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9ae8ffe7 | 1 | /* Alias analysis for GNU C |
85ec4feb | 2 | Copyright (C) 1997-2018 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" |
4d0cdd0c | 30 | #include "memmodel.h" |
957060b5 AM |
31 | #include "tm_p.h" |
32 | #include "gimple-ssa.h" | |
957060b5 | 33 | #include "emit-rtl.h" |
40e23961 | 34 | #include "alias.h" |
40e23961 | 35 | #include "fold-const.h" |
d8a2d370 | 36 | #include "varasm.h" |
eab5c70a | 37 | #include "cselib.h" |
d23c55c2 | 38 | #include "langhooks.h" |
60393bbc | 39 | #include "cfganal.h" |
403837b4 | 40 | #include "rtl-iter.h" |
54363f8a | 41 | #include "cgraph.h" |
ea900239 DB |
42 | |
43 | /* The aliasing API provided here solves related but different problems: | |
44 | ||
c22cacf3 | 45 | Say there exists (in c) |
ea900239 DB |
46 | |
47 | struct X { | |
48 | struct Y y1; | |
49 | struct Z z2; | |
50 | } x1, *px1, *px2; | |
51 | ||
52 | struct Y y2, *py; | |
53 | struct Z z2, *pz; | |
54 | ||
55 | ||
308a3fe2 | 56 | py = &x1.y1; |
ea900239 DB |
57 | px2 = &x1; |
58 | ||
59 | Consider the four questions: | |
60 | ||
61 | Can a store to x1 interfere with px2->y1? | |
62 | Can a store to x1 interfere with px2->z2? | |
ea900239 DB |
63 | Can a store to x1 change the value pointed to by with py? |
64 | Can a store to x1 change the value pointed to by with pz? | |
65 | ||
66 | The answer to these questions can be yes, yes, yes, and maybe. | |
67 | ||
68 | The first two questions can be answered with a simple examination | |
69 | of the type system. If structure X contains a field of type Y then | |
073a8998 | 70 | a store through a pointer to an X can overwrite any field that is |
ea900239 DB |
71 | contained (recursively) in an X (unless we know that px1 != px2). |
72 | ||
308a3fe2 DS |
73 | The last two questions can be solved in the same way as the first |
74 | two questions but this is too conservative. The observation is | |
75 | that in some cases we can know which (if any) fields are addressed | |
76 | and if those addresses are used in bad ways. This analysis may be | |
77 | language specific. In C, arbitrary operations may be applied to | |
78 | pointers. However, there is some indication that this may be too | |
79 | conservative for some C++ types. | |
ea900239 DB |
80 | |
81 | The pass ipa-type-escape does this analysis for the types whose | |
c22cacf3 | 82 | instances do not escape across the compilation boundary. |
ea900239 DB |
83 | |
84 | Historically in GCC, these two problems were combined and a single | |
308a3fe2 | 85 | data structure that was used to represent the solution to these |
ea900239 | 86 | problems. We now have two similar but different data structures, |
308a3fe2 DS |
87 | The data structure to solve the last two questions is similar to |
88 | the first, but does not contain the fields whose address are never | |
89 | taken. For types that do escape the compilation unit, the data | |
90 | structures will have identical information. | |
ea900239 | 91 | */ |
3932261a MM |
92 | |
93 | /* The alias sets assigned to MEMs assist the back-end in determining | |
94 | which MEMs can alias which other MEMs. In general, two MEMs in | |
ac3d9668 RK |
95 | different alias sets cannot alias each other, with one important |
96 | exception. Consider something like: | |
3932261a | 97 | |
01d28c3f | 98 | struct S { int i; double d; }; |
3932261a MM |
99 | |
100 | a store to an `S' can alias something of either type `int' or type | |
101 | `double'. (However, a store to an `int' cannot alias a `double' | |
102 | and vice versa.) We indicate this via a tree structure that looks | |
103 | like: | |
c22cacf3 MS |
104 | struct S |
105 | / \ | |
3932261a | 106 | / \ |
c22cacf3 MS |
107 | |/_ _\| |
108 | int double | |
3932261a | 109 | |
ac3d9668 RK |
110 | (The arrows are directed and point downwards.) |
111 | In this situation we say the alias set for `struct S' is the | |
112 | `superset' and that those for `int' and `double' are `subsets'. | |
113 | ||
3bdf5ad1 RK |
114 | To see whether two alias sets can point to the same memory, we must |
115 | see if either alias set is a subset of the other. We need not trace | |
95bd1dd7 | 116 | past immediate descendants, however, since we propagate all |
3bdf5ad1 | 117 | grandchildren up one level. |
3932261a MM |
118 | |
119 | Alias set zero is implicitly a superset of all other alias sets. | |
120 | However, this is no actual entry for alias set zero. It is an | |
121 | error to attempt to explicitly construct a subset of zero. */ | |
122 | ||
e0702244 | 123 | struct alias_set_hash : int_hash <int, INT_MIN, INT_MIN + 1> {}; |
de144fb2 | 124 | |
02ced957 | 125 | struct GTY(()) alias_set_entry { |
3932261a | 126 | /* The alias set number, as stored in MEM_ALIAS_SET. */ |
4862826d | 127 | alias_set_type alias_set; |
3932261a | 128 | |
6e042ef4 JH |
129 | /* Nonzero if would have a child of zero: this effectively makes this |
130 | alias set the same as alias set zero. */ | |
131 | bool has_zero_child; | |
132 | /* Nonzero if alias set corresponds to pointer type itself (i.e. not to | |
133 | aggregate contaiing pointer. | |
134 | This is used for a special case where we need an universal pointer type | |
135 | compatible with all other pointer types. */ | |
136 | bool is_pointer; | |
137 | /* Nonzero if is_pointer or if one of childs have has_pointer set. */ | |
138 | bool has_pointer; | |
34e82342 RB |
139 | |
140 | /* The children of the alias set. These are not just the immediate | |
141 | children, but, in fact, all descendants. So, if we have: | |
142 | ||
143 | struct T { struct S s; float f; } | |
144 | ||
145 | continuing our example above, the children here will be all of | |
146 | `int', `double', `float', and `struct S'. */ | |
147 | hash_map<alias_set_hash, int> *children; | |
b604074c | 148 | }; |
9ae8ffe7 | 149 | |
ed7a4b4b | 150 | static int rtx_equal_for_memref_p (const_rtx, const_rtx); |
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); |
73e48cb3 | 161 | static int compare_base_symbol_refs (const_rtx, const_rtx); |
4682ae04 | 162 | |
aa317c97 | 163 | static void memory_modified_1 (rtx, const_rtx, void *); |
9ae8ffe7 | 164 | |
3ecf9d13 JH |
165 | /* Query statistics for the different low-level disambiguators. |
166 | A high-level query may trigger multiple of them. */ | |
167 | ||
168 | static struct { | |
169 | unsigned long long num_alias_zero; | |
170 | unsigned long long num_same_alias_set; | |
171 | unsigned long long num_same_objects; | |
172 | unsigned long long num_volatile; | |
173 | unsigned long long num_dag; | |
6e042ef4 | 174 | unsigned long long num_universal; |
3ecf9d13 JH |
175 | unsigned long long num_disambiguated; |
176 | } alias_stats; | |
177 | ||
178 | ||
9ae8ffe7 JL |
179 | /* Set up all info needed to perform alias analysis on memory references. */ |
180 | ||
d4b60170 | 181 | /* Returns the size in bytes of the mode of X. */ |
9ae8ffe7 JL |
182 | #define SIZE_FOR_MODE(X) (GET_MODE_SIZE (GET_MODE (X))) |
183 | ||
ea64ef27 | 184 | /* Cap the number of passes we make over the insns propagating alias |
131db6b8 SB |
185 | information through set chains. |
186 | ??? 10 is a completely arbitrary choice. This should be based on the | |
187 | maximum loop depth in the CFG, but we do not have this information | |
188 | available (even if current_loops _is_ available). */ | |
ea64ef27 | 189 | #define MAX_ALIAS_LOOP_PASSES 10 |
ca7fd9cd | 190 | |
9ae8ffe7 JL |
191 | /* reg_base_value[N] gives an address to which register N is related. |
192 | If all sets after the first add or subtract to the current value | |
193 | or otherwise modify it so it does not point to a different top level | |
194 | object, reg_base_value[N] is equal to the address part of the source | |
2a2c8203 JC |
195 | of the first set. |
196 | ||
197 | A base address can be an ADDRESS, SYMBOL_REF, or LABEL_REF. ADDRESS | |
9fc37b2b | 198 | expressions represent three types of base: |
b3b5ad95 | 199 | |
9fc37b2b RS |
200 | 1. incoming arguments. There is just one ADDRESS to represent all |
201 | arguments, since we do not know at this level whether accesses | |
202 | based on different arguments can alias. The ADDRESS has id 0. | |
b3b5ad95 | 203 | |
9fc37b2b RS |
204 | 2. stack_pointer_rtx, frame_pointer_rtx, hard_frame_pointer_rtx |
205 | (if distinct from frame_pointer_rtx) and arg_pointer_rtx. | |
206 | Each of these rtxes has a separate ADDRESS associated with it, | |
207 | each with a negative id. | |
208 | ||
209 | GCC is (and is required to be) precise in which register it | |
210 | chooses to access a particular region of stack. We can therefore | |
211 | assume that accesses based on one of these rtxes do not alias | |
212 | accesses based on another of these rtxes. | |
213 | ||
214 | 3. bases that are derived from malloc()ed memory (REG_NOALIAS). | |
215 | Each such piece of memory has a separate ADDRESS associated | |
216 | with it, each with an id greater than 0. | |
217 | ||
218 | Accesses based on one ADDRESS do not alias accesses based on other | |
219 | ADDRESSes. Accesses based on ADDRESSes in groups (2) and (3) do not | |
220 | alias globals either; the ADDRESSes have Pmode to indicate this. | |
221 | The ADDRESS in group (1) _may_ alias globals; it has VOIDmode to | |
222 | indicate this. */ | |
2a2c8203 | 223 | |
9771b263 | 224 | static GTY(()) vec<rtx, va_gc> *reg_base_value; |
ac606739 | 225 | static rtx *new_reg_base_value; |
c582d54a | 226 | |
9fc37b2b RS |
227 | /* The single VOIDmode ADDRESS that represents all argument bases. |
228 | It has id 0. */ | |
229 | static GTY(()) rtx arg_base_value; | |
230 | ||
231 | /* Used to allocate unique ids to each REG_NOALIAS ADDRESS. */ | |
232 | static int unique_id; | |
233 | ||
c582d54a JH |
234 | /* We preserve the copy of old array around to avoid amount of garbage |
235 | produced. About 8% of garbage produced were attributed to this | |
236 | array. */ | |
9771b263 | 237 | static GTY((deletable)) vec<rtx, va_gc> *old_reg_base_value; |
d4b60170 | 238 | |
9e412ca3 RS |
239 | /* Values of XINT (address, 0) of Pmode ADDRESS rtxes for special |
240 | registers. */ | |
241 | #define UNIQUE_BASE_VALUE_SP -1 | |
242 | #define UNIQUE_BASE_VALUE_ARGP -2 | |
243 | #define UNIQUE_BASE_VALUE_FP -3 | |
244 | #define UNIQUE_BASE_VALUE_HFP -4 | |
245 | ||
7bf84454 RS |
246 | #define static_reg_base_value \ |
247 | (this_target_rtl->x_static_reg_base_value) | |
bf1660a6 | 248 | |
9771b263 DN |
249 | #define REG_BASE_VALUE(X) \ |
250 | (REGNO (X) < vec_safe_length (reg_base_value) \ | |
251 | ? (*reg_base_value)[REGNO (X)] : 0) | |
9ae8ffe7 | 252 | |
c13e8210 | 253 | /* Vector indexed by N giving the initial (unchanging) value known for |
9ff3c7ca | 254 | pseudo-register N. This vector is initialized in init_alias_analysis, |
bb1acb3e | 255 | and does not change until end_alias_analysis is called. */ |
9771b263 | 256 | static GTY(()) vec<rtx, va_gc> *reg_known_value; |
9ae8ffe7 JL |
257 | |
258 | /* Vector recording for each reg_known_value whether it is due to a | |
259 | REG_EQUIV note. Future passes (viz., reload) may replace the | |
260 | pseudo with the equivalent expression and so we account for the | |
ac3d9668 RK |
261 | dependences that would be introduced if that happens. |
262 | ||
263 | The REG_EQUIV notes created in assign_parms may mention the arg | |
264 | pointer, and there are explicit insns in the RTL that modify the | |
265 | arg pointer. Thus we must ensure that such insns don't get | |
266 | scheduled across each other because that would invalidate the | |
267 | REG_EQUIV notes. One could argue that the REG_EQUIV notes are | |
268 | wrong, but solving the problem in the scheduler will likely give | |
269 | better code, so we do it here. */ | |
9ff3c7ca | 270 | static sbitmap reg_known_equiv_p; |
9ae8ffe7 | 271 | |
2a2c8203 JC |
272 | /* True when scanning insns from the start of the rtl to the |
273 | NOTE_INSN_FUNCTION_BEG note. */ | |
83bbd9b6 | 274 | static bool copying_arguments; |
9ae8ffe7 | 275 | |
1a5640b4 | 276 | |
3932261a | 277 | /* The splay-tree used to store the various alias set entries. */ |
02ced957 | 278 | static GTY (()) vec<alias_set_entry *, va_gc> *alias_sets; |
ac3d9668 | 279 | \f |
55b34b5f RG |
280 | /* Build a decomposed reference object for querying the alias-oracle |
281 | from the MEM rtx and store it in *REF. | |
282 | Returns false if MEM is not suitable for the alias-oracle. */ | |
283 | ||
284 | static bool | |
285 | ao_ref_from_mem (ao_ref *ref, const_rtx mem) | |
286 | { | |
287 | tree expr = MEM_EXPR (mem); | |
288 | tree base; | |
289 | ||
290 | if (!expr) | |
291 | return false; | |
292 | ||
293 | ao_ref_init (ref, expr); | |
294 | ||
295 | /* Get the base of the reference and see if we have to reject or | |
296 | adjust it. */ | |
297 | base = ao_ref_base (ref); | |
298 | if (base == NULL_TREE) | |
299 | return false; | |
300 | ||
ef7a9fb8 RB |
301 | /* The tree oracle doesn't like bases that are neither decls |
302 | nor indirect references of SSA names. */ | |
303 | if (!(DECL_P (base) | |
304 | || (TREE_CODE (base) == MEM_REF | |
305 | && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME) | |
306 | || (TREE_CODE (base) == TARGET_MEM_REF | |
307 | && TREE_CODE (TMR_BASE (base)) == SSA_NAME))) | |
d15adbeb | 308 | return false; |
55b34b5f RG |
309 | |
310 | /* If this is a reference based on a partitioned decl replace the | |
ef7a9fb8 | 311 | base with a MEM_REF of the pointer representative we |
55b34b5f | 312 | created during stack slot partitioning. */ |
8813a647 | 313 | if (VAR_P (base) |
ef7a9fb8 | 314 | && ! is_global_var (base) |
55b34b5f RG |
315 | && cfun->gimple_df->decls_to_pointers != NULL) |
316 | { | |
39c8aaa4 | 317 | tree *namep = cfun->gimple_df->decls_to_pointers->get (base); |
55b34b5f | 318 | if (namep) |
39c8aaa4 | 319 | ref->base = build_simple_mem_ref (*namep); |
d15adbeb | 320 | } |
55b34b5f RG |
321 | |
322 | ref->ref_alias_set = MEM_ALIAS_SET (mem); | |
323 | ||
f68396a1 RG |
324 | /* If MEM_OFFSET or MEM_SIZE are unknown what we got from MEM_EXPR |
325 | is conservative, so trust it. */ | |
527210c4 | 326 | if (!MEM_OFFSET_KNOWN_P (mem) |
f5541398 | 327 | || !MEM_SIZE_KNOWN_P (mem)) |
f68396a1 | 328 | return true; |
366f945f | 329 | |
e8024441 RB |
330 | /* If MEM_OFFSET/MEM_SIZE get us outside of ref->offset/ref->max_size |
331 | drop ref->ref. */ | |
d05d7551 | 332 | if (maybe_lt (MEM_OFFSET (mem), 0) |
b9c25734 RS |
333 | || (ref->max_size_known_p () |
334 | && maybe_gt ((MEM_OFFSET (mem) + MEM_SIZE (mem)) * BITS_PER_UNIT, | |
335 | ref->max_size))) | |
e8024441 | 336 | ref->ref = NULL_TREE; |
b0e96404 | 337 | |
e8024441 RB |
338 | /* Refine size and offset we got from analyzing MEM_EXPR by using |
339 | MEM_SIZE and MEM_OFFSET. */ | |
f68396a1 | 340 | |
527210c4 | 341 | ref->offset += MEM_OFFSET (mem) * BITS_PER_UNIT; |
f5541398 | 342 | ref->size = MEM_SIZE (mem) * BITS_PER_UNIT; |
b0e96404 RG |
343 | |
344 | /* The MEM may extend into adjacent fields, so adjust max_size if | |
345 | necessary. */ | |
b9c25734 RS |
346 | if (ref->max_size_known_p ()) |
347 | ref->max_size = upper_bound (ref->max_size, ref->size); | |
b0e96404 | 348 | |
b9c25734 | 349 | /* If MEM_OFFSET and MEM_SIZE might get us outside of the base object of |
b0e96404 RG |
350 | the MEM_EXPR punt. This happens for STRICT_ALIGNMENT targets a lot. */ |
351 | if (MEM_EXPR (mem) != get_spill_slot_decl (false) | |
b9c25734 | 352 | && (maybe_lt (ref->offset, 0) |
b0e96404 | 353 | || (DECL_P (ref->base) |
807e902e | 354 | && (DECL_SIZE (ref->base) == NULL_TREE |
b9c25734 RS |
355 | || !poly_int_tree_p (DECL_SIZE (ref->base)) |
356 | || maybe_lt (wi::to_poly_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 | |
350792ff RB |
614 | if (AGGREGATE_TYPE_P (TREE_TYPE (t)) |
615 | && TYPE_TYPELESS_STORAGE (TREE_TYPE (t))) | |
616 | return const_cast <tree> (t); | |
617 | ||
b4ada065 RB |
618 | while (handled_component_p (t)) |
619 | { | |
afe84921 RH |
620 | switch (TREE_CODE (t)) |
621 | { | |
622 | case COMPONENT_REF: | |
623 | if (DECL_NONADDRESSABLE_P (TREE_OPERAND (t, 1))) | |
b4ada065 | 624 | found = t; |
4aa83879 RB |
625 | /* Permit type-punning when accessing a union, provided the access |
626 | is directly through the union. For example, this code does not | |
627 | permit taking the address of a union member and then storing | |
628 | through it. Even the type-punning allowed here is a GCC | |
629 | extension, albeit a common and useful one; the C standard says | |
630 | that such accesses have implementation-defined behavior. */ | |
631 | else if (TREE_CODE (TREE_TYPE (TREE_OPERAND (t, 0))) == UNION_TYPE) | |
632 | found = t; | |
afe84921 RH |
633 | break; |
634 | ||
635 | case ARRAY_REF: | |
636 | case ARRAY_RANGE_REF: | |
637 | if (TYPE_NONALIASED_COMPONENT (TREE_TYPE (TREE_OPERAND (t, 0)))) | |
b4ada065 | 638 | found = t; |
afe84921 RH |
639 | break; |
640 | ||
641 | case REALPART_EXPR: | |
642 | case IMAGPART_EXPR: | |
643 | break; | |
644 | ||
b4ada065 RB |
645 | case BIT_FIELD_REF: |
646 | case VIEW_CONVERT_EXPR: | |
afe84921 | 647 | /* Bitfields and casts are never addressable. */ |
b4ada065 RB |
648 | found = t; |
649 | break; | |
650 | ||
651 | default: | |
652 | gcc_unreachable (); | |
afe84921 RH |
653 | } |
654 | ||
b4ada065 RB |
655 | if (get_alias_set (TREE_TYPE (TREE_OPERAND (t, 0))) == 0) |
656 | found = t; | |
657 | ||
afe84921 RH |
658 | t = TREE_OPERAND (t, 0); |
659 | } | |
b4ada065 RB |
660 | |
661 | if (found) | |
662 | return TREE_OPERAND (found, 0); | |
663 | ||
664 | return NULL_TREE; | |
6e24b709 RK |
665 | } |
666 | ||
f40333af RB |
667 | |
668 | /* Return whether the pointer-type T effective for aliasing may | |
669 | access everything and thus the reference has to be assigned | |
670 | alias-set zero. */ | |
671 | ||
672 | static bool | |
673 | ref_all_alias_ptr_type_p (const_tree t) | |
674 | { | |
675 | return (TREE_CODE (TREE_TYPE (t)) == VOID_TYPE | |
676 | || TYPE_REF_CAN_ALIAS_ALL (t)); | |
677 | } | |
678 | ||
5006671f RG |
679 | /* Return the alias set for the memory pointed to by T, which may be |
680 | either a type or an expression. Return -1 if there is nothing | |
681 | special about dereferencing T. */ | |
682 | ||
683 | static alias_set_type | |
684 | get_deref_alias_set_1 (tree t) | |
685 | { | |
5b21f0f3 | 686 | /* All we care about is the type. */ |
5006671f | 687 | if (! TYPE_P (t)) |
5b21f0f3 | 688 | t = TREE_TYPE (t); |
5006671f RG |
689 | |
690 | /* If we have an INDIRECT_REF via a void pointer, we don't | |
691 | know anything about what that might alias. Likewise if the | |
692 | pointer is marked that way. */ | |
f40333af | 693 | if (ref_all_alias_ptr_type_p (t)) |
5006671f RG |
694 | return 0; |
695 | ||
696 | return -1; | |
697 | } | |
698 | ||
699 | /* Return the alias set for the memory pointed to by T, which may be | |
700 | either a type or an expression. */ | |
701 | ||
702 | alias_set_type | |
703 | get_deref_alias_set (tree t) | |
704 | { | |
f40333af RB |
705 | /* If we're not doing any alias analysis, just assume everything |
706 | aliases everything else. */ | |
707 | if (!flag_strict_aliasing) | |
708 | return 0; | |
709 | ||
5006671f RG |
710 | alias_set_type set = get_deref_alias_set_1 (t); |
711 | ||
712 | /* Fall back to the alias-set of the pointed-to type. */ | |
713 | if (set == -1) | |
714 | { | |
715 | if (! TYPE_P (t)) | |
716 | t = TREE_TYPE (t); | |
717 | set = get_alias_set (TREE_TYPE (t)); | |
718 | } | |
719 | ||
720 | return set; | |
721 | } | |
722 | ||
f40333af RB |
723 | /* Return the pointer-type relevant for TBAA purposes from the |
724 | memory reference tree *T or NULL_TREE in which case *T is | |
725 | adjusted to point to the outermost component reference that | |
726 | can be used for assigning an alias set. */ | |
727 | ||
728 | static tree | |
729 | reference_alias_ptr_type_1 (tree *t) | |
730 | { | |
731 | tree inner; | |
732 | ||
733 | /* Get the base object of the reference. */ | |
734 | inner = *t; | |
735 | while (handled_component_p (inner)) | |
736 | { | |
737 | /* If there is a VIEW_CONVERT_EXPR in the chain we cannot use | |
738 | the type of any component references that wrap it to | |
739 | determine the alias-set. */ | |
740 | if (TREE_CODE (inner) == VIEW_CONVERT_EXPR) | |
741 | *t = TREE_OPERAND (inner, 0); | |
742 | inner = TREE_OPERAND (inner, 0); | |
743 | } | |
744 | ||
745 | /* Handle pointer dereferences here, they can override the | |
746 | alias-set. */ | |
747 | if (INDIRECT_REF_P (inner) | |
748 | && ref_all_alias_ptr_type_p (TREE_TYPE (TREE_OPERAND (inner, 0)))) | |
749 | return TREE_TYPE (TREE_OPERAND (inner, 0)); | |
750 | else if (TREE_CODE (inner) == TARGET_MEM_REF) | |
751 | return TREE_TYPE (TMR_OFFSET (inner)); | |
752 | else if (TREE_CODE (inner) == MEM_REF | |
753 | && ref_all_alias_ptr_type_p (TREE_TYPE (TREE_OPERAND (inner, 1)))) | |
754 | return TREE_TYPE (TREE_OPERAND (inner, 1)); | |
755 | ||
756 | /* If the innermost reference is a MEM_REF that has a | |
757 | conversion embedded treat it like a VIEW_CONVERT_EXPR above, | |
758 | using the memory access type for determining the alias-set. */ | |
759 | if (TREE_CODE (inner) == MEM_REF | |
760 | && (TYPE_MAIN_VARIANT (TREE_TYPE (inner)) | |
761 | != TYPE_MAIN_VARIANT | |
762 | (TREE_TYPE (TREE_TYPE (TREE_OPERAND (inner, 1)))))) | |
763 | return TREE_TYPE (TREE_OPERAND (inner, 1)); | |
764 | ||
b4ada065 RB |
765 | /* Otherwise, pick up the outermost object that we could have |
766 | a pointer to. */ | |
767 | tree tem = component_uses_parent_alias_set_from (*t); | |
768 | if (tem) | |
769 | *t = tem; | |
f40333af RB |
770 | |
771 | return NULL_TREE; | |
772 | } | |
773 | ||
774 | /* Return the pointer-type relevant for TBAA purposes from the | |
775 | gimple memory reference tree T. This is the type to be used for | |
776 | the offset operand of MEM_REF or TARGET_MEM_REF replacements of T | |
777 | and guarantees that get_alias_set will return the same alias | |
778 | set for T and the replacement. */ | |
779 | ||
780 | tree | |
781 | reference_alias_ptr_type (tree t) | |
782 | { | |
ebc1b29e RB |
783 | /* If the frontend assigns this alias-set zero, preserve that. */ |
784 | if (lang_hooks.get_alias_set (t) == 0) | |
785 | return ptr_type_node; | |
786 | ||
f40333af RB |
787 | tree ptype = reference_alias_ptr_type_1 (&t); |
788 | /* If there is a given pointer type for aliasing purposes, return it. */ | |
789 | if (ptype != NULL_TREE) | |
790 | return ptype; | |
791 | ||
792 | /* Otherwise build one from the outermost component reference we | |
793 | may use. */ | |
794 | if (TREE_CODE (t) == MEM_REF | |
795 | || TREE_CODE (t) == TARGET_MEM_REF) | |
796 | return TREE_TYPE (TREE_OPERAND (t, 1)); | |
797 | else | |
798 | return build_pointer_type (TYPE_MAIN_VARIANT (TREE_TYPE (t))); | |
799 | } | |
800 | ||
801 | /* Return whether the pointer-types T1 and T2 used to determine | |
802 | two alias sets of two references will yield the same answer | |
803 | from get_deref_alias_set. */ | |
804 | ||
805 | bool | |
806 | alias_ptr_types_compatible_p (tree t1, tree t2) | |
807 | { | |
808 | if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2)) | |
809 | return true; | |
810 | ||
811 | if (ref_all_alias_ptr_type_p (t1) | |
812 | || ref_all_alias_ptr_type_p (t2)) | |
813 | return false; | |
814 | ||
815 | return (TYPE_MAIN_VARIANT (TREE_TYPE (t1)) | |
816 | == TYPE_MAIN_VARIANT (TREE_TYPE (t2))); | |
817 | } | |
818 | ||
6e042ef4 JH |
819 | /* Create emptry alias set entry. */ |
820 | ||
02ced957 | 821 | alias_set_entry * |
6e042ef4 JH |
822 | init_alias_set_entry (alias_set_type set) |
823 | { | |
02ced957 | 824 | alias_set_entry *ase = ggc_alloc<alias_set_entry> (); |
6e042ef4 JH |
825 | ase->alias_set = set; |
826 | ase->children = NULL; | |
827 | ase->has_zero_child = false; | |
828 | ase->is_pointer = false; | |
829 | ase->has_pointer = false; | |
830 | gcc_checking_assert (!get_alias_set_entry (set)); | |
831 | (*alias_sets)[set] = ase; | |
832 | return ase; | |
833 | } | |
834 | ||
3bdf5ad1 RK |
835 | /* Return the alias set for T, which may be either a type or an |
836 | expression. Call language-specific routine for help, if needed. */ | |
837 | ||
4862826d | 838 | alias_set_type |
4682ae04 | 839 | get_alias_set (tree t) |
3bdf5ad1 | 840 | { |
4862826d | 841 | alias_set_type set; |
3bdf5ad1 | 842 | |
bd04cddf JH |
843 | /* We can not give up with -fno-strict-aliasing because we need to build |
844 | proper type representation for possible functions which are build with | |
e8444ca6 | 845 | -fstrict-aliasing. */ |
bd04cddf JH |
846 | |
847 | /* return 0 if this or its type is an error. */ | |
848 | if (t == error_mark_node | |
3bdf5ad1 RK |
849 | || (! TYPE_P (t) |
850 | && (TREE_TYPE (t) == 0 || TREE_TYPE (t) == error_mark_node))) | |
851 | return 0; | |
852 | ||
853 | /* We can be passed either an expression or a type. This and the | |
f47e9b4e RK |
854 | language-specific routine may make mutually-recursive calls to each other |
855 | to figure out what to do. At each juncture, we see if this is a tree | |
856 | that the language may need to handle specially. First handle things that | |
738cc472 | 857 | aren't types. */ |
f824e5c3 | 858 | if (! TYPE_P (t)) |
3bdf5ad1 | 859 | { |
70f34814 RG |
860 | /* Give the language a chance to do something with this tree |
861 | before we look at it. */ | |
8ac61af7 | 862 | STRIP_NOPS (t); |
ae2bcd98 | 863 | set = lang_hooks.get_alias_set (t); |
8ac61af7 RK |
864 | if (set != -1) |
865 | return set; | |
866 | ||
f40333af RB |
867 | /* Get the alias pointer-type to use or the outermost object |
868 | that we could have a pointer to. */ | |
869 | tree ptype = reference_alias_ptr_type_1 (&t); | |
870 | if (ptype != NULL) | |
871 | return get_deref_alias_set (ptype); | |
f824e5c3 | 872 | |
738cc472 RK |
873 | /* If we've already determined the alias set for a decl, just return |
874 | it. This is necessary for C++ anonymous unions, whose component | |
875 | variables don't look like union members (boo!). */ | |
8813a647 | 876 | if (VAR_P (t) |
3c0cb5de | 877 | && DECL_RTL_SET_P (t) && MEM_P (DECL_RTL (t))) |
5755cd38 JM |
878 | return MEM_ALIAS_SET (DECL_RTL (t)); |
879 | ||
f824e5c3 RK |
880 | /* Now all we care about is the type. */ |
881 | t = TREE_TYPE (t); | |
3bdf5ad1 RK |
882 | } |
883 | ||
3bdf5ad1 | 884 | /* Variant qualifiers don't affect the alias set, so get the main |
daad0278 | 885 | variant. */ |
3bdf5ad1 | 886 | t = TYPE_MAIN_VARIANT (t); |
daad0278 | 887 | |
350792ff RB |
888 | if (AGGREGATE_TYPE_P (t) |
889 | && TYPE_TYPELESS_STORAGE (t)) | |
890 | return 0; | |
891 | ||
daad0278 RG |
892 | /* Always use the canonical type as well. If this is a type that |
893 | requires structural comparisons to identify compatible types | |
894 | use alias set zero. */ | |
895 | if (TYPE_STRUCTURAL_EQUALITY_P (t)) | |
cb9c2485 JM |
896 | { |
897 | /* Allow the language to specify another alias set for this | |
898 | type. */ | |
899 | set = lang_hooks.get_alias_set (t); | |
900 | if (set != -1) | |
901 | return set; | |
aea50b45 JH |
902 | /* Handle structure type equality for pointer types, arrays and vectors. |
903 | This is easy to do, because the code bellow ignore canonical types on | |
904 | these anyway. This is important for LTO, where TYPE_CANONICAL for | |
905 | pointers can not be meaningfuly computed by the frotnend. */ | |
906 | if (canonical_type_used_p (t)) | |
f85d2487 JH |
907 | { |
908 | /* In LTO we set canonical types for all types where it makes | |
909 | sense to do so. Double check we did not miss some type. */ | |
910 | gcc_checking_assert (!in_lto_p || !type_with_alias_set_p (t)); | |
911 | return 0; | |
912 | } | |
913 | } | |
914 | else | |
915 | { | |
916 | t = TYPE_CANONICAL (t); | |
917 | gcc_checking_assert (!TYPE_STRUCTURAL_EQUALITY_P (t)); | |
cb9c2485 | 918 | } |
daad0278 RG |
919 | |
920 | /* If this is a type with a known alias set, return it. */ | |
ba6a6a1d | 921 | gcc_checking_assert (t == TYPE_MAIN_VARIANT (t)); |
738cc472 | 922 | if (TYPE_ALIAS_SET_KNOWN_P (t)) |
3bdf5ad1 RK |
923 | return TYPE_ALIAS_SET (t); |
924 | ||
36784d0e RG |
925 | /* We don't want to set TYPE_ALIAS_SET for incomplete types. */ |
926 | if (!COMPLETE_TYPE_P (t)) | |
927 | { | |
928 | /* For arrays with unknown size the conservative answer is the | |
929 | alias set of the element type. */ | |
930 | if (TREE_CODE (t) == ARRAY_TYPE) | |
931 | return get_alias_set (TREE_TYPE (t)); | |
932 | ||
933 | /* But return zero as a conservative answer for incomplete types. */ | |
934 | return 0; | |
935 | } | |
936 | ||
3bdf5ad1 | 937 | /* See if the language has special handling for this type. */ |
ae2bcd98 | 938 | set = lang_hooks.get_alias_set (t); |
8ac61af7 | 939 | if (set != -1) |
738cc472 | 940 | return set; |
2bf105ab | 941 | |
3bdf5ad1 RK |
942 | /* There are no objects of FUNCTION_TYPE, so there's no point in |
943 | using up an alias set for them. (There are, of course, pointers | |
944 | and references to functions, but that's different.) */ | |
7be7d292 | 945 | else if (TREE_CODE (t) == FUNCTION_TYPE || TREE_CODE (t) == METHOD_TYPE) |
3bdf5ad1 | 946 | set = 0; |
74d86f4f RH |
947 | |
948 | /* Unless the language specifies otherwise, let vector types alias | |
949 | their components. This avoids some nasty type punning issues in | |
950 | normal usage. And indeed lets vectors be treated more like an | |
951 | array slice. */ | |
952 | else if (TREE_CODE (t) == VECTOR_TYPE) | |
953 | set = get_alias_set (TREE_TYPE (t)); | |
954 | ||
4653cae5 RG |
955 | /* Unless the language specifies otherwise, treat array types the |
956 | same as their components. This avoids the asymmetry we get | |
957 | through recording the components. Consider accessing a | |
958 | character(kind=1) through a reference to a character(kind=1)[1:1]. | |
959 | Or consider if we want to assign integer(kind=4)[0:D.1387] and | |
960 | integer(kind=4)[4] the same alias set or not. | |
961 | Just be pragmatic here and make sure the array and its element | |
962 | type get the same alias set assigned. */ | |
aea50b45 JH |
963 | else if (TREE_CODE (t) == ARRAY_TYPE |
964 | && (!TYPE_NONALIASED_COMPONENT (t) | |
965 | || TYPE_STRUCTURAL_EQUALITY_P (t))) | |
4653cae5 RG |
966 | set = get_alias_set (TREE_TYPE (t)); |
967 | ||
0ceb0201 RG |
968 | /* From the former common C and C++ langhook implementation: |
969 | ||
970 | Unfortunately, there is no canonical form of a pointer type. | |
971 | In particular, if we have `typedef int I', then `int *', and | |
972 | `I *' are different types. So, we have to pick a canonical | |
973 | representative. We do this below. | |
974 | ||
975 | Technically, this approach is actually more conservative that | |
976 | it needs to be. In particular, `const int *' and `int *' | |
977 | should be in different alias sets, according to the C and C++ | |
978 | standard, since their types are not the same, and so, | |
979 | technically, an `int **' and `const int **' cannot point at | |
980 | the same thing. | |
981 | ||
982 | But, the standard is wrong. In particular, this code is | |
983 | legal C++: | |
984 | ||
985 | int *ip; | |
986 | int **ipp = &ip; | |
987 | const int* const* cipp = ipp; | |
988 | And, it doesn't make sense for that to be legal unless you | |
989 | can dereference IPP and CIPP. So, we ignore cv-qualifiers on | |
990 | the pointed-to types. This issue has been reported to the | |
991 | C++ committee. | |
992 | ||
6e042ef4 JH |
993 | For this reason go to canonical type of the unqalified pointer type. |
994 | Until GCC 6 this code set all pointers sets to have alias set of | |
995 | ptr_type_node but that is a bad idea, because it prevents disabiguations | |
996 | in between pointers. For Firefox this accounts about 20% of all | |
997 | disambiguations in the program. */ | |
f85d2487 | 998 | else if (POINTER_TYPE_P (t) && t != ptr_type_node) |
6e042ef4 JH |
999 | { |
1000 | tree p; | |
1001 | auto_vec <bool, 8> reference; | |
1002 | ||
1003 | /* Unnest all pointers and references. | |
f85d2487 JH |
1004 | We also want to make pointer to array/vector equivalent to pointer to |
1005 | its element (see the reasoning above). Skip all those types, too. */ | |
6e042ef4 | 1006 | for (p = t; POINTER_TYPE_P (p) |
aea50b45 JH |
1007 | || (TREE_CODE (p) == ARRAY_TYPE |
1008 | && (!TYPE_NONALIASED_COMPONENT (p) | |
1009 | || !COMPLETE_TYPE_P (p) | |
1010 | || TYPE_STRUCTURAL_EQUALITY_P (p))) | |
f85d2487 | 1011 | || TREE_CODE (p) == VECTOR_TYPE; |
6e042ef4 JH |
1012 | p = TREE_TYPE (p)) |
1013 | { | |
54363f8a JH |
1014 | /* Ada supports recusive pointers. Instead of doing recrusion check |
1015 | just give up once the preallocated space of 8 elements is up. | |
1016 | In this case just punt to void * alias set. */ | |
1017 | if (reference.length () == 8) | |
1018 | { | |
1019 | p = ptr_type_node; | |
1020 | break; | |
1021 | } | |
6e042ef4 | 1022 | if (TREE_CODE (p) == REFERENCE_TYPE) |
f85d2487 JH |
1023 | /* In LTO we want languages that use references to be compatible |
1024 | with languages that use pointers. */ | |
1025 | reference.safe_push (true && !in_lto_p); | |
6e042ef4 JH |
1026 | if (TREE_CODE (p) == POINTER_TYPE) |
1027 | reference.safe_push (false); | |
1028 | } | |
1029 | p = TYPE_MAIN_VARIANT (p); | |
1030 | ||
1031 | /* Make void * compatible with char * and also void **. | |
1032 | Programs are commonly violating TBAA by this. | |
1033 | ||
1034 | We also make void * to conflict with every pointer | |
1035 | (see record_component_aliases) and thus it is safe it to use it for | |
1036 | pointers to types with TYPE_STRUCTURAL_EQUALITY_P. */ | |
1037 | if (TREE_CODE (p) == VOID_TYPE || TYPE_STRUCTURAL_EQUALITY_P (p)) | |
1038 | set = get_alias_set (ptr_type_node); | |
1039 | else | |
1040 | { | |
f85d2487 | 1041 | /* Rebuild pointer type starting from canonical types using |
6e042ef4 JH |
1042 | unqualified pointers and references only. This way all such |
1043 | pointers will have the same alias set and will conflict with | |
1044 | each other. | |
1045 | ||
1046 | Most of time we already have pointers or references of a given type. | |
1047 | If not we build new one just to be sure that if someone later | |
1048 | (probably only middle-end can, as we should assign all alias | |
1049 | classes only after finishing translation unit) builds the pointer | |
1050 | type, the canonical type will match. */ | |
1051 | p = TYPE_CANONICAL (p); | |
1052 | while (!reference.is_empty ()) | |
1053 | { | |
1054 | if (reference.pop ()) | |
1055 | p = build_reference_type (p); | |
1056 | else | |
1057 | p = build_pointer_type (p); | |
f85d2487 JH |
1058 | gcc_checking_assert (p == TYPE_MAIN_VARIANT (p)); |
1059 | /* build_pointer_type should always return the canonical type. | |
1060 | For LTO TYPE_CANOINCAL may be NULL, because we do not compute | |
1061 | them. Be sure that frontends do not glob canonical types of | |
1062 | pointers in unexpected way and that p == TYPE_CANONICAL (p) | |
1063 | in all other cases. */ | |
1064 | gcc_checking_assert (!TYPE_CANONICAL (p) | |
1065 | || p == TYPE_CANONICAL (p)); | |
6e042ef4 | 1066 | } |
6e042ef4 JH |
1067 | |
1068 | /* Assign the alias set to both p and t. | |
1069 | We can not call get_alias_set (p) here as that would trigger | |
1070 | infinite recursion when p == t. In other cases it would just | |
1071 | trigger unnecesary legwork of rebuilding the pointer again. */ | |
ba6a6a1d | 1072 | gcc_checking_assert (p == TYPE_MAIN_VARIANT (p)); |
6e042ef4 JH |
1073 | if (TYPE_ALIAS_SET_KNOWN_P (p)) |
1074 | set = TYPE_ALIAS_SET (p); | |
1075 | else | |
1076 | { | |
1077 | set = new_alias_set (); | |
1078 | TYPE_ALIAS_SET (p) = set; | |
1079 | } | |
1080 | } | |
1081 | } | |
f85d2487 JH |
1082 | /* Alias set of ptr_type_node is special and serve as universal pointer which |
1083 | is TBAA compatible with every other pointer type. Be sure we have the | |
1084 | alias set built even for LTO which otherwise keeps all TYPE_CANONICAL | |
1085 | of pointer types NULL. */ | |
1086 | else if (t == ptr_type_node) | |
1087 | set = new_alias_set (); | |
0ceb0201 | 1088 | |
7be7d292 | 1089 | /* Otherwise make a new alias set for this type. */ |
3bdf5ad1 | 1090 | else |
96d91dcf RG |
1091 | { |
1092 | /* Each canonical type gets its own alias set, so canonical types | |
1093 | shouldn't form a tree. It doesn't really matter for types | |
1094 | we handle specially above, so only check it where it possibly | |
1095 | would result in a bogus alias set. */ | |
1096 | gcc_checking_assert (TYPE_CANONICAL (t) == t); | |
1097 | ||
1098 | set = new_alias_set (); | |
1099 | } | |
3bdf5ad1 RK |
1100 | |
1101 | TYPE_ALIAS_SET (t) = set; | |
2bf105ab | 1102 | |
7be7d292 EB |
1103 | /* If this is an aggregate type or a complex type, we must record any |
1104 | component aliasing information. */ | |
1d79fd2c | 1105 | if (AGGREGATE_TYPE_P (t) || TREE_CODE (t) == COMPLEX_TYPE) |
2bf105ab RK |
1106 | record_component_aliases (t); |
1107 | ||
6e042ef4 JH |
1108 | /* We treat pointer types specially in alias_set_subset_of. */ |
1109 | if (POINTER_TYPE_P (t) && set) | |
1110 | { | |
02ced957 | 1111 | alias_set_entry *ase = get_alias_set_entry (set); |
6e042ef4 JH |
1112 | if (!ase) |
1113 | ase = init_alias_set_entry (set); | |
1114 | ase->is_pointer = true; | |
1115 | ase->has_pointer = true; | |
1116 | } | |
1117 | ||
3bdf5ad1 RK |
1118 | return set; |
1119 | } | |
1120 | ||
1121 | /* Return a brand-new alias set. */ | |
1122 | ||
4862826d | 1123 | alias_set_type |
4682ae04 | 1124 | new_alias_set (void) |
3bdf5ad1 | 1125 | { |
bd04cddf JH |
1126 | if (alias_sets == 0) |
1127 | vec_safe_push (alias_sets, (alias_set_entry *) NULL); | |
1128 | vec_safe_push (alias_sets, (alias_set_entry *) NULL); | |
1129 | return alias_sets->length () - 1; | |
3bdf5ad1 | 1130 | } |
3932261a | 1131 | |
01d28c3f JM |
1132 | /* Indicate that things in SUBSET can alias things in SUPERSET, but that |
1133 | not everything that aliases SUPERSET also aliases SUBSET. For example, | |
1134 | in C, a store to an `int' can alias a load of a structure containing an | |
1135 | `int', and vice versa. But it can't alias a load of a 'double' member | |
1136 | of the same structure. Here, the structure would be the SUPERSET and | |
1137 | `int' the SUBSET. This relationship is also described in the comment at | |
1138 | the beginning of this file. | |
1139 | ||
1140 | This function should be called only once per SUPERSET/SUBSET pair. | |
3932261a MM |
1141 | |
1142 | It is illegal for SUPERSET to be zero; everything is implicitly a | |
1143 | subset of alias set zero. */ | |
1144 | ||
794511d2 | 1145 | void |
4862826d | 1146 | record_alias_subset (alias_set_type superset, alias_set_type subset) |
3932261a | 1147 | { |
02ced957 TS |
1148 | alias_set_entry *superset_entry; |
1149 | alias_set_entry *subset_entry; | |
3932261a | 1150 | |
f47e9b4e RK |
1151 | /* It is possible in complex type situations for both sets to be the same, |
1152 | in which case we can ignore this operation. */ | |
1153 | if (superset == subset) | |
1154 | return; | |
1155 | ||
298e6adc | 1156 | gcc_assert (superset); |
3932261a MM |
1157 | |
1158 | superset_entry = get_alias_set_entry (superset); | |
ca7fd9cd | 1159 | if (superset_entry == 0) |
3932261a MM |
1160 | { |
1161 | /* Create an entry for the SUPERSET, so that we have a place to | |
1162 | attach the SUBSET. */ | |
6e042ef4 | 1163 | superset_entry = init_alias_set_entry (superset); |
3932261a MM |
1164 | } |
1165 | ||
2bf105ab RK |
1166 | if (subset == 0) |
1167 | superset_entry->has_zero_child = 1; | |
1168 | else | |
1169 | { | |
1170 | subset_entry = get_alias_set_entry (subset); | |
6e042ef4 JH |
1171 | if (!superset_entry->children) |
1172 | superset_entry->children | |
fb5c464a | 1173 | = hash_map<alias_set_hash, int>::create_ggc (64); |
2bf105ab RK |
1174 | /* If there is an entry for the subset, enter all of its children |
1175 | (if they are not already present) as children of the SUPERSET. */ | |
ca7fd9cd | 1176 | if (subset_entry) |
2bf105ab RK |
1177 | { |
1178 | if (subset_entry->has_zero_child) | |
6e042ef4 JH |
1179 | superset_entry->has_zero_child = true; |
1180 | if (subset_entry->has_pointer) | |
1181 | superset_entry->has_pointer = true; | |
d4b60170 | 1182 | |
6e042ef4 JH |
1183 | if (subset_entry->children) |
1184 | { | |
fb5c464a | 1185 | hash_map<alias_set_hash, int>::iterator iter |
6e042ef4 JH |
1186 | = subset_entry->children->begin (); |
1187 | for (; iter != subset_entry->children->end (); ++iter) | |
1188 | superset_entry->children->put ((*iter).first, (*iter).second); | |
1189 | } | |
2bf105ab | 1190 | } |
3932261a | 1191 | |
2bf105ab | 1192 | /* Enter the SUBSET itself as a child of the SUPERSET. */ |
de144fb2 | 1193 | superset_entry->children->put (subset, 0); |
2bf105ab | 1194 | } |
3932261a MM |
1195 | } |
1196 | ||
a0c33338 RK |
1197 | /* Record that component types of TYPE, if any, are part of that type for |
1198 | aliasing purposes. For record types, we only record component types | |
b5487346 EB |
1199 | for fields that are not marked non-addressable. For array types, we |
1200 | only record the component type if it is not marked non-aliased. */ | |
a0c33338 RK |
1201 | |
1202 | void | |
4682ae04 | 1203 | record_component_aliases (tree type) |
a0c33338 | 1204 | { |
4862826d | 1205 | alias_set_type superset = get_alias_set (type); |
a0c33338 RK |
1206 | tree field; |
1207 | ||
1208 | if (superset == 0) | |
1209 | return; | |
1210 | ||
1211 | switch (TREE_CODE (type)) | |
1212 | { | |
a0c33338 RK |
1213 | case RECORD_TYPE: |
1214 | case UNION_TYPE: | |
1215 | case QUAL_UNION_TYPE: | |
910ad8de | 1216 | for (field = TYPE_FIELDS (type); field != 0; field = DECL_CHAIN (field)) |
b5487346 | 1217 | if (TREE_CODE (field) == FIELD_DECL && !DECL_NONADDRESSABLE_P (field)) |
f85d2487 JH |
1218 | { |
1219 | /* LTO type merging does not make any difference between | |
1220 | component pointer types. We may have | |
1221 | ||
1222 | struct foo {int *a;}; | |
1223 | ||
1224 | as TYPE_CANONICAL of | |
1225 | ||
1226 | struct bar {float *a;}; | |
1227 | ||
1228 | Because accesses to int * and float * do not alias, we would get | |
1229 | false negative when accessing the same memory location by | |
1230 | float ** and bar *. We thus record the canonical type as: | |
1231 | ||
1232 | struct {void *a;}; | |
1233 | ||
1234 | void * is special cased and works as a universal pointer type. | |
1235 | Accesses to it conflicts with accesses to any other pointer | |
1236 | type. */ | |
1237 | tree t = TREE_TYPE (field); | |
1238 | if (in_lto_p) | |
1239 | { | |
1240 | /* VECTOR_TYPE and ARRAY_TYPE share the alias set with their | |
1241 | element type and that type has to be normalized to void *, | |
1242 | too, in the case it is a pointer. */ | |
aea50b45 JH |
1243 | while (!canonical_type_used_p (t) && !POINTER_TYPE_P (t)) |
1244 | { | |
1245 | gcc_checking_assert (TYPE_STRUCTURAL_EQUALITY_P (t)); | |
1246 | t = TREE_TYPE (t); | |
1247 | } | |
f85d2487 JH |
1248 | if (POINTER_TYPE_P (t)) |
1249 | t = ptr_type_node; | |
aea50b45 JH |
1250 | else if (flag_checking) |
1251 | gcc_checking_assert (get_alias_set (t) | |
1252 | == get_alias_set (TREE_TYPE (field))); | |
f85d2487 | 1253 | } |
aea50b45 | 1254 | |
f85d2487 JH |
1255 | record_alias_subset (superset, get_alias_set (t)); |
1256 | } | |
a0c33338 RK |
1257 | break; |
1258 | ||
1d79fd2c JW |
1259 | case COMPLEX_TYPE: |
1260 | record_alias_subset (superset, get_alias_set (TREE_TYPE (type))); | |
1261 | break; | |
1262 | ||
4653cae5 RG |
1263 | /* VECTOR_TYPE and ARRAY_TYPE share the alias set with their |
1264 | element type. */ | |
1265 | ||
a0c33338 RK |
1266 | default: |
1267 | break; | |
1268 | } | |
1269 | } | |
1270 | ||
3bdf5ad1 RK |
1271 | /* Allocate an alias set for use in storing and reading from the varargs |
1272 | spill area. */ | |
1273 | ||
4862826d | 1274 | static GTY(()) alias_set_type varargs_set = -1; |
f103e34d | 1275 | |
4862826d | 1276 | alias_set_type |
4682ae04 | 1277 | get_varargs_alias_set (void) |
3bdf5ad1 | 1278 | { |
cd3ce9b4 JM |
1279 | #if 1 |
1280 | /* We now lower VA_ARG_EXPR, and there's currently no way to attach the | |
1281 | varargs alias set to an INDIRECT_REF (FIXME!), so we can't | |
1282 | consistently use the varargs alias set for loads from the varargs | |
1283 | area. So don't use it anywhere. */ | |
1284 | return 0; | |
1285 | #else | |
f103e34d GK |
1286 | if (varargs_set == -1) |
1287 | varargs_set = new_alias_set (); | |
3bdf5ad1 | 1288 | |
f103e34d | 1289 | return varargs_set; |
cd3ce9b4 | 1290 | #endif |
3bdf5ad1 RK |
1291 | } |
1292 | ||
1293 | /* Likewise, but used for the fixed portions of the frame, e.g., register | |
1294 | save areas. */ | |
1295 | ||
4862826d | 1296 | static GTY(()) alias_set_type frame_set = -1; |
f103e34d | 1297 | |
4862826d | 1298 | alias_set_type |
4682ae04 | 1299 | get_frame_alias_set (void) |
3bdf5ad1 | 1300 | { |
f103e34d GK |
1301 | if (frame_set == -1) |
1302 | frame_set = new_alias_set (); | |
3bdf5ad1 | 1303 | |
f103e34d | 1304 | return frame_set; |
3bdf5ad1 RK |
1305 | } |
1306 | ||
9fc37b2b RS |
1307 | /* Create a new, unique base with id ID. */ |
1308 | ||
1309 | static rtx | |
1310 | unique_base_value (HOST_WIDE_INT id) | |
1311 | { | |
1312 | return gen_rtx_ADDRESS (Pmode, id); | |
1313 | } | |
1314 | ||
1315 | /* Return true if accesses based on any other base value cannot alias | |
1316 | those based on X. */ | |
1317 | ||
1318 | static bool | |
1319 | unique_base_value_p (rtx x) | |
1320 | { | |
1321 | return GET_CODE (x) == ADDRESS && GET_MODE (x) == Pmode; | |
1322 | } | |
1323 | ||
1324 | /* Return true if X is known to be a base value. */ | |
1325 | ||
1326 | static bool | |
1327 | known_base_value_p (rtx x) | |
1328 | { | |
1329 | switch (GET_CODE (x)) | |
1330 | { | |
1331 | case LABEL_REF: | |
1332 | case SYMBOL_REF: | |
1333 | return true; | |
1334 | ||
1335 | case ADDRESS: | |
1336 | /* Arguments may or may not be bases; we don't know for sure. */ | |
1337 | return GET_MODE (x) != VOIDmode; | |
1338 | ||
1339 | default: | |
1340 | return false; | |
1341 | } | |
1342 | } | |
1343 | ||
2a2c8203 JC |
1344 | /* Inside SRC, the source of a SET, find a base address. */ |
1345 | ||
9ae8ffe7 | 1346 | static rtx |
4682ae04 | 1347 | find_base_value (rtx src) |
9ae8ffe7 | 1348 | { |
713f41f9 | 1349 | unsigned int regno; |
6645d841 | 1350 | scalar_int_mode int_mode; |
0aacc8ed | 1351 | |
53451050 RS |
1352 | #if defined (FIND_BASE_TERM) |
1353 | /* Try machine-dependent ways to find the base term. */ | |
1354 | src = FIND_BASE_TERM (src); | |
1355 | #endif | |
1356 | ||
9ae8ffe7 JL |
1357 | switch (GET_CODE (src)) |
1358 | { | |
1359 | case SYMBOL_REF: | |
1360 | case LABEL_REF: | |
1361 | return src; | |
1362 | ||
1363 | case REG: | |
fb6754f0 | 1364 | regno = REGNO (src); |
d4b60170 | 1365 | /* At the start of a function, argument registers have known base |
2a2c8203 JC |
1366 | values which may be lost later. Returning an ADDRESS |
1367 | expression here allows optimization based on argument values | |
1368 | even when the argument registers are used for other purposes. */ | |
713f41f9 BS |
1369 | if (regno < FIRST_PSEUDO_REGISTER && copying_arguments) |
1370 | return new_reg_base_value[regno]; | |
73774bc7 | 1371 | |
eaf407a5 | 1372 | /* If a pseudo has a known base value, return it. Do not do this |
9b462c42 RH |
1373 | for non-fixed hard regs since it can result in a circular |
1374 | dependency chain for registers which have values at function entry. | |
eaf407a5 JL |
1375 | |
1376 | The test above is not sufficient because the scheduler may move | |
1377 | a copy out of an arg reg past the NOTE_INSN_FUNCTION_BEGIN. */ | |
9b462c42 | 1378 | if ((regno >= FIRST_PSEUDO_REGISTER || fixed_regs[regno]) |
9771b263 | 1379 | && regno < vec_safe_length (reg_base_value)) |
83bbd9b6 RH |
1380 | { |
1381 | /* If we're inside init_alias_analysis, use new_reg_base_value | |
1382 | to reduce the number of relaxation iterations. */ | |
1afdf91c | 1383 | if (new_reg_base_value && new_reg_base_value[regno] |
6fb5fa3c | 1384 | && DF_REG_DEF_COUNT (regno) == 1) |
83bbd9b6 RH |
1385 | return new_reg_base_value[regno]; |
1386 | ||
9771b263 DN |
1387 | if ((*reg_base_value)[regno]) |
1388 | return (*reg_base_value)[regno]; | |
83bbd9b6 | 1389 | } |
73774bc7 | 1390 | |
e3f049a8 | 1391 | return 0; |
9ae8ffe7 JL |
1392 | |
1393 | case MEM: | |
1394 | /* Check for an argument passed in memory. Only record in the | |
1395 | copying-arguments block; it is too hard to track changes | |
1396 | otherwise. */ | |
1397 | if (copying_arguments | |
1398 | && (XEXP (src, 0) == arg_pointer_rtx | |
1399 | || (GET_CODE (XEXP (src, 0)) == PLUS | |
1400 | && XEXP (XEXP (src, 0), 0) == arg_pointer_rtx))) | |
9fc37b2b | 1401 | return arg_base_value; |
9ae8ffe7 JL |
1402 | return 0; |
1403 | ||
1404 | case CONST: | |
1405 | src = XEXP (src, 0); | |
1406 | if (GET_CODE (src) != PLUS && GET_CODE (src) != MINUS) | |
1407 | break; | |
d4b60170 | 1408 | |
191816a3 | 1409 | /* fall through */ |
2a2c8203 | 1410 | |
9ae8ffe7 JL |
1411 | case PLUS: |
1412 | case MINUS: | |
2a2c8203 | 1413 | { |
ec907dd8 JL |
1414 | rtx temp, src_0 = XEXP (src, 0), src_1 = XEXP (src, 1); |
1415 | ||
0134bf2d DE |
1416 | /* If either operand is a REG that is a known pointer, then it |
1417 | is the base. */ | |
1418 | if (REG_P (src_0) && REG_POINTER (src_0)) | |
1419 | return find_base_value (src_0); | |
1420 | if (REG_P (src_1) && REG_POINTER (src_1)) | |
1421 | return find_base_value (src_1); | |
1422 | ||
ec907dd8 JL |
1423 | /* If either operand is a REG, then see if we already have |
1424 | a known value for it. */ | |
0134bf2d | 1425 | if (REG_P (src_0)) |
ec907dd8 JL |
1426 | { |
1427 | temp = find_base_value (src_0); | |
d4b60170 | 1428 | if (temp != 0) |
ec907dd8 JL |
1429 | src_0 = temp; |
1430 | } | |
1431 | ||
0134bf2d | 1432 | if (REG_P (src_1)) |
ec907dd8 JL |
1433 | { |
1434 | temp = find_base_value (src_1); | |
d4b60170 | 1435 | if (temp!= 0) |
ec907dd8 JL |
1436 | src_1 = temp; |
1437 | } | |
2a2c8203 | 1438 | |
0134bf2d DE |
1439 | /* If either base is named object or a special address |
1440 | (like an argument or stack reference), then use it for the | |
1441 | base term. */ | |
9fc37b2b | 1442 | if (src_0 != 0 && known_base_value_p (src_0)) |
0134bf2d DE |
1443 | return src_0; |
1444 | ||
9fc37b2b | 1445 | if (src_1 != 0 && known_base_value_p (src_1)) |
0134bf2d DE |
1446 | return src_1; |
1447 | ||
d4b60170 | 1448 | /* Guess which operand is the base address: |
ec907dd8 JL |
1449 | If either operand is a symbol, then it is the base. If |
1450 | either operand is a CONST_INT, then the other is the base. */ | |
481683e1 | 1451 | if (CONST_INT_P (src_1) || CONSTANT_P (src_0)) |
2a2c8203 | 1452 | return find_base_value (src_0); |
481683e1 | 1453 | else if (CONST_INT_P (src_0) || CONSTANT_P (src_1)) |
ec907dd8 JL |
1454 | return find_base_value (src_1); |
1455 | ||
9ae8ffe7 | 1456 | return 0; |
2a2c8203 JC |
1457 | } |
1458 | ||
1459 | case LO_SUM: | |
1460 | /* The standard form is (lo_sum reg sym) so look only at the | |
1461 | second operand. */ | |
1462 | return find_base_value (XEXP (src, 1)); | |
9ae8ffe7 JL |
1463 | |
1464 | case AND: | |
1465 | /* If the second operand is constant set the base | |
ec5c56db | 1466 | address to the first operand. */ |
481683e1 | 1467 | if (CONST_INT_P (XEXP (src, 1)) && INTVAL (XEXP (src, 1)) != 0) |
2a2c8203 | 1468 | return find_base_value (XEXP (src, 0)); |
9ae8ffe7 JL |
1469 | return 0; |
1470 | ||
61f0131c | 1471 | case TRUNCATE: |
5932a4d4 | 1472 | /* As we do not know which address space the pointer is referring to, we can |
d4ebfa65 BE |
1473 | handle this only if the target does not support different pointer or |
1474 | address modes depending on the address space. */ | |
1475 | if (!target_default_pointer_address_modes_p ()) | |
1476 | break; | |
6645d841 RS |
1477 | if (!is_a <scalar_int_mode> (GET_MODE (src), &int_mode) |
1478 | || GET_MODE_PRECISION (int_mode) < GET_MODE_PRECISION (Pmode)) | |
61f0131c R |
1479 | break; |
1480 | /* Fall through. */ | |
9ae8ffe7 | 1481 | case HIGH: |
d288e53d DE |
1482 | case PRE_INC: |
1483 | case PRE_DEC: | |
1484 | case POST_INC: | |
1485 | case POST_DEC: | |
1486 | case PRE_MODIFY: | |
1487 | case POST_MODIFY: | |
2a2c8203 | 1488 | return find_base_value (XEXP (src, 0)); |
1d300e19 | 1489 | |
0aacc8ed RK |
1490 | case ZERO_EXTEND: |
1491 | case SIGN_EXTEND: /* used for NT/Alpha pointers */ | |
5932a4d4 | 1492 | /* As we do not know which address space the pointer is referring to, we can |
d4ebfa65 BE |
1493 | handle this only if the target does not support different pointer or |
1494 | address modes depending on the address space. */ | |
1495 | if (!target_default_pointer_address_modes_p ()) | |
1496 | break; | |
1497 | ||
0aacc8ed RK |
1498 | { |
1499 | rtx temp = find_base_value (XEXP (src, 0)); | |
1500 | ||
5ae6cd0d | 1501 | if (temp != 0 && CONSTANT_P (temp)) |
0aacc8ed | 1502 | temp = convert_memory_address (Pmode, temp); |
0aacc8ed RK |
1503 | |
1504 | return temp; | |
1505 | } | |
1506 | ||
1d300e19 KG |
1507 | default: |
1508 | break; | |
9ae8ffe7 JL |
1509 | } |
1510 | ||
1511 | return 0; | |
1512 | } | |
1513 | ||
9fc37b2b RS |
1514 | /* Called from init_alias_analysis indirectly through note_stores, |
1515 | or directly if DEST is a register with a REG_NOALIAS note attached. | |
1516 | SET is null in the latter case. */ | |
9ae8ffe7 | 1517 | |
d4b60170 | 1518 | /* While scanning insns to find base values, reg_seen[N] is nonzero if |
9ae8ffe7 | 1519 | register N has been set in this function. */ |
d630245f | 1520 | static sbitmap reg_seen; |
9ae8ffe7 | 1521 | |
2a2c8203 | 1522 | static void |
7bc980e1 | 1523 | record_set (rtx dest, const_rtx set, void *data ATTRIBUTE_UNUSED) |
9ae8ffe7 | 1524 | { |
b3694847 | 1525 | unsigned regno; |
9ae8ffe7 | 1526 | rtx src; |
c28b4e40 | 1527 | int n; |
9ae8ffe7 | 1528 | |
f8cfc6aa | 1529 | if (!REG_P (dest)) |
9ae8ffe7 JL |
1530 | return; |
1531 | ||
fb6754f0 | 1532 | regno = REGNO (dest); |
9ae8ffe7 | 1533 | |
9771b263 | 1534 | gcc_checking_assert (regno < reg_base_value->length ()); |
ac606739 | 1535 | |
dc8afb70 | 1536 | n = REG_NREGS (dest); |
c28b4e40 JW |
1537 | if (n != 1) |
1538 | { | |
1539 | while (--n >= 0) | |
1540 | { | |
d7c028c0 | 1541 | bitmap_set_bit (reg_seen, regno + n); |
c28b4e40 JW |
1542 | new_reg_base_value[regno + n] = 0; |
1543 | } | |
1544 | return; | |
1545 | } | |
1546 | ||
9ae8ffe7 JL |
1547 | if (set) |
1548 | { | |
1549 | /* A CLOBBER wipes out any old value but does not prevent a previously | |
1550 | unset register from acquiring a base address (i.e. reg_seen is not | |
1551 | set). */ | |
1552 | if (GET_CODE (set) == CLOBBER) | |
1553 | { | |
ec907dd8 | 1554 | new_reg_base_value[regno] = 0; |
9ae8ffe7 JL |
1555 | return; |
1556 | } | |
1557 | src = SET_SRC (set); | |
1558 | } | |
1559 | else | |
1560 | { | |
9fc37b2b | 1561 | /* There's a REG_NOALIAS note against DEST. */ |
d7c028c0 | 1562 | if (bitmap_bit_p (reg_seen, regno)) |
9ae8ffe7 | 1563 | { |
ec907dd8 | 1564 | new_reg_base_value[regno] = 0; |
9ae8ffe7 JL |
1565 | return; |
1566 | } | |
d7c028c0 | 1567 | bitmap_set_bit (reg_seen, regno); |
9fc37b2b | 1568 | new_reg_base_value[regno] = unique_base_value (unique_id++); |
9ae8ffe7 JL |
1569 | return; |
1570 | } | |
1571 | ||
5da6f168 RS |
1572 | /* If this is not the first set of REGNO, see whether the new value |
1573 | is related to the old one. There are two cases of interest: | |
1574 | ||
1575 | (1) The register might be assigned an entirely new value | |
1576 | that has the same base term as the original set. | |
1577 | ||
1578 | (2) The set might be a simple self-modification that | |
1579 | cannot change REGNO's base value. | |
1580 | ||
1581 | If neither case holds, reject the original base value as invalid. | |
1582 | Note that the following situation is not detected: | |
1583 | ||
c22cacf3 | 1584 | extern int x, y; int *p = &x; p += (&y-&x); |
5da6f168 | 1585 | |
9ae8ffe7 JL |
1586 | ANSI C does not allow computing the difference of addresses |
1587 | of distinct top level objects. */ | |
5da6f168 RS |
1588 | if (new_reg_base_value[regno] != 0 |
1589 | && find_base_value (src) != new_reg_base_value[regno]) | |
9ae8ffe7 JL |
1590 | switch (GET_CODE (src)) |
1591 | { | |
2a2c8203 | 1592 | case LO_SUM: |
9ae8ffe7 JL |
1593 | case MINUS: |
1594 | if (XEXP (src, 0) != dest && XEXP (src, 1) != dest) | |
ec907dd8 | 1595 | new_reg_base_value[regno] = 0; |
9ae8ffe7 | 1596 | break; |
61f0131c R |
1597 | case PLUS: |
1598 | /* If the value we add in the PLUS is also a valid base value, | |
1599 | this might be the actual base value, and the original value | |
1600 | an index. */ | |
1601 | { | |
1602 | rtx other = NULL_RTX; | |
1603 | ||
1604 | if (XEXP (src, 0) == dest) | |
1605 | other = XEXP (src, 1); | |
1606 | else if (XEXP (src, 1) == dest) | |
1607 | other = XEXP (src, 0); | |
1608 | ||
1609 | if (! other || find_base_value (other)) | |
1610 | new_reg_base_value[regno] = 0; | |
1611 | break; | |
1612 | } | |
9ae8ffe7 | 1613 | case AND: |
481683e1 | 1614 | if (XEXP (src, 0) != dest || !CONST_INT_P (XEXP (src, 1))) |
ec907dd8 | 1615 | new_reg_base_value[regno] = 0; |
9ae8ffe7 | 1616 | break; |
9ae8ffe7 | 1617 | default: |
ec907dd8 | 1618 | new_reg_base_value[regno] = 0; |
9ae8ffe7 JL |
1619 | break; |
1620 | } | |
1621 | /* If this is the first set of a register, record the value. */ | |
1622 | else if ((regno >= FIRST_PSEUDO_REGISTER || ! fixed_regs[regno]) | |
d7c028c0 | 1623 | && ! bitmap_bit_p (reg_seen, regno) && new_reg_base_value[regno] == 0) |
ec907dd8 | 1624 | new_reg_base_value[regno] = find_base_value (src); |
9ae8ffe7 | 1625 | |
d7c028c0 | 1626 | bitmap_set_bit (reg_seen, regno); |
9ae8ffe7 JL |
1627 | } |
1628 | ||
8fd0a474 AM |
1629 | /* Return REG_BASE_VALUE for REGNO. Selective scheduler uses this to avoid |
1630 | using hard registers with non-null REG_BASE_VALUE for renaming. */ | |
1631 | rtx | |
1632 | get_reg_base_value (unsigned int regno) | |
1633 | { | |
9771b263 | 1634 | return (*reg_base_value)[regno]; |
8fd0a474 AM |
1635 | } |
1636 | ||
bb1acb3e RH |
1637 | /* If a value is known for REGNO, return it. */ |
1638 | ||
c22cacf3 | 1639 | rtx |
bb1acb3e RH |
1640 | get_reg_known_value (unsigned int regno) |
1641 | { | |
1642 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1643 | { | |
1644 | regno -= FIRST_PSEUDO_REGISTER; | |
9771b263 DN |
1645 | if (regno < vec_safe_length (reg_known_value)) |
1646 | return (*reg_known_value)[regno]; | |
bb1acb3e RH |
1647 | } |
1648 | return NULL; | |
43fe47ca JW |
1649 | } |
1650 | ||
bb1acb3e RH |
1651 | /* Set it. */ |
1652 | ||
1653 | static void | |
1654 | set_reg_known_value (unsigned int regno, rtx val) | |
1655 | { | |
1656 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1657 | { | |
1658 | regno -= FIRST_PSEUDO_REGISTER; | |
9771b263 DN |
1659 | if (regno < vec_safe_length (reg_known_value)) |
1660 | (*reg_known_value)[regno] = val; | |
bb1acb3e RH |
1661 | } |
1662 | } | |
1663 | ||
1664 | /* Similarly for reg_known_equiv_p. */ | |
1665 | ||
1666 | bool | |
1667 | get_reg_known_equiv_p (unsigned int regno) | |
1668 | { | |
1669 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1670 | { | |
1671 | regno -= FIRST_PSEUDO_REGISTER; | |
9771b263 | 1672 | if (regno < vec_safe_length (reg_known_value)) |
d7c028c0 | 1673 | return bitmap_bit_p (reg_known_equiv_p, regno); |
bb1acb3e RH |
1674 | } |
1675 | return false; | |
1676 | } | |
1677 | ||
1678 | static void | |
1679 | set_reg_known_equiv_p (unsigned int regno, bool val) | |
1680 | { | |
1681 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1682 | { | |
1683 | regno -= FIRST_PSEUDO_REGISTER; | |
9771b263 | 1684 | if (regno < vec_safe_length (reg_known_value)) |
9ff3c7ca SB |
1685 | { |
1686 | if (val) | |
d7c028c0 | 1687 | bitmap_set_bit (reg_known_equiv_p, regno); |
9ff3c7ca | 1688 | else |
d7c028c0 | 1689 | bitmap_clear_bit (reg_known_equiv_p, regno); |
9ff3c7ca | 1690 | } |
bb1acb3e RH |
1691 | } |
1692 | } | |
1693 | ||
1694 | ||
db048faf MM |
1695 | /* Returns a canonical version of X, from the point of view alias |
1696 | analysis. (For example, if X is a MEM whose address is a register, | |
1697 | and the register has a known value (say a SYMBOL_REF), then a MEM | |
1698 | whose address is the SYMBOL_REF is returned.) */ | |
1699 | ||
1700 | rtx | |
4682ae04 | 1701 | canon_rtx (rtx x) |
9ae8ffe7 JL |
1702 | { |
1703 | /* Recursively look for equivalences. */ | |
f8cfc6aa | 1704 | if (REG_P (x) && REGNO (x) >= FIRST_PSEUDO_REGISTER) |
bb1acb3e RH |
1705 | { |
1706 | rtx t = get_reg_known_value (REGNO (x)); | |
1707 | if (t == x) | |
1708 | return x; | |
1709 | if (t) | |
1710 | return canon_rtx (t); | |
1711 | } | |
1712 | ||
1713 | if (GET_CODE (x) == PLUS) | |
9ae8ffe7 JL |
1714 | { |
1715 | rtx x0 = canon_rtx (XEXP (x, 0)); | |
1716 | rtx x1 = canon_rtx (XEXP (x, 1)); | |
1717 | ||
1718 | if (x0 != XEXP (x, 0) || x1 != XEXP (x, 1)) | |
231314e3 | 1719 | return simplify_gen_binary (PLUS, GET_MODE (x), x0, x1); |
9ae8ffe7 | 1720 | } |
d4b60170 | 1721 | |
9ae8ffe7 JL |
1722 | /* This gives us much better alias analysis when called from |
1723 | the loop optimizer. Note we want to leave the original | |
1724 | MEM alone, but need to return the canonicalized MEM with | |
1725 | all the flags with their original values. */ | |
3c0cb5de | 1726 | else if (MEM_P (x)) |
f1ec5147 | 1727 | x = replace_equiv_address_nv (x, canon_rtx (XEXP (x, 0))); |
d4b60170 | 1728 | |
9ae8ffe7 JL |
1729 | return x; |
1730 | } | |
1731 | ||
1732 | /* Return 1 if X and Y are identical-looking rtx's. | |
45183e03 | 1733 | Expect that X and Y has been already canonicalized. |
9ae8ffe7 JL |
1734 | |
1735 | We use the data in reg_known_value above to see if two registers with | |
1736 | different numbers are, in fact, equivalent. */ | |
1737 | ||
1738 | static int | |
ed7a4b4b | 1739 | rtx_equal_for_memref_p (const_rtx x, const_rtx y) |
9ae8ffe7 | 1740 | { |
b3694847 SS |
1741 | int i; |
1742 | int j; | |
1743 | enum rtx_code code; | |
1744 | const char *fmt; | |
9ae8ffe7 JL |
1745 | |
1746 | if (x == 0 && y == 0) | |
1747 | return 1; | |
1748 | if (x == 0 || y == 0) | |
1749 | return 0; | |
d4b60170 | 1750 | |
9ae8ffe7 JL |
1751 | if (x == y) |
1752 | return 1; | |
1753 | ||
1754 | code = GET_CODE (x); | |
1755 | /* Rtx's of different codes cannot be equal. */ | |
1756 | if (code != GET_CODE (y)) | |
1757 | return 0; | |
1758 | ||
1759 | /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. | |
1760 | (REG:SI x) and (REG:HI x) are NOT equivalent. */ | |
1761 | ||
1762 | if (GET_MODE (x) != GET_MODE (y)) | |
1763 | return 0; | |
1764 | ||
db048faf MM |
1765 | /* Some RTL can be compared without a recursive examination. */ |
1766 | switch (code) | |
1767 | { | |
1768 | case REG: | |
1769 | return REGNO (x) == REGNO (y); | |
1770 | ||
1771 | case LABEL_REF: | |
04a121a7 | 1772 | return label_ref_label (x) == label_ref_label (y); |
ca7fd9cd | 1773 | |
db048faf | 1774 | case SYMBOL_REF: |
73e48cb3 | 1775 | return compare_base_symbol_refs (x, y) == 1; |
db048faf | 1776 | |
af6236c1 AO |
1777 | case ENTRY_VALUE: |
1778 | /* This is magic, don't go through canonicalization et al. */ | |
1779 | return rtx_equal_p (ENTRY_VALUE_EXP (x), ENTRY_VALUE_EXP (y)); | |
1780 | ||
40e02b4a | 1781 | case VALUE: |
d8116890 | 1782 | CASE_CONST_UNIQUE: |
807e902e | 1783 | /* Pointer equality guarantees equality for these nodes. */ |
db048faf MM |
1784 | return 0; |
1785 | ||
db048faf MM |
1786 | default: |
1787 | break; | |
1788 | } | |
9ae8ffe7 | 1789 | |
45183e03 JH |
1790 | /* canon_rtx knows how to handle plus. No need to canonicalize. */ |
1791 | if (code == PLUS) | |
9ae8ffe7 JL |
1792 | return ((rtx_equal_for_memref_p (XEXP (x, 0), XEXP (y, 0)) |
1793 | && rtx_equal_for_memref_p (XEXP (x, 1), XEXP (y, 1))) | |
1794 | || (rtx_equal_for_memref_p (XEXP (x, 0), XEXP (y, 1)) | |
1795 | && rtx_equal_for_memref_p (XEXP (x, 1), XEXP (y, 0)))); | |
45183e03 JH |
1796 | /* For commutative operations, the RTX match if the operand match in any |
1797 | order. Also handle the simple binary and unary cases without a loop. */ | |
ec8e098d | 1798 | if (COMMUTATIVE_P (x)) |
45183e03 JH |
1799 | { |
1800 | rtx xop0 = canon_rtx (XEXP (x, 0)); | |
1801 | rtx yop0 = canon_rtx (XEXP (y, 0)); | |
1802 | rtx yop1 = canon_rtx (XEXP (y, 1)); | |
1803 | ||
1804 | return ((rtx_equal_for_memref_p (xop0, yop0) | |
1805 | && rtx_equal_for_memref_p (canon_rtx (XEXP (x, 1)), yop1)) | |
1806 | || (rtx_equal_for_memref_p (xop0, yop1) | |
1807 | && rtx_equal_for_memref_p (canon_rtx (XEXP (x, 1)), yop0))); | |
1808 | } | |
ec8e098d | 1809 | else if (NON_COMMUTATIVE_P (x)) |
45183e03 JH |
1810 | { |
1811 | return (rtx_equal_for_memref_p (canon_rtx (XEXP (x, 0)), | |
4682ae04 | 1812 | canon_rtx (XEXP (y, 0))) |
45183e03 JH |
1813 | && rtx_equal_for_memref_p (canon_rtx (XEXP (x, 1)), |
1814 | canon_rtx (XEXP (y, 1)))); | |
1815 | } | |
ec8e098d | 1816 | else if (UNARY_P (x)) |
45183e03 | 1817 | return rtx_equal_for_memref_p (canon_rtx (XEXP (x, 0)), |
4682ae04 | 1818 | canon_rtx (XEXP (y, 0))); |
9ae8ffe7 JL |
1819 | |
1820 | /* Compare the elements. If any pair of corresponding elements | |
de12be17 JC |
1821 | fail to match, return 0 for the whole things. |
1822 | ||
1823 | Limit cases to types which actually appear in addresses. */ | |
9ae8ffe7 JL |
1824 | |
1825 | fmt = GET_RTX_FORMAT (code); | |
1826 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
1827 | { | |
1828 | switch (fmt[i]) | |
1829 | { | |
9ae8ffe7 JL |
1830 | case 'i': |
1831 | if (XINT (x, i) != XINT (y, i)) | |
1832 | return 0; | |
1833 | break; | |
1834 | ||
91914e56 RS |
1835 | case 'p': |
1836 | if (maybe_ne (SUBREG_BYTE (x), SUBREG_BYTE (y))) | |
1837 | return 0; | |
1838 | break; | |
1839 | ||
9ae8ffe7 JL |
1840 | case 'E': |
1841 | /* Two vectors must have the same length. */ | |
1842 | if (XVECLEN (x, i) != XVECLEN (y, i)) | |
1843 | return 0; | |
1844 | ||
1845 | /* And the corresponding elements must match. */ | |
1846 | for (j = 0; j < XVECLEN (x, i); j++) | |
45183e03 JH |
1847 | if (rtx_equal_for_memref_p (canon_rtx (XVECEXP (x, i, j)), |
1848 | canon_rtx (XVECEXP (y, i, j))) == 0) | |
9ae8ffe7 JL |
1849 | return 0; |
1850 | break; | |
1851 | ||
1852 | case 'e': | |
45183e03 JH |
1853 | if (rtx_equal_for_memref_p (canon_rtx (XEXP (x, i)), |
1854 | canon_rtx (XEXP (y, i))) == 0) | |
9ae8ffe7 JL |
1855 | return 0; |
1856 | break; | |
1857 | ||
3237ac18 AH |
1858 | /* This can happen for asm operands. */ |
1859 | case 's': | |
1860 | if (strcmp (XSTR (x, i), XSTR (y, i))) | |
1861 | return 0; | |
1862 | break; | |
1863 | ||
aee21ba9 JL |
1864 | /* This can happen for an asm which clobbers memory. */ |
1865 | case '0': | |
1866 | break; | |
1867 | ||
9ae8ffe7 JL |
1868 | /* It is believed that rtx's at this level will never |
1869 | contain anything but integers and other rtx's, | |
1870 | except for within LABEL_REFs and SYMBOL_REFs. */ | |
1871 | default: | |
298e6adc | 1872 | gcc_unreachable (); |
9ae8ffe7 JL |
1873 | } |
1874 | } | |
1875 | return 1; | |
1876 | } | |
1877 | ||
9e412ca3 | 1878 | static rtx |
4682ae04 | 1879 | find_base_term (rtx x) |
9ae8ffe7 | 1880 | { |
eab5c70a | 1881 | cselib_val *val; |
6f2ffb4b AO |
1882 | struct elt_loc_list *l, *f; |
1883 | rtx ret; | |
6645d841 | 1884 | scalar_int_mode int_mode; |
eab5c70a | 1885 | |
b949ea8b JW |
1886 | #if defined (FIND_BASE_TERM) |
1887 | /* Try machine-dependent ways to find the base term. */ | |
1888 | x = FIND_BASE_TERM (x); | |
1889 | #endif | |
1890 | ||
9ae8ffe7 JL |
1891 | switch (GET_CODE (x)) |
1892 | { | |
1893 | case REG: | |
1894 | return REG_BASE_VALUE (x); | |
1895 | ||
d288e53d | 1896 | case TRUNCATE: |
5932a4d4 | 1897 | /* As we do not know which address space the pointer is referring to, we can |
d4ebfa65 BE |
1898 | handle this only if the target does not support different pointer or |
1899 | address modes depending on the address space. */ | |
1900 | if (!target_default_pointer_address_modes_p ()) | |
1901 | return 0; | |
6645d841 RS |
1902 | if (!is_a <scalar_int_mode> (GET_MODE (x), &int_mode) |
1903 | || GET_MODE_PRECISION (int_mode) < GET_MODE_PRECISION (Pmode)) | |
ca7fd9cd | 1904 | return 0; |
d288e53d | 1905 | /* Fall through. */ |
9ae8ffe7 | 1906 | case HIGH: |
6d849a2a JL |
1907 | case PRE_INC: |
1908 | case PRE_DEC: | |
1909 | case POST_INC: | |
1910 | case POST_DEC: | |
d288e53d DE |
1911 | case PRE_MODIFY: |
1912 | case POST_MODIFY: | |
6d849a2a JL |
1913 | return find_base_term (XEXP (x, 0)); |
1914 | ||
1abade85 RK |
1915 | case ZERO_EXTEND: |
1916 | case SIGN_EXTEND: /* Used for Alpha/NT pointers */ | |
5932a4d4 | 1917 | /* As we do not know which address space the pointer is referring to, we can |
d4ebfa65 BE |
1918 | handle this only if the target does not support different pointer or |
1919 | address modes depending on the address space. */ | |
1920 | if (!target_default_pointer_address_modes_p ()) | |
1921 | return 0; | |
1922 | ||
1abade85 RK |
1923 | { |
1924 | rtx temp = find_base_term (XEXP (x, 0)); | |
1925 | ||
5ae6cd0d | 1926 | if (temp != 0 && CONSTANT_P (temp)) |
1abade85 | 1927 | temp = convert_memory_address (Pmode, temp); |
1abade85 RK |
1928 | |
1929 | return temp; | |
1930 | } | |
1931 | ||
eab5c70a BS |
1932 | case VALUE: |
1933 | val = CSELIB_VAL_PTR (x); | |
6f2ffb4b AO |
1934 | ret = NULL_RTX; |
1935 | ||
40e02b4a | 1936 | if (!val) |
6f2ffb4b AO |
1937 | return ret; |
1938 | ||
0fe03ac3 JJ |
1939 | if (cselib_sp_based_value_p (val)) |
1940 | return static_reg_base_value[STACK_POINTER_REGNUM]; | |
1941 | ||
6f2ffb4b AO |
1942 | f = val->locs; |
1943 | /* Temporarily reset val->locs to avoid infinite recursion. */ | |
1944 | val->locs = NULL; | |
1945 | ||
1946 | for (l = f; l; l = l->next) | |
1947 | if (GET_CODE (l->loc) == VALUE | |
1948 | && CSELIB_VAL_PTR (l->loc)->locs | |
1949 | && !CSELIB_VAL_PTR (l->loc)->locs->next | |
1950 | && CSELIB_VAL_PTR (l->loc)->locs->loc == x) | |
1951 | continue; | |
1952 | else if ((ret = find_base_term (l->loc)) != 0) | |
1953 | break; | |
1954 | ||
1955 | val->locs = f; | |
1956 | return ret; | |
eab5c70a | 1957 | |
023f059b JJ |
1958 | case LO_SUM: |
1959 | /* The standard form is (lo_sum reg sym) so look only at the | |
1960 | second operand. */ | |
1961 | return find_base_term (XEXP (x, 1)); | |
1962 | ||
9ae8ffe7 JL |
1963 | case CONST: |
1964 | x = XEXP (x, 0); | |
1965 | if (GET_CODE (x) != PLUS && GET_CODE (x) != MINUS) | |
1966 | return 0; | |
938d968e | 1967 | /* Fall through. */ |
9ae8ffe7 JL |
1968 | case PLUS: |
1969 | case MINUS: | |
1970 | { | |
3c567fae JL |
1971 | rtx tmp1 = XEXP (x, 0); |
1972 | rtx tmp2 = XEXP (x, 1); | |
1973 | ||
f5143c46 | 1974 | /* This is a little bit tricky since we have to determine which of |
3c567fae JL |
1975 | the two operands represents the real base address. Otherwise this |
1976 | routine may return the index register instead of the base register. | |
1977 | ||
1978 | That may cause us to believe no aliasing was possible, when in | |
1979 | fact aliasing is possible. | |
1980 | ||
1981 | We use a few simple tests to guess the base register. Additional | |
1982 | tests can certainly be added. For example, if one of the operands | |
1983 | is a shift or multiply, then it must be the index register and the | |
1984 | other operand is the base register. */ | |
ca7fd9cd | 1985 | |
b949ea8b JW |
1986 | if (tmp1 == pic_offset_table_rtx && CONSTANT_P (tmp2)) |
1987 | return find_base_term (tmp2); | |
1988 | ||
31b0a960 | 1989 | /* If either operand is known to be a pointer, then prefer it |
3c567fae | 1990 | to determine the base term. */ |
3502dc9c | 1991 | if (REG_P (tmp1) && REG_POINTER (tmp1)) |
31b0a960 RB |
1992 | ; |
1993 | else if (REG_P (tmp2) && REG_POINTER (tmp2)) | |
a7c75343 JJ |
1994 | std::swap (tmp1, tmp2); |
1995 | /* If second argument is constant which has base term, prefer it | |
1996 | over variable tmp1. See PR64025. */ | |
1997 | else if (CONSTANT_P (tmp2) && !CONST_INT_P (tmp2)) | |
1998 | std::swap (tmp1, tmp2); | |
3c567fae | 1999 | |
31b0a960 RB |
2000 | /* Go ahead and find the base term for both operands. If either base |
2001 | term is from a pointer or is a named object or a special address | |
3c567fae JL |
2002 | (like an argument or stack reference), then use it for the |
2003 | base term. */ | |
481be1c4 RB |
2004 | rtx base = find_base_term (tmp1); |
2005 | if (base != NULL_RTX | |
31b0a960 | 2006 | && ((REG_P (tmp1) && REG_POINTER (tmp1)) |
481be1c4 RB |
2007 | || known_base_value_p (base))) |
2008 | return base; | |
2009 | base = find_base_term (tmp2); | |
2010 | if (base != NULL_RTX | |
31b0a960 | 2011 | && ((REG_P (tmp2) && REG_POINTER (tmp2)) |
481be1c4 RB |
2012 | || known_base_value_p (base))) |
2013 | return base; | |
3c567fae JL |
2014 | |
2015 | /* We could not determine which of the two operands was the | |
2016 | base register and which was the index. So we can determine | |
2017 | nothing from the base alias check. */ | |
2018 | return 0; | |
9ae8ffe7 JL |
2019 | } |
2020 | ||
2021 | case AND: | |
481683e1 | 2022 | if (CONST_INT_P (XEXP (x, 1)) && INTVAL (XEXP (x, 1)) != 0) |
d288e53d | 2023 | return find_base_term (XEXP (x, 0)); |
9ae8ffe7 JL |
2024 | return 0; |
2025 | ||
2026 | case SYMBOL_REF: | |
2027 | case LABEL_REF: | |
2028 | return x; | |
2029 | ||
2030 | default: | |
2031 | return 0; | |
2032 | } | |
2033 | } | |
2034 | ||
9e412ca3 RS |
2035 | /* Return true if accesses to address X may alias accesses based |
2036 | on the stack pointer. */ | |
2037 | ||
2038 | bool | |
2039 | may_be_sp_based_p (rtx x) | |
2040 | { | |
2041 | rtx base = find_base_term (x); | |
2042 | return !base || base == static_reg_base_value[STACK_POINTER_REGNUM]; | |
2043 | } | |
2044 | ||
54363f8a JH |
2045 | /* BASE1 and BASE2 are decls. Return 1 if they refer to same object, 0 |
2046 | if they refer to different objects and -1 if we can not decide. */ | |
2047 | ||
2048 | int | |
2049 | compare_base_decls (tree base1, tree base2) | |
2050 | { | |
2051 | int ret; | |
2052 | gcc_checking_assert (DECL_P (base1) && DECL_P (base2)); | |
2053 | if (base1 == base2) | |
2054 | return 1; | |
2055 | ||
bed3fd46 | 2056 | /* If we have two register decls with register specification we |
816c4ba2 | 2057 | cannot decide unless their assembler names are the same. */ |
bed3fd46 RB |
2058 | if (DECL_REGISTER (base1) |
2059 | && DECL_REGISTER (base2) | |
816c4ba2 NS |
2060 | && HAS_DECL_ASSEMBLER_NAME_P (base1) |
2061 | && HAS_DECL_ASSEMBLER_NAME_P (base2) | |
bed3fd46 RB |
2062 | && DECL_ASSEMBLER_NAME_SET_P (base1) |
2063 | && DECL_ASSEMBLER_NAME_SET_P (base2)) | |
2064 | { | |
816c4ba2 | 2065 | if (DECL_ASSEMBLER_NAME_RAW (base1) == DECL_ASSEMBLER_NAME_RAW (base2)) |
bed3fd46 RB |
2066 | return 1; |
2067 | return -1; | |
2068 | } | |
2069 | ||
54363f8a JH |
2070 | /* Declarations of non-automatic variables may have aliases. All other |
2071 | decls are unique. */ | |
7ec4f343 NS |
2072 | if (!decl_in_symtab_p (base1) |
2073 | || !decl_in_symtab_p (base2)) | |
54363f8a | 2074 | return 0; |
7ec4f343 | 2075 | |
929710d9 NS |
2076 | /* Don't cause symbols to be inserted by the act of checking. */ |
2077 | symtab_node *node1 = symtab_node::get (base1); | |
2078 | if (!node1) | |
2079 | return 0; | |
2080 | symtab_node *node2 = symtab_node::get (base2); | |
2081 | if (!node2) | |
2082 | return 0; | |
2083 | ||
2084 | ret = node1->equal_address_to (node2, true); | |
54363f8a JH |
2085 | return ret; |
2086 | } | |
2087 | ||
73e48cb3 JH |
2088 | /* Same as compare_base_decls but for SYMBOL_REF. */ |
2089 | ||
2090 | static int | |
2091 | compare_base_symbol_refs (const_rtx x_base, const_rtx y_base) | |
2092 | { | |
2093 | tree x_decl = SYMBOL_REF_DECL (x_base); | |
2094 | tree y_decl = SYMBOL_REF_DECL (y_base); | |
2095 | bool binds_def = true; | |
2096 | ||
2097 | if (XSTR (x_base, 0) == XSTR (y_base, 0)) | |
2098 | return 1; | |
2099 | if (x_decl && y_decl) | |
2100 | return compare_base_decls (x_decl, y_decl); | |
2101 | if (x_decl || y_decl) | |
2102 | { | |
2103 | if (!x_decl) | |
2104 | { | |
2105 | std::swap (x_decl, y_decl); | |
2106 | std::swap (x_base, y_base); | |
2107 | } | |
2108 | /* We handle specially only section anchors and assume that other | |
2109 | labels may overlap with user variables in an arbitrary way. */ | |
2110 | if (!SYMBOL_REF_HAS_BLOCK_INFO_P (y_base)) | |
2111 | return -1; | |
2112 | /* Anchors contains static VAR_DECLs and CONST_DECLs. We are safe | |
2113 | to ignore CONST_DECLs because they are readonly. */ | |
8813a647 | 2114 | if (!VAR_P (x_decl) |
73e48cb3 JH |
2115 | || (!TREE_STATIC (x_decl) && !TREE_PUBLIC (x_decl))) |
2116 | return 0; | |
2117 | ||
2118 | symtab_node *x_node = symtab_node::get_create (x_decl) | |
2119 | ->ultimate_alias_target (); | |
2120 | /* External variable can not be in section anchor. */ | |
2121 | if (!x_node->definition) | |
2122 | return 0; | |
2123 | x_base = XEXP (DECL_RTL (x_node->decl), 0); | |
2124 | /* If not in anchor, we can disambiguate. */ | |
2125 | if (!SYMBOL_REF_HAS_BLOCK_INFO_P (x_base)) | |
2126 | return 0; | |
2127 | ||
2128 | /* We have an alias of anchored variable. If it can be interposed; | |
2129 | we must assume it may or may not alias its anchor. */ | |
2130 | binds_def = decl_binds_to_current_def_p (x_decl); | |
2131 | } | |
2132 | /* If we have variable in section anchor, we can compare by offset. */ | |
2133 | if (SYMBOL_REF_HAS_BLOCK_INFO_P (x_base) | |
2134 | && SYMBOL_REF_HAS_BLOCK_INFO_P (y_base)) | |
2135 | { | |
2136 | if (SYMBOL_REF_BLOCK (x_base) != SYMBOL_REF_BLOCK (y_base)) | |
2137 | return 0; | |
2138 | if (SYMBOL_REF_BLOCK_OFFSET (x_base) == SYMBOL_REF_BLOCK_OFFSET (y_base)) | |
2139 | return binds_def ? 1 : -1; | |
2140 | if (SYMBOL_REF_ANCHOR_P (x_base) != SYMBOL_REF_ANCHOR_P (y_base)) | |
2141 | return -1; | |
2142 | return 0; | |
2143 | } | |
2144 | /* In general we assume that memory locations pointed to by different labels | |
2145 | may overlap in undefined ways. */ | |
2146 | return -1; | |
2147 | } | |
2148 | ||
9ae8ffe7 JL |
2149 | /* Return 0 if the addresses X and Y are known to point to different |
2150 | objects, 1 if they might be pointers to the same object. */ | |
2151 | ||
2152 | static int | |
31b0a960 | 2153 | base_alias_check (rtx x, rtx x_base, rtx y, rtx y_base, |
ef4bddc2 | 2154 | machine_mode x_mode, machine_mode y_mode) |
9ae8ffe7 | 2155 | { |
1c72c7f6 JC |
2156 | /* If the address itself has no known base see if a known equivalent |
2157 | value has one. If either address still has no known base, nothing | |
2158 | is known about aliasing. */ | |
2159 | if (x_base == 0) | |
2160 | { | |
2161 | rtx x_c; | |
d4b60170 | 2162 | |
1c72c7f6 JC |
2163 | if (! flag_expensive_optimizations || (x_c = canon_rtx (x)) == x) |
2164 | return 1; | |
d4b60170 | 2165 | |
1c72c7f6 JC |
2166 | x_base = find_base_term (x_c); |
2167 | if (x_base == 0) | |
2168 | return 1; | |
2169 | } | |
9ae8ffe7 | 2170 | |
1c72c7f6 JC |
2171 | if (y_base == 0) |
2172 | { | |
2173 | rtx y_c; | |
2174 | if (! flag_expensive_optimizations || (y_c = canon_rtx (y)) == y) | |
2175 | return 1; | |
d4b60170 | 2176 | |
1c72c7f6 JC |
2177 | y_base = find_base_term (y_c); |
2178 | if (y_base == 0) | |
2179 | return 1; | |
2180 | } | |
2181 | ||
2182 | /* If the base addresses are equal nothing is known about aliasing. */ | |
2183 | if (rtx_equal_p (x_base, y_base)) | |
9ae8ffe7 JL |
2184 | return 1; |
2185 | ||
435da628 UB |
2186 | /* The base addresses are different expressions. If they are not accessed |
2187 | via AND, there is no conflict. We can bring knowledge of object | |
2188 | alignment into play here. For example, on alpha, "char a, b;" can | |
5764ee3c | 2189 | alias one another, though "char a; long b;" cannot. AND addresses may |
435da628 UB |
2190 | implicitly alias surrounding objects; i.e. unaligned access in DImode |
2191 | via AND address can alias all surrounding object types except those | |
2192 | with aligment 8 or higher. */ | |
2193 | if (GET_CODE (x) == AND && GET_CODE (y) == AND) | |
2194 | return 1; | |
2195 | if (GET_CODE (x) == AND | |
481683e1 | 2196 | && (!CONST_INT_P (XEXP (x, 1)) |
435da628 UB |
2197 | || (int) GET_MODE_UNIT_SIZE (y_mode) < -INTVAL (XEXP (x, 1)))) |
2198 | return 1; | |
2199 | if (GET_CODE (y) == AND | |
481683e1 | 2200 | && (!CONST_INT_P (XEXP (y, 1)) |
435da628 UB |
2201 | || (int) GET_MODE_UNIT_SIZE (x_mode) < -INTVAL (XEXP (y, 1)))) |
2202 | return 1; | |
2203 | ||
73e48cb3 | 2204 | /* Differing symbols not accessed via AND never alias. */ |
3a28db46 | 2205 | if (GET_CODE (x_base) == SYMBOL_REF && GET_CODE (y_base) == SYMBOL_REF) |
73e48cb3 | 2206 | return compare_base_symbol_refs (x_base, y_base) != 0; |
3a28db46 | 2207 | |
9ae8ffe7 | 2208 | if (GET_CODE (x_base) != ADDRESS && GET_CODE (y_base) != ADDRESS) |
435da628 | 2209 | return 0; |
9ae8ffe7 | 2210 | |
9fc37b2b | 2211 | if (unique_base_value_p (x_base) || unique_base_value_p (y_base)) |
9ae8ffe7 JL |
2212 | return 0; |
2213 | ||
0d3c82d6 | 2214 | return 1; |
9ae8ffe7 JL |
2215 | } |
2216 | ||
a5628378 | 2217 | /* Return TRUE if EXPR refers to a VALUE whose uid is greater than |
c779924e | 2218 | (or equal to) that of V. */ |
a5628378 AO |
2219 | |
2220 | static bool | |
403837b4 | 2221 | refs_newer_value_p (const_rtx expr, rtx v) |
a5628378 AO |
2222 | { |
2223 | int minuid = CSELIB_VAL_PTR (v)->uid; | |
403837b4 RS |
2224 | subrtx_iterator::array_type array; |
2225 | FOR_EACH_SUBRTX (iter, array, expr, NONCONST) | |
c779924e | 2226 | if (GET_CODE (*iter) == VALUE && CSELIB_VAL_PTR (*iter)->uid >= minuid) |
403837b4 RS |
2227 | return true; |
2228 | return false; | |
a5628378 AO |
2229 | } |
2230 | ||
eab5c70a | 2231 | /* Convert the address X into something we can use. This is done by returning |
569efc34 JJ |
2232 | it unchanged unless it is a VALUE or VALUE +/- constant; for VALUE |
2233 | we call cselib to get a more useful rtx. */ | |
3bdf5ad1 | 2234 | |
a13d4ebf | 2235 | rtx |
4682ae04 | 2236 | get_addr (rtx x) |
eab5c70a BS |
2237 | { |
2238 | cselib_val *v; | |
2239 | struct elt_loc_list *l; | |
2240 | ||
2241 | if (GET_CODE (x) != VALUE) | |
569efc34 JJ |
2242 | { |
2243 | if ((GET_CODE (x) == PLUS || GET_CODE (x) == MINUS) | |
2244 | && GET_CODE (XEXP (x, 0)) == VALUE | |
2245 | && CONST_SCALAR_INT_P (XEXP (x, 1))) | |
2246 | { | |
2247 | rtx op0 = get_addr (XEXP (x, 0)); | |
2248 | if (op0 != XEXP (x, 0)) | |
2249 | { | |
2250 | if (GET_CODE (x) == PLUS | |
2251 | && GET_CODE (XEXP (x, 1)) == CONST_INT) | |
2252 | return plus_constant (GET_MODE (x), op0, INTVAL (XEXP (x, 1))); | |
2253 | return simplify_gen_binary (GET_CODE (x), GET_MODE (x), | |
2254 | op0, XEXP (x, 1)); | |
2255 | } | |
2256 | } | |
2257 | return x; | |
2258 | } | |
eab5c70a | 2259 | v = CSELIB_VAL_PTR (x); |
40e02b4a JH |
2260 | if (v) |
2261 | { | |
0f68ba3e AO |
2262 | bool have_equivs = cselib_have_permanent_equivalences (); |
2263 | if (have_equivs) | |
2264 | v = canonical_cselib_val (v); | |
40e02b4a JH |
2265 | for (l = v->locs; l; l = l->next) |
2266 | if (CONSTANT_P (l->loc)) | |
2267 | return l->loc; | |
2268 | for (l = v->locs; l; l = l->next) | |
0f68ba3e AO |
2269 | if (!REG_P (l->loc) && !MEM_P (l->loc) |
2270 | /* Avoid infinite recursion when potentially dealing with | |
2271 | var-tracking artificial equivalences, by skipping the | |
2272 | equivalences themselves, and not choosing expressions | |
2273 | that refer to newer VALUEs. */ | |
2274 | && (!have_equivs | |
2275 | || (GET_CODE (l->loc) != VALUE | |
2276 | && !refs_newer_value_p (l->loc, x)))) | |
a5628378 | 2277 | return l->loc; |
0f68ba3e AO |
2278 | if (have_equivs) |
2279 | { | |
2280 | for (l = v->locs; l; l = l->next) | |
2281 | if (REG_P (l->loc) | |
2282 | || (GET_CODE (l->loc) != VALUE | |
2283 | && !refs_newer_value_p (l->loc, x))) | |
2284 | return l->loc; | |
2285 | /* Return the canonical value. */ | |
2286 | return v->val_rtx; | |
2287 | } | |
2288 | if (v->locs) | |
2289 | return v->locs->loc; | |
40e02b4a | 2290 | } |
eab5c70a BS |
2291 | return x; |
2292 | } | |
2293 | ||
39cec1ac MH |
2294 | /* Return the address of the (N_REFS + 1)th memory reference to ADDR |
2295 | where SIZE is the size in bytes of the memory reference. If ADDR | |
2296 | is not modified by the memory reference then ADDR is returned. */ | |
2297 | ||
04e2b4d3 | 2298 | static rtx |
9f61be58 | 2299 | addr_side_effect_eval (rtx addr, poly_int64 size, int n_refs) |
39cec1ac | 2300 | { |
9f61be58 | 2301 | poly_int64 offset = 0; |
ca7fd9cd | 2302 | |
39cec1ac MH |
2303 | switch (GET_CODE (addr)) |
2304 | { | |
2305 | case PRE_INC: | |
2306 | offset = (n_refs + 1) * size; | |
2307 | break; | |
2308 | case PRE_DEC: | |
2309 | offset = -(n_refs + 1) * size; | |
2310 | break; | |
2311 | case POST_INC: | |
2312 | offset = n_refs * size; | |
2313 | break; | |
2314 | case POST_DEC: | |
2315 | offset = -n_refs * size; | |
2316 | break; | |
2317 | ||
2318 | default: | |
2319 | return addr; | |
2320 | } | |
ca7fd9cd | 2321 | |
9f61be58 | 2322 | addr = plus_constant (GET_MODE (addr), XEXP (addr, 0), offset); |
45183e03 | 2323 | addr = canon_rtx (addr); |
39cec1ac MH |
2324 | |
2325 | return addr; | |
2326 | } | |
2327 | ||
3aa03517 AO |
2328 | /* Return TRUE if an object X sized at XSIZE bytes and another object |
2329 | Y sized at YSIZE bytes, starting C bytes after X, may overlap. If | |
2330 | any of the sizes is zero, assume an overlap, otherwise use the | |
2331 | absolute value of the sizes as the actual sizes. */ | |
2332 | ||
2333 | static inline bool | |
d05d7551 | 2334 | offset_overlap_p (poly_int64 c, poly_int64 xsize, poly_int64 ysize) |
3aa03517 | 2335 | { |
d05d7551 RS |
2336 | if (known_eq (xsize, 0) || known_eq (ysize, 0)) |
2337 | return true; | |
2338 | ||
2339 | if (maybe_ge (c, 0)) | |
2340 | return maybe_gt (maybe_lt (xsize, 0) ? -xsize : xsize, c); | |
2341 | else | |
2342 | return maybe_gt (maybe_lt (ysize, 0) ? -ysize : ysize, -c); | |
3aa03517 AO |
2343 | } |
2344 | ||
f47e08d9 RG |
2345 | /* Return one if X and Y (memory addresses) reference the |
2346 | same location in memory or if the references overlap. | |
2347 | Return zero if they do not overlap, else return | |
2348 | minus one in which case they still might reference the same location. | |
2349 | ||
2350 | C is an offset accumulator. When | |
9ae8ffe7 JL |
2351 | C is nonzero, we are testing aliases between X and Y + C. |
2352 | XSIZE is the size in bytes of the X reference, | |
2353 | similarly YSIZE is the size in bytes for Y. | |
45183e03 | 2354 | Expect that canon_rtx has been already called for X and Y. |
9ae8ffe7 JL |
2355 | |
2356 | If XSIZE or YSIZE is zero, we do not know the amount of memory being | |
2357 | referenced (the reference was BLKmode), so make the most pessimistic | |
2358 | assumptions. | |
2359 | ||
c02f035f RH |
2360 | If XSIZE or YSIZE is negative, we may access memory outside the object |
2361 | being referenced as a side effect. This can happen when using AND to | |
2362 | align memory references, as is done on the Alpha. | |
2363 | ||
9ae8ffe7 | 2364 | Nice to notice that varying addresses cannot conflict with fp if no |
f47e08d9 RG |
2365 | local variables had their addresses taken, but that's too hard now. |
2366 | ||
2367 | ??? Contrary to the tree alias oracle this does not return | |
2368 | one for X + non-constant and Y + non-constant when X and Y are equal. | |
2369 | If that is fixed the TBAA hack for union type-punning can be removed. */ | |
9ae8ffe7 | 2370 | |
9ae8ffe7 | 2371 | static int |
9f61be58 RS |
2372 | memrefs_conflict_p (poly_int64 xsize, rtx x, poly_int64 ysize, rtx y, |
2373 | poly_int64 c) | |
9ae8ffe7 | 2374 | { |
eab5c70a | 2375 | if (GET_CODE (x) == VALUE) |
5312b066 JJ |
2376 | { |
2377 | if (REG_P (y)) | |
2378 | { | |
24f8d71e JJ |
2379 | struct elt_loc_list *l = NULL; |
2380 | if (CSELIB_VAL_PTR (x)) | |
a5628378 AO |
2381 | for (l = canonical_cselib_val (CSELIB_VAL_PTR (x))->locs; |
2382 | l; l = l->next) | |
24f8d71e JJ |
2383 | if (REG_P (l->loc) && rtx_equal_for_memref_p (l->loc, y)) |
2384 | break; | |
5312b066 JJ |
2385 | if (l) |
2386 | x = y; | |
2387 | else | |
2388 | x = get_addr (x); | |
2389 | } | |
2390 | /* Don't call get_addr if y is the same VALUE. */ | |
2391 | else if (x != y) | |
2392 | x = get_addr (x); | |
2393 | } | |
eab5c70a | 2394 | if (GET_CODE (y) == VALUE) |
5312b066 JJ |
2395 | { |
2396 | if (REG_P (x)) | |
2397 | { | |
24f8d71e JJ |
2398 | struct elt_loc_list *l = NULL; |
2399 | if (CSELIB_VAL_PTR (y)) | |
a5628378 AO |
2400 | for (l = canonical_cselib_val (CSELIB_VAL_PTR (y))->locs; |
2401 | l; l = l->next) | |
24f8d71e JJ |
2402 | if (REG_P (l->loc) && rtx_equal_for_memref_p (l->loc, x)) |
2403 | break; | |
5312b066 JJ |
2404 | if (l) |
2405 | y = x; | |
2406 | else | |
2407 | y = get_addr (y); | |
2408 | } | |
2409 | /* Don't call get_addr if x is the same VALUE. */ | |
2410 | else if (y != x) | |
2411 | y = get_addr (y); | |
2412 | } | |
9ae8ffe7 JL |
2413 | if (GET_CODE (x) == HIGH) |
2414 | x = XEXP (x, 0); | |
2415 | else if (GET_CODE (x) == LO_SUM) | |
2416 | x = XEXP (x, 1); | |
2417 | else | |
9f61be58 | 2418 | x = addr_side_effect_eval (x, maybe_lt (xsize, 0) ? -xsize : xsize, 0); |
9ae8ffe7 JL |
2419 | if (GET_CODE (y) == HIGH) |
2420 | y = XEXP (y, 0); | |
2421 | else if (GET_CODE (y) == LO_SUM) | |
2422 | y = XEXP (y, 1); | |
2423 | else | |
9f61be58 | 2424 | y = addr_side_effect_eval (y, maybe_lt (ysize, 0) ? -ysize : ysize, 0); |
9ae8ffe7 | 2425 | |
54363f8a JH |
2426 | if (GET_CODE (x) == SYMBOL_REF && GET_CODE (y) == SYMBOL_REF) |
2427 | { | |
73e48cb3 | 2428 | int cmp = compare_base_symbol_refs (x,y); |
54363f8a JH |
2429 | |
2430 | /* If both decls are the same, decide by offsets. */ | |
2431 | if (cmp == 1) | |
2432 | return offset_overlap_p (c, xsize, ysize); | |
3a28db46 UB |
2433 | /* Assume a potential overlap for symbolic addresses that went |
2434 | through alignment adjustments (i.e., that have negative | |
2435 | sizes), because we can't know how far they are from each | |
2436 | other. */ | |
9f61be58 | 2437 | if (maybe_lt (xsize, 0) || maybe_lt (ysize, 0)) |
3a28db46 | 2438 | return -1; |
54363f8a JH |
2439 | /* If decls are different or we know by offsets that there is no overlap, |
2440 | we win. */ | |
2441 | if (!cmp || !offset_overlap_p (c, xsize, ysize)) | |
2442 | return 0; | |
2443 | /* Decls may or may not be different and offsets overlap....*/ | |
2444 | return -1; | |
2445 | } | |
2446 | else if (rtx_equal_for_memref_p (x, y)) | |
9ae8ffe7 | 2447 | { |
3aa03517 | 2448 | return offset_overlap_p (c, xsize, ysize); |
9ae8ffe7 JL |
2449 | } |
2450 | ||
6e73e666 JC |
2451 | /* This code used to check for conflicts involving stack references and |
2452 | globals but the base address alias code now handles these cases. */ | |
9ae8ffe7 JL |
2453 | |
2454 | if (GET_CODE (x) == PLUS) | |
2455 | { | |
2456 | /* The fact that X is canonicalized means that this | |
2457 | PLUS rtx is canonicalized. */ | |
2458 | rtx x0 = XEXP (x, 0); | |
2459 | rtx x1 = XEXP (x, 1); | |
2460 | ||
2d88904a AO |
2461 | /* However, VALUEs might end up in different positions even in |
2462 | canonical PLUSes. Comparing their addresses is enough. */ | |
2463 | if (x0 == y) | |
2464 | return memrefs_conflict_p (xsize, x1, ysize, const0_rtx, c); | |
2465 | else if (x1 == y) | |
2466 | return memrefs_conflict_p (xsize, x0, ysize, const0_rtx, c); | |
2467 | ||
9f61be58 | 2468 | poly_int64 cx1, cy1; |
9ae8ffe7 JL |
2469 | if (GET_CODE (y) == PLUS) |
2470 | { | |
2471 | /* The fact that Y is canonicalized means that this | |
2472 | PLUS rtx is canonicalized. */ | |
2473 | rtx y0 = XEXP (y, 0); | |
2474 | rtx y1 = XEXP (y, 1); | |
2475 | ||
2d88904a AO |
2476 | if (x0 == y1) |
2477 | return memrefs_conflict_p (xsize, x1, ysize, y0, c); | |
2478 | if (x1 == y0) | |
2479 | return memrefs_conflict_p (xsize, x0, ysize, y1, c); | |
2480 | ||
9ae8ffe7 JL |
2481 | if (rtx_equal_for_memref_p (x1, y1)) |
2482 | return memrefs_conflict_p (xsize, x0, ysize, y0, c); | |
2483 | if (rtx_equal_for_memref_p (x0, y0)) | |
2484 | return memrefs_conflict_p (xsize, x1, ysize, y1, c); | |
9f61be58 | 2485 | if (poly_int_rtx_p (x1, &cx1)) |
63be02db | 2486 | { |
9f61be58 | 2487 | if (poly_int_rtx_p (y1, &cy1)) |
63be02db | 2488 | return memrefs_conflict_p (xsize, x0, ysize, y0, |
9f61be58 | 2489 | c - cx1 + cy1); |
63be02db | 2490 | else |
9f61be58 | 2491 | return memrefs_conflict_p (xsize, x0, ysize, y, c - cx1); |
63be02db | 2492 | } |
9f61be58 RS |
2493 | else if (poly_int_rtx_p (y1, &cy1)) |
2494 | return memrefs_conflict_p (xsize, x, ysize, y0, c + cy1); | |
9ae8ffe7 | 2495 | |
f47e08d9 | 2496 | return -1; |
9ae8ffe7 | 2497 | } |
9f61be58 RS |
2498 | else if (poly_int_rtx_p (x1, &cx1)) |
2499 | return memrefs_conflict_p (xsize, x0, ysize, y, c - cx1); | |
9ae8ffe7 JL |
2500 | } |
2501 | else if (GET_CODE (y) == PLUS) | |
2502 | { | |
2503 | /* The fact that Y is canonicalized means that this | |
2504 | PLUS rtx is canonicalized. */ | |
2505 | rtx y0 = XEXP (y, 0); | |
2506 | rtx y1 = XEXP (y, 1); | |
2507 | ||
2d88904a AO |
2508 | if (x == y0) |
2509 | return memrefs_conflict_p (xsize, const0_rtx, ysize, y1, c); | |
2510 | if (x == y1) | |
2511 | return memrefs_conflict_p (xsize, const0_rtx, ysize, y0, c); | |
2512 | ||
9f61be58 RS |
2513 | poly_int64 cy1; |
2514 | if (poly_int_rtx_p (y1, &cy1)) | |
2515 | return memrefs_conflict_p (xsize, x, ysize, y0, c + cy1); | |
9ae8ffe7 | 2516 | else |
f47e08d9 | 2517 | return -1; |
9ae8ffe7 JL |
2518 | } |
2519 | ||
2520 | if (GET_CODE (x) == GET_CODE (y)) | |
2521 | switch (GET_CODE (x)) | |
2522 | { | |
2523 | case MULT: | |
2524 | { | |
2525 | /* Handle cases where we expect the second operands to be the | |
2526 | same, and check only whether the first operand would conflict | |
2527 | or not. */ | |
2528 | rtx x0, y0; | |
2529 | rtx x1 = canon_rtx (XEXP (x, 1)); | |
2530 | rtx y1 = canon_rtx (XEXP (y, 1)); | |
2531 | if (! rtx_equal_for_memref_p (x1, y1)) | |
f47e08d9 | 2532 | return -1; |
9ae8ffe7 JL |
2533 | x0 = canon_rtx (XEXP (x, 0)); |
2534 | y0 = canon_rtx (XEXP (y, 0)); | |
2535 | if (rtx_equal_for_memref_p (x0, y0)) | |
3aa03517 | 2536 | return offset_overlap_p (c, xsize, ysize); |
9ae8ffe7 JL |
2537 | |
2538 | /* Can't properly adjust our sizes. */ | |
9f61be58 RS |
2539 | if (!CONST_INT_P (x1) |
2540 | || !can_div_trunc_p (xsize, INTVAL (x1), &xsize) | |
2541 | || !can_div_trunc_p (ysize, INTVAL (x1), &ysize) | |
2542 | || !can_div_trunc_p (c, INTVAL (x1), &c)) | |
f47e08d9 | 2543 | return -1; |
9ae8ffe7 JL |
2544 | return memrefs_conflict_p (xsize, x0, ysize, y0, c); |
2545 | } | |
1d300e19 KG |
2546 | |
2547 | default: | |
2548 | break; | |
9ae8ffe7 JL |
2549 | } |
2550 | ||
a9bf4fe2 AO |
2551 | /* Deal with alignment ANDs by adjusting offset and size so as to |
2552 | cover the maximum range, without taking any previously known | |
5147bf6a AO |
2553 | alignment into account. Make a size negative after such an |
2554 | adjustments, so that, if we end up with e.g. two SYMBOL_REFs, we | |
2555 | assume a potential overlap, because they may end up in contiguous | |
2556 | memory locations and the stricter-alignment access may span over | |
2557 | part of both. */ | |
481683e1 | 2558 | if (GET_CODE (x) == AND && CONST_INT_P (XEXP (x, 1))) |
56ee9281 | 2559 | { |
a9bf4fe2 AO |
2560 | HOST_WIDE_INT sc = INTVAL (XEXP (x, 1)); |
2561 | unsigned HOST_WIDE_INT uc = sc; | |
146ec50f | 2562 | if (sc < 0 && pow2_or_zerop (-uc)) |
a9bf4fe2 | 2563 | { |
9f61be58 | 2564 | if (maybe_gt (xsize, 0)) |
5147bf6a | 2565 | xsize = -xsize; |
9f61be58 | 2566 | if (maybe_ne (xsize, 0)) |
3aa03517 | 2567 | xsize += sc + 1; |
fe8fb1c4 | 2568 | c -= sc + 1; |
a9bf4fe2 AO |
2569 | return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)), |
2570 | ysize, y, c); | |
2571 | } | |
56ee9281 | 2572 | } |
481683e1 | 2573 | if (GET_CODE (y) == AND && CONST_INT_P (XEXP (y, 1))) |
c02f035f | 2574 | { |
a9bf4fe2 AO |
2575 | HOST_WIDE_INT sc = INTVAL (XEXP (y, 1)); |
2576 | unsigned HOST_WIDE_INT uc = sc; | |
146ec50f | 2577 | if (sc < 0 && pow2_or_zerop (-uc)) |
a9bf4fe2 | 2578 | { |
9f61be58 | 2579 | if (maybe_gt (ysize, 0)) |
5147bf6a | 2580 | ysize = -ysize; |
9f61be58 | 2581 | if (maybe_ne (ysize, 0)) |
3aa03517 | 2582 | ysize += sc + 1; |
fe8fb1c4 | 2583 | c += sc + 1; |
a9bf4fe2 AO |
2584 | return memrefs_conflict_p (xsize, x, |
2585 | ysize, canon_rtx (XEXP (y, 0)), c); | |
2586 | } | |
c02f035f | 2587 | } |
9ae8ffe7 JL |
2588 | |
2589 | if (CONSTANT_P (x)) | |
2590 | { | |
9f61be58 RS |
2591 | poly_int64 cx, cy; |
2592 | if (poly_int_rtx_p (x, &cx) && poly_int_rtx_p (y, &cy)) | |
9ae8ffe7 | 2593 | { |
9f61be58 | 2594 | c += cy - cx; |
3aa03517 | 2595 | return offset_overlap_p (c, xsize, ysize); |
9ae8ffe7 JL |
2596 | } |
2597 | ||
2598 | if (GET_CODE (x) == CONST) | |
2599 | { | |
2600 | if (GET_CODE (y) == CONST) | |
2601 | return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)), | |
2602 | ysize, canon_rtx (XEXP (y, 0)), c); | |
2603 | else | |
2604 | return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)), | |
2605 | ysize, y, c); | |
2606 | } | |
2607 | if (GET_CODE (y) == CONST) | |
2608 | return memrefs_conflict_p (xsize, x, ysize, | |
2609 | canon_rtx (XEXP (y, 0)), c); | |
2610 | ||
3aa03517 AO |
2611 | /* Assume a potential overlap for symbolic addresses that went |
2612 | through alignment adjustments (i.e., that have negative | |
2613 | sizes), because we can't know how far they are from each | |
2614 | other. */ | |
9ae8ffe7 | 2615 | if (CONSTANT_P (y)) |
9f61be58 RS |
2616 | return (maybe_lt (xsize, 0) |
2617 | || maybe_lt (ysize, 0) | |
2618 | || offset_overlap_p (c, xsize, ysize)); | |
9ae8ffe7 | 2619 | |
f47e08d9 | 2620 | return -1; |
9ae8ffe7 | 2621 | } |
f47e08d9 RG |
2622 | |
2623 | return -1; | |
9ae8ffe7 JL |
2624 | } |
2625 | ||
2626 | /* Functions to compute memory dependencies. | |
2627 | ||
2628 | Since we process the insns in execution order, we can build tables | |
2629 | to keep track of what registers are fixed (and not aliased), what registers | |
2630 | are varying in known ways, and what registers are varying in unknown | |
2631 | ways. | |
2632 | ||
2633 | If both memory references are volatile, then there must always be a | |
2634 | dependence between the two references, since their order can not be | |
2635 | changed. A volatile and non-volatile reference can be interchanged | |
ca7fd9cd | 2636 | though. |
9ae8ffe7 | 2637 | |
53d9622b RS |
2638 | We also must allow AND addresses, because they may generate accesses |
2639 | outside the object being referenced. This is used to generate aligned | |
2640 | addresses from unaligned addresses, for instance, the alpha | |
dc1618bc | 2641 | storeqi_unaligned pattern. */ |
9ae8ffe7 JL |
2642 | |
2643 | /* Read dependence: X is read after read in MEM takes place. There can | |
96672a3e RH |
2644 | only be a dependence here if both reads are volatile, or if either is |
2645 | an explicit barrier. */ | |
9ae8ffe7 JL |
2646 | |
2647 | int | |
4f588890 | 2648 | read_dependence (const_rtx mem, const_rtx x) |
9ae8ffe7 | 2649 | { |
96672a3e RH |
2650 | if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) |
2651 | return true; | |
2652 | if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER | |
2653 | || MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER) | |
2654 | return true; | |
2655 | return false; | |
9ae8ffe7 JL |
2656 | } |
2657 | ||
998d7deb RH |
2658 | /* Look at the bottom of the COMPONENT_REF list for a DECL, and return it. */ |
2659 | ||
2660 | static tree | |
4682ae04 | 2661 | decl_for_component_ref (tree x) |
998d7deb RH |
2662 | { |
2663 | do | |
2664 | { | |
2665 | x = TREE_OPERAND (x, 0); | |
2666 | } | |
2667 | while (x && TREE_CODE (x) == COMPONENT_REF); | |
2668 | ||
2669 | return x && DECL_P (x) ? x : NULL_TREE; | |
2670 | } | |
2671 | ||
527210c4 RS |
2672 | /* Walk up the COMPONENT_REF list in X and adjust *OFFSET to compensate |
2673 | for the offset of the field reference. *KNOWN_P says whether the | |
2674 | offset is known. */ | |
998d7deb | 2675 | |
527210c4 RS |
2676 | static void |
2677 | adjust_offset_for_component_ref (tree x, bool *known_p, | |
d05d7551 | 2678 | poly_int64 *offset) |
998d7deb | 2679 | { |
527210c4 RS |
2680 | if (!*known_p) |
2681 | return; | |
ca7fd9cd | 2682 | do |
998d7deb | 2683 | { |
527210c4 | 2684 | tree xoffset = component_ref_field_offset (x); |
998d7deb | 2685 | tree field = TREE_OPERAND (x, 1); |
807e902e KZ |
2686 | if (TREE_CODE (xoffset) != INTEGER_CST) |
2687 | { | |
2688 | *known_p = false; | |
2689 | return; | |
2690 | } | |
998d7deb | 2691 | |
807e902e KZ |
2692 | offset_int woffset |
2693 | = (wi::to_offset (xoffset) | |
8de73453 RS |
2694 | + (wi::to_offset (DECL_FIELD_BIT_OFFSET (field)) |
2695 | >> LOG2_BITS_PER_UNIT)); | |
807e902e | 2696 | if (!wi::fits_uhwi_p (woffset)) |
527210c4 RS |
2697 | { |
2698 | *known_p = false; | |
2699 | return; | |
2700 | } | |
807e902e | 2701 | *offset += woffset.to_uhwi (); |
998d7deb RH |
2702 | |
2703 | x = TREE_OPERAND (x, 0); | |
2704 | } | |
2705 | while (x && TREE_CODE (x) == COMPONENT_REF); | |
998d7deb RH |
2706 | } |
2707 | ||
95bd1dd7 | 2708 | /* Return nonzero if we can determine the exprs corresponding to memrefs |
c6ea834c BM |
2709 | X and Y and they do not overlap. |
2710 | If LOOP_VARIANT is set, skip offset-based disambiguation */ | |
a4311dfe | 2711 | |
2e4e39f6 | 2712 | int |
c6ea834c | 2713 | nonoverlapping_memrefs_p (const_rtx x, const_rtx y, bool loop_invariant) |
a4311dfe | 2714 | { |
998d7deb | 2715 | tree exprx = MEM_EXPR (x), expry = MEM_EXPR (y); |
a4311dfe RK |
2716 | rtx rtlx, rtly; |
2717 | rtx basex, basey; | |
527210c4 | 2718 | bool moffsetx_known_p, moffsety_known_p; |
d05d7551 RS |
2719 | poly_int64 moffsetx = 0, moffsety = 0; |
2720 | poly_int64 offsetx = 0, offsety = 0, sizex, sizey; | |
a4311dfe | 2721 | |
998d7deb RH |
2722 | /* Unless both have exprs, we can't tell anything. */ |
2723 | if (exprx == 0 || expry == 0) | |
2724 | return 0; | |
2b22e382 RG |
2725 | |
2726 | /* For spill-slot accesses make sure we have valid offsets. */ | |
2727 | if ((exprx == get_spill_slot_decl (false) | |
527210c4 | 2728 | && ! MEM_OFFSET_KNOWN_P (x)) |
2b22e382 | 2729 | || (expry == get_spill_slot_decl (false) |
527210c4 | 2730 | && ! MEM_OFFSET_KNOWN_P (y))) |
2b22e382 | 2731 | return 0; |
c22cacf3 | 2732 | |
998d7deb | 2733 | /* If the field reference test failed, look at the DECLs involved. */ |
527210c4 RS |
2734 | moffsetx_known_p = MEM_OFFSET_KNOWN_P (x); |
2735 | if (moffsetx_known_p) | |
2736 | moffsetx = MEM_OFFSET (x); | |
998d7deb RH |
2737 | if (TREE_CODE (exprx) == COMPONENT_REF) |
2738 | { | |
2e0c984c RG |
2739 | tree t = decl_for_component_ref (exprx); |
2740 | if (! t) | |
2741 | return 0; | |
527210c4 | 2742 | adjust_offset_for_component_ref (exprx, &moffsetx_known_p, &moffsetx); |
2e0c984c | 2743 | exprx = t; |
998d7deb | 2744 | } |
c67a1cf6 | 2745 | |
527210c4 RS |
2746 | moffsety_known_p = MEM_OFFSET_KNOWN_P (y); |
2747 | if (moffsety_known_p) | |
2748 | moffsety = MEM_OFFSET (y); | |
998d7deb RH |
2749 | if (TREE_CODE (expry) == COMPONENT_REF) |
2750 | { | |
2e0c984c RG |
2751 | tree t = decl_for_component_ref (expry); |
2752 | if (! t) | |
2753 | return 0; | |
527210c4 | 2754 | adjust_offset_for_component_ref (expry, &moffsety_known_p, &moffsety); |
2e0c984c | 2755 | expry = t; |
998d7deb RH |
2756 | } |
2757 | ||
2758 | if (! DECL_P (exprx) || ! DECL_P (expry)) | |
a4311dfe RK |
2759 | return 0; |
2760 | ||
1f9ceff1 AO |
2761 | /* If we refer to different gimple registers, or one gimple register |
2762 | and one non-gimple-register, we know they can't overlap. First, | |
2763 | gimple registers don't have their addresses taken. Now, there | |
2764 | could be more than one stack slot for (different versions of) the | |
2765 | same gimple register, but we can presumably tell they don't | |
2766 | overlap based on offsets from stack base addresses elsewhere. | |
2767 | It's important that we don't proceed to DECL_RTL, because gimple | |
2768 | registers may not pass DECL_RTL_SET_P, and make_decl_rtl won't be | |
2769 | able to do anything about them since no SSA information will have | |
2770 | remained to guide it. */ | |
2771 | if (is_gimple_reg (exprx) || is_gimple_reg (expry)) | |
2d88904a AO |
2772 | return exprx != expry |
2773 | || (moffsetx_known_p && moffsety_known_p | |
2774 | && MEM_SIZE_KNOWN_P (x) && MEM_SIZE_KNOWN_P (y) | |
2775 | && !offset_overlap_p (moffsety - moffsetx, | |
2776 | MEM_SIZE (x), MEM_SIZE (y))); | |
1f9ceff1 | 2777 | |
1307c758 RG |
2778 | /* With invalid code we can end up storing into the constant pool. |
2779 | Bail out to avoid ICEing when creating RTL for this. | |
2780 | See gfortran.dg/lto/20091028-2_0.f90. */ | |
2781 | if (TREE_CODE (exprx) == CONST_DECL | |
2782 | || TREE_CODE (expry) == CONST_DECL) | |
2783 | return 1; | |
2784 | ||
dca16798 JJ |
2785 | /* If one decl is known to be a function or label in a function and |
2786 | the other is some kind of data, they can't overlap. */ | |
2787 | if ((TREE_CODE (exprx) == FUNCTION_DECL | |
2788 | || TREE_CODE (exprx) == LABEL_DECL) | |
2789 | != (TREE_CODE (expry) == FUNCTION_DECL | |
2790 | || TREE_CODE (expry) == LABEL_DECL)) | |
2791 | return 1; | |
2792 | ||
5f4cebba JJ |
2793 | /* If either of the decls doesn't have DECL_RTL set (e.g. marked as |
2794 | living in multiple places), we can't tell anything. Exception | |
2795 | are FUNCTION_DECLs for which we can create DECL_RTL on demand. */ | |
2796 | if ((!DECL_RTL_SET_P (exprx) && TREE_CODE (exprx) != FUNCTION_DECL) | |
2797 | || (!DECL_RTL_SET_P (expry) && TREE_CODE (expry) != FUNCTION_DECL)) | |
2798 | return 0; | |
2799 | ||
998d7deb RH |
2800 | rtlx = DECL_RTL (exprx); |
2801 | rtly = DECL_RTL (expry); | |
a4311dfe | 2802 | |
1edcd60b RK |
2803 | /* If either RTL is not a MEM, it must be a REG or CONCAT, meaning they |
2804 | can't overlap unless they are the same because we never reuse that part | |
2805 | of the stack frame used for locals for spilled pseudos. */ | |
3c0cb5de | 2806 | if ((!MEM_P (rtlx) || !MEM_P (rtly)) |
1edcd60b | 2807 | && ! rtx_equal_p (rtlx, rtly)) |
a4311dfe RK |
2808 | return 1; |
2809 | ||
5932a4d4 | 2810 | /* If we have MEMs referring to different address spaces (which can |
09e881c9 BE |
2811 | potentially overlap), we cannot easily tell from the addresses |
2812 | whether the references overlap. */ | |
2813 | if (MEM_P (rtlx) && MEM_P (rtly) | |
2814 | && MEM_ADDR_SPACE (rtlx) != MEM_ADDR_SPACE (rtly)) | |
2815 | return 0; | |
2816 | ||
a4311dfe RK |
2817 | /* Get the base and offsets of both decls. If either is a register, we |
2818 | know both are and are the same, so use that as the base. The only | |
2819 | we can avoid overlap is if we can deduce that they are nonoverlapping | |
2820 | pieces of that decl, which is very rare. */ | |
3c0cb5de | 2821 | basex = MEM_P (rtlx) ? XEXP (rtlx, 0) : rtlx; |
d05d7551 | 2822 | basex = strip_offset_and_add (basex, &offsetx); |
a4311dfe | 2823 | |
3c0cb5de | 2824 | basey = MEM_P (rtly) ? XEXP (rtly, 0) : rtly; |
d05d7551 | 2825 | basey = strip_offset_and_add (basey, &offsety); |
a4311dfe | 2826 | |
d746694a | 2827 | /* If the bases are different, we know they do not overlap if both |
ca7fd9cd | 2828 | are constants or if one is a constant and the other a pointer into the |
d746694a RK |
2829 | stack frame. Otherwise a different base means we can't tell if they |
2830 | overlap or not. */ | |
54363f8a | 2831 | if (compare_base_decls (exprx, expry) == 0) |
ca7fd9cd KH |
2832 | return ((CONSTANT_P (basex) && CONSTANT_P (basey)) |
2833 | || (CONSTANT_P (basex) && REG_P (basey) | |
2834 | && REGNO_PTR_FRAME_P (REGNO (basey))) | |
2835 | || (CONSTANT_P (basey) && REG_P (basex) | |
2836 | && REGNO_PTR_FRAME_P (REGNO (basex)))); | |
a4311dfe | 2837 | |
c6ea834c BM |
2838 | /* Offset based disambiguation not appropriate for loop invariant */ |
2839 | if (loop_invariant) | |
dca16798 | 2840 | return 0; |
c6ea834c | 2841 | |
54363f8a JH |
2842 | /* Offset based disambiguation is OK even if we do not know that the |
2843 | declarations are necessarily different | |
2844 | (i.e. compare_base_decls (exprx, expry) == -1) */ | |
2845 | ||
d05d7551 | 2846 | sizex = (!MEM_P (rtlx) ? poly_int64 (GET_MODE_SIZE (GET_MODE (rtlx))) |
f5541398 | 2847 | : MEM_SIZE_KNOWN_P (rtlx) ? MEM_SIZE (rtlx) |
a4311dfe | 2848 | : -1); |
d05d7551 | 2849 | sizey = (!MEM_P (rtly) ? poly_int64 (GET_MODE_SIZE (GET_MODE (rtly))) |
f5541398 RS |
2850 | : MEM_SIZE_KNOWN_P (rtly) ? MEM_SIZE (rtly) |
2851 | : -1); | |
a4311dfe | 2852 | |
0af5bc3e RK |
2853 | /* If we have an offset for either memref, it can update the values computed |
2854 | above. */ | |
527210c4 RS |
2855 | if (moffsetx_known_p) |
2856 | offsetx += moffsetx, sizex -= moffsetx; | |
2857 | if (moffsety_known_p) | |
2858 | offsety += moffsety, sizey -= moffsety; | |
a4311dfe | 2859 | |
0af5bc3e | 2860 | /* If a memref has both a size and an offset, we can use the smaller size. |
efc981bb | 2861 | We can't do this if the offset isn't known because we must view this |
0af5bc3e | 2862 | memref as being anywhere inside the DECL's MEM. */ |
527210c4 | 2863 | if (MEM_SIZE_KNOWN_P (x) && moffsetx_known_p) |
f5541398 | 2864 | sizex = MEM_SIZE (x); |
527210c4 | 2865 | if (MEM_SIZE_KNOWN_P (y) && moffsety_known_p) |
f5541398 | 2866 | sizey = MEM_SIZE (y); |
a4311dfe | 2867 | |
d05d7551 | 2868 | return !ranges_maybe_overlap_p (offsetx, sizex, offsety, sizey); |
a4311dfe RK |
2869 | } |
2870 | ||
9362286d SB |
2871 | /* Helper for true_dependence and canon_true_dependence. |
2872 | Checks for true dependence: X is read after store in MEM takes place. | |
9ae8ffe7 | 2873 | |
9362286d SB |
2874 | If MEM_CANONICALIZED is FALSE, then X_ADDR and MEM_ADDR should be |
2875 | NULL_RTX, and the canonical addresses of MEM and X are both computed | |
2876 | here. If MEM_CANONICALIZED, then MEM must be already canonicalized. | |
2877 | ||
2878 | If X_ADDR is non-NULL, it is used in preference of XEXP (x, 0). | |
2879 | ||
2880 | Returns 1 if there is a true dependence, 0 otherwise. */ | |
2881 | ||
2882 | static int | |
ef4bddc2 | 2883 | true_dependence_1 (const_rtx mem, machine_mode mem_mode, rtx mem_addr, |
53d9622b | 2884 | const_rtx x, rtx x_addr, bool mem_canonicalized) |
9ae8ffe7 | 2885 | { |
0777fc02 | 2886 | rtx true_mem_addr; |
49982682 | 2887 | rtx base; |
f47e08d9 | 2888 | int ret; |
9ae8ffe7 | 2889 | |
9362286d SB |
2890 | gcc_checking_assert (mem_canonicalized ? (mem_addr != NULL_RTX) |
2891 | : (mem_addr == NULL_RTX && x_addr == NULL_RTX)); | |
2892 | ||
9ae8ffe7 JL |
2893 | if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) |
2894 | return 1; | |
2895 | ||
c4484b8f | 2896 | /* (mem:BLK (scratch)) is a special mechanism to conflict with everything. |
ac3768f6 | 2897 | This is used in epilogue deallocation functions, and in cselib. */ |
c4484b8f RH |
2898 | if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH) |
2899 | return 1; | |
2900 | if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH) | |
2901 | return 1; | |
9cd9e512 RH |
2902 | if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER |
2903 | || MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER) | |
2904 | return 1; | |
c4484b8f | 2905 | |
0777fc02 UB |
2906 | if (! x_addr) |
2907 | x_addr = XEXP (x, 0); | |
2908 | x_addr = get_addr (x_addr); | |
2909 | ||
9362286d SB |
2910 | if (! mem_addr) |
2911 | { | |
2912 | mem_addr = XEXP (mem, 0); | |
2913 | if (mem_mode == VOIDmode) | |
2914 | mem_mode = GET_MODE (mem); | |
2915 | } | |
0777fc02 | 2916 | true_mem_addr = get_addr (mem_addr); |
eab5c70a | 2917 | |
878f5596 UB |
2918 | /* Read-only memory is by definition never modified, and therefore can't |
2919 | conflict with anything. However, don't assume anything when AND | |
2920 | addresses are involved and leave to the code below to determine | |
2921 | dependence. We don't expect to find read-only set on MEM, but | |
2922 | stupid user tricks can produce them, so don't die. */ | |
2923 | if (MEM_READONLY_P (x) | |
2924 | && GET_CODE (x_addr) != AND | |
0777fc02 | 2925 | && GET_CODE (true_mem_addr) != AND) |
878f5596 UB |
2926 | return 0; |
2927 | ||
2928 | /* If we have MEMs referring to different address spaces (which can | |
2929 | potentially overlap), we cannot easily tell from the addresses | |
2930 | whether the references overlap. */ | |
2931 | if (MEM_ADDR_SPACE (mem) != MEM_ADDR_SPACE (x)) | |
2932 | return 1; | |
2933 | ||
55efb413 JW |
2934 | base = find_base_term (x_addr); |
2935 | if (base && (GET_CODE (base) == LABEL_REF | |
2936 | || (GET_CODE (base) == SYMBOL_REF | |
2937 | && CONSTANT_POOL_ADDRESS_P (base)))) | |
2938 | return 0; | |
2939 | ||
0777fc02 UB |
2940 | rtx mem_base = find_base_term (true_mem_addr); |
2941 | if (! base_alias_check (x_addr, base, true_mem_addr, mem_base, | |
31b0a960 | 2942 | GET_MODE (x), mem_mode)) |
1c72c7f6 JC |
2943 | return 0; |
2944 | ||
eab5c70a | 2945 | x_addr = canon_rtx (x_addr); |
9362286d | 2946 | if (!mem_canonicalized) |
0777fc02 | 2947 | mem_addr = canon_rtx (true_mem_addr); |
6e73e666 | 2948 | |
f47e08d9 RG |
2949 | if ((ret = memrefs_conflict_p (GET_MODE_SIZE (mem_mode), mem_addr, |
2950 | SIZE_FOR_MODE (x), x_addr, 0)) != -1) | |
2951 | return ret; | |
2952 | ||
a95b3cc7 | 2953 | if (mems_in_disjoint_alias_sets_p (x, mem)) |
f47e08d9 RG |
2954 | return 0; |
2955 | ||
c6ea834c | 2956 | if (nonoverlapping_memrefs_p (mem, x, false)) |
0211b6ab | 2957 | return 0; |
175a7536 | 2958 | |
55b34b5f | 2959 | return rtx_refs_may_alias_p (x, mem, true); |
a13d4ebf AM |
2960 | } |
2961 | ||
9362286d SB |
2962 | /* True dependence: X is read after store in MEM takes place. */ |
2963 | ||
2964 | int | |
ef4bddc2 | 2965 | true_dependence (const_rtx mem, machine_mode mem_mode, const_rtx x) |
9362286d SB |
2966 | { |
2967 | return true_dependence_1 (mem, mem_mode, NULL_RTX, | |
53d9622b | 2968 | x, NULL_RTX, /*mem_canonicalized=*/false); |
9362286d SB |
2969 | } |
2970 | ||
a13d4ebf | 2971 | /* Canonical true dependence: X is read after store in MEM takes place. |
ca7fd9cd KH |
2972 | Variant of true_dependence which assumes MEM has already been |
2973 | canonicalized (hence we no longer do that here). | |
9362286d SB |
2974 | The mem_addr argument has been added, since true_dependence_1 computed |
2975 | this value prior to canonicalizing. */ | |
a13d4ebf AM |
2976 | |
2977 | int | |
ef4bddc2 | 2978 | canon_true_dependence (const_rtx mem, machine_mode mem_mode, rtx mem_addr, |
53d9622b | 2979 | const_rtx x, rtx x_addr) |
a13d4ebf | 2980 | { |
9362286d | 2981 | return true_dependence_1 (mem, mem_mode, mem_addr, |
53d9622b | 2982 | x, x_addr, /*mem_canonicalized=*/true); |
9ae8ffe7 JL |
2983 | } |
2984 | ||
da7d8304 | 2985 | /* Returns nonzero if a write to X might alias a previous read from |
393f9fed | 2986 | (or, if WRITEP is true, a write to) MEM. |
bd280792 JR |
2987 | If X_CANONCALIZED is true, then X_ADDR is the canonicalized address of X, |
2988 | and X_MODE the mode for that access. | |
2989 | If MEM_CANONICALIZED is true, MEM is canonicalized. */ | |
9ae8ffe7 | 2990 | |
2c72b78f | 2991 | static int |
bd280792 | 2992 | write_dependence_p (const_rtx mem, |
ef4bddc2 | 2993 | const_rtx x, machine_mode x_mode, rtx x_addr, |
bd280792 | 2994 | bool mem_canonicalized, bool x_canonicalized, bool writep) |
9ae8ffe7 | 2995 | { |
bd280792 | 2996 | rtx mem_addr; |
0777fc02 | 2997 | rtx true_mem_addr, true_x_addr; |
49982682 | 2998 | rtx base; |
f47e08d9 | 2999 | int ret; |
6e73e666 | 3000 | |
bd280792 | 3001 | gcc_checking_assert (x_canonicalized |
6f5799be JJ |
3002 | ? (x_addr != NULL_RTX |
3003 | && (x_mode != VOIDmode || GET_MODE (x) == VOIDmode)) | |
bd280792 | 3004 | : (x_addr == NULL_RTX && x_mode == VOIDmode)); |
393f9fed | 3005 | |
9ae8ffe7 JL |
3006 | if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) |
3007 | return 1; | |
3008 | ||
c4484b8f RH |
3009 | /* (mem:BLK (scratch)) is a special mechanism to conflict with everything. |
3010 | This is used in epilogue deallocation functions. */ | |
3011 | if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH) | |
3012 | return 1; | |
3013 | if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH) | |
3014 | return 1; | |
9cd9e512 RH |
3015 | if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER |
3016 | || MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER) | |
3017 | return 1; | |
c4484b8f | 3018 | |
bd280792 | 3019 | if (!x_addr) |
0777fc02 UB |
3020 | x_addr = XEXP (x, 0); |
3021 | true_x_addr = get_addr (x_addr); | |
3022 | ||
3023 | mem_addr = XEXP (mem, 0); | |
3024 | true_mem_addr = get_addr (mem_addr); | |
55efb413 | 3025 | |
878f5596 UB |
3026 | /* A read from read-only memory can't conflict with read-write memory. |
3027 | Don't assume anything when AND addresses are involved and leave to | |
3028 | the code below to determine dependence. */ | |
3029 | if (!writep | |
3030 | && MEM_READONLY_P (mem) | |
0777fc02 UB |
3031 | && GET_CODE (true_x_addr) != AND |
3032 | && GET_CODE (true_mem_addr) != AND) | |
878f5596 UB |
3033 | return 0; |
3034 | ||
3035 | /* If we have MEMs referring to different address spaces (which can | |
3036 | potentially overlap), we cannot easily tell from the addresses | |
3037 | whether the references overlap. */ | |
3038 | if (MEM_ADDR_SPACE (mem) != MEM_ADDR_SPACE (x)) | |
3039 | return 1; | |
3040 | ||
0777fc02 | 3041 | base = find_base_term (true_mem_addr); |
31b0a960 RB |
3042 | if (! writep |
3043 | && base | |
3044 | && (GET_CODE (base) == LABEL_REF | |
3045 | || (GET_CODE (base) == SYMBOL_REF | |
3046 | && CONSTANT_POOL_ADDRESS_P (base)))) | |
3047 | return 0; | |
49982682 | 3048 | |
0777fc02 UB |
3049 | rtx x_base = find_base_term (true_x_addr); |
3050 | if (! base_alias_check (true_x_addr, x_base, true_mem_addr, base, | |
3051 | GET_MODE (x), GET_MODE (mem))) | |
41472af8 MM |
3052 | return 0; |
3053 | ||
bd280792 | 3054 | if (!x_canonicalized) |
393f9fed | 3055 | { |
0777fc02 | 3056 | x_addr = canon_rtx (true_x_addr); |
bd280792 | 3057 | x_mode = GET_MODE (x); |
393f9fed | 3058 | } |
bd280792 | 3059 | if (!mem_canonicalized) |
0777fc02 | 3060 | mem_addr = canon_rtx (true_mem_addr); |
6e73e666 | 3061 | |
bd280792 JR |
3062 | if ((ret = memrefs_conflict_p (SIZE_FOR_MODE (mem), mem_addr, |
3063 | GET_MODE_SIZE (x_mode), x_addr, 0)) != -1) | |
f47e08d9 RG |
3064 | return ret; |
3065 | ||
c6ea834c | 3066 | if (nonoverlapping_memrefs_p (x, mem, false)) |
c6df88cb MM |
3067 | return 0; |
3068 | ||
55b34b5f | 3069 | return rtx_refs_may_alias_p (x, mem, false); |
c6df88cb MM |
3070 | } |
3071 | ||
3072 | /* Anti dependence: X is written after read in MEM takes place. */ | |
3073 | ||
3074 | int | |
4f588890 | 3075 | anti_dependence (const_rtx mem, const_rtx x) |
c6df88cb | 3076 | { |
bd280792 JR |
3077 | return write_dependence_p (mem, x, VOIDmode, NULL_RTX, |
3078 | /*mem_canonicalized=*/false, | |
3079 | /*x_canonicalized*/false, /*writep=*/false); | |
393f9fed JR |
3080 | } |
3081 | ||
bd280792 JR |
3082 | /* Likewise, but we already have a canonicalized MEM, and X_ADDR for X. |
3083 | Also, consider X in X_MODE (which might be from an enclosing | |
3084 | STRICT_LOW_PART / ZERO_EXTRACT). | |
3085 | If MEM_CANONICALIZED is true, MEM is canonicalized. */ | |
393f9fed JR |
3086 | |
3087 | int | |
bd280792 | 3088 | canon_anti_dependence (const_rtx mem, bool mem_canonicalized, |
ef4bddc2 | 3089 | const_rtx x, machine_mode x_mode, rtx x_addr) |
393f9fed | 3090 | { |
bd280792 JR |
3091 | return write_dependence_p (mem, x, x_mode, x_addr, |
3092 | mem_canonicalized, /*x_canonicalized=*/true, | |
3093 | /*writep=*/false); | |
9ae8ffe7 JL |
3094 | } |
3095 | ||
3096 | /* Output dependence: X is written after store in MEM takes place. */ | |
3097 | ||
3098 | int | |
4f588890 | 3099 | output_dependence (const_rtx mem, const_rtx x) |
9ae8ffe7 | 3100 | { |
bd280792 JR |
3101 | return write_dependence_p (mem, x, VOIDmode, NULL_RTX, |
3102 | /*mem_canonicalized=*/false, | |
3103 | /*x_canonicalized*/false, /*writep=*/true); | |
9ae8ffe7 | 3104 | } |
43b9f499 RB |
3105 | |
3106 | /* Likewise, but we already have a canonicalized MEM, and X_ADDR for X. | |
3107 | Also, consider X in X_MODE (which might be from an enclosing | |
3108 | STRICT_LOW_PART / ZERO_EXTRACT). | |
3109 | If MEM_CANONICALIZED is true, MEM is canonicalized. */ | |
3110 | ||
3111 | int | |
3112 | canon_output_dependence (const_rtx mem, bool mem_canonicalized, | |
3113 | const_rtx x, machine_mode x_mode, rtx x_addr) | |
3114 | { | |
3115 | return write_dependence_p (mem, x, x_mode, x_addr, | |
3116 | mem_canonicalized, /*x_canonicalized=*/true, | |
3117 | /*writep=*/true); | |
3118 | } | |
c14b9960 | 3119 | \f |
6e73e666 | 3120 | |
c6ea834c BM |
3121 | |
3122 | /* Check whether X may be aliased with MEM. Don't do offset-based | |
3123 | memory disambiguation & TBAA. */ | |
3124 | int | |
3125 | may_alias_p (const_rtx mem, const_rtx x) | |
3126 | { | |
3127 | rtx x_addr, mem_addr; | |
c6ea834c BM |
3128 | |
3129 | if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) | |
3130 | return 1; | |
3131 | ||
a95b3cc7 RG |
3132 | /* (mem:BLK (scratch)) is a special mechanism to conflict with everything. |
3133 | This is used in epilogue deallocation functions. */ | |
3134 | if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH) | |
3135 | return 1; | |
3136 | if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH) | |
c6ea834c | 3137 | return 1; |
c6ea834c BM |
3138 | if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER |
3139 | || MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER) | |
3140 | return 1; | |
3141 | ||
c6ea834c | 3142 | x_addr = XEXP (x, 0); |
0777fc02 UB |
3143 | x_addr = get_addr (x_addr); |
3144 | ||
c6ea834c | 3145 | mem_addr = XEXP (mem, 0); |
0777fc02 | 3146 | mem_addr = get_addr (mem_addr); |
c6ea834c | 3147 | |
878f5596 UB |
3148 | /* Read-only memory is by definition never modified, and therefore can't |
3149 | conflict with anything. However, don't assume anything when AND | |
3150 | addresses are involved and leave to the code below to determine | |
3151 | dependence. We don't expect to find read-only set on MEM, but | |
3152 | stupid user tricks can produce them, so don't die. */ | |
3153 | if (MEM_READONLY_P (x) | |
3154 | && GET_CODE (x_addr) != AND | |
3155 | && GET_CODE (mem_addr) != AND) | |
3156 | return 0; | |
3157 | ||
3158 | /* If we have MEMs referring to different address spaces (which can | |
3159 | potentially overlap), we cannot easily tell from the addresses | |
3160 | whether the references overlap. */ | |
3161 | if (MEM_ADDR_SPACE (mem) != MEM_ADDR_SPACE (x)) | |
3162 | return 1; | |
3163 | ||
31b0a960 RB |
3164 | rtx x_base = find_base_term (x_addr); |
3165 | rtx mem_base = find_base_term (mem_addr); | |
3166 | if (! base_alias_check (x_addr, x_base, mem_addr, mem_base, | |
3167 | GET_MODE (x), GET_MODE (mem_addr))) | |
c6ea834c BM |
3168 | return 0; |
3169 | ||
c6ea834c BM |
3170 | if (nonoverlapping_memrefs_p (mem, x, true)) |
3171 | return 0; | |
3172 | ||
c6ea834c BM |
3173 | /* TBAA not valid for loop_invarint */ |
3174 | return rtx_refs_may_alias_p (x, mem, false); | |
3175 | } | |
3176 | ||
6e73e666 | 3177 | void |
b5deb7b6 | 3178 | init_alias_target (void) |
6e73e666 | 3179 | { |
b3694847 | 3180 | int i; |
6e73e666 | 3181 | |
9fc37b2b RS |
3182 | if (!arg_base_value) |
3183 | arg_base_value = gen_rtx_ADDRESS (VOIDmode, 0); | |
3184 | ||
b5deb7b6 SL |
3185 | memset (static_reg_base_value, 0, sizeof static_reg_base_value); |
3186 | ||
6e73e666 JC |
3187 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) |
3188 | /* Check whether this register can hold an incoming pointer | |
3189 | argument. FUNCTION_ARG_REGNO_P tests outgoing register | |
ec5c56db | 3190 | numbers, so translate if necessary due to register windows. */ |
6e73e666 | 3191 | if (FUNCTION_ARG_REGNO_P (OUTGOING_REGNO (i)) |
f939c3e6 | 3192 | && targetm.hard_regno_mode_ok (i, Pmode)) |
9fc37b2b RS |
3193 | static_reg_base_value[i] = arg_base_value; |
3194 | ||
e6eacdc9 RS |
3195 | /* RTL code is required to be consistent about whether it uses the |
3196 | stack pointer, the frame pointer or the argument pointer to | |
3197 | access a given area of the frame. We can therefore use the | |
3198 | base address to distinguish between the different areas. */ | |
757e8ba2 JJ |
3199 | static_reg_base_value[STACK_POINTER_REGNUM] |
3200 | = unique_base_value (UNIQUE_BASE_VALUE_SP); | |
3201 | static_reg_base_value[ARG_POINTER_REGNUM] | |
3202 | = unique_base_value (UNIQUE_BASE_VALUE_ARGP); | |
3203 | static_reg_base_value[FRAME_POINTER_REGNUM] | |
3204 | = unique_base_value (UNIQUE_BASE_VALUE_FP); | |
e6eacdc9 RS |
3205 | |
3206 | /* The above rules extend post-reload, with eliminations applying | |
3207 | consistently to each of the three pointers. Cope with cases in | |
3208 | which the frame pointer is eliminated to the hard frame pointer | |
3209 | rather than the stack pointer. */ | |
c3e08036 TS |
3210 | if (!HARD_FRAME_POINTER_IS_FRAME_POINTER) |
3211 | static_reg_base_value[HARD_FRAME_POINTER_REGNUM] | |
3212 | = unique_base_value (UNIQUE_BASE_VALUE_HFP); | |
bf1660a6 JL |
3213 | } |
3214 | ||
7b52eede JH |
3215 | /* Set MEMORY_MODIFIED when X modifies DATA (that is assumed |
3216 | to be memory reference. */ | |
3217 | static bool memory_modified; | |
3218 | static void | |
aa317c97 | 3219 | memory_modified_1 (rtx x, const_rtx pat ATTRIBUTE_UNUSED, void *data) |
7b52eede | 3220 | { |
3c0cb5de | 3221 | if (MEM_P (x)) |
7b52eede | 3222 | { |
9678086d | 3223 | if (anti_dependence (x, (const_rtx)data) || output_dependence (x, (const_rtx)data)) |
7b52eede JH |
3224 | memory_modified = true; |
3225 | } | |
3226 | } | |
3227 | ||
3228 | ||
3229 | /* Return true when INSN possibly modify memory contents of MEM | |
454ff5cb | 3230 | (i.e. address can be modified). */ |
7b52eede | 3231 | bool |
9678086d | 3232 | memory_modified_in_insn_p (const_rtx mem, const_rtx insn) |
7b52eede JH |
3233 | { |
3234 | if (!INSN_P (insn)) | |
3235 | return false; | |
bc36c711 JJ |
3236 | /* Conservatively assume all non-readonly MEMs might be modified in |
3237 | calls. */ | |
3238 | if (CALL_P (insn)) | |
3239 | return true; | |
7b52eede | 3240 | memory_modified = false; |
aa317c97 | 3241 | note_stores (PATTERN (insn), memory_modified_1, CONST_CAST_RTX(mem)); |
7b52eede JH |
3242 | return memory_modified; |
3243 | } | |
3244 | ||
a7b159a4 AH |
3245 | /* Return TRUE if the destination of a set is rtx identical to |
3246 | ITEM. */ | |
3247 | static inline bool | |
3248 | set_dest_equal_p (const_rtx set, const_rtx item) | |
3249 | { | |
3250 | rtx dest = SET_DEST (set); | |
3251 | return rtx_equal_p (dest, item); | |
3252 | } | |
3253 | ||
c13e8210 MM |
3254 | /* Initialize the aliasing machinery. Initialize the REG_KNOWN_VALUE |
3255 | array. */ | |
3256 | ||
9ae8ffe7 | 3257 | void |
4682ae04 | 3258 | init_alias_analysis (void) |
9ae8ffe7 | 3259 | { |
c582d54a | 3260 | unsigned int maxreg = max_reg_num (); |
ea64ef27 | 3261 | int changed, pass; |
b3694847 SS |
3262 | int i; |
3263 | unsigned int ui; | |
d36a28b8 DM |
3264 | rtx_insn *insn; |
3265 | rtx val; | |
131db6b8 SB |
3266 | int rpo_cnt; |
3267 | int *rpo; | |
9ae8ffe7 | 3268 | |
0d446150 JH |
3269 | timevar_push (TV_ALIAS_ANALYSIS); |
3270 | ||
92390dd1 | 3271 | vec_safe_grow_cleared (reg_known_value, maxreg - FIRST_PSEUDO_REGISTER); |
9ff3c7ca | 3272 | reg_known_equiv_p = sbitmap_alloc (maxreg - FIRST_PSEUDO_REGISTER); |
dd3d1ec0 | 3273 | bitmap_clear (reg_known_equiv_p); |
9ae8ffe7 | 3274 | |
08c79682 | 3275 | /* If we have memory allocated from the previous run, use it. */ |
c582d54a | 3276 | if (old_reg_base_value) |
08c79682 KH |
3277 | reg_base_value = old_reg_base_value; |
3278 | ||
3279 | if (reg_base_value) | |
9771b263 | 3280 | reg_base_value->truncate (0); |
08c79682 | 3281 | |
9771b263 | 3282 | vec_safe_grow_cleared (reg_base_value, maxreg); |
ac606739 | 3283 | |
5ed6ace5 | 3284 | new_reg_base_value = XNEWVEC (rtx, maxreg); |
d630245f | 3285 | reg_seen = sbitmap_alloc (maxreg); |
ec907dd8 JL |
3286 | |
3287 | /* The basic idea is that each pass through this loop will use the | |
3288 | "constant" information from the previous pass to propagate alias | |
3289 | information through another level of assignments. | |
3290 | ||
131db6b8 SB |
3291 | The propagation is done on the CFG in reverse post-order, to propagate |
3292 | things forward as far as possible in each iteration. | |
3293 | ||
ec907dd8 JL |
3294 | This could get expensive if the assignment chains are long. Maybe |
3295 | we should throttle the number of iterations, possibly based on | |
6e73e666 | 3296 | the optimization level or flag_expensive_optimizations. |
ec907dd8 JL |
3297 | |
3298 | We could propagate more information in the first pass by making use | |
6fb5fa3c | 3299 | of DF_REG_DEF_COUNT to determine immediately that the alias information |
ea64ef27 JL |
3300 | for a pseudo is "constant". |
3301 | ||
3302 | A program with an uninitialized variable can cause an infinite loop | |
3303 | here. Instead of doing a full dataflow analysis to detect such problems | |
3304 | we just cap the number of iterations for the loop. | |
3305 | ||
3306 | The state of the arrays for the set chain in question does not matter | |
3307 | since the program has undefined behavior. */ | |
6e73e666 | 3308 | |
0cae8d31 | 3309 | rpo = XNEWVEC (int, n_basic_blocks_for_fn (cfun)); |
131db6b8 SB |
3310 | rpo_cnt = pre_and_rev_post_order_compute (NULL, rpo, false); |
3311 | ||
e86a9946 RS |
3312 | /* The prologue/epilogue insns are not threaded onto the |
3313 | insn chain until after reload has completed. Thus, | |
3314 | there is no sense wasting time checking if INSN is in | |
3315 | the prologue/epilogue until after reload has completed. */ | |
3316 | bool could_be_prologue_epilogue = ((targetm.have_prologue () | |
3317 | || targetm.have_epilogue ()) | |
3318 | && reload_completed); | |
3319 | ||
ea64ef27 | 3320 | pass = 0; |
6e73e666 | 3321 | do |
ec907dd8 JL |
3322 | { |
3323 | /* Assume nothing will change this iteration of the loop. */ | |
3324 | changed = 0; | |
3325 | ||
ec907dd8 | 3326 | /* We want to assign the same IDs each iteration of this loop, so |
9fc37b2b RS |
3327 | start counting from one each iteration of the loop. */ |
3328 | unique_id = 1; | |
ec907dd8 | 3329 | |
f5143c46 | 3330 | /* We're at the start of the function each iteration through the |
ec907dd8 | 3331 | loop, so we're copying arguments. */ |
83bbd9b6 | 3332 | copying_arguments = true; |
9ae8ffe7 | 3333 | |
6e73e666 | 3334 | /* Wipe the potential alias information clean for this pass. */ |
c582d54a | 3335 | memset (new_reg_base_value, 0, maxreg * sizeof (rtx)); |
8072f69c | 3336 | |
6e73e666 | 3337 | /* Wipe the reg_seen array clean. */ |
f61e445a | 3338 | bitmap_clear (reg_seen); |
9ae8ffe7 | 3339 | |
356610cb EB |
3340 | /* Initialize the alias information for this pass. */ |
3341 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
e6eacdc9 RS |
3342 | if (static_reg_base_value[i] |
3343 | /* Don't treat the hard frame pointer as special if we | |
3344 | eliminated the frame pointer to the stack pointer instead. */ | |
3345 | && !(i == HARD_FRAME_POINTER_REGNUM | |
3346 | && reload_completed | |
3347 | && !frame_pointer_needed | |
3348 | && targetm.can_eliminate (FRAME_POINTER_REGNUM, | |
3349 | STACK_POINTER_REGNUM))) | |
356610cb EB |
3350 | { |
3351 | new_reg_base_value[i] = static_reg_base_value[i]; | |
3352 | bitmap_set_bit (reg_seen, i); | |
3353 | } | |
6e73e666 | 3354 | |
ec907dd8 | 3355 | /* Walk the insns adding values to the new_reg_base_value array. */ |
131db6b8 | 3356 | for (i = 0; i < rpo_cnt; i++) |
9ae8ffe7 | 3357 | { |
06e28de2 | 3358 | basic_block bb = BASIC_BLOCK_FOR_FN (cfun, rpo[i]); |
131db6b8 | 3359 | FOR_BB_INSNS (bb, insn) |
ec907dd8 | 3360 | { |
131db6b8 SB |
3361 | if (NONDEBUG_INSN_P (insn)) |
3362 | { | |
3363 | rtx note, set; | |
efc9bd41 | 3364 | |
e86a9946 | 3365 | if (could_be_prologue_epilogue |
131db6b8 SB |
3366 | && prologue_epilogue_contains (insn)) |
3367 | continue; | |
efc9bd41 | 3368 | |
131db6b8 SB |
3369 | /* If this insn has a noalias note, process it, Otherwise, |
3370 | scan for sets. A simple set will have no side effects | |
3371 | which could change the base value of any other register. */ | |
6e73e666 | 3372 | |
131db6b8 SB |
3373 | if (GET_CODE (PATTERN (insn)) == SET |
3374 | && REG_NOTES (insn) != 0 | |
3375 | && find_reg_note (insn, REG_NOALIAS, NULL_RTX)) | |
3376 | record_set (SET_DEST (PATTERN (insn)), NULL_RTX, NULL); | |
3377 | else | |
3378 | note_stores (PATTERN (insn), record_set, NULL); | |
6e73e666 | 3379 | |
131db6b8 | 3380 | set = single_set (insn); |
6e73e666 | 3381 | |
131db6b8 SB |
3382 | if (set != 0 |
3383 | && REG_P (SET_DEST (set)) | |
3384 | && REGNO (SET_DEST (set)) >= FIRST_PSEUDO_REGISTER) | |
713f41f9 | 3385 | { |
131db6b8 SB |
3386 | unsigned int regno = REGNO (SET_DEST (set)); |
3387 | rtx src = SET_SRC (set); | |
3388 | rtx t; | |
3389 | ||
3390 | note = find_reg_equal_equiv_note (insn); | |
3391 | if (note && REG_NOTE_KIND (note) == REG_EQUAL | |
3392 | && DF_REG_DEF_COUNT (regno) != 1) | |
3393 | note = NULL_RTX; | |
3394 | ||
3395 | if (note != NULL_RTX | |
3396 | && GET_CODE (XEXP (note, 0)) != EXPR_LIST | |
3397 | && ! rtx_varies_p (XEXP (note, 0), 1) | |
3398 | && ! reg_overlap_mentioned_p (SET_DEST (set), | |
3399 | XEXP (note, 0))) | |
3400 | { | |
3401 | set_reg_known_value (regno, XEXP (note, 0)); | |
3402 | set_reg_known_equiv_p (regno, | |
3403 | REG_NOTE_KIND (note) == REG_EQUIV); | |
3404 | } | |
3405 | else if (DF_REG_DEF_COUNT (regno) == 1 | |
3406 | && GET_CODE (src) == PLUS | |
3407 | && REG_P (XEXP (src, 0)) | |
3408 | && (t = get_reg_known_value (REGNO (XEXP (src, 0)))) | |
3409 | && CONST_INT_P (XEXP (src, 1))) | |
3410 | { | |
3411 | t = plus_constant (GET_MODE (src), t, | |
3412 | INTVAL (XEXP (src, 1))); | |
3413 | set_reg_known_value (regno, t); | |
3414 | set_reg_known_equiv_p (regno, false); | |
3415 | } | |
3416 | else if (DF_REG_DEF_COUNT (regno) == 1 | |
3417 | && ! rtx_varies_p (src, 1)) | |
3418 | { | |
3419 | set_reg_known_value (regno, src); | |
3420 | set_reg_known_equiv_p (regno, false); | |
3421 | } | |
713f41f9 | 3422 | } |
6e73e666 | 3423 | } |
131db6b8 SB |
3424 | else if (NOTE_P (insn) |
3425 | && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG) | |
3426 | copying_arguments = false; | |
ec907dd8 | 3427 | } |
6e73e666 | 3428 | } |
ec907dd8 | 3429 | |
6e73e666 | 3430 | /* Now propagate values from new_reg_base_value to reg_base_value. */ |
62e5bf5d | 3431 | gcc_assert (maxreg == (unsigned int) max_reg_num ()); |
c22cacf3 | 3432 | |
c582d54a | 3433 | for (ui = 0; ui < maxreg; ui++) |
6e73e666 | 3434 | { |
e51712db | 3435 | if (new_reg_base_value[ui] |
9771b263 DN |
3436 | && new_reg_base_value[ui] != (*reg_base_value)[ui] |
3437 | && ! rtx_equal_p (new_reg_base_value[ui], (*reg_base_value)[ui])) | |
ec907dd8 | 3438 | { |
9771b263 | 3439 | (*reg_base_value)[ui] = new_reg_base_value[ui]; |
6e73e666 | 3440 | changed = 1; |
ec907dd8 | 3441 | } |
9ae8ffe7 | 3442 | } |
9ae8ffe7 | 3443 | } |
6e73e666 | 3444 | while (changed && ++pass < MAX_ALIAS_LOOP_PASSES); |
131db6b8 | 3445 | XDELETEVEC (rpo); |
9ae8ffe7 JL |
3446 | |
3447 | /* Fill in the remaining entries. */ | |
9771b263 | 3448 | FOR_EACH_VEC_ELT (*reg_known_value, i, val) |
9ff3c7ca SB |
3449 | { |
3450 | int regno = i + FIRST_PSEUDO_REGISTER; | |
3451 | if (! val) | |
3452 | set_reg_known_value (regno, regno_reg_rtx[regno]); | |
3453 | } | |
9ae8ffe7 | 3454 | |
e05e2395 MM |
3455 | /* Clean up. */ |
3456 | free (new_reg_base_value); | |
ec907dd8 | 3457 | new_reg_base_value = 0; |
d630245f | 3458 | sbitmap_free (reg_seen); |
9ae8ffe7 | 3459 | reg_seen = 0; |
0d446150 | 3460 | timevar_pop (TV_ALIAS_ANALYSIS); |
9ae8ffe7 JL |
3461 | } |
3462 | ||
61630b27 JJ |
3463 | /* Equate REG_BASE_VALUE (reg1) to REG_BASE_VALUE (reg2). |
3464 | Special API for var-tracking pass purposes. */ | |
3465 | ||
3466 | void | |
3467 | vt_equate_reg_base_value (const_rtx reg1, const_rtx reg2) | |
3468 | { | |
9771b263 | 3469 | (*reg_base_value)[REGNO (reg1)] = REG_BASE_VALUE (reg2); |
61630b27 JJ |
3470 | } |
3471 | ||
9ae8ffe7 | 3472 | void |
4682ae04 | 3473 | end_alias_analysis (void) |
9ae8ffe7 | 3474 | { |
c582d54a | 3475 | old_reg_base_value = reg_base_value; |
9771b263 | 3476 | vec_free (reg_known_value); |
9ff3c7ca | 3477 | sbitmap_free (reg_known_equiv_p); |
9ae8ffe7 | 3478 | } |
e2500fed | 3479 | |
3ecf9d13 JH |
3480 | void |
3481 | dump_alias_stats_in_alias_c (FILE *s) | |
3482 | { | |
3483 | fprintf (s, " TBAA oracle: %llu disambiguations %llu queries\n" | |
3484 | " %llu are in alias set 0\n" | |
3485 | " %llu queries asked about the same object\n" | |
3486 | " %llu queries asked about the same alias set\n" | |
3487 | " %llu access volatile\n" | |
6e042ef4 JH |
3488 | " %llu are dependent in the DAG\n" |
3489 | " %llu are aritificially in conflict with void *\n", | |
3ecf9d13 JH |
3490 | alias_stats.num_disambiguated, |
3491 | alias_stats.num_alias_zero + alias_stats.num_same_alias_set | |
3492 | + alias_stats.num_same_objects + alias_stats.num_volatile | |
6e042ef4 JH |
3493 | + alias_stats.num_dag + alias_stats.num_disambiguated |
3494 | + alias_stats.num_universal, | |
3ecf9d13 | 3495 | alias_stats.num_alias_zero, alias_stats.num_same_alias_set, |
6e042ef4 JH |
3496 | alias_stats.num_same_objects, alias_stats.num_volatile, |
3497 | alias_stats.num_dag, alias_stats.num_universal); | |
3ecf9d13 | 3498 | } |
e2500fed | 3499 | #include "gt-alias.h" |