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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, | |
6fb5fa3c | 3 | 1999, 2000, 2001, 2003, 2004, 2005, 2006, 2007 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 | |
9dcd6f09 | 9 | Software Foundation; either version 3, or (at your option) any later |
1322177d | 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 | |
9dcd6f09 NC |
18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
fa49fd0f RK |
20 | |
21 | #include "config.h" | |
22 | #include "system.h" | |
4977bab6 ZW |
23 | #include "coretypes.h" |
24 | #include "tm.h" | |
fa49fd0f RK |
25 | |
26 | #include "rtl.h" | |
27 | #include "tm_p.h" | |
28 | #include "regs.h" | |
29 | #include "hard-reg-set.h" | |
30 | #include "flags.h" | |
31 | #include "real.h" | |
32 | #include "insn-config.h" | |
33 | #include "recog.h" | |
34 | #include "function.h" | |
78528714 | 35 | #include "emit-rtl.h" |
fa49fd0f RK |
36 | #include "toplev.h" |
37 | #include "output.h" | |
38 | #include "ggc.h" | |
fa49fd0f RK |
39 | #include "hashtab.h" |
40 | #include "cselib.h" | |
c65ecebc | 41 | #include "params.h" |
6a59927d | 42 | #include "alloc-pool.h" |
29c1846b | 43 | #include "target.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); | |
29c1846b | 57 | static unsigned int cselib_hash_rtx (rtx, 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. */ | |
7c514720 | 76 | static htab_t cselib_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; |
6fb5fa3c DB |
133 | |
134 | /* If nonnull, cselib will call this function before freeing useless | |
135 | VALUEs. A VALUE is deemed useless if its "locs" field is null. */ | |
136 | void (*cselib_discard_hook) (cselib_val *); | |
fa49fd0f RK |
137 | \f |
138 | ||
139 | /* Allocate a struct elt_list and fill in its two elements with the | |
140 | arguments. */ | |
141 | ||
6a59927d | 142 | static inline struct elt_list * |
7080f735 | 143 | new_elt_list (struct elt_list *next, cselib_val *elt) |
fa49fd0f | 144 | { |
6a59927d JH |
145 | struct elt_list *el; |
146 | el = pool_alloc (elt_list_pool); | |
fa49fd0f RK |
147 | el->next = next; |
148 | el->elt = elt; | |
149 | return el; | |
150 | } | |
151 | ||
152 | /* Allocate a struct elt_loc_list and fill in its two elements with the | |
153 | arguments. */ | |
154 | ||
6a59927d | 155 | static inline struct elt_loc_list * |
7080f735 | 156 | new_elt_loc_list (struct elt_loc_list *next, rtx loc) |
fa49fd0f | 157 | { |
6a59927d JH |
158 | struct elt_loc_list *el; |
159 | el = pool_alloc (elt_loc_list_pool); | |
fa49fd0f RK |
160 | el->next = next; |
161 | el->loc = loc; | |
162 | el->setting_insn = cselib_current_insn; | |
9635cfad | 163 | el->in_libcall = cselib_current_insn_in_libcall; |
fa49fd0f RK |
164 | return el; |
165 | } | |
166 | ||
167 | /* The elt_list at *PL is no longer needed. Unchain it and free its | |
168 | storage. */ | |
169 | ||
6a59927d | 170 | static inline void |
7080f735 | 171 | unchain_one_elt_list (struct elt_list **pl) |
fa49fd0f RK |
172 | { |
173 | struct elt_list *l = *pl; | |
174 | ||
175 | *pl = l->next; | |
6a59927d | 176 | pool_free (elt_list_pool, l); |
fa49fd0f RK |
177 | } |
178 | ||
179 | /* Likewise for elt_loc_lists. */ | |
180 | ||
181 | static void | |
7080f735 | 182 | unchain_one_elt_loc_list (struct elt_loc_list **pl) |
fa49fd0f RK |
183 | { |
184 | struct elt_loc_list *l = *pl; | |
185 | ||
186 | *pl = l->next; | |
6a59927d | 187 | pool_free (elt_loc_list_pool, l); |
fa49fd0f RK |
188 | } |
189 | ||
190 | /* Likewise for cselib_vals. This also frees the addr_list associated with | |
191 | V. */ | |
192 | ||
193 | static void | |
7080f735 | 194 | unchain_one_value (cselib_val *v) |
fa49fd0f RK |
195 | { |
196 | while (v->addr_list) | |
197 | unchain_one_elt_list (&v->addr_list); | |
198 | ||
6a59927d | 199 | pool_free (cselib_val_pool, v); |
fa49fd0f RK |
200 | } |
201 | ||
202 | /* Remove all entries from the hash table. Also used during | |
203 | initialization. If CLEAR_ALL isn't set, then only clear the entries | |
204 | which are known to have been used. */ | |
205 | ||
eb232f4e SB |
206 | void |
207 | cselib_clear_table (void) | |
fa49fd0f RK |
208 | { |
209 | unsigned int i; | |
210 | ||
6790d1ab JH |
211 | for (i = 0; i < n_used_regs; i++) |
212 | REG_VALUES (used_regs[i]) = 0; | |
fa49fd0f | 213 | |
31825e57 DM |
214 | max_value_regs = 0; |
215 | ||
6790d1ab | 216 | n_used_regs = 0; |
fa49fd0f | 217 | |
7c514720 | 218 | htab_empty (cselib_hash_table); |
fa49fd0f | 219 | |
fa49fd0f RK |
220 | n_useless_values = 0; |
221 | ||
222 | next_unknown_value = 0; | |
7101fb18 JH |
223 | |
224 | first_containing_mem = &dummy_val; | |
fa49fd0f RK |
225 | } |
226 | ||
227 | /* The equality test for our hash table. The first argument ENTRY is a table | |
228 | element (i.e. a cselib_val), while the second arg X is an rtx. We know | |
229 | that all callers of htab_find_slot_with_hash will wrap CONST_INTs into a | |
230 | CONST of an appropriate mode. */ | |
231 | ||
232 | static int | |
7080f735 | 233 | entry_and_rtx_equal_p (const void *entry, const void *x_arg) |
fa49fd0f RK |
234 | { |
235 | struct elt_loc_list *l; | |
e5cfc29f | 236 | const cselib_val *const v = (const cselib_val *) entry; |
fa49fd0f RK |
237 | rtx x = (rtx) x_arg; |
238 | enum machine_mode mode = GET_MODE (x); | |
239 | ||
091a3ac7 | 240 | gcc_assert (GET_CODE (x) != CONST_INT && GET_CODE (x) != CONST_FIXED |
341c100f NS |
241 | && (mode != VOIDmode || GET_CODE (x) != CONST_DOUBLE)); |
242 | ||
757bbef8 | 243 | if (mode != GET_MODE (v->val_rtx)) |
fa49fd0f RK |
244 | return 0; |
245 | ||
246 | /* Unwrap X if necessary. */ | |
247 | if (GET_CODE (x) == CONST | |
248 | && (GET_CODE (XEXP (x, 0)) == CONST_INT | |
091a3ac7 | 249 | || GET_CODE (XEXP (x, 0)) == CONST_FIXED |
fa49fd0f RK |
250 | || GET_CODE (XEXP (x, 0)) == CONST_DOUBLE)) |
251 | x = XEXP (x, 0); | |
7080f735 | 252 | |
fa49fd0f RK |
253 | /* We don't guarantee that distinct rtx's have different hash values, |
254 | so we need to do a comparison. */ | |
255 | for (l = v->locs; l; l = l->next) | |
256 | if (rtx_equal_for_cselib_p (l->loc, x)) | |
257 | return 1; | |
258 | ||
259 | return 0; | |
260 | } | |
261 | ||
262 | /* The hash function for our hash table. The value is always computed with | |
0516f6fe SB |
263 | cselib_hash_rtx when adding an element; this function just extracts the |
264 | hash value from a cselib_val structure. */ | |
fa49fd0f | 265 | |
fb7e6024 | 266 | static hashval_t |
7080f735 | 267 | get_value_hash (const void *entry) |
fa49fd0f | 268 | { |
4f588890 | 269 | const cselib_val *const v = (const cselib_val *) entry; |
fa49fd0f RK |
270 | return v->value; |
271 | } | |
272 | ||
273 | /* Return true if X contains a VALUE rtx. If ONLY_USELESS is set, we | |
274 | only return true for values which point to a cselib_val whose value | |
275 | element has been set to zero, which implies the cselib_val will be | |
276 | removed. */ | |
277 | ||
278 | int | |
4f588890 | 279 | references_value_p (const_rtx x, int only_useless) |
fa49fd0f | 280 | { |
4f588890 | 281 | const enum rtx_code code = GET_CODE (x); |
fa49fd0f RK |
282 | const char *fmt = GET_RTX_FORMAT (code); |
283 | int i, j; | |
284 | ||
285 | if (GET_CODE (x) == VALUE | |
286 | && (! only_useless || CSELIB_VAL_PTR (x)->locs == 0)) | |
287 | return 1; | |
288 | ||
289 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
290 | { | |
291 | if (fmt[i] == 'e' && references_value_p (XEXP (x, i), only_useless)) | |
292 | return 1; | |
293 | else if (fmt[i] == 'E') | |
294 | for (j = 0; j < XVECLEN (x, i); j++) | |
295 | if (references_value_p (XVECEXP (x, i, j), only_useless)) | |
296 | return 1; | |
297 | } | |
298 | ||
299 | return 0; | |
300 | } | |
301 | ||
302 | /* For all locations found in X, delete locations that reference useless | |
303 | values (i.e. values without any location). Called through | |
304 | htab_traverse. */ | |
305 | ||
306 | static int | |
7080f735 | 307 | discard_useless_locs (void **x, void *info ATTRIBUTE_UNUSED) |
fa49fd0f RK |
308 | { |
309 | cselib_val *v = (cselib_val *)*x; | |
310 | struct elt_loc_list **p = &v->locs; | |
311 | int had_locs = v->locs != 0; | |
312 | ||
313 | while (*p) | |
314 | { | |
315 | if (references_value_p ((*p)->loc, 1)) | |
316 | unchain_one_elt_loc_list (p); | |
317 | else | |
318 | p = &(*p)->next; | |
319 | } | |
320 | ||
321 | if (had_locs && v->locs == 0) | |
322 | { | |
323 | n_useless_values++; | |
324 | values_became_useless = 1; | |
325 | } | |
326 | return 1; | |
327 | } | |
328 | ||
329 | /* If X is a value with no locations, remove it from the hashtable. */ | |
330 | ||
331 | static int | |
7080f735 | 332 | discard_useless_values (void **x, void *info ATTRIBUTE_UNUSED) |
fa49fd0f RK |
333 | { |
334 | cselib_val *v = (cselib_val *)*x; | |
335 | ||
336 | if (v->locs == 0) | |
337 | { | |
6fb5fa3c DB |
338 | if (cselib_discard_hook) |
339 | cselib_discard_hook (v); | |
340 | ||
757bbef8 | 341 | CSELIB_VAL_PTR (v->val_rtx) = NULL; |
7c514720 | 342 | htab_clear_slot (cselib_hash_table, x); |
fa49fd0f RK |
343 | unchain_one_value (v); |
344 | n_useless_values--; | |
345 | } | |
346 | ||
347 | return 1; | |
348 | } | |
349 | ||
350 | /* Clean out useless values (i.e. those which no longer have locations | |
351 | associated with them) from the hash table. */ | |
352 | ||
353 | static void | |
7080f735 | 354 | remove_useless_values (void) |
fa49fd0f | 355 | { |
7101fb18 | 356 | cselib_val **p, *v; |
fa49fd0f RK |
357 | /* First pass: eliminate locations that reference the value. That in |
358 | turn can make more values useless. */ | |
359 | do | |
360 | { | |
361 | values_became_useless = 0; | |
7c514720 | 362 | htab_traverse (cselib_hash_table, discard_useless_locs, 0); |
fa49fd0f RK |
363 | } |
364 | while (values_became_useless); | |
365 | ||
366 | /* Second pass: actually remove the values. */ | |
fa49fd0f | 367 | |
7101fb18 JH |
368 | p = &first_containing_mem; |
369 | for (v = *p; v != &dummy_val; v = v->next_containing_mem) | |
370 | if (v->locs) | |
371 | { | |
372 | *p = v; | |
373 | p = &(*p)->next_containing_mem; | |
374 | } | |
375 | *p = &dummy_val; | |
376 | ||
7c514720 | 377 | htab_traverse (cselib_hash_table, discard_useless_values, 0); |
3e2a0bd2 | 378 | |
341c100f | 379 | gcc_assert (!n_useless_values); |
fa49fd0f RK |
380 | } |
381 | ||
60fa6660 AO |
382 | /* Return the mode in which a register was last set. If X is not a |
383 | register, return its mode. If the mode in which the register was | |
384 | set is not known, or the value was already clobbered, return | |
385 | VOIDmode. */ | |
386 | ||
387 | enum machine_mode | |
4f588890 | 388 | cselib_reg_set_mode (const_rtx x) |
60fa6660 | 389 | { |
f8cfc6aa | 390 | if (!REG_P (x)) |
60fa6660 AO |
391 | return GET_MODE (x); |
392 | ||
393 | if (REG_VALUES (REGNO (x)) == NULL | |
394 | || REG_VALUES (REGNO (x))->elt == NULL) | |
395 | return VOIDmode; | |
396 | ||
757bbef8 | 397 | return GET_MODE (REG_VALUES (REGNO (x))->elt->val_rtx); |
60fa6660 AO |
398 | } |
399 | ||
fa49fd0f RK |
400 | /* Return nonzero if we can prove that X and Y contain the same value, taking |
401 | our gathered information into account. */ | |
402 | ||
403 | int | |
7080f735 | 404 | rtx_equal_for_cselib_p (rtx x, rtx y) |
fa49fd0f RK |
405 | { |
406 | enum rtx_code code; | |
407 | const char *fmt; | |
408 | int i; | |
7080f735 | 409 | |
f8cfc6aa | 410 | if (REG_P (x) || MEM_P (x)) |
fa49fd0f RK |
411 | { |
412 | cselib_val *e = cselib_lookup (x, GET_MODE (x), 0); | |
413 | ||
414 | if (e) | |
757bbef8 | 415 | x = e->val_rtx; |
fa49fd0f RK |
416 | } |
417 | ||
f8cfc6aa | 418 | if (REG_P (y) || MEM_P (y)) |
fa49fd0f RK |
419 | { |
420 | cselib_val *e = cselib_lookup (y, GET_MODE (y), 0); | |
421 | ||
422 | if (e) | |
757bbef8 | 423 | y = e->val_rtx; |
fa49fd0f RK |
424 | } |
425 | ||
426 | if (x == y) | |
427 | return 1; | |
428 | ||
429 | if (GET_CODE (x) == VALUE && GET_CODE (y) == VALUE) | |
430 | return CSELIB_VAL_PTR (x) == CSELIB_VAL_PTR (y); | |
431 | ||
432 | if (GET_CODE (x) == VALUE) | |
433 | { | |
434 | cselib_val *e = CSELIB_VAL_PTR (x); | |
435 | struct elt_loc_list *l; | |
436 | ||
437 | for (l = e->locs; l; l = l->next) | |
438 | { | |
439 | rtx t = l->loc; | |
440 | ||
441 | /* Avoid infinite recursion. */ | |
3c0cb5de | 442 | if (REG_P (t) || MEM_P (t)) |
fa49fd0f RK |
443 | continue; |
444 | else if (rtx_equal_for_cselib_p (t, y)) | |
445 | return 1; | |
446 | } | |
7080f735 | 447 | |
fa49fd0f RK |
448 | return 0; |
449 | } | |
450 | ||
451 | if (GET_CODE (y) == VALUE) | |
452 | { | |
453 | cselib_val *e = CSELIB_VAL_PTR (y); | |
454 | struct elt_loc_list *l; | |
455 | ||
456 | for (l = e->locs; l; l = l->next) | |
457 | { | |
458 | rtx t = l->loc; | |
459 | ||
3c0cb5de | 460 | if (REG_P (t) || MEM_P (t)) |
fa49fd0f RK |
461 | continue; |
462 | else if (rtx_equal_for_cselib_p (x, t)) | |
463 | return 1; | |
464 | } | |
7080f735 | 465 | |
fa49fd0f RK |
466 | return 0; |
467 | } | |
468 | ||
469 | if (GET_CODE (x) != GET_CODE (y) || GET_MODE (x) != GET_MODE (y)) | |
470 | return 0; | |
471 | ||
37cf6116 RH |
472 | /* These won't be handled correctly by the code below. */ |
473 | switch (GET_CODE (x)) | |
474 | { | |
475 | case CONST_DOUBLE: | |
091a3ac7 | 476 | case CONST_FIXED: |
37cf6116 RH |
477 | return 0; |
478 | ||
479 | case LABEL_REF: | |
480 | return XEXP (x, 0) == XEXP (y, 0); | |
481 | ||
482 | default: | |
483 | break; | |
484 | } | |
7080f735 | 485 | |
fa49fd0f RK |
486 | code = GET_CODE (x); |
487 | fmt = GET_RTX_FORMAT (code); | |
488 | ||
489 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
490 | { | |
491 | int j; | |
492 | ||
493 | switch (fmt[i]) | |
494 | { | |
495 | case 'w': | |
496 | if (XWINT (x, i) != XWINT (y, i)) | |
497 | return 0; | |
498 | break; | |
499 | ||
500 | case 'n': | |
501 | case 'i': | |
502 | if (XINT (x, i) != XINT (y, i)) | |
503 | return 0; | |
504 | break; | |
505 | ||
506 | case 'V': | |
507 | case 'E': | |
508 | /* Two vectors must have the same length. */ | |
509 | if (XVECLEN (x, i) != XVECLEN (y, i)) | |
510 | return 0; | |
511 | ||
512 | /* And the corresponding elements must match. */ | |
513 | for (j = 0; j < XVECLEN (x, i); j++) | |
514 | if (! rtx_equal_for_cselib_p (XVECEXP (x, i, j), | |
515 | XVECEXP (y, i, j))) | |
516 | return 0; | |
517 | break; | |
518 | ||
519 | case 'e': | |
29c1846b R |
520 | if (i == 1 |
521 | && targetm.commutative_p (x, UNKNOWN) | |
522 | && rtx_equal_for_cselib_p (XEXP (x, 1), XEXP (y, 0)) | |
523 | && rtx_equal_for_cselib_p (XEXP (x, 0), XEXP (y, 1))) | |
524 | return 1; | |
fa49fd0f RK |
525 | if (! rtx_equal_for_cselib_p (XEXP (x, i), XEXP (y, i))) |
526 | return 0; | |
527 | break; | |
528 | ||
529 | case 'S': | |
530 | case 's': | |
531 | if (strcmp (XSTR (x, i), XSTR (y, i))) | |
532 | return 0; | |
533 | break; | |
534 | ||
535 | case 'u': | |
536 | /* These are just backpointers, so they don't matter. */ | |
537 | break; | |
538 | ||
539 | case '0': | |
540 | case 't': | |
541 | break; | |
542 | ||
543 | /* It is believed that rtx's at this level will never | |
544 | contain anything but integers and other rtx's, | |
545 | except for within LABEL_REFs and SYMBOL_REFs. */ | |
546 | default: | |
341c100f | 547 | gcc_unreachable (); |
fa49fd0f RK |
548 | } |
549 | } | |
550 | return 1; | |
551 | } | |
552 | ||
553 | /* We need to pass down the mode of constants through the hash table | |
554 | functions. For that purpose, wrap them in a CONST of the appropriate | |
555 | mode. */ | |
556 | static rtx | |
7080f735 | 557 | wrap_constant (enum machine_mode mode, rtx x) |
fa49fd0f | 558 | { |
091a3ac7 | 559 | if (GET_CODE (x) != CONST_INT && GET_CODE (x) != CONST_FIXED |
fa49fd0f RK |
560 | && (GET_CODE (x) != CONST_DOUBLE || GET_MODE (x) != VOIDmode)) |
561 | return x; | |
341c100f | 562 | gcc_assert (mode != VOIDmode); |
fa49fd0f RK |
563 | return gen_rtx_CONST (mode, x); |
564 | } | |
565 | ||
566 | /* Hash an rtx. Return 0 if we couldn't hash the rtx. | |
567 | For registers and memory locations, we look up their cselib_val structure | |
568 | and return its VALUE element. | |
569 | Possible reasons for return 0 are: the object is volatile, or we couldn't | |
570 | find a register or memory location in the table and CREATE is zero. If | |
571 | CREATE is nonzero, table elts are created for regs and mem. | |
29c1846b R |
572 | N.B. this hash function returns the same hash value for RTXes that |
573 | differ only in the order of operands, thus it is suitable for comparisons | |
574 | that take commutativity into account. | |
575 | If we wanted to also support associative rules, we'd have to use a different | |
576 | strategy to avoid returning spurious 0, e.g. return ~(~0U >> 1) . | |
577 | We used to have a MODE argument for hashing for CONST_INTs, but that | |
578 | didn't make sense, since it caused spurious hash differences between | |
579 | (set (reg:SI 1) (const_int)) | |
580 | (plus:SI (reg:SI 2) (reg:SI 1)) | |
581 | and | |
582 | (plus:SI (reg:SI 2) (const_int)) | |
583 | If the mode is important in any context, it must be checked specifically | |
584 | in a comparison anyway, since relying on hash differences is unsafe. */ | |
fa49fd0f RK |
585 | |
586 | static unsigned int | |
29c1846b | 587 | cselib_hash_rtx (rtx x, int create) |
fa49fd0f RK |
588 | { |
589 | cselib_val *e; | |
590 | int i, j; | |
591 | enum rtx_code code; | |
592 | const char *fmt; | |
593 | unsigned int hash = 0; | |
594 | ||
fa49fd0f RK |
595 | code = GET_CODE (x); |
596 | hash += (unsigned) code + (unsigned) GET_MODE (x); | |
597 | ||
598 | switch (code) | |
599 | { | |
600 | case MEM: | |
601 | case REG: | |
602 | e = cselib_lookup (x, GET_MODE (x), create); | |
603 | if (! e) | |
604 | return 0; | |
605 | ||
a4f4333a | 606 | return e->value; |
fa49fd0f RK |
607 | |
608 | case CONST_INT: | |
29c1846b | 609 | hash += ((unsigned) CONST_INT << 7) + INTVAL (x); |
dc76f41c | 610 | return hash ? hash : (unsigned int) CONST_INT; |
fa49fd0f RK |
611 | |
612 | case CONST_DOUBLE: | |
613 | /* This is like the general case, except that it only counts | |
614 | the integers representing the constant. */ | |
615 | hash += (unsigned) code + (unsigned) GET_MODE (x); | |
616 | if (GET_MODE (x) != VOIDmode) | |
46b33600 | 617 | hash += real_hash (CONST_DOUBLE_REAL_VALUE (x)); |
fa49fd0f RK |
618 | else |
619 | hash += ((unsigned) CONST_DOUBLE_LOW (x) | |
620 | + (unsigned) CONST_DOUBLE_HIGH (x)); | |
dc76f41c | 621 | return hash ? hash : (unsigned int) CONST_DOUBLE; |
fa49fd0f | 622 | |
091a3ac7 CF |
623 | case CONST_FIXED: |
624 | hash += (unsigned int) code + (unsigned int) GET_MODE (x); | |
625 | hash += fixed_hash (CONST_FIXED_VALUE (x)); | |
626 | return hash ? hash : (unsigned int) CONST_FIXED; | |
627 | ||
69ef87e2 AH |
628 | case CONST_VECTOR: |
629 | { | |
630 | int units; | |
631 | rtx elt; | |
632 | ||
633 | units = CONST_VECTOR_NUNITS (x); | |
634 | ||
635 | for (i = 0; i < units; ++i) | |
636 | { | |
637 | elt = CONST_VECTOR_ELT (x, i); | |
29c1846b | 638 | hash += cselib_hash_rtx (elt, 0); |
69ef87e2 AH |
639 | } |
640 | ||
641 | return hash; | |
642 | } | |
643 | ||
fa49fd0f RK |
644 | /* Assume there is only one rtx object for any given label. */ |
645 | case LABEL_REF: | |
4c6669c2 RS |
646 | /* We don't hash on the address of the CODE_LABEL to avoid bootstrap |
647 | differences and differences between each stage's debugging dumps. */ | |
648 | hash += (((unsigned int) LABEL_REF << 7) | |
649 | + CODE_LABEL_NUMBER (XEXP (x, 0))); | |
dc76f41c | 650 | return hash ? hash : (unsigned int) LABEL_REF; |
fa49fd0f RK |
651 | |
652 | case SYMBOL_REF: | |
4c6669c2 RS |
653 | { |
654 | /* Don't hash on the symbol's address to avoid bootstrap differences. | |
655 | Different hash values may cause expressions to be recorded in | |
656 | different orders and thus different registers to be used in the | |
657 | final assembler. This also avoids differences in the dump files | |
658 | between various stages. */ | |
659 | unsigned int h = 0; | |
660 | const unsigned char *p = (const unsigned char *) XSTR (x, 0); | |
661 | ||
662 | while (*p) | |
663 | h += (h << 7) + *p++; /* ??? revisit */ | |
664 | ||
665 | hash += ((unsigned int) SYMBOL_REF << 7) + h; | |
666 | return hash ? hash : (unsigned int) SYMBOL_REF; | |
667 | } | |
fa49fd0f RK |
668 | |
669 | case PRE_DEC: | |
670 | case PRE_INC: | |
671 | case POST_DEC: | |
672 | case POST_INC: | |
673 | case POST_MODIFY: | |
674 | case PRE_MODIFY: | |
675 | case PC: | |
676 | case CC0: | |
677 | case CALL: | |
678 | case UNSPEC_VOLATILE: | |
679 | return 0; | |
680 | ||
681 | case ASM_OPERANDS: | |
682 | if (MEM_VOLATILE_P (x)) | |
683 | return 0; | |
684 | ||
685 | break; | |
7080f735 | 686 | |
fa49fd0f RK |
687 | default: |
688 | break; | |
689 | } | |
690 | ||
691 | i = GET_RTX_LENGTH (code) - 1; | |
692 | fmt = GET_RTX_FORMAT (code); | |
693 | for (; i >= 0; i--) | |
694 | { | |
341c100f | 695 | switch (fmt[i]) |
fa49fd0f | 696 | { |
341c100f | 697 | case 'e': |
fa49fd0f | 698 | { |
341c100f | 699 | rtx tem = XEXP (x, i); |
29c1846b | 700 | unsigned int tem_hash = cselib_hash_rtx (tem, create); |
341c100f | 701 | |
fa49fd0f RK |
702 | if (tem_hash == 0) |
703 | return 0; | |
341c100f | 704 | |
fa49fd0f RK |
705 | hash += tem_hash; |
706 | } | |
341c100f NS |
707 | break; |
708 | case 'E': | |
709 | for (j = 0; j < XVECLEN (x, i); j++) | |
710 | { | |
711 | unsigned int tem_hash | |
29c1846b | 712 | = cselib_hash_rtx (XVECEXP (x, i, j), create); |
341c100f NS |
713 | |
714 | if (tem_hash == 0) | |
715 | return 0; | |
716 | ||
717 | hash += tem_hash; | |
718 | } | |
719 | break; | |
fa49fd0f | 720 | |
341c100f NS |
721 | case 's': |
722 | { | |
723 | const unsigned char *p = (const unsigned char *) XSTR (x, i); | |
724 | ||
725 | if (p) | |
726 | while (*p) | |
727 | hash += *p++; | |
728 | break; | |
729 | } | |
730 | ||
731 | case 'i': | |
732 | hash += XINT (x, i); | |
733 | break; | |
734 | ||
735 | case '0': | |
736 | case 't': | |
737 | /* unused */ | |
738 | break; | |
739 | ||
740 | default: | |
741 | gcc_unreachable (); | |
fa49fd0f | 742 | } |
fa49fd0f RK |
743 | } |
744 | ||
dc76f41c | 745 | return hash ? hash : 1 + (unsigned int) GET_CODE (x); |
fa49fd0f RK |
746 | } |
747 | ||
748 | /* Create a new value structure for VALUE and initialize it. The mode of the | |
749 | value is MODE. */ | |
750 | ||
6a59927d | 751 | static inline cselib_val * |
7080f735 | 752 | new_cselib_val (unsigned int value, enum machine_mode mode) |
fa49fd0f | 753 | { |
6a59927d | 754 | cselib_val *e = pool_alloc (cselib_val_pool); |
fa49fd0f | 755 | |
341c100f | 756 | gcc_assert (value); |
fa49fd0f RK |
757 | |
758 | e->value = value; | |
d67fb775 SB |
759 | /* We use an alloc pool to allocate this RTL construct because it |
760 | accounts for about 8% of the overall memory usage. We know | |
761 | precisely when we can have VALUE RTXen (when cselib is active) | |
daa956d0 | 762 | so we don't need to put them in garbage collected memory. |
d67fb775 | 763 | ??? Why should a VALUE be an RTX in the first place? */ |
757bbef8 SB |
764 | e->val_rtx = pool_alloc (value_pool); |
765 | memset (e->val_rtx, 0, RTX_HDR_SIZE); | |
766 | PUT_CODE (e->val_rtx, VALUE); | |
767 | PUT_MODE (e->val_rtx, mode); | |
768 | CSELIB_VAL_PTR (e->val_rtx) = e; | |
fa49fd0f RK |
769 | e->addr_list = 0; |
770 | e->locs = 0; | |
7101fb18 | 771 | e->next_containing_mem = 0; |
fa49fd0f RK |
772 | return e; |
773 | } | |
774 | ||
775 | /* ADDR_ELT is a value that is used as address. MEM_ELT is the value that | |
776 | contains the data at this address. X is a MEM that represents the | |
777 | value. Update the two value structures to represent this situation. */ | |
778 | ||
779 | static void | |
7080f735 | 780 | add_mem_for_addr (cselib_val *addr_elt, cselib_val *mem_elt, rtx x) |
fa49fd0f | 781 | { |
fa49fd0f RK |
782 | struct elt_loc_list *l; |
783 | ||
784 | /* Avoid duplicates. */ | |
785 | for (l = mem_elt->locs; l; l = l->next) | |
3c0cb5de | 786 | if (MEM_P (l->loc) |
fa49fd0f RK |
787 | && CSELIB_VAL_PTR (XEXP (l->loc, 0)) == addr_elt) |
788 | return; | |
789 | ||
fa49fd0f | 790 | addr_elt->addr_list = new_elt_list (addr_elt->addr_list, mem_elt); |
f1ec5147 RK |
791 | mem_elt->locs |
792 | = new_elt_loc_list (mem_elt->locs, | |
757bbef8 | 793 | replace_equiv_address_nv (x, addr_elt->val_rtx)); |
7101fb18 JH |
794 | if (mem_elt->next_containing_mem == NULL) |
795 | { | |
796 | mem_elt->next_containing_mem = first_containing_mem; | |
797 | first_containing_mem = mem_elt; | |
798 | } | |
fa49fd0f RK |
799 | } |
800 | ||
801 | /* Subroutine of cselib_lookup. Return a value for X, which is a MEM rtx. | |
802 | If CREATE, make a new one if we haven't seen it before. */ | |
803 | ||
804 | static cselib_val * | |
7080f735 | 805 | cselib_lookup_mem (rtx x, int create) |
fa49fd0f RK |
806 | { |
807 | enum machine_mode mode = GET_MODE (x); | |
808 | void **slot; | |
809 | cselib_val *addr; | |
810 | cselib_val *mem_elt; | |
811 | struct elt_list *l; | |
812 | ||
813 | if (MEM_VOLATILE_P (x) || mode == BLKmode | |
463301c3 | 814 | || !cselib_record_memory |
fa49fd0f RK |
815 | || (FLOAT_MODE_P (mode) && flag_float_store)) |
816 | return 0; | |
817 | ||
818 | /* Look up the value for the address. */ | |
819 | addr = cselib_lookup (XEXP (x, 0), mode, create); | |
820 | if (! addr) | |
821 | return 0; | |
822 | ||
823 | /* Find a value that describes a value of our mode at that address. */ | |
824 | for (l = addr->addr_list; l; l = l->next) | |
757bbef8 | 825 | if (GET_MODE (l->elt->val_rtx) == mode) |
fa49fd0f RK |
826 | return l->elt; |
827 | ||
828 | if (! create) | |
829 | return 0; | |
830 | ||
831 | mem_elt = new_cselib_val (++next_unknown_value, mode); | |
832 | add_mem_for_addr (addr, mem_elt, x); | |
7c514720 | 833 | slot = htab_find_slot_with_hash (cselib_hash_table, wrap_constant (mode, x), |
fa49fd0f RK |
834 | mem_elt->value, INSERT); |
835 | *slot = mem_elt; | |
836 | return mem_elt; | |
837 | } | |
838 | ||
6fb5fa3c DB |
839 | /* Search thru the possible substitutions in P. We prefer a non reg |
840 | substitution because this allows us to expand the tree further. If | |
841 | we find, just a reg, take the lowest regno. There may be several | |
842 | non-reg results, we just take the first one because they will all | |
843 | expand to the same place. */ | |
844 | ||
845 | static rtx | |
846 | expand_loc (struct elt_loc_list *p, bitmap regs_active, int max_depth) | |
847 | { | |
848 | rtx reg_result = NULL; | |
849 | unsigned int regno = UINT_MAX; | |
850 | struct elt_loc_list *p_in = p; | |
851 | ||
852 | for (; p; p = p -> next) | |
853 | { | |
854 | /* Avoid infinite recursion trying to expand a reg into a | |
855 | the same reg. */ | |
856 | if ((REG_P (p->loc)) | |
857 | && (REGNO (p->loc) < regno) | |
858 | && !bitmap_bit_p (regs_active, REGNO (p->loc))) | |
859 | { | |
860 | reg_result = p->loc; | |
861 | regno = REGNO (p->loc); | |
862 | } | |
863 | /* Avoid infinite recursion and do not try to expand the | |
864 | value. */ | |
865 | else if (GET_CODE (p->loc) == VALUE | |
866 | && CSELIB_VAL_PTR (p->loc)->locs == p_in) | |
867 | continue; | |
868 | else if (!REG_P (p->loc)) | |
869 | { | |
870 | rtx result; | |
871 | if (dump_file) | |
872 | { | |
873 | print_inline_rtx (dump_file, p->loc, 0); | |
874 | fprintf (dump_file, "\n"); | |
875 | } | |
876 | result = cselib_expand_value_rtx (p->loc, regs_active, max_depth - 1); | |
877 | if (result) | |
878 | return result; | |
879 | } | |
880 | ||
881 | } | |
882 | ||
883 | if (regno != UINT_MAX) | |
884 | { | |
885 | rtx result; | |
886 | if (dump_file) | |
887 | fprintf (dump_file, "r%d\n", regno); | |
888 | ||
889 | result = cselib_expand_value_rtx (reg_result, regs_active, max_depth - 1); | |
890 | if (result) | |
891 | return result; | |
892 | } | |
893 | ||
894 | if (dump_file) | |
895 | { | |
896 | if (reg_result) | |
897 | { | |
898 | print_inline_rtx (dump_file, reg_result, 0); | |
899 | fprintf (dump_file, "\n"); | |
900 | } | |
901 | else | |
902 | fprintf (dump_file, "NULL\n"); | |
903 | } | |
904 | return reg_result; | |
905 | } | |
906 | ||
907 | ||
908 | /* Forward substitute and expand an expression out to its roots. | |
909 | This is the opposite of common subexpression. Because local value | |
910 | numbering is such a weak optimization, the expanded expression is | |
911 | pretty much unique (not from a pointer equals point of view but | |
912 | from a tree shape point of view. | |
913 | ||
914 | This function returns NULL if the expansion fails. The expansion | |
915 | will fail if there is no value number for one of the operands or if | |
916 | one of the operands has been overwritten between the current insn | |
917 | and the beginning of the basic block. For instance x has no | |
918 | expansion in: | |
919 | ||
920 | r1 <- r1 + 3 | |
921 | x <- r1 + 8 | |
922 | ||
923 | REGS_ACTIVE is a scratch bitmap that should be clear when passing in. | |
924 | It is clear on return. */ | |
925 | ||
926 | rtx | |
927 | cselib_expand_value_rtx (rtx orig, bitmap regs_active, int max_depth) | |
928 | { | |
929 | rtx copy, scopy; | |
930 | int i, j; | |
931 | RTX_CODE code; | |
932 | const char *format_ptr; | |
933 | ||
934 | code = GET_CODE (orig); | |
935 | ||
936 | /* For the context of dse, if we end up expand into a huge tree, we | |
937 | will not have a useful address, so we might as well just give up | |
938 | quickly. */ | |
939 | if (max_depth <= 0) | |
940 | return NULL; | |
941 | ||
942 | switch (code) | |
943 | { | |
944 | case REG: | |
945 | { | |
946 | struct elt_list *l = REG_VALUES (REGNO (orig)); | |
947 | ||
948 | if (l && l->elt == NULL) | |
949 | l = l->next; | |
950 | for (; l; l = l->next) | |
951 | if (GET_MODE (l->elt->val_rtx) == GET_MODE (orig)) | |
952 | { | |
953 | rtx result; | |
954 | int regno = REGNO (orig); | |
955 | ||
956 | /* The only thing that we are not willing to do (this | |
6ed3da00 | 957 | is requirement of dse and if others potential uses |
6fb5fa3c DB |
958 | need this function we should add a parm to control |
959 | it) is that we will not substitute the | |
960 | STACK_POINTER_REGNUM, FRAME_POINTER or the | |
961 | HARD_FRAME_POINTER. | |
962 | ||
cea618ac | 963 | These expansions confuses the code that notices that |
6fb5fa3c DB |
964 | stores into the frame go dead at the end of the |
965 | function and that the frame is not effected by calls | |
966 | to subroutines. If you allow the | |
967 | STACK_POINTER_REGNUM substitution, then dse will | |
968 | think that parameter pushing also goes dead which is | |
969 | wrong. If you allow the FRAME_POINTER or the | |
970 | HARD_FRAME_POINTER then you lose the opportunity to | |
971 | make the frame assumptions. */ | |
972 | if (regno == STACK_POINTER_REGNUM | |
973 | || regno == FRAME_POINTER_REGNUM | |
974 | || regno == HARD_FRAME_POINTER_REGNUM) | |
975 | return orig; | |
976 | ||
977 | bitmap_set_bit (regs_active, regno); | |
978 | ||
979 | if (dump_file) | |
980 | fprintf (dump_file, "expanding: r%d into: ", regno); | |
981 | ||
982 | result = expand_loc (l->elt->locs, regs_active, max_depth); | |
983 | bitmap_clear_bit (regs_active, regno); | |
984 | ||
985 | if (result) | |
986 | return result; | |
987 | else | |
988 | return orig; | |
989 | } | |
990 | } | |
991 | ||
992 | case CONST_INT: | |
993 | case CONST_DOUBLE: | |
994 | case CONST_VECTOR: | |
995 | case SYMBOL_REF: | |
996 | case CODE_LABEL: | |
997 | case PC: | |
998 | case CC0: | |
999 | case SCRATCH: | |
1000 | /* SCRATCH must be shared because they represent distinct values. */ | |
1001 | return orig; | |
1002 | case CLOBBER: | |
1003 | if (REG_P (XEXP (orig, 0)) && HARD_REGISTER_NUM_P (REGNO (XEXP (orig, 0)))) | |
1004 | return orig; | |
1005 | break; | |
1006 | ||
1007 | case CONST: | |
1008 | if (shared_const_p (orig)) | |
1009 | return orig; | |
1010 | break; | |
1011 | ||
1012 | ||
1013 | case VALUE: | |
1014 | { | |
1015 | rtx result; | |
1016 | if (dump_file) | |
1017 | fprintf (dump_file, "expanding value %s into: ", GET_MODE_NAME (GET_MODE (orig))); | |
1018 | ||
1019 | result = expand_loc (CSELIB_VAL_PTR (orig)->locs, regs_active, max_depth); | |
1020 | if (result | |
1021 | && GET_CODE (result) == CONST_INT | |
1022 | && GET_MODE (orig) != VOIDmode) | |
1023 | { | |
1024 | result = gen_rtx_CONST (GET_MODE (orig), result); | |
1025 | if (dump_file) | |
1026 | fprintf (dump_file, " wrapping const_int result in const to preserve mode %s\n", | |
1027 | GET_MODE_NAME (GET_MODE (orig))); | |
1028 | } | |
1029 | return result; | |
1030 | } | |
1031 | default: | |
1032 | break; | |
1033 | } | |
1034 | ||
1035 | /* Copy the various flags, fields, and other information. We assume | |
1036 | that all fields need copying, and then clear the fields that should | |
1037 | not be copied. That is the sensible default behavior, and forces | |
1038 | us to explicitly document why we are *not* copying a flag. */ | |
1039 | copy = shallow_copy_rtx (orig); | |
1040 | ||
1041 | format_ptr = GET_RTX_FORMAT (GET_CODE (copy)); | |
1042 | ||
1043 | for (i = 0; i < GET_RTX_LENGTH (GET_CODE (copy)); i++) | |
1044 | switch (*format_ptr++) | |
1045 | { | |
1046 | case 'e': | |
1047 | if (XEXP (orig, i) != NULL) | |
1048 | { | |
1049 | rtx result = cselib_expand_value_rtx (XEXP (orig, i), regs_active, max_depth - 1); | |
1050 | if (!result) | |
1051 | return NULL; | |
1052 | XEXP (copy, i) = result; | |
1053 | } | |
1054 | break; | |
1055 | ||
1056 | case 'E': | |
1057 | case 'V': | |
1058 | if (XVEC (orig, i) != NULL) | |
1059 | { | |
1060 | XVEC (copy, i) = rtvec_alloc (XVECLEN (orig, i)); | |
1061 | for (j = 0; j < XVECLEN (copy, i); j++) | |
1062 | { | |
1063 | rtx result = cselib_expand_value_rtx (XVECEXP (orig, i, j), regs_active, max_depth - 1); | |
1064 | if (!result) | |
1065 | return NULL; | |
1066 | XVECEXP (copy, i, j) = result; | |
1067 | } | |
1068 | } | |
1069 | break; | |
1070 | ||
1071 | case 't': | |
1072 | case 'w': | |
1073 | case 'i': | |
1074 | case 's': | |
1075 | case 'S': | |
1076 | case 'T': | |
1077 | case 'u': | |
1078 | case 'B': | |
1079 | case '0': | |
1080 | /* These are left unchanged. */ | |
1081 | break; | |
1082 | ||
1083 | default: | |
1084 | gcc_unreachable (); | |
1085 | } | |
1086 | ||
1087 | scopy = simplify_rtx (copy); | |
1088 | if (scopy) | |
1089 | return scopy; | |
1090 | return copy; | |
1091 | } | |
1092 | ||
fa49fd0f RK |
1093 | /* Walk rtx X and replace all occurrences of REG and MEM subexpressions |
1094 | with VALUE expressions. This way, it becomes independent of changes | |
1095 | to registers and memory. | |
1096 | X isn't actually modified; if modifications are needed, new rtl is | |
1097 | allocated. However, the return value can share rtl with X. */ | |
1098 | ||
91700444 | 1099 | rtx |
7080f735 | 1100 | cselib_subst_to_values (rtx x) |
fa49fd0f RK |
1101 | { |
1102 | enum rtx_code code = GET_CODE (x); | |
1103 | const char *fmt = GET_RTX_FORMAT (code); | |
1104 | cselib_val *e; | |
1105 | struct elt_list *l; | |
1106 | rtx copy = x; | |
1107 | int i; | |
1108 | ||
1109 | switch (code) | |
1110 | { | |
1111 | case REG: | |
60fa6660 AO |
1112 | l = REG_VALUES (REGNO (x)); |
1113 | if (l && l->elt == NULL) | |
1114 | l = l->next; | |
1115 | for (; l; l = l->next) | |
757bbef8 SB |
1116 | if (GET_MODE (l->elt->val_rtx) == GET_MODE (x)) |
1117 | return l->elt->val_rtx; | |
fa49fd0f | 1118 | |
341c100f | 1119 | gcc_unreachable (); |
fa49fd0f RK |
1120 | |
1121 | case MEM: | |
1122 | e = cselib_lookup_mem (x, 0); | |
1123 | if (! e) | |
91700444 BS |
1124 | { |
1125 | /* This happens for autoincrements. Assign a value that doesn't | |
1126 | match any other. */ | |
1127 | e = new_cselib_val (++next_unknown_value, GET_MODE (x)); | |
1128 | } | |
757bbef8 | 1129 | return e->val_rtx; |
fa49fd0f | 1130 | |
fa49fd0f | 1131 | case CONST_DOUBLE: |
69ef87e2 | 1132 | case CONST_VECTOR: |
fa49fd0f | 1133 | case CONST_INT: |
091a3ac7 | 1134 | case CONST_FIXED: |
fa49fd0f RK |
1135 | return x; |
1136 | ||
91700444 BS |
1137 | case POST_INC: |
1138 | case PRE_INC: | |
1139 | case POST_DEC: | |
1140 | case PRE_DEC: | |
1141 | case POST_MODIFY: | |
1142 | case PRE_MODIFY: | |
1143 | e = new_cselib_val (++next_unknown_value, GET_MODE (x)); | |
757bbef8 | 1144 | return e->val_rtx; |
7080f735 | 1145 | |
fa49fd0f RK |
1146 | default: |
1147 | break; | |
1148 | } | |
1149 | ||
1150 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
1151 | { | |
1152 | if (fmt[i] == 'e') | |
1153 | { | |
1154 | rtx t = cselib_subst_to_values (XEXP (x, i)); | |
1155 | ||
1156 | if (t != XEXP (x, i) && x == copy) | |
1157 | copy = shallow_copy_rtx (x); | |
1158 | ||
1159 | XEXP (copy, i) = t; | |
1160 | } | |
1161 | else if (fmt[i] == 'E') | |
1162 | { | |
1163 | int j, k; | |
1164 | ||
1165 | for (j = 0; j < XVECLEN (x, i); j++) | |
1166 | { | |
1167 | rtx t = cselib_subst_to_values (XVECEXP (x, i, j)); | |
1168 | ||
1169 | if (t != XVECEXP (x, i, j) && XVEC (x, i) == XVEC (copy, i)) | |
1170 | { | |
1171 | if (x == copy) | |
1172 | copy = shallow_copy_rtx (x); | |
1173 | ||
1174 | XVEC (copy, i) = rtvec_alloc (XVECLEN (x, i)); | |
1175 | for (k = 0; k < j; k++) | |
1176 | XVECEXP (copy, i, k) = XVECEXP (x, i, k); | |
1177 | } | |
1178 | ||
1179 | XVECEXP (copy, i, j) = t; | |
1180 | } | |
1181 | } | |
1182 | } | |
1183 | ||
1184 | return copy; | |
1185 | } | |
1186 | ||
1187 | /* Look up the rtl expression X in our tables and return the value it has. | |
1188 | If CREATE is zero, we return NULL if we don't know the value. Otherwise, | |
1189 | we create a new one if possible, using mode MODE if X doesn't have a mode | |
1190 | (i.e. because it's a constant). */ | |
1191 | ||
1192 | cselib_val * | |
7080f735 | 1193 | cselib_lookup (rtx x, enum machine_mode mode, int create) |
fa49fd0f RK |
1194 | { |
1195 | void **slot; | |
1196 | cselib_val *e; | |
1197 | unsigned int hashval; | |
1198 | ||
1199 | if (GET_MODE (x) != VOIDmode) | |
1200 | mode = GET_MODE (x); | |
1201 | ||
1202 | if (GET_CODE (x) == VALUE) | |
1203 | return CSELIB_VAL_PTR (x); | |
1204 | ||
f8cfc6aa | 1205 | if (REG_P (x)) |
fa49fd0f RK |
1206 | { |
1207 | struct elt_list *l; | |
1208 | unsigned int i = REGNO (x); | |
1209 | ||
60fa6660 AO |
1210 | l = REG_VALUES (i); |
1211 | if (l && l->elt == NULL) | |
1212 | l = l->next; | |
1213 | for (; l; l = l->next) | |
757bbef8 | 1214 | if (mode == GET_MODE (l->elt->val_rtx)) |
fa49fd0f RK |
1215 | return l->elt; |
1216 | ||
1217 | if (! create) | |
1218 | return 0; | |
1219 | ||
31825e57 DM |
1220 | if (i < FIRST_PSEUDO_REGISTER) |
1221 | { | |
66fd46b6 | 1222 | unsigned int n = hard_regno_nregs[i][mode]; |
31825e57 DM |
1223 | |
1224 | if (n > max_value_regs) | |
1225 | max_value_regs = n; | |
1226 | } | |
1227 | ||
fa49fd0f RK |
1228 | e = new_cselib_val (++next_unknown_value, GET_MODE (x)); |
1229 | e->locs = new_elt_loc_list (e->locs, x); | |
1230 | if (REG_VALUES (i) == 0) | |
60fa6660 AO |
1231 | { |
1232 | /* Maintain the invariant that the first entry of | |
1233 | REG_VALUES, if present, must be the value used to set the | |
1234 | register, or NULL. */ | |
6790d1ab | 1235 | used_regs[n_used_regs++] = i; |
60fa6660 AO |
1236 | REG_VALUES (i) = new_elt_list (REG_VALUES (i), NULL); |
1237 | } | |
1238 | REG_VALUES (i)->next = new_elt_list (REG_VALUES (i)->next, e); | |
7c514720 | 1239 | slot = htab_find_slot_with_hash (cselib_hash_table, x, e->value, INSERT); |
fa49fd0f RK |
1240 | *slot = e; |
1241 | return e; | |
1242 | } | |
1243 | ||
3c0cb5de | 1244 | if (MEM_P (x)) |
fa49fd0f RK |
1245 | return cselib_lookup_mem (x, create); |
1246 | ||
29c1846b | 1247 | hashval = cselib_hash_rtx (x, create); |
fa49fd0f RK |
1248 | /* Can't even create if hashing is not possible. */ |
1249 | if (! hashval) | |
1250 | return 0; | |
1251 | ||
7c514720 | 1252 | slot = htab_find_slot_with_hash (cselib_hash_table, wrap_constant (mode, x), |
fa49fd0f RK |
1253 | hashval, create ? INSERT : NO_INSERT); |
1254 | if (slot == 0) | |
1255 | return 0; | |
1256 | ||
1257 | e = (cselib_val *) *slot; | |
1258 | if (e) | |
1259 | return e; | |
1260 | ||
1261 | e = new_cselib_val (hashval, mode); | |
1262 | ||
1263 | /* We have to fill the slot before calling cselib_subst_to_values: | |
1264 | the hash table is inconsistent until we do so, and | |
1265 | cselib_subst_to_values will need to do lookups. */ | |
1266 | *slot = (void *) e; | |
1267 | e->locs = new_elt_loc_list (e->locs, cselib_subst_to_values (x)); | |
1268 | return e; | |
1269 | } | |
1270 | ||
1271 | /* Invalidate any entries in reg_values that overlap REGNO. This is called | |
1272 | if REGNO is changing. MODE is the mode of the assignment to REGNO, which | |
1273 | is used to determine how many hard registers are being changed. If MODE | |
1274 | is VOIDmode, then only REGNO is being changed; this is used when | |
1275 | invalidating call clobbered registers across a call. */ | |
1276 | ||
1277 | static void | |
7080f735 | 1278 | cselib_invalidate_regno (unsigned int regno, enum machine_mode mode) |
fa49fd0f RK |
1279 | { |
1280 | unsigned int endregno; | |
1281 | unsigned int i; | |
1282 | ||
1283 | /* If we see pseudos after reload, something is _wrong_. */ | |
341c100f NS |
1284 | gcc_assert (!reload_completed || regno < FIRST_PSEUDO_REGISTER |
1285 | || reg_renumber[regno] < 0); | |
fa49fd0f RK |
1286 | |
1287 | /* Determine the range of registers that must be invalidated. For | |
1288 | pseudos, only REGNO is affected. For hard regs, we must take MODE | |
1289 | into account, and we must also invalidate lower register numbers | |
1290 | if they contain values that overlap REGNO. */ | |
291aac59 | 1291 | if (regno < FIRST_PSEUDO_REGISTER) |
31825e57 | 1292 | { |
341c100f | 1293 | gcc_assert (mode != VOIDmode); |
7080f735 | 1294 | |
31825e57 DM |
1295 | if (regno < max_value_regs) |
1296 | i = 0; | |
1297 | else | |
1298 | i = regno - max_value_regs; | |
fa49fd0f | 1299 | |
09e18274 | 1300 | endregno = end_hard_regno (mode, regno); |
31825e57 DM |
1301 | } |
1302 | else | |
1303 | { | |
1304 | i = regno; | |
1305 | endregno = regno + 1; | |
1306 | } | |
1307 | ||
1308 | for (; i < endregno; i++) | |
fa49fd0f RK |
1309 | { |
1310 | struct elt_list **l = ®_VALUES (i); | |
1311 | ||
1312 | /* Go through all known values for this reg; if it overlaps the range | |
1313 | we're invalidating, remove the value. */ | |
1314 | while (*l) | |
1315 | { | |
1316 | cselib_val *v = (*l)->elt; | |
1317 | struct elt_loc_list **p; | |
1318 | unsigned int this_last = i; | |
1319 | ||
60fa6660 | 1320 | if (i < FIRST_PSEUDO_REGISTER && v != NULL) |
09e18274 | 1321 | this_last = end_hard_regno (GET_MODE (v->val_rtx), i) - 1; |
fa49fd0f | 1322 | |
60fa6660 | 1323 | if (this_last < regno || v == NULL) |
fa49fd0f RK |
1324 | { |
1325 | l = &(*l)->next; | |
1326 | continue; | |
1327 | } | |
1328 | ||
1329 | /* We have an overlap. */ | |
60fa6660 AO |
1330 | if (*l == REG_VALUES (i)) |
1331 | { | |
1332 | /* Maintain the invariant that the first entry of | |
1333 | REG_VALUES, if present, must be the value used to set | |
1334 | the register, or NULL. This is also nice because | |
1335 | then we won't push the same regno onto user_regs | |
1336 | multiple times. */ | |
1337 | (*l)->elt = NULL; | |
1338 | l = &(*l)->next; | |
1339 | } | |
1340 | else | |
1341 | unchain_one_elt_list (l); | |
fa49fd0f RK |
1342 | |
1343 | /* Now, we clear the mapping from value to reg. It must exist, so | |
1344 | this code will crash intentionally if it doesn't. */ | |
1345 | for (p = &v->locs; ; p = &(*p)->next) | |
1346 | { | |
1347 | rtx x = (*p)->loc; | |
1348 | ||
f8cfc6aa | 1349 | if (REG_P (x) && REGNO (x) == i) |
fa49fd0f RK |
1350 | { |
1351 | unchain_one_elt_loc_list (p); | |
1352 | break; | |
1353 | } | |
1354 | } | |
1355 | if (v->locs == 0) | |
1356 | n_useless_values++; | |
1357 | } | |
1358 | } | |
1359 | } | |
9ddb66ca JH |
1360 | \f |
1361 | /* Return 1 if X has a value that can vary even between two | |
1362 | executions of the program. 0 means X can be compared reliably | |
1363 | against certain constants or near-constants. */ | |
fa49fd0f | 1364 | |
4f588890 KG |
1365 | static bool |
1366 | cselib_rtx_varies_p (const_rtx x ATTRIBUTE_UNUSED, bool from_alias ATTRIBUTE_UNUSED) | |
fa49fd0f | 1367 | { |
9ddb66ca JH |
1368 | /* We actually don't need to verify very hard. This is because |
1369 | if X has actually changed, we invalidate the memory anyway, | |
1370 | so assume that all common memory addresses are | |
1371 | invariant. */ | |
fa49fd0f RK |
1372 | return 0; |
1373 | } | |
1374 | ||
7101fb18 JH |
1375 | /* Invalidate any locations in the table which are changed because of a |
1376 | store to MEM_RTX. If this is called because of a non-const call | |
1377 | instruction, MEM_RTX is (mem:BLK const0_rtx). */ | |
fa49fd0f | 1378 | |
7101fb18 | 1379 | static void |
7080f735 | 1380 | cselib_invalidate_mem (rtx mem_rtx) |
fa49fd0f | 1381 | { |
7101fb18 | 1382 | cselib_val **vp, *v, *next; |
c65ecebc | 1383 | int num_mems = 0; |
9ddb66ca JH |
1384 | rtx mem_addr; |
1385 | ||
1386 | mem_addr = canon_rtx (get_addr (XEXP (mem_rtx, 0))); | |
1387 | mem_rtx = canon_rtx (mem_rtx); | |
fa49fd0f | 1388 | |
7101fb18 JH |
1389 | vp = &first_containing_mem; |
1390 | for (v = *vp; v != &dummy_val; v = next) | |
fa49fd0f | 1391 | { |
7101fb18 JH |
1392 | bool has_mem = false; |
1393 | struct elt_loc_list **p = &v->locs; | |
1394 | int had_locs = v->locs != 0; | |
fa49fd0f | 1395 | |
7101fb18 | 1396 | while (*p) |
fa49fd0f | 1397 | { |
7101fb18 JH |
1398 | rtx x = (*p)->loc; |
1399 | cselib_val *addr; | |
1400 | struct elt_list **mem_chain; | |
1401 | ||
1402 | /* MEMs may occur in locations only at the top level; below | |
1403 | that every MEM or REG is substituted by its VALUE. */ | |
3c0cb5de | 1404 | if (!MEM_P (x)) |
fa49fd0f | 1405 | { |
7101fb18 JH |
1406 | p = &(*p)->next; |
1407 | continue; | |
1408 | } | |
c65ecebc | 1409 | if (num_mems < PARAM_VALUE (PARAM_MAX_CSELIB_MEMORY_LOCATIONS) |
9ddb66ca JH |
1410 | && ! canon_true_dependence (mem_rtx, GET_MODE (mem_rtx), mem_addr, |
1411 | x, cselib_rtx_varies_p)) | |
7101fb18 JH |
1412 | { |
1413 | has_mem = true; | |
c65ecebc | 1414 | num_mems++; |
7101fb18 JH |
1415 | p = &(*p)->next; |
1416 | continue; | |
fa49fd0f RK |
1417 | } |
1418 | ||
7101fb18 JH |
1419 | /* This one overlaps. */ |
1420 | /* We must have a mapping from this MEM's address to the | |
1421 | value (E). Remove that, too. */ | |
1422 | addr = cselib_lookup (XEXP (x, 0), VOIDmode, 0); | |
1423 | mem_chain = &addr->addr_list; | |
1424 | for (;;) | |
1425 | { | |
1426 | if ((*mem_chain)->elt == v) | |
1427 | { | |
1428 | unchain_one_elt_list (mem_chain); | |
1429 | break; | |
1430 | } | |
fa49fd0f | 1431 | |
7101fb18 JH |
1432 | mem_chain = &(*mem_chain)->next; |
1433 | } | |
fa49fd0f | 1434 | |
7101fb18 JH |
1435 | unchain_one_elt_loc_list (p); |
1436 | } | |
fa49fd0f | 1437 | |
7101fb18 JH |
1438 | if (had_locs && v->locs == 0) |
1439 | n_useless_values++; | |
fa49fd0f | 1440 | |
7101fb18 JH |
1441 | next = v->next_containing_mem; |
1442 | if (has_mem) | |
1443 | { | |
1444 | *vp = v; | |
1445 | vp = &(*vp)->next_containing_mem; | |
1446 | } | |
1447 | else | |
1448 | v->next_containing_mem = NULL; | |
1449 | } | |
1450 | *vp = &dummy_val; | |
fa49fd0f RK |
1451 | } |
1452 | ||
0d87c765 | 1453 | /* Invalidate DEST, which is being assigned to or clobbered. */ |
fa49fd0f | 1454 | |
0d87c765 RH |
1455 | void |
1456 | cselib_invalidate_rtx (rtx dest) | |
fa49fd0f | 1457 | { |
46d096a3 SB |
1458 | while (GET_CODE (dest) == SUBREG |
1459 | || GET_CODE (dest) == ZERO_EXTRACT | |
1460 | || GET_CODE (dest) == STRICT_LOW_PART) | |
fa49fd0f RK |
1461 | dest = XEXP (dest, 0); |
1462 | ||
f8cfc6aa | 1463 | if (REG_P (dest)) |
fa49fd0f | 1464 | cselib_invalidate_regno (REGNO (dest), GET_MODE (dest)); |
3c0cb5de | 1465 | else if (MEM_P (dest)) |
fa49fd0f RK |
1466 | cselib_invalidate_mem (dest); |
1467 | ||
1468 | /* Some machines don't define AUTO_INC_DEC, but they still use push | |
1469 | instructions. We need to catch that case here in order to | |
1470 | invalidate the stack pointer correctly. Note that invalidating | |
1471 | the stack pointer is different from invalidating DEST. */ | |
1472 | if (push_operand (dest, GET_MODE (dest))) | |
0d87c765 RH |
1473 | cselib_invalidate_rtx (stack_pointer_rtx); |
1474 | } | |
1475 | ||
1476 | /* A wrapper for cselib_invalidate_rtx to be called via note_stores. */ | |
1477 | ||
1478 | static void | |
7bc980e1 | 1479 | cselib_invalidate_rtx_note_stores (rtx dest, const_rtx ignore ATTRIBUTE_UNUSED, |
0d87c765 RH |
1480 | void *data ATTRIBUTE_UNUSED) |
1481 | { | |
1482 | cselib_invalidate_rtx (dest); | |
fa49fd0f RK |
1483 | } |
1484 | ||
1485 | /* Record the result of a SET instruction. DEST is being set; the source | |
1486 | contains the value described by SRC_ELT. If DEST is a MEM, DEST_ADDR_ELT | |
1487 | describes its address. */ | |
1488 | ||
1489 | static void | |
7080f735 | 1490 | cselib_record_set (rtx dest, cselib_val *src_elt, cselib_val *dest_addr_elt) |
fa49fd0f | 1491 | { |
f8cfc6aa | 1492 | int dreg = REG_P (dest) ? (int) REGNO (dest) : -1; |
fa49fd0f RK |
1493 | |
1494 | if (src_elt == 0 || side_effects_p (dest)) | |
1495 | return; | |
1496 | ||
1497 | if (dreg >= 0) | |
1498 | { | |
31825e57 DM |
1499 | if (dreg < FIRST_PSEUDO_REGISTER) |
1500 | { | |
66fd46b6 | 1501 | unsigned int n = hard_regno_nregs[dreg][GET_MODE (dest)]; |
31825e57 DM |
1502 | |
1503 | if (n > max_value_regs) | |
1504 | max_value_regs = n; | |
1505 | } | |
1506 | ||
60fa6660 AO |
1507 | if (REG_VALUES (dreg) == 0) |
1508 | { | |
6790d1ab | 1509 | used_regs[n_used_regs++] = dreg; |
60fa6660 AO |
1510 | REG_VALUES (dreg) = new_elt_list (REG_VALUES (dreg), src_elt); |
1511 | } | |
1512 | else | |
1513 | { | |
341c100f NS |
1514 | /* The register should have been invalidated. */ |
1515 | gcc_assert (REG_VALUES (dreg)->elt == 0); | |
1516 | REG_VALUES (dreg)->elt = src_elt; | |
60fa6660 AO |
1517 | } |
1518 | ||
fa49fd0f RK |
1519 | if (src_elt->locs == 0) |
1520 | n_useless_values--; | |
1521 | src_elt->locs = new_elt_loc_list (src_elt->locs, dest); | |
1522 | } | |
3c0cb5de | 1523 | else if (MEM_P (dest) && dest_addr_elt != 0 |
463301c3 | 1524 | && cselib_record_memory) |
fa49fd0f RK |
1525 | { |
1526 | if (src_elt->locs == 0) | |
1527 | n_useless_values--; | |
1528 | add_mem_for_addr (dest_addr_elt, src_elt, dest); | |
1529 | } | |
1530 | } | |
1531 | ||
1532 | /* Describe a single set that is part of an insn. */ | |
1533 | struct set | |
1534 | { | |
1535 | rtx src; | |
1536 | rtx dest; | |
1537 | cselib_val *src_elt; | |
1538 | cselib_val *dest_addr_elt; | |
1539 | }; | |
1540 | ||
1541 | /* There is no good way to determine how many elements there can be | |
1542 | in a PARALLEL. Since it's fairly cheap, use a really large number. */ | |
1543 | #define MAX_SETS (FIRST_PSEUDO_REGISTER * 2) | |
1544 | ||
1545 | /* Record the effects of any sets in INSN. */ | |
1546 | static void | |
7080f735 | 1547 | cselib_record_sets (rtx insn) |
fa49fd0f RK |
1548 | { |
1549 | int n_sets = 0; | |
1550 | int i; | |
1551 | struct set sets[MAX_SETS]; | |
1552 | rtx body = PATTERN (insn); | |
b7933c21 | 1553 | rtx cond = 0; |
fa49fd0f RK |
1554 | |
1555 | body = PATTERN (insn); | |
b7933c21 BS |
1556 | if (GET_CODE (body) == COND_EXEC) |
1557 | { | |
1558 | cond = COND_EXEC_TEST (body); | |
1559 | body = COND_EXEC_CODE (body); | |
1560 | } | |
1561 | ||
fa49fd0f RK |
1562 | /* Find all sets. */ |
1563 | if (GET_CODE (body) == SET) | |
1564 | { | |
1565 | sets[0].src = SET_SRC (body); | |
1566 | sets[0].dest = SET_DEST (body); | |
1567 | n_sets = 1; | |
1568 | } | |
1569 | else if (GET_CODE (body) == PARALLEL) | |
1570 | { | |
1571 | /* Look through the PARALLEL and record the values being | |
1572 | set, if possible. Also handle any CLOBBERs. */ | |
1573 | for (i = XVECLEN (body, 0) - 1; i >= 0; --i) | |
1574 | { | |
1575 | rtx x = XVECEXP (body, 0, i); | |
1576 | ||
1577 | if (GET_CODE (x) == SET) | |
1578 | { | |
1579 | sets[n_sets].src = SET_SRC (x); | |
1580 | sets[n_sets].dest = SET_DEST (x); | |
1581 | n_sets++; | |
1582 | } | |
1583 | } | |
1584 | } | |
1585 | ||
1586 | /* Look up the values that are read. Do this before invalidating the | |
1587 | locations that are written. */ | |
1588 | for (i = 0; i < n_sets; i++) | |
1589 | { | |
1590 | rtx dest = sets[i].dest; | |
1591 | ||
1592 | /* A STRICT_LOW_PART can be ignored; we'll record the equivalence for | |
1593 | the low part after invalidating any knowledge about larger modes. */ | |
1594 | if (GET_CODE (sets[i].dest) == STRICT_LOW_PART) | |
1595 | sets[i].dest = dest = XEXP (dest, 0); | |
1596 | ||
1597 | /* We don't know how to record anything but REG or MEM. */ | |
f8cfc6aa | 1598 | if (REG_P (dest) |
3c0cb5de | 1599 | || (MEM_P (dest) && cselib_record_memory)) |
fa49fd0f | 1600 | { |
b7933c21 BS |
1601 | rtx src = sets[i].src; |
1602 | if (cond) | |
1603 | src = gen_rtx_IF_THEN_ELSE (GET_MODE (src), cond, src, dest); | |
37060e78 | 1604 | sets[i].src_elt = cselib_lookup (src, GET_MODE (dest), 1); |
3c0cb5de | 1605 | if (MEM_P (dest)) |
fa49fd0f RK |
1606 | sets[i].dest_addr_elt = cselib_lookup (XEXP (dest, 0), Pmode, 1); |
1607 | else | |
1608 | sets[i].dest_addr_elt = 0; | |
1609 | } | |
1610 | } | |
1611 | ||
1612 | /* Invalidate all locations written by this insn. Note that the elts we | |
1613 | looked up in the previous loop aren't affected, just some of their | |
1614 | locations may go away. */ | |
0d87c765 | 1615 | note_stores (body, cselib_invalidate_rtx_note_stores, NULL); |
fa49fd0f | 1616 | |
b7048ab7 RH |
1617 | /* If this is an asm, look for duplicate sets. This can happen when the |
1618 | user uses the same value as an output multiple times. This is valid | |
1619 | if the outputs are not actually used thereafter. Treat this case as | |
1620 | if the value isn't actually set. We do this by smashing the destination | |
1621 | to pc_rtx, so that we won't record the value later. */ | |
1622 | if (n_sets >= 2 && asm_noperands (body) >= 0) | |
1623 | { | |
1624 | for (i = 0; i < n_sets; i++) | |
1625 | { | |
1626 | rtx dest = sets[i].dest; | |
3c0cb5de | 1627 | if (REG_P (dest) || MEM_P (dest)) |
b7048ab7 RH |
1628 | { |
1629 | int j; | |
1630 | for (j = i + 1; j < n_sets; j++) | |
1631 | if (rtx_equal_p (dest, sets[j].dest)) | |
1632 | { | |
1633 | sets[i].dest = pc_rtx; | |
1634 | sets[j].dest = pc_rtx; | |
1635 | } | |
1636 | } | |
1637 | } | |
1638 | } | |
1639 | ||
fa49fd0f RK |
1640 | /* Now enter the equivalences in our tables. */ |
1641 | for (i = 0; i < n_sets; i++) | |
1642 | { | |
1643 | rtx dest = sets[i].dest; | |
f8cfc6aa | 1644 | if (REG_P (dest) |
3c0cb5de | 1645 | || (MEM_P (dest) && cselib_record_memory)) |
fa49fd0f RK |
1646 | cselib_record_set (dest, sets[i].src_elt, sets[i].dest_addr_elt); |
1647 | } | |
1648 | } | |
1649 | ||
1650 | /* Record the effects of INSN. */ | |
1651 | ||
1652 | void | |
7080f735 | 1653 | cselib_process_insn (rtx insn) |
fa49fd0f RK |
1654 | { |
1655 | int i; | |
1656 | rtx x; | |
1657 | ||
9635cfad JH |
1658 | if (find_reg_note (insn, REG_LIBCALL, NULL)) |
1659 | cselib_current_insn_in_libcall = true; | |
fa49fd0f RK |
1660 | cselib_current_insn = insn; |
1661 | ||
1662 | /* Forget everything at a CODE_LABEL, a volatile asm, or a setjmp. */ | |
4b4bf941 JQ |
1663 | if (LABEL_P (insn) |
1664 | || (CALL_P (insn) | |
570a98eb | 1665 | && find_reg_note (insn, REG_SETJMP, NULL)) |
4b4bf941 | 1666 | || (NONJUMP_INSN_P (insn) |
fa49fd0f RK |
1667 | && GET_CODE (PATTERN (insn)) == ASM_OPERANDS |
1668 | && MEM_VOLATILE_P (PATTERN (insn)))) | |
1669 | { | |
5976e643 RS |
1670 | if (find_reg_note (insn, REG_RETVAL, NULL)) |
1671 | cselib_current_insn_in_libcall = false; | |
eb232f4e | 1672 | cselib_clear_table (); |
fa49fd0f RK |
1673 | return; |
1674 | } | |
1675 | ||
1676 | if (! INSN_P (insn)) | |
1677 | { | |
5976e643 RS |
1678 | if (find_reg_note (insn, REG_RETVAL, NULL)) |
1679 | cselib_current_insn_in_libcall = false; | |
fa49fd0f RK |
1680 | cselib_current_insn = 0; |
1681 | return; | |
1682 | } | |
1683 | ||
1684 | /* If this is a call instruction, forget anything stored in a | |
1685 | call clobbered register, or, if this is not a const call, in | |
1686 | memory. */ | |
4b4bf941 | 1687 | if (CALL_P (insn)) |
fa49fd0f RK |
1688 | { |
1689 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
7e42db17 DJ |
1690 | if (call_used_regs[i] |
1691 | || (REG_VALUES (i) && REG_VALUES (i)->elt | |
1692 | && HARD_REGNO_CALL_PART_CLOBBERED (i, | |
757bbef8 | 1693 | GET_MODE (REG_VALUES (i)->elt->val_rtx)))) |
291aac59 | 1694 | cselib_invalidate_regno (i, reg_raw_mode[i]); |
fa49fd0f | 1695 | |
24a28584 | 1696 | if (! CONST_OR_PURE_CALL_P (insn)) |
fa49fd0f RK |
1697 | cselib_invalidate_mem (callmem); |
1698 | } | |
1699 | ||
1700 | cselib_record_sets (insn); | |
1701 | ||
1702 | #ifdef AUTO_INC_DEC | |
1703 | /* Clobber any registers which appear in REG_INC notes. We | |
1704 | could keep track of the changes to their values, but it is | |
1705 | unlikely to help. */ | |
1706 | for (x = REG_NOTES (insn); x; x = XEXP (x, 1)) | |
1707 | if (REG_NOTE_KIND (x) == REG_INC) | |
0d87c765 | 1708 | cselib_invalidate_rtx (XEXP (x, 0)); |
fa49fd0f RK |
1709 | #endif |
1710 | ||
1711 | /* Look for any CLOBBERs in CALL_INSN_FUNCTION_USAGE, but only | |
1712 | after we have processed the insn. */ | |
4b4bf941 | 1713 | if (CALL_P (insn)) |
fa49fd0f RK |
1714 | for (x = CALL_INSN_FUNCTION_USAGE (insn); x; x = XEXP (x, 1)) |
1715 | if (GET_CODE (XEXP (x, 0)) == CLOBBER) | |
0d87c765 | 1716 | cselib_invalidate_rtx (XEXP (XEXP (x, 0), 0)); |
fa49fd0f | 1717 | |
5976e643 RS |
1718 | if (find_reg_note (insn, REG_RETVAL, NULL)) |
1719 | cselib_current_insn_in_libcall = false; | |
fa49fd0f RK |
1720 | cselib_current_insn = 0; |
1721 | ||
96d0cc81 JH |
1722 | if (n_useless_values > MAX_USELESS_VALUES |
1723 | /* remove_useless_values is linear in the hash table size. Avoid | |
9f5ed61a | 1724 | quadratic behavior for very large hashtables with very few |
96d0cc81 JH |
1725 | useless elements. */ |
1726 | && (unsigned int)n_useless_values > cselib_hash_table->n_elements / 4) | |
fa49fd0f RK |
1727 | remove_useless_values (); |
1728 | } | |
1729 | ||
fa49fd0f RK |
1730 | /* Initialize cselib for one pass. The caller must also call |
1731 | init_alias_analysis. */ | |
1732 | ||
1733 | void | |
463301c3 | 1734 | cselib_init (bool record_memory) |
fa49fd0f | 1735 | { |
6a59927d JH |
1736 | elt_list_pool = create_alloc_pool ("elt_list", |
1737 | sizeof (struct elt_list), 10); | |
1738 | elt_loc_list_pool = create_alloc_pool ("elt_loc_list", | |
1739 | sizeof (struct elt_loc_list), 10); | |
1740 | cselib_val_pool = create_alloc_pool ("cselib_val_list", | |
1741 | sizeof (cselib_val), 10); | |
aacd3885 | 1742 | value_pool = create_alloc_pool ("value", RTX_CODE_SIZE (VALUE), 100); |
463301c3 | 1743 | cselib_record_memory = record_memory; |
ac3768f6 SB |
1744 | |
1745 | /* (mem:BLK (scratch)) is a special mechanism to conflict with everything, | |
1746 | see canon_true_dependence. This is only created once. */ | |
fa49fd0f | 1747 | if (! callmem) |
ac3768f6 | 1748 | callmem = gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (VOIDmode)); |
fa49fd0f RK |
1749 | |
1750 | cselib_nregs = max_reg_num (); | |
6790d1ab JH |
1751 | |
1752 | /* We preserve reg_values to allow expensive clearing of the whole thing. | |
1753 | Reallocate it however if it happens to be too large. */ | |
1754 | if (!reg_values || reg_values_size < cselib_nregs | |
1755 | || (reg_values_size > 10 && reg_values_size > cselib_nregs * 4)) | |
e2500fed | 1756 | { |
6790d1ab JH |
1757 | if (reg_values) |
1758 | free (reg_values); | |
1759 | /* Some space for newly emit instructions so we don't end up | |
1760 | reallocating in between passes. */ | |
1761 | reg_values_size = cselib_nregs + (63 + cselib_nregs) / 16; | |
5ed6ace5 | 1762 | reg_values = XCNEWVEC (struct elt_list *, reg_values_size); |
e2500fed | 1763 | } |
5ed6ace5 | 1764 | used_regs = XNEWVEC (unsigned int, cselib_nregs); |
6790d1ab | 1765 | n_used_regs = 0; |
7c514720 KH |
1766 | cselib_hash_table = htab_create (31, get_value_hash, |
1767 | entry_and_rtx_equal_p, NULL); | |
9635cfad | 1768 | cselib_current_insn_in_libcall = false; |
fa49fd0f RK |
1769 | } |
1770 | ||
1771 | /* Called when the current user is done with cselib. */ | |
1772 | ||
1773 | void | |
7080f735 | 1774 | cselib_finish (void) |
fa49fd0f | 1775 | { |
6fb5fa3c | 1776 | cselib_discard_hook = NULL; |
6a59927d JH |
1777 | free_alloc_pool (elt_list_pool); |
1778 | free_alloc_pool (elt_loc_list_pool); | |
1779 | free_alloc_pool (cselib_val_pool); | |
23bd7a93 | 1780 | free_alloc_pool (value_pool); |
eb232f4e | 1781 | cselib_clear_table (); |
7c514720 | 1782 | htab_delete (cselib_hash_table); |
0fc0c4c9 | 1783 | free (used_regs); |
e2500fed | 1784 | used_regs = 0; |
7c514720 | 1785 | cselib_hash_table = 0; |
e2500fed GK |
1786 | n_useless_values = 0; |
1787 | next_unknown_value = 0; | |
fa49fd0f | 1788 | } |
e2500fed GK |
1789 | |
1790 | #include "gt-cselib.h" |