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4ee9c684 | 1 | /* Alias analysis for trees. |
cfaf579d | 2 | Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 |
3 | Free Software Foundation, Inc. | |
4ee9c684 | 4 | Contributed by Diego Novillo <dnovillo@redhat.com> |
5 | ||
6 | This file is part of GCC. | |
7 | ||
8 | GCC is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
8c4c00c1 | 10 | the Free Software Foundation; either version 3, or (at your option) |
4ee9c684 | 11 | any later version. |
12 | ||
13 | GCC is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
8c4c00c1 | 19 | along with GCC; see the file COPYING3. If not see |
20 | <http://www.gnu.org/licenses/>. */ | |
4ee9c684 | 21 | |
22 | #include "config.h" | |
23 | #include "system.h" | |
24 | #include "coretypes.h" | |
25 | #include "tm.h" | |
26 | #include "tree.h" | |
27 | #include "rtl.h" | |
28 | #include "tm_p.h" | |
29 | #include "hard-reg-set.h" | |
30 | #include "basic-block.h" | |
31 | #include "timevar.h" | |
32 | #include "expr.h" | |
33 | #include "ggc.h" | |
34 | #include "langhooks.h" | |
35 | #include "flags.h" | |
36 | #include "function.h" | |
37 | #include "diagnostic.h" | |
38 | #include "tree-dump.h" | |
75a70cf9 | 39 | #include "gimple.h" |
4ee9c684 | 40 | #include "tree-flow.h" |
41 | #include "tree-inline.h" | |
4ee9c684 | 42 | #include "tree-pass.h" |
43 | #include "convert.h" | |
44 | #include "params.h" | |
f7d118a9 | 45 | #include "ipa-type-escape.h" |
2be14d8b | 46 | #include "vec.h" |
a55dc2cd | 47 | #include "bitmap.h" |
05f3df98 | 48 | #include "vecprim.h" |
4fb5e5ca | 49 | #include "pointer-set.h" |
6cc9bd27 | 50 | #include "alloc-pool.h" |
dd277d48 | 51 | #include "tree-ssa-alias.h" |
a55dc2cd | 52 | |
dd277d48 | 53 | /* Broad overview of how alias analysis on gimple works: |
4fb5e5ca | 54 | |
dd277d48 | 55 | Statements clobbering or using memory are linked through the |
56 | virtual operand factored use-def chain. The virtual operand | |
57 | is unique per function, its symbol is accessible via gimple_vop (cfun). | |
58 | Virtual operands are used for efficiently walking memory statements | |
59 | in the gimple IL and are useful for things like value-numbering as | |
60 | a generation count for memory references. | |
339d7079 | 61 | |
dd277d48 | 62 | SSA_NAME pointers may have associated points-to information |
63 | accessible via the SSA_NAME_PTR_INFO macro. Flow-insensitive | |
64 | points-to information is (re-)computed by the TODO_rebuild_alias | |
65 | pass manager todo. Points-to information is also used for more | |
66 | precise tracking of call-clobbered and call-used variables and | |
67 | related disambiguations. | |
339d7079 | 68 | |
dd277d48 | 69 | This file contains functions for disambiguating memory references, |
70 | the so called alias-oracle and tools for walking of the gimple IL. | |
339d7079 | 71 | |
dd277d48 | 72 | The main alias-oracle entry-points are |
339d7079 | 73 | |
dd277d48 | 74 | bool stmt_may_clobber_ref_p (gimple, tree) |
339d7079 | 75 | |
dd277d48 | 76 | This function queries if a statement may invalidate (parts of) |
77 | the memory designated by the reference tree argument. | |
339d7079 | 78 | |
dd277d48 | 79 | bool ref_maybe_used_by_stmt_p (gimple, tree) |
339d7079 | 80 | |
dd277d48 | 81 | This function queries if a statement may need (parts of) the |
82 | memory designated by the reference tree argument. | |
339d7079 | 83 | |
dd277d48 | 84 | There are variants of these functions that only handle the call |
85 | part of a statement, call_may_clobber_ref_p and ref_maybe_used_by_call_p. | |
86 | Note that these do not disambiguate against a possible call lhs. | |
339d7079 | 87 | |
dd277d48 | 88 | bool refs_may_alias_p (tree, tree) |
339d7079 | 89 | |
dd277d48 | 90 | This function tries to disambiguate two reference trees. |
05931b00 | 91 | |
dd277d48 | 92 | bool ptr_deref_may_alias_global_p (tree) |
339d7079 | 93 | |
dd277d48 | 94 | This function queries if dereferencing a pointer variable may |
95 | alias global memory. | |
339d7079 | 96 | |
dd277d48 | 97 | More low-level disambiguators are available and documented in |
98 | this file. Low-level disambiguators dealing with points-to | |
99 | information are in tree-ssa-structalias.c. */ | |
339d7079 | 100 | |
339d7079 | 101 | |
dd277d48 | 102 | /* Query statistics for the different low-level disambiguators. |
103 | A high-level query may trigger multiple of them. */ | |
339d7079 | 104 | |
dd277d48 | 105 | static struct { |
106 | unsigned HOST_WIDE_INT refs_may_alias_p_may_alias; | |
107 | unsigned HOST_WIDE_INT refs_may_alias_p_no_alias; | |
108 | unsigned HOST_WIDE_INT ref_maybe_used_by_call_p_may_alias; | |
109 | unsigned HOST_WIDE_INT ref_maybe_used_by_call_p_no_alias; | |
110 | unsigned HOST_WIDE_INT call_may_clobber_ref_p_may_alias; | |
111 | unsigned HOST_WIDE_INT call_may_clobber_ref_p_no_alias; | |
112 | } alias_stats; | |
339d7079 | 113 | |
dd277d48 | 114 | void |
115 | dump_alias_stats (FILE *s) | |
116 | { | |
117 | fprintf (s, "\nAlias oracle query stats:\n"); | |
118 | fprintf (s, " refs_may_alias_p: " | |
119 | HOST_WIDE_INT_PRINT_DEC" disambiguations, " | |
120 | HOST_WIDE_INT_PRINT_DEC" queries\n", | |
121 | alias_stats.refs_may_alias_p_no_alias, | |
122 | alias_stats.refs_may_alias_p_no_alias | |
123 | + alias_stats.refs_may_alias_p_may_alias); | |
124 | fprintf (s, " ref_maybe_used_by_call_p: " | |
125 | HOST_WIDE_INT_PRINT_DEC" disambiguations, " | |
126 | HOST_WIDE_INT_PRINT_DEC" queries\n", | |
127 | alias_stats.ref_maybe_used_by_call_p_no_alias, | |
128 | alias_stats.refs_may_alias_p_no_alias | |
129 | + alias_stats.ref_maybe_used_by_call_p_may_alias); | |
130 | fprintf (s, " call_may_clobber_ref_p: " | |
131 | HOST_WIDE_INT_PRINT_DEC" disambiguations, " | |
132 | HOST_WIDE_INT_PRINT_DEC" queries\n", | |
133 | alias_stats.call_may_clobber_ref_p_no_alias, | |
134 | alias_stats.call_may_clobber_ref_p_no_alias | |
135 | + alias_stats.call_may_clobber_ref_p_may_alias); | |
136 | } | |
137 | ||
138 | ||
139 | /* Return true, if dereferencing PTR may alias with a global variable. */ | |
4ee9c684 | 140 | |
dd277d48 | 141 | bool |
142 | ptr_deref_may_alias_global_p (tree ptr) | |
4ee9c684 | 143 | { |
dd277d48 | 144 | struct ptr_info_def *pi; |
4fb5e5ca | 145 | |
dd277d48 | 146 | /* If we end up with a pointer constant here that may point |
147 | to global memory. */ | |
148 | if (TREE_CODE (ptr) != SSA_NAME) | |
149 | return true; | |
4ee9c684 | 150 | |
dd277d48 | 151 | pi = SSA_NAME_PTR_INFO (ptr); |
4ee9c684 | 152 | |
dd277d48 | 153 | /* If we do not have points-to information for this variable, |
154 | we have to punt. */ | |
155 | if (!pi) | |
156 | return true; | |
4ee9c684 | 157 | |
2a3ebafa | 158 | /* ??? This does not use TBAA to prune globals ptr may not access. */ |
dd277d48 | 159 | return pt_solution_includes_global (&pi->pt); |
4ee9c684 | 160 | } |
161 | ||
2a3ebafa | 162 | /* Return true if dereferencing PTR may alias DECL. |
163 | The caller is responsible for applying TBAA to see if PTR | |
164 | may access DECL at all. */ | |
4ee9c684 | 165 | |
dd277d48 | 166 | static bool |
167 | ptr_deref_may_alias_decl_p (tree ptr, tree decl) | |
4ee9c684 | 168 | { |
dd277d48 | 169 | struct ptr_info_def *pi; |
f7d118a9 | 170 | |
f85fb819 | 171 | gcc_assert ((TREE_CODE (ptr) == SSA_NAME |
172 | || TREE_CODE (ptr) == ADDR_EXPR | |
173 | || TREE_CODE (ptr) == INTEGER_CST) | |
174 | && (TREE_CODE (decl) == VAR_DECL | |
175 | || TREE_CODE (decl) == PARM_DECL | |
176 | || TREE_CODE (decl) == RESULT_DECL)); | |
2fd0b5dc | 177 | |
dd277d48 | 178 | /* Non-aliased variables can not be pointed to. */ |
179 | if (!may_be_aliased (decl)) | |
180 | return false; | |
2fd0b5dc | 181 | |
047fdd47 | 182 | /* ADDR_EXPR pointers either just offset another pointer or directly |
183 | specify the pointed-to set. */ | |
184 | if (TREE_CODE (ptr) == ADDR_EXPR) | |
185 | { | |
186 | tree base = get_base_address (TREE_OPERAND (ptr, 0)); | |
187 | if (base | |
188 | && INDIRECT_REF_P (base)) | |
189 | ptr = TREE_OPERAND (base, 0); | |
190 | else if (base | |
191 | && SSA_VAR_P (base)) | |
192 | return operand_equal_p (base, decl, 0); | |
193 | else if (base | |
194 | && CONSTANT_CLASS_P (base)) | |
195 | return false; | |
196 | else | |
197 | return true; | |
198 | } | |
199 | ||
f85fb819 | 200 | /* We can end up with dereferencing constant pointers. |
047fdd47 | 201 | Just bail out in this case. */ |
f85fb819 | 202 | if (TREE_CODE (ptr) == INTEGER_CST) |
047fdd47 | 203 | return true; |
204 | ||
dd277d48 | 205 | /* If we do not have useful points-to information for this pointer |
206 | we cannot disambiguate anything else. */ | |
207 | pi = SSA_NAME_PTR_INFO (ptr); | |
208 | if (!pi) | |
2fd0b5dc | 209 | return true; |
210 | ||
8bb76364 | 211 | /* If the decl can be used as a restrict tag and we have a restrict |
212 | pointer and that pointers points-to set doesn't contain this decl | |
213 | then they can't alias. */ | |
214 | if (DECL_RESTRICTED_P (decl) | |
215 | && TYPE_RESTRICT (TREE_TYPE (ptr)) | |
216 | && pi->pt.vars_contains_restrict) | |
217 | return bitmap_bit_p (pi->pt.vars, DECL_UID (decl)); | |
218 | ||
dd277d48 | 219 | return pt_solution_includes (&pi->pt, decl); |
2fd0b5dc | 220 | } |
4ee9c684 | 221 | |
2a3ebafa | 222 | /* Return true if dereferenced PTR1 and PTR2 may alias. |
223 | The caller is responsible for applying TBAA to see if accesses | |
224 | through PTR1 and PTR2 may conflict at all. */ | |
4ee9c684 | 225 | |
dd277d48 | 226 | static bool |
227 | ptr_derefs_may_alias_p (tree ptr1, tree ptr2) | |
4ee9c684 | 228 | { |
dd277d48 | 229 | struct ptr_info_def *pi1, *pi2; |
4ee9c684 | 230 | |
f85fb819 | 231 | gcc_assert ((TREE_CODE (ptr1) == SSA_NAME |
232 | || TREE_CODE (ptr1) == ADDR_EXPR | |
233 | || TREE_CODE (ptr1) == INTEGER_CST) | |
234 | && (TREE_CODE (ptr2) == SSA_NAME | |
235 | || TREE_CODE (ptr2) == ADDR_EXPR | |
236 | || TREE_CODE (ptr2) == INTEGER_CST)); | |
237 | ||
047fdd47 | 238 | /* ADDR_EXPR pointers either just offset another pointer or directly |
239 | specify the pointed-to set. */ | |
240 | if (TREE_CODE (ptr1) == ADDR_EXPR) | |
241 | { | |
242 | tree base = get_base_address (TREE_OPERAND (ptr1, 0)); | |
243 | if (base | |
244 | && INDIRECT_REF_P (base)) | |
245 | ptr1 = TREE_OPERAND (base, 0); | |
246 | else if (base | |
247 | && SSA_VAR_P (base)) | |
248 | return ptr_deref_may_alias_decl_p (ptr2, base); | |
249 | else | |
250 | return true; | |
251 | } | |
252 | if (TREE_CODE (ptr2) == ADDR_EXPR) | |
253 | { | |
254 | tree base = get_base_address (TREE_OPERAND (ptr2, 0)); | |
255 | if (base | |
256 | && INDIRECT_REF_P (base)) | |
257 | ptr2 = TREE_OPERAND (base, 0); | |
258 | else if (base | |
259 | && SSA_VAR_P (base)) | |
260 | return ptr_deref_may_alias_decl_p (ptr1, base); | |
261 | else | |
262 | return true; | |
263 | } | |
264 | ||
f85fb819 | 265 | /* We can end up with dereferencing constant pointers. |
047fdd47 | 266 | Just bail out in this case. */ |
f85fb819 | 267 | if (TREE_CODE (ptr1) == INTEGER_CST |
268 | || TREE_CODE (ptr2) == INTEGER_CST) | |
dd277d48 | 269 | return true; |
4ee9c684 | 270 | |
dd277d48 | 271 | /* We may end up with two empty points-to solutions for two same pointers. |
272 | In this case we still want to say both pointers alias, so shortcut | |
273 | that here. */ | |
274 | if (ptr1 == ptr2) | |
275 | return true; | |
81d08033 | 276 | |
dd277d48 | 277 | /* If we do not have useful points-to information for either pointer |
278 | we cannot disambiguate anything else. */ | |
279 | pi1 = SSA_NAME_PTR_INFO (ptr1); | |
280 | pi2 = SSA_NAME_PTR_INFO (ptr2); | |
281 | if (!pi1 || !pi2) | |
282 | return true; | |
81d08033 | 283 | |
1c1f1bc0 | 284 | /* If both pointers are restrict-qualified try to disambiguate |
285 | with restrict information. */ | |
286 | if (TYPE_RESTRICT (TREE_TYPE (ptr1)) | |
287 | && TYPE_RESTRICT (TREE_TYPE (ptr2)) | |
288 | && !pt_solutions_same_restrict_base (&pi1->pt, &pi2->pt)) | |
289 | return false; | |
290 | ||
2a3ebafa | 291 | /* ??? This does not use TBAA to prune decls from the intersection |
292 | that not both pointers may access. */ | |
dd277d48 | 293 | return pt_solutions_intersect (&pi1->pt, &pi2->pt); |
81d08033 | 294 | } |
295 | ||
047fdd47 | 296 | /* Return true if dereferencing PTR may alias *REF. |
297 | The caller is responsible for applying TBAA to see if PTR | |
298 | may access *REF at all. */ | |
299 | ||
300 | static bool | |
301 | ptr_deref_may_alias_ref_p_1 (tree ptr, ao_ref *ref) | |
302 | { | |
303 | tree base = ao_ref_base (ref); | |
304 | ||
305 | if (INDIRECT_REF_P (base)) | |
306 | return ptr_derefs_may_alias_p (ptr, TREE_OPERAND (base, 0)); | |
307 | else if (SSA_VAR_P (base)) | |
308 | return ptr_deref_may_alias_decl_p (ptr, base); | |
309 | ||
310 | return true; | |
311 | } | |
312 | ||
4ee9c684 | 313 | |
314 | /* Dump alias information on FILE. */ | |
315 | ||
316 | void | |
317 | dump_alias_info (FILE *file) | |
318 | { | |
319 | size_t i; | |
320 | const char *funcname | |
5135beeb | 321 | = lang_hooks.decl_printable_name (current_function_decl, 2); |
a55dc2cd | 322 | referenced_var_iterator rvi; |
323 | tree var; | |
4ee9c684 | 324 | |
dd277d48 | 325 | fprintf (file, "\n\nAlias information for %s\n\n", funcname); |
81d08033 | 326 | |
327 | fprintf (file, "Aliased symbols\n\n"); | |
48e1416a | 328 | |
a55dc2cd | 329 | FOR_EACH_REFERENCED_VAR (var, rvi) |
81d08033 | 330 | { |
81d08033 | 331 | if (may_be_aliased (var)) |
332 | dump_variable (file, var); | |
333 | } | |
334 | ||
7f81b5ee | 335 | fprintf (file, "\nCall clobber information\n"); |
336 | ||
337 | fprintf (file, "\nESCAPED"); | |
338 | dump_points_to_solution (file, &cfun->gimple_df->escaped); | |
339 | fprintf (file, "\nCALLUSED"); | |
340 | dump_points_to_solution (file, &cfun->gimple_df->callused); | |
341 | ||
342 | fprintf (file, "\n\nFlow-insensitive points-to information\n\n"); | |
81d08033 | 343 | |
81d08033 | 344 | for (i = 1; i < num_ssa_names; i++) |
345 | { | |
346 | tree ptr = ssa_name (i); | |
a48b1470 | 347 | struct ptr_info_def *pi; |
48e1416a | 348 | |
dd277d48 | 349 | if (ptr == NULL_TREE |
350 | || SSA_NAME_IN_FREE_LIST (ptr)) | |
a48b1470 | 351 | continue; |
352 | ||
353 | pi = SSA_NAME_PTR_INFO (ptr); | |
dd277d48 | 354 | if (pi) |
81d08033 | 355 | dump_points_to_info_for (file, ptr); |
356 | } | |
4ee9c684 | 357 | |
4ee9c684 | 358 | fprintf (file, "\n"); |
359 | } | |
360 | ||
361 | ||
362 | /* Dump alias information on stderr. */ | |
363 | ||
364 | void | |
365 | debug_alias_info (void) | |
366 | { | |
367 | dump_alias_info (stderr); | |
368 | } | |
369 | ||
370 | ||
786d45db | 371 | /* Return the alias information associated with pointer T. It creates a |
372 | new instance if none existed. */ | |
373 | ||
3276c83b | 374 | struct ptr_info_def * |
786d45db | 375 | get_ptr_info (tree t) |
376 | { | |
377 | struct ptr_info_def *pi; | |
378 | ||
8c0963c4 | 379 | gcc_assert (POINTER_TYPE_P (TREE_TYPE (t))); |
786d45db | 380 | |
381 | pi = SSA_NAME_PTR_INFO (t); | |
382 | if (pi == NULL) | |
383 | { | |
43959b95 | 384 | pi = GGC_CNEW (struct ptr_info_def); |
dd277d48 | 385 | pt_solution_reset (&pi->pt); |
786d45db | 386 | SSA_NAME_PTR_INFO (t) = pi; |
387 | } | |
388 | ||
389 | return pi; | |
390 | } | |
391 | ||
7f81b5ee | 392 | /* Dump the points-to set *PT into FILE. */ |
4ee9c684 | 393 | |
d793732c | 394 | void |
7f81b5ee | 395 | dump_points_to_solution (FILE *file, struct pt_solution *pt) |
4ee9c684 | 396 | { |
7f81b5ee | 397 | if (pt->anything) |
398 | fprintf (file, ", points-to anything"); | |
4ee9c684 | 399 | |
7f81b5ee | 400 | if (pt->nonlocal) |
401 | fprintf (file, ", points-to non-local"); | |
4ee9c684 | 402 | |
7f81b5ee | 403 | if (pt->escaped) |
404 | fprintf (file, ", points-to escaped"); | |
405 | ||
406 | if (pt->null) | |
407 | fprintf (file, ", points-to NULL"); | |
408 | ||
409 | if (pt->vars) | |
4ee9c684 | 410 | { |
7f81b5ee | 411 | fprintf (file, ", points-to vars: "); |
412 | dump_decl_set (file, pt->vars); | |
413 | if (pt->vars_contains_global) | |
414 | fprintf (file, " (includes global vars)"); | |
415 | } | |
416 | } | |
4ee9c684 | 417 | |
7f81b5ee | 418 | /* Dump points-to information for SSA_NAME PTR into FILE. */ |
4ee9c684 | 419 | |
7f81b5ee | 420 | void |
421 | dump_points_to_info_for (FILE *file, tree ptr) | |
422 | { | |
423 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr); | |
4ee9c684 | 424 | |
7f81b5ee | 425 | print_generic_expr (file, ptr, dump_flags); |
1e1a4c8c | 426 | |
7f81b5ee | 427 | if (pi) |
428 | dump_points_to_solution (file, &pi->pt); | |
429 | else | |
430 | fprintf (file, ", points-to anything"); | |
4ee9c684 | 431 | |
432 | fprintf (file, "\n"); | |
433 | } | |
434 | ||
435 | ||
d793732c | 436 | /* Dump points-to information for VAR into stderr. */ |
437 | ||
438 | void | |
439 | debug_points_to_info_for (tree var) | |
440 | { | |
441 | dump_points_to_info_for (stderr, var); | |
442 | } | |
443 | ||
3918bd18 | 444 | |
445 | /* Initializes the alias-oracle reference representation *R from REF. */ | |
446 | ||
447 | void | |
448 | ao_ref_init (ao_ref *r, tree ref) | |
449 | { | |
450 | r->ref = ref; | |
451 | r->base = NULL_TREE; | |
452 | r->offset = 0; | |
453 | r->size = -1; | |
454 | r->max_size = -1; | |
455 | r->ref_alias_set = -1; | |
456 | r->base_alias_set = -1; | |
457 | } | |
458 | ||
459 | /* Returns the base object of the memory reference *REF. */ | |
460 | ||
461 | tree | |
462 | ao_ref_base (ao_ref *ref) | |
463 | { | |
464 | if (ref->base) | |
465 | return ref->base; | |
466 | ref->base = get_ref_base_and_extent (ref->ref, &ref->offset, &ref->size, | |
467 | &ref->max_size); | |
468 | return ref->base; | |
469 | } | |
470 | ||
471 | /* Returns the base object alias set of the memory reference *REF. */ | |
472 | ||
473 | static alias_set_type ATTRIBUTE_UNUSED | |
474 | ao_ref_base_alias_set (ao_ref *ref) | |
475 | { | |
476 | if (ref->base_alias_set != -1) | |
477 | return ref->base_alias_set; | |
478 | ref->base_alias_set = get_alias_set (ao_ref_base (ref)); | |
479 | return ref->base_alias_set; | |
480 | } | |
481 | ||
482 | /* Returns the reference alias set of the memory reference *REF. */ | |
483 | ||
484 | alias_set_type | |
485 | ao_ref_alias_set (ao_ref *ref) | |
486 | { | |
487 | if (ref->ref_alias_set != -1) | |
488 | return ref->ref_alias_set; | |
489 | ref->ref_alias_set = get_alias_set (ref->ref); | |
490 | return ref->ref_alias_set; | |
491 | } | |
492 | ||
134899ac | 493 | /* Init an alias-oracle reference representation from a gimple pointer |
494 | PTR and a gimple size SIZE in bytes. If SIZE is NULL_TREE the the | |
495 | size is assumed to be unknown. The access is assumed to be only | |
496 | to or after of the pointer target, not before it. */ | |
497 | ||
498 | void | |
499 | ao_ref_init_from_ptr_and_size (ao_ref *ref, tree ptr, tree size) | |
500 | { | |
501 | HOST_WIDE_INT t1, t2; | |
502 | ref->ref = NULL_TREE; | |
503 | if (TREE_CODE (ptr) == ADDR_EXPR) | |
504 | ref->base = get_ref_base_and_extent (TREE_OPERAND (ptr, 0), | |
505 | &ref->offset, &t1, &t2); | |
506 | else | |
507 | { | |
508 | ref->base = build1 (INDIRECT_REF, char_type_node, ptr); | |
509 | ref->offset = 0; | |
510 | } | |
511 | if (size | |
512 | && host_integerp (size, 0) | |
513 | && TREE_INT_CST_LOW (size) * 8 / 8 == TREE_INT_CST_LOW (size)) | |
514 | ref->max_size = ref->size = TREE_INT_CST_LOW (size) * 8; | |
515 | else | |
516 | ref->max_size = ref->size = -1; | |
517 | ref->ref_alias_set = 0; | |
518 | ref->base_alias_set = 0; | |
519 | } | |
520 | ||
dd277d48 | 521 | /* Return 1 if TYPE1 and TYPE2 are to be considered equivalent for the |
522 | purpose of TBAA. Return 0 if they are distinct and -1 if we cannot | |
523 | decide. */ | |
d793732c | 524 | |
dd277d48 | 525 | static inline int |
526 | same_type_for_tbaa (tree type1, tree type2) | |
527 | { | |
528 | type1 = TYPE_MAIN_VARIANT (type1); | |
529 | type2 = TYPE_MAIN_VARIANT (type2); | |
4ee9c684 | 530 | |
dd277d48 | 531 | /* If we would have to do structural comparison bail out. */ |
532 | if (TYPE_STRUCTURAL_EQUALITY_P (type1) | |
533 | || TYPE_STRUCTURAL_EQUALITY_P (type2)) | |
534 | return -1; | |
535 | ||
536 | /* Compare the canonical types. */ | |
537 | if (TYPE_CANONICAL (type1) == TYPE_CANONICAL (type2)) | |
538 | return 1; | |
539 | ||
540 | /* ??? Array types are not properly unified in all cases as we have | |
541 | spurious changes in the index types for example. Removing this | |
542 | causes all sorts of problems with the Fortran frontend. */ | |
543 | if (TREE_CODE (type1) == ARRAY_TYPE | |
544 | && TREE_CODE (type2) == ARRAY_TYPE) | |
545 | return -1; | |
546 | ||
547 | /* The types are known to be not equal. */ | |
548 | return 0; | |
549 | } | |
550 | ||
551 | /* Determine if the two component references REF1 and REF2 which are | |
552 | based on access types TYPE1 and TYPE2 and of which at least one is based | |
553 | on an indirect reference may alias. */ | |
554 | ||
555 | static bool | |
a42ce2cc | 556 | aliasing_component_refs_p (tree ref1, tree type1, |
557 | HOST_WIDE_INT offset1, HOST_WIDE_INT max_size1, | |
558 | tree ref2, tree type2, | |
559 | HOST_WIDE_INT offset2, HOST_WIDE_INT max_size2) | |
dd277d48 | 560 | { |
561 | /* If one reference is a component references through pointers try to find a | |
562 | common base and apply offset based disambiguation. This handles | |
563 | for example | |
564 | struct A { int i; int j; } *q; | |
565 | struct B { struct A a; int k; } *p; | |
566 | disambiguating q->i and p->a.j. */ | |
567 | tree *refp; | |
568 | int same_p; | |
569 | ||
570 | /* Now search for the type1 in the access path of ref2. This | |
571 | would be a common base for doing offset based disambiguation on. */ | |
bc3c318e | 572 | refp = &ref2; |
dd277d48 | 573 | while (handled_component_p (*refp) |
574 | && same_type_for_tbaa (TREE_TYPE (*refp), type1) == 0) | |
575 | refp = &TREE_OPERAND (*refp, 0); | |
576 | same_p = same_type_for_tbaa (TREE_TYPE (*refp), type1); | |
577 | /* If we couldn't compare types we have to bail out. */ | |
578 | if (same_p == -1) | |
579 | return true; | |
580 | else if (same_p == 1) | |
581 | { | |
582 | HOST_WIDE_INT offadj, sztmp, msztmp; | |
583 | get_ref_base_and_extent (*refp, &offadj, &sztmp, &msztmp); | |
584 | offset2 -= offadj; | |
585 | return ranges_overlap_p (offset1, max_size1, offset2, max_size2); | |
586 | } | |
587 | /* If we didn't find a common base, try the other way around. */ | |
bc3c318e | 588 | refp = &ref1; |
dd277d48 | 589 | while (handled_component_p (*refp) |
590 | && same_type_for_tbaa (TREE_TYPE (*refp), type2) == 0) | |
591 | refp = &TREE_OPERAND (*refp, 0); | |
592 | same_p = same_type_for_tbaa (TREE_TYPE (*refp), type2); | |
593 | /* If we couldn't compare types we have to bail out. */ | |
594 | if (same_p == -1) | |
595 | return true; | |
596 | else if (same_p == 1) | |
597 | { | |
598 | HOST_WIDE_INT offadj, sztmp, msztmp; | |
599 | get_ref_base_and_extent (*refp, &offadj, &sztmp, &msztmp); | |
600 | offset1 -= offadj; | |
601 | return ranges_overlap_p (offset1, max_size1, offset2, max_size2); | |
602 | } | |
a42ce2cc | 603 | |
604 | /* We haven't found any common base to apply offset-based disambiguation. | |
605 | There are two cases: | |
606 | 1. The base access types have the same alias set. This can happen | |
607 | in Ada when a function with an unconstrained parameter passed by | |
608 | reference is called on a constrained object and inlined: the types | |
609 | have the same alias set but aren't equivalent. The references may | |
610 | alias in this case. | |
611 | 2. The base access types don't have the same alias set, i.e. one set | |
612 | is a subset of the other. We have proved that B1 is not in the | |
613 | access path B2.path and that B2 is not in the access path B1.path | |
614 | so the references may not alias. */ | |
615 | return get_alias_set (type1) == get_alias_set (type2); | |
dd277d48 | 616 | } |
617 | ||
618 | /* Return true if two memory references based on the variables BASE1 | |
077ad5ad | 619 | and BASE2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and |
620 | [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. */ | |
dd277d48 | 621 | |
622 | static bool | |
623 | decl_refs_may_alias_p (tree base1, | |
624 | HOST_WIDE_INT offset1, HOST_WIDE_INT max_size1, | |
625 | tree base2, | |
626 | HOST_WIDE_INT offset2, HOST_WIDE_INT max_size2) | |
4ee9c684 | 627 | { |
dd277d48 | 628 | gcc_assert (SSA_VAR_P (base1) && SSA_VAR_P (base2)); |
4ee9c684 | 629 | |
dd277d48 | 630 | /* If both references are based on different variables, they cannot alias. */ |
631 | if (!operand_equal_p (base1, base2, 0)) | |
632 | return false; | |
4ee9c684 | 633 | |
dd277d48 | 634 | /* If both references are based on the same variable, they cannot alias if |
635 | the accesses do not overlap. */ | |
636 | return ranges_overlap_p (offset1, max_size1, offset2, max_size2); | |
637 | } | |
638 | ||
639 | /* Return true if an indirect reference based on *PTR1 constrained | |
077ad5ad | 640 | to [OFFSET1, OFFSET1 + MAX_SIZE1) may alias a variable based on BASE2 |
641 | constrained to [OFFSET2, OFFSET2 + MAX_SIZE2). *PTR1 and BASE2 have | |
dd277d48 | 642 | the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1 |
643 | in which case they are computed on-demand. REF1 and REF2 | |
644 | if non-NULL are the complete memory reference trees. */ | |
645 | ||
646 | static bool | |
647 | indirect_ref_may_alias_decl_p (tree ref1, tree ptr1, | |
648 | HOST_WIDE_INT offset1, HOST_WIDE_INT max_size1, | |
649 | alias_set_type base1_alias_set, | |
650 | tree ref2, tree base2, | |
651 | HOST_WIDE_INT offset2, HOST_WIDE_INT max_size2, | |
652 | alias_set_type base2_alias_set) | |
653 | { | |
654 | /* If only one reference is based on a variable, they cannot alias if | |
655 | the pointer access is beyond the extent of the variable access. | |
656 | (the pointer base cannot validly point to an offset less than zero | |
657 | of the variable). | |
658 | They also cannot alias if the pointer may not point to the decl. */ | |
659 | if (max_size2 != -1 | |
660 | && !ranges_overlap_p (offset1, max_size1, 0, offset2 + max_size2)) | |
661 | return false; | |
662 | if (!ptr_deref_may_alias_decl_p (ptr1, base2)) | |
663 | return false; | |
664 | ||
665 | /* Disambiguations that rely on strict aliasing rules follow. */ | |
666 | if (!flag_strict_aliasing) | |
667 | return true; | |
668 | ||
669 | /* If the alias set for a pointer access is zero all bets are off. */ | |
670 | if (base1_alias_set == -1) | |
671 | base1_alias_set = get_deref_alias_set (ptr1); | |
672 | if (base1_alias_set == 0) | |
673 | return true; | |
674 | if (base2_alias_set == -1) | |
675 | base2_alias_set = get_alias_set (base2); | |
676 | ||
677 | /* If both references are through the same type, they do not alias | |
678 | if the accesses do not overlap. This does extra disambiguation | |
679 | for mixed/pointer accesses but requires strict aliasing. */ | |
680 | if (same_type_for_tbaa (TREE_TYPE (TREE_TYPE (ptr1)), | |
681 | TREE_TYPE (base2)) == 1) | |
682 | return ranges_overlap_p (offset1, max_size1, offset2, max_size2); | |
683 | ||
684 | /* The only way to access a variable is through a pointer dereference | |
685 | of the same alias set or a subset of it. */ | |
686 | if (base1_alias_set != base2_alias_set | |
687 | && !alias_set_subset_of (base1_alias_set, base2_alias_set)) | |
688 | return false; | |
689 | ||
690 | /* Do access-path based disambiguation. */ | |
691 | if (ref1 && ref2 | |
692 | && handled_component_p (ref1) | |
693 | && handled_component_p (ref2)) | |
a42ce2cc | 694 | return aliasing_component_refs_p (ref1, TREE_TYPE (TREE_TYPE (ptr1)), |
695 | offset1, max_size1, | |
696 | ref2, TREE_TYPE (base2), | |
697 | offset2, max_size2); | |
dd277d48 | 698 | |
699 | return true; | |
700 | } | |
701 | ||
702 | /* Return true if two indirect references based on *PTR1 | |
077ad5ad | 703 | and *PTR2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and |
704 | [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. *PTR1 and *PTR2 have | |
dd277d48 | 705 | the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1 |
706 | in which case they are computed on-demand. REF1 and REF2 | |
707 | if non-NULL are the complete memory reference trees. */ | |
708 | ||
709 | static bool | |
710 | indirect_refs_may_alias_p (tree ref1, tree ptr1, | |
711 | HOST_WIDE_INT offset1, HOST_WIDE_INT max_size1, | |
712 | alias_set_type base1_alias_set, | |
713 | tree ref2, tree ptr2, | |
714 | HOST_WIDE_INT offset2, HOST_WIDE_INT max_size2, | |
715 | alias_set_type base2_alias_set) | |
716 | { | |
717 | /* If both bases are based on pointers they cannot alias if they may not | |
718 | point to the same memory object or if they point to the same object | |
719 | and the accesses do not overlap. */ | |
720 | if (operand_equal_p (ptr1, ptr2, 0)) | |
721 | return ranges_overlap_p (offset1, max_size1, offset2, max_size2); | |
722 | if (!ptr_derefs_may_alias_p (ptr1, ptr2)) | |
723 | return false; | |
724 | ||
725 | /* Disambiguations that rely on strict aliasing rules follow. */ | |
726 | if (!flag_strict_aliasing) | |
727 | return true; | |
728 | ||
729 | /* If the alias set for a pointer access is zero all bets are off. */ | |
730 | if (base1_alias_set == -1) | |
731 | base1_alias_set = get_deref_alias_set (ptr1); | |
732 | if (base1_alias_set == 0) | |
733 | return true; | |
734 | if (base2_alias_set == -1) | |
735 | base2_alias_set = get_deref_alias_set (ptr2); | |
736 | if (base2_alias_set == 0) | |
737 | return true; | |
738 | ||
739 | /* If both references are through the same type, they do not alias | |
740 | if the accesses do not overlap. This does extra disambiguation | |
741 | for mixed/pointer accesses but requires strict aliasing. */ | |
742 | if (same_type_for_tbaa (TREE_TYPE (TREE_TYPE (ptr1)), | |
743 | TREE_TYPE (TREE_TYPE (ptr2))) == 1) | |
744 | return ranges_overlap_p (offset1, max_size1, offset2, max_size2); | |
745 | ||
746 | /* Do type-based disambiguation. */ | |
747 | if (base1_alias_set != base2_alias_set | |
748 | && !alias_sets_conflict_p (base1_alias_set, base2_alias_set)) | |
749 | return false; | |
750 | ||
751 | /* Do access-path based disambiguation. */ | |
752 | if (ref1 && ref2 | |
753 | && handled_component_p (ref1) | |
754 | && handled_component_p (ref2)) | |
a42ce2cc | 755 | return aliasing_component_refs_p (ref1, TREE_TYPE (TREE_TYPE (ptr1)), |
756 | offset1, max_size1, | |
757 | ref2, TREE_TYPE (TREE_TYPE (ptr2)), | |
758 | offset2, max_size2); | |
dd277d48 | 759 | |
760 | return true; | |
761 | } | |
762 | ||
763 | /* Return true, if the two memory references REF1 and REF2 may alias. */ | |
764 | ||
3a443843 | 765 | bool |
3918bd18 | 766 | refs_may_alias_p_1 (ao_ref *ref1, ao_ref *ref2, bool tbaa_p) |
dd277d48 | 767 | { |
768 | tree base1, base2; | |
769 | HOST_WIDE_INT offset1 = 0, offset2 = 0; | |
dd277d48 | 770 | HOST_WIDE_INT max_size1 = -1, max_size2 = -1; |
771 | bool var1_p, var2_p, ind1_p, ind2_p; | |
2a3ebafa | 772 | alias_set_type set; |
dd277d48 | 773 | |
3918bd18 | 774 | gcc_assert ((!ref1->ref |
775 | || SSA_VAR_P (ref1->ref) | |
776 | || handled_component_p (ref1->ref) | |
777 | || INDIRECT_REF_P (ref1->ref) | |
119147d1 | 778 | || TREE_CODE (ref1->ref) == TARGET_MEM_REF |
779 | || TREE_CODE (ref1->ref) == CONST_DECL) | |
3918bd18 | 780 | && (!ref2->ref |
781 | || SSA_VAR_P (ref2->ref) | |
782 | || handled_component_p (ref2->ref) | |
783 | || INDIRECT_REF_P (ref2->ref) | |
119147d1 | 784 | || TREE_CODE (ref2->ref) == TARGET_MEM_REF |
785 | || TREE_CODE (ref2->ref) == CONST_DECL)); | |
dd277d48 | 786 | |
dd277d48 | 787 | /* Decompose the references into their base objects and the access. */ |
3918bd18 | 788 | base1 = ao_ref_base (ref1); |
789 | offset1 = ref1->offset; | |
3918bd18 | 790 | max_size1 = ref1->max_size; |
791 | base2 = ao_ref_base (ref2); | |
792 | offset2 = ref2->offset; | |
3918bd18 | 793 | max_size2 = ref2->max_size; |
dd277d48 | 794 | |
795 | /* We can end up with registers or constants as bases for example from | |
796 | *D.1663_44 = VIEW_CONVERT_EXPR<struct DB_LSN>(__tmp$B0F64_59); | |
797 | which is seen as a struct copy. */ | |
798 | if (TREE_CODE (base1) == SSA_NAME | |
dd277d48 | 799 | || TREE_CODE (base2) == SSA_NAME |
119147d1 | 800 | || TREE_CODE (base1) == CONST_DECL |
801 | || TREE_CODE (base2) == CONST_DECL | |
9b973aa6 | 802 | || is_gimple_min_invariant (base1) |
f85fb819 | 803 | || is_gimple_min_invariant (base2)) |
dd277d48 | 804 | return false; |
805 | ||
ceefbccc | 806 | /* We can end up refering to code via function decls. As we likely |
807 | do not properly track code aliases conservatively bail out. */ | |
808 | if (TREE_CODE (base1) == FUNCTION_DECL | |
809 | || TREE_CODE (base2) == FUNCTION_DECL) | |
810 | return true; | |
811 | ||
090a8c65 | 812 | /* Defer to simple offset based disambiguation if we have |
813 | references based on two decls. Do this before defering to | |
814 | TBAA to handle must-alias cases in conformance with the | |
815 | GCC extension of allowing type-punning through unions. */ | |
dd277d48 | 816 | var1_p = SSA_VAR_P (base1); |
817 | var2_p = SSA_VAR_P (base2); | |
dd277d48 | 818 | if (var1_p && var2_p) |
819 | return decl_refs_may_alias_p (base1, offset1, max_size1, | |
820 | base2, offset2, max_size2); | |
090a8c65 | 821 | |
822 | /* First defer to TBAA if possible. */ | |
2a3ebafa | 823 | if (tbaa_p |
824 | && flag_strict_aliasing | |
3918bd18 | 825 | && !alias_sets_conflict_p (ao_ref_alias_set (ref1), |
826 | ao_ref_alias_set (ref2))) | |
090a8c65 | 827 | return false; |
828 | ||
829 | /* If one reference is a TARGET_MEM_REF weird things are allowed. Still | |
830 | TBAA disambiguation based on the access type is possible, so bail | |
831 | out only after that check. */ | |
3918bd18 | 832 | if ((ref1->ref && TREE_CODE (ref1->ref) == TARGET_MEM_REF) |
833 | || (ref2->ref && TREE_CODE (ref2->ref) == TARGET_MEM_REF)) | |
090a8c65 | 834 | return true; |
835 | ||
836 | /* Dispatch to the pointer-vs-decl or pointer-vs-pointer disambiguators. */ | |
837 | ind1_p = INDIRECT_REF_P (base1); | |
838 | ind2_p = INDIRECT_REF_P (base2); | |
2a3ebafa | 839 | set = tbaa_p ? -1 : 0; |
090a8c65 | 840 | if (var1_p && ind2_p) |
3918bd18 | 841 | return indirect_ref_may_alias_decl_p (ref2->ref, TREE_OPERAND (base2, 0), |
2a3ebafa | 842 | offset2, max_size2, set, |
3918bd18 | 843 | ref1->ref, base1, |
2a3ebafa | 844 | offset1, max_size1, set); |
dd277d48 | 845 | else if (ind1_p && var2_p) |
3918bd18 | 846 | return indirect_ref_may_alias_decl_p (ref1->ref, TREE_OPERAND (base1, 0), |
2a3ebafa | 847 | offset1, max_size1, set, |
3918bd18 | 848 | ref2->ref, base2, |
2a3ebafa | 849 | offset2, max_size2, set); |
dd277d48 | 850 | else if (ind1_p && ind2_p) |
3918bd18 | 851 | return indirect_refs_may_alias_p (ref1->ref, TREE_OPERAND (base1, 0), |
2a3ebafa | 852 | offset1, max_size1, set, |
3918bd18 | 853 | ref2->ref, TREE_OPERAND (base2, 0), |
2a3ebafa | 854 | offset2, max_size2, set); |
dd277d48 | 855 | |
856 | gcc_unreachable (); | |
857 | } | |
858 | ||
859 | bool | |
860 | refs_may_alias_p (tree ref1, tree ref2) | |
861 | { | |
3918bd18 | 862 | ao_ref r1, r2; |
863 | bool res; | |
864 | ao_ref_init (&r1, ref1); | |
865 | ao_ref_init (&r2, ref2); | |
866 | res = refs_may_alias_p_1 (&r1, &r2, true); | |
dd277d48 | 867 | if (res) |
868 | ++alias_stats.refs_may_alias_p_may_alias; | |
869 | else | |
870 | ++alias_stats.refs_may_alias_p_no_alias; | |
871 | return res; | |
872 | } | |
873 | ||
2a3ebafa | 874 | /* Returns true if there is a anti-dependence for the STORE that |
875 | executes after the LOAD. */ | |
876 | ||
877 | bool | |
878 | refs_anti_dependent_p (tree load, tree store) | |
879 | { | |
3918bd18 | 880 | ao_ref r1, r2; |
881 | ao_ref_init (&r1, load); | |
882 | ao_ref_init (&r2, store); | |
883 | return refs_may_alias_p_1 (&r1, &r2, false); | |
2a3ebafa | 884 | } |
885 | ||
886 | /* Returns true if there is a output dependence for the stores | |
887 | STORE1 and STORE2. */ | |
888 | ||
889 | bool | |
890 | refs_output_dependent_p (tree store1, tree store2) | |
891 | { | |
3918bd18 | 892 | ao_ref r1, r2; |
893 | ao_ref_init (&r1, store1); | |
894 | ao_ref_init (&r2, store2); | |
895 | return refs_may_alias_p_1 (&r1, &r2, false); | |
2a3ebafa | 896 | } |
dd277d48 | 897 | |
898 | /* If the call CALL may use the memory reference REF return true, | |
899 | otherwise return false. */ | |
900 | ||
901 | static bool | |
134899ac | 902 | ref_maybe_used_by_call_p_1 (gimple call, ao_ref *ref) |
dd277d48 | 903 | { |
047fdd47 | 904 | tree base, callee; |
dd277d48 | 905 | unsigned i; |
906 | int flags = gimple_call_flags (call); | |
907 | ||
908 | /* Const functions without a static chain do not implicitly use memory. */ | |
909 | if (!gimple_call_chain (call) | |
910 | && (flags & (ECF_CONST|ECF_NOVOPS))) | |
911 | goto process_args; | |
912 | ||
134899ac | 913 | base = ao_ref_base (ref); |
917f08fa | 914 | if (!base) |
dd277d48 | 915 | return true; |
916 | ||
09347e88 | 917 | /* If the reference is based on a decl that is not aliased the call |
918 | cannot possibly use it. */ | |
919 | if (DECL_P (base) | |
920 | && !may_be_aliased (base) | |
7f7f16d4 | 921 | /* But local statics can be used through recursion. */ |
922 | && !is_global_var (base)) | |
09347e88 | 923 | goto process_args; |
924 | ||
047fdd47 | 925 | callee = gimple_call_fndecl (call); |
926 | ||
927 | /* Handle those builtin functions explicitly that do not act as | |
928 | escape points. See tree-ssa-structalias.c:find_func_aliases | |
929 | for the list of builtins we might need to handle here. */ | |
930 | if (callee != NULL_TREE | |
931 | && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL) | |
932 | switch (DECL_FUNCTION_CODE (callee)) | |
933 | { | |
934 | /* All the following functions clobber memory pointed to by | |
935 | their first argument. */ | |
936 | case BUILT_IN_STRCPY: | |
937 | case BUILT_IN_STRNCPY: | |
047fdd47 | 938 | case BUILT_IN_MEMCPY: |
939 | case BUILT_IN_MEMMOVE: | |
940 | case BUILT_IN_MEMPCPY: | |
941 | case BUILT_IN_STPCPY: | |
942 | case BUILT_IN_STPNCPY: | |
943 | case BUILT_IN_STRCAT: | |
944 | case BUILT_IN_STRNCAT: | |
945 | { | |
134899ac | 946 | ao_ref dref; |
947 | tree size = NULL_TREE; | |
948 | if (gimple_call_num_args (call) == 3) | |
949 | size = gimple_call_arg (call, 2); | |
950 | ao_ref_init_from_ptr_and_size (&dref, | |
951 | gimple_call_arg (call, 1), | |
952 | size); | |
953 | return refs_may_alias_p_1 (&dref, ref, false); | |
047fdd47 | 954 | } |
119147d1 | 955 | case BUILT_IN_BCOPY: |
956 | { | |
957 | ao_ref dref; | |
958 | tree size = gimple_call_arg (call, 2); | |
959 | ao_ref_init_from_ptr_and_size (&dref, | |
960 | gimple_call_arg (call, 0), | |
961 | size); | |
962 | return refs_may_alias_p_1 (&dref, ref, false); | |
963 | } | |
09d9c774 | 964 | /* The following builtins do not read from memory. */ |
965 | case BUILT_IN_FREE: | |
966 | case BUILT_IN_MEMSET: | |
967 | case BUILT_IN_FREXP: | |
968 | case BUILT_IN_FREXPF: | |
969 | case BUILT_IN_FREXPL: | |
970 | case BUILT_IN_GAMMA_R: | |
971 | case BUILT_IN_GAMMAF_R: | |
972 | case BUILT_IN_GAMMAL_R: | |
973 | case BUILT_IN_LGAMMA_R: | |
974 | case BUILT_IN_LGAMMAF_R: | |
975 | case BUILT_IN_LGAMMAL_R: | |
976 | case BUILT_IN_MODF: | |
977 | case BUILT_IN_MODFF: | |
978 | case BUILT_IN_MODFL: | |
979 | case BUILT_IN_REMQUO: | |
980 | case BUILT_IN_REMQUOF: | |
981 | case BUILT_IN_REMQUOL: | |
982 | case BUILT_IN_SINCOS: | |
983 | case BUILT_IN_SINCOSF: | |
984 | case BUILT_IN_SINCOSL: | |
985 | return false; | |
986 | ||
047fdd47 | 987 | default: |
988 | /* Fallthru to general call handling. */; | |
989 | } | |
990 | ||
dd277d48 | 991 | /* Check if base is a global static variable that is not read |
992 | by the function. */ | |
993 | if (TREE_CODE (base) == VAR_DECL | |
994 | && TREE_STATIC (base) | |
995 | && !TREE_PUBLIC (base)) | |
4ee9c684 | 996 | { |
dd277d48 | 997 | bitmap not_read; |
998 | ||
999 | if (callee != NULL_TREE | |
1000 | && (not_read | |
1001 | = ipa_reference_get_not_read_global (cgraph_node (callee))) | |
1002 | && bitmap_bit_p (not_read, DECL_UID (base))) | |
1003 | goto process_args; | |
4ee9c684 | 1004 | } |
1005 | ||
dd277d48 | 1006 | /* If the base variable is call-used or call-clobbered then |
1007 | it may be used. */ | |
1008 | if (flags & (ECF_PURE|ECF_CONST|ECF_LOOPING_CONST_OR_PURE|ECF_NOVOPS)) | |
4ee9c684 | 1009 | { |
917f08fa | 1010 | if (DECL_P (base)) |
1011 | { | |
1012 | if (is_call_used (base)) | |
1013 | return true; | |
1014 | } | |
1015 | else if (INDIRECT_REF_P (base) | |
1016 | && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME) | |
1017 | { | |
1018 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0)); | |
1019 | if (!pi) | |
1020 | return true; | |
1021 | ||
1022 | if (pt_solution_includes_global (&pi->pt) | |
1023 | || pt_solutions_intersect (&cfun->gimple_df->callused, &pi->pt) | |
1024 | || pt_solutions_intersect (&cfun->gimple_df->escaped, &pi->pt)) | |
1025 | return true; | |
1026 | } | |
1027 | else | |
dd277d48 | 1028 | return true; |
1029 | } | |
1030 | else | |
1031 | { | |
917f08fa | 1032 | if (DECL_P (base)) |
1033 | { | |
1034 | if (is_call_clobbered (base)) | |
1035 | return true; | |
1036 | } | |
1037 | else if (INDIRECT_REF_P (base) | |
1038 | && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME) | |
1039 | { | |
1040 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0)); | |
1041 | if (!pi) | |
1042 | return true; | |
1043 | ||
1044 | if (pt_solution_includes_global (&pi->pt) | |
1045 | || pt_solutions_intersect (&cfun->gimple_df->escaped, &pi->pt)) | |
1046 | return true; | |
1047 | } | |
1048 | else | |
dd277d48 | 1049 | return true; |
1050 | } | |
1051 | ||
1052 | /* Inspect call arguments for passed-by-value aliases. */ | |
1053 | process_args: | |
1054 | for (i = 0; i < gimple_call_num_args (call); ++i) | |
1055 | { | |
1056 | tree op = gimple_call_arg (call, i); | |
1057 | ||
dd277d48 | 1058 | if (TREE_CODE (op) == WITH_SIZE_EXPR) |
1059 | op = TREE_OPERAND (op, 0); | |
4ee9c684 | 1060 | |
dd277d48 | 1061 | if (TREE_CODE (op) != SSA_NAME |
134899ac | 1062 | && !is_gimple_min_invariant (op)) |
1063 | { | |
1064 | ao_ref r; | |
1065 | ao_ref_init (&r, op); | |
1066 | if (refs_may_alias_p_1 (&r, ref, true)) | |
1067 | return true; | |
1068 | } | |
4ee9c684 | 1069 | } |
1070 | ||
dd277d48 | 1071 | return false; |
1072 | } | |
1073 | ||
1074 | static bool | |
1075 | ref_maybe_used_by_call_p (gimple call, tree ref) | |
1076 | { | |
134899ac | 1077 | ao_ref r; |
1078 | bool res; | |
1079 | ao_ref_init (&r, ref); | |
1080 | res = ref_maybe_used_by_call_p_1 (call, &r); | |
dd277d48 | 1081 | if (res) |
1082 | ++alias_stats.ref_maybe_used_by_call_p_may_alias; | |
1083 | else | |
1084 | ++alias_stats.ref_maybe_used_by_call_p_no_alias; | |
1085 | return res; | |
4ee9c684 | 1086 | } |
1087 | ||
1088 | ||
dd277d48 | 1089 | /* If the statement STMT may use the memory reference REF return |
1090 | true, otherwise return false. */ | |
4ee9c684 | 1091 | |
dd277d48 | 1092 | bool |
1093 | ref_maybe_used_by_stmt_p (gimple stmt, tree ref) | |
4ee9c684 | 1094 | { |
dd277d48 | 1095 | if (is_gimple_assign (stmt)) |
1096 | { | |
1097 | tree rhs; | |
1098 | ||
1099 | /* All memory assign statements are single. */ | |
1100 | if (!gimple_assign_single_p (stmt)) | |
1101 | return false; | |
1102 | ||
1103 | rhs = gimple_assign_rhs1 (stmt); | |
1104 | if (is_gimple_reg (rhs) | |
1105 | || is_gimple_min_invariant (rhs) | |
1106 | || gimple_assign_rhs_code (stmt) == CONSTRUCTOR) | |
1107 | return false; | |
1108 | ||
1109 | return refs_may_alias_p (rhs, ref); | |
1110 | } | |
1111 | else if (is_gimple_call (stmt)) | |
1112 | return ref_maybe_used_by_call_p (stmt, ref); | |
1113 | ||
1114 | return true; | |
4ee9c684 | 1115 | } |
1116 | ||
dd277d48 | 1117 | /* If the call in statement CALL may clobber the memory reference REF |
1118 | return true, otherwise return false. */ | |
4ee9c684 | 1119 | |
dd277d48 | 1120 | static bool |
3918bd18 | 1121 | call_may_clobber_ref_p_1 (gimple call, ao_ref *ref) |
4ee9c684 | 1122 | { |
7f7f16d4 | 1123 | tree base; |
047fdd47 | 1124 | tree callee; |
dd277d48 | 1125 | |
1126 | /* If the call is pure or const it cannot clobber anything. */ | |
1127 | if (gimple_call_flags (call) | |
1128 | & (ECF_PURE|ECF_CONST|ECF_LOOPING_CONST_OR_PURE|ECF_NOVOPS)) | |
1129 | return false; | |
1130 | ||
3918bd18 | 1131 | base = ao_ref_base (ref); |
dd277d48 | 1132 | if (!base) |
1133 | return true; | |
1134 | ||
1135 | if (TREE_CODE (base) == SSA_NAME | |
1136 | || CONSTANT_CLASS_P (base)) | |
1137 | return false; | |
1138 | ||
09347e88 | 1139 | /* If the reference is based on a decl that is not aliased the call |
1140 | cannot possibly clobber it. */ | |
1141 | if (DECL_P (base) | |
1142 | && !may_be_aliased (base) | |
7f7f16d4 | 1143 | /* But local non-readonly statics can be modified through recursion |
1144 | or the call may implement a threading barrier which we must | |
1145 | treat as may-def. */ | |
09347e88 | 1146 | && (TREE_READONLY (base) |
7f7f16d4 | 1147 | || !is_global_var (base))) |
09347e88 | 1148 | return false; |
1149 | ||
047fdd47 | 1150 | callee = gimple_call_fndecl (call); |
1151 | ||
1152 | /* Handle those builtin functions explicitly that do not act as | |
1153 | escape points. See tree-ssa-structalias.c:find_func_aliases | |
1154 | for the list of builtins we might need to handle here. */ | |
1155 | if (callee != NULL_TREE | |
1156 | && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL) | |
1157 | switch (DECL_FUNCTION_CODE (callee)) | |
1158 | { | |
1159 | /* All the following functions clobber memory pointed to by | |
1160 | their first argument. */ | |
1161 | case BUILT_IN_STRCPY: | |
1162 | case BUILT_IN_STRNCPY: | |
047fdd47 | 1163 | case BUILT_IN_MEMCPY: |
1164 | case BUILT_IN_MEMMOVE: | |
1165 | case BUILT_IN_MEMPCPY: | |
1166 | case BUILT_IN_STPCPY: | |
1167 | case BUILT_IN_STPNCPY: | |
1168 | case BUILT_IN_STRCAT: | |
1169 | case BUILT_IN_STRNCAT: | |
134899ac | 1170 | case BUILT_IN_MEMSET: |
047fdd47 | 1171 | { |
134899ac | 1172 | ao_ref dref; |
1173 | tree size = NULL_TREE; | |
1174 | if (gimple_call_num_args (call) == 3) | |
1175 | size = gimple_call_arg (call, 2); | |
1176 | ao_ref_init_from_ptr_and_size (&dref, | |
1177 | gimple_call_arg (call, 0), | |
1178 | size); | |
1179 | return refs_may_alias_p_1 (&dref, ref, false); | |
047fdd47 | 1180 | } |
119147d1 | 1181 | case BUILT_IN_BCOPY: |
1182 | { | |
1183 | ao_ref dref; | |
1184 | tree size = gimple_call_arg (call, 2); | |
1185 | ao_ref_init_from_ptr_and_size (&dref, | |
1186 | gimple_call_arg (call, 1), | |
1187 | size); | |
1188 | return refs_may_alias_p_1 (&dref, ref, false); | |
1189 | } | |
047fdd47 | 1190 | /* Freeing memory kills the pointed-to memory. More importantly |
1191 | the call has to serve as a barrier for moving loads and stores | |
134899ac | 1192 | across it. */ |
047fdd47 | 1193 | case BUILT_IN_FREE: |
047fdd47 | 1194 | { |
1195 | tree ptr = gimple_call_arg (call, 0); | |
1196 | return ptr_deref_may_alias_ref_p_1 (ptr, ref); | |
1197 | } | |
047fdd47 | 1198 | case BUILT_IN_GAMMA_R: |
1199 | case BUILT_IN_GAMMAF_R: | |
1200 | case BUILT_IN_GAMMAL_R: | |
1201 | case BUILT_IN_LGAMMA_R: | |
1202 | case BUILT_IN_LGAMMAF_R: | |
1203 | case BUILT_IN_LGAMMAL_R: | |
09d9c774 | 1204 | { |
1205 | tree out = gimple_call_arg (call, 1); | |
1206 | if (ptr_deref_may_alias_ref_p_1 (out, ref)) | |
1207 | return true; | |
1208 | if (flag_errno_math) | |
1209 | break; | |
1210 | return false; | |
1211 | } | |
1212 | case BUILT_IN_FREXP: | |
1213 | case BUILT_IN_FREXPF: | |
1214 | case BUILT_IN_FREXPL: | |
047fdd47 | 1215 | case BUILT_IN_MODF: |
1216 | case BUILT_IN_MODFF: | |
1217 | case BUILT_IN_MODFL: | |
1218 | { | |
1219 | tree out = gimple_call_arg (call, 1); | |
1220 | return ptr_deref_may_alias_ref_p_1 (out, ref); | |
1221 | } | |
1222 | case BUILT_IN_REMQUO: | |
1223 | case BUILT_IN_REMQUOF: | |
1224 | case BUILT_IN_REMQUOL: | |
1225 | { | |
1226 | tree out = gimple_call_arg (call, 2); | |
09d9c774 | 1227 | if (ptr_deref_may_alias_ref_p_1 (out, ref)) |
1228 | return true; | |
1229 | if (flag_errno_math) | |
1230 | break; | |
1231 | return false; | |
047fdd47 | 1232 | } |
1233 | case BUILT_IN_SINCOS: | |
1234 | case BUILT_IN_SINCOSF: | |
1235 | case BUILT_IN_SINCOSL: | |
1236 | { | |
1237 | tree sin = gimple_call_arg (call, 1); | |
1238 | tree cos = gimple_call_arg (call, 2); | |
1239 | return (ptr_deref_may_alias_ref_p_1 (sin, ref) | |
1240 | || ptr_deref_may_alias_ref_p_1 (cos, ref)); | |
1241 | } | |
1242 | default: | |
1243 | /* Fallthru to general call handling. */; | |
1244 | } | |
1245 | ||
dd277d48 | 1246 | /* Check if base is a global static variable that is not written |
1247 | by the function. */ | |
047fdd47 | 1248 | if (callee != NULL_TREE |
1249 | && TREE_CODE (base) == VAR_DECL | |
dd277d48 | 1250 | && TREE_STATIC (base) |
1251 | && !TREE_PUBLIC (base)) | |
4ee9c684 | 1252 | { |
dd277d48 | 1253 | bitmap not_written; |
0eaf9bd7 | 1254 | |
047fdd47 | 1255 | if ((not_written |
1256 | = ipa_reference_get_not_written_global (cgraph_node (callee))) | |
dd277d48 | 1257 | && bitmap_bit_p (not_written, DECL_UID (base))) |
1258 | return false; | |
4ee9c684 | 1259 | } |
4ee9c684 | 1260 | |
dd277d48 | 1261 | if (DECL_P (base)) |
1262 | return is_call_clobbered (base); | |
917f08fa | 1263 | else if (INDIRECT_REF_P (base) |
1264 | && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME) | |
1265 | { | |
1266 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0)); | |
1267 | if (!pi) | |
1268 | return true; | |
1269 | ||
1270 | return (pt_solution_includes_global (&pi->pt) | |
1271 | || pt_solutions_intersect (&cfun->gimple_df->escaped, &pi->pt)); | |
1272 | } | |
4ee9c684 | 1273 | |
dd277d48 | 1274 | return true; |
1275 | } | |
4ee9c684 | 1276 | |
3918bd18 | 1277 | static bool ATTRIBUTE_UNUSED |
dd277d48 | 1278 | call_may_clobber_ref_p (gimple call, tree ref) |
4ee9c684 | 1279 | { |
3918bd18 | 1280 | bool res; |
1281 | ao_ref r; | |
1282 | ao_ref_init (&r, ref); | |
1283 | res = call_may_clobber_ref_p_1 (call, &r); | |
dd277d48 | 1284 | if (res) |
1285 | ++alias_stats.call_may_clobber_ref_p_may_alias; | |
1286 | else | |
1287 | ++alias_stats.call_may_clobber_ref_p_no_alias; | |
1288 | return res; | |
4ee9c684 | 1289 | } |
94e6573f | 1290 | |
dd277d48 | 1291 | |
1292 | /* If the statement STMT may clobber the memory reference REF return true, | |
1293 | otherwise return false. */ | |
94e6573f | 1294 | |
1295 | bool | |
3918bd18 | 1296 | stmt_may_clobber_ref_p_1 (gimple stmt, ao_ref *ref) |
94e6573f | 1297 | { |
dd277d48 | 1298 | if (is_gimple_call (stmt)) |
1299 | { | |
1300 | tree lhs = gimple_call_lhs (stmt); | |
1301 | if (lhs | |
3918bd18 | 1302 | && !is_gimple_reg (lhs)) |
1303 | { | |
1304 | ao_ref r; | |
1305 | ao_ref_init (&r, lhs); | |
1306 | if (refs_may_alias_p_1 (ref, &r, true)) | |
1307 | return true; | |
1308 | } | |
94e6573f | 1309 | |
3918bd18 | 1310 | return call_may_clobber_ref_p_1 (stmt, ref); |
dd277d48 | 1311 | } |
1312 | else if (is_gimple_assign (stmt)) | |
3918bd18 | 1313 | { |
1314 | ao_ref r; | |
1315 | ao_ref_init (&r, gimple_assign_lhs (stmt)); | |
1316 | return refs_may_alias_p_1 (ref, &r, true); | |
1317 | } | |
dd277d48 | 1318 | else if (gimple_code (stmt) == GIMPLE_ASM) |
94e6573f | 1319 | return true; |
1320 | ||
6329636b | 1321 | return false; |
94e6573f | 1322 | } |
2be14d8b | 1323 | |
3918bd18 | 1324 | bool |
1325 | stmt_may_clobber_ref_p (gimple stmt, tree ref) | |
1326 | { | |
1327 | ao_ref r; | |
1328 | ao_ref_init (&r, ref); | |
1329 | return stmt_may_clobber_ref_p_1 (stmt, &r); | |
1330 | } | |
1331 | ||
1332 | ||
dd277d48 | 1333 | /* Walk the virtual use-def chain of VUSE until hitting the virtual operand |
1334 | TARGET or a statement clobbering the memory reference REF in which | |
1335 | case false is returned. The walk starts with VUSE, one argument of PHI. */ | |
1336 | ||
1337 | static bool | |
3918bd18 | 1338 | maybe_skip_until (gimple phi, tree target, ao_ref *ref, |
1339 | tree vuse, bitmap *visited) | |
ac926412 | 1340 | { |
dd277d48 | 1341 | if (!*visited) |
1342 | *visited = BITMAP_ALLOC (NULL); | |
ac926412 | 1343 | |
dd277d48 | 1344 | bitmap_set_bit (*visited, SSA_NAME_VERSION (PHI_RESULT (phi))); |
1345 | ||
1346 | /* Walk until we hit the target. */ | |
1347 | while (vuse != target) | |
ac926412 | 1348 | { |
dd277d48 | 1349 | gimple def_stmt = SSA_NAME_DEF_STMT (vuse); |
1350 | /* Recurse for PHI nodes. */ | |
1351 | if (gimple_code (def_stmt) == GIMPLE_PHI) | |
1352 | { | |
1353 | /* An already visited PHI node ends the walk successfully. */ | |
1354 | if (bitmap_bit_p (*visited, SSA_NAME_VERSION (PHI_RESULT (def_stmt)))) | |
1355 | return true; | |
1356 | vuse = get_continuation_for_phi (def_stmt, ref, visited); | |
1357 | if (!vuse) | |
1358 | return false; | |
1359 | continue; | |
1360 | } | |
1361 | /* A clobbering statement or the end of the IL ends it failing. */ | |
1362 | else if (gimple_nop_p (def_stmt) | |
3918bd18 | 1363 | || stmt_may_clobber_ref_p_1 (def_stmt, ref)) |
dd277d48 | 1364 | return false; |
1365 | vuse = gimple_vuse (def_stmt); | |
ac926412 | 1366 | } |
dd277d48 | 1367 | return true; |
1368 | } | |
ac926412 | 1369 | |
dd277d48 | 1370 | /* Starting from a PHI node for the virtual operand of the memory reference |
1371 | REF find a continuation virtual operand that allows to continue walking | |
1372 | statements dominating PHI skipping only statements that cannot possibly | |
1373 | clobber REF. Returns NULL_TREE if no suitable virtual operand can | |
1374 | be found. */ | |
1375 | ||
7814d418 | 1376 | tree |
3918bd18 | 1377 | get_continuation_for_phi (gimple phi, ao_ref *ref, bitmap *visited) |
dd277d48 | 1378 | { |
1379 | unsigned nargs = gimple_phi_num_args (phi); | |
1380 | ||
1381 | /* Through a single-argument PHI we can simply look through. */ | |
1382 | if (nargs == 1) | |
1383 | return PHI_ARG_DEF (phi, 0); | |
1384 | ||
1385 | /* For two arguments try to skip non-aliasing code until we hit | |
1386 | the phi argument definition that dominates the other one. */ | |
1387 | if (nargs == 2) | |
ac926412 | 1388 | { |
dd277d48 | 1389 | tree arg0 = PHI_ARG_DEF (phi, 0); |
1390 | tree arg1 = PHI_ARG_DEF (phi, 1); | |
1391 | gimple def0 = SSA_NAME_DEF_STMT (arg0); | |
1392 | gimple def1 = SSA_NAME_DEF_STMT (arg1); | |
7814d418 | 1393 | tree common_vuse; |
dd277d48 | 1394 | |
1395 | if (arg0 == arg1) | |
1396 | return arg0; | |
1397 | else if (gimple_nop_p (def0) | |
1398 | || (!gimple_nop_p (def1) | |
1399 | && dominated_by_p (CDI_DOMINATORS, | |
1400 | gimple_bb (def1), gimple_bb (def0)))) | |
1401 | { | |
1402 | if (maybe_skip_until (phi, arg0, ref, arg1, visited)) | |
1403 | return arg0; | |
1404 | } | |
1405 | else if (gimple_nop_p (def1) | |
1406 | || dominated_by_p (CDI_DOMINATORS, | |
1407 | gimple_bb (def0), gimple_bb (def1))) | |
1408 | { | |
1409 | if (maybe_skip_until (phi, arg1, ref, arg0, visited)) | |
1410 | return arg1; | |
1411 | } | |
7814d418 | 1412 | /* Special case of a diamond: |
1413 | MEM_1 = ... | |
1414 | goto (cond) ? L1 : L2 | |
1415 | L1: store1 = ... #MEM_2 = vuse(MEM_1) | |
1416 | goto L3 | |
1417 | L2: store2 = ... #MEM_3 = vuse(MEM_1) | |
1418 | L3: MEM_4 = PHI<MEM_2, MEM_3> | |
1419 | We were called with the PHI at L3, MEM_2 and MEM_3 don't | |
1420 | dominate each other, but still we can easily skip this PHI node | |
1421 | if we recognize that the vuse MEM operand is the same for both, | |
1422 | and that we can skip both statements (they don't clobber us). | |
1423 | This is still linear. Don't use maybe_skip_until, that might | |
1424 | potentially be slow. */ | |
1425 | else if ((common_vuse = gimple_vuse (def0)) | |
1426 | && common_vuse == gimple_vuse (def1)) | |
1427 | { | |
1428 | if (!stmt_may_clobber_ref_p_1 (def0, ref) | |
1429 | && !stmt_may_clobber_ref_p_1 (def1, ref)) | |
1430 | return common_vuse; | |
1431 | } | |
ac926412 | 1432 | } |
dd277d48 | 1433 | |
1434 | return NULL_TREE; | |
ac926412 | 1435 | } |
516849c7 | 1436 | |
dd277d48 | 1437 | /* Based on the memory reference REF and its virtual use VUSE call |
1438 | WALKER for each virtual use that is equivalent to VUSE, including VUSE | |
1439 | itself. That is, for each virtual use for which its defining statement | |
1440 | does not clobber REF. | |
e683de6d | 1441 | |
dd277d48 | 1442 | WALKER is called with REF, the current virtual use and DATA. If |
1443 | WALKER returns non-NULL the walk stops and its result is returned. | |
1444 | At the end of a non-successful walk NULL is returned. | |
3857274c | 1445 | |
d8021dea | 1446 | TRANSLATE if non-NULL is called with a pointer to REF, the virtual |
1447 | use which definition is a statement that may clobber REF and DATA. | |
1448 | If TRANSLATE returns (void *)-1 the walk stops and NULL is returned. | |
1449 | If TRANSLATE returns non-NULL the walk stops and its result is returned. | |
1450 | If TRANSLATE returns NULL the walk continues and TRANSLATE is supposed | |
1451 | to adjust REF and *DATA to make that valid. | |
1452 | ||
dd277d48 | 1453 | TODO: Cache the vector of equivalent vuses per ref, vuse pair. */ |
1454 | ||
1455 | void * | |
3918bd18 | 1456 | walk_non_aliased_vuses (ao_ref *ref, tree vuse, |
1457 | void *(*walker)(ao_ref *, tree, void *), | |
1458 | void *(*translate)(ao_ref *, tree, void *), void *data) | |
3857274c | 1459 | { |
dd277d48 | 1460 | bitmap visited = NULL; |
1461 | void *res; | |
1462 | ||
02c74b9b | 1463 | timevar_push (TV_ALIAS_STMT_WALK); |
1464 | ||
dd277d48 | 1465 | do |
1466 | { | |
1467 | gimple def_stmt; | |
3857274c | 1468 | |
02c74b9b | 1469 | /* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */ |
dd277d48 | 1470 | res = (*walker) (ref, vuse, data); |
1471 | if (res) | |
1472 | break; | |
3857274c | 1473 | |
dd277d48 | 1474 | def_stmt = SSA_NAME_DEF_STMT (vuse); |
1475 | if (gimple_nop_p (def_stmt)) | |
1476 | break; | |
1477 | else if (gimple_code (def_stmt) == GIMPLE_PHI) | |
1478 | vuse = get_continuation_for_phi (def_stmt, ref, &visited); | |
1479 | else | |
1480 | { | |
3918bd18 | 1481 | if (stmt_may_clobber_ref_p_1 (def_stmt, ref)) |
d8021dea | 1482 | { |
1483 | if (!translate) | |
1484 | break; | |
3918bd18 | 1485 | res = (*translate) (ref, vuse, data); |
d8021dea | 1486 | /* Failed lookup and translation. */ |
1487 | if (res == (void *)-1) | |
1488 | { | |
1489 | res = NULL; | |
1490 | break; | |
1491 | } | |
1492 | /* Lookup succeeded. */ | |
1493 | else if (res != NULL) | |
1494 | break; | |
1495 | /* Translation succeeded, continue walking. */ | |
1496 | } | |
dd277d48 | 1497 | vuse = gimple_vuse (def_stmt); |
1498 | } | |
1499 | } | |
1500 | while (vuse); | |
ac926412 | 1501 | |
dd277d48 | 1502 | if (visited) |
1503 | BITMAP_FREE (visited); | |
ac926412 | 1504 | |
02c74b9b | 1505 | timevar_pop (TV_ALIAS_STMT_WALK); |
1506 | ||
dd277d48 | 1507 | return res; |
3857274c | 1508 | } |
1509 | ||
604eef2c | 1510 | |
dd277d48 | 1511 | /* Based on the memory reference REF call WALKER for each vdef which |
1512 | defining statement may clobber REF, starting with VDEF. If REF | |
1513 | is NULL_TREE, each defining statement is visited. | |
1514 | ||
1515 | WALKER is called with REF, the current vdef and DATA. If WALKER | |
1516 | returns true the walk is stopped, otherwise it continues. | |
1517 | ||
1518 | At PHI nodes walk_aliased_vdefs forks into one walk for reach | |
1519 | PHI argument (but only one walk continues on merge points), the | |
1520 | return value is true if any of the walks was successful. | |
1521 | ||
1522 | The function returns the number of statements walked. */ | |
604eef2c | 1523 | |
1524 | static unsigned int | |
1daead67 | 1525 | walk_aliased_vdefs_1 (ao_ref *ref, tree vdef, |
1526 | bool (*walker)(ao_ref *, tree, void *), void *data, | |
dd277d48 | 1527 | bitmap *visited, unsigned int cnt) |
604eef2c | 1528 | { |
dd277d48 | 1529 | do |
1530 | { | |
1531 | gimple def_stmt = SSA_NAME_DEF_STMT (vdef); | |
604eef2c | 1532 | |
dd277d48 | 1533 | if (*visited |
1534 | && !bitmap_set_bit (*visited, SSA_NAME_VERSION (vdef))) | |
1535 | return cnt; | |
1536 | ||
1537 | if (gimple_nop_p (def_stmt)) | |
1538 | return cnt; | |
1539 | else if (gimple_code (def_stmt) == GIMPLE_PHI) | |
1540 | { | |
1541 | unsigned i; | |
1542 | if (!*visited) | |
1543 | *visited = BITMAP_ALLOC (NULL); | |
1544 | for (i = 0; i < gimple_phi_num_args (def_stmt); ++i) | |
1545 | cnt += walk_aliased_vdefs_1 (ref, gimple_phi_arg_def (def_stmt, i), | |
1546 | walker, data, visited, 0); | |
1547 | return cnt; | |
1548 | } | |
1549 | ||
02c74b9b | 1550 | /* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */ |
dd277d48 | 1551 | cnt++; |
1552 | if ((!ref | |
1daead67 | 1553 | || stmt_may_clobber_ref_p_1 (def_stmt, ref)) |
dd277d48 | 1554 | && (*walker) (ref, vdef, data)) |
1555 | return cnt; | |
1556 | ||
1557 | vdef = gimple_vuse (def_stmt); | |
1558 | } | |
1559 | while (1); | |
604eef2c | 1560 | } |
1561 | ||
dd277d48 | 1562 | unsigned int |
1daead67 | 1563 | walk_aliased_vdefs (ao_ref *ref, tree vdef, |
1564 | bool (*walker)(ao_ref *, tree, void *), void *data, | |
dd277d48 | 1565 | bitmap *visited) |
df3f0669 | 1566 | { |
dd277d48 | 1567 | bitmap local_visited = NULL; |
1568 | unsigned int ret; | |
1569 | ||
02c74b9b | 1570 | timevar_push (TV_ALIAS_STMT_WALK); |
1571 | ||
dd277d48 | 1572 | ret = walk_aliased_vdefs_1 (ref, vdef, walker, data, |
1573 | visited ? visited : &local_visited, 0); | |
1574 | if (local_visited) | |
1575 | BITMAP_FREE (local_visited); | |
1576 | ||
02c74b9b | 1577 | timevar_pop (TV_ALIAS_STMT_WALK); |
1578 | ||
dd277d48 | 1579 | return ret; |
1580 | } | |
1581 |