1 /* Optimize jump instructions, for GNU compiler.
2 Copyright (C) 1987, 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997
3 1998, 1999, 2000 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. */
23 /* This is the jump-optimization pass of the compiler.
24 It is run two or three times: once before cse, sometimes once after cse,
25 and once after reload (before final).
27 jump_optimize deletes unreachable code and labels that are not used.
28 It also deletes jumps that jump to the following insn,
29 and simplifies jumps around unconditional jumps and jumps
30 to unconditional jumps.
32 Each CODE_LABEL has a count of the times it is used
33 stored in the LABEL_NUSES internal field, and each JUMP_INSN
34 has one label that it refers to stored in the
35 JUMP_LABEL internal field. With this we can detect labels that
36 become unused because of the deletion of all the jumps that
37 formerly used them. The JUMP_LABEL info is sometimes looked
40 Optionally, cross-jumping can be done. Currently it is done
41 only the last time (when after reload and before final).
42 In fact, the code for cross-jumping now assumes that register
43 allocation has been done, since it uses `rtx_renumbered_equal_p'.
45 Jump optimization is done after cse when cse's constant-propagation
46 causes jumps to become unconditional or to be deleted.
48 Unreachable loops are not detected here, because the labels
49 have references and the insns appear reachable from the labels.
50 find_basic_blocks in flow.c finds and deletes such loops.
52 The subroutines delete_insn, redirect_jump, and invert_jump are used
53 from other passes as well. */
60 #include "hard-reg-set.h"
62 #include "insn-config.h"
63 #include "insn-flags.h"
64 #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 /* Set nonzero by jump_optimize if control can fall through
100 to the end of the function. */
103 /* Indicates whether death notes are significant in cross jump analysis.
104 Normally they are not significant, because of A and B jump to C,
105 and R dies in A, it must die in B. But this might not be true after
106 stack register conversion, and we must compare death notes in that
109 static int cross_jump_death_matters
= 0;
111 static int init_label_info
PARAMS ((rtx
));
112 static void delete_barrier_successors
PARAMS ((rtx
));
113 static void mark_all_labels
PARAMS ((rtx
, int));
114 static rtx delete_unreferenced_labels
PARAMS ((rtx
));
115 static void delete_noop_moves
PARAMS ((rtx
));
116 static int calculate_can_reach_end
PARAMS ((rtx
, int));
117 static int duplicate_loop_exit_test
PARAMS ((rtx
));
118 static void find_cross_jump
PARAMS ((rtx
, rtx
, int, rtx
*, rtx
*));
119 static void do_cross_jump
PARAMS ((rtx
, rtx
, rtx
));
120 static int jump_back_p
PARAMS ((rtx
, rtx
));
121 static int tension_vector_labels
PARAMS ((rtx
, int));
122 static void mark_jump_label
PARAMS ((rtx
, rtx
, int, int));
123 static void delete_computation
PARAMS ((rtx
));
124 static void redirect_exp_1
PARAMS ((rtx
*, rtx
, rtx
, rtx
));
125 static void invert_exp_1
PARAMS ((rtx
, rtx
));
126 static void delete_from_jump_chain
PARAMS ((rtx
));
127 static int delete_labelref_insn
PARAMS ((rtx
, rtx
, int));
128 static void mark_modified_reg
PARAMS ((rtx
, rtx
, void *));
129 static void redirect_tablejump
PARAMS ((rtx
, rtx
));
130 static void jump_optimize_1
PARAMS ((rtx
, int, int, int, int, int));
131 static int returnjump_p_1
PARAMS ((rtx
*, void *));
132 static void delete_prior_computation
PARAMS ((rtx
, rtx
));
134 /* Main external entry point into the jump optimizer. See comments before
135 jump_optimize_1 for descriptions of the arguments. */
137 jump_optimize (f
, cross_jump
, noop_moves
, after_regscan
)
143 jump_optimize_1 (f
, cross_jump
, noop_moves
, after_regscan
, 0, 0);
146 /* Alternate entry into the jump optimizer. This entry point only rebuilds
147 the JUMP_LABEL field in jumping insns and REG_LABEL notes in non-jumping
150 rebuild_jump_labels (f
)
153 jump_optimize_1 (f
, 0, 0, 0, 1, 0);
156 /* Alternate entry into the jump optimizer. Do only trivial optimizations. */
158 jump_optimize_minimal (f
)
161 jump_optimize_1 (f
, 0, 0, 0, 0, 1);
164 /* Delete no-op jumps and optimize jumps to jumps
165 and jumps around jumps.
166 Delete unused labels and unreachable code.
168 If CROSS_JUMP is 1, detect matching code
169 before a jump and its destination and unify them.
170 If CROSS_JUMP is 2, do cross-jumping, but pay attention to death notes.
172 If NOOP_MOVES is nonzero, delete no-op move insns.
174 If AFTER_REGSCAN is nonzero, then this jump pass is being run immediately
175 after regscan, and it is safe to use regno_first_uid and regno_last_uid.
177 If MARK_LABELS_ONLY is nonzero, then we only rebuild the jump chain
178 and JUMP_LABEL field for jumping insns.
180 If `optimize' is zero, don't change any code,
181 just determine whether control drops off the end of the function.
182 This case occurs when we have -W and not -O.
183 It works because `delete_insn' checks the value of `optimize'
184 and refrains from actually deleting when that is 0.
186 If MINIMAL is nonzero, then we only perform trivial optimizations:
188 * Removal of unreachable code after BARRIERs.
189 * Removal of unreferenced CODE_LABELs.
190 * Removal of a jump to the next instruction.
191 * Removal of a conditional jump followed by an unconditional jump
192 to the same target as the conditional jump.
193 * Simplify a conditional jump around an unconditional jump.
194 * Simplify a jump to a jump.
195 * Delete extraneous line number notes.
199 jump_optimize_1 (f
, cross_jump
, noop_moves
, after_regscan
,
200 mark_labels_only
, minimal
)
205 int mark_labels_only
;
208 register rtx insn
, next
;
215 cross_jump_death_matters
= (cross_jump
== 2);
216 max_uid
= init_label_info (f
) + 1;
218 /* If we are performing cross jump optimizations, then initialize
219 tables mapping UIDs to EH regions to avoid incorrect movement
220 of insns from one EH region to another. */
221 if (flag_exceptions
&& cross_jump
)
222 init_insn_eh_region (f
, max_uid
);
224 if (! mark_labels_only
)
225 delete_barrier_successors (f
);
227 /* Leave some extra room for labels and duplicate exit test insns
229 max_jump_chain
= max_uid
* 14 / 10;
230 jump_chain
= (rtx
*) xcalloc (max_jump_chain
, sizeof (rtx
));
232 mark_all_labels (f
, cross_jump
);
234 /* Keep track of labels used from static data;
235 they cannot ever be deleted. */
237 for (insn
= forced_labels
; insn
; insn
= XEXP (insn
, 1))
238 LABEL_NUSES (XEXP (insn
, 0))++;
240 check_exception_handler_labels ();
242 /* Keep track of labels used for marking handlers for exception
243 regions; they cannot usually be deleted. */
245 for (insn
= exception_handler_labels
; insn
; insn
= XEXP (insn
, 1))
246 LABEL_NUSES (XEXP (insn
, 0))++;
248 /* Quit now if we just wanted to rebuild the JUMP_LABEL and REG_LABEL
249 notes and recompute LABEL_NUSES. */
250 if (mark_labels_only
)
254 exception_optimize ();
256 last_insn
= delete_unreferenced_labels (f
);
259 delete_noop_moves (f
);
261 /* If we haven't yet gotten to reload and we have just run regscan,
262 delete any insn that sets a register that isn't used elsewhere.
263 This helps some of the optimizations below by having less insns
264 being jumped around. */
266 if (optimize
&& ! reload_completed
&& after_regscan
)
267 for (insn
= f
; insn
; insn
= next
)
269 rtx set
= single_set (insn
);
271 next
= NEXT_INSN (insn
);
273 if (set
&& GET_CODE (SET_DEST (set
)) == REG
274 && REGNO (SET_DEST (set
)) >= FIRST_PSEUDO_REGISTER
275 && REGNO_FIRST_UID (REGNO (SET_DEST (set
))) == INSN_UID (insn
)
276 /* We use regno_last_note_uid so as not to delete the setting
277 of a reg that's used in notes. A subsequent optimization
278 might arrange to use that reg for real. */
279 && REGNO_LAST_NOTE_UID (REGNO (SET_DEST (set
))) == INSN_UID (insn
)
280 && ! side_effects_p (SET_SRC (set
))
281 && ! find_reg_note (insn
, REG_RETVAL
, 0)
282 /* An ADDRESSOF expression can turn into a use of the internal arg
283 pointer, so do not delete the initialization of the internal
284 arg pointer yet. If it is truly dead, flow will delete the
285 initializing insn. */
286 && SET_DEST (set
) != current_function_internal_arg_pointer
)
290 /* Now iterate optimizing jumps until nothing changes over one pass. */
292 old_max_reg
= max_reg_num ();
297 for (insn
= f
; insn
; insn
= next
)
300 rtx temp
, temp1
, temp2
= NULL_RTX
;
301 rtx temp4 ATTRIBUTE_UNUSED
;
303 int this_is_simplejump
, this_is_condjump
;
304 int this_is_condjump_in_parallel
;
306 next
= NEXT_INSN (insn
);
308 /* See if this is a NOTE_INSN_LOOP_BEG followed by an unconditional
309 jump. Try to optimize by duplicating the loop exit test if so.
310 This is only safe immediately after regscan, because it uses
311 the values of regno_first_uid and regno_last_uid. */
312 if (after_regscan
&& GET_CODE (insn
) == NOTE
313 && NOTE_LINE_NUMBER (insn
) == NOTE_INSN_LOOP_BEG
314 && (temp1
= next_nonnote_insn (insn
)) != 0
315 && simplejump_p (temp1
))
317 temp
= PREV_INSN (insn
);
318 if (duplicate_loop_exit_test (insn
))
321 next
= NEXT_INSN (temp
);
326 if (GET_CODE (insn
) != JUMP_INSN
)
329 this_is_simplejump
= simplejump_p (insn
);
330 this_is_condjump
= condjump_p (insn
);
331 this_is_condjump_in_parallel
= condjump_in_parallel_p (insn
);
333 /* Tension the labels in dispatch tables. */
335 if (GET_CODE (PATTERN (insn
)) == ADDR_VEC
)
336 changed
|= tension_vector_labels (PATTERN (insn
), 0);
337 if (GET_CODE (PATTERN (insn
)) == ADDR_DIFF_VEC
)
338 changed
|= tension_vector_labels (PATTERN (insn
), 1);
340 /* See if this jump goes to another jump and redirect if so. */
341 nlabel
= follow_jumps (JUMP_LABEL (insn
));
342 if (nlabel
!= JUMP_LABEL (insn
))
343 changed
|= redirect_jump (insn
, nlabel
);
345 if (! optimize
|| minimal
)
348 /* If a dispatch table always goes to the same place,
349 get rid of it and replace the insn that uses it. */
351 if (GET_CODE (PATTERN (insn
)) == ADDR_VEC
352 || GET_CODE (PATTERN (insn
)) == ADDR_DIFF_VEC
)
355 rtx pat
= PATTERN (insn
);
356 int diff_vec_p
= GET_CODE (PATTERN (insn
)) == ADDR_DIFF_VEC
;
357 int len
= XVECLEN (pat
, diff_vec_p
);
358 rtx dispatch
= prev_real_insn (insn
);
361 for (i
= 0; i
< len
; i
++)
362 if (XEXP (XVECEXP (pat
, diff_vec_p
, i
), 0)
363 != XEXP (XVECEXP (pat
, diff_vec_p
, 0), 0))
368 && GET_CODE (dispatch
) == JUMP_INSN
369 && JUMP_LABEL (dispatch
) != 0
370 /* Don't mess with a casesi insn.
371 XXX according to the comment before computed_jump_p(),
372 all casesi insns should be a parallel of the jump
373 and a USE of a LABEL_REF. */
374 && ! ((set
= single_set (dispatch
)) != NULL
375 && (GET_CODE (SET_SRC (set
)) == IF_THEN_ELSE
))
376 && next_real_insn (JUMP_LABEL (dispatch
)) == insn
)
378 redirect_tablejump (dispatch
,
379 XEXP (XVECEXP (pat
, diff_vec_p
, 0), 0));
384 /* If a jump references the end of the function, try to turn
385 it into a RETURN insn, possibly a conditional one. */
386 if (JUMP_LABEL (insn
) != 0
387 && (next_active_insn (JUMP_LABEL (insn
)) == 0
388 || GET_CODE (PATTERN (next_active_insn (JUMP_LABEL (insn
))))
390 changed
|= redirect_jump (insn
, NULL_RTX
);
392 reallabelprev
= prev_active_insn (JUMP_LABEL (insn
));
394 /* Detect jump to following insn. */
395 if (reallabelprev
== insn
&& this_is_condjump
)
397 next
= next_real_insn (JUMP_LABEL (insn
));
403 /* Detect a conditional jump going to the same place
404 as an immediately following unconditional jump. */
405 else if (this_is_condjump
406 && (temp
= next_active_insn (insn
)) != 0
407 && simplejump_p (temp
)
408 && (next_active_insn (JUMP_LABEL (insn
))
409 == next_active_insn (JUMP_LABEL (temp
))))
411 /* Don't mess up test coverage analysis. */
413 if (flag_test_coverage
&& !reload_completed
)
414 for (temp2
= insn
; temp2
!= temp
; temp2
= NEXT_INSN (temp2
))
415 if (GET_CODE (temp2
) == NOTE
&& NOTE_LINE_NUMBER (temp2
) > 0)
426 /* Detect a conditional jump jumping over an unconditional jump. */
428 else if ((this_is_condjump
|| this_is_condjump_in_parallel
)
429 && ! this_is_simplejump
430 && reallabelprev
!= 0
431 && GET_CODE (reallabelprev
) == JUMP_INSN
432 && prev_active_insn (reallabelprev
) == insn
433 && no_labels_between_p (insn
, reallabelprev
)
434 && simplejump_p (reallabelprev
))
436 /* When we invert the unconditional jump, we will be
437 decrementing the usage count of its old label.
438 Make sure that we don't delete it now because that
439 might cause the following code to be deleted. */
440 rtx prev_uses
= prev_nonnote_insn (reallabelprev
);
441 rtx prev_label
= JUMP_LABEL (insn
);
444 ++LABEL_NUSES (prev_label
);
446 if (invert_jump (insn
, JUMP_LABEL (reallabelprev
)))
448 /* It is very likely that if there are USE insns before
449 this jump, they hold REG_DEAD notes. These REG_DEAD
450 notes are no longer valid due to this optimization,
451 and will cause the life-analysis that following passes
452 (notably delayed-branch scheduling) to think that
453 these registers are dead when they are not.
455 To prevent this trouble, we just remove the USE insns
456 from the insn chain. */
458 while (prev_uses
&& GET_CODE (prev_uses
) == INSN
459 && GET_CODE (PATTERN (prev_uses
)) == USE
)
461 rtx useless
= prev_uses
;
462 prev_uses
= prev_nonnote_insn (prev_uses
);
463 delete_insn (useless
);
466 delete_insn (reallabelprev
);
470 /* We can now safely delete the label if it is unreferenced
471 since the delete_insn above has deleted the BARRIER. */
472 if (prev_label
&& --LABEL_NUSES (prev_label
) == 0)
473 delete_insn (prev_label
);
475 next
= NEXT_INSN (insn
);
478 /* If we have an unconditional jump preceded by a USE, try to put
479 the USE before the target and jump there. This simplifies many
480 of the optimizations below since we don't have to worry about
481 dealing with these USE insns. We only do this if the label
482 being branch to already has the identical USE or if code
483 never falls through to that label. */
485 else if (this_is_simplejump
486 && (temp
= prev_nonnote_insn (insn
)) != 0
487 && GET_CODE (temp
) == INSN
488 && GET_CODE (PATTERN (temp
)) == USE
489 && (temp1
= prev_nonnote_insn (JUMP_LABEL (insn
))) != 0
490 && (GET_CODE (temp1
) == BARRIER
491 || (GET_CODE (temp1
) == INSN
492 && rtx_equal_p (PATTERN (temp
), PATTERN (temp1
))))
493 /* Don't do this optimization if we have a loop containing
494 only the USE instruction, and the loop start label has
495 a usage count of 1. This is because we will redo this
496 optimization everytime through the outer loop, and jump
497 opt will never exit. */
498 && ! ((temp2
= prev_nonnote_insn (temp
)) != 0
499 && temp2
== JUMP_LABEL (insn
)
500 && LABEL_NUSES (temp2
) == 1))
502 if (GET_CODE (temp1
) == BARRIER
)
504 emit_insn_after (PATTERN (temp
), temp1
);
505 temp1
= NEXT_INSN (temp1
);
509 redirect_jump (insn
, get_label_before (temp1
));
510 reallabelprev
= prev_real_insn (temp1
);
512 next
= NEXT_INSN (insn
);
516 /* Detect a conditional jump jumping over an unconditional trap. */
518 && this_is_condjump
&& ! this_is_simplejump
519 && reallabelprev
!= 0
520 && GET_CODE (reallabelprev
) == INSN
521 && GET_CODE (PATTERN (reallabelprev
)) == TRAP_IF
522 && TRAP_CONDITION (PATTERN (reallabelprev
)) == const_true_rtx
523 && prev_active_insn (reallabelprev
) == insn
524 && no_labels_between_p (insn
, reallabelprev
)
525 && (temp2
= get_condition (insn
, &temp4
))
526 && can_reverse_comparison_p (temp2
, insn
))
528 rtx
new = gen_cond_trap (reverse_condition (GET_CODE (temp2
)),
529 XEXP (temp2
, 0), XEXP (temp2
, 1),
530 TRAP_CODE (PATTERN (reallabelprev
)));
534 emit_insn_before (new, temp4
);
535 delete_insn (reallabelprev
);
541 /* Detect a jump jumping to an unconditional trap. */
542 else if (HAVE_trap
&& this_is_condjump
543 && (temp
= next_active_insn (JUMP_LABEL (insn
)))
544 && GET_CODE (temp
) == INSN
545 && GET_CODE (PATTERN (temp
)) == TRAP_IF
546 && (this_is_simplejump
547 || (temp2
= get_condition (insn
, &temp4
))))
549 rtx tc
= TRAP_CONDITION (PATTERN (temp
));
551 if (tc
== const_true_rtx
552 || (! this_is_simplejump
&& rtx_equal_p (temp2
, tc
)))
555 /* Replace an unconditional jump to a trap with a trap. */
556 if (this_is_simplejump
)
558 emit_barrier_after (emit_insn_before (gen_trap (), insn
));
563 new = gen_cond_trap (GET_CODE (temp2
), XEXP (temp2
, 0),
565 TRAP_CODE (PATTERN (temp
)));
568 emit_insn_before (new, temp4
);
574 /* If the trap condition and jump condition are mutually
575 exclusive, redirect the jump to the following insn. */
576 else if (GET_RTX_CLASS (GET_CODE (tc
)) == '<'
577 && ! this_is_simplejump
578 && swap_condition (GET_CODE (temp2
)) == GET_CODE (tc
)
579 && rtx_equal_p (XEXP (tc
, 0), XEXP (temp2
, 0))
580 && rtx_equal_p (XEXP (tc
, 1), XEXP (temp2
, 1))
581 && redirect_jump (insn
, get_label_after (temp
)))
590 /* Now that the jump has been tensioned,
591 try cross jumping: check for identical code
592 before the jump and before its target label. */
594 /* First, cross jumping of conditional jumps: */
596 if (cross_jump
&& condjump_p (insn
))
598 rtx newjpos
, newlpos
;
599 rtx x
= prev_real_insn (JUMP_LABEL (insn
));
601 /* A conditional jump may be crossjumped
602 only if the place it jumps to follows
603 an opposing jump that comes back here. */
605 if (x
!= 0 && ! jump_back_p (x
, insn
))
606 /* We have no opposing jump;
607 cannot cross jump this insn. */
611 /* TARGET is nonzero if it is ok to cross jump
612 to code before TARGET. If so, see if matches. */
614 find_cross_jump (insn
, x
, 2,
619 do_cross_jump (insn
, newjpos
, newlpos
);
620 /* Make the old conditional jump
621 into an unconditional one. */
622 SET_SRC (PATTERN (insn
))
623 = gen_rtx_LABEL_REF (VOIDmode
, JUMP_LABEL (insn
));
624 INSN_CODE (insn
) = -1;
625 emit_barrier_after (insn
);
626 /* Add to jump_chain unless this is a new label
627 whose UID is too large. */
628 if (INSN_UID (JUMP_LABEL (insn
)) < max_jump_chain
)
630 jump_chain
[INSN_UID (insn
)]
631 = jump_chain
[INSN_UID (JUMP_LABEL (insn
))];
632 jump_chain
[INSN_UID (JUMP_LABEL (insn
))] = insn
;
639 /* Cross jumping of unconditional jumps:
640 a few differences. */
642 if (cross_jump
&& simplejump_p (insn
))
644 rtx newjpos
, newlpos
;
649 /* TARGET is nonzero if it is ok to cross jump
650 to code before TARGET. If so, see if matches. */
651 find_cross_jump (insn
, JUMP_LABEL (insn
), 1,
654 /* If cannot cross jump to code before the label,
655 see if we can cross jump to another jump to
657 /* Try each other jump to this label. */
658 if (INSN_UID (JUMP_LABEL (insn
)) < max_uid
)
659 for (target
= jump_chain
[INSN_UID (JUMP_LABEL (insn
))];
660 target
!= 0 && newjpos
== 0;
661 target
= jump_chain
[INSN_UID (target
)])
663 && JUMP_LABEL (target
) == JUMP_LABEL (insn
)
664 /* Ignore TARGET if it's deleted. */
665 && ! INSN_DELETED_P (target
))
666 find_cross_jump (insn
, target
, 2,
671 do_cross_jump (insn
, newjpos
, newlpos
);
677 /* This code was dead in the previous jump.c! */
678 if (cross_jump
&& GET_CODE (PATTERN (insn
)) == RETURN
)
680 /* Return insns all "jump to the same place"
681 so we can cross-jump between any two of them. */
683 rtx newjpos
, newlpos
, target
;
687 /* If cannot cross jump to code before the label,
688 see if we can cross jump to another jump to
690 /* Try each other jump to this label. */
691 for (target
= jump_chain
[0];
692 target
!= 0 && newjpos
== 0;
693 target
= jump_chain
[INSN_UID (target
)])
695 && ! INSN_DELETED_P (target
)
696 && GET_CODE (PATTERN (target
)) == RETURN
)
697 find_cross_jump (insn
, target
, 2,
702 do_cross_jump (insn
, newjpos
, newlpos
);
713 /* Delete extraneous line number notes.
714 Note that two consecutive notes for different lines are not really
715 extraneous. There should be some indication where that line belonged,
716 even if it became empty. */
721 for (insn
= f
; insn
; insn
= NEXT_INSN (insn
))
722 if (GET_CODE (insn
) == NOTE
&& NOTE_LINE_NUMBER (insn
) >= 0)
724 /* Delete this note if it is identical to previous note. */
726 && NOTE_SOURCE_FILE (insn
) == NOTE_SOURCE_FILE (last_note
)
727 && NOTE_LINE_NUMBER (insn
) == NOTE_LINE_NUMBER (last_note
))
737 /* CAN_REACH_END is persistent for each function. Once set it should
738 not be cleared. This is especially true for the case where we
739 delete the NOTE_FUNCTION_END note. CAN_REACH_END is cleared by
740 the front-end before compiling each function. */
741 if (! minimal
&& calculate_can_reach_end (last_insn
, optimize
!= 0))
750 /* Initialize LABEL_NUSES and JUMP_LABEL fields. Delete any REG_LABEL
751 notes whose labels don't occur in the insn any more. Returns the
752 largest INSN_UID found. */
760 for (insn
= f
; insn
; insn
= NEXT_INSN (insn
))
762 if (GET_CODE (insn
) == CODE_LABEL
)
763 LABEL_NUSES (insn
) = (LABEL_PRESERVE_P (insn
) != 0);
764 else if (GET_CODE (insn
) == JUMP_INSN
)
765 JUMP_LABEL (insn
) = 0;
766 else if (GET_CODE (insn
) == INSN
|| GET_CODE (insn
) == CALL_INSN
)
770 for (note
= REG_NOTES (insn
); note
; note
= next
)
772 next
= XEXP (note
, 1);
773 if (REG_NOTE_KIND (note
) == REG_LABEL
774 && ! reg_mentioned_p (XEXP (note
, 0), PATTERN (insn
)))
775 remove_note (insn
, note
);
778 if (INSN_UID (insn
) > largest_uid
)
779 largest_uid
= INSN_UID (insn
);
785 /* Delete insns following barriers, up to next label.
787 Also delete no-op jumps created by gcse. */
790 delete_barrier_successors (f
)
795 for (insn
= f
; insn
;)
797 if (GET_CODE (insn
) == BARRIER
)
799 insn
= NEXT_INSN (insn
);
801 never_reached_warning (insn
);
803 while (insn
!= 0 && GET_CODE (insn
) != CODE_LABEL
)
805 if (GET_CODE (insn
) == NOTE
806 && NOTE_LINE_NUMBER (insn
) != NOTE_INSN_FUNCTION_END
)
807 insn
= NEXT_INSN (insn
);
809 insn
= delete_insn (insn
);
811 /* INSN is now the code_label. */
814 /* Also remove (set (pc) (pc)) insns which can be created by
815 gcse. We eliminate such insns now to avoid having them
816 cause problems later. */
817 else if (GET_CODE (insn
) == JUMP_INSN
818 && GET_CODE (PATTERN (insn
)) == SET
819 && SET_SRC (PATTERN (insn
)) == pc_rtx
820 && SET_DEST (PATTERN (insn
)) == pc_rtx
)
821 insn
= delete_insn (insn
);
824 insn
= NEXT_INSN (insn
);
828 /* Mark the label each jump jumps to.
829 Combine consecutive labels, and count uses of labels.
831 For each label, make a chain (using `jump_chain')
832 of all the *unconditional* jumps that jump to it;
833 also make a chain of all returns.
835 CROSS_JUMP indicates whether we are doing cross jumping
836 and if we are whether we will be paying attention to
837 death notes or not. */
840 mark_all_labels (f
, cross_jump
)
846 for (insn
= f
; insn
; insn
= NEXT_INSN (insn
))
847 if (GET_RTX_CLASS (GET_CODE (insn
)) == 'i')
849 if (GET_CODE (insn
) == CALL_INSN
850 && GET_CODE (PATTERN (insn
)) == CALL_PLACEHOLDER
)
852 mark_all_labels (XEXP (PATTERN (insn
), 0), cross_jump
);
853 mark_all_labels (XEXP (PATTERN (insn
), 1), cross_jump
);
854 mark_all_labels (XEXP (PATTERN (insn
), 2), cross_jump
);
858 mark_jump_label (PATTERN (insn
), insn
, cross_jump
, 0);
859 if (! INSN_DELETED_P (insn
) && GET_CODE (insn
) == JUMP_INSN
)
861 if (JUMP_LABEL (insn
) != 0 && simplejump_p (insn
))
863 jump_chain
[INSN_UID (insn
)]
864 = jump_chain
[INSN_UID (JUMP_LABEL (insn
))];
865 jump_chain
[INSN_UID (JUMP_LABEL (insn
))] = insn
;
867 if (GET_CODE (PATTERN (insn
)) == RETURN
)
869 jump_chain
[INSN_UID (insn
)] = jump_chain
[0];
870 jump_chain
[0] = insn
;
876 /* Delete all labels already not referenced.
877 Also find and return the last insn. */
880 delete_unreferenced_labels (f
)
883 rtx final
= NULL_RTX
;
886 for (insn
= f
; insn
; )
888 if (GET_CODE (insn
) == CODE_LABEL
889 && LABEL_NUSES (insn
) == 0
890 && LABEL_ALTERNATE_NAME (insn
) == NULL
)
891 insn
= delete_insn (insn
);
895 insn
= NEXT_INSN (insn
);
902 /* Delete various simple forms of moves which have no necessary
906 delete_noop_moves (f
)
911 for (insn
= f
; insn
; )
913 next
= NEXT_INSN (insn
);
915 if (GET_CODE (insn
) == INSN
)
917 register rtx body
= PATTERN (insn
);
919 /* Detect and delete no-op move instructions
920 resulting from not allocating a parameter in a register. */
922 if (GET_CODE (body
) == SET
923 && (SET_DEST (body
) == SET_SRC (body
)
924 || (GET_CODE (SET_DEST (body
)) == MEM
925 && GET_CODE (SET_SRC (body
)) == MEM
926 && rtx_equal_p (SET_SRC (body
), SET_DEST (body
))))
927 && ! (GET_CODE (SET_DEST (body
)) == MEM
928 && MEM_VOLATILE_P (SET_DEST (body
)))
929 && ! (GET_CODE (SET_SRC (body
)) == MEM
930 && MEM_VOLATILE_P (SET_SRC (body
))))
931 delete_computation (insn
);
933 /* Detect and ignore no-op move instructions
934 resulting from smart or fortuitous register allocation. */
936 else if (GET_CODE (body
) == SET
)
938 int sreg
= true_regnum (SET_SRC (body
));
939 int dreg
= true_regnum (SET_DEST (body
));
941 if (sreg
== dreg
&& sreg
>= 0)
943 else if (sreg
>= 0 && dreg
>= 0)
946 rtx tem
= find_equiv_reg (NULL_RTX
, insn
, 0,
947 sreg
, NULL_PTR
, dreg
,
948 GET_MODE (SET_SRC (body
)));
951 && GET_MODE (tem
) == GET_MODE (SET_DEST (body
)))
953 /* DREG may have been the target of a REG_DEAD note in
954 the insn which makes INSN redundant. If so, reorg
955 would still think it is dead. So search for such a
956 note and delete it if we find it. */
957 if (! find_regno_note (insn
, REG_UNUSED
, dreg
))
958 for (trial
= prev_nonnote_insn (insn
);
959 trial
&& GET_CODE (trial
) != CODE_LABEL
;
960 trial
= prev_nonnote_insn (trial
))
961 if (find_regno_note (trial
, REG_DEAD
, dreg
))
963 remove_death (dreg
, trial
);
967 /* Deleting insn could lose a death-note for SREG. */
968 if ((trial
= find_regno_note (insn
, REG_DEAD
, sreg
)))
970 /* Change this into a USE so that we won't emit
971 code for it, but still can keep the note. */
973 = gen_rtx_USE (VOIDmode
, XEXP (trial
, 0));
974 INSN_CODE (insn
) = -1;
975 /* Remove all reg notes but the REG_DEAD one. */
976 REG_NOTES (insn
) = trial
;
977 XEXP (trial
, 1) = NULL_RTX
;
983 else if (dreg
>= 0 && CONSTANT_P (SET_SRC (body
))
984 && find_equiv_reg (SET_SRC (body
), insn
, 0, dreg
,
986 GET_MODE (SET_DEST (body
))))
988 /* This handles the case where we have two consecutive
989 assignments of the same constant to pseudos that didn't
990 get a hard reg. Each SET from the constant will be
991 converted into a SET of the spill register and an
992 output reload will be made following it. This produces
993 two loads of the same constant into the same spill
998 /* Look back for a death note for the first reg.
999 If there is one, it is no longer accurate. */
1000 while (in_insn
&& GET_CODE (in_insn
) != CODE_LABEL
)
1002 if ((GET_CODE (in_insn
) == INSN
1003 || GET_CODE (in_insn
) == JUMP_INSN
)
1004 && find_regno_note (in_insn
, REG_DEAD
, dreg
))
1006 remove_death (dreg
, in_insn
);
1009 in_insn
= PREV_INSN (in_insn
);
1012 /* Delete the second load of the value. */
1016 else if (GET_CODE (body
) == PARALLEL
)
1018 /* If each part is a set between two identical registers or
1019 a USE or CLOBBER, delete the insn. */
1023 for (i
= XVECLEN (body
, 0) - 1; i
>= 0; i
--)
1025 tem
= XVECEXP (body
, 0, i
);
1026 if (GET_CODE (tem
) == USE
|| GET_CODE (tem
) == CLOBBER
)
1029 if (GET_CODE (tem
) != SET
1030 || (sreg
= true_regnum (SET_SRC (tem
))) < 0
1031 || (dreg
= true_regnum (SET_DEST (tem
))) < 0
1039 /* Also delete insns to store bit fields if they are no-ops. */
1040 /* Not worth the hair to detect this in the big-endian case. */
1041 else if (! BYTES_BIG_ENDIAN
1042 && GET_CODE (body
) == SET
1043 && GET_CODE (SET_DEST (body
)) == ZERO_EXTRACT
1044 && XEXP (SET_DEST (body
), 2) == const0_rtx
1045 && XEXP (SET_DEST (body
), 0) == SET_SRC (body
)
1046 && ! (GET_CODE (SET_SRC (body
)) == MEM
1047 && MEM_VOLATILE_P (SET_SRC (body
))))
1054 /* See if there is still a NOTE_INSN_FUNCTION_END in this function.
1055 If so indicate that this function can drop off the end by returning
1058 CHECK_DELETED indicates whether we must check if the note being
1059 searched for has the deleted flag set.
1061 DELETE_FINAL_NOTE indicates whether we should delete the note
1065 calculate_can_reach_end (last
, delete_final_note
)
1067 int delete_final_note
;
1072 while (insn
!= NULL_RTX
)
1076 /* One label can follow the end-note: the return label. */
1077 if (GET_CODE (insn
) == CODE_LABEL
&& n_labels
-- > 0)
1079 /* Ordinary insns can follow it if returning a structure. */
1080 else if (GET_CODE (insn
) == INSN
)
1082 /* If machine uses explicit RETURN insns, no epilogue,
1083 then one of them follows the note. */
1084 else if (GET_CODE (insn
) == JUMP_INSN
1085 && GET_CODE (PATTERN (insn
)) == RETURN
)
1087 /* A barrier can follow the return insn. */
1088 else if (GET_CODE (insn
) == BARRIER
)
1090 /* Other kinds of notes can follow also. */
1091 else if (GET_CODE (insn
) == NOTE
1092 && NOTE_LINE_NUMBER (insn
) != NOTE_INSN_FUNCTION_END
)
1098 insn
= PREV_INSN (insn
);
1101 /* See if we backed up to the appropriate type of note. */
1102 if (insn
!= NULL_RTX
1103 && GET_CODE (insn
) == NOTE
1104 && NOTE_LINE_NUMBER (insn
) == NOTE_INSN_FUNCTION_END
)
1106 if (delete_final_note
)
1114 /* LOOP_START is a NOTE_INSN_LOOP_BEG note that is followed by an unconditional
1115 jump. Assume that this unconditional jump is to the exit test code. If
1116 the code is sufficiently simple, make a copy of it before INSN,
1117 followed by a jump to the exit of the loop. Then delete the unconditional
1120 Return 1 if we made the change, else 0.
1122 This is only safe immediately after a regscan pass because it uses the
1123 values of regno_first_uid and regno_last_uid. */
1126 duplicate_loop_exit_test (loop_start
)
1129 rtx insn
, set
, reg
, p
, link
;
1130 rtx copy
= 0, first_copy
= 0;
1132 rtx exitcode
= NEXT_INSN (JUMP_LABEL (next_nonnote_insn (loop_start
)));
1134 int max_reg
= max_reg_num ();
1137 /* Scan the exit code. We do not perform this optimization if any insn:
1141 has a REG_RETVAL or REG_LIBCALL note (hard to adjust)
1142 is a NOTE_INSN_LOOP_BEG because this means we have a nested loop
1143 is a NOTE_INSN_BLOCK_{BEG,END} because duplicating these notes
1146 We also do not do this if we find an insn with ASM_OPERANDS. While
1147 this restriction should not be necessary, copying an insn with
1148 ASM_OPERANDS can confuse asm_noperands in some cases.
1150 Also, don't do this if the exit code is more than 20 insns. */
1152 for (insn
= exitcode
;
1154 && ! (GET_CODE (insn
) == NOTE
1155 && NOTE_LINE_NUMBER (insn
) == NOTE_INSN_LOOP_END
);
1156 insn
= NEXT_INSN (insn
))
1158 switch (GET_CODE (insn
))
1164 /* We could be in front of the wrong NOTE_INSN_LOOP_END if there is
1165 a jump immediately after the loop start that branches outside
1166 the loop but within an outer loop, near the exit test.
1167 If we copied this exit test and created a phony
1168 NOTE_INSN_LOOP_VTOP, this could make instructions immediately
1169 before the exit test look like these could be safely moved
1170 out of the loop even if they actually may be never executed.
1171 This can be avoided by checking here for NOTE_INSN_LOOP_CONT. */
1173 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_LOOP_BEG
1174 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_LOOP_CONT
)
1178 && (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
1179 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
))
1180 /* If we were to duplicate this code, we would not move
1181 the BLOCK notes, and so debugging the moved code would
1182 be difficult. Thus, we only move the code with -O2 or
1189 /* The code below would grossly mishandle REG_WAS_0 notes,
1190 so get rid of them here. */
1191 while ((p
= find_reg_note (insn
, REG_WAS_0
, NULL_RTX
)) != 0)
1192 remove_note (insn
, p
);
1193 if (++num_insns
> 20
1194 || find_reg_note (insn
, REG_RETVAL
, NULL_RTX
)
1195 || find_reg_note (insn
, REG_LIBCALL
, NULL_RTX
))
1203 /* Unless INSN is zero, we can do the optimization. */
1209 /* See if any insn sets a register only used in the loop exit code and
1210 not a user variable. If so, replace it with a new register. */
1211 for (insn
= exitcode
; insn
!= lastexit
; insn
= NEXT_INSN (insn
))
1212 if (GET_CODE (insn
) == INSN
1213 && (set
= single_set (insn
)) != 0
1214 && ((reg
= SET_DEST (set
), GET_CODE (reg
) == REG
)
1215 || (GET_CODE (reg
) == SUBREG
1216 && (reg
= SUBREG_REG (reg
), GET_CODE (reg
) == REG
)))
1217 && REGNO (reg
) >= FIRST_PSEUDO_REGISTER
1218 && REGNO_FIRST_UID (REGNO (reg
)) == INSN_UID (insn
))
1220 for (p
= NEXT_INSN (insn
); p
!= lastexit
; p
= NEXT_INSN (p
))
1221 if (REGNO_LAST_UID (REGNO (reg
)) == INSN_UID (p
))
1226 /* We can do the replacement. Allocate reg_map if this is the
1227 first replacement we found. */
1229 reg_map
= (rtx
*) xcalloc (max_reg
, sizeof (rtx
));
1231 REG_LOOP_TEST_P (reg
) = 1;
1233 reg_map
[REGNO (reg
)] = gen_reg_rtx (GET_MODE (reg
));
1237 /* Now copy each insn. */
1238 for (insn
= exitcode
; insn
!= lastexit
; insn
= NEXT_INSN (insn
))
1240 switch (GET_CODE (insn
))
1243 copy
= emit_barrier_before (loop_start
);
1246 /* Only copy line-number notes. */
1247 if (NOTE_LINE_NUMBER (insn
) >= 0)
1249 copy
= emit_note_before (NOTE_LINE_NUMBER (insn
), loop_start
);
1250 NOTE_SOURCE_FILE (copy
) = NOTE_SOURCE_FILE (insn
);
1255 copy
= emit_insn_before (copy_insn (PATTERN (insn
)), loop_start
);
1257 replace_regs (PATTERN (copy
), reg_map
, max_reg
, 1);
1259 mark_jump_label (PATTERN (copy
), copy
, 0, 0);
1261 /* Copy all REG_NOTES except REG_LABEL since mark_jump_label will
1263 for (link
= REG_NOTES (insn
); link
; link
= XEXP (link
, 1))
1264 if (REG_NOTE_KIND (link
) != REG_LABEL
)
1266 if (GET_CODE (link
) == EXPR_LIST
)
1268 = copy_insn_1 (gen_rtx_EXPR_LIST (REG_NOTE_KIND (link
),
1273 = copy_insn_1 (gen_rtx_INSN_LIST (REG_NOTE_KIND (link
),
1278 if (reg_map
&& REG_NOTES (copy
))
1279 replace_regs (REG_NOTES (copy
), reg_map
, max_reg
, 1);
1283 copy
= emit_jump_insn_before (copy_insn (PATTERN (insn
)), loop_start
);
1285 replace_regs (PATTERN (copy
), reg_map
, max_reg
, 1);
1286 mark_jump_label (PATTERN (copy
), copy
, 0, 0);
1287 if (REG_NOTES (insn
))
1289 REG_NOTES (copy
) = copy_insn_1 (REG_NOTES (insn
));
1291 replace_regs (REG_NOTES (copy
), reg_map
, max_reg
, 1);
1294 /* If this is a simple jump, add it to the jump chain. */
1296 if (INSN_UID (copy
) < max_jump_chain
&& JUMP_LABEL (copy
)
1297 && simplejump_p (copy
))
1299 jump_chain
[INSN_UID (copy
)]
1300 = jump_chain
[INSN_UID (JUMP_LABEL (copy
))];
1301 jump_chain
[INSN_UID (JUMP_LABEL (copy
))] = copy
;
1309 /* Record the first insn we copied. We need it so that we can
1310 scan the copied insns for new pseudo registers. */
1315 /* Now clean up by emitting a jump to the end label and deleting the jump
1316 at the start of the loop. */
1317 if (! copy
|| GET_CODE (copy
) != BARRIER
)
1319 copy
= emit_jump_insn_before (gen_jump (get_label_after (insn
)),
1322 /* Record the first insn we copied. We need it so that we can
1323 scan the copied insns for new pseudo registers. This may not
1324 be strictly necessary since we should have copied at least one
1325 insn above. But I am going to be safe. */
1329 mark_jump_label (PATTERN (copy
), copy
, 0, 0);
1330 if (INSN_UID (copy
) < max_jump_chain
1331 && INSN_UID (JUMP_LABEL (copy
)) < max_jump_chain
)
1333 jump_chain
[INSN_UID (copy
)]
1334 = jump_chain
[INSN_UID (JUMP_LABEL (copy
))];
1335 jump_chain
[INSN_UID (JUMP_LABEL (copy
))] = copy
;
1337 emit_barrier_before (loop_start
);
1340 /* Now scan from the first insn we copied to the last insn we copied
1341 (copy) for new pseudo registers. Do this after the code to jump to
1342 the end label since that might create a new pseudo too. */
1343 reg_scan_update (first_copy
, copy
, max_reg
);
1345 /* Mark the exit code as the virtual top of the converted loop. */
1346 emit_note_before (NOTE_INSN_LOOP_VTOP
, exitcode
);
1348 delete_insn (next_nonnote_insn (loop_start
));
1357 /* Move all block-beg, block-end, loop-beg, loop-cont, loop-vtop, loop-end,
1358 eh-beg, eh-end notes between START and END out before START. Assume that
1359 END is not such a note. START may be such a note. Returns the value
1360 of the new starting insn, which may be different if the original start
1364 squeeze_notes (start
, end
)
1370 for (insn
= start
; insn
!= end
; insn
= next
)
1372 next
= NEXT_INSN (insn
);
1373 if (GET_CODE (insn
) == NOTE
1374 && (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
1375 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
1376 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_LOOP_BEG
1377 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_LOOP_END
1378 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_LOOP_CONT
1379 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_LOOP_VTOP
1380 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_EH_REGION_BEG
1381 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_EH_REGION_END
))
1387 rtx prev
= PREV_INSN (insn
);
1388 PREV_INSN (insn
) = PREV_INSN (start
);
1389 NEXT_INSN (insn
) = start
;
1390 NEXT_INSN (PREV_INSN (insn
)) = insn
;
1391 PREV_INSN (NEXT_INSN (insn
)) = insn
;
1392 NEXT_INSN (prev
) = next
;
1393 PREV_INSN (next
) = prev
;
1401 /* Compare the instructions before insn E1 with those before E2
1402 to find an opportunity for cross jumping.
1403 (This means detecting identical sequences of insns followed by
1404 jumps to the same place, or followed by a label and a jump
1405 to that label, and replacing one with a jump to the other.)
1407 Assume E1 is a jump that jumps to label E2
1408 (that is not always true but it might as well be).
1409 Find the longest possible equivalent sequences
1410 and store the first insns of those sequences into *F1 and *F2.
1411 Store zero there if no equivalent preceding instructions are found.
1413 We give up if we find a label in stream 1.
1414 Actually we could transfer that label into stream 2. */
1417 find_cross_jump (e1
, e2
, minimum
, f1
, f2
)
1422 register rtx i1
= e1
, i2
= e2
;
1423 register rtx p1
, p2
;
1426 rtx last1
= 0, last2
= 0;
1427 rtx afterlast1
= 0, afterlast2
= 0;
1434 i1
= prev_nonnote_insn (i1
);
1436 i2
= PREV_INSN (i2
);
1437 while (i2
&& (GET_CODE (i2
) == NOTE
|| GET_CODE (i2
) == CODE_LABEL
))
1438 i2
= PREV_INSN (i2
);
1443 /* Don't allow the range of insns preceding E1 or E2
1444 to include the other (E2 or E1). */
1445 if (i2
== e1
|| i1
== e2
)
1448 /* If we will get to this code by jumping, those jumps will be
1449 tensioned to go directly to the new label (before I2),
1450 so this cross-jumping won't cost extra. So reduce the minimum. */
1451 if (GET_CODE (i1
) == CODE_LABEL
)
1457 if (i2
== 0 || GET_CODE (i1
) != GET_CODE (i2
))
1460 /* Avoid moving insns across EH regions if either of the insns
1463 && (asynchronous_exceptions
|| GET_CODE (i1
) == CALL_INSN
)
1464 && !in_same_eh_region (i1
, i2
))
1470 /* If this is a CALL_INSN, compare register usage information.
1471 If we don't check this on stack register machines, the two
1472 CALL_INSNs might be merged leaving reg-stack.c with mismatching
1473 numbers of stack registers in the same basic block.
1474 If we don't check this on machines with delay slots, a delay slot may
1475 be filled that clobbers a parameter expected by the subroutine.
1477 ??? We take the simple route for now and assume that if they're
1478 equal, they were constructed identically. */
1480 if (GET_CODE (i1
) == CALL_INSN
1481 && ! rtx_equal_p (CALL_INSN_FUNCTION_USAGE (i1
),
1482 CALL_INSN_FUNCTION_USAGE (i2
)))
1486 /* If cross_jump_death_matters is not 0, the insn's mode
1487 indicates whether or not the insn contains any stack-like
1490 if (!lose
&& cross_jump_death_matters
&& stack_regs_mentioned (i1
))
1492 /* If register stack conversion has already been done, then
1493 death notes must also be compared before it is certain that
1494 the two instruction streams match. */
1497 HARD_REG_SET i1_regset
, i2_regset
;
1499 CLEAR_HARD_REG_SET (i1_regset
);
1500 CLEAR_HARD_REG_SET (i2_regset
);
1502 for (note
= REG_NOTES (i1
); note
; note
= XEXP (note
, 1))
1503 if (REG_NOTE_KIND (note
) == REG_DEAD
1504 && STACK_REG_P (XEXP (note
, 0)))
1505 SET_HARD_REG_BIT (i1_regset
, REGNO (XEXP (note
, 0)));
1507 for (note
= REG_NOTES (i2
); note
; note
= XEXP (note
, 1))
1508 if (REG_NOTE_KIND (note
) == REG_DEAD
1509 && STACK_REG_P (XEXP (note
, 0)))
1510 SET_HARD_REG_BIT (i2_regset
, REGNO (XEXP (note
, 0)));
1512 GO_IF_HARD_REG_EQUAL (i1_regset
, i2_regset
, done
);
1521 /* Don't allow old-style asm or volatile extended asms to be accepted
1522 for cross jumping purposes. It is conceptually correct to allow
1523 them, since cross-jumping preserves the dynamic instruction order
1524 even though it is changing the static instruction order. However,
1525 if an asm is being used to emit an assembler pseudo-op, such as
1526 the MIPS `.set reorder' pseudo-op, then the static instruction order
1527 matters and it must be preserved. */
1528 if (GET_CODE (p1
) == ASM_INPUT
|| GET_CODE (p2
) == ASM_INPUT
1529 || (GET_CODE (p1
) == ASM_OPERANDS
&& MEM_VOLATILE_P (p1
))
1530 || (GET_CODE (p2
) == ASM_OPERANDS
&& MEM_VOLATILE_P (p2
)))
1533 if (lose
|| GET_CODE (p1
) != GET_CODE (p2
)
1534 || ! rtx_renumbered_equal_p (p1
, p2
))
1536 /* The following code helps take care of G++ cleanups. */
1540 if (!lose
&& GET_CODE (p1
) == GET_CODE (p2
)
1541 && ((equiv1
= find_reg_note (i1
, REG_EQUAL
, NULL_RTX
)) != 0
1542 || (equiv1
= find_reg_note (i1
, REG_EQUIV
, NULL_RTX
)) != 0)
1543 && ((equiv2
= find_reg_note (i2
, REG_EQUAL
, NULL_RTX
)) != 0
1544 || (equiv2
= find_reg_note (i2
, REG_EQUIV
, NULL_RTX
)) != 0)
1545 /* If the equivalences are not to a constant, they may
1546 reference pseudos that no longer exist, so we can't
1548 && CONSTANT_P (XEXP (equiv1
, 0))
1549 && rtx_equal_p (XEXP (equiv1
, 0), XEXP (equiv2
, 0)))
1551 rtx s1
= single_set (i1
);
1552 rtx s2
= single_set (i2
);
1553 if (s1
!= 0 && s2
!= 0
1554 && rtx_renumbered_equal_p (SET_DEST (s1
), SET_DEST (s2
)))
1556 validate_change (i1
, &SET_SRC (s1
), XEXP (equiv1
, 0), 1);
1557 validate_change (i2
, &SET_SRC (s2
), XEXP (equiv2
, 0), 1);
1558 if (! rtx_renumbered_equal_p (p1
, p2
))
1560 else if (apply_change_group ())
1565 /* Insns fail to match; cross jumping is limited to the following
1569 /* Don't allow the insn after a compare to be shared by
1570 cross-jumping unless the compare is also shared.
1571 Here, if either of these non-matching insns is a compare,
1572 exclude the following insn from possible cross-jumping. */
1573 if (sets_cc0_p (p1
) || sets_cc0_p (p2
))
1574 last1
= afterlast1
, last2
= afterlast2
, ++minimum
;
1577 /* If cross-jumping here will feed a jump-around-jump
1578 optimization, this jump won't cost extra, so reduce
1580 if (GET_CODE (i1
) == JUMP_INSN
1582 && prev_real_insn (JUMP_LABEL (i1
)) == e1
)
1588 if (GET_CODE (p1
) != USE
&& GET_CODE (p1
) != CLOBBER
)
1590 /* Ok, this insn is potentially includable in a cross-jump here. */
1591 afterlast1
= last1
, afterlast2
= last2
;
1592 last1
= i1
, last2
= i2
, --minimum
;
1596 if (minimum
<= 0 && last1
!= 0 && last1
!= e1
)
1597 *f1
= last1
, *f2
= last2
;
1601 do_cross_jump (insn
, newjpos
, newlpos
)
1602 rtx insn
, newjpos
, newlpos
;
1604 /* Find an existing label at this point
1605 or make a new one if there is none. */
1606 register rtx label
= get_label_before (newlpos
);
1608 /* Make the same jump insn jump to the new point. */
1609 if (GET_CODE (PATTERN (insn
)) == RETURN
)
1611 /* Remove from jump chain of returns. */
1612 delete_from_jump_chain (insn
);
1613 /* Change the insn. */
1614 PATTERN (insn
) = gen_jump (label
);
1615 INSN_CODE (insn
) = -1;
1616 JUMP_LABEL (insn
) = label
;
1617 LABEL_NUSES (label
)++;
1618 /* Add to new the jump chain. */
1619 if (INSN_UID (label
) < max_jump_chain
1620 && INSN_UID (insn
) < max_jump_chain
)
1622 jump_chain
[INSN_UID (insn
)] = jump_chain
[INSN_UID (label
)];
1623 jump_chain
[INSN_UID (label
)] = insn
;
1627 redirect_jump (insn
, label
);
1629 /* Delete the matching insns before the jump. Also, remove any REG_EQUAL
1630 or REG_EQUIV note in the NEWLPOS stream that isn't also present in
1631 the NEWJPOS stream. */
1633 while (newjpos
!= insn
)
1637 for (lnote
= REG_NOTES (newlpos
); lnote
; lnote
= XEXP (lnote
, 1))
1638 if ((REG_NOTE_KIND (lnote
) == REG_EQUAL
1639 || REG_NOTE_KIND (lnote
) == REG_EQUIV
)
1640 && ! find_reg_note (newjpos
, REG_EQUAL
, XEXP (lnote
, 0))
1641 && ! find_reg_note (newjpos
, REG_EQUIV
, XEXP (lnote
, 0)))
1642 remove_note (newlpos
, lnote
);
1644 delete_insn (newjpos
);
1645 newjpos
= next_real_insn (newjpos
);
1646 newlpos
= next_real_insn (newlpos
);
1650 /* Return the label before INSN, or put a new label there. */
1653 get_label_before (insn
)
1658 /* Find an existing label at this point
1659 or make a new one if there is none. */
1660 label
= prev_nonnote_insn (insn
);
1662 if (label
== 0 || GET_CODE (label
) != CODE_LABEL
)
1664 rtx prev
= PREV_INSN (insn
);
1666 label
= gen_label_rtx ();
1667 emit_label_after (label
, prev
);
1668 LABEL_NUSES (label
) = 0;
1673 /* Return the label after INSN, or put a new label there. */
1676 get_label_after (insn
)
1681 /* Find an existing label at this point
1682 or make a new one if there is none. */
1683 label
= next_nonnote_insn (insn
);
1685 if (label
== 0 || GET_CODE (label
) != CODE_LABEL
)
1687 label
= gen_label_rtx ();
1688 emit_label_after (label
, insn
);
1689 LABEL_NUSES (label
) = 0;
1694 /* Return 1 if INSN is a jump that jumps to right after TARGET
1695 only on the condition that TARGET itself would drop through.
1696 Assumes that TARGET is a conditional jump. */
1699 jump_back_p (insn
, target
)
1703 enum rtx_code codei
, codet
;
1705 if (simplejump_p (insn
) || ! condjump_p (insn
)
1706 || simplejump_p (target
)
1707 || target
!= prev_real_insn (JUMP_LABEL (insn
)))
1710 cinsn
= XEXP (SET_SRC (PATTERN (insn
)), 0);
1711 ctarget
= XEXP (SET_SRC (PATTERN (target
)), 0);
1713 codei
= GET_CODE (cinsn
);
1714 codet
= GET_CODE (ctarget
);
1716 if (XEXP (SET_SRC (PATTERN (insn
)), 1) == pc_rtx
)
1718 if (! can_reverse_comparison_p (cinsn
, insn
))
1720 codei
= reverse_condition (codei
);
1723 if (XEXP (SET_SRC (PATTERN (target
)), 2) == pc_rtx
)
1725 if (! can_reverse_comparison_p (ctarget
, target
))
1727 codet
= reverse_condition (codet
);
1730 return (codei
== codet
1731 && rtx_renumbered_equal_p (XEXP (cinsn
, 0), XEXP (ctarget
, 0))
1732 && rtx_renumbered_equal_p (XEXP (cinsn
, 1), XEXP (ctarget
, 1)));
1735 /* Given a comparison, COMPARISON, inside a conditional jump insn, INSN,
1736 return non-zero if it is safe to reverse this comparison. It is if our
1737 floating-point is not IEEE, if this is an NE or EQ comparison, or if
1738 this is known to be an integer comparison. */
1741 can_reverse_comparison_p (comparison
, insn
)
1747 /* If this is not actually a comparison, we can't reverse it. */
1748 if (GET_RTX_CLASS (GET_CODE (comparison
)) != '<')
1751 if (TARGET_FLOAT_FORMAT
!= IEEE_FLOAT_FORMAT
1752 /* If this is an NE comparison, it is safe to reverse it to an EQ
1753 comparison and vice versa, even for floating point. If no operands
1754 are NaNs, the reversal is valid. If some operand is a NaN, EQ is
1755 always false and NE is always true, so the reversal is also valid. */
1757 || GET_CODE (comparison
) == NE
1758 || GET_CODE (comparison
) == EQ
)
1761 arg0
= XEXP (comparison
, 0);
1763 /* Make sure ARG0 is one of the actual objects being compared. If we
1764 can't do this, we can't be sure the comparison can be reversed.
1766 Handle cc0 and a MODE_CC register. */
1767 if ((GET_CODE (arg0
) == REG
&& GET_MODE_CLASS (GET_MODE (arg0
)) == MODE_CC
)
1773 rtx prev
= prev_nonnote_insn (insn
);
1776 /* First see if the condition code mode alone if enough to say we can
1777 reverse the condition. If not, then search backwards for a set of
1778 ARG0. We do not need to check for an insn clobbering it since valid
1779 code will contain set a set with no intervening clobber. But
1780 stop when we reach a label. */
1781 #ifdef REVERSIBLE_CC_MODE
1782 if (GET_MODE_CLASS (GET_MODE (arg0
)) == MODE_CC
1783 && REVERSIBLE_CC_MODE (GET_MODE (arg0
)))
1787 for (prev
= prev_nonnote_insn (insn
);
1788 prev
!= 0 && GET_CODE (prev
) != CODE_LABEL
;
1789 prev
= prev_nonnote_insn (prev
))
1790 if ((set
= single_set (prev
)) != 0
1791 && rtx_equal_p (SET_DEST (set
), arg0
))
1793 arg0
= SET_SRC (set
);
1795 if (GET_CODE (arg0
) == COMPARE
)
1796 arg0
= XEXP (arg0
, 0);
1801 /* We can reverse this if ARG0 is a CONST_INT or if its mode is
1802 not VOIDmode and neither a MODE_CC nor MODE_FLOAT type. */
1803 return (GET_CODE (arg0
) == CONST_INT
1804 || (GET_MODE (arg0
) != VOIDmode
1805 && GET_MODE_CLASS (GET_MODE (arg0
)) != MODE_CC
1806 && GET_MODE_CLASS (GET_MODE (arg0
)) != MODE_FLOAT
));
1809 /* Given an rtx-code for a comparison, return the code for the negated
1810 comparison. If no such code exists, return UNKNOWN.
1812 WATCH OUT! reverse_condition is not safe to use on a jump that might
1813 be acting on the results of an IEEE floating point comparison, because
1814 of the special treatment of non-signaling nans in comparisons.
1815 Use can_reverse_comparison_p to be sure. */
1818 reverse_condition (code
)
1861 /* Similar, but we're allowed to generate unordered comparisons, which
1862 makes it safe for IEEE floating-point. Of course, we have to recognize
1863 that the target will support them too... */
1866 reverse_condition_maybe_unordered (code
)
1869 /* Non-IEEE formats don't have unordered conditions. */
1870 if (TARGET_FLOAT_FORMAT
!= IEEE_FLOAT_FORMAT
)
1871 return reverse_condition (code
);
1917 /* Similar, but return the code when two operands of a comparison are swapped.
1918 This IS safe for IEEE floating-point. */
1921 swap_condition (code
)
1964 /* Given a comparison CODE, return the corresponding unsigned comparison.
1965 If CODE is an equality comparison or already an unsigned comparison,
1966 CODE is returned. */
1969 unsigned_condition (code
)
1996 /* Similarly, return the signed version of a comparison. */
1999 signed_condition (code
)
2026 /* Return non-zero if CODE1 is more strict than CODE2, i.e., if the
2027 truth of CODE1 implies the truth of CODE2. */
2030 comparison_dominates_p (code1
, code2
)
2031 enum rtx_code code1
, code2
;
2039 if (code2
== LE
|| code2
== LEU
|| code2
== GE
|| code2
== GEU
2040 || code2
== ORDERED
)
2045 if (code2
== LE
|| code2
== NE
|| code2
== ORDERED
)
2050 if (code2
== GE
|| code2
== NE
|| code2
== ORDERED
)
2056 if (code2
== ORDERED
)
2061 if (code2
== NE
|| code2
== ORDERED
)
2066 if (code2
== LEU
|| code2
== NE
)
2071 if (code2
== GEU
|| code2
== NE
)
2087 /* Return 1 if INSN is an unconditional jump and nothing else. */
2093 return (GET_CODE (insn
) == JUMP_INSN
2094 && GET_CODE (PATTERN (insn
)) == SET
2095 && GET_CODE (SET_DEST (PATTERN (insn
))) == PC
2096 && GET_CODE (SET_SRC (PATTERN (insn
))) == LABEL_REF
);
2099 /* Return nonzero if INSN is a (possibly) conditional jump
2102 Use this function is depreached, since we need to support
2103 branch and compare insns. Use nontrivial_condjump_p instead
2111 register rtx x
= PATTERN (insn
);
2113 if (GET_CODE (x
) != SET
2114 || GET_CODE (SET_DEST (x
)) != PC
)
2118 if (GET_CODE (x
) == LABEL_REF
)
2120 else return (GET_CODE (x
) == IF_THEN_ELSE
2121 && ((GET_CODE (XEXP (x
, 2)) == PC
2122 && (GET_CODE (XEXP (x
, 1)) == LABEL_REF
2123 || GET_CODE (XEXP (x
, 1)) == RETURN
))
2124 || (GET_CODE (XEXP (x
, 1)) == PC
2125 && (GET_CODE (XEXP (x
, 2)) == LABEL_REF
2126 || GET_CODE (XEXP (x
, 2)) == RETURN
))));
2131 /* Return nonzero if INSN is a (possibly) conditional jump inside a
2134 Use this function is depreached, since we need to support
2135 branch and compare insns. Use any_condjump_p instead
2140 condjump_in_parallel_p (insn
)
2143 register rtx x
= PATTERN (insn
);
2145 if (GET_CODE (x
) != PARALLEL
)
2148 x
= XVECEXP (x
, 0, 0);
2150 if (GET_CODE (x
) != SET
)
2152 if (GET_CODE (SET_DEST (x
)) != PC
)
2154 if (GET_CODE (SET_SRC (x
)) == LABEL_REF
)
2156 if (GET_CODE (SET_SRC (x
)) != IF_THEN_ELSE
)
2158 if (XEXP (SET_SRC (x
), 2) == pc_rtx
2159 && (GET_CODE (XEXP (SET_SRC (x
), 1)) == LABEL_REF
2160 || GET_CODE (XEXP (SET_SRC (x
), 1)) == RETURN
))
2162 if (XEXP (SET_SRC (x
), 1) == pc_rtx
2163 && (GET_CODE (XEXP (SET_SRC (x
), 2)) == LABEL_REF
2164 || GET_CODE (XEXP (SET_SRC (x
), 2)) == RETURN
))
2169 /* Return set of PC if available NULL otherwise. */
2175 if (GET_CODE (insn
) != JUMP_INSN
)
2177 pat
= PATTERN (insn
);
2178 /* The set is allowed to appear eighter as insn pattern or the first in
2179 PARALLEL expression. */
2180 if (GET_CODE (pat
) == SET
&& GET_CODE (SET_DEST (pat
)) == PC
)
2182 if (GET_CODE (pat
) == PARALLEL
)
2184 rtx set
= XVECEXP (pat
, 0, 0);
2185 if (GET_CODE (set
) == SET
&& GET_CODE (SET_DEST (set
)) == PC
)
2191 /* Return true when insn in unconditional jump possibly boundled inside
2194 any_uncondjump_p (insn
)
2197 rtx x
= pc_set (insn
);
2200 if (GET_CODE (SET_SRC (x
)) != LABEL_REF
)
2205 /* Return true when insn is conditional jump. This function work for
2206 instructions containing PC sets in PARALLELs. The instruction may have
2207 various other effects so before removing the jump you must verify
2208 safe_to_remove_jump_p.
2210 Note that unlike condjump_p it returns 0 for unconditionals jumps.
2213 any_condjump_p (insn
)
2216 rtx x
= pc_set (insn
);
2219 if (XEXP (SET_SRC (x
), 2) == pc_rtx
2220 && (GET_CODE (XEXP (SET_SRC (x
), 1)) == LABEL_REF
2221 || GET_CODE (XEXP (SET_SRC (x
), 1)) == RETURN
))
2223 if (XEXP (SET_SRC (x
), 1) == pc_rtx
2224 && (GET_CODE (XEXP (SET_SRC (x
), 2)) == LABEL_REF
2225 || GET_CODE (XEXP (SET_SRC (x
), 2)) == RETURN
))
2231 /* Return true when the condjump is safe to remove. */
2233 safe_to_remove_jump_p (insn
)
2236 /* For non-single set insns we may remove set of the other registers. */
2237 if (!pc_set (insn
) || !single_set (insn
))
2242 /* Return the label of a conditional jump. */
2245 condjump_label (insn
)
2248 register rtx x
= PATTERN (insn
);
2250 if (GET_CODE (x
) == PARALLEL
)
2251 x
= XVECEXP (x
, 0, 0);
2252 if (GET_CODE (x
) != SET
)
2254 if (GET_CODE (SET_DEST (x
)) != PC
)
2257 if (GET_CODE (x
) == LABEL_REF
)
2259 if (GET_CODE (x
) != IF_THEN_ELSE
)
2261 if (XEXP (x
, 2) == pc_rtx
&& GET_CODE (XEXP (x
, 1)) == LABEL_REF
)
2263 if (XEXP (x
, 1) == pc_rtx
&& GET_CODE (XEXP (x
, 2)) == LABEL_REF
)
2268 /* Return true if INSN is a (possibly conditional) return insn. */
2271 returnjump_p_1 (loc
, data
)
2273 void *data ATTRIBUTE_UNUSED
;
2276 return x
&& GET_CODE (x
) == RETURN
;
2283 return for_each_rtx (&PATTERN (insn
), returnjump_p_1
, NULL
);
2286 /* Return true if INSN is a jump that only transfers control and
2295 if (GET_CODE (insn
) != JUMP_INSN
)
2298 set
= single_set (insn
);
2301 if (GET_CODE (SET_DEST (set
)) != PC
)
2303 if (side_effects_p (SET_SRC (set
)))
2311 /* Return 1 if X is an RTX that does nothing but set the condition codes
2312 and CLOBBER or USE registers.
2313 Return -1 if X does explicitly set the condition codes,
2314 but also does other things. */
2318 rtx x ATTRIBUTE_UNUSED
;
2320 if (GET_CODE (x
) == SET
&& SET_DEST (x
) == cc0_rtx
)
2322 if (GET_CODE (x
) == PARALLEL
)
2326 int other_things
= 0;
2327 for (i
= XVECLEN (x
, 0) - 1; i
>= 0; i
--)
2329 if (GET_CODE (XVECEXP (x
, 0, i
)) == SET
2330 && SET_DEST (XVECEXP (x
, 0, i
)) == cc0_rtx
)
2332 else if (GET_CODE (XVECEXP (x
, 0, i
)) == SET
)
2335 return ! sets_cc0
? 0 : other_things
? -1 : 1;
2341 /* Follow any unconditional jump at LABEL;
2342 return the ultimate label reached by any such chain of jumps.
2343 If LABEL is not followed by a jump, return LABEL.
2344 If the chain loops or we can't find end, return LABEL,
2345 since that tells caller to avoid changing the insn.
2347 If RELOAD_COMPLETED is 0, we do not chain across a NOTE_INSN_LOOP_BEG or
2348 a USE or CLOBBER. */
2351 follow_jumps (label
)
2356 register rtx value
= label
;
2361 && (insn
= next_active_insn (value
)) != 0
2362 && GET_CODE (insn
) == JUMP_INSN
2363 && ((JUMP_LABEL (insn
) != 0 && simplejump_p (insn
))
2364 || GET_CODE (PATTERN (insn
)) == RETURN
)
2365 && (next
= NEXT_INSN (insn
))
2366 && GET_CODE (next
) == BARRIER
);
2369 /* Don't chain through the insn that jumps into a loop
2370 from outside the loop,
2371 since that would create multiple loop entry jumps
2372 and prevent loop optimization. */
2374 if (!reload_completed
)
2375 for (tem
= value
; tem
!= insn
; tem
= NEXT_INSN (tem
))
2376 if (GET_CODE (tem
) == NOTE
2377 && (NOTE_LINE_NUMBER (tem
) == NOTE_INSN_LOOP_BEG
2378 /* ??? Optional. Disables some optimizations, but makes
2379 gcov output more accurate with -O. */
2380 || (flag_test_coverage
&& NOTE_LINE_NUMBER (tem
) > 0)))
2383 /* If we have found a cycle, make the insn jump to itself. */
2384 if (JUMP_LABEL (insn
) == label
)
2387 tem
= next_active_insn (JUMP_LABEL (insn
));
2388 if (tem
&& (GET_CODE (PATTERN (tem
)) == ADDR_VEC
2389 || GET_CODE (PATTERN (tem
)) == ADDR_DIFF_VEC
))
2392 value
= JUMP_LABEL (insn
);
2399 /* Assuming that field IDX of X is a vector of label_refs,
2400 replace each of them by the ultimate label reached by it.
2401 Return nonzero if a change is made.
2402 If IGNORE_LOOPS is 0, we do not chain across a NOTE_INSN_LOOP_BEG. */
2405 tension_vector_labels (x
, idx
)
2411 for (i
= XVECLEN (x
, idx
) - 1; i
>= 0; i
--)
2413 register rtx olabel
= XEXP (XVECEXP (x
, idx
, i
), 0);
2414 register rtx nlabel
= follow_jumps (olabel
);
2415 if (nlabel
&& nlabel
!= olabel
)
2417 XEXP (XVECEXP (x
, idx
, i
), 0) = nlabel
;
2418 ++LABEL_NUSES (nlabel
);
2419 if (--LABEL_NUSES (olabel
) == 0)
2420 delete_insn (olabel
);
2427 /* Find all CODE_LABELs referred to in X, and increment their use counts.
2428 If INSN is a JUMP_INSN and there is at least one CODE_LABEL referenced
2429 in INSN, then store one of them in JUMP_LABEL (INSN).
2430 If INSN is an INSN or a CALL_INSN and there is at least one CODE_LABEL
2431 referenced in INSN, add a REG_LABEL note containing that label to INSN.
2432 Also, when there are consecutive labels, canonicalize on the last of them.
2434 Note that two labels separated by a loop-beginning note
2435 must be kept distinct if we have not yet done loop-optimization,
2436 because the gap between them is where loop-optimize
2437 will want to move invariant code to. CROSS_JUMP tells us
2438 that loop-optimization is done with.
2440 Once reload has completed (CROSS_JUMP non-zero), we need not consider
2441 two labels distinct if they are separated by only USE or CLOBBER insns. */
2444 mark_jump_label (x
, insn
, cross_jump
, in_mem
)
2450 register RTX_CODE code
= GET_CODE (x
);
2452 register const char *fmt
;
2474 /* If this is a constant-pool reference, see if it is a label. */
2475 if (CONSTANT_POOL_ADDRESS_P (x
))
2476 mark_jump_label (get_pool_constant (x
), insn
, cross_jump
, in_mem
);
2481 rtx label
= XEXP (x
, 0);
2486 /* Ignore remaining references to unreachable labels that
2487 have been deleted. */
2488 if (GET_CODE (label
) == NOTE
2489 && NOTE_LINE_NUMBER (label
) == NOTE_INSN_DELETED_LABEL
)
2492 if (GET_CODE (label
) != CODE_LABEL
)
2495 /* Ignore references to labels of containing functions. */
2496 if (LABEL_REF_NONLOCAL_P (x
))
2499 /* If there are other labels following this one,
2500 replace it with the last of the consecutive labels. */
2501 for (next
= NEXT_INSN (label
); next
; next
= NEXT_INSN (next
))
2503 if (GET_CODE (next
) == CODE_LABEL
)
2505 else if (cross_jump
&& GET_CODE (next
) == INSN
2506 && (GET_CODE (PATTERN (next
)) == USE
2507 || GET_CODE (PATTERN (next
)) == CLOBBER
))
2509 else if (GET_CODE (next
) != NOTE
)
2511 else if (! cross_jump
2512 && (NOTE_LINE_NUMBER (next
) == NOTE_INSN_LOOP_BEG
2513 || NOTE_LINE_NUMBER (next
) == NOTE_INSN_FUNCTION_END
2514 /* ??? Optional. Disables some optimizations, but
2515 makes gcov output more accurate with -O. */
2516 || (flag_test_coverage
&& NOTE_LINE_NUMBER (next
) > 0)))
2520 XEXP (x
, 0) = label
;
2521 if (! insn
|| ! INSN_DELETED_P (insn
))
2522 ++LABEL_NUSES (label
);
2526 if (GET_CODE (insn
) == JUMP_INSN
)
2527 JUMP_LABEL (insn
) = label
;
2529 /* If we've changed OLABEL and we had a REG_LABEL note
2530 for it, update it as well. */
2531 else if (label
!= olabel
2532 && (note
= find_reg_note (insn
, REG_LABEL
, olabel
)) != 0)
2533 XEXP (note
, 0) = label
;
2535 /* Otherwise, add a REG_LABEL note for LABEL unless there already
2537 else if (! find_reg_note (insn
, REG_LABEL
, label
))
2539 /* This code used to ignore labels which refered to dispatch
2540 tables to avoid flow.c generating worse code.
2542 However, in the presense of global optimizations like
2543 gcse which call find_basic_blocks without calling
2544 life_analysis, not recording such labels will lead
2545 to compiler aborts because of inconsistencies in the
2546 flow graph. So we go ahead and record the label.
2548 It may also be the case that the optimization argument
2549 is no longer valid because of the more accurate cfg
2550 we build in find_basic_blocks -- it no longer pessimizes
2551 code when it finds a REG_LABEL note. */
2552 REG_NOTES (insn
) = gen_rtx_INSN_LIST (REG_LABEL
, label
,
2559 /* Do walk the labels in a vector, but not the first operand of an
2560 ADDR_DIFF_VEC. Don't set the JUMP_LABEL of a vector. */
2563 if (! INSN_DELETED_P (insn
))
2565 int eltnum
= code
== ADDR_DIFF_VEC
? 1 : 0;
2567 for (i
= 0; i
< XVECLEN (x
, eltnum
); i
++)
2568 mark_jump_label (XVECEXP (x
, eltnum
, i
), NULL_RTX
,
2569 cross_jump
, in_mem
);
2577 fmt
= GET_RTX_FORMAT (code
);
2578 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
2581 mark_jump_label (XEXP (x
, i
), insn
, cross_jump
, in_mem
);
2582 else if (fmt
[i
] == 'E')
2585 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
2586 mark_jump_label (XVECEXP (x
, i
, j
), insn
, cross_jump
, in_mem
);
2591 /* If all INSN does is set the pc, delete it,
2592 and delete the insn that set the condition codes for it
2593 if that's what the previous thing was. */
2599 register rtx set
= single_set (insn
);
2601 if (set
&& GET_CODE (SET_DEST (set
)) == PC
)
2602 delete_computation (insn
);
2605 /* Verify INSN is a BARRIER and delete it. */
2608 delete_barrier (insn
)
2611 if (GET_CODE (insn
) != BARRIER
)
2617 /* Recursively delete prior insns that compute the value (used only by INSN
2618 which the caller is deleting) stored in the register mentioned by NOTE
2619 which is a REG_DEAD note associated with INSN. */
2622 delete_prior_computation (note
, insn
)
2627 rtx reg
= XEXP (note
, 0);
2629 for (our_prev
= prev_nonnote_insn (insn
);
2630 our_prev
&& (GET_CODE (our_prev
) == INSN
2631 || GET_CODE (our_prev
) == CALL_INSN
);
2632 our_prev
= prev_nonnote_insn (our_prev
))
2634 rtx pat
= PATTERN (our_prev
);
2636 /* If we reach a CALL which is not calling a const function
2637 or the callee pops the arguments, then give up. */
2638 if (GET_CODE (our_prev
) == CALL_INSN
2639 && (! CONST_CALL_P (our_prev
)
2640 || GET_CODE (pat
) != SET
|| GET_CODE (SET_SRC (pat
)) != CALL
))
2643 /* If we reach a SEQUENCE, it is too complex to try to
2644 do anything with it, so give up. */
2645 if (GET_CODE (pat
) == SEQUENCE
)
2648 if (GET_CODE (pat
) == USE
2649 && GET_CODE (XEXP (pat
, 0)) == INSN
)
2650 /* reorg creates USEs that look like this. We leave them
2651 alone because reorg needs them for its own purposes. */
2654 if (reg_set_p (reg
, pat
))
2656 if (side_effects_p (pat
) && GET_CODE (our_prev
) != CALL_INSN
)
2659 if (GET_CODE (pat
) == PARALLEL
)
2661 /* If we find a SET of something else, we can't
2666 for (i
= 0; i
< XVECLEN (pat
, 0); i
++)
2668 rtx part
= XVECEXP (pat
, 0, i
);
2670 if (GET_CODE (part
) == SET
2671 && SET_DEST (part
) != reg
)
2675 if (i
== XVECLEN (pat
, 0))
2676 delete_computation (our_prev
);
2678 else if (GET_CODE (pat
) == SET
2679 && GET_CODE (SET_DEST (pat
)) == REG
)
2681 int dest_regno
= REGNO (SET_DEST (pat
));
2683 = dest_regno
+ (dest_regno
< FIRST_PSEUDO_REGISTER
2684 ? HARD_REGNO_NREGS (dest_regno
,
2685 GET_MODE (SET_DEST (pat
))) : 1);
2686 int regno
= REGNO (reg
);
2687 int endregno
= regno
+ (regno
< FIRST_PSEUDO_REGISTER
2688 ? HARD_REGNO_NREGS (regno
, GET_MODE (reg
)) : 1);
2690 if (dest_regno
>= regno
2691 && dest_endregno
<= endregno
)
2692 delete_computation (our_prev
);
2694 /* We may have a multi-word hard register and some, but not
2695 all, of the words of the register are needed in subsequent
2696 insns. Write REG_UNUSED notes for those parts that were not
2698 else if (dest_regno
<= regno
2699 && dest_endregno
>= endregno
)
2703 REG_NOTES (our_prev
)
2704 = gen_rtx_EXPR_LIST (REG_UNUSED
, reg
, REG_NOTES (our_prev
));
2706 for (i
= dest_regno
; i
< dest_endregno
; i
++)
2707 if (! find_regno_note (our_prev
, REG_UNUSED
, i
))
2710 if (i
== dest_endregno
)
2711 delete_computation (our_prev
);
2718 /* If PAT references the register that dies here, it is an
2719 additional use. Hence any prior SET isn't dead. However, this
2720 insn becomes the new place for the REG_DEAD note. */
2721 if (reg_overlap_mentioned_p (reg
, pat
))
2723 XEXP (note
, 1) = REG_NOTES (our_prev
);
2724 REG_NOTES (our_prev
) = note
;
2730 /* Delete INSN and recursively delete insns that compute values used only
2731 by INSN. This uses the REG_DEAD notes computed during flow analysis.
2732 If we are running before flow.c, we need do nothing since flow.c will
2733 delete dead code. We also can't know if the registers being used are
2734 dead or not at this point.
2736 Otherwise, look at all our REG_DEAD notes. If a previous insn does
2737 nothing other than set a register that dies in this insn, we can delete
2740 On machines with CC0, if CC0 is used in this insn, we may be able to
2741 delete the insn that set it. */
2744 delete_computation (insn
)
2751 if (reg_referenced_p (cc0_rtx
, PATTERN (insn
)))
2753 rtx prev
= prev_nonnote_insn (insn
);
2754 /* We assume that at this stage
2755 CC's are always set explicitly
2756 and always immediately before the jump that
2757 will use them. So if the previous insn
2758 exists to set the CC's, delete it
2759 (unless it performs auto-increments, etc.). */
2760 if (prev
&& GET_CODE (prev
) == INSN
2761 && sets_cc0_p (PATTERN (prev
)))
2763 if (sets_cc0_p (PATTERN (prev
)) > 0
2764 && ! side_effects_p (PATTERN (prev
)))
2765 delete_computation (prev
);
2767 /* Otherwise, show that cc0 won't be used. */
2768 REG_NOTES (prev
) = gen_rtx_EXPR_LIST (REG_UNUSED
,
2769 cc0_rtx
, REG_NOTES (prev
));
2774 #ifdef INSN_SCHEDULING
2775 /* ?!? The schedulers do not keep REG_DEAD notes accurate after
2776 reload has completed. The schedulers need to be fixed. Until
2777 they are, we must not rely on the death notes here. */
2778 if (reload_completed
&& flag_schedule_insns_after_reload
)
2785 /* The REG_DEAD note may have been omitted for a register
2786 which is both set and used by the insn. */
2787 set
= single_set (insn
);
2788 if (set
&& GET_CODE (SET_DEST (set
)) == REG
)
2790 int dest_regno
= REGNO (SET_DEST (set
));
2792 = dest_regno
+ (dest_regno
< FIRST_PSEUDO_REGISTER
2793 ? HARD_REGNO_NREGS (dest_regno
,
2794 GET_MODE (SET_DEST (set
))) : 1);
2797 for (i
= dest_regno
; i
< dest_endregno
; i
++)
2799 if (! refers_to_regno_p (i
, i
+ 1, SET_SRC (set
), NULL_PTR
)
2800 || find_regno_note (insn
, REG_DEAD
, i
))
2803 note
= gen_rtx_EXPR_LIST (REG_DEAD
, (i
< FIRST_PSEUDO_REGISTER
2804 ? gen_rtx_REG (reg_raw_mode
[i
], i
)
2805 : SET_DEST (set
)), NULL_RTX
);
2806 delete_prior_computation (note
, insn
);
2810 for (note
= REG_NOTES (insn
); note
; note
= next
)
2812 next
= XEXP (note
, 1);
2814 if (REG_NOTE_KIND (note
) != REG_DEAD
2815 /* Verify that the REG_NOTE is legitimate. */
2816 || GET_CODE (XEXP (note
, 0)) != REG
)
2819 delete_prior_computation (note
, insn
);
2825 /* Delete insn INSN from the chain of insns and update label ref counts.
2826 May delete some following insns as a consequence; may even delete
2827 a label elsewhere and insns that follow it.
2829 Returns the first insn after INSN that was not deleted. */
2835 register rtx next
= NEXT_INSN (insn
);
2836 register rtx prev
= PREV_INSN (insn
);
2837 register int was_code_label
= (GET_CODE (insn
) == CODE_LABEL
);
2838 register int dont_really_delete
= 0;
2840 while (next
&& INSN_DELETED_P (next
))
2841 next
= NEXT_INSN (next
);
2843 /* This insn is already deleted => return first following nondeleted. */
2844 if (INSN_DELETED_P (insn
))
2848 remove_node_from_expr_list (insn
, &nonlocal_goto_handler_labels
);
2850 /* Don't delete user-declared labels. When optimizing, convert them
2851 to special NOTEs instead. When not optimizing, leave them alone. */
2852 if (was_code_label
&& LABEL_NAME (insn
) != 0)
2855 dont_really_delete
= 1;
2856 else if (! dont_really_delete
)
2858 const char *name
= LABEL_NAME (insn
);
2859 PUT_CODE (insn
, NOTE
);
2860 NOTE_LINE_NUMBER (insn
) = NOTE_INSN_DELETED_LABEL
;
2861 NOTE_SOURCE_FILE (insn
) = name
;
2862 dont_really_delete
= 1;
2866 /* Mark this insn as deleted. */
2867 INSN_DELETED_P (insn
) = 1;
2869 /* If this is an unconditional jump, delete it from the jump chain. */
2870 if (simplejump_p (insn
))
2871 delete_from_jump_chain (insn
);
2873 /* If instruction is followed by a barrier,
2874 delete the barrier too. */
2876 if (next
!= 0 && GET_CODE (next
) == BARRIER
)
2878 INSN_DELETED_P (next
) = 1;
2879 next
= NEXT_INSN (next
);
2882 /* Patch out INSN (and the barrier if any) */
2884 if (! dont_really_delete
)
2888 NEXT_INSN (prev
) = next
;
2889 if (GET_CODE (prev
) == INSN
&& GET_CODE (PATTERN (prev
)) == SEQUENCE
)
2890 NEXT_INSN (XVECEXP (PATTERN (prev
), 0,
2891 XVECLEN (PATTERN (prev
), 0) - 1)) = next
;
2896 PREV_INSN (next
) = prev
;
2897 if (GET_CODE (next
) == INSN
&& GET_CODE (PATTERN (next
)) == SEQUENCE
)
2898 PREV_INSN (XVECEXP (PATTERN (next
), 0, 0)) = prev
;
2901 if (prev
&& NEXT_INSN (prev
) == 0)
2902 set_last_insn (prev
);
2905 /* If deleting a jump, decrement the count of the label,
2906 and delete the label if it is now unused. */
2908 if (GET_CODE (insn
) == JUMP_INSN
&& JUMP_LABEL (insn
))
2910 rtx lab
= JUMP_LABEL (insn
), lab_next
;
2912 if (--LABEL_NUSES (lab
) == 0)
2914 /* This can delete NEXT or PREV,
2915 either directly if NEXT is JUMP_LABEL (INSN),
2916 or indirectly through more levels of jumps. */
2919 /* I feel a little doubtful about this loop,
2920 but I see no clean and sure alternative way
2921 to find the first insn after INSN that is not now deleted.
2922 I hope this works. */
2923 while (next
&& INSN_DELETED_P (next
))
2924 next
= NEXT_INSN (next
);
2927 else if ((lab_next
= next_nonnote_insn (lab
)) != NULL
2928 && GET_CODE (lab_next
) == JUMP_INSN
2929 && (GET_CODE (PATTERN (lab_next
)) == ADDR_VEC
2930 || GET_CODE (PATTERN (lab_next
)) == ADDR_DIFF_VEC
))
2932 /* If we're deleting the tablejump, delete the dispatch table.
2933 We may not be able to kill the label immediately preceeding
2934 just yet, as it might be referenced in code leading up to
2936 delete_insn (lab_next
);
2940 /* Likewise if we're deleting a dispatch table. */
2942 if (GET_CODE (insn
) == JUMP_INSN
2943 && (GET_CODE (PATTERN (insn
)) == ADDR_VEC
2944 || GET_CODE (PATTERN (insn
)) == ADDR_DIFF_VEC
))
2946 rtx pat
= PATTERN (insn
);
2947 int i
, diff_vec_p
= GET_CODE (pat
) == ADDR_DIFF_VEC
;
2948 int len
= XVECLEN (pat
, diff_vec_p
);
2950 for (i
= 0; i
< len
; i
++)
2951 if (--LABEL_NUSES (XEXP (XVECEXP (pat
, diff_vec_p
, i
), 0)) == 0)
2952 delete_insn (XEXP (XVECEXP (pat
, diff_vec_p
, i
), 0));
2953 while (next
&& INSN_DELETED_P (next
))
2954 next
= NEXT_INSN (next
);
2958 while (prev
&& (INSN_DELETED_P (prev
) || GET_CODE (prev
) == NOTE
))
2959 prev
= PREV_INSN (prev
);
2961 /* If INSN was a label and a dispatch table follows it,
2962 delete the dispatch table. The tablejump must have gone already.
2963 It isn't useful to fall through into a table. */
2966 && NEXT_INSN (insn
) != 0
2967 && GET_CODE (NEXT_INSN (insn
)) == JUMP_INSN
2968 && (GET_CODE (PATTERN (NEXT_INSN (insn
))) == ADDR_VEC
2969 || GET_CODE (PATTERN (NEXT_INSN (insn
))) == ADDR_DIFF_VEC
))
2970 next
= delete_insn (NEXT_INSN (insn
));
2972 /* If INSN was a label, delete insns following it if now unreachable. */
2974 if (was_code_label
&& prev
&& GET_CODE (prev
) == BARRIER
)
2976 register RTX_CODE code
;
2978 && (GET_RTX_CLASS (code
= GET_CODE (next
)) == 'i'
2979 || code
== NOTE
|| code
== BARRIER
2980 || (code
== CODE_LABEL
&& INSN_DELETED_P (next
))))
2983 && NOTE_LINE_NUMBER (next
) != NOTE_INSN_FUNCTION_END
)
2984 next
= NEXT_INSN (next
);
2985 /* Keep going past other deleted labels to delete what follows. */
2986 else if (code
== CODE_LABEL
&& INSN_DELETED_P (next
))
2987 next
= NEXT_INSN (next
);
2989 /* Note: if this deletes a jump, it can cause more
2990 deletion of unreachable code, after a different label.
2991 As long as the value from this recursive call is correct,
2992 this invocation functions correctly. */
2993 next
= delete_insn (next
);
3000 /* Advance from INSN till reaching something not deleted
3001 then return that. May return INSN itself. */
3004 next_nondeleted_insn (insn
)
3007 while (INSN_DELETED_P (insn
))
3008 insn
= NEXT_INSN (insn
);
3012 /* Delete a range of insns from FROM to TO, inclusive.
3013 This is for the sake of peephole optimization, so assume
3014 that whatever these insns do will still be done by a new
3015 peephole insn that will replace them. */
3018 delete_for_peephole (from
, to
)
3019 register rtx from
, to
;
3021 register rtx insn
= from
;
3025 register rtx next
= NEXT_INSN (insn
);
3026 register rtx prev
= PREV_INSN (insn
);
3028 if (GET_CODE (insn
) != NOTE
)
3030 INSN_DELETED_P (insn
) = 1;
3032 /* Patch this insn out of the chain. */
3033 /* We don't do this all at once, because we
3034 must preserve all NOTEs. */
3036 NEXT_INSN (prev
) = next
;
3039 PREV_INSN (next
) = prev
;
3047 /* Note that if TO is an unconditional jump
3048 we *do not* delete the BARRIER that follows,
3049 since the peephole that replaces this sequence
3050 is also an unconditional jump in that case. */
3053 /* We have determined that INSN is never reached, and are about to
3054 delete it. Print a warning if the user asked for one.
3056 To try to make this warning more useful, this should only be called
3057 once per basic block not reached, and it only warns when the basic
3058 block contains more than one line from the current function, and
3059 contains at least one operation. CSE and inlining can duplicate insns,
3060 so it's possible to get spurious warnings from this. */
3063 never_reached_warning (avoided_insn
)
3067 rtx a_line_note
= NULL
;
3068 int two_avoided_lines
= 0;
3069 int contains_insn
= 0;
3071 if (! warn_notreached
)
3074 /* Scan forwards, looking at LINE_NUMBER notes, until
3075 we hit a LABEL or we run out of insns. */
3077 for (insn
= avoided_insn
; insn
!= NULL
; insn
= NEXT_INSN (insn
))
3079 if (GET_CODE (insn
) == CODE_LABEL
)
3081 else if (GET_CODE (insn
) == NOTE
/* A line number note? */
3082 && NOTE_LINE_NUMBER (insn
) >= 0)
3084 if (a_line_note
== NULL
)
3087 two_avoided_lines
|= (NOTE_LINE_NUMBER (a_line_note
)
3088 != NOTE_LINE_NUMBER (insn
));
3090 else if (GET_RTX_CLASS (GET_CODE (insn
)) == 'i')
3093 if (two_avoided_lines
&& contains_insn
)
3094 warning_with_file_and_line (NOTE_SOURCE_FILE (a_line_note
),
3095 NOTE_LINE_NUMBER (a_line_note
),
3096 "will never be executed");
3099 /* Throughout LOC, redirect OLABEL to NLABEL. Treat null OLABEL or
3100 NLABEL as a return. Accrue modifications into the change group. */
3103 redirect_exp_1 (loc
, olabel
, nlabel
, insn
)
3108 register rtx x
= *loc
;
3109 register RTX_CODE code
= GET_CODE (x
);
3111 register const char *fmt
;
3113 if (code
== LABEL_REF
)
3115 if (XEXP (x
, 0) == olabel
)
3119 n
= gen_rtx_LABEL_REF (VOIDmode
, nlabel
);
3121 n
= gen_rtx_RETURN (VOIDmode
);
3123 validate_change (insn
, loc
, n
, 1);
3127 else if (code
== RETURN
&& olabel
== 0)
3129 x
= gen_rtx_LABEL_REF (VOIDmode
, nlabel
);
3130 if (loc
== &PATTERN (insn
))
3131 x
= gen_rtx_SET (VOIDmode
, pc_rtx
, x
);
3132 validate_change (insn
, loc
, x
, 1);
3136 if (code
== SET
&& nlabel
== 0 && SET_DEST (x
) == pc_rtx
3137 && GET_CODE (SET_SRC (x
)) == LABEL_REF
3138 && XEXP (SET_SRC (x
), 0) == olabel
)
3140 validate_change (insn
, loc
, gen_rtx_RETURN (VOIDmode
), 1);
3144 fmt
= GET_RTX_FORMAT (code
);
3145 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
3148 redirect_exp_1 (&XEXP (x
, i
), olabel
, nlabel
, insn
);
3149 else if (fmt
[i
] == 'E')
3152 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
3153 redirect_exp_1 (&XVECEXP (x
, i
, j
), olabel
, nlabel
, insn
);
3158 /* Similar, but apply the change group and report success or failure. */
3161 redirect_exp (loc
, olabel
, nlabel
, insn
)
3166 redirect_exp_1 (loc
, olabel
, nlabel
, insn
);
3167 if (num_validated_changes () == 0)
3170 return apply_change_group ();
3173 /* Make JUMP go to NLABEL instead of where it jumps now. Accrue
3174 the modifications into the change group. Return false if we did
3175 not see how to do that. */
3178 redirect_jump_1 (jump
, nlabel
)
3181 int ochanges
= num_validated_changes ();
3182 redirect_exp_1 (&PATTERN (jump
), JUMP_LABEL (jump
), nlabel
, jump
);
3183 return num_validated_changes () > ochanges
;
3186 /* Make JUMP go to NLABEL instead of where it jumps now. If the old
3187 jump target label is unused as a result, it and the code following
3190 If NLABEL is zero, we are to turn the jump into a (possibly conditional)
3193 The return value will be 1 if the change was made, 0 if it wasn't
3194 (this can only occur for NLABEL == 0). */
3197 redirect_jump (jump
, nlabel
)
3200 register rtx olabel
= JUMP_LABEL (jump
);
3202 if (nlabel
== olabel
)
3205 if (! redirect_exp (&PATTERN (jump
), olabel
, nlabel
, jump
))
3208 /* If this is an unconditional branch, delete it from the jump_chain of
3209 OLABEL and add it to the jump_chain of NLABEL (assuming both labels
3210 have UID's in range and JUMP_CHAIN is valid). */
3211 if (jump_chain
&& (simplejump_p (jump
)
3212 || GET_CODE (PATTERN (jump
)) == RETURN
))
3214 int label_index
= nlabel
? INSN_UID (nlabel
) : 0;
3216 delete_from_jump_chain (jump
);
3217 if (label_index
< max_jump_chain
3218 && INSN_UID (jump
) < max_jump_chain
)
3220 jump_chain
[INSN_UID (jump
)] = jump_chain
[label_index
];
3221 jump_chain
[label_index
] = jump
;
3225 JUMP_LABEL (jump
) = nlabel
;
3227 ++LABEL_NUSES (nlabel
);
3229 /* If we're eliding the jump over exception cleanups at the end of a
3230 function, move the function end note so that -Wreturn-type works. */
3231 if (olabel
&& NEXT_INSN (olabel
)
3232 && GET_CODE (NEXT_INSN (olabel
)) == NOTE
3233 && NOTE_LINE_NUMBER (NEXT_INSN (olabel
)) == NOTE_INSN_FUNCTION_END
)
3234 emit_note_after (NOTE_INSN_FUNCTION_END
, nlabel
);
3236 if (olabel
&& --LABEL_NUSES (olabel
) == 0)
3237 delete_insn (olabel
);
3242 /* Invert the jump condition of rtx X contained in jump insn, INSN.
3243 Accrue the modifications into the change group. */
3246 invert_exp_1 (x
, insn
)
3250 register RTX_CODE code
;
3252 register const char *fmt
;
3254 code
= GET_CODE (x
);
3256 if (code
== IF_THEN_ELSE
)
3258 register rtx comp
= XEXP (x
, 0);
3261 /* We can do this in two ways: The preferable way, which can only
3262 be done if this is not an integer comparison, is to reverse
3263 the comparison code. Otherwise, swap the THEN-part and ELSE-part
3264 of the IF_THEN_ELSE. If we can't do either, fail. */
3266 if (can_reverse_comparison_p (comp
, insn
))
3268 validate_change (insn
, &XEXP (x
, 0),
3269 gen_rtx_fmt_ee (reverse_condition (GET_CODE (comp
)),
3270 GET_MODE (comp
), XEXP (comp
, 0),
3277 validate_change (insn
, &XEXP (x
, 1), XEXP (x
, 2), 1);
3278 validate_change (insn
, &XEXP (x
, 2), tem
, 1);
3282 fmt
= GET_RTX_FORMAT (code
);
3283 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
3286 invert_exp_1 (XEXP (x
, i
), insn
);
3287 else if (fmt
[i
] == 'E')
3290 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
3291 invert_exp_1 (XVECEXP (x
, i
, j
), insn
);
3296 /* Invert the jump condition of rtx X contained in jump insn, INSN.
3298 Return 1 if we can do so, 0 if we cannot find a way to do so that
3299 matches a pattern. */
3302 invert_exp (x
, insn
)
3306 invert_exp_1 (x
, insn
);
3307 if (num_validated_changes () == 0)
3310 return apply_change_group ();
3313 /* Invert the condition of the jump JUMP, and make it jump to label
3314 NLABEL instead of where it jumps now. Accrue changes into the
3315 change group. Return false if we didn't see how to perform the
3316 inversion and redirection. */
3319 invert_jump_1 (jump
, nlabel
)
3324 ochanges
= num_validated_changes ();
3325 invert_exp_1 (PATTERN (jump
), jump
);
3326 if (num_validated_changes () == ochanges
)
3329 return redirect_jump_1 (jump
, nlabel
);
3332 /* Invert the condition of the jump JUMP, and make it jump to label
3333 NLABEL instead of where it jumps now. Return true if successful. */
3336 invert_jump (jump
, nlabel
)
3339 /* We have to either invert the condition and change the label or
3340 do neither. Either operation could fail. We first try to invert
3341 the jump. If that succeeds, we try changing the label. If that fails,
3342 we invert the jump back to what it was. */
3344 if (! invert_exp (PATTERN (jump
), jump
))
3347 if (redirect_jump (jump
, nlabel
))
3349 /* An inverted jump means that a probability taken becomes a
3350 probability not taken. Subtract the branch probability from the
3351 probability base to convert it back to a taken probability. */
3353 rtx note
= find_reg_note (jump
, REG_BR_PROB
, NULL_RTX
);
3355 XEXP (note
, 0) = GEN_INT (REG_BR_PROB_BASE
- INTVAL (XEXP (note
, 0)));
3360 if (! invert_exp (PATTERN (jump
), jump
))
3361 /* This should just be putting it back the way it was. */
3367 /* Delete the instruction JUMP from any jump chain it might be on. */
3370 delete_from_jump_chain (jump
)
3374 rtx olabel
= JUMP_LABEL (jump
);
3376 /* Handle unconditional jumps. */
3377 if (jump_chain
&& olabel
!= 0
3378 && INSN_UID (olabel
) < max_jump_chain
3379 && simplejump_p (jump
))
3380 index
= INSN_UID (olabel
);
3381 /* Handle return insns. */
3382 else if (jump_chain
&& GET_CODE (PATTERN (jump
)) == RETURN
)
3386 if (jump_chain
[index
] == jump
)
3387 jump_chain
[index
] = jump_chain
[INSN_UID (jump
)];
3392 for (insn
= jump_chain
[index
];
3394 insn
= jump_chain
[INSN_UID (insn
)])
3395 if (jump_chain
[INSN_UID (insn
)] == jump
)
3397 jump_chain
[INSN_UID (insn
)] = jump_chain
[INSN_UID (jump
)];
3403 /* Make jump JUMP jump to label NLABEL, assuming it used to be a tablejump.
3405 If the old jump target label (before the dispatch table) becomes unused,
3406 it and the dispatch table may be deleted. In that case, find the insn
3407 before the jump references that label and delete it and logical successors
3411 redirect_tablejump (jump
, nlabel
)
3414 register rtx olabel
= JUMP_LABEL (jump
);
3416 /* Add this jump to the jump_chain of NLABEL. */
3417 if (jump_chain
&& INSN_UID (nlabel
) < max_jump_chain
3418 && INSN_UID (jump
) < max_jump_chain
)
3420 jump_chain
[INSN_UID (jump
)] = jump_chain
[INSN_UID (nlabel
)];
3421 jump_chain
[INSN_UID (nlabel
)] = jump
;
3424 PATTERN (jump
) = gen_jump (nlabel
);
3425 JUMP_LABEL (jump
) = nlabel
;
3426 ++LABEL_NUSES (nlabel
);
3427 INSN_CODE (jump
) = -1;
3429 if (--LABEL_NUSES (olabel
) == 0)
3431 delete_labelref_insn (jump
, olabel
, 0);
3432 delete_insn (olabel
);
3436 /* Find the insn referencing LABEL that is a logical predecessor of INSN.
3437 If we found one, delete it and then delete this insn if DELETE_THIS is
3438 non-zero. Return non-zero if INSN or a predecessor references LABEL. */
3441 delete_labelref_insn (insn
, label
, delete_this
)
3448 if (GET_CODE (insn
) != NOTE
3449 && reg_mentioned_p (label
, PATTERN (insn
)))
3460 for (link
= LOG_LINKS (insn
); link
; link
= XEXP (link
, 1))
3461 if (delete_labelref_insn (XEXP (link
, 0), label
, 1))
3475 /* Like rtx_equal_p except that it considers two REGs as equal
3476 if they renumber to the same value and considers two commutative
3477 operations to be the same if the order of the operands has been
3480 ??? Addition is not commutative on the PA due to the weird implicit
3481 space register selection rules for memory addresses. Therefore, we
3482 don't consider a + b == b + a.
3484 We could/should make this test a little tighter. Possibly only
3485 disabling it on the PA via some backend macro or only disabling this
3486 case when the PLUS is inside a MEM. */
3489 rtx_renumbered_equal_p (x
, y
)
3493 register RTX_CODE code
= GET_CODE (x
);
3494 register const char *fmt
;
3499 if ((code
== REG
|| (code
== SUBREG
&& GET_CODE (SUBREG_REG (x
)) == REG
))
3500 && (GET_CODE (y
) == REG
|| (GET_CODE (y
) == SUBREG
3501 && GET_CODE (SUBREG_REG (y
)) == REG
)))
3503 int reg_x
= -1, reg_y
= -1;
3504 int word_x
= 0, word_y
= 0;
3506 if (GET_MODE (x
) != GET_MODE (y
))
3509 /* If we haven't done any renumbering, don't
3510 make any assumptions. */
3511 if (reg_renumber
== 0)
3512 return rtx_equal_p (x
, y
);
3516 reg_x
= REGNO (SUBREG_REG (x
));
3517 word_x
= SUBREG_WORD (x
);
3519 if (reg_renumber
[reg_x
] >= 0)
3521 reg_x
= reg_renumber
[reg_x
] + word_x
;
3529 if (reg_renumber
[reg_x
] >= 0)
3530 reg_x
= reg_renumber
[reg_x
];
3533 if (GET_CODE (y
) == SUBREG
)
3535 reg_y
= REGNO (SUBREG_REG (y
));
3536 word_y
= SUBREG_WORD (y
);
3538 if (reg_renumber
[reg_y
] >= 0)
3540 reg_y
= reg_renumber
[reg_y
];
3548 if (reg_renumber
[reg_y
] >= 0)
3549 reg_y
= reg_renumber
[reg_y
];
3552 return reg_x
>= 0 && reg_x
== reg_y
&& word_x
== word_y
;
3555 /* Now we have disposed of all the cases
3556 in which different rtx codes can match. */
3557 if (code
!= GET_CODE (y
))
3569 return INTVAL (x
) == INTVAL (y
);
3572 /* We can't assume nonlocal labels have their following insns yet. */
3573 if (LABEL_REF_NONLOCAL_P (x
) || LABEL_REF_NONLOCAL_P (y
))
3574 return XEXP (x
, 0) == XEXP (y
, 0);
3576 /* Two label-refs are equivalent if they point at labels
3577 in the same position in the instruction stream. */
3578 return (next_real_insn (XEXP (x
, 0))
3579 == next_real_insn (XEXP (y
, 0)));
3582 return XSTR (x
, 0) == XSTR (y
, 0);
3585 /* If we didn't match EQ equality above, they aren't the same. */
3592 /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. */
3594 if (GET_MODE (x
) != GET_MODE (y
))
3597 /* For commutative operations, the RTX match if the operand match in any
3598 order. Also handle the simple binary and unary cases without a loop.
3600 ??? Don't consider PLUS a commutative operator; see comments above. */
3601 if ((code
== EQ
|| code
== NE
|| GET_RTX_CLASS (code
) == 'c')
3603 return ((rtx_renumbered_equal_p (XEXP (x
, 0), XEXP (y
, 0))
3604 && rtx_renumbered_equal_p (XEXP (x
, 1), XEXP (y
, 1)))
3605 || (rtx_renumbered_equal_p (XEXP (x
, 0), XEXP (y
, 1))
3606 && rtx_renumbered_equal_p (XEXP (x
, 1), XEXP (y
, 0))));
3607 else if (GET_RTX_CLASS (code
) == '<' || GET_RTX_CLASS (code
) == '2')
3608 return (rtx_renumbered_equal_p (XEXP (x
, 0), XEXP (y
, 0))
3609 && rtx_renumbered_equal_p (XEXP (x
, 1), XEXP (y
, 1)));
3610 else if (GET_RTX_CLASS (code
) == '1')
3611 return rtx_renumbered_equal_p (XEXP (x
, 0), XEXP (y
, 0));
3613 /* Compare the elements. If any pair of corresponding elements
3614 fail to match, return 0 for the whole things. */
3616 fmt
= GET_RTX_FORMAT (code
);
3617 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
3623 if (XWINT (x
, i
) != XWINT (y
, i
))
3628 if (XINT (x
, i
) != XINT (y
, i
))
3633 if (strcmp (XSTR (x
, i
), XSTR (y
, i
)))
3638 if (! rtx_renumbered_equal_p (XEXP (x
, i
), XEXP (y
, i
)))
3643 if (XEXP (x
, i
) != XEXP (y
, i
))
3650 if (XVECLEN (x
, i
) != XVECLEN (y
, i
))
3652 for (j
= XVECLEN (x
, i
) - 1; j
>= 0; j
--)
3653 if (!rtx_renumbered_equal_p (XVECEXP (x
, i
, j
), XVECEXP (y
, i
, j
)))
3664 /* If X is a hard register or equivalent to one or a subregister of one,
3665 return the hard register number. If X is a pseudo register that was not
3666 assigned a hard register, return the pseudo register number. Otherwise,
3667 return -1. Any rtx is valid for X. */
3673 if (GET_CODE (x
) == REG
)
3675 if (REGNO (x
) >= FIRST_PSEUDO_REGISTER
&& reg_renumber
[REGNO (x
)] >= 0)
3676 return reg_renumber
[REGNO (x
)];
3679 if (GET_CODE (x
) == SUBREG
)
3681 int base
= true_regnum (SUBREG_REG (x
));
3682 if (base
>= 0 && base
< FIRST_PSEUDO_REGISTER
)
3683 return SUBREG_WORD (x
) + base
;
3688 /* Optimize code of the form:
3690 for (x = a[i]; x; ...)
3692 for (x = a[i]; x; ...)
3696 Loop optimize will change the above code into
3700 { ...; if (! (x = ...)) break; }
3703 { ...; if (! (x = ...)) break; }
3706 In general, if the first test fails, the program can branch
3707 directly to `foo' and skip the second try which is doomed to fail.
3708 We run this after loop optimization and before flow analysis. */
3710 /* When comparing the insn patterns, we track the fact that different
3711 pseudo-register numbers may have been used in each computation.
3712 The following array stores an equivalence -- same_regs[I] == J means
3713 that pseudo register I was used in the first set of tests in a context
3714 where J was used in the second set. We also count the number of such
3715 pending equivalences. If nonzero, the expressions really aren't the
3718 static int *same_regs
;
3720 static int num_same_regs
;
3722 /* Track any registers modified between the target of the first jump and
3723 the second jump. They never compare equal. */
3725 static char *modified_regs
;
3727 /* Record if memory was modified. */
3729 static int modified_mem
;
3731 /* Called via note_stores on each insn between the target of the first
3732 branch and the second branch. It marks any changed registers. */
3735 mark_modified_reg (dest
, x
, data
)
3737 rtx x ATTRIBUTE_UNUSED
;
3738 void *data ATTRIBUTE_UNUSED
;
3743 if (GET_CODE (dest
) == SUBREG
)
3744 dest
= SUBREG_REG (dest
);
3746 if (GET_CODE (dest
) == MEM
)
3749 if (GET_CODE (dest
) != REG
)
3752 regno
= REGNO (dest
);
3753 if (regno
>= FIRST_PSEUDO_REGISTER
)
3754 modified_regs
[regno
] = 1;
3756 for (i
= 0; i
< HARD_REGNO_NREGS (regno
, GET_MODE (dest
)); i
++)
3757 modified_regs
[regno
+ i
] = 1;
3760 /* F is the first insn in the chain of insns. */
3763 thread_jumps (f
, max_reg
, flag_before_loop
)
3766 int flag_before_loop
;
3768 /* Basic algorithm is to find a conditional branch,
3769 the label it may branch to, and the branch after
3770 that label. If the two branches test the same condition,
3771 walk back from both branch paths until the insn patterns
3772 differ, or code labels are hit. If we make it back to
3773 the target of the first branch, then we know that the first branch
3774 will either always succeed or always fail depending on the relative
3775 senses of the two branches. So adjust the first branch accordingly
3778 rtx label
, b1
, b2
, t1
, t2
;
3779 enum rtx_code code1
, code2
;
3780 rtx b1op0
, b1op1
, b2op0
, b2op1
;
3785 /* Allocate register tables and quick-reset table. */
3786 modified_regs
= (char *) xmalloc (max_reg
* sizeof (char));
3787 same_regs
= (int *) xmalloc (max_reg
* sizeof (int));
3788 all_reset
= (int *) xmalloc (max_reg
* sizeof (int));
3789 for (i
= 0; i
< max_reg
; i
++)
3796 for (b1
= f
; b1
; b1
= NEXT_INSN (b1
))
3798 /* Get to a candidate branch insn. */
3799 if (GET_CODE (b1
) != JUMP_INSN
3800 || ! condjump_p (b1
) || simplejump_p (b1
)
3801 || JUMP_LABEL (b1
) == 0)
3804 bzero (modified_regs
, max_reg
* sizeof (char));
3807 bcopy ((char *) all_reset
, (char *) same_regs
,
3808 max_reg
* sizeof (int));
3811 label
= JUMP_LABEL (b1
);
3813 /* Look for a branch after the target. Record any registers and
3814 memory modified between the target and the branch. Stop when we
3815 get to a label since we can't know what was changed there. */
3816 for (b2
= NEXT_INSN (label
); b2
; b2
= NEXT_INSN (b2
))
3818 if (GET_CODE (b2
) == CODE_LABEL
)
3821 else if (GET_CODE (b2
) == JUMP_INSN
)
3823 /* If this is an unconditional jump and is the only use of
3824 its target label, we can follow it. */
3825 if (simplejump_p (b2
)
3826 && JUMP_LABEL (b2
) != 0
3827 && LABEL_NUSES (JUMP_LABEL (b2
)) == 1)
3829 b2
= JUMP_LABEL (b2
);
3836 if (GET_CODE (b2
) != CALL_INSN
&& GET_CODE (b2
) != INSN
)
3839 if (GET_CODE (b2
) == CALL_INSN
)
3842 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; i
++)
3843 if (call_used_regs
[i
] && ! fixed_regs
[i
]
3844 && i
!= STACK_POINTER_REGNUM
3845 && i
!= FRAME_POINTER_REGNUM
3846 && i
!= HARD_FRAME_POINTER_REGNUM
3847 && i
!= ARG_POINTER_REGNUM
)
3848 modified_regs
[i
] = 1;
3851 note_stores (PATTERN (b2
), mark_modified_reg
, NULL
);
3854 /* Check the next candidate branch insn from the label
3857 || GET_CODE (b2
) != JUMP_INSN
3859 || ! condjump_p (b2
)
3860 || simplejump_p (b2
))
3863 /* Get the comparison codes and operands, reversing the
3864 codes if appropriate. If we don't have comparison codes,
3865 we can't do anything. */
3866 b1op0
= XEXP (XEXP (SET_SRC (PATTERN (b1
)), 0), 0);
3867 b1op1
= XEXP (XEXP (SET_SRC (PATTERN (b1
)), 0), 1);
3868 code1
= GET_CODE (XEXP (SET_SRC (PATTERN (b1
)), 0));
3869 if (XEXP (SET_SRC (PATTERN (b1
)), 1) == pc_rtx
)
3870 code1
= reverse_condition (code1
);
3872 b2op0
= XEXP (XEXP (SET_SRC (PATTERN (b2
)), 0), 0);
3873 b2op1
= XEXP (XEXP (SET_SRC (PATTERN (b2
)), 0), 1);
3874 code2
= GET_CODE (XEXP (SET_SRC (PATTERN (b2
)), 0));
3875 if (XEXP (SET_SRC (PATTERN (b2
)), 1) == pc_rtx
)
3876 code2
= reverse_condition (code2
);
3878 /* If they test the same things and knowing that B1 branches
3879 tells us whether or not B2 branches, check if we
3880 can thread the branch. */
3881 if (rtx_equal_for_thread_p (b1op0
, b2op0
, b2
)
3882 && rtx_equal_for_thread_p (b1op1
, b2op1
, b2
)
3883 && (comparison_dominates_p (code1
, code2
)
3884 || (can_reverse_comparison_p (XEXP (SET_SRC (PATTERN (b1
)),
3887 && comparison_dominates_p (code1
, reverse_condition (code2
)))))
3890 t1
= prev_nonnote_insn (b1
);
3891 t2
= prev_nonnote_insn (b2
);
3893 while (t1
!= 0 && t2
!= 0)
3897 /* We have reached the target of the first branch.
3898 If there are no pending register equivalents,
3899 we know that this branch will either always
3900 succeed (if the senses of the two branches are
3901 the same) or always fail (if not). */
3904 if (num_same_regs
!= 0)
3907 if (comparison_dominates_p (code1
, code2
))
3908 new_label
= JUMP_LABEL (b2
);
3910 new_label
= get_label_after (b2
);
3912 if (JUMP_LABEL (b1
) != new_label
)
3914 rtx prev
= PREV_INSN (new_label
);
3916 if (flag_before_loop
3917 && GET_CODE (prev
) == NOTE
3918 && NOTE_LINE_NUMBER (prev
) == NOTE_INSN_LOOP_BEG
)
3920 /* Don't thread to the loop label. If a loop
3921 label is reused, loop optimization will
3922 be disabled for that loop. */
3923 new_label
= gen_label_rtx ();
3924 emit_label_after (new_label
, PREV_INSN (prev
));
3926 changed
|= redirect_jump (b1
, new_label
);
3931 /* If either of these is not a normal insn (it might be
3932 a JUMP_INSN, CALL_INSN, or CODE_LABEL) we fail. (NOTEs
3933 have already been skipped above.) Similarly, fail
3934 if the insns are different. */
3935 if (GET_CODE (t1
) != INSN
|| GET_CODE (t2
) != INSN
3936 || recog_memoized (t1
) != recog_memoized (t2
)
3937 || ! rtx_equal_for_thread_p (PATTERN (t1
),
3941 t1
= prev_nonnote_insn (t1
);
3942 t2
= prev_nonnote_insn (t2
);
3949 free (modified_regs
);
3954 /* This is like RTX_EQUAL_P except that it knows about our handling of
3955 possibly equivalent registers and knows to consider volatile and
3956 modified objects as not equal.
3958 YINSN is the insn containing Y. */
3961 rtx_equal_for_thread_p (x
, y
, yinsn
)
3967 register enum rtx_code code
;
3968 register const char *fmt
;
3970 code
= GET_CODE (x
);
3971 /* Rtx's of different codes cannot be equal. */
3972 if (code
!= GET_CODE (y
))
3975 /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent.
3976 (REG:SI x) and (REG:HI x) are NOT equivalent. */
3978 if (GET_MODE (x
) != GET_MODE (y
))
3981 /* For floating-point, consider everything unequal. This is a bit
3982 pessimistic, but this pass would only rarely do anything for FP
3984 if (TARGET_FLOAT_FORMAT
== IEEE_FLOAT_FORMAT
3985 && FLOAT_MODE_P (GET_MODE (x
)) && ! flag_fast_math
)
3988 /* For commutative operations, the RTX match if the operand match in any
3989 order. Also handle the simple binary and unary cases without a loop. */
3990 if (code
== EQ
|| code
== NE
|| GET_RTX_CLASS (code
) == 'c')
3991 return ((rtx_equal_for_thread_p (XEXP (x
, 0), XEXP (y
, 0), yinsn
)
3992 && rtx_equal_for_thread_p (XEXP (x
, 1), XEXP (y
, 1), yinsn
))
3993 || (rtx_equal_for_thread_p (XEXP (x
, 0), XEXP (y
, 1), yinsn
)
3994 && rtx_equal_for_thread_p (XEXP (x
, 1), XEXP (y
, 0), yinsn
)));
3995 else if (GET_RTX_CLASS (code
) == '<' || GET_RTX_CLASS (code
) == '2')
3996 return (rtx_equal_for_thread_p (XEXP (x
, 0), XEXP (y
, 0), yinsn
)
3997 && rtx_equal_for_thread_p (XEXP (x
, 1), XEXP (y
, 1), yinsn
));
3998 else if (GET_RTX_CLASS (code
) == '1')
3999 return rtx_equal_for_thread_p (XEXP (x
, 0), XEXP (y
, 0), yinsn
);
4001 /* Handle special-cases first. */
4005 if (REGNO (x
) == REGNO (y
) && ! modified_regs
[REGNO (x
)])
4008 /* If neither is user variable or hard register, check for possible
4010 if (REG_USERVAR_P (x
) || REG_USERVAR_P (y
)
4011 || REGNO (x
) < FIRST_PSEUDO_REGISTER
4012 || REGNO (y
) < FIRST_PSEUDO_REGISTER
)
4015 if (same_regs
[REGNO (x
)] == -1)
4017 same_regs
[REGNO (x
)] = REGNO (y
);
4020 /* If this is the first time we are seeing a register on the `Y'
4021 side, see if it is the last use. If not, we can't thread the
4022 jump, so mark it as not equivalent. */
4023 if (REGNO_LAST_UID (REGNO (y
)) != INSN_UID (yinsn
))
4029 return (same_regs
[REGNO (x
)] == (int) REGNO (y
));
4034 /* If memory modified or either volatile, not equivalent.
4035 Else, check address. */
4036 if (modified_mem
|| MEM_VOLATILE_P (x
) || MEM_VOLATILE_P (y
))
4039 return rtx_equal_for_thread_p (XEXP (x
, 0), XEXP (y
, 0), yinsn
);
4042 if (MEM_VOLATILE_P (x
) || MEM_VOLATILE_P (y
))
4048 /* Cancel a pending `same_regs' if setting equivalenced registers.
4049 Then process source. */
4050 if (GET_CODE (SET_DEST (x
)) == REG
4051 && GET_CODE (SET_DEST (y
)) == REG
)
4053 if (same_regs
[REGNO (SET_DEST (x
))] == (int) REGNO (SET_DEST (y
)))
4055 same_regs
[REGNO (SET_DEST (x
))] = -1;
4058 else if (REGNO (SET_DEST (x
)) != REGNO (SET_DEST (y
)))
4062 if (rtx_equal_for_thread_p (SET_DEST (x
), SET_DEST (y
), yinsn
) == 0)
4065 return rtx_equal_for_thread_p (SET_SRC (x
), SET_SRC (y
), yinsn
);
4068 return XEXP (x
, 0) == XEXP (y
, 0);
4071 return XSTR (x
, 0) == XSTR (y
, 0);
4080 fmt
= GET_RTX_FORMAT (code
);
4081 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
4086 if (XWINT (x
, i
) != XWINT (y
, i
))
4092 if (XINT (x
, i
) != XINT (y
, i
))
4098 /* Two vectors must have the same length. */
4099 if (XVECLEN (x
, i
) != XVECLEN (y
, i
))
4102 /* And the corresponding elements must match. */
4103 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
4104 if (rtx_equal_for_thread_p (XVECEXP (x
, i
, j
),
4105 XVECEXP (y
, i
, j
), yinsn
) == 0)
4110 if (rtx_equal_for_thread_p (XEXP (x
, i
), XEXP (y
, i
), yinsn
) == 0)
4116 if (strcmp (XSTR (x
, i
), XSTR (y
, i
)))
4121 /* These are just backpointers, so they don't matter. */
4128 /* It is believed that rtx's at this level will never
4129 contain anything but integers and other rtx's,
4130 except for within LABEL_REFs and SYMBOL_REFs. */