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fa49fd0f RK |
1 | /* Common subexpression elimination library for GNU compiler. |
2 | Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, | |
3 | 1999, 2000, 2001 Free Software Foundation, Inc. | |
4 | ||
1322177d | 5 | This file is part of GCC. |
fa49fd0f | 6 | |
1322177d LB |
7 | GCC is free software; you can redistribute it and/or modify it under |
8 | the terms of the GNU General Public License as published by the Free | |
9 | Software Foundation; either version 2, or (at your option) any later | |
10 | version. | |
fa49fd0f | 11 | |
1322177d LB |
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
fa49fd0f RK |
16 | |
17 | You should have received a copy of the GNU General Public License | |
1322177d LB |
18 | along with GCC; see the file COPYING. If not, write to the Free |
19 | Software Foundation, 59 Temple Place - Suite 330, Boston, MA | |
20 | 02111-1307, USA. */ | |
fa49fd0f RK |
21 | |
22 | #include "config.h" | |
23 | #include "system.h" | |
fa49fd0f RK |
24 | |
25 | #include "rtl.h" | |
26 | #include "tm_p.h" | |
27 | #include "regs.h" | |
28 | #include "hard-reg-set.h" | |
29 | #include "flags.h" | |
30 | #include "real.h" | |
31 | #include "insn-config.h" | |
32 | #include "recog.h" | |
33 | #include "function.h" | |
34 | #include "expr.h" | |
35 | #include "toplev.h" | |
36 | #include "output.h" | |
37 | #include "ggc.h" | |
fa49fd0f RK |
38 | #include "hashtab.h" |
39 | #include "cselib.h" | |
40 | ||
41 | static int entry_and_rtx_equal_p PARAMS ((const void *, const void *)); | |
42 | static unsigned int get_value_hash PARAMS ((const void *)); | |
43 | static struct elt_list *new_elt_list PARAMS ((struct elt_list *, | |
44 | cselib_val *)); | |
45 | static struct elt_loc_list *new_elt_loc_list PARAMS ((struct elt_loc_list *, | |
46 | rtx)); | |
47 | static void unchain_one_value PARAMS ((cselib_val *)); | |
48 | static void unchain_one_elt_list PARAMS ((struct elt_list **)); | |
49 | static void unchain_one_elt_loc_list PARAMS ((struct elt_loc_list **)); | |
50 | static void clear_table PARAMS ((int)); | |
51 | static int discard_useless_locs PARAMS ((void **, void *)); | |
52 | static int discard_useless_values PARAMS ((void **, void *)); | |
53 | static void remove_useless_values PARAMS ((void)); | |
54 | static rtx wrap_constant PARAMS ((enum machine_mode, rtx)); | |
55 | static unsigned int hash_rtx PARAMS ((rtx, enum machine_mode, int)); | |
56 | static cselib_val *new_cselib_val PARAMS ((unsigned int, | |
57 | enum machine_mode)); | |
58 | static void add_mem_for_addr PARAMS ((cselib_val *, cselib_val *, | |
59 | rtx)); | |
60 | static cselib_val *cselib_lookup_mem PARAMS ((rtx, int)); | |
fa49fd0f RK |
61 | static void cselib_invalidate_regno PARAMS ((unsigned int, |
62 | enum machine_mode)); | |
63 | static int cselib_mem_conflict_p PARAMS ((rtx, rtx)); | |
64 | static int cselib_invalidate_mem_1 PARAMS ((void **, void *)); | |
65 | static void cselib_invalidate_mem PARAMS ((rtx)); | |
66 | static void cselib_invalidate_rtx PARAMS ((rtx, rtx, void *)); | |
67 | static void cselib_record_set PARAMS ((rtx, cselib_val *, | |
68 | cselib_val *)); | |
69 | static void cselib_record_sets PARAMS ((rtx)); | |
70 | ||
71 | /* There are three ways in which cselib can look up an rtx: | |
72 | - for a REG, the reg_values table (which is indexed by regno) is used | |
73 | - for a MEM, we recursively look up its address and then follow the | |
74 | addr_list of that value | |
75 | - for everything else, we compute a hash value and go through the hash | |
76 | table. Since different rtx's can still have the same hash value, | |
77 | this involves walking the table entries for a given value and comparing | |
78 | the locations of the entries with the rtx we are looking up. */ | |
79 | ||
80 | /* A table that enables us to look up elts by their value. */ | |
e2500fed | 81 | static GTY((param_is (cselib_val))) htab_t hash_table; |
fa49fd0f RK |
82 | |
83 | /* This is a global so we don't have to pass this through every function. | |
84 | It is used in new_elt_loc_list to set SETTING_INSN. */ | |
85 | static rtx cselib_current_insn; | |
86 | ||
87 | /* Every new unknown value gets a unique number. */ | |
88 | static unsigned int next_unknown_value; | |
89 | ||
90 | /* The number of registers we had when the varrays were last resized. */ | |
91 | static unsigned int cselib_nregs; | |
92 | ||
93 | /* Count values without known locations. Whenever this grows too big, we | |
94 | remove these useless values from the table. */ | |
95 | static int n_useless_values; | |
96 | ||
97 | /* Number of useless values before we remove them from the hash table. */ | |
98 | #define MAX_USELESS_VALUES 32 | |
99 | ||
100 | /* This table maps from register number to values. It does not contain | |
101 | pointers to cselib_val structures, but rather elt_lists. The purpose is | |
102 | to be able to refer to the same register in different modes. */ | |
e2500fed GK |
103 | static GTY(()) varray_type reg_values; |
104 | static GTY((deletable (""))) varray_type reg_values_old; | |
fa49fd0f RK |
105 | #define REG_VALUES(I) VARRAY_ELT_LIST (reg_values, (I)) |
106 | ||
31825e57 DM |
107 | /* The largest number of hard regs used by any entry added to the |
108 | REG_VALUES table. Cleared on each clear_table() invocation. */ | |
109 | static unsigned int max_value_regs; | |
110 | ||
fa49fd0f RK |
111 | /* Here the set of indices I with REG_VALUES(I) != 0 is saved. This is used |
112 | in clear_table() for fast emptying. */ | |
e2500fed GK |
113 | static GTY(()) varray_type used_regs; |
114 | static GTY((deletable (""))) varray_type used_regs_old; | |
fa49fd0f RK |
115 | |
116 | /* We pass this to cselib_invalidate_mem to invalidate all of | |
117 | memory for a non-const call instruction. */ | |
e2500fed | 118 | static GTY(()) rtx callmem; |
fa49fd0f RK |
119 | |
120 | /* Caches for unused structures. */ | |
e2500fed GK |
121 | static GTY((deletable (""))) cselib_val *empty_vals; |
122 | static GTY((deletable (""))) struct elt_list *empty_elt_lists; | |
123 | static GTY((deletable (""))) struct elt_loc_list *empty_elt_loc_lists; | |
fa49fd0f RK |
124 | |
125 | /* Set by discard_useless_locs if it deleted the last location of any | |
126 | value. */ | |
127 | static int values_became_useless; | |
128 | \f | |
129 | ||
130 | /* Allocate a struct elt_list and fill in its two elements with the | |
131 | arguments. */ | |
132 | ||
133 | static struct elt_list * | |
134 | new_elt_list (next, elt) | |
135 | struct elt_list *next; | |
136 | cselib_val *elt; | |
137 | { | |
138 | struct elt_list *el = empty_elt_lists; | |
139 | ||
140 | if (el) | |
141 | empty_elt_lists = el->next; | |
142 | else | |
e2500fed | 143 | el = (struct elt_list *) ggc_alloc (sizeof (struct elt_list)); |
fa49fd0f RK |
144 | el->next = next; |
145 | el->elt = elt; | |
146 | return el; | |
147 | } | |
148 | ||
149 | /* Allocate a struct elt_loc_list and fill in its two elements with the | |
150 | arguments. */ | |
151 | ||
152 | static struct elt_loc_list * | |
153 | new_elt_loc_list (next, loc) | |
154 | struct elt_loc_list *next; | |
155 | rtx loc; | |
156 | { | |
157 | struct elt_loc_list *el = empty_elt_loc_lists; | |
158 | ||
159 | if (el) | |
160 | empty_elt_loc_lists = el->next; | |
161 | else | |
e2500fed | 162 | el = (struct elt_loc_list *) ggc_alloc (sizeof (struct elt_loc_list)); |
fa49fd0f RK |
163 | el->next = next; |
164 | el->loc = loc; | |
165 | el->setting_insn = cselib_current_insn; | |
166 | return el; | |
167 | } | |
168 | ||
169 | /* The elt_list at *PL is no longer needed. Unchain it and free its | |
170 | storage. */ | |
171 | ||
172 | static void | |
173 | unchain_one_elt_list (pl) | |
174 | struct elt_list **pl; | |
175 | { | |
176 | struct elt_list *l = *pl; | |
177 | ||
178 | *pl = l->next; | |
179 | l->next = empty_elt_lists; | |
180 | empty_elt_lists = l; | |
181 | } | |
182 | ||
183 | /* Likewise for elt_loc_lists. */ | |
184 | ||
185 | static void | |
186 | unchain_one_elt_loc_list (pl) | |
187 | struct elt_loc_list **pl; | |
188 | { | |
189 | struct elt_loc_list *l = *pl; | |
190 | ||
191 | *pl = l->next; | |
192 | l->next = empty_elt_loc_lists; | |
193 | empty_elt_loc_lists = l; | |
194 | } | |
195 | ||
196 | /* Likewise for cselib_vals. This also frees the addr_list associated with | |
197 | V. */ | |
198 | ||
199 | static void | |
200 | unchain_one_value (v) | |
201 | cselib_val *v; | |
202 | { | |
203 | while (v->addr_list) | |
204 | unchain_one_elt_list (&v->addr_list); | |
205 | ||
206 | v->u.next_free = empty_vals; | |
207 | empty_vals = v; | |
208 | } | |
209 | ||
210 | /* Remove all entries from the hash table. Also used during | |
211 | initialization. If CLEAR_ALL isn't set, then only clear the entries | |
212 | which are known to have been used. */ | |
213 | ||
214 | static void | |
215 | clear_table (clear_all) | |
216 | int clear_all; | |
217 | { | |
218 | unsigned int i; | |
219 | ||
220 | if (clear_all) | |
221 | for (i = 0; i < cselib_nregs; i++) | |
222 | REG_VALUES (i) = 0; | |
223 | else | |
224 | for (i = 0; i < VARRAY_ACTIVE_SIZE (used_regs); i++) | |
225 | REG_VALUES (VARRAY_UINT (used_regs, i)) = 0; | |
226 | ||
31825e57 DM |
227 | max_value_regs = 0; |
228 | ||
fa49fd0f RK |
229 | VARRAY_POP_ALL (used_regs); |
230 | ||
231 | htab_empty (hash_table); | |
fa49fd0f | 232 | |
fa49fd0f RK |
233 | n_useless_values = 0; |
234 | ||
235 | next_unknown_value = 0; | |
236 | } | |
237 | ||
238 | /* The equality test for our hash table. The first argument ENTRY is a table | |
239 | element (i.e. a cselib_val), while the second arg X is an rtx. We know | |
240 | that all callers of htab_find_slot_with_hash will wrap CONST_INTs into a | |
241 | CONST of an appropriate mode. */ | |
242 | ||
243 | static int | |
244 | entry_and_rtx_equal_p (entry, x_arg) | |
245 | const void *entry, *x_arg; | |
246 | { | |
247 | struct elt_loc_list *l; | |
248 | const cselib_val *v = (const cselib_val *) entry; | |
249 | rtx x = (rtx) x_arg; | |
250 | enum machine_mode mode = GET_MODE (x); | |
251 | ||
252 | if (GET_CODE (x) == CONST_INT | |
253 | || (mode == VOIDmode && GET_CODE (x) == CONST_DOUBLE)) | |
254 | abort (); | |
255 | if (mode != GET_MODE (v->u.val_rtx)) | |
256 | return 0; | |
257 | ||
258 | /* Unwrap X if necessary. */ | |
259 | if (GET_CODE (x) == CONST | |
260 | && (GET_CODE (XEXP (x, 0)) == CONST_INT | |
261 | || GET_CODE (XEXP (x, 0)) == CONST_DOUBLE)) | |
262 | x = XEXP (x, 0); | |
263 | ||
264 | /* We don't guarantee that distinct rtx's have different hash values, | |
265 | so we need to do a comparison. */ | |
266 | for (l = v->locs; l; l = l->next) | |
267 | if (rtx_equal_for_cselib_p (l->loc, x)) | |
268 | return 1; | |
269 | ||
270 | return 0; | |
271 | } | |
272 | ||
273 | /* The hash function for our hash table. The value is always computed with | |
274 | hash_rtx when adding an element; this function just extracts the hash | |
275 | value from a cselib_val structure. */ | |
276 | ||
277 | static unsigned int | |
278 | get_value_hash (entry) | |
279 | const void *entry; | |
280 | { | |
281 | const cselib_val *v = (const cselib_val *) entry; | |
282 | return v->value; | |
283 | } | |
284 | ||
285 | /* Return true if X contains a VALUE rtx. If ONLY_USELESS is set, we | |
286 | only return true for values which point to a cselib_val whose value | |
287 | element has been set to zero, which implies the cselib_val will be | |
288 | removed. */ | |
289 | ||
290 | int | |
291 | references_value_p (x, only_useless) | |
292 | rtx x; | |
293 | int only_useless; | |
294 | { | |
295 | enum rtx_code code = GET_CODE (x); | |
296 | const char *fmt = GET_RTX_FORMAT (code); | |
297 | int i, j; | |
298 | ||
299 | if (GET_CODE (x) == VALUE | |
300 | && (! only_useless || CSELIB_VAL_PTR (x)->locs == 0)) | |
301 | return 1; | |
302 | ||
303 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
304 | { | |
305 | if (fmt[i] == 'e' && references_value_p (XEXP (x, i), only_useless)) | |
306 | return 1; | |
307 | else if (fmt[i] == 'E') | |
308 | for (j = 0; j < XVECLEN (x, i); j++) | |
309 | if (references_value_p (XVECEXP (x, i, j), only_useless)) | |
310 | return 1; | |
311 | } | |
312 | ||
313 | return 0; | |
314 | } | |
315 | ||
316 | /* For all locations found in X, delete locations that reference useless | |
317 | values (i.e. values without any location). Called through | |
318 | htab_traverse. */ | |
319 | ||
320 | static int | |
321 | discard_useless_locs (x, info) | |
322 | void **x; | |
323 | void *info ATTRIBUTE_UNUSED; | |
324 | { | |
325 | cselib_val *v = (cselib_val *)*x; | |
326 | struct elt_loc_list **p = &v->locs; | |
327 | int had_locs = v->locs != 0; | |
328 | ||
329 | while (*p) | |
330 | { | |
331 | if (references_value_p ((*p)->loc, 1)) | |
332 | unchain_one_elt_loc_list (p); | |
333 | else | |
334 | p = &(*p)->next; | |
335 | } | |
336 | ||
337 | if (had_locs && v->locs == 0) | |
338 | { | |
339 | n_useless_values++; | |
340 | values_became_useless = 1; | |
341 | } | |
342 | return 1; | |
343 | } | |
344 | ||
345 | /* If X is a value with no locations, remove it from the hashtable. */ | |
346 | ||
347 | static int | |
348 | discard_useless_values (x, info) | |
349 | void **x; | |
350 | void *info ATTRIBUTE_UNUSED; | |
351 | { | |
352 | cselib_val *v = (cselib_val *)*x; | |
353 | ||
354 | if (v->locs == 0) | |
355 | { | |
356 | htab_clear_slot (hash_table, x); | |
357 | unchain_one_value (v); | |
358 | n_useless_values--; | |
359 | } | |
360 | ||
361 | return 1; | |
362 | } | |
363 | ||
364 | /* Clean out useless values (i.e. those which no longer have locations | |
365 | associated with them) from the hash table. */ | |
366 | ||
367 | static void | |
368 | remove_useless_values () | |
369 | { | |
370 | /* First pass: eliminate locations that reference the value. That in | |
371 | turn can make more values useless. */ | |
372 | do | |
373 | { | |
374 | values_became_useless = 0; | |
375 | htab_traverse (hash_table, discard_useless_locs, 0); | |
376 | } | |
377 | while (values_became_useless); | |
378 | ||
379 | /* Second pass: actually remove the values. */ | |
380 | htab_traverse (hash_table, discard_useless_values, 0); | |
381 | ||
382 | if (n_useless_values != 0) | |
383 | abort (); | |
384 | } | |
385 | ||
386 | /* Return nonzero if we can prove that X and Y contain the same value, taking | |
387 | our gathered information into account. */ | |
388 | ||
389 | int | |
390 | rtx_equal_for_cselib_p (x, y) | |
391 | rtx x, y; | |
392 | { | |
393 | enum rtx_code code; | |
394 | const char *fmt; | |
395 | int i; | |
396 | ||
397 | if (GET_CODE (x) == REG || GET_CODE (x) == MEM) | |
398 | { | |
399 | cselib_val *e = cselib_lookup (x, GET_MODE (x), 0); | |
400 | ||
401 | if (e) | |
402 | x = e->u.val_rtx; | |
403 | } | |
404 | ||
405 | if (GET_CODE (y) == REG || GET_CODE (y) == MEM) | |
406 | { | |
407 | cselib_val *e = cselib_lookup (y, GET_MODE (y), 0); | |
408 | ||
409 | if (e) | |
410 | y = e->u.val_rtx; | |
411 | } | |
412 | ||
413 | if (x == y) | |
414 | return 1; | |
415 | ||
416 | if (GET_CODE (x) == VALUE && GET_CODE (y) == VALUE) | |
417 | return CSELIB_VAL_PTR (x) == CSELIB_VAL_PTR (y); | |
418 | ||
419 | if (GET_CODE (x) == VALUE) | |
420 | { | |
421 | cselib_val *e = CSELIB_VAL_PTR (x); | |
422 | struct elt_loc_list *l; | |
423 | ||
424 | for (l = e->locs; l; l = l->next) | |
425 | { | |
426 | rtx t = l->loc; | |
427 | ||
428 | /* Avoid infinite recursion. */ | |
429 | if (GET_CODE (t) == REG || GET_CODE (t) == MEM) | |
430 | continue; | |
431 | else if (rtx_equal_for_cselib_p (t, y)) | |
432 | return 1; | |
433 | } | |
434 | ||
435 | return 0; | |
436 | } | |
437 | ||
438 | if (GET_CODE (y) == VALUE) | |
439 | { | |
440 | cselib_val *e = CSELIB_VAL_PTR (y); | |
441 | struct elt_loc_list *l; | |
442 | ||
443 | for (l = e->locs; l; l = l->next) | |
444 | { | |
445 | rtx t = l->loc; | |
446 | ||
447 | if (GET_CODE (t) == REG || GET_CODE (t) == MEM) | |
448 | continue; | |
449 | else if (rtx_equal_for_cselib_p (x, t)) | |
450 | return 1; | |
451 | } | |
452 | ||
453 | return 0; | |
454 | } | |
455 | ||
456 | if (GET_CODE (x) != GET_CODE (y) || GET_MODE (x) != GET_MODE (y)) | |
457 | return 0; | |
458 | ||
459 | /* This won't be handled correctly by the code below. */ | |
460 | if (GET_CODE (x) == LABEL_REF) | |
461 | return XEXP (x, 0) == XEXP (y, 0); | |
462 | ||
463 | code = GET_CODE (x); | |
464 | fmt = GET_RTX_FORMAT (code); | |
465 | ||
466 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
467 | { | |
468 | int j; | |
469 | ||
470 | switch (fmt[i]) | |
471 | { | |
472 | case 'w': | |
473 | if (XWINT (x, i) != XWINT (y, i)) | |
474 | return 0; | |
475 | break; | |
476 | ||
477 | case 'n': | |
478 | case 'i': | |
479 | if (XINT (x, i) != XINT (y, i)) | |
480 | return 0; | |
481 | break; | |
482 | ||
483 | case 'V': | |
484 | case 'E': | |
485 | /* Two vectors must have the same length. */ | |
486 | if (XVECLEN (x, i) != XVECLEN (y, i)) | |
487 | return 0; | |
488 | ||
489 | /* And the corresponding elements must match. */ | |
490 | for (j = 0; j < XVECLEN (x, i); j++) | |
491 | if (! rtx_equal_for_cselib_p (XVECEXP (x, i, j), | |
492 | XVECEXP (y, i, j))) | |
493 | return 0; | |
494 | break; | |
495 | ||
496 | case 'e': | |
497 | if (! rtx_equal_for_cselib_p (XEXP (x, i), XEXP (y, i))) | |
498 | return 0; | |
499 | break; | |
500 | ||
501 | case 'S': | |
502 | case 's': | |
503 | if (strcmp (XSTR (x, i), XSTR (y, i))) | |
504 | return 0; | |
505 | break; | |
506 | ||
507 | case 'u': | |
508 | /* These are just backpointers, so they don't matter. */ | |
509 | break; | |
510 | ||
511 | case '0': | |
512 | case 't': | |
513 | break; | |
514 | ||
515 | /* It is believed that rtx's at this level will never | |
516 | contain anything but integers and other rtx's, | |
517 | except for within LABEL_REFs and SYMBOL_REFs. */ | |
518 | default: | |
519 | abort (); | |
520 | } | |
521 | } | |
522 | return 1; | |
523 | } | |
524 | ||
525 | /* We need to pass down the mode of constants through the hash table | |
526 | functions. For that purpose, wrap them in a CONST of the appropriate | |
527 | mode. */ | |
528 | static rtx | |
529 | wrap_constant (mode, x) | |
530 | enum machine_mode mode; | |
531 | rtx x; | |
532 | { | |
533 | if (GET_CODE (x) != CONST_INT | |
534 | && (GET_CODE (x) != CONST_DOUBLE || GET_MODE (x) != VOIDmode)) | |
535 | return x; | |
536 | if (mode == VOIDmode) | |
537 | abort (); | |
538 | return gen_rtx_CONST (mode, x); | |
539 | } | |
540 | ||
541 | /* Hash an rtx. Return 0 if we couldn't hash the rtx. | |
542 | For registers and memory locations, we look up their cselib_val structure | |
543 | and return its VALUE element. | |
544 | Possible reasons for return 0 are: the object is volatile, or we couldn't | |
545 | find a register or memory location in the table and CREATE is zero. If | |
546 | CREATE is nonzero, table elts are created for regs and mem. | |
547 | MODE is used in hashing for CONST_INTs only; | |
548 | otherwise the mode of X is used. */ | |
549 | ||
550 | static unsigned int | |
551 | hash_rtx (x, mode, create) | |
552 | rtx x; | |
553 | enum machine_mode mode; | |
554 | int create; | |
555 | { | |
556 | cselib_val *e; | |
557 | int i, j; | |
558 | enum rtx_code code; | |
559 | const char *fmt; | |
560 | unsigned int hash = 0; | |
561 | ||
fa49fd0f RK |
562 | code = GET_CODE (x); |
563 | hash += (unsigned) code + (unsigned) GET_MODE (x); | |
564 | ||
565 | switch (code) | |
566 | { | |
567 | case MEM: | |
568 | case REG: | |
569 | e = cselib_lookup (x, GET_MODE (x), create); | |
570 | if (! e) | |
571 | return 0; | |
572 | ||
a4f4333a | 573 | return e->value; |
fa49fd0f RK |
574 | |
575 | case CONST_INT: | |
576 | hash += ((unsigned) CONST_INT << 7) + (unsigned) mode + INTVAL (x); | |
dc76f41c | 577 | return hash ? hash : (unsigned int) CONST_INT; |
fa49fd0f RK |
578 | |
579 | case CONST_DOUBLE: | |
580 | /* This is like the general case, except that it only counts | |
581 | the integers representing the constant. */ | |
582 | hash += (unsigned) code + (unsigned) GET_MODE (x); | |
583 | if (GET_MODE (x) != VOIDmode) | |
584 | for (i = 2; i < GET_RTX_LENGTH (CONST_DOUBLE); i++) | |
585 | hash += XWINT (x, i); | |
586 | else | |
587 | hash += ((unsigned) CONST_DOUBLE_LOW (x) | |
588 | + (unsigned) CONST_DOUBLE_HIGH (x)); | |
dc76f41c | 589 | return hash ? hash : (unsigned int) CONST_DOUBLE; |
fa49fd0f | 590 | |
69ef87e2 AH |
591 | case CONST_VECTOR: |
592 | { | |
593 | int units; | |
594 | rtx elt; | |
595 | ||
596 | units = CONST_VECTOR_NUNITS (x); | |
597 | ||
598 | for (i = 0; i < units; ++i) | |
599 | { | |
600 | elt = CONST_VECTOR_ELT (x, i); | |
601 | hash += hash_rtx (elt, GET_MODE (elt), 0); | |
602 | } | |
603 | ||
604 | return hash; | |
605 | } | |
606 | ||
fa49fd0f RK |
607 | /* Assume there is only one rtx object for any given label. */ |
608 | case LABEL_REF: | |
609 | hash | |
610 | += ((unsigned) LABEL_REF << 7) + (unsigned long) XEXP (x, 0); | |
dc76f41c | 611 | return hash ? hash : (unsigned int) LABEL_REF; |
fa49fd0f RK |
612 | |
613 | case SYMBOL_REF: | |
614 | hash | |
615 | += ((unsigned) SYMBOL_REF << 7) + (unsigned long) XSTR (x, 0); | |
dc76f41c | 616 | return hash ? hash : (unsigned int) SYMBOL_REF; |
fa49fd0f RK |
617 | |
618 | case PRE_DEC: | |
619 | case PRE_INC: | |
620 | case POST_DEC: | |
621 | case POST_INC: | |
622 | case POST_MODIFY: | |
623 | case PRE_MODIFY: | |
624 | case PC: | |
625 | case CC0: | |
626 | case CALL: | |
627 | case UNSPEC_VOLATILE: | |
628 | return 0; | |
629 | ||
630 | case ASM_OPERANDS: | |
631 | if (MEM_VOLATILE_P (x)) | |
632 | return 0; | |
633 | ||
634 | break; | |
635 | ||
636 | default: | |
637 | break; | |
638 | } | |
639 | ||
640 | i = GET_RTX_LENGTH (code) - 1; | |
641 | fmt = GET_RTX_FORMAT (code); | |
642 | for (; i >= 0; i--) | |
643 | { | |
644 | if (fmt[i] == 'e') | |
645 | { | |
646 | rtx tem = XEXP (x, i); | |
669ff14e BS |
647 | unsigned int tem_hash = hash_rtx (tem, 0, create); |
648 | ||
fa49fd0f RK |
649 | if (tem_hash == 0) |
650 | return 0; | |
651 | ||
652 | hash += tem_hash; | |
653 | } | |
654 | else if (fmt[i] == 'E') | |
655 | for (j = 0; j < XVECLEN (x, i); j++) | |
656 | { | |
657 | unsigned int tem_hash = hash_rtx (XVECEXP (x, i, j), 0, create); | |
658 | ||
659 | if (tem_hash == 0) | |
660 | return 0; | |
661 | ||
662 | hash += tem_hash; | |
663 | } | |
664 | else if (fmt[i] == 's') | |
665 | { | |
666 | const unsigned char *p = (const unsigned char *) XSTR (x, i); | |
667 | ||
668 | if (p) | |
669 | while (*p) | |
670 | hash += *p++; | |
671 | } | |
672 | else if (fmt[i] == 'i') | |
673 | hash += XINT (x, i); | |
674 | else if (fmt[i] == '0' || fmt[i] == 't') | |
675 | /* unused */; | |
676 | else | |
677 | abort (); | |
678 | } | |
679 | ||
dc76f41c | 680 | return hash ? hash : 1 + (unsigned int) GET_CODE (x); |
fa49fd0f RK |
681 | } |
682 | ||
683 | /* Create a new value structure for VALUE and initialize it. The mode of the | |
684 | value is MODE. */ | |
685 | ||
686 | static cselib_val * | |
687 | new_cselib_val (value, mode) | |
688 | unsigned int value; | |
689 | enum machine_mode mode; | |
690 | { | |
691 | cselib_val *e = empty_vals; | |
692 | ||
693 | if (e) | |
694 | empty_vals = e->u.next_free; | |
695 | else | |
e2500fed | 696 | e = (cselib_val *) ggc_alloc (sizeof (cselib_val)); |
fa49fd0f RK |
697 | |
698 | if (value == 0) | |
699 | abort (); | |
700 | ||
701 | e->value = value; | |
702 | e->u.val_rtx = gen_rtx_VALUE (mode); | |
703 | CSELIB_VAL_PTR (e->u.val_rtx) = e; | |
704 | e->addr_list = 0; | |
705 | e->locs = 0; | |
706 | return e; | |
707 | } | |
708 | ||
709 | /* ADDR_ELT is a value that is used as address. MEM_ELT is the value that | |
710 | contains the data at this address. X is a MEM that represents the | |
711 | value. Update the two value structures to represent this situation. */ | |
712 | ||
713 | static void | |
714 | add_mem_for_addr (addr_elt, mem_elt, x) | |
715 | cselib_val *addr_elt, *mem_elt; | |
716 | rtx x; | |
717 | { | |
fa49fd0f RK |
718 | struct elt_loc_list *l; |
719 | ||
720 | /* Avoid duplicates. */ | |
721 | for (l = mem_elt->locs; l; l = l->next) | |
722 | if (GET_CODE (l->loc) == MEM | |
723 | && CSELIB_VAL_PTR (XEXP (l->loc, 0)) == addr_elt) | |
724 | return; | |
725 | ||
fa49fd0f | 726 | addr_elt->addr_list = new_elt_list (addr_elt->addr_list, mem_elt); |
f1ec5147 RK |
727 | mem_elt->locs |
728 | = new_elt_loc_list (mem_elt->locs, | |
729 | replace_equiv_address_nv (x, addr_elt->u.val_rtx)); | |
fa49fd0f RK |
730 | } |
731 | ||
732 | /* Subroutine of cselib_lookup. Return a value for X, which is a MEM rtx. | |
733 | If CREATE, make a new one if we haven't seen it before. */ | |
734 | ||
735 | static cselib_val * | |
736 | cselib_lookup_mem (x, create) | |
737 | rtx x; | |
738 | int create; | |
739 | { | |
740 | enum machine_mode mode = GET_MODE (x); | |
741 | void **slot; | |
742 | cselib_val *addr; | |
743 | cselib_val *mem_elt; | |
744 | struct elt_list *l; | |
745 | ||
746 | if (MEM_VOLATILE_P (x) || mode == BLKmode | |
747 | || (FLOAT_MODE_P (mode) && flag_float_store)) | |
748 | return 0; | |
749 | ||
750 | /* Look up the value for the address. */ | |
751 | addr = cselib_lookup (XEXP (x, 0), mode, create); | |
752 | if (! addr) | |
753 | return 0; | |
754 | ||
755 | /* Find a value that describes a value of our mode at that address. */ | |
756 | for (l = addr->addr_list; l; l = l->next) | |
757 | if (GET_MODE (l->elt->u.val_rtx) == mode) | |
758 | return l->elt; | |
759 | ||
760 | if (! create) | |
761 | return 0; | |
762 | ||
763 | mem_elt = new_cselib_val (++next_unknown_value, mode); | |
764 | add_mem_for_addr (addr, mem_elt, x); | |
765 | slot = htab_find_slot_with_hash (hash_table, wrap_constant (mode, x), | |
766 | mem_elt->value, INSERT); | |
767 | *slot = mem_elt; | |
768 | return mem_elt; | |
769 | } | |
770 | ||
771 | /* Walk rtx X and replace all occurrences of REG and MEM subexpressions | |
772 | with VALUE expressions. This way, it becomes independent of changes | |
773 | to registers and memory. | |
774 | X isn't actually modified; if modifications are needed, new rtl is | |
775 | allocated. However, the return value can share rtl with X. */ | |
776 | ||
91700444 | 777 | rtx |
fa49fd0f RK |
778 | cselib_subst_to_values (x) |
779 | rtx x; | |
780 | { | |
781 | enum rtx_code code = GET_CODE (x); | |
782 | const char *fmt = GET_RTX_FORMAT (code); | |
783 | cselib_val *e; | |
784 | struct elt_list *l; | |
785 | rtx copy = x; | |
786 | int i; | |
787 | ||
788 | switch (code) | |
789 | { | |
790 | case REG: | |
791 | for (l = REG_VALUES (REGNO (x)); l; l = l->next) | |
792 | if (GET_MODE (l->elt->u.val_rtx) == GET_MODE (x)) | |
793 | return l->elt->u.val_rtx; | |
794 | ||
795 | abort (); | |
796 | ||
797 | case MEM: | |
798 | e = cselib_lookup_mem (x, 0); | |
799 | if (! e) | |
91700444 BS |
800 | { |
801 | /* This happens for autoincrements. Assign a value that doesn't | |
802 | match any other. */ | |
803 | e = new_cselib_val (++next_unknown_value, GET_MODE (x)); | |
804 | } | |
fa49fd0f RK |
805 | return e->u.val_rtx; |
806 | ||
fa49fd0f | 807 | case CONST_DOUBLE: |
69ef87e2 | 808 | case CONST_VECTOR: |
fa49fd0f RK |
809 | case CONST_INT: |
810 | return x; | |
811 | ||
91700444 BS |
812 | case POST_INC: |
813 | case PRE_INC: | |
814 | case POST_DEC: | |
815 | case PRE_DEC: | |
816 | case POST_MODIFY: | |
817 | case PRE_MODIFY: | |
818 | e = new_cselib_val (++next_unknown_value, GET_MODE (x)); | |
819 | return e->u.val_rtx; | |
820 | ||
fa49fd0f RK |
821 | default: |
822 | break; | |
823 | } | |
824 | ||
825 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
826 | { | |
827 | if (fmt[i] == 'e') | |
828 | { | |
829 | rtx t = cselib_subst_to_values (XEXP (x, i)); | |
830 | ||
831 | if (t != XEXP (x, i) && x == copy) | |
832 | copy = shallow_copy_rtx (x); | |
833 | ||
834 | XEXP (copy, i) = t; | |
835 | } | |
836 | else if (fmt[i] == 'E') | |
837 | { | |
838 | int j, k; | |
839 | ||
840 | for (j = 0; j < XVECLEN (x, i); j++) | |
841 | { | |
842 | rtx t = cselib_subst_to_values (XVECEXP (x, i, j)); | |
843 | ||
844 | if (t != XVECEXP (x, i, j) && XVEC (x, i) == XVEC (copy, i)) | |
845 | { | |
846 | if (x == copy) | |
847 | copy = shallow_copy_rtx (x); | |
848 | ||
849 | XVEC (copy, i) = rtvec_alloc (XVECLEN (x, i)); | |
850 | for (k = 0; k < j; k++) | |
851 | XVECEXP (copy, i, k) = XVECEXP (x, i, k); | |
852 | } | |
853 | ||
854 | XVECEXP (copy, i, j) = t; | |
855 | } | |
856 | } | |
857 | } | |
858 | ||
859 | return copy; | |
860 | } | |
861 | ||
862 | /* Look up the rtl expression X in our tables and return the value it has. | |
863 | If CREATE is zero, we return NULL if we don't know the value. Otherwise, | |
864 | we create a new one if possible, using mode MODE if X doesn't have a mode | |
865 | (i.e. because it's a constant). */ | |
866 | ||
867 | cselib_val * | |
868 | cselib_lookup (x, mode, create) | |
869 | rtx x; | |
870 | enum machine_mode mode; | |
871 | int create; | |
872 | { | |
873 | void **slot; | |
874 | cselib_val *e; | |
875 | unsigned int hashval; | |
876 | ||
877 | if (GET_MODE (x) != VOIDmode) | |
878 | mode = GET_MODE (x); | |
879 | ||
880 | if (GET_CODE (x) == VALUE) | |
881 | return CSELIB_VAL_PTR (x); | |
882 | ||
883 | if (GET_CODE (x) == REG) | |
884 | { | |
885 | struct elt_list *l; | |
886 | unsigned int i = REGNO (x); | |
887 | ||
888 | for (l = REG_VALUES (i); l; l = l->next) | |
889 | if (mode == GET_MODE (l->elt->u.val_rtx)) | |
890 | return l->elt; | |
891 | ||
892 | if (! create) | |
893 | return 0; | |
894 | ||
31825e57 DM |
895 | if (i < FIRST_PSEUDO_REGISTER) |
896 | { | |
897 | unsigned int n = HARD_REGNO_NREGS (i, mode); | |
898 | ||
899 | if (n > max_value_regs) | |
900 | max_value_regs = n; | |
901 | } | |
902 | ||
fa49fd0f RK |
903 | e = new_cselib_val (++next_unknown_value, GET_MODE (x)); |
904 | e->locs = new_elt_loc_list (e->locs, x); | |
905 | if (REG_VALUES (i) == 0) | |
906 | VARRAY_PUSH_UINT (used_regs, i); | |
907 | REG_VALUES (i) = new_elt_list (REG_VALUES (i), e); | |
908 | slot = htab_find_slot_with_hash (hash_table, x, e->value, INSERT); | |
909 | *slot = e; | |
910 | return e; | |
911 | } | |
912 | ||
913 | if (GET_CODE (x) == MEM) | |
914 | return cselib_lookup_mem (x, create); | |
915 | ||
916 | hashval = hash_rtx (x, mode, create); | |
917 | /* Can't even create if hashing is not possible. */ | |
918 | if (! hashval) | |
919 | return 0; | |
920 | ||
921 | slot = htab_find_slot_with_hash (hash_table, wrap_constant (mode, x), | |
922 | hashval, create ? INSERT : NO_INSERT); | |
923 | if (slot == 0) | |
924 | return 0; | |
925 | ||
926 | e = (cselib_val *) *slot; | |
927 | if (e) | |
928 | return e; | |
929 | ||
930 | e = new_cselib_val (hashval, mode); | |
931 | ||
932 | /* We have to fill the slot before calling cselib_subst_to_values: | |
933 | the hash table is inconsistent until we do so, and | |
934 | cselib_subst_to_values will need to do lookups. */ | |
935 | *slot = (void *) e; | |
936 | e->locs = new_elt_loc_list (e->locs, cselib_subst_to_values (x)); | |
937 | return e; | |
938 | } | |
939 | ||
940 | /* Invalidate any entries in reg_values that overlap REGNO. This is called | |
941 | if REGNO is changing. MODE is the mode of the assignment to REGNO, which | |
942 | is used to determine how many hard registers are being changed. If MODE | |
943 | is VOIDmode, then only REGNO is being changed; this is used when | |
944 | invalidating call clobbered registers across a call. */ | |
945 | ||
946 | static void | |
947 | cselib_invalidate_regno (regno, mode) | |
948 | unsigned int regno; | |
949 | enum machine_mode mode; | |
950 | { | |
951 | unsigned int endregno; | |
952 | unsigned int i; | |
953 | ||
954 | /* If we see pseudos after reload, something is _wrong_. */ | |
955 | if (reload_completed && regno >= FIRST_PSEUDO_REGISTER | |
956 | && reg_renumber[regno] >= 0) | |
957 | abort (); | |
958 | ||
959 | /* Determine the range of registers that must be invalidated. For | |
960 | pseudos, only REGNO is affected. For hard regs, we must take MODE | |
961 | into account, and we must also invalidate lower register numbers | |
962 | if they contain values that overlap REGNO. */ | |
fa49fd0f | 963 | if (regno < FIRST_PSEUDO_REGISTER && mode != VOIDmode) |
31825e57 DM |
964 | { |
965 | if (regno < max_value_regs) | |
966 | i = 0; | |
967 | else | |
968 | i = regno - max_value_regs; | |
fa49fd0f | 969 | |
31825e57 DM |
970 | endregno = regno + HARD_REGNO_NREGS (regno, mode); |
971 | } | |
972 | else | |
973 | { | |
974 | i = regno; | |
975 | endregno = regno + 1; | |
976 | } | |
977 | ||
978 | for (; i < endregno; i++) | |
fa49fd0f RK |
979 | { |
980 | struct elt_list **l = ®_VALUES (i); | |
981 | ||
982 | /* Go through all known values for this reg; if it overlaps the range | |
983 | we're invalidating, remove the value. */ | |
984 | while (*l) | |
985 | { | |
986 | cselib_val *v = (*l)->elt; | |
987 | struct elt_loc_list **p; | |
988 | unsigned int this_last = i; | |
989 | ||
990 | if (i < FIRST_PSEUDO_REGISTER) | |
991 | this_last += HARD_REGNO_NREGS (i, GET_MODE (v->u.val_rtx)) - 1; | |
992 | ||
993 | if (this_last < regno) | |
994 | { | |
995 | l = &(*l)->next; | |
996 | continue; | |
997 | } | |
998 | ||
999 | /* We have an overlap. */ | |
1000 | unchain_one_elt_list (l); | |
1001 | ||
1002 | /* Now, we clear the mapping from value to reg. It must exist, so | |
1003 | this code will crash intentionally if it doesn't. */ | |
1004 | for (p = &v->locs; ; p = &(*p)->next) | |
1005 | { | |
1006 | rtx x = (*p)->loc; | |
1007 | ||
1008 | if (GET_CODE (x) == REG && REGNO (x) == i) | |
1009 | { | |
1010 | unchain_one_elt_loc_list (p); | |
1011 | break; | |
1012 | } | |
1013 | } | |
1014 | if (v->locs == 0) | |
1015 | n_useless_values++; | |
1016 | } | |
1017 | } | |
1018 | } | |
1019 | ||
1020 | /* The memory at address MEM_BASE is being changed. | |
1021 | Return whether this change will invalidate VAL. */ | |
1022 | ||
1023 | static int | |
1024 | cselib_mem_conflict_p (mem_base, val) | |
1025 | rtx mem_base; | |
1026 | rtx val; | |
1027 | { | |
1028 | enum rtx_code code; | |
1029 | const char *fmt; | |
1030 | int i, j; | |
1031 | ||
1032 | code = GET_CODE (val); | |
1033 | switch (code) | |
1034 | { | |
ec5c56db | 1035 | /* Get rid of a few simple cases quickly. */ |
fa49fd0f RK |
1036 | case REG: |
1037 | case PC: | |
1038 | case CC0: | |
1039 | case SCRATCH: | |
1040 | case CONST: | |
1041 | case CONST_INT: | |
1042 | case CONST_DOUBLE: | |
69ef87e2 | 1043 | case CONST_VECTOR: |
fa49fd0f RK |
1044 | case SYMBOL_REF: |
1045 | case LABEL_REF: | |
1046 | return 0; | |
1047 | ||
1048 | case MEM: | |
1049 | if (GET_MODE (mem_base) == BLKmode | |
1050 | || GET_MODE (val) == BLKmode | |
1051 | || anti_dependence (val, mem_base)) | |
1052 | return 1; | |
1053 | ||
1054 | /* The address may contain nested MEMs. */ | |
1055 | break; | |
1056 | ||
1057 | default: | |
1058 | break; | |
1059 | } | |
1060 | ||
1061 | fmt = GET_RTX_FORMAT (code); | |
1062 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
1063 | { | |
1064 | if (fmt[i] == 'e') | |
1065 | { | |
1066 | if (cselib_mem_conflict_p (mem_base, XEXP (val, i))) | |
1067 | return 1; | |
1068 | } | |
1069 | else if (fmt[i] == 'E') | |
1070 | for (j = 0; j < XVECLEN (val, i); j++) | |
1071 | if (cselib_mem_conflict_p (mem_base, XVECEXP (val, i, j))) | |
1072 | return 1; | |
1073 | } | |
1074 | ||
1075 | return 0; | |
1076 | } | |
1077 | ||
1078 | /* For the value found in SLOT, walk its locations to determine if any overlap | |
1079 | INFO (which is a MEM rtx). */ | |
1080 | ||
1081 | static int | |
1082 | cselib_invalidate_mem_1 (slot, info) | |
1083 | void **slot; | |
1084 | void *info; | |
1085 | { | |
1086 | cselib_val *v = (cselib_val *) *slot; | |
1087 | rtx mem_rtx = (rtx) info; | |
1088 | struct elt_loc_list **p = &v->locs; | |
1089 | int had_locs = v->locs != 0; | |
1090 | ||
1091 | while (*p) | |
1092 | { | |
1093 | rtx x = (*p)->loc; | |
1094 | cselib_val *addr; | |
1095 | struct elt_list **mem_chain; | |
1096 | ||
1097 | /* MEMs may occur in locations only at the top level; below | |
1098 | that every MEM or REG is substituted by its VALUE. */ | |
1099 | if (GET_CODE (x) != MEM | |
1100 | || ! cselib_mem_conflict_p (mem_rtx, x)) | |
1101 | { | |
1102 | p = &(*p)->next; | |
1103 | continue; | |
1104 | } | |
1105 | ||
1106 | /* This one overlaps. */ | |
1107 | /* We must have a mapping from this MEM's address to the | |
1108 | value (E). Remove that, too. */ | |
1109 | addr = cselib_lookup (XEXP (x, 0), VOIDmode, 0); | |
1110 | mem_chain = &addr->addr_list; | |
1111 | for (;;) | |
1112 | { | |
1113 | if ((*mem_chain)->elt == v) | |
1114 | { | |
1115 | unchain_one_elt_list (mem_chain); | |
1116 | break; | |
1117 | } | |
1118 | ||
1119 | mem_chain = &(*mem_chain)->next; | |
1120 | } | |
1121 | ||
1122 | unchain_one_elt_loc_list (p); | |
1123 | } | |
1124 | ||
1125 | if (had_locs && v->locs == 0) | |
1126 | n_useless_values++; | |
1127 | ||
1128 | return 1; | |
1129 | } | |
1130 | ||
1131 | /* Invalidate any locations in the table which are changed because of a | |
1132 | store to MEM_RTX. If this is called because of a non-const call | |
1133 | instruction, MEM_RTX is (mem:BLK const0_rtx). */ | |
1134 | ||
1135 | static void | |
1136 | cselib_invalidate_mem (mem_rtx) | |
1137 | rtx mem_rtx; | |
1138 | { | |
1139 | htab_traverse (hash_table, cselib_invalidate_mem_1, mem_rtx); | |
1140 | } | |
1141 | ||
1142 | /* Invalidate DEST, which is being assigned to or clobbered. The second and | |
1143 | the third parameter exist so that this function can be passed to | |
1144 | note_stores; they are ignored. */ | |
1145 | ||
1146 | static void | |
1147 | cselib_invalidate_rtx (dest, ignore, data) | |
1148 | rtx dest; | |
1149 | rtx ignore ATTRIBUTE_UNUSED; | |
1150 | void *data ATTRIBUTE_UNUSED; | |
1151 | { | |
1152 | while (GET_CODE (dest) == STRICT_LOW_PART || GET_CODE (dest) == SIGN_EXTRACT | |
1153 | || GET_CODE (dest) == ZERO_EXTRACT || GET_CODE (dest) == SUBREG) | |
1154 | dest = XEXP (dest, 0); | |
1155 | ||
1156 | if (GET_CODE (dest) == REG) | |
1157 | cselib_invalidate_regno (REGNO (dest), GET_MODE (dest)); | |
1158 | else if (GET_CODE (dest) == MEM) | |
1159 | cselib_invalidate_mem (dest); | |
1160 | ||
1161 | /* Some machines don't define AUTO_INC_DEC, but they still use push | |
1162 | instructions. We need to catch that case here in order to | |
1163 | invalidate the stack pointer correctly. Note that invalidating | |
1164 | the stack pointer is different from invalidating DEST. */ | |
1165 | if (push_operand (dest, GET_MODE (dest))) | |
1166 | cselib_invalidate_rtx (stack_pointer_rtx, NULL_RTX, NULL); | |
1167 | } | |
1168 | ||
1169 | /* Record the result of a SET instruction. DEST is being set; the source | |
1170 | contains the value described by SRC_ELT. If DEST is a MEM, DEST_ADDR_ELT | |
1171 | describes its address. */ | |
1172 | ||
1173 | static void | |
1174 | cselib_record_set (dest, src_elt, dest_addr_elt) | |
1175 | rtx dest; | |
1176 | cselib_val *src_elt, *dest_addr_elt; | |
1177 | { | |
1178 | int dreg = GET_CODE (dest) == REG ? (int) REGNO (dest) : -1; | |
1179 | ||
1180 | if (src_elt == 0 || side_effects_p (dest)) | |
1181 | return; | |
1182 | ||
1183 | if (dreg >= 0) | |
1184 | { | |
1185 | if (REG_VALUES (dreg) == 0) | |
1186 | VARRAY_PUSH_UINT (used_regs, dreg); | |
1187 | ||
31825e57 DM |
1188 | if (dreg < FIRST_PSEUDO_REGISTER) |
1189 | { | |
1190 | unsigned int n = HARD_REGNO_NREGS (dreg, GET_MODE (dest)); | |
1191 | ||
1192 | if (n > max_value_regs) | |
1193 | max_value_regs = n; | |
1194 | } | |
1195 | ||
fa49fd0f RK |
1196 | REG_VALUES (dreg) = new_elt_list (REG_VALUES (dreg), src_elt); |
1197 | if (src_elt->locs == 0) | |
1198 | n_useless_values--; | |
1199 | src_elt->locs = new_elt_loc_list (src_elt->locs, dest); | |
1200 | } | |
1201 | else if (GET_CODE (dest) == MEM && dest_addr_elt != 0) | |
1202 | { | |
1203 | if (src_elt->locs == 0) | |
1204 | n_useless_values--; | |
1205 | add_mem_for_addr (dest_addr_elt, src_elt, dest); | |
1206 | } | |
1207 | } | |
1208 | ||
1209 | /* Describe a single set that is part of an insn. */ | |
1210 | struct set | |
1211 | { | |
1212 | rtx src; | |
1213 | rtx dest; | |
1214 | cselib_val *src_elt; | |
1215 | cselib_val *dest_addr_elt; | |
1216 | }; | |
1217 | ||
1218 | /* There is no good way to determine how many elements there can be | |
1219 | in a PARALLEL. Since it's fairly cheap, use a really large number. */ | |
1220 | #define MAX_SETS (FIRST_PSEUDO_REGISTER * 2) | |
1221 | ||
1222 | /* Record the effects of any sets in INSN. */ | |
1223 | static void | |
1224 | cselib_record_sets (insn) | |
1225 | rtx insn; | |
1226 | { | |
1227 | int n_sets = 0; | |
1228 | int i; | |
1229 | struct set sets[MAX_SETS]; | |
1230 | rtx body = PATTERN (insn); | |
b7933c21 | 1231 | rtx cond = 0; |
fa49fd0f RK |
1232 | |
1233 | body = PATTERN (insn); | |
b7933c21 BS |
1234 | if (GET_CODE (body) == COND_EXEC) |
1235 | { | |
1236 | cond = COND_EXEC_TEST (body); | |
1237 | body = COND_EXEC_CODE (body); | |
1238 | } | |
1239 | ||
fa49fd0f RK |
1240 | /* Find all sets. */ |
1241 | if (GET_CODE (body) == SET) | |
1242 | { | |
1243 | sets[0].src = SET_SRC (body); | |
1244 | sets[0].dest = SET_DEST (body); | |
1245 | n_sets = 1; | |
1246 | } | |
1247 | else if (GET_CODE (body) == PARALLEL) | |
1248 | { | |
1249 | /* Look through the PARALLEL and record the values being | |
1250 | set, if possible. Also handle any CLOBBERs. */ | |
1251 | for (i = XVECLEN (body, 0) - 1; i >= 0; --i) | |
1252 | { | |
1253 | rtx x = XVECEXP (body, 0, i); | |
1254 | ||
1255 | if (GET_CODE (x) == SET) | |
1256 | { | |
1257 | sets[n_sets].src = SET_SRC (x); | |
1258 | sets[n_sets].dest = SET_DEST (x); | |
1259 | n_sets++; | |
1260 | } | |
1261 | } | |
1262 | } | |
1263 | ||
1264 | /* Look up the values that are read. Do this before invalidating the | |
1265 | locations that are written. */ | |
1266 | for (i = 0; i < n_sets; i++) | |
1267 | { | |
1268 | rtx dest = sets[i].dest; | |
1269 | ||
1270 | /* A STRICT_LOW_PART can be ignored; we'll record the equivalence for | |
1271 | the low part after invalidating any knowledge about larger modes. */ | |
1272 | if (GET_CODE (sets[i].dest) == STRICT_LOW_PART) | |
1273 | sets[i].dest = dest = XEXP (dest, 0); | |
1274 | ||
1275 | /* We don't know how to record anything but REG or MEM. */ | |
1276 | if (GET_CODE (dest) == REG || GET_CODE (dest) == MEM) | |
1277 | { | |
b7933c21 BS |
1278 | rtx src = sets[i].src; |
1279 | if (cond) | |
1280 | src = gen_rtx_IF_THEN_ELSE (GET_MODE (src), cond, src, dest); | |
37060e78 | 1281 | sets[i].src_elt = cselib_lookup (src, GET_MODE (dest), 1); |
fa49fd0f RK |
1282 | if (GET_CODE (dest) == MEM) |
1283 | sets[i].dest_addr_elt = cselib_lookup (XEXP (dest, 0), Pmode, 1); | |
1284 | else | |
1285 | sets[i].dest_addr_elt = 0; | |
1286 | } | |
1287 | } | |
1288 | ||
1289 | /* Invalidate all locations written by this insn. Note that the elts we | |
1290 | looked up in the previous loop aren't affected, just some of their | |
1291 | locations may go away. */ | |
1292 | note_stores (body, cselib_invalidate_rtx, NULL); | |
1293 | ||
1294 | /* Now enter the equivalences in our tables. */ | |
1295 | for (i = 0; i < n_sets; i++) | |
1296 | { | |
1297 | rtx dest = sets[i].dest; | |
1298 | if (GET_CODE (dest) == REG || GET_CODE (dest) == MEM) | |
1299 | cselib_record_set (dest, sets[i].src_elt, sets[i].dest_addr_elt); | |
1300 | } | |
1301 | } | |
1302 | ||
1303 | /* Record the effects of INSN. */ | |
1304 | ||
1305 | void | |
1306 | cselib_process_insn (insn) | |
1307 | rtx insn; | |
1308 | { | |
1309 | int i; | |
1310 | rtx x; | |
1311 | ||
1312 | cselib_current_insn = insn; | |
1313 | ||
1314 | /* Forget everything at a CODE_LABEL, a volatile asm, or a setjmp. */ | |
1315 | if (GET_CODE (insn) == CODE_LABEL | |
19652adf | 1316 | || (GET_CODE (insn) == CALL_INSN |
570a98eb | 1317 | && find_reg_note (insn, REG_SETJMP, NULL)) |
fa49fd0f RK |
1318 | || (GET_CODE (insn) == INSN |
1319 | && GET_CODE (PATTERN (insn)) == ASM_OPERANDS | |
1320 | && MEM_VOLATILE_P (PATTERN (insn)))) | |
1321 | { | |
1322 | clear_table (0); | |
1323 | return; | |
1324 | } | |
1325 | ||
1326 | if (! INSN_P (insn)) | |
1327 | { | |
1328 | cselib_current_insn = 0; | |
1329 | return; | |
1330 | } | |
1331 | ||
1332 | /* If this is a call instruction, forget anything stored in a | |
1333 | call clobbered register, or, if this is not a const call, in | |
1334 | memory. */ | |
1335 | if (GET_CODE (insn) == CALL_INSN) | |
1336 | { | |
1337 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
1338 | if (call_used_regs[i]) | |
1339 | cselib_invalidate_regno (i, VOIDmode); | |
1340 | ||
24a28584 | 1341 | if (! CONST_OR_PURE_CALL_P (insn)) |
fa49fd0f RK |
1342 | cselib_invalidate_mem (callmem); |
1343 | } | |
1344 | ||
1345 | cselib_record_sets (insn); | |
1346 | ||
1347 | #ifdef AUTO_INC_DEC | |
1348 | /* Clobber any registers which appear in REG_INC notes. We | |
1349 | could keep track of the changes to their values, but it is | |
1350 | unlikely to help. */ | |
1351 | for (x = REG_NOTES (insn); x; x = XEXP (x, 1)) | |
1352 | if (REG_NOTE_KIND (x) == REG_INC) | |
1353 | cselib_invalidate_rtx (XEXP (x, 0), NULL_RTX, NULL); | |
1354 | #endif | |
1355 | ||
1356 | /* Look for any CLOBBERs in CALL_INSN_FUNCTION_USAGE, but only | |
1357 | after we have processed the insn. */ | |
1358 | if (GET_CODE (insn) == CALL_INSN) | |
1359 | for (x = CALL_INSN_FUNCTION_USAGE (insn); x; x = XEXP (x, 1)) | |
1360 | if (GET_CODE (XEXP (x, 0)) == CLOBBER) | |
1361 | cselib_invalidate_rtx (XEXP (XEXP (x, 0), 0), NULL_RTX, NULL); | |
1362 | ||
1363 | cselib_current_insn = 0; | |
1364 | ||
1365 | if (n_useless_values > MAX_USELESS_VALUES) | |
1366 | remove_useless_values (); | |
1367 | } | |
1368 | ||
1369 | /* Make sure our varrays are big enough. Not called from any cselib routines; | |
1370 | it must be called by the user if it allocated new registers. */ | |
1371 | ||
1372 | void | |
1373 | cselib_update_varray_sizes () | |
1374 | { | |
1375 | unsigned int nregs = max_reg_num (); | |
1376 | ||
1377 | if (nregs == cselib_nregs) | |
1378 | return; | |
1379 | ||
1380 | cselib_nregs = nregs; | |
1381 | VARRAY_GROW (reg_values, nregs); | |
1382 | VARRAY_GROW (used_regs, nregs); | |
1383 | } | |
1384 | ||
1385 | /* Initialize cselib for one pass. The caller must also call | |
1386 | init_alias_analysis. */ | |
1387 | ||
1388 | void | |
1389 | cselib_init () | |
1390 | { | |
e2500fed | 1391 | /* This is only created once. */ |
fa49fd0f | 1392 | if (! callmem) |
e2500fed | 1393 | callmem = gen_rtx_MEM (BLKmode, const0_rtx); |
fa49fd0f RK |
1394 | |
1395 | cselib_nregs = max_reg_num (); | |
e2500fed GK |
1396 | if (reg_values_old != NULL && VARRAY_SIZE (reg_values_old) >= cselib_nregs) |
1397 | { | |
1398 | reg_values = reg_values_old; | |
1399 | used_regs = used_regs_old; | |
1400 | VARRAY_CLEAR (reg_values); | |
1401 | VARRAY_CLEAR (used_regs); | |
1402 | } | |
1403 | else | |
1404 | { | |
1405 | VARRAY_ELT_LIST_INIT (reg_values, cselib_nregs, "reg_values"); | |
1406 | VARRAY_UINT_INIT (used_regs, cselib_nregs, "used_regs"); | |
1407 | } | |
1408 | hash_table = htab_create_ggc (31, get_value_hash, entry_and_rtx_equal_p, | |
1409 | NULL); | |
fa49fd0f RK |
1410 | clear_table (1); |
1411 | } | |
1412 | ||
1413 | /* Called when the current user is done with cselib. */ | |
1414 | ||
1415 | void | |
1416 | cselib_finish () | |
1417 | { | |
e2500fed GK |
1418 | reg_values_old = reg_values; |
1419 | reg_values = 0; | |
1420 | used_regs_old = used_regs; | |
1421 | used_regs = 0; | |
1422 | hash_table = 0; | |
1423 | n_useless_values = 0; | |
1424 | next_unknown_value = 0; | |
fa49fd0f | 1425 | } |
e2500fed GK |
1426 | |
1427 | #include "gt-cselib.h" |