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9ae8ffe7 | 1 | /* Alias analysis for GNU C |
d9221e01 | 2 | Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 |
1afdf91c | 3 | 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 | |
10 | Software Foundation; either version 2, or (at your option) any later | |
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 | |
1322177d LB |
19 | along with GCC; see the file COPYING. If not, write to the Free |
20 | Software Foundation, 59 Temple Place - Suite 330, Boston, MA | |
21 | 02111-1307, USA. */ | |
9ae8ffe7 JL |
22 | |
23 | #include "config.h" | |
670ee920 | 24 | #include "system.h" |
4977bab6 ZW |
25 | #include "coretypes.h" |
26 | #include "tm.h" | |
9ae8ffe7 | 27 | #include "rtl.h" |
7790df19 | 28 | #include "tree.h" |
6baf1cc8 | 29 | #include "tm_p.h" |
49ad7cfa | 30 | #include "function.h" |
78528714 JQ |
31 | #include "alias.h" |
32 | #include "emit-rtl.h" | |
9ae8ffe7 JL |
33 | #include "regs.h" |
34 | #include "hard-reg-set.h" | |
e004f2f7 | 35 | #include "basic-block.h" |
9ae8ffe7 | 36 | #include "flags.h" |
264fac34 | 37 | #include "output.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" |
9ddb66ca | 46 | #include "varray.h" |
3932261a MM |
47 | |
48 | /* The alias sets assigned to MEMs assist the back-end in determining | |
49 | which MEMs can alias which other MEMs. In general, two MEMs in | |
ac3d9668 RK |
50 | different alias sets cannot alias each other, with one important |
51 | exception. Consider something like: | |
3932261a | 52 | |
01d28c3f | 53 | struct S { int i; double d; }; |
3932261a MM |
54 | |
55 | a store to an `S' can alias something of either type `int' or type | |
56 | `double'. (However, a store to an `int' cannot alias a `double' | |
57 | and vice versa.) We indicate this via a tree structure that looks | |
58 | like: | |
59 | struct S | |
60 | / \ | |
61 | / \ | |
62 | |/_ _\| | |
63 | int double | |
64 | ||
ac3d9668 RK |
65 | (The arrows are directed and point downwards.) |
66 | In this situation we say the alias set for `struct S' is the | |
67 | `superset' and that those for `int' and `double' are `subsets'. | |
68 | ||
3bdf5ad1 RK |
69 | To see whether two alias sets can point to the same memory, we must |
70 | see if either alias set is a subset of the other. We need not trace | |
95bd1dd7 | 71 | past immediate descendants, however, since we propagate all |
3bdf5ad1 | 72 | grandchildren up one level. |
3932261a MM |
73 | |
74 | Alias set zero is implicitly a superset of all other alias sets. | |
75 | However, this is no actual entry for alias set zero. It is an | |
76 | error to attempt to explicitly construct a subset of zero. */ | |
77 | ||
b604074c | 78 | struct alias_set_entry GTY(()) |
d4b60170 | 79 | { |
3932261a | 80 | /* The alias set number, as stored in MEM_ALIAS_SET. */ |
3bdf5ad1 | 81 | HOST_WIDE_INT alias_set; |
3932261a MM |
82 | |
83 | /* The children of the alias set. These are not just the immediate | |
95bd1dd7 | 84 | children, but, in fact, all descendants. So, if we have: |
3932261a | 85 | |
ca7fd9cd | 86 | struct T { struct S s; float f; } |
3932261a MM |
87 | |
88 | continuing our example above, the children here will be all of | |
89 | `int', `double', `float', and `struct S'. */ | |
b604074c | 90 | splay_tree GTY((param1_is (int), param2_is (int))) children; |
2bf105ab RK |
91 | |
92 | /* Nonzero if would have a child of zero: this effectively makes this | |
93 | alias set the same as alias set zero. */ | |
94 | int has_zero_child; | |
b604074c GK |
95 | }; |
96 | typedef struct alias_set_entry *alias_set_entry; | |
9ae8ffe7 | 97 | |
4682ae04 AJ |
98 | static int rtx_equal_for_memref_p (rtx, rtx); |
99 | static rtx find_symbolic_term (rtx); | |
4682ae04 AJ |
100 | static int memrefs_conflict_p (int, rtx, int, rtx, HOST_WIDE_INT); |
101 | static void record_set (rtx, rtx, void *); | |
102 | static int base_alias_check (rtx, rtx, enum machine_mode, | |
103 | enum machine_mode); | |
104 | static rtx find_base_value (rtx); | |
105 | static int mems_in_disjoint_alias_sets_p (rtx, rtx); | |
106 | static int insert_subset_children (splay_tree_node, void*); | |
107 | static tree find_base_decl (tree); | |
108 | static alias_set_entry get_alias_set_entry (HOST_WIDE_INT); | |
109 | static rtx fixed_scalar_and_varying_struct_p (rtx, rtx, rtx, rtx, | |
110 | int (*) (rtx, int)); | |
111 | static int aliases_everything_p (rtx); | |
112 | static bool nonoverlapping_component_refs_p (tree, tree); | |
113 | static tree decl_for_component_ref (tree); | |
114 | static rtx adjust_offset_for_component_ref (tree, rtx); | |
115 | static int nonoverlapping_memrefs_p (rtx, rtx); | |
389fdba0 | 116 | static int write_dependence_p (rtx, rtx, int); |
4682ae04 AJ |
117 | |
118 | static int nonlocal_mentioned_p_1 (rtx *, void *); | |
119 | static int nonlocal_mentioned_p (rtx); | |
120 | static int nonlocal_referenced_p_1 (rtx *, void *); | |
121 | static int nonlocal_referenced_p (rtx); | |
122 | static int nonlocal_set_p_1 (rtx *, void *); | |
123 | static int nonlocal_set_p (rtx); | |
124 | static void memory_modified_1 (rtx, rtx, void *); | |
04e2b4d3 | 125 | static void record_alias_subset (HOST_WIDE_INT, HOST_WIDE_INT); |
9ae8ffe7 JL |
126 | |
127 | /* Set up all info needed to perform alias analysis on memory references. */ | |
128 | ||
d4b60170 | 129 | /* Returns the size in bytes of the mode of X. */ |
9ae8ffe7 JL |
130 | #define SIZE_FOR_MODE(X) (GET_MODE_SIZE (GET_MODE (X))) |
131 | ||
41472af8 | 132 | /* Returns nonzero if MEM1 and MEM2 do not alias because they are in |
264fac34 MM |
133 | different alias sets. We ignore alias sets in functions making use |
134 | of variable arguments because the va_arg macros on some systems are | |
135 | not legal ANSI C. */ | |
136 | #define DIFFERENT_ALIAS_SETS_P(MEM1, MEM2) \ | |
3932261a | 137 | mems_in_disjoint_alias_sets_p (MEM1, MEM2) |
41472af8 | 138 | |
ea64ef27 | 139 | /* Cap the number of passes we make over the insns propagating alias |
ac3d9668 | 140 | information through set chains. 10 is a completely arbitrary choice. */ |
ea64ef27 | 141 | #define MAX_ALIAS_LOOP_PASSES 10 |
ca7fd9cd | 142 | |
9ae8ffe7 JL |
143 | /* reg_base_value[N] gives an address to which register N is related. |
144 | If all sets after the first add or subtract to the current value | |
145 | or otherwise modify it so it does not point to a different top level | |
146 | object, reg_base_value[N] is equal to the address part of the source | |
2a2c8203 JC |
147 | of the first set. |
148 | ||
149 | A base address can be an ADDRESS, SYMBOL_REF, or LABEL_REF. ADDRESS | |
150 | expressions represent certain special values: function arguments and | |
ca7fd9cd | 151 | the stack, frame, and argument pointers. |
b3b5ad95 JL |
152 | |
153 | The contents of an ADDRESS is not normally used, the mode of the | |
154 | ADDRESS determines whether the ADDRESS is a function argument or some | |
155 | other special value. Pointer equality, not rtx_equal_p, determines whether | |
156 | two ADDRESS expressions refer to the same base address. | |
157 | ||
158 | The only use of the contents of an ADDRESS is for determining if the | |
159 | current function performs nonlocal memory memory references for the | |
160 | purposes of marking the function as a constant function. */ | |
2a2c8203 | 161 | |
c582d54a | 162 | static GTY(()) varray_type reg_base_value; |
ac606739 | 163 | static rtx *new_reg_base_value; |
c582d54a JH |
164 | |
165 | /* We preserve the copy of old array around to avoid amount of garbage | |
166 | produced. About 8% of garbage produced were attributed to this | |
167 | array. */ | |
1431042e | 168 | static GTY((deletable)) varray_type old_reg_base_value; |
d4b60170 | 169 | |
bf1660a6 JL |
170 | /* Static hunks of RTL used by the aliasing code; these are initialized |
171 | once per function to avoid unnecessary RTL allocations. */ | |
172 | static GTY (()) rtx static_reg_base_value[FIRST_PSEUDO_REGISTER]; | |
173 | ||
9ae8ffe7 | 174 | #define REG_BASE_VALUE(X) \ |
c582d54a JH |
175 | (reg_base_value && REGNO (X) < VARRAY_SIZE (reg_base_value) \ |
176 | ? VARRAY_RTX (reg_base_value, REGNO (X)) : 0) | |
9ae8ffe7 | 177 | |
de12be17 JC |
178 | /* Vector of known invariant relationships between registers. Set in |
179 | loop unrolling. Indexed by register number, if nonzero the value | |
180 | is an expression describing this register in terms of another. | |
181 | ||
182 | The length of this array is REG_BASE_VALUE_SIZE. | |
183 | ||
184 | Because this array contains only pseudo registers it has no effect | |
185 | after reload. */ | |
bb1acb3e | 186 | static GTY((length("alias_invariant_size"))) rtx *alias_invariant; |
133f7a77 | 187 | static GTY(()) unsigned int alias_invariant_size; |
de12be17 | 188 | |
c13e8210 | 189 | /* Vector indexed by N giving the initial (unchanging) value known for |
bb1acb3e RH |
190 | pseudo-register N. This array is initialized in init_alias_analysis, |
191 | and does not change until end_alias_analysis is called. */ | |
192 | static GTY((length("reg_known_value_size"))) rtx *reg_known_value; | |
9ae8ffe7 JL |
193 | |
194 | /* Indicates number of valid entries in reg_known_value. */ | |
bb1acb3e | 195 | static GTY(()) unsigned int reg_known_value_size; |
9ae8ffe7 JL |
196 | |
197 | /* Vector recording for each reg_known_value whether it is due to a | |
198 | REG_EQUIV note. Future passes (viz., reload) may replace the | |
199 | pseudo with the equivalent expression and so we account for the | |
ac3d9668 RK |
200 | dependences that would be introduced if that happens. |
201 | ||
202 | The REG_EQUIV notes created in assign_parms may mention the arg | |
203 | pointer, and there are explicit insns in the RTL that modify the | |
204 | arg pointer. Thus we must ensure that such insns don't get | |
205 | scheduled across each other because that would invalidate the | |
206 | REG_EQUIV notes. One could argue that the REG_EQUIV notes are | |
207 | wrong, but solving the problem in the scheduler will likely give | |
208 | better code, so we do it here. */ | |
bb1acb3e | 209 | static bool *reg_known_equiv_p; |
9ae8ffe7 | 210 | |
2a2c8203 JC |
211 | /* True when scanning insns from the start of the rtl to the |
212 | NOTE_INSN_FUNCTION_BEG note. */ | |
83bbd9b6 | 213 | static bool copying_arguments; |
9ae8ffe7 | 214 | |
3932261a | 215 | /* The splay-tree used to store the various alias set entries. */ |
b604074c | 216 | static GTY ((param_is (struct alias_set_entry))) varray_type alias_sets; |
ac3d9668 | 217 | \f |
3932261a MM |
218 | /* Returns a pointer to the alias set entry for ALIAS_SET, if there is |
219 | such an entry, or NULL otherwise. */ | |
220 | ||
9ddb66ca | 221 | static inline alias_set_entry |
4682ae04 | 222 | get_alias_set_entry (HOST_WIDE_INT alias_set) |
3932261a | 223 | { |
9ddb66ca | 224 | return (alias_set_entry)VARRAY_GENERIC_PTR (alias_sets, alias_set); |
3932261a MM |
225 | } |
226 | ||
ac3d9668 RK |
227 | /* Returns nonzero if the alias sets for MEM1 and MEM2 are such that |
228 | the two MEMs cannot alias each other. */ | |
3932261a | 229 | |
9ddb66ca | 230 | static inline int |
4682ae04 | 231 | mems_in_disjoint_alias_sets_p (rtx mem1, rtx mem2) |
3932261a | 232 | { |
3932261a MM |
233 | /* Perform a basic sanity check. Namely, that there are no alias sets |
234 | if we're not using strict aliasing. This helps to catch bugs | |
235 | whereby someone uses PUT_CODE, but doesn't clear MEM_ALIAS_SET, or | |
236 | where a MEM is allocated in some way other than by the use of | |
237 | gen_rtx_MEM, and the MEM_ALIAS_SET is not cleared. If we begin to | |
238 | use alias sets to indicate that spilled registers cannot alias each | |
239 | other, we might need to remove this check. */ | |
298e6adc NS |
240 | gcc_assert (flag_strict_aliasing |
241 | || (!MEM_ALIAS_SET (mem1) && !MEM_ALIAS_SET (mem2))); | |
3932261a | 242 | |
1da68f56 RK |
243 | return ! alias_sets_conflict_p (MEM_ALIAS_SET (mem1), MEM_ALIAS_SET (mem2)); |
244 | } | |
3932261a | 245 | |
1da68f56 RK |
246 | /* Insert the NODE into the splay tree given by DATA. Used by |
247 | record_alias_subset via splay_tree_foreach. */ | |
248 | ||
249 | static int | |
4682ae04 | 250 | insert_subset_children (splay_tree_node node, void *data) |
1da68f56 RK |
251 | { |
252 | splay_tree_insert ((splay_tree) data, node->key, node->value); | |
253 | ||
254 | return 0; | |
255 | } | |
256 | ||
257 | /* Return 1 if the two specified alias sets may conflict. */ | |
258 | ||
259 | int | |
4682ae04 | 260 | alias_sets_conflict_p (HOST_WIDE_INT set1, HOST_WIDE_INT set2) |
1da68f56 RK |
261 | { |
262 | alias_set_entry ase; | |
263 | ||
264 | /* If have no alias set information for one of the operands, we have | |
265 | to assume it can alias anything. */ | |
266 | if (set1 == 0 || set2 == 0 | |
267 | /* If the two alias sets are the same, they may alias. */ | |
268 | || set1 == set2) | |
269 | return 1; | |
3932261a | 270 | |
3bdf5ad1 | 271 | /* See if the first alias set is a subset of the second. */ |
1da68f56 | 272 | ase = get_alias_set_entry (set1); |
2bf105ab RK |
273 | if (ase != 0 |
274 | && (ase->has_zero_child | |
275 | || splay_tree_lookup (ase->children, | |
1da68f56 RK |
276 | (splay_tree_key) set2))) |
277 | return 1; | |
3932261a MM |
278 | |
279 | /* Now do the same, but with the alias sets reversed. */ | |
1da68f56 | 280 | ase = get_alias_set_entry (set2); |
2bf105ab RK |
281 | if (ase != 0 |
282 | && (ase->has_zero_child | |
283 | || splay_tree_lookup (ase->children, | |
1da68f56 RK |
284 | (splay_tree_key) set1))) |
285 | return 1; | |
3932261a | 286 | |
1da68f56 | 287 | /* The two alias sets are distinct and neither one is the |
3932261a | 288 | child of the other. Therefore, they cannot alias. */ |
1da68f56 | 289 | return 0; |
3932261a | 290 | } |
5399d643 JW |
291 | |
292 | /* Return 1 if the two specified alias sets might conflict, or if any subtype | |
293 | of these alias sets might conflict. */ | |
294 | ||
295 | int | |
296 | alias_sets_might_conflict_p (HOST_WIDE_INT set1, HOST_WIDE_INT set2) | |
297 | { | |
298 | if (set1 == 0 || set2 == 0 || set1 == set2) | |
299 | return 1; | |
300 | ||
301 | return 0; | |
302 | } | |
303 | ||
3bdf5ad1 | 304 | \f |
1da68f56 RK |
305 | /* Return 1 if any MEM object of type T1 will always conflict (using the |
306 | dependency routines in this file) with any MEM object of type T2. | |
307 | This is used when allocating temporary storage. If T1 and/or T2 are | |
308 | NULL_TREE, it means we know nothing about the storage. */ | |
309 | ||
310 | int | |
4682ae04 | 311 | objects_must_conflict_p (tree t1, tree t2) |
1da68f56 | 312 | { |
82d610ec RK |
313 | HOST_WIDE_INT set1, set2; |
314 | ||
e8ea2809 RK |
315 | /* If neither has a type specified, we don't know if they'll conflict |
316 | because we may be using them to store objects of various types, for | |
317 | example the argument and local variables areas of inlined functions. */ | |
981a4c34 | 318 | if (t1 == 0 && t2 == 0) |
e8ea2809 RK |
319 | return 0; |
320 | ||
1da68f56 RK |
321 | /* If they are the same type, they must conflict. */ |
322 | if (t1 == t2 | |
323 | /* Likewise if both are volatile. */ | |
324 | || (t1 != 0 && TYPE_VOLATILE (t1) && t2 != 0 && TYPE_VOLATILE (t2))) | |
325 | return 1; | |
326 | ||
82d610ec RK |
327 | set1 = t1 ? get_alias_set (t1) : 0; |
328 | set2 = t2 ? get_alias_set (t2) : 0; | |
1da68f56 | 329 | |
82d610ec RK |
330 | /* Otherwise they conflict if they have no alias set or the same. We |
331 | can't simply use alias_sets_conflict_p here, because we must make | |
332 | sure that every subtype of t1 will conflict with every subtype of | |
333 | t2 for which a pair of subobjects of these respective subtypes | |
334 | overlaps on the stack. */ | |
335 | return set1 == 0 || set2 == 0 || set1 == set2; | |
1da68f56 RK |
336 | } |
337 | \f | |
3bdf5ad1 RK |
338 | /* T is an expression with pointer type. Find the DECL on which this |
339 | expression is based. (For example, in `a[i]' this would be `a'.) | |
340 | If there is no such DECL, or a unique decl cannot be determined, | |
f5143c46 | 341 | NULL_TREE is returned. */ |
3bdf5ad1 RK |
342 | |
343 | static tree | |
4682ae04 | 344 | find_base_decl (tree t) |
3bdf5ad1 | 345 | { |
6615c446 | 346 | tree d0, d1; |
3bdf5ad1 RK |
347 | |
348 | if (t == 0 || t == error_mark_node || ! POINTER_TYPE_P (TREE_TYPE (t))) | |
349 | return 0; | |
350 | ||
351 | /* If this is a declaration, return it. */ | |
6615c446 | 352 | if (DECL_P (t)) |
3bdf5ad1 RK |
353 | return t; |
354 | ||
355 | /* Handle general expressions. It would be nice to deal with | |
356 | COMPONENT_REFs here. If we could tell that `a' and `b' were the | |
357 | same, then `a->f' and `b->f' are also the same. */ | |
358 | switch (TREE_CODE_CLASS (TREE_CODE (t))) | |
359 | { | |
6615c446 | 360 | case tcc_unary: |
3bdf5ad1 RK |
361 | return find_base_decl (TREE_OPERAND (t, 0)); |
362 | ||
6615c446 | 363 | case tcc_binary: |
3bdf5ad1 RK |
364 | /* Return 0 if found in neither or both are the same. */ |
365 | d0 = find_base_decl (TREE_OPERAND (t, 0)); | |
366 | d1 = find_base_decl (TREE_OPERAND (t, 1)); | |
367 | if (d0 == d1) | |
368 | return d0; | |
369 | else if (d0 == 0) | |
370 | return d1; | |
371 | else if (d1 == 0) | |
372 | return d0; | |
373 | else | |
374 | return 0; | |
375 | ||
3bdf5ad1 RK |
376 | default: |
377 | return 0; | |
378 | } | |
379 | } | |
380 | ||
6e24b709 RK |
381 | /* Return 1 if all the nested component references handled by |
382 | get_inner_reference in T are such that we can address the object in T. */ | |
383 | ||
10b76d73 | 384 | int |
4682ae04 | 385 | can_address_p (tree t) |
6e24b709 RK |
386 | { |
387 | /* If we're at the end, it is vacuously addressable. */ | |
388 | if (! handled_component_p (t)) | |
389 | return 1; | |
390 | ||
391 | /* Bitfields are never addressable. */ | |
392 | else if (TREE_CODE (t) == BIT_FIELD_REF) | |
393 | return 0; | |
394 | ||
8ac61af7 RK |
395 | /* Fields are addressable unless they are marked as nonaddressable or |
396 | the containing type has alias set 0. */ | |
6e24b709 RK |
397 | else if (TREE_CODE (t) == COMPONENT_REF |
398 | && ! DECL_NONADDRESSABLE_P (TREE_OPERAND (t, 1)) | |
8ac61af7 | 399 | && get_alias_set (TREE_TYPE (TREE_OPERAND (t, 0))) != 0 |
6e24b709 RK |
400 | && can_address_p (TREE_OPERAND (t, 0))) |
401 | return 1; | |
402 | ||
8ac61af7 | 403 | /* Likewise for arrays. */ |
b4e3fabb | 404 | else if ((TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF) |
6e24b709 | 405 | && ! TYPE_NONALIASED_COMPONENT (TREE_TYPE (TREE_OPERAND (t, 0))) |
8ac61af7 | 406 | && get_alias_set (TREE_TYPE (TREE_OPERAND (t, 0))) != 0 |
6e24b709 RK |
407 | && can_address_p (TREE_OPERAND (t, 0))) |
408 | return 1; | |
409 | ||
410 | return 0; | |
411 | } | |
412 | ||
3bdf5ad1 RK |
413 | /* Return the alias set for T, which may be either a type or an |
414 | expression. Call language-specific routine for help, if needed. */ | |
415 | ||
416 | HOST_WIDE_INT | |
4682ae04 | 417 | get_alias_set (tree t) |
3bdf5ad1 RK |
418 | { |
419 | HOST_WIDE_INT set; | |
3bdf5ad1 RK |
420 | |
421 | /* If we're not doing any alias analysis, just assume everything | |
422 | aliases everything else. Also return 0 if this or its type is | |
423 | an error. */ | |
424 | if (! flag_strict_aliasing || t == error_mark_node | |
425 | || (! TYPE_P (t) | |
426 | && (TREE_TYPE (t) == 0 || TREE_TYPE (t) == error_mark_node))) | |
427 | return 0; | |
428 | ||
429 | /* We can be passed either an expression or a type. This and the | |
f47e9b4e RK |
430 | language-specific routine may make mutually-recursive calls to each other |
431 | to figure out what to do. At each juncture, we see if this is a tree | |
432 | that the language may need to handle specially. First handle things that | |
738cc472 | 433 | aren't types. */ |
f824e5c3 | 434 | if (! TYPE_P (t)) |
3bdf5ad1 | 435 | { |
738cc472 | 436 | tree inner = t; |
738cc472 | 437 | |
8ac61af7 RK |
438 | /* Remove any nops, then give the language a chance to do |
439 | something with this tree before we look at it. */ | |
440 | STRIP_NOPS (t); | |
ae2bcd98 | 441 | set = lang_hooks.get_alias_set (t); |
8ac61af7 RK |
442 | if (set != -1) |
443 | return set; | |
444 | ||
738cc472 | 445 | /* First see if the actual object referenced is an INDIRECT_REF from a |
6fce44af RK |
446 | restrict-qualified pointer or a "void *". */ |
447 | while (handled_component_p (inner)) | |
738cc472 | 448 | { |
6fce44af | 449 | inner = TREE_OPERAND (inner, 0); |
8ac61af7 | 450 | STRIP_NOPS (inner); |
738cc472 RK |
451 | } |
452 | ||
453 | /* Check for accesses through restrict-qualified pointers. */ | |
1b096a0a | 454 | if (INDIRECT_REF_P (inner)) |
738cc472 RK |
455 | { |
456 | tree decl = find_base_decl (TREE_OPERAND (inner, 0)); | |
457 | ||
458 | if (decl && DECL_POINTER_ALIAS_SET_KNOWN_P (decl)) | |
459 | { | |
e5837c07 | 460 | /* If we haven't computed the actual alias set, do it now. */ |
738cc472 RK |
461 | if (DECL_POINTER_ALIAS_SET (decl) == -2) |
462 | { | |
4f430fb9 MM |
463 | tree pointed_to_type = TREE_TYPE (TREE_TYPE (decl)); |
464 | ||
738cc472 RK |
465 | /* No two restricted pointers can point at the same thing. |
466 | However, a restricted pointer can point at the same thing | |
467 | as an unrestricted pointer, if that unrestricted pointer | |
468 | is based on the restricted pointer. So, we make the | |
469 | alias set for the restricted pointer a subset of the | |
470 | alias set for the type pointed to by the type of the | |
471 | decl. */ | |
472 | HOST_WIDE_INT pointed_to_alias_set | |
4f430fb9 | 473 | = get_alias_set (pointed_to_type); |
738cc472 RK |
474 | |
475 | if (pointed_to_alias_set == 0) | |
476 | /* It's not legal to make a subset of alias set zero. */ | |
e7844ffb | 477 | DECL_POINTER_ALIAS_SET (decl) = 0; |
4f430fb9 MM |
478 | else if (AGGREGATE_TYPE_P (pointed_to_type)) |
479 | /* For an aggregate, we must treat the restricted | |
480 | pointer the same as an ordinary pointer. If we | |
481 | were to make the type pointed to by the | |
482 | restricted pointer a subset of the pointed-to | |
483 | type, then we would believe that other subsets | |
484 | of the pointed-to type (such as fields of that | |
485 | type) do not conflict with the type pointed to | |
471854f8 | 486 | by the restricted pointer. */ |
4f430fb9 MM |
487 | DECL_POINTER_ALIAS_SET (decl) |
488 | = pointed_to_alias_set; | |
738cc472 RK |
489 | else |
490 | { | |
491 | DECL_POINTER_ALIAS_SET (decl) = new_alias_set (); | |
ca7fd9cd KH |
492 | record_alias_subset (pointed_to_alias_set, |
493 | DECL_POINTER_ALIAS_SET (decl)); | |
738cc472 RK |
494 | } |
495 | } | |
496 | ||
497 | /* We use the alias set indicated in the declaration. */ | |
498 | return DECL_POINTER_ALIAS_SET (decl); | |
499 | } | |
500 | ||
501 | /* If we have an INDIRECT_REF via a void pointer, we don't | |
22421b79 RK |
502 | know anything about what that might alias. Likewise if the |
503 | pointer is marked that way. */ | |
504 | else if (TREE_CODE (TREE_TYPE (inner)) == VOID_TYPE | |
505 | || (TYPE_REF_CAN_ALIAS_ALL | |
506 | (TREE_TYPE (TREE_OPERAND (inner, 0))))) | |
738cc472 RK |
507 | return 0; |
508 | } | |
509 | ||
510 | /* Otherwise, pick up the outermost object that we could have a pointer | |
6fce44af RK |
511 | to, processing conversions as above. */ |
512 | while (handled_component_p (t) && ! can_address_p (t)) | |
f47e9b4e | 513 | { |
6fce44af | 514 | t = TREE_OPERAND (t, 0); |
8ac61af7 RK |
515 | STRIP_NOPS (t); |
516 | } | |
f824e5c3 | 517 | |
738cc472 RK |
518 | /* If we've already determined the alias set for a decl, just return |
519 | it. This is necessary for C++ anonymous unions, whose component | |
520 | variables don't look like union members (boo!). */ | |
5755cd38 | 521 | if (TREE_CODE (t) == VAR_DECL |
3c0cb5de | 522 | && DECL_RTL_SET_P (t) && MEM_P (DECL_RTL (t))) |
5755cd38 JM |
523 | return MEM_ALIAS_SET (DECL_RTL (t)); |
524 | ||
f824e5c3 RK |
525 | /* Now all we care about is the type. */ |
526 | t = TREE_TYPE (t); | |
3bdf5ad1 RK |
527 | } |
528 | ||
3bdf5ad1 RK |
529 | /* Variant qualifiers don't affect the alias set, so get the main |
530 | variant. If this is a type with a known alias set, return it. */ | |
531 | t = TYPE_MAIN_VARIANT (t); | |
738cc472 | 532 | if (TYPE_ALIAS_SET_KNOWN_P (t)) |
3bdf5ad1 RK |
533 | return TYPE_ALIAS_SET (t); |
534 | ||
535 | /* See if the language has special handling for this type. */ | |
ae2bcd98 | 536 | set = lang_hooks.get_alias_set (t); |
8ac61af7 | 537 | if (set != -1) |
738cc472 | 538 | return set; |
2bf105ab | 539 | |
3bdf5ad1 RK |
540 | /* There are no objects of FUNCTION_TYPE, so there's no point in |
541 | using up an alias set for them. (There are, of course, pointers | |
542 | and references to functions, but that's different.) */ | |
543 | else if (TREE_CODE (t) == FUNCTION_TYPE) | |
544 | set = 0; | |
74d86f4f RH |
545 | |
546 | /* Unless the language specifies otherwise, let vector types alias | |
547 | their components. This avoids some nasty type punning issues in | |
548 | normal usage. And indeed lets vectors be treated more like an | |
549 | array slice. */ | |
550 | else if (TREE_CODE (t) == VECTOR_TYPE) | |
551 | set = get_alias_set (TREE_TYPE (t)); | |
552 | ||
3bdf5ad1 RK |
553 | else |
554 | /* Otherwise make a new alias set for this type. */ | |
555 | set = new_alias_set (); | |
556 | ||
557 | TYPE_ALIAS_SET (t) = set; | |
2bf105ab RK |
558 | |
559 | /* If this is an aggregate type, we must record any component aliasing | |
560 | information. */ | |
1d79fd2c | 561 | if (AGGREGATE_TYPE_P (t) || TREE_CODE (t) == COMPLEX_TYPE) |
2bf105ab RK |
562 | record_component_aliases (t); |
563 | ||
3bdf5ad1 RK |
564 | return set; |
565 | } | |
566 | ||
567 | /* Return a brand-new alias set. */ | |
568 | ||
f103e34d GK |
569 | static GTY(()) HOST_WIDE_INT last_alias_set; |
570 | ||
3bdf5ad1 | 571 | HOST_WIDE_INT |
4682ae04 | 572 | new_alias_set (void) |
3bdf5ad1 | 573 | { |
3bdf5ad1 | 574 | if (flag_strict_aliasing) |
9ddb66ca | 575 | { |
3416f5c2 JH |
576 | if (!alias_sets) |
577 | VARRAY_GENERIC_PTR_INIT (alias_sets, 10, "alias sets"); | |
578 | else | |
579 | VARRAY_GROW (alias_sets, last_alias_set + 2); | |
9ddb66ca JH |
580 | return ++last_alias_set; |
581 | } | |
3bdf5ad1 RK |
582 | else |
583 | return 0; | |
584 | } | |
3932261a | 585 | |
01d28c3f JM |
586 | /* Indicate that things in SUBSET can alias things in SUPERSET, but that |
587 | not everything that aliases SUPERSET also aliases SUBSET. For example, | |
588 | in C, a store to an `int' can alias a load of a structure containing an | |
589 | `int', and vice versa. But it can't alias a load of a 'double' member | |
590 | of the same structure. Here, the structure would be the SUPERSET and | |
591 | `int' the SUBSET. This relationship is also described in the comment at | |
592 | the beginning of this file. | |
593 | ||
594 | This function should be called only once per SUPERSET/SUBSET pair. | |
3932261a MM |
595 | |
596 | It is illegal for SUPERSET to be zero; everything is implicitly a | |
597 | subset of alias set zero. */ | |
598 | ||
04e2b4d3 | 599 | static void |
4682ae04 | 600 | record_alias_subset (HOST_WIDE_INT superset, HOST_WIDE_INT subset) |
3932261a MM |
601 | { |
602 | alias_set_entry superset_entry; | |
603 | alias_set_entry subset_entry; | |
604 | ||
f47e9b4e RK |
605 | /* It is possible in complex type situations for both sets to be the same, |
606 | in which case we can ignore this operation. */ | |
607 | if (superset == subset) | |
608 | return; | |
609 | ||
298e6adc | 610 | gcc_assert (superset); |
3932261a MM |
611 | |
612 | superset_entry = get_alias_set_entry (superset); | |
ca7fd9cd | 613 | if (superset_entry == 0) |
3932261a MM |
614 | { |
615 | /* Create an entry for the SUPERSET, so that we have a place to | |
616 | attach the SUBSET. */ | |
b604074c | 617 | superset_entry = ggc_alloc (sizeof (struct alias_set_entry)); |
3932261a | 618 | superset_entry->alias_set = superset; |
ca7fd9cd | 619 | superset_entry->children |
b604074c | 620 | = splay_tree_new_ggc (splay_tree_compare_ints); |
570eb5c8 | 621 | superset_entry->has_zero_child = 0; |
9ddb66ca | 622 | VARRAY_GENERIC_PTR (alias_sets, superset) = superset_entry; |
3932261a MM |
623 | } |
624 | ||
2bf105ab RK |
625 | if (subset == 0) |
626 | superset_entry->has_zero_child = 1; | |
627 | else | |
628 | { | |
629 | subset_entry = get_alias_set_entry (subset); | |
630 | /* If there is an entry for the subset, enter all of its children | |
631 | (if they are not already present) as children of the SUPERSET. */ | |
ca7fd9cd | 632 | if (subset_entry) |
2bf105ab RK |
633 | { |
634 | if (subset_entry->has_zero_child) | |
635 | superset_entry->has_zero_child = 1; | |
d4b60170 | 636 | |
2bf105ab RK |
637 | splay_tree_foreach (subset_entry->children, insert_subset_children, |
638 | superset_entry->children); | |
639 | } | |
3932261a | 640 | |
2bf105ab | 641 | /* Enter the SUBSET itself as a child of the SUPERSET. */ |
ca7fd9cd | 642 | splay_tree_insert (superset_entry->children, |
2bf105ab RK |
643 | (splay_tree_key) subset, 0); |
644 | } | |
3932261a MM |
645 | } |
646 | ||
a0c33338 RK |
647 | /* Record that component types of TYPE, if any, are part of that type for |
648 | aliasing purposes. For record types, we only record component types | |
649 | for fields that are marked addressable. For array types, we always | |
650 | record the component types, so the front end should not call this | |
651 | function if the individual component aren't addressable. */ | |
652 | ||
653 | void | |
4682ae04 | 654 | record_component_aliases (tree type) |
a0c33338 | 655 | { |
3bdf5ad1 | 656 | HOST_WIDE_INT superset = get_alias_set (type); |
a0c33338 RK |
657 | tree field; |
658 | ||
659 | if (superset == 0) | |
660 | return; | |
661 | ||
662 | switch (TREE_CODE (type)) | |
663 | { | |
664 | case ARRAY_TYPE: | |
2bf105ab RK |
665 | if (! TYPE_NONALIASED_COMPONENT (type)) |
666 | record_alias_subset (superset, get_alias_set (TREE_TYPE (type))); | |
a0c33338 RK |
667 | break; |
668 | ||
669 | case RECORD_TYPE: | |
670 | case UNION_TYPE: | |
671 | case QUAL_UNION_TYPE: | |
6614fd40 | 672 | /* Recursively record aliases for the base classes, if there are any. */ |
fa743e8c | 673 | if (TYPE_BINFO (type)) |
ca7fd9cd KH |
674 | { |
675 | int i; | |
fa743e8c NS |
676 | tree binfo, base_binfo; |
677 | ||
678 | for (binfo = TYPE_BINFO (type), i = 0; | |
679 | BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) | |
680 | record_alias_subset (superset, | |
681 | get_alias_set (BINFO_TYPE (base_binfo))); | |
ca7fd9cd | 682 | } |
a0c33338 | 683 | for (field = TYPE_FIELDS (type); field != 0; field = TREE_CHAIN (field)) |
b16a49a1 | 684 | if (TREE_CODE (field) == FIELD_DECL && ! DECL_NONADDRESSABLE_P (field)) |
2bf105ab | 685 | record_alias_subset (superset, get_alias_set (TREE_TYPE (field))); |
a0c33338 RK |
686 | break; |
687 | ||
1d79fd2c JW |
688 | case COMPLEX_TYPE: |
689 | record_alias_subset (superset, get_alias_set (TREE_TYPE (type))); | |
690 | break; | |
691 | ||
a0c33338 RK |
692 | default: |
693 | break; | |
694 | } | |
695 | } | |
696 | ||
3bdf5ad1 RK |
697 | /* Allocate an alias set for use in storing and reading from the varargs |
698 | spill area. */ | |
699 | ||
f103e34d GK |
700 | static GTY(()) HOST_WIDE_INT varargs_set = -1; |
701 | ||
3bdf5ad1 | 702 | HOST_WIDE_INT |
4682ae04 | 703 | get_varargs_alias_set (void) |
3bdf5ad1 | 704 | { |
cd3ce9b4 JM |
705 | #if 1 |
706 | /* We now lower VA_ARG_EXPR, and there's currently no way to attach the | |
707 | varargs alias set to an INDIRECT_REF (FIXME!), so we can't | |
708 | consistently use the varargs alias set for loads from the varargs | |
709 | area. So don't use it anywhere. */ | |
710 | return 0; | |
711 | #else | |
f103e34d GK |
712 | if (varargs_set == -1) |
713 | varargs_set = new_alias_set (); | |
3bdf5ad1 | 714 | |
f103e34d | 715 | return varargs_set; |
cd3ce9b4 | 716 | #endif |
3bdf5ad1 RK |
717 | } |
718 | ||
719 | /* Likewise, but used for the fixed portions of the frame, e.g., register | |
720 | save areas. */ | |
721 | ||
f103e34d GK |
722 | static GTY(()) HOST_WIDE_INT frame_set = -1; |
723 | ||
3bdf5ad1 | 724 | HOST_WIDE_INT |
4682ae04 | 725 | get_frame_alias_set (void) |
3bdf5ad1 | 726 | { |
f103e34d GK |
727 | if (frame_set == -1) |
728 | frame_set = new_alias_set (); | |
3bdf5ad1 | 729 | |
f103e34d | 730 | return frame_set; |
3bdf5ad1 RK |
731 | } |
732 | ||
2a2c8203 JC |
733 | /* Inside SRC, the source of a SET, find a base address. */ |
734 | ||
9ae8ffe7 | 735 | static rtx |
4682ae04 | 736 | find_base_value (rtx src) |
9ae8ffe7 | 737 | { |
713f41f9 | 738 | unsigned int regno; |
0aacc8ed | 739 | |
9ae8ffe7 JL |
740 | switch (GET_CODE (src)) |
741 | { | |
742 | case SYMBOL_REF: | |
743 | case LABEL_REF: | |
744 | return src; | |
745 | ||
746 | case REG: | |
fb6754f0 | 747 | regno = REGNO (src); |
d4b60170 | 748 | /* At the start of a function, argument registers have known base |
2a2c8203 JC |
749 | values which may be lost later. Returning an ADDRESS |
750 | expression here allows optimization based on argument values | |
751 | even when the argument registers are used for other purposes. */ | |
713f41f9 BS |
752 | if (regno < FIRST_PSEUDO_REGISTER && copying_arguments) |
753 | return new_reg_base_value[regno]; | |
73774bc7 | 754 | |
eaf407a5 | 755 | /* If a pseudo has a known base value, return it. Do not do this |
9b462c42 RH |
756 | for non-fixed hard regs since it can result in a circular |
757 | dependency chain for registers which have values at function entry. | |
eaf407a5 JL |
758 | |
759 | The test above is not sufficient because the scheduler may move | |
760 | a copy out of an arg reg past the NOTE_INSN_FUNCTION_BEGIN. */ | |
9b462c42 | 761 | if ((regno >= FIRST_PSEUDO_REGISTER || fixed_regs[regno]) |
c582d54a | 762 | && regno < VARRAY_SIZE (reg_base_value)) |
83bbd9b6 RH |
763 | { |
764 | /* If we're inside init_alias_analysis, use new_reg_base_value | |
765 | to reduce the number of relaxation iterations. */ | |
1afdf91c RH |
766 | if (new_reg_base_value && new_reg_base_value[regno] |
767 | && REG_N_SETS (regno) == 1) | |
83bbd9b6 RH |
768 | return new_reg_base_value[regno]; |
769 | ||
c582d54a JH |
770 | if (VARRAY_RTX (reg_base_value, regno)) |
771 | return VARRAY_RTX (reg_base_value, regno); | |
83bbd9b6 | 772 | } |
73774bc7 | 773 | |
e3f049a8 | 774 | return 0; |
9ae8ffe7 JL |
775 | |
776 | case MEM: | |
777 | /* Check for an argument passed in memory. Only record in the | |
778 | copying-arguments block; it is too hard to track changes | |
779 | otherwise. */ | |
780 | if (copying_arguments | |
781 | && (XEXP (src, 0) == arg_pointer_rtx | |
782 | || (GET_CODE (XEXP (src, 0)) == PLUS | |
783 | && XEXP (XEXP (src, 0), 0) == arg_pointer_rtx))) | |
38a448ca | 784 | return gen_rtx_ADDRESS (VOIDmode, src); |
9ae8ffe7 JL |
785 | return 0; |
786 | ||
787 | case CONST: | |
788 | src = XEXP (src, 0); | |
789 | if (GET_CODE (src) != PLUS && GET_CODE (src) != MINUS) | |
790 | break; | |
d4b60170 | 791 | |
ec5c56db | 792 | /* ... fall through ... */ |
2a2c8203 | 793 | |
9ae8ffe7 JL |
794 | case PLUS: |
795 | case MINUS: | |
2a2c8203 | 796 | { |
ec907dd8 JL |
797 | rtx temp, src_0 = XEXP (src, 0), src_1 = XEXP (src, 1); |
798 | ||
0134bf2d DE |
799 | /* If either operand is a REG that is a known pointer, then it |
800 | is the base. */ | |
801 | if (REG_P (src_0) && REG_POINTER (src_0)) | |
802 | return find_base_value (src_0); | |
803 | if (REG_P (src_1) && REG_POINTER (src_1)) | |
804 | return find_base_value (src_1); | |
805 | ||
ec907dd8 JL |
806 | /* If either operand is a REG, then see if we already have |
807 | a known value for it. */ | |
0134bf2d | 808 | if (REG_P (src_0)) |
ec907dd8 JL |
809 | { |
810 | temp = find_base_value (src_0); | |
d4b60170 | 811 | if (temp != 0) |
ec907dd8 JL |
812 | src_0 = temp; |
813 | } | |
814 | ||
0134bf2d | 815 | if (REG_P (src_1)) |
ec907dd8 JL |
816 | { |
817 | temp = find_base_value (src_1); | |
d4b60170 | 818 | if (temp!= 0) |
ec907dd8 JL |
819 | src_1 = temp; |
820 | } | |
2a2c8203 | 821 | |
0134bf2d DE |
822 | /* If either base is named object or a special address |
823 | (like an argument or stack reference), then use it for the | |
824 | base term. */ | |
825 | if (src_0 != 0 | |
826 | && (GET_CODE (src_0) == SYMBOL_REF | |
827 | || GET_CODE (src_0) == LABEL_REF | |
828 | || (GET_CODE (src_0) == ADDRESS | |
829 | && GET_MODE (src_0) != VOIDmode))) | |
830 | return src_0; | |
831 | ||
832 | if (src_1 != 0 | |
833 | && (GET_CODE (src_1) == SYMBOL_REF | |
834 | || GET_CODE (src_1) == LABEL_REF | |
835 | || (GET_CODE (src_1) == ADDRESS | |
836 | && GET_MODE (src_1) != VOIDmode))) | |
837 | return src_1; | |
838 | ||
d4b60170 | 839 | /* Guess which operand is the base address: |
ec907dd8 JL |
840 | If either operand is a symbol, then it is the base. If |
841 | either operand is a CONST_INT, then the other is the base. */ | |
d4b60170 | 842 | if (GET_CODE (src_1) == CONST_INT || CONSTANT_P (src_0)) |
2a2c8203 | 843 | return find_base_value (src_0); |
d4b60170 | 844 | else if (GET_CODE (src_0) == CONST_INT || CONSTANT_P (src_1)) |
ec907dd8 JL |
845 | return find_base_value (src_1); |
846 | ||
9ae8ffe7 | 847 | return 0; |
2a2c8203 JC |
848 | } |
849 | ||
850 | case LO_SUM: | |
851 | /* The standard form is (lo_sum reg sym) so look only at the | |
852 | second operand. */ | |
853 | return find_base_value (XEXP (src, 1)); | |
9ae8ffe7 JL |
854 | |
855 | case AND: | |
856 | /* If the second operand is constant set the base | |
ec5c56db | 857 | address to the first operand. */ |
2a2c8203 JC |
858 | if (GET_CODE (XEXP (src, 1)) == CONST_INT && INTVAL (XEXP (src, 1)) != 0) |
859 | return find_base_value (XEXP (src, 0)); | |
9ae8ffe7 JL |
860 | return 0; |
861 | ||
61f0131c R |
862 | case TRUNCATE: |
863 | if (GET_MODE_SIZE (GET_MODE (src)) < GET_MODE_SIZE (Pmode)) | |
864 | break; | |
865 | /* Fall through. */ | |
9ae8ffe7 | 866 | case HIGH: |
d288e53d DE |
867 | case PRE_INC: |
868 | case PRE_DEC: | |
869 | case POST_INC: | |
870 | case POST_DEC: | |
871 | case PRE_MODIFY: | |
872 | case POST_MODIFY: | |
2a2c8203 | 873 | return find_base_value (XEXP (src, 0)); |
1d300e19 | 874 | |
0aacc8ed RK |
875 | case ZERO_EXTEND: |
876 | case SIGN_EXTEND: /* used for NT/Alpha pointers */ | |
877 | { | |
878 | rtx temp = find_base_value (XEXP (src, 0)); | |
879 | ||
5ae6cd0d | 880 | if (temp != 0 && CONSTANT_P (temp)) |
0aacc8ed | 881 | temp = convert_memory_address (Pmode, temp); |
0aacc8ed RK |
882 | |
883 | return temp; | |
884 | } | |
885 | ||
1d300e19 KG |
886 | default: |
887 | break; | |
9ae8ffe7 JL |
888 | } |
889 | ||
890 | return 0; | |
891 | } | |
892 | ||
893 | /* Called from init_alias_analysis indirectly through note_stores. */ | |
894 | ||
d4b60170 | 895 | /* While scanning insns to find base values, reg_seen[N] is nonzero if |
9ae8ffe7 JL |
896 | register N has been set in this function. */ |
897 | static char *reg_seen; | |
898 | ||
13309a5f JC |
899 | /* Addresses which are known not to alias anything else are identified |
900 | by a unique integer. */ | |
ec907dd8 JL |
901 | static int unique_id; |
902 | ||
2a2c8203 | 903 | static void |
4682ae04 | 904 | record_set (rtx dest, rtx set, void *data ATTRIBUTE_UNUSED) |
9ae8ffe7 | 905 | { |
b3694847 | 906 | unsigned regno; |
9ae8ffe7 | 907 | rtx src; |
c28b4e40 | 908 | int n; |
9ae8ffe7 | 909 | |
f8cfc6aa | 910 | if (!REG_P (dest)) |
9ae8ffe7 JL |
911 | return; |
912 | ||
fb6754f0 | 913 | regno = REGNO (dest); |
9ae8ffe7 | 914 | |
298e6adc | 915 | gcc_assert (regno < VARRAY_SIZE (reg_base_value)); |
ac606739 | 916 | |
c28b4e40 JW |
917 | /* If this spans multiple hard registers, then we must indicate that every |
918 | register has an unusable value. */ | |
919 | if (regno < FIRST_PSEUDO_REGISTER) | |
66fd46b6 | 920 | n = hard_regno_nregs[regno][GET_MODE (dest)]; |
c28b4e40 JW |
921 | else |
922 | n = 1; | |
923 | if (n != 1) | |
924 | { | |
925 | while (--n >= 0) | |
926 | { | |
927 | reg_seen[regno + n] = 1; | |
928 | new_reg_base_value[regno + n] = 0; | |
929 | } | |
930 | return; | |
931 | } | |
932 | ||
9ae8ffe7 JL |
933 | if (set) |
934 | { | |
935 | /* A CLOBBER wipes out any old value but does not prevent a previously | |
936 | unset register from acquiring a base address (i.e. reg_seen is not | |
937 | set). */ | |
938 | if (GET_CODE (set) == CLOBBER) | |
939 | { | |
ec907dd8 | 940 | new_reg_base_value[regno] = 0; |
9ae8ffe7 JL |
941 | return; |
942 | } | |
943 | src = SET_SRC (set); | |
944 | } | |
945 | else | |
946 | { | |
9ae8ffe7 JL |
947 | if (reg_seen[regno]) |
948 | { | |
ec907dd8 | 949 | new_reg_base_value[regno] = 0; |
9ae8ffe7 JL |
950 | return; |
951 | } | |
952 | reg_seen[regno] = 1; | |
38a448ca RH |
953 | new_reg_base_value[regno] = gen_rtx_ADDRESS (Pmode, |
954 | GEN_INT (unique_id++)); | |
9ae8ffe7 JL |
955 | return; |
956 | } | |
957 | ||
5da6f168 RS |
958 | /* If this is not the first set of REGNO, see whether the new value |
959 | is related to the old one. There are two cases of interest: | |
960 | ||
961 | (1) The register might be assigned an entirely new value | |
962 | that has the same base term as the original set. | |
963 | ||
964 | (2) The set might be a simple self-modification that | |
965 | cannot change REGNO's base value. | |
966 | ||
967 | If neither case holds, reject the original base value as invalid. | |
968 | Note that the following situation is not detected: | |
969 | ||
970 | extern int x, y; int *p = &x; p += (&y-&x); | |
971 | ||
9ae8ffe7 JL |
972 | ANSI C does not allow computing the difference of addresses |
973 | of distinct top level objects. */ | |
5da6f168 RS |
974 | if (new_reg_base_value[regno] != 0 |
975 | && find_base_value (src) != new_reg_base_value[regno]) | |
9ae8ffe7 JL |
976 | switch (GET_CODE (src)) |
977 | { | |
2a2c8203 | 978 | case LO_SUM: |
9ae8ffe7 JL |
979 | case MINUS: |
980 | if (XEXP (src, 0) != dest && XEXP (src, 1) != dest) | |
ec907dd8 | 981 | new_reg_base_value[regno] = 0; |
9ae8ffe7 | 982 | break; |
61f0131c R |
983 | case PLUS: |
984 | /* If the value we add in the PLUS is also a valid base value, | |
985 | this might be the actual base value, and the original value | |
986 | an index. */ | |
987 | { | |
988 | rtx other = NULL_RTX; | |
989 | ||
990 | if (XEXP (src, 0) == dest) | |
991 | other = XEXP (src, 1); | |
992 | else if (XEXP (src, 1) == dest) | |
993 | other = XEXP (src, 0); | |
994 | ||
995 | if (! other || find_base_value (other)) | |
996 | new_reg_base_value[regno] = 0; | |
997 | break; | |
998 | } | |
9ae8ffe7 JL |
999 | case AND: |
1000 | if (XEXP (src, 0) != dest || GET_CODE (XEXP (src, 1)) != CONST_INT) | |
ec907dd8 | 1001 | new_reg_base_value[regno] = 0; |
9ae8ffe7 | 1002 | break; |
9ae8ffe7 | 1003 | default: |
ec907dd8 | 1004 | new_reg_base_value[regno] = 0; |
9ae8ffe7 JL |
1005 | break; |
1006 | } | |
1007 | /* If this is the first set of a register, record the value. */ | |
1008 | else if ((regno >= FIRST_PSEUDO_REGISTER || ! fixed_regs[regno]) | |
ec907dd8 JL |
1009 | && ! reg_seen[regno] && new_reg_base_value[regno] == 0) |
1010 | new_reg_base_value[regno] = find_base_value (src); | |
9ae8ffe7 JL |
1011 | |
1012 | reg_seen[regno] = 1; | |
1013 | } | |
1014 | ||
ac3d9668 RK |
1015 | /* Called from loop optimization when a new pseudo-register is |
1016 | created. It indicates that REGNO is being set to VAL. f INVARIANT | |
1017 | is true then this value also describes an invariant relationship | |
1018 | which can be used to deduce that two registers with unknown values | |
1019 | are different. */ | |
d4b60170 | 1020 | |
9ae8ffe7 | 1021 | void |
4682ae04 | 1022 | record_base_value (unsigned int regno, rtx val, int invariant) |
9ae8ffe7 | 1023 | { |
c582d54a | 1024 | if (invariant && alias_invariant && regno < alias_invariant_size) |
de12be17 JC |
1025 | alias_invariant[regno] = val; |
1026 | ||
c582d54a JH |
1027 | if (regno >= VARRAY_SIZE (reg_base_value)) |
1028 | VARRAY_GROW (reg_base_value, max_reg_num ()); | |
1029 | ||
f8cfc6aa | 1030 | if (REG_P (val)) |
9ae8ffe7 | 1031 | { |
c582d54a JH |
1032 | VARRAY_RTX (reg_base_value, regno) |
1033 | = REG_BASE_VALUE (val); | |
9ae8ffe7 JL |
1034 | return; |
1035 | } | |
c582d54a JH |
1036 | VARRAY_RTX (reg_base_value, regno) |
1037 | = find_base_value (val); | |
9ae8ffe7 JL |
1038 | } |
1039 | ||
43fe47ca JW |
1040 | /* Clear alias info for a register. This is used if an RTL transformation |
1041 | changes the value of a register. This is used in flow by AUTO_INC_DEC | |
1042 | optimizations. We don't need to clear reg_base_value, since flow only | |
1043 | changes the offset. */ | |
1044 | ||
1045 | void | |
4682ae04 | 1046 | clear_reg_alias_info (rtx reg) |
43fe47ca | 1047 | { |
4e1a4144 JW |
1048 | unsigned int regno = REGNO (reg); |
1049 | ||
bb1acb3e RH |
1050 | if (regno >= FIRST_PSEUDO_REGISTER) |
1051 | { | |
1052 | regno -= FIRST_PSEUDO_REGISTER; | |
1053 | if (regno < reg_known_value_size) | |
1054 | { | |
1055 | reg_known_value[regno] = reg; | |
1056 | reg_known_equiv_p[regno] = false; | |
1057 | } | |
1058 | } | |
1059 | } | |
1060 | ||
1061 | /* If a value is known for REGNO, return it. */ | |
1062 | ||
1063 | rtx | |
1064 | get_reg_known_value (unsigned int regno) | |
1065 | { | |
1066 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1067 | { | |
1068 | regno -= FIRST_PSEUDO_REGISTER; | |
1069 | if (regno < reg_known_value_size) | |
1070 | return reg_known_value[regno]; | |
1071 | } | |
1072 | return NULL; | |
43fe47ca JW |
1073 | } |
1074 | ||
bb1acb3e RH |
1075 | /* Set it. */ |
1076 | ||
1077 | static void | |
1078 | set_reg_known_value (unsigned int regno, rtx val) | |
1079 | { | |
1080 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1081 | { | |
1082 | regno -= FIRST_PSEUDO_REGISTER; | |
1083 | if (regno < reg_known_value_size) | |
1084 | reg_known_value[regno] = val; | |
1085 | } | |
1086 | } | |
1087 | ||
1088 | /* Similarly for reg_known_equiv_p. */ | |
1089 | ||
1090 | bool | |
1091 | get_reg_known_equiv_p (unsigned int regno) | |
1092 | { | |
1093 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1094 | { | |
1095 | regno -= FIRST_PSEUDO_REGISTER; | |
1096 | if (regno < reg_known_value_size) | |
1097 | return reg_known_equiv_p[regno]; | |
1098 | } | |
1099 | return false; | |
1100 | } | |
1101 | ||
1102 | static void | |
1103 | set_reg_known_equiv_p (unsigned int regno, bool val) | |
1104 | { | |
1105 | if (regno >= FIRST_PSEUDO_REGISTER) | |
1106 | { | |
1107 | regno -= FIRST_PSEUDO_REGISTER; | |
1108 | if (regno < reg_known_value_size) | |
1109 | reg_known_equiv_p[regno] = val; | |
1110 | } | |
1111 | } | |
1112 | ||
1113 | ||
db048faf MM |
1114 | /* Returns a canonical version of X, from the point of view alias |
1115 | analysis. (For example, if X is a MEM whose address is a register, | |
1116 | and the register has a known value (say a SYMBOL_REF), then a MEM | |
1117 | whose address is the SYMBOL_REF is returned.) */ | |
1118 | ||
1119 | rtx | |
4682ae04 | 1120 | canon_rtx (rtx x) |
9ae8ffe7 JL |
1121 | { |
1122 | /* Recursively look for equivalences. */ | |
f8cfc6aa | 1123 | if (REG_P (x) && REGNO (x) >= FIRST_PSEUDO_REGISTER) |
bb1acb3e RH |
1124 | { |
1125 | rtx t = get_reg_known_value (REGNO (x)); | |
1126 | if (t == x) | |
1127 | return x; | |
1128 | if (t) | |
1129 | return canon_rtx (t); | |
1130 | } | |
1131 | ||
1132 | if (GET_CODE (x) == PLUS) | |
9ae8ffe7 JL |
1133 | { |
1134 | rtx x0 = canon_rtx (XEXP (x, 0)); | |
1135 | rtx x1 = canon_rtx (XEXP (x, 1)); | |
1136 | ||
1137 | if (x0 != XEXP (x, 0) || x1 != XEXP (x, 1)) | |
1138 | { | |
9ae8ffe7 | 1139 | if (GET_CODE (x0) == CONST_INT) |
ed8908e7 | 1140 | return plus_constant (x1, INTVAL (x0)); |
9ae8ffe7 | 1141 | else if (GET_CODE (x1) == CONST_INT) |
ed8908e7 | 1142 | return plus_constant (x0, INTVAL (x1)); |
38a448ca | 1143 | return gen_rtx_PLUS (GET_MODE (x), x0, x1); |
9ae8ffe7 JL |
1144 | } |
1145 | } | |
d4b60170 | 1146 | |
9ae8ffe7 JL |
1147 | /* This gives us much better alias analysis when called from |
1148 | the loop optimizer. Note we want to leave the original | |
1149 | MEM alone, but need to return the canonicalized MEM with | |
1150 | all the flags with their original values. */ | |
3c0cb5de | 1151 | else if (MEM_P (x)) |
f1ec5147 | 1152 | x = replace_equiv_address_nv (x, canon_rtx (XEXP (x, 0))); |
d4b60170 | 1153 | |
9ae8ffe7 JL |
1154 | return x; |
1155 | } | |
1156 | ||
1157 | /* Return 1 if X and Y are identical-looking rtx's. | |
45183e03 | 1158 | Expect that X and Y has been already canonicalized. |
9ae8ffe7 JL |
1159 | |
1160 | We use the data in reg_known_value above to see if two registers with | |
1161 | different numbers are, in fact, equivalent. */ | |
1162 | ||
1163 | static int | |
4682ae04 | 1164 | rtx_equal_for_memref_p (rtx x, rtx y) |
9ae8ffe7 | 1165 | { |
b3694847 SS |
1166 | int i; |
1167 | int j; | |
1168 | enum rtx_code code; | |
1169 | const char *fmt; | |
9ae8ffe7 JL |
1170 | |
1171 | if (x == 0 && y == 0) | |
1172 | return 1; | |
1173 | if (x == 0 || y == 0) | |
1174 | return 0; | |
d4b60170 | 1175 | |
9ae8ffe7 JL |
1176 | if (x == y) |
1177 | return 1; | |
1178 | ||
1179 | code = GET_CODE (x); | |
1180 | /* Rtx's of different codes cannot be equal. */ | |
1181 | if (code != GET_CODE (y)) | |
1182 | return 0; | |
1183 | ||
1184 | /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. | |
1185 | (REG:SI x) and (REG:HI x) are NOT equivalent. */ | |
1186 | ||
1187 | if (GET_MODE (x) != GET_MODE (y)) | |
1188 | return 0; | |
1189 | ||
db048faf MM |
1190 | /* Some RTL can be compared without a recursive examination. */ |
1191 | switch (code) | |
1192 | { | |
1193 | case REG: | |
1194 | return REGNO (x) == REGNO (y); | |
1195 | ||
1196 | case LABEL_REF: | |
1197 | return XEXP (x, 0) == XEXP (y, 0); | |
ca7fd9cd | 1198 | |
db048faf MM |
1199 | case SYMBOL_REF: |
1200 | return XSTR (x, 0) == XSTR (y, 0); | |
1201 | ||
40e02b4a | 1202 | case VALUE: |
db048faf MM |
1203 | case CONST_INT: |
1204 | case CONST_DOUBLE: | |
1205 | /* There's no need to compare the contents of CONST_DOUBLEs or | |
1206 | CONST_INTs because pointer equality is a good enough | |
1207 | comparison for these nodes. */ | |
1208 | return 0; | |
1209 | ||
db048faf MM |
1210 | default: |
1211 | break; | |
1212 | } | |
9ae8ffe7 | 1213 | |
45183e03 JH |
1214 | /* canon_rtx knows how to handle plus. No need to canonicalize. */ |
1215 | if (code == PLUS) | |
9ae8ffe7 JL |
1216 | return ((rtx_equal_for_memref_p (XEXP (x, 0), XEXP (y, 0)) |
1217 | && rtx_equal_for_memref_p (XEXP (x, 1), XEXP (y, 1))) | |
1218 | || (rtx_equal_for_memref_p (XEXP (x, 0), XEXP (y, 1)) | |
1219 | && rtx_equal_for_memref_p (XEXP (x, 1), XEXP (y, 0)))); | |
45183e03 JH |
1220 | /* For commutative operations, the RTX match if the operand match in any |
1221 | order. Also handle the simple binary and unary cases without a loop. */ | |
ec8e098d | 1222 | if (COMMUTATIVE_P (x)) |
45183e03 JH |
1223 | { |
1224 | rtx xop0 = canon_rtx (XEXP (x, 0)); | |
1225 | rtx yop0 = canon_rtx (XEXP (y, 0)); | |
1226 | rtx yop1 = canon_rtx (XEXP (y, 1)); | |
1227 | ||
1228 | return ((rtx_equal_for_memref_p (xop0, yop0) | |
1229 | && rtx_equal_for_memref_p (canon_rtx (XEXP (x, 1)), yop1)) | |
1230 | || (rtx_equal_for_memref_p (xop0, yop1) | |
1231 | && rtx_equal_for_memref_p (canon_rtx (XEXP (x, 1)), yop0))); | |
1232 | } | |
ec8e098d | 1233 | else if (NON_COMMUTATIVE_P (x)) |
45183e03 JH |
1234 | { |
1235 | return (rtx_equal_for_memref_p (canon_rtx (XEXP (x, 0)), | |
4682ae04 | 1236 | canon_rtx (XEXP (y, 0))) |
45183e03 JH |
1237 | && rtx_equal_for_memref_p (canon_rtx (XEXP (x, 1)), |
1238 | canon_rtx (XEXP (y, 1)))); | |
1239 | } | |
ec8e098d | 1240 | else if (UNARY_P (x)) |
45183e03 | 1241 | return rtx_equal_for_memref_p (canon_rtx (XEXP (x, 0)), |
4682ae04 | 1242 | canon_rtx (XEXP (y, 0))); |
9ae8ffe7 JL |
1243 | |
1244 | /* Compare the elements. If any pair of corresponding elements | |
de12be17 JC |
1245 | fail to match, return 0 for the whole things. |
1246 | ||
1247 | Limit cases to types which actually appear in addresses. */ | |
9ae8ffe7 JL |
1248 | |
1249 | fmt = GET_RTX_FORMAT (code); | |
1250 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
1251 | { | |
1252 | switch (fmt[i]) | |
1253 | { | |
9ae8ffe7 JL |
1254 | case 'i': |
1255 | if (XINT (x, i) != XINT (y, i)) | |
1256 | return 0; | |
1257 | break; | |
1258 | ||
9ae8ffe7 JL |
1259 | case 'E': |
1260 | /* Two vectors must have the same length. */ | |
1261 | if (XVECLEN (x, i) != XVECLEN (y, i)) | |
1262 | return 0; | |
1263 | ||
1264 | /* And the corresponding elements must match. */ | |
1265 | for (j = 0; j < XVECLEN (x, i); j++) | |
45183e03 JH |
1266 | if (rtx_equal_for_memref_p (canon_rtx (XVECEXP (x, i, j)), |
1267 | canon_rtx (XVECEXP (y, i, j))) == 0) | |
9ae8ffe7 JL |
1268 | return 0; |
1269 | break; | |
1270 | ||
1271 | case 'e': | |
45183e03 JH |
1272 | if (rtx_equal_for_memref_p (canon_rtx (XEXP (x, i)), |
1273 | canon_rtx (XEXP (y, i))) == 0) | |
9ae8ffe7 JL |
1274 | return 0; |
1275 | break; | |
1276 | ||
3237ac18 AH |
1277 | /* This can happen for asm operands. */ |
1278 | case 's': | |
1279 | if (strcmp (XSTR (x, i), XSTR (y, i))) | |
1280 | return 0; | |
1281 | break; | |
1282 | ||
aee21ba9 JL |
1283 | /* This can happen for an asm which clobbers memory. */ |
1284 | case '0': | |
1285 | break; | |
1286 | ||
9ae8ffe7 JL |
1287 | /* It is believed that rtx's at this level will never |
1288 | contain anything but integers and other rtx's, | |
1289 | except for within LABEL_REFs and SYMBOL_REFs. */ | |
1290 | default: | |
298e6adc | 1291 | gcc_unreachable (); |
9ae8ffe7 JL |
1292 | } |
1293 | } | |
1294 | return 1; | |
1295 | } | |
1296 | ||
1297 | /* Given an rtx X, find a SYMBOL_REF or LABEL_REF within | |
1298 | X and return it, or return 0 if none found. */ | |
1299 | ||
1300 | static rtx | |
4682ae04 | 1301 | find_symbolic_term (rtx x) |
9ae8ffe7 | 1302 | { |
b3694847 SS |
1303 | int i; |
1304 | enum rtx_code code; | |
1305 | const char *fmt; | |
9ae8ffe7 JL |
1306 | |
1307 | code = GET_CODE (x); | |
1308 | if (code == SYMBOL_REF || code == LABEL_REF) | |
1309 | return x; | |
ec8e098d | 1310 | if (OBJECT_P (x)) |
9ae8ffe7 JL |
1311 | return 0; |
1312 | ||
1313 | fmt = GET_RTX_FORMAT (code); | |
1314 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
1315 | { | |
1316 | rtx t; | |
1317 | ||
1318 | if (fmt[i] == 'e') | |
1319 | { | |
1320 | t = find_symbolic_term (XEXP (x, i)); | |
1321 | if (t != 0) | |
1322 | return t; | |
1323 | } | |
1324 | else if (fmt[i] == 'E') | |
1325 | break; | |
1326 | } | |
1327 | return 0; | |
1328 | } | |
1329 | ||
94f24ddc | 1330 | rtx |
4682ae04 | 1331 | find_base_term (rtx x) |
9ae8ffe7 | 1332 | { |
eab5c70a BS |
1333 | cselib_val *val; |
1334 | struct elt_loc_list *l; | |
1335 | ||
b949ea8b JW |
1336 | #if defined (FIND_BASE_TERM) |
1337 | /* Try machine-dependent ways to find the base term. */ | |
1338 | x = FIND_BASE_TERM (x); | |
1339 | #endif | |
1340 | ||
9ae8ffe7 JL |
1341 | switch (GET_CODE (x)) |
1342 | { | |
1343 | case REG: | |
1344 | return REG_BASE_VALUE (x); | |
1345 | ||
d288e53d DE |
1346 | case TRUNCATE: |
1347 | if (GET_MODE_SIZE (GET_MODE (x)) < GET_MODE_SIZE (Pmode)) | |
ca7fd9cd | 1348 | return 0; |
d288e53d | 1349 | /* Fall through. */ |
9ae8ffe7 | 1350 | case HIGH: |
6d849a2a JL |
1351 | case PRE_INC: |
1352 | case PRE_DEC: | |
1353 | case POST_INC: | |
1354 | case POST_DEC: | |
d288e53d DE |
1355 | case PRE_MODIFY: |
1356 | case POST_MODIFY: | |
6d849a2a JL |
1357 | return find_base_term (XEXP (x, 0)); |
1358 | ||
1abade85 RK |
1359 | case ZERO_EXTEND: |
1360 | case SIGN_EXTEND: /* Used for Alpha/NT pointers */ | |
1361 | { | |
1362 | rtx temp = find_base_term (XEXP (x, 0)); | |
1363 | ||
5ae6cd0d | 1364 | if (temp != 0 && CONSTANT_P (temp)) |
1abade85 | 1365 | temp = convert_memory_address (Pmode, temp); |
1abade85 RK |
1366 | |
1367 | return temp; | |
1368 | } | |
1369 | ||
eab5c70a BS |
1370 | case VALUE: |
1371 | val = CSELIB_VAL_PTR (x); | |
40e02b4a JH |
1372 | if (!val) |
1373 | return 0; | |
eab5c70a BS |
1374 | for (l = val->locs; l; l = l->next) |
1375 | if ((x = find_base_term (l->loc)) != 0) | |
1376 | return x; | |
1377 | return 0; | |
1378 | ||
9ae8ffe7 JL |
1379 | case CONST: |
1380 | x = XEXP (x, 0); | |
1381 | if (GET_CODE (x) != PLUS && GET_CODE (x) != MINUS) | |
1382 | return 0; | |
938d968e | 1383 | /* Fall through. */ |
9ae8ffe7 JL |
1384 | case LO_SUM: |
1385 | case PLUS: | |
1386 | case MINUS: | |
1387 | { | |
3c567fae JL |
1388 | rtx tmp1 = XEXP (x, 0); |
1389 | rtx tmp2 = XEXP (x, 1); | |
1390 | ||
f5143c46 | 1391 | /* This is a little bit tricky since we have to determine which of |
3c567fae JL |
1392 | the two operands represents the real base address. Otherwise this |
1393 | routine may return the index register instead of the base register. | |
1394 | ||
1395 | That may cause us to believe no aliasing was possible, when in | |
1396 | fact aliasing is possible. | |
1397 | ||
1398 | We use a few simple tests to guess the base register. Additional | |
1399 | tests can certainly be added. For example, if one of the operands | |
1400 | is a shift or multiply, then it must be the index register and the | |
1401 | other operand is the base register. */ | |
ca7fd9cd | 1402 | |
b949ea8b JW |
1403 | if (tmp1 == pic_offset_table_rtx && CONSTANT_P (tmp2)) |
1404 | return find_base_term (tmp2); | |
1405 | ||
3c567fae JL |
1406 | /* If either operand is known to be a pointer, then use it |
1407 | to determine the base term. */ | |
3502dc9c | 1408 | if (REG_P (tmp1) && REG_POINTER (tmp1)) |
3c567fae JL |
1409 | return find_base_term (tmp1); |
1410 | ||
3502dc9c | 1411 | if (REG_P (tmp2) && REG_POINTER (tmp2)) |
3c567fae JL |
1412 | return find_base_term (tmp2); |
1413 | ||
1414 | /* Neither operand was known to be a pointer. Go ahead and find the | |
1415 | base term for both operands. */ | |
1416 | tmp1 = find_base_term (tmp1); | |
1417 | tmp2 = find_base_term (tmp2); | |
1418 | ||
1419 | /* If either base term is named object or a special address | |
1420 | (like an argument or stack reference), then use it for the | |
1421 | base term. */ | |
d4b60170 | 1422 | if (tmp1 != 0 |
3c567fae JL |
1423 | && (GET_CODE (tmp1) == SYMBOL_REF |
1424 | || GET_CODE (tmp1) == LABEL_REF | |
1425 | || (GET_CODE (tmp1) == ADDRESS | |
1426 | && GET_MODE (tmp1) != VOIDmode))) | |
1427 | return tmp1; | |
1428 | ||
d4b60170 | 1429 | if (tmp2 != 0 |
3c567fae JL |
1430 | && (GET_CODE (tmp2) == SYMBOL_REF |
1431 | || GET_CODE (tmp2) == LABEL_REF | |
1432 | || (GET_CODE (tmp2) == ADDRESS | |
1433 | && GET_MODE (tmp2) != VOIDmode))) | |
1434 | return tmp2; | |
1435 | ||
1436 | /* We could not determine which of the two operands was the | |
1437 | base register and which was the index. So we can determine | |
1438 | nothing from the base alias check. */ | |
1439 | return 0; | |
9ae8ffe7 JL |
1440 | } |
1441 | ||
1442 | case AND: | |
d288e53d DE |
1443 | if (GET_CODE (XEXP (x, 1)) == CONST_INT && INTVAL (XEXP (x, 1)) != 0) |
1444 | return find_base_term (XEXP (x, 0)); | |
9ae8ffe7 JL |
1445 | return 0; |
1446 | ||
1447 | case SYMBOL_REF: | |
1448 | case LABEL_REF: | |
1449 | return x; | |
1450 | ||
1451 | default: | |
1452 | return 0; | |
1453 | } | |
1454 | } | |
1455 | ||
1456 | /* Return 0 if the addresses X and Y are known to point to different | |
1457 | objects, 1 if they might be pointers to the same object. */ | |
1458 | ||
1459 | static int | |
4682ae04 AJ |
1460 | base_alias_check (rtx x, rtx y, enum machine_mode x_mode, |
1461 | enum machine_mode y_mode) | |
9ae8ffe7 JL |
1462 | { |
1463 | rtx x_base = find_base_term (x); | |
1464 | rtx y_base = find_base_term (y); | |
1465 | ||
1c72c7f6 JC |
1466 | /* If the address itself has no known base see if a known equivalent |
1467 | value has one. If either address still has no known base, nothing | |
1468 | is known about aliasing. */ | |
1469 | if (x_base == 0) | |
1470 | { | |
1471 | rtx x_c; | |
d4b60170 | 1472 | |
1c72c7f6 JC |
1473 | if (! flag_expensive_optimizations || (x_c = canon_rtx (x)) == x) |
1474 | return 1; | |
d4b60170 | 1475 | |
1c72c7f6 JC |
1476 | x_base = find_base_term (x_c); |
1477 | if (x_base == 0) | |
1478 | return 1; | |
1479 | } | |
9ae8ffe7 | 1480 | |
1c72c7f6 JC |
1481 | if (y_base == 0) |
1482 | { | |
1483 | rtx y_c; | |
1484 | if (! flag_expensive_optimizations || (y_c = canon_rtx (y)) == y) | |
1485 | return 1; | |
d4b60170 | 1486 | |
1c72c7f6 JC |
1487 | y_base = find_base_term (y_c); |
1488 | if (y_base == 0) | |
1489 | return 1; | |
1490 | } | |
1491 | ||
1492 | /* If the base addresses are equal nothing is known about aliasing. */ | |
1493 | if (rtx_equal_p (x_base, y_base)) | |
9ae8ffe7 JL |
1494 | return 1; |
1495 | ||
ca7fd9cd | 1496 | /* The base addresses of the read and write are different expressions. |
56ee9281 RH |
1497 | If they are both symbols and they are not accessed via AND, there is |
1498 | no conflict. We can bring knowledge of object alignment into play | |
1499 | here. For example, on alpha, "char a, b;" can alias one another, | |
1500 | though "char a; long b;" cannot. */ | |
9ae8ffe7 | 1501 | if (GET_CODE (x_base) != ADDRESS && GET_CODE (y_base) != ADDRESS) |
c02f035f | 1502 | { |
56ee9281 RH |
1503 | if (GET_CODE (x) == AND && GET_CODE (y) == AND) |
1504 | return 1; | |
1505 | if (GET_CODE (x) == AND | |
1506 | && (GET_CODE (XEXP (x, 1)) != CONST_INT | |
8fa2140d | 1507 | || (int) GET_MODE_UNIT_SIZE (y_mode) < -INTVAL (XEXP (x, 1)))) |
56ee9281 RH |
1508 | return 1; |
1509 | if (GET_CODE (y) == AND | |
1510 | && (GET_CODE (XEXP (y, 1)) != CONST_INT | |
8fa2140d | 1511 | || (int) GET_MODE_UNIT_SIZE (x_mode) < -INTVAL (XEXP (y, 1)))) |
56ee9281 | 1512 | return 1; |
b2972551 JL |
1513 | /* Differing symbols never alias. */ |
1514 | return 0; | |
c02f035f | 1515 | } |
9ae8ffe7 JL |
1516 | |
1517 | /* If one address is a stack reference there can be no alias: | |
1518 | stack references using different base registers do not alias, | |
1519 | a stack reference can not alias a parameter, and a stack reference | |
1520 | can not alias a global. */ | |
1521 | if ((GET_CODE (x_base) == ADDRESS && GET_MODE (x_base) == Pmode) | |
1522 | || (GET_CODE (y_base) == ADDRESS && GET_MODE (y_base) == Pmode)) | |
1523 | return 0; | |
1524 | ||
1525 | if (! flag_argument_noalias) | |
1526 | return 1; | |
1527 | ||
1528 | if (flag_argument_noalias > 1) | |
1529 | return 0; | |
1530 | ||
ec5c56db | 1531 | /* Weak noalias assertion (arguments are distinct, but may match globals). */ |
9ae8ffe7 JL |
1532 | return ! (GET_MODE (x_base) == VOIDmode && GET_MODE (y_base) == VOIDmode); |
1533 | } | |
1534 | ||
eab5c70a BS |
1535 | /* Convert the address X into something we can use. This is done by returning |
1536 | it unchanged unless it is a value; in the latter case we call cselib to get | |
1537 | a more useful rtx. */ | |
3bdf5ad1 | 1538 | |
a13d4ebf | 1539 | rtx |
4682ae04 | 1540 | get_addr (rtx x) |
eab5c70a BS |
1541 | { |
1542 | cselib_val *v; | |
1543 | struct elt_loc_list *l; | |
1544 | ||
1545 | if (GET_CODE (x) != VALUE) | |
1546 | return x; | |
1547 | v = CSELIB_VAL_PTR (x); | |
40e02b4a JH |
1548 | if (v) |
1549 | { | |
1550 | for (l = v->locs; l; l = l->next) | |
1551 | if (CONSTANT_P (l->loc)) | |
1552 | return l->loc; | |
1553 | for (l = v->locs; l; l = l->next) | |
3c0cb5de | 1554 | if (!REG_P (l->loc) && !MEM_P (l->loc)) |
40e02b4a JH |
1555 | return l->loc; |
1556 | if (v->locs) | |
1557 | return v->locs->loc; | |
1558 | } | |
eab5c70a BS |
1559 | return x; |
1560 | } | |
1561 | ||
39cec1ac MH |
1562 | /* Return the address of the (N_REFS + 1)th memory reference to ADDR |
1563 | where SIZE is the size in bytes of the memory reference. If ADDR | |
1564 | is not modified by the memory reference then ADDR is returned. */ | |
1565 | ||
04e2b4d3 | 1566 | static rtx |
4682ae04 | 1567 | addr_side_effect_eval (rtx addr, int size, int n_refs) |
39cec1ac MH |
1568 | { |
1569 | int offset = 0; | |
ca7fd9cd | 1570 | |
39cec1ac MH |
1571 | switch (GET_CODE (addr)) |
1572 | { | |
1573 | case PRE_INC: | |
1574 | offset = (n_refs + 1) * size; | |
1575 | break; | |
1576 | case PRE_DEC: | |
1577 | offset = -(n_refs + 1) * size; | |
1578 | break; | |
1579 | case POST_INC: | |
1580 | offset = n_refs * size; | |
1581 | break; | |
1582 | case POST_DEC: | |
1583 | offset = -n_refs * size; | |
1584 | break; | |
1585 | ||
1586 | default: | |
1587 | return addr; | |
1588 | } | |
ca7fd9cd | 1589 | |
39cec1ac | 1590 | if (offset) |
45183e03 JH |
1591 | addr = gen_rtx_PLUS (GET_MODE (addr), XEXP (addr, 0), |
1592 | GEN_INT (offset)); | |
39cec1ac MH |
1593 | else |
1594 | addr = XEXP (addr, 0); | |
45183e03 | 1595 | addr = canon_rtx (addr); |
39cec1ac MH |
1596 | |
1597 | return addr; | |
1598 | } | |
1599 | ||
9ae8ffe7 JL |
1600 | /* Return nonzero if X and Y (memory addresses) could reference the |
1601 | same location in memory. C is an offset accumulator. When | |
1602 | C is nonzero, we are testing aliases between X and Y + C. | |
1603 | XSIZE is the size in bytes of the X reference, | |
1604 | similarly YSIZE is the size in bytes for Y. | |
45183e03 | 1605 | Expect that canon_rtx has been already called for X and Y. |
9ae8ffe7 JL |
1606 | |
1607 | If XSIZE or YSIZE is zero, we do not know the amount of memory being | |
1608 | referenced (the reference was BLKmode), so make the most pessimistic | |
1609 | assumptions. | |
1610 | ||
c02f035f RH |
1611 | If XSIZE or YSIZE is negative, we may access memory outside the object |
1612 | being referenced as a side effect. This can happen when using AND to | |
1613 | align memory references, as is done on the Alpha. | |
1614 | ||
9ae8ffe7 | 1615 | Nice to notice that varying addresses cannot conflict with fp if no |
0211b6ab | 1616 | local variables had their addresses taken, but that's too hard now. */ |
9ae8ffe7 | 1617 | |
9ae8ffe7 | 1618 | static int |
4682ae04 | 1619 | memrefs_conflict_p (int xsize, rtx x, int ysize, rtx y, HOST_WIDE_INT c) |
9ae8ffe7 | 1620 | { |
eab5c70a BS |
1621 | if (GET_CODE (x) == VALUE) |
1622 | x = get_addr (x); | |
1623 | if (GET_CODE (y) == VALUE) | |
1624 | y = get_addr (y); | |
9ae8ffe7 JL |
1625 | if (GET_CODE (x) == HIGH) |
1626 | x = XEXP (x, 0); | |
1627 | else if (GET_CODE (x) == LO_SUM) | |
1628 | x = XEXP (x, 1); | |
1629 | else | |
45183e03 | 1630 | x = addr_side_effect_eval (x, xsize, 0); |
9ae8ffe7 JL |
1631 | if (GET_CODE (y) == HIGH) |
1632 | y = XEXP (y, 0); | |
1633 | else if (GET_CODE (y) == LO_SUM) | |
1634 | y = XEXP (y, 1); | |
1635 | else | |
45183e03 | 1636 | y = addr_side_effect_eval (y, ysize, 0); |
9ae8ffe7 JL |
1637 | |
1638 | if (rtx_equal_for_memref_p (x, y)) | |
1639 | { | |
c02f035f | 1640 | if (xsize <= 0 || ysize <= 0) |
9ae8ffe7 JL |
1641 | return 1; |
1642 | if (c >= 0 && xsize > c) | |
1643 | return 1; | |
1644 | if (c < 0 && ysize+c > 0) | |
1645 | return 1; | |
1646 | return 0; | |
1647 | } | |
1648 | ||
6e73e666 JC |
1649 | /* This code used to check for conflicts involving stack references and |
1650 | globals but the base address alias code now handles these cases. */ | |
9ae8ffe7 JL |
1651 | |
1652 | if (GET_CODE (x) == PLUS) | |
1653 | { | |
1654 | /* The fact that X is canonicalized means that this | |
1655 | PLUS rtx is canonicalized. */ | |
1656 | rtx x0 = XEXP (x, 0); | |
1657 | rtx x1 = XEXP (x, 1); | |
1658 | ||
1659 | if (GET_CODE (y) == PLUS) | |
1660 | { | |
1661 | /* The fact that Y is canonicalized means that this | |
1662 | PLUS rtx is canonicalized. */ | |
1663 | rtx y0 = XEXP (y, 0); | |
1664 | rtx y1 = XEXP (y, 1); | |
1665 | ||
1666 | if (rtx_equal_for_memref_p (x1, y1)) | |
1667 | return memrefs_conflict_p (xsize, x0, ysize, y0, c); | |
1668 | if (rtx_equal_for_memref_p (x0, y0)) | |
1669 | return memrefs_conflict_p (xsize, x1, ysize, y1, c); | |
1670 | if (GET_CODE (x1) == CONST_INT) | |
63be02db JM |
1671 | { |
1672 | if (GET_CODE (y1) == CONST_INT) | |
1673 | return memrefs_conflict_p (xsize, x0, ysize, y0, | |
1674 | c - INTVAL (x1) + INTVAL (y1)); | |
1675 | else | |
1676 | return memrefs_conflict_p (xsize, x0, ysize, y, | |
1677 | c - INTVAL (x1)); | |
1678 | } | |
9ae8ffe7 JL |
1679 | else if (GET_CODE (y1) == CONST_INT) |
1680 | return memrefs_conflict_p (xsize, x, ysize, y0, c + INTVAL (y1)); | |
1681 | ||
6e73e666 | 1682 | return 1; |
9ae8ffe7 JL |
1683 | } |
1684 | else if (GET_CODE (x1) == CONST_INT) | |
1685 | return memrefs_conflict_p (xsize, x0, ysize, y, c - INTVAL (x1)); | |
1686 | } | |
1687 | else if (GET_CODE (y) == PLUS) | |
1688 | { | |
1689 | /* The fact that Y is canonicalized means that this | |
1690 | PLUS rtx is canonicalized. */ | |
1691 | rtx y0 = XEXP (y, 0); | |
1692 | rtx y1 = XEXP (y, 1); | |
1693 | ||
1694 | if (GET_CODE (y1) == CONST_INT) | |
1695 | return memrefs_conflict_p (xsize, x, ysize, y0, c + INTVAL (y1)); | |
1696 | else | |
1697 | return 1; | |
1698 | } | |
1699 | ||
1700 | if (GET_CODE (x) == GET_CODE (y)) | |
1701 | switch (GET_CODE (x)) | |
1702 | { | |
1703 | case MULT: | |
1704 | { | |
1705 | /* Handle cases where we expect the second operands to be the | |
1706 | same, and check only whether the first operand would conflict | |
1707 | or not. */ | |
1708 | rtx x0, y0; | |
1709 | rtx x1 = canon_rtx (XEXP (x, 1)); | |
1710 | rtx y1 = canon_rtx (XEXP (y, 1)); | |
1711 | if (! rtx_equal_for_memref_p (x1, y1)) | |
1712 | return 1; | |
1713 | x0 = canon_rtx (XEXP (x, 0)); | |
1714 | y0 = canon_rtx (XEXP (y, 0)); | |
1715 | if (rtx_equal_for_memref_p (x0, y0)) | |
1716 | return (xsize == 0 || ysize == 0 | |
1717 | || (c >= 0 && xsize > c) || (c < 0 && ysize+c > 0)); | |
1718 | ||
1719 | /* Can't properly adjust our sizes. */ | |
1720 | if (GET_CODE (x1) != CONST_INT) | |
1721 | return 1; | |
1722 | xsize /= INTVAL (x1); | |
1723 | ysize /= INTVAL (x1); | |
1724 | c /= INTVAL (x1); | |
1725 | return memrefs_conflict_p (xsize, x0, ysize, y0, c); | |
1726 | } | |
1d300e19 | 1727 | |
de12be17 JC |
1728 | case REG: |
1729 | /* Are these registers known not to be equal? */ | |
1730 | if (alias_invariant) | |
1731 | { | |
e51712db | 1732 | unsigned int r_x = REGNO (x), r_y = REGNO (y); |
de12be17 JC |
1733 | rtx i_x, i_y; /* invariant relationships of X and Y */ |
1734 | ||
c582d54a JH |
1735 | i_x = r_x >= alias_invariant_size ? 0 : alias_invariant[r_x]; |
1736 | i_y = r_y >= alias_invariant_size ? 0 : alias_invariant[r_y]; | |
de12be17 JC |
1737 | |
1738 | if (i_x == 0 && i_y == 0) | |
1739 | break; | |
1740 | ||
1741 | if (! memrefs_conflict_p (xsize, i_x ? i_x : x, | |
1742 | ysize, i_y ? i_y : y, c)) | |
1743 | return 0; | |
1744 | } | |
1745 | break; | |
1746 | ||
1d300e19 KG |
1747 | default: |
1748 | break; | |
9ae8ffe7 JL |
1749 | } |
1750 | ||
1751 | /* Treat an access through an AND (e.g. a subword access on an Alpha) | |
ca7fd9cd | 1752 | as an access with indeterminate size. Assume that references |
56ee9281 RH |
1753 | besides AND are aligned, so if the size of the other reference is |
1754 | at least as large as the alignment, assume no other overlap. */ | |
9ae8ffe7 | 1755 | if (GET_CODE (x) == AND && GET_CODE (XEXP (x, 1)) == CONST_INT) |
56ee9281 | 1756 | { |
02e3377d | 1757 | if (GET_CODE (y) == AND || ysize < -INTVAL (XEXP (x, 1))) |
56ee9281 | 1758 | xsize = -1; |
45183e03 | 1759 | return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)), ysize, y, c); |
56ee9281 | 1760 | } |
9ae8ffe7 | 1761 | if (GET_CODE (y) == AND && GET_CODE (XEXP (y, 1)) == CONST_INT) |
c02f035f | 1762 | { |
56ee9281 | 1763 | /* ??? If we are indexing far enough into the array/structure, we |
ca7fd9cd | 1764 | may yet be able to determine that we can not overlap. But we |
c02f035f | 1765 | also need to that we are far enough from the end not to overlap |
56ee9281 | 1766 | a following reference, so we do nothing with that for now. */ |
02e3377d | 1767 | if (GET_CODE (x) == AND || xsize < -INTVAL (XEXP (y, 1))) |
56ee9281 | 1768 | ysize = -1; |
45183e03 | 1769 | return memrefs_conflict_p (xsize, x, ysize, canon_rtx (XEXP (y, 0)), c); |
c02f035f | 1770 | } |
9ae8ffe7 JL |
1771 | |
1772 | if (CONSTANT_P (x)) | |
1773 | { | |
1774 | if (GET_CODE (x) == CONST_INT && GET_CODE (y) == CONST_INT) | |
1775 | { | |
1776 | c += (INTVAL (y) - INTVAL (x)); | |
c02f035f | 1777 | return (xsize <= 0 || ysize <= 0 |
9ae8ffe7 JL |
1778 | || (c >= 0 && xsize > c) || (c < 0 && ysize+c > 0)); |
1779 | } | |
1780 | ||
1781 | if (GET_CODE (x) == CONST) | |
1782 | { | |
1783 | if (GET_CODE (y) == CONST) | |
1784 | return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)), | |
1785 | ysize, canon_rtx (XEXP (y, 0)), c); | |
1786 | else | |
1787 | return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)), | |
1788 | ysize, y, c); | |
1789 | } | |
1790 | if (GET_CODE (y) == CONST) | |
1791 | return memrefs_conflict_p (xsize, x, ysize, | |
1792 | canon_rtx (XEXP (y, 0)), c); | |
1793 | ||
1794 | if (CONSTANT_P (y)) | |
b949ea8b | 1795 | return (xsize <= 0 || ysize <= 0 |
c02f035f | 1796 | || (rtx_equal_for_memref_p (x, y) |
b949ea8b | 1797 | && ((c >= 0 && xsize > c) || (c < 0 && ysize+c > 0)))); |
9ae8ffe7 JL |
1798 | |
1799 | return 1; | |
1800 | } | |
1801 | return 1; | |
1802 | } | |
1803 | ||
1804 | /* Functions to compute memory dependencies. | |
1805 | ||
1806 | Since we process the insns in execution order, we can build tables | |
1807 | to keep track of what registers are fixed (and not aliased), what registers | |
1808 | are varying in known ways, and what registers are varying in unknown | |
1809 | ways. | |
1810 | ||
1811 | If both memory references are volatile, then there must always be a | |
1812 | dependence between the two references, since their order can not be | |
1813 | changed. A volatile and non-volatile reference can be interchanged | |
ca7fd9cd | 1814 | though. |
9ae8ffe7 | 1815 | |
dc1618bc RK |
1816 | A MEM_IN_STRUCT reference at a non-AND varying address can never |
1817 | conflict with a non-MEM_IN_STRUCT reference at a fixed address. We | |
1818 | also must allow AND addresses, because they may generate accesses | |
1819 | outside the object being referenced. This is used to generate | |
1820 | aligned addresses from unaligned addresses, for instance, the alpha | |
1821 | storeqi_unaligned pattern. */ | |
9ae8ffe7 JL |
1822 | |
1823 | /* Read dependence: X is read after read in MEM takes place. There can | |
1824 | only be a dependence here if both reads are volatile. */ | |
1825 | ||
1826 | int | |
4682ae04 | 1827 | read_dependence (rtx mem, rtx x) |
9ae8ffe7 JL |
1828 | { |
1829 | return MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem); | |
1830 | } | |
1831 | ||
c6df88cb MM |
1832 | /* Returns MEM1 if and only if MEM1 is a scalar at a fixed address and |
1833 | MEM2 is a reference to a structure at a varying address, or returns | |
1834 | MEM2 if vice versa. Otherwise, returns NULL_RTX. If a non-NULL | |
1835 | value is returned MEM1 and MEM2 can never alias. VARIES_P is used | |
1836 | to decide whether or not an address may vary; it should return | |
eab5c70a BS |
1837 | nonzero whenever variation is possible. |
1838 | MEM1_ADDR and MEM2_ADDR are the addresses of MEM1 and MEM2. */ | |
ca7fd9cd | 1839 | |
2c72b78f | 1840 | static rtx |
4682ae04 AJ |
1841 | fixed_scalar_and_varying_struct_p (rtx mem1, rtx mem2, rtx mem1_addr, |
1842 | rtx mem2_addr, | |
1843 | int (*varies_p) (rtx, int)) | |
ca7fd9cd | 1844 | { |
3e0abe15 GK |
1845 | if (! flag_strict_aliasing) |
1846 | return NULL_RTX; | |
1847 | ||
ca7fd9cd | 1848 | if (MEM_SCALAR_P (mem1) && MEM_IN_STRUCT_P (mem2) |
e38fe8e0 | 1849 | && !varies_p (mem1_addr, 1) && varies_p (mem2_addr, 1)) |
c6df88cb MM |
1850 | /* MEM1 is a scalar at a fixed address; MEM2 is a struct at a |
1851 | varying address. */ | |
1852 | return mem1; | |
1853 | ||
ca7fd9cd | 1854 | if (MEM_IN_STRUCT_P (mem1) && MEM_SCALAR_P (mem2) |
e38fe8e0 | 1855 | && varies_p (mem1_addr, 1) && !varies_p (mem2_addr, 1)) |
c6df88cb MM |
1856 | /* MEM2 is a scalar at a fixed address; MEM1 is a struct at a |
1857 | varying address. */ | |
1858 | return mem2; | |
1859 | ||
1860 | return NULL_RTX; | |
1861 | } | |
1862 | ||
1863 | /* Returns nonzero if something about the mode or address format MEM1 | |
1864 | indicates that it might well alias *anything*. */ | |
1865 | ||
2c72b78f | 1866 | static int |
4682ae04 | 1867 | aliases_everything_p (rtx mem) |
c6df88cb | 1868 | { |
c6df88cb MM |
1869 | if (GET_CODE (XEXP (mem, 0)) == AND) |
1870 | /* If the address is an AND, its very hard to know at what it is | |
1871 | actually pointing. */ | |
1872 | return 1; | |
ca7fd9cd | 1873 | |
c6df88cb MM |
1874 | return 0; |
1875 | } | |
1876 | ||
998d7deb RH |
1877 | /* Return true if we can determine that the fields referenced cannot |
1878 | overlap for any pair of objects. */ | |
1879 | ||
1880 | static bool | |
4682ae04 | 1881 | nonoverlapping_component_refs_p (tree x, tree y) |
998d7deb RH |
1882 | { |
1883 | tree fieldx, fieldy, typex, typey, orig_y; | |
1884 | ||
1885 | do | |
1886 | { | |
1887 | /* The comparison has to be done at a common type, since we don't | |
d6a7951f | 1888 | know how the inheritance hierarchy works. */ |
998d7deb RH |
1889 | orig_y = y; |
1890 | do | |
1891 | { | |
1892 | fieldx = TREE_OPERAND (x, 1); | |
1893 | typex = DECL_FIELD_CONTEXT (fieldx); | |
1894 | ||
1895 | y = orig_y; | |
1896 | do | |
1897 | { | |
1898 | fieldy = TREE_OPERAND (y, 1); | |
1899 | typey = DECL_FIELD_CONTEXT (fieldy); | |
1900 | ||
1901 | if (typex == typey) | |
1902 | goto found; | |
1903 | ||
1904 | y = TREE_OPERAND (y, 0); | |
1905 | } | |
1906 | while (y && TREE_CODE (y) == COMPONENT_REF); | |
1907 | ||
1908 | x = TREE_OPERAND (x, 0); | |
1909 | } | |
1910 | while (x && TREE_CODE (x) == COMPONENT_REF); | |
1911 | ||
1912 | /* Never found a common type. */ | |
1913 | return false; | |
1914 | ||
1915 | found: | |
1916 | /* If we're left with accessing different fields of a structure, | |
1917 | then no overlap. */ | |
1918 | if (TREE_CODE (typex) == RECORD_TYPE | |
1919 | && fieldx != fieldy) | |
1920 | return true; | |
1921 | ||
1922 | /* The comparison on the current field failed. If we're accessing | |
1923 | a very nested structure, look at the next outer level. */ | |
1924 | x = TREE_OPERAND (x, 0); | |
1925 | y = TREE_OPERAND (y, 0); | |
1926 | } | |
1927 | while (x && y | |
1928 | && TREE_CODE (x) == COMPONENT_REF | |
1929 | && TREE_CODE (y) == COMPONENT_REF); | |
ca7fd9cd | 1930 | |
998d7deb RH |
1931 | return false; |
1932 | } | |
1933 | ||
1934 | /* Look at the bottom of the COMPONENT_REF list for a DECL, and return it. */ | |
1935 | ||
1936 | static tree | |
4682ae04 | 1937 | decl_for_component_ref (tree x) |
998d7deb RH |
1938 | { |
1939 | do | |
1940 | { | |
1941 | x = TREE_OPERAND (x, 0); | |
1942 | } | |
1943 | while (x && TREE_CODE (x) == COMPONENT_REF); | |
1944 | ||
1945 | return x && DECL_P (x) ? x : NULL_TREE; | |
1946 | } | |
1947 | ||
1948 | /* Walk up the COMPONENT_REF list and adjust OFFSET to compensate for the | |
1949 | offset of the field reference. */ | |
1950 | ||
1951 | static rtx | |
4682ae04 | 1952 | adjust_offset_for_component_ref (tree x, rtx offset) |
998d7deb RH |
1953 | { |
1954 | HOST_WIDE_INT ioffset; | |
1955 | ||
1956 | if (! offset) | |
1957 | return NULL_RTX; | |
1958 | ||
1959 | ioffset = INTVAL (offset); | |
ca7fd9cd | 1960 | do |
998d7deb | 1961 | { |
44de5aeb | 1962 | tree offset = component_ref_field_offset (x); |
998d7deb RH |
1963 | tree field = TREE_OPERAND (x, 1); |
1964 | ||
44de5aeb | 1965 | if (! host_integerp (offset, 1)) |
998d7deb | 1966 | return NULL_RTX; |
44de5aeb | 1967 | ioffset += (tree_low_cst (offset, 1) |
998d7deb RH |
1968 | + (tree_low_cst (DECL_FIELD_BIT_OFFSET (field), 1) |
1969 | / BITS_PER_UNIT)); | |
1970 | ||
1971 | x = TREE_OPERAND (x, 0); | |
1972 | } | |
1973 | while (x && TREE_CODE (x) == COMPONENT_REF); | |
1974 | ||
1975 | return GEN_INT (ioffset); | |
1976 | } | |
1977 | ||
95bd1dd7 | 1978 | /* Return nonzero if we can determine the exprs corresponding to memrefs |
a4311dfe RK |
1979 | X and Y and they do not overlap. */ |
1980 | ||
1981 | static int | |
4682ae04 | 1982 | nonoverlapping_memrefs_p (rtx x, rtx y) |
a4311dfe | 1983 | { |
998d7deb | 1984 | tree exprx = MEM_EXPR (x), expry = MEM_EXPR (y); |
a4311dfe RK |
1985 | rtx rtlx, rtly; |
1986 | rtx basex, basey; | |
998d7deb | 1987 | rtx moffsetx, moffsety; |
a4311dfe RK |
1988 | HOST_WIDE_INT offsetx = 0, offsety = 0, sizex, sizey, tem; |
1989 | ||
998d7deb RH |
1990 | /* Unless both have exprs, we can't tell anything. */ |
1991 | if (exprx == 0 || expry == 0) | |
1992 | return 0; | |
1993 | ||
1994 | /* If both are field references, we may be able to determine something. */ | |
1995 | if (TREE_CODE (exprx) == COMPONENT_REF | |
1996 | && TREE_CODE (expry) == COMPONENT_REF | |
1997 | && nonoverlapping_component_refs_p (exprx, expry)) | |
1998 | return 1; | |
1999 | ||
2000 | /* If the field reference test failed, look at the DECLs involved. */ | |
2001 | moffsetx = MEM_OFFSET (x); | |
2002 | if (TREE_CODE (exprx) == COMPONENT_REF) | |
2003 | { | |
2004 | tree t = decl_for_component_ref (exprx); | |
2005 | if (! t) | |
2006 | return 0; | |
2007 | moffsetx = adjust_offset_for_component_ref (exprx, moffsetx); | |
2008 | exprx = t; | |
2009 | } | |
1b096a0a | 2010 | else if (INDIRECT_REF_P (exprx)) |
c67a1cf6 RH |
2011 | { |
2012 | exprx = TREE_OPERAND (exprx, 0); | |
2013 | if (flag_argument_noalias < 2 | |
2014 | || TREE_CODE (exprx) != PARM_DECL) | |
2015 | return 0; | |
2016 | } | |
2017 | ||
998d7deb RH |
2018 | moffsety = MEM_OFFSET (y); |
2019 | if (TREE_CODE (expry) == COMPONENT_REF) | |
2020 | { | |
2021 | tree t = decl_for_component_ref (expry); | |
2022 | if (! t) | |
2023 | return 0; | |
2024 | moffsety = adjust_offset_for_component_ref (expry, moffsety); | |
2025 | expry = t; | |
2026 | } | |
1b096a0a | 2027 | else if (INDIRECT_REF_P (expry)) |
c67a1cf6 RH |
2028 | { |
2029 | expry = TREE_OPERAND (expry, 0); | |
2030 | if (flag_argument_noalias < 2 | |
2031 | || TREE_CODE (expry) != PARM_DECL) | |
2032 | return 0; | |
2033 | } | |
998d7deb RH |
2034 | |
2035 | if (! DECL_P (exprx) || ! DECL_P (expry)) | |
a4311dfe RK |
2036 | return 0; |
2037 | ||
998d7deb RH |
2038 | rtlx = DECL_RTL (exprx); |
2039 | rtly = DECL_RTL (expry); | |
a4311dfe | 2040 | |
1edcd60b RK |
2041 | /* If either RTL is not a MEM, it must be a REG or CONCAT, meaning they |
2042 | can't overlap unless they are the same because we never reuse that part | |
2043 | of the stack frame used for locals for spilled pseudos. */ | |
3c0cb5de | 2044 | if ((!MEM_P (rtlx) || !MEM_P (rtly)) |
1edcd60b | 2045 | && ! rtx_equal_p (rtlx, rtly)) |
a4311dfe RK |
2046 | return 1; |
2047 | ||
2048 | /* Get the base and offsets of both decls. If either is a register, we | |
2049 | know both are and are the same, so use that as the base. The only | |
2050 | we can avoid overlap is if we can deduce that they are nonoverlapping | |
2051 | pieces of that decl, which is very rare. */ | |
3c0cb5de | 2052 | basex = MEM_P (rtlx) ? XEXP (rtlx, 0) : rtlx; |
a4311dfe RK |
2053 | if (GET_CODE (basex) == PLUS && GET_CODE (XEXP (basex, 1)) == CONST_INT) |
2054 | offsetx = INTVAL (XEXP (basex, 1)), basex = XEXP (basex, 0); | |
2055 | ||
3c0cb5de | 2056 | basey = MEM_P (rtly) ? XEXP (rtly, 0) : rtly; |
a4311dfe RK |
2057 | if (GET_CODE (basey) == PLUS && GET_CODE (XEXP (basey, 1)) == CONST_INT) |
2058 | offsety = INTVAL (XEXP (basey, 1)), basey = XEXP (basey, 0); | |
2059 | ||
d746694a | 2060 | /* If the bases are different, we know they do not overlap if both |
ca7fd9cd | 2061 | are constants or if one is a constant and the other a pointer into the |
d746694a RK |
2062 | stack frame. Otherwise a different base means we can't tell if they |
2063 | overlap or not. */ | |
2064 | if (! rtx_equal_p (basex, basey)) | |
ca7fd9cd KH |
2065 | return ((CONSTANT_P (basex) && CONSTANT_P (basey)) |
2066 | || (CONSTANT_P (basex) && REG_P (basey) | |
2067 | && REGNO_PTR_FRAME_P (REGNO (basey))) | |
2068 | || (CONSTANT_P (basey) && REG_P (basex) | |
2069 | && REGNO_PTR_FRAME_P (REGNO (basex)))); | |
a4311dfe | 2070 | |
3c0cb5de | 2071 | sizex = (!MEM_P (rtlx) ? (int) GET_MODE_SIZE (GET_MODE (rtlx)) |
a4311dfe RK |
2072 | : MEM_SIZE (rtlx) ? INTVAL (MEM_SIZE (rtlx)) |
2073 | : -1); | |
3c0cb5de | 2074 | sizey = (!MEM_P (rtly) ? (int) GET_MODE_SIZE (GET_MODE (rtly)) |
a4311dfe RK |
2075 | : MEM_SIZE (rtly) ? INTVAL (MEM_SIZE (rtly)) : |
2076 | -1); | |
2077 | ||
0af5bc3e RK |
2078 | /* If we have an offset for either memref, it can update the values computed |
2079 | above. */ | |
998d7deb RH |
2080 | if (moffsetx) |
2081 | offsetx += INTVAL (moffsetx), sizex -= INTVAL (moffsetx); | |
2082 | if (moffsety) | |
2083 | offsety += INTVAL (moffsety), sizey -= INTVAL (moffsety); | |
a4311dfe | 2084 | |
0af5bc3e | 2085 | /* If a memref has both a size and an offset, we can use the smaller size. |
efc981bb | 2086 | We can't do this if the offset isn't known because we must view this |
0af5bc3e | 2087 | memref as being anywhere inside the DECL's MEM. */ |
998d7deb | 2088 | if (MEM_SIZE (x) && moffsetx) |
a4311dfe | 2089 | sizex = INTVAL (MEM_SIZE (x)); |
998d7deb | 2090 | if (MEM_SIZE (y) && moffsety) |
a4311dfe RK |
2091 | sizey = INTVAL (MEM_SIZE (y)); |
2092 | ||
2093 | /* Put the values of the memref with the lower offset in X's values. */ | |
2094 | if (offsetx > offsety) | |
2095 | { | |
2096 | tem = offsetx, offsetx = offsety, offsety = tem; | |
2097 | tem = sizex, sizex = sizey, sizey = tem; | |
2098 | } | |
2099 | ||
2100 | /* If we don't know the size of the lower-offset value, we can't tell | |
2101 | if they conflict. Otherwise, we do the test. */ | |
a6f7c915 | 2102 | return sizex >= 0 && offsety >= offsetx + sizex; |
a4311dfe RK |
2103 | } |
2104 | ||
9ae8ffe7 JL |
2105 | /* True dependence: X is read after store in MEM takes place. */ |
2106 | ||
2107 | int | |
4682ae04 AJ |
2108 | true_dependence (rtx mem, enum machine_mode mem_mode, rtx x, |
2109 | int (*varies) (rtx, int)) | |
9ae8ffe7 | 2110 | { |
b3694847 | 2111 | rtx x_addr, mem_addr; |
49982682 | 2112 | rtx base; |
9ae8ffe7 JL |
2113 | |
2114 | if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) | |
2115 | return 1; | |
2116 | ||
c4484b8f RH |
2117 | /* (mem:BLK (scratch)) is a special mechanism to conflict with everything. |
2118 | This is used in epilogue deallocation functions. */ | |
2119 | if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH) | |
2120 | return 1; | |
2121 | if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH) | |
2122 | return 1; | |
2123 | ||
41472af8 MM |
2124 | if (DIFFERENT_ALIAS_SETS_P (x, mem)) |
2125 | return 0; | |
2126 | ||
389fdba0 RH |
2127 | /* Read-only memory is by definition never modified, and therefore can't |
2128 | conflict with anything. We don't expect to find read-only set on MEM, | |
2129 | but stupid user tricks can produce them, so don't abort. */ | |
2130 | if (MEM_READONLY_P (x)) | |
9ae8ffe7 JL |
2131 | return 0; |
2132 | ||
a4311dfe RK |
2133 | if (nonoverlapping_memrefs_p (mem, x)) |
2134 | return 0; | |
2135 | ||
56ee9281 RH |
2136 | if (mem_mode == VOIDmode) |
2137 | mem_mode = GET_MODE (mem); | |
2138 | ||
eab5c70a BS |
2139 | x_addr = get_addr (XEXP (x, 0)); |
2140 | mem_addr = get_addr (XEXP (mem, 0)); | |
2141 | ||
55efb413 JW |
2142 | base = find_base_term (x_addr); |
2143 | if (base && (GET_CODE (base) == LABEL_REF | |
2144 | || (GET_CODE (base) == SYMBOL_REF | |
2145 | && CONSTANT_POOL_ADDRESS_P (base)))) | |
2146 | return 0; | |
2147 | ||
eab5c70a | 2148 | if (! base_alias_check (x_addr, mem_addr, GET_MODE (x), mem_mode)) |
1c72c7f6 JC |
2149 | return 0; |
2150 | ||
eab5c70a BS |
2151 | x_addr = canon_rtx (x_addr); |
2152 | mem_addr = canon_rtx (mem_addr); | |
6e73e666 | 2153 | |
0211b6ab JW |
2154 | if (! memrefs_conflict_p (GET_MODE_SIZE (mem_mode), mem_addr, |
2155 | SIZE_FOR_MODE (x), x_addr, 0)) | |
2156 | return 0; | |
2157 | ||
c6df88cb | 2158 | if (aliases_everything_p (x)) |
0211b6ab JW |
2159 | return 1; |
2160 | ||
f5143c46 | 2161 | /* We cannot use aliases_everything_p to test MEM, since we must look |
c6df88cb MM |
2162 | at MEM_MODE, rather than GET_MODE (MEM). */ |
2163 | if (mem_mode == QImode || GET_CODE (mem_addr) == AND) | |
a13d4ebf AM |
2164 | return 1; |
2165 | ||
2166 | /* In true_dependence we also allow BLKmode to alias anything. Why | |
2167 | don't we do this in anti_dependence and output_dependence? */ | |
2168 | if (mem_mode == BLKmode || GET_MODE (x) == BLKmode) | |
2169 | return 1; | |
2170 | ||
2171 | return ! fixed_scalar_and_varying_struct_p (mem, x, mem_addr, x_addr, | |
2172 | varies); | |
2173 | } | |
2174 | ||
2175 | /* Canonical true dependence: X is read after store in MEM takes place. | |
ca7fd9cd KH |
2176 | Variant of true_dependence which assumes MEM has already been |
2177 | canonicalized (hence we no longer do that here). | |
2178 | The mem_addr argument has been added, since true_dependence computed | |
a13d4ebf AM |
2179 | this value prior to canonicalizing. */ |
2180 | ||
2181 | int | |
4682ae04 AJ |
2182 | canon_true_dependence (rtx mem, enum machine_mode mem_mode, rtx mem_addr, |
2183 | rtx x, int (*varies) (rtx, int)) | |
a13d4ebf | 2184 | { |
b3694847 | 2185 | rtx x_addr; |
a13d4ebf AM |
2186 | |
2187 | if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) | |
2188 | return 1; | |
2189 | ||
0fe854a7 RH |
2190 | /* (mem:BLK (scratch)) is a special mechanism to conflict with everything. |
2191 | This is used in epilogue deallocation functions. */ | |
2192 | if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH) | |
2193 | return 1; | |
2194 | if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH) | |
2195 | return 1; | |
2196 | ||
a13d4ebf AM |
2197 | if (DIFFERENT_ALIAS_SETS_P (x, mem)) |
2198 | return 0; | |
2199 | ||
389fdba0 RH |
2200 | /* Read-only memory is by definition never modified, and therefore can't |
2201 | conflict with anything. We don't expect to find read-only set on MEM, | |
2202 | but stupid user tricks can produce them, so don't abort. */ | |
2203 | if (MEM_READONLY_P (x)) | |
a13d4ebf AM |
2204 | return 0; |
2205 | ||
a4311dfe RK |
2206 | if (nonoverlapping_memrefs_p (x, mem)) |
2207 | return 0; | |
2208 | ||
a13d4ebf AM |
2209 | x_addr = get_addr (XEXP (x, 0)); |
2210 | ||
2211 | if (! base_alias_check (x_addr, mem_addr, GET_MODE (x), mem_mode)) | |
2212 | return 0; | |
2213 | ||
2214 | x_addr = canon_rtx (x_addr); | |
2215 | if (! memrefs_conflict_p (GET_MODE_SIZE (mem_mode), mem_addr, | |
2216 | SIZE_FOR_MODE (x), x_addr, 0)) | |
2217 | return 0; | |
2218 | ||
2219 | if (aliases_everything_p (x)) | |
2220 | return 1; | |
2221 | ||
f5143c46 | 2222 | /* We cannot use aliases_everything_p to test MEM, since we must look |
a13d4ebf AM |
2223 | at MEM_MODE, rather than GET_MODE (MEM). */ |
2224 | if (mem_mode == QImode || GET_CODE (mem_addr) == AND) | |
c6df88cb | 2225 | return 1; |
0211b6ab | 2226 | |
c6df88cb MM |
2227 | /* In true_dependence we also allow BLKmode to alias anything. Why |
2228 | don't we do this in anti_dependence and output_dependence? */ | |
2229 | if (mem_mode == BLKmode || GET_MODE (x) == BLKmode) | |
2230 | return 1; | |
0211b6ab | 2231 | |
eab5c70a BS |
2232 | return ! fixed_scalar_and_varying_struct_p (mem, x, mem_addr, x_addr, |
2233 | varies); | |
9ae8ffe7 JL |
2234 | } |
2235 | ||
da7d8304 | 2236 | /* Returns nonzero if a write to X might alias a previous read from |
389fdba0 | 2237 | (or, if WRITEP is nonzero, a write to) MEM. */ |
9ae8ffe7 | 2238 | |
2c72b78f | 2239 | static int |
389fdba0 | 2240 | write_dependence_p (rtx mem, rtx x, int writep) |
9ae8ffe7 | 2241 | { |
6e73e666 | 2242 | rtx x_addr, mem_addr; |
c6df88cb | 2243 | rtx fixed_scalar; |
49982682 | 2244 | rtx base; |
6e73e666 | 2245 | |
9ae8ffe7 JL |
2246 | if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) |
2247 | return 1; | |
2248 | ||
c4484b8f RH |
2249 | /* (mem:BLK (scratch)) is a special mechanism to conflict with everything. |
2250 | This is used in epilogue deallocation functions. */ | |
2251 | if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH) | |
2252 | return 1; | |
2253 | if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH) | |
2254 | return 1; | |
2255 | ||
eab5c70a BS |
2256 | if (DIFFERENT_ALIAS_SETS_P (x, mem)) |
2257 | return 0; | |
2258 | ||
389fdba0 RH |
2259 | /* A read from read-only memory can't conflict with read-write memory. */ |
2260 | if (!writep && MEM_READONLY_P (mem)) | |
2261 | return 0; | |
55efb413 | 2262 | |
a4311dfe RK |
2263 | if (nonoverlapping_memrefs_p (x, mem)) |
2264 | return 0; | |
2265 | ||
55efb413 JW |
2266 | x_addr = get_addr (XEXP (x, 0)); |
2267 | mem_addr = get_addr (XEXP (mem, 0)); | |
2268 | ||
49982682 JW |
2269 | if (! writep) |
2270 | { | |
55efb413 | 2271 | base = find_base_term (mem_addr); |
49982682 JW |
2272 | if (base && (GET_CODE (base) == LABEL_REF |
2273 | || (GET_CODE (base) == SYMBOL_REF | |
2274 | && CONSTANT_POOL_ADDRESS_P (base)))) | |
2275 | return 0; | |
2276 | } | |
2277 | ||
eab5c70a BS |
2278 | if (! base_alias_check (x_addr, mem_addr, GET_MODE (x), |
2279 | GET_MODE (mem))) | |
41472af8 MM |
2280 | return 0; |
2281 | ||
eab5c70a BS |
2282 | x_addr = canon_rtx (x_addr); |
2283 | mem_addr = canon_rtx (mem_addr); | |
6e73e666 | 2284 | |
c6df88cb MM |
2285 | if (!memrefs_conflict_p (SIZE_FOR_MODE (mem), mem_addr, |
2286 | SIZE_FOR_MODE (x), x_addr, 0)) | |
2287 | return 0; | |
2288 | ||
ca7fd9cd | 2289 | fixed_scalar |
eab5c70a BS |
2290 | = fixed_scalar_and_varying_struct_p (mem, x, mem_addr, x_addr, |
2291 | rtx_addr_varies_p); | |
2292 | ||
c6df88cb MM |
2293 | return (!(fixed_scalar == mem && !aliases_everything_p (x)) |
2294 | && !(fixed_scalar == x && !aliases_everything_p (mem))); | |
2295 | } | |
2296 | ||
2297 | /* Anti dependence: X is written after read in MEM takes place. */ | |
2298 | ||
2299 | int | |
4682ae04 | 2300 | anti_dependence (rtx mem, rtx x) |
c6df88cb | 2301 | { |
389fdba0 | 2302 | return write_dependence_p (mem, x, /*writep=*/0); |
9ae8ffe7 JL |
2303 | } |
2304 | ||
2305 | /* Output dependence: X is written after store in MEM takes place. */ | |
2306 | ||
2307 | int | |
4682ae04 | 2308 | output_dependence (rtx mem, rtx x) |
9ae8ffe7 | 2309 | { |
389fdba0 | 2310 | return write_dependence_p (mem, x, /*writep=*/1); |
9ae8ffe7 | 2311 | } |
c14b9960 JW |
2312 | \f |
2313 | /* A subroutine of nonlocal_mentioned_p, returns 1 if *LOC mentions | |
2314 | something which is not local to the function and is not constant. */ | |
7790df19 JW |
2315 | |
2316 | static int | |
4682ae04 | 2317 | nonlocal_mentioned_p_1 (rtx *loc, void *data ATTRIBUTE_UNUSED) |
7790df19 | 2318 | { |
c14b9960 | 2319 | rtx x = *loc; |
7790df19 | 2320 | rtx base; |
7790df19 JW |
2321 | int regno; |
2322 | ||
c14b9960 JW |
2323 | if (! x) |
2324 | return 0; | |
7790df19 | 2325 | |
c14b9960 | 2326 | switch (GET_CODE (x)) |
7790df19 JW |
2327 | { |
2328 | case SUBREG: | |
f8cfc6aa | 2329 | if (REG_P (SUBREG_REG (x))) |
7790df19 JW |
2330 | { |
2331 | /* Global registers are not local. */ | |
2332 | if (REGNO (SUBREG_REG (x)) < FIRST_PSEUDO_REGISTER | |
ddef6bc7 | 2333 | && global_regs[subreg_regno (x)]) |
7790df19 JW |
2334 | return 1; |
2335 | return 0; | |
2336 | } | |
2337 | break; | |
2338 | ||
2339 | case REG: | |
2340 | regno = REGNO (x); | |
2341 | /* Global registers are not local. */ | |
2342 | if (regno < FIRST_PSEUDO_REGISTER && global_regs[regno]) | |
2343 | return 1; | |
2344 | return 0; | |
2345 | ||
2346 | case SCRATCH: | |
2347 | case PC: | |
2348 | case CC0: | |
2349 | case CONST_INT: | |
2350 | case CONST_DOUBLE: | |
69ef87e2 | 2351 | case CONST_VECTOR: |
7790df19 JW |
2352 | case CONST: |
2353 | case LABEL_REF: | |
2354 | return 0; | |
2355 | ||
2356 | case SYMBOL_REF: | |
2357 | /* Constants in the function's constants pool are constant. */ | |
2358 | if (CONSTANT_POOL_ADDRESS_P (x)) | |
2359 | return 0; | |
2360 | return 1; | |
2361 | ||
2362 | case CALL: | |
bf6d9fd7 | 2363 | /* Non-constant calls and recursion are not local. */ |
7790df19 JW |
2364 | return 1; |
2365 | ||
2366 | case MEM: | |
2367 | /* Be overly conservative and consider any volatile memory | |
2368 | reference as not local. */ | |
2369 | if (MEM_VOLATILE_P (x)) | |
2370 | return 1; | |
2371 | base = find_base_term (XEXP (x, 0)); | |
2372 | if (base) | |
2373 | { | |
b3b5ad95 JL |
2374 | /* A Pmode ADDRESS could be a reference via the structure value |
2375 | address or static chain. Such memory references are nonlocal. | |
2376 | ||
2377 | Thus, we have to examine the contents of the ADDRESS to find | |
2378 | out if this is a local reference or not. */ | |
2379 | if (GET_CODE (base) == ADDRESS | |
2380 | && GET_MODE (base) == Pmode | |
2381 | && (XEXP (base, 0) == stack_pointer_rtx | |
2382 | || XEXP (base, 0) == arg_pointer_rtx | |
2383 | #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM | |
2384 | || XEXP (base, 0) == hard_frame_pointer_rtx | |
2385 | #endif | |
2386 | || XEXP (base, 0) == frame_pointer_rtx)) | |
7790df19 JW |
2387 | return 0; |
2388 | /* Constants in the function's constant pool are constant. */ | |
2389 | if (GET_CODE (base) == SYMBOL_REF && CONSTANT_POOL_ADDRESS_P (base)) | |
2390 | return 0; | |
2391 | } | |
2392 | return 1; | |
2393 | ||
bf6d9fd7 | 2394 | case UNSPEC_VOLATILE: |
7790df19 | 2395 | case ASM_INPUT: |
7790df19 JW |
2396 | return 1; |
2397 | ||
bf6d9fd7 JW |
2398 | case ASM_OPERANDS: |
2399 | if (MEM_VOLATILE_P (x)) | |
2400 | return 1; | |
2401 | ||
5d3cc252 | 2402 | /* Fall through. */ |
bf6d9fd7 | 2403 | |
7790df19 JW |
2404 | default: |
2405 | break; | |
2406 | } | |
2407 | ||
c14b9960 JW |
2408 | return 0; |
2409 | } | |
2410 | ||
da7d8304 | 2411 | /* Returns nonzero if X might mention something which is not |
c14b9960 | 2412 | local to the function and is not constant. */ |
7790df19 | 2413 | |
c14b9960 | 2414 | static int |
4682ae04 | 2415 | nonlocal_mentioned_p (rtx x) |
c14b9960 | 2416 | { |
c14b9960 JW |
2417 | if (INSN_P (x)) |
2418 | { | |
4b4bf941 | 2419 | if (CALL_P (x)) |
c14b9960 JW |
2420 | { |
2421 | if (! CONST_OR_PURE_CALL_P (x)) | |
2422 | return 1; | |
2423 | x = CALL_INSN_FUNCTION_USAGE (x); | |
2424 | if (x == 0) | |
2425 | return 0; | |
ca7fd9cd | 2426 | } |
c14b9960 | 2427 | else |
ca7fd9cd | 2428 | x = PATTERN (x); |
c14b9960 JW |
2429 | } |
2430 | ||
2431 | return for_each_rtx (&x, nonlocal_mentioned_p_1, NULL); | |
2432 | } | |
2433 | ||
2434 | /* A subroutine of nonlocal_referenced_p, returns 1 if *LOC references | |
2435 | something which is not local to the function and is not constant. */ | |
2436 | ||
2437 | static int | |
4682ae04 | 2438 | nonlocal_referenced_p_1 (rtx *loc, void *data ATTRIBUTE_UNUSED) |
c14b9960 JW |
2439 | { |
2440 | rtx x = *loc; | |
2441 | ||
2442 | if (! x) | |
2443 | return 0; | |
2444 | ||
2445 | switch (GET_CODE (x)) | |
2446 | { | |
2447 | case MEM: | |
2448 | case REG: | |
2449 | case SYMBOL_REF: | |
2450 | case SUBREG: | |
2451 | return nonlocal_mentioned_p (x); | |
2452 | ||
2453 | case CALL: | |
2454 | /* Non-constant calls and recursion are not local. */ | |
2455 | return 1; | |
2456 | ||
2457 | case SET: | |
2458 | if (nonlocal_mentioned_p (SET_SRC (x))) | |
2459 | return 1; | |
2460 | ||
3c0cb5de | 2461 | if (MEM_P (SET_DEST (x))) |
c14b9960 JW |
2462 | return nonlocal_mentioned_p (XEXP (SET_DEST (x), 0)); |
2463 | ||
2464 | /* If the destination is anything other than a CC0, PC, | |
2465 | MEM, REG, or a SUBREG of a REG that occupies all of | |
2466 | the REG, then X references nonlocal memory if it is | |
2467 | mentioned in the destination. */ | |
2468 | if (GET_CODE (SET_DEST (x)) != CC0 | |
2469 | && GET_CODE (SET_DEST (x)) != PC | |
f8cfc6aa | 2470 | && !REG_P (SET_DEST (x)) |
c14b9960 | 2471 | && ! (GET_CODE (SET_DEST (x)) == SUBREG |
f8cfc6aa | 2472 | && REG_P (SUBREG_REG (SET_DEST (x))) |
c14b9960 JW |
2473 | && (((GET_MODE_SIZE (GET_MODE (SUBREG_REG (SET_DEST (x)))) |
2474 | + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD) | |
2475 | == ((GET_MODE_SIZE (GET_MODE (SET_DEST (x))) | |
2476 | + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD)))) | |
2477 | return nonlocal_mentioned_p (SET_DEST (x)); | |
2478 | return 0; | |
2479 | ||
2480 | case CLOBBER: | |
3c0cb5de | 2481 | if (MEM_P (XEXP (x, 0))) |
c14b9960 JW |
2482 | return nonlocal_mentioned_p (XEXP (XEXP (x, 0), 0)); |
2483 | return 0; | |
2484 | ||
2485 | case USE: | |
2486 | return nonlocal_mentioned_p (XEXP (x, 0)); | |
2487 | ||
2488 | case ASM_INPUT: | |
2489 | case UNSPEC_VOLATILE: | |
2490 | return 1; | |
2491 | ||
2492 | case ASM_OPERANDS: | |
2493 | if (MEM_VOLATILE_P (x)) | |
2494 | return 1; | |
2495 | ||
5d3cc252 | 2496 | /* Fall through. */ |
c14b9960 JW |
2497 | |
2498 | default: | |
2499 | break; | |
2500 | } | |
2501 | ||
2502 | return 0; | |
2503 | } | |
2504 | ||
da7d8304 | 2505 | /* Returns nonzero if X might reference something which is not |
c14b9960 JW |
2506 | local to the function and is not constant. */ |
2507 | ||
2508 | static int | |
4682ae04 | 2509 | nonlocal_referenced_p (rtx x) |
c14b9960 | 2510 | { |
c14b9960 JW |
2511 | if (INSN_P (x)) |
2512 | { | |
4b4bf941 | 2513 | if (CALL_P (x)) |
c14b9960 JW |
2514 | { |
2515 | if (! CONST_OR_PURE_CALL_P (x)) | |
2516 | return 1; | |
2517 | x = CALL_INSN_FUNCTION_USAGE (x); | |
2518 | if (x == 0) | |
2519 | return 0; | |
ca7fd9cd | 2520 | } |
c14b9960 | 2521 | else |
ca7fd9cd | 2522 | x = PATTERN (x); |
c14b9960 JW |
2523 | } |
2524 | ||
2525 | return for_each_rtx (&x, nonlocal_referenced_p_1, NULL); | |
2526 | } | |
2527 | ||
2528 | /* A subroutine of nonlocal_set_p, returns 1 if *LOC sets | |
2529 | something which is not local to the function and is not constant. */ | |
2530 | ||
2531 | static int | |
4682ae04 | 2532 | nonlocal_set_p_1 (rtx *loc, void *data ATTRIBUTE_UNUSED) |
c14b9960 JW |
2533 | { |
2534 | rtx x = *loc; | |
2535 | ||
2536 | if (! x) | |
2537 | return 0; | |
2538 | ||
2539 | switch (GET_CODE (x)) | |
2540 | { | |
2541 | case CALL: | |
2542 | /* Non-constant calls and recursion are not local. */ | |
2543 | return 1; | |
2544 | ||
2545 | case PRE_INC: | |
2546 | case PRE_DEC: | |
2547 | case POST_INC: | |
2548 | case POST_DEC: | |
2549 | case PRE_MODIFY: | |
2550 | case POST_MODIFY: | |
2551 | return nonlocal_mentioned_p (XEXP (x, 0)); | |
2552 | ||
2553 | case SET: | |
2554 | if (nonlocal_mentioned_p (SET_DEST (x))) | |
2555 | return 1; | |
2556 | return nonlocal_set_p (SET_SRC (x)); | |
2557 | ||
2558 | case CLOBBER: | |
2559 | return nonlocal_mentioned_p (XEXP (x, 0)); | |
2560 | ||
2561 | case USE: | |
2562 | return 0; | |
2563 | ||
2564 | case ASM_INPUT: | |
2565 | case UNSPEC_VOLATILE: | |
2566 | return 1; | |
2567 | ||
2568 | case ASM_OPERANDS: | |
2569 | if (MEM_VOLATILE_P (x)) | |
2570 | return 1; | |
2571 | ||
5d3cc252 | 2572 | /* Fall through. */ |
c14b9960 JW |
2573 | |
2574 | default: | |
2575 | break; | |
2576 | } | |
7790df19 JW |
2577 | |
2578 | return 0; | |
2579 | } | |
2580 | ||
da7d8304 | 2581 | /* Returns nonzero if X might set something which is not |
c14b9960 JW |
2582 | local to the function and is not constant. */ |
2583 | ||
2584 | static int | |
4682ae04 | 2585 | nonlocal_set_p (rtx x) |
c14b9960 | 2586 | { |
c14b9960 JW |
2587 | if (INSN_P (x)) |
2588 | { | |
4b4bf941 | 2589 | if (CALL_P (x)) |
c14b9960 JW |
2590 | { |
2591 | if (! CONST_OR_PURE_CALL_P (x)) | |
2592 | return 1; | |
2593 | x = CALL_INSN_FUNCTION_USAGE (x); | |
2594 | if (x == 0) | |
2595 | return 0; | |
ca7fd9cd | 2596 | } |
c14b9960 | 2597 | else |
ca7fd9cd | 2598 | x = PATTERN (x); |
c14b9960 JW |
2599 | } |
2600 | ||
2601 | return for_each_rtx (&x, nonlocal_set_p_1, NULL); | |
2602 | } | |
2603 | ||
c57ddcf1 | 2604 | /* Mark the function if it is pure or constant. */ |
7790df19 JW |
2605 | |
2606 | void | |
4682ae04 | 2607 | mark_constant_function (void) |
7790df19 JW |
2608 | { |
2609 | rtx insn; | |
c14b9960 | 2610 | int nonlocal_memory_referenced; |
7790df19 | 2611 | |
ab780373 | 2612 | if (TREE_READONLY (current_function_decl) |
bf6d9fd7 | 2613 | || DECL_IS_PURE (current_function_decl) |
7790df19 | 2614 | || TREE_THIS_VOLATILE (current_function_decl) |
ab780373 | 2615 | || current_function_has_nonlocal_goto |
5fd9b178 | 2616 | || !targetm.binds_local_p (current_function_decl)) |
7790df19 JW |
2617 | return; |
2618 | ||
e004f2f7 | 2619 | /* A loop might not return which counts as a side effect. */ |
0ecf09f9 | 2620 | if (mark_dfs_back_edges ()) |
e004f2f7 JW |
2621 | return; |
2622 | ||
c14b9960 | 2623 | nonlocal_memory_referenced = 0; |
bf6d9fd7 JW |
2624 | |
2625 | init_alias_analysis (); | |
2626 | ||
c14b9960 | 2627 | /* Determine if this is a constant or pure function. */ |
7790df19 JW |
2628 | |
2629 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) | |
c14b9960 JW |
2630 | { |
2631 | if (! INSN_P (insn)) | |
2632 | continue; | |
bf6d9fd7 | 2633 | |
c14b9960 JW |
2634 | if (nonlocal_set_p (insn) || global_reg_mentioned_p (insn) |
2635 | || volatile_refs_p (PATTERN (insn))) | |
ca7fd9cd | 2636 | break; |
7790df19 | 2637 | |
c14b9960 JW |
2638 | if (! nonlocal_memory_referenced) |
2639 | nonlocal_memory_referenced = nonlocal_referenced_p (insn); | |
2640 | } | |
ca7fd9cd | 2641 | |
c14b9960 | 2642 | end_alias_analysis (); |
ca7fd9cd | 2643 | |
7790df19 | 2644 | /* Mark the function. */ |
ca7fd9cd | 2645 | |
c14b9960 JW |
2646 | if (insn) |
2647 | ; | |
2648 | else if (nonlocal_memory_referenced) | |
c57ddcf1 RS |
2649 | { |
2650 | cgraph_rtl_info (current_function_decl)->pure_function = 1; | |
2651 | DECL_IS_PURE (current_function_decl) = 1; | |
2652 | } | |
c14b9960 | 2653 | else |
c57ddcf1 RS |
2654 | { |
2655 | cgraph_rtl_info (current_function_decl)->const_function = 1; | |
2656 | TREE_READONLY (current_function_decl) = 1; | |
2657 | } | |
7790df19 | 2658 | } |
c14b9960 | 2659 | \f |
6e73e666 | 2660 | |
6e73e666 | 2661 | void |
4682ae04 | 2662 | init_alias_once (void) |
6e73e666 | 2663 | { |
b3694847 | 2664 | int i; |
6e73e666 | 2665 | |
6e73e666 JC |
2666 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) |
2667 | /* Check whether this register can hold an incoming pointer | |
2668 | argument. FUNCTION_ARG_REGNO_P tests outgoing register | |
ec5c56db | 2669 | numbers, so translate if necessary due to register windows. */ |
6e73e666 JC |
2670 | if (FUNCTION_ARG_REGNO_P (OUTGOING_REGNO (i)) |
2671 | && HARD_REGNO_MODE_OK (i, Pmode)) | |
bf1660a6 JL |
2672 | static_reg_base_value[i] |
2673 | = gen_rtx_ADDRESS (VOIDmode, gen_rtx_REG (Pmode, i)); | |
2674 | ||
bf1660a6 JL |
2675 | static_reg_base_value[STACK_POINTER_REGNUM] |
2676 | = gen_rtx_ADDRESS (Pmode, stack_pointer_rtx); | |
2677 | static_reg_base_value[ARG_POINTER_REGNUM] | |
2678 | = gen_rtx_ADDRESS (Pmode, arg_pointer_rtx); | |
2679 | static_reg_base_value[FRAME_POINTER_REGNUM] | |
2680 | = gen_rtx_ADDRESS (Pmode, frame_pointer_rtx); | |
2681 | #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM | |
2682 | static_reg_base_value[HARD_FRAME_POINTER_REGNUM] | |
2683 | = gen_rtx_ADDRESS (Pmode, hard_frame_pointer_rtx); | |
2684 | #endif | |
2685 | } | |
2686 | ||
7b52eede JH |
2687 | /* Set MEMORY_MODIFIED when X modifies DATA (that is assumed |
2688 | to be memory reference. */ | |
2689 | static bool memory_modified; | |
2690 | static void | |
4682ae04 | 2691 | memory_modified_1 (rtx x, rtx pat ATTRIBUTE_UNUSED, void *data) |
7b52eede | 2692 | { |
3c0cb5de | 2693 | if (MEM_P (x)) |
7b52eede JH |
2694 | { |
2695 | if (anti_dependence (x, (rtx)data) || output_dependence (x, (rtx)data)) | |
2696 | memory_modified = true; | |
2697 | } | |
2698 | } | |
2699 | ||
2700 | ||
2701 | /* Return true when INSN possibly modify memory contents of MEM | |
454ff5cb | 2702 | (i.e. address can be modified). */ |
7b52eede | 2703 | bool |
4682ae04 | 2704 | memory_modified_in_insn_p (rtx mem, rtx insn) |
7b52eede JH |
2705 | { |
2706 | if (!INSN_P (insn)) | |
2707 | return false; | |
2708 | memory_modified = false; | |
2709 | note_stores (PATTERN (insn), memory_modified_1, mem); | |
2710 | return memory_modified; | |
2711 | } | |
2712 | ||
c13e8210 MM |
2713 | /* Initialize the aliasing machinery. Initialize the REG_KNOWN_VALUE |
2714 | array. */ | |
2715 | ||
9ae8ffe7 | 2716 | void |
4682ae04 | 2717 | init_alias_analysis (void) |
9ae8ffe7 | 2718 | { |
c582d54a | 2719 | unsigned int maxreg = max_reg_num (); |
ea64ef27 | 2720 | int changed, pass; |
b3694847 SS |
2721 | int i; |
2722 | unsigned int ui; | |
2723 | rtx insn; | |
9ae8ffe7 | 2724 | |
0d446150 JH |
2725 | timevar_push (TV_ALIAS_ANALYSIS); |
2726 | ||
bb1acb3e RH |
2727 | reg_known_value_size = maxreg - FIRST_PSEUDO_REGISTER; |
2728 | reg_known_value = ggc_calloc (reg_known_value_size, sizeof (rtx)); | |
2729 | reg_known_equiv_p = xcalloc (reg_known_value_size, sizeof (bool)); | |
9ae8ffe7 | 2730 | |
6e73e666 JC |
2731 | /* Overallocate reg_base_value to allow some growth during loop |
2732 | optimization. Loop unrolling can create a large number of | |
2733 | registers. */ | |
c582d54a JH |
2734 | if (old_reg_base_value) |
2735 | { | |
2736 | reg_base_value = old_reg_base_value; | |
2737 | /* If varray gets large zeroing cost may get important. */ | |
2738 | if (VARRAY_SIZE (reg_base_value) > 256 | |
2739 | && VARRAY_SIZE (reg_base_value) > 4 * maxreg) | |
2740 | VARRAY_GROW (reg_base_value, maxreg); | |
2741 | VARRAY_CLEAR (reg_base_value); | |
2742 | if (VARRAY_SIZE (reg_base_value) < maxreg) | |
2743 | VARRAY_GROW (reg_base_value, maxreg); | |
2744 | } | |
2745 | else | |
2746 | { | |
2747 | VARRAY_RTX_INIT (reg_base_value, maxreg, "reg_base_value"); | |
2748 | } | |
ac606739 | 2749 | |
c582d54a JH |
2750 | new_reg_base_value = xmalloc (maxreg * sizeof (rtx)); |
2751 | reg_seen = xmalloc (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 | |
2762 | of REG_N_SETS 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 JL |
2820 | /* If this insn has a noalias note, process it, Otherwise, |
2821 | scan for sets. A simple set will have no side effects | |
ec5c56db | 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 BS |
2840 | |
2841 | if (REG_NOTES (insn) != 0 | |
2842 | && (((note = find_reg_note (insn, REG_EQUAL, 0)) != 0 | |
2843 | && REG_N_SETS (regno) == 1) | |
2844 | || (note = find_reg_note (insn, REG_EQUIV, NULL_RTX)) != 0) | |
2845 | && GET_CODE (XEXP (note, 0)) != EXPR_LIST | |
bb2cf916 | 2846 | && ! rtx_varies_p (XEXP (note, 0), 1) |
bb1acb3e RH |
2847 | && ! reg_overlap_mentioned_p (SET_DEST (set), |
2848 | XEXP (note, 0))) | |
713f41f9 | 2849 | { |
bb1acb3e RH |
2850 | set_reg_known_value (regno, XEXP (note, 0)); |
2851 | set_reg_known_equiv_p (regno, | |
2852 | REG_NOTE_KIND (note) == REG_EQUIV); | |
713f41f9 BS |
2853 | } |
2854 | else if (REG_N_SETS (regno) == 1 | |
2855 | && GET_CODE (src) == PLUS | |
f8cfc6aa | 2856 | && REG_P (XEXP (src, 0)) |
bb1acb3e | 2857 | && (t = get_reg_known_value (REGNO (XEXP (src, 0)))) |
713f41f9 BS |
2858 | && GET_CODE (XEXP (src, 1)) == CONST_INT) |
2859 | { | |
bb1acb3e RH |
2860 | t = plus_constant (t, INTVAL (XEXP (src, 1))); |
2861 | set_reg_known_value (regno, t); | |
2862 | set_reg_known_equiv_p (regno, 0); | |
713f41f9 BS |
2863 | } |
2864 | else if (REG_N_SETS (regno) == 1 | |
2865 | && ! rtx_varies_p (src, 1)) | |
2866 | { | |
bb1acb3e RH |
2867 | set_reg_known_value (regno, src); |
2868 | set_reg_known_equiv_p (regno, 0); | |
713f41f9 | 2869 | } |
6e73e666 | 2870 | } |
ec907dd8 | 2871 | } |
4b4bf941 | 2872 | else if (NOTE_P (insn) |
ec907dd8 | 2873 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_BEG) |
83bbd9b6 | 2874 | copying_arguments = false; |
6e73e666 | 2875 | } |
ec907dd8 | 2876 | |
6e73e666 | 2877 | /* Now propagate values from new_reg_base_value to reg_base_value. */ |
298e6adc NS |
2878 | gcc_assert (maxreg == (unsigned int) max_reg_num()); |
2879 | ||
c582d54a | 2880 | for (ui = 0; ui < maxreg; ui++) |
6e73e666 | 2881 | { |
e51712db | 2882 | if (new_reg_base_value[ui] |
c582d54a JH |
2883 | && new_reg_base_value[ui] != VARRAY_RTX (reg_base_value, ui) |
2884 | && ! rtx_equal_p (new_reg_base_value[ui], | |
2885 | VARRAY_RTX (reg_base_value, ui))) | |
ec907dd8 | 2886 | { |
c582d54a | 2887 | VARRAY_RTX (reg_base_value, ui) = new_reg_base_value[ui]; |
6e73e666 | 2888 | changed = 1; |
ec907dd8 | 2889 | } |
9ae8ffe7 | 2890 | } |
9ae8ffe7 | 2891 | } |
6e73e666 | 2892 | while (changed && ++pass < MAX_ALIAS_LOOP_PASSES); |
9ae8ffe7 JL |
2893 | |
2894 | /* Fill in the remaining entries. */ | |
bb1acb3e | 2895 | for (i = 0; i < (int)reg_known_value_size; i++) |
9ae8ffe7 | 2896 | if (reg_known_value[i] == 0) |
bb1acb3e | 2897 | reg_known_value[i] = regno_reg_rtx[i + FIRST_PSEUDO_REGISTER]; |
9ae8ffe7 | 2898 | |
9ae8ffe7 JL |
2899 | /* Simplify the reg_base_value array so that no register refers to |
2900 | another register, except to special registers indirectly through | |
2901 | ADDRESS expressions. | |
2902 | ||
2903 | In theory this loop can take as long as O(registers^2), but unless | |
2904 | there are very long dependency chains it will run in close to linear | |
ea64ef27 JL |
2905 | time. |
2906 | ||
2907 | This loop may not be needed any longer now that the main loop does | |
2908 | a better job at propagating alias information. */ | |
2909 | pass = 0; | |
9ae8ffe7 JL |
2910 | do |
2911 | { | |
2912 | changed = 0; | |
ea64ef27 | 2913 | pass++; |
c582d54a | 2914 | for (ui = 0; ui < maxreg; ui++) |
9ae8ffe7 | 2915 | { |
c582d54a | 2916 | rtx base = VARRAY_RTX (reg_base_value, ui); |
f8cfc6aa | 2917 | if (base && REG_P (base)) |
9ae8ffe7 | 2918 | { |
fb6754f0 | 2919 | unsigned int base_regno = REGNO (base); |
e51712db | 2920 | if (base_regno == ui) /* register set from itself */ |
c582d54a | 2921 | VARRAY_RTX (reg_base_value, ui) = 0; |
9ae8ffe7 | 2922 | else |
c582d54a JH |
2923 | VARRAY_RTX (reg_base_value, ui) |
2924 | = VARRAY_RTX (reg_base_value, base_regno); | |
9ae8ffe7 JL |
2925 | changed = 1; |
2926 | } | |
2927 | } | |
2928 | } | |
ea64ef27 | 2929 | while (changed && pass < MAX_ALIAS_LOOP_PASSES); |
9ae8ffe7 | 2930 | |
e05e2395 MM |
2931 | /* Clean up. */ |
2932 | free (new_reg_base_value); | |
ec907dd8 | 2933 | new_reg_base_value = 0; |
e05e2395 | 2934 | free (reg_seen); |
9ae8ffe7 | 2935 | reg_seen = 0; |
0d446150 | 2936 | timevar_pop (TV_ALIAS_ANALYSIS); |
9ae8ffe7 JL |
2937 | } |
2938 | ||
2939 | void | |
4682ae04 | 2940 | end_alias_analysis (void) |
9ae8ffe7 | 2941 | { |
c582d54a | 2942 | old_reg_base_value = reg_base_value; |
bb1acb3e | 2943 | ggc_free (reg_known_value); |
9ae8ffe7 | 2944 | reg_known_value = 0; |
ac606739 | 2945 | reg_known_value_size = 0; |
bb1acb3e | 2946 | free (reg_known_equiv_p); |
e05e2395 | 2947 | reg_known_equiv_p = 0; |
de12be17 JC |
2948 | if (alias_invariant) |
2949 | { | |
f411a73a | 2950 | ggc_free (alias_invariant); |
de12be17 | 2951 | alias_invariant = 0; |
c582d54a | 2952 | alias_invariant_size = 0; |
de12be17 | 2953 | } |
9ae8ffe7 | 2954 | } |
e2500fed GK |
2955 | |
2956 | #include "gt-alias.h" |