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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" | |
4a8fb1a1 | 24 | #include "hash-table.h" |
8b57bfeb JJ |
25 | #include "tree-flow.h" |
26 | #include "tree-pass.h" | |
27 | #include "domwalk.h" | |
28 | #include "alloc-pool.h" | |
29 | #include "tree-ssa-propagate.h" | |
30 | #include "gimple-pretty-print.h" | |
31 | #include "params.h" | |
b3c3685a | 32 | #include "expr.h" |
8b57bfeb JJ |
33 | |
34 | /* A vector indexed by SSA_NAME_VERSION. 0 means unknown, positive value | |
35 | is an index into strinfo vector, negative value stands for | |
36 | string length of a string literal (~strlen). */ | |
9771b263 | 37 | static vec<int> ssa_ver_to_stridx; |
8b57bfeb JJ |
38 | |
39 | /* Number of currently active string indexes plus one. */ | |
40 | static int max_stridx; | |
41 | ||
42 | /* String information record. */ | |
43 | typedef struct strinfo_struct | |
44 | { | |
45 | /* String length of this string. */ | |
46 | tree length; | |
47 | /* Any of the corresponding pointers for querying alias oracle. */ | |
48 | tree ptr; | |
49 | /* Statement for delayed length computation. */ | |
50 | gimple stmt; | |
51 | /* Pointer to '\0' if known, if NULL, it can be computed as | |
52 | ptr + length. */ | |
53 | tree endptr; | |
54 | /* Reference count. Any changes to strinfo entry possibly shared | |
55 | with dominating basic blocks need unshare_strinfo first, except | |
56 | for dont_invalidate which affects only the immediately next | |
57 | maybe_invalidate. */ | |
58 | int refcount; | |
59 | /* Copy of index. get_strinfo (si->idx) should return si; */ | |
60 | int idx; | |
61 | /* These 3 fields are for chaining related string pointers together. | |
62 | E.g. for | |
63 | bl = strlen (b); dl = strlen (d); strcpy (a, b); c = a + bl; | |
64 | strcpy (c, d); e = c + dl; | |
65 | strinfo(a) -> strinfo(c) -> strinfo(e) | |
66 | All have ->first field equal to strinfo(a)->idx and are doubly | |
67 | chained through prev/next fields. The later strinfos are required | |
68 | to point into the same string with zero or more bytes after | |
69 | the previous pointer and all bytes in between the two pointers | |
70 | must be non-zero. Functions like strcpy or memcpy are supposed | |
71 | to adjust all previous strinfo lengths, but not following strinfo | |
72 | lengths (those are uncertain, usually invalidated during | |
73 | maybe_invalidate, except when the alias oracle knows better). | |
74 | Functions like strcat on the other side adjust the whole | |
75 | related strinfo chain. | |
76 | They are updated lazily, so to use the chain the same first fields | |
77 | and si->prev->next == si->idx needs to be verified. */ | |
78 | int first; | |
79 | int next; | |
80 | int prev; | |
81 | /* A flag whether the string is known to be written in the current | |
82 | function. */ | |
83 | bool writable; | |
84 | /* A flag for the next maybe_invalidate that this strinfo shouldn't | |
85 | be invalidated. Always cleared by maybe_invalidate. */ | |
86 | bool dont_invalidate; | |
87 | } *strinfo; | |
8b57bfeb JJ |
88 | |
89 | /* Pool for allocating strinfo_struct entries. */ | |
90 | static alloc_pool strinfo_pool; | |
91 | ||
92 | /* Vector mapping positive string indexes to strinfo, for the | |
93 | current basic block. The first pointer in the vector is special, | |
94 | it is either NULL, meaning the vector isn't shared, or it is | |
95 | a basic block pointer to the owner basic_block if shared. | |
96 | If some other bb wants to modify the vector, the vector needs | |
97 | to be unshared first, and only the owner bb is supposed to free it. */ | |
9771b263 | 98 | static vec<strinfo, va_heap, vl_embed> *stridx_to_strinfo; |
8b57bfeb JJ |
99 | |
100 | /* One OFFSET->IDX mapping. */ | |
101 | struct stridxlist | |
102 | { | |
103 | struct stridxlist *next; | |
104 | HOST_WIDE_INT offset; | |
105 | int idx; | |
106 | }; | |
107 | ||
108 | /* Hash table entry, mapping a DECL to a chain of OFFSET->IDX mappings. */ | |
109 | struct decl_stridxlist_map | |
110 | { | |
111 | struct tree_map_base base; | |
112 | struct stridxlist list; | |
113 | }; | |
114 | ||
4a8fb1a1 LC |
115 | /* stridxlist hashtable helpers. */ |
116 | ||
117 | struct stridxlist_hasher : typed_noop_remove <decl_stridxlist_map> | |
118 | { | |
119 | typedef decl_stridxlist_map value_type; | |
120 | typedef decl_stridxlist_map compare_type; | |
121 | static inline hashval_t hash (const value_type *); | |
122 | static inline bool equal (const value_type *, const compare_type *); | |
123 | }; | |
124 | ||
125 | /* Hash a from tree in a decl_stridxlist_map. */ | |
126 | ||
127 | inline hashval_t | |
128 | stridxlist_hasher::hash (const value_type *item) | |
129 | { | |
130 | return DECL_UID (item->base.from); | |
131 | } | |
132 | ||
133 | inline bool | |
134 | stridxlist_hasher::equal (const value_type *v, const compare_type *c) | |
135 | { | |
136 | return tree_map_base_eq (&v->base, &c->base); | |
137 | } | |
138 | ||
8b57bfeb JJ |
139 | /* Hash table for mapping decls to a chained list of offset -> idx |
140 | mappings. */ | |
4a8fb1a1 | 141 | static hash_table <stridxlist_hasher> decl_to_stridxlist_htab; |
8b57bfeb JJ |
142 | |
143 | /* Obstack for struct stridxlist and struct decl_stridxlist_map. */ | |
144 | static struct obstack stridx_obstack; | |
145 | ||
146 | /* Last memcpy statement if it could be adjusted if the trailing | |
147 | '\0' written is immediately overwritten, or | |
148 | *x = '\0' store that could be removed if it is immediately overwritten. */ | |
149 | struct laststmt_struct | |
150 | { | |
151 | gimple stmt; | |
152 | tree len; | |
153 | int stridx; | |
154 | } laststmt; | |
155 | ||
8b57bfeb JJ |
156 | /* Helper function for get_stridx. */ |
157 | ||
158 | static int | |
159 | get_addr_stridx (tree exp) | |
160 | { | |
161 | HOST_WIDE_INT off; | |
162 | struct decl_stridxlist_map ent, *e; | |
163 | struct stridxlist *list; | |
164 | tree base; | |
165 | ||
4a8fb1a1 | 166 | if (!decl_to_stridxlist_htab.is_created ()) |
8b57bfeb JJ |
167 | return 0; |
168 | ||
169 | base = get_addr_base_and_unit_offset (exp, &off); | |
170 | if (base == NULL || !DECL_P (base)) | |
171 | return 0; | |
172 | ||
173 | ent.base.from = base; | |
4a8fb1a1 | 174 | e = decl_to_stridxlist_htab.find_with_hash (&ent, DECL_UID (base)); |
8b57bfeb JJ |
175 | if (e == NULL) |
176 | return 0; | |
177 | ||
178 | list = &e->list; | |
179 | do | |
180 | { | |
181 | if (list->offset == off) | |
182 | return list->idx; | |
183 | list = list->next; | |
184 | } | |
185 | while (list); | |
186 | return 0; | |
187 | } | |
188 | ||
189 | /* Return string index for EXP. */ | |
190 | ||
191 | static int | |
192 | get_stridx (tree exp) | |
193 | { | |
b3c3685a | 194 | tree s, o; |
8b57bfeb JJ |
195 | |
196 | if (TREE_CODE (exp) == SSA_NAME) | |
9771b263 | 197 | return ssa_ver_to_stridx[SSA_NAME_VERSION (exp)]; |
8b57bfeb JJ |
198 | |
199 | if (TREE_CODE (exp) == ADDR_EXPR) | |
200 | { | |
201 | int idx = get_addr_stridx (TREE_OPERAND (exp, 0)); | |
202 | if (idx != 0) | |
203 | return idx; | |
204 | } | |
205 | ||
b3c3685a JJ |
206 | s = string_constant (exp, &o); |
207 | if (s != NULL_TREE | |
208 | && (o == NULL_TREE || host_integerp (o, 0)) | |
209 | && TREE_STRING_LENGTH (s) > 0) | |
8b57bfeb | 210 | { |
b3c3685a JJ |
211 | HOST_WIDE_INT offset = o ? tree_low_cst (o, 0) : 0; |
212 | const char *p = TREE_STRING_POINTER (s); | |
213 | int max = TREE_STRING_LENGTH (s) - 1; | |
214 | ||
215 | if (p[max] == '\0' && offset >= 0 && offset <= max) | |
216 | return ~(int) strlen (p + offset); | |
8b57bfeb JJ |
217 | } |
218 | return 0; | |
219 | } | |
220 | ||
221 | /* Return true if strinfo vector is shared with the immediate dominator. */ | |
222 | ||
223 | static inline bool | |
224 | strinfo_shared (void) | |
225 | { | |
9771b263 DN |
226 | return vec_safe_length (stridx_to_strinfo) |
227 | && (*stridx_to_strinfo)[0] != NULL; | |
8b57bfeb JJ |
228 | } |
229 | ||
230 | /* Unshare strinfo vector that is shared with the immediate dominator. */ | |
231 | ||
232 | static void | |
233 | unshare_strinfo_vec (void) | |
234 | { | |
235 | strinfo si; | |
236 | unsigned int i = 0; | |
237 | ||
238 | gcc_assert (strinfo_shared ()); | |
9771b263 DN |
239 | stridx_to_strinfo = vec_safe_copy (stridx_to_strinfo); |
240 | for (i = 1; vec_safe_iterate (stridx_to_strinfo, i, &si); ++i) | |
8b57bfeb JJ |
241 | if (si != NULL) |
242 | si->refcount++; | |
9771b263 | 243 | (*stridx_to_strinfo)[0] = NULL; |
8b57bfeb JJ |
244 | } |
245 | ||
246 | /* Attempt to create a string index for exp, ADDR_EXPR's operand. | |
247 | Return a pointer to the location where the string index can | |
248 | be stored (if 0) or is stored, or NULL if this can't be tracked. */ | |
249 | ||
250 | static int * | |
251 | addr_stridxptr (tree exp) | |
252 | { | |
4a8fb1a1 | 253 | decl_stridxlist_map **slot; |
8b57bfeb JJ |
254 | struct decl_stridxlist_map ent; |
255 | struct stridxlist *list; | |
256 | HOST_WIDE_INT off; | |
257 | ||
258 | tree base = get_addr_base_and_unit_offset (exp, &off); | |
259 | if (base == NULL_TREE || !DECL_P (base)) | |
260 | return NULL; | |
261 | ||
4a8fb1a1 | 262 | if (!decl_to_stridxlist_htab.is_created ()) |
8b57bfeb | 263 | { |
4a8fb1a1 | 264 | decl_to_stridxlist_htab.create (64); |
8b57bfeb JJ |
265 | gcc_obstack_init (&stridx_obstack); |
266 | } | |
267 | ent.base.from = base; | |
4a8fb1a1 LC |
268 | slot = decl_to_stridxlist_htab.find_slot_with_hash (&ent, DECL_UID (base), |
269 | INSERT); | |
8b57bfeb JJ |
270 | if (*slot) |
271 | { | |
272 | int i; | |
4a8fb1a1 | 273 | list = &(*slot)->list; |
8b57bfeb JJ |
274 | for (i = 0; i < 16; i++) |
275 | { | |
276 | if (list->offset == off) | |
277 | return &list->idx; | |
278 | if (list->next == NULL) | |
279 | break; | |
280 | } | |
281 | if (i == 16) | |
282 | return NULL; | |
283 | list->next = XOBNEW (&stridx_obstack, struct stridxlist); | |
284 | list = list->next; | |
285 | } | |
286 | else | |
287 | { | |
288 | struct decl_stridxlist_map *e | |
289 | = XOBNEW (&stridx_obstack, struct decl_stridxlist_map); | |
290 | e->base.from = base; | |
4a8fb1a1 | 291 | *slot = e; |
8b57bfeb JJ |
292 | list = &e->list; |
293 | } | |
294 | list->next = NULL; | |
295 | list->offset = off; | |
296 | list->idx = 0; | |
297 | return &list->idx; | |
298 | } | |
299 | ||
300 | /* Create a new string index, or return 0 if reached limit. */ | |
301 | ||
302 | static int | |
303 | new_stridx (tree exp) | |
304 | { | |
305 | int idx; | |
306 | if (max_stridx >= PARAM_VALUE (PARAM_MAX_TRACKED_STRLENS)) | |
307 | return 0; | |
308 | if (TREE_CODE (exp) == SSA_NAME) | |
309 | { | |
310 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (exp)) | |
311 | return 0; | |
312 | idx = max_stridx++; | |
9771b263 | 313 | ssa_ver_to_stridx[SSA_NAME_VERSION (exp)] = idx; |
8b57bfeb JJ |
314 | return idx; |
315 | } | |
316 | if (TREE_CODE (exp) == ADDR_EXPR) | |
317 | { | |
318 | int *pidx = addr_stridxptr (TREE_OPERAND (exp, 0)); | |
319 | if (pidx != NULL) | |
320 | { | |
321 | gcc_assert (*pidx == 0); | |
322 | *pidx = max_stridx++; | |
323 | return *pidx; | |
324 | } | |
325 | } | |
326 | return 0; | |
327 | } | |
328 | ||
329 | /* Like new_stridx, but for ADDR_EXPR's operand instead. */ | |
330 | ||
331 | static int | |
332 | new_addr_stridx (tree exp) | |
333 | { | |
334 | int *pidx; | |
335 | if (max_stridx >= PARAM_VALUE (PARAM_MAX_TRACKED_STRLENS)) | |
336 | return 0; | |
337 | pidx = addr_stridxptr (exp); | |
338 | if (pidx != NULL) | |
339 | { | |
340 | gcc_assert (*pidx == 0); | |
341 | *pidx = max_stridx++; | |
342 | return *pidx; | |
343 | } | |
344 | return 0; | |
345 | } | |
346 | ||
347 | /* Create a new strinfo. */ | |
348 | ||
349 | static strinfo | |
350 | new_strinfo (tree ptr, int idx, tree length) | |
351 | { | |
352 | strinfo si = (strinfo) pool_alloc (strinfo_pool); | |
353 | si->length = length; | |
354 | si->ptr = ptr; | |
355 | si->stmt = NULL; | |
356 | si->endptr = NULL_TREE; | |
357 | si->refcount = 1; | |
358 | si->idx = idx; | |
359 | si->first = 0; | |
360 | si->prev = 0; | |
361 | si->next = 0; | |
362 | si->writable = false; | |
363 | si->dont_invalidate = false; | |
364 | return si; | |
365 | } | |
366 | ||
367 | /* Decrease strinfo refcount and free it if not referenced anymore. */ | |
368 | ||
369 | static inline void | |
370 | free_strinfo (strinfo si) | |
371 | { | |
372 | if (si && --si->refcount == 0) | |
373 | pool_free (strinfo_pool, si); | |
374 | } | |
375 | ||
376 | /* Return strinfo vector entry IDX. */ | |
377 | ||
378 | static inline strinfo | |
379 | get_strinfo (int idx) | |
380 | { | |
9771b263 | 381 | if (vec_safe_length (stridx_to_strinfo) <= (unsigned int) idx) |
8b57bfeb | 382 | return NULL; |
9771b263 | 383 | return (*stridx_to_strinfo)[idx]; |
8b57bfeb JJ |
384 | } |
385 | ||
386 | /* Set strinfo in the vector entry IDX to SI. */ | |
387 | ||
388 | static inline void | |
389 | set_strinfo (int idx, strinfo si) | |
390 | { | |
9771b263 | 391 | if (vec_safe_length (stridx_to_strinfo) && (*stridx_to_strinfo)[0]) |
8b57bfeb | 392 | unshare_strinfo_vec (); |
9771b263 DN |
393 | if (vec_safe_length (stridx_to_strinfo) <= (unsigned int) idx) |
394 | vec_safe_grow_cleared (stridx_to_strinfo, idx + 1); | |
395 | (*stridx_to_strinfo)[idx] = si; | |
8b57bfeb JJ |
396 | } |
397 | ||
398 | /* Return string length, or NULL if it can't be computed. */ | |
399 | ||
400 | static tree | |
401 | get_string_length (strinfo si) | |
402 | { | |
403 | if (si->length) | |
404 | return si->length; | |
405 | ||
406 | if (si->stmt) | |
407 | { | |
408 | gimple stmt = si->stmt, lenstmt; | |
83d5977e | 409 | tree callee, lhs, fn, tem; |
8b57bfeb JJ |
410 | location_t loc; |
411 | gimple_stmt_iterator gsi; | |
412 | ||
413 | gcc_assert (is_gimple_call (stmt)); | |
414 | callee = gimple_call_fndecl (stmt); | |
415 | gcc_assert (callee && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL); | |
416 | lhs = gimple_call_lhs (stmt); | |
93a90db6 | 417 | gcc_assert (builtin_decl_implicit_p (BUILT_IN_STPCPY)); |
8b57bfeb JJ |
418 | /* unshare_strinfo is intentionally not called here. The (delayed) |
419 | transformation of strcpy or strcat into stpcpy is done at the place | |
420 | of the former strcpy/strcat call and so can affect all the strinfos | |
421 | with the same stmt. If they were unshared before and transformation | |
422 | has been already done, the handling of BUILT_IN_STPCPY{,_CHK} should | |
423 | just compute the right length. */ | |
424 | switch (DECL_FUNCTION_CODE (callee)) | |
425 | { | |
426 | case BUILT_IN_STRCAT: | |
427 | case BUILT_IN_STRCAT_CHK: | |
428 | gsi = gsi_for_stmt (stmt); | |
e79983f4 | 429 | fn = builtin_decl_implicit (BUILT_IN_STRLEN); |
8b57bfeb | 430 | gcc_assert (lhs == NULL_TREE); |
8b57bfeb JJ |
431 | tem = unshare_expr (gimple_call_arg (stmt, 0)); |
432 | lenstmt = gimple_build_call (fn, 1, tem); | |
83d5977e | 433 | lhs = make_ssa_name (TREE_TYPE (TREE_TYPE (fn)), lenstmt); |
8b57bfeb JJ |
434 | gimple_call_set_lhs (lenstmt, lhs); |
435 | gimple_set_vuse (lenstmt, gimple_vuse (stmt)); | |
436 | gsi_insert_before (&gsi, lenstmt, GSI_SAME_STMT); | |
8b57bfeb | 437 | tem = gimple_call_arg (stmt, 0); |
33960e2e TG |
438 | if (!ptrofftype_p (TREE_TYPE (lhs))) |
439 | { | |
440 | lhs = convert_to_ptrofftype (lhs); | |
441 | lhs = force_gimple_operand_gsi (&gsi, lhs, true, NULL_TREE, | |
442 | true, GSI_SAME_STMT); | |
443 | } | |
8b57bfeb | 444 | lenstmt |
83d5977e RG |
445 | = gimple_build_assign_with_ops |
446 | (POINTER_PLUS_EXPR, | |
447 | make_ssa_name (TREE_TYPE (gimple_call_arg (stmt, 0)), NULL), | |
448 | tem, lhs); | |
8b57bfeb JJ |
449 | gsi_insert_before (&gsi, lenstmt, GSI_SAME_STMT); |
450 | gimple_call_set_arg (stmt, 0, gimple_assign_lhs (lenstmt)); | |
451 | lhs = NULL_TREE; | |
452 | /* FALLTHRU */ | |
453 | case BUILT_IN_STRCPY: | |
454 | case BUILT_IN_STRCPY_CHK: | |
455 | if (gimple_call_num_args (stmt) == 2) | |
e79983f4 | 456 | fn = builtin_decl_implicit (BUILT_IN_STPCPY); |
8b57bfeb | 457 | else |
e79983f4 | 458 | fn = builtin_decl_explicit (BUILT_IN_STPCPY_CHK); |
8b57bfeb JJ |
459 | gcc_assert (lhs == NULL_TREE); |
460 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
461 | { | |
462 | fprintf (dump_file, "Optimizing: "); | |
463 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
464 | } | |
465 | gimple_call_set_fndecl (stmt, fn); | |
83d5977e | 466 | lhs = make_ssa_name (TREE_TYPE (TREE_TYPE (fn)), stmt); |
8b57bfeb JJ |
467 | gimple_call_set_lhs (stmt, lhs); |
468 | update_stmt (stmt); | |
469 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
470 | { | |
471 | fprintf (dump_file, "into: "); | |
472 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
473 | } | |
474 | /* FALLTHRU */ | |
475 | case BUILT_IN_STPCPY: | |
476 | case BUILT_IN_STPCPY_CHK: | |
477 | gcc_assert (lhs != NULL_TREE); | |
478 | loc = gimple_location (stmt); | |
479 | si->endptr = lhs; | |
480 | si->stmt = NULL; | |
481 | lhs = fold_convert_loc (loc, size_type_node, lhs); | |
482 | si->length = fold_convert_loc (loc, size_type_node, si->ptr); | |
483 | si->length = fold_build2_loc (loc, MINUS_EXPR, size_type_node, | |
484 | lhs, si->length); | |
485 | break; | |
486 | default: | |
487 | gcc_unreachable (); | |
488 | break; | |
489 | } | |
490 | } | |
491 | ||
492 | return si->length; | |
493 | } | |
494 | ||
495 | /* Invalidate string length information for strings whose length | |
496 | might change due to stores in stmt. */ | |
497 | ||
498 | static bool | |
499 | maybe_invalidate (gimple stmt) | |
500 | { | |
501 | strinfo si; | |
502 | unsigned int i; | |
503 | bool nonempty = false; | |
504 | ||
9771b263 | 505 | for (i = 1; vec_safe_iterate (stridx_to_strinfo, i, &si); ++i) |
8b57bfeb JJ |
506 | if (si != NULL) |
507 | { | |
508 | if (!si->dont_invalidate) | |
509 | { | |
510 | ao_ref r; | |
511 | ao_ref_init_from_ptr_and_size (&r, si->ptr, NULL_TREE); | |
512 | if (stmt_may_clobber_ref_p_1 (stmt, &r)) | |
513 | { | |
514 | set_strinfo (i, NULL); | |
515 | free_strinfo (si); | |
516 | continue; | |
517 | } | |
518 | } | |
519 | si->dont_invalidate = false; | |
520 | nonempty = true; | |
521 | } | |
522 | return nonempty; | |
523 | } | |
524 | ||
525 | /* Unshare strinfo record SI, if it has recount > 1 or | |
526 | if stridx_to_strinfo vector is shared with some other | |
527 | bbs. */ | |
528 | ||
529 | static strinfo | |
530 | unshare_strinfo (strinfo si) | |
531 | { | |
532 | strinfo nsi; | |
533 | ||
534 | if (si->refcount == 1 && !strinfo_shared ()) | |
535 | return si; | |
536 | ||
537 | nsi = new_strinfo (si->ptr, si->idx, si->length); | |
538 | nsi->stmt = si->stmt; | |
539 | nsi->endptr = si->endptr; | |
540 | nsi->first = si->first; | |
541 | nsi->prev = si->prev; | |
542 | nsi->next = si->next; | |
543 | nsi->writable = si->writable; | |
544 | set_strinfo (si->idx, nsi); | |
545 | free_strinfo (si); | |
546 | return nsi; | |
547 | } | |
548 | ||
549 | /* Return first strinfo in the related strinfo chain | |
550 | if all strinfos in between belong to the chain, otherwise | |
551 | NULL. */ | |
552 | ||
553 | static strinfo | |
554 | verify_related_strinfos (strinfo origsi) | |
555 | { | |
556 | strinfo si = origsi, psi; | |
557 | ||
558 | if (origsi->first == 0) | |
559 | return NULL; | |
560 | for (; si->prev; si = psi) | |
561 | { | |
562 | if (si->first != origsi->first) | |
563 | return NULL; | |
564 | psi = get_strinfo (si->prev); | |
565 | if (psi == NULL) | |
566 | return NULL; | |
567 | if (psi->next != si->idx) | |
568 | return NULL; | |
569 | } | |
570 | if (si->idx != si->first) | |
571 | return NULL; | |
572 | return si; | |
573 | } | |
574 | ||
575 | /* Note that PTR, a pointer SSA_NAME initialized in the current stmt, points | |
576 | to a zero-length string and if possible chain it to a related strinfo | |
577 | chain whose part is or might be CHAINSI. */ | |
578 | ||
579 | static strinfo | |
580 | zero_length_string (tree ptr, strinfo chainsi) | |
581 | { | |
582 | strinfo si; | |
583 | int idx; | |
584 | gcc_checking_assert (TREE_CODE (ptr) == SSA_NAME | |
585 | && get_stridx (ptr) == 0); | |
586 | ||
587 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ptr)) | |
588 | return NULL; | |
589 | if (chainsi != NULL) | |
590 | { | |
591 | si = verify_related_strinfos (chainsi); | |
592 | if (si) | |
593 | { | |
594 | chainsi = si; | |
595 | for (; chainsi->next; chainsi = si) | |
596 | { | |
597 | if (chainsi->endptr == NULL_TREE) | |
598 | { | |
599 | chainsi = unshare_strinfo (chainsi); | |
600 | chainsi->endptr = ptr; | |
601 | } | |
602 | si = get_strinfo (chainsi->next); | |
603 | if (si == NULL | |
604 | || si->first != chainsi->first | |
605 | || si->prev != chainsi->idx) | |
606 | break; | |
607 | } | |
93a90db6 | 608 | gcc_assert (chainsi->length || chainsi->stmt); |
8b57bfeb JJ |
609 | if (chainsi->endptr == NULL_TREE) |
610 | { | |
611 | chainsi = unshare_strinfo (chainsi); | |
612 | chainsi->endptr = ptr; | |
613 | } | |
93a90db6 | 614 | if (chainsi->length && integer_zerop (chainsi->length)) |
8b57bfeb JJ |
615 | { |
616 | if (chainsi->next) | |
617 | { | |
618 | chainsi = unshare_strinfo (chainsi); | |
619 | chainsi->next = 0; | |
620 | } | |
9771b263 | 621 | ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] = chainsi->idx; |
8b57bfeb JJ |
622 | return chainsi; |
623 | } | |
624 | } | |
625 | else if (chainsi->first || chainsi->prev || chainsi->next) | |
626 | { | |
627 | chainsi = unshare_strinfo (chainsi); | |
628 | chainsi->first = 0; | |
629 | chainsi->prev = 0; | |
630 | chainsi->next = 0; | |
631 | } | |
632 | } | |
633 | idx = new_stridx (ptr); | |
634 | if (idx == 0) | |
635 | return NULL; | |
636 | si = new_strinfo (ptr, idx, build_int_cst (size_type_node, 0)); | |
637 | set_strinfo (idx, si); | |
638 | si->endptr = ptr; | |
639 | if (chainsi != NULL) | |
640 | { | |
641 | chainsi = unshare_strinfo (chainsi); | |
642 | if (chainsi->first == 0) | |
643 | chainsi->first = chainsi->idx; | |
644 | chainsi->next = idx; | |
93a90db6 AK |
645 | if (chainsi->endptr == NULL_TREE) |
646 | chainsi->endptr = ptr; | |
8b57bfeb JJ |
647 | si->prev = chainsi->idx; |
648 | si->first = chainsi->first; | |
649 | si->writable = chainsi->writable; | |
650 | } | |
651 | return si; | |
652 | } | |
653 | ||
654 | /* For strinfo ORIGSI whose length has been just updated | |
655 | update also related strinfo lengths (add ADJ to each, | |
656 | but don't adjust ORIGSI). */ | |
657 | ||
658 | static void | |
659 | adjust_related_strinfos (location_t loc, strinfo origsi, tree adj) | |
660 | { | |
661 | strinfo si = verify_related_strinfos (origsi); | |
662 | ||
663 | if (si == NULL) | |
664 | return; | |
665 | ||
666 | while (1) | |
667 | { | |
668 | strinfo nsi; | |
669 | ||
670 | if (si != origsi) | |
671 | { | |
672 | tree tem; | |
673 | ||
674 | si = unshare_strinfo (si); | |
93a90db6 AK |
675 | if (si->length) |
676 | { | |
677 | tem = fold_convert_loc (loc, TREE_TYPE (si->length), adj); | |
678 | si->length = fold_build2_loc (loc, PLUS_EXPR, | |
679 | TREE_TYPE (si->length), si->length, | |
680 | tem); | |
681 | } | |
682 | else if (si->stmt != NULL) | |
683 | /* Delayed length computation is unaffected. */ | |
684 | ; | |
685 | else | |
686 | gcc_unreachable (); | |
687 | ||
8b57bfeb JJ |
688 | si->endptr = NULL_TREE; |
689 | si->dont_invalidate = true; | |
690 | } | |
691 | if (si->next == 0) | |
692 | return; | |
693 | nsi = get_strinfo (si->next); | |
694 | if (nsi == NULL | |
695 | || nsi->first != si->first | |
696 | || nsi->prev != si->idx) | |
697 | return; | |
698 | si = nsi; | |
699 | } | |
700 | } | |
701 | ||
702 | /* Find if there are other SSA_NAME pointers equal to PTR | |
703 | for which we don't track their string lengths yet. If so, use | |
704 | IDX for them. */ | |
705 | ||
706 | static void | |
707 | find_equal_ptrs (tree ptr, int idx) | |
708 | { | |
709 | if (TREE_CODE (ptr) != SSA_NAME) | |
710 | return; | |
711 | while (1) | |
712 | { | |
713 | gimple stmt = SSA_NAME_DEF_STMT (ptr); | |
714 | if (!is_gimple_assign (stmt)) | |
715 | return; | |
716 | ptr = gimple_assign_rhs1 (stmt); | |
717 | switch (gimple_assign_rhs_code (stmt)) | |
718 | { | |
719 | case SSA_NAME: | |
720 | break; | |
97246d78 JJ |
721 | CASE_CONVERT: |
722 | if (!POINTER_TYPE_P (TREE_TYPE (ptr))) | |
723 | return; | |
724 | if (TREE_CODE (ptr) == SSA_NAME) | |
725 | break; | |
726 | if (TREE_CODE (ptr) != ADDR_EXPR) | |
727 | return; | |
728 | /* FALLTHRU */ | |
8b57bfeb JJ |
729 | case ADDR_EXPR: |
730 | { | |
731 | int *pidx = addr_stridxptr (TREE_OPERAND (ptr, 0)); | |
732 | if (pidx != NULL && *pidx == 0) | |
733 | *pidx = idx; | |
734 | return; | |
735 | } | |
8b57bfeb JJ |
736 | default: |
737 | return; | |
738 | } | |
739 | ||
740 | /* We might find an endptr created in this pass. Grow the | |
741 | vector in that case. */ | |
9771b263 DN |
742 | if (ssa_ver_to_stridx.length () <= SSA_NAME_VERSION (ptr)) |
743 | ssa_ver_to_stridx.safe_grow_cleared (num_ssa_names); | |
8b57bfeb | 744 | |
9771b263 | 745 | if (ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] != 0) |
8b57bfeb | 746 | return; |
9771b263 | 747 | ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] = idx; |
8b57bfeb JJ |
748 | } |
749 | } | |
750 | ||
751 | /* If the last .MEM setter statement before STMT is | |
752 | memcpy (x, y, strlen (y) + 1), the only .MEM use of it is STMT | |
753 | and STMT is known to overwrite x[strlen (x)], adjust the last memcpy to | |
754 | just memcpy (x, y, strlen (y)). SI must be the zero length | |
755 | strinfo. */ | |
756 | ||
757 | static void | |
758 | adjust_last_stmt (strinfo si, gimple stmt, bool is_strcat) | |
759 | { | |
760 | tree vuse, callee, len; | |
761 | struct laststmt_struct last = laststmt; | |
762 | strinfo lastsi, firstsi; | |
763 | ||
764 | laststmt.stmt = NULL; | |
765 | laststmt.len = NULL_TREE; | |
766 | laststmt.stridx = 0; | |
767 | ||
768 | if (last.stmt == NULL) | |
769 | return; | |
770 | ||
771 | vuse = gimple_vuse (stmt); | |
772 | if (vuse == NULL_TREE | |
773 | || SSA_NAME_DEF_STMT (vuse) != last.stmt | |
774 | || !has_single_use (vuse)) | |
775 | return; | |
776 | ||
777 | gcc_assert (last.stridx > 0); | |
778 | lastsi = get_strinfo (last.stridx); | |
779 | if (lastsi == NULL) | |
780 | return; | |
781 | ||
782 | if (lastsi != si) | |
783 | { | |
784 | if (lastsi->first == 0 || lastsi->first != si->first) | |
785 | return; | |
786 | ||
787 | firstsi = verify_related_strinfos (si); | |
788 | if (firstsi == NULL) | |
789 | return; | |
790 | while (firstsi != lastsi) | |
791 | { | |
792 | strinfo nextsi; | |
793 | if (firstsi->next == 0) | |
794 | return; | |
795 | nextsi = get_strinfo (firstsi->next); | |
796 | if (nextsi == NULL | |
797 | || nextsi->prev != firstsi->idx | |
798 | || nextsi->first != si->first) | |
799 | return; | |
800 | firstsi = nextsi; | |
801 | } | |
802 | } | |
803 | ||
804 | if (!is_strcat) | |
805 | { | |
806 | if (si->length == NULL_TREE || !integer_zerop (si->length)) | |
807 | return; | |
808 | } | |
809 | ||
810 | if (is_gimple_assign (last.stmt)) | |
811 | { | |
812 | gimple_stmt_iterator gsi; | |
813 | ||
814 | if (!integer_zerop (gimple_assign_rhs1 (last.stmt))) | |
815 | return; | |
816 | if (stmt_could_throw_p (last.stmt)) | |
817 | return; | |
818 | gsi = gsi_for_stmt (last.stmt); | |
819 | unlink_stmt_vdef (last.stmt); | |
820 | release_defs (last.stmt); | |
821 | gsi_remove (&gsi, true); | |
822 | return; | |
823 | } | |
824 | ||
3626621a | 825 | if (!gimple_call_builtin_p (last.stmt, BUILT_IN_NORMAL)) |
8b57bfeb JJ |
826 | return; |
827 | ||
3626621a | 828 | callee = gimple_call_fndecl (last.stmt); |
8b57bfeb JJ |
829 | switch (DECL_FUNCTION_CODE (callee)) |
830 | { | |
831 | case BUILT_IN_MEMCPY: | |
832 | case BUILT_IN_MEMCPY_CHK: | |
833 | break; | |
834 | default: | |
835 | return; | |
836 | } | |
837 | ||
838 | len = gimple_call_arg (last.stmt, 2); | |
839 | if (host_integerp (len, 1)) | |
840 | { | |
841 | if (!host_integerp (last.len, 1) | |
842 | || integer_zerop (len) | |
843 | || (unsigned HOST_WIDE_INT) tree_low_cst (len, 1) | |
844 | != (unsigned HOST_WIDE_INT) tree_low_cst (last.len, 1) + 1) | |
845 | return; | |
846 | /* Don't adjust the length if it is divisible by 4, it is more efficient | |
847 | to store the extra '\0' in that case. */ | |
848 | if ((((unsigned HOST_WIDE_INT) tree_low_cst (len, 1)) & 3) == 0) | |
849 | return; | |
850 | } | |
851 | else if (TREE_CODE (len) == SSA_NAME) | |
852 | { | |
853 | gimple def_stmt = SSA_NAME_DEF_STMT (len); | |
854 | if (!is_gimple_assign (def_stmt) | |
855 | || gimple_assign_rhs_code (def_stmt) != PLUS_EXPR | |
856 | || gimple_assign_rhs1 (def_stmt) != last.len | |
857 | || !integer_onep (gimple_assign_rhs2 (def_stmt))) | |
858 | return; | |
859 | } | |
860 | else | |
861 | return; | |
862 | ||
863 | gimple_call_set_arg (last.stmt, 2, last.len); | |
864 | update_stmt (last.stmt); | |
865 | } | |
866 | ||
867 | /* Handle a strlen call. If strlen of the argument is known, replace | |
868 | the strlen call with the known value, otherwise remember that strlen | |
869 | of the argument is stored in the lhs SSA_NAME. */ | |
870 | ||
871 | static void | |
872 | handle_builtin_strlen (gimple_stmt_iterator *gsi) | |
873 | { | |
874 | int idx; | |
875 | tree src; | |
876 | gimple stmt = gsi_stmt (*gsi); | |
877 | tree lhs = gimple_call_lhs (stmt); | |
878 | ||
879 | if (lhs == NULL_TREE) | |
880 | return; | |
881 | ||
882 | src = gimple_call_arg (stmt, 0); | |
883 | idx = get_stridx (src); | |
884 | if (idx) | |
885 | { | |
886 | strinfo si = NULL; | |
887 | tree rhs; | |
888 | ||
889 | if (idx < 0) | |
890 | rhs = build_int_cst (TREE_TYPE (lhs), ~idx); | |
891 | else | |
892 | { | |
893 | rhs = NULL_TREE; | |
894 | si = get_strinfo (idx); | |
895 | if (si != NULL) | |
896 | rhs = get_string_length (si); | |
897 | } | |
898 | if (rhs != NULL_TREE) | |
899 | { | |
900 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
901 | { | |
902 | fprintf (dump_file, "Optimizing: "); | |
903 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
904 | } | |
905 | rhs = unshare_expr (rhs); | |
906 | if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs))) | |
907 | rhs = fold_convert_loc (gimple_location (stmt), | |
908 | TREE_TYPE (lhs), rhs); | |
909 | if (!update_call_from_tree (gsi, rhs)) | |
910 | gimplify_and_update_call_from_tree (gsi, rhs); | |
911 | stmt = gsi_stmt (*gsi); | |
912 | update_stmt (stmt); | |
913 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
914 | { | |
915 | fprintf (dump_file, "into: "); | |
916 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
917 | } | |
918 | if (si != NULL | |
919 | && TREE_CODE (si->length) != SSA_NAME | |
920 | && TREE_CODE (si->length) != INTEGER_CST | |
921 | && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
922 | { | |
923 | si = unshare_strinfo (si); | |
924 | si->length = lhs; | |
925 | } | |
926 | return; | |
927 | } | |
928 | } | |
929 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
930 | return; | |
931 | if (idx == 0) | |
932 | idx = new_stridx (src); | |
933 | else if (get_strinfo (idx) != NULL) | |
934 | return; | |
935 | if (idx) | |
936 | { | |
937 | strinfo si = new_strinfo (src, idx, lhs); | |
938 | set_strinfo (idx, si); | |
939 | find_equal_ptrs (src, idx); | |
940 | } | |
941 | } | |
942 | ||
943 | /* Handle a strchr call. If strlen of the first argument is known, replace | |
944 | the strchr (x, 0) call with the endptr or x + strlen, otherwise remember | |
945 | that lhs of the call is endptr and strlen of the argument is endptr - x. */ | |
946 | ||
947 | static void | |
948 | handle_builtin_strchr (gimple_stmt_iterator *gsi) | |
949 | { | |
950 | int idx; | |
951 | tree src; | |
952 | gimple stmt = gsi_stmt (*gsi); | |
953 | tree lhs = gimple_call_lhs (stmt); | |
954 | ||
955 | if (lhs == NULL_TREE) | |
956 | return; | |
957 | ||
958 | if (!integer_zerop (gimple_call_arg (stmt, 1))) | |
959 | return; | |
960 | ||
961 | src = gimple_call_arg (stmt, 0); | |
962 | idx = get_stridx (src); | |
963 | if (idx) | |
964 | { | |
965 | strinfo si = NULL; | |
966 | tree rhs; | |
967 | ||
968 | if (idx < 0) | |
969 | rhs = build_int_cst (size_type_node, ~idx); | |
970 | else | |
971 | { | |
972 | rhs = NULL_TREE; | |
973 | si = get_strinfo (idx); | |
974 | if (si != NULL) | |
975 | rhs = get_string_length (si); | |
976 | } | |
977 | if (rhs != NULL_TREE) | |
978 | { | |
979 | location_t loc = gimple_location (stmt); | |
980 | ||
981 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
982 | { | |
983 | fprintf (dump_file, "Optimizing: "); | |
984 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
985 | } | |
986 | if (si != NULL && si->endptr != NULL_TREE) | |
987 | { | |
988 | rhs = unshare_expr (si->endptr); | |
989 | if (!useless_type_conversion_p (TREE_TYPE (lhs), | |
990 | TREE_TYPE (rhs))) | |
991 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); | |
992 | } | |
993 | else | |
994 | { | |
995 | rhs = fold_convert_loc (loc, sizetype, unshare_expr (rhs)); | |
996 | rhs = fold_build2_loc (loc, POINTER_PLUS_EXPR, | |
997 | TREE_TYPE (src), src, rhs); | |
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 | if (!update_call_from_tree (gsi, rhs)) | |
1003 | gimplify_and_update_call_from_tree (gsi, rhs); | |
1004 | stmt = gsi_stmt (*gsi); | |
1005 | update_stmt (stmt); | |
1006 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1007 | { | |
1008 | fprintf (dump_file, "into: "); | |
1009 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1010 | } | |
1011 | if (si != NULL | |
1012 | && si->endptr == NULL_TREE | |
1013 | && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
1014 | { | |
1015 | si = unshare_strinfo (si); | |
1016 | si->endptr = lhs; | |
1017 | } | |
1018 | zero_length_string (lhs, si); | |
1019 | return; | |
1020 | } | |
1021 | } | |
1022 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
1023 | return; | |
1024 | if (TREE_CODE (src) != SSA_NAME || !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (src)) | |
1025 | { | |
1026 | if (idx == 0) | |
1027 | idx = new_stridx (src); | |
1028 | else if (get_strinfo (idx) != NULL) | |
1029 | { | |
1030 | zero_length_string (lhs, NULL); | |
1031 | return; | |
1032 | } | |
1033 | if (idx) | |
1034 | { | |
1035 | location_t loc = gimple_location (stmt); | |
1036 | tree lhsu = fold_convert_loc (loc, size_type_node, lhs); | |
1037 | tree srcu = fold_convert_loc (loc, size_type_node, src); | |
1038 | tree length = fold_build2_loc (loc, MINUS_EXPR, | |
1039 | size_type_node, lhsu, srcu); | |
1040 | strinfo si = new_strinfo (src, idx, length); | |
1041 | si->endptr = lhs; | |
1042 | set_strinfo (idx, si); | |
1043 | find_equal_ptrs (src, idx); | |
1044 | zero_length_string (lhs, si); | |
1045 | } | |
1046 | } | |
1047 | else | |
1048 | zero_length_string (lhs, NULL); | |
1049 | } | |
1050 | ||
1051 | /* Handle a strcpy-like ({st{r,p}cpy,__st{r,p}cpy_chk}) call. | |
1052 | If strlen of the second argument is known, strlen of the first argument | |
1053 | is the same after this call. Furthermore, attempt to convert it to | |
1054 | memcpy. */ | |
1055 | ||
1056 | static void | |
1057 | handle_builtin_strcpy (enum built_in_function bcode, gimple_stmt_iterator *gsi) | |
1058 | { | |
1059 | int idx, didx; | |
1060 | tree src, dst, srclen, len, lhs, args, type, fn, oldlen; | |
1061 | bool success; | |
1062 | gimple stmt = gsi_stmt (*gsi); | |
1063 | strinfo si, dsi, olddsi, zsi; | |
1064 | location_t loc; | |
1065 | ||
1066 | src = gimple_call_arg (stmt, 1); | |
1067 | dst = gimple_call_arg (stmt, 0); | |
1068 | lhs = gimple_call_lhs (stmt); | |
1069 | idx = get_stridx (src); | |
1070 | si = NULL; | |
1071 | if (idx > 0) | |
1072 | si = get_strinfo (idx); | |
1073 | ||
1074 | didx = get_stridx (dst); | |
1075 | olddsi = NULL; | |
1076 | oldlen = NULL_TREE; | |
1077 | if (didx > 0) | |
1078 | olddsi = get_strinfo (didx); | |
1079 | else if (didx < 0) | |
1080 | return; | |
1081 | ||
1082 | if (olddsi != NULL) | |
1083 | adjust_last_stmt (olddsi, stmt, false); | |
1084 | ||
1085 | srclen = NULL_TREE; | |
1086 | if (si != NULL) | |
1087 | srclen = get_string_length (si); | |
1088 | else if (idx < 0) | |
1089 | srclen = build_int_cst (size_type_node, ~idx); | |
1090 | ||
1091 | loc = gimple_location (stmt); | |
1092 | if (srclen == NULL_TREE) | |
1093 | switch (bcode) | |
1094 | { | |
1095 | case BUILT_IN_STRCPY: | |
1096 | case BUILT_IN_STRCPY_CHK: | |
e79983f4 | 1097 | if (lhs != NULL_TREE || !builtin_decl_implicit_p (BUILT_IN_STPCPY)) |
8b57bfeb JJ |
1098 | return; |
1099 | break; | |
1100 | case BUILT_IN_STPCPY: | |
1101 | case BUILT_IN_STPCPY_CHK: | |
1102 | if (lhs == NULL_TREE) | |
1103 | return; | |
1104 | else | |
1105 | { | |
1106 | tree lhsuint = fold_convert_loc (loc, size_type_node, lhs); | |
1107 | srclen = fold_convert_loc (loc, size_type_node, dst); | |
1108 | srclen = fold_build2_loc (loc, MINUS_EXPR, size_type_node, | |
1109 | lhsuint, srclen); | |
1110 | } | |
1111 | break; | |
1112 | default: | |
1113 | gcc_unreachable (); | |
1114 | } | |
1115 | ||
1116 | if (didx == 0) | |
1117 | { | |
1118 | didx = new_stridx (dst); | |
1119 | if (didx == 0) | |
1120 | return; | |
1121 | } | |
1122 | if (olddsi != NULL) | |
1123 | { | |
1124 | oldlen = olddsi->length; | |
1125 | dsi = unshare_strinfo (olddsi); | |
1126 | dsi->length = srclen; | |
1127 | /* Break the chain, so adjust_related_strinfo on later pointers in | |
1128 | the chain won't adjust this one anymore. */ | |
1129 | dsi->next = 0; | |
1130 | dsi->stmt = NULL; | |
1131 | dsi->endptr = NULL_TREE; | |
1132 | } | |
1133 | else | |
1134 | { | |
1135 | dsi = new_strinfo (dst, didx, srclen); | |
1136 | set_strinfo (didx, dsi); | |
1137 | find_equal_ptrs (dst, didx); | |
1138 | } | |
1139 | dsi->writable = true; | |
1140 | dsi->dont_invalidate = true; | |
1141 | ||
1142 | if (dsi->length == NULL_TREE) | |
1143 | { | |
93a90db6 AK |
1144 | strinfo chainsi; |
1145 | ||
8b57bfeb JJ |
1146 | /* If string length of src is unknown, use delayed length |
1147 | computation. If string lenth of dst will be needed, it | |
1148 | can be computed by transforming this strcpy call into | |
1149 | stpcpy and subtracting dst from the return value. */ | |
93a90db6 AK |
1150 | |
1151 | /* Look for earlier strings whose length could be determined if | |
1152 | this strcpy is turned into an stpcpy. */ | |
1153 | ||
1154 | if (dsi->prev != 0 && (chainsi = verify_related_strinfos (dsi)) != NULL) | |
1155 | { | |
1156 | for (; chainsi && chainsi != dsi; chainsi = get_strinfo (chainsi->next)) | |
1157 | { | |
1158 | /* When setting a stmt for delayed length computation | |
1159 | prevent all strinfos through dsi from being | |
1160 | invalidated. */ | |
1161 | chainsi = unshare_strinfo (chainsi); | |
1162 | chainsi->stmt = stmt; | |
1163 | chainsi->length = NULL_TREE; | |
1164 | chainsi->endptr = NULL_TREE; | |
1165 | chainsi->dont_invalidate = true; | |
1166 | } | |
1167 | } | |
8b57bfeb JJ |
1168 | dsi->stmt = stmt; |
1169 | return; | |
1170 | } | |
1171 | ||
1172 | if (olddsi != NULL) | |
1173 | { | |
1174 | tree adj = NULL_TREE; | |
1175 | if (oldlen == NULL_TREE) | |
1176 | ; | |
1177 | else if (integer_zerop (oldlen)) | |
1178 | adj = srclen; | |
1179 | else if (TREE_CODE (oldlen) == INTEGER_CST | |
1180 | || TREE_CODE (srclen) == INTEGER_CST) | |
1181 | adj = fold_build2_loc (loc, MINUS_EXPR, | |
1182 | TREE_TYPE (srclen), srclen, | |
1183 | fold_convert_loc (loc, TREE_TYPE (srclen), | |
1184 | oldlen)); | |
1185 | if (adj != NULL_TREE) | |
1186 | adjust_related_strinfos (loc, dsi, adj); | |
1187 | else | |
1188 | dsi->prev = 0; | |
1189 | } | |
1190 | /* strcpy src may not overlap dst, so src doesn't need to be | |
1191 | invalidated either. */ | |
1192 | if (si != NULL) | |
1193 | si->dont_invalidate = true; | |
1194 | ||
1195 | fn = NULL_TREE; | |
1196 | zsi = NULL; | |
1197 | switch (bcode) | |
1198 | { | |
1199 | case BUILT_IN_STRCPY: | |
e79983f4 | 1200 | fn = builtin_decl_implicit (BUILT_IN_MEMCPY); |
8b57bfeb | 1201 | if (lhs) |
9771b263 | 1202 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] = didx; |
8b57bfeb JJ |
1203 | break; |
1204 | case BUILT_IN_STRCPY_CHK: | |
e79983f4 | 1205 | fn = builtin_decl_explicit (BUILT_IN_MEMCPY_CHK); |
8b57bfeb | 1206 | if (lhs) |
9771b263 | 1207 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] = didx; |
8b57bfeb JJ |
1208 | break; |
1209 | case BUILT_IN_STPCPY: | |
1210 | /* This would need adjustment of the lhs (subtract one), | |
1211 | or detection that the trailing '\0' doesn't need to be | |
1212 | written, if it will be immediately overwritten. | |
e79983f4 | 1213 | fn = builtin_decl_explicit (BUILT_IN_MEMPCPY); */ |
8b57bfeb JJ |
1214 | if (lhs) |
1215 | { | |
1216 | dsi->endptr = lhs; | |
1217 | zsi = zero_length_string (lhs, dsi); | |
1218 | } | |
1219 | break; | |
1220 | case BUILT_IN_STPCPY_CHK: | |
1221 | /* This would need adjustment of the lhs (subtract one), | |
1222 | or detection that the trailing '\0' doesn't need to be | |
1223 | written, if it will be immediately overwritten. | |
e79983f4 | 1224 | fn = builtin_decl_explicit (BUILT_IN_MEMPCPY_CHK); */ |
8b57bfeb JJ |
1225 | if (lhs) |
1226 | { | |
1227 | dsi->endptr = lhs; | |
1228 | zsi = zero_length_string (lhs, dsi); | |
1229 | } | |
1230 | break; | |
1231 | default: | |
1232 | gcc_unreachable (); | |
1233 | } | |
1234 | if (zsi != NULL) | |
1235 | zsi->dont_invalidate = true; | |
1236 | ||
1237 | if (fn == NULL_TREE) | |
1238 | return; | |
1239 | ||
1240 | args = TYPE_ARG_TYPES (TREE_TYPE (fn)); | |
1241 | type = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (args))); | |
1242 | ||
1243 | len = fold_convert_loc (loc, type, unshare_expr (srclen)); | |
1244 | len = fold_build2_loc (loc, PLUS_EXPR, type, len, build_int_cst (type, 1)); | |
1245 | len = force_gimple_operand_gsi (gsi, len, true, NULL_TREE, true, | |
1246 | GSI_SAME_STMT); | |
1247 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1248 | { | |
1249 | fprintf (dump_file, "Optimizing: "); | |
1250 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1251 | } | |
1252 | if (gimple_call_num_args (stmt) == 2) | |
1253 | success = update_gimple_call (gsi, fn, 3, dst, src, len); | |
1254 | else | |
1255 | success = update_gimple_call (gsi, fn, 4, dst, src, len, | |
1256 | gimple_call_arg (stmt, 2)); | |
1257 | if (success) | |
1258 | { | |
1259 | stmt = gsi_stmt (*gsi); | |
1260 | update_stmt (stmt); | |
1261 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1262 | { | |
1263 | fprintf (dump_file, "into: "); | |
1264 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1265 | } | |
1266 | /* Allow adjust_last_stmt to decrease this memcpy's size. */ | |
1267 | laststmt.stmt = stmt; | |
1268 | laststmt.len = srclen; | |
1269 | laststmt.stridx = dsi->idx; | |
1270 | } | |
1271 | else if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1272 | fprintf (dump_file, "not possible.\n"); | |
1273 | } | |
1274 | ||
1275 | /* Handle a memcpy-like ({mem{,p}cpy,__mem{,p}cpy_chk}) call. | |
1276 | If strlen of the second argument is known and length of the third argument | |
1277 | is that plus one, strlen of the first argument is the same after this | |
1278 | call. */ | |
1279 | ||
1280 | static void | |
1281 | handle_builtin_memcpy (enum built_in_function bcode, gimple_stmt_iterator *gsi) | |
1282 | { | |
1283 | int idx, didx; | |
1284 | tree src, dst, len, lhs, oldlen, newlen; | |
1285 | gimple stmt = gsi_stmt (*gsi); | |
1286 | strinfo si, dsi, olddsi; | |
1287 | ||
1288 | len = gimple_call_arg (stmt, 2); | |
1289 | src = gimple_call_arg (stmt, 1); | |
1290 | dst = gimple_call_arg (stmt, 0); | |
1291 | idx = get_stridx (src); | |
1292 | if (idx == 0) | |
1293 | return; | |
1294 | ||
1295 | didx = get_stridx (dst); | |
1296 | olddsi = NULL; | |
1297 | if (didx > 0) | |
1298 | olddsi = get_strinfo (didx); | |
1299 | else if (didx < 0) | |
1300 | return; | |
1301 | ||
1302 | if (olddsi != NULL | |
1303 | && host_integerp (len, 1) | |
1304 | && !integer_zerop (len)) | |
1305 | adjust_last_stmt (olddsi, stmt, false); | |
1306 | ||
1307 | if (idx > 0) | |
1308 | { | |
1309 | gimple def_stmt; | |
1310 | ||
1311 | /* Handle memcpy (x, y, l) where l is strlen (y) + 1. */ | |
1312 | si = get_strinfo (idx); | |
1313 | if (si == NULL || si->length == NULL_TREE) | |
1314 | return; | |
1315 | if (TREE_CODE (len) != SSA_NAME) | |
1316 | return; | |
1317 | def_stmt = SSA_NAME_DEF_STMT (len); | |
1318 | if (!is_gimple_assign (def_stmt) | |
1319 | || gimple_assign_rhs_code (def_stmt) != PLUS_EXPR | |
1320 | || gimple_assign_rhs1 (def_stmt) != si->length | |
1321 | || !integer_onep (gimple_assign_rhs2 (def_stmt))) | |
1322 | return; | |
1323 | } | |
1324 | else | |
1325 | { | |
1326 | si = NULL; | |
1327 | /* Handle memcpy (x, "abcd", 5) or | |
1328 | memcpy (x, "abc\0uvw", 7). */ | |
1329 | if (!host_integerp (len, 1) | |
1330 | || (unsigned HOST_WIDE_INT) tree_low_cst (len, 1) | |
1331 | <= (unsigned HOST_WIDE_INT) ~idx) | |
1332 | return; | |
1333 | } | |
1334 | ||
1335 | if (olddsi != NULL && TREE_CODE (len) == SSA_NAME) | |
1336 | adjust_last_stmt (olddsi, stmt, false); | |
1337 | ||
1338 | if (didx == 0) | |
1339 | { | |
1340 | didx = new_stridx (dst); | |
1341 | if (didx == 0) | |
1342 | return; | |
1343 | } | |
1344 | if (si != NULL) | |
1345 | newlen = si->length; | |
1346 | else | |
80642376 | 1347 | newlen = build_int_cst (size_type_node, ~idx); |
8b57bfeb JJ |
1348 | oldlen = NULL_TREE; |
1349 | if (olddsi != NULL) | |
1350 | { | |
1351 | dsi = unshare_strinfo (olddsi); | |
1352 | oldlen = olddsi->length; | |
1353 | dsi->length = newlen; | |
1354 | /* Break the chain, so adjust_related_strinfo on later pointers in | |
1355 | the chain won't adjust this one anymore. */ | |
1356 | dsi->next = 0; | |
1357 | dsi->stmt = NULL; | |
1358 | dsi->endptr = NULL_TREE; | |
1359 | } | |
1360 | else | |
1361 | { | |
1362 | dsi = new_strinfo (dst, didx, newlen); | |
1363 | set_strinfo (didx, dsi); | |
1364 | find_equal_ptrs (dst, didx); | |
1365 | } | |
1366 | dsi->writable = true; | |
1367 | dsi->dont_invalidate = true; | |
1368 | if (olddsi != NULL) | |
1369 | { | |
1370 | tree adj = NULL_TREE; | |
1371 | location_t loc = gimple_location (stmt); | |
1372 | if (oldlen == NULL_TREE) | |
1373 | ; | |
1374 | else if (integer_zerop (oldlen)) | |
1375 | adj = dsi->length; | |
1376 | else if (TREE_CODE (oldlen) == INTEGER_CST | |
1377 | || TREE_CODE (dsi->length) == INTEGER_CST) | |
1378 | adj = fold_build2_loc (loc, MINUS_EXPR, | |
1379 | TREE_TYPE (dsi->length), dsi->length, | |
1380 | fold_convert_loc (loc, TREE_TYPE (dsi->length), | |
1381 | oldlen)); | |
1382 | if (adj != NULL_TREE) | |
1383 | adjust_related_strinfos (loc, dsi, adj); | |
1384 | else | |
1385 | dsi->prev = 0; | |
1386 | } | |
1387 | /* memcpy src may not overlap dst, so src doesn't need to be | |
1388 | invalidated either. */ | |
1389 | if (si != NULL) | |
1390 | si->dont_invalidate = true; | |
1391 | ||
1392 | lhs = gimple_call_lhs (stmt); | |
1393 | switch (bcode) | |
1394 | { | |
1395 | case BUILT_IN_MEMCPY: | |
1396 | case BUILT_IN_MEMCPY_CHK: | |
1397 | /* Allow adjust_last_stmt to decrease this memcpy's size. */ | |
1398 | laststmt.stmt = stmt; | |
1399 | laststmt.len = dsi->length; | |
1400 | laststmt.stridx = dsi->idx; | |
1401 | if (lhs) | |
9771b263 | 1402 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] = didx; |
8b57bfeb JJ |
1403 | break; |
1404 | case BUILT_IN_MEMPCPY: | |
1405 | case BUILT_IN_MEMPCPY_CHK: | |
1406 | break; | |
1407 | default: | |
1408 | gcc_unreachable (); | |
1409 | } | |
1410 | } | |
1411 | ||
1412 | /* Handle a strcat-like ({strcat,__strcat_chk}) call. | |
1413 | If strlen of the second argument is known, strlen of the first argument | |
1414 | is increased by the length of the second argument. Furthermore, attempt | |
1415 | to convert it to memcpy/strcpy if the length of the first argument | |
1416 | is known. */ | |
1417 | ||
1418 | static void | |
1419 | handle_builtin_strcat (enum built_in_function bcode, gimple_stmt_iterator *gsi) | |
1420 | { | |
1421 | int idx, didx; | |
1422 | tree src, dst, srclen, dstlen, len, lhs, args, type, fn, objsz, endptr; | |
1423 | bool success; | |
1424 | gimple stmt = gsi_stmt (*gsi); | |
1425 | strinfo si, dsi; | |
1426 | location_t loc; | |
1427 | ||
1428 | src = gimple_call_arg (stmt, 1); | |
1429 | dst = gimple_call_arg (stmt, 0); | |
1430 | lhs = gimple_call_lhs (stmt); | |
1431 | ||
1432 | didx = get_stridx (dst); | |
1433 | if (didx < 0) | |
1434 | return; | |
1435 | ||
1436 | dsi = NULL; | |
1437 | if (didx > 0) | |
1438 | dsi = get_strinfo (didx); | |
1439 | if (dsi == NULL || get_string_length (dsi) == NULL_TREE) | |
1440 | { | |
1441 | /* strcat (p, q) can be transformed into | |
1442 | tmp = p + strlen (p); endptr = strpcpy (tmp, q); | |
1443 | with length endptr - p if we need to compute the length | |
1444 | later on. Don't do this transformation if we don't need | |
1445 | it. */ | |
e79983f4 | 1446 | if (builtin_decl_implicit_p (BUILT_IN_STPCPY) && lhs == NULL_TREE) |
8b57bfeb JJ |
1447 | { |
1448 | if (didx == 0) | |
1449 | { | |
1450 | didx = new_stridx (dst); | |
1451 | if (didx == 0) | |
1452 | return; | |
1453 | } | |
1454 | if (dsi == NULL) | |
1455 | { | |
1456 | dsi = new_strinfo (dst, didx, NULL_TREE); | |
1457 | set_strinfo (didx, dsi); | |
1458 | find_equal_ptrs (dst, didx); | |
1459 | } | |
1460 | else | |
1461 | { | |
1462 | dsi = unshare_strinfo (dsi); | |
1463 | dsi->length = NULL_TREE; | |
1464 | dsi->next = 0; | |
1465 | dsi->endptr = NULL_TREE; | |
1466 | } | |
1467 | dsi->writable = true; | |
1468 | dsi->stmt = stmt; | |
1469 | dsi->dont_invalidate = true; | |
1470 | } | |
1471 | return; | |
1472 | } | |
1473 | ||
1474 | srclen = NULL_TREE; | |
1475 | si = NULL; | |
1476 | idx = get_stridx (src); | |
1477 | if (idx < 0) | |
1478 | srclen = build_int_cst (size_type_node, ~idx); | |
1479 | else if (idx > 0) | |
1480 | { | |
1481 | si = get_strinfo (idx); | |
1482 | if (si != NULL) | |
1483 | srclen = get_string_length (si); | |
1484 | } | |
1485 | ||
1486 | loc = gimple_location (stmt); | |
1487 | dstlen = dsi->length; | |
1488 | endptr = dsi->endptr; | |
1489 | ||
1490 | dsi = unshare_strinfo (dsi); | |
1491 | dsi->endptr = NULL_TREE; | |
1492 | dsi->stmt = NULL; | |
1493 | dsi->writable = true; | |
1494 | ||
1495 | if (srclen != NULL_TREE) | |
1496 | { | |
1497 | dsi->length = fold_build2_loc (loc, PLUS_EXPR, TREE_TYPE (dsi->length), | |
1498 | dsi->length, srclen); | |
1499 | adjust_related_strinfos (loc, dsi, srclen); | |
1500 | dsi->dont_invalidate = true; | |
1501 | } | |
1502 | else | |
1503 | { | |
1504 | dsi->length = NULL; | |
e79983f4 | 1505 | if (lhs == NULL_TREE && builtin_decl_implicit_p (BUILT_IN_STPCPY)) |
8b57bfeb JJ |
1506 | dsi->dont_invalidate = true; |
1507 | } | |
1508 | ||
1509 | if (si != NULL) | |
1510 | /* strcat src may not overlap dst, so src doesn't need to be | |
1511 | invalidated either. */ | |
1512 | si->dont_invalidate = true; | |
1513 | ||
1514 | /* For now. Could remove the lhs from the call and add | |
1515 | lhs = dst; afterwards. */ | |
1516 | if (lhs) | |
1517 | return; | |
1518 | ||
1519 | fn = NULL_TREE; | |
1520 | objsz = NULL_TREE; | |
1521 | switch (bcode) | |
1522 | { | |
1523 | case BUILT_IN_STRCAT: | |
1524 | if (srclen != NULL_TREE) | |
e79983f4 | 1525 | fn = builtin_decl_implicit (BUILT_IN_MEMCPY); |
8b57bfeb | 1526 | else |
e79983f4 | 1527 | fn = builtin_decl_implicit (BUILT_IN_STRCPY); |
8b57bfeb JJ |
1528 | break; |
1529 | case BUILT_IN_STRCAT_CHK: | |
1530 | if (srclen != NULL_TREE) | |
e79983f4 | 1531 | fn = builtin_decl_explicit (BUILT_IN_MEMCPY_CHK); |
8b57bfeb | 1532 | else |
e79983f4 | 1533 | fn = builtin_decl_explicit (BUILT_IN_STRCPY_CHK); |
8b57bfeb JJ |
1534 | objsz = gimple_call_arg (stmt, 2); |
1535 | break; | |
1536 | default: | |
1537 | gcc_unreachable (); | |
1538 | } | |
1539 | ||
1540 | if (fn == NULL_TREE) | |
1541 | return; | |
1542 | ||
1543 | len = NULL_TREE; | |
1544 | if (srclen != NULL_TREE) | |
1545 | { | |
1546 | args = TYPE_ARG_TYPES (TREE_TYPE (fn)); | |
1547 | type = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (args))); | |
1548 | ||
1549 | len = fold_convert_loc (loc, type, unshare_expr (srclen)); | |
1550 | len = fold_build2_loc (loc, PLUS_EXPR, type, len, | |
1551 | build_int_cst (type, 1)); | |
1552 | len = force_gimple_operand_gsi (gsi, len, true, NULL_TREE, true, | |
1553 | GSI_SAME_STMT); | |
1554 | } | |
1555 | if (endptr) | |
1556 | dst = fold_convert_loc (loc, TREE_TYPE (dst), unshare_expr (endptr)); | |
1557 | else | |
1558 | dst = fold_build2_loc (loc, POINTER_PLUS_EXPR, | |
1559 | TREE_TYPE (dst), unshare_expr (dst), | |
1560 | fold_convert_loc (loc, sizetype, | |
1561 | unshare_expr (dstlen))); | |
1562 | dst = force_gimple_operand_gsi (gsi, dst, true, NULL_TREE, true, | |
1563 | GSI_SAME_STMT); | |
1564 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1565 | { | |
1566 | fprintf (dump_file, "Optimizing: "); | |
1567 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1568 | } | |
1569 | if (srclen != NULL_TREE) | |
1570 | success = update_gimple_call (gsi, fn, 3 + (objsz != NULL_TREE), | |
1571 | dst, src, len, objsz); | |
1572 | else | |
1573 | success = update_gimple_call (gsi, fn, 2 + (objsz != NULL_TREE), | |
1574 | dst, src, objsz); | |
1575 | if (success) | |
1576 | { | |
1577 | stmt = gsi_stmt (*gsi); | |
1578 | update_stmt (stmt); | |
1579 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1580 | { | |
1581 | fprintf (dump_file, "into: "); | |
1582 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1583 | } | |
1584 | /* If srclen == NULL, note that current string length can be | |
1585 | computed by transforming this strcpy into stpcpy. */ | |
1586 | if (srclen == NULL_TREE && dsi->dont_invalidate) | |
1587 | dsi->stmt = stmt; | |
1588 | adjust_last_stmt (dsi, stmt, true); | |
1589 | if (srclen != NULL_TREE) | |
1590 | { | |
1591 | laststmt.stmt = stmt; | |
1592 | laststmt.len = srclen; | |
1593 | laststmt.stridx = dsi->idx; | |
1594 | } | |
1595 | } | |
1596 | else if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1597 | fprintf (dump_file, "not possible.\n"); | |
1598 | } | |
1599 | ||
1600 | /* Handle a POINTER_PLUS_EXPR statement. | |
1601 | For p = "abcd" + 2; compute associated length, or if | |
1602 | p = q + off is pointing to a '\0' character of a string, call | |
1603 | zero_length_string on it. */ | |
1604 | ||
1605 | static void | |
1606 | handle_pointer_plus (gimple_stmt_iterator *gsi) | |
1607 | { | |
1608 | gimple stmt = gsi_stmt (*gsi); | |
1609 | tree lhs = gimple_assign_lhs (stmt), off; | |
1610 | int idx = get_stridx (gimple_assign_rhs1 (stmt)); | |
1611 | strinfo si, zsi; | |
1612 | ||
1613 | if (idx == 0) | |
1614 | return; | |
1615 | ||
1616 | if (idx < 0) | |
1617 | { | |
1618 | tree off = gimple_assign_rhs2 (stmt); | |
1619 | if (host_integerp (off, 1) | |
1620 | && (unsigned HOST_WIDE_INT) tree_low_cst (off, 1) | |
1621 | <= (unsigned HOST_WIDE_INT) ~idx) | |
9771b263 DN |
1622 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] |
1623 | = ~(~idx - (int) tree_low_cst (off, 1)); | |
8b57bfeb JJ |
1624 | return; |
1625 | } | |
1626 | ||
1627 | si = get_strinfo (idx); | |
1628 | if (si == NULL || si->length == NULL_TREE) | |
1629 | return; | |
1630 | ||
1631 | off = gimple_assign_rhs2 (stmt); | |
1632 | zsi = NULL; | |
1633 | if (operand_equal_p (si->length, off, 0)) | |
1634 | zsi = zero_length_string (lhs, si); | |
1635 | else if (TREE_CODE (off) == SSA_NAME) | |
1636 | { | |
1637 | gimple def_stmt = SSA_NAME_DEF_STMT (off); | |
1638 | if (gimple_assign_single_p (def_stmt) | |
1639 | && operand_equal_p (si->length, gimple_assign_rhs1 (def_stmt), 0)) | |
1640 | zsi = zero_length_string (lhs, si); | |
1641 | } | |
1642 | if (zsi != NULL | |
1643 | && si->endptr != NULL_TREE | |
1644 | && si->endptr != lhs | |
1645 | && TREE_CODE (si->endptr) == SSA_NAME) | |
1646 | { | |
1647 | enum tree_code rhs_code | |
1648 | = useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (si->endptr)) | |
1649 | ? SSA_NAME : NOP_EXPR; | |
1650 | gimple_assign_set_rhs_with_ops (gsi, rhs_code, si->endptr, NULL_TREE); | |
1651 | gcc_assert (gsi_stmt (*gsi) == stmt); | |
1652 | update_stmt (stmt); | |
1653 | } | |
1654 | } | |
1655 | ||
1656 | /* Handle a single character store. */ | |
1657 | ||
1658 | static bool | |
1659 | handle_char_store (gimple_stmt_iterator *gsi) | |
1660 | { | |
1661 | int idx = -1; | |
1662 | strinfo si = NULL; | |
1663 | gimple stmt = gsi_stmt (*gsi); | |
1664 | tree ssaname = NULL_TREE, lhs = gimple_assign_lhs (stmt); | |
1665 | ||
1666 | if (TREE_CODE (lhs) == MEM_REF | |
1667 | && TREE_CODE (TREE_OPERAND (lhs, 0)) == SSA_NAME) | |
1668 | { | |
1669 | if (integer_zerop (TREE_OPERAND (lhs, 1))) | |
1670 | { | |
1671 | ssaname = TREE_OPERAND (lhs, 0); | |
1672 | idx = get_stridx (ssaname); | |
1673 | } | |
1674 | } | |
1675 | else | |
1676 | idx = get_addr_stridx (lhs); | |
1677 | ||
1678 | if (idx > 0) | |
1679 | { | |
1680 | si = get_strinfo (idx); | |
1681 | if (si != NULL && si->length != NULL_TREE && integer_zerop (si->length)) | |
1682 | { | |
1683 | if (initializer_zerop (gimple_assign_rhs1 (stmt))) | |
1684 | { | |
1685 | /* When storing '\0', the store can be removed | |
1686 | if we know it has been stored in the current function. */ | |
1687 | if (!stmt_could_throw_p (stmt) && si->writable) | |
1688 | { | |
1689 | unlink_stmt_vdef (stmt); | |
1690 | release_defs (stmt); | |
1691 | gsi_remove (gsi, true); | |
1692 | return false; | |
1693 | } | |
1694 | else | |
1695 | { | |
1696 | si->writable = true; | |
1697 | si->dont_invalidate = true; | |
1698 | } | |
1699 | } | |
1700 | else | |
1701 | /* Otherwise this statement overwrites the '\0' with | |
1702 | something, if the previous stmt was a memcpy, | |
1703 | its length may be decreased. */ | |
1704 | adjust_last_stmt (si, stmt, false); | |
1705 | } | |
3a60f32b | 1706 | else if (si != NULL && integer_zerop (gimple_assign_rhs1 (stmt))) |
8b57bfeb JJ |
1707 | { |
1708 | si = unshare_strinfo (si); | |
1709 | si->length = build_int_cst (size_type_node, 0); | |
1710 | si->endptr = NULL; | |
1711 | si->prev = 0; | |
1712 | si->next = 0; | |
1713 | si->stmt = NULL; | |
1714 | si->first = 0; | |
1715 | si->writable = true; | |
1716 | if (ssaname && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ssaname)) | |
1717 | si->endptr = ssaname; | |
1718 | si->dont_invalidate = true; | |
1719 | } | |
1720 | } | |
1721 | else if (idx == 0 && initializer_zerop (gimple_assign_rhs1 (stmt))) | |
1722 | { | |
1723 | if (ssaname) | |
1724 | { | |
1725 | si = zero_length_string (ssaname, NULL); | |
1726 | if (si != NULL) | |
1727 | si->dont_invalidate = true; | |
1728 | } | |
1729 | else | |
1730 | { | |
1731 | int idx = new_addr_stridx (lhs); | |
1732 | if (idx != 0) | |
1733 | { | |
1734 | si = new_strinfo (build_fold_addr_expr (lhs), idx, | |
1735 | build_int_cst (size_type_node, 0)); | |
1736 | set_strinfo (idx, si); | |
1737 | si->dont_invalidate = true; | |
1738 | } | |
1739 | } | |
1740 | if (si != NULL) | |
1741 | si->writable = true; | |
1742 | } | |
1743 | ||
1744 | if (si != NULL && initializer_zerop (gimple_assign_rhs1 (stmt))) | |
1745 | { | |
1746 | /* Allow adjust_last_stmt to remove it if the stored '\0' | |
1747 | is immediately overwritten. */ | |
1748 | laststmt.stmt = stmt; | |
1749 | laststmt.len = build_int_cst (size_type_node, 1); | |
1750 | laststmt.stridx = si->idx; | |
1751 | } | |
1752 | return true; | |
1753 | } | |
1754 | ||
1755 | /* Attempt to optimize a single statement at *GSI using string length | |
1756 | knowledge. */ | |
1757 | ||
1758 | static bool | |
1759 | strlen_optimize_stmt (gimple_stmt_iterator *gsi) | |
1760 | { | |
1761 | gimple stmt = gsi_stmt (*gsi); | |
1762 | ||
1763 | if (is_gimple_call (stmt)) | |
1764 | { | |
1765 | tree callee = gimple_call_fndecl (stmt); | |
3626621a | 1766 | if (gimple_call_builtin_p (stmt, BUILT_IN_NORMAL)) |
8b57bfeb JJ |
1767 | switch (DECL_FUNCTION_CODE (callee)) |
1768 | { | |
1769 | case BUILT_IN_STRLEN: | |
1770 | handle_builtin_strlen (gsi); | |
1771 | break; | |
1772 | case BUILT_IN_STRCHR: | |
1773 | handle_builtin_strchr (gsi); | |
1774 | break; | |
1775 | case BUILT_IN_STRCPY: | |
1776 | case BUILT_IN_STRCPY_CHK: | |
1777 | case BUILT_IN_STPCPY: | |
1778 | case BUILT_IN_STPCPY_CHK: | |
1779 | handle_builtin_strcpy (DECL_FUNCTION_CODE (callee), gsi); | |
1780 | break; | |
1781 | case BUILT_IN_MEMCPY: | |
1782 | case BUILT_IN_MEMCPY_CHK: | |
1783 | case BUILT_IN_MEMPCPY: | |
1784 | case BUILT_IN_MEMPCPY_CHK: | |
1785 | handle_builtin_memcpy (DECL_FUNCTION_CODE (callee), gsi); | |
1786 | break; | |
1787 | case BUILT_IN_STRCAT: | |
1788 | case BUILT_IN_STRCAT_CHK: | |
1789 | handle_builtin_strcat (DECL_FUNCTION_CODE (callee), gsi); | |
1790 | break; | |
1791 | default: | |
1792 | break; | |
1793 | } | |
1794 | } | |
1795 | else if (is_gimple_assign (stmt)) | |
1796 | { | |
1797 | tree lhs = gimple_assign_lhs (stmt); | |
1798 | ||
1799 | if (TREE_CODE (lhs) == SSA_NAME && POINTER_TYPE_P (TREE_TYPE (lhs))) | |
1800 | { | |
1801 | if (gimple_assign_single_p (stmt) | |
1802 | || (gimple_assign_cast_p (stmt) | |
1803 | && POINTER_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (stmt))))) | |
1804 | { | |
1805 | int idx = get_stridx (gimple_assign_rhs1 (stmt)); | |
9771b263 | 1806 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] = idx; |
8b57bfeb JJ |
1807 | } |
1808 | else if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR) | |
1809 | handle_pointer_plus (gsi); | |
1810 | } | |
1811 | else if (TREE_CODE (lhs) != SSA_NAME && !TREE_SIDE_EFFECTS (lhs)) | |
1812 | { | |
1813 | tree type = TREE_TYPE (lhs); | |
1814 | if (TREE_CODE (type) == ARRAY_TYPE) | |
1815 | type = TREE_TYPE (type); | |
1816 | if (TREE_CODE (type) == INTEGER_TYPE | |
1817 | && TYPE_MODE (type) == TYPE_MODE (char_type_node) | |
1818 | && TYPE_PRECISION (type) == TYPE_PRECISION (char_type_node)) | |
1819 | { | |
1820 | if (! handle_char_store (gsi)) | |
1821 | return false; | |
1822 | } | |
1823 | } | |
1824 | } | |
1825 | ||
1826 | if (gimple_vdef (stmt)) | |
1827 | maybe_invalidate (stmt); | |
1828 | return true; | |
1829 | } | |
1830 | ||
1831 | /* Recursively call maybe_invalidate on stmts that might be executed | |
1832 | in between dombb and current bb and that contain a vdef. Stop when | |
1833 | *count stmts are inspected, or if the whole strinfo vector has | |
1834 | been invalidated. */ | |
1835 | ||
1836 | static void | |
1837 | do_invalidate (basic_block dombb, gimple phi, bitmap visited, int *count) | |
1838 | { | |
1839 | unsigned int i, n = gimple_phi_num_args (phi); | |
1840 | ||
1841 | for (i = 0; i < n; i++) | |
1842 | { | |
1843 | tree vuse = gimple_phi_arg_def (phi, i); | |
1844 | gimple stmt = SSA_NAME_DEF_STMT (vuse); | |
1845 | basic_block bb = gimple_bb (stmt); | |
1846 | if (bb == NULL | |
1847 | || bb == dombb | |
1848 | || !bitmap_set_bit (visited, bb->index) | |
1849 | || !dominated_by_p (CDI_DOMINATORS, bb, dombb)) | |
1850 | continue; | |
1851 | while (1) | |
1852 | { | |
1853 | if (gimple_code (stmt) == GIMPLE_PHI) | |
1854 | { | |
1855 | do_invalidate (dombb, stmt, visited, count); | |
1856 | if (*count == 0) | |
1857 | return; | |
1858 | break; | |
1859 | } | |
1860 | if (--*count == 0) | |
1861 | return; | |
1862 | if (!maybe_invalidate (stmt)) | |
1863 | { | |
1864 | *count = 0; | |
1865 | return; | |
1866 | } | |
1867 | vuse = gimple_vuse (stmt); | |
1868 | stmt = SSA_NAME_DEF_STMT (vuse); | |
1869 | if (gimple_bb (stmt) != bb) | |
1870 | { | |
1871 | bb = gimple_bb (stmt); | |
1872 | if (bb == NULL | |
1873 | || bb == dombb | |
1874 | || !bitmap_set_bit (visited, bb->index) | |
1875 | || !dominated_by_p (CDI_DOMINATORS, bb, dombb)) | |
1876 | break; | |
1877 | } | |
1878 | } | |
1879 | } | |
1880 | } | |
1881 | ||
1882 | /* Callback for walk_dominator_tree. Attempt to optimize various | |
1883 | string ops by remembering string lenths pointed by pointer SSA_NAMEs. */ | |
1884 | ||
1885 | static void | |
1886 | strlen_enter_block (struct dom_walk_data *walk_data ATTRIBUTE_UNUSED, | |
1887 | basic_block bb) | |
1888 | { | |
1889 | gimple_stmt_iterator gsi; | |
1890 | basic_block dombb = get_immediate_dominator (CDI_DOMINATORS, bb); | |
1891 | ||
1892 | if (dombb == NULL) | |
1893 | stridx_to_strinfo = NULL; | |
1894 | else | |
1895 | { | |
9771b263 | 1896 | stridx_to_strinfo = ((vec<strinfo, va_heap, vl_embed> *) dombb->aux); |
8b57bfeb JJ |
1897 | if (stridx_to_strinfo) |
1898 | { | |
1899 | for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
1900 | { | |
1901 | gimple phi = gsi_stmt (gsi); | |
ea057359 | 1902 | if (virtual_operand_p (gimple_phi_result (phi))) |
8b57bfeb JJ |
1903 | { |
1904 | bitmap visited = BITMAP_ALLOC (NULL); | |
1905 | int count_vdef = 100; | |
1906 | do_invalidate (dombb, phi, visited, &count_vdef); | |
1907 | BITMAP_FREE (visited); | |
1908 | break; | |
1909 | } | |
1910 | } | |
1911 | } | |
1912 | } | |
1913 | ||
1914 | /* If all PHI arguments have the same string index, the PHI result | |
1915 | has it as well. */ | |
1916 | for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
1917 | { | |
1918 | gimple phi = gsi_stmt (gsi); | |
1919 | tree result = gimple_phi_result (phi); | |
ea057359 | 1920 | if (!virtual_operand_p (result) && POINTER_TYPE_P (TREE_TYPE (result))) |
8b57bfeb JJ |
1921 | { |
1922 | int idx = get_stridx (gimple_phi_arg_def (phi, 0)); | |
1923 | if (idx != 0) | |
1924 | { | |
1925 | unsigned int i, n = gimple_phi_num_args (phi); | |
1926 | for (i = 1; i < n; i++) | |
1927 | if (idx != get_stridx (gimple_phi_arg_def (phi, i))) | |
1928 | break; | |
1929 | if (i == n) | |
9771b263 | 1930 | ssa_ver_to_stridx[SSA_NAME_VERSION (result)] = idx; |
8b57bfeb JJ |
1931 | } |
1932 | } | |
1933 | } | |
1934 | ||
1935 | /* Attempt to optimize individual statements. */ | |
1936 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); ) | |
1937 | if (strlen_optimize_stmt (&gsi)) | |
1938 | gsi_next (&gsi); | |
1939 | ||
1940 | bb->aux = stridx_to_strinfo; | |
9771b263 DN |
1941 | if (vec_safe_length (stridx_to_strinfo) && !strinfo_shared ()) |
1942 | (*stridx_to_strinfo)[0] = (strinfo) bb; | |
8b57bfeb JJ |
1943 | } |
1944 | ||
1945 | /* Callback for walk_dominator_tree. Free strinfo vector if it is | |
1946 | owned by the current bb, clear bb->aux. */ | |
1947 | ||
1948 | static void | |
1949 | strlen_leave_block (struct dom_walk_data *walk_data ATTRIBUTE_UNUSED, | |
1950 | basic_block bb) | |
1951 | { | |
1952 | if (bb->aux) | |
1953 | { | |
9771b263 DN |
1954 | stridx_to_strinfo = ((vec<strinfo, va_heap, vl_embed> *) bb->aux); |
1955 | if (vec_safe_length (stridx_to_strinfo) | |
1956 | && (*stridx_to_strinfo)[0] == (strinfo) bb) | |
8b57bfeb JJ |
1957 | { |
1958 | unsigned int i; | |
1959 | strinfo si; | |
1960 | ||
9771b263 | 1961 | for (i = 1; vec_safe_iterate (stridx_to_strinfo, i, &si); ++i) |
8b57bfeb | 1962 | free_strinfo (si); |
9771b263 | 1963 | vec_free (stridx_to_strinfo); |
8b57bfeb JJ |
1964 | } |
1965 | bb->aux = NULL; | |
1966 | } | |
1967 | } | |
1968 | ||
1969 | /* Main entry point. */ | |
1970 | ||
1971 | static unsigned int | |
1972 | tree_ssa_strlen (void) | |
1973 | { | |
1974 | struct dom_walk_data walk_data; | |
1975 | ||
9771b263 | 1976 | ssa_ver_to_stridx.safe_grow_cleared (num_ssa_names); |
8b57bfeb JJ |
1977 | max_stridx = 1; |
1978 | strinfo_pool = create_alloc_pool ("strinfo_struct pool", | |
1979 | sizeof (struct strinfo_struct), 64); | |
1980 | ||
1981 | calculate_dominance_info (CDI_DOMINATORS); | |
1982 | ||
1983 | /* String length optimization is implemented as a walk of the dominator | |
1984 | tree and a forward walk of statements within each block. */ | |
1985 | walk_data.dom_direction = CDI_DOMINATORS; | |
1986 | walk_data.initialize_block_local_data = NULL; | |
1987 | walk_data.before_dom_children = strlen_enter_block; | |
1988 | walk_data.after_dom_children = strlen_leave_block; | |
1989 | walk_data.block_local_data_size = 0; | |
1990 | walk_data.global_data = NULL; | |
1991 | ||
1992 | /* Initialize the dominator walker. */ | |
1993 | init_walk_dominator_tree (&walk_data); | |
1994 | ||
1995 | /* Recursively walk the dominator tree. */ | |
1996 | walk_dominator_tree (&walk_data, ENTRY_BLOCK_PTR); | |
1997 | ||
1998 | /* Finalize the dominator walker. */ | |
1999 | fini_walk_dominator_tree (&walk_data); | |
2000 | ||
9771b263 | 2001 | ssa_ver_to_stridx.release (); |
8b57bfeb | 2002 | free_alloc_pool (strinfo_pool); |
4a8fb1a1 | 2003 | if (decl_to_stridxlist_htab.is_created ()) |
8b57bfeb JJ |
2004 | { |
2005 | obstack_free (&stridx_obstack, NULL); | |
4a8fb1a1 | 2006 | decl_to_stridxlist_htab.dispose (); |
8b57bfeb JJ |
2007 | } |
2008 | laststmt.stmt = NULL; | |
2009 | laststmt.len = NULL_TREE; | |
2010 | laststmt.stridx = 0; | |
2011 | ||
2012 | return 0; | |
2013 | } | |
2014 | ||
2015 | static bool | |
2016 | gate_strlen (void) | |
2017 | { | |
2018 | return flag_optimize_strlen != 0; | |
2019 | } | |
2020 | ||
2021 | struct gimple_opt_pass pass_strlen = | |
2022 | { | |
2023 | { | |
2024 | GIMPLE_PASS, | |
2025 | "strlen", /* name */ | |
2b4e6bf1 | 2026 | OPTGROUP_NONE, /* optinfo_flags */ |
8b57bfeb JJ |
2027 | gate_strlen, /* gate */ |
2028 | tree_ssa_strlen, /* execute */ | |
2029 | NULL, /* sub */ | |
2030 | NULL, /* next */ | |
2031 | 0, /* static_pass_number */ | |
2032 | TV_TREE_STRLEN, /* tv_id */ | |
2033 | PROP_cfg | PROP_ssa, /* properties_required */ | |
2034 | 0, /* properties_provided */ | |
2035 | 0, /* properties_destroyed */ | |
2036 | 0, /* todo_flags_start */ | |
bb313b93 | 2037 | TODO_verify_ssa /* todo_flags_finish */ |
8b57bfeb JJ |
2038 | } |
2039 | }; |