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08df6c0d AO |
1 | /* Infrastructure for tracking user variable locations and values |
2 | throughout compilation. | |
3 | Copyright (C) 2010, 2011, 2012 Free Software Foundation, Inc. | |
4 | Contributed by Alexandre Oliva <aoliva@redhat.com>. | |
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 | |
10 | Software Foundation; either version 3, or (at your option) any later | |
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 | |
19 | along with GCC; see the file COPYING3. If not see | |
20 | <http://www.gnu.org/licenses/>. */ | |
21 | ||
22 | #include "config.h" | |
23 | #include "system.h" | |
24 | #include "coretypes.h" | |
25 | #include "tm.h" | |
26 | #include "rtl.h" | |
27 | #include "valtrack.h" | |
28 | #include "function.h" | |
29 | #include "regs.h" | |
30 | #include "emit-rtl.h" | |
31 | ||
32 | /* Replace auto-increment addressing modes with explicit operations to access | |
33 | the same addresses without modifying the corresponding registers. */ | |
34 | ||
08df6c0d AO |
35 | static rtx |
36 | cleanup_auto_inc_dec (rtx src, enum machine_mode mem_mode ATTRIBUTE_UNUSED) | |
37 | { | |
38 | rtx x = src; | |
375e3d07 | 39 | #ifdef AUTO_INC_DEC |
08df6c0d AO |
40 | const RTX_CODE code = GET_CODE (x); |
41 | int i; | |
42 | const char *fmt; | |
43 | ||
44 | switch (code) | |
45 | { | |
46 | case REG: | |
d8116890 | 47 | CASE_CONST_ANY: |
08df6c0d AO |
48 | case SYMBOL_REF: |
49 | case CODE_LABEL: | |
50 | case PC: | |
51 | case CC0: | |
52 | case SCRATCH: | |
53 | /* SCRATCH must be shared because they represent distinct values. */ | |
54 | return x; | |
55 | case CLOBBER: | |
56 | if (REG_P (XEXP (x, 0)) && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER) | |
57 | return x; | |
58 | break; | |
59 | ||
60 | case CONST: | |
61 | if (shared_const_p (x)) | |
62 | return x; | |
63 | break; | |
64 | ||
65 | case MEM: | |
66 | mem_mode = GET_MODE (x); | |
67 | break; | |
68 | ||
69 | case PRE_INC: | |
70 | case PRE_DEC: | |
71 | gcc_assert (mem_mode != VOIDmode && mem_mode != BLKmode); | |
72 | return gen_rtx_PLUS (GET_MODE (x), | |
73 | cleanup_auto_inc_dec (XEXP (x, 0), mem_mode), | |
74 | GEN_INT (code == PRE_INC | |
75 | ? GET_MODE_SIZE (mem_mode) | |
76 | : -GET_MODE_SIZE (mem_mode))); | |
77 | ||
78 | case POST_INC: | |
79 | case POST_DEC: | |
80 | case PRE_MODIFY: | |
81 | case POST_MODIFY: | |
82 | return cleanup_auto_inc_dec (code == PRE_MODIFY | |
83 | ? XEXP (x, 1) : XEXP (x, 0), | |
84 | mem_mode); | |
85 | ||
86 | default: | |
87 | break; | |
88 | } | |
89 | ||
90 | /* Copy the various flags, fields, and other information. We assume | |
91 | that all fields need copying, and then clear the fields that should | |
92 | not be copied. That is the sensible default behavior, and forces | |
93 | us to explicitly document why we are *not* copying a flag. */ | |
94 | x = shallow_copy_rtx (x); | |
95 | ||
96 | /* We do not copy the USED flag, which is used as a mark bit during | |
97 | walks over the RTL. */ | |
98 | RTX_FLAG (x, used) = 0; | |
99 | ||
100 | /* We do not copy FRAME_RELATED for INSNs. */ | |
101 | if (INSN_P (x)) | |
102 | RTX_FLAG (x, frame_related) = 0; | |
103 | ||
104 | fmt = GET_RTX_FORMAT (code); | |
105 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
106 | if (fmt[i] == 'e') | |
107 | XEXP (x, i) = cleanup_auto_inc_dec (XEXP (x, i), mem_mode); | |
108 | else if (fmt[i] == 'E' || fmt[i] == 'V') | |
109 | { | |
110 | int j; | |
111 | XVEC (x, i) = rtvec_alloc (XVECLEN (x, i)); | |
112 | for (j = 0; j < XVECLEN (x, i); j++) | |
113 | XVECEXP (x, i, j) | |
114 | = cleanup_auto_inc_dec (XVECEXP (src, i, j), mem_mode); | |
115 | } | |
116 | ||
375e3d07 AO |
117 | #else /* !AUTO_INC_DEC */ |
118 | x = copy_rtx (x); | |
119 | #endif /* !AUTO_INC_DEC */ | |
120 | ||
08df6c0d AO |
121 | return x; |
122 | } | |
08df6c0d AO |
123 | |
124 | /* Auxiliary data structure for propagate_for_debug_stmt. */ | |
125 | ||
126 | struct rtx_subst_pair | |
127 | { | |
128 | rtx to; | |
129 | bool adjusted; | |
130 | }; | |
131 | ||
132 | /* DATA points to an rtx_subst_pair. Return the value that should be | |
133 | substituted. */ | |
134 | ||
135 | static rtx | |
136 | propagate_for_debug_subst (rtx from, const_rtx old_rtx, void *data) | |
137 | { | |
138 | struct rtx_subst_pair *pair = (struct rtx_subst_pair *)data; | |
139 | ||
140 | if (!rtx_equal_p (from, old_rtx)) | |
141 | return NULL_RTX; | |
142 | if (!pair->adjusted) | |
143 | { | |
144 | pair->adjusted = true; | |
08df6c0d | 145 | pair->to = cleanup_auto_inc_dec (pair->to, VOIDmode); |
08df6c0d AO |
146 | pair->to = make_compound_operation (pair->to, SET); |
147 | return pair->to; | |
148 | } | |
149 | return copy_rtx (pair->to); | |
150 | } | |
151 | ||
152 | /* Replace all the occurrences of DEST with SRC in DEBUG_INSNs between INSN | |
153 | and LAST, not including INSN, but including LAST. Also stop at the end | |
154 | of THIS_BASIC_BLOCK. */ | |
155 | ||
156 | void | |
157 | propagate_for_debug (rtx insn, rtx last, rtx dest, rtx src, | |
158 | basic_block this_basic_block) | |
159 | { | |
160 | rtx next, loc, end = NEXT_INSN (BB_END (this_basic_block)); | |
161 | ||
162 | struct rtx_subst_pair p; | |
163 | p.to = src; | |
164 | p.adjusted = false; | |
165 | ||
166 | next = NEXT_INSN (insn); | |
167 | last = NEXT_INSN (last); | |
168 | while (next != last && next != end) | |
169 | { | |
170 | insn = next; | |
171 | next = NEXT_INSN (insn); | |
172 | if (DEBUG_INSN_P (insn)) | |
173 | { | |
174 | loc = simplify_replace_fn_rtx (INSN_VAR_LOCATION_LOC (insn), | |
175 | dest, propagate_for_debug_subst, &p); | |
176 | if (loc == INSN_VAR_LOCATION_LOC (insn)) | |
177 | continue; | |
178 | INSN_VAR_LOCATION_LOC (insn) = loc; | |
179 | df_insn_rescan (insn); | |
180 | } | |
181 | } | |
182 | } | |
183 | ||
184 | /* Initialize DEBUG to an empty list, and clear USED, if given. */ | |
e9f950ba AO |
185 | |
186 | void | |
187 | dead_debug_global_init (struct dead_debug_global *debug, bitmap used) | |
188 | { | |
189 | debug->used = used; | |
190 | if (used) | |
191 | bitmap_clear (used); | |
192 | } | |
193 | ||
194 | /* Initialize DEBUG to an empty list, and clear USED, if given. Link | |
195 | back to GLOBAL, if given, and bring in used bits from it. */ | |
196 | ||
08df6c0d | 197 | void |
e9f950ba AO |
198 | dead_debug_local_init (struct dead_debug_local *debug, bitmap used, |
199 | struct dead_debug_global *global) | |
08df6c0d | 200 | { |
e9f950ba AO |
201 | if (!used && global && global->used) |
202 | used = BITMAP_ALLOC (NULL); | |
203 | ||
08df6c0d | 204 | debug->head = NULL; |
e9f950ba | 205 | debug->global = global; |
08df6c0d AO |
206 | debug->used = used; |
207 | debug->to_rescan = NULL; | |
e9f950ba | 208 | |
08df6c0d | 209 | if (used) |
e9f950ba AO |
210 | { |
211 | if (global && global->used) | |
212 | bitmap_copy (used, global->used); | |
213 | else | |
214 | bitmap_clear (used); | |
215 | } | |
216 | } | |
217 | ||
218 | /* Locate the entry for REG in GLOBAL->htab. */ | |
219 | ||
220 | static dead_debug_global_entry * | |
221 | dead_debug_global_find (struct dead_debug_global *global, rtx reg) | |
222 | { | |
223 | dead_debug_global_entry temp_entry; | |
224 | temp_entry.reg = reg; | |
225 | ||
226 | dead_debug_global_entry *entry = global->htab.find (&temp_entry); | |
227 | gcc_checking_assert (entry && entry->reg == temp_entry.reg); | |
e9f950ba AO |
228 | |
229 | return entry; | |
230 | } | |
231 | ||
232 | /* Insert an entry mapping REG to DTEMP in GLOBAL->htab. */ | |
233 | ||
0e45ec20 | 234 | static dead_debug_global_entry * |
e9f950ba AO |
235 | dead_debug_global_insert (struct dead_debug_global *global, rtx reg, rtx dtemp) |
236 | { | |
237 | dead_debug_global_entry temp_entry; | |
238 | temp_entry.reg = reg; | |
239 | temp_entry.dtemp = dtemp; | |
240 | ||
241 | if (!global->htab.is_created ()) | |
242 | global->htab.create (31); | |
243 | ||
244 | dead_debug_global_entry **slot = global->htab.find_slot (&temp_entry, INSERT); | |
245 | gcc_checking_assert (!*slot); | |
246 | *slot = XNEW (dead_debug_global_entry); | |
247 | **slot = temp_entry; | |
0e45ec20 | 248 | return *slot; |
e9f950ba AO |
249 | } |
250 | ||
251 | /* If UREGNO, referenced by USE, is a pseudo marked as used in GLOBAL, | |
252 | replace it with with a USE of the debug temp recorded for it, and | |
253 | return TRUE. Otherwise, just return FALSE. | |
254 | ||
255 | If PTO_RESCAN is given, instead of rescanning modified INSNs right | |
256 | away, add their UIDs to the bitmap, allocating one of *PTO_RESCAN | |
257 | is NULL. */ | |
258 | ||
259 | static bool | |
260 | dead_debug_global_replace_temp (struct dead_debug_global *global, | |
261 | df_ref use, unsigned int uregno, | |
262 | bitmap *pto_rescan) | |
263 | { | |
264 | if (!global || uregno < FIRST_PSEUDO_REGISTER | |
265 | || !global->used | |
0e45ec20 AO |
266 | || !REG_P (*DF_REF_REAL_LOC (use)) |
267 | || REGNO (*DF_REF_REAL_LOC (use)) != uregno | |
e9f950ba AO |
268 | || !bitmap_bit_p (global->used, uregno)) |
269 | return false; | |
270 | ||
e9f950ba AO |
271 | dead_debug_global_entry *entry |
272 | = dead_debug_global_find (global, *DF_REF_REAL_LOC (use)); | |
273 | gcc_checking_assert (GET_CODE (entry->reg) == REG | |
274 | && REGNO (entry->reg) == uregno); | |
275 | ||
0e45ec20 AO |
276 | if (!entry->dtemp) |
277 | return true; | |
278 | ||
e9f950ba AO |
279 | *DF_REF_REAL_LOC (use) = entry->dtemp; |
280 | if (!pto_rescan) | |
281 | df_insn_rescan (DF_REF_INSN (use)); | |
282 | else | |
283 | { | |
284 | if (!*pto_rescan) | |
285 | *pto_rescan = BITMAP_ALLOC (NULL); | |
286 | bitmap_set_bit (*pto_rescan, INSN_UID (DF_REF_INSN (use))); | |
287 | } | |
288 | ||
289 | return true; | |
08df6c0d AO |
290 | } |
291 | ||
292 | /* Reset all debug uses in HEAD, and clear DEBUG->to_rescan bits of | |
293 | each reset insn. DEBUG is not otherwise modified. If HEAD is | |
294 | DEBUG->head, DEBUG->head will be set to NULL at the end. | |
295 | Otherwise, entries from DEBUG->head that pertain to reset insns | |
296 | will be removed, and only then rescanned. */ | |
297 | ||
298 | static void | |
e9f950ba AO |
299 | dead_debug_reset_uses (struct dead_debug_local *debug, |
300 | struct dead_debug_use *head) | |
08df6c0d AO |
301 | { |
302 | bool got_head = (debug->head == head); | |
303 | bitmap rescan; | |
304 | struct dead_debug_use **tailp = &debug->head; | |
305 | struct dead_debug_use *cur; | |
306 | bitmap_iterator bi; | |
307 | unsigned int uid; | |
308 | ||
309 | if (got_head) | |
310 | rescan = NULL; | |
311 | else | |
312 | rescan = BITMAP_ALLOC (NULL); | |
313 | ||
314 | while (head) | |
315 | { | |
316 | struct dead_debug_use *next = head->next; | |
317 | rtx insn; | |
318 | ||
319 | insn = DF_REF_INSN (head->use); | |
320 | if (!next || DF_REF_INSN (next->use) != insn) | |
321 | { | |
322 | INSN_VAR_LOCATION_LOC (insn) = gen_rtx_UNKNOWN_VAR_LOC (); | |
323 | if (got_head) | |
324 | df_insn_rescan_debug_internal (insn); | |
325 | else | |
326 | bitmap_set_bit (rescan, INSN_UID (insn)); | |
327 | if (debug->to_rescan) | |
328 | bitmap_clear_bit (debug->to_rescan, INSN_UID (insn)); | |
329 | } | |
330 | XDELETE (head); | |
331 | head = next; | |
332 | } | |
333 | ||
334 | if (got_head) | |
335 | { | |
336 | debug->head = NULL; | |
337 | return; | |
338 | } | |
339 | ||
340 | while ((cur = *tailp)) | |
341 | if (bitmap_bit_p (rescan, INSN_UID (DF_REF_INSN (cur->use)))) | |
342 | { | |
343 | *tailp = cur->next; | |
344 | XDELETE (cur); | |
345 | } | |
346 | else | |
347 | tailp = &cur->next; | |
348 | ||
349 | EXECUTE_IF_SET_IN_BITMAP (rescan, 0, uid, bi) | |
350 | { | |
351 | struct df_insn_info *insn_info = DF_INSN_UID_SAFE_GET (uid); | |
352 | if (insn_info) | |
353 | df_insn_rescan_debug_internal (insn_info->insn); | |
354 | } | |
355 | ||
356 | BITMAP_FREE (rescan); | |
357 | } | |
358 | ||
e9f950ba AO |
359 | /* Promote pending local uses of pseudos in DEBUG to global |
360 | substitutions. Uses of non-pseudos are left alone for | |
361 | resetting. */ | |
362 | ||
363 | static void | |
364 | dead_debug_promote_uses (struct dead_debug_local *debug) | |
365 | { | |
366 | for (struct dead_debug_use *head = debug->head, **headp = &debug->head; | |
367 | head; head = *headp) | |
368 | { | |
369 | rtx reg = *DF_REF_REAL_LOC (head->use); | |
0e45ec20 AO |
370 | df_ref ref; |
371 | dead_debug_global_entry *entry; | |
e9f950ba AO |
372 | |
373 | if (GET_CODE (reg) != REG | |
374 | || REGNO (reg) < FIRST_PSEUDO_REGISTER) | |
375 | { | |
376 | headp = &head->next; | |
377 | continue; | |
378 | } | |
379 | ||
380 | if (!debug->global->used) | |
381 | debug->global->used = BITMAP_ALLOC (NULL); | |
382 | ||
383 | if (bitmap_set_bit (debug->global->used, REGNO (reg))) | |
0e45ec20 AO |
384 | entry = dead_debug_global_insert (debug->global, reg, |
385 | make_debug_expr_from_rtl (reg)); | |
e9f950ba | 386 | |
0e45ec20 AO |
387 | gcc_checking_assert (entry->dtemp); |
388 | ||
389 | /* Tentatively remove the USE from the list. */ | |
e9f950ba | 390 | *headp = head->next; |
0e45ec20 AO |
391 | |
392 | if (!debug->to_rescan) | |
393 | debug->to_rescan = BITMAP_ALLOC (NULL); | |
394 | ||
395 | for (ref = DF_REG_USE_CHAIN (REGNO (reg)); ref; | |
396 | ref = DF_REF_NEXT_REG (ref)) | |
397 | if (DEBUG_INSN_P (DF_REF_INSN (ref))) | |
398 | { | |
399 | if (!dead_debug_global_replace_temp (debug->global, ref, | |
400 | REGNO (reg), | |
401 | &debug->to_rescan)) | |
402 | { | |
403 | rtx insn = DF_REF_INSN (ref); | |
404 | INSN_VAR_LOCATION_LOC (insn) = gen_rtx_UNKNOWN_VAR_LOC (); | |
405 | bitmap_set_bit (debug->to_rescan, INSN_UID (insn)); | |
406 | } | |
407 | } | |
408 | ||
409 | for (ref = DF_REG_DEF_CHAIN (REGNO (reg)); ref; | |
410 | ref = DF_REF_NEXT_REG (ref)) | |
411 | if (!dead_debug_insert_temp (debug, REGNO (reg), DF_REF_INSN (ref), | |
412 | DEBUG_TEMP_BEFORE_WITH_VALUE)) | |
413 | { | |
414 | rtx bind; | |
415 | bind = gen_rtx_VAR_LOCATION (GET_MODE (reg), | |
416 | DEBUG_EXPR_TREE_DECL (entry->dtemp), | |
417 | gen_rtx_UNKNOWN_VAR_LOC (), | |
418 | VAR_INIT_STATUS_INITIALIZED); | |
419 | rtx insn = emit_debug_insn_before (bind, DF_REF_INSN (ref)); | |
420 | bitmap_set_bit (debug->to_rescan, INSN_UID (insn)); | |
421 | } | |
422 | ||
423 | entry->dtemp = NULL; | |
e9f950ba AO |
424 | XDELETE (head); |
425 | } | |
426 | } | |
427 | ||
08df6c0d AO |
428 | /* Reset all debug insns with pending uses. Release the bitmap in it, |
429 | unless it is USED. USED must be the same bitmap passed to | |
e9f950ba AO |
430 | dead_debug_local_init. */ |
431 | ||
08df6c0d | 432 | void |
e9f950ba | 433 | dead_debug_local_finish (struct dead_debug_local *debug, bitmap used) |
08df6c0d | 434 | { |
e9f950ba AO |
435 | if (debug->global) |
436 | dead_debug_promote_uses (debug); | |
437 | ||
0e45ec20 AO |
438 | if (debug->used != used) |
439 | BITMAP_FREE (debug->used); | |
440 | ||
08df6c0d AO |
441 | dead_debug_reset_uses (debug, debug->head); |
442 | ||
443 | if (debug->to_rescan) | |
444 | { | |
445 | bitmap_iterator bi; | |
446 | unsigned int uid; | |
447 | ||
448 | EXECUTE_IF_SET_IN_BITMAP (debug->to_rescan, 0, uid, bi) | |
449 | { | |
450 | struct df_insn_info *insn_info = DF_INSN_UID_SAFE_GET (uid); | |
451 | if (insn_info) | |
452 | df_insn_rescan (insn_info->insn); | |
453 | } | |
454 | BITMAP_FREE (debug->to_rescan); | |
455 | } | |
456 | } | |
457 | ||
e9f950ba AO |
458 | /* Release GLOBAL->used unless it is the same as USED. Release the |
459 | mapping hash table if it was initialized. */ | |
460 | ||
461 | void | |
462 | dead_debug_global_finish (struct dead_debug_global *global, bitmap used) | |
463 | { | |
464 | if (global->used != used) | |
465 | BITMAP_FREE (global->used); | |
466 | ||
467 | if (global->htab.is_created ()) | |
468 | global->htab.dispose (); | |
469 | } | |
470 | ||
471 | /* Add USE to DEBUG, or substitute it right away if it's a pseudo in | |
472 | the global substitution list. USE must be a dead reference to | |
473 | UREGNO in a debug insn. Create a bitmap for DEBUG as needed. */ | |
474 | ||
08df6c0d | 475 | void |
e9f950ba | 476 | dead_debug_add (struct dead_debug_local *debug, df_ref use, unsigned int uregno) |
08df6c0d | 477 | { |
e9f950ba AO |
478 | if (dead_debug_global_replace_temp (debug->global, use, uregno, |
479 | &debug->to_rescan)) | |
480 | return; | |
481 | ||
08df6c0d AO |
482 | struct dead_debug_use *newddu = XNEW (struct dead_debug_use); |
483 | ||
484 | newddu->use = use; | |
485 | newddu->next = debug->head; | |
486 | debug->head = newddu; | |
487 | ||
488 | if (!debug->used) | |
489 | debug->used = BITMAP_ALLOC (NULL); | |
490 | ||
491 | /* ??? If we dealt with split multi-registers below, we should set | |
492 | all registers for the used mode in case of hardware | |
493 | registers. */ | |
494 | bitmap_set_bit (debug->used, uregno); | |
495 | } | |
496 | ||
497 | /* If UREGNO is referenced by any entry in DEBUG, emit a debug insn | |
e9f950ba AO |
498 | before or after INSN (depending on WHERE), that binds a (possibly |
499 | global) debug temp to the widest-mode use of UREGNO, if WHERE is | |
500 | *_WITH_REG, or the value stored in UREGNO by INSN otherwise, and | |
501 | replace all uses of UREGNO in DEBUG with uses of the debug temp. | |
502 | INSN must be where UREGNO dies, if WHERE is *_BEFORE_*, or where it | |
503 | is set otherwise. Return the number of debug insns emitted. */ | |
504 | ||
08df6c0d | 505 | int |
e9f950ba | 506 | dead_debug_insert_temp (struct dead_debug_local *debug, unsigned int uregno, |
08df6c0d AO |
507 | rtx insn, enum debug_temp_where where) |
508 | { | |
509 | struct dead_debug_use **tailp = &debug->head; | |
510 | struct dead_debug_use *cur; | |
511 | struct dead_debug_use *uses = NULL; | |
512 | struct dead_debug_use **usesp = &uses; | |
e9f950ba | 513 | rtx reg = NULL_RTX; |
08df6c0d | 514 | rtx breg; |
e9f950ba | 515 | rtx dval = NULL_RTX; |
08df6c0d | 516 | rtx bind; |
e9f950ba | 517 | bool global; |
08df6c0d | 518 | |
e9f950ba AO |
519 | if (!debug->used) |
520 | return 0; | |
521 | ||
522 | global = (debug->global && debug->global->used | |
523 | && bitmap_bit_p (debug->global->used, uregno)); | |
524 | ||
525 | if (!global && !bitmap_clear_bit (debug->used, uregno)) | |
08df6c0d AO |
526 | return 0; |
527 | ||
528 | /* Move all uses of uregno from debug->head to uses, setting mode to | |
529 | the widest referenced mode. */ | |
530 | while ((cur = *tailp)) | |
531 | { | |
532 | if (DF_REF_REGNO (cur->use) == uregno) | |
533 | { | |
d540153b JJ |
534 | /* If this loc has been changed e.g. to debug_expr already |
535 | as part of a multi-register use, just drop it. */ | |
536 | if (!REG_P (*DF_REF_REAL_LOC (cur->use))) | |
537 | { | |
538 | *tailp = cur->next; | |
539 | XDELETE (cur); | |
540 | continue; | |
541 | } | |
08df6c0d AO |
542 | *usesp = cur; |
543 | usesp = &cur->next; | |
544 | *tailp = cur->next; | |
545 | cur->next = NULL; | |
546 | if (!reg | |
547 | || (GET_MODE_BITSIZE (GET_MODE (reg)) | |
548 | < GET_MODE_BITSIZE (GET_MODE (*DF_REF_REAL_LOC (cur->use))))) | |
549 | reg = *DF_REF_REAL_LOC (cur->use); | |
550 | } | |
551 | else | |
552 | tailp = &(*tailp)->next; | |
553 | } | |
554 | ||
555 | /* We may have dangling bits in debug->used for registers that were part | |
556 | of a multi-register use, one component of which has been reset. */ | |
557 | if (reg == NULL) | |
558 | { | |
559 | gcc_checking_assert (!uses); | |
e9f950ba AO |
560 | if (!global) |
561 | return 0; | |
562 | } | |
563 | ||
564 | if (global) | |
565 | { | |
566 | if (!reg) | |
567 | reg = regno_reg_rtx[uregno]; | |
568 | dead_debug_global_entry *entry | |
569 | = dead_debug_global_find (debug->global, reg); | |
570 | gcc_checking_assert (entry->reg == reg); | |
571 | dval = entry->dtemp; | |
0e45ec20 AO |
572 | if (!dval) |
573 | return 0; | |
08df6c0d AO |
574 | } |
575 | ||
e9f950ba | 576 | gcc_checking_assert (uses || global); |
08df6c0d AO |
577 | |
578 | breg = reg; | |
579 | /* Recover the expression INSN stores in REG. */ | |
580 | if (where == DEBUG_TEMP_BEFORE_WITH_VALUE) | |
581 | { | |
582 | rtx set = single_set (insn); | |
583 | rtx dest, src; | |
584 | ||
585 | if (set) | |
586 | { | |
587 | dest = SET_DEST (set); | |
588 | src = SET_SRC (set); | |
589 | /* Lose if the REG-setting insn is a CALL. */ | |
590 | if (GET_CODE (src) == CALL) | |
591 | { | |
592 | while (uses) | |
593 | { | |
594 | cur = uses->next; | |
595 | XDELETE (uses); | |
596 | uses = cur; | |
597 | } | |
598 | return 0; | |
599 | } | |
600 | } | |
601 | ||
602 | /* ??? Should we try to extract it from a PARALLEL? */ | |
603 | if (!set) | |
604 | breg = NULL; | |
605 | /* Cool, it's the same REG, we can use SRC. */ | |
606 | else if (dest == reg) | |
e7206ab1 | 607 | breg = cleanup_auto_inc_dec (src, VOIDmode); |
08df6c0d AO |
608 | else if (REG_P (dest)) |
609 | { | |
610 | /* Hmm... Something's fishy, we should be setting REG here. */ | |
611 | if (REGNO (dest) != REGNO (reg)) | |
612 | breg = NULL; | |
613 | /* If we're not overwriting all the hardware registers that | |
614 | setting REG in its mode would, we won't know what to bind | |
615 | the debug temp to. ??? We could bind the debug_expr to a | |
616 | CONCAT or PARALLEL with the split multi-registers, and | |
617 | replace them as we found the corresponding sets. */ | |
618 | else if (REGNO (reg) < FIRST_PSEUDO_REGISTER | |
619 | && (hard_regno_nregs[REGNO (reg)][GET_MODE (reg)] | |
620 | != hard_regno_nregs[REGNO (reg)][GET_MODE (dest)])) | |
621 | breg = NULL; | |
622 | /* Ok, it's the same (hardware) REG, but with a different | |
623 | mode, so SUBREG it. */ | |
624 | else | |
e7206ab1 AO |
625 | breg = lowpart_subreg (GET_MODE (reg), |
626 | cleanup_auto_inc_dec (src, VOIDmode), | |
08df6c0d AO |
627 | GET_MODE (dest)); |
628 | } | |
629 | else if (GET_CODE (dest) == SUBREG) | |
630 | { | |
631 | /* We should be setting REG here. Lose. */ | |
632 | if (REGNO (SUBREG_REG (dest)) != REGNO (reg)) | |
633 | breg = NULL; | |
634 | /* Lose if we're setting something other than the lowpart of | |
635 | REG. */ | |
636 | else if (!subreg_lowpart_p (dest)) | |
637 | breg = NULL; | |
638 | /* If we're not overwriting all the hardware registers that | |
639 | setting REG in its mode would, we won't know what to bind | |
640 | the debug temp to. */ | |
641 | else if (REGNO (reg) < FIRST_PSEUDO_REGISTER | |
642 | && (hard_regno_nregs[REGNO (reg)][GET_MODE (reg)] | |
643 | != hard_regno_nregs[REGNO (reg)][GET_MODE (dest)])) | |
644 | breg = NULL; | |
645 | /* Yay, we can use SRC, just adjust its mode. */ | |
646 | else | |
e7206ab1 AO |
647 | breg = lowpart_subreg (GET_MODE (reg), |
648 | cleanup_auto_inc_dec (src, VOIDmode), | |
08df6c0d AO |
649 | GET_MODE (dest)); |
650 | } | |
651 | /* Oh well, we're out of luck. */ | |
652 | else | |
653 | breg = NULL; | |
654 | ||
655 | /* We couldn't figure out the value stored in REG, so reset all | |
656 | of its pending debug uses. */ | |
657 | if (!breg) | |
658 | { | |
659 | dead_debug_reset_uses (debug, uses); | |
660 | return 0; | |
661 | } | |
662 | } | |
663 | ||
664 | /* If there's a single (debug) use of an otherwise unused REG, and | |
665 | the debug use is not part of a larger expression, then it | |
666 | probably doesn't make sense to introduce a new debug temp. */ | |
667 | if (where == DEBUG_TEMP_AFTER_WITH_REG && !uses->next) | |
668 | { | |
669 | rtx next = DF_REF_INSN (uses->use); | |
670 | ||
671 | if (DEBUG_INSN_P (next) && reg == INSN_VAR_LOCATION_LOC (next)) | |
672 | { | |
673 | XDELETE (uses); | |
674 | return 0; | |
675 | } | |
676 | } | |
677 | ||
e9f950ba AO |
678 | if (!global) |
679 | /* Create DEBUG_EXPR (and DEBUG_EXPR_DECL). */ | |
680 | dval = make_debug_expr_from_rtl (reg); | |
08df6c0d AO |
681 | |
682 | /* Emit a debug bind insn before the insn in which reg dies. */ | |
683 | bind = gen_rtx_VAR_LOCATION (GET_MODE (reg), | |
684 | DEBUG_EXPR_TREE_DECL (dval), breg, | |
685 | VAR_INIT_STATUS_INITIALIZED); | |
686 | ||
85d87497 JJ |
687 | if (where == DEBUG_TEMP_AFTER_WITH_REG |
688 | || where == DEBUG_TEMP_AFTER_WITH_REG_FORCE) | |
08df6c0d AO |
689 | bind = emit_debug_insn_after (bind, insn); |
690 | else | |
691 | bind = emit_debug_insn_before (bind, insn); | |
36290bb4 AO |
692 | if (debug->to_rescan == NULL) |
693 | debug->to_rescan = BITMAP_ALLOC (NULL); | |
694 | bitmap_set_bit (debug->to_rescan, INSN_UID (bind)); | |
08df6c0d AO |
695 | |
696 | /* Adjust all uses. */ | |
697 | while ((cur = uses)) | |
698 | { | |
699 | if (GET_MODE (*DF_REF_REAL_LOC (cur->use)) == GET_MODE (reg)) | |
700 | *DF_REF_REAL_LOC (cur->use) = dval; | |
701 | else | |
702 | *DF_REF_REAL_LOC (cur->use) | |
703 | = gen_lowpart_SUBREG (GET_MODE (*DF_REF_REAL_LOC (cur->use)), dval); | |
704 | /* ??? Should we simplify subreg of subreg? */ | |
08df6c0d AO |
705 | bitmap_set_bit (debug->to_rescan, INSN_UID (DF_REF_INSN (cur->use))); |
706 | uses = cur->next; | |
707 | XDELETE (cur); | |
708 | } | |
709 | ||
710 | return 1; | |
711 | } |