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1500f816 | 1 | /* Common subexpression elimination library for GNU compiler. |
2 | Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, | |
2b4876d2 | 3 | 1999, 2000, 2001, 2003, 2004, 2005 Free Software Foundation, Inc. |
1500f816 | 4 | |
f12b58b3 | 5 | This file is part of GCC. |
1500f816 | 6 | |
f12b58b3 | 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. | |
1500f816 | 11 | |
f12b58b3 | 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. | |
1500f816 | 16 | |
17 | You should have received a copy of the GNU General Public License | |
f12b58b3 | 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. */ | |
1500f816 | 21 | |
22 | #include "config.h" | |
23 | #include "system.h" | |
805e22b2 | 24 | #include "coretypes.h" |
25 | #include "tm.h" | |
1500f816 | 26 | |
27 | #include "rtl.h" | |
28 | #include "tm_p.h" | |
29 | #include "regs.h" | |
30 | #include "hard-reg-set.h" | |
31 | #include "flags.h" | |
32 | #include "real.h" | |
33 | #include "insn-config.h" | |
34 | #include "recog.h" | |
35 | #include "function.h" | |
4c74e6d9 | 36 | #include "emit-rtl.h" |
1500f816 | 37 | #include "toplev.h" |
38 | #include "output.h" | |
39 | #include "ggc.h" | |
1500f816 | 40 | #include "hashtab.h" |
41 | #include "cselib.h" | |
f391504c | 42 | #include "params.h" |
69d7e198 | 43 | #include "alloc-pool.h" |
1500f816 | 44 | |
53622482 | 45 | static bool cselib_record_memory; |
8ec3a57b | 46 | static int entry_and_rtx_equal_p (const void *, const void *); |
47 | static hashval_t get_value_hash (const void *); | |
48 | static struct elt_list *new_elt_list (struct elt_list *, cselib_val *); | |
49 | static struct elt_loc_list *new_elt_loc_list (struct elt_loc_list *, rtx); | |
50 | static void unchain_one_value (cselib_val *); | |
51 | static void unchain_one_elt_list (struct elt_list **); | |
52 | static void unchain_one_elt_loc_list (struct elt_loc_list **); | |
53 | static void clear_table (void); | |
54 | static int discard_useless_locs (void **, void *); | |
55 | static int discard_useless_values (void **, void *); | |
56 | static void remove_useless_values (void); | |
57 | static rtx wrap_constant (enum machine_mode, rtx); | |
78d140c9 | 58 | static unsigned int cselib_hash_rtx (rtx, enum machine_mode, int); |
8ec3a57b | 59 | static cselib_val *new_cselib_val (unsigned int, enum machine_mode); |
60 | static void add_mem_for_addr (cselib_val *, cselib_val *, rtx); | |
61 | static cselib_val *cselib_lookup_mem (rtx, int); | |
62 | static void cselib_invalidate_regno (unsigned int, enum machine_mode); | |
8ec3a57b | 63 | static void cselib_invalidate_mem (rtx); |
8ec3a57b | 64 | static void cselib_record_set (rtx, cselib_val *, cselib_val *); |
65 | static void cselib_record_sets (rtx); | |
1500f816 | 66 | |
67 | /* There are three ways in which cselib can look up an rtx: | |
68 | - for a REG, the reg_values table (which is indexed by regno) is used | |
69 | - for a MEM, we recursively look up its address and then follow the | |
70 | addr_list of that value | |
71 | - for everything else, we compute a hash value and go through the hash | |
72 | table. Since different rtx's can still have the same hash value, | |
73 | this involves walking the table entries for a given value and comparing | |
74 | the locations of the entries with the rtx we are looking up. */ | |
75 | ||
76 | /* A table that enables us to look up elts by their value. */ | |
fd910ba1 | 77 | static htab_t hash_table; |
1500f816 | 78 | |
79 | /* This is a global so we don't have to pass this through every function. | |
80 | It is used in new_elt_loc_list to set SETTING_INSN. */ | |
81 | static rtx cselib_current_insn; | |
8a98e28f | 82 | static bool cselib_current_insn_in_libcall; |
1500f816 | 83 | |
84 | /* Every new unknown value gets a unique number. */ | |
85 | static unsigned int next_unknown_value; | |
86 | ||
87 | /* The number of registers we had when the varrays were last resized. */ | |
88 | static unsigned int cselib_nregs; | |
89 | ||
90 | /* Count values without known locations. Whenever this grows too big, we | |
91 | remove these useless values from the table. */ | |
92 | static int n_useless_values; | |
93 | ||
94 | /* Number of useless values before we remove them from the hash table. */ | |
95 | #define MAX_USELESS_VALUES 32 | |
96 | ||
38a898c6 | 97 | /* This table maps from register number to values. It does not |
98 | contain pointers to cselib_val structures, but rather elt_lists. | |
99 | The purpose is to be able to refer to the same register in | |
100 | different modes. The first element of the list defines the mode in | |
101 | which the register was set; if the mode is unknown or the value is | |
102 | no longer valid in that mode, ELT will be NULL for the first | |
103 | element. */ | |
fd910ba1 | 104 | struct elt_list **reg_values; |
105 | unsigned int reg_values_size; | |
106 | #define REG_VALUES(i) reg_values[i] | |
1500f816 | 107 | |
362ed03f | 108 | /* The largest number of hard regs used by any entry added to the |
102502d4 | 109 | REG_VALUES table. Cleared on each clear_table() invocation. */ |
362ed03f | 110 | static unsigned int max_value_regs; |
111 | ||
1500f816 | 112 | /* Here the set of indices I with REG_VALUES(I) != 0 is saved. This is used |
113 | in clear_table() for fast emptying. */ | |
fd910ba1 | 114 | static unsigned int *used_regs; |
115 | static unsigned int n_used_regs; | |
1500f816 | 116 | |
117 | /* We pass this to cselib_invalidate_mem to invalidate all of | |
118 | memory for a non-const call instruction. */ | |
1f3233d1 | 119 | static GTY(()) rtx callmem; |
1500f816 | 120 | |
1500f816 | 121 | /* Set by discard_useless_locs if it deleted the last location of any |
122 | value. */ | |
123 | static int values_became_useless; | |
bb5b3af8 | 124 | |
125 | /* Used as stop element of the containing_mem list so we can check | |
126 | presence in the list by checking the next pointer. */ | |
127 | static cselib_val dummy_val; | |
128 | ||
8ec3a57b | 129 | /* Used to list all values that contain memory reference. |
bb5b3af8 | 130 | May or may not contain the useless values - the list is compacted |
131 | each time memory is invalidated. */ | |
132 | static cselib_val *first_containing_mem = &dummy_val; | |
c59b7e96 | 133 | static alloc_pool elt_loc_list_pool, elt_list_pool, cselib_val_pool, value_pool; |
1500f816 | 134 | \f |
135 | ||
136 | /* Allocate a struct elt_list and fill in its two elements with the | |
137 | arguments. */ | |
138 | ||
69d7e198 | 139 | static inline struct elt_list * |
8ec3a57b | 140 | new_elt_list (struct elt_list *next, cselib_val *elt) |
1500f816 | 141 | { |
69d7e198 | 142 | struct elt_list *el; |
143 | el = pool_alloc (elt_list_pool); | |
1500f816 | 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 | ||
69d7e198 | 152 | static inline struct elt_loc_list * |
8ec3a57b | 153 | new_elt_loc_list (struct elt_loc_list *next, rtx loc) |
1500f816 | 154 | { |
69d7e198 | 155 | struct elt_loc_list *el; |
156 | el = pool_alloc (elt_loc_list_pool); | |
1500f816 | 157 | el->next = next; |
158 | el->loc = loc; | |
159 | el->setting_insn = cselib_current_insn; | |
8a98e28f | 160 | el->in_libcall = cselib_current_insn_in_libcall; |
1500f816 | 161 | return el; |
162 | } | |
163 | ||
164 | /* The elt_list at *PL is no longer needed. Unchain it and free its | |
165 | storage. */ | |
166 | ||
69d7e198 | 167 | static inline void |
8ec3a57b | 168 | unchain_one_elt_list (struct elt_list **pl) |
1500f816 | 169 | { |
170 | struct elt_list *l = *pl; | |
171 | ||
172 | *pl = l->next; | |
69d7e198 | 173 | pool_free (elt_list_pool, l); |
1500f816 | 174 | } |
175 | ||
176 | /* Likewise for elt_loc_lists. */ | |
177 | ||
178 | static void | |
8ec3a57b | 179 | unchain_one_elt_loc_list (struct elt_loc_list **pl) |
1500f816 | 180 | { |
181 | struct elt_loc_list *l = *pl; | |
182 | ||
183 | *pl = l->next; | |
69d7e198 | 184 | pool_free (elt_loc_list_pool, l); |
1500f816 | 185 | } |
186 | ||
187 | /* Likewise for cselib_vals. This also frees the addr_list associated with | |
188 | V. */ | |
189 | ||
190 | static void | |
8ec3a57b | 191 | unchain_one_value (cselib_val *v) |
1500f816 | 192 | { |
193 | while (v->addr_list) | |
194 | unchain_one_elt_list (&v->addr_list); | |
195 | ||
69d7e198 | 196 | pool_free (cselib_val_pool, v); |
1500f816 | 197 | } |
198 | ||
199 | /* Remove all entries from the hash table. Also used during | |
200 | initialization. If CLEAR_ALL isn't set, then only clear the entries | |
201 | which are known to have been used. */ | |
202 | ||
203 | static void | |
8ec3a57b | 204 | clear_table (void) |
1500f816 | 205 | { |
206 | unsigned int i; | |
207 | ||
fd910ba1 | 208 | for (i = 0; i < n_used_regs; i++) |
209 | REG_VALUES (used_regs[i]) = 0; | |
1500f816 | 210 | |
362ed03f | 211 | max_value_regs = 0; |
212 | ||
fd910ba1 | 213 | n_used_regs = 0; |
1500f816 | 214 | |
215 | htab_empty (hash_table); | |
1500f816 | 216 | |
1500f816 | 217 | n_useless_values = 0; |
218 | ||
219 | next_unknown_value = 0; | |
bb5b3af8 | 220 | |
221 | first_containing_mem = &dummy_val; | |
1500f816 | 222 | } |
223 | ||
224 | /* The equality test for our hash table. The first argument ENTRY is a table | |
225 | element (i.e. a cselib_val), while the second arg X is an rtx. We know | |
226 | that all callers of htab_find_slot_with_hash will wrap CONST_INTs into a | |
227 | CONST of an appropriate mode. */ | |
228 | ||
229 | static int | |
8ec3a57b | 230 | entry_and_rtx_equal_p (const void *entry, const void *x_arg) |
1500f816 | 231 | { |
232 | struct elt_loc_list *l; | |
233 | const cselib_val *v = (const cselib_val *) entry; | |
234 | rtx x = (rtx) x_arg; | |
235 | enum machine_mode mode = GET_MODE (x); | |
236 | ||
cc636d56 | 237 | gcc_assert (GET_CODE (x) != CONST_INT |
238 | && (mode != VOIDmode || GET_CODE (x) != CONST_DOUBLE)); | |
239 | ||
1500f816 | 240 | if (mode != GET_MODE (v->u.val_rtx)) |
241 | return 0; | |
242 | ||
243 | /* Unwrap X if necessary. */ | |
244 | if (GET_CODE (x) == CONST | |
245 | && (GET_CODE (XEXP (x, 0)) == CONST_INT | |
246 | || GET_CODE (XEXP (x, 0)) == CONST_DOUBLE)) | |
247 | x = XEXP (x, 0); | |
8ec3a57b | 248 | |
1500f816 | 249 | /* We don't guarantee that distinct rtx's have different hash values, |
250 | so we need to do a comparison. */ | |
251 | for (l = v->locs; l; l = l->next) | |
252 | if (rtx_equal_for_cselib_p (l->loc, x)) | |
253 | return 1; | |
254 | ||
255 | return 0; | |
256 | } | |
257 | ||
258 | /* The hash function for our hash table. The value is always computed with | |
78d140c9 | 259 | cselib_hash_rtx when adding an element; this function just extracts the |
260 | hash value from a cselib_val structure. */ | |
1500f816 | 261 | |
aa77e59f | 262 | static hashval_t |
8ec3a57b | 263 | get_value_hash (const void *entry) |
1500f816 | 264 | { |
265 | const cselib_val *v = (const cselib_val *) entry; | |
266 | return v->value; | |
267 | } | |
268 | ||
269 | /* Return true if X contains a VALUE rtx. If ONLY_USELESS is set, we | |
270 | only return true for values which point to a cselib_val whose value | |
271 | element has been set to zero, which implies the cselib_val will be | |
272 | removed. */ | |
273 | ||
274 | int | |
8ec3a57b | 275 | references_value_p (rtx x, int only_useless) |
1500f816 | 276 | { |
277 | enum rtx_code code = GET_CODE (x); | |
278 | const char *fmt = GET_RTX_FORMAT (code); | |
279 | int i, j; | |
280 | ||
281 | if (GET_CODE (x) == VALUE | |
282 | && (! only_useless || CSELIB_VAL_PTR (x)->locs == 0)) | |
283 | return 1; | |
284 | ||
285 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
286 | { | |
287 | if (fmt[i] == 'e' && references_value_p (XEXP (x, i), only_useless)) | |
288 | return 1; | |
289 | else if (fmt[i] == 'E') | |
290 | for (j = 0; j < XVECLEN (x, i); j++) | |
291 | if (references_value_p (XVECEXP (x, i, j), only_useless)) | |
292 | return 1; | |
293 | } | |
294 | ||
295 | return 0; | |
296 | } | |
297 | ||
298 | /* For all locations found in X, delete locations that reference useless | |
299 | values (i.e. values without any location). Called through | |
300 | htab_traverse. */ | |
301 | ||
302 | static int | |
8ec3a57b | 303 | discard_useless_locs (void **x, void *info ATTRIBUTE_UNUSED) |
1500f816 | 304 | { |
305 | cselib_val *v = (cselib_val *)*x; | |
306 | struct elt_loc_list **p = &v->locs; | |
307 | int had_locs = v->locs != 0; | |
308 | ||
309 | while (*p) | |
310 | { | |
311 | if (references_value_p ((*p)->loc, 1)) | |
312 | unchain_one_elt_loc_list (p); | |
313 | else | |
314 | p = &(*p)->next; | |
315 | } | |
316 | ||
317 | if (had_locs && v->locs == 0) | |
318 | { | |
319 | n_useless_values++; | |
320 | values_became_useless = 1; | |
321 | } | |
322 | return 1; | |
323 | } | |
324 | ||
325 | /* If X is a value with no locations, remove it from the hashtable. */ | |
326 | ||
327 | static int | |
8ec3a57b | 328 | discard_useless_values (void **x, void *info ATTRIBUTE_UNUSED) |
1500f816 | 329 | { |
330 | cselib_val *v = (cselib_val *)*x; | |
331 | ||
332 | if (v->locs == 0) | |
333 | { | |
663fb689 | 334 | CSELIB_VAL_PTR (v->u.val_rtx) = NULL; |
1500f816 | 335 | htab_clear_slot (hash_table, x); |
336 | unchain_one_value (v); | |
337 | n_useless_values--; | |
338 | } | |
339 | ||
340 | return 1; | |
341 | } | |
342 | ||
343 | /* Clean out useless values (i.e. those which no longer have locations | |
344 | associated with them) from the hash table. */ | |
345 | ||
346 | static void | |
8ec3a57b | 347 | remove_useless_values (void) |
1500f816 | 348 | { |
bb5b3af8 | 349 | cselib_val **p, *v; |
1500f816 | 350 | /* First pass: eliminate locations that reference the value. That in |
351 | turn can make more values useless. */ | |
352 | do | |
353 | { | |
354 | values_became_useless = 0; | |
355 | htab_traverse (hash_table, discard_useless_locs, 0); | |
356 | } | |
357 | while (values_became_useless); | |
358 | ||
359 | /* Second pass: actually remove the values. */ | |
1500f816 | 360 | |
bb5b3af8 | 361 | p = &first_containing_mem; |
362 | for (v = *p; v != &dummy_val; v = v->next_containing_mem) | |
363 | if (v->locs) | |
364 | { | |
365 | *p = v; | |
366 | p = &(*p)->next_containing_mem; | |
367 | } | |
368 | *p = &dummy_val; | |
369 | ||
52bc1318 | 370 | htab_traverse (hash_table, discard_useless_values, 0); |
371 | ||
cc636d56 | 372 | gcc_assert (!n_useless_values); |
1500f816 | 373 | } |
374 | ||
38a898c6 | 375 | /* Return the mode in which a register was last set. If X is not a |
376 | register, return its mode. If the mode in which the register was | |
377 | set is not known, or the value was already clobbered, return | |
378 | VOIDmode. */ | |
379 | ||
380 | enum machine_mode | |
8ec3a57b | 381 | cselib_reg_set_mode (rtx x) |
38a898c6 | 382 | { |
8ad4c111 | 383 | if (!REG_P (x)) |
38a898c6 | 384 | return GET_MODE (x); |
385 | ||
386 | if (REG_VALUES (REGNO (x)) == NULL | |
387 | || REG_VALUES (REGNO (x))->elt == NULL) | |
388 | return VOIDmode; | |
389 | ||
390 | return GET_MODE (REG_VALUES (REGNO (x))->elt->u.val_rtx); | |
391 | } | |
392 | ||
1500f816 | 393 | /* Return nonzero if we can prove that X and Y contain the same value, taking |
394 | our gathered information into account. */ | |
395 | ||
396 | int | |
8ec3a57b | 397 | rtx_equal_for_cselib_p (rtx x, rtx y) |
1500f816 | 398 | { |
399 | enum rtx_code code; | |
400 | const char *fmt; | |
401 | int i; | |
8ec3a57b | 402 | |
8ad4c111 | 403 | if (REG_P (x) || MEM_P (x)) |
1500f816 | 404 | { |
405 | cselib_val *e = cselib_lookup (x, GET_MODE (x), 0); | |
406 | ||
407 | if (e) | |
408 | x = e->u.val_rtx; | |
409 | } | |
410 | ||
8ad4c111 | 411 | if (REG_P (y) || MEM_P (y)) |
1500f816 | 412 | { |
413 | cselib_val *e = cselib_lookup (y, GET_MODE (y), 0); | |
414 | ||
415 | if (e) | |
416 | y = e->u.val_rtx; | |
417 | } | |
418 | ||
419 | if (x == y) | |
420 | return 1; | |
421 | ||
422 | if (GET_CODE (x) == VALUE && GET_CODE (y) == VALUE) | |
423 | return CSELIB_VAL_PTR (x) == CSELIB_VAL_PTR (y); | |
424 | ||
425 | if (GET_CODE (x) == VALUE) | |
426 | { | |
427 | cselib_val *e = CSELIB_VAL_PTR (x); | |
428 | struct elt_loc_list *l; | |
429 | ||
430 | for (l = e->locs; l; l = l->next) | |
431 | { | |
432 | rtx t = l->loc; | |
433 | ||
434 | /* Avoid infinite recursion. */ | |
e16ceb8e | 435 | if (REG_P (t) || MEM_P (t)) |
1500f816 | 436 | continue; |
437 | else if (rtx_equal_for_cselib_p (t, y)) | |
438 | return 1; | |
439 | } | |
8ec3a57b | 440 | |
1500f816 | 441 | return 0; |
442 | } | |
443 | ||
444 | if (GET_CODE (y) == VALUE) | |
445 | { | |
446 | cselib_val *e = CSELIB_VAL_PTR (y); | |
447 | struct elt_loc_list *l; | |
448 | ||
449 | for (l = e->locs; l; l = l->next) | |
450 | { | |
451 | rtx t = l->loc; | |
452 | ||
e16ceb8e | 453 | if (REG_P (t) || MEM_P (t)) |
1500f816 | 454 | continue; |
455 | else if (rtx_equal_for_cselib_p (x, t)) | |
456 | return 1; | |
457 | } | |
8ec3a57b | 458 | |
1500f816 | 459 | return 0; |
460 | } | |
461 | ||
462 | if (GET_CODE (x) != GET_CODE (y) || GET_MODE (x) != GET_MODE (y)) | |
463 | return 0; | |
464 | ||
465 | /* This won't be handled correctly by the code below. */ | |
466 | if (GET_CODE (x) == LABEL_REF) | |
467 | return XEXP (x, 0) == XEXP (y, 0); | |
8ec3a57b | 468 | |
1500f816 | 469 | code = GET_CODE (x); |
470 | fmt = GET_RTX_FORMAT (code); | |
471 | ||
472 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
473 | { | |
474 | int j; | |
475 | ||
476 | switch (fmt[i]) | |
477 | { | |
478 | case 'w': | |
479 | if (XWINT (x, i) != XWINT (y, i)) | |
480 | return 0; | |
481 | break; | |
482 | ||
483 | case 'n': | |
484 | case 'i': | |
485 | if (XINT (x, i) != XINT (y, i)) | |
486 | return 0; | |
487 | break; | |
488 | ||
489 | case 'V': | |
490 | case 'E': | |
491 | /* Two vectors must have the same length. */ | |
492 | if (XVECLEN (x, i) != XVECLEN (y, i)) | |
493 | return 0; | |
494 | ||
495 | /* And the corresponding elements must match. */ | |
496 | for (j = 0; j < XVECLEN (x, i); j++) | |
497 | if (! rtx_equal_for_cselib_p (XVECEXP (x, i, j), | |
498 | XVECEXP (y, i, j))) | |
499 | return 0; | |
500 | break; | |
501 | ||
502 | case 'e': | |
503 | if (! rtx_equal_for_cselib_p (XEXP (x, i), XEXP (y, i))) | |
504 | return 0; | |
505 | break; | |
506 | ||
507 | case 'S': | |
508 | case 's': | |
509 | if (strcmp (XSTR (x, i), XSTR (y, i))) | |
510 | return 0; | |
511 | break; | |
512 | ||
513 | case 'u': | |
514 | /* These are just backpointers, so they don't matter. */ | |
515 | break; | |
516 | ||
517 | case '0': | |
518 | case 't': | |
519 | break; | |
520 | ||
521 | /* It is believed that rtx's at this level will never | |
522 | contain anything but integers and other rtx's, | |
523 | except for within LABEL_REFs and SYMBOL_REFs. */ | |
524 | default: | |
cc636d56 | 525 | gcc_unreachable (); |
1500f816 | 526 | } |
527 | } | |
528 | return 1; | |
529 | } | |
530 | ||
531 | /* We need to pass down the mode of constants through the hash table | |
532 | functions. For that purpose, wrap them in a CONST of the appropriate | |
533 | mode. */ | |
534 | static rtx | |
8ec3a57b | 535 | wrap_constant (enum machine_mode mode, rtx x) |
1500f816 | 536 | { |
537 | if (GET_CODE (x) != CONST_INT | |
538 | && (GET_CODE (x) != CONST_DOUBLE || GET_MODE (x) != VOIDmode)) | |
539 | return x; | |
cc636d56 | 540 | gcc_assert (mode != VOIDmode); |
1500f816 | 541 | return gen_rtx_CONST (mode, x); |
542 | } | |
543 | ||
544 | /* Hash an rtx. Return 0 if we couldn't hash the rtx. | |
545 | For registers and memory locations, we look up their cselib_val structure | |
546 | and return its VALUE element. | |
547 | Possible reasons for return 0 are: the object is volatile, or we couldn't | |
548 | find a register or memory location in the table and CREATE is zero. If | |
549 | CREATE is nonzero, table elts are created for regs and mem. | |
550 | MODE is used in hashing for CONST_INTs only; | |
551 | otherwise the mode of X is used. */ | |
552 | ||
553 | static unsigned int | |
78d140c9 | 554 | cselib_hash_rtx (rtx x, enum machine_mode mode, int create) |
1500f816 | 555 | { |
556 | cselib_val *e; | |
557 | int i, j; | |
558 | enum rtx_code code; | |
559 | const char *fmt; | |
560 | unsigned int hash = 0; | |
561 | ||
1500f816 | 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 | ||
66fa2987 | 573 | return e->value; |
1500f816 | 574 | |
575 | case CONST_INT: | |
576 | hash += ((unsigned) CONST_INT << 7) + (unsigned) mode + INTVAL (x); | |
6cf4241f | 577 | return hash ? hash : (unsigned int) CONST_INT; |
1500f816 | 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) | |
3393215f | 584 | hash += real_hash (CONST_DOUBLE_REAL_VALUE (x)); |
1500f816 | 585 | else |
586 | hash += ((unsigned) CONST_DOUBLE_LOW (x) | |
587 | + (unsigned) CONST_DOUBLE_HIGH (x)); | |
6cf4241f | 588 | return hash ? hash : (unsigned int) CONST_DOUBLE; |
1500f816 | 589 | |
886cfd4f | 590 | case CONST_VECTOR: |
591 | { | |
592 | int units; | |
593 | rtx elt; | |
594 | ||
595 | units = CONST_VECTOR_NUNITS (x); | |
596 | ||
597 | for (i = 0; i < units; ++i) | |
598 | { | |
599 | elt = CONST_VECTOR_ELT (x, i); | |
78d140c9 | 600 | hash += cselib_hash_rtx (elt, GET_MODE (elt), 0); |
886cfd4f | 601 | } |
602 | ||
603 | return hash; | |
604 | } | |
605 | ||
1500f816 | 606 | /* Assume there is only one rtx object for any given label. */ |
607 | case LABEL_REF: | |
608 | hash | |
609 | += ((unsigned) LABEL_REF << 7) + (unsigned long) XEXP (x, 0); | |
6cf4241f | 610 | return hash ? hash : (unsigned int) LABEL_REF; |
1500f816 | 611 | |
612 | case SYMBOL_REF: | |
613 | hash | |
614 | += ((unsigned) SYMBOL_REF << 7) + (unsigned long) XSTR (x, 0); | |
6cf4241f | 615 | return hash ? hash : (unsigned int) SYMBOL_REF; |
1500f816 | 616 | |
617 | case PRE_DEC: | |
618 | case PRE_INC: | |
619 | case POST_DEC: | |
620 | case POST_INC: | |
621 | case POST_MODIFY: | |
622 | case PRE_MODIFY: | |
623 | case PC: | |
624 | case CC0: | |
625 | case CALL: | |
626 | case UNSPEC_VOLATILE: | |
627 | return 0; | |
628 | ||
629 | case ASM_OPERANDS: | |
630 | if (MEM_VOLATILE_P (x)) | |
631 | return 0; | |
632 | ||
633 | break; | |
8ec3a57b | 634 | |
1500f816 | 635 | default: |
636 | break; | |
637 | } | |
638 | ||
639 | i = GET_RTX_LENGTH (code) - 1; | |
640 | fmt = GET_RTX_FORMAT (code); | |
641 | for (; i >= 0; i--) | |
642 | { | |
cc636d56 | 643 | switch (fmt[i]) |
1500f816 | 644 | { |
cc636d56 | 645 | case 'e': |
1500f816 | 646 | { |
cc636d56 | 647 | rtx tem = XEXP (x, i); |
648 | unsigned int tem_hash = cselib_hash_rtx (tem, 0, create); | |
649 | ||
1500f816 | 650 | if (tem_hash == 0) |
651 | return 0; | |
cc636d56 | 652 | |
1500f816 | 653 | hash += tem_hash; |
654 | } | |
cc636d56 | 655 | break; |
656 | case 'E': | |
657 | for (j = 0; j < XVECLEN (x, i); j++) | |
658 | { | |
659 | unsigned int tem_hash | |
660 | = cselib_hash_rtx (XVECEXP (x, i, j), 0, create); | |
661 | ||
662 | if (tem_hash == 0) | |
663 | return 0; | |
664 | ||
665 | hash += tem_hash; | |
666 | } | |
667 | break; | |
1500f816 | 668 | |
cc636d56 | 669 | case 's': |
670 | { | |
671 | const unsigned char *p = (const unsigned char *) XSTR (x, i); | |
672 | ||
673 | if (p) | |
674 | while (*p) | |
675 | hash += *p++; | |
676 | break; | |
677 | } | |
678 | ||
679 | case 'i': | |
680 | hash += XINT (x, i); | |
681 | break; | |
682 | ||
683 | case '0': | |
684 | case 't': | |
685 | /* unused */ | |
686 | break; | |
687 | ||
688 | default: | |
689 | gcc_unreachable (); | |
1500f816 | 690 | } |
1500f816 | 691 | } |
692 | ||
6cf4241f | 693 | return hash ? hash : 1 + (unsigned int) GET_CODE (x); |
1500f816 | 694 | } |
695 | ||
696 | /* Create a new value structure for VALUE and initialize it. The mode of the | |
697 | value is MODE. */ | |
698 | ||
69d7e198 | 699 | static inline cselib_val * |
8ec3a57b | 700 | new_cselib_val (unsigned int value, enum machine_mode mode) |
1500f816 | 701 | { |
69d7e198 | 702 | cselib_val *e = pool_alloc (cselib_val_pool); |
1500f816 | 703 | |
cc636d56 | 704 | gcc_assert (value); |
1500f816 | 705 | |
706 | e->value = value; | |
5bbaf5ca | 707 | /* We use an alloc pool to allocate this RTL construct because it |
708 | accounts for about 8% of the overall memory usage. We know | |
709 | precisely when we can have VALUE RTXen (when cselib is active) | |
10689255 | 710 | so we don't need to put them in garbage collected memory. |
5bbaf5ca | 711 | ??? Why should a VALUE be an RTX in the first place? */ |
c59b7e96 | 712 | e->u.val_rtx = pool_alloc (value_pool); |
713 | memset (e->u.val_rtx, 0, RTX_HDR_SIZE); | |
714 | PUT_CODE (e->u.val_rtx, VALUE); | |
715 | PUT_MODE (e->u.val_rtx, mode); | |
1500f816 | 716 | CSELIB_VAL_PTR (e->u.val_rtx) = e; |
717 | e->addr_list = 0; | |
718 | e->locs = 0; | |
bb5b3af8 | 719 | e->next_containing_mem = 0; |
1500f816 | 720 | return e; |
721 | } | |
722 | ||
723 | /* ADDR_ELT is a value that is used as address. MEM_ELT is the value that | |
724 | contains the data at this address. X is a MEM that represents the | |
725 | value. Update the two value structures to represent this situation. */ | |
726 | ||
727 | static void | |
8ec3a57b | 728 | add_mem_for_addr (cselib_val *addr_elt, cselib_val *mem_elt, rtx x) |
1500f816 | 729 | { |
1500f816 | 730 | struct elt_loc_list *l; |
731 | ||
732 | /* Avoid duplicates. */ | |
733 | for (l = mem_elt->locs; l; l = l->next) | |
e16ceb8e | 734 | if (MEM_P (l->loc) |
1500f816 | 735 | && CSELIB_VAL_PTR (XEXP (l->loc, 0)) == addr_elt) |
736 | return; | |
737 | ||
1500f816 | 738 | addr_elt->addr_list = new_elt_list (addr_elt->addr_list, mem_elt); |
e4e86ec5 | 739 | mem_elt->locs |
740 | = new_elt_loc_list (mem_elt->locs, | |
741 | replace_equiv_address_nv (x, addr_elt->u.val_rtx)); | |
bb5b3af8 | 742 | if (mem_elt->next_containing_mem == NULL) |
743 | { | |
744 | mem_elt->next_containing_mem = first_containing_mem; | |
745 | first_containing_mem = mem_elt; | |
746 | } | |
1500f816 | 747 | } |
748 | ||
749 | /* Subroutine of cselib_lookup. Return a value for X, which is a MEM rtx. | |
750 | If CREATE, make a new one if we haven't seen it before. */ | |
751 | ||
752 | static cselib_val * | |
8ec3a57b | 753 | cselib_lookup_mem (rtx x, int create) |
1500f816 | 754 | { |
755 | enum machine_mode mode = GET_MODE (x); | |
756 | void **slot; | |
757 | cselib_val *addr; | |
758 | cselib_val *mem_elt; | |
759 | struct elt_list *l; | |
760 | ||
761 | if (MEM_VOLATILE_P (x) || mode == BLKmode | |
53622482 | 762 | || !cselib_record_memory |
1500f816 | 763 | || (FLOAT_MODE_P (mode) && flag_float_store)) |
764 | return 0; | |
765 | ||
766 | /* Look up the value for the address. */ | |
767 | addr = cselib_lookup (XEXP (x, 0), mode, create); | |
768 | if (! addr) | |
769 | return 0; | |
770 | ||
771 | /* Find a value that describes a value of our mode at that address. */ | |
772 | for (l = addr->addr_list; l; l = l->next) | |
773 | if (GET_MODE (l->elt->u.val_rtx) == mode) | |
774 | return l->elt; | |
775 | ||
776 | if (! create) | |
777 | return 0; | |
778 | ||
779 | mem_elt = new_cselib_val (++next_unknown_value, mode); | |
780 | add_mem_for_addr (addr, mem_elt, x); | |
781 | slot = htab_find_slot_with_hash (hash_table, wrap_constant (mode, x), | |
782 | mem_elt->value, INSERT); | |
783 | *slot = mem_elt; | |
784 | return mem_elt; | |
785 | } | |
786 | ||
787 | /* Walk rtx X and replace all occurrences of REG and MEM subexpressions | |
788 | with VALUE expressions. This way, it becomes independent of changes | |
789 | to registers and memory. | |
790 | X isn't actually modified; if modifications are needed, new rtl is | |
791 | allocated. However, the return value can share rtl with X. */ | |
792 | ||
fdc1df6a | 793 | rtx |
8ec3a57b | 794 | cselib_subst_to_values (rtx x) |
1500f816 | 795 | { |
796 | enum rtx_code code = GET_CODE (x); | |
797 | const char *fmt = GET_RTX_FORMAT (code); | |
798 | cselib_val *e; | |
799 | struct elt_list *l; | |
800 | rtx copy = x; | |
801 | int i; | |
802 | ||
803 | switch (code) | |
804 | { | |
805 | case REG: | |
38a898c6 | 806 | l = REG_VALUES (REGNO (x)); |
807 | if (l && l->elt == NULL) | |
808 | l = l->next; | |
809 | for (; l; l = l->next) | |
1500f816 | 810 | if (GET_MODE (l->elt->u.val_rtx) == GET_MODE (x)) |
811 | return l->elt->u.val_rtx; | |
812 | ||
cc636d56 | 813 | gcc_unreachable (); |
1500f816 | 814 | |
815 | case MEM: | |
816 | e = cselib_lookup_mem (x, 0); | |
817 | if (! e) | |
fdc1df6a | 818 | { |
819 | /* This happens for autoincrements. Assign a value that doesn't | |
820 | match any other. */ | |
821 | e = new_cselib_val (++next_unknown_value, GET_MODE (x)); | |
822 | } | |
1500f816 | 823 | return e->u.val_rtx; |
824 | ||
1500f816 | 825 | case CONST_DOUBLE: |
886cfd4f | 826 | case CONST_VECTOR: |
1500f816 | 827 | case CONST_INT: |
828 | return x; | |
829 | ||
fdc1df6a | 830 | case POST_INC: |
831 | case PRE_INC: | |
832 | case POST_DEC: | |
833 | case PRE_DEC: | |
834 | case POST_MODIFY: | |
835 | case PRE_MODIFY: | |
836 | e = new_cselib_val (++next_unknown_value, GET_MODE (x)); | |
837 | return e->u.val_rtx; | |
8ec3a57b | 838 | |
1500f816 | 839 | default: |
840 | break; | |
841 | } | |
842 | ||
843 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
844 | { | |
845 | if (fmt[i] == 'e') | |
846 | { | |
847 | rtx t = cselib_subst_to_values (XEXP (x, i)); | |
848 | ||
849 | if (t != XEXP (x, i) && x == copy) | |
850 | copy = shallow_copy_rtx (x); | |
851 | ||
852 | XEXP (copy, i) = t; | |
853 | } | |
854 | else if (fmt[i] == 'E') | |
855 | { | |
856 | int j, k; | |
857 | ||
858 | for (j = 0; j < XVECLEN (x, i); j++) | |
859 | { | |
860 | rtx t = cselib_subst_to_values (XVECEXP (x, i, j)); | |
861 | ||
862 | if (t != XVECEXP (x, i, j) && XVEC (x, i) == XVEC (copy, i)) | |
863 | { | |
864 | if (x == copy) | |
865 | copy = shallow_copy_rtx (x); | |
866 | ||
867 | XVEC (copy, i) = rtvec_alloc (XVECLEN (x, i)); | |
868 | for (k = 0; k < j; k++) | |
869 | XVECEXP (copy, i, k) = XVECEXP (x, i, k); | |
870 | } | |
871 | ||
872 | XVECEXP (copy, i, j) = t; | |
873 | } | |
874 | } | |
875 | } | |
876 | ||
877 | return copy; | |
878 | } | |
879 | ||
880 | /* Look up the rtl expression X in our tables and return the value it has. | |
881 | If CREATE is zero, we return NULL if we don't know the value. Otherwise, | |
882 | we create a new one if possible, using mode MODE if X doesn't have a mode | |
883 | (i.e. because it's a constant). */ | |
884 | ||
885 | cselib_val * | |
8ec3a57b | 886 | cselib_lookup (rtx x, enum machine_mode mode, int create) |
1500f816 | 887 | { |
888 | void **slot; | |
889 | cselib_val *e; | |
890 | unsigned int hashval; | |
891 | ||
892 | if (GET_MODE (x) != VOIDmode) | |
893 | mode = GET_MODE (x); | |
894 | ||
895 | if (GET_CODE (x) == VALUE) | |
896 | return CSELIB_VAL_PTR (x); | |
897 | ||
8ad4c111 | 898 | if (REG_P (x)) |
1500f816 | 899 | { |
900 | struct elt_list *l; | |
901 | unsigned int i = REGNO (x); | |
902 | ||
38a898c6 | 903 | l = REG_VALUES (i); |
904 | if (l && l->elt == NULL) | |
905 | l = l->next; | |
906 | for (; l; l = l->next) | |
1500f816 | 907 | if (mode == GET_MODE (l->elt->u.val_rtx)) |
908 | return l->elt; | |
909 | ||
910 | if (! create) | |
911 | return 0; | |
912 | ||
362ed03f | 913 | if (i < FIRST_PSEUDO_REGISTER) |
914 | { | |
67d6c12b | 915 | unsigned int n = hard_regno_nregs[i][mode]; |
362ed03f | 916 | |
917 | if (n > max_value_regs) | |
918 | max_value_regs = n; | |
919 | } | |
920 | ||
1500f816 | 921 | e = new_cselib_val (++next_unknown_value, GET_MODE (x)); |
922 | e->locs = new_elt_loc_list (e->locs, x); | |
923 | if (REG_VALUES (i) == 0) | |
38a898c6 | 924 | { |
925 | /* Maintain the invariant that the first entry of | |
926 | REG_VALUES, if present, must be the value used to set the | |
927 | register, or NULL. */ | |
fd910ba1 | 928 | used_regs[n_used_regs++] = i; |
38a898c6 | 929 | REG_VALUES (i) = new_elt_list (REG_VALUES (i), NULL); |
930 | } | |
931 | REG_VALUES (i)->next = new_elt_list (REG_VALUES (i)->next, e); | |
1500f816 | 932 | slot = htab_find_slot_with_hash (hash_table, x, e->value, INSERT); |
933 | *slot = e; | |
934 | return e; | |
935 | } | |
936 | ||
e16ceb8e | 937 | if (MEM_P (x)) |
1500f816 | 938 | return cselib_lookup_mem (x, create); |
939 | ||
78d140c9 | 940 | hashval = cselib_hash_rtx (x, mode, create); |
1500f816 | 941 | /* Can't even create if hashing is not possible. */ |
942 | if (! hashval) | |
943 | return 0; | |
944 | ||
945 | slot = htab_find_slot_with_hash (hash_table, wrap_constant (mode, x), | |
946 | hashval, create ? INSERT : NO_INSERT); | |
947 | if (slot == 0) | |
948 | return 0; | |
949 | ||
950 | e = (cselib_val *) *slot; | |
951 | if (e) | |
952 | return e; | |
953 | ||
954 | e = new_cselib_val (hashval, mode); | |
955 | ||
956 | /* We have to fill the slot before calling cselib_subst_to_values: | |
957 | the hash table is inconsistent until we do so, and | |
958 | cselib_subst_to_values will need to do lookups. */ | |
959 | *slot = (void *) e; | |
960 | e->locs = new_elt_loc_list (e->locs, cselib_subst_to_values (x)); | |
961 | return e; | |
962 | } | |
963 | ||
964 | /* Invalidate any entries in reg_values that overlap REGNO. This is called | |
965 | if REGNO is changing. MODE is the mode of the assignment to REGNO, which | |
966 | is used to determine how many hard registers are being changed. If MODE | |
967 | is VOIDmode, then only REGNO is being changed; this is used when | |
968 | invalidating call clobbered registers across a call. */ | |
969 | ||
970 | static void | |
8ec3a57b | 971 | cselib_invalidate_regno (unsigned int regno, enum machine_mode mode) |
1500f816 | 972 | { |
973 | unsigned int endregno; | |
974 | unsigned int i; | |
975 | ||
976 | /* If we see pseudos after reload, something is _wrong_. */ | |
cc636d56 | 977 | gcc_assert (!reload_completed || regno < FIRST_PSEUDO_REGISTER |
978 | || reg_renumber[regno] < 0); | |
1500f816 | 979 | |
980 | /* Determine the range of registers that must be invalidated. For | |
981 | pseudos, only REGNO is affected. For hard regs, we must take MODE | |
982 | into account, and we must also invalidate lower register numbers | |
983 | if they contain values that overlap REGNO. */ | |
ff390ce4 | 984 | if (regno < FIRST_PSEUDO_REGISTER) |
362ed03f | 985 | { |
cc636d56 | 986 | gcc_assert (mode != VOIDmode); |
8ec3a57b | 987 | |
362ed03f | 988 | if (regno < max_value_regs) |
989 | i = 0; | |
990 | else | |
991 | i = regno - max_value_regs; | |
1500f816 | 992 | |
67d6c12b | 993 | endregno = regno + hard_regno_nregs[regno][mode]; |
362ed03f | 994 | } |
995 | else | |
996 | { | |
997 | i = regno; | |
998 | endregno = regno + 1; | |
999 | } | |
1000 | ||
1001 | for (; i < endregno; i++) | |
1500f816 | 1002 | { |
1003 | struct elt_list **l = ®_VALUES (i); | |
1004 | ||
1005 | /* Go through all known values for this reg; if it overlaps the range | |
1006 | we're invalidating, remove the value. */ | |
1007 | while (*l) | |
1008 | { | |
1009 | cselib_val *v = (*l)->elt; | |
1010 | struct elt_loc_list **p; | |
1011 | unsigned int this_last = i; | |
1012 | ||
38a898c6 | 1013 | if (i < FIRST_PSEUDO_REGISTER && v != NULL) |
67d6c12b | 1014 | this_last += hard_regno_nregs[i][GET_MODE (v->u.val_rtx)] - 1; |
1500f816 | 1015 | |
38a898c6 | 1016 | if (this_last < regno || v == NULL) |
1500f816 | 1017 | { |
1018 | l = &(*l)->next; | |
1019 | continue; | |
1020 | } | |
1021 | ||
1022 | /* We have an overlap. */ | |
38a898c6 | 1023 | if (*l == REG_VALUES (i)) |
1024 | { | |
1025 | /* Maintain the invariant that the first entry of | |
1026 | REG_VALUES, if present, must be the value used to set | |
1027 | the register, or NULL. This is also nice because | |
1028 | then we won't push the same regno onto user_regs | |
1029 | multiple times. */ | |
1030 | (*l)->elt = NULL; | |
1031 | l = &(*l)->next; | |
1032 | } | |
1033 | else | |
1034 | unchain_one_elt_list (l); | |
1500f816 | 1035 | |
1036 | /* Now, we clear the mapping from value to reg. It must exist, so | |
1037 | this code will crash intentionally if it doesn't. */ | |
1038 | for (p = &v->locs; ; p = &(*p)->next) | |
1039 | { | |
1040 | rtx x = (*p)->loc; | |
1041 | ||
8ad4c111 | 1042 | if (REG_P (x) && REGNO (x) == i) |
1500f816 | 1043 | { |
1044 | unchain_one_elt_loc_list (p); | |
1045 | break; | |
1046 | } | |
1047 | } | |
1048 | if (v->locs == 0) | |
1049 | n_useless_values++; | |
1050 | } | |
1051 | } | |
1052 | } | |
56bbdce4 | 1053 | \f |
1054 | /* Return 1 if X has a value that can vary even between two | |
1055 | executions of the program. 0 means X can be compared reliably | |
1056 | against certain constants or near-constants. */ | |
1500f816 | 1057 | |
1058 | static int | |
56bbdce4 | 1059 | cselib_rtx_varies_p (rtx x ATTRIBUTE_UNUSED, int from_alias ATTRIBUTE_UNUSED) |
1500f816 | 1060 | { |
56bbdce4 | 1061 | /* We actually don't need to verify very hard. This is because |
1062 | if X has actually changed, we invalidate the memory anyway, | |
1063 | so assume that all common memory addresses are | |
1064 | invariant. */ | |
1500f816 | 1065 | return 0; |
1066 | } | |
1067 | ||
bb5b3af8 | 1068 | /* Invalidate any locations in the table which are changed because of a |
1069 | store to MEM_RTX. If this is called because of a non-const call | |
1070 | instruction, MEM_RTX is (mem:BLK const0_rtx). */ | |
1500f816 | 1071 | |
bb5b3af8 | 1072 | static void |
8ec3a57b | 1073 | cselib_invalidate_mem (rtx mem_rtx) |
1500f816 | 1074 | { |
bb5b3af8 | 1075 | cselib_val **vp, *v, *next; |
f391504c | 1076 | int num_mems = 0; |
56bbdce4 | 1077 | rtx mem_addr; |
1078 | ||
1079 | mem_addr = canon_rtx (get_addr (XEXP (mem_rtx, 0))); | |
1080 | mem_rtx = canon_rtx (mem_rtx); | |
1500f816 | 1081 | |
bb5b3af8 | 1082 | vp = &first_containing_mem; |
1083 | for (v = *vp; v != &dummy_val; v = next) | |
1500f816 | 1084 | { |
bb5b3af8 | 1085 | bool has_mem = false; |
1086 | struct elt_loc_list **p = &v->locs; | |
1087 | int had_locs = v->locs != 0; | |
1500f816 | 1088 | |
bb5b3af8 | 1089 | while (*p) |
1500f816 | 1090 | { |
bb5b3af8 | 1091 | rtx x = (*p)->loc; |
1092 | cselib_val *addr; | |
1093 | struct elt_list **mem_chain; | |
1094 | ||
1095 | /* MEMs may occur in locations only at the top level; below | |
1096 | that every MEM or REG is substituted by its VALUE. */ | |
e16ceb8e | 1097 | if (!MEM_P (x)) |
1500f816 | 1098 | { |
bb5b3af8 | 1099 | p = &(*p)->next; |
1100 | continue; | |
1101 | } | |
f391504c | 1102 | if (num_mems < PARAM_VALUE (PARAM_MAX_CSELIB_MEMORY_LOCATIONS) |
56bbdce4 | 1103 | && ! canon_true_dependence (mem_rtx, GET_MODE (mem_rtx), mem_addr, |
1104 | x, cselib_rtx_varies_p)) | |
bb5b3af8 | 1105 | { |
1106 | has_mem = true; | |
f391504c | 1107 | num_mems++; |
bb5b3af8 | 1108 | p = &(*p)->next; |
1109 | continue; | |
1500f816 | 1110 | } |
1111 | ||
bb5b3af8 | 1112 | /* This one overlaps. */ |
1113 | /* We must have a mapping from this MEM's address to the | |
1114 | value (E). Remove that, too. */ | |
1115 | addr = cselib_lookup (XEXP (x, 0), VOIDmode, 0); | |
1116 | mem_chain = &addr->addr_list; | |
1117 | for (;;) | |
1118 | { | |
1119 | if ((*mem_chain)->elt == v) | |
1120 | { | |
1121 | unchain_one_elt_list (mem_chain); | |
1122 | break; | |
1123 | } | |
1500f816 | 1124 | |
bb5b3af8 | 1125 | mem_chain = &(*mem_chain)->next; |
1126 | } | |
1500f816 | 1127 | |
bb5b3af8 | 1128 | unchain_one_elt_loc_list (p); |
1129 | } | |
1500f816 | 1130 | |
bb5b3af8 | 1131 | if (had_locs && v->locs == 0) |
1132 | n_useless_values++; | |
1500f816 | 1133 | |
bb5b3af8 | 1134 | next = v->next_containing_mem; |
1135 | if (has_mem) | |
1136 | { | |
1137 | *vp = v; | |
1138 | vp = &(*vp)->next_containing_mem; | |
1139 | } | |
1140 | else | |
1141 | v->next_containing_mem = NULL; | |
1142 | } | |
1143 | *vp = &dummy_val; | |
1500f816 | 1144 | } |
1145 | ||
17883489 | 1146 | /* Invalidate DEST, which is being assigned to or clobbered. */ |
1500f816 | 1147 | |
17883489 | 1148 | void |
1149 | cselib_invalidate_rtx (rtx dest) | |
1500f816 | 1150 | { |
476d094d | 1151 | while (GET_CODE (dest) == SUBREG |
1152 | || GET_CODE (dest) == ZERO_EXTRACT | |
1153 | || GET_CODE (dest) == STRICT_LOW_PART) | |
1500f816 | 1154 | dest = XEXP (dest, 0); |
1155 | ||
8ad4c111 | 1156 | if (REG_P (dest)) |
1500f816 | 1157 | cselib_invalidate_regno (REGNO (dest), GET_MODE (dest)); |
e16ceb8e | 1158 | else if (MEM_P (dest)) |
1500f816 | 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))) | |
17883489 | 1166 | cselib_invalidate_rtx (stack_pointer_rtx); |
1167 | } | |
1168 | ||
1169 | /* A wrapper for cselib_invalidate_rtx to be called via note_stores. */ | |
1170 | ||
1171 | static void | |
1172 | cselib_invalidate_rtx_note_stores (rtx dest, rtx ignore ATTRIBUTE_UNUSED, | |
1173 | void *data ATTRIBUTE_UNUSED) | |
1174 | { | |
1175 | cselib_invalidate_rtx (dest); | |
1500f816 | 1176 | } |
1177 | ||
1178 | /* Record the result of a SET instruction. DEST is being set; the source | |
1179 | contains the value described by SRC_ELT. If DEST is a MEM, DEST_ADDR_ELT | |
1180 | describes its address. */ | |
1181 | ||
1182 | static void | |
8ec3a57b | 1183 | cselib_record_set (rtx dest, cselib_val *src_elt, cselib_val *dest_addr_elt) |
1500f816 | 1184 | { |
8ad4c111 | 1185 | int dreg = REG_P (dest) ? (int) REGNO (dest) : -1; |
1500f816 | 1186 | |
1187 | if (src_elt == 0 || side_effects_p (dest)) | |
1188 | return; | |
1189 | ||
1190 | if (dreg >= 0) | |
1191 | { | |
362ed03f | 1192 | if (dreg < FIRST_PSEUDO_REGISTER) |
1193 | { | |
67d6c12b | 1194 | unsigned int n = hard_regno_nregs[dreg][GET_MODE (dest)]; |
362ed03f | 1195 | |
1196 | if (n > max_value_regs) | |
1197 | max_value_regs = n; | |
1198 | } | |
1199 | ||
38a898c6 | 1200 | if (REG_VALUES (dreg) == 0) |
1201 | { | |
fd910ba1 | 1202 | used_regs[n_used_regs++] = dreg; |
38a898c6 | 1203 | REG_VALUES (dreg) = new_elt_list (REG_VALUES (dreg), src_elt); |
1204 | } | |
1205 | else | |
1206 | { | |
cc636d56 | 1207 | /* The register should have been invalidated. */ |
1208 | gcc_assert (REG_VALUES (dreg)->elt == 0); | |
1209 | REG_VALUES (dreg)->elt = src_elt; | |
38a898c6 | 1210 | } |
1211 | ||
1500f816 | 1212 | if (src_elt->locs == 0) |
1213 | n_useless_values--; | |
1214 | src_elt->locs = new_elt_loc_list (src_elt->locs, dest); | |
1215 | } | |
e16ceb8e | 1216 | else if (MEM_P (dest) && dest_addr_elt != 0 |
53622482 | 1217 | && cselib_record_memory) |
1500f816 | 1218 | { |
1219 | if (src_elt->locs == 0) | |
1220 | n_useless_values--; | |
1221 | add_mem_for_addr (dest_addr_elt, src_elt, dest); | |
1222 | } | |
1223 | } | |
1224 | ||
1225 | /* Describe a single set that is part of an insn. */ | |
1226 | struct set | |
1227 | { | |
1228 | rtx src; | |
1229 | rtx dest; | |
1230 | cselib_val *src_elt; | |
1231 | cselib_val *dest_addr_elt; | |
1232 | }; | |
1233 | ||
1234 | /* There is no good way to determine how many elements there can be | |
1235 | in a PARALLEL. Since it's fairly cheap, use a really large number. */ | |
1236 | #define MAX_SETS (FIRST_PSEUDO_REGISTER * 2) | |
1237 | ||
1238 | /* Record the effects of any sets in INSN. */ | |
1239 | static void | |
8ec3a57b | 1240 | cselib_record_sets (rtx insn) |
1500f816 | 1241 | { |
1242 | int n_sets = 0; | |
1243 | int i; | |
1244 | struct set sets[MAX_SETS]; | |
1245 | rtx body = PATTERN (insn); | |
e00aecfc | 1246 | rtx cond = 0; |
1500f816 | 1247 | |
1248 | body = PATTERN (insn); | |
e00aecfc | 1249 | if (GET_CODE (body) == COND_EXEC) |
1250 | { | |
1251 | cond = COND_EXEC_TEST (body); | |
1252 | body = COND_EXEC_CODE (body); | |
1253 | } | |
1254 | ||
1500f816 | 1255 | /* Find all sets. */ |
1256 | if (GET_CODE (body) == SET) | |
1257 | { | |
1258 | sets[0].src = SET_SRC (body); | |
1259 | sets[0].dest = SET_DEST (body); | |
1260 | n_sets = 1; | |
1261 | } | |
1262 | else if (GET_CODE (body) == PARALLEL) | |
1263 | { | |
1264 | /* Look through the PARALLEL and record the values being | |
1265 | set, if possible. Also handle any CLOBBERs. */ | |
1266 | for (i = XVECLEN (body, 0) - 1; i >= 0; --i) | |
1267 | { | |
1268 | rtx x = XVECEXP (body, 0, i); | |
1269 | ||
1270 | if (GET_CODE (x) == SET) | |
1271 | { | |
1272 | sets[n_sets].src = SET_SRC (x); | |
1273 | sets[n_sets].dest = SET_DEST (x); | |
1274 | n_sets++; | |
1275 | } | |
1276 | } | |
1277 | } | |
1278 | ||
1279 | /* Look up the values that are read. Do this before invalidating the | |
1280 | locations that are written. */ | |
1281 | for (i = 0; i < n_sets; i++) | |
1282 | { | |
1283 | rtx dest = sets[i].dest; | |
1284 | ||
1285 | /* A STRICT_LOW_PART can be ignored; we'll record the equivalence for | |
1286 | the low part after invalidating any knowledge about larger modes. */ | |
1287 | if (GET_CODE (sets[i].dest) == STRICT_LOW_PART) | |
1288 | sets[i].dest = dest = XEXP (dest, 0); | |
1289 | ||
1290 | /* We don't know how to record anything but REG or MEM. */ | |
8ad4c111 | 1291 | if (REG_P (dest) |
e16ceb8e | 1292 | || (MEM_P (dest) && cselib_record_memory)) |
1500f816 | 1293 | { |
e00aecfc | 1294 | rtx src = sets[i].src; |
1295 | if (cond) | |
1296 | src = gen_rtx_IF_THEN_ELSE (GET_MODE (src), cond, src, dest); | |
d0bfd0b5 | 1297 | sets[i].src_elt = cselib_lookup (src, GET_MODE (dest), 1); |
e16ceb8e | 1298 | if (MEM_P (dest)) |
1500f816 | 1299 | sets[i].dest_addr_elt = cselib_lookup (XEXP (dest, 0), Pmode, 1); |
1300 | else | |
1301 | sets[i].dest_addr_elt = 0; | |
1302 | } | |
1303 | } | |
1304 | ||
1305 | /* Invalidate all locations written by this insn. Note that the elts we | |
1306 | looked up in the previous loop aren't affected, just some of their | |
1307 | locations may go away. */ | |
17883489 | 1308 | note_stores (body, cselib_invalidate_rtx_note_stores, NULL); |
1500f816 | 1309 | |
332a71fa | 1310 | /* If this is an asm, look for duplicate sets. This can happen when the |
1311 | user uses the same value as an output multiple times. This is valid | |
1312 | if the outputs are not actually used thereafter. Treat this case as | |
1313 | if the value isn't actually set. We do this by smashing the destination | |
1314 | to pc_rtx, so that we won't record the value later. */ | |
1315 | if (n_sets >= 2 && asm_noperands (body) >= 0) | |
1316 | { | |
1317 | for (i = 0; i < n_sets; i++) | |
1318 | { | |
1319 | rtx dest = sets[i].dest; | |
e16ceb8e | 1320 | if (REG_P (dest) || MEM_P (dest)) |
332a71fa | 1321 | { |
1322 | int j; | |
1323 | for (j = i + 1; j < n_sets; j++) | |
1324 | if (rtx_equal_p (dest, sets[j].dest)) | |
1325 | { | |
1326 | sets[i].dest = pc_rtx; | |
1327 | sets[j].dest = pc_rtx; | |
1328 | } | |
1329 | } | |
1330 | } | |
1331 | } | |
1332 | ||
1500f816 | 1333 | /* Now enter the equivalences in our tables. */ |
1334 | for (i = 0; i < n_sets; i++) | |
1335 | { | |
1336 | rtx dest = sets[i].dest; | |
8ad4c111 | 1337 | if (REG_P (dest) |
e16ceb8e | 1338 | || (MEM_P (dest) && cselib_record_memory)) |
1500f816 | 1339 | cselib_record_set (dest, sets[i].src_elt, sets[i].dest_addr_elt); |
1340 | } | |
1341 | } | |
1342 | ||
1343 | /* Record the effects of INSN. */ | |
1344 | ||
1345 | void | |
8ec3a57b | 1346 | cselib_process_insn (rtx insn) |
1500f816 | 1347 | { |
1348 | int i; | |
1349 | rtx x; | |
1350 | ||
8a98e28f | 1351 | if (find_reg_note (insn, REG_LIBCALL, NULL)) |
1352 | cselib_current_insn_in_libcall = true; | |
1500f816 | 1353 | cselib_current_insn = insn; |
1354 | ||
1355 | /* Forget everything at a CODE_LABEL, a volatile asm, or a setjmp. */ | |
6d7dc5b9 | 1356 | if (LABEL_P (insn) |
1357 | || (CALL_P (insn) | |
9239aee6 | 1358 | && find_reg_note (insn, REG_SETJMP, NULL)) |
6d7dc5b9 | 1359 | || (NONJUMP_INSN_P (insn) |
1500f816 | 1360 | && GET_CODE (PATTERN (insn)) == ASM_OPERANDS |
1361 | && MEM_VOLATILE_P (PATTERN (insn)))) | |
1362 | { | |
9913d3a4 | 1363 | if (find_reg_note (insn, REG_RETVAL, NULL)) |
1364 | cselib_current_insn_in_libcall = false; | |
53fffe66 | 1365 | clear_table (); |
1500f816 | 1366 | return; |
1367 | } | |
1368 | ||
1369 | if (! INSN_P (insn)) | |
1370 | { | |
9913d3a4 | 1371 | if (find_reg_note (insn, REG_RETVAL, NULL)) |
1372 | cselib_current_insn_in_libcall = false; | |
1500f816 | 1373 | cselib_current_insn = 0; |
1374 | return; | |
1375 | } | |
1376 | ||
1377 | /* If this is a call instruction, forget anything stored in a | |
1378 | call clobbered register, or, if this is not a const call, in | |
1379 | memory. */ | |
6d7dc5b9 | 1380 | if (CALL_P (insn)) |
1500f816 | 1381 | { |
1382 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
1383 | if (call_used_regs[i]) | |
ff390ce4 | 1384 | cselib_invalidate_regno (i, reg_raw_mode[i]); |
1500f816 | 1385 | |
06a652d1 | 1386 | if (! CONST_OR_PURE_CALL_P (insn)) |
1500f816 | 1387 | cselib_invalidate_mem (callmem); |
1388 | } | |
1389 | ||
1390 | cselib_record_sets (insn); | |
1391 | ||
1392 | #ifdef AUTO_INC_DEC | |
1393 | /* Clobber any registers which appear in REG_INC notes. We | |
1394 | could keep track of the changes to their values, but it is | |
1395 | unlikely to help. */ | |
1396 | for (x = REG_NOTES (insn); x; x = XEXP (x, 1)) | |
1397 | if (REG_NOTE_KIND (x) == REG_INC) | |
17883489 | 1398 | cselib_invalidate_rtx (XEXP (x, 0)); |
1500f816 | 1399 | #endif |
1400 | ||
1401 | /* Look for any CLOBBERs in CALL_INSN_FUNCTION_USAGE, but only | |
1402 | after we have processed the insn. */ | |
6d7dc5b9 | 1403 | if (CALL_P (insn)) |
1500f816 | 1404 | for (x = CALL_INSN_FUNCTION_USAGE (insn); x; x = XEXP (x, 1)) |
1405 | if (GET_CODE (XEXP (x, 0)) == CLOBBER) | |
17883489 | 1406 | cselib_invalidate_rtx (XEXP (XEXP (x, 0), 0)); |
1500f816 | 1407 | |
9913d3a4 | 1408 | if (find_reg_note (insn, REG_RETVAL, NULL)) |
1409 | cselib_current_insn_in_libcall = false; | |
1500f816 | 1410 | cselib_current_insn = 0; |
1411 | ||
1412 | if (n_useless_values > MAX_USELESS_VALUES) | |
1413 | remove_useless_values (); | |
1414 | } | |
1415 | ||
1500f816 | 1416 | /* Initialize cselib for one pass. The caller must also call |
1417 | init_alias_analysis. */ | |
1418 | ||
1419 | void | |
53622482 | 1420 | cselib_init (bool record_memory) |
1500f816 | 1421 | { |
69d7e198 | 1422 | elt_list_pool = create_alloc_pool ("elt_list", |
1423 | sizeof (struct elt_list), 10); | |
1424 | elt_loc_list_pool = create_alloc_pool ("elt_loc_list", | |
1425 | sizeof (struct elt_loc_list), 10); | |
1426 | cselib_val_pool = create_alloc_pool ("cselib_val_list", | |
1427 | sizeof (cselib_val), 10); | |
c59b7e96 | 1428 | value_pool = create_alloc_pool ("value", |
1429 | RTX_SIZE (VALUE), 100); | |
53622482 | 1430 | cselib_record_memory = record_memory; |
1f3233d1 | 1431 | /* This is only created once. */ |
1500f816 | 1432 | if (! callmem) |
1f3233d1 | 1433 | callmem = gen_rtx_MEM (BLKmode, const0_rtx); |
1500f816 | 1434 | |
1435 | cselib_nregs = max_reg_num (); | |
fd910ba1 | 1436 | |
1437 | /* We preserve reg_values to allow expensive clearing of the whole thing. | |
1438 | Reallocate it however if it happens to be too large. */ | |
1439 | if (!reg_values || reg_values_size < cselib_nregs | |
1440 | || (reg_values_size > 10 && reg_values_size > cselib_nregs * 4)) | |
1f3233d1 | 1441 | { |
fd910ba1 | 1442 | if (reg_values) |
1443 | free (reg_values); | |
1444 | /* Some space for newly emit instructions so we don't end up | |
1445 | reallocating in between passes. */ | |
1446 | reg_values_size = cselib_nregs + (63 + cselib_nregs) / 16; | |
1447 | reg_values = xcalloc (reg_values_size, sizeof (reg_values)); | |
1f3233d1 | 1448 | } |
fd910ba1 | 1449 | used_regs = xmalloc (sizeof (*used_regs) * cselib_nregs); |
1450 | n_used_regs = 0; | |
1451 | hash_table = htab_create (31, get_value_hash, entry_and_rtx_equal_p, NULL); | |
8a98e28f | 1452 | cselib_current_insn_in_libcall = false; |
1500f816 | 1453 | } |
1454 | ||
1455 | /* Called when the current user is done with cselib. */ | |
1456 | ||
1457 | void | |
8ec3a57b | 1458 | cselib_finish (void) |
1500f816 | 1459 | { |
69d7e198 | 1460 | free_alloc_pool (elt_list_pool); |
1461 | free_alloc_pool (elt_loc_list_pool); | |
1462 | free_alloc_pool (cselib_val_pool); | |
c59b7e96 | 1463 | free_alloc_pool (value_pool); |
53fffe66 | 1464 | clear_table (); |
fd910ba1 | 1465 | htab_delete (hash_table); |
ce7efeed | 1466 | free (used_regs); |
1f3233d1 | 1467 | used_regs = 0; |
1468 | hash_table = 0; | |
1469 | n_useless_values = 0; | |
1470 | next_unknown_value = 0; | |
1500f816 | 1471 | } |
1f3233d1 | 1472 | |
1473 | #include "gt-cselib.h" |