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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, | |
d9221e01 | 3 | 1999, 2000, 2001, 2003, 2004 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 LB |
18 | along with GCC; see the file COPYING. If not, write to the Free |
19 | Software Foundation, 59 Temple Place - Suite 330, Boston, MA | |
20 | 02111-1307, USA. */ | |
fa49fd0f RK |
21 | |
22 | #include "config.h" | |
23 | #include "system.h" | |
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" | |
36 | #include "expr.h" | |
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 | |
7080f735 AJ |
45 | static int entry_and_rtx_equal_p (const void *, const void *); |
46 | static hashval_t get_value_hash (const void *); | |
47 | static struct elt_list *new_elt_list (struct elt_list *, cselib_val *); | |
48 | static struct elt_loc_list *new_elt_loc_list (struct elt_loc_list *, rtx); | |
49 | static void unchain_one_value (cselib_val *); | |
50 | static void unchain_one_elt_list (struct elt_list **); | |
51 | static void unchain_one_elt_loc_list (struct elt_loc_list **); | |
52 | static void clear_table (void); | |
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); | |
57 | static unsigned int hash_rtx (rtx, enum machine_mode, int); | |
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 AJ |
62 | static void cselib_invalidate_mem (rtx); |
63 | static void cselib_invalidate_rtx (rtx, rtx, void *); | |
64 | static void cselib_record_set (rtx, cselib_val *, cselib_val *); | |
65 | static void cselib_record_sets (rtx); | |
fa49fd0f RK |
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. */ | |
e2500fed | 77 | static GTY((param_is (cselib_val))) htab_t hash_table; |
fa49fd0f RK |
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; | |
9635cfad | 82 | static bool cselib_current_insn_in_libcall; |
fa49fd0f RK |
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 | ||
60fa6660 AO |
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. */ | |
e2500fed GK |
104 | static GTY(()) varray_type reg_values; |
105 | static GTY((deletable (""))) varray_type reg_values_old; | |
fa49fd0f RK |
106 | #define REG_VALUES(I) VARRAY_ELT_LIST (reg_values, (I)) |
107 | ||
31825e57 | 108 | /* The largest number of hard regs used by any entry added to the |
e34bb004 | 109 | REG_VALUES table. Cleared on each clear_table() invocation. */ |
31825e57 DM |
110 | static unsigned int max_value_regs; |
111 | ||
fa49fd0f RK |
112 | /* Here the set of indices I with REG_VALUES(I) != 0 is saved. This is used |
113 | in clear_table() for fast emptying. */ | |
e2500fed GK |
114 | static GTY(()) varray_type used_regs; |
115 | static GTY((deletable (""))) varray_type used_regs_old; | |
fa49fd0f RK |
116 | |
117 | /* We pass this to cselib_invalidate_mem to invalidate all of | |
118 | memory for a non-const call instruction. */ | |
e2500fed | 119 | static GTY(()) rtx callmem; |
fa49fd0f | 120 | |
fa49fd0f RK |
121 | /* Set by discard_useless_locs if it deleted the last location of any |
122 | value. */ | |
123 | static int values_became_useless; | |
7101fb18 JH |
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 | ||
7080f735 | 129 | /* Used to list all values that contain memory reference. |
7101fb18 JH |
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; | |
23bd7a93 | 133 | static alloc_pool elt_loc_list_pool, elt_list_pool, cselib_val_pool, value_pool; |
fa49fd0f RK |
134 | \f |
135 | ||
136 | /* Allocate a struct elt_list and fill in its two elements with the | |
137 | arguments. */ | |
138 | ||
6a59927d | 139 | static inline struct elt_list * |
7080f735 | 140 | new_elt_list (struct elt_list *next, cselib_val *elt) |
fa49fd0f | 141 | { |
6a59927d JH |
142 | struct elt_list *el; |
143 | el = pool_alloc (elt_list_pool); | |
fa49fd0f RK |
144 | el->next = next; |
145 | el->elt = elt; | |
146 | return el; | |
147 | } | |
148 | ||
149 | /* Allocate a struct elt_loc_list and fill in its two elements with the | |
150 | arguments. */ | |
151 | ||
6a59927d | 152 | static inline struct elt_loc_list * |
7080f735 | 153 | new_elt_loc_list (struct elt_loc_list *next, rtx loc) |
fa49fd0f | 154 | { |
6a59927d JH |
155 | struct elt_loc_list *el; |
156 | el = pool_alloc (elt_loc_list_pool); | |
fa49fd0f RK |
157 | el->next = next; |
158 | el->loc = loc; | |
9ddb66ca | 159 | el->canon_loc = NULL; |
fa49fd0f | 160 | el->setting_insn = cselib_current_insn; |
9635cfad | 161 | el->in_libcall = cselib_current_insn_in_libcall; |
fa49fd0f RK |
162 | return el; |
163 | } | |
164 | ||
165 | /* The elt_list at *PL is no longer needed. Unchain it and free its | |
166 | storage. */ | |
167 | ||
6a59927d | 168 | static inline void |
7080f735 | 169 | unchain_one_elt_list (struct elt_list **pl) |
fa49fd0f RK |
170 | { |
171 | struct elt_list *l = *pl; | |
172 | ||
173 | *pl = l->next; | |
6a59927d | 174 | pool_free (elt_list_pool, l); |
fa49fd0f RK |
175 | } |
176 | ||
177 | /* Likewise for elt_loc_lists. */ | |
178 | ||
179 | static void | |
7080f735 | 180 | unchain_one_elt_loc_list (struct elt_loc_list **pl) |
fa49fd0f RK |
181 | { |
182 | struct elt_loc_list *l = *pl; | |
183 | ||
184 | *pl = l->next; | |
6a59927d | 185 | pool_free (elt_loc_list_pool, l); |
fa49fd0f RK |
186 | } |
187 | ||
188 | /* Likewise for cselib_vals. This also frees the addr_list associated with | |
189 | V. */ | |
190 | ||
191 | static void | |
7080f735 | 192 | unchain_one_value (cselib_val *v) |
fa49fd0f RK |
193 | { |
194 | while (v->addr_list) | |
195 | unchain_one_elt_list (&v->addr_list); | |
196 | ||
6a59927d | 197 | pool_free (cselib_val_pool, v); |
fa49fd0f RK |
198 | } |
199 | ||
200 | /* Remove all entries from the hash table. Also used during | |
201 | initialization. If CLEAR_ALL isn't set, then only clear the entries | |
202 | which are known to have been used. */ | |
203 | ||
204 | static void | |
7080f735 | 205 | clear_table (void) |
fa49fd0f RK |
206 | { |
207 | unsigned int i; | |
208 | ||
cd648cec JH |
209 | for (i = 0; i < VARRAY_ACTIVE_SIZE (used_regs); i++) |
210 | REG_VALUES (VARRAY_UINT (used_regs, i)) = 0; | |
fa49fd0f | 211 | |
31825e57 DM |
212 | max_value_regs = 0; |
213 | ||
fa49fd0f RK |
214 | VARRAY_POP_ALL (used_regs); |
215 | ||
216 | htab_empty (hash_table); | |
fa49fd0f | 217 | |
fa49fd0f RK |
218 | n_useless_values = 0; |
219 | ||
220 | next_unknown_value = 0; | |
7101fb18 JH |
221 | |
222 | first_containing_mem = &dummy_val; | |
fa49fd0f RK |
223 | } |
224 | ||
225 | /* The equality test for our hash table. The first argument ENTRY is a table | |
226 | element (i.e. a cselib_val), while the second arg X is an rtx. We know | |
227 | that all callers of htab_find_slot_with_hash will wrap CONST_INTs into a | |
228 | CONST of an appropriate mode. */ | |
229 | ||
230 | static int | |
7080f735 | 231 | entry_and_rtx_equal_p (const void *entry, const void *x_arg) |
fa49fd0f RK |
232 | { |
233 | struct elt_loc_list *l; | |
234 | const cselib_val *v = (const cselib_val *) entry; | |
235 | rtx x = (rtx) x_arg; | |
236 | enum machine_mode mode = GET_MODE (x); | |
237 | ||
238 | if (GET_CODE (x) == CONST_INT | |
239 | || (mode == VOIDmode && GET_CODE (x) == CONST_DOUBLE)) | |
240 | abort (); | |
241 | if (mode != GET_MODE (v->u.val_rtx)) | |
242 | return 0; | |
243 | ||
244 | /* Unwrap X if necessary. */ | |
245 | if (GET_CODE (x) == CONST | |
246 | && (GET_CODE (XEXP (x, 0)) == CONST_INT | |
247 | || GET_CODE (XEXP (x, 0)) == CONST_DOUBLE)) | |
248 | x = XEXP (x, 0); | |
7080f735 | 249 | |
fa49fd0f RK |
250 | /* We don't guarantee that distinct rtx's have different hash values, |
251 | so we need to do a comparison. */ | |
252 | for (l = v->locs; l; l = l->next) | |
253 | if (rtx_equal_for_cselib_p (l->loc, x)) | |
254 | return 1; | |
255 | ||
256 | return 0; | |
257 | } | |
258 | ||
259 | /* The hash function for our hash table. The value is always computed with | |
260 | hash_rtx when adding an element; this function just extracts the hash | |
261 | value from a cselib_val structure. */ | |
262 | ||
fb7e6024 | 263 | static hashval_t |
7080f735 | 264 | get_value_hash (const void *entry) |
fa49fd0f RK |
265 | { |
266 | const cselib_val *v = (const cselib_val *) entry; | |
267 | return v->value; | |
268 | } | |
269 | ||
270 | /* Return true if X contains a VALUE rtx. If ONLY_USELESS is set, we | |
271 | only return true for values which point to a cselib_val whose value | |
272 | element has been set to zero, which implies the cselib_val will be | |
273 | removed. */ | |
274 | ||
275 | int | |
7080f735 | 276 | references_value_p (rtx x, int only_useless) |
fa49fd0f RK |
277 | { |
278 | enum rtx_code code = GET_CODE (x); | |
279 | const char *fmt = GET_RTX_FORMAT (code); | |
280 | int i, j; | |
281 | ||
282 | if (GET_CODE (x) == VALUE | |
283 | && (! only_useless || CSELIB_VAL_PTR (x)->locs == 0)) | |
284 | return 1; | |
285 | ||
286 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
287 | { | |
288 | if (fmt[i] == 'e' && references_value_p (XEXP (x, i), only_useless)) | |
289 | return 1; | |
290 | else if (fmt[i] == 'E') | |
291 | for (j = 0; j < XVECLEN (x, i); j++) | |
292 | if (references_value_p (XVECEXP (x, i, j), only_useless)) | |
293 | return 1; | |
294 | } | |
295 | ||
296 | return 0; | |
297 | } | |
298 | ||
299 | /* For all locations found in X, delete locations that reference useless | |
300 | values (i.e. values without any location). Called through | |
301 | htab_traverse. */ | |
302 | ||
303 | static int | |
7080f735 | 304 | discard_useless_locs (void **x, void *info ATTRIBUTE_UNUSED) |
fa49fd0f RK |
305 | { |
306 | cselib_val *v = (cselib_val *)*x; | |
307 | struct elt_loc_list **p = &v->locs; | |
308 | int had_locs = v->locs != 0; | |
309 | ||
310 | while (*p) | |
311 | { | |
312 | if (references_value_p ((*p)->loc, 1)) | |
313 | unchain_one_elt_loc_list (p); | |
314 | else | |
315 | p = &(*p)->next; | |
316 | } | |
317 | ||
318 | if (had_locs && v->locs == 0) | |
319 | { | |
320 | n_useless_values++; | |
321 | values_became_useless = 1; | |
322 | } | |
323 | return 1; | |
324 | } | |
325 | ||
326 | /* If X is a value with no locations, remove it from the hashtable. */ | |
327 | ||
328 | static int | |
7080f735 | 329 | discard_useless_values (void **x, void *info ATTRIBUTE_UNUSED) |
fa49fd0f RK |
330 | { |
331 | cselib_val *v = (cselib_val *)*x; | |
332 | ||
333 | if (v->locs == 0) | |
334 | { | |
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 | |
7080f735 | 347 | remove_useless_values (void) |
fa49fd0f | 348 | { |
7101fb18 | 349 | cselib_val **p, *v; |
fa49fd0f RK |
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. */ | |
360 | htab_traverse (hash_table, discard_useless_values, 0); | |
361 | ||
7101fb18 JH |
362 | p = &first_containing_mem; |
363 | for (v = *p; v != &dummy_val; v = v->next_containing_mem) | |
364 | if (v->locs) | |
365 | { | |
366 | *p = v; | |
367 | p = &(*p)->next_containing_mem; | |
368 | } | |
369 | *p = &dummy_val; | |
370 | ||
fa49fd0f RK |
371 | if (n_useless_values != 0) |
372 | abort (); | |
373 | } | |
374 | ||
60fa6660 AO |
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 | |
7080f735 | 381 | cselib_reg_set_mode (rtx x) |
60fa6660 AO |
382 | { |
383 | if (GET_CODE (x) != REG) | |
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 | ||
fa49fd0f RK |
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 | |
7080f735 | 397 | rtx_equal_for_cselib_p (rtx x, rtx y) |
fa49fd0f RK |
398 | { |
399 | enum rtx_code code; | |
400 | const char *fmt; | |
401 | int i; | |
7080f735 | 402 | |
fa49fd0f RK |
403 | if (GET_CODE (x) == REG || GET_CODE (x) == MEM) |
404 | { | |
405 | cselib_val *e = cselib_lookup (x, GET_MODE (x), 0); | |
406 | ||
407 | if (e) | |
408 | x = e->u.val_rtx; | |
409 | } | |
410 | ||
411 | if (GET_CODE (y) == REG || GET_CODE (y) == MEM) | |
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. */ | |
435 | if (GET_CODE (t) == REG || GET_CODE (t) == MEM) | |
436 | continue; | |
437 | else if (rtx_equal_for_cselib_p (t, y)) | |
438 | return 1; | |
439 | } | |
7080f735 | 440 | |
fa49fd0f RK |
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 | ||
453 | if (GET_CODE (t) == REG || GET_CODE (t) == MEM) | |
454 | continue; | |
455 | else if (rtx_equal_for_cselib_p (x, t)) | |
456 | return 1; | |
457 | } | |
7080f735 | 458 | |
fa49fd0f RK |
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); | |
7080f735 | 468 | |
fa49fd0f RK |
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: | |
525 | abort (); | |
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 | |
7080f735 | 535 | wrap_constant (enum machine_mode mode, rtx x) |
fa49fd0f RK |
536 | { |
537 | if (GET_CODE (x) != CONST_INT | |
538 | && (GET_CODE (x) != CONST_DOUBLE || GET_MODE (x) != VOIDmode)) | |
539 | return x; | |
540 | if (mode == VOIDmode) | |
541 | abort (); | |
542 | return gen_rtx_CONST (mode, x); | |
543 | } | |
544 | ||
545 | /* Hash an rtx. Return 0 if we couldn't hash the rtx. | |
546 | For registers and memory locations, we look up their cselib_val structure | |
547 | and return its VALUE element. | |
548 | Possible reasons for return 0 are: the object is volatile, or we couldn't | |
549 | find a register or memory location in the table and CREATE is zero. If | |
550 | CREATE is nonzero, table elts are created for regs and mem. | |
551 | MODE is used in hashing for CONST_INTs only; | |
552 | otherwise the mode of X is used. */ | |
553 | ||
554 | static unsigned int | |
7080f735 | 555 | hash_rtx (rtx x, enum machine_mode mode, int create) |
fa49fd0f RK |
556 | { |
557 | cselib_val *e; | |
558 | int i, j; | |
559 | enum rtx_code code; | |
560 | const char *fmt; | |
561 | unsigned int hash = 0; | |
562 | ||
fa49fd0f RK |
563 | code = GET_CODE (x); |
564 | hash += (unsigned) code + (unsigned) GET_MODE (x); | |
565 | ||
566 | switch (code) | |
567 | { | |
568 | case MEM: | |
569 | case REG: | |
570 | e = cselib_lookup (x, GET_MODE (x), create); | |
571 | if (! e) | |
572 | return 0; | |
573 | ||
a4f4333a | 574 | return e->value; |
fa49fd0f RK |
575 | |
576 | case CONST_INT: | |
577 | hash += ((unsigned) CONST_INT << 7) + (unsigned) mode + INTVAL (x); | |
dc76f41c | 578 | return hash ? hash : (unsigned int) CONST_INT; |
fa49fd0f RK |
579 | |
580 | case CONST_DOUBLE: | |
581 | /* This is like the general case, except that it only counts | |
582 | the integers representing the constant. */ | |
583 | hash += (unsigned) code + (unsigned) GET_MODE (x); | |
584 | if (GET_MODE (x) != VOIDmode) | |
46b33600 | 585 | hash += real_hash (CONST_DOUBLE_REAL_VALUE (x)); |
fa49fd0f RK |
586 | else |
587 | hash += ((unsigned) CONST_DOUBLE_LOW (x) | |
588 | + (unsigned) CONST_DOUBLE_HIGH (x)); | |
dc76f41c | 589 | return hash ? hash : (unsigned int) CONST_DOUBLE; |
fa49fd0f | 590 | |
69ef87e2 AH |
591 | case CONST_VECTOR: |
592 | { | |
593 | int units; | |
594 | rtx elt; | |
595 | ||
596 | units = CONST_VECTOR_NUNITS (x); | |
597 | ||
598 | for (i = 0; i < units; ++i) | |
599 | { | |
600 | elt = CONST_VECTOR_ELT (x, i); | |
601 | hash += hash_rtx (elt, GET_MODE (elt), 0); | |
602 | } | |
603 | ||
604 | return hash; | |
605 | } | |
606 | ||
fa49fd0f RK |
607 | /* Assume there is only one rtx object for any given label. */ |
608 | case LABEL_REF: | |
609 | hash | |
610 | += ((unsigned) LABEL_REF << 7) + (unsigned long) XEXP (x, 0); | |
dc76f41c | 611 | return hash ? hash : (unsigned int) LABEL_REF; |
fa49fd0f RK |
612 | |
613 | case SYMBOL_REF: | |
614 | hash | |
615 | += ((unsigned) SYMBOL_REF << 7) + (unsigned long) XSTR (x, 0); | |
dc76f41c | 616 | return hash ? hash : (unsigned int) SYMBOL_REF; |
fa49fd0f RK |
617 | |
618 | case PRE_DEC: | |
619 | case PRE_INC: | |
620 | case POST_DEC: | |
621 | case POST_INC: | |
622 | case POST_MODIFY: | |
623 | case PRE_MODIFY: | |
624 | case PC: | |
625 | case CC0: | |
626 | case CALL: | |
627 | case UNSPEC_VOLATILE: | |
628 | return 0; | |
629 | ||
630 | case ASM_OPERANDS: | |
631 | if (MEM_VOLATILE_P (x)) | |
632 | return 0; | |
633 | ||
634 | break; | |
7080f735 | 635 | |
fa49fd0f RK |
636 | default: |
637 | break; | |
638 | } | |
639 | ||
640 | i = GET_RTX_LENGTH (code) - 1; | |
641 | fmt = GET_RTX_FORMAT (code); | |
642 | for (; i >= 0; i--) | |
643 | { | |
644 | if (fmt[i] == 'e') | |
645 | { | |
646 | rtx tem = XEXP (x, i); | |
669ff14e BS |
647 | unsigned int tem_hash = hash_rtx (tem, 0, create); |
648 | ||
fa49fd0f RK |
649 | if (tem_hash == 0) |
650 | return 0; | |
651 | ||
652 | hash += tem_hash; | |
653 | } | |
654 | else if (fmt[i] == 'E') | |
655 | for (j = 0; j < XVECLEN (x, i); j++) | |
656 | { | |
657 | unsigned int tem_hash = hash_rtx (XVECEXP (x, i, j), 0, create); | |
658 | ||
659 | if (tem_hash == 0) | |
660 | return 0; | |
661 | ||
662 | hash += tem_hash; | |
663 | } | |
664 | else if (fmt[i] == 's') | |
665 | { | |
666 | const unsigned char *p = (const unsigned char *) XSTR (x, i); | |
667 | ||
668 | if (p) | |
669 | while (*p) | |
670 | hash += *p++; | |
671 | } | |
672 | else if (fmt[i] == 'i') | |
673 | hash += XINT (x, i); | |
674 | else if (fmt[i] == '0' || fmt[i] == 't') | |
675 | /* unused */; | |
676 | else | |
677 | abort (); | |
678 | } | |
679 | ||
dc76f41c | 680 | return hash ? hash : 1 + (unsigned int) GET_CODE (x); |
fa49fd0f RK |
681 | } |
682 | ||
683 | /* Create a new value structure for VALUE and initialize it. The mode of the | |
684 | value is MODE. */ | |
685 | ||
6a59927d | 686 | static inline cselib_val * |
7080f735 | 687 | new_cselib_val (unsigned int value, enum machine_mode mode) |
fa49fd0f | 688 | { |
6a59927d | 689 | cselib_val *e = pool_alloc (cselib_val_pool); |
fa49fd0f | 690 | |
6a59927d | 691 | #ifdef ENABLE_CHECKING |
fa49fd0f RK |
692 | if (value == 0) |
693 | abort (); | |
6a59927d | 694 | #endif |
fa49fd0f RK |
695 | |
696 | e->value = value; | |
23bd7a93 JH |
697 | /* We use custom method to allocate this RTL construct because it accounts |
698 | about 8% of overall memory usage. */ | |
699 | e->u.val_rtx = pool_alloc (value_pool); | |
700 | memset (e->u.val_rtx, 0, RTX_HDR_SIZE); | |
701 | PUT_CODE (e->u.val_rtx, VALUE); | |
702 | PUT_MODE (e->u.val_rtx, mode); | |
fa49fd0f RK |
703 | CSELIB_VAL_PTR (e->u.val_rtx) = e; |
704 | e->addr_list = 0; | |
705 | e->locs = 0; | |
7101fb18 | 706 | e->next_containing_mem = 0; |
fa49fd0f RK |
707 | return e; |
708 | } | |
709 | ||
710 | /* ADDR_ELT is a value that is used as address. MEM_ELT is the value that | |
711 | contains the data at this address. X is a MEM that represents the | |
712 | value. Update the two value structures to represent this situation. */ | |
713 | ||
714 | static void | |
7080f735 | 715 | add_mem_for_addr (cselib_val *addr_elt, cselib_val *mem_elt, rtx x) |
fa49fd0f | 716 | { |
fa49fd0f RK |
717 | struct elt_loc_list *l; |
718 | ||
719 | /* Avoid duplicates. */ | |
720 | for (l = mem_elt->locs; l; l = l->next) | |
721 | if (GET_CODE (l->loc) == MEM | |
722 | && CSELIB_VAL_PTR (XEXP (l->loc, 0)) == addr_elt) | |
723 | return; | |
724 | ||
fa49fd0f | 725 | addr_elt->addr_list = new_elt_list (addr_elt->addr_list, mem_elt); |
f1ec5147 RK |
726 | mem_elt->locs |
727 | = new_elt_loc_list (mem_elt->locs, | |
728 | replace_equiv_address_nv (x, addr_elt->u.val_rtx)); | |
7101fb18 JH |
729 | if (mem_elt->next_containing_mem == NULL) |
730 | { | |
731 | mem_elt->next_containing_mem = first_containing_mem; | |
732 | first_containing_mem = mem_elt; | |
733 | } | |
fa49fd0f RK |
734 | } |
735 | ||
736 | /* Subroutine of cselib_lookup. Return a value for X, which is a MEM rtx. | |
737 | If CREATE, make a new one if we haven't seen it before. */ | |
738 | ||
739 | static cselib_val * | |
7080f735 | 740 | cselib_lookup_mem (rtx x, int create) |
fa49fd0f RK |
741 | { |
742 | enum machine_mode mode = GET_MODE (x); | |
743 | void **slot; | |
744 | cselib_val *addr; | |
745 | cselib_val *mem_elt; | |
746 | struct elt_list *l; | |
747 | ||
748 | if (MEM_VOLATILE_P (x) || mode == BLKmode | |
749 | || (FLOAT_MODE_P (mode) && flag_float_store)) | |
750 | return 0; | |
751 | ||
752 | /* Look up the value for the address. */ | |
753 | addr = cselib_lookup (XEXP (x, 0), mode, create); | |
754 | if (! addr) | |
755 | return 0; | |
756 | ||
757 | /* Find a value that describes a value of our mode at that address. */ | |
758 | for (l = addr->addr_list; l; l = l->next) | |
759 | if (GET_MODE (l->elt->u.val_rtx) == mode) | |
760 | return l->elt; | |
761 | ||
762 | if (! create) | |
763 | return 0; | |
764 | ||
765 | mem_elt = new_cselib_val (++next_unknown_value, mode); | |
766 | add_mem_for_addr (addr, mem_elt, x); | |
767 | slot = htab_find_slot_with_hash (hash_table, wrap_constant (mode, x), | |
768 | mem_elt->value, INSERT); | |
769 | *slot = mem_elt; | |
770 | return mem_elt; | |
771 | } | |
772 | ||
773 | /* Walk rtx X and replace all occurrences of REG and MEM subexpressions | |
774 | with VALUE expressions. This way, it becomes independent of changes | |
775 | to registers and memory. | |
776 | X isn't actually modified; if modifications are needed, new rtl is | |
777 | allocated. However, the return value can share rtl with X. */ | |
778 | ||
91700444 | 779 | rtx |
7080f735 | 780 | cselib_subst_to_values (rtx x) |
fa49fd0f RK |
781 | { |
782 | enum rtx_code code = GET_CODE (x); | |
783 | const char *fmt = GET_RTX_FORMAT (code); | |
784 | cselib_val *e; | |
785 | struct elt_list *l; | |
786 | rtx copy = x; | |
787 | int i; | |
788 | ||
789 | switch (code) | |
790 | { | |
791 | case REG: | |
60fa6660 AO |
792 | l = REG_VALUES (REGNO (x)); |
793 | if (l && l->elt == NULL) | |
794 | l = l->next; | |
795 | for (; l; l = l->next) | |
fa49fd0f RK |
796 | if (GET_MODE (l->elt->u.val_rtx) == GET_MODE (x)) |
797 | return l->elt->u.val_rtx; | |
798 | ||
799 | abort (); | |
800 | ||
801 | case MEM: | |
802 | e = cselib_lookup_mem (x, 0); | |
803 | if (! e) | |
91700444 BS |
804 | { |
805 | /* This happens for autoincrements. Assign a value that doesn't | |
806 | match any other. */ | |
807 | e = new_cselib_val (++next_unknown_value, GET_MODE (x)); | |
808 | } | |
fa49fd0f RK |
809 | return e->u.val_rtx; |
810 | ||
fa49fd0f | 811 | case CONST_DOUBLE: |
69ef87e2 | 812 | case CONST_VECTOR: |
fa49fd0f RK |
813 | case CONST_INT: |
814 | return x; | |
815 | ||
91700444 BS |
816 | case POST_INC: |
817 | case PRE_INC: | |
818 | case POST_DEC: | |
819 | case PRE_DEC: | |
820 | case POST_MODIFY: | |
821 | case PRE_MODIFY: | |
822 | e = new_cselib_val (++next_unknown_value, GET_MODE (x)); | |
823 | return e->u.val_rtx; | |
7080f735 | 824 | |
fa49fd0f RK |
825 | default: |
826 | break; | |
827 | } | |
828 | ||
829 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
830 | { | |
831 | if (fmt[i] == 'e') | |
832 | { | |
833 | rtx t = cselib_subst_to_values (XEXP (x, i)); | |
834 | ||
835 | if (t != XEXP (x, i) && x == copy) | |
836 | copy = shallow_copy_rtx (x); | |
837 | ||
838 | XEXP (copy, i) = t; | |
839 | } | |
840 | else if (fmt[i] == 'E') | |
841 | { | |
842 | int j, k; | |
843 | ||
844 | for (j = 0; j < XVECLEN (x, i); j++) | |
845 | { | |
846 | rtx t = cselib_subst_to_values (XVECEXP (x, i, j)); | |
847 | ||
848 | if (t != XVECEXP (x, i, j) && XVEC (x, i) == XVEC (copy, i)) | |
849 | { | |
850 | if (x == copy) | |
851 | copy = shallow_copy_rtx (x); | |
852 | ||
853 | XVEC (copy, i) = rtvec_alloc (XVECLEN (x, i)); | |
854 | for (k = 0; k < j; k++) | |
855 | XVECEXP (copy, i, k) = XVECEXP (x, i, k); | |
856 | } | |
857 | ||
858 | XVECEXP (copy, i, j) = t; | |
859 | } | |
860 | } | |
861 | } | |
862 | ||
863 | return copy; | |
864 | } | |
865 | ||
866 | /* Look up the rtl expression X in our tables and return the value it has. | |
867 | If CREATE is zero, we return NULL if we don't know the value. Otherwise, | |
868 | we create a new one if possible, using mode MODE if X doesn't have a mode | |
869 | (i.e. because it's a constant). */ | |
870 | ||
871 | cselib_val * | |
7080f735 | 872 | cselib_lookup (rtx x, enum machine_mode mode, int create) |
fa49fd0f RK |
873 | { |
874 | void **slot; | |
875 | cselib_val *e; | |
876 | unsigned int hashval; | |
877 | ||
878 | if (GET_MODE (x) != VOIDmode) | |
879 | mode = GET_MODE (x); | |
880 | ||
881 | if (GET_CODE (x) == VALUE) | |
882 | return CSELIB_VAL_PTR (x); | |
883 | ||
884 | if (GET_CODE (x) == REG) | |
885 | { | |
886 | struct elt_list *l; | |
887 | unsigned int i = REGNO (x); | |
888 | ||
60fa6660 AO |
889 | l = REG_VALUES (i); |
890 | if (l && l->elt == NULL) | |
891 | l = l->next; | |
892 | for (; l; l = l->next) | |
fa49fd0f RK |
893 | if (mode == GET_MODE (l->elt->u.val_rtx)) |
894 | return l->elt; | |
895 | ||
896 | if (! create) | |
897 | return 0; | |
898 | ||
31825e57 DM |
899 | if (i < FIRST_PSEUDO_REGISTER) |
900 | { | |
901 | unsigned int n = HARD_REGNO_NREGS (i, mode); | |
902 | ||
903 | if (n > max_value_regs) | |
904 | max_value_regs = n; | |
905 | } | |
906 | ||
fa49fd0f RK |
907 | e = new_cselib_val (++next_unknown_value, GET_MODE (x)); |
908 | e->locs = new_elt_loc_list (e->locs, x); | |
909 | if (REG_VALUES (i) == 0) | |
60fa6660 AO |
910 | { |
911 | /* Maintain the invariant that the first entry of | |
912 | REG_VALUES, if present, must be the value used to set the | |
913 | register, or NULL. */ | |
914 | VARRAY_PUSH_UINT (used_regs, i); | |
915 | REG_VALUES (i) = new_elt_list (REG_VALUES (i), NULL); | |
916 | } | |
917 | REG_VALUES (i)->next = new_elt_list (REG_VALUES (i)->next, e); | |
fa49fd0f RK |
918 | slot = htab_find_slot_with_hash (hash_table, x, e->value, INSERT); |
919 | *slot = e; | |
920 | return e; | |
921 | } | |
922 | ||
923 | if (GET_CODE (x) == MEM) | |
924 | return cselib_lookup_mem (x, create); | |
925 | ||
926 | hashval = hash_rtx (x, mode, create); | |
927 | /* Can't even create if hashing is not possible. */ | |
928 | if (! hashval) | |
929 | return 0; | |
930 | ||
931 | slot = htab_find_slot_with_hash (hash_table, wrap_constant (mode, x), | |
932 | hashval, create ? INSERT : NO_INSERT); | |
933 | if (slot == 0) | |
934 | return 0; | |
935 | ||
936 | e = (cselib_val *) *slot; | |
937 | if (e) | |
938 | return e; | |
939 | ||
940 | e = new_cselib_val (hashval, mode); | |
941 | ||
942 | /* We have to fill the slot before calling cselib_subst_to_values: | |
943 | the hash table is inconsistent until we do so, and | |
944 | cselib_subst_to_values will need to do lookups. */ | |
945 | *slot = (void *) e; | |
946 | e->locs = new_elt_loc_list (e->locs, cselib_subst_to_values (x)); | |
947 | return e; | |
948 | } | |
949 | ||
950 | /* Invalidate any entries in reg_values that overlap REGNO. This is called | |
951 | if REGNO is changing. MODE is the mode of the assignment to REGNO, which | |
952 | is used to determine how many hard registers are being changed. If MODE | |
953 | is VOIDmode, then only REGNO is being changed; this is used when | |
954 | invalidating call clobbered registers across a call. */ | |
955 | ||
956 | static void | |
7080f735 | 957 | cselib_invalidate_regno (unsigned int regno, enum machine_mode mode) |
fa49fd0f RK |
958 | { |
959 | unsigned int endregno; | |
960 | unsigned int i; | |
961 | ||
962 | /* If we see pseudos after reload, something is _wrong_. */ | |
963 | if (reload_completed && regno >= FIRST_PSEUDO_REGISTER | |
964 | && reg_renumber[regno] >= 0) | |
965 | abort (); | |
966 | ||
967 | /* Determine the range of registers that must be invalidated. For | |
968 | pseudos, only REGNO is affected. For hard regs, we must take MODE | |
969 | into account, and we must also invalidate lower register numbers | |
970 | if they contain values that overlap REGNO. */ | |
291aac59 | 971 | if (regno < FIRST_PSEUDO_REGISTER) |
31825e57 | 972 | { |
291aac59 DC |
973 | if (mode == VOIDmode) |
974 | abort (); | |
7080f735 | 975 | |
31825e57 DM |
976 | if (regno < max_value_regs) |
977 | i = 0; | |
978 | else | |
979 | i = regno - max_value_regs; | |
fa49fd0f | 980 | |
31825e57 DM |
981 | endregno = regno + HARD_REGNO_NREGS (regno, mode); |
982 | } | |
983 | else | |
984 | { | |
985 | i = regno; | |
986 | endregno = regno + 1; | |
987 | } | |
988 | ||
989 | for (; i < endregno; i++) | |
fa49fd0f RK |
990 | { |
991 | struct elt_list **l = ®_VALUES (i); | |
992 | ||
993 | /* Go through all known values for this reg; if it overlaps the range | |
994 | we're invalidating, remove the value. */ | |
995 | while (*l) | |
996 | { | |
997 | cselib_val *v = (*l)->elt; | |
998 | struct elt_loc_list **p; | |
999 | unsigned int this_last = i; | |
1000 | ||
60fa6660 | 1001 | if (i < FIRST_PSEUDO_REGISTER && v != NULL) |
fa49fd0f RK |
1002 | this_last += HARD_REGNO_NREGS (i, GET_MODE (v->u.val_rtx)) - 1; |
1003 | ||
60fa6660 | 1004 | if (this_last < regno || v == NULL) |
fa49fd0f RK |
1005 | { |
1006 | l = &(*l)->next; | |
1007 | continue; | |
1008 | } | |
1009 | ||
1010 | /* We have an overlap. */ | |
60fa6660 AO |
1011 | if (*l == REG_VALUES (i)) |
1012 | { | |
1013 | /* Maintain the invariant that the first entry of | |
1014 | REG_VALUES, if present, must be the value used to set | |
1015 | the register, or NULL. This is also nice because | |
1016 | then we won't push the same regno onto user_regs | |
1017 | multiple times. */ | |
1018 | (*l)->elt = NULL; | |
1019 | l = &(*l)->next; | |
1020 | } | |
1021 | else | |
1022 | unchain_one_elt_list (l); | |
fa49fd0f RK |
1023 | |
1024 | /* Now, we clear the mapping from value to reg. It must exist, so | |
1025 | this code will crash intentionally if it doesn't. */ | |
1026 | for (p = &v->locs; ; p = &(*p)->next) | |
1027 | { | |
1028 | rtx x = (*p)->loc; | |
1029 | ||
1030 | if (GET_CODE (x) == REG && REGNO (x) == i) | |
1031 | { | |
1032 | unchain_one_elt_loc_list (p); | |
1033 | break; | |
1034 | } | |
1035 | } | |
1036 | if (v->locs == 0) | |
1037 | n_useless_values++; | |
1038 | } | |
1039 | } | |
1040 | } | |
9ddb66ca JH |
1041 | \f |
1042 | /* Return 1 if X has a value that can vary even between two | |
1043 | executions of the program. 0 means X can be compared reliably | |
1044 | against certain constants or near-constants. */ | |
fa49fd0f RK |
1045 | |
1046 | static int | |
9ddb66ca | 1047 | cselib_rtx_varies_p (rtx x ATTRIBUTE_UNUSED, int from_alias ATTRIBUTE_UNUSED) |
fa49fd0f | 1048 | { |
9ddb66ca JH |
1049 | /* We actually don't need to verify very hard. This is because |
1050 | if X has actually changed, we invalidate the memory anyway, | |
1051 | so assume that all common memory addresses are | |
1052 | invariant. */ | |
fa49fd0f RK |
1053 | return 0; |
1054 | } | |
1055 | ||
7101fb18 JH |
1056 | /* Invalidate any locations in the table which are changed because of a |
1057 | store to MEM_RTX. If this is called because of a non-const call | |
1058 | instruction, MEM_RTX is (mem:BLK const0_rtx). */ | |
fa49fd0f | 1059 | |
7101fb18 | 1060 | static void |
7080f735 | 1061 | cselib_invalidate_mem (rtx mem_rtx) |
fa49fd0f | 1062 | { |
7101fb18 | 1063 | cselib_val **vp, *v, *next; |
c65ecebc | 1064 | int num_mems = 0; |
9ddb66ca JH |
1065 | rtx mem_addr; |
1066 | ||
1067 | mem_addr = canon_rtx (get_addr (XEXP (mem_rtx, 0))); | |
1068 | mem_rtx = canon_rtx (mem_rtx); | |
fa49fd0f | 1069 | |
7101fb18 JH |
1070 | vp = &first_containing_mem; |
1071 | for (v = *vp; v != &dummy_val; v = next) | |
fa49fd0f | 1072 | { |
7101fb18 JH |
1073 | bool has_mem = false; |
1074 | struct elt_loc_list **p = &v->locs; | |
1075 | int had_locs = v->locs != 0; | |
fa49fd0f | 1076 | |
7101fb18 | 1077 | while (*p) |
fa49fd0f | 1078 | { |
7101fb18 | 1079 | rtx x = (*p)->loc; |
9ddb66ca | 1080 | rtx canon_x = (*p)->canon_loc; |
7101fb18 JH |
1081 | cselib_val *addr; |
1082 | struct elt_list **mem_chain; | |
1083 | ||
1084 | /* MEMs may occur in locations only at the top level; below | |
1085 | that every MEM or REG is substituted by its VALUE. */ | |
1086 | if (GET_CODE (x) != MEM) | |
fa49fd0f | 1087 | { |
7101fb18 JH |
1088 | p = &(*p)->next; |
1089 | continue; | |
1090 | } | |
9ddb66ca JH |
1091 | if (!canon_x) |
1092 | canon_x = (*p)->canon_loc = canon_rtx (x); | |
c65ecebc | 1093 | if (num_mems < PARAM_VALUE (PARAM_MAX_CSELIB_MEMORY_LOCATIONS) |
9ddb66ca JH |
1094 | && ! canon_true_dependence (mem_rtx, GET_MODE (mem_rtx), mem_addr, |
1095 | x, cselib_rtx_varies_p)) | |
7101fb18 JH |
1096 | { |
1097 | has_mem = true; | |
c65ecebc | 1098 | num_mems++; |
7101fb18 JH |
1099 | p = &(*p)->next; |
1100 | continue; | |
fa49fd0f RK |
1101 | } |
1102 | ||
7101fb18 JH |
1103 | /* This one overlaps. */ |
1104 | /* We must have a mapping from this MEM's address to the | |
1105 | value (E). Remove that, too. */ | |
1106 | addr = cselib_lookup (XEXP (x, 0), VOIDmode, 0); | |
1107 | mem_chain = &addr->addr_list; | |
1108 | for (;;) | |
1109 | { | |
1110 | if ((*mem_chain)->elt == v) | |
1111 | { | |
1112 | unchain_one_elt_list (mem_chain); | |
1113 | break; | |
1114 | } | |
fa49fd0f | 1115 | |
7101fb18 JH |
1116 | mem_chain = &(*mem_chain)->next; |
1117 | } | |
fa49fd0f | 1118 | |
7101fb18 JH |
1119 | unchain_one_elt_loc_list (p); |
1120 | } | |
fa49fd0f | 1121 | |
7101fb18 JH |
1122 | if (had_locs && v->locs == 0) |
1123 | n_useless_values++; | |
fa49fd0f | 1124 | |
7101fb18 JH |
1125 | next = v->next_containing_mem; |
1126 | if (has_mem) | |
1127 | { | |
1128 | *vp = v; | |
1129 | vp = &(*vp)->next_containing_mem; | |
1130 | } | |
1131 | else | |
1132 | v->next_containing_mem = NULL; | |
1133 | } | |
1134 | *vp = &dummy_val; | |
fa49fd0f RK |
1135 | } |
1136 | ||
1137 | /* Invalidate DEST, which is being assigned to or clobbered. The second and | |
1138 | the third parameter exist so that this function can be passed to | |
1139 | note_stores; they are ignored. */ | |
1140 | ||
1141 | static void | |
7080f735 AJ |
1142 | cselib_invalidate_rtx (rtx dest, rtx ignore ATTRIBUTE_UNUSED, |
1143 | void *data ATTRIBUTE_UNUSED) | |
fa49fd0f RK |
1144 | { |
1145 | while (GET_CODE (dest) == STRICT_LOW_PART || GET_CODE (dest) == SIGN_EXTRACT | |
1146 | || GET_CODE (dest) == ZERO_EXTRACT || GET_CODE (dest) == SUBREG) | |
1147 | dest = XEXP (dest, 0); | |
1148 | ||
1149 | if (GET_CODE (dest) == REG) | |
1150 | cselib_invalidate_regno (REGNO (dest), GET_MODE (dest)); | |
1151 | else if (GET_CODE (dest) == MEM) | |
1152 | cselib_invalidate_mem (dest); | |
1153 | ||
1154 | /* Some machines don't define AUTO_INC_DEC, but they still use push | |
1155 | instructions. We need to catch that case here in order to | |
1156 | invalidate the stack pointer correctly. Note that invalidating | |
1157 | the stack pointer is different from invalidating DEST. */ | |
1158 | if (push_operand (dest, GET_MODE (dest))) | |
1159 | cselib_invalidate_rtx (stack_pointer_rtx, NULL_RTX, NULL); | |
1160 | } | |
1161 | ||
1162 | /* Record the result of a SET instruction. DEST is being set; the source | |
1163 | contains the value described by SRC_ELT. If DEST is a MEM, DEST_ADDR_ELT | |
1164 | describes its address. */ | |
1165 | ||
1166 | static void | |
7080f735 | 1167 | cselib_record_set (rtx dest, cselib_val *src_elt, cselib_val *dest_addr_elt) |
fa49fd0f RK |
1168 | { |
1169 | int dreg = GET_CODE (dest) == REG ? (int) REGNO (dest) : -1; | |
1170 | ||
1171 | if (src_elt == 0 || side_effects_p (dest)) | |
1172 | return; | |
1173 | ||
1174 | if (dreg >= 0) | |
1175 | { | |
31825e57 DM |
1176 | if (dreg < FIRST_PSEUDO_REGISTER) |
1177 | { | |
1178 | unsigned int n = HARD_REGNO_NREGS (dreg, GET_MODE (dest)); | |
1179 | ||
1180 | if (n > max_value_regs) | |
1181 | max_value_regs = n; | |
1182 | } | |
1183 | ||
60fa6660 AO |
1184 | if (REG_VALUES (dreg) == 0) |
1185 | { | |
1186 | VARRAY_PUSH_UINT (used_regs, dreg); | |
1187 | REG_VALUES (dreg) = new_elt_list (REG_VALUES (dreg), src_elt); | |
1188 | } | |
1189 | else | |
1190 | { | |
1191 | if (REG_VALUES (dreg)->elt == 0) | |
1192 | REG_VALUES (dreg)->elt = src_elt; | |
1193 | else | |
1194 | /* The register should have been invalidated. */ | |
1195 | abort (); | |
1196 | } | |
1197 | ||
fa49fd0f RK |
1198 | if (src_elt->locs == 0) |
1199 | n_useless_values--; | |
1200 | src_elt->locs = new_elt_loc_list (src_elt->locs, dest); | |
1201 | } | |
1202 | else if (GET_CODE (dest) == MEM && dest_addr_elt != 0) | |
1203 | { | |
1204 | if (src_elt->locs == 0) | |
1205 | n_useless_values--; | |
1206 | add_mem_for_addr (dest_addr_elt, src_elt, dest); | |
1207 | } | |
1208 | } | |
1209 | ||
1210 | /* Describe a single set that is part of an insn. */ | |
1211 | struct set | |
1212 | { | |
1213 | rtx src; | |
1214 | rtx dest; | |
1215 | cselib_val *src_elt; | |
1216 | cselib_val *dest_addr_elt; | |
1217 | }; | |
1218 | ||
1219 | /* There is no good way to determine how many elements there can be | |
1220 | in a PARALLEL. Since it's fairly cheap, use a really large number. */ | |
1221 | #define MAX_SETS (FIRST_PSEUDO_REGISTER * 2) | |
1222 | ||
1223 | /* Record the effects of any sets in INSN. */ | |
1224 | static void | |
7080f735 | 1225 | cselib_record_sets (rtx insn) |
fa49fd0f RK |
1226 | { |
1227 | int n_sets = 0; | |
1228 | int i; | |
1229 | struct set sets[MAX_SETS]; | |
1230 | rtx body = PATTERN (insn); | |
b7933c21 | 1231 | rtx cond = 0; |
fa49fd0f RK |
1232 | |
1233 | body = PATTERN (insn); | |
b7933c21 BS |
1234 | if (GET_CODE (body) == COND_EXEC) |
1235 | { | |
1236 | cond = COND_EXEC_TEST (body); | |
1237 | body = COND_EXEC_CODE (body); | |
1238 | } | |
1239 | ||
fa49fd0f RK |
1240 | /* Find all sets. */ |
1241 | if (GET_CODE (body) == SET) | |
1242 | { | |
1243 | sets[0].src = SET_SRC (body); | |
1244 | sets[0].dest = SET_DEST (body); | |
1245 | n_sets = 1; | |
1246 | } | |
1247 | else if (GET_CODE (body) == PARALLEL) | |
1248 | { | |
1249 | /* Look through the PARALLEL and record the values being | |
1250 | set, if possible. Also handle any CLOBBERs. */ | |
1251 | for (i = XVECLEN (body, 0) - 1; i >= 0; --i) | |
1252 | { | |
1253 | rtx x = XVECEXP (body, 0, i); | |
1254 | ||
1255 | if (GET_CODE (x) == SET) | |
1256 | { | |
1257 | sets[n_sets].src = SET_SRC (x); | |
1258 | sets[n_sets].dest = SET_DEST (x); | |
1259 | n_sets++; | |
1260 | } | |
1261 | } | |
1262 | } | |
1263 | ||
1264 | /* Look up the values that are read. Do this before invalidating the | |
1265 | locations that are written. */ | |
1266 | for (i = 0; i < n_sets; i++) | |
1267 | { | |
1268 | rtx dest = sets[i].dest; | |
1269 | ||
1270 | /* A STRICT_LOW_PART can be ignored; we'll record the equivalence for | |
1271 | the low part after invalidating any knowledge about larger modes. */ | |
1272 | if (GET_CODE (sets[i].dest) == STRICT_LOW_PART) | |
1273 | sets[i].dest = dest = XEXP (dest, 0); | |
1274 | ||
1275 | /* We don't know how to record anything but REG or MEM. */ | |
1276 | if (GET_CODE (dest) == REG || GET_CODE (dest) == MEM) | |
1277 | { | |
b7933c21 BS |
1278 | rtx src = sets[i].src; |
1279 | if (cond) | |
1280 | src = gen_rtx_IF_THEN_ELSE (GET_MODE (src), cond, src, dest); | |
37060e78 | 1281 | sets[i].src_elt = cselib_lookup (src, GET_MODE (dest), 1); |
fa49fd0f RK |
1282 | if (GET_CODE (dest) == MEM) |
1283 | sets[i].dest_addr_elt = cselib_lookup (XEXP (dest, 0), Pmode, 1); | |
1284 | else | |
1285 | sets[i].dest_addr_elt = 0; | |
1286 | } | |
1287 | } | |
1288 | ||
1289 | /* Invalidate all locations written by this insn. Note that the elts we | |
1290 | looked up in the previous loop aren't affected, just some of their | |
1291 | locations may go away. */ | |
1292 | note_stores (body, cselib_invalidate_rtx, NULL); | |
1293 | ||
1294 | /* Now enter the equivalences in our tables. */ | |
1295 | for (i = 0; i < n_sets; i++) | |
1296 | { | |
1297 | rtx dest = sets[i].dest; | |
1298 | if (GET_CODE (dest) == REG || GET_CODE (dest) == MEM) | |
1299 | cselib_record_set (dest, sets[i].src_elt, sets[i].dest_addr_elt); | |
1300 | } | |
1301 | } | |
1302 | ||
1303 | /* Record the effects of INSN. */ | |
1304 | ||
1305 | void | |
7080f735 | 1306 | cselib_process_insn (rtx insn) |
fa49fd0f RK |
1307 | { |
1308 | int i; | |
1309 | rtx x; | |
1310 | ||
9635cfad JH |
1311 | if (find_reg_note (insn, REG_LIBCALL, NULL)) |
1312 | cselib_current_insn_in_libcall = true; | |
1313 | if (find_reg_note (insn, REG_RETVAL, NULL)) | |
1314 | cselib_current_insn_in_libcall = false; | |
fa49fd0f RK |
1315 | cselib_current_insn = insn; |
1316 | ||
1317 | /* Forget everything at a CODE_LABEL, a volatile asm, or a setjmp. */ | |
1318 | if (GET_CODE (insn) == CODE_LABEL | |
19652adf | 1319 | || (GET_CODE (insn) == CALL_INSN |
570a98eb | 1320 | && find_reg_note (insn, REG_SETJMP, NULL)) |
fa49fd0f RK |
1321 | || (GET_CODE (insn) == INSN |
1322 | && GET_CODE (PATTERN (insn)) == ASM_OPERANDS | |
1323 | && MEM_VOLATILE_P (PATTERN (insn)))) | |
1324 | { | |
cd648cec | 1325 | clear_table (); |
fa49fd0f RK |
1326 | return; |
1327 | } | |
1328 | ||
1329 | if (! INSN_P (insn)) | |
1330 | { | |
1331 | cselib_current_insn = 0; | |
1332 | return; | |
1333 | } | |
1334 | ||
1335 | /* If this is a call instruction, forget anything stored in a | |
1336 | call clobbered register, or, if this is not a const call, in | |
1337 | memory. */ | |
1338 | if (GET_CODE (insn) == CALL_INSN) | |
1339 | { | |
1340 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
1341 | if (call_used_regs[i]) | |
291aac59 | 1342 | cselib_invalidate_regno (i, reg_raw_mode[i]); |
fa49fd0f | 1343 | |
24a28584 | 1344 | if (! CONST_OR_PURE_CALL_P (insn)) |
fa49fd0f RK |
1345 | cselib_invalidate_mem (callmem); |
1346 | } | |
1347 | ||
1348 | cselib_record_sets (insn); | |
1349 | ||
1350 | #ifdef AUTO_INC_DEC | |
1351 | /* Clobber any registers which appear in REG_INC notes. We | |
1352 | could keep track of the changes to their values, but it is | |
1353 | unlikely to help. */ | |
1354 | for (x = REG_NOTES (insn); x; x = XEXP (x, 1)) | |
1355 | if (REG_NOTE_KIND (x) == REG_INC) | |
1356 | cselib_invalidate_rtx (XEXP (x, 0), NULL_RTX, NULL); | |
1357 | #endif | |
1358 | ||
1359 | /* Look for any CLOBBERs in CALL_INSN_FUNCTION_USAGE, but only | |
1360 | after we have processed the insn. */ | |
1361 | if (GET_CODE (insn) == CALL_INSN) | |
1362 | for (x = CALL_INSN_FUNCTION_USAGE (insn); x; x = XEXP (x, 1)) | |
1363 | if (GET_CODE (XEXP (x, 0)) == CLOBBER) | |
1364 | cselib_invalidate_rtx (XEXP (XEXP (x, 0), 0), NULL_RTX, NULL); | |
1365 | ||
1366 | cselib_current_insn = 0; | |
1367 | ||
1368 | if (n_useless_values > MAX_USELESS_VALUES) | |
1369 | remove_useless_values (); | |
1370 | } | |
1371 | ||
1372 | /* Make sure our varrays are big enough. Not called from any cselib routines; | |
1373 | it must be called by the user if it allocated new registers. */ | |
1374 | ||
1375 | void | |
7080f735 | 1376 | cselib_update_varray_sizes (void) |
fa49fd0f RK |
1377 | { |
1378 | unsigned int nregs = max_reg_num (); | |
1379 | ||
1380 | if (nregs == cselib_nregs) | |
1381 | return; | |
1382 | ||
1383 | cselib_nregs = nregs; | |
1384 | VARRAY_GROW (reg_values, nregs); | |
1385 | VARRAY_GROW (used_regs, nregs); | |
1386 | } | |
1387 | ||
1388 | /* Initialize cselib for one pass. The caller must also call | |
1389 | init_alias_analysis. */ | |
1390 | ||
1391 | void | |
7080f735 | 1392 | cselib_init (void) |
fa49fd0f | 1393 | { |
6a59927d JH |
1394 | elt_list_pool = create_alloc_pool ("elt_list", |
1395 | sizeof (struct elt_list), 10); | |
1396 | elt_loc_list_pool = create_alloc_pool ("elt_loc_list", | |
1397 | sizeof (struct elt_loc_list), 10); | |
1398 | cselib_val_pool = create_alloc_pool ("cselib_val_list", | |
1399 | sizeof (cselib_val), 10); | |
23bd7a93 JH |
1400 | value_pool = create_alloc_pool ("value", |
1401 | RTX_SIZE (VALUE), 100); | |
e2500fed | 1402 | /* This is only created once. */ |
fa49fd0f | 1403 | if (! callmem) |
e2500fed | 1404 | callmem = gen_rtx_MEM (BLKmode, const0_rtx); |
fa49fd0f RK |
1405 | |
1406 | cselib_nregs = max_reg_num (); | |
e2500fed GK |
1407 | if (reg_values_old != NULL && VARRAY_SIZE (reg_values_old) >= cselib_nregs) |
1408 | { | |
1409 | reg_values = reg_values_old; | |
1410 | used_regs = used_regs_old; | |
e2500fed GK |
1411 | } |
1412 | else | |
1413 | { | |
1414 | VARRAY_ELT_LIST_INIT (reg_values, cselib_nregs, "reg_values"); | |
1415 | VARRAY_UINT_INIT (used_regs, cselib_nregs, "used_regs"); | |
1416 | } | |
7080f735 | 1417 | hash_table = htab_create_ggc (31, get_value_hash, entry_and_rtx_equal_p, |
e2500fed | 1418 | NULL); |
9635cfad | 1419 | cselib_current_insn_in_libcall = false; |
fa49fd0f RK |
1420 | } |
1421 | ||
1422 | /* Called when the current user is done with cselib. */ | |
1423 | ||
1424 | void | |
7080f735 | 1425 | cselib_finish (void) |
fa49fd0f | 1426 | { |
6a59927d JH |
1427 | free_alloc_pool (elt_list_pool); |
1428 | free_alloc_pool (elt_loc_list_pool); | |
1429 | free_alloc_pool (cselib_val_pool); | |
23bd7a93 | 1430 | free_alloc_pool (value_pool); |
cd648cec | 1431 | clear_table (); |
e2500fed GK |
1432 | reg_values_old = reg_values; |
1433 | reg_values = 0; | |
1434 | used_regs_old = used_regs; | |
1435 | used_regs = 0; | |
1436 | hash_table = 0; | |
1437 | n_useless_values = 0; | |
1438 | next_unknown_value = 0; | |
fa49fd0f | 1439 | } |
e2500fed GK |
1440 | |
1441 | #include "gt-cselib.h" |