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4ee9c684 | 1 | /* Alias analysis for trees. |
711789cc | 2 | Copyright (C) 2004-2013 Free Software Foundation, Inc. |
4ee9c684 | 3 | Contributed by Diego Novillo <dnovillo@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 | |
8c4c00c1 | 9 | the Free Software Foundation; either version 3, or (at your option) |
4ee9c684 | 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 | |
8c4c00c1 | 18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
4ee9c684 | 20 | |
21 | #include "config.h" | |
22 | #include "system.h" | |
23 | #include "coretypes.h" | |
24 | #include "tm.h" | |
25 | #include "tree.h" | |
4ee9c684 | 26 | #include "tm_p.h" |
be97d4b6 | 27 | #include "target.h" |
4ee9c684 | 28 | #include "basic-block.h" |
b9ed1410 | 29 | #include "timevar.h" /* for TV_ALIAS_STMT_WALK */ |
4ee9c684 | 30 | #include "ggc.h" |
31 | #include "langhooks.h" | |
32 | #include "flags.h" | |
33 | #include "function.h" | |
ce084dfc | 34 | #include "tree-pretty-print.h" |
b9ed1410 | 35 | #include "dumpfile.h" |
75a70cf9 | 36 | #include "gimple.h" |
4ee9c684 | 37 | #include "tree-flow.h" |
38 | #include "tree-inline.h" | |
4ee9c684 | 39 | #include "params.h" |
2be14d8b | 40 | #include "vec.h" |
a55dc2cd | 41 | #include "bitmap.h" |
4fb5e5ca | 42 | #include "pointer-set.h" |
6cc9bd27 | 43 | #include "alloc-pool.h" |
dd277d48 | 44 | #include "tree-ssa-alias.h" |
a55dc2cd | 45 | |
dd277d48 | 46 | /* Broad overview of how alias analysis on gimple works: |
4fb5e5ca | 47 | |
dd277d48 | 48 | Statements clobbering or using memory are linked through the |
49 | virtual operand factored use-def chain. The virtual operand | |
50 | is unique per function, its symbol is accessible via gimple_vop (cfun). | |
51 | Virtual operands are used for efficiently walking memory statements | |
52 | in the gimple IL and are useful for things like value-numbering as | |
53 | a generation count for memory references. | |
339d7079 | 54 | |
dd277d48 | 55 | SSA_NAME pointers may have associated points-to information |
56 | accessible via the SSA_NAME_PTR_INFO macro. Flow-insensitive | |
57 | points-to information is (re-)computed by the TODO_rebuild_alias | |
58 | pass manager todo. Points-to information is also used for more | |
59 | precise tracking of call-clobbered and call-used variables and | |
60 | related disambiguations. | |
339d7079 | 61 | |
dd277d48 | 62 | This file contains functions for disambiguating memory references, |
63 | the so called alias-oracle and tools for walking of the gimple IL. | |
339d7079 | 64 | |
dd277d48 | 65 | The main alias-oracle entry-points are |
339d7079 | 66 | |
dd277d48 | 67 | bool stmt_may_clobber_ref_p (gimple, tree) |
339d7079 | 68 | |
dd277d48 | 69 | This function queries if a statement may invalidate (parts of) |
70 | the memory designated by the reference tree argument. | |
339d7079 | 71 | |
dd277d48 | 72 | bool ref_maybe_used_by_stmt_p (gimple, tree) |
339d7079 | 73 | |
dd277d48 | 74 | This function queries if a statement may need (parts of) the |
75 | memory designated by the reference tree argument. | |
339d7079 | 76 | |
dd277d48 | 77 | There are variants of these functions that only handle the call |
78 | part of a statement, call_may_clobber_ref_p and ref_maybe_used_by_call_p. | |
79 | Note that these do not disambiguate against a possible call lhs. | |
339d7079 | 80 | |
dd277d48 | 81 | bool refs_may_alias_p (tree, tree) |
339d7079 | 82 | |
dd277d48 | 83 | This function tries to disambiguate two reference trees. |
05931b00 | 84 | |
dd277d48 | 85 | bool ptr_deref_may_alias_global_p (tree) |
339d7079 | 86 | |
dd277d48 | 87 | This function queries if dereferencing a pointer variable may |
88 | alias global memory. | |
339d7079 | 89 | |
dd277d48 | 90 | More low-level disambiguators are available and documented in |
91 | this file. Low-level disambiguators dealing with points-to | |
92 | information are in tree-ssa-structalias.c. */ | |
339d7079 | 93 | |
339d7079 | 94 | |
dd277d48 | 95 | /* Query statistics for the different low-level disambiguators. |
96 | A high-level query may trigger multiple of them. */ | |
339d7079 | 97 | |
dd277d48 | 98 | static struct { |
99 | unsigned HOST_WIDE_INT refs_may_alias_p_may_alias; | |
100 | unsigned HOST_WIDE_INT refs_may_alias_p_no_alias; | |
101 | unsigned HOST_WIDE_INT ref_maybe_used_by_call_p_may_alias; | |
102 | unsigned HOST_WIDE_INT ref_maybe_used_by_call_p_no_alias; | |
103 | unsigned HOST_WIDE_INT call_may_clobber_ref_p_may_alias; | |
104 | unsigned HOST_WIDE_INT call_may_clobber_ref_p_no_alias; | |
105 | } alias_stats; | |
339d7079 | 106 | |
dd277d48 | 107 | void |
108 | dump_alias_stats (FILE *s) | |
109 | { | |
110 | fprintf (s, "\nAlias oracle query stats:\n"); | |
111 | fprintf (s, " refs_may_alias_p: " | |
112 | HOST_WIDE_INT_PRINT_DEC" disambiguations, " | |
113 | HOST_WIDE_INT_PRINT_DEC" queries\n", | |
114 | alias_stats.refs_may_alias_p_no_alias, | |
115 | alias_stats.refs_may_alias_p_no_alias | |
116 | + alias_stats.refs_may_alias_p_may_alias); | |
117 | fprintf (s, " ref_maybe_used_by_call_p: " | |
118 | HOST_WIDE_INT_PRINT_DEC" disambiguations, " | |
119 | HOST_WIDE_INT_PRINT_DEC" queries\n", | |
120 | alias_stats.ref_maybe_used_by_call_p_no_alias, | |
121 | alias_stats.refs_may_alias_p_no_alias | |
122 | + alias_stats.ref_maybe_used_by_call_p_may_alias); | |
123 | fprintf (s, " call_may_clobber_ref_p: " | |
124 | HOST_WIDE_INT_PRINT_DEC" disambiguations, " | |
125 | HOST_WIDE_INT_PRINT_DEC" queries\n", | |
126 | alias_stats.call_may_clobber_ref_p_no_alias, | |
127 | alias_stats.call_may_clobber_ref_p_no_alias | |
128 | + alias_stats.call_may_clobber_ref_p_may_alias); | |
129 | } | |
130 | ||
131 | ||
132 | /* Return true, if dereferencing PTR may alias with a global variable. */ | |
4ee9c684 | 133 | |
dd277d48 | 134 | bool |
135 | ptr_deref_may_alias_global_p (tree ptr) | |
4ee9c684 | 136 | { |
dd277d48 | 137 | struct ptr_info_def *pi; |
4fb5e5ca | 138 | |
dd277d48 | 139 | /* If we end up with a pointer constant here that may point |
140 | to global memory. */ | |
141 | if (TREE_CODE (ptr) != SSA_NAME) | |
142 | return true; | |
4ee9c684 | 143 | |
dd277d48 | 144 | pi = SSA_NAME_PTR_INFO (ptr); |
4ee9c684 | 145 | |
dd277d48 | 146 | /* If we do not have points-to information for this variable, |
147 | we have to punt. */ | |
148 | if (!pi) | |
149 | return true; | |
4ee9c684 | 150 | |
2a3ebafa | 151 | /* ??? This does not use TBAA to prune globals ptr may not access. */ |
dd277d48 | 152 | return pt_solution_includes_global (&pi->pt); |
4ee9c684 | 153 | } |
154 | ||
2a3ebafa | 155 | /* Return true if dereferencing PTR may alias DECL. |
156 | The caller is responsible for applying TBAA to see if PTR | |
157 | may access DECL at all. */ | |
4ee9c684 | 158 | |
dd277d48 | 159 | static bool |
160 | ptr_deref_may_alias_decl_p (tree ptr, tree decl) | |
4ee9c684 | 161 | { |
dd277d48 | 162 | struct ptr_info_def *pi; |
f7d118a9 | 163 | |
2760c0e3 | 164 | /* Conversions are irrelevant for points-to information and |
165 | data-dependence analysis can feed us those. */ | |
166 | STRIP_NOPS (ptr); | |
167 | ||
168 | /* Anything we do not explicilty handle aliases. */ | |
169 | if ((TREE_CODE (ptr) != SSA_NAME | |
170 | && TREE_CODE (ptr) != ADDR_EXPR | |
171 | && TREE_CODE (ptr) != POINTER_PLUS_EXPR) | |
172 | || !POINTER_TYPE_P (TREE_TYPE (ptr)) | |
173 | || (TREE_CODE (decl) != VAR_DECL | |
174 | && TREE_CODE (decl) != PARM_DECL | |
175 | && TREE_CODE (decl) != RESULT_DECL)) | |
9c01641d | 176 | return true; |
2fd0b5dc | 177 | |
2760c0e3 | 178 | /* Disregard pointer offsetting. */ |
179 | if (TREE_CODE (ptr) == POINTER_PLUS_EXPR) | |
180 | { | |
181 | do | |
182 | { | |
183 | ptr = TREE_OPERAND (ptr, 0); | |
184 | } | |
185 | while (TREE_CODE (ptr) == POINTER_PLUS_EXPR); | |
186 | return ptr_deref_may_alias_decl_p (ptr, decl); | |
187 | } | |
188 | ||
047fdd47 | 189 | /* ADDR_EXPR pointers either just offset another pointer or directly |
190 | specify the pointed-to set. */ | |
191 | if (TREE_CODE (ptr) == ADDR_EXPR) | |
192 | { | |
193 | tree base = get_base_address (TREE_OPERAND (ptr, 0)); | |
194 | if (base | |
2622064f | 195 | && (TREE_CODE (base) == MEM_REF |
196 | || TREE_CODE (base) == TARGET_MEM_REF)) | |
047fdd47 | 197 | ptr = TREE_OPERAND (base, 0); |
198 | else if (base | |
2622064f | 199 | && DECL_P (base)) |
7f2d9047 | 200 | return base == decl; |
047fdd47 | 201 | else if (base |
202 | && CONSTANT_CLASS_P (base)) | |
203 | return false; | |
204 | else | |
205 | return true; | |
206 | } | |
207 | ||
2760c0e3 | 208 | /* Non-aliased variables can not be pointed to. */ |
209 | if (!may_be_aliased (decl)) | |
210 | return false; | |
047fdd47 | 211 | |
dd277d48 | 212 | /* If we do not have useful points-to information for this pointer |
213 | we cannot disambiguate anything else. */ | |
214 | pi = SSA_NAME_PTR_INFO (ptr); | |
215 | if (!pi) | |
2fd0b5dc | 216 | return true; |
217 | ||
dd277d48 | 218 | return pt_solution_includes (&pi->pt, decl); |
2fd0b5dc | 219 | } |
4ee9c684 | 220 | |
2a3ebafa | 221 | /* Return true if dereferenced PTR1 and PTR2 may alias. |
222 | The caller is responsible for applying TBAA to see if accesses | |
223 | through PTR1 and PTR2 may conflict at all. */ | |
4ee9c684 | 224 | |
2760c0e3 | 225 | bool |
dd277d48 | 226 | ptr_derefs_may_alias_p (tree ptr1, tree ptr2) |
4ee9c684 | 227 | { |
dd277d48 | 228 | struct ptr_info_def *pi1, *pi2; |
4ee9c684 | 229 | |
2760c0e3 | 230 | /* Conversions are irrelevant for points-to information and |
231 | data-dependence analysis can feed us those. */ | |
232 | STRIP_NOPS (ptr1); | |
233 | STRIP_NOPS (ptr2); | |
234 | ||
2760c0e3 | 235 | /* Disregard pointer offsetting. */ |
236 | if (TREE_CODE (ptr1) == POINTER_PLUS_EXPR) | |
237 | { | |
238 | do | |
239 | { | |
240 | ptr1 = TREE_OPERAND (ptr1, 0); | |
241 | } | |
242 | while (TREE_CODE (ptr1) == POINTER_PLUS_EXPR); | |
243 | return ptr_derefs_may_alias_p (ptr1, ptr2); | |
244 | } | |
245 | if (TREE_CODE (ptr2) == POINTER_PLUS_EXPR) | |
246 | { | |
247 | do | |
248 | { | |
249 | ptr2 = TREE_OPERAND (ptr2, 0); | |
250 | } | |
251 | while (TREE_CODE (ptr2) == POINTER_PLUS_EXPR); | |
252 | return ptr_derefs_may_alias_p (ptr1, ptr2); | |
253 | } | |
f85fb819 | 254 | |
047fdd47 | 255 | /* ADDR_EXPR pointers either just offset another pointer or directly |
256 | specify the pointed-to set. */ | |
257 | if (TREE_CODE (ptr1) == ADDR_EXPR) | |
258 | { | |
259 | tree base = get_base_address (TREE_OPERAND (ptr1, 0)); | |
260 | if (base | |
2622064f | 261 | && (TREE_CODE (base) == MEM_REF |
262 | || TREE_CODE (base) == TARGET_MEM_REF)) | |
80b4d93e | 263 | return ptr_derefs_may_alias_p (TREE_OPERAND (base, 0), ptr2); |
047fdd47 | 264 | else if (base |
2622064f | 265 | && DECL_P (base)) |
047fdd47 | 266 | return ptr_deref_may_alias_decl_p (ptr2, base); |
267 | else | |
268 | return true; | |
269 | } | |
270 | if (TREE_CODE (ptr2) == ADDR_EXPR) | |
271 | { | |
272 | tree base = get_base_address (TREE_OPERAND (ptr2, 0)); | |
273 | if (base | |
2622064f | 274 | && (TREE_CODE (base) == MEM_REF |
275 | || TREE_CODE (base) == TARGET_MEM_REF)) | |
80b4d93e | 276 | return ptr_derefs_may_alias_p (ptr1, TREE_OPERAND (base, 0)); |
047fdd47 | 277 | else if (base |
2622064f | 278 | && DECL_P (base)) |
047fdd47 | 279 | return ptr_deref_may_alias_decl_p (ptr1, base); |
280 | else | |
281 | return true; | |
282 | } | |
283 | ||
80b4d93e | 284 | /* From here we require SSA name pointers. Anything else aliases. */ |
285 | if (TREE_CODE (ptr1) != SSA_NAME | |
286 | || TREE_CODE (ptr2) != SSA_NAME | |
287 | || !POINTER_TYPE_P (TREE_TYPE (ptr1)) | |
288 | || !POINTER_TYPE_P (TREE_TYPE (ptr2))) | |
289 | return true; | |
290 | ||
dd277d48 | 291 | /* We may end up with two empty points-to solutions for two same pointers. |
292 | In this case we still want to say both pointers alias, so shortcut | |
293 | that here. */ | |
294 | if (ptr1 == ptr2) | |
295 | return true; | |
81d08033 | 296 | |
dd277d48 | 297 | /* If we do not have useful points-to information for either pointer |
298 | we cannot disambiguate anything else. */ | |
299 | pi1 = SSA_NAME_PTR_INFO (ptr1); | |
300 | pi2 = SSA_NAME_PTR_INFO (ptr2); | |
301 | if (!pi1 || !pi2) | |
302 | return true; | |
81d08033 | 303 | |
2a3ebafa | 304 | /* ??? This does not use TBAA to prune decls from the intersection |
305 | that not both pointers may access. */ | |
dd277d48 | 306 | return pt_solutions_intersect (&pi1->pt, &pi2->pt); |
81d08033 | 307 | } |
308 | ||
047fdd47 | 309 | /* Return true if dereferencing PTR may alias *REF. |
310 | The caller is responsible for applying TBAA to see if PTR | |
311 | may access *REF at all. */ | |
312 | ||
313 | static bool | |
314 | ptr_deref_may_alias_ref_p_1 (tree ptr, ao_ref *ref) | |
315 | { | |
316 | tree base = ao_ref_base (ref); | |
317 | ||
2622064f | 318 | if (TREE_CODE (base) == MEM_REF |
319 | || TREE_CODE (base) == TARGET_MEM_REF) | |
047fdd47 | 320 | return ptr_derefs_may_alias_p (ptr, TREE_OPERAND (base, 0)); |
2622064f | 321 | else if (DECL_P (base)) |
047fdd47 | 322 | return ptr_deref_may_alias_decl_p (ptr, base); |
323 | ||
324 | return true; | |
325 | } | |
326 | ||
8763c223 | 327 | /* Return true whether REF may refer to global memory. */ |
328 | ||
329 | bool | |
330 | ref_may_alias_global_p (tree ref) | |
331 | { | |
332 | tree base = get_base_address (ref); | |
333 | if (DECL_P (base)) | |
334 | return is_global_var (base); | |
335 | else if (TREE_CODE (base) == MEM_REF | |
336 | || TREE_CODE (base) == TARGET_MEM_REF) | |
337 | return ptr_deref_may_alias_global_p (TREE_OPERAND (base, 0)); | |
338 | return true; | |
339 | } | |
340 | ||
341 | /* Return true whether STMT may clobber global memory. */ | |
342 | ||
343 | bool | |
344 | stmt_may_clobber_global_p (gimple stmt) | |
345 | { | |
346 | tree lhs; | |
347 | ||
348 | if (!gimple_vdef (stmt)) | |
349 | return false; | |
350 | ||
351 | /* ??? We can ask the oracle whether an artificial pointer | |
352 | dereference with a pointer with points-to information covering | |
353 | all global memory (what about non-address taken memory?) maybe | |
354 | clobbered by this call. As there is at the moment no convenient | |
355 | way of doing that without generating garbage do some manual | |
356 | checking instead. | |
357 | ??? We could make a NULL ao_ref argument to the various | |
358 | predicates special, meaning any global memory. */ | |
359 | ||
360 | switch (gimple_code (stmt)) | |
361 | { | |
362 | case GIMPLE_ASSIGN: | |
363 | lhs = gimple_assign_lhs (stmt); | |
364 | return (TREE_CODE (lhs) != SSA_NAME | |
365 | && ref_may_alias_global_p (lhs)); | |
366 | case GIMPLE_CALL: | |
367 | return true; | |
368 | default: | |
369 | return true; | |
370 | } | |
371 | } | |
372 | ||
4ee9c684 | 373 | |
374 | /* Dump alias information on FILE. */ | |
375 | ||
376 | void | |
377 | dump_alias_info (FILE *file) | |
378 | { | |
2aac21c5 | 379 | unsigned i; |
4ee9c684 | 380 | const char *funcname |
5135beeb | 381 | = lang_hooks.decl_printable_name (current_function_decl, 2); |
a55dc2cd | 382 | tree var; |
4ee9c684 | 383 | |
dd277d48 | 384 | fprintf (file, "\n\nAlias information for %s\n\n", funcname); |
81d08033 | 385 | |
386 | fprintf (file, "Aliased symbols\n\n"); | |
48e1416a | 387 | |
2aac21c5 | 388 | FOR_EACH_LOCAL_DECL (cfun, i, var) |
81d08033 | 389 | { |
81d08033 | 390 | if (may_be_aliased (var)) |
391 | dump_variable (file, var); | |
392 | } | |
393 | ||
7f81b5ee | 394 | fprintf (file, "\nCall clobber information\n"); |
395 | ||
396 | fprintf (file, "\nESCAPED"); | |
397 | dump_points_to_solution (file, &cfun->gimple_df->escaped); | |
7f81b5ee | 398 | |
399 | fprintf (file, "\n\nFlow-insensitive points-to information\n\n"); | |
81d08033 | 400 | |
81d08033 | 401 | for (i = 1; i < num_ssa_names; i++) |
402 | { | |
403 | tree ptr = ssa_name (i); | |
a48b1470 | 404 | struct ptr_info_def *pi; |
48e1416a | 405 | |
dd277d48 | 406 | if (ptr == NULL_TREE |
407 | || SSA_NAME_IN_FREE_LIST (ptr)) | |
a48b1470 | 408 | continue; |
409 | ||
410 | pi = SSA_NAME_PTR_INFO (ptr); | |
dd277d48 | 411 | if (pi) |
81d08033 | 412 | dump_points_to_info_for (file, ptr); |
413 | } | |
4ee9c684 | 414 | |
4ee9c684 | 415 | fprintf (file, "\n"); |
416 | } | |
417 | ||
418 | ||
419 | /* Dump alias information on stderr. */ | |
420 | ||
4b987fac | 421 | DEBUG_FUNCTION void |
4ee9c684 | 422 | debug_alias_info (void) |
423 | { | |
424 | dump_alias_info (stderr); | |
425 | } | |
426 | ||
427 | ||
7f81b5ee | 428 | /* Dump the points-to set *PT into FILE. */ |
4ee9c684 | 429 | |
d793732c | 430 | void |
7f81b5ee | 431 | dump_points_to_solution (FILE *file, struct pt_solution *pt) |
4ee9c684 | 432 | { |
7f81b5ee | 433 | if (pt->anything) |
434 | fprintf (file, ", points-to anything"); | |
4ee9c684 | 435 | |
7f81b5ee | 436 | if (pt->nonlocal) |
437 | fprintf (file, ", points-to non-local"); | |
4ee9c684 | 438 | |
7f81b5ee | 439 | if (pt->escaped) |
440 | fprintf (file, ", points-to escaped"); | |
441 | ||
1a981e1a | 442 | if (pt->ipa_escaped) |
443 | fprintf (file, ", points-to unit escaped"); | |
444 | ||
7f81b5ee | 445 | if (pt->null) |
446 | fprintf (file, ", points-to NULL"); | |
447 | ||
448 | if (pt->vars) | |
4ee9c684 | 449 | { |
7f81b5ee | 450 | fprintf (file, ", points-to vars: "); |
451 | dump_decl_set (file, pt->vars); | |
452 | if (pt->vars_contains_global) | |
453 | fprintf (file, " (includes global vars)"); | |
454 | } | |
455 | } | |
4ee9c684 | 456 | |
c7d89805 | 457 | |
458 | /* Unified dump function for pt_solution. */ | |
459 | ||
460 | DEBUG_FUNCTION void | |
461 | debug (pt_solution &ref) | |
462 | { | |
463 | dump_points_to_solution (stderr, &ref); | |
464 | } | |
465 | ||
466 | DEBUG_FUNCTION void | |
467 | debug (pt_solution *ptr) | |
468 | { | |
469 | if (ptr) | |
470 | debug (*ptr); | |
471 | else | |
472 | fprintf (stderr, "<nil>\n"); | |
473 | } | |
474 | ||
475 | ||
7f81b5ee | 476 | /* Dump points-to information for SSA_NAME PTR into FILE. */ |
4ee9c684 | 477 | |
7f81b5ee | 478 | void |
479 | dump_points_to_info_for (FILE *file, tree ptr) | |
480 | { | |
481 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr); | |
4ee9c684 | 482 | |
7f81b5ee | 483 | print_generic_expr (file, ptr, dump_flags); |
1e1a4c8c | 484 | |
7f81b5ee | 485 | if (pi) |
486 | dump_points_to_solution (file, &pi->pt); | |
487 | else | |
488 | fprintf (file, ", points-to anything"); | |
4ee9c684 | 489 | |
490 | fprintf (file, "\n"); | |
491 | } | |
492 | ||
493 | ||
d793732c | 494 | /* Dump points-to information for VAR into stderr. */ |
495 | ||
4b987fac | 496 | DEBUG_FUNCTION void |
d793732c | 497 | debug_points_to_info_for (tree var) |
498 | { | |
499 | dump_points_to_info_for (stderr, var); | |
500 | } | |
501 | ||
3918bd18 | 502 | |
503 | /* Initializes the alias-oracle reference representation *R from REF. */ | |
504 | ||
505 | void | |
506 | ao_ref_init (ao_ref *r, tree ref) | |
507 | { | |
508 | r->ref = ref; | |
509 | r->base = NULL_TREE; | |
510 | r->offset = 0; | |
511 | r->size = -1; | |
512 | r->max_size = -1; | |
513 | r->ref_alias_set = -1; | |
514 | r->base_alias_set = -1; | |
3787db52 | 515 | r->volatile_p = ref ? TREE_THIS_VOLATILE (ref) : false; |
3918bd18 | 516 | } |
517 | ||
518 | /* Returns the base object of the memory reference *REF. */ | |
519 | ||
520 | tree | |
521 | ao_ref_base (ao_ref *ref) | |
522 | { | |
523 | if (ref->base) | |
524 | return ref->base; | |
525 | ref->base = get_ref_base_and_extent (ref->ref, &ref->offset, &ref->size, | |
526 | &ref->max_size); | |
527 | return ref->base; | |
528 | } | |
529 | ||
530 | /* Returns the base object alias set of the memory reference *REF. */ | |
531 | ||
182cf5a9 | 532 | static alias_set_type |
3918bd18 | 533 | ao_ref_base_alias_set (ao_ref *ref) |
534 | { | |
182cf5a9 | 535 | tree base_ref; |
3918bd18 | 536 | if (ref->base_alias_set != -1) |
537 | return ref->base_alias_set; | |
182cf5a9 | 538 | if (!ref->ref) |
539 | return 0; | |
540 | base_ref = ref->ref; | |
541 | while (handled_component_p (base_ref)) | |
542 | base_ref = TREE_OPERAND (base_ref, 0); | |
543 | ref->base_alias_set = get_alias_set (base_ref); | |
3918bd18 | 544 | return ref->base_alias_set; |
545 | } | |
546 | ||
547 | /* Returns the reference alias set of the memory reference *REF. */ | |
548 | ||
549 | alias_set_type | |
550 | ao_ref_alias_set (ao_ref *ref) | |
551 | { | |
552 | if (ref->ref_alias_set != -1) | |
553 | return ref->ref_alias_set; | |
554 | ref->ref_alias_set = get_alias_set (ref->ref); | |
555 | return ref->ref_alias_set; | |
556 | } | |
557 | ||
134899ac | 558 | /* Init an alias-oracle reference representation from a gimple pointer |
559 | PTR and a gimple size SIZE in bytes. If SIZE is NULL_TREE the the | |
560 | size is assumed to be unknown. The access is assumed to be only | |
561 | to or after of the pointer target, not before it. */ | |
562 | ||
563 | void | |
564 | ao_ref_init_from_ptr_and_size (ao_ref *ref, tree ptr, tree size) | |
565 | { | |
566 | HOST_WIDE_INT t1, t2; | |
567 | ref->ref = NULL_TREE; | |
568 | if (TREE_CODE (ptr) == ADDR_EXPR) | |
569 | ref->base = get_ref_base_and_extent (TREE_OPERAND (ptr, 0), | |
570 | &ref->offset, &t1, &t2); | |
571 | else | |
572 | { | |
182cf5a9 | 573 | ref->base = build2 (MEM_REF, char_type_node, |
2512209b | 574 | ptr, null_pointer_node); |
134899ac | 575 | ref->offset = 0; |
576 | } | |
577 | if (size | |
578 | && host_integerp (size, 0) | |
579 | && TREE_INT_CST_LOW (size) * 8 / 8 == TREE_INT_CST_LOW (size)) | |
580 | ref->max_size = ref->size = TREE_INT_CST_LOW (size) * 8; | |
581 | else | |
582 | ref->max_size = ref->size = -1; | |
583 | ref->ref_alias_set = 0; | |
584 | ref->base_alias_set = 0; | |
3787db52 | 585 | ref->volatile_p = false; |
134899ac | 586 | } |
587 | ||
dd277d48 | 588 | /* Return 1 if TYPE1 and TYPE2 are to be considered equivalent for the |
589 | purpose of TBAA. Return 0 if they are distinct and -1 if we cannot | |
590 | decide. */ | |
d793732c | 591 | |
dd277d48 | 592 | static inline int |
593 | same_type_for_tbaa (tree type1, tree type2) | |
594 | { | |
595 | type1 = TYPE_MAIN_VARIANT (type1); | |
596 | type2 = TYPE_MAIN_VARIANT (type2); | |
4ee9c684 | 597 | |
dd277d48 | 598 | /* If we would have to do structural comparison bail out. */ |
599 | if (TYPE_STRUCTURAL_EQUALITY_P (type1) | |
600 | || TYPE_STRUCTURAL_EQUALITY_P (type2)) | |
601 | return -1; | |
602 | ||
603 | /* Compare the canonical types. */ | |
604 | if (TYPE_CANONICAL (type1) == TYPE_CANONICAL (type2)) | |
605 | return 1; | |
606 | ||
4b4d1513 | 607 | /* ??? Array types are not properly unified in all cases as we have |
dd277d48 | 608 | spurious changes in the index types for example. Removing this |
609 | causes all sorts of problems with the Fortran frontend. */ | |
610 | if (TREE_CODE (type1) == ARRAY_TYPE | |
611 | && TREE_CODE (type2) == ARRAY_TYPE) | |
612 | return -1; | |
613 | ||
102bfc9c | 614 | /* ??? In Ada, an lvalue of an unconstrained type can be used to access an |
615 | object of one of its constrained subtypes, e.g. when a function with an | |
616 | unconstrained parameter passed by reference is called on an object and | |
617 | inlined. But, even in the case of a fixed size, type and subtypes are | |
618 | not equivalent enough as to share the same TYPE_CANONICAL, since this | |
619 | would mean that conversions between them are useless, whereas they are | |
620 | not (e.g. type and subtypes can have different modes). So, in the end, | |
621 | they are only guaranteed to have the same alias set. */ | |
622 | if (get_alias_set (type1) == get_alias_set (type2)) | |
4b4d1513 | 623 | return -1; |
624 | ||
dd277d48 | 625 | /* The types are known to be not equal. */ |
626 | return 0; | |
627 | } | |
628 | ||
629 | /* Determine if the two component references REF1 and REF2 which are | |
630 | based on access types TYPE1 and TYPE2 and of which at least one is based | |
ac30e3b2 | 631 | on an indirect reference may alias. REF2 is the only one that can |
632 | be a decl in which case REF2_IS_DECL is true. | |
633 | REF1_ALIAS_SET, BASE1_ALIAS_SET, REF2_ALIAS_SET and BASE2_ALIAS_SET | |
634 | are the respective alias sets. */ | |
dd277d48 | 635 | |
636 | static bool | |
0d2f7431 | 637 | aliasing_component_refs_p (tree ref1, |
ac30e3b2 | 638 | alias_set_type ref1_alias_set, |
639 | alias_set_type base1_alias_set, | |
a42ce2cc | 640 | HOST_WIDE_INT offset1, HOST_WIDE_INT max_size1, |
0d2f7431 | 641 | tree ref2, |
ac30e3b2 | 642 | alias_set_type ref2_alias_set, |
643 | alias_set_type base2_alias_set, | |
644 | HOST_WIDE_INT offset2, HOST_WIDE_INT max_size2, | |
645 | bool ref2_is_decl) | |
dd277d48 | 646 | { |
647 | /* If one reference is a component references through pointers try to find a | |
648 | common base and apply offset based disambiguation. This handles | |
649 | for example | |
650 | struct A { int i; int j; } *q; | |
651 | struct B { struct A a; int k; } *p; | |
652 | disambiguating q->i and p->a.j. */ | |
0d2f7431 | 653 | tree base1, base2; |
654 | tree type1, type2; | |
dd277d48 | 655 | tree *refp; |
656 | int same_p; | |
657 | ||
0d2f7431 | 658 | /* Choose bases and base types to search for. */ |
659 | base1 = ref1; | |
660 | while (handled_component_p (base1)) | |
661 | base1 = TREE_OPERAND (base1, 0); | |
662 | type1 = TREE_TYPE (base1); | |
663 | base2 = ref2; | |
664 | while (handled_component_p (base2)) | |
665 | base2 = TREE_OPERAND (base2, 0); | |
666 | type2 = TREE_TYPE (base2); | |
667 | ||
dd277d48 | 668 | /* Now search for the type1 in the access path of ref2. This |
669 | would be a common base for doing offset based disambiguation on. */ | |
bc3c318e | 670 | refp = &ref2; |
dd277d48 | 671 | while (handled_component_p (*refp) |
672 | && same_type_for_tbaa (TREE_TYPE (*refp), type1) == 0) | |
673 | refp = &TREE_OPERAND (*refp, 0); | |
674 | same_p = same_type_for_tbaa (TREE_TYPE (*refp), type1); | |
675 | /* If we couldn't compare types we have to bail out. */ | |
676 | if (same_p == -1) | |
677 | return true; | |
678 | else if (same_p == 1) | |
679 | { | |
680 | HOST_WIDE_INT offadj, sztmp, msztmp; | |
681 | get_ref_base_and_extent (*refp, &offadj, &sztmp, &msztmp); | |
682 | offset2 -= offadj; | |
0d2f7431 | 683 | get_ref_base_and_extent (base1, &offadj, &sztmp, &msztmp); |
684 | offset1 -= offadj; | |
dd277d48 | 685 | return ranges_overlap_p (offset1, max_size1, offset2, max_size2); |
686 | } | |
687 | /* If we didn't find a common base, try the other way around. */ | |
bc3c318e | 688 | refp = &ref1; |
dd277d48 | 689 | while (handled_component_p (*refp) |
690 | && same_type_for_tbaa (TREE_TYPE (*refp), type2) == 0) | |
691 | refp = &TREE_OPERAND (*refp, 0); | |
692 | same_p = same_type_for_tbaa (TREE_TYPE (*refp), type2); | |
693 | /* If we couldn't compare types we have to bail out. */ | |
694 | if (same_p == -1) | |
695 | return true; | |
696 | else if (same_p == 1) | |
697 | { | |
698 | HOST_WIDE_INT offadj, sztmp, msztmp; | |
699 | get_ref_base_and_extent (*refp, &offadj, &sztmp, &msztmp); | |
700 | offset1 -= offadj; | |
0d2f7431 | 701 | get_ref_base_and_extent (base2, &offadj, &sztmp, &msztmp); |
702 | offset2 -= offadj; | |
dd277d48 | 703 | return ranges_overlap_p (offset1, max_size1, offset2, max_size2); |
704 | } | |
ac30e3b2 | 705 | |
4b4d1513 | 706 | /* If we have two type access paths B1.path1 and B2.path2 they may |
ac30e3b2 | 707 | only alias if either B1 is in B2.path2 or B2 is in B1.path1. |
708 | But we can still have a path that goes B1.path1...B2.path2 with | |
709 | a part that we do not see. So we can only disambiguate now | |
710 | if there is no B2 in the tail of path1 and no B1 on the | |
711 | tail of path2. */ | |
712 | if (base1_alias_set == ref2_alias_set | |
713 | || alias_set_subset_of (base1_alias_set, ref2_alias_set)) | |
714 | return true; | |
715 | /* If this is ptr vs. decl then we know there is no ptr ... decl path. */ | |
716 | if (!ref2_is_decl) | |
717 | return (base2_alias_set == ref1_alias_set | |
718 | || alias_set_subset_of (base2_alias_set, ref1_alias_set)); | |
4b4d1513 | 719 | return false; |
dd277d48 | 720 | } |
721 | ||
740a2cb6 | 722 | /* Return true if we can determine that component references REF1 and REF2, |
723 | that are within a common DECL, cannot overlap. */ | |
724 | ||
725 | static bool | |
726 | nonoverlapping_component_refs_of_decl_p (tree ref1, tree ref2) | |
727 | { | |
728 | vec<tree, va_stack> component_refs1; | |
729 | vec<tree, va_stack> component_refs2; | |
730 | ||
731 | vec_stack_alloc (tree, component_refs1, 16); | |
732 | vec_stack_alloc (tree, component_refs2, 16); | |
733 | ||
734 | /* Create the stack of handled components for REF1. */ | |
735 | while (handled_component_p (ref1)) | |
736 | { | |
737 | component_refs1.safe_push (ref1); | |
738 | ref1 = TREE_OPERAND (ref1, 0); | |
739 | } | |
740 | if (TREE_CODE (ref1) == MEM_REF) | |
741 | { | |
742 | if (!integer_zerop (TREE_OPERAND (ref1, 1))) | |
743 | goto may_overlap; | |
744 | ref1 = TREE_OPERAND (TREE_OPERAND (ref1, 0), 0); | |
745 | } | |
746 | ||
747 | /* Create the stack of handled components for REF2. */ | |
748 | while (handled_component_p (ref2)) | |
749 | { | |
750 | component_refs2.safe_push (ref2); | |
751 | ref2 = TREE_OPERAND (ref2, 0); | |
752 | } | |
753 | if (TREE_CODE (ref2) == MEM_REF) | |
754 | { | |
755 | if (!integer_zerop (TREE_OPERAND (ref2, 1))) | |
756 | goto may_overlap; | |
757 | ref2 = TREE_OPERAND (TREE_OPERAND (ref2, 0), 0); | |
758 | } | |
759 | ||
760 | /* We must have the same base DECL. */ | |
761 | gcc_assert (ref1 == ref2); | |
762 | ||
763 | /* Pop the stacks in parallel and examine the COMPONENT_REFs of the same | |
764 | rank. This is sufficient because we start from the same DECL and you | |
765 | cannot reference several fields at a time with COMPONENT_REFs (unlike | |
766 | with ARRAY_RANGE_REFs for arrays) so you always need the same number | |
767 | of them to access a sub-component, unless you're in a union, in which | |
768 | case the return value will precisely be false. */ | |
769 | while (true) | |
770 | { | |
771 | do | |
772 | { | |
773 | if (component_refs1.is_empty ()) | |
774 | goto may_overlap; | |
775 | ref1 = component_refs1.pop (); | |
776 | } | |
777 | while (!RECORD_OR_UNION_TYPE_P (TREE_TYPE (TREE_OPERAND (ref1, 0)))); | |
778 | ||
779 | do | |
780 | { | |
781 | if (component_refs2.is_empty ()) | |
782 | goto may_overlap; | |
783 | ref2 = component_refs2.pop (); | |
784 | } | |
785 | while (!RECORD_OR_UNION_TYPE_P (TREE_TYPE (TREE_OPERAND (ref2, 0)))); | |
786 | ||
787 | /* Beware of BIT_FIELD_REF. */ | |
788 | if (TREE_CODE (ref1) != COMPONENT_REF | |
789 | || TREE_CODE (ref2) != COMPONENT_REF) | |
790 | goto may_overlap; | |
791 | ||
792 | tree field1 = TREE_OPERAND (ref1, 1); | |
793 | tree field2 = TREE_OPERAND (ref2, 1); | |
794 | ||
795 | /* ??? We cannot simply use the type of operand #0 of the refs here | |
796 | as the Fortran compiler smuggles type punning into COMPONENT_REFs | |
797 | for common blocks instead of using unions like everyone else. */ | |
798 | tree type1 = TYPE_MAIN_VARIANT (DECL_CONTEXT (field1)); | |
799 | tree type2 = TYPE_MAIN_VARIANT (DECL_CONTEXT (field2)); | |
800 | ||
801 | /* We cannot disambiguate fields in a union or qualified union. */ | |
802 | if (type1 != type2 || TREE_CODE (type1) != RECORD_TYPE) | |
803 | goto may_overlap; | |
804 | ||
805 | /* Different fields of the same record type cannot overlap. */ | |
806 | if (field1 != field2) | |
807 | { | |
808 | component_refs1.release (); | |
809 | component_refs2.release (); | |
810 | return true; | |
811 | } | |
812 | } | |
813 | ||
814 | may_overlap: | |
815 | component_refs1.release (); | |
816 | component_refs2.release (); | |
817 | return false; | |
818 | } | |
819 | ||
dd277d48 | 820 | /* Return true if two memory references based on the variables BASE1 |
077ad5ad | 821 | and BASE2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and |
740a2cb6 | 822 | [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. REF1 and REF2 |
823 | if non-NULL are the complete memory reference trees. */ | |
dd277d48 | 824 | |
825 | static bool | |
740a2cb6 | 826 | decl_refs_may_alias_p (tree ref1, tree base1, |
dd277d48 | 827 | HOST_WIDE_INT offset1, HOST_WIDE_INT max_size1, |
740a2cb6 | 828 | tree ref2, tree base2, |
dd277d48 | 829 | HOST_WIDE_INT offset2, HOST_WIDE_INT max_size2) |
4ee9c684 | 830 | { |
2622064f | 831 | gcc_checking_assert (DECL_P (base1) && DECL_P (base2)); |
4ee9c684 | 832 | |
dd277d48 | 833 | /* If both references are based on different variables, they cannot alias. */ |
7f2d9047 | 834 | if (base1 != base2) |
dd277d48 | 835 | return false; |
4ee9c684 | 836 | |
dd277d48 | 837 | /* If both references are based on the same variable, they cannot alias if |
838 | the accesses do not overlap. */ | |
740a2cb6 | 839 | if (!ranges_overlap_p (offset1, max_size1, offset2, max_size2)) |
840 | return false; | |
841 | ||
842 | /* For components with variable position, the above test isn't sufficient, | |
843 | so we disambiguate component references manually. */ | |
844 | if (ref1 && ref2 | |
845 | && handled_component_p (ref1) && handled_component_p (ref2) | |
846 | && nonoverlapping_component_refs_of_decl_p (ref1, ref2)) | |
847 | return false; | |
848 | ||
849 | return true; | |
dd277d48 | 850 | } |
851 | ||
852 | /* Return true if an indirect reference based on *PTR1 constrained | |
077ad5ad | 853 | to [OFFSET1, OFFSET1 + MAX_SIZE1) may alias a variable based on BASE2 |
854 | constrained to [OFFSET2, OFFSET2 + MAX_SIZE2). *PTR1 and BASE2 have | |
dd277d48 | 855 | the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1 |
856 | in which case they are computed on-demand. REF1 and REF2 | |
857 | if non-NULL are the complete memory reference trees. */ | |
858 | ||
859 | static bool | |
182cf5a9 | 860 | indirect_ref_may_alias_decl_p (tree ref1 ATTRIBUTE_UNUSED, tree base1, |
861 | HOST_WIDE_INT offset1, | |
862 | HOST_WIDE_INT max_size1 ATTRIBUTE_UNUSED, | |
ac30e3b2 | 863 | alias_set_type ref1_alias_set, |
dd277d48 | 864 | alias_set_type base1_alias_set, |
182cf5a9 | 865 | tree ref2 ATTRIBUTE_UNUSED, tree base2, |
dd277d48 | 866 | HOST_WIDE_INT offset2, HOST_WIDE_INT max_size2, |
ac30e3b2 | 867 | alias_set_type ref2_alias_set, |
182cf5a9 | 868 | alias_set_type base2_alias_set, bool tbaa_p) |
dd277d48 | 869 | { |
9a14ba4f | 870 | tree ptr1; |
061b1263 | 871 | tree ptrtype1, dbase2; |
7749ee1c | 872 | HOST_WIDE_INT offset1p = offset1, offset2p = offset2; |
061b1263 | 873 | HOST_WIDE_INT doffset1, doffset2; |
2622064f | 874 | double_int moff; |
875 | ||
876 | gcc_checking_assert ((TREE_CODE (base1) == MEM_REF | |
877 | || TREE_CODE (base1) == TARGET_MEM_REF) | |
878 | && DECL_P (base2)); | |
182cf5a9 | 879 | |
28daba6f | 880 | ptr1 = TREE_OPERAND (base1, 0); |
9a14ba4f | 881 | |
7749ee1c | 882 | /* The offset embedded in MEM_REFs can be negative. Bias them |
883 | so that the resulting offset adjustment is positive. */ | |
2622064f | 884 | moff = mem_ref_offset (base1); |
9a8b9e26 | 885 | moff = moff.lshift (BITS_PER_UNIT == 8 ? 3 : exact_log2 (BITS_PER_UNIT)); |
cf8f0e63 | 886 | if (moff.is_negative ()) |
887 | offset2p += (-moff).low; | |
2622064f | 888 | else |
889 | offset1p += moff.low; | |
182cf5a9 | 890 | |
dd277d48 | 891 | /* If only one reference is based on a variable, they cannot alias if |
892 | the pointer access is beyond the extent of the variable access. | |
893 | (the pointer base cannot validly point to an offset less than zero | |
894 | of the variable). | |
a07f6629 | 895 | ??? IVOPTs creates bases that do not honor this restriction, |
896 | so do not apply this optimization for TARGET_MEM_REFs. */ | |
897 | if (TREE_CODE (base1) != TARGET_MEM_REF | |
9a14ba4f | 898 | && !ranges_overlap_p (MAX (0, offset1p), -1, offset2p, max_size2)) |
dd277d48 | 899 | return false; |
a07f6629 | 900 | /* They also cannot alias if the pointer may not point to the decl. */ |
dd277d48 | 901 | if (!ptr_deref_may_alias_decl_p (ptr1, base2)) |
902 | return false; | |
903 | ||
904 | /* Disambiguations that rely on strict aliasing rules follow. */ | |
182cf5a9 | 905 | if (!flag_strict_aliasing || !tbaa_p) |
dd277d48 | 906 | return true; |
907 | ||
2622064f | 908 | ptrtype1 = TREE_TYPE (TREE_OPERAND (base1, 1)); |
182cf5a9 | 909 | |
dd277d48 | 910 | /* If the alias set for a pointer access is zero all bets are off. */ |
911 | if (base1_alias_set == -1) | |
182cf5a9 | 912 | base1_alias_set = get_deref_alias_set (ptrtype1); |
dd277d48 | 913 | if (base1_alias_set == 0) |
914 | return true; | |
915 | if (base2_alias_set == -1) | |
916 | base2_alias_set = get_alias_set (base2); | |
917 | ||
182cf5a9 | 918 | /* When we are trying to disambiguate an access with a pointer dereference |
919 | as base versus one with a decl as base we can use both the size | |
920 | of the decl and its dynamic type for extra disambiguation. | |
921 | ??? We do not know anything about the dynamic type of the decl | |
922 | other than that its alias-set contains base2_alias_set as a subset | |
923 | which does not help us here. */ | |
924 | /* As we know nothing useful about the dynamic type of the decl just | |
925 | use the usual conflict check rather than a subset test. | |
926 | ??? We could introduce -fvery-strict-aliasing when the language | |
927 | does not allow decls to have a dynamic type that differs from their | |
928 | static type. Then we can check | |
929 | !alias_set_subset_of (base1_alias_set, base2_alias_set) instead. */ | |
dd277d48 | 930 | if (base1_alias_set != base2_alias_set |
182cf5a9 | 931 | && !alias_sets_conflict_p (base1_alias_set, base2_alias_set)) |
932 | return false; | |
933 | /* If the size of the access relevant for TBAA through the pointer | |
934 | is bigger than the size of the decl we can't possibly access the | |
935 | decl via that pointer. */ | |
936 | if (DECL_SIZE (base2) && COMPLETE_TYPE_P (TREE_TYPE (ptrtype1)) | |
937 | && TREE_CODE (DECL_SIZE (base2)) == INTEGER_CST | |
938 | && TREE_CODE (TYPE_SIZE (TREE_TYPE (ptrtype1))) == INTEGER_CST | |
939 | /* ??? This in turn may run afoul when a decl of type T which is | |
940 | a member of union type U is accessed through a pointer to | |
941 | type U and sizeof T is smaller than sizeof U. */ | |
942 | && TREE_CODE (TREE_TYPE (ptrtype1)) != UNION_TYPE | |
943 | && TREE_CODE (TREE_TYPE (ptrtype1)) != QUAL_UNION_TYPE | |
944 | && tree_int_cst_lt (DECL_SIZE (base2), TYPE_SIZE (TREE_TYPE (ptrtype1)))) | |
dd277d48 | 945 | return false; |
946 | ||
061b1263 | 947 | if (!ref2) |
948 | return true; | |
949 | ||
a07f6629 | 950 | /* If the decl is accessed via a MEM_REF, reconstruct the base |
061b1263 | 951 | we can use for TBAA and an appropriately adjusted offset. */ |
952 | dbase2 = ref2; | |
953 | while (handled_component_p (dbase2)) | |
954 | dbase2 = TREE_OPERAND (dbase2, 0); | |
955 | doffset1 = offset1; | |
956 | doffset2 = offset2; | |
957 | if (TREE_CODE (dbase2) == MEM_REF | |
958 | || TREE_CODE (dbase2) == TARGET_MEM_REF) | |
959 | { | |
960 | double_int moff = mem_ref_offset (dbase2); | |
9a8b9e26 | 961 | moff = moff.lshift (BITS_PER_UNIT == 8 ? 3 : exact_log2 (BITS_PER_UNIT)); |
cf8f0e63 | 962 | if (moff.is_negative ()) |
963 | doffset1 -= (-moff).low; | |
061b1263 | 964 | else |
965 | doffset2 -= moff.low; | |
966 | } | |
967 | ||
968 | /* If either reference is view-converted, give up now. */ | |
969 | if (same_type_for_tbaa (TREE_TYPE (base1), TREE_TYPE (ptrtype1)) != 1 | |
5ef4302d | 970 | || same_type_for_tbaa (TREE_TYPE (dbase2), TREE_TYPE (base2)) != 1) |
061b1263 | 971 | return true; |
972 | ||
973 | /* If both references are through the same type, they do not alias | |
974 | if the accesses do not overlap. This does extra disambiguation | |
975 | for mixed/pointer accesses but requires strict aliasing. | |
976 | For MEM_REFs we require that the component-ref offset we computed | |
977 | is relative to the start of the type which we ensure by | |
978 | comparing rvalue and access type and disregarding the constant | |
979 | pointer offset. */ | |
980 | if ((TREE_CODE (base1) != TARGET_MEM_REF | |
981 | || (!TMR_INDEX (base1) && !TMR_INDEX2 (base1))) | |
982 | && same_type_for_tbaa (TREE_TYPE (base1), TREE_TYPE (dbase2)) == 1) | |
983 | return ranges_overlap_p (doffset1, max_size1, doffset2, max_size2); | |
984 | ||
dd277d48 | 985 | /* Do access-path based disambiguation. */ |
986 | if (ref1 && ref2 | |
061b1263 | 987 | && (handled_component_p (ref1) || handled_component_p (ref2))) |
0d2f7431 | 988 | return aliasing_component_refs_p (ref1, |
ac30e3b2 | 989 | ref1_alias_set, base1_alias_set, |
a42ce2cc | 990 | offset1, max_size1, |
0d2f7431 | 991 | ref2, |
ac30e3b2 | 992 | ref2_alias_set, base2_alias_set, |
993 | offset2, max_size2, true); | |
dd277d48 | 994 | |
995 | return true; | |
996 | } | |
997 | ||
998 | /* Return true if two indirect references based on *PTR1 | |
077ad5ad | 999 | and *PTR2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and |
1000 | [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. *PTR1 and *PTR2 have | |
dd277d48 | 1001 | the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1 |
1002 | in which case they are computed on-demand. REF1 and REF2 | |
1003 | if non-NULL are the complete memory reference trees. */ | |
1004 | ||
1005 | static bool | |
182cf5a9 | 1006 | indirect_refs_may_alias_p (tree ref1 ATTRIBUTE_UNUSED, tree base1, |
dd277d48 | 1007 | HOST_WIDE_INT offset1, HOST_WIDE_INT max_size1, |
ac30e3b2 | 1008 | alias_set_type ref1_alias_set, |
dd277d48 | 1009 | alias_set_type base1_alias_set, |
182cf5a9 | 1010 | tree ref2 ATTRIBUTE_UNUSED, tree base2, |
dd277d48 | 1011 | HOST_WIDE_INT offset2, HOST_WIDE_INT max_size2, |
ac30e3b2 | 1012 | alias_set_type ref2_alias_set, |
182cf5a9 | 1013 | alias_set_type base2_alias_set, bool tbaa_p) |
dd277d48 | 1014 | { |
9a14ba4f | 1015 | tree ptr1; |
1016 | tree ptr2; | |
182cf5a9 | 1017 | tree ptrtype1, ptrtype2; |
1018 | ||
2622064f | 1019 | gcc_checking_assert ((TREE_CODE (base1) == MEM_REF |
1020 | || TREE_CODE (base1) == TARGET_MEM_REF) | |
1021 | && (TREE_CODE (base2) == MEM_REF | |
1022 | || TREE_CODE (base2) == TARGET_MEM_REF)); | |
1023 | ||
28daba6f | 1024 | ptr1 = TREE_OPERAND (base1, 0); |
1025 | ptr2 = TREE_OPERAND (base2, 0); | |
9a14ba4f | 1026 | |
dd277d48 | 1027 | /* If both bases are based on pointers they cannot alias if they may not |
1028 | point to the same memory object or if they point to the same object | |
1029 | and the accesses do not overlap. */ | |
b5c3c805 | 1030 | if ((!cfun || gimple_in_ssa_p (cfun)) |
9a14ba4f | 1031 | && operand_equal_p (ptr1, ptr2, 0) |
1032 | && (((TREE_CODE (base1) != TARGET_MEM_REF | |
88be3999 | 1033 | || (!TMR_INDEX (base1) && !TMR_INDEX2 (base1))) |
9a14ba4f | 1034 | && (TREE_CODE (base2) != TARGET_MEM_REF |
88be3999 | 1035 | || (!TMR_INDEX (base2) && !TMR_INDEX2 (base2)))) |
9a14ba4f | 1036 | || (TREE_CODE (base1) == TARGET_MEM_REF |
1037 | && TREE_CODE (base2) == TARGET_MEM_REF | |
1038 | && (TMR_STEP (base1) == TMR_STEP (base2) | |
1039 | || (TMR_STEP (base1) && TMR_STEP (base2) | |
1040 | && operand_equal_p (TMR_STEP (base1), | |
1041 | TMR_STEP (base2), 0))) | |
88be3999 | 1042 | && (TMR_INDEX (base1) == TMR_INDEX (base2) |
1043 | || (TMR_INDEX (base1) && TMR_INDEX (base2) | |
1044 | && operand_equal_p (TMR_INDEX (base1), | |
1045 | TMR_INDEX (base2), 0))) | |
1046 | && (TMR_INDEX2 (base1) == TMR_INDEX2 (base2) | |
1047 | || (TMR_INDEX2 (base1) && TMR_INDEX2 (base2) | |
1048 | && operand_equal_p (TMR_INDEX2 (base1), | |
1049 | TMR_INDEX2 (base2), 0)))))) | |
182cf5a9 | 1050 | { |
2622064f | 1051 | double_int moff; |
7749ee1c | 1052 | /* The offset embedded in MEM_REFs can be negative. Bias them |
1053 | so that the resulting offset adjustment is positive. */ | |
2622064f | 1054 | moff = mem_ref_offset (base1); |
9a8b9e26 | 1055 | moff = moff.lshift (BITS_PER_UNIT == 8 ? 3 : exact_log2 (BITS_PER_UNIT)); |
cf8f0e63 | 1056 | if (moff.is_negative ()) |
1057 | offset2 += (-moff).low; | |
2622064f | 1058 | else |
1059 | offset1 += moff.low; | |
1060 | moff = mem_ref_offset (base2); | |
9a8b9e26 | 1061 | moff = moff.lshift (BITS_PER_UNIT == 8 ? 3 : exact_log2 (BITS_PER_UNIT)); |
cf8f0e63 | 1062 | if (moff.is_negative ()) |
1063 | offset1 += (-moff).low; | |
2622064f | 1064 | else |
1065 | offset2 += moff.low; | |
182cf5a9 | 1066 | return ranges_overlap_p (offset1, max_size1, offset2, max_size2); |
1067 | } | |
dd277d48 | 1068 | if (!ptr_derefs_may_alias_p (ptr1, ptr2)) |
1069 | return false; | |
1070 | ||
1071 | /* Disambiguations that rely on strict aliasing rules follow. */ | |
182cf5a9 | 1072 | if (!flag_strict_aliasing || !tbaa_p) |
dd277d48 | 1073 | return true; |
1074 | ||
2622064f | 1075 | ptrtype1 = TREE_TYPE (TREE_OPERAND (base1, 1)); |
1076 | ptrtype2 = TREE_TYPE (TREE_OPERAND (base2, 1)); | |
182cf5a9 | 1077 | |
dd277d48 | 1078 | /* If the alias set for a pointer access is zero all bets are off. */ |
1079 | if (base1_alias_set == -1) | |
182cf5a9 | 1080 | base1_alias_set = get_deref_alias_set (ptrtype1); |
dd277d48 | 1081 | if (base1_alias_set == 0) |
1082 | return true; | |
1083 | if (base2_alias_set == -1) | |
182cf5a9 | 1084 | base2_alias_set = get_deref_alias_set (ptrtype2); |
dd277d48 | 1085 | if (base2_alias_set == 0) |
1086 | return true; | |
1087 | ||
1088 | /* If both references are through the same type, they do not alias | |
1089 | if the accesses do not overlap. This does extra disambiguation | |
1090 | for mixed/pointer accesses but requires strict aliasing. */ | |
9c455d1e | 1091 | if ((TREE_CODE (base1) != TARGET_MEM_REF |
1092 | || (!TMR_INDEX (base1) && !TMR_INDEX2 (base1))) | |
1093 | && (TREE_CODE (base2) != TARGET_MEM_REF | |
1094 | || (!TMR_INDEX (base2) && !TMR_INDEX2 (base2))) | |
1095 | && same_type_for_tbaa (TREE_TYPE (base1), TREE_TYPE (ptrtype1)) == 1 | |
1096 | && same_type_for_tbaa (TREE_TYPE (base2), TREE_TYPE (ptrtype2)) == 1 | |
182cf5a9 | 1097 | && same_type_for_tbaa (TREE_TYPE (ptrtype1), |
1098 | TREE_TYPE (ptrtype2)) == 1) | |
dd277d48 | 1099 | return ranges_overlap_p (offset1, max_size1, offset2, max_size2); |
1100 | ||
1101 | /* Do type-based disambiguation. */ | |
1102 | if (base1_alias_set != base2_alias_set | |
1103 | && !alias_sets_conflict_p (base1_alias_set, base2_alias_set)) | |
1104 | return false; | |
1105 | ||
1106 | /* Do access-path based disambiguation. */ | |
1107 | if (ref1 && ref2 | |
9c455d1e | 1108 | && (handled_component_p (ref1) || handled_component_p (ref2)) |
1109 | && same_type_for_tbaa (TREE_TYPE (base1), TREE_TYPE (ptrtype1)) == 1 | |
1110 | && same_type_for_tbaa (TREE_TYPE (base2), TREE_TYPE (ptrtype2)) == 1) | |
0d2f7431 | 1111 | return aliasing_component_refs_p (ref1, |
ac30e3b2 | 1112 | ref1_alias_set, base1_alias_set, |
a42ce2cc | 1113 | offset1, max_size1, |
0d2f7431 | 1114 | ref2, |
ac30e3b2 | 1115 | ref2_alias_set, base2_alias_set, |
1116 | offset2, max_size2, false); | |
dd277d48 | 1117 | |
1118 | return true; | |
1119 | } | |
1120 | ||
1121 | /* Return true, if the two memory references REF1 and REF2 may alias. */ | |
1122 | ||
3a443843 | 1123 | bool |
3918bd18 | 1124 | refs_may_alias_p_1 (ao_ref *ref1, ao_ref *ref2, bool tbaa_p) |
dd277d48 | 1125 | { |
1126 | tree base1, base2; | |
1127 | HOST_WIDE_INT offset1 = 0, offset2 = 0; | |
dd277d48 | 1128 | HOST_WIDE_INT max_size1 = -1, max_size2 = -1; |
1129 | bool var1_p, var2_p, ind1_p, ind2_p; | |
1130 | ||
c78d5cec | 1131 | gcc_checking_assert ((!ref1->ref |
8e7c2b9c | 1132 | || TREE_CODE (ref1->ref) == SSA_NAME |
c78d5cec | 1133 | || DECL_P (ref1->ref) |
2760c0e3 | 1134 | || TREE_CODE (ref1->ref) == STRING_CST |
c78d5cec | 1135 | || handled_component_p (ref1->ref) |
182cf5a9 | 1136 | || TREE_CODE (ref1->ref) == MEM_REF |
c78d5cec | 1137 | || TREE_CODE (ref1->ref) == TARGET_MEM_REF) |
1138 | && (!ref2->ref | |
8e7c2b9c | 1139 | || TREE_CODE (ref2->ref) == SSA_NAME |
c78d5cec | 1140 | || DECL_P (ref2->ref) |
2760c0e3 | 1141 | || TREE_CODE (ref2->ref) == STRING_CST |
c78d5cec | 1142 | || handled_component_p (ref2->ref) |
182cf5a9 | 1143 | || TREE_CODE (ref2->ref) == MEM_REF |
c78d5cec | 1144 | || TREE_CODE (ref2->ref) == TARGET_MEM_REF)); |
dd277d48 | 1145 | |
dd277d48 | 1146 | /* Decompose the references into their base objects and the access. */ |
3918bd18 | 1147 | base1 = ao_ref_base (ref1); |
1148 | offset1 = ref1->offset; | |
3918bd18 | 1149 | max_size1 = ref1->max_size; |
1150 | base2 = ao_ref_base (ref2); | |
1151 | offset2 = ref2->offset; | |
3918bd18 | 1152 | max_size2 = ref2->max_size; |
dd277d48 | 1153 | |
1154 | /* We can end up with registers or constants as bases for example from | |
1155 | *D.1663_44 = VIEW_CONVERT_EXPR<struct DB_LSN>(__tmp$B0F64_59); | |
1156 | which is seen as a struct copy. */ | |
1157 | if (TREE_CODE (base1) == SSA_NAME | |
119147d1 | 1158 | || TREE_CODE (base1) == CONST_DECL |
66b86a74 | 1159 | || TREE_CODE (base1) == CONSTRUCTOR |
1160 | || TREE_CODE (base1) == ADDR_EXPR | |
1161 | || CONSTANT_CLASS_P (base1) | |
1162 | || TREE_CODE (base2) == SSA_NAME | |
119147d1 | 1163 | || TREE_CODE (base2) == CONST_DECL |
66b86a74 | 1164 | || TREE_CODE (base2) == CONSTRUCTOR |
1165 | || TREE_CODE (base2) == ADDR_EXPR | |
1166 | || CONSTANT_CLASS_P (base2)) | |
dd277d48 | 1167 | return false; |
1168 | ||
04ec15fa | 1169 | /* We can end up referring to code via function and label decls. |
c78d5cec | 1170 | As we likely do not properly track code aliases conservatively |
1171 | bail out. */ | |
ceefbccc | 1172 | if (TREE_CODE (base1) == FUNCTION_DECL |
c78d5cec | 1173 | || TREE_CODE (base1) == LABEL_DECL |
66b86a74 | 1174 | || TREE_CODE (base2) == FUNCTION_DECL |
c78d5cec | 1175 | || TREE_CODE (base2) == LABEL_DECL) |
ceefbccc | 1176 | return true; |
1177 | ||
3787db52 | 1178 | /* Two volatile accesses always conflict. */ |
1179 | if (ref1->volatile_p | |
1180 | && ref2->volatile_p) | |
1181 | return true; | |
1182 | ||
090a8c65 | 1183 | /* Defer to simple offset based disambiguation if we have |
1184 | references based on two decls. Do this before defering to | |
1185 | TBAA to handle must-alias cases in conformance with the | |
1186 | GCC extension of allowing type-punning through unions. */ | |
2622064f | 1187 | var1_p = DECL_P (base1); |
1188 | var2_p = DECL_P (base2); | |
dd277d48 | 1189 | if (var1_p && var2_p) |
740a2cb6 | 1190 | return decl_refs_may_alias_p (ref1->ref, base1, offset1, max_size1, |
1191 | ref2->ref, base2, offset2, max_size2); | |
090a8c65 | 1192 | |
2622064f | 1193 | ind1_p = (TREE_CODE (base1) == MEM_REF |
1194 | || TREE_CODE (base1) == TARGET_MEM_REF); | |
1195 | ind2_p = (TREE_CODE (base2) == MEM_REF | |
1196 | || TREE_CODE (base2) == TARGET_MEM_REF); | |
182cf5a9 | 1197 | |
67817f0f | 1198 | /* Canonicalize the pointer-vs-decl case. */ |
1199 | if (ind1_p && var2_p) | |
1200 | { | |
1201 | HOST_WIDE_INT tmp1; | |
1202 | tree tmp2; | |
1203 | ao_ref *tmp3; | |
1204 | tmp1 = offset1; offset1 = offset2; offset2 = tmp1; | |
1205 | tmp1 = max_size1; max_size1 = max_size2; max_size2 = tmp1; | |
1206 | tmp2 = base1; base1 = base2; base2 = tmp2; | |
1207 | tmp3 = ref1; ref1 = ref2; ref2 = tmp3; | |
1208 | var1_p = true; | |
1209 | ind1_p = false; | |
1210 | var2_p = false; | |
1211 | ind2_p = true; | |
1212 | } | |
1213 | ||
090a8c65 | 1214 | /* First defer to TBAA if possible. */ |
2a3ebafa | 1215 | if (tbaa_p |
1216 | && flag_strict_aliasing | |
3918bd18 | 1217 | && !alias_sets_conflict_p (ao_ref_alias_set (ref1), |
1218 | ao_ref_alias_set (ref2))) | |
090a8c65 | 1219 | return false; |
1220 | ||
090a8c65 | 1221 | /* Dispatch to the pointer-vs-decl or pointer-vs-pointer disambiguators. */ |
090a8c65 | 1222 | if (var1_p && ind2_p) |
182cf5a9 | 1223 | return indirect_ref_may_alias_decl_p (ref2->ref, base2, |
ac30e3b2 | 1224 | offset2, max_size2, |
182cf5a9 | 1225 | ao_ref_alias_set (ref2), -1, |
3918bd18 | 1226 | ref1->ref, base1, |
ac30e3b2 | 1227 | offset1, max_size1, |
182cf5a9 | 1228 | ao_ref_alias_set (ref1), |
1229 | ao_ref_base_alias_set (ref1), | |
1230 | tbaa_p); | |
dd277d48 | 1231 | else if (ind1_p && ind2_p) |
182cf5a9 | 1232 | return indirect_refs_may_alias_p (ref1->ref, base1, |
ac30e3b2 | 1233 | offset1, max_size1, |
182cf5a9 | 1234 | ao_ref_alias_set (ref1), -1, |
1235 | ref2->ref, base2, | |
ac30e3b2 | 1236 | offset2, max_size2, |
182cf5a9 | 1237 | ao_ref_alias_set (ref2), -1, |
1238 | tbaa_p); | |
dd277d48 | 1239 | |
9c01641d | 1240 | /* We really do not want to end up here, but returning true is safe. */ |
1241 | #ifdef ENABLE_CHECKING | |
dd277d48 | 1242 | gcc_unreachable (); |
9c01641d | 1243 | #else |
1244 | return true; | |
1245 | #endif | |
dd277d48 | 1246 | } |
1247 | ||
1248 | bool | |
1249 | refs_may_alias_p (tree ref1, tree ref2) | |
1250 | { | |
3918bd18 | 1251 | ao_ref r1, r2; |
1252 | bool res; | |
1253 | ao_ref_init (&r1, ref1); | |
1254 | ao_ref_init (&r2, ref2); | |
1255 | res = refs_may_alias_p_1 (&r1, &r2, true); | |
dd277d48 | 1256 | if (res) |
1257 | ++alias_stats.refs_may_alias_p_may_alias; | |
1258 | else | |
1259 | ++alias_stats.refs_may_alias_p_no_alias; | |
1260 | return res; | |
1261 | } | |
1262 | ||
2a3ebafa | 1263 | /* Returns true if there is a anti-dependence for the STORE that |
1264 | executes after the LOAD. */ | |
1265 | ||
1266 | bool | |
1267 | refs_anti_dependent_p (tree load, tree store) | |
1268 | { | |
3918bd18 | 1269 | ao_ref r1, r2; |
1270 | ao_ref_init (&r1, load); | |
1271 | ao_ref_init (&r2, store); | |
1272 | return refs_may_alias_p_1 (&r1, &r2, false); | |
2a3ebafa | 1273 | } |
1274 | ||
1275 | /* Returns true if there is a output dependence for the stores | |
1276 | STORE1 and STORE2. */ | |
1277 | ||
1278 | bool | |
1279 | refs_output_dependent_p (tree store1, tree store2) | |
1280 | { | |
3918bd18 | 1281 | ao_ref r1, r2; |
1282 | ao_ref_init (&r1, store1); | |
1283 | ao_ref_init (&r2, store2); | |
1284 | return refs_may_alias_p_1 (&r1, &r2, false); | |
2a3ebafa | 1285 | } |
dd277d48 | 1286 | |
1287 | /* If the call CALL may use the memory reference REF return true, | |
1288 | otherwise return false. */ | |
1289 | ||
1290 | static bool | |
134899ac | 1291 | ref_maybe_used_by_call_p_1 (gimple call, ao_ref *ref) |
dd277d48 | 1292 | { |
047fdd47 | 1293 | tree base, callee; |
dd277d48 | 1294 | unsigned i; |
1295 | int flags = gimple_call_flags (call); | |
1296 | ||
1297 | /* Const functions without a static chain do not implicitly use memory. */ | |
1298 | if (!gimple_call_chain (call) | |
1299 | && (flags & (ECF_CONST|ECF_NOVOPS))) | |
1300 | goto process_args; | |
1301 | ||
134899ac | 1302 | base = ao_ref_base (ref); |
917f08fa | 1303 | if (!base) |
dd277d48 | 1304 | return true; |
1305 | ||
3787db52 | 1306 | /* A call that is not without side-effects might involve volatile |
1307 | accesses and thus conflicts with all other volatile accesses. */ | |
1308 | if (ref->volatile_p) | |
1309 | return true; | |
1310 | ||
09347e88 | 1311 | /* If the reference is based on a decl that is not aliased the call |
1312 | cannot possibly use it. */ | |
1313 | if (DECL_P (base) | |
1314 | && !may_be_aliased (base) | |
7f7f16d4 | 1315 | /* But local statics can be used through recursion. */ |
1316 | && !is_global_var (base)) | |
09347e88 | 1317 | goto process_args; |
1318 | ||
047fdd47 | 1319 | callee = gimple_call_fndecl (call); |
1320 | ||
1321 | /* Handle those builtin functions explicitly that do not act as | |
1322 | escape points. See tree-ssa-structalias.c:find_func_aliases | |
1323 | for the list of builtins we might need to handle here. */ | |
1324 | if (callee != NULL_TREE | |
1325 | && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL) | |
1326 | switch (DECL_FUNCTION_CODE (callee)) | |
1327 | { | |
77efe819 | 1328 | /* All the following functions read memory pointed to by |
1329 | their second argument. strcat/strncat additionally | |
1330 | reads memory pointed to by the first argument. */ | |
1331 | case BUILT_IN_STRCAT: | |
1332 | case BUILT_IN_STRNCAT: | |
1333 | { | |
1334 | ao_ref dref; | |
1335 | ao_ref_init_from_ptr_and_size (&dref, | |
1336 | gimple_call_arg (call, 0), | |
1337 | NULL_TREE); | |
1338 | if (refs_may_alias_p_1 (&dref, ref, false)) | |
1339 | return true; | |
1340 | } | |
1341 | /* FALLTHRU */ | |
047fdd47 | 1342 | case BUILT_IN_STRCPY: |
1343 | case BUILT_IN_STRNCPY: | |
047fdd47 | 1344 | case BUILT_IN_MEMCPY: |
1345 | case BUILT_IN_MEMMOVE: | |
1346 | case BUILT_IN_MEMPCPY: | |
1347 | case BUILT_IN_STPCPY: | |
1348 | case BUILT_IN_STPNCPY: | |
4c0315d0 | 1349 | case BUILT_IN_TM_MEMCPY: |
1350 | case BUILT_IN_TM_MEMMOVE: | |
047fdd47 | 1351 | { |
134899ac | 1352 | ao_ref dref; |
1353 | tree size = NULL_TREE; | |
1354 | if (gimple_call_num_args (call) == 3) | |
1355 | size = gimple_call_arg (call, 2); | |
1356 | ao_ref_init_from_ptr_and_size (&dref, | |
1357 | gimple_call_arg (call, 1), | |
1358 | size); | |
1359 | return refs_may_alias_p_1 (&dref, ref, false); | |
047fdd47 | 1360 | } |
77efe819 | 1361 | case BUILT_IN_STRCAT_CHK: |
1362 | case BUILT_IN_STRNCAT_CHK: | |
1363 | { | |
1364 | ao_ref dref; | |
1365 | ao_ref_init_from_ptr_and_size (&dref, | |
1366 | gimple_call_arg (call, 0), | |
1367 | NULL_TREE); | |
1368 | if (refs_may_alias_p_1 (&dref, ref, false)) | |
1369 | return true; | |
1370 | } | |
1371 | /* FALLTHRU */ | |
939514e9 | 1372 | case BUILT_IN_STRCPY_CHK: |
1373 | case BUILT_IN_STRNCPY_CHK: | |
1374 | case BUILT_IN_MEMCPY_CHK: | |
1375 | case BUILT_IN_MEMMOVE_CHK: | |
1376 | case BUILT_IN_MEMPCPY_CHK: | |
1377 | case BUILT_IN_STPCPY_CHK: | |
1063acde | 1378 | case BUILT_IN_STPNCPY_CHK: |
939514e9 | 1379 | { |
1380 | ao_ref dref; | |
1381 | tree size = NULL_TREE; | |
1382 | if (gimple_call_num_args (call) == 4) | |
1383 | size = gimple_call_arg (call, 2); | |
1384 | ao_ref_init_from_ptr_and_size (&dref, | |
1385 | gimple_call_arg (call, 1), | |
1386 | size); | |
1387 | return refs_may_alias_p_1 (&dref, ref, false); | |
1388 | } | |
119147d1 | 1389 | case BUILT_IN_BCOPY: |
1390 | { | |
1391 | ao_ref dref; | |
1392 | tree size = gimple_call_arg (call, 2); | |
1393 | ao_ref_init_from_ptr_and_size (&dref, | |
1394 | gimple_call_arg (call, 0), | |
1395 | size); | |
1396 | return refs_may_alias_p_1 (&dref, ref, false); | |
1397 | } | |
4c0315d0 | 1398 | |
1399 | /* The following functions read memory pointed to by their | |
1400 | first argument. */ | |
1401 | CASE_BUILT_IN_TM_LOAD (1): | |
1402 | CASE_BUILT_IN_TM_LOAD (2): | |
1403 | CASE_BUILT_IN_TM_LOAD (4): | |
1404 | CASE_BUILT_IN_TM_LOAD (8): | |
1405 | CASE_BUILT_IN_TM_LOAD (FLOAT): | |
1406 | CASE_BUILT_IN_TM_LOAD (DOUBLE): | |
1407 | CASE_BUILT_IN_TM_LOAD (LDOUBLE): | |
1408 | CASE_BUILT_IN_TM_LOAD (M64): | |
1409 | CASE_BUILT_IN_TM_LOAD (M128): | |
1410 | CASE_BUILT_IN_TM_LOAD (M256): | |
1411 | case BUILT_IN_TM_LOG: | |
1412 | case BUILT_IN_TM_LOG_1: | |
1413 | case BUILT_IN_TM_LOG_2: | |
1414 | case BUILT_IN_TM_LOG_4: | |
1415 | case BUILT_IN_TM_LOG_8: | |
1416 | case BUILT_IN_TM_LOG_FLOAT: | |
1417 | case BUILT_IN_TM_LOG_DOUBLE: | |
1418 | case BUILT_IN_TM_LOG_LDOUBLE: | |
1419 | case BUILT_IN_TM_LOG_M64: | |
1420 | case BUILT_IN_TM_LOG_M128: | |
1421 | case BUILT_IN_TM_LOG_M256: | |
1422 | return ptr_deref_may_alias_ref_p_1 (gimple_call_arg (call, 0), ref); | |
1423 | ||
77efe819 | 1424 | /* These read memory pointed to by the first argument. */ |
1425 | case BUILT_IN_STRDUP: | |
1426 | case BUILT_IN_STRNDUP: | |
1427 | { | |
1428 | ao_ref dref; | |
1429 | tree size = NULL_TREE; | |
1430 | if (gimple_call_num_args (call) == 2) | |
1431 | size = gimple_call_arg (call, 1); | |
1432 | ao_ref_init_from_ptr_and_size (&dref, | |
1433 | gimple_call_arg (call, 0), | |
1434 | size); | |
1435 | return refs_may_alias_p_1 (&dref, ref, false); | |
1436 | } | |
4953672f | 1437 | /* These read memory pointed to by the first argument. */ |
1438 | case BUILT_IN_INDEX: | |
1439 | case BUILT_IN_STRCHR: | |
1440 | case BUILT_IN_STRRCHR: | |
1441 | { | |
1442 | ao_ref dref; | |
1443 | ao_ref_init_from_ptr_and_size (&dref, | |
1444 | gimple_call_arg (call, 0), | |
1445 | NULL_TREE); | |
1446 | return refs_may_alias_p_1 (&dref, ref, false); | |
1447 | } | |
1448 | /* These read memory pointed to by the first argument with size | |
1449 | in the third argument. */ | |
1450 | case BUILT_IN_MEMCHR: | |
1451 | { | |
1452 | ao_ref dref; | |
1453 | ao_ref_init_from_ptr_and_size (&dref, | |
1454 | gimple_call_arg (call, 0), | |
1455 | gimple_call_arg (call, 2)); | |
1456 | return refs_may_alias_p_1 (&dref, ref, false); | |
1457 | } | |
1458 | /* These read memory pointed to by the first and second arguments. */ | |
1459 | case BUILT_IN_STRSTR: | |
1460 | case BUILT_IN_STRPBRK: | |
1461 | { | |
1462 | ao_ref dref; | |
1463 | ao_ref_init_from_ptr_and_size (&dref, | |
1464 | gimple_call_arg (call, 0), | |
1465 | NULL_TREE); | |
1466 | if (refs_may_alias_p_1 (&dref, ref, false)) | |
1467 | return true; | |
1468 | ao_ref_init_from_ptr_and_size (&dref, | |
1469 | gimple_call_arg (call, 1), | |
1470 | NULL_TREE); | |
1471 | return refs_may_alias_p_1 (&dref, ref, false); | |
1472 | } | |
1473 | ||
09d9c774 | 1474 | /* The following builtins do not read from memory. */ |
1475 | case BUILT_IN_FREE: | |
0d3ca08e | 1476 | case BUILT_IN_MALLOC: |
4ef43bbd | 1477 | case BUILT_IN_CALLOC: |
ca793672 | 1478 | case BUILT_IN_ALLOCA: |
581bf1c2 | 1479 | case BUILT_IN_ALLOCA_WITH_ALIGN: |
ca793672 | 1480 | case BUILT_IN_STACK_SAVE: |
1481 | case BUILT_IN_STACK_RESTORE: | |
09d9c774 | 1482 | case BUILT_IN_MEMSET: |
4c0315d0 | 1483 | case BUILT_IN_TM_MEMSET: |
939514e9 | 1484 | case BUILT_IN_MEMSET_CHK: |
09d9c774 | 1485 | case BUILT_IN_FREXP: |
1486 | case BUILT_IN_FREXPF: | |
1487 | case BUILT_IN_FREXPL: | |
1488 | case BUILT_IN_GAMMA_R: | |
1489 | case BUILT_IN_GAMMAF_R: | |
1490 | case BUILT_IN_GAMMAL_R: | |
1491 | case BUILT_IN_LGAMMA_R: | |
1492 | case BUILT_IN_LGAMMAF_R: | |
1493 | case BUILT_IN_LGAMMAL_R: | |
1494 | case BUILT_IN_MODF: | |
1495 | case BUILT_IN_MODFF: | |
1496 | case BUILT_IN_MODFL: | |
1497 | case BUILT_IN_REMQUO: | |
1498 | case BUILT_IN_REMQUOF: | |
1499 | case BUILT_IN_REMQUOL: | |
1500 | case BUILT_IN_SINCOS: | |
1501 | case BUILT_IN_SINCOSF: | |
1502 | case BUILT_IN_SINCOSL: | |
fca0886c | 1503 | case BUILT_IN_ASSUME_ALIGNED: |
9d17b4a8 | 1504 | case BUILT_IN_VA_END: |
09d9c774 | 1505 | return false; |
a44814b9 | 1506 | /* __sync_* builtins and some OpenMP builtins act as threading |
1507 | barriers. */ | |
1508 | #undef DEF_SYNC_BUILTIN | |
1509 | #define DEF_SYNC_BUILTIN(ENUM, NAME, TYPE, ATTRS) case ENUM: | |
1510 | #include "sync-builtins.def" | |
1511 | #undef DEF_SYNC_BUILTIN | |
1512 | case BUILT_IN_GOMP_ATOMIC_START: | |
1513 | case BUILT_IN_GOMP_ATOMIC_END: | |
1514 | case BUILT_IN_GOMP_BARRIER: | |
1515 | case BUILT_IN_GOMP_TASKWAIT: | |
1516 | case BUILT_IN_GOMP_CRITICAL_START: | |
1517 | case BUILT_IN_GOMP_CRITICAL_END: | |
1518 | case BUILT_IN_GOMP_CRITICAL_NAME_START: | |
1519 | case BUILT_IN_GOMP_CRITICAL_NAME_END: | |
1520 | case BUILT_IN_GOMP_LOOP_END: | |
1521 | case BUILT_IN_GOMP_ORDERED_START: | |
1522 | case BUILT_IN_GOMP_ORDERED_END: | |
1523 | case BUILT_IN_GOMP_PARALLEL_END: | |
1524 | case BUILT_IN_GOMP_SECTIONS_END: | |
1525 | case BUILT_IN_GOMP_SINGLE_COPY_START: | |
1526 | case BUILT_IN_GOMP_SINGLE_COPY_END: | |
1527 | return true; | |
09d9c774 | 1528 | |
047fdd47 | 1529 | default: |
1530 | /* Fallthru to general call handling. */; | |
1531 | } | |
1532 | ||
dd277d48 | 1533 | /* Check if base is a global static variable that is not read |
1534 | by the function. */ | |
924de091 | 1535 | if (callee != NULL_TREE |
1536 | && TREE_CODE (base) == VAR_DECL | |
d97be713 | 1537 | && TREE_STATIC (base)) |
4ee9c684 | 1538 | { |
924de091 | 1539 | struct cgraph_node *node = cgraph_get_node (callee); |
dd277d48 | 1540 | bitmap not_read; |
1541 | ||
924de091 | 1542 | /* FIXME: Callee can be an OMP builtin that does not have a call graph |
1543 | node yet. We should enforce that there are nodes for all decls in the | |
1544 | IL and remove this check instead. */ | |
1545 | if (node | |
1546 | && (not_read = ipa_reference_get_not_read_global (node)) | |
dd277d48 | 1547 | && bitmap_bit_p (not_read, DECL_UID (base))) |
1548 | goto process_args; | |
4ee9c684 | 1549 | } |
1550 | ||
cb245216 | 1551 | /* Check if the base variable is call-used. */ |
1552 | if (DECL_P (base)) | |
4ee9c684 | 1553 | { |
cb245216 | 1554 | if (pt_solution_includes (gimple_call_use_set (call), base)) |
dd277d48 | 1555 | return true; |
1556 | } | |
2622064f | 1557 | else if ((TREE_CODE (base) == MEM_REF |
1558 | || TREE_CODE (base) == TARGET_MEM_REF) | |
cb245216 | 1559 | && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME) |
dd277d48 | 1560 | { |
cb245216 | 1561 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0)); |
1562 | if (!pi) | |
1563 | return true; | |
917f08fa | 1564 | |
cb245216 | 1565 | if (pt_solutions_intersect (gimple_call_use_set (call), &pi->pt)) |
dd277d48 | 1566 | return true; |
1567 | } | |
cb245216 | 1568 | else |
1569 | return true; | |
dd277d48 | 1570 | |
1571 | /* Inspect call arguments for passed-by-value aliases. */ | |
1572 | process_args: | |
1573 | for (i = 0; i < gimple_call_num_args (call); ++i) | |
1574 | { | |
1575 | tree op = gimple_call_arg (call, i); | |
8ce86007 | 1576 | int flags = gimple_call_arg_flags (call, i); |
1577 | ||
1578 | if (flags & EAF_UNUSED) | |
1579 | continue; | |
dd277d48 | 1580 | |
dd277d48 | 1581 | if (TREE_CODE (op) == WITH_SIZE_EXPR) |
1582 | op = TREE_OPERAND (op, 0); | |
4ee9c684 | 1583 | |
dd277d48 | 1584 | if (TREE_CODE (op) != SSA_NAME |
134899ac | 1585 | && !is_gimple_min_invariant (op)) |
1586 | { | |
1587 | ao_ref r; | |
1588 | ao_ref_init (&r, op); | |
1589 | if (refs_may_alias_p_1 (&r, ref, true)) | |
1590 | return true; | |
1591 | } | |
4ee9c684 | 1592 | } |
1593 | ||
dd277d48 | 1594 | return false; |
1595 | } | |
1596 | ||
1597 | static bool | |
1598 | ref_maybe_used_by_call_p (gimple call, tree ref) | |
1599 | { | |
134899ac | 1600 | ao_ref r; |
1601 | bool res; | |
1602 | ao_ref_init (&r, ref); | |
1603 | res = ref_maybe_used_by_call_p_1 (call, &r); | |
dd277d48 | 1604 | if (res) |
1605 | ++alias_stats.ref_maybe_used_by_call_p_may_alias; | |
1606 | else | |
1607 | ++alias_stats.ref_maybe_used_by_call_p_no_alias; | |
1608 | return res; | |
4ee9c684 | 1609 | } |
1610 | ||
1611 | ||
dd277d48 | 1612 | /* If the statement STMT may use the memory reference REF return |
1613 | true, otherwise return false. */ | |
4ee9c684 | 1614 | |
dd277d48 | 1615 | bool |
1616 | ref_maybe_used_by_stmt_p (gimple stmt, tree ref) | |
4ee9c684 | 1617 | { |
dd277d48 | 1618 | if (is_gimple_assign (stmt)) |
1619 | { | |
1620 | tree rhs; | |
1621 | ||
1622 | /* All memory assign statements are single. */ | |
1623 | if (!gimple_assign_single_p (stmt)) | |
1624 | return false; | |
1625 | ||
1626 | rhs = gimple_assign_rhs1 (stmt); | |
1627 | if (is_gimple_reg (rhs) | |
1628 | || is_gimple_min_invariant (rhs) | |
1629 | || gimple_assign_rhs_code (stmt) == CONSTRUCTOR) | |
1630 | return false; | |
1631 | ||
1632 | return refs_may_alias_p (rhs, ref); | |
1633 | } | |
1634 | else if (is_gimple_call (stmt)) | |
1635 | return ref_maybe_used_by_call_p (stmt, ref); | |
91234829 | 1636 | else if (gimple_code (stmt) == GIMPLE_RETURN) |
1637 | { | |
1638 | tree retval = gimple_return_retval (stmt); | |
1639 | tree base; | |
1640 | if (retval | |
1641 | && TREE_CODE (retval) != SSA_NAME | |
1642 | && !is_gimple_min_invariant (retval) | |
1643 | && refs_may_alias_p (retval, ref)) | |
1644 | return true; | |
1645 | /* If ref escapes the function then the return acts as a use. */ | |
1646 | base = get_base_address (ref); | |
1647 | if (!base) | |
1648 | ; | |
1649 | else if (DECL_P (base)) | |
1650 | return is_global_var (base); | |
1651 | else if (TREE_CODE (base) == MEM_REF | |
1652 | || TREE_CODE (base) == TARGET_MEM_REF) | |
1653 | return ptr_deref_may_alias_global_p (TREE_OPERAND (base, 0)); | |
1654 | return false; | |
1655 | } | |
dd277d48 | 1656 | |
1657 | return true; | |
4ee9c684 | 1658 | } |
1659 | ||
dd277d48 | 1660 | /* If the call in statement CALL may clobber the memory reference REF |
1661 | return true, otherwise return false. */ | |
4ee9c684 | 1662 | |
dd277d48 | 1663 | static bool |
3918bd18 | 1664 | call_may_clobber_ref_p_1 (gimple call, ao_ref *ref) |
4ee9c684 | 1665 | { |
7f7f16d4 | 1666 | tree base; |
047fdd47 | 1667 | tree callee; |
dd277d48 | 1668 | |
1669 | /* If the call is pure or const it cannot clobber anything. */ | |
1670 | if (gimple_call_flags (call) | |
1671 | & (ECF_PURE|ECF_CONST|ECF_LOOPING_CONST_OR_PURE|ECF_NOVOPS)) | |
1672 | return false; | |
1673 | ||
3918bd18 | 1674 | base = ao_ref_base (ref); |
dd277d48 | 1675 | if (!base) |
1676 | return true; | |
1677 | ||
1678 | if (TREE_CODE (base) == SSA_NAME | |
1679 | || CONSTANT_CLASS_P (base)) | |
1680 | return false; | |
1681 | ||
3787db52 | 1682 | /* A call that is not without side-effects might involve volatile |
1683 | accesses and thus conflicts with all other volatile accesses. */ | |
1684 | if (ref->volatile_p) | |
1685 | return true; | |
1686 | ||
09347e88 | 1687 | /* If the reference is based on a decl that is not aliased the call |
1688 | cannot possibly clobber it. */ | |
1689 | if (DECL_P (base) | |
1690 | && !may_be_aliased (base) | |
7f7f16d4 | 1691 | /* But local non-readonly statics can be modified through recursion |
1692 | or the call may implement a threading barrier which we must | |
1693 | treat as may-def. */ | |
09347e88 | 1694 | && (TREE_READONLY (base) |
7f7f16d4 | 1695 | || !is_global_var (base))) |
09347e88 | 1696 | return false; |
1697 | ||
047fdd47 | 1698 | callee = gimple_call_fndecl (call); |
1699 | ||
1700 | /* Handle those builtin functions explicitly that do not act as | |
1701 | escape points. See tree-ssa-structalias.c:find_func_aliases | |
1702 | for the list of builtins we might need to handle here. */ | |
1703 | if (callee != NULL_TREE | |
1704 | && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL) | |
1705 | switch (DECL_FUNCTION_CODE (callee)) | |
1706 | { | |
1707 | /* All the following functions clobber memory pointed to by | |
1708 | their first argument. */ | |
1709 | case BUILT_IN_STRCPY: | |
1710 | case BUILT_IN_STRNCPY: | |
047fdd47 | 1711 | case BUILT_IN_MEMCPY: |
1712 | case BUILT_IN_MEMMOVE: | |
1713 | case BUILT_IN_MEMPCPY: | |
1714 | case BUILT_IN_STPCPY: | |
1715 | case BUILT_IN_STPNCPY: | |
1716 | case BUILT_IN_STRCAT: | |
1717 | case BUILT_IN_STRNCAT: | |
134899ac | 1718 | case BUILT_IN_MEMSET: |
4c0315d0 | 1719 | case BUILT_IN_TM_MEMSET: |
1720 | CASE_BUILT_IN_TM_STORE (1): | |
1721 | CASE_BUILT_IN_TM_STORE (2): | |
1722 | CASE_BUILT_IN_TM_STORE (4): | |
1723 | CASE_BUILT_IN_TM_STORE (8): | |
1724 | CASE_BUILT_IN_TM_STORE (FLOAT): | |
1725 | CASE_BUILT_IN_TM_STORE (DOUBLE): | |
1726 | CASE_BUILT_IN_TM_STORE (LDOUBLE): | |
1727 | CASE_BUILT_IN_TM_STORE (M64): | |
1728 | CASE_BUILT_IN_TM_STORE (M128): | |
1729 | CASE_BUILT_IN_TM_STORE (M256): | |
1730 | case BUILT_IN_TM_MEMCPY: | |
1731 | case BUILT_IN_TM_MEMMOVE: | |
047fdd47 | 1732 | { |
134899ac | 1733 | ao_ref dref; |
1734 | tree size = NULL_TREE; | |
77efe819 | 1735 | /* Don't pass in size for strncat, as the maximum size |
1736 | is strlen (dest) + n + 1 instead of n, resp. | |
1737 | n + 1 at dest + strlen (dest), but strlen (dest) isn't | |
1738 | known. */ | |
1739 | if (gimple_call_num_args (call) == 3 | |
1740 | && DECL_FUNCTION_CODE (callee) != BUILT_IN_STRNCAT) | |
134899ac | 1741 | size = gimple_call_arg (call, 2); |
1742 | ao_ref_init_from_ptr_and_size (&dref, | |
1743 | gimple_call_arg (call, 0), | |
1744 | size); | |
1745 | return refs_may_alias_p_1 (&dref, ref, false); | |
047fdd47 | 1746 | } |
939514e9 | 1747 | case BUILT_IN_STRCPY_CHK: |
1748 | case BUILT_IN_STRNCPY_CHK: | |
1749 | case BUILT_IN_MEMCPY_CHK: | |
1750 | case BUILT_IN_MEMMOVE_CHK: | |
1751 | case BUILT_IN_MEMPCPY_CHK: | |
1752 | case BUILT_IN_STPCPY_CHK: | |
1063acde | 1753 | case BUILT_IN_STPNCPY_CHK: |
939514e9 | 1754 | case BUILT_IN_STRCAT_CHK: |
1755 | case BUILT_IN_STRNCAT_CHK: | |
1756 | case BUILT_IN_MEMSET_CHK: | |
1757 | { | |
1758 | ao_ref dref; | |
1759 | tree size = NULL_TREE; | |
77efe819 | 1760 | /* Don't pass in size for __strncat_chk, as the maximum size |
1761 | is strlen (dest) + n + 1 instead of n, resp. | |
1762 | n + 1 at dest + strlen (dest), but strlen (dest) isn't | |
1763 | known. */ | |
1764 | if (gimple_call_num_args (call) == 4 | |
1765 | && DECL_FUNCTION_CODE (callee) != BUILT_IN_STRNCAT_CHK) | |
939514e9 | 1766 | size = gimple_call_arg (call, 2); |
1767 | ao_ref_init_from_ptr_and_size (&dref, | |
1768 | gimple_call_arg (call, 0), | |
1769 | size); | |
1770 | return refs_may_alias_p_1 (&dref, ref, false); | |
1771 | } | |
119147d1 | 1772 | case BUILT_IN_BCOPY: |
1773 | { | |
1774 | ao_ref dref; | |
1775 | tree size = gimple_call_arg (call, 2); | |
1776 | ao_ref_init_from_ptr_and_size (&dref, | |
1777 | gimple_call_arg (call, 1), | |
1778 | size); | |
1779 | return refs_may_alias_p_1 (&dref, ref, false); | |
1780 | } | |
0d3ca08e | 1781 | /* Allocating memory does not have any side-effects apart from |
1782 | being the definition point for the pointer. */ | |
1783 | case BUILT_IN_MALLOC: | |
4ef43bbd | 1784 | case BUILT_IN_CALLOC: |
77efe819 | 1785 | case BUILT_IN_STRDUP: |
1786 | case BUILT_IN_STRNDUP: | |
be97d4b6 | 1787 | /* Unix98 specifies that errno is set on allocation failure. */ |
a29c5f9c | 1788 | if (flag_errno_math |
be97d4b6 | 1789 | && targetm.ref_may_alias_errno (ref)) |
1790 | return true; | |
0d3ca08e | 1791 | return false; |
ca793672 | 1792 | case BUILT_IN_STACK_SAVE: |
1793 | case BUILT_IN_ALLOCA: | |
581bf1c2 | 1794 | case BUILT_IN_ALLOCA_WITH_ALIGN: |
fca0886c | 1795 | case BUILT_IN_ASSUME_ALIGNED: |
ca793672 | 1796 | return false; |
047fdd47 | 1797 | /* Freeing memory kills the pointed-to memory. More importantly |
1798 | the call has to serve as a barrier for moving loads and stores | |
134899ac | 1799 | across it. */ |
047fdd47 | 1800 | case BUILT_IN_FREE: |
9d17b4a8 | 1801 | case BUILT_IN_VA_END: |
047fdd47 | 1802 | { |
1803 | tree ptr = gimple_call_arg (call, 0); | |
1804 | return ptr_deref_may_alias_ref_p_1 (ptr, ref); | |
1805 | } | |
047fdd47 | 1806 | case BUILT_IN_GAMMA_R: |
1807 | case BUILT_IN_GAMMAF_R: | |
1808 | case BUILT_IN_GAMMAL_R: | |
1809 | case BUILT_IN_LGAMMA_R: | |
1810 | case BUILT_IN_LGAMMAF_R: | |
1811 | case BUILT_IN_LGAMMAL_R: | |
09d9c774 | 1812 | { |
1813 | tree out = gimple_call_arg (call, 1); | |
1814 | if (ptr_deref_may_alias_ref_p_1 (out, ref)) | |
1815 | return true; | |
1816 | if (flag_errno_math) | |
1817 | break; | |
1818 | return false; | |
1819 | } | |
1820 | case BUILT_IN_FREXP: | |
1821 | case BUILT_IN_FREXPF: | |
1822 | case BUILT_IN_FREXPL: | |
047fdd47 | 1823 | case BUILT_IN_MODF: |
1824 | case BUILT_IN_MODFF: | |
1825 | case BUILT_IN_MODFL: | |
1826 | { | |
1827 | tree out = gimple_call_arg (call, 1); | |
1828 | return ptr_deref_may_alias_ref_p_1 (out, ref); | |
1829 | } | |
1830 | case BUILT_IN_REMQUO: | |
1831 | case BUILT_IN_REMQUOF: | |
1832 | case BUILT_IN_REMQUOL: | |
1833 | { | |
1834 | tree out = gimple_call_arg (call, 2); | |
09d9c774 | 1835 | if (ptr_deref_may_alias_ref_p_1 (out, ref)) |
1836 | return true; | |
1837 | if (flag_errno_math) | |
1838 | break; | |
1839 | return false; | |
047fdd47 | 1840 | } |
1841 | case BUILT_IN_SINCOS: | |
1842 | case BUILT_IN_SINCOSF: | |
1843 | case BUILT_IN_SINCOSL: | |
1844 | { | |
1845 | tree sin = gimple_call_arg (call, 1); | |
1846 | tree cos = gimple_call_arg (call, 2); | |
1847 | return (ptr_deref_may_alias_ref_p_1 (sin, ref) | |
1848 | || ptr_deref_may_alias_ref_p_1 (cos, ref)); | |
1849 | } | |
a44814b9 | 1850 | /* __sync_* builtins and some OpenMP builtins act as threading |
1851 | barriers. */ | |
1852 | #undef DEF_SYNC_BUILTIN | |
1853 | #define DEF_SYNC_BUILTIN(ENUM, NAME, TYPE, ATTRS) case ENUM: | |
1854 | #include "sync-builtins.def" | |
1855 | #undef DEF_SYNC_BUILTIN | |
1856 | case BUILT_IN_GOMP_ATOMIC_START: | |
1857 | case BUILT_IN_GOMP_ATOMIC_END: | |
1858 | case BUILT_IN_GOMP_BARRIER: | |
1859 | case BUILT_IN_GOMP_TASKWAIT: | |
1860 | case BUILT_IN_GOMP_CRITICAL_START: | |
1861 | case BUILT_IN_GOMP_CRITICAL_END: | |
1862 | case BUILT_IN_GOMP_CRITICAL_NAME_START: | |
1863 | case BUILT_IN_GOMP_CRITICAL_NAME_END: | |
1864 | case BUILT_IN_GOMP_LOOP_END: | |
1865 | case BUILT_IN_GOMP_ORDERED_START: | |
1866 | case BUILT_IN_GOMP_ORDERED_END: | |
1867 | case BUILT_IN_GOMP_PARALLEL_END: | |
1868 | case BUILT_IN_GOMP_SECTIONS_END: | |
1869 | case BUILT_IN_GOMP_SINGLE_COPY_START: | |
1870 | case BUILT_IN_GOMP_SINGLE_COPY_END: | |
1871 | return true; | |
047fdd47 | 1872 | default: |
1873 | /* Fallthru to general call handling. */; | |
1874 | } | |
1875 | ||
dd277d48 | 1876 | /* Check if base is a global static variable that is not written |
1877 | by the function. */ | |
047fdd47 | 1878 | if (callee != NULL_TREE |
1879 | && TREE_CODE (base) == VAR_DECL | |
d97be713 | 1880 | && TREE_STATIC (base)) |
4ee9c684 | 1881 | { |
924de091 | 1882 | struct cgraph_node *node = cgraph_get_node (callee); |
dd277d48 | 1883 | bitmap not_written; |
0eaf9bd7 | 1884 | |
924de091 | 1885 | if (node |
1886 | && (not_written = ipa_reference_get_not_written_global (node)) | |
dd277d48 | 1887 | && bitmap_bit_p (not_written, DECL_UID (base))) |
1888 | return false; | |
4ee9c684 | 1889 | } |
4ee9c684 | 1890 | |
cb245216 | 1891 | /* Check if the base variable is call-clobbered. */ |
dd277d48 | 1892 | if (DECL_P (base)) |
cb245216 | 1893 | return pt_solution_includes (gimple_call_clobber_set (call), base); |
2622064f | 1894 | else if ((TREE_CODE (base) == MEM_REF |
1895 | || TREE_CODE (base) == TARGET_MEM_REF) | |
917f08fa | 1896 | && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME) |
1897 | { | |
1898 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0)); | |
1899 | if (!pi) | |
1900 | return true; | |
1901 | ||
cb245216 | 1902 | return pt_solutions_intersect (gimple_call_clobber_set (call), &pi->pt); |
917f08fa | 1903 | } |
4ee9c684 | 1904 | |
dd277d48 | 1905 | return true; |
1906 | } | |
4ee9c684 | 1907 | |
4debfcfc | 1908 | /* If the call in statement CALL may clobber the memory reference REF |
1909 | return true, otherwise return false. */ | |
1910 | ||
1911 | bool | |
dd277d48 | 1912 | call_may_clobber_ref_p (gimple call, tree ref) |
4ee9c684 | 1913 | { |
3918bd18 | 1914 | bool res; |
1915 | ao_ref r; | |
1916 | ao_ref_init (&r, ref); | |
1917 | res = call_may_clobber_ref_p_1 (call, &r); | |
dd277d48 | 1918 | if (res) |
1919 | ++alias_stats.call_may_clobber_ref_p_may_alias; | |
1920 | else | |
1921 | ++alias_stats.call_may_clobber_ref_p_no_alias; | |
1922 | return res; | |
4ee9c684 | 1923 | } |
94e6573f | 1924 | |
dd277d48 | 1925 | |
1926 | /* If the statement STMT may clobber the memory reference REF return true, | |
1927 | otherwise return false. */ | |
94e6573f | 1928 | |
1929 | bool | |
3918bd18 | 1930 | stmt_may_clobber_ref_p_1 (gimple stmt, ao_ref *ref) |
94e6573f | 1931 | { |
dd277d48 | 1932 | if (is_gimple_call (stmt)) |
1933 | { | |
1934 | tree lhs = gimple_call_lhs (stmt); | |
1935 | if (lhs | |
66b86a74 | 1936 | && TREE_CODE (lhs) != SSA_NAME) |
3918bd18 | 1937 | { |
1938 | ao_ref r; | |
1939 | ao_ref_init (&r, lhs); | |
1940 | if (refs_may_alias_p_1 (ref, &r, true)) | |
1941 | return true; | |
1942 | } | |
94e6573f | 1943 | |
3918bd18 | 1944 | return call_may_clobber_ref_p_1 (stmt, ref); |
dd277d48 | 1945 | } |
8e7c2b9c | 1946 | else if (gimple_assign_single_p (stmt)) |
3918bd18 | 1947 | { |
8e7c2b9c | 1948 | tree lhs = gimple_assign_lhs (stmt); |
66b86a74 | 1949 | if (TREE_CODE (lhs) != SSA_NAME) |
8e7c2b9c | 1950 | { |
1951 | ao_ref r; | |
66b86a74 | 1952 | ao_ref_init (&r, lhs); |
8e7c2b9c | 1953 | return refs_may_alias_p_1 (ref, &r, true); |
1954 | } | |
3918bd18 | 1955 | } |
dd277d48 | 1956 | else if (gimple_code (stmt) == GIMPLE_ASM) |
94e6573f | 1957 | return true; |
1958 | ||
6329636b | 1959 | return false; |
94e6573f | 1960 | } |
2be14d8b | 1961 | |
3918bd18 | 1962 | bool |
1963 | stmt_may_clobber_ref_p (gimple stmt, tree ref) | |
1964 | { | |
1965 | ao_ref r; | |
1966 | ao_ref_init (&r, ref); | |
1967 | return stmt_may_clobber_ref_p_1 (stmt, &r); | |
1968 | } | |
1969 | ||
ab450cc6 | 1970 | /* If STMT kills the memory reference REF return true, otherwise |
1971 | return false. */ | |
1972 | ||
1973 | static bool | |
1974 | stmt_kills_ref_p_1 (gimple stmt, ao_ref *ref) | |
1975 | { | |
07ff6a65 | 1976 | /* For a must-alias check we need to be able to constrain |
1977 | the access properly. */ | |
1978 | ao_ref_base (ref); | |
1979 | if (ref->max_size == -1) | |
1980 | return false; | |
1981 | ||
ab450cc6 | 1982 | if (gimple_has_lhs (stmt) |
e54d36c4 | 1983 | && TREE_CODE (gimple_get_lhs (stmt)) != SSA_NAME |
1984 | /* The assignment is not necessarily carried out if it can throw | |
1985 | and we can catch it in the current function where we could inspect | |
1986 | the previous value. | |
1987 | ??? We only need to care about the RHS throwing. For aggregate | |
1988 | assignments or similar calls and non-call exceptions the LHS | |
1989 | might throw as well. */ | |
1990 | && !stmt_can_throw_internal (stmt)) | |
ab450cc6 | 1991 | { |
1992 | tree base, lhs = gimple_get_lhs (stmt); | |
137eddca | 1993 | HOST_WIDE_INT size, offset, max_size, ref_offset = ref->offset; |
ab450cc6 | 1994 | base = get_ref_base_and_extent (lhs, &offset, &size, &max_size); |
1995 | /* We can get MEM[symbol: sZ, index: D.8862_1] here, | |
1996 | so base == ref->base does not always hold. */ | |
137eddca | 1997 | if (base != ref->base) |
ab450cc6 | 1998 | { |
137eddca | 1999 | /* If both base and ref->base are MEM_REFs, only compare the |
2000 | first operand, and if the second operand isn't equal constant, | |
2001 | try to add the offsets into offset and ref_offset. */ | |
2002 | if (TREE_CODE (base) == MEM_REF && TREE_CODE (ref->base) == MEM_REF | |
2003 | && TREE_OPERAND (base, 0) == TREE_OPERAND (ref->base, 0)) | |
ab450cc6 | 2004 | { |
83d18d6d | 2005 | if (!tree_int_cst_equal (TREE_OPERAND (base, 1), |
2006 | TREE_OPERAND (ref->base, 1))) | |
137eddca | 2007 | { |
2008 | double_int off1 = mem_ref_offset (base); | |
9a8b9e26 | 2009 | off1 = off1.lshift (BITS_PER_UNIT == 8 |
2010 | ? 3 : exact_log2 (BITS_PER_UNIT)); | |
137eddca | 2011 | off1 = off1 + double_int::from_shwi (offset); |
2012 | double_int off2 = mem_ref_offset (ref->base); | |
9a8b9e26 | 2013 | off2 = off2.lshift (BITS_PER_UNIT == 8 |
2014 | ? 3 : exact_log2 (BITS_PER_UNIT)); | |
137eddca | 2015 | off2 = off2 + double_int::from_shwi (ref_offset); |
2016 | if (off1.fits_shwi () && off2.fits_shwi ()) | |
2017 | { | |
2018 | offset = off1.to_shwi (); | |
2019 | ref_offset = off2.to_shwi (); | |
2020 | } | |
2021 | else | |
2022 | size = -1; | |
2023 | } | |
ab450cc6 | 2024 | } |
137eddca | 2025 | else |
2026 | size = -1; | |
2027 | } | |
2028 | /* For a must-alias check we need to be able to constrain | |
2029 | the access properly. */ | |
2030 | if (size != -1 && size == max_size) | |
2031 | { | |
2032 | if (offset <= ref_offset | |
2033 | && offset + size >= ref_offset + ref->max_size) | |
2034 | return true; | |
ab450cc6 | 2035 | } |
2036 | } | |
07ff6a65 | 2037 | |
2038 | if (is_gimple_call (stmt)) | |
2039 | { | |
2040 | tree callee = gimple_call_fndecl (stmt); | |
2041 | if (callee != NULL_TREE | |
2042 | && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL) | |
2043 | switch (DECL_FUNCTION_CODE (callee)) | |
2044 | { | |
2045 | case BUILT_IN_MEMCPY: | |
2046 | case BUILT_IN_MEMPCPY: | |
2047 | case BUILT_IN_MEMMOVE: | |
2048 | case BUILT_IN_MEMSET: | |
939514e9 | 2049 | case BUILT_IN_MEMCPY_CHK: |
2050 | case BUILT_IN_MEMPCPY_CHK: | |
2051 | case BUILT_IN_MEMMOVE_CHK: | |
2052 | case BUILT_IN_MEMSET_CHK: | |
07ff6a65 | 2053 | { |
2054 | tree dest = gimple_call_arg (stmt, 0); | |
2055 | tree len = gimple_call_arg (stmt, 2); | |
2056 | tree base = NULL_TREE; | |
2057 | HOST_WIDE_INT offset = 0; | |
2058 | if (!host_integerp (len, 0)) | |
2059 | return false; | |
2060 | if (TREE_CODE (dest) == ADDR_EXPR) | |
2061 | base = get_addr_base_and_unit_offset (TREE_OPERAND (dest, 0), | |
2062 | &offset); | |
2063 | else if (TREE_CODE (dest) == SSA_NAME) | |
2064 | base = dest; | |
2065 | if (base | |
2066 | && base == ao_ref_base (ref)) | |
2067 | { | |
2068 | HOST_WIDE_INT size = TREE_INT_CST_LOW (len); | |
2069 | if (offset <= ref->offset / BITS_PER_UNIT | |
2070 | && (offset + size | |
2071 | >= ((ref->offset + ref->max_size + BITS_PER_UNIT - 1) | |
2072 | / BITS_PER_UNIT))) | |
2073 | return true; | |
2074 | } | |
9d17b4a8 | 2075 | break; |
2076 | } | |
2077 | ||
2078 | case BUILT_IN_VA_END: | |
2079 | { | |
2080 | tree ptr = gimple_call_arg (stmt, 0); | |
2081 | if (TREE_CODE (ptr) == ADDR_EXPR) | |
2082 | { | |
2083 | tree base = ao_ref_base (ref); | |
2084 | if (TREE_OPERAND (ptr, 0) == base) | |
2085 | return true; | |
2086 | } | |
2087 | break; | |
07ff6a65 | 2088 | } |
9d17b4a8 | 2089 | |
07ff6a65 | 2090 | default:; |
2091 | } | |
07ff6a65 | 2092 | } |
ab450cc6 | 2093 | return false; |
2094 | } | |
2095 | ||
2096 | bool | |
2097 | stmt_kills_ref_p (gimple stmt, tree ref) | |
2098 | { | |
2099 | ao_ref r; | |
2100 | ao_ref_init (&r, ref); | |
2101 | return stmt_kills_ref_p_1 (stmt, &r); | |
2102 | } | |
2103 | ||
3918bd18 | 2104 | |
dd277d48 | 2105 | /* Walk the virtual use-def chain of VUSE until hitting the virtual operand |
2106 | TARGET or a statement clobbering the memory reference REF in which | |
2107 | case false is returned. The walk starts with VUSE, one argument of PHI. */ | |
2108 | ||
2109 | static bool | |
3918bd18 | 2110 | maybe_skip_until (gimple phi, tree target, ao_ref *ref, |
4fd7a6de | 2111 | tree vuse, unsigned int *cnt, bitmap *visited, |
2112 | bool abort_on_visited) | |
ac926412 | 2113 | { |
0afe880d | 2114 | basic_block bb = gimple_bb (phi); |
2115 | ||
dd277d48 | 2116 | if (!*visited) |
2117 | *visited = BITMAP_ALLOC (NULL); | |
ac926412 | 2118 | |
dd277d48 | 2119 | bitmap_set_bit (*visited, SSA_NAME_VERSION (PHI_RESULT (phi))); |
2120 | ||
2121 | /* Walk until we hit the target. */ | |
2122 | while (vuse != target) | |
ac926412 | 2123 | { |
dd277d48 | 2124 | gimple def_stmt = SSA_NAME_DEF_STMT (vuse); |
2125 | /* Recurse for PHI nodes. */ | |
2126 | if (gimple_code (def_stmt) == GIMPLE_PHI) | |
2127 | { | |
2128 | /* An already visited PHI node ends the walk successfully. */ | |
2129 | if (bitmap_bit_p (*visited, SSA_NAME_VERSION (PHI_RESULT (def_stmt)))) | |
4fd7a6de | 2130 | return !abort_on_visited; |
2131 | vuse = get_continuation_for_phi (def_stmt, ref, cnt, | |
2132 | visited, abort_on_visited); | |
dd277d48 | 2133 | if (!vuse) |
2134 | return false; | |
2135 | continue; | |
2136 | } | |
297a2110 | 2137 | else if (gimple_nop_p (def_stmt)) |
dd277d48 | 2138 | return false; |
297a2110 | 2139 | else |
2140 | { | |
2141 | /* A clobbering statement or the end of the IL ends it failing. */ | |
2142 | ++*cnt; | |
2143 | if (stmt_may_clobber_ref_p_1 (def_stmt, ref)) | |
2144 | return false; | |
2145 | } | |
0afe880d | 2146 | /* If we reach a new basic-block see if we already skipped it |
2147 | in a previous walk that ended successfully. */ | |
2148 | if (gimple_bb (def_stmt) != bb) | |
2149 | { | |
2150 | if (!bitmap_set_bit (*visited, SSA_NAME_VERSION (vuse))) | |
4fd7a6de | 2151 | return !abort_on_visited; |
0afe880d | 2152 | bb = gimple_bb (def_stmt); |
2153 | } | |
dd277d48 | 2154 | vuse = gimple_vuse (def_stmt); |
ac926412 | 2155 | } |
dd277d48 | 2156 | return true; |
2157 | } | |
ac926412 | 2158 | |
d7f69727 | 2159 | /* For two PHI arguments ARG0 and ARG1 try to skip non-aliasing code |
2160 | until we hit the phi argument definition that dominates the other one. | |
2161 | Return that, or NULL_TREE if there is no such definition. */ | |
2162 | ||
2163 | static tree | |
2164 | get_continuation_for_phi_1 (gimple phi, tree arg0, tree arg1, | |
4fd7a6de | 2165 | ao_ref *ref, unsigned int *cnt, |
2166 | bitmap *visited, bool abort_on_visited) | |
d7f69727 | 2167 | { |
2168 | gimple def0 = SSA_NAME_DEF_STMT (arg0); | |
2169 | gimple def1 = SSA_NAME_DEF_STMT (arg1); | |
2170 | tree common_vuse; | |
2171 | ||
2172 | if (arg0 == arg1) | |
2173 | return arg0; | |
2174 | else if (gimple_nop_p (def0) | |
2175 | || (!gimple_nop_p (def1) | |
2176 | && dominated_by_p (CDI_DOMINATORS, | |
2177 | gimple_bb (def1), gimple_bb (def0)))) | |
2178 | { | |
4fd7a6de | 2179 | if (maybe_skip_until (phi, arg0, ref, arg1, cnt, |
2180 | visited, abort_on_visited)) | |
d7f69727 | 2181 | return arg0; |
2182 | } | |
2183 | else if (gimple_nop_p (def1) | |
2184 | || dominated_by_p (CDI_DOMINATORS, | |
2185 | gimple_bb (def0), gimple_bb (def1))) | |
2186 | { | |
4fd7a6de | 2187 | if (maybe_skip_until (phi, arg1, ref, arg0, cnt, |
2188 | visited, abort_on_visited)) | |
d7f69727 | 2189 | return arg1; |
2190 | } | |
2191 | /* Special case of a diamond: | |
2192 | MEM_1 = ... | |
2193 | goto (cond) ? L1 : L2 | |
2194 | L1: store1 = ... #MEM_2 = vuse(MEM_1) | |
2195 | goto L3 | |
2196 | L2: store2 = ... #MEM_3 = vuse(MEM_1) | |
2197 | L3: MEM_4 = PHI<MEM_2, MEM_3> | |
2198 | We were called with the PHI at L3, MEM_2 and MEM_3 don't | |
2199 | dominate each other, but still we can easily skip this PHI node | |
2200 | if we recognize that the vuse MEM operand is the same for both, | |
2201 | and that we can skip both statements (they don't clobber us). | |
2202 | This is still linear. Don't use maybe_skip_until, that might | |
2203 | potentially be slow. */ | |
2204 | else if ((common_vuse = gimple_vuse (def0)) | |
2205 | && common_vuse == gimple_vuse (def1)) | |
2206 | { | |
297a2110 | 2207 | *cnt += 2; |
d7f69727 | 2208 | if (!stmt_may_clobber_ref_p_1 (def0, ref) |
2209 | && !stmt_may_clobber_ref_p_1 (def1, ref)) | |
2210 | return common_vuse; | |
2211 | } | |
2212 | ||
2213 | return NULL_TREE; | |
2214 | } | |
2215 | ||
2216 | ||
dd277d48 | 2217 | /* Starting from a PHI node for the virtual operand of the memory reference |
2218 | REF find a continuation virtual operand that allows to continue walking | |
2219 | statements dominating PHI skipping only statements that cannot possibly | |
297a2110 | 2220 | clobber REF. Increments *CNT for each alias disambiguation done. |
2221 | Returns NULL_TREE if no suitable virtual operand can be found. */ | |
dd277d48 | 2222 | |
7814d418 | 2223 | tree |
297a2110 | 2224 | get_continuation_for_phi (gimple phi, ao_ref *ref, |
4fd7a6de | 2225 | unsigned int *cnt, bitmap *visited, |
2226 | bool abort_on_visited) | |
dd277d48 | 2227 | { |
2228 | unsigned nargs = gimple_phi_num_args (phi); | |
2229 | ||
2230 | /* Through a single-argument PHI we can simply look through. */ | |
2231 | if (nargs == 1) | |
2232 | return PHI_ARG_DEF (phi, 0); | |
2233 | ||
d7f69727 | 2234 | /* For two or more arguments try to pairwise skip non-aliasing code |
2235 | until we hit the phi argument definition that dominates the other one. */ | |
2236 | else if (nargs >= 2) | |
ac926412 | 2237 | { |
0afe880d | 2238 | tree arg0, arg1; |
2239 | unsigned i; | |
2240 | ||
2241 | /* Find a candidate for the virtual operand which definition | |
2242 | dominates those of all others. */ | |
2243 | arg0 = PHI_ARG_DEF (phi, 0); | |
2244 | if (!SSA_NAME_IS_DEFAULT_DEF (arg0)) | |
2245 | for (i = 1; i < nargs; ++i) | |
2246 | { | |
2247 | arg1 = PHI_ARG_DEF (phi, i); | |
2248 | if (SSA_NAME_IS_DEFAULT_DEF (arg1)) | |
2249 | { | |
2250 | arg0 = arg1; | |
2251 | break; | |
2252 | } | |
2253 | if (dominated_by_p (CDI_DOMINATORS, | |
2254 | gimple_bb (SSA_NAME_DEF_STMT (arg0)), | |
2255 | gimple_bb (SSA_NAME_DEF_STMT (arg1)))) | |
2256 | arg0 = arg1; | |
2257 | } | |
2258 | ||
2259 | /* Then pairwise reduce against the found candidate. */ | |
2260 | for (i = 0; i < nargs; ++i) | |
7814d418 | 2261 | { |
d7f69727 | 2262 | arg1 = PHI_ARG_DEF (phi, i); |
297a2110 | 2263 | arg0 = get_continuation_for_phi_1 (phi, arg0, arg1, ref, |
4fd7a6de | 2264 | cnt, visited, abort_on_visited); |
d7f69727 | 2265 | if (!arg0) |
2266 | return NULL_TREE; | |
7814d418 | 2267 | } |
d7f69727 | 2268 | |
2269 | return arg0; | |
ac926412 | 2270 | } |
dd277d48 | 2271 | |
2272 | return NULL_TREE; | |
ac926412 | 2273 | } |
516849c7 | 2274 | |
dd277d48 | 2275 | /* Based on the memory reference REF and its virtual use VUSE call |
2276 | WALKER for each virtual use that is equivalent to VUSE, including VUSE | |
2277 | itself. That is, for each virtual use for which its defining statement | |
2278 | does not clobber REF. | |
e683de6d | 2279 | |
dd277d48 | 2280 | WALKER is called with REF, the current virtual use and DATA. If |
2281 | WALKER returns non-NULL the walk stops and its result is returned. | |
2282 | At the end of a non-successful walk NULL is returned. | |
3857274c | 2283 | |
d8021dea | 2284 | TRANSLATE if non-NULL is called with a pointer to REF, the virtual |
2285 | use which definition is a statement that may clobber REF and DATA. | |
2286 | If TRANSLATE returns (void *)-1 the walk stops and NULL is returned. | |
2287 | If TRANSLATE returns non-NULL the walk stops and its result is returned. | |
2288 | If TRANSLATE returns NULL the walk continues and TRANSLATE is supposed | |
2289 | to adjust REF and *DATA to make that valid. | |
2290 | ||
dd277d48 | 2291 | TODO: Cache the vector of equivalent vuses per ref, vuse pair. */ |
2292 | ||
2293 | void * | |
3918bd18 | 2294 | walk_non_aliased_vuses (ao_ref *ref, tree vuse, |
297a2110 | 2295 | void *(*walker)(ao_ref *, tree, unsigned int, void *), |
3918bd18 | 2296 | void *(*translate)(ao_ref *, tree, void *), void *data) |
3857274c | 2297 | { |
dd277d48 | 2298 | bitmap visited = NULL; |
2299 | void *res; | |
297a2110 | 2300 | unsigned int cnt = 0; |
4fd7a6de | 2301 | bool translated = false; |
dd277d48 | 2302 | |
02c74b9b | 2303 | timevar_push (TV_ALIAS_STMT_WALK); |
2304 | ||
dd277d48 | 2305 | do |
2306 | { | |
2307 | gimple def_stmt; | |
3857274c | 2308 | |
02c74b9b | 2309 | /* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */ |
297a2110 | 2310 | res = (*walker) (ref, vuse, cnt, data); |
2311 | /* Abort walk. */ | |
2312 | if (res == (void *)-1) | |
2313 | { | |
2314 | res = NULL; | |
2315 | break; | |
2316 | } | |
2317 | /* Lookup succeeded. */ | |
2318 | else if (res != NULL) | |
dd277d48 | 2319 | break; |
3857274c | 2320 | |
dd277d48 | 2321 | def_stmt = SSA_NAME_DEF_STMT (vuse); |
2322 | if (gimple_nop_p (def_stmt)) | |
2323 | break; | |
2324 | else if (gimple_code (def_stmt) == GIMPLE_PHI) | |
4fd7a6de | 2325 | vuse = get_continuation_for_phi (def_stmt, ref, &cnt, |
2326 | &visited, translated); | |
dd277d48 | 2327 | else |
2328 | { | |
297a2110 | 2329 | cnt++; |
3918bd18 | 2330 | if (stmt_may_clobber_ref_p_1 (def_stmt, ref)) |
d8021dea | 2331 | { |
2332 | if (!translate) | |
2333 | break; | |
3918bd18 | 2334 | res = (*translate) (ref, vuse, data); |
d8021dea | 2335 | /* Failed lookup and translation. */ |
2336 | if (res == (void *)-1) | |
2337 | { | |
2338 | res = NULL; | |
2339 | break; | |
2340 | } | |
2341 | /* Lookup succeeded. */ | |
2342 | else if (res != NULL) | |
2343 | break; | |
2344 | /* Translation succeeded, continue walking. */ | |
4fd7a6de | 2345 | translated = true; |
d8021dea | 2346 | } |
dd277d48 | 2347 | vuse = gimple_vuse (def_stmt); |
2348 | } | |
2349 | } | |
2350 | while (vuse); | |
ac926412 | 2351 | |
dd277d48 | 2352 | if (visited) |
2353 | BITMAP_FREE (visited); | |
ac926412 | 2354 | |
02c74b9b | 2355 | timevar_pop (TV_ALIAS_STMT_WALK); |
2356 | ||
dd277d48 | 2357 | return res; |
3857274c | 2358 | } |
2359 | ||
604eef2c | 2360 | |
dd277d48 | 2361 | /* Based on the memory reference REF call WALKER for each vdef which |
2362 | defining statement may clobber REF, starting with VDEF. If REF | |
2363 | is NULL_TREE, each defining statement is visited. | |
2364 | ||
2365 | WALKER is called with REF, the current vdef and DATA. If WALKER | |
2366 | returns true the walk is stopped, otherwise it continues. | |
2367 | ||
2368 | At PHI nodes walk_aliased_vdefs forks into one walk for reach | |
2369 | PHI argument (but only one walk continues on merge points), the | |
2370 | return value is true if any of the walks was successful. | |
2371 | ||
2372 | The function returns the number of statements walked. */ | |
604eef2c | 2373 | |
2374 | static unsigned int | |
1daead67 | 2375 | walk_aliased_vdefs_1 (ao_ref *ref, tree vdef, |
2376 | bool (*walker)(ao_ref *, tree, void *), void *data, | |
dd277d48 | 2377 | bitmap *visited, unsigned int cnt) |
604eef2c | 2378 | { |
dd277d48 | 2379 | do |
2380 | { | |
2381 | gimple def_stmt = SSA_NAME_DEF_STMT (vdef); | |
604eef2c | 2382 | |
dd277d48 | 2383 | if (*visited |
2384 | && !bitmap_set_bit (*visited, SSA_NAME_VERSION (vdef))) | |
2385 | return cnt; | |
2386 | ||
2387 | if (gimple_nop_p (def_stmt)) | |
2388 | return cnt; | |
2389 | else if (gimple_code (def_stmt) == GIMPLE_PHI) | |
2390 | { | |
2391 | unsigned i; | |
2392 | if (!*visited) | |
2393 | *visited = BITMAP_ALLOC (NULL); | |
2394 | for (i = 0; i < gimple_phi_num_args (def_stmt); ++i) | |
2395 | cnt += walk_aliased_vdefs_1 (ref, gimple_phi_arg_def (def_stmt, i), | |
2396 | walker, data, visited, 0); | |
2397 | return cnt; | |
2398 | } | |
2399 | ||
02c74b9b | 2400 | /* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */ |
dd277d48 | 2401 | cnt++; |
2402 | if ((!ref | |
1daead67 | 2403 | || stmt_may_clobber_ref_p_1 (def_stmt, ref)) |
dd277d48 | 2404 | && (*walker) (ref, vdef, data)) |
2405 | return cnt; | |
2406 | ||
2407 | vdef = gimple_vuse (def_stmt); | |
2408 | } | |
2409 | while (1); | |
604eef2c | 2410 | } |
2411 | ||
dd277d48 | 2412 | unsigned int |
1daead67 | 2413 | walk_aliased_vdefs (ao_ref *ref, tree vdef, |
2414 | bool (*walker)(ao_ref *, tree, void *), void *data, | |
dd277d48 | 2415 | bitmap *visited) |
df3f0669 | 2416 | { |
dd277d48 | 2417 | bitmap local_visited = NULL; |
2418 | unsigned int ret; | |
2419 | ||
02c74b9b | 2420 | timevar_push (TV_ALIAS_STMT_WALK); |
2421 | ||
dd277d48 | 2422 | ret = walk_aliased_vdefs_1 (ref, vdef, walker, data, |
2423 | visited ? visited : &local_visited, 0); | |
2424 | if (local_visited) | |
2425 | BITMAP_FREE (local_visited); | |
2426 | ||
02c74b9b | 2427 | timevar_pop (TV_ALIAS_STMT_WALK); |
2428 | ||
dd277d48 | 2429 | return ret; |
2430 | } | |
2431 |