_or_blocks
= 0;
437 /* Find the conditional jump to the ELSE or JOIN part, and isolate
439 test_expr
= cond_exec_get_condition (BB_END (test_bb
));
443 /* If the conditional jump is more than just a conditional jump,
444 then we can not do conditional execution conversion on this block. */
445 if (! onlyjump_p (BB_END (test_bb
)))
448 /* Collect the bounds of where we're to search, skipping any labels, jumps
449 and notes at the beginning and end of the block. Then count the total
450 number of insns and see if it is small enough to convert. */
451 then_start
= first_active_insn (then_bb
);
452 then_end
= last_active_insn (then_bb
, TRUE
);
453 n_insns
= ce_info
->num_then_insns
= count_bb_insns (then_bb
);
454 max
= MAX_CONDITIONAL_EXECUTE
;
459 else_start
= first_active_insn (else_bb
);
460 else_end
= last_active_insn (else_bb
, TRUE
);
461 n_insns
+= ce_info
->num_else_insns
= count_bb_insns (else_bb
);
467 /* Map test_expr/test_jump into the appropriate MD tests to use on
468 the conditionally executed code. */
470 true_expr
= test_expr
;
472 false_code
= reversed_comparison_code (true_expr
, BB_END (test_bb
));
473 if (false_code
!= UNKNOWN
)
474 false_expr
= gen_rtx_fmt_ee (false_code
, GET_MODE (true_expr
),
475 XEXP (true_expr
, 0), XEXP (true_expr
, 1));
477 false_expr
= NULL_RTX
;
479 #ifdef IFCVT_MODIFY_TESTS
480 /* If the machine description needs to modify the tests, such as setting a
481 conditional execution register from a comparison, it can do so here. */
482 IFCVT_MODIFY_TESTS (ce_info
, true_expr
, false_expr
);
484 /* See if the conversion failed. */
485 if (!true_expr
|| !false_expr
)
489 true_prob_val
= find_reg_note (BB_END (test_bb
), REG_BR_PROB
, NULL_RTX
);
492 true_prob_val
= XEXP (true_prob_val
, 0);
493 false_prob_val
= GEN_INT (REG_BR_PROB_BASE
- INTVAL (true_prob_val
));
496 false_prob_val
= NULL_RTX
;
498 /* If we have && or || tests, do them here. These tests are in the adjacent
499 blocks after the first block containing the test. */
500 if (ce_info
->num_multiple_test_blocks
> 0)
502 basic_block bb
= test_bb
;
503 basic_block last_test_bb
= ce_info
->last_test_bb
;
512 enum rtx_code f_code
;
514 bb
= block_fallthru (bb
);
515 start
= first_active_insn (bb
);
516 end
= last_active_insn (bb
, TRUE
);
518 && ! cond_exec_process_insns (ce_info
, start
, end
, false_expr
,
519 false_prob_val
, FALSE
))
522 /* If the conditional jump is more than just a conditional jump, then
523 we can not do conditional execution conversion on this block. */
524 if (! onlyjump_p (BB_END (bb
)))
527 /* Find the conditional jump and isolate the test. */
528 t
= cond_exec_get_condition (BB_END (bb
));
532 f_code
= reversed_comparison_code (t
, BB_END (bb
));
533 if (f_code
== UNKNOWN
)
536 f
= gen_rtx_fmt_ee (f_code
, GET_MODE (t
), XEXP (t
, 0), XEXP (t
, 1));
537 if (ce_info
->and_and_p
)
539 t
= gen_rtx_AND (GET_MODE (t
), true_expr
, t
);
540 f
= gen_rtx_IOR (GET_MODE (t
), false_expr
, f
);
544 t
= gen_rtx_IOR (GET_MODE (t
), true_expr
, t
);
545 f
= gen_rtx_AND (GET_MODE (t
), false_expr
, f
);
548 /* If the machine description needs to modify the tests, such as
549 setting a conditional execution register from a comparison, it can
551 #ifdef IFCVT_MODIFY_MULTIPLE_TESTS
552 IFCVT_MODIFY_MULTIPLE_TESTS (ce_info
, bb
, t
, f
);
554 /* See if the conversion failed. */
562 while (bb
!= last_test_bb
);
565 /* For IF-THEN-ELSE blocks, we don't allow modifications of the test
566 on then THEN block. */
567 then_mod_ok
= (else_bb
== NULL_BLOCK
);
569 /* Go through the THEN and ELSE blocks converting the insns if possible
570 to conditional execution. */
574 || ! cond_exec_process_insns (ce_info
, then_start
, then_end
,
575 false_expr
, false_prob_val
,
579 if (else_bb
&& else_end
580 && ! cond_exec_process_insns (ce_info
, else_start
, else_end
,
581 true_expr
, true_prob_val
, TRUE
))
584 /* If we cannot apply the changes, fail. Do not go through the normal fail
585 processing, since apply_change_group will call cancel_changes. */
586 if (! apply_change_group ())
588 #ifdef IFCVT_MODIFY_CANCEL
589 /* Cancel any machine dependent changes. */
590 IFCVT_MODIFY_CANCEL (ce_info
);
595 #ifdef IFCVT_MODIFY_FINAL
596 /* Do any machine dependent final modifications. */
597 IFCVT_MODIFY_FINAL (ce_info
);
600 /* Conversion succeeded. */
602 fprintf (dump_file
, "%d insn%s converted to conditional execution.\n",
603 n_insns
, (n_insns
== 1) ? " was" : "s were");
605 /* Merge the blocks! */
606 merge_if_block (ce_info
);
607 cond_exec_changed_p
= TRUE
;
611 #ifdef IFCVT_MODIFY_CANCEL
612 /* Cancel any machine dependent changes. */
613 IFCVT_MODIFY_CANCEL (ce_info
);
620 /* Used by noce_process_if_block to communicate with its subroutines.
622 The subroutines know that A and B may be evaluated freely. They
623 know that X is a register. They should insert new instructions
624 before cond_earliest. */
631 rtx jump
, cond
, cond_earliest
;
632 /* True if "b" was originally evaluated unconditionally. */
633 bool b_unconditional
;
636 static rtx
noce_emit_store_flag (struct noce_if_info
*, rtx
, int, int);
637 static int noce_try_move (struct noce_if_info
*);
638 static int noce_try_store_flag (struct noce_if_info
*);
639 static int noce_try_addcc (struct noce_if_info
*);
640 static int noce_try_store_flag_constants (struct noce_if_info
*);
641 static int noce_try_store_flag_mask (struct noce_if_info
*);
642 static rtx
noce_emit_cmove (struct noce_if_info
*, rtx
, enum rtx_code
, rtx
,
644 static int noce_try_cmove (struct noce_if_info
*);
645 static int noce_try_cmove_arith (struct noce_if_info
*);
646 static rtx
noce_get_alt_condition (struct noce_if_info
*, rtx
, rtx
*);
647 static int noce_try_minmax (struct noce_if_info
*);
648 static int noce_try_abs (struct noce_if_info
*);
649 static int noce_try_sign_mask (struct noce_if_info
*);
651 /* Helper function for noce_try_store_flag*. */
654 noce_emit_store_flag (struct noce_if_info
*if_info
, rtx x
, int reversep
,
657 rtx cond
= if_info
->cond
;
661 cond_complex
= (! general_operand (XEXP (cond
, 0), VOIDmode
)
662 || ! general_operand (XEXP (cond
, 1), VOIDmode
));
664 /* If earliest == jump, or when the condition is complex, try to
665 build the store_flag insn directly. */
668 cond
= XEXP (SET_SRC (pc_set (if_info
->jump
)), 0);
671 code
= reversed_comparison_code (cond
, if_info
->jump
);
673 code
= GET_CODE (cond
);
675 if ((if_info
->cond_earliest
== if_info
->jump
|| cond_complex
)
676 && (normalize
== 0 || STORE_FLAG_VALUE
== normalize
))
680 tmp
= gen_rtx_fmt_ee (code
, GET_MODE (x
), XEXP (cond
, 0),
682 tmp
= gen_rtx_SET (VOIDmode
, x
, tmp
);
685 tmp
= emit_insn (tmp
);
687 if (recog_memoized (tmp
) >= 0)
693 if_info
->cond_earliest
= if_info
->jump
;
701 /* Don't even try if the comparison operands or the mode of X are weird. */
702 if (cond_complex
|| !SCALAR_INT_MODE_P (GET_MODE (x
)))
705 return emit_store_flag (x
, code
, XEXP (cond
, 0),
706 XEXP (cond
, 1), VOIDmode
,
707 (code
== LTU
|| code
== LEU
708 || code
== GEU
|| code
== GTU
), normalize
);
711 /* Emit instruction to move an rtx, possibly into STRICT_LOW_PART.
712 X is the destination/target and Y is the value to copy. */
715 noce_emit_move_insn (rtx x
, rtx y
)
717 enum machine_mode outmode
, inmode
;
721 if (GET_CODE (x
) != STRICT_LOW_PART
)
723 emit_move_insn (x
, y
);
728 inner
= XEXP (outer
, 0);
729 outmode
= GET_MODE (outer
);
730 inmode
= GET_MODE (inner
);
731 bitpos
= SUBREG_BYTE (outer
) * BITS_PER_UNIT
;
732 store_bit_field (inner
, GET_MODE_BITSIZE (outmode
), bitpos
, outmode
, y
);
735 /* Return sequence of instructions generated by if conversion. This
736 function calls end_sequence() to end the current stream, ensures
737 that are instructions are unshared, recognizable non-jump insns.
738 On failure, this function returns a NULL_RTX. */
741 end_ifcvt_sequence (struct noce_if_info
*if_info
)
744 rtx seq
= get_insns ();
746 set_used_flags (if_info
->x
);
747 set_used_flags (if_info
->cond
);
748 unshare_all_rtl_in_chain (seq
);
751 /* Make sure that all of the instructions emitted are recognizable,
752 and that we haven't introduced a new jump instruction.
753 As an exercise for the reader, build a general mechanism that
754 allows proper placement of required clobbers. */
755 for (insn
= seq
; insn
; insn
= NEXT_INSN (insn
))
757 || recog_memoized (insn
) == -1)
763 /* Convert "if (a != b) x = a; else x = b" into "x = a" and
764 "if (a == b) x = a; else x = b" into "x = b". */
767 noce_try_move (struct noce_if_info
*if_info
)
769 rtx cond
= if_info
->cond
;
770 enum rtx_code code
= GET_CODE (cond
);
773 if (code
!= NE
&& code
!= EQ
)
776 /* This optimization isn't valid if either A or B could be a NaN
778 if (HONOR_NANS (GET_MODE (if_info
->x
))
779 || HONOR_SIGNED_ZEROS (GET_MODE (if_info
->x
)))
782 /* Check whether the operands of the comparison are A and in
784 if ((rtx_equal_p (if_info
->a
, XEXP (cond
, 0))
785 && rtx_equal_p (if_info
->b
, XEXP (cond
, 1)))
786 || (rtx_equal_p (if_info
->a
, XEXP (cond
, 1))
787 && rtx_equal_p (if_info
->b
, XEXP (cond
, 0))))
789 y
= (code
== EQ
) ? if_info
->a
: if_info
->b
;
791 /* Avoid generating the move if the source is the destination. */
792 if (! rtx_equal_p (if_info
->x
, y
))
795 noce_emit_move_insn (if_info
->x
, y
);
796 seq
= end_ifcvt_sequence (if_info
);
800 emit_insn_before_setloc (seq
, if_info
->jump
,
801 INSN_LOCATOR (if_info
->insn_a
));
808 /* Convert "if (test) x = 1; else x = 0".
810 Only try 0 and STORE_FLAG_VALUE here. Other combinations will be
811 tried in noce_try_store_flag_constants after noce_try_cmove has had
812 a go at the conversion. */
815 noce_try_store_flag (struct noce_if_info
*if_info
)
820 if (GET_CODE (if_info
->b
) == CONST_INT
821 && INTVAL (if_info
->b
) == STORE_FLAG_VALUE
822 && if_info
->a
== const0_rtx
)
824 else if (if_info
->b
== const0_rtx
825 && GET_CODE (if_info
->a
) == CONST_INT
826 && INTVAL (if_info
->a
) == STORE_FLAG_VALUE
827 && (reversed_comparison_code (if_info
->cond
, if_info
->jump
)
835 target
= noce_emit_store_flag (if_info
, if_info
->x
, reversep
, 0);
838 if (target
!= if_info
->x
)
839 noce_emit_move_insn (if_info
->x
, target
);
841 seq
= end_ifcvt_sequence (if_info
);
845 emit_insn_before_setloc (seq
, if_info
->jump
,
846 INSN_LOCATOR (if_info
->insn_a
));
856 /* Convert "if (test) x = a; else x = b", for A and B constant. */
859 noce_try_store_flag_constants (struct noce_if_info
*if_info
)
863 HOST_WIDE_INT itrue
, ifalse
, diff
, tmp
;
864 int normalize
, can_reverse
;
865 enum machine_mode mode
;
868 && GET_CODE (if_info
->a
) == CONST_INT
869 && GET_CODE (if_info
->b
) == CONST_INT
)
871 mode
= GET_MODE (if_info
->x
);
872 ifalse
= INTVAL (if_info
->a
);
873 itrue
= INTVAL (if_info
->b
);
875 /* Make sure we can represent the difference between the two values. */
876 if ((itrue
- ifalse
> 0)
877 != ((ifalse
< 0) != (itrue
< 0) ? ifalse
< 0 : ifalse
< itrue
))
880 diff
= trunc_int_for_mode (itrue
- ifalse
, mode
);
882 can_reverse
= (reversed_comparison_code (if_info
->cond
, if_info
->jump
)
886 if (diff
== STORE_FLAG_VALUE
|| diff
== -STORE_FLAG_VALUE
)
888 else if (ifalse
== 0 && exact_log2 (itrue
) >= 0
889 && (STORE_FLAG_VALUE
== 1
890 || BRANCH_COST
>= 2))
892 else if (itrue
== 0 && exact_log2 (ifalse
) >= 0 && can_reverse
893 && (STORE_FLAG_VALUE
== 1 || BRANCH_COST
>= 2))
894 normalize
= 1, reversep
= 1;
896 && (STORE_FLAG_VALUE
== -1
897 || BRANCH_COST
>= 2))
899 else if (ifalse
== -1 && can_reverse
900 && (STORE_FLAG_VALUE
== -1 || BRANCH_COST
>= 2))
901 normalize
= -1, reversep
= 1;
902 else if ((BRANCH_COST
>= 2 && STORE_FLAG_VALUE
== -1)
910 tmp
= itrue
; itrue
= ifalse
; ifalse
= tmp
;
911 diff
= trunc_int_for_mode (-diff
, mode
);
915 target
= noce_emit_store_flag (if_info
, if_info
->x
, reversep
, normalize
);
922 /* if (test) x = 3; else x = 4;
923 => x = 3 + (test == 0); */
924 if (diff
== STORE_FLAG_VALUE
|| diff
== -STORE_FLAG_VALUE
)
926 target
= expand_simple_binop (mode
,
927 (diff
== STORE_FLAG_VALUE
929 GEN_INT (ifalse
), target
, if_info
->x
, 0,
933 /* if (test) x = 8; else x = 0;
934 => x = (test != 0) << 3; */
935 else if (ifalse
== 0 && (tmp
= exact_log2 (itrue
)) >= 0)
937 target
= expand_simple_binop (mode
, ASHIFT
,
938 target
, GEN_INT (tmp
), if_info
->x
, 0,
942 /* if (test) x = -1; else x = b;
943 => x = -(test != 0) | b; */
944 else if (itrue
== -1)
946 target
= expand_simple_binop (mode
, IOR
,
947 target
, GEN_INT (ifalse
), if_info
->x
, 0,
951 /* if (test) x = a; else x = b;
952 => x = (-(test != 0) & (b - a)) + a; */
955 target
= expand_simple_binop (mode
, AND
,
956 target
, GEN_INT (diff
), if_info
->x
, 0,
959 target
= expand_simple_binop (mode
, PLUS
,
960 target
, GEN_INT (ifalse
),
961 if_info
->x
, 0, OPTAB_WIDEN
);
970 if (target
!= if_info
->x
)
971 noce_emit_move_insn (if_info
->x
, target
);
973 seq
= end_ifcvt_sequence (if_info
);
977 emit_insn_before_setloc (seq
, if_info
->jump
,
978 INSN_LOCATOR (if_info
->insn_a
));
985 /* Convert "if (test) foo++" into "foo += (test != 0)", and
986 similarly for "foo--". */
989 noce_try_addcc (struct noce_if_info
*if_info
)
992 int subtract
, normalize
;
995 && GET_CODE (if_info
->a
) == PLUS
996 && rtx_equal_p (XEXP (if_info
->a
, 0), if_info
->b
)
997 && (reversed_comparison_code (if_info
->cond
, if_info
->jump
)
1000 rtx cond
= if_info
->cond
;
1001 enum rtx_code code
= reversed_comparison_code (cond
, if_info
->jump
);
1003 /* First try to use addcc pattern. */
1004 if (general_operand (XEXP (cond
, 0), VOIDmode
)
1005 && general_operand (XEXP (cond
, 1), VOIDmode
))
1008 target
= emit_conditional_add (if_info
->x
, code
,
1013 XEXP (if_info
->a
, 1),
1014 GET_MODE (if_info
->x
),
1015 (code
== LTU
|| code
== GEU
1016 || code
== LEU
|| code
== GTU
));
1019 if (target
!= if_info
->x
)
1020 noce_emit_move_insn (if_info
->x
, target
);
1022 seq
= end_ifcvt_sequence (if_info
);
1026 emit_insn_before_setloc (seq
, if_info
->jump
,
1027 INSN_LOCATOR (if_info
->insn_a
));
1033 /* If that fails, construct conditional increment or decrement using
1035 if (BRANCH_COST
>= 2
1036 && (XEXP (if_info
->a
, 1) == const1_rtx
1037 || XEXP (if_info
->a
, 1) == constm1_rtx
))
1040 if (STORE_FLAG_VALUE
== INTVAL (XEXP (if_info
->a
, 1)))
1041 subtract
= 0, normalize
= 0;
1042 else if (-STORE_FLAG_VALUE
== INTVAL (XEXP (if_info
->a
, 1)))
1043 subtract
= 1, normalize
= 0;
1045 subtract
= 0, normalize
= INTVAL (XEXP (if_info
->a
, 1));
1048 target
= noce_emit_store_flag (if_info
,
1049 gen_reg_rtx (GET_MODE (if_info
->x
)),
1053 target
= expand_simple_binop (GET_MODE (if_info
->x
),
1054 subtract
? MINUS
: PLUS
,
1055 if_info
->b
, target
, if_info
->x
,
1059 if (target
!= if_info
->x
)
1060 noce_emit_move_insn (if_info
->x
, target
);
1062 seq
= end_ifcvt_sequence (if_info
);
1066 emit_insn_before_setloc (seq
, if_info
->jump
,
1067 INSN_LOCATOR (if_info
->insn_a
));
1077 /* Convert "if (test) x = 0;" to "x &= -(test == 0);" */
1080 noce_try_store_flag_mask (struct noce_if_info
*if_info
)
1086 if (! no_new_pseudos
1087 && (BRANCH_COST
>= 2
1088 || STORE_FLAG_VALUE
== -1)
1089 && ((if_info
->a
== const0_rtx
1090 && rtx_equal_p (if_info
->b
, if_info
->x
))
1091 || ((reversep
= (reversed_comparison_code (if_info
->cond
,
1094 && if_info
->b
== const0_rtx
1095 && rtx_equal_p (if_info
->a
, if_info
->x
))))
1098 target
= noce_emit_store_flag (if_info
,
1099 gen_reg_rtx (GET_MODE (if_info
->x
)),
1102 target
= expand_simple_binop (GET_MODE (if_info
->x
), AND
,
1104 target
, if_info
->x
, 0,
1109 if (target
!= if_info
->x
)
1110 noce_emit_move_insn (if_info
->x
, target
);
1112 seq
= end_ifcvt_sequence (if_info
);
1116 emit_insn_before_setloc (seq
, if_info
->jump
,
1117 INSN_LOCATOR (if_info
->insn_a
));
1127 /* Helper function for noce_try_cmove and noce_try_cmove_arith. */
1130 noce_emit_cmove (struct noce_if_info
*if_info
, rtx x
, enum rtx_code code
,
1131 rtx cmp_a
, rtx cmp_b
, rtx vfalse
, rtx vtrue
)
1133 /* If earliest == jump, try to build the cmove insn directly.
1134 This is helpful when combine has created some complex condition
1135 (like for alpha's cmovlbs) that we can't hope to regenerate
1136 through the normal interface. */
1138 if (if_info
->cond_earliest
== if_info
->jump
)
1142 tmp
= gen_rtx_fmt_ee (code
, GET_MODE (if_info
->cond
), cmp_a
, cmp_b
);
1143 tmp
= gen_rtx_IF_THEN_ELSE (GET_MODE (x
), tmp
, vtrue
, vfalse
);
1144 tmp
= gen_rtx_SET (VOIDmode
, x
, tmp
);
1147 tmp
= emit_insn (tmp
);
1149 if (recog_memoized (tmp
) >= 0)
1161 /* Don't even try if the comparison operands are weird. */
1162 if (! general_operand (cmp_a
, GET_MODE (cmp_a
))
1163 || ! general_operand (cmp_b
, GET_MODE (cmp_b
)))
1166 #if HAVE_conditional_move
1167 return emit_conditional_move (x
, code
, cmp_a
, cmp_b
, VOIDmode
,
1168 vtrue
, vfalse
, GET_MODE (x
),
1169 (code
== LTU
|| code
== GEU
1170 || code
== LEU
|| code
== GTU
));
1172 /* We'll never get here, as noce_process_if_block doesn't call the
1173 functions involved. Ifdef code, however, should be discouraged
1174 because it leads to typos in the code not selected. However,
1175 emit_conditional_move won't exist either. */
1180 /* Try only simple constants and registers here. More complex cases
1181 are handled in noce_try_cmove_arith after noce_try_store_flag_arith
1182 has had a go at it. */
1185 noce_try_cmove (struct noce_if_info
*if_info
)
1190 if ((CONSTANT_P (if_info
->a
) || register_operand (if_info
->a
, VOIDmode
))
1191 && (CONSTANT_P (if_info
->b
) || register_operand (if_info
->b
, VOIDmode
)))
1195 code
= GET_CODE (if_info
->cond
);
1196 target
= noce_emit_cmove (if_info
, if_info
->x
, code
,
1197 XEXP (if_info
->cond
, 0),
1198 XEXP (if_info
->cond
, 1),
1199 if_info
->a
, if_info
->b
);
1203 if (target
!= if_info
->x
)
1204 noce_emit_move_insn (if_info
->x
, target
);
1206 seq
= end_ifcvt_sequence (if_info
);
1210 emit_insn_before_setloc (seq
, if_info
->jump
,
1211 INSN_LOCATOR (if_info
->insn_a
));
1224 /* Try more complex cases involving conditional_move. */
1227 noce_try_cmove_arith (struct noce_if_info
*if_info
)
1238 /* A conditional move from two memory sources is equivalent to a
1239 conditional on their addresses followed by a load. Don't do this
1240 early because it'll screw alias analysis. Note that we've
1241 already checked for no side effects. */
1242 if (! no_new_pseudos
&& cse_not_expected
1243 && MEM_P (a
) && MEM_P (b
)
1244 && BRANCH_COST
>= 5)
1248 x
= gen_reg_rtx (Pmode
);
1252 /* ??? We could handle this if we knew that a load from A or B could
1253 not fault. This is also true if we've already loaded
1254 from the address along the path from ENTRY. */
1255 else if (may_trap_p (a
) || may_trap_p (b
))
1258 /* if (test) x = a + b; else x = c - d;
1265 code
= GET_CODE (if_info
->cond
);
1266 insn_a
= if_info
->insn_a
;
1267 insn_b
= if_info
->insn_b
;
1269 /* Total insn_rtx_cost should be smaller than branch cost. Exit
1270 if insn_rtx_cost can't be estimated. */
1273 insn_cost
= insn_rtx_cost (PATTERN (insn_a
));
1274 if (insn_cost
== 0 || insn_cost
> COSTS_N_INSNS (BRANCH_COST
))
1283 insn_cost
+= insn_rtx_cost (PATTERN (insn_b
));
1284 if (insn_cost
== 0 || insn_cost
> COSTS_N_INSNS (BRANCH_COST
))
1288 /* Possibly rearrange operands to make things come out more natural. */
1289 if (reversed_comparison_code (if_info
->cond
, if_info
->jump
) != UNKNOWN
)
1292 if (rtx_equal_p (b
, x
))
1294 else if (general_operand (b
, GET_MODE (b
)))
1299 code
= reversed_comparison_code (if_info
->cond
, if_info
->jump
);
1300 tmp
= a
, a
= b
, b
= tmp
;
1301 tmp
= insn_a
, insn_a
= insn_b
, insn_b
= tmp
;
1307 /* If either operand is complex, load it into a register first.
1308 The best way to do this is to copy the original insn. In this
1309 way we preserve any clobbers etc that the insn may have had.
1310 This is of course not possible in the IS_MEM case. */
1311 if (! general_operand (a
, GET_MODE (a
)))
1316 goto end_seq_and_fail
;
1320 tmp
= gen_reg_rtx (GET_MODE (a
));
1321 tmp
= emit_insn (gen_rtx_SET (VOIDmode
, tmp
, a
));
1324 goto end_seq_and_fail
;
1327 a
= gen_reg_rtx (GET_MODE (a
));
1328 tmp
= copy_rtx (insn_a
);
1329 set
= single_set (tmp
);
1331 tmp
= emit_insn (PATTERN (tmp
));
1333 if (recog_memoized (tmp
) < 0)
1334 goto end_seq_and_fail
;
1336 if (! general_operand (b
, GET_MODE (b
)))
1341 goto end_seq_and_fail
;
1345 tmp
= gen_reg_rtx (GET_MODE (b
));
1346 tmp
= emit_insn (gen_rtx_SET (VOIDmode
,
1351 goto end_seq_and_fail
;
1354 b
= gen_reg_rtx (GET_MODE (b
));
1355 tmp
= copy_rtx (insn_b
);
1356 set
= single_set (tmp
);
1358 tmp
= emit_insn (PATTERN (tmp
));
1360 if (recog_memoized (tmp
) < 0)
1361 goto end_seq_and_fail
;
1364 target
= noce_emit_cmove (if_info
, x
, code
, XEXP (if_info
->cond
, 0),
1365 XEXP (if_info
->cond
, 1), a
, b
);
1368 goto end_seq_and_fail
;
1370 /* If we're handling a memory for above, emit the load now. */
1373 tmp
= gen_rtx_MEM (GET_MODE (if_info
->x
), target
);
1375 /* Copy over flags as appropriate. */
1376 if (MEM_VOLATILE_P (if_info
->a
) || MEM_VOLATILE_P (if_info
->b
))
1377 MEM_VOLATILE_P (tmp
) = 1;
1378 if (MEM_IN_STRUCT_P (if_info
->a
) && MEM_IN_STRUCT_P (if_info
->b
))
1379 MEM_IN_STRUCT_P (tmp
) = 1;
1380 if (MEM_SCALAR_P (if_info
->a
) && MEM_SCALAR_P (if_info
->b
))
1381 MEM_SCALAR_P (tmp
) = 1;
1382 if (MEM_ALIAS_SET (if_info
->a
) == MEM_ALIAS_SET (if_info
->b
))
1383 set_mem_alias_set (tmp
, MEM_ALIAS_SET (if_info
->a
));
1385 MIN (MEM_ALIGN (if_info
->a
), MEM_ALIGN (if_info
->b
)));
1387 noce_emit_move_insn (if_info
->x
, tmp
);
1389 else if (target
!= x
)
1390 noce_emit_move_insn (x
, target
);
1392 tmp
= end_ifcvt_sequence (if_info
);
1396 emit_insn_before_setloc (tmp
, if_info
->jump
, INSN_LOCATOR (if_info
->insn_a
));
1404 /* For most cases, the simplified condition we found is the best
1405 choice, but this is not the case for the min/max/abs transforms.
1406 For these we wish to know that it is A or B in the condition. */
1409 noce_get_alt_condition (struct noce_if_info
*if_info
, rtx target
,
1412 rtx cond
, set
, insn
;
1415 /* If target is already mentioned in the known condition, return it. */
1416 if (reg_mentioned_p (target
, if_info
->cond
))
1418 *earliest
= if_info
->cond_earliest
;
1419 return if_info
->cond
;
1422 set
= pc_set (if_info
->jump
);
1423 cond
= XEXP (SET_SRC (set
), 0);
1425 = GET_CODE (XEXP (SET_SRC (set
), 2)) == LABEL_REF
1426 && XEXP (XEXP (SET_SRC (set
), 2), 0) == JUMP_LABEL (if_info
->jump
);
1428 /* If we're looking for a constant, try to make the conditional
1429 have that constant in it. There are two reasons why it may
1430 not have the constant we want:
1432 1. GCC may have needed to put the constant in a register, because
1433 the target can't compare directly against that constant. For
1434 this case, we look for a SET immediately before the comparison
1435 that puts a constant in that register.
1437 2. GCC may have canonicalized the conditional, for example
1438 replacing "if x < 4" with "if x <= 3". We can undo that (or
1439 make equivalent types of changes) to get the constants we need
1440 if they're off by one in the right direction. */
1442 if (GET_CODE (target
) == CONST_INT
)
1444 enum rtx_code code
= GET_CODE (if_info
->cond
);
1445 rtx op_a
= XEXP (if_info
->cond
, 0);
1446 rtx op_b
= XEXP (if_info
->cond
, 1);
1449 /* First, look to see if we put a constant in a register. */
1450 prev_insn
= PREV_INSN (if_info
->cond_earliest
);
1452 && INSN_P (prev_insn
)
1453 && GET_CODE (PATTERN (prev_insn
)) == SET
)
1455 rtx src
= find_reg_equal_equiv_note (prev_insn
);
1457 src
= SET_SRC (PATTERN (prev_insn
));
1458 if (GET_CODE (src
) == CONST_INT
)
1460 if (rtx_equal_p (op_a
, SET_DEST (PATTERN (prev_insn
))))
1462 else if (rtx_equal_p (op_b
, SET_DEST (PATTERN (prev_insn
))))
1465 if (GET_CODE (op_a
) == CONST_INT
)
1470 code
= swap_condition (code
);
1475 /* Now, look to see if we can get the right constant by
1476 adjusting the conditional. */
1477 if (GET_CODE (op_b
) == CONST_INT
)
1479 HOST_WIDE_INT desired_val
= INTVAL (target
);
1480 HOST_WIDE_INT actual_val
= INTVAL (op_b
);
1485 if (actual_val
== desired_val
+ 1)
1488 op_b
= GEN_INT (desired_val
);
1492 if (actual_val
== desired_val
- 1)
1495 op_b
= GEN_INT (desired_val
);
1499 if (actual_val
== desired_val
- 1)
1502 op_b
= GEN_INT (desired_val
);
1506 if (actual_val
== desired_val
+ 1)
1509 op_b
= GEN_INT (desired_val
);
1517 /* If we made any changes, generate a new conditional that is
1518 equivalent to what we started with, but has the right
1520 if (code
!= GET_CODE (if_info
->cond
)
1521 || op_a
!= XEXP (if_info
->cond
, 0)
1522 || op_b
!= XEXP (if_info
->cond
, 1))
1524 cond
= gen_rtx_fmt_ee (code
, GET_MODE (cond
), op_a
, op_b
);
1525 *earliest
= if_info
->cond_earliest
;
1530 cond
= canonicalize_condition (if_info
->jump
, cond
, reverse
,
1531 earliest
, target
, false, true);
1532 if (! cond
|| ! reg_mentioned_p (target
, cond
))
1535 /* We almost certainly searched back to a different place.
1536 Need to re-verify correct lifetimes. */
1538 /* X may not be mentioned in the range (cond_earliest, jump]. */
1539 for (insn
= if_info
->jump
; insn
!= *earliest
; insn
= PREV_INSN (insn
))
1540 if (INSN_P (insn
) && reg_overlap_mentioned_p (if_info
->x
, PATTERN (insn
)))
1543 /* A and B may not be modified in the range [cond_earliest, jump). */
1544 for (insn
= *earliest
; insn
!= if_info
->jump
; insn
= NEXT_INSN (insn
))
1546 && (modified_in_p (if_info
->a
, insn
)
1547 || modified_in_p (if_info
->b
, insn
)))
1553 /* Convert "if (a < b) x = a; else x = b;" to "x = min(a, b);", etc. */
1556 noce_try_minmax (struct noce_if_info
*if_info
)
1558 rtx cond
, earliest
, target
, seq
;
1559 enum rtx_code code
, op
;
1562 /* ??? Can't guarantee that expand_binop won't create pseudos. */
1566 /* ??? Reject modes with NaNs or signed zeros since we don't know how
1567 they will be resolved with an SMIN/SMAX. It wouldn't be too hard
1568 to get the target to tell us... */
1569 if (HONOR_SIGNED_ZEROS (GET_MODE (if_info
->x
))
1570 || HONOR_NANS (GET_MODE (if_info
->x
)))
1573 cond
= noce_get_alt_condition (if_info
, if_info
->a
, &earliest
);
1577 /* Verify the condition is of the form we expect, and canonicalize
1578 the comparison code. */
1579 code
= GET_CODE (cond
);
1580 if (rtx_equal_p (XEXP (cond
, 0), if_info
->a
))
1582 if (! rtx_equal_p (XEXP (cond
, 1), if_info
->b
))
1585 else if (rtx_equal_p (XEXP (cond
, 1), if_info
->a
))
1587 if (! rtx_equal_p (XEXP (cond
, 0), if_info
->b
))
1589 code
= swap_condition (code
);
1594 /* Determine what sort of operation this is. Note that the code is for
1595 a taken branch, so the code->operation mapping appears backwards. */
1628 target
= expand_simple_binop (GET_MODE (if_info
->x
), op
,
1629 if_info
->a
, if_info
->b
,
1630 if_info
->x
, unsignedp
, OPTAB_WIDEN
);
1636 if (target
!= if_info
->x
)
1637 noce_emit_move_insn (if_info
->x
, target
);
1639 seq
= end_ifcvt_sequence (if_info
);
1643 emit_insn_before_setloc (seq
, if_info
->jump
, INSN_LOCATOR (if_info
->insn_a
));
1644 if_info
->cond
= cond
;
1645 if_info
->cond_earliest
= earliest
;
1650 /* Convert "if (a < 0) x = -a; else x = a;" to "x = abs(a);", etc. */
1653 noce_try_abs (struct noce_if_info
*if_info
)
1655 rtx cond
, earliest
, target
, seq
, a
, b
, c
;
1658 /* ??? Can't guarantee that expand_binop won't create pseudos. */
1662 /* Recognize A and B as constituting an ABS or NABS. */
1665 if (GET_CODE (a
) == NEG
&& rtx_equal_p (XEXP (a
, 0), b
))
1667 else if (GET_CODE (b
) == NEG
&& rtx_equal_p (XEXP (b
, 0), a
))
1669 c
= a
; a
= b
; b
= c
;
1675 cond
= noce_get_alt_condition (if_info
, b
, &earliest
);
1679 /* Verify the condition is of the form we expect. */
1680 if (rtx_equal_p (XEXP (cond
, 0), b
))
1682 else if (rtx_equal_p (XEXP (cond
, 1), b
))
1687 /* Verify that C is zero. Search backward through the block for
1688 a REG_EQUAL note if necessary. */
1691 rtx insn
, note
= NULL
;
1692 for (insn
= earliest
;
1693 insn
!= BB_HEAD (if_info
->test_bb
);
1694 insn
= PREV_INSN (insn
))
1696 && ((note
= find_reg_note (insn
, REG_EQUAL
, c
))
1697 || (note
= find_reg_note (insn
, REG_EQUIV
, c
))))
1704 && GET_CODE (XEXP (c
, 0)) == SYMBOL_REF
1705 && CONSTANT_POOL_ADDRESS_P (XEXP (c
, 0)))
1706 c
= get_pool_constant (XEXP (c
, 0));
1708 /* Work around funny ideas get_condition has wrt canonicalization.
1709 Note that these rtx constants are known to be CONST_INT, and
1710 therefore imply integer comparisons. */
1711 if (c
== constm1_rtx
&& GET_CODE (cond
) == GT
)
1713 else if (c
== const1_rtx
&& GET_CODE (cond
) == LT
)
1715 else if (c
!= CONST0_RTX (GET_MODE (b
)))
1718 /* Determine what sort of operation this is. */
1719 switch (GET_CODE (cond
))
1738 target
= expand_abs_nojump (GET_MODE (if_info
->x
), b
, if_info
->x
, 1);
1740 /* ??? It's a quandary whether cmove would be better here, especially
1741 for integers. Perhaps combine will clean things up. */
1742 if (target
&& negate
)
1743 target
= expand_simple_unop (GET_MODE (target
), NEG
, target
, if_info
->x
, 0);
1751 if (target
!= if_info
->x
)
1752 noce_emit_move_insn (if_info
->x
, target
);
1754 seq
= end_ifcvt_sequence (if_info
);
1758 emit_insn_before_setloc (seq
, if_info
->jump
, INSN_LOCATOR (if_info
->insn_a
));
1759 if_info
->cond
= cond
;
1760 if_info
->cond_earliest
= earliest
;
1765 /* Convert "if (m < 0) x = b; else x = 0;" to "x = (m >> C) & b;". */
1768 noce_try_sign_mask (struct noce_if_info
*if_info
)
1770 rtx cond
, t
, m
, c
, seq
;
1771 enum machine_mode mode
;
1777 cond
= if_info
->cond
;
1778 code
= GET_CODE (cond
);
1783 if (if_info
->a
== const0_rtx
)
1785 if ((code
== LT
&& c
== const0_rtx
)
1786 || (code
== LE
&& c
== constm1_rtx
))
1789 else if (if_info
->b
== const0_rtx
)
1791 if ((code
== GE
&& c
== const0_rtx
)
1792 || (code
== GT
&& c
== constm1_rtx
))
1796 if (! t
|| side_effects_p (t
))
1799 /* We currently don't handle different modes. */
1800 mode
= GET_MODE (t
);
1801 if (GET_MODE (m
) != mode
)
1804 /* This is only profitable if T is cheap, or T is unconditionally
1805 executed/evaluated in the original insn sequence. */
1806 if (rtx_cost (t
, SET
) >= COSTS_N_INSNS (2)
1807 && (!if_info
->b_unconditional
1808 || t
!= if_info
->b
))
1812 /* Use emit_store_flag to generate "m < 0 ? -1 : 0" instead of expanding
1813 "(signed) m >> 31" directly. This benefits targets with specialized
1814 insns to obtain the signmask, but still uses ashr_optab otherwise. */
1815 m
= emit_store_flag (gen_reg_rtx (mode
), LT
, m
, const0_rtx
, mode
, 0, -1);
1816 t
= m
? expand_binop (mode
, and_optab
, m
, t
, NULL_RTX
, 0, OPTAB_DIRECT
)
1825 noce_emit_move_insn (if_info
->x
, t
);
1827 seq
= end_ifcvt_sequence (if_info
);
1831 emit_insn_before_setloc (seq
, if_info
->jump
, INSN_LOCATOR (if_info
->insn_a
));
1836 /* Similar to get_condition, only the resulting condition must be
1837 valid at JUMP, instead of at EARLIEST. */
1840 noce_get_condition (rtx jump
, rtx
*earliest
)
1845 if (! any_condjump_p (jump
))
1848 set
= pc_set (jump
);
1850 /* If this branches to JUMP_LABEL when the condition is false,
1851 reverse the condition. */
1852 reverse
= (GET_CODE (XEXP (SET_SRC (set
), 2)) == LABEL_REF
1853 && XEXP (XEXP (SET_SRC (set
), 2), 0) == JUMP_LABEL (jump
));
1855 /* If the condition variable is a register and is MODE_INT, accept it. */
1857 cond
= XEXP (SET_SRC (set
), 0);
1858 tmp
= XEXP (cond
, 0);
1859 if (REG_P (tmp
) && GET_MODE_CLASS (GET_MODE (tmp
)) == MODE_INT
)
1864 cond
= gen_rtx_fmt_ee (reverse_condition (GET_CODE (cond
)),
1865 GET_MODE (cond
), tmp
, XEXP (cond
, 1));
1869 /* Otherwise, fall back on canonicalize_condition to do the dirty
1870 work of manipulating MODE_CC values and COMPARE rtx codes. */
1871 return canonicalize_condition (jump
, cond
, reverse
, earliest
,
1872 NULL_RTX
, false, true);
1875 /* Return true if OP is ok for if-then-else processing. */
1878 noce_operand_ok (rtx op
)
1880 /* We special-case memories, so handle any of them with
1881 no address side effects. */
1883 return ! side_effects_p (XEXP (op
, 0));
1885 if (side_effects_p (op
))
1888 return ! may_trap_p (op
);
1891 /* Given a simple IF-THEN or IF-THEN-ELSE block, attempt to convert it
1892 without using conditional execution. Return TRUE if we were
1893 successful at converting the block. */
1896 noce_process_if_block (struct ce_if_block
* ce_info
)
1898 basic_block test_bb
= ce_info
->test_bb
; /* test block */
1899 basic_block then_bb
= ce_info
->then_bb
; /* THEN */
1900 basic_block else_bb
= ce_info
->else_bb
; /* ELSE or NULL */
1901 struct noce_if_info if_info
;
1904 rtx orig_x
, x
, a
, b
;
1907 /* We're looking for patterns of the form
1909 (1) if (...) x = a; else x = b;
1910 (2) x = b; if (...) x = a;
1911 (3) if (...) x = a; // as if with an initial x = x.
1913 The later patterns require jumps to be more expensive.
1915 ??? For future expansion, look for multiple X in such patterns. */
1917 /* If test is comprised of && or || elements, don't handle it unless it is
1918 the special case of && elements without an ELSE block. */
1919 if (ce_info
->num_multiple_test_blocks
)
1921 if (else_bb
|| ! ce_info
->and_and_p
)
1924 ce_info
->test_bb
= test_bb
= ce_info
->last_test_bb
;
1925 ce_info
->num_multiple_test_blocks
= 0;
1926 ce_info
->num_and_and_blocks
= 0;
1927 ce_info
->num_or_or_blocks
= 0;
1930 /* If this is not a standard conditional jump, we can't parse it. */
1931 jump
= BB_END (test_bb
);
1932 cond
= noce_get_condition (jump
, &if_info
.cond_earliest
);
1936 /* If the conditional jump is more than just a conditional
1937 jump, then we can not do if-conversion on this block. */
1938 if (! onlyjump_p (jump
))
1941 /* We must be comparing objects whose modes imply the size. */
1942 if (GET_MODE (XEXP (cond
, 0)) == BLKmode
)
1945 /* Look for one of the potential sets. */
1946 insn_a
= first_active_insn (then_bb
);
1948 || insn_a
!= last_active_insn (then_bb
, FALSE
)
1949 || (set_a
= single_set (insn_a
)) == NULL_RTX
)
1952 x
= SET_DEST (set_a
);
1953 a
= SET_SRC (set_a
);
1955 /* Look for the other potential set. Make sure we've got equivalent
1957 /* ??? This is overconservative. Storing to two different mems is
1958 as easy as conditionally computing the address. Storing to a
1959 single mem merely requires a scratch memory to use as one of the
1960 destination addresses; often the memory immediately below the
1961 stack pointer is available for this. */
1965 insn_b
= first_active_insn (else_bb
);
1967 || insn_b
!= last_active_insn (else_bb
, FALSE
)
1968 || (set_b
= single_set (insn_b
)) == NULL_RTX
1969 || ! rtx_equal_p (x
, SET_DEST (set_b
)))
1974 insn_b
= prev_nonnote_insn (if_info
.cond_earliest
);
1975 /* We're going to be moving the evaluation of B down from above
1976 COND_EARLIEST to JUMP. Make sure the relevant data is still
1979 || !NONJUMP_INSN_P (insn_b
)
1980 || (set_b
= single_set (insn_b
)) == NULL_RTX
1981 || ! rtx_equal_p (x
, SET_DEST (set_b
))
1982 || reg_overlap_mentioned_p (x
, SET_SRC (set_b
))
1983 || modified_between_p (SET_SRC (set_b
),
1984 PREV_INSN (if_info
.cond_earliest
), jump
)
1985 /* Likewise with X. In particular this can happen when
1986 noce_get_condition looks farther back in the instruction
1987 stream than one might expect. */
1988 || reg_overlap_mentioned_p (x
, cond
)
1989 || reg_overlap_mentioned_p (x
, a
)
1990 || modified_between_p (x
, PREV_INSN (if_info
.cond_earliest
), jump
))
1991 insn_b
= set_b
= NULL_RTX
;
1994 /* If x has side effects then only the if-then-else form is safe to
1995 convert. But even in that case we would need to restore any notes
1996 (such as REG_INC) at then end. That can be tricky if
1997 noce_emit_move_insn expands to more than one insn, so disable the
1998 optimization entirely for now if there are side effects. */
1999 if (side_effects_p (x
))
2002 b
= (set_b
? SET_SRC (set_b
) : x
);
2004 /* Only operate on register destinations, and even then avoid extending
2005 the lifetime of hard registers on small register class machines. */
2008 || (SMALL_REGISTER_CLASSES
2009 && REGNO (x
) < FIRST_PSEUDO_REGISTER
))
2011 if (no_new_pseudos
|| GET_MODE (x
) == BLKmode
)
2013 x
= gen_reg_rtx (GET_MODE (GET_CODE (x
) == STRICT_LOW_PART
2014 ? XEXP (x
, 0) : x
));
2017 /* Don't operate on sources that may trap or are volatile. */
2018 if (! noce_operand_ok (a
) || ! noce_operand_ok (b
))
2021 /* Set up the info block for our subroutines. */
2022 if_info
.test_bb
= test_bb
;
2023 if_info
.cond
= cond
;
2024 if_info
.jump
= jump
;
2025 if_info
.insn_a
= insn_a
;
2026 if_info
.insn_b
= insn_b
;
2030 if_info
.b_unconditional
= else_bb
== 0;
2032 /* Try optimizations in some approximation of a useful order. */
2033 /* ??? Should first look to see if X is live incoming at all. If it
2034 isn't, we don't need anything but an unconditional set. */
2036 /* Look and see if A and B are really the same. Avoid creating silly
2037 cmove constructs that no one will fix up later. */
2038 if (rtx_equal_p (a
, b
))
2040 /* If we have an INSN_B, we don't have to create any new rtl. Just
2041 move the instruction that we already have. If we don't have an
2042 INSN_B, that means that A == X, and we've got a noop move. In
2043 that case don't do anything and let the code below delete INSN_A. */
2044 if (insn_b
&& else_bb
)
2048 if (else_bb
&& insn_b
== BB_END (else_bb
))
2049 BB_END (else_bb
) = PREV_INSN (insn_b
);
2050 reorder_insns (insn_b
, insn_b
, PREV_INSN (jump
));
2052 /* If there was a REG_EQUAL note, delete it since it may have been
2053 true due to this insn being after a jump. */
2054 if ((note
= find_reg_note (insn_b
, REG_EQUAL
, NULL_RTX
)) != 0)
2055 remove_note (insn_b
, note
);
2059 /* If we have "x = b; if (...) x = a;", and x has side-effects, then
2060 x must be executed twice. */
2061 else if (insn_b
&& side_effects_p (orig_x
))
2068 /* Disallow the "if (...) x = a;" form (with an implicit "else x = x;")
2069 for most optimizations if writing to x may trap, i.e. it's a memory
2070 other than a static var or a stack slot. */
2073 && ! MEM_NOTRAP_P (orig_x
)
2074 && rtx_addr_can_trap_p (XEXP (orig_x
, 0)))
2076 if (HAVE_conditional_move
)
2078 if (noce_try_cmove (&if_info
))
2080 if (! HAVE_conditional_execution
2081 && noce_try_cmove_arith (&if_info
))
2087 if (noce_try_move (&if_info
))
2089 if (noce_try_store_flag (&if_info
))
2091 if (noce_try_minmax (&if_info
))
2093 if (noce_try_abs (&if_info
))
2095 if (HAVE_conditional_move
2096 && noce_try_cmove (&if_info
))
2098 if (! HAVE_conditional_execution
)
2100 if (noce_try_store_flag_constants (&if_info
))
2102 if (noce_try_addcc (&if_info
))
2104 if (noce_try_store_flag_mask (&if_info
))
2106 if (HAVE_conditional_move
2107 && noce_try_cmove_arith (&if_info
))
2109 if (noce_try_sign_mask (&if_info
))
2116 /* The original sets may now be killed. */
2117 delete_insn (insn_a
);
2119 /* Several special cases here: First, we may have reused insn_b above,
2120 in which case insn_b is now NULL. Second, we want to delete insn_b
2121 if it came from the ELSE block, because follows the now correct
2122 write that appears in the TEST block. However, if we got insn_b from
2123 the TEST block, it may in fact be loading data needed for the comparison.
2124 We'll let life_analysis remove the insn if it's really dead. */
2125 if (insn_b
&& else_bb
)
2126 delete_insn (insn_b
);
2128 /* The new insns will have been inserted immediately before the jump. We
2129 should be able to remove the jump with impunity, but the condition itself
2130 may have been modified by gcse to be shared across basic blocks. */
2133 /* If we used a temporary, fix it up now. */
2137 noce_emit_move_insn (orig_x
, x
);
2138 insn_b
= get_insns ();
2139 set_used_flags (orig_x
);
2140 unshare_all_rtl_in_chain (insn_b
);
2143 emit_insn_after_setloc (insn_b
, BB_END (test_bb
), INSN_LOCATOR (insn_a
));
2146 /* Merge the blocks! */
2147 merge_if_block (ce_info
);
2152 /* Attempt to convert an IF-THEN or IF-THEN-ELSE block into
2153 straight line code. Return true if successful. */
2156 process_if_block (struct ce_if_block
* ce_info
)
2158 if (! reload_completed
2159 && noce_process_if_block (ce_info
))
2162 if (HAVE_conditional_execution
&& reload_completed
)
2164 /* If we have && and || tests, try to first handle combining the && and
2165 || tests into the conditional code, and if that fails, go back and
2166 handle it without the && and ||, which at present handles the && case
2167 if there was no ELSE block. */
2168 if (cond_exec_process_if_block (ce_info
, TRUE
))
2171 if (ce_info
->num_multiple_test_blocks
)
2175 if (cond_exec_process_if_block (ce_info
, FALSE
))
2183 /* Merge the blocks and mark for local life update. */
2186 merge_if_block (struct ce_if_block
* ce_info
)
2188 basic_block test_bb
= ce_info
->test_bb
; /* last test block */
2189 basic_block then_bb
= ce_info
->then_bb
; /* THEN */
2190 basic_block else_bb
= ce_info
->else_bb
; /* ELSE or NULL */
2191 basic_block join_bb
= ce_info
->join_bb
; /* join block */
2192 basic_block combo_bb
;
2194 /* All block merging is done into the lower block numbers. */
2198 /* Merge any basic blocks to handle && and || subtests. Each of
2199 the blocks are on the fallthru path from the predecessor block. */
2200 if (ce_info
->num_multiple_test_blocks
> 0)
2202 basic_block bb
= test_bb
;
2203 basic_block last_test_bb
= ce_info
->last_test_bb
;
2204 basic_block fallthru
= block_fallthru (bb
);
2209 fallthru
= block_fallthru (bb
);
2210 merge_blocks (combo_bb
, bb
);
2213 while (bb
!= last_test_bb
);
2216 /* Merge TEST block into THEN block. Normally the THEN block won't have a
2217 label, but it might if there were || tests. That label's count should be
2218 zero, and it normally should be removed. */
2222 if (combo_bb
->global_live_at_end
)
2223 COPY_REG_SET (combo_bb
->global_live_at_end
,
2224 then_bb
->global_live_at_end
);
2225 merge_blocks (combo_bb
, then_bb
);
2229 /* The ELSE block, if it existed, had a label. That label count
2230 will almost always be zero, but odd things can happen when labels
2231 get their addresses taken. */
2234 merge_blocks (combo_bb
, else_bb
);
2238 /* If there was no join block reported, that means it was not adjacent
2239 to the others, and so we cannot merge them. */
2243 rtx last
= BB_END (combo_bb
);
2245 /* The outgoing edge for the current COMBO block should already
2246 be correct. Verify this. */
2247 if (EDGE_COUNT (combo_bb
->succs
) == 0)
2249 if (find_reg_note (last
, REG_NORETURN
, NULL
))
2251 else if (NONJUMP_INSN_P (last
)
2252 && GET_CODE (PATTERN (last
)) == TRAP_IF
2253 && TRAP_CONDITION (PATTERN (last
)) == const_true_rtx
)
2259 /* There should still be something at the end of the THEN or ELSE
2260 blocks taking us to our final destination. */
2261 else if (JUMP_P (last
))
2263 else if (EDGE_SUCC (combo_bb
, 0)->dest
== EXIT_BLOCK_PTR
2265 && SIBLING_CALL_P (last
))
2267 else if ((EDGE_SUCC (combo_bb
, 0)->flags
& EDGE_EH
)
2268 && can_throw_internal (last
))
2274 /* The JOIN block may have had quite a number of other predecessors too.
2275 Since we've already merged the TEST, THEN and ELSE blocks, we should
2276 have only one remaining edge from our if-then-else diamond. If there
2277 is more than one remaining edge, it must come from elsewhere. There
2278 may be zero incoming edges if the THEN block didn't actually join
2279 back up (as with a call to abort). */
2280 else if (EDGE_COUNT (join_bb
->preds
) < 2
2281 && join_bb
!= EXIT_BLOCK_PTR
)
2283 /* We can merge the JOIN. */
2284 if (combo_bb
->global_live_at_end
)
2285 COPY_REG_SET (combo_bb
->global_live_at_end
,
2286 join_bb
->global_live_at_end
);
2288 merge_blocks (combo_bb
, join_bb
);
2293 /* We cannot merge the JOIN. */
2295 /* The outgoing edge for the current COMBO block should already
2296 be correct. Verify this. */
2297 if (EDGE_COUNT (combo_bb
->succs
) > 1
2298 || EDGE_SUCC (combo_bb
, 0)->dest
!= join_bb
)
2301 /* Remove the jump and cruft from the end of the COMBO block. */
2302 if (join_bb
!= EXIT_BLOCK_PTR
)
2303 tidy_fallthru_edge (EDGE_SUCC (combo_bb
, 0));
2306 num_updated_if_blocks
++;
2309 /* Find a block ending in a simple IF condition and try to transform it
2310 in some way. When converting a multi-block condition, put the new code
2311 in the first such block and delete the rest. Return a pointer to this
2312 first block if some transformation was done. Return NULL otherwise. */
2315 find_if_header (basic_block test_bb
, int pass
)
2317 ce_if_block_t ce_info
;
2321 /* The kind of block we're looking for has exactly two successors. */
2322 if (EDGE_COUNT (test_bb
->succs
) != 2)
2325 then_edge
= EDGE_SUCC (test_bb
, 0);
2326 else_edge
= EDGE_SUCC (test_bb
, 1);
2328 /* Neither edge should be abnormal. */
2329 if ((then_edge
->flags
& EDGE_COMPLEX
)
2330 || (else_edge
->flags
& EDGE_COMPLEX
))
2333 /* Nor exit the loop. */
2334 if ((then_edge
->flags
& EDGE_LOOP_EXIT
)
2335 || (else_edge
->flags
& EDGE_LOOP_EXIT
))
2338 /* The THEN edge is canonically the one that falls through. */
2339 if (then_edge
->flags
& EDGE_FALLTHRU
)
2341 else if (else_edge
->flags
& EDGE_FALLTHRU
)
2344 else_edge
= then_edge
;
2348 /* Otherwise this must be a multiway branch of some sort. */
2351 memset (&ce_info
, '\0', sizeof (ce_info
));
2352 ce_info
.test_bb
= test_bb
;
2353 ce_info
.then_bb
= then_edge
->dest
;
2354 ce_info
.else_bb
= else_edge
->dest
;
2355 ce_info
.pass
= pass
;
2357 #ifdef IFCVT_INIT_EXTRA_FIELDS
2358 IFCVT_INIT_EXTRA_FIELDS (&ce_info
);
2361 if (find_if_block (&ce_info
))
2364 if (HAVE_trap
&& HAVE_conditional_trap
2365 && find_cond_trap (test_bb
, then_edge
, else_edge
))
2368 if (dom_computed
[CDI_POST_DOMINATORS
] >= DOM_NO_FAST_QUERY
2369 && (! HAVE_conditional_execution
|| reload_completed
))
2371 if (find_if_case_1 (test_bb
, then_edge
, else_edge
))
2373 if (find_if_case_2 (test_bb
, then_edge
, else_edge
))
2381 fprintf (dump_file
, "Conversion succeeded on pass %d.\n", pass
);
2382 return ce_info
.test_bb
;
2385 /* Return true if a block has two edges, one of which falls through to the next
2386 block, and the other jumps to a specific block, so that we can tell if the
2387 block is part of an && test or an || test. Returns either -1 or the number
2388 of non-note, non-jump, non-USE/CLOBBER insns in the block. */
2391 block_jumps_and_fallthru_p (basic_block cur_bb
, basic_block target_bb
)
2394 int fallthru_p
= FALSE
;
2401 if (!cur_bb
|| !target_bb
)
2404 /* If no edges, obviously it doesn't jump or fallthru. */
2405 if (EDGE_COUNT (cur_bb
->succs
) == 0)
2408 FOR_EACH_EDGE (cur_edge
, ei
, cur_bb
->succs
)
2410 if (cur_edge
->flags
& EDGE_COMPLEX
)
2411 /* Anything complex isn't what we want. */
2414 else if (cur_edge
->flags
& EDGE_FALLTHRU
)
2417 else if (cur_edge
->dest
== target_bb
)
2424 if ((jump_p
& fallthru_p
) == 0)
2427 /* Don't allow calls in the block, since this is used to group && and ||
2428 together for conditional execution support. ??? we should support
2429 conditional execution support across calls for IA-64 some day, but
2430 for now it makes the code simpler. */
2431 end
= BB_END (cur_bb
);
2432 insn
= BB_HEAD (cur_bb
);
2434 while (insn
!= NULL_RTX
)
2441 && GET_CODE (PATTERN (insn
)) != USE
2442 && GET_CODE (PATTERN (insn
)) != CLOBBER
)
2448 insn
= NEXT_INSN (insn
);
2454 /* Determine if a given basic block heads a simple IF-THEN or IF-THEN-ELSE
2455 block. If so, we'll try to convert the insns to not require the branch.
2456 Return TRUE if we were successful at converting the block. */
2459 find_if_block (struct ce_if_block
* ce_info
)
2461 basic_block test_bb
= ce_info
->test_bb
;
2462 basic_block then_bb
= ce_info
->then_bb
;
2463 basic_block else_bb
= ce_info
->else_bb
;
2464 basic_block join_bb
= NULL_BLOCK
;
2469 ce_info
->last_test_bb
= test_bb
;
2471 /* Discover if any fall through predecessors of the current test basic block
2472 were && tests (which jump to the else block) or || tests (which jump to
2474 if (HAVE_conditional_execution
&& reload_completed
2475 && EDGE_COUNT (test_bb
->preds
) == 1
2476 && EDGE_PRED (test_bb
, 0)->flags
== EDGE_FALLTHRU
)
2478 basic_block bb
= EDGE_PRED (test_bb
, 0)->src
;
2479 basic_block target_bb
;
2480 int max_insns
= MAX_CONDITIONAL_EXECUTE
;
2483 /* Determine if the preceding block is an && or || block. */
2484 if ((n_insns
= block_jumps_and_fallthru_p (bb
, else_bb
)) >= 0)
2486 ce_info
->and_and_p
= TRUE
;
2487 target_bb
= else_bb
;
2489 else if ((n_insns
= block_jumps_and_fallthru_p (bb
, then_bb
)) >= 0)
2491 ce_info
->and_and_p
= FALSE
;
2492 target_bb
= then_bb
;
2495 target_bb
= NULL_BLOCK
;
2497 if (target_bb
&& n_insns
<= max_insns
)
2499 int total_insns
= 0;
2502 ce_info
->last_test_bb
= test_bb
;
2504 /* Found at least one && or || block, look for more. */
2507 ce_info
->test_bb
= test_bb
= bb
;
2508 total_insns
+= n_insns
;
2511 if (EDGE_COUNT (bb
->preds
) != 1)
2514 bb
= EDGE_PRED (bb
, 0)->src
;
2515 n_insns
= block_jumps_and_fallthru_p (bb
, target_bb
);
2517 while (n_insns
>= 0 && (total_insns
+ n_insns
) <= max_insns
);
2519 ce_info
->num_multiple_test_blocks
= blocks
;
2520 ce_info
->num_multiple_test_insns
= total_insns
;
2522 if (ce_info
->and_and_p
)
2523 ce_info
->num_and_and_blocks
= blocks
;
2525 ce_info
->num_or_or_blocks
= blocks
;
2529 /* The THEN block of an IF-THEN combo must have exactly one predecessor,
2530 other than any || blocks which jump to the THEN block. */
2531 if ((EDGE_COUNT (then_bb
->preds
) - ce_info
->num_or_or_blocks
) != 1)
2534 /* The edges of the THEN and ELSE blocks cannot have complex edges. */
2535 FOR_EACH_EDGE (cur_edge
, ei
, then_bb
->preds
)
2537 if (cur_edge
->flags
& EDGE_COMPLEX
)
2541 FOR_EACH_EDGE (cur_edge
, ei
, else_bb
->preds
)
2543 if (cur_edge
->flags
& EDGE_COMPLEX
)
2547 /* The THEN block of an IF-THEN combo must have zero or one successors. */
2548 if (EDGE_COUNT (then_bb
->succs
) > 0
2549 && (EDGE_COUNT (then_bb
->succs
) > 1
2550 || (EDGE_SUCC (then_bb
, 0)->flags
& EDGE_COMPLEX
)
2551 || (flow2_completed
&& tablejump_p (BB_END (then_bb
), NULL
, NULL
))))
2554 /* If the THEN block has no successors, conditional execution can still
2555 make a conditional call. Don't do this unless the ELSE block has
2556 only one incoming edge -- the CFG manipulation is too ugly otherwise.
2557 Check for the last insn of the THEN block being an indirect jump, which
2558 is listed as not having any successors, but confuses the rest of the CE
2559 code processing. ??? we should fix this in the future. */
2560 if (EDGE_COUNT (then_bb
->succs
) == 0)
2562 if (EDGE_COUNT (else_bb
->preds
) == 1)
2564 rtx last_insn
= BB_END (then_bb
);
2567 && NOTE_P (last_insn
)
2568 && last_insn
!= BB_HEAD (then_bb
))
2569 last_insn
= PREV_INSN (last_insn
);
2572 && JUMP_P (last_insn
)
2573 && ! simplejump_p (last_insn
))
2577 else_bb
= NULL_BLOCK
;
2583 /* If the THEN block's successor is the other edge out of the TEST block,
2584 then we have an IF-THEN combo without an ELSE. */
2585 else if (EDGE_SUCC (then_bb
, 0)->dest
== else_bb
)
2588 else_bb
= NULL_BLOCK
;
2591 /* If the THEN and ELSE block meet in a subsequent block, and the ELSE
2592 has exactly one predecessor and one successor, and the outgoing edge
2593 is not complex, then we have an IF-THEN-ELSE combo. */
2594 else if (EDGE_COUNT (else_bb
->succs
) == 1
2595 && EDGE_SUCC (then_bb
, 0)->dest
== EDGE_SUCC (else_bb
, 0)->dest
2596 && EDGE_COUNT (else_bb
->preds
) == 1
2597 && ! (EDGE_SUCC (else_bb
, 0)->flags
& EDGE_COMPLEX
)
2598 && ! (flow2_completed
&& tablejump_p (BB_END (else_bb
), NULL
, NULL
)))
2599 join_bb
= EDGE_SUCC (else_bb
, 0)->dest
;
2601 /* Otherwise it is not an IF-THEN or IF-THEN-ELSE combination. */
2605 num_possible_if_blocks
++;
2610 "\nIF-THEN%s block found, pass %d, start block %d "
2611 "[insn %d], then %d [%d]",
2612 (else_bb
) ? "-ELSE" : "",
2615 BB_HEAD (test_bb
) ? (int)INSN_UID (BB_HEAD (test_bb
)) : -1,
2617 BB_HEAD (then_bb
) ? (int)INSN_UID (BB_HEAD (then_bb
)) : -1);
2620 fprintf (dump_file
, ", else %d [%d]",
2622 BB_HEAD (else_bb
) ? (int)INSN_UID (BB_HEAD (else_bb
)) : -1);
2624 fprintf (dump_file
, ", join %d [%d]",
2626 BB_HEAD (join_bb
) ? (int)INSN_UID (BB_HEAD (join_bb
)) : -1);
2628 if (ce_info
->num_multiple_test_blocks
> 0)
2629 fprintf (dump_file
, ", %d %s block%s last test %d [%d]",
2630 ce_info
->num_multiple_test_blocks
,
2631 (ce_info
->and_and_p
) ? "&&" : "||",
2632 (ce_info
->num_multiple_test_blocks
== 1) ? "" : "s",
2633 ce_info
->last_test_bb
->index
,
2634 ((BB_HEAD (ce_info
->last_test_bb
))
2635 ? (int)INSN_UID (BB_HEAD (ce_info
->last_test_bb
))
2638 fputc ('\n', dump_file
);
2641 /* Make sure IF, THEN, and ELSE, blocks are adjacent. Actually, we get the
2642 first condition for free, since we've already asserted that there's a
2643 fallthru edge from IF to THEN. Likewise for the && and || blocks, since
2644 we checked the FALLTHRU flag, those are already adjacent to the last IF
2646 /* ??? As an enhancement, move the ELSE block. Have to deal with
2647 BLOCK notes, if by no other means than aborting the merge if they
2648 exist. Sticky enough I don't want to think about it now. */
2650 if (else_bb
&& (next
= next
->next_bb
) != else_bb
)
2652 if ((next
= next
->next_bb
) != join_bb
&& join_bb
!= EXIT_BLOCK_PTR
)
2660 /* Do the real work. */
2661 ce_info
->else_bb
= else_bb
;
2662 ce_info
->join_bb
= join_bb
;
2664 return process_if_block (ce_info
);
2667 /* Convert a branch over a trap, or a branch
2668 to a trap, into a conditional trap. */
2671 find_cond_trap (basic_block test_bb
, edge then_edge
, edge else_edge
)
2673 basic_block then_bb
= then_edge
->dest
;
2674 basic_block else_bb
= else_edge
->dest
;
2675 basic_block other_bb
, trap_bb
;
2676 rtx trap
, jump
, cond
, cond_earliest
, seq
;
2679 /* Locate the block with the trap instruction. */
2680 /* ??? While we look for no successors, we really ought to allow
2681 EH successors. Need to fix merge_if_block for that to work. */
2682 if ((trap
= block_has_only_trap (then_bb
)) != NULL
)
2683 trap_bb
= then_bb
, other_bb
= else_bb
;
2684 else if ((trap
= block_has_only_trap (else_bb
)) != NULL
)
2685 trap_bb
= else_bb
, other_bb
= then_bb
;
2691 fprintf (dump_file
, "\nTRAP-IF block found, start %d, trap %d\n",
2692 test_bb
->index
, trap_bb
->index
);
2695 /* If this is not a standard conditional jump, we can't parse it. */
2696 jump
= BB_END (test_bb
);
2697 cond
= noce_get_condition (jump
, &cond_earliest
);
2701 /* If the conditional jump is more than just a conditional jump, then
2702 we can not do if-conversion on this block. */
2703 if (! onlyjump_p (jump
))
2706 /* We must be comparing objects whose modes imply the size. */
2707 if (GET_MODE (XEXP (cond
, 0)) == BLKmode
)
2710 /* Reverse the comparison code, if necessary. */
2711 code
= GET_CODE (cond
);
2712 if (then_bb
== trap_bb
)
2714 code
= reversed_comparison_code (cond
, jump
);
2715 if (code
== UNKNOWN
)
2719 /* Attempt to generate the conditional trap. */
2720 seq
= gen_cond_trap (code
, XEXP (cond
, 0),
2722 TRAP_CODE (PATTERN (trap
)));
2728 /* Emit the new insns before cond_earliest. */
2729 emit_insn_before_setloc (seq
, cond_earliest
, INSN_LOCATOR (trap
));
2731 /* Delete the trap block if possible. */
2732 remove_edge (trap_bb
== then_bb
? then_edge
: else_edge
);
2733 if (EDGE_COUNT (trap_bb
->preds
) == 0)
2734 delete_basic_block (trap_bb
);
2736 /* If the non-trap block and the test are now adjacent, merge them.
2737 Otherwise we must insert a direct branch. */
2738 if (test_bb
->next_bb
== other_bb
)
2740 struct ce_if_block new_ce_info
;
2742 memset (&new_ce_info
, '\0', sizeof (new_ce_info
));
2743 new_ce_info
.test_bb
= test_bb
;
2744 new_ce_info
.then_bb
= NULL
;
2745 new_ce_info
.else_bb
= NULL
;
2746 new_ce_info
.join_bb
= other_bb
;
2747 merge_if_block (&new_ce_info
);
2753 lab
= JUMP_LABEL (jump
);
2754 newjump
= emit_jump_insn_after (gen_jump (lab
), jump
);
2755 LABEL_NUSES (lab
) += 1;
2756 JUMP_LABEL (newjump
) = lab
;
2757 emit_barrier_after (newjump
);
2765 /* Subroutine of find_cond_trap: if BB contains only a trap insn,
2769 block_has_only_trap (basic_block bb
)
2773 /* We're not the exit block. */
2774 if (bb
== EXIT_BLOCK_PTR
)
2777 /* The block must have no successors. */
2778 if (EDGE_COUNT (bb
->succs
) > 0)
2781 /* The only instruction in the THEN block must be the trap. */
2782 trap
= first_active_insn (bb
);
2783 if (! (trap
== BB_END (bb
)
2784 && GET_CODE (PATTERN (trap
)) == TRAP_IF
2785 && TRAP_CONDITION (PATTERN (trap
)) == const_true_rtx
))
2791 /* Look for IF-THEN-ELSE cases in which one of THEN or ELSE is
2792 transformable, but not necessarily the other. There need be no
2795 Return TRUE if we were successful at converting the block.
2797 Cases we'd like to look at:
2800 if (test) goto over; // x not live
2808 if (! test) goto label;
2811 if (test) goto E; // x not live
2825 (3) // This one's really only interesting for targets that can do
2826 // multiway branching, e.g. IA-64 BBB bundles. For other targets
2827 // it results in multiple branches on a cache line, which often
2828 // does not sit well with predictors.
2830 if (test1) goto E; // predicted not taken
2846 (A) Don't do (2) if the branch is predicted against the block we're
2847 eliminating. Do it anyway if we can eliminate a branch; this requires
2848 that the sole successor of the eliminated block postdominate the other
2851 (B) With CE, on (3) we can steal from both sides of the if, creating
2860 Again, this is most useful if J postdominates.
2862 (C) CE substitutes for helpful life information.
2864 (D) These heuristics need a lot of work. */
2866 /* Tests for case 1 above. */
2869 find_if_case_1 (basic_block test_bb
, edge then_edge
, edge else_edge
)
2871 basic_block then_bb
= then_edge
->dest
;
2872 basic_block else_bb
= else_edge
->dest
, new_bb
;
2875 /* If we are partitioning hot/cold basic blocks, we don't want to
2876 mess up unconditional or indirect jumps that cross between hot
2879 Basic block partitioning may result in some jumps that appear to
2880 be optimizable (or blocks that appear to be mergeable), but which really
2881 must be left untouched (they are required to make it safely across
2882 partition boundaries). See the comments at the top of
2883 bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */
2885 if (flag_reorder_blocks_and_partition
2886 && ((BB_END (then_bb
)
2887 && find_reg_note (BB_END (then_bb
), REG_CROSSING_JUMP
, NULL_RTX
))
2888 || (BB_END (else_bb
)
2889 && find_reg_note (BB_END (else_bb
), REG_CROSSING_JUMP
,
2893 /* THEN has one successor. */
2894 if (EDGE_COUNT (then_bb
->succs
) != 1)
2897 /* THEN does not fall through, but is not strange either. */
2898 if (EDGE_SUCC (then_bb
, 0)->flags
& (EDGE_COMPLEX
| EDGE_FALLTHRU
))
2901 /* THEN has one predecessor. */
2902 if (EDGE_COUNT (then_bb
->preds
) != 1)
2905 /* THEN must do something. */
2906 if (forwarder_block_p (then_bb
))
2909 num_possible_if_blocks
++;
2912 "\nIF-CASE-1 found, start %d, then %d\n",
2913 test_bb
->index
, then_bb
->index
);
2915 /* THEN is small. */
2916 if (! cheap_bb_rtx_cost_p (then_bb
, COSTS_N_INSNS (BRANCH_COST
)))
2919 /* Registers set are dead, or are predicable. */
2920 if (! dead_or_predicable (test_bb
, then_bb
, else_bb
,
2921 EDGE_SUCC (then_bb
, 0)->dest
, 1))
2924 /* Conversion went ok, including moving the insns and fixing up the
2925 jump. Adjust the CFG to match. */
2927 bitmap_ior (test_bb
->global_live_at_end
,
2928 else_bb
->global_live_at_start
,
2929 then_bb
->global_live_at_end
);
2932 /* We can avoid creating a new basic block if then_bb is immediately
2933 followed by else_bb, i.e. deleting then_bb allows test_bb to fall
2936 if (then_bb
->next_bb
== else_bb
2937 && then_bb
->prev_bb
== test_bb
2938 && else_bb
!= EXIT_BLOCK_PTR
)
2940 redirect_edge_succ (FALLTHRU_EDGE (test_bb
), else_bb
);
2944 new_bb
= redirect_edge_and_branch_force (FALLTHRU_EDGE (test_bb
),
2947 then_bb_index
= then_bb
->index
;
2948 delete_basic_block (then_bb
);
2950 /* Make rest of code believe that the newly created block is the THEN_BB
2951 block we removed. */
2954 new_bb
->index
= then_bb_index
;
2955 BASIC_BLOCK (then_bb_index
) = new_bb
;
2956 /* Since the fallthru edge was redirected from test_bb to new_bb,
2957 we need to ensure that new_bb is in the same partition as
2958 test bb (you can not fall through across section boundaries). */
2959 BB_COPY_PARTITION (new_bb
, test_bb
);
2961 /* We've possibly created jump to next insn, cleanup_cfg will solve that
2965 num_updated_if_blocks
++;
2970 /* Test for case 2 above. */
2973 find_if_case_2 (basic_block test_bb
, edge then_edge
, edge else_edge
)
2975 basic_block then_bb
= then_edge
->dest
;
2976 basic_block else_bb
= else_edge
->dest
;
2980 /* If we are partitioning hot/cold basic blocks, we don't want to
2981 mess up unconditional or indirect jumps that cross between hot
2984 Basic block partitioning may result in some jumps that appear to
2985 be optimizable (or blocks that appear to be mergeable), but which really
2986 must be left untouched (they are required to make it safely across
2987 partition boundaries). See the comments at the top of
2988 bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */
2990 if (flag_reorder_blocks_and_partition
2991 && ((BB_END (then_bb
)
2992 && find_reg_note (BB_END (then_bb
), REG_CROSSING_JUMP
, NULL_RTX
))
2993 || (BB_END (else_bb
)
2994 && find_reg_note (BB_END (else_bb
), REG_CROSSING_JUMP
,
2998 /* ELSE has one successor. */
2999 if (EDGE_COUNT (else_bb
->succs
) != 1)
3002 else_succ
= EDGE_SUCC (else_bb
, 0);
3004 /* ELSE outgoing edge is not complex. */
3005 if (else_succ
->flags
& EDGE_COMPLEX
)
3008 /* ELSE has one predecessor. */
3009 if (EDGE_COUNT (else_bb
->preds
) != 1)
3012 /* THEN is not EXIT. */
3013 if (then_bb
->index
< 0)
3016 /* ELSE is predicted or SUCC(ELSE) postdominates THEN. */
3017 note
= find_reg_note (BB_END (test_bb
), REG_BR_PROB
, NULL_RTX
);
3018 if (note
&& INTVAL (XEXP (note
, 0)) >= REG_BR_PROB_BASE
/ 2)
3020 else if (else_succ
->dest
->index
< 0
3021 || dominated_by_p (CDI_POST_DOMINATORS
, then_bb
,
3027 num_possible_if_blocks
++;
3030 "\nIF-CASE-2 found, start %d, else %d\n",
3031 test_bb
->index
, else_bb
->index
);
3033 /* ELSE is small. */
3034 if (! cheap_bb_rtx_cost_p (else_bb
, COSTS_N_INSNS (BRANCH_COST
)))
3037 /* Registers set are dead, or are predicable. */
3038 if (! dead_or_predicable (test_bb
, else_bb
, then_bb
, else_succ
->dest
, 0))
3041 /* Conversion went ok, including moving the insns and fixing up the
3042 jump. Adjust the CFG to match. */
3044 bitmap_ior (test_bb
->global_live_at_end
,
3045 then_bb
->global_live_at_start
,
3046 else_bb
->global_live_at_end
);
3048 delete_basic_block (else_bb
);
3051 num_updated_if_blocks
++;
3053 /* ??? We may now fallthru from one of THEN's successors into a join
3054 block. Rerun cleanup_cfg? Examine things manually? Wait? */
3059 /* A subroutine of dead_or_predicable called through for_each_rtx.
3060 Return 1 if a memory is found. */
3063 find_memory (rtx
*px
, void *data ATTRIBUTE_UNUSED
)
3068 /* Used by the code above to perform the actual rtl transformations.
3069 Return TRUE if successful.
3071 TEST_BB is the block containing the conditional branch. MERGE_BB
3072 is the block containing the code to manipulate. NEW_DEST is the
3073 label TEST_BB should be branching to after the conversion.
3074 REVERSEP is true if the sense of the branch should be reversed. */
3077 dead_or_predicable (basic_block test_bb
, basic_block merge_bb
,
3078 basic_block other_bb
, basic_block new_dest
, int reversep
)
3080 rtx head
, end
, jump
, earliest
= NULL_RTX
, old_dest
, new_label
= NULL_RTX
;
3082 jump
= BB_END (test_bb
);
3084 /* Find the extent of the real code in the merge block. */
3085 head
= BB_HEAD (merge_bb
);
3086 end
= BB_END (merge_bb
);
3089 head
= NEXT_INSN (head
);
3094 head
= end
= NULL_RTX
;
3097 head
= NEXT_INSN (head
);
3104 head
= end
= NULL_RTX
;
3107 end
= PREV_INSN (end
);
3110 /* Disable handling dead code by conditional execution if the machine needs
3111 to do anything funny with the tests, etc. */
3112 #ifndef IFCVT_MODIFY_TESTS
3113 if (HAVE_conditional_execution
)
3115 /* In the conditional execution case, we have things easy. We know
3116 the condition is reversible. We don't have to check life info
3117 because we're going to conditionally execute the code anyway.
3118 All that's left is making sure the insns involved can actually
3123 cond
= cond_exec_get_condition (jump
);
3127 prob_val
= find_reg_note (jump
, REG_BR_PROB
, NULL_RTX
);
3129 prob_val
= XEXP (prob_val
, 0);
3133 enum rtx_code rev
= reversed_comparison_code (cond
, jump
);
3136 cond
= gen_rtx_fmt_ee (rev
, GET_MODE (cond
), XEXP (cond
, 0),
3139 prob_val
= GEN_INT (REG_BR_PROB_BASE
- INTVAL (prob_val
));
3142 if (! cond_exec_process_insns ((ce_if_block_t
*)0, head
, end
, cond
,
3151 /* In the non-conditional execution case, we have to verify that there
3152 are no trapping operations, no calls, no references to memory, and
3153 that any registers modified are dead at the branch site. */
3155 rtx insn
, cond
, prev
;
3156 regset merge_set
, tmp
, test_live
, test_set
;
3157 struct propagate_block_info
*pbi
;
3158 unsigned i
, fail
= 0;
3161 /* Check for no calls or trapping operations. */
3162 for (insn
= head
; ; insn
= NEXT_INSN (insn
))
3168 if (may_trap_p (PATTERN (insn
)))
3171 /* ??? Even non-trapping memories such as stack frame
3172 references must be avoided. For stores, we collect
3173 no lifetime info; for reads, we'd have to assert
3174 true_dependence false against every store in the
3176 if (for_each_rtx (&PATTERN (insn
), find_memory
, NULL
))
3183 if (! any_condjump_p (jump
))
3186 /* Find the extent of the conditional. */
3187 cond
= noce_get_condition (jump
, &earliest
);
3192 MERGE_SET = set of registers set in MERGE_BB
3193 TEST_LIVE = set of registers live at EARLIEST
3194 TEST_SET = set of registers set between EARLIEST and the
3195 end of the block. */
3197 tmp
= ALLOC_REG_SET (®_obstack
);
3198 merge_set
= ALLOC_REG_SET (®_obstack
);
3199 test_live
= ALLOC_REG_SET (®_obstack
);
3200 test_set
= ALLOC_REG_SET (®_obstack
);
3202 /* ??? bb->local_set is only valid during calculate_global_regs_live,
3203 so we must recompute usage for MERGE_BB. Not so bad, I suppose,
3204 since we've already asserted that MERGE_BB is small. */
3205 propagate_block (merge_bb
, tmp
, merge_set
, merge_set
, 0);
3207 /* For small register class machines, don't lengthen lifetimes of
3208 hard registers before reload. */
3209 if (SMALL_REGISTER_CLASSES
&& ! reload_completed
)
3211 EXECUTE_IF_SET_IN_BITMAP (merge_set
, 0, i
, bi
)
3213 if (i
< FIRST_PSEUDO_REGISTER
3215 && ! global_regs
[i
])
3220 /* For TEST, we're interested in a range of insns, not a whole block.
3221 Moreover, we're interested in the insns live from OTHER_BB. */
3223 COPY_REG_SET (test_live
, other_bb
->global_live_at_start
);
3224 pbi
= init_propagate_block_info (test_bb
, test_live
, test_set
, test_set
,
3227 for (insn
= jump
; ; insn
= prev
)
3229 prev
= propagate_one_insn (pbi
, insn
);
3230 if (insn
== earliest
)
3234 free_propagate_block_info (pbi
);
3236 /* We can perform the transformation if
3237 MERGE_SET & (TEST_SET | TEST_LIVE)
3239 TEST_SET & merge_bb->global_live_at_start
3242 if (bitmap_intersect_p (test_set
, merge_set
)
3243 || bitmap_intersect_p (test_live
, merge_set
)
3244 || bitmap_intersect_p (test_set
, merge_bb
->global_live_at_start
))
3248 FREE_REG_SET (merge_set
);
3249 FREE_REG_SET (test_live
);
3250 FREE_REG_SET (test_set
);
3257 /* We don't want to use normal invert_jump or redirect_jump because
3258 we don't want to delete_insn called. Also, we want to do our own
3259 change group management. */
3261 old_dest
= JUMP_LABEL (jump
);
3262 if (other_bb
!= new_dest
)
3264 new_label
= block_label (new_dest
);
3266 ? ! invert_jump_1 (jump
, new_label
)
3267 : ! redirect_jump_1 (jump
, new_label
))
3271 if (! apply_change_group ())
3274 if (other_bb
!= new_dest
)
3277 LABEL_NUSES (old_dest
) -= 1;
3279 LABEL_NUSES (new_label
) += 1;
3280 JUMP_LABEL (jump
) = new_label
;
3282 invert_br_probabilities (jump
);
3284 redirect_edge_succ (BRANCH_EDGE (test_bb
), new_dest
);
3287 gcov_type count
, probability
;
3288 count
= BRANCH_EDGE (test_bb
)->count
;
3289 BRANCH_EDGE (test_bb
)->count
= FALLTHRU_EDGE (test_bb
)->count
;
3290 FALLTHRU_EDGE (test_bb
)->count
= count
;
3291 probability
= BRANCH_EDGE (test_bb
)->probability
;
3292 BRANCH_EDGE (test_bb
)->probability
3293 = FALLTHRU_EDGE (test_bb
)->probability
;
3294 FALLTHRU_EDGE (test_bb
)->probability
= probability
;
3295 update_br_prob_note (test_bb
);
3299 /* Move the insns out of MERGE_BB to before the branch. */
3302 if (end
== BB_END (merge_bb
))
3303 BB_END (merge_bb
) = PREV_INSN (head
);
3305 if (squeeze_notes (&head
, &end
))
3308 reorder_insns (head
, end
, PREV_INSN (earliest
));
3311 /* Remove the jump and edge if we can. */
3312 if (other_bb
== new_dest
)
3315 remove_edge (BRANCH_EDGE (test_bb
));
3316 /* ??? Can't merge blocks here, as then_bb is still in use.
3317 At minimum, the merge will get done just before bb-reorder. */
3327 /* Main entry point for all if-conversion. */
3330 if_convert (int x_life_data_ok
)
3335 num_possible_if_blocks
= 0;
3336 num_updated_if_blocks
= 0;
3337 num_true_changes
= 0;
3338 life_data_ok
= (x_life_data_ok
!= 0);
3340 if ((! targetm
.cannot_modify_jumps_p ())
3341 && (!flag_reorder_blocks_and_partition
|| !no_new_pseudos
3342 || !targetm
.have_named_sections
))
3343 mark_loop_exit_edges ();
3345 /* Compute postdominators if we think we'll use them. */
3346 if (HAVE_conditional_execution
|| life_data_ok
)
3347 calculate_dominance_info (CDI_POST_DOMINATORS
);
3352 /* Go through each of the basic blocks looking for things to convert. If we
3353 have conditional execution, we make multiple passes to allow us to handle
3354 IF-THEN{-ELSE} blocks within other IF-THEN{-ELSE} blocks. */
3358 cond_exec_changed_p
= FALSE
;
3361 #ifdef IFCVT_MULTIPLE_DUMPS
3362 if (dump_file
&& pass
> 1)
3363 fprintf (dump_file
, "\n\n========== Pass %d ==========\n", pass
);
3369 while ((new_bb
= find_if_header (bb
, pass
)))
3373 #ifdef IFCVT_MULTIPLE_DUMPS
3374 if (dump_file
&& cond_exec_changed_p
)
3375 print_rtl_with_bb (dump_file
, get_insns ());
3378 while (cond_exec_changed_p
);
3380 #ifdef IFCVT_MULTIPLE_DUMPS
3382 fprintf (dump_file
, "\n\n========== no more changes\n");
3385 free_dominance_info (CDI_POST_DOMINATORS
);
3390 clear_aux_for_blocks ();
3392 /* Rebuild life info for basic blocks that require it. */
3393 if (num_true_changes
&& life_data_ok
)
3395 /* If we allocated new pseudos, we must resize the array for sched1. */
3396 if (max_regno
< max_reg_num ())
3398 max_regno
= max_reg_num ();
3399 allocate_reg_info (max_regno
, FALSE
, FALSE
);
3401 update_life_info_in_dirty_blocks (UPDATE_LIFE_GLOBAL_RM_NOTES
,
3402 PROP_DEATH_NOTES
| PROP_SCAN_DEAD_CODE
3403 | PROP_KILL_DEAD_CODE
);
3406 /* Write the final stats. */
3407 if (dump_file
&& num_possible_if_blocks
> 0)
3410 "\n%d possible IF blocks searched.\n",
3411 num_possible_if_blocks
);
3413 "%d IF blocks converted.\n",
3414 num_updated_if_blocks
);
3416 "%d true changes made.\n\n\n",
3420 #ifdef ENABLE_CHECKING
3421 verify_flow_info ();