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Commit | Line | Data |
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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, | |
ad616de1 | 3 | 1999, 2000, 2001, 2003, 2004, 2005 Free Software Foundation, Inc. |
fa49fd0f | 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 | 18 | along with GCC; see the file COPYING. If not, write to the Free |
366ccddb KC |
19 | Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA |
20 | 02110-1301, USA. */ | |
fa49fd0f RK |
21 | |
22 | #include "config.h" | |
23 | #include "system.h" | |
4977bab6 ZW |
24 | #include "coretypes.h" |
25 | #include "tm.h" | |
fa49fd0f RK |
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" | |
78528714 | 36 | #include "emit-rtl.h" |
fa49fd0f RK |
37 | #include "toplev.h" |
38 | #include "output.h" | |
39 | #include "ggc.h" | |
fa49fd0f RK |
40 | #include "hashtab.h" |
41 | #include "cselib.h" | |
c65ecebc | 42 | #include "params.h" |
6a59927d | 43 | #include "alloc-pool.h" |
fa49fd0f | 44 | |
463301c3 | 45 | static bool cselib_record_memory; |
7080f735 AJ |
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 **); | |
7080f735 AJ |
53 | static int discard_useless_locs (void **, void *); |
54 | static int discard_useless_values (void **, void *); | |
55 | static void remove_useless_values (void); | |
56 | static rtx wrap_constant (enum machine_mode, rtx); | |
0516f6fe | 57 | static unsigned int cselib_hash_rtx (rtx, enum machine_mode, int); |
7080f735 AJ |
58 | static cselib_val *new_cselib_val (unsigned int, enum machine_mode); |
59 | static void add_mem_for_addr (cselib_val *, cselib_val *, rtx); | |
60 | static cselib_val *cselib_lookup_mem (rtx, int); | |
61 | static void cselib_invalidate_regno (unsigned int, enum machine_mode); | |
7080f735 | 62 | static void cselib_invalidate_mem (rtx); |
7080f735 AJ |
63 | static void cselib_record_set (rtx, cselib_val *, cselib_val *); |
64 | static void cselib_record_sets (rtx); | |
fa49fd0f RK |
65 | |
66 | /* There are three ways in which cselib can look up an rtx: | |
67 | - for a REG, the reg_values table (which is indexed by regno) is used | |
68 | - for a MEM, we recursively look up its address and then follow the | |
69 | addr_list of that value | |
70 | - for everything else, we compute a hash value and go through the hash | |
71 | table. Since different rtx's can still have the same hash value, | |
72 | this involves walking the table entries for a given value and comparing | |
73 | the locations of the entries with the rtx we are looking up. */ | |
74 | ||
75 | /* A table that enables us to look up elts by their value. */ | |
6790d1ab | 76 | static htab_t hash_table; |
fa49fd0f RK |
77 | |
78 | /* This is a global so we don't have to pass this through every function. | |
79 | It is used in new_elt_loc_list to set SETTING_INSN. */ | |
80 | static rtx cselib_current_insn; | |
9635cfad | 81 | static bool cselib_current_insn_in_libcall; |
fa49fd0f RK |
82 | |
83 | /* Every new unknown value gets a unique number. */ | |
84 | static unsigned int next_unknown_value; | |
85 | ||
86 | /* The number of registers we had when the varrays were last resized. */ | |
87 | static unsigned int cselib_nregs; | |
88 | ||
89 | /* Count values without known locations. Whenever this grows too big, we | |
90 | remove these useless values from the table. */ | |
91 | static int n_useless_values; | |
92 | ||
93 | /* Number of useless values before we remove them from the hash table. */ | |
94 | #define MAX_USELESS_VALUES 32 | |
95 | ||
60fa6660 AO |
96 | /* This table maps from register number to values. It does not |
97 | contain pointers to cselib_val structures, but rather elt_lists. | |
98 | The purpose is to be able to refer to the same register in | |
99 | different modes. The first element of the list defines the mode in | |
100 | which the register was set; if the mode is unknown or the value is | |
101 | no longer valid in that mode, ELT will be NULL for the first | |
102 | element. */ | |
5211d65a KH |
103 | static struct elt_list **reg_values; |
104 | static unsigned int reg_values_size; | |
6790d1ab | 105 | #define REG_VALUES(i) reg_values[i] |
fa49fd0f | 106 | |
31825e57 | 107 | /* The largest number of hard regs used by any entry added to the |
eb232f4e | 108 | REG_VALUES table. Cleared on each cselib_clear_table() invocation. */ |
31825e57 DM |
109 | static unsigned int max_value_regs; |
110 | ||
fa49fd0f | 111 | /* Here the set of indices I with REG_VALUES(I) != 0 is saved. This is used |
eb232f4e | 112 | in cselib_clear_table() for fast emptying. */ |
6790d1ab JH |
113 | static unsigned int *used_regs; |
114 | static unsigned int n_used_regs; | |
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 | 119 | |
fa49fd0f RK |
120 | /* Set by discard_useless_locs if it deleted the last location of any |
121 | value. */ | |
122 | static int values_became_useless; | |
7101fb18 JH |
123 | |
124 | /* Used as stop element of the containing_mem list so we can check | |
125 | presence in the list by checking the next pointer. */ | |
126 | static cselib_val dummy_val; | |
127 | ||
7080f735 | 128 | /* Used to list all values that contain memory reference. |
7101fb18 JH |
129 | May or may not contain the useless values - the list is compacted |
130 | each time memory is invalidated. */ | |
131 | static cselib_val *first_containing_mem = &dummy_val; | |
23bd7a93 | 132 | static alloc_pool elt_loc_list_pool, elt_list_pool, cselib_val_pool, value_pool; |
fa49fd0f RK |
133 | \f |
134 | ||
135 | /* Allocate a struct elt_list and fill in its two elements with the | |
136 | arguments. */ | |
137 | ||
6a59927d | 138 | static inline struct elt_list * |
7080f735 | 139 | new_elt_list (struct elt_list *next, cselib_val *elt) |
fa49fd0f | 140 | { |
6a59927d JH |
141 | struct elt_list *el; |
142 | el = pool_alloc (elt_list_pool); | |
fa49fd0f RK |
143 | el->next = next; |
144 | el->elt = elt; | |
145 | return el; | |
146 | } | |
147 | ||
148 | /* Allocate a struct elt_loc_list and fill in its two elements with the | |
149 | arguments. */ | |
150 | ||
6a59927d | 151 | static inline struct elt_loc_list * |
7080f735 | 152 | new_elt_loc_list (struct elt_loc_list *next, rtx loc) |
fa49fd0f | 153 | { |
6a59927d JH |
154 | struct elt_loc_list *el; |
155 | el = pool_alloc (elt_loc_list_pool); | |
fa49fd0f RK |
156 | el->next = next; |
157 | el->loc = loc; | |
158 | el->setting_insn = cselib_current_insn; | |
9635cfad | 159 | el->in_libcall = cselib_current_insn_in_libcall; |
fa49fd0f RK |
160 | return el; |
161 | } | |
162 | ||
163 | /* The elt_list at *PL is no longer needed. Unchain it and free its | |
164 | storage. */ | |
165 | ||
6a59927d | 166 | static inline void |
7080f735 | 167 | unchain_one_elt_list (struct elt_list **pl) |
fa49fd0f RK |
168 | { |
169 | struct elt_list *l = *pl; | |
170 | ||
171 | *pl = l->next; | |
6a59927d | 172 | pool_free (elt_list_pool, l); |
fa49fd0f RK |
173 | } |
174 | ||
175 | /* Likewise for elt_loc_lists. */ | |
176 | ||
177 | static void | |
7080f735 | 178 | unchain_one_elt_loc_list (struct elt_loc_list **pl) |
fa49fd0f RK |
179 | { |
180 | struct elt_loc_list *l = *pl; | |
181 | ||
182 | *pl = l->next; | |
6a59927d | 183 | pool_free (elt_loc_list_pool, l); |
fa49fd0f RK |
184 | } |
185 | ||
186 | /* Likewise for cselib_vals. This also frees the addr_list associated with | |
187 | V. */ | |
188 | ||
189 | static void | |
7080f735 | 190 | unchain_one_value (cselib_val *v) |
fa49fd0f RK |
191 | { |
192 | while (v->addr_list) | |
193 | unchain_one_elt_list (&v->addr_list); | |
194 | ||
6a59927d | 195 | pool_free (cselib_val_pool, v); |
fa49fd0f RK |
196 | } |
197 | ||
198 | /* Remove all entries from the hash table. Also used during | |
199 | initialization. If CLEAR_ALL isn't set, then only clear the entries | |
200 | which are known to have been used. */ | |
201 | ||
eb232f4e SB |
202 | void |
203 | cselib_clear_table (void) | |
fa49fd0f RK |
204 | { |
205 | unsigned int i; | |
206 | ||
6790d1ab JH |
207 | for (i = 0; i < n_used_regs; i++) |
208 | REG_VALUES (used_regs[i]) = 0; | |
fa49fd0f | 209 | |
31825e57 DM |
210 | max_value_regs = 0; |
211 | ||
6790d1ab | 212 | n_used_regs = 0; |
fa49fd0f RK |
213 | |
214 | htab_empty (hash_table); | |
fa49fd0f | 215 | |
fa49fd0f RK |
216 | n_useless_values = 0; |
217 | ||
218 | next_unknown_value = 0; | |
7101fb18 JH |
219 | |
220 | first_containing_mem = &dummy_val; | |
fa49fd0f RK |
221 | } |
222 | ||
223 | /* The equality test for our hash table. The first argument ENTRY is a table | |
224 | element (i.e. a cselib_val), while the second arg X is an rtx. We know | |
225 | that all callers of htab_find_slot_with_hash will wrap CONST_INTs into a | |
226 | CONST of an appropriate mode. */ | |
227 | ||
228 | static int | |
7080f735 | 229 | entry_and_rtx_equal_p (const void *entry, const void *x_arg) |
fa49fd0f RK |
230 | { |
231 | struct elt_loc_list *l; | |
232 | const cselib_val *v = (const cselib_val *) entry; | |
233 | rtx x = (rtx) x_arg; | |
234 | enum machine_mode mode = GET_MODE (x); | |
235 | ||
341c100f NS |
236 | gcc_assert (GET_CODE (x) != CONST_INT |
237 | && (mode != VOIDmode || GET_CODE (x) != CONST_DOUBLE)); | |
238 | ||
fa49fd0f RK |
239 | if (mode != GET_MODE (v->u.val_rtx)) |
240 | return 0; | |
241 | ||
242 | /* Unwrap X if necessary. */ | |
243 | if (GET_CODE (x) == CONST | |
244 | && (GET_CODE (XEXP (x, 0)) == CONST_INT | |
245 | || GET_CODE (XEXP (x, 0)) == CONST_DOUBLE)) | |
246 | x = XEXP (x, 0); | |
7080f735 | 247 | |
fa49fd0f RK |
248 | /* We don't guarantee that distinct rtx's have different hash values, |
249 | so we need to do a comparison. */ | |
250 | for (l = v->locs; l; l = l->next) | |
251 | if (rtx_equal_for_cselib_p (l->loc, x)) | |
252 | return 1; | |
253 | ||
254 | return 0; | |
255 | } | |
256 | ||
257 | /* The hash function for our hash table. The value is always computed with | |
0516f6fe SB |
258 | cselib_hash_rtx when adding an element; this function just extracts the |
259 | hash value from a cselib_val structure. */ | |
fa49fd0f | 260 | |
fb7e6024 | 261 | static hashval_t |
7080f735 | 262 | get_value_hash (const void *entry) |
fa49fd0f RK |
263 | { |
264 | const cselib_val *v = (const cselib_val *) entry; | |
265 | return v->value; | |
266 | } | |
267 | ||
268 | /* Return true if X contains a VALUE rtx. If ONLY_USELESS is set, we | |
269 | only return true for values which point to a cselib_val whose value | |
270 | element has been set to zero, which implies the cselib_val will be | |
271 | removed. */ | |
272 | ||
273 | int | |
7080f735 | 274 | references_value_p (rtx x, int only_useless) |
fa49fd0f RK |
275 | { |
276 | enum rtx_code code = GET_CODE (x); | |
277 | const char *fmt = GET_RTX_FORMAT (code); | |
278 | int i, j; | |
279 | ||
280 | if (GET_CODE (x) == VALUE | |
281 | && (! only_useless || CSELIB_VAL_PTR (x)->locs == 0)) | |
282 | return 1; | |
283 | ||
284 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
285 | { | |
286 | if (fmt[i] == 'e' && references_value_p (XEXP (x, i), only_useless)) | |
287 | return 1; | |
288 | else if (fmt[i] == 'E') | |
289 | for (j = 0; j < XVECLEN (x, i); j++) | |
290 | if (references_value_p (XVECEXP (x, i, j), only_useless)) | |
291 | return 1; | |
292 | } | |
293 | ||
294 | return 0; | |
295 | } | |
296 | ||
297 | /* For all locations found in X, delete locations that reference useless | |
298 | values (i.e. values without any location). Called through | |
299 | htab_traverse. */ | |
300 | ||
301 | static int | |
7080f735 | 302 | discard_useless_locs (void **x, void *info ATTRIBUTE_UNUSED) |
fa49fd0f RK |
303 | { |
304 | cselib_val *v = (cselib_val *)*x; | |
305 | struct elt_loc_list **p = &v->locs; | |
306 | int had_locs = v->locs != 0; | |
307 | ||
308 | while (*p) | |
309 | { | |
310 | if (references_value_p ((*p)->loc, 1)) | |
311 | unchain_one_elt_loc_list (p); | |
312 | else | |
313 | p = &(*p)->next; | |
314 | } | |
315 | ||
316 | if (had_locs && v->locs == 0) | |
317 | { | |
318 | n_useless_values++; | |
319 | values_became_useless = 1; | |
320 | } | |
321 | return 1; | |
322 | } | |
323 | ||
324 | /* If X is a value with no locations, remove it from the hashtable. */ | |
325 | ||
326 | static int | |
7080f735 | 327 | discard_useless_values (void **x, void *info ATTRIBUTE_UNUSED) |
fa49fd0f RK |
328 | { |
329 | cselib_val *v = (cselib_val *)*x; | |
330 | ||
331 | if (v->locs == 0) | |
332 | { | |
18874af6 | 333 | CSELIB_VAL_PTR (v->u.val_rtx) = NULL; |
fa49fd0f RK |
334 | htab_clear_slot (hash_table, x); |
335 | unchain_one_value (v); | |
336 | n_useless_values--; | |
337 | } | |
338 | ||
339 | return 1; | |
340 | } | |
341 | ||
342 | /* Clean out useless values (i.e. those which no longer have locations | |
343 | associated with them) from the hash table. */ | |
344 | ||
345 | static void | |
7080f735 | 346 | remove_useless_values (void) |
fa49fd0f | 347 | { |
7101fb18 | 348 | cselib_val **p, *v; |
fa49fd0f RK |
349 | /* First pass: eliminate locations that reference the value. That in |
350 | turn can make more values useless. */ | |
351 | do | |
352 | { | |
353 | values_became_useless = 0; | |
354 | htab_traverse (hash_table, discard_useless_locs, 0); | |
355 | } | |
356 | while (values_became_useless); | |
357 | ||
358 | /* Second pass: actually remove the values. */ | |
fa49fd0f | 359 | |
7101fb18 JH |
360 | p = &first_containing_mem; |
361 | for (v = *p; v != &dummy_val; v = v->next_containing_mem) | |
362 | if (v->locs) | |
363 | { | |
364 | *p = v; | |
365 | p = &(*p)->next_containing_mem; | |
366 | } | |
367 | *p = &dummy_val; | |
368 | ||
3e2a0bd2 JH |
369 | htab_traverse (hash_table, discard_useless_values, 0); |
370 | ||
341c100f | 371 | gcc_assert (!n_useless_values); |
fa49fd0f RK |
372 | } |
373 | ||
60fa6660 AO |
374 | /* Return the mode in which a register was last set. If X is not a |
375 | register, return its mode. If the mode in which the register was | |
376 | set is not known, or the value was already clobbered, return | |
377 | VOIDmode. */ | |
378 | ||
379 | enum machine_mode | |
7080f735 | 380 | cselib_reg_set_mode (rtx x) |
60fa6660 | 381 | { |
f8cfc6aa | 382 | if (!REG_P (x)) |
60fa6660 AO |
383 | return GET_MODE (x); |
384 | ||
385 | if (REG_VALUES (REGNO (x)) == NULL | |
386 | || REG_VALUES (REGNO (x))->elt == NULL) | |
387 | return VOIDmode; | |
388 | ||
389 | return GET_MODE (REG_VALUES (REGNO (x))->elt->u.val_rtx); | |
390 | } | |
391 | ||
fa49fd0f RK |
392 | /* Return nonzero if we can prove that X and Y contain the same value, taking |
393 | our gathered information into account. */ | |
394 | ||
395 | int | |
7080f735 | 396 | rtx_equal_for_cselib_p (rtx x, rtx y) |
fa49fd0f RK |
397 | { |
398 | enum rtx_code code; | |
399 | const char *fmt; | |
400 | int i; | |
7080f735 | 401 | |
f8cfc6aa | 402 | if (REG_P (x) || MEM_P (x)) |
fa49fd0f RK |
403 | { |
404 | cselib_val *e = cselib_lookup (x, GET_MODE (x), 0); | |
405 | ||
406 | if (e) | |
407 | x = e->u.val_rtx; | |
408 | } | |
409 | ||
f8cfc6aa | 410 | if (REG_P (y) || MEM_P (y)) |
fa49fd0f RK |
411 | { |
412 | cselib_val *e = cselib_lookup (y, GET_MODE (y), 0); | |
413 | ||
414 | if (e) | |
415 | y = e->u.val_rtx; | |
416 | } | |
417 | ||
418 | if (x == y) | |
419 | return 1; | |
420 | ||
421 | if (GET_CODE (x) == VALUE && GET_CODE (y) == VALUE) | |
422 | return CSELIB_VAL_PTR (x) == CSELIB_VAL_PTR (y); | |
423 | ||
424 | if (GET_CODE (x) == VALUE) | |
425 | { | |
426 | cselib_val *e = CSELIB_VAL_PTR (x); | |
427 | struct elt_loc_list *l; | |
428 | ||
429 | for (l = e->locs; l; l = l->next) | |
430 | { | |
431 | rtx t = l->loc; | |
432 | ||
433 | /* Avoid infinite recursion. */ | |
3c0cb5de | 434 | if (REG_P (t) || MEM_P (t)) |
fa49fd0f RK |
435 | continue; |
436 | else if (rtx_equal_for_cselib_p (t, y)) | |
437 | return 1; | |
438 | } | |
7080f735 | 439 | |
fa49fd0f RK |
440 | return 0; |
441 | } | |
442 | ||
443 | if (GET_CODE (y) == VALUE) | |
444 | { | |
445 | cselib_val *e = CSELIB_VAL_PTR (y); | |
446 | struct elt_loc_list *l; | |
447 | ||
448 | for (l = e->locs; l; l = l->next) | |
449 | { | |
450 | rtx t = l->loc; | |
451 | ||
3c0cb5de | 452 | if (REG_P (t) || MEM_P (t)) |
fa49fd0f RK |
453 | continue; |
454 | else if (rtx_equal_for_cselib_p (x, t)) | |
455 | return 1; | |
456 | } | |
7080f735 | 457 | |
fa49fd0f RK |
458 | return 0; |
459 | } | |
460 | ||
461 | if (GET_CODE (x) != GET_CODE (y) || GET_MODE (x) != GET_MODE (y)) | |
462 | return 0; | |
463 | ||
464 | /* This won't be handled correctly by the code below. */ | |
465 | if (GET_CODE (x) == LABEL_REF) | |
466 | return XEXP (x, 0) == XEXP (y, 0); | |
7080f735 | 467 | |
fa49fd0f RK |
468 | code = GET_CODE (x); |
469 | fmt = GET_RTX_FORMAT (code); | |
470 | ||
471 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
472 | { | |
473 | int j; | |
474 | ||
475 | switch (fmt[i]) | |
476 | { | |
477 | case 'w': | |
478 | if (XWINT (x, i) != XWINT (y, i)) | |
479 | return 0; | |
480 | break; | |
481 | ||
482 | case 'n': | |
483 | case 'i': | |
484 | if (XINT (x, i) != XINT (y, i)) | |
485 | return 0; | |
486 | break; | |
487 | ||
488 | case 'V': | |
489 | case 'E': | |
490 | /* Two vectors must have the same length. */ | |
491 | if (XVECLEN (x, i) != XVECLEN (y, i)) | |
492 | return 0; | |
493 | ||
494 | /* And the corresponding elements must match. */ | |
495 | for (j = 0; j < XVECLEN (x, i); j++) | |
496 | if (! rtx_equal_for_cselib_p (XVECEXP (x, i, j), | |
497 | XVECEXP (y, i, j))) | |
498 | return 0; | |
499 | break; | |
500 | ||
501 | case 'e': | |
502 | if (! rtx_equal_for_cselib_p (XEXP (x, i), XEXP (y, i))) | |
503 | return 0; | |
504 | break; | |
505 | ||
506 | case 'S': | |
507 | case 's': | |
508 | if (strcmp (XSTR (x, i), XSTR (y, i))) | |
509 | return 0; | |
510 | break; | |
511 | ||
512 | case 'u': | |
513 | /* These are just backpointers, so they don't matter. */ | |
514 | break; | |
515 | ||
516 | case '0': | |
517 | case 't': | |
518 | break; | |
519 | ||
520 | /* It is believed that rtx's at this level will never | |
521 | contain anything but integers and other rtx's, | |
522 | except for within LABEL_REFs and SYMBOL_REFs. */ | |
523 | default: | |
341c100f | 524 | gcc_unreachable (); |
fa49fd0f RK |
525 | } |
526 | } | |
527 | return 1; | |
528 | } | |
529 | ||
530 | /* We need to pass down the mode of constants through the hash table | |
531 | functions. For that purpose, wrap them in a CONST of the appropriate | |
532 | mode. */ | |
533 | static rtx | |
7080f735 | 534 | wrap_constant (enum machine_mode mode, rtx x) |
fa49fd0f RK |
535 | { |
536 | if (GET_CODE (x) != CONST_INT | |
537 | && (GET_CODE (x) != CONST_DOUBLE || GET_MODE (x) != VOIDmode)) | |
538 | return x; | |
341c100f | 539 | gcc_assert (mode != VOIDmode); |
fa49fd0f RK |
540 | return gen_rtx_CONST (mode, x); |
541 | } | |
542 | ||
543 | /* Hash an rtx. Return 0 if we couldn't hash the rtx. | |
544 | For registers and memory locations, we look up their cselib_val structure | |
545 | and return its VALUE element. | |
546 | Possible reasons for return 0 are: the object is volatile, or we couldn't | |
547 | find a register or memory location in the table and CREATE is zero. If | |
548 | CREATE is nonzero, table elts are created for regs and mem. | |
549 | MODE is used in hashing for CONST_INTs only; | |
550 | otherwise the mode of X is used. */ | |
551 | ||
552 | static unsigned int | |
0516f6fe | 553 | cselib_hash_rtx (rtx x, enum machine_mode mode, int create) |
fa49fd0f RK |
554 | { |
555 | cselib_val *e; | |
556 | int i, j; | |
557 | enum rtx_code code; | |
558 | const char *fmt; | |
559 | unsigned int hash = 0; | |
560 | ||
fa49fd0f RK |
561 | code = GET_CODE (x); |
562 | hash += (unsigned) code + (unsigned) GET_MODE (x); | |
563 | ||
564 | switch (code) | |
565 | { | |
566 | case MEM: | |
567 | case REG: | |
568 | e = cselib_lookup (x, GET_MODE (x), create); | |
569 | if (! e) | |
570 | return 0; | |
571 | ||
a4f4333a | 572 | return e->value; |
fa49fd0f RK |
573 | |
574 | case CONST_INT: | |
575 | hash += ((unsigned) CONST_INT << 7) + (unsigned) mode + INTVAL (x); | |
dc76f41c | 576 | return hash ? hash : (unsigned int) CONST_INT; |
fa49fd0f RK |
577 | |
578 | case CONST_DOUBLE: | |
579 | /* This is like the general case, except that it only counts | |
580 | the integers representing the constant. */ | |
581 | hash += (unsigned) code + (unsigned) GET_MODE (x); | |
582 | if (GET_MODE (x) != VOIDmode) | |
46b33600 | 583 | hash += real_hash (CONST_DOUBLE_REAL_VALUE (x)); |
fa49fd0f RK |
584 | else |
585 | hash += ((unsigned) CONST_DOUBLE_LOW (x) | |
586 | + (unsigned) CONST_DOUBLE_HIGH (x)); | |
dc76f41c | 587 | return hash ? hash : (unsigned int) CONST_DOUBLE; |
fa49fd0f | 588 | |
69ef87e2 AH |
589 | case CONST_VECTOR: |
590 | { | |
591 | int units; | |
592 | rtx elt; | |
593 | ||
594 | units = CONST_VECTOR_NUNITS (x); | |
595 | ||
596 | for (i = 0; i < units; ++i) | |
597 | { | |
598 | elt = CONST_VECTOR_ELT (x, i); | |
0516f6fe | 599 | hash += cselib_hash_rtx (elt, GET_MODE (elt), 0); |
69ef87e2 AH |
600 | } |
601 | ||
602 | return hash; | |
603 | } | |
604 | ||
fa49fd0f RK |
605 | /* Assume there is only one rtx object for any given label. */ |
606 | case LABEL_REF: | |
607 | hash | |
608 | += ((unsigned) LABEL_REF << 7) + (unsigned long) XEXP (x, 0); | |
dc76f41c | 609 | return hash ? hash : (unsigned int) LABEL_REF; |
fa49fd0f RK |
610 | |
611 | case SYMBOL_REF: | |
612 | hash | |
613 | += ((unsigned) SYMBOL_REF << 7) + (unsigned long) XSTR (x, 0); | |
dc76f41c | 614 | return hash ? hash : (unsigned int) SYMBOL_REF; |
fa49fd0f RK |
615 | |
616 | case PRE_DEC: | |
617 | case PRE_INC: | |
618 | case POST_DEC: | |
619 | case POST_INC: | |
620 | case POST_MODIFY: | |
621 | case PRE_MODIFY: | |
622 | case PC: | |
623 | case CC0: | |
624 | case CALL: | |
625 | case UNSPEC_VOLATILE: | |
626 | return 0; | |
627 | ||
628 | case ASM_OPERANDS: | |
629 | if (MEM_VOLATILE_P (x)) | |
630 | return 0; | |
631 | ||
632 | break; | |
7080f735 | 633 | |
fa49fd0f RK |
634 | default: |
635 | break; | |
636 | } | |
637 | ||
638 | i = GET_RTX_LENGTH (code) - 1; | |
639 | fmt = GET_RTX_FORMAT (code); | |
640 | for (; i >= 0; i--) | |
641 | { | |
341c100f | 642 | switch (fmt[i]) |
fa49fd0f | 643 | { |
341c100f | 644 | case 'e': |
fa49fd0f | 645 | { |
341c100f NS |
646 | rtx tem = XEXP (x, i); |
647 | unsigned int tem_hash = cselib_hash_rtx (tem, 0, create); | |
648 | ||
fa49fd0f RK |
649 | if (tem_hash == 0) |
650 | return 0; | |
341c100f | 651 | |
fa49fd0f RK |
652 | hash += tem_hash; |
653 | } | |
341c100f NS |
654 | break; |
655 | case 'E': | |
656 | for (j = 0; j < XVECLEN (x, i); j++) | |
657 | { | |
658 | unsigned int tem_hash | |
659 | = cselib_hash_rtx (XVECEXP (x, i, j), 0, create); | |
660 | ||
661 | if (tem_hash == 0) | |
662 | return 0; | |
663 | ||
664 | hash += tem_hash; | |
665 | } | |
666 | break; | |
fa49fd0f | 667 | |
341c100f NS |
668 | case 's': |
669 | { | |
670 | const unsigned char *p = (const unsigned char *) XSTR (x, i); | |
671 | ||
672 | if (p) | |
673 | while (*p) | |
674 | hash += *p++; | |
675 | break; | |
676 | } | |
677 | ||
678 | case 'i': | |
679 | hash += XINT (x, i); | |
680 | break; | |
681 | ||
682 | case '0': | |
683 | case 't': | |
684 | /* unused */ | |
685 | break; | |
686 | ||
687 | default: | |
688 | gcc_unreachable (); | |
fa49fd0f | 689 | } |
fa49fd0f RK |
690 | } |
691 | ||
dc76f41c | 692 | return hash ? hash : 1 + (unsigned int) GET_CODE (x); |
fa49fd0f RK |
693 | } |
694 | ||
695 | /* Create a new value structure for VALUE and initialize it. The mode of the | |
696 | value is MODE. */ | |
697 | ||
6a59927d | 698 | static inline cselib_val * |
7080f735 | 699 | new_cselib_val (unsigned int value, enum machine_mode mode) |
fa49fd0f | 700 | { |
6a59927d | 701 | cselib_val *e = pool_alloc (cselib_val_pool); |
fa49fd0f | 702 | |
341c100f | 703 | gcc_assert (value); |
fa49fd0f RK |
704 | |
705 | e->value = value; | |
d67fb775 SB |
706 | /* We use an alloc pool to allocate this RTL construct because it |
707 | accounts for about 8% of the overall memory usage. We know | |
708 | precisely when we can have VALUE RTXen (when cselib is active) | |
daa956d0 | 709 | so we don't need to put them in garbage collected memory. |
d67fb775 | 710 | ??? Why should a VALUE be an RTX in the first place? */ |
23bd7a93 JH |
711 | e->u.val_rtx = pool_alloc (value_pool); |
712 | memset (e->u.val_rtx, 0, RTX_HDR_SIZE); | |
713 | PUT_CODE (e->u.val_rtx, VALUE); | |
714 | PUT_MODE (e->u.val_rtx, mode); | |
fa49fd0f RK |
715 | CSELIB_VAL_PTR (e->u.val_rtx) = e; |
716 | e->addr_list = 0; | |
717 | e->locs = 0; | |
7101fb18 | 718 | e->next_containing_mem = 0; |
fa49fd0f RK |
719 | return e; |
720 | } | |
721 | ||
722 | /* ADDR_ELT is a value that is used as address. MEM_ELT is the value that | |
723 | contains the data at this address. X is a MEM that represents the | |
724 | value. Update the two value structures to represent this situation. */ | |
725 | ||
726 | static void | |
7080f735 | 727 | add_mem_for_addr (cselib_val *addr_elt, cselib_val *mem_elt, rtx x) |
fa49fd0f | 728 | { |
fa49fd0f RK |
729 | struct elt_loc_list *l; |
730 | ||
731 | /* Avoid duplicates. */ | |
732 | for (l = mem_elt->locs; l; l = l->next) | |
3c0cb5de | 733 | if (MEM_P (l->loc) |
fa49fd0f RK |
734 | && CSELIB_VAL_PTR (XEXP (l->loc, 0)) == addr_elt) |
735 | return; | |
736 | ||
fa49fd0f | 737 | addr_elt->addr_list = new_elt_list (addr_elt->addr_list, mem_elt); |
f1ec5147 RK |
738 | mem_elt->locs |
739 | = new_elt_loc_list (mem_elt->locs, | |
740 | replace_equiv_address_nv (x, addr_elt->u.val_rtx)); | |
7101fb18 JH |
741 | if (mem_elt->next_containing_mem == NULL) |
742 | { | |
743 | mem_elt->next_containing_mem = first_containing_mem; | |
744 | first_containing_mem = mem_elt; | |
745 | } | |
fa49fd0f RK |
746 | } |
747 | ||
748 | /* Subroutine of cselib_lookup. Return a value for X, which is a MEM rtx. | |
749 | If CREATE, make a new one if we haven't seen it before. */ | |
750 | ||
751 | static cselib_val * | |
7080f735 | 752 | cselib_lookup_mem (rtx x, int create) |
fa49fd0f RK |
753 | { |
754 | enum machine_mode mode = GET_MODE (x); | |
755 | void **slot; | |
756 | cselib_val *addr; | |
757 | cselib_val *mem_elt; | |
758 | struct elt_list *l; | |
759 | ||
760 | if (MEM_VOLATILE_P (x) || mode == BLKmode | |
463301c3 | 761 | || !cselib_record_memory |
fa49fd0f RK |
762 | || (FLOAT_MODE_P (mode) && flag_float_store)) |
763 | return 0; | |
764 | ||
765 | /* Look up the value for the address. */ | |
766 | addr = cselib_lookup (XEXP (x, 0), mode, create); | |
767 | if (! addr) | |
768 | return 0; | |
769 | ||
770 | /* Find a value that describes a value of our mode at that address. */ | |
771 | for (l = addr->addr_list; l; l = l->next) | |
772 | if (GET_MODE (l->elt->u.val_rtx) == mode) | |
773 | return l->elt; | |
774 | ||
775 | if (! create) | |
776 | return 0; | |
777 | ||
778 | mem_elt = new_cselib_val (++next_unknown_value, mode); | |
779 | add_mem_for_addr (addr, mem_elt, x); | |
780 | slot = htab_find_slot_with_hash (hash_table, wrap_constant (mode, x), | |
781 | mem_elt->value, INSERT); | |
782 | *slot = mem_elt; | |
783 | return mem_elt; | |
784 | } | |
785 | ||
786 | /* Walk rtx X and replace all occurrences of REG and MEM subexpressions | |
787 | with VALUE expressions. This way, it becomes independent of changes | |
788 | to registers and memory. | |
789 | X isn't actually modified; if modifications are needed, new rtl is | |
790 | allocated. However, the return value can share rtl with X. */ | |
791 | ||
91700444 | 792 | rtx |
7080f735 | 793 | cselib_subst_to_values (rtx x) |
fa49fd0f RK |
794 | { |
795 | enum rtx_code code = GET_CODE (x); | |
796 | const char *fmt = GET_RTX_FORMAT (code); | |
797 | cselib_val *e; | |
798 | struct elt_list *l; | |
799 | rtx copy = x; | |
800 | int i; | |
801 | ||
802 | switch (code) | |
803 | { | |
804 | case REG: | |
60fa6660 AO |
805 | l = REG_VALUES (REGNO (x)); |
806 | if (l && l->elt == NULL) | |
807 | l = l->next; | |
808 | for (; l; l = l->next) | |
fa49fd0f RK |
809 | if (GET_MODE (l->elt->u.val_rtx) == GET_MODE (x)) |
810 | return l->elt->u.val_rtx; | |
811 | ||
341c100f | 812 | gcc_unreachable (); |
fa49fd0f RK |
813 | |
814 | case MEM: | |
815 | e = cselib_lookup_mem (x, 0); | |
816 | if (! e) | |
91700444 BS |
817 | { |
818 | /* This happens for autoincrements. Assign a value that doesn't | |
819 | match any other. */ | |
820 | e = new_cselib_val (++next_unknown_value, GET_MODE (x)); | |
821 | } | |
fa49fd0f RK |
822 | return e->u.val_rtx; |
823 | ||
fa49fd0f | 824 | case CONST_DOUBLE: |
69ef87e2 | 825 | case CONST_VECTOR: |
fa49fd0f RK |
826 | case CONST_INT: |
827 | return x; | |
828 | ||
91700444 BS |
829 | case POST_INC: |
830 | case PRE_INC: | |
831 | case POST_DEC: | |
832 | case PRE_DEC: | |
833 | case POST_MODIFY: | |
834 | case PRE_MODIFY: | |
835 | e = new_cselib_val (++next_unknown_value, GET_MODE (x)); | |
836 | return e->u.val_rtx; | |
7080f735 | 837 | |
fa49fd0f RK |
838 | default: |
839 | break; | |
840 | } | |
841 | ||
842 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
843 | { | |
844 | if (fmt[i] == 'e') | |
845 | { | |
846 | rtx t = cselib_subst_to_values (XEXP (x, i)); | |
847 | ||
848 | if (t != XEXP (x, i) && x == copy) | |
849 | copy = shallow_copy_rtx (x); | |
850 | ||
851 | XEXP (copy, i) = t; | |
852 | } | |
853 | else if (fmt[i] == 'E') | |
854 | { | |
855 | int j, k; | |
856 | ||
857 | for (j = 0; j < XVECLEN (x, i); j++) | |
858 | { | |
859 | rtx t = cselib_subst_to_values (XVECEXP (x, i, j)); | |
860 | ||
861 | if (t != XVECEXP (x, i, j) && XVEC (x, i) == XVEC (copy, i)) | |
862 | { | |
863 | if (x == copy) | |
864 | copy = shallow_copy_rtx (x); | |
865 | ||
866 | XVEC (copy, i) = rtvec_alloc (XVECLEN (x, i)); | |
867 | for (k = 0; k < j; k++) | |
868 | XVECEXP (copy, i, k) = XVECEXP (x, i, k); | |
869 | } | |
870 | ||
871 | XVECEXP (copy, i, j) = t; | |
872 | } | |
873 | } | |
874 | } | |
875 | ||
876 | return copy; | |
877 | } | |
878 | ||
879 | /* Look up the rtl expression X in our tables and return the value it has. | |
880 | If CREATE is zero, we return NULL if we don't know the value. Otherwise, | |
881 | we create a new one if possible, using mode MODE if X doesn't have a mode | |
882 | (i.e. because it's a constant). */ | |
883 | ||
884 | cselib_val * | |
7080f735 | 885 | cselib_lookup (rtx x, enum machine_mode mode, int create) |
fa49fd0f RK |
886 | { |
887 | void **slot; | |
888 | cselib_val *e; | |
889 | unsigned int hashval; | |
890 | ||
891 | if (GET_MODE (x) != VOIDmode) | |
892 | mode = GET_MODE (x); | |
893 | ||
894 | if (GET_CODE (x) == VALUE) | |
895 | return CSELIB_VAL_PTR (x); | |
896 | ||
f8cfc6aa | 897 | if (REG_P (x)) |
fa49fd0f RK |
898 | { |
899 | struct elt_list *l; | |
900 | unsigned int i = REGNO (x); | |
901 | ||
60fa6660 AO |
902 | l = REG_VALUES (i); |
903 | if (l && l->elt == NULL) | |
904 | l = l->next; | |
905 | for (; l; l = l->next) | |
fa49fd0f RK |
906 | if (mode == GET_MODE (l->elt->u.val_rtx)) |
907 | return l->elt; | |
908 | ||
909 | if (! create) | |
910 | return 0; | |
911 | ||
31825e57 DM |
912 | if (i < FIRST_PSEUDO_REGISTER) |
913 | { | |
66fd46b6 | 914 | unsigned int n = hard_regno_nregs[i][mode]; |
31825e57 DM |
915 | |
916 | if (n > max_value_regs) | |
917 | max_value_regs = n; | |
918 | } | |
919 | ||
fa49fd0f RK |
920 | e = new_cselib_val (++next_unknown_value, GET_MODE (x)); |
921 | e->locs = new_elt_loc_list (e->locs, x); | |
922 | if (REG_VALUES (i) == 0) | |
60fa6660 AO |
923 | { |
924 | /* Maintain the invariant that the first entry of | |
925 | REG_VALUES, if present, must be the value used to set the | |
926 | register, or NULL. */ | |
6790d1ab | 927 | used_regs[n_used_regs++] = i; |
60fa6660 AO |
928 | REG_VALUES (i) = new_elt_list (REG_VALUES (i), NULL); |
929 | } | |
930 | REG_VALUES (i)->next = new_elt_list (REG_VALUES (i)->next, e); | |
fa49fd0f RK |
931 | slot = htab_find_slot_with_hash (hash_table, x, e->value, INSERT); |
932 | *slot = e; | |
933 | return e; | |
934 | } | |
935 | ||
3c0cb5de | 936 | if (MEM_P (x)) |
fa49fd0f RK |
937 | return cselib_lookup_mem (x, create); |
938 | ||
0516f6fe | 939 | hashval = cselib_hash_rtx (x, mode, create); |
fa49fd0f RK |
940 | /* Can't even create if hashing is not possible. */ |
941 | if (! hashval) | |
942 | return 0; | |
943 | ||
944 | slot = htab_find_slot_with_hash (hash_table, wrap_constant (mode, x), | |
945 | hashval, create ? INSERT : NO_INSERT); | |
946 | if (slot == 0) | |
947 | return 0; | |
948 | ||
949 | e = (cselib_val *) *slot; | |
950 | if (e) | |
951 | return e; | |
952 | ||
953 | e = new_cselib_val (hashval, mode); | |
954 | ||
955 | /* We have to fill the slot before calling cselib_subst_to_values: | |
956 | the hash table is inconsistent until we do so, and | |
957 | cselib_subst_to_values will need to do lookups. */ | |
958 | *slot = (void *) e; | |
959 | e->locs = new_elt_loc_list (e->locs, cselib_subst_to_values (x)); | |
960 | return e; | |
961 | } | |
962 | ||
963 | /* Invalidate any entries in reg_values that overlap REGNO. This is called | |
964 | if REGNO is changing. MODE is the mode of the assignment to REGNO, which | |
965 | is used to determine how many hard registers are being changed. If MODE | |
966 | is VOIDmode, then only REGNO is being changed; this is used when | |
967 | invalidating call clobbered registers across a call. */ | |
968 | ||
969 | static void | |
7080f735 | 970 | cselib_invalidate_regno (unsigned int regno, enum machine_mode mode) |
fa49fd0f RK |
971 | { |
972 | unsigned int endregno; | |
973 | unsigned int i; | |
974 | ||
975 | /* If we see pseudos after reload, something is _wrong_. */ | |
341c100f NS |
976 | gcc_assert (!reload_completed || regno < FIRST_PSEUDO_REGISTER |
977 | || reg_renumber[regno] < 0); | |
fa49fd0f RK |
978 | |
979 | /* Determine the range of registers that must be invalidated. For | |
980 | pseudos, only REGNO is affected. For hard regs, we must take MODE | |
981 | into account, and we must also invalidate lower register numbers | |
982 | if they contain values that overlap REGNO. */ | |
291aac59 | 983 | if (regno < FIRST_PSEUDO_REGISTER) |
31825e57 | 984 | { |
341c100f | 985 | gcc_assert (mode != VOIDmode); |
7080f735 | 986 | |
31825e57 DM |
987 | if (regno < max_value_regs) |
988 | i = 0; | |
989 | else | |
990 | i = regno - max_value_regs; | |
fa49fd0f | 991 | |
66fd46b6 | 992 | endregno = regno + hard_regno_nregs[regno][mode]; |
31825e57 DM |
993 | } |
994 | else | |
995 | { | |
996 | i = regno; | |
997 | endregno = regno + 1; | |
998 | } | |
999 | ||
1000 | for (; i < endregno; i++) | |
fa49fd0f RK |
1001 | { |
1002 | struct elt_list **l = ®_VALUES (i); | |
1003 | ||
1004 | /* Go through all known values for this reg; if it overlaps the range | |
1005 | we're invalidating, remove the value. */ | |
1006 | while (*l) | |
1007 | { | |
1008 | cselib_val *v = (*l)->elt; | |
1009 | struct elt_loc_list **p; | |
1010 | unsigned int this_last = i; | |
1011 | ||
60fa6660 | 1012 | if (i < FIRST_PSEUDO_REGISTER && v != NULL) |
66fd46b6 | 1013 | this_last += hard_regno_nregs[i][GET_MODE (v->u.val_rtx)] - 1; |
fa49fd0f | 1014 | |
60fa6660 | 1015 | if (this_last < regno || v == NULL) |
fa49fd0f RK |
1016 | { |
1017 | l = &(*l)->next; | |
1018 | continue; | |
1019 | } | |
1020 | ||
1021 | /* We have an overlap. */ | |
60fa6660 AO |
1022 | if (*l == REG_VALUES (i)) |
1023 | { | |
1024 | /* Maintain the invariant that the first entry of | |
1025 | REG_VALUES, if present, must be the value used to set | |
1026 | the register, or NULL. This is also nice because | |
1027 | then we won't push the same regno onto user_regs | |
1028 | multiple times. */ | |
1029 | (*l)->elt = NULL; | |
1030 | l = &(*l)->next; | |
1031 | } | |
1032 | else | |
1033 | unchain_one_elt_list (l); | |
fa49fd0f RK |
1034 | |
1035 | /* Now, we clear the mapping from value to reg. It must exist, so | |
1036 | this code will crash intentionally if it doesn't. */ | |
1037 | for (p = &v->locs; ; p = &(*p)->next) | |
1038 | { | |
1039 | rtx x = (*p)->loc; | |
1040 | ||
f8cfc6aa | 1041 | if (REG_P (x) && REGNO (x) == i) |
fa49fd0f RK |
1042 | { |
1043 | unchain_one_elt_loc_list (p); | |
1044 | break; | |
1045 | } | |
1046 | } | |
1047 | if (v->locs == 0) | |
1048 | n_useless_values++; | |
1049 | } | |
1050 | } | |
1051 | } | |
9ddb66ca JH |
1052 | \f |
1053 | /* Return 1 if X has a value that can vary even between two | |
1054 | executions of the program. 0 means X can be compared reliably | |
1055 | against certain constants or near-constants. */ | |
fa49fd0f RK |
1056 | |
1057 | static int | |
9ddb66ca | 1058 | cselib_rtx_varies_p (rtx x ATTRIBUTE_UNUSED, int from_alias ATTRIBUTE_UNUSED) |
fa49fd0f | 1059 | { |
9ddb66ca JH |
1060 | /* We actually don't need to verify very hard. This is because |
1061 | if X has actually changed, we invalidate the memory anyway, | |
1062 | so assume that all common memory addresses are | |
1063 | invariant. */ | |
fa49fd0f RK |
1064 | return 0; |
1065 | } | |
1066 | ||
7101fb18 JH |
1067 | /* Invalidate any locations in the table which are changed because of a |
1068 | store to MEM_RTX. If this is called because of a non-const call | |
1069 | instruction, MEM_RTX is (mem:BLK const0_rtx). */ | |
fa49fd0f | 1070 | |
7101fb18 | 1071 | static void |
7080f735 | 1072 | cselib_invalidate_mem (rtx mem_rtx) |
fa49fd0f | 1073 | { |
7101fb18 | 1074 | cselib_val **vp, *v, *next; |
c65ecebc | 1075 | int num_mems = 0; |
9ddb66ca JH |
1076 | rtx mem_addr; |
1077 | ||
1078 | mem_addr = canon_rtx (get_addr (XEXP (mem_rtx, 0))); | |
1079 | mem_rtx = canon_rtx (mem_rtx); | |
fa49fd0f | 1080 | |
7101fb18 JH |
1081 | vp = &first_containing_mem; |
1082 | for (v = *vp; v != &dummy_val; v = next) | |
fa49fd0f | 1083 | { |
7101fb18 JH |
1084 | bool has_mem = false; |
1085 | struct elt_loc_list **p = &v->locs; | |
1086 | int had_locs = v->locs != 0; | |
fa49fd0f | 1087 | |
7101fb18 | 1088 | while (*p) |
fa49fd0f | 1089 | { |
7101fb18 JH |
1090 | rtx x = (*p)->loc; |
1091 | cselib_val *addr; | |
1092 | struct elt_list **mem_chain; | |
1093 | ||
1094 | /* MEMs may occur in locations only at the top level; below | |
1095 | that every MEM or REG is substituted by its VALUE. */ | |
3c0cb5de | 1096 | if (!MEM_P (x)) |
fa49fd0f | 1097 | { |
7101fb18 JH |
1098 | p = &(*p)->next; |
1099 | continue; | |
1100 | } | |
c65ecebc | 1101 | if (num_mems < PARAM_VALUE (PARAM_MAX_CSELIB_MEMORY_LOCATIONS) |
9ddb66ca JH |
1102 | && ! canon_true_dependence (mem_rtx, GET_MODE (mem_rtx), mem_addr, |
1103 | x, cselib_rtx_varies_p)) | |
7101fb18 JH |
1104 | { |
1105 | has_mem = true; | |
c65ecebc | 1106 | num_mems++; |
7101fb18 JH |
1107 | p = &(*p)->next; |
1108 | continue; | |
fa49fd0f RK |
1109 | } |
1110 | ||
7101fb18 JH |
1111 | /* This one overlaps. */ |
1112 | /* We must have a mapping from this MEM's address to the | |
1113 | value (E). Remove that, too. */ | |
1114 | addr = cselib_lookup (XEXP (x, 0), VOIDmode, 0); | |
1115 | mem_chain = &addr->addr_list; | |
1116 | for (;;) | |
1117 | { | |
1118 | if ((*mem_chain)->elt == v) | |
1119 | { | |
1120 | unchain_one_elt_list (mem_chain); | |
1121 | break; | |
1122 | } | |
fa49fd0f | 1123 | |
7101fb18 JH |
1124 | mem_chain = &(*mem_chain)->next; |
1125 | } | |
fa49fd0f | 1126 | |
7101fb18 JH |
1127 | unchain_one_elt_loc_list (p); |
1128 | } | |
fa49fd0f | 1129 | |
7101fb18 JH |
1130 | if (had_locs && v->locs == 0) |
1131 | n_useless_values++; | |
fa49fd0f | 1132 | |
7101fb18 JH |
1133 | next = v->next_containing_mem; |
1134 | if (has_mem) | |
1135 | { | |
1136 | *vp = v; | |
1137 | vp = &(*vp)->next_containing_mem; | |
1138 | } | |
1139 | else | |
1140 | v->next_containing_mem = NULL; | |
1141 | } | |
1142 | *vp = &dummy_val; | |
fa49fd0f RK |
1143 | } |
1144 | ||
0d87c765 | 1145 | /* Invalidate DEST, which is being assigned to or clobbered. */ |
fa49fd0f | 1146 | |
0d87c765 RH |
1147 | void |
1148 | cselib_invalidate_rtx (rtx dest) | |
fa49fd0f | 1149 | { |
46d096a3 SB |
1150 | while (GET_CODE (dest) == SUBREG |
1151 | || GET_CODE (dest) == ZERO_EXTRACT | |
1152 | || GET_CODE (dest) == STRICT_LOW_PART) | |
fa49fd0f RK |
1153 | dest = XEXP (dest, 0); |
1154 | ||
f8cfc6aa | 1155 | if (REG_P (dest)) |
fa49fd0f | 1156 | cselib_invalidate_regno (REGNO (dest), GET_MODE (dest)); |
3c0cb5de | 1157 | else if (MEM_P (dest)) |
fa49fd0f RK |
1158 | cselib_invalidate_mem (dest); |
1159 | ||
1160 | /* Some machines don't define AUTO_INC_DEC, but they still use push | |
1161 | instructions. We need to catch that case here in order to | |
1162 | invalidate the stack pointer correctly. Note that invalidating | |
1163 | the stack pointer is different from invalidating DEST. */ | |
1164 | if (push_operand (dest, GET_MODE (dest))) | |
0d87c765 RH |
1165 | cselib_invalidate_rtx (stack_pointer_rtx); |
1166 | } | |
1167 | ||
1168 | /* A wrapper for cselib_invalidate_rtx to be called via note_stores. */ | |
1169 | ||
1170 | static void | |
1171 | cselib_invalidate_rtx_note_stores (rtx dest, rtx ignore ATTRIBUTE_UNUSED, | |
1172 | void *data ATTRIBUTE_UNUSED) | |
1173 | { | |
1174 | cselib_invalidate_rtx (dest); | |
fa49fd0f RK |
1175 | } |
1176 | ||
1177 | /* Record the result of a SET instruction. DEST is being set; the source | |
1178 | contains the value described by SRC_ELT. If DEST is a MEM, DEST_ADDR_ELT | |
1179 | describes its address. */ | |
1180 | ||
1181 | static void | |
7080f735 | 1182 | cselib_record_set (rtx dest, cselib_val *src_elt, cselib_val *dest_addr_elt) |
fa49fd0f | 1183 | { |
f8cfc6aa | 1184 | int dreg = REG_P (dest) ? (int) REGNO (dest) : -1; |
fa49fd0f RK |
1185 | |
1186 | if (src_elt == 0 || side_effects_p (dest)) | |
1187 | return; | |
1188 | ||
1189 | if (dreg >= 0) | |
1190 | { | |
31825e57 DM |
1191 | if (dreg < FIRST_PSEUDO_REGISTER) |
1192 | { | |
66fd46b6 | 1193 | unsigned int n = hard_regno_nregs[dreg][GET_MODE (dest)]; |
31825e57 DM |
1194 | |
1195 | if (n > max_value_regs) | |
1196 | max_value_regs = n; | |
1197 | } | |
1198 | ||
60fa6660 AO |
1199 | if (REG_VALUES (dreg) == 0) |
1200 | { | |
6790d1ab | 1201 | used_regs[n_used_regs++] = dreg; |
60fa6660 AO |
1202 | REG_VALUES (dreg) = new_elt_list (REG_VALUES (dreg), src_elt); |
1203 | } | |
1204 | else | |
1205 | { | |
341c100f NS |
1206 | /* The register should have been invalidated. */ |
1207 | gcc_assert (REG_VALUES (dreg)->elt == 0); | |
1208 | REG_VALUES (dreg)->elt = src_elt; | |
60fa6660 AO |
1209 | } |
1210 | ||
fa49fd0f RK |
1211 | if (src_elt->locs == 0) |
1212 | n_useless_values--; | |
1213 | src_elt->locs = new_elt_loc_list (src_elt->locs, dest); | |
1214 | } | |
3c0cb5de | 1215 | else if (MEM_P (dest) && dest_addr_elt != 0 |
463301c3 | 1216 | && cselib_record_memory) |
fa49fd0f RK |
1217 | { |
1218 | if (src_elt->locs == 0) | |
1219 | n_useless_values--; | |
1220 | add_mem_for_addr (dest_addr_elt, src_elt, dest); | |
1221 | } | |
1222 | } | |
1223 | ||
1224 | /* Describe a single set that is part of an insn. */ | |
1225 | struct set | |
1226 | { | |
1227 | rtx src; | |
1228 | rtx dest; | |
1229 | cselib_val *src_elt; | |
1230 | cselib_val *dest_addr_elt; | |
1231 | }; | |
1232 | ||
1233 | /* There is no good way to determine how many elements there can be | |
1234 | in a PARALLEL. Since it's fairly cheap, use a really large number. */ | |
1235 | #define MAX_SETS (FIRST_PSEUDO_REGISTER * 2) | |
1236 | ||
1237 | /* Record the effects of any sets in INSN. */ | |
1238 | static void | |
7080f735 | 1239 | cselib_record_sets (rtx insn) |
fa49fd0f RK |
1240 | { |
1241 | int n_sets = 0; | |
1242 | int i; | |
1243 | struct set sets[MAX_SETS]; | |
1244 | rtx body = PATTERN (insn); | |
b7933c21 | 1245 | rtx cond = 0; |
fa49fd0f RK |
1246 | |
1247 | body = PATTERN (insn); | |
b7933c21 BS |
1248 | if (GET_CODE (body) == COND_EXEC) |
1249 | { | |
1250 | cond = COND_EXEC_TEST (body); | |
1251 | body = COND_EXEC_CODE (body); | |
1252 | } | |
1253 | ||
fa49fd0f RK |
1254 | /* Find all sets. */ |
1255 | if (GET_CODE (body) == SET) | |
1256 | { | |
1257 | sets[0].src = SET_SRC (body); | |
1258 | sets[0].dest = SET_DEST (body); | |
1259 | n_sets = 1; | |
1260 | } | |
1261 | else if (GET_CODE (body) == PARALLEL) | |
1262 | { | |
1263 | /* Look through the PARALLEL and record the values being | |
1264 | set, if possible. Also handle any CLOBBERs. */ | |
1265 | for (i = XVECLEN (body, 0) - 1; i >= 0; --i) | |
1266 | { | |
1267 | rtx x = XVECEXP (body, 0, i); | |
1268 | ||
1269 | if (GET_CODE (x) == SET) | |
1270 | { | |
1271 | sets[n_sets].src = SET_SRC (x); | |
1272 | sets[n_sets].dest = SET_DEST (x); | |
1273 | n_sets++; | |
1274 | } | |
1275 | } | |
1276 | } | |
1277 | ||
1278 | /* Look up the values that are read. Do this before invalidating the | |
1279 | locations that are written. */ | |
1280 | for (i = 0; i < n_sets; i++) | |
1281 | { | |
1282 | rtx dest = sets[i].dest; | |
1283 | ||
1284 | /* A STRICT_LOW_PART can be ignored; we'll record the equivalence for | |
1285 | the low part after invalidating any knowledge about larger modes. */ | |
1286 | if (GET_CODE (sets[i].dest) == STRICT_LOW_PART) | |
1287 | sets[i].dest = dest = XEXP (dest, 0); | |
1288 | ||
1289 | /* We don't know how to record anything but REG or MEM. */ | |
f8cfc6aa | 1290 | if (REG_P (dest) |
3c0cb5de | 1291 | || (MEM_P (dest) && cselib_record_memory)) |
fa49fd0f | 1292 | { |
b7933c21 BS |
1293 | rtx src = sets[i].src; |
1294 | if (cond) | |
1295 | src = gen_rtx_IF_THEN_ELSE (GET_MODE (src), cond, src, dest); | |
37060e78 | 1296 | sets[i].src_elt = cselib_lookup (src, GET_MODE (dest), 1); |
3c0cb5de | 1297 | if (MEM_P (dest)) |
fa49fd0f RK |
1298 | sets[i].dest_addr_elt = cselib_lookup (XEXP (dest, 0), Pmode, 1); |
1299 | else | |
1300 | sets[i].dest_addr_elt = 0; | |
1301 | } | |
1302 | } | |
1303 | ||
1304 | /* Invalidate all locations written by this insn. Note that the elts we | |
1305 | looked up in the previous loop aren't affected, just some of their | |
1306 | locations may go away. */ | |
0d87c765 | 1307 | note_stores (body, cselib_invalidate_rtx_note_stores, NULL); |
fa49fd0f | 1308 | |
b7048ab7 RH |
1309 | /* If this is an asm, look for duplicate sets. This can happen when the |
1310 | user uses the same value as an output multiple times. This is valid | |
1311 | if the outputs are not actually used thereafter. Treat this case as | |
1312 | if the value isn't actually set. We do this by smashing the destination | |
1313 | to pc_rtx, so that we won't record the value later. */ | |
1314 | if (n_sets >= 2 && asm_noperands (body) >= 0) | |
1315 | { | |
1316 | for (i = 0; i < n_sets; i++) | |
1317 | { | |
1318 | rtx dest = sets[i].dest; | |
3c0cb5de | 1319 | if (REG_P (dest) || MEM_P (dest)) |
b7048ab7 RH |
1320 | { |
1321 | int j; | |
1322 | for (j = i + 1; j < n_sets; j++) | |
1323 | if (rtx_equal_p (dest, sets[j].dest)) | |
1324 | { | |
1325 | sets[i].dest = pc_rtx; | |
1326 | sets[j].dest = pc_rtx; | |
1327 | } | |
1328 | } | |
1329 | } | |
1330 | } | |
1331 | ||
fa49fd0f RK |
1332 | /* Now enter the equivalences in our tables. */ |
1333 | for (i = 0; i < n_sets; i++) | |
1334 | { | |
1335 | rtx dest = sets[i].dest; | |
f8cfc6aa | 1336 | if (REG_P (dest) |
3c0cb5de | 1337 | || (MEM_P (dest) && cselib_record_memory)) |
fa49fd0f RK |
1338 | cselib_record_set (dest, sets[i].src_elt, sets[i].dest_addr_elt); |
1339 | } | |
1340 | } | |
1341 | ||
1342 | /* Record the effects of INSN. */ | |
1343 | ||
1344 | void | |
7080f735 | 1345 | cselib_process_insn (rtx insn) |
fa49fd0f RK |
1346 | { |
1347 | int i; | |
1348 | rtx x; | |
1349 | ||
9635cfad JH |
1350 | if (find_reg_note (insn, REG_LIBCALL, NULL)) |
1351 | cselib_current_insn_in_libcall = true; | |
fa49fd0f RK |
1352 | cselib_current_insn = insn; |
1353 | ||
1354 | /* Forget everything at a CODE_LABEL, a volatile asm, or a setjmp. */ | |
4b4bf941 JQ |
1355 | if (LABEL_P (insn) |
1356 | || (CALL_P (insn) | |
570a98eb | 1357 | && find_reg_note (insn, REG_SETJMP, NULL)) |
4b4bf941 | 1358 | || (NONJUMP_INSN_P (insn) |
fa49fd0f RK |
1359 | && GET_CODE (PATTERN (insn)) == ASM_OPERANDS |
1360 | && MEM_VOLATILE_P (PATTERN (insn)))) | |
1361 | { | |
5976e643 RS |
1362 | if (find_reg_note (insn, REG_RETVAL, NULL)) |
1363 | cselib_current_insn_in_libcall = false; | |
eb232f4e | 1364 | cselib_clear_table (); |
fa49fd0f RK |
1365 | return; |
1366 | } | |
1367 | ||
1368 | if (! INSN_P (insn)) | |
1369 | { | |
5976e643 RS |
1370 | if (find_reg_note (insn, REG_RETVAL, NULL)) |
1371 | cselib_current_insn_in_libcall = false; | |
fa49fd0f RK |
1372 | cselib_current_insn = 0; |
1373 | return; | |
1374 | } | |
1375 | ||
1376 | /* If this is a call instruction, forget anything stored in a | |
1377 | call clobbered register, or, if this is not a const call, in | |
1378 | memory. */ | |
4b4bf941 | 1379 | if (CALL_P (insn)) |
fa49fd0f RK |
1380 | { |
1381 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
7e42db17 DJ |
1382 | if (call_used_regs[i] |
1383 | || (REG_VALUES (i) && REG_VALUES (i)->elt | |
1384 | && HARD_REGNO_CALL_PART_CLOBBERED (i, | |
1385 | GET_MODE (REG_VALUES (i)->elt->u.val_rtx)))) | |
291aac59 | 1386 | cselib_invalidate_regno (i, reg_raw_mode[i]); |
fa49fd0f | 1387 | |
24a28584 | 1388 | if (! CONST_OR_PURE_CALL_P (insn)) |
fa49fd0f RK |
1389 | cselib_invalidate_mem (callmem); |
1390 | } | |
1391 | ||
1392 | cselib_record_sets (insn); | |
1393 | ||
1394 | #ifdef AUTO_INC_DEC | |
1395 | /* Clobber any registers which appear in REG_INC notes. We | |
1396 | could keep track of the changes to their values, but it is | |
1397 | unlikely to help. */ | |
1398 | for (x = REG_NOTES (insn); x; x = XEXP (x, 1)) | |
1399 | if (REG_NOTE_KIND (x) == REG_INC) | |
0d87c765 | 1400 | cselib_invalidate_rtx (XEXP (x, 0)); |
fa49fd0f RK |
1401 | #endif |
1402 | ||
1403 | /* Look for any CLOBBERs in CALL_INSN_FUNCTION_USAGE, but only | |
1404 | after we have processed the insn. */ | |
4b4bf941 | 1405 | if (CALL_P (insn)) |
fa49fd0f RK |
1406 | for (x = CALL_INSN_FUNCTION_USAGE (insn); x; x = XEXP (x, 1)) |
1407 | if (GET_CODE (XEXP (x, 0)) == CLOBBER) | |
0d87c765 | 1408 | cselib_invalidate_rtx (XEXP (XEXP (x, 0), 0)); |
fa49fd0f | 1409 | |
5976e643 RS |
1410 | if (find_reg_note (insn, REG_RETVAL, NULL)) |
1411 | cselib_current_insn_in_libcall = false; | |
fa49fd0f RK |
1412 | cselib_current_insn = 0; |
1413 | ||
1414 | if (n_useless_values > MAX_USELESS_VALUES) | |
1415 | remove_useless_values (); | |
1416 | } | |
1417 | ||
fa49fd0f RK |
1418 | /* Initialize cselib for one pass. The caller must also call |
1419 | init_alias_analysis. */ | |
1420 | ||
1421 | void | |
463301c3 | 1422 | cselib_init (bool record_memory) |
fa49fd0f | 1423 | { |
6a59927d JH |
1424 | elt_list_pool = create_alloc_pool ("elt_list", |
1425 | sizeof (struct elt_list), 10); | |
1426 | elt_loc_list_pool = create_alloc_pool ("elt_loc_list", | |
1427 | sizeof (struct elt_loc_list), 10); | |
1428 | cselib_val_pool = create_alloc_pool ("cselib_val_list", | |
1429 | sizeof (cselib_val), 10); | |
23bd7a93 JH |
1430 | value_pool = create_alloc_pool ("value", |
1431 | RTX_SIZE (VALUE), 100); | |
463301c3 | 1432 | cselib_record_memory = record_memory; |
e2500fed | 1433 | /* This is only created once. */ |
fa49fd0f | 1434 | if (! callmem) |
e2500fed | 1435 | callmem = gen_rtx_MEM (BLKmode, const0_rtx); |
fa49fd0f RK |
1436 | |
1437 | cselib_nregs = max_reg_num (); | |
6790d1ab JH |
1438 | |
1439 | /* We preserve reg_values to allow expensive clearing of the whole thing. | |
1440 | Reallocate it however if it happens to be too large. */ | |
1441 | if (!reg_values || reg_values_size < cselib_nregs | |
1442 | || (reg_values_size > 10 && reg_values_size > cselib_nregs * 4)) | |
e2500fed | 1443 | { |
6790d1ab JH |
1444 | if (reg_values) |
1445 | free (reg_values); | |
1446 | /* Some space for newly emit instructions so we don't end up | |
1447 | reallocating in between passes. */ | |
1448 | reg_values_size = cselib_nregs + (63 + cselib_nregs) / 16; | |
1449 | reg_values = xcalloc (reg_values_size, sizeof (reg_values)); | |
e2500fed | 1450 | } |
6790d1ab JH |
1451 | used_regs = xmalloc (sizeof (*used_regs) * cselib_nregs); |
1452 | n_used_regs = 0; | |
1453 | hash_table = htab_create (31, get_value_hash, entry_and_rtx_equal_p, NULL); | |
9635cfad | 1454 | cselib_current_insn_in_libcall = false; |
fa49fd0f RK |
1455 | } |
1456 | ||
1457 | /* Called when the current user is done with cselib. */ | |
1458 | ||
1459 | void | |
7080f735 | 1460 | cselib_finish (void) |
fa49fd0f | 1461 | { |
6a59927d JH |
1462 | free_alloc_pool (elt_list_pool); |
1463 | free_alloc_pool (elt_loc_list_pool); | |
1464 | free_alloc_pool (cselib_val_pool); | |
23bd7a93 | 1465 | free_alloc_pool (value_pool); |
eb232f4e | 1466 | cselib_clear_table (); |
6790d1ab | 1467 | htab_delete (hash_table); |
0fc0c4c9 | 1468 | free (used_regs); |
e2500fed GK |
1469 | used_regs = 0; |
1470 | hash_table = 0; | |
1471 | n_useless_values = 0; | |
1472 | next_unknown_value = 0; | |
fa49fd0f | 1473 | } |
e2500fed GK |
1474 | |
1475 | #include "gt-cselib.h" |