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2d18b16d | 1 | /* Statement simplification on GIMPLE. |
711789cc | 2 | Copyright (C) 2010-2013 Free Software Foundation, Inc. |
2d18b16d | 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" | |
2d18b16d | 27 | #include "function.h" |
b9ed1410 | 28 | #include "dumpfile.h" |
073c1fd5 | 29 | #include "bitmap.h" |
30 | #include "gimple.h" | |
31 | #include "gimple-ssa.h" | |
32 | #include "tree-ssanames.h" | |
33 | #include "tree-into-ssa.h" | |
34 | #include "tree-dfa.h" | |
69ee5dbb | 35 | #include "tree-ssa.h" |
2d18b16d | 36 | #include "tree-ssa-propagate.h" |
2d18b16d | 37 | #include "target.h" |
10fba9c0 | 38 | #include "ipa-utils.h" |
39 | #include "gimple-pretty-print.h" | |
424a4a92 | 40 | #include "tree-ssa-address.h" |
2d18b16d | 41 | |
551732eb | 42 | /* Return true when DECL can be referenced from current unit. |
a65b88bf | 43 | FROM_DECL (if non-null) specify constructor of variable DECL was taken from. |
44 | We can get declarations that are not possible to reference for various | |
45 | reasons: | |
f1c35659 | 46 | |
f1c35659 | 47 | 1) When analyzing C++ virtual tables. |
48 | C++ virtual tables do have known constructors even | |
49 | when they are keyed to other compilation unit. | |
50 | Those tables can contain pointers to methods and vars | |
51 | in other units. Those methods have both STATIC and EXTERNAL | |
52 | set. | |
53 | 2) In WHOPR mode devirtualization might lead to reference | |
54 | to method that was partitioned elsehwere. | |
55 | In this case we have static VAR_DECL or FUNCTION_DECL | |
56 | that has no corresponding callgraph/varpool node | |
551732eb | 57 | declaring the body. |
58 | 3) COMDAT functions referred by external vtables that | |
59 | we devirtualize only during final copmilation stage. | |
60 | At this time we already decided that we will not output | |
61 | the function body and thus we can't reference the symbol | |
62 | directly. */ | |
63 | ||
f1c35659 | 64 | static bool |
a65b88bf | 65 | can_refer_decl_in_current_unit_p (tree decl, tree from_decl) |
f1c35659 | 66 | { |
67 | struct varpool_node *vnode; | |
68 | struct cgraph_node *node; | |
a65b88bf | 69 | symtab_node snode; |
70 | ||
2246b6a9 | 71 | if (DECL_ABSTRACT (decl)) |
72 | return false; | |
73 | ||
74 | /* We are concerned only about static/external vars and functions. */ | |
75 | if ((!TREE_STATIC (decl) && !DECL_EXTERNAL (decl)) | |
76 | || (TREE_CODE (decl) != VAR_DECL && TREE_CODE (decl) != FUNCTION_DECL)) | |
77 | return true; | |
78 | ||
79 | /* Static objects can be referred only if they was not optimized out yet. */ | |
80 | if (!TREE_PUBLIC (decl) && !DECL_EXTERNAL (decl)) | |
81 | { | |
82 | snode = symtab_get_node (decl); | |
83 | if (!snode) | |
84 | return false; | |
85 | node = dyn_cast <cgraph_node> (snode); | |
86 | return !node || !node->global.inlined_to; | |
87 | } | |
88 | ||
8f1c7d19 | 89 | /* We will later output the initializer, so we can refer to it. |
a65b88bf | 90 | So we are concerned only when DECL comes from initializer of |
91 | external var. */ | |
92 | if (!from_decl | |
93 | || TREE_CODE (from_decl) != VAR_DECL | |
94 | || !DECL_EXTERNAL (from_decl) | |
8f1c7d19 | 95 | || (flag_ltrans |
02774f2d | 96 | && symtab_get_node (from_decl)->in_other_partition)) |
a65b88bf | 97 | return true; |
a65b88bf | 98 | /* We are folding reference from external vtable. The vtable may reffer |
99 | to a symbol keyed to other compilation unit. The other compilation | |
100 | unit may be in separate DSO and the symbol may be hidden. */ | |
101 | if (DECL_VISIBILITY_SPECIFIED (decl) | |
102 | && DECL_EXTERNAL (decl) | |
02774f2d | 103 | && (!(snode = symtab_get_node (decl)) || !snode->in_other_partition)) |
a65b88bf | 104 | return false; |
551732eb | 105 | /* When function is public, we always can introduce new reference. |
106 | Exception are the COMDAT functions where introducing a direct | |
107 | reference imply need to include function body in the curren tunit. */ | |
108 | if (TREE_PUBLIC (decl) && !DECL_COMDAT (decl)) | |
109 | return true; | |
110 | /* We are not at ltrans stage; so don't worry about WHOPR. | |
111 | Also when still gimplifying all referred comdat functions will be | |
9742b4a1 | 112 | produced. |
a65b88bf | 113 | |
114 | As observed in PR20991 for already optimized out comdat virtual functions | |
9d75589a | 115 | it may be tempting to not necessarily give up because the copy will be |
a65b88bf | 116 | output elsewhere when corresponding vtable is output. |
117 | This is however not possible - ABI specify that COMDATs are output in | |
118 | units where they are used and when the other unit was compiled with LTO | |
119 | it is possible that vtable was kept public while the function itself | |
120 | was privatized. */ | |
551732eb | 121 | if (!flag_ltrans && (!DECL_COMDAT (decl) || !cgraph_function_flags_ready)) |
122 | return true; | |
a65b88bf | 123 | |
124 | /* OK we are seeing either COMDAT or static variable. In this case we must | |
125 | check that the definition is still around so we can refer it. */ | |
f1c35659 | 126 | if (TREE_CODE (decl) == FUNCTION_DECL) |
127 | { | |
128 | node = cgraph_get_node (decl); | |
551732eb | 129 | /* Check that we still have function body and that we didn't took |
130 | the decision to eliminate offline copy of the function yet. | |
131 | The second is important when devirtualization happens during final | |
132 | compilation stage when making a new reference no longer makes callee | |
133 | to be compiled. */ | |
02774f2d | 134 | if (!node || !node->definition || node->global.inlined_to) |
a65b88bf | 135 | { |
136 | gcc_checking_assert (!TREE_ASM_WRITTEN (decl)); | |
137 | return false; | |
138 | } | |
f1c35659 | 139 | } |
140 | else if (TREE_CODE (decl) == VAR_DECL) | |
141 | { | |
142 | vnode = varpool_get_node (decl); | |
02774f2d | 143 | if (!vnode || !vnode->definition) |
a65b88bf | 144 | { |
145 | gcc_checking_assert (!TREE_ASM_WRITTEN (decl)); | |
146 | return false; | |
147 | } | |
f1c35659 | 148 | } |
551732eb | 149 | return true; |
f1c35659 | 150 | } |
151 | ||
bb903e9c | 152 | /* CVAL is value taken from DECL_INITIAL of variable. Try to transform it into |
a65b88bf | 153 | acceptable form for is_gimple_min_invariant. |
154 | FROM_DECL (if non-NULL) specify variable whose constructor contains CVAL. */ | |
15ba153a | 155 | |
156 | tree | |
a65b88bf | 157 | canonicalize_constructor_val (tree cval, tree from_decl) |
15ba153a | 158 | { |
cf649032 | 159 | tree orig_cval = cval; |
160 | STRIP_NOPS (cval); | |
704d7315 | 161 | if (TREE_CODE (cval) == POINTER_PLUS_EXPR |
162 | && TREE_CODE (TREE_OPERAND (cval, 1)) == INTEGER_CST) | |
15ba153a | 163 | { |
704d7315 | 164 | tree ptr = TREE_OPERAND (cval, 0); |
165 | if (is_gimple_min_invariant (ptr)) | |
166 | cval = build1_loc (EXPR_LOCATION (cval), | |
167 | ADDR_EXPR, TREE_TYPE (ptr), | |
168 | fold_build2 (MEM_REF, TREE_TYPE (TREE_TYPE (ptr)), | |
169 | ptr, | |
170 | fold_convert (ptr_type_node, | |
171 | TREE_OPERAND (cval, 1)))); | |
15ba153a | 172 | } |
173 | if (TREE_CODE (cval) == ADDR_EXPR) | |
174 | { | |
8edd00b2 | 175 | tree base = NULL_TREE; |
176 | if (TREE_CODE (TREE_OPERAND (cval, 0)) == COMPOUND_LITERAL_EXPR) | |
7843e4bc | 177 | { |
178 | base = COMPOUND_LITERAL_EXPR_DECL (TREE_OPERAND (cval, 0)); | |
179 | if (base) | |
180 | TREE_OPERAND (cval, 0) = base; | |
181 | } | |
8edd00b2 | 182 | else |
183 | base = get_base_address (TREE_OPERAND (cval, 0)); | |
e25d4891 | 184 | if (!base) |
185 | return NULL_TREE; | |
551732eb | 186 | |
e25d4891 | 187 | if ((TREE_CODE (base) == VAR_DECL |
188 | || TREE_CODE (base) == FUNCTION_DECL) | |
a65b88bf | 189 | && !can_refer_decl_in_current_unit_p (base, from_decl)) |
f1c35659 | 190 | return NULL_TREE; |
e25d4891 | 191 | if (TREE_CODE (base) == VAR_DECL) |
b03e5397 | 192 | TREE_ADDRESSABLE (base) = 1; |
e25d4891 | 193 | else if (TREE_CODE (base) == FUNCTION_DECL) |
194 | { | |
195 | /* Make sure we create a cgraph node for functions we'll reference. | |
196 | They can be non-existent if the reference comes from an entry | |
197 | of an external vtable for example. */ | |
0a2d5b65 | 198 | cgraph_get_create_real_symbol_node (base); |
e25d4891 | 199 | } |
bb903e9c | 200 | /* Fixup types in global initializers. */ |
0554476d | 201 | if (TREE_TYPE (TREE_TYPE (cval)) != TREE_TYPE (TREE_OPERAND (cval, 0))) |
202 | cval = build_fold_addr_expr (TREE_OPERAND (cval, 0)); | |
cf649032 | 203 | |
204 | if (!useless_type_conversion_p (TREE_TYPE (orig_cval), TREE_TYPE (cval))) | |
205 | cval = fold_convert (TREE_TYPE (orig_cval), cval); | |
206 | return cval; | |
15ba153a | 207 | } |
cf649032 | 208 | return orig_cval; |
15ba153a | 209 | } |
2d18b16d | 210 | |
211 | /* If SYM is a constant variable with known value, return the value. | |
212 | NULL_TREE is returned otherwise. */ | |
213 | ||
214 | tree | |
215 | get_symbol_constant_value (tree sym) | |
216 | { | |
df8d3e89 | 217 | tree val = ctor_for_folding (sym); |
218 | if (val != error_mark_node) | |
2d18b16d | 219 | { |
2d18b16d | 220 | if (val) |
221 | { | |
8f266cd9 | 222 | val = canonicalize_constructor_val (unshare_expr (val), sym); |
f1c35659 | 223 | if (val && is_gimple_min_invariant (val)) |
15ba153a | 224 | return val; |
f1c35659 | 225 | else |
226 | return NULL_TREE; | |
2d18b16d | 227 | } |
228 | /* Variables declared 'const' without an initializer | |
229 | have zero as the initializer if they may not be | |
230 | overridden at link or run time. */ | |
231 | if (!val | |
2d18b16d | 232 | && (INTEGRAL_TYPE_P (TREE_TYPE (sym)) |
233 | || SCALAR_FLOAT_TYPE_P (TREE_TYPE (sym)))) | |
385f3f36 | 234 | return build_zero_cst (TREE_TYPE (sym)); |
2d18b16d | 235 | } |
236 | ||
237 | return NULL_TREE; | |
238 | } | |
239 | ||
240 | ||
2d18b16d | 241 | |
242 | /* Subroutine of fold_stmt. We perform several simplifications of the | |
243 | memory reference tree EXPR and make sure to re-gimplify them properly | |
244 | after propagation of constant addresses. IS_LHS is true if the | |
245 | reference is supposed to be an lvalue. */ | |
246 | ||
247 | static tree | |
248 | maybe_fold_reference (tree expr, bool is_lhs) | |
249 | { | |
250 | tree *t = &expr; | |
15ba153a | 251 | tree result; |
2d18b16d | 252 | |
c701e5d5 | 253 | if ((TREE_CODE (expr) == VIEW_CONVERT_EXPR |
254 | || TREE_CODE (expr) == REALPART_EXPR | |
255 | || TREE_CODE (expr) == IMAGPART_EXPR) | |
256 | && CONSTANT_CLASS_P (TREE_OPERAND (expr, 0))) | |
257 | return fold_unary_loc (EXPR_LOCATION (expr), | |
258 | TREE_CODE (expr), | |
259 | TREE_TYPE (expr), | |
260 | TREE_OPERAND (expr, 0)); | |
261 | else if (TREE_CODE (expr) == BIT_FIELD_REF | |
262 | && CONSTANT_CLASS_P (TREE_OPERAND (expr, 0))) | |
263 | return fold_ternary_loc (EXPR_LOCATION (expr), | |
264 | TREE_CODE (expr), | |
265 | TREE_TYPE (expr), | |
266 | TREE_OPERAND (expr, 0), | |
267 | TREE_OPERAND (expr, 1), | |
268 | TREE_OPERAND (expr, 2)); | |
269 | ||
270 | while (handled_component_p (*t)) | |
271 | t = &TREE_OPERAND (*t, 0); | |
2d18b16d | 272 | |
c701e5d5 | 273 | /* Canonicalize MEM_REFs invariant address operand. Do this first |
274 | to avoid feeding non-canonical MEM_REFs elsewhere. */ | |
275 | if (TREE_CODE (*t) == MEM_REF | |
276 | && !is_gimple_mem_ref_addr (TREE_OPERAND (*t, 0))) | |
2d18b16d | 277 | { |
c701e5d5 | 278 | bool volatile_p = TREE_THIS_VOLATILE (*t); |
279 | tree tem = fold_binary (MEM_REF, TREE_TYPE (*t), | |
280 | TREE_OPERAND (*t, 0), | |
281 | TREE_OPERAND (*t, 1)); | |
282 | if (tem) | |
283 | { | |
284 | TREE_THIS_VOLATILE (tem) = volatile_p; | |
285 | *t = tem; | |
286 | tem = maybe_fold_reference (expr, is_lhs); | |
287 | if (tem) | |
288 | return tem; | |
289 | return expr; | |
290 | } | |
2d18b16d | 291 | } |
292 | ||
c701e5d5 | 293 | if (!is_lhs |
294 | && (result = fold_const_aggregate_ref (expr)) | |
295 | && is_gimple_min_invariant (result)) | |
296 | return result; | |
2d18b16d | 297 | |
182cf5a9 | 298 | /* Fold back MEM_REFs to reference trees. */ |
299 | if (TREE_CODE (*t) == MEM_REF | |
300 | && TREE_CODE (TREE_OPERAND (*t, 0)) == ADDR_EXPR | |
301 | && integer_zerop (TREE_OPERAND (*t, 1)) | |
302 | && (TREE_THIS_VOLATILE (*t) | |
303 | == TREE_THIS_VOLATILE (TREE_OPERAND (TREE_OPERAND (*t, 0), 0))) | |
304 | && !TYPE_REF_CAN_ALIAS_ALL (TREE_TYPE (TREE_OPERAND (*t, 1))) | |
305 | && (TYPE_MAIN_VARIANT (TREE_TYPE (*t)) | |
306 | == TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (TREE_OPERAND (*t, 1))))) | |
307 | /* We have to look out here to not drop a required conversion | |
308 | from the rhs to the lhs if is_lhs, but we don't have the | |
309 | rhs here to verify that. Thus require strict type | |
310 | compatibility. */ | |
311 | && types_compatible_p (TREE_TYPE (*t), | |
312 | TREE_TYPE (TREE_OPERAND | |
c701e5d5 | 313 | (TREE_OPERAND (*t, 0), 0)))) |
2d18b16d | 314 | { |
182cf5a9 | 315 | tree tem; |
316 | *t = TREE_OPERAND (TREE_OPERAND (*t, 0), 0); | |
317 | tem = maybe_fold_reference (expr, is_lhs); | |
318 | if (tem) | |
319 | return tem; | |
320 | return expr; | |
321 | } | |
28daba6f | 322 | else if (TREE_CODE (*t) == TARGET_MEM_REF) |
323 | { | |
324 | tree tem = maybe_fold_tmr (*t); | |
325 | if (tem) | |
326 | { | |
327 | *t = tem; | |
328 | tem = maybe_fold_reference (expr, is_lhs); | |
329 | if (tem) | |
330 | return tem; | |
331 | return expr; | |
332 | } | |
333 | } | |
2d18b16d | 334 | |
335 | return NULL_TREE; | |
336 | } | |
337 | ||
338 | ||
339 | /* Attempt to fold an assignment statement pointed-to by SI. Returns a | |
340 | replacement rhs for the statement or NULL_TREE if no simplification | |
341 | could be made. It is assumed that the operands have been previously | |
342 | folded. */ | |
343 | ||
344 | static tree | |
345 | fold_gimple_assign (gimple_stmt_iterator *si) | |
346 | { | |
347 | gimple stmt = gsi_stmt (*si); | |
348 | enum tree_code subcode = gimple_assign_rhs_code (stmt); | |
349 | location_t loc = gimple_location (stmt); | |
350 | ||
351 | tree result = NULL_TREE; | |
352 | ||
353 | switch (get_gimple_rhs_class (subcode)) | |
354 | { | |
355 | case GIMPLE_SINGLE_RHS: | |
356 | { | |
357 | tree rhs = gimple_assign_rhs1 (stmt); | |
358 | ||
8a2caf10 | 359 | if (REFERENCE_CLASS_P (rhs)) |
2d18b16d | 360 | return maybe_fold_reference (rhs, false); |
361 | ||
362 | else if (TREE_CODE (rhs) == ADDR_EXPR) | |
363 | { | |
182cf5a9 | 364 | tree ref = TREE_OPERAND (rhs, 0); |
365 | tree tem = maybe_fold_reference (ref, true); | |
366 | if (tem | |
367 | && TREE_CODE (tem) == MEM_REF | |
368 | && integer_zerop (TREE_OPERAND (tem, 1))) | |
369 | result = fold_convert (TREE_TYPE (rhs), TREE_OPERAND (tem, 0)); | |
370 | else if (tem) | |
2d18b16d | 371 | result = fold_convert (TREE_TYPE (rhs), |
372 | build_fold_addr_expr_loc (loc, tem)); | |
182cf5a9 | 373 | else if (TREE_CODE (ref) == MEM_REF |
374 | && integer_zerop (TREE_OPERAND (ref, 1))) | |
375 | result = fold_convert (TREE_TYPE (rhs), TREE_OPERAND (ref, 0)); | |
2d18b16d | 376 | } |
377 | ||
378 | else if (TREE_CODE (rhs) == CONSTRUCTOR | |
379 | && TREE_CODE (TREE_TYPE (rhs)) == VECTOR_TYPE | |
380 | && (CONSTRUCTOR_NELTS (rhs) | |
381 | == TYPE_VECTOR_SUBPARTS (TREE_TYPE (rhs)))) | |
382 | { | |
383 | /* Fold a constant vector CONSTRUCTOR to VECTOR_CST. */ | |
384 | unsigned i; | |
385 | tree val; | |
386 | ||
387 | FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (rhs), i, val) | |
388 | if (TREE_CODE (val) != INTEGER_CST | |
389 | && TREE_CODE (val) != REAL_CST | |
390 | && TREE_CODE (val) != FIXED_CST) | |
391 | return NULL_TREE; | |
392 | ||
393 | return build_vector_from_ctor (TREE_TYPE (rhs), | |
394 | CONSTRUCTOR_ELTS (rhs)); | |
395 | } | |
396 | ||
397 | else if (DECL_P (rhs)) | |
8f266cd9 | 398 | return get_symbol_constant_value (rhs); |
2d18b16d | 399 | |
400 | /* If we couldn't fold the RHS, hand over to the generic | |
401 | fold routines. */ | |
402 | if (result == NULL_TREE) | |
403 | result = fold (rhs); | |
404 | ||
405 | /* Strip away useless type conversions. Both the NON_LVALUE_EXPR | |
406 | that may have been added by fold, and "useless" type | |
407 | conversions that might now be apparent due to propagation. */ | |
408 | STRIP_USELESS_TYPE_CONVERSION (result); | |
409 | ||
410 | if (result != rhs && valid_gimple_rhs_p (result)) | |
411 | return result; | |
412 | ||
413 | return NULL_TREE; | |
414 | } | |
415 | break; | |
416 | ||
417 | case GIMPLE_UNARY_RHS: | |
418 | { | |
419 | tree rhs = gimple_assign_rhs1 (stmt); | |
420 | ||
421 | result = fold_unary_loc (loc, subcode, gimple_expr_type (stmt), rhs); | |
422 | if (result) | |
423 | { | |
424 | /* If the operation was a conversion do _not_ mark a | |
425 | resulting constant with TREE_OVERFLOW if the original | |
426 | constant was not. These conversions have implementation | |
427 | defined behavior and retaining the TREE_OVERFLOW flag | |
428 | here would confuse later passes such as VRP. */ | |
429 | if (CONVERT_EXPR_CODE_P (subcode) | |
430 | && TREE_CODE (result) == INTEGER_CST | |
431 | && TREE_CODE (rhs) == INTEGER_CST) | |
432 | TREE_OVERFLOW (result) = TREE_OVERFLOW (rhs); | |
433 | ||
434 | STRIP_USELESS_TYPE_CONVERSION (result); | |
435 | if (valid_gimple_rhs_p (result)) | |
436 | return result; | |
437 | } | |
2d18b16d | 438 | } |
439 | break; | |
440 | ||
441 | case GIMPLE_BINARY_RHS: | |
75200312 | 442 | /* Try to canonicalize for boolean-typed X the comparisons |
443 | X == 0, X == 1, X != 0, and X != 1. */ | |
704d7315 | 444 | if (gimple_assign_rhs_code (stmt) == EQ_EXPR |
445 | || gimple_assign_rhs_code (stmt) == NE_EXPR) | |
75200312 | 446 | { |
447 | tree lhs = gimple_assign_lhs (stmt); | |
448 | tree op1 = gimple_assign_rhs1 (stmt); | |
449 | tree op2 = gimple_assign_rhs2 (stmt); | |
450 | tree type = TREE_TYPE (op1); | |
451 | ||
452 | /* Check whether the comparison operands are of the same boolean | |
453 | type as the result type is. | |
454 | Check that second operand is an integer-constant with value | |
455 | one or zero. */ | |
456 | if (TREE_CODE (op2) == INTEGER_CST | |
457 | && (integer_zerop (op2) || integer_onep (op2)) | |
458 | && useless_type_conversion_p (TREE_TYPE (lhs), type)) | |
459 | { | |
460 | enum tree_code cmp_code = gimple_assign_rhs_code (stmt); | |
461 | bool is_logical_not = false; | |
462 | ||
463 | /* X == 0 and X != 1 is a logical-not.of X | |
464 | X == 1 and X != 0 is X */ | |
465 | if ((cmp_code == EQ_EXPR && integer_zerop (op2)) | |
466 | || (cmp_code == NE_EXPR && integer_onep (op2))) | |
467 | is_logical_not = true; | |
468 | ||
469 | if (is_logical_not == false) | |
470 | result = op1; | |
471 | /* Only for one-bit precision typed X the transformation | |
472 | !X -> ~X is valied. */ | |
473 | else if (TYPE_PRECISION (type) == 1) | |
474 | result = build1_loc (gimple_location (stmt), BIT_NOT_EXPR, | |
475 | type, op1); | |
476 | /* Otherwise we use !X -> X ^ 1. */ | |
477 | else | |
478 | result = build2_loc (gimple_location (stmt), BIT_XOR_EXPR, | |
479 | type, op1, build_int_cst (type, 1)); | |
480 | ||
481 | } | |
482 | } | |
2d18b16d | 483 | |
484 | if (!result) | |
485 | result = fold_binary_loc (loc, subcode, | |
fbd25d42 | 486 | TREE_TYPE (gimple_assign_lhs (stmt)), |
487 | gimple_assign_rhs1 (stmt), | |
488 | gimple_assign_rhs2 (stmt)); | |
2d18b16d | 489 | |
490 | if (result) | |
491 | { | |
492 | STRIP_USELESS_TYPE_CONVERSION (result); | |
493 | if (valid_gimple_rhs_p (result)) | |
494 | return result; | |
2d18b16d | 495 | } |
496 | break; | |
497 | ||
00f4f705 | 498 | case GIMPLE_TERNARY_RHS: |
8a2caf10 | 499 | /* Try to fold a conditional expression. */ |
500 | if (gimple_assign_rhs_code (stmt) == COND_EXPR) | |
501 | { | |
502 | tree op0 = gimple_assign_rhs1 (stmt); | |
503 | tree tem; | |
504 | bool set = false; | |
505 | location_t cond_loc = gimple_location (stmt); | |
506 | ||
507 | if (COMPARISON_CLASS_P (op0)) | |
508 | { | |
509 | fold_defer_overflow_warnings (); | |
510 | tem = fold_binary_loc (cond_loc, | |
511 | TREE_CODE (op0), TREE_TYPE (op0), | |
512 | TREE_OPERAND (op0, 0), | |
513 | TREE_OPERAND (op0, 1)); | |
514 | /* This is actually a conditional expression, not a GIMPLE | |
515 | conditional statement, however, the valid_gimple_rhs_p | |
516 | test still applies. */ | |
517 | set = (tem && is_gimple_condexpr (tem) | |
518 | && valid_gimple_rhs_p (tem)); | |
519 | fold_undefer_overflow_warnings (set, stmt, 0); | |
520 | } | |
521 | else if (is_gimple_min_invariant (op0)) | |
522 | { | |
523 | tem = op0; | |
524 | set = true; | |
525 | } | |
526 | else | |
527 | return NULL_TREE; | |
528 | ||
529 | if (set) | |
530 | result = fold_build3_loc (cond_loc, COND_EXPR, | |
531 | TREE_TYPE (gimple_assign_lhs (stmt)), tem, | |
532 | gimple_assign_rhs2 (stmt), | |
533 | gimple_assign_rhs3 (stmt)); | |
534 | } | |
535 | ||
536 | if (!result) | |
537 | result = fold_ternary_loc (loc, subcode, | |
538 | TREE_TYPE (gimple_assign_lhs (stmt)), | |
539 | gimple_assign_rhs1 (stmt), | |
540 | gimple_assign_rhs2 (stmt), | |
541 | gimple_assign_rhs3 (stmt)); | |
00f4f705 | 542 | |
543 | if (result) | |
544 | { | |
545 | STRIP_USELESS_TYPE_CONVERSION (result); | |
546 | if (valid_gimple_rhs_p (result)) | |
547 | return result; | |
00f4f705 | 548 | } |
549 | break; | |
550 | ||
2d18b16d | 551 | case GIMPLE_INVALID_RHS: |
552 | gcc_unreachable (); | |
553 | } | |
554 | ||
555 | return NULL_TREE; | |
556 | } | |
557 | ||
558 | /* Attempt to fold a conditional statement. Return true if any changes were | |
559 | made. We only attempt to fold the condition expression, and do not perform | |
560 | any transformation that would require alteration of the cfg. It is | |
561 | assumed that the operands have been previously folded. */ | |
562 | ||
563 | static bool | |
564 | fold_gimple_cond (gimple stmt) | |
565 | { | |
566 | tree result = fold_binary_loc (gimple_location (stmt), | |
567 | gimple_cond_code (stmt), | |
568 | boolean_type_node, | |
569 | gimple_cond_lhs (stmt), | |
570 | gimple_cond_rhs (stmt)); | |
571 | ||
572 | if (result) | |
573 | { | |
574 | STRIP_USELESS_TYPE_CONVERSION (result); | |
575 | if (is_gimple_condexpr (result) && valid_gimple_rhs_p (result)) | |
576 | { | |
577 | gimple_cond_set_condition_from_tree (stmt, result); | |
578 | return true; | |
579 | } | |
580 | } | |
581 | ||
582 | return false; | |
583 | } | |
584 | ||
585 | /* Convert EXPR into a GIMPLE value suitable for substitution on the | |
586 | RHS of an assignment. Insert the necessary statements before | |
587 | iterator *SI_P. The statement at *SI_P, which must be a GIMPLE_CALL | |
588 | is replaced. If the call is expected to produces a result, then it | |
589 | is replaced by an assignment of the new RHS to the result variable. | |
590 | If the result is to be ignored, then the call is replaced by a | |
3aadae2d | 591 | GIMPLE_NOP. A proper VDEF chain is retained by making the first |
592 | VUSE and the last VDEF of the whole sequence be the same as the replaced | |
593 | statement and using new SSA names for stores in between. */ | |
2d18b16d | 594 | |
595 | void | |
596 | gimplify_and_update_call_from_tree (gimple_stmt_iterator *si_p, tree expr) | |
597 | { | |
598 | tree lhs; | |
2d18b16d | 599 | gimple stmt, new_stmt; |
600 | gimple_stmt_iterator i; | |
e3a19533 | 601 | gimple_seq stmts = NULL; |
2d18b16d | 602 | struct gimplify_ctx gctx; |
34e73149 | 603 | gimple laststore; |
3aadae2d | 604 | tree reaching_vuse; |
2d18b16d | 605 | |
606 | stmt = gsi_stmt (*si_p); | |
607 | ||
608 | gcc_assert (is_gimple_call (stmt)); | |
609 | ||
2d18b16d | 610 | push_gimplify_context (&gctx); |
be7317e9 | 611 | gctx.into_ssa = gimple_in_ssa_p (cfun); |
2d18b16d | 612 | |
34e73149 | 613 | lhs = gimple_call_lhs (stmt); |
2d18b16d | 614 | if (lhs == NULL_TREE) |
a3087021 | 615 | { |
616 | gimplify_and_add (expr, &stmts); | |
617 | /* We can end up with folding a memcpy of an empty class assignment | |
618 | which gets optimized away by C++ gimplification. */ | |
619 | if (gimple_seq_empty_p (stmts)) | |
620 | { | |
ec4a428c | 621 | pop_gimplify_context (NULL); |
a3087021 | 622 | if (gimple_in_ssa_p (cfun)) |
623 | { | |
624 | unlink_stmt_vdef (stmt); | |
625 | release_defs (stmt); | |
626 | } | |
ce9bb3b3 | 627 | gsi_replace (si_p, gimple_build_nop (), true); |
a3087021 | 628 | return; |
629 | } | |
630 | } | |
2d18b16d | 631 | else |
34e73149 | 632 | { |
633 | tree tmp = get_initialized_tmp_var (expr, &stmts, NULL); | |
634 | new_stmt = gimple_build_assign (lhs, tmp); | |
635 | i = gsi_last (stmts); | |
636 | gsi_insert_after_without_update (&i, new_stmt, | |
637 | GSI_CONTINUE_LINKING); | |
638 | } | |
2d18b16d | 639 | |
640 | pop_gimplify_context (NULL); | |
641 | ||
642 | if (gimple_has_location (stmt)) | |
643 | annotate_all_with_location (stmts, gimple_location (stmt)); | |
644 | ||
34e73149 | 645 | /* First iterate over the replacement statements backward, assigning |
646 | virtual operands to their defining statements. */ | |
647 | laststore = NULL; | |
648 | for (i = gsi_last (stmts); !gsi_end_p (i); gsi_prev (&i)) | |
649 | { | |
650 | new_stmt = gsi_stmt (i); | |
e857485e | 651 | if ((gimple_assign_single_p (new_stmt) |
652 | && !is_gimple_reg (gimple_assign_lhs (new_stmt))) | |
653 | || (is_gimple_call (new_stmt) | |
654 | && (gimple_call_flags (new_stmt) | |
655 | & (ECF_NOVOPS | ECF_PURE | ECF_CONST | ECF_NORETURN)) == 0)) | |
34e73149 | 656 | { |
657 | tree vdef; | |
658 | if (!laststore) | |
659 | vdef = gimple_vdef (stmt); | |
660 | else | |
661 | vdef = make_ssa_name (gimple_vop (cfun), new_stmt); | |
662 | gimple_set_vdef (new_stmt, vdef); | |
4d7ebc36 | 663 | if (vdef && TREE_CODE (vdef) == SSA_NAME) |
34e73149 | 664 | SSA_NAME_DEF_STMT (vdef) = new_stmt; |
665 | laststore = new_stmt; | |
666 | } | |
667 | } | |
668 | ||
669 | /* Second iterate over the statements forward, assigning virtual | |
670 | operands to their uses. */ | |
34e73149 | 671 | reaching_vuse = gimple_vuse (stmt); |
2d18b16d | 672 | for (i = gsi_start (stmts); !gsi_end_p (i); gsi_next (&i)) |
673 | { | |
2d18b16d | 674 | new_stmt = gsi_stmt (i); |
03abbc5d | 675 | /* If the new statement possibly has a VUSE, update it with exact SSA |
676 | name we know will reach this one. */ | |
677 | if (gimple_has_mem_ops (new_stmt)) | |
34e73149 | 678 | gimple_set_vuse (new_stmt, reaching_vuse); |
679 | gimple_set_modified (new_stmt, true); | |
680 | if (gimple_vdef (new_stmt)) | |
681 | reaching_vuse = gimple_vdef (new_stmt); | |
2d18b16d | 682 | } |
683 | ||
34e73149 | 684 | /* If the new sequence does not do a store release the virtual |
685 | definition of the original statement. */ | |
686 | if (reaching_vuse | |
687 | && reaching_vuse == gimple_vuse (stmt)) | |
2d18b16d | 688 | { |
34e73149 | 689 | tree vdef = gimple_vdef (stmt); |
690 | if (vdef | |
691 | && TREE_CODE (vdef) == SSA_NAME) | |
3aadae2d | 692 | { |
693 | unlink_stmt_vdef (stmt); | |
34e73149 | 694 | release_ssa_name (vdef); |
78a0527a | 695 | } |
2d18b16d | 696 | } |
697 | ||
e3a19533 | 698 | /* Finally replace the original statement with the sequence. */ |
699 | gsi_replace_with_seq (si_p, stmts, false); | |
2d18b16d | 700 | } |
701 | ||
702 | /* Return the string length, maximum string length or maximum value of | |
703 | ARG in LENGTH. | |
704 | If ARG is an SSA name variable, follow its use-def chains. If LENGTH | |
705 | is not NULL and, for TYPE == 0, its value is not equal to the length | |
706 | we determine or if we are unable to determine the length or value, | |
707 | return false. VISITED is a bitmap of visited variables. | |
708 | TYPE is 0 if string length should be returned, 1 for maximum string | |
709 | length and 2 for maximum value ARG can have. */ | |
710 | ||
711 | static bool | |
712 | get_maxval_strlen (tree arg, tree *length, bitmap visited, int type) | |
713 | { | |
714 | tree var, val; | |
715 | gimple def_stmt; | |
716 | ||
717 | if (TREE_CODE (arg) != SSA_NAME) | |
718 | { | |
2d18b16d | 719 | /* We can end up with &(*iftmp_1)[0] here as well, so handle it. */ |
1eaedae6 | 720 | if (TREE_CODE (arg) == ADDR_EXPR |
721 | && TREE_CODE (TREE_OPERAND (arg, 0)) == ARRAY_REF | |
722 | && integer_zerop (TREE_OPERAND (TREE_OPERAND (arg, 0), 1))) | |
2d18b16d | 723 | { |
724 | tree aop0 = TREE_OPERAND (TREE_OPERAND (arg, 0), 0); | |
725 | if (TREE_CODE (aop0) == INDIRECT_REF | |
726 | && TREE_CODE (TREE_OPERAND (aop0, 0)) == SSA_NAME) | |
727 | return get_maxval_strlen (TREE_OPERAND (aop0, 0), | |
728 | length, visited, type); | |
729 | } | |
730 | ||
731 | if (type == 2) | |
732 | { | |
733 | val = arg; | |
734 | if (TREE_CODE (val) != INTEGER_CST | |
735 | || tree_int_cst_sgn (val) < 0) | |
736 | return false; | |
737 | } | |
738 | else | |
739 | val = c_strlen (arg, 1); | |
740 | if (!val) | |
741 | return false; | |
742 | ||
743 | if (*length) | |
744 | { | |
745 | if (type > 0) | |
746 | { | |
747 | if (TREE_CODE (*length) != INTEGER_CST | |
748 | || TREE_CODE (val) != INTEGER_CST) | |
749 | return false; | |
750 | ||
751 | if (tree_int_cst_lt (*length, val)) | |
752 | *length = val; | |
753 | return true; | |
754 | } | |
755 | else if (simple_cst_equal (val, *length) != 1) | |
756 | return false; | |
757 | } | |
758 | ||
759 | *length = val; | |
760 | return true; | |
761 | } | |
762 | ||
1a06b503 | 763 | /* If ARG is registered for SSA update we cannot look at its defining |
764 | statement. */ | |
765 | if (name_registered_for_update_p (arg)) | |
766 | return false; | |
767 | ||
2d18b16d | 768 | /* If we were already here, break the infinite cycle. */ |
6ef9bbe0 | 769 | if (!bitmap_set_bit (visited, SSA_NAME_VERSION (arg))) |
2d18b16d | 770 | return true; |
2d18b16d | 771 | |
772 | var = arg; | |
773 | def_stmt = SSA_NAME_DEF_STMT (var); | |
774 | ||
775 | switch (gimple_code (def_stmt)) | |
776 | { | |
777 | case GIMPLE_ASSIGN: | |
778 | /* The RHS of the statement defining VAR must either have a | |
779 | constant length or come from another SSA_NAME with a constant | |
780 | length. */ | |
781 | if (gimple_assign_single_p (def_stmt) | |
782 | || gimple_assign_unary_nop_p (def_stmt)) | |
783 | { | |
784 | tree rhs = gimple_assign_rhs1 (def_stmt); | |
785 | return get_maxval_strlen (rhs, length, visited, type); | |
786 | } | |
1eaedae6 | 787 | else if (gimple_assign_rhs_code (def_stmt) == COND_EXPR) |
788 | { | |
789 | tree op2 = gimple_assign_rhs2 (def_stmt); | |
790 | tree op3 = gimple_assign_rhs3 (def_stmt); | |
791 | return get_maxval_strlen (op2, length, visited, type) | |
792 | && get_maxval_strlen (op3, length, visited, type); | |
793 | } | |
2d18b16d | 794 | return false; |
795 | ||
796 | case GIMPLE_PHI: | |
797 | { | |
798 | /* All the arguments of the PHI node must have the same constant | |
799 | length. */ | |
800 | unsigned i; | |
801 | ||
802 | for (i = 0; i < gimple_phi_num_args (def_stmt); i++) | |
803 | { | |
804 | tree arg = gimple_phi_arg (def_stmt, i)->def; | |
805 | ||
806 | /* If this PHI has itself as an argument, we cannot | |
807 | determine the string length of this argument. However, | |
808 | if we can find a constant string length for the other | |
809 | PHI args then we can still be sure that this is a | |
810 | constant string length. So be optimistic and just | |
811 | continue with the next argument. */ | |
812 | if (arg == gimple_phi_result (def_stmt)) | |
813 | continue; | |
814 | ||
815 | if (!get_maxval_strlen (arg, length, visited, type)) | |
816 | return false; | |
817 | } | |
818 | } | |
819 | return true; | |
820 | ||
821 | default: | |
822 | return false; | |
823 | } | |
824 | } | |
825 | ||
826 | ||
827 | /* Fold builtin call in statement STMT. Returns a simplified tree. | |
828 | We may return a non-constant expression, including another call | |
829 | to a different function and with different arguments, e.g., | |
830 | substituting memcpy for strcpy when the string length is known. | |
831 | Note that some builtins expand into inline code that may not | |
832 | be valid in GIMPLE. Callers must take care. */ | |
833 | ||
834 | tree | |
835 | gimple_fold_builtin (gimple stmt) | |
836 | { | |
837 | tree result, val[3]; | |
838 | tree callee, a; | |
839 | int arg_idx, type; | |
840 | bitmap visited; | |
841 | bool ignore; | |
842 | int nargs; | |
843 | location_t loc = gimple_location (stmt); | |
844 | ||
845 | gcc_assert (is_gimple_call (stmt)); | |
846 | ||
847 | ignore = (gimple_call_lhs (stmt) == NULL); | |
848 | ||
849 | /* First try the generic builtin folder. If that succeeds, return the | |
850 | result directly. */ | |
851 | result = fold_call_stmt (stmt, ignore); | |
852 | if (result) | |
853 | { | |
854 | if (ignore) | |
855 | STRIP_NOPS (result); | |
856 | return result; | |
857 | } | |
858 | ||
859 | /* Ignore MD builtins. */ | |
860 | callee = gimple_call_fndecl (stmt); | |
861 | if (DECL_BUILT_IN_CLASS (callee) == BUILT_IN_MD) | |
862 | return NULL_TREE; | |
863 | ||
51d2c51e | 864 | /* Give up for always_inline inline builtins until they are |
865 | inlined. */ | |
866 | if (avoid_folding_inline_builtin (callee)) | |
867 | return NULL_TREE; | |
868 | ||
2d18b16d | 869 | /* If the builtin could not be folded, and it has no argument list, |
870 | we're done. */ | |
871 | nargs = gimple_call_num_args (stmt); | |
872 | if (nargs == 0) | |
873 | return NULL_TREE; | |
874 | ||
875 | /* Limit the work only for builtins we know how to simplify. */ | |
876 | switch (DECL_FUNCTION_CODE (callee)) | |
877 | { | |
878 | case BUILT_IN_STRLEN: | |
879 | case BUILT_IN_FPUTS: | |
880 | case BUILT_IN_FPUTS_UNLOCKED: | |
881 | arg_idx = 0; | |
882 | type = 0; | |
883 | break; | |
884 | case BUILT_IN_STRCPY: | |
885 | case BUILT_IN_STRNCPY: | |
886 | arg_idx = 1; | |
887 | type = 0; | |
888 | break; | |
889 | case BUILT_IN_MEMCPY_CHK: | |
890 | case BUILT_IN_MEMPCPY_CHK: | |
891 | case BUILT_IN_MEMMOVE_CHK: | |
892 | case BUILT_IN_MEMSET_CHK: | |
893 | case BUILT_IN_STRNCPY_CHK: | |
1063acde | 894 | case BUILT_IN_STPNCPY_CHK: |
2d18b16d | 895 | arg_idx = 2; |
896 | type = 2; | |
897 | break; | |
898 | case BUILT_IN_STRCPY_CHK: | |
899 | case BUILT_IN_STPCPY_CHK: | |
900 | arg_idx = 1; | |
901 | type = 1; | |
902 | break; | |
903 | case BUILT_IN_SNPRINTF_CHK: | |
904 | case BUILT_IN_VSNPRINTF_CHK: | |
905 | arg_idx = 1; | |
906 | type = 2; | |
907 | break; | |
908 | default: | |
909 | return NULL_TREE; | |
910 | } | |
911 | ||
912 | if (arg_idx >= nargs) | |
913 | return NULL_TREE; | |
914 | ||
915 | /* Try to use the dataflow information gathered by the CCP process. */ | |
916 | visited = BITMAP_ALLOC (NULL); | |
917 | bitmap_clear (visited); | |
918 | ||
919 | memset (val, 0, sizeof (val)); | |
920 | a = gimple_call_arg (stmt, arg_idx); | |
921 | if (!get_maxval_strlen (a, &val[arg_idx], visited, type)) | |
922 | val[arg_idx] = NULL_TREE; | |
923 | ||
924 | BITMAP_FREE (visited); | |
925 | ||
926 | result = NULL_TREE; | |
927 | switch (DECL_FUNCTION_CODE (callee)) | |
928 | { | |
929 | case BUILT_IN_STRLEN: | |
930 | if (val[0] && nargs == 1) | |
931 | { | |
932 | tree new_val = | |
933 | fold_convert (TREE_TYPE (gimple_call_lhs (stmt)), val[0]); | |
934 | ||
935 | /* If the result is not a valid gimple value, or not a cast | |
224d1be8 | 936 | of a valid gimple value, then we cannot use the result. */ |
2d18b16d | 937 | if (is_gimple_val (new_val) |
09937c79 | 938 | || (CONVERT_EXPR_P (new_val) |
2d18b16d | 939 | && is_gimple_val (TREE_OPERAND (new_val, 0)))) |
940 | return new_val; | |
941 | } | |
942 | break; | |
943 | ||
944 | case BUILT_IN_STRCPY: | |
945 | if (val[1] && is_gimple_val (val[1]) && nargs == 2) | |
946 | result = fold_builtin_strcpy (loc, callee, | |
947 | gimple_call_arg (stmt, 0), | |
948 | gimple_call_arg (stmt, 1), | |
949 | val[1]); | |
950 | break; | |
951 | ||
952 | case BUILT_IN_STRNCPY: | |
953 | if (val[1] && is_gimple_val (val[1]) && nargs == 3) | |
954 | result = fold_builtin_strncpy (loc, callee, | |
955 | gimple_call_arg (stmt, 0), | |
956 | gimple_call_arg (stmt, 1), | |
957 | gimple_call_arg (stmt, 2), | |
958 | val[1]); | |
959 | break; | |
960 | ||
961 | case BUILT_IN_FPUTS: | |
962 | if (nargs == 2) | |
963 | result = fold_builtin_fputs (loc, gimple_call_arg (stmt, 0), | |
964 | gimple_call_arg (stmt, 1), | |
965 | ignore, false, val[0]); | |
966 | break; | |
967 | ||
968 | case BUILT_IN_FPUTS_UNLOCKED: | |
969 | if (nargs == 2) | |
970 | result = fold_builtin_fputs (loc, gimple_call_arg (stmt, 0), | |
971 | gimple_call_arg (stmt, 1), | |
972 | ignore, true, val[0]); | |
973 | break; | |
974 | ||
975 | case BUILT_IN_MEMCPY_CHK: | |
976 | case BUILT_IN_MEMPCPY_CHK: | |
977 | case BUILT_IN_MEMMOVE_CHK: | |
978 | case BUILT_IN_MEMSET_CHK: | |
979 | if (val[2] && is_gimple_val (val[2]) && nargs == 4) | |
980 | result = fold_builtin_memory_chk (loc, callee, | |
981 | gimple_call_arg (stmt, 0), | |
982 | gimple_call_arg (stmt, 1), | |
983 | gimple_call_arg (stmt, 2), | |
984 | gimple_call_arg (stmt, 3), | |
985 | val[2], ignore, | |
986 | DECL_FUNCTION_CODE (callee)); | |
987 | break; | |
988 | ||
989 | case BUILT_IN_STRCPY_CHK: | |
990 | case BUILT_IN_STPCPY_CHK: | |
991 | if (val[1] && is_gimple_val (val[1]) && nargs == 3) | |
992 | result = fold_builtin_stxcpy_chk (loc, callee, | |
993 | gimple_call_arg (stmt, 0), | |
994 | gimple_call_arg (stmt, 1), | |
995 | gimple_call_arg (stmt, 2), | |
996 | val[1], ignore, | |
997 | DECL_FUNCTION_CODE (callee)); | |
998 | break; | |
999 | ||
1000 | case BUILT_IN_STRNCPY_CHK: | |
1063acde | 1001 | case BUILT_IN_STPNCPY_CHK: |
2d18b16d | 1002 | if (val[2] && is_gimple_val (val[2]) && nargs == 4) |
1063acde | 1003 | result = fold_builtin_stxncpy_chk (loc, gimple_call_arg (stmt, 0), |
2d18b16d | 1004 | gimple_call_arg (stmt, 1), |
1005 | gimple_call_arg (stmt, 2), | |
1006 | gimple_call_arg (stmt, 3), | |
1063acde | 1007 | val[2], ignore, |
1008 | DECL_FUNCTION_CODE (callee)); | |
2d18b16d | 1009 | break; |
1010 | ||
1011 | case BUILT_IN_SNPRINTF_CHK: | |
1012 | case BUILT_IN_VSNPRINTF_CHK: | |
1013 | if (val[1] && is_gimple_val (val[1])) | |
1014 | result = gimple_fold_builtin_snprintf_chk (stmt, val[1], | |
1015 | DECL_FUNCTION_CODE (callee)); | |
1016 | break; | |
1017 | ||
1018 | default: | |
1019 | gcc_unreachable (); | |
1020 | } | |
1021 | ||
1022 | if (result && ignore) | |
1023 | result = fold_ignored_result (result); | |
1024 | return result; | |
1025 | } | |
1026 | ||
e4227d04 | 1027 | |
3658fd1d | 1028 | /* Return a binfo to be used for devirtualization of calls based on an object |
1029 | represented by a declaration (i.e. a global or automatically allocated one) | |
1030 | or NULL if it cannot be found or is not safe. CST is expected to be an | |
1031 | ADDR_EXPR of such object or the function will return NULL. Currently it is | |
fba0273a | 1032 | safe to use such binfo only if it has no base binfo (i.e. no ancestors) |
1033 | EXPECTED_TYPE is type of the class virtual belongs to. */ | |
3658fd1d | 1034 | |
1035 | tree | |
fba0273a | 1036 | gimple_extract_devirt_binfo_from_cst (tree cst, tree expected_type) |
3658fd1d | 1037 | { |
1038 | HOST_WIDE_INT offset, size, max_size; | |
fba0273a | 1039 | tree base, type, binfo; |
3658fd1d | 1040 | bool last_artificial = false; |
1041 | ||
1042 | if (!flag_devirtualize | |
1043 | || TREE_CODE (cst) != ADDR_EXPR | |
1044 | || TREE_CODE (TREE_TYPE (TREE_TYPE (cst))) != RECORD_TYPE) | |
1045 | return NULL_TREE; | |
1046 | ||
1047 | cst = TREE_OPERAND (cst, 0); | |
3658fd1d | 1048 | base = get_ref_base_and_extent (cst, &offset, &size, &max_size); |
1049 | type = TREE_TYPE (base); | |
1050 | if (!DECL_P (base) | |
1051 | || max_size == -1 | |
1052 | || max_size != size | |
1053 | || TREE_CODE (type) != RECORD_TYPE) | |
1054 | return NULL_TREE; | |
1055 | ||
1056 | /* Find the sub-object the constant actually refers to and mark whether it is | |
1057 | an artificial one (as opposed to a user-defined one). */ | |
1058 | while (true) | |
1059 | { | |
1060 | HOST_WIDE_INT pos, size; | |
1061 | tree fld; | |
1062 | ||
7371d299 | 1063 | if (types_same_for_odr (type, expected_type)) |
3658fd1d | 1064 | break; |
1065 | if (offset < 0) | |
1066 | return NULL_TREE; | |
1067 | ||
1068 | for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld)) | |
1069 | { | |
1070 | if (TREE_CODE (fld) != FIELD_DECL) | |
1071 | continue; | |
1072 | ||
1073 | pos = int_bit_position (fld); | |
1074 | size = tree_low_cst (DECL_SIZE (fld), 1); | |
1075 | if (pos <= offset && (pos + size) > offset) | |
1076 | break; | |
1077 | } | |
1078 | if (!fld || TREE_CODE (TREE_TYPE (fld)) != RECORD_TYPE) | |
1079 | return NULL_TREE; | |
1080 | ||
1081 | last_artificial = DECL_ARTIFICIAL (fld); | |
1082 | type = TREE_TYPE (fld); | |
1083 | offset -= pos; | |
1084 | } | |
9d75589a | 1085 | /* Artificial sub-objects are ancestors, we do not want to use them for |
3658fd1d | 1086 | devirtualization, at least not here. */ |
1087 | if (last_artificial) | |
1088 | return NULL_TREE; | |
1089 | binfo = TYPE_BINFO (type); | |
1090 | if (!binfo || BINFO_N_BASE_BINFOS (binfo) > 0) | |
1091 | return NULL_TREE; | |
1092 | else | |
1093 | return binfo; | |
1094 | } | |
1095 | ||
2d18b16d | 1096 | /* Attempt to fold a call statement referenced by the statement iterator GSI. |
1097 | The statement may be replaced by another statement, e.g., if the call | |
1098 | simplifies to a constant value. Return true if any changes were made. | |
1099 | It is assumed that the operands have been previously folded. */ | |
1100 | ||
3aa6ac67 | 1101 | static bool |
3fd0ca33 | 1102 | gimple_fold_call (gimple_stmt_iterator *gsi, bool inplace) |
2d18b16d | 1103 | { |
1104 | gimple stmt = gsi_stmt (*gsi); | |
6fec5449 | 1105 | tree callee; |
3aa6ac67 | 1106 | bool changed = false; |
1107 | unsigned i; | |
2d18b16d | 1108 | |
3aa6ac67 | 1109 | /* Fold *& in call arguments. */ |
1110 | for (i = 0; i < gimple_call_num_args (stmt); ++i) | |
1111 | if (REFERENCE_CLASS_P (gimple_call_arg (stmt, i))) | |
1112 | { | |
1113 | tree tmp = maybe_fold_reference (gimple_call_arg (stmt, i), false); | |
1114 | if (tmp) | |
1115 | { | |
1116 | gimple_call_set_arg (stmt, i, tmp); | |
1117 | changed = true; | |
1118 | } | |
1119 | } | |
6fec5449 | 1120 | |
1121 | /* Check for virtual calls that became direct calls. */ | |
1122 | callee = gimple_call_fn (stmt); | |
fb049fba | 1123 | if (callee && TREE_CODE (callee) == OBJ_TYPE_REF) |
6fec5449 | 1124 | { |
3658fd1d | 1125 | if (gimple_call_addr_fndecl (OBJ_TYPE_REF_EXPR (callee)) != NULL_TREE) |
1126 | { | |
10fba9c0 | 1127 | if (dump_file && virtual_method_call_p (callee) |
1128 | && !possible_polymorphic_call_target_p | |
1129 | (callee, cgraph_get_node (gimple_call_addr_fndecl | |
1130 | (OBJ_TYPE_REF_EXPR (callee))))) | |
1131 | { | |
1132 | fprintf (dump_file, | |
1133 | "Type inheritnace inconsistent devirtualization of "); | |
1134 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1135 | fprintf (dump_file, " to "); | |
1136 | print_generic_expr (dump_file, callee, TDF_SLIM); | |
1137 | fprintf (dump_file, "\n"); | |
1138 | } | |
1139 | ||
3658fd1d | 1140 | gimple_call_set_fn (stmt, OBJ_TYPE_REF_EXPR (callee)); |
3aa6ac67 | 1141 | changed = true; |
1142 | } | |
f5e35fed | 1143 | else if (virtual_method_call_p (callee)) |
3aa6ac67 | 1144 | { |
1145 | tree obj = OBJ_TYPE_REF_OBJECT (callee); | |
fba0273a | 1146 | tree binfo = gimple_extract_devirt_binfo_from_cst |
1147 | (obj, obj_type_ref_class (callee)); | |
3aa6ac67 | 1148 | if (binfo) |
1149 | { | |
1150 | HOST_WIDE_INT token | |
1151 | = TREE_INT_CST_LOW (OBJ_TYPE_REF_TOKEN (callee)); | |
1152 | tree fndecl = gimple_get_virt_method_for_binfo (token, binfo); | |
1153 | if (fndecl) | |
1154 | { | |
10fba9c0 | 1155 | #ifdef ENABLE_CHECKING |
1156 | gcc_assert (possible_polymorphic_call_target_p | |
1157 | (callee, cgraph_get_node (fndecl))); | |
1158 | ||
1159 | #endif | |
3aa6ac67 | 1160 | gimple_call_set_fndecl (stmt, fndecl); |
1161 | changed = true; | |
1162 | } | |
1163 | } | |
3658fd1d | 1164 | } |
3aa6ac67 | 1165 | } |
3658fd1d | 1166 | |
3aa6ac67 | 1167 | if (inplace) |
1168 | return changed; | |
1169 | ||
1170 | /* Check for builtins that CCP can handle using information not | |
1171 | available in the generic fold routines. */ | |
f883da84 | 1172 | callee = gimple_call_fndecl (stmt); |
3aa6ac67 | 1173 | if (callee && DECL_BUILT_IN (callee)) |
1174 | { | |
1175 | tree result = gimple_fold_builtin (stmt); | |
734244a6 | 1176 | if (result) |
3aa6ac67 | 1177 | { |
1178 | if (!update_call_from_tree (gsi, result)) | |
1179 | gimplify_and_update_call_from_tree (gsi, result); | |
1180 | changed = true; | |
1181 | } | |
29cad3b6 | 1182 | else if (DECL_BUILT_IN_CLASS (callee) == BUILT_IN_MD) |
1183 | changed |= targetm.gimple_fold_builtin (gsi); | |
6fec5449 | 1184 | } |
1185 | ||
3aa6ac67 | 1186 | return changed; |
2d18b16d | 1187 | } |
1188 | ||
1189 | /* Worker for both fold_stmt and fold_stmt_inplace. The INPLACE argument | |
1190 | distinguishes both cases. */ | |
1191 | ||
1192 | static bool | |
1193 | fold_stmt_1 (gimple_stmt_iterator *gsi, bool inplace) | |
1194 | { | |
1195 | bool changed = false; | |
1196 | gimple stmt = gsi_stmt (*gsi); | |
1197 | unsigned i; | |
1198 | ||
1199 | /* Fold the main computation performed by the statement. */ | |
1200 | switch (gimple_code (stmt)) | |
1201 | { | |
1202 | case GIMPLE_ASSIGN: | |
1203 | { | |
1204 | unsigned old_num_ops = gimple_num_ops (stmt); | |
fbd25d42 | 1205 | enum tree_code subcode = gimple_assign_rhs_code (stmt); |
2d18b16d | 1206 | tree lhs = gimple_assign_lhs (stmt); |
fbd25d42 | 1207 | tree new_rhs; |
1208 | /* First canonicalize operand order. This avoids building new | |
1209 | trees if this is the only thing fold would later do. */ | |
1210 | if ((commutative_tree_code (subcode) | |
1211 | || commutative_ternary_tree_code (subcode)) | |
1212 | && tree_swap_operands_p (gimple_assign_rhs1 (stmt), | |
1213 | gimple_assign_rhs2 (stmt), false)) | |
1214 | { | |
1215 | tree tem = gimple_assign_rhs1 (stmt); | |
1216 | gimple_assign_set_rhs1 (stmt, gimple_assign_rhs2 (stmt)); | |
1217 | gimple_assign_set_rhs2 (stmt, tem); | |
1218 | changed = true; | |
1219 | } | |
1220 | new_rhs = fold_gimple_assign (gsi); | |
2d18b16d | 1221 | if (new_rhs |
1222 | && !useless_type_conversion_p (TREE_TYPE (lhs), | |
1223 | TREE_TYPE (new_rhs))) | |
1224 | new_rhs = fold_convert (TREE_TYPE (lhs), new_rhs); | |
1225 | if (new_rhs | |
1226 | && (!inplace | |
1227 | || get_gimple_rhs_num_ops (TREE_CODE (new_rhs)) < old_num_ops)) | |
1228 | { | |
1229 | gimple_assign_set_rhs_from_tree (gsi, new_rhs); | |
1230 | changed = true; | |
1231 | } | |
1232 | break; | |
1233 | } | |
1234 | ||
1235 | case GIMPLE_COND: | |
1236 | changed |= fold_gimple_cond (stmt); | |
1237 | break; | |
1238 | ||
1239 | case GIMPLE_CALL: | |
3fd0ca33 | 1240 | changed |= gimple_fold_call (gsi, inplace); |
2d18b16d | 1241 | break; |
1242 | ||
1243 | case GIMPLE_ASM: | |
1244 | /* Fold *& in asm operands. */ | |
a02dcaf7 | 1245 | { |
1246 | size_t noutputs; | |
1247 | const char **oconstraints; | |
1248 | const char *constraint; | |
1249 | bool allows_mem, allows_reg; | |
1250 | ||
1251 | noutputs = gimple_asm_noutputs (stmt); | |
1252 | oconstraints = XALLOCAVEC (const char *, noutputs); | |
1253 | ||
1254 | for (i = 0; i < gimple_asm_noutputs (stmt); ++i) | |
1255 | { | |
1256 | tree link = gimple_asm_output_op (stmt, i); | |
1257 | tree op = TREE_VALUE (link); | |
1258 | oconstraints[i] | |
1259 | = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link))); | |
1260 | if (REFERENCE_CLASS_P (op) | |
1261 | && (op = maybe_fold_reference (op, true)) != NULL_TREE) | |
1262 | { | |
1263 | TREE_VALUE (link) = op; | |
1264 | changed = true; | |
1265 | } | |
1266 | } | |
1267 | for (i = 0; i < gimple_asm_ninputs (stmt); ++i) | |
1268 | { | |
1269 | tree link = gimple_asm_input_op (stmt, i); | |
1270 | tree op = TREE_VALUE (link); | |
1271 | constraint | |
1272 | = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link))); | |
1273 | parse_input_constraint (&constraint, 0, 0, noutputs, 0, | |
1274 | oconstraints, &allows_mem, &allows_reg); | |
1275 | if (REFERENCE_CLASS_P (op) | |
1276 | && (op = maybe_fold_reference (op, !allows_reg && allows_mem)) | |
1277 | != NULL_TREE) | |
1278 | { | |
1279 | TREE_VALUE (link) = op; | |
1280 | changed = true; | |
1281 | } | |
1282 | } | |
1283 | } | |
2d18b16d | 1284 | break; |
1285 | ||
69f01c7b | 1286 | case GIMPLE_DEBUG: |
1287 | if (gimple_debug_bind_p (stmt)) | |
1288 | { | |
1289 | tree val = gimple_debug_bind_get_value (stmt); | |
1290 | if (val | |
1291 | && REFERENCE_CLASS_P (val)) | |
1292 | { | |
1293 | tree tem = maybe_fold_reference (val, false); | |
1294 | if (tem) | |
1295 | { | |
1296 | gimple_debug_bind_set_value (stmt, tem); | |
1297 | changed = true; | |
1298 | } | |
1299 | } | |
48bcb852 | 1300 | else if (val |
1301 | && TREE_CODE (val) == ADDR_EXPR) | |
1302 | { | |
1303 | tree ref = TREE_OPERAND (val, 0); | |
1304 | tree tem = maybe_fold_reference (ref, false); | |
1305 | if (tem) | |
1306 | { | |
1307 | tem = build_fold_addr_expr_with_type (tem, TREE_TYPE (val)); | |
1308 | gimple_debug_bind_set_value (stmt, tem); | |
1309 | changed = true; | |
1310 | } | |
1311 | } | |
69f01c7b | 1312 | } |
1313 | break; | |
1314 | ||
2d18b16d | 1315 | default:; |
1316 | } | |
1317 | ||
1318 | stmt = gsi_stmt (*gsi); | |
1319 | ||
5352fc9b | 1320 | /* Fold *& on the lhs. */ |
1321 | if (gimple_has_lhs (stmt)) | |
2d18b16d | 1322 | { |
1323 | tree lhs = gimple_get_lhs (stmt); | |
1324 | if (lhs && REFERENCE_CLASS_P (lhs)) | |
1325 | { | |
1326 | tree new_lhs = maybe_fold_reference (lhs, true); | |
1327 | if (new_lhs) | |
1328 | { | |
1329 | gimple_set_lhs (stmt, new_lhs); | |
1330 | changed = true; | |
1331 | } | |
1332 | } | |
1333 | } | |
1334 | ||
1335 | return changed; | |
1336 | } | |
1337 | ||
1338 | /* Fold the statement pointed to by GSI. In some cases, this function may | |
1339 | replace the whole statement with a new one. Returns true iff folding | |
1340 | makes any changes. | |
1341 | The statement pointed to by GSI should be in valid gimple form but may | |
1342 | be in unfolded state as resulting from for example constant propagation | |
1343 | which can produce *&x = 0. */ | |
1344 | ||
1345 | bool | |
1346 | fold_stmt (gimple_stmt_iterator *gsi) | |
1347 | { | |
1348 | return fold_stmt_1 (gsi, false); | |
1349 | } | |
1350 | ||
50aacf4c | 1351 | /* Perform the minimal folding on statement *GSI. Only operations like |
2d18b16d | 1352 | *&x created by constant propagation are handled. The statement cannot |
1353 | be replaced with a new one. Return true if the statement was | |
1354 | changed, false otherwise. | |
50aacf4c | 1355 | The statement *GSI should be in valid gimple form but may |
2d18b16d | 1356 | be in unfolded state as resulting from for example constant propagation |
1357 | which can produce *&x = 0. */ | |
1358 | ||
1359 | bool | |
50aacf4c | 1360 | fold_stmt_inplace (gimple_stmt_iterator *gsi) |
2d18b16d | 1361 | { |
50aacf4c | 1362 | gimple stmt = gsi_stmt (*gsi); |
1363 | bool changed = fold_stmt_1 (gsi, true); | |
1364 | gcc_assert (gsi_stmt (*gsi) == stmt); | |
2d18b16d | 1365 | return changed; |
1366 | } | |
1367 | ||
c82d157a | 1368 | /* Canonicalize and possibly invert the boolean EXPR; return NULL_TREE |
1369 | if EXPR is null or we don't know how. | |
1370 | If non-null, the result always has boolean type. */ | |
1371 | ||
1372 | static tree | |
1373 | canonicalize_bool (tree expr, bool invert) | |
1374 | { | |
1375 | if (!expr) | |
1376 | return NULL_TREE; | |
1377 | else if (invert) | |
1378 | { | |
1379 | if (integer_nonzerop (expr)) | |
1380 | return boolean_false_node; | |
1381 | else if (integer_zerop (expr)) | |
1382 | return boolean_true_node; | |
1383 | else if (TREE_CODE (expr) == SSA_NAME) | |
1384 | return fold_build2 (EQ_EXPR, boolean_type_node, expr, | |
1385 | build_int_cst (TREE_TYPE (expr), 0)); | |
1386 | else if (TREE_CODE_CLASS (TREE_CODE (expr)) == tcc_comparison) | |
1387 | return fold_build2 (invert_tree_comparison (TREE_CODE (expr), false), | |
1388 | boolean_type_node, | |
1389 | TREE_OPERAND (expr, 0), | |
1390 | TREE_OPERAND (expr, 1)); | |
1391 | else | |
1392 | return NULL_TREE; | |
1393 | } | |
1394 | else | |
1395 | { | |
1396 | if (TREE_CODE (TREE_TYPE (expr)) == BOOLEAN_TYPE) | |
1397 | return expr; | |
1398 | if (integer_nonzerop (expr)) | |
1399 | return boolean_true_node; | |
1400 | else if (integer_zerop (expr)) | |
1401 | return boolean_false_node; | |
1402 | else if (TREE_CODE (expr) == SSA_NAME) | |
1403 | return fold_build2 (NE_EXPR, boolean_type_node, expr, | |
1404 | build_int_cst (TREE_TYPE (expr), 0)); | |
1405 | else if (TREE_CODE_CLASS (TREE_CODE (expr)) == tcc_comparison) | |
1406 | return fold_build2 (TREE_CODE (expr), | |
1407 | boolean_type_node, | |
1408 | TREE_OPERAND (expr, 0), | |
1409 | TREE_OPERAND (expr, 1)); | |
1410 | else | |
1411 | return NULL_TREE; | |
1412 | } | |
1413 | } | |
1414 | ||
1415 | /* Check to see if a boolean expression EXPR is logically equivalent to the | |
1416 | comparison (OP1 CODE OP2). Check for various identities involving | |
1417 | SSA_NAMEs. */ | |
1418 | ||
1419 | static bool | |
1420 | same_bool_comparison_p (const_tree expr, enum tree_code code, | |
1421 | const_tree op1, const_tree op2) | |
1422 | { | |
1423 | gimple s; | |
1424 | ||
1425 | /* The obvious case. */ | |
1426 | if (TREE_CODE (expr) == code | |
1427 | && operand_equal_p (TREE_OPERAND (expr, 0), op1, 0) | |
1428 | && operand_equal_p (TREE_OPERAND (expr, 1), op2, 0)) | |
1429 | return true; | |
1430 | ||
1431 | /* Check for comparing (name, name != 0) and the case where expr | |
1432 | is an SSA_NAME with a definition matching the comparison. */ | |
1433 | if (TREE_CODE (expr) == SSA_NAME | |
1434 | && TREE_CODE (TREE_TYPE (expr)) == BOOLEAN_TYPE) | |
1435 | { | |
1436 | if (operand_equal_p (expr, op1, 0)) | |
1437 | return ((code == NE_EXPR && integer_zerop (op2)) | |
1438 | || (code == EQ_EXPR && integer_nonzerop (op2))); | |
1439 | s = SSA_NAME_DEF_STMT (expr); | |
1440 | if (is_gimple_assign (s) | |
1441 | && gimple_assign_rhs_code (s) == code | |
1442 | && operand_equal_p (gimple_assign_rhs1 (s), op1, 0) | |
1443 | && operand_equal_p (gimple_assign_rhs2 (s), op2, 0)) | |
1444 | return true; | |
1445 | } | |
1446 | ||
1447 | /* If op1 is of the form (name != 0) or (name == 0), and the definition | |
1448 | of name is a comparison, recurse. */ | |
1449 | if (TREE_CODE (op1) == SSA_NAME | |
1450 | && TREE_CODE (TREE_TYPE (op1)) == BOOLEAN_TYPE) | |
1451 | { | |
1452 | s = SSA_NAME_DEF_STMT (op1); | |
1453 | if (is_gimple_assign (s) | |
1454 | && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison) | |
1455 | { | |
1456 | enum tree_code c = gimple_assign_rhs_code (s); | |
1457 | if ((c == NE_EXPR && integer_zerop (op2)) | |
1458 | || (c == EQ_EXPR && integer_nonzerop (op2))) | |
1459 | return same_bool_comparison_p (expr, c, | |
1460 | gimple_assign_rhs1 (s), | |
1461 | gimple_assign_rhs2 (s)); | |
1462 | if ((c == EQ_EXPR && integer_zerop (op2)) | |
1463 | || (c == NE_EXPR && integer_nonzerop (op2))) | |
1464 | return same_bool_comparison_p (expr, | |
1465 | invert_tree_comparison (c, false), | |
1466 | gimple_assign_rhs1 (s), | |
1467 | gimple_assign_rhs2 (s)); | |
1468 | } | |
1469 | } | |
1470 | return false; | |
1471 | } | |
1472 | ||
1473 | /* Check to see if two boolean expressions OP1 and OP2 are logically | |
1474 | equivalent. */ | |
1475 | ||
1476 | static bool | |
1477 | same_bool_result_p (const_tree op1, const_tree op2) | |
1478 | { | |
1479 | /* Simple cases first. */ | |
1480 | if (operand_equal_p (op1, op2, 0)) | |
1481 | return true; | |
1482 | ||
1483 | /* Check the cases where at least one of the operands is a comparison. | |
1484 | These are a bit smarter than operand_equal_p in that they apply some | |
1485 | identifies on SSA_NAMEs. */ | |
1486 | if (TREE_CODE_CLASS (TREE_CODE (op2)) == tcc_comparison | |
1487 | && same_bool_comparison_p (op1, TREE_CODE (op2), | |
1488 | TREE_OPERAND (op2, 0), | |
1489 | TREE_OPERAND (op2, 1))) | |
1490 | return true; | |
1491 | if (TREE_CODE_CLASS (TREE_CODE (op1)) == tcc_comparison | |
1492 | && same_bool_comparison_p (op2, TREE_CODE (op1), | |
1493 | TREE_OPERAND (op1, 0), | |
1494 | TREE_OPERAND (op1, 1))) | |
1495 | return true; | |
1496 | ||
1497 | /* Default case. */ | |
1498 | return false; | |
1499 | } | |
1500 | ||
1501 | /* Forward declarations for some mutually recursive functions. */ | |
1502 | ||
1503 | static tree | |
1504 | and_comparisons_1 (enum tree_code code1, tree op1a, tree op1b, | |
1505 | enum tree_code code2, tree op2a, tree op2b); | |
1506 | static tree | |
1507 | and_var_with_comparison (tree var, bool invert, | |
1508 | enum tree_code code2, tree op2a, tree op2b); | |
1509 | static tree | |
1510 | and_var_with_comparison_1 (gimple stmt, | |
1511 | enum tree_code code2, tree op2a, tree op2b); | |
1512 | static tree | |
1513 | or_comparisons_1 (enum tree_code code1, tree op1a, tree op1b, | |
1514 | enum tree_code code2, tree op2a, tree op2b); | |
1515 | static tree | |
1516 | or_var_with_comparison (tree var, bool invert, | |
1517 | enum tree_code code2, tree op2a, tree op2b); | |
1518 | static tree | |
1519 | or_var_with_comparison_1 (gimple stmt, | |
1520 | enum tree_code code2, tree op2a, tree op2b); | |
1521 | ||
1522 | /* Helper function for and_comparisons_1: try to simplify the AND of the | |
1523 | ssa variable VAR with the comparison specified by (OP2A CODE2 OP2B). | |
1524 | If INVERT is true, invert the value of the VAR before doing the AND. | |
1525 | Return NULL_EXPR if we can't simplify this to a single expression. */ | |
1526 | ||
1527 | static tree | |
1528 | and_var_with_comparison (tree var, bool invert, | |
1529 | enum tree_code code2, tree op2a, tree op2b) | |
1530 | { | |
1531 | tree t; | |
1532 | gimple stmt = SSA_NAME_DEF_STMT (var); | |
1533 | ||
1534 | /* We can only deal with variables whose definitions are assignments. */ | |
1535 | if (!is_gimple_assign (stmt)) | |
1536 | return NULL_TREE; | |
1537 | ||
1538 | /* If we have an inverted comparison, apply DeMorgan's law and rewrite | |
1539 | !var AND (op2a code2 op2b) => !(var OR !(op2a code2 op2b)) | |
1540 | Then we only have to consider the simpler non-inverted cases. */ | |
1541 | if (invert) | |
1542 | t = or_var_with_comparison_1 (stmt, | |
1543 | invert_tree_comparison (code2, false), | |
1544 | op2a, op2b); | |
1545 | else | |
1546 | t = and_var_with_comparison_1 (stmt, code2, op2a, op2b); | |
1547 | return canonicalize_bool (t, invert); | |
1548 | } | |
1549 | ||
1550 | /* Try to simplify the AND of the ssa variable defined by the assignment | |
1551 | STMT with the comparison specified by (OP2A CODE2 OP2B). | |
1552 | Return NULL_EXPR if we can't simplify this to a single expression. */ | |
1553 | ||
1554 | static tree | |
1555 | and_var_with_comparison_1 (gimple stmt, | |
1556 | enum tree_code code2, tree op2a, tree op2b) | |
1557 | { | |
1558 | tree var = gimple_assign_lhs (stmt); | |
1559 | tree true_test_var = NULL_TREE; | |
1560 | tree false_test_var = NULL_TREE; | |
1561 | enum tree_code innercode = gimple_assign_rhs_code (stmt); | |
1562 | ||
1563 | /* Check for identities like (var AND (var == 0)) => false. */ | |
1564 | if (TREE_CODE (op2a) == SSA_NAME | |
1565 | && TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE) | |
1566 | { | |
1567 | if ((code2 == NE_EXPR && integer_zerop (op2b)) | |
1568 | || (code2 == EQ_EXPR && integer_nonzerop (op2b))) | |
1569 | { | |
1570 | true_test_var = op2a; | |
1571 | if (var == true_test_var) | |
1572 | return var; | |
1573 | } | |
1574 | else if ((code2 == EQ_EXPR && integer_zerop (op2b)) | |
1575 | || (code2 == NE_EXPR && integer_nonzerop (op2b))) | |
1576 | { | |
1577 | false_test_var = op2a; | |
1578 | if (var == false_test_var) | |
1579 | return boolean_false_node; | |
1580 | } | |
1581 | } | |
1582 | ||
1583 | /* If the definition is a comparison, recurse on it. */ | |
1584 | if (TREE_CODE_CLASS (innercode) == tcc_comparison) | |
1585 | { | |
1586 | tree t = and_comparisons_1 (innercode, | |
1587 | gimple_assign_rhs1 (stmt), | |
1588 | gimple_assign_rhs2 (stmt), | |
1589 | code2, | |
1590 | op2a, | |
1591 | op2b); | |
1592 | if (t) | |
1593 | return t; | |
1594 | } | |
1595 | ||
1596 | /* If the definition is an AND or OR expression, we may be able to | |
1597 | simplify by reassociating. */ | |
08410c65 | 1598 | if (TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE |
1599 | && (innercode == BIT_AND_EXPR || innercode == BIT_IOR_EXPR)) | |
c82d157a | 1600 | { |
1601 | tree inner1 = gimple_assign_rhs1 (stmt); | |
1602 | tree inner2 = gimple_assign_rhs2 (stmt); | |
1603 | gimple s; | |
1604 | tree t; | |
1605 | tree partial = NULL_TREE; | |
08410c65 | 1606 | bool is_and = (innercode == BIT_AND_EXPR); |
c82d157a | 1607 | |
1608 | /* Check for boolean identities that don't require recursive examination | |
1609 | of inner1/inner2: | |
1610 | inner1 AND (inner1 AND inner2) => inner1 AND inner2 => var | |
1611 | inner1 AND (inner1 OR inner2) => inner1 | |
1612 | !inner1 AND (inner1 AND inner2) => false | |
1613 | !inner1 AND (inner1 OR inner2) => !inner1 AND inner2 | |
1614 | Likewise for similar cases involving inner2. */ | |
1615 | if (inner1 == true_test_var) | |
1616 | return (is_and ? var : inner1); | |
1617 | else if (inner2 == true_test_var) | |
1618 | return (is_and ? var : inner2); | |
1619 | else if (inner1 == false_test_var) | |
1620 | return (is_and | |
1621 | ? boolean_false_node | |
1622 | : and_var_with_comparison (inner2, false, code2, op2a, op2b)); | |
1623 | else if (inner2 == false_test_var) | |
1624 | return (is_and | |
1625 | ? boolean_false_node | |
1626 | : and_var_with_comparison (inner1, false, code2, op2a, op2b)); | |
1627 | ||
1628 | /* Next, redistribute/reassociate the AND across the inner tests. | |
1629 | Compute the first partial result, (inner1 AND (op2a code op2b)) */ | |
1630 | if (TREE_CODE (inner1) == SSA_NAME | |
1631 | && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner1)) | |
1632 | && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison | |
1633 | && (t = maybe_fold_and_comparisons (gimple_assign_rhs_code (s), | |
1634 | gimple_assign_rhs1 (s), | |
1635 | gimple_assign_rhs2 (s), | |
1636 | code2, op2a, op2b))) | |
1637 | { | |
1638 | /* Handle the AND case, where we are reassociating: | |
1639 | (inner1 AND inner2) AND (op2a code2 op2b) | |
1640 | => (t AND inner2) | |
1641 | If the partial result t is a constant, we win. Otherwise | |
1642 | continue on to try reassociating with the other inner test. */ | |
1643 | if (is_and) | |
1644 | { | |
1645 | if (integer_onep (t)) | |
1646 | return inner2; | |
1647 | else if (integer_zerop (t)) | |
1648 | return boolean_false_node; | |
1649 | } | |
1650 | ||
1651 | /* Handle the OR case, where we are redistributing: | |
1652 | (inner1 OR inner2) AND (op2a code2 op2b) | |
1653 | => (t OR (inner2 AND (op2a code2 op2b))) */ | |
ad1e8581 | 1654 | else if (integer_onep (t)) |
1655 | return boolean_true_node; | |
1656 | ||
1657 | /* Save partial result for later. */ | |
1658 | partial = t; | |
c82d157a | 1659 | } |
1660 | ||
1661 | /* Compute the second partial result, (inner2 AND (op2a code op2b)) */ | |
1662 | if (TREE_CODE (inner2) == SSA_NAME | |
1663 | && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner2)) | |
1664 | && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison | |
1665 | && (t = maybe_fold_and_comparisons (gimple_assign_rhs_code (s), | |
1666 | gimple_assign_rhs1 (s), | |
1667 | gimple_assign_rhs2 (s), | |
1668 | code2, op2a, op2b))) | |
1669 | { | |
1670 | /* Handle the AND case, where we are reassociating: | |
1671 | (inner1 AND inner2) AND (op2a code2 op2b) | |
1672 | => (inner1 AND t) */ | |
1673 | if (is_and) | |
1674 | { | |
1675 | if (integer_onep (t)) | |
1676 | return inner1; | |
1677 | else if (integer_zerop (t)) | |
1678 | return boolean_false_node; | |
ad1e8581 | 1679 | /* If both are the same, we can apply the identity |
1680 | (x AND x) == x. */ | |
1681 | else if (partial && same_bool_result_p (t, partial)) | |
1682 | return t; | |
c82d157a | 1683 | } |
1684 | ||
1685 | /* Handle the OR case. where we are redistributing: | |
1686 | (inner1 OR inner2) AND (op2a code2 op2b) | |
1687 | => (t OR (inner1 AND (op2a code2 op2b))) | |
1688 | => (t OR partial) */ | |
1689 | else | |
1690 | { | |
1691 | if (integer_onep (t)) | |
1692 | return boolean_true_node; | |
1693 | else if (partial) | |
1694 | { | |
1695 | /* We already got a simplification for the other | |
1696 | operand to the redistributed OR expression. The | |
1697 | interesting case is when at least one is false. | |
1698 | Or, if both are the same, we can apply the identity | |
1699 | (x OR x) == x. */ | |
1700 | if (integer_zerop (partial)) | |
1701 | return t; | |
1702 | else if (integer_zerop (t)) | |
1703 | return partial; | |
1704 | else if (same_bool_result_p (t, partial)) | |
1705 | return t; | |
1706 | } | |
1707 | } | |
1708 | } | |
1709 | } | |
1710 | return NULL_TREE; | |
1711 | } | |
1712 | ||
1713 | /* Try to simplify the AND of two comparisons defined by | |
1714 | (OP1A CODE1 OP1B) and (OP2A CODE2 OP2B), respectively. | |
1715 | If this can be done without constructing an intermediate value, | |
1716 | return the resulting tree; otherwise NULL_TREE is returned. | |
1717 | This function is deliberately asymmetric as it recurses on SSA_DEFs | |
1718 | in the first comparison but not the second. */ | |
1719 | ||
1720 | static tree | |
1721 | and_comparisons_1 (enum tree_code code1, tree op1a, tree op1b, | |
1722 | enum tree_code code2, tree op2a, tree op2b) | |
1723 | { | |
f2c1848b | 1724 | tree truth_type = truth_type_for (TREE_TYPE (op1a)); |
357d8e5d | 1725 | |
c82d157a | 1726 | /* First check for ((x CODE1 y) AND (x CODE2 y)). */ |
1727 | if (operand_equal_p (op1a, op2a, 0) | |
1728 | && operand_equal_p (op1b, op2b, 0)) | |
1729 | { | |
08410c65 | 1730 | /* Result will be either NULL_TREE, or a combined comparison. */ |
c82d157a | 1731 | tree t = combine_comparisons (UNKNOWN_LOCATION, |
1732 | TRUTH_ANDIF_EXPR, code1, code2, | |
357d8e5d | 1733 | truth_type, op1a, op1b); |
c82d157a | 1734 | if (t) |
1735 | return t; | |
1736 | } | |
1737 | ||
1738 | /* Likewise the swapped case of the above. */ | |
1739 | if (operand_equal_p (op1a, op2b, 0) | |
1740 | && operand_equal_p (op1b, op2a, 0)) | |
1741 | { | |
08410c65 | 1742 | /* Result will be either NULL_TREE, or a combined comparison. */ |
c82d157a | 1743 | tree t = combine_comparisons (UNKNOWN_LOCATION, |
1744 | TRUTH_ANDIF_EXPR, code1, | |
1745 | swap_tree_comparison (code2), | |
357d8e5d | 1746 | truth_type, op1a, op1b); |
c82d157a | 1747 | if (t) |
1748 | return t; | |
1749 | } | |
1750 | ||
1751 | /* If both comparisons are of the same value against constants, we might | |
1752 | be able to merge them. */ | |
1753 | if (operand_equal_p (op1a, op2a, 0) | |
1754 | && TREE_CODE (op1b) == INTEGER_CST | |
1755 | && TREE_CODE (op2b) == INTEGER_CST) | |
1756 | { | |
1757 | int cmp = tree_int_cst_compare (op1b, op2b); | |
1758 | ||
1759 | /* If we have (op1a == op1b), we should either be able to | |
1760 | return that or FALSE, depending on whether the constant op1b | |
1761 | also satisfies the other comparison against op2b. */ | |
1762 | if (code1 == EQ_EXPR) | |
1763 | { | |
1764 | bool done = true; | |
1765 | bool val; | |
1766 | switch (code2) | |
1767 | { | |
1768 | case EQ_EXPR: val = (cmp == 0); break; | |
1769 | case NE_EXPR: val = (cmp != 0); break; | |
1770 | case LT_EXPR: val = (cmp < 0); break; | |
1771 | case GT_EXPR: val = (cmp > 0); break; | |
1772 | case LE_EXPR: val = (cmp <= 0); break; | |
1773 | case GE_EXPR: val = (cmp >= 0); break; | |
1774 | default: done = false; | |
1775 | } | |
1776 | if (done) | |
1777 | { | |
1778 | if (val) | |
1779 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
1780 | else | |
1781 | return boolean_false_node; | |
1782 | } | |
1783 | } | |
1784 | /* Likewise if the second comparison is an == comparison. */ | |
1785 | else if (code2 == EQ_EXPR) | |
1786 | { | |
1787 | bool done = true; | |
1788 | bool val; | |
1789 | switch (code1) | |
1790 | { | |
1791 | case EQ_EXPR: val = (cmp == 0); break; | |
1792 | case NE_EXPR: val = (cmp != 0); break; | |
1793 | case LT_EXPR: val = (cmp > 0); break; | |
1794 | case GT_EXPR: val = (cmp < 0); break; | |
1795 | case LE_EXPR: val = (cmp >= 0); break; | |
1796 | case GE_EXPR: val = (cmp <= 0); break; | |
1797 | default: done = false; | |
1798 | } | |
1799 | if (done) | |
1800 | { | |
1801 | if (val) | |
1802 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
1803 | else | |
1804 | return boolean_false_node; | |
1805 | } | |
1806 | } | |
1807 | ||
1808 | /* Same business with inequality tests. */ | |
1809 | else if (code1 == NE_EXPR) | |
1810 | { | |
1811 | bool val; | |
1812 | switch (code2) | |
1813 | { | |
1814 | case EQ_EXPR: val = (cmp != 0); break; | |
1815 | case NE_EXPR: val = (cmp == 0); break; | |
1816 | case LT_EXPR: val = (cmp >= 0); break; | |
1817 | case GT_EXPR: val = (cmp <= 0); break; | |
1818 | case LE_EXPR: val = (cmp > 0); break; | |
1819 | case GE_EXPR: val = (cmp < 0); break; | |
1820 | default: | |
1821 | val = false; | |
1822 | } | |
1823 | if (val) | |
1824 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
1825 | } | |
1826 | else if (code2 == NE_EXPR) | |
1827 | { | |
1828 | bool val; | |
1829 | switch (code1) | |
1830 | { | |
1831 | case EQ_EXPR: val = (cmp == 0); break; | |
1832 | case NE_EXPR: val = (cmp != 0); break; | |
1833 | case LT_EXPR: val = (cmp <= 0); break; | |
1834 | case GT_EXPR: val = (cmp >= 0); break; | |
1835 | case LE_EXPR: val = (cmp < 0); break; | |
1836 | case GE_EXPR: val = (cmp > 0); break; | |
1837 | default: | |
1838 | val = false; | |
1839 | } | |
1840 | if (val) | |
1841 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
1842 | } | |
1843 | ||
1844 | /* Chose the more restrictive of two < or <= comparisons. */ | |
1845 | else if ((code1 == LT_EXPR || code1 == LE_EXPR) | |
1846 | && (code2 == LT_EXPR || code2 == LE_EXPR)) | |
1847 | { | |
1848 | if ((cmp < 0) || (cmp == 0 && code1 == LT_EXPR)) | |
1849 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
1850 | else | |
1851 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
1852 | } | |
1853 | ||
1854 | /* Likewise chose the more restrictive of two > or >= comparisons. */ | |
1855 | else if ((code1 == GT_EXPR || code1 == GE_EXPR) | |
1856 | && (code2 == GT_EXPR || code2 == GE_EXPR)) | |
1857 | { | |
1858 | if ((cmp > 0) || (cmp == 0 && code1 == GT_EXPR)) | |
1859 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
1860 | else | |
1861 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
1862 | } | |
1863 | ||
1864 | /* Check for singleton ranges. */ | |
1865 | else if (cmp == 0 | |
1866 | && ((code1 == LE_EXPR && code2 == GE_EXPR) | |
1867 | || (code1 == GE_EXPR && code2 == LE_EXPR))) | |
1868 | return fold_build2 (EQ_EXPR, boolean_type_node, op1a, op2b); | |
1869 | ||
1870 | /* Check for disjoint ranges. */ | |
1871 | else if (cmp <= 0 | |
1872 | && (code1 == LT_EXPR || code1 == LE_EXPR) | |
1873 | && (code2 == GT_EXPR || code2 == GE_EXPR)) | |
1874 | return boolean_false_node; | |
1875 | else if (cmp >= 0 | |
1876 | && (code1 == GT_EXPR || code1 == GE_EXPR) | |
1877 | && (code2 == LT_EXPR || code2 == LE_EXPR)) | |
1878 | return boolean_false_node; | |
1879 | } | |
1880 | ||
1881 | /* Perhaps the first comparison is (NAME != 0) or (NAME == 1) where | |
1882 | NAME's definition is a truth value. See if there are any simplifications | |
1883 | that can be done against the NAME's definition. */ | |
1884 | if (TREE_CODE (op1a) == SSA_NAME | |
1885 | && (code1 == NE_EXPR || code1 == EQ_EXPR) | |
1886 | && (integer_zerop (op1b) || integer_onep (op1b))) | |
1887 | { | |
1888 | bool invert = ((code1 == EQ_EXPR && integer_zerop (op1b)) | |
1889 | || (code1 == NE_EXPR && integer_onep (op1b))); | |
1890 | gimple stmt = SSA_NAME_DEF_STMT (op1a); | |
1891 | switch (gimple_code (stmt)) | |
1892 | { | |
1893 | case GIMPLE_ASSIGN: | |
1894 | /* Try to simplify by copy-propagating the definition. */ | |
1895 | return and_var_with_comparison (op1a, invert, code2, op2a, op2b); | |
1896 | ||
1897 | case GIMPLE_PHI: | |
1898 | /* If every argument to the PHI produces the same result when | |
1899 | ANDed with the second comparison, we win. | |
1900 | Do not do this unless the type is bool since we need a bool | |
1901 | result here anyway. */ | |
1902 | if (TREE_CODE (TREE_TYPE (op1a)) == BOOLEAN_TYPE) | |
1903 | { | |
1904 | tree result = NULL_TREE; | |
1905 | unsigned i; | |
1906 | for (i = 0; i < gimple_phi_num_args (stmt); i++) | |
1907 | { | |
1908 | tree arg = gimple_phi_arg_def (stmt, i); | |
1909 | ||
1910 | /* If this PHI has itself as an argument, ignore it. | |
1911 | If all the other args produce the same result, | |
1912 | we're still OK. */ | |
1913 | if (arg == gimple_phi_result (stmt)) | |
1914 | continue; | |
1915 | else if (TREE_CODE (arg) == INTEGER_CST) | |
1916 | { | |
1917 | if (invert ? integer_nonzerop (arg) : integer_zerop (arg)) | |
1918 | { | |
1919 | if (!result) | |
1920 | result = boolean_false_node; | |
1921 | else if (!integer_zerop (result)) | |
1922 | return NULL_TREE; | |
1923 | } | |
1924 | else if (!result) | |
1925 | result = fold_build2 (code2, boolean_type_node, | |
1926 | op2a, op2b); | |
1927 | else if (!same_bool_comparison_p (result, | |
1928 | code2, op2a, op2b)) | |
1929 | return NULL_TREE; | |
1930 | } | |
ae4330d7 | 1931 | else if (TREE_CODE (arg) == SSA_NAME |
1932 | && !SSA_NAME_IS_DEFAULT_DEF (arg)) | |
c82d157a | 1933 | { |
8a245b9d | 1934 | tree temp; |
1935 | gimple def_stmt = SSA_NAME_DEF_STMT (arg); | |
1936 | /* In simple cases we can look through PHI nodes, | |
1937 | but we have to be careful with loops. | |
1938 | See PR49073. */ | |
1939 | if (! dom_info_available_p (CDI_DOMINATORS) | |
1940 | || gimple_bb (def_stmt) == gimple_bb (stmt) | |
1941 | || dominated_by_p (CDI_DOMINATORS, | |
1942 | gimple_bb (def_stmt), | |
1943 | gimple_bb (stmt))) | |
1944 | return NULL_TREE; | |
1945 | temp = and_var_with_comparison (arg, invert, code2, | |
1946 | op2a, op2b); | |
c82d157a | 1947 | if (!temp) |
1948 | return NULL_TREE; | |
1949 | else if (!result) | |
1950 | result = temp; | |
1951 | else if (!same_bool_result_p (result, temp)) | |
1952 | return NULL_TREE; | |
1953 | } | |
1954 | else | |
1955 | return NULL_TREE; | |
1956 | } | |
1957 | return result; | |
1958 | } | |
1959 | ||
1960 | default: | |
1961 | break; | |
1962 | } | |
1963 | } | |
1964 | return NULL_TREE; | |
1965 | } | |
1966 | ||
1967 | /* Try to simplify the AND of two comparisons, specified by | |
1968 | (OP1A CODE1 OP1B) and (OP2B CODE2 OP2B), respectively. | |
1969 | If this can be simplified to a single expression (without requiring | |
1970 | introducing more SSA variables to hold intermediate values), | |
1971 | return the resulting tree. Otherwise return NULL_TREE. | |
1972 | If the result expression is non-null, it has boolean type. */ | |
1973 | ||
1974 | tree | |
1975 | maybe_fold_and_comparisons (enum tree_code code1, tree op1a, tree op1b, | |
1976 | enum tree_code code2, tree op2a, tree op2b) | |
1977 | { | |
1978 | tree t = and_comparisons_1 (code1, op1a, op1b, code2, op2a, op2b); | |
1979 | if (t) | |
1980 | return t; | |
1981 | else | |
1982 | return and_comparisons_1 (code2, op2a, op2b, code1, op1a, op1b); | |
1983 | } | |
1984 | ||
1985 | /* Helper function for or_comparisons_1: try to simplify the OR of the | |
1986 | ssa variable VAR with the comparison specified by (OP2A CODE2 OP2B). | |
1987 | If INVERT is true, invert the value of VAR before doing the OR. | |
1988 | Return NULL_EXPR if we can't simplify this to a single expression. */ | |
1989 | ||
1990 | static tree | |
1991 | or_var_with_comparison (tree var, bool invert, | |
1992 | enum tree_code code2, tree op2a, tree op2b) | |
1993 | { | |
1994 | tree t; | |
1995 | gimple stmt = SSA_NAME_DEF_STMT (var); | |
1996 | ||
1997 | /* We can only deal with variables whose definitions are assignments. */ | |
1998 | if (!is_gimple_assign (stmt)) | |
1999 | return NULL_TREE; | |
2000 | ||
2001 | /* If we have an inverted comparison, apply DeMorgan's law and rewrite | |
2002 | !var OR (op2a code2 op2b) => !(var AND !(op2a code2 op2b)) | |
2003 | Then we only have to consider the simpler non-inverted cases. */ | |
2004 | if (invert) | |
2005 | t = and_var_with_comparison_1 (stmt, | |
2006 | invert_tree_comparison (code2, false), | |
2007 | op2a, op2b); | |
2008 | else | |
2009 | t = or_var_with_comparison_1 (stmt, code2, op2a, op2b); | |
2010 | return canonicalize_bool (t, invert); | |
2011 | } | |
2012 | ||
2013 | /* Try to simplify the OR of the ssa variable defined by the assignment | |
2014 | STMT with the comparison specified by (OP2A CODE2 OP2B). | |
2015 | Return NULL_EXPR if we can't simplify this to a single expression. */ | |
2016 | ||
2017 | static tree | |
2018 | or_var_with_comparison_1 (gimple stmt, | |
2019 | enum tree_code code2, tree op2a, tree op2b) | |
2020 | { | |
2021 | tree var = gimple_assign_lhs (stmt); | |
2022 | tree true_test_var = NULL_TREE; | |
2023 | tree false_test_var = NULL_TREE; | |
2024 | enum tree_code innercode = gimple_assign_rhs_code (stmt); | |
2025 | ||
2026 | /* Check for identities like (var OR (var != 0)) => true . */ | |
2027 | if (TREE_CODE (op2a) == SSA_NAME | |
2028 | && TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE) | |
2029 | { | |
2030 | if ((code2 == NE_EXPR && integer_zerop (op2b)) | |
2031 | || (code2 == EQ_EXPR && integer_nonzerop (op2b))) | |
2032 | { | |
2033 | true_test_var = op2a; | |
2034 | if (var == true_test_var) | |
2035 | return var; | |
2036 | } | |
2037 | else if ((code2 == EQ_EXPR && integer_zerop (op2b)) | |
2038 | || (code2 == NE_EXPR && integer_nonzerop (op2b))) | |
2039 | { | |
2040 | false_test_var = op2a; | |
2041 | if (var == false_test_var) | |
2042 | return boolean_true_node; | |
2043 | } | |
2044 | } | |
2045 | ||
2046 | /* If the definition is a comparison, recurse on it. */ | |
2047 | if (TREE_CODE_CLASS (innercode) == tcc_comparison) | |
2048 | { | |
2049 | tree t = or_comparisons_1 (innercode, | |
2050 | gimple_assign_rhs1 (stmt), | |
2051 | gimple_assign_rhs2 (stmt), | |
2052 | code2, | |
2053 | op2a, | |
2054 | op2b); | |
2055 | if (t) | |
2056 | return t; | |
2057 | } | |
2058 | ||
2059 | /* If the definition is an AND or OR expression, we may be able to | |
2060 | simplify by reassociating. */ | |
08410c65 | 2061 | if (TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE |
2062 | && (innercode == BIT_AND_EXPR || innercode == BIT_IOR_EXPR)) | |
c82d157a | 2063 | { |
2064 | tree inner1 = gimple_assign_rhs1 (stmt); | |
2065 | tree inner2 = gimple_assign_rhs2 (stmt); | |
2066 | gimple s; | |
2067 | tree t; | |
2068 | tree partial = NULL_TREE; | |
08410c65 | 2069 | bool is_or = (innercode == BIT_IOR_EXPR); |
c82d157a | 2070 | |
2071 | /* Check for boolean identities that don't require recursive examination | |
2072 | of inner1/inner2: | |
2073 | inner1 OR (inner1 OR inner2) => inner1 OR inner2 => var | |
2074 | inner1 OR (inner1 AND inner2) => inner1 | |
2075 | !inner1 OR (inner1 OR inner2) => true | |
2076 | !inner1 OR (inner1 AND inner2) => !inner1 OR inner2 | |
2077 | */ | |
2078 | if (inner1 == true_test_var) | |
2079 | return (is_or ? var : inner1); | |
2080 | else if (inner2 == true_test_var) | |
2081 | return (is_or ? var : inner2); | |
2082 | else if (inner1 == false_test_var) | |
2083 | return (is_or | |
2084 | ? boolean_true_node | |
2085 | : or_var_with_comparison (inner2, false, code2, op2a, op2b)); | |
2086 | else if (inner2 == false_test_var) | |
2087 | return (is_or | |
2088 | ? boolean_true_node | |
2089 | : or_var_with_comparison (inner1, false, code2, op2a, op2b)); | |
2090 | ||
2091 | /* Next, redistribute/reassociate the OR across the inner tests. | |
2092 | Compute the first partial result, (inner1 OR (op2a code op2b)) */ | |
2093 | if (TREE_CODE (inner1) == SSA_NAME | |
2094 | && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner1)) | |
2095 | && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison | |
2096 | && (t = maybe_fold_or_comparisons (gimple_assign_rhs_code (s), | |
2097 | gimple_assign_rhs1 (s), | |
2098 | gimple_assign_rhs2 (s), | |
2099 | code2, op2a, op2b))) | |
2100 | { | |
2101 | /* Handle the OR case, where we are reassociating: | |
2102 | (inner1 OR inner2) OR (op2a code2 op2b) | |
2103 | => (t OR inner2) | |
2104 | If the partial result t is a constant, we win. Otherwise | |
2105 | continue on to try reassociating with the other inner test. */ | |
ad1e8581 | 2106 | if (is_or) |
c82d157a | 2107 | { |
2108 | if (integer_onep (t)) | |
2109 | return boolean_true_node; | |
2110 | else if (integer_zerop (t)) | |
2111 | return inner2; | |
2112 | } | |
2113 | ||
2114 | /* Handle the AND case, where we are redistributing: | |
2115 | (inner1 AND inner2) OR (op2a code2 op2b) | |
2116 | => (t AND (inner2 OR (op2a code op2b))) */ | |
ad1e8581 | 2117 | else if (integer_zerop (t)) |
2118 | return boolean_false_node; | |
2119 | ||
2120 | /* Save partial result for later. */ | |
2121 | partial = t; | |
c82d157a | 2122 | } |
2123 | ||
2124 | /* Compute the second partial result, (inner2 OR (op2a code op2b)) */ | |
2125 | if (TREE_CODE (inner2) == SSA_NAME | |
2126 | && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner2)) | |
2127 | && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison | |
2128 | && (t = maybe_fold_or_comparisons (gimple_assign_rhs_code (s), | |
2129 | gimple_assign_rhs1 (s), | |
2130 | gimple_assign_rhs2 (s), | |
2131 | code2, op2a, op2b))) | |
2132 | { | |
2133 | /* Handle the OR case, where we are reassociating: | |
2134 | (inner1 OR inner2) OR (op2a code2 op2b) | |
ad1e8581 | 2135 | => (inner1 OR t) |
2136 | => (t OR partial) */ | |
2137 | if (is_or) | |
c82d157a | 2138 | { |
2139 | if (integer_zerop (t)) | |
2140 | return inner1; | |
2141 | else if (integer_onep (t)) | |
2142 | return boolean_true_node; | |
ad1e8581 | 2143 | /* If both are the same, we can apply the identity |
2144 | (x OR x) == x. */ | |
2145 | else if (partial && same_bool_result_p (t, partial)) | |
2146 | return t; | |
c82d157a | 2147 | } |
2148 | ||
2149 | /* Handle the AND case, where we are redistributing: | |
2150 | (inner1 AND inner2) OR (op2a code2 op2b) | |
2151 | => (t AND (inner1 OR (op2a code2 op2b))) | |
2152 | => (t AND partial) */ | |
2153 | else | |
2154 | { | |
2155 | if (integer_zerop (t)) | |
2156 | return boolean_false_node; | |
2157 | else if (partial) | |
2158 | { | |
2159 | /* We already got a simplification for the other | |
2160 | operand to the redistributed AND expression. The | |
2161 | interesting case is when at least one is true. | |
2162 | Or, if both are the same, we can apply the identity | |
ad1e8581 | 2163 | (x AND x) == x. */ |
c82d157a | 2164 | if (integer_onep (partial)) |
2165 | return t; | |
2166 | else if (integer_onep (t)) | |
2167 | return partial; | |
2168 | else if (same_bool_result_p (t, partial)) | |
ad1e8581 | 2169 | return t; |
c82d157a | 2170 | } |
2171 | } | |
2172 | } | |
2173 | } | |
2174 | return NULL_TREE; | |
2175 | } | |
2176 | ||
2177 | /* Try to simplify the OR of two comparisons defined by | |
2178 | (OP1A CODE1 OP1B) and (OP2A CODE2 OP2B), respectively. | |
2179 | If this can be done without constructing an intermediate value, | |
2180 | return the resulting tree; otherwise NULL_TREE is returned. | |
2181 | This function is deliberately asymmetric as it recurses on SSA_DEFs | |
2182 | in the first comparison but not the second. */ | |
2183 | ||
2184 | static tree | |
2185 | or_comparisons_1 (enum tree_code code1, tree op1a, tree op1b, | |
2186 | enum tree_code code2, tree op2a, tree op2b) | |
2187 | { | |
f2c1848b | 2188 | tree truth_type = truth_type_for (TREE_TYPE (op1a)); |
357d8e5d | 2189 | |
c82d157a | 2190 | /* First check for ((x CODE1 y) OR (x CODE2 y)). */ |
2191 | if (operand_equal_p (op1a, op2a, 0) | |
2192 | && operand_equal_p (op1b, op2b, 0)) | |
2193 | { | |
08410c65 | 2194 | /* Result will be either NULL_TREE, or a combined comparison. */ |
c82d157a | 2195 | tree t = combine_comparisons (UNKNOWN_LOCATION, |
2196 | TRUTH_ORIF_EXPR, code1, code2, | |
357d8e5d | 2197 | truth_type, op1a, op1b); |
c82d157a | 2198 | if (t) |
2199 | return t; | |
2200 | } | |
2201 | ||
2202 | /* Likewise the swapped case of the above. */ | |
2203 | if (operand_equal_p (op1a, op2b, 0) | |
2204 | && operand_equal_p (op1b, op2a, 0)) | |
2205 | { | |
08410c65 | 2206 | /* Result will be either NULL_TREE, or a combined comparison. */ |
c82d157a | 2207 | tree t = combine_comparisons (UNKNOWN_LOCATION, |
2208 | TRUTH_ORIF_EXPR, code1, | |
2209 | swap_tree_comparison (code2), | |
357d8e5d | 2210 | truth_type, op1a, op1b); |
c82d157a | 2211 | if (t) |
2212 | return t; | |
2213 | } | |
2214 | ||
2215 | /* If both comparisons are of the same value against constants, we might | |
2216 | be able to merge them. */ | |
2217 | if (operand_equal_p (op1a, op2a, 0) | |
2218 | && TREE_CODE (op1b) == INTEGER_CST | |
2219 | && TREE_CODE (op2b) == INTEGER_CST) | |
2220 | { | |
2221 | int cmp = tree_int_cst_compare (op1b, op2b); | |
2222 | ||
2223 | /* If we have (op1a != op1b), we should either be able to | |
2224 | return that or TRUE, depending on whether the constant op1b | |
2225 | also satisfies the other comparison against op2b. */ | |
2226 | if (code1 == NE_EXPR) | |
2227 | { | |
2228 | bool done = true; | |
2229 | bool val; | |
2230 | switch (code2) | |
2231 | { | |
2232 | case EQ_EXPR: val = (cmp == 0); break; | |
2233 | case NE_EXPR: val = (cmp != 0); break; | |
2234 | case LT_EXPR: val = (cmp < 0); break; | |
2235 | case GT_EXPR: val = (cmp > 0); break; | |
2236 | case LE_EXPR: val = (cmp <= 0); break; | |
2237 | case GE_EXPR: val = (cmp >= 0); break; | |
2238 | default: done = false; | |
2239 | } | |
2240 | if (done) | |
2241 | { | |
2242 | if (val) | |
2243 | return boolean_true_node; | |
2244 | else | |
2245 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2246 | } | |
2247 | } | |
2248 | /* Likewise if the second comparison is a != comparison. */ | |
2249 | else if (code2 == NE_EXPR) | |
2250 | { | |
2251 | bool done = true; | |
2252 | bool val; | |
2253 | switch (code1) | |
2254 | { | |
2255 | case EQ_EXPR: val = (cmp == 0); break; | |
2256 | case NE_EXPR: val = (cmp != 0); break; | |
2257 | case LT_EXPR: val = (cmp > 0); break; | |
2258 | case GT_EXPR: val = (cmp < 0); break; | |
2259 | case LE_EXPR: val = (cmp >= 0); break; | |
2260 | case GE_EXPR: val = (cmp <= 0); break; | |
2261 | default: done = false; | |
2262 | } | |
2263 | if (done) | |
2264 | { | |
2265 | if (val) | |
2266 | return boolean_true_node; | |
2267 | else | |
2268 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2269 | } | |
2270 | } | |
2271 | ||
2272 | /* See if an equality test is redundant with the other comparison. */ | |
2273 | else if (code1 == EQ_EXPR) | |
2274 | { | |
2275 | bool val; | |
2276 | switch (code2) | |
2277 | { | |
2278 | case EQ_EXPR: val = (cmp == 0); break; | |
2279 | case NE_EXPR: val = (cmp != 0); break; | |
2280 | case LT_EXPR: val = (cmp < 0); break; | |
2281 | case GT_EXPR: val = (cmp > 0); break; | |
2282 | case LE_EXPR: val = (cmp <= 0); break; | |
2283 | case GE_EXPR: val = (cmp >= 0); break; | |
2284 | default: | |
2285 | val = false; | |
2286 | } | |
2287 | if (val) | |
2288 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2289 | } | |
2290 | else if (code2 == EQ_EXPR) | |
2291 | { | |
2292 | bool val; | |
2293 | switch (code1) | |
2294 | { | |
2295 | case EQ_EXPR: val = (cmp == 0); break; | |
2296 | case NE_EXPR: val = (cmp != 0); break; | |
2297 | case LT_EXPR: val = (cmp > 0); break; | |
2298 | case GT_EXPR: val = (cmp < 0); break; | |
2299 | case LE_EXPR: val = (cmp >= 0); break; | |
2300 | case GE_EXPR: val = (cmp <= 0); break; | |
2301 | default: | |
2302 | val = false; | |
2303 | } | |
2304 | if (val) | |
2305 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2306 | } | |
2307 | ||
2308 | /* Chose the less restrictive of two < or <= comparisons. */ | |
2309 | else if ((code1 == LT_EXPR || code1 == LE_EXPR) | |
2310 | && (code2 == LT_EXPR || code2 == LE_EXPR)) | |
2311 | { | |
2312 | if ((cmp < 0) || (cmp == 0 && code1 == LT_EXPR)) | |
2313 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2314 | else | |
2315 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2316 | } | |
2317 | ||
2318 | /* Likewise chose the less restrictive of two > or >= comparisons. */ | |
2319 | else if ((code1 == GT_EXPR || code1 == GE_EXPR) | |
2320 | && (code2 == GT_EXPR || code2 == GE_EXPR)) | |
2321 | { | |
2322 | if ((cmp > 0) || (cmp == 0 && code1 == GT_EXPR)) | |
2323 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2324 | else | |
2325 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2326 | } | |
2327 | ||
2328 | /* Check for singleton ranges. */ | |
2329 | else if (cmp == 0 | |
2330 | && ((code1 == LT_EXPR && code2 == GT_EXPR) | |
2331 | || (code1 == GT_EXPR && code2 == LT_EXPR))) | |
2332 | return fold_build2 (NE_EXPR, boolean_type_node, op1a, op2b); | |
2333 | ||
2334 | /* Check for less/greater pairs that don't restrict the range at all. */ | |
2335 | else if (cmp >= 0 | |
2336 | && (code1 == LT_EXPR || code1 == LE_EXPR) | |
2337 | && (code2 == GT_EXPR || code2 == GE_EXPR)) | |
2338 | return boolean_true_node; | |
2339 | else if (cmp <= 0 | |
2340 | && (code1 == GT_EXPR || code1 == GE_EXPR) | |
2341 | && (code2 == LT_EXPR || code2 == LE_EXPR)) | |
2342 | return boolean_true_node; | |
2343 | } | |
2344 | ||
2345 | /* Perhaps the first comparison is (NAME != 0) or (NAME == 1) where | |
2346 | NAME's definition is a truth value. See if there are any simplifications | |
2347 | that can be done against the NAME's definition. */ | |
2348 | if (TREE_CODE (op1a) == SSA_NAME | |
2349 | && (code1 == NE_EXPR || code1 == EQ_EXPR) | |
2350 | && (integer_zerop (op1b) || integer_onep (op1b))) | |
2351 | { | |
2352 | bool invert = ((code1 == EQ_EXPR && integer_zerop (op1b)) | |
2353 | || (code1 == NE_EXPR && integer_onep (op1b))); | |
2354 | gimple stmt = SSA_NAME_DEF_STMT (op1a); | |
2355 | switch (gimple_code (stmt)) | |
2356 | { | |
2357 | case GIMPLE_ASSIGN: | |
2358 | /* Try to simplify by copy-propagating the definition. */ | |
2359 | return or_var_with_comparison (op1a, invert, code2, op2a, op2b); | |
2360 | ||
2361 | case GIMPLE_PHI: | |
2362 | /* If every argument to the PHI produces the same result when | |
2363 | ORed with the second comparison, we win. | |
2364 | Do not do this unless the type is bool since we need a bool | |
2365 | result here anyway. */ | |
2366 | if (TREE_CODE (TREE_TYPE (op1a)) == BOOLEAN_TYPE) | |
2367 | { | |
2368 | tree result = NULL_TREE; | |
2369 | unsigned i; | |
2370 | for (i = 0; i < gimple_phi_num_args (stmt); i++) | |
2371 | { | |
2372 | tree arg = gimple_phi_arg_def (stmt, i); | |
2373 | ||
2374 | /* If this PHI has itself as an argument, ignore it. | |
2375 | If all the other args produce the same result, | |
2376 | we're still OK. */ | |
2377 | if (arg == gimple_phi_result (stmt)) | |
2378 | continue; | |
2379 | else if (TREE_CODE (arg) == INTEGER_CST) | |
2380 | { | |
2381 | if (invert ? integer_zerop (arg) : integer_nonzerop (arg)) | |
2382 | { | |
2383 | if (!result) | |
2384 | result = boolean_true_node; | |
2385 | else if (!integer_onep (result)) | |
2386 | return NULL_TREE; | |
2387 | } | |
2388 | else if (!result) | |
2389 | result = fold_build2 (code2, boolean_type_node, | |
2390 | op2a, op2b); | |
2391 | else if (!same_bool_comparison_p (result, | |
2392 | code2, op2a, op2b)) | |
2393 | return NULL_TREE; | |
2394 | } | |
ae4330d7 | 2395 | else if (TREE_CODE (arg) == SSA_NAME |
2396 | && !SSA_NAME_IS_DEFAULT_DEF (arg)) | |
c82d157a | 2397 | { |
8a245b9d | 2398 | tree temp; |
2399 | gimple def_stmt = SSA_NAME_DEF_STMT (arg); | |
2400 | /* In simple cases we can look through PHI nodes, | |
2401 | but we have to be careful with loops. | |
2402 | See PR49073. */ | |
2403 | if (! dom_info_available_p (CDI_DOMINATORS) | |
2404 | || gimple_bb (def_stmt) == gimple_bb (stmt) | |
2405 | || dominated_by_p (CDI_DOMINATORS, | |
2406 | gimple_bb (def_stmt), | |
2407 | gimple_bb (stmt))) | |
2408 | return NULL_TREE; | |
2409 | temp = or_var_with_comparison (arg, invert, code2, | |
2410 | op2a, op2b); | |
c82d157a | 2411 | if (!temp) |
2412 | return NULL_TREE; | |
2413 | else if (!result) | |
2414 | result = temp; | |
2415 | else if (!same_bool_result_p (result, temp)) | |
2416 | return NULL_TREE; | |
2417 | } | |
2418 | else | |
2419 | return NULL_TREE; | |
2420 | } | |
2421 | return result; | |
2422 | } | |
2423 | ||
2424 | default: | |
2425 | break; | |
2426 | } | |
2427 | } | |
2428 | return NULL_TREE; | |
2429 | } | |
2430 | ||
2431 | /* Try to simplify the OR of two comparisons, specified by | |
2432 | (OP1A CODE1 OP1B) and (OP2B CODE2 OP2B), respectively. | |
2433 | If this can be simplified to a single expression (without requiring | |
2434 | introducing more SSA variables to hold intermediate values), | |
2435 | return the resulting tree. Otherwise return NULL_TREE. | |
2436 | If the result expression is non-null, it has boolean type. */ | |
2437 | ||
2438 | tree | |
2439 | maybe_fold_or_comparisons (enum tree_code code1, tree op1a, tree op1b, | |
2440 | enum tree_code code2, tree op2a, tree op2b) | |
2441 | { | |
2442 | tree t = or_comparisons_1 (code1, op1a, op1b, code2, op2a, op2b); | |
2443 | if (t) | |
2444 | return t; | |
2445 | else | |
2446 | return or_comparisons_1 (code2, op2a, op2b, code1, op1a, op1b); | |
2447 | } | |
1d0b727d | 2448 | |
2449 | ||
2450 | /* Fold STMT to a constant using VALUEIZE to valueize SSA names. | |
2451 | ||
2452 | Either NULL_TREE, a simplified but non-constant or a constant | |
2453 | is returned. | |
2454 | ||
2455 | ??? This should go into a gimple-fold-inline.h file to be eventually | |
2456 | privatized with the single valueize function used in the various TUs | |
2457 | to avoid the indirect function call overhead. */ | |
2458 | ||
2459 | tree | |
2460 | gimple_fold_stmt_to_constant_1 (gimple stmt, tree (*valueize) (tree)) | |
2461 | { | |
2462 | location_t loc = gimple_location (stmt); | |
2463 | switch (gimple_code (stmt)) | |
2464 | { | |
2465 | case GIMPLE_ASSIGN: | |
2466 | { | |
2467 | enum tree_code subcode = gimple_assign_rhs_code (stmt); | |
2468 | ||
2469 | switch (get_gimple_rhs_class (subcode)) | |
2470 | { | |
2471 | case GIMPLE_SINGLE_RHS: | |
2472 | { | |
2473 | tree rhs = gimple_assign_rhs1 (stmt); | |
2474 | enum tree_code_class kind = TREE_CODE_CLASS (subcode); | |
2475 | ||
2476 | if (TREE_CODE (rhs) == SSA_NAME) | |
2477 | { | |
2478 | /* If the RHS is an SSA_NAME, return its known constant value, | |
2479 | if any. */ | |
2480 | return (*valueize) (rhs); | |
2481 | } | |
2482 | /* Handle propagating invariant addresses into address | |
2483 | operations. */ | |
2484 | else if (TREE_CODE (rhs) == ADDR_EXPR | |
2485 | && !is_gimple_min_invariant (rhs)) | |
2486 | { | |
03231f32 | 2487 | HOST_WIDE_INT offset = 0; |
1d0b727d | 2488 | tree base; |
2489 | base = get_addr_base_and_unit_offset_1 (TREE_OPERAND (rhs, 0), | |
2490 | &offset, | |
2491 | valueize); | |
2492 | if (base | |
2493 | && (CONSTANT_CLASS_P (base) | |
2494 | || decl_address_invariant_p (base))) | |
2495 | return build_invariant_address (TREE_TYPE (rhs), | |
2496 | base, offset); | |
2497 | } | |
2498 | else if (TREE_CODE (rhs) == CONSTRUCTOR | |
2499 | && TREE_CODE (TREE_TYPE (rhs)) == VECTOR_TYPE | |
2500 | && (CONSTRUCTOR_NELTS (rhs) | |
2501 | == TYPE_VECTOR_SUBPARTS (TREE_TYPE (rhs)))) | |
2502 | { | |
2503 | unsigned i; | |
fadf62f4 | 2504 | tree val, *vec; |
1d0b727d | 2505 | |
fadf62f4 | 2506 | vec = XALLOCAVEC (tree, |
2507 | TYPE_VECTOR_SUBPARTS (TREE_TYPE (rhs))); | |
1d0b727d | 2508 | FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (rhs), i, val) |
2509 | { | |
2510 | val = (*valueize) (val); | |
2511 | if (TREE_CODE (val) == INTEGER_CST | |
2512 | || TREE_CODE (val) == REAL_CST | |
2513 | || TREE_CODE (val) == FIXED_CST) | |
fadf62f4 | 2514 | vec[i] = val; |
1d0b727d | 2515 | else |
2516 | return NULL_TREE; | |
2517 | } | |
2518 | ||
fadf62f4 | 2519 | return build_vector (TREE_TYPE (rhs), vec); |
1d0b727d | 2520 | } |
2521 | ||
2522 | if (kind == tcc_reference) | |
2523 | { | |
2524 | if ((TREE_CODE (rhs) == VIEW_CONVERT_EXPR | |
2525 | || TREE_CODE (rhs) == REALPART_EXPR | |
2526 | || TREE_CODE (rhs) == IMAGPART_EXPR) | |
2527 | && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME) | |
2528 | { | |
2529 | tree val = (*valueize) (TREE_OPERAND (rhs, 0)); | |
2530 | return fold_unary_loc (EXPR_LOCATION (rhs), | |
2531 | TREE_CODE (rhs), | |
2532 | TREE_TYPE (rhs), val); | |
2533 | } | |
2534 | else if (TREE_CODE (rhs) == BIT_FIELD_REF | |
2535 | && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME) | |
2536 | { | |
2537 | tree val = (*valueize) (TREE_OPERAND (rhs, 0)); | |
2538 | return fold_ternary_loc (EXPR_LOCATION (rhs), | |
2539 | TREE_CODE (rhs), | |
2540 | TREE_TYPE (rhs), val, | |
2541 | TREE_OPERAND (rhs, 1), | |
2542 | TREE_OPERAND (rhs, 2)); | |
2543 | } | |
2544 | else if (TREE_CODE (rhs) == MEM_REF | |
2545 | && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME) | |
2546 | { | |
2547 | tree val = (*valueize) (TREE_OPERAND (rhs, 0)); | |
2548 | if (TREE_CODE (val) == ADDR_EXPR | |
2549 | && is_gimple_min_invariant (val)) | |
2550 | { | |
2551 | tree tem = fold_build2 (MEM_REF, TREE_TYPE (rhs), | |
2552 | unshare_expr (val), | |
2553 | TREE_OPERAND (rhs, 1)); | |
2554 | if (tem) | |
2555 | rhs = tem; | |
2556 | } | |
2557 | } | |
2558 | return fold_const_aggregate_ref_1 (rhs, valueize); | |
2559 | } | |
2560 | else if (kind == tcc_declaration) | |
2561 | return get_symbol_constant_value (rhs); | |
2562 | return rhs; | |
2563 | } | |
2564 | ||
2565 | case GIMPLE_UNARY_RHS: | |
2566 | { | |
2567 | /* Handle unary operators that can appear in GIMPLE form. | |
2568 | Note that we know the single operand must be a constant, | |
2569 | so this should almost always return a simplified RHS. */ | |
704d7315 | 2570 | tree lhs = gimple_assign_lhs (stmt); |
1d0b727d | 2571 | tree op0 = (*valueize) (gimple_assign_rhs1 (stmt)); |
2572 | ||
2573 | /* Conversions are useless for CCP purposes if they are | |
2574 | value-preserving. Thus the restrictions that | |
704d7315 | 2575 | useless_type_conversion_p places for restrict qualification |
2576 | of pointer types should not apply here. | |
2577 | Substitution later will only substitute to allowed places. */ | |
1d0b727d | 2578 | if (CONVERT_EXPR_CODE_P (subcode) |
2579 | && POINTER_TYPE_P (TREE_TYPE (lhs)) | |
704d7315 | 2580 | && POINTER_TYPE_P (TREE_TYPE (op0)) |
9772cb99 | 2581 | && TYPE_ADDR_SPACE (TREE_TYPE (lhs)) |
2582 | == TYPE_ADDR_SPACE (TREE_TYPE (op0)) | |
2583 | && TYPE_MODE (TREE_TYPE (lhs)) | |
2584 | == TYPE_MODE (TREE_TYPE (op0))) | |
704d7315 | 2585 | return op0; |
1d0b727d | 2586 | |
2587 | return | |
2588 | fold_unary_ignore_overflow_loc (loc, subcode, | |
2589 | gimple_expr_type (stmt), op0); | |
2590 | } | |
2591 | ||
2592 | case GIMPLE_BINARY_RHS: | |
2593 | { | |
2594 | /* Handle binary operators that can appear in GIMPLE form. */ | |
2595 | tree op0 = (*valueize) (gimple_assign_rhs1 (stmt)); | |
2596 | tree op1 = (*valueize) (gimple_assign_rhs2 (stmt)); | |
2597 | ||
2598 | /* Translate &x + CST into an invariant form suitable for | |
2599 | further propagation. */ | |
2600 | if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR | |
2601 | && TREE_CODE (op0) == ADDR_EXPR | |
2602 | && TREE_CODE (op1) == INTEGER_CST) | |
2603 | { | |
2604 | tree off = fold_convert (ptr_type_node, op1); | |
3048a5c0 | 2605 | return build_fold_addr_expr_loc |
2606 | (loc, | |
2607 | fold_build2 (MEM_REF, | |
1d0b727d | 2608 | TREE_TYPE (TREE_TYPE (op0)), |
2609 | unshare_expr (op0), off)); | |
2610 | } | |
2611 | ||
2612 | return fold_binary_loc (loc, subcode, | |
2613 | gimple_expr_type (stmt), op0, op1); | |
2614 | } | |
2615 | ||
2616 | case GIMPLE_TERNARY_RHS: | |
2617 | { | |
2618 | /* Handle ternary operators that can appear in GIMPLE form. */ | |
2619 | tree op0 = (*valueize) (gimple_assign_rhs1 (stmt)); | |
2620 | tree op1 = (*valueize) (gimple_assign_rhs2 (stmt)); | |
2621 | tree op2 = (*valueize) (gimple_assign_rhs3 (stmt)); | |
2622 | ||
ce993cc2 | 2623 | /* Fold embedded expressions in ternary codes. */ |
2624 | if ((subcode == COND_EXPR | |
2625 | || subcode == VEC_COND_EXPR) | |
2626 | && COMPARISON_CLASS_P (op0)) | |
2627 | { | |
2628 | tree op00 = (*valueize) (TREE_OPERAND (op0, 0)); | |
2629 | tree op01 = (*valueize) (TREE_OPERAND (op0, 1)); | |
2630 | tree tem = fold_binary_loc (loc, TREE_CODE (op0), | |
2631 | TREE_TYPE (op0), op00, op01); | |
2632 | if (tem) | |
2633 | op0 = tem; | |
2634 | } | |
2635 | ||
1d0b727d | 2636 | return fold_ternary_loc (loc, subcode, |
2637 | gimple_expr_type (stmt), op0, op1, op2); | |
2638 | } | |
2639 | ||
2640 | default: | |
2641 | gcc_unreachable (); | |
2642 | } | |
2643 | } | |
2644 | ||
2645 | case GIMPLE_CALL: | |
2646 | { | |
fb049fba | 2647 | tree fn; |
2648 | ||
2649 | if (gimple_call_internal_p (stmt)) | |
2650 | /* No folding yet for these functions. */ | |
2651 | return NULL_TREE; | |
2652 | ||
2653 | fn = (*valueize) (gimple_call_fn (stmt)); | |
1d0b727d | 2654 | if (TREE_CODE (fn) == ADDR_EXPR |
2655 | && TREE_CODE (TREE_OPERAND (fn, 0)) == FUNCTION_DECL | |
2656 | && DECL_BUILT_IN (TREE_OPERAND (fn, 0))) | |
2657 | { | |
2658 | tree *args = XALLOCAVEC (tree, gimple_call_num_args (stmt)); | |
2659 | tree call, retval; | |
2660 | unsigned i; | |
2661 | for (i = 0; i < gimple_call_num_args (stmt); ++i) | |
2662 | args[i] = (*valueize) (gimple_call_arg (stmt, i)); | |
2663 | call = build_call_array_loc (loc, | |
2664 | gimple_call_return_type (stmt), | |
2665 | fn, gimple_call_num_args (stmt), args); | |
2666 | retval = fold_call_expr (EXPR_LOCATION (call), call, false); | |
2667 | if (retval) | |
2668 | /* fold_call_expr wraps the result inside a NOP_EXPR. */ | |
2669 | STRIP_NOPS (retval); | |
2670 | return retval; | |
2671 | } | |
2672 | return NULL_TREE; | |
2673 | } | |
2674 | ||
2675 | default: | |
2676 | return NULL_TREE; | |
2677 | } | |
2678 | } | |
2679 | ||
2680 | /* Fold STMT to a constant using VALUEIZE to valueize SSA names. | |
2681 | Returns NULL_TREE if folding to a constant is not possible, otherwise | |
2682 | returns a constant according to is_gimple_min_invariant. */ | |
2683 | ||
2684 | tree | |
2685 | gimple_fold_stmt_to_constant (gimple stmt, tree (*valueize) (tree)) | |
2686 | { | |
2687 | tree res = gimple_fold_stmt_to_constant_1 (stmt, valueize); | |
2688 | if (res && is_gimple_min_invariant (res)) | |
2689 | return res; | |
2690 | return NULL_TREE; | |
2691 | } | |
2692 | ||
2693 | ||
2694 | /* The following set of functions are supposed to fold references using | |
2695 | their constant initializers. */ | |
2696 | ||
2697 | static tree fold_ctor_reference (tree type, tree ctor, | |
2698 | unsigned HOST_WIDE_INT offset, | |
a65b88bf | 2699 | unsigned HOST_WIDE_INT size, tree); |
1d0b727d | 2700 | |
2701 | /* See if we can find constructor defining value of BASE. | |
2702 | When we know the consructor with constant offset (such as | |
2703 | base is array[40] and we do know constructor of array), then | |
2704 | BIT_OFFSET is adjusted accordingly. | |
2705 | ||
2706 | As a special case, return error_mark_node when constructor | |
2707 | is not explicitly available, but it is known to be zero | |
2708 | such as 'static const int a;'. */ | |
2709 | static tree | |
2710 | get_base_constructor (tree base, HOST_WIDE_INT *bit_offset, | |
2711 | tree (*valueize)(tree)) | |
2712 | { | |
2713 | HOST_WIDE_INT bit_offset2, size, max_size; | |
2714 | if (TREE_CODE (base) == MEM_REF) | |
2715 | { | |
2716 | if (!integer_zerop (TREE_OPERAND (base, 1))) | |
2717 | { | |
2718 | if (!host_integerp (TREE_OPERAND (base, 1), 0)) | |
2719 | return NULL_TREE; | |
2720 | *bit_offset += (mem_ref_offset (base).low | |
2721 | * BITS_PER_UNIT); | |
2722 | } | |
2723 | ||
2724 | if (valueize | |
2725 | && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME) | |
2726 | base = valueize (TREE_OPERAND (base, 0)); | |
2727 | if (!base || TREE_CODE (base) != ADDR_EXPR) | |
2728 | return NULL_TREE; | |
2729 | base = TREE_OPERAND (base, 0); | |
2730 | } | |
2731 | ||
2732 | /* Get a CONSTRUCTOR. If BASE is a VAR_DECL, get its | |
2733 | DECL_INITIAL. If BASE is a nested reference into another | |
2734 | ARRAY_REF or COMPONENT_REF, make a recursive call to resolve | |
2735 | the inner reference. */ | |
2736 | switch (TREE_CODE (base)) | |
2737 | { | |
2738 | case VAR_DECL: | |
1d0b727d | 2739 | case CONST_DECL: |
df8d3e89 | 2740 | { |
2741 | tree init = ctor_for_folding (base); | |
2742 | ||
a04e8d62 | 2743 | /* Our semantic is exact opposite of ctor_for_folding; |
df8d3e89 | 2744 | NULL means unknown, while error_mark_node is 0. */ |
2745 | if (init == error_mark_node) | |
2746 | return NULL_TREE; | |
2747 | if (!init) | |
2748 | return error_mark_node; | |
2749 | return init; | |
2750 | } | |
1d0b727d | 2751 | |
2752 | case ARRAY_REF: | |
2753 | case COMPONENT_REF: | |
2754 | base = get_ref_base_and_extent (base, &bit_offset2, &size, &max_size); | |
2755 | if (max_size == -1 || size != max_size) | |
2756 | return NULL_TREE; | |
2757 | *bit_offset += bit_offset2; | |
2758 | return get_base_constructor (base, bit_offset, valueize); | |
2759 | ||
2760 | case STRING_CST: | |
2761 | case CONSTRUCTOR: | |
2762 | return base; | |
2763 | ||
2764 | default: | |
2765 | return NULL_TREE; | |
2766 | } | |
2767 | } | |
2768 | ||
2769 | /* CTOR is STRING_CST. Fold reference of type TYPE and size SIZE | |
2770 | to the memory at bit OFFSET. | |
2771 | ||
2772 | We do only simple job of folding byte accesses. */ | |
2773 | ||
2774 | static tree | |
2775 | fold_string_cst_ctor_reference (tree type, tree ctor, | |
2776 | unsigned HOST_WIDE_INT offset, | |
2777 | unsigned HOST_WIDE_INT size) | |
2778 | { | |
2779 | if (INTEGRAL_TYPE_P (type) | |
2780 | && (TYPE_MODE (type) | |
2781 | == TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) | |
2782 | && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) | |
2783 | == MODE_INT) | |
2784 | && GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) == 1 | |
2785 | && size == BITS_PER_UNIT | |
2786 | && !(offset % BITS_PER_UNIT)) | |
2787 | { | |
2788 | offset /= BITS_PER_UNIT; | |
2789 | if (offset < (unsigned HOST_WIDE_INT) TREE_STRING_LENGTH (ctor)) | |
2790 | return build_int_cst_type (type, (TREE_STRING_POINTER (ctor) | |
2791 | [offset])); | |
2792 | /* Folding | |
2793 | const char a[20]="hello"; | |
2794 | return a[10]; | |
2795 | ||
2796 | might lead to offset greater than string length. In this case we | |
2797 | know value is either initialized to 0 or out of bounds. Return 0 | |
2798 | in both cases. */ | |
2799 | return build_zero_cst (type); | |
2800 | } | |
2801 | return NULL_TREE; | |
2802 | } | |
2803 | ||
2804 | /* CTOR is CONSTRUCTOR of an array type. Fold reference of type TYPE and size | |
2805 | SIZE to the memory at bit OFFSET. */ | |
2806 | ||
2807 | static tree | |
2808 | fold_array_ctor_reference (tree type, tree ctor, | |
2809 | unsigned HOST_WIDE_INT offset, | |
a65b88bf | 2810 | unsigned HOST_WIDE_INT size, |
2811 | tree from_decl) | |
1d0b727d | 2812 | { |
2813 | unsigned HOST_WIDE_INT cnt; | |
2814 | tree cfield, cval; | |
2815 | double_int low_bound, elt_size; | |
2816 | double_int index, max_index; | |
2817 | double_int access_index; | |
96c3acd0 | 2818 | tree domain_type = NULL_TREE, index_type = NULL_TREE; |
1d0b727d | 2819 | HOST_WIDE_INT inner_offset; |
2820 | ||
2821 | /* Compute low bound and elt size. */ | |
415b0903 | 2822 | if (TREE_CODE (TREE_TYPE (ctor)) == ARRAY_TYPE) |
2823 | domain_type = TYPE_DOMAIN (TREE_TYPE (ctor)); | |
1d0b727d | 2824 | if (domain_type && TYPE_MIN_VALUE (domain_type)) |
2825 | { | |
2826 | /* Static constructors for variably sized objects makes no sense. */ | |
2827 | gcc_assert (TREE_CODE (TYPE_MIN_VALUE (domain_type)) == INTEGER_CST); | |
96c3acd0 | 2828 | index_type = TREE_TYPE (TYPE_MIN_VALUE (domain_type)); |
1d0b727d | 2829 | low_bound = tree_to_double_int (TYPE_MIN_VALUE (domain_type)); |
2830 | } | |
2831 | else | |
2832 | low_bound = double_int_zero; | |
2833 | /* Static constructors for variably sized objects makes no sense. */ | |
9af5ce0c | 2834 | gcc_assert (TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (ctor)))) |
1d0b727d | 2835 | == INTEGER_CST); |
2836 | elt_size = | |
2837 | tree_to_double_int (TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (ctor)))); | |
2838 | ||
2839 | ||
2840 | /* We can handle only constantly sized accesses that are known to not | |
2841 | be larger than size of array element. */ | |
2842 | if (!TYPE_SIZE_UNIT (type) | |
2843 | || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST | |
cf8f0e63 | 2844 | || elt_size.slt (tree_to_double_int (TYPE_SIZE_UNIT (type)))) |
1d0b727d | 2845 | return NULL_TREE; |
2846 | ||
2847 | /* Compute the array index we look for. */ | |
cf8f0e63 | 2848 | access_index = double_int::from_uhwi (offset / BITS_PER_UNIT) |
2849 | .udiv (elt_size, TRUNC_DIV_EXPR); | |
2850 | access_index += low_bound; | |
96c3acd0 | 2851 | if (index_type) |
cf8f0e63 | 2852 | access_index = access_index.ext (TYPE_PRECISION (index_type), |
2853 | TYPE_UNSIGNED (index_type)); | |
1d0b727d | 2854 | |
2855 | /* And offset within the access. */ | |
cf8f0e63 | 2856 | inner_offset = offset % (elt_size.to_uhwi () * BITS_PER_UNIT); |
1d0b727d | 2857 | |
2858 | /* See if the array field is large enough to span whole access. We do not | |
2859 | care to fold accesses spanning multiple array indexes. */ | |
cf8f0e63 | 2860 | if (inner_offset + size > elt_size.to_uhwi () * BITS_PER_UNIT) |
1d0b727d | 2861 | return NULL_TREE; |
2862 | ||
cf8f0e63 | 2863 | index = low_bound - double_int_one; |
96c3acd0 | 2864 | if (index_type) |
cf8f0e63 | 2865 | index = index.ext (TYPE_PRECISION (index_type), TYPE_UNSIGNED (index_type)); |
96c3acd0 | 2866 | |
1d0b727d | 2867 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, cval) |
2868 | { | |
2869 | /* Array constructor might explicitely set index, or specify range | |
2870 | or leave index NULL meaning that it is next index after previous | |
2871 | one. */ | |
2872 | if (cfield) | |
2873 | { | |
2874 | if (TREE_CODE (cfield) == INTEGER_CST) | |
2875 | max_index = index = tree_to_double_int (cfield); | |
2876 | else | |
2877 | { | |
2878 | gcc_assert (TREE_CODE (cfield) == RANGE_EXPR); | |
2879 | index = tree_to_double_int (TREE_OPERAND (cfield, 0)); | |
2880 | max_index = tree_to_double_int (TREE_OPERAND (cfield, 1)); | |
2881 | } | |
2882 | } | |
2883 | else | |
96c3acd0 | 2884 | { |
cf8f0e63 | 2885 | index += double_int_one; |
96c3acd0 | 2886 | if (index_type) |
cf8f0e63 | 2887 | index = index.ext (TYPE_PRECISION (index_type), |
2888 | TYPE_UNSIGNED (index_type)); | |
96c3acd0 | 2889 | max_index = index; |
2890 | } | |
1d0b727d | 2891 | |
2892 | /* Do we have match? */ | |
cf8f0e63 | 2893 | if (access_index.cmp (index, 1) >= 0 |
2894 | && access_index.cmp (max_index, 1) <= 0) | |
a65b88bf | 2895 | return fold_ctor_reference (type, cval, inner_offset, size, |
2896 | from_decl); | |
1d0b727d | 2897 | } |
2898 | /* When memory is not explicitely mentioned in constructor, | |
2899 | it is 0 (or out of range). */ | |
2900 | return build_zero_cst (type); | |
2901 | } | |
2902 | ||
2903 | /* CTOR is CONSTRUCTOR of an aggregate or vector. | |
2904 | Fold reference of type TYPE and size SIZE to the memory at bit OFFSET. */ | |
2905 | ||
2906 | static tree | |
2907 | fold_nonarray_ctor_reference (tree type, tree ctor, | |
2908 | unsigned HOST_WIDE_INT offset, | |
a65b88bf | 2909 | unsigned HOST_WIDE_INT size, |
2910 | tree from_decl) | |
1d0b727d | 2911 | { |
2912 | unsigned HOST_WIDE_INT cnt; | |
2913 | tree cfield, cval; | |
2914 | ||
2915 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, | |
2916 | cval) | |
2917 | { | |
2918 | tree byte_offset = DECL_FIELD_OFFSET (cfield); | |
2919 | tree field_offset = DECL_FIELD_BIT_OFFSET (cfield); | |
2920 | tree field_size = DECL_SIZE (cfield); | |
2921 | double_int bitoffset; | |
2922 | double_int byte_offset_cst = tree_to_double_int (byte_offset); | |
cf8f0e63 | 2923 | double_int bits_per_unit_cst = double_int::from_uhwi (BITS_PER_UNIT); |
40a19864 | 2924 | double_int bitoffset_end, access_end; |
1d0b727d | 2925 | |
2926 | /* Variable sized objects in static constructors makes no sense, | |
2927 | but field_size can be NULL for flexible array members. */ | |
2928 | gcc_assert (TREE_CODE (field_offset) == INTEGER_CST | |
2929 | && TREE_CODE (byte_offset) == INTEGER_CST | |
2930 | && (field_size != NULL_TREE | |
2931 | ? TREE_CODE (field_size) == INTEGER_CST | |
2932 | : TREE_CODE (TREE_TYPE (cfield)) == ARRAY_TYPE)); | |
2933 | ||
2934 | /* Compute bit offset of the field. */ | |
cf8f0e63 | 2935 | bitoffset = tree_to_double_int (field_offset) |
2936 | + byte_offset_cst * bits_per_unit_cst; | |
1d0b727d | 2937 | /* Compute bit offset where the field ends. */ |
2938 | if (field_size != NULL_TREE) | |
cf8f0e63 | 2939 | bitoffset_end = bitoffset + tree_to_double_int (field_size); |
1d0b727d | 2940 | else |
2941 | bitoffset_end = double_int_zero; | |
2942 | ||
cf8f0e63 | 2943 | access_end = double_int::from_uhwi (offset) |
2944 | + double_int::from_uhwi (size); | |
40a19864 | 2945 | |
2946 | /* Is there any overlap between [OFFSET, OFFSET+SIZE) and | |
2947 | [BITOFFSET, BITOFFSET_END)? */ | |
cf8f0e63 | 2948 | if (access_end.cmp (bitoffset, 0) > 0 |
1d0b727d | 2949 | && (field_size == NULL_TREE |
cf8f0e63 | 2950 | || double_int::from_uhwi (offset).slt (bitoffset_end))) |
1d0b727d | 2951 | { |
cf8f0e63 | 2952 | double_int inner_offset = double_int::from_uhwi (offset) - bitoffset; |
1d0b727d | 2953 | /* We do have overlap. Now see if field is large enough to |
2954 | cover the access. Give up for accesses spanning multiple | |
2955 | fields. */ | |
cf8f0e63 | 2956 | if (access_end.cmp (bitoffset_end, 0) > 0) |
1d0b727d | 2957 | return NULL_TREE; |
cf8f0e63 | 2958 | if (double_int::from_uhwi (offset).slt (bitoffset)) |
40a19864 | 2959 | return NULL_TREE; |
1d0b727d | 2960 | return fold_ctor_reference (type, cval, |
cf8f0e63 | 2961 | inner_offset.to_uhwi (), size, |
a65b88bf | 2962 | from_decl); |
1d0b727d | 2963 | } |
2964 | } | |
2965 | /* When memory is not explicitely mentioned in constructor, it is 0. */ | |
2966 | return build_zero_cst (type); | |
2967 | } | |
2968 | ||
2969 | /* CTOR is value initializing memory, fold reference of type TYPE and size SIZE | |
2970 | to the memory at bit OFFSET. */ | |
2971 | ||
2972 | static tree | |
2973 | fold_ctor_reference (tree type, tree ctor, unsigned HOST_WIDE_INT offset, | |
a65b88bf | 2974 | unsigned HOST_WIDE_INT size, tree from_decl) |
1d0b727d | 2975 | { |
2976 | tree ret; | |
2977 | ||
2978 | /* We found the field with exact match. */ | |
2979 | if (useless_type_conversion_p (type, TREE_TYPE (ctor)) | |
2980 | && !offset) | |
8f266cd9 | 2981 | return canonicalize_constructor_val (unshare_expr (ctor), from_decl); |
1d0b727d | 2982 | |
2983 | /* We are at the end of walk, see if we can view convert the | |
2984 | result. */ | |
2985 | if (!AGGREGATE_TYPE_P (TREE_TYPE (ctor)) && !offset | |
2986 | /* VIEW_CONVERT_EXPR is defined only for matching sizes. */ | |
2987 | && operand_equal_p (TYPE_SIZE (type), | |
2988 | TYPE_SIZE (TREE_TYPE (ctor)), 0)) | |
2989 | { | |
8f266cd9 | 2990 | ret = canonicalize_constructor_val (unshare_expr (ctor), from_decl); |
1d0b727d | 2991 | ret = fold_unary (VIEW_CONVERT_EXPR, type, ret); |
2992 | if (ret) | |
2993 | STRIP_NOPS (ret); | |
2994 | return ret; | |
2995 | } | |
2996 | if (TREE_CODE (ctor) == STRING_CST) | |
2997 | return fold_string_cst_ctor_reference (type, ctor, offset, size); | |
2998 | if (TREE_CODE (ctor) == CONSTRUCTOR) | |
2999 | { | |
3000 | ||
415b0903 | 3001 | if (TREE_CODE (TREE_TYPE (ctor)) == ARRAY_TYPE |
3002 | || TREE_CODE (TREE_TYPE (ctor)) == VECTOR_TYPE) | |
a65b88bf | 3003 | return fold_array_ctor_reference (type, ctor, offset, size, |
3004 | from_decl); | |
1d0b727d | 3005 | else |
a65b88bf | 3006 | return fold_nonarray_ctor_reference (type, ctor, offset, size, |
3007 | from_decl); | |
1d0b727d | 3008 | } |
3009 | ||
3010 | return NULL_TREE; | |
3011 | } | |
3012 | ||
3013 | /* Return the tree representing the element referenced by T if T is an | |
3014 | ARRAY_REF or COMPONENT_REF into constant aggregates valuezing SSA | |
3015 | names using VALUEIZE. Return NULL_TREE otherwise. */ | |
3016 | ||
3017 | tree | |
3018 | fold_const_aggregate_ref_1 (tree t, tree (*valueize) (tree)) | |
3019 | { | |
3020 | tree ctor, idx, base; | |
3021 | HOST_WIDE_INT offset, size, max_size; | |
3022 | tree tem; | |
3023 | ||
62df0ff9 | 3024 | if (TREE_THIS_VOLATILE (t)) |
3025 | return NULL_TREE; | |
3026 | ||
1d0b727d | 3027 | if (TREE_CODE_CLASS (TREE_CODE (t)) == tcc_declaration) |
3028 | return get_symbol_constant_value (t); | |
3029 | ||
3030 | tem = fold_read_from_constant_string (t); | |
3031 | if (tem) | |
3032 | return tem; | |
3033 | ||
3034 | switch (TREE_CODE (t)) | |
3035 | { | |
3036 | case ARRAY_REF: | |
3037 | case ARRAY_RANGE_REF: | |
3038 | /* Constant indexes are handled well by get_base_constructor. | |
3039 | Only special case variable offsets. | |
3040 | FIXME: This code can't handle nested references with variable indexes | |
3041 | (they will be handled only by iteration of ccp). Perhaps we can bring | |
3042 | get_ref_base_and_extent here and make it use a valueize callback. */ | |
3043 | if (TREE_CODE (TREE_OPERAND (t, 1)) == SSA_NAME | |
3044 | && valueize | |
3045 | && (idx = (*valueize) (TREE_OPERAND (t, 1))) | |
96c3acd0 | 3046 | && TREE_CODE (idx) == INTEGER_CST) |
1d0b727d | 3047 | { |
3048 | tree low_bound, unit_size; | |
96c3acd0 | 3049 | double_int doffset; |
1d0b727d | 3050 | |
3051 | /* If the resulting bit-offset is constant, track it. */ | |
3052 | if ((low_bound = array_ref_low_bound (t), | |
96c3acd0 | 3053 | TREE_CODE (low_bound) == INTEGER_CST) |
1d0b727d | 3054 | && (unit_size = array_ref_element_size (t), |
96c3acd0 | 3055 | host_integerp (unit_size, 1)) |
cf8f0e63 | 3056 | && (doffset = (TREE_INT_CST (idx) - TREE_INT_CST (low_bound)) |
3057 | .sext (TYPE_PRECISION (TREE_TYPE (idx))), | |
3058 | doffset.fits_shwi ())) | |
1d0b727d | 3059 | { |
cf8f0e63 | 3060 | offset = doffset.to_shwi (); |
1d0b727d | 3061 | offset *= TREE_INT_CST_LOW (unit_size); |
3062 | offset *= BITS_PER_UNIT; | |
3063 | ||
3064 | base = TREE_OPERAND (t, 0); | |
3065 | ctor = get_base_constructor (base, &offset, valueize); | |
3066 | /* Empty constructor. Always fold to 0. */ | |
3067 | if (ctor == error_mark_node) | |
3068 | return build_zero_cst (TREE_TYPE (t)); | |
3069 | /* Out of bound array access. Value is undefined, | |
3070 | but don't fold. */ | |
3071 | if (offset < 0) | |
3072 | return NULL_TREE; | |
3073 | /* We can not determine ctor. */ | |
3074 | if (!ctor) | |
3075 | return NULL_TREE; | |
3076 | return fold_ctor_reference (TREE_TYPE (t), ctor, offset, | |
3077 | TREE_INT_CST_LOW (unit_size) | |
a65b88bf | 3078 | * BITS_PER_UNIT, |
3079 | base); | |
1d0b727d | 3080 | } |
3081 | } | |
3082 | /* Fallthru. */ | |
3083 | ||
3084 | case COMPONENT_REF: | |
3085 | case BIT_FIELD_REF: | |
3086 | case TARGET_MEM_REF: | |
3087 | case MEM_REF: | |
3088 | base = get_ref_base_and_extent (t, &offset, &size, &max_size); | |
3089 | ctor = get_base_constructor (base, &offset, valueize); | |
3090 | ||
3091 | /* Empty constructor. Always fold to 0. */ | |
3092 | if (ctor == error_mark_node) | |
3093 | return build_zero_cst (TREE_TYPE (t)); | |
3094 | /* We do not know precise address. */ | |
3095 | if (max_size == -1 || max_size != size) | |
3096 | return NULL_TREE; | |
3097 | /* We can not determine ctor. */ | |
3098 | if (!ctor) | |
3099 | return NULL_TREE; | |
3100 | ||
3101 | /* Out of bound array access. Value is undefined, but don't fold. */ | |
3102 | if (offset < 0) | |
3103 | return NULL_TREE; | |
3104 | ||
a65b88bf | 3105 | return fold_ctor_reference (TREE_TYPE (t), ctor, offset, size, |
3106 | base); | |
1d0b727d | 3107 | |
3108 | case REALPART_EXPR: | |
3109 | case IMAGPART_EXPR: | |
3110 | { | |
3111 | tree c = fold_const_aggregate_ref_1 (TREE_OPERAND (t, 0), valueize); | |
3112 | if (c && TREE_CODE (c) == COMPLEX_CST) | |
3113 | return fold_build1_loc (EXPR_LOCATION (t), | |
3114 | TREE_CODE (t), TREE_TYPE (t), c); | |
3115 | break; | |
3116 | } | |
3117 | ||
3118 | default: | |
3119 | break; | |
3120 | } | |
3121 | ||
3122 | return NULL_TREE; | |
3123 | } | |
3124 | ||
3125 | tree | |
3126 | fold_const_aggregate_ref (tree t) | |
3127 | { | |
3128 | return fold_const_aggregate_ref_1 (t, NULL); | |
3129 | } | |
0b7ad900 | 3130 | |
d4e80e2b | 3131 | /* Return a declaration of a function which an OBJ_TYPE_REF references. TOKEN |
3132 | is integer form of OBJ_TYPE_REF_TOKEN of the reference expression. | |
3133 | KNOWN_BINFO carries the binfo describing the true type of | |
3134 | OBJ_TYPE_REF_OBJECT(REF). */ | |
3135 | ||
3136 | tree | |
3137 | gimple_get_virt_method_for_binfo (HOST_WIDE_INT token, tree known_binfo) | |
3138 | { | |
3139 | unsigned HOST_WIDE_INT offset, size; | |
9b3e908f | 3140 | tree v, fn, vtable, init; |
d4e80e2b | 3141 | |
a65b88bf | 3142 | vtable = v = BINFO_VTABLE (known_binfo); |
d4e80e2b | 3143 | /* If there is no virtual methods table, leave the OBJ_TYPE_REF alone. */ |
3144 | if (!v) | |
3145 | return NULL_TREE; | |
3146 | ||
3147 | if (TREE_CODE (v) == POINTER_PLUS_EXPR) | |
3148 | { | |
3149 | offset = tree_low_cst (TREE_OPERAND (v, 1), 1) * BITS_PER_UNIT; | |
3150 | v = TREE_OPERAND (v, 0); | |
3151 | } | |
3152 | else | |
3153 | offset = 0; | |
3154 | ||
3155 | if (TREE_CODE (v) != ADDR_EXPR) | |
3156 | return NULL_TREE; | |
3157 | v = TREE_OPERAND (v, 0); | |
3158 | ||
3159 | if (TREE_CODE (v) != VAR_DECL | |
9b3e908f | 3160 | || !DECL_VIRTUAL_P (v)) |
d4e80e2b | 3161 | return NULL_TREE; |
9b3e908f | 3162 | init = ctor_for_folding (v); |
3163 | ||
3164 | /* The virtual tables should always be born with constructors. | |
3165 | and we always should assume that they are avaialble for | |
3166 | folding. At the moment we do not stream them in all cases, | |
3167 | but it should never happen that ctor seem unreachable. */ | |
3168 | gcc_assert (init); | |
3169 | if (init == error_mark_node) | |
3170 | { | |
3171 | gcc_assert (in_lto_p); | |
3172 | return NULL_TREE; | |
3173 | } | |
d4e80e2b | 3174 | gcc_checking_assert (TREE_CODE (TREE_TYPE (v)) == ARRAY_TYPE); |
3175 | size = tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (v))), 1); | |
3176 | offset += token * size; | |
9b3e908f | 3177 | fn = fold_ctor_reference (TREE_TYPE (TREE_TYPE (v)), init, |
887481a3 | 3178 | offset, size, v); |
86d2a13e | 3179 | if (!fn || integer_zerop (fn)) |
d4e80e2b | 3180 | return NULL_TREE; |
3181 | gcc_assert (TREE_CODE (fn) == ADDR_EXPR | |
3182 | || TREE_CODE (fn) == FDESC_EXPR); | |
3183 | fn = TREE_OPERAND (fn, 0); | |
3184 | gcc_assert (TREE_CODE (fn) == FUNCTION_DECL); | |
3185 | ||
3186 | /* When cgraph node is missing and function is not public, we cannot | |
3187 | devirtualize. This can happen in WHOPR when the actual method | |
3188 | ends up in other partition, because we found devirtualization | |
3189 | possibility too late. */ | |
a65b88bf | 3190 | if (!can_refer_decl_in_current_unit_p (fn, vtable)) |
d4e80e2b | 3191 | return NULL_TREE; |
3192 | ||
e25d4891 | 3193 | /* Make sure we create a cgraph node for functions we'll reference. |
3194 | They can be non-existent if the reference comes from an entry | |
3195 | of an external vtable for example. */ | |
3196 | cgraph_get_create_node (fn); | |
3197 | ||
d4e80e2b | 3198 | return fn; |
3199 | } | |
3200 | ||
0b7ad900 | 3201 | /* Return true iff VAL is a gimple expression that is known to be |
3202 | non-negative. Restricted to floating-point inputs. */ | |
3203 | ||
3204 | bool | |
3205 | gimple_val_nonnegative_real_p (tree val) | |
3206 | { | |
3207 | gimple def_stmt; | |
3208 | ||
3209 | gcc_assert (val && SCALAR_FLOAT_TYPE_P (TREE_TYPE (val))); | |
3210 | ||
3211 | /* Use existing logic for non-gimple trees. */ | |
3212 | if (tree_expr_nonnegative_p (val)) | |
3213 | return true; | |
3214 | ||
3215 | if (TREE_CODE (val) != SSA_NAME) | |
3216 | return false; | |
3217 | ||
3218 | /* Currently we look only at the immediately defining statement | |
3219 | to make this determination, since recursion on defining | |
3220 | statements of operands can lead to quadratic behavior in the | |
3221 | worst case. This is expected to catch almost all occurrences | |
3222 | in practice. It would be possible to implement limited-depth | |
3223 | recursion if important cases are lost. Alternatively, passes | |
3224 | that need this information (such as the pow/powi lowering code | |
3225 | in the cse_sincos pass) could be revised to provide it through | |
3226 | dataflow propagation. */ | |
3227 | ||
3228 | def_stmt = SSA_NAME_DEF_STMT (val); | |
3229 | ||
3230 | if (is_gimple_assign (def_stmt)) | |
3231 | { | |
3232 | tree op0, op1; | |
3233 | ||
3234 | /* See fold-const.c:tree_expr_nonnegative_p for additional | |
3235 | cases that could be handled with recursion. */ | |
3236 | ||
3237 | switch (gimple_assign_rhs_code (def_stmt)) | |
3238 | { | |
3239 | case ABS_EXPR: | |
3240 | /* Always true for floating-point operands. */ | |
3241 | return true; | |
3242 | ||
3243 | case MULT_EXPR: | |
3244 | /* True if the two operands are identical (since we are | |
3245 | restricted to floating-point inputs). */ | |
3246 | op0 = gimple_assign_rhs1 (def_stmt); | |
3247 | op1 = gimple_assign_rhs2 (def_stmt); | |
3248 | ||
3249 | if (op0 == op1 | |
3250 | || operand_equal_p (op0, op1, 0)) | |
3251 | return true; | |
3252 | ||
3253 | default: | |
3254 | return false; | |
3255 | } | |
3256 | } | |
3257 | else if (is_gimple_call (def_stmt)) | |
3258 | { | |
3259 | tree fndecl = gimple_call_fndecl (def_stmt); | |
3260 | if (fndecl | |
3261 | && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL) | |
3262 | { | |
3263 | tree arg1; | |
3264 | ||
3265 | switch (DECL_FUNCTION_CODE (fndecl)) | |
3266 | { | |
3267 | CASE_FLT_FN (BUILT_IN_ACOS): | |
3268 | CASE_FLT_FN (BUILT_IN_ACOSH): | |
3269 | CASE_FLT_FN (BUILT_IN_CABS): | |
3270 | CASE_FLT_FN (BUILT_IN_COSH): | |
3271 | CASE_FLT_FN (BUILT_IN_ERFC): | |
3272 | CASE_FLT_FN (BUILT_IN_EXP): | |
3273 | CASE_FLT_FN (BUILT_IN_EXP10): | |
3274 | CASE_FLT_FN (BUILT_IN_EXP2): | |
3275 | CASE_FLT_FN (BUILT_IN_FABS): | |
3276 | CASE_FLT_FN (BUILT_IN_FDIM): | |
3277 | CASE_FLT_FN (BUILT_IN_HYPOT): | |
3278 | CASE_FLT_FN (BUILT_IN_POW10): | |
3279 | return true; | |
3280 | ||
3281 | CASE_FLT_FN (BUILT_IN_SQRT): | |
3282 | /* sqrt(-0.0) is -0.0, and sqrt is not defined over other | |
3283 | nonnegative inputs. */ | |
3284 | if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (val)))) | |
3285 | return true; | |
3286 | ||
3287 | break; | |
3288 | ||
3289 | CASE_FLT_FN (BUILT_IN_POWI): | |
3290 | /* True if the second argument is an even integer. */ | |
3291 | arg1 = gimple_call_arg (def_stmt, 1); | |
3292 | ||
3293 | if (TREE_CODE (arg1) == INTEGER_CST | |
3294 | && (TREE_INT_CST_LOW (arg1) & 1) == 0) | |
3295 | return true; | |
3296 | ||
3297 | break; | |
3298 | ||
3299 | CASE_FLT_FN (BUILT_IN_POW): | |
3300 | /* True if the second argument is an even integer-valued | |
3301 | real. */ | |
3302 | arg1 = gimple_call_arg (def_stmt, 1); | |
3303 | ||
3304 | if (TREE_CODE (arg1) == REAL_CST) | |
3305 | { | |
3306 | REAL_VALUE_TYPE c; | |
3307 | HOST_WIDE_INT n; | |
3308 | ||
3309 | c = TREE_REAL_CST (arg1); | |
3310 | n = real_to_integer (&c); | |
3311 | ||
3312 | if ((n & 1) == 0) | |
3313 | { | |
3314 | REAL_VALUE_TYPE cint; | |
3315 | real_from_integer (&cint, VOIDmode, n, n < 0 ? -1 : 0, 0); | |
3316 | if (real_identical (&c, &cint)) | |
3317 | return true; | |
3318 | } | |
3319 | } | |
3320 | ||
3321 | break; | |
3322 | ||
3323 | default: | |
3324 | return false; | |
3325 | } | |
3326 | } | |
3327 | } | |
3328 | ||
3329 | return false; | |
3330 | } | |
09c41ee4 | 3331 | |
3332 | /* Given a pointer value OP0, return a simplified version of an | |
3333 | indirection through OP0, or NULL_TREE if no simplification is | |
3334 | possible. Note that the resulting type may be different from | |
3335 | the type pointed to in the sense that it is still compatible | |
3336 | from the langhooks point of view. */ | |
3337 | ||
3338 | tree | |
3339 | gimple_fold_indirect_ref (tree t) | |
3340 | { | |
3341 | tree ptype = TREE_TYPE (t), type = TREE_TYPE (ptype); | |
3342 | tree sub = t; | |
3343 | tree subtype; | |
3344 | ||
3345 | STRIP_NOPS (sub); | |
3346 | subtype = TREE_TYPE (sub); | |
3347 | if (!POINTER_TYPE_P (subtype)) | |
3348 | return NULL_TREE; | |
3349 | ||
3350 | if (TREE_CODE (sub) == ADDR_EXPR) | |
3351 | { | |
3352 | tree op = TREE_OPERAND (sub, 0); | |
3353 | tree optype = TREE_TYPE (op); | |
3354 | /* *&p => p */ | |
3355 | if (useless_type_conversion_p (type, optype)) | |
3356 | return op; | |
3357 | ||
3358 | /* *(foo *)&fooarray => fooarray[0] */ | |
3359 | if (TREE_CODE (optype) == ARRAY_TYPE | |
3360 | && TREE_CODE (TYPE_SIZE (TREE_TYPE (optype))) == INTEGER_CST | |
3361 | && useless_type_conversion_p (type, TREE_TYPE (optype))) | |
3362 | { | |
3363 | tree type_domain = TYPE_DOMAIN (optype); | |
3364 | tree min_val = size_zero_node; | |
3365 | if (type_domain && TYPE_MIN_VALUE (type_domain)) | |
3366 | min_val = TYPE_MIN_VALUE (type_domain); | |
3367 | if (TREE_CODE (min_val) == INTEGER_CST) | |
3368 | return build4 (ARRAY_REF, type, op, min_val, NULL_TREE, NULL_TREE); | |
3369 | } | |
3370 | /* *(foo *)&complexfoo => __real__ complexfoo */ | |
3371 | else if (TREE_CODE (optype) == COMPLEX_TYPE | |
3372 | && useless_type_conversion_p (type, TREE_TYPE (optype))) | |
3373 | return fold_build1 (REALPART_EXPR, type, op); | |
3374 | /* *(foo *)&vectorfoo => BIT_FIELD_REF<vectorfoo,...> */ | |
3375 | else if (TREE_CODE (optype) == VECTOR_TYPE | |
3376 | && useless_type_conversion_p (type, TREE_TYPE (optype))) | |
3377 | { | |
3378 | tree part_width = TYPE_SIZE (type); | |
3379 | tree index = bitsize_int (0); | |
3380 | return fold_build3 (BIT_FIELD_REF, type, op, part_width, index); | |
3381 | } | |
3382 | } | |
3383 | ||
3384 | /* *(p + CST) -> ... */ | |
3385 | if (TREE_CODE (sub) == POINTER_PLUS_EXPR | |
3386 | && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST) | |
3387 | { | |
3388 | tree addr = TREE_OPERAND (sub, 0); | |
3389 | tree off = TREE_OPERAND (sub, 1); | |
3390 | tree addrtype; | |
3391 | ||
3392 | STRIP_NOPS (addr); | |
3393 | addrtype = TREE_TYPE (addr); | |
3394 | ||
3395 | /* ((foo*)&vectorfoo)[1] -> BIT_FIELD_REF<vectorfoo,...> */ | |
3396 | if (TREE_CODE (addr) == ADDR_EXPR | |
3397 | && TREE_CODE (TREE_TYPE (addrtype)) == VECTOR_TYPE | |
3398 | && useless_type_conversion_p (type, TREE_TYPE (TREE_TYPE (addrtype))) | |
3399 | && host_integerp (off, 1)) | |
3400 | { | |
3401 | unsigned HOST_WIDE_INT offset = tree_low_cst (off, 1); | |
3402 | tree part_width = TYPE_SIZE (type); | |
3403 | unsigned HOST_WIDE_INT part_widthi | |
3404 | = tree_low_cst (part_width, 0) / BITS_PER_UNIT; | |
3405 | unsigned HOST_WIDE_INT indexi = offset * BITS_PER_UNIT; | |
3406 | tree index = bitsize_int (indexi); | |
3407 | if (offset / part_widthi | |
3408 | <= TYPE_VECTOR_SUBPARTS (TREE_TYPE (addrtype))) | |
3409 | return fold_build3 (BIT_FIELD_REF, type, TREE_OPERAND (addr, 0), | |
3410 | part_width, index); | |
3411 | } | |
3412 | ||
3413 | /* ((foo*)&complexfoo)[1] -> __imag__ complexfoo */ | |
3414 | if (TREE_CODE (addr) == ADDR_EXPR | |
3415 | && TREE_CODE (TREE_TYPE (addrtype)) == COMPLEX_TYPE | |
3416 | && useless_type_conversion_p (type, TREE_TYPE (TREE_TYPE (addrtype)))) | |
3417 | { | |
3418 | tree size = TYPE_SIZE_UNIT (type); | |
3419 | if (tree_int_cst_equal (size, off)) | |
3420 | return fold_build1 (IMAGPART_EXPR, type, TREE_OPERAND (addr, 0)); | |
3421 | } | |
3422 | ||
3423 | /* *(p + CST) -> MEM_REF <p, CST>. */ | |
3424 | if (TREE_CODE (addr) != ADDR_EXPR | |
3425 | || DECL_P (TREE_OPERAND (addr, 0))) | |
3426 | return fold_build2 (MEM_REF, type, | |
3427 | addr, | |
3428 | build_int_cst_wide (ptype, | |
3429 | TREE_INT_CST_LOW (off), | |
3430 | TREE_INT_CST_HIGH (off))); | |
3431 | } | |
3432 | ||
3433 | /* *(foo *)fooarrptr => (*fooarrptr)[0] */ | |
3434 | if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE | |
3435 | && TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (subtype)))) == INTEGER_CST | |
3436 | && useless_type_conversion_p (type, TREE_TYPE (TREE_TYPE (subtype)))) | |
3437 | { | |
3438 | tree type_domain; | |
3439 | tree min_val = size_zero_node; | |
3440 | tree osub = sub; | |
3441 | sub = gimple_fold_indirect_ref (sub); | |
3442 | if (! sub) | |
3443 | sub = build1 (INDIRECT_REF, TREE_TYPE (subtype), osub); | |
3444 | type_domain = TYPE_DOMAIN (TREE_TYPE (sub)); | |
3445 | if (type_domain && TYPE_MIN_VALUE (type_domain)) | |
3446 | min_val = TYPE_MIN_VALUE (type_domain); | |
3447 | if (TREE_CODE (min_val) == INTEGER_CST) | |
3448 | return build4 (ARRAY_REF, type, sub, min_val, NULL_TREE, NULL_TREE); | |
3449 | } | |
3450 | ||
3451 | return NULL_TREE; | |
3452 | } |