1 /* Data flow analysis for GNU compiler.
2 Copyright (C) 1987, 88, 92-96, 1997 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
22 /* This file contains the data flow analysis pass of the compiler.
23 It computes data flow information
24 which tells combine_instructions which insns to consider combining
25 and controls register allocation.
27 Additional data flow information that is too bulky to record
28 is generated during the analysis, and is used at that time to
29 create autoincrement and autodecrement addressing.
31 The first step is dividing the function into basic blocks.
32 find_basic_blocks does this. Then life_analysis determines
33 where each register is live and where it is dead.
35 ** find_basic_blocks **
37 find_basic_blocks divides the current function's rtl
38 into basic blocks. It records the beginnings and ends of the
39 basic blocks in the vectors basic_block_head and basic_block_end,
40 and the number of blocks in n_basic_blocks.
42 find_basic_blocks also finds any unreachable loops
47 life_analysis is called immediately after find_basic_blocks.
48 It uses the basic block information to determine where each
49 hard or pseudo register is live.
51 ** live-register info **
53 The information about where each register is live is in two parts:
54 the REG_NOTES of insns, and the vector basic_block_live_at_start.
56 basic_block_live_at_start has an element for each basic block,
57 and the element is a bit-vector with a bit for each hard or pseudo
58 register. The bit is 1 if the register is live at the beginning
61 Two types of elements can be added to an insn's REG_NOTES.
62 A REG_DEAD note is added to an insn's REG_NOTES for any register
63 that meets both of two conditions: The value in the register is not
64 needed in subsequent insns and the insn does not replace the value in
65 the register (in the case of multi-word hard registers, the value in
66 each register must be replaced by the insn to avoid a REG_DEAD note).
68 In the vast majority of cases, an object in a REG_DEAD note will be
69 used somewhere in the insn. The (rare) exception to this is if an
70 insn uses a multi-word hard register and only some of the registers are
71 needed in subsequent insns. In that case, REG_DEAD notes will be
72 provided for those hard registers that are not subsequently needed.
73 Partial REG_DEAD notes of this type do not occur when an insn sets
74 only some of the hard registers used in such a multi-word operand;
75 omitting REG_DEAD notes for objects stored in an insn is optional and
76 the desire to do so does not justify the complexity of the partial
79 REG_UNUSED notes are added for each register that is set by the insn
80 but is unused subsequently (if every register set by the insn is unused
81 and the insn does not reference memory or have some other side-effect,
82 the insn is deleted instead). If only part of a multi-word hard
83 register is used in a subsequent insn, REG_UNUSED notes are made for
84 the parts that will not be used.
86 To determine which registers are live after any insn, one can
87 start from the beginning of the basic block and scan insns, noting
88 which registers are set by each insn and which die there.
90 ** Other actions of life_analysis **
92 life_analysis sets up the LOG_LINKS fields of insns because the
93 information needed to do so is readily available.
95 life_analysis deletes insns whose only effect is to store a value
98 life_analysis notices cases where a reference to a register as
99 a memory address can be combined with a preceding or following
100 incrementation or decrementation of the register. The separate
101 instruction to increment or decrement is deleted and the address
102 is changed to a POST_INC or similar rtx.
104 Each time an incrementing or decrementing address is created,
105 a REG_INC element is added to the insn's REG_NOTES list.
107 life_analysis fills in certain vectors containing information about
108 register usage: reg_n_refs, reg_n_deaths, reg_n_sets, reg_live_length,
109 reg_n_calls_crosses and reg_basic_block. */
114 #include "basic-block.h"
115 #include "insn-config.h"
117 #include "hard-reg-set.h"
123 #define obstack_chunk_alloc xmalloc
124 #define obstack_chunk_free free
126 /* The contents of the current function definition are allocated
127 in this obstack, and all are freed at the end of the function.
128 For top-level functions, this is temporary_obstack.
129 Separate obstacks are made for nested functions. */
131 extern struct obstack
*function_obstack
;
133 /* List of labels that must never be deleted. */
134 extern rtx forced_labels
;
136 /* Get the basic block number of an insn.
137 This info should not be expected to remain available
138 after the end of life_analysis. */
140 /* This is the limit of the allocated space in the following two arrays. */
142 static int max_uid_for_flow
;
144 #define BLOCK_NUM(INSN) uid_block_number[INSN_UID (INSN)]
146 /* This is where the BLOCK_NUM values are really stored.
147 This is set up by find_basic_blocks and used there and in life_analysis,
150 static int *uid_block_number
;
152 /* INSN_VOLATILE (insn) is 1 if the insn refers to anything volatile. */
154 #define INSN_VOLATILE(INSN) uid_volatile[INSN_UID (INSN)]
155 static char *uid_volatile
;
157 /* Number of basic blocks in the current function. */
161 /* Maximum register number used in this function, plus one. */
165 /* Maximum number of SCRATCH rtx's used in any basic block of this
170 /* Number of SCRATCH rtx's in the current block. */
172 static int num_scratch
;
174 /* Indexed by n, giving various register information */
176 reg_info
*reg_n_info
;
178 /* Element N is the next insn that uses (hard or pseudo) register number N
179 within the current basic block; or zero, if there is no such insn.
180 This is valid only during the final backward scan in propagate_block. */
182 static rtx
*reg_next_use
;
184 /* Size of a regset for the current function,
185 in (1) bytes and (2) elements. */
190 /* Element N is first insn in basic block N.
191 This info lasts until we finish compiling the function. */
193 rtx
*basic_block_head
;
195 /* Element N is last insn in basic block N.
196 This info lasts until we finish compiling the function. */
198 rtx
*basic_block_end
;
200 /* Element N is a regset describing the registers live
201 at the start of basic block N.
202 This info lasts until we finish compiling the function. */
204 regset
*basic_block_live_at_start
;
206 /* Regset of regs live when calls to `setjmp'-like functions happen. */
208 regset regs_live_at_setjmp
;
210 /* List made of EXPR_LIST rtx's which gives pairs of pseudo registers
211 that have to go in the same hard reg.
212 The first two regs in the list are a pair, and the next two
213 are another pair, etc. */
216 /* Element N is nonzero if control can drop into basic block N
217 from the preceding basic block. Freed after life_analysis. */
219 static char *basic_block_drops_in
;
221 /* Element N is depth within loops of the last insn in basic block number N.
222 Freed after life_analysis. */
224 static short *basic_block_loop_depth
;
226 /* Element N nonzero if basic block N can actually be reached.
227 Vector exists only during find_basic_blocks. */
229 static char *block_live_static
;
231 /* Depth within loops of basic block being scanned for lifetime analysis,
232 plus one. This is the weight attached to references to registers. */
234 static int loop_depth
;
236 /* During propagate_block, this is non-zero if the value of CC0 is live. */
240 /* During propagate_block, this contains the last MEM stored into. It
241 is used to eliminate consecutive stores to the same location. */
243 static rtx last_mem_set
;
245 /* Set of registers that may be eliminable. These are handled specially
246 in updating regs_ever_live. */
248 static HARD_REG_SET elim_reg_set
;
250 /* Forward declarations */
251 static void find_basic_blocks
PROTO((rtx
, rtx
));
252 static void mark_label_ref
PROTO((rtx
, rtx
, int));
253 static void life_analysis
PROTO((rtx
, int));
254 void allocate_for_life_analysis
PROTO((void));
255 void init_regset_vector
PROTO((regset
*, int, struct obstack
*));
256 void free_regset_vector
PROTO((regset
*, int));
257 static void propagate_block
PROTO((regset
, rtx
, rtx
, int,
259 static rtx flow_delete_insn
PROTO((rtx
));
260 static int insn_dead_p
PROTO((rtx
, regset
, int));
261 static int libcall_dead_p
PROTO((rtx
, regset
, rtx
, rtx
));
262 static void mark_set_regs
PROTO((regset
, regset
, rtx
,
264 static void mark_set_1
PROTO((regset
, regset
, rtx
,
266 static void find_auto_inc
PROTO((regset
, rtx
, rtx
));
267 static void mark_used_regs
PROTO((regset
, regset
, rtx
, int, rtx
));
268 static int try_pre_increment_1
PROTO((rtx
));
269 static int try_pre_increment
PROTO((rtx
, rtx
, HOST_WIDE_INT
));
270 static rtx find_use_as_address
PROTO((rtx
, rtx
, HOST_WIDE_INT
));
271 void dump_flow_info
PROTO((FILE *));
273 /* Find basic blocks of the current function and perform data flow analysis.
274 F is the first insn of the function and NREGS the number of register numbers
278 flow_analysis (f
, nregs
, file
)
285 rtx nonlocal_label_list
= nonlocal_label_rtx_list ();
287 #ifdef ELIMINABLE_REGS
288 static struct {int from
, to
; } eliminables
[] = ELIMINABLE_REGS
;
291 /* Record which registers will be eliminated. We use this in
294 CLEAR_HARD_REG_SET (elim_reg_set
);
296 #ifdef ELIMINABLE_REGS
297 for (i
= 0; i
< sizeof eliminables
/ sizeof eliminables
[0]; i
++)
298 SET_HARD_REG_BIT (elim_reg_set
, eliminables
[i
].from
);
300 SET_HARD_REG_BIT (elim_reg_set
, FRAME_POINTER_REGNUM
);
303 /* Count the basic blocks. Also find maximum insn uid value used. */
306 register RTX_CODE prev_code
= JUMP_INSN
;
307 register RTX_CODE code
;
309 max_uid_for_flow
= 0;
311 for (insn
= f
, i
= 0; insn
; insn
= NEXT_INSN (insn
))
313 code
= GET_CODE (insn
);
314 if (INSN_UID (insn
) > max_uid_for_flow
)
315 max_uid_for_flow
= INSN_UID (insn
);
316 if (code
== CODE_LABEL
317 || (GET_RTX_CLASS (code
) == 'i'
318 && (prev_code
== JUMP_INSN
319 || (prev_code
== CALL_INSN
320 && nonlocal_label_list
!= 0)
321 || prev_code
== BARRIER
)))
324 if (code
== CALL_INSN
&& find_reg_note (insn
, REG_RETVAL
, NULL_RTX
))
333 /* Leave space for insns we make in some cases for auto-inc. These cases
334 are rare, so we don't need too much space. */
335 max_uid_for_flow
+= max_uid_for_flow
/ 10;
338 /* Allocate some tables that last till end of compiling this function
339 and some needed only in find_basic_blocks and life_analysis. */
342 basic_block_head
= (rtx
*) oballoc (n_basic_blocks
* sizeof (rtx
));
343 basic_block_end
= (rtx
*) oballoc (n_basic_blocks
* sizeof (rtx
));
344 basic_block_drops_in
= (char *) alloca (n_basic_blocks
);
345 basic_block_loop_depth
= (short *) alloca (n_basic_blocks
* sizeof (short));
347 = (int *) alloca ((max_uid_for_flow
+ 1) * sizeof (int));
348 uid_volatile
= (char *) alloca (max_uid_for_flow
+ 1);
349 bzero (uid_volatile
, max_uid_for_flow
+ 1);
351 find_basic_blocks (f
, nonlocal_label_list
);
352 life_analysis (f
, nregs
);
354 dump_flow_info (file
);
356 basic_block_drops_in
= 0;
357 uid_block_number
= 0;
358 basic_block_loop_depth
= 0;
361 /* Find all basic blocks of the function whose first insn is F.
362 Store the correct data in the tables that describe the basic blocks,
363 set up the chains of references for each CODE_LABEL, and
364 delete any entire basic blocks that cannot be reached.
366 NONLOCAL_LABEL_LIST is the same local variable from flow_analysis. */
369 find_basic_blocks (f
, nonlocal_label_list
)
370 rtx f
, nonlocal_label_list
;
374 register char *block_live
= (char *) alloca (n_basic_blocks
);
375 register char *block_marked
= (char *) alloca (n_basic_blocks
);
376 /* List of label_refs to all labels whose addresses are taken
378 rtx label_value_list
;
379 int label_value_list_marked_live
;
381 enum rtx_code prev_code
, code
;
387 label_value_list
= 0;
388 label_value_list_marked_live
= 0;
389 block_live_static
= block_live
;
390 bzero (block_live
, n_basic_blocks
);
391 bzero (block_marked
, n_basic_blocks
);
393 /* Initialize with just block 0 reachable and no blocks marked. */
394 if (n_basic_blocks
> 0)
397 /* Initialize the ref chain of each label to 0. Record where all the
398 blocks start and end and their depth in loops. For each insn, record
399 the block it is in. Also mark as reachable any blocks headed by labels
400 that must not be deleted. */
402 for (insn
= f
, i
= -1, prev_code
= JUMP_INSN
, depth
= 1;
403 insn
; insn
= NEXT_INSN (insn
))
405 code
= GET_CODE (insn
);
408 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_LOOP_BEG
)
410 else if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_LOOP_END
)
414 /* A basic block starts at label, or after something that can jump. */
415 else if (code
== CODE_LABEL
416 || (GET_RTX_CLASS (code
) == 'i'
417 && (prev_code
== JUMP_INSN
418 || (prev_code
== CALL_INSN
419 && nonlocal_label_list
!= 0
420 && ! find_reg_note (insn
, REG_RETVAL
, NULL_RTX
))
421 || prev_code
== BARRIER
)))
423 basic_block_head
[++i
] = insn
;
424 basic_block_end
[i
] = insn
;
425 basic_block_loop_depth
[i
] = depth
;
427 if (code
== CODE_LABEL
)
429 LABEL_REFS (insn
) = insn
;
430 /* Any label that cannot be deleted
431 is considered to start a reachable block. */
432 if (LABEL_PRESERVE_P (insn
))
437 else if (GET_RTX_CLASS (code
) == 'i')
439 basic_block_end
[i
] = insn
;
440 basic_block_loop_depth
[i
] = depth
;
443 if (GET_RTX_CLASS (code
) == 'i')
445 /* Make a list of all labels referred to other than by jumps. */
446 for (note
= REG_NOTES (insn
); note
; note
= XEXP (note
, 1))
447 if (REG_NOTE_KIND (note
) == REG_LABEL
)
448 label_value_list
= gen_rtx (EXPR_LIST
, VOIDmode
, XEXP (note
, 0),
452 BLOCK_NUM (insn
) = i
;
458 /* During the second pass, `n_basic_blocks' is only an upper bound.
459 Only perform the sanity check for the first pass, and on the second
460 pass ensure `n_basic_blocks' is set to the correct value. */
461 if (pass
== 1 && i
+ 1 != n_basic_blocks
)
463 n_basic_blocks
= i
+ 1;
465 for (x
= forced_labels
; x
; x
= XEXP (x
, 1))
466 if (! LABEL_REF_NONLOCAL_P (x
))
467 block_live
[BLOCK_NUM (XEXP (x
, 0))] = 1;
469 for (x
= exception_handler_labels
; x
; x
= XEXP (x
, 1))
470 block_live
[BLOCK_NUM (XEXP (x
, 0))] = 1;
472 /* Record which basic blocks control can drop in to. */
474 for (i
= 0; i
< n_basic_blocks
; i
++)
476 for (insn
= PREV_INSN (basic_block_head
[i
]);
477 insn
&& GET_CODE (insn
) == NOTE
; insn
= PREV_INSN (insn
))
480 basic_block_drops_in
[i
] = insn
&& GET_CODE (insn
) != BARRIER
;
483 /* Now find which basic blocks can actually be reached
484 and put all jump insns' LABEL_REFS onto the ref-chains
485 of their target labels. */
487 if (n_basic_blocks
> 0)
489 int something_marked
= 1;
492 /* Find all indirect jump insns and mark them as possibly jumping to all
493 the labels whose addresses are explicitly used. This is because,
494 when there are computed gotos, we can't tell which labels they jump
495 to, of all the possibilities. */
497 for (insn
= f
; insn
; insn
= NEXT_INSN (insn
))
498 if (computed_jump_p (insn
))
500 if (label_value_list_marked_live
== 0)
502 label_value_list_marked_live
= 1;
504 /* This could be made smarter by only considering
505 these live, if the computed goto is live. */
507 /* Don't delete the labels (in this function) that
508 are referenced by non-jump instructions. */
510 for (x
= label_value_list
; x
; x
= XEXP (x
, 1))
511 if (! LABEL_REF_NONLOCAL_P (x
))
512 block_live
[BLOCK_NUM (XEXP (x
, 0))] = 1;
515 for (x
= label_value_list
; x
; x
= XEXP (x
, 1))
516 mark_label_ref (gen_rtx (LABEL_REF
, VOIDmode
, XEXP (x
, 0)),
519 for (x
= forced_labels
; x
; x
= XEXP (x
, 1))
520 mark_label_ref (gen_rtx (LABEL_REF
, VOIDmode
, XEXP (x
, 0)),
524 /* Find all call insns and mark them as possibly jumping
525 to all the nonlocal goto handler labels. */
527 for (insn
= f
; insn
; insn
= NEXT_INSN (insn
))
528 if (GET_CODE (insn
) == CALL_INSN
529 && ! find_reg_note (insn
, REG_RETVAL
, NULL_RTX
))
531 for (x
= nonlocal_label_list
; x
; x
= XEXP (x
, 1))
532 mark_label_ref (gen_rtx (LABEL_REF
, VOIDmode
, XEXP (x
, 0)),
535 /* ??? This could be made smarter:
536 in some cases it's possible to tell that certain
537 calls will not do a nonlocal goto.
539 For example, if the nested functions that do the
540 nonlocal gotos do not have their addresses taken, then
541 only calls to those functions or to other nested
542 functions that use them could possibly do nonlocal
546 /* All blocks associated with labels in label_value_list are
547 trivially considered as marked live, if the list is empty.
548 We do this to speed up the below code. */
550 if (label_value_list
== 0)
551 label_value_list_marked_live
= 1;
553 /* Pass over all blocks, marking each block that is reachable
554 and has not yet been marked.
555 Keep doing this until, in one pass, no blocks have been marked.
556 Then blocks_live and blocks_marked are identical and correct.
557 In addition, all jumps actually reachable have been marked. */
559 while (something_marked
)
561 something_marked
= 0;
562 for (i
= 0; i
< n_basic_blocks
; i
++)
563 if (block_live
[i
] && !block_marked
[i
])
566 something_marked
= 1;
567 if (i
+ 1 < n_basic_blocks
&& basic_block_drops_in
[i
+ 1])
568 block_live
[i
+ 1] = 1;
569 insn
= basic_block_end
[i
];
570 if (GET_CODE (insn
) == JUMP_INSN
)
571 mark_label_ref (PATTERN (insn
), insn
, 0);
573 if (label_value_list_marked_live
== 0)
574 /* Now that we know that this block is live, mark as
575 live, all the blocks that we might be able to get
578 for (insn
= basic_block_head
[i
];
579 insn
!= NEXT_INSN (basic_block_end
[i
]);
580 insn
= NEXT_INSN (insn
))
582 if (GET_RTX_CLASS (GET_CODE (insn
)) == 'i')
584 for (note
= REG_NOTES (insn
);
586 note
= XEXP (note
, 1))
587 if (REG_NOTE_KIND (note
) == REG_LABEL
)
590 block_live
[BLOCK_NUM (x
)] = 1;
597 /* ??? See if we have a "live" basic block that is not reachable.
598 This can happen if it is headed by a label that is preserved or
599 in one of the label lists, but no call or computed jump is in
600 the loop. It's not clear if we can delete the block or not,
601 but don't for now. However, we will mess up register status if
602 it remains unreachable, so add a fake reachability from the
605 for (i
= 1; i
< n_basic_blocks
; i
++)
606 if (block_live
[i
] && ! basic_block_drops_in
[i
]
607 && GET_CODE (basic_block_head
[i
]) == CODE_LABEL
608 && LABEL_REFS (basic_block_head
[i
]) == basic_block_head
[i
])
609 basic_block_drops_in
[i
] = 1;
611 /* Now delete the code for any basic blocks that can't be reached.
612 They can occur because jump_optimize does not recognize
613 unreachable loops as unreachable. */
616 for (i
= 0; i
< n_basic_blocks
; i
++)
621 /* Delete the insns in a (non-live) block. We physically delete
622 every non-note insn except the start and end (so
623 basic_block_head/end needn't be updated), we turn the latter
624 into NOTE_INSN_DELETED notes.
625 We use to "delete" the insns by turning them into notes, but
626 we may be deleting lots of insns that subsequent passes would
627 otherwise have to process. Secondly, lots of deleted blocks in
628 a row can really slow down propagate_block since it will
629 otherwise process insn-turned-notes multiple times when it
630 looks for loop begin/end notes. */
631 if (basic_block_head
[i
] != basic_block_end
[i
])
633 /* It would be quicker to delete all of these with a single
634 unchaining, rather than one at a time, but we need to keep
636 insn
= NEXT_INSN (basic_block_head
[i
]);
637 while (insn
!= basic_block_end
[i
])
639 if (GET_CODE (insn
) == BARRIER
)
641 else if (GET_CODE (insn
) != NOTE
)
642 insn
= flow_delete_insn (insn
);
644 insn
= NEXT_INSN (insn
);
647 insn
= basic_block_head
[i
];
648 if (GET_CODE (insn
) != NOTE
)
650 /* Turn the head into a deleted insn note. */
651 if (GET_CODE (insn
) == BARRIER
)
653 PUT_CODE (insn
, NOTE
);
654 NOTE_LINE_NUMBER (insn
) = NOTE_INSN_DELETED
;
655 NOTE_SOURCE_FILE (insn
) = 0;
657 insn
= basic_block_end
[i
];
658 if (GET_CODE (insn
) != NOTE
)
660 /* Turn the tail into a deleted insn note. */
661 if (GET_CODE (insn
) == BARRIER
)
663 PUT_CODE (insn
, NOTE
);
664 NOTE_LINE_NUMBER (insn
) = NOTE_INSN_DELETED
;
665 NOTE_SOURCE_FILE (insn
) = 0;
667 /* BARRIERs are between basic blocks, not part of one.
668 Delete a BARRIER if the preceding jump is deleted.
669 We cannot alter a BARRIER into a NOTE
670 because it is too short; but we can really delete
671 it because it is not part of a basic block. */
672 if (NEXT_INSN (insn
) != 0
673 && GET_CODE (NEXT_INSN (insn
)) == BARRIER
)
674 delete_insn (NEXT_INSN (insn
));
676 /* Each time we delete some basic blocks,
677 see if there is a jump around them that is
678 being turned into a no-op. If so, delete it. */
680 if (block_live
[i
- 1])
683 for (j
= i
+ 1; j
< n_basic_blocks
; j
++)
687 insn
= basic_block_end
[i
- 1];
688 if (GET_CODE (insn
) == JUMP_INSN
689 /* An unconditional jump is the only possibility
690 we must check for, since a conditional one
691 would make these blocks live. */
692 && simplejump_p (insn
)
693 && (label
= XEXP (SET_SRC (PATTERN (insn
)), 0), 1)
694 && INSN_UID (label
) != 0
695 && BLOCK_NUM (label
) == j
)
697 PUT_CODE (insn
, NOTE
);
698 NOTE_LINE_NUMBER (insn
) = NOTE_INSN_DELETED
;
699 NOTE_SOURCE_FILE (insn
) = 0;
700 if (GET_CODE (NEXT_INSN (insn
)) != BARRIER
)
702 delete_insn (NEXT_INSN (insn
));
709 /* There are pathological cases where one function calling hundreds of
710 nested inline functions can generate lots and lots of unreachable
711 blocks that jump can't delete. Since we don't use sparse matrices
712 a lot of memory will be needed to compile such functions.
713 Implementing sparse matrices is a fair bit of work and it is not
714 clear that they win more than they lose (we don't want to
715 unnecessarily slow down compilation of normal code). By making
716 another pass for the pathological case, we can greatly speed up
717 their compilation without hurting normal code. This works because
718 all the insns in the unreachable blocks have either been deleted or
720 Note that we're talking about reducing memory usage by 10's of
721 megabytes and reducing compilation time by several minutes. */
722 /* ??? The choice of when to make another pass is a bit arbitrary,
723 and was derived from empirical data. */
728 n_basic_blocks
-= deleted
;
729 /* `n_basic_blocks' may not be correct at this point: two previously
730 separate blocks may now be merged. That's ok though as we
731 recalculate it during the second pass. It certainly can't be
732 any larger than the current value. */
738 /* Subroutines of find_basic_blocks. */
740 /* Check expression X for label references;
741 if one is found, add INSN to the label's chain of references.
743 CHECKDUP means check for and avoid creating duplicate references
744 from the same insn. Such duplicates do no serious harm but
745 can slow life analysis. CHECKDUP is set only when duplicates
749 mark_label_ref (x
, insn
, checkdup
)
753 register RTX_CODE code
;
757 /* We can be called with NULL when scanning label_value_list. */
762 if (code
== LABEL_REF
)
764 register rtx label
= XEXP (x
, 0);
766 if (GET_CODE (label
) != CODE_LABEL
)
768 /* If the label was never emitted, this insn is junk,
769 but avoid a crash trying to refer to BLOCK_NUM (label).
770 This can happen as a result of a syntax error
771 and a diagnostic has already been printed. */
772 if (INSN_UID (label
) == 0)
774 CONTAINING_INSN (x
) = insn
;
775 /* if CHECKDUP is set, check for duplicate ref from same insn
778 for (y
= LABEL_REFS (label
); y
!= label
; y
= LABEL_NEXTREF (y
))
779 if (CONTAINING_INSN (y
) == insn
)
781 LABEL_NEXTREF (x
) = LABEL_REFS (label
);
782 LABEL_REFS (label
) = x
;
783 block_live_static
[BLOCK_NUM (label
)] = 1;
787 fmt
= GET_RTX_FORMAT (code
);
788 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
791 mark_label_ref (XEXP (x
, i
), insn
, 0);
795 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
796 mark_label_ref (XVECEXP (x
, i
, j
), insn
, 1);
801 /* Delete INSN by patching it out.
802 Return the next insn. */
805 flow_delete_insn (insn
)
808 /* ??? For the moment we assume we don't have to watch for NULLs here
809 since the start/end of basic blocks aren't deleted like this. */
810 NEXT_INSN (PREV_INSN (insn
)) = NEXT_INSN (insn
);
811 PREV_INSN (NEXT_INSN (insn
)) = PREV_INSN (insn
);
812 return NEXT_INSN (insn
);
815 /* Determine which registers are live at the start of each
816 basic block of the function whose first insn is F.
817 NREGS is the number of registers used in F.
818 We allocate the vector basic_block_live_at_start
819 and the regsets that it points to, and fill them with the data.
820 regset_size and regset_bytes are also set here. */
823 life_analysis (f
, nregs
)
829 /* For each basic block, a bitmask of regs
830 live on exit from the block. */
831 regset
*basic_block_live_at_end
;
832 /* For each basic block, a bitmask of regs
833 live on entry to a successor-block of this block.
834 If this does not match basic_block_live_at_end,
835 that must be updated, and the block must be rescanned. */
836 regset
*basic_block_new_live_at_end
;
837 /* For each basic block, a bitmask of regs
838 whose liveness at the end of the basic block
839 can make a difference in which regs are live on entry to the block.
840 These are the regs that are set within the basic block,
841 possibly excluding those that are used after they are set. */
842 regset
*basic_block_significant
;
846 struct obstack flow_obstack
;
848 gcc_obstack_init (&flow_obstack
);
852 bzero (regs_ever_live
, sizeof regs_ever_live
);
854 /* Allocate and zero out many data structures
855 that will record the data from lifetime analysis. */
857 allocate_for_life_analysis ();
859 reg_next_use
= (rtx
*) alloca (nregs
* sizeof (rtx
));
860 bzero ((char *) reg_next_use
, nregs
* sizeof (rtx
));
862 /* Set up several regset-vectors used internally within this function.
863 Their meanings are documented above, with their declarations. */
865 basic_block_live_at_end
866 = (regset
*) alloca (n_basic_blocks
* sizeof (regset
));
868 /* Don't use alloca since that leads to a crash rather than an error message
869 if there isn't enough space.
870 Don't use oballoc since we may need to allocate other things during
871 this function on the temporary obstack. */
872 init_regset_vector (basic_block_live_at_end
, n_basic_blocks
, &flow_obstack
);
874 basic_block_new_live_at_end
875 = (regset
*) alloca (n_basic_blocks
* sizeof (regset
));
876 init_regset_vector (basic_block_new_live_at_end
, n_basic_blocks
,
879 basic_block_significant
880 = (regset
*) alloca (n_basic_blocks
* sizeof (regset
));
881 init_regset_vector (basic_block_significant
, n_basic_blocks
, &flow_obstack
);
883 /* Record which insns refer to any volatile memory
884 or for any reason can't be deleted just because they are dead stores.
885 Also, delete any insns that copy a register to itself. */
887 for (insn
= f
; insn
; insn
= NEXT_INSN (insn
))
889 enum rtx_code code1
= GET_CODE (insn
);
890 if (code1
== CALL_INSN
)
891 INSN_VOLATILE (insn
) = 1;
892 else if (code1
== INSN
|| code1
== JUMP_INSN
)
894 /* Delete (in effect) any obvious no-op moves. */
895 if (GET_CODE (PATTERN (insn
)) == SET
896 && GET_CODE (SET_DEST (PATTERN (insn
))) == REG
897 && GET_CODE (SET_SRC (PATTERN (insn
))) == REG
898 && (REGNO (SET_DEST (PATTERN (insn
)))
899 == REGNO (SET_SRC (PATTERN (insn
))))
900 /* Insns carrying these notes are useful later on. */
901 && ! find_reg_note (insn
, REG_EQUAL
, NULL_RTX
))
903 PUT_CODE (insn
, NOTE
);
904 NOTE_LINE_NUMBER (insn
) = NOTE_INSN_DELETED
;
905 NOTE_SOURCE_FILE (insn
) = 0;
907 /* Delete (in effect) any obvious no-op moves. */
908 else if (GET_CODE (PATTERN (insn
)) == SET
909 && GET_CODE (SET_DEST (PATTERN (insn
))) == SUBREG
910 && GET_CODE (SUBREG_REG (SET_DEST (PATTERN (insn
)))) == REG
911 && GET_CODE (SET_SRC (PATTERN (insn
))) == SUBREG
912 && GET_CODE (SUBREG_REG (SET_SRC (PATTERN (insn
)))) == REG
913 && (REGNO (SUBREG_REG (SET_DEST (PATTERN (insn
))))
914 == REGNO (SUBREG_REG (SET_SRC (PATTERN (insn
)))))
915 && SUBREG_WORD (SET_DEST (PATTERN (insn
))) ==
916 SUBREG_WORD (SET_SRC (PATTERN (insn
)))
917 /* Insns carrying these notes are useful later on. */
918 && ! find_reg_note (insn
, REG_EQUAL
, NULL_RTX
))
920 PUT_CODE (insn
, NOTE
);
921 NOTE_LINE_NUMBER (insn
) = NOTE_INSN_DELETED
;
922 NOTE_SOURCE_FILE (insn
) = 0;
924 else if (GET_CODE (PATTERN (insn
)) == PARALLEL
)
926 /* If nothing but SETs of registers to themselves,
927 this insn can also be deleted. */
928 for (i
= 0; i
< XVECLEN (PATTERN (insn
), 0); i
++)
930 rtx tem
= XVECEXP (PATTERN (insn
), 0, i
);
932 if (GET_CODE (tem
) == USE
933 || GET_CODE (tem
) == CLOBBER
)
936 if (GET_CODE (tem
) != SET
937 || GET_CODE (SET_DEST (tem
)) != REG
938 || GET_CODE (SET_SRC (tem
)) != REG
939 || REGNO (SET_DEST (tem
)) != REGNO (SET_SRC (tem
)))
943 if (i
== XVECLEN (PATTERN (insn
), 0)
944 /* Insns carrying these notes are useful later on. */
945 && ! find_reg_note (insn
, REG_EQUAL
, NULL_RTX
))
947 PUT_CODE (insn
, NOTE
);
948 NOTE_LINE_NUMBER (insn
) = NOTE_INSN_DELETED
;
949 NOTE_SOURCE_FILE (insn
) = 0;
952 INSN_VOLATILE (insn
) = volatile_refs_p (PATTERN (insn
));
954 else if (GET_CODE (PATTERN (insn
)) != USE
)
955 INSN_VOLATILE (insn
) = volatile_refs_p (PATTERN (insn
));
956 /* A SET that makes space on the stack cannot be dead.
957 (Such SETs occur only for allocating variable-size data,
958 so they will always have a PLUS or MINUS according to the
959 direction of stack growth.)
960 Even if this function never uses this stack pointer value,
961 signal handlers do! */
962 else if (code1
== INSN
&& GET_CODE (PATTERN (insn
)) == SET
963 && SET_DEST (PATTERN (insn
)) == stack_pointer_rtx
964 #ifdef STACK_GROWS_DOWNWARD
965 && GET_CODE (SET_SRC (PATTERN (insn
))) == MINUS
967 && GET_CODE (SET_SRC (PATTERN (insn
))) == PLUS
969 && XEXP (SET_SRC (PATTERN (insn
)), 0) == stack_pointer_rtx
)
970 INSN_VOLATILE (insn
) = 1;
974 if (n_basic_blocks
> 0)
975 #ifdef EXIT_IGNORE_STACK
976 if (! EXIT_IGNORE_STACK
977 || (! FRAME_POINTER_REQUIRED
&& flag_omit_frame_pointer
))
980 /* If exiting needs the right stack value,
981 consider the stack pointer live at the end of the function. */
982 SET_REGNO_REG_SET (basic_block_live_at_end
[n_basic_blocks
- 1],
983 STACK_POINTER_REGNUM
);
984 SET_REGNO_REG_SET (basic_block_new_live_at_end
[n_basic_blocks
- 1],
985 STACK_POINTER_REGNUM
);
988 /* Mark the frame pointer is needed at the end of the function. If
989 we end up eliminating it, it will be removed from the live list
990 of each basic block by reload. */
992 if (n_basic_blocks
> 0)
994 SET_REGNO_REG_SET (basic_block_live_at_end
[n_basic_blocks
- 1],
995 FRAME_POINTER_REGNUM
);
996 SET_REGNO_REG_SET (basic_block_new_live_at_end
[n_basic_blocks
- 1],
997 FRAME_POINTER_REGNUM
);
998 #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
999 /* If they are different, also mark the hard frame pointer as live */
1000 SET_REGNO_REG_SET (basic_block_live_at_end
[n_basic_blocks
- 1],
1001 HARD_FRAME_POINTER_REGNUM
);
1002 SET_REGNO_REG_SET (basic_block_new_live_at_end
[n_basic_blocks
- 1],
1003 HARD_FRAME_POINTER_REGNUM
);
1007 /* Mark all global registers and all registers used by the epilogue
1008 as being live at the end of the function since they may be
1009 referenced by our caller. */
1011 if (n_basic_blocks
> 0)
1012 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; i
++)
1014 #ifdef EPILOGUE_USES
1015 || EPILOGUE_USES (i
)
1019 SET_REGNO_REG_SET (basic_block_live_at_end
[n_basic_blocks
- 1], i
);
1020 SET_REGNO_REG_SET (basic_block_new_live_at_end
[n_basic_blocks
- 1], i
);
1023 /* Propagate life info through the basic blocks
1024 around the graph of basic blocks.
1026 This is a relaxation process: each time a new register
1027 is live at the end of the basic block, we must scan the block
1028 to determine which registers are, as a consequence, live at the beginning
1029 of that block. These registers must then be marked live at the ends
1030 of all the blocks that can transfer control to that block.
1031 The process continues until it reaches a fixed point. */
1038 for (i
= n_basic_blocks
- 1; i
>= 0; i
--)
1040 int consider
= first_pass
;
1041 int must_rescan
= first_pass
;
1046 /* Set CONSIDER if this block needs thinking about at all
1047 (that is, if the regs live now at the end of it
1048 are not the same as were live at the end of it when
1049 we last thought about it).
1050 Set must_rescan if it needs to be thought about
1051 instruction by instruction (that is, if any additional
1052 reg that is live at the end now but was not live there before
1053 is one of the significant regs of this basic block). */
1055 EXECUTE_IF_AND_COMPL_IN_REG_SET
1056 (basic_block_new_live_at_end
[i
],
1057 basic_block_live_at_end
[i
], 0, j
,
1060 if (REGNO_REG_SET_P (basic_block_significant
[i
], j
))
1071 /* The live_at_start of this block may be changing,
1072 so another pass will be required after this one. */
1077 /* No complete rescan needed;
1078 just record those variables newly known live at end
1079 as live at start as well. */
1080 IOR_AND_COMPL_REG_SET (basic_block_live_at_start
[i
],
1081 basic_block_new_live_at_end
[i
],
1082 basic_block_live_at_end
[i
]);
1084 IOR_AND_COMPL_REG_SET (basic_block_live_at_end
[i
],
1085 basic_block_new_live_at_end
[i
],
1086 basic_block_live_at_end
[i
]);
1090 /* Update the basic_block_live_at_start
1091 by propagation backwards through the block. */
1092 COPY_REG_SET (basic_block_live_at_end
[i
],
1093 basic_block_new_live_at_end
[i
]);
1094 COPY_REG_SET (basic_block_live_at_start
[i
],
1095 basic_block_live_at_end
[i
]);
1096 propagate_block (basic_block_live_at_start
[i
],
1097 basic_block_head
[i
], basic_block_end
[i
], 0,
1098 first_pass
? basic_block_significant
[i
]
1104 register rtx jump
, head
;
1106 /* Update the basic_block_new_live_at_end's of the block
1107 that falls through into this one (if any). */
1108 head
= basic_block_head
[i
];
1109 if (basic_block_drops_in
[i
])
1110 IOR_REG_SET (basic_block_new_live_at_end
[i
-1],
1111 basic_block_live_at_start
[i
]);
1113 /* Update the basic_block_new_live_at_end's of
1114 all the blocks that jump to this one. */
1115 if (GET_CODE (head
) == CODE_LABEL
)
1116 for (jump
= LABEL_REFS (head
);
1118 jump
= LABEL_NEXTREF (jump
))
1120 register int from_block
= BLOCK_NUM (CONTAINING_INSN (jump
));
1121 IOR_REG_SET (basic_block_new_live_at_end
[from_block
],
1122 basic_block_live_at_start
[i
]);
1132 /* The only pseudos that are live at the beginning of the function are
1133 those that were not set anywhere in the function. local-alloc doesn't
1134 know how to handle these correctly, so mark them as not local to any
1137 if (n_basic_blocks
> 0)
1138 EXECUTE_IF_SET_IN_REG_SET (basic_block_live_at_start
[0],
1139 FIRST_PSEUDO_REGISTER
, i
,
1141 REG_BASIC_BLOCK (i
) = REG_BLOCK_GLOBAL
;
1144 /* Now the life information is accurate.
1145 Make one more pass over each basic block
1146 to delete dead stores, create autoincrement addressing
1147 and record how many times each register is used, is set, or dies.
1149 To save time, we operate directly in basic_block_live_at_end[i],
1150 thus destroying it (in fact, converting it into a copy of
1151 basic_block_live_at_start[i]). This is ok now because
1152 basic_block_live_at_end[i] is no longer used past this point. */
1156 for (i
= 0; i
< n_basic_blocks
; i
++)
1158 propagate_block (basic_block_live_at_end
[i
],
1159 basic_block_head
[i
], basic_block_end
[i
], 1,
1167 /* Something live during a setjmp should not be put in a register
1168 on certain machines which restore regs from stack frames
1169 rather than from the jmpbuf.
1170 But we don't need to do this for the user's variables, since
1171 ANSI says only volatile variables need this. */
1172 #ifdef LONGJMP_RESTORE_FROM_STACK
1173 EXECUTE_IF_SET_IN_REG_SET (regs_live_at_setjmp
,
1174 FIRST_PSEUDO_REGISTER
, i
,
1176 if (regno_reg_rtx
[i
] != 0
1177 && ! REG_USERVAR_P (regno_reg_rtx
[i
]))
1179 REG_LIVE_LENGTH (i
) = -1;
1180 REG_BASIC_BLOCK (i
) = -1;
1186 /* We have a problem with any pseudoreg that
1187 lives across the setjmp. ANSI says that if a
1188 user variable does not change in value
1189 between the setjmp and the longjmp, then the longjmp preserves it.
1190 This includes longjmp from a place where the pseudo appears dead.
1191 (In principle, the value still exists if it is in scope.)
1192 If the pseudo goes in a hard reg, some other value may occupy
1193 that hard reg where this pseudo is dead, thus clobbering the pseudo.
1194 Conclusion: such a pseudo must not go in a hard reg. */
1195 EXECUTE_IF_SET_IN_REG_SET (regs_live_at_setjmp
,
1196 FIRST_PSEUDO_REGISTER
, i
,
1198 if (regno_reg_rtx
[i
] != 0)
1200 REG_LIVE_LENGTH (i
) = -1;
1201 REG_BASIC_BLOCK (i
) = -1;
1206 free_regset_vector (basic_block_live_at_end
, n_basic_blocks
);
1207 free_regset_vector (basic_block_new_live_at_end
, n_basic_blocks
);
1208 free_regset_vector (basic_block_significant
, n_basic_blocks
);
1209 basic_block_live_at_end
= (regset
*)0;
1210 basic_block_new_live_at_end
= (regset
*)0;
1211 basic_block_significant
= (regset
*)0;
1213 obstack_free (&flow_obstack
, NULL_PTR
);
1216 /* Subroutines of life analysis. */
1218 /* Allocate the permanent data structures that represent the results
1219 of life analysis. Not static since used also for stupid life analysis. */
1222 allocate_for_life_analysis ()
1226 /* Recalculate the register space, in case it has grown. Old style
1227 vector oriented regsets would set regset_{size,bytes} here also. */
1228 allocate_reg_info (max_regno
, FALSE
, FALSE
);
1230 /* Because both reg_scan and flow_analysis want to set up the REG_N_SETS
1231 information, explicitly reset it here. The allocation should have
1232 already happened on the previous reg_scan pass. Make sure in case
1233 some more registers were allocated. */
1234 for (i
= 0; i
< max_regno
; i
++)
1237 basic_block_live_at_start
1238 = (regset
*) oballoc (n_basic_blocks
* sizeof (regset
));
1239 init_regset_vector (basic_block_live_at_start
, n_basic_blocks
,
1242 regs_live_at_setjmp
= OBSTACK_ALLOC_REG_SET (function_obstack
);
1243 CLEAR_REG_SET (regs_live_at_setjmp
);
1246 /* Make each element of VECTOR point at a regset. The vector has
1247 NELTS elements, and space is allocated from the ALLOC_OBSTACK
1251 init_regset_vector (vector
, nelts
, alloc_obstack
)
1254 struct obstack
*alloc_obstack
;
1258 for (i
= 0; i
< nelts
; i
++)
1260 vector
[i
] = OBSTACK_ALLOC_REG_SET (alloc_obstack
);
1261 CLEAR_REG_SET (vector
[i
]);
1265 /* Release any additional space allocated for each element of VECTOR point
1266 other than the regset header itself. The vector has NELTS elements. */
1269 free_regset_vector (vector
, nelts
)
1275 for (i
= 0; i
< nelts
; i
++)
1276 FREE_REG_SET (vector
[i
]);
1279 /* Compute the registers live at the beginning of a basic block
1280 from those live at the end.
1282 When called, OLD contains those live at the end.
1283 On return, it contains those live at the beginning.
1284 FIRST and LAST are the first and last insns of the basic block.
1286 FINAL is nonzero if we are doing the final pass which is not
1287 for computing the life info (since that has already been done)
1288 but for acting on it. On this pass, we delete dead stores,
1289 set up the logical links and dead-variables lists of instructions,
1290 and merge instructions for autoincrement and autodecrement addresses.
1292 SIGNIFICANT is nonzero only the first time for each basic block.
1293 If it is nonzero, it points to a regset in which we store
1294 a 1 for each register that is set within the block.
1296 BNUM is the number of the basic block. */
1299 propagate_block (old
, first
, last
, final
, significant
, bnum
)
1300 register regset old
;
1312 /* The following variables are used only if FINAL is nonzero. */
1313 /* This vector gets one element for each reg that has been live
1314 at any point in the basic block that has been scanned so far.
1315 SOMETIMES_MAX says how many elements are in use so far. */
1316 register int *regs_sometimes_live
;
1317 int sometimes_max
= 0;
1318 /* This regset has 1 for each reg that we have seen live so far.
1319 It and REGS_SOMETIMES_LIVE are updated together. */
1322 /* The loop depth may change in the middle of a basic block. Since we
1323 scan from end to beginning, we start with the depth at the end of the
1324 current basic block, and adjust as we pass ends and starts of loops. */
1325 loop_depth
= basic_block_loop_depth
[bnum
];
1327 dead
= ALLOCA_REG_SET ();
1328 live
= ALLOCA_REG_SET ();
1333 /* Include any notes at the end of the block in the scan.
1334 This is in case the block ends with a call to setjmp. */
1336 while (NEXT_INSN (last
) != 0 && GET_CODE (NEXT_INSN (last
)) == NOTE
)
1338 /* Look for loop boundaries, we are going forward here. */
1339 last
= NEXT_INSN (last
);
1340 if (NOTE_LINE_NUMBER (last
) == NOTE_INSN_LOOP_BEG
)
1342 else if (NOTE_LINE_NUMBER (last
) == NOTE_INSN_LOOP_END
)
1351 maxlive
= ALLOCA_REG_SET ();
1352 COPY_REG_SET (maxlive
, old
);
1353 regs_sometimes_live
= (int *) alloca (max_regno
* sizeof (int));
1355 /* Process the regs live at the end of the block.
1356 Enter them in MAXLIVE and REGS_SOMETIMES_LIVE.
1357 Also mark them as not local to any one basic block. */
1358 EXECUTE_IF_SET_IN_REG_SET (old
, 0, i
,
1360 REG_BASIC_BLOCK (i
) = REG_BLOCK_GLOBAL
;
1361 regs_sometimes_live
[sometimes_max
] = i
;
1366 /* Scan the block an insn at a time from end to beginning. */
1368 for (insn
= last
; ; insn
= prev
)
1370 prev
= PREV_INSN (insn
);
1372 if (GET_CODE (insn
) == NOTE
)
1374 /* Look for loop boundaries, remembering that we are going
1376 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_LOOP_END
)
1378 else if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_LOOP_BEG
)
1381 /* If we have LOOP_DEPTH == 0, there has been a bookkeeping error.
1382 Abort now rather than setting register status incorrectly. */
1383 if (loop_depth
== 0)
1386 /* If this is a call to `setjmp' et al,
1387 warn if any non-volatile datum is live. */
1389 if (final
&& NOTE_LINE_NUMBER (insn
) == NOTE_INSN_SETJMP
)
1390 IOR_REG_SET (regs_live_at_setjmp
, old
);
1393 /* Update the life-status of regs for this insn.
1394 First DEAD gets which regs are set in this insn
1395 then LIVE gets which regs are used in this insn.
1396 Then the regs live before the insn
1397 are those live after, with DEAD regs turned off,
1398 and then LIVE regs turned on. */
1400 else if (GET_RTX_CLASS (GET_CODE (insn
)) == 'i')
1403 rtx note
= find_reg_note (insn
, REG_RETVAL
, NULL_RTX
);
1405 = (insn_dead_p (PATTERN (insn
), old
, 0)
1406 /* Don't delete something that refers to volatile storage! */
1407 && ! INSN_VOLATILE (insn
));
1409 = (insn_is_dead
&& note
!= 0
1410 && libcall_dead_p (PATTERN (insn
), old
, note
, insn
));
1412 /* If an instruction consists of just dead store(s) on final pass,
1413 "delete" it by turning it into a NOTE of type NOTE_INSN_DELETED.
1414 We could really delete it with delete_insn, but that
1415 can cause trouble for first or last insn in a basic block. */
1416 if (final
&& insn_is_dead
)
1418 PUT_CODE (insn
, NOTE
);
1419 NOTE_LINE_NUMBER (insn
) = NOTE_INSN_DELETED
;
1420 NOTE_SOURCE_FILE (insn
) = 0;
1422 /* CC0 is now known to be dead. Either this insn used it,
1423 in which case it doesn't anymore, or clobbered it,
1424 so the next insn can't use it. */
1427 /* If this insn is copying the return value from a library call,
1428 delete the entire library call. */
1429 if (libcall_is_dead
)
1431 rtx first
= XEXP (note
, 0);
1433 while (INSN_DELETED_P (first
))
1434 first
= NEXT_INSN (first
);
1439 NOTE_LINE_NUMBER (p
) = NOTE_INSN_DELETED
;
1440 NOTE_SOURCE_FILE (p
) = 0;
1446 CLEAR_REG_SET (dead
);
1447 CLEAR_REG_SET (live
);
1449 /* See if this is an increment or decrement that can be
1450 merged into a following memory address. */
1453 register rtx x
= single_set (insn
);
1455 /* Does this instruction increment or decrement a register? */
1457 && GET_CODE (SET_DEST (x
)) == REG
1458 && (GET_CODE (SET_SRC (x
)) == PLUS
1459 || GET_CODE (SET_SRC (x
)) == MINUS
)
1460 && XEXP (SET_SRC (x
), 0) == SET_DEST (x
)
1461 && GET_CODE (XEXP (SET_SRC (x
), 1)) == CONST_INT
1462 /* Ok, look for a following memory ref we can combine with.
1463 If one is found, change the memory ref to a PRE_INC
1464 or PRE_DEC, cancel this insn, and return 1.
1465 Return 0 if nothing has been done. */
1466 && try_pre_increment_1 (insn
))
1469 #endif /* AUTO_INC_DEC */
1471 /* If this is not the final pass, and this insn is copying the
1472 value of a library call and it's dead, don't scan the
1473 insns that perform the library call, so that the call's
1474 arguments are not marked live. */
1475 if (libcall_is_dead
)
1477 /* Mark the dest reg as `significant'. */
1478 mark_set_regs (old
, dead
, PATTERN (insn
), NULL_RTX
, significant
);
1480 insn
= XEXP (note
, 0);
1481 prev
= PREV_INSN (insn
);
1483 else if (GET_CODE (PATTERN (insn
)) == SET
1484 && SET_DEST (PATTERN (insn
)) == stack_pointer_rtx
1485 && GET_CODE (SET_SRC (PATTERN (insn
))) == PLUS
1486 && XEXP (SET_SRC (PATTERN (insn
)), 0) == stack_pointer_rtx
1487 && GET_CODE (XEXP (SET_SRC (PATTERN (insn
)), 1)) == CONST_INT
)
1488 /* We have an insn to pop a constant amount off the stack.
1489 (Such insns use PLUS regardless of the direction of the stack,
1490 and any insn to adjust the stack by a constant is always a pop.)
1491 These insns, if not dead stores, have no effect on life. */
1495 /* LIVE gets the regs used in INSN;
1496 DEAD gets those set by it. Dead insns don't make anything
1499 mark_set_regs (old
, dead
, PATTERN (insn
),
1500 final
? insn
: NULL_RTX
, significant
);
1502 /* If an insn doesn't use CC0, it becomes dead since we
1503 assume that every insn clobbers it. So show it dead here;
1504 mark_used_regs will set it live if it is referenced. */
1508 mark_used_regs (old
, live
, PATTERN (insn
), final
, insn
);
1510 /* Sometimes we may have inserted something before INSN (such as
1511 a move) when we make an auto-inc. So ensure we will scan
1514 prev
= PREV_INSN (insn
);
1517 if (! insn_is_dead
&& GET_CODE (insn
) == CALL_INSN
)
1523 for (note
= CALL_INSN_FUNCTION_USAGE (insn
);
1525 note
= XEXP (note
, 1))
1526 if (GET_CODE (XEXP (note
, 0)) == USE
)
1527 mark_used_regs (old
, live
, SET_DEST (XEXP (note
, 0)),
1530 /* Each call clobbers all call-clobbered regs that are not
1531 global or fixed. Note that the function-value reg is a
1532 call-clobbered reg, and mark_set_regs has already had
1533 a chance to handle it. */
1535 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; i
++)
1536 if (call_used_regs
[i
] && ! global_regs
[i
]
1538 SET_REGNO_REG_SET (dead
, i
);
1540 /* The stack ptr is used (honorarily) by a CALL insn. */
1541 SET_REGNO_REG_SET (live
, STACK_POINTER_REGNUM
);
1543 /* Calls may also reference any of the global registers,
1544 so they are made live. */
1545 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; i
++)
1547 mark_used_regs (old
, live
,
1548 gen_rtx (REG
, reg_raw_mode
[i
], i
),
1551 /* Calls also clobber memory. */
1555 /* Update OLD for the registers used or set. */
1556 AND_COMPL_REG_SET (old
, dead
);
1557 IOR_REG_SET (old
, live
);
1559 if (GET_CODE (insn
) == CALL_INSN
&& final
)
1561 /* Any regs live at the time of a call instruction
1562 must not go in a register clobbered by calls.
1563 Find all regs now live and record this for them. */
1565 register int *p
= regs_sometimes_live
;
1567 for (i
= 0; i
< sometimes_max
; i
++, p
++)
1568 if (REGNO_REG_SET_P (old
, *p
))
1569 REG_N_CALLS_CROSSED (*p
)++;
1573 /* On final pass, add any additional sometimes-live regs
1574 into MAXLIVE and REGS_SOMETIMES_LIVE.
1575 Also update counts of how many insns each reg is live at. */
1582 EXECUTE_IF_AND_COMPL_IN_REG_SET
1583 (live
, maxlive
, 0, regno
,
1585 regs_sometimes_live
[sometimes_max
++] = regno
;
1586 SET_REGNO_REG_SET (maxlive
, regno
);
1589 p
= regs_sometimes_live
;
1590 for (i
= 0; i
< sometimes_max
; i
++)
1593 if (REGNO_REG_SET_P (old
, regno
))
1594 REG_LIVE_LENGTH (regno
)++;
1603 FREE_REG_SET (dead
);
1604 FREE_REG_SET (live
);
1606 FREE_REG_SET (maxlive
);
1608 if (num_scratch
> max_scratch
)
1609 max_scratch
= num_scratch
;
1612 /* Return 1 if X (the body of an insn, or part of it) is just dead stores
1613 (SET expressions whose destinations are registers dead after the insn).
1614 NEEDED is the regset that says which regs are alive after the insn.
1616 Unless CALL_OK is non-zero, an insn is needed if it contains a CALL. */
1619 insn_dead_p (x
, needed
, call_ok
)
1624 register RTX_CODE code
= GET_CODE (x
);
1625 /* If setting something that's a reg or part of one,
1626 see if that register's altered value will be live. */
1630 register rtx r
= SET_DEST (x
);
1631 /* A SET that is a subroutine call cannot be dead. */
1632 if (! call_ok
&& GET_CODE (SET_SRC (x
)) == CALL
)
1636 if (GET_CODE (r
) == CC0
)
1640 if (GET_CODE (r
) == MEM
&& last_mem_set
&& ! MEM_VOLATILE_P (r
)
1641 && rtx_equal_p (r
, last_mem_set
))
1644 while (GET_CODE (r
) == SUBREG
1645 || GET_CODE (r
) == STRICT_LOW_PART
1646 || GET_CODE (r
) == ZERO_EXTRACT
1647 || GET_CODE (r
) == SIGN_EXTRACT
)
1650 if (GET_CODE (r
) == REG
)
1652 register int regno
= REGNO (r
);
1654 /* Don't delete insns to set global regs. */
1655 if ((regno
< FIRST_PSEUDO_REGISTER
&& global_regs
[regno
])
1656 /* Make sure insns to set frame pointer aren't deleted. */
1657 || regno
== FRAME_POINTER_REGNUM
1658 #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
1659 || regno
== HARD_FRAME_POINTER_REGNUM
1661 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
1662 /* Make sure insns to set arg pointer are never deleted
1663 (if the arg pointer isn't fixed, there will be a USE for
1664 it, so we can treat it normally). */
1665 || (regno
== ARG_POINTER_REGNUM
&& fixed_regs
[regno
])
1667 || REGNO_REG_SET_P (needed
, regno
))
1670 /* If this is a hard register, verify that subsequent words are
1672 if (regno
< FIRST_PSEUDO_REGISTER
)
1674 int n
= HARD_REGNO_NREGS (regno
, GET_MODE (r
));
1677 if (REGNO_REG_SET_P (needed
, regno
+n
))
1684 /* If performing several activities,
1685 insn is dead if each activity is individually dead.
1686 Also, CLOBBERs and USEs can be ignored; a CLOBBER or USE
1687 that's inside a PARALLEL doesn't make the insn worth keeping. */
1688 else if (code
== PARALLEL
)
1690 register int i
= XVECLEN (x
, 0);
1691 for (i
--; i
>= 0; i
--)
1693 rtx elt
= XVECEXP (x
, 0, i
);
1694 if (!insn_dead_p (elt
, needed
, call_ok
)
1695 && GET_CODE (elt
) != CLOBBER
1696 && GET_CODE (elt
) != USE
)
1701 /* We do not check CLOBBER or USE here.
1702 An insn consisting of just a CLOBBER or just a USE
1703 should not be deleted. */
1707 /* If X is the pattern of the last insn in a libcall, and assuming X is dead,
1708 return 1 if the entire library call is dead.
1709 This is true if X copies a register (hard or pseudo)
1710 and if the hard return reg of the call insn is dead.
1711 (The caller should have tested the destination of X already for death.)
1713 If this insn doesn't just copy a register, then we don't
1714 have an ordinary libcall. In that case, cse could not have
1715 managed to substitute the source for the dest later on,
1716 so we can assume the libcall is dead.
1718 NEEDED is the bit vector of pseudoregs live before this insn.
1719 NOTE is the REG_RETVAL note of the insn. INSN is the insn itself. */
1722 libcall_dead_p (x
, needed
, note
, insn
)
1728 register RTX_CODE code
= GET_CODE (x
);
1732 register rtx r
= SET_SRC (x
);
1733 if (GET_CODE (r
) == REG
)
1735 rtx call
= XEXP (note
, 0);
1738 /* Find the call insn. */
1739 while (call
!= insn
&& GET_CODE (call
) != CALL_INSN
)
1740 call
= NEXT_INSN (call
);
1742 /* If there is none, do nothing special,
1743 since ordinary death handling can understand these insns. */
1747 /* See if the hard reg holding the value is dead.
1748 If this is a PARALLEL, find the call within it. */
1749 call
= PATTERN (call
);
1750 if (GET_CODE (call
) == PARALLEL
)
1752 for (i
= XVECLEN (call
, 0) - 1; i
>= 0; i
--)
1753 if (GET_CODE (XVECEXP (call
, 0, i
)) == SET
1754 && GET_CODE (SET_SRC (XVECEXP (call
, 0, i
))) == CALL
)
1757 /* This may be a library call that is returning a value
1758 via invisible pointer. Do nothing special, since
1759 ordinary death handling can understand these insns. */
1763 call
= XVECEXP (call
, 0, i
);
1766 return insn_dead_p (call
, needed
, 1);
1772 /* Return 1 if register REGNO was used before it was set.
1773 In other words, if it is live at function entry.
1774 Don't count global register variables or variables in registers
1775 that can be used for function arg passing, though. */
1778 regno_uninitialized (regno
)
1781 if (n_basic_blocks
== 0
1782 || (regno
< FIRST_PSEUDO_REGISTER
1783 && (global_regs
[regno
] || FUNCTION_ARG_REGNO_P (regno
))))
1786 return REGNO_REG_SET_P (basic_block_live_at_start
[0], regno
);
1789 /* 1 if register REGNO was alive at a place where `setjmp' was called
1790 and was set more than once or is an argument.
1791 Such regs may be clobbered by `longjmp'. */
1794 regno_clobbered_at_setjmp (regno
)
1797 if (n_basic_blocks
== 0)
1800 return ((REG_N_SETS (regno
) > 1
1801 || REGNO_REG_SET_P (basic_block_live_at_start
[0], regno
))
1802 && REGNO_REG_SET_P (regs_live_at_setjmp
, regno
));
1805 /* Process the registers that are set within X.
1806 Their bits are set to 1 in the regset DEAD,
1807 because they are dead prior to this insn.
1809 If INSN is nonzero, it is the insn being processed
1810 and the fact that it is nonzero implies this is the FINAL pass
1811 in propagate_block. In this case, various info about register
1812 usage is stored, LOG_LINKS fields of insns are set up. */
1815 mark_set_regs (needed
, dead
, x
, insn
, significant
)
1822 register RTX_CODE code
= GET_CODE (x
);
1824 if (code
== SET
|| code
== CLOBBER
)
1825 mark_set_1 (needed
, dead
, x
, insn
, significant
);
1826 else if (code
== PARALLEL
)
1829 for (i
= XVECLEN (x
, 0) - 1; i
>= 0; i
--)
1831 code
= GET_CODE (XVECEXP (x
, 0, i
));
1832 if (code
== SET
|| code
== CLOBBER
)
1833 mark_set_1 (needed
, dead
, XVECEXP (x
, 0, i
), insn
, significant
);
1838 /* Process a single SET rtx, X. */
1841 mark_set_1 (needed
, dead
, x
, insn
, significant
)
1849 register rtx reg
= SET_DEST (x
);
1851 /* Modifying just one hardware register of a multi-reg value
1852 or just a byte field of a register
1853 does not mean the value from before this insn is now dead.
1854 But it does mean liveness of that register at the end of the block
1857 Within mark_set_1, however, we treat it as if the register is
1858 indeed modified. mark_used_regs will, however, also treat this
1859 register as being used. Thus, we treat these insns as setting a
1860 new value for the register as a function of its old value. This
1861 cases LOG_LINKS to be made appropriately and this will help combine. */
1863 while (GET_CODE (reg
) == SUBREG
|| GET_CODE (reg
) == ZERO_EXTRACT
1864 || GET_CODE (reg
) == SIGN_EXTRACT
1865 || GET_CODE (reg
) == STRICT_LOW_PART
)
1866 reg
= XEXP (reg
, 0);
1868 /* If we are writing into memory or into a register mentioned in the
1869 address of the last thing stored into memory, show we don't know
1870 what the last store was. If we are writing memory, save the address
1871 unless it is volatile. */
1872 if (GET_CODE (reg
) == MEM
1873 || (GET_CODE (reg
) == REG
1874 && last_mem_set
!= 0 && reg_overlap_mentioned_p (reg
, last_mem_set
)))
1877 if (GET_CODE (reg
) == MEM
&& ! side_effects_p (reg
)
1878 /* There are no REG_INC notes for SP, so we can't assume we'll see
1879 everything that invalidates it. To be safe, don't eliminate any
1880 stores though SP; none of them should be redundant anyway. */
1881 && ! reg_mentioned_p (stack_pointer_rtx
, reg
))
1884 if (GET_CODE (reg
) == REG
1885 && (regno
= REGNO (reg
), regno
!= FRAME_POINTER_REGNUM
)
1886 #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
1887 && regno
!= HARD_FRAME_POINTER_REGNUM
1889 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
1890 && ! (regno
== ARG_POINTER_REGNUM
&& fixed_regs
[regno
])
1892 && ! (regno
< FIRST_PSEUDO_REGISTER
&& global_regs
[regno
]))
1893 /* && regno != STACK_POINTER_REGNUM) -- let's try without this. */
1895 int some_needed
= REGNO_REG_SET_P (needed
, regno
);
1896 int some_not_needed
= ! some_needed
;
1898 /* Mark it as a significant register for this basic block. */
1900 SET_REGNO_REG_SET (significant
, regno
);
1902 /* Mark it as as dead before this insn. */
1903 SET_REGNO_REG_SET (dead
, regno
);
1905 /* A hard reg in a wide mode may really be multiple registers.
1906 If so, mark all of them just like the first. */
1907 if (regno
< FIRST_PSEUDO_REGISTER
)
1911 /* Nothing below is needed for the stack pointer; get out asap.
1912 Eg, log links aren't needed, since combine won't use them. */
1913 if (regno
== STACK_POINTER_REGNUM
)
1916 n
= HARD_REGNO_NREGS (regno
, GET_MODE (reg
));
1919 int regno_n
= regno
+ n
;
1920 int needed_regno
= REGNO_REG_SET_P (needed
, regno_n
);
1922 SET_REGNO_REG_SET (significant
, regno_n
);
1924 SET_REGNO_REG_SET (dead
, regno_n
);
1925 some_needed
|= needed_regno
;
1926 some_not_needed
|= ! needed_regno
;
1929 /* Additional data to record if this is the final pass. */
1932 register rtx y
= reg_next_use
[regno
];
1933 register int blocknum
= BLOCK_NUM (insn
);
1935 /* If this is a hard reg, record this function uses the reg. */
1937 if (regno
< FIRST_PSEUDO_REGISTER
)
1940 int endregno
= regno
+ HARD_REGNO_NREGS (regno
, GET_MODE (reg
));
1942 for (i
= regno
; i
< endregno
; i
++)
1944 /* The next use is no longer "next", since a store
1946 reg_next_use
[i
] = 0;
1948 regs_ever_live
[i
] = 1;
1954 /* The next use is no longer "next", since a store
1956 reg_next_use
[regno
] = 0;
1958 /* Keep track of which basic blocks each reg appears in. */
1960 if (REG_BASIC_BLOCK (regno
) == REG_BLOCK_UNKNOWN
)
1961 REG_BASIC_BLOCK (regno
) = blocknum
;
1962 else if (REG_BASIC_BLOCK (regno
) != blocknum
)
1963 REG_BASIC_BLOCK (regno
) = REG_BLOCK_GLOBAL
;
1965 /* Count (weighted) references, stores, etc. This counts a
1966 register twice if it is modified, but that is correct. */
1967 REG_N_SETS (regno
)++;
1969 REG_N_REFS (regno
) += loop_depth
;
1971 /* The insns where a reg is live are normally counted
1972 elsewhere, but we want the count to include the insn
1973 where the reg is set, and the normal counting mechanism
1974 would not count it. */
1975 REG_LIVE_LENGTH (regno
)++;
1978 if (! some_not_needed
)
1980 /* Make a logical link from the next following insn
1981 that uses this register, back to this insn.
1982 The following insns have already been processed.
1984 We don't build a LOG_LINK for hard registers containing
1985 in ASM_OPERANDs. If these registers get replaced,
1986 we might wind up changing the semantics of the insn,
1987 even if reload can make what appear to be valid assignments
1989 if (y
&& (BLOCK_NUM (y
) == blocknum
)
1990 && (regno
>= FIRST_PSEUDO_REGISTER
1991 || asm_noperands (PATTERN (y
)) < 0))
1993 = gen_rtx (INSN_LIST
, VOIDmode
, insn
, LOG_LINKS (y
));
1995 else if (! some_needed
)
1997 /* Note that dead stores have already been deleted when possible
1998 If we get here, we have found a dead store that cannot
1999 be eliminated (because the same insn does something useful).
2000 Indicate this by marking the reg being set as dying here. */
2002 = gen_rtx (EXPR_LIST
, REG_UNUSED
, reg
, REG_NOTES (insn
));
2003 REG_N_DEATHS (REGNO (reg
))++;
2007 /* This is a case where we have a multi-word hard register
2008 and some, but not all, of the words of the register are
2009 needed in subsequent insns. Write REG_UNUSED notes
2010 for those parts that were not needed. This case should
2015 for (i
= HARD_REGNO_NREGS (regno
, GET_MODE (reg
)) - 1;
2017 if (!REGNO_REG_SET_P (needed
, regno
+ i
))
2019 = gen_rtx (EXPR_LIST
, REG_UNUSED
,
2020 gen_rtx (REG
, reg_raw_mode
[regno
+ i
],
2026 else if (GET_CODE (reg
) == REG
)
2027 reg_next_use
[regno
] = 0;
2029 /* If this is the last pass and this is a SCRATCH, show it will be dying
2030 here and count it. */
2031 else if (GET_CODE (reg
) == SCRATCH
&& insn
!= 0)
2034 = gen_rtx (EXPR_LIST
, REG_UNUSED
, reg
, REG_NOTES (insn
));
2041 /* X is a MEM found in INSN. See if we can convert it into an auto-increment
2045 find_auto_inc (needed
, x
, insn
)
2050 rtx addr
= XEXP (x
, 0);
2051 HOST_WIDE_INT offset
= 0;
2054 /* Here we detect use of an index register which might be good for
2055 postincrement, postdecrement, preincrement, or predecrement. */
2057 if (GET_CODE (addr
) == PLUS
&& GET_CODE (XEXP (addr
, 1)) == CONST_INT
)
2058 offset
= INTVAL (XEXP (addr
, 1)), addr
= XEXP (addr
, 0);
2060 if (GET_CODE (addr
) == REG
)
2063 register int size
= GET_MODE_SIZE (GET_MODE (x
));
2066 int regno
= REGNO (addr
);
2068 /* Is the next use an increment that might make auto-increment? */
2069 if ((incr
= reg_next_use
[regno
]) != 0
2070 && (set
= single_set (incr
)) != 0
2071 && GET_CODE (set
) == SET
2072 && BLOCK_NUM (incr
) == BLOCK_NUM (insn
)
2073 /* Can't add side effects to jumps; if reg is spilled and
2074 reloaded, there's no way to store back the altered value. */
2075 && GET_CODE (insn
) != JUMP_INSN
2076 && (y
= SET_SRC (set
), GET_CODE (y
) == PLUS
)
2077 && XEXP (y
, 0) == addr
2078 && GET_CODE (XEXP (y
, 1)) == CONST_INT
2080 #ifdef HAVE_POST_INCREMENT
2081 || (INTVAL (XEXP (y
, 1)) == size
&& offset
== 0)
2083 #ifdef HAVE_POST_DECREMENT
2084 || (INTVAL (XEXP (y
, 1)) == - size
&& offset
== 0)
2086 #ifdef HAVE_PRE_INCREMENT
2087 || (INTVAL (XEXP (y
, 1)) == size
&& offset
== size
)
2089 #ifdef HAVE_PRE_DECREMENT
2090 || (INTVAL (XEXP (y
, 1)) == - size
&& offset
== - size
)
2093 /* Make sure this reg appears only once in this insn. */
2094 && (use
= find_use_as_address (PATTERN (insn
), addr
, offset
),
2095 use
!= 0 && use
!= (rtx
) 1))
2097 rtx q
= SET_DEST (set
);
2098 enum rtx_code inc_code
= (INTVAL (XEXP (y
, 1)) == size
2099 ? (offset
? PRE_INC
: POST_INC
)
2100 : (offset
? PRE_DEC
: POST_DEC
));
2102 if (dead_or_set_p (incr
, addr
))
2104 /* This is the simple case. Try to make the auto-inc. If
2105 we can't, we are done. Otherwise, we will do any
2106 needed updates below. */
2107 if (! validate_change (insn
, &XEXP (x
, 0),
2108 gen_rtx (inc_code
, Pmode
, addr
),
2112 else if (GET_CODE (q
) == REG
2113 /* PREV_INSN used here to check the semi-open interval
2115 && ! reg_used_between_p (q
, PREV_INSN (insn
), incr
)
2116 /* We must also check for sets of q as q may be
2117 a call clobbered hard register and there may
2118 be a call between PREV_INSN (insn) and incr. */
2119 && ! reg_set_between_p (q
, PREV_INSN (insn
), incr
))
2121 /* We have *p followed sometime later by q = p+size.
2122 Both p and q must be live afterward,
2123 and q is not used between INSN and it's assignment.
2124 Change it to q = p, ...*q..., q = q+size.
2125 Then fall into the usual case. */
2129 emit_move_insn (q
, addr
);
2130 insns
= get_insns ();
2133 /* If anything in INSNS have UID's that don't fit within the
2134 extra space we allocate earlier, we can't make this auto-inc.
2135 This should never happen. */
2136 for (temp
= insns
; temp
; temp
= NEXT_INSN (temp
))
2138 if (INSN_UID (temp
) > max_uid_for_flow
)
2140 BLOCK_NUM (temp
) = BLOCK_NUM (insn
);
2143 /* If we can't make the auto-inc, or can't make the
2144 replacement into Y, exit. There's no point in making
2145 the change below if we can't do the auto-inc and doing
2146 so is not correct in the pre-inc case. */
2148 validate_change (insn
, &XEXP (x
, 0),
2149 gen_rtx (inc_code
, Pmode
, q
),
2151 validate_change (incr
, &XEXP (y
, 0), q
, 1);
2152 if (! apply_change_group ())
2155 /* We now know we'll be doing this change, so emit the
2156 new insn(s) and do the updates. */
2157 emit_insns_before (insns
, insn
);
2159 if (basic_block_head
[BLOCK_NUM (insn
)] == insn
)
2160 basic_block_head
[BLOCK_NUM (insn
)] = insns
;
2162 /* INCR will become a NOTE and INSN won't contain a
2163 use of ADDR. If a use of ADDR was just placed in
2164 the insn before INSN, make that the next use.
2165 Otherwise, invalidate it. */
2166 if (GET_CODE (PREV_INSN (insn
)) == INSN
2167 && GET_CODE (PATTERN (PREV_INSN (insn
))) == SET
2168 && SET_SRC (PATTERN (PREV_INSN (insn
))) == addr
)
2169 reg_next_use
[regno
] = PREV_INSN (insn
);
2171 reg_next_use
[regno
] = 0;
2176 /* REGNO is now used in INCR which is below INSN, but
2177 it previously wasn't live here. If we don't mark
2178 it as needed, we'll put a REG_DEAD note for it
2179 on this insn, which is incorrect. */
2180 SET_REGNO_REG_SET (needed
, regno
);
2182 /* If there are any calls between INSN and INCR, show
2183 that REGNO now crosses them. */
2184 for (temp
= insn
; temp
!= incr
; temp
= NEXT_INSN (temp
))
2185 if (GET_CODE (temp
) == CALL_INSN
)
2186 REG_N_CALLS_CROSSED (regno
)++;
2191 /* If we haven't returned, it means we were able to make the
2192 auto-inc, so update the status. First, record that this insn
2193 has an implicit side effect. */
2196 = gen_rtx (EXPR_LIST
, REG_INC
, addr
, REG_NOTES (insn
));
2198 /* Modify the old increment-insn to simply copy
2199 the already-incremented value of our register. */
2200 if (! validate_change (incr
, &SET_SRC (set
), addr
, 0))
2203 /* If that makes it a no-op (copying the register into itself) delete
2204 it so it won't appear to be a "use" and a "set" of this
2206 if (SET_DEST (set
) == addr
)
2208 PUT_CODE (incr
, NOTE
);
2209 NOTE_LINE_NUMBER (incr
) = NOTE_INSN_DELETED
;
2210 NOTE_SOURCE_FILE (incr
) = 0;
2213 if (regno
>= FIRST_PSEUDO_REGISTER
)
2215 /* Count an extra reference to the reg. When a reg is
2216 incremented, spilling it is worse, so we want to make
2217 that less likely. */
2218 REG_N_REFS (regno
) += loop_depth
;
2220 /* Count the increment as a setting of the register,
2221 even though it isn't a SET in rtl. */
2222 REG_N_SETS (regno
)++;
2227 #endif /* AUTO_INC_DEC */
2229 /* Scan expression X and store a 1-bit in LIVE for each reg it uses.
2230 This is done assuming the registers needed from X
2231 are those that have 1-bits in NEEDED.
2233 On the final pass, FINAL is 1. This means try for autoincrement
2234 and count the uses and deaths of each pseudo-reg.
2236 INSN is the containing instruction. If INSN is dead, this function is not
2240 mark_used_regs (needed
, live
, x
, final
, insn
)
2247 register RTX_CODE code
;
2252 code
= GET_CODE (x
);
2273 /* If we are clobbering a MEM, mark any registers inside the address
2275 if (GET_CODE (XEXP (x
, 0)) == MEM
)
2276 mark_used_regs (needed
, live
, XEXP (XEXP (x
, 0), 0), final
, insn
);
2280 /* Invalidate the data for the last MEM stored, but only if MEM is
2281 something that can be stored into. */
2282 if (GET_CODE (XEXP (x
, 0)) == SYMBOL_REF
2283 && CONSTANT_POOL_ADDRESS_P (XEXP (x
, 0)))
2284 ; /* needn't clear last_mem_set */
2290 find_auto_inc (needed
, x
, insn
);
2295 if (GET_CODE (SUBREG_REG (x
)) == REG
2296 && REGNO (SUBREG_REG (x
)) >= FIRST_PSEUDO_REGISTER
2297 && (GET_MODE_SIZE (GET_MODE (x
))
2298 != GET_MODE_SIZE (GET_MODE (SUBREG_REG (x
)))))
2299 REG_CHANGES_SIZE (REGNO (SUBREG_REG (x
))) = 1;
2301 /* While we're here, optimize this case. */
2304 /* In case the SUBREG is not of a register, don't optimize */
2305 if (GET_CODE (x
) != REG
)
2307 mark_used_regs (needed
, live
, x
, final
, insn
);
2311 /* ... fall through ... */
2314 /* See a register other than being set
2315 => mark it as needed. */
2319 int some_needed
= REGNO_REG_SET_P (needed
, regno
);
2320 int some_not_needed
= ! some_needed
;
2322 SET_REGNO_REG_SET (live
, regno
);
2324 /* A hard reg in a wide mode may really be multiple registers.
2325 If so, mark all of them just like the first. */
2326 if (regno
< FIRST_PSEUDO_REGISTER
)
2330 /* For stack ptr or fixed arg pointer,
2331 nothing below can be necessary, so waste no more time. */
2332 if (regno
== STACK_POINTER_REGNUM
2333 #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
2334 || regno
== HARD_FRAME_POINTER_REGNUM
2336 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
2337 || (regno
== ARG_POINTER_REGNUM
&& fixed_regs
[regno
])
2339 || regno
== FRAME_POINTER_REGNUM
)
2341 /* If this is a register we are going to try to eliminate,
2342 don't mark it live here. If we are successful in
2343 eliminating it, it need not be live unless it is used for
2344 pseudos, in which case it will have been set live when
2345 it was allocated to the pseudos. If the register will not
2346 be eliminated, reload will set it live at that point. */
2348 if (! TEST_HARD_REG_BIT (elim_reg_set
, regno
))
2349 regs_ever_live
[regno
] = 1;
2352 /* No death notes for global register variables;
2353 their values are live after this function exits. */
2354 if (global_regs
[regno
])
2357 reg_next_use
[regno
] = insn
;
2361 n
= HARD_REGNO_NREGS (regno
, GET_MODE (x
));
2364 int regno_n
= regno
+ n
;
2365 int needed_regno
= REGNO_REG_SET_P (needed
, regno_n
);
2367 SET_REGNO_REG_SET (live
, regno_n
);
2368 some_needed
|= needed_regno
;
2369 some_not_needed
|= ! needed_regno
;
2374 /* Record where each reg is used, so when the reg
2375 is set we know the next insn that uses it. */
2377 reg_next_use
[regno
] = insn
;
2379 if (regno
< FIRST_PSEUDO_REGISTER
)
2381 /* If a hard reg is being used,
2382 record that this function does use it. */
2384 i
= HARD_REGNO_NREGS (regno
, GET_MODE (x
));
2388 regs_ever_live
[regno
+ --i
] = 1;
2393 /* Keep track of which basic block each reg appears in. */
2395 register int blocknum
= BLOCK_NUM (insn
);
2397 if (REG_BASIC_BLOCK (regno
) == REG_BLOCK_UNKNOWN
)
2398 REG_BASIC_BLOCK (regno
) = blocknum
;
2399 else if (REG_BASIC_BLOCK (regno
) != blocknum
)
2400 REG_BASIC_BLOCK (regno
) = REG_BLOCK_GLOBAL
;
2402 /* Count (weighted) number of uses of each reg. */
2404 REG_N_REFS (regno
) += loop_depth
;
2407 /* Record and count the insns in which a reg dies.
2408 If it is used in this insn and was dead below the insn
2409 then it dies in this insn. If it was set in this insn,
2410 we do not make a REG_DEAD note; likewise if we already
2411 made such a note. */
2414 && ! dead_or_set_p (insn
, x
)
2416 && (regno
>= FIRST_PSEUDO_REGISTER
|| ! fixed_regs
[regno
])
2420 /* Check for the case where the register dying partially
2421 overlaps the register set by this insn. */
2422 if (regno
< FIRST_PSEUDO_REGISTER
2423 && HARD_REGNO_NREGS (regno
, GET_MODE (x
)) > 1)
2425 int n
= HARD_REGNO_NREGS (regno
, GET_MODE (x
));
2427 some_needed
|= dead_or_set_regno_p (insn
, regno
+ n
);
2430 /* If none of the words in X is needed, make a REG_DEAD
2431 note. Otherwise, we must make partial REG_DEAD notes. */
2435 = gen_rtx (EXPR_LIST
, REG_DEAD
, x
, REG_NOTES (insn
));
2436 REG_N_DEATHS (regno
)++;
2442 /* Don't make a REG_DEAD note for a part of a register
2443 that is set in the insn. */
2445 for (i
= HARD_REGNO_NREGS (regno
, GET_MODE (x
)) - 1;
2447 if (!REGNO_REG_SET_P (needed
, regno
+ i
)
2448 && ! dead_or_set_regno_p (insn
, regno
+ i
))
2450 = gen_rtx (EXPR_LIST
, REG_DEAD
,
2451 gen_rtx (REG
, reg_raw_mode
[regno
+ i
],
2462 register rtx testreg
= SET_DEST (x
);
2465 /* If storing into MEM, don't show it as being used. But do
2466 show the address as being used. */
2467 if (GET_CODE (testreg
) == MEM
)
2471 find_auto_inc (needed
, testreg
, insn
);
2473 mark_used_regs (needed
, live
, XEXP (testreg
, 0), final
, insn
);
2474 mark_used_regs (needed
, live
, SET_SRC (x
), final
, insn
);
2478 /* Storing in STRICT_LOW_PART is like storing in a reg
2479 in that this SET might be dead, so ignore it in TESTREG.
2480 but in some other ways it is like using the reg.
2482 Storing in a SUBREG or a bit field is like storing the entire
2483 register in that if the register's value is not used
2484 then this SET is not needed. */
2485 while (GET_CODE (testreg
) == STRICT_LOW_PART
2486 || GET_CODE (testreg
) == ZERO_EXTRACT
2487 || GET_CODE (testreg
) == SIGN_EXTRACT
2488 || GET_CODE (testreg
) == SUBREG
)
2490 if (GET_CODE (testreg
) == SUBREG
2491 && GET_CODE (SUBREG_REG (testreg
)) == REG
2492 && REGNO (SUBREG_REG (testreg
)) >= FIRST_PSEUDO_REGISTER
2493 && (GET_MODE_SIZE (GET_MODE (testreg
))
2494 != GET_MODE_SIZE (GET_MODE (SUBREG_REG (testreg
)))))
2495 REG_CHANGES_SIZE (REGNO (SUBREG_REG (testreg
))) = 1;
2497 /* Modifying a single register in an alternate mode
2498 does not use any of the old value. But these other
2499 ways of storing in a register do use the old value. */
2500 if (GET_CODE (testreg
) == SUBREG
2501 && !(REG_SIZE (SUBREG_REG (testreg
)) > REG_SIZE (testreg
)))
2506 testreg
= XEXP (testreg
, 0);
2509 /* If this is a store into a register,
2510 recursively scan the value being stored. */
2512 if (GET_CODE (testreg
) == REG
2513 && (regno
= REGNO (testreg
), regno
!= FRAME_POINTER_REGNUM
)
2514 #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
2515 && regno
!= HARD_FRAME_POINTER_REGNUM
2517 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
2518 && ! (regno
== ARG_POINTER_REGNUM
&& fixed_regs
[regno
])
2521 /* We used to exclude global_regs here, but that seems wrong.
2522 Storing in them is like storing in mem. */
2524 mark_used_regs (needed
, live
, SET_SRC (x
), final
, insn
);
2526 mark_used_regs (needed
, live
, SET_DEST (x
), final
, insn
);
2533 /* If exiting needs the right stack value, consider this insn as
2534 using the stack pointer. In any event, consider it as using
2535 all global registers and all registers used by return. */
2537 #ifdef EXIT_IGNORE_STACK
2538 if (! EXIT_IGNORE_STACK
2539 || (! FRAME_POINTER_REQUIRED
&& flag_omit_frame_pointer
))
2541 SET_REGNO_REG_SET (live
, STACK_POINTER_REGNUM
);
2543 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; i
++)
2545 #ifdef EPILOGUE_USES
2546 || EPILOGUE_USES (i
)
2549 SET_REGNO_REG_SET (live
, i
);
2556 /* Recursively scan the operands of this expression. */
2559 register char *fmt
= GET_RTX_FORMAT (code
);
2562 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
2566 /* Tail recursive case: save a function call level. */
2572 mark_used_regs (needed
, live
, XEXP (x
, i
), final
, insn
);
2574 else if (fmt
[i
] == 'E')
2577 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
2578 mark_used_regs (needed
, live
, XVECEXP (x
, i
, j
), final
, insn
);
2587 try_pre_increment_1 (insn
)
2590 /* Find the next use of this reg. If in same basic block,
2591 make it do pre-increment or pre-decrement if appropriate. */
2592 rtx x
= single_set (insn
);
2593 HOST_WIDE_INT amount
= ((GET_CODE (SET_SRC (x
)) == PLUS
? 1 : -1)
2594 * INTVAL (XEXP (SET_SRC (x
), 1)));
2595 int regno
= REGNO (SET_DEST (x
));
2596 rtx y
= reg_next_use
[regno
];
2598 && BLOCK_NUM (y
) == BLOCK_NUM (insn
)
2599 /* Don't do this if the reg dies, or gets set in y; a standard addressing
2600 mode would be better. */
2601 && ! dead_or_set_p (y
, SET_DEST (x
))
2602 && try_pre_increment (y
, SET_DEST (x
), amount
))
2604 /* We have found a suitable auto-increment
2605 and already changed insn Y to do it.
2606 So flush this increment-instruction. */
2607 PUT_CODE (insn
, NOTE
);
2608 NOTE_LINE_NUMBER (insn
) = NOTE_INSN_DELETED
;
2609 NOTE_SOURCE_FILE (insn
) = 0;
2610 /* Count a reference to this reg for the increment
2611 insn we are deleting. When a reg is incremented.
2612 spilling it is worse, so we want to make that
2614 if (regno
>= FIRST_PSEUDO_REGISTER
)
2616 REG_N_REFS (regno
) += loop_depth
;
2617 REG_N_SETS (regno
)++;
2624 /* Try to change INSN so that it does pre-increment or pre-decrement
2625 addressing on register REG in order to add AMOUNT to REG.
2626 AMOUNT is negative for pre-decrement.
2627 Returns 1 if the change could be made.
2628 This checks all about the validity of the result of modifying INSN. */
2631 try_pre_increment (insn
, reg
, amount
)
2633 HOST_WIDE_INT amount
;
2637 /* Nonzero if we can try to make a pre-increment or pre-decrement.
2638 For example, addl $4,r1; movl (r1),... can become movl +(r1),... */
2640 /* Nonzero if we can try to make a post-increment or post-decrement.
2641 For example, addl $4,r1; movl -4(r1),... can become movl (r1)+,...
2642 It is possible for both PRE_OK and POST_OK to be nonzero if the machine
2643 supports both pre-inc and post-inc, or both pre-dec and post-dec. */
2646 /* Nonzero if the opportunity actually requires post-inc or post-dec. */
2649 /* From the sign of increment, see which possibilities are conceivable
2650 on this target machine. */
2651 #ifdef HAVE_PRE_INCREMENT
2655 #ifdef HAVE_POST_INCREMENT
2660 #ifdef HAVE_PRE_DECREMENT
2664 #ifdef HAVE_POST_DECREMENT
2669 if (! (pre_ok
|| post_ok
))
2672 /* It is not safe to add a side effect to a jump insn
2673 because if the incremented register is spilled and must be reloaded
2674 there would be no way to store the incremented value back in memory. */
2676 if (GET_CODE (insn
) == JUMP_INSN
)
2681 use
= find_use_as_address (PATTERN (insn
), reg
, 0);
2682 if (post_ok
&& (use
== 0 || use
== (rtx
) 1))
2684 use
= find_use_as_address (PATTERN (insn
), reg
, -amount
);
2688 if (use
== 0 || use
== (rtx
) 1)
2691 if (GET_MODE_SIZE (GET_MODE (use
)) != (amount
> 0 ? amount
: - amount
))
2694 /* See if this combination of instruction and addressing mode exists. */
2695 if (! validate_change (insn
, &XEXP (use
, 0),
2697 ? (do_post
? POST_INC
: PRE_INC
)
2698 : (do_post
? POST_DEC
: PRE_DEC
),
2702 /* Record that this insn now has an implicit side effect on X. */
2703 REG_NOTES (insn
) = gen_rtx (EXPR_LIST
, REG_INC
, reg
, REG_NOTES (insn
));
2707 #endif /* AUTO_INC_DEC */
2709 /* Find the place in the rtx X where REG is used as a memory address.
2710 Return the MEM rtx that so uses it.
2711 If PLUSCONST is nonzero, search instead for a memory address equivalent to
2712 (plus REG (const_int PLUSCONST)).
2714 If such an address does not appear, return 0.
2715 If REG appears more than once, or is used other than in such an address,
2719 find_use_as_address (x
, reg
, plusconst
)
2722 HOST_WIDE_INT plusconst
;
2724 enum rtx_code code
= GET_CODE (x
);
2725 char *fmt
= GET_RTX_FORMAT (code
);
2727 register rtx value
= 0;
2730 if (code
== MEM
&& XEXP (x
, 0) == reg
&& plusconst
== 0)
2733 if (code
== MEM
&& GET_CODE (XEXP (x
, 0)) == PLUS
2734 && XEXP (XEXP (x
, 0), 0) == reg
2735 && GET_CODE (XEXP (XEXP (x
, 0), 1)) == CONST_INT
2736 && INTVAL (XEXP (XEXP (x
, 0), 1)) == plusconst
)
2739 if (code
== SIGN_EXTRACT
|| code
== ZERO_EXTRACT
)
2741 /* If REG occurs inside a MEM used in a bit-field reference,
2742 that is unacceptable. */
2743 if (find_use_as_address (XEXP (x
, 0), reg
, 0) != 0)
2744 return (rtx
) (HOST_WIDE_INT
) 1;
2748 return (rtx
) (HOST_WIDE_INT
) 1;
2750 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
2754 tem
= find_use_as_address (XEXP (x
, i
), reg
, plusconst
);
2758 return (rtx
) (HOST_WIDE_INT
) 1;
2763 for (j
= XVECLEN (x
, i
) - 1; j
>= 0; j
--)
2765 tem
= find_use_as_address (XVECEXP (x
, i
, j
), reg
, plusconst
);
2769 return (rtx
) (HOST_WIDE_INT
) 1;
2777 /* Write information about registers and basic blocks into FILE.
2778 This is part of making a debugging dump. */
2781 dump_flow_info (file
)
2785 static char *reg_class_names
[] = REG_CLASS_NAMES
;
2787 fprintf (file
, "%d registers.\n", max_regno
);
2789 for (i
= FIRST_PSEUDO_REGISTER
; i
< max_regno
; i
++)
2792 enum reg_class
class, altclass
;
2793 fprintf (file
, "\nRegister %d used %d times across %d insns",
2794 i
, REG_N_REFS (i
), REG_LIVE_LENGTH (i
));
2795 if (REG_BASIC_BLOCK (i
) >= 0)
2796 fprintf (file
, " in block %d", REG_BASIC_BLOCK (i
));
2797 if (REG_N_DEATHS (i
) != 1)
2798 fprintf (file
, "; dies in %d places", REG_N_DEATHS (i
));
2799 if (REG_N_CALLS_CROSSED (i
) == 1)
2800 fprintf (file
, "; crosses 1 call");
2801 else if (REG_N_CALLS_CROSSED (i
))
2802 fprintf (file
, "; crosses %d calls", REG_N_CALLS_CROSSED (i
));
2803 if (PSEUDO_REGNO_BYTES (i
) != UNITS_PER_WORD
)
2804 fprintf (file
, "; %d bytes", PSEUDO_REGNO_BYTES (i
));
2805 class = reg_preferred_class (i
);
2806 altclass
= reg_alternate_class (i
);
2807 if (class != GENERAL_REGS
|| altclass
!= ALL_REGS
)
2809 if (altclass
== ALL_REGS
|| class == ALL_REGS
)
2810 fprintf (file
, "; pref %s", reg_class_names
[(int) class]);
2811 else if (altclass
== NO_REGS
)
2812 fprintf (file
, "; %s or none", reg_class_names
[(int) class]);
2814 fprintf (file
, "; pref %s, else %s",
2815 reg_class_names
[(int) class],
2816 reg_class_names
[(int) altclass
]);
2818 if (REGNO_POINTER_FLAG (i
))
2819 fprintf (file
, "; pointer");
2820 fprintf (file
, ".\n");
2822 fprintf (file
, "\n%d basic blocks.\n", n_basic_blocks
);
2823 for (i
= 0; i
< n_basic_blocks
; i
++)
2825 register rtx head
, jump
;
2827 fprintf (file
, "\nBasic block %d: first insn %d, last %d.\n",
2829 INSN_UID (basic_block_head
[i
]),
2830 INSN_UID (basic_block_end
[i
]));
2831 /* The control flow graph's storage is freed
2832 now when flow_analysis returns.
2833 Don't try to print it if it is gone. */
2834 if (basic_block_drops_in
)
2836 fprintf (file
, "Reached from blocks: ");
2837 head
= basic_block_head
[i
];
2838 if (GET_CODE (head
) == CODE_LABEL
)
2839 for (jump
= LABEL_REFS (head
);
2841 jump
= LABEL_NEXTREF (jump
))
2843 register int from_block
= BLOCK_NUM (CONTAINING_INSN (jump
));
2844 fprintf (file
, " %d", from_block
);
2846 if (basic_block_drops_in
[i
])
2847 fprintf (file
, " previous");
2849 fprintf (file
, "\nRegisters live at start:");
2850 for (regno
= 0; regno
< max_regno
; regno
++)
2851 if (REGNO_REG_SET_P (basic_block_live_at_start
[i
], regno
))
2852 fprintf (file
, " %d", regno
);
2853 fprintf (file
, "\n");
2855 fprintf (file
, "\n");
2859 /* Like print_rtl, but also print out live information for the start of each
2863 print_rtl_with_bb (outf
, rtx_first
)
2867 register rtx tmp_rtx
;
2870 fprintf (outf
, "(nil)\n");
2875 enum bb_state
{ NOT_IN_BB
, IN_ONE_BB
, IN_MULTIPLE_BB
};
2876 int max_uid
= get_max_uid ();
2877 int *start
= (int *) alloca (max_uid
* sizeof (int));
2878 int *end
= (int *) alloca (max_uid
* sizeof (int));
2879 char *in_bb_p
= (char *) alloca (max_uid
* sizeof (enum bb_state
));
2881 for (i
= 0; i
< max_uid
; i
++)
2883 start
[i
] = end
[i
] = -1;
2884 in_bb_p
[i
] = NOT_IN_BB
;
2887 for (i
= n_basic_blocks
-1; i
>= 0; i
--)
2890 start
[INSN_UID (basic_block_head
[i
])] = i
;
2891 end
[INSN_UID (basic_block_end
[i
])] = i
;
2892 for (x
= basic_block_head
[i
]; x
!= NULL_RTX
; x
= NEXT_INSN (x
))
2894 in_bb_p
[ INSN_UID(x
)]
2895 = (in_bb_p
[ INSN_UID(x
)] == NOT_IN_BB
)
2896 ? IN_ONE_BB
: IN_MULTIPLE_BB
;
2897 if (x
== basic_block_end
[i
])
2902 for (tmp_rtx
= rtx_first
; NULL
!= tmp_rtx
; tmp_rtx
= NEXT_INSN (tmp_rtx
))
2904 if ((bb
= start
[INSN_UID (tmp_rtx
)]) >= 0)
2908 if (PREV_INSN (tmp_rtx
) != 0
2909 && end
[INSN_UID (PREV_INSN (tmp_rtx
))] >= 0)
2910 fprintf (outf
, " start");
2912 fprintf (outf
, ";; Start");
2914 fprintf (outf
, " of basic block %d.\n;; Registers live:", bb
);
2916 EXECUTE_IF_SET_IN_REG_SET (basic_block_live_at_start
[bb
], 0, i
,
2920 fprintf (outf
, "\n;;\t");
2924 fprintf (outf
, " %d", i
);
2925 pos
+= (i
>= 100 ? 4 : 3);
2926 if (i
< FIRST_PSEUDO_REGISTER
)
2928 fprintf (outf
, " [%s]",
2930 pos
+= (strlen (reg_names
[i
])
2938 if (in_bb_p
[ INSN_UID(tmp_rtx
)] == NOT_IN_BB
2939 && GET_CODE (tmp_rtx
) != NOTE
2940 && GET_CODE (tmp_rtx
) != BARRIER
)
2941 fprintf (outf
, ";; Insn is not within a basic block\n");
2942 else if (in_bb_p
[ INSN_UID(tmp_rtx
)] == IN_MULTIPLE_BB
)
2943 fprintf (outf
, ";; Insn is in multiple basic blocks\n");
2945 print_rtl_single (outf
, tmp_rtx
);
2948 if ((bb
= end
[INSN_UID (tmp_rtx
)]) >= 0)
2950 fprintf (outf
, "\n;; End of basic block %d", bb
);
2951 if (NEXT_INSN (tmp_rtx
) != 0
2952 && start
[INSN_UID (NEXT_INSN (tmp_rtx
))] >= 0)
2953 fprintf (outf
, ";");
2955 fprintf (outf
, ".\n");