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c7a0240a | 1 | /* Combine stack adjustments. |
6fb5fa3c | 2 | Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, |
efc0b2bd | 3 | 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 |
6fb5fa3c | 4 | Free Software Foundation, Inc. |
c7a0240a SB |
5 | |
6 | This file is part of GCC. | |
7 | ||
8 | GCC is free software; you can redistribute it and/or modify it under | |
9 | the terms of the GNU General Public License as published by the Free | |
9dcd6f09 | 10 | Software Foundation; either version 3, or (at your option) any later |
c7a0240a SB |
11 | version. |
12 | ||
13 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
14 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
16 | for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
9dcd6f09 NC |
19 | along with GCC; see the file COPYING3. If not see |
20 | <http://www.gnu.org/licenses/>. */ | |
c7a0240a SB |
21 | |
22 | /* Track stack adjustments and stack memory references. Attempt to | |
23 | reduce the number of stack adjustments by back-propagating across | |
24 | the memory references. | |
25 | ||
26 | This is intended primarily for use with targets that do not define | |
27 | ACCUMULATE_OUTGOING_ARGS. It is of significantly more value to | |
28 | targets that define PREFERRED_STACK_BOUNDARY more aligned than | |
29 | STACK_BOUNDARY (e.g. x86), or if not all registers can be pushed | |
30 | (e.g. x86 fp regs) which would ordinarily have to be implemented | |
31 | as a sub/mov pair due to restrictions in calls.c. | |
32 | ||
33 | Propagation stops when any of the insns that need adjusting are | |
34 | (a) no longer valid because we've exceeded their range, (b) a | |
35 | non-trivial push instruction, or (c) a call instruction. | |
36 | ||
37 | Restriction B is based on the assumption that push instructions | |
38 | are smaller or faster. If a port really wants to remove all | |
39 | pushes, it should have defined ACCUMULATE_OUTGOING_ARGS. The | |
40 | one exception that is made is for an add immediately followed | |
41 | by a push. */ | |
42 | ||
43 | #include "config.h" | |
44 | #include "system.h" | |
45 | #include "coretypes.h" | |
46 | #include "tm.h" | |
47 | #include "rtl.h" | |
48 | #include "tm_p.h" | |
49 | #include "insn-config.h" | |
50 | #include "recog.h" | |
51 | #include "output.h" | |
52 | #include "regs.h" | |
53 | #include "hard-reg-set.h" | |
54 | #include "flags.h" | |
55 | #include "function.h" | |
56 | #include "expr.h" | |
57 | #include "basic-block.h" | |
6fb5fa3c | 58 | #include "df.h" |
c7a0240a SB |
59 | #include "except.h" |
60 | #include "toplev.h" | |
61 | #include "reload.h" | |
62 | #include "timevar.h" | |
63 | #include "tree-pass.h" | |
64 | ||
65 | \f | |
66 | /* Turn STACK_GROWS_DOWNWARD into a boolean. */ | |
67 | #ifdef STACK_GROWS_DOWNWARD | |
68 | #undef STACK_GROWS_DOWNWARD | |
69 | #define STACK_GROWS_DOWNWARD 1 | |
70 | #else | |
71 | #define STACK_GROWS_DOWNWARD 0 | |
72 | #endif | |
73 | ||
90588a10 JJ |
74 | /* This structure records two kinds of stack references between stack |
75 | adjusting instructions: stack references in memory addresses for | |
76 | regular insns and all stack references for debug insns. */ | |
c7a0240a | 77 | |
90588a10 | 78 | struct csa_reflist |
c7a0240a SB |
79 | { |
80 | HOST_WIDE_INT sp_offset; | |
90588a10 JJ |
81 | rtx insn, *ref; |
82 | struct csa_reflist *next; | |
c7a0240a SB |
83 | }; |
84 | ||
85 | static int stack_memref_p (rtx); | |
86 | static rtx single_set_for_csa (rtx); | |
90588a10 JJ |
87 | static void free_csa_reflist (struct csa_reflist *); |
88 | static struct csa_reflist *record_one_stack_ref (rtx, rtx *, | |
89 | struct csa_reflist *); | |
90 | static int try_apply_stack_adjustment (rtx, struct csa_reflist *, | |
c7a0240a SB |
91 | HOST_WIDE_INT, HOST_WIDE_INT); |
92 | static void combine_stack_adjustments_for_block (basic_block); | |
90588a10 | 93 | static int record_stack_refs (rtx *, void *); |
c7a0240a SB |
94 | |
95 | ||
96 | /* Main entry point for stack adjustment combination. */ | |
97 | ||
98 | static void | |
99 | combine_stack_adjustments (void) | |
100 | { | |
101 | basic_block bb; | |
102 | ||
103 | FOR_EACH_BB (bb) | |
104 | combine_stack_adjustments_for_block (bb); | |
105 | } | |
106 | ||
107 | /* Recognize a MEM of the form (sp) or (plus sp const). */ | |
108 | ||
109 | static int | |
110 | stack_memref_p (rtx x) | |
111 | { | |
112 | if (!MEM_P (x)) | |
113 | return 0; | |
114 | x = XEXP (x, 0); | |
115 | ||
116 | if (x == stack_pointer_rtx) | |
117 | return 1; | |
118 | if (GET_CODE (x) == PLUS | |
119 | && XEXP (x, 0) == stack_pointer_rtx | |
481683e1 | 120 | && CONST_INT_P (XEXP (x, 1))) |
c7a0240a SB |
121 | return 1; |
122 | ||
123 | return 0; | |
124 | } | |
125 | ||
126 | /* Recognize either normal single_set or the hack in i386.md for | |
127 | tying fp and sp adjustments. */ | |
128 | ||
129 | static rtx | |
130 | single_set_for_csa (rtx insn) | |
131 | { | |
132 | int i; | |
133 | rtx tmp = single_set (insn); | |
134 | if (tmp) | |
135 | return tmp; | |
136 | ||
137 | if (!NONJUMP_INSN_P (insn) | |
138 | || GET_CODE (PATTERN (insn)) != PARALLEL) | |
139 | return NULL_RTX; | |
140 | ||
141 | tmp = PATTERN (insn); | |
142 | if (GET_CODE (XVECEXP (tmp, 0, 0)) != SET) | |
143 | return NULL_RTX; | |
144 | ||
145 | for (i = 1; i < XVECLEN (tmp, 0); ++i) | |
146 | { | |
48c54229 | 147 | rtx this_rtx = XVECEXP (tmp, 0, i); |
c7a0240a SB |
148 | |
149 | /* The special case is allowing a no-op set. */ | |
48c54229 KG |
150 | if (GET_CODE (this_rtx) == SET |
151 | && SET_SRC (this_rtx) == SET_DEST (this_rtx)) | |
c7a0240a | 152 | ; |
48c54229 KG |
153 | else if (GET_CODE (this_rtx) != CLOBBER |
154 | && GET_CODE (this_rtx) != USE) | |
c7a0240a SB |
155 | return NULL_RTX; |
156 | } | |
157 | ||
158 | return XVECEXP (tmp, 0, 0); | |
159 | } | |
160 | ||
90588a10 | 161 | /* Free the list of csa_reflist nodes. */ |
c7a0240a SB |
162 | |
163 | static void | |
90588a10 | 164 | free_csa_reflist (struct csa_reflist *reflist) |
c7a0240a | 165 | { |
90588a10 JJ |
166 | struct csa_reflist *next; |
167 | for (; reflist ; reflist = next) | |
c7a0240a | 168 | { |
90588a10 JJ |
169 | next = reflist->next; |
170 | free (reflist); | |
c7a0240a SB |
171 | } |
172 | } | |
173 | ||
90588a10 JJ |
174 | /* Create a new csa_reflist node from the given stack reference. |
175 | It is already known that the reference is either a MEM satisfying the | |
176 | predicate stack_memref_p or a REG representing the stack pointer. */ | |
c7a0240a | 177 | |
90588a10 JJ |
178 | static struct csa_reflist * |
179 | record_one_stack_ref (rtx insn, rtx *ref, struct csa_reflist *next_reflist) | |
c7a0240a | 180 | { |
90588a10 | 181 | struct csa_reflist *ml; |
c7a0240a | 182 | |
90588a10 | 183 | ml = XNEW (struct csa_reflist); |
c7a0240a | 184 | |
90588a10 | 185 | if (REG_P (*ref) || XEXP (*ref, 0) == stack_pointer_rtx) |
c7a0240a SB |
186 | ml->sp_offset = 0; |
187 | else | |
90588a10 | 188 | ml->sp_offset = INTVAL (XEXP (XEXP (*ref, 0), 1)); |
c7a0240a SB |
189 | |
190 | ml->insn = insn; | |
90588a10 JJ |
191 | ml->ref = ref; |
192 | ml->next = next_reflist; | |
c7a0240a SB |
193 | |
194 | return ml; | |
195 | } | |
196 | ||
197 | /* Attempt to apply ADJUST to the stack adjusting insn INSN, as well | |
90588a10 JJ |
198 | as each of the memories and stack references in REFLIST. Return true |
199 | on success. */ | |
c7a0240a SB |
200 | |
201 | static int | |
90588a10 JJ |
202 | try_apply_stack_adjustment (rtx insn, struct csa_reflist *reflist, |
203 | HOST_WIDE_INT new_adjust, HOST_WIDE_INT delta) | |
c7a0240a | 204 | { |
90588a10 | 205 | struct csa_reflist *ml; |
c7a0240a SB |
206 | rtx set; |
207 | ||
208 | set = single_set_for_csa (insn); | |
1362aa31 EB |
209 | if (MEM_P (SET_DEST (set))) |
210 | validate_change (insn, &SET_DEST (set), | |
211 | replace_equiv_address (SET_DEST (set), stack_pointer_rtx), | |
212 | 1); | |
213 | else | |
214 | validate_change (insn, &XEXP (SET_SRC (set), 1), GEN_INT (new_adjust), 1); | |
c7a0240a | 215 | |
90588a10 JJ |
216 | for (ml = reflist; ml ; ml = ml->next) |
217 | { | |
218 | rtx new_addr = plus_constant (stack_pointer_rtx, ml->sp_offset - delta); | |
219 | rtx new_val; | |
220 | ||
221 | if (MEM_P (*ml->ref)) | |
222 | new_val = replace_equiv_address_nv (*ml->ref, new_addr); | |
223 | else if (GET_MODE (*ml->ref) == GET_MODE (stack_pointer_rtx)) | |
224 | new_val = new_addr; | |
225 | else | |
226 | new_val = lowpart_subreg (GET_MODE (*ml->ref), new_addr, | |
227 | GET_MODE (new_addr)); | |
228 | validate_change (ml->insn, ml->ref, new_val, 1); | |
229 | } | |
c7a0240a SB |
230 | |
231 | if (apply_change_group ()) | |
232 | { | |
90588a10 JJ |
233 | /* Succeeded. Update our knowledge of the stack references. */ |
234 | for (ml = reflist; ml ; ml = ml->next) | |
c7a0240a SB |
235 | ml->sp_offset -= delta; |
236 | ||
237 | return 1; | |
238 | } | |
239 | else | |
240 | return 0; | |
241 | } | |
242 | ||
90588a10 JJ |
243 | /* Called via for_each_rtx and used to record all stack memory and other |
244 | references in the insn and discard all other stack pointer references. */ | |
245 | struct record_stack_refs_data | |
c7a0240a SB |
246 | { |
247 | rtx insn; | |
90588a10 | 248 | struct csa_reflist *reflist; |
c7a0240a SB |
249 | }; |
250 | ||
251 | static int | |
90588a10 | 252 | record_stack_refs (rtx *xp, void *data) |
c7a0240a SB |
253 | { |
254 | rtx x = *xp; | |
90588a10 JJ |
255 | struct record_stack_refs_data *d = |
256 | (struct record_stack_refs_data *) data; | |
c7a0240a SB |
257 | if (!x) |
258 | return 0; | |
259 | switch (GET_CODE (x)) | |
260 | { | |
261 | case MEM: | |
262 | if (!reg_mentioned_p (stack_pointer_rtx, x)) | |
263 | return -1; | |
264 | /* We are not able to handle correctly all possible memrefs containing | |
265 | stack pointer, so this check is necessary. */ | |
266 | if (stack_memref_p (x)) | |
267 | { | |
90588a10 | 268 | d->reflist = record_one_stack_ref (d->insn, xp, d->reflist); |
c7a0240a SB |
269 | return -1; |
270 | } | |
90588a10 JJ |
271 | /* Try harder for DEBUG_INSNs, handle e.g. (mem (mem (sp + 16) + 4). */ |
272 | return !DEBUG_INSN_P (d->insn); | |
c7a0240a SB |
273 | case REG: |
274 | /* ??? We want be able to handle non-memory stack pointer | |
275 | references later. For now just discard all insns referring to | |
276 | stack pointer outside mem expressions. We would probably | |
277 | want to teach validate_replace to simplify expressions first. | |
278 | ||
279 | We can't just compare with STACK_POINTER_RTX because the | |
280 | reference to the stack pointer might be in some other mode. | |
281 | In particular, an explicit clobber in an asm statement will | |
90588a10 JJ |
282 | result in a QImode clobber. |
283 | ||
284 | In DEBUG_INSNs, we want to replace all occurrences, otherwise | |
285 | they will cause -fcompare-debug failures. */ | |
c7a0240a | 286 | if (REGNO (x) == STACK_POINTER_REGNUM) |
90588a10 JJ |
287 | { |
288 | if (!DEBUG_INSN_P (d->insn)) | |
289 | return 1; | |
290 | d->reflist = record_one_stack_ref (d->insn, xp, d->reflist); | |
291 | return -1; | |
292 | } | |
c7a0240a SB |
293 | break; |
294 | default: | |
295 | break; | |
296 | } | |
297 | return 0; | |
298 | } | |
299 | ||
a182fb6b JJ |
300 | /* Adjust or create REG_FRAME_RELATED_EXPR note when merging a stack |
301 | adjustment into a frame related insn. */ | |
302 | ||
303 | static void | |
304 | adjust_frame_related_expr (rtx last_sp_set, rtx insn, | |
305 | HOST_WIDE_INT this_adjust) | |
306 | { | |
307 | rtx note = find_reg_note (last_sp_set, REG_FRAME_RELATED_EXPR, NULL_RTX); | |
308 | rtx new_expr = NULL_RTX; | |
309 | ||
310 | if (note == NULL_RTX && RTX_FRAME_RELATED_P (insn)) | |
311 | return; | |
312 | ||
313 | if (note | |
314 | && GET_CODE (XEXP (note, 0)) == SEQUENCE | |
315 | && XVECLEN (XEXP (note, 0), 0) >= 2) | |
316 | { | |
317 | rtx expr = XEXP (note, 0); | |
318 | rtx last = XVECEXP (expr, 0, XVECLEN (expr, 0) - 1); | |
319 | int i; | |
320 | ||
321 | if (GET_CODE (last) == SET | |
322 | && RTX_FRAME_RELATED_P (last) == RTX_FRAME_RELATED_P (insn) | |
323 | && SET_DEST (last) == stack_pointer_rtx | |
324 | && GET_CODE (SET_SRC (last)) == PLUS | |
325 | && XEXP (SET_SRC (last), 0) == stack_pointer_rtx | |
481683e1 | 326 | && CONST_INT_P (XEXP (SET_SRC (last), 1))) |
a182fb6b JJ |
327 | { |
328 | XEXP (SET_SRC (last), 1) | |
329 | = GEN_INT (INTVAL (XEXP (SET_SRC (last), 1)) + this_adjust); | |
330 | return; | |
331 | } | |
332 | ||
333 | new_expr = gen_rtx_SEQUENCE (VOIDmode, | |
334 | rtvec_alloc (XVECLEN (expr, 0) + 1)); | |
335 | for (i = 0; i < XVECLEN (expr, 0); i++) | |
336 | XVECEXP (new_expr, 0, i) = XVECEXP (expr, 0, i); | |
337 | } | |
338 | else | |
339 | { | |
340 | new_expr = gen_rtx_SEQUENCE (VOIDmode, rtvec_alloc (2)); | |
341 | if (note) | |
342 | XVECEXP (new_expr, 0, 0) = XEXP (note, 0); | |
343 | else | |
344 | { | |
345 | rtx expr = copy_rtx (single_set_for_csa (last_sp_set)); | |
346 | ||
347 | XEXP (SET_SRC (expr), 1) | |
348 | = GEN_INT (INTVAL (XEXP (SET_SRC (expr), 1)) - this_adjust); | |
349 | RTX_FRAME_RELATED_P (expr) = 1; | |
350 | XVECEXP (new_expr, 0, 0) = expr; | |
351 | } | |
352 | } | |
353 | ||
354 | XVECEXP (new_expr, 0, XVECLEN (new_expr, 0) - 1) | |
355 | = copy_rtx (single_set_for_csa (insn)); | |
356 | RTX_FRAME_RELATED_P (XVECEXP (new_expr, 0, XVECLEN (new_expr, 0) - 1)) | |
357 | = RTX_FRAME_RELATED_P (insn); | |
358 | if (note) | |
359 | XEXP (note, 0) = new_expr; | |
360 | else | |
efc0b2bd | 361 | add_reg_note (last_sp_set, REG_FRAME_RELATED_EXPR, new_expr); |
a182fb6b JJ |
362 | } |
363 | ||
c7a0240a SB |
364 | /* Subroutine of combine_stack_adjustments, called for each basic block. */ |
365 | ||
366 | static void | |
367 | combine_stack_adjustments_for_block (basic_block bb) | |
368 | { | |
369 | HOST_WIDE_INT last_sp_adjust = 0; | |
370 | rtx last_sp_set = NULL_RTX; | |
90588a10 | 371 | struct csa_reflist *reflist = NULL; |
c7a0240a | 372 | rtx insn, next, set; |
90588a10 | 373 | struct record_stack_refs_data data; |
c7a0240a SB |
374 | bool end_of_block = false; |
375 | ||
376 | for (insn = BB_HEAD (bb); !end_of_block ; insn = next) | |
377 | { | |
378 | end_of_block = insn == BB_END (bb); | |
379 | next = NEXT_INSN (insn); | |
380 | ||
381 | if (! INSN_P (insn)) | |
382 | continue; | |
383 | ||
384 | set = single_set_for_csa (insn); | |
385 | if (set) | |
386 | { | |
387 | rtx dest = SET_DEST (set); | |
388 | rtx src = SET_SRC (set); | |
389 | ||
390 | /* Find constant additions to the stack pointer. */ | |
391 | if (dest == stack_pointer_rtx | |
392 | && GET_CODE (src) == PLUS | |
393 | && XEXP (src, 0) == stack_pointer_rtx | |
481683e1 | 394 | && CONST_INT_P (XEXP (src, 1))) |
c7a0240a SB |
395 | { |
396 | HOST_WIDE_INT this_adjust = INTVAL (XEXP (src, 1)); | |
397 | ||
398 | /* If we've not seen an adjustment previously, record | |
399 | it now and continue. */ | |
400 | if (! last_sp_set) | |
401 | { | |
402 | last_sp_set = insn; | |
403 | last_sp_adjust = this_adjust; | |
404 | continue; | |
405 | } | |
406 | ||
90588a10 | 407 | /* If not all recorded refs can be adjusted, or the |
c7a0240a SB |
408 | adjustment is now too large for a constant addition, |
409 | we cannot merge the two stack adjustments. | |
410 | ||
411 | Also we need to be careful to not move stack pointer | |
412 | such that we create stack accesses outside the allocated | |
413 | area. We can combine an allocation into the first insn, | |
414 | or a deallocation into the second insn. We can not | |
415 | combine an allocation followed by a deallocation. | |
416 | ||
417 | The only somewhat frequent occurrence of the later is when | |
418 | a function allocates a stack frame but does not use it. | |
419 | For this case, we would need to analyze rtl stream to be | |
420 | sure that allocated area is really unused. This means not | |
421 | only checking the memory references, but also all registers | |
422 | or global memory references possibly containing a stack | |
423 | frame address. | |
424 | ||
425 | Perhaps the best way to address this problem is to teach | |
426 | gcc not to allocate stack for objects never used. */ | |
427 | ||
428 | /* Combine an allocation into the first instruction. */ | |
429 | if (STACK_GROWS_DOWNWARD ? this_adjust <= 0 : this_adjust >= 0) | |
430 | { | |
90588a10 | 431 | if (try_apply_stack_adjustment (last_sp_set, reflist, |
c7a0240a SB |
432 | last_sp_adjust + this_adjust, |
433 | this_adjust)) | |
434 | { | |
a182fb6b JJ |
435 | if (RTX_FRAME_RELATED_P (last_sp_set)) |
436 | adjust_frame_related_expr (last_sp_set, insn, | |
437 | this_adjust); | |
c7a0240a SB |
438 | /* It worked! */ |
439 | delete_insn (insn); | |
440 | last_sp_adjust += this_adjust; | |
441 | continue; | |
442 | } | |
443 | } | |
444 | ||
445 | /* Otherwise we have a deallocation. Do not combine with | |
446 | a previous allocation. Combine into the second insn. */ | |
447 | else if (STACK_GROWS_DOWNWARD | |
448 | ? last_sp_adjust >= 0 : last_sp_adjust <= 0) | |
449 | { | |
90588a10 | 450 | if (try_apply_stack_adjustment (insn, reflist, |
c7a0240a SB |
451 | last_sp_adjust + this_adjust, |
452 | -last_sp_adjust)) | |
453 | { | |
454 | /* It worked! */ | |
455 | delete_insn (last_sp_set); | |
456 | last_sp_set = insn; | |
457 | last_sp_adjust += this_adjust; | |
90588a10 JJ |
458 | free_csa_reflist (reflist); |
459 | reflist = NULL; | |
c7a0240a SB |
460 | continue; |
461 | } | |
462 | } | |
463 | ||
464 | /* Combination failed. Restart processing from here. If | |
465 | deallocation+allocation conspired to cancel, we can | |
466 | delete the old deallocation insn. */ | |
467 | if (last_sp_set && last_sp_adjust == 0) | |
a182fb6b | 468 | delete_insn (last_sp_set); |
90588a10 JJ |
469 | free_csa_reflist (reflist); |
470 | reflist = NULL; | |
c7a0240a SB |
471 | last_sp_set = insn; |
472 | last_sp_adjust = this_adjust; | |
473 | continue; | |
474 | } | |
475 | ||
1362aa31 EB |
476 | /* Find a store with pre-(dec|inc)rement or pre-modify of exactly |
477 | the previous adjustment and turn it into a simple store. This | |
478 | is equivalent to anticipating the stack adjustment so this must | |
479 | be an allocation. */ | |
480 | if (MEM_P (dest) | |
481 | && ((STACK_GROWS_DOWNWARD | |
482 | ? (GET_CODE (XEXP (dest, 0)) == PRE_DEC | |
483 | && last_sp_adjust | |
484 | == (HOST_WIDE_INT) GET_MODE_SIZE (GET_MODE (dest))) | |
485 | : (GET_CODE (XEXP (dest, 0)) == PRE_INC | |
486 | && last_sp_adjust | |
487 | == -(HOST_WIDE_INT) GET_MODE_SIZE (GET_MODE (dest)))) | |
488 | || ((STACK_GROWS_DOWNWARD | |
489 | ? last_sp_adjust >= 0 : last_sp_adjust <= 0) | |
490 | && GET_CODE (XEXP (dest, 0)) == PRE_MODIFY | |
c7a0240a | 491 | && GET_CODE (XEXP (XEXP (dest, 0), 1)) == PLUS |
1362aa31 EB |
492 | && XEXP (XEXP (XEXP (dest, 0), 1), 0) |
493 | == stack_pointer_rtx | |
494 | && GET_CODE (XEXP (XEXP (XEXP (dest, 0), 1), 1)) | |
495 | == CONST_INT | |
496 | && INTVAL (XEXP (XEXP (XEXP (dest, 0), 1), 1)) | |
497 | == -last_sp_adjust)) | |
c7a0240a | 498 | && XEXP (XEXP (dest, 0), 0) == stack_pointer_rtx |
1362aa31 | 499 | && !reg_mentioned_p (stack_pointer_rtx, src) |
c7a0240a | 500 | && memory_address_p (GET_MODE (dest), stack_pointer_rtx) |
1362aa31 EB |
501 | && try_apply_stack_adjustment (insn, reflist, 0, |
502 | -last_sp_adjust)) | |
c7a0240a SB |
503 | { |
504 | delete_insn (last_sp_set); | |
90588a10 JJ |
505 | free_csa_reflist (reflist); |
506 | reflist = NULL; | |
c7a0240a SB |
507 | last_sp_set = NULL_RTX; |
508 | last_sp_adjust = 0; | |
509 | continue; | |
510 | } | |
511 | } | |
512 | ||
513 | data.insn = insn; | |
90588a10 | 514 | data.reflist = reflist; |
c7a0240a | 515 | if (!CALL_P (insn) && last_sp_set |
90588a10 | 516 | && !for_each_rtx (&PATTERN (insn), record_stack_refs, &data)) |
c7a0240a | 517 | { |
90588a10 | 518 | reflist = data.reflist; |
c7a0240a SB |
519 | continue; |
520 | } | |
90588a10 | 521 | reflist = data.reflist; |
c7a0240a SB |
522 | |
523 | /* Otherwise, we were not able to process the instruction. | |
524 | Do not continue collecting data across such a one. */ | |
525 | if (last_sp_set | |
526 | && (CALL_P (insn) | |
527 | || reg_mentioned_p (stack_pointer_rtx, PATTERN (insn)))) | |
528 | { | |
529 | if (last_sp_set && last_sp_adjust == 0) | |
530 | delete_insn (last_sp_set); | |
90588a10 JJ |
531 | free_csa_reflist (reflist); |
532 | reflist = NULL; | |
c7a0240a SB |
533 | last_sp_set = NULL_RTX; |
534 | last_sp_adjust = 0; | |
535 | } | |
536 | } | |
537 | ||
538 | if (last_sp_set && last_sp_adjust == 0) | |
539 | delete_insn (last_sp_set); | |
540 | ||
90588a10 JJ |
541 | if (reflist) |
542 | free_csa_reflist (reflist); | |
c7a0240a SB |
543 | } |
544 | \f | |
545 | ||
546 | static bool | |
547 | gate_handle_stack_adjustments (void) | |
548 | { | |
ccaeeafe | 549 | return flag_combine_stack_adjustments; |
c7a0240a SB |
550 | } |
551 | ||
552 | static unsigned int | |
553 | rest_of_handle_stack_adjustments (void) | |
554 | { | |
6fb5fa3c | 555 | cleanup_cfg (flag_crossjumping ? CLEANUP_CROSSJUMP : 0); |
c7a0240a SB |
556 | |
557 | /* This is kind of a heuristic. We need to run combine_stack_adjustments | |
079e7538 | 558 | even for machines with possibly nonzero TARGET_RETURN_POPS_ARGS |
c7a0240a SB |
559 | and ACCUMULATE_OUTGOING_ARGS. We expect that only ports having |
560 | push instructions will have popping returns. */ | |
561 | #ifndef PUSH_ROUNDING | |
562 | if (!ACCUMULATE_OUTGOING_ARGS) | |
563 | #endif | |
6fb5fa3c DB |
564 | { |
565 | df_note_add_problem (); | |
566 | df_analyze (); | |
567 | combine_stack_adjustments (); | |
568 | } | |
c7a0240a SB |
569 | return 0; |
570 | } | |
571 | ||
8ddbbcae | 572 | struct rtl_opt_pass pass_stack_adjustments = |
c7a0240a | 573 | { |
8ddbbcae JH |
574 | { |
575 | RTL_PASS, | |
c7a0240a SB |
576 | "csa", /* name */ |
577 | gate_handle_stack_adjustments, /* gate */ | |
578 | rest_of_handle_stack_adjustments, /* execute */ | |
579 | NULL, /* sub */ | |
580 | NULL, /* next */ | |
581 | 0, /* static_pass_number */ | |
756b65f5 | 582 | TV_COMBINE_STACK_ADJUST, /* tv_id */ |
c7a0240a SB |
583 | 0, /* properties_required */ |
584 | 0, /* properties_provided */ | |
585 | 0, /* properties_destroyed */ | |
586 | 0, /* todo_flags_start */ | |
a36b8a1e | 587 | TODO_df_finish | TODO_verify_rtl_sharing | |
c7a0240a SB |
588 | TODO_dump_func | |
589 | TODO_ggc_collect, /* todo_flags_finish */ | |
8ddbbcae | 590 | } |
c7a0240a | 591 | }; |