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9ae8ffe7 | 1 | /* Alias analysis for GNU C |
d1e082c2 | 2 | Copyright (C) 1997-2013 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 ZW |
23 | #include "coretypes.h" |
24 | #include "tm.h" | |
9ae8ffe7 | 25 | #include "rtl.h" |
7790df19 | 26 | #include "tree.h" |
6baf1cc8 | 27 | #include "tm_p.h" |
49ad7cfa | 28 | #include "function.h" |
78528714 JQ |
29 | #include "alias.h" |
30 | #include "emit-rtl.h" | |
9ae8ffe7 JL |
31 | #include "regs.h" |
32 | #include "hard-reg-set.h" | |
e004f2f7 | 33 | #include "basic-block.h" |
9ae8ffe7 | 34 | #include "flags.h" |
718f9c0f | 35 | #include "diagnostic-core.h" |
eab5c70a | 36 | #include "cselib.h" |
3932261a | 37 | #include "splay-tree.h" |
ac606739 | 38 | #include "ggc.h" |
d23c55c2 | 39 | #include "langhooks.h" |
0d446150 | 40 | #include "timevar.h" |
7ee2468b | 41 | #include "dumpfile.h" |
ab780373 | 42 | #include "target.h" |
6fb5fa3c | 43 | #include "df.h" |
55b34b5f RG |
44 | #include "tree-ssa-alias.h" |
45 | #include "pointer-set.h" | |
442b4905 AM |
46 | #include "gimple.h" |
47 | #include "gimple-ssa.h" | |
ea900239 DB |
48 | |
49 | /* The aliasing API provided here solves related but different problems: | |
50 | ||
c22cacf3 | 51 | Say there exists (in c) |
ea900239 DB |
52 | |
53 | struct X { | |
54 | struct Y y1; | |
55 | struct Z z2; | |
56 | } x1, *px1, *px2; | |
57 | ||
58 | struct Y y2, *py; | |
59 | struct Z z2, *pz; | |
60 | ||
61 | ||
308a3fe2 | 62 | py = &x1.y1; |
ea900239 DB |
63 | px2 = &x1; |
64 | ||
65 | Consider the four questions: | |
66 | ||
67 | Can a store to x1 interfere with px2->y1? | |
68 | Can a store to x1 interfere with px2->z2? | |
ea900239 DB |
69 | Can a store to x1 change the value pointed to by with py? |
70 | Can a store to x1 change the value pointed to by with pz? | |
71 | ||
72 | The answer to these questions can be yes, yes, yes, and maybe. | |
73 | ||
74 | The first two questions can be answered with a simple examination | |
75 | of the type system. If structure X contains a field of type Y then | |
073a8998 | 76 | a store through a pointer to an X can overwrite any field that is |
ea900239 DB |
77 | contained (recursively) in an X (unless we know that px1 != px2). |
78 | ||
308a3fe2 DS |
79 | The last two questions can be solved in the same way as the first |
80 | two questions but this is too conservative. The observation is | |
81 | that in some cases we can know which (if any) fields are addressed | |
82 | and if those addresses are used in bad ways. This analysis may be | |
83 | language specific. In C, arbitrary operations may be applied to | |
84 | pointers. However, there is some indication that this may be too | |
85 | conservative for some C++ types. | |
ea900239 DB |
86 | |
87 | The pass ipa-type-escape does this analysis for the types whose | |
c22cacf3 | 88 | instances do not escape across the compilation boundary. |
ea900239 DB |
89 | |
90 | Historically in GCC, these two problems were combined and a single | |
308a3fe2 | 91 | data structure that was used to represent the solution to these |
ea900239 | 92 | problems. We now have two similar but different data structures, |
308a3fe2 DS |
93 | The data structure to solve the last two questions is similar to |
94 | the first, but does not contain the fields whose address are never | |
95 | taken. For types that do escape the compilation unit, the data | |
96 | structures will have identical information. | |
ea900239 | 97 | */ |
3932261a MM |
98 | |
99 | /* The alias sets assigned to MEMs assist the back-end in determining | |
100 | which MEMs can alias which other MEMs. In general, two MEMs in | |
ac3d9668 RK |
101 | different alias sets cannot alias each other, with one important |
102 | exception. Consider something like: | |
3932261a | 103 | |
01d28c3f | 104 | struct S { int i; double d; }; |
3932261a MM |
105 | |
106 | a store to an `S' can alias something of either type `int' or type | |
107 | `double'. (However, a store to an `int' cannot alias a `double' | |
108 | and vice versa.) We indicate this via a tree structure that looks | |
109 | like: | |
c22cacf3 MS |
110 | struct S |
111 | / \ | |
3932261a | 112 | / \ |
c22cacf3 MS |
113 | |/_ _\| |
114 | int double | |
3932261a | 115 | |
ac3d9668 RK |
116 | (The arrows are directed and point downwards.) |
117 | In this situation we say the alias set for `struct S' is the | |
118 | `superset' and that those for `int' and `double' are `subsets'. | |
119 | ||
3bdf5ad1 RK |
120 | To see whether two alias sets can point to the same memory, we must |
121 | see if either alias set is a subset of the other. We need not trace | |
95bd1dd7 | 122 | past immediate descendants, however, since we propagate all |
3bdf5ad1 | 123 | grandchildren up one level. |
3932261a MM |
124 | |
125 | Alias set zero is implicitly a superset of all other alias sets. | |
126 | However, this is no actual entry for alias set zero. It is an | |
127 | error to attempt to explicitly construct a subset of zero. */ | |
128 | ||
7e5487a2 | 129 | struct GTY(()) alias_set_entry_d { |
3932261a | 130 | /* The alias set number, as stored in MEM_ALIAS_SET. */ |
4862826d | 131 | alias_set_type alias_set; |
3932261a | 132 | |
4c067742 RG |
133 | /* Nonzero if would have a child of zero: this effectively makes this |
134 | alias set the same as alias set zero. */ | |
135 | int has_zero_child; | |
136 | ||
3932261a | 137 | /* The children of the alias set. These are not just the immediate |
95bd1dd7 | 138 | children, but, in fact, all descendants. So, if we have: |
3932261a | 139 | |
ca7fd9cd | 140 | struct T { struct S s; float f; } |
3932261a MM |
141 | |
142 | continuing our example above, the children here will be all of | |
143 | `int', `double', `float', and `struct S'. */ | |
b604074c | 144 | splay_tree GTY((param1_is (int), param2_is (int))) children; |
b604074c | 145 | }; |
7e5487a2 | 146 | typedef struct alias_set_entry_d *alias_set_entry; |
9ae8ffe7 | 147 | |
ed7a4b4b | 148 | static int rtx_equal_for_memref_p (const_rtx, const_rtx); |
4682ae04 | 149 | static int memrefs_conflict_p (int, rtx, int, rtx, HOST_WIDE_INT); |
7bc980e1 | 150 | static void record_set (rtx, const_rtx, void *); |
31b0a960 | 151 | static int base_alias_check (rtx, rtx, rtx, rtx, enum machine_mode, |
4682ae04 AJ |
152 | enum machine_mode); |
153 | static rtx find_base_value (rtx); | |
4f588890 | 154 | static int mems_in_disjoint_alias_sets_p (const_rtx, const_rtx); |
4682ae04 | 155 | static int insert_subset_children (splay_tree_node, void*); |
4862826d | 156 | static alias_set_entry get_alias_set_entry (alias_set_type); |
175a7536 | 157 | static bool nonoverlapping_component_refs_p (const_rtx, const_rtx); |
4682ae04 | 158 | static tree decl_for_component_ref (tree); |
bd280792 JR |
159 | static int write_dependence_p (const_rtx, |
160 | const_rtx, enum machine_mode, rtx, | |
161 | bool, bool, bool); | |
4682ae04 | 162 | |
aa317c97 | 163 | static void memory_modified_1 (rtx, const_rtx, void *); |
9ae8ffe7 JL |
164 | |
165 | /* Set up all info needed to perform alias analysis on memory references. */ | |
166 | ||
d4b60170 | 167 | /* Returns the size in bytes of the mode of X. */ |
9ae8ffe7 JL |
168 | #define SIZE_FOR_MODE(X) (GET_MODE_SIZE (GET_MODE (X))) |
169 | ||
ea64ef27 | 170 | /* Cap the number of passes we make over the insns propagating alias |
131db6b8 SB |
171 | information through set chains. |
172 | ??? 10 is a completely arbitrary choice. This should be based on the | |
173 | maximum loop depth in the CFG, but we do not have this information | |
174 | available (even if current_loops _is_ available). */ | |
ea64ef27 | 175 | #define MAX_ALIAS_LOOP_PASSES 10 |
ca7fd9cd | 176 | |
9ae8ffe7 JL |
177 | /* reg_base_value[N] gives an address to which register N is related. |
178 | If all sets after the first add or subtract to the current value | |
179 | or otherwise modify it so it does not point to a different top level | |
180 | object, reg_base_value[N] is equal to the address part of the source | |
2a2c8203 JC |
181 | of the first set. |
182 | ||
183 | A base address can be an ADDRESS, SYMBOL_REF, or LABEL_REF. ADDRESS | |
9fc37b2b | 184 | expressions represent three types of base: |
b3b5ad95 | 185 | |
9fc37b2b RS |
186 | 1. incoming arguments. There is just one ADDRESS to represent all |
187 | arguments, since we do not know at this level whether accesses | |
188 | based on different arguments can alias. The ADDRESS has id 0. | |
b3b5ad95 | 189 | |
9fc37b2b RS |
190 | 2. stack_pointer_rtx, frame_pointer_rtx, hard_frame_pointer_rtx |
191 | (if distinct from frame_pointer_rtx) and arg_pointer_rtx. | |
192 | Each of these rtxes has a separate ADDRESS associated with it, | |
193 | each with a negative id. | |
194 | ||
195 | GCC is (and is required to be) precise in which register it | |
196 | chooses to access a particular region of stack. We can therefore | |
197 | assume that accesses based on one of these rtxes do not alias | |
198 | accesses based on another of these rtxes. | |
199 | ||
200 | 3. bases that are derived from malloc()ed memory (REG_NOALIAS). | |
201 | Each such piece of memory has a separate ADDRESS associated | |
202 | with it, each with an id greater than 0. | |
203 | ||
204 | Accesses based on one ADDRESS do not alias accesses based on other | |
205 | ADDRESSes. Accesses based on ADDRESSes in groups (2) and (3) do not | |
206 | alias globals either; the ADDRESSes have Pmode to indicate this. | |
207 | The ADDRESS in group (1) _may_ alias globals; it has VOIDmode to | |
208 | indicate this. */ | |
2a2c8203 | 209 | |
9771b263 | 210 | static GTY(()) vec<rtx, va_gc> *reg_base_value; |
ac606739 | 211 | static rtx *new_reg_base_value; |
c582d54a | 212 | |
9fc37b2b RS |
213 | /* The single VOIDmode ADDRESS that represents all argument bases. |
214 | It has id 0. */ | |
215 | static GTY(()) rtx arg_base_value; | |
216 | ||
217 | /* Used to allocate unique ids to each REG_NOALIAS ADDRESS. */ | |
218 | static int unique_id; | |
219 | ||
c582d54a JH |
220 | /* We preserve the copy of old array around to avoid amount of garbage |
221 | produced. About 8% of garbage produced were attributed to this | |
222 | array. */ | |
9771b263 | 223 | static GTY((deletable)) vec<rtx, va_gc> *old_reg_base_value; |
d4b60170 | 224 | |
9e412ca3 RS |
225 | /* Values of XINT (address, 0) of Pmode ADDRESS rtxes for special |
226 | registers. */ | |
227 | #define UNIQUE_BASE_VALUE_SP -1 | |
228 | #define UNIQUE_BASE_VALUE_ARGP -2 | |
229 | #define UNIQUE_BASE_VALUE_FP -3 | |
230 | #define UNIQUE_BASE_VALUE_HFP -4 | |
231 | ||
7bf84454 RS |
232 | #define static_reg_base_value \ |
233 | (this_target_rtl->x_static_reg_base_value) | |
bf1660a6 | 234 | |
9771b263 DN |
235 | #define REG_BASE_VALUE(X) \ |
236 | (REGNO (X) < vec_safe_length (reg_base_value) \ | |
237 | ? (*reg_base_value)[REGNO (X)] : 0) | |
9ae8ffe7 | 238 | |
c13e8210 | 239 | /* Vector indexed by N giving the initial (unchanging) value known for |
9ff3c7ca | 240 | pseudo-register N. This vector is initialized in init_alias_analysis, |
bb1acb3e | 241 | and does not change until end_alias_analysis is called. */ |
9771b263 | 242 | static GTY(()) vec<rtx, va_gc> *reg_known_value; |
9ae8ffe7 JL |
243 | |
244 | /* Vector recording for each reg_known_value whether it is due to a | |
245 | REG_EQUIV note. Future passes (viz., reload) may replace the | |
246 | pseudo with the equivalent expression and so we account for the | |
ac3d9668 RK |
247 | dependences that would be introduced if that happens. |
248 | ||
249 | The REG_EQUIV notes created in assign_parms may mention the arg | |
250 | pointer, and there are explicit insns in the RTL that modify the | |
251 | arg pointer. Thus we must ensure that such insns don't get | |
252 | scheduled across each other because that would invalidate the | |
253 | REG_EQUIV notes. One could argue that the REG_EQUIV notes are | |
254 | wrong, but solving the problem in the scheduler will likely give | |
255 | better code, so we do it here. */ | |
9ff3c7ca | 256 | static sbitmap reg_known_equiv_p; |
9ae8ffe7 | 257 | |
2a2c8203 JC |
258 | /* True when scanning insns from the start of the rtl to the |
259 | NOTE_INSN_FUNCTION_BEG note. */ | |
83bbd9b6 | 260 | static bool copying_arguments; |
9ae8ffe7 | 261 | |
1a5640b4 | 262 | |
3932261a | 263 | /* The splay-tree used to store the various alias set entries. */ |
9771b263 | 264 | static GTY (()) vec<alias_set_entry, va_gc> *alias_sets; |
ac3d9668 | 265 | \f |
55b34b5f RG |
266 | /* Build a decomposed reference object for querying the alias-oracle |
267 | from the MEM rtx and store it in *REF. | |
268 | Returns false if MEM is not suitable for the alias-oracle. */ | |
269 | ||
270 | static bool | |
271 | ao_ref_from_mem (ao_ref *ref, const_rtx mem) | |
272 | { | |
273 | tree expr = MEM_EXPR (mem); | |
274 | tree base; | |
275 | ||
276 | if (!expr) | |
277 | return false; | |
278 | ||
279 | ao_ref_init (ref, expr); | |
280 | ||
281 | /* Get the base of the reference and see if we have to reject or | |
282 | adjust it. */ | |
283 | base = ao_ref_base (ref); | |
284 | if (base == NULL_TREE) | |
285 | return false; | |
286 | ||
ef7a9fb8 RB |
287 | /* The tree oracle doesn't like bases that are neither decls |
288 | nor indirect references of SSA names. */ | |
289 | if (!(DECL_P (base) | |
290 | || (TREE_CODE (base) == MEM_REF | |
291 | && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME) | |
292 | || (TREE_CODE (base) == TARGET_MEM_REF | |
293 | && TREE_CODE (TMR_BASE (base)) == SSA_NAME))) | |
d15adbeb | 294 | return false; |
55b34b5f RG |
295 | |
296 | /* If this is a reference based on a partitioned decl replace the | |
ef7a9fb8 | 297 | base with a MEM_REF of the pointer representative we |
55b34b5f RG |
298 | created during stack slot partitioning. */ |
299 | if (TREE_CODE (base) == VAR_DECL | |
ef7a9fb8 | 300 | && ! is_global_var (base) |
55b34b5f RG |
301 | && cfun->gimple_df->decls_to_pointers != NULL) |
302 | { | |
303 | void *namep; | |
304 | namep = pointer_map_contains (cfun->gimple_df->decls_to_pointers, base); | |
305 | if (namep) | |
70f34814 | 306 | ref->base = build_simple_mem_ref (*(tree *)namep); |
d15adbeb | 307 | } |
55b34b5f RG |
308 | |
309 | ref->ref_alias_set = MEM_ALIAS_SET (mem); | |
310 | ||
f68396a1 RG |
311 | /* If MEM_OFFSET or MEM_SIZE are unknown what we got from MEM_EXPR |
312 | is conservative, so trust it. */ | |
527210c4 | 313 | if (!MEM_OFFSET_KNOWN_P (mem) |
f5541398 | 314 | || !MEM_SIZE_KNOWN_P (mem)) |
f68396a1 | 315 | return true; |
366f945f | 316 | |
b0e96404 RG |
317 | /* If the base decl is a parameter we can have negative MEM_OFFSET in |
318 | case of promoted subregs on bigendian targets. Trust the MEM_EXPR | |
319 | here. */ | |
527210c4 RS |
320 | if (MEM_OFFSET (mem) < 0 |
321 | && (MEM_SIZE (mem) + MEM_OFFSET (mem)) * BITS_PER_UNIT == ref->size) | |
b0e96404 RG |
322 | return true; |
323 | ||
f68396a1 RG |
324 | /* Otherwise continue and refine size and offset we got from analyzing |
325 | MEM_EXPR by using MEM_SIZE and MEM_OFFSET. */ | |
326 | ||
527210c4 | 327 | ref->offset += MEM_OFFSET (mem) * BITS_PER_UNIT; |
f5541398 | 328 | ref->size = MEM_SIZE (mem) * BITS_PER_UNIT; |
b0e96404 RG |
329 | |
330 | /* The MEM may extend into adjacent fields, so adjust max_size if | |
331 | necessary. */ | |
332 | if (ref->max_size != -1 | |
333 | && ref->size > ref->max_size) | |
334 | ref->max_size = ref->size; | |
335 | ||
336 | /* If MEM_OFFSET and MEM_SIZE get us outside of the base object of | |
337 | the MEM_EXPR punt. This happens for STRICT_ALIGNMENT targets a lot. */ | |
338 | if (MEM_EXPR (mem) != get_spill_slot_decl (false) | |
339 | && (ref->offset < 0 | |
340 | || (DECL_P (ref->base) | |
341 | && (!host_integerp (DECL_SIZE (ref->base), 1) | |
342 | || (TREE_INT_CST_LOW (DECL_SIZE ((ref->base))) | |
343 | < (unsigned HOST_WIDE_INT)(ref->offset + ref->size)))))) | |
344 | return false; | |
55b34b5f RG |
345 | |
346 | return true; | |
347 | } | |
348 | ||
349 | /* Query the alias-oracle on whether the two memory rtx X and MEM may | |
350 | alias. If TBAA_P is set also apply TBAA. Returns true if the | |
351 | two rtxen may alias, false otherwise. */ | |
352 | ||
353 | static bool | |
354 | rtx_refs_may_alias_p (const_rtx x, const_rtx mem, bool tbaa_p) | |
355 | { | |
356 | ao_ref ref1, ref2; | |
357 | ||
358 | if (!ao_ref_from_mem (&ref1, x) | |
359 | || !ao_ref_from_mem (&ref2, mem)) | |
360 | return true; | |
361 | ||
55e3bc4c RG |
362 | return refs_may_alias_p_1 (&ref1, &ref2, |
363 | tbaa_p | |
364 | && MEM_ALIAS_SET (x) != 0 | |
365 | && MEM_ALIAS_SET (mem) != 0); | |
55b34b5f RG |
366 | } |
367 | ||
3932261a MM |
368 | /* Returns a pointer to the alias set entry for ALIAS_SET, if there is |
369 | such an entry, or NULL otherwise. */ | |
370 | ||
9ddb66ca | 371 | static inline alias_set_entry |
4862826d | 372 | get_alias_set_entry (alias_set_type alias_set) |
3932261a | 373 | { |
9771b263 | 374 | return (*alias_sets)[alias_set]; |
3932261a MM |
375 | } |
376 | ||
ac3d9668 RK |
377 | /* Returns nonzero if the alias sets for MEM1 and MEM2 are such that |
378 | the two MEMs cannot alias each other. */ | |
3932261a | 379 | |
9ddb66ca | 380 | static inline int |
4f588890 | 381 | mems_in_disjoint_alias_sets_p (const_rtx mem1, const_rtx mem2) |
3932261a | 382 | { |
3932261a MM |
383 | /* Perform a basic sanity check. Namely, that there are no alias sets |
384 | if we're not using strict aliasing. This helps to catch bugs | |
385 | whereby someone uses PUT_CODE, but doesn't clear MEM_ALIAS_SET, or | |
386 | where a MEM is allocated in some way other than by the use of | |
387 | gen_rtx_MEM, and the MEM_ALIAS_SET is not cleared. If we begin to | |
388 | use alias sets to indicate that spilled registers cannot alias each | |
389 | other, we might need to remove this check. */ | |
298e6adc NS |
390 | gcc_assert (flag_strict_aliasing |
391 | || (!MEM_ALIAS_SET (mem1) && !MEM_ALIAS_SET (mem2))); | |
3932261a | 392 | |
1da68f56 RK |
393 | return ! alias_sets_conflict_p (MEM_ALIAS_SET (mem1), MEM_ALIAS_SET (mem2)); |
394 | } | |
3932261a | 395 | |
1da68f56 RK |
396 | /* Insert the NODE into the splay tree given by DATA. Used by |
397 | record_alias_subset via splay_tree_foreach. */ | |
398 | ||
399 | static int | |
4682ae04 | 400 | insert_subset_children (splay_tree_node node, void *data) |
1da68f56 RK |
401 | { |
402 | splay_tree_insert ((splay_tree) data, node->key, node->value); | |
403 | ||
404 | return 0; | |
405 | } | |
406 | ||
c58936b6 DB |
407 | /* Return true if the first alias set is a subset of the second. */ |
408 | ||
409 | bool | |
4862826d | 410 | alias_set_subset_of (alias_set_type set1, alias_set_type set2) |
c58936b6 DB |
411 | { |
412 | alias_set_entry ase; | |
413 | ||
414 | /* Everything is a subset of the "aliases everything" set. */ | |
415 | if (set2 == 0) | |
416 | return true; | |
417 | ||
418 | /* Otherwise, check if set1 is a subset of set2. */ | |
419 | ase = get_alias_set_entry (set2); | |
420 | if (ase != 0 | |
038a39d1 | 421 | && (ase->has_zero_child |
a7a512be RG |
422 | || splay_tree_lookup (ase->children, |
423 | (splay_tree_key) set1))) | |
c58936b6 DB |
424 | return true; |
425 | return false; | |
426 | } | |
427 | ||
1da68f56 RK |
428 | /* Return 1 if the two specified alias sets may conflict. */ |
429 | ||
430 | int | |
4862826d | 431 | alias_sets_conflict_p (alias_set_type set1, alias_set_type set2) |
1da68f56 RK |
432 | { |
433 | alias_set_entry ase; | |
434 | ||
836f7794 EB |
435 | /* The easy case. */ |
436 | if (alias_sets_must_conflict_p (set1, set2)) | |
1da68f56 | 437 | return 1; |
3932261a | 438 | |
3bdf5ad1 | 439 | /* See if the first alias set is a subset of the second. */ |
1da68f56 | 440 | ase = get_alias_set_entry (set1); |
2bf105ab RK |
441 | if (ase != 0 |
442 | && (ase->has_zero_child | |
443 | || splay_tree_lookup (ase->children, | |
1da68f56 RK |
444 | (splay_tree_key) set2))) |
445 | return 1; | |
3932261a MM |
446 | |
447 | /* Now do the same, but with the alias sets reversed. */ | |
1da68f56 | 448 | ase = get_alias_set_entry (set2); |
2bf105ab RK |
449 | if (ase != 0 |
450 | && (ase->has_zero_child | |
451 | || splay_tree_lookup (ase->children, | |
1da68f56 RK |
452 | (splay_tree_key) set1))) |
453 | return 1; | |
3932261a | 454 | |
1da68f56 | 455 | /* The two alias sets are distinct and neither one is the |
836f7794 | 456 | child of the other. Therefore, they cannot conflict. */ |
1da68f56 | 457 | return 0; |
3932261a | 458 | } |
5399d643 | 459 | |
836f7794 | 460 | /* Return 1 if the two specified alias sets will always conflict. */ |
5399d643 JW |
461 | |
462 | int | |
4862826d | 463 | alias_sets_must_conflict_p (alias_set_type set1, alias_set_type set2) |
5399d643 JW |
464 | { |
465 | if (set1 == 0 || set2 == 0 || set1 == set2) | |
466 | return 1; | |
467 | ||
468 | return 0; | |
469 | } | |
470 | ||
1da68f56 RK |
471 | /* Return 1 if any MEM object of type T1 will always conflict (using the |
472 | dependency routines in this file) with any MEM object of type T2. | |
473 | This is used when allocating temporary storage. If T1 and/or T2 are | |
474 | NULL_TREE, it means we know nothing about the storage. */ | |
475 | ||
476 | int | |
4682ae04 | 477 | objects_must_conflict_p (tree t1, tree t2) |
1da68f56 | 478 | { |
4862826d | 479 | alias_set_type set1, set2; |
82d610ec | 480 | |
e8ea2809 RK |
481 | /* If neither has a type specified, we don't know if they'll conflict |
482 | because we may be using them to store objects of various types, for | |
483 | example the argument and local variables areas of inlined functions. */ | |
981a4c34 | 484 | if (t1 == 0 && t2 == 0) |
e8ea2809 RK |
485 | return 0; |
486 | ||
1da68f56 RK |
487 | /* If they are the same type, they must conflict. */ |
488 | if (t1 == t2 | |
489 | /* Likewise if both are volatile. */ | |
490 | || (t1 != 0 && TYPE_VOLATILE (t1) && t2 != 0 && TYPE_VOLATILE (t2))) | |
491 | return 1; | |
492 | ||
82d610ec RK |
493 | set1 = t1 ? get_alias_set (t1) : 0; |
494 | set2 = t2 ? get_alias_set (t2) : 0; | |
1da68f56 | 495 | |
836f7794 EB |
496 | /* We can't use alias_sets_conflict_p because we must make sure |
497 | that every subtype of t1 will conflict with every subtype of | |
82d610ec RK |
498 | t2 for which a pair of subobjects of these respective subtypes |
499 | overlaps on the stack. */ | |
836f7794 | 500 | return alias_sets_must_conflict_p (set1, set2); |
1da68f56 RK |
501 | } |
502 | \f | |
b4ada065 RB |
503 | /* Return the outermost parent of component present in the chain of |
504 | component references handled by get_inner_reference in T with the | |
505 | following property: | |
506 | - the component is non-addressable, or | |
507 | - the parent has alias set zero, | |
508 | or NULL_TREE if no such parent exists. In the former cases, the alias | |
509 | set of this parent is the alias set that must be used for T itself. */ | |
510 | ||
511 | tree | |
512 | component_uses_parent_alias_set_from (const_tree t) | |
6e24b709 | 513 | { |
b4ada065 | 514 | const_tree found = NULL_TREE; |
afe84921 | 515 | |
b4ada065 RB |
516 | while (handled_component_p (t)) |
517 | { | |
afe84921 RH |
518 | switch (TREE_CODE (t)) |
519 | { | |
520 | case COMPONENT_REF: | |
521 | if (DECL_NONADDRESSABLE_P (TREE_OPERAND (t, 1))) | |
b4ada065 | 522 | found = t; |
afe84921 RH |
523 | break; |
524 | ||
525 | case ARRAY_REF: | |
526 | case ARRAY_RANGE_REF: | |
527 | if (TYPE_NONALIASED_COMPONENT (TREE_TYPE (TREE_OPERAND (t, 0)))) | |
b4ada065 | 528 | found = t; |
afe84921 RH |
529 | break; |
530 | ||
531 | case REALPART_EXPR: | |
532 | case IMAGPART_EXPR: | |
533 | break; | |
534 | ||
b4ada065 RB |
535 | case BIT_FIELD_REF: |
536 | case VIEW_CONVERT_EXPR: | |
afe84921 | 537 | /* Bitfields and casts are never addressable. */ |
b4ada065 RB |
538 | found = t; |
539 | break; | |
540 | ||
541 | default: | |
542 | gcc_unreachable (); | |
afe84921 RH |
543 | } |
544 | ||
b4ada065 RB |
545 | if (get_alias_set (TREE_TYPE (TREE_OPERAND (t, 0))) == 0) |
546 | found = t; | |
547 | ||
afe84921 RH |
548 | t = TREE_OPERAND (t, 0); |
549 | } | |
b4ada065 RB |
550 | |
551 | if (found) | |
552 | return TREE_OPERAND (found, 0); | |
553 | ||
554 | return NULL_TREE; | |
6e24b709 RK |
555 | } |
556 | ||
f40333af RB |
557 | |
558 | /* Return whether the pointer-type T effective for aliasing may | |
559 | access everything and thus the reference has to be assigned | |
560 | alias-set zero. */ | |
561 | ||
562 | static bool | |
563 | ref_all_alias_ptr_type_p (const_tree t) | |
564 | { | |
565 | return (TREE_CODE (TREE_TYPE (t)) == VOID_TYPE | |
566 | || TYPE_REF_CAN_ALIAS_ALL (t)); | |
567 | } | |
568 | ||
5006671f RG |
569 | /* Return the alias set for the memory pointed to by T, which may be |
570 | either a type or an expression. Return -1 if there is nothing | |
571 | special about dereferencing T. */ | |
572 | ||
573 | static alias_set_type | |
574 | get_deref_alias_set_1 (tree t) | |
575 | { | |
5b21f0f3 | 576 | /* All we care about is the type. */ |
5006671f | 577 | if (! TYPE_P (t)) |
5b21f0f3 | 578 | t = TREE_TYPE (t); |
5006671f RG |
579 | |
580 | /* If we have an INDIRECT_REF via a void pointer, we don't | |
581 | know anything about what that might alias. Likewise if the | |
582 | pointer is marked that way. */ | |
f40333af | 583 | if (ref_all_alias_ptr_type_p (t)) |
5006671f RG |
584 | return 0; |
585 | ||
586 | return -1; | |
587 | } | |
588 | ||
589 | /* Return the alias set for the memory pointed to by T, which may be | |
590 | either a type or an expression. */ | |
591 | ||
592 | alias_set_type | |
593 | get_deref_alias_set (tree t) | |
594 | { | |
f40333af RB |
595 | /* If we're not doing any alias analysis, just assume everything |
596 | aliases everything else. */ | |
597 | if (!flag_strict_aliasing) | |
598 | return 0; | |
599 | ||
5006671f RG |
600 | alias_set_type set = get_deref_alias_set_1 (t); |
601 | ||
602 | /* Fall back to the alias-set of the pointed-to type. */ | |
603 | if (set == -1) | |
604 | { | |
605 | if (! TYPE_P (t)) | |
606 | t = TREE_TYPE (t); | |
607 | set = get_alias_set (TREE_TYPE (t)); | |
608 | } | |
609 | ||
610 | return set; | |
611 | } | |
612 | ||
f40333af RB |
613 | /* Return the pointer-type relevant for TBAA purposes from the |
614 | memory reference tree *T or NULL_TREE in which case *T is | |
615 | adjusted to point to the outermost component reference that | |
616 | can be used for assigning an alias set. */ | |
617 | ||
618 | static tree | |
619 | reference_alias_ptr_type_1 (tree *t) | |
620 | { | |
621 | tree inner; | |
622 | ||
623 | /* Get the base object of the reference. */ | |
624 | inner = *t; | |
625 | while (handled_component_p (inner)) | |
626 | { | |
627 | /* If there is a VIEW_CONVERT_EXPR in the chain we cannot use | |
628 | the type of any component references that wrap it to | |
629 | determine the alias-set. */ | |
630 | if (TREE_CODE (inner) == VIEW_CONVERT_EXPR) | |
631 | *t = TREE_OPERAND (inner, 0); | |
632 | inner = TREE_OPERAND (inner, 0); | |
633 | } | |
634 | ||
635 | /* Handle pointer dereferences here, they can override the | |
636 | alias-set. */ | |
637 | if (INDIRECT_REF_P (inner) | |
638 | && ref_all_alias_ptr_type_p (TREE_TYPE (TREE_OPERAND (inner, 0)))) | |
639 | return TREE_TYPE (TREE_OPERAND (inner, 0)); | |
640 | else if (TREE_CODE (inner) == TARGET_MEM_REF) | |
641 | return TREE_TYPE (TMR_OFFSET (inner)); | |
642 | else if (TREE_CODE (inner) == MEM_REF | |
643 | && ref_all_alias_ptr_type_p (TREE_TYPE (TREE_OPERAND (inner, 1)))) | |
644 | return TREE_TYPE (TREE_OPERAND (inner, 1)); | |
645 | ||
646 | /* If the innermost reference is a MEM_REF that has a | |
647 | conversion embedded treat it like a VIEW_CONVERT_EXPR above, | |
648 | using the memory access type for determining the alias-set. */ | |
649 | if (TREE_CODE (inner) == MEM_REF | |
650 | && (TYPE_MAIN_VARIANT (TREE_TYPE (inner)) | |
651 | != TYPE_MAIN_VARIANT | |
652 | (TREE_TYPE (TREE_TYPE (TREE_OPERAND (inner, 1)))))) | |
653 | return TREE_TYPE (TREE_OPERAND (inner, 1)); | |
654 | ||
b4ada065 RB |
655 | /* Otherwise, pick up the outermost object that we could have |
656 | a pointer to. */ | |
657 | tree tem = component_uses_parent_alias_set_from (*t); | |
658 | if (tem) | |
659 | *t = tem; | |
f40333af RB |
660 | |
661 | return NULL_TREE; | |
662 | } | |
663 | ||
664 | /* Return the pointer-type relevant for TBAA purposes from the | |
665 | gimple memory reference tree T. This is the type to be used for | |
666 | the offset operand of MEM_REF or TARGET_MEM_REF replacements of T | |
667 | and guarantees that get_alias_set will return the same alias | |
668 | set for T and the replacement. */ | |
669 | ||
670 | tree | |
671 | reference_alias_ptr_type (tree t) | |
672 | { | |
673 | tree ptype = reference_alias_ptr_type_1 (&t); | |
674 | /* If there is a given pointer type for aliasing purposes, return it. */ | |
675 | if (ptype != NULL_TREE) | |
676 | return ptype; | |
677 | ||
678 | /* Otherwise build one from the outermost component reference we | |
679 | may use. */ | |
680 | if (TREE_CODE (t) == MEM_REF | |
681 | || TREE_CODE (t) == TARGET_MEM_REF) | |
682 | return TREE_TYPE (TREE_OPERAND (t, 1)); | |
683 | else | |
684 | return build_pointer_type (TYPE_MAIN_VARIANT (TREE_TYPE (t))); | |
685 | } | |
686 | ||
687 | /* Return whether the pointer-types T1 and T2 used to determine | |
688 | two alias sets of two references will yield the same answer | |
689 | from get_deref_alias_set. */ | |
690 | ||
691 | bool | |
692 | alias_ptr_types_compatible_p (tree t1, tree t2) | |
693 | { | |
694 | if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2)) | |
695 | return true; | |
696 | ||
697 | if (ref_all_alias_ptr_type_p (t1) | |
698 | || ref_all_alias_ptr_type_p (t2)) | |
699 | return false; | |
700 | ||
701 | return (TYPE_MAIN_VARIANT (TREE_TYPE (t1)) | |
702 | == TYPE_MAIN_VARIANT (TREE_TYPE (t2))); | |
703 | } | |
704 | ||
3bdf5ad1 RK |
705 | /* Return the alias set for T, which may be either a type or an |
706 | expression. Call language-specific routine for help, if needed. */ | |
707 | ||
4862826d | 708 | alias_set_type |
4682ae04 | 709 | get_alias_set (tree t) |
3bdf5ad1 | 710 | { |
4862826d | 711 | alias_set_type set; |
3bdf5ad1 RK |
712 | |
713 | /* If we're not doing any alias analysis, just assume everything | |
714 | aliases everything else. Also return 0 if this or its type is | |
715 | an error. */ | |
716 | if (! flag_strict_aliasing || t == error_mark_node | |
717 | || (! TYPE_P (t) | |
718 | && (TREE_TYPE (t) == 0 || TREE_TYPE (t) == error_mark_node))) | |
719 | return 0; | |
720 | ||
721 | /* We can be passed either an expression or a type. This and the | |
f47e9b4e RK |
722 | language-specific routine may make mutually-recursive calls to each other |
723 | to figure out what to do. At each juncture, we see if this is a tree | |
724 | that the language may need to handle specially. First handle things that | |
738cc472 | 725 | aren't types. */ |
f824e5c3 | 726 | if (! TYPE_P (t)) |
3bdf5ad1 | 727 | { |
70f34814 RG |
728 | /* Give the language a chance to do something with this tree |
729 | before we look at it. */ | |
8ac61af7 | 730 | STRIP_NOPS (t); |
ae2bcd98 | 731 | set = lang_hooks.get_alias_set (t); |
8ac61af7 RK |
732 | if (set != -1) |
733 | return set; | |
734 | ||
f40333af RB |
735 | /* Get the alias pointer-type to use or the outermost object |
736 | that we could have a pointer to. */ | |
737 | tree ptype = reference_alias_ptr_type_1 (&t); | |
738 | if (ptype != NULL) | |
739 | return get_deref_alias_set (ptype); | |
f824e5c3 | 740 | |
738cc472 RK |
741 | /* If we've already determined the alias set for a decl, just return |
742 | it. This is necessary for C++ anonymous unions, whose component | |
743 | variables don't look like union members (boo!). */ | |
5755cd38 | 744 | if (TREE_CODE (t) == VAR_DECL |
3c0cb5de | 745 | && DECL_RTL_SET_P (t) && MEM_P (DECL_RTL (t))) |
5755cd38 JM |
746 | return MEM_ALIAS_SET (DECL_RTL (t)); |
747 | ||
f824e5c3 RK |
748 | /* Now all we care about is the type. */ |
749 | t = TREE_TYPE (t); | |
3bdf5ad1 RK |
750 | } |
751 | ||
3bdf5ad1 | 752 | /* Variant qualifiers don't affect the alias set, so get the main |
daad0278 | 753 | variant. */ |
3bdf5ad1 | 754 | t = TYPE_MAIN_VARIANT (t); |
daad0278 RG |
755 | |
756 | /* Always use the canonical type as well. If this is a type that | |
757 | requires structural comparisons to identify compatible types | |
758 | use alias set zero. */ | |
759 | if (TYPE_STRUCTURAL_EQUALITY_P (t)) | |
cb9c2485 JM |
760 | { |
761 | /* Allow the language to specify another alias set for this | |
762 | type. */ | |
763 | set = lang_hooks.get_alias_set (t); | |
764 | if (set != -1) | |
765 | return set; | |
766 | return 0; | |
767 | } | |
7be7d292 | 768 | |
daad0278 | 769 | t = TYPE_CANONICAL (t); |
7be7d292 | 770 | |
96d91dcf RG |
771 | /* The canonical type should not require structural equality checks. */ |
772 | gcc_checking_assert (!TYPE_STRUCTURAL_EQUALITY_P (t)); | |
daad0278 RG |
773 | |
774 | /* If this is a type with a known alias set, return it. */ | |
738cc472 | 775 | if (TYPE_ALIAS_SET_KNOWN_P (t)) |
3bdf5ad1 RK |
776 | return TYPE_ALIAS_SET (t); |
777 | ||
36784d0e RG |
778 | /* We don't want to set TYPE_ALIAS_SET for incomplete types. */ |
779 | if (!COMPLETE_TYPE_P (t)) | |
780 | { | |
781 | /* For arrays with unknown size the conservative answer is the | |
782 | alias set of the element type. */ | |
783 | if (TREE_CODE (t) == ARRAY_TYPE) | |
784 | return get_alias_set (TREE_TYPE (t)); | |
785 | ||
786 | /* But return zero as a conservative answer for incomplete types. */ | |
787 | return 0; | |
788 | } | |
789 | ||
3bdf5ad1 | 790 | /* See if the language has special handling for this type. */ |
ae2bcd98 | 791 | set = lang_hooks.get_alias_set (t); |
8ac61af7 | 792 | if (set != -1) |
738cc472 | 793 | return set; |
2bf105ab | 794 | |
3bdf5ad1 RK |
795 | /* There are no objects of FUNCTION_TYPE, so there's no point in |
796 | using up an alias set for them. (There are, of course, pointers | |
797 | and references to functions, but that's different.) */ | |
7be7d292 | 798 | else if (TREE_CODE (t) == FUNCTION_TYPE || TREE_CODE (t) == METHOD_TYPE) |
3bdf5ad1 | 799 | set = 0; |
74d86f4f RH |
800 | |
801 | /* Unless the language specifies otherwise, let vector types alias | |
802 | their components. This avoids some nasty type punning issues in | |
803 | normal usage. And indeed lets vectors be treated more like an | |
804 | array slice. */ | |
805 | else if (TREE_CODE (t) == VECTOR_TYPE) | |
806 | set = get_alias_set (TREE_TYPE (t)); | |
807 | ||
4653cae5 RG |
808 | /* Unless the language specifies otherwise, treat array types the |
809 | same as their components. This avoids the asymmetry we get | |
810 | through recording the components. Consider accessing a | |
811 | character(kind=1) through a reference to a character(kind=1)[1:1]. | |
812 | Or consider if we want to assign integer(kind=4)[0:D.1387] and | |
813 | integer(kind=4)[4] the same alias set or not. | |
814 | Just be pragmatic here and make sure the array and its element | |
815 | type get the same alias set assigned. */ | |
7be7d292 | 816 | else if (TREE_CODE (t) == ARRAY_TYPE && !TYPE_NONALIASED_COMPONENT (t)) |
4653cae5 RG |
817 | set = get_alias_set (TREE_TYPE (t)); |
818 | ||
0ceb0201 RG |
819 | /* From the former common C and C++ langhook implementation: |
820 | ||
821 | Unfortunately, there is no canonical form of a pointer type. | |
822 | In particular, if we have `typedef int I', then `int *', and | |
823 | `I *' are different types. So, we have to pick a canonical | |
824 | representative. We do this below. | |
825 | ||
826 | Technically, this approach is actually more conservative that | |
827 | it needs to be. In particular, `const int *' and `int *' | |
828 | should be in different alias sets, according to the C and C++ | |
829 | standard, since their types are not the same, and so, | |
830 | technically, an `int **' and `const int **' cannot point at | |
831 | the same thing. | |
832 | ||
833 | But, the standard is wrong. In particular, this code is | |
834 | legal C++: | |
835 | ||
836 | int *ip; | |
837 | int **ipp = &ip; | |
838 | const int* const* cipp = ipp; | |
839 | And, it doesn't make sense for that to be legal unless you | |
840 | can dereference IPP and CIPP. So, we ignore cv-qualifiers on | |
841 | the pointed-to types. This issue has been reported to the | |
842 | C++ committee. | |
843 | ||
844 | In addition to the above canonicalization issue, with LTO | |
845 | we should also canonicalize `T (*)[]' to `T *' avoiding | |
846 | alias issues with pointer-to element types and pointer-to | |
847 | array types. | |
848 | ||
849 | Likewise we need to deal with the situation of incomplete | |
850 | pointed-to types and make `*(struct X **)&a' and | |
851 | `*(struct X {} **)&a' alias. Otherwise we will have to | |
852 | guarantee that all pointer-to incomplete type variants | |
853 | will be replaced by pointer-to complete type variants if | |
854 | they are available. | |
855 | ||
856 | With LTO the convenient situation of using `void *' to | |
857 | access and store any pointer type will also become | |
858 | more apparent (and `void *' is just another pointer-to | |
859 | incomplete type). Assigning alias-set zero to `void *' | |
860 | and all pointer-to incomplete types is a not appealing | |
861 | solution. Assigning an effective alias-set zero only | |
862 | affecting pointers might be - by recording proper subset | |
863 | relationships of all pointer alias-sets. | |
864 | ||
865 | Pointer-to function types are another grey area which | |
866 | needs caution. Globbing them all into one alias-set | |
867 | or the above effective zero set would work. | |
868 | ||
869 | For now just assign the same alias-set to all pointers. | |
870 | That's simple and avoids all the above problems. */ | |
871 | else if (POINTER_TYPE_P (t) | |
872 | && t != ptr_type_node) | |
96d91dcf | 873 | set = get_alias_set (ptr_type_node); |
0ceb0201 | 874 | |
7be7d292 | 875 | /* Otherwise make a new alias set for this type. */ |
3bdf5ad1 | 876 | else |
96d91dcf RG |
877 | { |
878 | /* Each canonical type gets its own alias set, so canonical types | |
879 | shouldn't form a tree. It doesn't really matter for types | |
880 | we handle specially above, so only check it where it possibly | |
881 | would result in a bogus alias set. */ | |
882 | gcc_checking_assert (TYPE_CANONICAL (t) == t); | |
883 | ||
884 | set = new_alias_set (); | |
885 | } | |
3bdf5ad1 RK |
886 | |
887 | TYPE_ALIAS_SET (t) = set; | |
2bf105ab | 888 | |
7be7d292 EB |
889 | /* If this is an aggregate type or a complex type, we must record any |
890 | component aliasing information. */ | |
1d79fd2c | 891 | if (AGGREGATE_TYPE_P (t) || TREE_CODE (t) == COMPLEX_TYPE) |
2bf105ab RK |
892 | record_component_aliases (t); |
893 | ||
3bdf5ad1 RK |
894 | return set; |
895 | } | |
896 | ||
897 | /* Return a brand-new alias set. */ | |
898 | ||
4862826d | 899 | alias_set_type |
4682ae04 | 900 | new_alias_set (void) |
3bdf5ad1 | 901 | { |
3bdf5ad1 | 902 | if (flag_strict_aliasing) |
9ddb66ca | 903 | { |
1a5640b4 | 904 | if (alias_sets == 0) |
9771b263 DN |
905 | vec_safe_push (alias_sets, (alias_set_entry) 0); |
906 | vec_safe_push (alias_sets, (alias_set_entry) 0); | |
907 | return alias_sets->length () - 1; | |
9ddb66ca | 908 | } |
3bdf5ad1 RK |
909 | else |
910 | return 0; | |
911 | } | |
3932261a | 912 | |
01d28c3f JM |
913 | /* Indicate that things in SUBSET can alias things in SUPERSET, but that |
914 | not everything that aliases SUPERSET also aliases SUBSET. For example, | |
915 | in C, a store to an `int' can alias a load of a structure containing an | |
916 | `int', and vice versa. But it can't alias a load of a 'double' member | |
917 | of the same structure. Here, the structure would be the SUPERSET and | |
918 | `int' the SUBSET. This relationship is also described in the comment at | |
919 | the beginning of this file. | |
920 | ||
921 | This function should be called only once per SUPERSET/SUBSET pair. | |
3932261a MM |
922 | |
923 | It is illegal for SUPERSET to be zero; everything is implicitly a | |
924 | subset of alias set zero. */ | |
925 | ||
794511d2 | 926 | void |
4862826d | 927 | record_alias_subset (alias_set_type superset, alias_set_type subset) |
3932261a MM |
928 | { |
929 | alias_set_entry superset_entry; | |
930 | alias_set_entry subset_entry; | |
931 | ||
f47e9b4e RK |
932 | /* It is possible in complex type situations for both sets to be the same, |
933 | in which case we can ignore this operation. */ | |
934 | if (superset == subset) | |
935 | return; | |
936 | ||
298e6adc | 937 | gcc_assert (superset); |
3932261a MM |
938 | |
939 | superset_entry = get_alias_set_entry (superset); | |
ca7fd9cd | 940 | if (superset_entry == 0) |
3932261a MM |
941 | { |
942 | /* Create an entry for the SUPERSET, so that we have a place to | |
943 | attach the SUBSET. */ | |
a9429e29 | 944 | superset_entry = ggc_alloc_cleared_alias_set_entry_d (); |
3932261a | 945 | superset_entry->alias_set = superset; |
ca7fd9cd | 946 | superset_entry->children |
a9429e29 LB |
947 | = splay_tree_new_ggc (splay_tree_compare_ints, |
948 | ggc_alloc_splay_tree_scalar_scalar_splay_tree_s, | |
949 | ggc_alloc_splay_tree_scalar_scalar_splay_tree_node_s); | |
570eb5c8 | 950 | superset_entry->has_zero_child = 0; |
9771b263 | 951 | (*alias_sets)[superset] = superset_entry; |
3932261a MM |
952 | } |
953 | ||
2bf105ab RK |
954 | if (subset == 0) |
955 | superset_entry->has_zero_child = 1; | |
956 | else | |
957 | { | |
958 | subset_entry = get_alias_set_entry (subset); | |
959 | /* If there is an entry for the subset, enter all of its children | |
960 | (if they are not already present) as children of the SUPERSET. */ | |
ca7fd9cd | 961 | if (subset_entry) |
2bf105ab RK |
962 | { |
963 | if (subset_entry->has_zero_child) | |
964 | superset_entry->has_zero_child = 1; | |
d4b60170 | 965 | |
2bf105ab RK |
966 | splay_tree_foreach (subset_entry->children, insert_subset_children, |
967 | superset_entry->children); | |
968 | } | |
3932261a | 969 | |
2bf105ab | 970 | /* Enter the SUBSET itself as a child of the SUPERSET. */ |
ca7fd9cd | 971 | splay_tree_insert (superset_entry->children, |
2bf105ab RK |
972 | (splay_tree_key) subset, 0); |
973 | } | |
3932261a MM |
974 | } |
975 | ||
a0c33338 RK |
976 | /* Record that component types of TYPE, if any, are part of that type for |
977 | aliasing purposes. For record types, we only record component types | |
b5487346 EB |
978 | for fields that are not marked non-addressable. For array types, we |
979 | only record the component type if it is not marked non-aliased. */ | |
a0c33338 RK |
980 | |
981 | void | |
4682ae04 | 982 | record_component_aliases (tree type) |
a0c33338 | 983 | { |
4862826d | 984 | alias_set_type superset = get_alias_set (type); |
a0c33338 RK |
985 | tree field; |
986 | ||
987 | if (superset == 0) | |
988 | return; | |
989 | ||
990 | switch (TREE_CODE (type)) | |
991 | { | |
a0c33338 RK |
992 | case RECORD_TYPE: |
993 | case UNION_TYPE: | |
994 | case QUAL_UNION_TYPE: | |
6614fd40 | 995 | /* Recursively record aliases for the base classes, if there are any. */ |
fa743e8c | 996 | if (TYPE_BINFO (type)) |
ca7fd9cd KH |
997 | { |
998 | int i; | |
fa743e8c | 999 | tree binfo, base_binfo; |
c22cacf3 | 1000 | |
fa743e8c NS |
1001 | for (binfo = TYPE_BINFO (type), i = 0; |
1002 | BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) | |
1003 | record_alias_subset (superset, | |
1004 | get_alias_set (BINFO_TYPE (base_binfo))); | |
ca7fd9cd | 1005 | } |
910ad8de | 1006 | for (field = TYPE_FIELDS (type); field != 0; field = DECL_CHAIN (field)) |
b5487346 | 1007 | if (TREE_CODE (field) == FIELD_DECL && !DECL_NONADDRESSABLE_P (field)) |
2bf105ab | 1008 | record_alias_subset (superset, get_alias_set (TREE_TYPE (field))); |
a0c33338 RK |
1009 | break; |
1010 | ||
1d79fd2c JW |
1011 | case COMPLEX_TYPE: |
1012 | record_alias_subset (superset, get_alias_set (TREE_TYPE (type))); | |
1013 | break; | |
1014 | ||
4653cae5 RG |
1015 | /* VECTOR_TYPE and ARRAY_TYPE share the alias set with their |
1016 | element type. */ | |
1017 | ||
a0c33338 RK |
1018 | default: |
1019 | break; | |
1020 | } | |
1021 | } | |
1022 | ||
3bdf5ad1 RK |
1023 | /* Allocate an alias set for use in storing and reading from the varargs |
1024 | spill area. */ | |
1025 | ||
4862826d | 1026 | static GTY(()) alias_set_type varargs_set = -1; |
f103e34d | 1027 | |
4862826d | 1028 | alias_set_type |
4682ae04 | 1029 | get_varargs_alias_set (void) |
3bdf5ad1 | 1030 | { |
cd3ce9b4 JM |
1031 | #if 1 |
1032 | /* We now lower VA_ARG_EXPR, and there's currently no way to attach the | |
1033 | varargs alias set to an INDIRECT_REF (FIXME!), so we can't | |
1034 | consistently use the varargs alias set for loads from the varargs | |
1035 | area. So don't use it anywhere. */ | |
1036 | return 0; | |
1037 | #else | |
f103e34d GK |
1038 | if (varargs_set == -1) |
1039 | varargs_set = new_alias_set (); | |
3bdf5ad1 | 1040 | |
f103e34d | 1041 | return varargs_set; |
cd3ce9b4 | 1042 | #endif |
3bdf5ad1 RK |
1043 | } |
1044 | ||
1045 | /* Likewise, but used for the fixed portions of the frame, e.g., register | |
1046 | save areas. */ | |
1047 | ||
4862826d | 1048 | static GTY(()) alias_set_type frame_set = -1; |
f103e34d | 1049 | |
4862826d | 1050 | alias_set_type |
4682ae04 | 1051 | get_frame_alias_set (void) |
3bdf5ad1 | 1052 | { |
f103e34d GK |
1053 | if (frame_set == -1) |
1054 | frame_set = new_alias_set (); | |
3bdf5ad1 | 1055 | |
f103e34d | 1056 | return frame_set; |
3bdf5ad1 RK |
1057 | } |
1058 | ||
9fc37b2b RS |
1059 | /* Create a new, unique base with id ID. */ |
1060 | ||
1061 | static rtx | |
1062 | unique_base_value (HOST_WIDE_INT id) | |
1063 | { | |
1064 | return gen_rtx_ADDRESS (Pmode, id); | |
1065 | } | |
1066 | ||
1067 | /* Return true if accesses based on any other base value cannot alias | |
1068 | those based on X. */ | |
1069 | ||
1070 | static bool | |
1071 | unique_base_value_p (rtx x) | |
1072 | { | |
1073 | return GET_CODE (x) == ADDRESS && GET_MODE (x) == Pmode; | |
1074 | } | |
1075 | ||
1076 | /* Return true if X is known to be a base value. */ | |
1077 | ||
1078 | static bool | |
1079 | known_base_value_p (rtx x) | |
1080 | { | |
1081 | switch (GET_CODE (x)) | |
1082 | { | |
1083 | case LABEL_REF: | |
1084 | case SYMBOL_REF: | |
1085 | return true; | |
1086 | ||
1087 | case ADDRESS: | |
1088 | /* Arguments may or may not be bases; we don't know for sure. */ | |
1089 | return GET_MODE (x) != VOIDmode; | |
1090 | ||
1091 | default: | |
1092 | return false; | |
1093 | } | |
1094 | } | |
1095 | ||
2a2c8203 JC |
1096 | /* Inside SRC, the source of a SET, find a base address. */ |
1097 | ||
9ae8ffe7 | 1098 | static rtx |
4682ae04 | 1099 | find_base_value (rtx src) |
9ae8ffe7 | 1100 | { |
713f41f9 | 1101 | unsigned int regno; |
0aacc8ed | 1102 | |
53451050 RS |
1103 | #if defined (FIND_BASE_TERM) |
1104 | /* Try machine-dependent ways to find the base term. */ | |
1105 | src = FIND_BASE_TERM (src); | |
1106 | #endif | |
1107 | ||
9ae8ffe7 JL |
1108 | switch (GET_CODE (src)) |
1109 | { | |
1110 | case SYMBOL_REF: | |
1111 | case LABEL_REF: | |
1112 | return src; | |
1113 | ||
1114 | case REG: | |
fb6754f0 | 1115 | regno = REGNO (src); |
d4b60170 | 1116 | /* At the start of a function, argument registers have known base |
2a2c8203 JC |
1117 | values which may be lost later. Returning an ADDRESS |
1118 | expression here allows optimization based on argument values | |
1119 | even when the argument registers are used for other purposes. */ | |
713f41f9 BS |
1120 | if (regno < FIRST_PSEUDO_REGISTER && copying_arguments) |
1121 | return new_reg_base_value[regno]; | |
73774bc7 | 1122 | |
eaf407a5 | 1123 | /* If a pseudo has a known base value, return it. Do not do this |
9b462c42 RH |
1124 | for non-fixed hard regs since it can result in a circular |
1125 | dependency chain for registers which have values at function entry. | |
eaf407a5 JL |
1126 | |
1127 | The test above is not sufficient because the scheduler may move | |
1128 | a copy out of an arg reg past the NOTE_INSN_FUNCTION_BEGIN. */ | |
9b462c42 | 1129 | if ((regno >= FIRST_PSEUDO_REGISTER || fixed_regs[regno]) |
9771b263 | 1130 | && regno < vec_safe_length (reg_base_value)) |
83bbd9b6 RH |
1131 | { |
1132 | /* If we're inside init_alias_analysis, use new_reg_base_value | |
1133 | to reduce the number of relaxation iterations. */ | |
1afdf91c | 1134 | if (new_reg_base_value && new_reg_base_value[regno] |
6fb5fa3c | 1135 | && DF_REG_DEF_COUNT (regno) == 1) |
83bbd9b6 RH |
1136 | return new_reg_base_value[regno]; |
1137 | ||
9771b263 DN |
1138 | if ((*reg_base_value)[regno]) |
1139 | return (*reg_base_value)[regno]; | |
83bbd9b6 | 1140 | } |
73774bc7 | 1141 | |
e3f049a8 | 1142 | return 0; |
9ae8ffe7 JL |
1143 | |
1144 | case MEM: | |
1145 | /* Check for an argument passed in memory. Only record in the | |
1146 | copying-arguments block; it is too hard to track changes | |
1147 | otherwise. */ | |
1148 | if (copying_arguments | |
1149 | && (XEXP (src, 0) == arg_pointer_rtx | |
1150 | || (GET_CODE (XEXP (src, 0)) == PLUS | |
1151 | && XEXP (XEXP (src, 0), 0) == arg_pointer_rtx))) | |
9fc37b2b | 1152 | return arg_base_value; |
9ae8ffe7 JL |
1153 | return 0; |
1154 | ||
1155 | case CONST: | |
1156 | src = XEXP (src, 0); | |
1157 | if (GET_CODE (src) != PLUS && GET_CODE (src) != MINUS) | |
1158 | break; | |
d4b60170 | 1159 | |
ec5c56db | 1160 | /* ... fall through ... */ |
2a2c8203 | 1161 | |
9ae8ffe7 JL |
1162 | case PLUS: |
1163 | case MINUS: | |
2a2c8203 | 1164 | { |
ec907dd8 JL |
1165 | rtx temp, src_0 = XEXP (src, 0), src_1 = XEXP (src, 1); |
1166 | ||
0134bf2d DE |
1167 | /* If either operand is a REG that is a known pointer, then it |
1168 | is the base. */ | |
1169 | if (REG_P (src_0) && REG_POINTER (src_0)) | |
1170 | return find_base_value (src_0); | |
1171 | if (REG_P (src_1) && REG_POINTER (src_1)) | |
1172 | return find_base_value (src_1); | |
1173 | ||
ec907dd8 JL |
1174 | /* If either operand is a REG, then see if we already have |
1175 | a known value for it. */ | |
0134bf2d | 1176 | if (REG_P (src_0)) |
ec907dd8 JL |
1177 | { |
1178 | temp = find_base_value (src_0); | |
d4b60170 | 1179 | if (temp != 0) |
ec907dd8 JL |
1180 | src_0 = temp; |
1181 | } | |
1182 | ||
0134bf2d | 1183 | if (REG_P (src_1)) |
ec907dd8 JL |
1184 | { |
1185 | temp = find_base_value (src_1); | |
d4b60170 | 1186 | if (temp!= 0) |
ec907dd8 JL |
1187 | src_1 = temp; |
1188 | } | |
2a2c8203 | 1189 | |
0134bf2d DE |
1190 | /* If either base is named object or a special address |
1191 | (like an argument or stack reference), then use it for the | |
1192 | base term. */ | |
9fc37b2b | 1193 | if (src_0 != 0 && known_base_value_p (src_0)) |
0134bf2d DE |
1194 | return src_0; |
1195 | ||
9fc37b2b | 1196 | if (src_1 != 0 && known_base_value_p (src_1)) |
0134bf2d DE |
1197 | return src_1; |
1198 | ||
d4b60170 | 1199 | /* Guess which operand is the base address: |
ec907dd8 JL |
1200 | If either operand is a symbol, then it is the base. If |
1201 | either operand is a CONST_INT, then the other is the base. */ | |
481683e1 | 1202 | if (CONST_INT_P (src_1) || CONSTANT_P (src_0)) |
2a2c8203 | 1203 | return find_base_value (src_0); |
481683e1 | 1204 | else if (CONST_INT_P (src_0) || CONSTANT_P (src_1)) |
ec907dd8 JL |
1205 | return find_base_value (src_1); |
1206 | ||
9ae8ffe7 | 1207 | return 0; |
2a2c8203 JC |
1208 | } |
1209 | ||
1210 | case LO_SUM: | |
1211 | /* The standard form is (lo_sum reg sym) so look only at the | |
1212 | second operand. */ | |
1213 | return find_base_value (XEXP (src, 1)); | |
9ae8ffe7 JL |
1214 | |
1215 | case AND: | |
1216 | /* If the second operand is constant set the base | |
ec5c56db | 1217 | address to the first operand. */ |
481683e1 | 1218 | if (CONST_INT_P (XEXP (src, 1)) && INTVAL (XEXP (src, 1)) != 0) |
2a2c8203 | 1219 | return find_base_value (XEXP (src, 0)); |
9ae8ffe7 JL |
1220 | return 0; |
1221 | ||
61f0131c | 1222 | case TRUNCATE: |
5932a4d4 | 1223 | /* As we do not know which address space the pointer is referring to, we can |
d4ebfa65 BE |
1224 | handle this only if the target does not support different pointer or |
1225 | address modes depending on the address space. */ | |
1226 | if (!target_default_pointer_address_modes_p ()) | |
1227 | break; | |
61f0131c R |
1228 | if (GET_MODE_SIZE (GET_MODE (src)) < GET_MODE_SIZE (Pmode)) |
1229 | break; | |
1230 | /* Fall through. */ | |
9ae8ffe7 | 1231 | case HIGH: |
d288e53d DE |
1232 | case PRE_INC: |
1233 | case PRE_DEC: | |
1234 | case POST_INC: | |
1235 | case POST_DEC: | |
1236 | case PRE_MODIFY: | |
1237 | case POST_MODIFY: | |
2a2c8203 | 1238 | return find_base_value (XEXP (src, 0)); |
1d300e19 | 1239 | |
0aacc8ed RK |
1240 | case ZERO_EXTEND: |
1241 | case SIGN_EXTEND: /* used for NT/Alpha pointers */ | |
5932a4d4 | 1242 | /* As we do not know which address space the pointer is referring to, we can |
d4ebfa65 BE |
1243 | handle this only if the target does not support different pointer or |
1244 | address modes depending on the address space. */ | |
1245 | if (!target_default_pointer_address_modes_p ()) | |
1246 | break; | |
1247 | ||
0aacc8ed RK |
1248 | { |
1249 | rtx temp = find_base_value (XEXP (src, 0)); | |
1250 | ||
5ae6cd0d | 1251 | if (temp != 0 && CONSTANT_P (temp)) |
0aacc8ed | 1252 | temp = convert_memory_address (Pmode, temp); |
0aacc8ed RK |
1253 | |
1254 | return temp; | |
1255 | } | |
1256 | ||
1d300e19 KG |
1257 | default: |
1258 | break; | |
9ae8ffe7 JL |
1259 | } |
1260 | ||
1261 | return 0; | |
1262 | } | |
1263 | ||
9fc37b2b RS |
1264 | /* Called from init_alias_analysis indirectly through note_stores, |
1265 | or directly if DEST is a register with a REG_NOALIAS note attached. | |
1266 | SET is null in the latter case. */ | |
9ae8ffe7 | 1267 | |
d4b60170 | 1268 | /* While scanning insns to find base values, reg_seen[N] is nonzero if |
9ae8ffe7 | 1269 | register N has been set in this function. */ |
d630245f | 1270 | static sbitmap reg_seen; |
9ae8ffe7 | 1271 | |
2a2c8203 | 1272 | static void |
7bc980e1 | 1273 | record_set (rtx dest, const_rtx set, void *data ATTRIBUTE_UNUSED) |
9ae8ffe7 | 1274 | { |
b3694847 | 1275 | unsigned regno; |
9ae8ffe7 | 1276 | rtx src; |
c28b4e40 | 1277 | int n; |
9ae8ffe7 | 1278 | |
f8cfc6aa | 1279 | if (!REG_P (dest)) |
9ae8ffe7 JL |
1280 | return; |
1281 | ||
fb6754f0 | 1282 | regno = REGNO (dest); |
9ae8ffe7 | 1283 | |
9771b263 | 1284 | gcc_checking_assert (regno < reg_base_value->length ()); |
ac606739 | 1285 | |
c28b4e40 JW |
1286 | /* If this spans multiple hard registers, then we must indicate that every |
1287 | register has an unusable value. */ | |
1288 | if (regno < FIRST_PSEUDO_REGISTER) | |
66fd46b6 | 1289 | n = hard_regno_nregs[regno][GET_MODE (dest)]; |
c28b4e40 JW |
1290 | else |
1291 | n = 1; | |
1292 | if (n != 1) | |
1293 | { | |
1294 | while (--n >= 0) | |
1295 | { | |
d7c028c0 | 1296 | bitmap_set_bit (reg_seen, regno + n); |
c28b4e40 JW |
1297 | new_reg_base_value[regno + n] = 0; |
1298 | } | |
1299 | return; | |
1300 | } | |
1301 | ||
9ae8ffe7 JL |
1302 | if (set) |
1303 | { | |
1304 | /* A CLOBBER wipes out any old value but does not prevent a previously | |
1305 | unset register from acquiring a base address (i.e. reg_seen is not | |
1306 | set). */ | |
1307 | if (GET_CODE (set) == CLOBBER) | |
1308 | { | |
ec907dd8 | 1309 | new_reg_base_value[regno] = 0; |
9ae8ffe7 JL |
1310 | return; |
1311 | } | |
1312 | src = SET_SRC (set); | |
1313 | } | |
1314 | else | |
1315 | { | |
9fc37b2b | 1316 | /* There's a REG_NOALIAS note against DEST. */ |
d7c028c0 | 1317 | if (bitmap_bit_p (reg_seen, regno)) |
9ae8ffe7 | 1318 | { |
ec907dd8 | 1319 | new_reg_base_value[regno] = 0; |
9ae8ffe7 JL |
1320 | return; |
1321 | } | |
d7c028c0 | 1322 | bitmap_set_bit (reg_seen, regno); |
9fc37b2b | 1323 | new_reg_base_value[regno] = unique_base_value (unique_id++); |
9ae8ffe7 JL |
1324 | return; |
1325 | } | |
1326 | ||
5da6f168 RS |
1327 | /* If this is not the first set of REGNO, see whether the new value |
1328 | is related to the old one. There are two cases of interest: | |
1329 | ||
1330 | (1) The register might be assigned an entirely new value | |
1331 | that has the same base term as the original set. | |
1332 | ||
1333 | (2) The set might be a simple self-modification that | |
1334 | cannot change REGNO's base value. | |
1335 | ||
1336 | If neither case holds, reject the original base value as invalid. | |
1337 | Note that the following situation is not detected: | |
1338 | ||
c22cacf3 | 1339 | extern int x, y; int *p = &x; p += (&y-&x); |
5da6f168 | 1340 | |
9ae8ffe7 JL |
1341 | ANSI C does not allow computing the difference of addresses |
1342 | of distinct top level objects. */ | |
5da6f168 RS |
1343 | if (new_reg_base_value[regno] != 0 |
1344 | && find_base_value (src) != new_reg_base_value[regno]) | |
9ae8ffe7 JL |
1345 | switch (GET_CODE (src)) |
1346 | { | |
2a2c8203 | 1347 | case LO_SUM: |
9ae8ffe7 JL |
1348 | case MINUS: |
1349 | if (XEXP (src, 0) != dest && XEXP (src, 1) != dest) | |
ec907dd8 | 1350 | new_reg_base_value[regno] = 0; |
9ae8ffe7 | 1351 | break; |
61f0131c R |
1352 | case PLUS: |
1353 | /* If the value we add in the PLUS is also a valid base value, | |
1354 | this might be the actual base value, and the original value | |
1355 | an index. */ | |
1356 | { | |
1357 | rtx other = NULL_RTX; | |
1358 | ||
1359 | if (XEXP (src, 0) == dest) | |
1360 | other = XEXP (src, 1); | |
1361 | else if (XEXP (src, 1) == dest) | |
1362 | other = XEXP (src, 0); | |
1363 | ||
1364 | if (! other || find_base_value (other)) | |
1365 | new_reg_base_value[regno] = 0; | |
1366 | break; | |
1367 | } | |
9ae8ffe7 | 1368 | case AND: |
481683e1 | 1369 | if (XEXP (src, 0) != dest || !CONST_INT_P (XEXP (src, 1))) |
ec907dd8 | 1370 | new_reg_base_value[regno] = 0; |
9ae8ffe7 | 1371 | break; |
9ae8ffe7 | 1372 | default: |
ec907dd8 | 1373 | new_reg_base_value[regno] = 0; |
9ae8ffe7 JL |
1374 | break; |
1375 | } | |
1376 | /* If this is the first set of a register, record the value. */ | |
1377 | else if ((regno >= FIRST_PSEUDO_REGISTER || ! fixed_regs[regno]) | |
d7c028c0 | 1378 | && ! bitmap_bit_p (reg_seen, regno) && new_reg_base_value[regno] == 0) |
ec907dd8 | 1379 | new_reg_base_value[regno] = find_base_value (src); |
9ae8ffe7 | 1380 | |
d7c028c0 | 1381 | bitmap_set_bit (reg_seen, regno); |
9ae8ffe7 JL |
1382 | } |
1383 | ||
8fd0a474 AM |
1384 | /* Return REG_BASE_VALUE for REGNO. Selective scheduler uses this to avoid |
1385 | using hard registers with non-null REG_BASE_VALUE for renaming. */ | |
1386 | rtx | |
1387 | get_reg_base_value (unsigned int regno) | |
1388 | { | |
9771b263 | 1389 | return (*reg_base_value)[regno]; |
8fd0a474 AM |
1390 | } |
1391 | ||
bb1acb3e RH |
1392 | /* If a value is known for REGNO, return it. */ |
1393 | ||
c22cacf3 | 1394 | rtx |
bb1acb3e RH |
1395 | get_reg_known_value (unsigned int regno) |
1396 | { | |
1397 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1398 | { | |
1399 | regno -= FIRST_PSEUDO_REGISTER; | |
9771b263 DN |
1400 | if (regno < vec_safe_length (reg_known_value)) |
1401 | return (*reg_known_value)[regno]; | |
bb1acb3e RH |
1402 | } |
1403 | return NULL; | |
43fe47ca JW |
1404 | } |
1405 | ||
bb1acb3e RH |
1406 | /* Set it. */ |
1407 | ||
1408 | static void | |
1409 | set_reg_known_value (unsigned int regno, rtx val) | |
1410 | { | |
1411 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1412 | { | |
1413 | regno -= FIRST_PSEUDO_REGISTER; | |
9771b263 DN |
1414 | if (regno < vec_safe_length (reg_known_value)) |
1415 | (*reg_known_value)[regno] = val; | |
bb1acb3e RH |
1416 | } |
1417 | } | |
1418 | ||
1419 | /* Similarly for reg_known_equiv_p. */ | |
1420 | ||
1421 | bool | |
1422 | get_reg_known_equiv_p (unsigned int regno) | |
1423 | { | |
1424 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1425 | { | |
1426 | regno -= FIRST_PSEUDO_REGISTER; | |
9771b263 | 1427 | if (regno < vec_safe_length (reg_known_value)) |
d7c028c0 | 1428 | return bitmap_bit_p (reg_known_equiv_p, regno); |
bb1acb3e RH |
1429 | } |
1430 | return false; | |
1431 | } | |
1432 | ||
1433 | static void | |
1434 | set_reg_known_equiv_p (unsigned int regno, bool val) | |
1435 | { | |
1436 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1437 | { | |
1438 | regno -= FIRST_PSEUDO_REGISTER; | |
9771b263 | 1439 | if (regno < vec_safe_length (reg_known_value)) |
9ff3c7ca SB |
1440 | { |
1441 | if (val) | |
d7c028c0 | 1442 | bitmap_set_bit (reg_known_equiv_p, regno); |
9ff3c7ca | 1443 | else |
d7c028c0 | 1444 | bitmap_clear_bit (reg_known_equiv_p, regno); |
9ff3c7ca | 1445 | } |
bb1acb3e RH |
1446 | } |
1447 | } | |
1448 | ||
1449 | ||
db048faf MM |
1450 | /* Returns a canonical version of X, from the point of view alias |
1451 | analysis. (For example, if X is a MEM whose address is a register, | |
1452 | and the register has a known value (say a SYMBOL_REF), then a MEM | |
1453 | whose address is the SYMBOL_REF is returned.) */ | |
1454 | ||
1455 | rtx | |
4682ae04 | 1456 | canon_rtx (rtx x) |
9ae8ffe7 JL |
1457 | { |
1458 | /* Recursively look for equivalences. */ | |
f8cfc6aa | 1459 | if (REG_P (x) && REGNO (x) >= FIRST_PSEUDO_REGISTER) |
bb1acb3e RH |
1460 | { |
1461 | rtx t = get_reg_known_value (REGNO (x)); | |
1462 | if (t == x) | |
1463 | return x; | |
1464 | if (t) | |
1465 | return canon_rtx (t); | |
1466 | } | |
1467 | ||
1468 | if (GET_CODE (x) == PLUS) | |
9ae8ffe7 JL |
1469 | { |
1470 | rtx x0 = canon_rtx (XEXP (x, 0)); | |
1471 | rtx x1 = canon_rtx (XEXP (x, 1)); | |
1472 | ||
1473 | if (x0 != XEXP (x, 0) || x1 != XEXP (x, 1)) | |
1474 | { | |
481683e1 | 1475 | if (CONST_INT_P (x0)) |
0a81f074 | 1476 | return plus_constant (GET_MODE (x), x1, INTVAL (x0)); |
481683e1 | 1477 | else if (CONST_INT_P (x1)) |
0a81f074 | 1478 | return plus_constant (GET_MODE (x), x0, INTVAL (x1)); |
38a448ca | 1479 | return gen_rtx_PLUS (GET_MODE (x), x0, x1); |
9ae8ffe7 JL |
1480 | } |
1481 | } | |
d4b60170 | 1482 | |
9ae8ffe7 JL |
1483 | /* This gives us much better alias analysis when called from |
1484 | the loop optimizer. Note we want to leave the original | |
1485 | MEM alone, but need to return the canonicalized MEM with | |
1486 | all the flags with their original values. */ | |
3c0cb5de | 1487 | else if (MEM_P (x)) |
f1ec5147 | 1488 | x = replace_equiv_address_nv (x, canon_rtx (XEXP (x, 0))); |
d4b60170 | 1489 | |
9ae8ffe7 JL |
1490 | return x; |
1491 | } | |
1492 | ||
1493 | /* Return 1 if X and Y are identical-looking rtx's. | |
45183e03 | 1494 | Expect that X and Y has been already canonicalized. |
9ae8ffe7 JL |
1495 | |
1496 | We use the data in reg_known_value above to see if two registers with | |
1497 | different numbers are, in fact, equivalent. */ | |
1498 | ||
1499 | static int | |
ed7a4b4b | 1500 | rtx_equal_for_memref_p (const_rtx x, const_rtx y) |
9ae8ffe7 | 1501 | { |
b3694847 SS |
1502 | int i; |
1503 | int j; | |
1504 | enum rtx_code code; | |
1505 | const char *fmt; | |
9ae8ffe7 JL |
1506 | |
1507 | if (x == 0 && y == 0) | |
1508 | return 1; | |
1509 | if (x == 0 || y == 0) | |
1510 | return 0; | |
d4b60170 | 1511 | |
9ae8ffe7 JL |
1512 | if (x == y) |
1513 | return 1; | |
1514 | ||
1515 | code = GET_CODE (x); | |
1516 | /* Rtx's of different codes cannot be equal. */ | |
1517 | if (code != GET_CODE (y)) | |
1518 | return 0; | |
1519 | ||
1520 | /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. | |
1521 | (REG:SI x) and (REG:HI x) are NOT equivalent. */ | |
1522 | ||
1523 | if (GET_MODE (x) != GET_MODE (y)) | |
1524 | return 0; | |
1525 | ||
db048faf MM |
1526 | /* Some RTL can be compared without a recursive examination. */ |
1527 | switch (code) | |
1528 | { | |
1529 | case REG: | |
1530 | return REGNO (x) == REGNO (y); | |
1531 | ||
1532 | case LABEL_REF: | |
1533 | return XEXP (x, 0) == XEXP (y, 0); | |
ca7fd9cd | 1534 | |
db048faf MM |
1535 | case SYMBOL_REF: |
1536 | return XSTR (x, 0) == XSTR (y, 0); | |
1537 | ||
af6236c1 AO |
1538 | case ENTRY_VALUE: |
1539 | /* This is magic, don't go through canonicalization et al. */ | |
1540 | return rtx_equal_p (ENTRY_VALUE_EXP (x), ENTRY_VALUE_EXP (y)); | |
1541 | ||
40e02b4a | 1542 | case VALUE: |
d8116890 | 1543 | CASE_CONST_UNIQUE: |
db048faf MM |
1544 | /* There's no need to compare the contents of CONST_DOUBLEs or |
1545 | CONST_INTs because pointer equality is a good enough | |
1546 | comparison for these nodes. */ | |
1547 | return 0; | |
1548 | ||
db048faf MM |
1549 | default: |
1550 | break; | |
1551 | } | |
9ae8ffe7 | 1552 | |
45183e03 JH |
1553 | /* canon_rtx knows how to handle plus. No need to canonicalize. */ |
1554 | if (code == PLUS) | |
9ae8ffe7 JL |
1555 | return ((rtx_equal_for_memref_p (XEXP (x, 0), XEXP (y, 0)) |
1556 | && rtx_equal_for_memref_p (XEXP (x, 1), XEXP (y, 1))) | |
1557 | || (rtx_equal_for_memref_p (XEXP (x, 0), XEXP (y, 1)) | |
1558 | && rtx_equal_for_memref_p (XEXP (x, 1), XEXP (y, 0)))); | |
45183e03 JH |
1559 | /* For commutative operations, the RTX match if the operand match in any |
1560 | order. Also handle the simple binary and unary cases without a loop. */ | |
ec8e098d | 1561 | if (COMMUTATIVE_P (x)) |
45183e03 JH |
1562 | { |
1563 | rtx xop0 = canon_rtx (XEXP (x, 0)); | |
1564 | rtx yop0 = canon_rtx (XEXP (y, 0)); | |
1565 | rtx yop1 = canon_rtx (XEXP (y, 1)); | |
1566 | ||
1567 | return ((rtx_equal_for_memref_p (xop0, yop0) | |
1568 | && rtx_equal_for_memref_p (canon_rtx (XEXP (x, 1)), yop1)) | |
1569 | || (rtx_equal_for_memref_p (xop0, yop1) | |
1570 | && rtx_equal_for_memref_p (canon_rtx (XEXP (x, 1)), yop0))); | |
1571 | } | |
ec8e098d | 1572 | else if (NON_COMMUTATIVE_P (x)) |
45183e03 JH |
1573 | { |
1574 | return (rtx_equal_for_memref_p (canon_rtx (XEXP (x, 0)), | |
4682ae04 | 1575 | canon_rtx (XEXP (y, 0))) |
45183e03 JH |
1576 | && rtx_equal_for_memref_p (canon_rtx (XEXP (x, 1)), |
1577 | canon_rtx (XEXP (y, 1)))); | |
1578 | } | |
ec8e098d | 1579 | else if (UNARY_P (x)) |
45183e03 | 1580 | return rtx_equal_for_memref_p (canon_rtx (XEXP (x, 0)), |
4682ae04 | 1581 | canon_rtx (XEXP (y, 0))); |
9ae8ffe7 JL |
1582 | |
1583 | /* Compare the elements. If any pair of corresponding elements | |
de12be17 JC |
1584 | fail to match, return 0 for the whole things. |
1585 | ||
1586 | Limit cases to types which actually appear in addresses. */ | |
9ae8ffe7 JL |
1587 | |
1588 | fmt = GET_RTX_FORMAT (code); | |
1589 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
1590 | { | |
1591 | switch (fmt[i]) | |
1592 | { | |
9ae8ffe7 JL |
1593 | case 'i': |
1594 | if (XINT (x, i) != XINT (y, i)) | |
1595 | return 0; | |
1596 | break; | |
1597 | ||
9ae8ffe7 JL |
1598 | case 'E': |
1599 | /* Two vectors must have the same length. */ | |
1600 | if (XVECLEN (x, i) != XVECLEN (y, i)) | |
1601 | return 0; | |
1602 | ||
1603 | /* And the corresponding elements must match. */ | |
1604 | for (j = 0; j < XVECLEN (x, i); j++) | |
45183e03 JH |
1605 | if (rtx_equal_for_memref_p (canon_rtx (XVECEXP (x, i, j)), |
1606 | canon_rtx (XVECEXP (y, i, j))) == 0) | |
9ae8ffe7 JL |
1607 | return 0; |
1608 | break; | |
1609 | ||
1610 | case 'e': | |
45183e03 JH |
1611 | if (rtx_equal_for_memref_p (canon_rtx (XEXP (x, i)), |
1612 | canon_rtx (XEXP (y, i))) == 0) | |
9ae8ffe7 JL |
1613 | return 0; |
1614 | break; | |
1615 | ||
3237ac18 AH |
1616 | /* This can happen for asm operands. */ |
1617 | case 's': | |
1618 | if (strcmp (XSTR (x, i), XSTR (y, i))) | |
1619 | return 0; | |
1620 | break; | |
1621 | ||
aee21ba9 JL |
1622 | /* This can happen for an asm which clobbers memory. */ |
1623 | case '0': | |
1624 | break; | |
1625 | ||
9ae8ffe7 JL |
1626 | /* It is believed that rtx's at this level will never |
1627 | contain anything but integers and other rtx's, | |
1628 | except for within LABEL_REFs and SYMBOL_REFs. */ | |
1629 | default: | |
298e6adc | 1630 | gcc_unreachable (); |
9ae8ffe7 JL |
1631 | } |
1632 | } | |
1633 | return 1; | |
1634 | } | |
1635 | ||
9e412ca3 | 1636 | static rtx |
4682ae04 | 1637 | find_base_term (rtx x) |
9ae8ffe7 | 1638 | { |
eab5c70a | 1639 | cselib_val *val; |
6f2ffb4b AO |
1640 | struct elt_loc_list *l, *f; |
1641 | rtx ret; | |
eab5c70a | 1642 | |
b949ea8b JW |
1643 | #if defined (FIND_BASE_TERM) |
1644 | /* Try machine-dependent ways to find the base term. */ | |
1645 | x = FIND_BASE_TERM (x); | |
1646 | #endif | |
1647 | ||
9ae8ffe7 JL |
1648 | switch (GET_CODE (x)) |
1649 | { | |
1650 | case REG: | |
1651 | return REG_BASE_VALUE (x); | |
1652 | ||
d288e53d | 1653 | case TRUNCATE: |
5932a4d4 | 1654 | /* As we do not know which address space the pointer is referring to, we can |
d4ebfa65 BE |
1655 | handle this only if the target does not support different pointer or |
1656 | address modes depending on the address space. */ | |
1657 | if (!target_default_pointer_address_modes_p ()) | |
1658 | return 0; | |
d288e53d | 1659 | if (GET_MODE_SIZE (GET_MODE (x)) < GET_MODE_SIZE (Pmode)) |
ca7fd9cd | 1660 | return 0; |
d288e53d | 1661 | /* Fall through. */ |
9ae8ffe7 | 1662 | case HIGH: |
6d849a2a JL |
1663 | case PRE_INC: |
1664 | case PRE_DEC: | |
1665 | case POST_INC: | |
1666 | case POST_DEC: | |
d288e53d DE |
1667 | case PRE_MODIFY: |
1668 | case POST_MODIFY: | |
6d849a2a JL |
1669 | return find_base_term (XEXP (x, 0)); |
1670 | ||
1abade85 RK |
1671 | case ZERO_EXTEND: |
1672 | case SIGN_EXTEND: /* Used for Alpha/NT pointers */ | |
5932a4d4 | 1673 | /* As we do not know which address space the pointer is referring to, we can |
d4ebfa65 BE |
1674 | handle this only if the target does not support different pointer or |
1675 | address modes depending on the address space. */ | |
1676 | if (!target_default_pointer_address_modes_p ()) | |
1677 | return 0; | |
1678 | ||
1abade85 RK |
1679 | { |
1680 | rtx temp = find_base_term (XEXP (x, 0)); | |
1681 | ||
5ae6cd0d | 1682 | if (temp != 0 && CONSTANT_P (temp)) |
1abade85 | 1683 | temp = convert_memory_address (Pmode, temp); |
1abade85 RK |
1684 | |
1685 | return temp; | |
1686 | } | |
1687 | ||
eab5c70a BS |
1688 | case VALUE: |
1689 | val = CSELIB_VAL_PTR (x); | |
6f2ffb4b AO |
1690 | ret = NULL_RTX; |
1691 | ||
40e02b4a | 1692 | if (!val) |
6f2ffb4b AO |
1693 | return ret; |
1694 | ||
0fe03ac3 JJ |
1695 | if (cselib_sp_based_value_p (val)) |
1696 | return static_reg_base_value[STACK_POINTER_REGNUM]; | |
1697 | ||
6f2ffb4b AO |
1698 | f = val->locs; |
1699 | /* Temporarily reset val->locs to avoid infinite recursion. */ | |
1700 | val->locs = NULL; | |
1701 | ||
1702 | for (l = f; l; l = l->next) | |
1703 | if (GET_CODE (l->loc) == VALUE | |
1704 | && CSELIB_VAL_PTR (l->loc)->locs | |
1705 | && !CSELIB_VAL_PTR (l->loc)->locs->next | |
1706 | && CSELIB_VAL_PTR (l->loc)->locs->loc == x) | |
1707 | continue; | |
1708 | else if ((ret = find_base_term (l->loc)) != 0) | |
1709 | break; | |
1710 | ||
1711 | val->locs = f; | |
1712 | return ret; | |
eab5c70a | 1713 | |
023f059b JJ |
1714 | case LO_SUM: |
1715 | /* The standard form is (lo_sum reg sym) so look only at the | |
1716 | second operand. */ | |
1717 | return find_base_term (XEXP (x, 1)); | |
1718 | ||
9ae8ffe7 JL |
1719 | case CONST: |
1720 | x = XEXP (x, 0); | |
1721 | if (GET_CODE (x) != PLUS && GET_CODE (x) != MINUS) | |
1722 | return 0; | |
938d968e | 1723 | /* Fall through. */ |
9ae8ffe7 JL |
1724 | case PLUS: |
1725 | case MINUS: | |
1726 | { | |
3c567fae JL |
1727 | rtx tmp1 = XEXP (x, 0); |
1728 | rtx tmp2 = XEXP (x, 1); | |
1729 | ||
f5143c46 | 1730 | /* This is a little bit tricky since we have to determine which of |
3c567fae JL |
1731 | the two operands represents the real base address. Otherwise this |
1732 | routine may return the index register instead of the base register. | |
1733 | ||
1734 | That may cause us to believe no aliasing was possible, when in | |
1735 | fact aliasing is possible. | |
1736 | ||
1737 | We use a few simple tests to guess the base register. Additional | |
1738 | tests can certainly be added. For example, if one of the operands | |
1739 | is a shift or multiply, then it must be the index register and the | |
1740 | other operand is the base register. */ | |
ca7fd9cd | 1741 | |
b949ea8b JW |
1742 | if (tmp1 == pic_offset_table_rtx && CONSTANT_P (tmp2)) |
1743 | return find_base_term (tmp2); | |
1744 | ||
31b0a960 | 1745 | /* If either operand is known to be a pointer, then prefer it |
3c567fae | 1746 | to determine the base term. */ |
3502dc9c | 1747 | if (REG_P (tmp1) && REG_POINTER (tmp1)) |
31b0a960 RB |
1748 | ; |
1749 | else if (REG_P (tmp2) && REG_POINTER (tmp2)) | |
7eba2d1f | 1750 | { |
31b0a960 RB |
1751 | rtx tem = tmp1; |
1752 | tmp1 = tmp2; | |
1753 | tmp2 = tem; | |
7eba2d1f | 1754 | } |
3c567fae | 1755 | |
31b0a960 RB |
1756 | /* Go ahead and find the base term for both operands. If either base |
1757 | term is from a pointer or is a named object or a special address | |
3c567fae JL |
1758 | (like an argument or stack reference), then use it for the |
1759 | base term. */ | |
481be1c4 RB |
1760 | rtx base = find_base_term (tmp1); |
1761 | if (base != NULL_RTX | |
31b0a960 | 1762 | && ((REG_P (tmp1) && REG_POINTER (tmp1)) |
481be1c4 RB |
1763 | || known_base_value_p (base))) |
1764 | return base; | |
1765 | base = find_base_term (tmp2); | |
1766 | if (base != NULL_RTX | |
31b0a960 | 1767 | && ((REG_P (tmp2) && REG_POINTER (tmp2)) |
481be1c4 RB |
1768 | || known_base_value_p (base))) |
1769 | return base; | |
3c567fae JL |
1770 | |
1771 | /* We could not determine which of the two operands was the | |
1772 | base register and which was the index. So we can determine | |
1773 | nothing from the base alias check. */ | |
1774 | return 0; | |
9ae8ffe7 JL |
1775 | } |
1776 | ||
1777 | case AND: | |
481683e1 | 1778 | if (CONST_INT_P (XEXP (x, 1)) && INTVAL (XEXP (x, 1)) != 0) |
d288e53d | 1779 | return find_base_term (XEXP (x, 0)); |
9ae8ffe7 JL |
1780 | return 0; |
1781 | ||
1782 | case SYMBOL_REF: | |
1783 | case LABEL_REF: | |
1784 | return x; | |
1785 | ||
1786 | default: | |
1787 | return 0; | |
1788 | } | |
1789 | } | |
1790 | ||
9e412ca3 RS |
1791 | /* Return true if accesses to address X may alias accesses based |
1792 | on the stack pointer. */ | |
1793 | ||
1794 | bool | |
1795 | may_be_sp_based_p (rtx x) | |
1796 | { | |
1797 | rtx base = find_base_term (x); | |
1798 | return !base || base == static_reg_base_value[STACK_POINTER_REGNUM]; | |
1799 | } | |
1800 | ||
9ae8ffe7 JL |
1801 | /* Return 0 if the addresses X and Y are known to point to different |
1802 | objects, 1 if they might be pointers to the same object. */ | |
1803 | ||
1804 | static int | |
31b0a960 RB |
1805 | base_alias_check (rtx x, rtx x_base, rtx y, rtx y_base, |
1806 | enum machine_mode x_mode, enum machine_mode y_mode) | |
9ae8ffe7 | 1807 | { |
1c72c7f6 JC |
1808 | /* If the address itself has no known base see if a known equivalent |
1809 | value has one. If either address still has no known base, nothing | |
1810 | is known about aliasing. */ | |
1811 | if (x_base == 0) | |
1812 | { | |
1813 | rtx x_c; | |
d4b60170 | 1814 | |
1c72c7f6 JC |
1815 | if (! flag_expensive_optimizations || (x_c = canon_rtx (x)) == x) |
1816 | return 1; | |
d4b60170 | 1817 | |
1c72c7f6 JC |
1818 | x_base = find_base_term (x_c); |
1819 | if (x_base == 0) | |
1820 | return 1; | |
1821 | } | |
9ae8ffe7 | 1822 | |
1c72c7f6 JC |
1823 | if (y_base == 0) |
1824 | { | |
1825 | rtx y_c; | |
1826 | if (! flag_expensive_optimizations || (y_c = canon_rtx (y)) == y) | |
1827 | return 1; | |
d4b60170 | 1828 | |
1c72c7f6 JC |
1829 | y_base = find_base_term (y_c); |
1830 | if (y_base == 0) | |
1831 | return 1; | |
1832 | } | |
1833 | ||
1834 | /* If the base addresses are equal nothing is known about aliasing. */ | |
1835 | if (rtx_equal_p (x_base, y_base)) | |
9ae8ffe7 JL |
1836 | return 1; |
1837 | ||
435da628 UB |
1838 | /* The base addresses are different expressions. If they are not accessed |
1839 | via AND, there is no conflict. We can bring knowledge of object | |
1840 | alignment into play here. For example, on alpha, "char a, b;" can | |
1841 | alias one another, though "char a; long b;" cannot. AND addesses may | |
1842 | implicitly alias surrounding objects; i.e. unaligned access in DImode | |
1843 | via AND address can alias all surrounding object types except those | |
1844 | with aligment 8 or higher. */ | |
1845 | if (GET_CODE (x) == AND && GET_CODE (y) == AND) | |
1846 | return 1; | |
1847 | if (GET_CODE (x) == AND | |
481683e1 | 1848 | && (!CONST_INT_P (XEXP (x, 1)) |
435da628 UB |
1849 | || (int) GET_MODE_UNIT_SIZE (y_mode) < -INTVAL (XEXP (x, 1)))) |
1850 | return 1; | |
1851 | if (GET_CODE (y) == AND | |
481683e1 | 1852 | && (!CONST_INT_P (XEXP (y, 1)) |
435da628 UB |
1853 | || (int) GET_MODE_UNIT_SIZE (x_mode) < -INTVAL (XEXP (y, 1)))) |
1854 | return 1; | |
1855 | ||
1856 | /* Differing symbols not accessed via AND never alias. */ | |
9ae8ffe7 | 1857 | if (GET_CODE (x_base) != ADDRESS && GET_CODE (y_base) != ADDRESS) |
435da628 | 1858 | return 0; |
9ae8ffe7 | 1859 | |
9fc37b2b | 1860 | if (unique_base_value_p (x_base) || unique_base_value_p (y_base)) |
9ae8ffe7 JL |
1861 | return 0; |
1862 | ||
0d3c82d6 | 1863 | return 1; |
9ae8ffe7 JL |
1864 | } |
1865 | ||
a5628378 AO |
1866 | /* Callback for for_each_rtx, that returns 1 upon encountering a VALUE |
1867 | whose UID is greater than the int uid that D points to. */ | |
1868 | ||
1869 | static int | |
1870 | refs_newer_value_cb (rtx *x, void *d) | |
1871 | { | |
1872 | if (GET_CODE (*x) == VALUE && CSELIB_VAL_PTR (*x)->uid > *(int *)d) | |
1873 | return 1; | |
1874 | ||
1875 | return 0; | |
1876 | } | |
1877 | ||
1878 | /* Return TRUE if EXPR refers to a VALUE whose uid is greater than | |
1879 | that of V. */ | |
1880 | ||
1881 | static bool | |
1882 | refs_newer_value_p (rtx expr, rtx v) | |
1883 | { | |
1884 | int minuid = CSELIB_VAL_PTR (v)->uid; | |
1885 | ||
1886 | return for_each_rtx (&expr, refs_newer_value_cb, &minuid); | |
1887 | } | |
1888 | ||
eab5c70a BS |
1889 | /* Convert the address X into something we can use. This is done by returning |
1890 | it unchanged unless it is a value; in the latter case we call cselib to get | |
1891 | a more useful rtx. */ | |
3bdf5ad1 | 1892 | |
a13d4ebf | 1893 | rtx |
4682ae04 | 1894 | get_addr (rtx x) |
eab5c70a BS |
1895 | { |
1896 | cselib_val *v; | |
1897 | struct elt_loc_list *l; | |
1898 | ||
1899 | if (GET_CODE (x) != VALUE) | |
1900 | return x; | |
1901 | v = CSELIB_VAL_PTR (x); | |
40e02b4a JH |
1902 | if (v) |
1903 | { | |
0f68ba3e AO |
1904 | bool have_equivs = cselib_have_permanent_equivalences (); |
1905 | if (have_equivs) | |
1906 | v = canonical_cselib_val (v); | |
40e02b4a JH |
1907 | for (l = v->locs; l; l = l->next) |
1908 | if (CONSTANT_P (l->loc)) | |
1909 | return l->loc; | |
1910 | for (l = v->locs; l; l = l->next) | |
0f68ba3e AO |
1911 | if (!REG_P (l->loc) && !MEM_P (l->loc) |
1912 | /* Avoid infinite recursion when potentially dealing with | |
1913 | var-tracking artificial equivalences, by skipping the | |
1914 | equivalences themselves, and not choosing expressions | |
1915 | that refer to newer VALUEs. */ | |
1916 | && (!have_equivs | |
1917 | || (GET_CODE (l->loc) != VALUE | |
1918 | && !refs_newer_value_p (l->loc, x)))) | |
a5628378 | 1919 | return l->loc; |
0f68ba3e AO |
1920 | if (have_equivs) |
1921 | { | |
1922 | for (l = v->locs; l; l = l->next) | |
1923 | if (REG_P (l->loc) | |
1924 | || (GET_CODE (l->loc) != VALUE | |
1925 | && !refs_newer_value_p (l->loc, x))) | |
1926 | return l->loc; | |
1927 | /* Return the canonical value. */ | |
1928 | return v->val_rtx; | |
1929 | } | |
1930 | if (v->locs) | |
1931 | return v->locs->loc; | |
40e02b4a | 1932 | } |
eab5c70a BS |
1933 | return x; |
1934 | } | |
1935 | ||
39cec1ac MH |
1936 | /* Return the address of the (N_REFS + 1)th memory reference to ADDR |
1937 | where SIZE is the size in bytes of the memory reference. If ADDR | |
1938 | is not modified by the memory reference then ADDR is returned. */ | |
1939 | ||
04e2b4d3 | 1940 | static rtx |
4682ae04 | 1941 | addr_side_effect_eval (rtx addr, int size, int n_refs) |
39cec1ac MH |
1942 | { |
1943 | int offset = 0; | |
ca7fd9cd | 1944 | |
39cec1ac MH |
1945 | switch (GET_CODE (addr)) |
1946 | { | |
1947 | case PRE_INC: | |
1948 | offset = (n_refs + 1) * size; | |
1949 | break; | |
1950 | case PRE_DEC: | |
1951 | offset = -(n_refs + 1) * size; | |
1952 | break; | |
1953 | case POST_INC: | |
1954 | offset = n_refs * size; | |
1955 | break; | |
1956 | case POST_DEC: | |
1957 | offset = -n_refs * size; | |
1958 | break; | |
1959 | ||
1960 | default: | |
1961 | return addr; | |
1962 | } | |
ca7fd9cd | 1963 | |
39cec1ac | 1964 | if (offset) |
45183e03 | 1965 | addr = gen_rtx_PLUS (GET_MODE (addr), XEXP (addr, 0), |
4789c0ce | 1966 | gen_int_mode (offset, GET_MODE (addr))); |
39cec1ac MH |
1967 | else |
1968 | addr = XEXP (addr, 0); | |
45183e03 | 1969 | addr = canon_rtx (addr); |
39cec1ac MH |
1970 | |
1971 | return addr; | |
1972 | } | |
1973 | ||
3aa03517 AO |
1974 | /* Return TRUE if an object X sized at XSIZE bytes and another object |
1975 | Y sized at YSIZE bytes, starting C bytes after X, may overlap. If | |
1976 | any of the sizes is zero, assume an overlap, otherwise use the | |
1977 | absolute value of the sizes as the actual sizes. */ | |
1978 | ||
1979 | static inline bool | |
1980 | offset_overlap_p (HOST_WIDE_INT c, int xsize, int ysize) | |
1981 | { | |
1982 | return (xsize == 0 || ysize == 0 | |
1983 | || (c >= 0 | |
1984 | ? (abs (xsize) > c) | |
1985 | : (abs (ysize) > -c))); | |
1986 | } | |
1987 | ||
f47e08d9 RG |
1988 | /* Return one if X and Y (memory addresses) reference the |
1989 | same location in memory or if the references overlap. | |
1990 | Return zero if they do not overlap, else return | |
1991 | minus one in which case they still might reference the same location. | |
1992 | ||
1993 | C is an offset accumulator. When | |
9ae8ffe7 JL |
1994 | C is nonzero, we are testing aliases between X and Y + C. |
1995 | XSIZE is the size in bytes of the X reference, | |
1996 | similarly YSIZE is the size in bytes for Y. | |
45183e03 | 1997 | Expect that canon_rtx has been already called for X and Y. |
9ae8ffe7 JL |
1998 | |
1999 | If XSIZE or YSIZE is zero, we do not know the amount of memory being | |
2000 | referenced (the reference was BLKmode), so make the most pessimistic | |
2001 | assumptions. | |
2002 | ||
c02f035f RH |
2003 | If XSIZE or YSIZE is negative, we may access memory outside the object |
2004 | being referenced as a side effect. This can happen when using AND to | |
2005 | align memory references, as is done on the Alpha. | |
2006 | ||
9ae8ffe7 | 2007 | Nice to notice that varying addresses cannot conflict with fp if no |
f47e08d9 RG |
2008 | local variables had their addresses taken, but that's too hard now. |
2009 | ||
2010 | ??? Contrary to the tree alias oracle this does not return | |
2011 | one for X + non-constant and Y + non-constant when X and Y are equal. | |
2012 | If that is fixed the TBAA hack for union type-punning can be removed. */ | |
9ae8ffe7 | 2013 | |
9ae8ffe7 | 2014 | static int |
4682ae04 | 2015 | memrefs_conflict_p (int xsize, rtx x, int ysize, rtx y, HOST_WIDE_INT c) |
9ae8ffe7 | 2016 | { |
eab5c70a | 2017 | if (GET_CODE (x) == VALUE) |
5312b066 JJ |
2018 | { |
2019 | if (REG_P (y)) | |
2020 | { | |
24f8d71e JJ |
2021 | struct elt_loc_list *l = NULL; |
2022 | if (CSELIB_VAL_PTR (x)) | |
a5628378 AO |
2023 | for (l = canonical_cselib_val (CSELIB_VAL_PTR (x))->locs; |
2024 | l; l = l->next) | |
24f8d71e JJ |
2025 | if (REG_P (l->loc) && rtx_equal_for_memref_p (l->loc, y)) |
2026 | break; | |
5312b066 JJ |
2027 | if (l) |
2028 | x = y; | |
2029 | else | |
2030 | x = get_addr (x); | |
2031 | } | |
2032 | /* Don't call get_addr if y is the same VALUE. */ | |
2033 | else if (x != y) | |
2034 | x = get_addr (x); | |
2035 | } | |
eab5c70a | 2036 | if (GET_CODE (y) == VALUE) |
5312b066 JJ |
2037 | { |
2038 | if (REG_P (x)) | |
2039 | { | |
24f8d71e JJ |
2040 | struct elt_loc_list *l = NULL; |
2041 | if (CSELIB_VAL_PTR (y)) | |
a5628378 AO |
2042 | for (l = canonical_cselib_val (CSELIB_VAL_PTR (y))->locs; |
2043 | l; l = l->next) | |
24f8d71e JJ |
2044 | if (REG_P (l->loc) && rtx_equal_for_memref_p (l->loc, x)) |
2045 | break; | |
5312b066 JJ |
2046 | if (l) |
2047 | y = x; | |
2048 | else | |
2049 | y = get_addr (y); | |
2050 | } | |
2051 | /* Don't call get_addr if x is the same VALUE. */ | |
2052 | else if (y != x) | |
2053 | y = get_addr (y); | |
2054 | } | |
9ae8ffe7 JL |
2055 | if (GET_CODE (x) == HIGH) |
2056 | x = XEXP (x, 0); | |
2057 | else if (GET_CODE (x) == LO_SUM) | |
2058 | x = XEXP (x, 1); | |
2059 | else | |
3aa03517 | 2060 | x = addr_side_effect_eval (x, abs (xsize), 0); |
9ae8ffe7 JL |
2061 | if (GET_CODE (y) == HIGH) |
2062 | y = XEXP (y, 0); | |
2063 | else if (GET_CODE (y) == LO_SUM) | |
2064 | y = XEXP (y, 1); | |
2065 | else | |
3aa03517 | 2066 | y = addr_side_effect_eval (y, abs (ysize), 0); |
9ae8ffe7 JL |
2067 | |
2068 | if (rtx_equal_for_memref_p (x, y)) | |
2069 | { | |
3aa03517 | 2070 | return offset_overlap_p (c, xsize, ysize); |
9ae8ffe7 JL |
2071 | } |
2072 | ||
6e73e666 JC |
2073 | /* This code used to check for conflicts involving stack references and |
2074 | globals but the base address alias code now handles these cases. */ | |
9ae8ffe7 JL |
2075 | |
2076 | if (GET_CODE (x) == PLUS) | |
2077 | { | |
2078 | /* The fact that X is canonicalized means that this | |
2079 | PLUS rtx is canonicalized. */ | |
2080 | rtx x0 = XEXP (x, 0); | |
2081 | rtx x1 = XEXP (x, 1); | |
2082 | ||
2083 | if (GET_CODE (y) == PLUS) | |
2084 | { | |
2085 | /* The fact that Y is canonicalized means that this | |
2086 | PLUS rtx is canonicalized. */ | |
2087 | rtx y0 = XEXP (y, 0); | |
2088 | rtx y1 = XEXP (y, 1); | |
2089 | ||
2090 | if (rtx_equal_for_memref_p (x1, y1)) | |
2091 | return memrefs_conflict_p (xsize, x0, ysize, y0, c); | |
2092 | if (rtx_equal_for_memref_p (x0, y0)) | |
2093 | return memrefs_conflict_p (xsize, x1, ysize, y1, c); | |
481683e1 | 2094 | if (CONST_INT_P (x1)) |
63be02db | 2095 | { |
481683e1 | 2096 | if (CONST_INT_P (y1)) |
63be02db JM |
2097 | return memrefs_conflict_p (xsize, x0, ysize, y0, |
2098 | c - INTVAL (x1) + INTVAL (y1)); | |
2099 | else | |
2100 | return memrefs_conflict_p (xsize, x0, ysize, y, | |
2101 | c - INTVAL (x1)); | |
2102 | } | |
481683e1 | 2103 | else if (CONST_INT_P (y1)) |
9ae8ffe7 JL |
2104 | return memrefs_conflict_p (xsize, x, ysize, y0, c + INTVAL (y1)); |
2105 | ||
f47e08d9 | 2106 | return -1; |
9ae8ffe7 | 2107 | } |
481683e1 | 2108 | else if (CONST_INT_P (x1)) |
9ae8ffe7 JL |
2109 | return memrefs_conflict_p (xsize, x0, ysize, y, c - INTVAL (x1)); |
2110 | } | |
2111 | else if (GET_CODE (y) == PLUS) | |
2112 | { | |
2113 | /* The fact that Y is canonicalized means that this | |
2114 | PLUS rtx is canonicalized. */ | |
2115 | rtx y0 = XEXP (y, 0); | |
2116 | rtx y1 = XEXP (y, 1); | |
2117 | ||
481683e1 | 2118 | if (CONST_INT_P (y1)) |
9ae8ffe7 JL |
2119 | return memrefs_conflict_p (xsize, x, ysize, y0, c + INTVAL (y1)); |
2120 | else | |
f47e08d9 | 2121 | return -1; |
9ae8ffe7 JL |
2122 | } |
2123 | ||
2124 | if (GET_CODE (x) == GET_CODE (y)) | |
2125 | switch (GET_CODE (x)) | |
2126 | { | |
2127 | case MULT: | |
2128 | { | |
2129 | /* Handle cases where we expect the second operands to be the | |
2130 | same, and check only whether the first operand would conflict | |
2131 | or not. */ | |
2132 | rtx x0, y0; | |
2133 | rtx x1 = canon_rtx (XEXP (x, 1)); | |
2134 | rtx y1 = canon_rtx (XEXP (y, 1)); | |
2135 | if (! rtx_equal_for_memref_p (x1, y1)) | |
f47e08d9 | 2136 | return -1; |
9ae8ffe7 JL |
2137 | x0 = canon_rtx (XEXP (x, 0)); |
2138 | y0 = canon_rtx (XEXP (y, 0)); | |
2139 | if (rtx_equal_for_memref_p (x0, y0)) | |
3aa03517 | 2140 | return offset_overlap_p (c, xsize, ysize); |
9ae8ffe7 JL |
2141 | |
2142 | /* Can't properly adjust our sizes. */ | |
481683e1 | 2143 | if (!CONST_INT_P (x1)) |
f47e08d9 | 2144 | return -1; |
9ae8ffe7 JL |
2145 | xsize /= INTVAL (x1); |
2146 | ysize /= INTVAL (x1); | |
2147 | c /= INTVAL (x1); | |
2148 | return memrefs_conflict_p (xsize, x0, ysize, y0, c); | |
2149 | } | |
1d300e19 KG |
2150 | |
2151 | default: | |
2152 | break; | |
9ae8ffe7 JL |
2153 | } |
2154 | ||
a9bf4fe2 AO |
2155 | /* Deal with alignment ANDs by adjusting offset and size so as to |
2156 | cover the maximum range, without taking any previously known | |
5147bf6a AO |
2157 | alignment into account. Make a size negative after such an |
2158 | adjustments, so that, if we end up with e.g. two SYMBOL_REFs, we | |
2159 | assume a potential overlap, because they may end up in contiguous | |
2160 | memory locations and the stricter-alignment access may span over | |
2161 | part of both. */ | |
481683e1 | 2162 | if (GET_CODE (x) == AND && CONST_INT_P (XEXP (x, 1))) |
56ee9281 | 2163 | { |
a9bf4fe2 AO |
2164 | HOST_WIDE_INT sc = INTVAL (XEXP (x, 1)); |
2165 | unsigned HOST_WIDE_INT uc = sc; | |
5147bf6a | 2166 | if (sc < 0 && -uc == (uc & -uc)) |
a9bf4fe2 | 2167 | { |
5147bf6a AO |
2168 | if (xsize > 0) |
2169 | xsize = -xsize; | |
3aa03517 AO |
2170 | if (xsize) |
2171 | xsize += sc + 1; | |
fe8fb1c4 | 2172 | c -= sc + 1; |
a9bf4fe2 AO |
2173 | return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)), |
2174 | ysize, y, c); | |
2175 | } | |
56ee9281 | 2176 | } |
481683e1 | 2177 | if (GET_CODE (y) == AND && CONST_INT_P (XEXP (y, 1))) |
c02f035f | 2178 | { |
a9bf4fe2 AO |
2179 | HOST_WIDE_INT sc = INTVAL (XEXP (y, 1)); |
2180 | unsigned HOST_WIDE_INT uc = sc; | |
5147bf6a | 2181 | if (sc < 0 && -uc == (uc & -uc)) |
a9bf4fe2 | 2182 | { |
5147bf6a AO |
2183 | if (ysize > 0) |
2184 | ysize = -ysize; | |
3aa03517 AO |
2185 | if (ysize) |
2186 | ysize += sc + 1; | |
fe8fb1c4 | 2187 | c += sc + 1; |
a9bf4fe2 AO |
2188 | return memrefs_conflict_p (xsize, x, |
2189 | ysize, canon_rtx (XEXP (y, 0)), c); | |
2190 | } | |
c02f035f | 2191 | } |
9ae8ffe7 JL |
2192 | |
2193 | if (CONSTANT_P (x)) | |
2194 | { | |
481683e1 | 2195 | if (CONST_INT_P (x) && CONST_INT_P (y)) |
9ae8ffe7 JL |
2196 | { |
2197 | c += (INTVAL (y) - INTVAL (x)); | |
3aa03517 | 2198 | return offset_overlap_p (c, xsize, ysize); |
9ae8ffe7 JL |
2199 | } |
2200 | ||
2201 | if (GET_CODE (x) == CONST) | |
2202 | { | |
2203 | if (GET_CODE (y) == CONST) | |
2204 | return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)), | |
2205 | ysize, canon_rtx (XEXP (y, 0)), c); | |
2206 | else | |
2207 | return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)), | |
2208 | ysize, y, c); | |
2209 | } | |
2210 | if (GET_CODE (y) == CONST) | |
2211 | return memrefs_conflict_p (xsize, x, ysize, | |
2212 | canon_rtx (XEXP (y, 0)), c); | |
2213 | ||
3aa03517 AO |
2214 | /* Assume a potential overlap for symbolic addresses that went |
2215 | through alignment adjustments (i.e., that have negative | |
2216 | sizes), because we can't know how far they are from each | |
2217 | other. */ | |
9ae8ffe7 | 2218 | if (CONSTANT_P (y)) |
3aa03517 | 2219 | return (xsize < 0 || ysize < 0 || offset_overlap_p (c, xsize, ysize)); |
9ae8ffe7 | 2220 | |
f47e08d9 | 2221 | return -1; |
9ae8ffe7 | 2222 | } |
f47e08d9 RG |
2223 | |
2224 | return -1; | |
9ae8ffe7 JL |
2225 | } |
2226 | ||
2227 | /* Functions to compute memory dependencies. | |
2228 | ||
2229 | Since we process the insns in execution order, we can build tables | |
2230 | to keep track of what registers are fixed (and not aliased), what registers | |
2231 | are varying in known ways, and what registers are varying in unknown | |
2232 | ways. | |
2233 | ||
2234 | If both memory references are volatile, then there must always be a | |
2235 | dependence between the two references, since their order can not be | |
2236 | changed. A volatile and non-volatile reference can be interchanged | |
ca7fd9cd | 2237 | though. |
9ae8ffe7 | 2238 | |
53d9622b RS |
2239 | We also must allow AND addresses, because they may generate accesses |
2240 | outside the object being referenced. This is used to generate aligned | |
2241 | addresses from unaligned addresses, for instance, the alpha | |
dc1618bc | 2242 | storeqi_unaligned pattern. */ |
9ae8ffe7 JL |
2243 | |
2244 | /* Read dependence: X is read after read in MEM takes place. There can | |
96672a3e RH |
2245 | only be a dependence here if both reads are volatile, or if either is |
2246 | an explicit barrier. */ | |
9ae8ffe7 JL |
2247 | |
2248 | int | |
4f588890 | 2249 | read_dependence (const_rtx mem, const_rtx x) |
9ae8ffe7 | 2250 | { |
96672a3e RH |
2251 | if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) |
2252 | return true; | |
2253 | if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER | |
2254 | || MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER) | |
2255 | return true; | |
2256 | return false; | |
9ae8ffe7 JL |
2257 | } |
2258 | ||
998d7deb RH |
2259 | /* Return true if we can determine that the fields referenced cannot |
2260 | overlap for any pair of objects. */ | |
2261 | ||
2262 | static bool | |
175a7536 | 2263 | nonoverlapping_component_refs_p (const_rtx rtlx, const_rtx rtly) |
998d7deb | 2264 | { |
175a7536 | 2265 | const_tree x = MEM_EXPR (rtlx), y = MEM_EXPR (rtly); |
4f588890 | 2266 | const_tree fieldx, fieldy, typex, typey, orig_y; |
998d7deb | 2267 | |
175a7536 MM |
2268 | if (!flag_strict_aliasing |
2269 | || !x || !y | |
2270 | || TREE_CODE (x) != COMPONENT_REF | |
2271 | || TREE_CODE (y) != COMPONENT_REF) | |
4c7af939 AB |
2272 | return false; |
2273 | ||
998d7deb RH |
2274 | do |
2275 | { | |
2276 | /* The comparison has to be done at a common type, since we don't | |
d6a7951f | 2277 | know how the inheritance hierarchy works. */ |
998d7deb RH |
2278 | orig_y = y; |
2279 | do | |
2280 | { | |
2281 | fieldx = TREE_OPERAND (x, 1); | |
c05a0766 | 2282 | typex = TYPE_MAIN_VARIANT (DECL_FIELD_CONTEXT (fieldx)); |
998d7deb RH |
2283 | |
2284 | y = orig_y; | |
2285 | do | |
2286 | { | |
2287 | fieldy = TREE_OPERAND (y, 1); | |
c05a0766 | 2288 | typey = TYPE_MAIN_VARIANT (DECL_FIELD_CONTEXT (fieldy)); |
998d7deb RH |
2289 | |
2290 | if (typex == typey) | |
2291 | goto found; | |
2292 | ||
2293 | y = TREE_OPERAND (y, 0); | |
2294 | } | |
2295 | while (y && TREE_CODE (y) == COMPONENT_REF); | |
2296 | ||
2297 | x = TREE_OPERAND (x, 0); | |
2298 | } | |
2299 | while (x && TREE_CODE (x) == COMPONENT_REF); | |
998d7deb | 2300 | /* Never found a common type. */ |
c05a0766 | 2301 | return false; |
998d7deb RH |
2302 | |
2303 | found: | |
ee88e690 | 2304 | /* If we're left with accessing different fields of a structure, then no |
8bed6809 | 2305 | possible overlap, unless they are both bitfields. */ |
ee88e690 | 2306 | if (TREE_CODE (typex) == RECORD_TYPE && fieldx != fieldy) |
8bed6809 | 2307 | return !(DECL_BIT_FIELD (fieldx) && DECL_BIT_FIELD (fieldy)); |
998d7deb RH |
2308 | |
2309 | /* The comparison on the current field failed. If we're accessing | |
2310 | a very nested structure, look at the next outer level. */ | |
2311 | x = TREE_OPERAND (x, 0); | |
2312 | y = TREE_OPERAND (y, 0); | |
2313 | } | |
2314 | while (x && y | |
2315 | && TREE_CODE (x) == COMPONENT_REF | |
2316 | && TREE_CODE (y) == COMPONENT_REF); | |
ca7fd9cd | 2317 | |
998d7deb RH |
2318 | return false; |
2319 | } | |
2320 | ||
2321 | /* Look at the bottom of the COMPONENT_REF list for a DECL, and return it. */ | |
2322 | ||
2323 | static tree | |
4682ae04 | 2324 | decl_for_component_ref (tree x) |
998d7deb RH |
2325 | { |
2326 | do | |
2327 | { | |
2328 | x = TREE_OPERAND (x, 0); | |
2329 | } | |
2330 | while (x && TREE_CODE (x) == COMPONENT_REF); | |
2331 | ||
2332 | return x && DECL_P (x) ? x : NULL_TREE; | |
2333 | } | |
2334 | ||
527210c4 RS |
2335 | /* Walk up the COMPONENT_REF list in X and adjust *OFFSET to compensate |
2336 | for the offset of the field reference. *KNOWN_P says whether the | |
2337 | offset is known. */ | |
998d7deb | 2338 | |
527210c4 RS |
2339 | static void |
2340 | adjust_offset_for_component_ref (tree x, bool *known_p, | |
2341 | HOST_WIDE_INT *offset) | |
998d7deb | 2342 | { |
527210c4 RS |
2343 | if (!*known_p) |
2344 | return; | |
ca7fd9cd | 2345 | do |
998d7deb | 2346 | { |
527210c4 | 2347 | tree xoffset = component_ref_field_offset (x); |
998d7deb RH |
2348 | tree field = TREE_OPERAND (x, 1); |
2349 | ||
527210c4 RS |
2350 | if (! host_integerp (xoffset, 1)) |
2351 | { | |
2352 | *known_p = false; | |
2353 | return; | |
2354 | } | |
2355 | *offset += (tree_low_cst (xoffset, 1) | |
998d7deb RH |
2356 | + (tree_low_cst (DECL_FIELD_BIT_OFFSET (field), 1) |
2357 | / BITS_PER_UNIT)); | |
2358 | ||
2359 | x = TREE_OPERAND (x, 0); | |
2360 | } | |
2361 | while (x && TREE_CODE (x) == COMPONENT_REF); | |
998d7deb RH |
2362 | } |
2363 | ||
95bd1dd7 | 2364 | /* Return nonzero if we can determine the exprs corresponding to memrefs |
c6ea834c BM |
2365 | X and Y and they do not overlap. |
2366 | If LOOP_VARIANT is set, skip offset-based disambiguation */ | |
a4311dfe | 2367 | |
2e4e39f6 | 2368 | int |
c6ea834c | 2369 | nonoverlapping_memrefs_p (const_rtx x, const_rtx y, bool loop_invariant) |
a4311dfe | 2370 | { |
998d7deb | 2371 | tree exprx = MEM_EXPR (x), expry = MEM_EXPR (y); |
a4311dfe RK |
2372 | rtx rtlx, rtly; |
2373 | rtx basex, basey; | |
527210c4 RS |
2374 | bool moffsetx_known_p, moffsety_known_p; |
2375 | HOST_WIDE_INT moffsetx = 0, moffsety = 0; | |
a4311dfe RK |
2376 | HOST_WIDE_INT offsetx = 0, offsety = 0, sizex, sizey, tem; |
2377 | ||
998d7deb RH |
2378 | /* Unless both have exprs, we can't tell anything. */ |
2379 | if (exprx == 0 || expry == 0) | |
2380 | return 0; | |
2b22e382 RG |
2381 | |
2382 | /* For spill-slot accesses make sure we have valid offsets. */ | |
2383 | if ((exprx == get_spill_slot_decl (false) | |
527210c4 | 2384 | && ! MEM_OFFSET_KNOWN_P (x)) |
2b22e382 | 2385 | || (expry == get_spill_slot_decl (false) |
527210c4 | 2386 | && ! MEM_OFFSET_KNOWN_P (y))) |
2b22e382 | 2387 | return 0; |
c22cacf3 | 2388 | |
998d7deb | 2389 | /* If the field reference test failed, look at the DECLs involved. */ |
527210c4 RS |
2390 | moffsetx_known_p = MEM_OFFSET_KNOWN_P (x); |
2391 | if (moffsetx_known_p) | |
2392 | moffsetx = MEM_OFFSET (x); | |
998d7deb RH |
2393 | if (TREE_CODE (exprx) == COMPONENT_REF) |
2394 | { | |
2e0c984c RG |
2395 | tree t = decl_for_component_ref (exprx); |
2396 | if (! t) | |
2397 | return 0; | |
527210c4 | 2398 | adjust_offset_for_component_ref (exprx, &moffsetx_known_p, &moffsetx); |
2e0c984c | 2399 | exprx = t; |
998d7deb | 2400 | } |
c67a1cf6 | 2401 | |
527210c4 RS |
2402 | moffsety_known_p = MEM_OFFSET_KNOWN_P (y); |
2403 | if (moffsety_known_p) | |
2404 | moffsety = MEM_OFFSET (y); | |
998d7deb RH |
2405 | if (TREE_CODE (expry) == COMPONENT_REF) |
2406 | { | |
2e0c984c RG |
2407 | tree t = decl_for_component_ref (expry); |
2408 | if (! t) | |
2409 | return 0; | |
527210c4 | 2410 | adjust_offset_for_component_ref (expry, &moffsety_known_p, &moffsety); |
2e0c984c | 2411 | expry = t; |
998d7deb RH |
2412 | } |
2413 | ||
2414 | if (! DECL_P (exprx) || ! DECL_P (expry)) | |
a4311dfe RK |
2415 | return 0; |
2416 | ||
1307c758 RG |
2417 | /* With invalid code we can end up storing into the constant pool. |
2418 | Bail out to avoid ICEing when creating RTL for this. | |
2419 | See gfortran.dg/lto/20091028-2_0.f90. */ | |
2420 | if (TREE_CODE (exprx) == CONST_DECL | |
2421 | || TREE_CODE (expry) == CONST_DECL) | |
2422 | return 1; | |
2423 | ||
998d7deb RH |
2424 | rtlx = DECL_RTL (exprx); |
2425 | rtly = DECL_RTL (expry); | |
a4311dfe | 2426 | |
1edcd60b RK |
2427 | /* If either RTL is not a MEM, it must be a REG or CONCAT, meaning they |
2428 | can't overlap unless they are the same because we never reuse that part | |
2429 | of the stack frame used for locals for spilled pseudos. */ | |
3c0cb5de | 2430 | if ((!MEM_P (rtlx) || !MEM_P (rtly)) |
1edcd60b | 2431 | && ! rtx_equal_p (rtlx, rtly)) |
a4311dfe RK |
2432 | return 1; |
2433 | ||
5932a4d4 | 2434 | /* If we have MEMs referring to different address spaces (which can |
09e881c9 BE |
2435 | potentially overlap), we cannot easily tell from the addresses |
2436 | whether the references overlap. */ | |
2437 | if (MEM_P (rtlx) && MEM_P (rtly) | |
2438 | && MEM_ADDR_SPACE (rtlx) != MEM_ADDR_SPACE (rtly)) | |
2439 | return 0; | |
2440 | ||
a4311dfe RK |
2441 | /* Get the base and offsets of both decls. If either is a register, we |
2442 | know both are and are the same, so use that as the base. The only | |
2443 | we can avoid overlap is if we can deduce that they are nonoverlapping | |
2444 | pieces of that decl, which is very rare. */ | |
3c0cb5de | 2445 | basex = MEM_P (rtlx) ? XEXP (rtlx, 0) : rtlx; |
481683e1 | 2446 | if (GET_CODE (basex) == PLUS && CONST_INT_P (XEXP (basex, 1))) |
a4311dfe RK |
2447 | offsetx = INTVAL (XEXP (basex, 1)), basex = XEXP (basex, 0); |
2448 | ||
3c0cb5de | 2449 | basey = MEM_P (rtly) ? XEXP (rtly, 0) : rtly; |
481683e1 | 2450 | if (GET_CODE (basey) == PLUS && CONST_INT_P (XEXP (basey, 1))) |
a4311dfe RK |
2451 | offsety = INTVAL (XEXP (basey, 1)), basey = XEXP (basey, 0); |
2452 | ||
d746694a | 2453 | /* If the bases are different, we know they do not overlap if both |
ca7fd9cd | 2454 | are constants or if one is a constant and the other a pointer into the |
d746694a RK |
2455 | stack frame. Otherwise a different base means we can't tell if they |
2456 | overlap or not. */ | |
2457 | if (! rtx_equal_p (basex, basey)) | |
ca7fd9cd KH |
2458 | return ((CONSTANT_P (basex) && CONSTANT_P (basey)) |
2459 | || (CONSTANT_P (basex) && REG_P (basey) | |
2460 | && REGNO_PTR_FRAME_P (REGNO (basey))) | |
2461 | || (CONSTANT_P (basey) && REG_P (basex) | |
2462 | && REGNO_PTR_FRAME_P (REGNO (basex)))); | |
a4311dfe | 2463 | |
c6ea834c BM |
2464 | /* Offset based disambiguation not appropriate for loop invariant */ |
2465 | if (loop_invariant) | |
2466 | return 0; | |
2467 | ||
3c0cb5de | 2468 | sizex = (!MEM_P (rtlx) ? (int) GET_MODE_SIZE (GET_MODE (rtlx)) |
f5541398 | 2469 | : MEM_SIZE_KNOWN_P (rtlx) ? MEM_SIZE (rtlx) |
a4311dfe | 2470 | : -1); |
3c0cb5de | 2471 | sizey = (!MEM_P (rtly) ? (int) GET_MODE_SIZE (GET_MODE (rtly)) |
f5541398 RS |
2472 | : MEM_SIZE_KNOWN_P (rtly) ? MEM_SIZE (rtly) |
2473 | : -1); | |
a4311dfe | 2474 | |
0af5bc3e RK |
2475 | /* If we have an offset for either memref, it can update the values computed |
2476 | above. */ | |
527210c4 RS |
2477 | if (moffsetx_known_p) |
2478 | offsetx += moffsetx, sizex -= moffsetx; | |
2479 | if (moffsety_known_p) | |
2480 | offsety += moffsety, sizey -= moffsety; | |
a4311dfe | 2481 | |
0af5bc3e | 2482 | /* If a memref has both a size and an offset, we can use the smaller size. |
efc981bb | 2483 | We can't do this if the offset isn't known because we must view this |
0af5bc3e | 2484 | memref as being anywhere inside the DECL's MEM. */ |
527210c4 | 2485 | if (MEM_SIZE_KNOWN_P (x) && moffsetx_known_p) |
f5541398 | 2486 | sizex = MEM_SIZE (x); |
527210c4 | 2487 | if (MEM_SIZE_KNOWN_P (y) && moffsety_known_p) |
f5541398 | 2488 | sizey = MEM_SIZE (y); |
a4311dfe RK |
2489 | |
2490 | /* Put the values of the memref with the lower offset in X's values. */ | |
2491 | if (offsetx > offsety) | |
2492 | { | |
2493 | tem = offsetx, offsetx = offsety, offsety = tem; | |
2494 | tem = sizex, sizex = sizey, sizey = tem; | |
2495 | } | |
2496 | ||
2497 | /* If we don't know the size of the lower-offset value, we can't tell | |
2498 | if they conflict. Otherwise, we do the test. */ | |
a6f7c915 | 2499 | return sizex >= 0 && offsety >= offsetx + sizex; |
a4311dfe RK |
2500 | } |
2501 | ||
9362286d SB |
2502 | /* Helper for true_dependence and canon_true_dependence. |
2503 | Checks for true dependence: X is read after store in MEM takes place. | |
9ae8ffe7 | 2504 | |
9362286d SB |
2505 | If MEM_CANONICALIZED is FALSE, then X_ADDR and MEM_ADDR should be |
2506 | NULL_RTX, and the canonical addresses of MEM and X are both computed | |
2507 | here. If MEM_CANONICALIZED, then MEM must be already canonicalized. | |
2508 | ||
2509 | If X_ADDR is non-NULL, it is used in preference of XEXP (x, 0). | |
2510 | ||
2511 | Returns 1 if there is a true dependence, 0 otherwise. */ | |
2512 | ||
2513 | static int | |
2514 | true_dependence_1 (const_rtx mem, enum machine_mode mem_mode, rtx mem_addr, | |
53d9622b | 2515 | const_rtx x, rtx x_addr, bool mem_canonicalized) |
9ae8ffe7 | 2516 | { |
49982682 | 2517 | rtx base; |
f47e08d9 | 2518 | int ret; |
9ae8ffe7 | 2519 | |
9362286d SB |
2520 | gcc_checking_assert (mem_canonicalized ? (mem_addr != NULL_RTX) |
2521 | : (mem_addr == NULL_RTX && x_addr == NULL_RTX)); | |
2522 | ||
9ae8ffe7 JL |
2523 | if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) |
2524 | return 1; | |
2525 | ||
c4484b8f | 2526 | /* (mem:BLK (scratch)) is a special mechanism to conflict with everything. |
ac3768f6 | 2527 | This is used in epilogue deallocation functions, and in cselib. */ |
c4484b8f RH |
2528 | if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH) |
2529 | return 1; | |
2530 | if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH) | |
2531 | return 1; | |
9cd9e512 RH |
2532 | if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER |
2533 | || MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER) | |
2534 | return 1; | |
c4484b8f | 2535 | |
389fdba0 RH |
2536 | /* Read-only memory is by definition never modified, and therefore can't |
2537 | conflict with anything. We don't expect to find read-only set on MEM, | |
41806d92 | 2538 | but stupid user tricks can produce them, so don't die. */ |
389fdba0 | 2539 | if (MEM_READONLY_P (x)) |
9ae8ffe7 JL |
2540 | return 0; |
2541 | ||
5932a4d4 | 2542 | /* If we have MEMs referring to different address spaces (which can |
09e881c9 BE |
2543 | potentially overlap), we cannot easily tell from the addresses |
2544 | whether the references overlap. */ | |
2545 | if (MEM_ADDR_SPACE (mem) != MEM_ADDR_SPACE (x)) | |
2546 | return 1; | |
2547 | ||
9362286d SB |
2548 | if (! mem_addr) |
2549 | { | |
2550 | mem_addr = XEXP (mem, 0); | |
2551 | if (mem_mode == VOIDmode) | |
2552 | mem_mode = GET_MODE (mem); | |
2553 | } | |
2554 | ||
2555 | if (! x_addr) | |
2147c71c | 2556 | { |
a522de15 SB |
2557 | x_addr = XEXP (x, 0); |
2558 | if (!((GET_CODE (x_addr) == VALUE | |
2559 | && GET_CODE (mem_addr) != VALUE | |
2560 | && reg_mentioned_p (x_addr, mem_addr)) | |
2561 | || (GET_CODE (x_addr) != VALUE | |
2562 | && GET_CODE (mem_addr) == VALUE | |
2563 | && reg_mentioned_p (mem_addr, x_addr)))) | |
2564 | { | |
2565 | x_addr = get_addr (x_addr); | |
2566 | if (! mem_canonicalized) | |
2567 | mem_addr = get_addr (mem_addr); | |
2568 | } | |
2147c71c | 2569 | } |
eab5c70a | 2570 | |
55efb413 JW |
2571 | base = find_base_term (x_addr); |
2572 | if (base && (GET_CODE (base) == LABEL_REF | |
2573 | || (GET_CODE (base) == SYMBOL_REF | |
2574 | && CONSTANT_POOL_ADDRESS_P (base)))) | |
2575 | return 0; | |
2576 | ||
31b0a960 RB |
2577 | rtx mem_base = find_base_term (mem_addr); |
2578 | if (! base_alias_check (x_addr, base, mem_addr, mem_base, | |
2579 | GET_MODE (x), mem_mode)) | |
1c72c7f6 JC |
2580 | return 0; |
2581 | ||
eab5c70a | 2582 | x_addr = canon_rtx (x_addr); |
9362286d SB |
2583 | if (!mem_canonicalized) |
2584 | mem_addr = canon_rtx (mem_addr); | |
6e73e666 | 2585 | |
f47e08d9 RG |
2586 | if ((ret = memrefs_conflict_p (GET_MODE_SIZE (mem_mode), mem_addr, |
2587 | SIZE_FOR_MODE (x), x_addr, 0)) != -1) | |
2588 | return ret; | |
2589 | ||
a95b3cc7 | 2590 | if (mems_in_disjoint_alias_sets_p (x, mem)) |
f47e08d9 RG |
2591 | return 0; |
2592 | ||
c6ea834c | 2593 | if (nonoverlapping_memrefs_p (mem, x, false)) |
0211b6ab | 2594 | return 0; |
175a7536 MM |
2595 | |
2596 | if (nonoverlapping_component_refs_p (mem, x)) | |
2597 | return 0; | |
0211b6ab | 2598 | |
55b34b5f | 2599 | return rtx_refs_may_alias_p (x, mem, true); |
a13d4ebf AM |
2600 | } |
2601 | ||
9362286d SB |
2602 | /* True dependence: X is read after store in MEM takes place. */ |
2603 | ||
2604 | int | |
53d9622b | 2605 | true_dependence (const_rtx mem, enum machine_mode mem_mode, const_rtx x) |
9362286d SB |
2606 | { |
2607 | return true_dependence_1 (mem, mem_mode, NULL_RTX, | |
53d9622b | 2608 | x, NULL_RTX, /*mem_canonicalized=*/false); |
9362286d SB |
2609 | } |
2610 | ||
a13d4ebf | 2611 | /* Canonical true dependence: X is read after store in MEM takes place. |
ca7fd9cd KH |
2612 | Variant of true_dependence which assumes MEM has already been |
2613 | canonicalized (hence we no longer do that here). | |
9362286d SB |
2614 | The mem_addr argument has been added, since true_dependence_1 computed |
2615 | this value prior to canonicalizing. */ | |
a13d4ebf AM |
2616 | |
2617 | int | |
4f588890 | 2618 | canon_true_dependence (const_rtx mem, enum machine_mode mem_mode, rtx mem_addr, |
53d9622b | 2619 | const_rtx x, rtx x_addr) |
a13d4ebf | 2620 | { |
9362286d | 2621 | return true_dependence_1 (mem, mem_mode, mem_addr, |
53d9622b | 2622 | x, x_addr, /*mem_canonicalized=*/true); |
9ae8ffe7 JL |
2623 | } |
2624 | ||
da7d8304 | 2625 | /* Returns nonzero if a write to X might alias a previous read from |
393f9fed | 2626 | (or, if WRITEP is true, a write to) MEM. |
bd280792 JR |
2627 | If X_CANONCALIZED is true, then X_ADDR is the canonicalized address of X, |
2628 | and X_MODE the mode for that access. | |
2629 | If MEM_CANONICALIZED is true, MEM is canonicalized. */ | |
9ae8ffe7 | 2630 | |
2c72b78f | 2631 | static int |
bd280792 JR |
2632 | write_dependence_p (const_rtx mem, |
2633 | const_rtx x, enum machine_mode x_mode, rtx x_addr, | |
2634 | bool mem_canonicalized, bool x_canonicalized, bool writep) | |
9ae8ffe7 | 2635 | { |
bd280792 | 2636 | rtx mem_addr; |
49982682 | 2637 | rtx base; |
f47e08d9 | 2638 | int ret; |
6e73e666 | 2639 | |
bd280792 JR |
2640 | gcc_checking_assert (x_canonicalized |
2641 | ? (x_addr != NULL_RTX && x_mode != VOIDmode) | |
2642 | : (x_addr == NULL_RTX && x_mode == VOIDmode)); | |
393f9fed | 2643 | |
9ae8ffe7 JL |
2644 | if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) |
2645 | return 1; | |
2646 | ||
c4484b8f RH |
2647 | /* (mem:BLK (scratch)) is a special mechanism to conflict with everything. |
2648 | This is used in epilogue deallocation functions. */ | |
2649 | if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH) | |
2650 | return 1; | |
2651 | if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH) | |
2652 | return 1; | |
9cd9e512 RH |
2653 | if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER |
2654 | || MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER) | |
2655 | return 1; | |
c4484b8f | 2656 | |
389fdba0 RH |
2657 | /* A read from read-only memory can't conflict with read-write memory. */ |
2658 | if (!writep && MEM_READONLY_P (mem)) | |
2659 | return 0; | |
55efb413 | 2660 | |
5932a4d4 | 2661 | /* If we have MEMs referring to different address spaces (which can |
09e881c9 BE |
2662 | potentially overlap), we cannot easily tell from the addresses |
2663 | whether the references overlap. */ | |
2664 | if (MEM_ADDR_SPACE (mem) != MEM_ADDR_SPACE (x)) | |
2665 | return 1; | |
2666 | ||
2147c71c | 2667 | mem_addr = XEXP (mem, 0); |
bd280792 | 2668 | if (!x_addr) |
2147c71c | 2669 | { |
bd280792 JR |
2670 | x_addr = XEXP (x, 0); |
2671 | if (!((GET_CODE (x_addr) == VALUE | |
2672 | && GET_CODE (mem_addr) != VALUE | |
2673 | && reg_mentioned_p (x_addr, mem_addr)) | |
2674 | || (GET_CODE (x_addr) != VALUE | |
2675 | && GET_CODE (mem_addr) == VALUE | |
2676 | && reg_mentioned_p (mem_addr, x_addr)))) | |
2677 | { | |
2678 | x_addr = get_addr (x_addr); | |
2679 | if (!mem_canonicalized) | |
2680 | mem_addr = get_addr (mem_addr); | |
2681 | } | |
2147c71c | 2682 | } |
55efb413 | 2683 | |
31b0a960 RB |
2684 | base = find_base_term (mem_addr); |
2685 | if (! writep | |
2686 | && base | |
2687 | && (GET_CODE (base) == LABEL_REF | |
2688 | || (GET_CODE (base) == SYMBOL_REF | |
2689 | && CONSTANT_POOL_ADDRESS_P (base)))) | |
2690 | return 0; | |
49982682 | 2691 | |
31b0a960 RB |
2692 | rtx x_base = find_base_term (x_addr); |
2693 | if (! base_alias_check (x_addr, x_base, mem_addr, base, GET_MODE (x), | |
eab5c70a | 2694 | GET_MODE (mem))) |
41472af8 MM |
2695 | return 0; |
2696 | ||
bd280792 | 2697 | if (!x_canonicalized) |
393f9fed | 2698 | { |
bd280792 JR |
2699 | x_addr = canon_rtx (x_addr); |
2700 | x_mode = GET_MODE (x); | |
393f9fed | 2701 | } |
bd280792 JR |
2702 | if (!mem_canonicalized) |
2703 | mem_addr = canon_rtx (mem_addr); | |
6e73e666 | 2704 | |
bd280792 JR |
2705 | if ((ret = memrefs_conflict_p (SIZE_FOR_MODE (mem), mem_addr, |
2706 | GET_MODE_SIZE (x_mode), x_addr, 0)) != -1) | |
f47e08d9 RG |
2707 | return ret; |
2708 | ||
c6ea834c | 2709 | if (nonoverlapping_memrefs_p (x, mem, false)) |
c6df88cb MM |
2710 | return 0; |
2711 | ||
55b34b5f | 2712 | return rtx_refs_may_alias_p (x, mem, false); |
c6df88cb MM |
2713 | } |
2714 | ||
2715 | /* Anti dependence: X is written after read in MEM takes place. */ | |
2716 | ||
2717 | int | |
4f588890 | 2718 | anti_dependence (const_rtx mem, const_rtx x) |
c6df88cb | 2719 | { |
bd280792 JR |
2720 | return write_dependence_p (mem, x, VOIDmode, NULL_RTX, |
2721 | /*mem_canonicalized=*/false, | |
2722 | /*x_canonicalized*/false, /*writep=*/false); | |
393f9fed JR |
2723 | } |
2724 | ||
bd280792 JR |
2725 | /* Likewise, but we already have a canonicalized MEM, and X_ADDR for X. |
2726 | Also, consider X in X_MODE (which might be from an enclosing | |
2727 | STRICT_LOW_PART / ZERO_EXTRACT). | |
2728 | If MEM_CANONICALIZED is true, MEM is canonicalized. */ | |
393f9fed JR |
2729 | |
2730 | int | |
bd280792 JR |
2731 | canon_anti_dependence (const_rtx mem, bool mem_canonicalized, |
2732 | const_rtx x, enum machine_mode x_mode, rtx x_addr) | |
393f9fed | 2733 | { |
bd280792 JR |
2734 | return write_dependence_p (mem, x, x_mode, x_addr, |
2735 | mem_canonicalized, /*x_canonicalized=*/true, | |
2736 | /*writep=*/false); | |
9ae8ffe7 JL |
2737 | } |
2738 | ||
2739 | /* Output dependence: X is written after store in MEM takes place. */ | |
2740 | ||
2741 | int | |
4f588890 | 2742 | output_dependence (const_rtx mem, const_rtx x) |
9ae8ffe7 | 2743 | { |
bd280792 JR |
2744 | return write_dependence_p (mem, x, VOIDmode, NULL_RTX, |
2745 | /*mem_canonicalized=*/false, | |
2746 | /*x_canonicalized*/false, /*writep=*/true); | |
9ae8ffe7 | 2747 | } |
c14b9960 | 2748 | \f |
6e73e666 | 2749 | |
c6ea834c BM |
2750 | |
2751 | /* Check whether X may be aliased with MEM. Don't do offset-based | |
2752 | memory disambiguation & TBAA. */ | |
2753 | int | |
2754 | may_alias_p (const_rtx mem, const_rtx x) | |
2755 | { | |
2756 | rtx x_addr, mem_addr; | |
c6ea834c BM |
2757 | |
2758 | if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) | |
2759 | return 1; | |
2760 | ||
a95b3cc7 RG |
2761 | /* (mem:BLK (scratch)) is a special mechanism to conflict with everything. |
2762 | This is used in epilogue deallocation functions. */ | |
2763 | if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH) | |
2764 | return 1; | |
2765 | if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH) | |
c6ea834c | 2766 | return 1; |
c6ea834c BM |
2767 | if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER |
2768 | || MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER) | |
2769 | return 1; | |
2770 | ||
2771 | /* Read-only memory is by definition never modified, and therefore can't | |
2772 | conflict with anything. We don't expect to find read-only set on MEM, | |
2773 | but stupid user tricks can produce them, so don't die. */ | |
2774 | if (MEM_READONLY_P (x)) | |
2775 | return 0; | |
2776 | ||
5932a4d4 | 2777 | /* If we have MEMs referring to different address spaces (which can |
c6ea834c BM |
2778 | potentially overlap), we cannot easily tell from the addresses |
2779 | whether the references overlap. */ | |
2780 | if (MEM_ADDR_SPACE (mem) != MEM_ADDR_SPACE (x)) | |
2781 | return 1; | |
2782 | ||
2783 | x_addr = XEXP (x, 0); | |
2784 | mem_addr = XEXP (mem, 0); | |
2785 | if (!((GET_CODE (x_addr) == VALUE | |
2786 | && GET_CODE (mem_addr) != VALUE | |
2787 | && reg_mentioned_p (x_addr, mem_addr)) | |
2788 | || (GET_CODE (x_addr) != VALUE | |
2789 | && GET_CODE (mem_addr) == VALUE | |
2790 | && reg_mentioned_p (mem_addr, x_addr)))) | |
2791 | { | |
2792 | x_addr = get_addr (x_addr); | |
2793 | mem_addr = get_addr (mem_addr); | |
2794 | } | |
2795 | ||
31b0a960 RB |
2796 | rtx x_base = find_base_term (x_addr); |
2797 | rtx mem_base = find_base_term (mem_addr); | |
2798 | if (! base_alias_check (x_addr, x_base, mem_addr, mem_base, | |
2799 | GET_MODE (x), GET_MODE (mem_addr))) | |
c6ea834c BM |
2800 | return 0; |
2801 | ||
2802 | x_addr = canon_rtx (x_addr); | |
2803 | mem_addr = canon_rtx (mem_addr); | |
2804 | ||
2805 | if (nonoverlapping_memrefs_p (mem, x, true)) | |
2806 | return 0; | |
2807 | ||
c6ea834c BM |
2808 | /* TBAA not valid for loop_invarint */ |
2809 | return rtx_refs_may_alias_p (x, mem, false); | |
2810 | } | |
2811 | ||
6e73e666 | 2812 | void |
b5deb7b6 | 2813 | init_alias_target (void) |
6e73e666 | 2814 | { |
b3694847 | 2815 | int i; |
6e73e666 | 2816 | |
9fc37b2b RS |
2817 | if (!arg_base_value) |
2818 | arg_base_value = gen_rtx_ADDRESS (VOIDmode, 0); | |
2819 | ||
b5deb7b6 SL |
2820 | memset (static_reg_base_value, 0, sizeof static_reg_base_value); |
2821 | ||
6e73e666 JC |
2822 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) |
2823 | /* Check whether this register can hold an incoming pointer | |
2824 | argument. FUNCTION_ARG_REGNO_P tests outgoing register | |
ec5c56db | 2825 | numbers, so translate if necessary due to register windows. */ |
6e73e666 JC |
2826 | if (FUNCTION_ARG_REGNO_P (OUTGOING_REGNO (i)) |
2827 | && HARD_REGNO_MODE_OK (i, Pmode)) | |
9fc37b2b RS |
2828 | static_reg_base_value[i] = arg_base_value; |
2829 | ||
757e8ba2 JJ |
2830 | static_reg_base_value[STACK_POINTER_REGNUM] |
2831 | = unique_base_value (UNIQUE_BASE_VALUE_SP); | |
2832 | static_reg_base_value[ARG_POINTER_REGNUM] | |
2833 | = unique_base_value (UNIQUE_BASE_VALUE_ARGP); | |
2834 | static_reg_base_value[FRAME_POINTER_REGNUM] | |
2835 | = unique_base_value (UNIQUE_BASE_VALUE_FP); | |
e3339d0f | 2836 | #if !HARD_FRAME_POINTER_IS_FRAME_POINTER |
757e8ba2 JJ |
2837 | static_reg_base_value[HARD_FRAME_POINTER_REGNUM] |
2838 | = unique_base_value (UNIQUE_BASE_VALUE_HFP); | |
bf1660a6 JL |
2839 | #endif |
2840 | } | |
2841 | ||
7b52eede JH |
2842 | /* Set MEMORY_MODIFIED when X modifies DATA (that is assumed |
2843 | to be memory reference. */ | |
2844 | static bool memory_modified; | |
2845 | static void | |
aa317c97 | 2846 | memory_modified_1 (rtx x, const_rtx pat ATTRIBUTE_UNUSED, void *data) |
7b52eede | 2847 | { |
3c0cb5de | 2848 | if (MEM_P (x)) |
7b52eede | 2849 | { |
9678086d | 2850 | if (anti_dependence (x, (const_rtx)data) || output_dependence (x, (const_rtx)data)) |
7b52eede JH |
2851 | memory_modified = true; |
2852 | } | |
2853 | } | |
2854 | ||
2855 | ||
2856 | /* Return true when INSN possibly modify memory contents of MEM | |
454ff5cb | 2857 | (i.e. address can be modified). */ |
7b52eede | 2858 | bool |
9678086d | 2859 | memory_modified_in_insn_p (const_rtx mem, const_rtx insn) |
7b52eede JH |
2860 | { |
2861 | if (!INSN_P (insn)) | |
2862 | return false; | |
2863 | memory_modified = false; | |
aa317c97 | 2864 | note_stores (PATTERN (insn), memory_modified_1, CONST_CAST_RTX(mem)); |
7b52eede JH |
2865 | return memory_modified; |
2866 | } | |
2867 | ||
a7b159a4 AH |
2868 | /* Return TRUE if the destination of a set is rtx identical to |
2869 | ITEM. */ | |
2870 | static inline bool | |
2871 | set_dest_equal_p (const_rtx set, const_rtx item) | |
2872 | { | |
2873 | rtx dest = SET_DEST (set); | |
2874 | return rtx_equal_p (dest, item); | |
2875 | } | |
2876 | ||
2877 | /* Like memory_modified_in_insn_p, but return TRUE if INSN will | |
2878 | *DEFINITELY* modify the memory contents of MEM. */ | |
2879 | bool | |
2880 | memory_must_be_modified_in_insn_p (const_rtx mem, const_rtx insn) | |
2881 | { | |
2882 | if (!INSN_P (insn)) | |
2883 | return false; | |
2884 | insn = PATTERN (insn); | |
2885 | if (GET_CODE (insn) == SET) | |
2886 | return set_dest_equal_p (insn, mem); | |
2887 | else if (GET_CODE (insn) == PARALLEL) | |
2888 | { | |
2889 | int i; | |
2890 | for (i = 0; i < XVECLEN (insn, 0); i++) | |
2891 | { | |
2892 | rtx sub = XVECEXP (insn, 0, i); | |
2893 | if (GET_CODE (sub) == SET | |
2894 | && set_dest_equal_p (sub, mem)) | |
2895 | return true; | |
2896 | } | |
2897 | } | |
2898 | return false; | |
2899 | } | |
2900 | ||
c13e8210 MM |
2901 | /* Initialize the aliasing machinery. Initialize the REG_KNOWN_VALUE |
2902 | array. */ | |
2903 | ||
9ae8ffe7 | 2904 | void |
4682ae04 | 2905 | init_alias_analysis (void) |
9ae8ffe7 | 2906 | { |
c582d54a | 2907 | unsigned int maxreg = max_reg_num (); |
ea64ef27 | 2908 | int changed, pass; |
b3694847 SS |
2909 | int i; |
2910 | unsigned int ui; | |
9ff3c7ca | 2911 | rtx insn, val; |
131db6b8 SB |
2912 | int rpo_cnt; |
2913 | int *rpo; | |
9ae8ffe7 | 2914 | |
0d446150 JH |
2915 | timevar_push (TV_ALIAS_ANALYSIS); |
2916 | ||
92390dd1 | 2917 | vec_safe_grow_cleared (reg_known_value, maxreg - FIRST_PSEUDO_REGISTER); |
9ff3c7ca | 2918 | reg_known_equiv_p = sbitmap_alloc (maxreg - FIRST_PSEUDO_REGISTER); |
dd3d1ec0 | 2919 | bitmap_clear (reg_known_equiv_p); |
9ae8ffe7 | 2920 | |
08c79682 | 2921 | /* If we have memory allocated from the previous run, use it. */ |
c582d54a | 2922 | if (old_reg_base_value) |
08c79682 KH |
2923 | reg_base_value = old_reg_base_value; |
2924 | ||
2925 | if (reg_base_value) | |
9771b263 | 2926 | reg_base_value->truncate (0); |
08c79682 | 2927 | |
9771b263 | 2928 | vec_safe_grow_cleared (reg_base_value, maxreg); |
ac606739 | 2929 | |
5ed6ace5 | 2930 | new_reg_base_value = XNEWVEC (rtx, maxreg); |
d630245f | 2931 | reg_seen = sbitmap_alloc (maxreg); |
ec907dd8 JL |
2932 | |
2933 | /* The basic idea is that each pass through this loop will use the | |
2934 | "constant" information from the previous pass to propagate alias | |
2935 | information through another level of assignments. | |
2936 | ||
131db6b8 SB |
2937 | The propagation is done on the CFG in reverse post-order, to propagate |
2938 | things forward as far as possible in each iteration. | |
2939 | ||
ec907dd8 JL |
2940 | This could get expensive if the assignment chains are long. Maybe |
2941 | we should throttle the number of iterations, possibly based on | |
6e73e666 | 2942 | the optimization level or flag_expensive_optimizations. |
ec907dd8 JL |
2943 | |
2944 | We could propagate more information in the first pass by making use | |
6fb5fa3c | 2945 | of DF_REG_DEF_COUNT to determine immediately that the alias information |
ea64ef27 JL |
2946 | for a pseudo is "constant". |
2947 | ||
2948 | A program with an uninitialized variable can cause an infinite loop | |
2949 | here. Instead of doing a full dataflow analysis to detect such problems | |
2950 | we just cap the number of iterations for the loop. | |
2951 | ||
2952 | The state of the arrays for the set chain in question does not matter | |
2953 | since the program has undefined behavior. */ | |
6e73e666 | 2954 | |
131db6b8 SB |
2955 | rpo = XNEWVEC (int, n_basic_blocks); |
2956 | rpo_cnt = pre_and_rev_post_order_compute (NULL, rpo, false); | |
2957 | ||
ea64ef27 | 2958 | pass = 0; |
6e73e666 | 2959 | do |
ec907dd8 JL |
2960 | { |
2961 | /* Assume nothing will change this iteration of the loop. */ | |
2962 | changed = 0; | |
2963 | ||
ec907dd8 | 2964 | /* We want to assign the same IDs each iteration of this loop, so |
9fc37b2b RS |
2965 | start counting from one each iteration of the loop. */ |
2966 | unique_id = 1; | |
ec907dd8 | 2967 | |
f5143c46 | 2968 | /* We're at the start of the function each iteration through the |
ec907dd8 | 2969 | loop, so we're copying arguments. */ |
83bbd9b6 | 2970 | copying_arguments = true; |
9ae8ffe7 | 2971 | |
6e73e666 | 2972 | /* Wipe the potential alias information clean for this pass. */ |
c582d54a | 2973 | memset (new_reg_base_value, 0, maxreg * sizeof (rtx)); |
8072f69c | 2974 | |
6e73e666 | 2975 | /* Wipe the reg_seen array clean. */ |
f61e445a | 2976 | bitmap_clear (reg_seen); |
9ae8ffe7 | 2977 | |
6e73e666 JC |
2978 | /* Mark all hard registers which may contain an address. |
2979 | The stack, frame and argument pointers may contain an address. | |
2980 | An argument register which can hold a Pmode value may contain | |
2981 | an address even if it is not in BASE_REGS. | |
8072f69c | 2982 | |
6e73e666 JC |
2983 | The address expression is VOIDmode for an argument and |
2984 | Pmode for other registers. */ | |
2985 | ||
7f243674 JL |
2986 | memcpy (new_reg_base_value, static_reg_base_value, |
2987 | FIRST_PSEUDO_REGISTER * sizeof (rtx)); | |
6e73e666 | 2988 | |
ec907dd8 | 2989 | /* Walk the insns adding values to the new_reg_base_value array. */ |
131db6b8 | 2990 | for (i = 0; i < rpo_cnt; i++) |
9ae8ffe7 | 2991 | { |
131db6b8 SB |
2992 | basic_block bb = BASIC_BLOCK (rpo[i]); |
2993 | FOR_BB_INSNS (bb, insn) | |
ec907dd8 | 2994 | { |
131db6b8 SB |
2995 | if (NONDEBUG_INSN_P (insn)) |
2996 | { | |
2997 | rtx note, set; | |
efc9bd41 RK |
2998 | |
2999 | #if defined (HAVE_prologue) || defined (HAVE_epilogue) | |
131db6b8 SB |
3000 | /* The prologue/epilogue insns are not threaded onto the |
3001 | insn chain until after reload has completed. Thus, | |
3002 | there is no sense wasting time checking if INSN is in | |
3003 | the prologue/epilogue until after reload has completed. */ | |
3004 | if (reload_completed | |
3005 | && prologue_epilogue_contains (insn)) | |
3006 | continue; | |
efc9bd41 RK |
3007 | #endif |
3008 | ||
131db6b8 SB |
3009 | /* If this insn has a noalias note, process it, Otherwise, |
3010 | scan for sets. A simple set will have no side effects | |
3011 | which could change the base value of any other register. */ | |
6e73e666 | 3012 | |
131db6b8 SB |
3013 | if (GET_CODE (PATTERN (insn)) == SET |
3014 | && REG_NOTES (insn) != 0 | |
3015 | && find_reg_note (insn, REG_NOALIAS, NULL_RTX)) | |
3016 | record_set (SET_DEST (PATTERN (insn)), NULL_RTX, NULL); | |
3017 | else | |
3018 | note_stores (PATTERN (insn), record_set, NULL); | |
6e73e666 | 3019 | |
131db6b8 | 3020 | set = single_set (insn); |
6e73e666 | 3021 | |
131db6b8 SB |
3022 | if (set != 0 |
3023 | && REG_P (SET_DEST (set)) | |
3024 | && REGNO (SET_DEST (set)) >= FIRST_PSEUDO_REGISTER) | |
713f41f9 | 3025 | { |
131db6b8 SB |
3026 | unsigned int regno = REGNO (SET_DEST (set)); |
3027 | rtx src = SET_SRC (set); | |
3028 | rtx t; | |
3029 | ||
3030 | note = find_reg_equal_equiv_note (insn); | |
3031 | if (note && REG_NOTE_KIND (note) == REG_EQUAL | |
3032 | && DF_REG_DEF_COUNT (regno) != 1) | |
3033 | note = NULL_RTX; | |
3034 | ||
3035 | if (note != NULL_RTX | |
3036 | && GET_CODE (XEXP (note, 0)) != EXPR_LIST | |
3037 | && ! rtx_varies_p (XEXP (note, 0), 1) | |
3038 | && ! reg_overlap_mentioned_p (SET_DEST (set), | |
3039 | XEXP (note, 0))) | |
3040 | { | |
3041 | set_reg_known_value (regno, XEXP (note, 0)); | |
3042 | set_reg_known_equiv_p (regno, | |
3043 | REG_NOTE_KIND (note) == REG_EQUIV); | |
3044 | } | |
3045 | else if (DF_REG_DEF_COUNT (regno) == 1 | |
3046 | && GET_CODE (src) == PLUS | |
3047 | && REG_P (XEXP (src, 0)) | |
3048 | && (t = get_reg_known_value (REGNO (XEXP (src, 0)))) | |
3049 | && CONST_INT_P (XEXP (src, 1))) | |
3050 | { | |
3051 | t = plus_constant (GET_MODE (src), t, | |
3052 | INTVAL (XEXP (src, 1))); | |
3053 | set_reg_known_value (regno, t); | |
3054 | set_reg_known_equiv_p (regno, false); | |
3055 | } | |
3056 | else if (DF_REG_DEF_COUNT (regno) == 1 | |
3057 | && ! rtx_varies_p (src, 1)) | |
3058 | { | |
3059 | set_reg_known_value (regno, src); | |
3060 | set_reg_known_equiv_p (regno, false); | |
3061 | } | |
713f41f9 | 3062 | } |
6e73e666 | 3063 | } |
131db6b8 SB |
3064 | else if (NOTE_P (insn) |
3065 | && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG) | |
3066 | copying_arguments = false; | |
ec907dd8 | 3067 | } |
6e73e666 | 3068 | } |
ec907dd8 | 3069 | |
6e73e666 | 3070 | /* Now propagate values from new_reg_base_value to reg_base_value. */ |
62e5bf5d | 3071 | gcc_assert (maxreg == (unsigned int) max_reg_num ()); |
c22cacf3 | 3072 | |
c582d54a | 3073 | for (ui = 0; ui < maxreg; ui++) |
6e73e666 | 3074 | { |
e51712db | 3075 | if (new_reg_base_value[ui] |
9771b263 DN |
3076 | && new_reg_base_value[ui] != (*reg_base_value)[ui] |
3077 | && ! rtx_equal_p (new_reg_base_value[ui], (*reg_base_value)[ui])) | |
ec907dd8 | 3078 | { |
9771b263 | 3079 | (*reg_base_value)[ui] = new_reg_base_value[ui]; |
6e73e666 | 3080 | changed = 1; |
ec907dd8 | 3081 | } |
9ae8ffe7 | 3082 | } |
9ae8ffe7 | 3083 | } |
6e73e666 | 3084 | while (changed && ++pass < MAX_ALIAS_LOOP_PASSES); |
131db6b8 | 3085 | XDELETEVEC (rpo); |
9ae8ffe7 JL |
3086 | |
3087 | /* Fill in the remaining entries. */ | |
9771b263 | 3088 | FOR_EACH_VEC_ELT (*reg_known_value, i, val) |
9ff3c7ca SB |
3089 | { |
3090 | int regno = i + FIRST_PSEUDO_REGISTER; | |
3091 | if (! val) | |
3092 | set_reg_known_value (regno, regno_reg_rtx[regno]); | |
3093 | } | |
9ae8ffe7 | 3094 | |
e05e2395 MM |
3095 | /* Clean up. */ |
3096 | free (new_reg_base_value); | |
ec907dd8 | 3097 | new_reg_base_value = 0; |
d630245f | 3098 | sbitmap_free (reg_seen); |
9ae8ffe7 | 3099 | reg_seen = 0; |
0d446150 | 3100 | timevar_pop (TV_ALIAS_ANALYSIS); |
9ae8ffe7 JL |
3101 | } |
3102 | ||
61630b27 JJ |
3103 | /* Equate REG_BASE_VALUE (reg1) to REG_BASE_VALUE (reg2). |
3104 | Special API for var-tracking pass purposes. */ | |
3105 | ||
3106 | void | |
3107 | vt_equate_reg_base_value (const_rtx reg1, const_rtx reg2) | |
3108 | { | |
9771b263 | 3109 | (*reg_base_value)[REGNO (reg1)] = REG_BASE_VALUE (reg2); |
61630b27 JJ |
3110 | } |
3111 | ||
9ae8ffe7 | 3112 | void |
4682ae04 | 3113 | end_alias_analysis (void) |
9ae8ffe7 | 3114 | { |
c582d54a | 3115 | old_reg_base_value = reg_base_value; |
9771b263 | 3116 | vec_free (reg_known_value); |
9ff3c7ca | 3117 | sbitmap_free (reg_known_equiv_p); |
9ae8ffe7 | 3118 | } |
e2500fed GK |
3119 | |
3120 | #include "gt-alias.h" |