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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" | |
25 | #include "tm.h" | |
26 | #include "rtl.h" | |
94ea8568 | 27 | #include "predict.h" |
28 | #include "basic-block.h" | |
e6637753 | 29 | #include "valtrack.h" |
a3020f2f | 30 | #include "hashtab.h" |
31 | #include "hash-set.h" | |
32 | #include "vec.h" | |
a3020f2f | 33 | #include "hard-reg-set.h" |
34 | #include "input.h" | |
e6637753 | 35 | #include "function.h" |
36 | #include "regs.h" | |
37 | #include "emit-rtl.h" | |
38 | ||
598006de | 39 | /* gen_lowpart_no_emit hook implementation for DEBUG_INSNs. In DEBUG_INSNs, |
40 | all lowpart SUBREGs are valid, despite what the machine requires for | |
41 | instructions. */ | |
42 | ||
43 | static rtx | |
3754d046 | 44 | gen_lowpart_for_debug (machine_mode mode, rtx x) |
598006de | 45 | { |
46 | rtx result = gen_lowpart_if_possible (mode, x); | |
47 | if (result) | |
48 | return result; | |
49 | ||
50 | if (GET_MODE (x) != VOIDmode) | |
51 | return gen_rtx_raw_SUBREG (mode, x, | |
52 | subreg_lowpart_offset (mode, GET_MODE (x))); | |
53 | ||
54 | return NULL_RTX; | |
55 | } | |
56 | ||
e6637753 | 57 | /* Replace auto-increment addressing modes with explicit operations to access |
58 | the same addresses without modifying the corresponding registers. */ | |
59 | ||
e6637753 | 60 | static rtx |
3754d046 | 61 | cleanup_auto_inc_dec (rtx src, machine_mode mem_mode ATTRIBUTE_UNUSED) |
e6637753 | 62 | { |
63 | rtx x = src; | |
490c6d6d | 64 | #ifdef AUTO_INC_DEC |
e6637753 | 65 | const RTX_CODE code = GET_CODE (x); |
66 | int i; | |
67 | const char *fmt; | |
68 | ||
69 | switch (code) | |
70 | { | |
71 | case REG: | |
0349edce | 72 | CASE_CONST_ANY: |
e6637753 | 73 | case SYMBOL_REF: |
74 | case CODE_LABEL: | |
75 | case PC: | |
76 | case CC0: | |
77 | case SCRATCH: | |
78 | /* SCRATCH must be shared because they represent distinct values. */ | |
79 | return x; | |
80 | case CLOBBER: | |
b291008a | 81 | /* Share clobbers of hard registers (like cc0), but do not share pseudo reg |
82 | clobbers or clobbers of hard registers that originated as pseudos. | |
83 | This is needed to allow safe register renaming. */ | |
84 | if (REG_P (XEXP (x, 0)) && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER | |
85 | && ORIGINAL_REGNO (XEXP (x, 0)) == REGNO (XEXP (x, 0))) | |
e6637753 | 86 | return x; |
87 | break; | |
88 | ||
89 | case CONST: | |
90 | if (shared_const_p (x)) | |
91 | return x; | |
92 | break; | |
93 | ||
94 | case MEM: | |
95 | mem_mode = GET_MODE (x); | |
96 | break; | |
97 | ||
98 | case PRE_INC: | |
99 | case PRE_DEC: | |
100 | gcc_assert (mem_mode != VOIDmode && mem_mode != BLKmode); | |
101 | return gen_rtx_PLUS (GET_MODE (x), | |
102 | cleanup_auto_inc_dec (XEXP (x, 0), mem_mode), | |
c338f2e3 | 103 | gen_int_mode (code == PRE_INC |
104 | ? GET_MODE_SIZE (mem_mode) | |
105 | : -GET_MODE_SIZE (mem_mode), | |
106 | GET_MODE (x))); | |
e6637753 | 107 | |
108 | case POST_INC: | |
109 | case POST_DEC: | |
110 | case PRE_MODIFY: | |
111 | case POST_MODIFY: | |
112 | return cleanup_auto_inc_dec (code == PRE_MODIFY | |
113 | ? XEXP (x, 1) : XEXP (x, 0), | |
114 | mem_mode); | |
115 | ||
116 | default: | |
117 | break; | |
118 | } | |
119 | ||
120 | /* Copy the various flags, fields, and other information. We assume | |
121 | that all fields need copying, and then clear the fields that should | |
122 | not be copied. That is the sensible default behavior, and forces | |
123 | us to explicitly document why we are *not* copying a flag. */ | |
124 | x = shallow_copy_rtx (x); | |
125 | ||
126 | /* We do not copy the USED flag, which is used as a mark bit during | |
127 | walks over the RTL. */ | |
128 | RTX_FLAG (x, used) = 0; | |
129 | ||
130 | /* We do not copy FRAME_RELATED for INSNs. */ | |
131 | if (INSN_P (x)) | |
132 | RTX_FLAG (x, frame_related) = 0; | |
133 | ||
134 | fmt = GET_RTX_FORMAT (code); | |
135 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
136 | if (fmt[i] == 'e') | |
137 | XEXP (x, i) = cleanup_auto_inc_dec (XEXP (x, i), mem_mode); | |
138 | else if (fmt[i] == 'E' || fmt[i] == 'V') | |
139 | { | |
140 | int j; | |
141 | XVEC (x, i) = rtvec_alloc (XVECLEN (x, i)); | |
142 | for (j = 0; j < XVECLEN (x, i); j++) | |
143 | XVECEXP (x, i, j) | |
144 | = cleanup_auto_inc_dec (XVECEXP (src, i, j), mem_mode); | |
145 | } | |
146 | ||
490c6d6d | 147 | #else /* !AUTO_INC_DEC */ |
148 | x = copy_rtx (x); | |
149 | #endif /* !AUTO_INC_DEC */ | |
150 | ||
e6637753 | 151 | return x; |
152 | } | |
e6637753 | 153 | |
154 | /* Auxiliary data structure for propagate_for_debug_stmt. */ | |
155 | ||
156 | struct rtx_subst_pair | |
157 | { | |
158 | rtx to; | |
159 | bool adjusted; | |
160 | }; | |
161 | ||
162 | /* DATA points to an rtx_subst_pair. Return the value that should be | |
163 | substituted. */ | |
164 | ||
165 | static rtx | |
166 | propagate_for_debug_subst (rtx from, const_rtx old_rtx, void *data) | |
167 | { | |
168 | struct rtx_subst_pair *pair = (struct rtx_subst_pair *)data; | |
169 | ||
170 | if (!rtx_equal_p (from, old_rtx)) | |
171 | return NULL_RTX; | |
172 | if (!pair->adjusted) | |
173 | { | |
174 | pair->adjusted = true; | |
e6637753 | 175 | pair->to = cleanup_auto_inc_dec (pair->to, VOIDmode); |
e6637753 | 176 | pair->to = make_compound_operation (pair->to, SET); |
177 | return pair->to; | |
178 | } | |
179 | return copy_rtx (pair->to); | |
180 | } | |
181 | ||
182 | /* Replace all the occurrences of DEST with SRC in DEBUG_INSNs between INSN | |
183 | and LAST, not including INSN, but including LAST. Also stop at the end | |
184 | of THIS_BASIC_BLOCK. */ | |
185 | ||
186 | void | |
4cd001d5 | 187 | propagate_for_debug (rtx_insn *insn, rtx_insn *last, rtx dest, rtx src, |
e6637753 | 188 | basic_block this_basic_block) |
189 | { | |
e149ca56 | 190 | rtx_insn *next, *end = NEXT_INSN (BB_END (this_basic_block)); |
191 | rtx loc; | |
3754d046 | 192 | rtx (*saved_rtl_hook_no_emit) (machine_mode, rtx); |
e6637753 | 193 | |
194 | struct rtx_subst_pair p; | |
195 | p.to = src; | |
196 | p.adjusted = false; | |
197 | ||
198 | next = NEXT_INSN (insn); | |
199 | last = NEXT_INSN (last); | |
598006de | 200 | saved_rtl_hook_no_emit = rtl_hooks.gen_lowpart_no_emit; |
201 | rtl_hooks.gen_lowpart_no_emit = gen_lowpart_for_debug; | |
e6637753 | 202 | while (next != last && next != end) |
203 | { | |
204 | insn = next; | |
205 | next = NEXT_INSN (insn); | |
206 | if (DEBUG_INSN_P (insn)) | |
207 | { | |
208 | loc = simplify_replace_fn_rtx (INSN_VAR_LOCATION_LOC (insn), | |
209 | dest, propagate_for_debug_subst, &p); | |
210 | if (loc == INSN_VAR_LOCATION_LOC (insn)) | |
211 | continue; | |
212 | INSN_VAR_LOCATION_LOC (insn) = loc; | |
213 | df_insn_rescan (insn); | |
214 | } | |
215 | } | |
598006de | 216 | rtl_hooks.gen_lowpart_no_emit = saved_rtl_hook_no_emit; |
e6637753 | 217 | } |
218 | ||
219 | /* Initialize DEBUG to an empty list, and clear USED, if given. */ | |
dcd028e1 | 220 | |
221 | void | |
222 | dead_debug_global_init (struct dead_debug_global *debug, bitmap used) | |
223 | { | |
224 | debug->used = used; | |
c1f445d2 | 225 | debug->htab = NULL; |
dcd028e1 | 226 | if (used) |
227 | bitmap_clear (used); | |
228 | } | |
229 | ||
230 | /* Initialize DEBUG to an empty list, and clear USED, if given. Link | |
231 | back to GLOBAL, if given, and bring in used bits from it. */ | |
232 | ||
e6637753 | 233 | void |
dcd028e1 | 234 | dead_debug_local_init (struct dead_debug_local *debug, bitmap used, |
235 | struct dead_debug_global *global) | |
e6637753 | 236 | { |
dcd028e1 | 237 | if (!used && global && global->used) |
238 | used = BITMAP_ALLOC (NULL); | |
239 | ||
e6637753 | 240 | debug->head = NULL; |
dcd028e1 | 241 | debug->global = global; |
e6637753 | 242 | debug->used = used; |
243 | debug->to_rescan = NULL; | |
dcd028e1 | 244 | |
e6637753 | 245 | if (used) |
dcd028e1 | 246 | { |
247 | if (global && global->used) | |
248 | bitmap_copy (used, global->used); | |
249 | else | |
250 | bitmap_clear (used); | |
251 | } | |
252 | } | |
253 | ||
254 | /* Locate the entry for REG in GLOBAL->htab. */ | |
255 | ||
256 | static dead_debug_global_entry * | |
257 | dead_debug_global_find (struct dead_debug_global *global, rtx reg) | |
258 | { | |
259 | dead_debug_global_entry temp_entry; | |
260 | temp_entry.reg = reg; | |
261 | ||
c1f445d2 | 262 | dead_debug_global_entry *entry = global->htab->find (&temp_entry); |
dcd028e1 | 263 | gcc_checking_assert (entry && entry->reg == temp_entry.reg); |
dcd028e1 | 264 | |
265 | return entry; | |
266 | } | |
267 | ||
268 | /* Insert an entry mapping REG to DTEMP in GLOBAL->htab. */ | |
269 | ||
92a66fbd | 270 | static dead_debug_global_entry * |
dcd028e1 | 271 | dead_debug_global_insert (struct dead_debug_global *global, rtx reg, rtx dtemp) |
272 | { | |
273 | dead_debug_global_entry temp_entry; | |
274 | temp_entry.reg = reg; | |
275 | temp_entry.dtemp = dtemp; | |
276 | ||
c1f445d2 | 277 | if (!global->htab) |
278 | global->htab = new hash_table<dead_debug_hash_descr> (31); | |
dcd028e1 | 279 | |
c1f445d2 | 280 | dead_debug_global_entry **slot = global->htab->find_slot (&temp_entry, |
281 | INSERT); | |
dcd028e1 | 282 | gcc_checking_assert (!*slot); |
283 | *slot = XNEW (dead_debug_global_entry); | |
284 | **slot = temp_entry; | |
92a66fbd | 285 | return *slot; |
dcd028e1 | 286 | } |
287 | ||
288 | /* If UREGNO, referenced by USE, is a pseudo marked as used in GLOBAL, | |
289 | replace it with with a USE of the debug temp recorded for it, and | |
290 | return TRUE. Otherwise, just return FALSE. | |
291 | ||
292 | If PTO_RESCAN is given, instead of rescanning modified INSNs right | |
293 | away, add their UIDs to the bitmap, allocating one of *PTO_RESCAN | |
294 | is NULL. */ | |
295 | ||
296 | static bool | |
297 | dead_debug_global_replace_temp (struct dead_debug_global *global, | |
298 | df_ref use, unsigned int uregno, | |
299 | bitmap *pto_rescan) | |
300 | { | |
301 | if (!global || uregno < FIRST_PSEUDO_REGISTER | |
302 | || !global->used | |
92a66fbd | 303 | || !REG_P (*DF_REF_REAL_LOC (use)) |
304 | || REGNO (*DF_REF_REAL_LOC (use)) != uregno | |
dcd028e1 | 305 | || !bitmap_bit_p (global->used, uregno)) |
306 | return false; | |
307 | ||
dcd028e1 | 308 | dead_debug_global_entry *entry |
309 | = dead_debug_global_find (global, *DF_REF_REAL_LOC (use)); | |
310 | gcc_checking_assert (GET_CODE (entry->reg) == REG | |
311 | && REGNO (entry->reg) == uregno); | |
312 | ||
92a66fbd | 313 | if (!entry->dtemp) |
314 | return true; | |
315 | ||
dcd028e1 | 316 | *DF_REF_REAL_LOC (use) = entry->dtemp; |
317 | if (!pto_rescan) | |
318 | df_insn_rescan (DF_REF_INSN (use)); | |
319 | else | |
320 | { | |
321 | if (!*pto_rescan) | |
322 | *pto_rescan = BITMAP_ALLOC (NULL); | |
323 | bitmap_set_bit (*pto_rescan, INSN_UID (DF_REF_INSN (use))); | |
324 | } | |
325 | ||
326 | return true; | |
e6637753 | 327 | } |
328 | ||
329 | /* Reset all debug uses in HEAD, and clear DEBUG->to_rescan bits of | |
330 | each reset insn. DEBUG is not otherwise modified. If HEAD is | |
331 | DEBUG->head, DEBUG->head will be set to NULL at the end. | |
332 | Otherwise, entries from DEBUG->head that pertain to reset insns | |
333 | will be removed, and only then rescanned. */ | |
334 | ||
335 | static void | |
dcd028e1 | 336 | dead_debug_reset_uses (struct dead_debug_local *debug, |
337 | struct dead_debug_use *head) | |
e6637753 | 338 | { |
339 | bool got_head = (debug->head == head); | |
340 | bitmap rescan; | |
341 | struct dead_debug_use **tailp = &debug->head; | |
342 | struct dead_debug_use *cur; | |
343 | bitmap_iterator bi; | |
344 | unsigned int uid; | |
345 | ||
346 | if (got_head) | |
347 | rescan = NULL; | |
348 | else | |
349 | rescan = BITMAP_ALLOC (NULL); | |
350 | ||
351 | while (head) | |
352 | { | |
353 | struct dead_debug_use *next = head->next; | |
d4a27d0f | 354 | rtx_insn *insn; |
e6637753 | 355 | |
356 | insn = DF_REF_INSN (head->use); | |
357 | if (!next || DF_REF_INSN (next->use) != insn) | |
358 | { | |
359 | INSN_VAR_LOCATION_LOC (insn) = gen_rtx_UNKNOWN_VAR_LOC (); | |
360 | if (got_head) | |
361 | df_insn_rescan_debug_internal (insn); | |
362 | else | |
363 | bitmap_set_bit (rescan, INSN_UID (insn)); | |
364 | if (debug->to_rescan) | |
365 | bitmap_clear_bit (debug->to_rescan, INSN_UID (insn)); | |
366 | } | |
367 | XDELETE (head); | |
368 | head = next; | |
369 | } | |
370 | ||
371 | if (got_head) | |
372 | { | |
373 | debug->head = NULL; | |
374 | return; | |
375 | } | |
376 | ||
377 | while ((cur = *tailp)) | |
378 | if (bitmap_bit_p (rescan, INSN_UID (DF_REF_INSN (cur->use)))) | |
379 | { | |
380 | *tailp = cur->next; | |
381 | XDELETE (cur); | |
382 | } | |
383 | else | |
384 | tailp = &cur->next; | |
385 | ||
386 | EXECUTE_IF_SET_IN_BITMAP (rescan, 0, uid, bi) | |
387 | { | |
388 | struct df_insn_info *insn_info = DF_INSN_UID_SAFE_GET (uid); | |
389 | if (insn_info) | |
390 | df_insn_rescan_debug_internal (insn_info->insn); | |
391 | } | |
392 | ||
393 | BITMAP_FREE (rescan); | |
394 | } | |
395 | ||
dcd028e1 | 396 | /* Promote pending local uses of pseudos in DEBUG to global |
397 | substitutions. Uses of non-pseudos are left alone for | |
398 | resetting. */ | |
399 | ||
400 | static void | |
401 | dead_debug_promote_uses (struct dead_debug_local *debug) | |
402 | { | |
403 | for (struct dead_debug_use *head = debug->head, **headp = &debug->head; | |
404 | head; head = *headp) | |
405 | { | |
406 | rtx reg = *DF_REF_REAL_LOC (head->use); | |
92a66fbd | 407 | df_ref ref; |
408 | dead_debug_global_entry *entry; | |
dcd028e1 | 409 | |
410 | if (GET_CODE (reg) != REG | |
411 | || REGNO (reg) < FIRST_PSEUDO_REGISTER) | |
412 | { | |
413 | headp = &head->next; | |
414 | continue; | |
415 | } | |
416 | ||
417 | if (!debug->global->used) | |
418 | debug->global->used = BITMAP_ALLOC (NULL); | |
419 | ||
9adb58d7 | 420 | bool added = bitmap_set_bit (debug->global->used, REGNO (reg)); |
421 | gcc_checking_assert (added); | |
422 | ||
423 | entry = dead_debug_global_insert (debug->global, reg, | |
424 | make_debug_expr_from_rtl (reg)); | |
dcd028e1 | 425 | |
92a66fbd | 426 | gcc_checking_assert (entry->dtemp); |
427 | ||
428 | /* Tentatively remove the USE from the list. */ | |
dcd028e1 | 429 | *headp = head->next; |
92a66fbd | 430 | |
431 | if (!debug->to_rescan) | |
432 | debug->to_rescan = BITMAP_ALLOC (NULL); | |
433 | ||
434 | for (ref = DF_REG_USE_CHAIN (REGNO (reg)); ref; | |
435 | ref = DF_REF_NEXT_REG (ref)) | |
436 | if (DEBUG_INSN_P (DF_REF_INSN (ref))) | |
437 | { | |
438 | if (!dead_debug_global_replace_temp (debug->global, ref, | |
439 | REGNO (reg), | |
440 | &debug->to_rescan)) | |
441 | { | |
d4a27d0f | 442 | rtx_insn *insn = DF_REF_INSN (ref); |
92a66fbd | 443 | INSN_VAR_LOCATION_LOC (insn) = gen_rtx_UNKNOWN_VAR_LOC (); |
444 | bitmap_set_bit (debug->to_rescan, INSN_UID (insn)); | |
445 | } | |
446 | } | |
447 | ||
448 | for (ref = DF_REG_DEF_CHAIN (REGNO (reg)); ref; | |
449 | ref = DF_REF_NEXT_REG (ref)) | |
450 | if (!dead_debug_insert_temp (debug, REGNO (reg), DF_REF_INSN (ref), | |
451 | DEBUG_TEMP_BEFORE_WITH_VALUE)) | |
452 | { | |
453 | rtx bind; | |
454 | bind = gen_rtx_VAR_LOCATION (GET_MODE (reg), | |
455 | DEBUG_EXPR_TREE_DECL (entry->dtemp), | |
456 | gen_rtx_UNKNOWN_VAR_LOC (), | |
457 | VAR_INIT_STATUS_INITIALIZED); | |
d4a27d0f | 458 | rtx_insn *insn = emit_debug_insn_before (bind, DF_REF_INSN (ref)); |
92a66fbd | 459 | bitmap_set_bit (debug->to_rescan, INSN_UID (insn)); |
460 | } | |
461 | ||
462 | entry->dtemp = NULL; | |
dcd028e1 | 463 | XDELETE (head); |
464 | } | |
465 | } | |
466 | ||
e6637753 | 467 | /* Reset all debug insns with pending uses. Release the bitmap in it, |
468 | unless it is USED. USED must be the same bitmap passed to | |
dcd028e1 | 469 | dead_debug_local_init. */ |
470 | ||
e6637753 | 471 | void |
dcd028e1 | 472 | dead_debug_local_finish (struct dead_debug_local *debug, bitmap used) |
e6637753 | 473 | { |
dcd028e1 | 474 | if (debug->global) |
475 | dead_debug_promote_uses (debug); | |
476 | ||
92a66fbd | 477 | if (debug->used != used) |
478 | BITMAP_FREE (debug->used); | |
479 | ||
e6637753 | 480 | dead_debug_reset_uses (debug, debug->head); |
481 | ||
482 | if (debug->to_rescan) | |
483 | { | |
484 | bitmap_iterator bi; | |
485 | unsigned int uid; | |
486 | ||
487 | EXECUTE_IF_SET_IN_BITMAP (debug->to_rescan, 0, uid, bi) | |
488 | { | |
489 | struct df_insn_info *insn_info = DF_INSN_UID_SAFE_GET (uid); | |
490 | if (insn_info) | |
491 | df_insn_rescan (insn_info->insn); | |
492 | } | |
493 | BITMAP_FREE (debug->to_rescan); | |
494 | } | |
495 | } | |
496 | ||
dcd028e1 | 497 | /* Release GLOBAL->used unless it is the same as USED. Release the |
498 | mapping hash table if it was initialized. */ | |
499 | ||
500 | void | |
501 | dead_debug_global_finish (struct dead_debug_global *global, bitmap used) | |
502 | { | |
503 | if (global->used != used) | |
504 | BITMAP_FREE (global->used); | |
505 | ||
c1f445d2 | 506 | delete global->htab; |
507 | global->htab = NULL; | |
dcd028e1 | 508 | } |
509 | ||
510 | /* Add USE to DEBUG, or substitute it right away if it's a pseudo in | |
511 | the global substitution list. USE must be a dead reference to | |
512 | UREGNO in a debug insn. Create a bitmap for DEBUG as needed. */ | |
513 | ||
e6637753 | 514 | void |
dcd028e1 | 515 | dead_debug_add (struct dead_debug_local *debug, df_ref use, unsigned int uregno) |
e6637753 | 516 | { |
dcd028e1 | 517 | if (dead_debug_global_replace_temp (debug->global, use, uregno, |
518 | &debug->to_rescan)) | |
519 | return; | |
520 | ||
e6637753 | 521 | struct dead_debug_use *newddu = XNEW (struct dead_debug_use); |
522 | ||
523 | newddu->use = use; | |
524 | newddu->next = debug->head; | |
525 | debug->head = newddu; | |
526 | ||
527 | if (!debug->used) | |
528 | debug->used = BITMAP_ALLOC (NULL); | |
529 | ||
530 | /* ??? If we dealt with split multi-registers below, we should set | |
531 | all registers for the used mode in case of hardware | |
532 | registers. */ | |
533 | bitmap_set_bit (debug->used, uregno); | |
534 | } | |
535 | ||
596f7cca | 536 | /* Like lowpart_subreg, but if a subreg is not valid for machine, force |
537 | it anyway - for use in debug insns. */ | |
538 | ||
539 | static rtx | |
540 | debug_lowpart_subreg (machine_mode outer_mode, rtx expr, | |
541 | machine_mode inner_mode) | |
542 | { | |
543 | if (inner_mode == VOIDmode) | |
544 | inner_mode = GET_MODE (expr); | |
545 | int offset = subreg_lowpart_offset (outer_mode, inner_mode); | |
546 | rtx ret = simplify_gen_subreg (outer_mode, expr, inner_mode, offset); | |
547 | if (ret) | |
548 | return ret; | |
549 | return gen_rtx_raw_SUBREG (outer_mode, expr, offset); | |
550 | } | |
551 | ||
e6637753 | 552 | /* If UREGNO is referenced by any entry in DEBUG, emit a debug insn |
dcd028e1 | 553 | before or after INSN (depending on WHERE), that binds a (possibly |
554 | global) debug temp to the widest-mode use of UREGNO, if WHERE is | |
555 | *_WITH_REG, or the value stored in UREGNO by INSN otherwise, and | |
556 | replace all uses of UREGNO in DEBUG with uses of the debug temp. | |
557 | INSN must be where UREGNO dies, if WHERE is *_BEFORE_*, or where it | |
558 | is set otherwise. Return the number of debug insns emitted. */ | |
559 | ||
e6637753 | 560 | int |
dcd028e1 | 561 | dead_debug_insert_temp (struct dead_debug_local *debug, unsigned int uregno, |
25bf5e12 | 562 | rtx_insn *insn, enum debug_temp_where where) |
e6637753 | 563 | { |
564 | struct dead_debug_use **tailp = &debug->head; | |
565 | struct dead_debug_use *cur; | |
566 | struct dead_debug_use *uses = NULL; | |
567 | struct dead_debug_use **usesp = &uses; | |
dcd028e1 | 568 | rtx reg = NULL_RTX; |
e6637753 | 569 | rtx breg; |
dcd028e1 | 570 | rtx dval = NULL_RTX; |
e6637753 | 571 | rtx bind; |
dcd028e1 | 572 | bool global; |
e6637753 | 573 | |
dcd028e1 | 574 | if (!debug->used) |
575 | return 0; | |
576 | ||
577 | global = (debug->global && debug->global->used | |
578 | && bitmap_bit_p (debug->global->used, uregno)); | |
579 | ||
580 | if (!global && !bitmap_clear_bit (debug->used, uregno)) | |
e6637753 | 581 | return 0; |
582 | ||
583 | /* Move all uses of uregno from debug->head to uses, setting mode to | |
584 | the widest referenced mode. */ | |
585 | while ((cur = *tailp)) | |
586 | { | |
587 | if (DF_REF_REGNO (cur->use) == uregno) | |
588 | { | |
c41441bb | 589 | /* If this loc has been changed e.g. to debug_expr already |
590 | as part of a multi-register use, just drop it. */ | |
591 | if (!REG_P (*DF_REF_REAL_LOC (cur->use))) | |
592 | { | |
593 | *tailp = cur->next; | |
594 | XDELETE (cur); | |
595 | continue; | |
596 | } | |
e6637753 | 597 | *usesp = cur; |
598 | usesp = &cur->next; | |
599 | *tailp = cur->next; | |
600 | cur->next = NULL; | |
601 | if (!reg | |
602 | || (GET_MODE_BITSIZE (GET_MODE (reg)) | |
603 | < GET_MODE_BITSIZE (GET_MODE (*DF_REF_REAL_LOC (cur->use))))) | |
604 | reg = *DF_REF_REAL_LOC (cur->use); | |
605 | } | |
606 | else | |
607 | tailp = &(*tailp)->next; | |
608 | } | |
609 | ||
610 | /* We may have dangling bits in debug->used for registers that were part | |
611 | of a multi-register use, one component of which has been reset. */ | |
612 | if (reg == NULL) | |
613 | { | |
614 | gcc_checking_assert (!uses); | |
dcd028e1 | 615 | if (!global) |
616 | return 0; | |
617 | } | |
618 | ||
619 | if (global) | |
620 | { | |
621 | if (!reg) | |
622 | reg = regno_reg_rtx[uregno]; | |
623 | dead_debug_global_entry *entry | |
624 | = dead_debug_global_find (debug->global, reg); | |
625 | gcc_checking_assert (entry->reg == reg); | |
626 | dval = entry->dtemp; | |
92a66fbd | 627 | if (!dval) |
628 | return 0; | |
e6637753 | 629 | } |
630 | ||
dcd028e1 | 631 | gcc_checking_assert (uses || global); |
e6637753 | 632 | |
633 | breg = reg; | |
634 | /* Recover the expression INSN stores in REG. */ | |
635 | if (where == DEBUG_TEMP_BEFORE_WITH_VALUE) | |
636 | { | |
637 | rtx set = single_set (insn); | |
638 | rtx dest, src; | |
639 | ||
640 | if (set) | |
641 | { | |
642 | dest = SET_DEST (set); | |
643 | src = SET_SRC (set); | |
644 | /* Lose if the REG-setting insn is a CALL. */ | |
645 | if (GET_CODE (src) == CALL) | |
646 | { | |
647 | while (uses) | |
648 | { | |
649 | cur = uses->next; | |
650 | XDELETE (uses); | |
651 | uses = cur; | |
652 | } | |
653 | return 0; | |
654 | } | |
655 | } | |
656 | ||
657 | /* ??? Should we try to extract it from a PARALLEL? */ | |
658 | if (!set) | |
659 | breg = NULL; | |
660 | /* Cool, it's the same REG, we can use SRC. */ | |
661 | else if (dest == reg) | |
26f0a6e0 | 662 | breg = cleanup_auto_inc_dec (src, VOIDmode); |
e6637753 | 663 | else if (REG_P (dest)) |
664 | { | |
665 | /* Hmm... Something's fishy, we should be setting REG here. */ | |
666 | if (REGNO (dest) != REGNO (reg)) | |
667 | breg = NULL; | |
668 | /* If we're not overwriting all the hardware registers that | |
669 | setting REG in its mode would, we won't know what to bind | |
670 | the debug temp to. ??? We could bind the debug_expr to a | |
671 | CONCAT or PARALLEL with the split multi-registers, and | |
672 | replace them as we found the corresponding sets. */ | |
0933f1d9 | 673 | else if (REG_NREGS (reg) != REG_NREGS (dest)) |
e6637753 | 674 | breg = NULL; |
675 | /* Ok, it's the same (hardware) REG, but with a different | |
676 | mode, so SUBREG it. */ | |
677 | else | |
596f7cca | 678 | breg = debug_lowpart_subreg (GET_MODE (reg), |
679 | cleanup_auto_inc_dec (src, VOIDmode), | |
680 | GET_MODE (dest)); | |
e6637753 | 681 | } |
682 | else if (GET_CODE (dest) == SUBREG) | |
683 | { | |
684 | /* We should be setting REG here. Lose. */ | |
685 | if (REGNO (SUBREG_REG (dest)) != REGNO (reg)) | |
686 | breg = NULL; | |
687 | /* Lose if we're setting something other than the lowpart of | |
688 | REG. */ | |
689 | else if (!subreg_lowpart_p (dest)) | |
690 | breg = NULL; | |
691 | /* If we're not overwriting all the hardware registers that | |
692 | setting REG in its mode would, we won't know what to bind | |
693 | the debug temp to. */ | |
694 | else if (REGNO (reg) < FIRST_PSEUDO_REGISTER | |
0933f1d9 | 695 | && (REG_NREGS (reg) |
e6637753 | 696 | != hard_regno_nregs[REGNO (reg)][GET_MODE (dest)])) |
697 | breg = NULL; | |
698 | /* Yay, we can use SRC, just adjust its mode. */ | |
699 | else | |
596f7cca | 700 | breg = debug_lowpart_subreg (GET_MODE (reg), |
701 | cleanup_auto_inc_dec (src, VOIDmode), | |
702 | GET_MODE (dest)); | |
e6637753 | 703 | } |
704 | /* Oh well, we're out of luck. */ | |
705 | else | |
706 | breg = NULL; | |
707 | ||
708 | /* We couldn't figure out the value stored in REG, so reset all | |
709 | of its pending debug uses. */ | |
710 | if (!breg) | |
711 | { | |
712 | dead_debug_reset_uses (debug, uses); | |
713 | return 0; | |
714 | } | |
715 | } | |
716 | ||
717 | /* If there's a single (debug) use of an otherwise unused REG, and | |
718 | the debug use is not part of a larger expression, then it | |
719 | probably doesn't make sense to introduce a new debug temp. */ | |
720 | if (where == DEBUG_TEMP_AFTER_WITH_REG && !uses->next) | |
721 | { | |
d4a27d0f | 722 | rtx_insn *next = DF_REF_INSN (uses->use); |
e6637753 | 723 | |
724 | if (DEBUG_INSN_P (next) && reg == INSN_VAR_LOCATION_LOC (next)) | |
725 | { | |
726 | XDELETE (uses); | |
727 | return 0; | |
728 | } | |
729 | } | |
730 | ||
dcd028e1 | 731 | if (!global) |
732 | /* Create DEBUG_EXPR (and DEBUG_EXPR_DECL). */ | |
733 | dval = make_debug_expr_from_rtl (reg); | |
e6637753 | 734 | |
735 | /* Emit a debug bind insn before the insn in which reg dies. */ | |
736 | bind = gen_rtx_VAR_LOCATION (GET_MODE (reg), | |
737 | DEBUG_EXPR_TREE_DECL (dval), breg, | |
738 | VAR_INIT_STATUS_INITIALIZED); | |
739 | ||
6baa953c | 740 | if (where == DEBUG_TEMP_AFTER_WITH_REG |
741 | || where == DEBUG_TEMP_AFTER_WITH_REG_FORCE) | |
e6637753 | 742 | bind = emit_debug_insn_after (bind, insn); |
743 | else | |
744 | bind = emit_debug_insn_before (bind, insn); | |
9ee27052 | 745 | if (debug->to_rescan == NULL) |
746 | debug->to_rescan = BITMAP_ALLOC (NULL); | |
747 | bitmap_set_bit (debug->to_rescan, INSN_UID (bind)); | |
e6637753 | 748 | |
749 | /* Adjust all uses. */ | |
750 | while ((cur = uses)) | |
751 | { | |
752 | if (GET_MODE (*DF_REF_REAL_LOC (cur->use)) == GET_MODE (reg)) | |
753 | *DF_REF_REAL_LOC (cur->use) = dval; | |
754 | else | |
755 | *DF_REF_REAL_LOC (cur->use) | |
596f7cca | 756 | = debug_lowpart_subreg (GET_MODE (*DF_REF_REAL_LOC (cur->use)), dval, |
757 | GET_MODE (dval)); | |
e6637753 | 758 | /* ??? Should we simplify subreg of subreg? */ |
e6637753 | 759 | bitmap_set_bit (debug->to_rescan, INSN_UID (DF_REF_INSN (cur->use))); |
760 | uses = cur->next; | |
761 | XDELETE (cur); | |
762 | } | |
763 | ||
764 | return 1; | |
765 | } |