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e6637753 | 1 | /* Infrastructure for tracking user variable locations and values |
2 | throughout compilation. | |
d353bf18 | 3 | Copyright (C) 2010-2015 Free Software Foundation, Inc. |
e6637753 | 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" | |
9ef16211 | 25 | #include "backend.h" |
e6637753 | 26 | #include "rtl.h" |
9ef16211 | 27 | #include "df.h" |
e6637753 | 28 | #include "valtrack.h" |
e6637753 | 29 | #include "regs.h" |
30 | #include "emit-rtl.h" | |
31 | ||
598006de | 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 | |
3754d046 | 37 | gen_lowpart_for_debug (machine_mode mode, rtx x) |
598006de | 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 | ||
e6637753 | 50 | /* Replace auto-increment addressing modes with explicit operations to access |
51 | the same addresses without modifying the corresponding registers. */ | |
52 | ||
e6637753 | 53 | static rtx |
3754d046 | 54 | cleanup_auto_inc_dec (rtx src, machine_mode mem_mode ATTRIBUTE_UNUSED) |
e6637753 | 55 | { |
56 | rtx x = src; | |
490c6d6d | 57 | #ifdef AUTO_INC_DEC |
e6637753 | 58 | const RTX_CODE code = GET_CODE (x); |
59 | int i; | |
60 | const char *fmt; | |
61 | ||
62 | switch (code) | |
63 | { | |
64 | case REG: | |
0349edce | 65 | CASE_CONST_ANY: |
e6637753 | 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: | |
b291008a | 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))) | |
e6637753 | 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), | |
c338f2e3 | 96 | gen_int_mode (code == PRE_INC |
97 | ? GET_MODE_SIZE (mem_mode) | |
98 | : -GET_MODE_SIZE (mem_mode), | |
99 | GET_MODE (x))); | |
e6637753 | 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 | ||
490c6d6d | 140 | #else /* !AUTO_INC_DEC */ |
141 | x = copy_rtx (x); | |
142 | #endif /* !AUTO_INC_DEC */ | |
143 | ||
e6637753 | 144 | return x; |
145 | } | |
e6637753 | 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; | |
e6637753 | 168 | pair->to = cleanup_auto_inc_dec (pair->to, VOIDmode); |
e6637753 | 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 | |
4cd001d5 | 180 | propagate_for_debug (rtx_insn *insn, rtx_insn *last, rtx dest, rtx src, |
e6637753 | 181 | basic_block this_basic_block) |
182 | { | |
e149ca56 | 183 | rtx_insn *next, *end = NEXT_INSN (BB_END (this_basic_block)); |
184 | rtx loc; | |
3754d046 | 185 | rtx (*saved_rtl_hook_no_emit) (machine_mode, rtx); |
e6637753 | 186 | |
187 | struct rtx_subst_pair p; | |
188 | p.to = src; | |
189 | p.adjusted = false; | |
190 | ||
191 | next = NEXT_INSN (insn); | |
192 | last = NEXT_INSN (last); | |
598006de | 193 | saved_rtl_hook_no_emit = rtl_hooks.gen_lowpart_no_emit; |
194 | rtl_hooks.gen_lowpart_no_emit = gen_lowpart_for_debug; | |
e6637753 | 195 | while (next != last && next != end) |
196 | { | |
197 | insn = next; | |
198 | next = NEXT_INSN (insn); | |
199 | if (DEBUG_INSN_P (insn)) | |
200 | { | |
201 | loc = simplify_replace_fn_rtx (INSN_VAR_LOCATION_LOC (insn), | |
202 | dest, propagate_for_debug_subst, &p); | |
203 | if (loc == INSN_VAR_LOCATION_LOC (insn)) | |
204 | continue; | |
205 | INSN_VAR_LOCATION_LOC (insn) = loc; | |
206 | df_insn_rescan (insn); | |
207 | } | |
208 | } | |
598006de | 209 | rtl_hooks.gen_lowpart_no_emit = saved_rtl_hook_no_emit; |
e6637753 | 210 | } |
211 | ||
212 | /* Initialize DEBUG to an empty list, and clear USED, if given. */ | |
dcd028e1 | 213 | |
214 | void | |
215 | dead_debug_global_init (struct dead_debug_global *debug, bitmap used) | |
216 | { | |
217 | debug->used = used; | |
c1f445d2 | 218 | debug->htab = NULL; |
dcd028e1 | 219 | if (used) |
220 | bitmap_clear (used); | |
221 | } | |
222 | ||
223 | /* Initialize DEBUG to an empty list, and clear USED, if given. Link | |
224 | back to GLOBAL, if given, and bring in used bits from it. */ | |
225 | ||
e6637753 | 226 | void |
dcd028e1 | 227 | dead_debug_local_init (struct dead_debug_local *debug, bitmap used, |
228 | struct dead_debug_global *global) | |
e6637753 | 229 | { |
dcd028e1 | 230 | if (!used && global && global->used) |
231 | used = BITMAP_ALLOC (NULL); | |
232 | ||
e6637753 | 233 | debug->head = NULL; |
dcd028e1 | 234 | debug->global = global; |
e6637753 | 235 | debug->used = used; |
236 | debug->to_rescan = NULL; | |
dcd028e1 | 237 | |
e6637753 | 238 | if (used) |
dcd028e1 | 239 | { |
240 | if (global && global->used) | |
241 | bitmap_copy (used, global->used); | |
242 | else | |
243 | bitmap_clear (used); | |
244 | } | |
245 | } | |
246 | ||
247 | /* Locate the entry for REG in GLOBAL->htab. */ | |
248 | ||
249 | static dead_debug_global_entry * | |
250 | dead_debug_global_find (struct dead_debug_global *global, rtx reg) | |
251 | { | |
252 | dead_debug_global_entry temp_entry; | |
253 | temp_entry.reg = reg; | |
254 | ||
c1f445d2 | 255 | dead_debug_global_entry *entry = global->htab->find (&temp_entry); |
dcd028e1 | 256 | gcc_checking_assert (entry && entry->reg == temp_entry.reg); |
dcd028e1 | 257 | |
258 | return entry; | |
259 | } | |
260 | ||
261 | /* Insert an entry mapping REG to DTEMP in GLOBAL->htab. */ | |
262 | ||
92a66fbd | 263 | static dead_debug_global_entry * |
dcd028e1 | 264 | dead_debug_global_insert (struct dead_debug_global *global, rtx reg, rtx dtemp) |
265 | { | |
266 | dead_debug_global_entry temp_entry; | |
267 | temp_entry.reg = reg; | |
268 | temp_entry.dtemp = dtemp; | |
269 | ||
c1f445d2 | 270 | if (!global->htab) |
271 | global->htab = new hash_table<dead_debug_hash_descr> (31); | |
dcd028e1 | 272 | |
c1f445d2 | 273 | dead_debug_global_entry **slot = global->htab->find_slot (&temp_entry, |
274 | INSERT); | |
dcd028e1 | 275 | gcc_checking_assert (!*slot); |
276 | *slot = XNEW (dead_debug_global_entry); | |
277 | **slot = temp_entry; | |
92a66fbd | 278 | return *slot; |
dcd028e1 | 279 | } |
280 | ||
281 | /* If UREGNO, referenced by USE, is a pseudo marked as used in GLOBAL, | |
282 | replace it with with a USE of the debug temp recorded for it, and | |
283 | return TRUE. Otherwise, just return FALSE. | |
284 | ||
285 | If PTO_RESCAN is given, instead of rescanning modified INSNs right | |
286 | away, add their UIDs to the bitmap, allocating one of *PTO_RESCAN | |
287 | is NULL. */ | |
288 | ||
289 | static bool | |
290 | dead_debug_global_replace_temp (struct dead_debug_global *global, | |
291 | df_ref use, unsigned int uregno, | |
292 | bitmap *pto_rescan) | |
293 | { | |
294 | if (!global || uregno < FIRST_PSEUDO_REGISTER | |
295 | || !global->used | |
92a66fbd | 296 | || !REG_P (*DF_REF_REAL_LOC (use)) |
297 | || REGNO (*DF_REF_REAL_LOC (use)) != uregno | |
dcd028e1 | 298 | || !bitmap_bit_p (global->used, uregno)) |
299 | return false; | |
300 | ||
dcd028e1 | 301 | dead_debug_global_entry *entry |
302 | = dead_debug_global_find (global, *DF_REF_REAL_LOC (use)); | |
303 | gcc_checking_assert (GET_CODE (entry->reg) == REG | |
304 | && REGNO (entry->reg) == uregno); | |
305 | ||
92a66fbd | 306 | if (!entry->dtemp) |
307 | return true; | |
308 | ||
dcd028e1 | 309 | *DF_REF_REAL_LOC (use) = entry->dtemp; |
310 | if (!pto_rescan) | |
311 | df_insn_rescan (DF_REF_INSN (use)); | |
312 | else | |
313 | { | |
314 | if (!*pto_rescan) | |
315 | *pto_rescan = BITMAP_ALLOC (NULL); | |
316 | bitmap_set_bit (*pto_rescan, INSN_UID (DF_REF_INSN (use))); | |
317 | } | |
318 | ||
319 | return true; | |
e6637753 | 320 | } |
321 | ||
322 | /* Reset all debug uses in HEAD, and clear DEBUG->to_rescan bits of | |
323 | each reset insn. DEBUG is not otherwise modified. If HEAD is | |
324 | DEBUG->head, DEBUG->head will be set to NULL at the end. | |
325 | Otherwise, entries from DEBUG->head that pertain to reset insns | |
326 | will be removed, and only then rescanned. */ | |
327 | ||
328 | static void | |
dcd028e1 | 329 | dead_debug_reset_uses (struct dead_debug_local *debug, |
330 | struct dead_debug_use *head) | |
e6637753 | 331 | { |
332 | bool got_head = (debug->head == head); | |
333 | bitmap rescan; | |
334 | struct dead_debug_use **tailp = &debug->head; | |
335 | struct dead_debug_use *cur; | |
336 | bitmap_iterator bi; | |
337 | unsigned int uid; | |
338 | ||
339 | if (got_head) | |
340 | rescan = NULL; | |
341 | else | |
342 | rescan = BITMAP_ALLOC (NULL); | |
343 | ||
344 | while (head) | |
345 | { | |
346 | struct dead_debug_use *next = head->next; | |
d4a27d0f | 347 | rtx_insn *insn; |
e6637753 | 348 | |
349 | insn = DF_REF_INSN (head->use); | |
350 | if (!next || DF_REF_INSN (next->use) != insn) | |
351 | { | |
352 | INSN_VAR_LOCATION_LOC (insn) = gen_rtx_UNKNOWN_VAR_LOC (); | |
353 | if (got_head) | |
354 | df_insn_rescan_debug_internal (insn); | |
355 | else | |
356 | bitmap_set_bit (rescan, INSN_UID (insn)); | |
357 | if (debug->to_rescan) | |
358 | bitmap_clear_bit (debug->to_rescan, INSN_UID (insn)); | |
359 | } | |
360 | XDELETE (head); | |
361 | head = next; | |
362 | } | |
363 | ||
364 | if (got_head) | |
365 | { | |
366 | debug->head = NULL; | |
367 | return; | |
368 | } | |
369 | ||
370 | while ((cur = *tailp)) | |
371 | if (bitmap_bit_p (rescan, INSN_UID (DF_REF_INSN (cur->use)))) | |
372 | { | |
373 | *tailp = cur->next; | |
374 | XDELETE (cur); | |
375 | } | |
376 | else | |
377 | tailp = &cur->next; | |
378 | ||
379 | EXECUTE_IF_SET_IN_BITMAP (rescan, 0, uid, bi) | |
380 | { | |
381 | struct df_insn_info *insn_info = DF_INSN_UID_SAFE_GET (uid); | |
382 | if (insn_info) | |
383 | df_insn_rescan_debug_internal (insn_info->insn); | |
384 | } | |
385 | ||
386 | BITMAP_FREE (rescan); | |
387 | } | |
388 | ||
dcd028e1 | 389 | /* Promote pending local uses of pseudos in DEBUG to global |
390 | substitutions. Uses of non-pseudos are left alone for | |
391 | resetting. */ | |
392 | ||
393 | static void | |
394 | dead_debug_promote_uses (struct dead_debug_local *debug) | |
395 | { | |
396 | for (struct dead_debug_use *head = debug->head, **headp = &debug->head; | |
397 | head; head = *headp) | |
398 | { | |
399 | rtx reg = *DF_REF_REAL_LOC (head->use); | |
92a66fbd | 400 | df_ref ref; |
401 | dead_debug_global_entry *entry; | |
dcd028e1 | 402 | |
403 | if (GET_CODE (reg) != REG | |
404 | || REGNO (reg) < FIRST_PSEUDO_REGISTER) | |
405 | { | |
406 | headp = &head->next; | |
407 | continue; | |
408 | } | |
409 | ||
410 | if (!debug->global->used) | |
411 | debug->global->used = BITMAP_ALLOC (NULL); | |
412 | ||
9adb58d7 | 413 | bool added = bitmap_set_bit (debug->global->used, REGNO (reg)); |
414 | gcc_checking_assert (added); | |
415 | ||
416 | entry = dead_debug_global_insert (debug->global, reg, | |
417 | make_debug_expr_from_rtl (reg)); | |
dcd028e1 | 418 | |
92a66fbd | 419 | gcc_checking_assert (entry->dtemp); |
420 | ||
421 | /* Tentatively remove the USE from the list. */ | |
dcd028e1 | 422 | *headp = head->next; |
92a66fbd | 423 | |
424 | if (!debug->to_rescan) | |
425 | debug->to_rescan = BITMAP_ALLOC (NULL); | |
426 | ||
427 | for (ref = DF_REG_USE_CHAIN (REGNO (reg)); ref; | |
428 | ref = DF_REF_NEXT_REG (ref)) | |
429 | if (DEBUG_INSN_P (DF_REF_INSN (ref))) | |
430 | { | |
431 | if (!dead_debug_global_replace_temp (debug->global, ref, | |
432 | REGNO (reg), | |
433 | &debug->to_rescan)) | |
434 | { | |
d4a27d0f | 435 | rtx_insn *insn = DF_REF_INSN (ref); |
92a66fbd | 436 | INSN_VAR_LOCATION_LOC (insn) = gen_rtx_UNKNOWN_VAR_LOC (); |
437 | bitmap_set_bit (debug->to_rescan, INSN_UID (insn)); | |
438 | } | |
439 | } | |
440 | ||
441 | for (ref = DF_REG_DEF_CHAIN (REGNO (reg)); ref; | |
442 | ref = DF_REF_NEXT_REG (ref)) | |
443 | if (!dead_debug_insert_temp (debug, REGNO (reg), DF_REF_INSN (ref), | |
444 | DEBUG_TEMP_BEFORE_WITH_VALUE)) | |
445 | { | |
446 | rtx bind; | |
447 | bind = gen_rtx_VAR_LOCATION (GET_MODE (reg), | |
448 | DEBUG_EXPR_TREE_DECL (entry->dtemp), | |
449 | gen_rtx_UNKNOWN_VAR_LOC (), | |
450 | VAR_INIT_STATUS_INITIALIZED); | |
d4a27d0f | 451 | rtx_insn *insn = emit_debug_insn_before (bind, DF_REF_INSN (ref)); |
92a66fbd | 452 | bitmap_set_bit (debug->to_rescan, INSN_UID (insn)); |
453 | } | |
454 | ||
455 | entry->dtemp = NULL; | |
dcd028e1 | 456 | XDELETE (head); |
457 | } | |
458 | } | |
459 | ||
e6637753 | 460 | /* Reset all debug insns with pending uses. Release the bitmap in it, |
461 | unless it is USED. USED must be the same bitmap passed to | |
dcd028e1 | 462 | dead_debug_local_init. */ |
463 | ||
e6637753 | 464 | void |
dcd028e1 | 465 | dead_debug_local_finish (struct dead_debug_local *debug, bitmap used) |
e6637753 | 466 | { |
dcd028e1 | 467 | if (debug->global) |
468 | dead_debug_promote_uses (debug); | |
469 | ||
92a66fbd | 470 | if (debug->used != used) |
471 | BITMAP_FREE (debug->used); | |
472 | ||
e6637753 | 473 | dead_debug_reset_uses (debug, debug->head); |
474 | ||
475 | if (debug->to_rescan) | |
476 | { | |
477 | bitmap_iterator bi; | |
478 | unsigned int uid; | |
479 | ||
480 | EXECUTE_IF_SET_IN_BITMAP (debug->to_rescan, 0, uid, bi) | |
481 | { | |
482 | struct df_insn_info *insn_info = DF_INSN_UID_SAFE_GET (uid); | |
483 | if (insn_info) | |
484 | df_insn_rescan (insn_info->insn); | |
485 | } | |
486 | BITMAP_FREE (debug->to_rescan); | |
487 | } | |
488 | } | |
489 | ||
dcd028e1 | 490 | /* Release GLOBAL->used unless it is the same as USED. Release the |
491 | mapping hash table if it was initialized. */ | |
492 | ||
493 | void | |
494 | dead_debug_global_finish (struct dead_debug_global *global, bitmap used) | |
495 | { | |
496 | if (global->used != used) | |
497 | BITMAP_FREE (global->used); | |
498 | ||
c1f445d2 | 499 | delete global->htab; |
500 | global->htab = NULL; | |
dcd028e1 | 501 | } |
502 | ||
503 | /* Add USE to DEBUG, or substitute it right away if it's a pseudo in | |
504 | the global substitution list. USE must be a dead reference to | |
505 | UREGNO in a debug insn. Create a bitmap for DEBUG as needed. */ | |
506 | ||
e6637753 | 507 | void |
dcd028e1 | 508 | dead_debug_add (struct dead_debug_local *debug, df_ref use, unsigned int uregno) |
e6637753 | 509 | { |
dcd028e1 | 510 | if (dead_debug_global_replace_temp (debug->global, use, uregno, |
511 | &debug->to_rescan)) | |
512 | return; | |
513 | ||
e6637753 | 514 | struct dead_debug_use *newddu = XNEW (struct dead_debug_use); |
515 | ||
516 | newddu->use = use; | |
517 | newddu->next = debug->head; | |
518 | debug->head = newddu; | |
519 | ||
520 | if (!debug->used) | |
521 | debug->used = BITMAP_ALLOC (NULL); | |
522 | ||
523 | /* ??? If we dealt with split multi-registers below, we should set | |
524 | all registers for the used mode in case of hardware | |
525 | registers. */ | |
526 | bitmap_set_bit (debug->used, uregno); | |
527 | } | |
528 | ||
596f7cca | 529 | /* Like lowpart_subreg, but if a subreg is not valid for machine, force |
530 | it anyway - for use in debug insns. */ | |
531 | ||
532 | static rtx | |
533 | debug_lowpart_subreg (machine_mode outer_mode, rtx expr, | |
534 | machine_mode inner_mode) | |
535 | { | |
536 | if (inner_mode == VOIDmode) | |
537 | inner_mode = GET_MODE (expr); | |
538 | int offset = subreg_lowpart_offset (outer_mode, inner_mode); | |
539 | rtx ret = simplify_gen_subreg (outer_mode, expr, inner_mode, offset); | |
540 | if (ret) | |
541 | return ret; | |
542 | return gen_rtx_raw_SUBREG (outer_mode, expr, offset); | |
543 | } | |
544 | ||
e6637753 | 545 | /* If UREGNO is referenced by any entry in DEBUG, emit a debug insn |
dcd028e1 | 546 | before or after INSN (depending on WHERE), that binds a (possibly |
547 | global) debug temp to the widest-mode use of UREGNO, if WHERE is | |
548 | *_WITH_REG, or the value stored in UREGNO by INSN otherwise, and | |
549 | replace all uses of UREGNO in DEBUG with uses of the debug temp. | |
550 | INSN must be where UREGNO dies, if WHERE is *_BEFORE_*, or where it | |
551 | is set otherwise. Return the number of debug insns emitted. */ | |
552 | ||
e6637753 | 553 | int |
dcd028e1 | 554 | dead_debug_insert_temp (struct dead_debug_local *debug, unsigned int uregno, |
25bf5e12 | 555 | rtx_insn *insn, enum debug_temp_where where) |
e6637753 | 556 | { |
557 | struct dead_debug_use **tailp = &debug->head; | |
558 | struct dead_debug_use *cur; | |
559 | struct dead_debug_use *uses = NULL; | |
560 | struct dead_debug_use **usesp = &uses; | |
dcd028e1 | 561 | rtx reg = NULL_RTX; |
e6637753 | 562 | rtx breg; |
dcd028e1 | 563 | rtx dval = NULL_RTX; |
e6637753 | 564 | rtx bind; |
dcd028e1 | 565 | bool global; |
e6637753 | 566 | |
dcd028e1 | 567 | if (!debug->used) |
568 | return 0; | |
569 | ||
570 | global = (debug->global && debug->global->used | |
571 | && bitmap_bit_p (debug->global->used, uregno)); | |
572 | ||
573 | if (!global && !bitmap_clear_bit (debug->used, uregno)) | |
e6637753 | 574 | return 0; |
575 | ||
576 | /* Move all uses of uregno from debug->head to uses, setting mode to | |
577 | the widest referenced mode. */ | |
578 | while ((cur = *tailp)) | |
579 | { | |
580 | if (DF_REF_REGNO (cur->use) == uregno) | |
581 | { | |
c41441bb | 582 | /* If this loc has been changed e.g. to debug_expr already |
583 | as part of a multi-register use, just drop it. */ | |
584 | if (!REG_P (*DF_REF_REAL_LOC (cur->use))) | |
585 | { | |
586 | *tailp = cur->next; | |
587 | XDELETE (cur); | |
588 | continue; | |
589 | } | |
e6637753 | 590 | *usesp = cur; |
591 | usesp = &cur->next; | |
592 | *tailp = cur->next; | |
593 | cur->next = NULL; | |
594 | if (!reg | |
595 | || (GET_MODE_BITSIZE (GET_MODE (reg)) | |
596 | < GET_MODE_BITSIZE (GET_MODE (*DF_REF_REAL_LOC (cur->use))))) | |
597 | reg = *DF_REF_REAL_LOC (cur->use); | |
598 | } | |
599 | else | |
600 | tailp = &(*tailp)->next; | |
601 | } | |
602 | ||
603 | /* We may have dangling bits in debug->used for registers that were part | |
604 | of a multi-register use, one component of which has been reset. */ | |
605 | if (reg == NULL) | |
606 | { | |
607 | gcc_checking_assert (!uses); | |
dcd028e1 | 608 | if (!global) |
609 | return 0; | |
610 | } | |
611 | ||
612 | if (global) | |
613 | { | |
614 | if (!reg) | |
615 | reg = regno_reg_rtx[uregno]; | |
616 | dead_debug_global_entry *entry | |
617 | = dead_debug_global_find (debug->global, reg); | |
618 | gcc_checking_assert (entry->reg == reg); | |
619 | dval = entry->dtemp; | |
92a66fbd | 620 | if (!dval) |
621 | return 0; | |
e6637753 | 622 | } |
623 | ||
dcd028e1 | 624 | gcc_checking_assert (uses || global); |
e6637753 | 625 | |
626 | breg = reg; | |
627 | /* Recover the expression INSN stores in REG. */ | |
628 | if (where == DEBUG_TEMP_BEFORE_WITH_VALUE) | |
629 | { | |
630 | rtx set = single_set (insn); | |
631 | rtx dest, src; | |
632 | ||
633 | if (set) | |
634 | { | |
635 | dest = SET_DEST (set); | |
636 | src = SET_SRC (set); | |
637 | /* Lose if the REG-setting insn is a CALL. */ | |
638 | if (GET_CODE (src) == CALL) | |
639 | { | |
640 | while (uses) | |
641 | { | |
642 | cur = uses->next; | |
643 | XDELETE (uses); | |
644 | uses = cur; | |
645 | } | |
646 | return 0; | |
647 | } | |
648 | } | |
649 | ||
650 | /* ??? Should we try to extract it from a PARALLEL? */ | |
651 | if (!set) | |
652 | breg = NULL; | |
653 | /* Cool, it's the same REG, we can use SRC. */ | |
654 | else if (dest == reg) | |
26f0a6e0 | 655 | breg = cleanup_auto_inc_dec (src, VOIDmode); |
e6637753 | 656 | else if (REG_P (dest)) |
657 | { | |
658 | /* Hmm... Something's fishy, we should be setting REG here. */ | |
659 | if (REGNO (dest) != REGNO (reg)) | |
660 | breg = NULL; | |
661 | /* If we're not overwriting all the hardware registers that | |
662 | setting REG in its mode would, we won't know what to bind | |
663 | the debug temp to. ??? We could bind the debug_expr to a | |
664 | CONCAT or PARALLEL with the split multi-registers, and | |
665 | replace them as we found the corresponding sets. */ | |
0933f1d9 | 666 | else if (REG_NREGS (reg) != REG_NREGS (dest)) |
e6637753 | 667 | breg = NULL; |
668 | /* Ok, it's the same (hardware) REG, but with a different | |
669 | mode, so SUBREG it. */ | |
670 | else | |
596f7cca | 671 | breg = debug_lowpart_subreg (GET_MODE (reg), |
672 | cleanup_auto_inc_dec (src, VOIDmode), | |
673 | GET_MODE (dest)); | |
e6637753 | 674 | } |
675 | else if (GET_CODE (dest) == SUBREG) | |
676 | { | |
677 | /* We should be setting REG here. Lose. */ | |
678 | if (REGNO (SUBREG_REG (dest)) != REGNO (reg)) | |
679 | breg = NULL; | |
680 | /* Lose if we're setting something other than the lowpart of | |
681 | REG. */ | |
682 | else if (!subreg_lowpart_p (dest)) | |
683 | breg = NULL; | |
684 | /* If we're not overwriting all the hardware registers that | |
685 | setting REG in its mode would, we won't know what to bind | |
686 | the debug temp to. */ | |
687 | else if (REGNO (reg) < FIRST_PSEUDO_REGISTER | |
0933f1d9 | 688 | && (REG_NREGS (reg) |
e6637753 | 689 | != hard_regno_nregs[REGNO (reg)][GET_MODE (dest)])) |
690 | breg = NULL; | |
691 | /* Yay, we can use SRC, just adjust its mode. */ | |
692 | else | |
596f7cca | 693 | breg = debug_lowpart_subreg (GET_MODE (reg), |
694 | cleanup_auto_inc_dec (src, VOIDmode), | |
695 | GET_MODE (dest)); | |
e6637753 | 696 | } |
697 | /* Oh well, we're out of luck. */ | |
698 | else | |
699 | breg = NULL; | |
700 | ||
701 | /* We couldn't figure out the value stored in REG, so reset all | |
702 | of its pending debug uses. */ | |
703 | if (!breg) | |
704 | { | |
705 | dead_debug_reset_uses (debug, uses); | |
706 | return 0; | |
707 | } | |
708 | } | |
709 | ||
710 | /* If there's a single (debug) use of an otherwise unused REG, and | |
711 | the debug use is not part of a larger expression, then it | |
712 | probably doesn't make sense to introduce a new debug temp. */ | |
713 | if (where == DEBUG_TEMP_AFTER_WITH_REG && !uses->next) | |
714 | { | |
d4a27d0f | 715 | rtx_insn *next = DF_REF_INSN (uses->use); |
e6637753 | 716 | |
717 | if (DEBUG_INSN_P (next) && reg == INSN_VAR_LOCATION_LOC (next)) | |
718 | { | |
719 | XDELETE (uses); | |
720 | return 0; | |
721 | } | |
722 | } | |
723 | ||
dcd028e1 | 724 | if (!global) |
725 | /* Create DEBUG_EXPR (and DEBUG_EXPR_DECL). */ | |
726 | dval = make_debug_expr_from_rtl (reg); | |
e6637753 | 727 | |
728 | /* Emit a debug bind insn before the insn in which reg dies. */ | |
729 | bind = gen_rtx_VAR_LOCATION (GET_MODE (reg), | |
730 | DEBUG_EXPR_TREE_DECL (dval), breg, | |
731 | VAR_INIT_STATUS_INITIALIZED); | |
732 | ||
6baa953c | 733 | if (where == DEBUG_TEMP_AFTER_WITH_REG |
734 | || where == DEBUG_TEMP_AFTER_WITH_REG_FORCE) | |
e6637753 | 735 | bind = emit_debug_insn_after (bind, insn); |
736 | else | |
737 | bind = emit_debug_insn_before (bind, insn); | |
9ee27052 | 738 | if (debug->to_rescan == NULL) |
739 | debug->to_rescan = BITMAP_ALLOC (NULL); | |
740 | bitmap_set_bit (debug->to_rescan, INSN_UID (bind)); | |
e6637753 | 741 | |
742 | /* Adjust all uses. */ | |
743 | while ((cur = uses)) | |
744 | { | |
745 | if (GET_MODE (*DF_REF_REAL_LOC (cur->use)) == GET_MODE (reg)) | |
746 | *DF_REF_REAL_LOC (cur->use) = dval; | |
747 | else | |
748 | *DF_REF_REAL_LOC (cur->use) | |
596f7cca | 749 | = debug_lowpart_subreg (GET_MODE (*DF_REF_REAL_LOC (cur->use)), dval, |
750 | GET_MODE (dval)); | |
e6637753 | 751 | /* ??? Should we simplify subreg of subreg? */ |
e6637753 | 752 | bitmap_set_bit (debug->to_rescan, INSN_UID (DF_REF_INSN (cur->use))); |
753 | uses = cur->next; | |
754 | XDELETE (cur); | |
755 | } | |
756 | ||
757 | return 1; | |
758 | } |