1 /* Optimize jump instructions, for GNU compiler.
2 Copyright (C) 1987, 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997
3 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
5 This file is part of GNU CC.
7 GNU CC is free software; you can redistribute it and/or modify
8 it 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 GNU CC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU CC; see the file COPYING. If not, write to
19 the Free Software Foundation, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
22 /* This is the jump-optimization pass of the compiler.
23 It is run two or three times: once before cse, sometimes once after cse,
24 and once after reload (before final).
26 jump_optimize deletes unreachable code and labels that are not used.
27 It also deletes jumps that jump to the following insn,
28 and simplifies jumps around unconditional jumps and jumps
29 to unconditional jumps.
31 Each CODE_LABEL has a count of the times it is used
32 stored in the LABEL_NUSES internal field, and each JUMP_INSN
33 has one label that it refers to stored in the
34 JUMP_LABEL internal field. With this we can detect labels that
35 become unused because of the deletion of all the jumps that
36 formerly used them. The JUMP_LABEL info is sometimes looked
39 Optionally, cross-jumping can be done. Currently it is done
40 only the last time (when after reload and before final).
41 In fact, the code for cross-jumping now assumes that register
42 allocation has been done, since it uses `rtx_renumbered_equal_p'.
44 Jump optimization is done after cse when cse's constant-propagation
45 causes jumps to become unconditional or to be deleted.
47 Unreachable loops are not detected here, because the labels
48 have references and the insns appear reachable from the labels.
49 find_basic_blocks in flow.c finds and deletes such loops.
51 The subroutines delete_insn, redirect_jump, and invert_jump are used
52 from other passes as well. */
59 #include "hard-reg-set.h"
61 #include "insn-config.h"
62 #include "insn-attr.h"
72 /* ??? Eventually must record somehow the labels used by jumps
73 from nested functions. */
74 /* Pre-record the next or previous real insn for each label?
75 No, this pass is very fast anyway. */
76 /* Condense consecutive labels?
77 This would make life analysis faster, maybe. */
78 /* Optimize jump y; x: ... y: jumpif... x?
79 Don't know if it is worth bothering with. */
80 /* Optimize two cases of conditional jump to conditional jump?
81 This can never delete any instruction or make anything dead,
82 or even change what is live at any point.
83 So perhaps let combiner do it. */
85 /* Vector indexed by uid.
86 For each CODE_LABEL, index by its uid to get first unconditional jump
87 that jumps to the label.
88 For each JUMP_INSN, index by its uid to get the next unconditional jump
89 that jumps to the same label.
90 Element 0 is the start of a chain of all return insns.
91 (It is safe to use element 0 because insn uid 0 is not used. */
93 static rtx
*jump_chain
;
95 /* Maximum index in jump_chain. */
97 static int max_jump_chain
;
99 /* Indicates whether death notes are significant in cross jump analysis.
100 Normally they are not significant, because of A and B jump to C,
101 and R dies in A, it must die in B. But this might not be true after
102 stack register conversion, and we must compare death notes in that
105 static int cross_jump_death_matters
= 0;
107 static int init_label_info
PARAMS ((rtx
));
108 static void delete_barrier_successors
PARAMS ((rtx
));
109 static void mark_all_labels
PARAMS ((rtx
, int));
110 static rtx delete_unreferenced_labels
PARAMS ((rtx
));
111 static void delete_noop_moves
PARAMS ((rtx
));
112 static int duplicate_loop_exit_test
PARAMS ((rtx
));
113 static void find_cross_jump
PARAMS ((rtx
, rtx
, int, rtx
*, rtx
*));
114 static void do_cross_jump
PARAMS ((rtx
, rtx
, rtx
));
115 static int jump_back_p
PARAMS ((rtx
, rtx
));
116 static int tension_vector_labels
PARAMS ((rtx
, int));
117 static void delete_computation
PARAMS ((rtx
));
118 static void redirect_exp_1
PARAMS ((rtx
*, rtx
, rtx
, rtx
));
119 static int redirect_exp
PARAMS ((rtx
, rtx
, rtx
));
120 static void invert_exp_1
PARAMS ((rtx
));
121 static int invert_exp
PARAMS ((rtx
));
122 static void delete_from_jump_chain
PARAMS ((rtx
));
123 static int delete_labelref_insn
PARAMS ((rtx
, rtx
, int));
124 static void mark_modified_reg
PARAMS ((rtx
, rtx
, void *));
125 static void redirect_tablejump
PARAMS ((rtx
, rtx
));
126 static void jump_optimize_1
PARAMS ((rtx
, int, int, int, int, int));
127 static int returnjump_p_1
PARAMS ((rtx
*, void *));
128 static void delete_prior_computation
PARAMS ((rtx
, rtx
));
130 /* Main external entry point into the jump optimizer. See comments before
131 jump_optimize_1 for descriptions of the arguments. */
133 jump_optimize (f
, cross_jump
, noop_moves
, after_regscan
)
139 jump_optimize_1 (f
, cross_jump
, noop_moves
, after_regscan
, 0, 0);
142 /* Alternate entry into the jump optimizer. This entry point only rebuilds
143 the JUMP_LABEL field in jumping insns and REG_LABEL notes in non-jumping
146 rebuild_jump_labels (f
)
149 jump_optimize_1 (f
, 0, 0, 0, 1, 0);
152 /* Alternate entry into the jump optimizer. Do only trivial optimizations. */
155 jump_optimize_minimal (f
)
158 jump_optimize_1 (f
, 0, 0, 0, 0, 1);
161 /* Delete no-op jumps and optimize jumps to jumps
162 and jumps around jumps.
163 Delete unused labels and unreachable code.
165 If CROSS_JUMP is 1, detect matching code
166 before a jump and its destination and unify them.
167 If CROSS_JUMP is 2, do cross-jumping, but pay attention to death notes.
169 If NOOP_MOVES is nonzero, delete no-op move insns.
171 If AFTER_REGSCAN is nonzero, then this jump pass is being run immediately
172 after regscan, and it is safe to use regno_first_uid and regno_last_uid.
174 If MARK_LABELS_ONLY is nonzero, then we only rebuild the jump chain
175 and JUMP_LABEL field for jumping insns.
177 If `optimize' is zero, don't change any code,
178 just determine whether control drops off the end of the function.
179 This case occurs when we have -W and not -O.
180 It works because `delete_insn' checks the value of `optimize'
181 and refrains from actually deleting when that is 0.
183 If MINIMAL is nonzero, then we only perform trivial optimizations:
185 * Removal of unreachable code after BARRIERs.
186 * Removal of unreferenced CODE_LABELs.
187 * Removal of a jump to the next instruction.
188 * Removal of a conditional jump followed by an unconditional jump
189 to the same target as the conditional jump.
190 * Simplify a conditional jump around an unconditional jump.
191 * Simplify a jump to a jump.
192 * Delete extraneous line number notes.
196 jump_optimize_1 (f
, cross_jump
, noop_moves
, after_regscan
,
197 mark_labels_only
, minimal
)
202 int mark_labels_only
;
205 register rtx insn
, next
;
212 enum rtx_code reversed_code
;
215 cross_jump_death_matters
= (cross_jump
== 2);
216 max_uid
= init_label_info (f
) + 1;
218 /* Leave some extra room for labels and duplicate exit test insns
220 max_jump_chain
= max_uid
* 14 / 10;
221 jump_chain
= (rtx
*) xcalloc (max_jump_chain
, sizeof (rtx
));
223 mark_all_labels (f
, cross_jump
);
225 /* Keep track of labels used from static data; we don't track them
226 closely enough to delete them here, so make sure their reference
227 count doesn't drop to zero. */
229 for (insn
= forced_labels
; insn
; insn
= XEXP (insn
, 1))
230 if (GET_CODE (XEXP (insn
, 0)) == CODE_LABEL
)
231 LABEL_NUSES (XEXP (insn
, 0))++;
233 /* Keep track of labels used for marking handlers for exception
234 regions; they cannot usually be deleted. */
236 for (insn
= exception_handler_labels
; insn
; insn
= XEXP (insn
, 1))
237 if (GET_CODE (XEXP (insn
, 0)) == CODE_LABEL
)
238 LABEL_NUSES (XEXP (insn
, 0))++;
240 /* Quit now if we just wanted to rebuild the JUMP_LABEL and REG_LABEL
241 notes and recompute LABEL_NUSES. */
242 if (mark_labels_only
)
245 delete_barrier_successors (f
);
247 last_insn
= delete_unreferenced_labels (f
);
250 delete_noop_moves (f
);
252 /* Now iterate optimizing jumps until nothing changes over one pass. */
254 old_max_reg
= max_reg_num ();
259 for (insn
= f
; insn
; insn
= next
)
262 rtx temp
, temp1
, temp2
= NULL_RTX
;
263 rtx temp4 ATTRIBUTE_UNUSED
;
265 int this_is_any_uncondjump
;
266 int this_is_any_condjump
;
267 int this_is_onlyjump
;
269 next
= NEXT_INSN (insn
);
271 /* See if this is a NOTE_INSN_LOOP_BEG followed by an unconditional
272 jump. Try to optimize by duplicating the loop exit test if so.
273 This is only safe immediately after regscan, because it uses
274 the values of regno_first_uid and regno_last_uid. */
275 if (after_regscan
&& GET_CODE (insn
) == NOTE
276 && NOTE_LINE_NUMBER (insn
) == NOTE_INSN_LOOP_BEG
277 && (temp1
= next_nonnote_insn (insn
)) != 0
278 && any_uncondjump_p (temp1
)
279 && onlyjump_p (temp1
))
281 temp
= PREV_INSN (insn
);
282 if (duplicate_loop_exit_test (insn
))
285 next
= NEXT_INSN (temp
);
290 if (GET_CODE (insn
) != JUMP_INSN
)
293 this_is_any_condjump
= any_condjump_p (insn
);
294 this_is_any_uncondjump
= any_uncondjump_p (insn
);
295 this_is_onlyjump
= onlyjump_p (insn
);
297 /* Tension the labels in dispatch tables. */
299 if (GET_CODE (PATTERN (insn
)) == ADDR_VEC
)
300 changed
|= tension_vector_labels (PATTERN (insn
), 0);
301 if (GET_CODE (PATTERN (insn
)) == ADDR_DIFF_VEC
)
302 changed
|= tension_vector_labels (PATTERN (insn
), 1);
304 /* See if this jump goes to another jump and redirect if so. */
305 nlabel
= follow_jumps (JUMP_LABEL (insn
));
306 if (nlabel
!= JUMP_LABEL (insn
))
307 changed
|= redirect_jump (insn
, nlabel
, 1);
309 if (! optimize
|| minimal
)
312 /* If a dispatch table always goes to the same place,
313 get rid of it and replace the insn that uses it. */
315 if (GET_CODE (PATTERN (insn
)) == ADDR_VEC
316 || GET_CODE (PATTERN (insn
)) == ADDR_DIFF_VEC
)
319 rtx pat
= PATTERN (insn
);
320 int diff_vec_p
= GET_CODE (PATTERN (insn
)) == ADDR_DIFF_VEC
;
321 int len
= XVECLEN (pat
, diff_vec_p
);
322 rtx dispatch
= prev_real_insn (insn
);
325 for (i
= 0; i
< len
; i
++)
326 if (XEXP (XVECEXP (pat
, diff_vec_p
, i
), 0)
327 != XEXP (XVECEXP (pat
, diff_vec_p
, 0), 0))
332 && GET_CODE (dispatch
) == JUMP_INSN
333 && JUMP_LABEL (dispatch
) != 0
334 /* Don't mess with a casesi insn.
335 XXX according to the comment before computed_jump_p(),
336 all casesi insns should be a parallel of the jump
337 and a USE of a LABEL_REF. */
338 && ! ((set
= single_set (dispatch
)) != NULL
339 && (GET_CODE (SET_SRC (set
)) == IF_THEN_ELSE
))
340 && next_real_insn (JUMP_LABEL (dispatch
)) == insn
)
342 redirect_tablejump (dispatch
,
343 XEXP (XVECEXP (pat
, diff_vec_p
, 0), 0));
348 reallabelprev
= prev_active_insn (JUMP_LABEL (insn
));
350 /* Detect jump to following insn. */
351 if (reallabelprev
== insn
352 && (this_is_any_condjump
|| this_is_any_uncondjump
)
355 next
= next_real_insn (JUMP_LABEL (insn
));
358 /* Remove the "inactive" but "real" insns (i.e. uses and
359 clobbers) in between here and there. */
361 while ((temp
= next_real_insn (temp
)) != next
)
368 /* Detect a conditional jump going to the same place
369 as an immediately following unconditional jump. */
370 else if (this_is_any_condjump
&& this_is_onlyjump
371 && (temp
= next_active_insn (insn
)) != 0
372 && simplejump_p (temp
)
373 && (next_active_insn (JUMP_LABEL (insn
))
374 == next_active_insn (JUMP_LABEL (temp
))))
376 /* Don't mess up test coverage analysis. */
378 if (flag_test_coverage
&& !reload_completed
)
379 for (temp2
= insn
; temp2
!= temp
; temp2
= NEXT_INSN (temp2
))
380 if (GET_CODE (temp2
) == NOTE
&& NOTE_LINE_NUMBER (temp2
) > 0)
385 /* Ensure that we jump to the later of the two labels.
396 If we leave the goto L1, we'll incorrectly leave
397 return-reg dead for TEST true. */
399 temp2
= next_active_insn (JUMP_LABEL (insn
));
401 temp2
= get_last_insn ();
402 if (GET_CODE (temp2
) != CODE_LABEL
)
403 temp2
= prev_label (temp2
);
404 if (temp2
!= JUMP_LABEL (temp
))
405 redirect_jump (temp
, temp2
, 1);
413 /* Detect a conditional jump jumping over an unconditional jump. */
415 else if (this_is_any_condjump
416 && reallabelprev
!= 0
417 && GET_CODE (reallabelprev
) == JUMP_INSN
418 && prev_active_insn (reallabelprev
) == insn
419 && no_labels_between_p (insn
, reallabelprev
)
420 && any_uncondjump_p (reallabelprev
)
421 && onlyjump_p (reallabelprev
))
423 /* When we invert the unconditional jump, we will be
424 decrementing the usage count of its old label.
425 Make sure that we don't delete it now because that
426 might cause the following code to be deleted. */
427 rtx prev_uses
= prev_nonnote_insn (reallabelprev
);
428 rtx prev_label
= JUMP_LABEL (insn
);
431 ++LABEL_NUSES (prev_label
);
433 if (invert_jump (insn
, JUMP_LABEL (reallabelprev
), 1))
435 /* It is very likely that if there are USE insns before
436 this jump, they hold REG_DEAD notes. These REG_DEAD
437 notes are no longer valid due to this optimization,
438 and will cause the life-analysis that following passes
439 (notably delayed-branch scheduling) to think that
440 these registers are dead when they are not.
442 To prevent this trouble, we just remove the USE insns
443 from the insn chain. */
445 while (prev_uses
&& GET_CODE (prev_uses
) == INSN
446 && GET_CODE (PATTERN (prev_uses
)) == USE
)
448 rtx useless
= prev_uses
;
449 prev_uses
= prev_nonnote_insn (prev_uses
);
450 delete_insn (useless
);
453 delete_insn (reallabelprev
);
457 /* We can now safely delete the label if it is unreferenced
458 since the delete_insn above has deleted the BARRIER. */
459 if (prev_label
&& --LABEL_NUSES (prev_label
) == 0)
460 delete_insn (prev_label
);
462 next
= NEXT_INSN (insn
);
465 /* If we have an unconditional jump preceded by a USE, try to put
466 the USE before the target and jump there. This simplifies many
467 of the optimizations below since we don't have to worry about
468 dealing with these USE insns. We only do this if the label
469 being branch to already has the identical USE or if code
470 never falls through to that label. */
472 else if (this_is_any_uncondjump
473 && (temp
= prev_nonnote_insn (insn
)) != 0
474 && GET_CODE (temp
) == INSN
475 && GET_CODE (PATTERN (temp
)) == USE
476 && (temp1
= prev_nonnote_insn (JUMP_LABEL (insn
))) != 0
477 && (GET_CODE (temp1
) == BARRIER
478 || (GET_CODE (temp1
) == INSN
479 && rtx_equal_p (PATTERN (temp
), PATTERN (temp1
))))
480 /* Don't do this optimization if we have a loop containing
481 only the USE instruction, and the loop start label has
482 a usage count of 1. This is because we will redo this
483 optimization everytime through the outer loop, and jump
484 opt will never exit. */
485 && ! ((temp2
= prev_nonnote_insn (temp
)) != 0
486 && temp2
== JUMP_LABEL (insn
)
487 && LABEL_NUSES (temp2
) == 1))
489 if (GET_CODE (temp1
) == BARRIER
)
491 emit_insn_after (PATTERN (temp
), temp1
);
492 temp1
= NEXT_INSN (temp1
);
496 redirect_jump (insn
, get_label_before (temp1
), 1);
497 reallabelprev
= prev_real_insn (temp1
);
499 next
= NEXT_INSN (insn
);
503 /* Detect a conditional jump jumping over an unconditional trap. */
505 && this_is_any_condjump
&& this_is_onlyjump
506 && reallabelprev
!= 0
507 && GET_CODE (reallabelprev
) == INSN
508 && GET_CODE (PATTERN (reallabelprev
)) == TRAP_IF
509 && TRAP_CONDITION (PATTERN (reallabelprev
)) == const_true_rtx
510 && prev_active_insn (reallabelprev
) == insn
511 && no_labels_between_p (insn
, reallabelprev
)
512 && (temp2
= get_condition (insn
, &temp4
))
513 && ((reversed_code
= reversed_comparison_code (temp2
, insn
))
516 rtx
new = gen_cond_trap (reversed_code
,
517 XEXP (temp2
, 0), XEXP (temp2
, 1),
518 TRAP_CODE (PATTERN (reallabelprev
)));
522 emit_insn_before (new, temp4
);
523 delete_insn (reallabelprev
);
529 /* Detect a jump jumping to an unconditional trap. */
530 else if (HAVE_trap
&& this_is_onlyjump
531 && (temp
= next_active_insn (JUMP_LABEL (insn
)))
532 && GET_CODE (temp
) == INSN
533 && GET_CODE (PATTERN (temp
)) == TRAP_IF
534 && (this_is_any_uncondjump
535 || (this_is_any_condjump
536 && (temp2
= get_condition (insn
, &temp4
)))))
538 rtx tc
= TRAP_CONDITION (PATTERN (temp
));
540 if (tc
== const_true_rtx
541 || (! this_is_any_uncondjump
&& rtx_equal_p (temp2
, tc
)))
544 /* Replace an unconditional jump to a trap with a trap. */
545 if (this_is_any_uncondjump
)
547 emit_barrier_after (emit_insn_before (gen_trap (), insn
));
552 new = gen_cond_trap (GET_CODE (temp2
), XEXP (temp2
, 0),
554 TRAP_CODE (PATTERN (temp
)));
557 emit_insn_before (new, temp4
);
563 /* If the trap condition and jump condition are mutually
564 exclusive, redirect the jump to the following insn. */
565 else if (GET_RTX_CLASS (GET_CODE (tc
)) == '<'
566 && this_is_any_condjump
567 && swap_condition (GET_CODE (temp2
)) == GET_CODE (tc
)
568 && rtx_equal_p (XEXP (tc
, 0), XEXP (temp2
, 0))
569 && rtx_equal_p (XEXP (tc
, 1), XEXP (temp2
, 1))
570 && redirect_jump (insn
, get_label_after (temp
), 1))
579 /* Now that the jump has been tensioned,
580 try cross jumping: check for identical code
581 before the jump and before its target label. */
583 /* First, cross jumping of conditional jumps: */
585 if (cross_jump
&& condjump_p (insn
))
587 rtx newjpos
, newlpos
;
588 rtx x
= prev_real_insn (JUMP_LABEL (insn
));
590 /* A conditional jump may be crossjumped
591 only if the place it jumps to follows
592 an opposing jump that comes back here. */
594 if (x
!= 0 && ! jump_back_p (x
, insn
))
595 /* We have no opposing jump;
596 cannot cross jump this insn. */
600 /* TARGET is nonzero if it is ok to cross jump
601 to code before TARGET. If so, see if matches. */
603 find_cross_jump (insn
, x
, 2,
608 do_cross_jump (insn
, newjpos
, newlpos
);
609 /* Make the old conditional jump
610 into an unconditional one. */
611 PATTERN (insn
) = gen_jump (JUMP_LABEL (insn
));
612 INSN_CODE (insn
) = -1;
613 emit_barrier_after (insn
);
614 /* Add to jump_chain unless this is a new label
615 whose UID is too large. */
616 if (INSN_UID (JUMP_LABEL (insn
)) < max_jump_chain
)
618 jump_chain
[INSN_UID (insn
)]
619 = jump_chain
[INSN_UID (JUMP_LABEL (insn
))];
620 jump_chain
[INSN_UID (JUMP_LABEL (insn
))] = insn
;
627 /* Cross jumping of unconditional jumps:
628 a few differences. */
630 if (cross_jump
&& simplejump_p (insn
))
632 rtx newjpos
, newlpos
;
637 /* TARGET is nonzero if it is ok to cross jump
638 to code before TARGET. If so, see if matches. */
639 find_cross_jump (insn
, JUMP_LABEL (insn
), 1,
642 /* If cannot cross jump to code before the label,
643 see if we can cross jump to another jump to
645 /* Try each other jump to this label. */
646 if (INSN_UID (JUMP_LABEL (insn
)) < max_uid
)
647 for (target
= jump_chain
[INSN_UID (JUMP_LABEL (insn
))];
648 target
!= 0 && newjpos
== 0;
649 target
= jump_chain
[INSN_UID (target
)])
651 && JUMP_LABEL (target
) == JUMP_LABEL (insn
)
652 /* Ignore TARGET if it's deleted. */
653 && ! INSN_DELETED_P (target
))
654 find_cross_jump (insn
, target
, 2,
659 do_cross_jump (insn
, newjpos
, newlpos
);
665 /* This code was dead in the previous jump.c! */
666 if (cross_jump
&& GET_CODE (PATTERN (insn
)) == RETURN
)
668 /* Return insns all "jump to the same place"
669 so we can cross-jump between any two of them. */
671 rtx newjpos
, newlpos
, target
;
675 /* If cannot cross jump to code before the label,
676 see if we can cross jump to another jump to
678 /* Try each other jump to this label. */
679 for (target
= jump_chain
[0];
680 target
!= 0 && newjpos
== 0;
681 target
= jump_chain
[INSN_UID (target
)])
683 && ! INSN_DELETED_P (target
)
684 && GET_CODE (PATTERN (target
)) == RETURN
)
685 find_cross_jump (insn
, target
, 2,
690 do_cross_jump (insn
, newjpos
, newlpos
);
701 /* Delete extraneous line number notes.
702 Note that two consecutive notes for different lines are not really
703 extraneous. There should be some indication where that line belonged,
704 even if it became empty. */
709 for (insn
= f
; insn
; insn
= NEXT_INSN (insn
))
710 if (GET_CODE (insn
) == NOTE
)
712 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_FUNCTION_BEG
)
713 /* Any previous line note was for the prologue; gdb wants a new
714 note after the prologue even if it is for the same line. */
715 last_note
= NULL_RTX
;
716 else if (NOTE_LINE_NUMBER (insn
) >= 0)
718 /* Delete this note if it is identical to previous note. */
720 && NOTE_SOURCE_FILE (insn
) == NOTE_SOURCE_FILE (last_note
)
721 && NOTE_LINE_NUMBER (insn
) == NOTE_LINE_NUMBER (last_note
))
738 /* Initialize LABEL_NUSES and JUMP_LABEL fields. Delete any REG_LABEL
739 notes whose labels don't occur in the insn any more. Returns the
740 largest INSN_UID found. */
748 for (insn
= f
; insn
; insn
= NEXT_INSN (insn
))
750 if (GET_CODE (insn
) == CODE_LABEL
)
751 LABEL_NUSES (insn
) = (LABEL_PRESERVE_P (insn
) != 0);
752 else if (GET_CODE (insn
) == JUMP_INSN
)
753 JUMP_LABEL (insn
) = 0;
754 else if (GET_CODE (insn
) == INSN
|| GET_CODE (insn
) == CALL_INSN
)
758 for (note
= REG_NOTES (insn
); note
; note
= next
)
760 next
= XEXP (note
, 1);
761 if (REG_NOTE_KIND (note
) == REG_LABEL
762 && ! reg_mentioned_p (XEXP (note
, 0), PATTERN (insn
)))
763 remove_note (insn
, note
);
766 if (INSN_UID (insn
) > largest_uid
)
767 largest_uid
= INSN_UID (insn
);
773 /* Delete insns following barriers, up to next label.
775 Also delete no-op jumps created by gcse. */
778 delete_barrier_successors (f
)
784 for (insn
= f
; insn
;)
786 if (GET_CODE (insn
) == BARRIER
)
788 insn
= NEXT_INSN (insn
);
790 never_reached_warning (insn
);
792 while (insn
!= 0 && GET_CODE (insn
) != CODE_LABEL
)
794 if (GET_CODE (insn
) == JUMP_INSN
)
796 /* Detect when we're deleting a tablejump; get rid of
797 the jump table as well. */
798 rtx next1
= next_nonnote_insn (insn
);
799 rtx next2
= next1
? next_nonnote_insn (next1
) : 0;
800 if (next2
&& GET_CODE (next1
) == CODE_LABEL
801 && GET_CODE (next2
) == JUMP_INSN
802 && (GET_CODE (PATTERN (next2
)) == ADDR_VEC
803 || GET_CODE (PATTERN (next2
)) == ADDR_DIFF_VEC
))
809 insn
= delete_insn (insn
);
811 else if (GET_CODE (insn
) == NOTE
812 && NOTE_LINE_NUMBER (insn
) != NOTE_INSN_FUNCTION_END
)
813 insn
= NEXT_INSN (insn
);
815 insn
= delete_insn (insn
);
817 /* INSN is now the code_label. */
820 /* Also remove (set (pc) (pc)) insns which can be created by
821 gcse. We eliminate such insns now to avoid having them
822 cause problems later. */
823 else if (GET_CODE (insn
) == JUMP_INSN
824 && (set
= pc_set (insn
)) != NULL
825 && SET_SRC (set
) == pc_rtx
826 && SET_DEST (set
) == pc_rtx
827 && onlyjump_p (insn
))
828 insn
= delete_insn (insn
);
831 insn
= NEXT_INSN (insn
);
835 /* Mark the label each jump jumps to.
836 Combine consecutive labels, and count uses of labels.
838 For each label, make a chain (using `jump_chain')
839 of all the *unconditional* jumps that jump to it;
840 also make a chain of all returns.
842 CROSS_JUMP indicates whether we are doing cross jumping
843 and if we are whether we will be paying attention to
844 death notes or not. */
847 mark_all_labels (f
, cross_jump
)
853 for (insn
= f
; insn
; insn
= NEXT_INSN (insn
))
856 if (GET_CODE (insn
) == CALL_INSN
857 && GET_CODE (PATTERN (insn
)) == CALL_PLACEHOLDER
)
859 mark_all_labels (XEXP (PATTERN (insn
), 0), cross_jump
);
860 mark_all_labels (XEXP (PATTERN (insn
), 1), cross_jump
);
861 mark_all_labels (XEXP (PATTERN (insn
), 2), cross_jump
);
863 /* Canonicalize the tail recursion label attached to the
864 CALL_PLACEHOLDER insn. */
865 if (XEXP (PATTERN (insn
), 3))
867 rtx label_ref
= gen_rtx_LABEL_REF (VOIDmode
,
868 XEXP (PATTERN (insn
), 3));
869 mark_jump_label (label_ref
, insn
, cross_jump
, 0);
870 XEXP (PATTERN (insn
), 3) = XEXP (label_ref
, 0);
876 mark_jump_label (PATTERN (insn
), insn
, cross_jump
, 0);
877 if (! INSN_DELETED_P (insn
) && GET_CODE (insn
) == JUMP_INSN
)
879 /* When we know the LABEL_REF contained in a REG used in
880 an indirect jump, we'll have a REG_LABEL note so that
881 flow can tell where it's going. */
882 if (JUMP_LABEL (insn
) == 0)
884 rtx label_note
= find_reg_note (insn
, REG_LABEL
, NULL_RTX
);
887 /* But a LABEL_REF around the REG_LABEL note, so
888 that we can canonicalize it. */
889 rtx label_ref
= gen_rtx_LABEL_REF (VOIDmode
,
890 XEXP (label_note
, 0));
892 mark_jump_label (label_ref
, insn
, cross_jump
, 0);
893 XEXP (label_note
, 0) = XEXP (label_ref
, 0);
894 JUMP_LABEL (insn
) = XEXP (label_note
, 0);
897 if (JUMP_LABEL (insn
) != 0 && simplejump_p (insn
))
899 jump_chain
[INSN_UID (insn
)]
900 = jump_chain
[INSN_UID (JUMP_LABEL (insn
))];
901 jump_chain
[INSN_UID (JUMP_LABEL (insn
))] = insn
;
903 if (GET_CODE (PATTERN (insn
)) == RETURN
)
905 jump_chain
[INSN_UID (insn
)] = jump_chain
[0];
906 jump_chain
[0] = insn
;
912 /* Delete all labels already not referenced.
913 Also find and return the last insn. */
916 delete_unreferenced_labels (f
)
919 rtx final
= NULL_RTX
;
922 for (insn
= f
; insn
;)
924 if (GET_CODE (insn
) == CODE_LABEL
925 && LABEL_NUSES (insn
) == 0
926 && LABEL_ALTERNATE_NAME (insn
) == NULL
)
927 insn
= delete_insn (insn
);
931 insn
= NEXT_INSN (insn
);
938 /* Delete various simple forms of moves which have no necessary
942 delete_noop_moves (f
)
947 for (insn
= f
; insn
;)
949 next
= NEXT_INSN (insn
);
951 if (GET_CODE (insn
) == INSN
)
953 register rtx body
= PATTERN (insn
);
955 /* Detect and delete no-op move instructions
956 resulting from not allocating a parameter in a register. */
958 if (GET_CODE (body
) == SET
&& set_noop_p (body
))
959 delete_computation (insn
);
961 /* Detect and ignore no-op move instructions
962 resulting from smart or fortuitous register allocation. */
964 else if (GET_CODE (body
) == SET
)
966 int sreg
= true_regnum (SET_SRC (body
));
967 int dreg
= true_regnum (SET_DEST (body
));
969 if (sreg
== dreg
&& sreg
>= 0)
971 else if (sreg
>= 0 && dreg
>= 0)
974 rtx tem
= find_equiv_reg (NULL_RTX
, insn
, 0,
976 GET_MODE (SET_SRC (body
)));
979 && GET_MODE (tem
) == GET_MODE (SET_DEST (body
)))
981 /* DREG may have been the target of a REG_DEAD note in
982 the insn which makes INSN redundant. If so, reorg
983 would still think it is dead. So search for such a
984 note and delete it if we find it. */
985 if (! find_regno_note (insn
, REG_UNUSED
, dreg
))
986 for (trial
= prev_nonnote_insn (insn
);
987 trial
&& GET_CODE (trial
) != CODE_LABEL
;
988 trial
= prev_nonnote_insn (trial
))
989 if (find_regno_note (trial
, REG_DEAD
, dreg
))
991 remove_death (dreg
, trial
);
995 /* Deleting insn could lose a death-note for SREG. */
996 if ((trial
= find_regno_note (insn
, REG_DEAD
, sreg
)))
998 /* Change this into a USE so that we won't emit
999 code for it, but still can keep the note. */
1001 = gen_rtx_USE (VOIDmode
, XEXP (trial
, 0));
1002 INSN_CODE (insn
) = -1;
1003 /* Remove all reg notes but the REG_DEAD one. */
1004 REG_NOTES (insn
) = trial
;
1005 XEXP (trial
, 1) = NULL_RTX
;
1011 else if (dreg
>= 0 && CONSTANT_P (SET_SRC (body
))
1012 && find_equiv_reg (SET_SRC (body
), insn
, 0, dreg
,
1013 NULL
, 0, GET_MODE (SET_DEST (body
))))
1015 /* This handles the case where we have two consecutive
1016 assignments of the same constant to pseudos that didn't
1017 get a hard reg. Each SET from the constant will be
1018 converted into a SET of the spill register and an
1019 output reload will be made following it. This produces
1020 two loads of the same constant into the same spill
1025 /* Look back for a death note for the first reg.
1026 If there is one, it is no longer accurate. */
1027 while (in_insn
&& GET_CODE (in_insn
) != CODE_LABEL
)
1029 if ((GET_CODE (in_insn
) == INSN
1030 || GET_CODE (in_insn
) == JUMP_INSN
)
1031 && find_regno_note (in_insn
, REG_DEAD
, dreg
))
1033 remove_death (dreg
, in_insn
);
1036 in_insn
= PREV_INSN (in_insn
);
1039 /* Delete the second load of the value. */
1043 else if (GET_CODE (body
) == PARALLEL
)
1045 /* If each part is a set between two identical registers or
1046 a USE or CLOBBER, delete the insn. */
1050 for (i
= XVECLEN (body
, 0) - 1; i
>= 0; i
--)
1052 tem
= XVECEXP (body
, 0, i
);
1053 if (GET_CODE (tem
) == USE
|| GET_CODE (tem
) == CLOBBER
)
1056 if (GET_CODE (tem
) != SET
1057 || (sreg
= true_regnum (SET_SRC (tem
))) < 0
1058 || (dreg
= true_regnum (SET_DEST (tem
))) < 0
1071 /* LOOP_START is a NOTE_INSN_LOOP_BEG note that is followed by an unconditional
1072 jump. Assume that this unconditional jump is to the exit test code. If
1073 the code is sufficiently simple, make a copy of it before INSN,
1074 followed by a jump to the exit of the loop. Then delete the unconditional
1077 Return 1 if we made the change, else 0.
1079 This is only safe immediately after a regscan pass because it uses the
1080 values of regno_first_uid and regno_last_uid. */
1083 duplicate_loop_exit_test (loop_start
)
1086 rtx insn
, set
, reg
, p
, link
;
1087 rtx copy
= 0, first_copy
= 0;
1089 rtx exitcode
= NEXT_INSN (JUMP_LABEL (next_nonnote_insn (loop_start
)));
1091 int max_reg
= max_reg_num ();
1094 /* Scan the exit code. We do not perform this optimization if any insn:
1098 has a REG_RETVAL or REG_LIBCALL note (hard to adjust)
1099 is a NOTE_INSN_LOOP_BEG because this means we have a nested loop
1100 is a NOTE_INSN_BLOCK_{BEG,END} because duplicating these notes
1103 We also do not do this if we find an insn with ASM_OPERANDS. While
1104 this restriction should not be necessary, copying an insn with
1105 ASM_OPERANDS can confuse asm_noperands in some cases.
1107 Also, don't do this if the exit code is more than 20 insns. */
1109 for (insn
= exitcode
;
1111 && ! (GET_CODE (insn
) == NOTE
1112 && NOTE_LINE_NUMBER (insn
) == NOTE_INSN_LOOP_END
);
1113 insn
= NEXT_INSN (insn
))
1115 switch (GET_CODE (insn
))
1121 /* We could be in front of the wrong NOTE_INSN_LOOP_END if there is
1122 a jump immediately after the loop start that branches outside
1123 the loop but within an outer loop, near the exit test.
1124 If we copied this exit test and created a phony
1125 NOTE_INSN_LOOP_VTOP, this could make instructions immediately
1126 before the exit test look like these could be safely moved
1127 out of the loop even if they actually may be never executed.
1128 This can be avoided by checking here for NOTE_INSN_LOOP_CONT. */
1130 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_LOOP_BEG
1131 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_LOOP_CONT
)
1135 && (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
1136 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
))
1137 /* If we were to duplicate this code, we would not move
1138 the BLOCK notes, and so debugging the moved code would
1139 be difficult. Thus, we only move the code with -O2 or
1146 /* The code below would grossly mishandle REG_WAS_0 notes,
1147 so get rid of them here. */
1148 while ((p
= find_reg_note (insn
, REG_WAS_0
, NULL_RTX
)) != 0)
1149 remove_note (insn
, p
);
1150 if (++num_insns
> 20
1151 || find_reg_note (insn
, REG_RETVAL
, NULL_RTX
)
1152 || find_reg_note (insn
, REG_LIBCALL
, NULL_RTX
))
1160 /* Unless INSN is zero, we can do the optimization. */
1166 /* See if any insn sets a register only used in the loop exit code and
1167 not a user variable. If so, replace it with a new register. */
1168 for (insn
= exitcode
; insn
!= lastexit
; insn
= NEXT_INSN (insn
))
1169 if (GET_CODE (insn
) == INSN
1170 && (set
= single_set (insn
)) != 0
1171 && ((reg
= SET_DEST (set
), GET_CODE (reg
) == REG
)
1172 || (GET_CODE (reg
) == SUBREG
1173 && (reg
= SUBREG_REG (reg
), GET_CODE (reg
) == REG
)))
1174 && REGNO (reg
) >= FIRST_PSEUDO_REGISTER
1175 && REGNO_FIRST_UID (REGNO (reg
)) == INSN_UID (insn
))
1177 for (p
= NEXT_INSN (insn
); p
!= lastexit
; p
= NEXT_INSN (p
))
1178 if (REGNO_LAST_UID (REGNO (reg
)) == INSN_UID (p
))
1183 /* We can do the replacement. Allocate reg_map if this is the
1184 first replacement we found. */
1186 reg_map
= (rtx
*) xcalloc (max_reg
, sizeof (rtx
));
1188 REG_LOOP_TEST_P (reg
) = 1;
1190 reg_map
[REGNO (reg
)] = gen_reg_rtx (GET_MODE (reg
));
1194 /* Now copy each insn. */
1195 for (insn
= exitcode
; insn
!= lastexit
; insn
= NEXT_INSN (insn
))
1197 switch (GET_CODE (insn
))
1200 copy
= emit_barrier_before (loop_start
);
1203 /* Only copy line-number notes. */
1204 if (NOTE_LINE_NUMBER (insn
) >= 0)
1206 copy
= emit_note_before (NOTE_LINE_NUMBER (insn
), loop_start
);
1207 NOTE_SOURCE_FILE (copy
) = NOTE_SOURCE_FILE (insn
);
1212 copy
= emit_insn_before (copy_insn (PATTERN (insn
)), loop_start
);
1214 replace_regs (PATTERN (copy
), reg_map
, max_reg
, 1);
1216 mark_jump_label (PATTERN (copy
), copy
, 0, 0);
1218 /* Copy all REG_NOTES except REG_LABEL since mark_jump_label will
1220 for (link
= REG_NOTES (insn
); link
; link
= XEXP (link
, 1))
1221 if (REG_NOTE_KIND (link
) != REG_LABEL
)
1223 if (GET_CODE (link
) == EXPR_LIST
)
1225 = copy_insn_1 (gen_rtx_EXPR_LIST (REG_NOTE_KIND (link
),
1230 = copy_insn_1 (gen_rtx_INSN_LIST (REG_NOTE_KIND (link
),
1235 if (reg_map
&& REG_NOTES (copy
))
1236 replace_regs (REG_NOTES (copy
), reg_map
, max_reg
, 1);
1240 copy
= emit_jump_insn_before (copy_insn (PATTERN (insn
)),
1243 replace_regs (PATTERN (copy
), reg_map
, max_reg
, 1);
1244 mark_jump_label (PATTERN (copy
), copy
, 0, 0);
1245 if (REG_NOTES (insn
))
1247 REG_NOTES (copy
) = copy_insn_1 (REG_NOTES (insn
));
1249 replace_regs (REG_NOTES (copy
), reg_map
, max_reg
, 1);
1252 /* Predict conditional jump that do make loop looping as taken.
1253 Other jumps are probably exit conditions, so predict
1255 if (any_condjump_p (copy
))
1257 rtx label
= JUMP_LABEL (copy
);
1260 if (PREV_INSN (label
)
1261 && GET_CODE (PREV_INSN (label
)) == NOTE
1262 && (NOTE_LINE_NUMBER (PREV_INSN (label
))
1263 == NOTE_INSN_LOOP_CONT
))
1264 predict_insn_def (copy
, PRED_LOOP_HEADER
, TAKEN
);
1266 predict_insn_def (copy
, PRED_LOOP_HEADER
, NOT_TAKEN
);
1269 /* If this is a simple jump, add it to the jump chain. */
1271 if (INSN_UID (copy
) < max_jump_chain
&& JUMP_LABEL (copy
)
1272 && simplejump_p (copy
))
1274 jump_chain
[INSN_UID (copy
)]
1275 = jump_chain
[INSN_UID (JUMP_LABEL (copy
))];
1276 jump_chain
[INSN_UID (JUMP_LABEL (copy
))] = copy
;
1284 /* Record the first insn we copied. We need it so that we can
1285 scan the copied insns for new pseudo registers. */
1290 /* Now clean up by emitting a jump to the end label and deleting the jump
1291 at the start of the loop. */
1292 if (! copy
|| GET_CODE (copy
) != BARRIER
)
1294 copy
= emit_jump_insn_before (gen_jump (get_label_after (insn
)),
1297 /* Record the first insn we copied. We need it so that we can
1298 scan the copied insns for new pseudo registers. This may not
1299 be strictly necessary since we should have copied at least one
1300 insn above. But I am going to be safe. */
1304 mark_jump_label (PATTERN (copy
), copy
, 0, 0);
1305 if (INSN_UID (copy
) < max_jump_chain
1306 && INSN_UID (JUMP_LABEL (copy
)) < max_jump_chain
)
1308 jump_chain
[INSN_UID (copy
)]
1309 = jump_chain
[INSN_UID (JUMP_LABEL (copy
))];
1310 jump_chain
[INSN_UID (JUMP_LABEL (copy
))] = copy
;
1312 emit_barrier_before (loop_start
);
1315 /* Now scan from the first insn we copied to the last insn we copied
1316 (copy) for new pseudo registers. Do this after the code to jump to
1317 the end label since that might create a new pseudo too. */
1318 reg_scan_update (first_copy
, copy
, max_reg
);
1320 /* Mark the exit code as the virtual top of the converted loop. */
1321 emit_note_before (NOTE_INSN_LOOP_VTOP
, exitcode
);
1323 delete_insn (next_nonnote_insn (loop_start
));
1332 /* Move all block-beg, block-end, loop-beg, loop-cont, loop-vtop, loop-end,
1333 notes between START and END out before START. Assume that END is not
1334 such a note. START may be such a note. Returns the value of the new
1335 starting insn, which may be different if the original start was such a
1339 squeeze_notes (start
, end
)
1345 for (insn
= start
; insn
!= end
; insn
= next
)
1347 next
= NEXT_INSN (insn
);
1348 if (GET_CODE (insn
) == NOTE
1349 && (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
1350 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
1351 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_LOOP_BEG
1352 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_LOOP_END
1353 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_LOOP_CONT
1354 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_LOOP_VTOP
))
1360 rtx prev
= PREV_INSN (insn
);
1361 PREV_INSN (insn
) = PREV_INSN (start
);
1362 NEXT_INSN (insn
) = start
;
1363 NEXT_INSN (PREV_INSN (insn
)) = insn
;
1364 PREV_INSN (NEXT_INSN (insn
)) = insn
;
1365 NEXT_INSN (prev
) = next
;
1366 PREV_INSN (next
) = prev
;
1374 /* Compare the instructions before insn E1 with those before E2
1375 to find an opportunity for cross jumping.
1376 (This means detecting identical sequences of insns followed by
1377 jumps to the same place, or followed by a label and a jump
1378 to that label, and replacing one with a jump to the other.)
1380 Assume E1 is a jump that jumps to label E2
1381 (that is not always true but it might as well be).
1382 Find the longest possible equivalent sequences
1383 and store the first insns of those sequences into *F1 and *F2.
1384 Store zero there if no equivalent preceding instructions are found.
1386 We give up if we find a label in stream 1.
1387 Actually we could transfer that label into stream 2. */
1390 find_cross_jump (e1
, e2
, minimum
, f1
, f2
)
1395 register rtx i1
= e1
, i2
= e2
;
1396 register rtx p1
, p2
;
1399 rtx last1
= 0, last2
= 0;
1400 rtx afterlast1
= 0, afterlast2
= 0;
1407 i1
= prev_nonnote_insn (i1
);
1409 i2
= PREV_INSN (i2
);
1410 while (i2
&& (GET_CODE (i2
) == NOTE
|| GET_CODE (i2
) == CODE_LABEL
))
1411 i2
= PREV_INSN (i2
);
1416 /* Don't allow the range of insns preceding E1 or E2
1417 to include the other (E2 or E1). */
1418 if (i2
== e1
|| i1
== e2
)
1421 /* If we will get to this code by jumping, those jumps will be
1422 tensioned to go directly to the new label (before I2),
1423 so this cross-jumping won't cost extra. So reduce the minimum. */
1424 if (GET_CODE (i1
) == CODE_LABEL
)
1430 if (i2
== 0 || GET_CODE (i1
) != GET_CODE (i2
))
1436 /* If this is a CALL_INSN, compare register usage information.
1437 If we don't check this on stack register machines, the two
1438 CALL_INSNs might be merged leaving reg-stack.c with mismatching
1439 numbers of stack registers in the same basic block.
1440 If we don't check this on machines with delay slots, a delay slot may
1441 be filled that clobbers a parameter expected by the subroutine.
1443 ??? We take the simple route for now and assume that if they're
1444 equal, they were constructed identically. */
1446 if (GET_CODE (i1
) == CALL_INSN
1447 && ! rtx_equal_p (CALL_INSN_FUNCTION_USAGE (i1
),
1448 CALL_INSN_FUNCTION_USAGE (i2
)))
1452 /* If cross_jump_death_matters is not 0, the insn's mode
1453 indicates whether or not the insn contains any stack-like
1456 if (!lose
&& cross_jump_death_matters
&& stack_regs_mentioned (i1
))
1458 /* If register stack conversion has already been done, then
1459 death notes must also be compared before it is certain that
1460 the two instruction streams match. */
1463 HARD_REG_SET i1_regset
, i2_regset
;
1465 CLEAR_HARD_REG_SET (i1_regset
);
1466 CLEAR_HARD_REG_SET (i2_regset
);
1468 for (note
= REG_NOTES (i1
); note
; note
= XEXP (note
, 1))
1469 if (REG_NOTE_KIND (note
) == REG_DEAD
1470 && STACK_REG_P (XEXP (note
, 0)))
1471 SET_HARD_REG_BIT (i1_regset
, REGNO (XEXP (note
, 0)));
1473 for (note
= REG_NOTES (i2
); note
; note
= XEXP (note
, 1))
1474 if (REG_NOTE_KIND (note
) == REG_DEAD
1475 && STACK_REG_P (XEXP (note
, 0)))
1476 SET_HARD_REG_BIT (i2_regset
, REGNO (XEXP (note
, 0)));
1478 GO_IF_HARD_REG_EQUAL (i1_regset
, i2_regset
, done
);
1487 /* Don't allow old-style asm or volatile extended asms to be accepted
1488 for cross jumping purposes. It is conceptually correct to allow
1489 them, since cross-jumping preserves the dynamic instruction order
1490 even though it is changing the static instruction order. However,
1491 if an asm is being used to emit an assembler pseudo-op, such as
1492 the MIPS `.set reorder' pseudo-op, then the static instruction order
1493 matters and it must be preserved. */
1494 if (GET_CODE (p1
) == ASM_INPUT
|| GET_CODE (p2
) == ASM_INPUT
1495 || (GET_CODE (p1
) == ASM_OPERANDS
&& MEM_VOLATILE_P (p1
))
1496 || (GET_CODE (p2
) == ASM_OPERANDS
&& MEM_VOLATILE_P (p2
)))
1499 if (lose
|| GET_CODE (p1
) != GET_CODE (p2
)
1500 || ! rtx_renumbered_equal_p (p1
, p2
))
1502 /* The following code helps take care of G++ cleanups. */
1506 if (!lose
&& GET_CODE (p1
) == GET_CODE (p2
)
1507 && ((equiv1
= find_reg_note (i1
, REG_EQUAL
, NULL_RTX
)) != 0
1508 || (equiv1
= find_reg_note (i1
, REG_EQUIV
, NULL_RTX
)) != 0)
1509 && ((equiv2
= find_reg_note (i2
, REG_EQUAL
, NULL_RTX
)) != 0
1510 || (equiv2
= find_reg_note (i2
, REG_EQUIV
, NULL_RTX
)) != 0)
1511 /* If the equivalences are not to a constant, they may
1512 reference pseudos that no longer exist, so we can't
1514 && CONSTANT_P (XEXP (equiv1
, 0))
1515 && rtx_equal_p (XEXP (equiv1
, 0), XEXP (equiv2
, 0)))
1517 rtx s1
= single_set (i1
);
1518 rtx s2
= single_set (i2
);
1519 if (s1
!= 0 && s2
!= 0
1520 && rtx_renumbered_equal_p (SET_DEST (s1
), SET_DEST (s2
)))
1522 validate_change (i1
, &SET_SRC (s1
), XEXP (equiv1
, 0), 1);
1523 validate_change (i2
, &SET_SRC (s2
), XEXP (equiv2
, 0), 1);
1524 if (! rtx_renumbered_equal_p (p1
, p2
))
1526 else if (apply_change_group ())
1531 /* Insns fail to match; cross jumping is limited to the following
1535 /* Don't allow the insn after a compare to be shared by
1536 cross-jumping unless the compare is also shared.
1537 Here, if either of these non-matching insns is a compare,
1538 exclude the following insn from possible cross-jumping. */
1539 if (sets_cc0_p (p1
) || sets_cc0_p (p2
))
1540 last1
= afterlast1
, last2
= afterlast2
, ++minimum
;
1543 /* If cross-jumping here will feed a jump-around-jump
1544 optimization, this jump won't cost extra, so reduce
1546 if (GET_CODE (i1
) == JUMP_INSN
1548 && prev_real_insn (JUMP_LABEL (i1
)) == e1
)
1554 if (GET_CODE (p1
) != USE
&& GET_CODE (p1
) != CLOBBER
)
1556 /* Ok, this insn is potentially includable in a cross-jump here. */
1557 afterlast1
= last1
, afterlast2
= last2
;
1558 last1
= i1
, last2
= i2
, --minimum
;
1562 if (minimum
<= 0 && last1
!= 0 && last1
!= e1
)
1563 *f1
= last1
, *f2
= last2
;
1567 do_cross_jump (insn
, newjpos
, newlpos
)
1568 rtx insn
, newjpos
, newlpos
;
1570 /* Find an existing label at this point
1571 or make a new one if there is none. */
1572 register rtx label
= get_label_before (newlpos
);
1574 /* Make the same jump insn jump to the new point. */
1575 if (GET_CODE (PATTERN (insn
)) == RETURN
)
1577 /* Remove from jump chain of returns. */
1578 delete_from_jump_chain (insn
);
1579 /* Change the insn. */
1580 PATTERN (insn
) = gen_jump (label
);
1581 INSN_CODE (insn
) = -1;
1582 JUMP_LABEL (insn
) = label
;
1583 LABEL_NUSES (label
)++;
1584 /* Add to new the jump chain. */
1585 if (INSN_UID (label
) < max_jump_chain
1586 && INSN_UID (insn
) < max_jump_chain
)
1588 jump_chain
[INSN_UID (insn
)] = jump_chain
[INSN_UID (label
)];
1589 jump_chain
[INSN_UID (label
)] = insn
;
1593 redirect_jump (insn
, label
, 1);
1595 /* Delete the matching insns before the jump. Also, remove any REG_EQUAL
1596 or REG_EQUIV note in the NEWLPOS stream that isn't also present in
1597 the NEWJPOS stream. */
1599 while (newjpos
!= insn
)
1603 for (lnote
= REG_NOTES (newlpos
); lnote
; lnote
= XEXP (lnote
, 1))
1604 if ((REG_NOTE_KIND (lnote
) == REG_EQUAL
1605 || REG_NOTE_KIND (lnote
) == REG_EQUIV
)
1606 && ! find_reg_note (newjpos
, REG_EQUAL
, XEXP (lnote
, 0))
1607 && ! find_reg_note (newjpos
, REG_EQUIV
, XEXP (lnote
, 0)))
1608 remove_note (newlpos
, lnote
);
1610 delete_insn (newjpos
);
1611 newjpos
= next_real_insn (newjpos
);
1612 newlpos
= next_real_insn (newlpos
);
1616 /* Return the label before INSN, or put a new label there. */
1619 get_label_before (insn
)
1624 /* Find an existing label at this point
1625 or make a new one if there is none. */
1626 label
= prev_nonnote_insn (insn
);
1628 if (label
== 0 || GET_CODE (label
) != CODE_LABEL
)
1630 rtx prev
= PREV_INSN (insn
);
1632 label
= gen_label_rtx ();
1633 emit_label_after (label
, prev
);
1634 LABEL_NUSES (label
) = 0;
1639 /* Return the label after INSN, or put a new label there. */
1642 get_label_after (insn
)
1647 /* Find an existing label at this point
1648 or make a new one if there is none. */
1649 label
= next_nonnote_insn (insn
);
1651 if (label
== 0 || GET_CODE (label
) != CODE_LABEL
)
1653 label
= gen_label_rtx ();
1654 emit_label_after (label
, insn
);
1655 LABEL_NUSES (label
) = 0;
1660 /* Return 1 if INSN is a jump that jumps to right after TARGET
1661 only on the condition that TARGET itself would drop through.
1662 Assumes that TARGET is a conditional jump. */
1665 jump_back_p (insn
, target
)
1669 enum rtx_code codei
, codet
;
1672 if (! any_condjump_p (insn
)
1673 || any_uncondjump_p (target
)
1674 || target
!= prev_real_insn (JUMP_LABEL (insn
)))
1676 set
= pc_set (insn
);
1677 tset
= pc_set (target
);
1679 cinsn
= XEXP (SET_SRC (set
), 0);
1680 ctarget
= XEXP (SET_SRC (tset
), 0);
1682 codei
= GET_CODE (cinsn
);
1683 codet
= GET_CODE (ctarget
);
1685 if (XEXP (SET_SRC (set
), 1) == pc_rtx
)
1687 codei
= reversed_comparison_code (cinsn
, insn
);
1688 if (codei
== UNKNOWN
)
1692 if (XEXP (SET_SRC (tset
), 2) == pc_rtx
)
1694 codet
= reversed_comparison_code (ctarget
, target
);
1695 if (codei
== UNKNOWN
)
1699 return (codei
== codet
1700 && rtx_renumbered_equal_p (XEXP (cinsn
, 0), XEXP (ctarget
, 0))
1701 && rtx_renumbered_equal_p (XEXP (cinsn
, 1), XEXP (ctarget
, 1)));
1704 /* Given a comparison (CODE ARG0 ARG1), inside a insn, INSN, return an code
1705 of reversed comparison if it is possible to do so. Otherwise return UNKNOWN.
1706 UNKNOWN may be returned in case we are having CC_MODE compare and we don't
1707 know whether it's source is floating point or integer comparison. Machine
1708 description should define REVERSIBLE_CC_MODE and REVERSE_CONDITION macros
1709 to help this function avoid overhead in these cases. */
1711 reversed_comparison_code_parts (code
, arg0
, arg1
, insn
)
1712 rtx insn
, arg0
, arg1
;
1715 enum machine_mode mode
;
1717 /* If this is not actually a comparison, we can't reverse it. */
1718 if (GET_RTX_CLASS (code
) != '<')
1721 mode
= GET_MODE (arg0
);
1722 if (mode
== VOIDmode
)
1723 mode
= GET_MODE (arg1
);
1725 /* First see if machine description supply us way to reverse the comparison.
1726 Give it priority over everything else to allow machine description to do
1728 #ifdef REVERSIBLE_CC_MODE
1729 if (GET_MODE_CLASS (mode
) == MODE_CC
1730 && REVERSIBLE_CC_MODE (mode
))
1732 #ifdef REVERSE_CONDITION
1733 return REVERSE_CONDITION (code
, mode
);
1735 return reverse_condition (code
);
1739 /* Try few special cases based on the comparison code. */
1748 /* It is always safe to reverse EQ and NE, even for the floating
1749 point. Similary the unsigned comparisons are never used for
1750 floating point so we can reverse them in the default way. */
1751 return reverse_condition (code
);
1756 /* In case we already see unordered comparison, we can be sure to
1757 be dealing with floating point so we don't need any more tests. */
1758 return reverse_condition_maybe_unordered (code
);
1763 /* We don't have safe way to reverse these yet. */
1769 /* In case we give up IEEE compatibility, all comparisons are reversible. */
1770 if (TARGET_FLOAT_FORMAT
!= IEEE_FLOAT_FORMAT
1771 || flag_unsafe_math_optimizations
)
1772 return reverse_condition (code
);
1774 if (GET_MODE_CLASS (mode
) == MODE_CC
1781 /* Try to search for the comparison to determine the real mode.
1782 This code is expensive, but with sane machine description it
1783 will be never used, since REVERSIBLE_CC_MODE will return true
1788 for (prev
= prev_nonnote_insn (insn
);
1789 prev
!= 0 && GET_CODE (prev
) != CODE_LABEL
;
1790 prev
= prev_nonnote_insn (prev
))
1792 rtx set
= set_of (arg0
, prev
);
1793 if (set
&& GET_CODE (set
) == SET
1794 && rtx_equal_p (SET_DEST (set
), arg0
))
1796 rtx src
= SET_SRC (set
);
1798 if (GET_CODE (src
) == COMPARE
)
1800 rtx comparison
= src
;
1801 arg0
= XEXP (src
, 0);
1802 mode
= GET_MODE (arg0
);
1803 if (mode
== VOIDmode
)
1804 mode
= GET_MODE (XEXP (comparison
, 1));
1807 /* We can get past reg-reg moves. This may be usefull for model
1808 of i387 comparisons that first move flag registers around. */
1815 /* If register is clobbered in some ununderstandable way,
1822 /* An integer condition. */
1823 if (GET_CODE (arg0
) == CONST_INT
1824 || (GET_MODE (arg0
) != VOIDmode
1825 && GET_MODE_CLASS (mode
) != MODE_CC
1826 && ! FLOAT_MODE_P (mode
)))
1827 return reverse_condition (code
);
1832 /* An wrapper around the previous function to take COMPARISON as rtx
1833 expression. This simplifies many callers. */
1835 reversed_comparison_code (comparison
, insn
)
1836 rtx comparison
, insn
;
1838 if (GET_RTX_CLASS (GET_CODE (comparison
)) != '<')
1840 return reversed_comparison_code_parts (GET_CODE (comparison
),
1841 XEXP (comparison
, 0),
1842 XEXP (comparison
, 1), insn
);
1845 /* Given an rtx-code for a comparison, return the code for the negated
1846 comparison. If no such code exists, return UNKNOWN.
1848 WATCH OUT! reverse_condition is not safe to use on a jump that might
1849 be acting on the results of an IEEE floating point comparison, because
1850 of the special treatment of non-signaling nans in comparisons.
1851 Use reversed_comparison_code instead. */
1854 reverse_condition (code
)
1897 /* Similar, but we're allowed to generate unordered comparisons, which
1898 makes it safe for IEEE floating-point. Of course, we have to recognize
1899 that the target will support them too... */
1902 reverse_condition_maybe_unordered (code
)
1905 /* Non-IEEE formats don't have unordered conditions. */
1906 if (TARGET_FLOAT_FORMAT
!= IEEE_FLOAT_FORMAT
)
1907 return reverse_condition (code
);
1945 /* Similar, but return the code when two operands of a comparison are swapped.
1946 This IS safe for IEEE floating-point. */
1949 swap_condition (code
)
1992 /* Given a comparison CODE, return the corresponding unsigned comparison.
1993 If CODE is an equality comparison or already an unsigned comparison,
1994 CODE is returned. */
1997 unsigned_condition (code
)
2024 /* Similarly, return the signed version of a comparison. */
2027 signed_condition (code
)
2054 /* Return non-zero if CODE1 is more strict than CODE2, i.e., if the
2055 truth of CODE1 implies the truth of CODE2. */
2058 comparison_dominates_p (code1
, code2
)
2059 enum rtx_code code1
, code2
;
2061 /* UNKNOWN comparison codes can happen as a result of trying to revert
2063 They can't match anything, so we have to reject them here. */
2064 if (code1
== UNKNOWN
|| code2
== UNKNOWN
)
2073 if (code2
== UNLE
|| code2
== UNGE
)
2078 if (code2
== LE
|| code2
== LEU
|| code2
== GE
|| code2
== GEU
2079 || code2
== ORDERED
)
2084 if (code2
== UNLE
|| code2
== NE
)
2089 if (code2
== LE
|| code2
== NE
|| code2
== ORDERED
|| code2
== LTGT
)
2094 if (code2
== UNGE
|| code2
== NE
)
2099 if (code2
== GE
|| code2
== NE
|| code2
== ORDERED
|| code2
== LTGT
)
2105 if (code2
== ORDERED
)
2110 if (code2
== NE
|| code2
== ORDERED
)
2115 if (code2
== LEU
|| code2
== NE
)
2120 if (code2
== GEU
|| code2
== NE
)
2125 if (code2
== NE
|| code2
== UNEQ
|| code2
== UNLE
|| code2
== UNLT
2126 || code2
== UNGE
|| code2
== UNGT
)
2137 /* Return 1 if INSN is an unconditional jump and nothing else. */
2143 return (GET_CODE (insn
) == JUMP_INSN
2144 && GET_CODE (PATTERN (insn
)) == SET
2145 && GET_CODE (SET_DEST (PATTERN (insn
))) == PC
2146 && GET_CODE (SET_SRC (PATTERN (insn
))) == LABEL_REF
);
2149 /* Return nonzero if INSN is a (possibly) conditional jump
2152 Use this function is deprecated, since we need to support combined
2153 branch and compare insns. Use any_condjump_p instead whenever possible. */
2159 register rtx x
= PATTERN (insn
);
2161 if (GET_CODE (x
) != SET
2162 || GET_CODE (SET_DEST (x
)) != PC
)
2166 if (GET_CODE (x
) == LABEL_REF
)
2169 return (GET_CODE (x
) == IF_THEN_ELSE
2170 && ((GET_CODE (XEXP (x
, 2)) == PC
2171 && (GET_CODE (XEXP (x
, 1)) == LABEL_REF
2172 || GET_CODE (XEXP (x
, 1)) == RETURN
))
2173 || (GET_CODE (XEXP (x
, 1)) == PC
2174 && (GET_CODE (XEXP (x
, 2)) == LABEL_REF
2175 || GET_CODE (XEXP (x
, 2)) == RETURN
))));
2180 /* Return nonzero if INSN is a (possibly) conditional jump inside a
2183 Use this function is deprecated, since we need to support combined
2184 branch and compare insns. Use any_condjump_p instead whenever possible. */
2187 condjump_in_parallel_p (insn
)
2190 register rtx x
= PATTERN (insn
);
2192 if (GET_CODE (x
) != PARALLEL
)
2195 x
= XVECEXP (x
, 0, 0);
2197 if (GET_CODE (x
) != SET
)
2199 if (GET_CODE (SET_DEST (x
)) != PC
)
2201 if (GET_CODE (SET_SRC (x
)) == LABEL_REF
)
2203 if (GET_CODE (SET_SRC (x
)) != IF_THEN_ELSE
)
2205 if (XEXP (SET_SRC (x
), 2) == pc_rtx
2206 && (GET_CODE (XEXP (SET_SRC (x
), 1)) == LABEL_REF
2207 || GET_CODE (XEXP (SET_SRC (x
), 1)) == RETURN
))
2209 if (XEXP (SET_SRC (x
), 1) == pc_rtx
2210 && (GET_CODE (XEXP (SET_SRC (x
), 2)) == LABEL_REF
2211 || GET_CODE (XEXP (SET_SRC (x
), 2)) == RETURN
))
2216 /* Return set of PC, otherwise NULL. */
2223 if (GET_CODE (insn
) != JUMP_INSN
)
2225 pat
= PATTERN (insn
);
2227 /* The set is allowed to appear either as the insn pattern or
2228 the first set in a PARALLEL. */
2229 if (GET_CODE (pat
) == PARALLEL
)
2230 pat
= XVECEXP (pat
, 0, 0);
2231 if (GET_CODE (pat
) == SET
&& GET_CODE (SET_DEST (pat
)) == PC
)
2237 /* Return true when insn is an unconditional direct jump,
2238 possibly bundled inside a PARALLEL. */
2241 any_uncondjump_p (insn
)
2244 rtx x
= pc_set (insn
);
2247 if (GET_CODE (SET_SRC (x
)) != LABEL_REF
)
2252 /* Return true when insn is a conditional jump. This function works for
2253 instructions containing PC sets in PARALLELs. The instruction may have
2254 various other effects so before removing the jump you must verify
2257 Note that unlike condjump_p it returns false for unconditional jumps. */
2260 any_condjump_p (insn
)
2263 rtx x
= pc_set (insn
);
2268 if (GET_CODE (SET_SRC (x
)) != IF_THEN_ELSE
)
2271 a
= GET_CODE (XEXP (SET_SRC (x
), 1));
2272 b
= GET_CODE (XEXP (SET_SRC (x
), 2));
2274 return ((b
== PC
&& (a
== LABEL_REF
|| a
== RETURN
))
2275 || (a
== PC
&& (b
== LABEL_REF
|| b
== RETURN
)));
2278 /* Return the label of a conditional jump. */
2281 condjump_label (insn
)
2284 rtx x
= pc_set (insn
);
2289 if (GET_CODE (x
) == LABEL_REF
)
2291 if (GET_CODE (x
) != IF_THEN_ELSE
)
2293 if (XEXP (x
, 2) == pc_rtx
&& GET_CODE (XEXP (x
, 1)) == LABEL_REF
)
2295 if (XEXP (x
, 1) == pc_rtx
&& GET_CODE (XEXP (x
, 2)) == LABEL_REF
)
2300 /* Return true if INSN is a (possibly conditional) return insn. */
2303 returnjump_p_1 (loc
, data
)
2305 void *data ATTRIBUTE_UNUSED
;
2308 return x
&& GET_CODE (x
) == RETURN
;
2315 if (GET_CODE (insn
) != JUMP_INSN
)
2317 return for_each_rtx (&PATTERN (insn
), returnjump_p_1
, NULL
);
2320 /* Return true if INSN is a jump that only transfers control and
2329 if (GET_CODE (insn
) != JUMP_INSN
)
2332 set
= single_set (insn
);
2335 if (GET_CODE (SET_DEST (set
)) != PC
)
2337 if (side_effects_p (SET_SRC (set
)))
2345 /* Return 1 if X is an RTX that does nothing but set the condition codes
2346 and CLOBBER or USE registers.
2347 Return -1 if X does explicitly set the condition codes,
2348 but also does other things. */
2352 rtx x ATTRIBUTE_UNUSED
;
2354 if (GET_CODE (x
) == SET
&& SET_DEST (x
) == cc0_rtx
)
2356 if (GET_CODE (x
) == PARALLEL
)
2360 int other_things
= 0;
2361 for (i
= XVECLEN (x
, 0) - 1; i
>= 0; i
--)
2363 if (GET_CODE (XVECEXP (x
, 0, i
)) == SET
2364 && SET_DEST (XVECEXP (x
, 0, i
)) == cc0_rtx
)
2366 else if (GET_CODE (XVECEXP (x
, 0, i
)) == SET
)
2369 return ! sets_cc0
? 0 : other_things
? -1 : 1;
2375 /* Follow any unconditional jump at LABEL;
2376 return the ultimate label reached by any such chain of jumps.
2377 If LABEL is not followed by a jump, return LABEL.
2378 If the chain loops or we can't find end, return LABEL,
2379 since that tells caller to avoid changing the insn.
2381 If RELOAD_COMPLETED is 0, we do not chain across a NOTE_INSN_LOOP_BEG or
2382 a USE or CLOBBER. */
2385 follow_jumps (label
)
2390 register rtx value
= label
;
2395 && (insn
= next_active_insn (value
)) != 0
2396 && GET_CODE (insn
) == JUMP_INSN
2397 && ((JUMP_LABEL (insn
) != 0 && any_uncondjump_p (insn
)
2398 && onlyjump_p (insn
))
2399 || GET_CODE (PATTERN (insn
)) == RETURN
)
2400 && (next
= NEXT_INSN (insn
))
2401 && GET_CODE (next
) == BARRIER
);
2404 /* Don't chain through the insn that jumps into a loop
2405 from outside the loop,
2406 since that would create multiple loop entry jumps
2407 and prevent loop optimization. */
2409 if (!reload_completed
)
2410 for (tem
= value
; tem
!= insn
; tem
= NEXT_INSN (tem
))
2411 if (GET_CODE (tem
) == NOTE
2412 && (NOTE_LINE_NUMBER (tem
) == NOTE_INSN_LOOP_BEG
2413 /* ??? Optional. Disables some optimizations, but makes
2414 gcov output more accurate with -O. */
2415 || (flag_test_coverage
&& NOTE_LINE_NUMBER (tem
) > 0)))
2418 /* If we have found a cycle, make the insn jump to itself. */
2419 if (JUMP_LABEL (insn
) == label
)
2422 tem
= next_active_insn (JUMP_LABEL (insn
));
2423 if (tem
&& (GET_CODE (PATTERN (tem
)) == ADDR_VEC
2424 || GET_CODE (PATTERN (tem
)) == ADDR_DIFF_VEC
))
2427 value
= JUMP_LABEL (insn
);
2434 /* Assuming that field IDX of X is a vector of label_refs,
2435 replace each of them by the ultimate label reached by it.
2436 Return nonzero if a change is made.
2437 If IGNORE_LOOPS is 0, we do not chain across a NOTE_INSN_LOOP_BEG. */
2440 tension_vector_labels (x
, idx
)
2446 for (i
= XVECLEN (x
, idx
) - 1; i
>= 0; i
--)
2448 register rtx olabel
= XEXP (XVECEXP (x
, idx
, i
), 0);
2449 register rtx nlabel
= follow_jumps (olabel
);
2450 if (nlabel
&& nlabel
!= olabel
)
2452 XEXP (XVECEXP (x
, idx
, i
), 0) = nlabel
;
2453 ++LABEL_NUSES (nlabel
);
2454 if (--LABEL_NUSES (olabel
) == 0)
2455 delete_insn (olabel
);
2462 /* Find all CODE_LABELs referred to in X, and increment their use counts.
2463 If INSN is a JUMP_INSN and there is at least one CODE_LABEL referenced
2464 in INSN, then store one of them in JUMP_LABEL (INSN).
2465 If INSN is an INSN or a CALL_INSN and there is at least one CODE_LABEL
2466 referenced in INSN, add a REG_LABEL note containing that label to INSN.
2467 Also, when there are consecutive labels, canonicalize on the last of them.
2469 Note that two labels separated by a loop-beginning note
2470 must be kept distinct if we have not yet done loop-optimization,
2471 because the gap between them is where loop-optimize
2472 will want to move invariant code to. CROSS_JUMP tells us
2473 that loop-optimization is done with.
2475 Once reload has completed (CROSS_JUMP non-zero), we need not consider
2476 two labels distinct if they are separated by only USE or CLOBBER insns. */
2479 mark_jump_label (x
, insn
, cross_jump
, in_mem
)
2485 register RTX_CODE code
= GET_CODE (x
);
2487 register const char *fmt
;
2509 /* If this is a constant-pool reference, see if it is a label. */
2510 if (CONSTANT_POOL_ADDRESS_P (x
))
2511 mark_jump_label (get_pool_constant (x
), insn
, cross_jump
, in_mem
);
2516 rtx label
= XEXP (x
, 0);
2520 /* Ignore remaining references to unreachable labels that
2521 have been deleted. */
2522 if (GET_CODE (label
) == NOTE
2523 && NOTE_LINE_NUMBER (label
) == NOTE_INSN_DELETED_LABEL
)
2526 if (GET_CODE (label
) != CODE_LABEL
)
2529 /* Ignore references to labels of containing functions. */
2530 if (LABEL_REF_NONLOCAL_P (x
))
2533 /* If there are other labels following this one,
2534 replace it with the last of the consecutive labels. */
2535 for (next
= NEXT_INSN (label
); next
; next
= NEXT_INSN (next
))
2537 if (GET_CODE (next
) == CODE_LABEL
)
2539 else if (cross_jump
&& GET_CODE (next
) == INSN
2540 && (GET_CODE (PATTERN (next
)) == USE
2541 || GET_CODE (PATTERN (next
)) == CLOBBER
))
2543 else if (GET_CODE (next
) != NOTE
)
2545 else if (! cross_jump
2546 && (NOTE_LINE_NUMBER (next
) == NOTE_INSN_LOOP_BEG
2547 || NOTE_LINE_NUMBER (next
) == NOTE_INSN_FUNCTION_END
2548 /* ??? Optional. Disables some optimizations, but
2549 makes gcov output more accurate with -O. */
2550 || (flag_test_coverage
2551 && NOTE_LINE_NUMBER (next
) > 0)))
2555 XEXP (x
, 0) = label
;
2556 if (! insn
|| ! INSN_DELETED_P (insn
))
2557 ++LABEL_NUSES (label
);
2561 if (GET_CODE (insn
) == JUMP_INSN
)
2562 JUMP_LABEL (insn
) = label
;
2565 /* If we've changed the label, update notes accordingly. */
2566 if (label
!= olabel
)
2570 /* We may have a REG_LABEL note to indicate that this
2571 instruction uses the label. */
2572 note
= find_reg_note (insn
, REG_LABEL
, olabel
);
2574 XEXP (note
, 0) = label
;
2576 /* We may also have a REG_EQUAL note to indicate that
2577 a register is being set to the address of the
2579 note
= find_reg_note (insn
, REG_EQUAL
, NULL_RTX
);
2581 && GET_CODE (XEXP (note
, 0)) == LABEL_REF
2582 && XEXP (XEXP (note
, 0), 0) == olabel
)
2583 XEXP (XEXP (note
, 0), 0) = label
;
2586 /* Add a REG_LABEL note for LABEL unless there already
2587 is one. All uses of a label, except for labels
2588 that are the targets of jumps, must have a
2590 if (! find_reg_note (insn
, REG_LABEL
, label
))
2591 REG_NOTES (insn
) = gen_rtx_INSN_LIST (REG_LABEL
, label
,
2598 /* Do walk the labels in a vector, but not the first operand of an
2599 ADDR_DIFF_VEC. Don't set the JUMP_LABEL of a vector. */
2602 if (! INSN_DELETED_P (insn
))
2604 int eltnum
= code
== ADDR_DIFF_VEC
? 1 : 0;
2606 for (i
= 0; i
< XVECLEN (x
, eltnum
); i
++)
2607 mark_jump_label (XVECEXP (x
, eltnum
, i
), NULL_RTX
,
2608 cross_jump
, in_mem
);
2616 fmt
= GET_RTX_FORMAT (code
);
2617 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
2620 mark_jump_label (XEXP (x
, i
), insn
, cross_jump
, in_mem
);
2621 else if (fmt
[i
] == 'E')
2624 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
2625 mark_jump_label (XVECEXP (x
, i
, j
), insn
, cross_jump
, in_mem
);
2630 /* If all INSN does is set the pc, delete it,
2631 and delete the insn that set the condition codes for it
2632 if that's what the previous thing was. */
2638 register rtx set
= single_set (insn
);
2640 if (set
&& GET_CODE (SET_DEST (set
)) == PC
)
2641 delete_computation (insn
);
2644 /* Verify INSN is a BARRIER and delete it. */
2647 delete_barrier (insn
)
2650 if (GET_CODE (insn
) != BARRIER
)
2656 /* Recursively delete prior insns that compute the value (used only by INSN
2657 which the caller is deleting) stored in the register mentioned by NOTE
2658 which is a REG_DEAD note associated with INSN. */
2661 delete_prior_computation (note
, insn
)
2666 rtx reg
= XEXP (note
, 0);
2668 for (our_prev
= prev_nonnote_insn (insn
);
2669 our_prev
&& (GET_CODE (our_prev
) == INSN
2670 || GET_CODE (our_prev
) == CALL_INSN
);
2671 our_prev
= prev_nonnote_insn (our_prev
))
2673 rtx pat
= PATTERN (our_prev
);
2675 /* If we reach a CALL which is not calling a const function
2676 or the callee pops the arguments, then give up. */
2677 if (GET_CODE (our_prev
) == CALL_INSN
2678 && (! CONST_CALL_P (our_prev
)
2679 || GET_CODE (pat
) != SET
|| GET_CODE (SET_SRC (pat
)) != CALL
))
2682 /* If we reach a SEQUENCE, it is too complex to try to
2683 do anything with it, so give up. */
2684 if (GET_CODE (pat
) == SEQUENCE
)
2687 if (GET_CODE (pat
) == USE
2688 && GET_CODE (XEXP (pat
, 0)) == INSN
)
2689 /* reorg creates USEs that look like this. We leave them
2690 alone because reorg needs them for its own purposes. */
2693 if (reg_set_p (reg
, pat
))
2695 if (side_effects_p (pat
) && GET_CODE (our_prev
) != CALL_INSN
)
2698 if (GET_CODE (pat
) == PARALLEL
)
2700 /* If we find a SET of something else, we can't
2705 for (i
= 0; i
< XVECLEN (pat
, 0); i
++)
2707 rtx part
= XVECEXP (pat
, 0, i
);
2709 if (GET_CODE (part
) == SET
2710 && SET_DEST (part
) != reg
)
2714 if (i
== XVECLEN (pat
, 0))
2715 delete_computation (our_prev
);
2717 else if (GET_CODE (pat
) == SET
2718 && GET_CODE (SET_DEST (pat
)) == REG
)
2720 int dest_regno
= REGNO (SET_DEST (pat
));
2723 + (dest_regno
< FIRST_PSEUDO_REGISTER
2724 ? HARD_REGNO_NREGS (dest_regno
,
2725 GET_MODE (SET_DEST (pat
))) : 1));
2726 int regno
= REGNO (reg
);
2729 + (regno
< FIRST_PSEUDO_REGISTER
2730 ? HARD_REGNO_NREGS (regno
, GET_MODE (reg
)) : 1));
2732 if (dest_regno
>= regno
2733 && dest_endregno
<= endregno
)
2734 delete_computation (our_prev
);
2736 /* We may have a multi-word hard register and some, but not
2737 all, of the words of the register are needed in subsequent
2738 insns. Write REG_UNUSED notes for those parts that were not
2740 else if (dest_regno
<= regno
2741 && dest_endregno
>= endregno
)
2745 REG_NOTES (our_prev
)
2746 = gen_rtx_EXPR_LIST (REG_UNUSED
, reg
,
2747 REG_NOTES (our_prev
));
2749 for (i
= dest_regno
; i
< dest_endregno
; i
++)
2750 if (! find_regno_note (our_prev
, REG_UNUSED
, i
))
2753 if (i
== dest_endregno
)
2754 delete_computation (our_prev
);
2761 /* If PAT references the register that dies here, it is an
2762 additional use. Hence any prior SET isn't dead. However, this
2763 insn becomes the new place for the REG_DEAD note. */
2764 if (reg_overlap_mentioned_p (reg
, pat
))
2766 XEXP (note
, 1) = REG_NOTES (our_prev
);
2767 REG_NOTES (our_prev
) = note
;
2773 /* Delete INSN and recursively delete insns that compute values used only
2774 by INSN. This uses the REG_DEAD notes computed during flow analysis.
2775 If we are running before flow.c, we need do nothing since flow.c will
2776 delete dead code. We also can't know if the registers being used are
2777 dead or not at this point.
2779 Otherwise, look at all our REG_DEAD notes. If a previous insn does
2780 nothing other than set a register that dies in this insn, we can delete
2783 On machines with CC0, if CC0 is used in this insn, we may be able to
2784 delete the insn that set it. */
2787 delete_computation (insn
)
2793 if (reg_referenced_p (cc0_rtx
, PATTERN (insn
)))
2795 rtx prev
= prev_nonnote_insn (insn
);
2796 /* We assume that at this stage
2797 CC's are always set explicitly
2798 and always immediately before the jump that
2799 will use them. So if the previous insn
2800 exists to set the CC's, delete it
2801 (unless it performs auto-increments, etc.). */
2802 if (prev
&& GET_CODE (prev
) == INSN
2803 && sets_cc0_p (PATTERN (prev
)))
2805 if (sets_cc0_p (PATTERN (prev
)) > 0
2806 && ! side_effects_p (PATTERN (prev
)))
2807 delete_computation (prev
);
2809 /* Otherwise, show that cc0 won't be used. */
2810 REG_NOTES (prev
) = gen_rtx_EXPR_LIST (REG_UNUSED
,
2811 cc0_rtx
, REG_NOTES (prev
));
2816 for (note
= REG_NOTES (insn
); note
; note
= next
)
2818 next
= XEXP (note
, 1);
2820 if (REG_NOTE_KIND (note
) != REG_DEAD
2821 /* Verify that the REG_NOTE is legitimate. */
2822 || GET_CODE (XEXP (note
, 0)) != REG
)
2825 delete_prior_computation (note
, insn
);
2831 /* Delete insn INSN from the chain of insns and update label ref counts.
2832 May delete some following insns as a consequence; may even delete
2833 a label elsewhere and insns that follow it.
2835 Returns the first insn after INSN that was not deleted. */
2841 register rtx next
= NEXT_INSN (insn
);
2842 register rtx prev
= PREV_INSN (insn
);
2843 register int was_code_label
= (GET_CODE (insn
) == CODE_LABEL
);
2844 register int dont_really_delete
= 0;
2847 while (next
&& INSN_DELETED_P (next
))
2848 next
= NEXT_INSN (next
);
2850 /* This insn is already deleted => return first following nondeleted. */
2851 if (INSN_DELETED_P (insn
))
2855 remove_node_from_expr_list (insn
, &nonlocal_goto_handler_labels
);
2857 /* Don't delete user-declared labels. When optimizing, convert them
2858 to special NOTEs instead. When not optimizing, leave them alone. */
2859 if (was_code_label
&& LABEL_NAME (insn
) != 0)
2863 const char *name
= LABEL_NAME (insn
);
2864 PUT_CODE (insn
, NOTE
);
2865 NOTE_LINE_NUMBER (insn
) = NOTE_INSN_DELETED_LABEL
;
2866 NOTE_SOURCE_FILE (insn
) = name
;
2869 dont_really_delete
= 1;
2872 /* Mark this insn as deleted. */
2873 INSN_DELETED_P (insn
) = 1;
2875 /* If this is an unconditional jump, delete it from the jump chain. */
2876 if (simplejump_p (insn
))
2877 delete_from_jump_chain (insn
);
2879 /* If instruction is followed by a barrier,
2880 delete the barrier too. */
2882 if (next
!= 0 && GET_CODE (next
) == BARRIER
)
2884 INSN_DELETED_P (next
) = 1;
2885 next
= NEXT_INSN (next
);
2888 /* Patch out INSN (and the barrier if any) */
2890 if (! dont_really_delete
)
2894 NEXT_INSN (prev
) = next
;
2895 if (GET_CODE (prev
) == INSN
&& GET_CODE (PATTERN (prev
)) == SEQUENCE
)
2896 NEXT_INSN (XVECEXP (PATTERN (prev
), 0,
2897 XVECLEN (PATTERN (prev
), 0) - 1)) = next
;
2902 PREV_INSN (next
) = prev
;
2903 if (GET_CODE (next
) == INSN
&& GET_CODE (PATTERN (next
)) == SEQUENCE
)
2904 PREV_INSN (XVECEXP (PATTERN (next
), 0, 0)) = prev
;
2907 if (prev
&& NEXT_INSN (prev
) == 0)
2908 set_last_insn (prev
);
2911 /* If deleting a jump, decrement the count of the label,
2912 and delete the label if it is now unused. */
2914 if (GET_CODE (insn
) == JUMP_INSN
&& JUMP_LABEL (insn
))
2916 rtx lab
= JUMP_LABEL (insn
), lab_next
;
2918 if (--LABEL_NUSES (lab
) == 0)
2920 /* This can delete NEXT or PREV,
2921 either directly if NEXT is JUMP_LABEL (INSN),
2922 or indirectly through more levels of jumps. */
2925 /* I feel a little doubtful about this loop,
2926 but I see no clean and sure alternative way
2927 to find the first insn after INSN that is not now deleted.
2928 I hope this works. */
2929 while (next
&& INSN_DELETED_P (next
))
2930 next
= NEXT_INSN (next
);
2933 else if ((lab_next
= next_nonnote_insn (lab
)) != NULL
2934 && GET_CODE (lab_next
) == JUMP_INSN
2935 && (GET_CODE (PATTERN (lab_next
)) == ADDR_VEC
2936 || GET_CODE (PATTERN (lab_next
)) == ADDR_DIFF_VEC
))
2938 /* If we're deleting the tablejump, delete the dispatch table.
2939 We may not be able to kill the label immediately preceeding
2940 just yet, as it might be referenced in code leading up to
2942 delete_insn (lab_next
);
2946 /* Likewise if we're deleting a dispatch table. */
2948 if (GET_CODE (insn
) == JUMP_INSN
2949 && (GET_CODE (PATTERN (insn
)) == ADDR_VEC
2950 || GET_CODE (PATTERN (insn
)) == ADDR_DIFF_VEC
))
2952 rtx pat
= PATTERN (insn
);
2953 int i
, diff_vec_p
= GET_CODE (pat
) == ADDR_DIFF_VEC
;
2954 int len
= XVECLEN (pat
, diff_vec_p
);
2956 for (i
= 0; i
< len
; i
++)
2957 if (--LABEL_NUSES (XEXP (XVECEXP (pat
, diff_vec_p
, i
), 0)) == 0)
2958 delete_insn (XEXP (XVECEXP (pat
, diff_vec_p
, i
), 0));
2959 while (next
&& INSN_DELETED_P (next
))
2960 next
= NEXT_INSN (next
);
2964 /* Likewise for an ordinary INSN / CALL_INSN with a REG_LABEL note. */
2965 if (GET_CODE (insn
) == INSN
|| GET_CODE (insn
) == CALL_INSN
)
2966 for (note
= REG_NOTES (insn
); note
; note
= XEXP (note
, 1))
2967 if (REG_NOTE_KIND (note
) == REG_LABEL
2968 /* This could also be a NOTE_INSN_DELETED_LABEL note. */
2969 && GET_CODE (XEXP (note
, 0)) == CODE_LABEL
)
2970 if (--LABEL_NUSES (XEXP (note
, 0)) == 0)
2971 delete_insn (XEXP (note
, 0));
2973 while (prev
&& (INSN_DELETED_P (prev
) || GET_CODE (prev
) == NOTE
))
2974 prev
= PREV_INSN (prev
);
2976 /* If INSN was a label and a dispatch table follows it,
2977 delete the dispatch table. The tablejump must have gone already.
2978 It isn't useful to fall through into a table. */
2981 && NEXT_INSN (insn
) != 0
2982 && GET_CODE (NEXT_INSN (insn
)) == JUMP_INSN
2983 && (GET_CODE (PATTERN (NEXT_INSN (insn
))) == ADDR_VEC
2984 || GET_CODE (PATTERN (NEXT_INSN (insn
))) == ADDR_DIFF_VEC
))
2985 next
= delete_insn (NEXT_INSN (insn
));
2987 /* If INSN was a label, delete insns following it if now unreachable. */
2989 if (was_code_label
&& prev
&& GET_CODE (prev
) == BARRIER
)
2991 register RTX_CODE code
;
2993 && (GET_RTX_CLASS (code
= GET_CODE (next
)) == 'i'
2994 || code
== NOTE
|| code
== BARRIER
2995 || (code
== CODE_LABEL
&& INSN_DELETED_P (next
))))
2998 && NOTE_LINE_NUMBER (next
) != NOTE_INSN_FUNCTION_END
)
2999 next
= NEXT_INSN (next
);
3000 /* Keep going past other deleted labels to delete what follows. */
3001 else if (code
== CODE_LABEL
&& INSN_DELETED_P (next
))
3002 next
= NEXT_INSN (next
);
3004 /* Note: if this deletes a jump, it can cause more
3005 deletion of unreachable code, after a different label.
3006 As long as the value from this recursive call is correct,
3007 this invocation functions correctly. */
3008 next
= delete_insn (next
);
3015 /* Advance from INSN till reaching something not deleted
3016 then return that. May return INSN itself. */
3019 next_nondeleted_insn (insn
)
3022 while (INSN_DELETED_P (insn
))
3023 insn
= NEXT_INSN (insn
);
3027 /* Delete a range of insns from FROM to TO, inclusive.
3028 This is for the sake of peephole optimization, so assume
3029 that whatever these insns do will still be done by a new
3030 peephole insn that will replace them. */
3033 delete_for_peephole (from
, to
)
3034 register rtx from
, to
;
3036 register rtx insn
= from
;
3040 register rtx next
= NEXT_INSN (insn
);
3041 register rtx prev
= PREV_INSN (insn
);
3043 if (GET_CODE (insn
) != NOTE
)
3045 INSN_DELETED_P (insn
) = 1;
3047 /* Patch this insn out of the chain. */
3048 /* We don't do this all at once, because we
3049 must preserve all NOTEs. */
3051 NEXT_INSN (prev
) = next
;
3054 PREV_INSN (next
) = prev
;
3062 /* Note that if TO is an unconditional jump
3063 we *do not* delete the BARRIER that follows,
3064 since the peephole that replaces this sequence
3065 is also an unconditional jump in that case. */
3068 /* We have determined that INSN is never reached, and are about to
3069 delete it. Print a warning if the user asked for one.
3071 To try to make this warning more useful, this should only be called
3072 once per basic block not reached, and it only warns when the basic
3073 block contains more than one line from the current function, and
3074 contains at least one operation. CSE and inlining can duplicate insns,
3075 so it's possible to get spurious warnings from this. */
3078 never_reached_warning (avoided_insn
)
3082 rtx a_line_note
= NULL
;
3083 int two_avoided_lines
= 0;
3084 int contains_insn
= 0;
3086 if (! warn_notreached
)
3089 /* Scan forwards, looking at LINE_NUMBER notes, until
3090 we hit a LABEL or we run out of insns. */
3092 for (insn
= avoided_insn
; insn
!= NULL
; insn
= NEXT_INSN (insn
))
3094 if (GET_CODE (insn
) == CODE_LABEL
)
3096 else if (GET_CODE (insn
) == NOTE
/* A line number note? */
3097 && NOTE_LINE_NUMBER (insn
) >= 0)
3099 if (a_line_note
== NULL
)
3102 two_avoided_lines
|= (NOTE_LINE_NUMBER (a_line_note
)
3103 != NOTE_LINE_NUMBER (insn
));
3105 else if (INSN_P (insn
))
3108 if (two_avoided_lines
&& contains_insn
)
3109 warning_with_file_and_line (NOTE_SOURCE_FILE (a_line_note
),
3110 NOTE_LINE_NUMBER (a_line_note
),
3111 "will never be executed");
3114 /* Throughout LOC, redirect OLABEL to NLABEL. Treat null OLABEL or
3115 NLABEL as a return. Accrue modifications into the change group. */
3118 redirect_exp_1 (loc
, olabel
, nlabel
, insn
)
3123 register rtx x
= *loc
;
3124 register RTX_CODE code
= GET_CODE (x
);
3126 register const char *fmt
;
3128 if (code
== LABEL_REF
)
3130 if (XEXP (x
, 0) == olabel
)
3134 n
= gen_rtx_LABEL_REF (VOIDmode
, nlabel
);
3136 n
= gen_rtx_RETURN (VOIDmode
);
3138 validate_change (insn
, loc
, n
, 1);
3142 else if (code
== RETURN
&& olabel
== 0)
3144 x
= gen_rtx_LABEL_REF (VOIDmode
, nlabel
);
3145 if (loc
== &PATTERN (insn
))
3146 x
= gen_rtx_SET (VOIDmode
, pc_rtx
, x
);
3147 validate_change (insn
, loc
, x
, 1);
3151 if (code
== SET
&& nlabel
== 0 && SET_DEST (x
) == pc_rtx
3152 && GET_CODE (SET_SRC (x
)) == LABEL_REF
3153 && XEXP (SET_SRC (x
), 0) == olabel
)
3155 validate_change (insn
, loc
, gen_rtx_RETURN (VOIDmode
), 1);
3159 fmt
= GET_RTX_FORMAT (code
);
3160 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
3163 redirect_exp_1 (&XEXP (x
, i
), olabel
, nlabel
, insn
);
3164 else if (fmt
[i
] == 'E')
3167 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
3168 redirect_exp_1 (&XVECEXP (x
, i
, j
), olabel
, nlabel
, insn
);
3173 /* Similar, but apply the change group and report success or failure. */
3176 redirect_exp (olabel
, nlabel
, insn
)
3182 if (GET_CODE (PATTERN (insn
)) == PARALLEL
)
3183 loc
= &XVECEXP (PATTERN (insn
), 0, 0);
3185 loc
= &PATTERN (insn
);
3187 redirect_exp_1 (loc
, olabel
, nlabel
, insn
);
3188 if (num_validated_changes () == 0)
3191 return apply_change_group ();
3194 /* Make JUMP go to NLABEL instead of where it jumps now. Accrue
3195 the modifications into the change group. Return false if we did
3196 not see how to do that. */
3199 redirect_jump_1 (jump
, nlabel
)
3202 int ochanges
= num_validated_changes ();
3205 if (GET_CODE (PATTERN (jump
)) == PARALLEL
)
3206 loc
= &XVECEXP (PATTERN (jump
), 0, 0);
3208 loc
= &PATTERN (jump
);
3210 redirect_exp_1 (loc
, JUMP_LABEL (jump
), nlabel
, jump
);
3211 return num_validated_changes () > ochanges
;
3214 /* Make JUMP go to NLABEL instead of where it jumps now. If the old
3215 jump target label is unused as a result, it and the code following
3218 If NLABEL is zero, we are to turn the jump into a (possibly conditional)
3221 The return value will be 1 if the change was made, 0 if it wasn't
3222 (this can only occur for NLABEL == 0). */
3225 redirect_jump (jump
, nlabel
, delete_unused
)
3229 register rtx olabel
= JUMP_LABEL (jump
);
3231 if (nlabel
== olabel
)
3234 if (! redirect_exp (olabel
, nlabel
, jump
))
3237 /* If this is an unconditional branch, delete it from the jump_chain of
3238 OLABEL and add it to the jump_chain of NLABEL (assuming both labels
3239 have UID's in range and JUMP_CHAIN is valid). */
3240 if (jump_chain
&& (simplejump_p (jump
)
3241 || GET_CODE (PATTERN (jump
)) == RETURN
))
3243 int label_index
= nlabel
? INSN_UID (nlabel
) : 0;
3245 delete_from_jump_chain (jump
);
3246 if (label_index
< max_jump_chain
3247 && INSN_UID (jump
) < max_jump_chain
)
3249 jump_chain
[INSN_UID (jump
)] = jump_chain
[label_index
];
3250 jump_chain
[label_index
] = jump
;
3254 JUMP_LABEL (jump
) = nlabel
;
3256 ++LABEL_NUSES (nlabel
);
3258 /* If we're eliding the jump over exception cleanups at the end of a
3259 function, move the function end note so that -Wreturn-type works. */
3260 if (olabel
&& nlabel
3261 && NEXT_INSN (olabel
)
3262 && GET_CODE (NEXT_INSN (olabel
)) == NOTE
3263 && NOTE_LINE_NUMBER (NEXT_INSN (olabel
)) == NOTE_INSN_FUNCTION_END
)
3264 emit_note_after (NOTE_INSN_FUNCTION_END
, nlabel
);
3266 if (olabel
&& --LABEL_NUSES (olabel
) == 0 && delete_unused
)
3267 delete_insn (olabel
);
3272 /* Invert the jump condition of rtx X contained in jump insn, INSN.
3273 Accrue the modifications into the change group. */
3279 register RTX_CODE code
;
3280 rtx x
= pc_set (insn
);
3286 code
= GET_CODE (x
);
3288 if (code
== IF_THEN_ELSE
)
3290 register rtx comp
= XEXP (x
, 0);
3292 enum rtx_code reversed_code
;
3294 /* We can do this in two ways: The preferable way, which can only
3295 be done if this is not an integer comparison, is to reverse
3296 the comparison code. Otherwise, swap the THEN-part and ELSE-part
3297 of the IF_THEN_ELSE. If we can't do either, fail. */
3299 reversed_code
= reversed_comparison_code (comp
, insn
);
3301 if (reversed_code
!= UNKNOWN
)
3303 validate_change (insn
, &XEXP (x
, 0),
3304 gen_rtx_fmt_ee (reversed_code
,
3305 GET_MODE (comp
), XEXP (comp
, 0),
3312 validate_change (insn
, &XEXP (x
, 1), XEXP (x
, 2), 1);
3313 validate_change (insn
, &XEXP (x
, 2), tem
, 1);
3319 /* Invert the jump condition of conditional jump insn, INSN.
3321 Return 1 if we can do so, 0 if we cannot find a way to do so that
3322 matches a pattern. */
3328 invert_exp_1 (insn
);
3329 if (num_validated_changes () == 0)
3332 return apply_change_group ();
3335 /* Invert the condition of the jump JUMP, and make it jump to label
3336 NLABEL instead of where it jumps now. Accrue changes into the
3337 change group. Return false if we didn't see how to perform the
3338 inversion and redirection. */
3341 invert_jump_1 (jump
, nlabel
)
3346 ochanges
= num_validated_changes ();
3347 invert_exp_1 (jump
);
3348 if (num_validated_changes () == ochanges
)
3351 return redirect_jump_1 (jump
, nlabel
);
3354 /* Invert the condition of the jump JUMP, and make it jump to label
3355 NLABEL instead of where it jumps now. Return true if successful. */
3358 invert_jump (jump
, nlabel
, delete_unused
)
3362 /* We have to either invert the condition and change the label or
3363 do neither. Either operation could fail. We first try to invert
3364 the jump. If that succeeds, we try changing the label. If that fails,
3365 we invert the jump back to what it was. */
3367 if (! invert_exp (jump
))
3370 if (redirect_jump (jump
, nlabel
, delete_unused
))
3372 invert_br_probabilities (jump
);
3377 if (! invert_exp (jump
))
3378 /* This should just be putting it back the way it was. */
3384 /* Delete the instruction JUMP from any jump chain it might be on. */
3387 delete_from_jump_chain (jump
)
3391 rtx olabel
= JUMP_LABEL (jump
);
3393 /* Handle unconditional jumps. */
3394 if (jump_chain
&& olabel
!= 0
3395 && INSN_UID (olabel
) < max_jump_chain
3396 && simplejump_p (jump
))
3397 index
= INSN_UID (olabel
);
3398 /* Handle return insns. */
3399 else if (jump_chain
&& GET_CODE (PATTERN (jump
)) == RETURN
)
3404 if (jump_chain
[index
] == jump
)
3405 jump_chain
[index
] = jump_chain
[INSN_UID (jump
)];
3410 for (insn
= jump_chain
[index
];
3412 insn
= jump_chain
[INSN_UID (insn
)])
3413 if (jump_chain
[INSN_UID (insn
)] == jump
)
3415 jump_chain
[INSN_UID (insn
)] = jump_chain
[INSN_UID (jump
)];
3421 /* Make jump JUMP jump to label NLABEL, assuming it used to be a tablejump.
3423 If the old jump target label (before the dispatch table) becomes unused,
3424 it and the dispatch table may be deleted. In that case, find the insn
3425 before the jump references that label and delete it and logical successors
3429 redirect_tablejump (jump
, nlabel
)
3432 register rtx olabel
= JUMP_LABEL (jump
);
3433 rtx
*notep
, note
, next
;
3435 /* Add this jump to the jump_chain of NLABEL. */
3436 if (jump_chain
&& INSN_UID (nlabel
) < max_jump_chain
3437 && INSN_UID (jump
) < max_jump_chain
)
3439 jump_chain
[INSN_UID (jump
)] = jump_chain
[INSN_UID (nlabel
)];
3440 jump_chain
[INSN_UID (nlabel
)] = jump
;
3443 for (notep
= ®_NOTES (jump
), note
= *notep
; note
; note
= next
)
3445 next
= XEXP (note
, 1);
3447 if (REG_NOTE_KIND (note
) != REG_DEAD
3448 /* Verify that the REG_NOTE is legitimate. */
3449 || GET_CODE (XEXP (note
, 0)) != REG
3450 || ! reg_mentioned_p (XEXP (note
, 0), PATTERN (jump
)))
3451 notep
= &XEXP (note
, 1);
3454 delete_prior_computation (note
, jump
);
3459 PATTERN (jump
) = gen_jump (nlabel
);
3460 JUMP_LABEL (jump
) = nlabel
;
3461 ++LABEL_NUSES (nlabel
);
3462 INSN_CODE (jump
) = -1;
3464 if (--LABEL_NUSES (olabel
) == 0)
3466 delete_labelref_insn (jump
, olabel
, 0);
3467 delete_insn (olabel
);
3471 /* Find the insn referencing LABEL that is a logical predecessor of INSN.
3472 If we found one, delete it and then delete this insn if DELETE_THIS is
3473 non-zero. Return non-zero if INSN or a predecessor references LABEL. */
3476 delete_labelref_insn (insn
, label
, delete_this
)
3483 if (GET_CODE (insn
) != NOTE
3484 && reg_mentioned_p (label
, PATTERN (insn
)))
3495 for (link
= LOG_LINKS (insn
); link
; link
= XEXP (link
, 1))
3496 if (delete_labelref_insn (XEXP (link
, 0), label
, 1))
3510 /* Like rtx_equal_p except that it considers two REGs as equal
3511 if they renumber to the same value and considers two commutative
3512 operations to be the same if the order of the operands has been
3515 ??? Addition is not commutative on the PA due to the weird implicit
3516 space register selection rules for memory addresses. Therefore, we
3517 don't consider a + b == b + a.
3519 We could/should make this test a little tighter. Possibly only
3520 disabling it on the PA via some backend macro or only disabling this
3521 case when the PLUS is inside a MEM. */
3524 rtx_renumbered_equal_p (x
, y
)
3528 register RTX_CODE code
= GET_CODE (x
);
3529 register const char *fmt
;
3534 if ((code
== REG
|| (code
== SUBREG
&& GET_CODE (SUBREG_REG (x
)) == REG
))
3535 && (GET_CODE (y
) == REG
|| (GET_CODE (y
) == SUBREG
3536 && GET_CODE (SUBREG_REG (y
)) == REG
)))
3538 int reg_x
= -1, reg_y
= -1;
3539 int byte_x
= 0, byte_y
= 0;
3541 if (GET_MODE (x
) != GET_MODE (y
))
3544 /* If we haven't done any renumbering, don't
3545 make any assumptions. */
3546 if (reg_renumber
== 0)
3547 return rtx_equal_p (x
, y
);
3551 reg_x
= REGNO (SUBREG_REG (x
));
3552 byte_x
= SUBREG_BYTE (x
);
3554 if (reg_renumber
[reg_x
] >= 0)
3556 reg_x
= subreg_regno_offset (reg_renumber
[reg_x
],
3557 GET_MODE (SUBREG_REG (x
)),
3566 if (reg_renumber
[reg_x
] >= 0)
3567 reg_x
= reg_renumber
[reg_x
];
3570 if (GET_CODE (y
) == SUBREG
)
3572 reg_y
= REGNO (SUBREG_REG (y
));
3573 byte_y
= SUBREG_BYTE (y
);
3575 if (reg_renumber
[reg_y
] >= 0)
3577 reg_y
= subreg_regno_offset (reg_renumber
[reg_y
],
3578 GET_MODE (SUBREG_REG (y
)),
3587 if (reg_renumber
[reg_y
] >= 0)
3588 reg_y
= reg_renumber
[reg_y
];
3591 return reg_x
>= 0 && reg_x
== reg_y
&& byte_x
== byte_y
;
3594 /* Now we have disposed of all the cases
3595 in which different rtx codes can match. */
3596 if (code
!= GET_CODE (y
))
3608 return INTVAL (x
) == INTVAL (y
);
3611 /* We can't assume nonlocal labels have their following insns yet. */
3612 if (LABEL_REF_NONLOCAL_P (x
) || LABEL_REF_NONLOCAL_P (y
))
3613 return XEXP (x
, 0) == XEXP (y
, 0);
3615 /* Two label-refs are equivalent if they point at labels
3616 in the same position in the instruction stream. */
3617 return (next_real_insn (XEXP (x
, 0))
3618 == next_real_insn (XEXP (y
, 0)));
3621 return XSTR (x
, 0) == XSTR (y
, 0);
3624 /* If we didn't match EQ equality above, they aren't the same. */
3631 /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. */
3633 if (GET_MODE (x
) != GET_MODE (y
))
3636 /* For commutative operations, the RTX match if the operand match in any
3637 order. Also handle the simple binary and unary cases without a loop.
3639 ??? Don't consider PLUS a commutative operator; see comments above. */
3640 if ((code
== EQ
|| code
== NE
|| GET_RTX_CLASS (code
) == 'c')
3642 return ((rtx_renumbered_equal_p (XEXP (x
, 0), XEXP (y
, 0))
3643 && rtx_renumbered_equal_p (XEXP (x
, 1), XEXP (y
, 1)))
3644 || (rtx_renumbered_equal_p (XEXP (x
, 0), XEXP (y
, 1))
3645 && rtx_renumbered_equal_p (XEXP (x
, 1), XEXP (y
, 0))));
3646 else if (GET_RTX_CLASS (code
) == '<' || GET_RTX_CLASS (code
) == '2')
3647 return (rtx_renumbered_equal_p (XEXP (x
, 0), XEXP (y
, 0))
3648 && rtx_renumbered_equal_p (XEXP (x
, 1), XEXP (y
, 1)));
3649 else if (GET_RTX_CLASS (code
) == '1')
3650 return rtx_renumbered_equal_p (XEXP (x
, 0), XEXP (y
, 0));
3652 /* Compare the elements. If any pair of corresponding elements
3653 fail to match, return 0 for the whole things. */
3655 fmt
= GET_RTX_FORMAT (code
);
3656 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
3662 if (XWINT (x
, i
) != XWINT (y
, i
))
3667 if (XINT (x
, i
) != XINT (y
, i
))
3672 if (strcmp (XSTR (x
, i
), XSTR (y
, i
)))
3677 if (! rtx_renumbered_equal_p (XEXP (x
, i
), XEXP (y
, i
)))
3682 if (XEXP (x
, i
) != XEXP (y
, i
))
3689 if (XVECLEN (x
, i
) != XVECLEN (y
, i
))
3691 for (j
= XVECLEN (x
, i
) - 1; j
>= 0; j
--)
3692 if (!rtx_renumbered_equal_p (XVECEXP (x
, i
, j
), XVECEXP (y
, i
, j
)))
3703 /* If X is a hard register or equivalent to one or a subregister of one,
3704 return the hard register number. If X is a pseudo register that was not
3705 assigned a hard register, return the pseudo register number. Otherwise,
3706 return -1. Any rtx is valid for X. */
3712 if (GET_CODE (x
) == REG
)
3714 if (REGNO (x
) >= FIRST_PSEUDO_REGISTER
&& reg_renumber
[REGNO (x
)] >= 0)
3715 return reg_renumber
[REGNO (x
)];
3718 if (GET_CODE (x
) == SUBREG
)
3720 int base
= true_regnum (SUBREG_REG (x
));
3721 if (base
>= 0 && base
< FIRST_PSEUDO_REGISTER
)
3722 return base
+ subreg_regno_offset (REGNO (SUBREG_REG (x
)),
3723 GET_MODE (SUBREG_REG (x
)),
3724 SUBREG_BYTE (x
), GET_MODE (x
));
3729 /* Optimize code of the form:
3731 for (x = a[i]; x; ...)
3733 for (x = a[i]; x; ...)
3737 Loop optimize will change the above code into
3741 { ...; if (! (x = ...)) break; }
3744 { ...; if (! (x = ...)) break; }
3747 In general, if the first test fails, the program can branch
3748 directly to `foo' and skip the second try which is doomed to fail.
3749 We run this after loop optimization and before flow analysis. */
3751 /* When comparing the insn patterns, we track the fact that different
3752 pseudo-register numbers may have been used in each computation.
3753 The following array stores an equivalence -- same_regs[I] == J means
3754 that pseudo register I was used in the first set of tests in a context
3755 where J was used in the second set. We also count the number of such
3756 pending equivalences. If nonzero, the expressions really aren't the
3759 static int *same_regs
;
3761 static int num_same_regs
;
3763 /* Track any registers modified between the target of the first jump and
3764 the second jump. They never compare equal. */
3766 static char *modified_regs
;
3768 /* Record if memory was modified. */
3770 static int modified_mem
;
3772 /* Called via note_stores on each insn between the target of the first
3773 branch and the second branch. It marks any changed registers. */
3776 mark_modified_reg (dest
, x
, data
)
3779 void *data ATTRIBUTE_UNUSED
;
3784 if (GET_CODE (dest
) == SUBREG
)
3785 dest
= SUBREG_REG (dest
);
3787 if (GET_CODE (dest
) == MEM
)
3790 if (GET_CODE (dest
) != REG
)
3793 regno
= REGNO (dest
);
3794 if (regno
>= FIRST_PSEUDO_REGISTER
)
3795 modified_regs
[regno
] = 1;
3796 /* Don't consider a hard condition code register as modified,
3797 if it is only being set. thread_jumps will check if it is set
3798 to the same value. */
3799 else if (GET_MODE_CLASS (GET_MODE (dest
)) != MODE_CC
3800 || GET_CODE (x
) != SET
3801 || ! rtx_equal_p (dest
, SET_DEST (x
))
3802 || HARD_REGNO_NREGS (regno
, GET_MODE (dest
)) != 1)
3803 for (i
= 0; i
< HARD_REGNO_NREGS (regno
, GET_MODE (dest
)); i
++)
3804 modified_regs
[regno
+ i
] = 1;
3807 /* F is the first insn in the chain of insns. */
3810 thread_jumps (f
, max_reg
, flag_before_loop
)
3813 int flag_before_loop
;
3815 /* Basic algorithm is to find a conditional branch,
3816 the label it may branch to, and the branch after
3817 that label. If the two branches test the same condition,
3818 walk back from both branch paths until the insn patterns
3819 differ, or code labels are hit. If we make it back to
3820 the target of the first branch, then we know that the first branch
3821 will either always succeed or always fail depending on the relative
3822 senses of the two branches. So adjust the first branch accordingly
3825 rtx label
, b1
, b2
, t1
, t2
;
3826 enum rtx_code code1
, code2
;
3827 rtx b1op0
, b1op1
, b2op0
, b2op1
;
3831 enum rtx_code reversed_code1
, reversed_code2
;
3833 /* Allocate register tables and quick-reset table. */
3834 modified_regs
= (char *) xmalloc (max_reg
* sizeof (char));
3835 same_regs
= (int *) xmalloc (max_reg
* sizeof (int));
3836 all_reset
= (int *) xmalloc (max_reg
* sizeof (int));
3837 for (i
= 0; i
< max_reg
; i
++)
3844 for (b1
= f
; b1
; b1
= NEXT_INSN (b1
))
3849 /* Get to a candidate branch insn. */
3850 if (GET_CODE (b1
) != JUMP_INSN
3851 || ! any_condjump_p (b1
) || JUMP_LABEL (b1
) == 0)
3854 memset (modified_regs
, 0, max_reg
* sizeof (char));
3857 memcpy (same_regs
, all_reset
, max_reg
* sizeof (int));
3860 label
= JUMP_LABEL (b1
);
3862 /* Look for a branch after the target. Record any registers and
3863 memory modified between the target and the branch. Stop when we
3864 get to a label since we can't know what was changed there. */
3865 for (b2
= NEXT_INSN (label
); b2
; b2
= NEXT_INSN (b2
))
3867 if (GET_CODE (b2
) == CODE_LABEL
)
3870 else if (GET_CODE (b2
) == JUMP_INSN
)
3872 /* If this is an unconditional jump and is the only use of
3873 its target label, we can follow it. */
3874 if (any_uncondjump_p (b2
)
3876 && JUMP_LABEL (b2
) != 0
3877 && LABEL_NUSES (JUMP_LABEL (b2
)) == 1)
3879 b2
= JUMP_LABEL (b2
);
3886 if (GET_CODE (b2
) != CALL_INSN
&& GET_CODE (b2
) != INSN
)
3889 if (GET_CODE (b2
) == CALL_INSN
)
3892 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; i
++)
3893 if (call_used_regs
[i
] && ! fixed_regs
[i
]
3894 && i
!= STACK_POINTER_REGNUM
3895 && i
!= FRAME_POINTER_REGNUM
3896 && i
!= HARD_FRAME_POINTER_REGNUM
3897 && i
!= ARG_POINTER_REGNUM
)
3898 modified_regs
[i
] = 1;
3901 note_stores (PATTERN (b2
), mark_modified_reg
, NULL
);
3904 /* Check the next candidate branch insn from the label
3907 || GET_CODE (b2
) != JUMP_INSN
3909 || !any_condjump_p (b2
)
3910 || !onlyjump_p (b2
))
3915 /* Get the comparison codes and operands, reversing the
3916 codes if appropriate. If we don't have comparison codes,
3917 we can't do anything. */
3918 b1op0
= XEXP (XEXP (SET_SRC (set
), 0), 0);
3919 b1op1
= XEXP (XEXP (SET_SRC (set
), 0), 1);
3920 code1
= GET_CODE (XEXP (SET_SRC (set
), 0));
3921 reversed_code1
= code1
;
3922 if (XEXP (SET_SRC (set
), 1) == pc_rtx
)
3923 code1
= reversed_comparison_code (XEXP (SET_SRC (set
), 0), b1
);
3925 reversed_code1
= reversed_comparison_code (XEXP (SET_SRC (set
), 0), b1
);
3927 b2op0
= XEXP (XEXP (SET_SRC (set2
), 0), 0);
3928 b2op1
= XEXP (XEXP (SET_SRC (set2
), 0), 1);
3929 code2
= GET_CODE (XEXP (SET_SRC (set2
), 0));
3930 reversed_code2
= code2
;
3931 if (XEXP (SET_SRC (set2
), 1) == pc_rtx
)
3932 code2
= reversed_comparison_code (XEXP (SET_SRC (set2
), 0), b2
);
3934 reversed_code2
= reversed_comparison_code (XEXP (SET_SRC (set2
), 0), b2
);
3936 /* If they test the same things and knowing that B1 branches
3937 tells us whether or not B2 branches, check if we
3938 can thread the branch. */
3939 if (rtx_equal_for_thread_p (b1op0
, b2op0
, b2
)
3940 && rtx_equal_for_thread_p (b1op1
, b2op1
, b2
)
3941 && (comparison_dominates_p (code1
, code2
)
3942 || comparison_dominates_p (code1
, reversed_code2
)))
3945 t1
= prev_nonnote_insn (b1
);
3946 t2
= prev_nonnote_insn (b2
);
3948 while (t1
!= 0 && t2
!= 0)
3952 /* We have reached the target of the first branch.
3953 If there are no pending register equivalents,
3954 we know that this branch will either always
3955 succeed (if the senses of the two branches are
3956 the same) or always fail (if not). */
3959 if (num_same_regs
!= 0)
3962 if (comparison_dominates_p (code1
, code2
))
3963 new_label
= JUMP_LABEL (b2
);
3965 new_label
= get_label_after (b2
);
3967 if (JUMP_LABEL (b1
) != new_label
)
3969 rtx prev
= PREV_INSN (new_label
);
3971 if (flag_before_loop
3972 && GET_CODE (prev
) == NOTE
3973 && NOTE_LINE_NUMBER (prev
) == NOTE_INSN_LOOP_BEG
)
3975 /* Don't thread to the loop label. If a loop
3976 label is reused, loop optimization will
3977 be disabled for that loop. */
3978 new_label
= gen_label_rtx ();
3979 emit_label_after (new_label
, PREV_INSN (prev
));
3981 changed
|= redirect_jump (b1
, new_label
, 1);
3986 /* If either of these is not a normal insn (it might be
3987 a JUMP_INSN, CALL_INSN, or CODE_LABEL) we fail. (NOTEs
3988 have already been skipped above.) Similarly, fail
3989 if the insns are different. */
3990 if (GET_CODE (t1
) != INSN
|| GET_CODE (t2
) != INSN
3991 || recog_memoized (t1
) != recog_memoized (t2
)
3992 || ! rtx_equal_for_thread_p (PATTERN (t1
),
3996 t1
= prev_nonnote_insn (t1
);
3997 t2
= prev_nonnote_insn (t2
);
4004 free (modified_regs
);
4009 /* This is like RTX_EQUAL_P except that it knows about our handling of
4010 possibly equivalent registers and knows to consider volatile and
4011 modified objects as not equal.
4013 YINSN is the insn containing Y. */
4016 rtx_equal_for_thread_p (x
, y
, yinsn
)
4022 register enum rtx_code code
;
4023 register const char *fmt
;
4025 code
= GET_CODE (x
);
4026 /* Rtx's of different codes cannot be equal. */
4027 if (code
!= GET_CODE (y
))
4030 /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent.
4031 (REG:SI x) and (REG:HI x) are NOT equivalent. */
4033 if (GET_MODE (x
) != GET_MODE (y
))
4036 /* For floating-point, consider everything unequal. This is a bit
4037 pessimistic, but this pass would only rarely do anything for FP
4039 if (TARGET_FLOAT_FORMAT
== IEEE_FLOAT_FORMAT
4040 && FLOAT_MODE_P (GET_MODE (x
)) && ! flag_unsafe_math_optimizations
)
4043 /* For commutative operations, the RTX match if the operand match in any
4044 order. Also handle the simple binary and unary cases without a loop. */
4045 if (code
== EQ
|| code
== NE
|| GET_RTX_CLASS (code
) == 'c')
4046 return ((rtx_equal_for_thread_p (XEXP (x
, 0), XEXP (y
, 0), yinsn
)
4047 && rtx_equal_for_thread_p (XEXP (x
, 1), XEXP (y
, 1), yinsn
))
4048 || (rtx_equal_for_thread_p (XEXP (x
, 0), XEXP (y
, 1), yinsn
)
4049 && rtx_equal_for_thread_p (XEXP (x
, 1), XEXP (y
, 0), yinsn
)));
4050 else if (GET_RTX_CLASS (code
) == '<' || GET_RTX_CLASS (code
) == '2')
4051 return (rtx_equal_for_thread_p (XEXP (x
, 0), XEXP (y
, 0), yinsn
)
4052 && rtx_equal_for_thread_p (XEXP (x
, 1), XEXP (y
, 1), yinsn
));
4053 else if (GET_RTX_CLASS (code
) == '1')
4054 return rtx_equal_for_thread_p (XEXP (x
, 0), XEXP (y
, 0), yinsn
);
4056 /* Handle special-cases first. */
4060 if (REGNO (x
) == REGNO (y
) && ! modified_regs
[REGNO (x
)])
4063 /* If neither is user variable or hard register, check for possible
4065 if (REG_USERVAR_P (x
) || REG_USERVAR_P (y
)
4066 || REGNO (x
) < FIRST_PSEUDO_REGISTER
4067 || REGNO (y
) < FIRST_PSEUDO_REGISTER
)
4070 if (same_regs
[REGNO (x
)] == -1)
4072 same_regs
[REGNO (x
)] = REGNO (y
);
4075 /* If this is the first time we are seeing a register on the `Y'
4076 side, see if it is the last use. If not, we can't thread the
4077 jump, so mark it as not equivalent. */
4078 if (REGNO_LAST_UID (REGNO (y
)) != INSN_UID (yinsn
))
4084 return (same_regs
[REGNO (x
)] == (int) REGNO (y
));
4089 /* If memory modified or either volatile, not equivalent.
4090 Else, check address. */
4091 if (modified_mem
|| MEM_VOLATILE_P (x
) || MEM_VOLATILE_P (y
))
4094 return rtx_equal_for_thread_p (XEXP (x
, 0), XEXP (y
, 0), yinsn
);
4097 if (MEM_VOLATILE_P (x
) || MEM_VOLATILE_P (y
))
4103 /* Cancel a pending `same_regs' if setting equivalenced registers.
4104 Then process source. */
4105 if (GET_CODE (SET_DEST (x
)) == REG
4106 && GET_CODE (SET_DEST (y
)) == REG
)
4108 if (same_regs
[REGNO (SET_DEST (x
))] == (int) REGNO (SET_DEST (y
)))
4110 same_regs
[REGNO (SET_DEST (x
))] = -1;
4113 else if (REGNO (SET_DEST (x
)) != REGNO (SET_DEST (y
)))
4118 if (rtx_equal_for_thread_p (SET_DEST (x
), SET_DEST (y
), yinsn
) == 0)
4122 return rtx_equal_for_thread_p (SET_SRC (x
), SET_SRC (y
), yinsn
);
4125 return XEXP (x
, 0) == XEXP (y
, 0);
4128 return XSTR (x
, 0) == XSTR (y
, 0);
4137 fmt
= GET_RTX_FORMAT (code
);
4138 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
4143 if (XWINT (x
, i
) != XWINT (y
, i
))
4149 if (XINT (x
, i
) != XINT (y
, i
))
4155 /* Two vectors must have the same length. */
4156 if (XVECLEN (x
, i
) != XVECLEN (y
, i
))
4159 /* And the corresponding elements must match. */
4160 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
4161 if (rtx_equal_for_thread_p (XVECEXP (x
, i
, j
),
4162 XVECEXP (y
, i
, j
), yinsn
) == 0)
4167 if (rtx_equal_for_thread_p (XEXP (x
, i
), XEXP (y
, i
), yinsn
) == 0)
4173 if (strcmp (XSTR (x
, i
), XSTR (y
, i
)))
4178 /* These are just backpointers, so they don't matter. */
4185 /* It is believed that rtx's at this level will never
4186 contain anything but integers and other rtx's,
4187 except for within LABEL_REFs and SYMBOL_REFs. */