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08df6c0d AO |
1 | /* Infrastructure for tracking user variable locations and values |
2 | throughout compilation. | |
23a5b65a | 3 | Copyright (C) 2010-2014 Free Software Foundation, Inc. |
08df6c0d AO |
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 | ||
e90c56c6 JJ |
32 | /* gen_lowpart_no_emit hook implementation for DEBUG_INSNs. In DEBUG_INSNs, |
33 | all lowpart SUBREGs are valid, despite what the machine requires for | |
34 | instructions. */ | |
35 | ||
36 | static rtx | |
37 | gen_lowpart_for_debug (enum machine_mode mode, rtx x) | |
38 | { | |
39 | rtx result = gen_lowpart_if_possible (mode, x); | |
40 | if (result) | |
41 | return result; | |
42 | ||
43 | if (GET_MODE (x) != VOIDmode) | |
44 | return gen_rtx_raw_SUBREG (mode, x, | |
45 | subreg_lowpart_offset (mode, GET_MODE (x))); | |
46 | ||
47 | return NULL_RTX; | |
48 | } | |
49 | ||
08df6c0d AO |
50 | /* Replace auto-increment addressing modes with explicit operations to access |
51 | the same addresses without modifying the corresponding registers. */ | |
52 | ||
08df6c0d AO |
53 | static rtx |
54 | cleanup_auto_inc_dec (rtx src, enum machine_mode mem_mode ATTRIBUTE_UNUSED) | |
55 | { | |
56 | rtx x = src; | |
375e3d07 | 57 | #ifdef AUTO_INC_DEC |
08df6c0d AO |
58 | const RTX_CODE code = GET_CODE (x); |
59 | int i; | |
60 | const char *fmt; | |
61 | ||
62 | switch (code) | |
63 | { | |
64 | case REG: | |
d8116890 | 65 | CASE_CONST_ANY: |
08df6c0d AO |
66 | case SYMBOL_REF: |
67 | case CODE_LABEL: | |
68 | case PC: | |
69 | case CC0: | |
70 | case SCRATCH: | |
71 | /* SCRATCH must be shared because they represent distinct values. */ | |
72 | return x; | |
73 | case CLOBBER: | |
c5c5ba89 JH |
74 | /* Share clobbers of hard registers (like cc0), but do not share pseudo reg |
75 | clobbers or clobbers of hard registers that originated as pseudos. | |
76 | This is needed to allow safe register renaming. */ | |
77 | if (REG_P (XEXP (x, 0)) && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER | |
78 | && ORIGINAL_REGNO (XEXP (x, 0)) == REGNO (XEXP (x, 0))) | |
08df6c0d AO |
79 | return x; |
80 | break; | |
81 | ||
82 | case CONST: | |
83 | if (shared_const_p (x)) | |
84 | return x; | |
85 | break; | |
86 | ||
87 | case MEM: | |
88 | mem_mode = GET_MODE (x); | |
89 | break; | |
90 | ||
91 | case PRE_INC: | |
92 | case PRE_DEC: | |
93 | gcc_assert (mem_mode != VOIDmode && mem_mode != BLKmode); | |
94 | return gen_rtx_PLUS (GET_MODE (x), | |
95 | cleanup_auto_inc_dec (XEXP (x, 0), mem_mode), | |
4789c0ce RS |
96 | gen_int_mode (code == PRE_INC |
97 | ? GET_MODE_SIZE (mem_mode) | |
98 | : -GET_MODE_SIZE (mem_mode), | |
99 | GET_MODE (x))); | |
08df6c0d AO |
100 | |
101 | case POST_INC: | |
102 | case POST_DEC: | |
103 | case PRE_MODIFY: | |
104 | case POST_MODIFY: | |
105 | return cleanup_auto_inc_dec (code == PRE_MODIFY | |
106 | ? XEXP (x, 1) : XEXP (x, 0), | |
107 | mem_mode); | |
108 | ||
109 | default: | |
110 | break; | |
111 | } | |
112 | ||
113 | /* Copy the various flags, fields, and other information. We assume | |
114 | that all fields need copying, and then clear the fields that should | |
115 | not be copied. That is the sensible default behavior, and forces | |
116 | us to explicitly document why we are *not* copying a flag. */ | |
117 | x = shallow_copy_rtx (x); | |
118 | ||
119 | /* We do not copy the USED flag, which is used as a mark bit during | |
120 | walks over the RTL. */ | |
121 | RTX_FLAG (x, used) = 0; | |
122 | ||
123 | /* We do not copy FRAME_RELATED for INSNs. */ | |
124 | if (INSN_P (x)) | |
125 | RTX_FLAG (x, frame_related) = 0; | |
126 | ||
127 | fmt = GET_RTX_FORMAT (code); | |
128 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
129 | if (fmt[i] == 'e') | |
130 | XEXP (x, i) = cleanup_auto_inc_dec (XEXP (x, i), mem_mode); | |
131 | else if (fmt[i] == 'E' || fmt[i] == 'V') | |
132 | { | |
133 | int j; | |
134 | XVEC (x, i) = rtvec_alloc (XVECLEN (x, i)); | |
135 | for (j = 0; j < XVECLEN (x, i); j++) | |
136 | XVECEXP (x, i, j) | |
137 | = cleanup_auto_inc_dec (XVECEXP (src, i, j), mem_mode); | |
138 | } | |
139 | ||
375e3d07 AO |
140 | #else /* !AUTO_INC_DEC */ |
141 | x = copy_rtx (x); | |
142 | #endif /* !AUTO_INC_DEC */ | |
143 | ||
08df6c0d AO |
144 | return x; |
145 | } | |
08df6c0d AO |
146 | |
147 | /* Auxiliary data structure for propagate_for_debug_stmt. */ | |
148 | ||
149 | struct rtx_subst_pair | |
150 | { | |
151 | rtx to; | |
152 | bool adjusted; | |
153 | }; | |
154 | ||
155 | /* DATA points to an rtx_subst_pair. Return the value that should be | |
156 | substituted. */ | |
157 | ||
158 | static rtx | |
159 | propagate_for_debug_subst (rtx from, const_rtx old_rtx, void *data) | |
160 | { | |
161 | struct rtx_subst_pair *pair = (struct rtx_subst_pair *)data; | |
162 | ||
163 | if (!rtx_equal_p (from, old_rtx)) | |
164 | return NULL_RTX; | |
165 | if (!pair->adjusted) | |
166 | { | |
167 | pair->adjusted = true; | |
08df6c0d | 168 | pair->to = cleanup_auto_inc_dec (pair->to, VOIDmode); |
08df6c0d AO |
169 | pair->to = make_compound_operation (pair->to, SET); |
170 | return pair->to; | |
171 | } | |
172 | return copy_rtx (pair->to); | |
173 | } | |
174 | ||
175 | /* Replace all the occurrences of DEST with SRC in DEBUG_INSNs between INSN | |
176 | and LAST, not including INSN, but including LAST. Also stop at the end | |
177 | of THIS_BASIC_BLOCK. */ | |
178 | ||
179 | void | |
180 | propagate_for_debug (rtx insn, rtx last, rtx dest, rtx src, | |
181 | basic_block this_basic_block) | |
182 | { | |
183 | rtx next, loc, end = NEXT_INSN (BB_END (this_basic_block)); | |
e90c56c6 | 184 | rtx (*saved_rtl_hook_no_emit) (enum machine_mode, rtx); |
08df6c0d AO |
185 | |
186 | struct rtx_subst_pair p; | |
187 | p.to = src; | |
188 | p.adjusted = false; | |
189 | ||
190 | next = NEXT_INSN (insn); | |
191 | last = NEXT_INSN (last); | |
e90c56c6 JJ |
192 | saved_rtl_hook_no_emit = rtl_hooks.gen_lowpart_no_emit; |
193 | rtl_hooks.gen_lowpart_no_emit = gen_lowpart_for_debug; | |
08df6c0d AO |
194 | while (next != last && next != end) |
195 | { | |
196 | insn = next; | |
197 | next = NEXT_INSN (insn); | |
198 | if (DEBUG_INSN_P (insn)) | |
199 | { | |
200 | loc = simplify_replace_fn_rtx (INSN_VAR_LOCATION_LOC (insn), | |
201 | dest, propagate_for_debug_subst, &p); | |
202 | if (loc == INSN_VAR_LOCATION_LOC (insn)) | |
203 | continue; | |
204 | INSN_VAR_LOCATION_LOC (insn) = loc; | |
205 | df_insn_rescan (insn); | |
206 | } | |
207 | } | |
e90c56c6 | 208 | rtl_hooks.gen_lowpart_no_emit = saved_rtl_hook_no_emit; |
08df6c0d AO |
209 | } |
210 | ||
211 | /* Initialize DEBUG to an empty list, and clear USED, if given. */ | |
e9f950ba AO |
212 | |
213 | void | |
214 | dead_debug_global_init (struct dead_debug_global *debug, bitmap used) | |
215 | { | |
216 | debug->used = used; | |
c203e8a7 | 217 | debug->htab = NULL; |
e9f950ba AO |
218 | if (used) |
219 | bitmap_clear (used); | |
220 | } | |
221 | ||
222 | /* Initialize DEBUG to an empty list, and clear USED, if given. Link | |
223 | back to GLOBAL, if given, and bring in used bits from it. */ | |
224 | ||
08df6c0d | 225 | void |
e9f950ba AO |
226 | dead_debug_local_init (struct dead_debug_local *debug, bitmap used, |
227 | struct dead_debug_global *global) | |
08df6c0d | 228 | { |
e9f950ba AO |
229 | if (!used && global && global->used) |
230 | used = BITMAP_ALLOC (NULL); | |
231 | ||
08df6c0d | 232 | debug->head = NULL; |
e9f950ba | 233 | debug->global = global; |
08df6c0d AO |
234 | debug->used = used; |
235 | debug->to_rescan = NULL; | |
e9f950ba | 236 | |
08df6c0d | 237 | if (used) |
e9f950ba AO |
238 | { |
239 | if (global && global->used) | |
240 | bitmap_copy (used, global->used); | |
241 | else | |
242 | bitmap_clear (used); | |
243 | } | |
244 | } | |
245 | ||
246 | /* Locate the entry for REG in GLOBAL->htab. */ | |
247 | ||
248 | static dead_debug_global_entry * | |
249 | dead_debug_global_find (struct dead_debug_global *global, rtx reg) | |
250 | { | |
251 | dead_debug_global_entry temp_entry; | |
252 | temp_entry.reg = reg; | |
253 | ||
c203e8a7 | 254 | dead_debug_global_entry *entry = global->htab->find (&temp_entry); |
e9f950ba | 255 | gcc_checking_assert (entry && entry->reg == temp_entry.reg); |
e9f950ba AO |
256 | |
257 | return entry; | |
258 | } | |
259 | ||
260 | /* Insert an entry mapping REG to DTEMP in GLOBAL->htab. */ | |
261 | ||
0e45ec20 | 262 | static dead_debug_global_entry * |
e9f950ba AO |
263 | dead_debug_global_insert (struct dead_debug_global *global, rtx reg, rtx dtemp) |
264 | { | |
265 | dead_debug_global_entry temp_entry; | |
266 | temp_entry.reg = reg; | |
267 | temp_entry.dtemp = dtemp; | |
268 | ||
c203e8a7 TS |
269 | if (!global->htab) |
270 | global->htab = new hash_table<dead_debug_hash_descr> (31); | |
e9f950ba | 271 | |
c203e8a7 TS |
272 | dead_debug_global_entry **slot = global->htab->find_slot (&temp_entry, |
273 | INSERT); | |
e9f950ba AO |
274 | gcc_checking_assert (!*slot); |
275 | *slot = XNEW (dead_debug_global_entry); | |
276 | **slot = temp_entry; | |
0e45ec20 | 277 | return *slot; |
e9f950ba AO |
278 | } |
279 | ||
280 | /* If UREGNO, referenced by USE, is a pseudo marked as used in GLOBAL, | |
281 | replace it with with a USE of the debug temp recorded for it, and | |
282 | return TRUE. Otherwise, just return FALSE. | |
283 | ||
284 | If PTO_RESCAN is given, instead of rescanning modified INSNs right | |
285 | away, add their UIDs to the bitmap, allocating one of *PTO_RESCAN | |
286 | is NULL. */ | |
287 | ||
288 | static bool | |
289 | dead_debug_global_replace_temp (struct dead_debug_global *global, | |
290 | df_ref use, unsigned int uregno, | |
291 | bitmap *pto_rescan) | |
292 | { | |
293 | if (!global || uregno < FIRST_PSEUDO_REGISTER | |
294 | || !global->used | |
0e45ec20 AO |
295 | || !REG_P (*DF_REF_REAL_LOC (use)) |
296 | || REGNO (*DF_REF_REAL_LOC (use)) != uregno | |
e9f950ba AO |
297 | || !bitmap_bit_p (global->used, uregno)) |
298 | return false; | |
299 | ||
e9f950ba AO |
300 | dead_debug_global_entry *entry |
301 | = dead_debug_global_find (global, *DF_REF_REAL_LOC (use)); | |
302 | gcc_checking_assert (GET_CODE (entry->reg) == REG | |
303 | && REGNO (entry->reg) == uregno); | |
304 | ||
0e45ec20 AO |
305 | if (!entry->dtemp) |
306 | return true; | |
307 | ||
e9f950ba AO |
308 | *DF_REF_REAL_LOC (use) = entry->dtemp; |
309 | if (!pto_rescan) | |
310 | df_insn_rescan (DF_REF_INSN (use)); | |
311 | else | |
312 | { | |
313 | if (!*pto_rescan) | |
314 | *pto_rescan = BITMAP_ALLOC (NULL); | |
315 | bitmap_set_bit (*pto_rescan, INSN_UID (DF_REF_INSN (use))); | |
316 | } | |
317 | ||
318 | return true; | |
08df6c0d AO |
319 | } |
320 | ||
321 | /* Reset all debug uses in HEAD, and clear DEBUG->to_rescan bits of | |
322 | each reset insn. DEBUG is not otherwise modified. If HEAD is | |
323 | DEBUG->head, DEBUG->head will be set to NULL at the end. | |
324 | Otherwise, entries from DEBUG->head that pertain to reset insns | |
325 | will be removed, and only then rescanned. */ | |
326 | ||
327 | static void | |
e9f950ba AO |
328 | dead_debug_reset_uses (struct dead_debug_local *debug, |
329 | struct dead_debug_use *head) | |
08df6c0d AO |
330 | { |
331 | bool got_head = (debug->head == head); | |
332 | bitmap rescan; | |
333 | struct dead_debug_use **tailp = &debug->head; | |
334 | struct dead_debug_use *cur; | |
335 | bitmap_iterator bi; | |
336 | unsigned int uid; | |
337 | ||
338 | if (got_head) | |
339 | rescan = NULL; | |
340 | else | |
341 | rescan = BITMAP_ALLOC (NULL); | |
342 | ||
343 | while (head) | |
344 | { | |
345 | struct dead_debug_use *next = head->next; | |
346 | rtx insn; | |
347 | ||
348 | insn = DF_REF_INSN (head->use); | |
349 | if (!next || DF_REF_INSN (next->use) != insn) | |
350 | { | |
351 | INSN_VAR_LOCATION_LOC (insn) = gen_rtx_UNKNOWN_VAR_LOC (); | |
352 | if (got_head) | |
353 | df_insn_rescan_debug_internal (insn); | |
354 | else | |
355 | bitmap_set_bit (rescan, INSN_UID (insn)); | |
356 | if (debug->to_rescan) | |
357 | bitmap_clear_bit (debug->to_rescan, INSN_UID (insn)); | |
358 | } | |
359 | XDELETE (head); | |
360 | head = next; | |
361 | } | |
362 | ||
363 | if (got_head) | |
364 | { | |
365 | debug->head = NULL; | |
366 | return; | |
367 | } | |
368 | ||
369 | while ((cur = *tailp)) | |
370 | if (bitmap_bit_p (rescan, INSN_UID (DF_REF_INSN (cur->use)))) | |
371 | { | |
372 | *tailp = cur->next; | |
373 | XDELETE (cur); | |
374 | } | |
375 | else | |
376 | tailp = &cur->next; | |
377 | ||
378 | EXECUTE_IF_SET_IN_BITMAP (rescan, 0, uid, bi) | |
379 | { | |
380 | struct df_insn_info *insn_info = DF_INSN_UID_SAFE_GET (uid); | |
381 | if (insn_info) | |
382 | df_insn_rescan_debug_internal (insn_info->insn); | |
383 | } | |
384 | ||
385 | BITMAP_FREE (rescan); | |
386 | } | |
387 | ||
e9f950ba AO |
388 | /* Promote pending local uses of pseudos in DEBUG to global |
389 | substitutions. Uses of non-pseudos are left alone for | |
390 | resetting. */ | |
391 | ||
392 | static void | |
393 | dead_debug_promote_uses (struct dead_debug_local *debug) | |
394 | { | |
395 | for (struct dead_debug_use *head = debug->head, **headp = &debug->head; | |
396 | head; head = *headp) | |
397 | { | |
398 | rtx reg = *DF_REF_REAL_LOC (head->use); | |
0e45ec20 AO |
399 | df_ref ref; |
400 | dead_debug_global_entry *entry; | |
e9f950ba AO |
401 | |
402 | if (GET_CODE (reg) != REG | |
403 | || REGNO (reg) < FIRST_PSEUDO_REGISTER) | |
404 | { | |
405 | headp = &head->next; | |
406 | continue; | |
407 | } | |
408 | ||
409 | if (!debug->global->used) | |
410 | debug->global->used = BITMAP_ALLOC (NULL); | |
411 | ||
f39b1a1a AO |
412 | bool added = bitmap_set_bit (debug->global->used, REGNO (reg)); |
413 | gcc_checking_assert (added); | |
414 | ||
415 | entry = dead_debug_global_insert (debug->global, reg, | |
416 | make_debug_expr_from_rtl (reg)); | |
e9f950ba | 417 | |
0e45ec20 AO |
418 | gcc_checking_assert (entry->dtemp); |
419 | ||
420 | /* Tentatively remove the USE from the list. */ | |
e9f950ba | 421 | *headp = head->next; |
0e45ec20 AO |
422 | |
423 | if (!debug->to_rescan) | |
424 | debug->to_rescan = BITMAP_ALLOC (NULL); | |
425 | ||
426 | for (ref = DF_REG_USE_CHAIN (REGNO (reg)); ref; | |
427 | ref = DF_REF_NEXT_REG (ref)) | |
428 | if (DEBUG_INSN_P (DF_REF_INSN (ref))) | |
429 | { | |
430 | if (!dead_debug_global_replace_temp (debug->global, ref, | |
431 | REGNO (reg), | |
432 | &debug->to_rescan)) | |
433 | { | |
434 | rtx insn = DF_REF_INSN (ref); | |
435 | INSN_VAR_LOCATION_LOC (insn) = gen_rtx_UNKNOWN_VAR_LOC (); | |
436 | bitmap_set_bit (debug->to_rescan, INSN_UID (insn)); | |
437 | } | |
438 | } | |
439 | ||
440 | for (ref = DF_REG_DEF_CHAIN (REGNO (reg)); ref; | |
441 | ref = DF_REF_NEXT_REG (ref)) | |
442 | if (!dead_debug_insert_temp (debug, REGNO (reg), DF_REF_INSN (ref), | |
443 | DEBUG_TEMP_BEFORE_WITH_VALUE)) | |
444 | { | |
445 | rtx bind; | |
446 | bind = gen_rtx_VAR_LOCATION (GET_MODE (reg), | |
447 | DEBUG_EXPR_TREE_DECL (entry->dtemp), | |
448 | gen_rtx_UNKNOWN_VAR_LOC (), | |
449 | VAR_INIT_STATUS_INITIALIZED); | |
450 | rtx insn = emit_debug_insn_before (bind, DF_REF_INSN (ref)); | |
451 | bitmap_set_bit (debug->to_rescan, INSN_UID (insn)); | |
452 | } | |
453 | ||
454 | entry->dtemp = NULL; | |
e9f950ba AO |
455 | XDELETE (head); |
456 | } | |
457 | } | |
458 | ||
08df6c0d AO |
459 | /* Reset all debug insns with pending uses. Release the bitmap in it, |
460 | unless it is USED. USED must be the same bitmap passed to | |
e9f950ba AO |
461 | dead_debug_local_init. */ |
462 | ||
08df6c0d | 463 | void |
e9f950ba | 464 | dead_debug_local_finish (struct dead_debug_local *debug, bitmap used) |
08df6c0d | 465 | { |
e9f950ba AO |
466 | if (debug->global) |
467 | dead_debug_promote_uses (debug); | |
468 | ||
0e45ec20 AO |
469 | if (debug->used != used) |
470 | BITMAP_FREE (debug->used); | |
471 | ||
08df6c0d AO |
472 | dead_debug_reset_uses (debug, debug->head); |
473 | ||
474 | if (debug->to_rescan) | |
475 | { | |
476 | bitmap_iterator bi; | |
477 | unsigned int uid; | |
478 | ||
479 | EXECUTE_IF_SET_IN_BITMAP (debug->to_rescan, 0, uid, bi) | |
480 | { | |
481 | struct df_insn_info *insn_info = DF_INSN_UID_SAFE_GET (uid); | |
482 | if (insn_info) | |
483 | df_insn_rescan (insn_info->insn); | |
484 | } | |
485 | BITMAP_FREE (debug->to_rescan); | |
486 | } | |
487 | } | |
488 | ||
e9f950ba AO |
489 | /* Release GLOBAL->used unless it is the same as USED. Release the |
490 | mapping hash table if it was initialized. */ | |
491 | ||
492 | void | |
493 | dead_debug_global_finish (struct dead_debug_global *global, bitmap used) | |
494 | { | |
495 | if (global->used != used) | |
496 | BITMAP_FREE (global->used); | |
497 | ||
c203e8a7 TS |
498 | delete global->htab; |
499 | global->htab = NULL; | |
e9f950ba AO |
500 | } |
501 | ||
502 | /* Add USE to DEBUG, or substitute it right away if it's a pseudo in | |
503 | the global substitution list. USE must be a dead reference to | |
504 | UREGNO in a debug insn. Create a bitmap for DEBUG as needed. */ | |
505 | ||
08df6c0d | 506 | void |
e9f950ba | 507 | dead_debug_add (struct dead_debug_local *debug, df_ref use, unsigned int uregno) |
08df6c0d | 508 | { |
e9f950ba AO |
509 | if (dead_debug_global_replace_temp (debug->global, use, uregno, |
510 | &debug->to_rescan)) | |
511 | return; | |
512 | ||
08df6c0d AO |
513 | struct dead_debug_use *newddu = XNEW (struct dead_debug_use); |
514 | ||
515 | newddu->use = use; | |
516 | newddu->next = debug->head; | |
517 | debug->head = newddu; | |
518 | ||
519 | if (!debug->used) | |
520 | debug->used = BITMAP_ALLOC (NULL); | |
521 | ||
522 | /* ??? If we dealt with split multi-registers below, we should set | |
523 | all registers for the used mode in case of hardware | |
524 | registers. */ | |
525 | bitmap_set_bit (debug->used, uregno); | |
526 | } | |
527 | ||
528 | /* If UREGNO is referenced by any entry in DEBUG, emit a debug insn | |
e9f950ba AO |
529 | before or after INSN (depending on WHERE), that binds a (possibly |
530 | global) debug temp to the widest-mode use of UREGNO, if WHERE is | |
531 | *_WITH_REG, or the value stored in UREGNO by INSN otherwise, and | |
532 | replace all uses of UREGNO in DEBUG with uses of the debug temp. | |
533 | INSN must be where UREGNO dies, if WHERE is *_BEFORE_*, or where it | |
534 | is set otherwise. Return the number of debug insns emitted. */ | |
535 | ||
08df6c0d | 536 | int |
e9f950ba | 537 | dead_debug_insert_temp (struct dead_debug_local *debug, unsigned int uregno, |
08df6c0d AO |
538 | rtx insn, enum debug_temp_where where) |
539 | { | |
540 | struct dead_debug_use **tailp = &debug->head; | |
541 | struct dead_debug_use *cur; | |
542 | struct dead_debug_use *uses = NULL; | |
543 | struct dead_debug_use **usesp = &uses; | |
e9f950ba | 544 | rtx reg = NULL_RTX; |
08df6c0d | 545 | rtx breg; |
e9f950ba | 546 | rtx dval = NULL_RTX; |
08df6c0d | 547 | rtx bind; |
e9f950ba | 548 | bool global; |
08df6c0d | 549 | |
e9f950ba AO |
550 | if (!debug->used) |
551 | return 0; | |
552 | ||
553 | global = (debug->global && debug->global->used | |
554 | && bitmap_bit_p (debug->global->used, uregno)); | |
555 | ||
556 | if (!global && !bitmap_clear_bit (debug->used, uregno)) | |
08df6c0d AO |
557 | return 0; |
558 | ||
559 | /* Move all uses of uregno from debug->head to uses, setting mode to | |
560 | the widest referenced mode. */ | |
561 | while ((cur = *tailp)) | |
562 | { | |
563 | if (DF_REF_REGNO (cur->use) == uregno) | |
564 | { | |
d540153b JJ |
565 | /* If this loc has been changed e.g. to debug_expr already |
566 | as part of a multi-register use, just drop it. */ | |
567 | if (!REG_P (*DF_REF_REAL_LOC (cur->use))) | |
568 | { | |
569 | *tailp = cur->next; | |
570 | XDELETE (cur); | |
571 | continue; | |
572 | } | |
08df6c0d AO |
573 | *usesp = cur; |
574 | usesp = &cur->next; | |
575 | *tailp = cur->next; | |
576 | cur->next = NULL; | |
577 | if (!reg | |
578 | || (GET_MODE_BITSIZE (GET_MODE (reg)) | |
579 | < GET_MODE_BITSIZE (GET_MODE (*DF_REF_REAL_LOC (cur->use))))) | |
580 | reg = *DF_REF_REAL_LOC (cur->use); | |
581 | } | |
582 | else | |
583 | tailp = &(*tailp)->next; | |
584 | } | |
585 | ||
586 | /* We may have dangling bits in debug->used for registers that were part | |
587 | of a multi-register use, one component of which has been reset. */ | |
588 | if (reg == NULL) | |
589 | { | |
590 | gcc_checking_assert (!uses); | |
e9f950ba AO |
591 | if (!global) |
592 | return 0; | |
593 | } | |
594 | ||
595 | if (global) | |
596 | { | |
597 | if (!reg) | |
598 | reg = regno_reg_rtx[uregno]; | |
599 | dead_debug_global_entry *entry | |
600 | = dead_debug_global_find (debug->global, reg); | |
601 | gcc_checking_assert (entry->reg == reg); | |
602 | dval = entry->dtemp; | |
0e45ec20 AO |
603 | if (!dval) |
604 | return 0; | |
08df6c0d AO |
605 | } |
606 | ||
e9f950ba | 607 | gcc_checking_assert (uses || global); |
08df6c0d AO |
608 | |
609 | breg = reg; | |
610 | /* Recover the expression INSN stores in REG. */ | |
611 | if (where == DEBUG_TEMP_BEFORE_WITH_VALUE) | |
612 | { | |
613 | rtx set = single_set (insn); | |
614 | rtx dest, src; | |
615 | ||
616 | if (set) | |
617 | { | |
618 | dest = SET_DEST (set); | |
619 | src = SET_SRC (set); | |
620 | /* Lose if the REG-setting insn is a CALL. */ | |
621 | if (GET_CODE (src) == CALL) | |
622 | { | |
623 | while (uses) | |
624 | { | |
625 | cur = uses->next; | |
626 | XDELETE (uses); | |
627 | uses = cur; | |
628 | } | |
629 | return 0; | |
630 | } | |
631 | } | |
632 | ||
633 | /* ??? Should we try to extract it from a PARALLEL? */ | |
634 | if (!set) | |
635 | breg = NULL; | |
636 | /* Cool, it's the same REG, we can use SRC. */ | |
637 | else if (dest == reg) | |
e7206ab1 | 638 | breg = cleanup_auto_inc_dec (src, VOIDmode); |
08df6c0d AO |
639 | else if (REG_P (dest)) |
640 | { | |
641 | /* Hmm... Something's fishy, we should be setting REG here. */ | |
642 | if (REGNO (dest) != REGNO (reg)) | |
643 | breg = NULL; | |
644 | /* If we're not overwriting all the hardware registers that | |
645 | setting REG in its mode would, we won't know what to bind | |
646 | the debug temp to. ??? We could bind the debug_expr to a | |
647 | CONCAT or PARALLEL with the split multi-registers, and | |
648 | replace them as we found the corresponding sets. */ | |
649 | else if (REGNO (reg) < FIRST_PSEUDO_REGISTER | |
650 | && (hard_regno_nregs[REGNO (reg)][GET_MODE (reg)] | |
651 | != hard_regno_nregs[REGNO (reg)][GET_MODE (dest)])) | |
652 | breg = NULL; | |
653 | /* Ok, it's the same (hardware) REG, but with a different | |
654 | mode, so SUBREG it. */ | |
655 | else | |
e7206ab1 AO |
656 | breg = lowpart_subreg (GET_MODE (reg), |
657 | cleanup_auto_inc_dec (src, VOIDmode), | |
08df6c0d AO |
658 | GET_MODE (dest)); |
659 | } | |
660 | else if (GET_CODE (dest) == SUBREG) | |
661 | { | |
662 | /* We should be setting REG here. Lose. */ | |
663 | if (REGNO (SUBREG_REG (dest)) != REGNO (reg)) | |
664 | breg = NULL; | |
665 | /* Lose if we're setting something other than the lowpart of | |
666 | REG. */ | |
667 | else if (!subreg_lowpart_p (dest)) | |
668 | breg = NULL; | |
669 | /* If we're not overwriting all the hardware registers that | |
670 | setting REG in its mode would, we won't know what to bind | |
671 | the debug temp to. */ | |
672 | else if (REGNO (reg) < FIRST_PSEUDO_REGISTER | |
673 | && (hard_regno_nregs[REGNO (reg)][GET_MODE (reg)] | |
674 | != hard_regno_nregs[REGNO (reg)][GET_MODE (dest)])) | |
675 | breg = NULL; | |
676 | /* Yay, we can use SRC, just adjust its mode. */ | |
677 | else | |
e7206ab1 AO |
678 | breg = lowpart_subreg (GET_MODE (reg), |
679 | cleanup_auto_inc_dec (src, VOIDmode), | |
08df6c0d AO |
680 | GET_MODE (dest)); |
681 | } | |
682 | /* Oh well, we're out of luck. */ | |
683 | else | |
684 | breg = NULL; | |
685 | ||
686 | /* We couldn't figure out the value stored in REG, so reset all | |
687 | of its pending debug uses. */ | |
688 | if (!breg) | |
689 | { | |
690 | dead_debug_reset_uses (debug, uses); | |
691 | return 0; | |
692 | } | |
693 | } | |
694 | ||
695 | /* If there's a single (debug) use of an otherwise unused REG, and | |
696 | the debug use is not part of a larger expression, then it | |
697 | probably doesn't make sense to introduce a new debug temp. */ | |
698 | if (where == DEBUG_TEMP_AFTER_WITH_REG && !uses->next) | |
699 | { | |
700 | rtx next = DF_REF_INSN (uses->use); | |
701 | ||
702 | if (DEBUG_INSN_P (next) && reg == INSN_VAR_LOCATION_LOC (next)) | |
703 | { | |
704 | XDELETE (uses); | |
705 | return 0; | |
706 | } | |
707 | } | |
708 | ||
e9f950ba AO |
709 | if (!global) |
710 | /* Create DEBUG_EXPR (and DEBUG_EXPR_DECL). */ | |
711 | dval = make_debug_expr_from_rtl (reg); | |
08df6c0d AO |
712 | |
713 | /* Emit a debug bind insn before the insn in which reg dies. */ | |
714 | bind = gen_rtx_VAR_LOCATION (GET_MODE (reg), | |
715 | DEBUG_EXPR_TREE_DECL (dval), breg, | |
716 | VAR_INIT_STATUS_INITIALIZED); | |
717 | ||
85d87497 JJ |
718 | if (where == DEBUG_TEMP_AFTER_WITH_REG |
719 | || where == DEBUG_TEMP_AFTER_WITH_REG_FORCE) | |
08df6c0d AO |
720 | bind = emit_debug_insn_after (bind, insn); |
721 | else | |
722 | bind = emit_debug_insn_before (bind, insn); | |
36290bb4 AO |
723 | if (debug->to_rescan == NULL) |
724 | debug->to_rescan = BITMAP_ALLOC (NULL); | |
725 | bitmap_set_bit (debug->to_rescan, INSN_UID (bind)); | |
08df6c0d AO |
726 | |
727 | /* Adjust all uses. */ | |
728 | while ((cur = uses)) | |
729 | { | |
730 | if (GET_MODE (*DF_REF_REAL_LOC (cur->use)) == GET_MODE (reg)) | |
731 | *DF_REF_REAL_LOC (cur->use) = dval; | |
732 | else | |
733 | *DF_REF_REAL_LOC (cur->use) | |
734 | = gen_lowpart_SUBREG (GET_MODE (*DF_REF_REAL_LOC (cur->use)), dval); | |
735 | /* ??? Should we simplify subreg of subreg? */ | |
08df6c0d AO |
736 | bitmap_set_bit (debug->to_rescan, INSN_UID (DF_REF_INSN (cur->use))); |
737 | uses = cur->next; | |
738 | XDELETE (cur); | |
739 | } | |
740 | ||
741 | return 1; | |
742 | } |