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4ee9c684 | 1 | /* Alias analysis for trees. |
711789cc | 2 | Copyright (C) 2004-2013 Free Software Foundation, Inc. |
4ee9c684 | 3 | Contributed by Diego Novillo <dnovillo@redhat.com> |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
8c4c00c1 | 9 | the Free Software Foundation; either version 3, or (at your option) |
4ee9c684 | 10 | any later version. |
11 | ||
12 | GCC is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
8c4c00c1 | 18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
4ee9c684 | 20 | |
21 | #include "config.h" | |
22 | #include "system.h" | |
23 | #include "coretypes.h" | |
24 | #include "tm.h" | |
25 | #include "tree.h" | |
4ee9c684 | 26 | #include "tm_p.h" |
be97d4b6 | 27 | #include "target.h" |
4ee9c684 | 28 | #include "basic-block.h" |
b9ed1410 | 29 | #include "timevar.h" /* for TV_ALIAS_STMT_WALK */ |
4ee9c684 | 30 | #include "ggc.h" |
31 | #include "langhooks.h" | |
32 | #include "flags.h" | |
33 | #include "function.h" | |
ce084dfc | 34 | #include "tree-pretty-print.h" |
b9ed1410 | 35 | #include "dumpfile.h" |
75a70cf9 | 36 | #include "gimple.h" |
073c1fd5 | 37 | #include "gimple-ssa.h" |
9ed99284 | 38 | #include "stringpool.h" |
073c1fd5 | 39 | #include "tree-ssanames.h" |
9ed99284 | 40 | #include "expr.h" |
073c1fd5 | 41 | #include "tree-dfa.h" |
4ee9c684 | 42 | #include "tree-inline.h" |
4ee9c684 | 43 | #include "params.h" |
2be14d8b | 44 | #include "vec.h" |
4fb5e5ca | 45 | #include "pointer-set.h" |
6cc9bd27 | 46 | #include "alloc-pool.h" |
dd277d48 | 47 | #include "tree-ssa-alias.h" |
dd9784d4 | 48 | #include "ipa-reference.h" |
a55dc2cd | 49 | |
dd277d48 | 50 | /* Broad overview of how alias analysis on gimple works: |
4fb5e5ca | 51 | |
dd277d48 | 52 | Statements clobbering or using memory are linked through the |
53 | virtual operand factored use-def chain. The virtual operand | |
54 | is unique per function, its symbol is accessible via gimple_vop (cfun). | |
55 | Virtual operands are used for efficiently walking memory statements | |
56 | in the gimple IL and are useful for things like value-numbering as | |
57 | a generation count for memory references. | |
339d7079 | 58 | |
dd277d48 | 59 | SSA_NAME pointers may have associated points-to information |
60 | accessible via the SSA_NAME_PTR_INFO macro. Flow-insensitive | |
61 | points-to information is (re-)computed by the TODO_rebuild_alias | |
62 | pass manager todo. Points-to information is also used for more | |
63 | precise tracking of call-clobbered and call-used variables and | |
64 | related disambiguations. | |
339d7079 | 65 | |
dd277d48 | 66 | This file contains functions for disambiguating memory references, |
67 | the so called alias-oracle and tools for walking of the gimple IL. | |
339d7079 | 68 | |
dd277d48 | 69 | The main alias-oracle entry-points are |
339d7079 | 70 | |
dd277d48 | 71 | bool stmt_may_clobber_ref_p (gimple, tree) |
339d7079 | 72 | |
dd277d48 | 73 | This function queries if a statement may invalidate (parts of) |
74 | the memory designated by the reference tree argument. | |
339d7079 | 75 | |
dd277d48 | 76 | bool ref_maybe_used_by_stmt_p (gimple, tree) |
339d7079 | 77 | |
dd277d48 | 78 | This function queries if a statement may need (parts of) the |
79 | memory designated by the reference tree argument. | |
339d7079 | 80 | |
dd277d48 | 81 | There are variants of these functions that only handle the call |
82 | part of a statement, call_may_clobber_ref_p and ref_maybe_used_by_call_p. | |
83 | Note that these do not disambiguate against a possible call lhs. | |
339d7079 | 84 | |
dd277d48 | 85 | bool refs_may_alias_p (tree, tree) |
339d7079 | 86 | |
dd277d48 | 87 | This function tries to disambiguate two reference trees. |
05931b00 | 88 | |
dd277d48 | 89 | bool ptr_deref_may_alias_global_p (tree) |
339d7079 | 90 | |
dd277d48 | 91 | This function queries if dereferencing a pointer variable may |
92 | alias global memory. | |
339d7079 | 93 | |
dd277d48 | 94 | More low-level disambiguators are available and documented in |
95 | this file. Low-level disambiguators dealing with points-to | |
96 | information are in tree-ssa-structalias.c. */ | |
339d7079 | 97 | |
339d7079 | 98 | |
dd277d48 | 99 | /* Query statistics for the different low-level disambiguators. |
100 | A high-level query may trigger multiple of them. */ | |
339d7079 | 101 | |
dd277d48 | 102 | static struct { |
103 | unsigned HOST_WIDE_INT refs_may_alias_p_may_alias; | |
104 | unsigned HOST_WIDE_INT refs_may_alias_p_no_alias; | |
105 | unsigned HOST_WIDE_INT ref_maybe_used_by_call_p_may_alias; | |
106 | unsigned HOST_WIDE_INT ref_maybe_used_by_call_p_no_alias; | |
107 | unsigned HOST_WIDE_INT call_may_clobber_ref_p_may_alias; | |
108 | unsigned HOST_WIDE_INT call_may_clobber_ref_p_no_alias; | |
109 | } alias_stats; | |
339d7079 | 110 | |
dd277d48 | 111 | void |
112 | dump_alias_stats (FILE *s) | |
113 | { | |
114 | fprintf (s, "\nAlias oracle query stats:\n"); | |
115 | fprintf (s, " refs_may_alias_p: " | |
116 | HOST_WIDE_INT_PRINT_DEC" disambiguations, " | |
117 | HOST_WIDE_INT_PRINT_DEC" queries\n", | |
118 | alias_stats.refs_may_alias_p_no_alias, | |
119 | alias_stats.refs_may_alias_p_no_alias | |
120 | + alias_stats.refs_may_alias_p_may_alias); | |
121 | fprintf (s, " ref_maybe_used_by_call_p: " | |
122 | HOST_WIDE_INT_PRINT_DEC" disambiguations, " | |
123 | HOST_WIDE_INT_PRINT_DEC" queries\n", | |
124 | alias_stats.ref_maybe_used_by_call_p_no_alias, | |
125 | alias_stats.refs_may_alias_p_no_alias | |
126 | + alias_stats.ref_maybe_used_by_call_p_may_alias); | |
127 | fprintf (s, " call_may_clobber_ref_p: " | |
128 | HOST_WIDE_INT_PRINT_DEC" disambiguations, " | |
129 | HOST_WIDE_INT_PRINT_DEC" queries\n", | |
130 | alias_stats.call_may_clobber_ref_p_no_alias, | |
131 | alias_stats.call_may_clobber_ref_p_no_alias | |
132 | + alias_stats.call_may_clobber_ref_p_may_alias); | |
133 | } | |
134 | ||
135 | ||
136 | /* Return true, if dereferencing PTR may alias with a global variable. */ | |
4ee9c684 | 137 | |
dd277d48 | 138 | bool |
139 | ptr_deref_may_alias_global_p (tree ptr) | |
4ee9c684 | 140 | { |
dd277d48 | 141 | struct ptr_info_def *pi; |
4fb5e5ca | 142 | |
dd277d48 | 143 | /* If we end up with a pointer constant here that may point |
144 | to global memory. */ | |
145 | if (TREE_CODE (ptr) != SSA_NAME) | |
146 | return true; | |
4ee9c684 | 147 | |
dd277d48 | 148 | pi = SSA_NAME_PTR_INFO (ptr); |
4ee9c684 | 149 | |
dd277d48 | 150 | /* If we do not have points-to information for this variable, |
151 | we have to punt. */ | |
152 | if (!pi) | |
153 | return true; | |
4ee9c684 | 154 | |
2a3ebafa | 155 | /* ??? This does not use TBAA to prune globals ptr may not access. */ |
dd277d48 | 156 | return pt_solution_includes_global (&pi->pt); |
4ee9c684 | 157 | } |
158 | ||
2a3ebafa | 159 | /* Return true if dereferencing PTR may alias DECL. |
160 | The caller is responsible for applying TBAA to see if PTR | |
161 | may access DECL at all. */ | |
4ee9c684 | 162 | |
dd277d48 | 163 | static bool |
164 | ptr_deref_may_alias_decl_p (tree ptr, tree decl) | |
4ee9c684 | 165 | { |
dd277d48 | 166 | struct ptr_info_def *pi; |
f7d118a9 | 167 | |
2760c0e3 | 168 | /* Conversions are irrelevant for points-to information and |
169 | data-dependence analysis can feed us those. */ | |
170 | STRIP_NOPS (ptr); | |
171 | ||
172 | /* Anything we do not explicilty handle aliases. */ | |
173 | if ((TREE_CODE (ptr) != SSA_NAME | |
174 | && TREE_CODE (ptr) != ADDR_EXPR | |
175 | && TREE_CODE (ptr) != POINTER_PLUS_EXPR) | |
176 | || !POINTER_TYPE_P (TREE_TYPE (ptr)) | |
177 | || (TREE_CODE (decl) != VAR_DECL | |
178 | && TREE_CODE (decl) != PARM_DECL | |
179 | && TREE_CODE (decl) != RESULT_DECL)) | |
9c01641d | 180 | return true; |
2fd0b5dc | 181 | |
2760c0e3 | 182 | /* Disregard pointer offsetting. */ |
183 | if (TREE_CODE (ptr) == POINTER_PLUS_EXPR) | |
184 | { | |
185 | do | |
186 | { | |
187 | ptr = TREE_OPERAND (ptr, 0); | |
188 | } | |
189 | while (TREE_CODE (ptr) == POINTER_PLUS_EXPR); | |
190 | return ptr_deref_may_alias_decl_p (ptr, decl); | |
191 | } | |
192 | ||
047fdd47 | 193 | /* ADDR_EXPR pointers either just offset another pointer or directly |
194 | specify the pointed-to set. */ | |
195 | if (TREE_CODE (ptr) == ADDR_EXPR) | |
196 | { | |
197 | tree base = get_base_address (TREE_OPERAND (ptr, 0)); | |
198 | if (base | |
2622064f | 199 | && (TREE_CODE (base) == MEM_REF |
200 | || TREE_CODE (base) == TARGET_MEM_REF)) | |
047fdd47 | 201 | ptr = TREE_OPERAND (base, 0); |
202 | else if (base | |
2622064f | 203 | && DECL_P (base)) |
7f2d9047 | 204 | return base == decl; |
047fdd47 | 205 | else if (base |
206 | && CONSTANT_CLASS_P (base)) | |
207 | return false; | |
208 | else | |
209 | return true; | |
210 | } | |
211 | ||
2760c0e3 | 212 | /* Non-aliased variables can not be pointed to. */ |
213 | if (!may_be_aliased (decl)) | |
214 | return false; | |
047fdd47 | 215 | |
dd277d48 | 216 | /* If we do not have useful points-to information for this pointer |
217 | we cannot disambiguate anything else. */ | |
218 | pi = SSA_NAME_PTR_INFO (ptr); | |
219 | if (!pi) | |
2fd0b5dc | 220 | return true; |
221 | ||
dd277d48 | 222 | return pt_solution_includes (&pi->pt, decl); |
2fd0b5dc | 223 | } |
4ee9c684 | 224 | |
2a3ebafa | 225 | /* Return true if dereferenced PTR1 and PTR2 may alias. |
226 | The caller is responsible for applying TBAA to see if accesses | |
227 | through PTR1 and PTR2 may conflict at all. */ | |
4ee9c684 | 228 | |
2760c0e3 | 229 | bool |
dd277d48 | 230 | ptr_derefs_may_alias_p (tree ptr1, tree ptr2) |
4ee9c684 | 231 | { |
dd277d48 | 232 | struct ptr_info_def *pi1, *pi2; |
4ee9c684 | 233 | |
2760c0e3 | 234 | /* Conversions are irrelevant for points-to information and |
235 | data-dependence analysis can feed us those. */ | |
236 | STRIP_NOPS (ptr1); | |
237 | STRIP_NOPS (ptr2); | |
238 | ||
2760c0e3 | 239 | /* Disregard pointer offsetting. */ |
240 | if (TREE_CODE (ptr1) == POINTER_PLUS_EXPR) | |
241 | { | |
242 | do | |
243 | { | |
244 | ptr1 = TREE_OPERAND (ptr1, 0); | |
245 | } | |
246 | while (TREE_CODE (ptr1) == POINTER_PLUS_EXPR); | |
247 | return ptr_derefs_may_alias_p (ptr1, ptr2); | |
248 | } | |
249 | if (TREE_CODE (ptr2) == POINTER_PLUS_EXPR) | |
250 | { | |
251 | do | |
252 | { | |
253 | ptr2 = TREE_OPERAND (ptr2, 0); | |
254 | } | |
255 | while (TREE_CODE (ptr2) == POINTER_PLUS_EXPR); | |
256 | return ptr_derefs_may_alias_p (ptr1, ptr2); | |
257 | } | |
f85fb819 | 258 | |
047fdd47 | 259 | /* ADDR_EXPR pointers either just offset another pointer or directly |
260 | specify the pointed-to set. */ | |
261 | if (TREE_CODE (ptr1) == ADDR_EXPR) | |
262 | { | |
263 | tree base = get_base_address (TREE_OPERAND (ptr1, 0)); | |
264 | if (base | |
2622064f | 265 | && (TREE_CODE (base) == MEM_REF |
266 | || TREE_CODE (base) == TARGET_MEM_REF)) | |
80b4d93e | 267 | return ptr_derefs_may_alias_p (TREE_OPERAND (base, 0), ptr2); |
047fdd47 | 268 | else if (base |
2622064f | 269 | && DECL_P (base)) |
047fdd47 | 270 | return ptr_deref_may_alias_decl_p (ptr2, base); |
271 | else | |
272 | return true; | |
273 | } | |
274 | if (TREE_CODE (ptr2) == ADDR_EXPR) | |
275 | { | |
276 | tree base = get_base_address (TREE_OPERAND (ptr2, 0)); | |
277 | if (base | |
2622064f | 278 | && (TREE_CODE (base) == MEM_REF |
279 | || TREE_CODE (base) == TARGET_MEM_REF)) | |
80b4d93e | 280 | return ptr_derefs_may_alias_p (ptr1, TREE_OPERAND (base, 0)); |
047fdd47 | 281 | else if (base |
2622064f | 282 | && DECL_P (base)) |
047fdd47 | 283 | return ptr_deref_may_alias_decl_p (ptr1, base); |
284 | else | |
285 | return true; | |
286 | } | |
287 | ||
80b4d93e | 288 | /* From here we require SSA name pointers. Anything else aliases. */ |
289 | if (TREE_CODE (ptr1) != SSA_NAME | |
290 | || TREE_CODE (ptr2) != SSA_NAME | |
291 | || !POINTER_TYPE_P (TREE_TYPE (ptr1)) | |
292 | || !POINTER_TYPE_P (TREE_TYPE (ptr2))) | |
293 | return true; | |
294 | ||
dd277d48 | 295 | /* We may end up with two empty points-to solutions for two same pointers. |
296 | In this case we still want to say both pointers alias, so shortcut | |
297 | that here. */ | |
298 | if (ptr1 == ptr2) | |
299 | return true; | |
81d08033 | 300 | |
dd277d48 | 301 | /* If we do not have useful points-to information for either pointer |
302 | we cannot disambiguate anything else. */ | |
303 | pi1 = SSA_NAME_PTR_INFO (ptr1); | |
304 | pi2 = SSA_NAME_PTR_INFO (ptr2); | |
305 | if (!pi1 || !pi2) | |
306 | return true; | |
81d08033 | 307 | |
2a3ebafa | 308 | /* ??? This does not use TBAA to prune decls from the intersection |
309 | that not both pointers may access. */ | |
dd277d48 | 310 | return pt_solutions_intersect (&pi1->pt, &pi2->pt); |
81d08033 | 311 | } |
312 | ||
047fdd47 | 313 | /* Return true if dereferencing PTR may alias *REF. |
314 | The caller is responsible for applying TBAA to see if PTR | |
315 | may access *REF at all. */ | |
316 | ||
317 | static bool | |
318 | ptr_deref_may_alias_ref_p_1 (tree ptr, ao_ref *ref) | |
319 | { | |
320 | tree base = ao_ref_base (ref); | |
321 | ||
2622064f | 322 | if (TREE_CODE (base) == MEM_REF |
323 | || TREE_CODE (base) == TARGET_MEM_REF) | |
047fdd47 | 324 | return ptr_derefs_may_alias_p (ptr, TREE_OPERAND (base, 0)); |
2622064f | 325 | else if (DECL_P (base)) |
047fdd47 | 326 | return ptr_deref_may_alias_decl_p (ptr, base); |
327 | ||
328 | return true; | |
329 | } | |
330 | ||
8763c223 | 331 | /* Return true whether REF may refer to global memory. */ |
332 | ||
333 | bool | |
334 | ref_may_alias_global_p (tree ref) | |
335 | { | |
336 | tree base = get_base_address (ref); | |
337 | if (DECL_P (base)) | |
338 | return is_global_var (base); | |
339 | else if (TREE_CODE (base) == MEM_REF | |
340 | || TREE_CODE (base) == TARGET_MEM_REF) | |
341 | return ptr_deref_may_alias_global_p (TREE_OPERAND (base, 0)); | |
342 | return true; | |
343 | } | |
344 | ||
345 | /* Return true whether STMT may clobber global memory. */ | |
346 | ||
347 | bool | |
348 | stmt_may_clobber_global_p (gimple stmt) | |
349 | { | |
350 | tree lhs; | |
351 | ||
352 | if (!gimple_vdef (stmt)) | |
353 | return false; | |
354 | ||
355 | /* ??? We can ask the oracle whether an artificial pointer | |
356 | dereference with a pointer with points-to information covering | |
357 | all global memory (what about non-address taken memory?) maybe | |
358 | clobbered by this call. As there is at the moment no convenient | |
359 | way of doing that without generating garbage do some manual | |
360 | checking instead. | |
361 | ??? We could make a NULL ao_ref argument to the various | |
362 | predicates special, meaning any global memory. */ | |
363 | ||
364 | switch (gimple_code (stmt)) | |
365 | { | |
366 | case GIMPLE_ASSIGN: | |
367 | lhs = gimple_assign_lhs (stmt); | |
368 | return (TREE_CODE (lhs) != SSA_NAME | |
369 | && ref_may_alias_global_p (lhs)); | |
370 | case GIMPLE_CALL: | |
371 | return true; | |
372 | default: | |
373 | return true; | |
374 | } | |
375 | } | |
376 | ||
4ee9c684 | 377 | |
378 | /* Dump alias information on FILE. */ | |
379 | ||
380 | void | |
381 | dump_alias_info (FILE *file) | |
382 | { | |
2aac21c5 | 383 | unsigned i; |
4ee9c684 | 384 | const char *funcname |
5135beeb | 385 | = lang_hooks.decl_printable_name (current_function_decl, 2); |
a55dc2cd | 386 | tree var; |
4ee9c684 | 387 | |
dd277d48 | 388 | fprintf (file, "\n\nAlias information for %s\n\n", funcname); |
81d08033 | 389 | |
390 | fprintf (file, "Aliased symbols\n\n"); | |
48e1416a | 391 | |
2aac21c5 | 392 | FOR_EACH_LOCAL_DECL (cfun, i, var) |
81d08033 | 393 | { |
81d08033 | 394 | if (may_be_aliased (var)) |
395 | dump_variable (file, var); | |
396 | } | |
397 | ||
7f81b5ee | 398 | fprintf (file, "\nCall clobber information\n"); |
399 | ||
400 | fprintf (file, "\nESCAPED"); | |
401 | dump_points_to_solution (file, &cfun->gimple_df->escaped); | |
7f81b5ee | 402 | |
403 | fprintf (file, "\n\nFlow-insensitive points-to information\n\n"); | |
81d08033 | 404 | |
81d08033 | 405 | for (i = 1; i < num_ssa_names; i++) |
406 | { | |
407 | tree ptr = ssa_name (i); | |
a48b1470 | 408 | struct ptr_info_def *pi; |
48e1416a | 409 | |
dd277d48 | 410 | if (ptr == NULL_TREE |
0cf78115 | 411 | || !POINTER_TYPE_P (TREE_TYPE (ptr)) |
dd277d48 | 412 | || SSA_NAME_IN_FREE_LIST (ptr)) |
a48b1470 | 413 | continue; |
414 | ||
415 | pi = SSA_NAME_PTR_INFO (ptr); | |
dd277d48 | 416 | if (pi) |
81d08033 | 417 | dump_points_to_info_for (file, ptr); |
418 | } | |
4ee9c684 | 419 | |
4ee9c684 | 420 | fprintf (file, "\n"); |
421 | } | |
422 | ||
423 | ||
424 | /* Dump alias information on stderr. */ | |
425 | ||
4b987fac | 426 | DEBUG_FUNCTION void |
4ee9c684 | 427 | debug_alias_info (void) |
428 | { | |
429 | dump_alias_info (stderr); | |
430 | } | |
431 | ||
432 | ||
7f81b5ee | 433 | /* Dump the points-to set *PT into FILE. */ |
4ee9c684 | 434 | |
d793732c | 435 | void |
7f81b5ee | 436 | dump_points_to_solution (FILE *file, struct pt_solution *pt) |
4ee9c684 | 437 | { |
7f81b5ee | 438 | if (pt->anything) |
439 | fprintf (file, ", points-to anything"); | |
4ee9c684 | 440 | |
7f81b5ee | 441 | if (pt->nonlocal) |
442 | fprintf (file, ", points-to non-local"); | |
4ee9c684 | 443 | |
7f81b5ee | 444 | if (pt->escaped) |
445 | fprintf (file, ", points-to escaped"); | |
446 | ||
1a981e1a | 447 | if (pt->ipa_escaped) |
448 | fprintf (file, ", points-to unit escaped"); | |
449 | ||
7f81b5ee | 450 | if (pt->null) |
451 | fprintf (file, ", points-to NULL"); | |
452 | ||
453 | if (pt->vars) | |
4ee9c684 | 454 | { |
7f81b5ee | 455 | fprintf (file, ", points-to vars: "); |
456 | dump_decl_set (file, pt->vars); | |
420582bc | 457 | if (pt->vars_contains_nonlocal |
458 | && pt->vars_contains_escaped_heap) | |
459 | fprintf (file, " (nonlocal, escaped heap)"); | |
460 | else if (pt->vars_contains_nonlocal | |
461 | && pt->vars_contains_escaped) | |
462 | fprintf (file, " (nonlocal, escaped)"); | |
463 | else if (pt->vars_contains_nonlocal) | |
464 | fprintf (file, " (nonlocal)"); | |
465 | else if (pt->vars_contains_escaped_heap) | |
466 | fprintf (file, " (escaped heap)"); | |
467 | else if (pt->vars_contains_escaped) | |
468 | fprintf (file, " (escaped)"); | |
7f81b5ee | 469 | } |
470 | } | |
4ee9c684 | 471 | |
c7d89805 | 472 | |
473 | /* Unified dump function for pt_solution. */ | |
474 | ||
475 | DEBUG_FUNCTION void | |
476 | debug (pt_solution &ref) | |
477 | { | |
478 | dump_points_to_solution (stderr, &ref); | |
479 | } | |
480 | ||
481 | DEBUG_FUNCTION void | |
482 | debug (pt_solution *ptr) | |
483 | { | |
484 | if (ptr) | |
485 | debug (*ptr); | |
486 | else | |
487 | fprintf (stderr, "<nil>\n"); | |
488 | } | |
489 | ||
490 | ||
7f81b5ee | 491 | /* Dump points-to information for SSA_NAME PTR into FILE. */ |
4ee9c684 | 492 | |
7f81b5ee | 493 | void |
494 | dump_points_to_info_for (FILE *file, tree ptr) | |
495 | { | |
496 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr); | |
4ee9c684 | 497 | |
7f81b5ee | 498 | print_generic_expr (file, ptr, dump_flags); |
1e1a4c8c | 499 | |
7f81b5ee | 500 | if (pi) |
501 | dump_points_to_solution (file, &pi->pt); | |
502 | else | |
503 | fprintf (file, ", points-to anything"); | |
4ee9c684 | 504 | |
505 | fprintf (file, "\n"); | |
506 | } | |
507 | ||
508 | ||
d793732c | 509 | /* Dump points-to information for VAR into stderr. */ |
510 | ||
4b987fac | 511 | DEBUG_FUNCTION void |
d793732c | 512 | debug_points_to_info_for (tree var) |
513 | { | |
514 | dump_points_to_info_for (stderr, var); | |
515 | } | |
516 | ||
3918bd18 | 517 | |
518 | /* Initializes the alias-oracle reference representation *R from REF. */ | |
519 | ||
520 | void | |
521 | ao_ref_init (ao_ref *r, tree ref) | |
522 | { | |
523 | r->ref = ref; | |
524 | r->base = NULL_TREE; | |
525 | r->offset = 0; | |
526 | r->size = -1; | |
527 | r->max_size = -1; | |
528 | r->ref_alias_set = -1; | |
529 | r->base_alias_set = -1; | |
3787db52 | 530 | r->volatile_p = ref ? TREE_THIS_VOLATILE (ref) : false; |
3918bd18 | 531 | } |
532 | ||
533 | /* Returns the base object of the memory reference *REF. */ | |
534 | ||
535 | tree | |
536 | ao_ref_base (ao_ref *ref) | |
537 | { | |
538 | if (ref->base) | |
539 | return ref->base; | |
540 | ref->base = get_ref_base_and_extent (ref->ref, &ref->offset, &ref->size, | |
541 | &ref->max_size); | |
542 | return ref->base; | |
543 | } | |
544 | ||
545 | /* Returns the base object alias set of the memory reference *REF. */ | |
546 | ||
182cf5a9 | 547 | static alias_set_type |
3918bd18 | 548 | ao_ref_base_alias_set (ao_ref *ref) |
549 | { | |
182cf5a9 | 550 | tree base_ref; |
3918bd18 | 551 | if (ref->base_alias_set != -1) |
552 | return ref->base_alias_set; | |
182cf5a9 | 553 | if (!ref->ref) |
554 | return 0; | |
555 | base_ref = ref->ref; | |
556 | while (handled_component_p (base_ref)) | |
557 | base_ref = TREE_OPERAND (base_ref, 0); | |
558 | ref->base_alias_set = get_alias_set (base_ref); | |
3918bd18 | 559 | return ref->base_alias_set; |
560 | } | |
561 | ||
562 | /* Returns the reference alias set of the memory reference *REF. */ | |
563 | ||
564 | alias_set_type | |
565 | ao_ref_alias_set (ao_ref *ref) | |
566 | { | |
567 | if (ref->ref_alias_set != -1) | |
568 | return ref->ref_alias_set; | |
569 | ref->ref_alias_set = get_alias_set (ref->ref); | |
570 | return ref->ref_alias_set; | |
571 | } | |
572 | ||
134899ac | 573 | /* Init an alias-oracle reference representation from a gimple pointer |
234f1f79 | 574 | PTR and a gimple size SIZE in bytes. If SIZE is NULL_TREE then the |
134899ac | 575 | size is assumed to be unknown. The access is assumed to be only |
576 | to or after of the pointer target, not before it. */ | |
577 | ||
578 | void | |
579 | ao_ref_init_from_ptr_and_size (ao_ref *ref, tree ptr, tree size) | |
580 | { | |
d1603825 | 581 | HOST_WIDE_INT t, extra_offset = 0; |
134899ac | 582 | ref->ref = NULL_TREE; |
4e9e79c0 | 583 | if (TREE_CODE (ptr) == SSA_NAME) |
584 | { | |
585 | gimple stmt = SSA_NAME_DEF_STMT (ptr); | |
586 | if (gimple_assign_single_p (stmt) | |
587 | && gimple_assign_rhs_code (stmt) == ADDR_EXPR) | |
588 | ptr = gimple_assign_rhs1 (stmt); | |
e3ac92d2 | 589 | else if (is_gimple_assign (stmt) |
590 | && gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR | |
234f1f79 | 591 | && TREE_CODE (gimple_assign_rhs2 (stmt)) == INTEGER_CST) |
e3ac92d2 | 592 | { |
593 | ptr = gimple_assign_rhs1 (stmt); | |
234f1f79 | 594 | extra_offset = BITS_PER_UNIT |
595 | * int_cst_value (gimple_assign_rhs2 (stmt)); | |
e3ac92d2 | 596 | } |
4e9e79c0 | 597 | } |
598 | ||
134899ac | 599 | if (TREE_CODE (ptr) == ADDR_EXPR) |
d1603825 | 600 | { |
601 | ref->base = get_addr_base_and_unit_offset (TREE_OPERAND (ptr, 0), &t); | |
602 | if (ref->base) | |
603 | ref->offset = BITS_PER_UNIT * t; | |
604 | else | |
605 | { | |
606 | size = NULL_TREE; | |
607 | ref->offset = 0; | |
608 | ref->base = get_base_address (TREE_OPERAND (ptr, 0)); | |
609 | } | |
610 | } | |
134899ac | 611 | else |
612 | { | |
182cf5a9 | 613 | ref->base = build2 (MEM_REF, char_type_node, |
2512209b | 614 | ptr, null_pointer_node); |
134899ac | 615 | ref->offset = 0; |
616 | } | |
e3ac92d2 | 617 | ref->offset += extra_offset; |
134899ac | 618 | if (size |
35ec552a | 619 | && tree_fits_shwi_p (size) |
e3ac92d2 | 620 | && TREE_INT_CST_LOW (size) * BITS_PER_UNIT / BITS_PER_UNIT |
621 | == TREE_INT_CST_LOW (size)) | |
622 | ref->max_size = ref->size = TREE_INT_CST_LOW (size) * BITS_PER_UNIT; | |
134899ac | 623 | else |
624 | ref->max_size = ref->size = -1; | |
625 | ref->ref_alias_set = 0; | |
626 | ref->base_alias_set = 0; | |
3787db52 | 627 | ref->volatile_p = false; |
134899ac | 628 | } |
629 | ||
dd277d48 | 630 | /* Return 1 if TYPE1 and TYPE2 are to be considered equivalent for the |
631 | purpose of TBAA. Return 0 if they are distinct and -1 if we cannot | |
632 | decide. */ | |
d793732c | 633 | |
dd277d48 | 634 | static inline int |
635 | same_type_for_tbaa (tree type1, tree type2) | |
636 | { | |
637 | type1 = TYPE_MAIN_VARIANT (type1); | |
638 | type2 = TYPE_MAIN_VARIANT (type2); | |
4ee9c684 | 639 | |
dd277d48 | 640 | /* If we would have to do structural comparison bail out. */ |
641 | if (TYPE_STRUCTURAL_EQUALITY_P (type1) | |
642 | || TYPE_STRUCTURAL_EQUALITY_P (type2)) | |
643 | return -1; | |
644 | ||
645 | /* Compare the canonical types. */ | |
646 | if (TYPE_CANONICAL (type1) == TYPE_CANONICAL (type2)) | |
647 | return 1; | |
648 | ||
4b4d1513 | 649 | /* ??? Array types are not properly unified in all cases as we have |
dd277d48 | 650 | spurious changes in the index types for example. Removing this |
651 | causes all sorts of problems with the Fortran frontend. */ | |
652 | if (TREE_CODE (type1) == ARRAY_TYPE | |
653 | && TREE_CODE (type2) == ARRAY_TYPE) | |
654 | return -1; | |
655 | ||
102bfc9c | 656 | /* ??? In Ada, an lvalue of an unconstrained type can be used to access an |
657 | object of one of its constrained subtypes, e.g. when a function with an | |
658 | unconstrained parameter passed by reference is called on an object and | |
659 | inlined. But, even in the case of a fixed size, type and subtypes are | |
660 | not equivalent enough as to share the same TYPE_CANONICAL, since this | |
661 | would mean that conversions between them are useless, whereas they are | |
662 | not (e.g. type and subtypes can have different modes). So, in the end, | |
663 | they are only guaranteed to have the same alias set. */ | |
664 | if (get_alias_set (type1) == get_alias_set (type2)) | |
4b4d1513 | 665 | return -1; |
666 | ||
dd277d48 | 667 | /* The types are known to be not equal. */ |
668 | return 0; | |
669 | } | |
670 | ||
671 | /* Determine if the two component references REF1 and REF2 which are | |
672 | based on access types TYPE1 and TYPE2 and of which at least one is based | |
ac30e3b2 | 673 | on an indirect reference may alias. REF2 is the only one that can |
674 | be a decl in which case REF2_IS_DECL is true. | |
675 | REF1_ALIAS_SET, BASE1_ALIAS_SET, REF2_ALIAS_SET and BASE2_ALIAS_SET | |
676 | are the respective alias sets. */ | |
dd277d48 | 677 | |
678 | static bool | |
0d2f7431 | 679 | aliasing_component_refs_p (tree ref1, |
ac30e3b2 | 680 | alias_set_type ref1_alias_set, |
681 | alias_set_type base1_alias_set, | |
a42ce2cc | 682 | HOST_WIDE_INT offset1, HOST_WIDE_INT max_size1, |
0d2f7431 | 683 | tree ref2, |
ac30e3b2 | 684 | alias_set_type ref2_alias_set, |
685 | alias_set_type base2_alias_set, | |
686 | HOST_WIDE_INT offset2, HOST_WIDE_INT max_size2, | |
687 | bool ref2_is_decl) | |
dd277d48 | 688 | { |
689 | /* If one reference is a component references through pointers try to find a | |
690 | common base and apply offset based disambiguation. This handles | |
691 | for example | |
692 | struct A { int i; int j; } *q; | |
693 | struct B { struct A a; int k; } *p; | |
694 | disambiguating q->i and p->a.j. */ | |
0d2f7431 | 695 | tree base1, base2; |
696 | tree type1, type2; | |
dd277d48 | 697 | tree *refp; |
698 | int same_p; | |
699 | ||
0d2f7431 | 700 | /* Choose bases and base types to search for. */ |
701 | base1 = ref1; | |
702 | while (handled_component_p (base1)) | |
703 | base1 = TREE_OPERAND (base1, 0); | |
704 | type1 = TREE_TYPE (base1); | |
705 | base2 = ref2; | |
706 | while (handled_component_p (base2)) | |
707 | base2 = TREE_OPERAND (base2, 0); | |
708 | type2 = TREE_TYPE (base2); | |
709 | ||
dd277d48 | 710 | /* Now search for the type1 in the access path of ref2. This |
711 | would be a common base for doing offset based disambiguation on. */ | |
bc3c318e | 712 | refp = &ref2; |
dd277d48 | 713 | while (handled_component_p (*refp) |
714 | && same_type_for_tbaa (TREE_TYPE (*refp), type1) == 0) | |
715 | refp = &TREE_OPERAND (*refp, 0); | |
716 | same_p = same_type_for_tbaa (TREE_TYPE (*refp), type1); | |
717 | /* If we couldn't compare types we have to bail out. */ | |
718 | if (same_p == -1) | |
719 | return true; | |
720 | else if (same_p == 1) | |
721 | { | |
722 | HOST_WIDE_INT offadj, sztmp, msztmp; | |
723 | get_ref_base_and_extent (*refp, &offadj, &sztmp, &msztmp); | |
724 | offset2 -= offadj; | |
0d2f7431 | 725 | get_ref_base_and_extent (base1, &offadj, &sztmp, &msztmp); |
726 | offset1 -= offadj; | |
dd277d48 | 727 | return ranges_overlap_p (offset1, max_size1, offset2, max_size2); |
728 | } | |
729 | /* If we didn't find a common base, try the other way around. */ | |
bc3c318e | 730 | refp = &ref1; |
dd277d48 | 731 | while (handled_component_p (*refp) |
732 | && same_type_for_tbaa (TREE_TYPE (*refp), type2) == 0) | |
733 | refp = &TREE_OPERAND (*refp, 0); | |
734 | same_p = same_type_for_tbaa (TREE_TYPE (*refp), type2); | |
735 | /* If we couldn't compare types we have to bail out. */ | |
736 | if (same_p == -1) | |
737 | return true; | |
738 | else if (same_p == 1) | |
739 | { | |
740 | HOST_WIDE_INT offadj, sztmp, msztmp; | |
741 | get_ref_base_and_extent (*refp, &offadj, &sztmp, &msztmp); | |
742 | offset1 -= offadj; | |
0d2f7431 | 743 | get_ref_base_and_extent (base2, &offadj, &sztmp, &msztmp); |
744 | offset2 -= offadj; | |
dd277d48 | 745 | return ranges_overlap_p (offset1, max_size1, offset2, max_size2); |
746 | } | |
ac30e3b2 | 747 | |
4b4d1513 | 748 | /* If we have two type access paths B1.path1 and B2.path2 they may |
ac30e3b2 | 749 | only alias if either B1 is in B2.path2 or B2 is in B1.path1. |
750 | But we can still have a path that goes B1.path1...B2.path2 with | |
751 | a part that we do not see. So we can only disambiguate now | |
752 | if there is no B2 in the tail of path1 and no B1 on the | |
753 | tail of path2. */ | |
754 | if (base1_alias_set == ref2_alias_set | |
755 | || alias_set_subset_of (base1_alias_set, ref2_alias_set)) | |
756 | return true; | |
757 | /* If this is ptr vs. decl then we know there is no ptr ... decl path. */ | |
758 | if (!ref2_is_decl) | |
759 | return (base2_alias_set == ref1_alias_set | |
760 | || alias_set_subset_of (base2_alias_set, ref1_alias_set)); | |
4b4d1513 | 761 | return false; |
dd277d48 | 762 | } |
763 | ||
740a2cb6 | 764 | /* Return true if we can determine that component references REF1 and REF2, |
765 | that are within a common DECL, cannot overlap. */ | |
766 | ||
767 | static bool | |
768 | nonoverlapping_component_refs_of_decl_p (tree ref1, tree ref2) | |
769 | { | |
d70aebca | 770 | stack_vec<tree, 16> component_refs1; |
771 | stack_vec<tree, 16> component_refs2; | |
740a2cb6 | 772 | |
773 | /* Create the stack of handled components for REF1. */ | |
774 | while (handled_component_p (ref1)) | |
775 | { | |
776 | component_refs1.safe_push (ref1); | |
777 | ref1 = TREE_OPERAND (ref1, 0); | |
778 | } | |
779 | if (TREE_CODE (ref1) == MEM_REF) | |
780 | { | |
781 | if (!integer_zerop (TREE_OPERAND (ref1, 1))) | |
782 | goto may_overlap; | |
783 | ref1 = TREE_OPERAND (TREE_OPERAND (ref1, 0), 0); | |
784 | } | |
785 | ||
786 | /* Create the stack of handled components for REF2. */ | |
787 | while (handled_component_p (ref2)) | |
788 | { | |
789 | component_refs2.safe_push (ref2); | |
790 | ref2 = TREE_OPERAND (ref2, 0); | |
791 | } | |
792 | if (TREE_CODE (ref2) == MEM_REF) | |
793 | { | |
794 | if (!integer_zerop (TREE_OPERAND (ref2, 1))) | |
795 | goto may_overlap; | |
796 | ref2 = TREE_OPERAND (TREE_OPERAND (ref2, 0), 0); | |
797 | } | |
798 | ||
799 | /* We must have the same base DECL. */ | |
800 | gcc_assert (ref1 == ref2); | |
801 | ||
802 | /* Pop the stacks in parallel and examine the COMPONENT_REFs of the same | |
803 | rank. This is sufficient because we start from the same DECL and you | |
804 | cannot reference several fields at a time with COMPONENT_REFs (unlike | |
805 | with ARRAY_RANGE_REFs for arrays) so you always need the same number | |
806 | of them to access a sub-component, unless you're in a union, in which | |
807 | case the return value will precisely be false. */ | |
808 | while (true) | |
809 | { | |
810 | do | |
811 | { | |
812 | if (component_refs1.is_empty ()) | |
813 | goto may_overlap; | |
814 | ref1 = component_refs1.pop (); | |
815 | } | |
816 | while (!RECORD_OR_UNION_TYPE_P (TREE_TYPE (TREE_OPERAND (ref1, 0)))); | |
817 | ||
818 | do | |
819 | { | |
820 | if (component_refs2.is_empty ()) | |
821 | goto may_overlap; | |
822 | ref2 = component_refs2.pop (); | |
823 | } | |
824 | while (!RECORD_OR_UNION_TYPE_P (TREE_TYPE (TREE_OPERAND (ref2, 0)))); | |
825 | ||
826 | /* Beware of BIT_FIELD_REF. */ | |
827 | if (TREE_CODE (ref1) != COMPONENT_REF | |
828 | || TREE_CODE (ref2) != COMPONENT_REF) | |
829 | goto may_overlap; | |
830 | ||
831 | tree field1 = TREE_OPERAND (ref1, 1); | |
832 | tree field2 = TREE_OPERAND (ref2, 1); | |
833 | ||
834 | /* ??? We cannot simply use the type of operand #0 of the refs here | |
835 | as the Fortran compiler smuggles type punning into COMPONENT_REFs | |
836 | for common blocks instead of using unions like everyone else. */ | |
837 | tree type1 = TYPE_MAIN_VARIANT (DECL_CONTEXT (field1)); | |
838 | tree type2 = TYPE_MAIN_VARIANT (DECL_CONTEXT (field2)); | |
839 | ||
840 | /* We cannot disambiguate fields in a union or qualified union. */ | |
841 | if (type1 != type2 || TREE_CODE (type1) != RECORD_TYPE) | |
842 | goto may_overlap; | |
843 | ||
11ad02c6 | 844 | /* Different fields of the same record type cannot overlap. |
845 | ??? Bitfields can overlap at RTL level so punt on them. */ | |
740a2cb6 | 846 | if (field1 != field2) |
847 | { | |
848 | component_refs1.release (); | |
849 | component_refs2.release (); | |
11ad02c6 | 850 | return !(DECL_BIT_FIELD (field1) && DECL_BIT_FIELD (field2)); |
740a2cb6 | 851 | } |
852 | } | |
853 | ||
854 | may_overlap: | |
855 | component_refs1.release (); | |
856 | component_refs2.release (); | |
857 | return false; | |
858 | } | |
859 | ||
dd277d48 | 860 | /* Return true if two memory references based on the variables BASE1 |
077ad5ad | 861 | and BASE2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and |
740a2cb6 | 862 | [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. REF1 and REF2 |
863 | if non-NULL are the complete memory reference trees. */ | |
dd277d48 | 864 | |
865 | static bool | |
740a2cb6 | 866 | decl_refs_may_alias_p (tree ref1, tree base1, |
dd277d48 | 867 | HOST_WIDE_INT offset1, HOST_WIDE_INT max_size1, |
740a2cb6 | 868 | tree ref2, tree base2, |
dd277d48 | 869 | HOST_WIDE_INT offset2, HOST_WIDE_INT max_size2) |
4ee9c684 | 870 | { |
2622064f | 871 | gcc_checking_assert (DECL_P (base1) && DECL_P (base2)); |
4ee9c684 | 872 | |
dd277d48 | 873 | /* If both references are based on different variables, they cannot alias. */ |
7f2d9047 | 874 | if (base1 != base2) |
dd277d48 | 875 | return false; |
4ee9c684 | 876 | |
dd277d48 | 877 | /* If both references are based on the same variable, they cannot alias if |
878 | the accesses do not overlap. */ | |
740a2cb6 | 879 | if (!ranges_overlap_p (offset1, max_size1, offset2, max_size2)) |
880 | return false; | |
881 | ||
882 | /* For components with variable position, the above test isn't sufficient, | |
883 | so we disambiguate component references manually. */ | |
884 | if (ref1 && ref2 | |
885 | && handled_component_p (ref1) && handled_component_p (ref2) | |
886 | && nonoverlapping_component_refs_of_decl_p (ref1, ref2)) | |
887 | return false; | |
888 | ||
889 | return true; | |
dd277d48 | 890 | } |
891 | ||
892 | /* Return true if an indirect reference based on *PTR1 constrained | |
077ad5ad | 893 | to [OFFSET1, OFFSET1 + MAX_SIZE1) may alias a variable based on BASE2 |
894 | constrained to [OFFSET2, OFFSET2 + MAX_SIZE2). *PTR1 and BASE2 have | |
dd277d48 | 895 | the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1 |
896 | in which case they are computed on-demand. REF1 and REF2 | |
897 | if non-NULL are the complete memory reference trees. */ | |
898 | ||
899 | static bool | |
182cf5a9 | 900 | indirect_ref_may_alias_decl_p (tree ref1 ATTRIBUTE_UNUSED, tree base1, |
901 | HOST_WIDE_INT offset1, | |
902 | HOST_WIDE_INT max_size1 ATTRIBUTE_UNUSED, | |
ac30e3b2 | 903 | alias_set_type ref1_alias_set, |
dd277d48 | 904 | alias_set_type base1_alias_set, |
182cf5a9 | 905 | tree ref2 ATTRIBUTE_UNUSED, tree base2, |
dd277d48 | 906 | HOST_WIDE_INT offset2, HOST_WIDE_INT max_size2, |
ac30e3b2 | 907 | alias_set_type ref2_alias_set, |
182cf5a9 | 908 | alias_set_type base2_alias_set, bool tbaa_p) |
dd277d48 | 909 | { |
9a14ba4f | 910 | tree ptr1; |
061b1263 | 911 | tree ptrtype1, dbase2; |
7749ee1c | 912 | HOST_WIDE_INT offset1p = offset1, offset2p = offset2; |
061b1263 | 913 | HOST_WIDE_INT doffset1, doffset2; |
2622064f | 914 | double_int moff; |
915 | ||
916 | gcc_checking_assert ((TREE_CODE (base1) == MEM_REF | |
917 | || TREE_CODE (base1) == TARGET_MEM_REF) | |
918 | && DECL_P (base2)); | |
182cf5a9 | 919 | |
28daba6f | 920 | ptr1 = TREE_OPERAND (base1, 0); |
9a14ba4f | 921 | |
7749ee1c | 922 | /* The offset embedded in MEM_REFs can be negative. Bias them |
923 | so that the resulting offset adjustment is positive. */ | |
2622064f | 924 | moff = mem_ref_offset (base1); |
9a8b9e26 | 925 | moff = moff.lshift (BITS_PER_UNIT == 8 ? 3 : exact_log2 (BITS_PER_UNIT)); |
cf8f0e63 | 926 | if (moff.is_negative ()) |
927 | offset2p += (-moff).low; | |
2622064f | 928 | else |
929 | offset1p += moff.low; | |
182cf5a9 | 930 | |
dd277d48 | 931 | /* If only one reference is based on a variable, they cannot alias if |
932 | the pointer access is beyond the extent of the variable access. | |
933 | (the pointer base cannot validly point to an offset less than zero | |
934 | of the variable). | |
a07f6629 | 935 | ??? IVOPTs creates bases that do not honor this restriction, |
936 | so do not apply this optimization for TARGET_MEM_REFs. */ | |
937 | if (TREE_CODE (base1) != TARGET_MEM_REF | |
9a14ba4f | 938 | && !ranges_overlap_p (MAX (0, offset1p), -1, offset2p, max_size2)) |
dd277d48 | 939 | return false; |
a07f6629 | 940 | /* They also cannot alias if the pointer may not point to the decl. */ |
dd277d48 | 941 | if (!ptr_deref_may_alias_decl_p (ptr1, base2)) |
942 | return false; | |
943 | ||
944 | /* Disambiguations that rely on strict aliasing rules follow. */ | |
182cf5a9 | 945 | if (!flag_strict_aliasing || !tbaa_p) |
dd277d48 | 946 | return true; |
947 | ||
2622064f | 948 | ptrtype1 = TREE_TYPE (TREE_OPERAND (base1, 1)); |
182cf5a9 | 949 | |
dd277d48 | 950 | /* If the alias set for a pointer access is zero all bets are off. */ |
951 | if (base1_alias_set == -1) | |
182cf5a9 | 952 | base1_alias_set = get_deref_alias_set (ptrtype1); |
dd277d48 | 953 | if (base1_alias_set == 0) |
954 | return true; | |
955 | if (base2_alias_set == -1) | |
956 | base2_alias_set = get_alias_set (base2); | |
957 | ||
182cf5a9 | 958 | /* When we are trying to disambiguate an access with a pointer dereference |
959 | as base versus one with a decl as base we can use both the size | |
960 | of the decl and its dynamic type for extra disambiguation. | |
961 | ??? We do not know anything about the dynamic type of the decl | |
962 | other than that its alias-set contains base2_alias_set as a subset | |
963 | which does not help us here. */ | |
964 | /* As we know nothing useful about the dynamic type of the decl just | |
965 | use the usual conflict check rather than a subset test. | |
966 | ??? We could introduce -fvery-strict-aliasing when the language | |
967 | does not allow decls to have a dynamic type that differs from their | |
968 | static type. Then we can check | |
969 | !alias_set_subset_of (base1_alias_set, base2_alias_set) instead. */ | |
dd277d48 | 970 | if (base1_alias_set != base2_alias_set |
182cf5a9 | 971 | && !alias_sets_conflict_p (base1_alias_set, base2_alias_set)) |
972 | return false; | |
973 | /* If the size of the access relevant for TBAA through the pointer | |
974 | is bigger than the size of the decl we can't possibly access the | |
975 | decl via that pointer. */ | |
976 | if (DECL_SIZE (base2) && COMPLETE_TYPE_P (TREE_TYPE (ptrtype1)) | |
977 | && TREE_CODE (DECL_SIZE (base2)) == INTEGER_CST | |
978 | && TREE_CODE (TYPE_SIZE (TREE_TYPE (ptrtype1))) == INTEGER_CST | |
979 | /* ??? This in turn may run afoul when a decl of type T which is | |
980 | a member of union type U is accessed through a pointer to | |
981 | type U and sizeof T is smaller than sizeof U. */ | |
982 | && TREE_CODE (TREE_TYPE (ptrtype1)) != UNION_TYPE | |
983 | && TREE_CODE (TREE_TYPE (ptrtype1)) != QUAL_UNION_TYPE | |
984 | && tree_int_cst_lt (DECL_SIZE (base2), TYPE_SIZE (TREE_TYPE (ptrtype1)))) | |
dd277d48 | 985 | return false; |
986 | ||
061b1263 | 987 | if (!ref2) |
988 | return true; | |
989 | ||
a07f6629 | 990 | /* If the decl is accessed via a MEM_REF, reconstruct the base |
061b1263 | 991 | we can use for TBAA and an appropriately adjusted offset. */ |
992 | dbase2 = ref2; | |
993 | while (handled_component_p (dbase2)) | |
994 | dbase2 = TREE_OPERAND (dbase2, 0); | |
995 | doffset1 = offset1; | |
996 | doffset2 = offset2; | |
997 | if (TREE_CODE (dbase2) == MEM_REF | |
998 | || TREE_CODE (dbase2) == TARGET_MEM_REF) | |
999 | { | |
1000 | double_int moff = mem_ref_offset (dbase2); | |
9a8b9e26 | 1001 | moff = moff.lshift (BITS_PER_UNIT == 8 ? 3 : exact_log2 (BITS_PER_UNIT)); |
cf8f0e63 | 1002 | if (moff.is_negative ()) |
1003 | doffset1 -= (-moff).low; | |
061b1263 | 1004 | else |
1005 | doffset2 -= moff.low; | |
1006 | } | |
1007 | ||
1008 | /* If either reference is view-converted, give up now. */ | |
1009 | if (same_type_for_tbaa (TREE_TYPE (base1), TREE_TYPE (ptrtype1)) != 1 | |
5ef4302d | 1010 | || same_type_for_tbaa (TREE_TYPE (dbase2), TREE_TYPE (base2)) != 1) |
061b1263 | 1011 | return true; |
1012 | ||
1013 | /* If both references are through the same type, they do not alias | |
1014 | if the accesses do not overlap. This does extra disambiguation | |
1015 | for mixed/pointer accesses but requires strict aliasing. | |
1016 | For MEM_REFs we require that the component-ref offset we computed | |
1017 | is relative to the start of the type which we ensure by | |
1018 | comparing rvalue and access type and disregarding the constant | |
1019 | pointer offset. */ | |
1020 | if ((TREE_CODE (base1) != TARGET_MEM_REF | |
1021 | || (!TMR_INDEX (base1) && !TMR_INDEX2 (base1))) | |
1022 | && same_type_for_tbaa (TREE_TYPE (base1), TREE_TYPE (dbase2)) == 1) | |
1023 | return ranges_overlap_p (doffset1, max_size1, doffset2, max_size2); | |
1024 | ||
dd277d48 | 1025 | /* Do access-path based disambiguation. */ |
1026 | if (ref1 && ref2 | |
061b1263 | 1027 | && (handled_component_p (ref1) || handled_component_p (ref2))) |
0d2f7431 | 1028 | return aliasing_component_refs_p (ref1, |
ac30e3b2 | 1029 | ref1_alias_set, base1_alias_set, |
a42ce2cc | 1030 | offset1, max_size1, |
0d2f7431 | 1031 | ref2, |
ac30e3b2 | 1032 | ref2_alias_set, base2_alias_set, |
1033 | offset2, max_size2, true); | |
dd277d48 | 1034 | |
1035 | return true; | |
1036 | } | |
1037 | ||
1038 | /* Return true if two indirect references based on *PTR1 | |
077ad5ad | 1039 | and *PTR2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and |
1040 | [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. *PTR1 and *PTR2 have | |
dd277d48 | 1041 | the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1 |
1042 | in which case they are computed on-demand. REF1 and REF2 | |
1043 | if non-NULL are the complete memory reference trees. */ | |
1044 | ||
1045 | static bool | |
182cf5a9 | 1046 | indirect_refs_may_alias_p (tree ref1 ATTRIBUTE_UNUSED, tree base1, |
dd277d48 | 1047 | HOST_WIDE_INT offset1, HOST_WIDE_INT max_size1, |
ac30e3b2 | 1048 | alias_set_type ref1_alias_set, |
dd277d48 | 1049 | alias_set_type base1_alias_set, |
182cf5a9 | 1050 | tree ref2 ATTRIBUTE_UNUSED, tree base2, |
dd277d48 | 1051 | HOST_WIDE_INT offset2, HOST_WIDE_INT max_size2, |
ac30e3b2 | 1052 | alias_set_type ref2_alias_set, |
182cf5a9 | 1053 | alias_set_type base2_alias_set, bool tbaa_p) |
dd277d48 | 1054 | { |
9a14ba4f | 1055 | tree ptr1; |
1056 | tree ptr2; | |
182cf5a9 | 1057 | tree ptrtype1, ptrtype2; |
1058 | ||
2622064f | 1059 | gcc_checking_assert ((TREE_CODE (base1) == MEM_REF |
1060 | || TREE_CODE (base1) == TARGET_MEM_REF) | |
1061 | && (TREE_CODE (base2) == MEM_REF | |
1062 | || TREE_CODE (base2) == TARGET_MEM_REF)); | |
1063 | ||
28daba6f | 1064 | ptr1 = TREE_OPERAND (base1, 0); |
1065 | ptr2 = TREE_OPERAND (base2, 0); | |
9a14ba4f | 1066 | |
dd277d48 | 1067 | /* If both bases are based on pointers they cannot alias if they may not |
1068 | point to the same memory object or if they point to the same object | |
1069 | and the accesses do not overlap. */ | |
b5c3c805 | 1070 | if ((!cfun || gimple_in_ssa_p (cfun)) |
9a14ba4f | 1071 | && operand_equal_p (ptr1, ptr2, 0) |
1072 | && (((TREE_CODE (base1) != TARGET_MEM_REF | |
88be3999 | 1073 | || (!TMR_INDEX (base1) && !TMR_INDEX2 (base1))) |
9a14ba4f | 1074 | && (TREE_CODE (base2) != TARGET_MEM_REF |
88be3999 | 1075 | || (!TMR_INDEX (base2) && !TMR_INDEX2 (base2)))) |
9a14ba4f | 1076 | || (TREE_CODE (base1) == TARGET_MEM_REF |
1077 | && TREE_CODE (base2) == TARGET_MEM_REF | |
1078 | && (TMR_STEP (base1) == TMR_STEP (base2) | |
1079 | || (TMR_STEP (base1) && TMR_STEP (base2) | |
1080 | && operand_equal_p (TMR_STEP (base1), | |
1081 | TMR_STEP (base2), 0))) | |
88be3999 | 1082 | && (TMR_INDEX (base1) == TMR_INDEX (base2) |
1083 | || (TMR_INDEX (base1) && TMR_INDEX (base2) | |
1084 | && operand_equal_p (TMR_INDEX (base1), | |
1085 | TMR_INDEX (base2), 0))) | |
1086 | && (TMR_INDEX2 (base1) == TMR_INDEX2 (base2) | |
1087 | || (TMR_INDEX2 (base1) && TMR_INDEX2 (base2) | |
1088 | && operand_equal_p (TMR_INDEX2 (base1), | |
1089 | TMR_INDEX2 (base2), 0)))))) | |
182cf5a9 | 1090 | { |
2622064f | 1091 | double_int moff; |
7749ee1c | 1092 | /* The offset embedded in MEM_REFs can be negative. Bias them |
1093 | so that the resulting offset adjustment is positive. */ | |
2622064f | 1094 | moff = mem_ref_offset (base1); |
9a8b9e26 | 1095 | moff = moff.lshift (BITS_PER_UNIT == 8 ? 3 : exact_log2 (BITS_PER_UNIT)); |
cf8f0e63 | 1096 | if (moff.is_negative ()) |
1097 | offset2 += (-moff).low; | |
2622064f | 1098 | else |
1099 | offset1 += moff.low; | |
1100 | moff = mem_ref_offset (base2); | |
9a8b9e26 | 1101 | moff = moff.lshift (BITS_PER_UNIT == 8 ? 3 : exact_log2 (BITS_PER_UNIT)); |
cf8f0e63 | 1102 | if (moff.is_negative ()) |
1103 | offset1 += (-moff).low; | |
2622064f | 1104 | else |
1105 | offset2 += moff.low; | |
182cf5a9 | 1106 | return ranges_overlap_p (offset1, max_size1, offset2, max_size2); |
1107 | } | |
dd277d48 | 1108 | if (!ptr_derefs_may_alias_p (ptr1, ptr2)) |
1109 | return false; | |
1110 | ||
1111 | /* Disambiguations that rely on strict aliasing rules follow. */ | |
182cf5a9 | 1112 | if (!flag_strict_aliasing || !tbaa_p) |
dd277d48 | 1113 | return true; |
1114 | ||
2622064f | 1115 | ptrtype1 = TREE_TYPE (TREE_OPERAND (base1, 1)); |
1116 | ptrtype2 = TREE_TYPE (TREE_OPERAND (base2, 1)); | |
182cf5a9 | 1117 | |
dd277d48 | 1118 | /* If the alias set for a pointer access is zero all bets are off. */ |
1119 | if (base1_alias_set == -1) | |
182cf5a9 | 1120 | base1_alias_set = get_deref_alias_set (ptrtype1); |
dd277d48 | 1121 | if (base1_alias_set == 0) |
1122 | return true; | |
1123 | if (base2_alias_set == -1) | |
182cf5a9 | 1124 | base2_alias_set = get_deref_alias_set (ptrtype2); |
dd277d48 | 1125 | if (base2_alias_set == 0) |
1126 | return true; | |
1127 | ||
1128 | /* If both references are through the same type, they do not alias | |
1129 | if the accesses do not overlap. This does extra disambiguation | |
1130 | for mixed/pointer accesses but requires strict aliasing. */ | |
9c455d1e | 1131 | if ((TREE_CODE (base1) != TARGET_MEM_REF |
1132 | || (!TMR_INDEX (base1) && !TMR_INDEX2 (base1))) | |
1133 | && (TREE_CODE (base2) != TARGET_MEM_REF | |
1134 | || (!TMR_INDEX (base2) && !TMR_INDEX2 (base2))) | |
1135 | && same_type_for_tbaa (TREE_TYPE (base1), TREE_TYPE (ptrtype1)) == 1 | |
1136 | && same_type_for_tbaa (TREE_TYPE (base2), TREE_TYPE (ptrtype2)) == 1 | |
182cf5a9 | 1137 | && same_type_for_tbaa (TREE_TYPE (ptrtype1), |
1138 | TREE_TYPE (ptrtype2)) == 1) | |
dd277d48 | 1139 | return ranges_overlap_p (offset1, max_size1, offset2, max_size2); |
1140 | ||
1141 | /* Do type-based disambiguation. */ | |
1142 | if (base1_alias_set != base2_alias_set | |
1143 | && !alias_sets_conflict_p (base1_alias_set, base2_alias_set)) | |
1144 | return false; | |
1145 | ||
1146 | /* Do access-path based disambiguation. */ | |
1147 | if (ref1 && ref2 | |
9c455d1e | 1148 | && (handled_component_p (ref1) || handled_component_p (ref2)) |
1149 | && same_type_for_tbaa (TREE_TYPE (base1), TREE_TYPE (ptrtype1)) == 1 | |
1150 | && same_type_for_tbaa (TREE_TYPE (base2), TREE_TYPE (ptrtype2)) == 1) | |
0d2f7431 | 1151 | return aliasing_component_refs_p (ref1, |
ac30e3b2 | 1152 | ref1_alias_set, base1_alias_set, |
a42ce2cc | 1153 | offset1, max_size1, |
0d2f7431 | 1154 | ref2, |
ac30e3b2 | 1155 | ref2_alias_set, base2_alias_set, |
1156 | offset2, max_size2, false); | |
dd277d48 | 1157 | |
1158 | return true; | |
1159 | } | |
1160 | ||
1161 | /* Return true, if the two memory references REF1 and REF2 may alias. */ | |
1162 | ||
3a443843 | 1163 | bool |
3918bd18 | 1164 | refs_may_alias_p_1 (ao_ref *ref1, ao_ref *ref2, bool tbaa_p) |
dd277d48 | 1165 | { |
1166 | tree base1, base2; | |
1167 | HOST_WIDE_INT offset1 = 0, offset2 = 0; | |
dd277d48 | 1168 | HOST_WIDE_INT max_size1 = -1, max_size2 = -1; |
1169 | bool var1_p, var2_p, ind1_p, ind2_p; | |
1170 | ||
c78d5cec | 1171 | gcc_checking_assert ((!ref1->ref |
8e7c2b9c | 1172 | || TREE_CODE (ref1->ref) == SSA_NAME |
c78d5cec | 1173 | || DECL_P (ref1->ref) |
2760c0e3 | 1174 | || TREE_CODE (ref1->ref) == STRING_CST |
c78d5cec | 1175 | || handled_component_p (ref1->ref) |
182cf5a9 | 1176 | || TREE_CODE (ref1->ref) == MEM_REF |
c78d5cec | 1177 | || TREE_CODE (ref1->ref) == TARGET_MEM_REF) |
1178 | && (!ref2->ref | |
8e7c2b9c | 1179 | || TREE_CODE (ref2->ref) == SSA_NAME |
c78d5cec | 1180 | || DECL_P (ref2->ref) |
2760c0e3 | 1181 | || TREE_CODE (ref2->ref) == STRING_CST |
c78d5cec | 1182 | || handled_component_p (ref2->ref) |
182cf5a9 | 1183 | || TREE_CODE (ref2->ref) == MEM_REF |
c78d5cec | 1184 | || TREE_CODE (ref2->ref) == TARGET_MEM_REF)); |
dd277d48 | 1185 | |
dd277d48 | 1186 | /* Decompose the references into their base objects and the access. */ |
3918bd18 | 1187 | base1 = ao_ref_base (ref1); |
1188 | offset1 = ref1->offset; | |
3918bd18 | 1189 | max_size1 = ref1->max_size; |
1190 | base2 = ao_ref_base (ref2); | |
1191 | offset2 = ref2->offset; | |
3918bd18 | 1192 | max_size2 = ref2->max_size; |
dd277d48 | 1193 | |
1194 | /* We can end up with registers or constants as bases for example from | |
1195 | *D.1663_44 = VIEW_CONVERT_EXPR<struct DB_LSN>(__tmp$B0F64_59); | |
1196 | which is seen as a struct copy. */ | |
1197 | if (TREE_CODE (base1) == SSA_NAME | |
119147d1 | 1198 | || TREE_CODE (base1) == CONST_DECL |
66b86a74 | 1199 | || TREE_CODE (base1) == CONSTRUCTOR |
1200 | || TREE_CODE (base1) == ADDR_EXPR | |
1201 | || CONSTANT_CLASS_P (base1) | |
1202 | || TREE_CODE (base2) == SSA_NAME | |
119147d1 | 1203 | || TREE_CODE (base2) == CONST_DECL |
66b86a74 | 1204 | || TREE_CODE (base2) == CONSTRUCTOR |
1205 | || TREE_CODE (base2) == ADDR_EXPR | |
1206 | || CONSTANT_CLASS_P (base2)) | |
dd277d48 | 1207 | return false; |
1208 | ||
04ec15fa | 1209 | /* We can end up referring to code via function and label decls. |
c78d5cec | 1210 | As we likely do not properly track code aliases conservatively |
1211 | bail out. */ | |
ceefbccc | 1212 | if (TREE_CODE (base1) == FUNCTION_DECL |
c78d5cec | 1213 | || TREE_CODE (base1) == LABEL_DECL |
66b86a74 | 1214 | || TREE_CODE (base2) == FUNCTION_DECL |
c78d5cec | 1215 | || TREE_CODE (base2) == LABEL_DECL) |
ceefbccc | 1216 | return true; |
1217 | ||
3787db52 | 1218 | /* Two volatile accesses always conflict. */ |
1219 | if (ref1->volatile_p | |
1220 | && ref2->volatile_p) | |
1221 | return true; | |
1222 | ||
090a8c65 | 1223 | /* Defer to simple offset based disambiguation if we have |
1224 | references based on two decls. Do this before defering to | |
1225 | TBAA to handle must-alias cases in conformance with the | |
1226 | GCC extension of allowing type-punning through unions. */ | |
2622064f | 1227 | var1_p = DECL_P (base1); |
1228 | var2_p = DECL_P (base2); | |
dd277d48 | 1229 | if (var1_p && var2_p) |
740a2cb6 | 1230 | return decl_refs_may_alias_p (ref1->ref, base1, offset1, max_size1, |
1231 | ref2->ref, base2, offset2, max_size2); | |
090a8c65 | 1232 | |
2622064f | 1233 | ind1_p = (TREE_CODE (base1) == MEM_REF |
1234 | || TREE_CODE (base1) == TARGET_MEM_REF); | |
1235 | ind2_p = (TREE_CODE (base2) == MEM_REF | |
1236 | || TREE_CODE (base2) == TARGET_MEM_REF); | |
182cf5a9 | 1237 | |
67817f0f | 1238 | /* Canonicalize the pointer-vs-decl case. */ |
1239 | if (ind1_p && var2_p) | |
1240 | { | |
1241 | HOST_WIDE_INT tmp1; | |
1242 | tree tmp2; | |
1243 | ao_ref *tmp3; | |
1244 | tmp1 = offset1; offset1 = offset2; offset2 = tmp1; | |
1245 | tmp1 = max_size1; max_size1 = max_size2; max_size2 = tmp1; | |
1246 | tmp2 = base1; base1 = base2; base2 = tmp2; | |
1247 | tmp3 = ref1; ref1 = ref2; ref2 = tmp3; | |
1248 | var1_p = true; | |
1249 | ind1_p = false; | |
1250 | var2_p = false; | |
1251 | ind2_p = true; | |
1252 | } | |
1253 | ||
090a8c65 | 1254 | /* First defer to TBAA if possible. */ |
2a3ebafa | 1255 | if (tbaa_p |
1256 | && flag_strict_aliasing | |
3918bd18 | 1257 | && !alias_sets_conflict_p (ao_ref_alias_set (ref1), |
1258 | ao_ref_alias_set (ref2))) | |
090a8c65 | 1259 | return false; |
1260 | ||
090a8c65 | 1261 | /* Dispatch to the pointer-vs-decl or pointer-vs-pointer disambiguators. */ |
090a8c65 | 1262 | if (var1_p && ind2_p) |
182cf5a9 | 1263 | return indirect_ref_may_alias_decl_p (ref2->ref, base2, |
ac30e3b2 | 1264 | offset2, max_size2, |
182cf5a9 | 1265 | ao_ref_alias_set (ref2), -1, |
3918bd18 | 1266 | ref1->ref, base1, |
ac30e3b2 | 1267 | offset1, max_size1, |
182cf5a9 | 1268 | ao_ref_alias_set (ref1), |
1269 | ao_ref_base_alias_set (ref1), | |
1270 | tbaa_p); | |
dd277d48 | 1271 | else if (ind1_p && ind2_p) |
182cf5a9 | 1272 | return indirect_refs_may_alias_p (ref1->ref, base1, |
ac30e3b2 | 1273 | offset1, max_size1, |
182cf5a9 | 1274 | ao_ref_alias_set (ref1), -1, |
1275 | ref2->ref, base2, | |
ac30e3b2 | 1276 | offset2, max_size2, |
182cf5a9 | 1277 | ao_ref_alias_set (ref2), -1, |
1278 | tbaa_p); | |
dd277d48 | 1279 | |
9c01641d | 1280 | /* We really do not want to end up here, but returning true is safe. */ |
1281 | #ifdef ENABLE_CHECKING | |
dd277d48 | 1282 | gcc_unreachable (); |
9c01641d | 1283 | #else |
1284 | return true; | |
1285 | #endif | |
dd277d48 | 1286 | } |
1287 | ||
1288 | bool | |
1289 | refs_may_alias_p (tree ref1, tree ref2) | |
1290 | { | |
3918bd18 | 1291 | ao_ref r1, r2; |
1292 | bool res; | |
1293 | ao_ref_init (&r1, ref1); | |
1294 | ao_ref_init (&r2, ref2); | |
1295 | res = refs_may_alias_p_1 (&r1, &r2, true); | |
dd277d48 | 1296 | if (res) |
1297 | ++alias_stats.refs_may_alias_p_may_alias; | |
1298 | else | |
1299 | ++alias_stats.refs_may_alias_p_no_alias; | |
1300 | return res; | |
1301 | } | |
1302 | ||
2a3ebafa | 1303 | /* Returns true if there is a anti-dependence for the STORE that |
1304 | executes after the LOAD. */ | |
1305 | ||
1306 | bool | |
1307 | refs_anti_dependent_p (tree load, tree store) | |
1308 | { | |
3918bd18 | 1309 | ao_ref r1, r2; |
1310 | ao_ref_init (&r1, load); | |
1311 | ao_ref_init (&r2, store); | |
1312 | return refs_may_alias_p_1 (&r1, &r2, false); | |
2a3ebafa | 1313 | } |
1314 | ||
1315 | /* Returns true if there is a output dependence for the stores | |
1316 | STORE1 and STORE2. */ | |
1317 | ||
1318 | bool | |
1319 | refs_output_dependent_p (tree store1, tree store2) | |
1320 | { | |
3918bd18 | 1321 | ao_ref r1, r2; |
1322 | ao_ref_init (&r1, store1); | |
1323 | ao_ref_init (&r2, store2); | |
1324 | return refs_may_alias_p_1 (&r1, &r2, false); | |
2a3ebafa | 1325 | } |
dd277d48 | 1326 | |
1327 | /* If the call CALL may use the memory reference REF return true, | |
1328 | otherwise return false. */ | |
1329 | ||
1330 | static bool | |
134899ac | 1331 | ref_maybe_used_by_call_p_1 (gimple call, ao_ref *ref) |
dd277d48 | 1332 | { |
047fdd47 | 1333 | tree base, callee; |
dd277d48 | 1334 | unsigned i; |
1335 | int flags = gimple_call_flags (call); | |
1336 | ||
1337 | /* Const functions without a static chain do not implicitly use memory. */ | |
1338 | if (!gimple_call_chain (call) | |
1339 | && (flags & (ECF_CONST|ECF_NOVOPS))) | |
1340 | goto process_args; | |
1341 | ||
134899ac | 1342 | base = ao_ref_base (ref); |
917f08fa | 1343 | if (!base) |
dd277d48 | 1344 | return true; |
1345 | ||
3787db52 | 1346 | /* A call that is not without side-effects might involve volatile |
1347 | accesses and thus conflicts with all other volatile accesses. */ | |
1348 | if (ref->volatile_p) | |
1349 | return true; | |
1350 | ||
09347e88 | 1351 | /* If the reference is based on a decl that is not aliased the call |
1352 | cannot possibly use it. */ | |
1353 | if (DECL_P (base) | |
1354 | && !may_be_aliased (base) | |
7f7f16d4 | 1355 | /* But local statics can be used through recursion. */ |
1356 | && !is_global_var (base)) | |
09347e88 | 1357 | goto process_args; |
1358 | ||
047fdd47 | 1359 | callee = gimple_call_fndecl (call); |
1360 | ||
1361 | /* Handle those builtin functions explicitly that do not act as | |
1362 | escape points. See tree-ssa-structalias.c:find_func_aliases | |
1363 | for the list of builtins we might need to handle here. */ | |
1364 | if (callee != NULL_TREE | |
1365 | && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL) | |
1366 | switch (DECL_FUNCTION_CODE (callee)) | |
1367 | { | |
77efe819 | 1368 | /* All the following functions read memory pointed to by |
1369 | their second argument. strcat/strncat additionally | |
1370 | reads memory pointed to by the first argument. */ | |
1371 | case BUILT_IN_STRCAT: | |
1372 | case BUILT_IN_STRNCAT: | |
1373 | { | |
1374 | ao_ref dref; | |
1375 | ao_ref_init_from_ptr_and_size (&dref, | |
1376 | gimple_call_arg (call, 0), | |
1377 | NULL_TREE); | |
1378 | if (refs_may_alias_p_1 (&dref, ref, false)) | |
1379 | return true; | |
1380 | } | |
1381 | /* FALLTHRU */ | |
047fdd47 | 1382 | case BUILT_IN_STRCPY: |
1383 | case BUILT_IN_STRNCPY: | |
047fdd47 | 1384 | case BUILT_IN_MEMCPY: |
1385 | case BUILT_IN_MEMMOVE: | |
1386 | case BUILT_IN_MEMPCPY: | |
1387 | case BUILT_IN_STPCPY: | |
1388 | case BUILT_IN_STPNCPY: | |
4c0315d0 | 1389 | case BUILT_IN_TM_MEMCPY: |
1390 | case BUILT_IN_TM_MEMMOVE: | |
047fdd47 | 1391 | { |
134899ac | 1392 | ao_ref dref; |
1393 | tree size = NULL_TREE; | |
1394 | if (gimple_call_num_args (call) == 3) | |
1395 | size = gimple_call_arg (call, 2); | |
1396 | ao_ref_init_from_ptr_and_size (&dref, | |
1397 | gimple_call_arg (call, 1), | |
1398 | size); | |
1399 | return refs_may_alias_p_1 (&dref, ref, false); | |
047fdd47 | 1400 | } |
77efe819 | 1401 | case BUILT_IN_STRCAT_CHK: |
1402 | case BUILT_IN_STRNCAT_CHK: | |
1403 | { | |
1404 | ao_ref dref; | |
1405 | ao_ref_init_from_ptr_and_size (&dref, | |
1406 | gimple_call_arg (call, 0), | |
1407 | NULL_TREE); | |
1408 | if (refs_may_alias_p_1 (&dref, ref, false)) | |
1409 | return true; | |
1410 | } | |
1411 | /* FALLTHRU */ | |
939514e9 | 1412 | case BUILT_IN_STRCPY_CHK: |
1413 | case BUILT_IN_STRNCPY_CHK: | |
1414 | case BUILT_IN_MEMCPY_CHK: | |
1415 | case BUILT_IN_MEMMOVE_CHK: | |
1416 | case BUILT_IN_MEMPCPY_CHK: | |
1417 | case BUILT_IN_STPCPY_CHK: | |
1063acde | 1418 | case BUILT_IN_STPNCPY_CHK: |
939514e9 | 1419 | { |
1420 | ao_ref dref; | |
1421 | tree size = NULL_TREE; | |
1422 | if (gimple_call_num_args (call) == 4) | |
1423 | size = gimple_call_arg (call, 2); | |
1424 | ao_ref_init_from_ptr_and_size (&dref, | |
1425 | gimple_call_arg (call, 1), | |
1426 | size); | |
1427 | return refs_may_alias_p_1 (&dref, ref, false); | |
1428 | } | |
119147d1 | 1429 | case BUILT_IN_BCOPY: |
1430 | { | |
1431 | ao_ref dref; | |
1432 | tree size = gimple_call_arg (call, 2); | |
1433 | ao_ref_init_from_ptr_and_size (&dref, | |
1434 | gimple_call_arg (call, 0), | |
1435 | size); | |
1436 | return refs_may_alias_p_1 (&dref, ref, false); | |
1437 | } | |
4c0315d0 | 1438 | |
1439 | /* The following functions read memory pointed to by their | |
1440 | first argument. */ | |
1441 | CASE_BUILT_IN_TM_LOAD (1): | |
1442 | CASE_BUILT_IN_TM_LOAD (2): | |
1443 | CASE_BUILT_IN_TM_LOAD (4): | |
1444 | CASE_BUILT_IN_TM_LOAD (8): | |
1445 | CASE_BUILT_IN_TM_LOAD (FLOAT): | |
1446 | CASE_BUILT_IN_TM_LOAD (DOUBLE): | |
1447 | CASE_BUILT_IN_TM_LOAD (LDOUBLE): | |
1448 | CASE_BUILT_IN_TM_LOAD (M64): | |
1449 | CASE_BUILT_IN_TM_LOAD (M128): | |
1450 | CASE_BUILT_IN_TM_LOAD (M256): | |
1451 | case BUILT_IN_TM_LOG: | |
1452 | case BUILT_IN_TM_LOG_1: | |
1453 | case BUILT_IN_TM_LOG_2: | |
1454 | case BUILT_IN_TM_LOG_4: | |
1455 | case BUILT_IN_TM_LOG_8: | |
1456 | case BUILT_IN_TM_LOG_FLOAT: | |
1457 | case BUILT_IN_TM_LOG_DOUBLE: | |
1458 | case BUILT_IN_TM_LOG_LDOUBLE: | |
1459 | case BUILT_IN_TM_LOG_M64: | |
1460 | case BUILT_IN_TM_LOG_M128: | |
1461 | case BUILT_IN_TM_LOG_M256: | |
1462 | return ptr_deref_may_alias_ref_p_1 (gimple_call_arg (call, 0), ref); | |
1463 | ||
77efe819 | 1464 | /* These read memory pointed to by the first argument. */ |
1465 | case BUILT_IN_STRDUP: | |
1466 | case BUILT_IN_STRNDUP: | |
1467 | { | |
1468 | ao_ref dref; | |
1469 | tree size = NULL_TREE; | |
1470 | if (gimple_call_num_args (call) == 2) | |
1471 | size = gimple_call_arg (call, 1); | |
1472 | ao_ref_init_from_ptr_and_size (&dref, | |
1473 | gimple_call_arg (call, 0), | |
1474 | size); | |
1475 | return refs_may_alias_p_1 (&dref, ref, false); | |
1476 | } | |
4953672f | 1477 | /* These read memory pointed to by the first argument. */ |
1478 | case BUILT_IN_INDEX: | |
1479 | case BUILT_IN_STRCHR: | |
1480 | case BUILT_IN_STRRCHR: | |
1481 | { | |
1482 | ao_ref dref; | |
1483 | ao_ref_init_from_ptr_and_size (&dref, | |
1484 | gimple_call_arg (call, 0), | |
1485 | NULL_TREE); | |
1486 | return refs_may_alias_p_1 (&dref, ref, false); | |
1487 | } | |
1488 | /* These read memory pointed to by the first argument with size | |
1489 | in the third argument. */ | |
1490 | case BUILT_IN_MEMCHR: | |
1491 | { | |
1492 | ao_ref dref; | |
1493 | ao_ref_init_from_ptr_and_size (&dref, | |
1494 | gimple_call_arg (call, 0), | |
1495 | gimple_call_arg (call, 2)); | |
1496 | return refs_may_alias_p_1 (&dref, ref, false); | |
1497 | } | |
1498 | /* These read memory pointed to by the first and second arguments. */ | |
1499 | case BUILT_IN_STRSTR: | |
1500 | case BUILT_IN_STRPBRK: | |
1501 | { | |
1502 | ao_ref dref; | |
1503 | ao_ref_init_from_ptr_and_size (&dref, | |
1504 | gimple_call_arg (call, 0), | |
1505 | NULL_TREE); | |
1506 | if (refs_may_alias_p_1 (&dref, ref, false)) | |
1507 | return true; | |
1508 | ao_ref_init_from_ptr_and_size (&dref, | |
1509 | gimple_call_arg (call, 1), | |
1510 | NULL_TREE); | |
1511 | return refs_may_alias_p_1 (&dref, ref, false); | |
1512 | } | |
1513 | ||
09d9c774 | 1514 | /* The following builtins do not read from memory. */ |
1515 | case BUILT_IN_FREE: | |
0d3ca08e | 1516 | case BUILT_IN_MALLOC: |
4ef43bbd | 1517 | case BUILT_IN_CALLOC: |
ca793672 | 1518 | case BUILT_IN_ALLOCA: |
581bf1c2 | 1519 | case BUILT_IN_ALLOCA_WITH_ALIGN: |
ca793672 | 1520 | case BUILT_IN_STACK_SAVE: |
1521 | case BUILT_IN_STACK_RESTORE: | |
09d9c774 | 1522 | case BUILT_IN_MEMSET: |
4c0315d0 | 1523 | case BUILT_IN_TM_MEMSET: |
939514e9 | 1524 | case BUILT_IN_MEMSET_CHK: |
09d9c774 | 1525 | case BUILT_IN_FREXP: |
1526 | case BUILT_IN_FREXPF: | |
1527 | case BUILT_IN_FREXPL: | |
1528 | case BUILT_IN_GAMMA_R: | |
1529 | case BUILT_IN_GAMMAF_R: | |
1530 | case BUILT_IN_GAMMAL_R: | |
1531 | case BUILT_IN_LGAMMA_R: | |
1532 | case BUILT_IN_LGAMMAF_R: | |
1533 | case BUILT_IN_LGAMMAL_R: | |
1534 | case BUILT_IN_MODF: | |
1535 | case BUILT_IN_MODFF: | |
1536 | case BUILT_IN_MODFL: | |
1537 | case BUILT_IN_REMQUO: | |
1538 | case BUILT_IN_REMQUOF: | |
1539 | case BUILT_IN_REMQUOL: | |
1540 | case BUILT_IN_SINCOS: | |
1541 | case BUILT_IN_SINCOSF: | |
1542 | case BUILT_IN_SINCOSL: | |
fca0886c | 1543 | case BUILT_IN_ASSUME_ALIGNED: |
9d17b4a8 | 1544 | case BUILT_IN_VA_END: |
09d9c774 | 1545 | return false; |
a44814b9 | 1546 | /* __sync_* builtins and some OpenMP builtins act as threading |
1547 | barriers. */ | |
1548 | #undef DEF_SYNC_BUILTIN | |
1549 | #define DEF_SYNC_BUILTIN(ENUM, NAME, TYPE, ATTRS) case ENUM: | |
1550 | #include "sync-builtins.def" | |
1551 | #undef DEF_SYNC_BUILTIN | |
1552 | case BUILT_IN_GOMP_ATOMIC_START: | |
1553 | case BUILT_IN_GOMP_ATOMIC_END: | |
1554 | case BUILT_IN_GOMP_BARRIER: | |
bc7bff74 | 1555 | case BUILT_IN_GOMP_BARRIER_CANCEL: |
a44814b9 | 1556 | case BUILT_IN_GOMP_TASKWAIT: |
bc7bff74 | 1557 | case BUILT_IN_GOMP_TASKGROUP_END: |
a44814b9 | 1558 | case BUILT_IN_GOMP_CRITICAL_START: |
1559 | case BUILT_IN_GOMP_CRITICAL_END: | |
1560 | case BUILT_IN_GOMP_CRITICAL_NAME_START: | |
1561 | case BUILT_IN_GOMP_CRITICAL_NAME_END: | |
1562 | case BUILT_IN_GOMP_LOOP_END: | |
bc7bff74 | 1563 | case BUILT_IN_GOMP_LOOP_END_CANCEL: |
a44814b9 | 1564 | case BUILT_IN_GOMP_ORDERED_START: |
1565 | case BUILT_IN_GOMP_ORDERED_END: | |
a44814b9 | 1566 | case BUILT_IN_GOMP_SECTIONS_END: |
bc7bff74 | 1567 | case BUILT_IN_GOMP_SECTIONS_END_CANCEL: |
a44814b9 | 1568 | case BUILT_IN_GOMP_SINGLE_COPY_START: |
1569 | case BUILT_IN_GOMP_SINGLE_COPY_END: | |
1570 | return true; | |
09d9c774 | 1571 | |
047fdd47 | 1572 | default: |
1573 | /* Fallthru to general call handling. */; | |
1574 | } | |
1575 | ||
dd277d48 | 1576 | /* Check if base is a global static variable that is not read |
1577 | by the function. */ | |
924de091 | 1578 | if (callee != NULL_TREE |
1579 | && TREE_CODE (base) == VAR_DECL | |
d97be713 | 1580 | && TREE_STATIC (base)) |
4ee9c684 | 1581 | { |
924de091 | 1582 | struct cgraph_node *node = cgraph_get_node (callee); |
dd277d48 | 1583 | bitmap not_read; |
1584 | ||
924de091 | 1585 | /* FIXME: Callee can be an OMP builtin that does not have a call graph |
1586 | node yet. We should enforce that there are nodes for all decls in the | |
1587 | IL and remove this check instead. */ | |
1588 | if (node | |
1589 | && (not_read = ipa_reference_get_not_read_global (node)) | |
dd277d48 | 1590 | && bitmap_bit_p (not_read, DECL_UID (base))) |
1591 | goto process_args; | |
4ee9c684 | 1592 | } |
1593 | ||
cb245216 | 1594 | /* Check if the base variable is call-used. */ |
1595 | if (DECL_P (base)) | |
4ee9c684 | 1596 | { |
cb245216 | 1597 | if (pt_solution_includes (gimple_call_use_set (call), base)) |
dd277d48 | 1598 | return true; |
1599 | } | |
2622064f | 1600 | else if ((TREE_CODE (base) == MEM_REF |
1601 | || TREE_CODE (base) == TARGET_MEM_REF) | |
cb245216 | 1602 | && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME) |
dd277d48 | 1603 | { |
cb245216 | 1604 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0)); |
1605 | if (!pi) | |
1606 | return true; | |
917f08fa | 1607 | |
cb245216 | 1608 | if (pt_solutions_intersect (gimple_call_use_set (call), &pi->pt)) |
dd277d48 | 1609 | return true; |
1610 | } | |
cb245216 | 1611 | else |
1612 | return true; | |
dd277d48 | 1613 | |
1614 | /* Inspect call arguments for passed-by-value aliases. */ | |
1615 | process_args: | |
1616 | for (i = 0; i < gimple_call_num_args (call); ++i) | |
1617 | { | |
1618 | tree op = gimple_call_arg (call, i); | |
8ce86007 | 1619 | int flags = gimple_call_arg_flags (call, i); |
1620 | ||
1621 | if (flags & EAF_UNUSED) | |
1622 | continue; | |
dd277d48 | 1623 | |
dd277d48 | 1624 | if (TREE_CODE (op) == WITH_SIZE_EXPR) |
1625 | op = TREE_OPERAND (op, 0); | |
4ee9c684 | 1626 | |
dd277d48 | 1627 | if (TREE_CODE (op) != SSA_NAME |
134899ac | 1628 | && !is_gimple_min_invariant (op)) |
1629 | { | |
1630 | ao_ref r; | |
1631 | ao_ref_init (&r, op); | |
1632 | if (refs_may_alias_p_1 (&r, ref, true)) | |
1633 | return true; | |
1634 | } | |
4ee9c684 | 1635 | } |
1636 | ||
dd277d48 | 1637 | return false; |
1638 | } | |
1639 | ||
1640 | static bool | |
1641 | ref_maybe_used_by_call_p (gimple call, tree ref) | |
1642 | { | |
134899ac | 1643 | ao_ref r; |
1644 | bool res; | |
1645 | ao_ref_init (&r, ref); | |
1646 | res = ref_maybe_used_by_call_p_1 (call, &r); | |
dd277d48 | 1647 | if (res) |
1648 | ++alias_stats.ref_maybe_used_by_call_p_may_alias; | |
1649 | else | |
1650 | ++alias_stats.ref_maybe_used_by_call_p_no_alias; | |
1651 | return res; | |
4ee9c684 | 1652 | } |
1653 | ||
1654 | ||
dd277d48 | 1655 | /* If the statement STMT may use the memory reference REF return |
1656 | true, otherwise return false. */ | |
4ee9c684 | 1657 | |
dd277d48 | 1658 | bool |
1659 | ref_maybe_used_by_stmt_p (gimple stmt, tree ref) | |
4ee9c684 | 1660 | { |
dd277d48 | 1661 | if (is_gimple_assign (stmt)) |
1662 | { | |
1663 | tree rhs; | |
1664 | ||
1665 | /* All memory assign statements are single. */ | |
1666 | if (!gimple_assign_single_p (stmt)) | |
1667 | return false; | |
1668 | ||
1669 | rhs = gimple_assign_rhs1 (stmt); | |
1670 | if (is_gimple_reg (rhs) | |
1671 | || is_gimple_min_invariant (rhs) | |
1672 | || gimple_assign_rhs_code (stmt) == CONSTRUCTOR) | |
1673 | return false; | |
1674 | ||
1675 | return refs_may_alias_p (rhs, ref); | |
1676 | } | |
1677 | else if (is_gimple_call (stmt)) | |
1678 | return ref_maybe_used_by_call_p (stmt, ref); | |
91234829 | 1679 | else if (gimple_code (stmt) == GIMPLE_RETURN) |
1680 | { | |
1681 | tree retval = gimple_return_retval (stmt); | |
1682 | tree base; | |
1683 | if (retval | |
1684 | && TREE_CODE (retval) != SSA_NAME | |
1685 | && !is_gimple_min_invariant (retval) | |
1686 | && refs_may_alias_p (retval, ref)) | |
1687 | return true; | |
1688 | /* If ref escapes the function then the return acts as a use. */ | |
1689 | base = get_base_address (ref); | |
1690 | if (!base) | |
1691 | ; | |
1692 | else if (DECL_P (base)) | |
1693 | return is_global_var (base); | |
1694 | else if (TREE_CODE (base) == MEM_REF | |
1695 | || TREE_CODE (base) == TARGET_MEM_REF) | |
1696 | return ptr_deref_may_alias_global_p (TREE_OPERAND (base, 0)); | |
1697 | return false; | |
1698 | } | |
dd277d48 | 1699 | |
1700 | return true; | |
4ee9c684 | 1701 | } |
1702 | ||
dd277d48 | 1703 | /* If the call in statement CALL may clobber the memory reference REF |
1704 | return true, otherwise return false. */ | |
4ee9c684 | 1705 | |
dd277d48 | 1706 | static bool |
3918bd18 | 1707 | call_may_clobber_ref_p_1 (gimple call, ao_ref *ref) |
4ee9c684 | 1708 | { |
7f7f16d4 | 1709 | tree base; |
047fdd47 | 1710 | tree callee; |
dd277d48 | 1711 | |
1712 | /* If the call is pure or const it cannot clobber anything. */ | |
1713 | if (gimple_call_flags (call) | |
1714 | & (ECF_PURE|ECF_CONST|ECF_LOOPING_CONST_OR_PURE|ECF_NOVOPS)) | |
1715 | return false; | |
1716 | ||
3918bd18 | 1717 | base = ao_ref_base (ref); |
dd277d48 | 1718 | if (!base) |
1719 | return true; | |
1720 | ||
1721 | if (TREE_CODE (base) == SSA_NAME | |
1722 | || CONSTANT_CLASS_P (base)) | |
1723 | return false; | |
1724 | ||
3787db52 | 1725 | /* A call that is not without side-effects might involve volatile |
1726 | accesses and thus conflicts with all other volatile accesses. */ | |
1727 | if (ref->volatile_p) | |
1728 | return true; | |
1729 | ||
09347e88 | 1730 | /* If the reference is based on a decl that is not aliased the call |
1731 | cannot possibly clobber it. */ | |
1732 | if (DECL_P (base) | |
1733 | && !may_be_aliased (base) | |
7f7f16d4 | 1734 | /* But local non-readonly statics can be modified through recursion |
1735 | or the call may implement a threading barrier which we must | |
1736 | treat as may-def. */ | |
09347e88 | 1737 | && (TREE_READONLY (base) |
7f7f16d4 | 1738 | || !is_global_var (base))) |
09347e88 | 1739 | return false; |
1740 | ||
047fdd47 | 1741 | callee = gimple_call_fndecl (call); |
1742 | ||
1743 | /* Handle those builtin functions explicitly that do not act as | |
1744 | escape points. See tree-ssa-structalias.c:find_func_aliases | |
1745 | for the list of builtins we might need to handle here. */ | |
1746 | if (callee != NULL_TREE | |
1747 | && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL) | |
1748 | switch (DECL_FUNCTION_CODE (callee)) | |
1749 | { | |
1750 | /* All the following functions clobber memory pointed to by | |
1751 | their first argument. */ | |
1752 | case BUILT_IN_STRCPY: | |
1753 | case BUILT_IN_STRNCPY: | |
047fdd47 | 1754 | case BUILT_IN_MEMCPY: |
1755 | case BUILT_IN_MEMMOVE: | |
1756 | case BUILT_IN_MEMPCPY: | |
1757 | case BUILT_IN_STPCPY: | |
1758 | case BUILT_IN_STPNCPY: | |
1759 | case BUILT_IN_STRCAT: | |
1760 | case BUILT_IN_STRNCAT: | |
134899ac | 1761 | case BUILT_IN_MEMSET: |
4c0315d0 | 1762 | case BUILT_IN_TM_MEMSET: |
1763 | CASE_BUILT_IN_TM_STORE (1): | |
1764 | CASE_BUILT_IN_TM_STORE (2): | |
1765 | CASE_BUILT_IN_TM_STORE (4): | |
1766 | CASE_BUILT_IN_TM_STORE (8): | |
1767 | CASE_BUILT_IN_TM_STORE (FLOAT): | |
1768 | CASE_BUILT_IN_TM_STORE (DOUBLE): | |
1769 | CASE_BUILT_IN_TM_STORE (LDOUBLE): | |
1770 | CASE_BUILT_IN_TM_STORE (M64): | |
1771 | CASE_BUILT_IN_TM_STORE (M128): | |
1772 | CASE_BUILT_IN_TM_STORE (M256): | |
1773 | case BUILT_IN_TM_MEMCPY: | |
1774 | case BUILT_IN_TM_MEMMOVE: | |
047fdd47 | 1775 | { |
134899ac | 1776 | ao_ref dref; |
1777 | tree size = NULL_TREE; | |
77efe819 | 1778 | /* Don't pass in size for strncat, as the maximum size |
1779 | is strlen (dest) + n + 1 instead of n, resp. | |
1780 | n + 1 at dest + strlen (dest), but strlen (dest) isn't | |
1781 | known. */ | |
1782 | if (gimple_call_num_args (call) == 3 | |
1783 | && DECL_FUNCTION_CODE (callee) != BUILT_IN_STRNCAT) | |
134899ac | 1784 | size = gimple_call_arg (call, 2); |
1785 | ao_ref_init_from_ptr_and_size (&dref, | |
1786 | gimple_call_arg (call, 0), | |
1787 | size); | |
1788 | return refs_may_alias_p_1 (&dref, ref, false); | |
047fdd47 | 1789 | } |
939514e9 | 1790 | case BUILT_IN_STRCPY_CHK: |
1791 | case BUILT_IN_STRNCPY_CHK: | |
1792 | case BUILT_IN_MEMCPY_CHK: | |
1793 | case BUILT_IN_MEMMOVE_CHK: | |
1794 | case BUILT_IN_MEMPCPY_CHK: | |
1795 | case BUILT_IN_STPCPY_CHK: | |
1063acde | 1796 | case BUILT_IN_STPNCPY_CHK: |
939514e9 | 1797 | case BUILT_IN_STRCAT_CHK: |
1798 | case BUILT_IN_STRNCAT_CHK: | |
1799 | case BUILT_IN_MEMSET_CHK: | |
1800 | { | |
1801 | ao_ref dref; | |
1802 | tree size = NULL_TREE; | |
77efe819 | 1803 | /* Don't pass in size for __strncat_chk, as the maximum size |
1804 | is strlen (dest) + n + 1 instead of n, resp. | |
1805 | n + 1 at dest + strlen (dest), but strlen (dest) isn't | |
1806 | known. */ | |
1807 | if (gimple_call_num_args (call) == 4 | |
1808 | && DECL_FUNCTION_CODE (callee) != BUILT_IN_STRNCAT_CHK) | |
939514e9 | 1809 | size = gimple_call_arg (call, 2); |
1810 | ao_ref_init_from_ptr_and_size (&dref, | |
1811 | gimple_call_arg (call, 0), | |
1812 | size); | |
1813 | return refs_may_alias_p_1 (&dref, ref, false); | |
1814 | } | |
119147d1 | 1815 | case BUILT_IN_BCOPY: |
1816 | { | |
1817 | ao_ref dref; | |
1818 | tree size = gimple_call_arg (call, 2); | |
1819 | ao_ref_init_from_ptr_and_size (&dref, | |
1820 | gimple_call_arg (call, 1), | |
1821 | size); | |
1822 | return refs_may_alias_p_1 (&dref, ref, false); | |
1823 | } | |
0d3ca08e | 1824 | /* Allocating memory does not have any side-effects apart from |
1825 | being the definition point for the pointer. */ | |
1826 | case BUILT_IN_MALLOC: | |
4ef43bbd | 1827 | case BUILT_IN_CALLOC: |
77efe819 | 1828 | case BUILT_IN_STRDUP: |
1829 | case BUILT_IN_STRNDUP: | |
be97d4b6 | 1830 | /* Unix98 specifies that errno is set on allocation failure. */ |
a29c5f9c | 1831 | if (flag_errno_math |
be97d4b6 | 1832 | && targetm.ref_may_alias_errno (ref)) |
1833 | return true; | |
0d3ca08e | 1834 | return false; |
ca793672 | 1835 | case BUILT_IN_STACK_SAVE: |
1836 | case BUILT_IN_ALLOCA: | |
581bf1c2 | 1837 | case BUILT_IN_ALLOCA_WITH_ALIGN: |
fca0886c | 1838 | case BUILT_IN_ASSUME_ALIGNED: |
ca793672 | 1839 | return false; |
047fdd47 | 1840 | /* Freeing memory kills the pointed-to memory. More importantly |
1841 | the call has to serve as a barrier for moving loads and stores | |
134899ac | 1842 | across it. */ |
047fdd47 | 1843 | case BUILT_IN_FREE: |
9d17b4a8 | 1844 | case BUILT_IN_VA_END: |
047fdd47 | 1845 | { |
1846 | tree ptr = gimple_call_arg (call, 0); | |
1847 | return ptr_deref_may_alias_ref_p_1 (ptr, ref); | |
1848 | } | |
047fdd47 | 1849 | case BUILT_IN_GAMMA_R: |
1850 | case BUILT_IN_GAMMAF_R: | |
1851 | case BUILT_IN_GAMMAL_R: | |
1852 | case BUILT_IN_LGAMMA_R: | |
1853 | case BUILT_IN_LGAMMAF_R: | |
1854 | case BUILT_IN_LGAMMAL_R: | |
09d9c774 | 1855 | { |
1856 | tree out = gimple_call_arg (call, 1); | |
1857 | if (ptr_deref_may_alias_ref_p_1 (out, ref)) | |
1858 | return true; | |
1859 | if (flag_errno_math) | |
1860 | break; | |
1861 | return false; | |
1862 | } | |
1863 | case BUILT_IN_FREXP: | |
1864 | case BUILT_IN_FREXPF: | |
1865 | case BUILT_IN_FREXPL: | |
047fdd47 | 1866 | case BUILT_IN_MODF: |
1867 | case BUILT_IN_MODFF: | |
1868 | case BUILT_IN_MODFL: | |
1869 | { | |
1870 | tree out = gimple_call_arg (call, 1); | |
1871 | return ptr_deref_may_alias_ref_p_1 (out, ref); | |
1872 | } | |
1873 | case BUILT_IN_REMQUO: | |
1874 | case BUILT_IN_REMQUOF: | |
1875 | case BUILT_IN_REMQUOL: | |
1876 | { | |
1877 | tree out = gimple_call_arg (call, 2); | |
09d9c774 | 1878 | if (ptr_deref_may_alias_ref_p_1 (out, ref)) |
1879 | return true; | |
1880 | if (flag_errno_math) | |
1881 | break; | |
1882 | return false; | |
047fdd47 | 1883 | } |
1884 | case BUILT_IN_SINCOS: | |
1885 | case BUILT_IN_SINCOSF: | |
1886 | case BUILT_IN_SINCOSL: | |
1887 | { | |
1888 | tree sin = gimple_call_arg (call, 1); | |
1889 | tree cos = gimple_call_arg (call, 2); | |
1890 | return (ptr_deref_may_alias_ref_p_1 (sin, ref) | |
1891 | || ptr_deref_may_alias_ref_p_1 (cos, ref)); | |
1892 | } | |
a44814b9 | 1893 | /* __sync_* builtins and some OpenMP builtins act as threading |
1894 | barriers. */ | |
1895 | #undef DEF_SYNC_BUILTIN | |
1896 | #define DEF_SYNC_BUILTIN(ENUM, NAME, TYPE, ATTRS) case ENUM: | |
1897 | #include "sync-builtins.def" | |
1898 | #undef DEF_SYNC_BUILTIN | |
1899 | case BUILT_IN_GOMP_ATOMIC_START: | |
1900 | case BUILT_IN_GOMP_ATOMIC_END: | |
1901 | case BUILT_IN_GOMP_BARRIER: | |
bc7bff74 | 1902 | case BUILT_IN_GOMP_BARRIER_CANCEL: |
a44814b9 | 1903 | case BUILT_IN_GOMP_TASKWAIT: |
bc7bff74 | 1904 | case BUILT_IN_GOMP_TASKGROUP_END: |
a44814b9 | 1905 | case BUILT_IN_GOMP_CRITICAL_START: |
1906 | case BUILT_IN_GOMP_CRITICAL_END: | |
1907 | case BUILT_IN_GOMP_CRITICAL_NAME_START: | |
1908 | case BUILT_IN_GOMP_CRITICAL_NAME_END: | |
1909 | case BUILT_IN_GOMP_LOOP_END: | |
bc7bff74 | 1910 | case BUILT_IN_GOMP_LOOP_END_CANCEL: |
a44814b9 | 1911 | case BUILT_IN_GOMP_ORDERED_START: |
1912 | case BUILT_IN_GOMP_ORDERED_END: | |
a44814b9 | 1913 | case BUILT_IN_GOMP_SECTIONS_END: |
bc7bff74 | 1914 | case BUILT_IN_GOMP_SECTIONS_END_CANCEL: |
a44814b9 | 1915 | case BUILT_IN_GOMP_SINGLE_COPY_START: |
1916 | case BUILT_IN_GOMP_SINGLE_COPY_END: | |
1917 | return true; | |
047fdd47 | 1918 | default: |
1919 | /* Fallthru to general call handling. */; | |
1920 | } | |
1921 | ||
dd277d48 | 1922 | /* Check if base is a global static variable that is not written |
1923 | by the function. */ | |
047fdd47 | 1924 | if (callee != NULL_TREE |
1925 | && TREE_CODE (base) == VAR_DECL | |
d97be713 | 1926 | && TREE_STATIC (base)) |
4ee9c684 | 1927 | { |
924de091 | 1928 | struct cgraph_node *node = cgraph_get_node (callee); |
dd277d48 | 1929 | bitmap not_written; |
0eaf9bd7 | 1930 | |
924de091 | 1931 | if (node |
1932 | && (not_written = ipa_reference_get_not_written_global (node)) | |
dd277d48 | 1933 | && bitmap_bit_p (not_written, DECL_UID (base))) |
1934 | return false; | |
4ee9c684 | 1935 | } |
4ee9c684 | 1936 | |
cb245216 | 1937 | /* Check if the base variable is call-clobbered. */ |
dd277d48 | 1938 | if (DECL_P (base)) |
cb245216 | 1939 | return pt_solution_includes (gimple_call_clobber_set (call), base); |
2622064f | 1940 | else if ((TREE_CODE (base) == MEM_REF |
1941 | || TREE_CODE (base) == TARGET_MEM_REF) | |
917f08fa | 1942 | && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME) |
1943 | { | |
1944 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0)); | |
1945 | if (!pi) | |
1946 | return true; | |
1947 | ||
cb245216 | 1948 | return pt_solutions_intersect (gimple_call_clobber_set (call), &pi->pt); |
917f08fa | 1949 | } |
4ee9c684 | 1950 | |
dd277d48 | 1951 | return true; |
1952 | } | |
4ee9c684 | 1953 | |
4debfcfc | 1954 | /* If the call in statement CALL may clobber the memory reference REF |
1955 | return true, otherwise return false. */ | |
1956 | ||
1957 | bool | |
dd277d48 | 1958 | call_may_clobber_ref_p (gimple call, tree ref) |
4ee9c684 | 1959 | { |
3918bd18 | 1960 | bool res; |
1961 | ao_ref r; | |
1962 | ao_ref_init (&r, ref); | |
1963 | res = call_may_clobber_ref_p_1 (call, &r); | |
dd277d48 | 1964 | if (res) |
1965 | ++alias_stats.call_may_clobber_ref_p_may_alias; | |
1966 | else | |
1967 | ++alias_stats.call_may_clobber_ref_p_no_alias; | |
1968 | return res; | |
4ee9c684 | 1969 | } |
94e6573f | 1970 | |
dd277d48 | 1971 | |
1972 | /* If the statement STMT may clobber the memory reference REF return true, | |
1973 | otherwise return false. */ | |
94e6573f | 1974 | |
1975 | bool | |
3918bd18 | 1976 | stmt_may_clobber_ref_p_1 (gimple stmt, ao_ref *ref) |
94e6573f | 1977 | { |
dd277d48 | 1978 | if (is_gimple_call (stmt)) |
1979 | { | |
1980 | tree lhs = gimple_call_lhs (stmt); | |
1981 | if (lhs | |
66b86a74 | 1982 | && TREE_CODE (lhs) != SSA_NAME) |
3918bd18 | 1983 | { |
1984 | ao_ref r; | |
1985 | ao_ref_init (&r, lhs); | |
1986 | if (refs_may_alias_p_1 (ref, &r, true)) | |
1987 | return true; | |
1988 | } | |
94e6573f | 1989 | |
3918bd18 | 1990 | return call_may_clobber_ref_p_1 (stmt, ref); |
dd277d48 | 1991 | } |
8e7c2b9c | 1992 | else if (gimple_assign_single_p (stmt)) |
3918bd18 | 1993 | { |
8e7c2b9c | 1994 | tree lhs = gimple_assign_lhs (stmt); |
66b86a74 | 1995 | if (TREE_CODE (lhs) != SSA_NAME) |
8e7c2b9c | 1996 | { |
1997 | ao_ref r; | |
66b86a74 | 1998 | ao_ref_init (&r, lhs); |
8e7c2b9c | 1999 | return refs_may_alias_p_1 (ref, &r, true); |
2000 | } | |
3918bd18 | 2001 | } |
dd277d48 | 2002 | else if (gimple_code (stmt) == GIMPLE_ASM) |
94e6573f | 2003 | return true; |
2004 | ||
6329636b | 2005 | return false; |
94e6573f | 2006 | } |
2be14d8b | 2007 | |
3918bd18 | 2008 | bool |
2009 | stmt_may_clobber_ref_p (gimple stmt, tree ref) | |
2010 | { | |
2011 | ao_ref r; | |
2012 | ao_ref_init (&r, ref); | |
2013 | return stmt_may_clobber_ref_p_1 (stmt, &r); | |
2014 | } | |
2015 | ||
ab450cc6 | 2016 | /* If STMT kills the memory reference REF return true, otherwise |
2017 | return false. */ | |
2018 | ||
2019 | static bool | |
2020 | stmt_kills_ref_p_1 (gimple stmt, ao_ref *ref) | |
2021 | { | |
07ff6a65 | 2022 | /* For a must-alias check we need to be able to constrain |
e6c705fb | 2023 | the access properly. |
2024 | FIXME: except for BUILTIN_FREE. */ | |
2025 | if (!ao_ref_base (ref) | |
2026 | || ref->max_size == -1) | |
07ff6a65 | 2027 | return false; |
2028 | ||
ab450cc6 | 2029 | if (gimple_has_lhs (stmt) |
e54d36c4 | 2030 | && TREE_CODE (gimple_get_lhs (stmt)) != SSA_NAME |
2031 | /* The assignment is not necessarily carried out if it can throw | |
2032 | and we can catch it in the current function where we could inspect | |
2033 | the previous value. | |
2034 | ??? We only need to care about the RHS throwing. For aggregate | |
2035 | assignments or similar calls and non-call exceptions the LHS | |
2036 | might throw as well. */ | |
2037 | && !stmt_can_throw_internal (stmt)) | |
ab450cc6 | 2038 | { |
2039 | tree base, lhs = gimple_get_lhs (stmt); | |
137eddca | 2040 | HOST_WIDE_INT size, offset, max_size, ref_offset = ref->offset; |
ab450cc6 | 2041 | base = get_ref_base_and_extent (lhs, &offset, &size, &max_size); |
2042 | /* We can get MEM[symbol: sZ, index: D.8862_1] here, | |
2043 | so base == ref->base does not always hold. */ | |
137eddca | 2044 | if (base != ref->base) |
ab450cc6 | 2045 | { |
137eddca | 2046 | /* If both base and ref->base are MEM_REFs, only compare the |
2047 | first operand, and if the second operand isn't equal constant, | |
2048 | try to add the offsets into offset and ref_offset. */ | |
2049 | if (TREE_CODE (base) == MEM_REF && TREE_CODE (ref->base) == MEM_REF | |
2050 | && TREE_OPERAND (base, 0) == TREE_OPERAND (ref->base, 0)) | |
ab450cc6 | 2051 | { |
83d18d6d | 2052 | if (!tree_int_cst_equal (TREE_OPERAND (base, 1), |
2053 | TREE_OPERAND (ref->base, 1))) | |
137eddca | 2054 | { |
2055 | double_int off1 = mem_ref_offset (base); | |
9a8b9e26 | 2056 | off1 = off1.lshift (BITS_PER_UNIT == 8 |
2057 | ? 3 : exact_log2 (BITS_PER_UNIT)); | |
137eddca | 2058 | off1 = off1 + double_int::from_shwi (offset); |
2059 | double_int off2 = mem_ref_offset (ref->base); | |
9a8b9e26 | 2060 | off2 = off2.lshift (BITS_PER_UNIT == 8 |
2061 | ? 3 : exact_log2 (BITS_PER_UNIT)); | |
137eddca | 2062 | off2 = off2 + double_int::from_shwi (ref_offset); |
2063 | if (off1.fits_shwi () && off2.fits_shwi ()) | |
2064 | { | |
2065 | offset = off1.to_shwi (); | |
2066 | ref_offset = off2.to_shwi (); | |
2067 | } | |
2068 | else | |
2069 | size = -1; | |
2070 | } | |
ab450cc6 | 2071 | } |
137eddca | 2072 | else |
2073 | size = -1; | |
2074 | } | |
2075 | /* For a must-alias check we need to be able to constrain | |
2076 | the access properly. */ | |
2077 | if (size != -1 && size == max_size) | |
2078 | { | |
2079 | if (offset <= ref_offset | |
2080 | && offset + size >= ref_offset + ref->max_size) | |
2081 | return true; | |
ab450cc6 | 2082 | } |
2083 | } | |
07ff6a65 | 2084 | |
2085 | if (is_gimple_call (stmt)) | |
2086 | { | |
2087 | tree callee = gimple_call_fndecl (stmt); | |
2088 | if (callee != NULL_TREE | |
2089 | && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL) | |
2090 | switch (DECL_FUNCTION_CODE (callee)) | |
2091 | { | |
3d0ea943 | 2092 | case BUILT_IN_FREE: |
2093 | { | |
2094 | tree ptr = gimple_call_arg (stmt, 0); | |
2095 | tree base = ao_ref_base (ref); | |
2096 | if (base && TREE_CODE (base) == MEM_REF | |
2097 | && TREE_OPERAND (base, 0) == ptr) | |
2098 | return true; | |
2099 | break; | |
2100 | } | |
2101 | ||
07ff6a65 | 2102 | case BUILT_IN_MEMCPY: |
2103 | case BUILT_IN_MEMPCPY: | |
2104 | case BUILT_IN_MEMMOVE: | |
2105 | case BUILT_IN_MEMSET: | |
939514e9 | 2106 | case BUILT_IN_MEMCPY_CHK: |
2107 | case BUILT_IN_MEMPCPY_CHK: | |
2108 | case BUILT_IN_MEMMOVE_CHK: | |
2109 | case BUILT_IN_MEMSET_CHK: | |
07ff6a65 | 2110 | { |
2111 | tree dest = gimple_call_arg (stmt, 0); | |
2112 | tree len = gimple_call_arg (stmt, 2); | |
35ec552a | 2113 | if (!tree_fits_shwi_p (len)) |
07ff6a65 | 2114 | return false; |
e6c705fb | 2115 | tree rbase = ref->base; |
2116 | double_int roffset = double_int::from_shwi (ref->offset); | |
2117 | ao_ref dref; | |
2118 | ao_ref_init_from_ptr_and_size (&dref, dest, len); | |
2119 | tree base = ao_ref_base (&dref); | |
2120 | double_int offset = double_int::from_shwi (dref.offset); | |
2121 | double_int bpu = double_int::from_uhwi (BITS_PER_UNIT); | |
2122 | if (!base || dref.size == -1) | |
2123 | return false; | |
2124 | if (TREE_CODE (base) == MEM_REF) | |
2125 | { | |
2126 | if (TREE_CODE (rbase) != MEM_REF) | |
2127 | return false; | |
2128 | // Compare pointers. | |
2129 | offset += bpu * mem_ref_offset (base); | |
2130 | roffset += bpu * mem_ref_offset (rbase); | |
2131 | base = TREE_OPERAND (base, 0); | |
2132 | rbase = TREE_OPERAND (rbase, 0); | |
2133 | } | |
2134 | if (base == rbase) | |
07ff6a65 | 2135 | { |
e6c705fb | 2136 | double_int size = bpu * tree_to_double_int (len); |
2137 | double_int rsize = double_int::from_uhwi (ref->max_size); | |
2138 | if (offset.sle (roffset) | |
2139 | && (roffset + rsize).sle (offset + size)) | |
07ff6a65 | 2140 | return true; |
2141 | } | |
9d17b4a8 | 2142 | break; |
2143 | } | |
2144 | ||
2145 | case BUILT_IN_VA_END: | |
2146 | { | |
2147 | tree ptr = gimple_call_arg (stmt, 0); | |
2148 | if (TREE_CODE (ptr) == ADDR_EXPR) | |
2149 | { | |
2150 | tree base = ao_ref_base (ref); | |
2151 | if (TREE_OPERAND (ptr, 0) == base) | |
2152 | return true; | |
2153 | } | |
2154 | break; | |
07ff6a65 | 2155 | } |
9d17b4a8 | 2156 | |
07ff6a65 | 2157 | default:; |
2158 | } | |
07ff6a65 | 2159 | } |
ab450cc6 | 2160 | return false; |
2161 | } | |
2162 | ||
2163 | bool | |
2164 | stmt_kills_ref_p (gimple stmt, tree ref) | |
2165 | { | |
2166 | ao_ref r; | |
2167 | ao_ref_init (&r, ref); | |
2168 | return stmt_kills_ref_p_1 (stmt, &r); | |
2169 | } | |
2170 | ||
3918bd18 | 2171 | |
dd277d48 | 2172 | /* Walk the virtual use-def chain of VUSE until hitting the virtual operand |
2173 | TARGET or a statement clobbering the memory reference REF in which | |
2174 | case false is returned. The walk starts with VUSE, one argument of PHI. */ | |
2175 | ||
2176 | static bool | |
3918bd18 | 2177 | maybe_skip_until (gimple phi, tree target, ao_ref *ref, |
4fd7a6de | 2178 | tree vuse, unsigned int *cnt, bitmap *visited, |
2179 | bool abort_on_visited) | |
ac926412 | 2180 | { |
0afe880d | 2181 | basic_block bb = gimple_bb (phi); |
2182 | ||
dd277d48 | 2183 | if (!*visited) |
2184 | *visited = BITMAP_ALLOC (NULL); | |
ac926412 | 2185 | |
dd277d48 | 2186 | bitmap_set_bit (*visited, SSA_NAME_VERSION (PHI_RESULT (phi))); |
2187 | ||
2188 | /* Walk until we hit the target. */ | |
2189 | while (vuse != target) | |
ac926412 | 2190 | { |
dd277d48 | 2191 | gimple def_stmt = SSA_NAME_DEF_STMT (vuse); |
2192 | /* Recurse for PHI nodes. */ | |
2193 | if (gimple_code (def_stmt) == GIMPLE_PHI) | |
2194 | { | |
2195 | /* An already visited PHI node ends the walk successfully. */ | |
2196 | if (bitmap_bit_p (*visited, SSA_NAME_VERSION (PHI_RESULT (def_stmt)))) | |
4fd7a6de | 2197 | return !abort_on_visited; |
2198 | vuse = get_continuation_for_phi (def_stmt, ref, cnt, | |
2199 | visited, abort_on_visited); | |
dd277d48 | 2200 | if (!vuse) |
2201 | return false; | |
2202 | continue; | |
2203 | } | |
297a2110 | 2204 | else if (gimple_nop_p (def_stmt)) |
dd277d48 | 2205 | return false; |
297a2110 | 2206 | else |
2207 | { | |
2208 | /* A clobbering statement or the end of the IL ends it failing. */ | |
2209 | ++*cnt; | |
2210 | if (stmt_may_clobber_ref_p_1 (def_stmt, ref)) | |
2211 | return false; | |
2212 | } | |
0afe880d | 2213 | /* If we reach a new basic-block see if we already skipped it |
2214 | in a previous walk that ended successfully. */ | |
2215 | if (gimple_bb (def_stmt) != bb) | |
2216 | { | |
2217 | if (!bitmap_set_bit (*visited, SSA_NAME_VERSION (vuse))) | |
4fd7a6de | 2218 | return !abort_on_visited; |
0afe880d | 2219 | bb = gimple_bb (def_stmt); |
2220 | } | |
dd277d48 | 2221 | vuse = gimple_vuse (def_stmt); |
ac926412 | 2222 | } |
dd277d48 | 2223 | return true; |
2224 | } | |
ac926412 | 2225 | |
d7f69727 | 2226 | /* For two PHI arguments ARG0 and ARG1 try to skip non-aliasing code |
2227 | until we hit the phi argument definition that dominates the other one. | |
2228 | Return that, or NULL_TREE if there is no such definition. */ | |
2229 | ||
2230 | static tree | |
2231 | get_continuation_for_phi_1 (gimple phi, tree arg0, tree arg1, | |
4fd7a6de | 2232 | ao_ref *ref, unsigned int *cnt, |
2233 | bitmap *visited, bool abort_on_visited) | |
d7f69727 | 2234 | { |
2235 | gimple def0 = SSA_NAME_DEF_STMT (arg0); | |
2236 | gimple def1 = SSA_NAME_DEF_STMT (arg1); | |
2237 | tree common_vuse; | |
2238 | ||
2239 | if (arg0 == arg1) | |
2240 | return arg0; | |
2241 | else if (gimple_nop_p (def0) | |
2242 | || (!gimple_nop_p (def1) | |
2243 | && dominated_by_p (CDI_DOMINATORS, | |
2244 | gimple_bb (def1), gimple_bb (def0)))) | |
2245 | { | |
4fd7a6de | 2246 | if (maybe_skip_until (phi, arg0, ref, arg1, cnt, |
2247 | visited, abort_on_visited)) | |
d7f69727 | 2248 | return arg0; |
2249 | } | |
2250 | else if (gimple_nop_p (def1) | |
2251 | || dominated_by_p (CDI_DOMINATORS, | |
2252 | gimple_bb (def0), gimple_bb (def1))) | |
2253 | { | |
4fd7a6de | 2254 | if (maybe_skip_until (phi, arg1, ref, arg0, cnt, |
2255 | visited, abort_on_visited)) | |
d7f69727 | 2256 | return arg1; |
2257 | } | |
2258 | /* Special case of a diamond: | |
2259 | MEM_1 = ... | |
2260 | goto (cond) ? L1 : L2 | |
2261 | L1: store1 = ... #MEM_2 = vuse(MEM_1) | |
2262 | goto L3 | |
2263 | L2: store2 = ... #MEM_3 = vuse(MEM_1) | |
2264 | L3: MEM_4 = PHI<MEM_2, MEM_3> | |
2265 | We were called with the PHI at L3, MEM_2 and MEM_3 don't | |
2266 | dominate each other, but still we can easily skip this PHI node | |
2267 | if we recognize that the vuse MEM operand is the same for both, | |
2268 | and that we can skip both statements (they don't clobber us). | |
2269 | This is still linear. Don't use maybe_skip_until, that might | |
2270 | potentially be slow. */ | |
2271 | else if ((common_vuse = gimple_vuse (def0)) | |
2272 | && common_vuse == gimple_vuse (def1)) | |
2273 | { | |
297a2110 | 2274 | *cnt += 2; |
d7f69727 | 2275 | if (!stmt_may_clobber_ref_p_1 (def0, ref) |
2276 | && !stmt_may_clobber_ref_p_1 (def1, ref)) | |
2277 | return common_vuse; | |
2278 | } | |
2279 | ||
2280 | return NULL_TREE; | |
2281 | } | |
2282 | ||
2283 | ||
dd277d48 | 2284 | /* Starting from a PHI node for the virtual operand of the memory reference |
2285 | REF find a continuation virtual operand that allows to continue walking | |
2286 | statements dominating PHI skipping only statements that cannot possibly | |
297a2110 | 2287 | clobber REF. Increments *CNT for each alias disambiguation done. |
2288 | Returns NULL_TREE if no suitable virtual operand can be found. */ | |
dd277d48 | 2289 | |
7814d418 | 2290 | tree |
297a2110 | 2291 | get_continuation_for_phi (gimple phi, ao_ref *ref, |
4fd7a6de | 2292 | unsigned int *cnt, bitmap *visited, |
2293 | bool abort_on_visited) | |
dd277d48 | 2294 | { |
2295 | unsigned nargs = gimple_phi_num_args (phi); | |
2296 | ||
2297 | /* Through a single-argument PHI we can simply look through. */ | |
2298 | if (nargs == 1) | |
2299 | return PHI_ARG_DEF (phi, 0); | |
2300 | ||
d7f69727 | 2301 | /* For two or more arguments try to pairwise skip non-aliasing code |
2302 | until we hit the phi argument definition that dominates the other one. */ | |
2303 | else if (nargs >= 2) | |
ac926412 | 2304 | { |
0afe880d | 2305 | tree arg0, arg1; |
2306 | unsigned i; | |
2307 | ||
2308 | /* Find a candidate for the virtual operand which definition | |
2309 | dominates those of all others. */ | |
2310 | arg0 = PHI_ARG_DEF (phi, 0); | |
2311 | if (!SSA_NAME_IS_DEFAULT_DEF (arg0)) | |
2312 | for (i = 1; i < nargs; ++i) | |
2313 | { | |
2314 | arg1 = PHI_ARG_DEF (phi, i); | |
2315 | if (SSA_NAME_IS_DEFAULT_DEF (arg1)) | |
2316 | { | |
2317 | arg0 = arg1; | |
2318 | break; | |
2319 | } | |
2320 | if (dominated_by_p (CDI_DOMINATORS, | |
2321 | gimple_bb (SSA_NAME_DEF_STMT (arg0)), | |
2322 | gimple_bb (SSA_NAME_DEF_STMT (arg1)))) | |
2323 | arg0 = arg1; | |
2324 | } | |
2325 | ||
2326 | /* Then pairwise reduce against the found candidate. */ | |
2327 | for (i = 0; i < nargs; ++i) | |
7814d418 | 2328 | { |
d7f69727 | 2329 | arg1 = PHI_ARG_DEF (phi, i); |
297a2110 | 2330 | arg0 = get_continuation_for_phi_1 (phi, arg0, arg1, ref, |
4fd7a6de | 2331 | cnt, visited, abort_on_visited); |
d7f69727 | 2332 | if (!arg0) |
2333 | return NULL_TREE; | |
7814d418 | 2334 | } |
d7f69727 | 2335 | |
2336 | return arg0; | |
ac926412 | 2337 | } |
dd277d48 | 2338 | |
2339 | return NULL_TREE; | |
ac926412 | 2340 | } |
516849c7 | 2341 | |
dd277d48 | 2342 | /* Based on the memory reference REF and its virtual use VUSE call |
2343 | WALKER for each virtual use that is equivalent to VUSE, including VUSE | |
2344 | itself. That is, for each virtual use for which its defining statement | |
2345 | does not clobber REF. | |
e683de6d | 2346 | |
dd277d48 | 2347 | WALKER is called with REF, the current virtual use and DATA. If |
2348 | WALKER returns non-NULL the walk stops and its result is returned. | |
2349 | At the end of a non-successful walk NULL is returned. | |
3857274c | 2350 | |
d8021dea | 2351 | TRANSLATE if non-NULL is called with a pointer to REF, the virtual |
2352 | use which definition is a statement that may clobber REF and DATA. | |
2353 | If TRANSLATE returns (void *)-1 the walk stops and NULL is returned. | |
2354 | If TRANSLATE returns non-NULL the walk stops and its result is returned. | |
2355 | If TRANSLATE returns NULL the walk continues and TRANSLATE is supposed | |
2356 | to adjust REF and *DATA to make that valid. | |
2357 | ||
dd277d48 | 2358 | TODO: Cache the vector of equivalent vuses per ref, vuse pair. */ |
2359 | ||
2360 | void * | |
3918bd18 | 2361 | walk_non_aliased_vuses (ao_ref *ref, tree vuse, |
297a2110 | 2362 | void *(*walker)(ao_ref *, tree, unsigned int, void *), |
3918bd18 | 2363 | void *(*translate)(ao_ref *, tree, void *), void *data) |
3857274c | 2364 | { |
dd277d48 | 2365 | bitmap visited = NULL; |
2366 | void *res; | |
297a2110 | 2367 | unsigned int cnt = 0; |
4fd7a6de | 2368 | bool translated = false; |
dd277d48 | 2369 | |
02c74b9b | 2370 | timevar_push (TV_ALIAS_STMT_WALK); |
2371 | ||
dd277d48 | 2372 | do |
2373 | { | |
2374 | gimple def_stmt; | |
3857274c | 2375 | |
02c74b9b | 2376 | /* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */ |
297a2110 | 2377 | res = (*walker) (ref, vuse, cnt, data); |
2378 | /* Abort walk. */ | |
2379 | if (res == (void *)-1) | |
2380 | { | |
2381 | res = NULL; | |
2382 | break; | |
2383 | } | |
2384 | /* Lookup succeeded. */ | |
2385 | else if (res != NULL) | |
dd277d48 | 2386 | break; |
3857274c | 2387 | |
dd277d48 | 2388 | def_stmt = SSA_NAME_DEF_STMT (vuse); |
2389 | if (gimple_nop_p (def_stmt)) | |
2390 | break; | |
2391 | else if (gimple_code (def_stmt) == GIMPLE_PHI) | |
4fd7a6de | 2392 | vuse = get_continuation_for_phi (def_stmt, ref, &cnt, |
2393 | &visited, translated); | |
dd277d48 | 2394 | else |
2395 | { | |
297a2110 | 2396 | cnt++; |
3918bd18 | 2397 | if (stmt_may_clobber_ref_p_1 (def_stmt, ref)) |
d8021dea | 2398 | { |
2399 | if (!translate) | |
2400 | break; | |
3918bd18 | 2401 | res = (*translate) (ref, vuse, data); |
d8021dea | 2402 | /* Failed lookup and translation. */ |
2403 | if (res == (void *)-1) | |
2404 | { | |
2405 | res = NULL; | |
2406 | break; | |
2407 | } | |
2408 | /* Lookup succeeded. */ | |
2409 | else if (res != NULL) | |
2410 | break; | |
2411 | /* Translation succeeded, continue walking. */ | |
4fd7a6de | 2412 | translated = true; |
d8021dea | 2413 | } |
dd277d48 | 2414 | vuse = gimple_vuse (def_stmt); |
2415 | } | |
2416 | } | |
2417 | while (vuse); | |
ac926412 | 2418 | |
dd277d48 | 2419 | if (visited) |
2420 | BITMAP_FREE (visited); | |
ac926412 | 2421 | |
02c74b9b | 2422 | timevar_pop (TV_ALIAS_STMT_WALK); |
2423 | ||
dd277d48 | 2424 | return res; |
3857274c | 2425 | } |
2426 | ||
604eef2c | 2427 | |
dd277d48 | 2428 | /* Based on the memory reference REF call WALKER for each vdef which |
2429 | defining statement may clobber REF, starting with VDEF. If REF | |
2430 | is NULL_TREE, each defining statement is visited. | |
2431 | ||
2432 | WALKER is called with REF, the current vdef and DATA. If WALKER | |
2433 | returns true the walk is stopped, otherwise it continues. | |
2434 | ||
2435 | At PHI nodes walk_aliased_vdefs forks into one walk for reach | |
2436 | PHI argument (but only one walk continues on merge points), the | |
2437 | return value is true if any of the walks was successful. | |
2438 | ||
2439 | The function returns the number of statements walked. */ | |
604eef2c | 2440 | |
2441 | static unsigned int | |
1daead67 | 2442 | walk_aliased_vdefs_1 (ao_ref *ref, tree vdef, |
2443 | bool (*walker)(ao_ref *, tree, void *), void *data, | |
dd277d48 | 2444 | bitmap *visited, unsigned int cnt) |
604eef2c | 2445 | { |
dd277d48 | 2446 | do |
2447 | { | |
2448 | gimple def_stmt = SSA_NAME_DEF_STMT (vdef); | |
604eef2c | 2449 | |
dd277d48 | 2450 | if (*visited |
2451 | && !bitmap_set_bit (*visited, SSA_NAME_VERSION (vdef))) | |
2452 | return cnt; | |
2453 | ||
2454 | if (gimple_nop_p (def_stmt)) | |
2455 | return cnt; | |
2456 | else if (gimple_code (def_stmt) == GIMPLE_PHI) | |
2457 | { | |
2458 | unsigned i; | |
2459 | if (!*visited) | |
2460 | *visited = BITMAP_ALLOC (NULL); | |
2461 | for (i = 0; i < gimple_phi_num_args (def_stmt); ++i) | |
2462 | cnt += walk_aliased_vdefs_1 (ref, gimple_phi_arg_def (def_stmt, i), | |
2463 | walker, data, visited, 0); | |
2464 | return cnt; | |
2465 | } | |
2466 | ||
02c74b9b | 2467 | /* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */ |
dd277d48 | 2468 | cnt++; |
2469 | if ((!ref | |
1daead67 | 2470 | || stmt_may_clobber_ref_p_1 (def_stmt, ref)) |
dd277d48 | 2471 | && (*walker) (ref, vdef, data)) |
2472 | return cnt; | |
2473 | ||
2474 | vdef = gimple_vuse (def_stmt); | |
2475 | } | |
2476 | while (1); | |
604eef2c | 2477 | } |
2478 | ||
dd277d48 | 2479 | unsigned int |
1daead67 | 2480 | walk_aliased_vdefs (ao_ref *ref, tree vdef, |
2481 | bool (*walker)(ao_ref *, tree, void *), void *data, | |
dd277d48 | 2482 | bitmap *visited) |
df3f0669 | 2483 | { |
dd277d48 | 2484 | bitmap local_visited = NULL; |
2485 | unsigned int ret; | |
2486 | ||
02c74b9b | 2487 | timevar_push (TV_ALIAS_STMT_WALK); |
2488 | ||
dd277d48 | 2489 | ret = walk_aliased_vdefs_1 (ref, vdef, walker, data, |
2490 | visited ? visited : &local_visited, 0); | |
2491 | if (local_visited) | |
2492 | BITMAP_FREE (local_visited); | |
2493 | ||
02c74b9b | 2494 | timevar_pop (TV_ALIAS_STMT_WALK); |
2495 | ||
dd277d48 | 2496 | return ret; |
2497 | } | |
2498 |