]>
Commit | Line | Data |
---|---|---|
9ae8ffe7 | 1 | /* Alias analysis for GNU C |
62e5bf5d | 2 | Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, |
c75c517d | 3 | 2007, 2008, 2009, 2010 Free Software Foundation, Inc. |
9ae8ffe7 JL |
4 | Contributed by John Carr (jfc@mit.edu). |
5 | ||
1322177d | 6 | This file is part of GCC. |
9ae8ffe7 | 7 | |
1322177d LB |
8 | GCC is free software; you can redistribute it and/or modify it under |
9 | the terms of the GNU General Public License as published by the Free | |
9dcd6f09 | 10 | Software Foundation; either version 3, or (at your option) any later |
1322177d | 11 | version. |
9ae8ffe7 | 12 | |
1322177d LB |
13 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
14 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
16 | for more details. | |
9ae8ffe7 JL |
17 | |
18 | You should have received a copy of the GNU General Public License | |
9dcd6f09 NC |
19 | along with GCC; see the file COPYING3. If not see |
20 | <http://www.gnu.org/licenses/>. */ | |
9ae8ffe7 JL |
21 | |
22 | #include "config.h" | |
670ee920 | 23 | #include "system.h" |
4977bab6 ZW |
24 | #include "coretypes.h" |
25 | #include "tm.h" | |
9ae8ffe7 | 26 | #include "rtl.h" |
7790df19 | 27 | #include "tree.h" |
6baf1cc8 | 28 | #include "tm_p.h" |
49ad7cfa | 29 | #include "function.h" |
78528714 JQ |
30 | #include "alias.h" |
31 | #include "emit-rtl.h" | |
9ae8ffe7 JL |
32 | #include "regs.h" |
33 | #include "hard-reg-set.h" | |
e004f2f7 | 34 | #include "basic-block.h" |
9ae8ffe7 | 35 | #include "flags.h" |
264fac34 | 36 | #include "output.h" |
718f9c0f | 37 | #include "diagnostic-core.h" |
2e107e9e | 38 | #include "toplev.h" |
eab5c70a | 39 | #include "cselib.h" |
3932261a | 40 | #include "splay-tree.h" |
ac606739 | 41 | #include "ggc.h" |
d23c55c2 | 42 | #include "langhooks.h" |
0d446150 | 43 | #include "timevar.h" |
ab780373 | 44 | #include "target.h" |
b255a036 | 45 | #include "cgraph.h" |
ef330312 | 46 | #include "tree-pass.h" |
ea900239 | 47 | #include "ipa-type-escape.h" |
6fb5fa3c | 48 | #include "df.h" |
55b34b5f RG |
49 | #include "tree-ssa-alias.h" |
50 | #include "pointer-set.h" | |
51 | #include "tree-flow.h" | |
ea900239 DB |
52 | |
53 | /* The aliasing API provided here solves related but different problems: | |
54 | ||
c22cacf3 | 55 | Say there exists (in c) |
ea900239 DB |
56 | |
57 | struct X { | |
58 | struct Y y1; | |
59 | struct Z z2; | |
60 | } x1, *px1, *px2; | |
61 | ||
62 | struct Y y2, *py; | |
63 | struct Z z2, *pz; | |
64 | ||
65 | ||
66 | py = &px1.y1; | |
67 | px2 = &x1; | |
68 | ||
69 | Consider the four questions: | |
70 | ||
71 | Can a store to x1 interfere with px2->y1? | |
72 | Can a store to x1 interfere with px2->z2? | |
73 | (*px2).z2 | |
74 | Can a store to x1 change the value pointed to by with py? | |
75 | Can a store to x1 change the value pointed to by with pz? | |
76 | ||
77 | The answer to these questions can be yes, yes, yes, and maybe. | |
78 | ||
79 | The first two questions can be answered with a simple examination | |
80 | of the type system. If structure X contains a field of type Y then | |
81 | a store thru a pointer to an X can overwrite any field that is | |
82 | contained (recursively) in an X (unless we know that px1 != px2). | |
83 | ||
84 | The last two of the questions can be solved in the same way as the | |
85 | first two questions but this is too conservative. The observation | |
86 | is that in some cases analysis we can know if which (if any) fields | |
87 | are addressed and if those addresses are used in bad ways. This | |
88 | analysis may be language specific. In C, arbitrary operations may | |
89 | be applied to pointers. However, there is some indication that | |
90 | this may be too conservative for some C++ types. | |
91 | ||
92 | The pass ipa-type-escape does this analysis for the types whose | |
c22cacf3 | 93 | instances do not escape across the compilation boundary. |
ea900239 DB |
94 | |
95 | Historically in GCC, these two problems were combined and a single | |
96 | data structure was used to represent the solution to these | |
97 | problems. We now have two similar but different data structures, | |
98 | The data structure to solve the last two question is similar to the | |
99 | first, but does not contain have the fields in it whose address are | |
100 | never taken. For types that do escape the compilation unit, the | |
101 | data structures will have identical information. | |
102 | */ | |
3932261a MM |
103 | |
104 | /* The alias sets assigned to MEMs assist the back-end in determining | |
105 | which MEMs can alias which other MEMs. In general, two MEMs in | |
ac3d9668 RK |
106 | different alias sets cannot alias each other, with one important |
107 | exception. Consider something like: | |
3932261a | 108 | |
01d28c3f | 109 | struct S { int i; double d; }; |
3932261a MM |
110 | |
111 | a store to an `S' can alias something of either type `int' or type | |
112 | `double'. (However, a store to an `int' cannot alias a `double' | |
113 | and vice versa.) We indicate this via a tree structure that looks | |
114 | like: | |
c22cacf3 MS |
115 | struct S |
116 | / \ | |
3932261a | 117 | / \ |
c22cacf3 MS |
118 | |/_ _\| |
119 | int double | |
3932261a | 120 | |
ac3d9668 RK |
121 | (The arrows are directed and point downwards.) |
122 | In this situation we say the alias set for `struct S' is the | |
123 | `superset' and that those for `int' and `double' are `subsets'. | |
124 | ||
3bdf5ad1 RK |
125 | To see whether two alias sets can point to the same memory, we must |
126 | see if either alias set is a subset of the other. We need not trace | |
95bd1dd7 | 127 | past immediate descendants, however, since we propagate all |
3bdf5ad1 | 128 | grandchildren up one level. |
3932261a MM |
129 | |
130 | Alias set zero is implicitly a superset of all other alias sets. | |
131 | However, this is no actual entry for alias set zero. It is an | |
132 | error to attempt to explicitly construct a subset of zero. */ | |
133 | ||
7e5487a2 | 134 | struct GTY(()) alias_set_entry_d { |
3932261a | 135 | /* The alias set number, as stored in MEM_ALIAS_SET. */ |
4862826d | 136 | alias_set_type alias_set; |
3932261a | 137 | |
4c067742 RG |
138 | /* Nonzero if would have a child of zero: this effectively makes this |
139 | alias set the same as alias set zero. */ | |
140 | int has_zero_child; | |
141 | ||
3932261a | 142 | /* The children of the alias set. These are not just the immediate |
95bd1dd7 | 143 | children, but, in fact, all descendants. So, if we have: |
3932261a | 144 | |
ca7fd9cd | 145 | struct T { struct S s; float f; } |
3932261a MM |
146 | |
147 | continuing our example above, the children here will be all of | |
148 | `int', `double', `float', and `struct S'. */ | |
b604074c | 149 | splay_tree GTY((param1_is (int), param2_is (int))) children; |
b604074c | 150 | }; |
7e5487a2 | 151 | typedef struct alias_set_entry_d *alias_set_entry; |
9ae8ffe7 | 152 | |
ed7a4b4b | 153 | static int rtx_equal_for_memref_p (const_rtx, const_rtx); |
4682ae04 | 154 | static int memrefs_conflict_p (int, rtx, int, rtx, HOST_WIDE_INT); |
7bc980e1 | 155 | static void record_set (rtx, const_rtx, void *); |
4682ae04 AJ |
156 | static int base_alias_check (rtx, rtx, enum machine_mode, |
157 | enum machine_mode); | |
158 | static rtx find_base_value (rtx); | |
4f588890 | 159 | static int mems_in_disjoint_alias_sets_p (const_rtx, const_rtx); |
4682ae04 | 160 | static int insert_subset_children (splay_tree_node, void*); |
4862826d | 161 | static alias_set_entry get_alias_set_entry (alias_set_type); |
4f588890 KG |
162 | static const_rtx fixed_scalar_and_varying_struct_p (const_rtx, const_rtx, rtx, rtx, |
163 | bool (*) (const_rtx, bool)); | |
164 | static int aliases_everything_p (const_rtx); | |
165 | static bool nonoverlapping_component_refs_p (const_tree, const_tree); | |
4682ae04 AJ |
166 | static tree decl_for_component_ref (tree); |
167 | static rtx adjust_offset_for_component_ref (tree, rtx); | |
4f588890 | 168 | static int write_dependence_p (const_rtx, const_rtx, int); |
4682ae04 | 169 | |
aa317c97 | 170 | static void memory_modified_1 (rtx, const_rtx, void *); |
9ae8ffe7 JL |
171 | |
172 | /* Set up all info needed to perform alias analysis on memory references. */ | |
173 | ||
d4b60170 | 174 | /* Returns the size in bytes of the mode of X. */ |
9ae8ffe7 JL |
175 | #define SIZE_FOR_MODE(X) (GET_MODE_SIZE (GET_MODE (X))) |
176 | ||
41472af8 | 177 | /* Returns nonzero if MEM1 and MEM2 do not alias because they are in |
264fac34 MM |
178 | different alias sets. We ignore alias sets in functions making use |
179 | of variable arguments because the va_arg macros on some systems are | |
180 | not legal ANSI C. */ | |
181 | #define DIFFERENT_ALIAS_SETS_P(MEM1, MEM2) \ | |
3932261a | 182 | mems_in_disjoint_alias_sets_p (MEM1, MEM2) |
41472af8 | 183 | |
ea64ef27 | 184 | /* Cap the number of passes we make over the insns propagating alias |
ac3d9668 | 185 | information through set chains. 10 is a completely arbitrary choice. */ |
ea64ef27 | 186 | #define MAX_ALIAS_LOOP_PASSES 10 |
ca7fd9cd | 187 | |
9ae8ffe7 JL |
188 | /* reg_base_value[N] gives an address to which register N is related. |
189 | If all sets after the first add or subtract to the current value | |
190 | or otherwise modify it so it does not point to a different top level | |
191 | object, reg_base_value[N] is equal to the address part of the source | |
2a2c8203 JC |
192 | of the first set. |
193 | ||
194 | A base address can be an ADDRESS, SYMBOL_REF, or LABEL_REF. ADDRESS | |
195 | expressions represent certain special values: function arguments and | |
ca7fd9cd | 196 | the stack, frame, and argument pointers. |
b3b5ad95 JL |
197 | |
198 | The contents of an ADDRESS is not normally used, the mode of the | |
199 | ADDRESS determines whether the ADDRESS is a function argument or some | |
200 | other special value. Pointer equality, not rtx_equal_p, determines whether | |
201 | two ADDRESS expressions refer to the same base address. | |
202 | ||
203 | The only use of the contents of an ADDRESS is for determining if the | |
204 | current function performs nonlocal memory memory references for the | |
205 | purposes of marking the function as a constant function. */ | |
2a2c8203 | 206 | |
08c79682 | 207 | static GTY(()) VEC(rtx,gc) *reg_base_value; |
ac606739 | 208 | static rtx *new_reg_base_value; |
c582d54a JH |
209 | |
210 | /* We preserve the copy of old array around to avoid amount of garbage | |
211 | produced. About 8% of garbage produced were attributed to this | |
212 | array. */ | |
08c79682 | 213 | static GTY((deletable)) VEC(rtx,gc) *old_reg_base_value; |
d4b60170 | 214 | |
7bf84454 RS |
215 | #define static_reg_base_value \ |
216 | (this_target_rtl->x_static_reg_base_value) | |
bf1660a6 | 217 | |
08c79682 KH |
218 | #define REG_BASE_VALUE(X) \ |
219 | (REGNO (X) < VEC_length (rtx, reg_base_value) \ | |
220 | ? VEC_index (rtx, reg_base_value, REGNO (X)) : 0) | |
9ae8ffe7 | 221 | |
c13e8210 | 222 | /* Vector indexed by N giving the initial (unchanging) value known for |
bb1acb3e RH |
223 | pseudo-register N. This array is initialized in init_alias_analysis, |
224 | and does not change until end_alias_analysis is called. */ | |
225 | static GTY((length("reg_known_value_size"))) rtx *reg_known_value; | |
9ae8ffe7 JL |
226 | |
227 | /* Indicates number of valid entries in reg_known_value. */ | |
bb1acb3e | 228 | static GTY(()) unsigned int reg_known_value_size; |
9ae8ffe7 JL |
229 | |
230 | /* Vector recording for each reg_known_value whether it is due to a | |
231 | REG_EQUIV note. Future passes (viz., reload) may replace the | |
232 | pseudo with the equivalent expression and so we account for the | |
ac3d9668 RK |
233 | dependences that would be introduced if that happens. |
234 | ||
235 | The REG_EQUIV notes created in assign_parms may mention the arg | |
236 | pointer, and there are explicit insns in the RTL that modify the | |
237 | arg pointer. Thus we must ensure that such insns don't get | |
238 | scheduled across each other because that would invalidate the | |
239 | REG_EQUIV notes. One could argue that the REG_EQUIV notes are | |
240 | wrong, but solving the problem in the scheduler will likely give | |
241 | better code, so we do it here. */ | |
bb1acb3e | 242 | static bool *reg_known_equiv_p; |
9ae8ffe7 | 243 | |
2a2c8203 JC |
244 | /* True when scanning insns from the start of the rtl to the |
245 | NOTE_INSN_FUNCTION_BEG note. */ | |
83bbd9b6 | 246 | static bool copying_arguments; |
9ae8ffe7 | 247 | |
1a5640b4 KH |
248 | DEF_VEC_P(alias_set_entry); |
249 | DEF_VEC_ALLOC_P(alias_set_entry,gc); | |
250 | ||
3932261a | 251 | /* The splay-tree used to store the various alias set entries. */ |
1a5640b4 | 252 | static GTY (()) VEC(alias_set_entry,gc) *alias_sets; |
ac3d9668 | 253 | \f |
55b34b5f RG |
254 | /* Build a decomposed reference object for querying the alias-oracle |
255 | from the MEM rtx and store it in *REF. | |
256 | Returns false if MEM is not suitable for the alias-oracle. */ | |
257 | ||
258 | static bool | |
259 | ao_ref_from_mem (ao_ref *ref, const_rtx mem) | |
260 | { | |
261 | tree expr = MEM_EXPR (mem); | |
262 | tree base; | |
263 | ||
264 | if (!expr) | |
265 | return false; | |
266 | ||
267 | ao_ref_init (ref, expr); | |
268 | ||
269 | /* Get the base of the reference and see if we have to reject or | |
270 | adjust it. */ | |
271 | base = ao_ref_base (ref); | |
272 | if (base == NULL_TREE) | |
273 | return false; | |
274 | ||
366f945f RG |
275 | /* The tree oracle doesn't like to have these. */ |
276 | if (TREE_CODE (base) == FUNCTION_DECL | |
277 | || TREE_CODE (base) == LABEL_DECL) | |
278 | return false; | |
279 | ||
55b34b5f RG |
280 | /* If this is a pointer dereference of a non-SSA_NAME punt. |
281 | ??? We could replace it with a pointer to anything. */ | |
70f34814 RG |
282 | if ((INDIRECT_REF_P (base) |
283 | || TREE_CODE (base) == MEM_REF) | |
55b34b5f RG |
284 | && TREE_CODE (TREE_OPERAND (base, 0)) != SSA_NAME) |
285 | return false; | |
d15adbeb RG |
286 | if (TREE_CODE (base) == TARGET_MEM_REF |
287 | && TMR_BASE (base) | |
288 | && TREE_CODE (TMR_BASE (base)) != SSA_NAME) | |
289 | return false; | |
55b34b5f RG |
290 | |
291 | /* If this is a reference based on a partitioned decl replace the | |
292 | base with an INDIRECT_REF of the pointer representative we | |
293 | created during stack slot partitioning. */ | |
294 | if (TREE_CODE (base) == VAR_DECL | |
295 | && ! TREE_STATIC (base) | |
296 | && cfun->gimple_df->decls_to_pointers != NULL) | |
297 | { | |
298 | void *namep; | |
299 | namep = pointer_map_contains (cfun->gimple_df->decls_to_pointers, base); | |
300 | if (namep) | |
70f34814 | 301 | ref->base = build_simple_mem_ref (*(tree *)namep); |
55b34b5f | 302 | } |
d15adbeb RG |
303 | else if (TREE_CODE (base) == TARGET_MEM_REF |
304 | && TMR_SYMBOL (base) | |
23a534a1 RG |
305 | && TREE_CODE (TREE_OPERAND (TMR_SYMBOL (base), 0)) == VAR_DECL |
306 | && ! TREE_STATIC (TREE_OPERAND (TMR_SYMBOL (base), 0)) | |
d15adbeb RG |
307 | && cfun->gimple_df->decls_to_pointers != NULL) |
308 | { | |
309 | void *namep; | |
310 | namep = pointer_map_contains (cfun->gimple_df->decls_to_pointers, | |
23a534a1 | 311 | TREE_OPERAND (TMR_SYMBOL (base), 0)); |
d15adbeb RG |
312 | if (namep) |
313 | ref->base = build_simple_mem_ref (*(tree *)namep); | |
314 | } | |
55b34b5f RG |
315 | |
316 | ref->ref_alias_set = MEM_ALIAS_SET (mem); | |
317 | ||
366f945f RG |
318 | /* If MEM_OFFSET or MEM_SIZE are NULL we have to punt. |
319 | Keep points-to related information though. */ | |
320 | if (!MEM_OFFSET (mem) | |
321 | || !MEM_SIZE (mem)) | |
322 | { | |
323 | ref->ref = NULL_TREE; | |
324 | ref->offset = 0; | |
325 | ref->size = -1; | |
326 | ref->max_size = -1; | |
327 | return true; | |
328 | } | |
329 | ||
b0e96404 RG |
330 | /* If the base decl is a parameter we can have negative MEM_OFFSET in |
331 | case of promoted subregs on bigendian targets. Trust the MEM_EXPR | |
332 | here. */ | |
333 | if (INTVAL (MEM_OFFSET (mem)) < 0 | |
334 | && ((INTVAL (MEM_SIZE (mem)) + INTVAL (MEM_OFFSET (mem))) | |
335 | * BITS_PER_UNIT) == ref->size) | |
336 | return true; | |
337 | ||
338 | ref->offset += INTVAL (MEM_OFFSET (mem)) * BITS_PER_UNIT; | |
339 | ref->size = INTVAL (MEM_SIZE (mem)) * BITS_PER_UNIT; | |
340 | ||
341 | /* The MEM may extend into adjacent fields, so adjust max_size if | |
342 | necessary. */ | |
343 | if (ref->max_size != -1 | |
344 | && ref->size > ref->max_size) | |
345 | ref->max_size = ref->size; | |
346 | ||
347 | /* If MEM_OFFSET and MEM_SIZE get us outside of the base object of | |
348 | the MEM_EXPR punt. This happens for STRICT_ALIGNMENT targets a lot. */ | |
349 | if (MEM_EXPR (mem) != get_spill_slot_decl (false) | |
350 | && (ref->offset < 0 | |
351 | || (DECL_P (ref->base) | |
352 | && (!host_integerp (DECL_SIZE (ref->base), 1) | |
353 | || (TREE_INT_CST_LOW (DECL_SIZE ((ref->base))) | |
354 | < (unsigned HOST_WIDE_INT)(ref->offset + ref->size)))))) | |
355 | return false; | |
55b34b5f RG |
356 | |
357 | return true; | |
358 | } | |
359 | ||
360 | /* Query the alias-oracle on whether the two memory rtx X and MEM may | |
361 | alias. If TBAA_P is set also apply TBAA. Returns true if the | |
362 | two rtxen may alias, false otherwise. */ | |
363 | ||
364 | static bool | |
365 | rtx_refs_may_alias_p (const_rtx x, const_rtx mem, bool tbaa_p) | |
366 | { | |
367 | ao_ref ref1, ref2; | |
368 | ||
369 | if (!ao_ref_from_mem (&ref1, x) | |
370 | || !ao_ref_from_mem (&ref2, mem)) | |
371 | return true; | |
372 | ||
55e3bc4c RG |
373 | return refs_may_alias_p_1 (&ref1, &ref2, |
374 | tbaa_p | |
375 | && MEM_ALIAS_SET (x) != 0 | |
376 | && MEM_ALIAS_SET (mem) != 0); | |
55b34b5f RG |
377 | } |
378 | ||
3932261a MM |
379 | /* Returns a pointer to the alias set entry for ALIAS_SET, if there is |
380 | such an entry, or NULL otherwise. */ | |
381 | ||
9ddb66ca | 382 | static inline alias_set_entry |
4862826d | 383 | get_alias_set_entry (alias_set_type alias_set) |
3932261a | 384 | { |
1a5640b4 | 385 | return VEC_index (alias_set_entry, alias_sets, alias_set); |
3932261a MM |
386 | } |
387 | ||
ac3d9668 RK |
388 | /* Returns nonzero if the alias sets for MEM1 and MEM2 are such that |
389 | the two MEMs cannot alias each other. */ | |
3932261a | 390 | |
9ddb66ca | 391 | static inline int |
4f588890 | 392 | mems_in_disjoint_alias_sets_p (const_rtx mem1, const_rtx mem2) |
3932261a | 393 | { |
3932261a MM |
394 | /* Perform a basic sanity check. Namely, that there are no alias sets |
395 | if we're not using strict aliasing. This helps to catch bugs | |
396 | whereby someone uses PUT_CODE, but doesn't clear MEM_ALIAS_SET, or | |
397 | where a MEM is allocated in some way other than by the use of | |
398 | gen_rtx_MEM, and the MEM_ALIAS_SET is not cleared. If we begin to | |
399 | use alias sets to indicate that spilled registers cannot alias each | |
400 | other, we might need to remove this check. */ | |
298e6adc NS |
401 | gcc_assert (flag_strict_aliasing |
402 | || (!MEM_ALIAS_SET (mem1) && !MEM_ALIAS_SET (mem2))); | |
3932261a | 403 | |
1da68f56 RK |
404 | return ! alias_sets_conflict_p (MEM_ALIAS_SET (mem1), MEM_ALIAS_SET (mem2)); |
405 | } | |
3932261a | 406 | |
1da68f56 RK |
407 | /* Insert the NODE into the splay tree given by DATA. Used by |
408 | record_alias_subset via splay_tree_foreach. */ | |
409 | ||
410 | static int | |
4682ae04 | 411 | insert_subset_children (splay_tree_node node, void *data) |
1da68f56 RK |
412 | { |
413 | splay_tree_insert ((splay_tree) data, node->key, node->value); | |
414 | ||
415 | return 0; | |
416 | } | |
417 | ||
c58936b6 DB |
418 | /* Return true if the first alias set is a subset of the second. */ |
419 | ||
420 | bool | |
4862826d | 421 | alias_set_subset_of (alias_set_type set1, alias_set_type set2) |
c58936b6 DB |
422 | { |
423 | alias_set_entry ase; | |
424 | ||
425 | /* Everything is a subset of the "aliases everything" set. */ | |
426 | if (set2 == 0) | |
427 | return true; | |
428 | ||
429 | /* Otherwise, check if set1 is a subset of set2. */ | |
430 | ase = get_alias_set_entry (set2); | |
431 | if (ase != 0 | |
038a39d1 | 432 | && (ase->has_zero_child |
a7a512be RG |
433 | || splay_tree_lookup (ase->children, |
434 | (splay_tree_key) set1))) | |
c58936b6 DB |
435 | return true; |
436 | return false; | |
437 | } | |
438 | ||
1da68f56 RK |
439 | /* Return 1 if the two specified alias sets may conflict. */ |
440 | ||
441 | int | |
4862826d | 442 | alias_sets_conflict_p (alias_set_type set1, alias_set_type set2) |
1da68f56 RK |
443 | { |
444 | alias_set_entry ase; | |
445 | ||
836f7794 EB |
446 | /* The easy case. */ |
447 | if (alias_sets_must_conflict_p (set1, set2)) | |
1da68f56 | 448 | return 1; |
3932261a | 449 | |
3bdf5ad1 | 450 | /* See if the first alias set is a subset of the second. */ |
1da68f56 | 451 | ase = get_alias_set_entry (set1); |
2bf105ab RK |
452 | if (ase != 0 |
453 | && (ase->has_zero_child | |
454 | || splay_tree_lookup (ase->children, | |
1da68f56 RK |
455 | (splay_tree_key) set2))) |
456 | return 1; | |
3932261a MM |
457 | |
458 | /* Now do the same, but with the alias sets reversed. */ | |
1da68f56 | 459 | ase = get_alias_set_entry (set2); |
2bf105ab RK |
460 | if (ase != 0 |
461 | && (ase->has_zero_child | |
462 | || splay_tree_lookup (ase->children, | |
1da68f56 RK |
463 | (splay_tree_key) set1))) |
464 | return 1; | |
3932261a | 465 | |
1da68f56 | 466 | /* The two alias sets are distinct and neither one is the |
836f7794 | 467 | child of the other. Therefore, they cannot conflict. */ |
1da68f56 | 468 | return 0; |
3932261a | 469 | } |
5399d643 | 470 | |
836f7794 | 471 | /* Return 1 if the two specified alias sets will always conflict. */ |
5399d643 JW |
472 | |
473 | int | |
4862826d | 474 | alias_sets_must_conflict_p (alias_set_type set1, alias_set_type set2) |
5399d643 JW |
475 | { |
476 | if (set1 == 0 || set2 == 0 || set1 == set2) | |
477 | return 1; | |
478 | ||
479 | return 0; | |
480 | } | |
481 | ||
1da68f56 RK |
482 | /* Return 1 if any MEM object of type T1 will always conflict (using the |
483 | dependency routines in this file) with any MEM object of type T2. | |
484 | This is used when allocating temporary storage. If T1 and/or T2 are | |
485 | NULL_TREE, it means we know nothing about the storage. */ | |
486 | ||
487 | int | |
4682ae04 | 488 | objects_must_conflict_p (tree t1, tree t2) |
1da68f56 | 489 | { |
4862826d | 490 | alias_set_type set1, set2; |
82d610ec | 491 | |
e8ea2809 RK |
492 | /* If neither has a type specified, we don't know if they'll conflict |
493 | because we may be using them to store objects of various types, for | |
494 | example the argument and local variables areas of inlined functions. */ | |
981a4c34 | 495 | if (t1 == 0 && t2 == 0) |
e8ea2809 RK |
496 | return 0; |
497 | ||
1da68f56 RK |
498 | /* If they are the same type, they must conflict. */ |
499 | if (t1 == t2 | |
500 | /* Likewise if both are volatile. */ | |
501 | || (t1 != 0 && TYPE_VOLATILE (t1) && t2 != 0 && TYPE_VOLATILE (t2))) | |
502 | return 1; | |
503 | ||
82d610ec RK |
504 | set1 = t1 ? get_alias_set (t1) : 0; |
505 | set2 = t2 ? get_alias_set (t2) : 0; | |
1da68f56 | 506 | |
836f7794 EB |
507 | /* We can't use alias_sets_conflict_p because we must make sure |
508 | that every subtype of t1 will conflict with every subtype of | |
82d610ec RK |
509 | t2 for which a pair of subobjects of these respective subtypes |
510 | overlaps on the stack. */ | |
836f7794 | 511 | return alias_sets_must_conflict_p (set1, set2); |
1da68f56 RK |
512 | } |
513 | \f | |
2039d7aa RH |
514 | /* Return true if all nested component references handled by |
515 | get_inner_reference in T are such that we should use the alias set | |
516 | provided by the object at the heart of T. | |
517 | ||
518 | This is true for non-addressable components (which don't have their | |
519 | own alias set), as well as components of objects in alias set zero. | |
520 | This later point is a special case wherein we wish to override the | |
521 | alias set used by the component, but we don't have per-FIELD_DECL | |
522 | assignable alias sets. */ | |
523 | ||
524 | bool | |
22ea9ec0 | 525 | component_uses_parent_alias_set (const_tree t) |
6e24b709 | 526 | { |
afe84921 RH |
527 | while (1) |
528 | { | |
2039d7aa | 529 | /* If we're at the end, it vacuously uses its own alias set. */ |
afe84921 | 530 | if (!handled_component_p (t)) |
2039d7aa | 531 | return false; |
afe84921 RH |
532 | |
533 | switch (TREE_CODE (t)) | |
534 | { | |
535 | case COMPONENT_REF: | |
536 | if (DECL_NONADDRESSABLE_P (TREE_OPERAND (t, 1))) | |
2039d7aa | 537 | return true; |
afe84921 RH |
538 | break; |
539 | ||
540 | case ARRAY_REF: | |
541 | case ARRAY_RANGE_REF: | |
542 | if (TYPE_NONALIASED_COMPONENT (TREE_TYPE (TREE_OPERAND (t, 0)))) | |
2039d7aa | 543 | return true; |
afe84921 RH |
544 | break; |
545 | ||
546 | case REALPART_EXPR: | |
547 | case IMAGPART_EXPR: | |
548 | break; | |
549 | ||
550 | default: | |
551 | /* Bitfields and casts are never addressable. */ | |
2039d7aa | 552 | return true; |
afe84921 RH |
553 | } |
554 | ||
555 | t = TREE_OPERAND (t, 0); | |
2039d7aa RH |
556 | if (get_alias_set (TREE_TYPE (t)) == 0) |
557 | return true; | |
afe84921 | 558 | } |
6e24b709 RK |
559 | } |
560 | ||
5006671f RG |
561 | /* Return the alias set for the memory pointed to by T, which may be |
562 | either a type or an expression. Return -1 if there is nothing | |
563 | special about dereferencing T. */ | |
564 | ||
565 | static alias_set_type | |
566 | get_deref_alias_set_1 (tree t) | |
567 | { | |
568 | /* If we're not doing any alias analysis, just assume everything | |
569 | aliases everything else. */ | |
570 | if (!flag_strict_aliasing) | |
571 | return 0; | |
572 | ||
5b21f0f3 | 573 | /* All we care about is the type. */ |
5006671f | 574 | if (! TYPE_P (t)) |
5b21f0f3 | 575 | t = TREE_TYPE (t); |
5006671f RG |
576 | |
577 | /* If we have an INDIRECT_REF via a void pointer, we don't | |
578 | know anything about what that might alias. Likewise if the | |
579 | pointer is marked that way. */ | |
580 | if (TREE_CODE (TREE_TYPE (t)) == VOID_TYPE | |
581 | || TYPE_REF_CAN_ALIAS_ALL (t)) | |
582 | return 0; | |
583 | ||
584 | return -1; | |
585 | } | |
586 | ||
587 | /* Return the alias set for the memory pointed to by T, which may be | |
588 | either a type or an expression. */ | |
589 | ||
590 | alias_set_type | |
591 | get_deref_alias_set (tree t) | |
592 | { | |
593 | alias_set_type set = get_deref_alias_set_1 (t); | |
594 | ||
595 | /* Fall back to the alias-set of the pointed-to type. */ | |
596 | if (set == -1) | |
597 | { | |
598 | if (! TYPE_P (t)) | |
599 | t = TREE_TYPE (t); | |
600 | set = get_alias_set (TREE_TYPE (t)); | |
601 | } | |
602 | ||
603 | return set; | |
604 | } | |
605 | ||
3bdf5ad1 RK |
606 | /* Return the alias set for T, which may be either a type or an |
607 | expression. Call language-specific routine for help, if needed. */ | |
608 | ||
4862826d | 609 | alias_set_type |
4682ae04 | 610 | get_alias_set (tree t) |
3bdf5ad1 | 611 | { |
4862826d | 612 | alias_set_type set; |
3bdf5ad1 RK |
613 | |
614 | /* If we're not doing any alias analysis, just assume everything | |
615 | aliases everything else. Also return 0 if this or its type is | |
616 | an error. */ | |
617 | if (! flag_strict_aliasing || t == error_mark_node | |
618 | || (! TYPE_P (t) | |
619 | && (TREE_TYPE (t) == 0 || TREE_TYPE (t) == error_mark_node))) | |
620 | return 0; | |
621 | ||
622 | /* We can be passed either an expression or a type. This and the | |
f47e9b4e RK |
623 | language-specific routine may make mutually-recursive calls to each other |
624 | to figure out what to do. At each juncture, we see if this is a tree | |
625 | that the language may need to handle specially. First handle things that | |
738cc472 | 626 | aren't types. */ |
f824e5c3 | 627 | if (! TYPE_P (t)) |
3bdf5ad1 | 628 | { |
ebcc3d93 | 629 | tree inner; |
738cc472 | 630 | |
70f34814 RG |
631 | /* Give the language a chance to do something with this tree |
632 | before we look at it. */ | |
8ac61af7 | 633 | STRIP_NOPS (t); |
ae2bcd98 | 634 | set = lang_hooks.get_alias_set (t); |
8ac61af7 RK |
635 | if (set != -1) |
636 | return set; | |
637 | ||
70f34814 | 638 | /* Get the base object of the reference. */ |
ebcc3d93 | 639 | inner = t; |
6fce44af | 640 | while (handled_component_p (inner)) |
738cc472 | 641 | { |
70f34814 RG |
642 | /* If there is a VIEW_CONVERT_EXPR in the chain we cannot use |
643 | the type of any component references that wrap it to | |
644 | determine the alias-set. */ | |
645 | if (TREE_CODE (inner) == VIEW_CONVERT_EXPR) | |
646 | t = TREE_OPERAND (inner, 0); | |
6fce44af | 647 | inner = TREE_OPERAND (inner, 0); |
738cc472 RK |
648 | } |
649 | ||
70f34814 RG |
650 | /* Handle pointer dereferences here, they can override the |
651 | alias-set. */ | |
1b096a0a | 652 | if (INDIRECT_REF_P (inner)) |
738cc472 | 653 | { |
5006671f RG |
654 | set = get_deref_alias_set_1 (TREE_OPERAND (inner, 0)); |
655 | if (set != -1) | |
656 | return set; | |
738cc472 | 657 | } |
4b228e61 RG |
658 | else if (TREE_CODE (inner) == TARGET_MEM_REF) |
659 | return get_deref_alias_set (TMR_OFFSET (inner)); | |
70f34814 RG |
660 | else if (TREE_CODE (inner) == MEM_REF) |
661 | { | |
662 | set = get_deref_alias_set_1 (TREE_OPERAND (inner, 1)); | |
663 | if (set != -1) | |
664 | return set; | |
665 | } | |
666 | ||
667 | /* If the innermost reference is a MEM_REF that has a | |
668 | conversion embedded treat it like a VIEW_CONVERT_EXPR above, | |
669 | using the memory access type for determining the alias-set. */ | |
670 | if (TREE_CODE (inner) == MEM_REF | |
7be7d292 EB |
671 | && TYPE_MAIN_VARIANT (TREE_TYPE (inner)) |
672 | != TYPE_MAIN_VARIANT | |
673 | (TREE_TYPE (TREE_TYPE (TREE_OPERAND (inner, 1))))) | |
70f34814 | 674 | return get_deref_alias_set (TREE_OPERAND (inner, 1)); |
738cc472 RK |
675 | |
676 | /* Otherwise, pick up the outermost object that we could have a pointer | |
6fce44af | 677 | to, processing conversions as above. */ |
2039d7aa | 678 | while (component_uses_parent_alias_set (t)) |
f47e9b4e | 679 | { |
6fce44af | 680 | t = TREE_OPERAND (t, 0); |
8ac61af7 RK |
681 | STRIP_NOPS (t); |
682 | } | |
f824e5c3 | 683 | |
738cc472 RK |
684 | /* If we've already determined the alias set for a decl, just return |
685 | it. This is necessary for C++ anonymous unions, whose component | |
686 | variables don't look like union members (boo!). */ | |
5755cd38 | 687 | if (TREE_CODE (t) == VAR_DECL |
3c0cb5de | 688 | && DECL_RTL_SET_P (t) && MEM_P (DECL_RTL (t))) |
5755cd38 JM |
689 | return MEM_ALIAS_SET (DECL_RTL (t)); |
690 | ||
f824e5c3 RK |
691 | /* Now all we care about is the type. */ |
692 | t = TREE_TYPE (t); | |
3bdf5ad1 RK |
693 | } |
694 | ||
3bdf5ad1 | 695 | /* Variant qualifiers don't affect the alias set, so get the main |
daad0278 | 696 | variant. */ |
3bdf5ad1 | 697 | t = TYPE_MAIN_VARIANT (t); |
daad0278 RG |
698 | |
699 | /* Always use the canonical type as well. If this is a type that | |
700 | requires structural comparisons to identify compatible types | |
701 | use alias set zero. */ | |
702 | if (TYPE_STRUCTURAL_EQUALITY_P (t)) | |
cb9c2485 JM |
703 | { |
704 | /* Allow the language to specify another alias set for this | |
705 | type. */ | |
706 | set = lang_hooks.get_alias_set (t); | |
707 | if (set != -1) | |
708 | return set; | |
709 | return 0; | |
710 | } | |
7be7d292 | 711 | |
daad0278 | 712 | t = TYPE_CANONICAL (t); |
7be7d292 | 713 | |
daad0278 RG |
714 | /* Canonical types shouldn't form a tree nor should the canonical |
715 | type require structural equality checks. */ | |
7be7d292 EB |
716 | gcc_checking_assert (TYPE_CANONICAL (t) == t |
717 | && !TYPE_STRUCTURAL_EQUALITY_P (t)); | |
daad0278 RG |
718 | |
719 | /* If this is a type with a known alias set, return it. */ | |
738cc472 | 720 | if (TYPE_ALIAS_SET_KNOWN_P (t)) |
3bdf5ad1 RK |
721 | return TYPE_ALIAS_SET (t); |
722 | ||
36784d0e RG |
723 | /* We don't want to set TYPE_ALIAS_SET for incomplete types. */ |
724 | if (!COMPLETE_TYPE_P (t)) | |
725 | { | |
726 | /* For arrays with unknown size the conservative answer is the | |
727 | alias set of the element type. */ | |
728 | if (TREE_CODE (t) == ARRAY_TYPE) | |
729 | return get_alias_set (TREE_TYPE (t)); | |
730 | ||
731 | /* But return zero as a conservative answer for incomplete types. */ | |
732 | return 0; | |
733 | } | |
734 | ||
3bdf5ad1 | 735 | /* See if the language has special handling for this type. */ |
ae2bcd98 | 736 | set = lang_hooks.get_alias_set (t); |
8ac61af7 | 737 | if (set != -1) |
738cc472 | 738 | return set; |
2bf105ab | 739 | |
3bdf5ad1 RK |
740 | /* There are no objects of FUNCTION_TYPE, so there's no point in |
741 | using up an alias set for them. (There are, of course, pointers | |
742 | and references to functions, but that's different.) */ | |
7be7d292 | 743 | else if (TREE_CODE (t) == FUNCTION_TYPE || TREE_CODE (t) == METHOD_TYPE) |
3bdf5ad1 | 744 | set = 0; |
74d86f4f RH |
745 | |
746 | /* Unless the language specifies otherwise, let vector types alias | |
747 | their components. This avoids some nasty type punning issues in | |
748 | normal usage. And indeed lets vectors be treated more like an | |
749 | array slice. */ | |
750 | else if (TREE_CODE (t) == VECTOR_TYPE) | |
751 | set = get_alias_set (TREE_TYPE (t)); | |
752 | ||
4653cae5 RG |
753 | /* Unless the language specifies otherwise, treat array types the |
754 | same as their components. This avoids the asymmetry we get | |
755 | through recording the components. Consider accessing a | |
756 | character(kind=1) through a reference to a character(kind=1)[1:1]. | |
757 | Or consider if we want to assign integer(kind=4)[0:D.1387] and | |
758 | integer(kind=4)[4] the same alias set or not. | |
759 | Just be pragmatic here and make sure the array and its element | |
760 | type get the same alias set assigned. */ | |
7be7d292 | 761 | else if (TREE_CODE (t) == ARRAY_TYPE && !TYPE_NONALIASED_COMPONENT (t)) |
4653cae5 RG |
762 | set = get_alias_set (TREE_TYPE (t)); |
763 | ||
0ceb0201 RG |
764 | /* From the former common C and C++ langhook implementation: |
765 | ||
766 | Unfortunately, there is no canonical form of a pointer type. | |
767 | In particular, if we have `typedef int I', then `int *', and | |
768 | `I *' are different types. So, we have to pick a canonical | |
769 | representative. We do this below. | |
770 | ||
771 | Technically, this approach is actually more conservative that | |
772 | it needs to be. In particular, `const int *' and `int *' | |
773 | should be in different alias sets, according to the C and C++ | |
774 | standard, since their types are not the same, and so, | |
775 | technically, an `int **' and `const int **' cannot point at | |
776 | the same thing. | |
777 | ||
778 | But, the standard is wrong. In particular, this code is | |
779 | legal C++: | |
780 | ||
781 | int *ip; | |
782 | int **ipp = &ip; | |
783 | const int* const* cipp = ipp; | |
784 | And, it doesn't make sense for that to be legal unless you | |
785 | can dereference IPP and CIPP. So, we ignore cv-qualifiers on | |
786 | the pointed-to types. This issue has been reported to the | |
787 | C++ committee. | |
788 | ||
789 | In addition to the above canonicalization issue, with LTO | |
790 | we should also canonicalize `T (*)[]' to `T *' avoiding | |
791 | alias issues with pointer-to element types and pointer-to | |
792 | array types. | |
793 | ||
794 | Likewise we need to deal with the situation of incomplete | |
795 | pointed-to types and make `*(struct X **)&a' and | |
796 | `*(struct X {} **)&a' alias. Otherwise we will have to | |
797 | guarantee that all pointer-to incomplete type variants | |
798 | will be replaced by pointer-to complete type variants if | |
799 | they are available. | |
800 | ||
801 | With LTO the convenient situation of using `void *' to | |
802 | access and store any pointer type will also become | |
803 | more apparent (and `void *' is just another pointer-to | |
804 | incomplete type). Assigning alias-set zero to `void *' | |
805 | and all pointer-to incomplete types is a not appealing | |
806 | solution. Assigning an effective alias-set zero only | |
807 | affecting pointers might be - by recording proper subset | |
808 | relationships of all pointer alias-sets. | |
809 | ||
810 | Pointer-to function types are another grey area which | |
811 | needs caution. Globbing them all into one alias-set | |
812 | or the above effective zero set would work. | |
813 | ||
814 | For now just assign the same alias-set to all pointers. | |
815 | That's simple and avoids all the above problems. */ | |
816 | else if (POINTER_TYPE_P (t) | |
817 | && t != ptr_type_node) | |
818 | return get_alias_set (ptr_type_node); | |
819 | ||
7be7d292 | 820 | /* Otherwise make a new alias set for this type. */ |
3bdf5ad1 | 821 | else |
3bdf5ad1 RK |
822 | set = new_alias_set (); |
823 | ||
824 | TYPE_ALIAS_SET (t) = set; | |
2bf105ab | 825 | |
7be7d292 EB |
826 | /* If this is an aggregate type or a complex type, we must record any |
827 | component aliasing information. */ | |
1d79fd2c | 828 | if (AGGREGATE_TYPE_P (t) || TREE_CODE (t) == COMPLEX_TYPE) |
2bf105ab RK |
829 | record_component_aliases (t); |
830 | ||
3bdf5ad1 RK |
831 | return set; |
832 | } | |
833 | ||
834 | /* Return a brand-new alias set. */ | |
835 | ||
4862826d | 836 | alias_set_type |
4682ae04 | 837 | new_alias_set (void) |
3bdf5ad1 | 838 | { |
3bdf5ad1 | 839 | if (flag_strict_aliasing) |
9ddb66ca | 840 | { |
1a5640b4 KH |
841 | if (alias_sets == 0) |
842 | VEC_safe_push (alias_set_entry, gc, alias_sets, 0); | |
843 | VEC_safe_push (alias_set_entry, gc, alias_sets, 0); | |
844 | return VEC_length (alias_set_entry, alias_sets) - 1; | |
9ddb66ca | 845 | } |
3bdf5ad1 RK |
846 | else |
847 | return 0; | |
848 | } | |
3932261a | 849 | |
01d28c3f JM |
850 | /* Indicate that things in SUBSET can alias things in SUPERSET, but that |
851 | not everything that aliases SUPERSET also aliases SUBSET. For example, | |
852 | in C, a store to an `int' can alias a load of a structure containing an | |
853 | `int', and vice versa. But it can't alias a load of a 'double' member | |
854 | of the same structure. Here, the structure would be the SUPERSET and | |
855 | `int' the SUBSET. This relationship is also described in the comment at | |
856 | the beginning of this file. | |
857 | ||
858 | This function should be called only once per SUPERSET/SUBSET pair. | |
3932261a MM |
859 | |
860 | It is illegal for SUPERSET to be zero; everything is implicitly a | |
861 | subset of alias set zero. */ | |
862 | ||
794511d2 | 863 | void |
4862826d | 864 | record_alias_subset (alias_set_type superset, alias_set_type subset) |
3932261a MM |
865 | { |
866 | alias_set_entry superset_entry; | |
867 | alias_set_entry subset_entry; | |
868 | ||
f47e9b4e RK |
869 | /* It is possible in complex type situations for both sets to be the same, |
870 | in which case we can ignore this operation. */ | |
871 | if (superset == subset) | |
872 | return; | |
873 | ||
298e6adc | 874 | gcc_assert (superset); |
3932261a MM |
875 | |
876 | superset_entry = get_alias_set_entry (superset); | |
ca7fd9cd | 877 | if (superset_entry == 0) |
3932261a MM |
878 | { |
879 | /* Create an entry for the SUPERSET, so that we have a place to | |
880 | attach the SUBSET. */ | |
a9429e29 | 881 | superset_entry = ggc_alloc_cleared_alias_set_entry_d (); |
3932261a | 882 | superset_entry->alias_set = superset; |
ca7fd9cd | 883 | superset_entry->children |
a9429e29 LB |
884 | = splay_tree_new_ggc (splay_tree_compare_ints, |
885 | ggc_alloc_splay_tree_scalar_scalar_splay_tree_s, | |
886 | ggc_alloc_splay_tree_scalar_scalar_splay_tree_node_s); | |
570eb5c8 | 887 | superset_entry->has_zero_child = 0; |
1a5640b4 | 888 | VEC_replace (alias_set_entry, alias_sets, superset, superset_entry); |
3932261a MM |
889 | } |
890 | ||
2bf105ab RK |
891 | if (subset == 0) |
892 | superset_entry->has_zero_child = 1; | |
893 | else | |
894 | { | |
895 | subset_entry = get_alias_set_entry (subset); | |
896 | /* If there is an entry for the subset, enter all of its children | |
897 | (if they are not already present) as children of the SUPERSET. */ | |
ca7fd9cd | 898 | if (subset_entry) |
2bf105ab RK |
899 | { |
900 | if (subset_entry->has_zero_child) | |
901 | superset_entry->has_zero_child = 1; | |
d4b60170 | 902 | |
2bf105ab RK |
903 | splay_tree_foreach (subset_entry->children, insert_subset_children, |
904 | superset_entry->children); | |
905 | } | |
3932261a | 906 | |
2bf105ab | 907 | /* Enter the SUBSET itself as a child of the SUPERSET. */ |
ca7fd9cd | 908 | splay_tree_insert (superset_entry->children, |
2bf105ab RK |
909 | (splay_tree_key) subset, 0); |
910 | } | |
3932261a MM |
911 | } |
912 | ||
a0c33338 RK |
913 | /* Record that component types of TYPE, if any, are part of that type for |
914 | aliasing purposes. For record types, we only record component types | |
b5487346 EB |
915 | for fields that are not marked non-addressable. For array types, we |
916 | only record the component type if it is not marked non-aliased. */ | |
a0c33338 RK |
917 | |
918 | void | |
4682ae04 | 919 | record_component_aliases (tree type) |
a0c33338 | 920 | { |
4862826d | 921 | alias_set_type superset = get_alias_set (type); |
a0c33338 RK |
922 | tree field; |
923 | ||
924 | if (superset == 0) | |
925 | return; | |
926 | ||
927 | switch (TREE_CODE (type)) | |
928 | { | |
a0c33338 RK |
929 | case RECORD_TYPE: |
930 | case UNION_TYPE: | |
931 | case QUAL_UNION_TYPE: | |
6614fd40 | 932 | /* Recursively record aliases for the base classes, if there are any. */ |
fa743e8c | 933 | if (TYPE_BINFO (type)) |
ca7fd9cd KH |
934 | { |
935 | int i; | |
fa743e8c | 936 | tree binfo, base_binfo; |
c22cacf3 | 937 | |
fa743e8c NS |
938 | for (binfo = TYPE_BINFO (type), i = 0; |
939 | BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) | |
940 | record_alias_subset (superset, | |
941 | get_alias_set (BINFO_TYPE (base_binfo))); | |
ca7fd9cd | 942 | } |
910ad8de | 943 | for (field = TYPE_FIELDS (type); field != 0; field = DECL_CHAIN (field)) |
b5487346 | 944 | if (TREE_CODE (field) == FIELD_DECL && !DECL_NONADDRESSABLE_P (field)) |
2bf105ab | 945 | record_alias_subset (superset, get_alias_set (TREE_TYPE (field))); |
a0c33338 RK |
946 | break; |
947 | ||
1d79fd2c JW |
948 | case COMPLEX_TYPE: |
949 | record_alias_subset (superset, get_alias_set (TREE_TYPE (type))); | |
950 | break; | |
951 | ||
4653cae5 RG |
952 | /* VECTOR_TYPE and ARRAY_TYPE share the alias set with their |
953 | element type. */ | |
954 | ||
a0c33338 RK |
955 | default: |
956 | break; | |
957 | } | |
958 | } | |
959 | ||
3bdf5ad1 RK |
960 | /* Allocate an alias set for use in storing and reading from the varargs |
961 | spill area. */ | |
962 | ||
4862826d | 963 | static GTY(()) alias_set_type varargs_set = -1; |
f103e34d | 964 | |
4862826d | 965 | alias_set_type |
4682ae04 | 966 | get_varargs_alias_set (void) |
3bdf5ad1 | 967 | { |
cd3ce9b4 JM |
968 | #if 1 |
969 | /* We now lower VA_ARG_EXPR, and there's currently no way to attach the | |
970 | varargs alias set to an INDIRECT_REF (FIXME!), so we can't | |
971 | consistently use the varargs alias set for loads from the varargs | |
972 | area. So don't use it anywhere. */ | |
973 | return 0; | |
974 | #else | |
f103e34d GK |
975 | if (varargs_set == -1) |
976 | varargs_set = new_alias_set (); | |
3bdf5ad1 | 977 | |
f103e34d | 978 | return varargs_set; |
cd3ce9b4 | 979 | #endif |
3bdf5ad1 RK |
980 | } |
981 | ||
982 | /* Likewise, but used for the fixed portions of the frame, e.g., register | |
983 | save areas. */ | |
984 | ||
4862826d | 985 | static GTY(()) alias_set_type frame_set = -1; |
f103e34d | 986 | |
4862826d | 987 | alias_set_type |
4682ae04 | 988 | get_frame_alias_set (void) |
3bdf5ad1 | 989 | { |
f103e34d GK |
990 | if (frame_set == -1) |
991 | frame_set = new_alias_set (); | |
3bdf5ad1 | 992 | |
f103e34d | 993 | return frame_set; |
3bdf5ad1 RK |
994 | } |
995 | ||
2a2c8203 JC |
996 | /* Inside SRC, the source of a SET, find a base address. */ |
997 | ||
9ae8ffe7 | 998 | static rtx |
4682ae04 | 999 | find_base_value (rtx src) |
9ae8ffe7 | 1000 | { |
713f41f9 | 1001 | unsigned int regno; |
0aacc8ed | 1002 | |
53451050 RS |
1003 | #if defined (FIND_BASE_TERM) |
1004 | /* Try machine-dependent ways to find the base term. */ | |
1005 | src = FIND_BASE_TERM (src); | |
1006 | #endif | |
1007 | ||
9ae8ffe7 JL |
1008 | switch (GET_CODE (src)) |
1009 | { | |
1010 | case SYMBOL_REF: | |
1011 | case LABEL_REF: | |
1012 | return src; | |
1013 | ||
1014 | case REG: | |
fb6754f0 | 1015 | regno = REGNO (src); |
d4b60170 | 1016 | /* At the start of a function, argument registers have known base |
2a2c8203 JC |
1017 | values which may be lost later. Returning an ADDRESS |
1018 | expression here allows optimization based on argument values | |
1019 | even when the argument registers are used for other purposes. */ | |
713f41f9 BS |
1020 | if (regno < FIRST_PSEUDO_REGISTER && copying_arguments) |
1021 | return new_reg_base_value[regno]; | |
73774bc7 | 1022 | |
eaf407a5 | 1023 | /* If a pseudo has a known base value, return it. Do not do this |
9b462c42 RH |
1024 | for non-fixed hard regs since it can result in a circular |
1025 | dependency chain for registers which have values at function entry. | |
eaf407a5 JL |
1026 | |
1027 | The test above is not sufficient because the scheduler may move | |
1028 | a copy out of an arg reg past the NOTE_INSN_FUNCTION_BEGIN. */ | |
9b462c42 | 1029 | if ((regno >= FIRST_PSEUDO_REGISTER || fixed_regs[regno]) |
08c79682 | 1030 | && regno < VEC_length (rtx, reg_base_value)) |
83bbd9b6 RH |
1031 | { |
1032 | /* If we're inside init_alias_analysis, use new_reg_base_value | |
1033 | to reduce the number of relaxation iterations. */ | |
1afdf91c | 1034 | if (new_reg_base_value && new_reg_base_value[regno] |
6fb5fa3c | 1035 | && DF_REG_DEF_COUNT (regno) == 1) |
83bbd9b6 RH |
1036 | return new_reg_base_value[regno]; |
1037 | ||
08c79682 KH |
1038 | if (VEC_index (rtx, reg_base_value, regno)) |
1039 | return VEC_index (rtx, reg_base_value, regno); | |
83bbd9b6 | 1040 | } |
73774bc7 | 1041 | |
e3f049a8 | 1042 | return 0; |
9ae8ffe7 JL |
1043 | |
1044 | case MEM: | |
1045 | /* Check for an argument passed in memory. Only record in the | |
1046 | copying-arguments block; it is too hard to track changes | |
1047 | otherwise. */ | |
1048 | if (copying_arguments | |
1049 | && (XEXP (src, 0) == arg_pointer_rtx | |
1050 | || (GET_CODE (XEXP (src, 0)) == PLUS | |
1051 | && XEXP (XEXP (src, 0), 0) == arg_pointer_rtx))) | |
38a448ca | 1052 | return gen_rtx_ADDRESS (VOIDmode, src); |
9ae8ffe7 JL |
1053 | return 0; |
1054 | ||
1055 | case CONST: | |
1056 | src = XEXP (src, 0); | |
1057 | if (GET_CODE (src) != PLUS && GET_CODE (src) != MINUS) | |
1058 | break; | |
d4b60170 | 1059 | |
ec5c56db | 1060 | /* ... fall through ... */ |
2a2c8203 | 1061 | |
9ae8ffe7 JL |
1062 | case PLUS: |
1063 | case MINUS: | |
2a2c8203 | 1064 | { |
ec907dd8 JL |
1065 | rtx temp, src_0 = XEXP (src, 0), src_1 = XEXP (src, 1); |
1066 | ||
0134bf2d DE |
1067 | /* If either operand is a REG that is a known pointer, then it |
1068 | is the base. */ | |
1069 | if (REG_P (src_0) && REG_POINTER (src_0)) | |
1070 | return find_base_value (src_0); | |
1071 | if (REG_P (src_1) && REG_POINTER (src_1)) | |
1072 | return find_base_value (src_1); | |
1073 | ||
ec907dd8 JL |
1074 | /* If either operand is a REG, then see if we already have |
1075 | a known value for it. */ | |
0134bf2d | 1076 | if (REG_P (src_0)) |
ec907dd8 JL |
1077 | { |
1078 | temp = find_base_value (src_0); | |
d4b60170 | 1079 | if (temp != 0) |
ec907dd8 JL |
1080 | src_0 = temp; |
1081 | } | |
1082 | ||
0134bf2d | 1083 | if (REG_P (src_1)) |
ec907dd8 JL |
1084 | { |
1085 | temp = find_base_value (src_1); | |
d4b60170 | 1086 | if (temp!= 0) |
ec907dd8 JL |
1087 | src_1 = temp; |
1088 | } | |
2a2c8203 | 1089 | |
0134bf2d DE |
1090 | /* If either base is named object or a special address |
1091 | (like an argument or stack reference), then use it for the | |
1092 | base term. */ | |
1093 | if (src_0 != 0 | |
1094 | && (GET_CODE (src_0) == SYMBOL_REF | |
1095 | || GET_CODE (src_0) == LABEL_REF | |
1096 | || (GET_CODE (src_0) == ADDRESS | |
1097 | && GET_MODE (src_0) != VOIDmode))) | |
1098 | return src_0; | |
1099 | ||
1100 | if (src_1 != 0 | |
1101 | && (GET_CODE (src_1) == SYMBOL_REF | |
1102 | || GET_CODE (src_1) == LABEL_REF | |
1103 | || (GET_CODE (src_1) == ADDRESS | |
1104 | && GET_MODE (src_1) != VOIDmode))) | |
1105 | return src_1; | |
1106 | ||
d4b60170 | 1107 | /* Guess which operand is the base address: |
ec907dd8 JL |
1108 | If either operand is a symbol, then it is the base. If |
1109 | either operand is a CONST_INT, then the other is the base. */ | |
481683e1 | 1110 | if (CONST_INT_P (src_1) || CONSTANT_P (src_0)) |
2a2c8203 | 1111 | return find_base_value (src_0); |
481683e1 | 1112 | else if (CONST_INT_P (src_0) || CONSTANT_P (src_1)) |
ec907dd8 JL |
1113 | return find_base_value (src_1); |
1114 | ||
9ae8ffe7 | 1115 | return 0; |
2a2c8203 JC |
1116 | } |
1117 | ||
1118 | case LO_SUM: | |
1119 | /* The standard form is (lo_sum reg sym) so look only at the | |
1120 | second operand. */ | |
1121 | return find_base_value (XEXP (src, 1)); | |
9ae8ffe7 JL |
1122 | |
1123 | case AND: | |
1124 | /* If the second operand is constant set the base | |
ec5c56db | 1125 | address to the first operand. */ |
481683e1 | 1126 | if (CONST_INT_P (XEXP (src, 1)) && INTVAL (XEXP (src, 1)) != 0) |
2a2c8203 | 1127 | return find_base_value (XEXP (src, 0)); |
9ae8ffe7 JL |
1128 | return 0; |
1129 | ||
61f0131c | 1130 | case TRUNCATE: |
d4ebfa65 BE |
1131 | /* As we do not know which address space the pointer is refering to, we can |
1132 | handle this only if the target does not support different pointer or | |
1133 | address modes depending on the address space. */ | |
1134 | if (!target_default_pointer_address_modes_p ()) | |
1135 | break; | |
61f0131c R |
1136 | if (GET_MODE_SIZE (GET_MODE (src)) < GET_MODE_SIZE (Pmode)) |
1137 | break; | |
1138 | /* Fall through. */ | |
9ae8ffe7 | 1139 | case HIGH: |
d288e53d DE |
1140 | case PRE_INC: |
1141 | case PRE_DEC: | |
1142 | case POST_INC: | |
1143 | case POST_DEC: | |
1144 | case PRE_MODIFY: | |
1145 | case POST_MODIFY: | |
2a2c8203 | 1146 | return find_base_value (XEXP (src, 0)); |
1d300e19 | 1147 | |
0aacc8ed RK |
1148 | case ZERO_EXTEND: |
1149 | case SIGN_EXTEND: /* used for NT/Alpha pointers */ | |
d4ebfa65 BE |
1150 | /* As we do not know which address space the pointer is refering to, we can |
1151 | handle this only if the target does not support different pointer or | |
1152 | address modes depending on the address space. */ | |
1153 | if (!target_default_pointer_address_modes_p ()) | |
1154 | break; | |
1155 | ||
0aacc8ed RK |
1156 | { |
1157 | rtx temp = find_base_value (XEXP (src, 0)); | |
1158 | ||
5ae6cd0d | 1159 | if (temp != 0 && CONSTANT_P (temp)) |
0aacc8ed | 1160 | temp = convert_memory_address (Pmode, temp); |
0aacc8ed RK |
1161 | |
1162 | return temp; | |
1163 | } | |
1164 | ||
1d300e19 KG |
1165 | default: |
1166 | break; | |
9ae8ffe7 JL |
1167 | } |
1168 | ||
1169 | return 0; | |
1170 | } | |
1171 | ||
1172 | /* Called from init_alias_analysis indirectly through note_stores. */ | |
1173 | ||
d4b60170 | 1174 | /* While scanning insns to find base values, reg_seen[N] is nonzero if |
9ae8ffe7 JL |
1175 | register N has been set in this function. */ |
1176 | static char *reg_seen; | |
1177 | ||
13309a5f JC |
1178 | /* Addresses which are known not to alias anything else are identified |
1179 | by a unique integer. */ | |
ec907dd8 JL |
1180 | static int unique_id; |
1181 | ||
2a2c8203 | 1182 | static void |
7bc980e1 | 1183 | record_set (rtx dest, const_rtx set, void *data ATTRIBUTE_UNUSED) |
9ae8ffe7 | 1184 | { |
b3694847 | 1185 | unsigned regno; |
9ae8ffe7 | 1186 | rtx src; |
c28b4e40 | 1187 | int n; |
9ae8ffe7 | 1188 | |
f8cfc6aa | 1189 | if (!REG_P (dest)) |
9ae8ffe7 JL |
1190 | return; |
1191 | ||
fb6754f0 | 1192 | regno = REGNO (dest); |
9ae8ffe7 | 1193 | |
7a40b8b1 | 1194 | gcc_checking_assert (regno < VEC_length (rtx, reg_base_value)); |
ac606739 | 1195 | |
c28b4e40 JW |
1196 | /* If this spans multiple hard registers, then we must indicate that every |
1197 | register has an unusable value. */ | |
1198 | if (regno < FIRST_PSEUDO_REGISTER) | |
66fd46b6 | 1199 | n = hard_regno_nregs[regno][GET_MODE (dest)]; |
c28b4e40 JW |
1200 | else |
1201 | n = 1; | |
1202 | if (n != 1) | |
1203 | { | |
1204 | while (--n >= 0) | |
1205 | { | |
1206 | reg_seen[regno + n] = 1; | |
1207 | new_reg_base_value[regno + n] = 0; | |
1208 | } | |
1209 | return; | |
1210 | } | |
1211 | ||
9ae8ffe7 JL |
1212 | if (set) |
1213 | { | |
1214 | /* A CLOBBER wipes out any old value but does not prevent a previously | |
1215 | unset register from acquiring a base address (i.e. reg_seen is not | |
1216 | set). */ | |
1217 | if (GET_CODE (set) == CLOBBER) | |
1218 | { | |
ec907dd8 | 1219 | new_reg_base_value[regno] = 0; |
9ae8ffe7 JL |
1220 | return; |
1221 | } | |
1222 | src = SET_SRC (set); | |
1223 | } | |
1224 | else | |
1225 | { | |
9ae8ffe7 JL |
1226 | if (reg_seen[regno]) |
1227 | { | |
ec907dd8 | 1228 | new_reg_base_value[regno] = 0; |
9ae8ffe7 JL |
1229 | return; |
1230 | } | |
1231 | reg_seen[regno] = 1; | |
38a448ca RH |
1232 | new_reg_base_value[regno] = gen_rtx_ADDRESS (Pmode, |
1233 | GEN_INT (unique_id++)); | |
9ae8ffe7 JL |
1234 | return; |
1235 | } | |
1236 | ||
5da6f168 RS |
1237 | /* If this is not the first set of REGNO, see whether the new value |
1238 | is related to the old one. There are two cases of interest: | |
1239 | ||
1240 | (1) The register might be assigned an entirely new value | |
1241 | that has the same base term as the original set. | |
1242 | ||
1243 | (2) The set might be a simple self-modification that | |
1244 | cannot change REGNO's base value. | |
1245 | ||
1246 | If neither case holds, reject the original base value as invalid. | |
1247 | Note that the following situation is not detected: | |
1248 | ||
c22cacf3 | 1249 | extern int x, y; int *p = &x; p += (&y-&x); |
5da6f168 | 1250 | |
9ae8ffe7 JL |
1251 | ANSI C does not allow computing the difference of addresses |
1252 | of distinct top level objects. */ | |
5da6f168 RS |
1253 | if (new_reg_base_value[regno] != 0 |
1254 | && find_base_value (src) != new_reg_base_value[regno]) | |
9ae8ffe7 JL |
1255 | switch (GET_CODE (src)) |
1256 | { | |
2a2c8203 | 1257 | case LO_SUM: |
9ae8ffe7 JL |
1258 | case MINUS: |
1259 | if (XEXP (src, 0) != dest && XEXP (src, 1) != dest) | |
ec907dd8 | 1260 | new_reg_base_value[regno] = 0; |
9ae8ffe7 | 1261 | break; |
61f0131c R |
1262 | case PLUS: |
1263 | /* If the value we add in the PLUS is also a valid base value, | |
1264 | this might be the actual base value, and the original value | |
1265 | an index. */ | |
1266 | { | |
1267 | rtx other = NULL_RTX; | |
1268 | ||
1269 | if (XEXP (src, 0) == dest) | |
1270 | other = XEXP (src, 1); | |
1271 | else if (XEXP (src, 1) == dest) | |
1272 | other = XEXP (src, 0); | |
1273 | ||
1274 | if (! other || find_base_value (other)) | |
1275 | new_reg_base_value[regno] = 0; | |
1276 | break; | |
1277 | } | |
9ae8ffe7 | 1278 | case AND: |
481683e1 | 1279 | if (XEXP (src, 0) != dest || !CONST_INT_P (XEXP (src, 1))) |
ec907dd8 | 1280 | new_reg_base_value[regno] = 0; |
9ae8ffe7 | 1281 | break; |
9ae8ffe7 | 1282 | default: |
ec907dd8 | 1283 | new_reg_base_value[regno] = 0; |
9ae8ffe7 JL |
1284 | break; |
1285 | } | |
1286 | /* If this is the first set of a register, record the value. */ | |
1287 | else if ((regno >= FIRST_PSEUDO_REGISTER || ! fixed_regs[regno]) | |
ec907dd8 JL |
1288 | && ! reg_seen[regno] && new_reg_base_value[regno] == 0) |
1289 | new_reg_base_value[regno] = find_base_value (src); | |
9ae8ffe7 JL |
1290 | |
1291 | reg_seen[regno] = 1; | |
1292 | } | |
1293 | ||
bb1acb3e RH |
1294 | /* If a value is known for REGNO, return it. */ |
1295 | ||
c22cacf3 | 1296 | rtx |
bb1acb3e RH |
1297 | get_reg_known_value (unsigned int regno) |
1298 | { | |
1299 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1300 | { | |
1301 | regno -= FIRST_PSEUDO_REGISTER; | |
1302 | if (regno < reg_known_value_size) | |
1303 | return reg_known_value[regno]; | |
1304 | } | |
1305 | return NULL; | |
43fe47ca JW |
1306 | } |
1307 | ||
bb1acb3e RH |
1308 | /* Set it. */ |
1309 | ||
1310 | static void | |
1311 | set_reg_known_value (unsigned int regno, rtx val) | |
1312 | { | |
1313 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1314 | { | |
1315 | regno -= FIRST_PSEUDO_REGISTER; | |
1316 | if (regno < reg_known_value_size) | |
1317 | reg_known_value[regno] = val; | |
1318 | } | |
1319 | } | |
1320 | ||
1321 | /* Similarly for reg_known_equiv_p. */ | |
1322 | ||
1323 | bool | |
1324 | get_reg_known_equiv_p (unsigned int regno) | |
1325 | { | |
1326 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1327 | { | |
1328 | regno -= FIRST_PSEUDO_REGISTER; | |
1329 | if (regno < reg_known_value_size) | |
1330 | return reg_known_equiv_p[regno]; | |
1331 | } | |
1332 | return false; | |
1333 | } | |
1334 | ||
1335 | static void | |
1336 | set_reg_known_equiv_p (unsigned int regno, bool val) | |
1337 | { | |
1338 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1339 | { | |
1340 | regno -= FIRST_PSEUDO_REGISTER; | |
1341 | if (regno < reg_known_value_size) | |
1342 | reg_known_equiv_p[regno] = val; | |
1343 | } | |
1344 | } | |
1345 | ||
1346 | ||
db048faf MM |
1347 | /* Returns a canonical version of X, from the point of view alias |
1348 | analysis. (For example, if X is a MEM whose address is a register, | |
1349 | and the register has a known value (say a SYMBOL_REF), then a MEM | |
1350 | whose address is the SYMBOL_REF is returned.) */ | |
1351 | ||
1352 | rtx | |
4682ae04 | 1353 | canon_rtx (rtx x) |
9ae8ffe7 JL |
1354 | { |
1355 | /* Recursively look for equivalences. */ | |
f8cfc6aa | 1356 | if (REG_P (x) && REGNO (x) >= FIRST_PSEUDO_REGISTER) |
bb1acb3e RH |
1357 | { |
1358 | rtx t = get_reg_known_value (REGNO (x)); | |
1359 | if (t == x) | |
1360 | return x; | |
1361 | if (t) | |
1362 | return canon_rtx (t); | |
1363 | } | |
1364 | ||
1365 | if (GET_CODE (x) == PLUS) | |
9ae8ffe7 JL |
1366 | { |
1367 | rtx x0 = canon_rtx (XEXP (x, 0)); | |
1368 | rtx x1 = canon_rtx (XEXP (x, 1)); | |
1369 | ||
1370 | if (x0 != XEXP (x, 0) || x1 != XEXP (x, 1)) | |
1371 | { | |
481683e1 | 1372 | if (CONST_INT_P (x0)) |
ed8908e7 | 1373 | return plus_constant (x1, INTVAL (x0)); |
481683e1 | 1374 | else if (CONST_INT_P (x1)) |
ed8908e7 | 1375 | return plus_constant (x0, INTVAL (x1)); |
38a448ca | 1376 | return gen_rtx_PLUS (GET_MODE (x), x0, x1); |
9ae8ffe7 JL |
1377 | } |
1378 | } | |
d4b60170 | 1379 | |
9ae8ffe7 JL |
1380 | /* This gives us much better alias analysis when called from |
1381 | the loop optimizer. Note we want to leave the original | |
1382 | MEM alone, but need to return the canonicalized MEM with | |
1383 | all the flags with their original values. */ | |
3c0cb5de | 1384 | else if (MEM_P (x)) |
f1ec5147 | 1385 | x = replace_equiv_address_nv (x, canon_rtx (XEXP (x, 0))); |
d4b60170 | 1386 | |
9ae8ffe7 JL |
1387 | return x; |
1388 | } | |
1389 | ||
1390 | /* Return 1 if X and Y are identical-looking rtx's. | |
45183e03 | 1391 | Expect that X and Y has been already canonicalized. |
9ae8ffe7 JL |
1392 | |
1393 | We use the data in reg_known_value above to see if two registers with | |
1394 | different numbers are, in fact, equivalent. */ | |
1395 | ||
1396 | static int | |
ed7a4b4b | 1397 | rtx_equal_for_memref_p (const_rtx x, const_rtx y) |
9ae8ffe7 | 1398 | { |
b3694847 SS |
1399 | int i; |
1400 | int j; | |
1401 | enum rtx_code code; | |
1402 | const char *fmt; | |
9ae8ffe7 JL |
1403 | |
1404 | if (x == 0 && y == 0) | |
1405 | return 1; | |
1406 | if (x == 0 || y == 0) | |
1407 | return 0; | |
d4b60170 | 1408 | |
9ae8ffe7 JL |
1409 | if (x == y) |
1410 | return 1; | |
1411 | ||
1412 | code = GET_CODE (x); | |
1413 | /* Rtx's of different codes cannot be equal. */ | |
1414 | if (code != GET_CODE (y)) | |
1415 | return 0; | |
1416 | ||
1417 | /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. | |
1418 | (REG:SI x) and (REG:HI x) are NOT equivalent. */ | |
1419 | ||
1420 | if (GET_MODE (x) != GET_MODE (y)) | |
1421 | return 0; | |
1422 | ||
db048faf MM |
1423 | /* Some RTL can be compared without a recursive examination. */ |
1424 | switch (code) | |
1425 | { | |
1426 | case REG: | |
1427 | return REGNO (x) == REGNO (y); | |
1428 | ||
1429 | case LABEL_REF: | |
1430 | return XEXP (x, 0) == XEXP (y, 0); | |
ca7fd9cd | 1431 | |
db048faf MM |
1432 | case SYMBOL_REF: |
1433 | return XSTR (x, 0) == XSTR (y, 0); | |
1434 | ||
40e02b4a | 1435 | case VALUE: |
db048faf MM |
1436 | case CONST_INT: |
1437 | case CONST_DOUBLE: | |
091a3ac7 | 1438 | case CONST_FIXED: |
db048faf MM |
1439 | /* There's no need to compare the contents of CONST_DOUBLEs or |
1440 | CONST_INTs because pointer equality is a good enough | |
1441 | comparison for these nodes. */ | |
1442 | return 0; | |
1443 | ||
db048faf MM |
1444 | default: |
1445 | break; | |
1446 | } | |
9ae8ffe7 | 1447 | |
45183e03 JH |
1448 | /* canon_rtx knows how to handle plus. No need to canonicalize. */ |
1449 | if (code == PLUS) | |
9ae8ffe7 JL |
1450 | return ((rtx_equal_for_memref_p (XEXP (x, 0), XEXP (y, 0)) |
1451 | && rtx_equal_for_memref_p (XEXP (x, 1), XEXP (y, 1))) | |
1452 | || (rtx_equal_for_memref_p (XEXP (x, 0), XEXP (y, 1)) | |
1453 | && rtx_equal_for_memref_p (XEXP (x, 1), XEXP (y, 0)))); | |
45183e03 JH |
1454 | /* For commutative operations, the RTX match if the operand match in any |
1455 | order. Also handle the simple binary and unary cases without a loop. */ | |
ec8e098d | 1456 | if (COMMUTATIVE_P (x)) |
45183e03 JH |
1457 | { |
1458 | rtx xop0 = canon_rtx (XEXP (x, 0)); | |
1459 | rtx yop0 = canon_rtx (XEXP (y, 0)); | |
1460 | rtx yop1 = canon_rtx (XEXP (y, 1)); | |
1461 | ||
1462 | return ((rtx_equal_for_memref_p (xop0, yop0) | |
1463 | && rtx_equal_for_memref_p (canon_rtx (XEXP (x, 1)), yop1)) | |
1464 | || (rtx_equal_for_memref_p (xop0, yop1) | |
1465 | && rtx_equal_for_memref_p (canon_rtx (XEXP (x, 1)), yop0))); | |
1466 | } | |
ec8e098d | 1467 | else if (NON_COMMUTATIVE_P (x)) |
45183e03 JH |
1468 | { |
1469 | return (rtx_equal_for_memref_p (canon_rtx (XEXP (x, 0)), | |
4682ae04 | 1470 | canon_rtx (XEXP (y, 0))) |
45183e03 JH |
1471 | && rtx_equal_for_memref_p (canon_rtx (XEXP (x, 1)), |
1472 | canon_rtx (XEXP (y, 1)))); | |
1473 | } | |
ec8e098d | 1474 | else if (UNARY_P (x)) |
45183e03 | 1475 | return rtx_equal_for_memref_p (canon_rtx (XEXP (x, 0)), |
4682ae04 | 1476 | canon_rtx (XEXP (y, 0))); |
9ae8ffe7 JL |
1477 | |
1478 | /* Compare the elements. If any pair of corresponding elements | |
de12be17 JC |
1479 | fail to match, return 0 for the whole things. |
1480 | ||
1481 | Limit cases to types which actually appear in addresses. */ | |
9ae8ffe7 JL |
1482 | |
1483 | fmt = GET_RTX_FORMAT (code); | |
1484 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
1485 | { | |
1486 | switch (fmt[i]) | |
1487 | { | |
9ae8ffe7 JL |
1488 | case 'i': |
1489 | if (XINT (x, i) != XINT (y, i)) | |
1490 | return 0; | |
1491 | break; | |
1492 | ||
9ae8ffe7 JL |
1493 | case 'E': |
1494 | /* Two vectors must have the same length. */ | |
1495 | if (XVECLEN (x, i) != XVECLEN (y, i)) | |
1496 | return 0; | |
1497 | ||
1498 | /* And the corresponding elements must match. */ | |
1499 | for (j = 0; j < XVECLEN (x, i); j++) | |
45183e03 JH |
1500 | if (rtx_equal_for_memref_p (canon_rtx (XVECEXP (x, i, j)), |
1501 | canon_rtx (XVECEXP (y, i, j))) == 0) | |
9ae8ffe7 JL |
1502 | return 0; |
1503 | break; | |
1504 | ||
1505 | case 'e': | |
45183e03 JH |
1506 | if (rtx_equal_for_memref_p (canon_rtx (XEXP (x, i)), |
1507 | canon_rtx (XEXP (y, i))) == 0) | |
9ae8ffe7 JL |
1508 | return 0; |
1509 | break; | |
1510 | ||
3237ac18 AH |
1511 | /* This can happen for asm operands. */ |
1512 | case 's': | |
1513 | if (strcmp (XSTR (x, i), XSTR (y, i))) | |
1514 | return 0; | |
1515 | break; | |
1516 | ||
aee21ba9 JL |
1517 | /* This can happen for an asm which clobbers memory. */ |
1518 | case '0': | |
1519 | break; | |
1520 | ||
9ae8ffe7 JL |
1521 | /* It is believed that rtx's at this level will never |
1522 | contain anything but integers and other rtx's, | |
1523 | except for within LABEL_REFs and SYMBOL_REFs. */ | |
1524 | default: | |
298e6adc | 1525 | gcc_unreachable (); |
9ae8ffe7 JL |
1526 | } |
1527 | } | |
1528 | return 1; | |
1529 | } | |
1530 | ||
94f24ddc | 1531 | rtx |
4682ae04 | 1532 | find_base_term (rtx x) |
9ae8ffe7 | 1533 | { |
eab5c70a BS |
1534 | cselib_val *val; |
1535 | struct elt_loc_list *l; | |
1536 | ||
b949ea8b JW |
1537 | #if defined (FIND_BASE_TERM) |
1538 | /* Try machine-dependent ways to find the base term. */ | |
1539 | x = FIND_BASE_TERM (x); | |
1540 | #endif | |
1541 | ||
9ae8ffe7 JL |
1542 | switch (GET_CODE (x)) |
1543 | { | |
1544 | case REG: | |
1545 | return REG_BASE_VALUE (x); | |
1546 | ||
d288e53d | 1547 | case TRUNCATE: |
d4ebfa65 BE |
1548 | /* As we do not know which address space the pointer is refering to, we can |
1549 | handle this only if the target does not support different pointer or | |
1550 | address modes depending on the address space. */ | |
1551 | if (!target_default_pointer_address_modes_p ()) | |
1552 | return 0; | |
d288e53d | 1553 | if (GET_MODE_SIZE (GET_MODE (x)) < GET_MODE_SIZE (Pmode)) |
ca7fd9cd | 1554 | return 0; |
d288e53d | 1555 | /* Fall through. */ |
9ae8ffe7 | 1556 | case HIGH: |
6d849a2a JL |
1557 | case PRE_INC: |
1558 | case PRE_DEC: | |
1559 | case POST_INC: | |
1560 | case POST_DEC: | |
d288e53d DE |
1561 | case PRE_MODIFY: |
1562 | case POST_MODIFY: | |
6d849a2a JL |
1563 | return find_base_term (XEXP (x, 0)); |
1564 | ||
1abade85 RK |
1565 | case ZERO_EXTEND: |
1566 | case SIGN_EXTEND: /* Used for Alpha/NT pointers */ | |
d4ebfa65 BE |
1567 | /* As we do not know which address space the pointer is refering to, we can |
1568 | handle this only if the target does not support different pointer or | |
1569 | address modes depending on the address space. */ | |
1570 | if (!target_default_pointer_address_modes_p ()) | |
1571 | return 0; | |
1572 | ||
1abade85 RK |
1573 | { |
1574 | rtx temp = find_base_term (XEXP (x, 0)); | |
1575 | ||
5ae6cd0d | 1576 | if (temp != 0 && CONSTANT_P (temp)) |
1abade85 | 1577 | temp = convert_memory_address (Pmode, temp); |
1abade85 RK |
1578 | |
1579 | return temp; | |
1580 | } | |
1581 | ||
eab5c70a BS |
1582 | case VALUE: |
1583 | val = CSELIB_VAL_PTR (x); | |
40e02b4a JH |
1584 | if (!val) |
1585 | return 0; | |
eab5c70a BS |
1586 | for (l = val->locs; l; l = l->next) |
1587 | if ((x = find_base_term (l->loc)) != 0) | |
1588 | return x; | |
1589 | return 0; | |
1590 | ||
023f059b JJ |
1591 | case LO_SUM: |
1592 | /* The standard form is (lo_sum reg sym) so look only at the | |
1593 | second operand. */ | |
1594 | return find_base_term (XEXP (x, 1)); | |
1595 | ||
9ae8ffe7 JL |
1596 | case CONST: |
1597 | x = XEXP (x, 0); | |
1598 | if (GET_CODE (x) != PLUS && GET_CODE (x) != MINUS) | |
1599 | return 0; | |
938d968e | 1600 | /* Fall through. */ |
9ae8ffe7 JL |
1601 | case PLUS: |
1602 | case MINUS: | |
1603 | { | |
3c567fae JL |
1604 | rtx tmp1 = XEXP (x, 0); |
1605 | rtx tmp2 = XEXP (x, 1); | |
1606 | ||
f5143c46 | 1607 | /* This is a little bit tricky since we have to determine which of |
3c567fae JL |
1608 | the two operands represents the real base address. Otherwise this |
1609 | routine may return the index register instead of the base register. | |
1610 | ||
1611 | That may cause us to believe no aliasing was possible, when in | |
1612 | fact aliasing is possible. | |
1613 | ||
1614 | We use a few simple tests to guess the base register. Additional | |
1615 | tests can certainly be added. For example, if one of the operands | |
1616 | is a shift or multiply, then it must be the index register and the | |
1617 | other operand is the base register. */ | |
ca7fd9cd | 1618 | |
b949ea8b JW |
1619 | if (tmp1 == pic_offset_table_rtx && CONSTANT_P (tmp2)) |
1620 | return find_base_term (tmp2); | |
1621 | ||
3c567fae JL |
1622 | /* If either operand is known to be a pointer, then use it |
1623 | to determine the base term. */ | |
3502dc9c | 1624 | if (REG_P (tmp1) && REG_POINTER (tmp1)) |
7eba2d1f LM |
1625 | { |
1626 | rtx base = find_base_term (tmp1); | |
1627 | if (base) | |
1628 | return base; | |
1629 | } | |
3c567fae | 1630 | |
3502dc9c | 1631 | if (REG_P (tmp2) && REG_POINTER (tmp2)) |
7eba2d1f LM |
1632 | { |
1633 | rtx base = find_base_term (tmp2); | |
1634 | if (base) | |
1635 | return base; | |
1636 | } | |
3c567fae JL |
1637 | |
1638 | /* Neither operand was known to be a pointer. Go ahead and find the | |
1639 | base term for both operands. */ | |
1640 | tmp1 = find_base_term (tmp1); | |
1641 | tmp2 = find_base_term (tmp2); | |
1642 | ||
1643 | /* If either base term is named object or a special address | |
1644 | (like an argument or stack reference), then use it for the | |
1645 | base term. */ | |
d4b60170 | 1646 | if (tmp1 != 0 |
3c567fae JL |
1647 | && (GET_CODE (tmp1) == SYMBOL_REF |
1648 | || GET_CODE (tmp1) == LABEL_REF | |
1649 | || (GET_CODE (tmp1) == ADDRESS | |
1650 | && GET_MODE (tmp1) != VOIDmode))) | |
1651 | return tmp1; | |
1652 | ||
d4b60170 | 1653 | if (tmp2 != 0 |
3c567fae JL |
1654 | && (GET_CODE (tmp2) == SYMBOL_REF |
1655 | || GET_CODE (tmp2) == LABEL_REF | |
1656 | || (GET_CODE (tmp2) == ADDRESS | |
1657 | && GET_MODE (tmp2) != VOIDmode))) | |
1658 | return tmp2; | |
1659 | ||
1660 | /* We could not determine which of the two operands was the | |
1661 | base register and which was the index. So we can determine | |
1662 | nothing from the base alias check. */ | |
1663 | return 0; | |
9ae8ffe7 JL |
1664 | } |
1665 | ||
1666 | case AND: | |
481683e1 | 1667 | if (CONST_INT_P (XEXP (x, 1)) && INTVAL (XEXP (x, 1)) != 0) |
d288e53d | 1668 | return find_base_term (XEXP (x, 0)); |
9ae8ffe7 JL |
1669 | return 0; |
1670 | ||
1671 | case SYMBOL_REF: | |
1672 | case LABEL_REF: | |
1673 | return x; | |
1674 | ||
1675 | default: | |
1676 | return 0; | |
1677 | } | |
1678 | } | |
1679 | ||
1680 | /* Return 0 if the addresses X and Y are known to point to different | |
1681 | objects, 1 if they might be pointers to the same object. */ | |
1682 | ||
1683 | static int | |
4682ae04 AJ |
1684 | base_alias_check (rtx x, rtx y, enum machine_mode x_mode, |
1685 | enum machine_mode y_mode) | |
9ae8ffe7 JL |
1686 | { |
1687 | rtx x_base = find_base_term (x); | |
1688 | rtx y_base = find_base_term (y); | |
1689 | ||
1c72c7f6 JC |
1690 | /* If the address itself has no known base see if a known equivalent |
1691 | value has one. If either address still has no known base, nothing | |
1692 | is known about aliasing. */ | |
1693 | if (x_base == 0) | |
1694 | { | |
1695 | rtx x_c; | |
d4b60170 | 1696 | |
1c72c7f6 JC |
1697 | if (! flag_expensive_optimizations || (x_c = canon_rtx (x)) == x) |
1698 | return 1; | |
d4b60170 | 1699 | |
1c72c7f6 JC |
1700 | x_base = find_base_term (x_c); |
1701 | if (x_base == 0) | |
1702 | return 1; | |
1703 | } | |
9ae8ffe7 | 1704 | |
1c72c7f6 JC |
1705 | if (y_base == 0) |
1706 | { | |
1707 | rtx y_c; | |
1708 | if (! flag_expensive_optimizations || (y_c = canon_rtx (y)) == y) | |
1709 | return 1; | |
d4b60170 | 1710 | |
1c72c7f6 JC |
1711 | y_base = find_base_term (y_c); |
1712 | if (y_base == 0) | |
1713 | return 1; | |
1714 | } | |
1715 | ||
1716 | /* If the base addresses are equal nothing is known about aliasing. */ | |
1717 | if (rtx_equal_p (x_base, y_base)) | |
9ae8ffe7 JL |
1718 | return 1; |
1719 | ||
435da628 UB |
1720 | /* The base addresses are different expressions. If they are not accessed |
1721 | via AND, there is no conflict. We can bring knowledge of object | |
1722 | alignment into play here. For example, on alpha, "char a, b;" can | |
1723 | alias one another, though "char a; long b;" cannot. AND addesses may | |
1724 | implicitly alias surrounding objects; i.e. unaligned access in DImode | |
1725 | via AND address can alias all surrounding object types except those | |
1726 | with aligment 8 or higher. */ | |
1727 | if (GET_CODE (x) == AND && GET_CODE (y) == AND) | |
1728 | return 1; | |
1729 | if (GET_CODE (x) == AND | |
481683e1 | 1730 | && (!CONST_INT_P (XEXP (x, 1)) |
435da628 UB |
1731 | || (int) GET_MODE_UNIT_SIZE (y_mode) < -INTVAL (XEXP (x, 1)))) |
1732 | return 1; | |
1733 | if (GET_CODE (y) == AND | |
481683e1 | 1734 | && (!CONST_INT_P (XEXP (y, 1)) |
435da628 UB |
1735 | || (int) GET_MODE_UNIT_SIZE (x_mode) < -INTVAL (XEXP (y, 1)))) |
1736 | return 1; | |
1737 | ||
1738 | /* Differing symbols not accessed via AND never alias. */ | |
9ae8ffe7 | 1739 | if (GET_CODE (x_base) != ADDRESS && GET_CODE (y_base) != ADDRESS) |
435da628 | 1740 | return 0; |
9ae8ffe7 JL |
1741 | |
1742 | /* If one address is a stack reference there can be no alias: | |
1743 | stack references using different base registers do not alias, | |
1744 | a stack reference can not alias a parameter, and a stack reference | |
1745 | can not alias a global. */ | |
1746 | if ((GET_CODE (x_base) == ADDRESS && GET_MODE (x_base) == Pmode) | |
1747 | || (GET_CODE (y_base) == ADDRESS && GET_MODE (y_base) == Pmode)) | |
1748 | return 0; | |
1749 | ||
0d3c82d6 | 1750 | return 1; |
9ae8ffe7 JL |
1751 | } |
1752 | ||
eab5c70a BS |
1753 | /* Convert the address X into something we can use. This is done by returning |
1754 | it unchanged unless it is a value; in the latter case we call cselib to get | |
1755 | a more useful rtx. */ | |
3bdf5ad1 | 1756 | |
a13d4ebf | 1757 | rtx |
4682ae04 | 1758 | get_addr (rtx x) |
eab5c70a BS |
1759 | { |
1760 | cselib_val *v; | |
1761 | struct elt_loc_list *l; | |
1762 | ||
1763 | if (GET_CODE (x) != VALUE) | |
1764 | return x; | |
1765 | v = CSELIB_VAL_PTR (x); | |
40e02b4a JH |
1766 | if (v) |
1767 | { | |
1768 | for (l = v->locs; l; l = l->next) | |
1769 | if (CONSTANT_P (l->loc)) | |
1770 | return l->loc; | |
1771 | for (l = v->locs; l; l = l->next) | |
3c0cb5de | 1772 | if (!REG_P (l->loc) && !MEM_P (l->loc)) |
40e02b4a JH |
1773 | return l->loc; |
1774 | if (v->locs) | |
1775 | return v->locs->loc; | |
1776 | } | |
eab5c70a BS |
1777 | return x; |
1778 | } | |
1779 | ||
39cec1ac MH |
1780 | /* Return the address of the (N_REFS + 1)th memory reference to ADDR |
1781 | where SIZE is the size in bytes of the memory reference. If ADDR | |
1782 | is not modified by the memory reference then ADDR is returned. */ | |
1783 | ||
04e2b4d3 | 1784 | static rtx |
4682ae04 | 1785 | addr_side_effect_eval (rtx addr, int size, int n_refs) |
39cec1ac MH |
1786 | { |
1787 | int offset = 0; | |
ca7fd9cd | 1788 | |
39cec1ac MH |
1789 | switch (GET_CODE (addr)) |
1790 | { | |
1791 | case PRE_INC: | |
1792 | offset = (n_refs + 1) * size; | |
1793 | break; | |
1794 | case PRE_DEC: | |
1795 | offset = -(n_refs + 1) * size; | |
1796 | break; | |
1797 | case POST_INC: | |
1798 | offset = n_refs * size; | |
1799 | break; | |
1800 | case POST_DEC: | |
1801 | offset = -n_refs * size; | |
1802 | break; | |
1803 | ||
1804 | default: | |
1805 | return addr; | |
1806 | } | |
ca7fd9cd | 1807 | |
39cec1ac | 1808 | if (offset) |
45183e03 | 1809 | addr = gen_rtx_PLUS (GET_MODE (addr), XEXP (addr, 0), |
c22cacf3 | 1810 | GEN_INT (offset)); |
39cec1ac MH |
1811 | else |
1812 | addr = XEXP (addr, 0); | |
45183e03 | 1813 | addr = canon_rtx (addr); |
39cec1ac MH |
1814 | |
1815 | return addr; | |
1816 | } | |
1817 | ||
f47e08d9 RG |
1818 | /* Return one if X and Y (memory addresses) reference the |
1819 | same location in memory or if the references overlap. | |
1820 | Return zero if they do not overlap, else return | |
1821 | minus one in which case they still might reference the same location. | |
1822 | ||
1823 | C is an offset accumulator. When | |
9ae8ffe7 JL |
1824 | C is nonzero, we are testing aliases between X and Y + C. |
1825 | XSIZE is the size in bytes of the X reference, | |
1826 | similarly YSIZE is the size in bytes for Y. | |
45183e03 | 1827 | Expect that canon_rtx has been already called for X and Y. |
9ae8ffe7 JL |
1828 | |
1829 | If XSIZE or YSIZE is zero, we do not know the amount of memory being | |
1830 | referenced (the reference was BLKmode), so make the most pessimistic | |
1831 | assumptions. | |
1832 | ||
c02f035f RH |
1833 | If XSIZE or YSIZE is negative, we may access memory outside the object |
1834 | being referenced as a side effect. This can happen when using AND to | |
1835 | align memory references, as is done on the Alpha. | |
1836 | ||
9ae8ffe7 | 1837 | Nice to notice that varying addresses cannot conflict with fp if no |
f47e08d9 RG |
1838 | local variables had their addresses taken, but that's too hard now. |
1839 | ||
1840 | ??? Contrary to the tree alias oracle this does not return | |
1841 | one for X + non-constant and Y + non-constant when X and Y are equal. | |
1842 | If that is fixed the TBAA hack for union type-punning can be removed. */ | |
9ae8ffe7 | 1843 | |
9ae8ffe7 | 1844 | static int |
4682ae04 | 1845 | memrefs_conflict_p (int xsize, rtx x, int ysize, rtx y, HOST_WIDE_INT c) |
9ae8ffe7 | 1846 | { |
eab5c70a | 1847 | if (GET_CODE (x) == VALUE) |
5312b066 JJ |
1848 | { |
1849 | if (REG_P (y)) | |
1850 | { | |
24f8d71e JJ |
1851 | struct elt_loc_list *l = NULL; |
1852 | if (CSELIB_VAL_PTR (x)) | |
1853 | for (l = CSELIB_VAL_PTR (x)->locs; l; l = l->next) | |
1854 | if (REG_P (l->loc) && rtx_equal_for_memref_p (l->loc, y)) | |
1855 | break; | |
5312b066 JJ |
1856 | if (l) |
1857 | x = y; | |
1858 | else | |
1859 | x = get_addr (x); | |
1860 | } | |
1861 | /* Don't call get_addr if y is the same VALUE. */ | |
1862 | else if (x != y) | |
1863 | x = get_addr (x); | |
1864 | } | |
eab5c70a | 1865 | if (GET_CODE (y) == VALUE) |
5312b066 JJ |
1866 | { |
1867 | if (REG_P (x)) | |
1868 | { | |
24f8d71e JJ |
1869 | struct elt_loc_list *l = NULL; |
1870 | if (CSELIB_VAL_PTR (y)) | |
1871 | for (l = CSELIB_VAL_PTR (y)->locs; l; l = l->next) | |
1872 | if (REG_P (l->loc) && rtx_equal_for_memref_p (l->loc, x)) | |
1873 | break; | |
5312b066 JJ |
1874 | if (l) |
1875 | y = x; | |
1876 | else | |
1877 | y = get_addr (y); | |
1878 | } | |
1879 | /* Don't call get_addr if x is the same VALUE. */ | |
1880 | else if (y != x) | |
1881 | y = get_addr (y); | |
1882 | } | |
9ae8ffe7 JL |
1883 | if (GET_CODE (x) == HIGH) |
1884 | x = XEXP (x, 0); | |
1885 | else if (GET_CODE (x) == LO_SUM) | |
1886 | x = XEXP (x, 1); | |
1887 | else | |
45183e03 | 1888 | x = addr_side_effect_eval (x, xsize, 0); |
9ae8ffe7 JL |
1889 | if (GET_CODE (y) == HIGH) |
1890 | y = XEXP (y, 0); | |
1891 | else if (GET_CODE (y) == LO_SUM) | |
1892 | y = XEXP (y, 1); | |
1893 | else | |
45183e03 | 1894 | y = addr_side_effect_eval (y, ysize, 0); |
9ae8ffe7 JL |
1895 | |
1896 | if (rtx_equal_for_memref_p (x, y)) | |
1897 | { | |
c02f035f | 1898 | if (xsize <= 0 || ysize <= 0) |
9ae8ffe7 JL |
1899 | return 1; |
1900 | if (c >= 0 && xsize > c) | |
1901 | return 1; | |
1902 | if (c < 0 && ysize+c > 0) | |
1903 | return 1; | |
1904 | return 0; | |
1905 | } | |
1906 | ||
6e73e666 JC |
1907 | /* This code used to check for conflicts involving stack references and |
1908 | globals but the base address alias code now handles these cases. */ | |
9ae8ffe7 JL |
1909 | |
1910 | if (GET_CODE (x) == PLUS) | |
1911 | { | |
1912 | /* The fact that X is canonicalized means that this | |
1913 | PLUS rtx is canonicalized. */ | |
1914 | rtx x0 = XEXP (x, 0); | |
1915 | rtx x1 = XEXP (x, 1); | |
1916 | ||
1917 | if (GET_CODE (y) == PLUS) | |
1918 | { | |
1919 | /* The fact that Y is canonicalized means that this | |
1920 | PLUS rtx is canonicalized. */ | |
1921 | rtx y0 = XEXP (y, 0); | |
1922 | rtx y1 = XEXP (y, 1); | |
1923 | ||
1924 | if (rtx_equal_for_memref_p (x1, y1)) | |
1925 | return memrefs_conflict_p (xsize, x0, ysize, y0, c); | |
1926 | if (rtx_equal_for_memref_p (x0, y0)) | |
1927 | return memrefs_conflict_p (xsize, x1, ysize, y1, c); | |
481683e1 | 1928 | if (CONST_INT_P (x1)) |
63be02db | 1929 | { |
481683e1 | 1930 | if (CONST_INT_P (y1)) |
63be02db JM |
1931 | return memrefs_conflict_p (xsize, x0, ysize, y0, |
1932 | c - INTVAL (x1) + INTVAL (y1)); | |
1933 | else | |
1934 | return memrefs_conflict_p (xsize, x0, ysize, y, | |
1935 | c - INTVAL (x1)); | |
1936 | } | |
481683e1 | 1937 | else if (CONST_INT_P (y1)) |
9ae8ffe7 JL |
1938 | return memrefs_conflict_p (xsize, x, ysize, y0, c + INTVAL (y1)); |
1939 | ||
f47e08d9 | 1940 | return -1; |
9ae8ffe7 | 1941 | } |
481683e1 | 1942 | else if (CONST_INT_P (x1)) |
9ae8ffe7 JL |
1943 | return memrefs_conflict_p (xsize, x0, ysize, y, c - INTVAL (x1)); |
1944 | } | |
1945 | else if (GET_CODE (y) == PLUS) | |
1946 | { | |
1947 | /* The fact that Y is canonicalized means that this | |
1948 | PLUS rtx is canonicalized. */ | |
1949 | rtx y0 = XEXP (y, 0); | |
1950 | rtx y1 = XEXP (y, 1); | |
1951 | ||
481683e1 | 1952 | if (CONST_INT_P (y1)) |
9ae8ffe7 JL |
1953 | return memrefs_conflict_p (xsize, x, ysize, y0, c + INTVAL (y1)); |
1954 | else | |
f47e08d9 | 1955 | return -1; |
9ae8ffe7 JL |
1956 | } |
1957 | ||
1958 | if (GET_CODE (x) == GET_CODE (y)) | |
1959 | switch (GET_CODE (x)) | |
1960 | { | |
1961 | case MULT: | |
1962 | { | |
1963 | /* Handle cases where we expect the second operands to be the | |
1964 | same, and check only whether the first operand would conflict | |
1965 | or not. */ | |
1966 | rtx x0, y0; | |
1967 | rtx x1 = canon_rtx (XEXP (x, 1)); | |
1968 | rtx y1 = canon_rtx (XEXP (y, 1)); | |
1969 | if (! rtx_equal_for_memref_p (x1, y1)) | |
f47e08d9 | 1970 | return -1; |
9ae8ffe7 JL |
1971 | x0 = canon_rtx (XEXP (x, 0)); |
1972 | y0 = canon_rtx (XEXP (y, 0)); | |
1973 | if (rtx_equal_for_memref_p (x0, y0)) | |
1974 | return (xsize == 0 || ysize == 0 | |
1975 | || (c >= 0 && xsize > c) || (c < 0 && ysize+c > 0)); | |
1976 | ||
1977 | /* Can't properly adjust our sizes. */ | |
481683e1 | 1978 | if (!CONST_INT_P (x1)) |
f47e08d9 | 1979 | return -1; |
9ae8ffe7 JL |
1980 | xsize /= INTVAL (x1); |
1981 | ysize /= INTVAL (x1); | |
1982 | c /= INTVAL (x1); | |
1983 | return memrefs_conflict_p (xsize, x0, ysize, y0, c); | |
1984 | } | |
1d300e19 KG |
1985 | |
1986 | default: | |
1987 | break; | |
9ae8ffe7 JL |
1988 | } |
1989 | ||
1990 | /* Treat an access through an AND (e.g. a subword access on an Alpha) | |
ca7fd9cd | 1991 | as an access with indeterminate size. Assume that references |
56ee9281 RH |
1992 | besides AND are aligned, so if the size of the other reference is |
1993 | at least as large as the alignment, assume no other overlap. */ | |
481683e1 | 1994 | if (GET_CODE (x) == AND && CONST_INT_P (XEXP (x, 1))) |
56ee9281 | 1995 | { |
02e3377d | 1996 | if (GET_CODE (y) == AND || ysize < -INTVAL (XEXP (x, 1))) |
56ee9281 | 1997 | xsize = -1; |
45183e03 | 1998 | return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)), ysize, y, c); |
56ee9281 | 1999 | } |
481683e1 | 2000 | if (GET_CODE (y) == AND && CONST_INT_P (XEXP (y, 1))) |
c02f035f | 2001 | { |
56ee9281 | 2002 | /* ??? If we are indexing far enough into the array/structure, we |
ca7fd9cd | 2003 | may yet be able to determine that we can not overlap. But we |
c02f035f | 2004 | also need to that we are far enough from the end not to overlap |
56ee9281 | 2005 | a following reference, so we do nothing with that for now. */ |
02e3377d | 2006 | if (GET_CODE (x) == AND || xsize < -INTVAL (XEXP (y, 1))) |
56ee9281 | 2007 | ysize = -1; |
45183e03 | 2008 | return memrefs_conflict_p (xsize, x, ysize, canon_rtx (XEXP (y, 0)), c); |
c02f035f | 2009 | } |
9ae8ffe7 JL |
2010 | |
2011 | if (CONSTANT_P (x)) | |
2012 | { | |
481683e1 | 2013 | if (CONST_INT_P (x) && CONST_INT_P (y)) |
9ae8ffe7 JL |
2014 | { |
2015 | c += (INTVAL (y) - INTVAL (x)); | |
c02f035f | 2016 | return (xsize <= 0 || ysize <= 0 |
9ae8ffe7 JL |
2017 | || (c >= 0 && xsize > c) || (c < 0 && ysize+c > 0)); |
2018 | } | |
2019 | ||
2020 | if (GET_CODE (x) == CONST) | |
2021 | { | |
2022 | if (GET_CODE (y) == CONST) | |
2023 | return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)), | |
2024 | ysize, canon_rtx (XEXP (y, 0)), c); | |
2025 | else | |
2026 | return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)), | |
2027 | ysize, y, c); | |
2028 | } | |
2029 | if (GET_CODE (y) == CONST) | |
2030 | return memrefs_conflict_p (xsize, x, ysize, | |
2031 | canon_rtx (XEXP (y, 0)), c); | |
2032 | ||
2033 | if (CONSTANT_P (y)) | |
b949ea8b | 2034 | return (xsize <= 0 || ysize <= 0 |
c02f035f | 2035 | || (rtx_equal_for_memref_p (x, y) |
b949ea8b | 2036 | && ((c >= 0 && xsize > c) || (c < 0 && ysize+c > 0)))); |
9ae8ffe7 | 2037 | |
f47e08d9 | 2038 | return -1; |
9ae8ffe7 | 2039 | } |
f47e08d9 RG |
2040 | |
2041 | return -1; | |
9ae8ffe7 JL |
2042 | } |
2043 | ||
2044 | /* Functions to compute memory dependencies. | |
2045 | ||
2046 | Since we process the insns in execution order, we can build tables | |
2047 | to keep track of what registers are fixed (and not aliased), what registers | |
2048 | are varying in known ways, and what registers are varying in unknown | |
2049 | ways. | |
2050 | ||
2051 | If both memory references are volatile, then there must always be a | |
2052 | dependence between the two references, since their order can not be | |
2053 | changed. A volatile and non-volatile reference can be interchanged | |
ca7fd9cd | 2054 | though. |
9ae8ffe7 | 2055 | |
dc1618bc RK |
2056 | A MEM_IN_STRUCT reference at a non-AND varying address can never |
2057 | conflict with a non-MEM_IN_STRUCT reference at a fixed address. We | |
2058 | also must allow AND addresses, because they may generate accesses | |
2059 | outside the object being referenced. This is used to generate | |
2060 | aligned addresses from unaligned addresses, for instance, the alpha | |
2061 | storeqi_unaligned pattern. */ | |
9ae8ffe7 JL |
2062 | |
2063 | /* Read dependence: X is read after read in MEM takes place. There can | |
2064 | only be a dependence here if both reads are volatile. */ | |
2065 | ||
2066 | int | |
4f588890 | 2067 | read_dependence (const_rtx mem, const_rtx x) |
9ae8ffe7 JL |
2068 | { |
2069 | return MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem); | |
2070 | } | |
2071 | ||
c6df88cb MM |
2072 | /* Returns MEM1 if and only if MEM1 is a scalar at a fixed address and |
2073 | MEM2 is a reference to a structure at a varying address, or returns | |
2074 | MEM2 if vice versa. Otherwise, returns NULL_RTX. If a non-NULL | |
2075 | value is returned MEM1 and MEM2 can never alias. VARIES_P is used | |
2076 | to decide whether or not an address may vary; it should return | |
eab5c70a BS |
2077 | nonzero whenever variation is possible. |
2078 | MEM1_ADDR and MEM2_ADDR are the addresses of MEM1 and MEM2. */ | |
ca7fd9cd | 2079 | |
4f588890 KG |
2080 | static const_rtx |
2081 | fixed_scalar_and_varying_struct_p (const_rtx mem1, const_rtx mem2, rtx mem1_addr, | |
4682ae04 | 2082 | rtx mem2_addr, |
4f588890 | 2083 | bool (*varies_p) (const_rtx, bool)) |
ca7fd9cd | 2084 | { |
3e0abe15 GK |
2085 | if (! flag_strict_aliasing) |
2086 | return NULL_RTX; | |
2087 | ||
afa8f0fb AP |
2088 | if (MEM_ALIAS_SET (mem2) |
2089 | && MEM_SCALAR_P (mem1) && MEM_IN_STRUCT_P (mem2) | |
e38fe8e0 | 2090 | && !varies_p (mem1_addr, 1) && varies_p (mem2_addr, 1)) |
c6df88cb MM |
2091 | /* MEM1 is a scalar at a fixed address; MEM2 is a struct at a |
2092 | varying address. */ | |
2093 | return mem1; | |
2094 | ||
afa8f0fb AP |
2095 | if (MEM_ALIAS_SET (mem1) |
2096 | && MEM_IN_STRUCT_P (mem1) && MEM_SCALAR_P (mem2) | |
e38fe8e0 | 2097 | && varies_p (mem1_addr, 1) && !varies_p (mem2_addr, 1)) |
c6df88cb MM |
2098 | /* MEM2 is a scalar at a fixed address; MEM1 is a struct at a |
2099 | varying address. */ | |
2100 | return mem2; | |
2101 | ||
2102 | return NULL_RTX; | |
2103 | } | |
2104 | ||
2105 | /* Returns nonzero if something about the mode or address format MEM1 | |
2106 | indicates that it might well alias *anything*. */ | |
2107 | ||
2c72b78f | 2108 | static int |
4f588890 | 2109 | aliases_everything_p (const_rtx mem) |
c6df88cb | 2110 | { |
c6df88cb | 2111 | if (GET_CODE (XEXP (mem, 0)) == AND) |
35fd3193 | 2112 | /* If the address is an AND, it's very hard to know at what it is |
c6df88cb MM |
2113 | actually pointing. */ |
2114 | return 1; | |
ca7fd9cd | 2115 | |
c6df88cb MM |
2116 | return 0; |
2117 | } | |
2118 | ||
998d7deb RH |
2119 | /* Return true if we can determine that the fields referenced cannot |
2120 | overlap for any pair of objects. */ | |
2121 | ||
2122 | static bool | |
4f588890 | 2123 | nonoverlapping_component_refs_p (const_tree x, const_tree y) |
998d7deb | 2124 | { |
4f588890 | 2125 | const_tree fieldx, fieldy, typex, typey, orig_y; |
998d7deb | 2126 | |
4c7af939 AB |
2127 | if (!flag_strict_aliasing) |
2128 | return false; | |
2129 | ||
998d7deb RH |
2130 | do |
2131 | { | |
2132 | /* The comparison has to be done at a common type, since we don't | |
d6a7951f | 2133 | know how the inheritance hierarchy works. */ |
998d7deb RH |
2134 | orig_y = y; |
2135 | do | |
2136 | { | |
2137 | fieldx = TREE_OPERAND (x, 1); | |
c05a0766 | 2138 | typex = TYPE_MAIN_VARIANT (DECL_FIELD_CONTEXT (fieldx)); |
998d7deb RH |
2139 | |
2140 | y = orig_y; | |
2141 | do | |
2142 | { | |
2143 | fieldy = TREE_OPERAND (y, 1); | |
c05a0766 | 2144 | typey = TYPE_MAIN_VARIANT (DECL_FIELD_CONTEXT (fieldy)); |
998d7deb RH |
2145 | |
2146 | if (typex == typey) | |
2147 | goto found; | |
2148 | ||
2149 | y = TREE_OPERAND (y, 0); | |
2150 | } | |
2151 | while (y && TREE_CODE (y) == COMPONENT_REF); | |
2152 | ||
2153 | x = TREE_OPERAND (x, 0); | |
2154 | } | |
2155 | while (x && TREE_CODE (x) == COMPONENT_REF); | |
998d7deb | 2156 | /* Never found a common type. */ |
c05a0766 | 2157 | return false; |
998d7deb RH |
2158 | |
2159 | found: | |
2160 | /* If we're left with accessing different fields of a structure, | |
2161 | then no overlap. */ | |
2162 | if (TREE_CODE (typex) == RECORD_TYPE | |
2163 | && fieldx != fieldy) | |
2164 | return true; | |
2165 | ||
2166 | /* The comparison on the current field failed. If we're accessing | |
2167 | a very nested structure, look at the next outer level. */ | |
2168 | x = TREE_OPERAND (x, 0); | |
2169 | y = TREE_OPERAND (y, 0); | |
2170 | } | |
2171 | while (x && y | |
2172 | && TREE_CODE (x) == COMPONENT_REF | |
2173 | && TREE_CODE (y) == COMPONENT_REF); | |
ca7fd9cd | 2174 | |
998d7deb RH |
2175 | return false; |
2176 | } | |
2177 | ||
2178 | /* Look at the bottom of the COMPONENT_REF list for a DECL, and return it. */ | |
2179 | ||
2180 | static tree | |
4682ae04 | 2181 | decl_for_component_ref (tree x) |
998d7deb RH |
2182 | { |
2183 | do | |
2184 | { | |
2185 | x = TREE_OPERAND (x, 0); | |
2186 | } | |
2187 | while (x && TREE_CODE (x) == COMPONENT_REF); | |
2188 | ||
2189 | return x && DECL_P (x) ? x : NULL_TREE; | |
2190 | } | |
2191 | ||
2192 | /* Walk up the COMPONENT_REF list and adjust OFFSET to compensate for the | |
2193 | offset of the field reference. */ | |
2194 | ||
2195 | static rtx | |
4682ae04 | 2196 | adjust_offset_for_component_ref (tree x, rtx offset) |
998d7deb RH |
2197 | { |
2198 | HOST_WIDE_INT ioffset; | |
2199 | ||
2200 | if (! offset) | |
2201 | return NULL_RTX; | |
2202 | ||
2203 | ioffset = INTVAL (offset); | |
ca7fd9cd | 2204 | do |
998d7deb | 2205 | { |
44de5aeb | 2206 | tree offset = component_ref_field_offset (x); |
998d7deb RH |
2207 | tree field = TREE_OPERAND (x, 1); |
2208 | ||
44de5aeb | 2209 | if (! host_integerp (offset, 1)) |
998d7deb | 2210 | return NULL_RTX; |
44de5aeb | 2211 | ioffset += (tree_low_cst (offset, 1) |
998d7deb RH |
2212 | + (tree_low_cst (DECL_FIELD_BIT_OFFSET (field), 1) |
2213 | / BITS_PER_UNIT)); | |
2214 | ||
2215 | x = TREE_OPERAND (x, 0); | |
2216 | } | |
2217 | while (x && TREE_CODE (x) == COMPONENT_REF); | |
2218 | ||
2219 | return GEN_INT (ioffset); | |
2220 | } | |
2221 | ||
95bd1dd7 | 2222 | /* Return nonzero if we can determine the exprs corresponding to memrefs |
c6ea834c BM |
2223 | X and Y and they do not overlap. |
2224 | If LOOP_VARIANT is set, skip offset-based disambiguation */ | |
a4311dfe | 2225 | |
2e4e39f6 | 2226 | int |
c6ea834c | 2227 | nonoverlapping_memrefs_p (const_rtx x, const_rtx y, bool loop_invariant) |
a4311dfe | 2228 | { |
998d7deb | 2229 | tree exprx = MEM_EXPR (x), expry = MEM_EXPR (y); |
a4311dfe RK |
2230 | rtx rtlx, rtly; |
2231 | rtx basex, basey; | |
998d7deb | 2232 | rtx moffsetx, moffsety; |
a4311dfe RK |
2233 | HOST_WIDE_INT offsetx = 0, offsety = 0, sizex, sizey, tem; |
2234 | ||
998d7deb RH |
2235 | /* Unless both have exprs, we can't tell anything. */ |
2236 | if (exprx == 0 || expry == 0) | |
2237 | return 0; | |
2b22e382 RG |
2238 | |
2239 | /* For spill-slot accesses make sure we have valid offsets. */ | |
2240 | if ((exprx == get_spill_slot_decl (false) | |
2241 | && ! MEM_OFFSET (x)) | |
2242 | || (expry == get_spill_slot_decl (false) | |
2243 | && ! MEM_OFFSET (y))) | |
2244 | return 0; | |
c22cacf3 | 2245 | |
998d7deb RH |
2246 | /* If both are field references, we may be able to determine something. */ |
2247 | if (TREE_CODE (exprx) == COMPONENT_REF | |
2248 | && TREE_CODE (expry) == COMPONENT_REF | |
2249 | && nonoverlapping_component_refs_p (exprx, expry)) | |
2250 | return 1; | |
2251 | ||
c22cacf3 | 2252 | |
998d7deb RH |
2253 | /* If the field reference test failed, look at the DECLs involved. */ |
2254 | moffsetx = MEM_OFFSET (x); | |
2255 | if (TREE_CODE (exprx) == COMPONENT_REF) | |
2256 | { | |
2e0c984c RG |
2257 | tree t = decl_for_component_ref (exprx); |
2258 | if (! t) | |
2259 | return 0; | |
2260 | moffsetx = adjust_offset_for_component_ref (exprx, moffsetx); | |
2261 | exprx = t; | |
998d7deb | 2262 | } |
c67a1cf6 | 2263 | |
998d7deb RH |
2264 | moffsety = MEM_OFFSET (y); |
2265 | if (TREE_CODE (expry) == COMPONENT_REF) | |
2266 | { | |
2e0c984c RG |
2267 | tree t = decl_for_component_ref (expry); |
2268 | if (! t) | |
2269 | return 0; | |
2270 | moffsety = adjust_offset_for_component_ref (expry, moffsety); | |
2271 | expry = t; | |
998d7deb RH |
2272 | } |
2273 | ||
2274 | if (! DECL_P (exprx) || ! DECL_P (expry)) | |
a4311dfe RK |
2275 | return 0; |
2276 | ||
1307c758 RG |
2277 | /* With invalid code we can end up storing into the constant pool. |
2278 | Bail out to avoid ICEing when creating RTL for this. | |
2279 | See gfortran.dg/lto/20091028-2_0.f90. */ | |
2280 | if (TREE_CODE (exprx) == CONST_DECL | |
2281 | || TREE_CODE (expry) == CONST_DECL) | |
2282 | return 1; | |
2283 | ||
998d7deb RH |
2284 | rtlx = DECL_RTL (exprx); |
2285 | rtly = DECL_RTL (expry); | |
a4311dfe | 2286 | |
1edcd60b RK |
2287 | /* If either RTL is not a MEM, it must be a REG or CONCAT, meaning they |
2288 | can't overlap unless they are the same because we never reuse that part | |
2289 | of the stack frame used for locals for spilled pseudos. */ | |
3c0cb5de | 2290 | if ((!MEM_P (rtlx) || !MEM_P (rtly)) |
1edcd60b | 2291 | && ! rtx_equal_p (rtlx, rtly)) |
a4311dfe RK |
2292 | return 1; |
2293 | ||
09e881c9 BE |
2294 | /* If we have MEMs refering to different address spaces (which can |
2295 | potentially overlap), we cannot easily tell from the addresses | |
2296 | whether the references overlap. */ | |
2297 | if (MEM_P (rtlx) && MEM_P (rtly) | |
2298 | && MEM_ADDR_SPACE (rtlx) != MEM_ADDR_SPACE (rtly)) | |
2299 | return 0; | |
2300 | ||
a4311dfe RK |
2301 | /* Get the base and offsets of both decls. If either is a register, we |
2302 | know both are and are the same, so use that as the base. The only | |
2303 | we can avoid overlap is if we can deduce that they are nonoverlapping | |
2304 | pieces of that decl, which is very rare. */ | |
3c0cb5de | 2305 | basex = MEM_P (rtlx) ? XEXP (rtlx, 0) : rtlx; |
481683e1 | 2306 | if (GET_CODE (basex) == PLUS && CONST_INT_P (XEXP (basex, 1))) |
a4311dfe RK |
2307 | offsetx = INTVAL (XEXP (basex, 1)), basex = XEXP (basex, 0); |
2308 | ||
3c0cb5de | 2309 | basey = MEM_P (rtly) ? XEXP (rtly, 0) : rtly; |
481683e1 | 2310 | if (GET_CODE (basey) == PLUS && CONST_INT_P (XEXP (basey, 1))) |
a4311dfe RK |
2311 | offsety = INTVAL (XEXP (basey, 1)), basey = XEXP (basey, 0); |
2312 | ||
d746694a | 2313 | /* If the bases are different, we know they do not overlap if both |
ca7fd9cd | 2314 | are constants or if one is a constant and the other a pointer into the |
d746694a RK |
2315 | stack frame. Otherwise a different base means we can't tell if they |
2316 | overlap or not. */ | |
2317 | if (! rtx_equal_p (basex, basey)) | |
ca7fd9cd KH |
2318 | return ((CONSTANT_P (basex) && CONSTANT_P (basey)) |
2319 | || (CONSTANT_P (basex) && REG_P (basey) | |
2320 | && REGNO_PTR_FRAME_P (REGNO (basey))) | |
2321 | || (CONSTANT_P (basey) && REG_P (basex) | |
2322 | && REGNO_PTR_FRAME_P (REGNO (basex)))); | |
a4311dfe | 2323 | |
c6ea834c BM |
2324 | /* Offset based disambiguation not appropriate for loop invariant */ |
2325 | if (loop_invariant) | |
2326 | return 0; | |
2327 | ||
3c0cb5de | 2328 | sizex = (!MEM_P (rtlx) ? (int) GET_MODE_SIZE (GET_MODE (rtlx)) |
a4311dfe RK |
2329 | : MEM_SIZE (rtlx) ? INTVAL (MEM_SIZE (rtlx)) |
2330 | : -1); | |
3c0cb5de | 2331 | sizey = (!MEM_P (rtly) ? (int) GET_MODE_SIZE (GET_MODE (rtly)) |
a4311dfe RK |
2332 | : MEM_SIZE (rtly) ? INTVAL (MEM_SIZE (rtly)) : |
2333 | -1); | |
2334 | ||
0af5bc3e RK |
2335 | /* If we have an offset for either memref, it can update the values computed |
2336 | above. */ | |
998d7deb RH |
2337 | if (moffsetx) |
2338 | offsetx += INTVAL (moffsetx), sizex -= INTVAL (moffsetx); | |
2339 | if (moffsety) | |
2340 | offsety += INTVAL (moffsety), sizey -= INTVAL (moffsety); | |
a4311dfe | 2341 | |
0af5bc3e | 2342 | /* If a memref has both a size and an offset, we can use the smaller size. |
efc981bb | 2343 | We can't do this if the offset isn't known because we must view this |
0af5bc3e | 2344 | memref as being anywhere inside the DECL's MEM. */ |
998d7deb | 2345 | if (MEM_SIZE (x) && moffsetx) |
a4311dfe | 2346 | sizex = INTVAL (MEM_SIZE (x)); |
998d7deb | 2347 | if (MEM_SIZE (y) && moffsety) |
a4311dfe RK |
2348 | sizey = INTVAL (MEM_SIZE (y)); |
2349 | ||
2350 | /* Put the values of the memref with the lower offset in X's values. */ | |
2351 | if (offsetx > offsety) | |
2352 | { | |
2353 | tem = offsetx, offsetx = offsety, offsety = tem; | |
2354 | tem = sizex, sizex = sizey, sizey = tem; | |
2355 | } | |
2356 | ||
2357 | /* If we don't know the size of the lower-offset value, we can't tell | |
2358 | if they conflict. Otherwise, we do the test. */ | |
a6f7c915 | 2359 | return sizex >= 0 && offsety >= offsetx + sizex; |
a4311dfe RK |
2360 | } |
2361 | ||
9362286d SB |
2362 | /* Helper for true_dependence and canon_true_dependence. |
2363 | Checks for true dependence: X is read after store in MEM takes place. | |
9ae8ffe7 | 2364 | |
9362286d SB |
2365 | VARIES is the function that should be used as rtx_varies function. |
2366 | ||
2367 | If MEM_CANONICALIZED is FALSE, then X_ADDR and MEM_ADDR should be | |
2368 | NULL_RTX, and the canonical addresses of MEM and X are both computed | |
2369 | here. If MEM_CANONICALIZED, then MEM must be already canonicalized. | |
2370 | ||
2371 | If X_ADDR is non-NULL, it is used in preference of XEXP (x, 0). | |
2372 | ||
2373 | Returns 1 if there is a true dependence, 0 otherwise. */ | |
2374 | ||
2375 | static int | |
2376 | true_dependence_1 (const_rtx mem, enum machine_mode mem_mode, rtx mem_addr, | |
2377 | const_rtx x, rtx x_addr, bool (*varies) (const_rtx, bool), | |
2378 | bool mem_canonicalized) | |
9ae8ffe7 | 2379 | { |
49982682 | 2380 | rtx base; |
f47e08d9 | 2381 | int ret; |
9ae8ffe7 | 2382 | |
9362286d SB |
2383 | gcc_checking_assert (mem_canonicalized ? (mem_addr != NULL_RTX) |
2384 | : (mem_addr == NULL_RTX && x_addr == NULL_RTX)); | |
2385 | ||
9ae8ffe7 JL |
2386 | if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) |
2387 | return 1; | |
2388 | ||
c4484b8f | 2389 | /* (mem:BLK (scratch)) is a special mechanism to conflict with everything. |
ac3768f6 | 2390 | This is used in epilogue deallocation functions, and in cselib. */ |
c4484b8f RH |
2391 | if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH) |
2392 | return 1; | |
2393 | if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH) | |
2394 | return 1; | |
9cd9e512 RH |
2395 | if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER |
2396 | || MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER) | |
2397 | return 1; | |
c4484b8f | 2398 | |
389fdba0 RH |
2399 | /* Read-only memory is by definition never modified, and therefore can't |
2400 | conflict with anything. We don't expect to find read-only set on MEM, | |
41806d92 | 2401 | but stupid user tricks can produce them, so don't die. */ |
389fdba0 | 2402 | if (MEM_READONLY_P (x)) |
9ae8ffe7 JL |
2403 | return 0; |
2404 | ||
09e881c9 BE |
2405 | /* If we have MEMs refering to different address spaces (which can |
2406 | potentially overlap), we cannot easily tell from the addresses | |
2407 | whether the references overlap. */ | |
2408 | if (MEM_ADDR_SPACE (mem) != MEM_ADDR_SPACE (x)) | |
2409 | return 1; | |
2410 | ||
9362286d SB |
2411 | if (! mem_addr) |
2412 | { | |
2413 | mem_addr = XEXP (mem, 0); | |
2414 | if (mem_mode == VOIDmode) | |
2415 | mem_mode = GET_MODE (mem); | |
2416 | } | |
2417 | ||
2418 | if (! x_addr) | |
2147c71c | 2419 | { |
a522de15 SB |
2420 | x_addr = XEXP (x, 0); |
2421 | if (!((GET_CODE (x_addr) == VALUE | |
2422 | && GET_CODE (mem_addr) != VALUE | |
2423 | && reg_mentioned_p (x_addr, mem_addr)) | |
2424 | || (GET_CODE (x_addr) != VALUE | |
2425 | && GET_CODE (mem_addr) == VALUE | |
2426 | && reg_mentioned_p (mem_addr, x_addr)))) | |
2427 | { | |
2428 | x_addr = get_addr (x_addr); | |
2429 | if (! mem_canonicalized) | |
2430 | mem_addr = get_addr (mem_addr); | |
2431 | } | |
2147c71c | 2432 | } |
eab5c70a | 2433 | |
55efb413 JW |
2434 | base = find_base_term (x_addr); |
2435 | if (base && (GET_CODE (base) == LABEL_REF | |
2436 | || (GET_CODE (base) == SYMBOL_REF | |
2437 | && CONSTANT_POOL_ADDRESS_P (base)))) | |
2438 | return 0; | |
2439 | ||
eab5c70a | 2440 | if (! base_alias_check (x_addr, mem_addr, GET_MODE (x), mem_mode)) |
1c72c7f6 JC |
2441 | return 0; |
2442 | ||
eab5c70a | 2443 | x_addr = canon_rtx (x_addr); |
9362286d SB |
2444 | if (!mem_canonicalized) |
2445 | mem_addr = canon_rtx (mem_addr); | |
6e73e666 | 2446 | |
f47e08d9 RG |
2447 | if ((ret = memrefs_conflict_p (GET_MODE_SIZE (mem_mode), mem_addr, |
2448 | SIZE_FOR_MODE (x), x_addr, 0)) != -1) | |
2449 | return ret; | |
2450 | ||
2451 | if (DIFFERENT_ALIAS_SETS_P (x, mem)) | |
2452 | return 0; | |
2453 | ||
c6ea834c | 2454 | if (nonoverlapping_memrefs_p (mem, x, false)) |
0211b6ab JW |
2455 | return 0; |
2456 | ||
c6df88cb | 2457 | if (aliases_everything_p (x)) |
0211b6ab JW |
2458 | return 1; |
2459 | ||
f5143c46 | 2460 | /* We cannot use aliases_everything_p to test MEM, since we must look |
9362286d | 2461 | at MEM_ADDR, rather than XEXP (mem, 0). */ |
c6df88cb | 2462 | if (mem_mode == QImode || GET_CODE (mem_addr) == AND) |
a13d4ebf AM |
2463 | return 1; |
2464 | ||
9362286d | 2465 | /* ??? In true_dependence we also allow BLKmode to alias anything. Why |
a13d4ebf AM |
2466 | don't we do this in anti_dependence and output_dependence? */ |
2467 | if (mem_mode == BLKmode || GET_MODE (x) == BLKmode) | |
2468 | return 1; | |
2469 | ||
55b34b5f RG |
2470 | if (fixed_scalar_and_varying_struct_p (mem, x, mem_addr, x_addr, varies)) |
2471 | return 0; | |
2472 | ||
2473 | return rtx_refs_may_alias_p (x, mem, true); | |
a13d4ebf AM |
2474 | } |
2475 | ||
9362286d SB |
2476 | /* True dependence: X is read after store in MEM takes place. */ |
2477 | ||
2478 | int | |
2479 | true_dependence (const_rtx mem, enum machine_mode mem_mode, const_rtx x, | |
2480 | bool (*varies) (const_rtx, bool)) | |
2481 | { | |
2482 | return true_dependence_1 (mem, mem_mode, NULL_RTX, | |
2483 | x, NULL_RTX, varies, | |
2484 | /*mem_canonicalized=*/false); | |
2485 | } | |
2486 | ||
a13d4ebf | 2487 | /* Canonical true dependence: X is read after store in MEM takes place. |
ca7fd9cd KH |
2488 | Variant of true_dependence which assumes MEM has already been |
2489 | canonicalized (hence we no longer do that here). | |
9362286d SB |
2490 | The mem_addr argument has been added, since true_dependence_1 computed |
2491 | this value prior to canonicalizing. */ | |
a13d4ebf AM |
2492 | |
2493 | int | |
4f588890 | 2494 | canon_true_dependence (const_rtx mem, enum machine_mode mem_mode, rtx mem_addr, |
6216f94e | 2495 | const_rtx x, rtx x_addr, bool (*varies) (const_rtx, bool)) |
a13d4ebf | 2496 | { |
9362286d SB |
2497 | return true_dependence_1 (mem, mem_mode, mem_addr, |
2498 | x, x_addr, varies, | |
2499 | /*mem_canonicalized=*/true); | |
9ae8ffe7 JL |
2500 | } |
2501 | ||
da7d8304 | 2502 | /* Returns nonzero if a write to X might alias a previous read from |
389fdba0 | 2503 | (or, if WRITEP is nonzero, a write to) MEM. */ |
9ae8ffe7 | 2504 | |
2c72b78f | 2505 | static int |
4f588890 | 2506 | write_dependence_p (const_rtx mem, const_rtx x, int writep) |
9ae8ffe7 | 2507 | { |
6e73e666 | 2508 | rtx x_addr, mem_addr; |
4f588890 | 2509 | const_rtx fixed_scalar; |
49982682 | 2510 | rtx base; |
f47e08d9 | 2511 | int ret; |
6e73e666 | 2512 | |
9ae8ffe7 JL |
2513 | if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) |
2514 | return 1; | |
2515 | ||
c4484b8f RH |
2516 | /* (mem:BLK (scratch)) is a special mechanism to conflict with everything. |
2517 | This is used in epilogue deallocation functions. */ | |
2518 | if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH) | |
2519 | return 1; | |
2520 | if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH) | |
2521 | return 1; | |
9cd9e512 RH |
2522 | if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER |
2523 | || MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER) | |
2524 | return 1; | |
c4484b8f | 2525 | |
389fdba0 RH |
2526 | /* A read from read-only memory can't conflict with read-write memory. */ |
2527 | if (!writep && MEM_READONLY_P (mem)) | |
2528 | return 0; | |
55efb413 | 2529 | |
09e881c9 BE |
2530 | /* If we have MEMs refering to different address spaces (which can |
2531 | potentially overlap), we cannot easily tell from the addresses | |
2532 | whether the references overlap. */ | |
2533 | if (MEM_ADDR_SPACE (mem) != MEM_ADDR_SPACE (x)) | |
2534 | return 1; | |
2535 | ||
2147c71c L |
2536 | x_addr = XEXP (x, 0); |
2537 | mem_addr = XEXP (mem, 0); | |
2538 | if (!((GET_CODE (x_addr) == VALUE | |
2539 | && GET_CODE (mem_addr) != VALUE | |
2540 | && reg_mentioned_p (x_addr, mem_addr)) | |
2541 | || (GET_CODE (x_addr) != VALUE | |
2542 | && GET_CODE (mem_addr) == VALUE | |
2543 | && reg_mentioned_p (mem_addr, x_addr)))) | |
2544 | { | |
2545 | x_addr = get_addr (x_addr); | |
2546 | mem_addr = get_addr (mem_addr); | |
2547 | } | |
55efb413 | 2548 | |
49982682 JW |
2549 | if (! writep) |
2550 | { | |
55efb413 | 2551 | base = find_base_term (mem_addr); |
49982682 JW |
2552 | if (base && (GET_CODE (base) == LABEL_REF |
2553 | || (GET_CODE (base) == SYMBOL_REF | |
2554 | && CONSTANT_POOL_ADDRESS_P (base)))) | |
2555 | return 0; | |
2556 | } | |
2557 | ||
eab5c70a BS |
2558 | if (! base_alias_check (x_addr, mem_addr, GET_MODE (x), |
2559 | GET_MODE (mem))) | |
41472af8 MM |
2560 | return 0; |
2561 | ||
eab5c70a BS |
2562 | x_addr = canon_rtx (x_addr); |
2563 | mem_addr = canon_rtx (mem_addr); | |
6e73e666 | 2564 | |
f47e08d9 RG |
2565 | if ((ret = memrefs_conflict_p (SIZE_FOR_MODE (mem), mem_addr, |
2566 | SIZE_FOR_MODE (x), x_addr, 0)) != -1) | |
2567 | return ret; | |
2568 | ||
c6ea834c | 2569 | if (nonoverlapping_memrefs_p (x, mem, false)) |
c6df88cb MM |
2570 | return 0; |
2571 | ||
ca7fd9cd | 2572 | fixed_scalar |
eab5c70a BS |
2573 | = fixed_scalar_and_varying_struct_p (mem, x, mem_addr, x_addr, |
2574 | rtx_addr_varies_p); | |
2575 | ||
55b34b5f RG |
2576 | if ((fixed_scalar == mem && !aliases_everything_p (x)) |
2577 | || (fixed_scalar == x && !aliases_everything_p (mem))) | |
2578 | return 0; | |
2579 | ||
2580 | return rtx_refs_may_alias_p (x, mem, false); | |
c6df88cb MM |
2581 | } |
2582 | ||
2583 | /* Anti dependence: X is written after read in MEM takes place. */ | |
2584 | ||
2585 | int | |
4f588890 | 2586 | anti_dependence (const_rtx mem, const_rtx x) |
c6df88cb | 2587 | { |
389fdba0 | 2588 | return write_dependence_p (mem, x, /*writep=*/0); |
9ae8ffe7 JL |
2589 | } |
2590 | ||
2591 | /* Output dependence: X is written after store in MEM takes place. */ | |
2592 | ||
2593 | int | |
4f588890 | 2594 | output_dependence (const_rtx mem, const_rtx x) |
9ae8ffe7 | 2595 | { |
389fdba0 | 2596 | return write_dependence_p (mem, x, /*writep=*/1); |
9ae8ffe7 | 2597 | } |
c14b9960 | 2598 | \f |
6e73e666 | 2599 | |
c6ea834c BM |
2600 | |
2601 | /* Check whether X may be aliased with MEM. Don't do offset-based | |
2602 | memory disambiguation & TBAA. */ | |
2603 | int | |
2604 | may_alias_p (const_rtx mem, const_rtx x) | |
2605 | { | |
2606 | rtx x_addr, mem_addr; | |
c6ea834c BM |
2607 | |
2608 | if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) | |
2609 | return 1; | |
2610 | ||
2611 | /* ??? In true_dependence we also allow BLKmode to alias anything. */ | |
2612 | if (GET_MODE (mem) == BLKmode || GET_MODE (x) == BLKmode) | |
2613 | return 1; | |
2614 | ||
2615 | if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER | |
2616 | || MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER) | |
2617 | return 1; | |
2618 | ||
2619 | /* Read-only memory is by definition never modified, and therefore can't | |
2620 | conflict with anything. We don't expect to find read-only set on MEM, | |
2621 | but stupid user tricks can produce them, so don't die. */ | |
2622 | if (MEM_READONLY_P (x)) | |
2623 | return 0; | |
2624 | ||
2625 | /* If we have MEMs refering to different address spaces (which can | |
2626 | potentially overlap), we cannot easily tell from the addresses | |
2627 | whether the references overlap. */ | |
2628 | if (MEM_ADDR_SPACE (mem) != MEM_ADDR_SPACE (x)) | |
2629 | return 1; | |
2630 | ||
2631 | x_addr = XEXP (x, 0); | |
2632 | mem_addr = XEXP (mem, 0); | |
2633 | if (!((GET_CODE (x_addr) == VALUE | |
2634 | && GET_CODE (mem_addr) != VALUE | |
2635 | && reg_mentioned_p (x_addr, mem_addr)) | |
2636 | || (GET_CODE (x_addr) != VALUE | |
2637 | && GET_CODE (mem_addr) == VALUE | |
2638 | && reg_mentioned_p (mem_addr, x_addr)))) | |
2639 | { | |
2640 | x_addr = get_addr (x_addr); | |
2641 | mem_addr = get_addr (mem_addr); | |
2642 | } | |
2643 | ||
2644 | if (! base_alias_check (x_addr, mem_addr, GET_MODE (x), GET_MODE (mem_addr))) | |
2645 | return 0; | |
2646 | ||
2647 | x_addr = canon_rtx (x_addr); | |
2648 | mem_addr = canon_rtx (mem_addr); | |
2649 | ||
2650 | if (nonoverlapping_memrefs_p (mem, x, true)) | |
2651 | return 0; | |
2652 | ||
2653 | if (aliases_everything_p (x)) | |
2654 | return 1; | |
2655 | ||
2656 | /* We cannot use aliases_everything_p to test MEM, since we must look | |
2657 | at MEM_ADDR, rather than XEXP (mem, 0). */ | |
2658 | if (GET_MODE (mem) == QImode || GET_CODE (mem_addr) == AND) | |
2659 | return 1; | |
2660 | ||
2661 | if (fixed_scalar_and_varying_struct_p (mem, x, mem_addr, x_addr, | |
2662 | rtx_addr_varies_p)) | |
2663 | return 0; | |
2664 | ||
2665 | /* TBAA not valid for loop_invarint */ | |
2666 | return rtx_refs_may_alias_p (x, mem, false); | |
2667 | } | |
2668 | ||
6e73e666 | 2669 | void |
b5deb7b6 | 2670 | init_alias_target (void) |
6e73e666 | 2671 | { |
b3694847 | 2672 | int i; |
6e73e666 | 2673 | |
b5deb7b6 SL |
2674 | memset (static_reg_base_value, 0, sizeof static_reg_base_value); |
2675 | ||
6e73e666 JC |
2676 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) |
2677 | /* Check whether this register can hold an incoming pointer | |
2678 | argument. FUNCTION_ARG_REGNO_P tests outgoing register | |
ec5c56db | 2679 | numbers, so translate if necessary due to register windows. */ |
6e73e666 JC |
2680 | if (FUNCTION_ARG_REGNO_P (OUTGOING_REGNO (i)) |
2681 | && HARD_REGNO_MODE_OK (i, Pmode)) | |
bf1660a6 JL |
2682 | static_reg_base_value[i] |
2683 | = gen_rtx_ADDRESS (VOIDmode, gen_rtx_REG (Pmode, i)); | |
2684 | ||
bf1660a6 JL |
2685 | static_reg_base_value[STACK_POINTER_REGNUM] |
2686 | = gen_rtx_ADDRESS (Pmode, stack_pointer_rtx); | |
2687 | static_reg_base_value[ARG_POINTER_REGNUM] | |
2688 | = gen_rtx_ADDRESS (Pmode, arg_pointer_rtx); | |
2689 | static_reg_base_value[FRAME_POINTER_REGNUM] | |
2690 | = gen_rtx_ADDRESS (Pmode, frame_pointer_rtx); | |
2691 | #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM | |
2692 | static_reg_base_value[HARD_FRAME_POINTER_REGNUM] | |
2693 | = gen_rtx_ADDRESS (Pmode, hard_frame_pointer_rtx); | |
2694 | #endif | |
2695 | } | |
2696 | ||
7b52eede JH |
2697 | /* Set MEMORY_MODIFIED when X modifies DATA (that is assumed |
2698 | to be memory reference. */ | |
2699 | static bool memory_modified; | |
2700 | static void | |
aa317c97 | 2701 | memory_modified_1 (rtx x, const_rtx pat ATTRIBUTE_UNUSED, void *data) |
7b52eede | 2702 | { |
3c0cb5de | 2703 | if (MEM_P (x)) |
7b52eede | 2704 | { |
9678086d | 2705 | if (anti_dependence (x, (const_rtx)data) || output_dependence (x, (const_rtx)data)) |
7b52eede JH |
2706 | memory_modified = true; |
2707 | } | |
2708 | } | |
2709 | ||
2710 | ||
2711 | /* Return true when INSN possibly modify memory contents of MEM | |
454ff5cb | 2712 | (i.e. address can be modified). */ |
7b52eede | 2713 | bool |
9678086d | 2714 | memory_modified_in_insn_p (const_rtx mem, const_rtx insn) |
7b52eede JH |
2715 | { |
2716 | if (!INSN_P (insn)) | |
2717 | return false; | |
2718 | memory_modified = false; | |
aa317c97 | 2719 | note_stores (PATTERN (insn), memory_modified_1, CONST_CAST_RTX(mem)); |
7b52eede JH |
2720 | return memory_modified; |
2721 | } | |
2722 | ||
c13e8210 MM |
2723 | /* Initialize the aliasing machinery. Initialize the REG_KNOWN_VALUE |
2724 | array. */ | |
2725 | ||
9ae8ffe7 | 2726 | void |
4682ae04 | 2727 | init_alias_analysis (void) |
9ae8ffe7 | 2728 | { |
c582d54a | 2729 | unsigned int maxreg = max_reg_num (); |
ea64ef27 | 2730 | int changed, pass; |
b3694847 SS |
2731 | int i; |
2732 | unsigned int ui; | |
2733 | rtx insn; | |
9ae8ffe7 | 2734 | |
0d446150 JH |
2735 | timevar_push (TV_ALIAS_ANALYSIS); |
2736 | ||
bb1acb3e | 2737 | reg_known_value_size = maxreg - FIRST_PSEUDO_REGISTER; |
a9429e29 | 2738 | reg_known_value = ggc_alloc_cleared_vec_rtx (reg_known_value_size); |
f883e0a7 | 2739 | reg_known_equiv_p = XCNEWVEC (bool, reg_known_value_size); |
9ae8ffe7 | 2740 | |
08c79682 | 2741 | /* If we have memory allocated from the previous run, use it. */ |
c582d54a | 2742 | if (old_reg_base_value) |
08c79682 KH |
2743 | reg_base_value = old_reg_base_value; |
2744 | ||
2745 | if (reg_base_value) | |
2746 | VEC_truncate (rtx, reg_base_value, 0); | |
2747 | ||
a590ac65 | 2748 | VEC_safe_grow_cleared (rtx, gc, reg_base_value, maxreg); |
ac606739 | 2749 | |
5ed6ace5 MD |
2750 | new_reg_base_value = XNEWVEC (rtx, maxreg); |
2751 | reg_seen = XNEWVEC (char, maxreg); | |
ec907dd8 JL |
2752 | |
2753 | /* The basic idea is that each pass through this loop will use the | |
2754 | "constant" information from the previous pass to propagate alias | |
2755 | information through another level of assignments. | |
2756 | ||
2757 | This could get expensive if the assignment chains are long. Maybe | |
2758 | we should throttle the number of iterations, possibly based on | |
6e73e666 | 2759 | the optimization level or flag_expensive_optimizations. |
ec907dd8 JL |
2760 | |
2761 | We could propagate more information in the first pass by making use | |
6fb5fa3c | 2762 | of DF_REG_DEF_COUNT to determine immediately that the alias information |
ea64ef27 JL |
2763 | for a pseudo is "constant". |
2764 | ||
2765 | A program with an uninitialized variable can cause an infinite loop | |
2766 | here. Instead of doing a full dataflow analysis to detect such problems | |
2767 | we just cap the number of iterations for the loop. | |
2768 | ||
2769 | The state of the arrays for the set chain in question does not matter | |
2770 | since the program has undefined behavior. */ | |
6e73e666 | 2771 | |
ea64ef27 | 2772 | pass = 0; |
6e73e666 | 2773 | do |
ec907dd8 JL |
2774 | { |
2775 | /* Assume nothing will change this iteration of the loop. */ | |
2776 | changed = 0; | |
2777 | ||
ec907dd8 JL |
2778 | /* We want to assign the same IDs each iteration of this loop, so |
2779 | start counting from zero each iteration of the loop. */ | |
2780 | unique_id = 0; | |
2781 | ||
f5143c46 | 2782 | /* We're at the start of the function each iteration through the |
ec907dd8 | 2783 | loop, so we're copying arguments. */ |
83bbd9b6 | 2784 | copying_arguments = true; |
9ae8ffe7 | 2785 | |
6e73e666 | 2786 | /* Wipe the potential alias information clean for this pass. */ |
c582d54a | 2787 | memset (new_reg_base_value, 0, maxreg * sizeof (rtx)); |
8072f69c | 2788 | |
6e73e666 | 2789 | /* Wipe the reg_seen array clean. */ |
c582d54a | 2790 | memset (reg_seen, 0, maxreg); |
9ae8ffe7 | 2791 | |
6e73e666 JC |
2792 | /* Mark all hard registers which may contain an address. |
2793 | The stack, frame and argument pointers may contain an address. | |
2794 | An argument register which can hold a Pmode value may contain | |
2795 | an address even if it is not in BASE_REGS. | |
8072f69c | 2796 | |
6e73e666 JC |
2797 | The address expression is VOIDmode for an argument and |
2798 | Pmode for other registers. */ | |
2799 | ||
7f243674 JL |
2800 | memcpy (new_reg_base_value, static_reg_base_value, |
2801 | FIRST_PSEUDO_REGISTER * sizeof (rtx)); | |
6e73e666 | 2802 | |
ec907dd8 JL |
2803 | /* Walk the insns adding values to the new_reg_base_value array. */ |
2804 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) | |
9ae8ffe7 | 2805 | { |
2c3c49de | 2806 | if (INSN_P (insn)) |
ec907dd8 | 2807 | { |
6e73e666 | 2808 | rtx note, set; |
efc9bd41 RK |
2809 | |
2810 | #if defined (HAVE_prologue) || defined (HAVE_epilogue) | |
f5143c46 | 2811 | /* The prologue/epilogue insns are not threaded onto the |
657959ca JL |
2812 | insn chain until after reload has completed. Thus, |
2813 | there is no sense wasting time checking if INSN is in | |
2814 | the prologue/epilogue until after reload has completed. */ | |
2815 | if (reload_completed | |
2816 | && prologue_epilogue_contains (insn)) | |
efc9bd41 RK |
2817 | continue; |
2818 | #endif | |
2819 | ||
ec907dd8 | 2820 | /* If this insn has a noalias note, process it, Otherwise, |
c22cacf3 MS |
2821 | scan for sets. A simple set will have no side effects |
2822 | which could change the base value of any other register. */ | |
6e73e666 | 2823 | |
ec907dd8 | 2824 | if (GET_CODE (PATTERN (insn)) == SET |
efc9bd41 RK |
2825 | && REG_NOTES (insn) != 0 |
2826 | && find_reg_note (insn, REG_NOALIAS, NULL_RTX)) | |
84832317 | 2827 | record_set (SET_DEST (PATTERN (insn)), NULL_RTX, NULL); |
ec907dd8 | 2828 | else |
84832317 | 2829 | note_stores (PATTERN (insn), record_set, NULL); |
6e73e666 JC |
2830 | |
2831 | set = single_set (insn); | |
2832 | ||
2833 | if (set != 0 | |
f8cfc6aa | 2834 | && REG_P (SET_DEST (set)) |
fb6754f0 | 2835 | && REGNO (SET_DEST (set)) >= FIRST_PSEUDO_REGISTER) |
6e73e666 | 2836 | { |
fb6754f0 | 2837 | unsigned int regno = REGNO (SET_DEST (set)); |
713f41f9 | 2838 | rtx src = SET_SRC (set); |
bb1acb3e | 2839 | rtx t; |
713f41f9 | 2840 | |
a31830a7 SB |
2841 | note = find_reg_equal_equiv_note (insn); |
2842 | if (note && REG_NOTE_KIND (note) == REG_EQUAL | |
6fb5fa3c | 2843 | && DF_REG_DEF_COUNT (regno) != 1) |
a31830a7 SB |
2844 | note = NULL_RTX; |
2845 | ||
2846 | if (note != NULL_RTX | |
713f41f9 | 2847 | && GET_CODE (XEXP (note, 0)) != EXPR_LIST |
bb2cf916 | 2848 | && ! rtx_varies_p (XEXP (note, 0), 1) |
bb1acb3e RH |
2849 | && ! reg_overlap_mentioned_p (SET_DEST (set), |
2850 | XEXP (note, 0))) | |
713f41f9 | 2851 | { |
bb1acb3e RH |
2852 | set_reg_known_value (regno, XEXP (note, 0)); |
2853 | set_reg_known_equiv_p (regno, | |
2854 | REG_NOTE_KIND (note) == REG_EQUIV); | |
713f41f9 | 2855 | } |
6fb5fa3c | 2856 | else if (DF_REG_DEF_COUNT (regno) == 1 |
713f41f9 | 2857 | && GET_CODE (src) == PLUS |
f8cfc6aa | 2858 | && REG_P (XEXP (src, 0)) |
bb1acb3e | 2859 | && (t = get_reg_known_value (REGNO (XEXP (src, 0)))) |
481683e1 | 2860 | && CONST_INT_P (XEXP (src, 1))) |
713f41f9 | 2861 | { |
bb1acb3e RH |
2862 | t = plus_constant (t, INTVAL (XEXP (src, 1))); |
2863 | set_reg_known_value (regno, t); | |
2864 | set_reg_known_equiv_p (regno, 0); | |
713f41f9 | 2865 | } |
6fb5fa3c | 2866 | else if (DF_REG_DEF_COUNT (regno) == 1 |
713f41f9 BS |
2867 | && ! rtx_varies_p (src, 1)) |
2868 | { | |
bb1acb3e RH |
2869 | set_reg_known_value (regno, src); |
2870 | set_reg_known_equiv_p (regno, 0); | |
713f41f9 | 2871 | } |
6e73e666 | 2872 | } |
ec907dd8 | 2873 | } |
4b4bf941 | 2874 | else if (NOTE_P (insn) |
a38e7aa5 | 2875 | && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG) |
83bbd9b6 | 2876 | copying_arguments = false; |
6e73e666 | 2877 | } |
ec907dd8 | 2878 | |
6e73e666 | 2879 | /* Now propagate values from new_reg_base_value to reg_base_value. */ |
62e5bf5d | 2880 | gcc_assert (maxreg == (unsigned int) max_reg_num ()); |
c22cacf3 | 2881 | |
c582d54a | 2882 | for (ui = 0; ui < maxreg; ui++) |
6e73e666 | 2883 | { |
e51712db | 2884 | if (new_reg_base_value[ui] |
08c79682 | 2885 | && new_reg_base_value[ui] != VEC_index (rtx, reg_base_value, ui) |
c582d54a | 2886 | && ! rtx_equal_p (new_reg_base_value[ui], |
08c79682 | 2887 | VEC_index (rtx, reg_base_value, ui))) |
ec907dd8 | 2888 | { |
08c79682 | 2889 | VEC_replace (rtx, reg_base_value, ui, new_reg_base_value[ui]); |
6e73e666 | 2890 | changed = 1; |
ec907dd8 | 2891 | } |
9ae8ffe7 | 2892 | } |
9ae8ffe7 | 2893 | } |
6e73e666 | 2894 | while (changed && ++pass < MAX_ALIAS_LOOP_PASSES); |
9ae8ffe7 JL |
2895 | |
2896 | /* Fill in the remaining entries. */ | |
bb1acb3e | 2897 | for (i = 0; i < (int)reg_known_value_size; i++) |
9ae8ffe7 | 2898 | if (reg_known_value[i] == 0) |
bb1acb3e | 2899 | reg_known_value[i] = regno_reg_rtx[i + FIRST_PSEUDO_REGISTER]; |
9ae8ffe7 | 2900 | |
e05e2395 MM |
2901 | /* Clean up. */ |
2902 | free (new_reg_base_value); | |
ec907dd8 | 2903 | new_reg_base_value = 0; |
e05e2395 | 2904 | free (reg_seen); |
9ae8ffe7 | 2905 | reg_seen = 0; |
0d446150 | 2906 | timevar_pop (TV_ALIAS_ANALYSIS); |
9ae8ffe7 JL |
2907 | } |
2908 | ||
2909 | void | |
4682ae04 | 2910 | end_alias_analysis (void) |
9ae8ffe7 | 2911 | { |
c582d54a | 2912 | old_reg_base_value = reg_base_value; |
bb1acb3e | 2913 | ggc_free (reg_known_value); |
9ae8ffe7 | 2914 | reg_known_value = 0; |
ac606739 | 2915 | reg_known_value_size = 0; |
bb1acb3e | 2916 | free (reg_known_equiv_p); |
e05e2395 | 2917 | reg_known_equiv_p = 0; |
9ae8ffe7 | 2918 | } |
e2500fed GK |
2919 | |
2920 | #include "gt-alias.h" |