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4ee9c684 | 1 | /* Alias analysis for trees. |
8e8f6434 | 2 | Copyright (C) 2004-2018 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" | |
9ef16211 | 24 | #include "backend.h" |
7c29e30e | 25 | #include "target.h" |
26 | #include "rtl.h" | |
4ee9c684 | 27 | #include "tree.h" |
9ef16211 | 28 | #include "gimple.h" |
7c29e30e | 29 | #include "timevar.h" /* for TV_ALIAS_STMT_WALK */ |
9ef16211 | 30 | #include "ssa.h" |
7c29e30e | 31 | #include "cgraph.h" |
32 | #include "tree-pretty-print.h" | |
9ef16211 | 33 | #include "alias.h" |
b20a8bb4 | 34 | #include "fold-const.h" |
94ea8568 | 35 | #include "langhooks.h" |
b9ed1410 | 36 | #include "dumpfile.h" |
bc61cadb | 37 | #include "tree-eh.h" |
073c1fd5 | 38 | #include "tree-dfa.h" |
dd9784d4 | 39 | #include "ipa-reference.h" |
76bc343a | 40 | #include "varasm.h" |
a55dc2cd | 41 | |
dd277d48 | 42 | /* Broad overview of how alias analysis on gimple works: |
4fb5e5ca | 43 | |
dd277d48 | 44 | Statements clobbering or using memory are linked through the |
45 | virtual operand factored use-def chain. The virtual operand | |
46 | is unique per function, its symbol is accessible via gimple_vop (cfun). | |
47 | Virtual operands are used for efficiently walking memory statements | |
48 | in the gimple IL and are useful for things like value-numbering as | |
49 | a generation count for memory references. | |
339d7079 | 50 | |
dd277d48 | 51 | SSA_NAME pointers may have associated points-to information |
52 | accessible via the SSA_NAME_PTR_INFO macro. Flow-insensitive | |
53 | points-to information is (re-)computed by the TODO_rebuild_alias | |
54 | pass manager todo. Points-to information is also used for more | |
55 | precise tracking of call-clobbered and call-used variables and | |
56 | related disambiguations. | |
339d7079 | 57 | |
dd277d48 | 58 | This file contains functions for disambiguating memory references, |
59 | the so called alias-oracle and tools for walking of the gimple IL. | |
339d7079 | 60 | |
dd277d48 | 61 | The main alias-oracle entry-points are |
339d7079 | 62 | |
24500bba | 63 | bool stmt_may_clobber_ref_p (gimple *, tree) |
339d7079 | 64 | |
dd277d48 | 65 | This function queries if a statement may invalidate (parts of) |
66 | the memory designated by the reference tree argument. | |
339d7079 | 67 | |
24500bba | 68 | bool ref_maybe_used_by_stmt_p (gimple *, tree) |
339d7079 | 69 | |
dd277d48 | 70 | This function queries if a statement may need (parts of) the |
71 | memory designated by the reference tree argument. | |
339d7079 | 72 | |
dd277d48 | 73 | There are variants of these functions that only handle the call |
74 | part of a statement, call_may_clobber_ref_p and ref_maybe_used_by_call_p. | |
75 | Note that these do not disambiguate against a possible call lhs. | |
339d7079 | 76 | |
dd277d48 | 77 | bool refs_may_alias_p (tree, tree) |
339d7079 | 78 | |
dd277d48 | 79 | This function tries to disambiguate two reference trees. |
05931b00 | 80 | |
dd277d48 | 81 | bool ptr_deref_may_alias_global_p (tree) |
339d7079 | 82 | |
dd277d48 | 83 | This function queries if dereferencing a pointer variable may |
84 | alias global memory. | |
339d7079 | 85 | |
dd277d48 | 86 | More low-level disambiguators are available and documented in |
87 | this file. Low-level disambiguators dealing with points-to | |
88 | information are in tree-ssa-structalias.c. */ | |
339d7079 | 89 | |
339d7079 | 90 | |
dd277d48 | 91 | /* Query statistics for the different low-level disambiguators. |
92 | A high-level query may trigger multiple of them. */ | |
339d7079 | 93 | |
dd277d48 | 94 | static struct { |
95 | unsigned HOST_WIDE_INT refs_may_alias_p_may_alias; | |
96 | unsigned HOST_WIDE_INT refs_may_alias_p_no_alias; | |
97 | unsigned HOST_WIDE_INT ref_maybe_used_by_call_p_may_alias; | |
98 | unsigned HOST_WIDE_INT ref_maybe_used_by_call_p_no_alias; | |
99 | unsigned HOST_WIDE_INT call_may_clobber_ref_p_may_alias; | |
100 | unsigned HOST_WIDE_INT call_may_clobber_ref_p_no_alias; | |
101 | } alias_stats; | |
339d7079 | 102 | |
dd277d48 | 103 | void |
104 | dump_alias_stats (FILE *s) | |
105 | { | |
106 | fprintf (s, "\nAlias oracle query stats:\n"); | |
107 | fprintf (s, " refs_may_alias_p: " | |
108 | HOST_WIDE_INT_PRINT_DEC" disambiguations, " | |
109 | HOST_WIDE_INT_PRINT_DEC" queries\n", | |
110 | alias_stats.refs_may_alias_p_no_alias, | |
111 | alias_stats.refs_may_alias_p_no_alias | |
112 | + alias_stats.refs_may_alias_p_may_alias); | |
113 | fprintf (s, " ref_maybe_used_by_call_p: " | |
114 | HOST_WIDE_INT_PRINT_DEC" disambiguations, " | |
115 | HOST_WIDE_INT_PRINT_DEC" queries\n", | |
116 | alias_stats.ref_maybe_used_by_call_p_no_alias, | |
117 | alias_stats.refs_may_alias_p_no_alias | |
118 | + alias_stats.ref_maybe_used_by_call_p_may_alias); | |
119 | fprintf (s, " call_may_clobber_ref_p: " | |
120 | HOST_WIDE_INT_PRINT_DEC" disambiguations, " | |
121 | HOST_WIDE_INT_PRINT_DEC" queries\n", | |
122 | alias_stats.call_may_clobber_ref_p_no_alias, | |
123 | alias_stats.call_may_clobber_ref_p_no_alias | |
124 | + alias_stats.call_may_clobber_ref_p_may_alias); | |
5b6bf098 | 125 | dump_alias_stats_in_alias_c (s); |
dd277d48 | 126 | } |
127 | ||
128 | ||
129 | /* Return true, if dereferencing PTR may alias with a global variable. */ | |
4ee9c684 | 130 | |
dd277d48 | 131 | bool |
132 | ptr_deref_may_alias_global_p (tree ptr) | |
4ee9c684 | 133 | { |
dd277d48 | 134 | struct ptr_info_def *pi; |
4fb5e5ca | 135 | |
dd277d48 | 136 | /* If we end up with a pointer constant here that may point |
137 | to global memory. */ | |
138 | if (TREE_CODE (ptr) != SSA_NAME) | |
139 | return true; | |
4ee9c684 | 140 | |
dd277d48 | 141 | pi = SSA_NAME_PTR_INFO (ptr); |
4ee9c684 | 142 | |
dd277d48 | 143 | /* If we do not have points-to information for this variable, |
144 | we have to punt. */ | |
145 | if (!pi) | |
146 | return true; | |
4ee9c684 | 147 | |
2a3ebafa | 148 | /* ??? This does not use TBAA to prune globals ptr may not access. */ |
dd277d48 | 149 | return pt_solution_includes_global (&pi->pt); |
4ee9c684 | 150 | } |
151 | ||
2a3ebafa | 152 | /* Return true if dereferencing PTR may alias DECL. |
153 | The caller is responsible for applying TBAA to see if PTR | |
154 | may access DECL at all. */ | |
4ee9c684 | 155 | |
dd277d48 | 156 | static bool |
157 | ptr_deref_may_alias_decl_p (tree ptr, tree decl) | |
4ee9c684 | 158 | { |
dd277d48 | 159 | struct ptr_info_def *pi; |
f7d118a9 | 160 | |
2760c0e3 | 161 | /* Conversions are irrelevant for points-to information and |
162 | data-dependence analysis can feed us those. */ | |
163 | STRIP_NOPS (ptr); | |
164 | ||
165 | /* Anything we do not explicilty handle aliases. */ | |
166 | if ((TREE_CODE (ptr) != SSA_NAME | |
167 | && TREE_CODE (ptr) != ADDR_EXPR | |
168 | && TREE_CODE (ptr) != POINTER_PLUS_EXPR) | |
169 | || !POINTER_TYPE_P (TREE_TYPE (ptr)) | |
53e9c5c4 | 170 | || (!VAR_P (decl) |
2760c0e3 | 171 | && TREE_CODE (decl) != PARM_DECL |
172 | && TREE_CODE (decl) != RESULT_DECL)) | |
9c01641d | 173 | return true; |
2fd0b5dc | 174 | |
2760c0e3 | 175 | /* Disregard pointer offsetting. */ |
176 | if (TREE_CODE (ptr) == POINTER_PLUS_EXPR) | |
177 | { | |
178 | do | |
179 | { | |
180 | ptr = TREE_OPERAND (ptr, 0); | |
181 | } | |
182 | while (TREE_CODE (ptr) == POINTER_PLUS_EXPR); | |
183 | return ptr_deref_may_alias_decl_p (ptr, decl); | |
184 | } | |
185 | ||
047fdd47 | 186 | /* ADDR_EXPR pointers either just offset another pointer or directly |
187 | specify the pointed-to set. */ | |
188 | if (TREE_CODE (ptr) == ADDR_EXPR) | |
189 | { | |
190 | tree base = get_base_address (TREE_OPERAND (ptr, 0)); | |
191 | if (base | |
2622064f | 192 | && (TREE_CODE (base) == MEM_REF |
193 | || TREE_CODE (base) == TARGET_MEM_REF)) | |
047fdd47 | 194 | ptr = TREE_OPERAND (base, 0); |
195 | else if (base | |
2622064f | 196 | && DECL_P (base)) |
96ba6770 | 197 | return compare_base_decls (base, decl) != 0; |
047fdd47 | 198 | else if (base |
199 | && CONSTANT_CLASS_P (base)) | |
200 | return false; | |
201 | else | |
202 | return true; | |
203 | } | |
204 | ||
2760c0e3 | 205 | /* Non-aliased variables can not be pointed to. */ |
206 | if (!may_be_aliased (decl)) | |
207 | return false; | |
047fdd47 | 208 | |
dd277d48 | 209 | /* If we do not have useful points-to information for this pointer |
210 | we cannot disambiguate anything else. */ | |
211 | pi = SSA_NAME_PTR_INFO (ptr); | |
212 | if (!pi) | |
2fd0b5dc | 213 | return true; |
214 | ||
dd277d48 | 215 | return pt_solution_includes (&pi->pt, decl); |
2fd0b5dc | 216 | } |
4ee9c684 | 217 | |
2a3ebafa | 218 | /* Return true if dereferenced PTR1 and PTR2 may alias. |
219 | The caller is responsible for applying TBAA to see if accesses | |
220 | through PTR1 and PTR2 may conflict at all. */ | |
4ee9c684 | 221 | |
2760c0e3 | 222 | bool |
dd277d48 | 223 | ptr_derefs_may_alias_p (tree ptr1, tree ptr2) |
4ee9c684 | 224 | { |
dd277d48 | 225 | struct ptr_info_def *pi1, *pi2; |
4ee9c684 | 226 | |
2760c0e3 | 227 | /* Conversions are irrelevant for points-to information and |
228 | data-dependence analysis can feed us those. */ | |
229 | STRIP_NOPS (ptr1); | |
230 | STRIP_NOPS (ptr2); | |
231 | ||
2760c0e3 | 232 | /* Disregard pointer offsetting. */ |
233 | if (TREE_CODE (ptr1) == POINTER_PLUS_EXPR) | |
234 | { | |
235 | do | |
236 | { | |
237 | ptr1 = TREE_OPERAND (ptr1, 0); | |
238 | } | |
239 | while (TREE_CODE (ptr1) == POINTER_PLUS_EXPR); | |
240 | return ptr_derefs_may_alias_p (ptr1, ptr2); | |
241 | } | |
242 | if (TREE_CODE (ptr2) == POINTER_PLUS_EXPR) | |
243 | { | |
244 | do | |
245 | { | |
246 | ptr2 = TREE_OPERAND (ptr2, 0); | |
247 | } | |
248 | while (TREE_CODE (ptr2) == POINTER_PLUS_EXPR); | |
249 | return ptr_derefs_may_alias_p (ptr1, ptr2); | |
250 | } | |
f85fb819 | 251 | |
047fdd47 | 252 | /* ADDR_EXPR pointers either just offset another pointer or directly |
253 | specify the pointed-to set. */ | |
254 | if (TREE_CODE (ptr1) == ADDR_EXPR) | |
255 | { | |
256 | tree base = get_base_address (TREE_OPERAND (ptr1, 0)); | |
257 | if (base | |
2622064f | 258 | && (TREE_CODE (base) == MEM_REF |
259 | || TREE_CODE (base) == TARGET_MEM_REF)) | |
80b4d93e | 260 | return ptr_derefs_may_alias_p (TREE_OPERAND (base, 0), ptr2); |
047fdd47 | 261 | else if (base |
2622064f | 262 | && DECL_P (base)) |
047fdd47 | 263 | return ptr_deref_may_alias_decl_p (ptr2, base); |
264 | else | |
265 | return true; | |
266 | } | |
267 | if (TREE_CODE (ptr2) == ADDR_EXPR) | |
268 | { | |
269 | tree base = get_base_address (TREE_OPERAND (ptr2, 0)); | |
270 | if (base | |
2622064f | 271 | && (TREE_CODE (base) == MEM_REF |
272 | || TREE_CODE (base) == TARGET_MEM_REF)) | |
80b4d93e | 273 | return ptr_derefs_may_alias_p (ptr1, TREE_OPERAND (base, 0)); |
047fdd47 | 274 | else if (base |
2622064f | 275 | && DECL_P (base)) |
047fdd47 | 276 | return ptr_deref_may_alias_decl_p (ptr1, base); |
277 | else | |
278 | return true; | |
279 | } | |
280 | ||
80b4d93e | 281 | /* From here we require SSA name pointers. Anything else aliases. */ |
282 | if (TREE_CODE (ptr1) != SSA_NAME | |
283 | || TREE_CODE (ptr2) != SSA_NAME | |
284 | || !POINTER_TYPE_P (TREE_TYPE (ptr1)) | |
285 | || !POINTER_TYPE_P (TREE_TYPE (ptr2))) | |
286 | return true; | |
287 | ||
dd277d48 | 288 | /* We may end up with two empty points-to solutions for two same pointers. |
289 | In this case we still want to say both pointers alias, so shortcut | |
290 | that here. */ | |
291 | if (ptr1 == ptr2) | |
292 | return true; | |
81d08033 | 293 | |
dd277d48 | 294 | /* If we do not have useful points-to information for either pointer |
295 | we cannot disambiguate anything else. */ | |
296 | pi1 = SSA_NAME_PTR_INFO (ptr1); | |
297 | pi2 = SSA_NAME_PTR_INFO (ptr2); | |
298 | if (!pi1 || !pi2) | |
299 | return true; | |
81d08033 | 300 | |
2a3ebafa | 301 | /* ??? This does not use TBAA to prune decls from the intersection |
302 | that not both pointers may access. */ | |
dd277d48 | 303 | return pt_solutions_intersect (&pi1->pt, &pi2->pt); |
81d08033 | 304 | } |
305 | ||
047fdd47 | 306 | /* Return true if dereferencing PTR may alias *REF. |
307 | The caller is responsible for applying TBAA to see if PTR | |
308 | may access *REF at all. */ | |
309 | ||
310 | static bool | |
311 | ptr_deref_may_alias_ref_p_1 (tree ptr, ao_ref *ref) | |
312 | { | |
313 | tree base = ao_ref_base (ref); | |
314 | ||
2622064f | 315 | if (TREE_CODE (base) == MEM_REF |
316 | || TREE_CODE (base) == TARGET_MEM_REF) | |
047fdd47 | 317 | return ptr_derefs_may_alias_p (ptr, TREE_OPERAND (base, 0)); |
2622064f | 318 | else if (DECL_P (base)) |
047fdd47 | 319 | return ptr_deref_may_alias_decl_p (ptr, base); |
320 | ||
321 | return true; | |
322 | } | |
323 | ||
73447cc5 | 324 | /* Returns true if PTR1 and PTR2 compare unequal because of points-to. */ |
325 | ||
326 | bool | |
327 | ptrs_compare_unequal (tree ptr1, tree ptr2) | |
328 | { | |
329 | /* First resolve the pointers down to a SSA name pointer base or | |
330 | a VAR_DECL, PARM_DECL or RESULT_DECL. This explicitely does | |
331 | not yet try to handle LABEL_DECLs, FUNCTION_DECLs, CONST_DECLs | |
332 | or STRING_CSTs which needs points-to adjustments to track them | |
333 | in the points-to sets. */ | |
334 | tree obj1 = NULL_TREE; | |
335 | tree obj2 = NULL_TREE; | |
336 | if (TREE_CODE (ptr1) == ADDR_EXPR) | |
337 | { | |
338 | tree tem = get_base_address (TREE_OPERAND (ptr1, 0)); | |
339 | if (! tem) | |
340 | return false; | |
53e9c5c4 | 341 | if (VAR_P (tem) |
73447cc5 | 342 | || TREE_CODE (tem) == PARM_DECL |
343 | || TREE_CODE (tem) == RESULT_DECL) | |
344 | obj1 = tem; | |
345 | else if (TREE_CODE (tem) == MEM_REF) | |
346 | ptr1 = TREE_OPERAND (tem, 0); | |
347 | } | |
348 | if (TREE_CODE (ptr2) == ADDR_EXPR) | |
349 | { | |
350 | tree tem = get_base_address (TREE_OPERAND (ptr2, 0)); | |
351 | if (! tem) | |
352 | return false; | |
53e9c5c4 | 353 | if (VAR_P (tem) |
73447cc5 | 354 | || TREE_CODE (tem) == PARM_DECL |
355 | || TREE_CODE (tem) == RESULT_DECL) | |
356 | obj2 = tem; | |
357 | else if (TREE_CODE (tem) == MEM_REF) | |
358 | ptr2 = TREE_OPERAND (tem, 0); | |
359 | } | |
360 | ||
c3f85235 | 361 | /* Canonicalize ptr vs. object. */ |
362 | if (TREE_CODE (ptr1) == SSA_NAME && obj2) | |
363 | { | |
364 | std::swap (ptr1, ptr2); | |
365 | std::swap (obj1, obj2); | |
366 | } | |
367 | ||
73447cc5 | 368 | if (obj1 && obj2) |
369 | /* Other code handles this correctly, no need to duplicate it here. */; | |
370 | else if (obj1 && TREE_CODE (ptr2) == SSA_NAME) | |
371 | { | |
372 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr2); | |
5ffb4a0d | 373 | /* We may not use restrict to optimize pointer comparisons. |
374 | See PR71062. So we have to assume that restrict-pointed-to | |
375 | may be in fact obj1. */ | |
76bc343a | 376 | if (!pi |
377 | || pi->pt.vars_contains_restrict | |
378 | || pi->pt.vars_contains_interposable) | |
73447cc5 | 379 | return false; |
c3f85235 | 380 | if (VAR_P (obj1) |
381 | && (TREE_STATIC (obj1) || DECL_EXTERNAL (obj1))) | |
382 | { | |
383 | varpool_node *node = varpool_node::get (obj1); | |
384 | /* If obj1 may bind to NULL give up (see below). */ | |
76bc343a | 385 | if (! node |
386 | || ! node->nonzero_address () | |
387 | || ! decl_binds_to_current_def_p (obj1)) | |
c3f85235 | 388 | return false; |
389 | } | |
73447cc5 | 390 | return !pt_solution_includes (&pi->pt, obj1); |
391 | } | |
73447cc5 | 392 | |
393 | /* ??? We'd like to handle ptr1 != NULL and ptr1 != ptr2 | |
394 | but those require pt.null to be conservatively correct. */ | |
395 | ||
396 | return false; | |
397 | } | |
398 | ||
258bd648 | 399 | /* Returns whether reference REF to BASE may refer to global memory. */ |
8763c223 | 400 | |
258bd648 | 401 | static bool |
402 | ref_may_alias_global_p_1 (tree base) | |
8763c223 | 403 | { |
8763c223 | 404 | if (DECL_P (base)) |
405 | return is_global_var (base); | |
406 | else if (TREE_CODE (base) == MEM_REF | |
407 | || TREE_CODE (base) == TARGET_MEM_REF) | |
408 | return ptr_deref_may_alias_global_p (TREE_OPERAND (base, 0)); | |
409 | return true; | |
410 | } | |
411 | ||
258bd648 | 412 | bool |
413 | ref_may_alias_global_p (ao_ref *ref) | |
414 | { | |
415 | tree base = ao_ref_base (ref); | |
416 | return ref_may_alias_global_p_1 (base); | |
417 | } | |
418 | ||
419 | bool | |
420 | ref_may_alias_global_p (tree ref) | |
421 | { | |
422 | tree base = get_base_address (ref); | |
423 | return ref_may_alias_global_p_1 (base); | |
424 | } | |
425 | ||
8763c223 | 426 | /* Return true whether STMT may clobber global memory. */ |
427 | ||
428 | bool | |
42acab1c | 429 | stmt_may_clobber_global_p (gimple *stmt) |
8763c223 | 430 | { |
431 | tree lhs; | |
432 | ||
433 | if (!gimple_vdef (stmt)) | |
434 | return false; | |
435 | ||
436 | /* ??? We can ask the oracle whether an artificial pointer | |
437 | dereference with a pointer with points-to information covering | |
438 | all global memory (what about non-address taken memory?) maybe | |
439 | clobbered by this call. As there is at the moment no convenient | |
440 | way of doing that without generating garbage do some manual | |
441 | checking instead. | |
442 | ??? We could make a NULL ao_ref argument to the various | |
443 | predicates special, meaning any global memory. */ | |
444 | ||
445 | switch (gimple_code (stmt)) | |
446 | { | |
447 | case GIMPLE_ASSIGN: | |
448 | lhs = gimple_assign_lhs (stmt); | |
449 | return (TREE_CODE (lhs) != SSA_NAME | |
450 | && ref_may_alias_global_p (lhs)); | |
451 | case GIMPLE_CALL: | |
452 | return true; | |
453 | default: | |
454 | return true; | |
455 | } | |
456 | } | |
457 | ||
4ee9c684 | 458 | |
459 | /* Dump alias information on FILE. */ | |
460 | ||
461 | void | |
462 | dump_alias_info (FILE *file) | |
463 | { | |
2aac21c5 | 464 | unsigned i; |
f211616e | 465 | tree ptr; |
4ee9c684 | 466 | const char *funcname |
5135beeb | 467 | = lang_hooks.decl_printable_name (current_function_decl, 2); |
a55dc2cd | 468 | tree var; |
4ee9c684 | 469 | |
dd277d48 | 470 | fprintf (file, "\n\nAlias information for %s\n\n", funcname); |
81d08033 | 471 | |
472 | fprintf (file, "Aliased symbols\n\n"); | |
48e1416a | 473 | |
2aac21c5 | 474 | FOR_EACH_LOCAL_DECL (cfun, i, var) |
81d08033 | 475 | { |
81d08033 | 476 | if (may_be_aliased (var)) |
477 | dump_variable (file, var); | |
478 | } | |
479 | ||
7f81b5ee | 480 | fprintf (file, "\nCall clobber information\n"); |
481 | ||
482 | fprintf (file, "\nESCAPED"); | |
483 | dump_points_to_solution (file, &cfun->gimple_df->escaped); | |
7f81b5ee | 484 | |
485 | fprintf (file, "\n\nFlow-insensitive points-to information\n\n"); | |
81d08033 | 486 | |
f211616e | 487 | FOR_EACH_SSA_NAME (i, ptr, cfun) |
81d08033 | 488 | { |
a48b1470 | 489 | struct ptr_info_def *pi; |
48e1416a | 490 | |
f211616e | 491 | if (!POINTER_TYPE_P (TREE_TYPE (ptr)) |
dd277d48 | 492 | || SSA_NAME_IN_FREE_LIST (ptr)) |
a48b1470 | 493 | continue; |
494 | ||
495 | pi = SSA_NAME_PTR_INFO (ptr); | |
dd277d48 | 496 | if (pi) |
81d08033 | 497 | dump_points_to_info_for (file, ptr); |
498 | } | |
4ee9c684 | 499 | |
4ee9c684 | 500 | fprintf (file, "\n"); |
501 | } | |
502 | ||
503 | ||
504 | /* Dump alias information on stderr. */ | |
505 | ||
4b987fac | 506 | DEBUG_FUNCTION void |
4ee9c684 | 507 | debug_alias_info (void) |
508 | { | |
509 | dump_alias_info (stderr); | |
510 | } | |
511 | ||
512 | ||
7f81b5ee | 513 | /* Dump the points-to set *PT into FILE. */ |
4ee9c684 | 514 | |
d793732c | 515 | void |
7f81b5ee | 516 | dump_points_to_solution (FILE *file, struct pt_solution *pt) |
4ee9c684 | 517 | { |
7f81b5ee | 518 | if (pt->anything) |
519 | fprintf (file, ", points-to anything"); | |
4ee9c684 | 520 | |
7f81b5ee | 521 | if (pt->nonlocal) |
522 | fprintf (file, ", points-to non-local"); | |
4ee9c684 | 523 | |
7f81b5ee | 524 | if (pt->escaped) |
525 | fprintf (file, ", points-to escaped"); | |
526 | ||
1a981e1a | 527 | if (pt->ipa_escaped) |
528 | fprintf (file, ", points-to unit escaped"); | |
529 | ||
7f81b5ee | 530 | if (pt->null) |
531 | fprintf (file, ", points-to NULL"); | |
532 | ||
533 | if (pt->vars) | |
4ee9c684 | 534 | { |
7f81b5ee | 535 | fprintf (file, ", points-to vars: "); |
536 | dump_decl_set (file, pt->vars); | |
420582bc | 537 | if (pt->vars_contains_nonlocal |
5ffb4a0d | 538 | || pt->vars_contains_escaped |
539 | || pt->vars_contains_escaped_heap | |
540 | || pt->vars_contains_restrict) | |
541 | { | |
542 | const char *comma = ""; | |
543 | fprintf (file, " ("); | |
544 | if (pt->vars_contains_nonlocal) | |
545 | { | |
546 | fprintf (file, "nonlocal"); | |
547 | comma = ", "; | |
548 | } | |
549 | if (pt->vars_contains_escaped) | |
550 | { | |
551 | fprintf (file, "%sescaped", comma); | |
552 | comma = ", "; | |
553 | } | |
554 | if (pt->vars_contains_escaped_heap) | |
555 | { | |
556 | fprintf (file, "%sescaped heap", comma); | |
557 | comma = ", "; | |
558 | } | |
559 | if (pt->vars_contains_restrict) | |
76bc343a | 560 | { |
561 | fprintf (file, "%srestrict", comma); | |
562 | comma = ", "; | |
563 | } | |
564 | if (pt->vars_contains_interposable) | |
565 | fprintf (file, "%sinterposable", comma); | |
5ffb4a0d | 566 | fprintf (file, ")"); |
567 | } | |
7f81b5ee | 568 | } |
569 | } | |
4ee9c684 | 570 | |
c7d89805 | 571 | |
572 | /* Unified dump function for pt_solution. */ | |
573 | ||
574 | DEBUG_FUNCTION void | |
575 | debug (pt_solution &ref) | |
576 | { | |
577 | dump_points_to_solution (stderr, &ref); | |
578 | } | |
579 | ||
580 | DEBUG_FUNCTION void | |
581 | debug (pt_solution *ptr) | |
582 | { | |
583 | if (ptr) | |
584 | debug (*ptr); | |
585 | else | |
586 | fprintf (stderr, "<nil>\n"); | |
587 | } | |
588 | ||
589 | ||
7f81b5ee | 590 | /* Dump points-to information for SSA_NAME PTR into FILE. */ |
4ee9c684 | 591 | |
7f81b5ee | 592 | void |
593 | dump_points_to_info_for (FILE *file, tree ptr) | |
594 | { | |
595 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr); | |
4ee9c684 | 596 | |
7f81b5ee | 597 | print_generic_expr (file, ptr, dump_flags); |
1e1a4c8c | 598 | |
7f81b5ee | 599 | if (pi) |
600 | dump_points_to_solution (file, &pi->pt); | |
601 | else | |
602 | fprintf (file, ", points-to anything"); | |
4ee9c684 | 603 | |
604 | fprintf (file, "\n"); | |
605 | } | |
606 | ||
607 | ||
d793732c | 608 | /* Dump points-to information for VAR into stderr. */ |
609 | ||
4b987fac | 610 | DEBUG_FUNCTION void |
d793732c | 611 | debug_points_to_info_for (tree var) |
612 | { | |
613 | dump_points_to_info_for (stderr, var); | |
614 | } | |
615 | ||
3918bd18 | 616 | |
617 | /* Initializes the alias-oracle reference representation *R from REF. */ | |
618 | ||
619 | void | |
620 | ao_ref_init (ao_ref *r, tree ref) | |
621 | { | |
622 | r->ref = ref; | |
623 | r->base = NULL_TREE; | |
624 | r->offset = 0; | |
625 | r->size = -1; | |
626 | r->max_size = -1; | |
627 | r->ref_alias_set = -1; | |
628 | r->base_alias_set = -1; | |
3787db52 | 629 | r->volatile_p = ref ? TREE_THIS_VOLATILE (ref) : false; |
3918bd18 | 630 | } |
631 | ||
632 | /* Returns the base object of the memory reference *REF. */ | |
633 | ||
634 | tree | |
635 | ao_ref_base (ao_ref *ref) | |
636 | { | |
292237f3 | 637 | bool reverse; |
638 | ||
3918bd18 | 639 | if (ref->base) |
640 | return ref->base; | |
f3c2a387 | 641 | ref->base = get_ref_base_and_extent (ref->ref, &ref->offset, &ref->size, |
642 | &ref->max_size, &reverse); | |
3918bd18 | 643 | return ref->base; |
644 | } | |
645 | ||
646 | /* Returns the base object alias set of the memory reference *REF. */ | |
647 | ||
8e92a5ee | 648 | alias_set_type |
3918bd18 | 649 | ao_ref_base_alias_set (ao_ref *ref) |
650 | { | |
182cf5a9 | 651 | tree base_ref; |
3918bd18 | 652 | if (ref->base_alias_set != -1) |
653 | return ref->base_alias_set; | |
182cf5a9 | 654 | if (!ref->ref) |
655 | return 0; | |
656 | base_ref = ref->ref; | |
657 | while (handled_component_p (base_ref)) | |
658 | base_ref = TREE_OPERAND (base_ref, 0); | |
659 | ref->base_alias_set = get_alias_set (base_ref); | |
3918bd18 | 660 | return ref->base_alias_set; |
661 | } | |
662 | ||
663 | /* Returns the reference alias set of the memory reference *REF. */ | |
664 | ||
665 | alias_set_type | |
666 | ao_ref_alias_set (ao_ref *ref) | |
667 | { | |
668 | if (ref->ref_alias_set != -1) | |
669 | return ref->ref_alias_set; | |
670 | ref->ref_alias_set = get_alias_set (ref->ref); | |
671 | return ref->ref_alias_set; | |
672 | } | |
673 | ||
134899ac | 674 | /* Init an alias-oracle reference representation from a gimple pointer |
234f1f79 | 675 | PTR and a gimple size SIZE in bytes. If SIZE is NULL_TREE then the |
134899ac | 676 | size is assumed to be unknown. The access is assumed to be only |
677 | to or after of the pointer target, not before it. */ | |
678 | ||
679 | void | |
680 | ao_ref_init_from_ptr_and_size (ao_ref *ref, tree ptr, tree size) | |
681 | { | |
773078cb | 682 | poly_int64 t, size_hwi, extra_offset = 0; |
134899ac | 683 | ref->ref = NULL_TREE; |
4e9e79c0 | 684 | if (TREE_CODE (ptr) == SSA_NAME) |
685 | { | |
42acab1c | 686 | gimple *stmt = SSA_NAME_DEF_STMT (ptr); |
4e9e79c0 | 687 | if (gimple_assign_single_p (stmt) |
688 | && gimple_assign_rhs_code (stmt) == ADDR_EXPR) | |
689 | ptr = gimple_assign_rhs1 (stmt); | |
e3ac92d2 | 690 | else if (is_gimple_assign (stmt) |
691 | && gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR | |
fe60c82c | 692 | && ptrdiff_tree_p (gimple_assign_rhs2 (stmt), &extra_offset)) |
e3ac92d2 | 693 | { |
694 | ptr = gimple_assign_rhs1 (stmt); | |
fe60c82c | 695 | extra_offset *= BITS_PER_UNIT; |
e3ac92d2 | 696 | } |
4e9e79c0 | 697 | } |
698 | ||
134899ac | 699 | if (TREE_CODE (ptr) == ADDR_EXPR) |
d1603825 | 700 | { |
701 | ref->base = get_addr_base_and_unit_offset (TREE_OPERAND (ptr, 0), &t); | |
702 | if (ref->base) | |
703 | ref->offset = BITS_PER_UNIT * t; | |
704 | else | |
705 | { | |
706 | size = NULL_TREE; | |
707 | ref->offset = 0; | |
708 | ref->base = get_base_address (TREE_OPERAND (ptr, 0)); | |
709 | } | |
710 | } | |
134899ac | 711 | else |
712 | { | |
7d39dbf6 | 713 | gcc_assert (POINTER_TYPE_P (TREE_TYPE (ptr))); |
182cf5a9 | 714 | ref->base = build2 (MEM_REF, char_type_node, |
2512209b | 715 | ptr, null_pointer_node); |
134899ac | 716 | ref->offset = 0; |
717 | } | |
e3ac92d2 | 718 | ref->offset += extra_offset; |
134899ac | 719 | if (size |
fe60c82c | 720 | && poly_int_tree_p (size, &size_hwi) |
721 | && coeffs_in_range_p (size_hwi, 0, HOST_WIDE_INT_MAX / BITS_PER_UNIT)) | |
dd49bf5f | 722 | ref->max_size = ref->size = size_hwi * BITS_PER_UNIT; |
134899ac | 723 | else |
724 | ref->max_size = ref->size = -1; | |
725 | ref->ref_alias_set = 0; | |
726 | ref->base_alias_set = 0; | |
3787db52 | 727 | ref->volatile_p = false; |
134899ac | 728 | } |
729 | ||
dd277d48 | 730 | /* Return 1 if TYPE1 and TYPE2 are to be considered equivalent for the |
731 | purpose of TBAA. Return 0 if they are distinct and -1 if we cannot | |
732 | decide. */ | |
d793732c | 733 | |
dd277d48 | 734 | static inline int |
735 | same_type_for_tbaa (tree type1, tree type2) | |
736 | { | |
737 | type1 = TYPE_MAIN_VARIANT (type1); | |
738 | type2 = TYPE_MAIN_VARIANT (type2); | |
4ee9c684 | 739 | |
dd277d48 | 740 | /* If we would have to do structural comparison bail out. */ |
741 | if (TYPE_STRUCTURAL_EQUALITY_P (type1) | |
742 | || TYPE_STRUCTURAL_EQUALITY_P (type2)) | |
743 | return -1; | |
744 | ||
745 | /* Compare the canonical types. */ | |
746 | if (TYPE_CANONICAL (type1) == TYPE_CANONICAL (type2)) | |
747 | return 1; | |
748 | ||
4b4d1513 | 749 | /* ??? Array types are not properly unified in all cases as we have |
dd277d48 | 750 | spurious changes in the index types for example. Removing this |
751 | causes all sorts of problems with the Fortran frontend. */ | |
752 | if (TREE_CODE (type1) == ARRAY_TYPE | |
753 | && TREE_CODE (type2) == ARRAY_TYPE) | |
754 | return -1; | |
755 | ||
102bfc9c | 756 | /* ??? In Ada, an lvalue of an unconstrained type can be used to access an |
757 | object of one of its constrained subtypes, e.g. when a function with an | |
758 | unconstrained parameter passed by reference is called on an object and | |
759 | inlined. But, even in the case of a fixed size, type and subtypes are | |
760 | not equivalent enough as to share the same TYPE_CANONICAL, since this | |
761 | would mean that conversions between them are useless, whereas they are | |
762 | not (e.g. type and subtypes can have different modes). So, in the end, | |
763 | they are only guaranteed to have the same alias set. */ | |
764 | if (get_alias_set (type1) == get_alias_set (type2)) | |
4b4d1513 | 765 | return -1; |
766 | ||
dd277d48 | 767 | /* The types are known to be not equal. */ |
768 | return 0; | |
769 | } | |
770 | ||
771 | /* Determine if the two component references REF1 and REF2 which are | |
772 | based on access types TYPE1 and TYPE2 and of which at least one is based | |
ac30e3b2 | 773 | on an indirect reference may alias. REF2 is the only one that can |
774 | be a decl in which case REF2_IS_DECL is true. | |
775 | REF1_ALIAS_SET, BASE1_ALIAS_SET, REF2_ALIAS_SET and BASE2_ALIAS_SET | |
776 | are the respective alias sets. */ | |
dd277d48 | 777 | |
778 | static bool | |
0d2f7431 | 779 | aliasing_component_refs_p (tree ref1, |
ac30e3b2 | 780 | alias_set_type ref1_alias_set, |
781 | alias_set_type base1_alias_set, | |
fe60c82c | 782 | poly_int64 offset1, poly_int64 max_size1, |
0d2f7431 | 783 | tree ref2, |
ac30e3b2 | 784 | alias_set_type ref2_alias_set, |
785 | alias_set_type base2_alias_set, | |
fe60c82c | 786 | poly_int64 offset2, poly_int64 max_size2, |
ac30e3b2 | 787 | bool ref2_is_decl) |
dd277d48 | 788 | { |
789 | /* If one reference is a component references through pointers try to find a | |
790 | common base and apply offset based disambiguation. This handles | |
791 | for example | |
792 | struct A { int i; int j; } *q; | |
793 | struct B { struct A a; int k; } *p; | |
794 | disambiguating q->i and p->a.j. */ | |
0d2f7431 | 795 | tree base1, base2; |
796 | tree type1, type2; | |
dd277d48 | 797 | tree *refp; |
798 | int same_p; | |
799 | ||
0d2f7431 | 800 | /* Choose bases and base types to search for. */ |
801 | base1 = ref1; | |
802 | while (handled_component_p (base1)) | |
803 | base1 = TREE_OPERAND (base1, 0); | |
804 | type1 = TREE_TYPE (base1); | |
805 | base2 = ref2; | |
806 | while (handled_component_p (base2)) | |
807 | base2 = TREE_OPERAND (base2, 0); | |
808 | type2 = TREE_TYPE (base2); | |
809 | ||
dd277d48 | 810 | /* Now search for the type1 in the access path of ref2. This |
811 | would be a common base for doing offset based disambiguation on. */ | |
bc3c318e | 812 | refp = &ref2; |
dd277d48 | 813 | while (handled_component_p (*refp) |
814 | && same_type_for_tbaa (TREE_TYPE (*refp), type1) == 0) | |
815 | refp = &TREE_OPERAND (*refp, 0); | |
816 | same_p = same_type_for_tbaa (TREE_TYPE (*refp), type1); | |
817 | /* If we couldn't compare types we have to bail out. */ | |
818 | if (same_p == -1) | |
819 | return true; | |
820 | else if (same_p == 1) | |
821 | { | |
f3c2a387 | 822 | poly_int64 offadj, sztmp, msztmp; |
292237f3 | 823 | bool reverse; |
824 | get_ref_base_and_extent (*refp, &offadj, &sztmp, &msztmp, &reverse); | |
dd277d48 | 825 | offset2 -= offadj; |
292237f3 | 826 | get_ref_base_and_extent (base1, &offadj, &sztmp, &msztmp, &reverse); |
0d2f7431 | 827 | offset1 -= offadj; |
fe60c82c | 828 | return ranges_maybe_overlap_p (offset1, max_size1, offset2, max_size2); |
dd277d48 | 829 | } |
830 | /* If we didn't find a common base, try the other way around. */ | |
bc3c318e | 831 | refp = &ref1; |
dd277d48 | 832 | while (handled_component_p (*refp) |
833 | && same_type_for_tbaa (TREE_TYPE (*refp), type2) == 0) | |
834 | refp = &TREE_OPERAND (*refp, 0); | |
835 | same_p = same_type_for_tbaa (TREE_TYPE (*refp), type2); | |
836 | /* If we couldn't compare types we have to bail out. */ | |
837 | if (same_p == -1) | |
838 | return true; | |
839 | else if (same_p == 1) | |
840 | { | |
f3c2a387 | 841 | poly_int64 offadj, sztmp, msztmp; |
292237f3 | 842 | bool reverse; |
843 | get_ref_base_and_extent (*refp, &offadj, &sztmp, &msztmp, &reverse); | |
dd277d48 | 844 | offset1 -= offadj; |
292237f3 | 845 | get_ref_base_and_extent (base2, &offadj, &sztmp, &msztmp, &reverse); |
0d2f7431 | 846 | offset2 -= offadj; |
fe60c82c | 847 | return ranges_maybe_overlap_p (offset1, max_size1, offset2, max_size2); |
dd277d48 | 848 | } |
ac30e3b2 | 849 | |
4b4d1513 | 850 | /* If we have two type access paths B1.path1 and B2.path2 they may |
ac30e3b2 | 851 | only alias if either B1 is in B2.path2 or B2 is in B1.path1. |
852 | But we can still have a path that goes B1.path1...B2.path2 with | |
853 | a part that we do not see. So we can only disambiguate now | |
854 | if there is no B2 in the tail of path1 and no B1 on the | |
855 | tail of path2. */ | |
856 | if (base1_alias_set == ref2_alias_set | |
857 | || alias_set_subset_of (base1_alias_set, ref2_alias_set)) | |
858 | return true; | |
859 | /* If this is ptr vs. decl then we know there is no ptr ... decl path. */ | |
860 | if (!ref2_is_decl) | |
861 | return (base2_alias_set == ref1_alias_set | |
862 | || alias_set_subset_of (base2_alias_set, ref1_alias_set)); | |
4b4d1513 | 863 | return false; |
dd277d48 | 864 | } |
865 | ||
740a2cb6 | 866 | /* Return true if we can determine that component references REF1 and REF2, |
867 | that are within a common DECL, cannot overlap. */ | |
868 | ||
869 | static bool | |
870 | nonoverlapping_component_refs_of_decl_p (tree ref1, tree ref2) | |
871 | { | |
4997014d | 872 | auto_vec<tree, 16> component_refs1; |
873 | auto_vec<tree, 16> component_refs2; | |
740a2cb6 | 874 | |
875 | /* Create the stack of handled components for REF1. */ | |
876 | while (handled_component_p (ref1)) | |
877 | { | |
878 | component_refs1.safe_push (ref1); | |
879 | ref1 = TREE_OPERAND (ref1, 0); | |
880 | } | |
881 | if (TREE_CODE (ref1) == MEM_REF) | |
882 | { | |
883 | if (!integer_zerop (TREE_OPERAND (ref1, 1))) | |
0e898e8a | 884 | return false; |
740a2cb6 | 885 | ref1 = TREE_OPERAND (TREE_OPERAND (ref1, 0), 0); |
886 | } | |
887 | ||
888 | /* Create the stack of handled components for REF2. */ | |
889 | while (handled_component_p (ref2)) | |
890 | { | |
891 | component_refs2.safe_push (ref2); | |
892 | ref2 = TREE_OPERAND (ref2, 0); | |
893 | } | |
894 | if (TREE_CODE (ref2) == MEM_REF) | |
895 | { | |
896 | if (!integer_zerop (TREE_OPERAND (ref2, 1))) | |
0e898e8a | 897 | return false; |
740a2cb6 | 898 | ref2 = TREE_OPERAND (TREE_OPERAND (ref2, 0), 0); |
899 | } | |
900 | ||
96ba6770 | 901 | /* Bases must be either same or uncomparable. */ |
902 | gcc_checking_assert (ref1 == ref2 | |
903 | || (DECL_P (ref1) && DECL_P (ref2) | |
904 | && compare_base_decls (ref1, ref2) != 0)); | |
740a2cb6 | 905 | |
906 | /* Pop the stacks in parallel and examine the COMPONENT_REFs of the same | |
907 | rank. This is sufficient because we start from the same DECL and you | |
908 | cannot reference several fields at a time with COMPONENT_REFs (unlike | |
909 | with ARRAY_RANGE_REFs for arrays) so you always need the same number | |
910 | of them to access a sub-component, unless you're in a union, in which | |
911 | case the return value will precisely be false. */ | |
912 | while (true) | |
913 | { | |
914 | do | |
915 | { | |
916 | if (component_refs1.is_empty ()) | |
0e898e8a | 917 | return false; |
740a2cb6 | 918 | ref1 = component_refs1.pop (); |
919 | } | |
920 | while (!RECORD_OR_UNION_TYPE_P (TREE_TYPE (TREE_OPERAND (ref1, 0)))); | |
921 | ||
922 | do | |
923 | { | |
924 | if (component_refs2.is_empty ()) | |
0e898e8a | 925 | return false; |
740a2cb6 | 926 | ref2 = component_refs2.pop (); |
927 | } | |
928 | while (!RECORD_OR_UNION_TYPE_P (TREE_TYPE (TREE_OPERAND (ref2, 0)))); | |
929 | ||
930 | /* Beware of BIT_FIELD_REF. */ | |
931 | if (TREE_CODE (ref1) != COMPONENT_REF | |
932 | || TREE_CODE (ref2) != COMPONENT_REF) | |
0e898e8a | 933 | return false; |
740a2cb6 | 934 | |
935 | tree field1 = TREE_OPERAND (ref1, 1); | |
936 | tree field2 = TREE_OPERAND (ref2, 1); | |
937 | ||
938 | /* ??? We cannot simply use the type of operand #0 of the refs here | |
939 | as the Fortran compiler smuggles type punning into COMPONENT_REFs | |
940 | for common blocks instead of using unions like everyone else. */ | |
608927af | 941 | tree type1 = DECL_CONTEXT (field1); |
942 | tree type2 = DECL_CONTEXT (field2); | |
740a2cb6 | 943 | |
944 | /* We cannot disambiguate fields in a union or qualified union. */ | |
945 | if (type1 != type2 || TREE_CODE (type1) != RECORD_TYPE) | |
0e898e8a | 946 | return false; |
740a2cb6 | 947 | |
740a2cb6 | 948 | if (field1 != field2) |
949 | { | |
ba1b6a59 | 950 | /* A field and its representative need to be considered the |
951 | same. */ | |
952 | if (DECL_BIT_FIELD_REPRESENTATIVE (field1) == field2 | |
953 | || DECL_BIT_FIELD_REPRESENTATIVE (field2) == field1) | |
954 | return false; | |
955 | /* Different fields of the same record type cannot overlap. | |
956 | ??? Bitfields can overlap at RTL level so punt on them. */ | |
957 | if (DECL_BIT_FIELD (field1) && DECL_BIT_FIELD (field2)) | |
958 | return false; | |
959 | return true; | |
740a2cb6 | 960 | } |
961 | } | |
962 | ||
740a2cb6 | 963 | return false; |
964 | } | |
965 | ||
f270d2a0 | 966 | /* qsort compare function to sort FIELD_DECLs after their |
967 | DECL_FIELD_CONTEXT TYPE_UID. */ | |
968 | ||
969 | static inline int | |
970 | ncr_compar (const void *field1_, const void *field2_) | |
971 | { | |
972 | const_tree field1 = *(const_tree *) const_cast <void *>(field1_); | |
973 | const_tree field2 = *(const_tree *) const_cast <void *>(field2_); | |
608927af | 974 | unsigned int uid1 = TYPE_UID (DECL_FIELD_CONTEXT (field1)); |
975 | unsigned int uid2 = TYPE_UID (DECL_FIELD_CONTEXT (field2)); | |
f270d2a0 | 976 | if (uid1 < uid2) |
977 | return -1; | |
978 | else if (uid1 > uid2) | |
979 | return 1; | |
980 | return 0; | |
981 | } | |
982 | ||
983 | /* Return true if we can determine that the fields referenced cannot | |
984 | overlap for any pair of objects. */ | |
985 | ||
986 | static bool | |
987 | nonoverlapping_component_refs_p (const_tree x, const_tree y) | |
988 | { | |
989 | if (!flag_strict_aliasing | |
990 | || !x || !y | |
991 | || TREE_CODE (x) != COMPONENT_REF | |
992 | || TREE_CODE (y) != COMPONENT_REF) | |
993 | return false; | |
994 | ||
995 | auto_vec<const_tree, 16> fieldsx; | |
996 | while (TREE_CODE (x) == COMPONENT_REF) | |
997 | { | |
998 | tree field = TREE_OPERAND (x, 1); | |
608927af | 999 | tree type = DECL_FIELD_CONTEXT (field); |
f270d2a0 | 1000 | if (TREE_CODE (type) == RECORD_TYPE) |
1001 | fieldsx.safe_push (field); | |
1002 | x = TREE_OPERAND (x, 0); | |
1003 | } | |
1004 | if (fieldsx.length () == 0) | |
1005 | return false; | |
1006 | auto_vec<const_tree, 16> fieldsy; | |
1007 | while (TREE_CODE (y) == COMPONENT_REF) | |
1008 | { | |
1009 | tree field = TREE_OPERAND (y, 1); | |
608927af | 1010 | tree type = DECL_FIELD_CONTEXT (field); |
f270d2a0 | 1011 | if (TREE_CODE (type) == RECORD_TYPE) |
1012 | fieldsy.safe_push (TREE_OPERAND (y, 1)); | |
1013 | y = TREE_OPERAND (y, 0); | |
1014 | } | |
1015 | if (fieldsy.length () == 0) | |
1016 | return false; | |
1017 | ||
1018 | /* Most common case first. */ | |
1019 | if (fieldsx.length () == 1 | |
1020 | && fieldsy.length () == 1) | |
608927af | 1021 | return ((DECL_FIELD_CONTEXT (fieldsx[0]) |
1022 | == DECL_FIELD_CONTEXT (fieldsy[0])) | |
f270d2a0 | 1023 | && fieldsx[0] != fieldsy[0] |
1024 | && !(DECL_BIT_FIELD (fieldsx[0]) && DECL_BIT_FIELD (fieldsy[0]))); | |
1025 | ||
1026 | if (fieldsx.length () == 2) | |
1027 | { | |
1028 | if (ncr_compar (&fieldsx[0], &fieldsx[1]) == 1) | |
a4f59596 | 1029 | std::swap (fieldsx[0], fieldsx[1]); |
f270d2a0 | 1030 | } |
1031 | else | |
1032 | fieldsx.qsort (ncr_compar); | |
1033 | ||
1034 | if (fieldsy.length () == 2) | |
1035 | { | |
1036 | if (ncr_compar (&fieldsy[0], &fieldsy[1]) == 1) | |
a4f59596 | 1037 | std::swap (fieldsy[0], fieldsy[1]); |
f270d2a0 | 1038 | } |
1039 | else | |
1040 | fieldsy.qsort (ncr_compar); | |
1041 | ||
1042 | unsigned i = 0, j = 0; | |
1043 | do | |
1044 | { | |
1045 | const_tree fieldx = fieldsx[i]; | |
1046 | const_tree fieldy = fieldsy[j]; | |
608927af | 1047 | tree typex = DECL_FIELD_CONTEXT (fieldx); |
1048 | tree typey = DECL_FIELD_CONTEXT (fieldy); | |
f270d2a0 | 1049 | if (typex == typey) |
1050 | { | |
1051 | /* We're left with accessing different fields of a structure, | |
ba1b6a59 | 1052 | no possible overlap. */ |
f270d2a0 | 1053 | if (fieldx != fieldy) |
ba1b6a59 | 1054 | { |
1055 | /* A field and its representative need to be considered the | |
1056 | same. */ | |
1057 | if (DECL_BIT_FIELD_REPRESENTATIVE (fieldx) == fieldy | |
1058 | || DECL_BIT_FIELD_REPRESENTATIVE (fieldy) == fieldx) | |
1059 | return false; | |
1060 | /* Different fields of the same record type cannot overlap. | |
1061 | ??? Bitfields can overlap at RTL level so punt on them. */ | |
1062 | if (DECL_BIT_FIELD (fieldx) && DECL_BIT_FIELD (fieldy)) | |
1063 | return false; | |
1064 | return true; | |
1065 | } | |
f270d2a0 | 1066 | } |
1067 | if (TYPE_UID (typex) < TYPE_UID (typey)) | |
1068 | { | |
1069 | i++; | |
1070 | if (i == fieldsx.length ()) | |
1071 | break; | |
1072 | } | |
1073 | else | |
1074 | { | |
1075 | j++; | |
1076 | if (j == fieldsy.length ()) | |
1077 | break; | |
1078 | } | |
1079 | } | |
1080 | while (1); | |
1081 | ||
1082 | return false; | |
1083 | } | |
1084 | ||
1085 | ||
dd277d48 | 1086 | /* Return true if two memory references based on the variables BASE1 |
077ad5ad | 1087 | and BASE2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and |
740a2cb6 | 1088 | [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. REF1 and REF2 |
1089 | if non-NULL are the complete memory reference trees. */ | |
dd277d48 | 1090 | |
1091 | static bool | |
740a2cb6 | 1092 | decl_refs_may_alias_p (tree ref1, tree base1, |
fe60c82c | 1093 | poly_int64 offset1, poly_int64 max_size1, |
740a2cb6 | 1094 | tree ref2, tree base2, |
fe60c82c | 1095 | poly_int64 offset2, poly_int64 max_size2) |
4ee9c684 | 1096 | { |
2622064f | 1097 | gcc_checking_assert (DECL_P (base1) && DECL_P (base2)); |
4ee9c684 | 1098 | |
dd277d48 | 1099 | /* If both references are based on different variables, they cannot alias. */ |
8e9b8d10 | 1100 | if (compare_base_decls (base1, base2) == 0) |
dd277d48 | 1101 | return false; |
4ee9c684 | 1102 | |
dd277d48 | 1103 | /* If both references are based on the same variable, they cannot alias if |
1104 | the accesses do not overlap. */ | |
fe60c82c | 1105 | if (!ranges_maybe_overlap_p (offset1, max_size1, offset2, max_size2)) |
740a2cb6 | 1106 | return false; |
1107 | ||
1108 | /* For components with variable position, the above test isn't sufficient, | |
1109 | so we disambiguate component references manually. */ | |
1110 | if (ref1 && ref2 | |
1111 | && handled_component_p (ref1) && handled_component_p (ref2) | |
1112 | && nonoverlapping_component_refs_of_decl_p (ref1, ref2)) | |
1113 | return false; | |
1114 | ||
1115 | return true; | |
dd277d48 | 1116 | } |
1117 | ||
1118 | /* Return true if an indirect reference based on *PTR1 constrained | |
077ad5ad | 1119 | to [OFFSET1, OFFSET1 + MAX_SIZE1) may alias a variable based on BASE2 |
1120 | constrained to [OFFSET2, OFFSET2 + MAX_SIZE2). *PTR1 and BASE2 have | |
dd277d48 | 1121 | the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1 |
1122 | in which case they are computed on-demand. REF1 and REF2 | |
1123 | if non-NULL are the complete memory reference trees. */ | |
1124 | ||
1125 | static bool | |
182cf5a9 | 1126 | indirect_ref_may_alias_decl_p (tree ref1 ATTRIBUTE_UNUSED, tree base1, |
fe60c82c | 1127 | poly_int64 offset1, poly_int64 max_size1, |
ac30e3b2 | 1128 | alias_set_type ref1_alias_set, |
dd277d48 | 1129 | alias_set_type base1_alias_set, |
182cf5a9 | 1130 | tree ref2 ATTRIBUTE_UNUSED, tree base2, |
fe60c82c | 1131 | poly_int64 offset2, poly_int64 max_size2, |
ac30e3b2 | 1132 | alias_set_type ref2_alias_set, |
182cf5a9 | 1133 | alias_set_type base2_alias_set, bool tbaa_p) |
dd277d48 | 1134 | { |
9a14ba4f | 1135 | tree ptr1; |
061b1263 | 1136 | tree ptrtype1, dbase2; |
2622064f | 1137 | |
1138 | gcc_checking_assert ((TREE_CODE (base1) == MEM_REF | |
1139 | || TREE_CODE (base1) == TARGET_MEM_REF) | |
1140 | && DECL_P (base2)); | |
182cf5a9 | 1141 | |
28daba6f | 1142 | ptr1 = TREE_OPERAND (base1, 0); |
90ca1268 | 1143 | poly_offset_int moff = mem_ref_offset (base1) << LOG2_BITS_PER_UNIT; |
182cf5a9 | 1144 | |
dd277d48 | 1145 | /* If only one reference is based on a variable, they cannot alias if |
1146 | the pointer access is beyond the extent of the variable access. | |
1147 | (the pointer base cannot validly point to an offset less than zero | |
1148 | of the variable). | |
a07f6629 | 1149 | ??? IVOPTs creates bases that do not honor this restriction, |
1150 | so do not apply this optimization for TARGET_MEM_REFs. */ | |
1151 | if (TREE_CODE (base1) != TARGET_MEM_REF | |
ecc647e7 | 1152 | && !ranges_maybe_overlap_p (offset1 + moff, -1, offset2, max_size2)) |
dd277d48 | 1153 | return false; |
a07f6629 | 1154 | /* They also cannot alias if the pointer may not point to the decl. */ |
dd277d48 | 1155 | if (!ptr_deref_may_alias_decl_p (ptr1, base2)) |
1156 | return false; | |
1157 | ||
1158 | /* Disambiguations that rely on strict aliasing rules follow. */ | |
182cf5a9 | 1159 | if (!flag_strict_aliasing || !tbaa_p) |
dd277d48 | 1160 | return true; |
1161 | ||
2622064f | 1162 | ptrtype1 = TREE_TYPE (TREE_OPERAND (base1, 1)); |
182cf5a9 | 1163 | |
dd277d48 | 1164 | /* If the alias set for a pointer access is zero all bets are off. */ |
dd277d48 | 1165 | if (base1_alias_set == 0) |
1166 | return true; | |
dd277d48 | 1167 | |
182cf5a9 | 1168 | /* When we are trying to disambiguate an access with a pointer dereference |
1169 | as base versus one with a decl as base we can use both the size | |
1170 | of the decl and its dynamic type for extra disambiguation. | |
1171 | ??? We do not know anything about the dynamic type of the decl | |
1172 | other than that its alias-set contains base2_alias_set as a subset | |
1173 | which does not help us here. */ | |
1174 | /* As we know nothing useful about the dynamic type of the decl just | |
1175 | use the usual conflict check rather than a subset test. | |
1176 | ??? We could introduce -fvery-strict-aliasing when the language | |
1177 | does not allow decls to have a dynamic type that differs from their | |
1178 | static type. Then we can check | |
1179 | !alias_set_subset_of (base1_alias_set, base2_alias_set) instead. */ | |
dd277d48 | 1180 | if (base1_alias_set != base2_alias_set |
182cf5a9 | 1181 | && !alias_sets_conflict_p (base1_alias_set, base2_alias_set)) |
1182 | return false; | |
1183 | /* If the size of the access relevant for TBAA through the pointer | |
1184 | is bigger than the size of the decl we can't possibly access the | |
1185 | decl via that pointer. */ | |
1186 | if (DECL_SIZE (base2) && COMPLETE_TYPE_P (TREE_TYPE (ptrtype1)) | |
fe60c82c | 1187 | && poly_int_tree_p (DECL_SIZE (base2)) |
1188 | && poly_int_tree_p (TYPE_SIZE (TREE_TYPE (ptrtype1))) | |
182cf5a9 | 1189 | /* ??? This in turn may run afoul when a decl of type T which is |
1190 | a member of union type U is accessed through a pointer to | |
1191 | type U and sizeof T is smaller than sizeof U. */ | |
1192 | && TREE_CODE (TREE_TYPE (ptrtype1)) != UNION_TYPE | |
1193 | && TREE_CODE (TREE_TYPE (ptrtype1)) != QUAL_UNION_TYPE | |
fe60c82c | 1194 | && known_lt (wi::to_poly_widest (DECL_SIZE (base2)), |
1195 | wi::to_poly_widest (TYPE_SIZE (TREE_TYPE (ptrtype1))))) | |
dd277d48 | 1196 | return false; |
1197 | ||
061b1263 | 1198 | if (!ref2) |
1199 | return true; | |
1200 | ||
a07f6629 | 1201 | /* If the decl is accessed via a MEM_REF, reconstruct the base |
061b1263 | 1202 | we can use for TBAA and an appropriately adjusted offset. */ |
1203 | dbase2 = ref2; | |
1204 | while (handled_component_p (dbase2)) | |
1205 | dbase2 = TREE_OPERAND (dbase2, 0); | |
fe60c82c | 1206 | poly_int64 doffset1 = offset1; |
1207 | poly_offset_int doffset2 = offset2; | |
061b1263 | 1208 | if (TREE_CODE (dbase2) == MEM_REF |
1209 | || TREE_CODE (dbase2) == TARGET_MEM_REF) | |
ecc647e7 | 1210 | doffset2 -= mem_ref_offset (dbase2) << LOG2_BITS_PER_UNIT; |
061b1263 | 1211 | |
1212 | /* If either reference is view-converted, give up now. */ | |
1213 | if (same_type_for_tbaa (TREE_TYPE (base1), TREE_TYPE (ptrtype1)) != 1 | |
5ef4302d | 1214 | || same_type_for_tbaa (TREE_TYPE (dbase2), TREE_TYPE (base2)) != 1) |
061b1263 | 1215 | return true; |
1216 | ||
1217 | /* If both references are through the same type, they do not alias | |
1218 | if the accesses do not overlap. This does extra disambiguation | |
1219 | for mixed/pointer accesses but requires strict aliasing. | |
1220 | For MEM_REFs we require that the component-ref offset we computed | |
1221 | is relative to the start of the type which we ensure by | |
1222 | comparing rvalue and access type and disregarding the constant | |
1223 | pointer offset. */ | |
1224 | if ((TREE_CODE (base1) != TARGET_MEM_REF | |
1225 | || (!TMR_INDEX (base1) && !TMR_INDEX2 (base1))) | |
1226 | && same_type_for_tbaa (TREE_TYPE (base1), TREE_TYPE (dbase2)) == 1) | |
ecc647e7 | 1227 | return ranges_maybe_overlap_p (doffset1, max_size1, doffset2, max_size2); |
061b1263 | 1228 | |
f270d2a0 | 1229 | if (ref1 && ref2 |
1230 | && nonoverlapping_component_refs_p (ref1, ref2)) | |
1231 | return false; | |
1232 | ||
dd277d48 | 1233 | /* Do access-path based disambiguation. */ |
1234 | if (ref1 && ref2 | |
061b1263 | 1235 | && (handled_component_p (ref1) || handled_component_p (ref2))) |
0d2f7431 | 1236 | return aliasing_component_refs_p (ref1, |
ac30e3b2 | 1237 | ref1_alias_set, base1_alias_set, |
a42ce2cc | 1238 | offset1, max_size1, |
0d2f7431 | 1239 | ref2, |
ac30e3b2 | 1240 | ref2_alias_set, base2_alias_set, |
1241 | offset2, max_size2, true); | |
dd277d48 | 1242 | |
1243 | return true; | |
1244 | } | |
1245 | ||
1246 | /* Return true if two indirect references based on *PTR1 | |
077ad5ad | 1247 | and *PTR2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and |
1248 | [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. *PTR1 and *PTR2 have | |
dd277d48 | 1249 | the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1 |
1250 | in which case they are computed on-demand. REF1 and REF2 | |
1251 | if non-NULL are the complete memory reference trees. */ | |
1252 | ||
1253 | static bool | |
182cf5a9 | 1254 | indirect_refs_may_alias_p (tree ref1 ATTRIBUTE_UNUSED, tree base1, |
fe60c82c | 1255 | poly_int64 offset1, poly_int64 max_size1, |
ac30e3b2 | 1256 | alias_set_type ref1_alias_set, |
dd277d48 | 1257 | alias_set_type base1_alias_set, |
182cf5a9 | 1258 | tree ref2 ATTRIBUTE_UNUSED, tree base2, |
fe60c82c | 1259 | poly_int64 offset2, poly_int64 max_size2, |
ac30e3b2 | 1260 | alias_set_type ref2_alias_set, |
182cf5a9 | 1261 | alias_set_type base2_alias_set, bool tbaa_p) |
dd277d48 | 1262 | { |
9a14ba4f | 1263 | tree ptr1; |
1264 | tree ptr2; | |
182cf5a9 | 1265 | tree ptrtype1, ptrtype2; |
1266 | ||
2622064f | 1267 | gcc_checking_assert ((TREE_CODE (base1) == MEM_REF |
1268 | || TREE_CODE (base1) == TARGET_MEM_REF) | |
1269 | && (TREE_CODE (base2) == MEM_REF | |
1270 | || TREE_CODE (base2) == TARGET_MEM_REF)); | |
1271 | ||
28daba6f | 1272 | ptr1 = TREE_OPERAND (base1, 0); |
1273 | ptr2 = TREE_OPERAND (base2, 0); | |
9a14ba4f | 1274 | |
dd277d48 | 1275 | /* If both bases are based on pointers they cannot alias if they may not |
1276 | point to the same memory object or if they point to the same object | |
1277 | and the accesses do not overlap. */ | |
b5c3c805 | 1278 | if ((!cfun || gimple_in_ssa_p (cfun)) |
9a14ba4f | 1279 | && operand_equal_p (ptr1, ptr2, 0) |
1280 | && (((TREE_CODE (base1) != TARGET_MEM_REF | |
88be3999 | 1281 | || (!TMR_INDEX (base1) && !TMR_INDEX2 (base1))) |
9a14ba4f | 1282 | && (TREE_CODE (base2) != TARGET_MEM_REF |
88be3999 | 1283 | || (!TMR_INDEX (base2) && !TMR_INDEX2 (base2)))) |
9a14ba4f | 1284 | || (TREE_CODE (base1) == TARGET_MEM_REF |
1285 | && TREE_CODE (base2) == TARGET_MEM_REF | |
1286 | && (TMR_STEP (base1) == TMR_STEP (base2) | |
1287 | || (TMR_STEP (base1) && TMR_STEP (base2) | |
1288 | && operand_equal_p (TMR_STEP (base1), | |
1289 | TMR_STEP (base2), 0))) | |
88be3999 | 1290 | && (TMR_INDEX (base1) == TMR_INDEX (base2) |
1291 | || (TMR_INDEX (base1) && TMR_INDEX (base2) | |
1292 | && operand_equal_p (TMR_INDEX (base1), | |
1293 | TMR_INDEX (base2), 0))) | |
1294 | && (TMR_INDEX2 (base1) == TMR_INDEX2 (base2) | |
1295 | || (TMR_INDEX2 (base1) && TMR_INDEX2 (base2) | |
1296 | && operand_equal_p (TMR_INDEX2 (base1), | |
1297 | TMR_INDEX2 (base2), 0)))))) | |
182cf5a9 | 1298 | { |
90ca1268 | 1299 | poly_offset_int moff1 = mem_ref_offset (base1) << LOG2_BITS_PER_UNIT; |
1300 | poly_offset_int moff2 = mem_ref_offset (base2) << LOG2_BITS_PER_UNIT; | |
ecc647e7 | 1301 | return ranges_maybe_overlap_p (offset1 + moff1, max_size1, |
1302 | offset2 + moff2, max_size2); | |
182cf5a9 | 1303 | } |
dd277d48 | 1304 | if (!ptr_derefs_may_alias_p (ptr1, ptr2)) |
1305 | return false; | |
1306 | ||
1307 | /* Disambiguations that rely on strict aliasing rules follow. */ | |
182cf5a9 | 1308 | if (!flag_strict_aliasing || !tbaa_p) |
dd277d48 | 1309 | return true; |
1310 | ||
2622064f | 1311 | ptrtype1 = TREE_TYPE (TREE_OPERAND (base1, 1)); |
1312 | ptrtype2 = TREE_TYPE (TREE_OPERAND (base2, 1)); | |
182cf5a9 | 1313 | |
dd277d48 | 1314 | /* If the alias set for a pointer access is zero all bets are off. */ |
f72a5e61 | 1315 | if (base1_alias_set == 0 |
1316 | || base2_alias_set == 0) | |
dd277d48 | 1317 | return true; |
1318 | ||
1319 | /* If both references are through the same type, they do not alias | |
1320 | if the accesses do not overlap. This does extra disambiguation | |
1321 | for mixed/pointer accesses but requires strict aliasing. */ | |
9c455d1e | 1322 | if ((TREE_CODE (base1) != TARGET_MEM_REF |
1323 | || (!TMR_INDEX (base1) && !TMR_INDEX2 (base1))) | |
1324 | && (TREE_CODE (base2) != TARGET_MEM_REF | |
1325 | || (!TMR_INDEX (base2) && !TMR_INDEX2 (base2))) | |
1326 | && same_type_for_tbaa (TREE_TYPE (base1), TREE_TYPE (ptrtype1)) == 1 | |
1327 | && same_type_for_tbaa (TREE_TYPE (base2), TREE_TYPE (ptrtype2)) == 1 | |
182cf5a9 | 1328 | && same_type_for_tbaa (TREE_TYPE (ptrtype1), |
873271fd | 1329 | TREE_TYPE (ptrtype2)) == 1 |
1330 | /* But avoid treating arrays as "objects", instead assume they | |
1331 | can overlap by an exact multiple of their element size. */ | |
1332 | && TREE_CODE (TREE_TYPE (ptrtype1)) != ARRAY_TYPE) | |
fe60c82c | 1333 | return ranges_maybe_overlap_p (offset1, max_size1, offset2, max_size2); |
dd277d48 | 1334 | |
1335 | /* Do type-based disambiguation. */ | |
1336 | if (base1_alias_set != base2_alias_set | |
1337 | && !alias_sets_conflict_p (base1_alias_set, base2_alias_set)) | |
1338 | return false; | |
1339 | ||
f270d2a0 | 1340 | /* If either reference is view-converted, give up now. */ |
1341 | if (same_type_for_tbaa (TREE_TYPE (base1), TREE_TYPE (ptrtype1)) != 1 | |
1342 | || same_type_for_tbaa (TREE_TYPE (base2), TREE_TYPE (ptrtype2)) != 1) | |
1343 | return true; | |
1344 | ||
1345 | if (ref1 && ref2 | |
1346 | && nonoverlapping_component_refs_p (ref1, ref2)) | |
1347 | return false; | |
1348 | ||
dd277d48 | 1349 | /* Do access-path based disambiguation. */ |
1350 | if (ref1 && ref2 | |
f270d2a0 | 1351 | && (handled_component_p (ref1) || handled_component_p (ref2))) |
0d2f7431 | 1352 | return aliasing_component_refs_p (ref1, |
ac30e3b2 | 1353 | ref1_alias_set, base1_alias_set, |
a42ce2cc | 1354 | offset1, max_size1, |
0d2f7431 | 1355 | ref2, |
ac30e3b2 | 1356 | ref2_alias_set, base2_alias_set, |
1357 | offset2, max_size2, false); | |
dd277d48 | 1358 | |
1359 | return true; | |
1360 | } | |
1361 | ||
1362 | /* Return true, if the two memory references REF1 and REF2 may alias. */ | |
1363 | ||
3a443843 | 1364 | bool |
3918bd18 | 1365 | refs_may_alias_p_1 (ao_ref *ref1, ao_ref *ref2, bool tbaa_p) |
dd277d48 | 1366 | { |
1367 | tree base1, base2; | |
fe60c82c | 1368 | poly_int64 offset1 = 0, offset2 = 0; |
1369 | poly_int64 max_size1 = -1, max_size2 = -1; | |
dd277d48 | 1370 | bool var1_p, var2_p, ind1_p, ind2_p; |
1371 | ||
c78d5cec | 1372 | gcc_checking_assert ((!ref1->ref |
8e7c2b9c | 1373 | || TREE_CODE (ref1->ref) == SSA_NAME |
c78d5cec | 1374 | || DECL_P (ref1->ref) |
2760c0e3 | 1375 | || TREE_CODE (ref1->ref) == STRING_CST |
c78d5cec | 1376 | || handled_component_p (ref1->ref) |
182cf5a9 | 1377 | || TREE_CODE (ref1->ref) == MEM_REF |
c78d5cec | 1378 | || TREE_CODE (ref1->ref) == TARGET_MEM_REF) |
1379 | && (!ref2->ref | |
8e7c2b9c | 1380 | || TREE_CODE (ref2->ref) == SSA_NAME |
c78d5cec | 1381 | || DECL_P (ref2->ref) |
2760c0e3 | 1382 | || TREE_CODE (ref2->ref) == STRING_CST |
c78d5cec | 1383 | || handled_component_p (ref2->ref) |
182cf5a9 | 1384 | || TREE_CODE (ref2->ref) == MEM_REF |
c78d5cec | 1385 | || TREE_CODE (ref2->ref) == TARGET_MEM_REF)); |
dd277d48 | 1386 | |
dd277d48 | 1387 | /* Decompose the references into their base objects and the access. */ |
3918bd18 | 1388 | base1 = ao_ref_base (ref1); |
1389 | offset1 = ref1->offset; | |
3918bd18 | 1390 | max_size1 = ref1->max_size; |
1391 | base2 = ao_ref_base (ref2); | |
1392 | offset2 = ref2->offset; | |
3918bd18 | 1393 | max_size2 = ref2->max_size; |
dd277d48 | 1394 | |
1395 | /* We can end up with registers or constants as bases for example from | |
1396 | *D.1663_44 = VIEW_CONVERT_EXPR<struct DB_LSN>(__tmp$B0F64_59); | |
1397 | which is seen as a struct copy. */ | |
1398 | if (TREE_CODE (base1) == SSA_NAME | |
119147d1 | 1399 | || TREE_CODE (base1) == CONST_DECL |
66b86a74 | 1400 | || TREE_CODE (base1) == CONSTRUCTOR |
1401 | || TREE_CODE (base1) == ADDR_EXPR | |
1402 | || CONSTANT_CLASS_P (base1) | |
1403 | || TREE_CODE (base2) == SSA_NAME | |
119147d1 | 1404 | || TREE_CODE (base2) == CONST_DECL |
66b86a74 | 1405 | || TREE_CODE (base2) == CONSTRUCTOR |
1406 | || TREE_CODE (base2) == ADDR_EXPR | |
1407 | || CONSTANT_CLASS_P (base2)) | |
dd277d48 | 1408 | return false; |
1409 | ||
04ec15fa | 1410 | /* We can end up referring to code via function and label decls. |
c78d5cec | 1411 | As we likely do not properly track code aliases conservatively |
1412 | bail out. */ | |
ceefbccc | 1413 | if (TREE_CODE (base1) == FUNCTION_DECL |
c78d5cec | 1414 | || TREE_CODE (base1) == LABEL_DECL |
66b86a74 | 1415 | || TREE_CODE (base2) == FUNCTION_DECL |
c78d5cec | 1416 | || TREE_CODE (base2) == LABEL_DECL) |
ceefbccc | 1417 | return true; |
1418 | ||
3787db52 | 1419 | /* Two volatile accesses always conflict. */ |
1420 | if (ref1->volatile_p | |
1421 | && ref2->volatile_p) | |
1422 | return true; | |
1423 | ||
090a8c65 | 1424 | /* Defer to simple offset based disambiguation if we have |
1425 | references based on two decls. Do this before defering to | |
1426 | TBAA to handle must-alias cases in conformance with the | |
1427 | GCC extension of allowing type-punning through unions. */ | |
2622064f | 1428 | var1_p = DECL_P (base1); |
1429 | var2_p = DECL_P (base2); | |
dd277d48 | 1430 | if (var1_p && var2_p) |
740a2cb6 | 1431 | return decl_refs_may_alias_p (ref1->ref, base1, offset1, max_size1, |
1432 | ref2->ref, base2, offset2, max_size2); | |
090a8c65 | 1433 | |
62b0a610 | 1434 | /* Handle restrict based accesses. |
1435 | ??? ao_ref_base strips inner MEM_REF [&decl], recover from that | |
1436 | here. */ | |
1437 | tree rbase1 = base1; | |
1438 | tree rbase2 = base2; | |
1439 | if (var1_p) | |
1440 | { | |
1441 | rbase1 = ref1->ref; | |
1442 | if (rbase1) | |
1443 | while (handled_component_p (rbase1)) | |
1444 | rbase1 = TREE_OPERAND (rbase1, 0); | |
1445 | } | |
1446 | if (var2_p) | |
1447 | { | |
1448 | rbase2 = ref2->ref; | |
1449 | if (rbase2) | |
1450 | while (handled_component_p (rbase2)) | |
1451 | rbase2 = TREE_OPERAND (rbase2, 0); | |
1452 | } | |
1453 | if (rbase1 && rbase2 | |
1454 | && (TREE_CODE (base1) == MEM_REF || TREE_CODE (base1) == TARGET_MEM_REF) | |
1455 | && (TREE_CODE (base2) == MEM_REF || TREE_CODE (base2) == TARGET_MEM_REF) | |
1456 | /* If the accesses are in the same restrict clique... */ | |
1457 | && MR_DEPENDENCE_CLIQUE (base1) == MR_DEPENDENCE_CLIQUE (base2) | |
1458 | /* But based on different pointers they do not alias. */ | |
1459 | && MR_DEPENDENCE_BASE (base1) != MR_DEPENDENCE_BASE (base2)) | |
1460 | return false; | |
1461 | ||
2622064f | 1462 | ind1_p = (TREE_CODE (base1) == MEM_REF |
1463 | || TREE_CODE (base1) == TARGET_MEM_REF); | |
1464 | ind2_p = (TREE_CODE (base2) == MEM_REF | |
1465 | || TREE_CODE (base2) == TARGET_MEM_REF); | |
182cf5a9 | 1466 | |
67817f0f | 1467 | /* Canonicalize the pointer-vs-decl case. */ |
1468 | if (ind1_p && var2_p) | |
1469 | { | |
a4f59596 | 1470 | std::swap (offset1, offset2); |
1471 | std::swap (max_size1, max_size2); | |
1472 | std::swap (base1, base2); | |
1473 | std::swap (ref1, ref2); | |
67817f0f | 1474 | var1_p = true; |
1475 | ind1_p = false; | |
1476 | var2_p = false; | |
1477 | ind2_p = true; | |
1478 | } | |
1479 | ||
090a8c65 | 1480 | /* First defer to TBAA if possible. */ |
2a3ebafa | 1481 | if (tbaa_p |
1482 | && flag_strict_aliasing | |
3918bd18 | 1483 | && !alias_sets_conflict_p (ao_ref_alias_set (ref1), |
1484 | ao_ref_alias_set (ref2))) | |
090a8c65 | 1485 | return false; |
1486 | ||
5477dab8 | 1487 | /* If the reference is based on a pointer that points to memory |
1488 | that may not be written to then the other reference cannot possibly | |
1489 | clobber it. */ | |
1490 | if ((TREE_CODE (TREE_OPERAND (base2, 0)) == SSA_NAME | |
1491 | && SSA_NAME_POINTS_TO_READONLY_MEMORY (TREE_OPERAND (base2, 0))) | |
1492 | || (ind1_p | |
1493 | && TREE_CODE (TREE_OPERAND (base1, 0)) == SSA_NAME | |
1494 | && SSA_NAME_POINTS_TO_READONLY_MEMORY (TREE_OPERAND (base1, 0)))) | |
1495 | return false; | |
1496 | ||
090a8c65 | 1497 | /* Dispatch to the pointer-vs-decl or pointer-vs-pointer disambiguators. */ |
090a8c65 | 1498 | if (var1_p && ind2_p) |
182cf5a9 | 1499 | return indirect_ref_may_alias_decl_p (ref2->ref, base2, |
ac30e3b2 | 1500 | offset2, max_size2, |
f72a5e61 | 1501 | ao_ref_alias_set (ref2), |
1502 | ao_ref_base_alias_set (ref2), | |
3918bd18 | 1503 | ref1->ref, base1, |
ac30e3b2 | 1504 | offset1, max_size1, |
182cf5a9 | 1505 | ao_ref_alias_set (ref1), |
1506 | ao_ref_base_alias_set (ref1), | |
1507 | tbaa_p); | |
dd277d48 | 1508 | else if (ind1_p && ind2_p) |
182cf5a9 | 1509 | return indirect_refs_may_alias_p (ref1->ref, base1, |
ac30e3b2 | 1510 | offset1, max_size1, |
f72a5e61 | 1511 | ao_ref_alias_set (ref1), |
1512 | ao_ref_base_alias_set (ref1), | |
182cf5a9 | 1513 | ref2->ref, base2, |
ac30e3b2 | 1514 | offset2, max_size2, |
f72a5e61 | 1515 | ao_ref_alias_set (ref2), |
1516 | ao_ref_base_alias_set (ref2), | |
182cf5a9 | 1517 | tbaa_p); |
dd277d48 | 1518 | |
1519 | gcc_unreachable (); | |
1520 | } | |
1521 | ||
258bd648 | 1522 | static bool |
58cfef6b | 1523 | refs_may_alias_p (tree ref1, ao_ref *ref2, bool tbaa_p) |
258bd648 | 1524 | { |
1525 | ao_ref r1; | |
1526 | ao_ref_init (&r1, ref1); | |
58cfef6b | 1527 | return refs_may_alias_p_1 (&r1, ref2, tbaa_p); |
258bd648 | 1528 | } |
1529 | ||
dd277d48 | 1530 | bool |
58cfef6b | 1531 | refs_may_alias_p (tree ref1, tree ref2, bool tbaa_p) |
dd277d48 | 1532 | { |
3918bd18 | 1533 | ao_ref r1, r2; |
1534 | bool res; | |
1535 | ao_ref_init (&r1, ref1); | |
1536 | ao_ref_init (&r2, ref2); | |
58cfef6b | 1537 | res = refs_may_alias_p_1 (&r1, &r2, tbaa_p); |
dd277d48 | 1538 | if (res) |
1539 | ++alias_stats.refs_may_alias_p_may_alias; | |
1540 | else | |
1541 | ++alias_stats.refs_may_alias_p_no_alias; | |
1542 | return res; | |
1543 | } | |
1544 | ||
2a3ebafa | 1545 | /* Returns true if there is a anti-dependence for the STORE that |
1546 | executes after the LOAD. */ | |
1547 | ||
1548 | bool | |
1549 | refs_anti_dependent_p (tree load, tree store) | |
1550 | { | |
3918bd18 | 1551 | ao_ref r1, r2; |
1552 | ao_ref_init (&r1, load); | |
1553 | ao_ref_init (&r2, store); | |
1554 | return refs_may_alias_p_1 (&r1, &r2, false); | |
2a3ebafa | 1555 | } |
1556 | ||
1557 | /* Returns true if there is a output dependence for the stores | |
1558 | STORE1 and STORE2. */ | |
1559 | ||
1560 | bool | |
1561 | refs_output_dependent_p (tree store1, tree store2) | |
1562 | { | |
3918bd18 | 1563 | ao_ref r1, r2; |
1564 | ao_ref_init (&r1, store1); | |
1565 | ao_ref_init (&r2, store2); | |
1566 | return refs_may_alias_p_1 (&r1, &r2, false); | |
2a3ebafa | 1567 | } |
dd277d48 | 1568 | |
1569 | /* If the call CALL may use the memory reference REF return true, | |
1570 | otherwise return false. */ | |
1571 | ||
1572 | static bool | |
58cfef6b | 1573 | ref_maybe_used_by_call_p_1 (gcall *call, ao_ref *ref, bool tbaa_p) |
dd277d48 | 1574 | { |
047fdd47 | 1575 | tree base, callee; |
dd277d48 | 1576 | unsigned i; |
1577 | int flags = gimple_call_flags (call); | |
1578 | ||
1579 | /* Const functions without a static chain do not implicitly use memory. */ | |
1580 | if (!gimple_call_chain (call) | |
1581 | && (flags & (ECF_CONST|ECF_NOVOPS))) | |
1582 | goto process_args; | |
1583 | ||
134899ac | 1584 | base = ao_ref_base (ref); |
917f08fa | 1585 | if (!base) |
dd277d48 | 1586 | return true; |
1587 | ||
3787db52 | 1588 | /* A call that is not without side-effects might involve volatile |
1589 | accesses and thus conflicts with all other volatile accesses. */ | |
1590 | if (ref->volatile_p) | |
1591 | return true; | |
1592 | ||
09347e88 | 1593 | /* If the reference is based on a decl that is not aliased the call |
1594 | cannot possibly use it. */ | |
1595 | if (DECL_P (base) | |
1596 | && !may_be_aliased (base) | |
7f7f16d4 | 1597 | /* But local statics can be used through recursion. */ |
1598 | && !is_global_var (base)) | |
09347e88 | 1599 | goto process_args; |
1600 | ||
047fdd47 | 1601 | callee = gimple_call_fndecl (call); |
1602 | ||
1603 | /* Handle those builtin functions explicitly that do not act as | |
1604 | escape points. See tree-ssa-structalias.c:find_func_aliases | |
1605 | for the list of builtins we might need to handle here. */ | |
1606 | if (callee != NULL_TREE | |
6189000c | 1607 | && gimple_call_builtin_p (call, BUILT_IN_NORMAL)) |
047fdd47 | 1608 | switch (DECL_FUNCTION_CODE (callee)) |
1609 | { | |
77efe819 | 1610 | /* All the following functions read memory pointed to by |
1611 | their second argument. strcat/strncat additionally | |
1612 | reads memory pointed to by the first argument. */ | |
1613 | case BUILT_IN_STRCAT: | |
1614 | case BUILT_IN_STRNCAT: | |
1615 | { | |
1616 | ao_ref dref; | |
1617 | ao_ref_init_from_ptr_and_size (&dref, | |
1618 | gimple_call_arg (call, 0), | |
1619 | NULL_TREE); | |
1620 | if (refs_may_alias_p_1 (&dref, ref, false)) | |
1621 | return true; | |
1622 | } | |
1623 | /* FALLTHRU */ | |
047fdd47 | 1624 | case BUILT_IN_STRCPY: |
1625 | case BUILT_IN_STRNCPY: | |
047fdd47 | 1626 | case BUILT_IN_MEMCPY: |
1627 | case BUILT_IN_MEMMOVE: | |
1628 | case BUILT_IN_MEMPCPY: | |
1629 | case BUILT_IN_STPCPY: | |
1630 | case BUILT_IN_STPNCPY: | |
4c0315d0 | 1631 | case BUILT_IN_TM_MEMCPY: |
1632 | case BUILT_IN_TM_MEMMOVE: | |
047fdd47 | 1633 | { |
134899ac | 1634 | ao_ref dref; |
1635 | tree size = NULL_TREE; | |
1636 | if (gimple_call_num_args (call) == 3) | |
1637 | size = gimple_call_arg (call, 2); | |
1638 | ao_ref_init_from_ptr_and_size (&dref, | |
1639 | gimple_call_arg (call, 1), | |
1640 | size); | |
1641 | return refs_may_alias_p_1 (&dref, ref, false); | |
047fdd47 | 1642 | } |
77efe819 | 1643 | case BUILT_IN_STRCAT_CHK: |
1644 | case BUILT_IN_STRNCAT_CHK: | |
1645 | { | |
1646 | ao_ref dref; | |
1647 | ao_ref_init_from_ptr_and_size (&dref, | |
1648 | gimple_call_arg (call, 0), | |
1649 | NULL_TREE); | |
1650 | if (refs_may_alias_p_1 (&dref, ref, false)) | |
1651 | return true; | |
1652 | } | |
1653 | /* FALLTHRU */ | |
939514e9 | 1654 | case BUILT_IN_STRCPY_CHK: |
1655 | case BUILT_IN_STRNCPY_CHK: | |
1656 | case BUILT_IN_MEMCPY_CHK: | |
1657 | case BUILT_IN_MEMMOVE_CHK: | |
1658 | case BUILT_IN_MEMPCPY_CHK: | |
1659 | case BUILT_IN_STPCPY_CHK: | |
1063acde | 1660 | case BUILT_IN_STPNCPY_CHK: |
939514e9 | 1661 | { |
1662 | ao_ref dref; | |
1663 | tree size = NULL_TREE; | |
1664 | if (gimple_call_num_args (call) == 4) | |
1665 | size = gimple_call_arg (call, 2); | |
1666 | ao_ref_init_from_ptr_and_size (&dref, | |
1667 | gimple_call_arg (call, 1), | |
1668 | size); | |
1669 | return refs_may_alias_p_1 (&dref, ref, false); | |
1670 | } | |
119147d1 | 1671 | case BUILT_IN_BCOPY: |
1672 | { | |
1673 | ao_ref dref; | |
1674 | tree size = gimple_call_arg (call, 2); | |
1675 | ao_ref_init_from_ptr_and_size (&dref, | |
1676 | gimple_call_arg (call, 0), | |
1677 | size); | |
1678 | return refs_may_alias_p_1 (&dref, ref, false); | |
1679 | } | |
4c0315d0 | 1680 | |
1681 | /* The following functions read memory pointed to by their | |
1682 | first argument. */ | |
1683 | CASE_BUILT_IN_TM_LOAD (1): | |
1684 | CASE_BUILT_IN_TM_LOAD (2): | |
1685 | CASE_BUILT_IN_TM_LOAD (4): | |
1686 | CASE_BUILT_IN_TM_LOAD (8): | |
1687 | CASE_BUILT_IN_TM_LOAD (FLOAT): | |
1688 | CASE_BUILT_IN_TM_LOAD (DOUBLE): | |
1689 | CASE_BUILT_IN_TM_LOAD (LDOUBLE): | |
1690 | CASE_BUILT_IN_TM_LOAD (M64): | |
1691 | CASE_BUILT_IN_TM_LOAD (M128): | |
1692 | CASE_BUILT_IN_TM_LOAD (M256): | |
1693 | case BUILT_IN_TM_LOG: | |
1694 | case BUILT_IN_TM_LOG_1: | |
1695 | case BUILT_IN_TM_LOG_2: | |
1696 | case BUILT_IN_TM_LOG_4: | |
1697 | case BUILT_IN_TM_LOG_8: | |
1698 | case BUILT_IN_TM_LOG_FLOAT: | |
1699 | case BUILT_IN_TM_LOG_DOUBLE: | |
1700 | case BUILT_IN_TM_LOG_LDOUBLE: | |
1701 | case BUILT_IN_TM_LOG_M64: | |
1702 | case BUILT_IN_TM_LOG_M128: | |
1703 | case BUILT_IN_TM_LOG_M256: | |
1704 | return ptr_deref_may_alias_ref_p_1 (gimple_call_arg (call, 0), ref); | |
1705 | ||
77efe819 | 1706 | /* These read memory pointed to by the first argument. */ |
1707 | case BUILT_IN_STRDUP: | |
1708 | case BUILT_IN_STRNDUP: | |
ee890734 | 1709 | case BUILT_IN_REALLOC: |
77efe819 | 1710 | { |
1711 | ao_ref dref; | |
1712 | tree size = NULL_TREE; | |
1713 | if (gimple_call_num_args (call) == 2) | |
1714 | size = gimple_call_arg (call, 1); | |
1715 | ao_ref_init_from_ptr_and_size (&dref, | |
1716 | gimple_call_arg (call, 0), | |
1717 | size); | |
1718 | return refs_may_alias_p_1 (&dref, ref, false); | |
1719 | } | |
4953672f | 1720 | /* These read memory pointed to by the first argument. */ |
1721 | case BUILT_IN_INDEX: | |
1722 | case BUILT_IN_STRCHR: | |
1723 | case BUILT_IN_STRRCHR: | |
1724 | { | |
1725 | ao_ref dref; | |
1726 | ao_ref_init_from_ptr_and_size (&dref, | |
1727 | gimple_call_arg (call, 0), | |
1728 | NULL_TREE); | |
1729 | return refs_may_alias_p_1 (&dref, ref, false); | |
1730 | } | |
1731 | /* These read memory pointed to by the first argument with size | |
1732 | in the third argument. */ | |
1733 | case BUILT_IN_MEMCHR: | |
1734 | { | |
1735 | ao_ref dref; | |
1736 | ao_ref_init_from_ptr_and_size (&dref, | |
1737 | gimple_call_arg (call, 0), | |
1738 | gimple_call_arg (call, 2)); | |
1739 | return refs_may_alias_p_1 (&dref, ref, false); | |
1740 | } | |
1741 | /* These read memory pointed to by the first and second arguments. */ | |
1742 | case BUILT_IN_STRSTR: | |
1743 | case BUILT_IN_STRPBRK: | |
1744 | { | |
1745 | ao_ref dref; | |
1746 | ao_ref_init_from_ptr_and_size (&dref, | |
1747 | gimple_call_arg (call, 0), | |
1748 | NULL_TREE); | |
1749 | if (refs_may_alias_p_1 (&dref, ref, false)) | |
1750 | return true; | |
1751 | ao_ref_init_from_ptr_and_size (&dref, | |
1752 | gimple_call_arg (call, 1), | |
1753 | NULL_TREE); | |
1754 | return refs_may_alias_p_1 (&dref, ref, false); | |
1755 | } | |
1756 | ||
09d9c774 | 1757 | /* The following builtins do not read from memory. */ |
1758 | case BUILT_IN_FREE: | |
0d3ca08e | 1759 | case BUILT_IN_MALLOC: |
be2c7f8f | 1760 | case BUILT_IN_POSIX_MEMALIGN: |
060fc206 | 1761 | case BUILT_IN_ALIGNED_ALLOC: |
4ef43bbd | 1762 | case BUILT_IN_CALLOC: |
2b34677f | 1763 | CASE_BUILT_IN_ALLOCA: |
ca793672 | 1764 | case BUILT_IN_STACK_SAVE: |
1765 | case BUILT_IN_STACK_RESTORE: | |
09d9c774 | 1766 | case BUILT_IN_MEMSET: |
4c0315d0 | 1767 | case BUILT_IN_TM_MEMSET: |
939514e9 | 1768 | case BUILT_IN_MEMSET_CHK: |
09d9c774 | 1769 | case BUILT_IN_FREXP: |
1770 | case BUILT_IN_FREXPF: | |
1771 | case BUILT_IN_FREXPL: | |
1772 | case BUILT_IN_GAMMA_R: | |
1773 | case BUILT_IN_GAMMAF_R: | |
1774 | case BUILT_IN_GAMMAL_R: | |
1775 | case BUILT_IN_LGAMMA_R: | |
1776 | case BUILT_IN_LGAMMAF_R: | |
1777 | case BUILT_IN_LGAMMAL_R: | |
1778 | case BUILT_IN_MODF: | |
1779 | case BUILT_IN_MODFF: | |
1780 | case BUILT_IN_MODFL: | |
1781 | case BUILT_IN_REMQUO: | |
1782 | case BUILT_IN_REMQUOF: | |
1783 | case BUILT_IN_REMQUOL: | |
1784 | case BUILT_IN_SINCOS: | |
1785 | case BUILT_IN_SINCOSF: | |
1786 | case BUILT_IN_SINCOSL: | |
fca0886c | 1787 | case BUILT_IN_ASSUME_ALIGNED: |
9d17b4a8 | 1788 | case BUILT_IN_VA_END: |
09d9c774 | 1789 | return false; |
a44814b9 | 1790 | /* __sync_* builtins and some OpenMP builtins act as threading |
1791 | barriers. */ | |
1792 | #undef DEF_SYNC_BUILTIN | |
1793 | #define DEF_SYNC_BUILTIN(ENUM, NAME, TYPE, ATTRS) case ENUM: | |
1794 | #include "sync-builtins.def" | |
1795 | #undef DEF_SYNC_BUILTIN | |
1796 | case BUILT_IN_GOMP_ATOMIC_START: | |
1797 | case BUILT_IN_GOMP_ATOMIC_END: | |
1798 | case BUILT_IN_GOMP_BARRIER: | |
bc7bff74 | 1799 | case BUILT_IN_GOMP_BARRIER_CANCEL: |
a44814b9 | 1800 | case BUILT_IN_GOMP_TASKWAIT: |
bc7bff74 | 1801 | case BUILT_IN_GOMP_TASKGROUP_END: |
a44814b9 | 1802 | case BUILT_IN_GOMP_CRITICAL_START: |
1803 | case BUILT_IN_GOMP_CRITICAL_END: | |
1804 | case BUILT_IN_GOMP_CRITICAL_NAME_START: | |
1805 | case BUILT_IN_GOMP_CRITICAL_NAME_END: | |
1806 | case BUILT_IN_GOMP_LOOP_END: | |
bc7bff74 | 1807 | case BUILT_IN_GOMP_LOOP_END_CANCEL: |
a44814b9 | 1808 | case BUILT_IN_GOMP_ORDERED_START: |
1809 | case BUILT_IN_GOMP_ORDERED_END: | |
a44814b9 | 1810 | case BUILT_IN_GOMP_SECTIONS_END: |
bc7bff74 | 1811 | case BUILT_IN_GOMP_SECTIONS_END_CANCEL: |
a44814b9 | 1812 | case BUILT_IN_GOMP_SINGLE_COPY_START: |
1813 | case BUILT_IN_GOMP_SINGLE_COPY_END: | |
1814 | return true; | |
09d9c774 | 1815 | |
047fdd47 | 1816 | default: |
1817 | /* Fallthru to general call handling. */; | |
1818 | } | |
1819 | ||
dd277d48 | 1820 | /* Check if base is a global static variable that is not read |
1821 | by the function. */ | |
53e9c5c4 | 1822 | if (callee != NULL_TREE && VAR_P (base) && TREE_STATIC (base)) |
4ee9c684 | 1823 | { |
415d1b9a | 1824 | struct cgraph_node *node = cgraph_node::get (callee); |
b39960e1 | 1825 | bitmap not_read; |
dd277d48 | 1826 | |
924de091 | 1827 | /* FIXME: Callee can be an OMP builtin that does not have a call graph |
1828 | node yet. We should enforce that there are nodes for all decls in the | |
1829 | IL and remove this check instead. */ | |
b39960e1 | 1830 | if (node |
1831 | && (not_read = ipa_reference_get_not_read_global (node)) | |
1832 | && bitmap_bit_p (not_read, ipa_reference_var_uid (base))) | |
1833 | goto process_args; | |
4ee9c684 | 1834 | } |
1835 | ||
cb245216 | 1836 | /* Check if the base variable is call-used. */ |
1837 | if (DECL_P (base)) | |
4ee9c684 | 1838 | { |
cb245216 | 1839 | if (pt_solution_includes (gimple_call_use_set (call), base)) |
dd277d48 | 1840 | return true; |
1841 | } | |
2622064f | 1842 | else if ((TREE_CODE (base) == MEM_REF |
1843 | || TREE_CODE (base) == TARGET_MEM_REF) | |
cb245216 | 1844 | && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME) |
dd277d48 | 1845 | { |
cb245216 | 1846 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0)); |
1847 | if (!pi) | |
1848 | return true; | |
917f08fa | 1849 | |
cb245216 | 1850 | if (pt_solutions_intersect (gimple_call_use_set (call), &pi->pt)) |
dd277d48 | 1851 | return true; |
1852 | } | |
cb245216 | 1853 | else |
1854 | return true; | |
dd277d48 | 1855 | |
1856 | /* Inspect call arguments for passed-by-value aliases. */ | |
1857 | process_args: | |
1858 | for (i = 0; i < gimple_call_num_args (call); ++i) | |
1859 | { | |
1860 | tree op = gimple_call_arg (call, i); | |
8ce86007 | 1861 | int flags = gimple_call_arg_flags (call, i); |
1862 | ||
1863 | if (flags & EAF_UNUSED) | |
1864 | continue; | |
dd277d48 | 1865 | |
dd277d48 | 1866 | if (TREE_CODE (op) == WITH_SIZE_EXPR) |
1867 | op = TREE_OPERAND (op, 0); | |
4ee9c684 | 1868 | |
dd277d48 | 1869 | if (TREE_CODE (op) != SSA_NAME |
134899ac | 1870 | && !is_gimple_min_invariant (op)) |
1871 | { | |
1872 | ao_ref r; | |
1873 | ao_ref_init (&r, op); | |
58cfef6b | 1874 | if (refs_may_alias_p_1 (&r, ref, tbaa_p)) |
134899ac | 1875 | return true; |
1876 | } | |
4ee9c684 | 1877 | } |
1878 | ||
dd277d48 | 1879 | return false; |
1880 | } | |
1881 | ||
1882 | static bool | |
58cfef6b | 1883 | ref_maybe_used_by_call_p (gcall *call, ao_ref *ref, bool tbaa_p) |
dd277d48 | 1884 | { |
134899ac | 1885 | bool res; |
58cfef6b | 1886 | res = ref_maybe_used_by_call_p_1 (call, ref, tbaa_p); |
dd277d48 | 1887 | if (res) |
1888 | ++alias_stats.ref_maybe_used_by_call_p_may_alias; | |
1889 | else | |
1890 | ++alias_stats.ref_maybe_used_by_call_p_no_alias; | |
1891 | return res; | |
4ee9c684 | 1892 | } |
1893 | ||
1894 | ||
dd277d48 | 1895 | /* If the statement STMT may use the memory reference REF return |
1896 | true, otherwise return false. */ | |
4ee9c684 | 1897 | |
dd277d48 | 1898 | bool |
58cfef6b | 1899 | ref_maybe_used_by_stmt_p (gimple *stmt, ao_ref *ref, bool tbaa_p) |
4ee9c684 | 1900 | { |
dd277d48 | 1901 | if (is_gimple_assign (stmt)) |
1902 | { | |
1903 | tree rhs; | |
1904 | ||
1905 | /* All memory assign statements are single. */ | |
1906 | if (!gimple_assign_single_p (stmt)) | |
1907 | return false; | |
1908 | ||
1909 | rhs = gimple_assign_rhs1 (stmt); | |
1910 | if (is_gimple_reg (rhs) | |
1911 | || is_gimple_min_invariant (rhs) | |
1912 | || gimple_assign_rhs_code (stmt) == CONSTRUCTOR) | |
1913 | return false; | |
1914 | ||
58cfef6b | 1915 | return refs_may_alias_p (rhs, ref, tbaa_p); |
dd277d48 | 1916 | } |
1917 | else if (is_gimple_call (stmt)) | |
58cfef6b | 1918 | return ref_maybe_used_by_call_p (as_a <gcall *> (stmt), ref, tbaa_p); |
1a91d914 | 1919 | else if (greturn *return_stmt = dyn_cast <greturn *> (stmt)) |
91234829 | 1920 | { |
1a91d914 | 1921 | tree retval = gimple_return_retval (return_stmt); |
91234829 | 1922 | if (retval |
1923 | && TREE_CODE (retval) != SSA_NAME | |
1924 | && !is_gimple_min_invariant (retval) | |
58cfef6b | 1925 | && refs_may_alias_p (retval, ref, tbaa_p)) |
91234829 | 1926 | return true; |
1927 | /* If ref escapes the function then the return acts as a use. */ | |
258bd648 | 1928 | tree base = ao_ref_base (ref); |
91234829 | 1929 | if (!base) |
1930 | ; | |
1931 | else if (DECL_P (base)) | |
1932 | return is_global_var (base); | |
1933 | else if (TREE_CODE (base) == MEM_REF | |
1934 | || TREE_CODE (base) == TARGET_MEM_REF) | |
1935 | return ptr_deref_may_alias_global_p (TREE_OPERAND (base, 0)); | |
1936 | return false; | |
1937 | } | |
dd277d48 | 1938 | |
1939 | return true; | |
4ee9c684 | 1940 | } |
1941 | ||
258bd648 | 1942 | bool |
58cfef6b | 1943 | ref_maybe_used_by_stmt_p (gimple *stmt, tree ref, bool tbaa_p) |
258bd648 | 1944 | { |
1945 | ao_ref r; | |
1946 | ao_ref_init (&r, ref); | |
58cfef6b | 1947 | return ref_maybe_used_by_stmt_p (stmt, &r, tbaa_p); |
258bd648 | 1948 | } |
1949 | ||
dd277d48 | 1950 | /* If the call in statement CALL may clobber the memory reference REF |
1951 | return true, otherwise return false. */ | |
4ee9c684 | 1952 | |
38168b16 | 1953 | bool |
1a91d914 | 1954 | call_may_clobber_ref_p_1 (gcall *call, ao_ref *ref) |
4ee9c684 | 1955 | { |
7f7f16d4 | 1956 | tree base; |
047fdd47 | 1957 | tree callee; |
dd277d48 | 1958 | |
1959 | /* If the call is pure or const it cannot clobber anything. */ | |
1960 | if (gimple_call_flags (call) | |
1961 | & (ECF_PURE|ECF_CONST|ECF_LOOPING_CONST_OR_PURE|ECF_NOVOPS)) | |
1962 | return false; | |
32cf7025 | 1963 | if (gimple_call_internal_p (call)) |
1964 | switch (gimple_call_internal_fn (call)) | |
1965 | { | |
1966 | /* Treat these internal calls like ECF_PURE for aliasing, | |
1967 | they don't write to any memory the program should care about. | |
1968 | They have important other side-effects, and read memory, | |
1969 | so can't be ECF_NOVOPS. */ | |
1970 | case IFN_UBSAN_NULL: | |
1971 | case IFN_UBSAN_BOUNDS: | |
1972 | case IFN_UBSAN_VPTR: | |
1973 | case IFN_UBSAN_OBJECT_SIZE: | |
b4fce8f9 | 1974 | case IFN_UBSAN_PTR: |
32cf7025 | 1975 | case IFN_ASAN_CHECK: |
1976 | return false; | |
1977 | default: | |
1978 | break; | |
1979 | } | |
dd277d48 | 1980 | |
3918bd18 | 1981 | base = ao_ref_base (ref); |
dd277d48 | 1982 | if (!base) |
1983 | return true; | |
1984 | ||
1985 | if (TREE_CODE (base) == SSA_NAME | |
1986 | || CONSTANT_CLASS_P (base)) | |
1987 | return false; | |
1988 | ||
3787db52 | 1989 | /* A call that is not without side-effects might involve volatile |
1990 | accesses and thus conflicts with all other volatile accesses. */ | |
1991 | if (ref->volatile_p) | |
1992 | return true; | |
1993 | ||
09347e88 | 1994 | /* If the reference is based on a decl that is not aliased the call |
1995 | cannot possibly clobber it. */ | |
1996 | if (DECL_P (base) | |
1997 | && !may_be_aliased (base) | |
7f7f16d4 | 1998 | /* But local non-readonly statics can be modified through recursion |
1999 | or the call may implement a threading barrier which we must | |
2000 | treat as may-def. */ | |
09347e88 | 2001 | && (TREE_READONLY (base) |
7f7f16d4 | 2002 | || !is_global_var (base))) |
09347e88 | 2003 | return false; |
2004 | ||
5477dab8 | 2005 | /* If the reference is based on a pointer that points to memory |
2006 | that may not be written to then the call cannot possibly clobber it. */ | |
2007 | if ((TREE_CODE (base) == MEM_REF | |
2008 | || TREE_CODE (base) == TARGET_MEM_REF) | |
2009 | && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME | |
2010 | && SSA_NAME_POINTS_TO_READONLY_MEMORY (TREE_OPERAND (base, 0))) | |
2011 | return false; | |
2012 | ||
047fdd47 | 2013 | callee = gimple_call_fndecl (call); |
2014 | ||
2015 | /* Handle those builtin functions explicitly that do not act as | |
2016 | escape points. See tree-ssa-structalias.c:find_func_aliases | |
2017 | for the list of builtins we might need to handle here. */ | |
2018 | if (callee != NULL_TREE | |
6189000c | 2019 | && gimple_call_builtin_p (call, BUILT_IN_NORMAL)) |
047fdd47 | 2020 | switch (DECL_FUNCTION_CODE (callee)) |
2021 | { | |
2022 | /* All the following functions clobber memory pointed to by | |
2023 | their first argument. */ | |
2024 | case BUILT_IN_STRCPY: | |
2025 | case BUILT_IN_STRNCPY: | |
047fdd47 | 2026 | case BUILT_IN_MEMCPY: |
2027 | case BUILT_IN_MEMMOVE: | |
2028 | case BUILT_IN_MEMPCPY: | |
2029 | case BUILT_IN_STPCPY: | |
2030 | case BUILT_IN_STPNCPY: | |
2031 | case BUILT_IN_STRCAT: | |
2032 | case BUILT_IN_STRNCAT: | |
134899ac | 2033 | case BUILT_IN_MEMSET: |
4c0315d0 | 2034 | case BUILT_IN_TM_MEMSET: |
2035 | CASE_BUILT_IN_TM_STORE (1): | |
2036 | CASE_BUILT_IN_TM_STORE (2): | |
2037 | CASE_BUILT_IN_TM_STORE (4): | |
2038 | CASE_BUILT_IN_TM_STORE (8): | |
2039 | CASE_BUILT_IN_TM_STORE (FLOAT): | |
2040 | CASE_BUILT_IN_TM_STORE (DOUBLE): | |
2041 | CASE_BUILT_IN_TM_STORE (LDOUBLE): | |
2042 | CASE_BUILT_IN_TM_STORE (M64): | |
2043 | CASE_BUILT_IN_TM_STORE (M128): | |
2044 | CASE_BUILT_IN_TM_STORE (M256): | |
2045 | case BUILT_IN_TM_MEMCPY: | |
2046 | case BUILT_IN_TM_MEMMOVE: | |
047fdd47 | 2047 | { |
134899ac | 2048 | ao_ref dref; |
2049 | tree size = NULL_TREE; | |
77efe819 | 2050 | /* Don't pass in size for strncat, as the maximum size |
2051 | is strlen (dest) + n + 1 instead of n, resp. | |
2052 | n + 1 at dest + strlen (dest), but strlen (dest) isn't | |
2053 | known. */ | |
2054 | if (gimple_call_num_args (call) == 3 | |
2055 | && DECL_FUNCTION_CODE (callee) != BUILT_IN_STRNCAT) | |
134899ac | 2056 | size = gimple_call_arg (call, 2); |
2057 | ao_ref_init_from_ptr_and_size (&dref, | |
2058 | gimple_call_arg (call, 0), | |
2059 | size); | |
2060 | return refs_may_alias_p_1 (&dref, ref, false); | |
047fdd47 | 2061 | } |
939514e9 | 2062 | case BUILT_IN_STRCPY_CHK: |
2063 | case BUILT_IN_STRNCPY_CHK: | |
2064 | case BUILT_IN_MEMCPY_CHK: | |
2065 | case BUILT_IN_MEMMOVE_CHK: | |
2066 | case BUILT_IN_MEMPCPY_CHK: | |
2067 | case BUILT_IN_STPCPY_CHK: | |
1063acde | 2068 | case BUILT_IN_STPNCPY_CHK: |
939514e9 | 2069 | case BUILT_IN_STRCAT_CHK: |
2070 | case BUILT_IN_STRNCAT_CHK: | |
2071 | case BUILT_IN_MEMSET_CHK: | |
2072 | { | |
2073 | ao_ref dref; | |
2074 | tree size = NULL_TREE; | |
77efe819 | 2075 | /* Don't pass in size for __strncat_chk, as the maximum size |
2076 | is strlen (dest) + n + 1 instead of n, resp. | |
2077 | n + 1 at dest + strlen (dest), but strlen (dest) isn't | |
2078 | known. */ | |
2079 | if (gimple_call_num_args (call) == 4 | |
2080 | && DECL_FUNCTION_CODE (callee) != BUILT_IN_STRNCAT_CHK) | |
939514e9 | 2081 | size = gimple_call_arg (call, 2); |
2082 | ao_ref_init_from_ptr_and_size (&dref, | |
2083 | gimple_call_arg (call, 0), | |
2084 | size); | |
2085 | return refs_may_alias_p_1 (&dref, ref, false); | |
2086 | } | |
119147d1 | 2087 | case BUILT_IN_BCOPY: |
2088 | { | |
2089 | ao_ref dref; | |
2090 | tree size = gimple_call_arg (call, 2); | |
2091 | ao_ref_init_from_ptr_and_size (&dref, | |
2092 | gimple_call_arg (call, 1), | |
2093 | size); | |
2094 | return refs_may_alias_p_1 (&dref, ref, false); | |
2095 | } | |
0d3ca08e | 2096 | /* Allocating memory does not have any side-effects apart from |
2097 | being the definition point for the pointer. */ | |
2098 | case BUILT_IN_MALLOC: | |
060fc206 | 2099 | case BUILT_IN_ALIGNED_ALLOC: |
4ef43bbd | 2100 | case BUILT_IN_CALLOC: |
77efe819 | 2101 | case BUILT_IN_STRDUP: |
2102 | case BUILT_IN_STRNDUP: | |
be97d4b6 | 2103 | /* Unix98 specifies that errno is set on allocation failure. */ |
a29c5f9c | 2104 | if (flag_errno_math |
be97d4b6 | 2105 | && targetm.ref_may_alias_errno (ref)) |
2106 | return true; | |
0d3ca08e | 2107 | return false; |
ca793672 | 2108 | case BUILT_IN_STACK_SAVE: |
2b34677f | 2109 | CASE_BUILT_IN_ALLOCA: |
fca0886c | 2110 | case BUILT_IN_ASSUME_ALIGNED: |
ca793672 | 2111 | return false; |
be2c7f8f | 2112 | /* But posix_memalign stores a pointer into the memory pointed to |
2113 | by its first argument. */ | |
2114 | case BUILT_IN_POSIX_MEMALIGN: | |
2115 | { | |
2116 | tree ptrptr = gimple_call_arg (call, 0); | |
2117 | ao_ref dref; | |
2118 | ao_ref_init_from_ptr_and_size (&dref, ptrptr, | |
2119 | TYPE_SIZE_UNIT (ptr_type_node)); | |
2120 | return (refs_may_alias_p_1 (&dref, ref, false) | |
2121 | || (flag_errno_math | |
2122 | && targetm.ref_may_alias_errno (ref))); | |
2123 | } | |
047fdd47 | 2124 | /* Freeing memory kills the pointed-to memory. More importantly |
2125 | the call has to serve as a barrier for moving loads and stores | |
134899ac | 2126 | across it. */ |
047fdd47 | 2127 | case BUILT_IN_FREE: |
9d17b4a8 | 2128 | case BUILT_IN_VA_END: |
047fdd47 | 2129 | { |
2130 | tree ptr = gimple_call_arg (call, 0); | |
2131 | return ptr_deref_may_alias_ref_p_1 (ptr, ref); | |
2132 | } | |
ee890734 | 2133 | /* Realloc serves both as allocation point and deallocation point. */ |
2134 | case BUILT_IN_REALLOC: | |
2135 | { | |
2136 | tree ptr = gimple_call_arg (call, 0); | |
2137 | /* Unix98 specifies that errno is set on allocation failure. */ | |
2138 | return ((flag_errno_math | |
2139 | && targetm.ref_may_alias_errno (ref)) | |
2140 | || ptr_deref_may_alias_ref_p_1 (ptr, ref)); | |
2141 | } | |
047fdd47 | 2142 | case BUILT_IN_GAMMA_R: |
2143 | case BUILT_IN_GAMMAF_R: | |
2144 | case BUILT_IN_GAMMAL_R: | |
2145 | case BUILT_IN_LGAMMA_R: | |
2146 | case BUILT_IN_LGAMMAF_R: | |
2147 | case BUILT_IN_LGAMMAL_R: | |
09d9c774 | 2148 | { |
2149 | tree out = gimple_call_arg (call, 1); | |
2150 | if (ptr_deref_may_alias_ref_p_1 (out, ref)) | |
2151 | return true; | |
2152 | if (flag_errno_math) | |
2153 | break; | |
2154 | return false; | |
2155 | } | |
2156 | case BUILT_IN_FREXP: | |
2157 | case BUILT_IN_FREXPF: | |
2158 | case BUILT_IN_FREXPL: | |
047fdd47 | 2159 | case BUILT_IN_MODF: |
2160 | case BUILT_IN_MODFF: | |
2161 | case BUILT_IN_MODFL: | |
2162 | { | |
2163 | tree out = gimple_call_arg (call, 1); | |
2164 | return ptr_deref_may_alias_ref_p_1 (out, ref); | |
2165 | } | |
2166 | case BUILT_IN_REMQUO: | |
2167 | case BUILT_IN_REMQUOF: | |
2168 | case BUILT_IN_REMQUOL: | |
2169 | { | |
2170 | tree out = gimple_call_arg (call, 2); | |
09d9c774 | 2171 | if (ptr_deref_may_alias_ref_p_1 (out, ref)) |
2172 | return true; | |
2173 | if (flag_errno_math) | |
2174 | break; | |
2175 | return false; | |
047fdd47 | 2176 | } |
2177 | case BUILT_IN_SINCOS: | |
2178 | case BUILT_IN_SINCOSF: | |
2179 | case BUILT_IN_SINCOSL: | |
2180 | { | |
2181 | tree sin = gimple_call_arg (call, 1); | |
2182 | tree cos = gimple_call_arg (call, 2); | |
2183 | return (ptr_deref_may_alias_ref_p_1 (sin, ref) | |
2184 | || ptr_deref_may_alias_ref_p_1 (cos, ref)); | |
2185 | } | |
a44814b9 | 2186 | /* __sync_* builtins and some OpenMP builtins act as threading |
2187 | barriers. */ | |
2188 | #undef DEF_SYNC_BUILTIN | |
2189 | #define DEF_SYNC_BUILTIN(ENUM, NAME, TYPE, ATTRS) case ENUM: | |
2190 | #include "sync-builtins.def" | |
2191 | #undef DEF_SYNC_BUILTIN | |
2192 | case BUILT_IN_GOMP_ATOMIC_START: | |
2193 | case BUILT_IN_GOMP_ATOMIC_END: | |
2194 | case BUILT_IN_GOMP_BARRIER: | |
bc7bff74 | 2195 | case BUILT_IN_GOMP_BARRIER_CANCEL: |
a44814b9 | 2196 | case BUILT_IN_GOMP_TASKWAIT: |
bc7bff74 | 2197 | case BUILT_IN_GOMP_TASKGROUP_END: |
a44814b9 | 2198 | case BUILT_IN_GOMP_CRITICAL_START: |
2199 | case BUILT_IN_GOMP_CRITICAL_END: | |
2200 | case BUILT_IN_GOMP_CRITICAL_NAME_START: | |
2201 | case BUILT_IN_GOMP_CRITICAL_NAME_END: | |
2202 | case BUILT_IN_GOMP_LOOP_END: | |
bc7bff74 | 2203 | case BUILT_IN_GOMP_LOOP_END_CANCEL: |
a44814b9 | 2204 | case BUILT_IN_GOMP_ORDERED_START: |
2205 | case BUILT_IN_GOMP_ORDERED_END: | |
a44814b9 | 2206 | case BUILT_IN_GOMP_SECTIONS_END: |
bc7bff74 | 2207 | case BUILT_IN_GOMP_SECTIONS_END_CANCEL: |
a44814b9 | 2208 | case BUILT_IN_GOMP_SINGLE_COPY_START: |
2209 | case BUILT_IN_GOMP_SINGLE_COPY_END: | |
2210 | return true; | |
047fdd47 | 2211 | default: |
2212 | /* Fallthru to general call handling. */; | |
2213 | } | |
2214 | ||
dd277d48 | 2215 | /* Check if base is a global static variable that is not written |
2216 | by the function. */ | |
53e9c5c4 | 2217 | if (callee != NULL_TREE && VAR_P (base) && TREE_STATIC (base)) |
4ee9c684 | 2218 | { |
415d1b9a | 2219 | struct cgraph_node *node = cgraph_node::get (callee); |
b39960e1 | 2220 | bitmap not_written; |
0eaf9bd7 | 2221 | |
b39960e1 | 2222 | if (node |
2223 | && (not_written = ipa_reference_get_not_written_global (node)) | |
2224 | && bitmap_bit_p (not_written, ipa_reference_var_uid (base))) | |
2225 | return false; | |
4ee9c684 | 2226 | } |
4ee9c684 | 2227 | |
cb245216 | 2228 | /* Check if the base variable is call-clobbered. */ |
dd277d48 | 2229 | if (DECL_P (base)) |
cb245216 | 2230 | return pt_solution_includes (gimple_call_clobber_set (call), base); |
2622064f | 2231 | else if ((TREE_CODE (base) == MEM_REF |
2232 | || TREE_CODE (base) == TARGET_MEM_REF) | |
917f08fa | 2233 | && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME) |
2234 | { | |
2235 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0)); | |
2236 | if (!pi) | |
2237 | return true; | |
2238 | ||
cb245216 | 2239 | return pt_solutions_intersect (gimple_call_clobber_set (call), &pi->pt); |
917f08fa | 2240 | } |
4ee9c684 | 2241 | |
dd277d48 | 2242 | return true; |
2243 | } | |
4ee9c684 | 2244 | |
4debfcfc | 2245 | /* If the call in statement CALL may clobber the memory reference REF |
2246 | return true, otherwise return false. */ | |
2247 | ||
2248 | bool | |
1a91d914 | 2249 | call_may_clobber_ref_p (gcall *call, tree ref) |
4ee9c684 | 2250 | { |
3918bd18 | 2251 | bool res; |
2252 | ao_ref r; | |
2253 | ao_ref_init (&r, ref); | |
2254 | res = call_may_clobber_ref_p_1 (call, &r); | |
dd277d48 | 2255 | if (res) |
2256 | ++alias_stats.call_may_clobber_ref_p_may_alias; | |
2257 | else | |
2258 | ++alias_stats.call_may_clobber_ref_p_no_alias; | |
2259 | return res; | |
4ee9c684 | 2260 | } |
94e6573f | 2261 | |
dd277d48 | 2262 | |
2263 | /* If the statement STMT may clobber the memory reference REF return true, | |
2264 | otherwise return false. */ | |
94e6573f | 2265 | |
2266 | bool | |
58cfef6b | 2267 | stmt_may_clobber_ref_p_1 (gimple *stmt, ao_ref *ref, bool tbaa_p) |
94e6573f | 2268 | { |
dd277d48 | 2269 | if (is_gimple_call (stmt)) |
2270 | { | |
2271 | tree lhs = gimple_call_lhs (stmt); | |
2272 | if (lhs | |
66b86a74 | 2273 | && TREE_CODE (lhs) != SSA_NAME) |
3918bd18 | 2274 | { |
2275 | ao_ref r; | |
2276 | ao_ref_init (&r, lhs); | |
58cfef6b | 2277 | if (refs_may_alias_p_1 (ref, &r, tbaa_p)) |
3918bd18 | 2278 | return true; |
2279 | } | |
94e6573f | 2280 | |
1a91d914 | 2281 | return call_may_clobber_ref_p_1 (as_a <gcall *> (stmt), ref); |
dd277d48 | 2282 | } |
8e7c2b9c | 2283 | else if (gimple_assign_single_p (stmt)) |
3918bd18 | 2284 | { |
8e7c2b9c | 2285 | tree lhs = gimple_assign_lhs (stmt); |
66b86a74 | 2286 | if (TREE_CODE (lhs) != SSA_NAME) |
8e7c2b9c | 2287 | { |
2288 | ao_ref r; | |
66b86a74 | 2289 | ao_ref_init (&r, lhs); |
58cfef6b | 2290 | return refs_may_alias_p_1 (ref, &r, tbaa_p); |
8e7c2b9c | 2291 | } |
3918bd18 | 2292 | } |
dd277d48 | 2293 | else if (gimple_code (stmt) == GIMPLE_ASM) |
94e6573f | 2294 | return true; |
2295 | ||
6329636b | 2296 | return false; |
94e6573f | 2297 | } |
2be14d8b | 2298 | |
3918bd18 | 2299 | bool |
58cfef6b | 2300 | stmt_may_clobber_ref_p (gimple *stmt, tree ref, bool tbaa_p) |
3918bd18 | 2301 | { |
2302 | ao_ref r; | |
2303 | ao_ref_init (&r, ref); | |
58cfef6b | 2304 | return stmt_may_clobber_ref_p_1 (stmt, &r, tbaa_p); |
3918bd18 | 2305 | } |
2306 | ||
38cfd088 | 2307 | /* Return true if store1 and store2 described by corresponding tuples |
2308 | <BASE, OFFSET, SIZE, MAX_SIZE> have the same size and store to the same | |
2309 | address. */ | |
2310 | ||
2311 | static bool | |
2c7ce661 | 2312 | same_addr_size_stores_p (tree base1, poly_int64 offset1, poly_int64 size1, |
2313 | poly_int64 max_size1, | |
2314 | tree base2, poly_int64 offset2, poly_int64 size2, | |
2315 | poly_int64 max_size2) | |
38cfd088 | 2316 | { |
9355477b | 2317 | /* Offsets need to be 0. */ |
2c7ce661 | 2318 | if (maybe_ne (offset1, 0) |
2319 | || maybe_ne (offset2, 0)) | |
9355477b | 2320 | return false; |
2321 | ||
2322 | bool base1_obj_p = SSA_VAR_P (base1); | |
2323 | bool base2_obj_p = SSA_VAR_P (base2); | |
38cfd088 | 2324 | |
2325 | /* We need one object. */ | |
2326 | if (base1_obj_p == base2_obj_p) | |
2327 | return false; | |
2328 | tree obj = base1_obj_p ? base1 : base2; | |
2329 | ||
2330 | /* And we need one MEM_REF. */ | |
2331 | bool base1_memref_p = TREE_CODE (base1) == MEM_REF; | |
2332 | bool base2_memref_p = TREE_CODE (base2) == MEM_REF; | |
2333 | if (base1_memref_p == base2_memref_p) | |
2334 | return false; | |
2335 | tree memref = base1_memref_p ? base1 : base2; | |
2336 | ||
2337 | /* Sizes need to be valid. */ | |
2c7ce661 | 2338 | if (!known_size_p (max_size1) |
2339 | || !known_size_p (max_size2) | |
2340 | || !known_size_p (size1) | |
2341 | || !known_size_p (size2)) | |
38cfd088 | 2342 | return false; |
2343 | ||
2344 | /* Max_size needs to match size. */ | |
2c7ce661 | 2345 | if (maybe_ne (max_size1, size1) |
2346 | || maybe_ne (max_size2, size2)) | |
38cfd088 | 2347 | return false; |
2348 | ||
2349 | /* Sizes need to match. */ | |
2c7ce661 | 2350 | if (maybe_ne (size1, size2)) |
38cfd088 | 2351 | return false; |
2352 | ||
38cfd088 | 2353 | |
2354 | /* Check that memref is a store to pointer with singleton points-to info. */ | |
9355477b | 2355 | if (!integer_zerop (TREE_OPERAND (memref, 1))) |
38cfd088 | 2356 | return false; |
2357 | tree ptr = TREE_OPERAND (memref, 0); | |
2358 | if (TREE_CODE (ptr) != SSA_NAME) | |
2359 | return false; | |
2360 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr); | |
2361 | unsigned int pt_uid; | |
2362 | if (pi == NULL | |
2363 | || !pt_solution_singleton_or_null_p (&pi->pt, &pt_uid)) | |
2364 | return false; | |
2365 | ||
1922120c | 2366 | /* Be conservative with non-call exceptions when the address might |
2367 | be NULL. */ | |
2368 | if (flag_non_call_exceptions && pi->pt.null) | |
9355477b | 2369 | return false; |
2370 | ||
38cfd088 | 2371 | /* Check that ptr points relative to obj. */ |
9355477b | 2372 | unsigned int obj_uid = DECL_PT_UID (obj); |
38cfd088 | 2373 | if (obj_uid != pt_uid) |
2374 | return false; | |
2375 | ||
2376 | /* Check that the object size is the same as the store size. That ensures us | |
2377 | that ptr points to the start of obj. */ | |
2c7ce661 | 2378 | return (DECL_SIZE (obj) |
2379 | && poly_int_tree_p (DECL_SIZE (obj)) | |
2380 | && known_eq (wi::to_poly_offset (DECL_SIZE (obj)), size1)); | |
38cfd088 | 2381 | } |
2382 | ||
ab450cc6 | 2383 | /* If STMT kills the memory reference REF return true, otherwise |
2384 | return false. */ | |
2385 | ||
258bd648 | 2386 | bool |
42acab1c | 2387 | stmt_kills_ref_p (gimple *stmt, ao_ref *ref) |
ab450cc6 | 2388 | { |
2e333543 | 2389 | if (!ao_ref_base (ref)) |
07ff6a65 | 2390 | return false; |
2391 | ||
ab450cc6 | 2392 | if (gimple_has_lhs (stmt) |
e54d36c4 | 2393 | && TREE_CODE (gimple_get_lhs (stmt)) != SSA_NAME |
2394 | /* The assignment is not necessarily carried out if it can throw | |
2395 | and we can catch it in the current function where we could inspect | |
2396 | the previous value. | |
2397 | ??? We only need to care about the RHS throwing. For aggregate | |
2398 | assignments or similar calls and non-call exceptions the LHS | |
2399 | might throw as well. */ | |
aac19106 | 2400 | && !stmt_can_throw_internal (cfun, stmt)) |
ab450cc6 | 2401 | { |
2e333543 | 2402 | tree lhs = gimple_get_lhs (stmt); |
2403 | /* If LHS is literally a base of the access we are done. */ | |
2404 | if (ref->ref) | |
2405 | { | |
2406 | tree base = ref->ref; | |
272512a8 | 2407 | tree innermost_dropped_array_ref = NULL_TREE; |
2e333543 | 2408 | if (handled_component_p (base)) |
2409 | { | |
2410 | tree saved_lhs0 = NULL_TREE; | |
2411 | if (handled_component_p (lhs)) | |
2412 | { | |
2413 | saved_lhs0 = TREE_OPERAND (lhs, 0); | |
2414 | TREE_OPERAND (lhs, 0) = integer_zero_node; | |
2415 | } | |
2416 | do | |
2417 | { | |
2418 | /* Just compare the outermost handled component, if | |
2419 | they are equal we have found a possible common | |
2420 | base. */ | |
2421 | tree saved_base0 = TREE_OPERAND (base, 0); | |
2422 | TREE_OPERAND (base, 0) = integer_zero_node; | |
2423 | bool res = operand_equal_p (lhs, base, 0); | |
2424 | TREE_OPERAND (base, 0) = saved_base0; | |
2425 | if (res) | |
2426 | break; | |
272512a8 | 2427 | /* Remember if we drop an array-ref that we need to |
2428 | double-check not being at struct end. */ | |
2429 | if (TREE_CODE (base) == ARRAY_REF | |
2430 | || TREE_CODE (base) == ARRAY_RANGE_REF) | |
2431 | innermost_dropped_array_ref = base; | |
2e333543 | 2432 | /* Otherwise drop handled components of the access. */ |
2433 | base = saved_base0; | |
2434 | } | |
2435 | while (handled_component_p (base)); | |
2436 | if (saved_lhs0) | |
2437 | TREE_OPERAND (lhs, 0) = saved_lhs0; | |
2438 | } | |
11beb29c | 2439 | /* Finally check if the lhs has the same address and size as the |
272512a8 | 2440 | base candidate of the access. Watch out if we have dropped |
2441 | an array-ref that was at struct end, this means ref->ref may | |
2442 | be outside of the TYPE_SIZE of its base. */ | |
2443 | if ((! innermost_dropped_array_ref | |
2444 | || ! array_at_struct_end_p (innermost_dropped_array_ref)) | |
2445 | && (lhs == base | |
2446 | || (((TYPE_SIZE (TREE_TYPE (lhs)) | |
2447 | == TYPE_SIZE (TREE_TYPE (base))) | |
2448 | || (TYPE_SIZE (TREE_TYPE (lhs)) | |
2449 | && TYPE_SIZE (TREE_TYPE (base)) | |
2450 | && operand_equal_p (TYPE_SIZE (TREE_TYPE (lhs)), | |
2451 | TYPE_SIZE (TREE_TYPE (base)), | |
2452 | 0))) | |
2453 | && operand_equal_p (lhs, base, | |
2454 | OEP_ADDRESS_OF | |
2455 | | OEP_MATCH_SIDE_EFFECTS)))) | |
2e333543 | 2456 | return true; |
2457 | } | |
2458 | ||
2459 | /* Now look for non-literal equal bases with the restriction of | |
2460 | handling constant offset and size. */ | |
2461 | /* For a must-alias check we need to be able to constrain | |
2462 | the access properly. */ | |
fe60c82c | 2463 | if (!ref->max_size_known_p ()) |
2e333543 | 2464 | return false; |
f3c2a387 | 2465 | poly_int64 size, offset, max_size, ref_offset = ref->offset; |
292237f3 | 2466 | bool reverse; |
f3c2a387 | 2467 | tree base = get_ref_base_and_extent (lhs, &offset, &size, &max_size, |
2468 | &reverse); | |
ab450cc6 | 2469 | /* We can get MEM[symbol: sZ, index: D.8862_1] here, |
2470 | so base == ref->base does not always hold. */ | |
137eddca | 2471 | if (base != ref->base) |
ab450cc6 | 2472 | { |
38cfd088 | 2473 | /* Try using points-to info. */ |
2474 | if (same_addr_size_stores_p (base, offset, size, max_size, ref->base, | |
2475 | ref->offset, ref->size, ref->max_size)) | |
2476 | return true; | |
2477 | ||
137eddca | 2478 | /* If both base and ref->base are MEM_REFs, only compare the |
2479 | first operand, and if the second operand isn't equal constant, | |
2480 | try to add the offsets into offset and ref_offset. */ | |
2481 | if (TREE_CODE (base) == MEM_REF && TREE_CODE (ref->base) == MEM_REF | |
2482 | && TREE_OPERAND (base, 0) == TREE_OPERAND (ref->base, 0)) | |
ab450cc6 | 2483 | { |
83d18d6d | 2484 | if (!tree_int_cst_equal (TREE_OPERAND (base, 1), |
2485 | TREE_OPERAND (ref->base, 1))) | |
137eddca | 2486 | { |
fe60c82c | 2487 | poly_offset_int off1 = mem_ref_offset (base); |
9fdc1ed4 | 2488 | off1 <<= LOG2_BITS_PER_UNIT; |
e913b5cd | 2489 | off1 += offset; |
fe60c82c | 2490 | poly_offset_int off2 = mem_ref_offset (ref->base); |
9fdc1ed4 | 2491 | off2 <<= LOG2_BITS_PER_UNIT; |
e913b5cd | 2492 | off2 += ref_offset; |
fe60c82c | 2493 | if (!off1.to_shwi (&offset) || !off2.to_shwi (&ref_offset)) |
137eddca | 2494 | size = -1; |
2495 | } | |
ab450cc6 | 2496 | } |
137eddca | 2497 | else |
2498 | size = -1; | |
2499 | } | |
2500 | /* For a must-alias check we need to be able to constrain | |
2501 | the access properly. */ | |
f3c2a387 | 2502 | if (known_eq (size, max_size) |
fe60c82c | 2503 | && known_subrange_p (ref_offset, ref->max_size, offset, size)) |
2504 | return true; | |
ab450cc6 | 2505 | } |
07ff6a65 | 2506 | |
2507 | if (is_gimple_call (stmt)) | |
2508 | { | |
2509 | tree callee = gimple_call_fndecl (stmt); | |
2510 | if (callee != NULL_TREE | |
6189000c | 2511 | && gimple_call_builtin_p (stmt, BUILT_IN_NORMAL)) |
07ff6a65 | 2512 | switch (DECL_FUNCTION_CODE (callee)) |
2513 | { | |
3d0ea943 | 2514 | case BUILT_IN_FREE: |
2515 | { | |
2516 | tree ptr = gimple_call_arg (stmt, 0); | |
2517 | tree base = ao_ref_base (ref); | |
2518 | if (base && TREE_CODE (base) == MEM_REF | |
2519 | && TREE_OPERAND (base, 0) == ptr) | |
2520 | return true; | |
2521 | break; | |
2522 | } | |
2523 | ||
07ff6a65 | 2524 | case BUILT_IN_MEMCPY: |
2525 | case BUILT_IN_MEMPCPY: | |
2526 | case BUILT_IN_MEMMOVE: | |
2527 | case BUILT_IN_MEMSET: | |
939514e9 | 2528 | case BUILT_IN_MEMCPY_CHK: |
2529 | case BUILT_IN_MEMPCPY_CHK: | |
2530 | case BUILT_IN_MEMMOVE_CHK: | |
2531 | case BUILT_IN_MEMSET_CHK: | |
3fead063 | 2532 | case BUILT_IN_STRNCPY: |
2533 | case BUILT_IN_STPNCPY: | |
07ff6a65 | 2534 | { |
2e333543 | 2535 | /* For a must-alias check we need to be able to constrain |
2536 | the access properly. */ | |
fe60c82c | 2537 | if (!ref->max_size_known_p ()) |
2e333543 | 2538 | return false; |
07ff6a65 | 2539 | tree dest = gimple_call_arg (stmt, 0); |
2540 | tree len = gimple_call_arg (stmt, 2); | |
fe60c82c | 2541 | if (!poly_int_tree_p (len)) |
07ff6a65 | 2542 | return false; |
e6c705fb | 2543 | tree rbase = ref->base; |
fe60c82c | 2544 | poly_offset_int roffset = ref->offset; |
e6c705fb | 2545 | ao_ref dref; |
2546 | ao_ref_init_from_ptr_and_size (&dref, dest, len); | |
2547 | tree base = ao_ref_base (&dref); | |
fe60c82c | 2548 | poly_offset_int offset = dref.offset; |
2549 | if (!base || !known_size_p (dref.size)) | |
e6c705fb | 2550 | return false; |
2551 | if (TREE_CODE (base) == MEM_REF) | |
2552 | { | |
2553 | if (TREE_CODE (rbase) != MEM_REF) | |
2554 | return false; | |
2555 | // Compare pointers. | |
9fdc1ed4 | 2556 | offset += mem_ref_offset (base) << LOG2_BITS_PER_UNIT; |
2557 | roffset += mem_ref_offset (rbase) << LOG2_BITS_PER_UNIT; | |
e6c705fb | 2558 | base = TREE_OPERAND (base, 0); |
2559 | rbase = TREE_OPERAND (rbase, 0); | |
2560 | } | |
2315e038 | 2561 | if (base == rbase |
fe60c82c | 2562 | && known_subrange_p (roffset, ref->max_size, offset, |
2563 | wi::to_poly_offset (len) | |
2564 | << LOG2_BITS_PER_UNIT)) | |
2315e038 | 2565 | return true; |
9d17b4a8 | 2566 | break; |
2567 | } | |
2568 | ||
2569 | case BUILT_IN_VA_END: | |
2570 | { | |
2571 | tree ptr = gimple_call_arg (stmt, 0); | |
2572 | if (TREE_CODE (ptr) == ADDR_EXPR) | |
2573 | { | |
2574 | tree base = ao_ref_base (ref); | |
2575 | if (TREE_OPERAND (ptr, 0) == base) | |
2576 | return true; | |
2577 | } | |
2578 | break; | |
07ff6a65 | 2579 | } |
9d17b4a8 | 2580 | |
07ff6a65 | 2581 | default:; |
2582 | } | |
07ff6a65 | 2583 | } |
ab450cc6 | 2584 | return false; |
2585 | } | |
2586 | ||
2587 | bool | |
42acab1c | 2588 | stmt_kills_ref_p (gimple *stmt, tree ref) |
ab450cc6 | 2589 | { |
2590 | ao_ref r; | |
2591 | ao_ref_init (&r, ref); | |
258bd648 | 2592 | return stmt_kills_ref_p (stmt, &r); |
ab450cc6 | 2593 | } |
2594 | ||
3918bd18 | 2595 | |
dd277d48 | 2596 | /* Walk the virtual use-def chain of VUSE until hitting the virtual operand |
2597 | TARGET or a statement clobbering the memory reference REF in which | |
2598 | case false is returned. The walk starts with VUSE, one argument of PHI. */ | |
2599 | ||
2600 | static bool | |
42acab1c | 2601 | maybe_skip_until (gimple *phi, tree target, ao_ref *ref, |
4fd7a6de | 2602 | tree vuse, unsigned int *cnt, bitmap *visited, |
38168b16 | 2603 | bool abort_on_visited, |
dddafd79 | 2604 | void *(*translate)(ao_ref *, tree, void *, bool *), |
38168b16 | 2605 | void *data) |
ac926412 | 2606 | { |
0afe880d | 2607 | basic_block bb = gimple_bb (phi); |
2608 | ||
dd277d48 | 2609 | if (!*visited) |
2610 | *visited = BITMAP_ALLOC (NULL); | |
ac926412 | 2611 | |
dd277d48 | 2612 | bitmap_set_bit (*visited, SSA_NAME_VERSION (PHI_RESULT (phi))); |
2613 | ||
2614 | /* Walk until we hit the target. */ | |
2615 | while (vuse != target) | |
ac926412 | 2616 | { |
42acab1c | 2617 | gimple *def_stmt = SSA_NAME_DEF_STMT (vuse); |
dd277d48 | 2618 | /* Recurse for PHI nodes. */ |
2619 | if (gimple_code (def_stmt) == GIMPLE_PHI) | |
2620 | { | |
2621 | /* An already visited PHI node ends the walk successfully. */ | |
2622 | if (bitmap_bit_p (*visited, SSA_NAME_VERSION (PHI_RESULT (def_stmt)))) | |
4fd7a6de | 2623 | return !abort_on_visited; |
2624 | vuse = get_continuation_for_phi (def_stmt, ref, cnt, | |
38168b16 | 2625 | visited, abort_on_visited, |
2626 | translate, data); | |
dd277d48 | 2627 | if (!vuse) |
2628 | return false; | |
2629 | continue; | |
2630 | } | |
297a2110 | 2631 | else if (gimple_nop_p (def_stmt)) |
dd277d48 | 2632 | return false; |
297a2110 | 2633 | else |
2634 | { | |
2635 | /* A clobbering statement or the end of the IL ends it failing. */ | |
2636 | ++*cnt; | |
2637 | if (stmt_may_clobber_ref_p_1 (def_stmt, ref)) | |
38168b16 | 2638 | { |
dddafd79 | 2639 | bool disambiguate_only = true; |
38168b16 | 2640 | if (translate |
dddafd79 | 2641 | && (*translate) (ref, vuse, data, &disambiguate_only) == NULL) |
38168b16 | 2642 | ; |
2643 | else | |
2644 | return false; | |
2645 | } | |
297a2110 | 2646 | } |
0afe880d | 2647 | /* If we reach a new basic-block see if we already skipped it |
2648 | in a previous walk that ended successfully. */ | |
2649 | if (gimple_bb (def_stmt) != bb) | |
2650 | { | |
2651 | if (!bitmap_set_bit (*visited, SSA_NAME_VERSION (vuse))) | |
4fd7a6de | 2652 | return !abort_on_visited; |
0afe880d | 2653 | bb = gimple_bb (def_stmt); |
2654 | } | |
dd277d48 | 2655 | vuse = gimple_vuse (def_stmt); |
ac926412 | 2656 | } |
dd277d48 | 2657 | return true; |
2658 | } | |
ac926412 | 2659 | |
d7f69727 | 2660 | |
dd277d48 | 2661 | /* Starting from a PHI node for the virtual operand of the memory reference |
2662 | REF find a continuation virtual operand that allows to continue walking | |
2663 | statements dominating PHI skipping only statements that cannot possibly | |
297a2110 | 2664 | clobber REF. Increments *CNT for each alias disambiguation done. |
2665 | Returns NULL_TREE if no suitable virtual operand can be found. */ | |
dd277d48 | 2666 | |
7814d418 | 2667 | tree |
42acab1c | 2668 | get_continuation_for_phi (gimple *phi, ao_ref *ref, |
4fd7a6de | 2669 | unsigned int *cnt, bitmap *visited, |
38168b16 | 2670 | bool abort_on_visited, |
dddafd79 | 2671 | void *(*translate)(ao_ref *, tree, void *, bool *), |
38168b16 | 2672 | void *data) |
dd277d48 | 2673 | { |
2674 | unsigned nargs = gimple_phi_num_args (phi); | |
2675 | ||
2676 | /* Through a single-argument PHI we can simply look through. */ | |
2677 | if (nargs == 1) | |
2678 | return PHI_ARG_DEF (phi, 0); | |
2679 | ||
d7f69727 | 2680 | /* For two or more arguments try to pairwise skip non-aliasing code |
2681 | until we hit the phi argument definition that dominates the other one. */ | |
91f19afb | 2682 | basic_block phi_bb = gimple_bb (phi); |
2683 | tree arg0, arg1; | |
2684 | unsigned i; | |
2685 | ||
2686 | /* Find a candidate for the virtual operand which definition | |
2687 | dominates those of all others. */ | |
2688 | /* First look if any of the args themselves satisfy this. */ | |
2689 | for (i = 0; i < nargs; ++i) | |
ac926412 | 2690 | { |
91f19afb | 2691 | arg0 = PHI_ARG_DEF (phi, i); |
2692 | if (SSA_NAME_IS_DEFAULT_DEF (arg0)) | |
2693 | break; | |
2694 | basic_block def_bb = gimple_bb (SSA_NAME_DEF_STMT (arg0)); | |
2695 | if (def_bb != phi_bb | |
2696 | && dominated_by_p (CDI_DOMINATORS, phi_bb, def_bb)) | |
2697 | break; | |
2698 | arg0 = NULL_TREE; | |
2699 | } | |
2700 | /* If not, look if we can reach such candidate by walking defs | |
2701 | of a PHI arg without crossing other PHIs. */ | |
2702 | if (! arg0) | |
2703 | for (i = 0; i < nargs; ++i) | |
2704 | { | |
2705 | arg0 = PHI_ARG_DEF (phi, i); | |
2706 | gimple *def = SSA_NAME_DEF_STMT (arg0); | |
2707 | /* Backedges can't work. */ | |
2708 | if (dominated_by_p (CDI_DOMINATORS, | |
2709 | gimple_bb (def), phi_bb)) | |
2710 | continue; | |
2711 | /* See below. */ | |
2712 | if (gimple_code (def) == GIMPLE_PHI) | |
2713 | continue; | |
2714 | while (! dominated_by_p (CDI_DOMINATORS, | |
2715 | phi_bb, gimple_bb (def))) | |
0afe880d | 2716 | { |
91f19afb | 2717 | arg0 = gimple_vuse (def); |
2718 | if (SSA_NAME_IS_DEFAULT_DEF (arg0)) | |
2719 | break; | |
2720 | def = SSA_NAME_DEF_STMT (arg0); | |
2721 | if (gimple_code (def) == GIMPLE_PHI) | |
0afe880d | 2722 | { |
91f19afb | 2723 | /* Do not try to look through arbitrarily complicated |
2724 | CFGs. For those looking for the first VUSE starting | |
2725 | from the end of the immediate dominator of phi_bb | |
2726 | is likely faster. */ | |
2727 | arg0 = NULL_TREE; | |
2728 | goto next; | |
0afe880d | 2729 | } |
0afe880d | 2730 | } |
91f19afb | 2731 | break; |
2732 | next:; | |
2733 | } | |
2734 | if (! arg0) | |
2735 | return NULL_TREE; | |
0afe880d | 2736 | |
91f19afb | 2737 | /* Then check against the found candidate. */ |
2738 | for (i = 0; i < nargs; ++i) | |
2739 | { | |
2740 | arg1 = PHI_ARG_DEF (phi, i); | |
2741 | if (arg1 == arg0) | |
2742 | ; | |
2743 | else if (! maybe_skip_until (phi, arg0, ref, arg1, cnt, visited, | |
b87672f7 | 2744 | abort_on_visited, |
2745 | /* Do not translate when walking over | |
2746 | backedges. */ | |
2747 | dominated_by_p | |
2748 | (CDI_DOMINATORS, | |
2749 | gimple_bb (SSA_NAME_DEF_STMT (arg1)), | |
2750 | phi_bb) | |
2751 | ? NULL : translate, data)) | |
91f19afb | 2752 | return NULL_TREE; |
ac926412 | 2753 | } |
dd277d48 | 2754 | |
91f19afb | 2755 | return arg0; |
ac926412 | 2756 | } |
516849c7 | 2757 | |
dd277d48 | 2758 | /* Based on the memory reference REF and its virtual use VUSE call |
2759 | WALKER for each virtual use that is equivalent to VUSE, including VUSE | |
2760 | itself. That is, for each virtual use for which its defining statement | |
2761 | does not clobber REF. | |
e683de6d | 2762 | |
dd277d48 | 2763 | WALKER is called with REF, the current virtual use and DATA. If |
2764 | WALKER returns non-NULL the walk stops and its result is returned. | |
2765 | At the end of a non-successful walk NULL is returned. | |
3857274c | 2766 | |
d8021dea | 2767 | TRANSLATE if non-NULL is called with a pointer to REF, the virtual |
2768 | use which definition is a statement that may clobber REF and DATA. | |
2769 | If TRANSLATE returns (void *)-1 the walk stops and NULL is returned. | |
2770 | If TRANSLATE returns non-NULL the walk stops and its result is returned. | |
2771 | If TRANSLATE returns NULL the walk continues and TRANSLATE is supposed | |
2772 | to adjust REF and *DATA to make that valid. | |
2773 | ||
46816709 | 2774 | VALUEIZE if non-NULL is called with the next VUSE that is considered |
2775 | and return value is substituted for that. This can be used to | |
2776 | implement optimistic value-numbering for example. Note that the | |
2777 | VUSE argument is assumed to be valueized already. | |
2778 | ||
dd277d48 | 2779 | TODO: Cache the vector of equivalent vuses per ref, vuse pair. */ |
2780 | ||
2781 | void * | |
3918bd18 | 2782 | walk_non_aliased_vuses (ao_ref *ref, tree vuse, |
297a2110 | 2783 | void *(*walker)(ao_ref *, tree, unsigned int, void *), |
dddafd79 | 2784 | void *(*translate)(ao_ref *, tree, void *, bool *), |
46816709 | 2785 | tree (*valueize)(tree), |
38168b16 | 2786 | void *data) |
3857274c | 2787 | { |
dd277d48 | 2788 | bitmap visited = NULL; |
2789 | void *res; | |
297a2110 | 2790 | unsigned int cnt = 0; |
4fd7a6de | 2791 | bool translated = false; |
dd277d48 | 2792 | |
02c74b9b | 2793 | timevar_push (TV_ALIAS_STMT_WALK); |
2794 | ||
dd277d48 | 2795 | do |
2796 | { | |
42acab1c | 2797 | gimple *def_stmt; |
3857274c | 2798 | |
02c74b9b | 2799 | /* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */ |
297a2110 | 2800 | res = (*walker) (ref, vuse, cnt, data); |
2801 | /* Abort walk. */ | |
2802 | if (res == (void *)-1) | |
2803 | { | |
2804 | res = NULL; | |
2805 | break; | |
2806 | } | |
2807 | /* Lookup succeeded. */ | |
2808 | else if (res != NULL) | |
dd277d48 | 2809 | break; |
3857274c | 2810 | |
46816709 | 2811 | if (valueize) |
51e85e64 | 2812 | { |
2813 | vuse = valueize (vuse); | |
2814 | if (!vuse) | |
2815 | { | |
2816 | res = NULL; | |
2817 | break; | |
2818 | } | |
2819 | } | |
dd277d48 | 2820 | def_stmt = SSA_NAME_DEF_STMT (vuse); |
2821 | if (gimple_nop_p (def_stmt)) | |
2822 | break; | |
2823 | else if (gimple_code (def_stmt) == GIMPLE_PHI) | |
4fd7a6de | 2824 | vuse = get_continuation_for_phi (def_stmt, ref, &cnt, |
38168b16 | 2825 | &visited, translated, translate, data); |
dd277d48 | 2826 | else |
2827 | { | |
297a2110 | 2828 | cnt++; |
3918bd18 | 2829 | if (stmt_may_clobber_ref_p_1 (def_stmt, ref)) |
d8021dea | 2830 | { |
2831 | if (!translate) | |
2832 | break; | |
dddafd79 | 2833 | bool disambiguate_only = false; |
2834 | res = (*translate) (ref, vuse, data, &disambiguate_only); | |
d8021dea | 2835 | /* Failed lookup and translation. */ |
2836 | if (res == (void *)-1) | |
2837 | { | |
2838 | res = NULL; | |
2839 | break; | |
2840 | } | |
2841 | /* Lookup succeeded. */ | |
2842 | else if (res != NULL) | |
2843 | break; | |
2844 | /* Translation succeeded, continue walking. */ | |
dddafd79 | 2845 | translated = translated || !disambiguate_only; |
d8021dea | 2846 | } |
dd277d48 | 2847 | vuse = gimple_vuse (def_stmt); |
2848 | } | |
2849 | } | |
2850 | while (vuse); | |
ac926412 | 2851 | |
dd277d48 | 2852 | if (visited) |
2853 | BITMAP_FREE (visited); | |
ac926412 | 2854 | |
02c74b9b | 2855 | timevar_pop (TV_ALIAS_STMT_WALK); |
2856 | ||
dd277d48 | 2857 | return res; |
3857274c | 2858 | } |
2859 | ||
604eef2c | 2860 | |
dd277d48 | 2861 | /* Based on the memory reference REF call WALKER for each vdef which |
2862 | defining statement may clobber REF, starting with VDEF. If REF | |
2863 | is NULL_TREE, each defining statement is visited. | |
2864 | ||
2865 | WALKER is called with REF, the current vdef and DATA. If WALKER | |
2866 | returns true the walk is stopped, otherwise it continues. | |
2867 | ||
f91737f9 | 2868 | If function entry is reached, FUNCTION_ENTRY_REACHED is set to true. |
2869 | The pointer may be NULL and then we do not track this information. | |
2870 | ||
dd277d48 | 2871 | At PHI nodes walk_aliased_vdefs forks into one walk for reach |
2872 | PHI argument (but only one walk continues on merge points), the | |
2873 | return value is true if any of the walks was successful. | |
2874 | ||
4d2b9d1e | 2875 | The function returns the number of statements walked or -1 if |
2876 | LIMIT stmts were walked and the walk was aborted at this point. | |
2877 | If LIMIT is zero the walk is not aborted. */ | |
604eef2c | 2878 | |
4d2b9d1e | 2879 | static int |
1daead67 | 2880 | walk_aliased_vdefs_1 (ao_ref *ref, tree vdef, |
2881 | bool (*walker)(ao_ref *, tree, void *), void *data, | |
f91737f9 | 2882 | bitmap *visited, unsigned int cnt, |
4d2b9d1e | 2883 | bool *function_entry_reached, unsigned limit) |
604eef2c | 2884 | { |
dd277d48 | 2885 | do |
2886 | { | |
42acab1c | 2887 | gimple *def_stmt = SSA_NAME_DEF_STMT (vdef); |
604eef2c | 2888 | |
dd277d48 | 2889 | if (*visited |
2890 | && !bitmap_set_bit (*visited, SSA_NAME_VERSION (vdef))) | |
2891 | return cnt; | |
2892 | ||
2893 | if (gimple_nop_p (def_stmt)) | |
f91737f9 | 2894 | { |
2895 | if (function_entry_reached) | |
2896 | *function_entry_reached = true; | |
2897 | return cnt; | |
2898 | } | |
dd277d48 | 2899 | else if (gimple_code (def_stmt) == GIMPLE_PHI) |
2900 | { | |
2901 | unsigned i; | |
2902 | if (!*visited) | |
2903 | *visited = BITMAP_ALLOC (NULL); | |
2904 | for (i = 0; i < gimple_phi_num_args (def_stmt); ++i) | |
4d2b9d1e | 2905 | { |
2906 | int res = walk_aliased_vdefs_1 (ref, | |
2907 | gimple_phi_arg_def (def_stmt, i), | |
2908 | walker, data, visited, cnt, | |
2909 | function_entry_reached, limit); | |
2910 | if (res == -1) | |
2911 | return -1; | |
2912 | cnt = res; | |
2913 | } | |
dd277d48 | 2914 | return cnt; |
2915 | } | |
2916 | ||
02c74b9b | 2917 | /* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */ |
dd277d48 | 2918 | cnt++; |
4d2b9d1e | 2919 | if (cnt == limit) |
2920 | return -1; | |
dd277d48 | 2921 | if ((!ref |
1daead67 | 2922 | || stmt_may_clobber_ref_p_1 (def_stmt, ref)) |
dd277d48 | 2923 | && (*walker) (ref, vdef, data)) |
2924 | return cnt; | |
2925 | ||
2926 | vdef = gimple_vuse (def_stmt); | |
2927 | } | |
2928 | while (1); | |
604eef2c | 2929 | } |
2930 | ||
4d2b9d1e | 2931 | int |
1daead67 | 2932 | walk_aliased_vdefs (ao_ref *ref, tree vdef, |
2933 | bool (*walker)(ao_ref *, tree, void *), void *data, | |
f91737f9 | 2934 | bitmap *visited, |
4d2b9d1e | 2935 | bool *function_entry_reached, unsigned int limit) |
df3f0669 | 2936 | { |
dd277d48 | 2937 | bitmap local_visited = NULL; |
4d2b9d1e | 2938 | int ret; |
dd277d48 | 2939 | |
02c74b9b | 2940 | timevar_push (TV_ALIAS_STMT_WALK); |
2941 | ||
325396bf | 2942 | if (function_entry_reached) |
2943 | *function_entry_reached = false; | |
2944 | ||
dd277d48 | 2945 | ret = walk_aliased_vdefs_1 (ref, vdef, walker, data, |
f91737f9 | 2946 | visited ? visited : &local_visited, 0, |
4d2b9d1e | 2947 | function_entry_reached, limit); |
dd277d48 | 2948 | if (local_visited) |
2949 | BITMAP_FREE (local_visited); | |
2950 | ||
02c74b9b | 2951 | timevar_pop (TV_ALIAS_STMT_WALK); |
2952 | ||
dd277d48 | 2953 | return ret; |
2954 | } | |
2955 |