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Commit | Line | Data |
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08df6c0d AO |
1 | /* Infrastructure for tracking user variable locations and values |
2 | throughout compilation. | |
818ab71a | 3 | Copyright (C) 2010-2016 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" | |
c7131fb2 | 25 | #include "backend.h" |
08df6c0d | 26 | #include "rtl.h" |
c7131fb2 | 27 | #include "df.h" |
08df6c0d | 28 | #include "valtrack.h" |
08df6c0d | 29 | #include "regs.h" |
4d0cdd0c | 30 | #include "memmodel.h" |
08df6c0d AO |
31 | #include "emit-rtl.h" |
32 | ||
e90c56c6 JJ |
33 | /* gen_lowpart_no_emit hook implementation for DEBUG_INSNs. In DEBUG_INSNs, |
34 | all lowpart SUBREGs are valid, despite what the machine requires for | |
35 | instructions. */ | |
36 | ||
37 | static rtx | |
ef4bddc2 | 38 | gen_lowpart_for_debug (machine_mode mode, rtx x) |
e90c56c6 JJ |
39 | { |
40 | rtx result = gen_lowpart_if_possible (mode, x); | |
41 | if (result) | |
42 | return result; | |
43 | ||
44 | if (GET_MODE (x) != VOIDmode) | |
45 | return gen_rtx_raw_SUBREG (mode, x, | |
46 | subreg_lowpart_offset (mode, GET_MODE (x))); | |
47 | ||
48 | return NULL_RTX; | |
49 | } | |
50 | ||
08df6c0d AO |
51 | /* Replace auto-increment addressing modes with explicit operations to access |
52 | the same addresses without modifying the corresponding registers. */ | |
53 | ||
08df6c0d | 54 | static rtx |
ef4bddc2 | 55 | cleanup_auto_inc_dec (rtx src, machine_mode mem_mode ATTRIBUTE_UNUSED) |
08df6c0d AO |
56 | { |
57 | rtx x = src; | |
760edf20 TS |
58 | if (!AUTO_INC_DEC) |
59 | return copy_rtx (x); | |
60 | ||
08df6c0d AO |
61 | const RTX_CODE code = GET_CODE (x); |
62 | int i; | |
63 | const char *fmt; | |
64 | ||
65 | switch (code) | |
66 | { | |
67 | case REG: | |
d8116890 | 68 | CASE_CONST_ANY: |
08df6c0d AO |
69 | case SYMBOL_REF: |
70 | case CODE_LABEL: | |
71 | case PC: | |
72 | case CC0: | |
73 | case SCRATCH: | |
74 | /* SCRATCH must be shared because they represent distinct values. */ | |
75 | return x; | |
76 | case CLOBBER: | |
c5c5ba89 JH |
77 | /* Share clobbers of hard registers (like cc0), but do not share pseudo reg |
78 | clobbers or clobbers of hard registers that originated as pseudos. | |
79 | This is needed to allow safe register renaming. */ | |
80 | if (REG_P (XEXP (x, 0)) && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER | |
81 | && ORIGINAL_REGNO (XEXP (x, 0)) == REGNO (XEXP (x, 0))) | |
08df6c0d AO |
82 | return x; |
83 | break; | |
84 | ||
85 | case CONST: | |
86 | if (shared_const_p (x)) | |
87 | return x; | |
88 | break; | |
89 | ||
90 | case MEM: | |
91 | mem_mode = GET_MODE (x); | |
92 | break; | |
93 | ||
94 | case PRE_INC: | |
95 | case PRE_DEC: | |
96 | gcc_assert (mem_mode != VOIDmode && mem_mode != BLKmode); | |
97 | return gen_rtx_PLUS (GET_MODE (x), | |
98 | cleanup_auto_inc_dec (XEXP (x, 0), mem_mode), | |
4789c0ce RS |
99 | gen_int_mode (code == PRE_INC |
100 | ? GET_MODE_SIZE (mem_mode) | |
101 | : -GET_MODE_SIZE (mem_mode), | |
102 | GET_MODE (x))); | |
08df6c0d AO |
103 | |
104 | case POST_INC: | |
105 | case POST_DEC: | |
106 | case PRE_MODIFY: | |
107 | case POST_MODIFY: | |
108 | return cleanup_auto_inc_dec (code == PRE_MODIFY | |
109 | ? XEXP (x, 1) : XEXP (x, 0), | |
110 | mem_mode); | |
111 | ||
112 | default: | |
113 | break; | |
114 | } | |
115 | ||
116 | /* Copy the various flags, fields, and other information. We assume | |
117 | that all fields need copying, and then clear the fields that should | |
118 | not be copied. That is the sensible default behavior, and forces | |
119 | us to explicitly document why we are *not* copying a flag. */ | |
120 | x = shallow_copy_rtx (x); | |
121 | ||
122 | /* We do not copy the USED flag, which is used as a mark bit during | |
123 | walks over the RTL. */ | |
124 | RTX_FLAG (x, used) = 0; | |
125 | ||
126 | /* We do not copy FRAME_RELATED for INSNs. */ | |
127 | if (INSN_P (x)) | |
128 | RTX_FLAG (x, frame_related) = 0; | |
129 | ||
130 | fmt = GET_RTX_FORMAT (code); | |
131 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
132 | if (fmt[i] == 'e') | |
133 | XEXP (x, i) = cleanup_auto_inc_dec (XEXP (x, i), mem_mode); | |
134 | else if (fmt[i] == 'E' || fmt[i] == 'V') | |
135 | { | |
136 | int j; | |
137 | XVEC (x, i) = rtvec_alloc (XVECLEN (x, i)); | |
138 | for (j = 0; j < XVECLEN (x, i); j++) | |
139 | XVECEXP (x, i, j) | |
140 | = cleanup_auto_inc_dec (XVECEXP (src, i, j), mem_mode); | |
141 | } | |
142 | ||
143 | return x; | |
144 | } | |
08df6c0d AO |
145 | |
146 | /* Auxiliary data structure for propagate_for_debug_stmt. */ | |
147 | ||
148 | struct rtx_subst_pair | |
149 | { | |
150 | rtx to; | |
151 | bool adjusted; | |
152 | }; | |
153 | ||
154 | /* DATA points to an rtx_subst_pair. Return the value that should be | |
155 | substituted. */ | |
156 | ||
157 | static rtx | |
158 | propagate_for_debug_subst (rtx from, const_rtx old_rtx, void *data) | |
159 | { | |
160 | struct rtx_subst_pair *pair = (struct rtx_subst_pair *)data; | |
161 | ||
162 | if (!rtx_equal_p (from, old_rtx)) | |
163 | return NULL_RTX; | |
164 | if (!pair->adjusted) | |
165 | { | |
166 | pair->adjusted = true; | |
08df6c0d | 167 | pair->to = cleanup_auto_inc_dec (pair->to, VOIDmode); |
08df6c0d AO |
168 | pair->to = make_compound_operation (pair->to, SET); |
169 | return pair->to; | |
170 | } | |
171 | return copy_rtx (pair->to); | |
172 | } | |
173 | ||
174 | /* Replace all the occurrences of DEST with SRC in DEBUG_INSNs between INSN | |
175 | and LAST, not including INSN, but including LAST. Also stop at the end | |
176 | of THIS_BASIC_BLOCK. */ | |
177 | ||
178 | void | |
dc01c3d1 | 179 | propagate_for_debug (rtx_insn *insn, rtx_insn *last, rtx dest, rtx src, |
08df6c0d AO |
180 | basic_block this_basic_block) |
181 | { | |
b2908ba6 DM |
182 | rtx_insn *next, *end = NEXT_INSN (BB_END (this_basic_block)); |
183 | rtx loc; | |
ef4bddc2 | 184 | rtx (*saved_rtl_hook_no_emit) (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, | |
026c3cfd | 281 | replace it with a USE of the debug temp recorded for it, and |
e9f950ba AO |
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; | |
1cbcd833 | 346 | rtx_insn *insn; |
08df6c0d AO |
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 | { | |
1cbcd833 | 434 | rtx_insn *insn = DF_REF_INSN (ref); |
0e45ec20 AO |
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); | |
1cbcd833 | 450 | rtx_insn *insn = emit_debug_insn_before (bind, DF_REF_INSN (ref)); |
0e45ec20 AO |
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 | ||
e488c24e JJ |
528 | /* Like lowpart_subreg, but if a subreg is not valid for machine, force |
529 | it anyway - for use in debug insns. */ | |
530 | ||
531 | static rtx | |
532 | debug_lowpart_subreg (machine_mode outer_mode, rtx expr, | |
533 | machine_mode inner_mode) | |
534 | { | |
535 | if (inner_mode == VOIDmode) | |
536 | inner_mode = GET_MODE (expr); | |
537 | int offset = subreg_lowpart_offset (outer_mode, inner_mode); | |
538 | rtx ret = simplify_gen_subreg (outer_mode, expr, inner_mode, offset); | |
539 | if (ret) | |
540 | return ret; | |
541 | return gen_rtx_raw_SUBREG (outer_mode, expr, offset); | |
542 | } | |
543 | ||
08df6c0d | 544 | /* If UREGNO is referenced by any entry in DEBUG, emit a debug insn |
e9f950ba AO |
545 | before or after INSN (depending on WHERE), that binds a (possibly |
546 | global) debug temp to the widest-mode use of UREGNO, if WHERE is | |
547 | *_WITH_REG, or the value stored in UREGNO by INSN otherwise, and | |
548 | replace all uses of UREGNO in DEBUG with uses of the debug temp. | |
549 | INSN must be where UREGNO dies, if WHERE is *_BEFORE_*, or where it | |
550 | is set otherwise. Return the number of debug insns emitted. */ | |
551 | ||
08df6c0d | 552 | int |
e9f950ba | 553 | dead_debug_insert_temp (struct dead_debug_local *debug, unsigned int uregno, |
f38a26e5 | 554 | rtx_insn *insn, enum debug_temp_where where) |
08df6c0d AO |
555 | { |
556 | struct dead_debug_use **tailp = &debug->head; | |
557 | struct dead_debug_use *cur; | |
558 | struct dead_debug_use *uses = NULL; | |
559 | struct dead_debug_use **usesp = &uses; | |
e9f950ba | 560 | rtx reg = NULL_RTX; |
08df6c0d | 561 | rtx breg; |
e9f950ba | 562 | rtx dval = NULL_RTX; |
08df6c0d | 563 | rtx bind; |
e9f950ba | 564 | bool global; |
08df6c0d | 565 | |
e9f950ba AO |
566 | if (!debug->used) |
567 | return 0; | |
568 | ||
569 | global = (debug->global && debug->global->used | |
570 | && bitmap_bit_p (debug->global->used, uregno)); | |
571 | ||
572 | if (!global && !bitmap_clear_bit (debug->used, uregno)) | |
08df6c0d AO |
573 | return 0; |
574 | ||
575 | /* Move all uses of uregno from debug->head to uses, setting mode to | |
576 | the widest referenced mode. */ | |
577 | while ((cur = *tailp)) | |
578 | { | |
579 | if (DF_REF_REGNO (cur->use) == uregno) | |
580 | { | |
d540153b JJ |
581 | /* If this loc has been changed e.g. to debug_expr already |
582 | as part of a multi-register use, just drop it. */ | |
583 | if (!REG_P (*DF_REF_REAL_LOC (cur->use))) | |
584 | { | |
585 | *tailp = cur->next; | |
586 | XDELETE (cur); | |
587 | continue; | |
588 | } | |
08df6c0d AO |
589 | *usesp = cur; |
590 | usesp = &cur->next; | |
591 | *tailp = cur->next; | |
592 | cur->next = NULL; | |
593 | if (!reg | |
594 | || (GET_MODE_BITSIZE (GET_MODE (reg)) | |
595 | < GET_MODE_BITSIZE (GET_MODE (*DF_REF_REAL_LOC (cur->use))))) | |
596 | reg = *DF_REF_REAL_LOC (cur->use); | |
597 | } | |
598 | else | |
599 | tailp = &(*tailp)->next; | |
600 | } | |
601 | ||
602 | /* We may have dangling bits in debug->used for registers that were part | |
603 | of a multi-register use, one component of which has been reset. */ | |
604 | if (reg == NULL) | |
605 | { | |
606 | gcc_checking_assert (!uses); | |
e9f950ba AO |
607 | if (!global) |
608 | return 0; | |
609 | } | |
610 | ||
611 | if (global) | |
612 | { | |
613 | if (!reg) | |
614 | reg = regno_reg_rtx[uregno]; | |
615 | dead_debug_global_entry *entry | |
616 | = dead_debug_global_find (debug->global, reg); | |
617 | gcc_checking_assert (entry->reg == reg); | |
618 | dval = entry->dtemp; | |
0e45ec20 AO |
619 | if (!dval) |
620 | return 0; | |
08df6c0d AO |
621 | } |
622 | ||
e9f950ba | 623 | gcc_checking_assert (uses || global); |
08df6c0d AO |
624 | |
625 | breg = reg; | |
626 | /* Recover the expression INSN stores in REG. */ | |
627 | if (where == DEBUG_TEMP_BEFORE_WITH_VALUE) | |
628 | { | |
629 | rtx set = single_set (insn); | |
630 | rtx dest, src; | |
631 | ||
632 | if (set) | |
633 | { | |
634 | dest = SET_DEST (set); | |
635 | src = SET_SRC (set); | |
636 | /* Lose if the REG-setting insn is a CALL. */ | |
637 | if (GET_CODE (src) == CALL) | |
638 | { | |
639 | while (uses) | |
640 | { | |
641 | cur = uses->next; | |
642 | XDELETE (uses); | |
643 | uses = cur; | |
644 | } | |
645 | return 0; | |
646 | } | |
647 | } | |
648 | ||
649 | /* ??? Should we try to extract it from a PARALLEL? */ | |
650 | if (!set) | |
651 | breg = NULL; | |
652 | /* Cool, it's the same REG, we can use SRC. */ | |
653 | else if (dest == reg) | |
e7206ab1 | 654 | breg = cleanup_auto_inc_dec (src, VOIDmode); |
08df6c0d AO |
655 | else if (REG_P (dest)) |
656 | { | |
657 | /* Hmm... Something's fishy, we should be setting REG here. */ | |
658 | if (REGNO (dest) != REGNO (reg)) | |
659 | breg = NULL; | |
660 | /* If we're not overwriting all the hardware registers that | |
661 | setting REG in its mode would, we won't know what to bind | |
662 | the debug temp to. ??? We could bind the debug_expr to a | |
663 | CONCAT or PARALLEL with the split multi-registers, and | |
664 | replace them as we found the corresponding sets. */ | |
dc8afb70 | 665 | else if (REG_NREGS (reg) != REG_NREGS (dest)) |
08df6c0d AO |
666 | breg = NULL; |
667 | /* Ok, it's the same (hardware) REG, but with a different | |
668 | mode, so SUBREG it. */ | |
669 | else | |
e488c24e JJ |
670 | breg = debug_lowpart_subreg (GET_MODE (reg), |
671 | cleanup_auto_inc_dec (src, VOIDmode), | |
672 | GET_MODE (dest)); | |
08df6c0d AO |
673 | } |
674 | else if (GET_CODE (dest) == SUBREG) | |
675 | { | |
676 | /* We should be setting REG here. Lose. */ | |
677 | if (REGNO (SUBREG_REG (dest)) != REGNO (reg)) | |
678 | breg = NULL; | |
679 | /* Lose if we're setting something other than the lowpart of | |
680 | REG. */ | |
681 | else if (!subreg_lowpart_p (dest)) | |
682 | breg = NULL; | |
683 | /* If we're not overwriting all the hardware registers that | |
684 | setting REG in its mode would, we won't know what to bind | |
685 | the debug temp to. */ | |
686 | else if (REGNO (reg) < FIRST_PSEUDO_REGISTER | |
dc8afb70 | 687 | && (REG_NREGS (reg) |
08df6c0d AO |
688 | != hard_regno_nregs[REGNO (reg)][GET_MODE (dest)])) |
689 | breg = NULL; | |
690 | /* Yay, we can use SRC, just adjust its mode. */ | |
691 | else | |
e488c24e JJ |
692 | breg = debug_lowpart_subreg (GET_MODE (reg), |
693 | cleanup_auto_inc_dec (src, VOIDmode), | |
694 | GET_MODE (dest)); | |
08df6c0d AO |
695 | } |
696 | /* Oh well, we're out of luck. */ | |
697 | else | |
698 | breg = NULL; | |
699 | ||
700 | /* We couldn't figure out the value stored in REG, so reset all | |
701 | of its pending debug uses. */ | |
702 | if (!breg) | |
703 | { | |
704 | dead_debug_reset_uses (debug, uses); | |
705 | return 0; | |
706 | } | |
707 | } | |
708 | ||
709 | /* If there's a single (debug) use of an otherwise unused REG, and | |
710 | the debug use is not part of a larger expression, then it | |
711 | probably doesn't make sense to introduce a new debug temp. */ | |
712 | if (where == DEBUG_TEMP_AFTER_WITH_REG && !uses->next) | |
713 | { | |
1cbcd833 | 714 | rtx_insn *next = DF_REF_INSN (uses->use); |
08df6c0d AO |
715 | |
716 | if (DEBUG_INSN_P (next) && reg == INSN_VAR_LOCATION_LOC (next)) | |
717 | { | |
718 | XDELETE (uses); | |
719 | return 0; | |
720 | } | |
721 | } | |
722 | ||
e9f950ba AO |
723 | if (!global) |
724 | /* Create DEBUG_EXPR (and DEBUG_EXPR_DECL). */ | |
725 | dval = make_debug_expr_from_rtl (reg); | |
08df6c0d AO |
726 | |
727 | /* Emit a debug bind insn before the insn in which reg dies. */ | |
728 | bind = gen_rtx_VAR_LOCATION (GET_MODE (reg), | |
729 | DEBUG_EXPR_TREE_DECL (dval), breg, | |
730 | VAR_INIT_STATUS_INITIALIZED); | |
731 | ||
85d87497 JJ |
732 | if (where == DEBUG_TEMP_AFTER_WITH_REG |
733 | || where == DEBUG_TEMP_AFTER_WITH_REG_FORCE) | |
08df6c0d AO |
734 | bind = emit_debug_insn_after (bind, insn); |
735 | else | |
736 | bind = emit_debug_insn_before (bind, insn); | |
36290bb4 AO |
737 | if (debug->to_rescan == NULL) |
738 | debug->to_rescan = BITMAP_ALLOC (NULL); | |
739 | bitmap_set_bit (debug->to_rescan, INSN_UID (bind)); | |
08df6c0d AO |
740 | |
741 | /* Adjust all uses. */ | |
742 | while ((cur = uses)) | |
743 | { | |
744 | if (GET_MODE (*DF_REF_REAL_LOC (cur->use)) == GET_MODE (reg)) | |
745 | *DF_REF_REAL_LOC (cur->use) = dval; | |
746 | else | |
747 | *DF_REF_REAL_LOC (cur->use) | |
e488c24e JJ |
748 | = debug_lowpart_subreg (GET_MODE (*DF_REF_REAL_LOC (cur->use)), dval, |
749 | GET_MODE (dval)); | |
08df6c0d | 750 | /* ??? Should we simplify subreg of subreg? */ |
08df6c0d AO |
751 | bitmap_set_bit (debug->to_rescan, INSN_UID (DF_REF_INSN (cur->use))); |
752 | uses = cur->next; | |
753 | XDELETE (cur); | |
754 | } | |
755 | ||
756 | return 1; | |
757 | } |