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4ee9c684 | 1 | /* Alias analysis for trees. |
3aea1f79 | 2 | Copyright (C) 2004-2014 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 "langhooks.h" |
31 | #include "flags.h" | |
32 | #include "function.h" | |
ce084dfc | 33 | #include "tree-pretty-print.h" |
b9ed1410 | 34 | #include "dumpfile.h" |
bc61cadb | 35 | #include "tree-ssa-alias.h" |
36 | #include "internal-fn.h" | |
37 | #include "tree-eh.h" | |
38 | #include "gimple-expr.h" | |
39 | #include "is-a.h" | |
75a70cf9 | 40 | #include "gimple.h" |
073c1fd5 | 41 | #include "gimple-ssa.h" |
9ed99284 | 42 | #include "stringpool.h" |
073c1fd5 | 43 | #include "tree-ssanames.h" |
9ed99284 | 44 | #include "expr.h" |
073c1fd5 | 45 | #include "tree-dfa.h" |
4ee9c684 | 46 | #include "tree-inline.h" |
4ee9c684 | 47 | #include "params.h" |
6cc9bd27 | 48 | #include "alloc-pool.h" |
dd277d48 | 49 | #include "tree-ssa-alias.h" |
dd9784d4 | 50 | #include "ipa-reference.h" |
a55dc2cd | 51 | |
dd277d48 | 52 | /* Broad overview of how alias analysis on gimple works: |
4fb5e5ca | 53 | |
dd277d48 | 54 | Statements clobbering or using memory are linked through the |
55 | virtual operand factored use-def chain. The virtual operand | |
56 | is unique per function, its symbol is accessible via gimple_vop (cfun). | |
57 | Virtual operands are used for efficiently walking memory statements | |
58 | in the gimple IL and are useful for things like value-numbering as | |
59 | a generation count for memory references. | |
339d7079 | 60 | |
dd277d48 | 61 | SSA_NAME pointers may have associated points-to information |
62 | accessible via the SSA_NAME_PTR_INFO macro. Flow-insensitive | |
63 | points-to information is (re-)computed by the TODO_rebuild_alias | |
64 | pass manager todo. Points-to information is also used for more | |
65 | precise tracking of call-clobbered and call-used variables and | |
66 | related disambiguations. | |
339d7079 | 67 | |
dd277d48 | 68 | This file contains functions for disambiguating memory references, |
69 | the so called alias-oracle and tools for walking of the gimple IL. | |
339d7079 | 70 | |
dd277d48 | 71 | The main alias-oracle entry-points are |
339d7079 | 72 | |
dd277d48 | 73 | bool stmt_may_clobber_ref_p (gimple, tree) |
339d7079 | 74 | |
dd277d48 | 75 | This function queries if a statement may invalidate (parts of) |
76 | the memory designated by the reference tree argument. | |
339d7079 | 77 | |
dd277d48 | 78 | bool ref_maybe_used_by_stmt_p (gimple, tree) |
339d7079 | 79 | |
dd277d48 | 80 | This function queries if a statement may need (parts of) the |
81 | memory designated by the reference tree argument. | |
339d7079 | 82 | |
dd277d48 | 83 | There are variants of these functions that only handle the call |
84 | part of a statement, call_may_clobber_ref_p and ref_maybe_used_by_call_p. | |
85 | Note that these do not disambiguate against a possible call lhs. | |
339d7079 | 86 | |
dd277d48 | 87 | bool refs_may_alias_p (tree, tree) |
339d7079 | 88 | |
dd277d48 | 89 | This function tries to disambiguate two reference trees. |
05931b00 | 90 | |
dd277d48 | 91 | bool ptr_deref_may_alias_global_p (tree) |
339d7079 | 92 | |
dd277d48 | 93 | This function queries if dereferencing a pointer variable may |
94 | alias global memory. | |
339d7079 | 95 | |
dd277d48 | 96 | More low-level disambiguators are available and documented in |
97 | this file. Low-level disambiguators dealing with points-to | |
98 | information are in tree-ssa-structalias.c. */ | |
339d7079 | 99 | |
339d7079 | 100 | |
dd277d48 | 101 | /* Query statistics for the different low-level disambiguators. |
102 | A high-level query may trigger multiple of them. */ | |
339d7079 | 103 | |
dd277d48 | 104 | static struct { |
105 | unsigned HOST_WIDE_INT refs_may_alias_p_may_alias; | |
106 | unsigned HOST_WIDE_INT refs_may_alias_p_no_alias; | |
107 | unsigned HOST_WIDE_INT ref_maybe_used_by_call_p_may_alias; | |
108 | unsigned HOST_WIDE_INT ref_maybe_used_by_call_p_no_alias; | |
109 | unsigned HOST_WIDE_INT call_may_clobber_ref_p_may_alias; | |
110 | unsigned HOST_WIDE_INT call_may_clobber_ref_p_no_alias; | |
111 | } alias_stats; | |
339d7079 | 112 | |
dd277d48 | 113 | void |
114 | dump_alias_stats (FILE *s) | |
115 | { | |
116 | fprintf (s, "\nAlias oracle query stats:\n"); | |
117 | fprintf (s, " refs_may_alias_p: " | |
118 | HOST_WIDE_INT_PRINT_DEC" disambiguations, " | |
119 | HOST_WIDE_INT_PRINT_DEC" queries\n", | |
120 | alias_stats.refs_may_alias_p_no_alias, | |
121 | alias_stats.refs_may_alias_p_no_alias | |
122 | + alias_stats.refs_may_alias_p_may_alias); | |
123 | fprintf (s, " ref_maybe_used_by_call_p: " | |
124 | HOST_WIDE_INT_PRINT_DEC" disambiguations, " | |
125 | HOST_WIDE_INT_PRINT_DEC" queries\n", | |
126 | alias_stats.ref_maybe_used_by_call_p_no_alias, | |
127 | alias_stats.refs_may_alias_p_no_alias | |
128 | + alias_stats.ref_maybe_used_by_call_p_may_alias); | |
129 | fprintf (s, " call_may_clobber_ref_p: " | |
130 | HOST_WIDE_INT_PRINT_DEC" disambiguations, " | |
131 | HOST_WIDE_INT_PRINT_DEC" queries\n", | |
132 | alias_stats.call_may_clobber_ref_p_no_alias, | |
133 | alias_stats.call_may_clobber_ref_p_no_alias | |
134 | + alias_stats.call_may_clobber_ref_p_may_alias); | |
135 | } | |
136 | ||
137 | ||
138 | /* Return true, if dereferencing PTR may alias with a global variable. */ | |
4ee9c684 | 139 | |
dd277d48 | 140 | bool |
141 | ptr_deref_may_alias_global_p (tree ptr) | |
4ee9c684 | 142 | { |
dd277d48 | 143 | struct ptr_info_def *pi; |
4fb5e5ca | 144 | |
dd277d48 | 145 | /* If we end up with a pointer constant here that may point |
146 | to global memory. */ | |
147 | if (TREE_CODE (ptr) != SSA_NAME) | |
148 | return true; | |
4ee9c684 | 149 | |
dd277d48 | 150 | pi = SSA_NAME_PTR_INFO (ptr); |
4ee9c684 | 151 | |
dd277d48 | 152 | /* If we do not have points-to information for this variable, |
153 | we have to punt. */ | |
154 | if (!pi) | |
155 | return true; | |
4ee9c684 | 156 | |
2a3ebafa | 157 | /* ??? This does not use TBAA to prune globals ptr may not access. */ |
dd277d48 | 158 | return pt_solution_includes_global (&pi->pt); |
4ee9c684 | 159 | } |
160 | ||
2a3ebafa | 161 | /* Return true if dereferencing PTR may alias DECL. |
162 | The caller is responsible for applying TBAA to see if PTR | |
163 | may access DECL at all. */ | |
4ee9c684 | 164 | |
dd277d48 | 165 | static bool |
166 | ptr_deref_may_alias_decl_p (tree ptr, tree decl) | |
4ee9c684 | 167 | { |
dd277d48 | 168 | struct ptr_info_def *pi; |
f7d118a9 | 169 | |
2760c0e3 | 170 | /* Conversions are irrelevant for points-to information and |
171 | data-dependence analysis can feed us those. */ | |
172 | STRIP_NOPS (ptr); | |
173 | ||
174 | /* Anything we do not explicilty handle aliases. */ | |
175 | if ((TREE_CODE (ptr) != SSA_NAME | |
176 | && TREE_CODE (ptr) != ADDR_EXPR | |
177 | && TREE_CODE (ptr) != POINTER_PLUS_EXPR) | |
178 | || !POINTER_TYPE_P (TREE_TYPE (ptr)) | |
179 | || (TREE_CODE (decl) != VAR_DECL | |
180 | && TREE_CODE (decl) != PARM_DECL | |
181 | && TREE_CODE (decl) != RESULT_DECL)) | |
9c01641d | 182 | return true; |
2fd0b5dc | 183 | |
2760c0e3 | 184 | /* Disregard pointer offsetting. */ |
185 | if (TREE_CODE (ptr) == POINTER_PLUS_EXPR) | |
186 | { | |
187 | do | |
188 | { | |
189 | ptr = TREE_OPERAND (ptr, 0); | |
190 | } | |
191 | while (TREE_CODE (ptr) == POINTER_PLUS_EXPR); | |
192 | return ptr_deref_may_alias_decl_p (ptr, decl); | |
193 | } | |
194 | ||
047fdd47 | 195 | /* ADDR_EXPR pointers either just offset another pointer or directly |
196 | specify the pointed-to set. */ | |
197 | if (TREE_CODE (ptr) == ADDR_EXPR) | |
198 | { | |
199 | tree base = get_base_address (TREE_OPERAND (ptr, 0)); | |
200 | if (base | |
2622064f | 201 | && (TREE_CODE (base) == MEM_REF |
202 | || TREE_CODE (base) == TARGET_MEM_REF)) | |
047fdd47 | 203 | ptr = TREE_OPERAND (base, 0); |
204 | else if (base | |
2622064f | 205 | && DECL_P (base)) |
7f2d9047 | 206 | return base == decl; |
047fdd47 | 207 | else if (base |
208 | && CONSTANT_CLASS_P (base)) | |
209 | return false; | |
210 | else | |
211 | return true; | |
212 | } | |
213 | ||
2760c0e3 | 214 | /* Non-aliased variables can not be pointed to. */ |
215 | if (!may_be_aliased (decl)) | |
216 | return false; | |
047fdd47 | 217 | |
dd277d48 | 218 | /* If we do not have useful points-to information for this pointer |
219 | we cannot disambiguate anything else. */ | |
220 | pi = SSA_NAME_PTR_INFO (ptr); | |
221 | if (!pi) | |
2fd0b5dc | 222 | return true; |
223 | ||
dd277d48 | 224 | return pt_solution_includes (&pi->pt, decl); |
2fd0b5dc | 225 | } |
4ee9c684 | 226 | |
2a3ebafa | 227 | /* Return true if dereferenced PTR1 and PTR2 may alias. |
228 | The caller is responsible for applying TBAA to see if accesses | |
229 | through PTR1 and PTR2 may conflict at all. */ | |
4ee9c684 | 230 | |
2760c0e3 | 231 | bool |
dd277d48 | 232 | ptr_derefs_may_alias_p (tree ptr1, tree ptr2) |
4ee9c684 | 233 | { |
dd277d48 | 234 | struct ptr_info_def *pi1, *pi2; |
4ee9c684 | 235 | |
2760c0e3 | 236 | /* Conversions are irrelevant for points-to information and |
237 | data-dependence analysis can feed us those. */ | |
238 | STRIP_NOPS (ptr1); | |
239 | STRIP_NOPS (ptr2); | |
240 | ||
2760c0e3 | 241 | /* Disregard pointer offsetting. */ |
242 | if (TREE_CODE (ptr1) == POINTER_PLUS_EXPR) | |
243 | { | |
244 | do | |
245 | { | |
246 | ptr1 = TREE_OPERAND (ptr1, 0); | |
247 | } | |
248 | while (TREE_CODE (ptr1) == POINTER_PLUS_EXPR); | |
249 | return ptr_derefs_may_alias_p (ptr1, ptr2); | |
250 | } | |
251 | if (TREE_CODE (ptr2) == POINTER_PLUS_EXPR) | |
252 | { | |
253 | do | |
254 | { | |
255 | ptr2 = TREE_OPERAND (ptr2, 0); | |
256 | } | |
257 | while (TREE_CODE (ptr2) == POINTER_PLUS_EXPR); | |
258 | return ptr_derefs_may_alias_p (ptr1, ptr2); | |
259 | } | |
f85fb819 | 260 | |
047fdd47 | 261 | /* ADDR_EXPR pointers either just offset another pointer or directly |
262 | specify the pointed-to set. */ | |
263 | if (TREE_CODE (ptr1) == ADDR_EXPR) | |
264 | { | |
265 | tree base = get_base_address (TREE_OPERAND (ptr1, 0)); | |
266 | if (base | |
2622064f | 267 | && (TREE_CODE (base) == MEM_REF |
268 | || TREE_CODE (base) == TARGET_MEM_REF)) | |
80b4d93e | 269 | return ptr_derefs_may_alias_p (TREE_OPERAND (base, 0), ptr2); |
047fdd47 | 270 | else if (base |
2622064f | 271 | && DECL_P (base)) |
047fdd47 | 272 | return ptr_deref_may_alias_decl_p (ptr2, base); |
273 | else | |
274 | return true; | |
275 | } | |
276 | if (TREE_CODE (ptr2) == ADDR_EXPR) | |
277 | { | |
278 | tree base = get_base_address (TREE_OPERAND (ptr2, 0)); | |
279 | if (base | |
2622064f | 280 | && (TREE_CODE (base) == MEM_REF |
281 | || TREE_CODE (base) == TARGET_MEM_REF)) | |
80b4d93e | 282 | return ptr_derefs_may_alias_p (ptr1, TREE_OPERAND (base, 0)); |
047fdd47 | 283 | else if (base |
2622064f | 284 | && DECL_P (base)) |
047fdd47 | 285 | return ptr_deref_may_alias_decl_p (ptr1, base); |
286 | else | |
287 | return true; | |
288 | } | |
289 | ||
80b4d93e | 290 | /* From here we require SSA name pointers. Anything else aliases. */ |
291 | if (TREE_CODE (ptr1) != SSA_NAME | |
292 | || TREE_CODE (ptr2) != SSA_NAME | |
293 | || !POINTER_TYPE_P (TREE_TYPE (ptr1)) | |
294 | || !POINTER_TYPE_P (TREE_TYPE (ptr2))) | |
295 | return true; | |
296 | ||
dd277d48 | 297 | /* We may end up with two empty points-to solutions for two same pointers. |
298 | In this case we still want to say both pointers alias, so shortcut | |
299 | that here. */ | |
300 | if (ptr1 == ptr2) | |
301 | return true; | |
81d08033 | 302 | |
dd277d48 | 303 | /* If we do not have useful points-to information for either pointer |
304 | we cannot disambiguate anything else. */ | |
305 | pi1 = SSA_NAME_PTR_INFO (ptr1); | |
306 | pi2 = SSA_NAME_PTR_INFO (ptr2); | |
307 | if (!pi1 || !pi2) | |
308 | return true; | |
81d08033 | 309 | |
2a3ebafa | 310 | /* ??? This does not use TBAA to prune decls from the intersection |
311 | that not both pointers may access. */ | |
dd277d48 | 312 | return pt_solutions_intersect (&pi1->pt, &pi2->pt); |
81d08033 | 313 | } |
314 | ||
047fdd47 | 315 | /* Return true if dereferencing PTR may alias *REF. |
316 | The caller is responsible for applying TBAA to see if PTR | |
317 | may access *REF at all. */ | |
318 | ||
319 | static bool | |
320 | ptr_deref_may_alias_ref_p_1 (tree ptr, ao_ref *ref) | |
321 | { | |
322 | tree base = ao_ref_base (ref); | |
323 | ||
2622064f | 324 | if (TREE_CODE (base) == MEM_REF |
325 | || TREE_CODE (base) == TARGET_MEM_REF) | |
047fdd47 | 326 | return ptr_derefs_may_alias_p (ptr, TREE_OPERAND (base, 0)); |
2622064f | 327 | else if (DECL_P (base)) |
047fdd47 | 328 | return ptr_deref_may_alias_decl_p (ptr, base); |
329 | ||
330 | return true; | |
331 | } | |
332 | ||
8763c223 | 333 | /* Return true whether REF may refer to global memory. */ |
334 | ||
335 | bool | |
336 | ref_may_alias_global_p (tree ref) | |
337 | { | |
338 | tree base = get_base_address (ref); | |
339 | if (DECL_P (base)) | |
340 | return is_global_var (base); | |
341 | else if (TREE_CODE (base) == MEM_REF | |
342 | || TREE_CODE (base) == TARGET_MEM_REF) | |
343 | return ptr_deref_may_alias_global_p (TREE_OPERAND (base, 0)); | |
344 | return true; | |
345 | } | |
346 | ||
347 | /* Return true whether STMT may clobber global memory. */ | |
348 | ||
349 | bool | |
350 | stmt_may_clobber_global_p (gimple stmt) | |
351 | { | |
352 | tree lhs; | |
353 | ||
354 | if (!gimple_vdef (stmt)) | |
355 | return false; | |
356 | ||
357 | /* ??? We can ask the oracle whether an artificial pointer | |
358 | dereference with a pointer with points-to information covering | |
359 | all global memory (what about non-address taken memory?) maybe | |
360 | clobbered by this call. As there is at the moment no convenient | |
361 | way of doing that without generating garbage do some manual | |
362 | checking instead. | |
363 | ??? We could make a NULL ao_ref argument to the various | |
364 | predicates special, meaning any global memory. */ | |
365 | ||
366 | switch (gimple_code (stmt)) | |
367 | { | |
368 | case GIMPLE_ASSIGN: | |
369 | lhs = gimple_assign_lhs (stmt); | |
370 | return (TREE_CODE (lhs) != SSA_NAME | |
371 | && ref_may_alias_global_p (lhs)); | |
372 | case GIMPLE_CALL: | |
373 | return true; | |
374 | default: | |
375 | return true; | |
376 | } | |
377 | } | |
378 | ||
4ee9c684 | 379 | |
380 | /* Dump alias information on FILE. */ | |
381 | ||
382 | void | |
383 | dump_alias_info (FILE *file) | |
384 | { | |
2aac21c5 | 385 | unsigned i; |
4ee9c684 | 386 | const char *funcname |
5135beeb | 387 | = lang_hooks.decl_printable_name (current_function_decl, 2); |
a55dc2cd | 388 | tree var; |
4ee9c684 | 389 | |
dd277d48 | 390 | fprintf (file, "\n\nAlias information for %s\n\n", funcname); |
81d08033 | 391 | |
392 | fprintf (file, "Aliased symbols\n\n"); | |
48e1416a | 393 | |
2aac21c5 | 394 | FOR_EACH_LOCAL_DECL (cfun, i, var) |
81d08033 | 395 | { |
81d08033 | 396 | if (may_be_aliased (var)) |
397 | dump_variable (file, var); | |
398 | } | |
399 | ||
7f81b5ee | 400 | fprintf (file, "\nCall clobber information\n"); |
401 | ||
402 | fprintf (file, "\nESCAPED"); | |
403 | dump_points_to_solution (file, &cfun->gimple_df->escaped); | |
7f81b5ee | 404 | |
405 | fprintf (file, "\n\nFlow-insensitive points-to information\n\n"); | |
81d08033 | 406 | |
81d08033 | 407 | for (i = 1; i < num_ssa_names; i++) |
408 | { | |
409 | tree ptr = ssa_name (i); | |
a48b1470 | 410 | struct ptr_info_def *pi; |
48e1416a | 411 | |
dd277d48 | 412 | if (ptr == NULL_TREE |
0cf78115 | 413 | || !POINTER_TYPE_P (TREE_TYPE (ptr)) |
dd277d48 | 414 | || SSA_NAME_IN_FREE_LIST (ptr)) |
a48b1470 | 415 | continue; |
416 | ||
417 | pi = SSA_NAME_PTR_INFO (ptr); | |
dd277d48 | 418 | if (pi) |
81d08033 | 419 | dump_points_to_info_for (file, ptr); |
420 | } | |
4ee9c684 | 421 | |
4ee9c684 | 422 | fprintf (file, "\n"); |
423 | } | |
424 | ||
425 | ||
426 | /* Dump alias information on stderr. */ | |
427 | ||
4b987fac | 428 | DEBUG_FUNCTION void |
4ee9c684 | 429 | debug_alias_info (void) |
430 | { | |
431 | dump_alias_info (stderr); | |
432 | } | |
433 | ||
434 | ||
7f81b5ee | 435 | /* Dump the points-to set *PT into FILE. */ |
4ee9c684 | 436 | |
d793732c | 437 | void |
7f81b5ee | 438 | dump_points_to_solution (FILE *file, struct pt_solution *pt) |
4ee9c684 | 439 | { |
7f81b5ee | 440 | if (pt->anything) |
441 | fprintf (file, ", points-to anything"); | |
4ee9c684 | 442 | |
7f81b5ee | 443 | if (pt->nonlocal) |
444 | fprintf (file, ", points-to non-local"); | |
4ee9c684 | 445 | |
7f81b5ee | 446 | if (pt->escaped) |
447 | fprintf (file, ", points-to escaped"); | |
448 | ||
1a981e1a | 449 | if (pt->ipa_escaped) |
450 | fprintf (file, ", points-to unit escaped"); | |
451 | ||
7f81b5ee | 452 | if (pt->null) |
453 | fprintf (file, ", points-to NULL"); | |
454 | ||
455 | if (pt->vars) | |
4ee9c684 | 456 | { |
7f81b5ee | 457 | fprintf (file, ", points-to vars: "); |
458 | dump_decl_set (file, pt->vars); | |
420582bc | 459 | if (pt->vars_contains_nonlocal |
460 | && pt->vars_contains_escaped_heap) | |
461 | fprintf (file, " (nonlocal, escaped heap)"); | |
462 | else if (pt->vars_contains_nonlocal | |
463 | && pt->vars_contains_escaped) | |
464 | fprintf (file, " (nonlocal, escaped)"); | |
465 | else if (pt->vars_contains_nonlocal) | |
466 | fprintf (file, " (nonlocal)"); | |
467 | else if (pt->vars_contains_escaped_heap) | |
468 | fprintf (file, " (escaped heap)"); | |
469 | else if (pt->vars_contains_escaped) | |
470 | fprintf (file, " (escaped)"); | |
7f81b5ee | 471 | } |
472 | } | |
4ee9c684 | 473 | |
c7d89805 | 474 | |
475 | /* Unified dump function for pt_solution. */ | |
476 | ||
477 | DEBUG_FUNCTION void | |
478 | debug (pt_solution &ref) | |
479 | { | |
480 | dump_points_to_solution (stderr, &ref); | |
481 | } | |
482 | ||
483 | DEBUG_FUNCTION void | |
484 | debug (pt_solution *ptr) | |
485 | { | |
486 | if (ptr) | |
487 | debug (*ptr); | |
488 | else | |
489 | fprintf (stderr, "<nil>\n"); | |
490 | } | |
491 | ||
492 | ||
7f81b5ee | 493 | /* Dump points-to information for SSA_NAME PTR into FILE. */ |
4ee9c684 | 494 | |
7f81b5ee | 495 | void |
496 | dump_points_to_info_for (FILE *file, tree ptr) | |
497 | { | |
498 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr); | |
4ee9c684 | 499 | |
7f81b5ee | 500 | print_generic_expr (file, ptr, dump_flags); |
1e1a4c8c | 501 | |
7f81b5ee | 502 | if (pi) |
503 | dump_points_to_solution (file, &pi->pt); | |
504 | else | |
505 | fprintf (file, ", points-to anything"); | |
4ee9c684 | 506 | |
507 | fprintf (file, "\n"); | |
508 | } | |
509 | ||
510 | ||
d793732c | 511 | /* Dump points-to information for VAR into stderr. */ |
512 | ||
4b987fac | 513 | DEBUG_FUNCTION void |
d793732c | 514 | debug_points_to_info_for (tree var) |
515 | { | |
516 | dump_points_to_info_for (stderr, var); | |
517 | } | |
518 | ||
3918bd18 | 519 | |
520 | /* Initializes the alias-oracle reference representation *R from REF. */ | |
521 | ||
522 | void | |
523 | ao_ref_init (ao_ref *r, tree ref) | |
524 | { | |
525 | r->ref = ref; | |
526 | r->base = NULL_TREE; | |
527 | r->offset = 0; | |
528 | r->size = -1; | |
529 | r->max_size = -1; | |
530 | r->ref_alias_set = -1; | |
531 | r->base_alias_set = -1; | |
3787db52 | 532 | r->volatile_p = ref ? TREE_THIS_VOLATILE (ref) : false; |
3918bd18 | 533 | } |
534 | ||
535 | /* Returns the base object of the memory reference *REF. */ | |
536 | ||
537 | tree | |
538 | ao_ref_base (ao_ref *ref) | |
539 | { | |
540 | if (ref->base) | |
541 | return ref->base; | |
542 | ref->base = get_ref_base_and_extent (ref->ref, &ref->offset, &ref->size, | |
543 | &ref->max_size); | |
544 | return ref->base; | |
545 | } | |
546 | ||
547 | /* Returns the base object alias set of the memory reference *REF. */ | |
548 | ||
182cf5a9 | 549 | static alias_set_type |
3918bd18 | 550 | ao_ref_base_alias_set (ao_ref *ref) |
551 | { | |
182cf5a9 | 552 | tree base_ref; |
3918bd18 | 553 | if (ref->base_alias_set != -1) |
554 | return ref->base_alias_set; | |
182cf5a9 | 555 | if (!ref->ref) |
556 | return 0; | |
557 | base_ref = ref->ref; | |
558 | while (handled_component_p (base_ref)) | |
559 | base_ref = TREE_OPERAND (base_ref, 0); | |
560 | ref->base_alias_set = get_alias_set (base_ref); | |
3918bd18 | 561 | return ref->base_alias_set; |
562 | } | |
563 | ||
564 | /* Returns the reference alias set of the memory reference *REF. */ | |
565 | ||
566 | alias_set_type | |
567 | ao_ref_alias_set (ao_ref *ref) | |
568 | { | |
569 | if (ref->ref_alias_set != -1) | |
570 | return ref->ref_alias_set; | |
571 | ref->ref_alias_set = get_alias_set (ref->ref); | |
572 | return ref->ref_alias_set; | |
573 | } | |
574 | ||
134899ac | 575 | /* Init an alias-oracle reference representation from a gimple pointer |
234f1f79 | 576 | PTR and a gimple size SIZE in bytes. If SIZE is NULL_TREE then the |
134899ac | 577 | size is assumed to be unknown. The access is assumed to be only |
578 | to or after of the pointer target, not before it. */ | |
579 | ||
580 | void | |
581 | ao_ref_init_from_ptr_and_size (ao_ref *ref, tree ptr, tree size) | |
582 | { | |
dd49bf5f | 583 | HOST_WIDE_INT t, size_hwi, extra_offset = 0; |
134899ac | 584 | ref->ref = NULL_TREE; |
4e9e79c0 | 585 | if (TREE_CODE (ptr) == SSA_NAME) |
586 | { | |
587 | gimple stmt = SSA_NAME_DEF_STMT (ptr); | |
588 | if (gimple_assign_single_p (stmt) | |
589 | && gimple_assign_rhs_code (stmt) == ADDR_EXPR) | |
590 | ptr = gimple_assign_rhs1 (stmt); | |
e3ac92d2 | 591 | else if (is_gimple_assign (stmt) |
592 | && gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR | |
234f1f79 | 593 | && TREE_CODE (gimple_assign_rhs2 (stmt)) == INTEGER_CST) |
e3ac92d2 | 594 | { |
595 | ptr = gimple_assign_rhs1 (stmt); | |
234f1f79 | 596 | extra_offset = BITS_PER_UNIT |
597 | * int_cst_value (gimple_assign_rhs2 (stmt)); | |
e3ac92d2 | 598 | } |
4e9e79c0 | 599 | } |
600 | ||
134899ac | 601 | if (TREE_CODE (ptr) == ADDR_EXPR) |
d1603825 | 602 | { |
603 | ref->base = get_addr_base_and_unit_offset (TREE_OPERAND (ptr, 0), &t); | |
604 | if (ref->base) | |
605 | ref->offset = BITS_PER_UNIT * t; | |
606 | else | |
607 | { | |
608 | size = NULL_TREE; | |
609 | ref->offset = 0; | |
610 | ref->base = get_base_address (TREE_OPERAND (ptr, 0)); | |
611 | } | |
612 | } | |
134899ac | 613 | else |
614 | { | |
182cf5a9 | 615 | ref->base = build2 (MEM_REF, char_type_node, |
2512209b | 616 | ptr, null_pointer_node); |
134899ac | 617 | ref->offset = 0; |
618 | } | |
e3ac92d2 | 619 | ref->offset += extra_offset; |
134899ac | 620 | if (size |
35ec552a | 621 | && tree_fits_shwi_p (size) |
dd49bf5f | 622 | && (size_hwi = tree_to_shwi (size)) <= HOST_WIDE_INT_MAX / BITS_PER_UNIT) |
623 | ref->max_size = ref->size = size_hwi * BITS_PER_UNIT; | |
134899ac | 624 | else |
625 | ref->max_size = ref->size = -1; | |
626 | ref->ref_alias_set = 0; | |
627 | ref->base_alias_set = 0; | |
3787db52 | 628 | ref->volatile_p = false; |
134899ac | 629 | } |
630 | ||
dd277d48 | 631 | /* Return 1 if TYPE1 and TYPE2 are to be considered equivalent for the |
632 | purpose of TBAA. Return 0 if they are distinct and -1 if we cannot | |
633 | decide. */ | |
d793732c | 634 | |
dd277d48 | 635 | static inline int |
636 | same_type_for_tbaa (tree type1, tree type2) | |
637 | { | |
638 | type1 = TYPE_MAIN_VARIANT (type1); | |
639 | type2 = TYPE_MAIN_VARIANT (type2); | |
4ee9c684 | 640 | |
dd277d48 | 641 | /* If we would have to do structural comparison bail out. */ |
642 | if (TYPE_STRUCTURAL_EQUALITY_P (type1) | |
643 | || TYPE_STRUCTURAL_EQUALITY_P (type2)) | |
644 | return -1; | |
645 | ||
646 | /* Compare the canonical types. */ | |
647 | if (TYPE_CANONICAL (type1) == TYPE_CANONICAL (type2)) | |
648 | return 1; | |
649 | ||
4b4d1513 | 650 | /* ??? Array types are not properly unified in all cases as we have |
dd277d48 | 651 | spurious changes in the index types for example. Removing this |
652 | causes all sorts of problems with the Fortran frontend. */ | |
653 | if (TREE_CODE (type1) == ARRAY_TYPE | |
654 | && TREE_CODE (type2) == ARRAY_TYPE) | |
655 | return -1; | |
656 | ||
102bfc9c | 657 | /* ??? In Ada, an lvalue of an unconstrained type can be used to access an |
658 | object of one of its constrained subtypes, e.g. when a function with an | |
659 | unconstrained parameter passed by reference is called on an object and | |
660 | inlined. But, even in the case of a fixed size, type and subtypes are | |
661 | not equivalent enough as to share the same TYPE_CANONICAL, since this | |
662 | would mean that conversions between them are useless, whereas they are | |
663 | not (e.g. type and subtypes can have different modes). So, in the end, | |
664 | they are only guaranteed to have the same alias set. */ | |
665 | if (get_alias_set (type1) == get_alias_set (type2)) | |
4b4d1513 | 666 | return -1; |
667 | ||
dd277d48 | 668 | /* The types are known to be not equal. */ |
669 | return 0; | |
670 | } | |
671 | ||
672 | /* Determine if the two component references REF1 and REF2 which are | |
673 | based on access types TYPE1 and TYPE2 and of which at least one is based | |
ac30e3b2 | 674 | on an indirect reference may alias. REF2 is the only one that can |
675 | be a decl in which case REF2_IS_DECL is true. | |
676 | REF1_ALIAS_SET, BASE1_ALIAS_SET, REF2_ALIAS_SET and BASE2_ALIAS_SET | |
677 | are the respective alias sets. */ | |
dd277d48 | 678 | |
679 | static bool | |
0d2f7431 | 680 | aliasing_component_refs_p (tree ref1, |
ac30e3b2 | 681 | alias_set_type ref1_alias_set, |
682 | alias_set_type base1_alias_set, | |
a42ce2cc | 683 | HOST_WIDE_INT offset1, HOST_WIDE_INT max_size1, |
0d2f7431 | 684 | tree ref2, |
ac30e3b2 | 685 | alias_set_type ref2_alias_set, |
686 | alias_set_type base2_alias_set, | |
687 | HOST_WIDE_INT offset2, HOST_WIDE_INT max_size2, | |
688 | bool ref2_is_decl) | |
dd277d48 | 689 | { |
690 | /* If one reference is a component references through pointers try to find a | |
691 | common base and apply offset based disambiguation. This handles | |
692 | for example | |
693 | struct A { int i; int j; } *q; | |
694 | struct B { struct A a; int k; } *p; | |
695 | disambiguating q->i and p->a.j. */ | |
0d2f7431 | 696 | tree base1, base2; |
697 | tree type1, type2; | |
dd277d48 | 698 | tree *refp; |
699 | int same_p; | |
700 | ||
0d2f7431 | 701 | /* Choose bases and base types to search for. */ |
702 | base1 = ref1; | |
703 | while (handled_component_p (base1)) | |
704 | base1 = TREE_OPERAND (base1, 0); | |
705 | type1 = TREE_TYPE (base1); | |
706 | base2 = ref2; | |
707 | while (handled_component_p (base2)) | |
708 | base2 = TREE_OPERAND (base2, 0); | |
709 | type2 = TREE_TYPE (base2); | |
710 | ||
dd277d48 | 711 | /* Now search for the type1 in the access path of ref2. This |
712 | would be a common base for doing offset based disambiguation on. */ | |
bc3c318e | 713 | refp = &ref2; |
dd277d48 | 714 | while (handled_component_p (*refp) |
715 | && same_type_for_tbaa (TREE_TYPE (*refp), type1) == 0) | |
716 | refp = &TREE_OPERAND (*refp, 0); | |
717 | same_p = same_type_for_tbaa (TREE_TYPE (*refp), type1); | |
718 | /* If we couldn't compare types we have to bail out. */ | |
719 | if (same_p == -1) | |
720 | return true; | |
721 | else if (same_p == 1) | |
722 | { | |
723 | HOST_WIDE_INT offadj, sztmp, msztmp; | |
724 | get_ref_base_and_extent (*refp, &offadj, &sztmp, &msztmp); | |
725 | offset2 -= offadj; | |
0d2f7431 | 726 | get_ref_base_and_extent (base1, &offadj, &sztmp, &msztmp); |
727 | offset1 -= offadj; | |
dd277d48 | 728 | return ranges_overlap_p (offset1, max_size1, offset2, max_size2); |
729 | } | |
730 | /* If we didn't find a common base, try the other way around. */ | |
bc3c318e | 731 | refp = &ref1; |
dd277d48 | 732 | while (handled_component_p (*refp) |
733 | && same_type_for_tbaa (TREE_TYPE (*refp), type2) == 0) | |
734 | refp = &TREE_OPERAND (*refp, 0); | |
735 | same_p = same_type_for_tbaa (TREE_TYPE (*refp), type2); | |
736 | /* If we couldn't compare types we have to bail out. */ | |
737 | if (same_p == -1) | |
738 | return true; | |
739 | else if (same_p == 1) | |
740 | { | |
741 | HOST_WIDE_INT offadj, sztmp, msztmp; | |
742 | get_ref_base_and_extent (*refp, &offadj, &sztmp, &msztmp); | |
743 | offset1 -= offadj; | |
0d2f7431 | 744 | get_ref_base_and_extent (base2, &offadj, &sztmp, &msztmp); |
745 | offset2 -= offadj; | |
dd277d48 | 746 | return ranges_overlap_p (offset1, max_size1, offset2, max_size2); |
747 | } | |
ac30e3b2 | 748 | |
4b4d1513 | 749 | /* If we have two type access paths B1.path1 and B2.path2 they may |
ac30e3b2 | 750 | only alias if either B1 is in B2.path2 or B2 is in B1.path1. |
751 | But we can still have a path that goes B1.path1...B2.path2 with | |
752 | a part that we do not see. So we can only disambiguate now | |
753 | if there is no B2 in the tail of path1 and no B1 on the | |
754 | tail of path2. */ | |
755 | if (base1_alias_set == ref2_alias_set | |
756 | || alias_set_subset_of (base1_alias_set, ref2_alias_set)) | |
757 | return true; | |
758 | /* If this is ptr vs. decl then we know there is no ptr ... decl path. */ | |
759 | if (!ref2_is_decl) | |
760 | return (base2_alias_set == ref1_alias_set | |
761 | || alias_set_subset_of (base2_alias_set, ref1_alias_set)); | |
4b4d1513 | 762 | return false; |
dd277d48 | 763 | } |
764 | ||
740a2cb6 | 765 | /* Return true if we can determine that component references REF1 and REF2, |
766 | that are within a common DECL, cannot overlap. */ | |
767 | ||
768 | static bool | |
769 | nonoverlapping_component_refs_of_decl_p (tree ref1, tree ref2) | |
770 | { | |
4997014d | 771 | auto_vec<tree, 16> component_refs1; |
772 | auto_vec<tree, 16> component_refs2; | |
740a2cb6 | 773 | |
774 | /* Create the stack of handled components for REF1. */ | |
775 | while (handled_component_p (ref1)) | |
776 | { | |
777 | component_refs1.safe_push (ref1); | |
778 | ref1 = TREE_OPERAND (ref1, 0); | |
779 | } | |
780 | if (TREE_CODE (ref1) == MEM_REF) | |
781 | { | |
782 | if (!integer_zerop (TREE_OPERAND (ref1, 1))) | |
783 | goto may_overlap; | |
784 | ref1 = TREE_OPERAND (TREE_OPERAND (ref1, 0), 0); | |
785 | } | |
786 | ||
787 | /* Create the stack of handled components for REF2. */ | |
788 | while (handled_component_p (ref2)) | |
789 | { | |
790 | component_refs2.safe_push (ref2); | |
791 | ref2 = TREE_OPERAND (ref2, 0); | |
792 | } | |
793 | if (TREE_CODE (ref2) == MEM_REF) | |
794 | { | |
795 | if (!integer_zerop (TREE_OPERAND (ref2, 1))) | |
796 | goto may_overlap; | |
797 | ref2 = TREE_OPERAND (TREE_OPERAND (ref2, 0), 0); | |
798 | } | |
799 | ||
800 | /* We must have the same base DECL. */ | |
801 | gcc_assert (ref1 == ref2); | |
802 | ||
803 | /* Pop the stacks in parallel and examine the COMPONENT_REFs of the same | |
804 | rank. This is sufficient because we start from the same DECL and you | |
805 | cannot reference several fields at a time with COMPONENT_REFs (unlike | |
806 | with ARRAY_RANGE_REFs for arrays) so you always need the same number | |
807 | of them to access a sub-component, unless you're in a union, in which | |
808 | case the return value will precisely be false. */ | |
809 | while (true) | |
810 | { | |
811 | do | |
812 | { | |
813 | if (component_refs1.is_empty ()) | |
814 | goto may_overlap; | |
815 | ref1 = component_refs1.pop (); | |
816 | } | |
817 | while (!RECORD_OR_UNION_TYPE_P (TREE_TYPE (TREE_OPERAND (ref1, 0)))); | |
818 | ||
819 | do | |
820 | { | |
821 | if (component_refs2.is_empty ()) | |
822 | goto may_overlap; | |
823 | ref2 = component_refs2.pop (); | |
824 | } | |
825 | while (!RECORD_OR_UNION_TYPE_P (TREE_TYPE (TREE_OPERAND (ref2, 0)))); | |
826 | ||
827 | /* Beware of BIT_FIELD_REF. */ | |
828 | if (TREE_CODE (ref1) != COMPONENT_REF | |
829 | || TREE_CODE (ref2) != COMPONENT_REF) | |
830 | goto may_overlap; | |
831 | ||
832 | tree field1 = TREE_OPERAND (ref1, 1); | |
833 | tree field2 = TREE_OPERAND (ref2, 1); | |
834 | ||
835 | /* ??? We cannot simply use the type of operand #0 of the refs here | |
836 | as the Fortran compiler smuggles type punning into COMPONENT_REFs | |
837 | for common blocks instead of using unions like everyone else. */ | |
838 | tree type1 = TYPE_MAIN_VARIANT (DECL_CONTEXT (field1)); | |
839 | tree type2 = TYPE_MAIN_VARIANT (DECL_CONTEXT (field2)); | |
840 | ||
841 | /* We cannot disambiguate fields in a union or qualified union. */ | |
842 | if (type1 != type2 || TREE_CODE (type1) != RECORD_TYPE) | |
843 | goto may_overlap; | |
844 | ||
11ad02c6 | 845 | /* Different fields of the same record type cannot overlap. |
846 | ??? Bitfields can overlap at RTL level so punt on them. */ | |
740a2cb6 | 847 | if (field1 != field2) |
848 | { | |
849 | component_refs1.release (); | |
850 | component_refs2.release (); | |
11ad02c6 | 851 | return !(DECL_BIT_FIELD (field1) && DECL_BIT_FIELD (field2)); |
740a2cb6 | 852 | } |
853 | } | |
854 | ||
855 | may_overlap: | |
856 | component_refs1.release (); | |
857 | component_refs2.release (); | |
858 | return false; | |
859 | } | |
860 | ||
f270d2a0 | 861 | /* qsort compare function to sort FIELD_DECLs after their |
862 | DECL_FIELD_CONTEXT TYPE_UID. */ | |
863 | ||
864 | static inline int | |
865 | ncr_compar (const void *field1_, const void *field2_) | |
866 | { | |
867 | const_tree field1 = *(const_tree *) const_cast <void *>(field1_); | |
868 | const_tree field2 = *(const_tree *) const_cast <void *>(field2_); | |
869 | unsigned int uid1 | |
870 | = TYPE_UID (TYPE_MAIN_VARIANT (DECL_FIELD_CONTEXT (field1))); | |
871 | unsigned int uid2 | |
872 | = TYPE_UID (TYPE_MAIN_VARIANT (DECL_FIELD_CONTEXT (field2))); | |
873 | if (uid1 < uid2) | |
874 | return -1; | |
875 | else if (uid1 > uid2) | |
876 | return 1; | |
877 | return 0; | |
878 | } | |
879 | ||
880 | /* Return true if we can determine that the fields referenced cannot | |
881 | overlap for any pair of objects. */ | |
882 | ||
883 | static bool | |
884 | nonoverlapping_component_refs_p (const_tree x, const_tree y) | |
885 | { | |
886 | if (!flag_strict_aliasing | |
887 | || !x || !y | |
888 | || TREE_CODE (x) != COMPONENT_REF | |
889 | || TREE_CODE (y) != COMPONENT_REF) | |
890 | return false; | |
891 | ||
892 | auto_vec<const_tree, 16> fieldsx; | |
893 | while (TREE_CODE (x) == COMPONENT_REF) | |
894 | { | |
895 | tree field = TREE_OPERAND (x, 1); | |
896 | tree type = TYPE_MAIN_VARIANT (DECL_FIELD_CONTEXT (field)); | |
897 | if (TREE_CODE (type) == RECORD_TYPE) | |
898 | fieldsx.safe_push (field); | |
899 | x = TREE_OPERAND (x, 0); | |
900 | } | |
901 | if (fieldsx.length () == 0) | |
902 | return false; | |
903 | auto_vec<const_tree, 16> fieldsy; | |
904 | while (TREE_CODE (y) == COMPONENT_REF) | |
905 | { | |
906 | tree field = TREE_OPERAND (y, 1); | |
907 | tree type = TYPE_MAIN_VARIANT (DECL_FIELD_CONTEXT (field)); | |
908 | if (TREE_CODE (type) == RECORD_TYPE) | |
909 | fieldsy.safe_push (TREE_OPERAND (y, 1)); | |
910 | y = TREE_OPERAND (y, 0); | |
911 | } | |
912 | if (fieldsy.length () == 0) | |
913 | return false; | |
914 | ||
915 | /* Most common case first. */ | |
916 | if (fieldsx.length () == 1 | |
917 | && fieldsy.length () == 1) | |
918 | return ((TYPE_MAIN_VARIANT (DECL_FIELD_CONTEXT (fieldsx[0])) | |
919 | == TYPE_MAIN_VARIANT (DECL_FIELD_CONTEXT (fieldsy[0]))) | |
920 | && fieldsx[0] != fieldsy[0] | |
921 | && !(DECL_BIT_FIELD (fieldsx[0]) && DECL_BIT_FIELD (fieldsy[0]))); | |
922 | ||
923 | if (fieldsx.length () == 2) | |
924 | { | |
925 | if (ncr_compar (&fieldsx[0], &fieldsx[1]) == 1) | |
926 | { | |
927 | const_tree tem = fieldsx[0]; | |
928 | fieldsx[0] = fieldsx[1]; | |
929 | fieldsx[1] = tem; | |
930 | } | |
931 | } | |
932 | else | |
933 | fieldsx.qsort (ncr_compar); | |
934 | ||
935 | if (fieldsy.length () == 2) | |
936 | { | |
937 | if (ncr_compar (&fieldsy[0], &fieldsy[1]) == 1) | |
938 | { | |
939 | const_tree tem = fieldsy[0]; | |
940 | fieldsy[0] = fieldsy[1]; | |
941 | fieldsy[1] = tem; | |
942 | } | |
943 | } | |
944 | else | |
945 | fieldsy.qsort (ncr_compar); | |
946 | ||
947 | unsigned i = 0, j = 0; | |
948 | do | |
949 | { | |
950 | const_tree fieldx = fieldsx[i]; | |
951 | const_tree fieldy = fieldsy[j]; | |
952 | tree typex = TYPE_MAIN_VARIANT (DECL_FIELD_CONTEXT (fieldx)); | |
953 | tree typey = TYPE_MAIN_VARIANT (DECL_FIELD_CONTEXT (fieldy)); | |
954 | if (typex == typey) | |
955 | { | |
956 | /* We're left with accessing different fields of a structure, | |
957 | no possible overlap, unless they are both bitfields. */ | |
958 | if (fieldx != fieldy) | |
959 | return !(DECL_BIT_FIELD (fieldx) && DECL_BIT_FIELD (fieldy)); | |
960 | } | |
961 | if (TYPE_UID (typex) < TYPE_UID (typey)) | |
962 | { | |
963 | i++; | |
964 | if (i == fieldsx.length ()) | |
965 | break; | |
966 | } | |
967 | else | |
968 | { | |
969 | j++; | |
970 | if (j == fieldsy.length ()) | |
971 | break; | |
972 | } | |
973 | } | |
974 | while (1); | |
975 | ||
976 | return false; | |
977 | } | |
978 | ||
979 | ||
dd277d48 | 980 | /* Return true if two memory references based on the variables BASE1 |
077ad5ad | 981 | and BASE2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and |
740a2cb6 | 982 | [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. REF1 and REF2 |
983 | if non-NULL are the complete memory reference trees. */ | |
dd277d48 | 984 | |
985 | static bool | |
740a2cb6 | 986 | decl_refs_may_alias_p (tree ref1, tree base1, |
dd277d48 | 987 | HOST_WIDE_INT offset1, HOST_WIDE_INT max_size1, |
740a2cb6 | 988 | tree ref2, tree base2, |
dd277d48 | 989 | HOST_WIDE_INT offset2, HOST_WIDE_INT max_size2) |
4ee9c684 | 990 | { |
2622064f | 991 | gcc_checking_assert (DECL_P (base1) && DECL_P (base2)); |
4ee9c684 | 992 | |
dd277d48 | 993 | /* If both references are based on different variables, they cannot alias. */ |
7f2d9047 | 994 | if (base1 != base2) |
dd277d48 | 995 | return false; |
4ee9c684 | 996 | |
dd277d48 | 997 | /* If both references are based on the same variable, they cannot alias if |
998 | the accesses do not overlap. */ | |
740a2cb6 | 999 | if (!ranges_overlap_p (offset1, max_size1, offset2, max_size2)) |
1000 | return false; | |
1001 | ||
1002 | /* For components with variable position, the above test isn't sufficient, | |
1003 | so we disambiguate component references manually. */ | |
1004 | if (ref1 && ref2 | |
1005 | && handled_component_p (ref1) && handled_component_p (ref2) | |
1006 | && nonoverlapping_component_refs_of_decl_p (ref1, ref2)) | |
1007 | return false; | |
1008 | ||
1009 | return true; | |
dd277d48 | 1010 | } |
1011 | ||
1012 | /* Return true if an indirect reference based on *PTR1 constrained | |
077ad5ad | 1013 | to [OFFSET1, OFFSET1 + MAX_SIZE1) may alias a variable based on BASE2 |
1014 | constrained to [OFFSET2, OFFSET2 + MAX_SIZE2). *PTR1 and BASE2 have | |
dd277d48 | 1015 | the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1 |
1016 | in which case they are computed on-demand. REF1 and REF2 | |
1017 | if non-NULL are the complete memory reference trees. */ | |
1018 | ||
1019 | static bool | |
182cf5a9 | 1020 | indirect_ref_may_alias_decl_p (tree ref1 ATTRIBUTE_UNUSED, tree base1, |
1021 | HOST_WIDE_INT offset1, | |
1022 | HOST_WIDE_INT max_size1 ATTRIBUTE_UNUSED, | |
ac30e3b2 | 1023 | alias_set_type ref1_alias_set, |
dd277d48 | 1024 | alias_set_type base1_alias_set, |
182cf5a9 | 1025 | tree ref2 ATTRIBUTE_UNUSED, tree base2, |
dd277d48 | 1026 | HOST_WIDE_INT offset2, HOST_WIDE_INT max_size2, |
ac30e3b2 | 1027 | alias_set_type ref2_alias_set, |
182cf5a9 | 1028 | alias_set_type base2_alias_set, bool tbaa_p) |
dd277d48 | 1029 | { |
9a14ba4f | 1030 | tree ptr1; |
061b1263 | 1031 | tree ptrtype1, dbase2; |
7749ee1c | 1032 | HOST_WIDE_INT offset1p = offset1, offset2p = offset2; |
061b1263 | 1033 | HOST_WIDE_INT doffset1, doffset2; |
2622064f | 1034 | double_int moff; |
1035 | ||
1036 | gcc_checking_assert ((TREE_CODE (base1) == MEM_REF | |
1037 | || TREE_CODE (base1) == TARGET_MEM_REF) | |
1038 | && DECL_P (base2)); | |
182cf5a9 | 1039 | |
28daba6f | 1040 | ptr1 = TREE_OPERAND (base1, 0); |
9a14ba4f | 1041 | |
7749ee1c | 1042 | /* The offset embedded in MEM_REFs can be negative. Bias them |
1043 | so that the resulting offset adjustment is positive. */ | |
2622064f | 1044 | moff = mem_ref_offset (base1); |
9a8b9e26 | 1045 | moff = moff.lshift (BITS_PER_UNIT == 8 ? 3 : exact_log2 (BITS_PER_UNIT)); |
cf8f0e63 | 1046 | if (moff.is_negative ()) |
1047 | offset2p += (-moff).low; | |
2622064f | 1048 | else |
1049 | offset1p += moff.low; | |
182cf5a9 | 1050 | |
dd277d48 | 1051 | /* If only one reference is based on a variable, they cannot alias if |
1052 | the pointer access is beyond the extent of the variable access. | |
1053 | (the pointer base cannot validly point to an offset less than zero | |
1054 | of the variable). | |
a07f6629 | 1055 | ??? IVOPTs creates bases that do not honor this restriction, |
1056 | so do not apply this optimization for TARGET_MEM_REFs. */ | |
1057 | if (TREE_CODE (base1) != TARGET_MEM_REF | |
9a14ba4f | 1058 | && !ranges_overlap_p (MAX (0, offset1p), -1, offset2p, max_size2)) |
dd277d48 | 1059 | return false; |
a07f6629 | 1060 | /* They also cannot alias if the pointer may not point to the decl. */ |
dd277d48 | 1061 | if (!ptr_deref_may_alias_decl_p (ptr1, base2)) |
1062 | return false; | |
1063 | ||
1064 | /* Disambiguations that rely on strict aliasing rules follow. */ | |
182cf5a9 | 1065 | if (!flag_strict_aliasing || !tbaa_p) |
dd277d48 | 1066 | return true; |
1067 | ||
2622064f | 1068 | ptrtype1 = TREE_TYPE (TREE_OPERAND (base1, 1)); |
182cf5a9 | 1069 | |
dd277d48 | 1070 | /* If the alias set for a pointer access is zero all bets are off. */ |
1071 | if (base1_alias_set == -1) | |
182cf5a9 | 1072 | base1_alias_set = get_deref_alias_set (ptrtype1); |
dd277d48 | 1073 | if (base1_alias_set == 0) |
1074 | return true; | |
1075 | if (base2_alias_set == -1) | |
1076 | base2_alias_set = get_alias_set (base2); | |
1077 | ||
182cf5a9 | 1078 | /* When we are trying to disambiguate an access with a pointer dereference |
1079 | as base versus one with a decl as base we can use both the size | |
1080 | of the decl and its dynamic type for extra disambiguation. | |
1081 | ??? We do not know anything about the dynamic type of the decl | |
1082 | other than that its alias-set contains base2_alias_set as a subset | |
1083 | which does not help us here. */ | |
1084 | /* As we know nothing useful about the dynamic type of the decl just | |
1085 | use the usual conflict check rather than a subset test. | |
1086 | ??? We could introduce -fvery-strict-aliasing when the language | |
1087 | does not allow decls to have a dynamic type that differs from their | |
1088 | static type. Then we can check | |
1089 | !alias_set_subset_of (base1_alias_set, base2_alias_set) instead. */ | |
dd277d48 | 1090 | if (base1_alias_set != base2_alias_set |
182cf5a9 | 1091 | && !alias_sets_conflict_p (base1_alias_set, base2_alias_set)) |
1092 | return false; | |
1093 | /* If the size of the access relevant for TBAA through the pointer | |
1094 | is bigger than the size of the decl we can't possibly access the | |
1095 | decl via that pointer. */ | |
1096 | if (DECL_SIZE (base2) && COMPLETE_TYPE_P (TREE_TYPE (ptrtype1)) | |
1097 | && TREE_CODE (DECL_SIZE (base2)) == INTEGER_CST | |
1098 | && TREE_CODE (TYPE_SIZE (TREE_TYPE (ptrtype1))) == INTEGER_CST | |
1099 | /* ??? This in turn may run afoul when a decl of type T which is | |
1100 | a member of union type U is accessed through a pointer to | |
1101 | type U and sizeof T is smaller than sizeof U. */ | |
1102 | && TREE_CODE (TREE_TYPE (ptrtype1)) != UNION_TYPE | |
1103 | && TREE_CODE (TREE_TYPE (ptrtype1)) != QUAL_UNION_TYPE | |
1104 | && tree_int_cst_lt (DECL_SIZE (base2), TYPE_SIZE (TREE_TYPE (ptrtype1)))) | |
dd277d48 | 1105 | return false; |
1106 | ||
061b1263 | 1107 | if (!ref2) |
1108 | return true; | |
1109 | ||
a07f6629 | 1110 | /* If the decl is accessed via a MEM_REF, reconstruct the base |
061b1263 | 1111 | we can use for TBAA and an appropriately adjusted offset. */ |
1112 | dbase2 = ref2; | |
1113 | while (handled_component_p (dbase2)) | |
1114 | dbase2 = TREE_OPERAND (dbase2, 0); | |
1115 | doffset1 = offset1; | |
1116 | doffset2 = offset2; | |
1117 | if (TREE_CODE (dbase2) == MEM_REF | |
1118 | || TREE_CODE (dbase2) == TARGET_MEM_REF) | |
1119 | { | |
1120 | double_int moff = mem_ref_offset (dbase2); | |
9a8b9e26 | 1121 | moff = moff.lshift (BITS_PER_UNIT == 8 ? 3 : exact_log2 (BITS_PER_UNIT)); |
cf8f0e63 | 1122 | if (moff.is_negative ()) |
1123 | doffset1 -= (-moff).low; | |
061b1263 | 1124 | else |
1125 | doffset2 -= moff.low; | |
1126 | } | |
1127 | ||
1128 | /* If either reference is view-converted, give up now. */ | |
1129 | if (same_type_for_tbaa (TREE_TYPE (base1), TREE_TYPE (ptrtype1)) != 1 | |
5ef4302d | 1130 | || same_type_for_tbaa (TREE_TYPE (dbase2), TREE_TYPE (base2)) != 1) |
061b1263 | 1131 | return true; |
1132 | ||
1133 | /* If both references are through the same type, they do not alias | |
1134 | if the accesses do not overlap. This does extra disambiguation | |
1135 | for mixed/pointer accesses but requires strict aliasing. | |
1136 | For MEM_REFs we require that the component-ref offset we computed | |
1137 | is relative to the start of the type which we ensure by | |
1138 | comparing rvalue and access type and disregarding the constant | |
1139 | pointer offset. */ | |
1140 | if ((TREE_CODE (base1) != TARGET_MEM_REF | |
1141 | || (!TMR_INDEX (base1) && !TMR_INDEX2 (base1))) | |
1142 | && same_type_for_tbaa (TREE_TYPE (base1), TREE_TYPE (dbase2)) == 1) | |
1143 | return ranges_overlap_p (doffset1, max_size1, doffset2, max_size2); | |
1144 | ||
f270d2a0 | 1145 | if (ref1 && ref2 |
1146 | && nonoverlapping_component_refs_p (ref1, ref2)) | |
1147 | return false; | |
1148 | ||
dd277d48 | 1149 | /* Do access-path based disambiguation. */ |
1150 | if (ref1 && ref2 | |
061b1263 | 1151 | && (handled_component_p (ref1) || handled_component_p (ref2))) |
0d2f7431 | 1152 | return aliasing_component_refs_p (ref1, |
ac30e3b2 | 1153 | ref1_alias_set, base1_alias_set, |
a42ce2cc | 1154 | offset1, max_size1, |
0d2f7431 | 1155 | ref2, |
ac30e3b2 | 1156 | ref2_alias_set, base2_alias_set, |
1157 | offset2, max_size2, true); | |
dd277d48 | 1158 | |
1159 | return true; | |
1160 | } | |
1161 | ||
1162 | /* Return true if two indirect references based on *PTR1 | |
077ad5ad | 1163 | and *PTR2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and |
1164 | [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. *PTR1 and *PTR2 have | |
dd277d48 | 1165 | the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1 |
1166 | in which case they are computed on-demand. REF1 and REF2 | |
1167 | if non-NULL are the complete memory reference trees. */ | |
1168 | ||
1169 | static bool | |
182cf5a9 | 1170 | indirect_refs_may_alias_p (tree ref1 ATTRIBUTE_UNUSED, tree base1, |
dd277d48 | 1171 | HOST_WIDE_INT offset1, HOST_WIDE_INT max_size1, |
ac30e3b2 | 1172 | alias_set_type ref1_alias_set, |
dd277d48 | 1173 | alias_set_type base1_alias_set, |
182cf5a9 | 1174 | tree ref2 ATTRIBUTE_UNUSED, tree base2, |
dd277d48 | 1175 | HOST_WIDE_INT offset2, HOST_WIDE_INT max_size2, |
ac30e3b2 | 1176 | alias_set_type ref2_alias_set, |
182cf5a9 | 1177 | alias_set_type base2_alias_set, bool tbaa_p) |
dd277d48 | 1178 | { |
9a14ba4f | 1179 | tree ptr1; |
1180 | tree ptr2; | |
182cf5a9 | 1181 | tree ptrtype1, ptrtype2; |
1182 | ||
2622064f | 1183 | gcc_checking_assert ((TREE_CODE (base1) == MEM_REF |
1184 | || TREE_CODE (base1) == TARGET_MEM_REF) | |
1185 | && (TREE_CODE (base2) == MEM_REF | |
1186 | || TREE_CODE (base2) == TARGET_MEM_REF)); | |
1187 | ||
28daba6f | 1188 | ptr1 = TREE_OPERAND (base1, 0); |
1189 | ptr2 = TREE_OPERAND (base2, 0); | |
9a14ba4f | 1190 | |
dd277d48 | 1191 | /* If both bases are based on pointers they cannot alias if they may not |
1192 | point to the same memory object or if they point to the same object | |
1193 | and the accesses do not overlap. */ | |
b5c3c805 | 1194 | if ((!cfun || gimple_in_ssa_p (cfun)) |
9a14ba4f | 1195 | && operand_equal_p (ptr1, ptr2, 0) |
1196 | && (((TREE_CODE (base1) != TARGET_MEM_REF | |
88be3999 | 1197 | || (!TMR_INDEX (base1) && !TMR_INDEX2 (base1))) |
9a14ba4f | 1198 | && (TREE_CODE (base2) != TARGET_MEM_REF |
88be3999 | 1199 | || (!TMR_INDEX (base2) && !TMR_INDEX2 (base2)))) |
9a14ba4f | 1200 | || (TREE_CODE (base1) == TARGET_MEM_REF |
1201 | && TREE_CODE (base2) == TARGET_MEM_REF | |
1202 | && (TMR_STEP (base1) == TMR_STEP (base2) | |
1203 | || (TMR_STEP (base1) && TMR_STEP (base2) | |
1204 | && operand_equal_p (TMR_STEP (base1), | |
1205 | TMR_STEP (base2), 0))) | |
88be3999 | 1206 | && (TMR_INDEX (base1) == TMR_INDEX (base2) |
1207 | || (TMR_INDEX (base1) && TMR_INDEX (base2) | |
1208 | && operand_equal_p (TMR_INDEX (base1), | |
1209 | TMR_INDEX (base2), 0))) | |
1210 | && (TMR_INDEX2 (base1) == TMR_INDEX2 (base2) | |
1211 | || (TMR_INDEX2 (base1) && TMR_INDEX2 (base2) | |
1212 | && operand_equal_p (TMR_INDEX2 (base1), | |
1213 | TMR_INDEX2 (base2), 0)))))) | |
182cf5a9 | 1214 | { |
2622064f | 1215 | double_int moff; |
7749ee1c | 1216 | /* The offset embedded in MEM_REFs can be negative. Bias them |
1217 | so that the resulting offset adjustment is positive. */ | |
2622064f | 1218 | moff = mem_ref_offset (base1); |
9a8b9e26 | 1219 | moff = moff.lshift (BITS_PER_UNIT == 8 ? 3 : exact_log2 (BITS_PER_UNIT)); |
cf8f0e63 | 1220 | if (moff.is_negative ()) |
1221 | offset2 += (-moff).low; | |
2622064f | 1222 | else |
1223 | offset1 += moff.low; | |
1224 | moff = mem_ref_offset (base2); | |
9a8b9e26 | 1225 | moff = moff.lshift (BITS_PER_UNIT == 8 ? 3 : exact_log2 (BITS_PER_UNIT)); |
cf8f0e63 | 1226 | if (moff.is_negative ()) |
1227 | offset1 += (-moff).low; | |
2622064f | 1228 | else |
1229 | offset2 += moff.low; | |
182cf5a9 | 1230 | return ranges_overlap_p (offset1, max_size1, offset2, max_size2); |
1231 | } | |
dd277d48 | 1232 | if (!ptr_derefs_may_alias_p (ptr1, ptr2)) |
1233 | return false; | |
1234 | ||
1235 | /* Disambiguations that rely on strict aliasing rules follow. */ | |
182cf5a9 | 1236 | if (!flag_strict_aliasing || !tbaa_p) |
dd277d48 | 1237 | return true; |
1238 | ||
2622064f | 1239 | ptrtype1 = TREE_TYPE (TREE_OPERAND (base1, 1)); |
1240 | ptrtype2 = TREE_TYPE (TREE_OPERAND (base2, 1)); | |
182cf5a9 | 1241 | |
dd277d48 | 1242 | /* If the alias set for a pointer access is zero all bets are off. */ |
1243 | if (base1_alias_set == -1) | |
182cf5a9 | 1244 | base1_alias_set = get_deref_alias_set (ptrtype1); |
dd277d48 | 1245 | if (base1_alias_set == 0) |
1246 | return true; | |
1247 | if (base2_alias_set == -1) | |
182cf5a9 | 1248 | base2_alias_set = get_deref_alias_set (ptrtype2); |
dd277d48 | 1249 | if (base2_alias_set == 0) |
1250 | return true; | |
1251 | ||
1252 | /* If both references are through the same type, they do not alias | |
1253 | if the accesses do not overlap. This does extra disambiguation | |
1254 | for mixed/pointer accesses but requires strict aliasing. */ | |
9c455d1e | 1255 | if ((TREE_CODE (base1) != TARGET_MEM_REF |
1256 | || (!TMR_INDEX (base1) && !TMR_INDEX2 (base1))) | |
1257 | && (TREE_CODE (base2) != TARGET_MEM_REF | |
1258 | || (!TMR_INDEX (base2) && !TMR_INDEX2 (base2))) | |
1259 | && same_type_for_tbaa (TREE_TYPE (base1), TREE_TYPE (ptrtype1)) == 1 | |
1260 | && same_type_for_tbaa (TREE_TYPE (base2), TREE_TYPE (ptrtype2)) == 1 | |
182cf5a9 | 1261 | && same_type_for_tbaa (TREE_TYPE (ptrtype1), |
1262 | TREE_TYPE (ptrtype2)) == 1) | |
dd277d48 | 1263 | return ranges_overlap_p (offset1, max_size1, offset2, max_size2); |
1264 | ||
1265 | /* Do type-based disambiguation. */ | |
1266 | if (base1_alias_set != base2_alias_set | |
1267 | && !alias_sets_conflict_p (base1_alias_set, base2_alias_set)) | |
1268 | return false; | |
1269 | ||
f270d2a0 | 1270 | /* If either reference is view-converted, give up now. */ |
1271 | if (same_type_for_tbaa (TREE_TYPE (base1), TREE_TYPE (ptrtype1)) != 1 | |
1272 | || same_type_for_tbaa (TREE_TYPE (base2), TREE_TYPE (ptrtype2)) != 1) | |
1273 | return true; | |
1274 | ||
1275 | if (ref1 && ref2 | |
1276 | && nonoverlapping_component_refs_p (ref1, ref2)) | |
1277 | return false; | |
1278 | ||
dd277d48 | 1279 | /* Do access-path based disambiguation. */ |
1280 | if (ref1 && ref2 | |
f270d2a0 | 1281 | && (handled_component_p (ref1) || handled_component_p (ref2))) |
0d2f7431 | 1282 | return aliasing_component_refs_p (ref1, |
ac30e3b2 | 1283 | ref1_alias_set, base1_alias_set, |
a42ce2cc | 1284 | offset1, max_size1, |
0d2f7431 | 1285 | ref2, |
ac30e3b2 | 1286 | ref2_alias_set, base2_alias_set, |
1287 | offset2, max_size2, false); | |
dd277d48 | 1288 | |
1289 | return true; | |
1290 | } | |
1291 | ||
1292 | /* Return true, if the two memory references REF1 and REF2 may alias. */ | |
1293 | ||
3a443843 | 1294 | bool |
3918bd18 | 1295 | refs_may_alias_p_1 (ao_ref *ref1, ao_ref *ref2, bool tbaa_p) |
dd277d48 | 1296 | { |
1297 | tree base1, base2; | |
1298 | HOST_WIDE_INT offset1 = 0, offset2 = 0; | |
dd277d48 | 1299 | HOST_WIDE_INT max_size1 = -1, max_size2 = -1; |
1300 | bool var1_p, var2_p, ind1_p, ind2_p; | |
1301 | ||
c78d5cec | 1302 | gcc_checking_assert ((!ref1->ref |
8e7c2b9c | 1303 | || TREE_CODE (ref1->ref) == SSA_NAME |
c78d5cec | 1304 | || DECL_P (ref1->ref) |
2760c0e3 | 1305 | || TREE_CODE (ref1->ref) == STRING_CST |
c78d5cec | 1306 | || handled_component_p (ref1->ref) |
182cf5a9 | 1307 | || TREE_CODE (ref1->ref) == MEM_REF |
c78d5cec | 1308 | || TREE_CODE (ref1->ref) == TARGET_MEM_REF) |
1309 | && (!ref2->ref | |
8e7c2b9c | 1310 | || TREE_CODE (ref2->ref) == SSA_NAME |
c78d5cec | 1311 | || DECL_P (ref2->ref) |
2760c0e3 | 1312 | || TREE_CODE (ref2->ref) == STRING_CST |
c78d5cec | 1313 | || handled_component_p (ref2->ref) |
182cf5a9 | 1314 | || TREE_CODE (ref2->ref) == MEM_REF |
c78d5cec | 1315 | || TREE_CODE (ref2->ref) == TARGET_MEM_REF)); |
dd277d48 | 1316 | |
dd277d48 | 1317 | /* Decompose the references into their base objects and the access. */ |
3918bd18 | 1318 | base1 = ao_ref_base (ref1); |
1319 | offset1 = ref1->offset; | |
3918bd18 | 1320 | max_size1 = ref1->max_size; |
1321 | base2 = ao_ref_base (ref2); | |
1322 | offset2 = ref2->offset; | |
3918bd18 | 1323 | max_size2 = ref2->max_size; |
dd277d48 | 1324 | |
1325 | /* We can end up with registers or constants as bases for example from | |
1326 | *D.1663_44 = VIEW_CONVERT_EXPR<struct DB_LSN>(__tmp$B0F64_59); | |
1327 | which is seen as a struct copy. */ | |
1328 | if (TREE_CODE (base1) == SSA_NAME | |
119147d1 | 1329 | || TREE_CODE (base1) == CONST_DECL |
66b86a74 | 1330 | || TREE_CODE (base1) == CONSTRUCTOR |
1331 | || TREE_CODE (base1) == ADDR_EXPR | |
1332 | || CONSTANT_CLASS_P (base1) | |
1333 | || TREE_CODE (base2) == SSA_NAME | |
119147d1 | 1334 | || TREE_CODE (base2) == CONST_DECL |
66b86a74 | 1335 | || TREE_CODE (base2) == CONSTRUCTOR |
1336 | || TREE_CODE (base2) == ADDR_EXPR | |
1337 | || CONSTANT_CLASS_P (base2)) | |
dd277d48 | 1338 | return false; |
1339 | ||
04ec15fa | 1340 | /* We can end up referring to code via function and label decls. |
c78d5cec | 1341 | As we likely do not properly track code aliases conservatively |
1342 | bail out. */ | |
ceefbccc | 1343 | if (TREE_CODE (base1) == FUNCTION_DECL |
c78d5cec | 1344 | || TREE_CODE (base1) == LABEL_DECL |
66b86a74 | 1345 | || TREE_CODE (base2) == FUNCTION_DECL |
c78d5cec | 1346 | || TREE_CODE (base2) == LABEL_DECL) |
ceefbccc | 1347 | return true; |
1348 | ||
3787db52 | 1349 | /* Two volatile accesses always conflict. */ |
1350 | if (ref1->volatile_p | |
1351 | && ref2->volatile_p) | |
1352 | return true; | |
1353 | ||
090a8c65 | 1354 | /* Defer to simple offset based disambiguation if we have |
1355 | references based on two decls. Do this before defering to | |
1356 | TBAA to handle must-alias cases in conformance with the | |
1357 | GCC extension of allowing type-punning through unions. */ | |
2622064f | 1358 | var1_p = DECL_P (base1); |
1359 | var2_p = DECL_P (base2); | |
dd277d48 | 1360 | if (var1_p && var2_p) |
740a2cb6 | 1361 | return decl_refs_may_alias_p (ref1->ref, base1, offset1, max_size1, |
1362 | ref2->ref, base2, offset2, max_size2); | |
090a8c65 | 1363 | |
2622064f | 1364 | ind1_p = (TREE_CODE (base1) == MEM_REF |
1365 | || TREE_CODE (base1) == TARGET_MEM_REF); | |
1366 | ind2_p = (TREE_CODE (base2) == MEM_REF | |
1367 | || TREE_CODE (base2) == TARGET_MEM_REF); | |
182cf5a9 | 1368 | |
67817f0f | 1369 | /* Canonicalize the pointer-vs-decl case. */ |
1370 | if (ind1_p && var2_p) | |
1371 | { | |
1372 | HOST_WIDE_INT tmp1; | |
1373 | tree tmp2; | |
1374 | ao_ref *tmp3; | |
1375 | tmp1 = offset1; offset1 = offset2; offset2 = tmp1; | |
1376 | tmp1 = max_size1; max_size1 = max_size2; max_size2 = tmp1; | |
1377 | tmp2 = base1; base1 = base2; base2 = tmp2; | |
1378 | tmp3 = ref1; ref1 = ref2; ref2 = tmp3; | |
1379 | var1_p = true; | |
1380 | ind1_p = false; | |
1381 | var2_p = false; | |
1382 | ind2_p = true; | |
1383 | } | |
1384 | ||
090a8c65 | 1385 | /* First defer to TBAA if possible. */ |
2a3ebafa | 1386 | if (tbaa_p |
1387 | && flag_strict_aliasing | |
3918bd18 | 1388 | && !alias_sets_conflict_p (ao_ref_alias_set (ref1), |
1389 | ao_ref_alias_set (ref2))) | |
090a8c65 | 1390 | return false; |
1391 | ||
090a8c65 | 1392 | /* Dispatch to the pointer-vs-decl or pointer-vs-pointer disambiguators. */ |
090a8c65 | 1393 | if (var1_p && ind2_p) |
182cf5a9 | 1394 | return indirect_ref_may_alias_decl_p (ref2->ref, base2, |
ac30e3b2 | 1395 | offset2, max_size2, |
182cf5a9 | 1396 | ao_ref_alias_set (ref2), -1, |
3918bd18 | 1397 | ref1->ref, base1, |
ac30e3b2 | 1398 | offset1, max_size1, |
182cf5a9 | 1399 | ao_ref_alias_set (ref1), |
1400 | ao_ref_base_alias_set (ref1), | |
1401 | tbaa_p); | |
dd277d48 | 1402 | else if (ind1_p && ind2_p) |
182cf5a9 | 1403 | return indirect_refs_may_alias_p (ref1->ref, base1, |
ac30e3b2 | 1404 | offset1, max_size1, |
182cf5a9 | 1405 | ao_ref_alias_set (ref1), -1, |
1406 | ref2->ref, base2, | |
ac30e3b2 | 1407 | offset2, max_size2, |
182cf5a9 | 1408 | ao_ref_alias_set (ref2), -1, |
1409 | tbaa_p); | |
dd277d48 | 1410 | |
9c01641d | 1411 | /* We really do not want to end up here, but returning true is safe. */ |
1412 | #ifdef ENABLE_CHECKING | |
dd277d48 | 1413 | gcc_unreachable (); |
9c01641d | 1414 | #else |
1415 | return true; | |
1416 | #endif | |
dd277d48 | 1417 | } |
1418 | ||
1419 | bool | |
1420 | refs_may_alias_p (tree ref1, tree ref2) | |
1421 | { | |
3918bd18 | 1422 | ao_ref r1, r2; |
1423 | bool res; | |
1424 | ao_ref_init (&r1, ref1); | |
1425 | ao_ref_init (&r2, ref2); | |
1426 | res = refs_may_alias_p_1 (&r1, &r2, true); | |
dd277d48 | 1427 | if (res) |
1428 | ++alias_stats.refs_may_alias_p_may_alias; | |
1429 | else | |
1430 | ++alias_stats.refs_may_alias_p_no_alias; | |
1431 | return res; | |
1432 | } | |
1433 | ||
2a3ebafa | 1434 | /* Returns true if there is a anti-dependence for the STORE that |
1435 | executes after the LOAD. */ | |
1436 | ||
1437 | bool | |
1438 | refs_anti_dependent_p (tree load, tree store) | |
1439 | { | |
3918bd18 | 1440 | ao_ref r1, r2; |
1441 | ao_ref_init (&r1, load); | |
1442 | ao_ref_init (&r2, store); | |
1443 | return refs_may_alias_p_1 (&r1, &r2, false); | |
2a3ebafa | 1444 | } |
1445 | ||
1446 | /* Returns true if there is a output dependence for the stores | |
1447 | STORE1 and STORE2. */ | |
1448 | ||
1449 | bool | |
1450 | refs_output_dependent_p (tree store1, tree store2) | |
1451 | { | |
3918bd18 | 1452 | ao_ref r1, r2; |
1453 | ao_ref_init (&r1, store1); | |
1454 | ao_ref_init (&r2, store2); | |
1455 | return refs_may_alias_p_1 (&r1, &r2, false); | |
2a3ebafa | 1456 | } |
dd277d48 | 1457 | |
1458 | /* If the call CALL may use the memory reference REF return true, | |
1459 | otherwise return false. */ | |
1460 | ||
1461 | static bool | |
134899ac | 1462 | ref_maybe_used_by_call_p_1 (gimple call, ao_ref *ref) |
dd277d48 | 1463 | { |
047fdd47 | 1464 | tree base, callee; |
dd277d48 | 1465 | unsigned i; |
1466 | int flags = gimple_call_flags (call); | |
1467 | ||
1468 | /* Const functions without a static chain do not implicitly use memory. */ | |
1469 | if (!gimple_call_chain (call) | |
1470 | && (flags & (ECF_CONST|ECF_NOVOPS))) | |
1471 | goto process_args; | |
1472 | ||
134899ac | 1473 | base = ao_ref_base (ref); |
917f08fa | 1474 | if (!base) |
dd277d48 | 1475 | return true; |
1476 | ||
3787db52 | 1477 | /* A call that is not without side-effects might involve volatile |
1478 | accesses and thus conflicts with all other volatile accesses. */ | |
1479 | if (ref->volatile_p) | |
1480 | return true; | |
1481 | ||
09347e88 | 1482 | /* If the reference is based on a decl that is not aliased the call |
1483 | cannot possibly use it. */ | |
1484 | if (DECL_P (base) | |
1485 | && !may_be_aliased (base) | |
7f7f16d4 | 1486 | /* But local statics can be used through recursion. */ |
1487 | && !is_global_var (base)) | |
09347e88 | 1488 | goto process_args; |
1489 | ||
047fdd47 | 1490 | callee = gimple_call_fndecl (call); |
1491 | ||
1492 | /* Handle those builtin functions explicitly that do not act as | |
1493 | escape points. See tree-ssa-structalias.c:find_func_aliases | |
1494 | for the list of builtins we might need to handle here. */ | |
1495 | if (callee != NULL_TREE | |
1496 | && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL) | |
1497 | switch (DECL_FUNCTION_CODE (callee)) | |
1498 | { | |
77efe819 | 1499 | /* All the following functions read memory pointed to by |
1500 | their second argument. strcat/strncat additionally | |
1501 | reads memory pointed to by the first argument. */ | |
1502 | case BUILT_IN_STRCAT: | |
1503 | case BUILT_IN_STRNCAT: | |
1504 | { | |
1505 | ao_ref dref; | |
1506 | ao_ref_init_from_ptr_and_size (&dref, | |
1507 | gimple_call_arg (call, 0), | |
1508 | NULL_TREE); | |
1509 | if (refs_may_alias_p_1 (&dref, ref, false)) | |
1510 | return true; | |
1511 | } | |
1512 | /* FALLTHRU */ | |
047fdd47 | 1513 | case BUILT_IN_STRCPY: |
1514 | case BUILT_IN_STRNCPY: | |
047fdd47 | 1515 | case BUILT_IN_MEMCPY: |
1516 | case BUILT_IN_MEMMOVE: | |
1517 | case BUILT_IN_MEMPCPY: | |
1518 | case BUILT_IN_STPCPY: | |
1519 | case BUILT_IN_STPNCPY: | |
4c0315d0 | 1520 | case BUILT_IN_TM_MEMCPY: |
1521 | case BUILT_IN_TM_MEMMOVE: | |
047fdd47 | 1522 | { |
134899ac | 1523 | ao_ref dref; |
1524 | tree size = NULL_TREE; | |
1525 | if (gimple_call_num_args (call) == 3) | |
1526 | size = gimple_call_arg (call, 2); | |
1527 | ao_ref_init_from_ptr_and_size (&dref, | |
1528 | gimple_call_arg (call, 1), | |
1529 | size); | |
1530 | return refs_may_alias_p_1 (&dref, ref, false); | |
047fdd47 | 1531 | } |
77efe819 | 1532 | case BUILT_IN_STRCAT_CHK: |
1533 | case BUILT_IN_STRNCAT_CHK: | |
1534 | { | |
1535 | ao_ref dref; | |
1536 | ao_ref_init_from_ptr_and_size (&dref, | |
1537 | gimple_call_arg (call, 0), | |
1538 | NULL_TREE); | |
1539 | if (refs_may_alias_p_1 (&dref, ref, false)) | |
1540 | return true; | |
1541 | } | |
1542 | /* FALLTHRU */ | |
939514e9 | 1543 | case BUILT_IN_STRCPY_CHK: |
1544 | case BUILT_IN_STRNCPY_CHK: | |
1545 | case BUILT_IN_MEMCPY_CHK: | |
1546 | case BUILT_IN_MEMMOVE_CHK: | |
1547 | case BUILT_IN_MEMPCPY_CHK: | |
1548 | case BUILT_IN_STPCPY_CHK: | |
1063acde | 1549 | case BUILT_IN_STPNCPY_CHK: |
939514e9 | 1550 | { |
1551 | ao_ref dref; | |
1552 | tree size = NULL_TREE; | |
1553 | if (gimple_call_num_args (call) == 4) | |
1554 | size = gimple_call_arg (call, 2); | |
1555 | ao_ref_init_from_ptr_and_size (&dref, | |
1556 | gimple_call_arg (call, 1), | |
1557 | size); | |
1558 | return refs_may_alias_p_1 (&dref, ref, false); | |
1559 | } | |
119147d1 | 1560 | case BUILT_IN_BCOPY: |
1561 | { | |
1562 | ao_ref dref; | |
1563 | tree size = gimple_call_arg (call, 2); | |
1564 | ao_ref_init_from_ptr_and_size (&dref, | |
1565 | gimple_call_arg (call, 0), | |
1566 | size); | |
1567 | return refs_may_alias_p_1 (&dref, ref, false); | |
1568 | } | |
4c0315d0 | 1569 | |
1570 | /* The following functions read memory pointed to by their | |
1571 | first argument. */ | |
1572 | CASE_BUILT_IN_TM_LOAD (1): | |
1573 | CASE_BUILT_IN_TM_LOAD (2): | |
1574 | CASE_BUILT_IN_TM_LOAD (4): | |
1575 | CASE_BUILT_IN_TM_LOAD (8): | |
1576 | CASE_BUILT_IN_TM_LOAD (FLOAT): | |
1577 | CASE_BUILT_IN_TM_LOAD (DOUBLE): | |
1578 | CASE_BUILT_IN_TM_LOAD (LDOUBLE): | |
1579 | CASE_BUILT_IN_TM_LOAD (M64): | |
1580 | CASE_BUILT_IN_TM_LOAD (M128): | |
1581 | CASE_BUILT_IN_TM_LOAD (M256): | |
1582 | case BUILT_IN_TM_LOG: | |
1583 | case BUILT_IN_TM_LOG_1: | |
1584 | case BUILT_IN_TM_LOG_2: | |
1585 | case BUILT_IN_TM_LOG_4: | |
1586 | case BUILT_IN_TM_LOG_8: | |
1587 | case BUILT_IN_TM_LOG_FLOAT: | |
1588 | case BUILT_IN_TM_LOG_DOUBLE: | |
1589 | case BUILT_IN_TM_LOG_LDOUBLE: | |
1590 | case BUILT_IN_TM_LOG_M64: | |
1591 | case BUILT_IN_TM_LOG_M128: | |
1592 | case BUILT_IN_TM_LOG_M256: | |
1593 | return ptr_deref_may_alias_ref_p_1 (gimple_call_arg (call, 0), ref); | |
1594 | ||
77efe819 | 1595 | /* These read memory pointed to by the first argument. */ |
1596 | case BUILT_IN_STRDUP: | |
1597 | case BUILT_IN_STRNDUP: | |
1598 | { | |
1599 | ao_ref dref; | |
1600 | tree size = NULL_TREE; | |
1601 | if (gimple_call_num_args (call) == 2) | |
1602 | size = gimple_call_arg (call, 1); | |
1603 | ao_ref_init_from_ptr_and_size (&dref, | |
1604 | gimple_call_arg (call, 0), | |
1605 | size); | |
1606 | return refs_may_alias_p_1 (&dref, ref, false); | |
1607 | } | |
4953672f | 1608 | /* These read memory pointed to by the first argument. */ |
1609 | case BUILT_IN_INDEX: | |
1610 | case BUILT_IN_STRCHR: | |
1611 | case BUILT_IN_STRRCHR: | |
1612 | { | |
1613 | ao_ref dref; | |
1614 | ao_ref_init_from_ptr_and_size (&dref, | |
1615 | gimple_call_arg (call, 0), | |
1616 | NULL_TREE); | |
1617 | return refs_may_alias_p_1 (&dref, ref, false); | |
1618 | } | |
1619 | /* These read memory pointed to by the first argument with size | |
1620 | in the third argument. */ | |
1621 | case BUILT_IN_MEMCHR: | |
1622 | { | |
1623 | ao_ref dref; | |
1624 | ao_ref_init_from_ptr_and_size (&dref, | |
1625 | gimple_call_arg (call, 0), | |
1626 | gimple_call_arg (call, 2)); | |
1627 | return refs_may_alias_p_1 (&dref, ref, false); | |
1628 | } | |
1629 | /* These read memory pointed to by the first and second arguments. */ | |
1630 | case BUILT_IN_STRSTR: | |
1631 | case BUILT_IN_STRPBRK: | |
1632 | { | |
1633 | ao_ref dref; | |
1634 | ao_ref_init_from_ptr_and_size (&dref, | |
1635 | gimple_call_arg (call, 0), | |
1636 | NULL_TREE); | |
1637 | if (refs_may_alias_p_1 (&dref, ref, false)) | |
1638 | return true; | |
1639 | ao_ref_init_from_ptr_and_size (&dref, | |
1640 | gimple_call_arg (call, 1), | |
1641 | NULL_TREE); | |
1642 | return refs_may_alias_p_1 (&dref, ref, false); | |
1643 | } | |
1644 | ||
09d9c774 | 1645 | /* The following builtins do not read from memory. */ |
1646 | case BUILT_IN_FREE: | |
0d3ca08e | 1647 | case BUILT_IN_MALLOC: |
be2c7f8f | 1648 | case BUILT_IN_POSIX_MEMALIGN: |
4ef43bbd | 1649 | case BUILT_IN_CALLOC: |
ca793672 | 1650 | case BUILT_IN_ALLOCA: |
581bf1c2 | 1651 | case BUILT_IN_ALLOCA_WITH_ALIGN: |
ca793672 | 1652 | case BUILT_IN_STACK_SAVE: |
1653 | case BUILT_IN_STACK_RESTORE: | |
09d9c774 | 1654 | case BUILT_IN_MEMSET: |
4c0315d0 | 1655 | case BUILT_IN_TM_MEMSET: |
939514e9 | 1656 | case BUILT_IN_MEMSET_CHK: |
09d9c774 | 1657 | case BUILT_IN_FREXP: |
1658 | case BUILT_IN_FREXPF: | |
1659 | case BUILT_IN_FREXPL: | |
1660 | case BUILT_IN_GAMMA_R: | |
1661 | case BUILT_IN_GAMMAF_R: | |
1662 | case BUILT_IN_GAMMAL_R: | |
1663 | case BUILT_IN_LGAMMA_R: | |
1664 | case BUILT_IN_LGAMMAF_R: | |
1665 | case BUILT_IN_LGAMMAL_R: | |
1666 | case BUILT_IN_MODF: | |
1667 | case BUILT_IN_MODFF: | |
1668 | case BUILT_IN_MODFL: | |
1669 | case BUILT_IN_REMQUO: | |
1670 | case BUILT_IN_REMQUOF: | |
1671 | case BUILT_IN_REMQUOL: | |
1672 | case BUILT_IN_SINCOS: | |
1673 | case BUILT_IN_SINCOSF: | |
1674 | case BUILT_IN_SINCOSL: | |
fca0886c | 1675 | case BUILT_IN_ASSUME_ALIGNED: |
9d17b4a8 | 1676 | case BUILT_IN_VA_END: |
09d9c774 | 1677 | return false; |
a44814b9 | 1678 | /* __sync_* builtins and some OpenMP builtins act as threading |
1679 | barriers. */ | |
1680 | #undef DEF_SYNC_BUILTIN | |
1681 | #define DEF_SYNC_BUILTIN(ENUM, NAME, TYPE, ATTRS) case ENUM: | |
1682 | #include "sync-builtins.def" | |
1683 | #undef DEF_SYNC_BUILTIN | |
1684 | case BUILT_IN_GOMP_ATOMIC_START: | |
1685 | case BUILT_IN_GOMP_ATOMIC_END: | |
1686 | case BUILT_IN_GOMP_BARRIER: | |
bc7bff74 | 1687 | case BUILT_IN_GOMP_BARRIER_CANCEL: |
a44814b9 | 1688 | case BUILT_IN_GOMP_TASKWAIT: |
bc7bff74 | 1689 | case BUILT_IN_GOMP_TASKGROUP_END: |
a44814b9 | 1690 | case BUILT_IN_GOMP_CRITICAL_START: |
1691 | case BUILT_IN_GOMP_CRITICAL_END: | |
1692 | case BUILT_IN_GOMP_CRITICAL_NAME_START: | |
1693 | case BUILT_IN_GOMP_CRITICAL_NAME_END: | |
1694 | case BUILT_IN_GOMP_LOOP_END: | |
bc7bff74 | 1695 | case BUILT_IN_GOMP_LOOP_END_CANCEL: |
a44814b9 | 1696 | case BUILT_IN_GOMP_ORDERED_START: |
1697 | case BUILT_IN_GOMP_ORDERED_END: | |
a44814b9 | 1698 | case BUILT_IN_GOMP_SECTIONS_END: |
bc7bff74 | 1699 | case BUILT_IN_GOMP_SECTIONS_END_CANCEL: |
a44814b9 | 1700 | case BUILT_IN_GOMP_SINGLE_COPY_START: |
1701 | case BUILT_IN_GOMP_SINGLE_COPY_END: | |
1702 | return true; | |
09d9c774 | 1703 | |
047fdd47 | 1704 | default: |
1705 | /* Fallthru to general call handling. */; | |
1706 | } | |
1707 | ||
dd277d48 | 1708 | /* Check if base is a global static variable that is not read |
1709 | by the function. */ | |
924de091 | 1710 | if (callee != NULL_TREE |
1711 | && TREE_CODE (base) == VAR_DECL | |
d97be713 | 1712 | && TREE_STATIC (base)) |
4ee9c684 | 1713 | { |
924de091 | 1714 | struct cgraph_node *node = cgraph_get_node (callee); |
dd277d48 | 1715 | bitmap not_read; |
1716 | ||
924de091 | 1717 | /* FIXME: Callee can be an OMP builtin that does not have a call graph |
1718 | node yet. We should enforce that there are nodes for all decls in the | |
1719 | IL and remove this check instead. */ | |
1720 | if (node | |
1721 | && (not_read = ipa_reference_get_not_read_global (node)) | |
dd277d48 | 1722 | && bitmap_bit_p (not_read, DECL_UID (base))) |
1723 | goto process_args; | |
4ee9c684 | 1724 | } |
1725 | ||
cb245216 | 1726 | /* Check if the base variable is call-used. */ |
1727 | if (DECL_P (base)) | |
4ee9c684 | 1728 | { |
cb245216 | 1729 | if (pt_solution_includes (gimple_call_use_set (call), base)) |
dd277d48 | 1730 | return true; |
1731 | } | |
2622064f | 1732 | else if ((TREE_CODE (base) == MEM_REF |
1733 | || TREE_CODE (base) == TARGET_MEM_REF) | |
cb245216 | 1734 | && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME) |
dd277d48 | 1735 | { |
cb245216 | 1736 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0)); |
1737 | if (!pi) | |
1738 | return true; | |
917f08fa | 1739 | |
cb245216 | 1740 | if (pt_solutions_intersect (gimple_call_use_set (call), &pi->pt)) |
dd277d48 | 1741 | return true; |
1742 | } | |
cb245216 | 1743 | else |
1744 | return true; | |
dd277d48 | 1745 | |
1746 | /* Inspect call arguments for passed-by-value aliases. */ | |
1747 | process_args: | |
1748 | for (i = 0; i < gimple_call_num_args (call); ++i) | |
1749 | { | |
1750 | tree op = gimple_call_arg (call, i); | |
8ce86007 | 1751 | int flags = gimple_call_arg_flags (call, i); |
1752 | ||
1753 | if (flags & EAF_UNUSED) | |
1754 | continue; | |
dd277d48 | 1755 | |
dd277d48 | 1756 | if (TREE_CODE (op) == WITH_SIZE_EXPR) |
1757 | op = TREE_OPERAND (op, 0); | |
4ee9c684 | 1758 | |
dd277d48 | 1759 | if (TREE_CODE (op) != SSA_NAME |
134899ac | 1760 | && !is_gimple_min_invariant (op)) |
1761 | { | |
1762 | ao_ref r; | |
1763 | ao_ref_init (&r, op); | |
1764 | if (refs_may_alias_p_1 (&r, ref, true)) | |
1765 | return true; | |
1766 | } | |
4ee9c684 | 1767 | } |
1768 | ||
dd277d48 | 1769 | return false; |
1770 | } | |
1771 | ||
1772 | static bool | |
1773 | ref_maybe_used_by_call_p (gimple call, tree ref) | |
1774 | { | |
134899ac | 1775 | ao_ref r; |
1776 | bool res; | |
1777 | ao_ref_init (&r, ref); | |
1778 | res = ref_maybe_used_by_call_p_1 (call, &r); | |
dd277d48 | 1779 | if (res) |
1780 | ++alias_stats.ref_maybe_used_by_call_p_may_alias; | |
1781 | else | |
1782 | ++alias_stats.ref_maybe_used_by_call_p_no_alias; | |
1783 | return res; | |
4ee9c684 | 1784 | } |
1785 | ||
1786 | ||
dd277d48 | 1787 | /* If the statement STMT may use the memory reference REF return |
1788 | true, otherwise return false. */ | |
4ee9c684 | 1789 | |
dd277d48 | 1790 | bool |
1791 | ref_maybe_used_by_stmt_p (gimple stmt, tree ref) | |
4ee9c684 | 1792 | { |
dd277d48 | 1793 | if (is_gimple_assign (stmt)) |
1794 | { | |
1795 | tree rhs; | |
1796 | ||
1797 | /* All memory assign statements are single. */ | |
1798 | if (!gimple_assign_single_p (stmt)) | |
1799 | return false; | |
1800 | ||
1801 | rhs = gimple_assign_rhs1 (stmt); | |
1802 | if (is_gimple_reg (rhs) | |
1803 | || is_gimple_min_invariant (rhs) | |
1804 | || gimple_assign_rhs_code (stmt) == CONSTRUCTOR) | |
1805 | return false; | |
1806 | ||
1807 | return refs_may_alias_p (rhs, ref); | |
1808 | } | |
1809 | else if (is_gimple_call (stmt)) | |
1810 | return ref_maybe_used_by_call_p (stmt, ref); | |
91234829 | 1811 | else if (gimple_code (stmt) == GIMPLE_RETURN) |
1812 | { | |
1813 | tree retval = gimple_return_retval (stmt); | |
1814 | tree base; | |
1815 | if (retval | |
1816 | && TREE_CODE (retval) != SSA_NAME | |
1817 | && !is_gimple_min_invariant (retval) | |
1818 | && refs_may_alias_p (retval, ref)) | |
1819 | return true; | |
1820 | /* If ref escapes the function then the return acts as a use. */ | |
1821 | base = get_base_address (ref); | |
1822 | if (!base) | |
1823 | ; | |
1824 | else if (DECL_P (base)) | |
1825 | return is_global_var (base); | |
1826 | else if (TREE_CODE (base) == MEM_REF | |
1827 | || TREE_CODE (base) == TARGET_MEM_REF) | |
1828 | return ptr_deref_may_alias_global_p (TREE_OPERAND (base, 0)); | |
1829 | return false; | |
1830 | } | |
dd277d48 | 1831 | |
1832 | return true; | |
4ee9c684 | 1833 | } |
1834 | ||
dd277d48 | 1835 | /* If the call in statement CALL may clobber the memory reference REF |
1836 | return true, otherwise return false. */ | |
4ee9c684 | 1837 | |
dd277d48 | 1838 | static bool |
3918bd18 | 1839 | call_may_clobber_ref_p_1 (gimple call, ao_ref *ref) |
4ee9c684 | 1840 | { |
7f7f16d4 | 1841 | tree base; |
047fdd47 | 1842 | tree callee; |
dd277d48 | 1843 | |
1844 | /* If the call is pure or const it cannot clobber anything. */ | |
1845 | if (gimple_call_flags (call) | |
1846 | & (ECF_PURE|ECF_CONST|ECF_LOOPING_CONST_OR_PURE|ECF_NOVOPS)) | |
1847 | return false; | |
1848 | ||
3918bd18 | 1849 | base = ao_ref_base (ref); |
dd277d48 | 1850 | if (!base) |
1851 | return true; | |
1852 | ||
1853 | if (TREE_CODE (base) == SSA_NAME | |
1854 | || CONSTANT_CLASS_P (base)) | |
1855 | return false; | |
1856 | ||
3787db52 | 1857 | /* A call that is not without side-effects might involve volatile |
1858 | accesses and thus conflicts with all other volatile accesses. */ | |
1859 | if (ref->volatile_p) | |
1860 | return true; | |
1861 | ||
09347e88 | 1862 | /* If the reference is based on a decl that is not aliased the call |
1863 | cannot possibly clobber it. */ | |
1864 | if (DECL_P (base) | |
1865 | && !may_be_aliased (base) | |
7f7f16d4 | 1866 | /* But local non-readonly statics can be modified through recursion |
1867 | or the call may implement a threading barrier which we must | |
1868 | treat as may-def. */ | |
09347e88 | 1869 | && (TREE_READONLY (base) |
7f7f16d4 | 1870 | || !is_global_var (base))) |
09347e88 | 1871 | return false; |
1872 | ||
047fdd47 | 1873 | callee = gimple_call_fndecl (call); |
1874 | ||
1875 | /* Handle those builtin functions explicitly that do not act as | |
1876 | escape points. See tree-ssa-structalias.c:find_func_aliases | |
1877 | for the list of builtins we might need to handle here. */ | |
1878 | if (callee != NULL_TREE | |
1879 | && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL) | |
1880 | switch (DECL_FUNCTION_CODE (callee)) | |
1881 | { | |
1882 | /* All the following functions clobber memory pointed to by | |
1883 | their first argument. */ | |
1884 | case BUILT_IN_STRCPY: | |
1885 | case BUILT_IN_STRNCPY: | |
047fdd47 | 1886 | case BUILT_IN_MEMCPY: |
1887 | case BUILT_IN_MEMMOVE: | |
1888 | case BUILT_IN_MEMPCPY: | |
1889 | case BUILT_IN_STPCPY: | |
1890 | case BUILT_IN_STPNCPY: | |
1891 | case BUILT_IN_STRCAT: | |
1892 | case BUILT_IN_STRNCAT: | |
134899ac | 1893 | case BUILT_IN_MEMSET: |
4c0315d0 | 1894 | case BUILT_IN_TM_MEMSET: |
1895 | CASE_BUILT_IN_TM_STORE (1): | |
1896 | CASE_BUILT_IN_TM_STORE (2): | |
1897 | CASE_BUILT_IN_TM_STORE (4): | |
1898 | CASE_BUILT_IN_TM_STORE (8): | |
1899 | CASE_BUILT_IN_TM_STORE (FLOAT): | |
1900 | CASE_BUILT_IN_TM_STORE (DOUBLE): | |
1901 | CASE_BUILT_IN_TM_STORE (LDOUBLE): | |
1902 | CASE_BUILT_IN_TM_STORE (M64): | |
1903 | CASE_BUILT_IN_TM_STORE (M128): | |
1904 | CASE_BUILT_IN_TM_STORE (M256): | |
1905 | case BUILT_IN_TM_MEMCPY: | |
1906 | case BUILT_IN_TM_MEMMOVE: | |
047fdd47 | 1907 | { |
134899ac | 1908 | ao_ref dref; |
1909 | tree size = NULL_TREE; | |
77efe819 | 1910 | /* Don't pass in size for strncat, as the maximum size |
1911 | is strlen (dest) + n + 1 instead of n, resp. | |
1912 | n + 1 at dest + strlen (dest), but strlen (dest) isn't | |
1913 | known. */ | |
1914 | if (gimple_call_num_args (call) == 3 | |
1915 | && DECL_FUNCTION_CODE (callee) != BUILT_IN_STRNCAT) | |
134899ac | 1916 | size = gimple_call_arg (call, 2); |
1917 | ao_ref_init_from_ptr_and_size (&dref, | |
1918 | gimple_call_arg (call, 0), | |
1919 | size); | |
1920 | return refs_may_alias_p_1 (&dref, ref, false); | |
047fdd47 | 1921 | } |
939514e9 | 1922 | case BUILT_IN_STRCPY_CHK: |
1923 | case BUILT_IN_STRNCPY_CHK: | |
1924 | case BUILT_IN_MEMCPY_CHK: | |
1925 | case BUILT_IN_MEMMOVE_CHK: | |
1926 | case BUILT_IN_MEMPCPY_CHK: | |
1927 | case BUILT_IN_STPCPY_CHK: | |
1063acde | 1928 | case BUILT_IN_STPNCPY_CHK: |
939514e9 | 1929 | case BUILT_IN_STRCAT_CHK: |
1930 | case BUILT_IN_STRNCAT_CHK: | |
1931 | case BUILT_IN_MEMSET_CHK: | |
1932 | { | |
1933 | ao_ref dref; | |
1934 | tree size = NULL_TREE; | |
77efe819 | 1935 | /* Don't pass in size for __strncat_chk, as the maximum size |
1936 | is strlen (dest) + n + 1 instead of n, resp. | |
1937 | n + 1 at dest + strlen (dest), but strlen (dest) isn't | |
1938 | known. */ | |
1939 | if (gimple_call_num_args (call) == 4 | |
1940 | && DECL_FUNCTION_CODE (callee) != BUILT_IN_STRNCAT_CHK) | |
939514e9 | 1941 | size = gimple_call_arg (call, 2); |
1942 | ao_ref_init_from_ptr_and_size (&dref, | |
1943 | gimple_call_arg (call, 0), | |
1944 | size); | |
1945 | return refs_may_alias_p_1 (&dref, ref, false); | |
1946 | } | |
119147d1 | 1947 | case BUILT_IN_BCOPY: |
1948 | { | |
1949 | ao_ref dref; | |
1950 | tree size = gimple_call_arg (call, 2); | |
1951 | ao_ref_init_from_ptr_and_size (&dref, | |
1952 | gimple_call_arg (call, 1), | |
1953 | size); | |
1954 | return refs_may_alias_p_1 (&dref, ref, false); | |
1955 | } | |
0d3ca08e | 1956 | /* Allocating memory does not have any side-effects apart from |
1957 | being the definition point for the pointer. */ | |
1958 | case BUILT_IN_MALLOC: | |
4ef43bbd | 1959 | case BUILT_IN_CALLOC: |
77efe819 | 1960 | case BUILT_IN_STRDUP: |
1961 | case BUILT_IN_STRNDUP: | |
be97d4b6 | 1962 | /* Unix98 specifies that errno is set on allocation failure. */ |
a29c5f9c | 1963 | if (flag_errno_math |
be97d4b6 | 1964 | && targetm.ref_may_alias_errno (ref)) |
1965 | return true; | |
0d3ca08e | 1966 | return false; |
ca793672 | 1967 | case BUILT_IN_STACK_SAVE: |
1968 | case BUILT_IN_ALLOCA: | |
581bf1c2 | 1969 | case BUILT_IN_ALLOCA_WITH_ALIGN: |
fca0886c | 1970 | case BUILT_IN_ASSUME_ALIGNED: |
ca793672 | 1971 | return false; |
be2c7f8f | 1972 | /* But posix_memalign stores a pointer into the memory pointed to |
1973 | by its first argument. */ | |
1974 | case BUILT_IN_POSIX_MEMALIGN: | |
1975 | { | |
1976 | tree ptrptr = gimple_call_arg (call, 0); | |
1977 | ao_ref dref; | |
1978 | ao_ref_init_from_ptr_and_size (&dref, ptrptr, | |
1979 | TYPE_SIZE_UNIT (ptr_type_node)); | |
1980 | return (refs_may_alias_p_1 (&dref, ref, false) | |
1981 | || (flag_errno_math | |
1982 | && targetm.ref_may_alias_errno (ref))); | |
1983 | } | |
047fdd47 | 1984 | /* Freeing memory kills the pointed-to memory. More importantly |
1985 | the call has to serve as a barrier for moving loads and stores | |
134899ac | 1986 | across it. */ |
047fdd47 | 1987 | case BUILT_IN_FREE: |
9d17b4a8 | 1988 | case BUILT_IN_VA_END: |
047fdd47 | 1989 | { |
1990 | tree ptr = gimple_call_arg (call, 0); | |
1991 | return ptr_deref_may_alias_ref_p_1 (ptr, ref); | |
1992 | } | |
047fdd47 | 1993 | case BUILT_IN_GAMMA_R: |
1994 | case BUILT_IN_GAMMAF_R: | |
1995 | case BUILT_IN_GAMMAL_R: | |
1996 | case BUILT_IN_LGAMMA_R: | |
1997 | case BUILT_IN_LGAMMAF_R: | |
1998 | case BUILT_IN_LGAMMAL_R: | |
09d9c774 | 1999 | { |
2000 | tree out = gimple_call_arg (call, 1); | |
2001 | if (ptr_deref_may_alias_ref_p_1 (out, ref)) | |
2002 | return true; | |
2003 | if (flag_errno_math) | |
2004 | break; | |
2005 | return false; | |
2006 | } | |
2007 | case BUILT_IN_FREXP: | |
2008 | case BUILT_IN_FREXPF: | |
2009 | case BUILT_IN_FREXPL: | |
047fdd47 | 2010 | case BUILT_IN_MODF: |
2011 | case BUILT_IN_MODFF: | |
2012 | case BUILT_IN_MODFL: | |
2013 | { | |
2014 | tree out = gimple_call_arg (call, 1); | |
2015 | return ptr_deref_may_alias_ref_p_1 (out, ref); | |
2016 | } | |
2017 | case BUILT_IN_REMQUO: | |
2018 | case BUILT_IN_REMQUOF: | |
2019 | case BUILT_IN_REMQUOL: | |
2020 | { | |
2021 | tree out = gimple_call_arg (call, 2); | |
09d9c774 | 2022 | if (ptr_deref_may_alias_ref_p_1 (out, ref)) |
2023 | return true; | |
2024 | if (flag_errno_math) | |
2025 | break; | |
2026 | return false; | |
047fdd47 | 2027 | } |
2028 | case BUILT_IN_SINCOS: | |
2029 | case BUILT_IN_SINCOSF: | |
2030 | case BUILT_IN_SINCOSL: | |
2031 | { | |
2032 | tree sin = gimple_call_arg (call, 1); | |
2033 | tree cos = gimple_call_arg (call, 2); | |
2034 | return (ptr_deref_may_alias_ref_p_1 (sin, ref) | |
2035 | || ptr_deref_may_alias_ref_p_1 (cos, ref)); | |
2036 | } | |
a44814b9 | 2037 | /* __sync_* builtins and some OpenMP builtins act as threading |
2038 | barriers. */ | |
2039 | #undef DEF_SYNC_BUILTIN | |
2040 | #define DEF_SYNC_BUILTIN(ENUM, NAME, TYPE, ATTRS) case ENUM: | |
2041 | #include "sync-builtins.def" | |
2042 | #undef DEF_SYNC_BUILTIN | |
2043 | case BUILT_IN_GOMP_ATOMIC_START: | |
2044 | case BUILT_IN_GOMP_ATOMIC_END: | |
2045 | case BUILT_IN_GOMP_BARRIER: | |
bc7bff74 | 2046 | case BUILT_IN_GOMP_BARRIER_CANCEL: |
a44814b9 | 2047 | case BUILT_IN_GOMP_TASKWAIT: |
bc7bff74 | 2048 | case BUILT_IN_GOMP_TASKGROUP_END: |
a44814b9 | 2049 | case BUILT_IN_GOMP_CRITICAL_START: |
2050 | case BUILT_IN_GOMP_CRITICAL_END: | |
2051 | case BUILT_IN_GOMP_CRITICAL_NAME_START: | |
2052 | case BUILT_IN_GOMP_CRITICAL_NAME_END: | |
2053 | case BUILT_IN_GOMP_LOOP_END: | |
bc7bff74 | 2054 | case BUILT_IN_GOMP_LOOP_END_CANCEL: |
a44814b9 | 2055 | case BUILT_IN_GOMP_ORDERED_START: |
2056 | case BUILT_IN_GOMP_ORDERED_END: | |
a44814b9 | 2057 | case BUILT_IN_GOMP_SECTIONS_END: |
bc7bff74 | 2058 | case BUILT_IN_GOMP_SECTIONS_END_CANCEL: |
a44814b9 | 2059 | case BUILT_IN_GOMP_SINGLE_COPY_START: |
2060 | case BUILT_IN_GOMP_SINGLE_COPY_END: | |
2061 | return true; | |
047fdd47 | 2062 | default: |
2063 | /* Fallthru to general call handling. */; | |
2064 | } | |
2065 | ||
dd277d48 | 2066 | /* Check if base is a global static variable that is not written |
2067 | by the function. */ | |
047fdd47 | 2068 | if (callee != NULL_TREE |
2069 | && TREE_CODE (base) == VAR_DECL | |
d97be713 | 2070 | && TREE_STATIC (base)) |
4ee9c684 | 2071 | { |
924de091 | 2072 | struct cgraph_node *node = cgraph_get_node (callee); |
dd277d48 | 2073 | bitmap not_written; |
0eaf9bd7 | 2074 | |
924de091 | 2075 | if (node |
2076 | && (not_written = ipa_reference_get_not_written_global (node)) | |
dd277d48 | 2077 | && bitmap_bit_p (not_written, DECL_UID (base))) |
2078 | return false; | |
4ee9c684 | 2079 | } |
4ee9c684 | 2080 | |
cb245216 | 2081 | /* Check if the base variable is call-clobbered. */ |
dd277d48 | 2082 | if (DECL_P (base)) |
cb245216 | 2083 | return pt_solution_includes (gimple_call_clobber_set (call), base); |
2622064f | 2084 | else if ((TREE_CODE (base) == MEM_REF |
2085 | || TREE_CODE (base) == TARGET_MEM_REF) | |
917f08fa | 2086 | && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME) |
2087 | { | |
2088 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0)); | |
2089 | if (!pi) | |
2090 | return true; | |
2091 | ||
cb245216 | 2092 | return pt_solutions_intersect (gimple_call_clobber_set (call), &pi->pt); |
917f08fa | 2093 | } |
4ee9c684 | 2094 | |
dd277d48 | 2095 | return true; |
2096 | } | |
4ee9c684 | 2097 | |
4debfcfc | 2098 | /* If the call in statement CALL may clobber the memory reference REF |
2099 | return true, otherwise return false. */ | |
2100 | ||
2101 | bool | |
dd277d48 | 2102 | call_may_clobber_ref_p (gimple call, tree ref) |
4ee9c684 | 2103 | { |
3918bd18 | 2104 | bool res; |
2105 | ao_ref r; | |
2106 | ao_ref_init (&r, ref); | |
2107 | res = call_may_clobber_ref_p_1 (call, &r); | |
dd277d48 | 2108 | if (res) |
2109 | ++alias_stats.call_may_clobber_ref_p_may_alias; | |
2110 | else | |
2111 | ++alias_stats.call_may_clobber_ref_p_no_alias; | |
2112 | return res; | |
4ee9c684 | 2113 | } |
94e6573f | 2114 | |
dd277d48 | 2115 | |
2116 | /* If the statement STMT may clobber the memory reference REF return true, | |
2117 | otherwise return false. */ | |
94e6573f | 2118 | |
2119 | bool | |
3918bd18 | 2120 | stmt_may_clobber_ref_p_1 (gimple stmt, ao_ref *ref) |
94e6573f | 2121 | { |
dd277d48 | 2122 | if (is_gimple_call (stmt)) |
2123 | { | |
2124 | tree lhs = gimple_call_lhs (stmt); | |
2125 | if (lhs | |
66b86a74 | 2126 | && TREE_CODE (lhs) != SSA_NAME) |
3918bd18 | 2127 | { |
2128 | ao_ref r; | |
2129 | ao_ref_init (&r, lhs); | |
2130 | if (refs_may_alias_p_1 (ref, &r, true)) | |
2131 | return true; | |
2132 | } | |
94e6573f | 2133 | |
3918bd18 | 2134 | return call_may_clobber_ref_p_1 (stmt, ref); |
dd277d48 | 2135 | } |
8e7c2b9c | 2136 | else if (gimple_assign_single_p (stmt)) |
3918bd18 | 2137 | { |
8e7c2b9c | 2138 | tree lhs = gimple_assign_lhs (stmt); |
66b86a74 | 2139 | if (TREE_CODE (lhs) != SSA_NAME) |
8e7c2b9c | 2140 | { |
2141 | ao_ref r; | |
66b86a74 | 2142 | ao_ref_init (&r, lhs); |
8e7c2b9c | 2143 | return refs_may_alias_p_1 (ref, &r, true); |
2144 | } | |
3918bd18 | 2145 | } |
dd277d48 | 2146 | else if (gimple_code (stmt) == GIMPLE_ASM) |
94e6573f | 2147 | return true; |
2148 | ||
6329636b | 2149 | return false; |
94e6573f | 2150 | } |
2be14d8b | 2151 | |
3918bd18 | 2152 | bool |
2153 | stmt_may_clobber_ref_p (gimple stmt, tree ref) | |
2154 | { | |
2155 | ao_ref r; | |
2156 | ao_ref_init (&r, ref); | |
2157 | return stmt_may_clobber_ref_p_1 (stmt, &r); | |
2158 | } | |
2159 | ||
ab450cc6 | 2160 | /* If STMT kills the memory reference REF return true, otherwise |
2161 | return false. */ | |
2162 | ||
2163 | static bool | |
2164 | stmt_kills_ref_p_1 (gimple stmt, ao_ref *ref) | |
2165 | { | |
07ff6a65 | 2166 | /* For a must-alias check we need to be able to constrain |
e6c705fb | 2167 | the access properly. |
2168 | FIXME: except for BUILTIN_FREE. */ | |
2169 | if (!ao_ref_base (ref) | |
2170 | || ref->max_size == -1) | |
07ff6a65 | 2171 | return false; |
2172 | ||
ab450cc6 | 2173 | if (gimple_has_lhs (stmt) |
e54d36c4 | 2174 | && TREE_CODE (gimple_get_lhs (stmt)) != SSA_NAME |
2175 | /* The assignment is not necessarily carried out if it can throw | |
2176 | and we can catch it in the current function where we could inspect | |
2177 | the previous value. | |
2178 | ??? We only need to care about the RHS throwing. For aggregate | |
2179 | assignments or similar calls and non-call exceptions the LHS | |
2180 | might throw as well. */ | |
2181 | && !stmt_can_throw_internal (stmt)) | |
ab450cc6 | 2182 | { |
2183 | tree base, lhs = gimple_get_lhs (stmt); | |
137eddca | 2184 | HOST_WIDE_INT size, offset, max_size, ref_offset = ref->offset; |
ab450cc6 | 2185 | base = get_ref_base_and_extent (lhs, &offset, &size, &max_size); |
2186 | /* We can get MEM[symbol: sZ, index: D.8862_1] here, | |
2187 | so base == ref->base does not always hold. */ | |
137eddca | 2188 | if (base != ref->base) |
ab450cc6 | 2189 | { |
137eddca | 2190 | /* If both base and ref->base are MEM_REFs, only compare the |
2191 | first operand, and if the second operand isn't equal constant, | |
2192 | try to add the offsets into offset and ref_offset. */ | |
2193 | if (TREE_CODE (base) == MEM_REF && TREE_CODE (ref->base) == MEM_REF | |
2194 | && TREE_OPERAND (base, 0) == TREE_OPERAND (ref->base, 0)) | |
ab450cc6 | 2195 | { |
83d18d6d | 2196 | if (!tree_int_cst_equal (TREE_OPERAND (base, 1), |
2197 | TREE_OPERAND (ref->base, 1))) | |
137eddca | 2198 | { |
2199 | double_int off1 = mem_ref_offset (base); | |
9a8b9e26 | 2200 | off1 = off1.lshift (BITS_PER_UNIT == 8 |
2201 | ? 3 : exact_log2 (BITS_PER_UNIT)); | |
137eddca | 2202 | off1 = off1 + double_int::from_shwi (offset); |
2203 | double_int off2 = mem_ref_offset (ref->base); | |
9a8b9e26 | 2204 | off2 = off2.lshift (BITS_PER_UNIT == 8 |
2205 | ? 3 : exact_log2 (BITS_PER_UNIT)); | |
137eddca | 2206 | off2 = off2 + double_int::from_shwi (ref_offset); |
2207 | if (off1.fits_shwi () && off2.fits_shwi ()) | |
2208 | { | |
2209 | offset = off1.to_shwi (); | |
2210 | ref_offset = off2.to_shwi (); | |
2211 | } | |
2212 | else | |
2213 | size = -1; | |
2214 | } | |
ab450cc6 | 2215 | } |
137eddca | 2216 | else |
2217 | size = -1; | |
2218 | } | |
2219 | /* For a must-alias check we need to be able to constrain | |
2220 | the access properly. */ | |
2221 | if (size != -1 && size == max_size) | |
2222 | { | |
2223 | if (offset <= ref_offset | |
2224 | && offset + size >= ref_offset + ref->max_size) | |
2225 | return true; | |
ab450cc6 | 2226 | } |
2227 | } | |
07ff6a65 | 2228 | |
2229 | if (is_gimple_call (stmt)) | |
2230 | { | |
2231 | tree callee = gimple_call_fndecl (stmt); | |
2232 | if (callee != NULL_TREE | |
2233 | && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL) | |
2234 | switch (DECL_FUNCTION_CODE (callee)) | |
2235 | { | |
3d0ea943 | 2236 | case BUILT_IN_FREE: |
2237 | { | |
2238 | tree ptr = gimple_call_arg (stmt, 0); | |
2239 | tree base = ao_ref_base (ref); | |
2240 | if (base && TREE_CODE (base) == MEM_REF | |
2241 | && TREE_OPERAND (base, 0) == ptr) | |
2242 | return true; | |
2243 | break; | |
2244 | } | |
2245 | ||
07ff6a65 | 2246 | case BUILT_IN_MEMCPY: |
2247 | case BUILT_IN_MEMPCPY: | |
2248 | case BUILT_IN_MEMMOVE: | |
2249 | case BUILT_IN_MEMSET: | |
939514e9 | 2250 | case BUILT_IN_MEMCPY_CHK: |
2251 | case BUILT_IN_MEMPCPY_CHK: | |
2252 | case BUILT_IN_MEMMOVE_CHK: | |
2253 | case BUILT_IN_MEMSET_CHK: | |
07ff6a65 | 2254 | { |
2255 | tree dest = gimple_call_arg (stmt, 0); | |
2256 | tree len = gimple_call_arg (stmt, 2); | |
35ec552a | 2257 | if (!tree_fits_shwi_p (len)) |
07ff6a65 | 2258 | return false; |
e6c705fb | 2259 | tree rbase = ref->base; |
2260 | double_int roffset = double_int::from_shwi (ref->offset); | |
2261 | ao_ref dref; | |
2262 | ao_ref_init_from_ptr_and_size (&dref, dest, len); | |
2263 | tree base = ao_ref_base (&dref); | |
2264 | double_int offset = double_int::from_shwi (dref.offset); | |
2265 | double_int bpu = double_int::from_uhwi (BITS_PER_UNIT); | |
2266 | if (!base || dref.size == -1) | |
2267 | return false; | |
2268 | if (TREE_CODE (base) == MEM_REF) | |
2269 | { | |
2270 | if (TREE_CODE (rbase) != MEM_REF) | |
2271 | return false; | |
2272 | // Compare pointers. | |
2273 | offset += bpu * mem_ref_offset (base); | |
2274 | roffset += bpu * mem_ref_offset (rbase); | |
2275 | base = TREE_OPERAND (base, 0); | |
2276 | rbase = TREE_OPERAND (rbase, 0); | |
2277 | } | |
2278 | if (base == rbase) | |
07ff6a65 | 2279 | { |
e6c705fb | 2280 | double_int size = bpu * tree_to_double_int (len); |
2281 | double_int rsize = double_int::from_uhwi (ref->max_size); | |
2282 | if (offset.sle (roffset) | |
2283 | && (roffset + rsize).sle (offset + size)) | |
07ff6a65 | 2284 | return true; |
2285 | } | |
9d17b4a8 | 2286 | break; |
2287 | } | |
2288 | ||
2289 | case BUILT_IN_VA_END: | |
2290 | { | |
2291 | tree ptr = gimple_call_arg (stmt, 0); | |
2292 | if (TREE_CODE (ptr) == ADDR_EXPR) | |
2293 | { | |
2294 | tree base = ao_ref_base (ref); | |
2295 | if (TREE_OPERAND (ptr, 0) == base) | |
2296 | return true; | |
2297 | } | |
2298 | break; | |
07ff6a65 | 2299 | } |
9d17b4a8 | 2300 | |
07ff6a65 | 2301 | default:; |
2302 | } | |
07ff6a65 | 2303 | } |
ab450cc6 | 2304 | return false; |
2305 | } | |
2306 | ||
2307 | bool | |
2308 | stmt_kills_ref_p (gimple stmt, tree ref) | |
2309 | { | |
2310 | ao_ref r; | |
2311 | ao_ref_init (&r, ref); | |
2312 | return stmt_kills_ref_p_1 (stmt, &r); | |
2313 | } | |
2314 | ||
3918bd18 | 2315 | |
dd277d48 | 2316 | /* Walk the virtual use-def chain of VUSE until hitting the virtual operand |
2317 | TARGET or a statement clobbering the memory reference REF in which | |
2318 | case false is returned. The walk starts with VUSE, one argument of PHI. */ | |
2319 | ||
2320 | static bool | |
3918bd18 | 2321 | maybe_skip_until (gimple phi, tree target, ao_ref *ref, |
4fd7a6de | 2322 | tree vuse, unsigned int *cnt, bitmap *visited, |
2323 | bool abort_on_visited) | |
ac926412 | 2324 | { |
0afe880d | 2325 | basic_block bb = gimple_bb (phi); |
2326 | ||
dd277d48 | 2327 | if (!*visited) |
2328 | *visited = BITMAP_ALLOC (NULL); | |
ac926412 | 2329 | |
dd277d48 | 2330 | bitmap_set_bit (*visited, SSA_NAME_VERSION (PHI_RESULT (phi))); |
2331 | ||
2332 | /* Walk until we hit the target. */ | |
2333 | while (vuse != target) | |
ac926412 | 2334 | { |
dd277d48 | 2335 | gimple def_stmt = SSA_NAME_DEF_STMT (vuse); |
2336 | /* Recurse for PHI nodes. */ | |
2337 | if (gimple_code (def_stmt) == GIMPLE_PHI) | |
2338 | { | |
2339 | /* An already visited PHI node ends the walk successfully. */ | |
2340 | if (bitmap_bit_p (*visited, SSA_NAME_VERSION (PHI_RESULT (def_stmt)))) | |
4fd7a6de | 2341 | return !abort_on_visited; |
2342 | vuse = get_continuation_for_phi (def_stmt, ref, cnt, | |
2343 | visited, abort_on_visited); | |
dd277d48 | 2344 | if (!vuse) |
2345 | return false; | |
2346 | continue; | |
2347 | } | |
297a2110 | 2348 | else if (gimple_nop_p (def_stmt)) |
dd277d48 | 2349 | return false; |
297a2110 | 2350 | else |
2351 | { | |
2352 | /* A clobbering statement or the end of the IL ends it failing. */ | |
2353 | ++*cnt; | |
2354 | if (stmt_may_clobber_ref_p_1 (def_stmt, ref)) | |
2355 | return false; | |
2356 | } | |
0afe880d | 2357 | /* If we reach a new basic-block see if we already skipped it |
2358 | in a previous walk that ended successfully. */ | |
2359 | if (gimple_bb (def_stmt) != bb) | |
2360 | { | |
2361 | if (!bitmap_set_bit (*visited, SSA_NAME_VERSION (vuse))) | |
4fd7a6de | 2362 | return !abort_on_visited; |
0afe880d | 2363 | bb = gimple_bb (def_stmt); |
2364 | } | |
dd277d48 | 2365 | vuse = gimple_vuse (def_stmt); |
ac926412 | 2366 | } |
dd277d48 | 2367 | return true; |
2368 | } | |
ac926412 | 2369 | |
d7f69727 | 2370 | /* For two PHI arguments ARG0 and ARG1 try to skip non-aliasing code |
2371 | until we hit the phi argument definition that dominates the other one. | |
2372 | Return that, or NULL_TREE if there is no such definition. */ | |
2373 | ||
2374 | static tree | |
2375 | get_continuation_for_phi_1 (gimple phi, tree arg0, tree arg1, | |
4fd7a6de | 2376 | ao_ref *ref, unsigned int *cnt, |
2377 | bitmap *visited, bool abort_on_visited) | |
d7f69727 | 2378 | { |
2379 | gimple def0 = SSA_NAME_DEF_STMT (arg0); | |
2380 | gimple def1 = SSA_NAME_DEF_STMT (arg1); | |
2381 | tree common_vuse; | |
2382 | ||
2383 | if (arg0 == arg1) | |
2384 | return arg0; | |
2385 | else if (gimple_nop_p (def0) | |
2386 | || (!gimple_nop_p (def1) | |
2387 | && dominated_by_p (CDI_DOMINATORS, | |
2388 | gimple_bb (def1), gimple_bb (def0)))) | |
2389 | { | |
4fd7a6de | 2390 | if (maybe_skip_until (phi, arg0, ref, arg1, cnt, |
2391 | visited, abort_on_visited)) | |
d7f69727 | 2392 | return arg0; |
2393 | } | |
2394 | else if (gimple_nop_p (def1) | |
2395 | || dominated_by_p (CDI_DOMINATORS, | |
2396 | gimple_bb (def0), gimple_bb (def1))) | |
2397 | { | |
4fd7a6de | 2398 | if (maybe_skip_until (phi, arg1, ref, arg0, cnt, |
2399 | visited, abort_on_visited)) | |
d7f69727 | 2400 | return arg1; |
2401 | } | |
2402 | /* Special case of a diamond: | |
2403 | MEM_1 = ... | |
2404 | goto (cond) ? L1 : L2 | |
2405 | L1: store1 = ... #MEM_2 = vuse(MEM_1) | |
2406 | goto L3 | |
2407 | L2: store2 = ... #MEM_3 = vuse(MEM_1) | |
2408 | L3: MEM_4 = PHI<MEM_2, MEM_3> | |
2409 | We were called with the PHI at L3, MEM_2 and MEM_3 don't | |
2410 | dominate each other, but still we can easily skip this PHI node | |
2411 | if we recognize that the vuse MEM operand is the same for both, | |
2412 | and that we can skip both statements (they don't clobber us). | |
2413 | This is still linear. Don't use maybe_skip_until, that might | |
2414 | potentially be slow. */ | |
2415 | else if ((common_vuse = gimple_vuse (def0)) | |
2416 | && common_vuse == gimple_vuse (def1)) | |
2417 | { | |
297a2110 | 2418 | *cnt += 2; |
d7f69727 | 2419 | if (!stmt_may_clobber_ref_p_1 (def0, ref) |
2420 | && !stmt_may_clobber_ref_p_1 (def1, ref)) | |
2421 | return common_vuse; | |
2422 | } | |
2423 | ||
2424 | return NULL_TREE; | |
2425 | } | |
2426 | ||
2427 | ||
dd277d48 | 2428 | /* Starting from a PHI node for the virtual operand of the memory reference |
2429 | REF find a continuation virtual operand that allows to continue walking | |
2430 | statements dominating PHI skipping only statements that cannot possibly | |
297a2110 | 2431 | clobber REF. Increments *CNT for each alias disambiguation done. |
2432 | Returns NULL_TREE if no suitable virtual operand can be found. */ | |
dd277d48 | 2433 | |
7814d418 | 2434 | tree |
297a2110 | 2435 | get_continuation_for_phi (gimple phi, ao_ref *ref, |
4fd7a6de | 2436 | unsigned int *cnt, bitmap *visited, |
2437 | bool abort_on_visited) | |
dd277d48 | 2438 | { |
2439 | unsigned nargs = gimple_phi_num_args (phi); | |
2440 | ||
2441 | /* Through a single-argument PHI we can simply look through. */ | |
2442 | if (nargs == 1) | |
2443 | return PHI_ARG_DEF (phi, 0); | |
2444 | ||
d7f69727 | 2445 | /* For two or more arguments try to pairwise skip non-aliasing code |
2446 | until we hit the phi argument definition that dominates the other one. */ | |
2447 | else if (nargs >= 2) | |
ac926412 | 2448 | { |
0afe880d | 2449 | tree arg0, arg1; |
2450 | unsigned i; | |
2451 | ||
2452 | /* Find a candidate for the virtual operand which definition | |
2453 | dominates those of all others. */ | |
2454 | arg0 = PHI_ARG_DEF (phi, 0); | |
2455 | if (!SSA_NAME_IS_DEFAULT_DEF (arg0)) | |
2456 | for (i = 1; i < nargs; ++i) | |
2457 | { | |
2458 | arg1 = PHI_ARG_DEF (phi, i); | |
2459 | if (SSA_NAME_IS_DEFAULT_DEF (arg1)) | |
2460 | { | |
2461 | arg0 = arg1; | |
2462 | break; | |
2463 | } | |
2464 | if (dominated_by_p (CDI_DOMINATORS, | |
2465 | gimple_bb (SSA_NAME_DEF_STMT (arg0)), | |
2466 | gimple_bb (SSA_NAME_DEF_STMT (arg1)))) | |
2467 | arg0 = arg1; | |
2468 | } | |
2469 | ||
2470 | /* Then pairwise reduce against the found candidate. */ | |
2471 | for (i = 0; i < nargs; ++i) | |
7814d418 | 2472 | { |
d7f69727 | 2473 | arg1 = PHI_ARG_DEF (phi, i); |
297a2110 | 2474 | arg0 = get_continuation_for_phi_1 (phi, arg0, arg1, ref, |
4fd7a6de | 2475 | cnt, visited, abort_on_visited); |
d7f69727 | 2476 | if (!arg0) |
2477 | return NULL_TREE; | |
7814d418 | 2478 | } |
d7f69727 | 2479 | |
2480 | return arg0; | |
ac926412 | 2481 | } |
dd277d48 | 2482 | |
2483 | return NULL_TREE; | |
ac926412 | 2484 | } |
516849c7 | 2485 | |
dd277d48 | 2486 | /* Based on the memory reference REF and its virtual use VUSE call |
2487 | WALKER for each virtual use that is equivalent to VUSE, including VUSE | |
2488 | itself. That is, for each virtual use for which its defining statement | |
2489 | does not clobber REF. | |
e683de6d | 2490 | |
dd277d48 | 2491 | WALKER is called with REF, the current virtual use and DATA. If |
2492 | WALKER returns non-NULL the walk stops and its result is returned. | |
2493 | At the end of a non-successful walk NULL is returned. | |
3857274c | 2494 | |
d8021dea | 2495 | TRANSLATE if non-NULL is called with a pointer to REF, the virtual |
2496 | use which definition is a statement that may clobber REF and DATA. | |
2497 | If TRANSLATE returns (void *)-1 the walk stops and NULL is returned. | |
2498 | If TRANSLATE returns non-NULL the walk stops and its result is returned. | |
2499 | If TRANSLATE returns NULL the walk continues and TRANSLATE is supposed | |
2500 | to adjust REF and *DATA to make that valid. | |
2501 | ||
dd277d48 | 2502 | TODO: Cache the vector of equivalent vuses per ref, vuse pair. */ |
2503 | ||
2504 | void * | |
3918bd18 | 2505 | walk_non_aliased_vuses (ao_ref *ref, tree vuse, |
297a2110 | 2506 | void *(*walker)(ao_ref *, tree, unsigned int, void *), |
3918bd18 | 2507 | void *(*translate)(ao_ref *, tree, void *), void *data) |
3857274c | 2508 | { |
dd277d48 | 2509 | bitmap visited = NULL; |
2510 | void *res; | |
297a2110 | 2511 | unsigned int cnt = 0; |
4fd7a6de | 2512 | bool translated = false; |
dd277d48 | 2513 | |
02c74b9b | 2514 | timevar_push (TV_ALIAS_STMT_WALK); |
2515 | ||
dd277d48 | 2516 | do |
2517 | { | |
2518 | gimple def_stmt; | |
3857274c | 2519 | |
02c74b9b | 2520 | /* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */ |
297a2110 | 2521 | res = (*walker) (ref, vuse, cnt, data); |
2522 | /* Abort walk. */ | |
2523 | if (res == (void *)-1) | |
2524 | { | |
2525 | res = NULL; | |
2526 | break; | |
2527 | } | |
2528 | /* Lookup succeeded. */ | |
2529 | else if (res != NULL) | |
dd277d48 | 2530 | break; |
3857274c | 2531 | |
dd277d48 | 2532 | def_stmt = SSA_NAME_DEF_STMT (vuse); |
2533 | if (gimple_nop_p (def_stmt)) | |
2534 | break; | |
2535 | else if (gimple_code (def_stmt) == GIMPLE_PHI) | |
4fd7a6de | 2536 | vuse = get_continuation_for_phi (def_stmt, ref, &cnt, |
2537 | &visited, translated); | |
dd277d48 | 2538 | else |
2539 | { | |
297a2110 | 2540 | cnt++; |
3918bd18 | 2541 | if (stmt_may_clobber_ref_p_1 (def_stmt, ref)) |
d8021dea | 2542 | { |
2543 | if (!translate) | |
2544 | break; | |
3918bd18 | 2545 | res = (*translate) (ref, vuse, data); |
d8021dea | 2546 | /* Failed lookup and translation. */ |
2547 | if (res == (void *)-1) | |
2548 | { | |
2549 | res = NULL; | |
2550 | break; | |
2551 | } | |
2552 | /* Lookup succeeded. */ | |
2553 | else if (res != NULL) | |
2554 | break; | |
2555 | /* Translation succeeded, continue walking. */ | |
4fd7a6de | 2556 | translated = true; |
d8021dea | 2557 | } |
dd277d48 | 2558 | vuse = gimple_vuse (def_stmt); |
2559 | } | |
2560 | } | |
2561 | while (vuse); | |
ac926412 | 2562 | |
dd277d48 | 2563 | if (visited) |
2564 | BITMAP_FREE (visited); | |
ac926412 | 2565 | |
02c74b9b | 2566 | timevar_pop (TV_ALIAS_STMT_WALK); |
2567 | ||
dd277d48 | 2568 | return res; |
3857274c | 2569 | } |
2570 | ||
604eef2c | 2571 | |
dd277d48 | 2572 | /* Based on the memory reference REF call WALKER for each vdef which |
2573 | defining statement may clobber REF, starting with VDEF. If REF | |
2574 | is NULL_TREE, each defining statement is visited. | |
2575 | ||
2576 | WALKER is called with REF, the current vdef and DATA. If WALKER | |
2577 | returns true the walk is stopped, otherwise it continues. | |
2578 | ||
2579 | At PHI nodes walk_aliased_vdefs forks into one walk for reach | |
2580 | PHI argument (but only one walk continues on merge points), the | |
2581 | return value is true if any of the walks was successful. | |
2582 | ||
2583 | The function returns the number of statements walked. */ | |
604eef2c | 2584 | |
2585 | static unsigned int | |
1daead67 | 2586 | walk_aliased_vdefs_1 (ao_ref *ref, tree vdef, |
2587 | bool (*walker)(ao_ref *, tree, void *), void *data, | |
dd277d48 | 2588 | bitmap *visited, unsigned int cnt) |
604eef2c | 2589 | { |
dd277d48 | 2590 | do |
2591 | { | |
2592 | gimple def_stmt = SSA_NAME_DEF_STMT (vdef); | |
604eef2c | 2593 | |
dd277d48 | 2594 | if (*visited |
2595 | && !bitmap_set_bit (*visited, SSA_NAME_VERSION (vdef))) | |
2596 | return cnt; | |
2597 | ||
2598 | if (gimple_nop_p (def_stmt)) | |
2599 | return cnt; | |
2600 | else if (gimple_code (def_stmt) == GIMPLE_PHI) | |
2601 | { | |
2602 | unsigned i; | |
2603 | if (!*visited) | |
2604 | *visited = BITMAP_ALLOC (NULL); | |
2605 | for (i = 0; i < gimple_phi_num_args (def_stmt); ++i) | |
2606 | cnt += walk_aliased_vdefs_1 (ref, gimple_phi_arg_def (def_stmt, i), | |
2607 | walker, data, visited, 0); | |
2608 | return cnt; | |
2609 | } | |
2610 | ||
02c74b9b | 2611 | /* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */ |
dd277d48 | 2612 | cnt++; |
2613 | if ((!ref | |
1daead67 | 2614 | || stmt_may_clobber_ref_p_1 (def_stmt, ref)) |
dd277d48 | 2615 | && (*walker) (ref, vdef, data)) |
2616 | return cnt; | |
2617 | ||
2618 | vdef = gimple_vuse (def_stmt); | |
2619 | } | |
2620 | while (1); | |
604eef2c | 2621 | } |
2622 | ||
dd277d48 | 2623 | unsigned int |
1daead67 | 2624 | walk_aliased_vdefs (ao_ref *ref, tree vdef, |
2625 | bool (*walker)(ao_ref *, tree, void *), void *data, | |
dd277d48 | 2626 | bitmap *visited) |
df3f0669 | 2627 | { |
dd277d48 | 2628 | bitmap local_visited = NULL; |
2629 | unsigned int ret; | |
2630 | ||
02c74b9b | 2631 | timevar_push (TV_ALIAS_STMT_WALK); |
2632 | ||
dd277d48 | 2633 | ret = walk_aliased_vdefs_1 (ref, vdef, walker, data, |
2634 | visited ? visited : &local_visited, 0); | |
2635 | if (local_visited) | |
2636 | BITMAP_FREE (local_visited); | |
2637 | ||
02c74b9b | 2638 | timevar_pop (TV_ALIAS_STMT_WALK); |
2639 | ||
dd277d48 | 2640 | return ret; |
2641 | } | |
2642 |