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9ae8ffe7 | 1 | /* Alias analysis for GNU C |
818ab71a | 2 | Copyright (C) 1997-2016 Free Software Foundation, Inc. |
9ae8ffe7 JL |
3 | Contributed by John Carr (jfc@mit.edu). |
4 | ||
1322177d | 5 | This file is part of GCC. |
9ae8ffe7 | 6 | |
1322177d LB |
7 | GCC is free software; you can redistribute it and/or modify it under |
8 | the terms of the GNU General Public License as published by the Free | |
9dcd6f09 | 9 | Software Foundation; either version 3, or (at your option) any later |
1322177d | 10 | version. |
9ae8ffe7 | 11 | |
1322177d LB |
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
9ae8ffe7 JL |
16 | |
17 | You should have received a copy of the GNU General Public License | |
9dcd6f09 NC |
18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
9ae8ffe7 JL |
20 | |
21 | #include "config.h" | |
670ee920 | 22 | #include "system.h" |
4977bab6 | 23 | #include "coretypes.h" |
c7131fb2 | 24 | #include "backend.h" |
957060b5 AM |
25 | #include "target.h" |
26 | #include "rtl.h" | |
c7131fb2 AM |
27 | #include "tree.h" |
28 | #include "gimple.h" | |
c7131fb2 | 29 | #include "df.h" |
957060b5 AM |
30 | #include "tm_p.h" |
31 | #include "gimple-ssa.h" | |
957060b5 | 32 | #include "emit-rtl.h" |
40e23961 | 33 | #include "alias.h" |
40e23961 | 34 | #include "fold-const.h" |
d8a2d370 | 35 | #include "varasm.h" |
eab5c70a | 36 | #include "cselib.h" |
d23c55c2 | 37 | #include "langhooks.h" |
60393bbc | 38 | #include "cfganal.h" |
403837b4 | 39 | #include "rtl-iter.h" |
54363f8a | 40 | #include "cgraph.h" |
ea900239 DB |
41 | |
42 | /* The aliasing API provided here solves related but different problems: | |
43 | ||
c22cacf3 | 44 | Say there exists (in c) |
ea900239 DB |
45 | |
46 | struct X { | |
47 | struct Y y1; | |
48 | struct Z z2; | |
49 | } x1, *px1, *px2; | |
50 | ||
51 | struct Y y2, *py; | |
52 | struct Z z2, *pz; | |
53 | ||
54 | ||
308a3fe2 | 55 | py = &x1.y1; |
ea900239 DB |
56 | px2 = &x1; |
57 | ||
58 | Consider the four questions: | |
59 | ||
60 | Can a store to x1 interfere with px2->y1? | |
61 | Can a store to x1 interfere with px2->z2? | |
ea900239 DB |
62 | Can a store to x1 change the value pointed to by with py? |
63 | Can a store to x1 change the value pointed to by with pz? | |
64 | ||
65 | The answer to these questions can be yes, yes, yes, and maybe. | |
66 | ||
67 | The first two questions can be answered with a simple examination | |
68 | of the type system. If structure X contains a field of type Y then | |
073a8998 | 69 | a store through a pointer to an X can overwrite any field that is |
ea900239 DB |
70 | contained (recursively) in an X (unless we know that px1 != px2). |
71 | ||
308a3fe2 DS |
72 | The last two questions can be solved in the same way as the first |
73 | two questions but this is too conservative. The observation is | |
74 | that in some cases we can know which (if any) fields are addressed | |
75 | and if those addresses are used in bad ways. This analysis may be | |
76 | language specific. In C, arbitrary operations may be applied to | |
77 | pointers. However, there is some indication that this may be too | |
78 | conservative for some C++ types. | |
ea900239 DB |
79 | |
80 | The pass ipa-type-escape does this analysis for the types whose | |
c22cacf3 | 81 | instances do not escape across the compilation boundary. |
ea900239 DB |
82 | |
83 | Historically in GCC, these two problems were combined and a single | |
308a3fe2 | 84 | data structure that was used to represent the solution to these |
ea900239 | 85 | problems. We now have two similar but different data structures, |
308a3fe2 DS |
86 | The data structure to solve the last two questions is similar to |
87 | the first, but does not contain the fields whose address are never | |
88 | taken. For types that do escape the compilation unit, the data | |
89 | structures will have identical information. | |
ea900239 | 90 | */ |
3932261a MM |
91 | |
92 | /* The alias sets assigned to MEMs assist the back-end in determining | |
93 | which MEMs can alias which other MEMs. In general, two MEMs in | |
ac3d9668 RK |
94 | different alias sets cannot alias each other, with one important |
95 | exception. Consider something like: | |
3932261a | 96 | |
01d28c3f | 97 | struct S { int i; double d; }; |
3932261a MM |
98 | |
99 | a store to an `S' can alias something of either type `int' or type | |
100 | `double'. (However, a store to an `int' cannot alias a `double' | |
101 | and vice versa.) We indicate this via a tree structure that looks | |
102 | like: | |
c22cacf3 MS |
103 | struct S |
104 | / \ | |
3932261a | 105 | / \ |
c22cacf3 MS |
106 | |/_ _\| |
107 | int double | |
3932261a | 108 | |
ac3d9668 RK |
109 | (The arrows are directed and point downwards.) |
110 | In this situation we say the alias set for `struct S' is the | |
111 | `superset' and that those for `int' and `double' are `subsets'. | |
112 | ||
3bdf5ad1 RK |
113 | To see whether two alias sets can point to the same memory, we must |
114 | see if either alias set is a subset of the other. We need not trace | |
95bd1dd7 | 115 | past immediate descendants, however, since we propagate all |
3bdf5ad1 | 116 | grandchildren up one level. |
3932261a MM |
117 | |
118 | Alias set zero is implicitly a superset of all other alias sets. | |
119 | However, this is no actual entry for alias set zero. It is an | |
120 | error to attempt to explicitly construct a subset of zero. */ | |
121 | ||
e0702244 | 122 | struct alias_set_hash : int_hash <int, INT_MIN, INT_MIN + 1> {}; |
de144fb2 | 123 | |
02ced957 | 124 | struct GTY(()) alias_set_entry { |
3932261a | 125 | /* The alias set number, as stored in MEM_ALIAS_SET. */ |
4862826d | 126 | alias_set_type alias_set; |
3932261a MM |
127 | |
128 | /* The children of the alias set. These are not just the immediate | |
95bd1dd7 | 129 | children, but, in fact, all descendants. So, if we have: |
3932261a | 130 | |
ca7fd9cd | 131 | struct T { struct S s; float f; } |
3932261a MM |
132 | |
133 | continuing our example above, the children here will be all of | |
134 | `int', `double', `float', and `struct S'. */ | |
fb5c464a | 135 | hash_map<alias_set_hash, int> *children; |
6e042ef4 JH |
136 | |
137 | /* Nonzero if would have a child of zero: this effectively makes this | |
138 | alias set the same as alias set zero. */ | |
139 | bool has_zero_child; | |
140 | /* Nonzero if alias set corresponds to pointer type itself (i.e. not to | |
141 | aggregate contaiing pointer. | |
142 | This is used for a special case where we need an universal pointer type | |
143 | compatible with all other pointer types. */ | |
144 | bool is_pointer; | |
145 | /* Nonzero if is_pointer or if one of childs have has_pointer set. */ | |
146 | bool has_pointer; | |
b604074c | 147 | }; |
9ae8ffe7 | 148 | |
ed7a4b4b | 149 | static int rtx_equal_for_memref_p (const_rtx, const_rtx); |
4682ae04 | 150 | static int memrefs_conflict_p (int, rtx, int, rtx, HOST_WIDE_INT); |
7bc980e1 | 151 | static void record_set (rtx, const_rtx, void *); |
ef4bddc2 RS |
152 | static int base_alias_check (rtx, rtx, rtx, rtx, machine_mode, |
153 | machine_mode); | |
4682ae04 | 154 | static rtx find_base_value (rtx); |
4f588890 | 155 | static int mems_in_disjoint_alias_sets_p (const_rtx, const_rtx); |
02ced957 | 156 | static alias_set_entry *get_alias_set_entry (alias_set_type); |
4682ae04 | 157 | static tree decl_for_component_ref (tree); |
bd280792 | 158 | static int write_dependence_p (const_rtx, |
ef4bddc2 | 159 | const_rtx, machine_mode, rtx, |
bd280792 | 160 | bool, bool, bool); |
4682ae04 | 161 | |
aa317c97 | 162 | static void memory_modified_1 (rtx, const_rtx, void *); |
9ae8ffe7 | 163 | |
3ecf9d13 JH |
164 | /* Query statistics for the different low-level disambiguators. |
165 | A high-level query may trigger multiple of them. */ | |
166 | ||
167 | static struct { | |
168 | unsigned long long num_alias_zero; | |
169 | unsigned long long num_same_alias_set; | |
170 | unsigned long long num_same_objects; | |
171 | unsigned long long num_volatile; | |
172 | unsigned long long num_dag; | |
6e042ef4 | 173 | unsigned long long num_universal; |
3ecf9d13 JH |
174 | unsigned long long num_disambiguated; |
175 | } alias_stats; | |
176 | ||
177 | ||
9ae8ffe7 JL |
178 | /* Set up all info needed to perform alias analysis on memory references. */ |
179 | ||
d4b60170 | 180 | /* Returns the size in bytes of the mode of X. */ |
9ae8ffe7 JL |
181 | #define SIZE_FOR_MODE(X) (GET_MODE_SIZE (GET_MODE (X))) |
182 | ||
ea64ef27 | 183 | /* Cap the number of passes we make over the insns propagating alias |
131db6b8 SB |
184 | information through set chains. |
185 | ??? 10 is a completely arbitrary choice. This should be based on the | |
186 | maximum loop depth in the CFG, but we do not have this information | |
187 | available (even if current_loops _is_ available). */ | |
ea64ef27 | 188 | #define MAX_ALIAS_LOOP_PASSES 10 |
ca7fd9cd | 189 | |
9ae8ffe7 JL |
190 | /* reg_base_value[N] gives an address to which register N is related. |
191 | If all sets after the first add or subtract to the current value | |
192 | or otherwise modify it so it does not point to a different top level | |
193 | object, reg_base_value[N] is equal to the address part of the source | |
2a2c8203 JC |
194 | of the first set. |
195 | ||
196 | A base address can be an ADDRESS, SYMBOL_REF, or LABEL_REF. ADDRESS | |
9fc37b2b | 197 | expressions represent three types of base: |
b3b5ad95 | 198 | |
9fc37b2b RS |
199 | 1. incoming arguments. There is just one ADDRESS to represent all |
200 | arguments, since we do not know at this level whether accesses | |
201 | based on different arguments can alias. The ADDRESS has id 0. | |
b3b5ad95 | 202 | |
9fc37b2b RS |
203 | 2. stack_pointer_rtx, frame_pointer_rtx, hard_frame_pointer_rtx |
204 | (if distinct from frame_pointer_rtx) and arg_pointer_rtx. | |
205 | Each of these rtxes has a separate ADDRESS associated with it, | |
206 | each with a negative id. | |
207 | ||
208 | GCC is (and is required to be) precise in which register it | |
209 | chooses to access a particular region of stack. We can therefore | |
210 | assume that accesses based on one of these rtxes do not alias | |
211 | accesses based on another of these rtxes. | |
212 | ||
213 | 3. bases that are derived from malloc()ed memory (REG_NOALIAS). | |
214 | Each such piece of memory has a separate ADDRESS associated | |
215 | with it, each with an id greater than 0. | |
216 | ||
217 | Accesses based on one ADDRESS do not alias accesses based on other | |
218 | ADDRESSes. Accesses based on ADDRESSes in groups (2) and (3) do not | |
219 | alias globals either; the ADDRESSes have Pmode to indicate this. | |
220 | The ADDRESS in group (1) _may_ alias globals; it has VOIDmode to | |
221 | indicate this. */ | |
2a2c8203 | 222 | |
9771b263 | 223 | static GTY(()) vec<rtx, va_gc> *reg_base_value; |
ac606739 | 224 | static rtx *new_reg_base_value; |
c582d54a | 225 | |
9fc37b2b RS |
226 | /* The single VOIDmode ADDRESS that represents all argument bases. |
227 | It has id 0. */ | |
228 | static GTY(()) rtx arg_base_value; | |
229 | ||
230 | /* Used to allocate unique ids to each REG_NOALIAS ADDRESS. */ | |
231 | static int unique_id; | |
232 | ||
c582d54a JH |
233 | /* We preserve the copy of old array around to avoid amount of garbage |
234 | produced. About 8% of garbage produced were attributed to this | |
235 | array. */ | |
9771b263 | 236 | static GTY((deletable)) vec<rtx, va_gc> *old_reg_base_value; |
d4b60170 | 237 | |
9e412ca3 RS |
238 | /* Values of XINT (address, 0) of Pmode ADDRESS rtxes for special |
239 | registers. */ | |
240 | #define UNIQUE_BASE_VALUE_SP -1 | |
241 | #define UNIQUE_BASE_VALUE_ARGP -2 | |
242 | #define UNIQUE_BASE_VALUE_FP -3 | |
243 | #define UNIQUE_BASE_VALUE_HFP -4 | |
244 | ||
7bf84454 RS |
245 | #define static_reg_base_value \ |
246 | (this_target_rtl->x_static_reg_base_value) | |
bf1660a6 | 247 | |
9771b263 DN |
248 | #define REG_BASE_VALUE(X) \ |
249 | (REGNO (X) < vec_safe_length (reg_base_value) \ | |
250 | ? (*reg_base_value)[REGNO (X)] : 0) | |
9ae8ffe7 | 251 | |
c13e8210 | 252 | /* Vector indexed by N giving the initial (unchanging) value known for |
9ff3c7ca | 253 | pseudo-register N. This vector is initialized in init_alias_analysis, |
bb1acb3e | 254 | and does not change until end_alias_analysis is called. */ |
9771b263 | 255 | static GTY(()) vec<rtx, va_gc> *reg_known_value; |
9ae8ffe7 JL |
256 | |
257 | /* Vector recording for each reg_known_value whether it is due to a | |
258 | REG_EQUIV note. Future passes (viz., reload) may replace the | |
259 | pseudo with the equivalent expression and so we account for the | |
ac3d9668 RK |
260 | dependences that would be introduced if that happens. |
261 | ||
262 | The REG_EQUIV notes created in assign_parms may mention the arg | |
263 | pointer, and there are explicit insns in the RTL that modify the | |
264 | arg pointer. Thus we must ensure that such insns don't get | |
265 | scheduled across each other because that would invalidate the | |
266 | REG_EQUIV notes. One could argue that the REG_EQUIV notes are | |
267 | wrong, but solving the problem in the scheduler will likely give | |
268 | better code, so we do it here. */ | |
9ff3c7ca | 269 | static sbitmap reg_known_equiv_p; |
9ae8ffe7 | 270 | |
2a2c8203 JC |
271 | /* True when scanning insns from the start of the rtl to the |
272 | NOTE_INSN_FUNCTION_BEG note. */ | |
83bbd9b6 | 273 | static bool copying_arguments; |
9ae8ffe7 | 274 | |
1a5640b4 | 275 | |
3932261a | 276 | /* The splay-tree used to store the various alias set entries. */ |
02ced957 | 277 | static GTY (()) vec<alias_set_entry *, va_gc> *alias_sets; |
ac3d9668 | 278 | \f |
55b34b5f RG |
279 | /* Build a decomposed reference object for querying the alias-oracle |
280 | from the MEM rtx and store it in *REF. | |
281 | Returns false if MEM is not suitable for the alias-oracle. */ | |
282 | ||
283 | static bool | |
284 | ao_ref_from_mem (ao_ref *ref, const_rtx mem) | |
285 | { | |
286 | tree expr = MEM_EXPR (mem); | |
287 | tree base; | |
288 | ||
289 | if (!expr) | |
290 | return false; | |
291 | ||
292 | ao_ref_init (ref, expr); | |
293 | ||
294 | /* Get the base of the reference and see if we have to reject or | |
295 | adjust it. */ | |
296 | base = ao_ref_base (ref); | |
297 | if (base == NULL_TREE) | |
298 | return false; | |
299 | ||
ef7a9fb8 RB |
300 | /* The tree oracle doesn't like bases that are neither decls |
301 | nor indirect references of SSA names. */ | |
302 | if (!(DECL_P (base) | |
303 | || (TREE_CODE (base) == MEM_REF | |
304 | && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME) | |
305 | || (TREE_CODE (base) == TARGET_MEM_REF | |
306 | && TREE_CODE (TMR_BASE (base)) == SSA_NAME))) | |
d15adbeb | 307 | return false; |
55b34b5f RG |
308 | |
309 | /* If this is a reference based on a partitioned decl replace the | |
ef7a9fb8 | 310 | base with a MEM_REF of the pointer representative we |
55b34b5f RG |
311 | created during stack slot partitioning. */ |
312 | if (TREE_CODE (base) == VAR_DECL | |
ef7a9fb8 | 313 | && ! is_global_var (base) |
55b34b5f RG |
314 | && cfun->gimple_df->decls_to_pointers != NULL) |
315 | { | |
39c8aaa4 | 316 | tree *namep = cfun->gimple_df->decls_to_pointers->get (base); |
55b34b5f | 317 | if (namep) |
39c8aaa4 | 318 | ref->base = build_simple_mem_ref (*namep); |
d15adbeb | 319 | } |
55b34b5f RG |
320 | |
321 | ref->ref_alias_set = MEM_ALIAS_SET (mem); | |
322 | ||
f68396a1 RG |
323 | /* If MEM_OFFSET or MEM_SIZE are unknown what we got from MEM_EXPR |
324 | is conservative, so trust it. */ | |
527210c4 | 325 | if (!MEM_OFFSET_KNOWN_P (mem) |
f5541398 | 326 | || !MEM_SIZE_KNOWN_P (mem)) |
f68396a1 | 327 | return true; |
366f945f | 328 | |
e8024441 RB |
329 | /* If MEM_OFFSET/MEM_SIZE get us outside of ref->offset/ref->max_size |
330 | drop ref->ref. */ | |
527210c4 | 331 | if (MEM_OFFSET (mem) < 0 |
e8024441 RB |
332 | || (ref->max_size != -1 |
333 | && ((MEM_OFFSET (mem) + MEM_SIZE (mem)) * BITS_PER_UNIT | |
334 | > ref->max_size))) | |
335 | ref->ref = NULL_TREE; | |
b0e96404 | 336 | |
e8024441 RB |
337 | /* Refine size and offset we got from analyzing MEM_EXPR by using |
338 | MEM_SIZE and MEM_OFFSET. */ | |
f68396a1 | 339 | |
527210c4 | 340 | ref->offset += MEM_OFFSET (mem) * BITS_PER_UNIT; |
f5541398 | 341 | ref->size = MEM_SIZE (mem) * BITS_PER_UNIT; |
b0e96404 RG |
342 | |
343 | /* The MEM may extend into adjacent fields, so adjust max_size if | |
344 | necessary. */ | |
345 | if (ref->max_size != -1 | |
346 | && ref->size > ref->max_size) | |
347 | ref->max_size = ref->size; | |
348 | ||
349 | /* If MEM_OFFSET and MEM_SIZE get us outside of the base object of | |
350 | the MEM_EXPR punt. This happens for STRICT_ALIGNMENT targets a lot. */ | |
351 | if (MEM_EXPR (mem) != get_spill_slot_decl (false) | |
352 | && (ref->offset < 0 | |
353 | || (DECL_P (ref->base) | |
807e902e KZ |
354 | && (DECL_SIZE (ref->base) == NULL_TREE |
355 | || TREE_CODE (DECL_SIZE (ref->base)) != INTEGER_CST | |
356 | || wi::ltu_p (wi::to_offset (DECL_SIZE (ref->base)), | |
357 | ref->offset + ref->size))))) | |
b0e96404 | 358 | return false; |
55b34b5f RG |
359 | |
360 | return true; | |
361 | } | |
362 | ||
363 | /* Query the alias-oracle on whether the two memory rtx X and MEM may | |
364 | alias. If TBAA_P is set also apply TBAA. Returns true if the | |
365 | two rtxen may alias, false otherwise. */ | |
366 | ||
367 | static bool | |
368 | rtx_refs_may_alias_p (const_rtx x, const_rtx mem, bool tbaa_p) | |
369 | { | |
370 | ao_ref ref1, ref2; | |
371 | ||
372 | if (!ao_ref_from_mem (&ref1, x) | |
373 | || !ao_ref_from_mem (&ref2, mem)) | |
374 | return true; | |
375 | ||
55e3bc4c RG |
376 | return refs_may_alias_p_1 (&ref1, &ref2, |
377 | tbaa_p | |
378 | && MEM_ALIAS_SET (x) != 0 | |
379 | && MEM_ALIAS_SET (mem) != 0); | |
55b34b5f RG |
380 | } |
381 | ||
3932261a MM |
382 | /* Returns a pointer to the alias set entry for ALIAS_SET, if there is |
383 | such an entry, or NULL otherwise. */ | |
384 | ||
02ced957 | 385 | static inline alias_set_entry * |
4862826d | 386 | get_alias_set_entry (alias_set_type alias_set) |
3932261a | 387 | { |
9771b263 | 388 | return (*alias_sets)[alias_set]; |
3932261a MM |
389 | } |
390 | ||
ac3d9668 RK |
391 | /* Returns nonzero if the alias sets for MEM1 and MEM2 are such that |
392 | the two MEMs cannot alias each other. */ | |
3932261a | 393 | |
9ddb66ca | 394 | static inline int |
4f588890 | 395 | mems_in_disjoint_alias_sets_p (const_rtx mem1, const_rtx mem2) |
3932261a | 396 | { |
598f8eca RB |
397 | return (flag_strict_aliasing |
398 | && ! alias_sets_conflict_p (MEM_ALIAS_SET (mem1), | |
399 | MEM_ALIAS_SET (mem2))); | |
1da68f56 | 400 | } |
3932261a | 401 | |
c58936b6 DB |
402 | /* Return true if the first alias set is a subset of the second. */ |
403 | ||
404 | bool | |
4862826d | 405 | alias_set_subset_of (alias_set_type set1, alias_set_type set2) |
c58936b6 | 406 | { |
02ced957 | 407 | alias_set_entry *ase2; |
c58936b6 | 408 | |
bd04cddf JH |
409 | /* Disable TBAA oracle with !flag_strict_aliasing. */ |
410 | if (!flag_strict_aliasing) | |
411 | return true; | |
412 | ||
c58936b6 DB |
413 | /* Everything is a subset of the "aliases everything" set. */ |
414 | if (set2 == 0) | |
415 | return true; | |
416 | ||
6e042ef4 JH |
417 | /* Check if set1 is a subset of set2. */ |
418 | ase2 = get_alias_set_entry (set2); | |
419 | if (ase2 != 0 | |
420 | && (ase2->has_zero_child | |
421 | || (ase2->children && ase2->children->get (set1)))) | |
c58936b6 | 422 | return true; |
6e042ef4 JH |
423 | |
424 | /* As a special case we consider alias set of "void *" to be both subset | |
425 | and superset of every alias set of a pointer. This extra symmetry does | |
426 | not matter for alias_sets_conflict_p but it makes aliasing_component_refs_p | |
427 | to return true on the following testcase: | |
428 | ||
429 | void *ptr; | |
430 | char **ptr2=(char **)&ptr; | |
431 | *ptr2 = ... | |
432 | ||
433 | Additionally if a set contains universal pointer, we consider every pointer | |
434 | to be a subset of it, but we do not represent this explicitely - doing so | |
435 | would require us to update transitive closure each time we introduce new | |
436 | pointer type. This makes aliasing_component_refs_p to return true | |
437 | on the following testcase: | |
438 | ||
439 | struct a {void *ptr;} | |
440 | char **ptr = (char **)&a.ptr; | |
441 | ptr = ... | |
442 | ||
443 | This makes void * truly universal pointer type. See pointer handling in | |
444 | get_alias_set for more details. */ | |
445 | if (ase2 && ase2->has_pointer) | |
446 | { | |
02ced957 | 447 | alias_set_entry *ase1 = get_alias_set_entry (set1); |
6e042ef4 JH |
448 | |
449 | if (ase1 && ase1->is_pointer) | |
450 | { | |
451 | alias_set_type voidptr_set = TYPE_ALIAS_SET (ptr_type_node); | |
452 | /* If one is ptr_type_node and other is pointer, then we consider | |
453 | them subset of each other. */ | |
454 | if (set1 == voidptr_set || set2 == voidptr_set) | |
455 | return true; | |
456 | /* If SET2 contains universal pointer's alias set, then we consdier | |
457 | every (non-universal) pointer. */ | |
458 | if (ase2->children && set1 != voidptr_set | |
459 | && ase2->children->get (voidptr_set)) | |
460 | return true; | |
461 | } | |
462 | } | |
c58936b6 DB |
463 | return false; |
464 | } | |
465 | ||
1da68f56 RK |
466 | /* Return 1 if the two specified alias sets may conflict. */ |
467 | ||
468 | int | |
4862826d | 469 | alias_sets_conflict_p (alias_set_type set1, alias_set_type set2) |
1da68f56 | 470 | { |
02ced957 TS |
471 | alias_set_entry *ase1; |
472 | alias_set_entry *ase2; | |
1da68f56 | 473 | |
836f7794 EB |
474 | /* The easy case. */ |
475 | if (alias_sets_must_conflict_p (set1, set2)) | |
1da68f56 | 476 | return 1; |
3932261a | 477 | |
3bdf5ad1 | 478 | /* See if the first alias set is a subset of the second. */ |
6e042ef4 JH |
479 | ase1 = get_alias_set_entry (set1); |
480 | if (ase1 != 0 | |
481 | && ase1->children && ase1->children->get (set2)) | |
3ecf9d13 JH |
482 | { |
483 | ++alias_stats.num_dag; | |
484 | return 1; | |
485 | } | |
3932261a MM |
486 | |
487 | /* Now do the same, but with the alias sets reversed. */ | |
6e042ef4 JH |
488 | ase2 = get_alias_set_entry (set2); |
489 | if (ase2 != 0 | |
490 | && ase2->children && ase2->children->get (set1)) | |
3ecf9d13 JH |
491 | { |
492 | ++alias_stats.num_dag; | |
493 | return 1; | |
494 | } | |
6e042ef4 JH |
495 | |
496 | /* We want void * to be compatible with any other pointer without | |
497 | really dropping it to alias set 0. Doing so would make it | |
498 | compatible with all non-pointer types too. | |
499 | ||
500 | This is not strictly necessary by the C/C++ language | |
501 | standards, but avoids common type punning mistakes. In | |
502 | addition to that, we need the existence of such universal | |
503 | pointer to implement Fortran's C_PTR type (which is defined as | |
504 | type compatible with all C pointers). */ | |
505 | if (ase1 && ase2 && ase1->has_pointer && ase2->has_pointer) | |
506 | { | |
507 | alias_set_type voidptr_set = TYPE_ALIAS_SET (ptr_type_node); | |
508 | ||
509 | /* If one of the sets corresponds to universal pointer, | |
510 | we consider it to conflict with anything that is | |
511 | or contains pointer. */ | |
512 | if (set1 == voidptr_set || set2 == voidptr_set) | |
513 | { | |
514 | ++alias_stats.num_universal; | |
515 | return true; | |
516 | } | |
517 | /* If one of sets is (non-universal) pointer and the other | |
518 | contains universal pointer, we also get conflict. */ | |
519 | if (ase1->is_pointer && set2 != voidptr_set | |
520 | && ase2->children && ase2->children->get (voidptr_set)) | |
521 | { | |
522 | ++alias_stats.num_universal; | |
523 | return true; | |
524 | } | |
525 | if (ase2->is_pointer && set1 != voidptr_set | |
526 | && ase1->children && ase1->children->get (voidptr_set)) | |
527 | { | |
528 | ++alias_stats.num_universal; | |
529 | return true; | |
530 | } | |
531 | } | |
532 | ||
3ecf9d13 | 533 | ++alias_stats.num_disambiguated; |
3932261a | 534 | |
1da68f56 | 535 | /* The two alias sets are distinct and neither one is the |
836f7794 | 536 | child of the other. Therefore, they cannot conflict. */ |
1da68f56 | 537 | return 0; |
3932261a | 538 | } |
5399d643 | 539 | |
836f7794 | 540 | /* Return 1 if the two specified alias sets will always conflict. */ |
5399d643 JW |
541 | |
542 | int | |
4862826d | 543 | alias_sets_must_conflict_p (alias_set_type set1, alias_set_type set2) |
5399d643 | 544 | { |
bd04cddf JH |
545 | /* Disable TBAA oracle with !flag_strict_aliasing. */ |
546 | if (!flag_strict_aliasing) | |
547 | return 1; | |
3ecf9d13 JH |
548 | if (set1 == 0 || set2 == 0) |
549 | { | |
550 | ++alias_stats.num_alias_zero; | |
551 | return 1; | |
552 | } | |
553 | if (set1 == set2) | |
554 | { | |
555 | ++alias_stats.num_same_alias_set; | |
556 | return 1; | |
557 | } | |
5399d643 JW |
558 | |
559 | return 0; | |
560 | } | |
561 | ||
1da68f56 RK |
562 | /* Return 1 if any MEM object of type T1 will always conflict (using the |
563 | dependency routines in this file) with any MEM object of type T2. | |
564 | This is used when allocating temporary storage. If T1 and/or T2 are | |
565 | NULL_TREE, it means we know nothing about the storage. */ | |
566 | ||
567 | int | |
4682ae04 | 568 | objects_must_conflict_p (tree t1, tree t2) |
1da68f56 | 569 | { |
4862826d | 570 | alias_set_type set1, set2; |
82d610ec | 571 | |
e8ea2809 RK |
572 | /* If neither has a type specified, we don't know if they'll conflict |
573 | because we may be using them to store objects of various types, for | |
574 | example the argument and local variables areas of inlined functions. */ | |
981a4c34 | 575 | if (t1 == 0 && t2 == 0) |
e8ea2809 RK |
576 | return 0; |
577 | ||
1da68f56 | 578 | /* If they are the same type, they must conflict. */ |
3ecf9d13 JH |
579 | if (t1 == t2) |
580 | { | |
581 | ++alias_stats.num_same_objects; | |
582 | return 1; | |
583 | } | |
584 | /* Likewise if both are volatile. */ | |
585 | if (t1 != 0 && TYPE_VOLATILE (t1) && t2 != 0 && TYPE_VOLATILE (t2)) | |
586 | { | |
587 | ++alias_stats.num_volatile; | |
588 | return 1; | |
589 | } | |
1da68f56 | 590 | |
82d610ec RK |
591 | set1 = t1 ? get_alias_set (t1) : 0; |
592 | set2 = t2 ? get_alias_set (t2) : 0; | |
1da68f56 | 593 | |
836f7794 EB |
594 | /* We can't use alias_sets_conflict_p because we must make sure |
595 | that every subtype of t1 will conflict with every subtype of | |
82d610ec RK |
596 | t2 for which a pair of subobjects of these respective subtypes |
597 | overlaps on the stack. */ | |
836f7794 | 598 | return alias_sets_must_conflict_p (set1, set2); |
1da68f56 RK |
599 | } |
600 | \f | |
b4ada065 RB |
601 | /* Return the outermost parent of component present in the chain of |
602 | component references handled by get_inner_reference in T with the | |
603 | following property: | |
604 | - the component is non-addressable, or | |
605 | - the parent has alias set zero, | |
606 | or NULL_TREE if no such parent exists. In the former cases, the alias | |
607 | set of this parent is the alias set that must be used for T itself. */ | |
608 | ||
609 | tree | |
610 | component_uses_parent_alias_set_from (const_tree t) | |
6e24b709 | 611 | { |
b4ada065 | 612 | const_tree found = NULL_TREE; |
afe84921 | 613 | |
b4ada065 RB |
614 | while (handled_component_p (t)) |
615 | { | |
afe84921 RH |
616 | switch (TREE_CODE (t)) |
617 | { | |
618 | case COMPONENT_REF: | |
619 | if (DECL_NONADDRESSABLE_P (TREE_OPERAND (t, 1))) | |
b4ada065 | 620 | found = t; |
afe84921 RH |
621 | break; |
622 | ||
623 | case ARRAY_REF: | |
624 | case ARRAY_RANGE_REF: | |
625 | if (TYPE_NONALIASED_COMPONENT (TREE_TYPE (TREE_OPERAND (t, 0)))) | |
b4ada065 | 626 | found = t; |
afe84921 RH |
627 | break; |
628 | ||
629 | case REALPART_EXPR: | |
630 | case IMAGPART_EXPR: | |
631 | break; | |
632 | ||
b4ada065 RB |
633 | case BIT_FIELD_REF: |
634 | case VIEW_CONVERT_EXPR: | |
afe84921 | 635 | /* Bitfields and casts are never addressable. */ |
b4ada065 RB |
636 | found = t; |
637 | break; | |
638 | ||
639 | default: | |
640 | gcc_unreachable (); | |
afe84921 RH |
641 | } |
642 | ||
b4ada065 RB |
643 | if (get_alias_set (TREE_TYPE (TREE_OPERAND (t, 0))) == 0) |
644 | found = t; | |
645 | ||
afe84921 RH |
646 | t = TREE_OPERAND (t, 0); |
647 | } | |
b4ada065 RB |
648 | |
649 | if (found) | |
650 | return TREE_OPERAND (found, 0); | |
651 | ||
652 | return NULL_TREE; | |
6e24b709 RK |
653 | } |
654 | ||
f40333af RB |
655 | |
656 | /* Return whether the pointer-type T effective for aliasing may | |
657 | access everything and thus the reference has to be assigned | |
658 | alias-set zero. */ | |
659 | ||
660 | static bool | |
661 | ref_all_alias_ptr_type_p (const_tree t) | |
662 | { | |
663 | return (TREE_CODE (TREE_TYPE (t)) == VOID_TYPE | |
664 | || TYPE_REF_CAN_ALIAS_ALL (t)); | |
665 | } | |
666 | ||
5006671f RG |
667 | /* Return the alias set for the memory pointed to by T, which may be |
668 | either a type or an expression. Return -1 if there is nothing | |
669 | special about dereferencing T. */ | |
670 | ||
671 | static alias_set_type | |
672 | get_deref_alias_set_1 (tree t) | |
673 | { | |
5b21f0f3 | 674 | /* All we care about is the type. */ |
5006671f | 675 | if (! TYPE_P (t)) |
5b21f0f3 | 676 | t = TREE_TYPE (t); |
5006671f RG |
677 | |
678 | /* If we have an INDIRECT_REF via a void pointer, we don't | |
679 | know anything about what that might alias. Likewise if the | |
680 | pointer is marked that way. */ | |
f40333af | 681 | if (ref_all_alias_ptr_type_p (t)) |
5006671f RG |
682 | return 0; |
683 | ||
684 | return -1; | |
685 | } | |
686 | ||
687 | /* Return the alias set for the memory pointed to by T, which may be | |
688 | either a type or an expression. */ | |
689 | ||
690 | alias_set_type | |
691 | get_deref_alias_set (tree t) | |
692 | { | |
f40333af RB |
693 | /* If we're not doing any alias analysis, just assume everything |
694 | aliases everything else. */ | |
695 | if (!flag_strict_aliasing) | |
696 | return 0; | |
697 | ||
5006671f RG |
698 | alias_set_type set = get_deref_alias_set_1 (t); |
699 | ||
700 | /* Fall back to the alias-set of the pointed-to type. */ | |
701 | if (set == -1) | |
702 | { | |
703 | if (! TYPE_P (t)) | |
704 | t = TREE_TYPE (t); | |
705 | set = get_alias_set (TREE_TYPE (t)); | |
706 | } | |
707 | ||
708 | return set; | |
709 | } | |
710 | ||
f40333af RB |
711 | /* Return the pointer-type relevant for TBAA purposes from the |
712 | memory reference tree *T or NULL_TREE in which case *T is | |
713 | adjusted to point to the outermost component reference that | |
714 | can be used for assigning an alias set. */ | |
715 | ||
716 | static tree | |
717 | reference_alias_ptr_type_1 (tree *t) | |
718 | { | |
719 | tree inner; | |
720 | ||
721 | /* Get the base object of the reference. */ | |
722 | inner = *t; | |
723 | while (handled_component_p (inner)) | |
724 | { | |
725 | /* If there is a VIEW_CONVERT_EXPR in the chain we cannot use | |
726 | the type of any component references that wrap it to | |
727 | determine the alias-set. */ | |
728 | if (TREE_CODE (inner) == VIEW_CONVERT_EXPR) | |
729 | *t = TREE_OPERAND (inner, 0); | |
730 | inner = TREE_OPERAND (inner, 0); | |
731 | } | |
732 | ||
733 | /* Handle pointer dereferences here, they can override the | |
734 | alias-set. */ | |
735 | if (INDIRECT_REF_P (inner) | |
736 | && ref_all_alias_ptr_type_p (TREE_TYPE (TREE_OPERAND (inner, 0)))) | |
737 | return TREE_TYPE (TREE_OPERAND (inner, 0)); | |
738 | else if (TREE_CODE (inner) == TARGET_MEM_REF) | |
739 | return TREE_TYPE (TMR_OFFSET (inner)); | |
740 | else if (TREE_CODE (inner) == MEM_REF | |
741 | && ref_all_alias_ptr_type_p (TREE_TYPE (TREE_OPERAND (inner, 1)))) | |
742 | return TREE_TYPE (TREE_OPERAND (inner, 1)); | |
743 | ||
744 | /* If the innermost reference is a MEM_REF that has a | |
745 | conversion embedded treat it like a VIEW_CONVERT_EXPR above, | |
746 | using the memory access type for determining the alias-set. */ | |
747 | if (TREE_CODE (inner) == MEM_REF | |
748 | && (TYPE_MAIN_VARIANT (TREE_TYPE (inner)) | |
749 | != TYPE_MAIN_VARIANT | |
750 | (TREE_TYPE (TREE_TYPE (TREE_OPERAND (inner, 1)))))) | |
751 | return TREE_TYPE (TREE_OPERAND (inner, 1)); | |
752 | ||
b4ada065 RB |
753 | /* Otherwise, pick up the outermost object that we could have |
754 | a pointer to. */ | |
755 | tree tem = component_uses_parent_alias_set_from (*t); | |
756 | if (tem) | |
757 | *t = tem; | |
f40333af RB |
758 | |
759 | return NULL_TREE; | |
760 | } | |
761 | ||
762 | /* Return the pointer-type relevant for TBAA purposes from the | |
763 | gimple memory reference tree T. This is the type to be used for | |
764 | the offset operand of MEM_REF or TARGET_MEM_REF replacements of T | |
765 | and guarantees that get_alias_set will return the same alias | |
766 | set for T and the replacement. */ | |
767 | ||
768 | tree | |
769 | reference_alias_ptr_type (tree t) | |
770 | { | |
771 | tree ptype = reference_alias_ptr_type_1 (&t); | |
772 | /* If there is a given pointer type for aliasing purposes, return it. */ | |
773 | if (ptype != NULL_TREE) | |
774 | return ptype; | |
775 | ||
776 | /* Otherwise build one from the outermost component reference we | |
777 | may use. */ | |
778 | if (TREE_CODE (t) == MEM_REF | |
779 | || TREE_CODE (t) == TARGET_MEM_REF) | |
780 | return TREE_TYPE (TREE_OPERAND (t, 1)); | |
781 | else | |
782 | return build_pointer_type (TYPE_MAIN_VARIANT (TREE_TYPE (t))); | |
783 | } | |
784 | ||
785 | /* Return whether the pointer-types T1 and T2 used to determine | |
786 | two alias sets of two references will yield the same answer | |
787 | from get_deref_alias_set. */ | |
788 | ||
789 | bool | |
790 | alias_ptr_types_compatible_p (tree t1, tree t2) | |
791 | { | |
792 | if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2)) | |
793 | return true; | |
794 | ||
795 | if (ref_all_alias_ptr_type_p (t1) | |
796 | || ref_all_alias_ptr_type_p (t2)) | |
797 | return false; | |
798 | ||
799 | return (TYPE_MAIN_VARIANT (TREE_TYPE (t1)) | |
800 | == TYPE_MAIN_VARIANT (TREE_TYPE (t2))); | |
801 | } | |
802 | ||
6e042ef4 JH |
803 | /* Create emptry alias set entry. */ |
804 | ||
02ced957 | 805 | alias_set_entry * |
6e042ef4 JH |
806 | init_alias_set_entry (alias_set_type set) |
807 | { | |
02ced957 | 808 | alias_set_entry *ase = ggc_alloc<alias_set_entry> (); |
6e042ef4 JH |
809 | ase->alias_set = set; |
810 | ase->children = NULL; | |
811 | ase->has_zero_child = false; | |
812 | ase->is_pointer = false; | |
813 | ase->has_pointer = false; | |
814 | gcc_checking_assert (!get_alias_set_entry (set)); | |
815 | (*alias_sets)[set] = ase; | |
816 | return ase; | |
817 | } | |
818 | ||
3bdf5ad1 RK |
819 | /* Return the alias set for T, which may be either a type or an |
820 | expression. Call language-specific routine for help, if needed. */ | |
821 | ||
4862826d | 822 | alias_set_type |
4682ae04 | 823 | get_alias_set (tree t) |
3bdf5ad1 | 824 | { |
4862826d | 825 | alias_set_type set; |
3bdf5ad1 | 826 | |
bd04cddf JH |
827 | /* We can not give up with -fno-strict-aliasing because we need to build |
828 | proper type representation for possible functions which are build with | |
829 | -fstirct-aliasing. */ | |
830 | ||
831 | /* return 0 if this or its type is an error. */ | |
832 | if (t == error_mark_node | |
3bdf5ad1 RK |
833 | || (! TYPE_P (t) |
834 | && (TREE_TYPE (t) == 0 || TREE_TYPE (t) == error_mark_node))) | |
835 | return 0; | |
836 | ||
837 | /* We can be passed either an expression or a type. This and the | |
f47e9b4e RK |
838 | language-specific routine may make mutually-recursive calls to each other |
839 | to figure out what to do. At each juncture, we see if this is a tree | |
840 | that the language may need to handle specially. First handle things that | |
738cc472 | 841 | aren't types. */ |
f824e5c3 | 842 | if (! TYPE_P (t)) |
3bdf5ad1 | 843 | { |
70f34814 RG |
844 | /* Give the language a chance to do something with this tree |
845 | before we look at it. */ | |
8ac61af7 | 846 | STRIP_NOPS (t); |
ae2bcd98 | 847 | set = lang_hooks.get_alias_set (t); |
8ac61af7 RK |
848 | if (set != -1) |
849 | return set; | |
850 | ||
f40333af RB |
851 | /* Get the alias pointer-type to use or the outermost object |
852 | that we could have a pointer to. */ | |
853 | tree ptype = reference_alias_ptr_type_1 (&t); | |
854 | if (ptype != NULL) | |
855 | return get_deref_alias_set (ptype); | |
f824e5c3 | 856 | |
738cc472 RK |
857 | /* If we've already determined the alias set for a decl, just return |
858 | it. This is necessary for C++ anonymous unions, whose component | |
859 | variables don't look like union members (boo!). */ | |
5755cd38 | 860 | if (TREE_CODE (t) == VAR_DECL |
3c0cb5de | 861 | && DECL_RTL_SET_P (t) && MEM_P (DECL_RTL (t))) |
5755cd38 JM |
862 | return MEM_ALIAS_SET (DECL_RTL (t)); |
863 | ||
f824e5c3 RK |
864 | /* Now all we care about is the type. */ |
865 | t = TREE_TYPE (t); | |
3bdf5ad1 RK |
866 | } |
867 | ||
3bdf5ad1 | 868 | /* Variant qualifiers don't affect the alias set, so get the main |
daad0278 | 869 | variant. */ |
3bdf5ad1 | 870 | t = TYPE_MAIN_VARIANT (t); |
daad0278 RG |
871 | |
872 | /* Always use the canonical type as well. If this is a type that | |
873 | requires structural comparisons to identify compatible types | |
874 | use alias set zero. */ | |
875 | if (TYPE_STRUCTURAL_EQUALITY_P (t)) | |
cb9c2485 JM |
876 | { |
877 | /* Allow the language to specify another alias set for this | |
878 | type. */ | |
879 | set = lang_hooks.get_alias_set (t); | |
880 | if (set != -1) | |
881 | return set; | |
aea50b45 JH |
882 | /* Handle structure type equality for pointer types, arrays and vectors. |
883 | This is easy to do, because the code bellow ignore canonical types on | |
884 | these anyway. This is important for LTO, where TYPE_CANONICAL for | |
885 | pointers can not be meaningfuly computed by the frotnend. */ | |
886 | if (canonical_type_used_p (t)) | |
f85d2487 JH |
887 | { |
888 | /* In LTO we set canonical types for all types where it makes | |
889 | sense to do so. Double check we did not miss some type. */ | |
890 | gcc_checking_assert (!in_lto_p || !type_with_alias_set_p (t)); | |
891 | return 0; | |
892 | } | |
893 | } | |
894 | else | |
895 | { | |
896 | t = TYPE_CANONICAL (t); | |
897 | gcc_checking_assert (!TYPE_STRUCTURAL_EQUALITY_P (t)); | |
cb9c2485 | 898 | } |
daad0278 RG |
899 | |
900 | /* If this is a type with a known alias set, return it. */ | |
ba6a6a1d | 901 | gcc_checking_assert (t == TYPE_MAIN_VARIANT (t)); |
738cc472 | 902 | if (TYPE_ALIAS_SET_KNOWN_P (t)) |
3bdf5ad1 RK |
903 | return TYPE_ALIAS_SET (t); |
904 | ||
36784d0e RG |
905 | /* We don't want to set TYPE_ALIAS_SET for incomplete types. */ |
906 | if (!COMPLETE_TYPE_P (t)) | |
907 | { | |
908 | /* For arrays with unknown size the conservative answer is the | |
909 | alias set of the element type. */ | |
910 | if (TREE_CODE (t) == ARRAY_TYPE) | |
911 | return get_alias_set (TREE_TYPE (t)); | |
912 | ||
913 | /* But return zero as a conservative answer for incomplete types. */ | |
914 | return 0; | |
915 | } | |
916 | ||
3bdf5ad1 | 917 | /* See if the language has special handling for this type. */ |
ae2bcd98 | 918 | set = lang_hooks.get_alias_set (t); |
8ac61af7 | 919 | if (set != -1) |
738cc472 | 920 | return set; |
2bf105ab | 921 | |
3bdf5ad1 RK |
922 | /* There are no objects of FUNCTION_TYPE, so there's no point in |
923 | using up an alias set for them. (There are, of course, pointers | |
924 | and references to functions, but that's different.) */ | |
7be7d292 | 925 | else if (TREE_CODE (t) == FUNCTION_TYPE || TREE_CODE (t) == METHOD_TYPE) |
3bdf5ad1 | 926 | set = 0; |
74d86f4f RH |
927 | |
928 | /* Unless the language specifies otherwise, let vector types alias | |
929 | their components. This avoids some nasty type punning issues in | |
930 | normal usage. And indeed lets vectors be treated more like an | |
931 | array slice. */ | |
932 | else if (TREE_CODE (t) == VECTOR_TYPE) | |
933 | set = get_alias_set (TREE_TYPE (t)); | |
934 | ||
4653cae5 RG |
935 | /* Unless the language specifies otherwise, treat array types the |
936 | same as their components. This avoids the asymmetry we get | |
937 | through recording the components. Consider accessing a | |
938 | character(kind=1) through a reference to a character(kind=1)[1:1]. | |
939 | Or consider if we want to assign integer(kind=4)[0:D.1387] and | |
940 | integer(kind=4)[4] the same alias set or not. | |
941 | Just be pragmatic here and make sure the array and its element | |
942 | type get the same alias set assigned. */ | |
aea50b45 JH |
943 | else if (TREE_CODE (t) == ARRAY_TYPE |
944 | && (!TYPE_NONALIASED_COMPONENT (t) | |
945 | || TYPE_STRUCTURAL_EQUALITY_P (t))) | |
4653cae5 RG |
946 | set = get_alias_set (TREE_TYPE (t)); |
947 | ||
0ceb0201 RG |
948 | /* From the former common C and C++ langhook implementation: |
949 | ||
950 | Unfortunately, there is no canonical form of a pointer type. | |
951 | In particular, if we have `typedef int I', then `int *', and | |
952 | `I *' are different types. So, we have to pick a canonical | |
953 | representative. We do this below. | |
954 | ||
955 | Technically, this approach is actually more conservative that | |
956 | it needs to be. In particular, `const int *' and `int *' | |
957 | should be in different alias sets, according to the C and C++ | |
958 | standard, since their types are not the same, and so, | |
959 | technically, an `int **' and `const int **' cannot point at | |
960 | the same thing. | |
961 | ||
962 | But, the standard is wrong. In particular, this code is | |
963 | legal C++: | |
964 | ||
965 | int *ip; | |
966 | int **ipp = &ip; | |
967 | const int* const* cipp = ipp; | |
968 | And, it doesn't make sense for that to be legal unless you | |
969 | can dereference IPP and CIPP. So, we ignore cv-qualifiers on | |
970 | the pointed-to types. This issue has been reported to the | |
971 | C++ committee. | |
972 | ||
6e042ef4 JH |
973 | For this reason go to canonical type of the unqalified pointer type. |
974 | Until GCC 6 this code set all pointers sets to have alias set of | |
975 | ptr_type_node but that is a bad idea, because it prevents disabiguations | |
976 | in between pointers. For Firefox this accounts about 20% of all | |
977 | disambiguations in the program. */ | |
f85d2487 | 978 | else if (POINTER_TYPE_P (t) && t != ptr_type_node) |
6e042ef4 JH |
979 | { |
980 | tree p; | |
981 | auto_vec <bool, 8> reference; | |
982 | ||
983 | /* Unnest all pointers and references. | |
f85d2487 JH |
984 | We also want to make pointer to array/vector equivalent to pointer to |
985 | its element (see the reasoning above). Skip all those types, too. */ | |
6e042ef4 | 986 | for (p = t; POINTER_TYPE_P (p) |
aea50b45 JH |
987 | || (TREE_CODE (p) == ARRAY_TYPE |
988 | && (!TYPE_NONALIASED_COMPONENT (p) | |
989 | || !COMPLETE_TYPE_P (p) | |
990 | || TYPE_STRUCTURAL_EQUALITY_P (p))) | |
f85d2487 | 991 | || TREE_CODE (p) == VECTOR_TYPE; |
6e042ef4 JH |
992 | p = TREE_TYPE (p)) |
993 | { | |
54363f8a JH |
994 | /* Ada supports recusive pointers. Instead of doing recrusion check |
995 | just give up once the preallocated space of 8 elements is up. | |
996 | In this case just punt to void * alias set. */ | |
997 | if (reference.length () == 8) | |
998 | { | |
999 | p = ptr_type_node; | |
1000 | break; | |
1001 | } | |
6e042ef4 | 1002 | if (TREE_CODE (p) == REFERENCE_TYPE) |
f85d2487 JH |
1003 | /* In LTO we want languages that use references to be compatible |
1004 | with languages that use pointers. */ | |
1005 | reference.safe_push (true && !in_lto_p); | |
6e042ef4 JH |
1006 | if (TREE_CODE (p) == POINTER_TYPE) |
1007 | reference.safe_push (false); | |
1008 | } | |
1009 | p = TYPE_MAIN_VARIANT (p); | |
1010 | ||
1011 | /* Make void * compatible with char * and also void **. | |
1012 | Programs are commonly violating TBAA by this. | |
1013 | ||
1014 | We also make void * to conflict with every pointer | |
1015 | (see record_component_aliases) and thus it is safe it to use it for | |
1016 | pointers to types with TYPE_STRUCTURAL_EQUALITY_P. */ | |
1017 | if (TREE_CODE (p) == VOID_TYPE || TYPE_STRUCTURAL_EQUALITY_P (p)) | |
1018 | set = get_alias_set (ptr_type_node); | |
1019 | else | |
1020 | { | |
f85d2487 | 1021 | /* Rebuild pointer type starting from canonical types using |
6e042ef4 JH |
1022 | unqualified pointers and references only. This way all such |
1023 | pointers will have the same alias set and will conflict with | |
1024 | each other. | |
1025 | ||
1026 | Most of time we already have pointers or references of a given type. | |
1027 | If not we build new one just to be sure that if someone later | |
1028 | (probably only middle-end can, as we should assign all alias | |
1029 | classes only after finishing translation unit) builds the pointer | |
1030 | type, the canonical type will match. */ | |
1031 | p = TYPE_CANONICAL (p); | |
1032 | while (!reference.is_empty ()) | |
1033 | { | |
1034 | if (reference.pop ()) | |
1035 | p = build_reference_type (p); | |
1036 | else | |
1037 | p = build_pointer_type (p); | |
f85d2487 JH |
1038 | gcc_checking_assert (p == TYPE_MAIN_VARIANT (p)); |
1039 | /* build_pointer_type should always return the canonical type. | |
1040 | For LTO TYPE_CANOINCAL may be NULL, because we do not compute | |
1041 | them. Be sure that frontends do not glob canonical types of | |
1042 | pointers in unexpected way and that p == TYPE_CANONICAL (p) | |
1043 | in all other cases. */ | |
1044 | gcc_checking_assert (!TYPE_CANONICAL (p) | |
1045 | || p == TYPE_CANONICAL (p)); | |
6e042ef4 | 1046 | } |
6e042ef4 JH |
1047 | |
1048 | /* Assign the alias set to both p and t. | |
1049 | We can not call get_alias_set (p) here as that would trigger | |
1050 | infinite recursion when p == t. In other cases it would just | |
1051 | trigger unnecesary legwork of rebuilding the pointer again. */ | |
ba6a6a1d | 1052 | gcc_checking_assert (p == TYPE_MAIN_VARIANT (p)); |
6e042ef4 JH |
1053 | if (TYPE_ALIAS_SET_KNOWN_P (p)) |
1054 | set = TYPE_ALIAS_SET (p); | |
1055 | else | |
1056 | { | |
1057 | set = new_alias_set (); | |
1058 | TYPE_ALIAS_SET (p) = set; | |
1059 | } | |
1060 | } | |
1061 | } | |
f85d2487 JH |
1062 | /* Alias set of ptr_type_node is special and serve as universal pointer which |
1063 | is TBAA compatible with every other pointer type. Be sure we have the | |
1064 | alias set built even for LTO which otherwise keeps all TYPE_CANONICAL | |
1065 | of pointer types NULL. */ | |
1066 | else if (t == ptr_type_node) | |
1067 | set = new_alias_set (); | |
0ceb0201 | 1068 | |
7be7d292 | 1069 | /* Otherwise make a new alias set for this type. */ |
3bdf5ad1 | 1070 | else |
96d91dcf RG |
1071 | { |
1072 | /* Each canonical type gets its own alias set, so canonical types | |
1073 | shouldn't form a tree. It doesn't really matter for types | |
1074 | we handle specially above, so only check it where it possibly | |
1075 | would result in a bogus alias set. */ | |
1076 | gcc_checking_assert (TYPE_CANONICAL (t) == t); | |
1077 | ||
1078 | set = new_alias_set (); | |
1079 | } | |
3bdf5ad1 RK |
1080 | |
1081 | TYPE_ALIAS_SET (t) = set; | |
2bf105ab | 1082 | |
7be7d292 EB |
1083 | /* If this is an aggregate type or a complex type, we must record any |
1084 | component aliasing information. */ | |
1d79fd2c | 1085 | if (AGGREGATE_TYPE_P (t) || TREE_CODE (t) == COMPLEX_TYPE) |
2bf105ab RK |
1086 | record_component_aliases (t); |
1087 | ||
6e042ef4 JH |
1088 | /* We treat pointer types specially in alias_set_subset_of. */ |
1089 | if (POINTER_TYPE_P (t) && set) | |
1090 | { | |
02ced957 | 1091 | alias_set_entry *ase = get_alias_set_entry (set); |
6e042ef4 JH |
1092 | if (!ase) |
1093 | ase = init_alias_set_entry (set); | |
1094 | ase->is_pointer = true; | |
1095 | ase->has_pointer = true; | |
1096 | } | |
1097 | ||
3bdf5ad1 RK |
1098 | return set; |
1099 | } | |
1100 | ||
1101 | /* Return a brand-new alias set. */ | |
1102 | ||
4862826d | 1103 | alias_set_type |
4682ae04 | 1104 | new_alias_set (void) |
3bdf5ad1 | 1105 | { |
bd04cddf JH |
1106 | if (alias_sets == 0) |
1107 | vec_safe_push (alias_sets, (alias_set_entry *) NULL); | |
1108 | vec_safe_push (alias_sets, (alias_set_entry *) NULL); | |
1109 | return alias_sets->length () - 1; | |
3bdf5ad1 | 1110 | } |
3932261a | 1111 | |
01d28c3f JM |
1112 | /* Indicate that things in SUBSET can alias things in SUPERSET, but that |
1113 | not everything that aliases SUPERSET also aliases SUBSET. For example, | |
1114 | in C, a store to an `int' can alias a load of a structure containing an | |
1115 | `int', and vice versa. But it can't alias a load of a 'double' member | |
1116 | of the same structure. Here, the structure would be the SUPERSET and | |
1117 | `int' the SUBSET. This relationship is also described in the comment at | |
1118 | the beginning of this file. | |
1119 | ||
1120 | This function should be called only once per SUPERSET/SUBSET pair. | |
3932261a MM |
1121 | |
1122 | It is illegal for SUPERSET to be zero; everything is implicitly a | |
1123 | subset of alias set zero. */ | |
1124 | ||
794511d2 | 1125 | void |
4862826d | 1126 | record_alias_subset (alias_set_type superset, alias_set_type subset) |
3932261a | 1127 | { |
02ced957 TS |
1128 | alias_set_entry *superset_entry; |
1129 | alias_set_entry *subset_entry; | |
3932261a | 1130 | |
f47e9b4e RK |
1131 | /* It is possible in complex type situations for both sets to be the same, |
1132 | in which case we can ignore this operation. */ | |
1133 | if (superset == subset) | |
1134 | return; | |
1135 | ||
298e6adc | 1136 | gcc_assert (superset); |
3932261a MM |
1137 | |
1138 | superset_entry = get_alias_set_entry (superset); | |
ca7fd9cd | 1139 | if (superset_entry == 0) |
3932261a MM |
1140 | { |
1141 | /* Create an entry for the SUPERSET, so that we have a place to | |
1142 | attach the SUBSET. */ | |
6e042ef4 | 1143 | superset_entry = init_alias_set_entry (superset); |
3932261a MM |
1144 | } |
1145 | ||
2bf105ab RK |
1146 | if (subset == 0) |
1147 | superset_entry->has_zero_child = 1; | |
1148 | else | |
1149 | { | |
1150 | subset_entry = get_alias_set_entry (subset); | |
6e042ef4 JH |
1151 | if (!superset_entry->children) |
1152 | superset_entry->children | |
fb5c464a | 1153 | = hash_map<alias_set_hash, int>::create_ggc (64); |
2bf105ab RK |
1154 | /* If there is an entry for the subset, enter all of its children |
1155 | (if they are not already present) as children of the SUPERSET. */ | |
ca7fd9cd | 1156 | if (subset_entry) |
2bf105ab RK |
1157 | { |
1158 | if (subset_entry->has_zero_child) | |
6e042ef4 JH |
1159 | superset_entry->has_zero_child = true; |
1160 | if (subset_entry->has_pointer) | |
1161 | superset_entry->has_pointer = true; | |
d4b60170 | 1162 | |
6e042ef4 JH |
1163 | if (subset_entry->children) |
1164 | { | |
fb5c464a | 1165 | hash_map<alias_set_hash, int>::iterator iter |
6e042ef4 JH |
1166 | = subset_entry->children->begin (); |
1167 | for (; iter != subset_entry->children->end (); ++iter) | |
1168 | superset_entry->children->put ((*iter).first, (*iter).second); | |
1169 | } | |
2bf105ab | 1170 | } |
3932261a | 1171 | |
2bf105ab | 1172 | /* Enter the SUBSET itself as a child of the SUPERSET. */ |
de144fb2 | 1173 | superset_entry->children->put (subset, 0); |
2bf105ab | 1174 | } |
3932261a MM |
1175 | } |
1176 | ||
a0c33338 RK |
1177 | /* Record that component types of TYPE, if any, are part of that type for |
1178 | aliasing purposes. For record types, we only record component types | |
b5487346 EB |
1179 | for fields that are not marked non-addressable. For array types, we |
1180 | only record the component type if it is not marked non-aliased. */ | |
a0c33338 RK |
1181 | |
1182 | void | |
4682ae04 | 1183 | record_component_aliases (tree type) |
a0c33338 | 1184 | { |
4862826d | 1185 | alias_set_type superset = get_alias_set (type); |
a0c33338 RK |
1186 | tree field; |
1187 | ||
1188 | if (superset == 0) | |
1189 | return; | |
1190 | ||
1191 | switch (TREE_CODE (type)) | |
1192 | { | |
a0c33338 RK |
1193 | case RECORD_TYPE: |
1194 | case UNION_TYPE: | |
1195 | case QUAL_UNION_TYPE: | |
910ad8de | 1196 | for (field = TYPE_FIELDS (type); field != 0; field = DECL_CHAIN (field)) |
b5487346 | 1197 | if (TREE_CODE (field) == FIELD_DECL && !DECL_NONADDRESSABLE_P (field)) |
f85d2487 JH |
1198 | { |
1199 | /* LTO type merging does not make any difference between | |
1200 | component pointer types. We may have | |
1201 | ||
1202 | struct foo {int *a;}; | |
1203 | ||
1204 | as TYPE_CANONICAL of | |
1205 | ||
1206 | struct bar {float *a;}; | |
1207 | ||
1208 | Because accesses to int * and float * do not alias, we would get | |
1209 | false negative when accessing the same memory location by | |
1210 | float ** and bar *. We thus record the canonical type as: | |
1211 | ||
1212 | struct {void *a;}; | |
1213 | ||
1214 | void * is special cased and works as a universal pointer type. | |
1215 | Accesses to it conflicts with accesses to any other pointer | |
1216 | type. */ | |
1217 | tree t = TREE_TYPE (field); | |
1218 | if (in_lto_p) | |
1219 | { | |
1220 | /* VECTOR_TYPE and ARRAY_TYPE share the alias set with their | |
1221 | element type and that type has to be normalized to void *, | |
1222 | too, in the case it is a pointer. */ | |
aea50b45 JH |
1223 | while (!canonical_type_used_p (t) && !POINTER_TYPE_P (t)) |
1224 | { | |
1225 | gcc_checking_assert (TYPE_STRUCTURAL_EQUALITY_P (t)); | |
1226 | t = TREE_TYPE (t); | |
1227 | } | |
f85d2487 JH |
1228 | if (POINTER_TYPE_P (t)) |
1229 | t = ptr_type_node; | |
aea50b45 JH |
1230 | else if (flag_checking) |
1231 | gcc_checking_assert (get_alias_set (t) | |
1232 | == get_alias_set (TREE_TYPE (field))); | |
f85d2487 | 1233 | } |
aea50b45 | 1234 | |
f85d2487 JH |
1235 | record_alias_subset (superset, get_alias_set (t)); |
1236 | } | |
a0c33338 RK |
1237 | break; |
1238 | ||
1d79fd2c JW |
1239 | case COMPLEX_TYPE: |
1240 | record_alias_subset (superset, get_alias_set (TREE_TYPE (type))); | |
1241 | break; | |
1242 | ||
4653cae5 RG |
1243 | /* VECTOR_TYPE and ARRAY_TYPE share the alias set with their |
1244 | element type. */ | |
1245 | ||
a0c33338 RK |
1246 | default: |
1247 | break; | |
1248 | } | |
1249 | } | |
1250 | ||
3bdf5ad1 RK |
1251 | /* Allocate an alias set for use in storing and reading from the varargs |
1252 | spill area. */ | |
1253 | ||
4862826d | 1254 | static GTY(()) alias_set_type varargs_set = -1; |
f103e34d | 1255 | |
4862826d | 1256 | alias_set_type |
4682ae04 | 1257 | get_varargs_alias_set (void) |
3bdf5ad1 | 1258 | { |
cd3ce9b4 JM |
1259 | #if 1 |
1260 | /* We now lower VA_ARG_EXPR, and there's currently no way to attach the | |
1261 | varargs alias set to an INDIRECT_REF (FIXME!), so we can't | |
1262 | consistently use the varargs alias set for loads from the varargs | |
1263 | area. So don't use it anywhere. */ | |
1264 | return 0; | |
1265 | #else | |
f103e34d GK |
1266 | if (varargs_set == -1) |
1267 | varargs_set = new_alias_set (); | |
3bdf5ad1 | 1268 | |
f103e34d | 1269 | return varargs_set; |
cd3ce9b4 | 1270 | #endif |
3bdf5ad1 RK |
1271 | } |
1272 | ||
1273 | /* Likewise, but used for the fixed portions of the frame, e.g., register | |
1274 | save areas. */ | |
1275 | ||
4862826d | 1276 | static GTY(()) alias_set_type frame_set = -1; |
f103e34d | 1277 | |
4862826d | 1278 | alias_set_type |
4682ae04 | 1279 | get_frame_alias_set (void) |
3bdf5ad1 | 1280 | { |
f103e34d GK |
1281 | if (frame_set == -1) |
1282 | frame_set = new_alias_set (); | |
3bdf5ad1 | 1283 | |
f103e34d | 1284 | return frame_set; |
3bdf5ad1 RK |
1285 | } |
1286 | ||
9fc37b2b RS |
1287 | /* Create a new, unique base with id ID. */ |
1288 | ||
1289 | static rtx | |
1290 | unique_base_value (HOST_WIDE_INT id) | |
1291 | { | |
1292 | return gen_rtx_ADDRESS (Pmode, id); | |
1293 | } | |
1294 | ||
1295 | /* Return true if accesses based on any other base value cannot alias | |
1296 | those based on X. */ | |
1297 | ||
1298 | static bool | |
1299 | unique_base_value_p (rtx x) | |
1300 | { | |
1301 | return GET_CODE (x) == ADDRESS && GET_MODE (x) == Pmode; | |
1302 | } | |
1303 | ||
1304 | /* Return true if X is known to be a base value. */ | |
1305 | ||
1306 | static bool | |
1307 | known_base_value_p (rtx x) | |
1308 | { | |
1309 | switch (GET_CODE (x)) | |
1310 | { | |
1311 | case LABEL_REF: | |
1312 | case SYMBOL_REF: | |
1313 | return true; | |
1314 | ||
1315 | case ADDRESS: | |
1316 | /* Arguments may or may not be bases; we don't know for sure. */ | |
1317 | return GET_MODE (x) != VOIDmode; | |
1318 | ||
1319 | default: | |
1320 | return false; | |
1321 | } | |
1322 | } | |
1323 | ||
2a2c8203 JC |
1324 | /* Inside SRC, the source of a SET, find a base address. */ |
1325 | ||
9ae8ffe7 | 1326 | static rtx |
4682ae04 | 1327 | find_base_value (rtx src) |
9ae8ffe7 | 1328 | { |
713f41f9 | 1329 | unsigned int regno; |
0aacc8ed | 1330 | |
53451050 RS |
1331 | #if defined (FIND_BASE_TERM) |
1332 | /* Try machine-dependent ways to find the base term. */ | |
1333 | src = FIND_BASE_TERM (src); | |
1334 | #endif | |
1335 | ||
9ae8ffe7 JL |
1336 | switch (GET_CODE (src)) |
1337 | { | |
1338 | case SYMBOL_REF: | |
1339 | case LABEL_REF: | |
1340 | return src; | |
1341 | ||
1342 | case REG: | |
fb6754f0 | 1343 | regno = REGNO (src); |
d4b60170 | 1344 | /* At the start of a function, argument registers have known base |
2a2c8203 JC |
1345 | values which may be lost later. Returning an ADDRESS |
1346 | expression here allows optimization based on argument values | |
1347 | even when the argument registers are used for other purposes. */ | |
713f41f9 BS |
1348 | if (regno < FIRST_PSEUDO_REGISTER && copying_arguments) |
1349 | return new_reg_base_value[regno]; | |
73774bc7 | 1350 | |
eaf407a5 | 1351 | /* If a pseudo has a known base value, return it. Do not do this |
9b462c42 RH |
1352 | for non-fixed hard regs since it can result in a circular |
1353 | dependency chain for registers which have values at function entry. | |
eaf407a5 JL |
1354 | |
1355 | The test above is not sufficient because the scheduler may move | |
1356 | a copy out of an arg reg past the NOTE_INSN_FUNCTION_BEGIN. */ | |
9b462c42 | 1357 | if ((regno >= FIRST_PSEUDO_REGISTER || fixed_regs[regno]) |
9771b263 | 1358 | && regno < vec_safe_length (reg_base_value)) |
83bbd9b6 RH |
1359 | { |
1360 | /* If we're inside init_alias_analysis, use new_reg_base_value | |
1361 | to reduce the number of relaxation iterations. */ | |
1afdf91c | 1362 | if (new_reg_base_value && new_reg_base_value[regno] |
6fb5fa3c | 1363 | && DF_REG_DEF_COUNT (regno) == 1) |
83bbd9b6 RH |
1364 | return new_reg_base_value[regno]; |
1365 | ||
9771b263 DN |
1366 | if ((*reg_base_value)[regno]) |
1367 | return (*reg_base_value)[regno]; | |
83bbd9b6 | 1368 | } |
73774bc7 | 1369 | |
e3f049a8 | 1370 | return 0; |
9ae8ffe7 JL |
1371 | |
1372 | case MEM: | |
1373 | /* Check for an argument passed in memory. Only record in the | |
1374 | copying-arguments block; it is too hard to track changes | |
1375 | otherwise. */ | |
1376 | if (copying_arguments | |
1377 | && (XEXP (src, 0) == arg_pointer_rtx | |
1378 | || (GET_CODE (XEXP (src, 0)) == PLUS | |
1379 | && XEXP (XEXP (src, 0), 0) == arg_pointer_rtx))) | |
9fc37b2b | 1380 | return arg_base_value; |
9ae8ffe7 JL |
1381 | return 0; |
1382 | ||
1383 | case CONST: | |
1384 | src = XEXP (src, 0); | |
1385 | if (GET_CODE (src) != PLUS && GET_CODE (src) != MINUS) | |
1386 | break; | |
d4b60170 | 1387 | |
ec5c56db | 1388 | /* ... fall through ... */ |
2a2c8203 | 1389 | |
9ae8ffe7 JL |
1390 | case PLUS: |
1391 | case MINUS: | |
2a2c8203 | 1392 | { |
ec907dd8 JL |
1393 | rtx temp, src_0 = XEXP (src, 0), src_1 = XEXP (src, 1); |
1394 | ||
0134bf2d DE |
1395 | /* If either operand is a REG that is a known pointer, then it |
1396 | is the base. */ | |
1397 | if (REG_P (src_0) && REG_POINTER (src_0)) | |
1398 | return find_base_value (src_0); | |
1399 | if (REG_P (src_1) && REG_POINTER (src_1)) | |
1400 | return find_base_value (src_1); | |
1401 | ||
ec907dd8 JL |
1402 | /* If either operand is a REG, then see if we already have |
1403 | a known value for it. */ | |
0134bf2d | 1404 | if (REG_P (src_0)) |
ec907dd8 JL |
1405 | { |
1406 | temp = find_base_value (src_0); | |
d4b60170 | 1407 | if (temp != 0) |
ec907dd8 JL |
1408 | src_0 = temp; |
1409 | } | |
1410 | ||
0134bf2d | 1411 | if (REG_P (src_1)) |
ec907dd8 JL |
1412 | { |
1413 | temp = find_base_value (src_1); | |
d4b60170 | 1414 | if (temp!= 0) |
ec907dd8 JL |
1415 | src_1 = temp; |
1416 | } | |
2a2c8203 | 1417 | |
0134bf2d DE |
1418 | /* If either base is named object or a special address |
1419 | (like an argument or stack reference), then use it for the | |
1420 | base term. */ | |
9fc37b2b | 1421 | if (src_0 != 0 && known_base_value_p (src_0)) |
0134bf2d DE |
1422 | return src_0; |
1423 | ||
9fc37b2b | 1424 | if (src_1 != 0 && known_base_value_p (src_1)) |
0134bf2d DE |
1425 | return src_1; |
1426 | ||
d4b60170 | 1427 | /* Guess which operand is the base address: |
ec907dd8 JL |
1428 | If either operand is a symbol, then it is the base. If |
1429 | either operand is a CONST_INT, then the other is the base. */ | |
481683e1 | 1430 | if (CONST_INT_P (src_1) || CONSTANT_P (src_0)) |
2a2c8203 | 1431 | return find_base_value (src_0); |
481683e1 | 1432 | else if (CONST_INT_P (src_0) || CONSTANT_P (src_1)) |
ec907dd8 JL |
1433 | return find_base_value (src_1); |
1434 | ||
9ae8ffe7 | 1435 | return 0; |
2a2c8203 JC |
1436 | } |
1437 | ||
1438 | case LO_SUM: | |
1439 | /* The standard form is (lo_sum reg sym) so look only at the | |
1440 | second operand. */ | |
1441 | return find_base_value (XEXP (src, 1)); | |
9ae8ffe7 JL |
1442 | |
1443 | case AND: | |
1444 | /* If the second operand is constant set the base | |
ec5c56db | 1445 | address to the first operand. */ |
481683e1 | 1446 | if (CONST_INT_P (XEXP (src, 1)) && INTVAL (XEXP (src, 1)) != 0) |
2a2c8203 | 1447 | return find_base_value (XEXP (src, 0)); |
9ae8ffe7 JL |
1448 | return 0; |
1449 | ||
61f0131c | 1450 | case TRUNCATE: |
5932a4d4 | 1451 | /* As we do not know which address space the pointer is referring to, we can |
d4ebfa65 BE |
1452 | handle this only if the target does not support different pointer or |
1453 | address modes depending on the address space. */ | |
1454 | if (!target_default_pointer_address_modes_p ()) | |
1455 | break; | |
61f0131c R |
1456 | if (GET_MODE_SIZE (GET_MODE (src)) < GET_MODE_SIZE (Pmode)) |
1457 | break; | |
1458 | /* Fall through. */ | |
9ae8ffe7 | 1459 | case HIGH: |
d288e53d DE |
1460 | case PRE_INC: |
1461 | case PRE_DEC: | |
1462 | case POST_INC: | |
1463 | case POST_DEC: | |
1464 | case PRE_MODIFY: | |
1465 | case POST_MODIFY: | |
2a2c8203 | 1466 | return find_base_value (XEXP (src, 0)); |
1d300e19 | 1467 | |
0aacc8ed RK |
1468 | case ZERO_EXTEND: |
1469 | case SIGN_EXTEND: /* used for NT/Alpha pointers */ | |
5932a4d4 | 1470 | /* As we do not know which address space the pointer is referring to, we can |
d4ebfa65 BE |
1471 | handle this only if the target does not support different pointer or |
1472 | address modes depending on the address space. */ | |
1473 | if (!target_default_pointer_address_modes_p ()) | |
1474 | break; | |
1475 | ||
0aacc8ed RK |
1476 | { |
1477 | rtx temp = find_base_value (XEXP (src, 0)); | |
1478 | ||
5ae6cd0d | 1479 | if (temp != 0 && CONSTANT_P (temp)) |
0aacc8ed | 1480 | temp = convert_memory_address (Pmode, temp); |
0aacc8ed RK |
1481 | |
1482 | return temp; | |
1483 | } | |
1484 | ||
1d300e19 KG |
1485 | default: |
1486 | break; | |
9ae8ffe7 JL |
1487 | } |
1488 | ||
1489 | return 0; | |
1490 | } | |
1491 | ||
9fc37b2b RS |
1492 | /* Called from init_alias_analysis indirectly through note_stores, |
1493 | or directly if DEST is a register with a REG_NOALIAS note attached. | |
1494 | SET is null in the latter case. */ | |
9ae8ffe7 | 1495 | |
d4b60170 | 1496 | /* While scanning insns to find base values, reg_seen[N] is nonzero if |
9ae8ffe7 | 1497 | register N has been set in this function. */ |
d630245f | 1498 | static sbitmap reg_seen; |
9ae8ffe7 | 1499 | |
2a2c8203 | 1500 | static void |
7bc980e1 | 1501 | record_set (rtx dest, const_rtx set, void *data ATTRIBUTE_UNUSED) |
9ae8ffe7 | 1502 | { |
b3694847 | 1503 | unsigned regno; |
9ae8ffe7 | 1504 | rtx src; |
c28b4e40 | 1505 | int n; |
9ae8ffe7 | 1506 | |
f8cfc6aa | 1507 | if (!REG_P (dest)) |
9ae8ffe7 JL |
1508 | return; |
1509 | ||
fb6754f0 | 1510 | regno = REGNO (dest); |
9ae8ffe7 | 1511 | |
9771b263 | 1512 | gcc_checking_assert (regno < reg_base_value->length ()); |
ac606739 | 1513 | |
dc8afb70 | 1514 | n = REG_NREGS (dest); |
c28b4e40 JW |
1515 | if (n != 1) |
1516 | { | |
1517 | while (--n >= 0) | |
1518 | { | |
d7c028c0 | 1519 | bitmap_set_bit (reg_seen, regno + n); |
c28b4e40 JW |
1520 | new_reg_base_value[regno + n] = 0; |
1521 | } | |
1522 | return; | |
1523 | } | |
1524 | ||
9ae8ffe7 JL |
1525 | if (set) |
1526 | { | |
1527 | /* A CLOBBER wipes out any old value but does not prevent a previously | |
1528 | unset register from acquiring a base address (i.e. reg_seen is not | |
1529 | set). */ | |
1530 | if (GET_CODE (set) == CLOBBER) | |
1531 | { | |
ec907dd8 | 1532 | new_reg_base_value[regno] = 0; |
9ae8ffe7 JL |
1533 | return; |
1534 | } | |
1535 | src = SET_SRC (set); | |
1536 | } | |
1537 | else | |
1538 | { | |
9fc37b2b | 1539 | /* There's a REG_NOALIAS note against DEST. */ |
d7c028c0 | 1540 | if (bitmap_bit_p (reg_seen, regno)) |
9ae8ffe7 | 1541 | { |
ec907dd8 | 1542 | new_reg_base_value[regno] = 0; |
9ae8ffe7 JL |
1543 | return; |
1544 | } | |
d7c028c0 | 1545 | bitmap_set_bit (reg_seen, regno); |
9fc37b2b | 1546 | new_reg_base_value[regno] = unique_base_value (unique_id++); |
9ae8ffe7 JL |
1547 | return; |
1548 | } | |
1549 | ||
5da6f168 RS |
1550 | /* If this is not the first set of REGNO, see whether the new value |
1551 | is related to the old one. There are two cases of interest: | |
1552 | ||
1553 | (1) The register might be assigned an entirely new value | |
1554 | that has the same base term as the original set. | |
1555 | ||
1556 | (2) The set might be a simple self-modification that | |
1557 | cannot change REGNO's base value. | |
1558 | ||
1559 | If neither case holds, reject the original base value as invalid. | |
1560 | Note that the following situation is not detected: | |
1561 | ||
c22cacf3 | 1562 | extern int x, y; int *p = &x; p += (&y-&x); |
5da6f168 | 1563 | |
9ae8ffe7 JL |
1564 | ANSI C does not allow computing the difference of addresses |
1565 | of distinct top level objects. */ | |
5da6f168 RS |
1566 | if (new_reg_base_value[regno] != 0 |
1567 | && find_base_value (src) != new_reg_base_value[regno]) | |
9ae8ffe7 JL |
1568 | switch (GET_CODE (src)) |
1569 | { | |
2a2c8203 | 1570 | case LO_SUM: |
9ae8ffe7 JL |
1571 | case MINUS: |
1572 | if (XEXP (src, 0) != dest && XEXP (src, 1) != dest) | |
ec907dd8 | 1573 | new_reg_base_value[regno] = 0; |
9ae8ffe7 | 1574 | break; |
61f0131c R |
1575 | case PLUS: |
1576 | /* If the value we add in the PLUS is also a valid base value, | |
1577 | this might be the actual base value, and the original value | |
1578 | an index. */ | |
1579 | { | |
1580 | rtx other = NULL_RTX; | |
1581 | ||
1582 | if (XEXP (src, 0) == dest) | |
1583 | other = XEXP (src, 1); | |
1584 | else if (XEXP (src, 1) == dest) | |
1585 | other = XEXP (src, 0); | |
1586 | ||
1587 | if (! other || find_base_value (other)) | |
1588 | new_reg_base_value[regno] = 0; | |
1589 | break; | |
1590 | } | |
9ae8ffe7 | 1591 | case AND: |
481683e1 | 1592 | if (XEXP (src, 0) != dest || !CONST_INT_P (XEXP (src, 1))) |
ec907dd8 | 1593 | new_reg_base_value[regno] = 0; |
9ae8ffe7 | 1594 | break; |
9ae8ffe7 | 1595 | default: |
ec907dd8 | 1596 | new_reg_base_value[regno] = 0; |
9ae8ffe7 JL |
1597 | break; |
1598 | } | |
1599 | /* If this is the first set of a register, record the value. */ | |
1600 | else if ((regno >= FIRST_PSEUDO_REGISTER || ! fixed_regs[regno]) | |
d7c028c0 | 1601 | && ! bitmap_bit_p (reg_seen, regno) && new_reg_base_value[regno] == 0) |
ec907dd8 | 1602 | new_reg_base_value[regno] = find_base_value (src); |
9ae8ffe7 | 1603 | |
d7c028c0 | 1604 | bitmap_set_bit (reg_seen, regno); |
9ae8ffe7 JL |
1605 | } |
1606 | ||
8fd0a474 AM |
1607 | /* Return REG_BASE_VALUE for REGNO. Selective scheduler uses this to avoid |
1608 | using hard registers with non-null REG_BASE_VALUE for renaming. */ | |
1609 | rtx | |
1610 | get_reg_base_value (unsigned int regno) | |
1611 | { | |
9771b263 | 1612 | return (*reg_base_value)[regno]; |
8fd0a474 AM |
1613 | } |
1614 | ||
bb1acb3e RH |
1615 | /* If a value is known for REGNO, return it. */ |
1616 | ||
c22cacf3 | 1617 | rtx |
bb1acb3e RH |
1618 | get_reg_known_value (unsigned int regno) |
1619 | { | |
1620 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1621 | { | |
1622 | regno -= FIRST_PSEUDO_REGISTER; | |
9771b263 DN |
1623 | if (regno < vec_safe_length (reg_known_value)) |
1624 | return (*reg_known_value)[regno]; | |
bb1acb3e RH |
1625 | } |
1626 | return NULL; | |
43fe47ca JW |
1627 | } |
1628 | ||
bb1acb3e RH |
1629 | /* Set it. */ |
1630 | ||
1631 | static void | |
1632 | set_reg_known_value (unsigned int regno, rtx val) | |
1633 | { | |
1634 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1635 | { | |
1636 | regno -= FIRST_PSEUDO_REGISTER; | |
9771b263 DN |
1637 | if (regno < vec_safe_length (reg_known_value)) |
1638 | (*reg_known_value)[regno] = val; | |
bb1acb3e RH |
1639 | } |
1640 | } | |
1641 | ||
1642 | /* Similarly for reg_known_equiv_p. */ | |
1643 | ||
1644 | bool | |
1645 | get_reg_known_equiv_p (unsigned int regno) | |
1646 | { | |
1647 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1648 | { | |
1649 | regno -= FIRST_PSEUDO_REGISTER; | |
9771b263 | 1650 | if (regno < vec_safe_length (reg_known_value)) |
d7c028c0 | 1651 | return bitmap_bit_p (reg_known_equiv_p, regno); |
bb1acb3e RH |
1652 | } |
1653 | return false; | |
1654 | } | |
1655 | ||
1656 | static void | |
1657 | set_reg_known_equiv_p (unsigned int regno, bool val) | |
1658 | { | |
1659 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1660 | { | |
1661 | regno -= FIRST_PSEUDO_REGISTER; | |
9771b263 | 1662 | if (regno < vec_safe_length (reg_known_value)) |
9ff3c7ca SB |
1663 | { |
1664 | if (val) | |
d7c028c0 | 1665 | bitmap_set_bit (reg_known_equiv_p, regno); |
9ff3c7ca | 1666 | else |
d7c028c0 | 1667 | bitmap_clear_bit (reg_known_equiv_p, regno); |
9ff3c7ca | 1668 | } |
bb1acb3e RH |
1669 | } |
1670 | } | |
1671 | ||
1672 | ||
db048faf MM |
1673 | /* Returns a canonical version of X, from the point of view alias |
1674 | analysis. (For example, if X is a MEM whose address is a register, | |
1675 | and the register has a known value (say a SYMBOL_REF), then a MEM | |
1676 | whose address is the SYMBOL_REF is returned.) */ | |
1677 | ||
1678 | rtx | |
4682ae04 | 1679 | canon_rtx (rtx x) |
9ae8ffe7 JL |
1680 | { |
1681 | /* Recursively look for equivalences. */ | |
f8cfc6aa | 1682 | if (REG_P (x) && REGNO (x) >= FIRST_PSEUDO_REGISTER) |
bb1acb3e RH |
1683 | { |
1684 | rtx t = get_reg_known_value (REGNO (x)); | |
1685 | if (t == x) | |
1686 | return x; | |
1687 | if (t) | |
1688 | return canon_rtx (t); | |
1689 | } | |
1690 | ||
1691 | if (GET_CODE (x) == PLUS) | |
9ae8ffe7 JL |
1692 | { |
1693 | rtx x0 = canon_rtx (XEXP (x, 0)); | |
1694 | rtx x1 = canon_rtx (XEXP (x, 1)); | |
1695 | ||
1696 | if (x0 != XEXP (x, 0) || x1 != XEXP (x, 1)) | |
1697 | { | |
481683e1 | 1698 | if (CONST_INT_P (x0)) |
0a81f074 | 1699 | return plus_constant (GET_MODE (x), x1, INTVAL (x0)); |
481683e1 | 1700 | else if (CONST_INT_P (x1)) |
0a81f074 | 1701 | return plus_constant (GET_MODE (x), x0, INTVAL (x1)); |
38a448ca | 1702 | return gen_rtx_PLUS (GET_MODE (x), x0, x1); |
9ae8ffe7 JL |
1703 | } |
1704 | } | |
d4b60170 | 1705 | |
9ae8ffe7 JL |
1706 | /* This gives us much better alias analysis when called from |
1707 | the loop optimizer. Note we want to leave the original | |
1708 | MEM alone, but need to return the canonicalized MEM with | |
1709 | all the flags with their original values. */ | |
3c0cb5de | 1710 | else if (MEM_P (x)) |
f1ec5147 | 1711 | x = replace_equiv_address_nv (x, canon_rtx (XEXP (x, 0))); |
d4b60170 | 1712 | |
9ae8ffe7 JL |
1713 | return x; |
1714 | } | |
1715 | ||
1716 | /* Return 1 if X and Y are identical-looking rtx's. | |
45183e03 | 1717 | Expect that X and Y has been already canonicalized. |
9ae8ffe7 JL |
1718 | |
1719 | We use the data in reg_known_value above to see if two registers with | |
1720 | different numbers are, in fact, equivalent. */ | |
1721 | ||
1722 | static int | |
ed7a4b4b | 1723 | rtx_equal_for_memref_p (const_rtx x, const_rtx y) |
9ae8ffe7 | 1724 | { |
b3694847 SS |
1725 | int i; |
1726 | int j; | |
1727 | enum rtx_code code; | |
1728 | const char *fmt; | |
9ae8ffe7 JL |
1729 | |
1730 | if (x == 0 && y == 0) | |
1731 | return 1; | |
1732 | if (x == 0 || y == 0) | |
1733 | return 0; | |
d4b60170 | 1734 | |
9ae8ffe7 JL |
1735 | if (x == y) |
1736 | return 1; | |
1737 | ||
1738 | code = GET_CODE (x); | |
1739 | /* Rtx's of different codes cannot be equal. */ | |
1740 | if (code != GET_CODE (y)) | |
1741 | return 0; | |
1742 | ||
1743 | /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. | |
1744 | (REG:SI x) and (REG:HI x) are NOT equivalent. */ | |
1745 | ||
1746 | if (GET_MODE (x) != GET_MODE (y)) | |
1747 | return 0; | |
1748 | ||
db048faf MM |
1749 | /* Some RTL can be compared without a recursive examination. */ |
1750 | switch (code) | |
1751 | { | |
1752 | case REG: | |
1753 | return REGNO (x) == REGNO (y); | |
1754 | ||
1755 | case LABEL_REF: | |
a827d9b1 | 1756 | return LABEL_REF_LABEL (x) == LABEL_REF_LABEL (y); |
ca7fd9cd | 1757 | |
db048faf | 1758 | case SYMBOL_REF: |
54363f8a JH |
1759 | { |
1760 | tree x_decl = SYMBOL_REF_DECL (x); | |
1761 | tree y_decl = SYMBOL_REF_DECL (y); | |
1762 | ||
1763 | if (!x_decl || !y_decl) | |
1764 | return XSTR (x, 0) == XSTR (y, 0); | |
1765 | else | |
1766 | return compare_base_decls (x_decl, y_decl) == 1; | |
1767 | } | |
db048faf | 1768 | |
af6236c1 AO |
1769 | case ENTRY_VALUE: |
1770 | /* This is magic, don't go through canonicalization et al. */ | |
1771 | return rtx_equal_p (ENTRY_VALUE_EXP (x), ENTRY_VALUE_EXP (y)); | |
1772 | ||
40e02b4a | 1773 | case VALUE: |
d8116890 | 1774 | CASE_CONST_UNIQUE: |
807e902e | 1775 | /* Pointer equality guarantees equality for these nodes. */ |
db048faf MM |
1776 | return 0; |
1777 | ||
db048faf MM |
1778 | default: |
1779 | break; | |
1780 | } | |
9ae8ffe7 | 1781 | |
45183e03 JH |
1782 | /* canon_rtx knows how to handle plus. No need to canonicalize. */ |
1783 | if (code == PLUS) | |
9ae8ffe7 JL |
1784 | return ((rtx_equal_for_memref_p (XEXP (x, 0), XEXP (y, 0)) |
1785 | && rtx_equal_for_memref_p (XEXP (x, 1), XEXP (y, 1))) | |
1786 | || (rtx_equal_for_memref_p (XEXP (x, 0), XEXP (y, 1)) | |
1787 | && rtx_equal_for_memref_p (XEXP (x, 1), XEXP (y, 0)))); | |
45183e03 JH |
1788 | /* For commutative operations, the RTX match if the operand match in any |
1789 | order. Also handle the simple binary and unary cases without a loop. */ | |
ec8e098d | 1790 | if (COMMUTATIVE_P (x)) |
45183e03 JH |
1791 | { |
1792 | rtx xop0 = canon_rtx (XEXP (x, 0)); | |
1793 | rtx yop0 = canon_rtx (XEXP (y, 0)); | |
1794 | rtx yop1 = canon_rtx (XEXP (y, 1)); | |
1795 | ||
1796 | return ((rtx_equal_for_memref_p (xop0, yop0) | |
1797 | && rtx_equal_for_memref_p (canon_rtx (XEXP (x, 1)), yop1)) | |
1798 | || (rtx_equal_for_memref_p (xop0, yop1) | |
1799 | && rtx_equal_for_memref_p (canon_rtx (XEXP (x, 1)), yop0))); | |
1800 | } | |
ec8e098d | 1801 | else if (NON_COMMUTATIVE_P (x)) |
45183e03 JH |
1802 | { |
1803 | return (rtx_equal_for_memref_p (canon_rtx (XEXP (x, 0)), | |
4682ae04 | 1804 | canon_rtx (XEXP (y, 0))) |
45183e03 JH |
1805 | && rtx_equal_for_memref_p (canon_rtx (XEXP (x, 1)), |
1806 | canon_rtx (XEXP (y, 1)))); | |
1807 | } | |
ec8e098d | 1808 | else if (UNARY_P (x)) |
45183e03 | 1809 | return rtx_equal_for_memref_p (canon_rtx (XEXP (x, 0)), |
4682ae04 | 1810 | canon_rtx (XEXP (y, 0))); |
9ae8ffe7 JL |
1811 | |
1812 | /* Compare the elements. If any pair of corresponding elements | |
de12be17 JC |
1813 | fail to match, return 0 for the whole things. |
1814 | ||
1815 | Limit cases to types which actually appear in addresses. */ | |
9ae8ffe7 JL |
1816 | |
1817 | fmt = GET_RTX_FORMAT (code); | |
1818 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
1819 | { | |
1820 | switch (fmt[i]) | |
1821 | { | |
9ae8ffe7 JL |
1822 | case 'i': |
1823 | if (XINT (x, i) != XINT (y, i)) | |
1824 | return 0; | |
1825 | break; | |
1826 | ||
9ae8ffe7 JL |
1827 | case 'E': |
1828 | /* Two vectors must have the same length. */ | |
1829 | if (XVECLEN (x, i) != XVECLEN (y, i)) | |
1830 | return 0; | |
1831 | ||
1832 | /* And the corresponding elements must match. */ | |
1833 | for (j = 0; j < XVECLEN (x, i); j++) | |
45183e03 JH |
1834 | if (rtx_equal_for_memref_p (canon_rtx (XVECEXP (x, i, j)), |
1835 | canon_rtx (XVECEXP (y, i, j))) == 0) | |
9ae8ffe7 JL |
1836 | return 0; |
1837 | break; | |
1838 | ||
1839 | case 'e': | |
45183e03 JH |
1840 | if (rtx_equal_for_memref_p (canon_rtx (XEXP (x, i)), |
1841 | canon_rtx (XEXP (y, i))) == 0) | |
9ae8ffe7 JL |
1842 | return 0; |
1843 | break; | |
1844 | ||
3237ac18 AH |
1845 | /* This can happen for asm operands. */ |
1846 | case 's': | |
1847 | if (strcmp (XSTR (x, i), XSTR (y, i))) | |
1848 | return 0; | |
1849 | break; | |
1850 | ||
aee21ba9 JL |
1851 | /* This can happen for an asm which clobbers memory. */ |
1852 | case '0': | |
1853 | break; | |
1854 | ||
9ae8ffe7 JL |
1855 | /* It is believed that rtx's at this level will never |
1856 | contain anything but integers and other rtx's, | |
1857 | except for within LABEL_REFs and SYMBOL_REFs. */ | |
1858 | default: | |
298e6adc | 1859 | gcc_unreachable (); |
9ae8ffe7 JL |
1860 | } |
1861 | } | |
1862 | return 1; | |
1863 | } | |
1864 | ||
9e412ca3 | 1865 | static rtx |
4682ae04 | 1866 | find_base_term (rtx x) |
9ae8ffe7 | 1867 | { |
eab5c70a | 1868 | cselib_val *val; |
6f2ffb4b AO |
1869 | struct elt_loc_list *l, *f; |
1870 | rtx ret; | |
eab5c70a | 1871 | |
b949ea8b JW |
1872 | #if defined (FIND_BASE_TERM) |
1873 | /* Try machine-dependent ways to find the base term. */ | |
1874 | x = FIND_BASE_TERM (x); | |
1875 | #endif | |
1876 | ||
9ae8ffe7 JL |
1877 | switch (GET_CODE (x)) |
1878 | { | |
1879 | case REG: | |
1880 | return REG_BASE_VALUE (x); | |
1881 | ||
d288e53d | 1882 | case TRUNCATE: |
5932a4d4 | 1883 | /* As we do not know which address space the pointer is referring to, we can |
d4ebfa65 BE |
1884 | handle this only if the target does not support different pointer or |
1885 | address modes depending on the address space. */ | |
1886 | if (!target_default_pointer_address_modes_p ()) | |
1887 | return 0; | |
d288e53d | 1888 | if (GET_MODE_SIZE (GET_MODE (x)) < GET_MODE_SIZE (Pmode)) |
ca7fd9cd | 1889 | return 0; |
d288e53d | 1890 | /* Fall through. */ |
9ae8ffe7 | 1891 | case HIGH: |
6d849a2a JL |
1892 | case PRE_INC: |
1893 | case PRE_DEC: | |
1894 | case POST_INC: | |
1895 | case POST_DEC: | |
d288e53d DE |
1896 | case PRE_MODIFY: |
1897 | case POST_MODIFY: | |
6d849a2a JL |
1898 | return find_base_term (XEXP (x, 0)); |
1899 | ||
1abade85 RK |
1900 | case ZERO_EXTEND: |
1901 | case SIGN_EXTEND: /* Used for Alpha/NT pointers */ | |
5932a4d4 | 1902 | /* As we do not know which address space the pointer is referring to, we can |
d4ebfa65 BE |
1903 | handle this only if the target does not support different pointer or |
1904 | address modes depending on the address space. */ | |
1905 | if (!target_default_pointer_address_modes_p ()) | |
1906 | return 0; | |
1907 | ||
1abade85 RK |
1908 | { |
1909 | rtx temp = find_base_term (XEXP (x, 0)); | |
1910 | ||
5ae6cd0d | 1911 | if (temp != 0 && CONSTANT_P (temp)) |
1abade85 | 1912 | temp = convert_memory_address (Pmode, temp); |
1abade85 RK |
1913 | |
1914 | return temp; | |
1915 | } | |
1916 | ||
eab5c70a BS |
1917 | case VALUE: |
1918 | val = CSELIB_VAL_PTR (x); | |
6f2ffb4b AO |
1919 | ret = NULL_RTX; |
1920 | ||
40e02b4a | 1921 | if (!val) |
6f2ffb4b AO |
1922 | return ret; |
1923 | ||
0fe03ac3 JJ |
1924 | if (cselib_sp_based_value_p (val)) |
1925 | return static_reg_base_value[STACK_POINTER_REGNUM]; | |
1926 | ||
6f2ffb4b AO |
1927 | f = val->locs; |
1928 | /* Temporarily reset val->locs to avoid infinite recursion. */ | |
1929 | val->locs = NULL; | |
1930 | ||
1931 | for (l = f; l; l = l->next) | |
1932 | if (GET_CODE (l->loc) == VALUE | |
1933 | && CSELIB_VAL_PTR (l->loc)->locs | |
1934 | && !CSELIB_VAL_PTR (l->loc)->locs->next | |
1935 | && CSELIB_VAL_PTR (l->loc)->locs->loc == x) | |
1936 | continue; | |
1937 | else if ((ret = find_base_term (l->loc)) != 0) | |
1938 | break; | |
1939 | ||
1940 | val->locs = f; | |
1941 | return ret; | |
eab5c70a | 1942 | |
023f059b JJ |
1943 | case LO_SUM: |
1944 | /* The standard form is (lo_sum reg sym) so look only at the | |
1945 | second operand. */ | |
1946 | return find_base_term (XEXP (x, 1)); | |
1947 | ||
9ae8ffe7 JL |
1948 | case CONST: |
1949 | x = XEXP (x, 0); | |
1950 | if (GET_CODE (x) != PLUS && GET_CODE (x) != MINUS) | |
1951 | return 0; | |
938d968e | 1952 | /* Fall through. */ |
9ae8ffe7 JL |
1953 | case PLUS: |
1954 | case MINUS: | |
1955 | { | |
3c567fae JL |
1956 | rtx tmp1 = XEXP (x, 0); |
1957 | rtx tmp2 = XEXP (x, 1); | |
1958 | ||
f5143c46 | 1959 | /* This is a little bit tricky since we have to determine which of |
3c567fae JL |
1960 | the two operands represents the real base address. Otherwise this |
1961 | routine may return the index register instead of the base register. | |
1962 | ||
1963 | That may cause us to believe no aliasing was possible, when in | |
1964 | fact aliasing is possible. | |
1965 | ||
1966 | We use a few simple tests to guess the base register. Additional | |
1967 | tests can certainly be added. For example, if one of the operands | |
1968 | is a shift or multiply, then it must be the index register and the | |
1969 | other operand is the base register. */ | |
ca7fd9cd | 1970 | |
b949ea8b JW |
1971 | if (tmp1 == pic_offset_table_rtx && CONSTANT_P (tmp2)) |
1972 | return find_base_term (tmp2); | |
1973 | ||
31b0a960 | 1974 | /* If either operand is known to be a pointer, then prefer it |
3c567fae | 1975 | to determine the base term. */ |
3502dc9c | 1976 | if (REG_P (tmp1) && REG_POINTER (tmp1)) |
31b0a960 RB |
1977 | ; |
1978 | else if (REG_P (tmp2) && REG_POINTER (tmp2)) | |
a7c75343 JJ |
1979 | std::swap (tmp1, tmp2); |
1980 | /* If second argument is constant which has base term, prefer it | |
1981 | over variable tmp1. See PR64025. */ | |
1982 | else if (CONSTANT_P (tmp2) && !CONST_INT_P (tmp2)) | |
1983 | std::swap (tmp1, tmp2); | |
3c567fae | 1984 | |
31b0a960 RB |
1985 | /* Go ahead and find the base term for both operands. If either base |
1986 | term is from a pointer or is a named object or a special address | |
3c567fae JL |
1987 | (like an argument or stack reference), then use it for the |
1988 | base term. */ | |
481be1c4 RB |
1989 | rtx base = find_base_term (tmp1); |
1990 | if (base != NULL_RTX | |
31b0a960 | 1991 | && ((REG_P (tmp1) && REG_POINTER (tmp1)) |
481be1c4 RB |
1992 | || known_base_value_p (base))) |
1993 | return base; | |
1994 | base = find_base_term (tmp2); | |
1995 | if (base != NULL_RTX | |
31b0a960 | 1996 | && ((REG_P (tmp2) && REG_POINTER (tmp2)) |
481be1c4 RB |
1997 | || known_base_value_p (base))) |
1998 | return base; | |
3c567fae JL |
1999 | |
2000 | /* We could not determine which of the two operands was the | |
2001 | base register and which was the index. So we can determine | |
2002 | nothing from the base alias check. */ | |
2003 | return 0; | |
9ae8ffe7 JL |
2004 | } |
2005 | ||
2006 | case AND: | |
481683e1 | 2007 | if (CONST_INT_P (XEXP (x, 1)) && INTVAL (XEXP (x, 1)) != 0) |
d288e53d | 2008 | return find_base_term (XEXP (x, 0)); |
9ae8ffe7 JL |
2009 | return 0; |
2010 | ||
2011 | case SYMBOL_REF: | |
2012 | case LABEL_REF: | |
2013 | return x; | |
2014 | ||
2015 | default: | |
2016 | return 0; | |
2017 | } | |
2018 | } | |
2019 | ||
9e412ca3 RS |
2020 | /* Return true if accesses to address X may alias accesses based |
2021 | on the stack pointer. */ | |
2022 | ||
2023 | bool | |
2024 | may_be_sp_based_p (rtx x) | |
2025 | { | |
2026 | rtx base = find_base_term (x); | |
2027 | return !base || base == static_reg_base_value[STACK_POINTER_REGNUM]; | |
2028 | } | |
2029 | ||
54363f8a JH |
2030 | /* BASE1 and BASE2 are decls. Return 1 if they refer to same object, 0 |
2031 | if they refer to different objects and -1 if we can not decide. */ | |
2032 | ||
2033 | int | |
2034 | compare_base_decls (tree base1, tree base2) | |
2035 | { | |
2036 | int ret; | |
2037 | gcc_checking_assert (DECL_P (base1) && DECL_P (base2)); | |
2038 | if (base1 == base2) | |
2039 | return 1; | |
2040 | ||
54363f8a JH |
2041 | /* Declarations of non-automatic variables may have aliases. All other |
2042 | decls are unique. */ | |
7ec4f343 NS |
2043 | if (!decl_in_symtab_p (base1) |
2044 | || !decl_in_symtab_p (base2)) | |
54363f8a | 2045 | return 0; |
7ec4f343 | 2046 | |
54363f8a JH |
2047 | ret = symtab_node::get_create (base1)->equal_address_to |
2048 | (symtab_node::get_create (base2), true); | |
2049 | if (ret == 2) | |
2050 | return -1; | |
2051 | return ret; | |
2052 | } | |
2053 | ||
9ae8ffe7 JL |
2054 | /* Return 0 if the addresses X and Y are known to point to different |
2055 | objects, 1 if they might be pointers to the same object. */ | |
2056 | ||
2057 | static int | |
31b0a960 | 2058 | base_alias_check (rtx x, rtx x_base, rtx y, rtx y_base, |
ef4bddc2 | 2059 | machine_mode x_mode, machine_mode y_mode) |
9ae8ffe7 | 2060 | { |
1c72c7f6 JC |
2061 | /* If the address itself has no known base see if a known equivalent |
2062 | value has one. If either address still has no known base, nothing | |
2063 | is known about aliasing. */ | |
2064 | if (x_base == 0) | |
2065 | { | |
2066 | rtx x_c; | |
d4b60170 | 2067 | |
1c72c7f6 JC |
2068 | if (! flag_expensive_optimizations || (x_c = canon_rtx (x)) == x) |
2069 | return 1; | |
d4b60170 | 2070 | |
1c72c7f6 JC |
2071 | x_base = find_base_term (x_c); |
2072 | if (x_base == 0) | |
2073 | return 1; | |
2074 | } | |
9ae8ffe7 | 2075 | |
1c72c7f6 JC |
2076 | if (y_base == 0) |
2077 | { | |
2078 | rtx y_c; | |
2079 | if (! flag_expensive_optimizations || (y_c = canon_rtx (y)) == y) | |
2080 | return 1; | |
d4b60170 | 2081 | |
1c72c7f6 JC |
2082 | y_base = find_base_term (y_c); |
2083 | if (y_base == 0) | |
2084 | return 1; | |
2085 | } | |
2086 | ||
2087 | /* If the base addresses are equal nothing is known about aliasing. */ | |
2088 | if (rtx_equal_p (x_base, y_base)) | |
9ae8ffe7 JL |
2089 | return 1; |
2090 | ||
54363f8a JH |
2091 | if (GET_CODE (x_base) == SYMBOL_REF && GET_CODE (y_base) == SYMBOL_REF) |
2092 | { | |
2093 | tree x_decl = SYMBOL_REF_DECL (x_base); | |
2094 | tree y_decl = SYMBOL_REF_DECL (y_base); | |
2095 | ||
2096 | /* We can assume that no stores are made to labels. */ | |
2097 | if (!x_decl || !y_decl) | |
2098 | return 0; | |
2099 | return compare_base_decls (x_decl, y_decl) != 0; | |
2100 | } | |
2101 | ||
435da628 UB |
2102 | /* The base addresses are different expressions. If they are not accessed |
2103 | via AND, there is no conflict. We can bring knowledge of object | |
2104 | alignment into play here. For example, on alpha, "char a, b;" can | |
2105 | alias one another, though "char a; long b;" cannot. AND addesses may | |
2106 | implicitly alias surrounding objects; i.e. unaligned access in DImode | |
2107 | via AND address can alias all surrounding object types except those | |
2108 | with aligment 8 or higher. */ | |
2109 | if (GET_CODE (x) == AND && GET_CODE (y) == AND) | |
2110 | return 1; | |
2111 | if (GET_CODE (x) == AND | |
481683e1 | 2112 | && (!CONST_INT_P (XEXP (x, 1)) |
435da628 UB |
2113 | || (int) GET_MODE_UNIT_SIZE (y_mode) < -INTVAL (XEXP (x, 1)))) |
2114 | return 1; | |
2115 | if (GET_CODE (y) == AND | |
481683e1 | 2116 | && (!CONST_INT_P (XEXP (y, 1)) |
435da628 UB |
2117 | || (int) GET_MODE_UNIT_SIZE (x_mode) < -INTVAL (XEXP (y, 1)))) |
2118 | return 1; | |
2119 | ||
2120 | /* Differing symbols not accessed via AND never alias. */ | |
9ae8ffe7 | 2121 | if (GET_CODE (x_base) != ADDRESS && GET_CODE (y_base) != ADDRESS) |
435da628 | 2122 | return 0; |
9ae8ffe7 | 2123 | |
9fc37b2b | 2124 | if (unique_base_value_p (x_base) || unique_base_value_p (y_base)) |
9ae8ffe7 JL |
2125 | return 0; |
2126 | ||
0d3c82d6 | 2127 | return 1; |
9ae8ffe7 JL |
2128 | } |
2129 | ||
a5628378 | 2130 | /* Return TRUE if EXPR refers to a VALUE whose uid is greater than |
c779924e | 2131 | (or equal to) that of V. */ |
a5628378 AO |
2132 | |
2133 | static bool | |
403837b4 | 2134 | refs_newer_value_p (const_rtx expr, rtx v) |
a5628378 AO |
2135 | { |
2136 | int minuid = CSELIB_VAL_PTR (v)->uid; | |
403837b4 RS |
2137 | subrtx_iterator::array_type array; |
2138 | FOR_EACH_SUBRTX (iter, array, expr, NONCONST) | |
c779924e | 2139 | if (GET_CODE (*iter) == VALUE && CSELIB_VAL_PTR (*iter)->uid >= minuid) |
403837b4 RS |
2140 | return true; |
2141 | return false; | |
a5628378 AO |
2142 | } |
2143 | ||
eab5c70a BS |
2144 | /* Convert the address X into something we can use. This is done by returning |
2145 | it unchanged unless it is a value; in the latter case we call cselib to get | |
2146 | a more useful rtx. */ | |
3bdf5ad1 | 2147 | |
a13d4ebf | 2148 | rtx |
4682ae04 | 2149 | get_addr (rtx x) |
eab5c70a BS |
2150 | { |
2151 | cselib_val *v; | |
2152 | struct elt_loc_list *l; | |
2153 | ||
2154 | if (GET_CODE (x) != VALUE) | |
2155 | return x; | |
2156 | v = CSELIB_VAL_PTR (x); | |
40e02b4a JH |
2157 | if (v) |
2158 | { | |
0f68ba3e AO |
2159 | bool have_equivs = cselib_have_permanent_equivalences (); |
2160 | if (have_equivs) | |
2161 | v = canonical_cselib_val (v); | |
40e02b4a JH |
2162 | for (l = v->locs; l; l = l->next) |
2163 | if (CONSTANT_P (l->loc)) | |
2164 | return l->loc; | |
2165 | for (l = v->locs; l; l = l->next) | |
0f68ba3e AO |
2166 | if (!REG_P (l->loc) && !MEM_P (l->loc) |
2167 | /* Avoid infinite recursion when potentially dealing with | |
2168 | var-tracking artificial equivalences, by skipping the | |
2169 | equivalences themselves, and not choosing expressions | |
2170 | that refer to newer VALUEs. */ | |
2171 | && (!have_equivs | |
2172 | || (GET_CODE (l->loc) != VALUE | |
2173 | && !refs_newer_value_p (l->loc, x)))) | |
a5628378 | 2174 | return l->loc; |
0f68ba3e AO |
2175 | if (have_equivs) |
2176 | { | |
2177 | for (l = v->locs; l; l = l->next) | |
2178 | if (REG_P (l->loc) | |
2179 | || (GET_CODE (l->loc) != VALUE | |
2180 | && !refs_newer_value_p (l->loc, x))) | |
2181 | return l->loc; | |
2182 | /* Return the canonical value. */ | |
2183 | return v->val_rtx; | |
2184 | } | |
2185 | if (v->locs) | |
2186 | return v->locs->loc; | |
40e02b4a | 2187 | } |
eab5c70a BS |
2188 | return x; |
2189 | } | |
2190 | ||
39cec1ac MH |
2191 | /* Return the address of the (N_REFS + 1)th memory reference to ADDR |
2192 | where SIZE is the size in bytes of the memory reference. If ADDR | |
2193 | is not modified by the memory reference then ADDR is returned. */ | |
2194 | ||
04e2b4d3 | 2195 | static rtx |
4682ae04 | 2196 | addr_side_effect_eval (rtx addr, int size, int n_refs) |
39cec1ac MH |
2197 | { |
2198 | int offset = 0; | |
ca7fd9cd | 2199 | |
39cec1ac MH |
2200 | switch (GET_CODE (addr)) |
2201 | { | |
2202 | case PRE_INC: | |
2203 | offset = (n_refs + 1) * size; | |
2204 | break; | |
2205 | case PRE_DEC: | |
2206 | offset = -(n_refs + 1) * size; | |
2207 | break; | |
2208 | case POST_INC: | |
2209 | offset = n_refs * size; | |
2210 | break; | |
2211 | case POST_DEC: | |
2212 | offset = -n_refs * size; | |
2213 | break; | |
2214 | ||
2215 | default: | |
2216 | return addr; | |
2217 | } | |
ca7fd9cd | 2218 | |
39cec1ac | 2219 | if (offset) |
45183e03 | 2220 | addr = gen_rtx_PLUS (GET_MODE (addr), XEXP (addr, 0), |
4789c0ce | 2221 | gen_int_mode (offset, GET_MODE (addr))); |
39cec1ac MH |
2222 | else |
2223 | addr = XEXP (addr, 0); | |
45183e03 | 2224 | addr = canon_rtx (addr); |
39cec1ac MH |
2225 | |
2226 | return addr; | |
2227 | } | |
2228 | ||
3aa03517 AO |
2229 | /* Return TRUE if an object X sized at XSIZE bytes and another object |
2230 | Y sized at YSIZE bytes, starting C bytes after X, may overlap. If | |
2231 | any of the sizes is zero, assume an overlap, otherwise use the | |
2232 | absolute value of the sizes as the actual sizes. */ | |
2233 | ||
2234 | static inline bool | |
2235 | offset_overlap_p (HOST_WIDE_INT c, int xsize, int ysize) | |
2236 | { | |
2237 | return (xsize == 0 || ysize == 0 | |
2238 | || (c >= 0 | |
2239 | ? (abs (xsize) > c) | |
2240 | : (abs (ysize) > -c))); | |
2241 | } | |
2242 | ||
f47e08d9 RG |
2243 | /* Return one if X and Y (memory addresses) reference the |
2244 | same location in memory or if the references overlap. | |
2245 | Return zero if they do not overlap, else return | |
2246 | minus one in which case they still might reference the same location. | |
2247 | ||
2248 | C is an offset accumulator. When | |
9ae8ffe7 JL |
2249 | C is nonzero, we are testing aliases between X and Y + C. |
2250 | XSIZE is the size in bytes of the X reference, | |
2251 | similarly YSIZE is the size in bytes for Y. | |
45183e03 | 2252 | Expect that canon_rtx has been already called for X and Y. |
9ae8ffe7 JL |
2253 | |
2254 | If XSIZE or YSIZE is zero, we do not know the amount of memory being | |
2255 | referenced (the reference was BLKmode), so make the most pessimistic | |
2256 | assumptions. | |
2257 | ||
c02f035f RH |
2258 | If XSIZE or YSIZE is negative, we may access memory outside the object |
2259 | being referenced as a side effect. This can happen when using AND to | |
2260 | align memory references, as is done on the Alpha. | |
2261 | ||
9ae8ffe7 | 2262 | Nice to notice that varying addresses cannot conflict with fp if no |
f47e08d9 RG |
2263 | local variables had their addresses taken, but that's too hard now. |
2264 | ||
2265 | ??? Contrary to the tree alias oracle this does not return | |
2266 | one for X + non-constant and Y + non-constant when X and Y are equal. | |
2267 | If that is fixed the TBAA hack for union type-punning can be removed. */ | |
9ae8ffe7 | 2268 | |
9ae8ffe7 | 2269 | static int |
4682ae04 | 2270 | memrefs_conflict_p (int xsize, rtx x, int ysize, rtx y, HOST_WIDE_INT c) |
9ae8ffe7 | 2271 | { |
eab5c70a | 2272 | if (GET_CODE (x) == VALUE) |
5312b066 JJ |
2273 | { |
2274 | if (REG_P (y)) | |
2275 | { | |
24f8d71e JJ |
2276 | struct elt_loc_list *l = NULL; |
2277 | if (CSELIB_VAL_PTR (x)) | |
a5628378 AO |
2278 | for (l = canonical_cselib_val (CSELIB_VAL_PTR (x))->locs; |
2279 | l; l = l->next) | |
24f8d71e JJ |
2280 | if (REG_P (l->loc) && rtx_equal_for_memref_p (l->loc, y)) |
2281 | break; | |
5312b066 JJ |
2282 | if (l) |
2283 | x = y; | |
2284 | else | |
2285 | x = get_addr (x); | |
2286 | } | |
2287 | /* Don't call get_addr if y is the same VALUE. */ | |
2288 | else if (x != y) | |
2289 | x = get_addr (x); | |
2290 | } | |
eab5c70a | 2291 | if (GET_CODE (y) == VALUE) |
5312b066 JJ |
2292 | { |
2293 | if (REG_P (x)) | |
2294 | { | |
24f8d71e JJ |
2295 | struct elt_loc_list *l = NULL; |
2296 | if (CSELIB_VAL_PTR (y)) | |
a5628378 AO |
2297 | for (l = canonical_cselib_val (CSELIB_VAL_PTR (y))->locs; |
2298 | l; l = l->next) | |
24f8d71e JJ |
2299 | if (REG_P (l->loc) && rtx_equal_for_memref_p (l->loc, x)) |
2300 | break; | |
5312b066 JJ |
2301 | if (l) |
2302 | y = x; | |
2303 | else | |
2304 | y = get_addr (y); | |
2305 | } | |
2306 | /* Don't call get_addr if x is the same VALUE. */ | |
2307 | else if (y != x) | |
2308 | y = get_addr (y); | |
2309 | } | |
9ae8ffe7 JL |
2310 | if (GET_CODE (x) == HIGH) |
2311 | x = XEXP (x, 0); | |
2312 | else if (GET_CODE (x) == LO_SUM) | |
2313 | x = XEXP (x, 1); | |
2314 | else | |
3aa03517 | 2315 | x = addr_side_effect_eval (x, abs (xsize), 0); |
9ae8ffe7 JL |
2316 | if (GET_CODE (y) == HIGH) |
2317 | y = XEXP (y, 0); | |
2318 | else if (GET_CODE (y) == LO_SUM) | |
2319 | y = XEXP (y, 1); | |
2320 | else | |
3aa03517 | 2321 | y = addr_side_effect_eval (y, abs (ysize), 0); |
9ae8ffe7 | 2322 | |
54363f8a JH |
2323 | if (GET_CODE (x) == SYMBOL_REF && GET_CODE (y) == SYMBOL_REF) |
2324 | { | |
2325 | tree x_decl = SYMBOL_REF_DECL (x); | |
2326 | tree y_decl = SYMBOL_REF_DECL (y); | |
2327 | int cmp; | |
2328 | ||
2329 | if (!x_decl || !y_decl) | |
2330 | { | |
2331 | /* Label and normal symbol are never the same. */ | |
2332 | if (x_decl != y_decl) | |
2333 | return 0; | |
2334 | return offset_overlap_p (c, xsize, ysize); | |
2335 | } | |
2336 | else | |
2337 | cmp = compare_base_decls (x_decl, y_decl); | |
2338 | ||
2339 | /* If both decls are the same, decide by offsets. */ | |
2340 | if (cmp == 1) | |
2341 | return offset_overlap_p (c, xsize, ysize); | |
2342 | /* If decls are different or we know by offsets that there is no overlap, | |
2343 | we win. */ | |
2344 | if (!cmp || !offset_overlap_p (c, xsize, ysize)) | |
2345 | return 0; | |
2346 | /* Decls may or may not be different and offsets overlap....*/ | |
2347 | return -1; | |
2348 | } | |
2349 | else if (rtx_equal_for_memref_p (x, y)) | |
9ae8ffe7 | 2350 | { |
3aa03517 | 2351 | return offset_overlap_p (c, xsize, ysize); |
9ae8ffe7 JL |
2352 | } |
2353 | ||
6e73e666 JC |
2354 | /* This code used to check for conflicts involving stack references and |
2355 | globals but the base address alias code now handles these cases. */ | |
9ae8ffe7 JL |
2356 | |
2357 | if (GET_CODE (x) == PLUS) | |
2358 | { | |
2359 | /* The fact that X is canonicalized means that this | |
2360 | PLUS rtx is canonicalized. */ | |
2361 | rtx x0 = XEXP (x, 0); | |
2362 | rtx x1 = XEXP (x, 1); | |
2363 | ||
2d88904a AO |
2364 | /* However, VALUEs might end up in different positions even in |
2365 | canonical PLUSes. Comparing their addresses is enough. */ | |
2366 | if (x0 == y) | |
2367 | return memrefs_conflict_p (xsize, x1, ysize, const0_rtx, c); | |
2368 | else if (x1 == y) | |
2369 | return memrefs_conflict_p (xsize, x0, ysize, const0_rtx, c); | |
2370 | ||
9ae8ffe7 JL |
2371 | if (GET_CODE (y) == PLUS) |
2372 | { | |
2373 | /* The fact that Y is canonicalized means that this | |
2374 | PLUS rtx is canonicalized. */ | |
2375 | rtx y0 = XEXP (y, 0); | |
2376 | rtx y1 = XEXP (y, 1); | |
2377 | ||
2d88904a AO |
2378 | if (x0 == y1) |
2379 | return memrefs_conflict_p (xsize, x1, ysize, y0, c); | |
2380 | if (x1 == y0) | |
2381 | return memrefs_conflict_p (xsize, x0, ysize, y1, c); | |
2382 | ||
9ae8ffe7 JL |
2383 | if (rtx_equal_for_memref_p (x1, y1)) |
2384 | return memrefs_conflict_p (xsize, x0, ysize, y0, c); | |
2385 | if (rtx_equal_for_memref_p (x0, y0)) | |
2386 | return memrefs_conflict_p (xsize, x1, ysize, y1, c); | |
481683e1 | 2387 | if (CONST_INT_P (x1)) |
63be02db | 2388 | { |
481683e1 | 2389 | if (CONST_INT_P (y1)) |
63be02db JM |
2390 | return memrefs_conflict_p (xsize, x0, ysize, y0, |
2391 | c - INTVAL (x1) + INTVAL (y1)); | |
2392 | else | |
2393 | return memrefs_conflict_p (xsize, x0, ysize, y, | |
2394 | c - INTVAL (x1)); | |
2395 | } | |
481683e1 | 2396 | else if (CONST_INT_P (y1)) |
9ae8ffe7 JL |
2397 | return memrefs_conflict_p (xsize, x, ysize, y0, c + INTVAL (y1)); |
2398 | ||
f47e08d9 | 2399 | return -1; |
9ae8ffe7 | 2400 | } |
481683e1 | 2401 | else if (CONST_INT_P (x1)) |
9ae8ffe7 JL |
2402 | return memrefs_conflict_p (xsize, x0, ysize, y, c - INTVAL (x1)); |
2403 | } | |
2404 | else if (GET_CODE (y) == PLUS) | |
2405 | { | |
2406 | /* The fact that Y is canonicalized means that this | |
2407 | PLUS rtx is canonicalized. */ | |
2408 | rtx y0 = XEXP (y, 0); | |
2409 | rtx y1 = XEXP (y, 1); | |
2410 | ||
2d88904a AO |
2411 | if (x == y0) |
2412 | return memrefs_conflict_p (xsize, const0_rtx, ysize, y1, c); | |
2413 | if (x == y1) | |
2414 | return memrefs_conflict_p (xsize, const0_rtx, ysize, y0, c); | |
2415 | ||
481683e1 | 2416 | if (CONST_INT_P (y1)) |
9ae8ffe7 JL |
2417 | return memrefs_conflict_p (xsize, x, ysize, y0, c + INTVAL (y1)); |
2418 | else | |
f47e08d9 | 2419 | return -1; |
9ae8ffe7 JL |
2420 | } |
2421 | ||
2422 | if (GET_CODE (x) == GET_CODE (y)) | |
2423 | switch (GET_CODE (x)) | |
2424 | { | |
2425 | case MULT: | |
2426 | { | |
2427 | /* Handle cases where we expect the second operands to be the | |
2428 | same, and check only whether the first operand would conflict | |
2429 | or not. */ | |
2430 | rtx x0, y0; | |
2431 | rtx x1 = canon_rtx (XEXP (x, 1)); | |
2432 | rtx y1 = canon_rtx (XEXP (y, 1)); | |
2433 | if (! rtx_equal_for_memref_p (x1, y1)) | |
f47e08d9 | 2434 | return -1; |
9ae8ffe7 JL |
2435 | x0 = canon_rtx (XEXP (x, 0)); |
2436 | y0 = canon_rtx (XEXP (y, 0)); | |
2437 | if (rtx_equal_for_memref_p (x0, y0)) | |
3aa03517 | 2438 | return offset_overlap_p (c, xsize, ysize); |
9ae8ffe7 JL |
2439 | |
2440 | /* Can't properly adjust our sizes. */ | |
481683e1 | 2441 | if (!CONST_INT_P (x1)) |
f47e08d9 | 2442 | return -1; |
9ae8ffe7 JL |
2443 | xsize /= INTVAL (x1); |
2444 | ysize /= INTVAL (x1); | |
2445 | c /= INTVAL (x1); | |
2446 | return memrefs_conflict_p (xsize, x0, ysize, y0, c); | |
2447 | } | |
1d300e19 KG |
2448 | |
2449 | default: | |
2450 | break; | |
9ae8ffe7 JL |
2451 | } |
2452 | ||
a9bf4fe2 AO |
2453 | /* Deal with alignment ANDs by adjusting offset and size so as to |
2454 | cover the maximum range, without taking any previously known | |
5147bf6a AO |
2455 | alignment into account. Make a size negative after such an |
2456 | adjustments, so that, if we end up with e.g. two SYMBOL_REFs, we | |
2457 | assume a potential overlap, because they may end up in contiguous | |
2458 | memory locations and the stricter-alignment access may span over | |
2459 | part of both. */ | |
481683e1 | 2460 | if (GET_CODE (x) == AND && CONST_INT_P (XEXP (x, 1))) |
56ee9281 | 2461 | { |
a9bf4fe2 AO |
2462 | HOST_WIDE_INT sc = INTVAL (XEXP (x, 1)); |
2463 | unsigned HOST_WIDE_INT uc = sc; | |
5147bf6a | 2464 | if (sc < 0 && -uc == (uc & -uc)) |
a9bf4fe2 | 2465 | { |
5147bf6a AO |
2466 | if (xsize > 0) |
2467 | xsize = -xsize; | |
3aa03517 AO |
2468 | if (xsize) |
2469 | xsize += sc + 1; | |
fe8fb1c4 | 2470 | c -= sc + 1; |
a9bf4fe2 AO |
2471 | return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)), |
2472 | ysize, y, c); | |
2473 | } | |
56ee9281 | 2474 | } |
481683e1 | 2475 | if (GET_CODE (y) == AND && CONST_INT_P (XEXP (y, 1))) |
c02f035f | 2476 | { |
a9bf4fe2 AO |
2477 | HOST_WIDE_INT sc = INTVAL (XEXP (y, 1)); |
2478 | unsigned HOST_WIDE_INT uc = sc; | |
5147bf6a | 2479 | if (sc < 0 && -uc == (uc & -uc)) |
a9bf4fe2 | 2480 | { |
5147bf6a AO |
2481 | if (ysize > 0) |
2482 | ysize = -ysize; | |
3aa03517 AO |
2483 | if (ysize) |
2484 | ysize += sc + 1; | |
fe8fb1c4 | 2485 | c += sc + 1; |
a9bf4fe2 AO |
2486 | return memrefs_conflict_p (xsize, x, |
2487 | ysize, canon_rtx (XEXP (y, 0)), c); | |
2488 | } | |
c02f035f | 2489 | } |
9ae8ffe7 JL |
2490 | |
2491 | if (CONSTANT_P (x)) | |
2492 | { | |
481683e1 | 2493 | if (CONST_INT_P (x) && CONST_INT_P (y)) |
9ae8ffe7 JL |
2494 | { |
2495 | c += (INTVAL (y) - INTVAL (x)); | |
3aa03517 | 2496 | return offset_overlap_p (c, xsize, ysize); |
9ae8ffe7 JL |
2497 | } |
2498 | ||
2499 | if (GET_CODE (x) == CONST) | |
2500 | { | |
2501 | if (GET_CODE (y) == CONST) | |
2502 | return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)), | |
2503 | ysize, canon_rtx (XEXP (y, 0)), c); | |
2504 | else | |
2505 | return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)), | |
2506 | ysize, y, c); | |
2507 | } | |
2508 | if (GET_CODE (y) == CONST) | |
2509 | return memrefs_conflict_p (xsize, x, ysize, | |
2510 | canon_rtx (XEXP (y, 0)), c); | |
2511 | ||
3aa03517 AO |
2512 | /* Assume a potential overlap for symbolic addresses that went |
2513 | through alignment adjustments (i.e., that have negative | |
2514 | sizes), because we can't know how far they are from each | |
2515 | other. */ | |
9ae8ffe7 | 2516 | if (CONSTANT_P (y)) |
3aa03517 | 2517 | return (xsize < 0 || ysize < 0 || offset_overlap_p (c, xsize, ysize)); |
9ae8ffe7 | 2518 | |
f47e08d9 | 2519 | return -1; |
9ae8ffe7 | 2520 | } |
f47e08d9 RG |
2521 | |
2522 | return -1; | |
9ae8ffe7 JL |
2523 | } |
2524 | ||
2525 | /* Functions to compute memory dependencies. | |
2526 | ||
2527 | Since we process the insns in execution order, we can build tables | |
2528 | to keep track of what registers are fixed (and not aliased), what registers | |
2529 | are varying in known ways, and what registers are varying in unknown | |
2530 | ways. | |
2531 | ||
2532 | If both memory references are volatile, then there must always be a | |
2533 | dependence between the two references, since their order can not be | |
2534 | changed. A volatile and non-volatile reference can be interchanged | |
ca7fd9cd | 2535 | though. |
9ae8ffe7 | 2536 | |
53d9622b RS |
2537 | We also must allow AND addresses, because they may generate accesses |
2538 | outside the object being referenced. This is used to generate aligned | |
2539 | addresses from unaligned addresses, for instance, the alpha | |
dc1618bc | 2540 | storeqi_unaligned pattern. */ |
9ae8ffe7 JL |
2541 | |
2542 | /* Read dependence: X is read after read in MEM takes place. There can | |
96672a3e RH |
2543 | only be a dependence here if both reads are volatile, or if either is |
2544 | an explicit barrier. */ | |
9ae8ffe7 JL |
2545 | |
2546 | int | |
4f588890 | 2547 | read_dependence (const_rtx mem, const_rtx x) |
9ae8ffe7 | 2548 | { |
96672a3e RH |
2549 | if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) |
2550 | return true; | |
2551 | if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER | |
2552 | || MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER) | |
2553 | return true; | |
2554 | return false; | |
9ae8ffe7 JL |
2555 | } |
2556 | ||
998d7deb RH |
2557 | /* Look at the bottom of the COMPONENT_REF list for a DECL, and return it. */ |
2558 | ||
2559 | static tree | |
4682ae04 | 2560 | decl_for_component_ref (tree x) |
998d7deb RH |
2561 | { |
2562 | do | |
2563 | { | |
2564 | x = TREE_OPERAND (x, 0); | |
2565 | } | |
2566 | while (x && TREE_CODE (x) == COMPONENT_REF); | |
2567 | ||
2568 | return x && DECL_P (x) ? x : NULL_TREE; | |
2569 | } | |
2570 | ||
527210c4 RS |
2571 | /* Walk up the COMPONENT_REF list in X and adjust *OFFSET to compensate |
2572 | for the offset of the field reference. *KNOWN_P says whether the | |
2573 | offset is known. */ | |
998d7deb | 2574 | |
527210c4 RS |
2575 | static void |
2576 | adjust_offset_for_component_ref (tree x, bool *known_p, | |
2577 | HOST_WIDE_INT *offset) | |
998d7deb | 2578 | { |
527210c4 RS |
2579 | if (!*known_p) |
2580 | return; | |
ca7fd9cd | 2581 | do |
998d7deb | 2582 | { |
527210c4 | 2583 | tree xoffset = component_ref_field_offset (x); |
998d7deb | 2584 | tree field = TREE_OPERAND (x, 1); |
807e902e KZ |
2585 | if (TREE_CODE (xoffset) != INTEGER_CST) |
2586 | { | |
2587 | *known_p = false; | |
2588 | return; | |
2589 | } | |
998d7deb | 2590 | |
807e902e KZ |
2591 | offset_int woffset |
2592 | = (wi::to_offset (xoffset) | |
2593 | + wi::lrshift (wi::to_offset (DECL_FIELD_BIT_OFFSET (field)), | |
2594 | LOG2_BITS_PER_UNIT)); | |
2595 | if (!wi::fits_uhwi_p (woffset)) | |
527210c4 RS |
2596 | { |
2597 | *known_p = false; | |
2598 | return; | |
2599 | } | |
807e902e | 2600 | *offset += woffset.to_uhwi (); |
998d7deb RH |
2601 | |
2602 | x = TREE_OPERAND (x, 0); | |
2603 | } | |
2604 | while (x && TREE_CODE (x) == COMPONENT_REF); | |
998d7deb RH |
2605 | } |
2606 | ||
95bd1dd7 | 2607 | /* Return nonzero if we can determine the exprs corresponding to memrefs |
c6ea834c BM |
2608 | X and Y and they do not overlap. |
2609 | If LOOP_VARIANT is set, skip offset-based disambiguation */ | |
a4311dfe | 2610 | |
2e4e39f6 | 2611 | int |
c6ea834c | 2612 | nonoverlapping_memrefs_p (const_rtx x, const_rtx y, bool loop_invariant) |
a4311dfe | 2613 | { |
998d7deb | 2614 | tree exprx = MEM_EXPR (x), expry = MEM_EXPR (y); |
a4311dfe RK |
2615 | rtx rtlx, rtly; |
2616 | rtx basex, basey; | |
527210c4 RS |
2617 | bool moffsetx_known_p, moffsety_known_p; |
2618 | HOST_WIDE_INT moffsetx = 0, moffsety = 0; | |
4e1952ab | 2619 | HOST_WIDE_INT offsetx = 0, offsety = 0, sizex, sizey; |
a4311dfe | 2620 | |
998d7deb RH |
2621 | /* Unless both have exprs, we can't tell anything. */ |
2622 | if (exprx == 0 || expry == 0) | |
2623 | return 0; | |
2b22e382 RG |
2624 | |
2625 | /* For spill-slot accesses make sure we have valid offsets. */ | |
2626 | if ((exprx == get_spill_slot_decl (false) | |
527210c4 | 2627 | && ! MEM_OFFSET_KNOWN_P (x)) |
2b22e382 | 2628 | || (expry == get_spill_slot_decl (false) |
527210c4 | 2629 | && ! MEM_OFFSET_KNOWN_P (y))) |
2b22e382 | 2630 | return 0; |
c22cacf3 | 2631 | |
998d7deb | 2632 | /* If the field reference test failed, look at the DECLs involved. */ |
527210c4 RS |
2633 | moffsetx_known_p = MEM_OFFSET_KNOWN_P (x); |
2634 | if (moffsetx_known_p) | |
2635 | moffsetx = MEM_OFFSET (x); | |
998d7deb RH |
2636 | if (TREE_CODE (exprx) == COMPONENT_REF) |
2637 | { | |
2e0c984c RG |
2638 | tree t = decl_for_component_ref (exprx); |
2639 | if (! t) | |
2640 | return 0; | |
527210c4 | 2641 | adjust_offset_for_component_ref (exprx, &moffsetx_known_p, &moffsetx); |
2e0c984c | 2642 | exprx = t; |
998d7deb | 2643 | } |
c67a1cf6 | 2644 | |
527210c4 RS |
2645 | moffsety_known_p = MEM_OFFSET_KNOWN_P (y); |
2646 | if (moffsety_known_p) | |
2647 | moffsety = MEM_OFFSET (y); | |
998d7deb RH |
2648 | if (TREE_CODE (expry) == COMPONENT_REF) |
2649 | { | |
2e0c984c RG |
2650 | tree t = decl_for_component_ref (expry); |
2651 | if (! t) | |
2652 | return 0; | |
527210c4 | 2653 | adjust_offset_for_component_ref (expry, &moffsety_known_p, &moffsety); |
2e0c984c | 2654 | expry = t; |
998d7deb RH |
2655 | } |
2656 | ||
2657 | if (! DECL_P (exprx) || ! DECL_P (expry)) | |
a4311dfe RK |
2658 | return 0; |
2659 | ||
1f9ceff1 AO |
2660 | /* If we refer to different gimple registers, or one gimple register |
2661 | and one non-gimple-register, we know they can't overlap. First, | |
2662 | gimple registers don't have their addresses taken. Now, there | |
2663 | could be more than one stack slot for (different versions of) the | |
2664 | same gimple register, but we can presumably tell they don't | |
2665 | overlap based on offsets from stack base addresses elsewhere. | |
2666 | It's important that we don't proceed to DECL_RTL, because gimple | |
2667 | registers may not pass DECL_RTL_SET_P, and make_decl_rtl won't be | |
2668 | able to do anything about them since no SSA information will have | |
2669 | remained to guide it. */ | |
2670 | if (is_gimple_reg (exprx) || is_gimple_reg (expry)) | |
2d88904a AO |
2671 | return exprx != expry |
2672 | || (moffsetx_known_p && moffsety_known_p | |
2673 | && MEM_SIZE_KNOWN_P (x) && MEM_SIZE_KNOWN_P (y) | |
2674 | && !offset_overlap_p (moffsety - moffsetx, | |
2675 | MEM_SIZE (x), MEM_SIZE (y))); | |
1f9ceff1 | 2676 | |
1307c758 RG |
2677 | /* With invalid code we can end up storing into the constant pool. |
2678 | Bail out to avoid ICEing when creating RTL for this. | |
2679 | See gfortran.dg/lto/20091028-2_0.f90. */ | |
2680 | if (TREE_CODE (exprx) == CONST_DECL | |
2681 | || TREE_CODE (expry) == CONST_DECL) | |
2682 | return 1; | |
2683 | ||
998d7deb RH |
2684 | rtlx = DECL_RTL (exprx); |
2685 | rtly = DECL_RTL (expry); | |
a4311dfe | 2686 | |
1edcd60b RK |
2687 | /* If either RTL is not a MEM, it must be a REG or CONCAT, meaning they |
2688 | can't overlap unless they are the same because we never reuse that part | |
2689 | of the stack frame used for locals for spilled pseudos. */ | |
3c0cb5de | 2690 | if ((!MEM_P (rtlx) || !MEM_P (rtly)) |
1edcd60b | 2691 | && ! rtx_equal_p (rtlx, rtly)) |
a4311dfe RK |
2692 | return 1; |
2693 | ||
5932a4d4 | 2694 | /* If we have MEMs referring to different address spaces (which can |
09e881c9 BE |
2695 | potentially overlap), we cannot easily tell from the addresses |
2696 | whether the references overlap. */ | |
2697 | if (MEM_P (rtlx) && MEM_P (rtly) | |
2698 | && MEM_ADDR_SPACE (rtlx) != MEM_ADDR_SPACE (rtly)) | |
2699 | return 0; | |
2700 | ||
a4311dfe RK |
2701 | /* Get the base and offsets of both decls. If either is a register, we |
2702 | know both are and are the same, so use that as the base. The only | |
2703 | we can avoid overlap is if we can deduce that they are nonoverlapping | |
2704 | pieces of that decl, which is very rare. */ | |
3c0cb5de | 2705 | basex = MEM_P (rtlx) ? XEXP (rtlx, 0) : rtlx; |
481683e1 | 2706 | if (GET_CODE (basex) == PLUS && CONST_INT_P (XEXP (basex, 1))) |
a4311dfe RK |
2707 | offsetx = INTVAL (XEXP (basex, 1)), basex = XEXP (basex, 0); |
2708 | ||
3c0cb5de | 2709 | basey = MEM_P (rtly) ? XEXP (rtly, 0) : rtly; |
481683e1 | 2710 | if (GET_CODE (basey) == PLUS && CONST_INT_P (XEXP (basey, 1))) |
a4311dfe RK |
2711 | offsety = INTVAL (XEXP (basey, 1)), basey = XEXP (basey, 0); |
2712 | ||
d746694a | 2713 | /* If the bases are different, we know they do not overlap if both |
ca7fd9cd | 2714 | are constants or if one is a constant and the other a pointer into the |
d746694a RK |
2715 | stack frame. Otherwise a different base means we can't tell if they |
2716 | overlap or not. */ | |
54363f8a | 2717 | if (compare_base_decls (exprx, expry) == 0) |
ca7fd9cd KH |
2718 | return ((CONSTANT_P (basex) && CONSTANT_P (basey)) |
2719 | || (CONSTANT_P (basex) && REG_P (basey) | |
2720 | && REGNO_PTR_FRAME_P (REGNO (basey))) | |
2721 | || (CONSTANT_P (basey) && REG_P (basex) | |
2722 | && REGNO_PTR_FRAME_P (REGNO (basex)))); | |
a4311dfe | 2723 | |
c6ea834c BM |
2724 | /* Offset based disambiguation not appropriate for loop invariant */ |
2725 | if (loop_invariant) | |
2726 | return 0; | |
2727 | ||
54363f8a JH |
2728 | /* Offset based disambiguation is OK even if we do not know that the |
2729 | declarations are necessarily different | |
2730 | (i.e. compare_base_decls (exprx, expry) == -1) */ | |
2731 | ||
3c0cb5de | 2732 | sizex = (!MEM_P (rtlx) ? (int) GET_MODE_SIZE (GET_MODE (rtlx)) |
f5541398 | 2733 | : MEM_SIZE_KNOWN_P (rtlx) ? MEM_SIZE (rtlx) |
a4311dfe | 2734 | : -1); |
3c0cb5de | 2735 | sizey = (!MEM_P (rtly) ? (int) GET_MODE_SIZE (GET_MODE (rtly)) |
f5541398 RS |
2736 | : MEM_SIZE_KNOWN_P (rtly) ? MEM_SIZE (rtly) |
2737 | : -1); | |
a4311dfe | 2738 | |
0af5bc3e RK |
2739 | /* If we have an offset for either memref, it can update the values computed |
2740 | above. */ | |
527210c4 RS |
2741 | if (moffsetx_known_p) |
2742 | offsetx += moffsetx, sizex -= moffsetx; | |
2743 | if (moffsety_known_p) | |
2744 | offsety += moffsety, sizey -= moffsety; | |
a4311dfe | 2745 | |
0af5bc3e | 2746 | /* If a memref has both a size and an offset, we can use the smaller size. |
efc981bb | 2747 | We can't do this if the offset isn't known because we must view this |
0af5bc3e | 2748 | memref as being anywhere inside the DECL's MEM. */ |
527210c4 | 2749 | if (MEM_SIZE_KNOWN_P (x) && moffsetx_known_p) |
f5541398 | 2750 | sizex = MEM_SIZE (x); |
527210c4 | 2751 | if (MEM_SIZE_KNOWN_P (y) && moffsety_known_p) |
f5541398 | 2752 | sizey = MEM_SIZE (y); |
a4311dfe RK |
2753 | |
2754 | /* Put the values of the memref with the lower offset in X's values. */ | |
2755 | if (offsetx > offsety) | |
2756 | { | |
4e1952ab KT |
2757 | std::swap (offsetx, offsety); |
2758 | std::swap (sizex, sizey); | |
a4311dfe RK |
2759 | } |
2760 | ||
2761 | /* If we don't know the size of the lower-offset value, we can't tell | |
2762 | if they conflict. Otherwise, we do the test. */ | |
a6f7c915 | 2763 | return sizex >= 0 && offsety >= offsetx + sizex; |
a4311dfe RK |
2764 | } |
2765 | ||
9362286d SB |
2766 | /* Helper for true_dependence and canon_true_dependence. |
2767 | Checks for true dependence: X is read after store in MEM takes place. | |
9ae8ffe7 | 2768 | |
9362286d SB |
2769 | If MEM_CANONICALIZED is FALSE, then X_ADDR and MEM_ADDR should be |
2770 | NULL_RTX, and the canonical addresses of MEM and X are both computed | |
2771 | here. If MEM_CANONICALIZED, then MEM must be already canonicalized. | |
2772 | ||
2773 | If X_ADDR is non-NULL, it is used in preference of XEXP (x, 0). | |
2774 | ||
2775 | Returns 1 if there is a true dependence, 0 otherwise. */ | |
2776 | ||
2777 | static int | |
ef4bddc2 | 2778 | true_dependence_1 (const_rtx mem, machine_mode mem_mode, rtx mem_addr, |
53d9622b | 2779 | const_rtx x, rtx x_addr, bool mem_canonicalized) |
9ae8ffe7 | 2780 | { |
0777fc02 | 2781 | rtx true_mem_addr; |
49982682 | 2782 | rtx base; |
f47e08d9 | 2783 | int ret; |
9ae8ffe7 | 2784 | |
9362286d SB |
2785 | gcc_checking_assert (mem_canonicalized ? (mem_addr != NULL_RTX) |
2786 | : (mem_addr == NULL_RTX && x_addr == NULL_RTX)); | |
2787 | ||
9ae8ffe7 JL |
2788 | if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) |
2789 | return 1; | |
2790 | ||
c4484b8f | 2791 | /* (mem:BLK (scratch)) is a special mechanism to conflict with everything. |
ac3768f6 | 2792 | This is used in epilogue deallocation functions, and in cselib. */ |
c4484b8f RH |
2793 | if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH) |
2794 | return 1; | |
2795 | if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH) | |
2796 | return 1; | |
9cd9e512 RH |
2797 | if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER |
2798 | || MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER) | |
2799 | return 1; | |
c4484b8f | 2800 | |
0777fc02 UB |
2801 | if (! x_addr) |
2802 | x_addr = XEXP (x, 0); | |
2803 | x_addr = get_addr (x_addr); | |
2804 | ||
9362286d SB |
2805 | if (! mem_addr) |
2806 | { | |
2807 | mem_addr = XEXP (mem, 0); | |
2808 | if (mem_mode == VOIDmode) | |
2809 | mem_mode = GET_MODE (mem); | |
2810 | } | |
0777fc02 | 2811 | true_mem_addr = get_addr (mem_addr); |
eab5c70a | 2812 | |
878f5596 UB |
2813 | /* Read-only memory is by definition never modified, and therefore can't |
2814 | conflict with anything. However, don't assume anything when AND | |
2815 | addresses are involved and leave to the code below to determine | |
2816 | dependence. We don't expect to find read-only set on MEM, but | |
2817 | stupid user tricks can produce them, so don't die. */ | |
2818 | if (MEM_READONLY_P (x) | |
2819 | && GET_CODE (x_addr) != AND | |
0777fc02 | 2820 | && GET_CODE (true_mem_addr) != AND) |
878f5596 UB |
2821 | return 0; |
2822 | ||
2823 | /* If we have MEMs referring to different address spaces (which can | |
2824 | potentially overlap), we cannot easily tell from the addresses | |
2825 | whether the references overlap. */ | |
2826 | if (MEM_ADDR_SPACE (mem) != MEM_ADDR_SPACE (x)) | |
2827 | return 1; | |
2828 | ||
55efb413 JW |
2829 | base = find_base_term (x_addr); |
2830 | if (base && (GET_CODE (base) == LABEL_REF | |
2831 | || (GET_CODE (base) == SYMBOL_REF | |
2832 | && CONSTANT_POOL_ADDRESS_P (base)))) | |
2833 | return 0; | |
2834 | ||
0777fc02 UB |
2835 | rtx mem_base = find_base_term (true_mem_addr); |
2836 | if (! base_alias_check (x_addr, base, true_mem_addr, mem_base, | |
31b0a960 | 2837 | GET_MODE (x), mem_mode)) |
1c72c7f6 JC |
2838 | return 0; |
2839 | ||
eab5c70a | 2840 | x_addr = canon_rtx (x_addr); |
9362286d | 2841 | if (!mem_canonicalized) |
0777fc02 | 2842 | mem_addr = canon_rtx (true_mem_addr); |
6e73e666 | 2843 | |
f47e08d9 RG |
2844 | if ((ret = memrefs_conflict_p (GET_MODE_SIZE (mem_mode), mem_addr, |
2845 | SIZE_FOR_MODE (x), x_addr, 0)) != -1) | |
2846 | return ret; | |
2847 | ||
a95b3cc7 | 2848 | if (mems_in_disjoint_alias_sets_p (x, mem)) |
f47e08d9 RG |
2849 | return 0; |
2850 | ||
c6ea834c | 2851 | if (nonoverlapping_memrefs_p (mem, x, false)) |
0211b6ab | 2852 | return 0; |
175a7536 | 2853 | |
55b34b5f | 2854 | return rtx_refs_may_alias_p (x, mem, true); |
a13d4ebf AM |
2855 | } |
2856 | ||
9362286d SB |
2857 | /* True dependence: X is read after store in MEM takes place. */ |
2858 | ||
2859 | int | |
ef4bddc2 | 2860 | true_dependence (const_rtx mem, machine_mode mem_mode, const_rtx x) |
9362286d SB |
2861 | { |
2862 | return true_dependence_1 (mem, mem_mode, NULL_RTX, | |
53d9622b | 2863 | x, NULL_RTX, /*mem_canonicalized=*/false); |
9362286d SB |
2864 | } |
2865 | ||
a13d4ebf | 2866 | /* Canonical true dependence: X is read after store in MEM takes place. |
ca7fd9cd KH |
2867 | Variant of true_dependence which assumes MEM has already been |
2868 | canonicalized (hence we no longer do that here). | |
9362286d SB |
2869 | The mem_addr argument has been added, since true_dependence_1 computed |
2870 | this value prior to canonicalizing. */ | |
a13d4ebf AM |
2871 | |
2872 | int | |
ef4bddc2 | 2873 | canon_true_dependence (const_rtx mem, machine_mode mem_mode, rtx mem_addr, |
53d9622b | 2874 | const_rtx x, rtx x_addr) |
a13d4ebf | 2875 | { |
9362286d | 2876 | return true_dependence_1 (mem, mem_mode, mem_addr, |
53d9622b | 2877 | x, x_addr, /*mem_canonicalized=*/true); |
9ae8ffe7 JL |
2878 | } |
2879 | ||
da7d8304 | 2880 | /* Returns nonzero if a write to X might alias a previous read from |
393f9fed | 2881 | (or, if WRITEP is true, a write to) MEM. |
bd280792 JR |
2882 | If X_CANONCALIZED is true, then X_ADDR is the canonicalized address of X, |
2883 | and X_MODE the mode for that access. | |
2884 | If MEM_CANONICALIZED is true, MEM is canonicalized. */ | |
9ae8ffe7 | 2885 | |
2c72b78f | 2886 | static int |
bd280792 | 2887 | write_dependence_p (const_rtx mem, |
ef4bddc2 | 2888 | const_rtx x, machine_mode x_mode, rtx x_addr, |
bd280792 | 2889 | bool mem_canonicalized, bool x_canonicalized, bool writep) |
9ae8ffe7 | 2890 | { |
bd280792 | 2891 | rtx mem_addr; |
0777fc02 | 2892 | rtx true_mem_addr, true_x_addr; |
49982682 | 2893 | rtx base; |
f47e08d9 | 2894 | int ret; |
6e73e666 | 2895 | |
bd280792 JR |
2896 | gcc_checking_assert (x_canonicalized |
2897 | ? (x_addr != NULL_RTX && x_mode != VOIDmode) | |
2898 | : (x_addr == NULL_RTX && x_mode == VOIDmode)); | |
393f9fed | 2899 | |
9ae8ffe7 JL |
2900 | if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) |
2901 | return 1; | |
2902 | ||
c4484b8f RH |
2903 | /* (mem:BLK (scratch)) is a special mechanism to conflict with everything. |
2904 | This is used in epilogue deallocation functions. */ | |
2905 | if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH) | |
2906 | return 1; | |
2907 | if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH) | |
2908 | return 1; | |
9cd9e512 RH |
2909 | if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER |
2910 | || MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER) | |
2911 | return 1; | |
c4484b8f | 2912 | |
bd280792 | 2913 | if (!x_addr) |
0777fc02 UB |
2914 | x_addr = XEXP (x, 0); |
2915 | true_x_addr = get_addr (x_addr); | |
2916 | ||
2917 | mem_addr = XEXP (mem, 0); | |
2918 | true_mem_addr = get_addr (mem_addr); | |
55efb413 | 2919 | |
878f5596 UB |
2920 | /* A read from read-only memory can't conflict with read-write memory. |
2921 | Don't assume anything when AND addresses are involved and leave to | |
2922 | the code below to determine dependence. */ | |
2923 | if (!writep | |
2924 | && MEM_READONLY_P (mem) | |
0777fc02 UB |
2925 | && GET_CODE (true_x_addr) != AND |
2926 | && GET_CODE (true_mem_addr) != AND) | |
878f5596 UB |
2927 | return 0; |
2928 | ||
2929 | /* If we have MEMs referring to different address spaces (which can | |
2930 | potentially overlap), we cannot easily tell from the addresses | |
2931 | whether the references overlap. */ | |
2932 | if (MEM_ADDR_SPACE (mem) != MEM_ADDR_SPACE (x)) | |
2933 | return 1; | |
2934 | ||
0777fc02 | 2935 | base = find_base_term (true_mem_addr); |
31b0a960 RB |
2936 | if (! writep |
2937 | && base | |
2938 | && (GET_CODE (base) == LABEL_REF | |
2939 | || (GET_CODE (base) == SYMBOL_REF | |
2940 | && CONSTANT_POOL_ADDRESS_P (base)))) | |
2941 | return 0; | |
49982682 | 2942 | |
0777fc02 UB |
2943 | rtx x_base = find_base_term (true_x_addr); |
2944 | if (! base_alias_check (true_x_addr, x_base, true_mem_addr, base, | |
2945 | GET_MODE (x), GET_MODE (mem))) | |
41472af8 MM |
2946 | return 0; |
2947 | ||
bd280792 | 2948 | if (!x_canonicalized) |
393f9fed | 2949 | { |
0777fc02 | 2950 | x_addr = canon_rtx (true_x_addr); |
bd280792 | 2951 | x_mode = GET_MODE (x); |
393f9fed | 2952 | } |
bd280792 | 2953 | if (!mem_canonicalized) |
0777fc02 | 2954 | mem_addr = canon_rtx (true_mem_addr); |
6e73e666 | 2955 | |
bd280792 JR |
2956 | if ((ret = memrefs_conflict_p (SIZE_FOR_MODE (mem), mem_addr, |
2957 | GET_MODE_SIZE (x_mode), x_addr, 0)) != -1) | |
f47e08d9 RG |
2958 | return ret; |
2959 | ||
c6ea834c | 2960 | if (nonoverlapping_memrefs_p (x, mem, false)) |
c6df88cb MM |
2961 | return 0; |
2962 | ||
55b34b5f | 2963 | return rtx_refs_may_alias_p (x, mem, false); |
c6df88cb MM |
2964 | } |
2965 | ||
2966 | /* Anti dependence: X is written after read in MEM takes place. */ | |
2967 | ||
2968 | int | |
4f588890 | 2969 | anti_dependence (const_rtx mem, const_rtx x) |
c6df88cb | 2970 | { |
bd280792 JR |
2971 | return write_dependence_p (mem, x, VOIDmode, NULL_RTX, |
2972 | /*mem_canonicalized=*/false, | |
2973 | /*x_canonicalized*/false, /*writep=*/false); | |
393f9fed JR |
2974 | } |
2975 | ||
bd280792 JR |
2976 | /* Likewise, but we already have a canonicalized MEM, and X_ADDR for X. |
2977 | Also, consider X in X_MODE (which might be from an enclosing | |
2978 | STRICT_LOW_PART / ZERO_EXTRACT). | |
2979 | If MEM_CANONICALIZED is true, MEM is canonicalized. */ | |
393f9fed JR |
2980 | |
2981 | int | |
bd280792 | 2982 | canon_anti_dependence (const_rtx mem, bool mem_canonicalized, |
ef4bddc2 | 2983 | const_rtx x, machine_mode x_mode, rtx x_addr) |
393f9fed | 2984 | { |
bd280792 JR |
2985 | return write_dependence_p (mem, x, x_mode, x_addr, |
2986 | mem_canonicalized, /*x_canonicalized=*/true, | |
2987 | /*writep=*/false); | |
9ae8ffe7 JL |
2988 | } |
2989 | ||
2990 | /* Output dependence: X is written after store in MEM takes place. */ | |
2991 | ||
2992 | int | |
4f588890 | 2993 | output_dependence (const_rtx mem, const_rtx x) |
9ae8ffe7 | 2994 | { |
bd280792 JR |
2995 | return write_dependence_p (mem, x, VOIDmode, NULL_RTX, |
2996 | /*mem_canonicalized=*/false, | |
2997 | /*x_canonicalized*/false, /*writep=*/true); | |
9ae8ffe7 | 2998 | } |
c14b9960 | 2999 | \f |
6e73e666 | 3000 | |
c6ea834c BM |
3001 | |
3002 | /* Check whether X may be aliased with MEM. Don't do offset-based | |
3003 | memory disambiguation & TBAA. */ | |
3004 | int | |
3005 | may_alias_p (const_rtx mem, const_rtx x) | |
3006 | { | |
3007 | rtx x_addr, mem_addr; | |
c6ea834c BM |
3008 | |
3009 | if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) | |
3010 | return 1; | |
3011 | ||
a95b3cc7 RG |
3012 | /* (mem:BLK (scratch)) is a special mechanism to conflict with everything. |
3013 | This is used in epilogue deallocation functions. */ | |
3014 | if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH) | |
3015 | return 1; | |
3016 | if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH) | |
c6ea834c | 3017 | return 1; |
c6ea834c BM |
3018 | if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER |
3019 | || MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER) | |
3020 | return 1; | |
3021 | ||
c6ea834c | 3022 | x_addr = XEXP (x, 0); |
0777fc02 UB |
3023 | x_addr = get_addr (x_addr); |
3024 | ||
c6ea834c | 3025 | mem_addr = XEXP (mem, 0); |
0777fc02 | 3026 | mem_addr = get_addr (mem_addr); |
c6ea834c | 3027 | |
878f5596 UB |
3028 | /* Read-only memory is by definition never modified, and therefore can't |
3029 | conflict with anything. However, don't assume anything when AND | |
3030 | addresses are involved and leave to the code below to determine | |
3031 | dependence. We don't expect to find read-only set on MEM, but | |
3032 | stupid user tricks can produce them, so don't die. */ | |
3033 | if (MEM_READONLY_P (x) | |
3034 | && GET_CODE (x_addr) != AND | |
3035 | && GET_CODE (mem_addr) != AND) | |
3036 | return 0; | |
3037 | ||
3038 | /* If we have MEMs referring to different address spaces (which can | |
3039 | potentially overlap), we cannot easily tell from the addresses | |
3040 | whether the references overlap. */ | |
3041 | if (MEM_ADDR_SPACE (mem) != MEM_ADDR_SPACE (x)) | |
3042 | return 1; | |
3043 | ||
31b0a960 RB |
3044 | rtx x_base = find_base_term (x_addr); |
3045 | rtx mem_base = find_base_term (mem_addr); | |
3046 | if (! base_alias_check (x_addr, x_base, mem_addr, mem_base, | |
3047 | GET_MODE (x), GET_MODE (mem_addr))) | |
c6ea834c BM |
3048 | return 0; |
3049 | ||
c6ea834c BM |
3050 | if (nonoverlapping_memrefs_p (mem, x, true)) |
3051 | return 0; | |
3052 | ||
c6ea834c BM |
3053 | /* TBAA not valid for loop_invarint */ |
3054 | return rtx_refs_may_alias_p (x, mem, false); | |
3055 | } | |
3056 | ||
6e73e666 | 3057 | void |
b5deb7b6 | 3058 | init_alias_target (void) |
6e73e666 | 3059 | { |
b3694847 | 3060 | int i; |
6e73e666 | 3061 | |
9fc37b2b RS |
3062 | if (!arg_base_value) |
3063 | arg_base_value = gen_rtx_ADDRESS (VOIDmode, 0); | |
3064 | ||
b5deb7b6 SL |
3065 | memset (static_reg_base_value, 0, sizeof static_reg_base_value); |
3066 | ||
6e73e666 JC |
3067 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) |
3068 | /* Check whether this register can hold an incoming pointer | |
3069 | argument. FUNCTION_ARG_REGNO_P tests outgoing register | |
ec5c56db | 3070 | numbers, so translate if necessary due to register windows. */ |
6e73e666 JC |
3071 | if (FUNCTION_ARG_REGNO_P (OUTGOING_REGNO (i)) |
3072 | && HARD_REGNO_MODE_OK (i, Pmode)) | |
9fc37b2b RS |
3073 | static_reg_base_value[i] = arg_base_value; |
3074 | ||
757e8ba2 JJ |
3075 | static_reg_base_value[STACK_POINTER_REGNUM] |
3076 | = unique_base_value (UNIQUE_BASE_VALUE_SP); | |
3077 | static_reg_base_value[ARG_POINTER_REGNUM] | |
3078 | = unique_base_value (UNIQUE_BASE_VALUE_ARGP); | |
3079 | static_reg_base_value[FRAME_POINTER_REGNUM] | |
3080 | = unique_base_value (UNIQUE_BASE_VALUE_FP); | |
c3e08036 TS |
3081 | if (!HARD_FRAME_POINTER_IS_FRAME_POINTER) |
3082 | static_reg_base_value[HARD_FRAME_POINTER_REGNUM] | |
3083 | = unique_base_value (UNIQUE_BASE_VALUE_HFP); | |
bf1660a6 JL |
3084 | } |
3085 | ||
7b52eede JH |
3086 | /* Set MEMORY_MODIFIED when X modifies DATA (that is assumed |
3087 | to be memory reference. */ | |
3088 | static bool memory_modified; | |
3089 | static void | |
aa317c97 | 3090 | memory_modified_1 (rtx x, const_rtx pat ATTRIBUTE_UNUSED, void *data) |
7b52eede | 3091 | { |
3c0cb5de | 3092 | if (MEM_P (x)) |
7b52eede | 3093 | { |
9678086d | 3094 | if (anti_dependence (x, (const_rtx)data) || output_dependence (x, (const_rtx)data)) |
7b52eede JH |
3095 | memory_modified = true; |
3096 | } | |
3097 | } | |
3098 | ||
3099 | ||
3100 | /* Return true when INSN possibly modify memory contents of MEM | |
454ff5cb | 3101 | (i.e. address can be modified). */ |
7b52eede | 3102 | bool |
9678086d | 3103 | memory_modified_in_insn_p (const_rtx mem, const_rtx insn) |
7b52eede JH |
3104 | { |
3105 | if (!INSN_P (insn)) | |
3106 | return false; | |
3107 | memory_modified = false; | |
aa317c97 | 3108 | note_stores (PATTERN (insn), memory_modified_1, CONST_CAST_RTX(mem)); |
7b52eede JH |
3109 | return memory_modified; |
3110 | } | |
3111 | ||
a7b159a4 AH |
3112 | /* Return TRUE if the destination of a set is rtx identical to |
3113 | ITEM. */ | |
3114 | static inline bool | |
3115 | set_dest_equal_p (const_rtx set, const_rtx item) | |
3116 | { | |
3117 | rtx dest = SET_DEST (set); | |
3118 | return rtx_equal_p (dest, item); | |
3119 | } | |
3120 | ||
c13e8210 MM |
3121 | /* Initialize the aliasing machinery. Initialize the REG_KNOWN_VALUE |
3122 | array. */ | |
3123 | ||
9ae8ffe7 | 3124 | void |
4682ae04 | 3125 | init_alias_analysis (void) |
9ae8ffe7 | 3126 | { |
c582d54a | 3127 | unsigned int maxreg = max_reg_num (); |
ea64ef27 | 3128 | int changed, pass; |
b3694847 SS |
3129 | int i; |
3130 | unsigned int ui; | |
d36a28b8 DM |
3131 | rtx_insn *insn; |
3132 | rtx val; | |
131db6b8 SB |
3133 | int rpo_cnt; |
3134 | int *rpo; | |
9ae8ffe7 | 3135 | |
0d446150 JH |
3136 | timevar_push (TV_ALIAS_ANALYSIS); |
3137 | ||
92390dd1 | 3138 | vec_safe_grow_cleared (reg_known_value, maxreg - FIRST_PSEUDO_REGISTER); |
9ff3c7ca | 3139 | reg_known_equiv_p = sbitmap_alloc (maxreg - FIRST_PSEUDO_REGISTER); |
dd3d1ec0 | 3140 | bitmap_clear (reg_known_equiv_p); |
9ae8ffe7 | 3141 | |
08c79682 | 3142 | /* If we have memory allocated from the previous run, use it. */ |
c582d54a | 3143 | if (old_reg_base_value) |
08c79682 KH |
3144 | reg_base_value = old_reg_base_value; |
3145 | ||
3146 | if (reg_base_value) | |
9771b263 | 3147 | reg_base_value->truncate (0); |
08c79682 | 3148 | |
9771b263 | 3149 | vec_safe_grow_cleared (reg_base_value, maxreg); |
ac606739 | 3150 | |
5ed6ace5 | 3151 | new_reg_base_value = XNEWVEC (rtx, maxreg); |
d630245f | 3152 | reg_seen = sbitmap_alloc (maxreg); |
ec907dd8 JL |
3153 | |
3154 | /* The basic idea is that each pass through this loop will use the | |
3155 | "constant" information from the previous pass to propagate alias | |
3156 | information through another level of assignments. | |
3157 | ||
131db6b8 SB |
3158 | The propagation is done on the CFG in reverse post-order, to propagate |
3159 | things forward as far as possible in each iteration. | |
3160 | ||
ec907dd8 JL |
3161 | This could get expensive if the assignment chains are long. Maybe |
3162 | we should throttle the number of iterations, possibly based on | |
6e73e666 | 3163 | the optimization level or flag_expensive_optimizations. |
ec907dd8 JL |
3164 | |
3165 | We could propagate more information in the first pass by making use | |
6fb5fa3c | 3166 | of DF_REG_DEF_COUNT to determine immediately that the alias information |
ea64ef27 JL |
3167 | for a pseudo is "constant". |
3168 | ||
3169 | A program with an uninitialized variable can cause an infinite loop | |
3170 | here. Instead of doing a full dataflow analysis to detect such problems | |
3171 | we just cap the number of iterations for the loop. | |
3172 | ||
3173 | The state of the arrays for the set chain in question does not matter | |
3174 | since the program has undefined behavior. */ | |
6e73e666 | 3175 | |
0cae8d31 | 3176 | rpo = XNEWVEC (int, n_basic_blocks_for_fn (cfun)); |
131db6b8 SB |
3177 | rpo_cnt = pre_and_rev_post_order_compute (NULL, rpo, false); |
3178 | ||
e86a9946 RS |
3179 | /* The prologue/epilogue insns are not threaded onto the |
3180 | insn chain until after reload has completed. Thus, | |
3181 | there is no sense wasting time checking if INSN is in | |
3182 | the prologue/epilogue until after reload has completed. */ | |
3183 | bool could_be_prologue_epilogue = ((targetm.have_prologue () | |
3184 | || targetm.have_epilogue ()) | |
3185 | && reload_completed); | |
3186 | ||
ea64ef27 | 3187 | pass = 0; |
6e73e666 | 3188 | do |
ec907dd8 JL |
3189 | { |
3190 | /* Assume nothing will change this iteration of the loop. */ | |
3191 | changed = 0; | |
3192 | ||
ec907dd8 | 3193 | /* We want to assign the same IDs each iteration of this loop, so |
9fc37b2b RS |
3194 | start counting from one each iteration of the loop. */ |
3195 | unique_id = 1; | |
ec907dd8 | 3196 | |
f5143c46 | 3197 | /* We're at the start of the function each iteration through the |
ec907dd8 | 3198 | loop, so we're copying arguments. */ |
83bbd9b6 | 3199 | copying_arguments = true; |
9ae8ffe7 | 3200 | |
6e73e666 | 3201 | /* Wipe the potential alias information clean for this pass. */ |
c582d54a | 3202 | memset (new_reg_base_value, 0, maxreg * sizeof (rtx)); |
8072f69c | 3203 | |
6e73e666 | 3204 | /* Wipe the reg_seen array clean. */ |
f61e445a | 3205 | bitmap_clear (reg_seen); |
9ae8ffe7 | 3206 | |
356610cb EB |
3207 | /* Initialize the alias information for this pass. */ |
3208 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
3209 | if (static_reg_base_value[i]) | |
3210 | { | |
3211 | new_reg_base_value[i] = static_reg_base_value[i]; | |
3212 | bitmap_set_bit (reg_seen, i); | |
3213 | } | |
6e73e666 | 3214 | |
ec907dd8 | 3215 | /* Walk the insns adding values to the new_reg_base_value array. */ |
131db6b8 | 3216 | for (i = 0; i < rpo_cnt; i++) |
9ae8ffe7 | 3217 | { |
06e28de2 | 3218 | basic_block bb = BASIC_BLOCK_FOR_FN (cfun, rpo[i]); |
131db6b8 | 3219 | FOR_BB_INSNS (bb, insn) |
ec907dd8 | 3220 | { |
131db6b8 SB |
3221 | if (NONDEBUG_INSN_P (insn)) |
3222 | { | |
3223 | rtx note, set; | |
efc9bd41 | 3224 | |
e86a9946 | 3225 | if (could_be_prologue_epilogue |
131db6b8 SB |
3226 | && prologue_epilogue_contains (insn)) |
3227 | continue; | |
efc9bd41 | 3228 | |
131db6b8 SB |
3229 | /* If this insn has a noalias note, process it, Otherwise, |
3230 | scan for sets. A simple set will have no side effects | |
3231 | which could change the base value of any other register. */ | |
6e73e666 | 3232 | |
131db6b8 SB |
3233 | if (GET_CODE (PATTERN (insn)) == SET |
3234 | && REG_NOTES (insn) != 0 | |
3235 | && find_reg_note (insn, REG_NOALIAS, NULL_RTX)) | |
3236 | record_set (SET_DEST (PATTERN (insn)), NULL_RTX, NULL); | |
3237 | else | |
3238 | note_stores (PATTERN (insn), record_set, NULL); | |
6e73e666 | 3239 | |
131db6b8 | 3240 | set = single_set (insn); |
6e73e666 | 3241 | |
131db6b8 SB |
3242 | if (set != 0 |
3243 | && REG_P (SET_DEST (set)) | |
3244 | && REGNO (SET_DEST (set)) >= FIRST_PSEUDO_REGISTER) | |
713f41f9 | 3245 | { |
131db6b8 SB |
3246 | unsigned int regno = REGNO (SET_DEST (set)); |
3247 | rtx src = SET_SRC (set); | |
3248 | rtx t; | |
3249 | ||
3250 | note = find_reg_equal_equiv_note (insn); | |
3251 | if (note && REG_NOTE_KIND (note) == REG_EQUAL | |
3252 | && DF_REG_DEF_COUNT (regno) != 1) | |
3253 | note = NULL_RTX; | |
3254 | ||
3255 | if (note != NULL_RTX | |
3256 | && GET_CODE (XEXP (note, 0)) != EXPR_LIST | |
3257 | && ! rtx_varies_p (XEXP (note, 0), 1) | |
3258 | && ! reg_overlap_mentioned_p (SET_DEST (set), | |
3259 | XEXP (note, 0))) | |
3260 | { | |
3261 | set_reg_known_value (regno, XEXP (note, 0)); | |
3262 | set_reg_known_equiv_p (regno, | |
3263 | REG_NOTE_KIND (note) == REG_EQUIV); | |
3264 | } | |
3265 | else if (DF_REG_DEF_COUNT (regno) == 1 | |
3266 | && GET_CODE (src) == PLUS | |
3267 | && REG_P (XEXP (src, 0)) | |
3268 | && (t = get_reg_known_value (REGNO (XEXP (src, 0)))) | |
3269 | && CONST_INT_P (XEXP (src, 1))) | |
3270 | { | |
3271 | t = plus_constant (GET_MODE (src), t, | |
3272 | INTVAL (XEXP (src, 1))); | |
3273 | set_reg_known_value (regno, t); | |
3274 | set_reg_known_equiv_p (regno, false); | |
3275 | } | |
3276 | else if (DF_REG_DEF_COUNT (regno) == 1 | |
3277 | && ! rtx_varies_p (src, 1)) | |
3278 | { | |
3279 | set_reg_known_value (regno, src); | |
3280 | set_reg_known_equiv_p (regno, false); | |
3281 | } | |
713f41f9 | 3282 | } |
6e73e666 | 3283 | } |
131db6b8 SB |
3284 | else if (NOTE_P (insn) |
3285 | && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG) | |
3286 | copying_arguments = false; | |
ec907dd8 | 3287 | } |
6e73e666 | 3288 | } |
ec907dd8 | 3289 | |
6e73e666 | 3290 | /* Now propagate values from new_reg_base_value to reg_base_value. */ |
62e5bf5d | 3291 | gcc_assert (maxreg == (unsigned int) max_reg_num ()); |
c22cacf3 | 3292 | |
c582d54a | 3293 | for (ui = 0; ui < maxreg; ui++) |
6e73e666 | 3294 | { |
e51712db | 3295 | if (new_reg_base_value[ui] |
9771b263 DN |
3296 | && new_reg_base_value[ui] != (*reg_base_value)[ui] |
3297 | && ! rtx_equal_p (new_reg_base_value[ui], (*reg_base_value)[ui])) | |
ec907dd8 | 3298 | { |
9771b263 | 3299 | (*reg_base_value)[ui] = new_reg_base_value[ui]; |
6e73e666 | 3300 | changed = 1; |
ec907dd8 | 3301 | } |
9ae8ffe7 | 3302 | } |
9ae8ffe7 | 3303 | } |
6e73e666 | 3304 | while (changed && ++pass < MAX_ALIAS_LOOP_PASSES); |
131db6b8 | 3305 | XDELETEVEC (rpo); |
9ae8ffe7 JL |
3306 | |
3307 | /* Fill in the remaining entries. */ | |
9771b263 | 3308 | FOR_EACH_VEC_ELT (*reg_known_value, i, val) |
9ff3c7ca SB |
3309 | { |
3310 | int regno = i + FIRST_PSEUDO_REGISTER; | |
3311 | if (! val) | |
3312 | set_reg_known_value (regno, regno_reg_rtx[regno]); | |
3313 | } | |
9ae8ffe7 | 3314 | |
e05e2395 MM |
3315 | /* Clean up. */ |
3316 | free (new_reg_base_value); | |
ec907dd8 | 3317 | new_reg_base_value = 0; |
d630245f | 3318 | sbitmap_free (reg_seen); |
9ae8ffe7 | 3319 | reg_seen = 0; |
0d446150 | 3320 | timevar_pop (TV_ALIAS_ANALYSIS); |
9ae8ffe7 JL |
3321 | } |
3322 | ||
61630b27 JJ |
3323 | /* Equate REG_BASE_VALUE (reg1) to REG_BASE_VALUE (reg2). |
3324 | Special API for var-tracking pass purposes. */ | |
3325 | ||
3326 | void | |
3327 | vt_equate_reg_base_value (const_rtx reg1, const_rtx reg2) | |
3328 | { | |
9771b263 | 3329 | (*reg_base_value)[REGNO (reg1)] = REG_BASE_VALUE (reg2); |
61630b27 JJ |
3330 | } |
3331 | ||
9ae8ffe7 | 3332 | void |
4682ae04 | 3333 | end_alias_analysis (void) |
9ae8ffe7 | 3334 | { |
c582d54a | 3335 | old_reg_base_value = reg_base_value; |
9771b263 | 3336 | vec_free (reg_known_value); |
9ff3c7ca | 3337 | sbitmap_free (reg_known_equiv_p); |
9ae8ffe7 | 3338 | } |
e2500fed | 3339 | |
3ecf9d13 JH |
3340 | void |
3341 | dump_alias_stats_in_alias_c (FILE *s) | |
3342 | { | |
3343 | fprintf (s, " TBAA oracle: %llu disambiguations %llu queries\n" | |
3344 | " %llu are in alias set 0\n" | |
3345 | " %llu queries asked about the same object\n" | |
3346 | " %llu queries asked about the same alias set\n" | |
3347 | " %llu access volatile\n" | |
6e042ef4 JH |
3348 | " %llu are dependent in the DAG\n" |
3349 | " %llu are aritificially in conflict with void *\n", | |
3ecf9d13 JH |
3350 | alias_stats.num_disambiguated, |
3351 | alias_stats.num_alias_zero + alias_stats.num_same_alias_set | |
3352 | + alias_stats.num_same_objects + alias_stats.num_volatile | |
6e042ef4 JH |
3353 | + alias_stats.num_dag + alias_stats.num_disambiguated |
3354 | + alias_stats.num_universal, | |
3ecf9d13 | 3355 | alias_stats.num_alias_zero, alias_stats.num_same_alias_set, |
6e042ef4 JH |
3356 | alias_stats.num_same_objects, alias_stats.num_volatile, |
3357 | alias_stats.num_dag, alias_stats.num_universal); | |
3ecf9d13 | 3358 | } |
e2500fed | 3359 | #include "gt-alias.h" |