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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" |
45b0be94 | 27 | #include "gimplify.h" |
442b4905 AM |
28 | #include "gimple-ssa.h" |
29 | #include "tree-phinodes.h" | |
30 | #include "ssa-iterators.h" | |
31 | #include "tree-ssanames.h" | |
32 | #include "tree-dfa.h" | |
8b57bfeb JJ |
33 | #include "tree-pass.h" |
34 | #include "domwalk.h" | |
35 | #include "alloc-pool.h" | |
36 | #include "tree-ssa-propagate.h" | |
37 | #include "gimple-pretty-print.h" | |
38 | #include "params.h" | |
b3c3685a | 39 | #include "expr.h" |
8b57bfeb JJ |
40 | |
41 | /* A vector indexed by SSA_NAME_VERSION. 0 means unknown, positive value | |
42 | is an index into strinfo vector, negative value stands for | |
43 | string length of a string literal (~strlen). */ | |
9771b263 | 44 | static vec<int> ssa_ver_to_stridx; |
8b57bfeb JJ |
45 | |
46 | /* Number of currently active string indexes plus one. */ | |
47 | static int max_stridx; | |
48 | ||
49 | /* String information record. */ | |
50 | typedef struct strinfo_struct | |
51 | { | |
52 | /* String length of this string. */ | |
53 | tree length; | |
54 | /* Any of the corresponding pointers for querying alias oracle. */ | |
55 | tree ptr; | |
56 | /* Statement for delayed length computation. */ | |
57 | gimple stmt; | |
58 | /* Pointer to '\0' if known, if NULL, it can be computed as | |
59 | ptr + length. */ | |
60 | tree endptr; | |
61 | /* Reference count. Any changes to strinfo entry possibly shared | |
62 | with dominating basic blocks need unshare_strinfo first, except | |
63 | for dont_invalidate which affects only the immediately next | |
64 | maybe_invalidate. */ | |
65 | int refcount; | |
66 | /* Copy of index. get_strinfo (si->idx) should return si; */ | |
67 | int idx; | |
68 | /* These 3 fields are for chaining related string pointers together. | |
69 | E.g. for | |
70 | bl = strlen (b); dl = strlen (d); strcpy (a, b); c = a + bl; | |
71 | strcpy (c, d); e = c + dl; | |
72 | strinfo(a) -> strinfo(c) -> strinfo(e) | |
73 | All have ->first field equal to strinfo(a)->idx and are doubly | |
74 | chained through prev/next fields. The later strinfos are required | |
75 | to point into the same string with zero or more bytes after | |
76 | the previous pointer and all bytes in between the two pointers | |
77 | must be non-zero. Functions like strcpy or memcpy are supposed | |
78 | to adjust all previous strinfo lengths, but not following strinfo | |
79 | lengths (those are uncertain, usually invalidated during | |
80 | maybe_invalidate, except when the alias oracle knows better). | |
81 | Functions like strcat on the other side adjust the whole | |
82 | related strinfo chain. | |
83 | They are updated lazily, so to use the chain the same first fields | |
84 | and si->prev->next == si->idx needs to be verified. */ | |
85 | int first; | |
86 | int next; | |
87 | int prev; | |
88 | /* A flag whether the string is known to be written in the current | |
89 | function. */ | |
90 | bool writable; | |
91 | /* A flag for the next maybe_invalidate that this strinfo shouldn't | |
92 | be invalidated. Always cleared by maybe_invalidate. */ | |
93 | bool dont_invalidate; | |
94 | } *strinfo; | |
8b57bfeb JJ |
95 | |
96 | /* Pool for allocating strinfo_struct entries. */ | |
97 | static alloc_pool strinfo_pool; | |
98 | ||
99 | /* Vector mapping positive string indexes to strinfo, for the | |
100 | current basic block. The first pointer in the vector is special, | |
101 | it is either NULL, meaning the vector isn't shared, or it is | |
102 | a basic block pointer to the owner basic_block if shared. | |
103 | If some other bb wants to modify the vector, the vector needs | |
104 | to be unshared first, and only the owner bb is supposed to free it. */ | |
9771b263 | 105 | static vec<strinfo, va_heap, vl_embed> *stridx_to_strinfo; |
8b57bfeb JJ |
106 | |
107 | /* One OFFSET->IDX mapping. */ | |
108 | struct stridxlist | |
109 | { | |
110 | struct stridxlist *next; | |
111 | HOST_WIDE_INT offset; | |
112 | int idx; | |
113 | }; | |
114 | ||
115 | /* Hash table entry, mapping a DECL to a chain of OFFSET->IDX mappings. */ | |
116 | struct decl_stridxlist_map | |
117 | { | |
118 | struct tree_map_base base; | |
119 | struct stridxlist list; | |
120 | }; | |
121 | ||
4a8fb1a1 LC |
122 | /* stridxlist hashtable helpers. */ |
123 | ||
124 | struct stridxlist_hasher : typed_noop_remove <decl_stridxlist_map> | |
125 | { | |
126 | typedef decl_stridxlist_map value_type; | |
127 | typedef decl_stridxlist_map compare_type; | |
128 | static inline hashval_t hash (const value_type *); | |
129 | static inline bool equal (const value_type *, const compare_type *); | |
130 | }; | |
131 | ||
132 | /* Hash a from tree in a decl_stridxlist_map. */ | |
133 | ||
134 | inline hashval_t | |
135 | stridxlist_hasher::hash (const value_type *item) | |
136 | { | |
137 | return DECL_UID (item->base.from); | |
138 | } | |
139 | ||
140 | inline bool | |
141 | stridxlist_hasher::equal (const value_type *v, const compare_type *c) | |
142 | { | |
143 | return tree_map_base_eq (&v->base, &c->base); | |
144 | } | |
145 | ||
8b57bfeb JJ |
146 | /* Hash table for mapping decls to a chained list of offset -> idx |
147 | mappings. */ | |
4a8fb1a1 | 148 | static hash_table <stridxlist_hasher> decl_to_stridxlist_htab; |
8b57bfeb JJ |
149 | |
150 | /* Obstack for struct stridxlist and struct decl_stridxlist_map. */ | |
151 | static struct obstack stridx_obstack; | |
152 | ||
153 | /* Last memcpy statement if it could be adjusted if the trailing | |
154 | '\0' written is immediately overwritten, or | |
155 | *x = '\0' store that could be removed if it is immediately overwritten. */ | |
156 | struct laststmt_struct | |
157 | { | |
158 | gimple stmt; | |
159 | tree len; | |
160 | int stridx; | |
161 | } laststmt; | |
162 | ||
8b57bfeb JJ |
163 | /* Helper function for get_stridx. */ |
164 | ||
165 | static int | |
166 | get_addr_stridx (tree exp) | |
167 | { | |
168 | HOST_WIDE_INT off; | |
169 | struct decl_stridxlist_map ent, *e; | |
170 | struct stridxlist *list; | |
171 | tree base; | |
172 | ||
4a8fb1a1 | 173 | if (!decl_to_stridxlist_htab.is_created ()) |
8b57bfeb JJ |
174 | return 0; |
175 | ||
176 | base = get_addr_base_and_unit_offset (exp, &off); | |
177 | if (base == NULL || !DECL_P (base)) | |
178 | return 0; | |
179 | ||
180 | ent.base.from = base; | |
4a8fb1a1 | 181 | e = decl_to_stridxlist_htab.find_with_hash (&ent, DECL_UID (base)); |
8b57bfeb JJ |
182 | if (e == NULL) |
183 | return 0; | |
184 | ||
185 | list = &e->list; | |
186 | do | |
187 | { | |
188 | if (list->offset == off) | |
189 | return list->idx; | |
190 | list = list->next; | |
191 | } | |
192 | while (list); | |
193 | return 0; | |
194 | } | |
195 | ||
196 | /* Return string index for EXP. */ | |
197 | ||
198 | static int | |
199 | get_stridx (tree exp) | |
200 | { | |
b3c3685a | 201 | tree s, o; |
8b57bfeb JJ |
202 | |
203 | if (TREE_CODE (exp) == SSA_NAME) | |
9771b263 | 204 | return ssa_ver_to_stridx[SSA_NAME_VERSION (exp)]; |
8b57bfeb JJ |
205 | |
206 | if (TREE_CODE (exp) == ADDR_EXPR) | |
207 | { | |
208 | int idx = get_addr_stridx (TREE_OPERAND (exp, 0)); | |
209 | if (idx != 0) | |
210 | return idx; | |
211 | } | |
212 | ||
b3c3685a JJ |
213 | s = string_constant (exp, &o); |
214 | if (s != NULL_TREE | |
215 | && (o == NULL_TREE || host_integerp (o, 0)) | |
216 | && TREE_STRING_LENGTH (s) > 0) | |
8b57bfeb | 217 | { |
b3c3685a JJ |
218 | HOST_WIDE_INT offset = o ? tree_low_cst (o, 0) : 0; |
219 | const char *p = TREE_STRING_POINTER (s); | |
220 | int max = TREE_STRING_LENGTH (s) - 1; | |
221 | ||
222 | if (p[max] == '\0' && offset >= 0 && offset <= max) | |
223 | return ~(int) strlen (p + offset); | |
8b57bfeb JJ |
224 | } |
225 | return 0; | |
226 | } | |
227 | ||
228 | /* Return true if strinfo vector is shared with the immediate dominator. */ | |
229 | ||
230 | static inline bool | |
231 | strinfo_shared (void) | |
232 | { | |
9771b263 DN |
233 | return vec_safe_length (stridx_to_strinfo) |
234 | && (*stridx_to_strinfo)[0] != NULL; | |
8b57bfeb JJ |
235 | } |
236 | ||
237 | /* Unshare strinfo vector that is shared with the immediate dominator. */ | |
238 | ||
239 | static void | |
240 | unshare_strinfo_vec (void) | |
241 | { | |
242 | strinfo si; | |
243 | unsigned int i = 0; | |
244 | ||
245 | gcc_assert (strinfo_shared ()); | |
9771b263 DN |
246 | stridx_to_strinfo = vec_safe_copy (stridx_to_strinfo); |
247 | for (i = 1; vec_safe_iterate (stridx_to_strinfo, i, &si); ++i) | |
8b57bfeb JJ |
248 | if (si != NULL) |
249 | si->refcount++; | |
9771b263 | 250 | (*stridx_to_strinfo)[0] = NULL; |
8b57bfeb JJ |
251 | } |
252 | ||
253 | /* Attempt to create a string index for exp, ADDR_EXPR's operand. | |
254 | Return a pointer to the location where the string index can | |
255 | be stored (if 0) or is stored, or NULL if this can't be tracked. */ | |
256 | ||
257 | static int * | |
258 | addr_stridxptr (tree exp) | |
259 | { | |
4a8fb1a1 | 260 | decl_stridxlist_map **slot; |
8b57bfeb JJ |
261 | struct decl_stridxlist_map ent; |
262 | struct stridxlist *list; | |
263 | HOST_WIDE_INT off; | |
264 | ||
265 | tree base = get_addr_base_and_unit_offset (exp, &off); | |
266 | if (base == NULL_TREE || !DECL_P (base)) | |
267 | return NULL; | |
268 | ||
4a8fb1a1 | 269 | if (!decl_to_stridxlist_htab.is_created ()) |
8b57bfeb | 270 | { |
4a8fb1a1 | 271 | decl_to_stridxlist_htab.create (64); |
8b57bfeb JJ |
272 | gcc_obstack_init (&stridx_obstack); |
273 | } | |
274 | ent.base.from = base; | |
4a8fb1a1 LC |
275 | slot = decl_to_stridxlist_htab.find_slot_with_hash (&ent, DECL_UID (base), |
276 | INSERT); | |
8b57bfeb JJ |
277 | if (*slot) |
278 | { | |
279 | int i; | |
4a8fb1a1 | 280 | list = &(*slot)->list; |
8b57bfeb JJ |
281 | for (i = 0; i < 16; i++) |
282 | { | |
283 | if (list->offset == off) | |
284 | return &list->idx; | |
285 | if (list->next == NULL) | |
286 | break; | |
287 | } | |
288 | if (i == 16) | |
289 | return NULL; | |
290 | list->next = XOBNEW (&stridx_obstack, struct stridxlist); | |
291 | list = list->next; | |
292 | } | |
293 | else | |
294 | { | |
295 | struct decl_stridxlist_map *e | |
296 | = XOBNEW (&stridx_obstack, struct decl_stridxlist_map); | |
297 | e->base.from = base; | |
4a8fb1a1 | 298 | *slot = e; |
8b57bfeb JJ |
299 | list = &e->list; |
300 | } | |
301 | list->next = NULL; | |
302 | list->offset = off; | |
303 | list->idx = 0; | |
304 | return &list->idx; | |
305 | } | |
306 | ||
307 | /* Create a new string index, or return 0 if reached limit. */ | |
308 | ||
309 | static int | |
310 | new_stridx (tree exp) | |
311 | { | |
312 | int idx; | |
313 | if (max_stridx >= PARAM_VALUE (PARAM_MAX_TRACKED_STRLENS)) | |
314 | return 0; | |
315 | if (TREE_CODE (exp) == SSA_NAME) | |
316 | { | |
317 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (exp)) | |
318 | return 0; | |
319 | idx = max_stridx++; | |
9771b263 | 320 | ssa_ver_to_stridx[SSA_NAME_VERSION (exp)] = idx; |
8b57bfeb JJ |
321 | return idx; |
322 | } | |
323 | if (TREE_CODE (exp) == ADDR_EXPR) | |
324 | { | |
325 | int *pidx = addr_stridxptr (TREE_OPERAND (exp, 0)); | |
326 | if (pidx != NULL) | |
327 | { | |
328 | gcc_assert (*pidx == 0); | |
329 | *pidx = max_stridx++; | |
330 | return *pidx; | |
331 | } | |
332 | } | |
333 | return 0; | |
334 | } | |
335 | ||
336 | /* Like new_stridx, but for ADDR_EXPR's operand instead. */ | |
337 | ||
338 | static int | |
339 | new_addr_stridx (tree exp) | |
340 | { | |
341 | int *pidx; | |
342 | if (max_stridx >= PARAM_VALUE (PARAM_MAX_TRACKED_STRLENS)) | |
343 | return 0; | |
344 | pidx = addr_stridxptr (exp); | |
345 | if (pidx != NULL) | |
346 | { | |
347 | gcc_assert (*pidx == 0); | |
348 | *pidx = max_stridx++; | |
349 | return *pidx; | |
350 | } | |
351 | return 0; | |
352 | } | |
353 | ||
354 | /* Create a new strinfo. */ | |
355 | ||
356 | static strinfo | |
357 | new_strinfo (tree ptr, int idx, tree length) | |
358 | { | |
359 | strinfo si = (strinfo) pool_alloc (strinfo_pool); | |
360 | si->length = length; | |
361 | si->ptr = ptr; | |
362 | si->stmt = NULL; | |
363 | si->endptr = NULL_TREE; | |
364 | si->refcount = 1; | |
365 | si->idx = idx; | |
366 | si->first = 0; | |
367 | si->prev = 0; | |
368 | si->next = 0; | |
369 | si->writable = false; | |
370 | si->dont_invalidate = false; | |
371 | return si; | |
372 | } | |
373 | ||
374 | /* Decrease strinfo refcount and free it if not referenced anymore. */ | |
375 | ||
376 | static inline void | |
377 | free_strinfo (strinfo si) | |
378 | { | |
379 | if (si && --si->refcount == 0) | |
380 | pool_free (strinfo_pool, si); | |
381 | } | |
382 | ||
383 | /* Return strinfo vector entry IDX. */ | |
384 | ||
385 | static inline strinfo | |
386 | get_strinfo (int idx) | |
387 | { | |
9771b263 | 388 | if (vec_safe_length (stridx_to_strinfo) <= (unsigned int) idx) |
8b57bfeb | 389 | return NULL; |
9771b263 | 390 | return (*stridx_to_strinfo)[idx]; |
8b57bfeb JJ |
391 | } |
392 | ||
393 | /* Set strinfo in the vector entry IDX to SI. */ | |
394 | ||
395 | static inline void | |
396 | set_strinfo (int idx, strinfo si) | |
397 | { | |
9771b263 | 398 | if (vec_safe_length (stridx_to_strinfo) && (*stridx_to_strinfo)[0]) |
8b57bfeb | 399 | unshare_strinfo_vec (); |
9771b263 DN |
400 | if (vec_safe_length (stridx_to_strinfo) <= (unsigned int) idx) |
401 | vec_safe_grow_cleared (stridx_to_strinfo, idx + 1); | |
402 | (*stridx_to_strinfo)[idx] = si; | |
8b57bfeb JJ |
403 | } |
404 | ||
405 | /* Return string length, or NULL if it can't be computed. */ | |
406 | ||
407 | static tree | |
408 | get_string_length (strinfo si) | |
409 | { | |
410 | if (si->length) | |
411 | return si->length; | |
412 | ||
413 | if (si->stmt) | |
414 | { | |
415 | gimple stmt = si->stmt, lenstmt; | |
83d5977e | 416 | tree callee, lhs, fn, tem; |
8b57bfeb JJ |
417 | location_t loc; |
418 | gimple_stmt_iterator gsi; | |
419 | ||
420 | gcc_assert (is_gimple_call (stmt)); | |
421 | callee = gimple_call_fndecl (stmt); | |
422 | gcc_assert (callee && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL); | |
423 | lhs = gimple_call_lhs (stmt); | |
93a90db6 | 424 | gcc_assert (builtin_decl_implicit_p (BUILT_IN_STPCPY)); |
8b57bfeb JJ |
425 | /* unshare_strinfo is intentionally not called here. The (delayed) |
426 | transformation of strcpy or strcat into stpcpy is done at the place | |
427 | of the former strcpy/strcat call and so can affect all the strinfos | |
428 | with the same stmt. If they were unshared before and transformation | |
429 | has been already done, the handling of BUILT_IN_STPCPY{,_CHK} should | |
430 | just compute the right length. */ | |
431 | switch (DECL_FUNCTION_CODE (callee)) | |
432 | { | |
433 | case BUILT_IN_STRCAT: | |
434 | case BUILT_IN_STRCAT_CHK: | |
435 | gsi = gsi_for_stmt (stmt); | |
e79983f4 | 436 | fn = builtin_decl_implicit (BUILT_IN_STRLEN); |
8b57bfeb | 437 | gcc_assert (lhs == NULL_TREE); |
8b57bfeb JJ |
438 | tem = unshare_expr (gimple_call_arg (stmt, 0)); |
439 | lenstmt = gimple_build_call (fn, 1, tem); | |
83d5977e | 440 | lhs = make_ssa_name (TREE_TYPE (TREE_TYPE (fn)), lenstmt); |
8b57bfeb JJ |
441 | gimple_call_set_lhs (lenstmt, lhs); |
442 | gimple_set_vuse (lenstmt, gimple_vuse (stmt)); | |
443 | gsi_insert_before (&gsi, lenstmt, GSI_SAME_STMT); | |
8b57bfeb | 444 | tem = gimple_call_arg (stmt, 0); |
33960e2e TG |
445 | if (!ptrofftype_p (TREE_TYPE (lhs))) |
446 | { | |
447 | lhs = convert_to_ptrofftype (lhs); | |
448 | lhs = force_gimple_operand_gsi (&gsi, lhs, true, NULL_TREE, | |
449 | true, GSI_SAME_STMT); | |
450 | } | |
8b57bfeb | 451 | lenstmt |
83d5977e RG |
452 | = gimple_build_assign_with_ops |
453 | (POINTER_PLUS_EXPR, | |
454 | make_ssa_name (TREE_TYPE (gimple_call_arg (stmt, 0)), NULL), | |
455 | tem, lhs); | |
8b57bfeb JJ |
456 | gsi_insert_before (&gsi, lenstmt, GSI_SAME_STMT); |
457 | gimple_call_set_arg (stmt, 0, gimple_assign_lhs (lenstmt)); | |
458 | lhs = NULL_TREE; | |
459 | /* FALLTHRU */ | |
460 | case BUILT_IN_STRCPY: | |
461 | case BUILT_IN_STRCPY_CHK: | |
462 | if (gimple_call_num_args (stmt) == 2) | |
e79983f4 | 463 | fn = builtin_decl_implicit (BUILT_IN_STPCPY); |
8b57bfeb | 464 | else |
e79983f4 | 465 | fn = builtin_decl_explicit (BUILT_IN_STPCPY_CHK); |
8b57bfeb JJ |
466 | gcc_assert (lhs == NULL_TREE); |
467 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
468 | { | |
469 | fprintf (dump_file, "Optimizing: "); | |
470 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
471 | } | |
472 | gimple_call_set_fndecl (stmt, fn); | |
83d5977e | 473 | lhs = make_ssa_name (TREE_TYPE (TREE_TYPE (fn)), stmt); |
8b57bfeb JJ |
474 | gimple_call_set_lhs (stmt, lhs); |
475 | update_stmt (stmt); | |
476 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
477 | { | |
478 | fprintf (dump_file, "into: "); | |
479 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
480 | } | |
481 | /* FALLTHRU */ | |
482 | case BUILT_IN_STPCPY: | |
483 | case BUILT_IN_STPCPY_CHK: | |
484 | gcc_assert (lhs != NULL_TREE); | |
485 | loc = gimple_location (stmt); | |
486 | si->endptr = lhs; | |
487 | si->stmt = NULL; | |
488 | lhs = fold_convert_loc (loc, size_type_node, lhs); | |
489 | si->length = fold_convert_loc (loc, size_type_node, si->ptr); | |
490 | si->length = fold_build2_loc (loc, MINUS_EXPR, size_type_node, | |
491 | lhs, si->length); | |
492 | break; | |
493 | default: | |
494 | gcc_unreachable (); | |
495 | break; | |
496 | } | |
497 | } | |
498 | ||
499 | return si->length; | |
500 | } | |
501 | ||
502 | /* Invalidate string length information for strings whose length | |
503 | might change due to stores in stmt. */ | |
504 | ||
505 | static bool | |
506 | maybe_invalidate (gimple stmt) | |
507 | { | |
508 | strinfo si; | |
509 | unsigned int i; | |
510 | bool nonempty = false; | |
511 | ||
9771b263 | 512 | for (i = 1; vec_safe_iterate (stridx_to_strinfo, i, &si); ++i) |
8b57bfeb JJ |
513 | if (si != NULL) |
514 | { | |
515 | if (!si->dont_invalidate) | |
516 | { | |
517 | ao_ref r; | |
518 | ao_ref_init_from_ptr_and_size (&r, si->ptr, NULL_TREE); | |
519 | if (stmt_may_clobber_ref_p_1 (stmt, &r)) | |
520 | { | |
521 | set_strinfo (i, NULL); | |
522 | free_strinfo (si); | |
523 | continue; | |
524 | } | |
525 | } | |
526 | si->dont_invalidate = false; | |
527 | nonempty = true; | |
528 | } | |
529 | return nonempty; | |
530 | } | |
531 | ||
532 | /* Unshare strinfo record SI, if it has recount > 1 or | |
533 | if stridx_to_strinfo vector is shared with some other | |
534 | bbs. */ | |
535 | ||
536 | static strinfo | |
537 | unshare_strinfo (strinfo si) | |
538 | { | |
539 | strinfo nsi; | |
540 | ||
541 | if (si->refcount == 1 && !strinfo_shared ()) | |
542 | return si; | |
543 | ||
544 | nsi = new_strinfo (si->ptr, si->idx, si->length); | |
545 | nsi->stmt = si->stmt; | |
546 | nsi->endptr = si->endptr; | |
547 | nsi->first = si->first; | |
548 | nsi->prev = si->prev; | |
549 | nsi->next = si->next; | |
550 | nsi->writable = si->writable; | |
551 | set_strinfo (si->idx, nsi); | |
552 | free_strinfo (si); | |
553 | return nsi; | |
554 | } | |
555 | ||
556 | /* Return first strinfo in the related strinfo chain | |
557 | if all strinfos in between belong to the chain, otherwise | |
558 | NULL. */ | |
559 | ||
560 | static strinfo | |
561 | verify_related_strinfos (strinfo origsi) | |
562 | { | |
563 | strinfo si = origsi, psi; | |
564 | ||
565 | if (origsi->first == 0) | |
566 | return NULL; | |
567 | for (; si->prev; si = psi) | |
568 | { | |
569 | if (si->first != origsi->first) | |
570 | return NULL; | |
571 | psi = get_strinfo (si->prev); | |
572 | if (psi == NULL) | |
573 | return NULL; | |
574 | if (psi->next != si->idx) | |
575 | return NULL; | |
576 | } | |
577 | if (si->idx != si->first) | |
578 | return NULL; | |
579 | return si; | |
580 | } | |
581 | ||
582 | /* Note that PTR, a pointer SSA_NAME initialized in the current stmt, points | |
583 | to a zero-length string and if possible chain it to a related strinfo | |
584 | chain whose part is or might be CHAINSI. */ | |
585 | ||
586 | static strinfo | |
587 | zero_length_string (tree ptr, strinfo chainsi) | |
588 | { | |
589 | strinfo si; | |
590 | int idx; | |
591 | gcc_checking_assert (TREE_CODE (ptr) == SSA_NAME | |
592 | && get_stridx (ptr) == 0); | |
593 | ||
594 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ptr)) | |
595 | return NULL; | |
596 | if (chainsi != NULL) | |
597 | { | |
598 | si = verify_related_strinfos (chainsi); | |
599 | if (si) | |
600 | { | |
601 | chainsi = si; | |
602 | for (; chainsi->next; chainsi = si) | |
603 | { | |
604 | if (chainsi->endptr == NULL_TREE) | |
605 | { | |
606 | chainsi = unshare_strinfo (chainsi); | |
607 | chainsi->endptr = ptr; | |
608 | } | |
609 | si = get_strinfo (chainsi->next); | |
610 | if (si == NULL | |
611 | || si->first != chainsi->first | |
612 | || si->prev != chainsi->idx) | |
613 | break; | |
614 | } | |
93a90db6 | 615 | gcc_assert (chainsi->length || chainsi->stmt); |
8b57bfeb JJ |
616 | if (chainsi->endptr == NULL_TREE) |
617 | { | |
618 | chainsi = unshare_strinfo (chainsi); | |
619 | chainsi->endptr = ptr; | |
620 | } | |
93a90db6 | 621 | if (chainsi->length && integer_zerop (chainsi->length)) |
8b57bfeb JJ |
622 | { |
623 | if (chainsi->next) | |
624 | { | |
625 | chainsi = unshare_strinfo (chainsi); | |
626 | chainsi->next = 0; | |
627 | } | |
9771b263 | 628 | ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] = chainsi->idx; |
8b57bfeb JJ |
629 | return chainsi; |
630 | } | |
631 | } | |
632 | else if (chainsi->first || chainsi->prev || chainsi->next) | |
633 | { | |
634 | chainsi = unshare_strinfo (chainsi); | |
635 | chainsi->first = 0; | |
636 | chainsi->prev = 0; | |
637 | chainsi->next = 0; | |
638 | } | |
639 | } | |
640 | idx = new_stridx (ptr); | |
641 | if (idx == 0) | |
642 | return NULL; | |
643 | si = new_strinfo (ptr, idx, build_int_cst (size_type_node, 0)); | |
644 | set_strinfo (idx, si); | |
645 | si->endptr = ptr; | |
646 | if (chainsi != NULL) | |
647 | { | |
648 | chainsi = unshare_strinfo (chainsi); | |
649 | if (chainsi->first == 0) | |
650 | chainsi->first = chainsi->idx; | |
651 | chainsi->next = idx; | |
93a90db6 AK |
652 | if (chainsi->endptr == NULL_TREE) |
653 | chainsi->endptr = ptr; | |
8b57bfeb JJ |
654 | si->prev = chainsi->idx; |
655 | si->first = chainsi->first; | |
656 | si->writable = chainsi->writable; | |
657 | } | |
658 | return si; | |
659 | } | |
660 | ||
661 | /* For strinfo ORIGSI whose length has been just updated | |
662 | update also related strinfo lengths (add ADJ to each, | |
663 | but don't adjust ORIGSI). */ | |
664 | ||
665 | static void | |
666 | adjust_related_strinfos (location_t loc, strinfo origsi, tree adj) | |
667 | { | |
668 | strinfo si = verify_related_strinfos (origsi); | |
669 | ||
670 | if (si == NULL) | |
671 | return; | |
672 | ||
673 | while (1) | |
674 | { | |
675 | strinfo nsi; | |
676 | ||
677 | if (si != origsi) | |
678 | { | |
679 | tree tem; | |
680 | ||
681 | si = unshare_strinfo (si); | |
93a90db6 AK |
682 | if (si->length) |
683 | { | |
684 | tem = fold_convert_loc (loc, TREE_TYPE (si->length), adj); | |
685 | si->length = fold_build2_loc (loc, PLUS_EXPR, | |
686 | TREE_TYPE (si->length), si->length, | |
687 | tem); | |
688 | } | |
689 | else if (si->stmt != NULL) | |
690 | /* Delayed length computation is unaffected. */ | |
691 | ; | |
692 | else | |
693 | gcc_unreachable (); | |
694 | ||
8b57bfeb JJ |
695 | si->endptr = NULL_TREE; |
696 | si->dont_invalidate = true; | |
697 | } | |
698 | if (si->next == 0) | |
699 | return; | |
700 | nsi = get_strinfo (si->next); | |
701 | if (nsi == NULL | |
702 | || nsi->first != si->first | |
703 | || nsi->prev != si->idx) | |
704 | return; | |
705 | si = nsi; | |
706 | } | |
707 | } | |
708 | ||
709 | /* Find if there are other SSA_NAME pointers equal to PTR | |
710 | for which we don't track their string lengths yet. If so, use | |
711 | IDX for them. */ | |
712 | ||
713 | static void | |
714 | find_equal_ptrs (tree ptr, int idx) | |
715 | { | |
716 | if (TREE_CODE (ptr) != SSA_NAME) | |
717 | return; | |
718 | while (1) | |
719 | { | |
720 | gimple stmt = SSA_NAME_DEF_STMT (ptr); | |
721 | if (!is_gimple_assign (stmt)) | |
722 | return; | |
723 | ptr = gimple_assign_rhs1 (stmt); | |
724 | switch (gimple_assign_rhs_code (stmt)) | |
725 | { | |
726 | case SSA_NAME: | |
727 | break; | |
97246d78 JJ |
728 | CASE_CONVERT: |
729 | if (!POINTER_TYPE_P (TREE_TYPE (ptr))) | |
730 | return; | |
731 | if (TREE_CODE (ptr) == SSA_NAME) | |
732 | break; | |
733 | if (TREE_CODE (ptr) != ADDR_EXPR) | |
734 | return; | |
735 | /* FALLTHRU */ | |
8b57bfeb JJ |
736 | case ADDR_EXPR: |
737 | { | |
738 | int *pidx = addr_stridxptr (TREE_OPERAND (ptr, 0)); | |
739 | if (pidx != NULL && *pidx == 0) | |
740 | *pidx = idx; | |
741 | return; | |
742 | } | |
8b57bfeb JJ |
743 | default: |
744 | return; | |
745 | } | |
746 | ||
747 | /* We might find an endptr created in this pass. Grow the | |
748 | vector in that case. */ | |
9771b263 DN |
749 | if (ssa_ver_to_stridx.length () <= SSA_NAME_VERSION (ptr)) |
750 | ssa_ver_to_stridx.safe_grow_cleared (num_ssa_names); | |
8b57bfeb | 751 | |
9771b263 | 752 | if (ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] != 0) |
8b57bfeb | 753 | return; |
9771b263 | 754 | ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] = idx; |
8b57bfeb JJ |
755 | } |
756 | } | |
757 | ||
758 | /* If the last .MEM setter statement before STMT is | |
759 | memcpy (x, y, strlen (y) + 1), the only .MEM use of it is STMT | |
760 | and STMT is known to overwrite x[strlen (x)], adjust the last memcpy to | |
761 | just memcpy (x, y, strlen (y)). SI must be the zero length | |
762 | strinfo. */ | |
763 | ||
764 | static void | |
765 | adjust_last_stmt (strinfo si, gimple stmt, bool is_strcat) | |
766 | { | |
767 | tree vuse, callee, len; | |
768 | struct laststmt_struct last = laststmt; | |
769 | strinfo lastsi, firstsi; | |
770 | ||
771 | laststmt.stmt = NULL; | |
772 | laststmt.len = NULL_TREE; | |
773 | laststmt.stridx = 0; | |
774 | ||
775 | if (last.stmt == NULL) | |
776 | return; | |
777 | ||
778 | vuse = gimple_vuse (stmt); | |
779 | if (vuse == NULL_TREE | |
780 | || SSA_NAME_DEF_STMT (vuse) != last.stmt | |
781 | || !has_single_use (vuse)) | |
782 | return; | |
783 | ||
784 | gcc_assert (last.stridx > 0); | |
785 | lastsi = get_strinfo (last.stridx); | |
786 | if (lastsi == NULL) | |
787 | return; | |
788 | ||
789 | if (lastsi != si) | |
790 | { | |
791 | if (lastsi->first == 0 || lastsi->first != si->first) | |
792 | return; | |
793 | ||
794 | firstsi = verify_related_strinfos (si); | |
795 | if (firstsi == NULL) | |
796 | return; | |
797 | while (firstsi != lastsi) | |
798 | { | |
799 | strinfo nextsi; | |
800 | if (firstsi->next == 0) | |
801 | return; | |
802 | nextsi = get_strinfo (firstsi->next); | |
803 | if (nextsi == NULL | |
804 | || nextsi->prev != firstsi->idx | |
805 | || nextsi->first != si->first) | |
806 | return; | |
807 | firstsi = nextsi; | |
808 | } | |
809 | } | |
810 | ||
811 | if (!is_strcat) | |
812 | { | |
813 | if (si->length == NULL_TREE || !integer_zerop (si->length)) | |
814 | return; | |
815 | } | |
816 | ||
817 | if (is_gimple_assign (last.stmt)) | |
818 | { | |
819 | gimple_stmt_iterator gsi; | |
820 | ||
821 | if (!integer_zerop (gimple_assign_rhs1 (last.stmt))) | |
822 | return; | |
823 | if (stmt_could_throw_p (last.stmt)) | |
824 | return; | |
825 | gsi = gsi_for_stmt (last.stmt); | |
826 | unlink_stmt_vdef (last.stmt); | |
827 | release_defs (last.stmt); | |
828 | gsi_remove (&gsi, true); | |
829 | return; | |
830 | } | |
831 | ||
3626621a | 832 | if (!gimple_call_builtin_p (last.stmt, BUILT_IN_NORMAL)) |
8b57bfeb JJ |
833 | return; |
834 | ||
3626621a | 835 | callee = gimple_call_fndecl (last.stmt); |
8b57bfeb JJ |
836 | switch (DECL_FUNCTION_CODE (callee)) |
837 | { | |
838 | case BUILT_IN_MEMCPY: | |
839 | case BUILT_IN_MEMCPY_CHK: | |
840 | break; | |
841 | default: | |
842 | return; | |
843 | } | |
844 | ||
845 | len = gimple_call_arg (last.stmt, 2); | |
846 | if (host_integerp (len, 1)) | |
847 | { | |
848 | if (!host_integerp (last.len, 1) | |
849 | || integer_zerop (len) | |
850 | || (unsigned HOST_WIDE_INT) tree_low_cst (len, 1) | |
851 | != (unsigned HOST_WIDE_INT) tree_low_cst (last.len, 1) + 1) | |
852 | return; | |
853 | /* Don't adjust the length if it is divisible by 4, it is more efficient | |
854 | to store the extra '\0' in that case. */ | |
855 | if ((((unsigned HOST_WIDE_INT) tree_low_cst (len, 1)) & 3) == 0) | |
856 | return; | |
857 | } | |
858 | else if (TREE_CODE (len) == SSA_NAME) | |
859 | { | |
860 | gimple def_stmt = SSA_NAME_DEF_STMT (len); | |
861 | if (!is_gimple_assign (def_stmt) | |
862 | || gimple_assign_rhs_code (def_stmt) != PLUS_EXPR | |
863 | || gimple_assign_rhs1 (def_stmt) != last.len | |
864 | || !integer_onep (gimple_assign_rhs2 (def_stmt))) | |
865 | return; | |
866 | } | |
867 | else | |
868 | return; | |
869 | ||
870 | gimple_call_set_arg (last.stmt, 2, last.len); | |
871 | update_stmt (last.stmt); | |
872 | } | |
873 | ||
874 | /* Handle a strlen call. If strlen of the argument is known, replace | |
875 | the strlen call with the known value, otherwise remember that strlen | |
876 | of the argument is stored in the lhs SSA_NAME. */ | |
877 | ||
878 | static void | |
879 | handle_builtin_strlen (gimple_stmt_iterator *gsi) | |
880 | { | |
881 | int idx; | |
882 | tree src; | |
883 | gimple stmt = gsi_stmt (*gsi); | |
884 | tree lhs = gimple_call_lhs (stmt); | |
885 | ||
886 | if (lhs == NULL_TREE) | |
887 | return; | |
888 | ||
889 | src = gimple_call_arg (stmt, 0); | |
890 | idx = get_stridx (src); | |
891 | if (idx) | |
892 | { | |
893 | strinfo si = NULL; | |
894 | tree rhs; | |
895 | ||
896 | if (idx < 0) | |
897 | rhs = build_int_cst (TREE_TYPE (lhs), ~idx); | |
898 | else | |
899 | { | |
900 | rhs = NULL_TREE; | |
901 | si = get_strinfo (idx); | |
902 | if (si != NULL) | |
903 | rhs = get_string_length (si); | |
904 | } | |
905 | if (rhs != NULL_TREE) | |
906 | { | |
907 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
908 | { | |
909 | fprintf (dump_file, "Optimizing: "); | |
910 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
911 | } | |
912 | rhs = unshare_expr (rhs); | |
913 | if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs))) | |
914 | rhs = fold_convert_loc (gimple_location (stmt), | |
915 | TREE_TYPE (lhs), rhs); | |
916 | if (!update_call_from_tree (gsi, rhs)) | |
917 | gimplify_and_update_call_from_tree (gsi, rhs); | |
918 | stmt = gsi_stmt (*gsi); | |
919 | update_stmt (stmt); | |
920 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
921 | { | |
922 | fprintf (dump_file, "into: "); | |
923 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
924 | } | |
925 | if (si != NULL | |
926 | && TREE_CODE (si->length) != SSA_NAME | |
927 | && TREE_CODE (si->length) != INTEGER_CST | |
928 | && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
929 | { | |
930 | si = unshare_strinfo (si); | |
931 | si->length = lhs; | |
932 | } | |
933 | return; | |
934 | } | |
935 | } | |
936 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
937 | return; | |
938 | if (idx == 0) | |
939 | idx = new_stridx (src); | |
940 | else if (get_strinfo (idx) != NULL) | |
941 | return; | |
942 | if (idx) | |
943 | { | |
944 | strinfo si = new_strinfo (src, idx, lhs); | |
945 | set_strinfo (idx, si); | |
946 | find_equal_ptrs (src, idx); | |
947 | } | |
948 | } | |
949 | ||
950 | /* Handle a strchr call. If strlen of the first argument is known, replace | |
951 | the strchr (x, 0) call with the endptr or x + strlen, otherwise remember | |
952 | that lhs of the call is endptr and strlen of the argument is endptr - x. */ | |
953 | ||
954 | static void | |
955 | handle_builtin_strchr (gimple_stmt_iterator *gsi) | |
956 | { | |
957 | int idx; | |
958 | tree src; | |
959 | gimple stmt = gsi_stmt (*gsi); | |
960 | tree lhs = gimple_call_lhs (stmt); | |
961 | ||
962 | if (lhs == NULL_TREE) | |
963 | return; | |
964 | ||
965 | if (!integer_zerop (gimple_call_arg (stmt, 1))) | |
966 | return; | |
967 | ||
968 | src = gimple_call_arg (stmt, 0); | |
969 | idx = get_stridx (src); | |
970 | if (idx) | |
971 | { | |
972 | strinfo si = NULL; | |
973 | tree rhs; | |
974 | ||
975 | if (idx < 0) | |
976 | rhs = build_int_cst (size_type_node, ~idx); | |
977 | else | |
978 | { | |
979 | rhs = NULL_TREE; | |
980 | si = get_strinfo (idx); | |
981 | if (si != NULL) | |
982 | rhs = get_string_length (si); | |
983 | } | |
984 | if (rhs != NULL_TREE) | |
985 | { | |
986 | location_t loc = gimple_location (stmt); | |
987 | ||
988 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
989 | { | |
990 | fprintf (dump_file, "Optimizing: "); | |
991 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
992 | } | |
993 | if (si != NULL && si->endptr != NULL_TREE) | |
994 | { | |
995 | rhs = unshare_expr (si->endptr); | |
996 | if (!useless_type_conversion_p (TREE_TYPE (lhs), | |
997 | TREE_TYPE (rhs))) | |
998 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); | |
999 | } | |
1000 | else | |
1001 | { | |
1002 | rhs = fold_convert_loc (loc, sizetype, unshare_expr (rhs)); | |
1003 | rhs = fold_build2_loc (loc, POINTER_PLUS_EXPR, | |
1004 | TREE_TYPE (src), src, rhs); | |
1005 | if (!useless_type_conversion_p (TREE_TYPE (lhs), | |
1006 | TREE_TYPE (rhs))) | |
1007 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); | |
1008 | } | |
1009 | if (!update_call_from_tree (gsi, rhs)) | |
1010 | gimplify_and_update_call_from_tree (gsi, rhs); | |
1011 | stmt = gsi_stmt (*gsi); | |
1012 | update_stmt (stmt); | |
1013 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1014 | { | |
1015 | fprintf (dump_file, "into: "); | |
1016 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1017 | } | |
1018 | if (si != NULL | |
1019 | && si->endptr == NULL_TREE | |
1020 | && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
1021 | { | |
1022 | si = unshare_strinfo (si); | |
1023 | si->endptr = lhs; | |
1024 | } | |
1025 | zero_length_string (lhs, si); | |
1026 | return; | |
1027 | } | |
1028 | } | |
1029 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
1030 | return; | |
1031 | if (TREE_CODE (src) != SSA_NAME || !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (src)) | |
1032 | { | |
1033 | if (idx == 0) | |
1034 | idx = new_stridx (src); | |
1035 | else if (get_strinfo (idx) != NULL) | |
1036 | { | |
1037 | zero_length_string (lhs, NULL); | |
1038 | return; | |
1039 | } | |
1040 | if (idx) | |
1041 | { | |
1042 | location_t loc = gimple_location (stmt); | |
1043 | tree lhsu = fold_convert_loc (loc, size_type_node, lhs); | |
1044 | tree srcu = fold_convert_loc (loc, size_type_node, src); | |
1045 | tree length = fold_build2_loc (loc, MINUS_EXPR, | |
1046 | size_type_node, lhsu, srcu); | |
1047 | strinfo si = new_strinfo (src, idx, length); | |
1048 | si->endptr = lhs; | |
1049 | set_strinfo (idx, si); | |
1050 | find_equal_ptrs (src, idx); | |
1051 | zero_length_string (lhs, si); | |
1052 | } | |
1053 | } | |
1054 | else | |
1055 | zero_length_string (lhs, NULL); | |
1056 | } | |
1057 | ||
1058 | /* Handle a strcpy-like ({st{r,p}cpy,__st{r,p}cpy_chk}) call. | |
1059 | If strlen of the second argument is known, strlen of the first argument | |
1060 | is the same after this call. Furthermore, attempt to convert it to | |
1061 | memcpy. */ | |
1062 | ||
1063 | static void | |
1064 | handle_builtin_strcpy (enum built_in_function bcode, gimple_stmt_iterator *gsi) | |
1065 | { | |
1066 | int idx, didx; | |
1067 | tree src, dst, srclen, len, lhs, args, type, fn, oldlen; | |
1068 | bool success; | |
1069 | gimple stmt = gsi_stmt (*gsi); | |
1070 | strinfo si, dsi, olddsi, zsi; | |
1071 | location_t loc; | |
1072 | ||
1073 | src = gimple_call_arg (stmt, 1); | |
1074 | dst = gimple_call_arg (stmt, 0); | |
1075 | lhs = gimple_call_lhs (stmt); | |
1076 | idx = get_stridx (src); | |
1077 | si = NULL; | |
1078 | if (idx > 0) | |
1079 | si = get_strinfo (idx); | |
1080 | ||
1081 | didx = get_stridx (dst); | |
1082 | olddsi = NULL; | |
1083 | oldlen = NULL_TREE; | |
1084 | if (didx > 0) | |
1085 | olddsi = get_strinfo (didx); | |
1086 | else if (didx < 0) | |
1087 | return; | |
1088 | ||
1089 | if (olddsi != NULL) | |
1090 | adjust_last_stmt (olddsi, stmt, false); | |
1091 | ||
1092 | srclen = NULL_TREE; | |
1093 | if (si != NULL) | |
1094 | srclen = get_string_length (si); | |
1095 | else if (idx < 0) | |
1096 | srclen = build_int_cst (size_type_node, ~idx); | |
1097 | ||
1098 | loc = gimple_location (stmt); | |
1099 | if (srclen == NULL_TREE) | |
1100 | switch (bcode) | |
1101 | { | |
1102 | case BUILT_IN_STRCPY: | |
1103 | case BUILT_IN_STRCPY_CHK: | |
e79983f4 | 1104 | if (lhs != NULL_TREE || !builtin_decl_implicit_p (BUILT_IN_STPCPY)) |
8b57bfeb JJ |
1105 | return; |
1106 | break; | |
1107 | case BUILT_IN_STPCPY: | |
1108 | case BUILT_IN_STPCPY_CHK: | |
1109 | if (lhs == NULL_TREE) | |
1110 | return; | |
1111 | else | |
1112 | { | |
1113 | tree lhsuint = fold_convert_loc (loc, size_type_node, lhs); | |
1114 | srclen = fold_convert_loc (loc, size_type_node, dst); | |
1115 | srclen = fold_build2_loc (loc, MINUS_EXPR, size_type_node, | |
1116 | lhsuint, srclen); | |
1117 | } | |
1118 | break; | |
1119 | default: | |
1120 | gcc_unreachable (); | |
1121 | } | |
1122 | ||
1123 | if (didx == 0) | |
1124 | { | |
1125 | didx = new_stridx (dst); | |
1126 | if (didx == 0) | |
1127 | return; | |
1128 | } | |
1129 | if (olddsi != NULL) | |
1130 | { | |
1131 | oldlen = olddsi->length; | |
1132 | dsi = unshare_strinfo (olddsi); | |
1133 | dsi->length = srclen; | |
1134 | /* Break the chain, so adjust_related_strinfo on later pointers in | |
1135 | the chain won't adjust this one anymore. */ | |
1136 | dsi->next = 0; | |
1137 | dsi->stmt = NULL; | |
1138 | dsi->endptr = NULL_TREE; | |
1139 | } | |
1140 | else | |
1141 | { | |
1142 | dsi = new_strinfo (dst, didx, srclen); | |
1143 | set_strinfo (didx, dsi); | |
1144 | find_equal_ptrs (dst, didx); | |
1145 | } | |
1146 | dsi->writable = true; | |
1147 | dsi->dont_invalidate = true; | |
1148 | ||
1149 | if (dsi->length == NULL_TREE) | |
1150 | { | |
93a90db6 AK |
1151 | strinfo chainsi; |
1152 | ||
8b57bfeb JJ |
1153 | /* If string length of src is unknown, use delayed length |
1154 | computation. If string lenth of dst will be needed, it | |
1155 | can be computed by transforming this strcpy call into | |
1156 | stpcpy and subtracting dst from the return value. */ | |
93a90db6 AK |
1157 | |
1158 | /* Look for earlier strings whose length could be determined if | |
1159 | this strcpy is turned into an stpcpy. */ | |
1160 | ||
1161 | if (dsi->prev != 0 && (chainsi = verify_related_strinfos (dsi)) != NULL) | |
1162 | { | |
1163 | for (; chainsi && chainsi != dsi; chainsi = get_strinfo (chainsi->next)) | |
1164 | { | |
1165 | /* When setting a stmt for delayed length computation | |
1166 | prevent all strinfos through dsi from being | |
1167 | invalidated. */ | |
1168 | chainsi = unshare_strinfo (chainsi); | |
1169 | chainsi->stmt = stmt; | |
1170 | chainsi->length = NULL_TREE; | |
1171 | chainsi->endptr = NULL_TREE; | |
1172 | chainsi->dont_invalidate = true; | |
1173 | } | |
1174 | } | |
8b57bfeb JJ |
1175 | dsi->stmt = stmt; |
1176 | return; | |
1177 | } | |
1178 | ||
1179 | if (olddsi != NULL) | |
1180 | { | |
1181 | tree adj = NULL_TREE; | |
1182 | if (oldlen == NULL_TREE) | |
1183 | ; | |
1184 | else if (integer_zerop (oldlen)) | |
1185 | adj = srclen; | |
1186 | else if (TREE_CODE (oldlen) == INTEGER_CST | |
1187 | || TREE_CODE (srclen) == INTEGER_CST) | |
1188 | adj = fold_build2_loc (loc, MINUS_EXPR, | |
1189 | TREE_TYPE (srclen), srclen, | |
1190 | fold_convert_loc (loc, TREE_TYPE (srclen), | |
1191 | oldlen)); | |
1192 | if (adj != NULL_TREE) | |
1193 | adjust_related_strinfos (loc, dsi, adj); | |
1194 | else | |
1195 | dsi->prev = 0; | |
1196 | } | |
1197 | /* strcpy src may not overlap dst, so src doesn't need to be | |
1198 | invalidated either. */ | |
1199 | if (si != NULL) | |
1200 | si->dont_invalidate = true; | |
1201 | ||
1202 | fn = NULL_TREE; | |
1203 | zsi = NULL; | |
1204 | switch (bcode) | |
1205 | { | |
1206 | case BUILT_IN_STRCPY: | |
e79983f4 | 1207 | fn = builtin_decl_implicit (BUILT_IN_MEMCPY); |
8b57bfeb | 1208 | if (lhs) |
9771b263 | 1209 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] = didx; |
8b57bfeb JJ |
1210 | break; |
1211 | case BUILT_IN_STRCPY_CHK: | |
e79983f4 | 1212 | fn = builtin_decl_explicit (BUILT_IN_MEMCPY_CHK); |
8b57bfeb | 1213 | if (lhs) |
9771b263 | 1214 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] = didx; |
8b57bfeb JJ |
1215 | break; |
1216 | case BUILT_IN_STPCPY: | |
1217 | /* This would need adjustment of the lhs (subtract one), | |
1218 | or detection that the trailing '\0' doesn't need to be | |
1219 | written, if it will be immediately overwritten. | |
e79983f4 | 1220 | fn = builtin_decl_explicit (BUILT_IN_MEMPCPY); */ |
8b57bfeb JJ |
1221 | if (lhs) |
1222 | { | |
1223 | dsi->endptr = lhs; | |
1224 | zsi = zero_length_string (lhs, dsi); | |
1225 | } | |
1226 | break; | |
1227 | case BUILT_IN_STPCPY_CHK: | |
1228 | /* This would need adjustment of the lhs (subtract one), | |
1229 | or detection that the trailing '\0' doesn't need to be | |
1230 | written, if it will be immediately overwritten. | |
e79983f4 | 1231 | fn = builtin_decl_explicit (BUILT_IN_MEMPCPY_CHK); */ |
8b57bfeb JJ |
1232 | if (lhs) |
1233 | { | |
1234 | dsi->endptr = lhs; | |
1235 | zsi = zero_length_string (lhs, dsi); | |
1236 | } | |
1237 | break; | |
1238 | default: | |
1239 | gcc_unreachable (); | |
1240 | } | |
1241 | if (zsi != NULL) | |
1242 | zsi->dont_invalidate = true; | |
1243 | ||
1244 | if (fn == NULL_TREE) | |
1245 | return; | |
1246 | ||
1247 | args = TYPE_ARG_TYPES (TREE_TYPE (fn)); | |
1248 | type = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (args))); | |
1249 | ||
1250 | len = fold_convert_loc (loc, type, unshare_expr (srclen)); | |
1251 | len = fold_build2_loc (loc, PLUS_EXPR, type, len, build_int_cst (type, 1)); | |
1252 | len = force_gimple_operand_gsi (gsi, len, true, NULL_TREE, true, | |
1253 | GSI_SAME_STMT); | |
1254 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1255 | { | |
1256 | fprintf (dump_file, "Optimizing: "); | |
1257 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1258 | } | |
1259 | if (gimple_call_num_args (stmt) == 2) | |
1260 | success = update_gimple_call (gsi, fn, 3, dst, src, len); | |
1261 | else | |
1262 | success = update_gimple_call (gsi, fn, 4, dst, src, len, | |
1263 | gimple_call_arg (stmt, 2)); | |
1264 | if (success) | |
1265 | { | |
1266 | stmt = gsi_stmt (*gsi); | |
1267 | update_stmt (stmt); | |
1268 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1269 | { | |
1270 | fprintf (dump_file, "into: "); | |
1271 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1272 | } | |
1273 | /* Allow adjust_last_stmt to decrease this memcpy's size. */ | |
1274 | laststmt.stmt = stmt; | |
1275 | laststmt.len = srclen; | |
1276 | laststmt.stridx = dsi->idx; | |
1277 | } | |
1278 | else if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1279 | fprintf (dump_file, "not possible.\n"); | |
1280 | } | |
1281 | ||
1282 | /* Handle a memcpy-like ({mem{,p}cpy,__mem{,p}cpy_chk}) call. | |
1283 | If strlen of the second argument is known and length of the third argument | |
1284 | is that plus one, strlen of the first argument is the same after this | |
1285 | call. */ | |
1286 | ||
1287 | static void | |
1288 | handle_builtin_memcpy (enum built_in_function bcode, gimple_stmt_iterator *gsi) | |
1289 | { | |
1290 | int idx, didx; | |
1291 | tree src, dst, len, lhs, oldlen, newlen; | |
1292 | gimple stmt = gsi_stmt (*gsi); | |
1293 | strinfo si, dsi, olddsi; | |
1294 | ||
1295 | len = gimple_call_arg (stmt, 2); | |
1296 | src = gimple_call_arg (stmt, 1); | |
1297 | dst = gimple_call_arg (stmt, 0); | |
1298 | idx = get_stridx (src); | |
1299 | if (idx == 0) | |
1300 | return; | |
1301 | ||
1302 | didx = get_stridx (dst); | |
1303 | olddsi = NULL; | |
1304 | if (didx > 0) | |
1305 | olddsi = get_strinfo (didx); | |
1306 | else if (didx < 0) | |
1307 | return; | |
1308 | ||
1309 | if (olddsi != NULL | |
1310 | && host_integerp (len, 1) | |
1311 | && !integer_zerop (len)) | |
1312 | adjust_last_stmt (olddsi, stmt, false); | |
1313 | ||
1314 | if (idx > 0) | |
1315 | { | |
1316 | gimple def_stmt; | |
1317 | ||
1318 | /* Handle memcpy (x, y, l) where l is strlen (y) + 1. */ | |
1319 | si = get_strinfo (idx); | |
1320 | if (si == NULL || si->length == NULL_TREE) | |
1321 | return; | |
1322 | if (TREE_CODE (len) != SSA_NAME) | |
1323 | return; | |
1324 | def_stmt = SSA_NAME_DEF_STMT (len); | |
1325 | if (!is_gimple_assign (def_stmt) | |
1326 | || gimple_assign_rhs_code (def_stmt) != PLUS_EXPR | |
1327 | || gimple_assign_rhs1 (def_stmt) != si->length | |
1328 | || !integer_onep (gimple_assign_rhs2 (def_stmt))) | |
1329 | return; | |
1330 | } | |
1331 | else | |
1332 | { | |
1333 | si = NULL; | |
1334 | /* Handle memcpy (x, "abcd", 5) or | |
1335 | memcpy (x, "abc\0uvw", 7). */ | |
1336 | if (!host_integerp (len, 1) | |
1337 | || (unsigned HOST_WIDE_INT) tree_low_cst (len, 1) | |
1338 | <= (unsigned HOST_WIDE_INT) ~idx) | |
1339 | return; | |
1340 | } | |
1341 | ||
1342 | if (olddsi != NULL && TREE_CODE (len) == SSA_NAME) | |
1343 | adjust_last_stmt (olddsi, stmt, false); | |
1344 | ||
1345 | if (didx == 0) | |
1346 | { | |
1347 | didx = new_stridx (dst); | |
1348 | if (didx == 0) | |
1349 | return; | |
1350 | } | |
1351 | if (si != NULL) | |
1352 | newlen = si->length; | |
1353 | else | |
80642376 | 1354 | newlen = build_int_cst (size_type_node, ~idx); |
8b57bfeb JJ |
1355 | oldlen = NULL_TREE; |
1356 | if (olddsi != NULL) | |
1357 | { | |
1358 | dsi = unshare_strinfo (olddsi); | |
1359 | oldlen = olddsi->length; | |
1360 | dsi->length = newlen; | |
1361 | /* Break the chain, so adjust_related_strinfo on later pointers in | |
1362 | the chain won't adjust this one anymore. */ | |
1363 | dsi->next = 0; | |
1364 | dsi->stmt = NULL; | |
1365 | dsi->endptr = NULL_TREE; | |
1366 | } | |
1367 | else | |
1368 | { | |
1369 | dsi = new_strinfo (dst, didx, newlen); | |
1370 | set_strinfo (didx, dsi); | |
1371 | find_equal_ptrs (dst, didx); | |
1372 | } | |
1373 | dsi->writable = true; | |
1374 | dsi->dont_invalidate = true; | |
1375 | if (olddsi != NULL) | |
1376 | { | |
1377 | tree adj = NULL_TREE; | |
1378 | location_t loc = gimple_location (stmt); | |
1379 | if (oldlen == NULL_TREE) | |
1380 | ; | |
1381 | else if (integer_zerop (oldlen)) | |
1382 | adj = dsi->length; | |
1383 | else if (TREE_CODE (oldlen) == INTEGER_CST | |
1384 | || TREE_CODE (dsi->length) == INTEGER_CST) | |
1385 | adj = fold_build2_loc (loc, MINUS_EXPR, | |
1386 | TREE_TYPE (dsi->length), dsi->length, | |
1387 | fold_convert_loc (loc, TREE_TYPE (dsi->length), | |
1388 | oldlen)); | |
1389 | if (adj != NULL_TREE) | |
1390 | adjust_related_strinfos (loc, dsi, adj); | |
1391 | else | |
1392 | dsi->prev = 0; | |
1393 | } | |
1394 | /* memcpy src may not overlap dst, so src doesn't need to be | |
1395 | invalidated either. */ | |
1396 | if (si != NULL) | |
1397 | si->dont_invalidate = true; | |
1398 | ||
1399 | lhs = gimple_call_lhs (stmt); | |
1400 | switch (bcode) | |
1401 | { | |
1402 | case BUILT_IN_MEMCPY: | |
1403 | case BUILT_IN_MEMCPY_CHK: | |
1404 | /* Allow adjust_last_stmt to decrease this memcpy's size. */ | |
1405 | laststmt.stmt = stmt; | |
1406 | laststmt.len = dsi->length; | |
1407 | laststmt.stridx = dsi->idx; | |
1408 | if (lhs) | |
9771b263 | 1409 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] = didx; |
8b57bfeb JJ |
1410 | break; |
1411 | case BUILT_IN_MEMPCPY: | |
1412 | case BUILT_IN_MEMPCPY_CHK: | |
1413 | break; | |
1414 | default: | |
1415 | gcc_unreachable (); | |
1416 | } | |
1417 | } | |
1418 | ||
1419 | /* Handle a strcat-like ({strcat,__strcat_chk}) call. | |
1420 | If strlen of the second argument is known, strlen of the first argument | |
1421 | is increased by the length of the second argument. Furthermore, attempt | |
1422 | to convert it to memcpy/strcpy if the length of the first argument | |
1423 | is known. */ | |
1424 | ||
1425 | static void | |
1426 | handle_builtin_strcat (enum built_in_function bcode, gimple_stmt_iterator *gsi) | |
1427 | { | |
1428 | int idx, didx; | |
1429 | tree src, dst, srclen, dstlen, len, lhs, args, type, fn, objsz, endptr; | |
1430 | bool success; | |
1431 | gimple stmt = gsi_stmt (*gsi); | |
1432 | strinfo si, dsi; | |
1433 | location_t loc; | |
1434 | ||
1435 | src = gimple_call_arg (stmt, 1); | |
1436 | dst = gimple_call_arg (stmt, 0); | |
1437 | lhs = gimple_call_lhs (stmt); | |
1438 | ||
1439 | didx = get_stridx (dst); | |
1440 | if (didx < 0) | |
1441 | return; | |
1442 | ||
1443 | dsi = NULL; | |
1444 | if (didx > 0) | |
1445 | dsi = get_strinfo (didx); | |
1446 | if (dsi == NULL || get_string_length (dsi) == NULL_TREE) | |
1447 | { | |
1448 | /* strcat (p, q) can be transformed into | |
1449 | tmp = p + strlen (p); endptr = strpcpy (tmp, q); | |
1450 | with length endptr - p if we need to compute the length | |
1451 | later on. Don't do this transformation if we don't need | |
1452 | it. */ | |
e79983f4 | 1453 | if (builtin_decl_implicit_p (BUILT_IN_STPCPY) && lhs == NULL_TREE) |
8b57bfeb JJ |
1454 | { |
1455 | if (didx == 0) | |
1456 | { | |
1457 | didx = new_stridx (dst); | |
1458 | if (didx == 0) | |
1459 | return; | |
1460 | } | |
1461 | if (dsi == NULL) | |
1462 | { | |
1463 | dsi = new_strinfo (dst, didx, NULL_TREE); | |
1464 | set_strinfo (didx, dsi); | |
1465 | find_equal_ptrs (dst, didx); | |
1466 | } | |
1467 | else | |
1468 | { | |
1469 | dsi = unshare_strinfo (dsi); | |
1470 | dsi->length = NULL_TREE; | |
1471 | dsi->next = 0; | |
1472 | dsi->endptr = NULL_TREE; | |
1473 | } | |
1474 | dsi->writable = true; | |
1475 | dsi->stmt = stmt; | |
1476 | dsi->dont_invalidate = true; | |
1477 | } | |
1478 | return; | |
1479 | } | |
1480 | ||
1481 | srclen = NULL_TREE; | |
1482 | si = NULL; | |
1483 | idx = get_stridx (src); | |
1484 | if (idx < 0) | |
1485 | srclen = build_int_cst (size_type_node, ~idx); | |
1486 | else if (idx > 0) | |
1487 | { | |
1488 | si = get_strinfo (idx); | |
1489 | if (si != NULL) | |
1490 | srclen = get_string_length (si); | |
1491 | } | |
1492 | ||
1493 | loc = gimple_location (stmt); | |
1494 | dstlen = dsi->length; | |
1495 | endptr = dsi->endptr; | |
1496 | ||
1497 | dsi = unshare_strinfo (dsi); | |
1498 | dsi->endptr = NULL_TREE; | |
1499 | dsi->stmt = NULL; | |
1500 | dsi->writable = true; | |
1501 | ||
1502 | if (srclen != NULL_TREE) | |
1503 | { | |
1504 | dsi->length = fold_build2_loc (loc, PLUS_EXPR, TREE_TYPE (dsi->length), | |
1505 | dsi->length, srclen); | |
1506 | adjust_related_strinfos (loc, dsi, srclen); | |
1507 | dsi->dont_invalidate = true; | |
1508 | } | |
1509 | else | |
1510 | { | |
1511 | dsi->length = NULL; | |
e79983f4 | 1512 | if (lhs == NULL_TREE && builtin_decl_implicit_p (BUILT_IN_STPCPY)) |
8b57bfeb JJ |
1513 | dsi->dont_invalidate = true; |
1514 | } | |
1515 | ||
1516 | if (si != NULL) | |
1517 | /* strcat src may not overlap dst, so src doesn't need to be | |
1518 | invalidated either. */ | |
1519 | si->dont_invalidate = true; | |
1520 | ||
1521 | /* For now. Could remove the lhs from the call and add | |
1522 | lhs = dst; afterwards. */ | |
1523 | if (lhs) | |
1524 | return; | |
1525 | ||
1526 | fn = NULL_TREE; | |
1527 | objsz = NULL_TREE; | |
1528 | switch (bcode) | |
1529 | { | |
1530 | case BUILT_IN_STRCAT: | |
1531 | if (srclen != NULL_TREE) | |
e79983f4 | 1532 | fn = builtin_decl_implicit (BUILT_IN_MEMCPY); |
8b57bfeb | 1533 | else |
e79983f4 | 1534 | fn = builtin_decl_implicit (BUILT_IN_STRCPY); |
8b57bfeb JJ |
1535 | break; |
1536 | case BUILT_IN_STRCAT_CHK: | |
1537 | if (srclen != NULL_TREE) | |
e79983f4 | 1538 | fn = builtin_decl_explicit (BUILT_IN_MEMCPY_CHK); |
8b57bfeb | 1539 | else |
e79983f4 | 1540 | fn = builtin_decl_explicit (BUILT_IN_STRCPY_CHK); |
8b57bfeb JJ |
1541 | objsz = gimple_call_arg (stmt, 2); |
1542 | break; | |
1543 | default: | |
1544 | gcc_unreachable (); | |
1545 | } | |
1546 | ||
1547 | if (fn == NULL_TREE) | |
1548 | return; | |
1549 | ||
1550 | len = NULL_TREE; | |
1551 | if (srclen != NULL_TREE) | |
1552 | { | |
1553 | args = TYPE_ARG_TYPES (TREE_TYPE (fn)); | |
1554 | type = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (args))); | |
1555 | ||
1556 | len = fold_convert_loc (loc, type, unshare_expr (srclen)); | |
1557 | len = fold_build2_loc (loc, PLUS_EXPR, type, len, | |
1558 | build_int_cst (type, 1)); | |
1559 | len = force_gimple_operand_gsi (gsi, len, true, NULL_TREE, true, | |
1560 | GSI_SAME_STMT); | |
1561 | } | |
1562 | if (endptr) | |
1563 | dst = fold_convert_loc (loc, TREE_TYPE (dst), unshare_expr (endptr)); | |
1564 | else | |
1565 | dst = fold_build2_loc (loc, POINTER_PLUS_EXPR, | |
1566 | TREE_TYPE (dst), unshare_expr (dst), | |
1567 | fold_convert_loc (loc, sizetype, | |
1568 | unshare_expr (dstlen))); | |
1569 | dst = force_gimple_operand_gsi (gsi, dst, true, NULL_TREE, true, | |
1570 | GSI_SAME_STMT); | |
1571 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1572 | { | |
1573 | fprintf (dump_file, "Optimizing: "); | |
1574 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1575 | } | |
1576 | if (srclen != NULL_TREE) | |
1577 | success = update_gimple_call (gsi, fn, 3 + (objsz != NULL_TREE), | |
1578 | dst, src, len, objsz); | |
1579 | else | |
1580 | success = update_gimple_call (gsi, fn, 2 + (objsz != NULL_TREE), | |
1581 | dst, src, objsz); | |
1582 | if (success) | |
1583 | { | |
1584 | stmt = gsi_stmt (*gsi); | |
1585 | update_stmt (stmt); | |
1586 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1587 | { | |
1588 | fprintf (dump_file, "into: "); | |
1589 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1590 | } | |
1591 | /* If srclen == NULL, note that current string length can be | |
1592 | computed by transforming this strcpy into stpcpy. */ | |
1593 | if (srclen == NULL_TREE && dsi->dont_invalidate) | |
1594 | dsi->stmt = stmt; | |
1595 | adjust_last_stmt (dsi, stmt, true); | |
1596 | if (srclen != NULL_TREE) | |
1597 | { | |
1598 | laststmt.stmt = stmt; | |
1599 | laststmt.len = srclen; | |
1600 | laststmt.stridx = dsi->idx; | |
1601 | } | |
1602 | } | |
1603 | else if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1604 | fprintf (dump_file, "not possible.\n"); | |
1605 | } | |
1606 | ||
1607 | /* Handle a POINTER_PLUS_EXPR statement. | |
1608 | For p = "abcd" + 2; compute associated length, or if | |
1609 | p = q + off is pointing to a '\0' character of a string, call | |
1610 | zero_length_string on it. */ | |
1611 | ||
1612 | static void | |
1613 | handle_pointer_plus (gimple_stmt_iterator *gsi) | |
1614 | { | |
1615 | gimple stmt = gsi_stmt (*gsi); | |
1616 | tree lhs = gimple_assign_lhs (stmt), off; | |
1617 | int idx = get_stridx (gimple_assign_rhs1 (stmt)); | |
1618 | strinfo si, zsi; | |
1619 | ||
1620 | if (idx == 0) | |
1621 | return; | |
1622 | ||
1623 | if (idx < 0) | |
1624 | { | |
1625 | tree off = gimple_assign_rhs2 (stmt); | |
1626 | if (host_integerp (off, 1) | |
1627 | && (unsigned HOST_WIDE_INT) tree_low_cst (off, 1) | |
1628 | <= (unsigned HOST_WIDE_INT) ~idx) | |
9771b263 DN |
1629 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] |
1630 | = ~(~idx - (int) tree_low_cst (off, 1)); | |
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 | } |