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cbdd87d4 RG |
1 | /* Statement simplification on GIMPLE. |
2 | Copyright (C) 2010 Free Software Foundation, Inc. | |
3 | Split out from tree-ssa-ccp.c. | |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it | |
8 | under the terms of the GNU General Public License as published by the | |
9 | Free Software Foundation; either version 3, or (at your option) any | |
10 | later version. | |
11 | ||
12 | GCC is distributed in the hope that it will be useful, but WITHOUT | |
13 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GCC; see the file COPYING3. If not see | |
19 | <http://www.gnu.org/licenses/>. */ | |
20 | ||
21 | #include "config.h" | |
22 | #include "system.h" | |
23 | #include "coretypes.h" | |
24 | #include "tm.h" | |
25 | #include "tree.h" | |
26 | #include "flags.h" | |
cbdd87d4 | 27 | #include "function.h" |
cbdd87d4 RG |
28 | #include "tree-dump.h" |
29 | #include "tree-flow.h" | |
30 | #include "tree-pass.h" | |
31 | #include "tree-ssa-propagate.h" | |
cbdd87d4 | 32 | #include "target.h" |
cfef45c8 | 33 | #include "gimple-fold.h" |
cbdd87d4 | 34 | |
b3b9f3d0 JH |
35 | /* Return true when DECL can be referenced from current unit. |
36 | We can get declarations that are not possible to reference for | |
37 | various reasons: | |
1389294c | 38 | |
1389294c JH |
39 | 1) When analyzing C++ virtual tables. |
40 | C++ virtual tables do have known constructors even | |
41 | when they are keyed to other compilation unit. | |
42 | Those tables can contain pointers to methods and vars | |
43 | in other units. Those methods have both STATIC and EXTERNAL | |
44 | set. | |
45 | 2) In WHOPR mode devirtualization might lead to reference | |
46 | to method that was partitioned elsehwere. | |
47 | In this case we have static VAR_DECL or FUNCTION_DECL | |
48 | that has no corresponding callgraph/varpool node | |
b3b9f3d0 JH |
49 | declaring the body. |
50 | 3) COMDAT functions referred by external vtables that | |
51 | we devirtualize only during final copmilation stage. | |
52 | At this time we already decided that we will not output | |
53 | the function body and thus we can't reference the symbol | |
54 | directly. */ | |
55 | ||
1389294c | 56 | static bool |
b3b9f3d0 | 57 | can_refer_decl_in_current_unit_p (tree decl) |
1389294c JH |
58 | { |
59 | struct varpool_node *vnode; | |
60 | struct cgraph_node *node; | |
61 | ||
b3b9f3d0 JH |
62 | if (!TREE_STATIC (decl) && !DECL_EXTERNAL (decl)) |
63 | return true; | |
1389294c JH |
64 | /* External flag is set, so we deal with C++ reference |
65 | to static object from other file. */ | |
b3b9f3d0 JH |
66 | if (DECL_EXTERNAL (decl) && TREE_STATIC (decl) |
67 | && TREE_CODE (decl) == VAR_DECL) | |
1389294c JH |
68 | { |
69 | /* Just be sure it is not big in frontend setting | |
70 | flags incorrectly. Those variables should never | |
71 | be finalized. */ | |
72 | gcc_checking_assert (!(vnode = varpool_get_node (decl)) | |
73 | || !vnode->finalized); | |
b3b9f3d0 | 74 | return false; |
1389294c | 75 | } |
b3b9f3d0 JH |
76 | /* When function is public, we always can introduce new reference. |
77 | Exception are the COMDAT functions where introducing a direct | |
78 | reference imply need to include function body in the curren tunit. */ | |
79 | if (TREE_PUBLIC (decl) && !DECL_COMDAT (decl)) | |
80 | return true; | |
81 | /* We are not at ltrans stage; so don't worry about WHOPR. | |
82 | Also when still gimplifying all referred comdat functions will be | |
2e9bb6ba JH |
83 | produced. |
84 | ??? as observed in PR20991 for already optimized out comdat virtual functions | |
85 | we may not neccesarily give up because the copy will be output elsewhere when | |
86 | corresponding vtable is output. */ | |
b3b9f3d0 JH |
87 | if (!flag_ltrans && (!DECL_COMDAT (decl) || !cgraph_function_flags_ready)) |
88 | return true; | |
89 | /* If we already output the function body, we are safe. */ | |
90 | if (TREE_ASM_WRITTEN (decl)) | |
91 | return true; | |
1389294c JH |
92 | if (TREE_CODE (decl) == FUNCTION_DECL) |
93 | { | |
94 | node = cgraph_get_node (decl); | |
b3b9f3d0 JH |
95 | /* Check that we still have function body and that we didn't took |
96 | the decision to eliminate offline copy of the function yet. | |
97 | The second is important when devirtualization happens during final | |
98 | compilation stage when making a new reference no longer makes callee | |
99 | to be compiled. */ | |
100 | if (!node || !node->analyzed || node->global.inlined_to) | |
101 | return false; | |
1389294c JH |
102 | } |
103 | else if (TREE_CODE (decl) == VAR_DECL) | |
104 | { | |
105 | vnode = varpool_get_node (decl); | |
106 | if (!vnode || !vnode->finalized) | |
b3b9f3d0 | 107 | return false; |
1389294c | 108 | } |
b3b9f3d0 | 109 | return true; |
1389294c JH |
110 | } |
111 | ||
0038d4e0 | 112 | /* CVAL is value taken from DECL_INITIAL of variable. Try to transform it into |
17f39a39 JH |
113 | acceptable form for is_gimple_min_invariant. */ |
114 | ||
115 | tree | |
116 | canonicalize_constructor_val (tree cval) | |
117 | { | |
118 | STRIP_NOPS (cval); | |
119 | if (TREE_CODE (cval) == POINTER_PLUS_EXPR) | |
120 | { | |
121 | tree t = maybe_fold_offset_to_address (EXPR_LOCATION (cval), | |
122 | TREE_OPERAND (cval, 0), | |
123 | TREE_OPERAND (cval, 1), | |
124 | TREE_TYPE (cval)); | |
125 | if (t) | |
126 | cval = t; | |
127 | } | |
128 | if (TREE_CODE (cval) == ADDR_EXPR) | |
129 | { | |
130 | tree base = get_base_address (TREE_OPERAND (cval, 0)); | |
b3b9f3d0 | 131 | |
1389294c JH |
132 | if (base |
133 | && (TREE_CODE (base) == VAR_DECL | |
134 | || TREE_CODE (base) == FUNCTION_DECL) | |
b3b9f3d0 | 135 | && !can_refer_decl_in_current_unit_p (base)) |
1389294c | 136 | return NULL_TREE; |
0038d4e0 | 137 | if (cfun && base && TREE_CODE (base) == VAR_DECL) |
17f39a39 | 138 | add_referenced_var (base); |
0038d4e0 | 139 | /* Fixup types in global initializers. */ |
73aef89e RG |
140 | if (TREE_TYPE (TREE_TYPE (cval)) != TREE_TYPE (TREE_OPERAND (cval, 0))) |
141 | cval = build_fold_addr_expr (TREE_OPERAND (cval, 0)); | |
17f39a39 JH |
142 | } |
143 | return cval; | |
144 | } | |
cbdd87d4 RG |
145 | |
146 | /* If SYM is a constant variable with known value, return the value. | |
147 | NULL_TREE is returned otherwise. */ | |
148 | ||
149 | tree | |
150 | get_symbol_constant_value (tree sym) | |
151 | { | |
64e0f5ff | 152 | if (const_value_known_p (sym)) |
cbdd87d4 RG |
153 | { |
154 | tree val = DECL_INITIAL (sym); | |
155 | if (val) | |
156 | { | |
17f39a39 | 157 | val = canonicalize_constructor_val (val); |
1389294c | 158 | if (val && is_gimple_min_invariant (val)) |
17f39a39 | 159 | return val; |
1389294c JH |
160 | else |
161 | return NULL_TREE; | |
cbdd87d4 RG |
162 | } |
163 | /* Variables declared 'const' without an initializer | |
164 | have zero as the initializer if they may not be | |
165 | overridden at link or run time. */ | |
166 | if (!val | |
cbdd87d4 RG |
167 | && (INTEGRAL_TYPE_P (TREE_TYPE (sym)) |
168 | || SCALAR_FLOAT_TYPE_P (TREE_TYPE (sym)))) | |
e8160c9a | 169 | return build_zero_cst (TREE_TYPE (sym)); |
cbdd87d4 RG |
170 | } |
171 | ||
172 | return NULL_TREE; | |
173 | } | |
174 | ||
175 | ||
176 | /* Return true if we may propagate the address expression ADDR into the | |
177 | dereference DEREF and cancel them. */ | |
178 | ||
179 | bool | |
180 | may_propagate_address_into_dereference (tree addr, tree deref) | |
181 | { | |
70f34814 | 182 | gcc_assert (TREE_CODE (deref) == MEM_REF |
cbdd87d4 RG |
183 | && TREE_CODE (addr) == ADDR_EXPR); |
184 | ||
185 | /* Don't propagate if ADDR's operand has incomplete type. */ | |
186 | if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_OPERAND (addr, 0)))) | |
187 | return false; | |
188 | ||
189 | /* If the address is invariant then we do not need to preserve restrict | |
190 | qualifications. But we do need to preserve volatile qualifiers until | |
191 | we can annotate the folded dereference itself properly. */ | |
192 | if (is_gimple_min_invariant (addr) | |
193 | && (!TREE_THIS_VOLATILE (deref) | |
194 | || TYPE_VOLATILE (TREE_TYPE (addr)))) | |
195 | return useless_type_conversion_p (TREE_TYPE (deref), | |
196 | TREE_TYPE (TREE_OPERAND (addr, 0))); | |
197 | ||
198 | /* Else both the address substitution and the folding must result in | |
199 | a valid useless type conversion sequence. */ | |
200 | return (useless_type_conversion_p (TREE_TYPE (TREE_OPERAND (deref, 0)), | |
201 | TREE_TYPE (addr)) | |
202 | && useless_type_conversion_p (TREE_TYPE (deref), | |
203 | TREE_TYPE (TREE_OPERAND (addr, 0)))); | |
204 | } | |
205 | ||
206 | ||
207 | /* A subroutine of fold_stmt. Attempts to fold *(A+O) to A[X]. | |
70f34814 | 208 | BASE is an array type. OFFSET is a byte displacement. |
cbdd87d4 RG |
209 | |
210 | LOC is the location of the original expression. */ | |
211 | ||
212 | static tree | |
70f34814 | 213 | maybe_fold_offset_to_array_ref (location_t loc, tree base, tree offset) |
cbdd87d4 RG |
214 | { |
215 | tree min_idx, idx, idx_type, elt_offset = integer_zero_node; | |
216 | tree array_type, elt_type, elt_size; | |
217 | tree domain_type; | |
218 | ||
219 | /* If BASE is an ARRAY_REF, we can pick up another offset (this time | |
220 | measured in units of the size of elements type) from that ARRAY_REF). | |
221 | We can't do anything if either is variable. | |
222 | ||
223 | The case we handle here is *(&A[N]+O). */ | |
224 | if (TREE_CODE (base) == ARRAY_REF) | |
225 | { | |
226 | tree low_bound = array_ref_low_bound (base); | |
227 | ||
228 | elt_offset = TREE_OPERAND (base, 1); | |
229 | if (TREE_CODE (low_bound) != INTEGER_CST | |
230 | || TREE_CODE (elt_offset) != INTEGER_CST) | |
231 | return NULL_TREE; | |
232 | ||
233 | elt_offset = int_const_binop (MINUS_EXPR, elt_offset, low_bound, 0); | |
234 | base = TREE_OPERAND (base, 0); | |
235 | } | |
236 | ||
237 | /* Ignore stupid user tricks of indexing non-array variables. */ | |
238 | array_type = TREE_TYPE (base); | |
239 | if (TREE_CODE (array_type) != ARRAY_TYPE) | |
240 | return NULL_TREE; | |
241 | elt_type = TREE_TYPE (array_type); | |
cbdd87d4 RG |
242 | |
243 | /* Use signed size type for intermediate computation on the index. */ | |
3b9e5d95 | 244 | idx_type = ssizetype; |
cbdd87d4 RG |
245 | |
246 | /* If OFFSET and ELT_OFFSET are zero, we don't care about the size of the | |
247 | element type (so we can use the alignment if it's not constant). | |
248 | Otherwise, compute the offset as an index by using a division. If the | |
249 | division isn't exact, then don't do anything. */ | |
250 | elt_size = TYPE_SIZE_UNIT (elt_type); | |
251 | if (!elt_size) | |
252 | return NULL; | |
253 | if (integer_zerop (offset)) | |
254 | { | |
255 | if (TREE_CODE (elt_size) != INTEGER_CST) | |
256 | elt_size = size_int (TYPE_ALIGN (elt_type)); | |
257 | ||
258 | idx = build_int_cst (idx_type, 0); | |
259 | } | |
260 | else | |
261 | { | |
262 | unsigned HOST_WIDE_INT lquo, lrem; | |
263 | HOST_WIDE_INT hquo, hrem; | |
264 | double_int soffset; | |
265 | ||
266 | /* The final array offset should be signed, so we need | |
267 | to sign-extend the (possibly pointer) offset here | |
268 | and use signed division. */ | |
269 | soffset = double_int_sext (tree_to_double_int (offset), | |
270 | TYPE_PRECISION (TREE_TYPE (offset))); | |
271 | if (TREE_CODE (elt_size) != INTEGER_CST | |
272 | || div_and_round_double (TRUNC_DIV_EXPR, 0, | |
273 | soffset.low, soffset.high, | |
274 | TREE_INT_CST_LOW (elt_size), | |
275 | TREE_INT_CST_HIGH (elt_size), | |
276 | &lquo, &hquo, &lrem, &hrem) | |
277 | || lrem || hrem) | |
278 | return NULL_TREE; | |
279 | ||
280 | idx = build_int_cst_wide (idx_type, lquo, hquo); | |
281 | } | |
282 | ||
283 | /* Assume the low bound is zero. If there is a domain type, get the | |
284 | low bound, if any, convert the index into that type, and add the | |
285 | low bound. */ | |
286 | min_idx = build_int_cst (idx_type, 0); | |
287 | domain_type = TYPE_DOMAIN (array_type); | |
288 | if (domain_type) | |
289 | { | |
290 | idx_type = domain_type; | |
291 | if (TYPE_MIN_VALUE (idx_type)) | |
292 | min_idx = TYPE_MIN_VALUE (idx_type); | |
293 | else | |
294 | min_idx = fold_convert (idx_type, min_idx); | |
295 | ||
296 | if (TREE_CODE (min_idx) != INTEGER_CST) | |
297 | return NULL_TREE; | |
298 | ||
299 | elt_offset = fold_convert (idx_type, elt_offset); | |
300 | } | |
301 | ||
302 | if (!integer_zerop (min_idx)) | |
303 | idx = int_const_binop (PLUS_EXPR, idx, min_idx, 0); | |
304 | if (!integer_zerop (elt_offset)) | |
305 | idx = int_const_binop (PLUS_EXPR, idx, elt_offset, 0); | |
306 | ||
307 | /* Make sure to possibly truncate late after offsetting. */ | |
308 | idx = fold_convert (idx_type, idx); | |
309 | ||
310 | /* We don't want to construct access past array bounds. For example | |
311 | char *(c[4]); | |
312 | c[3][2]; | |
313 | should not be simplified into (*c)[14] or tree-vrp will | |
70f34814 RG |
314 | give false warnings. |
315 | This is only an issue for multi-dimensional arrays. */ | |
316 | if (TREE_CODE (elt_type) == ARRAY_TYPE | |
317 | && domain_type) | |
cbdd87d4 | 318 | { |
70f34814 RG |
319 | if (TYPE_MAX_VALUE (domain_type) |
320 | && TREE_CODE (TYPE_MAX_VALUE (domain_type)) == INTEGER_CST | |
321 | && tree_int_cst_lt (TYPE_MAX_VALUE (domain_type), idx)) | |
cbdd87d4 | 322 | return NULL_TREE; |
70f34814 RG |
323 | else if (TYPE_MIN_VALUE (domain_type) |
324 | && TREE_CODE (TYPE_MIN_VALUE (domain_type)) == INTEGER_CST | |
325 | && tree_int_cst_lt (idx, TYPE_MIN_VALUE (domain_type))) | |
326 | return NULL_TREE; | |
327 | else if (compare_tree_int (idx, 0) < 0) | |
cbdd87d4 RG |
328 | return NULL_TREE; |
329 | } | |
cbdd87d4 RG |
330 | |
331 | { | |
332 | tree t = build4 (ARRAY_REF, elt_type, base, idx, NULL_TREE, NULL_TREE); | |
333 | SET_EXPR_LOCATION (t, loc); | |
334 | return t; | |
335 | } | |
336 | } | |
337 | ||
338 | ||
70f34814 | 339 | /* Attempt to express (ORIG_TYPE)BASE+OFFSET as BASE[index]. |
cbdd87d4 RG |
340 | LOC is the location of original expression. |
341 | ||
70f34814 | 342 | Before attempting the conversion strip off existing ADDR_EXPRs. */ |
cbdd87d4 RG |
343 | |
344 | tree | |
345 | maybe_fold_offset_to_reference (location_t loc, tree base, tree offset, | |
346 | tree orig_type) | |
347 | { | |
348 | tree ret; | |
cbdd87d4 RG |
349 | |
350 | STRIP_NOPS (base); | |
351 | if (TREE_CODE (base) != ADDR_EXPR) | |
352 | return NULL_TREE; | |
353 | ||
354 | base = TREE_OPERAND (base, 0); | |
70f34814 | 355 | if (types_compatible_p (orig_type, TREE_TYPE (base)) |
cbdd87d4 RG |
356 | && integer_zerop (offset)) |
357 | return base; | |
cbdd87d4 | 358 | |
70f34814 RG |
359 | ret = maybe_fold_offset_to_array_ref (loc, base, offset); |
360 | if (ret && types_compatible_p (orig_type, TREE_TYPE (ret))) | |
361 | return ret; | |
362 | return NULL_TREE; | |
cbdd87d4 RG |
363 | } |
364 | ||
70f34814 RG |
365 | /* Attempt to express (ORIG_TYPE)ADDR+OFFSET as (*ADDR)[index]. |
366 | LOC is the location of the original expression. */ | |
cbdd87d4 RG |
367 | |
368 | tree | |
369 | maybe_fold_offset_to_address (location_t loc, tree addr, tree offset, | |
370 | tree orig_type) | |
371 | { | |
70f34814 | 372 | tree base, ret; |
cbdd87d4 | 373 | |
70f34814 RG |
374 | STRIP_NOPS (addr); |
375 | if (TREE_CODE (addr) != ADDR_EXPR) | |
376 | return NULL_TREE; | |
377 | base = TREE_OPERAND (addr, 0); | |
378 | ret = maybe_fold_offset_to_array_ref (loc, base, offset); | |
379 | if (ret) | |
cbdd87d4 | 380 | { |
70f34814 RG |
381 | ret = build_fold_addr_expr (ret); |
382 | if (!useless_type_conversion_p (orig_type, TREE_TYPE (ret))) | |
cbdd87d4 | 383 | return NULL_TREE; |
70f34814 | 384 | SET_EXPR_LOCATION (ret, loc); |
cbdd87d4 RG |
385 | } |
386 | ||
70f34814 | 387 | return ret; |
cbdd87d4 RG |
388 | } |
389 | ||
390 | ||
391 | /* A quaint feature extant in our address arithmetic is that there | |
392 | can be hidden type changes here. The type of the result need | |
393 | not be the same as the type of the input pointer. | |
394 | ||
395 | What we're after here is an expression of the form | |
396 | (T *)(&array + const) | |
397 | where array is OP0, const is OP1, RES_TYPE is T and | |
398 | the cast doesn't actually exist, but is implicit in the | |
399 | type of the POINTER_PLUS_EXPR. We'd like to turn this into | |
400 | &array[x] | |
401 | which may be able to propagate further. */ | |
402 | ||
403 | tree | |
404 | maybe_fold_stmt_addition (location_t loc, tree res_type, tree op0, tree op1) | |
405 | { | |
406 | tree ptd_type; | |
407 | tree t; | |
408 | ||
409 | /* The first operand should be an ADDR_EXPR. */ | |
410 | if (TREE_CODE (op0) != ADDR_EXPR) | |
411 | return NULL_TREE; | |
412 | op0 = TREE_OPERAND (op0, 0); | |
413 | ||
414 | /* It had better be a constant. */ | |
415 | if (TREE_CODE (op1) != INTEGER_CST) | |
416 | { | |
417 | /* Or op0 should now be A[0] and the non-constant offset defined | |
418 | via a multiplication by the array element size. */ | |
419 | if (TREE_CODE (op0) == ARRAY_REF | |
c946a318 RG |
420 | /* As we will end up creating a variable index array access |
421 | in the outermost array dimension make sure there isn't | |
422 | a more inner array that the index could overflow to. */ | |
70f34814 RG |
423 | && TREE_CODE (TREE_OPERAND (op0, 0)) != ARRAY_REF |
424 | && integer_zerop (TREE_OPERAND (op0, 1)) | |
425 | && TREE_CODE (op1) == SSA_NAME) | |
426 | { | |
427 | gimple offset_def = SSA_NAME_DEF_STMT (op1); | |
428 | tree elsz = TYPE_SIZE_UNIT (TREE_TYPE (op0)); | |
429 | if (!host_integerp (elsz, 1) | |
430 | || !is_gimple_assign (offset_def)) | |
c946a318 RG |
431 | return NULL_TREE; |
432 | ||
433 | /* Do not build array references of something that we can't | |
434 | see the true number of array dimensions for. */ | |
435 | if (!DECL_P (TREE_OPERAND (op0, 0)) | |
436 | && !handled_component_p (TREE_OPERAND (op0, 0))) | |
437 | return NULL_TREE; | |
438 | ||
cbdd87d4 RG |
439 | if (gimple_assign_rhs_code (offset_def) == MULT_EXPR |
440 | && TREE_CODE (gimple_assign_rhs2 (offset_def)) == INTEGER_CST | |
70f34814 | 441 | && tree_int_cst_equal (gimple_assign_rhs2 (offset_def), elsz)) |
cbdd87d4 RG |
442 | return build_fold_addr_expr |
443 | (build4 (ARRAY_REF, TREE_TYPE (op0), | |
444 | TREE_OPERAND (op0, 0), | |
445 | gimple_assign_rhs1 (offset_def), | |
446 | TREE_OPERAND (op0, 2), | |
447 | TREE_OPERAND (op0, 3))); | |
70f34814 | 448 | else if (integer_onep (elsz) |
cbdd87d4 RG |
449 | && gimple_assign_rhs_code (offset_def) != MULT_EXPR) |
450 | return build_fold_addr_expr | |
451 | (build4 (ARRAY_REF, TREE_TYPE (op0), | |
452 | TREE_OPERAND (op0, 0), | |
453 | op1, | |
454 | TREE_OPERAND (op0, 2), | |
455 | TREE_OPERAND (op0, 3))); | |
456 | } | |
70f34814 RG |
457 | else if (TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE |
458 | /* Dto. */ | |
459 | && TREE_CODE (TREE_TYPE (TREE_TYPE (op0))) != ARRAY_TYPE | |
460 | && TREE_CODE (op1) == SSA_NAME) | |
461 | { | |
462 | gimple offset_def = SSA_NAME_DEF_STMT (op1); | |
463 | tree elsz = TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (op0))); | |
464 | if (!host_integerp (elsz, 1) | |
465 | || !is_gimple_assign (offset_def)) | |
466 | return NULL_TREE; | |
467 | ||
468 | /* Do not build array references of something that we can't | |
469 | see the true number of array dimensions for. */ | |
470 | if (!DECL_P (op0) | |
471 | && !handled_component_p (op0)) | |
472 | return NULL_TREE; | |
473 | ||
474 | if (gimple_assign_rhs_code (offset_def) == MULT_EXPR | |
475 | && TREE_CODE (gimple_assign_rhs2 (offset_def)) == INTEGER_CST | |
476 | && tree_int_cst_equal (gimple_assign_rhs2 (offset_def), elsz)) | |
477 | return build_fold_addr_expr | |
478 | (build4 (ARRAY_REF, TREE_TYPE (TREE_TYPE (op0)), | |
479 | op0, gimple_assign_rhs1 (offset_def), | |
480 | integer_zero_node, NULL_TREE)); | |
481 | else if (integer_onep (elsz) | |
482 | && gimple_assign_rhs_code (offset_def) != MULT_EXPR) | |
483 | return build_fold_addr_expr | |
484 | (build4 (ARRAY_REF, TREE_TYPE (TREE_TYPE (op0)), | |
485 | op0, op1, | |
486 | integer_zero_node, NULL_TREE)); | |
487 | } | |
488 | ||
cbdd87d4 RG |
489 | return NULL_TREE; |
490 | } | |
491 | ||
492 | /* If the first operand is an ARRAY_REF, expand it so that we can fold | |
493 | the offset into it. */ | |
494 | while (TREE_CODE (op0) == ARRAY_REF) | |
495 | { | |
496 | tree array_obj = TREE_OPERAND (op0, 0); | |
497 | tree array_idx = TREE_OPERAND (op0, 1); | |
498 | tree elt_type = TREE_TYPE (op0); | |
499 | tree elt_size = TYPE_SIZE_UNIT (elt_type); | |
500 | tree min_idx; | |
501 | ||
502 | if (TREE_CODE (array_idx) != INTEGER_CST) | |
503 | break; | |
504 | if (TREE_CODE (elt_size) != INTEGER_CST) | |
505 | break; | |
506 | ||
507 | /* Un-bias the index by the min index of the array type. */ | |
508 | min_idx = TYPE_DOMAIN (TREE_TYPE (array_obj)); | |
509 | if (min_idx) | |
510 | { | |
511 | min_idx = TYPE_MIN_VALUE (min_idx); | |
512 | if (min_idx) | |
513 | { | |
514 | if (TREE_CODE (min_idx) != INTEGER_CST) | |
515 | break; | |
516 | ||
517 | array_idx = fold_convert (TREE_TYPE (min_idx), array_idx); | |
518 | if (!integer_zerop (min_idx)) | |
519 | array_idx = int_const_binop (MINUS_EXPR, array_idx, | |
520 | min_idx, 0); | |
521 | } | |
522 | } | |
523 | ||
524 | /* Convert the index to a byte offset. */ | |
525 | array_idx = fold_convert (sizetype, array_idx); | |
526 | array_idx = int_const_binop (MULT_EXPR, array_idx, elt_size, 0); | |
527 | ||
528 | /* Update the operands for the next round, or for folding. */ | |
529 | op1 = int_const_binop (PLUS_EXPR, | |
530 | array_idx, op1, 0); | |
531 | op0 = array_obj; | |
532 | } | |
533 | ||
534 | ptd_type = TREE_TYPE (res_type); | |
535 | /* If we want a pointer to void, reconstruct the reference from the | |
536 | array element type. A pointer to that can be trivially converted | |
537 | to void *. This happens as we fold (void *)(ptr p+ off). */ | |
538 | if (VOID_TYPE_P (ptd_type) | |
539 | && TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE) | |
540 | ptd_type = TREE_TYPE (TREE_TYPE (op0)); | |
541 | ||
542 | /* At which point we can try some of the same things as for indirects. */ | |
70f34814 | 543 | t = maybe_fold_offset_to_array_ref (loc, op0, op1); |
cbdd87d4 RG |
544 | if (t) |
545 | { | |
70f34814 RG |
546 | t = build_fold_addr_expr (t); |
547 | if (!useless_type_conversion_p (res_type, TREE_TYPE (t))) | |
548 | return NULL_TREE; | |
cbdd87d4 RG |
549 | SET_EXPR_LOCATION (t, loc); |
550 | } | |
551 | ||
552 | return t; | |
553 | } | |
554 | ||
555 | /* Subroutine of fold_stmt. We perform several simplifications of the | |
556 | memory reference tree EXPR and make sure to re-gimplify them properly | |
557 | after propagation of constant addresses. IS_LHS is true if the | |
558 | reference is supposed to be an lvalue. */ | |
559 | ||
560 | static tree | |
561 | maybe_fold_reference (tree expr, bool is_lhs) | |
562 | { | |
563 | tree *t = &expr; | |
17f39a39 | 564 | tree result; |
cbdd87d4 | 565 | |
f0eddb90 RG |
566 | if ((TREE_CODE (expr) == VIEW_CONVERT_EXPR |
567 | || TREE_CODE (expr) == REALPART_EXPR | |
568 | || TREE_CODE (expr) == IMAGPART_EXPR) | |
569 | && CONSTANT_CLASS_P (TREE_OPERAND (expr, 0))) | |
570 | return fold_unary_loc (EXPR_LOCATION (expr), | |
571 | TREE_CODE (expr), | |
572 | TREE_TYPE (expr), | |
573 | TREE_OPERAND (expr, 0)); | |
574 | else if (TREE_CODE (expr) == BIT_FIELD_REF | |
575 | && CONSTANT_CLASS_P (TREE_OPERAND (expr, 0))) | |
576 | return fold_ternary_loc (EXPR_LOCATION (expr), | |
577 | TREE_CODE (expr), | |
578 | TREE_TYPE (expr), | |
579 | TREE_OPERAND (expr, 0), | |
580 | TREE_OPERAND (expr, 1), | |
581 | TREE_OPERAND (expr, 2)); | |
582 | ||
583 | while (handled_component_p (*t)) | |
584 | t = &TREE_OPERAND (*t, 0); | |
cbdd87d4 | 585 | |
f0eddb90 RG |
586 | /* Canonicalize MEM_REFs invariant address operand. Do this first |
587 | to avoid feeding non-canonical MEM_REFs elsewhere. */ | |
588 | if (TREE_CODE (*t) == MEM_REF | |
589 | && !is_gimple_mem_ref_addr (TREE_OPERAND (*t, 0))) | |
cbdd87d4 | 590 | { |
f0eddb90 RG |
591 | bool volatile_p = TREE_THIS_VOLATILE (*t); |
592 | tree tem = fold_binary (MEM_REF, TREE_TYPE (*t), | |
593 | TREE_OPERAND (*t, 0), | |
594 | TREE_OPERAND (*t, 1)); | |
595 | if (tem) | |
596 | { | |
597 | TREE_THIS_VOLATILE (tem) = volatile_p; | |
598 | *t = tem; | |
599 | tem = maybe_fold_reference (expr, is_lhs); | |
600 | if (tem) | |
601 | return tem; | |
602 | return expr; | |
603 | } | |
cbdd87d4 RG |
604 | } |
605 | ||
f0eddb90 RG |
606 | if (!is_lhs |
607 | && (result = fold_const_aggregate_ref (expr)) | |
608 | && is_gimple_min_invariant (result)) | |
609 | return result; | |
cbdd87d4 | 610 | |
70f34814 RG |
611 | /* Fold back MEM_REFs to reference trees. */ |
612 | if (TREE_CODE (*t) == MEM_REF | |
613 | && TREE_CODE (TREE_OPERAND (*t, 0)) == ADDR_EXPR | |
614 | && integer_zerop (TREE_OPERAND (*t, 1)) | |
615 | && (TREE_THIS_VOLATILE (*t) | |
616 | == TREE_THIS_VOLATILE (TREE_OPERAND (TREE_OPERAND (*t, 0), 0))) | |
617 | && !TYPE_REF_CAN_ALIAS_ALL (TREE_TYPE (TREE_OPERAND (*t, 1))) | |
618 | && (TYPE_MAIN_VARIANT (TREE_TYPE (*t)) | |
619 | == TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (TREE_OPERAND (*t, 1))))) | |
620 | /* We have to look out here to not drop a required conversion | |
621 | from the rhs to the lhs if is_lhs, but we don't have the | |
622 | rhs here to verify that. Thus require strict type | |
623 | compatibility. */ | |
624 | && types_compatible_p (TREE_TYPE (*t), | |
625 | TREE_TYPE (TREE_OPERAND | |
f0eddb90 | 626 | (TREE_OPERAND (*t, 0), 0)))) |
cbdd87d4 | 627 | { |
70f34814 RG |
628 | tree tem; |
629 | *t = TREE_OPERAND (TREE_OPERAND (*t, 0), 0); | |
630 | tem = maybe_fold_reference (expr, is_lhs); | |
631 | if (tem) | |
632 | return tem; | |
633 | return expr; | |
634 | } | |
4d948885 RG |
635 | else if (TREE_CODE (*t) == TARGET_MEM_REF) |
636 | { | |
637 | tree tem = maybe_fold_tmr (*t); | |
638 | if (tem) | |
639 | { | |
640 | *t = tem; | |
641 | tem = maybe_fold_reference (expr, is_lhs); | |
642 | if (tem) | |
643 | return tem; | |
644 | return expr; | |
645 | } | |
646 | } | |
cbdd87d4 RG |
647 | |
648 | return NULL_TREE; | |
649 | } | |
650 | ||
651 | ||
652 | /* Attempt to fold an assignment statement pointed-to by SI. Returns a | |
653 | replacement rhs for the statement or NULL_TREE if no simplification | |
654 | could be made. It is assumed that the operands have been previously | |
655 | folded. */ | |
656 | ||
657 | static tree | |
658 | fold_gimple_assign (gimple_stmt_iterator *si) | |
659 | { | |
660 | gimple stmt = gsi_stmt (*si); | |
661 | enum tree_code subcode = gimple_assign_rhs_code (stmt); | |
662 | location_t loc = gimple_location (stmt); | |
663 | ||
664 | tree result = NULL_TREE; | |
665 | ||
666 | switch (get_gimple_rhs_class (subcode)) | |
667 | { | |
668 | case GIMPLE_SINGLE_RHS: | |
669 | { | |
670 | tree rhs = gimple_assign_rhs1 (stmt); | |
671 | ||
672 | /* Try to fold a conditional expression. */ | |
673 | if (TREE_CODE (rhs) == COND_EXPR) | |
674 | { | |
675 | tree op0 = COND_EXPR_COND (rhs); | |
676 | tree tem; | |
677 | bool set = false; | |
678 | location_t cond_loc = EXPR_LOCATION (rhs); | |
679 | ||
680 | if (COMPARISON_CLASS_P (op0)) | |
681 | { | |
682 | fold_defer_overflow_warnings (); | |
683 | tem = fold_binary_loc (cond_loc, | |
684 | TREE_CODE (op0), TREE_TYPE (op0), | |
685 | TREE_OPERAND (op0, 0), | |
686 | TREE_OPERAND (op0, 1)); | |
687 | /* This is actually a conditional expression, not a GIMPLE | |
688 | conditional statement, however, the valid_gimple_rhs_p | |
689 | test still applies. */ | |
690 | set = (tem && is_gimple_condexpr (tem) | |
691 | && valid_gimple_rhs_p (tem)); | |
692 | fold_undefer_overflow_warnings (set, stmt, 0); | |
693 | } | |
694 | else if (is_gimple_min_invariant (op0)) | |
695 | { | |
696 | tem = op0; | |
697 | set = true; | |
698 | } | |
699 | else | |
700 | return NULL_TREE; | |
701 | ||
702 | if (set) | |
703 | result = fold_build3_loc (cond_loc, COND_EXPR, TREE_TYPE (rhs), tem, | |
704 | COND_EXPR_THEN (rhs), COND_EXPR_ELSE (rhs)); | |
705 | } | |
706 | ||
cbdd87d4 RG |
707 | else if (REFERENCE_CLASS_P (rhs)) |
708 | return maybe_fold_reference (rhs, false); | |
709 | ||
710 | else if (TREE_CODE (rhs) == ADDR_EXPR) | |
711 | { | |
70f34814 RG |
712 | tree ref = TREE_OPERAND (rhs, 0); |
713 | tree tem = maybe_fold_reference (ref, true); | |
714 | if (tem | |
715 | && TREE_CODE (tem) == MEM_REF | |
716 | && integer_zerop (TREE_OPERAND (tem, 1))) | |
717 | result = fold_convert (TREE_TYPE (rhs), TREE_OPERAND (tem, 0)); | |
718 | else if (tem) | |
cbdd87d4 RG |
719 | result = fold_convert (TREE_TYPE (rhs), |
720 | build_fold_addr_expr_loc (loc, tem)); | |
70f34814 RG |
721 | else if (TREE_CODE (ref) == MEM_REF |
722 | && integer_zerop (TREE_OPERAND (ref, 1))) | |
723 | result = fold_convert (TREE_TYPE (rhs), TREE_OPERAND (ref, 0)); | |
cbdd87d4 RG |
724 | } |
725 | ||
726 | else if (TREE_CODE (rhs) == CONSTRUCTOR | |
727 | && TREE_CODE (TREE_TYPE (rhs)) == VECTOR_TYPE | |
728 | && (CONSTRUCTOR_NELTS (rhs) | |
729 | == TYPE_VECTOR_SUBPARTS (TREE_TYPE (rhs)))) | |
730 | { | |
731 | /* Fold a constant vector CONSTRUCTOR to VECTOR_CST. */ | |
732 | unsigned i; | |
733 | tree val; | |
734 | ||
735 | FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (rhs), i, val) | |
736 | if (TREE_CODE (val) != INTEGER_CST | |
737 | && TREE_CODE (val) != REAL_CST | |
738 | && TREE_CODE (val) != FIXED_CST) | |
739 | return NULL_TREE; | |
740 | ||
741 | return build_vector_from_ctor (TREE_TYPE (rhs), | |
742 | CONSTRUCTOR_ELTS (rhs)); | |
743 | } | |
744 | ||
745 | else if (DECL_P (rhs)) | |
746 | return unshare_expr (get_symbol_constant_value (rhs)); | |
747 | ||
748 | /* If we couldn't fold the RHS, hand over to the generic | |
749 | fold routines. */ | |
750 | if (result == NULL_TREE) | |
751 | result = fold (rhs); | |
752 | ||
753 | /* Strip away useless type conversions. Both the NON_LVALUE_EXPR | |
754 | that may have been added by fold, and "useless" type | |
755 | conversions that might now be apparent due to propagation. */ | |
756 | STRIP_USELESS_TYPE_CONVERSION (result); | |
757 | ||
758 | if (result != rhs && valid_gimple_rhs_p (result)) | |
759 | return result; | |
760 | ||
761 | return NULL_TREE; | |
762 | } | |
763 | break; | |
764 | ||
765 | case GIMPLE_UNARY_RHS: | |
766 | { | |
767 | tree rhs = gimple_assign_rhs1 (stmt); | |
768 | ||
769 | result = fold_unary_loc (loc, subcode, gimple_expr_type (stmt), rhs); | |
770 | if (result) | |
771 | { | |
772 | /* If the operation was a conversion do _not_ mark a | |
773 | resulting constant with TREE_OVERFLOW if the original | |
774 | constant was not. These conversions have implementation | |
775 | defined behavior and retaining the TREE_OVERFLOW flag | |
776 | here would confuse later passes such as VRP. */ | |
777 | if (CONVERT_EXPR_CODE_P (subcode) | |
778 | && TREE_CODE (result) == INTEGER_CST | |
779 | && TREE_CODE (rhs) == INTEGER_CST) | |
780 | TREE_OVERFLOW (result) = TREE_OVERFLOW (rhs); | |
781 | ||
782 | STRIP_USELESS_TYPE_CONVERSION (result); | |
783 | if (valid_gimple_rhs_p (result)) | |
784 | return result; | |
785 | } | |
786 | else if (CONVERT_EXPR_CODE_P (subcode) | |
787 | && POINTER_TYPE_P (gimple_expr_type (stmt)) | |
788 | && POINTER_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (stmt)))) | |
789 | { | |
790 | tree type = gimple_expr_type (stmt); | |
791 | tree t = maybe_fold_offset_to_address (loc, | |
792 | gimple_assign_rhs1 (stmt), | |
793 | integer_zero_node, type); | |
794 | if (t) | |
795 | return t; | |
796 | } | |
797 | } | |
798 | break; | |
799 | ||
800 | case GIMPLE_BINARY_RHS: | |
801 | /* Try to fold pointer addition. */ | |
802 | if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR) | |
803 | { | |
804 | tree type = TREE_TYPE (gimple_assign_rhs1 (stmt)); | |
805 | if (TREE_CODE (TREE_TYPE (type)) == ARRAY_TYPE) | |
806 | { | |
807 | type = build_pointer_type (TREE_TYPE (TREE_TYPE (type))); | |
808 | if (!useless_type_conversion_p | |
809 | (TREE_TYPE (gimple_assign_lhs (stmt)), type)) | |
810 | type = TREE_TYPE (gimple_assign_rhs1 (stmt)); | |
811 | } | |
812 | result = maybe_fold_stmt_addition (gimple_location (stmt), | |
813 | type, | |
814 | gimple_assign_rhs1 (stmt), | |
815 | gimple_assign_rhs2 (stmt)); | |
816 | } | |
817 | ||
818 | if (!result) | |
819 | result = fold_binary_loc (loc, subcode, | |
820 | TREE_TYPE (gimple_assign_lhs (stmt)), | |
821 | gimple_assign_rhs1 (stmt), | |
822 | gimple_assign_rhs2 (stmt)); | |
823 | ||
824 | if (result) | |
825 | { | |
826 | STRIP_USELESS_TYPE_CONVERSION (result); | |
827 | if (valid_gimple_rhs_p (result)) | |
828 | return result; | |
829 | ||
830 | /* Fold might have produced non-GIMPLE, so if we trust it blindly | |
831 | we lose canonicalization opportunities. Do not go again | |
832 | through fold here though, or the same non-GIMPLE will be | |
833 | produced. */ | |
834 | if (commutative_tree_code (subcode) | |
835 | && tree_swap_operands_p (gimple_assign_rhs1 (stmt), | |
836 | gimple_assign_rhs2 (stmt), false)) | |
837 | return build2 (subcode, TREE_TYPE (gimple_assign_lhs (stmt)), | |
838 | gimple_assign_rhs2 (stmt), | |
839 | gimple_assign_rhs1 (stmt)); | |
840 | } | |
841 | break; | |
842 | ||
0354c0c7 BS |
843 | case GIMPLE_TERNARY_RHS: |
844 | result = fold_ternary_loc (loc, subcode, | |
845 | TREE_TYPE (gimple_assign_lhs (stmt)), | |
846 | gimple_assign_rhs1 (stmt), | |
847 | gimple_assign_rhs2 (stmt), | |
848 | gimple_assign_rhs3 (stmt)); | |
849 | ||
850 | if (result) | |
851 | { | |
852 | STRIP_USELESS_TYPE_CONVERSION (result); | |
853 | if (valid_gimple_rhs_p (result)) | |
854 | return result; | |
855 | ||
856 | /* Fold might have produced non-GIMPLE, so if we trust it blindly | |
857 | we lose canonicalization opportunities. Do not go again | |
858 | through fold here though, or the same non-GIMPLE will be | |
859 | produced. */ | |
860 | if (commutative_ternary_tree_code (subcode) | |
861 | && tree_swap_operands_p (gimple_assign_rhs1 (stmt), | |
862 | gimple_assign_rhs2 (stmt), false)) | |
863 | return build3 (subcode, TREE_TYPE (gimple_assign_lhs (stmt)), | |
864 | gimple_assign_rhs2 (stmt), | |
865 | gimple_assign_rhs1 (stmt), | |
866 | gimple_assign_rhs3 (stmt)); | |
867 | } | |
868 | break; | |
869 | ||
cbdd87d4 RG |
870 | case GIMPLE_INVALID_RHS: |
871 | gcc_unreachable (); | |
872 | } | |
873 | ||
874 | return NULL_TREE; | |
875 | } | |
876 | ||
877 | /* Attempt to fold a conditional statement. Return true if any changes were | |
878 | made. We only attempt to fold the condition expression, and do not perform | |
879 | any transformation that would require alteration of the cfg. It is | |
880 | assumed that the operands have been previously folded. */ | |
881 | ||
882 | static bool | |
883 | fold_gimple_cond (gimple stmt) | |
884 | { | |
885 | tree result = fold_binary_loc (gimple_location (stmt), | |
886 | gimple_cond_code (stmt), | |
887 | boolean_type_node, | |
888 | gimple_cond_lhs (stmt), | |
889 | gimple_cond_rhs (stmt)); | |
890 | ||
891 | if (result) | |
892 | { | |
893 | STRIP_USELESS_TYPE_CONVERSION (result); | |
894 | if (is_gimple_condexpr (result) && valid_gimple_rhs_p (result)) | |
895 | { | |
896 | gimple_cond_set_condition_from_tree (stmt, result); | |
897 | return true; | |
898 | } | |
899 | } | |
900 | ||
901 | return false; | |
902 | } | |
903 | ||
904 | /* Convert EXPR into a GIMPLE value suitable for substitution on the | |
905 | RHS of an assignment. Insert the necessary statements before | |
906 | iterator *SI_P. The statement at *SI_P, which must be a GIMPLE_CALL | |
907 | is replaced. If the call is expected to produces a result, then it | |
908 | is replaced by an assignment of the new RHS to the result variable. | |
909 | If the result is to be ignored, then the call is replaced by a | |
fe2ef088 MM |
910 | GIMPLE_NOP. A proper VDEF chain is retained by making the first |
911 | VUSE and the last VDEF of the whole sequence be the same as the replaced | |
912 | statement and using new SSA names for stores in between. */ | |
cbdd87d4 RG |
913 | |
914 | void | |
915 | gimplify_and_update_call_from_tree (gimple_stmt_iterator *si_p, tree expr) | |
916 | { | |
917 | tree lhs; | |
918 | tree tmp = NULL_TREE; /* Silence warning. */ | |
919 | gimple stmt, new_stmt; | |
920 | gimple_stmt_iterator i; | |
921 | gimple_seq stmts = gimple_seq_alloc(); | |
922 | struct gimplify_ctx gctx; | |
923 | gimple last = NULL; | |
fe2ef088 MM |
924 | gimple laststore = NULL; |
925 | tree reaching_vuse; | |
cbdd87d4 RG |
926 | |
927 | stmt = gsi_stmt (*si_p); | |
928 | ||
929 | gcc_assert (is_gimple_call (stmt)); | |
930 | ||
931 | lhs = gimple_call_lhs (stmt); | |
fe2ef088 | 932 | reaching_vuse = gimple_vuse (stmt); |
cbdd87d4 RG |
933 | |
934 | push_gimplify_context (&gctx); | |
935 | ||
936 | if (lhs == NULL_TREE) | |
6e572326 RG |
937 | { |
938 | gimplify_and_add (expr, &stmts); | |
939 | /* We can end up with folding a memcpy of an empty class assignment | |
940 | which gets optimized away by C++ gimplification. */ | |
941 | if (gimple_seq_empty_p (stmts)) | |
942 | { | |
9fdc58de | 943 | pop_gimplify_context (NULL); |
6e572326 RG |
944 | if (gimple_in_ssa_p (cfun)) |
945 | { | |
946 | unlink_stmt_vdef (stmt); | |
947 | release_defs (stmt); | |
948 | } | |
949 | gsi_remove (si_p, true); | |
950 | return; | |
951 | } | |
952 | } | |
cbdd87d4 RG |
953 | else |
954 | tmp = get_initialized_tmp_var (expr, &stmts, NULL); | |
955 | ||
956 | pop_gimplify_context (NULL); | |
957 | ||
958 | if (gimple_has_location (stmt)) | |
959 | annotate_all_with_location (stmts, gimple_location (stmt)); | |
960 | ||
961 | /* The replacement can expose previously unreferenced variables. */ | |
962 | for (i = gsi_start (stmts); !gsi_end_p (i); gsi_next (&i)) | |
963 | { | |
964 | if (last) | |
965 | { | |
966 | gsi_insert_before (si_p, last, GSI_NEW_STMT); | |
967 | gsi_next (si_p); | |
968 | } | |
969 | new_stmt = gsi_stmt (i); | |
edc74207 RG |
970 | if (gimple_in_ssa_p (cfun)) |
971 | { | |
972 | find_new_referenced_vars (new_stmt); | |
973 | mark_symbols_for_renaming (new_stmt); | |
974 | } | |
fe2ef088 MM |
975 | /* If the new statement has a VUSE, update it with exact SSA name we |
976 | know will reach this one. */ | |
977 | if (gimple_vuse (new_stmt)) | |
978 | { | |
979 | /* If we've also seen a previous store create a new VDEF for | |
980 | the latter one, and make that the new reaching VUSE. */ | |
981 | if (laststore) | |
982 | { | |
983 | reaching_vuse = make_ssa_name (gimple_vop (cfun), laststore); | |
984 | gimple_set_vdef (laststore, reaching_vuse); | |
985 | update_stmt (laststore); | |
986 | laststore = NULL; | |
987 | } | |
988 | gimple_set_vuse (new_stmt, reaching_vuse); | |
989 | gimple_set_modified (new_stmt, true); | |
990 | } | |
991 | if (gimple_assign_single_p (new_stmt) | |
992 | && !is_gimple_reg (gimple_assign_lhs (new_stmt))) | |
993 | { | |
994 | laststore = new_stmt; | |
995 | } | |
cbdd87d4 RG |
996 | last = new_stmt; |
997 | } | |
998 | ||
999 | if (lhs == NULL_TREE) | |
1000 | { | |
fe2ef088 MM |
1001 | /* If we replace a call without LHS that has a VDEF and our new |
1002 | sequence ends with a store we must make that store have the same | |
1003 | vdef in order not to break the sequencing. This can happen | |
1004 | for instance when folding memcpy calls into assignments. */ | |
1005 | if (gimple_vdef (stmt) && laststore) | |
1006 | { | |
1007 | gimple_set_vdef (laststore, gimple_vdef (stmt)); | |
8a1561bc MM |
1008 | if (TREE_CODE (gimple_vdef (stmt)) == SSA_NAME) |
1009 | SSA_NAME_DEF_STMT (gimple_vdef (stmt)) = laststore; | |
fe2ef088 MM |
1010 | update_stmt (laststore); |
1011 | } | |
edc74207 | 1012 | else if (gimple_in_ssa_p (cfun)) |
fe2ef088 MM |
1013 | { |
1014 | unlink_stmt_vdef (stmt); | |
1015 | release_defs (stmt); | |
1016 | } | |
cbdd87d4 RG |
1017 | new_stmt = last; |
1018 | } | |
1019 | else | |
1020 | { | |
1021 | if (last) | |
1022 | { | |
1023 | gsi_insert_before (si_p, last, GSI_NEW_STMT); | |
1024 | gsi_next (si_p); | |
1025 | } | |
8a1561bc MM |
1026 | if (laststore && is_gimple_reg (lhs)) |
1027 | { | |
1028 | gimple_set_vdef (laststore, gimple_vdef (stmt)); | |
1029 | update_stmt (laststore); | |
1030 | if (TREE_CODE (gimple_vdef (stmt)) == SSA_NAME) | |
1031 | SSA_NAME_DEF_STMT (gimple_vdef (stmt)) = laststore; | |
1032 | laststore = NULL; | |
1033 | } | |
1034 | else if (laststore) | |
fe2ef088 MM |
1035 | { |
1036 | reaching_vuse = make_ssa_name (gimple_vop (cfun), laststore); | |
1037 | gimple_set_vdef (laststore, reaching_vuse); | |
1038 | update_stmt (laststore); | |
1039 | laststore = NULL; | |
1040 | } | |
cbdd87d4 | 1041 | new_stmt = gimple_build_assign (lhs, tmp); |
8a1561bc MM |
1042 | if (!is_gimple_reg (tmp)) |
1043 | gimple_set_vuse (new_stmt, reaching_vuse); | |
1044 | if (!is_gimple_reg (lhs)) | |
1045 | { | |
1046 | gimple_set_vdef (new_stmt, gimple_vdef (stmt)); | |
1047 | if (TREE_CODE (gimple_vdef (stmt)) == SSA_NAME) | |
1048 | SSA_NAME_DEF_STMT (gimple_vdef (stmt)) = new_stmt; | |
1049 | } | |
07db7d35 RG |
1050 | else if (reaching_vuse == gimple_vuse (stmt)) |
1051 | unlink_stmt_vdef (stmt); | |
cbdd87d4 RG |
1052 | } |
1053 | ||
1054 | gimple_set_location (new_stmt, gimple_location (stmt)); | |
1055 | gsi_replace (si_p, new_stmt, false); | |
1056 | } | |
1057 | ||
1058 | /* Return the string length, maximum string length or maximum value of | |
1059 | ARG in LENGTH. | |
1060 | If ARG is an SSA name variable, follow its use-def chains. If LENGTH | |
1061 | is not NULL and, for TYPE == 0, its value is not equal to the length | |
1062 | we determine or if we are unable to determine the length or value, | |
1063 | return false. VISITED is a bitmap of visited variables. | |
1064 | TYPE is 0 if string length should be returned, 1 for maximum string | |
1065 | length and 2 for maximum value ARG can have. */ | |
1066 | ||
1067 | static bool | |
1068 | get_maxval_strlen (tree arg, tree *length, bitmap visited, int type) | |
1069 | { | |
1070 | tree var, val; | |
1071 | gimple def_stmt; | |
1072 | ||
1073 | if (TREE_CODE (arg) != SSA_NAME) | |
1074 | { | |
1075 | if (TREE_CODE (arg) == COND_EXPR) | |
1076 | return get_maxval_strlen (COND_EXPR_THEN (arg), length, visited, type) | |
1077 | && get_maxval_strlen (COND_EXPR_ELSE (arg), length, visited, type); | |
1078 | /* We can end up with &(*iftmp_1)[0] here as well, so handle it. */ | |
1079 | else if (TREE_CODE (arg) == ADDR_EXPR | |
1080 | && TREE_CODE (TREE_OPERAND (arg, 0)) == ARRAY_REF | |
1081 | && integer_zerop (TREE_OPERAND (TREE_OPERAND (arg, 0), 1))) | |
1082 | { | |
1083 | tree aop0 = TREE_OPERAND (TREE_OPERAND (arg, 0), 0); | |
1084 | if (TREE_CODE (aop0) == INDIRECT_REF | |
1085 | && TREE_CODE (TREE_OPERAND (aop0, 0)) == SSA_NAME) | |
1086 | return get_maxval_strlen (TREE_OPERAND (aop0, 0), | |
1087 | length, visited, type); | |
1088 | } | |
1089 | ||
1090 | if (type == 2) | |
1091 | { | |
1092 | val = arg; | |
1093 | if (TREE_CODE (val) != INTEGER_CST | |
1094 | || tree_int_cst_sgn (val) < 0) | |
1095 | return false; | |
1096 | } | |
1097 | else | |
1098 | val = c_strlen (arg, 1); | |
1099 | if (!val) | |
1100 | return false; | |
1101 | ||
1102 | if (*length) | |
1103 | { | |
1104 | if (type > 0) | |
1105 | { | |
1106 | if (TREE_CODE (*length) != INTEGER_CST | |
1107 | || TREE_CODE (val) != INTEGER_CST) | |
1108 | return false; | |
1109 | ||
1110 | if (tree_int_cst_lt (*length, val)) | |
1111 | *length = val; | |
1112 | return true; | |
1113 | } | |
1114 | else if (simple_cst_equal (val, *length) != 1) | |
1115 | return false; | |
1116 | } | |
1117 | ||
1118 | *length = val; | |
1119 | return true; | |
1120 | } | |
1121 | ||
1122 | /* If we were already here, break the infinite cycle. */ | |
fcaa4ca4 | 1123 | if (!bitmap_set_bit (visited, SSA_NAME_VERSION (arg))) |
cbdd87d4 | 1124 | return true; |
cbdd87d4 RG |
1125 | |
1126 | var = arg; | |
1127 | def_stmt = SSA_NAME_DEF_STMT (var); | |
1128 | ||
1129 | switch (gimple_code (def_stmt)) | |
1130 | { | |
1131 | case GIMPLE_ASSIGN: | |
1132 | /* The RHS of the statement defining VAR must either have a | |
1133 | constant length or come from another SSA_NAME with a constant | |
1134 | length. */ | |
1135 | if (gimple_assign_single_p (def_stmt) | |
1136 | || gimple_assign_unary_nop_p (def_stmt)) | |
1137 | { | |
1138 | tree rhs = gimple_assign_rhs1 (def_stmt); | |
1139 | return get_maxval_strlen (rhs, length, visited, type); | |
1140 | } | |
1141 | return false; | |
1142 | ||
1143 | case GIMPLE_PHI: | |
1144 | { | |
1145 | /* All the arguments of the PHI node must have the same constant | |
1146 | length. */ | |
1147 | unsigned i; | |
1148 | ||
1149 | for (i = 0; i < gimple_phi_num_args (def_stmt); i++) | |
1150 | { | |
1151 | tree arg = gimple_phi_arg (def_stmt, i)->def; | |
1152 | ||
1153 | /* If this PHI has itself as an argument, we cannot | |
1154 | determine the string length of this argument. However, | |
1155 | if we can find a constant string length for the other | |
1156 | PHI args then we can still be sure that this is a | |
1157 | constant string length. So be optimistic and just | |
1158 | continue with the next argument. */ | |
1159 | if (arg == gimple_phi_result (def_stmt)) | |
1160 | continue; | |
1161 | ||
1162 | if (!get_maxval_strlen (arg, length, visited, type)) | |
1163 | return false; | |
1164 | } | |
1165 | } | |
1166 | return true; | |
1167 | ||
1168 | default: | |
1169 | return false; | |
1170 | } | |
1171 | } | |
1172 | ||
1173 | ||
1174 | /* Fold builtin call in statement STMT. Returns a simplified tree. | |
1175 | We may return a non-constant expression, including another call | |
1176 | to a different function and with different arguments, e.g., | |
1177 | substituting memcpy for strcpy when the string length is known. | |
1178 | Note that some builtins expand into inline code that may not | |
1179 | be valid in GIMPLE. Callers must take care. */ | |
1180 | ||
1181 | tree | |
1182 | gimple_fold_builtin (gimple stmt) | |
1183 | { | |
1184 | tree result, val[3]; | |
1185 | tree callee, a; | |
1186 | int arg_idx, type; | |
1187 | bitmap visited; | |
1188 | bool ignore; | |
1189 | int nargs; | |
1190 | location_t loc = gimple_location (stmt); | |
1191 | ||
1192 | gcc_assert (is_gimple_call (stmt)); | |
1193 | ||
1194 | ignore = (gimple_call_lhs (stmt) == NULL); | |
1195 | ||
1196 | /* First try the generic builtin folder. If that succeeds, return the | |
1197 | result directly. */ | |
1198 | result = fold_call_stmt (stmt, ignore); | |
1199 | if (result) | |
1200 | { | |
1201 | if (ignore) | |
1202 | STRIP_NOPS (result); | |
1203 | return result; | |
1204 | } | |
1205 | ||
1206 | /* Ignore MD builtins. */ | |
1207 | callee = gimple_call_fndecl (stmt); | |
1208 | if (DECL_BUILT_IN_CLASS (callee) == BUILT_IN_MD) | |
1209 | return NULL_TREE; | |
1210 | ||
1211 | /* If the builtin could not be folded, and it has no argument list, | |
1212 | we're done. */ | |
1213 | nargs = gimple_call_num_args (stmt); | |
1214 | if (nargs == 0) | |
1215 | return NULL_TREE; | |
1216 | ||
1217 | /* Limit the work only for builtins we know how to simplify. */ | |
1218 | switch (DECL_FUNCTION_CODE (callee)) | |
1219 | { | |
1220 | case BUILT_IN_STRLEN: | |
1221 | case BUILT_IN_FPUTS: | |
1222 | case BUILT_IN_FPUTS_UNLOCKED: | |
1223 | arg_idx = 0; | |
1224 | type = 0; | |
1225 | break; | |
1226 | case BUILT_IN_STRCPY: | |
1227 | case BUILT_IN_STRNCPY: | |
1228 | arg_idx = 1; | |
1229 | type = 0; | |
1230 | break; | |
1231 | case BUILT_IN_MEMCPY_CHK: | |
1232 | case BUILT_IN_MEMPCPY_CHK: | |
1233 | case BUILT_IN_MEMMOVE_CHK: | |
1234 | case BUILT_IN_MEMSET_CHK: | |
1235 | case BUILT_IN_STRNCPY_CHK: | |
1236 | arg_idx = 2; | |
1237 | type = 2; | |
1238 | break; | |
1239 | case BUILT_IN_STRCPY_CHK: | |
1240 | case BUILT_IN_STPCPY_CHK: | |
1241 | arg_idx = 1; | |
1242 | type = 1; | |
1243 | break; | |
1244 | case BUILT_IN_SNPRINTF_CHK: | |
1245 | case BUILT_IN_VSNPRINTF_CHK: | |
1246 | arg_idx = 1; | |
1247 | type = 2; | |
1248 | break; | |
1249 | default: | |
1250 | return NULL_TREE; | |
1251 | } | |
1252 | ||
1253 | if (arg_idx >= nargs) | |
1254 | return NULL_TREE; | |
1255 | ||
1256 | /* Try to use the dataflow information gathered by the CCP process. */ | |
1257 | visited = BITMAP_ALLOC (NULL); | |
1258 | bitmap_clear (visited); | |
1259 | ||
1260 | memset (val, 0, sizeof (val)); | |
1261 | a = gimple_call_arg (stmt, arg_idx); | |
1262 | if (!get_maxval_strlen (a, &val[arg_idx], visited, type)) | |
1263 | val[arg_idx] = NULL_TREE; | |
1264 | ||
1265 | BITMAP_FREE (visited); | |
1266 | ||
1267 | result = NULL_TREE; | |
1268 | switch (DECL_FUNCTION_CODE (callee)) | |
1269 | { | |
1270 | case BUILT_IN_STRLEN: | |
1271 | if (val[0] && nargs == 1) | |
1272 | { | |
1273 | tree new_val = | |
1274 | fold_convert (TREE_TYPE (gimple_call_lhs (stmt)), val[0]); | |
1275 | ||
1276 | /* If the result is not a valid gimple value, or not a cast | |
6e4da084 | 1277 | of a valid gimple value, then we cannot use the result. */ |
cbdd87d4 | 1278 | if (is_gimple_val (new_val) |
3dbe9454 | 1279 | || (CONVERT_EXPR_P (new_val) |
cbdd87d4 RG |
1280 | && is_gimple_val (TREE_OPERAND (new_val, 0)))) |
1281 | return new_val; | |
1282 | } | |
1283 | break; | |
1284 | ||
1285 | case BUILT_IN_STRCPY: | |
1286 | if (val[1] && is_gimple_val (val[1]) && nargs == 2) | |
1287 | result = fold_builtin_strcpy (loc, callee, | |
1288 | gimple_call_arg (stmt, 0), | |
1289 | gimple_call_arg (stmt, 1), | |
1290 | val[1]); | |
1291 | break; | |
1292 | ||
1293 | case BUILT_IN_STRNCPY: | |
1294 | if (val[1] && is_gimple_val (val[1]) && nargs == 3) | |
1295 | result = fold_builtin_strncpy (loc, callee, | |
1296 | gimple_call_arg (stmt, 0), | |
1297 | gimple_call_arg (stmt, 1), | |
1298 | gimple_call_arg (stmt, 2), | |
1299 | val[1]); | |
1300 | break; | |
1301 | ||
1302 | case BUILT_IN_FPUTS: | |
1303 | if (nargs == 2) | |
1304 | result = fold_builtin_fputs (loc, gimple_call_arg (stmt, 0), | |
1305 | gimple_call_arg (stmt, 1), | |
1306 | ignore, false, val[0]); | |
1307 | break; | |
1308 | ||
1309 | case BUILT_IN_FPUTS_UNLOCKED: | |
1310 | if (nargs == 2) | |
1311 | result = fold_builtin_fputs (loc, gimple_call_arg (stmt, 0), | |
1312 | gimple_call_arg (stmt, 1), | |
1313 | ignore, true, val[0]); | |
1314 | break; | |
1315 | ||
1316 | case BUILT_IN_MEMCPY_CHK: | |
1317 | case BUILT_IN_MEMPCPY_CHK: | |
1318 | case BUILT_IN_MEMMOVE_CHK: | |
1319 | case BUILT_IN_MEMSET_CHK: | |
1320 | if (val[2] && is_gimple_val (val[2]) && nargs == 4) | |
1321 | result = fold_builtin_memory_chk (loc, callee, | |
1322 | gimple_call_arg (stmt, 0), | |
1323 | gimple_call_arg (stmt, 1), | |
1324 | gimple_call_arg (stmt, 2), | |
1325 | gimple_call_arg (stmt, 3), | |
1326 | val[2], ignore, | |
1327 | DECL_FUNCTION_CODE (callee)); | |
1328 | break; | |
1329 | ||
1330 | case BUILT_IN_STRCPY_CHK: | |
1331 | case BUILT_IN_STPCPY_CHK: | |
1332 | if (val[1] && is_gimple_val (val[1]) && nargs == 3) | |
1333 | result = fold_builtin_stxcpy_chk (loc, callee, | |
1334 | gimple_call_arg (stmt, 0), | |
1335 | gimple_call_arg (stmt, 1), | |
1336 | gimple_call_arg (stmt, 2), | |
1337 | val[1], ignore, | |
1338 | DECL_FUNCTION_CODE (callee)); | |
1339 | break; | |
1340 | ||
1341 | case BUILT_IN_STRNCPY_CHK: | |
1342 | if (val[2] && is_gimple_val (val[2]) && nargs == 4) | |
1343 | result = fold_builtin_strncpy_chk (loc, gimple_call_arg (stmt, 0), | |
1344 | gimple_call_arg (stmt, 1), | |
1345 | gimple_call_arg (stmt, 2), | |
1346 | gimple_call_arg (stmt, 3), | |
1347 | val[2]); | |
1348 | break; | |
1349 | ||
1350 | case BUILT_IN_SNPRINTF_CHK: | |
1351 | case BUILT_IN_VSNPRINTF_CHK: | |
1352 | if (val[1] && is_gimple_val (val[1])) | |
1353 | result = gimple_fold_builtin_snprintf_chk (stmt, val[1], | |
1354 | DECL_FUNCTION_CODE (callee)); | |
1355 | break; | |
1356 | ||
1357 | default: | |
1358 | gcc_unreachable (); | |
1359 | } | |
1360 | ||
1361 | if (result && ignore) | |
1362 | result = fold_ignored_result (result); | |
1363 | return result; | |
1364 | } | |
1365 | ||
ceeffab0 MJ |
1366 | /* Return a declaration of a function which an OBJ_TYPE_REF references. TOKEN |
1367 | is integer form of OBJ_TYPE_REF_TOKEN of the reference expression. | |
1368 | KNOWN_BINFO carries the binfo describing the true type of | |
1369 | OBJ_TYPE_REF_OBJECT(REF). If a call to the function must be accompanied | |
1370 | with a this adjustment, the constant which should be added to this pointer | |
1371 | is stored to *DELTA. If REFUSE_THUNKS is true, return NULL if the function | |
1372 | is a thunk (other than a this adjustment which is dealt with by DELTA). */ | |
1ae6fe9b MJ |
1373 | |
1374 | tree | |
84825707 | 1375 | gimple_get_virt_method_for_binfo (HOST_WIDE_INT token, tree known_binfo, |
ceeffab0 | 1376 | tree *delta, bool refuse_thunks) |
1ae6fe9b MJ |
1377 | { |
1378 | HOST_WIDE_INT i; | |
ceeffab0 MJ |
1379 | tree v, fndecl; |
1380 | struct cgraph_node *node; | |
1ae6fe9b MJ |
1381 | |
1382 | v = BINFO_VIRTUALS (known_binfo); | |
ceeffab0 MJ |
1383 | /* If there is no virtual methods leave the OBJ_TYPE_REF alone. */ |
1384 | if (!v) | |
1385 | return NULL_TREE; | |
1ae6fe9b MJ |
1386 | i = 0; |
1387 | while (i != token) | |
1388 | { | |
1389 | i += (TARGET_VTABLE_USES_DESCRIPTORS | |
1390 | ? TARGET_VTABLE_USES_DESCRIPTORS : 1); | |
1391 | v = TREE_CHAIN (v); | |
1392 | } | |
1393 | ||
84825707 JJ |
1394 | /* If BV_VCALL_INDEX is non-NULL, give up. */ |
1395 | if (TREE_TYPE (v)) | |
1396 | return NULL_TREE; | |
1397 | ||
1ae6fe9b | 1398 | fndecl = TREE_VALUE (v); |
ceeffab0 MJ |
1399 | node = cgraph_get_node_or_alias (fndecl); |
1400 | if (refuse_thunks | |
1401 | && (!node | |
1402 | /* Bail out if it is a thunk declaration. Since simple this_adjusting | |
1403 | thunks are represented by a constant in TREE_PURPOSE of items in | |
1404 | BINFO_VIRTUALS, this is a more complicate type which we cannot handle as | |
1405 | yet. | |
1406 | ||
1407 | FIXME: Remove the following condition once we are able to represent | |
1408 | thunk information on call graph edges. */ | |
1409 | || (node->same_body_alias && node->thunk.thunk_p))) | |
1410 | return NULL_TREE; | |
3f1f0ae3 | 1411 | |
6e4da084 JH |
1412 | /* When cgraph node is missing and function is not public, we cannot |
1413 | devirtualize. This can happen in WHOPR when the actual method | |
1414 | ends up in other partition, because we found devirtualization | |
1415 | possibility too late. */ | |
ceeffab0 MJ |
1416 | if (!can_refer_decl_in_current_unit_p (TREE_VALUE (v))) |
1417 | return NULL_TREE; | |
1418 | ||
1419 | *delta = TREE_PURPOSE (v); | |
1420 | gcc_checking_assert (host_integerp (*delta, 0)); | |
1421 | return fndecl; | |
1ae6fe9b MJ |
1422 | } |
1423 | ||
ceeffab0 MJ |
1424 | /* Generate code adjusting the first parameter of a call statement determined |
1425 | by GSI by DELTA. */ | |
1426 | ||
1427 | void | |
1428 | gimple_adjust_this_by_delta (gimple_stmt_iterator *gsi, tree delta) | |
1429 | { | |
1430 | gimple call_stmt = gsi_stmt (*gsi); | |
1431 | tree parm, tmp; | |
1432 | gimple new_stmt; | |
1433 | ||
1434 | delta = fold_convert (sizetype, delta); | |
1435 | gcc_assert (gimple_call_num_args (call_stmt) >= 1); | |
1436 | parm = gimple_call_arg (call_stmt, 0); | |
1437 | gcc_assert (POINTER_TYPE_P (TREE_TYPE (parm))); | |
1438 | tmp = create_tmp_var (TREE_TYPE (parm), NULL); | |
1439 | add_referenced_var (tmp); | |
1440 | ||
1441 | tmp = make_ssa_name (tmp, NULL); | |
1442 | new_stmt = gimple_build_assign_with_ops (POINTER_PLUS_EXPR, tmp, parm, delta); | |
1443 | SSA_NAME_DEF_STMT (tmp) = new_stmt; | |
1444 | gsi_insert_before (gsi, new_stmt, GSI_SAME_STMT); | |
1445 | gimple_call_set_arg (call_stmt, 0, tmp); | |
1446 | } | |
1ae6fe9b | 1447 | |
cbdd87d4 RG |
1448 | /* Attempt to fold a call statement referenced by the statement iterator GSI. |
1449 | The statement may be replaced by another statement, e.g., if the call | |
1450 | simplifies to a constant value. Return true if any changes were made. | |
1451 | It is assumed that the operands have been previously folded. */ | |
1452 | ||
ceeffab0 MJ |
1453 | bool |
1454 | gimple_fold_call (gimple_stmt_iterator *gsi, bool inplace) | |
cbdd87d4 RG |
1455 | { |
1456 | gimple stmt = gsi_stmt (*gsi); | |
3b45a007 | 1457 | tree callee; |
cbdd87d4 RG |
1458 | |
1459 | /* Check for builtins that CCP can handle using information not | |
1460 | available in the generic fold routines. */ | |
3b45a007 | 1461 | callee = gimple_call_fndecl (stmt); |
23c1da7a | 1462 | if (!inplace && callee && DECL_BUILT_IN (callee)) |
cbdd87d4 RG |
1463 | { |
1464 | tree result = gimple_fold_builtin (stmt); | |
1465 | ||
1466 | if (result) | |
1467 | { | |
1468 | if (!update_call_from_tree (gsi, result)) | |
1469 | gimplify_and_update_call_from_tree (gsi, result); | |
1470 | return true; | |
1471 | } | |
1472 | } | |
3b45a007 RG |
1473 | |
1474 | /* Check for virtual calls that became direct calls. */ | |
1475 | callee = gimple_call_fn (stmt); | |
1476 | if (TREE_CODE (callee) == OBJ_TYPE_REF | |
1477 | && gimple_call_addr_fndecl (OBJ_TYPE_REF_EXPR (callee)) != NULL_TREE) | |
1478 | { | |
1479 | gimple_call_set_fn (stmt, OBJ_TYPE_REF_EXPR (callee)); | |
1480 | return true; | |
1481 | } | |
1482 | ||
cbdd87d4 RG |
1483 | return false; |
1484 | } | |
1485 | ||
1486 | /* Worker for both fold_stmt and fold_stmt_inplace. The INPLACE argument | |
1487 | distinguishes both cases. */ | |
1488 | ||
1489 | static bool | |
1490 | fold_stmt_1 (gimple_stmt_iterator *gsi, bool inplace) | |
1491 | { | |
1492 | bool changed = false; | |
1493 | gimple stmt = gsi_stmt (*gsi); | |
1494 | unsigned i; | |
1495 | ||
1496 | /* Fold the main computation performed by the statement. */ | |
1497 | switch (gimple_code (stmt)) | |
1498 | { | |
1499 | case GIMPLE_ASSIGN: | |
1500 | { | |
1501 | unsigned old_num_ops = gimple_num_ops (stmt); | |
1502 | tree new_rhs = fold_gimple_assign (gsi); | |
1503 | tree lhs = gimple_assign_lhs (stmt); | |
1504 | if (new_rhs | |
1505 | && !useless_type_conversion_p (TREE_TYPE (lhs), | |
1506 | TREE_TYPE (new_rhs))) | |
1507 | new_rhs = fold_convert (TREE_TYPE (lhs), new_rhs); | |
1508 | if (new_rhs | |
1509 | && (!inplace | |
1510 | || get_gimple_rhs_num_ops (TREE_CODE (new_rhs)) < old_num_ops)) | |
1511 | { | |
1512 | gimple_assign_set_rhs_from_tree (gsi, new_rhs); | |
1513 | changed = true; | |
1514 | } | |
1515 | break; | |
1516 | } | |
1517 | ||
1518 | case GIMPLE_COND: | |
1519 | changed |= fold_gimple_cond (stmt); | |
1520 | break; | |
1521 | ||
1522 | case GIMPLE_CALL: | |
1523 | /* Fold *& in call arguments. */ | |
1524 | for (i = 0; i < gimple_call_num_args (stmt); ++i) | |
1525 | if (REFERENCE_CLASS_P (gimple_call_arg (stmt, i))) | |
1526 | { | |
1527 | tree tmp = maybe_fold_reference (gimple_call_arg (stmt, i), false); | |
1528 | if (tmp) | |
1529 | { | |
1530 | gimple_call_set_arg (stmt, i, tmp); | |
1531 | changed = true; | |
1532 | } | |
1533 | } | |
ceeffab0 | 1534 | changed |= gimple_fold_call (gsi, inplace); |
cbdd87d4 RG |
1535 | break; |
1536 | ||
1537 | case GIMPLE_ASM: | |
1538 | /* Fold *& in asm operands. */ | |
1539 | for (i = 0; i < gimple_asm_noutputs (stmt); ++i) | |
1540 | { | |
1541 | tree link = gimple_asm_output_op (stmt, i); | |
1542 | tree op = TREE_VALUE (link); | |
1543 | if (REFERENCE_CLASS_P (op) | |
1544 | && (op = maybe_fold_reference (op, true)) != NULL_TREE) | |
1545 | { | |
1546 | TREE_VALUE (link) = op; | |
1547 | changed = true; | |
1548 | } | |
1549 | } | |
1550 | for (i = 0; i < gimple_asm_ninputs (stmt); ++i) | |
1551 | { | |
1552 | tree link = gimple_asm_input_op (stmt, i); | |
1553 | tree op = TREE_VALUE (link); | |
1554 | if (REFERENCE_CLASS_P (op) | |
1555 | && (op = maybe_fold_reference (op, false)) != NULL_TREE) | |
1556 | { | |
1557 | TREE_VALUE (link) = op; | |
1558 | changed = true; | |
1559 | } | |
1560 | } | |
1561 | break; | |
1562 | ||
bd422c4a RG |
1563 | case GIMPLE_DEBUG: |
1564 | if (gimple_debug_bind_p (stmt)) | |
1565 | { | |
1566 | tree val = gimple_debug_bind_get_value (stmt); | |
1567 | if (val | |
1568 | && REFERENCE_CLASS_P (val)) | |
1569 | { | |
1570 | tree tem = maybe_fold_reference (val, false); | |
1571 | if (tem) | |
1572 | { | |
1573 | gimple_debug_bind_set_value (stmt, tem); | |
1574 | changed = true; | |
1575 | } | |
1576 | } | |
1577 | } | |
1578 | break; | |
1579 | ||
cbdd87d4 RG |
1580 | default:; |
1581 | } | |
1582 | ||
1583 | stmt = gsi_stmt (*gsi); | |
1584 | ||
1585 | /* Fold *& on the lhs. */ | |
1586 | if (gimple_has_lhs (stmt)) | |
1587 | { | |
1588 | tree lhs = gimple_get_lhs (stmt); | |
1589 | if (lhs && REFERENCE_CLASS_P (lhs)) | |
1590 | { | |
1591 | tree new_lhs = maybe_fold_reference (lhs, true); | |
1592 | if (new_lhs) | |
1593 | { | |
1594 | gimple_set_lhs (stmt, new_lhs); | |
1595 | changed = true; | |
1596 | } | |
1597 | } | |
1598 | } | |
1599 | ||
1600 | return changed; | |
1601 | } | |
1602 | ||
1603 | /* Fold the statement pointed to by GSI. In some cases, this function may | |
1604 | replace the whole statement with a new one. Returns true iff folding | |
1605 | makes any changes. | |
1606 | The statement pointed to by GSI should be in valid gimple form but may | |
1607 | be in unfolded state as resulting from for example constant propagation | |
1608 | which can produce *&x = 0. */ | |
1609 | ||
1610 | bool | |
1611 | fold_stmt (gimple_stmt_iterator *gsi) | |
1612 | { | |
1613 | return fold_stmt_1 (gsi, false); | |
1614 | } | |
1615 | ||
1616 | /* Perform the minimal folding on statement STMT. Only operations like | |
1617 | *&x created by constant propagation are handled. The statement cannot | |
1618 | be replaced with a new one. Return true if the statement was | |
1619 | changed, false otherwise. | |
1620 | The statement STMT should be in valid gimple form but may | |
1621 | be in unfolded state as resulting from for example constant propagation | |
1622 | which can produce *&x = 0. */ | |
1623 | ||
1624 | bool | |
1625 | fold_stmt_inplace (gimple stmt) | |
1626 | { | |
1627 | gimple_stmt_iterator gsi = gsi_for_stmt (stmt); | |
1628 | bool changed = fold_stmt_1 (&gsi, true); | |
1629 | gcc_assert (gsi_stmt (gsi) == stmt); | |
1630 | return changed; | |
1631 | } | |
1632 | ||
e89065a1 SL |
1633 | /* Canonicalize and possibly invert the boolean EXPR; return NULL_TREE |
1634 | if EXPR is null or we don't know how. | |
1635 | If non-null, the result always has boolean type. */ | |
1636 | ||
1637 | static tree | |
1638 | canonicalize_bool (tree expr, bool invert) | |
1639 | { | |
1640 | if (!expr) | |
1641 | return NULL_TREE; | |
1642 | else if (invert) | |
1643 | { | |
1644 | if (integer_nonzerop (expr)) | |
1645 | return boolean_false_node; | |
1646 | else if (integer_zerop (expr)) | |
1647 | return boolean_true_node; | |
1648 | else if (TREE_CODE (expr) == SSA_NAME) | |
1649 | return fold_build2 (EQ_EXPR, boolean_type_node, expr, | |
1650 | build_int_cst (TREE_TYPE (expr), 0)); | |
1651 | else if (TREE_CODE_CLASS (TREE_CODE (expr)) == tcc_comparison) | |
1652 | return fold_build2 (invert_tree_comparison (TREE_CODE (expr), false), | |
1653 | boolean_type_node, | |
1654 | TREE_OPERAND (expr, 0), | |
1655 | TREE_OPERAND (expr, 1)); | |
1656 | else | |
1657 | return NULL_TREE; | |
1658 | } | |
1659 | else | |
1660 | { | |
1661 | if (TREE_CODE (TREE_TYPE (expr)) == BOOLEAN_TYPE) | |
1662 | return expr; | |
1663 | if (integer_nonzerop (expr)) | |
1664 | return boolean_true_node; | |
1665 | else if (integer_zerop (expr)) | |
1666 | return boolean_false_node; | |
1667 | else if (TREE_CODE (expr) == SSA_NAME) | |
1668 | return fold_build2 (NE_EXPR, boolean_type_node, expr, | |
1669 | build_int_cst (TREE_TYPE (expr), 0)); | |
1670 | else if (TREE_CODE_CLASS (TREE_CODE (expr)) == tcc_comparison) | |
1671 | return fold_build2 (TREE_CODE (expr), | |
1672 | boolean_type_node, | |
1673 | TREE_OPERAND (expr, 0), | |
1674 | TREE_OPERAND (expr, 1)); | |
1675 | else | |
1676 | return NULL_TREE; | |
1677 | } | |
1678 | } | |
1679 | ||
1680 | /* Check to see if a boolean expression EXPR is logically equivalent to the | |
1681 | comparison (OP1 CODE OP2). Check for various identities involving | |
1682 | SSA_NAMEs. */ | |
1683 | ||
1684 | static bool | |
1685 | same_bool_comparison_p (const_tree expr, enum tree_code code, | |
1686 | const_tree op1, const_tree op2) | |
1687 | { | |
1688 | gimple s; | |
1689 | ||
1690 | /* The obvious case. */ | |
1691 | if (TREE_CODE (expr) == code | |
1692 | && operand_equal_p (TREE_OPERAND (expr, 0), op1, 0) | |
1693 | && operand_equal_p (TREE_OPERAND (expr, 1), op2, 0)) | |
1694 | return true; | |
1695 | ||
1696 | /* Check for comparing (name, name != 0) and the case where expr | |
1697 | is an SSA_NAME with a definition matching the comparison. */ | |
1698 | if (TREE_CODE (expr) == SSA_NAME | |
1699 | && TREE_CODE (TREE_TYPE (expr)) == BOOLEAN_TYPE) | |
1700 | { | |
1701 | if (operand_equal_p (expr, op1, 0)) | |
1702 | return ((code == NE_EXPR && integer_zerop (op2)) | |
1703 | || (code == EQ_EXPR && integer_nonzerop (op2))); | |
1704 | s = SSA_NAME_DEF_STMT (expr); | |
1705 | if (is_gimple_assign (s) | |
1706 | && gimple_assign_rhs_code (s) == code | |
1707 | && operand_equal_p (gimple_assign_rhs1 (s), op1, 0) | |
1708 | && operand_equal_p (gimple_assign_rhs2 (s), op2, 0)) | |
1709 | return true; | |
1710 | } | |
1711 | ||
1712 | /* If op1 is of the form (name != 0) or (name == 0), and the definition | |
1713 | of name is a comparison, recurse. */ | |
1714 | if (TREE_CODE (op1) == SSA_NAME | |
1715 | && TREE_CODE (TREE_TYPE (op1)) == BOOLEAN_TYPE) | |
1716 | { | |
1717 | s = SSA_NAME_DEF_STMT (op1); | |
1718 | if (is_gimple_assign (s) | |
1719 | && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison) | |
1720 | { | |
1721 | enum tree_code c = gimple_assign_rhs_code (s); | |
1722 | if ((c == NE_EXPR && integer_zerop (op2)) | |
1723 | || (c == EQ_EXPR && integer_nonzerop (op2))) | |
1724 | return same_bool_comparison_p (expr, c, | |
1725 | gimple_assign_rhs1 (s), | |
1726 | gimple_assign_rhs2 (s)); | |
1727 | if ((c == EQ_EXPR && integer_zerop (op2)) | |
1728 | || (c == NE_EXPR && integer_nonzerop (op2))) | |
1729 | return same_bool_comparison_p (expr, | |
1730 | invert_tree_comparison (c, false), | |
1731 | gimple_assign_rhs1 (s), | |
1732 | gimple_assign_rhs2 (s)); | |
1733 | } | |
1734 | } | |
1735 | return false; | |
1736 | } | |
1737 | ||
1738 | /* Check to see if two boolean expressions OP1 and OP2 are logically | |
1739 | equivalent. */ | |
1740 | ||
1741 | static bool | |
1742 | same_bool_result_p (const_tree op1, const_tree op2) | |
1743 | { | |
1744 | /* Simple cases first. */ | |
1745 | if (operand_equal_p (op1, op2, 0)) | |
1746 | return true; | |
1747 | ||
1748 | /* Check the cases where at least one of the operands is a comparison. | |
1749 | These are a bit smarter than operand_equal_p in that they apply some | |
1750 | identifies on SSA_NAMEs. */ | |
1751 | if (TREE_CODE_CLASS (TREE_CODE (op2)) == tcc_comparison | |
1752 | && same_bool_comparison_p (op1, TREE_CODE (op2), | |
1753 | TREE_OPERAND (op2, 0), | |
1754 | TREE_OPERAND (op2, 1))) | |
1755 | return true; | |
1756 | if (TREE_CODE_CLASS (TREE_CODE (op1)) == tcc_comparison | |
1757 | && same_bool_comparison_p (op2, TREE_CODE (op1), | |
1758 | TREE_OPERAND (op1, 0), | |
1759 | TREE_OPERAND (op1, 1))) | |
1760 | return true; | |
1761 | ||
1762 | /* Default case. */ | |
1763 | return false; | |
1764 | } | |
1765 | ||
1766 | /* Forward declarations for some mutually recursive functions. */ | |
1767 | ||
1768 | static tree | |
1769 | and_comparisons_1 (enum tree_code code1, tree op1a, tree op1b, | |
1770 | enum tree_code code2, tree op2a, tree op2b); | |
1771 | static tree | |
1772 | and_var_with_comparison (tree var, bool invert, | |
1773 | enum tree_code code2, tree op2a, tree op2b); | |
1774 | static tree | |
1775 | and_var_with_comparison_1 (gimple stmt, | |
1776 | enum tree_code code2, tree op2a, tree op2b); | |
1777 | static tree | |
1778 | or_comparisons_1 (enum tree_code code1, tree op1a, tree op1b, | |
1779 | enum tree_code code2, tree op2a, tree op2b); | |
1780 | static tree | |
1781 | or_var_with_comparison (tree var, bool invert, | |
1782 | enum tree_code code2, tree op2a, tree op2b); | |
1783 | static tree | |
1784 | or_var_with_comparison_1 (gimple stmt, | |
1785 | enum tree_code code2, tree op2a, tree op2b); | |
1786 | ||
1787 | /* Helper function for and_comparisons_1: try to simplify the AND of the | |
1788 | ssa variable VAR with the comparison specified by (OP2A CODE2 OP2B). | |
1789 | If INVERT is true, invert the value of the VAR before doing the AND. | |
1790 | Return NULL_EXPR if we can't simplify this to a single expression. */ | |
1791 | ||
1792 | static tree | |
1793 | and_var_with_comparison (tree var, bool invert, | |
1794 | enum tree_code code2, tree op2a, tree op2b) | |
1795 | { | |
1796 | tree t; | |
1797 | gimple stmt = SSA_NAME_DEF_STMT (var); | |
1798 | ||
1799 | /* We can only deal with variables whose definitions are assignments. */ | |
1800 | if (!is_gimple_assign (stmt)) | |
1801 | return NULL_TREE; | |
1802 | ||
1803 | /* If we have an inverted comparison, apply DeMorgan's law and rewrite | |
1804 | !var AND (op2a code2 op2b) => !(var OR !(op2a code2 op2b)) | |
1805 | Then we only have to consider the simpler non-inverted cases. */ | |
1806 | if (invert) | |
1807 | t = or_var_with_comparison_1 (stmt, | |
1808 | invert_tree_comparison (code2, false), | |
1809 | op2a, op2b); | |
1810 | else | |
1811 | t = and_var_with_comparison_1 (stmt, code2, op2a, op2b); | |
1812 | return canonicalize_bool (t, invert); | |
1813 | } | |
1814 | ||
1815 | /* Try to simplify the AND of the ssa variable defined by the assignment | |
1816 | STMT with the comparison specified by (OP2A CODE2 OP2B). | |
1817 | Return NULL_EXPR if we can't simplify this to a single expression. */ | |
1818 | ||
1819 | static tree | |
1820 | and_var_with_comparison_1 (gimple stmt, | |
1821 | enum tree_code code2, tree op2a, tree op2b) | |
1822 | { | |
1823 | tree var = gimple_assign_lhs (stmt); | |
1824 | tree true_test_var = NULL_TREE; | |
1825 | tree false_test_var = NULL_TREE; | |
1826 | enum tree_code innercode = gimple_assign_rhs_code (stmt); | |
1827 | ||
1828 | /* Check for identities like (var AND (var == 0)) => false. */ | |
1829 | if (TREE_CODE (op2a) == SSA_NAME | |
1830 | && TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE) | |
1831 | { | |
1832 | if ((code2 == NE_EXPR && integer_zerop (op2b)) | |
1833 | || (code2 == EQ_EXPR && integer_nonzerop (op2b))) | |
1834 | { | |
1835 | true_test_var = op2a; | |
1836 | if (var == true_test_var) | |
1837 | return var; | |
1838 | } | |
1839 | else if ((code2 == EQ_EXPR && integer_zerop (op2b)) | |
1840 | || (code2 == NE_EXPR && integer_nonzerop (op2b))) | |
1841 | { | |
1842 | false_test_var = op2a; | |
1843 | if (var == false_test_var) | |
1844 | return boolean_false_node; | |
1845 | } | |
1846 | } | |
1847 | ||
1848 | /* If the definition is a comparison, recurse on it. */ | |
1849 | if (TREE_CODE_CLASS (innercode) == tcc_comparison) | |
1850 | { | |
1851 | tree t = and_comparisons_1 (innercode, | |
1852 | gimple_assign_rhs1 (stmt), | |
1853 | gimple_assign_rhs2 (stmt), | |
1854 | code2, | |
1855 | op2a, | |
1856 | op2b); | |
1857 | if (t) | |
1858 | return t; | |
1859 | } | |
1860 | ||
1861 | /* If the definition is an AND or OR expression, we may be able to | |
1862 | simplify by reassociating. */ | |
1863 | if (innercode == TRUTH_AND_EXPR | |
1864 | || innercode == TRUTH_OR_EXPR | |
1865 | || (TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE | |
1866 | && (innercode == BIT_AND_EXPR || innercode == BIT_IOR_EXPR))) | |
1867 | { | |
1868 | tree inner1 = gimple_assign_rhs1 (stmt); | |
1869 | tree inner2 = gimple_assign_rhs2 (stmt); | |
1870 | gimple s; | |
1871 | tree t; | |
1872 | tree partial = NULL_TREE; | |
1873 | bool is_and = (innercode == TRUTH_AND_EXPR || innercode == BIT_AND_EXPR); | |
1874 | ||
1875 | /* Check for boolean identities that don't require recursive examination | |
1876 | of inner1/inner2: | |
1877 | inner1 AND (inner1 AND inner2) => inner1 AND inner2 => var | |
1878 | inner1 AND (inner1 OR inner2) => inner1 | |
1879 | !inner1 AND (inner1 AND inner2) => false | |
1880 | !inner1 AND (inner1 OR inner2) => !inner1 AND inner2 | |
1881 | Likewise for similar cases involving inner2. */ | |
1882 | if (inner1 == true_test_var) | |
1883 | return (is_and ? var : inner1); | |
1884 | else if (inner2 == true_test_var) | |
1885 | return (is_and ? var : inner2); | |
1886 | else if (inner1 == false_test_var) | |
1887 | return (is_and | |
1888 | ? boolean_false_node | |
1889 | : and_var_with_comparison (inner2, false, code2, op2a, op2b)); | |
1890 | else if (inner2 == false_test_var) | |
1891 | return (is_and | |
1892 | ? boolean_false_node | |
1893 | : and_var_with_comparison (inner1, false, code2, op2a, op2b)); | |
1894 | ||
1895 | /* Next, redistribute/reassociate the AND across the inner tests. | |
1896 | Compute the first partial result, (inner1 AND (op2a code op2b)) */ | |
1897 | if (TREE_CODE (inner1) == SSA_NAME | |
1898 | && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner1)) | |
1899 | && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison | |
1900 | && (t = maybe_fold_and_comparisons (gimple_assign_rhs_code (s), | |
1901 | gimple_assign_rhs1 (s), | |
1902 | gimple_assign_rhs2 (s), | |
1903 | code2, op2a, op2b))) | |
1904 | { | |
1905 | /* Handle the AND case, where we are reassociating: | |
1906 | (inner1 AND inner2) AND (op2a code2 op2b) | |
1907 | => (t AND inner2) | |
1908 | If the partial result t is a constant, we win. Otherwise | |
1909 | continue on to try reassociating with the other inner test. */ | |
1910 | if (is_and) | |
1911 | { | |
1912 | if (integer_onep (t)) | |
1913 | return inner2; | |
1914 | else if (integer_zerop (t)) | |
1915 | return boolean_false_node; | |
1916 | } | |
1917 | ||
1918 | /* Handle the OR case, where we are redistributing: | |
1919 | (inner1 OR inner2) AND (op2a code2 op2b) | |
1920 | => (t OR (inner2 AND (op2a code2 op2b))) */ | |
8236c8eb JJ |
1921 | else if (integer_onep (t)) |
1922 | return boolean_true_node; | |
1923 | ||
1924 | /* Save partial result for later. */ | |
1925 | partial = t; | |
e89065a1 SL |
1926 | } |
1927 | ||
1928 | /* Compute the second partial result, (inner2 AND (op2a code op2b)) */ | |
1929 | if (TREE_CODE (inner2) == SSA_NAME | |
1930 | && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner2)) | |
1931 | && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison | |
1932 | && (t = maybe_fold_and_comparisons (gimple_assign_rhs_code (s), | |
1933 | gimple_assign_rhs1 (s), | |
1934 | gimple_assign_rhs2 (s), | |
1935 | code2, op2a, op2b))) | |
1936 | { | |
1937 | /* Handle the AND case, where we are reassociating: | |
1938 | (inner1 AND inner2) AND (op2a code2 op2b) | |
1939 | => (inner1 AND t) */ | |
1940 | if (is_and) | |
1941 | { | |
1942 | if (integer_onep (t)) | |
1943 | return inner1; | |
1944 | else if (integer_zerop (t)) | |
1945 | return boolean_false_node; | |
8236c8eb JJ |
1946 | /* If both are the same, we can apply the identity |
1947 | (x AND x) == x. */ | |
1948 | else if (partial && same_bool_result_p (t, partial)) | |
1949 | return t; | |
e89065a1 SL |
1950 | } |
1951 | ||
1952 | /* Handle the OR case. where we are redistributing: | |
1953 | (inner1 OR inner2) AND (op2a code2 op2b) | |
1954 | => (t OR (inner1 AND (op2a code2 op2b))) | |
1955 | => (t OR partial) */ | |
1956 | else | |
1957 | { | |
1958 | if (integer_onep (t)) | |
1959 | return boolean_true_node; | |
1960 | else if (partial) | |
1961 | { | |
1962 | /* We already got a simplification for the other | |
1963 | operand to the redistributed OR expression. The | |
1964 | interesting case is when at least one is false. | |
1965 | Or, if both are the same, we can apply the identity | |
1966 | (x OR x) == x. */ | |
1967 | if (integer_zerop (partial)) | |
1968 | return t; | |
1969 | else if (integer_zerop (t)) | |
1970 | return partial; | |
1971 | else if (same_bool_result_p (t, partial)) | |
1972 | return t; | |
1973 | } | |
1974 | } | |
1975 | } | |
1976 | } | |
1977 | return NULL_TREE; | |
1978 | } | |
1979 | ||
1980 | /* Try to simplify the AND of two comparisons defined by | |
1981 | (OP1A CODE1 OP1B) and (OP2A CODE2 OP2B), respectively. | |
1982 | If this can be done without constructing an intermediate value, | |
1983 | return the resulting tree; otherwise NULL_TREE is returned. | |
1984 | This function is deliberately asymmetric as it recurses on SSA_DEFs | |
1985 | in the first comparison but not the second. */ | |
1986 | ||
1987 | static tree | |
1988 | and_comparisons_1 (enum tree_code code1, tree op1a, tree op1b, | |
1989 | enum tree_code code2, tree op2a, tree op2b) | |
1990 | { | |
1991 | /* First check for ((x CODE1 y) AND (x CODE2 y)). */ | |
1992 | if (operand_equal_p (op1a, op2a, 0) | |
1993 | && operand_equal_p (op1b, op2b, 0)) | |
1994 | { | |
1995 | tree t = combine_comparisons (UNKNOWN_LOCATION, | |
1996 | TRUTH_ANDIF_EXPR, code1, code2, | |
1997 | boolean_type_node, op1a, op1b); | |
1998 | if (t) | |
1999 | return t; | |
2000 | } | |
2001 | ||
2002 | /* Likewise the swapped case of the above. */ | |
2003 | if (operand_equal_p (op1a, op2b, 0) | |
2004 | && operand_equal_p (op1b, op2a, 0)) | |
2005 | { | |
2006 | tree t = combine_comparisons (UNKNOWN_LOCATION, | |
2007 | TRUTH_ANDIF_EXPR, code1, | |
2008 | swap_tree_comparison (code2), | |
2009 | boolean_type_node, op1a, op1b); | |
2010 | if (t) | |
2011 | return t; | |
2012 | } | |
2013 | ||
2014 | /* If both comparisons are of the same value against constants, we might | |
2015 | be able to merge them. */ | |
2016 | if (operand_equal_p (op1a, op2a, 0) | |
2017 | && TREE_CODE (op1b) == INTEGER_CST | |
2018 | && TREE_CODE (op2b) == INTEGER_CST) | |
2019 | { | |
2020 | int cmp = tree_int_cst_compare (op1b, op2b); | |
2021 | ||
2022 | /* If we have (op1a == op1b), we should either be able to | |
2023 | return that or FALSE, depending on whether the constant op1b | |
2024 | also satisfies the other comparison against op2b. */ | |
2025 | if (code1 == EQ_EXPR) | |
2026 | { | |
2027 | bool done = true; | |
2028 | bool val; | |
2029 | switch (code2) | |
2030 | { | |
2031 | case EQ_EXPR: val = (cmp == 0); break; | |
2032 | case NE_EXPR: val = (cmp != 0); break; | |
2033 | case LT_EXPR: val = (cmp < 0); break; | |
2034 | case GT_EXPR: val = (cmp > 0); break; | |
2035 | case LE_EXPR: val = (cmp <= 0); break; | |
2036 | case GE_EXPR: val = (cmp >= 0); break; | |
2037 | default: done = false; | |
2038 | } | |
2039 | if (done) | |
2040 | { | |
2041 | if (val) | |
2042 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2043 | else | |
2044 | return boolean_false_node; | |
2045 | } | |
2046 | } | |
2047 | /* Likewise if the second comparison is an == comparison. */ | |
2048 | else if (code2 == EQ_EXPR) | |
2049 | { | |
2050 | bool done = true; | |
2051 | bool val; | |
2052 | switch (code1) | |
2053 | { | |
2054 | case EQ_EXPR: val = (cmp == 0); break; | |
2055 | case NE_EXPR: val = (cmp != 0); break; | |
2056 | case LT_EXPR: val = (cmp > 0); break; | |
2057 | case GT_EXPR: val = (cmp < 0); break; | |
2058 | case LE_EXPR: val = (cmp >= 0); break; | |
2059 | case GE_EXPR: val = (cmp <= 0); break; | |
2060 | default: done = false; | |
2061 | } | |
2062 | if (done) | |
2063 | { | |
2064 | if (val) | |
2065 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2066 | else | |
2067 | return boolean_false_node; | |
2068 | } | |
2069 | } | |
2070 | ||
2071 | /* Same business with inequality tests. */ | |
2072 | else if (code1 == NE_EXPR) | |
2073 | { | |
2074 | bool val; | |
2075 | switch (code2) | |
2076 | { | |
2077 | case EQ_EXPR: val = (cmp != 0); break; | |
2078 | case NE_EXPR: val = (cmp == 0); break; | |
2079 | case LT_EXPR: val = (cmp >= 0); break; | |
2080 | case GT_EXPR: val = (cmp <= 0); break; | |
2081 | case LE_EXPR: val = (cmp > 0); break; | |
2082 | case GE_EXPR: val = (cmp < 0); break; | |
2083 | default: | |
2084 | val = false; | |
2085 | } | |
2086 | if (val) | |
2087 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2088 | } | |
2089 | else if (code2 == NE_EXPR) | |
2090 | { | |
2091 | bool val; | |
2092 | switch (code1) | |
2093 | { | |
2094 | case EQ_EXPR: val = (cmp == 0); break; | |
2095 | case NE_EXPR: val = (cmp != 0); break; | |
2096 | case LT_EXPR: val = (cmp <= 0); break; | |
2097 | case GT_EXPR: val = (cmp >= 0); break; | |
2098 | case LE_EXPR: val = (cmp < 0); break; | |
2099 | case GE_EXPR: val = (cmp > 0); break; | |
2100 | default: | |
2101 | val = false; | |
2102 | } | |
2103 | if (val) | |
2104 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2105 | } | |
2106 | ||
2107 | /* Chose the more restrictive of two < or <= comparisons. */ | |
2108 | else if ((code1 == LT_EXPR || code1 == LE_EXPR) | |
2109 | && (code2 == LT_EXPR || code2 == LE_EXPR)) | |
2110 | { | |
2111 | if ((cmp < 0) || (cmp == 0 && code1 == LT_EXPR)) | |
2112 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2113 | else | |
2114 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2115 | } | |
2116 | ||
2117 | /* Likewise chose the more restrictive of two > or >= comparisons. */ | |
2118 | else if ((code1 == GT_EXPR || code1 == GE_EXPR) | |
2119 | && (code2 == GT_EXPR || code2 == GE_EXPR)) | |
2120 | { | |
2121 | if ((cmp > 0) || (cmp == 0 && code1 == GT_EXPR)) | |
2122 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2123 | else | |
2124 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2125 | } | |
2126 | ||
2127 | /* Check for singleton ranges. */ | |
2128 | else if (cmp == 0 | |
2129 | && ((code1 == LE_EXPR && code2 == GE_EXPR) | |
2130 | || (code1 == GE_EXPR && code2 == LE_EXPR))) | |
2131 | return fold_build2 (EQ_EXPR, boolean_type_node, op1a, op2b); | |
2132 | ||
2133 | /* Check for disjoint ranges. */ | |
2134 | else if (cmp <= 0 | |
2135 | && (code1 == LT_EXPR || code1 == LE_EXPR) | |
2136 | && (code2 == GT_EXPR || code2 == GE_EXPR)) | |
2137 | return boolean_false_node; | |
2138 | else if (cmp >= 0 | |
2139 | && (code1 == GT_EXPR || code1 == GE_EXPR) | |
2140 | && (code2 == LT_EXPR || code2 == LE_EXPR)) | |
2141 | return boolean_false_node; | |
2142 | } | |
2143 | ||
2144 | /* Perhaps the first comparison is (NAME != 0) or (NAME == 1) where | |
2145 | NAME's definition is a truth value. See if there are any simplifications | |
2146 | that can be done against the NAME's definition. */ | |
2147 | if (TREE_CODE (op1a) == SSA_NAME | |
2148 | && (code1 == NE_EXPR || code1 == EQ_EXPR) | |
2149 | && (integer_zerop (op1b) || integer_onep (op1b))) | |
2150 | { | |
2151 | bool invert = ((code1 == EQ_EXPR && integer_zerop (op1b)) | |
2152 | || (code1 == NE_EXPR && integer_onep (op1b))); | |
2153 | gimple stmt = SSA_NAME_DEF_STMT (op1a); | |
2154 | switch (gimple_code (stmt)) | |
2155 | { | |
2156 | case GIMPLE_ASSIGN: | |
2157 | /* Try to simplify by copy-propagating the definition. */ | |
2158 | return and_var_with_comparison (op1a, invert, code2, op2a, op2b); | |
2159 | ||
2160 | case GIMPLE_PHI: | |
2161 | /* If every argument to the PHI produces the same result when | |
2162 | ANDed with the second comparison, we win. | |
2163 | Do not do this unless the type is bool since we need a bool | |
2164 | result here anyway. */ | |
2165 | if (TREE_CODE (TREE_TYPE (op1a)) == BOOLEAN_TYPE) | |
2166 | { | |
2167 | tree result = NULL_TREE; | |
2168 | unsigned i; | |
2169 | for (i = 0; i < gimple_phi_num_args (stmt); i++) | |
2170 | { | |
2171 | tree arg = gimple_phi_arg_def (stmt, i); | |
2172 | ||
2173 | /* If this PHI has itself as an argument, ignore it. | |
2174 | If all the other args produce the same result, | |
2175 | we're still OK. */ | |
2176 | if (arg == gimple_phi_result (stmt)) | |
2177 | continue; | |
2178 | else if (TREE_CODE (arg) == INTEGER_CST) | |
2179 | { | |
2180 | if (invert ? integer_nonzerop (arg) : integer_zerop (arg)) | |
2181 | { | |
2182 | if (!result) | |
2183 | result = boolean_false_node; | |
2184 | else if (!integer_zerop (result)) | |
2185 | return NULL_TREE; | |
2186 | } | |
2187 | else if (!result) | |
2188 | result = fold_build2 (code2, boolean_type_node, | |
2189 | op2a, op2b); | |
2190 | else if (!same_bool_comparison_p (result, | |
2191 | code2, op2a, op2b)) | |
2192 | return NULL_TREE; | |
2193 | } | |
2194 | else if (TREE_CODE (arg) == SSA_NAME) | |
2195 | { | |
2196 | tree temp = and_var_with_comparison (arg, invert, | |
2197 | code2, op2a, op2b); | |
2198 | if (!temp) | |
2199 | return NULL_TREE; | |
2200 | else if (!result) | |
2201 | result = temp; | |
2202 | else if (!same_bool_result_p (result, temp)) | |
2203 | return NULL_TREE; | |
2204 | } | |
2205 | else | |
2206 | return NULL_TREE; | |
2207 | } | |
2208 | return result; | |
2209 | } | |
2210 | ||
2211 | default: | |
2212 | break; | |
2213 | } | |
2214 | } | |
2215 | return NULL_TREE; | |
2216 | } | |
2217 | ||
2218 | /* Try to simplify the AND of two comparisons, specified by | |
2219 | (OP1A CODE1 OP1B) and (OP2B CODE2 OP2B), respectively. | |
2220 | If this can be simplified to a single expression (without requiring | |
2221 | introducing more SSA variables to hold intermediate values), | |
2222 | return the resulting tree. Otherwise return NULL_TREE. | |
2223 | If the result expression is non-null, it has boolean type. */ | |
2224 | ||
2225 | tree | |
2226 | maybe_fold_and_comparisons (enum tree_code code1, tree op1a, tree op1b, | |
2227 | enum tree_code code2, tree op2a, tree op2b) | |
2228 | { | |
2229 | tree t = and_comparisons_1 (code1, op1a, op1b, code2, op2a, op2b); | |
2230 | if (t) | |
2231 | return t; | |
2232 | else | |
2233 | return and_comparisons_1 (code2, op2a, op2b, code1, op1a, op1b); | |
2234 | } | |
2235 | ||
2236 | /* Helper function for or_comparisons_1: try to simplify the OR of the | |
2237 | ssa variable VAR with the comparison specified by (OP2A CODE2 OP2B). | |
2238 | If INVERT is true, invert the value of VAR before doing the OR. | |
2239 | Return NULL_EXPR if we can't simplify this to a single expression. */ | |
2240 | ||
2241 | static tree | |
2242 | or_var_with_comparison (tree var, bool invert, | |
2243 | enum tree_code code2, tree op2a, tree op2b) | |
2244 | { | |
2245 | tree t; | |
2246 | gimple stmt = SSA_NAME_DEF_STMT (var); | |
2247 | ||
2248 | /* We can only deal with variables whose definitions are assignments. */ | |
2249 | if (!is_gimple_assign (stmt)) | |
2250 | return NULL_TREE; | |
2251 | ||
2252 | /* If we have an inverted comparison, apply DeMorgan's law and rewrite | |
2253 | !var OR (op2a code2 op2b) => !(var AND !(op2a code2 op2b)) | |
2254 | Then we only have to consider the simpler non-inverted cases. */ | |
2255 | if (invert) | |
2256 | t = and_var_with_comparison_1 (stmt, | |
2257 | invert_tree_comparison (code2, false), | |
2258 | op2a, op2b); | |
2259 | else | |
2260 | t = or_var_with_comparison_1 (stmt, code2, op2a, op2b); | |
2261 | return canonicalize_bool (t, invert); | |
2262 | } | |
2263 | ||
2264 | /* Try to simplify the OR of the ssa variable defined by the assignment | |
2265 | STMT with the comparison specified by (OP2A CODE2 OP2B). | |
2266 | Return NULL_EXPR if we can't simplify this to a single expression. */ | |
2267 | ||
2268 | static tree | |
2269 | or_var_with_comparison_1 (gimple stmt, | |
2270 | enum tree_code code2, tree op2a, tree op2b) | |
2271 | { | |
2272 | tree var = gimple_assign_lhs (stmt); | |
2273 | tree true_test_var = NULL_TREE; | |
2274 | tree false_test_var = NULL_TREE; | |
2275 | enum tree_code innercode = gimple_assign_rhs_code (stmt); | |
2276 | ||
2277 | /* Check for identities like (var OR (var != 0)) => true . */ | |
2278 | if (TREE_CODE (op2a) == SSA_NAME | |
2279 | && TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE) | |
2280 | { | |
2281 | if ((code2 == NE_EXPR && integer_zerop (op2b)) | |
2282 | || (code2 == EQ_EXPR && integer_nonzerop (op2b))) | |
2283 | { | |
2284 | true_test_var = op2a; | |
2285 | if (var == true_test_var) | |
2286 | return var; | |
2287 | } | |
2288 | else if ((code2 == EQ_EXPR && integer_zerop (op2b)) | |
2289 | || (code2 == NE_EXPR && integer_nonzerop (op2b))) | |
2290 | { | |
2291 | false_test_var = op2a; | |
2292 | if (var == false_test_var) | |
2293 | return boolean_true_node; | |
2294 | } | |
2295 | } | |
2296 | ||
2297 | /* If the definition is a comparison, recurse on it. */ | |
2298 | if (TREE_CODE_CLASS (innercode) == tcc_comparison) | |
2299 | { | |
2300 | tree t = or_comparisons_1 (innercode, | |
2301 | gimple_assign_rhs1 (stmt), | |
2302 | gimple_assign_rhs2 (stmt), | |
2303 | code2, | |
2304 | op2a, | |
2305 | op2b); | |
2306 | if (t) | |
2307 | return t; | |
2308 | } | |
2309 | ||
2310 | /* If the definition is an AND or OR expression, we may be able to | |
2311 | simplify by reassociating. */ | |
2312 | if (innercode == TRUTH_AND_EXPR | |
2313 | || innercode == TRUTH_OR_EXPR | |
2314 | || (TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE | |
2315 | && (innercode == BIT_AND_EXPR || innercode == BIT_IOR_EXPR))) | |
2316 | { | |
2317 | tree inner1 = gimple_assign_rhs1 (stmt); | |
2318 | tree inner2 = gimple_assign_rhs2 (stmt); | |
2319 | gimple s; | |
2320 | tree t; | |
2321 | tree partial = NULL_TREE; | |
2322 | bool is_or = (innercode == TRUTH_OR_EXPR || innercode == BIT_IOR_EXPR); | |
2323 | ||
2324 | /* Check for boolean identities that don't require recursive examination | |
2325 | of inner1/inner2: | |
2326 | inner1 OR (inner1 OR inner2) => inner1 OR inner2 => var | |
2327 | inner1 OR (inner1 AND inner2) => inner1 | |
2328 | !inner1 OR (inner1 OR inner2) => true | |
2329 | !inner1 OR (inner1 AND inner2) => !inner1 OR inner2 | |
2330 | */ | |
2331 | if (inner1 == true_test_var) | |
2332 | return (is_or ? var : inner1); | |
2333 | else if (inner2 == true_test_var) | |
2334 | return (is_or ? var : inner2); | |
2335 | else if (inner1 == false_test_var) | |
2336 | return (is_or | |
2337 | ? boolean_true_node | |
2338 | : or_var_with_comparison (inner2, false, code2, op2a, op2b)); | |
2339 | else if (inner2 == false_test_var) | |
2340 | return (is_or | |
2341 | ? boolean_true_node | |
2342 | : or_var_with_comparison (inner1, false, code2, op2a, op2b)); | |
2343 | ||
2344 | /* Next, redistribute/reassociate the OR across the inner tests. | |
2345 | Compute the first partial result, (inner1 OR (op2a code op2b)) */ | |
2346 | if (TREE_CODE (inner1) == SSA_NAME | |
2347 | && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner1)) | |
2348 | && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison | |
2349 | && (t = maybe_fold_or_comparisons (gimple_assign_rhs_code (s), | |
2350 | gimple_assign_rhs1 (s), | |
2351 | gimple_assign_rhs2 (s), | |
2352 | code2, op2a, op2b))) | |
2353 | { | |
2354 | /* Handle the OR case, where we are reassociating: | |
2355 | (inner1 OR inner2) OR (op2a code2 op2b) | |
2356 | => (t OR inner2) | |
2357 | If the partial result t is a constant, we win. Otherwise | |
2358 | continue on to try reassociating with the other inner test. */ | |
8236c8eb | 2359 | if (is_or) |
e89065a1 SL |
2360 | { |
2361 | if (integer_onep (t)) | |
2362 | return boolean_true_node; | |
2363 | else if (integer_zerop (t)) | |
2364 | return inner2; | |
2365 | } | |
2366 | ||
2367 | /* Handle the AND case, where we are redistributing: | |
2368 | (inner1 AND inner2) OR (op2a code2 op2b) | |
2369 | => (t AND (inner2 OR (op2a code op2b))) */ | |
8236c8eb JJ |
2370 | else if (integer_zerop (t)) |
2371 | return boolean_false_node; | |
2372 | ||
2373 | /* Save partial result for later. */ | |
2374 | partial = t; | |
e89065a1 SL |
2375 | } |
2376 | ||
2377 | /* Compute the second partial result, (inner2 OR (op2a code op2b)) */ | |
2378 | if (TREE_CODE (inner2) == SSA_NAME | |
2379 | && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner2)) | |
2380 | && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison | |
2381 | && (t = maybe_fold_or_comparisons (gimple_assign_rhs_code (s), | |
2382 | gimple_assign_rhs1 (s), | |
2383 | gimple_assign_rhs2 (s), | |
2384 | code2, op2a, op2b))) | |
2385 | { | |
2386 | /* Handle the OR case, where we are reassociating: | |
2387 | (inner1 OR inner2) OR (op2a code2 op2b) | |
8236c8eb JJ |
2388 | => (inner1 OR t) |
2389 | => (t OR partial) */ | |
2390 | if (is_or) | |
e89065a1 SL |
2391 | { |
2392 | if (integer_zerop (t)) | |
2393 | return inner1; | |
2394 | else if (integer_onep (t)) | |
2395 | return boolean_true_node; | |
8236c8eb JJ |
2396 | /* If both are the same, we can apply the identity |
2397 | (x OR x) == x. */ | |
2398 | else if (partial && same_bool_result_p (t, partial)) | |
2399 | return t; | |
e89065a1 SL |
2400 | } |
2401 | ||
2402 | /* Handle the AND case, where we are redistributing: | |
2403 | (inner1 AND inner2) OR (op2a code2 op2b) | |
2404 | => (t AND (inner1 OR (op2a code2 op2b))) | |
2405 | => (t AND partial) */ | |
2406 | else | |
2407 | { | |
2408 | if (integer_zerop (t)) | |
2409 | return boolean_false_node; | |
2410 | else if (partial) | |
2411 | { | |
2412 | /* We already got a simplification for the other | |
2413 | operand to the redistributed AND expression. The | |
2414 | interesting case is when at least one is true. | |
2415 | Or, if both are the same, we can apply the identity | |
8236c8eb | 2416 | (x AND x) == x. */ |
e89065a1 SL |
2417 | if (integer_onep (partial)) |
2418 | return t; | |
2419 | else if (integer_onep (t)) | |
2420 | return partial; | |
2421 | else if (same_bool_result_p (t, partial)) | |
8236c8eb | 2422 | return t; |
e89065a1 SL |
2423 | } |
2424 | } | |
2425 | } | |
2426 | } | |
2427 | return NULL_TREE; | |
2428 | } | |
2429 | ||
2430 | /* Try to simplify the OR of two comparisons defined by | |
2431 | (OP1A CODE1 OP1B) and (OP2A CODE2 OP2B), respectively. | |
2432 | If this can be done without constructing an intermediate value, | |
2433 | return the resulting tree; otherwise NULL_TREE is returned. | |
2434 | This function is deliberately asymmetric as it recurses on SSA_DEFs | |
2435 | in the first comparison but not the second. */ | |
2436 | ||
2437 | static tree | |
2438 | or_comparisons_1 (enum tree_code code1, tree op1a, tree op1b, | |
2439 | enum tree_code code2, tree op2a, tree op2b) | |
2440 | { | |
2441 | /* First check for ((x CODE1 y) OR (x CODE2 y)). */ | |
2442 | if (operand_equal_p (op1a, op2a, 0) | |
2443 | && operand_equal_p (op1b, op2b, 0)) | |
2444 | { | |
2445 | tree t = combine_comparisons (UNKNOWN_LOCATION, | |
2446 | TRUTH_ORIF_EXPR, code1, code2, | |
2447 | boolean_type_node, op1a, op1b); | |
2448 | if (t) | |
2449 | return t; | |
2450 | } | |
2451 | ||
2452 | /* Likewise the swapped case of the above. */ | |
2453 | if (operand_equal_p (op1a, op2b, 0) | |
2454 | && operand_equal_p (op1b, op2a, 0)) | |
2455 | { | |
2456 | tree t = combine_comparisons (UNKNOWN_LOCATION, | |
2457 | TRUTH_ORIF_EXPR, code1, | |
2458 | swap_tree_comparison (code2), | |
2459 | boolean_type_node, op1a, op1b); | |
2460 | if (t) | |
2461 | return t; | |
2462 | } | |
2463 | ||
2464 | /* If both comparisons are of the same value against constants, we might | |
2465 | be able to merge them. */ | |
2466 | if (operand_equal_p (op1a, op2a, 0) | |
2467 | && TREE_CODE (op1b) == INTEGER_CST | |
2468 | && TREE_CODE (op2b) == INTEGER_CST) | |
2469 | { | |
2470 | int cmp = tree_int_cst_compare (op1b, op2b); | |
2471 | ||
2472 | /* If we have (op1a != op1b), we should either be able to | |
2473 | return that or TRUE, depending on whether the constant op1b | |
2474 | also satisfies the other comparison against op2b. */ | |
2475 | if (code1 == NE_EXPR) | |
2476 | { | |
2477 | bool done = true; | |
2478 | bool val; | |
2479 | switch (code2) | |
2480 | { | |
2481 | case EQ_EXPR: val = (cmp == 0); break; | |
2482 | case NE_EXPR: val = (cmp != 0); break; | |
2483 | case LT_EXPR: val = (cmp < 0); break; | |
2484 | case GT_EXPR: val = (cmp > 0); break; | |
2485 | case LE_EXPR: val = (cmp <= 0); break; | |
2486 | case GE_EXPR: val = (cmp >= 0); break; | |
2487 | default: done = false; | |
2488 | } | |
2489 | if (done) | |
2490 | { | |
2491 | if (val) | |
2492 | return boolean_true_node; | |
2493 | else | |
2494 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2495 | } | |
2496 | } | |
2497 | /* Likewise if the second comparison is a != comparison. */ | |
2498 | else if (code2 == NE_EXPR) | |
2499 | { | |
2500 | bool done = true; | |
2501 | bool val; | |
2502 | switch (code1) | |
2503 | { | |
2504 | case EQ_EXPR: val = (cmp == 0); break; | |
2505 | case NE_EXPR: val = (cmp != 0); break; | |
2506 | case LT_EXPR: val = (cmp > 0); break; | |
2507 | case GT_EXPR: val = (cmp < 0); break; | |
2508 | case LE_EXPR: val = (cmp >= 0); break; | |
2509 | case GE_EXPR: val = (cmp <= 0); break; | |
2510 | default: done = false; | |
2511 | } | |
2512 | if (done) | |
2513 | { | |
2514 | if (val) | |
2515 | return boolean_true_node; | |
2516 | else | |
2517 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2518 | } | |
2519 | } | |
2520 | ||
2521 | /* See if an equality test is redundant with the other comparison. */ | |
2522 | else if (code1 == EQ_EXPR) | |
2523 | { | |
2524 | bool val; | |
2525 | switch (code2) | |
2526 | { | |
2527 | case EQ_EXPR: val = (cmp == 0); break; | |
2528 | case NE_EXPR: val = (cmp != 0); break; | |
2529 | case LT_EXPR: val = (cmp < 0); break; | |
2530 | case GT_EXPR: val = (cmp > 0); break; | |
2531 | case LE_EXPR: val = (cmp <= 0); break; | |
2532 | case GE_EXPR: val = (cmp >= 0); break; | |
2533 | default: | |
2534 | val = false; | |
2535 | } | |
2536 | if (val) | |
2537 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2538 | } | |
2539 | else if (code2 == EQ_EXPR) | |
2540 | { | |
2541 | bool val; | |
2542 | switch (code1) | |
2543 | { | |
2544 | case EQ_EXPR: val = (cmp == 0); break; | |
2545 | case NE_EXPR: val = (cmp != 0); break; | |
2546 | case LT_EXPR: val = (cmp > 0); break; | |
2547 | case GT_EXPR: val = (cmp < 0); break; | |
2548 | case LE_EXPR: val = (cmp >= 0); break; | |
2549 | case GE_EXPR: val = (cmp <= 0); break; | |
2550 | default: | |
2551 | val = false; | |
2552 | } | |
2553 | if (val) | |
2554 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2555 | } | |
2556 | ||
2557 | /* Chose the less restrictive of two < or <= comparisons. */ | |
2558 | else if ((code1 == LT_EXPR || code1 == LE_EXPR) | |
2559 | && (code2 == LT_EXPR || code2 == LE_EXPR)) | |
2560 | { | |
2561 | if ((cmp < 0) || (cmp == 0 && code1 == LT_EXPR)) | |
2562 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2563 | else | |
2564 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2565 | } | |
2566 | ||
2567 | /* Likewise chose the less restrictive of two > or >= comparisons. */ | |
2568 | else if ((code1 == GT_EXPR || code1 == GE_EXPR) | |
2569 | && (code2 == GT_EXPR || code2 == GE_EXPR)) | |
2570 | { | |
2571 | if ((cmp > 0) || (cmp == 0 && code1 == GT_EXPR)) | |
2572 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2573 | else | |
2574 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2575 | } | |
2576 | ||
2577 | /* Check for singleton ranges. */ | |
2578 | else if (cmp == 0 | |
2579 | && ((code1 == LT_EXPR && code2 == GT_EXPR) | |
2580 | || (code1 == GT_EXPR && code2 == LT_EXPR))) | |
2581 | return fold_build2 (NE_EXPR, boolean_type_node, op1a, op2b); | |
2582 | ||
2583 | /* Check for less/greater pairs that don't restrict the range at all. */ | |
2584 | else if (cmp >= 0 | |
2585 | && (code1 == LT_EXPR || code1 == LE_EXPR) | |
2586 | && (code2 == GT_EXPR || code2 == GE_EXPR)) | |
2587 | return boolean_true_node; | |
2588 | else if (cmp <= 0 | |
2589 | && (code1 == GT_EXPR || code1 == GE_EXPR) | |
2590 | && (code2 == LT_EXPR || code2 == LE_EXPR)) | |
2591 | return boolean_true_node; | |
2592 | } | |
2593 | ||
2594 | /* Perhaps the first comparison is (NAME != 0) or (NAME == 1) where | |
2595 | NAME's definition is a truth value. See if there are any simplifications | |
2596 | that can be done against the NAME's definition. */ | |
2597 | if (TREE_CODE (op1a) == SSA_NAME | |
2598 | && (code1 == NE_EXPR || code1 == EQ_EXPR) | |
2599 | && (integer_zerop (op1b) || integer_onep (op1b))) | |
2600 | { | |
2601 | bool invert = ((code1 == EQ_EXPR && integer_zerop (op1b)) | |
2602 | || (code1 == NE_EXPR && integer_onep (op1b))); | |
2603 | gimple stmt = SSA_NAME_DEF_STMT (op1a); | |
2604 | switch (gimple_code (stmt)) | |
2605 | { | |
2606 | case GIMPLE_ASSIGN: | |
2607 | /* Try to simplify by copy-propagating the definition. */ | |
2608 | return or_var_with_comparison (op1a, invert, code2, op2a, op2b); | |
2609 | ||
2610 | case GIMPLE_PHI: | |
2611 | /* If every argument to the PHI produces the same result when | |
2612 | ORed with the second comparison, we win. | |
2613 | Do not do this unless the type is bool since we need a bool | |
2614 | result here anyway. */ | |
2615 | if (TREE_CODE (TREE_TYPE (op1a)) == BOOLEAN_TYPE) | |
2616 | { | |
2617 | tree result = NULL_TREE; | |
2618 | unsigned i; | |
2619 | for (i = 0; i < gimple_phi_num_args (stmt); i++) | |
2620 | { | |
2621 | tree arg = gimple_phi_arg_def (stmt, i); | |
2622 | ||
2623 | /* If this PHI has itself as an argument, ignore it. | |
2624 | If all the other args produce the same result, | |
2625 | we're still OK. */ | |
2626 | if (arg == gimple_phi_result (stmt)) | |
2627 | continue; | |
2628 | else if (TREE_CODE (arg) == INTEGER_CST) | |
2629 | { | |
2630 | if (invert ? integer_zerop (arg) : integer_nonzerop (arg)) | |
2631 | { | |
2632 | if (!result) | |
2633 | result = boolean_true_node; | |
2634 | else if (!integer_onep (result)) | |
2635 | return NULL_TREE; | |
2636 | } | |
2637 | else if (!result) | |
2638 | result = fold_build2 (code2, boolean_type_node, | |
2639 | op2a, op2b); | |
2640 | else if (!same_bool_comparison_p (result, | |
2641 | code2, op2a, op2b)) | |
2642 | return NULL_TREE; | |
2643 | } | |
2644 | else if (TREE_CODE (arg) == SSA_NAME) | |
2645 | { | |
2646 | tree temp = or_var_with_comparison (arg, invert, | |
2647 | code2, op2a, op2b); | |
2648 | if (!temp) | |
2649 | return NULL_TREE; | |
2650 | else if (!result) | |
2651 | result = temp; | |
2652 | else if (!same_bool_result_p (result, temp)) | |
2653 | return NULL_TREE; | |
2654 | } | |
2655 | else | |
2656 | return NULL_TREE; | |
2657 | } | |
2658 | return result; | |
2659 | } | |
2660 | ||
2661 | default: | |
2662 | break; | |
2663 | } | |
2664 | } | |
2665 | return NULL_TREE; | |
2666 | } | |
2667 | ||
2668 | /* Try to simplify the OR of two comparisons, specified by | |
2669 | (OP1A CODE1 OP1B) and (OP2B CODE2 OP2B), respectively. | |
2670 | If this can be simplified to a single expression (without requiring | |
2671 | introducing more SSA variables to hold intermediate values), | |
2672 | return the resulting tree. Otherwise return NULL_TREE. | |
2673 | If the result expression is non-null, it has boolean type. */ | |
2674 | ||
2675 | tree | |
2676 | maybe_fold_or_comparisons (enum tree_code code1, tree op1a, tree op1b, | |
2677 | enum tree_code code2, tree op2a, tree op2b) | |
2678 | { | |
2679 | tree t = or_comparisons_1 (code1, op1a, op1b, code2, op2a, op2b); | |
2680 | if (t) | |
2681 | return t; | |
2682 | else | |
2683 | return or_comparisons_1 (code2, op2a, op2b, code1, op1a, op1b); | |
2684 | } | |
cfef45c8 RG |
2685 | |
2686 | ||
2687 | /* Fold STMT to a constant using VALUEIZE to valueize SSA names. | |
2688 | ||
2689 | Either NULL_TREE, a simplified but non-constant or a constant | |
2690 | is returned. | |
2691 | ||
2692 | ??? This should go into a gimple-fold-inline.h file to be eventually | |
2693 | privatized with the single valueize function used in the various TUs | |
2694 | to avoid the indirect function call overhead. */ | |
2695 | ||
2696 | tree | |
2697 | gimple_fold_stmt_to_constant_1 (gimple stmt, tree (*valueize) (tree)) | |
2698 | { | |
2699 | location_t loc = gimple_location (stmt); | |
2700 | switch (gimple_code (stmt)) | |
2701 | { | |
2702 | case GIMPLE_ASSIGN: | |
2703 | { | |
2704 | enum tree_code subcode = gimple_assign_rhs_code (stmt); | |
2705 | ||
2706 | switch (get_gimple_rhs_class (subcode)) | |
2707 | { | |
2708 | case GIMPLE_SINGLE_RHS: | |
2709 | { | |
2710 | tree rhs = gimple_assign_rhs1 (stmt); | |
2711 | enum tree_code_class kind = TREE_CODE_CLASS (subcode); | |
2712 | ||
2713 | if (TREE_CODE (rhs) == SSA_NAME) | |
2714 | { | |
2715 | /* If the RHS is an SSA_NAME, return its known constant value, | |
2716 | if any. */ | |
2717 | return (*valueize) (rhs); | |
2718 | } | |
2719 | /* Handle propagating invariant addresses into address | |
2720 | operations. */ | |
2721 | else if (TREE_CODE (rhs) == ADDR_EXPR | |
2722 | && !is_gimple_min_invariant (rhs)) | |
2723 | { | |
2724 | HOST_WIDE_INT offset; | |
2725 | tree base; | |
2726 | base = get_addr_base_and_unit_offset_1 (TREE_OPERAND (rhs, 0), | |
2727 | &offset, | |
2728 | valueize); | |
2729 | if (base | |
2730 | && (CONSTANT_CLASS_P (base) | |
2731 | || decl_address_invariant_p (base))) | |
2732 | return build_invariant_address (TREE_TYPE (rhs), | |
2733 | base, offset); | |
2734 | } | |
2735 | else if (TREE_CODE (rhs) == CONSTRUCTOR | |
2736 | && TREE_CODE (TREE_TYPE (rhs)) == VECTOR_TYPE | |
2737 | && (CONSTRUCTOR_NELTS (rhs) | |
2738 | == TYPE_VECTOR_SUBPARTS (TREE_TYPE (rhs)))) | |
2739 | { | |
2740 | unsigned i; | |
2741 | tree val, list; | |
2742 | ||
2743 | list = NULL_TREE; | |
2744 | FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (rhs), i, val) | |
2745 | { | |
2746 | val = (*valueize) (val); | |
2747 | if (TREE_CODE (val) == INTEGER_CST | |
2748 | || TREE_CODE (val) == REAL_CST | |
2749 | || TREE_CODE (val) == FIXED_CST) | |
2750 | list = tree_cons (NULL_TREE, val, list); | |
2751 | else | |
2752 | return NULL_TREE; | |
2753 | } | |
2754 | ||
2755 | return build_vector (TREE_TYPE (rhs), nreverse (list)); | |
2756 | } | |
2757 | ||
2758 | if (kind == tcc_reference) | |
2759 | { | |
2760 | if ((TREE_CODE (rhs) == VIEW_CONVERT_EXPR | |
2761 | || TREE_CODE (rhs) == REALPART_EXPR | |
2762 | || TREE_CODE (rhs) == IMAGPART_EXPR) | |
2763 | && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME) | |
2764 | { | |
2765 | tree val = (*valueize) (TREE_OPERAND (rhs, 0)); | |
2766 | return fold_unary_loc (EXPR_LOCATION (rhs), | |
2767 | TREE_CODE (rhs), | |
2768 | TREE_TYPE (rhs), val); | |
2769 | } | |
2770 | else if (TREE_CODE (rhs) == BIT_FIELD_REF | |
2771 | && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME) | |
2772 | { | |
2773 | tree val = (*valueize) (TREE_OPERAND (rhs, 0)); | |
2774 | return fold_ternary_loc (EXPR_LOCATION (rhs), | |
2775 | TREE_CODE (rhs), | |
2776 | TREE_TYPE (rhs), val, | |
2777 | TREE_OPERAND (rhs, 1), | |
2778 | TREE_OPERAND (rhs, 2)); | |
2779 | } | |
2780 | else if (TREE_CODE (rhs) == MEM_REF | |
2781 | && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME) | |
2782 | { | |
2783 | tree val = (*valueize) (TREE_OPERAND (rhs, 0)); | |
2784 | if (TREE_CODE (val) == ADDR_EXPR | |
2785 | && is_gimple_min_invariant (val)) | |
2786 | { | |
2787 | tree tem = fold_build2 (MEM_REF, TREE_TYPE (rhs), | |
2788 | unshare_expr (val), | |
2789 | TREE_OPERAND (rhs, 1)); | |
2790 | if (tem) | |
2791 | rhs = tem; | |
2792 | } | |
2793 | } | |
2794 | return fold_const_aggregate_ref_1 (rhs, valueize); | |
2795 | } | |
2796 | else if (kind == tcc_declaration) | |
2797 | return get_symbol_constant_value (rhs); | |
2798 | return rhs; | |
2799 | } | |
2800 | ||
2801 | case GIMPLE_UNARY_RHS: | |
2802 | { | |
2803 | /* Handle unary operators that can appear in GIMPLE form. | |
2804 | Note that we know the single operand must be a constant, | |
2805 | so this should almost always return a simplified RHS. */ | |
2806 | tree lhs = gimple_assign_lhs (stmt); | |
2807 | tree op0 = (*valueize) (gimple_assign_rhs1 (stmt)); | |
2808 | ||
2809 | /* Conversions are useless for CCP purposes if they are | |
2810 | value-preserving. Thus the restrictions that | |
2811 | useless_type_conversion_p places for pointer type conversions | |
2812 | do not apply here. Substitution later will only substitute to | |
2813 | allowed places. */ | |
2814 | if (CONVERT_EXPR_CODE_P (subcode) | |
2815 | && POINTER_TYPE_P (TREE_TYPE (lhs)) | |
2816 | && POINTER_TYPE_P (TREE_TYPE (op0))) | |
2817 | { | |
2818 | tree tem; | |
2819 | /* Try to re-construct array references on-the-fly. */ | |
2820 | if (!useless_type_conversion_p (TREE_TYPE (lhs), | |
2821 | TREE_TYPE (op0)) | |
2822 | && ((tem = maybe_fold_offset_to_address | |
2823 | (loc, | |
2824 | op0, integer_zero_node, TREE_TYPE (lhs))) | |
2825 | != NULL_TREE)) | |
2826 | return tem; | |
2827 | return op0; | |
2828 | } | |
2829 | ||
2830 | return | |
2831 | fold_unary_ignore_overflow_loc (loc, subcode, | |
2832 | gimple_expr_type (stmt), op0); | |
2833 | } | |
2834 | ||
2835 | case GIMPLE_BINARY_RHS: | |
2836 | { | |
2837 | /* Handle binary operators that can appear in GIMPLE form. */ | |
2838 | tree op0 = (*valueize) (gimple_assign_rhs1 (stmt)); | |
2839 | tree op1 = (*valueize) (gimple_assign_rhs2 (stmt)); | |
2840 | ||
2841 | /* Translate &x + CST into an invariant form suitable for | |
2842 | further propagation. */ | |
2843 | if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR | |
2844 | && TREE_CODE (op0) == ADDR_EXPR | |
2845 | && TREE_CODE (op1) == INTEGER_CST) | |
2846 | { | |
2847 | tree off = fold_convert (ptr_type_node, op1); | |
2848 | return build_fold_addr_expr | |
2849 | (fold_build2 (MEM_REF, | |
2850 | TREE_TYPE (TREE_TYPE (op0)), | |
2851 | unshare_expr (op0), off)); | |
2852 | } | |
2853 | ||
2854 | return fold_binary_loc (loc, subcode, | |
2855 | gimple_expr_type (stmt), op0, op1); | |
2856 | } | |
2857 | ||
2858 | case GIMPLE_TERNARY_RHS: | |
2859 | { | |
2860 | /* Handle ternary operators that can appear in GIMPLE form. */ | |
2861 | tree op0 = (*valueize) (gimple_assign_rhs1 (stmt)); | |
2862 | tree op1 = (*valueize) (gimple_assign_rhs2 (stmt)); | |
2863 | tree op2 = (*valueize) (gimple_assign_rhs3 (stmt)); | |
2864 | ||
2865 | return fold_ternary_loc (loc, subcode, | |
2866 | gimple_expr_type (stmt), op0, op1, op2); | |
2867 | } | |
2868 | ||
2869 | default: | |
2870 | gcc_unreachable (); | |
2871 | } | |
2872 | } | |
2873 | ||
2874 | case GIMPLE_CALL: | |
2875 | { | |
2876 | tree fn = (*valueize) (gimple_call_fn (stmt)); | |
2877 | if (TREE_CODE (fn) == ADDR_EXPR | |
2878 | && TREE_CODE (TREE_OPERAND (fn, 0)) == FUNCTION_DECL | |
2879 | && DECL_BUILT_IN (TREE_OPERAND (fn, 0))) | |
2880 | { | |
2881 | tree *args = XALLOCAVEC (tree, gimple_call_num_args (stmt)); | |
2882 | tree call, retval; | |
2883 | unsigned i; | |
2884 | for (i = 0; i < gimple_call_num_args (stmt); ++i) | |
2885 | args[i] = (*valueize) (gimple_call_arg (stmt, i)); | |
2886 | call = build_call_array_loc (loc, | |
2887 | gimple_call_return_type (stmt), | |
2888 | fn, gimple_call_num_args (stmt), args); | |
2889 | retval = fold_call_expr (EXPR_LOCATION (call), call, false); | |
2890 | if (retval) | |
2891 | /* fold_call_expr wraps the result inside a NOP_EXPR. */ | |
2892 | STRIP_NOPS (retval); | |
2893 | return retval; | |
2894 | } | |
2895 | return NULL_TREE; | |
2896 | } | |
2897 | ||
2898 | default: | |
2899 | return NULL_TREE; | |
2900 | } | |
2901 | } | |
2902 | ||
2903 | /* Fold STMT to a constant using VALUEIZE to valueize SSA names. | |
2904 | Returns NULL_TREE if folding to a constant is not possible, otherwise | |
2905 | returns a constant according to is_gimple_min_invariant. */ | |
2906 | ||
2907 | tree | |
2908 | gimple_fold_stmt_to_constant (gimple stmt, tree (*valueize) (tree)) | |
2909 | { | |
2910 | tree res = gimple_fold_stmt_to_constant_1 (stmt, valueize); | |
2911 | if (res && is_gimple_min_invariant (res)) | |
2912 | return res; | |
2913 | return NULL_TREE; | |
2914 | } | |
2915 | ||
2916 | ||
2917 | /* The following set of functions are supposed to fold references using | |
2918 | their constant initializers. */ | |
2919 | ||
2920 | static tree fold_ctor_reference (tree type, tree ctor, | |
2921 | unsigned HOST_WIDE_INT offset, | |
2922 | unsigned HOST_WIDE_INT size); | |
2923 | ||
2924 | /* See if we can find constructor defining value of BASE. | |
2925 | When we know the consructor with constant offset (such as | |
2926 | base is array[40] and we do know constructor of array), then | |
2927 | BIT_OFFSET is adjusted accordingly. | |
2928 | ||
2929 | As a special case, return error_mark_node when constructor | |
2930 | is not explicitly available, but it is known to be zero | |
2931 | such as 'static const int a;'. */ | |
2932 | static tree | |
2933 | get_base_constructor (tree base, HOST_WIDE_INT *bit_offset, | |
2934 | tree (*valueize)(tree)) | |
2935 | { | |
2936 | HOST_WIDE_INT bit_offset2, size, max_size; | |
2937 | if (TREE_CODE (base) == MEM_REF) | |
2938 | { | |
2939 | if (!integer_zerop (TREE_OPERAND (base, 1))) | |
2940 | { | |
2941 | if (!host_integerp (TREE_OPERAND (base, 1), 0)) | |
2942 | return NULL_TREE; | |
2943 | *bit_offset += (mem_ref_offset (base).low | |
2944 | * BITS_PER_UNIT); | |
2945 | } | |
2946 | ||
2947 | if (valueize | |
2948 | && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME) | |
2949 | base = valueize (TREE_OPERAND (base, 0)); | |
2950 | if (!base || TREE_CODE (base) != ADDR_EXPR) | |
2951 | return NULL_TREE; | |
2952 | base = TREE_OPERAND (base, 0); | |
2953 | } | |
2954 | ||
2955 | /* Get a CONSTRUCTOR. If BASE is a VAR_DECL, get its | |
2956 | DECL_INITIAL. If BASE is a nested reference into another | |
2957 | ARRAY_REF or COMPONENT_REF, make a recursive call to resolve | |
2958 | the inner reference. */ | |
2959 | switch (TREE_CODE (base)) | |
2960 | { | |
2961 | case VAR_DECL: | |
2962 | if (!const_value_known_p (base)) | |
2963 | return NULL_TREE; | |
2964 | ||
2965 | /* Fallthru. */ | |
2966 | case CONST_DECL: | |
2967 | if (!DECL_INITIAL (base) | |
2968 | && (TREE_STATIC (base) || DECL_EXTERNAL (base))) | |
2969 | return error_mark_node; | |
2970 | return DECL_INITIAL (base); | |
2971 | ||
2972 | case ARRAY_REF: | |
2973 | case COMPONENT_REF: | |
2974 | base = get_ref_base_and_extent (base, &bit_offset2, &size, &max_size); | |
2975 | if (max_size == -1 || size != max_size) | |
2976 | return NULL_TREE; | |
2977 | *bit_offset += bit_offset2; | |
2978 | return get_base_constructor (base, bit_offset, valueize); | |
2979 | ||
2980 | case STRING_CST: | |
2981 | case CONSTRUCTOR: | |
2982 | return base; | |
2983 | ||
2984 | default: | |
2985 | return NULL_TREE; | |
2986 | } | |
2987 | } | |
2988 | ||
2989 | /* CTOR is STRING_CST. Fold reference of type TYPE and size SIZE | |
2990 | to the memory at bit OFFSET. | |
2991 | ||
2992 | We do only simple job of folding byte accesses. */ | |
2993 | ||
2994 | static tree | |
2995 | fold_string_cst_ctor_reference (tree type, tree ctor, | |
2996 | unsigned HOST_WIDE_INT offset, | |
2997 | unsigned HOST_WIDE_INT size) | |
2998 | { | |
2999 | if (INTEGRAL_TYPE_P (type) | |
3000 | && (TYPE_MODE (type) | |
3001 | == TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) | |
3002 | && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) | |
3003 | == MODE_INT) | |
3004 | && GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) == 1 | |
3005 | && size == BITS_PER_UNIT | |
3006 | && !(offset % BITS_PER_UNIT)) | |
3007 | { | |
3008 | offset /= BITS_PER_UNIT; | |
3009 | if (offset < (unsigned HOST_WIDE_INT) TREE_STRING_LENGTH (ctor)) | |
3010 | return build_int_cst_type (type, (TREE_STRING_POINTER (ctor) | |
3011 | [offset])); | |
3012 | /* Folding | |
3013 | const char a[20]="hello"; | |
3014 | return a[10]; | |
3015 | ||
3016 | might lead to offset greater than string length. In this case we | |
3017 | know value is either initialized to 0 or out of bounds. Return 0 | |
3018 | in both cases. */ | |
3019 | return build_zero_cst (type); | |
3020 | } | |
3021 | return NULL_TREE; | |
3022 | } | |
3023 | ||
3024 | /* CTOR is CONSTRUCTOR of an array type. Fold reference of type TYPE and size | |
3025 | SIZE to the memory at bit OFFSET. */ | |
3026 | ||
3027 | static tree | |
3028 | fold_array_ctor_reference (tree type, tree ctor, | |
3029 | unsigned HOST_WIDE_INT offset, | |
3030 | unsigned HOST_WIDE_INT size) | |
3031 | { | |
3032 | unsigned HOST_WIDE_INT cnt; | |
3033 | tree cfield, cval; | |
3034 | double_int low_bound, elt_size; | |
3035 | double_int index, max_index; | |
3036 | double_int access_index; | |
3037 | tree domain_type = TYPE_DOMAIN (TREE_TYPE (ctor)); | |
3038 | HOST_WIDE_INT inner_offset; | |
3039 | ||
3040 | /* Compute low bound and elt size. */ | |
3041 | if (domain_type && TYPE_MIN_VALUE (domain_type)) | |
3042 | { | |
3043 | /* Static constructors for variably sized objects makes no sense. */ | |
3044 | gcc_assert (TREE_CODE (TYPE_MIN_VALUE (domain_type)) == INTEGER_CST); | |
3045 | low_bound = tree_to_double_int (TYPE_MIN_VALUE (domain_type)); | |
3046 | } | |
3047 | else | |
3048 | low_bound = double_int_zero; | |
3049 | /* Static constructors for variably sized objects makes no sense. */ | |
3050 | gcc_assert (TREE_CODE(TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (ctor)))) | |
3051 | == INTEGER_CST); | |
3052 | elt_size = | |
3053 | tree_to_double_int (TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (ctor)))); | |
3054 | ||
3055 | ||
3056 | /* We can handle only constantly sized accesses that are known to not | |
3057 | be larger than size of array element. */ | |
3058 | if (!TYPE_SIZE_UNIT (type) | |
3059 | || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST | |
3060 | || double_int_cmp (elt_size, | |
3061 | tree_to_double_int (TYPE_SIZE_UNIT (type)), 0) < 0) | |
3062 | return NULL_TREE; | |
3063 | ||
3064 | /* Compute the array index we look for. */ | |
3065 | access_index = double_int_udiv (uhwi_to_double_int (offset / BITS_PER_UNIT), | |
3066 | elt_size, TRUNC_DIV_EXPR); | |
3067 | access_index = double_int_add (access_index, low_bound); | |
3068 | ||
3069 | /* And offset within the access. */ | |
3070 | inner_offset = offset % (double_int_to_uhwi (elt_size) * BITS_PER_UNIT); | |
3071 | ||
3072 | /* See if the array field is large enough to span whole access. We do not | |
3073 | care to fold accesses spanning multiple array indexes. */ | |
3074 | if (inner_offset + size > double_int_to_uhwi (elt_size) * BITS_PER_UNIT) | |
3075 | return NULL_TREE; | |
3076 | ||
3077 | index = double_int_sub (low_bound, double_int_one); | |
3078 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, cval) | |
3079 | { | |
3080 | /* Array constructor might explicitely set index, or specify range | |
3081 | or leave index NULL meaning that it is next index after previous | |
3082 | one. */ | |
3083 | if (cfield) | |
3084 | { | |
3085 | if (TREE_CODE (cfield) == INTEGER_CST) | |
3086 | max_index = index = tree_to_double_int (cfield); | |
3087 | else | |
3088 | { | |
3089 | gcc_assert (TREE_CODE (cfield) == RANGE_EXPR); | |
3090 | index = tree_to_double_int (TREE_OPERAND (cfield, 0)); | |
3091 | max_index = tree_to_double_int (TREE_OPERAND (cfield, 1)); | |
3092 | } | |
3093 | } | |
3094 | else | |
3095 | max_index = index = double_int_add (index, double_int_one); | |
3096 | ||
3097 | /* Do we have match? */ | |
3098 | if (double_int_cmp (access_index, index, 1) >= 0 | |
3099 | && double_int_cmp (access_index, max_index, 1) <= 0) | |
3100 | return fold_ctor_reference (type, cval, inner_offset, size); | |
3101 | } | |
3102 | /* When memory is not explicitely mentioned in constructor, | |
3103 | it is 0 (or out of range). */ | |
3104 | return build_zero_cst (type); | |
3105 | } | |
3106 | ||
3107 | /* CTOR is CONSTRUCTOR of an aggregate or vector. | |
3108 | Fold reference of type TYPE and size SIZE to the memory at bit OFFSET. */ | |
3109 | ||
3110 | static tree | |
3111 | fold_nonarray_ctor_reference (tree type, tree ctor, | |
3112 | unsigned HOST_WIDE_INT offset, | |
3113 | unsigned HOST_WIDE_INT size) | |
3114 | { | |
3115 | unsigned HOST_WIDE_INT cnt; | |
3116 | tree cfield, cval; | |
3117 | ||
3118 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, | |
3119 | cval) | |
3120 | { | |
3121 | tree byte_offset = DECL_FIELD_OFFSET (cfield); | |
3122 | tree field_offset = DECL_FIELD_BIT_OFFSET (cfield); | |
3123 | tree field_size = DECL_SIZE (cfield); | |
3124 | double_int bitoffset; | |
3125 | double_int byte_offset_cst = tree_to_double_int (byte_offset); | |
3126 | double_int bits_per_unit_cst = uhwi_to_double_int (BITS_PER_UNIT); | |
3127 | double_int bitoffset_end; | |
3128 | ||
3129 | /* Variable sized objects in static constructors makes no sense, | |
3130 | but field_size can be NULL for flexible array members. */ | |
3131 | gcc_assert (TREE_CODE (field_offset) == INTEGER_CST | |
3132 | && TREE_CODE (byte_offset) == INTEGER_CST | |
3133 | && (field_size != NULL_TREE | |
3134 | ? TREE_CODE (field_size) == INTEGER_CST | |
3135 | : TREE_CODE (TREE_TYPE (cfield)) == ARRAY_TYPE)); | |
3136 | ||
3137 | /* Compute bit offset of the field. */ | |
3138 | bitoffset = double_int_add (tree_to_double_int (field_offset), | |
3139 | double_int_mul (byte_offset_cst, | |
3140 | bits_per_unit_cst)); | |
3141 | /* Compute bit offset where the field ends. */ | |
3142 | if (field_size != NULL_TREE) | |
3143 | bitoffset_end = double_int_add (bitoffset, | |
3144 | tree_to_double_int (field_size)); | |
3145 | else | |
3146 | bitoffset_end = double_int_zero; | |
3147 | ||
3148 | /* Is OFFSET in the range (BITOFFSET, BITOFFSET_END)? */ | |
3149 | if (double_int_cmp (uhwi_to_double_int (offset), bitoffset, 0) >= 0 | |
3150 | && (field_size == NULL_TREE | |
3151 | || double_int_cmp (uhwi_to_double_int (offset), | |
3152 | bitoffset_end, 0) < 0)) | |
3153 | { | |
3154 | double_int access_end = double_int_add (uhwi_to_double_int (offset), | |
3155 | uhwi_to_double_int (size)); | |
3156 | double_int inner_offset = double_int_sub (uhwi_to_double_int (offset), | |
3157 | bitoffset); | |
3158 | /* We do have overlap. Now see if field is large enough to | |
3159 | cover the access. Give up for accesses spanning multiple | |
3160 | fields. */ | |
3161 | if (double_int_cmp (access_end, bitoffset_end, 0) > 0) | |
3162 | return NULL_TREE; | |
3163 | return fold_ctor_reference (type, cval, | |
3164 | double_int_to_uhwi (inner_offset), size); | |
3165 | } | |
3166 | } | |
3167 | /* When memory is not explicitely mentioned in constructor, it is 0. */ | |
3168 | return build_zero_cst (type); | |
3169 | } | |
3170 | ||
3171 | /* CTOR is value initializing memory, fold reference of type TYPE and size SIZE | |
3172 | to the memory at bit OFFSET. */ | |
3173 | ||
3174 | static tree | |
3175 | fold_ctor_reference (tree type, tree ctor, unsigned HOST_WIDE_INT offset, | |
3176 | unsigned HOST_WIDE_INT size) | |
3177 | { | |
3178 | tree ret; | |
3179 | ||
3180 | /* We found the field with exact match. */ | |
3181 | if (useless_type_conversion_p (type, TREE_TYPE (ctor)) | |
3182 | && !offset) | |
3183 | return canonicalize_constructor_val (ctor); | |
3184 | ||
3185 | /* We are at the end of walk, see if we can view convert the | |
3186 | result. */ | |
3187 | if (!AGGREGATE_TYPE_P (TREE_TYPE (ctor)) && !offset | |
3188 | /* VIEW_CONVERT_EXPR is defined only for matching sizes. */ | |
3189 | && operand_equal_p (TYPE_SIZE (type), | |
3190 | TYPE_SIZE (TREE_TYPE (ctor)), 0)) | |
3191 | { | |
3192 | ret = canonicalize_constructor_val (ctor); | |
3193 | ret = fold_unary (VIEW_CONVERT_EXPR, type, ret); | |
3194 | if (ret) | |
3195 | STRIP_NOPS (ret); | |
3196 | return ret; | |
3197 | } | |
3198 | if (TREE_CODE (ctor) == STRING_CST) | |
3199 | return fold_string_cst_ctor_reference (type, ctor, offset, size); | |
3200 | if (TREE_CODE (ctor) == CONSTRUCTOR) | |
3201 | { | |
3202 | ||
3203 | if (TREE_CODE (TREE_TYPE (ctor)) == ARRAY_TYPE) | |
3204 | return fold_array_ctor_reference (type, ctor, offset, size); | |
3205 | else | |
3206 | return fold_nonarray_ctor_reference (type, ctor, offset, size); | |
3207 | } | |
3208 | ||
3209 | return NULL_TREE; | |
3210 | } | |
3211 | ||
3212 | /* Return the tree representing the element referenced by T if T is an | |
3213 | ARRAY_REF or COMPONENT_REF into constant aggregates valuezing SSA | |
3214 | names using VALUEIZE. Return NULL_TREE otherwise. */ | |
3215 | ||
3216 | tree | |
3217 | fold_const_aggregate_ref_1 (tree t, tree (*valueize) (tree)) | |
3218 | { | |
3219 | tree ctor, idx, base; | |
3220 | HOST_WIDE_INT offset, size, max_size; | |
3221 | tree tem; | |
3222 | ||
3223 | if (TREE_CODE_CLASS (TREE_CODE (t)) == tcc_declaration) | |
3224 | return get_symbol_constant_value (t); | |
3225 | ||
3226 | tem = fold_read_from_constant_string (t); | |
3227 | if (tem) | |
3228 | return tem; | |
3229 | ||
3230 | switch (TREE_CODE (t)) | |
3231 | { | |
3232 | case ARRAY_REF: | |
3233 | case ARRAY_RANGE_REF: | |
3234 | /* Constant indexes are handled well by get_base_constructor. | |
3235 | Only special case variable offsets. | |
3236 | FIXME: This code can't handle nested references with variable indexes | |
3237 | (they will be handled only by iteration of ccp). Perhaps we can bring | |
3238 | get_ref_base_and_extent here and make it use a valueize callback. */ | |
3239 | if (TREE_CODE (TREE_OPERAND (t, 1)) == SSA_NAME | |
3240 | && valueize | |
3241 | && (idx = (*valueize) (TREE_OPERAND (t, 1))) | |
3242 | && host_integerp (idx, 0)) | |
3243 | { | |
3244 | tree low_bound, unit_size; | |
3245 | ||
3246 | /* If the resulting bit-offset is constant, track it. */ | |
3247 | if ((low_bound = array_ref_low_bound (t), | |
3248 | host_integerp (low_bound, 0)) | |
3249 | && (unit_size = array_ref_element_size (t), | |
3250 | host_integerp (unit_size, 1))) | |
3251 | { | |
3252 | offset = TREE_INT_CST_LOW (idx); | |
3253 | offset -= TREE_INT_CST_LOW (low_bound); | |
3254 | offset *= TREE_INT_CST_LOW (unit_size); | |
3255 | offset *= BITS_PER_UNIT; | |
3256 | ||
3257 | base = TREE_OPERAND (t, 0); | |
3258 | ctor = get_base_constructor (base, &offset, valueize); | |
3259 | /* Empty constructor. Always fold to 0. */ | |
3260 | if (ctor == error_mark_node) | |
3261 | return build_zero_cst (TREE_TYPE (t)); | |
3262 | /* Out of bound array access. Value is undefined, | |
3263 | but don't fold. */ | |
3264 | if (offset < 0) | |
3265 | return NULL_TREE; | |
3266 | /* We can not determine ctor. */ | |
3267 | if (!ctor) | |
3268 | return NULL_TREE; | |
3269 | return fold_ctor_reference (TREE_TYPE (t), ctor, offset, | |
3270 | TREE_INT_CST_LOW (unit_size) | |
3271 | * BITS_PER_UNIT); | |
3272 | } | |
3273 | } | |
3274 | /* Fallthru. */ | |
3275 | ||
3276 | case COMPONENT_REF: | |
3277 | case BIT_FIELD_REF: | |
3278 | case TARGET_MEM_REF: | |
3279 | case MEM_REF: | |
3280 | base = get_ref_base_and_extent (t, &offset, &size, &max_size); | |
3281 | ctor = get_base_constructor (base, &offset, valueize); | |
3282 | ||
3283 | /* Empty constructor. Always fold to 0. */ | |
3284 | if (ctor == error_mark_node) | |
3285 | return build_zero_cst (TREE_TYPE (t)); | |
3286 | /* We do not know precise address. */ | |
3287 | if (max_size == -1 || max_size != size) | |
3288 | return NULL_TREE; | |
3289 | /* We can not determine ctor. */ | |
3290 | if (!ctor) | |
3291 | return NULL_TREE; | |
3292 | ||
3293 | /* Out of bound array access. Value is undefined, but don't fold. */ | |
3294 | if (offset < 0) | |
3295 | return NULL_TREE; | |
3296 | ||
3297 | return fold_ctor_reference (TREE_TYPE (t), ctor, offset, size); | |
3298 | ||
3299 | case REALPART_EXPR: | |
3300 | case IMAGPART_EXPR: | |
3301 | { | |
3302 | tree c = fold_const_aggregate_ref_1 (TREE_OPERAND (t, 0), valueize); | |
3303 | if (c && TREE_CODE (c) == COMPLEX_CST) | |
3304 | return fold_build1_loc (EXPR_LOCATION (t), | |
3305 | TREE_CODE (t), TREE_TYPE (t), c); | |
3306 | break; | |
3307 | } | |
3308 | ||
3309 | default: | |
3310 | break; | |
3311 | } | |
3312 | ||
3313 | return NULL_TREE; | |
3314 | } | |
3315 | ||
3316 | tree | |
3317 | fold_const_aggregate_ref (tree t) | |
3318 | { | |
3319 | return fold_const_aggregate_ref_1 (t, NULL); | |
3320 | } |