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8b57bfeb | 1 | /* String length optimization |
d1e082c2 | 2 | Copyright (C) 2011-2013 Free Software Foundation, Inc. |
8b57bfeb JJ |
3 | Contributed by Jakub Jelinek <jakub@redhat.com> |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 3, or (at your option) | |
10 | any later version. | |
11 | ||
12 | GCC is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GCC; see the file COPYING3. If not see | |
19 | <http://www.gnu.org/licenses/>. */ | |
20 | ||
21 | #include "config.h" | |
22 | #include "system.h" | |
23 | #include "coretypes.h" | |
4d648807 | 24 | #include "tree.h" |
4a8fb1a1 | 25 | #include "hash-table.h" |
442b4905 | 26 | #include "bitmap.h" |
18f429e2 | 27 | #include "gimple.h" |
45b0be94 | 28 | #include "gimplify.h" |
5be5c238 | 29 | #include "gimple-iterator.h" |
18f429e2 | 30 | #include "gimplify-me.h" |
442b4905 AM |
31 | #include "gimple-ssa.h" |
32 | #include "tree-phinodes.h" | |
33 | #include "ssa-iterators.h" | |
34 | #include "tree-ssanames.h" | |
35 | #include "tree-dfa.h" | |
8b57bfeb JJ |
36 | #include "tree-pass.h" |
37 | #include "domwalk.h" | |
38 | #include "alloc-pool.h" | |
39 | #include "tree-ssa-propagate.h" | |
40 | #include "gimple-pretty-print.h" | |
41 | #include "params.h" | |
b3c3685a | 42 | #include "expr.h" |
8b57bfeb JJ |
43 | |
44 | /* A vector indexed by SSA_NAME_VERSION. 0 means unknown, positive value | |
45 | is an index into strinfo vector, negative value stands for | |
46 | string length of a string literal (~strlen). */ | |
9771b263 | 47 | static vec<int> ssa_ver_to_stridx; |
8b57bfeb JJ |
48 | |
49 | /* Number of currently active string indexes plus one. */ | |
50 | static int max_stridx; | |
51 | ||
52 | /* String information record. */ | |
53 | typedef struct strinfo_struct | |
54 | { | |
55 | /* String length of this string. */ | |
56 | tree length; | |
57 | /* Any of the corresponding pointers for querying alias oracle. */ | |
58 | tree ptr; | |
59 | /* Statement for delayed length computation. */ | |
60 | gimple stmt; | |
61 | /* Pointer to '\0' if known, if NULL, it can be computed as | |
62 | ptr + length. */ | |
63 | tree endptr; | |
64 | /* Reference count. Any changes to strinfo entry possibly shared | |
65 | with dominating basic blocks need unshare_strinfo first, except | |
66 | for dont_invalidate which affects only the immediately next | |
67 | maybe_invalidate. */ | |
68 | int refcount; | |
69 | /* Copy of index. get_strinfo (si->idx) should return si; */ | |
70 | int idx; | |
71 | /* These 3 fields are for chaining related string pointers together. | |
72 | E.g. for | |
73 | bl = strlen (b); dl = strlen (d); strcpy (a, b); c = a + bl; | |
74 | strcpy (c, d); e = c + dl; | |
75 | strinfo(a) -> strinfo(c) -> strinfo(e) | |
76 | All have ->first field equal to strinfo(a)->idx and are doubly | |
77 | chained through prev/next fields. The later strinfos are required | |
78 | to point into the same string with zero or more bytes after | |
79 | the previous pointer and all bytes in between the two pointers | |
80 | must be non-zero. Functions like strcpy or memcpy are supposed | |
81 | to adjust all previous strinfo lengths, but not following strinfo | |
82 | lengths (those are uncertain, usually invalidated during | |
83 | maybe_invalidate, except when the alias oracle knows better). | |
84 | Functions like strcat on the other side adjust the whole | |
85 | related strinfo chain. | |
86 | They are updated lazily, so to use the chain the same first fields | |
87 | and si->prev->next == si->idx needs to be verified. */ | |
88 | int first; | |
89 | int next; | |
90 | int prev; | |
91 | /* A flag whether the string is known to be written in the current | |
92 | function. */ | |
93 | bool writable; | |
94 | /* A flag for the next maybe_invalidate that this strinfo shouldn't | |
95 | be invalidated. Always cleared by maybe_invalidate. */ | |
96 | bool dont_invalidate; | |
97 | } *strinfo; | |
8b57bfeb JJ |
98 | |
99 | /* Pool for allocating strinfo_struct entries. */ | |
100 | static alloc_pool strinfo_pool; | |
101 | ||
102 | /* Vector mapping positive string indexes to strinfo, for the | |
103 | current basic block. The first pointer in the vector is special, | |
104 | it is either NULL, meaning the vector isn't shared, or it is | |
105 | a basic block pointer to the owner basic_block if shared. | |
106 | If some other bb wants to modify the vector, the vector needs | |
107 | to be unshared first, and only the owner bb is supposed to free it. */ | |
9771b263 | 108 | static vec<strinfo, va_heap, vl_embed> *stridx_to_strinfo; |
8b57bfeb JJ |
109 | |
110 | /* One OFFSET->IDX mapping. */ | |
111 | struct stridxlist | |
112 | { | |
113 | struct stridxlist *next; | |
114 | HOST_WIDE_INT offset; | |
115 | int idx; | |
116 | }; | |
117 | ||
118 | /* Hash table entry, mapping a DECL to a chain of OFFSET->IDX mappings. */ | |
119 | struct decl_stridxlist_map | |
120 | { | |
121 | struct tree_map_base base; | |
122 | struct stridxlist list; | |
123 | }; | |
124 | ||
4a8fb1a1 LC |
125 | /* stridxlist hashtable helpers. */ |
126 | ||
127 | struct stridxlist_hasher : typed_noop_remove <decl_stridxlist_map> | |
128 | { | |
129 | typedef decl_stridxlist_map value_type; | |
130 | typedef decl_stridxlist_map compare_type; | |
131 | static inline hashval_t hash (const value_type *); | |
132 | static inline bool equal (const value_type *, const compare_type *); | |
133 | }; | |
134 | ||
135 | /* Hash a from tree in a decl_stridxlist_map. */ | |
136 | ||
137 | inline hashval_t | |
138 | stridxlist_hasher::hash (const value_type *item) | |
139 | { | |
140 | return DECL_UID (item->base.from); | |
141 | } | |
142 | ||
143 | inline bool | |
144 | stridxlist_hasher::equal (const value_type *v, const compare_type *c) | |
145 | { | |
146 | return tree_map_base_eq (&v->base, &c->base); | |
147 | } | |
148 | ||
8b57bfeb JJ |
149 | /* Hash table for mapping decls to a chained list of offset -> idx |
150 | mappings. */ | |
4a8fb1a1 | 151 | static hash_table <stridxlist_hasher> decl_to_stridxlist_htab; |
8b57bfeb JJ |
152 | |
153 | /* Obstack for struct stridxlist and struct decl_stridxlist_map. */ | |
154 | static struct obstack stridx_obstack; | |
155 | ||
156 | /* Last memcpy statement if it could be adjusted if the trailing | |
157 | '\0' written is immediately overwritten, or | |
158 | *x = '\0' store that could be removed if it is immediately overwritten. */ | |
159 | struct laststmt_struct | |
160 | { | |
161 | gimple stmt; | |
162 | tree len; | |
163 | int stridx; | |
164 | } laststmt; | |
165 | ||
8b57bfeb JJ |
166 | /* Helper function for get_stridx. */ |
167 | ||
168 | static int | |
169 | get_addr_stridx (tree exp) | |
170 | { | |
171 | HOST_WIDE_INT off; | |
172 | struct decl_stridxlist_map ent, *e; | |
173 | struct stridxlist *list; | |
174 | tree base; | |
175 | ||
4a8fb1a1 | 176 | if (!decl_to_stridxlist_htab.is_created ()) |
8b57bfeb JJ |
177 | return 0; |
178 | ||
179 | base = get_addr_base_and_unit_offset (exp, &off); | |
180 | if (base == NULL || !DECL_P (base)) | |
181 | return 0; | |
182 | ||
183 | ent.base.from = base; | |
4a8fb1a1 | 184 | e = decl_to_stridxlist_htab.find_with_hash (&ent, DECL_UID (base)); |
8b57bfeb JJ |
185 | if (e == NULL) |
186 | return 0; | |
187 | ||
188 | list = &e->list; | |
189 | do | |
190 | { | |
191 | if (list->offset == off) | |
192 | return list->idx; | |
193 | list = list->next; | |
194 | } | |
195 | while (list); | |
196 | return 0; | |
197 | } | |
198 | ||
199 | /* Return string index for EXP. */ | |
200 | ||
201 | static int | |
202 | get_stridx (tree exp) | |
203 | { | |
b3c3685a | 204 | tree s, o; |
8b57bfeb JJ |
205 | |
206 | if (TREE_CODE (exp) == SSA_NAME) | |
9771b263 | 207 | return ssa_ver_to_stridx[SSA_NAME_VERSION (exp)]; |
8b57bfeb JJ |
208 | |
209 | if (TREE_CODE (exp) == ADDR_EXPR) | |
210 | { | |
211 | int idx = get_addr_stridx (TREE_OPERAND (exp, 0)); | |
212 | if (idx != 0) | |
213 | return idx; | |
214 | } | |
215 | ||
b3c3685a JJ |
216 | s = string_constant (exp, &o); |
217 | if (s != NULL_TREE | |
9541ffee | 218 | && (o == NULL_TREE || tree_fits_shwi_p (o)) |
b3c3685a | 219 | && TREE_STRING_LENGTH (s) > 0) |
8b57bfeb | 220 | { |
9439e9a1 | 221 | HOST_WIDE_INT offset = o ? tree_to_shwi (o) : 0; |
b3c3685a JJ |
222 | const char *p = TREE_STRING_POINTER (s); |
223 | int max = TREE_STRING_LENGTH (s) - 1; | |
224 | ||
225 | if (p[max] == '\0' && offset >= 0 && offset <= max) | |
226 | return ~(int) strlen (p + offset); | |
8b57bfeb JJ |
227 | } |
228 | return 0; | |
229 | } | |
230 | ||
231 | /* Return true if strinfo vector is shared with the immediate dominator. */ | |
232 | ||
233 | static inline bool | |
234 | strinfo_shared (void) | |
235 | { | |
9771b263 DN |
236 | return vec_safe_length (stridx_to_strinfo) |
237 | && (*stridx_to_strinfo)[0] != NULL; | |
8b57bfeb JJ |
238 | } |
239 | ||
240 | /* Unshare strinfo vector that is shared with the immediate dominator. */ | |
241 | ||
242 | static void | |
243 | unshare_strinfo_vec (void) | |
244 | { | |
245 | strinfo si; | |
246 | unsigned int i = 0; | |
247 | ||
248 | gcc_assert (strinfo_shared ()); | |
9771b263 DN |
249 | stridx_to_strinfo = vec_safe_copy (stridx_to_strinfo); |
250 | for (i = 1; vec_safe_iterate (stridx_to_strinfo, i, &si); ++i) | |
8b57bfeb JJ |
251 | if (si != NULL) |
252 | si->refcount++; | |
9771b263 | 253 | (*stridx_to_strinfo)[0] = NULL; |
8b57bfeb JJ |
254 | } |
255 | ||
256 | /* Attempt to create a string index for exp, ADDR_EXPR's operand. | |
257 | Return a pointer to the location where the string index can | |
258 | be stored (if 0) or is stored, or NULL if this can't be tracked. */ | |
259 | ||
260 | static int * | |
261 | addr_stridxptr (tree exp) | |
262 | { | |
4a8fb1a1 | 263 | decl_stridxlist_map **slot; |
8b57bfeb JJ |
264 | struct decl_stridxlist_map ent; |
265 | struct stridxlist *list; | |
266 | HOST_WIDE_INT off; | |
267 | ||
268 | tree base = get_addr_base_and_unit_offset (exp, &off); | |
269 | if (base == NULL_TREE || !DECL_P (base)) | |
270 | return NULL; | |
271 | ||
4a8fb1a1 | 272 | if (!decl_to_stridxlist_htab.is_created ()) |
8b57bfeb | 273 | { |
4a8fb1a1 | 274 | decl_to_stridxlist_htab.create (64); |
8b57bfeb JJ |
275 | gcc_obstack_init (&stridx_obstack); |
276 | } | |
277 | ent.base.from = base; | |
4a8fb1a1 LC |
278 | slot = decl_to_stridxlist_htab.find_slot_with_hash (&ent, DECL_UID (base), |
279 | INSERT); | |
8b57bfeb JJ |
280 | if (*slot) |
281 | { | |
282 | int i; | |
4a8fb1a1 | 283 | list = &(*slot)->list; |
8b57bfeb JJ |
284 | for (i = 0; i < 16; i++) |
285 | { | |
286 | if (list->offset == off) | |
287 | return &list->idx; | |
288 | if (list->next == NULL) | |
289 | break; | |
290 | } | |
291 | if (i == 16) | |
292 | return NULL; | |
293 | list->next = XOBNEW (&stridx_obstack, struct stridxlist); | |
294 | list = list->next; | |
295 | } | |
296 | else | |
297 | { | |
298 | struct decl_stridxlist_map *e | |
299 | = XOBNEW (&stridx_obstack, struct decl_stridxlist_map); | |
300 | e->base.from = base; | |
4a8fb1a1 | 301 | *slot = e; |
8b57bfeb JJ |
302 | list = &e->list; |
303 | } | |
304 | list->next = NULL; | |
305 | list->offset = off; | |
306 | list->idx = 0; | |
307 | return &list->idx; | |
308 | } | |
309 | ||
310 | /* Create a new string index, or return 0 if reached limit. */ | |
311 | ||
312 | static int | |
313 | new_stridx (tree exp) | |
314 | { | |
315 | int idx; | |
316 | if (max_stridx >= PARAM_VALUE (PARAM_MAX_TRACKED_STRLENS)) | |
317 | return 0; | |
318 | if (TREE_CODE (exp) == SSA_NAME) | |
319 | { | |
320 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (exp)) | |
321 | return 0; | |
322 | idx = max_stridx++; | |
9771b263 | 323 | ssa_ver_to_stridx[SSA_NAME_VERSION (exp)] = idx; |
8b57bfeb JJ |
324 | return idx; |
325 | } | |
326 | if (TREE_CODE (exp) == ADDR_EXPR) | |
327 | { | |
328 | int *pidx = addr_stridxptr (TREE_OPERAND (exp, 0)); | |
329 | if (pidx != NULL) | |
330 | { | |
331 | gcc_assert (*pidx == 0); | |
332 | *pidx = max_stridx++; | |
333 | return *pidx; | |
334 | } | |
335 | } | |
336 | return 0; | |
337 | } | |
338 | ||
339 | /* Like new_stridx, but for ADDR_EXPR's operand instead. */ | |
340 | ||
341 | static int | |
342 | new_addr_stridx (tree exp) | |
343 | { | |
344 | int *pidx; | |
345 | if (max_stridx >= PARAM_VALUE (PARAM_MAX_TRACKED_STRLENS)) | |
346 | return 0; | |
347 | pidx = addr_stridxptr (exp); | |
348 | if (pidx != NULL) | |
349 | { | |
350 | gcc_assert (*pidx == 0); | |
351 | *pidx = max_stridx++; | |
352 | return *pidx; | |
353 | } | |
354 | return 0; | |
355 | } | |
356 | ||
357 | /* Create a new strinfo. */ | |
358 | ||
359 | static strinfo | |
360 | new_strinfo (tree ptr, int idx, tree length) | |
361 | { | |
362 | strinfo si = (strinfo) pool_alloc (strinfo_pool); | |
363 | si->length = length; | |
364 | si->ptr = ptr; | |
365 | si->stmt = NULL; | |
366 | si->endptr = NULL_TREE; | |
367 | si->refcount = 1; | |
368 | si->idx = idx; | |
369 | si->first = 0; | |
370 | si->prev = 0; | |
371 | si->next = 0; | |
372 | si->writable = false; | |
373 | si->dont_invalidate = false; | |
374 | return si; | |
375 | } | |
376 | ||
377 | /* Decrease strinfo refcount and free it if not referenced anymore. */ | |
378 | ||
379 | static inline void | |
380 | free_strinfo (strinfo si) | |
381 | { | |
382 | if (si && --si->refcount == 0) | |
383 | pool_free (strinfo_pool, si); | |
384 | } | |
385 | ||
386 | /* Return strinfo vector entry IDX. */ | |
387 | ||
388 | static inline strinfo | |
389 | get_strinfo (int idx) | |
390 | { | |
9771b263 | 391 | if (vec_safe_length (stridx_to_strinfo) <= (unsigned int) idx) |
8b57bfeb | 392 | return NULL; |
9771b263 | 393 | return (*stridx_to_strinfo)[idx]; |
8b57bfeb JJ |
394 | } |
395 | ||
396 | /* Set strinfo in the vector entry IDX to SI. */ | |
397 | ||
398 | static inline void | |
399 | set_strinfo (int idx, strinfo si) | |
400 | { | |
9771b263 | 401 | if (vec_safe_length (stridx_to_strinfo) && (*stridx_to_strinfo)[0]) |
8b57bfeb | 402 | unshare_strinfo_vec (); |
9771b263 DN |
403 | if (vec_safe_length (stridx_to_strinfo) <= (unsigned int) idx) |
404 | vec_safe_grow_cleared (stridx_to_strinfo, idx + 1); | |
405 | (*stridx_to_strinfo)[idx] = si; | |
8b57bfeb JJ |
406 | } |
407 | ||
408 | /* Return string length, or NULL if it can't be computed. */ | |
409 | ||
410 | static tree | |
411 | get_string_length (strinfo si) | |
412 | { | |
413 | if (si->length) | |
414 | return si->length; | |
415 | ||
416 | if (si->stmt) | |
417 | { | |
418 | gimple stmt = si->stmt, lenstmt; | |
83d5977e | 419 | tree callee, lhs, fn, tem; |
8b57bfeb JJ |
420 | location_t loc; |
421 | gimple_stmt_iterator gsi; | |
422 | ||
423 | gcc_assert (is_gimple_call (stmt)); | |
424 | callee = gimple_call_fndecl (stmt); | |
425 | gcc_assert (callee && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL); | |
426 | lhs = gimple_call_lhs (stmt); | |
93a90db6 | 427 | gcc_assert (builtin_decl_implicit_p (BUILT_IN_STPCPY)); |
8b57bfeb JJ |
428 | /* unshare_strinfo is intentionally not called here. The (delayed) |
429 | transformation of strcpy or strcat into stpcpy is done at the place | |
430 | of the former strcpy/strcat call and so can affect all the strinfos | |
431 | with the same stmt. If they were unshared before and transformation | |
432 | has been already done, the handling of BUILT_IN_STPCPY{,_CHK} should | |
433 | just compute the right length. */ | |
434 | switch (DECL_FUNCTION_CODE (callee)) | |
435 | { | |
436 | case BUILT_IN_STRCAT: | |
437 | case BUILT_IN_STRCAT_CHK: | |
438 | gsi = gsi_for_stmt (stmt); | |
e79983f4 | 439 | fn = builtin_decl_implicit (BUILT_IN_STRLEN); |
8b57bfeb | 440 | gcc_assert (lhs == NULL_TREE); |
8b57bfeb JJ |
441 | tem = unshare_expr (gimple_call_arg (stmt, 0)); |
442 | lenstmt = gimple_build_call (fn, 1, tem); | |
83d5977e | 443 | lhs = make_ssa_name (TREE_TYPE (TREE_TYPE (fn)), lenstmt); |
8b57bfeb JJ |
444 | gimple_call_set_lhs (lenstmt, lhs); |
445 | gimple_set_vuse (lenstmt, gimple_vuse (stmt)); | |
446 | gsi_insert_before (&gsi, lenstmt, GSI_SAME_STMT); | |
8b57bfeb | 447 | tem = gimple_call_arg (stmt, 0); |
33960e2e TG |
448 | if (!ptrofftype_p (TREE_TYPE (lhs))) |
449 | { | |
450 | lhs = convert_to_ptrofftype (lhs); | |
451 | lhs = force_gimple_operand_gsi (&gsi, lhs, true, NULL_TREE, | |
452 | true, GSI_SAME_STMT); | |
453 | } | |
8b57bfeb | 454 | lenstmt |
83d5977e RG |
455 | = gimple_build_assign_with_ops |
456 | (POINTER_PLUS_EXPR, | |
457 | make_ssa_name (TREE_TYPE (gimple_call_arg (stmt, 0)), NULL), | |
458 | tem, lhs); | |
8b57bfeb JJ |
459 | gsi_insert_before (&gsi, lenstmt, GSI_SAME_STMT); |
460 | gimple_call_set_arg (stmt, 0, gimple_assign_lhs (lenstmt)); | |
461 | lhs = NULL_TREE; | |
462 | /* FALLTHRU */ | |
463 | case BUILT_IN_STRCPY: | |
464 | case BUILT_IN_STRCPY_CHK: | |
465 | if (gimple_call_num_args (stmt) == 2) | |
e79983f4 | 466 | fn = builtin_decl_implicit (BUILT_IN_STPCPY); |
8b57bfeb | 467 | else |
e79983f4 | 468 | fn = builtin_decl_explicit (BUILT_IN_STPCPY_CHK); |
8b57bfeb JJ |
469 | gcc_assert (lhs == NULL_TREE); |
470 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
471 | { | |
472 | fprintf (dump_file, "Optimizing: "); | |
473 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
474 | } | |
475 | gimple_call_set_fndecl (stmt, fn); | |
83d5977e | 476 | lhs = make_ssa_name (TREE_TYPE (TREE_TYPE (fn)), stmt); |
8b57bfeb JJ |
477 | gimple_call_set_lhs (stmt, lhs); |
478 | update_stmt (stmt); | |
479 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
480 | { | |
481 | fprintf (dump_file, "into: "); | |
482 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
483 | } | |
484 | /* FALLTHRU */ | |
485 | case BUILT_IN_STPCPY: | |
486 | case BUILT_IN_STPCPY_CHK: | |
487 | gcc_assert (lhs != NULL_TREE); | |
488 | loc = gimple_location (stmt); | |
489 | si->endptr = lhs; | |
490 | si->stmt = NULL; | |
491 | lhs = fold_convert_loc (loc, size_type_node, lhs); | |
492 | si->length = fold_convert_loc (loc, size_type_node, si->ptr); | |
493 | si->length = fold_build2_loc (loc, MINUS_EXPR, size_type_node, | |
494 | lhs, si->length); | |
495 | break; | |
496 | default: | |
497 | gcc_unreachable (); | |
498 | break; | |
499 | } | |
500 | } | |
501 | ||
502 | return si->length; | |
503 | } | |
504 | ||
505 | /* Invalidate string length information for strings whose length | |
506 | might change due to stores in stmt. */ | |
507 | ||
508 | static bool | |
509 | maybe_invalidate (gimple stmt) | |
510 | { | |
511 | strinfo si; | |
512 | unsigned int i; | |
513 | bool nonempty = false; | |
514 | ||
9771b263 | 515 | for (i = 1; vec_safe_iterate (stridx_to_strinfo, i, &si); ++i) |
8b57bfeb JJ |
516 | if (si != NULL) |
517 | { | |
518 | if (!si->dont_invalidate) | |
519 | { | |
520 | ao_ref r; | |
521 | ao_ref_init_from_ptr_and_size (&r, si->ptr, NULL_TREE); | |
522 | if (stmt_may_clobber_ref_p_1 (stmt, &r)) | |
523 | { | |
524 | set_strinfo (i, NULL); | |
525 | free_strinfo (si); | |
526 | continue; | |
527 | } | |
528 | } | |
529 | si->dont_invalidate = false; | |
530 | nonempty = true; | |
531 | } | |
532 | return nonempty; | |
533 | } | |
534 | ||
535 | /* Unshare strinfo record SI, if it has recount > 1 or | |
536 | if stridx_to_strinfo vector is shared with some other | |
537 | bbs. */ | |
538 | ||
539 | static strinfo | |
540 | unshare_strinfo (strinfo si) | |
541 | { | |
542 | strinfo nsi; | |
543 | ||
544 | if (si->refcount == 1 && !strinfo_shared ()) | |
545 | return si; | |
546 | ||
547 | nsi = new_strinfo (si->ptr, si->idx, si->length); | |
548 | nsi->stmt = si->stmt; | |
549 | nsi->endptr = si->endptr; | |
550 | nsi->first = si->first; | |
551 | nsi->prev = si->prev; | |
552 | nsi->next = si->next; | |
553 | nsi->writable = si->writable; | |
554 | set_strinfo (si->idx, nsi); | |
555 | free_strinfo (si); | |
556 | return nsi; | |
557 | } | |
558 | ||
559 | /* Return first strinfo in the related strinfo chain | |
560 | if all strinfos in between belong to the chain, otherwise | |
561 | NULL. */ | |
562 | ||
563 | static strinfo | |
564 | verify_related_strinfos (strinfo origsi) | |
565 | { | |
566 | strinfo si = origsi, psi; | |
567 | ||
568 | if (origsi->first == 0) | |
569 | return NULL; | |
570 | for (; si->prev; si = psi) | |
571 | { | |
572 | if (si->first != origsi->first) | |
573 | return NULL; | |
574 | psi = get_strinfo (si->prev); | |
575 | if (psi == NULL) | |
576 | return NULL; | |
577 | if (psi->next != si->idx) | |
578 | return NULL; | |
579 | } | |
580 | if (si->idx != si->first) | |
581 | return NULL; | |
582 | return si; | |
583 | } | |
584 | ||
585 | /* Note that PTR, a pointer SSA_NAME initialized in the current stmt, points | |
586 | to a zero-length string and if possible chain it to a related strinfo | |
587 | chain whose part is or might be CHAINSI. */ | |
588 | ||
589 | static strinfo | |
590 | zero_length_string (tree ptr, strinfo chainsi) | |
591 | { | |
592 | strinfo si; | |
593 | int idx; | |
594 | gcc_checking_assert (TREE_CODE (ptr) == SSA_NAME | |
595 | && get_stridx (ptr) == 0); | |
596 | ||
597 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ptr)) | |
598 | return NULL; | |
599 | if (chainsi != NULL) | |
600 | { | |
601 | si = verify_related_strinfos (chainsi); | |
602 | if (si) | |
603 | { | |
604 | chainsi = si; | |
605 | for (; chainsi->next; chainsi = si) | |
606 | { | |
607 | if (chainsi->endptr == NULL_TREE) | |
608 | { | |
609 | chainsi = unshare_strinfo (chainsi); | |
610 | chainsi->endptr = ptr; | |
611 | } | |
612 | si = get_strinfo (chainsi->next); | |
613 | if (si == NULL | |
614 | || si->first != chainsi->first | |
615 | || si->prev != chainsi->idx) | |
616 | break; | |
617 | } | |
93a90db6 | 618 | gcc_assert (chainsi->length || chainsi->stmt); |
8b57bfeb JJ |
619 | if (chainsi->endptr == NULL_TREE) |
620 | { | |
621 | chainsi = unshare_strinfo (chainsi); | |
622 | chainsi->endptr = ptr; | |
623 | } | |
93a90db6 | 624 | if (chainsi->length && integer_zerop (chainsi->length)) |
8b57bfeb JJ |
625 | { |
626 | if (chainsi->next) | |
627 | { | |
628 | chainsi = unshare_strinfo (chainsi); | |
629 | chainsi->next = 0; | |
630 | } | |
9771b263 | 631 | ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] = chainsi->idx; |
8b57bfeb JJ |
632 | return chainsi; |
633 | } | |
634 | } | |
635 | else if (chainsi->first || chainsi->prev || chainsi->next) | |
636 | { | |
637 | chainsi = unshare_strinfo (chainsi); | |
638 | chainsi->first = 0; | |
639 | chainsi->prev = 0; | |
640 | chainsi->next = 0; | |
641 | } | |
642 | } | |
643 | idx = new_stridx (ptr); | |
644 | if (idx == 0) | |
645 | return NULL; | |
646 | si = new_strinfo (ptr, idx, build_int_cst (size_type_node, 0)); | |
647 | set_strinfo (idx, si); | |
648 | si->endptr = ptr; | |
649 | if (chainsi != NULL) | |
650 | { | |
651 | chainsi = unshare_strinfo (chainsi); | |
652 | if (chainsi->first == 0) | |
653 | chainsi->first = chainsi->idx; | |
654 | chainsi->next = idx; | |
93a90db6 AK |
655 | if (chainsi->endptr == NULL_TREE) |
656 | chainsi->endptr = ptr; | |
8b57bfeb JJ |
657 | si->prev = chainsi->idx; |
658 | si->first = chainsi->first; | |
659 | si->writable = chainsi->writable; | |
660 | } | |
661 | return si; | |
662 | } | |
663 | ||
664 | /* For strinfo ORIGSI whose length has been just updated | |
665 | update also related strinfo lengths (add ADJ to each, | |
666 | but don't adjust ORIGSI). */ | |
667 | ||
668 | static void | |
669 | adjust_related_strinfos (location_t loc, strinfo origsi, tree adj) | |
670 | { | |
671 | strinfo si = verify_related_strinfos (origsi); | |
672 | ||
673 | if (si == NULL) | |
674 | return; | |
675 | ||
676 | while (1) | |
677 | { | |
678 | strinfo nsi; | |
679 | ||
680 | if (si != origsi) | |
681 | { | |
682 | tree tem; | |
683 | ||
684 | si = unshare_strinfo (si); | |
93a90db6 AK |
685 | if (si->length) |
686 | { | |
687 | tem = fold_convert_loc (loc, TREE_TYPE (si->length), adj); | |
688 | si->length = fold_build2_loc (loc, PLUS_EXPR, | |
689 | TREE_TYPE (si->length), si->length, | |
690 | tem); | |
691 | } | |
692 | else if (si->stmt != NULL) | |
693 | /* Delayed length computation is unaffected. */ | |
694 | ; | |
695 | else | |
696 | gcc_unreachable (); | |
697 | ||
8b57bfeb JJ |
698 | si->endptr = NULL_TREE; |
699 | si->dont_invalidate = true; | |
700 | } | |
701 | if (si->next == 0) | |
702 | return; | |
703 | nsi = get_strinfo (si->next); | |
704 | if (nsi == NULL | |
705 | || nsi->first != si->first | |
706 | || nsi->prev != si->idx) | |
707 | return; | |
708 | si = nsi; | |
709 | } | |
710 | } | |
711 | ||
712 | /* Find if there are other SSA_NAME pointers equal to PTR | |
713 | for which we don't track their string lengths yet. If so, use | |
714 | IDX for them. */ | |
715 | ||
716 | static void | |
717 | find_equal_ptrs (tree ptr, int idx) | |
718 | { | |
719 | if (TREE_CODE (ptr) != SSA_NAME) | |
720 | return; | |
721 | while (1) | |
722 | { | |
723 | gimple stmt = SSA_NAME_DEF_STMT (ptr); | |
724 | if (!is_gimple_assign (stmt)) | |
725 | return; | |
726 | ptr = gimple_assign_rhs1 (stmt); | |
727 | switch (gimple_assign_rhs_code (stmt)) | |
728 | { | |
729 | case SSA_NAME: | |
730 | break; | |
97246d78 JJ |
731 | CASE_CONVERT: |
732 | if (!POINTER_TYPE_P (TREE_TYPE (ptr))) | |
733 | return; | |
734 | if (TREE_CODE (ptr) == SSA_NAME) | |
735 | break; | |
736 | if (TREE_CODE (ptr) != ADDR_EXPR) | |
737 | return; | |
738 | /* FALLTHRU */ | |
8b57bfeb JJ |
739 | case ADDR_EXPR: |
740 | { | |
741 | int *pidx = addr_stridxptr (TREE_OPERAND (ptr, 0)); | |
742 | if (pidx != NULL && *pidx == 0) | |
743 | *pidx = idx; | |
744 | return; | |
745 | } | |
8b57bfeb JJ |
746 | default: |
747 | return; | |
748 | } | |
749 | ||
750 | /* We might find an endptr created in this pass. Grow the | |
751 | vector in that case. */ | |
9771b263 DN |
752 | if (ssa_ver_to_stridx.length () <= SSA_NAME_VERSION (ptr)) |
753 | ssa_ver_to_stridx.safe_grow_cleared (num_ssa_names); | |
8b57bfeb | 754 | |
9771b263 | 755 | if (ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] != 0) |
8b57bfeb | 756 | return; |
9771b263 | 757 | ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] = idx; |
8b57bfeb JJ |
758 | } |
759 | } | |
760 | ||
761 | /* If the last .MEM setter statement before STMT is | |
762 | memcpy (x, y, strlen (y) + 1), the only .MEM use of it is STMT | |
763 | and STMT is known to overwrite x[strlen (x)], adjust the last memcpy to | |
764 | just memcpy (x, y, strlen (y)). SI must be the zero length | |
765 | strinfo. */ | |
766 | ||
767 | static void | |
768 | adjust_last_stmt (strinfo si, gimple stmt, bool is_strcat) | |
769 | { | |
770 | tree vuse, callee, len; | |
771 | struct laststmt_struct last = laststmt; | |
772 | strinfo lastsi, firstsi; | |
773 | ||
774 | laststmt.stmt = NULL; | |
775 | laststmt.len = NULL_TREE; | |
776 | laststmt.stridx = 0; | |
777 | ||
778 | if (last.stmt == NULL) | |
779 | return; | |
780 | ||
781 | vuse = gimple_vuse (stmt); | |
782 | if (vuse == NULL_TREE | |
783 | || SSA_NAME_DEF_STMT (vuse) != last.stmt | |
784 | || !has_single_use (vuse)) | |
785 | return; | |
786 | ||
787 | gcc_assert (last.stridx > 0); | |
788 | lastsi = get_strinfo (last.stridx); | |
789 | if (lastsi == NULL) | |
790 | return; | |
791 | ||
792 | if (lastsi != si) | |
793 | { | |
794 | if (lastsi->first == 0 || lastsi->first != si->first) | |
795 | return; | |
796 | ||
797 | firstsi = verify_related_strinfos (si); | |
798 | if (firstsi == NULL) | |
799 | return; | |
800 | while (firstsi != lastsi) | |
801 | { | |
802 | strinfo nextsi; | |
803 | if (firstsi->next == 0) | |
804 | return; | |
805 | nextsi = get_strinfo (firstsi->next); | |
806 | if (nextsi == NULL | |
807 | || nextsi->prev != firstsi->idx | |
808 | || nextsi->first != si->first) | |
809 | return; | |
810 | firstsi = nextsi; | |
811 | } | |
812 | } | |
813 | ||
814 | if (!is_strcat) | |
815 | { | |
816 | if (si->length == NULL_TREE || !integer_zerop (si->length)) | |
817 | return; | |
818 | } | |
819 | ||
820 | if (is_gimple_assign (last.stmt)) | |
821 | { | |
822 | gimple_stmt_iterator gsi; | |
823 | ||
824 | if (!integer_zerop (gimple_assign_rhs1 (last.stmt))) | |
825 | return; | |
826 | if (stmt_could_throw_p (last.stmt)) | |
827 | return; | |
828 | gsi = gsi_for_stmt (last.stmt); | |
829 | unlink_stmt_vdef (last.stmt); | |
830 | release_defs (last.stmt); | |
831 | gsi_remove (&gsi, true); | |
832 | return; | |
833 | } | |
834 | ||
3626621a | 835 | if (!gimple_call_builtin_p (last.stmt, BUILT_IN_NORMAL)) |
8b57bfeb JJ |
836 | return; |
837 | ||
3626621a | 838 | callee = gimple_call_fndecl (last.stmt); |
8b57bfeb JJ |
839 | switch (DECL_FUNCTION_CODE (callee)) |
840 | { | |
841 | case BUILT_IN_MEMCPY: | |
842 | case BUILT_IN_MEMCPY_CHK: | |
843 | break; | |
844 | default: | |
845 | return; | |
846 | } | |
847 | ||
848 | len = gimple_call_arg (last.stmt, 2); | |
cc269bb6 | 849 | if (tree_fits_uhwi_p (len)) |
8b57bfeb | 850 | { |
cc269bb6 | 851 | if (!tree_fits_uhwi_p (last.len) |
8b57bfeb | 852 | || integer_zerop (len) |
7d362f6c | 853 | || tree_to_uhwi (len) != tree_to_uhwi (last.len) + 1) |
8b57bfeb JJ |
854 | return; |
855 | /* Don't adjust the length if it is divisible by 4, it is more efficient | |
856 | to store the extra '\0' in that case. */ | |
7d362f6c | 857 | if ((tree_to_uhwi (len) & 3) == 0) |
8b57bfeb JJ |
858 | return; |
859 | } | |
860 | else if (TREE_CODE (len) == SSA_NAME) | |
861 | { | |
862 | gimple def_stmt = SSA_NAME_DEF_STMT (len); | |
863 | if (!is_gimple_assign (def_stmt) | |
864 | || gimple_assign_rhs_code (def_stmt) != PLUS_EXPR | |
865 | || gimple_assign_rhs1 (def_stmt) != last.len | |
866 | || !integer_onep (gimple_assign_rhs2 (def_stmt))) | |
867 | return; | |
868 | } | |
869 | else | |
870 | return; | |
871 | ||
872 | gimple_call_set_arg (last.stmt, 2, last.len); | |
873 | update_stmt (last.stmt); | |
874 | } | |
875 | ||
876 | /* Handle a strlen call. If strlen of the argument is known, replace | |
877 | the strlen call with the known value, otherwise remember that strlen | |
878 | of the argument is stored in the lhs SSA_NAME. */ | |
879 | ||
880 | static void | |
881 | handle_builtin_strlen (gimple_stmt_iterator *gsi) | |
882 | { | |
883 | int idx; | |
884 | tree src; | |
885 | gimple stmt = gsi_stmt (*gsi); | |
886 | tree lhs = gimple_call_lhs (stmt); | |
887 | ||
888 | if (lhs == NULL_TREE) | |
889 | return; | |
890 | ||
891 | src = gimple_call_arg (stmt, 0); | |
892 | idx = get_stridx (src); | |
893 | if (idx) | |
894 | { | |
895 | strinfo si = NULL; | |
896 | tree rhs; | |
897 | ||
898 | if (idx < 0) | |
899 | rhs = build_int_cst (TREE_TYPE (lhs), ~idx); | |
900 | else | |
901 | { | |
902 | rhs = NULL_TREE; | |
903 | si = get_strinfo (idx); | |
904 | if (si != NULL) | |
905 | rhs = get_string_length (si); | |
906 | } | |
907 | if (rhs != NULL_TREE) | |
908 | { | |
909 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
910 | { | |
911 | fprintf (dump_file, "Optimizing: "); | |
912 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
913 | } | |
914 | rhs = unshare_expr (rhs); | |
915 | if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs))) | |
916 | rhs = fold_convert_loc (gimple_location (stmt), | |
917 | TREE_TYPE (lhs), rhs); | |
918 | if (!update_call_from_tree (gsi, rhs)) | |
919 | gimplify_and_update_call_from_tree (gsi, rhs); | |
920 | stmt = gsi_stmt (*gsi); | |
921 | update_stmt (stmt); | |
922 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
923 | { | |
924 | fprintf (dump_file, "into: "); | |
925 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
926 | } | |
927 | if (si != NULL | |
928 | && TREE_CODE (si->length) != SSA_NAME | |
929 | && TREE_CODE (si->length) != INTEGER_CST | |
930 | && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
931 | { | |
932 | si = unshare_strinfo (si); | |
933 | si->length = lhs; | |
934 | } | |
935 | return; | |
936 | } | |
937 | } | |
938 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
939 | return; | |
940 | if (idx == 0) | |
941 | idx = new_stridx (src); | |
942 | else if (get_strinfo (idx) != NULL) | |
943 | return; | |
944 | if (idx) | |
945 | { | |
946 | strinfo si = new_strinfo (src, idx, lhs); | |
947 | set_strinfo (idx, si); | |
948 | find_equal_ptrs (src, idx); | |
949 | } | |
950 | } | |
951 | ||
952 | /* Handle a strchr call. If strlen of the first argument is known, replace | |
953 | the strchr (x, 0) call with the endptr or x + strlen, otherwise remember | |
954 | that lhs of the call is endptr and strlen of the argument is endptr - x. */ | |
955 | ||
956 | static void | |
957 | handle_builtin_strchr (gimple_stmt_iterator *gsi) | |
958 | { | |
959 | int idx; | |
960 | tree src; | |
961 | gimple stmt = gsi_stmt (*gsi); | |
962 | tree lhs = gimple_call_lhs (stmt); | |
963 | ||
964 | if (lhs == NULL_TREE) | |
965 | return; | |
966 | ||
967 | if (!integer_zerop (gimple_call_arg (stmt, 1))) | |
968 | return; | |
969 | ||
970 | src = gimple_call_arg (stmt, 0); | |
971 | idx = get_stridx (src); | |
972 | if (idx) | |
973 | { | |
974 | strinfo si = NULL; | |
975 | tree rhs; | |
976 | ||
977 | if (idx < 0) | |
978 | rhs = build_int_cst (size_type_node, ~idx); | |
979 | else | |
980 | { | |
981 | rhs = NULL_TREE; | |
982 | si = get_strinfo (idx); | |
983 | if (si != NULL) | |
984 | rhs = get_string_length (si); | |
985 | } | |
986 | if (rhs != NULL_TREE) | |
987 | { | |
988 | location_t loc = gimple_location (stmt); | |
989 | ||
990 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
991 | { | |
992 | fprintf (dump_file, "Optimizing: "); | |
993 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
994 | } | |
995 | if (si != NULL && si->endptr != NULL_TREE) | |
996 | { | |
997 | rhs = unshare_expr (si->endptr); | |
998 | if (!useless_type_conversion_p (TREE_TYPE (lhs), | |
999 | TREE_TYPE (rhs))) | |
1000 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); | |
1001 | } | |
1002 | else | |
1003 | { | |
1004 | rhs = fold_convert_loc (loc, sizetype, unshare_expr (rhs)); | |
1005 | rhs = fold_build2_loc (loc, POINTER_PLUS_EXPR, | |
1006 | TREE_TYPE (src), src, rhs); | |
1007 | if (!useless_type_conversion_p (TREE_TYPE (lhs), | |
1008 | TREE_TYPE (rhs))) | |
1009 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); | |
1010 | } | |
1011 | if (!update_call_from_tree (gsi, rhs)) | |
1012 | gimplify_and_update_call_from_tree (gsi, rhs); | |
1013 | stmt = gsi_stmt (*gsi); | |
1014 | update_stmt (stmt); | |
1015 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1016 | { | |
1017 | fprintf (dump_file, "into: "); | |
1018 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1019 | } | |
1020 | if (si != NULL | |
1021 | && si->endptr == NULL_TREE | |
1022 | && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
1023 | { | |
1024 | si = unshare_strinfo (si); | |
1025 | si->endptr = lhs; | |
1026 | } | |
1027 | zero_length_string (lhs, si); | |
1028 | return; | |
1029 | } | |
1030 | } | |
1031 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
1032 | return; | |
1033 | if (TREE_CODE (src) != SSA_NAME || !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (src)) | |
1034 | { | |
1035 | if (idx == 0) | |
1036 | idx = new_stridx (src); | |
1037 | else if (get_strinfo (idx) != NULL) | |
1038 | { | |
1039 | zero_length_string (lhs, NULL); | |
1040 | return; | |
1041 | } | |
1042 | if (idx) | |
1043 | { | |
1044 | location_t loc = gimple_location (stmt); | |
1045 | tree lhsu = fold_convert_loc (loc, size_type_node, lhs); | |
1046 | tree srcu = fold_convert_loc (loc, size_type_node, src); | |
1047 | tree length = fold_build2_loc (loc, MINUS_EXPR, | |
1048 | size_type_node, lhsu, srcu); | |
1049 | strinfo si = new_strinfo (src, idx, length); | |
1050 | si->endptr = lhs; | |
1051 | set_strinfo (idx, si); | |
1052 | find_equal_ptrs (src, idx); | |
1053 | zero_length_string (lhs, si); | |
1054 | } | |
1055 | } | |
1056 | else | |
1057 | zero_length_string (lhs, NULL); | |
1058 | } | |
1059 | ||
1060 | /* Handle a strcpy-like ({st{r,p}cpy,__st{r,p}cpy_chk}) call. | |
1061 | If strlen of the second argument is known, strlen of the first argument | |
1062 | is the same after this call. Furthermore, attempt to convert it to | |
1063 | memcpy. */ | |
1064 | ||
1065 | static void | |
1066 | handle_builtin_strcpy (enum built_in_function bcode, gimple_stmt_iterator *gsi) | |
1067 | { | |
1068 | int idx, didx; | |
1069 | tree src, dst, srclen, len, lhs, args, type, fn, oldlen; | |
1070 | bool success; | |
1071 | gimple stmt = gsi_stmt (*gsi); | |
1072 | strinfo si, dsi, olddsi, zsi; | |
1073 | location_t loc; | |
1074 | ||
1075 | src = gimple_call_arg (stmt, 1); | |
1076 | dst = gimple_call_arg (stmt, 0); | |
1077 | lhs = gimple_call_lhs (stmt); | |
1078 | idx = get_stridx (src); | |
1079 | si = NULL; | |
1080 | if (idx > 0) | |
1081 | si = get_strinfo (idx); | |
1082 | ||
1083 | didx = get_stridx (dst); | |
1084 | olddsi = NULL; | |
1085 | oldlen = NULL_TREE; | |
1086 | if (didx > 0) | |
1087 | olddsi = get_strinfo (didx); | |
1088 | else if (didx < 0) | |
1089 | return; | |
1090 | ||
1091 | if (olddsi != NULL) | |
1092 | adjust_last_stmt (olddsi, stmt, false); | |
1093 | ||
1094 | srclen = NULL_TREE; | |
1095 | if (si != NULL) | |
1096 | srclen = get_string_length (si); | |
1097 | else if (idx < 0) | |
1098 | srclen = build_int_cst (size_type_node, ~idx); | |
1099 | ||
1100 | loc = gimple_location (stmt); | |
1101 | if (srclen == NULL_TREE) | |
1102 | switch (bcode) | |
1103 | { | |
1104 | case BUILT_IN_STRCPY: | |
1105 | case BUILT_IN_STRCPY_CHK: | |
e79983f4 | 1106 | if (lhs != NULL_TREE || !builtin_decl_implicit_p (BUILT_IN_STPCPY)) |
8b57bfeb JJ |
1107 | return; |
1108 | break; | |
1109 | case BUILT_IN_STPCPY: | |
1110 | case BUILT_IN_STPCPY_CHK: | |
1111 | if (lhs == NULL_TREE) | |
1112 | return; | |
1113 | else | |
1114 | { | |
1115 | tree lhsuint = fold_convert_loc (loc, size_type_node, lhs); | |
1116 | srclen = fold_convert_loc (loc, size_type_node, dst); | |
1117 | srclen = fold_build2_loc (loc, MINUS_EXPR, size_type_node, | |
1118 | lhsuint, srclen); | |
1119 | } | |
1120 | break; | |
1121 | default: | |
1122 | gcc_unreachable (); | |
1123 | } | |
1124 | ||
1125 | if (didx == 0) | |
1126 | { | |
1127 | didx = new_stridx (dst); | |
1128 | if (didx == 0) | |
1129 | return; | |
1130 | } | |
1131 | if (olddsi != NULL) | |
1132 | { | |
1133 | oldlen = olddsi->length; | |
1134 | dsi = unshare_strinfo (olddsi); | |
1135 | dsi->length = srclen; | |
1136 | /* Break the chain, so adjust_related_strinfo on later pointers in | |
1137 | the chain won't adjust this one anymore. */ | |
1138 | dsi->next = 0; | |
1139 | dsi->stmt = NULL; | |
1140 | dsi->endptr = NULL_TREE; | |
1141 | } | |
1142 | else | |
1143 | { | |
1144 | dsi = new_strinfo (dst, didx, srclen); | |
1145 | set_strinfo (didx, dsi); | |
1146 | find_equal_ptrs (dst, didx); | |
1147 | } | |
1148 | dsi->writable = true; | |
1149 | dsi->dont_invalidate = true; | |
1150 | ||
1151 | if (dsi->length == NULL_TREE) | |
1152 | { | |
93a90db6 AK |
1153 | strinfo chainsi; |
1154 | ||
8b57bfeb JJ |
1155 | /* If string length of src is unknown, use delayed length |
1156 | computation. If string lenth of dst will be needed, it | |
1157 | can be computed by transforming this strcpy call into | |
1158 | stpcpy and subtracting dst from the return value. */ | |
93a90db6 AK |
1159 | |
1160 | /* Look for earlier strings whose length could be determined if | |
1161 | this strcpy is turned into an stpcpy. */ | |
1162 | ||
1163 | if (dsi->prev != 0 && (chainsi = verify_related_strinfos (dsi)) != NULL) | |
1164 | { | |
1165 | for (; chainsi && chainsi != dsi; chainsi = get_strinfo (chainsi->next)) | |
1166 | { | |
1167 | /* When setting a stmt for delayed length computation | |
1168 | prevent all strinfos through dsi from being | |
1169 | invalidated. */ | |
1170 | chainsi = unshare_strinfo (chainsi); | |
1171 | chainsi->stmt = stmt; | |
1172 | chainsi->length = NULL_TREE; | |
1173 | chainsi->endptr = NULL_TREE; | |
1174 | chainsi->dont_invalidate = true; | |
1175 | } | |
1176 | } | |
8b57bfeb JJ |
1177 | dsi->stmt = stmt; |
1178 | return; | |
1179 | } | |
1180 | ||
1181 | if (olddsi != NULL) | |
1182 | { | |
1183 | tree adj = NULL_TREE; | |
1184 | if (oldlen == NULL_TREE) | |
1185 | ; | |
1186 | else if (integer_zerop (oldlen)) | |
1187 | adj = srclen; | |
1188 | else if (TREE_CODE (oldlen) == INTEGER_CST | |
1189 | || TREE_CODE (srclen) == INTEGER_CST) | |
1190 | adj = fold_build2_loc (loc, MINUS_EXPR, | |
1191 | TREE_TYPE (srclen), srclen, | |
1192 | fold_convert_loc (loc, TREE_TYPE (srclen), | |
1193 | oldlen)); | |
1194 | if (adj != NULL_TREE) | |
1195 | adjust_related_strinfos (loc, dsi, adj); | |
1196 | else | |
1197 | dsi->prev = 0; | |
1198 | } | |
1199 | /* strcpy src may not overlap dst, so src doesn't need to be | |
1200 | invalidated either. */ | |
1201 | if (si != NULL) | |
1202 | si->dont_invalidate = true; | |
1203 | ||
1204 | fn = NULL_TREE; | |
1205 | zsi = NULL; | |
1206 | switch (bcode) | |
1207 | { | |
1208 | case BUILT_IN_STRCPY: | |
e79983f4 | 1209 | fn = builtin_decl_implicit (BUILT_IN_MEMCPY); |
8b57bfeb | 1210 | if (lhs) |
9771b263 | 1211 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] = didx; |
8b57bfeb JJ |
1212 | break; |
1213 | case BUILT_IN_STRCPY_CHK: | |
e79983f4 | 1214 | fn = builtin_decl_explicit (BUILT_IN_MEMCPY_CHK); |
8b57bfeb | 1215 | if (lhs) |
9771b263 | 1216 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] = didx; |
8b57bfeb JJ |
1217 | break; |
1218 | case BUILT_IN_STPCPY: | |
1219 | /* This would need adjustment of the lhs (subtract one), | |
1220 | or detection that the trailing '\0' doesn't need to be | |
1221 | written, if it will be immediately overwritten. | |
e79983f4 | 1222 | fn = builtin_decl_explicit (BUILT_IN_MEMPCPY); */ |
8b57bfeb JJ |
1223 | if (lhs) |
1224 | { | |
1225 | dsi->endptr = lhs; | |
1226 | zsi = zero_length_string (lhs, dsi); | |
1227 | } | |
1228 | break; | |
1229 | case BUILT_IN_STPCPY_CHK: | |
1230 | /* This would need adjustment of the lhs (subtract one), | |
1231 | or detection that the trailing '\0' doesn't need to be | |
1232 | written, if it will be immediately overwritten. | |
e79983f4 | 1233 | fn = builtin_decl_explicit (BUILT_IN_MEMPCPY_CHK); */ |
8b57bfeb JJ |
1234 | if (lhs) |
1235 | { | |
1236 | dsi->endptr = lhs; | |
1237 | zsi = zero_length_string (lhs, dsi); | |
1238 | } | |
1239 | break; | |
1240 | default: | |
1241 | gcc_unreachable (); | |
1242 | } | |
1243 | if (zsi != NULL) | |
1244 | zsi->dont_invalidate = true; | |
1245 | ||
1246 | if (fn == NULL_TREE) | |
1247 | return; | |
1248 | ||
1249 | args = TYPE_ARG_TYPES (TREE_TYPE (fn)); | |
1250 | type = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (args))); | |
1251 | ||
1252 | len = fold_convert_loc (loc, type, unshare_expr (srclen)); | |
1253 | len = fold_build2_loc (loc, PLUS_EXPR, type, len, build_int_cst (type, 1)); | |
1254 | len = force_gimple_operand_gsi (gsi, len, true, NULL_TREE, true, | |
1255 | GSI_SAME_STMT); | |
1256 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1257 | { | |
1258 | fprintf (dump_file, "Optimizing: "); | |
1259 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1260 | } | |
1261 | if (gimple_call_num_args (stmt) == 2) | |
1262 | success = update_gimple_call (gsi, fn, 3, dst, src, len); | |
1263 | else | |
1264 | success = update_gimple_call (gsi, fn, 4, dst, src, len, | |
1265 | gimple_call_arg (stmt, 2)); | |
1266 | if (success) | |
1267 | { | |
1268 | stmt = gsi_stmt (*gsi); | |
1269 | update_stmt (stmt); | |
1270 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1271 | { | |
1272 | fprintf (dump_file, "into: "); | |
1273 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1274 | } | |
1275 | /* Allow adjust_last_stmt to decrease this memcpy's size. */ | |
1276 | laststmt.stmt = stmt; | |
1277 | laststmt.len = srclen; | |
1278 | laststmt.stridx = dsi->idx; | |
1279 | } | |
1280 | else if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1281 | fprintf (dump_file, "not possible.\n"); | |
1282 | } | |
1283 | ||
1284 | /* Handle a memcpy-like ({mem{,p}cpy,__mem{,p}cpy_chk}) call. | |
1285 | If strlen of the second argument is known and length of the third argument | |
1286 | is that plus one, strlen of the first argument is the same after this | |
1287 | call. */ | |
1288 | ||
1289 | static void | |
1290 | handle_builtin_memcpy (enum built_in_function bcode, gimple_stmt_iterator *gsi) | |
1291 | { | |
1292 | int idx, didx; | |
1293 | tree src, dst, len, lhs, oldlen, newlen; | |
1294 | gimple stmt = gsi_stmt (*gsi); | |
1295 | strinfo si, dsi, olddsi; | |
1296 | ||
1297 | len = gimple_call_arg (stmt, 2); | |
1298 | src = gimple_call_arg (stmt, 1); | |
1299 | dst = gimple_call_arg (stmt, 0); | |
1300 | idx = get_stridx (src); | |
1301 | if (idx == 0) | |
1302 | return; | |
1303 | ||
1304 | didx = get_stridx (dst); | |
1305 | olddsi = NULL; | |
1306 | if (didx > 0) | |
1307 | olddsi = get_strinfo (didx); | |
1308 | else if (didx < 0) | |
1309 | return; | |
1310 | ||
1311 | if (olddsi != NULL | |
cc269bb6 | 1312 | && tree_fits_uhwi_p (len) |
8b57bfeb JJ |
1313 | && !integer_zerop (len)) |
1314 | adjust_last_stmt (olddsi, stmt, false); | |
1315 | ||
1316 | if (idx > 0) | |
1317 | { | |
1318 | gimple def_stmt; | |
1319 | ||
1320 | /* Handle memcpy (x, y, l) where l is strlen (y) + 1. */ | |
1321 | si = get_strinfo (idx); | |
1322 | if (si == NULL || si->length == NULL_TREE) | |
1323 | return; | |
1324 | if (TREE_CODE (len) != SSA_NAME) | |
1325 | return; | |
1326 | def_stmt = SSA_NAME_DEF_STMT (len); | |
1327 | if (!is_gimple_assign (def_stmt) | |
1328 | || gimple_assign_rhs_code (def_stmt) != PLUS_EXPR | |
1329 | || gimple_assign_rhs1 (def_stmt) != si->length | |
1330 | || !integer_onep (gimple_assign_rhs2 (def_stmt))) | |
1331 | return; | |
1332 | } | |
1333 | else | |
1334 | { | |
1335 | si = NULL; | |
1336 | /* Handle memcpy (x, "abcd", 5) or | |
1337 | memcpy (x, "abc\0uvw", 7). */ | |
cc269bb6 | 1338 | if (!tree_fits_uhwi_p (len) |
7d362f6c | 1339 | || tree_to_uhwi (len) <= (unsigned HOST_WIDE_INT) ~idx) |
8b57bfeb JJ |
1340 | return; |
1341 | } | |
1342 | ||
1343 | if (olddsi != NULL && TREE_CODE (len) == SSA_NAME) | |
1344 | adjust_last_stmt (olddsi, stmt, false); | |
1345 | ||
1346 | if (didx == 0) | |
1347 | { | |
1348 | didx = new_stridx (dst); | |
1349 | if (didx == 0) | |
1350 | return; | |
1351 | } | |
1352 | if (si != NULL) | |
1353 | newlen = si->length; | |
1354 | else | |
80642376 | 1355 | newlen = build_int_cst (size_type_node, ~idx); |
8b57bfeb JJ |
1356 | oldlen = NULL_TREE; |
1357 | if (olddsi != NULL) | |
1358 | { | |
1359 | dsi = unshare_strinfo (olddsi); | |
1360 | oldlen = olddsi->length; | |
1361 | dsi->length = newlen; | |
1362 | /* Break the chain, so adjust_related_strinfo on later pointers in | |
1363 | the chain won't adjust this one anymore. */ | |
1364 | dsi->next = 0; | |
1365 | dsi->stmt = NULL; | |
1366 | dsi->endptr = NULL_TREE; | |
1367 | } | |
1368 | else | |
1369 | { | |
1370 | dsi = new_strinfo (dst, didx, newlen); | |
1371 | set_strinfo (didx, dsi); | |
1372 | find_equal_ptrs (dst, didx); | |
1373 | } | |
1374 | dsi->writable = true; | |
1375 | dsi->dont_invalidate = true; | |
1376 | if (olddsi != NULL) | |
1377 | { | |
1378 | tree adj = NULL_TREE; | |
1379 | location_t loc = gimple_location (stmt); | |
1380 | if (oldlen == NULL_TREE) | |
1381 | ; | |
1382 | else if (integer_zerop (oldlen)) | |
1383 | adj = dsi->length; | |
1384 | else if (TREE_CODE (oldlen) == INTEGER_CST | |
1385 | || TREE_CODE (dsi->length) == INTEGER_CST) | |
1386 | adj = fold_build2_loc (loc, MINUS_EXPR, | |
1387 | TREE_TYPE (dsi->length), dsi->length, | |
1388 | fold_convert_loc (loc, TREE_TYPE (dsi->length), | |
1389 | oldlen)); | |
1390 | if (adj != NULL_TREE) | |
1391 | adjust_related_strinfos (loc, dsi, adj); | |
1392 | else | |
1393 | dsi->prev = 0; | |
1394 | } | |
1395 | /* memcpy src may not overlap dst, so src doesn't need to be | |
1396 | invalidated either. */ | |
1397 | if (si != NULL) | |
1398 | si->dont_invalidate = true; | |
1399 | ||
1400 | lhs = gimple_call_lhs (stmt); | |
1401 | switch (bcode) | |
1402 | { | |
1403 | case BUILT_IN_MEMCPY: | |
1404 | case BUILT_IN_MEMCPY_CHK: | |
1405 | /* Allow adjust_last_stmt to decrease this memcpy's size. */ | |
1406 | laststmt.stmt = stmt; | |
1407 | laststmt.len = dsi->length; | |
1408 | laststmt.stridx = dsi->idx; | |
1409 | if (lhs) | |
9771b263 | 1410 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] = didx; |
8b57bfeb JJ |
1411 | break; |
1412 | case BUILT_IN_MEMPCPY: | |
1413 | case BUILT_IN_MEMPCPY_CHK: | |
1414 | break; | |
1415 | default: | |
1416 | gcc_unreachable (); | |
1417 | } | |
1418 | } | |
1419 | ||
1420 | /* Handle a strcat-like ({strcat,__strcat_chk}) call. | |
1421 | If strlen of the second argument is known, strlen of the first argument | |
1422 | is increased by the length of the second argument. Furthermore, attempt | |
1423 | to convert it to memcpy/strcpy if the length of the first argument | |
1424 | is known. */ | |
1425 | ||
1426 | static void | |
1427 | handle_builtin_strcat (enum built_in_function bcode, gimple_stmt_iterator *gsi) | |
1428 | { | |
1429 | int idx, didx; | |
1430 | tree src, dst, srclen, dstlen, len, lhs, args, type, fn, objsz, endptr; | |
1431 | bool success; | |
1432 | gimple stmt = gsi_stmt (*gsi); | |
1433 | strinfo si, dsi; | |
1434 | location_t loc; | |
1435 | ||
1436 | src = gimple_call_arg (stmt, 1); | |
1437 | dst = gimple_call_arg (stmt, 0); | |
1438 | lhs = gimple_call_lhs (stmt); | |
1439 | ||
1440 | didx = get_stridx (dst); | |
1441 | if (didx < 0) | |
1442 | return; | |
1443 | ||
1444 | dsi = NULL; | |
1445 | if (didx > 0) | |
1446 | dsi = get_strinfo (didx); | |
1447 | if (dsi == NULL || get_string_length (dsi) == NULL_TREE) | |
1448 | { | |
1449 | /* strcat (p, q) can be transformed into | |
1450 | tmp = p + strlen (p); endptr = strpcpy (tmp, q); | |
1451 | with length endptr - p if we need to compute the length | |
1452 | later on. Don't do this transformation if we don't need | |
1453 | it. */ | |
e79983f4 | 1454 | if (builtin_decl_implicit_p (BUILT_IN_STPCPY) && lhs == NULL_TREE) |
8b57bfeb JJ |
1455 | { |
1456 | if (didx == 0) | |
1457 | { | |
1458 | didx = new_stridx (dst); | |
1459 | if (didx == 0) | |
1460 | return; | |
1461 | } | |
1462 | if (dsi == NULL) | |
1463 | { | |
1464 | dsi = new_strinfo (dst, didx, NULL_TREE); | |
1465 | set_strinfo (didx, dsi); | |
1466 | find_equal_ptrs (dst, didx); | |
1467 | } | |
1468 | else | |
1469 | { | |
1470 | dsi = unshare_strinfo (dsi); | |
1471 | dsi->length = NULL_TREE; | |
1472 | dsi->next = 0; | |
1473 | dsi->endptr = NULL_TREE; | |
1474 | } | |
1475 | dsi->writable = true; | |
1476 | dsi->stmt = stmt; | |
1477 | dsi->dont_invalidate = true; | |
1478 | } | |
1479 | return; | |
1480 | } | |
1481 | ||
1482 | srclen = NULL_TREE; | |
1483 | si = NULL; | |
1484 | idx = get_stridx (src); | |
1485 | if (idx < 0) | |
1486 | srclen = build_int_cst (size_type_node, ~idx); | |
1487 | else if (idx > 0) | |
1488 | { | |
1489 | si = get_strinfo (idx); | |
1490 | if (si != NULL) | |
1491 | srclen = get_string_length (si); | |
1492 | } | |
1493 | ||
1494 | loc = gimple_location (stmt); | |
1495 | dstlen = dsi->length; | |
1496 | endptr = dsi->endptr; | |
1497 | ||
1498 | dsi = unshare_strinfo (dsi); | |
1499 | dsi->endptr = NULL_TREE; | |
1500 | dsi->stmt = NULL; | |
1501 | dsi->writable = true; | |
1502 | ||
1503 | if (srclen != NULL_TREE) | |
1504 | { | |
1505 | dsi->length = fold_build2_loc (loc, PLUS_EXPR, TREE_TYPE (dsi->length), | |
1506 | dsi->length, srclen); | |
1507 | adjust_related_strinfos (loc, dsi, srclen); | |
1508 | dsi->dont_invalidate = true; | |
1509 | } | |
1510 | else | |
1511 | { | |
1512 | dsi->length = NULL; | |
e79983f4 | 1513 | if (lhs == NULL_TREE && builtin_decl_implicit_p (BUILT_IN_STPCPY)) |
8b57bfeb JJ |
1514 | dsi->dont_invalidate = true; |
1515 | } | |
1516 | ||
1517 | if (si != NULL) | |
1518 | /* strcat src may not overlap dst, so src doesn't need to be | |
1519 | invalidated either. */ | |
1520 | si->dont_invalidate = true; | |
1521 | ||
1522 | /* For now. Could remove the lhs from the call and add | |
1523 | lhs = dst; afterwards. */ | |
1524 | if (lhs) | |
1525 | return; | |
1526 | ||
1527 | fn = NULL_TREE; | |
1528 | objsz = NULL_TREE; | |
1529 | switch (bcode) | |
1530 | { | |
1531 | case BUILT_IN_STRCAT: | |
1532 | if (srclen != NULL_TREE) | |
e79983f4 | 1533 | fn = builtin_decl_implicit (BUILT_IN_MEMCPY); |
8b57bfeb | 1534 | else |
e79983f4 | 1535 | fn = builtin_decl_implicit (BUILT_IN_STRCPY); |
8b57bfeb JJ |
1536 | break; |
1537 | case BUILT_IN_STRCAT_CHK: | |
1538 | if (srclen != NULL_TREE) | |
e79983f4 | 1539 | fn = builtin_decl_explicit (BUILT_IN_MEMCPY_CHK); |
8b57bfeb | 1540 | else |
e79983f4 | 1541 | fn = builtin_decl_explicit (BUILT_IN_STRCPY_CHK); |
8b57bfeb JJ |
1542 | objsz = gimple_call_arg (stmt, 2); |
1543 | break; | |
1544 | default: | |
1545 | gcc_unreachable (); | |
1546 | } | |
1547 | ||
1548 | if (fn == NULL_TREE) | |
1549 | return; | |
1550 | ||
1551 | len = NULL_TREE; | |
1552 | if (srclen != NULL_TREE) | |
1553 | { | |
1554 | args = TYPE_ARG_TYPES (TREE_TYPE (fn)); | |
1555 | type = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (args))); | |
1556 | ||
1557 | len = fold_convert_loc (loc, type, unshare_expr (srclen)); | |
1558 | len = fold_build2_loc (loc, PLUS_EXPR, type, len, | |
1559 | build_int_cst (type, 1)); | |
1560 | len = force_gimple_operand_gsi (gsi, len, true, NULL_TREE, true, | |
1561 | GSI_SAME_STMT); | |
1562 | } | |
1563 | if (endptr) | |
1564 | dst = fold_convert_loc (loc, TREE_TYPE (dst), unshare_expr (endptr)); | |
1565 | else | |
1566 | dst = fold_build2_loc (loc, POINTER_PLUS_EXPR, | |
1567 | TREE_TYPE (dst), unshare_expr (dst), | |
1568 | fold_convert_loc (loc, sizetype, | |
1569 | unshare_expr (dstlen))); | |
1570 | dst = force_gimple_operand_gsi (gsi, dst, true, NULL_TREE, true, | |
1571 | GSI_SAME_STMT); | |
1572 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1573 | { | |
1574 | fprintf (dump_file, "Optimizing: "); | |
1575 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1576 | } | |
1577 | if (srclen != NULL_TREE) | |
1578 | success = update_gimple_call (gsi, fn, 3 + (objsz != NULL_TREE), | |
1579 | dst, src, len, objsz); | |
1580 | else | |
1581 | success = update_gimple_call (gsi, fn, 2 + (objsz != NULL_TREE), | |
1582 | dst, src, objsz); | |
1583 | if (success) | |
1584 | { | |
1585 | stmt = gsi_stmt (*gsi); | |
1586 | update_stmt (stmt); | |
1587 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1588 | { | |
1589 | fprintf (dump_file, "into: "); | |
1590 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1591 | } | |
1592 | /* If srclen == NULL, note that current string length can be | |
1593 | computed by transforming this strcpy into stpcpy. */ | |
1594 | if (srclen == NULL_TREE && dsi->dont_invalidate) | |
1595 | dsi->stmt = stmt; | |
1596 | adjust_last_stmt (dsi, stmt, true); | |
1597 | if (srclen != NULL_TREE) | |
1598 | { | |
1599 | laststmt.stmt = stmt; | |
1600 | laststmt.len = srclen; | |
1601 | laststmt.stridx = dsi->idx; | |
1602 | } | |
1603 | } | |
1604 | else if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1605 | fprintf (dump_file, "not possible.\n"); | |
1606 | } | |
1607 | ||
1608 | /* Handle a POINTER_PLUS_EXPR statement. | |
1609 | For p = "abcd" + 2; compute associated length, or if | |
1610 | p = q + off is pointing to a '\0' character of a string, call | |
1611 | zero_length_string on it. */ | |
1612 | ||
1613 | static void | |
1614 | handle_pointer_plus (gimple_stmt_iterator *gsi) | |
1615 | { | |
1616 | gimple stmt = gsi_stmt (*gsi); | |
1617 | tree lhs = gimple_assign_lhs (stmt), off; | |
1618 | int idx = get_stridx (gimple_assign_rhs1 (stmt)); | |
1619 | strinfo si, zsi; | |
1620 | ||
1621 | if (idx == 0) | |
1622 | return; | |
1623 | ||
1624 | if (idx < 0) | |
1625 | { | |
1626 | tree off = gimple_assign_rhs2 (stmt); | |
cc269bb6 | 1627 | if (tree_fits_uhwi_p (off) |
7d362f6c | 1628 | && tree_to_uhwi (off) <= (unsigned HOST_WIDE_INT) ~idx) |
9771b263 | 1629 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] |
ae7e9ddd | 1630 | = ~(~idx - (int) tree_to_uhwi (off)); |
8b57bfeb JJ |
1631 | return; |
1632 | } | |
1633 | ||
1634 | si = get_strinfo (idx); | |
1635 | if (si == NULL || si->length == NULL_TREE) | |
1636 | return; | |
1637 | ||
1638 | off = gimple_assign_rhs2 (stmt); | |
1639 | zsi = NULL; | |
1640 | if (operand_equal_p (si->length, off, 0)) | |
1641 | zsi = zero_length_string (lhs, si); | |
1642 | else if (TREE_CODE (off) == SSA_NAME) | |
1643 | { | |
1644 | gimple def_stmt = SSA_NAME_DEF_STMT (off); | |
1645 | if (gimple_assign_single_p (def_stmt) | |
1646 | && operand_equal_p (si->length, gimple_assign_rhs1 (def_stmt), 0)) | |
1647 | zsi = zero_length_string (lhs, si); | |
1648 | } | |
1649 | if (zsi != NULL | |
1650 | && si->endptr != NULL_TREE | |
1651 | && si->endptr != lhs | |
1652 | && TREE_CODE (si->endptr) == SSA_NAME) | |
1653 | { | |
1654 | enum tree_code rhs_code | |
1655 | = useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (si->endptr)) | |
1656 | ? SSA_NAME : NOP_EXPR; | |
1657 | gimple_assign_set_rhs_with_ops (gsi, rhs_code, si->endptr, NULL_TREE); | |
1658 | gcc_assert (gsi_stmt (*gsi) == stmt); | |
1659 | update_stmt (stmt); | |
1660 | } | |
1661 | } | |
1662 | ||
1663 | /* Handle a single character store. */ | |
1664 | ||
1665 | static bool | |
1666 | handle_char_store (gimple_stmt_iterator *gsi) | |
1667 | { | |
1668 | int idx = -1; | |
1669 | strinfo si = NULL; | |
1670 | gimple stmt = gsi_stmt (*gsi); | |
1671 | tree ssaname = NULL_TREE, lhs = gimple_assign_lhs (stmt); | |
1672 | ||
1673 | if (TREE_CODE (lhs) == MEM_REF | |
1674 | && TREE_CODE (TREE_OPERAND (lhs, 0)) == SSA_NAME) | |
1675 | { | |
1676 | if (integer_zerop (TREE_OPERAND (lhs, 1))) | |
1677 | { | |
1678 | ssaname = TREE_OPERAND (lhs, 0); | |
1679 | idx = get_stridx (ssaname); | |
1680 | } | |
1681 | } | |
1682 | else | |
1683 | idx = get_addr_stridx (lhs); | |
1684 | ||
1685 | if (idx > 0) | |
1686 | { | |
1687 | si = get_strinfo (idx); | |
1688 | if (si != NULL && si->length != NULL_TREE && integer_zerop (si->length)) | |
1689 | { | |
1690 | if (initializer_zerop (gimple_assign_rhs1 (stmt))) | |
1691 | { | |
1692 | /* When storing '\0', the store can be removed | |
1693 | if we know it has been stored in the current function. */ | |
1694 | if (!stmt_could_throw_p (stmt) && si->writable) | |
1695 | { | |
1696 | unlink_stmt_vdef (stmt); | |
1697 | release_defs (stmt); | |
1698 | gsi_remove (gsi, true); | |
1699 | return false; | |
1700 | } | |
1701 | else | |
1702 | { | |
1703 | si->writable = true; | |
5b115c1f MP |
1704 | gsi_next (gsi); |
1705 | return false; | |
8b57bfeb JJ |
1706 | } |
1707 | } | |
1708 | else | |
1709 | /* Otherwise this statement overwrites the '\0' with | |
1710 | something, if the previous stmt was a memcpy, | |
1711 | its length may be decreased. */ | |
1712 | adjust_last_stmt (si, stmt, false); | |
1713 | } | |
3a60f32b | 1714 | else if (si != NULL && integer_zerop (gimple_assign_rhs1 (stmt))) |
8b57bfeb JJ |
1715 | { |
1716 | si = unshare_strinfo (si); | |
1717 | si->length = build_int_cst (size_type_node, 0); | |
1718 | si->endptr = NULL; | |
1719 | si->prev = 0; | |
1720 | si->next = 0; | |
1721 | si->stmt = NULL; | |
1722 | si->first = 0; | |
1723 | si->writable = true; | |
1724 | if (ssaname && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ssaname)) | |
1725 | si->endptr = ssaname; | |
1726 | si->dont_invalidate = true; | |
1727 | } | |
5b115c1f MP |
1728 | /* If si->length is non-zero constant, we aren't overwriting '\0', |
1729 | and if we aren't storing '\0', we know that the length of the | |
1730 | string and any other zero terminated string in memory remains | |
1731 | the same. In that case we move to the next gimple statement and | |
1732 | return to signal the caller that it shouldn't invalidate anything. | |
1733 | ||
1734 | This is benefical for cases like: | |
1735 | ||
1736 | char p[20]; | |
1737 | void foo (char *q) | |
1738 | { | |
1739 | strcpy (p, "foobar"); | |
1740 | size_t len = strlen (p); // This can be optimized into 6 | |
1741 | size_t len2 = strlen (q); // This has to be computed | |
1742 | p[0] = 'X'; | |
1743 | size_t len3 = strlen (p); // This can be optimized into 6 | |
1744 | size_t len4 = strlen (q); // This can be optimized into len2 | |
1745 | bar (len, len2, len3, len4); | |
1746 | } | |
1747 | */ | |
1748 | else if (si != NULL && si->length != NULL_TREE | |
1749 | && TREE_CODE (si->length) == INTEGER_CST | |
1750 | && integer_nonzerop (gimple_assign_rhs1 (stmt))) | |
1751 | { | |
1752 | gsi_next (gsi); | |
1753 | return false; | |
1754 | } | |
8b57bfeb JJ |
1755 | } |
1756 | else if (idx == 0 && initializer_zerop (gimple_assign_rhs1 (stmt))) | |
1757 | { | |
1758 | if (ssaname) | |
1759 | { | |
1760 | si = zero_length_string (ssaname, NULL); | |
1761 | if (si != NULL) | |
1762 | si->dont_invalidate = true; | |
1763 | } | |
1764 | else | |
1765 | { | |
1766 | int idx = new_addr_stridx (lhs); | |
1767 | if (idx != 0) | |
1768 | { | |
1769 | si = new_strinfo (build_fold_addr_expr (lhs), idx, | |
1770 | build_int_cst (size_type_node, 0)); | |
1771 | set_strinfo (idx, si); | |
1772 | si->dont_invalidate = true; | |
1773 | } | |
1774 | } | |
1775 | if (si != NULL) | |
1776 | si->writable = true; | |
1777 | } | |
198fe1bf JJ |
1778 | else if (idx == 0 |
1779 | && TREE_CODE (gimple_assign_rhs1 (stmt)) == STRING_CST | |
1780 | && ssaname == NULL_TREE | |
1781 | && TREE_CODE (TREE_TYPE (lhs)) == ARRAY_TYPE) | |
1782 | { | |
1783 | size_t l = strlen (TREE_STRING_POINTER (gimple_assign_rhs1 (stmt))); | |
1784 | HOST_WIDE_INT a = int_size_in_bytes (TREE_TYPE (lhs)); | |
1785 | if (a > 0 && (unsigned HOST_WIDE_INT) a > l) | |
1786 | { | |
1787 | int idx = new_addr_stridx (lhs); | |
1788 | if (idx != 0) | |
1789 | { | |
1790 | si = new_strinfo (build_fold_addr_expr (lhs), idx, | |
1791 | build_int_cst (size_type_node, l)); | |
1792 | set_strinfo (idx, si); | |
1793 | si->dont_invalidate = true; | |
1794 | } | |
1795 | } | |
1796 | } | |
8b57bfeb JJ |
1797 | |
1798 | if (si != NULL && initializer_zerop (gimple_assign_rhs1 (stmt))) | |
1799 | { | |
1800 | /* Allow adjust_last_stmt to remove it if the stored '\0' | |
1801 | is immediately overwritten. */ | |
1802 | laststmt.stmt = stmt; | |
1803 | laststmt.len = build_int_cst (size_type_node, 1); | |
1804 | laststmt.stridx = si->idx; | |
1805 | } | |
1806 | return true; | |
1807 | } | |
1808 | ||
1809 | /* Attempt to optimize a single statement at *GSI using string length | |
1810 | knowledge. */ | |
1811 | ||
1812 | static bool | |
1813 | strlen_optimize_stmt (gimple_stmt_iterator *gsi) | |
1814 | { | |
1815 | gimple stmt = gsi_stmt (*gsi); | |
1816 | ||
1817 | if (is_gimple_call (stmt)) | |
1818 | { | |
1819 | tree callee = gimple_call_fndecl (stmt); | |
3626621a | 1820 | if (gimple_call_builtin_p (stmt, BUILT_IN_NORMAL)) |
8b57bfeb JJ |
1821 | switch (DECL_FUNCTION_CODE (callee)) |
1822 | { | |
1823 | case BUILT_IN_STRLEN: | |
1824 | handle_builtin_strlen (gsi); | |
1825 | break; | |
1826 | case BUILT_IN_STRCHR: | |
1827 | handle_builtin_strchr (gsi); | |
1828 | break; | |
1829 | case BUILT_IN_STRCPY: | |
1830 | case BUILT_IN_STRCPY_CHK: | |
1831 | case BUILT_IN_STPCPY: | |
1832 | case BUILT_IN_STPCPY_CHK: | |
1833 | handle_builtin_strcpy (DECL_FUNCTION_CODE (callee), gsi); | |
1834 | break; | |
1835 | case BUILT_IN_MEMCPY: | |
1836 | case BUILT_IN_MEMCPY_CHK: | |
1837 | case BUILT_IN_MEMPCPY: | |
1838 | case BUILT_IN_MEMPCPY_CHK: | |
1839 | handle_builtin_memcpy (DECL_FUNCTION_CODE (callee), gsi); | |
1840 | break; | |
1841 | case BUILT_IN_STRCAT: | |
1842 | case BUILT_IN_STRCAT_CHK: | |
1843 | handle_builtin_strcat (DECL_FUNCTION_CODE (callee), gsi); | |
1844 | break; | |
1845 | default: | |
1846 | break; | |
1847 | } | |
1848 | } | |
1849 | else if (is_gimple_assign (stmt)) | |
1850 | { | |
1851 | tree lhs = gimple_assign_lhs (stmt); | |
1852 | ||
1853 | if (TREE_CODE (lhs) == SSA_NAME && POINTER_TYPE_P (TREE_TYPE (lhs))) | |
1854 | { | |
1855 | if (gimple_assign_single_p (stmt) | |
1856 | || (gimple_assign_cast_p (stmt) | |
1857 | && POINTER_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (stmt))))) | |
1858 | { | |
1859 | int idx = get_stridx (gimple_assign_rhs1 (stmt)); | |
9771b263 | 1860 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] = idx; |
8b57bfeb JJ |
1861 | } |
1862 | else if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR) | |
1863 | handle_pointer_plus (gsi); | |
1864 | } | |
1865 | else if (TREE_CODE (lhs) != SSA_NAME && !TREE_SIDE_EFFECTS (lhs)) | |
1866 | { | |
1867 | tree type = TREE_TYPE (lhs); | |
1868 | if (TREE_CODE (type) == ARRAY_TYPE) | |
1869 | type = TREE_TYPE (type); | |
1870 | if (TREE_CODE (type) == INTEGER_TYPE | |
1871 | && TYPE_MODE (type) == TYPE_MODE (char_type_node) | |
1872 | && TYPE_PRECISION (type) == TYPE_PRECISION (char_type_node)) | |
1873 | { | |
1874 | if (! handle_char_store (gsi)) | |
1875 | return false; | |
1876 | } | |
1877 | } | |
1878 | } | |
1879 | ||
1880 | if (gimple_vdef (stmt)) | |
1881 | maybe_invalidate (stmt); | |
1882 | return true; | |
1883 | } | |
1884 | ||
1885 | /* Recursively call maybe_invalidate on stmts that might be executed | |
1886 | in between dombb and current bb and that contain a vdef. Stop when | |
1887 | *count stmts are inspected, or if the whole strinfo vector has | |
1888 | been invalidated. */ | |
1889 | ||
1890 | static void | |
1891 | do_invalidate (basic_block dombb, gimple phi, bitmap visited, int *count) | |
1892 | { | |
1893 | unsigned int i, n = gimple_phi_num_args (phi); | |
1894 | ||
1895 | for (i = 0; i < n; i++) | |
1896 | { | |
1897 | tree vuse = gimple_phi_arg_def (phi, i); | |
1898 | gimple stmt = SSA_NAME_DEF_STMT (vuse); | |
1899 | basic_block bb = gimple_bb (stmt); | |
1900 | if (bb == NULL | |
1901 | || bb == dombb | |
1902 | || !bitmap_set_bit (visited, bb->index) | |
1903 | || !dominated_by_p (CDI_DOMINATORS, bb, dombb)) | |
1904 | continue; | |
1905 | while (1) | |
1906 | { | |
1907 | if (gimple_code (stmt) == GIMPLE_PHI) | |
1908 | { | |
1909 | do_invalidate (dombb, stmt, visited, count); | |
1910 | if (*count == 0) | |
1911 | return; | |
1912 | break; | |
1913 | } | |
1914 | if (--*count == 0) | |
1915 | return; | |
1916 | if (!maybe_invalidate (stmt)) | |
1917 | { | |
1918 | *count = 0; | |
1919 | return; | |
1920 | } | |
1921 | vuse = gimple_vuse (stmt); | |
1922 | stmt = SSA_NAME_DEF_STMT (vuse); | |
1923 | if (gimple_bb (stmt) != bb) | |
1924 | { | |
1925 | bb = gimple_bb (stmt); | |
1926 | if (bb == NULL | |
1927 | || bb == dombb | |
1928 | || !bitmap_set_bit (visited, bb->index) | |
1929 | || !dominated_by_p (CDI_DOMINATORS, bb, dombb)) | |
1930 | break; | |
1931 | } | |
1932 | } | |
1933 | } | |
1934 | } | |
1935 | ||
4d9192b5 TS |
1936 | class strlen_dom_walker : public dom_walker |
1937 | { | |
1938 | public: | |
1939 | strlen_dom_walker (cdi_direction direction) : dom_walker (direction) {} | |
1940 | ||
1941 | virtual void before_dom_children (basic_block); | |
1942 | virtual void after_dom_children (basic_block); | |
1943 | }; | |
1944 | ||
8b57bfeb JJ |
1945 | /* Callback for walk_dominator_tree. Attempt to optimize various |
1946 | string ops by remembering string lenths pointed by pointer SSA_NAMEs. */ | |
1947 | ||
4d9192b5 TS |
1948 | void |
1949 | strlen_dom_walker::before_dom_children (basic_block bb) | |
8b57bfeb JJ |
1950 | { |
1951 | gimple_stmt_iterator gsi; | |
1952 | basic_block dombb = get_immediate_dominator (CDI_DOMINATORS, bb); | |
1953 | ||
1954 | if (dombb == NULL) | |
1955 | stridx_to_strinfo = NULL; | |
1956 | else | |
1957 | { | |
9771b263 | 1958 | stridx_to_strinfo = ((vec<strinfo, va_heap, vl_embed> *) dombb->aux); |
8b57bfeb JJ |
1959 | if (stridx_to_strinfo) |
1960 | { | |
1961 | for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
1962 | { | |
1963 | gimple phi = gsi_stmt (gsi); | |
ea057359 | 1964 | if (virtual_operand_p (gimple_phi_result (phi))) |
8b57bfeb JJ |
1965 | { |
1966 | bitmap visited = BITMAP_ALLOC (NULL); | |
1967 | int count_vdef = 100; | |
1968 | do_invalidate (dombb, phi, visited, &count_vdef); | |
1969 | BITMAP_FREE (visited); | |
8b29fd4e JJ |
1970 | if (count_vdef == 0) |
1971 | { | |
1972 | /* If there were too many vdefs in between immediate | |
1973 | dominator and current bb, invalidate everything. | |
1974 | If stridx_to_strinfo has been unshared, we need | |
1975 | to free it, otherwise just set it to NULL. */ | |
1976 | if (!strinfo_shared ()) | |
1977 | { | |
1978 | unsigned int i; | |
1979 | strinfo si; | |
1980 | ||
1981 | for (i = 1; | |
1982 | vec_safe_iterate (stridx_to_strinfo, i, &si); | |
1983 | ++i) | |
1984 | { | |
1985 | free_strinfo (si); | |
1986 | (*stridx_to_strinfo)[i] = NULL; | |
1987 | } | |
1988 | } | |
1989 | else | |
1990 | stridx_to_strinfo = NULL; | |
1991 | } | |
8b57bfeb JJ |
1992 | break; |
1993 | } | |
1994 | } | |
1995 | } | |
1996 | } | |
1997 | ||
1998 | /* If all PHI arguments have the same string index, the PHI result | |
1999 | has it as well. */ | |
2000 | for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
2001 | { | |
2002 | gimple phi = gsi_stmt (gsi); | |
2003 | tree result = gimple_phi_result (phi); | |
ea057359 | 2004 | if (!virtual_operand_p (result) && POINTER_TYPE_P (TREE_TYPE (result))) |
8b57bfeb JJ |
2005 | { |
2006 | int idx = get_stridx (gimple_phi_arg_def (phi, 0)); | |
2007 | if (idx != 0) | |
2008 | { | |
2009 | unsigned int i, n = gimple_phi_num_args (phi); | |
2010 | for (i = 1; i < n; i++) | |
2011 | if (idx != get_stridx (gimple_phi_arg_def (phi, i))) | |
2012 | break; | |
2013 | if (i == n) | |
9771b263 | 2014 | ssa_ver_to_stridx[SSA_NAME_VERSION (result)] = idx; |
8b57bfeb JJ |
2015 | } |
2016 | } | |
2017 | } | |
2018 | ||
2019 | /* Attempt to optimize individual statements. */ | |
2020 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); ) | |
2021 | if (strlen_optimize_stmt (&gsi)) | |
2022 | gsi_next (&gsi); | |
2023 | ||
2024 | bb->aux = stridx_to_strinfo; | |
9771b263 DN |
2025 | if (vec_safe_length (stridx_to_strinfo) && !strinfo_shared ()) |
2026 | (*stridx_to_strinfo)[0] = (strinfo) bb; | |
8b57bfeb JJ |
2027 | } |
2028 | ||
2029 | /* Callback for walk_dominator_tree. Free strinfo vector if it is | |
2030 | owned by the current bb, clear bb->aux. */ | |
2031 | ||
4d9192b5 TS |
2032 | void |
2033 | strlen_dom_walker::after_dom_children (basic_block bb) | |
8b57bfeb JJ |
2034 | { |
2035 | if (bb->aux) | |
2036 | { | |
9771b263 DN |
2037 | stridx_to_strinfo = ((vec<strinfo, va_heap, vl_embed> *) bb->aux); |
2038 | if (vec_safe_length (stridx_to_strinfo) | |
2039 | && (*stridx_to_strinfo)[0] == (strinfo) bb) | |
8b57bfeb JJ |
2040 | { |
2041 | unsigned int i; | |
2042 | strinfo si; | |
2043 | ||
9771b263 | 2044 | for (i = 1; vec_safe_iterate (stridx_to_strinfo, i, &si); ++i) |
8b57bfeb | 2045 | free_strinfo (si); |
9771b263 | 2046 | vec_free (stridx_to_strinfo); |
8b57bfeb JJ |
2047 | } |
2048 | bb->aux = NULL; | |
2049 | } | |
2050 | } | |
2051 | ||
2052 | /* Main entry point. */ | |
2053 | ||
2054 | static unsigned int | |
2055 | tree_ssa_strlen (void) | |
2056 | { | |
9771b263 | 2057 | ssa_ver_to_stridx.safe_grow_cleared (num_ssa_names); |
8b57bfeb JJ |
2058 | max_stridx = 1; |
2059 | strinfo_pool = create_alloc_pool ("strinfo_struct pool", | |
2060 | sizeof (struct strinfo_struct), 64); | |
2061 | ||
2062 | calculate_dominance_info (CDI_DOMINATORS); | |
2063 | ||
2064 | /* String length optimization is implemented as a walk of the dominator | |
2065 | tree and a forward walk of statements within each block. */ | |
4d9192b5 | 2066 | strlen_dom_walker (CDI_DOMINATORS).walk (cfun->cfg->x_entry_block_ptr); |
8b57bfeb | 2067 | |
9771b263 | 2068 | ssa_ver_to_stridx.release (); |
8b57bfeb | 2069 | free_alloc_pool (strinfo_pool); |
4a8fb1a1 | 2070 | if (decl_to_stridxlist_htab.is_created ()) |
8b57bfeb JJ |
2071 | { |
2072 | obstack_free (&stridx_obstack, NULL); | |
4a8fb1a1 | 2073 | decl_to_stridxlist_htab.dispose (); |
8b57bfeb JJ |
2074 | } |
2075 | laststmt.stmt = NULL; | |
2076 | laststmt.len = NULL_TREE; | |
2077 | laststmt.stridx = 0; | |
2078 | ||
2079 | return 0; | |
2080 | } | |
2081 | ||
2082 | static bool | |
2083 | gate_strlen (void) | |
2084 | { | |
2085 | return flag_optimize_strlen != 0; | |
2086 | } | |
2087 | ||
27a4cd48 DM |
2088 | namespace { |
2089 | ||
2090 | const pass_data pass_data_strlen = | |
8b57bfeb | 2091 | { |
27a4cd48 DM |
2092 | GIMPLE_PASS, /* type */ |
2093 | "strlen", /* name */ | |
2094 | OPTGROUP_NONE, /* optinfo_flags */ | |
2095 | true, /* has_gate */ | |
2096 | true, /* has_execute */ | |
2097 | TV_TREE_STRLEN, /* tv_id */ | |
2098 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
2099 | 0, /* properties_provided */ | |
2100 | 0, /* properties_destroyed */ | |
2101 | 0, /* todo_flags_start */ | |
2102 | TODO_verify_ssa, /* todo_flags_finish */ | |
8b57bfeb | 2103 | }; |
27a4cd48 DM |
2104 | |
2105 | class pass_strlen : public gimple_opt_pass | |
2106 | { | |
2107 | public: | |
c3284718 RS |
2108 | pass_strlen (gcc::context *ctxt) |
2109 | : gimple_opt_pass (pass_data_strlen, ctxt) | |
27a4cd48 DM |
2110 | {} |
2111 | ||
2112 | /* opt_pass methods: */ | |
2113 | bool gate () { return gate_strlen (); } | |
2114 | unsigned int execute () { return tree_ssa_strlen (); } | |
2115 | ||
2116 | }; // class pass_strlen | |
2117 | ||
2118 | } // anon namespace | |
2119 | ||
2120 | gimple_opt_pass * | |
2121 | make_pass_strlen (gcc::context *ctxt) | |
2122 | { | |
2123 | return new pass_strlen (ctxt); | |
2124 | } |