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9ae8ffe7 | 1 | /* Alias analysis for GNU C |
cbe34bb5 | 2 | Copyright (C) 1997-2017 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 MM |
128 | |
129 | /* The children of the alias set. These are not just the immediate | |
95bd1dd7 | 130 | children, but, in fact, all descendants. So, if we have: |
3932261a | 131 | |
ca7fd9cd | 132 | struct T { struct S s; float f; } |
3932261a MM |
133 | |
134 | continuing our example above, the children here will be all of | |
135 | `int', `double', `float', and `struct S'. */ | |
fb5c464a | 136 | hash_map<alias_set_hash, int> *children; |
6e042ef4 JH |
137 | |
138 | /* Nonzero if would have a child of zero: this effectively makes this | |
139 | alias set the same as alias set zero. */ | |
140 | bool has_zero_child; | |
141 | /* Nonzero if alias set corresponds to pointer type itself (i.e. not to | |
142 | aggregate contaiing pointer. | |
143 | This is used for a special case where we need an universal pointer type | |
144 | compatible with all other pointer types. */ | |
145 | bool is_pointer; | |
146 | /* Nonzero if is_pointer or if one of childs have has_pointer set. */ | |
147 | bool has_pointer; | |
b604074c | 148 | }; |
9ae8ffe7 | 149 | |
ed7a4b4b | 150 | static int rtx_equal_for_memref_p (const_rtx, const_rtx); |
4682ae04 | 151 | static int memrefs_conflict_p (int, rtx, int, rtx, HOST_WIDE_INT); |
7bc980e1 | 152 | static void record_set (rtx, const_rtx, void *); |
ef4bddc2 RS |
153 | static int base_alias_check (rtx, rtx, rtx, rtx, machine_mode, |
154 | machine_mode); | |
4682ae04 | 155 | static rtx find_base_value (rtx); |
4f588890 | 156 | static int mems_in_disjoint_alias_sets_p (const_rtx, const_rtx); |
02ced957 | 157 | static alias_set_entry *get_alias_set_entry (alias_set_type); |
4682ae04 | 158 | static tree decl_for_component_ref (tree); |
bd280792 | 159 | static int write_dependence_p (const_rtx, |
ef4bddc2 | 160 | const_rtx, machine_mode, rtx, |
bd280792 | 161 | bool, bool, bool); |
73e48cb3 | 162 | static int compare_base_symbol_refs (const_rtx, const_rtx); |
4682ae04 | 163 | |
aa317c97 | 164 | static void memory_modified_1 (rtx, const_rtx, void *); |
9ae8ffe7 | 165 | |
3ecf9d13 JH |
166 | /* Query statistics for the different low-level disambiguators. |
167 | A high-level query may trigger multiple of them. */ | |
168 | ||
169 | static struct { | |
170 | unsigned long long num_alias_zero; | |
171 | unsigned long long num_same_alias_set; | |
172 | unsigned long long num_same_objects; | |
173 | unsigned long long num_volatile; | |
174 | unsigned long long num_dag; | |
6e042ef4 | 175 | unsigned long long num_universal; |
3ecf9d13 JH |
176 | unsigned long long num_disambiguated; |
177 | } alias_stats; | |
178 | ||
179 | ||
9ae8ffe7 JL |
180 | /* Set up all info needed to perform alias analysis on memory references. */ |
181 | ||
d4b60170 | 182 | /* Returns the size in bytes of the mode of X. */ |
9ae8ffe7 JL |
183 | #define SIZE_FOR_MODE(X) (GET_MODE_SIZE (GET_MODE (X))) |
184 | ||
ea64ef27 | 185 | /* Cap the number of passes we make over the insns propagating alias |
131db6b8 SB |
186 | information through set chains. |
187 | ??? 10 is a completely arbitrary choice. This should be based on the | |
188 | maximum loop depth in the CFG, but we do not have this information | |
189 | available (even if current_loops _is_ available). */ | |
ea64ef27 | 190 | #define MAX_ALIAS_LOOP_PASSES 10 |
ca7fd9cd | 191 | |
9ae8ffe7 JL |
192 | /* reg_base_value[N] gives an address to which register N is related. |
193 | If all sets after the first add or subtract to the current value | |
194 | or otherwise modify it so it does not point to a different top level | |
195 | object, reg_base_value[N] is equal to the address part of the source | |
2a2c8203 JC |
196 | of the first set. |
197 | ||
198 | A base address can be an ADDRESS, SYMBOL_REF, or LABEL_REF. ADDRESS | |
9fc37b2b | 199 | expressions represent three types of base: |
b3b5ad95 | 200 | |
9fc37b2b RS |
201 | 1. incoming arguments. There is just one ADDRESS to represent all |
202 | arguments, since we do not know at this level whether accesses | |
203 | based on different arguments can alias. The ADDRESS has id 0. | |
b3b5ad95 | 204 | |
9fc37b2b RS |
205 | 2. stack_pointer_rtx, frame_pointer_rtx, hard_frame_pointer_rtx |
206 | (if distinct from frame_pointer_rtx) and arg_pointer_rtx. | |
207 | Each of these rtxes has a separate ADDRESS associated with it, | |
208 | each with a negative id. | |
209 | ||
210 | GCC is (and is required to be) precise in which register it | |
211 | chooses to access a particular region of stack. We can therefore | |
212 | assume that accesses based on one of these rtxes do not alias | |
213 | accesses based on another of these rtxes. | |
214 | ||
215 | 3. bases that are derived from malloc()ed memory (REG_NOALIAS). | |
216 | Each such piece of memory has a separate ADDRESS associated | |
217 | with it, each with an id greater than 0. | |
218 | ||
219 | Accesses based on one ADDRESS do not alias accesses based on other | |
220 | ADDRESSes. Accesses based on ADDRESSes in groups (2) and (3) do not | |
221 | alias globals either; the ADDRESSes have Pmode to indicate this. | |
222 | The ADDRESS in group (1) _may_ alias globals; it has VOIDmode to | |
223 | indicate this. */ | |
2a2c8203 | 224 | |
9771b263 | 225 | static GTY(()) vec<rtx, va_gc> *reg_base_value; |
ac606739 | 226 | static rtx *new_reg_base_value; |
c582d54a | 227 | |
9fc37b2b RS |
228 | /* The single VOIDmode ADDRESS that represents all argument bases. |
229 | It has id 0. */ | |
230 | static GTY(()) rtx arg_base_value; | |
231 | ||
232 | /* Used to allocate unique ids to each REG_NOALIAS ADDRESS. */ | |
233 | static int unique_id; | |
234 | ||
c582d54a JH |
235 | /* We preserve the copy of old array around to avoid amount of garbage |
236 | produced. About 8% of garbage produced were attributed to this | |
237 | array. */ | |
9771b263 | 238 | static GTY((deletable)) vec<rtx, va_gc> *old_reg_base_value; |
d4b60170 | 239 | |
9e412ca3 RS |
240 | /* Values of XINT (address, 0) of Pmode ADDRESS rtxes for special |
241 | registers. */ | |
242 | #define UNIQUE_BASE_VALUE_SP -1 | |
243 | #define UNIQUE_BASE_VALUE_ARGP -2 | |
244 | #define UNIQUE_BASE_VALUE_FP -3 | |
245 | #define UNIQUE_BASE_VALUE_HFP -4 | |
246 | ||
7bf84454 RS |
247 | #define static_reg_base_value \ |
248 | (this_target_rtl->x_static_reg_base_value) | |
bf1660a6 | 249 | |
9771b263 DN |
250 | #define REG_BASE_VALUE(X) \ |
251 | (REGNO (X) < vec_safe_length (reg_base_value) \ | |
252 | ? (*reg_base_value)[REGNO (X)] : 0) | |
9ae8ffe7 | 253 | |
c13e8210 | 254 | /* Vector indexed by N giving the initial (unchanging) value known for |
9ff3c7ca | 255 | pseudo-register N. This vector is initialized in init_alias_analysis, |
bb1acb3e | 256 | and does not change until end_alias_analysis is called. */ |
9771b263 | 257 | static GTY(()) vec<rtx, va_gc> *reg_known_value; |
9ae8ffe7 JL |
258 | |
259 | /* Vector recording for each reg_known_value whether it is due to a | |
260 | REG_EQUIV note. Future passes (viz., reload) may replace the | |
261 | pseudo with the equivalent expression and so we account for the | |
ac3d9668 RK |
262 | dependences that would be introduced if that happens. |
263 | ||
264 | The REG_EQUIV notes created in assign_parms may mention the arg | |
265 | pointer, and there are explicit insns in the RTL that modify the | |
266 | arg pointer. Thus we must ensure that such insns don't get | |
267 | scheduled across each other because that would invalidate the | |
268 | REG_EQUIV notes. One could argue that the REG_EQUIV notes are | |
269 | wrong, but solving the problem in the scheduler will likely give | |
270 | better code, so we do it here. */ | |
9ff3c7ca | 271 | static sbitmap reg_known_equiv_p; |
9ae8ffe7 | 272 | |
2a2c8203 JC |
273 | /* True when scanning insns from the start of the rtl to the |
274 | NOTE_INSN_FUNCTION_BEG note. */ | |
83bbd9b6 | 275 | static bool copying_arguments; |
9ae8ffe7 | 276 | |
1a5640b4 | 277 | |
3932261a | 278 | /* The splay-tree used to store the various alias set entries. */ |
02ced957 | 279 | static GTY (()) vec<alias_set_entry *, va_gc> *alias_sets; |
ac3d9668 | 280 | \f |
55b34b5f RG |
281 | /* Build a decomposed reference object for querying the alias-oracle |
282 | from the MEM rtx and store it in *REF. | |
283 | Returns false if MEM is not suitable for the alias-oracle. */ | |
284 | ||
285 | static bool | |
286 | ao_ref_from_mem (ao_ref *ref, const_rtx mem) | |
287 | { | |
288 | tree expr = MEM_EXPR (mem); | |
289 | tree base; | |
290 | ||
291 | if (!expr) | |
292 | return false; | |
293 | ||
294 | ao_ref_init (ref, expr); | |
295 | ||
296 | /* Get the base of the reference and see if we have to reject or | |
297 | adjust it. */ | |
298 | base = ao_ref_base (ref); | |
299 | if (base == NULL_TREE) | |
300 | return false; | |
301 | ||
ef7a9fb8 RB |
302 | /* The tree oracle doesn't like bases that are neither decls |
303 | nor indirect references of SSA names. */ | |
304 | if (!(DECL_P (base) | |
305 | || (TREE_CODE (base) == MEM_REF | |
306 | && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME) | |
307 | || (TREE_CODE (base) == TARGET_MEM_REF | |
308 | && TREE_CODE (TMR_BASE (base)) == SSA_NAME))) | |
d15adbeb | 309 | return false; |
55b34b5f RG |
310 | |
311 | /* If this is a reference based on a partitioned decl replace the | |
ef7a9fb8 | 312 | base with a MEM_REF of the pointer representative we |
55b34b5f | 313 | created during stack slot partitioning. */ |
8813a647 | 314 | if (VAR_P (base) |
ef7a9fb8 | 315 | && ! is_global_var (base) |
55b34b5f RG |
316 | && cfun->gimple_df->decls_to_pointers != NULL) |
317 | { | |
39c8aaa4 | 318 | tree *namep = cfun->gimple_df->decls_to_pointers->get (base); |
55b34b5f | 319 | if (namep) |
39c8aaa4 | 320 | ref->base = build_simple_mem_ref (*namep); |
d15adbeb | 321 | } |
55b34b5f RG |
322 | |
323 | ref->ref_alias_set = MEM_ALIAS_SET (mem); | |
324 | ||
f68396a1 RG |
325 | /* If MEM_OFFSET or MEM_SIZE are unknown what we got from MEM_EXPR |
326 | is conservative, so trust it. */ | |
527210c4 | 327 | if (!MEM_OFFSET_KNOWN_P (mem) |
f5541398 | 328 | || !MEM_SIZE_KNOWN_P (mem)) |
f68396a1 | 329 | return true; |
366f945f | 330 | |
e8024441 RB |
331 | /* If MEM_OFFSET/MEM_SIZE get us outside of ref->offset/ref->max_size |
332 | drop ref->ref. */ | |
527210c4 | 333 | if (MEM_OFFSET (mem) < 0 |
e8024441 RB |
334 | || (ref->max_size != -1 |
335 | && ((MEM_OFFSET (mem) + MEM_SIZE (mem)) * BITS_PER_UNIT | |
336 | > ref->max_size))) | |
337 | ref->ref = NULL_TREE; | |
b0e96404 | 338 | |
e8024441 RB |
339 | /* Refine size and offset we got from analyzing MEM_EXPR by using |
340 | MEM_SIZE and MEM_OFFSET. */ | |
f68396a1 | 341 | |
527210c4 | 342 | ref->offset += MEM_OFFSET (mem) * BITS_PER_UNIT; |
f5541398 | 343 | ref->size = MEM_SIZE (mem) * BITS_PER_UNIT; |
b0e96404 RG |
344 | |
345 | /* The MEM may extend into adjacent fields, so adjust max_size if | |
346 | necessary. */ | |
347 | if (ref->max_size != -1 | |
348 | && ref->size > ref->max_size) | |
349 | ref->max_size = ref->size; | |
350 | ||
351 | /* If MEM_OFFSET and MEM_SIZE get us outside of the base object of | |
352 | the MEM_EXPR punt. This happens for STRICT_ALIGNMENT targets a lot. */ | |
353 | if (MEM_EXPR (mem) != get_spill_slot_decl (false) | |
354 | && (ref->offset < 0 | |
355 | || (DECL_P (ref->base) | |
807e902e KZ |
356 | && (DECL_SIZE (ref->base) == NULL_TREE |
357 | || TREE_CODE (DECL_SIZE (ref->base)) != INTEGER_CST | |
358 | || wi::ltu_p (wi::to_offset (DECL_SIZE (ref->base)), | |
359 | ref->offset + ref->size))))) | |
b0e96404 | 360 | return false; |
55b34b5f RG |
361 | |
362 | return true; | |
363 | } | |
364 | ||
365 | /* Query the alias-oracle on whether the two memory rtx X and MEM may | |
366 | alias. If TBAA_P is set also apply TBAA. Returns true if the | |
367 | two rtxen may alias, false otherwise. */ | |
368 | ||
369 | static bool | |
370 | rtx_refs_may_alias_p (const_rtx x, const_rtx mem, bool tbaa_p) | |
371 | { | |
372 | ao_ref ref1, ref2; | |
373 | ||
374 | if (!ao_ref_from_mem (&ref1, x) | |
375 | || !ao_ref_from_mem (&ref2, mem)) | |
376 | return true; | |
377 | ||
55e3bc4c RG |
378 | return refs_may_alias_p_1 (&ref1, &ref2, |
379 | tbaa_p | |
380 | && MEM_ALIAS_SET (x) != 0 | |
381 | && MEM_ALIAS_SET (mem) != 0); | |
55b34b5f RG |
382 | } |
383 | ||
3932261a MM |
384 | /* Returns a pointer to the alias set entry for ALIAS_SET, if there is |
385 | such an entry, or NULL otherwise. */ | |
386 | ||
02ced957 | 387 | static inline alias_set_entry * |
4862826d | 388 | get_alias_set_entry (alias_set_type alias_set) |
3932261a | 389 | { |
9771b263 | 390 | return (*alias_sets)[alias_set]; |
3932261a MM |
391 | } |
392 | ||
ac3d9668 RK |
393 | /* Returns nonzero if the alias sets for MEM1 and MEM2 are such that |
394 | the two MEMs cannot alias each other. */ | |
3932261a | 395 | |
9ddb66ca | 396 | static inline int |
4f588890 | 397 | mems_in_disjoint_alias_sets_p (const_rtx mem1, const_rtx mem2) |
3932261a | 398 | { |
598f8eca RB |
399 | return (flag_strict_aliasing |
400 | && ! alias_sets_conflict_p (MEM_ALIAS_SET (mem1), | |
401 | MEM_ALIAS_SET (mem2))); | |
1da68f56 | 402 | } |
3932261a | 403 | |
c58936b6 DB |
404 | /* Return true if the first alias set is a subset of the second. */ |
405 | ||
406 | bool | |
4862826d | 407 | alias_set_subset_of (alias_set_type set1, alias_set_type set2) |
c58936b6 | 408 | { |
02ced957 | 409 | alias_set_entry *ase2; |
c58936b6 | 410 | |
bd04cddf JH |
411 | /* Disable TBAA oracle with !flag_strict_aliasing. */ |
412 | if (!flag_strict_aliasing) | |
413 | return true; | |
414 | ||
c58936b6 DB |
415 | /* Everything is a subset of the "aliases everything" set. */ |
416 | if (set2 == 0) | |
417 | return true; | |
418 | ||
6e042ef4 JH |
419 | /* Check if set1 is a subset of set2. */ |
420 | ase2 = get_alias_set_entry (set2); | |
421 | if (ase2 != 0 | |
422 | && (ase2->has_zero_child | |
423 | || (ase2->children && ase2->children->get (set1)))) | |
c58936b6 | 424 | return true; |
6e042ef4 JH |
425 | |
426 | /* As a special case we consider alias set of "void *" to be both subset | |
427 | and superset of every alias set of a pointer. This extra symmetry does | |
428 | not matter for alias_sets_conflict_p but it makes aliasing_component_refs_p | |
429 | to return true on the following testcase: | |
430 | ||
431 | void *ptr; | |
432 | char **ptr2=(char **)&ptr; | |
433 | *ptr2 = ... | |
434 | ||
435 | Additionally if a set contains universal pointer, we consider every pointer | |
436 | to be a subset of it, but we do not represent this explicitely - doing so | |
437 | would require us to update transitive closure each time we introduce new | |
438 | pointer type. This makes aliasing_component_refs_p to return true | |
439 | on the following testcase: | |
440 | ||
441 | struct a {void *ptr;} | |
442 | char **ptr = (char **)&a.ptr; | |
443 | ptr = ... | |
444 | ||
445 | This makes void * truly universal pointer type. See pointer handling in | |
446 | get_alias_set for more details. */ | |
447 | if (ase2 && ase2->has_pointer) | |
448 | { | |
02ced957 | 449 | alias_set_entry *ase1 = get_alias_set_entry (set1); |
6e042ef4 JH |
450 | |
451 | if (ase1 && ase1->is_pointer) | |
452 | { | |
453 | alias_set_type voidptr_set = TYPE_ALIAS_SET (ptr_type_node); | |
454 | /* If one is ptr_type_node and other is pointer, then we consider | |
455 | them subset of each other. */ | |
456 | if (set1 == voidptr_set || set2 == voidptr_set) | |
457 | return true; | |
458 | /* If SET2 contains universal pointer's alias set, then we consdier | |
459 | every (non-universal) pointer. */ | |
460 | if (ase2->children && set1 != voidptr_set | |
461 | && ase2->children->get (voidptr_set)) | |
462 | return true; | |
463 | } | |
464 | } | |
c58936b6 DB |
465 | return false; |
466 | } | |
467 | ||
1da68f56 RK |
468 | /* Return 1 if the two specified alias sets may conflict. */ |
469 | ||
470 | int | |
4862826d | 471 | alias_sets_conflict_p (alias_set_type set1, alias_set_type set2) |
1da68f56 | 472 | { |
02ced957 TS |
473 | alias_set_entry *ase1; |
474 | alias_set_entry *ase2; | |
1da68f56 | 475 | |
836f7794 EB |
476 | /* The easy case. */ |
477 | if (alias_sets_must_conflict_p (set1, set2)) | |
1da68f56 | 478 | return 1; |
3932261a | 479 | |
3bdf5ad1 | 480 | /* See if the first alias set is a subset of the second. */ |
6e042ef4 JH |
481 | ase1 = get_alias_set_entry (set1); |
482 | if (ase1 != 0 | |
483 | && ase1->children && ase1->children->get (set2)) | |
3ecf9d13 JH |
484 | { |
485 | ++alias_stats.num_dag; | |
486 | return 1; | |
487 | } | |
3932261a MM |
488 | |
489 | /* Now do the same, but with the alias sets reversed. */ | |
6e042ef4 JH |
490 | ase2 = get_alias_set_entry (set2); |
491 | if (ase2 != 0 | |
492 | && ase2->children && ase2->children->get (set1)) | |
3ecf9d13 JH |
493 | { |
494 | ++alias_stats.num_dag; | |
495 | return 1; | |
496 | } | |
6e042ef4 JH |
497 | |
498 | /* We want void * to be compatible with any other pointer without | |
499 | really dropping it to alias set 0. Doing so would make it | |
500 | compatible with all non-pointer types too. | |
501 | ||
502 | This is not strictly necessary by the C/C++ language | |
503 | standards, but avoids common type punning mistakes. In | |
504 | addition to that, we need the existence of such universal | |
505 | pointer to implement Fortran's C_PTR type (which is defined as | |
506 | type compatible with all C pointers). */ | |
507 | if (ase1 && ase2 && ase1->has_pointer && ase2->has_pointer) | |
508 | { | |
509 | alias_set_type voidptr_set = TYPE_ALIAS_SET (ptr_type_node); | |
510 | ||
511 | /* If one of the sets corresponds to universal pointer, | |
512 | we consider it to conflict with anything that is | |
513 | or contains pointer. */ | |
514 | if (set1 == voidptr_set || set2 == voidptr_set) | |
515 | { | |
516 | ++alias_stats.num_universal; | |
517 | return true; | |
518 | } | |
519 | /* If one of sets is (non-universal) pointer and the other | |
520 | contains universal pointer, we also get conflict. */ | |
521 | if (ase1->is_pointer && set2 != voidptr_set | |
522 | && ase2->children && ase2->children->get (voidptr_set)) | |
523 | { | |
524 | ++alias_stats.num_universal; | |
525 | return true; | |
526 | } | |
527 | if (ase2->is_pointer && set1 != voidptr_set | |
528 | && ase1->children && ase1->children->get (voidptr_set)) | |
529 | { | |
530 | ++alias_stats.num_universal; | |
531 | return true; | |
532 | } | |
533 | } | |
534 | ||
3ecf9d13 | 535 | ++alias_stats.num_disambiguated; |
3932261a | 536 | |
1da68f56 | 537 | /* The two alias sets are distinct and neither one is the |
836f7794 | 538 | child of the other. Therefore, they cannot conflict. */ |
1da68f56 | 539 | return 0; |
3932261a | 540 | } |
5399d643 | 541 | |
836f7794 | 542 | /* Return 1 if the two specified alias sets will always conflict. */ |
5399d643 JW |
543 | |
544 | int | |
4862826d | 545 | alias_sets_must_conflict_p (alias_set_type set1, alias_set_type set2) |
5399d643 | 546 | { |
bd04cddf JH |
547 | /* Disable TBAA oracle with !flag_strict_aliasing. */ |
548 | if (!flag_strict_aliasing) | |
549 | return 1; | |
3ecf9d13 JH |
550 | if (set1 == 0 || set2 == 0) |
551 | { | |
552 | ++alias_stats.num_alias_zero; | |
553 | return 1; | |
554 | } | |
555 | if (set1 == set2) | |
556 | { | |
557 | ++alias_stats.num_same_alias_set; | |
558 | return 1; | |
559 | } | |
5399d643 JW |
560 | |
561 | return 0; | |
562 | } | |
563 | ||
1da68f56 RK |
564 | /* Return 1 if any MEM object of type T1 will always conflict (using the |
565 | dependency routines in this file) with any MEM object of type T2. | |
566 | This is used when allocating temporary storage. If T1 and/or T2 are | |
567 | NULL_TREE, it means we know nothing about the storage. */ | |
568 | ||
569 | int | |
4682ae04 | 570 | objects_must_conflict_p (tree t1, tree t2) |
1da68f56 | 571 | { |
4862826d | 572 | alias_set_type set1, set2; |
82d610ec | 573 | |
e8ea2809 RK |
574 | /* If neither has a type specified, we don't know if they'll conflict |
575 | because we may be using them to store objects of various types, for | |
576 | example the argument and local variables areas of inlined functions. */ | |
981a4c34 | 577 | if (t1 == 0 && t2 == 0) |
e8ea2809 RK |
578 | return 0; |
579 | ||
1da68f56 | 580 | /* If they are the same type, they must conflict. */ |
3ecf9d13 JH |
581 | if (t1 == t2) |
582 | { | |
583 | ++alias_stats.num_same_objects; | |
584 | return 1; | |
585 | } | |
586 | /* Likewise if both are volatile. */ | |
587 | if (t1 != 0 && TYPE_VOLATILE (t1) && t2 != 0 && TYPE_VOLATILE (t2)) | |
588 | { | |
589 | ++alias_stats.num_volatile; | |
590 | return 1; | |
591 | } | |
1da68f56 | 592 | |
82d610ec RK |
593 | set1 = t1 ? get_alias_set (t1) : 0; |
594 | set2 = t2 ? get_alias_set (t2) : 0; | |
1da68f56 | 595 | |
836f7794 EB |
596 | /* We can't use alias_sets_conflict_p because we must make sure |
597 | that every subtype of t1 will conflict with every subtype of | |
82d610ec RK |
598 | t2 for which a pair of subobjects of these respective subtypes |
599 | overlaps on the stack. */ | |
836f7794 | 600 | return alias_sets_must_conflict_p (set1, set2); |
1da68f56 RK |
601 | } |
602 | \f | |
b4ada065 RB |
603 | /* Return the outermost parent of component present in the chain of |
604 | component references handled by get_inner_reference in T with the | |
605 | following property: | |
606 | - the component is non-addressable, or | |
607 | - the parent has alias set zero, | |
608 | or NULL_TREE if no such parent exists. In the former cases, the alias | |
609 | set of this parent is the alias set that must be used for T itself. */ | |
610 | ||
611 | tree | |
612 | component_uses_parent_alias_set_from (const_tree t) | |
6e24b709 | 613 | { |
b4ada065 | 614 | const_tree found = NULL_TREE; |
afe84921 | 615 | |
b4ada065 RB |
616 | while (handled_component_p (t)) |
617 | { | |
afe84921 RH |
618 | switch (TREE_CODE (t)) |
619 | { | |
620 | case COMPONENT_REF: | |
621 | if (DECL_NONADDRESSABLE_P (TREE_OPERAND (t, 1))) | |
b4ada065 | 622 | found = t; |
4aa83879 RB |
623 | /* Permit type-punning when accessing a union, provided the access |
624 | is directly through the union. For example, this code does not | |
625 | permit taking the address of a union member and then storing | |
626 | through it. Even the type-punning allowed here is a GCC | |
627 | extension, albeit a common and useful one; the C standard says | |
628 | that such accesses have implementation-defined behavior. */ | |
629 | else if (TREE_CODE (TREE_TYPE (TREE_OPERAND (t, 0))) == UNION_TYPE) | |
630 | found = t; | |
afe84921 RH |
631 | break; |
632 | ||
633 | case ARRAY_REF: | |
634 | case ARRAY_RANGE_REF: | |
635 | if (TYPE_NONALIASED_COMPONENT (TREE_TYPE (TREE_OPERAND (t, 0)))) | |
b4ada065 | 636 | found = t; |
afe84921 RH |
637 | break; |
638 | ||
639 | case REALPART_EXPR: | |
640 | case IMAGPART_EXPR: | |
641 | break; | |
642 | ||
b4ada065 RB |
643 | case BIT_FIELD_REF: |
644 | case VIEW_CONVERT_EXPR: | |
afe84921 | 645 | /* Bitfields and casts are never addressable. */ |
b4ada065 RB |
646 | found = t; |
647 | break; | |
648 | ||
649 | default: | |
650 | gcc_unreachable (); | |
afe84921 RH |
651 | } |
652 | ||
b4ada065 RB |
653 | if (get_alias_set (TREE_TYPE (TREE_OPERAND (t, 0))) == 0) |
654 | found = t; | |
655 | ||
afe84921 RH |
656 | t = TREE_OPERAND (t, 0); |
657 | } | |
b4ada065 RB |
658 | |
659 | if (found) | |
660 | return TREE_OPERAND (found, 0); | |
661 | ||
662 | return NULL_TREE; | |
6e24b709 RK |
663 | } |
664 | ||
f40333af RB |
665 | |
666 | /* Return whether the pointer-type T effective for aliasing may | |
667 | access everything and thus the reference has to be assigned | |
668 | alias-set zero. */ | |
669 | ||
670 | static bool | |
671 | ref_all_alias_ptr_type_p (const_tree t) | |
672 | { | |
673 | return (TREE_CODE (TREE_TYPE (t)) == VOID_TYPE | |
674 | || TYPE_REF_CAN_ALIAS_ALL (t)); | |
675 | } | |
676 | ||
5006671f RG |
677 | /* Return the alias set for the memory pointed to by T, which may be |
678 | either a type or an expression. Return -1 if there is nothing | |
679 | special about dereferencing T. */ | |
680 | ||
681 | static alias_set_type | |
682 | get_deref_alias_set_1 (tree t) | |
683 | { | |
5b21f0f3 | 684 | /* All we care about is the type. */ |
5006671f | 685 | if (! TYPE_P (t)) |
5b21f0f3 | 686 | t = TREE_TYPE (t); |
5006671f RG |
687 | |
688 | /* If we have an INDIRECT_REF via a void pointer, we don't | |
689 | know anything about what that might alias. Likewise if the | |
690 | pointer is marked that way. */ | |
f40333af | 691 | if (ref_all_alias_ptr_type_p (t)) |
5006671f RG |
692 | return 0; |
693 | ||
694 | return -1; | |
695 | } | |
696 | ||
697 | /* Return the alias set for the memory pointed to by T, which may be | |
698 | either a type or an expression. */ | |
699 | ||
700 | alias_set_type | |
701 | get_deref_alias_set (tree t) | |
702 | { | |
f40333af RB |
703 | /* If we're not doing any alias analysis, just assume everything |
704 | aliases everything else. */ | |
705 | if (!flag_strict_aliasing) | |
706 | return 0; | |
707 | ||
5006671f RG |
708 | alias_set_type set = get_deref_alias_set_1 (t); |
709 | ||
710 | /* Fall back to the alias-set of the pointed-to type. */ | |
711 | if (set == -1) | |
712 | { | |
713 | if (! TYPE_P (t)) | |
714 | t = TREE_TYPE (t); | |
715 | set = get_alias_set (TREE_TYPE (t)); | |
716 | } | |
717 | ||
718 | return set; | |
719 | } | |
720 | ||
f40333af RB |
721 | /* Return the pointer-type relevant for TBAA purposes from the |
722 | memory reference tree *T or NULL_TREE in which case *T is | |
723 | adjusted to point to the outermost component reference that | |
724 | can be used for assigning an alias set. */ | |
725 | ||
726 | static tree | |
727 | reference_alias_ptr_type_1 (tree *t) | |
728 | { | |
729 | tree inner; | |
730 | ||
731 | /* Get the base object of the reference. */ | |
732 | inner = *t; | |
733 | while (handled_component_p (inner)) | |
734 | { | |
735 | /* If there is a VIEW_CONVERT_EXPR in the chain we cannot use | |
736 | the type of any component references that wrap it to | |
737 | determine the alias-set. */ | |
738 | if (TREE_CODE (inner) == VIEW_CONVERT_EXPR) | |
739 | *t = TREE_OPERAND (inner, 0); | |
740 | inner = TREE_OPERAND (inner, 0); | |
741 | } | |
742 | ||
743 | /* Handle pointer dereferences here, they can override the | |
744 | alias-set. */ | |
745 | if (INDIRECT_REF_P (inner) | |
746 | && ref_all_alias_ptr_type_p (TREE_TYPE (TREE_OPERAND (inner, 0)))) | |
747 | return TREE_TYPE (TREE_OPERAND (inner, 0)); | |
748 | else if (TREE_CODE (inner) == TARGET_MEM_REF) | |
749 | return TREE_TYPE (TMR_OFFSET (inner)); | |
750 | else if (TREE_CODE (inner) == MEM_REF | |
751 | && ref_all_alias_ptr_type_p (TREE_TYPE (TREE_OPERAND (inner, 1)))) | |
752 | return TREE_TYPE (TREE_OPERAND (inner, 1)); | |
753 | ||
754 | /* If the innermost reference is a MEM_REF that has a | |
755 | conversion embedded treat it like a VIEW_CONVERT_EXPR above, | |
756 | using the memory access type for determining the alias-set. */ | |
757 | if (TREE_CODE (inner) == MEM_REF | |
758 | && (TYPE_MAIN_VARIANT (TREE_TYPE (inner)) | |
759 | != TYPE_MAIN_VARIANT | |
760 | (TREE_TYPE (TREE_TYPE (TREE_OPERAND (inner, 1)))))) | |
761 | return TREE_TYPE (TREE_OPERAND (inner, 1)); | |
762 | ||
b4ada065 RB |
763 | /* Otherwise, pick up the outermost object that we could have |
764 | a pointer to. */ | |
765 | tree tem = component_uses_parent_alias_set_from (*t); | |
766 | if (tem) | |
767 | *t = tem; | |
f40333af RB |
768 | |
769 | return NULL_TREE; | |
770 | } | |
771 | ||
772 | /* Return the pointer-type relevant for TBAA purposes from the | |
773 | gimple memory reference tree T. This is the type to be used for | |
774 | the offset operand of MEM_REF or TARGET_MEM_REF replacements of T | |
775 | and guarantees that get_alias_set will return the same alias | |
776 | set for T and the replacement. */ | |
777 | ||
778 | tree | |
779 | reference_alias_ptr_type (tree t) | |
780 | { | |
ebc1b29e RB |
781 | /* If the frontend assigns this alias-set zero, preserve that. */ |
782 | if (lang_hooks.get_alias_set (t) == 0) | |
783 | return ptr_type_node; | |
784 | ||
f40333af RB |
785 | tree ptype = reference_alias_ptr_type_1 (&t); |
786 | /* If there is a given pointer type for aliasing purposes, return it. */ | |
787 | if (ptype != NULL_TREE) | |
788 | return ptype; | |
789 | ||
790 | /* Otherwise build one from the outermost component reference we | |
791 | may use. */ | |
792 | if (TREE_CODE (t) == MEM_REF | |
793 | || TREE_CODE (t) == TARGET_MEM_REF) | |
794 | return TREE_TYPE (TREE_OPERAND (t, 1)); | |
795 | else | |
796 | return build_pointer_type (TYPE_MAIN_VARIANT (TREE_TYPE (t))); | |
797 | } | |
798 | ||
799 | /* Return whether the pointer-types T1 and T2 used to determine | |
800 | two alias sets of two references will yield the same answer | |
801 | from get_deref_alias_set. */ | |
802 | ||
803 | bool | |
804 | alias_ptr_types_compatible_p (tree t1, tree t2) | |
805 | { | |
806 | if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2)) | |
807 | return true; | |
808 | ||
809 | if (ref_all_alias_ptr_type_p (t1) | |
810 | || ref_all_alias_ptr_type_p (t2)) | |
811 | return false; | |
812 | ||
813 | return (TYPE_MAIN_VARIANT (TREE_TYPE (t1)) | |
814 | == TYPE_MAIN_VARIANT (TREE_TYPE (t2))); | |
815 | } | |
816 | ||
6e042ef4 JH |
817 | /* Create emptry alias set entry. */ |
818 | ||
02ced957 | 819 | alias_set_entry * |
6e042ef4 JH |
820 | init_alias_set_entry (alias_set_type set) |
821 | { | |
02ced957 | 822 | alias_set_entry *ase = ggc_alloc<alias_set_entry> (); |
6e042ef4 JH |
823 | ase->alias_set = set; |
824 | ase->children = NULL; | |
825 | ase->has_zero_child = false; | |
826 | ase->is_pointer = false; | |
827 | ase->has_pointer = false; | |
828 | gcc_checking_assert (!get_alias_set_entry (set)); | |
829 | (*alias_sets)[set] = ase; | |
830 | return ase; | |
831 | } | |
832 | ||
3bdf5ad1 RK |
833 | /* Return the alias set for T, which may be either a type or an |
834 | expression. Call language-specific routine for help, if needed. */ | |
835 | ||
4862826d | 836 | alias_set_type |
4682ae04 | 837 | get_alias_set (tree t) |
3bdf5ad1 | 838 | { |
4862826d | 839 | alias_set_type set; |
3bdf5ad1 | 840 | |
bd04cddf JH |
841 | /* We can not give up with -fno-strict-aliasing because we need to build |
842 | proper type representation for possible functions which are build with | |
e8444ca6 | 843 | -fstrict-aliasing. */ |
bd04cddf JH |
844 | |
845 | /* return 0 if this or its type is an error. */ | |
846 | if (t == error_mark_node | |
3bdf5ad1 RK |
847 | || (! TYPE_P (t) |
848 | && (TREE_TYPE (t) == 0 || TREE_TYPE (t) == error_mark_node))) | |
849 | return 0; | |
850 | ||
851 | /* We can be passed either an expression or a type. This and the | |
f47e9b4e RK |
852 | language-specific routine may make mutually-recursive calls to each other |
853 | to figure out what to do. At each juncture, we see if this is a tree | |
854 | that the language may need to handle specially. First handle things that | |
738cc472 | 855 | aren't types. */ |
f824e5c3 | 856 | if (! TYPE_P (t)) |
3bdf5ad1 | 857 | { |
70f34814 RG |
858 | /* Give the language a chance to do something with this tree |
859 | before we look at it. */ | |
8ac61af7 | 860 | STRIP_NOPS (t); |
ae2bcd98 | 861 | set = lang_hooks.get_alias_set (t); |
8ac61af7 RK |
862 | if (set != -1) |
863 | return set; | |
864 | ||
f40333af RB |
865 | /* Get the alias pointer-type to use or the outermost object |
866 | that we could have a pointer to. */ | |
867 | tree ptype = reference_alias_ptr_type_1 (&t); | |
868 | if (ptype != NULL) | |
869 | return get_deref_alias_set (ptype); | |
f824e5c3 | 870 | |
738cc472 RK |
871 | /* If we've already determined the alias set for a decl, just return |
872 | it. This is necessary for C++ anonymous unions, whose component | |
873 | variables don't look like union members (boo!). */ | |
8813a647 | 874 | if (VAR_P (t) |
3c0cb5de | 875 | && DECL_RTL_SET_P (t) && MEM_P (DECL_RTL (t))) |
5755cd38 JM |
876 | return MEM_ALIAS_SET (DECL_RTL (t)); |
877 | ||
f824e5c3 RK |
878 | /* Now all we care about is the type. */ |
879 | t = TREE_TYPE (t); | |
3bdf5ad1 RK |
880 | } |
881 | ||
3bdf5ad1 | 882 | /* Variant qualifiers don't affect the alias set, so get the main |
daad0278 | 883 | variant. */ |
3bdf5ad1 | 884 | t = TYPE_MAIN_VARIANT (t); |
daad0278 RG |
885 | |
886 | /* Always use the canonical type as well. If this is a type that | |
887 | requires structural comparisons to identify compatible types | |
888 | use alias set zero. */ | |
889 | if (TYPE_STRUCTURAL_EQUALITY_P (t)) | |
cb9c2485 JM |
890 | { |
891 | /* Allow the language to specify another alias set for this | |
892 | type. */ | |
893 | set = lang_hooks.get_alias_set (t); | |
894 | if (set != -1) | |
895 | return set; | |
aea50b45 JH |
896 | /* Handle structure type equality for pointer types, arrays and vectors. |
897 | This is easy to do, because the code bellow ignore canonical types on | |
898 | these anyway. This is important for LTO, where TYPE_CANONICAL for | |
899 | pointers can not be meaningfuly computed by the frotnend. */ | |
900 | if (canonical_type_used_p (t)) | |
f85d2487 JH |
901 | { |
902 | /* In LTO we set canonical types for all types where it makes | |
903 | sense to do so. Double check we did not miss some type. */ | |
904 | gcc_checking_assert (!in_lto_p || !type_with_alias_set_p (t)); | |
905 | return 0; | |
906 | } | |
907 | } | |
908 | else | |
909 | { | |
910 | t = TYPE_CANONICAL (t); | |
911 | gcc_checking_assert (!TYPE_STRUCTURAL_EQUALITY_P (t)); | |
cb9c2485 | 912 | } |
daad0278 RG |
913 | |
914 | /* If this is a type with a known alias set, return it. */ | |
ba6a6a1d | 915 | gcc_checking_assert (t == TYPE_MAIN_VARIANT (t)); |
738cc472 | 916 | if (TYPE_ALIAS_SET_KNOWN_P (t)) |
3bdf5ad1 RK |
917 | return TYPE_ALIAS_SET (t); |
918 | ||
36784d0e RG |
919 | /* We don't want to set TYPE_ALIAS_SET for incomplete types. */ |
920 | if (!COMPLETE_TYPE_P (t)) | |
921 | { | |
922 | /* For arrays with unknown size the conservative answer is the | |
923 | alias set of the element type. */ | |
924 | if (TREE_CODE (t) == ARRAY_TYPE) | |
925 | return get_alias_set (TREE_TYPE (t)); | |
926 | ||
927 | /* But return zero as a conservative answer for incomplete types. */ | |
928 | return 0; | |
929 | } | |
930 | ||
3bdf5ad1 | 931 | /* See if the language has special handling for this type. */ |
ae2bcd98 | 932 | set = lang_hooks.get_alias_set (t); |
8ac61af7 | 933 | if (set != -1) |
738cc472 | 934 | return set; |
2bf105ab | 935 | |
3bdf5ad1 RK |
936 | /* There are no objects of FUNCTION_TYPE, so there's no point in |
937 | using up an alias set for them. (There are, of course, pointers | |
938 | and references to functions, but that's different.) */ | |
7be7d292 | 939 | else if (TREE_CODE (t) == FUNCTION_TYPE || TREE_CODE (t) == METHOD_TYPE) |
3bdf5ad1 | 940 | set = 0; |
74d86f4f RH |
941 | |
942 | /* Unless the language specifies otherwise, let vector types alias | |
943 | their components. This avoids some nasty type punning issues in | |
944 | normal usage. And indeed lets vectors be treated more like an | |
945 | array slice. */ | |
946 | else if (TREE_CODE (t) == VECTOR_TYPE) | |
947 | set = get_alias_set (TREE_TYPE (t)); | |
948 | ||
4653cae5 RG |
949 | /* Unless the language specifies otherwise, treat array types the |
950 | same as their components. This avoids the asymmetry we get | |
951 | through recording the components. Consider accessing a | |
952 | character(kind=1) through a reference to a character(kind=1)[1:1]. | |
953 | Or consider if we want to assign integer(kind=4)[0:D.1387] and | |
954 | integer(kind=4)[4] the same alias set or not. | |
955 | Just be pragmatic here and make sure the array and its element | |
956 | type get the same alias set assigned. */ | |
aea50b45 JH |
957 | else if (TREE_CODE (t) == ARRAY_TYPE |
958 | && (!TYPE_NONALIASED_COMPONENT (t) | |
959 | || TYPE_STRUCTURAL_EQUALITY_P (t))) | |
4653cae5 RG |
960 | set = get_alias_set (TREE_TYPE (t)); |
961 | ||
0ceb0201 RG |
962 | /* From the former common C and C++ langhook implementation: |
963 | ||
964 | Unfortunately, there is no canonical form of a pointer type. | |
965 | In particular, if we have `typedef int I', then `int *', and | |
966 | `I *' are different types. So, we have to pick a canonical | |
967 | representative. We do this below. | |
968 | ||
969 | Technically, this approach is actually more conservative that | |
970 | it needs to be. In particular, `const int *' and `int *' | |
971 | should be in different alias sets, according to the C and C++ | |
972 | standard, since their types are not the same, and so, | |
973 | technically, an `int **' and `const int **' cannot point at | |
974 | the same thing. | |
975 | ||
976 | But, the standard is wrong. In particular, this code is | |
977 | legal C++: | |
978 | ||
979 | int *ip; | |
980 | int **ipp = &ip; | |
981 | const int* const* cipp = ipp; | |
982 | And, it doesn't make sense for that to be legal unless you | |
983 | can dereference IPP and CIPP. So, we ignore cv-qualifiers on | |
984 | the pointed-to types. This issue has been reported to the | |
985 | C++ committee. | |
986 | ||
6e042ef4 JH |
987 | For this reason go to canonical type of the unqalified pointer type. |
988 | Until GCC 6 this code set all pointers sets to have alias set of | |
989 | ptr_type_node but that is a bad idea, because it prevents disabiguations | |
990 | in between pointers. For Firefox this accounts about 20% of all | |
991 | disambiguations in the program. */ | |
f85d2487 | 992 | else if (POINTER_TYPE_P (t) && t != ptr_type_node) |
6e042ef4 JH |
993 | { |
994 | tree p; | |
995 | auto_vec <bool, 8> reference; | |
996 | ||
997 | /* Unnest all pointers and references. | |
f85d2487 JH |
998 | We also want to make pointer to array/vector equivalent to pointer to |
999 | its element (see the reasoning above). Skip all those types, too. */ | |
6e042ef4 | 1000 | for (p = t; POINTER_TYPE_P (p) |
aea50b45 JH |
1001 | || (TREE_CODE (p) == ARRAY_TYPE |
1002 | && (!TYPE_NONALIASED_COMPONENT (p) | |
1003 | || !COMPLETE_TYPE_P (p) | |
1004 | || TYPE_STRUCTURAL_EQUALITY_P (p))) | |
f85d2487 | 1005 | || TREE_CODE (p) == VECTOR_TYPE; |
6e042ef4 JH |
1006 | p = TREE_TYPE (p)) |
1007 | { | |
54363f8a JH |
1008 | /* Ada supports recusive pointers. Instead of doing recrusion check |
1009 | just give up once the preallocated space of 8 elements is up. | |
1010 | In this case just punt to void * alias set. */ | |
1011 | if (reference.length () == 8) | |
1012 | { | |
1013 | p = ptr_type_node; | |
1014 | break; | |
1015 | } | |
6e042ef4 | 1016 | if (TREE_CODE (p) == REFERENCE_TYPE) |
f85d2487 JH |
1017 | /* In LTO we want languages that use references to be compatible |
1018 | with languages that use pointers. */ | |
1019 | reference.safe_push (true && !in_lto_p); | |
6e042ef4 JH |
1020 | if (TREE_CODE (p) == POINTER_TYPE) |
1021 | reference.safe_push (false); | |
1022 | } | |
1023 | p = TYPE_MAIN_VARIANT (p); | |
1024 | ||
1025 | /* Make void * compatible with char * and also void **. | |
1026 | Programs are commonly violating TBAA by this. | |
1027 | ||
1028 | We also make void * to conflict with every pointer | |
1029 | (see record_component_aliases) and thus it is safe it to use it for | |
1030 | pointers to types with TYPE_STRUCTURAL_EQUALITY_P. */ | |
1031 | if (TREE_CODE (p) == VOID_TYPE || TYPE_STRUCTURAL_EQUALITY_P (p)) | |
1032 | set = get_alias_set (ptr_type_node); | |
1033 | else | |
1034 | { | |
f85d2487 | 1035 | /* Rebuild pointer type starting from canonical types using |
6e042ef4 JH |
1036 | unqualified pointers and references only. This way all such |
1037 | pointers will have the same alias set and will conflict with | |
1038 | each other. | |
1039 | ||
1040 | Most of time we already have pointers or references of a given type. | |
1041 | If not we build new one just to be sure that if someone later | |
1042 | (probably only middle-end can, as we should assign all alias | |
1043 | classes only after finishing translation unit) builds the pointer | |
1044 | type, the canonical type will match. */ | |
1045 | p = TYPE_CANONICAL (p); | |
1046 | while (!reference.is_empty ()) | |
1047 | { | |
1048 | if (reference.pop ()) | |
1049 | p = build_reference_type (p); | |
1050 | else | |
1051 | p = build_pointer_type (p); | |
f85d2487 JH |
1052 | gcc_checking_assert (p == TYPE_MAIN_VARIANT (p)); |
1053 | /* build_pointer_type should always return the canonical type. | |
1054 | For LTO TYPE_CANOINCAL may be NULL, because we do not compute | |
1055 | them. Be sure that frontends do not glob canonical types of | |
1056 | pointers in unexpected way and that p == TYPE_CANONICAL (p) | |
1057 | in all other cases. */ | |
1058 | gcc_checking_assert (!TYPE_CANONICAL (p) | |
1059 | || p == TYPE_CANONICAL (p)); | |
6e042ef4 | 1060 | } |
6e042ef4 JH |
1061 | |
1062 | /* Assign the alias set to both p and t. | |
1063 | We can not call get_alias_set (p) here as that would trigger | |
1064 | infinite recursion when p == t. In other cases it would just | |
1065 | trigger unnecesary legwork of rebuilding the pointer again. */ | |
ba6a6a1d | 1066 | gcc_checking_assert (p == TYPE_MAIN_VARIANT (p)); |
6e042ef4 JH |
1067 | if (TYPE_ALIAS_SET_KNOWN_P (p)) |
1068 | set = TYPE_ALIAS_SET (p); | |
1069 | else | |
1070 | { | |
1071 | set = new_alias_set (); | |
1072 | TYPE_ALIAS_SET (p) = set; | |
1073 | } | |
1074 | } | |
1075 | } | |
f85d2487 JH |
1076 | /* Alias set of ptr_type_node is special and serve as universal pointer which |
1077 | is TBAA compatible with every other pointer type. Be sure we have the | |
1078 | alias set built even for LTO which otherwise keeps all TYPE_CANONICAL | |
1079 | of pointer types NULL. */ | |
1080 | else if (t == ptr_type_node) | |
1081 | set = new_alias_set (); | |
0ceb0201 | 1082 | |
7be7d292 | 1083 | /* Otherwise make a new alias set for this type. */ |
3bdf5ad1 | 1084 | else |
96d91dcf RG |
1085 | { |
1086 | /* Each canonical type gets its own alias set, so canonical types | |
1087 | shouldn't form a tree. It doesn't really matter for types | |
1088 | we handle specially above, so only check it where it possibly | |
1089 | would result in a bogus alias set. */ | |
1090 | gcc_checking_assert (TYPE_CANONICAL (t) == t); | |
1091 | ||
1092 | set = new_alias_set (); | |
1093 | } | |
3bdf5ad1 RK |
1094 | |
1095 | TYPE_ALIAS_SET (t) = set; | |
2bf105ab | 1096 | |
7be7d292 EB |
1097 | /* If this is an aggregate type or a complex type, we must record any |
1098 | component aliasing information. */ | |
1d79fd2c | 1099 | if (AGGREGATE_TYPE_P (t) || TREE_CODE (t) == COMPLEX_TYPE) |
2bf105ab RK |
1100 | record_component_aliases (t); |
1101 | ||
6e042ef4 JH |
1102 | /* We treat pointer types specially in alias_set_subset_of. */ |
1103 | if (POINTER_TYPE_P (t) && set) | |
1104 | { | |
02ced957 | 1105 | alias_set_entry *ase = get_alias_set_entry (set); |
6e042ef4 JH |
1106 | if (!ase) |
1107 | ase = init_alias_set_entry (set); | |
1108 | ase->is_pointer = true; | |
1109 | ase->has_pointer = true; | |
1110 | } | |
1111 | ||
3bdf5ad1 RK |
1112 | return set; |
1113 | } | |
1114 | ||
1115 | /* Return a brand-new alias set. */ | |
1116 | ||
4862826d | 1117 | alias_set_type |
4682ae04 | 1118 | new_alias_set (void) |
3bdf5ad1 | 1119 | { |
bd04cddf JH |
1120 | if (alias_sets == 0) |
1121 | vec_safe_push (alias_sets, (alias_set_entry *) NULL); | |
1122 | vec_safe_push (alias_sets, (alias_set_entry *) NULL); | |
1123 | return alias_sets->length () - 1; | |
3bdf5ad1 | 1124 | } |
3932261a | 1125 | |
01d28c3f JM |
1126 | /* Indicate that things in SUBSET can alias things in SUPERSET, but that |
1127 | not everything that aliases SUPERSET also aliases SUBSET. For example, | |
1128 | in C, a store to an `int' can alias a load of a structure containing an | |
1129 | `int', and vice versa. But it can't alias a load of a 'double' member | |
1130 | of the same structure. Here, the structure would be the SUPERSET and | |
1131 | `int' the SUBSET. This relationship is also described in the comment at | |
1132 | the beginning of this file. | |
1133 | ||
1134 | This function should be called only once per SUPERSET/SUBSET pair. | |
3932261a MM |
1135 | |
1136 | It is illegal for SUPERSET to be zero; everything is implicitly a | |
1137 | subset of alias set zero. */ | |
1138 | ||
794511d2 | 1139 | void |
4862826d | 1140 | record_alias_subset (alias_set_type superset, alias_set_type subset) |
3932261a | 1141 | { |
02ced957 TS |
1142 | alias_set_entry *superset_entry; |
1143 | alias_set_entry *subset_entry; | |
3932261a | 1144 | |
f47e9b4e RK |
1145 | /* It is possible in complex type situations for both sets to be the same, |
1146 | in which case we can ignore this operation. */ | |
1147 | if (superset == subset) | |
1148 | return; | |
1149 | ||
298e6adc | 1150 | gcc_assert (superset); |
3932261a MM |
1151 | |
1152 | superset_entry = get_alias_set_entry (superset); | |
ca7fd9cd | 1153 | if (superset_entry == 0) |
3932261a MM |
1154 | { |
1155 | /* Create an entry for the SUPERSET, so that we have a place to | |
1156 | attach the SUBSET. */ | |
6e042ef4 | 1157 | superset_entry = init_alias_set_entry (superset); |
3932261a MM |
1158 | } |
1159 | ||
2bf105ab RK |
1160 | if (subset == 0) |
1161 | superset_entry->has_zero_child = 1; | |
1162 | else | |
1163 | { | |
1164 | subset_entry = get_alias_set_entry (subset); | |
6e042ef4 JH |
1165 | if (!superset_entry->children) |
1166 | superset_entry->children | |
fb5c464a | 1167 | = hash_map<alias_set_hash, int>::create_ggc (64); |
2bf105ab RK |
1168 | /* If there is an entry for the subset, enter all of its children |
1169 | (if they are not already present) as children of the SUPERSET. */ | |
ca7fd9cd | 1170 | if (subset_entry) |
2bf105ab RK |
1171 | { |
1172 | if (subset_entry->has_zero_child) | |
6e042ef4 JH |
1173 | superset_entry->has_zero_child = true; |
1174 | if (subset_entry->has_pointer) | |
1175 | superset_entry->has_pointer = true; | |
d4b60170 | 1176 | |
6e042ef4 JH |
1177 | if (subset_entry->children) |
1178 | { | |
fb5c464a | 1179 | hash_map<alias_set_hash, int>::iterator iter |
6e042ef4 JH |
1180 | = subset_entry->children->begin (); |
1181 | for (; iter != subset_entry->children->end (); ++iter) | |
1182 | superset_entry->children->put ((*iter).first, (*iter).second); | |
1183 | } | |
2bf105ab | 1184 | } |
3932261a | 1185 | |
2bf105ab | 1186 | /* Enter the SUBSET itself as a child of the SUPERSET. */ |
de144fb2 | 1187 | superset_entry->children->put (subset, 0); |
2bf105ab | 1188 | } |
3932261a MM |
1189 | } |
1190 | ||
a0c33338 RK |
1191 | /* Record that component types of TYPE, if any, are part of that type for |
1192 | aliasing purposes. For record types, we only record component types | |
b5487346 EB |
1193 | for fields that are not marked non-addressable. For array types, we |
1194 | only record the component type if it is not marked non-aliased. */ | |
a0c33338 RK |
1195 | |
1196 | void | |
4682ae04 | 1197 | record_component_aliases (tree type) |
a0c33338 | 1198 | { |
4862826d | 1199 | alias_set_type superset = get_alias_set (type); |
a0c33338 RK |
1200 | tree field; |
1201 | ||
1202 | if (superset == 0) | |
1203 | return; | |
1204 | ||
1205 | switch (TREE_CODE (type)) | |
1206 | { | |
a0c33338 RK |
1207 | case RECORD_TYPE: |
1208 | case UNION_TYPE: | |
1209 | case QUAL_UNION_TYPE: | |
910ad8de | 1210 | for (field = TYPE_FIELDS (type); field != 0; field = DECL_CHAIN (field)) |
b5487346 | 1211 | if (TREE_CODE (field) == FIELD_DECL && !DECL_NONADDRESSABLE_P (field)) |
f85d2487 JH |
1212 | { |
1213 | /* LTO type merging does not make any difference between | |
1214 | component pointer types. We may have | |
1215 | ||
1216 | struct foo {int *a;}; | |
1217 | ||
1218 | as TYPE_CANONICAL of | |
1219 | ||
1220 | struct bar {float *a;}; | |
1221 | ||
1222 | Because accesses to int * and float * do not alias, we would get | |
1223 | false negative when accessing the same memory location by | |
1224 | float ** and bar *. We thus record the canonical type as: | |
1225 | ||
1226 | struct {void *a;}; | |
1227 | ||
1228 | void * is special cased and works as a universal pointer type. | |
1229 | Accesses to it conflicts with accesses to any other pointer | |
1230 | type. */ | |
1231 | tree t = TREE_TYPE (field); | |
1232 | if (in_lto_p) | |
1233 | { | |
1234 | /* VECTOR_TYPE and ARRAY_TYPE share the alias set with their | |
1235 | element type and that type has to be normalized to void *, | |
1236 | too, in the case it is a pointer. */ | |
aea50b45 JH |
1237 | while (!canonical_type_used_p (t) && !POINTER_TYPE_P (t)) |
1238 | { | |
1239 | gcc_checking_assert (TYPE_STRUCTURAL_EQUALITY_P (t)); | |
1240 | t = TREE_TYPE (t); | |
1241 | } | |
f85d2487 JH |
1242 | if (POINTER_TYPE_P (t)) |
1243 | t = ptr_type_node; | |
aea50b45 JH |
1244 | else if (flag_checking) |
1245 | gcc_checking_assert (get_alias_set (t) | |
1246 | == get_alias_set (TREE_TYPE (field))); | |
f85d2487 | 1247 | } |
aea50b45 | 1248 | |
f85d2487 JH |
1249 | record_alias_subset (superset, get_alias_set (t)); |
1250 | } | |
a0c33338 RK |
1251 | break; |
1252 | ||
1d79fd2c JW |
1253 | case COMPLEX_TYPE: |
1254 | record_alias_subset (superset, get_alias_set (TREE_TYPE (type))); | |
1255 | break; | |
1256 | ||
4653cae5 RG |
1257 | /* VECTOR_TYPE and ARRAY_TYPE share the alias set with their |
1258 | element type. */ | |
1259 | ||
a0c33338 RK |
1260 | default: |
1261 | break; | |
1262 | } | |
1263 | } | |
1264 | ||
3bdf5ad1 RK |
1265 | /* Allocate an alias set for use in storing and reading from the varargs |
1266 | spill area. */ | |
1267 | ||
4862826d | 1268 | static GTY(()) alias_set_type varargs_set = -1; |
f103e34d | 1269 | |
4862826d | 1270 | alias_set_type |
4682ae04 | 1271 | get_varargs_alias_set (void) |
3bdf5ad1 | 1272 | { |
cd3ce9b4 JM |
1273 | #if 1 |
1274 | /* We now lower VA_ARG_EXPR, and there's currently no way to attach the | |
1275 | varargs alias set to an INDIRECT_REF (FIXME!), so we can't | |
1276 | consistently use the varargs alias set for loads from the varargs | |
1277 | area. So don't use it anywhere. */ | |
1278 | return 0; | |
1279 | #else | |
f103e34d GK |
1280 | if (varargs_set == -1) |
1281 | varargs_set = new_alias_set (); | |
3bdf5ad1 | 1282 | |
f103e34d | 1283 | return varargs_set; |
cd3ce9b4 | 1284 | #endif |
3bdf5ad1 RK |
1285 | } |
1286 | ||
1287 | /* Likewise, but used for the fixed portions of the frame, e.g., register | |
1288 | save areas. */ | |
1289 | ||
4862826d | 1290 | static GTY(()) alias_set_type frame_set = -1; |
f103e34d | 1291 | |
4862826d | 1292 | alias_set_type |
4682ae04 | 1293 | get_frame_alias_set (void) |
3bdf5ad1 | 1294 | { |
f103e34d GK |
1295 | if (frame_set == -1) |
1296 | frame_set = new_alias_set (); | |
3bdf5ad1 | 1297 | |
f103e34d | 1298 | return frame_set; |
3bdf5ad1 RK |
1299 | } |
1300 | ||
9fc37b2b RS |
1301 | /* Create a new, unique base with id ID. */ |
1302 | ||
1303 | static rtx | |
1304 | unique_base_value (HOST_WIDE_INT id) | |
1305 | { | |
1306 | return gen_rtx_ADDRESS (Pmode, id); | |
1307 | } | |
1308 | ||
1309 | /* Return true if accesses based on any other base value cannot alias | |
1310 | those based on X. */ | |
1311 | ||
1312 | static bool | |
1313 | unique_base_value_p (rtx x) | |
1314 | { | |
1315 | return GET_CODE (x) == ADDRESS && GET_MODE (x) == Pmode; | |
1316 | } | |
1317 | ||
1318 | /* Return true if X is known to be a base value. */ | |
1319 | ||
1320 | static bool | |
1321 | known_base_value_p (rtx x) | |
1322 | { | |
1323 | switch (GET_CODE (x)) | |
1324 | { | |
1325 | case LABEL_REF: | |
1326 | case SYMBOL_REF: | |
1327 | return true; | |
1328 | ||
1329 | case ADDRESS: | |
1330 | /* Arguments may or may not be bases; we don't know for sure. */ | |
1331 | return GET_MODE (x) != VOIDmode; | |
1332 | ||
1333 | default: | |
1334 | return false; | |
1335 | } | |
1336 | } | |
1337 | ||
2a2c8203 JC |
1338 | /* Inside SRC, the source of a SET, find a base address. */ |
1339 | ||
9ae8ffe7 | 1340 | static rtx |
4682ae04 | 1341 | find_base_value (rtx src) |
9ae8ffe7 | 1342 | { |
713f41f9 | 1343 | unsigned int regno; |
0aacc8ed | 1344 | |
53451050 RS |
1345 | #if defined (FIND_BASE_TERM) |
1346 | /* Try machine-dependent ways to find the base term. */ | |
1347 | src = FIND_BASE_TERM (src); | |
1348 | #endif | |
1349 | ||
9ae8ffe7 JL |
1350 | switch (GET_CODE (src)) |
1351 | { | |
1352 | case SYMBOL_REF: | |
1353 | case LABEL_REF: | |
1354 | return src; | |
1355 | ||
1356 | case REG: | |
fb6754f0 | 1357 | regno = REGNO (src); |
d4b60170 | 1358 | /* At the start of a function, argument registers have known base |
2a2c8203 JC |
1359 | values which may be lost later. Returning an ADDRESS |
1360 | expression here allows optimization based on argument values | |
1361 | even when the argument registers are used for other purposes. */ | |
713f41f9 BS |
1362 | if (regno < FIRST_PSEUDO_REGISTER && copying_arguments) |
1363 | return new_reg_base_value[regno]; | |
73774bc7 | 1364 | |
eaf407a5 | 1365 | /* If a pseudo has a known base value, return it. Do not do this |
9b462c42 RH |
1366 | for non-fixed hard regs since it can result in a circular |
1367 | dependency chain for registers which have values at function entry. | |
eaf407a5 JL |
1368 | |
1369 | The test above is not sufficient because the scheduler may move | |
1370 | a copy out of an arg reg past the NOTE_INSN_FUNCTION_BEGIN. */ | |
9b462c42 | 1371 | if ((regno >= FIRST_PSEUDO_REGISTER || fixed_regs[regno]) |
9771b263 | 1372 | && regno < vec_safe_length (reg_base_value)) |
83bbd9b6 RH |
1373 | { |
1374 | /* If we're inside init_alias_analysis, use new_reg_base_value | |
1375 | to reduce the number of relaxation iterations. */ | |
1afdf91c | 1376 | if (new_reg_base_value && new_reg_base_value[regno] |
6fb5fa3c | 1377 | && DF_REG_DEF_COUNT (regno) == 1) |
83bbd9b6 RH |
1378 | return new_reg_base_value[regno]; |
1379 | ||
9771b263 DN |
1380 | if ((*reg_base_value)[regno]) |
1381 | return (*reg_base_value)[regno]; | |
83bbd9b6 | 1382 | } |
73774bc7 | 1383 | |
e3f049a8 | 1384 | return 0; |
9ae8ffe7 JL |
1385 | |
1386 | case MEM: | |
1387 | /* Check for an argument passed in memory. Only record in the | |
1388 | copying-arguments block; it is too hard to track changes | |
1389 | otherwise. */ | |
1390 | if (copying_arguments | |
1391 | && (XEXP (src, 0) == arg_pointer_rtx | |
1392 | || (GET_CODE (XEXP (src, 0)) == PLUS | |
1393 | && XEXP (XEXP (src, 0), 0) == arg_pointer_rtx))) | |
9fc37b2b | 1394 | return arg_base_value; |
9ae8ffe7 JL |
1395 | return 0; |
1396 | ||
1397 | case CONST: | |
1398 | src = XEXP (src, 0); | |
1399 | if (GET_CODE (src) != PLUS && GET_CODE (src) != MINUS) | |
1400 | break; | |
d4b60170 | 1401 | |
191816a3 | 1402 | /* fall through */ |
2a2c8203 | 1403 | |
9ae8ffe7 JL |
1404 | case PLUS: |
1405 | case MINUS: | |
2a2c8203 | 1406 | { |
ec907dd8 JL |
1407 | rtx temp, src_0 = XEXP (src, 0), src_1 = XEXP (src, 1); |
1408 | ||
0134bf2d DE |
1409 | /* If either operand is a REG that is a known pointer, then it |
1410 | is the base. */ | |
1411 | if (REG_P (src_0) && REG_POINTER (src_0)) | |
1412 | return find_base_value (src_0); | |
1413 | if (REG_P (src_1) && REG_POINTER (src_1)) | |
1414 | return find_base_value (src_1); | |
1415 | ||
ec907dd8 JL |
1416 | /* If either operand is a REG, then see if we already have |
1417 | a known value for it. */ | |
0134bf2d | 1418 | if (REG_P (src_0)) |
ec907dd8 JL |
1419 | { |
1420 | temp = find_base_value (src_0); | |
d4b60170 | 1421 | if (temp != 0) |
ec907dd8 JL |
1422 | src_0 = temp; |
1423 | } | |
1424 | ||
0134bf2d | 1425 | if (REG_P (src_1)) |
ec907dd8 JL |
1426 | { |
1427 | temp = find_base_value (src_1); | |
d4b60170 | 1428 | if (temp!= 0) |
ec907dd8 JL |
1429 | src_1 = temp; |
1430 | } | |
2a2c8203 | 1431 | |
0134bf2d DE |
1432 | /* If either base is named object or a special address |
1433 | (like an argument or stack reference), then use it for the | |
1434 | base term. */ | |
9fc37b2b | 1435 | if (src_0 != 0 && known_base_value_p (src_0)) |
0134bf2d DE |
1436 | return src_0; |
1437 | ||
9fc37b2b | 1438 | if (src_1 != 0 && known_base_value_p (src_1)) |
0134bf2d DE |
1439 | return src_1; |
1440 | ||
d4b60170 | 1441 | /* Guess which operand is the base address: |
ec907dd8 JL |
1442 | If either operand is a symbol, then it is the base. If |
1443 | either operand is a CONST_INT, then the other is the base. */ | |
481683e1 | 1444 | if (CONST_INT_P (src_1) || CONSTANT_P (src_0)) |
2a2c8203 | 1445 | return find_base_value (src_0); |
481683e1 | 1446 | else if (CONST_INT_P (src_0) || CONSTANT_P (src_1)) |
ec907dd8 JL |
1447 | return find_base_value (src_1); |
1448 | ||
9ae8ffe7 | 1449 | return 0; |
2a2c8203 JC |
1450 | } |
1451 | ||
1452 | case LO_SUM: | |
1453 | /* The standard form is (lo_sum reg sym) so look only at the | |
1454 | second operand. */ | |
1455 | return find_base_value (XEXP (src, 1)); | |
9ae8ffe7 JL |
1456 | |
1457 | case AND: | |
1458 | /* If the second operand is constant set the base | |
ec5c56db | 1459 | address to the first operand. */ |
481683e1 | 1460 | if (CONST_INT_P (XEXP (src, 1)) && INTVAL (XEXP (src, 1)) != 0) |
2a2c8203 | 1461 | return find_base_value (XEXP (src, 0)); |
9ae8ffe7 JL |
1462 | return 0; |
1463 | ||
61f0131c | 1464 | case TRUNCATE: |
5932a4d4 | 1465 | /* As we do not know which address space the pointer is referring to, we can |
d4ebfa65 BE |
1466 | handle this only if the target does not support different pointer or |
1467 | address modes depending on the address space. */ | |
1468 | if (!target_default_pointer_address_modes_p ()) | |
1469 | break; | |
61f0131c R |
1470 | if (GET_MODE_SIZE (GET_MODE (src)) < GET_MODE_SIZE (Pmode)) |
1471 | break; | |
1472 | /* Fall through. */ | |
9ae8ffe7 | 1473 | case HIGH: |
d288e53d DE |
1474 | case PRE_INC: |
1475 | case PRE_DEC: | |
1476 | case POST_INC: | |
1477 | case POST_DEC: | |
1478 | case PRE_MODIFY: | |
1479 | case POST_MODIFY: | |
2a2c8203 | 1480 | return find_base_value (XEXP (src, 0)); |
1d300e19 | 1481 | |
0aacc8ed RK |
1482 | case ZERO_EXTEND: |
1483 | case SIGN_EXTEND: /* used for NT/Alpha pointers */ | |
5932a4d4 | 1484 | /* As we do not know which address space the pointer is referring to, we can |
d4ebfa65 BE |
1485 | handle this only if the target does not support different pointer or |
1486 | address modes depending on the address space. */ | |
1487 | if (!target_default_pointer_address_modes_p ()) | |
1488 | break; | |
1489 | ||
0aacc8ed RK |
1490 | { |
1491 | rtx temp = find_base_value (XEXP (src, 0)); | |
1492 | ||
5ae6cd0d | 1493 | if (temp != 0 && CONSTANT_P (temp)) |
0aacc8ed | 1494 | temp = convert_memory_address (Pmode, temp); |
0aacc8ed RK |
1495 | |
1496 | return temp; | |
1497 | } | |
1498 | ||
1d300e19 KG |
1499 | default: |
1500 | break; | |
9ae8ffe7 JL |
1501 | } |
1502 | ||
1503 | return 0; | |
1504 | } | |
1505 | ||
9fc37b2b RS |
1506 | /* Called from init_alias_analysis indirectly through note_stores, |
1507 | or directly if DEST is a register with a REG_NOALIAS note attached. | |
1508 | SET is null in the latter case. */ | |
9ae8ffe7 | 1509 | |
d4b60170 | 1510 | /* While scanning insns to find base values, reg_seen[N] is nonzero if |
9ae8ffe7 | 1511 | register N has been set in this function. */ |
d630245f | 1512 | static sbitmap reg_seen; |
9ae8ffe7 | 1513 | |
2a2c8203 | 1514 | static void |
7bc980e1 | 1515 | record_set (rtx dest, const_rtx set, void *data ATTRIBUTE_UNUSED) |
9ae8ffe7 | 1516 | { |
b3694847 | 1517 | unsigned regno; |
9ae8ffe7 | 1518 | rtx src; |
c28b4e40 | 1519 | int n; |
9ae8ffe7 | 1520 | |
f8cfc6aa | 1521 | if (!REG_P (dest)) |
9ae8ffe7 JL |
1522 | return; |
1523 | ||
fb6754f0 | 1524 | regno = REGNO (dest); |
9ae8ffe7 | 1525 | |
9771b263 | 1526 | gcc_checking_assert (regno < reg_base_value->length ()); |
ac606739 | 1527 | |
dc8afb70 | 1528 | n = REG_NREGS (dest); |
c28b4e40 JW |
1529 | if (n != 1) |
1530 | { | |
1531 | while (--n >= 0) | |
1532 | { | |
d7c028c0 | 1533 | bitmap_set_bit (reg_seen, regno + n); |
c28b4e40 JW |
1534 | new_reg_base_value[regno + n] = 0; |
1535 | } | |
1536 | return; | |
1537 | } | |
1538 | ||
9ae8ffe7 JL |
1539 | if (set) |
1540 | { | |
1541 | /* A CLOBBER wipes out any old value but does not prevent a previously | |
1542 | unset register from acquiring a base address (i.e. reg_seen is not | |
1543 | set). */ | |
1544 | if (GET_CODE (set) == CLOBBER) | |
1545 | { | |
ec907dd8 | 1546 | new_reg_base_value[regno] = 0; |
9ae8ffe7 JL |
1547 | return; |
1548 | } | |
1549 | src = SET_SRC (set); | |
1550 | } | |
1551 | else | |
1552 | { | |
9fc37b2b | 1553 | /* There's a REG_NOALIAS note against DEST. */ |
d7c028c0 | 1554 | if (bitmap_bit_p (reg_seen, regno)) |
9ae8ffe7 | 1555 | { |
ec907dd8 | 1556 | new_reg_base_value[regno] = 0; |
9ae8ffe7 JL |
1557 | return; |
1558 | } | |
d7c028c0 | 1559 | bitmap_set_bit (reg_seen, regno); |
9fc37b2b | 1560 | new_reg_base_value[regno] = unique_base_value (unique_id++); |
9ae8ffe7 JL |
1561 | return; |
1562 | } | |
1563 | ||
5da6f168 RS |
1564 | /* If this is not the first set of REGNO, see whether the new value |
1565 | is related to the old one. There are two cases of interest: | |
1566 | ||
1567 | (1) The register might be assigned an entirely new value | |
1568 | that has the same base term as the original set. | |
1569 | ||
1570 | (2) The set might be a simple self-modification that | |
1571 | cannot change REGNO's base value. | |
1572 | ||
1573 | If neither case holds, reject the original base value as invalid. | |
1574 | Note that the following situation is not detected: | |
1575 | ||
c22cacf3 | 1576 | extern int x, y; int *p = &x; p += (&y-&x); |
5da6f168 | 1577 | |
9ae8ffe7 JL |
1578 | ANSI C does not allow computing the difference of addresses |
1579 | of distinct top level objects. */ | |
5da6f168 RS |
1580 | if (new_reg_base_value[regno] != 0 |
1581 | && find_base_value (src) != new_reg_base_value[regno]) | |
9ae8ffe7 JL |
1582 | switch (GET_CODE (src)) |
1583 | { | |
2a2c8203 | 1584 | case LO_SUM: |
9ae8ffe7 JL |
1585 | case MINUS: |
1586 | if (XEXP (src, 0) != dest && XEXP (src, 1) != dest) | |
ec907dd8 | 1587 | new_reg_base_value[regno] = 0; |
9ae8ffe7 | 1588 | break; |
61f0131c R |
1589 | case PLUS: |
1590 | /* If the value we add in the PLUS is also a valid base value, | |
1591 | this might be the actual base value, and the original value | |
1592 | an index. */ | |
1593 | { | |
1594 | rtx other = NULL_RTX; | |
1595 | ||
1596 | if (XEXP (src, 0) == dest) | |
1597 | other = XEXP (src, 1); | |
1598 | else if (XEXP (src, 1) == dest) | |
1599 | other = XEXP (src, 0); | |
1600 | ||
1601 | if (! other || find_base_value (other)) | |
1602 | new_reg_base_value[regno] = 0; | |
1603 | break; | |
1604 | } | |
9ae8ffe7 | 1605 | case AND: |
481683e1 | 1606 | if (XEXP (src, 0) != dest || !CONST_INT_P (XEXP (src, 1))) |
ec907dd8 | 1607 | new_reg_base_value[regno] = 0; |
9ae8ffe7 | 1608 | break; |
9ae8ffe7 | 1609 | default: |
ec907dd8 | 1610 | new_reg_base_value[regno] = 0; |
9ae8ffe7 JL |
1611 | break; |
1612 | } | |
1613 | /* If this is the first set of a register, record the value. */ | |
1614 | else if ((regno >= FIRST_PSEUDO_REGISTER || ! fixed_regs[regno]) | |
d7c028c0 | 1615 | && ! bitmap_bit_p (reg_seen, regno) && new_reg_base_value[regno] == 0) |
ec907dd8 | 1616 | new_reg_base_value[regno] = find_base_value (src); |
9ae8ffe7 | 1617 | |
d7c028c0 | 1618 | bitmap_set_bit (reg_seen, regno); |
9ae8ffe7 JL |
1619 | } |
1620 | ||
8fd0a474 AM |
1621 | /* Return REG_BASE_VALUE for REGNO. Selective scheduler uses this to avoid |
1622 | using hard registers with non-null REG_BASE_VALUE for renaming. */ | |
1623 | rtx | |
1624 | get_reg_base_value (unsigned int regno) | |
1625 | { | |
9771b263 | 1626 | return (*reg_base_value)[regno]; |
8fd0a474 AM |
1627 | } |
1628 | ||
bb1acb3e RH |
1629 | /* If a value is known for REGNO, return it. */ |
1630 | ||
c22cacf3 | 1631 | rtx |
bb1acb3e RH |
1632 | get_reg_known_value (unsigned int regno) |
1633 | { | |
1634 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1635 | { | |
1636 | regno -= FIRST_PSEUDO_REGISTER; | |
9771b263 DN |
1637 | if (regno < vec_safe_length (reg_known_value)) |
1638 | return (*reg_known_value)[regno]; | |
bb1acb3e RH |
1639 | } |
1640 | return NULL; | |
43fe47ca JW |
1641 | } |
1642 | ||
bb1acb3e RH |
1643 | /* Set it. */ |
1644 | ||
1645 | static void | |
1646 | set_reg_known_value (unsigned int regno, rtx val) | |
1647 | { | |
1648 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1649 | { | |
1650 | regno -= FIRST_PSEUDO_REGISTER; | |
9771b263 DN |
1651 | if (regno < vec_safe_length (reg_known_value)) |
1652 | (*reg_known_value)[regno] = val; | |
bb1acb3e RH |
1653 | } |
1654 | } | |
1655 | ||
1656 | /* Similarly for reg_known_equiv_p. */ | |
1657 | ||
1658 | bool | |
1659 | get_reg_known_equiv_p (unsigned int regno) | |
1660 | { | |
1661 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1662 | { | |
1663 | regno -= FIRST_PSEUDO_REGISTER; | |
9771b263 | 1664 | if (regno < vec_safe_length (reg_known_value)) |
d7c028c0 | 1665 | return bitmap_bit_p (reg_known_equiv_p, regno); |
bb1acb3e RH |
1666 | } |
1667 | return false; | |
1668 | } | |
1669 | ||
1670 | static void | |
1671 | set_reg_known_equiv_p (unsigned int regno, bool val) | |
1672 | { | |
1673 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1674 | { | |
1675 | regno -= FIRST_PSEUDO_REGISTER; | |
9771b263 | 1676 | if (regno < vec_safe_length (reg_known_value)) |
9ff3c7ca SB |
1677 | { |
1678 | if (val) | |
d7c028c0 | 1679 | bitmap_set_bit (reg_known_equiv_p, regno); |
9ff3c7ca | 1680 | else |
d7c028c0 | 1681 | bitmap_clear_bit (reg_known_equiv_p, regno); |
9ff3c7ca | 1682 | } |
bb1acb3e RH |
1683 | } |
1684 | } | |
1685 | ||
1686 | ||
db048faf MM |
1687 | /* Returns a canonical version of X, from the point of view alias |
1688 | analysis. (For example, if X is a MEM whose address is a register, | |
1689 | and the register has a known value (say a SYMBOL_REF), then a MEM | |
1690 | whose address is the SYMBOL_REF is returned.) */ | |
1691 | ||
1692 | rtx | |
4682ae04 | 1693 | canon_rtx (rtx x) |
9ae8ffe7 JL |
1694 | { |
1695 | /* Recursively look for equivalences. */ | |
f8cfc6aa | 1696 | if (REG_P (x) && REGNO (x) >= FIRST_PSEUDO_REGISTER) |
bb1acb3e RH |
1697 | { |
1698 | rtx t = get_reg_known_value (REGNO (x)); | |
1699 | if (t == x) | |
1700 | return x; | |
1701 | if (t) | |
1702 | return canon_rtx (t); | |
1703 | } | |
1704 | ||
1705 | if (GET_CODE (x) == PLUS) | |
9ae8ffe7 JL |
1706 | { |
1707 | rtx x0 = canon_rtx (XEXP (x, 0)); | |
1708 | rtx x1 = canon_rtx (XEXP (x, 1)); | |
1709 | ||
1710 | if (x0 != XEXP (x, 0) || x1 != XEXP (x, 1)) | |
231314e3 | 1711 | return simplify_gen_binary (PLUS, GET_MODE (x), x0, x1); |
9ae8ffe7 | 1712 | } |
d4b60170 | 1713 | |
9ae8ffe7 JL |
1714 | /* This gives us much better alias analysis when called from |
1715 | the loop optimizer. Note we want to leave the original | |
1716 | MEM alone, but need to return the canonicalized MEM with | |
1717 | all the flags with their original values. */ | |
3c0cb5de | 1718 | else if (MEM_P (x)) |
f1ec5147 | 1719 | x = replace_equiv_address_nv (x, canon_rtx (XEXP (x, 0))); |
d4b60170 | 1720 | |
9ae8ffe7 JL |
1721 | return x; |
1722 | } | |
1723 | ||
1724 | /* Return 1 if X and Y are identical-looking rtx's. | |
45183e03 | 1725 | Expect that X and Y has been already canonicalized. |
9ae8ffe7 JL |
1726 | |
1727 | We use the data in reg_known_value above to see if two registers with | |
1728 | different numbers are, in fact, equivalent. */ | |
1729 | ||
1730 | static int | |
ed7a4b4b | 1731 | rtx_equal_for_memref_p (const_rtx x, const_rtx y) |
9ae8ffe7 | 1732 | { |
b3694847 SS |
1733 | int i; |
1734 | int j; | |
1735 | enum rtx_code code; | |
1736 | const char *fmt; | |
9ae8ffe7 JL |
1737 | |
1738 | if (x == 0 && y == 0) | |
1739 | return 1; | |
1740 | if (x == 0 || y == 0) | |
1741 | return 0; | |
d4b60170 | 1742 | |
9ae8ffe7 JL |
1743 | if (x == y) |
1744 | return 1; | |
1745 | ||
1746 | code = GET_CODE (x); | |
1747 | /* Rtx's of different codes cannot be equal. */ | |
1748 | if (code != GET_CODE (y)) | |
1749 | return 0; | |
1750 | ||
1751 | /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. | |
1752 | (REG:SI x) and (REG:HI x) are NOT equivalent. */ | |
1753 | ||
1754 | if (GET_MODE (x) != GET_MODE (y)) | |
1755 | return 0; | |
1756 | ||
db048faf MM |
1757 | /* Some RTL can be compared without a recursive examination. */ |
1758 | switch (code) | |
1759 | { | |
1760 | case REG: | |
1761 | return REGNO (x) == REGNO (y); | |
1762 | ||
1763 | case LABEL_REF: | |
04a121a7 | 1764 | return label_ref_label (x) == label_ref_label (y); |
ca7fd9cd | 1765 | |
db048faf | 1766 | case SYMBOL_REF: |
73e48cb3 | 1767 | return compare_base_symbol_refs (x, y) == 1; |
db048faf | 1768 | |
af6236c1 AO |
1769 | case ENTRY_VALUE: |
1770 | /* This is magic, don't go through canonicalization et al. */ | |
1771 | return rtx_equal_p (ENTRY_VALUE_EXP (x), ENTRY_VALUE_EXP (y)); | |
1772 | ||
40e02b4a | 1773 | case VALUE: |
d8116890 | 1774 | CASE_CONST_UNIQUE: |
807e902e | 1775 | /* Pointer equality guarantees equality for these nodes. */ |
db048faf MM |
1776 | return 0; |
1777 | ||
db048faf MM |
1778 | default: |
1779 | break; | |
1780 | } | |
9ae8ffe7 | 1781 | |
45183e03 JH |
1782 | /* canon_rtx knows how to handle plus. No need to canonicalize. */ |
1783 | if (code == PLUS) | |
9ae8ffe7 JL |
1784 | return ((rtx_equal_for_memref_p (XEXP (x, 0), XEXP (y, 0)) |
1785 | && rtx_equal_for_memref_p (XEXP (x, 1), XEXP (y, 1))) | |
1786 | || (rtx_equal_for_memref_p (XEXP (x, 0), XEXP (y, 1)) | |
1787 | && rtx_equal_for_memref_p (XEXP (x, 1), XEXP (y, 0)))); | |
45183e03 JH |
1788 | /* For commutative operations, the RTX match if the operand match in any |
1789 | order. Also handle the simple binary and unary cases without a loop. */ | |
ec8e098d | 1790 | if (COMMUTATIVE_P (x)) |
45183e03 JH |
1791 | { |
1792 | rtx xop0 = canon_rtx (XEXP (x, 0)); | |
1793 | rtx yop0 = canon_rtx (XEXP (y, 0)); | |
1794 | rtx yop1 = canon_rtx (XEXP (y, 1)); | |
1795 | ||
1796 | return ((rtx_equal_for_memref_p (xop0, yop0) | |
1797 | && rtx_equal_for_memref_p (canon_rtx (XEXP (x, 1)), yop1)) | |
1798 | || (rtx_equal_for_memref_p (xop0, yop1) | |
1799 | && rtx_equal_for_memref_p (canon_rtx (XEXP (x, 1)), yop0))); | |
1800 | } | |
ec8e098d | 1801 | else if (NON_COMMUTATIVE_P (x)) |
45183e03 JH |
1802 | { |
1803 | return (rtx_equal_for_memref_p (canon_rtx (XEXP (x, 0)), | |
4682ae04 | 1804 | canon_rtx (XEXP (y, 0))) |
45183e03 JH |
1805 | && rtx_equal_for_memref_p (canon_rtx (XEXP (x, 1)), |
1806 | canon_rtx (XEXP (y, 1)))); | |
1807 | } | |
ec8e098d | 1808 | else if (UNARY_P (x)) |
45183e03 | 1809 | return rtx_equal_for_memref_p (canon_rtx (XEXP (x, 0)), |
4682ae04 | 1810 | canon_rtx (XEXP (y, 0))); |
9ae8ffe7 JL |
1811 | |
1812 | /* Compare the elements. If any pair of corresponding elements | |
de12be17 JC |
1813 | fail to match, return 0 for the whole things. |
1814 | ||
1815 | Limit cases to types which actually appear in addresses. */ | |
9ae8ffe7 JL |
1816 | |
1817 | fmt = GET_RTX_FORMAT (code); | |
1818 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
1819 | { | |
1820 | switch (fmt[i]) | |
1821 | { | |
9ae8ffe7 JL |
1822 | case 'i': |
1823 | if (XINT (x, i) != XINT (y, i)) | |
1824 | return 0; | |
1825 | break; | |
1826 | ||
9ae8ffe7 JL |
1827 | case 'E': |
1828 | /* Two vectors must have the same length. */ | |
1829 | if (XVECLEN (x, i) != XVECLEN (y, i)) | |
1830 | return 0; | |
1831 | ||
1832 | /* And the corresponding elements must match. */ | |
1833 | for (j = 0; j < XVECLEN (x, i); j++) | |
45183e03 JH |
1834 | if (rtx_equal_for_memref_p (canon_rtx (XVECEXP (x, i, j)), |
1835 | canon_rtx (XVECEXP (y, i, j))) == 0) | |
9ae8ffe7 JL |
1836 | return 0; |
1837 | break; | |
1838 | ||
1839 | case 'e': | |
45183e03 JH |
1840 | if (rtx_equal_for_memref_p (canon_rtx (XEXP (x, i)), |
1841 | canon_rtx (XEXP (y, i))) == 0) | |
9ae8ffe7 JL |
1842 | return 0; |
1843 | break; | |
1844 | ||
3237ac18 AH |
1845 | /* This can happen for asm operands. */ |
1846 | case 's': | |
1847 | if (strcmp (XSTR (x, i), XSTR (y, i))) | |
1848 | return 0; | |
1849 | break; | |
1850 | ||
aee21ba9 JL |
1851 | /* This can happen for an asm which clobbers memory. */ |
1852 | case '0': | |
1853 | break; | |
1854 | ||
9ae8ffe7 JL |
1855 | /* It is believed that rtx's at this level will never |
1856 | contain anything but integers and other rtx's, | |
1857 | except for within LABEL_REFs and SYMBOL_REFs. */ | |
1858 | default: | |
298e6adc | 1859 | gcc_unreachable (); |
9ae8ffe7 JL |
1860 | } |
1861 | } | |
1862 | return 1; | |
1863 | } | |
1864 | ||
9e412ca3 | 1865 | static rtx |
4682ae04 | 1866 | find_base_term (rtx x) |
9ae8ffe7 | 1867 | { |
eab5c70a | 1868 | cselib_val *val; |
6f2ffb4b AO |
1869 | struct elt_loc_list *l, *f; |
1870 | rtx ret; | |
eab5c70a | 1871 | |
b949ea8b JW |
1872 | #if defined (FIND_BASE_TERM) |
1873 | /* Try machine-dependent ways to find the base term. */ | |
1874 | x = FIND_BASE_TERM (x); | |
1875 | #endif | |
1876 | ||
9ae8ffe7 JL |
1877 | switch (GET_CODE (x)) |
1878 | { | |
1879 | case REG: | |
1880 | return REG_BASE_VALUE (x); | |
1881 | ||
d288e53d | 1882 | case TRUNCATE: |
5932a4d4 | 1883 | /* As we do not know which address space the pointer is referring to, we can |
d4ebfa65 BE |
1884 | handle this only if the target does not support different pointer or |
1885 | address modes depending on the address space. */ | |
1886 | if (!target_default_pointer_address_modes_p ()) | |
1887 | return 0; | |
d288e53d | 1888 | if (GET_MODE_SIZE (GET_MODE (x)) < GET_MODE_SIZE (Pmode)) |
ca7fd9cd | 1889 | return 0; |
d288e53d | 1890 | /* Fall through. */ |
9ae8ffe7 | 1891 | case HIGH: |
6d849a2a JL |
1892 | case PRE_INC: |
1893 | case PRE_DEC: | |
1894 | case POST_INC: | |
1895 | case POST_DEC: | |
d288e53d DE |
1896 | case PRE_MODIFY: |
1897 | case POST_MODIFY: | |
6d849a2a JL |
1898 | return find_base_term (XEXP (x, 0)); |
1899 | ||
1abade85 RK |
1900 | case ZERO_EXTEND: |
1901 | case SIGN_EXTEND: /* Used for Alpha/NT pointers */ | |
5932a4d4 | 1902 | /* As we do not know which address space the pointer is referring to, we can |
d4ebfa65 BE |
1903 | handle this only if the target does not support different pointer or |
1904 | address modes depending on the address space. */ | |
1905 | if (!target_default_pointer_address_modes_p ()) | |
1906 | return 0; | |
1907 | ||
1abade85 RK |
1908 | { |
1909 | rtx temp = find_base_term (XEXP (x, 0)); | |
1910 | ||
5ae6cd0d | 1911 | if (temp != 0 && CONSTANT_P (temp)) |
1abade85 | 1912 | temp = convert_memory_address (Pmode, temp); |
1abade85 RK |
1913 | |
1914 | return temp; | |
1915 | } | |
1916 | ||
eab5c70a BS |
1917 | case VALUE: |
1918 | val = CSELIB_VAL_PTR (x); | |
6f2ffb4b AO |
1919 | ret = NULL_RTX; |
1920 | ||
40e02b4a | 1921 | if (!val) |
6f2ffb4b AO |
1922 | return ret; |
1923 | ||
0fe03ac3 JJ |
1924 | if (cselib_sp_based_value_p (val)) |
1925 | return static_reg_base_value[STACK_POINTER_REGNUM]; | |
1926 | ||
6f2ffb4b AO |
1927 | f = val->locs; |
1928 | /* Temporarily reset val->locs to avoid infinite recursion. */ | |
1929 | val->locs = NULL; | |
1930 | ||
1931 | for (l = f; l; l = l->next) | |
1932 | if (GET_CODE (l->loc) == VALUE | |
1933 | && CSELIB_VAL_PTR (l->loc)->locs | |
1934 | && !CSELIB_VAL_PTR (l->loc)->locs->next | |
1935 | && CSELIB_VAL_PTR (l->loc)->locs->loc == x) | |
1936 | continue; | |
1937 | else if ((ret = find_base_term (l->loc)) != 0) | |
1938 | break; | |
1939 | ||
1940 | val->locs = f; | |
1941 | return ret; | |
eab5c70a | 1942 | |
023f059b JJ |
1943 | case LO_SUM: |
1944 | /* The standard form is (lo_sum reg sym) so look only at the | |
1945 | second operand. */ | |
1946 | return find_base_term (XEXP (x, 1)); | |
1947 | ||
9ae8ffe7 JL |
1948 | case CONST: |
1949 | x = XEXP (x, 0); | |
1950 | if (GET_CODE (x) != PLUS && GET_CODE (x) != MINUS) | |
1951 | return 0; | |
938d968e | 1952 | /* Fall through. */ |
9ae8ffe7 JL |
1953 | case PLUS: |
1954 | case MINUS: | |
1955 | { | |
3c567fae JL |
1956 | rtx tmp1 = XEXP (x, 0); |
1957 | rtx tmp2 = XEXP (x, 1); | |
1958 | ||
f5143c46 | 1959 | /* This is a little bit tricky since we have to determine which of |
3c567fae JL |
1960 | the two operands represents the real base address. Otherwise this |
1961 | routine may return the index register instead of the base register. | |
1962 | ||
1963 | That may cause us to believe no aliasing was possible, when in | |
1964 | fact aliasing is possible. | |
1965 | ||
1966 | We use a few simple tests to guess the base register. Additional | |
1967 | tests can certainly be added. For example, if one of the operands | |
1968 | is a shift or multiply, then it must be the index register and the | |
1969 | other operand is the base register. */ | |
ca7fd9cd | 1970 | |
b949ea8b JW |
1971 | if (tmp1 == pic_offset_table_rtx && CONSTANT_P (tmp2)) |
1972 | return find_base_term (tmp2); | |
1973 | ||
31b0a960 | 1974 | /* If either operand is known to be a pointer, then prefer it |
3c567fae | 1975 | to determine the base term. */ |
3502dc9c | 1976 | if (REG_P (tmp1) && REG_POINTER (tmp1)) |
31b0a960 RB |
1977 | ; |
1978 | else if (REG_P (tmp2) && REG_POINTER (tmp2)) | |
a7c75343 JJ |
1979 | std::swap (tmp1, tmp2); |
1980 | /* If second argument is constant which has base term, prefer it | |
1981 | over variable tmp1. See PR64025. */ | |
1982 | else if (CONSTANT_P (tmp2) && !CONST_INT_P (tmp2)) | |
1983 | std::swap (tmp1, tmp2); | |
3c567fae | 1984 | |
31b0a960 RB |
1985 | /* Go ahead and find the base term for both operands. If either base |
1986 | term is from a pointer or is a named object or a special address | |
3c567fae JL |
1987 | (like an argument or stack reference), then use it for the |
1988 | base term. */ | |
481be1c4 RB |
1989 | rtx base = find_base_term (tmp1); |
1990 | if (base != NULL_RTX | |
31b0a960 | 1991 | && ((REG_P (tmp1) && REG_POINTER (tmp1)) |
481be1c4 RB |
1992 | || known_base_value_p (base))) |
1993 | return base; | |
1994 | base = find_base_term (tmp2); | |
1995 | if (base != NULL_RTX | |
31b0a960 | 1996 | && ((REG_P (tmp2) && REG_POINTER (tmp2)) |
481be1c4 RB |
1997 | || known_base_value_p (base))) |
1998 | return base; | |
3c567fae JL |
1999 | |
2000 | /* We could not determine which of the two operands was the | |
2001 | base register and which was the index. So we can determine | |
2002 | nothing from the base alias check. */ | |
2003 | return 0; | |
9ae8ffe7 JL |
2004 | } |
2005 | ||
2006 | case AND: | |
481683e1 | 2007 | if (CONST_INT_P (XEXP (x, 1)) && INTVAL (XEXP (x, 1)) != 0) |
d288e53d | 2008 | return find_base_term (XEXP (x, 0)); |
9ae8ffe7 JL |
2009 | return 0; |
2010 | ||
2011 | case SYMBOL_REF: | |
2012 | case LABEL_REF: | |
2013 | return x; | |
2014 | ||
2015 | default: | |
2016 | return 0; | |
2017 | } | |
2018 | } | |
2019 | ||
9e412ca3 RS |
2020 | /* Return true if accesses to address X may alias accesses based |
2021 | on the stack pointer. */ | |
2022 | ||
2023 | bool | |
2024 | may_be_sp_based_p (rtx x) | |
2025 | { | |
2026 | rtx base = find_base_term (x); | |
2027 | return !base || base == static_reg_base_value[STACK_POINTER_REGNUM]; | |
2028 | } | |
2029 | ||
54363f8a JH |
2030 | /* BASE1 and BASE2 are decls. Return 1 if they refer to same object, 0 |
2031 | if they refer to different objects and -1 if we can not decide. */ | |
2032 | ||
2033 | int | |
2034 | compare_base_decls (tree base1, tree base2) | |
2035 | { | |
2036 | int ret; | |
2037 | gcc_checking_assert (DECL_P (base1) && DECL_P (base2)); | |
2038 | if (base1 == base2) | |
2039 | return 1; | |
2040 | ||
54363f8a JH |
2041 | /* Declarations of non-automatic variables may have aliases. All other |
2042 | decls are unique. */ | |
7ec4f343 NS |
2043 | if (!decl_in_symtab_p (base1) |
2044 | || !decl_in_symtab_p (base2)) | |
54363f8a | 2045 | return 0; |
7ec4f343 | 2046 | |
929710d9 NS |
2047 | /* Don't cause symbols to be inserted by the act of checking. */ |
2048 | symtab_node *node1 = symtab_node::get (base1); | |
2049 | if (!node1) | |
2050 | return 0; | |
2051 | symtab_node *node2 = symtab_node::get (base2); | |
2052 | if (!node2) | |
2053 | return 0; | |
2054 | ||
2055 | ret = node1->equal_address_to (node2, true); | |
54363f8a JH |
2056 | return ret; |
2057 | } | |
2058 | ||
73e48cb3 JH |
2059 | /* Same as compare_base_decls but for SYMBOL_REF. */ |
2060 | ||
2061 | static int | |
2062 | compare_base_symbol_refs (const_rtx x_base, const_rtx y_base) | |
2063 | { | |
2064 | tree x_decl = SYMBOL_REF_DECL (x_base); | |
2065 | tree y_decl = SYMBOL_REF_DECL (y_base); | |
2066 | bool binds_def = true; | |
2067 | ||
2068 | if (XSTR (x_base, 0) == XSTR (y_base, 0)) | |
2069 | return 1; | |
2070 | if (x_decl && y_decl) | |
2071 | return compare_base_decls (x_decl, y_decl); | |
2072 | if (x_decl || y_decl) | |
2073 | { | |
2074 | if (!x_decl) | |
2075 | { | |
2076 | std::swap (x_decl, y_decl); | |
2077 | std::swap (x_base, y_base); | |
2078 | } | |
2079 | /* We handle specially only section anchors and assume that other | |
2080 | labels may overlap with user variables in an arbitrary way. */ | |
2081 | if (!SYMBOL_REF_HAS_BLOCK_INFO_P (y_base)) | |
2082 | return -1; | |
2083 | /* Anchors contains static VAR_DECLs and CONST_DECLs. We are safe | |
2084 | to ignore CONST_DECLs because they are readonly. */ | |
8813a647 | 2085 | if (!VAR_P (x_decl) |
73e48cb3 JH |
2086 | || (!TREE_STATIC (x_decl) && !TREE_PUBLIC (x_decl))) |
2087 | return 0; | |
2088 | ||
2089 | symtab_node *x_node = symtab_node::get_create (x_decl) | |
2090 | ->ultimate_alias_target (); | |
2091 | /* External variable can not be in section anchor. */ | |
2092 | if (!x_node->definition) | |
2093 | return 0; | |
2094 | x_base = XEXP (DECL_RTL (x_node->decl), 0); | |
2095 | /* If not in anchor, we can disambiguate. */ | |
2096 | if (!SYMBOL_REF_HAS_BLOCK_INFO_P (x_base)) | |
2097 | return 0; | |
2098 | ||
2099 | /* We have an alias of anchored variable. If it can be interposed; | |
2100 | we must assume it may or may not alias its anchor. */ | |
2101 | binds_def = decl_binds_to_current_def_p (x_decl); | |
2102 | } | |
2103 | /* If we have variable in section anchor, we can compare by offset. */ | |
2104 | if (SYMBOL_REF_HAS_BLOCK_INFO_P (x_base) | |
2105 | && SYMBOL_REF_HAS_BLOCK_INFO_P (y_base)) | |
2106 | { | |
2107 | if (SYMBOL_REF_BLOCK (x_base) != SYMBOL_REF_BLOCK (y_base)) | |
2108 | return 0; | |
2109 | if (SYMBOL_REF_BLOCK_OFFSET (x_base) == SYMBOL_REF_BLOCK_OFFSET (y_base)) | |
2110 | return binds_def ? 1 : -1; | |
2111 | if (SYMBOL_REF_ANCHOR_P (x_base) != SYMBOL_REF_ANCHOR_P (y_base)) | |
2112 | return -1; | |
2113 | return 0; | |
2114 | } | |
2115 | /* In general we assume that memory locations pointed to by different labels | |
2116 | may overlap in undefined ways. */ | |
2117 | return -1; | |
2118 | } | |
2119 | ||
9ae8ffe7 JL |
2120 | /* Return 0 if the addresses X and Y are known to point to different |
2121 | objects, 1 if they might be pointers to the same object. */ | |
2122 | ||
2123 | static int | |
31b0a960 | 2124 | base_alias_check (rtx x, rtx x_base, rtx y, rtx y_base, |
ef4bddc2 | 2125 | machine_mode x_mode, machine_mode y_mode) |
9ae8ffe7 | 2126 | { |
1c72c7f6 JC |
2127 | /* If the address itself has no known base see if a known equivalent |
2128 | value has one. If either address still has no known base, nothing | |
2129 | is known about aliasing. */ | |
2130 | if (x_base == 0) | |
2131 | { | |
2132 | rtx x_c; | |
d4b60170 | 2133 | |
1c72c7f6 JC |
2134 | if (! flag_expensive_optimizations || (x_c = canon_rtx (x)) == x) |
2135 | return 1; | |
d4b60170 | 2136 | |
1c72c7f6 JC |
2137 | x_base = find_base_term (x_c); |
2138 | if (x_base == 0) | |
2139 | return 1; | |
2140 | } | |
9ae8ffe7 | 2141 | |
1c72c7f6 JC |
2142 | if (y_base == 0) |
2143 | { | |
2144 | rtx y_c; | |
2145 | if (! flag_expensive_optimizations || (y_c = canon_rtx (y)) == y) | |
2146 | return 1; | |
d4b60170 | 2147 | |
1c72c7f6 JC |
2148 | y_base = find_base_term (y_c); |
2149 | if (y_base == 0) | |
2150 | return 1; | |
2151 | } | |
2152 | ||
2153 | /* If the base addresses are equal nothing is known about aliasing. */ | |
2154 | if (rtx_equal_p (x_base, y_base)) | |
9ae8ffe7 JL |
2155 | return 1; |
2156 | ||
435da628 UB |
2157 | /* The base addresses are different expressions. If they are not accessed |
2158 | via AND, there is no conflict. We can bring knowledge of object | |
2159 | alignment into play here. For example, on alpha, "char a, b;" can | |
2160 | alias one another, though "char a; long b;" cannot. AND addesses may | |
2161 | implicitly alias surrounding objects; i.e. unaligned access in DImode | |
2162 | via AND address can alias all surrounding object types except those | |
2163 | with aligment 8 or higher. */ | |
2164 | if (GET_CODE (x) == AND && GET_CODE (y) == AND) | |
2165 | return 1; | |
2166 | if (GET_CODE (x) == AND | |
481683e1 | 2167 | && (!CONST_INT_P (XEXP (x, 1)) |
435da628 UB |
2168 | || (int) GET_MODE_UNIT_SIZE (y_mode) < -INTVAL (XEXP (x, 1)))) |
2169 | return 1; | |
2170 | if (GET_CODE (y) == AND | |
481683e1 | 2171 | && (!CONST_INT_P (XEXP (y, 1)) |
435da628 UB |
2172 | || (int) GET_MODE_UNIT_SIZE (x_mode) < -INTVAL (XEXP (y, 1)))) |
2173 | return 1; | |
2174 | ||
73e48cb3 | 2175 | /* Differing symbols not accessed via AND never alias. */ |
3a28db46 | 2176 | if (GET_CODE (x_base) == SYMBOL_REF && GET_CODE (y_base) == SYMBOL_REF) |
73e48cb3 | 2177 | return compare_base_symbol_refs (x_base, y_base) != 0; |
3a28db46 | 2178 | |
9ae8ffe7 | 2179 | if (GET_CODE (x_base) != ADDRESS && GET_CODE (y_base) != ADDRESS) |
435da628 | 2180 | return 0; |
9ae8ffe7 | 2181 | |
9fc37b2b | 2182 | if (unique_base_value_p (x_base) || unique_base_value_p (y_base)) |
9ae8ffe7 JL |
2183 | return 0; |
2184 | ||
0d3c82d6 | 2185 | return 1; |
9ae8ffe7 JL |
2186 | } |
2187 | ||
a5628378 | 2188 | /* Return TRUE if EXPR refers to a VALUE whose uid is greater than |
c779924e | 2189 | (or equal to) that of V. */ |
a5628378 AO |
2190 | |
2191 | static bool | |
403837b4 | 2192 | refs_newer_value_p (const_rtx expr, rtx v) |
a5628378 AO |
2193 | { |
2194 | int minuid = CSELIB_VAL_PTR (v)->uid; | |
403837b4 RS |
2195 | subrtx_iterator::array_type array; |
2196 | FOR_EACH_SUBRTX (iter, array, expr, NONCONST) | |
c779924e | 2197 | if (GET_CODE (*iter) == VALUE && CSELIB_VAL_PTR (*iter)->uid >= minuid) |
403837b4 RS |
2198 | return true; |
2199 | return false; | |
a5628378 AO |
2200 | } |
2201 | ||
eab5c70a | 2202 | /* Convert the address X into something we can use. This is done by returning |
569efc34 JJ |
2203 | it unchanged unless it is a VALUE or VALUE +/- constant; for VALUE |
2204 | we call cselib to get a more useful rtx. */ | |
3bdf5ad1 | 2205 | |
a13d4ebf | 2206 | rtx |
4682ae04 | 2207 | get_addr (rtx x) |
eab5c70a BS |
2208 | { |
2209 | cselib_val *v; | |
2210 | struct elt_loc_list *l; | |
2211 | ||
2212 | if (GET_CODE (x) != VALUE) | |
569efc34 JJ |
2213 | { |
2214 | if ((GET_CODE (x) == PLUS || GET_CODE (x) == MINUS) | |
2215 | && GET_CODE (XEXP (x, 0)) == VALUE | |
2216 | && CONST_SCALAR_INT_P (XEXP (x, 1))) | |
2217 | { | |
2218 | rtx op0 = get_addr (XEXP (x, 0)); | |
2219 | if (op0 != XEXP (x, 0)) | |
2220 | { | |
2221 | if (GET_CODE (x) == PLUS | |
2222 | && GET_CODE (XEXP (x, 1)) == CONST_INT) | |
2223 | return plus_constant (GET_MODE (x), op0, INTVAL (XEXP (x, 1))); | |
2224 | return simplify_gen_binary (GET_CODE (x), GET_MODE (x), | |
2225 | op0, XEXP (x, 1)); | |
2226 | } | |
2227 | } | |
2228 | return x; | |
2229 | } | |
eab5c70a | 2230 | v = CSELIB_VAL_PTR (x); |
40e02b4a JH |
2231 | if (v) |
2232 | { | |
0f68ba3e AO |
2233 | bool have_equivs = cselib_have_permanent_equivalences (); |
2234 | if (have_equivs) | |
2235 | v = canonical_cselib_val (v); | |
40e02b4a JH |
2236 | for (l = v->locs; l; l = l->next) |
2237 | if (CONSTANT_P (l->loc)) | |
2238 | return l->loc; | |
2239 | for (l = v->locs; l; l = l->next) | |
0f68ba3e AO |
2240 | if (!REG_P (l->loc) && !MEM_P (l->loc) |
2241 | /* Avoid infinite recursion when potentially dealing with | |
2242 | var-tracking artificial equivalences, by skipping the | |
2243 | equivalences themselves, and not choosing expressions | |
2244 | that refer to newer VALUEs. */ | |
2245 | && (!have_equivs | |
2246 | || (GET_CODE (l->loc) != VALUE | |
2247 | && !refs_newer_value_p (l->loc, x)))) | |
a5628378 | 2248 | return l->loc; |
0f68ba3e AO |
2249 | if (have_equivs) |
2250 | { | |
2251 | for (l = v->locs; l; l = l->next) | |
2252 | if (REG_P (l->loc) | |
2253 | || (GET_CODE (l->loc) != VALUE | |
2254 | && !refs_newer_value_p (l->loc, x))) | |
2255 | return l->loc; | |
2256 | /* Return the canonical value. */ | |
2257 | return v->val_rtx; | |
2258 | } | |
2259 | if (v->locs) | |
2260 | return v->locs->loc; | |
40e02b4a | 2261 | } |
eab5c70a BS |
2262 | return x; |
2263 | } | |
2264 | ||
39cec1ac MH |
2265 | /* Return the address of the (N_REFS + 1)th memory reference to ADDR |
2266 | where SIZE is the size in bytes of the memory reference. If ADDR | |
2267 | is not modified by the memory reference then ADDR is returned. */ | |
2268 | ||
04e2b4d3 | 2269 | static rtx |
4682ae04 | 2270 | addr_side_effect_eval (rtx addr, int size, int n_refs) |
39cec1ac MH |
2271 | { |
2272 | int offset = 0; | |
ca7fd9cd | 2273 | |
39cec1ac MH |
2274 | switch (GET_CODE (addr)) |
2275 | { | |
2276 | case PRE_INC: | |
2277 | offset = (n_refs + 1) * size; | |
2278 | break; | |
2279 | case PRE_DEC: | |
2280 | offset = -(n_refs + 1) * size; | |
2281 | break; | |
2282 | case POST_INC: | |
2283 | offset = n_refs * size; | |
2284 | break; | |
2285 | case POST_DEC: | |
2286 | offset = -n_refs * size; | |
2287 | break; | |
2288 | ||
2289 | default: | |
2290 | return addr; | |
2291 | } | |
ca7fd9cd | 2292 | |
39cec1ac | 2293 | if (offset) |
45183e03 | 2294 | addr = gen_rtx_PLUS (GET_MODE (addr), XEXP (addr, 0), |
4789c0ce | 2295 | gen_int_mode (offset, GET_MODE (addr))); |
39cec1ac MH |
2296 | else |
2297 | addr = XEXP (addr, 0); | |
45183e03 | 2298 | addr = canon_rtx (addr); |
39cec1ac MH |
2299 | |
2300 | return addr; | |
2301 | } | |
2302 | ||
3aa03517 AO |
2303 | /* Return TRUE if an object X sized at XSIZE bytes and another object |
2304 | Y sized at YSIZE bytes, starting C bytes after X, may overlap. If | |
2305 | any of the sizes is zero, assume an overlap, otherwise use the | |
2306 | absolute value of the sizes as the actual sizes. */ | |
2307 | ||
2308 | static inline bool | |
2309 | offset_overlap_p (HOST_WIDE_INT c, int xsize, int ysize) | |
2310 | { | |
2311 | return (xsize == 0 || ysize == 0 | |
2312 | || (c >= 0 | |
2313 | ? (abs (xsize) > c) | |
2314 | : (abs (ysize) > -c))); | |
2315 | } | |
2316 | ||
f47e08d9 RG |
2317 | /* Return one if X and Y (memory addresses) reference the |
2318 | same location in memory or if the references overlap. | |
2319 | Return zero if they do not overlap, else return | |
2320 | minus one in which case they still might reference the same location. | |
2321 | ||
2322 | C is an offset accumulator. When | |
9ae8ffe7 JL |
2323 | C is nonzero, we are testing aliases between X and Y + C. |
2324 | XSIZE is the size in bytes of the X reference, | |
2325 | similarly YSIZE is the size in bytes for Y. | |
45183e03 | 2326 | Expect that canon_rtx has been already called for X and Y. |
9ae8ffe7 JL |
2327 | |
2328 | If XSIZE or YSIZE is zero, we do not know the amount of memory being | |
2329 | referenced (the reference was BLKmode), so make the most pessimistic | |
2330 | assumptions. | |
2331 | ||
c02f035f RH |
2332 | If XSIZE or YSIZE is negative, we may access memory outside the object |
2333 | being referenced as a side effect. This can happen when using AND to | |
2334 | align memory references, as is done on the Alpha. | |
2335 | ||
9ae8ffe7 | 2336 | Nice to notice that varying addresses cannot conflict with fp if no |
f47e08d9 RG |
2337 | local variables had their addresses taken, but that's too hard now. |
2338 | ||
2339 | ??? Contrary to the tree alias oracle this does not return | |
2340 | one for X + non-constant and Y + non-constant when X and Y are equal. | |
2341 | If that is fixed the TBAA hack for union type-punning can be removed. */ | |
9ae8ffe7 | 2342 | |
9ae8ffe7 | 2343 | static int |
4682ae04 | 2344 | memrefs_conflict_p (int xsize, rtx x, int ysize, rtx y, HOST_WIDE_INT c) |
9ae8ffe7 | 2345 | { |
eab5c70a | 2346 | if (GET_CODE (x) == VALUE) |
5312b066 JJ |
2347 | { |
2348 | if (REG_P (y)) | |
2349 | { | |
24f8d71e JJ |
2350 | struct elt_loc_list *l = NULL; |
2351 | if (CSELIB_VAL_PTR (x)) | |
a5628378 AO |
2352 | for (l = canonical_cselib_val (CSELIB_VAL_PTR (x))->locs; |
2353 | l; l = l->next) | |
24f8d71e JJ |
2354 | if (REG_P (l->loc) && rtx_equal_for_memref_p (l->loc, y)) |
2355 | break; | |
5312b066 JJ |
2356 | if (l) |
2357 | x = y; | |
2358 | else | |
2359 | x = get_addr (x); | |
2360 | } | |
2361 | /* Don't call get_addr if y is the same VALUE. */ | |
2362 | else if (x != y) | |
2363 | x = get_addr (x); | |
2364 | } | |
eab5c70a | 2365 | if (GET_CODE (y) == VALUE) |
5312b066 JJ |
2366 | { |
2367 | if (REG_P (x)) | |
2368 | { | |
24f8d71e JJ |
2369 | struct elt_loc_list *l = NULL; |
2370 | if (CSELIB_VAL_PTR (y)) | |
a5628378 AO |
2371 | for (l = canonical_cselib_val (CSELIB_VAL_PTR (y))->locs; |
2372 | l; l = l->next) | |
24f8d71e JJ |
2373 | if (REG_P (l->loc) && rtx_equal_for_memref_p (l->loc, x)) |
2374 | break; | |
5312b066 JJ |
2375 | if (l) |
2376 | y = x; | |
2377 | else | |
2378 | y = get_addr (y); | |
2379 | } | |
2380 | /* Don't call get_addr if x is the same VALUE. */ | |
2381 | else if (y != x) | |
2382 | y = get_addr (y); | |
2383 | } | |
9ae8ffe7 JL |
2384 | if (GET_CODE (x) == HIGH) |
2385 | x = XEXP (x, 0); | |
2386 | else if (GET_CODE (x) == LO_SUM) | |
2387 | x = XEXP (x, 1); | |
2388 | else | |
3aa03517 | 2389 | x = addr_side_effect_eval (x, abs (xsize), 0); |
9ae8ffe7 JL |
2390 | if (GET_CODE (y) == HIGH) |
2391 | y = XEXP (y, 0); | |
2392 | else if (GET_CODE (y) == LO_SUM) | |
2393 | y = XEXP (y, 1); | |
2394 | else | |
3aa03517 | 2395 | y = addr_side_effect_eval (y, abs (ysize), 0); |
9ae8ffe7 | 2396 | |
54363f8a JH |
2397 | if (GET_CODE (x) == SYMBOL_REF && GET_CODE (y) == SYMBOL_REF) |
2398 | { | |
73e48cb3 | 2399 | int cmp = compare_base_symbol_refs (x,y); |
54363f8a JH |
2400 | |
2401 | /* If both decls are the same, decide by offsets. */ | |
2402 | if (cmp == 1) | |
2403 | return offset_overlap_p (c, xsize, ysize); | |
3a28db46 UB |
2404 | /* Assume a potential overlap for symbolic addresses that went |
2405 | through alignment adjustments (i.e., that have negative | |
2406 | sizes), because we can't know how far they are from each | |
2407 | other. */ | |
2408 | if (xsize < 0 || ysize < 0) | |
2409 | return -1; | |
54363f8a JH |
2410 | /* If decls are different or we know by offsets that there is no overlap, |
2411 | we win. */ | |
2412 | if (!cmp || !offset_overlap_p (c, xsize, ysize)) | |
2413 | return 0; | |
2414 | /* Decls may or may not be different and offsets overlap....*/ | |
2415 | return -1; | |
2416 | } | |
2417 | else if (rtx_equal_for_memref_p (x, y)) | |
9ae8ffe7 | 2418 | { |
3aa03517 | 2419 | return offset_overlap_p (c, xsize, ysize); |
9ae8ffe7 JL |
2420 | } |
2421 | ||
6e73e666 JC |
2422 | /* This code used to check for conflicts involving stack references and |
2423 | globals but the base address alias code now handles these cases. */ | |
9ae8ffe7 JL |
2424 | |
2425 | if (GET_CODE (x) == PLUS) | |
2426 | { | |
2427 | /* The fact that X is canonicalized means that this | |
2428 | PLUS rtx is canonicalized. */ | |
2429 | rtx x0 = XEXP (x, 0); | |
2430 | rtx x1 = XEXP (x, 1); | |
2431 | ||
2d88904a AO |
2432 | /* However, VALUEs might end up in different positions even in |
2433 | canonical PLUSes. Comparing their addresses is enough. */ | |
2434 | if (x0 == y) | |
2435 | return memrefs_conflict_p (xsize, x1, ysize, const0_rtx, c); | |
2436 | else if (x1 == y) | |
2437 | return memrefs_conflict_p (xsize, x0, ysize, const0_rtx, c); | |
2438 | ||
9ae8ffe7 JL |
2439 | if (GET_CODE (y) == PLUS) |
2440 | { | |
2441 | /* The fact that Y is canonicalized means that this | |
2442 | PLUS rtx is canonicalized. */ | |
2443 | rtx y0 = XEXP (y, 0); | |
2444 | rtx y1 = XEXP (y, 1); | |
2445 | ||
2d88904a AO |
2446 | if (x0 == y1) |
2447 | return memrefs_conflict_p (xsize, x1, ysize, y0, c); | |
2448 | if (x1 == y0) | |
2449 | return memrefs_conflict_p (xsize, x0, ysize, y1, c); | |
2450 | ||
9ae8ffe7 JL |
2451 | if (rtx_equal_for_memref_p (x1, y1)) |
2452 | return memrefs_conflict_p (xsize, x0, ysize, y0, c); | |
2453 | if (rtx_equal_for_memref_p (x0, y0)) | |
2454 | return memrefs_conflict_p (xsize, x1, ysize, y1, c); | |
481683e1 | 2455 | if (CONST_INT_P (x1)) |
63be02db | 2456 | { |
481683e1 | 2457 | if (CONST_INT_P (y1)) |
63be02db JM |
2458 | return memrefs_conflict_p (xsize, x0, ysize, y0, |
2459 | c - INTVAL (x1) + INTVAL (y1)); | |
2460 | else | |
2461 | return memrefs_conflict_p (xsize, x0, ysize, y, | |
2462 | c - INTVAL (x1)); | |
2463 | } | |
481683e1 | 2464 | else if (CONST_INT_P (y1)) |
9ae8ffe7 JL |
2465 | return memrefs_conflict_p (xsize, x, ysize, y0, c + INTVAL (y1)); |
2466 | ||
f47e08d9 | 2467 | return -1; |
9ae8ffe7 | 2468 | } |
481683e1 | 2469 | else if (CONST_INT_P (x1)) |
9ae8ffe7 JL |
2470 | return memrefs_conflict_p (xsize, x0, ysize, y, c - INTVAL (x1)); |
2471 | } | |
2472 | else if (GET_CODE (y) == PLUS) | |
2473 | { | |
2474 | /* The fact that Y is canonicalized means that this | |
2475 | PLUS rtx is canonicalized. */ | |
2476 | rtx y0 = XEXP (y, 0); | |
2477 | rtx y1 = XEXP (y, 1); | |
2478 | ||
2d88904a AO |
2479 | if (x == y0) |
2480 | return memrefs_conflict_p (xsize, const0_rtx, ysize, y1, c); | |
2481 | if (x == y1) | |
2482 | return memrefs_conflict_p (xsize, const0_rtx, ysize, y0, c); | |
2483 | ||
481683e1 | 2484 | if (CONST_INT_P (y1)) |
9ae8ffe7 JL |
2485 | return memrefs_conflict_p (xsize, x, ysize, y0, c + INTVAL (y1)); |
2486 | else | |
f47e08d9 | 2487 | return -1; |
9ae8ffe7 JL |
2488 | } |
2489 | ||
2490 | if (GET_CODE (x) == GET_CODE (y)) | |
2491 | switch (GET_CODE (x)) | |
2492 | { | |
2493 | case MULT: | |
2494 | { | |
2495 | /* Handle cases where we expect the second operands to be the | |
2496 | same, and check only whether the first operand would conflict | |
2497 | or not. */ | |
2498 | rtx x0, y0; | |
2499 | rtx x1 = canon_rtx (XEXP (x, 1)); | |
2500 | rtx y1 = canon_rtx (XEXP (y, 1)); | |
2501 | if (! rtx_equal_for_memref_p (x1, y1)) | |
f47e08d9 | 2502 | return -1; |
9ae8ffe7 JL |
2503 | x0 = canon_rtx (XEXP (x, 0)); |
2504 | y0 = canon_rtx (XEXP (y, 0)); | |
2505 | if (rtx_equal_for_memref_p (x0, y0)) | |
3aa03517 | 2506 | return offset_overlap_p (c, xsize, ysize); |
9ae8ffe7 JL |
2507 | |
2508 | /* Can't properly adjust our sizes. */ | |
481683e1 | 2509 | if (!CONST_INT_P (x1)) |
f47e08d9 | 2510 | return -1; |
9ae8ffe7 JL |
2511 | xsize /= INTVAL (x1); |
2512 | ysize /= INTVAL (x1); | |
2513 | c /= INTVAL (x1); | |
2514 | return memrefs_conflict_p (xsize, x0, ysize, y0, c); | |
2515 | } | |
1d300e19 KG |
2516 | |
2517 | default: | |
2518 | break; | |
9ae8ffe7 JL |
2519 | } |
2520 | ||
a9bf4fe2 AO |
2521 | /* Deal with alignment ANDs by adjusting offset and size so as to |
2522 | cover the maximum range, without taking any previously known | |
5147bf6a AO |
2523 | alignment into account. Make a size negative after such an |
2524 | adjustments, so that, if we end up with e.g. two SYMBOL_REFs, we | |
2525 | assume a potential overlap, because they may end up in contiguous | |
2526 | memory locations and the stricter-alignment access may span over | |
2527 | part of both. */ | |
481683e1 | 2528 | if (GET_CODE (x) == AND && CONST_INT_P (XEXP (x, 1))) |
56ee9281 | 2529 | { |
a9bf4fe2 AO |
2530 | HOST_WIDE_INT sc = INTVAL (XEXP (x, 1)); |
2531 | unsigned HOST_WIDE_INT uc = sc; | |
146ec50f | 2532 | if (sc < 0 && pow2_or_zerop (-uc)) |
a9bf4fe2 | 2533 | { |
5147bf6a AO |
2534 | if (xsize > 0) |
2535 | xsize = -xsize; | |
3aa03517 AO |
2536 | if (xsize) |
2537 | xsize += sc + 1; | |
fe8fb1c4 | 2538 | c -= sc + 1; |
a9bf4fe2 AO |
2539 | return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)), |
2540 | ysize, y, c); | |
2541 | } | |
56ee9281 | 2542 | } |
481683e1 | 2543 | if (GET_CODE (y) == AND && CONST_INT_P (XEXP (y, 1))) |
c02f035f | 2544 | { |
a9bf4fe2 AO |
2545 | HOST_WIDE_INT sc = INTVAL (XEXP (y, 1)); |
2546 | unsigned HOST_WIDE_INT uc = sc; | |
146ec50f | 2547 | if (sc < 0 && pow2_or_zerop (-uc)) |
a9bf4fe2 | 2548 | { |
5147bf6a AO |
2549 | if (ysize > 0) |
2550 | ysize = -ysize; | |
3aa03517 AO |
2551 | if (ysize) |
2552 | ysize += sc + 1; | |
fe8fb1c4 | 2553 | c += sc + 1; |
a9bf4fe2 AO |
2554 | return memrefs_conflict_p (xsize, x, |
2555 | ysize, canon_rtx (XEXP (y, 0)), c); | |
2556 | } | |
c02f035f | 2557 | } |
9ae8ffe7 JL |
2558 | |
2559 | if (CONSTANT_P (x)) | |
2560 | { | |
481683e1 | 2561 | if (CONST_INT_P (x) && CONST_INT_P (y)) |
9ae8ffe7 JL |
2562 | { |
2563 | c += (INTVAL (y) - INTVAL (x)); | |
3aa03517 | 2564 | return offset_overlap_p (c, xsize, ysize); |
9ae8ffe7 JL |
2565 | } |
2566 | ||
2567 | if (GET_CODE (x) == CONST) | |
2568 | { | |
2569 | if (GET_CODE (y) == CONST) | |
2570 | return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)), | |
2571 | ysize, canon_rtx (XEXP (y, 0)), c); | |
2572 | else | |
2573 | return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)), | |
2574 | ysize, y, c); | |
2575 | } | |
2576 | if (GET_CODE (y) == CONST) | |
2577 | return memrefs_conflict_p (xsize, x, ysize, | |
2578 | canon_rtx (XEXP (y, 0)), c); | |
2579 | ||
3aa03517 AO |
2580 | /* Assume a potential overlap for symbolic addresses that went |
2581 | through alignment adjustments (i.e., that have negative | |
2582 | sizes), because we can't know how far they are from each | |
2583 | other. */ | |
9ae8ffe7 | 2584 | if (CONSTANT_P (y)) |
3aa03517 | 2585 | return (xsize < 0 || ysize < 0 || offset_overlap_p (c, xsize, ysize)); |
9ae8ffe7 | 2586 | |
f47e08d9 | 2587 | return -1; |
9ae8ffe7 | 2588 | } |
f47e08d9 RG |
2589 | |
2590 | return -1; | |
9ae8ffe7 JL |
2591 | } |
2592 | ||
2593 | /* Functions to compute memory dependencies. | |
2594 | ||
2595 | Since we process the insns in execution order, we can build tables | |
2596 | to keep track of what registers are fixed (and not aliased), what registers | |
2597 | are varying in known ways, and what registers are varying in unknown | |
2598 | ways. | |
2599 | ||
2600 | If both memory references are volatile, then there must always be a | |
2601 | dependence between the two references, since their order can not be | |
2602 | changed. A volatile and non-volatile reference can be interchanged | |
ca7fd9cd | 2603 | though. |
9ae8ffe7 | 2604 | |
53d9622b RS |
2605 | We also must allow AND addresses, because they may generate accesses |
2606 | outside the object being referenced. This is used to generate aligned | |
2607 | addresses from unaligned addresses, for instance, the alpha | |
dc1618bc | 2608 | storeqi_unaligned pattern. */ |
9ae8ffe7 JL |
2609 | |
2610 | /* Read dependence: X is read after read in MEM takes place. There can | |
96672a3e RH |
2611 | only be a dependence here if both reads are volatile, or if either is |
2612 | an explicit barrier. */ | |
9ae8ffe7 JL |
2613 | |
2614 | int | |
4f588890 | 2615 | read_dependence (const_rtx mem, const_rtx x) |
9ae8ffe7 | 2616 | { |
96672a3e RH |
2617 | if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) |
2618 | return true; | |
2619 | if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER | |
2620 | || MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER) | |
2621 | return true; | |
2622 | return false; | |
9ae8ffe7 JL |
2623 | } |
2624 | ||
998d7deb RH |
2625 | /* Look at the bottom of the COMPONENT_REF list for a DECL, and return it. */ |
2626 | ||
2627 | static tree | |
4682ae04 | 2628 | decl_for_component_ref (tree x) |
998d7deb RH |
2629 | { |
2630 | do | |
2631 | { | |
2632 | x = TREE_OPERAND (x, 0); | |
2633 | } | |
2634 | while (x && TREE_CODE (x) == COMPONENT_REF); | |
2635 | ||
2636 | return x && DECL_P (x) ? x : NULL_TREE; | |
2637 | } | |
2638 | ||
527210c4 RS |
2639 | /* Walk up the COMPONENT_REF list in X and adjust *OFFSET to compensate |
2640 | for the offset of the field reference. *KNOWN_P says whether the | |
2641 | offset is known. */ | |
998d7deb | 2642 | |
527210c4 RS |
2643 | static void |
2644 | adjust_offset_for_component_ref (tree x, bool *known_p, | |
2645 | HOST_WIDE_INT *offset) | |
998d7deb | 2646 | { |
527210c4 RS |
2647 | if (!*known_p) |
2648 | return; | |
ca7fd9cd | 2649 | do |
998d7deb | 2650 | { |
527210c4 | 2651 | tree xoffset = component_ref_field_offset (x); |
998d7deb | 2652 | tree field = TREE_OPERAND (x, 1); |
807e902e KZ |
2653 | if (TREE_CODE (xoffset) != INTEGER_CST) |
2654 | { | |
2655 | *known_p = false; | |
2656 | return; | |
2657 | } | |
998d7deb | 2658 | |
807e902e KZ |
2659 | offset_int woffset |
2660 | = (wi::to_offset (xoffset) | |
8de73453 RS |
2661 | + (wi::to_offset (DECL_FIELD_BIT_OFFSET (field)) |
2662 | >> LOG2_BITS_PER_UNIT)); | |
807e902e | 2663 | if (!wi::fits_uhwi_p (woffset)) |
527210c4 RS |
2664 | { |
2665 | *known_p = false; | |
2666 | return; | |
2667 | } | |
807e902e | 2668 | *offset += woffset.to_uhwi (); |
998d7deb RH |
2669 | |
2670 | x = TREE_OPERAND (x, 0); | |
2671 | } | |
2672 | while (x && TREE_CODE (x) == COMPONENT_REF); | |
998d7deb RH |
2673 | } |
2674 | ||
95bd1dd7 | 2675 | /* Return nonzero if we can determine the exprs corresponding to memrefs |
c6ea834c BM |
2676 | X and Y and they do not overlap. |
2677 | If LOOP_VARIANT is set, skip offset-based disambiguation */ | |
a4311dfe | 2678 | |
2e4e39f6 | 2679 | int |
c6ea834c | 2680 | nonoverlapping_memrefs_p (const_rtx x, const_rtx y, bool loop_invariant) |
a4311dfe | 2681 | { |
998d7deb | 2682 | tree exprx = MEM_EXPR (x), expry = MEM_EXPR (y); |
a4311dfe RK |
2683 | rtx rtlx, rtly; |
2684 | rtx basex, basey; | |
527210c4 RS |
2685 | bool moffsetx_known_p, moffsety_known_p; |
2686 | HOST_WIDE_INT moffsetx = 0, moffsety = 0; | |
4e1952ab | 2687 | HOST_WIDE_INT offsetx = 0, offsety = 0, sizex, sizey; |
a4311dfe | 2688 | |
998d7deb RH |
2689 | /* Unless both have exprs, we can't tell anything. */ |
2690 | if (exprx == 0 || expry == 0) | |
2691 | return 0; | |
2b22e382 RG |
2692 | |
2693 | /* For spill-slot accesses make sure we have valid offsets. */ | |
2694 | if ((exprx == get_spill_slot_decl (false) | |
527210c4 | 2695 | && ! MEM_OFFSET_KNOWN_P (x)) |
2b22e382 | 2696 | || (expry == get_spill_slot_decl (false) |
527210c4 | 2697 | && ! MEM_OFFSET_KNOWN_P (y))) |
2b22e382 | 2698 | return 0; |
c22cacf3 | 2699 | |
998d7deb | 2700 | /* If the field reference test failed, look at the DECLs involved. */ |
527210c4 RS |
2701 | moffsetx_known_p = MEM_OFFSET_KNOWN_P (x); |
2702 | if (moffsetx_known_p) | |
2703 | moffsetx = MEM_OFFSET (x); | |
998d7deb RH |
2704 | if (TREE_CODE (exprx) == COMPONENT_REF) |
2705 | { | |
2e0c984c RG |
2706 | tree t = decl_for_component_ref (exprx); |
2707 | if (! t) | |
2708 | return 0; | |
527210c4 | 2709 | adjust_offset_for_component_ref (exprx, &moffsetx_known_p, &moffsetx); |
2e0c984c | 2710 | exprx = t; |
998d7deb | 2711 | } |
c67a1cf6 | 2712 | |
527210c4 RS |
2713 | moffsety_known_p = MEM_OFFSET_KNOWN_P (y); |
2714 | if (moffsety_known_p) | |
2715 | moffsety = MEM_OFFSET (y); | |
998d7deb RH |
2716 | if (TREE_CODE (expry) == COMPONENT_REF) |
2717 | { | |
2e0c984c RG |
2718 | tree t = decl_for_component_ref (expry); |
2719 | if (! t) | |
2720 | return 0; | |
527210c4 | 2721 | adjust_offset_for_component_ref (expry, &moffsety_known_p, &moffsety); |
2e0c984c | 2722 | expry = t; |
998d7deb RH |
2723 | } |
2724 | ||
2725 | if (! DECL_P (exprx) || ! DECL_P (expry)) | |
a4311dfe RK |
2726 | return 0; |
2727 | ||
1f9ceff1 AO |
2728 | /* If we refer to different gimple registers, or one gimple register |
2729 | and one non-gimple-register, we know they can't overlap. First, | |
2730 | gimple registers don't have their addresses taken. Now, there | |
2731 | could be more than one stack slot for (different versions of) the | |
2732 | same gimple register, but we can presumably tell they don't | |
2733 | overlap based on offsets from stack base addresses elsewhere. | |
2734 | It's important that we don't proceed to DECL_RTL, because gimple | |
2735 | registers may not pass DECL_RTL_SET_P, and make_decl_rtl won't be | |
2736 | able to do anything about them since no SSA information will have | |
2737 | remained to guide it. */ | |
2738 | if (is_gimple_reg (exprx) || is_gimple_reg (expry)) | |
2d88904a AO |
2739 | return exprx != expry |
2740 | || (moffsetx_known_p && moffsety_known_p | |
2741 | && MEM_SIZE_KNOWN_P (x) && MEM_SIZE_KNOWN_P (y) | |
2742 | && !offset_overlap_p (moffsety - moffsetx, | |
2743 | MEM_SIZE (x), MEM_SIZE (y))); | |
1f9ceff1 | 2744 | |
1307c758 RG |
2745 | /* With invalid code we can end up storing into the constant pool. |
2746 | Bail out to avoid ICEing when creating RTL for this. | |
2747 | See gfortran.dg/lto/20091028-2_0.f90. */ | |
2748 | if (TREE_CODE (exprx) == CONST_DECL | |
2749 | || TREE_CODE (expry) == CONST_DECL) | |
2750 | return 1; | |
2751 | ||
dca16798 JJ |
2752 | /* If one decl is known to be a function or label in a function and |
2753 | the other is some kind of data, they can't overlap. */ | |
2754 | if ((TREE_CODE (exprx) == FUNCTION_DECL | |
2755 | || TREE_CODE (exprx) == LABEL_DECL) | |
2756 | != (TREE_CODE (expry) == FUNCTION_DECL | |
2757 | || TREE_CODE (expry) == LABEL_DECL)) | |
2758 | return 1; | |
2759 | ||
5f4cebba JJ |
2760 | /* If either of the decls doesn't have DECL_RTL set (e.g. marked as |
2761 | living in multiple places), we can't tell anything. Exception | |
2762 | are FUNCTION_DECLs for which we can create DECL_RTL on demand. */ | |
2763 | if ((!DECL_RTL_SET_P (exprx) && TREE_CODE (exprx) != FUNCTION_DECL) | |
2764 | || (!DECL_RTL_SET_P (expry) && TREE_CODE (expry) != FUNCTION_DECL)) | |
2765 | return 0; | |
2766 | ||
998d7deb RH |
2767 | rtlx = DECL_RTL (exprx); |
2768 | rtly = DECL_RTL (expry); | |
a4311dfe | 2769 | |
1edcd60b RK |
2770 | /* If either RTL is not a MEM, it must be a REG or CONCAT, meaning they |
2771 | can't overlap unless they are the same because we never reuse that part | |
2772 | of the stack frame used for locals for spilled pseudos. */ | |
3c0cb5de | 2773 | if ((!MEM_P (rtlx) || !MEM_P (rtly)) |
1edcd60b | 2774 | && ! rtx_equal_p (rtlx, rtly)) |
a4311dfe RK |
2775 | return 1; |
2776 | ||
5932a4d4 | 2777 | /* If we have MEMs referring to different address spaces (which can |
09e881c9 BE |
2778 | potentially overlap), we cannot easily tell from the addresses |
2779 | whether the references overlap. */ | |
2780 | if (MEM_P (rtlx) && MEM_P (rtly) | |
2781 | && MEM_ADDR_SPACE (rtlx) != MEM_ADDR_SPACE (rtly)) | |
2782 | return 0; | |
2783 | ||
a4311dfe RK |
2784 | /* Get the base and offsets of both decls. If either is a register, we |
2785 | know both are and are the same, so use that as the base. The only | |
2786 | we can avoid overlap is if we can deduce that they are nonoverlapping | |
2787 | pieces of that decl, which is very rare. */ | |
3c0cb5de | 2788 | basex = MEM_P (rtlx) ? XEXP (rtlx, 0) : rtlx; |
481683e1 | 2789 | if (GET_CODE (basex) == PLUS && CONST_INT_P (XEXP (basex, 1))) |
a4311dfe RK |
2790 | offsetx = INTVAL (XEXP (basex, 1)), basex = XEXP (basex, 0); |
2791 | ||
3c0cb5de | 2792 | basey = MEM_P (rtly) ? XEXP (rtly, 0) : rtly; |
481683e1 | 2793 | if (GET_CODE (basey) == PLUS && CONST_INT_P (XEXP (basey, 1))) |
a4311dfe RK |
2794 | offsety = INTVAL (XEXP (basey, 1)), basey = XEXP (basey, 0); |
2795 | ||
d746694a | 2796 | /* If the bases are different, we know they do not overlap if both |
ca7fd9cd | 2797 | are constants or if one is a constant and the other a pointer into the |
d746694a RK |
2798 | stack frame. Otherwise a different base means we can't tell if they |
2799 | overlap or not. */ | |
54363f8a | 2800 | if (compare_base_decls (exprx, expry) == 0) |
ca7fd9cd KH |
2801 | return ((CONSTANT_P (basex) && CONSTANT_P (basey)) |
2802 | || (CONSTANT_P (basex) && REG_P (basey) | |
2803 | && REGNO_PTR_FRAME_P (REGNO (basey))) | |
2804 | || (CONSTANT_P (basey) && REG_P (basex) | |
2805 | && REGNO_PTR_FRAME_P (REGNO (basex)))); | |
a4311dfe | 2806 | |
c6ea834c BM |
2807 | /* Offset based disambiguation not appropriate for loop invariant */ |
2808 | if (loop_invariant) | |
dca16798 | 2809 | return 0; |
c6ea834c | 2810 | |
54363f8a JH |
2811 | /* Offset based disambiguation is OK even if we do not know that the |
2812 | declarations are necessarily different | |
2813 | (i.e. compare_base_decls (exprx, expry) == -1) */ | |
2814 | ||
3c0cb5de | 2815 | sizex = (!MEM_P (rtlx) ? (int) GET_MODE_SIZE (GET_MODE (rtlx)) |
f5541398 | 2816 | : MEM_SIZE_KNOWN_P (rtlx) ? MEM_SIZE (rtlx) |
a4311dfe | 2817 | : -1); |
3c0cb5de | 2818 | sizey = (!MEM_P (rtly) ? (int) GET_MODE_SIZE (GET_MODE (rtly)) |
f5541398 RS |
2819 | : MEM_SIZE_KNOWN_P (rtly) ? MEM_SIZE (rtly) |
2820 | : -1); | |
a4311dfe | 2821 | |
0af5bc3e RK |
2822 | /* If we have an offset for either memref, it can update the values computed |
2823 | above. */ | |
527210c4 RS |
2824 | if (moffsetx_known_p) |
2825 | offsetx += moffsetx, sizex -= moffsetx; | |
2826 | if (moffsety_known_p) | |
2827 | offsety += moffsety, sizey -= moffsety; | |
a4311dfe | 2828 | |
0af5bc3e | 2829 | /* If a memref has both a size and an offset, we can use the smaller size. |
efc981bb | 2830 | We can't do this if the offset isn't known because we must view this |
0af5bc3e | 2831 | memref as being anywhere inside the DECL's MEM. */ |
527210c4 | 2832 | if (MEM_SIZE_KNOWN_P (x) && moffsetx_known_p) |
f5541398 | 2833 | sizex = MEM_SIZE (x); |
527210c4 | 2834 | if (MEM_SIZE_KNOWN_P (y) && moffsety_known_p) |
f5541398 | 2835 | sizey = MEM_SIZE (y); |
a4311dfe RK |
2836 | |
2837 | /* Put the values of the memref with the lower offset in X's values. */ | |
2838 | if (offsetx > offsety) | |
2839 | { | |
4e1952ab KT |
2840 | std::swap (offsetx, offsety); |
2841 | std::swap (sizex, sizey); | |
a4311dfe RK |
2842 | } |
2843 | ||
2844 | /* If we don't know the size of the lower-offset value, we can't tell | |
2845 | if they conflict. Otherwise, we do the test. */ | |
a6f7c915 | 2846 | return sizex >= 0 && offsety >= offsetx + sizex; |
a4311dfe RK |
2847 | } |
2848 | ||
9362286d SB |
2849 | /* Helper for true_dependence and canon_true_dependence. |
2850 | Checks for true dependence: X is read after store in MEM takes place. | |
9ae8ffe7 | 2851 | |
9362286d SB |
2852 | If MEM_CANONICALIZED is FALSE, then X_ADDR and MEM_ADDR should be |
2853 | NULL_RTX, and the canonical addresses of MEM and X are both computed | |
2854 | here. If MEM_CANONICALIZED, then MEM must be already canonicalized. | |
2855 | ||
2856 | If X_ADDR is non-NULL, it is used in preference of XEXP (x, 0). | |
2857 | ||
2858 | Returns 1 if there is a true dependence, 0 otherwise. */ | |
2859 | ||
2860 | static int | |
ef4bddc2 | 2861 | true_dependence_1 (const_rtx mem, machine_mode mem_mode, rtx mem_addr, |
53d9622b | 2862 | const_rtx x, rtx x_addr, bool mem_canonicalized) |
9ae8ffe7 | 2863 | { |
0777fc02 | 2864 | rtx true_mem_addr; |
49982682 | 2865 | rtx base; |
f47e08d9 | 2866 | int ret; |
9ae8ffe7 | 2867 | |
9362286d SB |
2868 | gcc_checking_assert (mem_canonicalized ? (mem_addr != NULL_RTX) |
2869 | : (mem_addr == NULL_RTX && x_addr == NULL_RTX)); | |
2870 | ||
9ae8ffe7 JL |
2871 | if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) |
2872 | return 1; | |
2873 | ||
c4484b8f | 2874 | /* (mem:BLK (scratch)) is a special mechanism to conflict with everything. |
ac3768f6 | 2875 | This is used in epilogue deallocation functions, and in cselib. */ |
c4484b8f RH |
2876 | if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH) |
2877 | return 1; | |
2878 | if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH) | |
2879 | return 1; | |
9cd9e512 RH |
2880 | if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER |
2881 | || MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER) | |
2882 | return 1; | |
c4484b8f | 2883 | |
0777fc02 UB |
2884 | if (! x_addr) |
2885 | x_addr = XEXP (x, 0); | |
2886 | x_addr = get_addr (x_addr); | |
2887 | ||
9362286d SB |
2888 | if (! mem_addr) |
2889 | { | |
2890 | mem_addr = XEXP (mem, 0); | |
2891 | if (mem_mode == VOIDmode) | |
2892 | mem_mode = GET_MODE (mem); | |
2893 | } | |
0777fc02 | 2894 | true_mem_addr = get_addr (mem_addr); |
eab5c70a | 2895 | |
878f5596 UB |
2896 | /* Read-only memory is by definition never modified, and therefore can't |
2897 | conflict with anything. However, don't assume anything when AND | |
2898 | addresses are involved and leave to the code below to determine | |
2899 | dependence. We don't expect to find read-only set on MEM, but | |
2900 | stupid user tricks can produce them, so don't die. */ | |
2901 | if (MEM_READONLY_P (x) | |
2902 | && GET_CODE (x_addr) != AND | |
0777fc02 | 2903 | && GET_CODE (true_mem_addr) != AND) |
878f5596 UB |
2904 | return 0; |
2905 | ||
2906 | /* If we have MEMs referring to different address spaces (which can | |
2907 | potentially overlap), we cannot easily tell from the addresses | |
2908 | whether the references overlap. */ | |
2909 | if (MEM_ADDR_SPACE (mem) != MEM_ADDR_SPACE (x)) | |
2910 | return 1; | |
2911 | ||
55efb413 JW |
2912 | base = find_base_term (x_addr); |
2913 | if (base && (GET_CODE (base) == LABEL_REF | |
2914 | || (GET_CODE (base) == SYMBOL_REF | |
2915 | && CONSTANT_POOL_ADDRESS_P (base)))) | |
2916 | return 0; | |
2917 | ||
0777fc02 UB |
2918 | rtx mem_base = find_base_term (true_mem_addr); |
2919 | if (! base_alias_check (x_addr, base, true_mem_addr, mem_base, | |
31b0a960 | 2920 | GET_MODE (x), mem_mode)) |
1c72c7f6 JC |
2921 | return 0; |
2922 | ||
eab5c70a | 2923 | x_addr = canon_rtx (x_addr); |
9362286d | 2924 | if (!mem_canonicalized) |
0777fc02 | 2925 | mem_addr = canon_rtx (true_mem_addr); |
6e73e666 | 2926 | |
f47e08d9 RG |
2927 | if ((ret = memrefs_conflict_p (GET_MODE_SIZE (mem_mode), mem_addr, |
2928 | SIZE_FOR_MODE (x), x_addr, 0)) != -1) | |
2929 | return ret; | |
2930 | ||
a95b3cc7 | 2931 | if (mems_in_disjoint_alias_sets_p (x, mem)) |
f47e08d9 RG |
2932 | return 0; |
2933 | ||
c6ea834c | 2934 | if (nonoverlapping_memrefs_p (mem, x, false)) |
0211b6ab | 2935 | return 0; |
175a7536 | 2936 | |
55b34b5f | 2937 | return rtx_refs_may_alias_p (x, mem, true); |
a13d4ebf AM |
2938 | } |
2939 | ||
9362286d SB |
2940 | /* True dependence: X is read after store in MEM takes place. */ |
2941 | ||
2942 | int | |
ef4bddc2 | 2943 | true_dependence (const_rtx mem, machine_mode mem_mode, const_rtx x) |
9362286d SB |
2944 | { |
2945 | return true_dependence_1 (mem, mem_mode, NULL_RTX, | |
53d9622b | 2946 | x, NULL_RTX, /*mem_canonicalized=*/false); |
9362286d SB |
2947 | } |
2948 | ||
a13d4ebf | 2949 | /* Canonical true dependence: X is read after store in MEM takes place. |
ca7fd9cd KH |
2950 | Variant of true_dependence which assumes MEM has already been |
2951 | canonicalized (hence we no longer do that here). | |
9362286d SB |
2952 | The mem_addr argument has been added, since true_dependence_1 computed |
2953 | this value prior to canonicalizing. */ | |
a13d4ebf AM |
2954 | |
2955 | int | |
ef4bddc2 | 2956 | canon_true_dependence (const_rtx mem, machine_mode mem_mode, rtx mem_addr, |
53d9622b | 2957 | const_rtx x, rtx x_addr) |
a13d4ebf | 2958 | { |
9362286d | 2959 | return true_dependence_1 (mem, mem_mode, mem_addr, |
53d9622b | 2960 | x, x_addr, /*mem_canonicalized=*/true); |
9ae8ffe7 JL |
2961 | } |
2962 | ||
da7d8304 | 2963 | /* Returns nonzero if a write to X might alias a previous read from |
393f9fed | 2964 | (or, if WRITEP is true, a write to) MEM. |
bd280792 JR |
2965 | If X_CANONCALIZED is true, then X_ADDR is the canonicalized address of X, |
2966 | and X_MODE the mode for that access. | |
2967 | If MEM_CANONICALIZED is true, MEM is canonicalized. */ | |
9ae8ffe7 | 2968 | |
2c72b78f | 2969 | static int |
bd280792 | 2970 | write_dependence_p (const_rtx mem, |
ef4bddc2 | 2971 | const_rtx x, machine_mode x_mode, rtx x_addr, |
bd280792 | 2972 | bool mem_canonicalized, bool x_canonicalized, bool writep) |
9ae8ffe7 | 2973 | { |
bd280792 | 2974 | rtx mem_addr; |
0777fc02 | 2975 | rtx true_mem_addr, true_x_addr; |
49982682 | 2976 | rtx base; |
f47e08d9 | 2977 | int ret; |
6e73e666 | 2978 | |
bd280792 JR |
2979 | gcc_checking_assert (x_canonicalized |
2980 | ? (x_addr != NULL_RTX && x_mode != VOIDmode) | |
2981 | : (x_addr == NULL_RTX && x_mode == VOIDmode)); | |
393f9fed | 2982 | |
9ae8ffe7 JL |
2983 | if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) |
2984 | return 1; | |
2985 | ||
c4484b8f RH |
2986 | /* (mem:BLK (scratch)) is a special mechanism to conflict with everything. |
2987 | This is used in epilogue deallocation functions. */ | |
2988 | if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH) | |
2989 | return 1; | |
2990 | if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH) | |
2991 | return 1; | |
9cd9e512 RH |
2992 | if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER |
2993 | || MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER) | |
2994 | return 1; | |
c4484b8f | 2995 | |
bd280792 | 2996 | if (!x_addr) |
0777fc02 UB |
2997 | x_addr = XEXP (x, 0); |
2998 | true_x_addr = get_addr (x_addr); | |
2999 | ||
3000 | mem_addr = XEXP (mem, 0); | |
3001 | true_mem_addr = get_addr (mem_addr); | |
55efb413 | 3002 | |
878f5596 UB |
3003 | /* A read from read-only memory can't conflict with read-write memory. |
3004 | Don't assume anything when AND addresses are involved and leave to | |
3005 | the code below to determine dependence. */ | |
3006 | if (!writep | |
3007 | && MEM_READONLY_P (mem) | |
0777fc02 UB |
3008 | && GET_CODE (true_x_addr) != AND |
3009 | && GET_CODE (true_mem_addr) != AND) | |
878f5596 UB |
3010 | return 0; |
3011 | ||
3012 | /* If we have MEMs referring to different address spaces (which can | |
3013 | potentially overlap), we cannot easily tell from the addresses | |
3014 | whether the references overlap. */ | |
3015 | if (MEM_ADDR_SPACE (mem) != MEM_ADDR_SPACE (x)) | |
3016 | return 1; | |
3017 | ||
0777fc02 | 3018 | base = find_base_term (true_mem_addr); |
31b0a960 RB |
3019 | if (! writep |
3020 | && base | |
3021 | && (GET_CODE (base) == LABEL_REF | |
3022 | || (GET_CODE (base) == SYMBOL_REF | |
3023 | && CONSTANT_POOL_ADDRESS_P (base)))) | |
3024 | return 0; | |
49982682 | 3025 | |
0777fc02 UB |
3026 | rtx x_base = find_base_term (true_x_addr); |
3027 | if (! base_alias_check (true_x_addr, x_base, true_mem_addr, base, | |
3028 | GET_MODE (x), GET_MODE (mem))) | |
41472af8 MM |
3029 | return 0; |
3030 | ||
bd280792 | 3031 | if (!x_canonicalized) |
393f9fed | 3032 | { |
0777fc02 | 3033 | x_addr = canon_rtx (true_x_addr); |
bd280792 | 3034 | x_mode = GET_MODE (x); |
393f9fed | 3035 | } |
bd280792 | 3036 | if (!mem_canonicalized) |
0777fc02 | 3037 | mem_addr = canon_rtx (true_mem_addr); |
6e73e666 | 3038 | |
bd280792 JR |
3039 | if ((ret = memrefs_conflict_p (SIZE_FOR_MODE (mem), mem_addr, |
3040 | GET_MODE_SIZE (x_mode), x_addr, 0)) != -1) | |
f47e08d9 RG |
3041 | return ret; |
3042 | ||
c6ea834c | 3043 | if (nonoverlapping_memrefs_p (x, mem, false)) |
c6df88cb MM |
3044 | return 0; |
3045 | ||
55b34b5f | 3046 | return rtx_refs_may_alias_p (x, mem, false); |
c6df88cb MM |
3047 | } |
3048 | ||
3049 | /* Anti dependence: X is written after read in MEM takes place. */ | |
3050 | ||
3051 | int | |
4f588890 | 3052 | anti_dependence (const_rtx mem, const_rtx x) |
c6df88cb | 3053 | { |
bd280792 JR |
3054 | return write_dependence_p (mem, x, VOIDmode, NULL_RTX, |
3055 | /*mem_canonicalized=*/false, | |
3056 | /*x_canonicalized*/false, /*writep=*/false); | |
393f9fed JR |
3057 | } |
3058 | ||
bd280792 JR |
3059 | /* Likewise, but we already have a canonicalized MEM, and X_ADDR for X. |
3060 | Also, consider X in X_MODE (which might be from an enclosing | |
3061 | STRICT_LOW_PART / ZERO_EXTRACT). | |
3062 | If MEM_CANONICALIZED is true, MEM is canonicalized. */ | |
393f9fed JR |
3063 | |
3064 | int | |
bd280792 | 3065 | canon_anti_dependence (const_rtx mem, bool mem_canonicalized, |
ef4bddc2 | 3066 | const_rtx x, machine_mode x_mode, rtx x_addr) |
393f9fed | 3067 | { |
bd280792 JR |
3068 | return write_dependence_p (mem, x, x_mode, x_addr, |
3069 | mem_canonicalized, /*x_canonicalized=*/true, | |
3070 | /*writep=*/false); | |
9ae8ffe7 JL |
3071 | } |
3072 | ||
3073 | /* Output dependence: X is written after store in MEM takes place. */ | |
3074 | ||
3075 | int | |
4f588890 | 3076 | output_dependence (const_rtx mem, const_rtx x) |
9ae8ffe7 | 3077 | { |
bd280792 JR |
3078 | return write_dependence_p (mem, x, VOIDmode, NULL_RTX, |
3079 | /*mem_canonicalized=*/false, | |
3080 | /*x_canonicalized*/false, /*writep=*/true); | |
9ae8ffe7 | 3081 | } |
43b9f499 RB |
3082 | |
3083 | /* Likewise, but we already have a canonicalized MEM, and X_ADDR for X. | |
3084 | Also, consider X in X_MODE (which might be from an enclosing | |
3085 | STRICT_LOW_PART / ZERO_EXTRACT). | |
3086 | If MEM_CANONICALIZED is true, MEM is canonicalized. */ | |
3087 | ||
3088 | int | |
3089 | canon_output_dependence (const_rtx mem, bool mem_canonicalized, | |
3090 | const_rtx x, machine_mode x_mode, rtx x_addr) | |
3091 | { | |
3092 | return write_dependence_p (mem, x, x_mode, x_addr, | |
3093 | mem_canonicalized, /*x_canonicalized=*/true, | |
3094 | /*writep=*/true); | |
3095 | } | |
c14b9960 | 3096 | \f |
6e73e666 | 3097 | |
c6ea834c BM |
3098 | |
3099 | /* Check whether X may be aliased with MEM. Don't do offset-based | |
3100 | memory disambiguation & TBAA. */ | |
3101 | int | |
3102 | may_alias_p (const_rtx mem, const_rtx x) | |
3103 | { | |
3104 | rtx x_addr, mem_addr; | |
c6ea834c BM |
3105 | |
3106 | if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) | |
3107 | return 1; | |
3108 | ||
a95b3cc7 RG |
3109 | /* (mem:BLK (scratch)) is a special mechanism to conflict with everything. |
3110 | This is used in epilogue deallocation functions. */ | |
3111 | if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH) | |
3112 | return 1; | |
3113 | if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH) | |
c6ea834c | 3114 | return 1; |
c6ea834c BM |
3115 | if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER |
3116 | || MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER) | |
3117 | return 1; | |
3118 | ||
c6ea834c | 3119 | x_addr = XEXP (x, 0); |
0777fc02 UB |
3120 | x_addr = get_addr (x_addr); |
3121 | ||
c6ea834c | 3122 | mem_addr = XEXP (mem, 0); |
0777fc02 | 3123 | mem_addr = get_addr (mem_addr); |
c6ea834c | 3124 | |
878f5596 UB |
3125 | /* Read-only memory is by definition never modified, and therefore can't |
3126 | conflict with anything. However, don't assume anything when AND | |
3127 | addresses are involved and leave to the code below to determine | |
3128 | dependence. We don't expect to find read-only set on MEM, but | |
3129 | stupid user tricks can produce them, so don't die. */ | |
3130 | if (MEM_READONLY_P (x) | |
3131 | && GET_CODE (x_addr) != AND | |
3132 | && GET_CODE (mem_addr) != AND) | |
3133 | return 0; | |
3134 | ||
3135 | /* If we have MEMs referring to different address spaces (which can | |
3136 | potentially overlap), we cannot easily tell from the addresses | |
3137 | whether the references overlap. */ | |
3138 | if (MEM_ADDR_SPACE (mem) != MEM_ADDR_SPACE (x)) | |
3139 | return 1; | |
3140 | ||
31b0a960 RB |
3141 | rtx x_base = find_base_term (x_addr); |
3142 | rtx mem_base = find_base_term (mem_addr); | |
3143 | if (! base_alias_check (x_addr, x_base, mem_addr, mem_base, | |
3144 | GET_MODE (x), GET_MODE (mem_addr))) | |
c6ea834c BM |
3145 | return 0; |
3146 | ||
c6ea834c BM |
3147 | if (nonoverlapping_memrefs_p (mem, x, true)) |
3148 | return 0; | |
3149 | ||
c6ea834c BM |
3150 | /* TBAA not valid for loop_invarint */ |
3151 | return rtx_refs_may_alias_p (x, mem, false); | |
3152 | } | |
3153 | ||
6e73e666 | 3154 | void |
b5deb7b6 | 3155 | init_alias_target (void) |
6e73e666 | 3156 | { |
b3694847 | 3157 | int i; |
6e73e666 | 3158 | |
9fc37b2b RS |
3159 | if (!arg_base_value) |
3160 | arg_base_value = gen_rtx_ADDRESS (VOIDmode, 0); | |
3161 | ||
b5deb7b6 SL |
3162 | memset (static_reg_base_value, 0, sizeof static_reg_base_value); |
3163 | ||
6e73e666 JC |
3164 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) |
3165 | /* Check whether this register can hold an incoming pointer | |
3166 | argument. FUNCTION_ARG_REGNO_P tests outgoing register | |
ec5c56db | 3167 | numbers, so translate if necessary due to register windows. */ |
6e73e666 JC |
3168 | if (FUNCTION_ARG_REGNO_P (OUTGOING_REGNO (i)) |
3169 | && HARD_REGNO_MODE_OK (i, Pmode)) | |
9fc37b2b RS |
3170 | static_reg_base_value[i] = arg_base_value; |
3171 | ||
757e8ba2 JJ |
3172 | static_reg_base_value[STACK_POINTER_REGNUM] |
3173 | = unique_base_value (UNIQUE_BASE_VALUE_SP); | |
3174 | static_reg_base_value[ARG_POINTER_REGNUM] | |
3175 | = unique_base_value (UNIQUE_BASE_VALUE_ARGP); | |
3176 | static_reg_base_value[FRAME_POINTER_REGNUM] | |
3177 | = unique_base_value (UNIQUE_BASE_VALUE_FP); | |
c3e08036 TS |
3178 | if (!HARD_FRAME_POINTER_IS_FRAME_POINTER) |
3179 | static_reg_base_value[HARD_FRAME_POINTER_REGNUM] | |
3180 | = unique_base_value (UNIQUE_BASE_VALUE_HFP); | |
bf1660a6 JL |
3181 | } |
3182 | ||
7b52eede JH |
3183 | /* Set MEMORY_MODIFIED when X modifies DATA (that is assumed |
3184 | to be memory reference. */ | |
3185 | static bool memory_modified; | |
3186 | static void | |
aa317c97 | 3187 | memory_modified_1 (rtx x, const_rtx pat ATTRIBUTE_UNUSED, void *data) |
7b52eede | 3188 | { |
3c0cb5de | 3189 | if (MEM_P (x)) |
7b52eede | 3190 | { |
9678086d | 3191 | if (anti_dependence (x, (const_rtx)data) || output_dependence (x, (const_rtx)data)) |
7b52eede JH |
3192 | memory_modified = true; |
3193 | } | |
3194 | } | |
3195 | ||
3196 | ||
3197 | /* Return true when INSN possibly modify memory contents of MEM | |
454ff5cb | 3198 | (i.e. address can be modified). */ |
7b52eede | 3199 | bool |
9678086d | 3200 | memory_modified_in_insn_p (const_rtx mem, const_rtx insn) |
7b52eede JH |
3201 | { |
3202 | if (!INSN_P (insn)) | |
3203 | return false; | |
3204 | memory_modified = false; | |
aa317c97 | 3205 | note_stores (PATTERN (insn), memory_modified_1, CONST_CAST_RTX(mem)); |
7b52eede JH |
3206 | return memory_modified; |
3207 | } | |
3208 | ||
a7b159a4 AH |
3209 | /* Return TRUE if the destination of a set is rtx identical to |
3210 | ITEM. */ | |
3211 | static inline bool | |
3212 | set_dest_equal_p (const_rtx set, const_rtx item) | |
3213 | { | |
3214 | rtx dest = SET_DEST (set); | |
3215 | return rtx_equal_p (dest, item); | |
3216 | } | |
3217 | ||
c13e8210 MM |
3218 | /* Initialize the aliasing machinery. Initialize the REG_KNOWN_VALUE |
3219 | array. */ | |
3220 | ||
9ae8ffe7 | 3221 | void |
4682ae04 | 3222 | init_alias_analysis (void) |
9ae8ffe7 | 3223 | { |
c582d54a | 3224 | unsigned int maxreg = max_reg_num (); |
ea64ef27 | 3225 | int changed, pass; |
b3694847 SS |
3226 | int i; |
3227 | unsigned int ui; | |
d36a28b8 DM |
3228 | rtx_insn *insn; |
3229 | rtx val; | |
131db6b8 SB |
3230 | int rpo_cnt; |
3231 | int *rpo; | |
9ae8ffe7 | 3232 | |
0d446150 JH |
3233 | timevar_push (TV_ALIAS_ANALYSIS); |
3234 | ||
92390dd1 | 3235 | vec_safe_grow_cleared (reg_known_value, maxreg - FIRST_PSEUDO_REGISTER); |
9ff3c7ca | 3236 | reg_known_equiv_p = sbitmap_alloc (maxreg - FIRST_PSEUDO_REGISTER); |
dd3d1ec0 | 3237 | bitmap_clear (reg_known_equiv_p); |
9ae8ffe7 | 3238 | |
08c79682 | 3239 | /* If we have memory allocated from the previous run, use it. */ |
c582d54a | 3240 | if (old_reg_base_value) |
08c79682 KH |
3241 | reg_base_value = old_reg_base_value; |
3242 | ||
3243 | if (reg_base_value) | |
9771b263 | 3244 | reg_base_value->truncate (0); |
08c79682 | 3245 | |
9771b263 | 3246 | vec_safe_grow_cleared (reg_base_value, maxreg); |
ac606739 | 3247 | |
5ed6ace5 | 3248 | new_reg_base_value = XNEWVEC (rtx, maxreg); |
d630245f | 3249 | reg_seen = sbitmap_alloc (maxreg); |
ec907dd8 JL |
3250 | |
3251 | /* The basic idea is that each pass through this loop will use the | |
3252 | "constant" information from the previous pass to propagate alias | |
3253 | information through another level of assignments. | |
3254 | ||
131db6b8 SB |
3255 | The propagation is done on the CFG in reverse post-order, to propagate |
3256 | things forward as far as possible in each iteration. | |
3257 | ||
ec907dd8 JL |
3258 | This could get expensive if the assignment chains are long. Maybe |
3259 | we should throttle the number of iterations, possibly based on | |
6e73e666 | 3260 | the optimization level or flag_expensive_optimizations. |
ec907dd8 JL |
3261 | |
3262 | We could propagate more information in the first pass by making use | |
6fb5fa3c | 3263 | of DF_REG_DEF_COUNT to determine immediately that the alias information |
ea64ef27 JL |
3264 | for a pseudo is "constant". |
3265 | ||
3266 | A program with an uninitialized variable can cause an infinite loop | |
3267 | here. Instead of doing a full dataflow analysis to detect such problems | |
3268 | we just cap the number of iterations for the loop. | |
3269 | ||
3270 | The state of the arrays for the set chain in question does not matter | |
3271 | since the program has undefined behavior. */ | |
6e73e666 | 3272 | |
0cae8d31 | 3273 | rpo = XNEWVEC (int, n_basic_blocks_for_fn (cfun)); |
131db6b8 SB |
3274 | rpo_cnt = pre_and_rev_post_order_compute (NULL, rpo, false); |
3275 | ||
e86a9946 RS |
3276 | /* The prologue/epilogue insns are not threaded onto the |
3277 | insn chain until after reload has completed. Thus, | |
3278 | there is no sense wasting time checking if INSN is in | |
3279 | the prologue/epilogue until after reload has completed. */ | |
3280 | bool could_be_prologue_epilogue = ((targetm.have_prologue () | |
3281 | || targetm.have_epilogue ()) | |
3282 | && reload_completed); | |
3283 | ||
ea64ef27 | 3284 | pass = 0; |
6e73e666 | 3285 | do |
ec907dd8 JL |
3286 | { |
3287 | /* Assume nothing will change this iteration of the loop. */ | |
3288 | changed = 0; | |
3289 | ||
ec907dd8 | 3290 | /* We want to assign the same IDs each iteration of this loop, so |
9fc37b2b RS |
3291 | start counting from one each iteration of the loop. */ |
3292 | unique_id = 1; | |
ec907dd8 | 3293 | |
f5143c46 | 3294 | /* We're at the start of the function each iteration through the |
ec907dd8 | 3295 | loop, so we're copying arguments. */ |
83bbd9b6 | 3296 | copying_arguments = true; |
9ae8ffe7 | 3297 | |
6e73e666 | 3298 | /* Wipe the potential alias information clean for this pass. */ |
c582d54a | 3299 | memset (new_reg_base_value, 0, maxreg * sizeof (rtx)); |
8072f69c | 3300 | |
6e73e666 | 3301 | /* Wipe the reg_seen array clean. */ |
f61e445a | 3302 | bitmap_clear (reg_seen); |
9ae8ffe7 | 3303 | |
356610cb EB |
3304 | /* Initialize the alias information for this pass. */ |
3305 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
3306 | if (static_reg_base_value[i]) | |
3307 | { | |
3308 | new_reg_base_value[i] = static_reg_base_value[i]; | |
3309 | bitmap_set_bit (reg_seen, i); | |
3310 | } | |
6e73e666 | 3311 | |
ec907dd8 | 3312 | /* Walk the insns adding values to the new_reg_base_value array. */ |
131db6b8 | 3313 | for (i = 0; i < rpo_cnt; i++) |
9ae8ffe7 | 3314 | { |
06e28de2 | 3315 | basic_block bb = BASIC_BLOCK_FOR_FN (cfun, rpo[i]); |
131db6b8 | 3316 | FOR_BB_INSNS (bb, insn) |
ec907dd8 | 3317 | { |
131db6b8 SB |
3318 | if (NONDEBUG_INSN_P (insn)) |
3319 | { | |
3320 | rtx note, set; | |
efc9bd41 | 3321 | |
e86a9946 | 3322 | if (could_be_prologue_epilogue |
131db6b8 SB |
3323 | && prologue_epilogue_contains (insn)) |
3324 | continue; | |
efc9bd41 | 3325 | |
131db6b8 SB |
3326 | /* If this insn has a noalias note, process it, Otherwise, |
3327 | scan for sets. A simple set will have no side effects | |
3328 | which could change the base value of any other register. */ | |
6e73e666 | 3329 | |
131db6b8 SB |
3330 | if (GET_CODE (PATTERN (insn)) == SET |
3331 | && REG_NOTES (insn) != 0 | |
3332 | && find_reg_note (insn, REG_NOALIAS, NULL_RTX)) | |
3333 | record_set (SET_DEST (PATTERN (insn)), NULL_RTX, NULL); | |
3334 | else | |
3335 | note_stores (PATTERN (insn), record_set, NULL); | |
6e73e666 | 3336 | |
131db6b8 | 3337 | set = single_set (insn); |
6e73e666 | 3338 | |
131db6b8 SB |
3339 | if (set != 0 |
3340 | && REG_P (SET_DEST (set)) | |
3341 | && REGNO (SET_DEST (set)) >= FIRST_PSEUDO_REGISTER) | |
713f41f9 | 3342 | { |
131db6b8 SB |
3343 | unsigned int regno = REGNO (SET_DEST (set)); |
3344 | rtx src = SET_SRC (set); | |
3345 | rtx t; | |
3346 | ||
3347 | note = find_reg_equal_equiv_note (insn); | |
3348 | if (note && REG_NOTE_KIND (note) == REG_EQUAL | |
3349 | && DF_REG_DEF_COUNT (regno) != 1) | |
3350 | note = NULL_RTX; | |
3351 | ||
3352 | if (note != NULL_RTX | |
3353 | && GET_CODE (XEXP (note, 0)) != EXPR_LIST | |
3354 | && ! rtx_varies_p (XEXP (note, 0), 1) | |
3355 | && ! reg_overlap_mentioned_p (SET_DEST (set), | |
3356 | XEXP (note, 0))) | |
3357 | { | |
3358 | set_reg_known_value (regno, XEXP (note, 0)); | |
3359 | set_reg_known_equiv_p (regno, | |
3360 | REG_NOTE_KIND (note) == REG_EQUIV); | |
3361 | } | |
3362 | else if (DF_REG_DEF_COUNT (regno) == 1 | |
3363 | && GET_CODE (src) == PLUS | |
3364 | && REG_P (XEXP (src, 0)) | |
3365 | && (t = get_reg_known_value (REGNO (XEXP (src, 0)))) | |
3366 | && CONST_INT_P (XEXP (src, 1))) | |
3367 | { | |
3368 | t = plus_constant (GET_MODE (src), t, | |
3369 | INTVAL (XEXP (src, 1))); | |
3370 | set_reg_known_value (regno, t); | |
3371 | set_reg_known_equiv_p (regno, false); | |
3372 | } | |
3373 | else if (DF_REG_DEF_COUNT (regno) == 1 | |
3374 | && ! rtx_varies_p (src, 1)) | |
3375 | { | |
3376 | set_reg_known_value (regno, src); | |
3377 | set_reg_known_equiv_p (regno, false); | |
3378 | } | |
713f41f9 | 3379 | } |
6e73e666 | 3380 | } |
131db6b8 SB |
3381 | else if (NOTE_P (insn) |
3382 | && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG) | |
3383 | copying_arguments = false; | |
ec907dd8 | 3384 | } |
6e73e666 | 3385 | } |
ec907dd8 | 3386 | |
6e73e666 | 3387 | /* Now propagate values from new_reg_base_value to reg_base_value. */ |
62e5bf5d | 3388 | gcc_assert (maxreg == (unsigned int) max_reg_num ()); |
c22cacf3 | 3389 | |
c582d54a | 3390 | for (ui = 0; ui < maxreg; ui++) |
6e73e666 | 3391 | { |
e51712db | 3392 | if (new_reg_base_value[ui] |
9771b263 DN |
3393 | && new_reg_base_value[ui] != (*reg_base_value)[ui] |
3394 | && ! rtx_equal_p (new_reg_base_value[ui], (*reg_base_value)[ui])) | |
ec907dd8 | 3395 | { |
9771b263 | 3396 | (*reg_base_value)[ui] = new_reg_base_value[ui]; |
6e73e666 | 3397 | changed = 1; |
ec907dd8 | 3398 | } |
9ae8ffe7 | 3399 | } |
9ae8ffe7 | 3400 | } |
6e73e666 | 3401 | while (changed && ++pass < MAX_ALIAS_LOOP_PASSES); |
131db6b8 | 3402 | XDELETEVEC (rpo); |
9ae8ffe7 JL |
3403 | |
3404 | /* Fill in the remaining entries. */ | |
9771b263 | 3405 | FOR_EACH_VEC_ELT (*reg_known_value, i, val) |
9ff3c7ca SB |
3406 | { |
3407 | int regno = i + FIRST_PSEUDO_REGISTER; | |
3408 | if (! val) | |
3409 | set_reg_known_value (regno, regno_reg_rtx[regno]); | |
3410 | } | |
9ae8ffe7 | 3411 | |
e05e2395 MM |
3412 | /* Clean up. */ |
3413 | free (new_reg_base_value); | |
ec907dd8 | 3414 | new_reg_base_value = 0; |
d630245f | 3415 | sbitmap_free (reg_seen); |
9ae8ffe7 | 3416 | reg_seen = 0; |
0d446150 | 3417 | timevar_pop (TV_ALIAS_ANALYSIS); |
9ae8ffe7 JL |
3418 | } |
3419 | ||
61630b27 JJ |
3420 | /* Equate REG_BASE_VALUE (reg1) to REG_BASE_VALUE (reg2). |
3421 | Special API for var-tracking pass purposes. */ | |
3422 | ||
3423 | void | |
3424 | vt_equate_reg_base_value (const_rtx reg1, const_rtx reg2) | |
3425 | { | |
9771b263 | 3426 | (*reg_base_value)[REGNO (reg1)] = REG_BASE_VALUE (reg2); |
61630b27 JJ |
3427 | } |
3428 | ||
9ae8ffe7 | 3429 | void |
4682ae04 | 3430 | end_alias_analysis (void) |
9ae8ffe7 | 3431 | { |
c582d54a | 3432 | old_reg_base_value = reg_base_value; |
9771b263 | 3433 | vec_free (reg_known_value); |
9ff3c7ca | 3434 | sbitmap_free (reg_known_equiv_p); |
9ae8ffe7 | 3435 | } |
e2500fed | 3436 | |
3ecf9d13 JH |
3437 | void |
3438 | dump_alias_stats_in_alias_c (FILE *s) | |
3439 | { | |
3440 | fprintf (s, " TBAA oracle: %llu disambiguations %llu queries\n" | |
3441 | " %llu are in alias set 0\n" | |
3442 | " %llu queries asked about the same object\n" | |
3443 | " %llu queries asked about the same alias set\n" | |
3444 | " %llu access volatile\n" | |
6e042ef4 JH |
3445 | " %llu are dependent in the DAG\n" |
3446 | " %llu are aritificially in conflict with void *\n", | |
3ecf9d13 JH |
3447 | alias_stats.num_disambiguated, |
3448 | alias_stats.num_alias_zero + alias_stats.num_same_alias_set | |
3449 | + alias_stats.num_same_objects + alias_stats.num_volatile | |
6e042ef4 JH |
3450 | + alias_stats.num_dag + alias_stats.num_disambiguated |
3451 | + alias_stats.num_universal, | |
3ecf9d13 | 3452 | alias_stats.num_alias_zero, alias_stats.num_same_alias_set, |
6e042ef4 JH |
3453 | alias_stats.num_same_objects, alias_stats.num_volatile, |
3454 | alias_stats.num_dag, alias_stats.num_universal); | |
3ecf9d13 | 3455 | } |
e2500fed | 3456 | #include "gt-alias.h" |