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cbdd87d4 | 1 | /* Statement simplification on GIMPLE. |
6c66f733 | 2 | Copyright (C) 2010, 2011 Free Software Foundation, Inc. |
cbdd87d4 RG |
3 | Split out from tree-ssa-ccp.c. |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it | |
8 | under the terms of the GNU General Public License as published by the | |
9 | Free Software Foundation; either version 3, or (at your option) any | |
10 | later version. | |
11 | ||
12 | GCC is distributed in the hope that it will be useful, but WITHOUT | |
13 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GCC; see the file COPYING3. If not see | |
19 | <http://www.gnu.org/licenses/>. */ | |
20 | ||
21 | #include "config.h" | |
22 | #include "system.h" | |
23 | #include "coretypes.h" | |
24 | #include "tm.h" | |
25 | #include "tree.h" | |
26 | #include "flags.h" | |
cbdd87d4 | 27 | #include "function.h" |
cbdd87d4 RG |
28 | #include "tree-dump.h" |
29 | #include "tree-flow.h" | |
30 | #include "tree-pass.h" | |
31 | #include "tree-ssa-propagate.h" | |
cbdd87d4 | 32 | #include "target.h" |
cfef45c8 | 33 | #include "gimple-fold.h" |
cbdd87d4 | 34 | |
b3b9f3d0 JH |
35 | /* Return true when DECL can be referenced from current unit. |
36 | We can get declarations that are not possible to reference for | |
37 | various reasons: | |
1389294c | 38 | |
1389294c JH |
39 | 1) When analyzing C++ virtual tables. |
40 | C++ virtual tables do have known constructors even | |
41 | when they are keyed to other compilation unit. | |
42 | Those tables can contain pointers to methods and vars | |
43 | in other units. Those methods have both STATIC and EXTERNAL | |
44 | set. | |
45 | 2) In WHOPR mode devirtualization might lead to reference | |
46 | to method that was partitioned elsehwere. | |
47 | In this case we have static VAR_DECL or FUNCTION_DECL | |
48 | that has no corresponding callgraph/varpool node | |
b3b9f3d0 JH |
49 | declaring the body. |
50 | 3) COMDAT functions referred by external vtables that | |
51 | we devirtualize only during final copmilation stage. | |
52 | At this time we already decided that we will not output | |
53 | the function body and thus we can't reference the symbol | |
54 | directly. */ | |
55 | ||
1389294c | 56 | static bool |
b3b9f3d0 | 57 | can_refer_decl_in_current_unit_p (tree decl) |
1389294c JH |
58 | { |
59 | struct varpool_node *vnode; | |
60 | struct cgraph_node *node; | |
61 | ||
b3b9f3d0 JH |
62 | if (!TREE_STATIC (decl) && !DECL_EXTERNAL (decl)) |
63 | return true; | |
1389294c JH |
64 | /* External flag is set, so we deal with C++ reference |
65 | to static object from other file. */ | |
b3b9f3d0 JH |
66 | if (DECL_EXTERNAL (decl) && TREE_STATIC (decl) |
67 | && TREE_CODE (decl) == VAR_DECL) | |
1389294c JH |
68 | { |
69 | /* Just be sure it is not big in frontend setting | |
70 | flags incorrectly. Those variables should never | |
71 | be finalized. */ | |
72 | gcc_checking_assert (!(vnode = varpool_get_node (decl)) | |
73 | || !vnode->finalized); | |
b3b9f3d0 | 74 | return false; |
1389294c | 75 | } |
b3b9f3d0 JH |
76 | /* When function is public, we always can introduce new reference. |
77 | Exception are the COMDAT functions where introducing a direct | |
78 | reference imply need to include function body in the curren tunit. */ | |
79 | if (TREE_PUBLIC (decl) && !DECL_COMDAT (decl)) | |
80 | return true; | |
81 | /* We are not at ltrans stage; so don't worry about WHOPR. | |
82 | Also when still gimplifying all referred comdat functions will be | |
2e9bb6ba JH |
83 | produced. |
84 | ??? as observed in PR20991 for already optimized out comdat virtual functions | |
85 | we may not neccesarily give up because the copy will be output elsewhere when | |
86 | corresponding vtable is output. */ | |
b3b9f3d0 JH |
87 | if (!flag_ltrans && (!DECL_COMDAT (decl) || !cgraph_function_flags_ready)) |
88 | return true; | |
89 | /* If we already output the function body, we are safe. */ | |
90 | if (TREE_ASM_WRITTEN (decl)) | |
91 | return true; | |
1389294c JH |
92 | if (TREE_CODE (decl) == FUNCTION_DECL) |
93 | { | |
94 | node = cgraph_get_node (decl); | |
b3b9f3d0 JH |
95 | /* Check that we still have function body and that we didn't took |
96 | the decision to eliminate offline copy of the function yet. | |
97 | The second is important when devirtualization happens during final | |
98 | compilation stage when making a new reference no longer makes callee | |
99 | to be compiled. */ | |
100 | if (!node || !node->analyzed || node->global.inlined_to) | |
101 | return false; | |
1389294c JH |
102 | } |
103 | else if (TREE_CODE (decl) == VAR_DECL) | |
104 | { | |
105 | vnode = varpool_get_node (decl); | |
106 | if (!vnode || !vnode->finalized) | |
b3b9f3d0 | 107 | return false; |
1389294c | 108 | } |
b3b9f3d0 | 109 | return true; |
1389294c JH |
110 | } |
111 | ||
0038d4e0 | 112 | /* CVAL is value taken from DECL_INITIAL of variable. Try to transform it into |
17f39a39 JH |
113 | acceptable form for is_gimple_min_invariant. */ |
114 | ||
115 | tree | |
116 | canonicalize_constructor_val (tree cval) | |
117 | { | |
118 | STRIP_NOPS (cval); | |
315f5f1b RG |
119 | if (TREE_CODE (cval) == POINTER_PLUS_EXPR |
120 | && TREE_CODE (TREE_OPERAND (cval, 1)) == INTEGER_CST) | |
17f39a39 | 121 | { |
315f5f1b RG |
122 | tree ptr = TREE_OPERAND (cval, 0); |
123 | if (is_gimple_min_invariant (ptr)) | |
124 | cval = build1_loc (EXPR_LOCATION (cval), | |
125 | ADDR_EXPR, TREE_TYPE (ptr), | |
126 | fold_build2 (MEM_REF, TREE_TYPE (TREE_TYPE (ptr)), | |
127 | ptr, | |
128 | fold_convert (ptr_type_node, | |
129 | TREE_OPERAND (cval, 1)))); | |
17f39a39 JH |
130 | } |
131 | if (TREE_CODE (cval) == ADDR_EXPR) | |
132 | { | |
133 | tree base = get_base_address (TREE_OPERAND (cval, 0)); | |
b3b9f3d0 | 134 | |
1389294c JH |
135 | if (base |
136 | && (TREE_CODE (base) == VAR_DECL | |
137 | || TREE_CODE (base) == FUNCTION_DECL) | |
b3b9f3d0 | 138 | && !can_refer_decl_in_current_unit_p (base)) |
1389294c | 139 | return NULL_TREE; |
0038d4e0 | 140 | if (cfun && base && TREE_CODE (base) == VAR_DECL) |
17f39a39 | 141 | add_referenced_var (base); |
0038d4e0 | 142 | /* Fixup types in global initializers. */ |
73aef89e RG |
143 | if (TREE_TYPE (TREE_TYPE (cval)) != TREE_TYPE (TREE_OPERAND (cval, 0))) |
144 | cval = build_fold_addr_expr (TREE_OPERAND (cval, 0)); | |
17f39a39 JH |
145 | } |
146 | return cval; | |
147 | } | |
cbdd87d4 RG |
148 | |
149 | /* If SYM is a constant variable with known value, return the value. | |
150 | NULL_TREE is returned otherwise. */ | |
151 | ||
152 | tree | |
153 | get_symbol_constant_value (tree sym) | |
154 | { | |
64e0f5ff | 155 | if (const_value_known_p (sym)) |
cbdd87d4 RG |
156 | { |
157 | tree val = DECL_INITIAL (sym); | |
158 | if (val) | |
159 | { | |
17f39a39 | 160 | val = canonicalize_constructor_val (val); |
1389294c | 161 | if (val && is_gimple_min_invariant (val)) |
17f39a39 | 162 | return val; |
1389294c JH |
163 | else |
164 | return NULL_TREE; | |
cbdd87d4 RG |
165 | } |
166 | /* Variables declared 'const' without an initializer | |
167 | have zero as the initializer if they may not be | |
168 | overridden at link or run time. */ | |
169 | if (!val | |
cbdd87d4 RG |
170 | && (INTEGRAL_TYPE_P (TREE_TYPE (sym)) |
171 | || SCALAR_FLOAT_TYPE_P (TREE_TYPE (sym)))) | |
e8160c9a | 172 | return build_zero_cst (TREE_TYPE (sym)); |
cbdd87d4 RG |
173 | } |
174 | ||
175 | return NULL_TREE; | |
176 | } | |
177 | ||
178 | ||
cbdd87d4 RG |
179 | |
180 | /* Subroutine of fold_stmt. We perform several simplifications of the | |
181 | memory reference tree EXPR and make sure to re-gimplify them properly | |
182 | after propagation of constant addresses. IS_LHS is true if the | |
183 | reference is supposed to be an lvalue. */ | |
184 | ||
185 | static tree | |
186 | maybe_fold_reference (tree expr, bool is_lhs) | |
187 | { | |
188 | tree *t = &expr; | |
17f39a39 | 189 | tree result; |
cbdd87d4 | 190 | |
f0eddb90 RG |
191 | if ((TREE_CODE (expr) == VIEW_CONVERT_EXPR |
192 | || TREE_CODE (expr) == REALPART_EXPR | |
193 | || TREE_CODE (expr) == IMAGPART_EXPR) | |
194 | && CONSTANT_CLASS_P (TREE_OPERAND (expr, 0))) | |
195 | return fold_unary_loc (EXPR_LOCATION (expr), | |
196 | TREE_CODE (expr), | |
197 | TREE_TYPE (expr), | |
198 | TREE_OPERAND (expr, 0)); | |
199 | else if (TREE_CODE (expr) == BIT_FIELD_REF | |
200 | && CONSTANT_CLASS_P (TREE_OPERAND (expr, 0))) | |
201 | return fold_ternary_loc (EXPR_LOCATION (expr), | |
202 | TREE_CODE (expr), | |
203 | TREE_TYPE (expr), | |
204 | TREE_OPERAND (expr, 0), | |
205 | TREE_OPERAND (expr, 1), | |
206 | TREE_OPERAND (expr, 2)); | |
207 | ||
208 | while (handled_component_p (*t)) | |
209 | t = &TREE_OPERAND (*t, 0); | |
cbdd87d4 | 210 | |
f0eddb90 RG |
211 | /* Canonicalize MEM_REFs invariant address operand. Do this first |
212 | to avoid feeding non-canonical MEM_REFs elsewhere. */ | |
213 | if (TREE_CODE (*t) == MEM_REF | |
214 | && !is_gimple_mem_ref_addr (TREE_OPERAND (*t, 0))) | |
cbdd87d4 | 215 | { |
f0eddb90 RG |
216 | bool volatile_p = TREE_THIS_VOLATILE (*t); |
217 | tree tem = fold_binary (MEM_REF, TREE_TYPE (*t), | |
218 | TREE_OPERAND (*t, 0), | |
219 | TREE_OPERAND (*t, 1)); | |
220 | if (tem) | |
221 | { | |
222 | TREE_THIS_VOLATILE (tem) = volatile_p; | |
223 | *t = tem; | |
224 | tem = maybe_fold_reference (expr, is_lhs); | |
225 | if (tem) | |
226 | return tem; | |
227 | return expr; | |
228 | } | |
cbdd87d4 RG |
229 | } |
230 | ||
f0eddb90 RG |
231 | if (!is_lhs |
232 | && (result = fold_const_aggregate_ref (expr)) | |
233 | && is_gimple_min_invariant (result)) | |
234 | return result; | |
cbdd87d4 | 235 | |
70f34814 RG |
236 | /* Fold back MEM_REFs to reference trees. */ |
237 | if (TREE_CODE (*t) == MEM_REF | |
238 | && TREE_CODE (TREE_OPERAND (*t, 0)) == ADDR_EXPR | |
239 | && integer_zerop (TREE_OPERAND (*t, 1)) | |
240 | && (TREE_THIS_VOLATILE (*t) | |
241 | == TREE_THIS_VOLATILE (TREE_OPERAND (TREE_OPERAND (*t, 0), 0))) | |
242 | && !TYPE_REF_CAN_ALIAS_ALL (TREE_TYPE (TREE_OPERAND (*t, 1))) | |
243 | && (TYPE_MAIN_VARIANT (TREE_TYPE (*t)) | |
244 | == TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (TREE_OPERAND (*t, 1))))) | |
245 | /* We have to look out here to not drop a required conversion | |
246 | from the rhs to the lhs if is_lhs, but we don't have the | |
247 | rhs here to verify that. Thus require strict type | |
248 | compatibility. */ | |
249 | && types_compatible_p (TREE_TYPE (*t), | |
250 | TREE_TYPE (TREE_OPERAND | |
f0eddb90 | 251 | (TREE_OPERAND (*t, 0), 0)))) |
cbdd87d4 | 252 | { |
70f34814 RG |
253 | tree tem; |
254 | *t = TREE_OPERAND (TREE_OPERAND (*t, 0), 0); | |
255 | tem = maybe_fold_reference (expr, is_lhs); | |
256 | if (tem) | |
257 | return tem; | |
258 | return expr; | |
259 | } | |
4d948885 RG |
260 | else if (TREE_CODE (*t) == TARGET_MEM_REF) |
261 | { | |
262 | tree tem = maybe_fold_tmr (*t); | |
263 | if (tem) | |
264 | { | |
265 | *t = tem; | |
266 | tem = maybe_fold_reference (expr, is_lhs); | |
267 | if (tem) | |
268 | return tem; | |
269 | return expr; | |
270 | } | |
271 | } | |
cbdd87d4 RG |
272 | |
273 | return NULL_TREE; | |
274 | } | |
275 | ||
276 | ||
277 | /* Attempt to fold an assignment statement pointed-to by SI. Returns a | |
278 | replacement rhs for the statement or NULL_TREE if no simplification | |
279 | could be made. It is assumed that the operands have been previously | |
280 | folded. */ | |
281 | ||
282 | static tree | |
283 | fold_gimple_assign (gimple_stmt_iterator *si) | |
284 | { | |
285 | gimple stmt = gsi_stmt (*si); | |
286 | enum tree_code subcode = gimple_assign_rhs_code (stmt); | |
287 | location_t loc = gimple_location (stmt); | |
288 | ||
289 | tree result = NULL_TREE; | |
290 | ||
291 | switch (get_gimple_rhs_class (subcode)) | |
292 | { | |
293 | case GIMPLE_SINGLE_RHS: | |
294 | { | |
295 | tree rhs = gimple_assign_rhs1 (stmt); | |
296 | ||
4e71066d | 297 | if (REFERENCE_CLASS_P (rhs)) |
cbdd87d4 RG |
298 | return maybe_fold_reference (rhs, false); |
299 | ||
300 | else if (TREE_CODE (rhs) == ADDR_EXPR) | |
301 | { | |
70f34814 RG |
302 | tree ref = TREE_OPERAND (rhs, 0); |
303 | tree tem = maybe_fold_reference (ref, true); | |
304 | if (tem | |
305 | && TREE_CODE (tem) == MEM_REF | |
306 | && integer_zerop (TREE_OPERAND (tem, 1))) | |
307 | result = fold_convert (TREE_TYPE (rhs), TREE_OPERAND (tem, 0)); | |
308 | else if (tem) | |
cbdd87d4 RG |
309 | result = fold_convert (TREE_TYPE (rhs), |
310 | build_fold_addr_expr_loc (loc, tem)); | |
70f34814 RG |
311 | else if (TREE_CODE (ref) == MEM_REF |
312 | && integer_zerop (TREE_OPERAND (ref, 1))) | |
313 | result = fold_convert (TREE_TYPE (rhs), TREE_OPERAND (ref, 0)); | |
cbdd87d4 RG |
314 | } |
315 | ||
316 | else if (TREE_CODE (rhs) == CONSTRUCTOR | |
317 | && TREE_CODE (TREE_TYPE (rhs)) == VECTOR_TYPE | |
318 | && (CONSTRUCTOR_NELTS (rhs) | |
319 | == TYPE_VECTOR_SUBPARTS (TREE_TYPE (rhs)))) | |
320 | { | |
321 | /* Fold a constant vector CONSTRUCTOR to VECTOR_CST. */ | |
322 | unsigned i; | |
323 | tree val; | |
324 | ||
325 | FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (rhs), i, val) | |
326 | if (TREE_CODE (val) != INTEGER_CST | |
327 | && TREE_CODE (val) != REAL_CST | |
328 | && TREE_CODE (val) != FIXED_CST) | |
329 | return NULL_TREE; | |
330 | ||
331 | return build_vector_from_ctor (TREE_TYPE (rhs), | |
332 | CONSTRUCTOR_ELTS (rhs)); | |
333 | } | |
334 | ||
335 | else if (DECL_P (rhs)) | |
336 | return unshare_expr (get_symbol_constant_value (rhs)); | |
337 | ||
338 | /* If we couldn't fold the RHS, hand over to the generic | |
339 | fold routines. */ | |
340 | if (result == NULL_TREE) | |
341 | result = fold (rhs); | |
342 | ||
343 | /* Strip away useless type conversions. Both the NON_LVALUE_EXPR | |
344 | that may have been added by fold, and "useless" type | |
345 | conversions that might now be apparent due to propagation. */ | |
346 | STRIP_USELESS_TYPE_CONVERSION (result); | |
347 | ||
348 | if (result != rhs && valid_gimple_rhs_p (result)) | |
349 | return result; | |
350 | ||
351 | return NULL_TREE; | |
352 | } | |
353 | break; | |
354 | ||
355 | case GIMPLE_UNARY_RHS: | |
356 | { | |
357 | tree rhs = gimple_assign_rhs1 (stmt); | |
358 | ||
359 | result = fold_unary_loc (loc, subcode, gimple_expr_type (stmt), rhs); | |
360 | if (result) | |
361 | { | |
362 | /* If the operation was a conversion do _not_ mark a | |
363 | resulting constant with TREE_OVERFLOW if the original | |
364 | constant was not. These conversions have implementation | |
365 | defined behavior and retaining the TREE_OVERFLOW flag | |
366 | here would confuse later passes such as VRP. */ | |
367 | if (CONVERT_EXPR_CODE_P (subcode) | |
368 | && TREE_CODE (result) == INTEGER_CST | |
369 | && TREE_CODE (rhs) == INTEGER_CST) | |
370 | TREE_OVERFLOW (result) = TREE_OVERFLOW (rhs); | |
371 | ||
372 | STRIP_USELESS_TYPE_CONVERSION (result); | |
373 | if (valid_gimple_rhs_p (result)) | |
374 | return result; | |
375 | } | |
cbdd87d4 RG |
376 | } |
377 | break; | |
378 | ||
379 | case GIMPLE_BINARY_RHS: | |
9b80d091 KT |
380 | /* Try to canonicalize for boolean-typed X the comparisons |
381 | X == 0, X == 1, X != 0, and X != 1. */ | |
315f5f1b RG |
382 | if (gimple_assign_rhs_code (stmt) == EQ_EXPR |
383 | || gimple_assign_rhs_code (stmt) == NE_EXPR) | |
9b80d091 KT |
384 | { |
385 | tree lhs = gimple_assign_lhs (stmt); | |
386 | tree op1 = gimple_assign_rhs1 (stmt); | |
387 | tree op2 = gimple_assign_rhs2 (stmt); | |
388 | tree type = TREE_TYPE (op1); | |
389 | ||
390 | /* Check whether the comparison operands are of the same boolean | |
391 | type as the result type is. | |
392 | Check that second operand is an integer-constant with value | |
393 | one or zero. */ | |
394 | if (TREE_CODE (op2) == INTEGER_CST | |
395 | && (integer_zerop (op2) || integer_onep (op2)) | |
396 | && useless_type_conversion_p (TREE_TYPE (lhs), type)) | |
397 | { | |
398 | enum tree_code cmp_code = gimple_assign_rhs_code (stmt); | |
399 | bool is_logical_not = false; | |
400 | ||
401 | /* X == 0 and X != 1 is a logical-not.of X | |
402 | X == 1 and X != 0 is X */ | |
403 | if ((cmp_code == EQ_EXPR && integer_zerop (op2)) | |
404 | || (cmp_code == NE_EXPR && integer_onep (op2))) | |
405 | is_logical_not = true; | |
406 | ||
407 | if (is_logical_not == false) | |
408 | result = op1; | |
409 | /* Only for one-bit precision typed X the transformation | |
410 | !X -> ~X is valied. */ | |
411 | else if (TYPE_PRECISION (type) == 1) | |
412 | result = build1_loc (gimple_location (stmt), BIT_NOT_EXPR, | |
413 | type, op1); | |
414 | /* Otherwise we use !X -> X ^ 1. */ | |
415 | else | |
416 | result = build2_loc (gimple_location (stmt), BIT_XOR_EXPR, | |
417 | type, op1, build_int_cst (type, 1)); | |
418 | ||
419 | } | |
420 | } | |
cbdd87d4 RG |
421 | |
422 | if (!result) | |
423 | result = fold_binary_loc (loc, subcode, | |
5fbcc0ed RG |
424 | TREE_TYPE (gimple_assign_lhs (stmt)), |
425 | gimple_assign_rhs1 (stmt), | |
426 | gimple_assign_rhs2 (stmt)); | |
cbdd87d4 RG |
427 | |
428 | if (result) | |
429 | { | |
430 | STRIP_USELESS_TYPE_CONVERSION (result); | |
431 | if (valid_gimple_rhs_p (result)) | |
432 | return result; | |
cbdd87d4 RG |
433 | } |
434 | break; | |
435 | ||
0354c0c7 | 436 | case GIMPLE_TERNARY_RHS: |
4e71066d RG |
437 | /* Try to fold a conditional expression. */ |
438 | if (gimple_assign_rhs_code (stmt) == COND_EXPR) | |
439 | { | |
440 | tree op0 = gimple_assign_rhs1 (stmt); | |
441 | tree tem; | |
442 | bool set = false; | |
443 | location_t cond_loc = gimple_location (stmt); | |
444 | ||
445 | if (COMPARISON_CLASS_P (op0)) | |
446 | { | |
447 | fold_defer_overflow_warnings (); | |
448 | tem = fold_binary_loc (cond_loc, | |
449 | TREE_CODE (op0), TREE_TYPE (op0), | |
450 | TREE_OPERAND (op0, 0), | |
451 | TREE_OPERAND (op0, 1)); | |
452 | /* This is actually a conditional expression, not a GIMPLE | |
453 | conditional statement, however, the valid_gimple_rhs_p | |
454 | test still applies. */ | |
455 | set = (tem && is_gimple_condexpr (tem) | |
456 | && valid_gimple_rhs_p (tem)); | |
457 | fold_undefer_overflow_warnings (set, stmt, 0); | |
458 | } | |
459 | else if (is_gimple_min_invariant (op0)) | |
460 | { | |
461 | tem = op0; | |
462 | set = true; | |
463 | } | |
464 | else | |
465 | return NULL_TREE; | |
466 | ||
467 | if (set) | |
468 | result = fold_build3_loc (cond_loc, COND_EXPR, | |
469 | TREE_TYPE (gimple_assign_lhs (stmt)), tem, | |
470 | gimple_assign_rhs2 (stmt), | |
471 | gimple_assign_rhs3 (stmt)); | |
472 | } | |
473 | ||
474 | if (!result) | |
475 | result = fold_ternary_loc (loc, subcode, | |
476 | TREE_TYPE (gimple_assign_lhs (stmt)), | |
477 | gimple_assign_rhs1 (stmt), | |
478 | gimple_assign_rhs2 (stmt), | |
479 | gimple_assign_rhs3 (stmt)); | |
0354c0c7 BS |
480 | |
481 | if (result) | |
482 | { | |
483 | STRIP_USELESS_TYPE_CONVERSION (result); | |
484 | if (valid_gimple_rhs_p (result)) | |
485 | return result; | |
0354c0c7 BS |
486 | } |
487 | break; | |
488 | ||
cbdd87d4 RG |
489 | case GIMPLE_INVALID_RHS: |
490 | gcc_unreachable (); | |
491 | } | |
492 | ||
493 | return NULL_TREE; | |
494 | } | |
495 | ||
496 | /* Attempt to fold a conditional statement. Return true if any changes were | |
497 | made. We only attempt to fold the condition expression, and do not perform | |
498 | any transformation that would require alteration of the cfg. It is | |
499 | assumed that the operands have been previously folded. */ | |
500 | ||
501 | static bool | |
502 | fold_gimple_cond (gimple stmt) | |
503 | { | |
504 | tree result = fold_binary_loc (gimple_location (stmt), | |
505 | gimple_cond_code (stmt), | |
506 | boolean_type_node, | |
507 | gimple_cond_lhs (stmt), | |
508 | gimple_cond_rhs (stmt)); | |
509 | ||
510 | if (result) | |
511 | { | |
512 | STRIP_USELESS_TYPE_CONVERSION (result); | |
513 | if (is_gimple_condexpr (result) && valid_gimple_rhs_p (result)) | |
514 | { | |
515 | gimple_cond_set_condition_from_tree (stmt, result); | |
516 | return true; | |
517 | } | |
518 | } | |
519 | ||
520 | return false; | |
521 | } | |
522 | ||
523 | /* Convert EXPR into a GIMPLE value suitable for substitution on the | |
524 | RHS of an assignment. Insert the necessary statements before | |
525 | iterator *SI_P. The statement at *SI_P, which must be a GIMPLE_CALL | |
526 | is replaced. If the call is expected to produces a result, then it | |
527 | is replaced by an assignment of the new RHS to the result variable. | |
528 | If the result is to be ignored, then the call is replaced by a | |
fe2ef088 MM |
529 | GIMPLE_NOP. A proper VDEF chain is retained by making the first |
530 | VUSE and the last VDEF of the whole sequence be the same as the replaced | |
531 | statement and using new SSA names for stores in between. */ | |
cbdd87d4 RG |
532 | |
533 | void | |
534 | gimplify_and_update_call_from_tree (gimple_stmt_iterator *si_p, tree expr) | |
535 | { | |
536 | tree lhs; | |
537 | tree tmp = NULL_TREE; /* Silence warning. */ | |
538 | gimple stmt, new_stmt; | |
539 | gimple_stmt_iterator i; | |
540 | gimple_seq stmts = gimple_seq_alloc(); | |
541 | struct gimplify_ctx gctx; | |
542 | gimple last = NULL; | |
fe2ef088 MM |
543 | gimple laststore = NULL; |
544 | tree reaching_vuse; | |
cbdd87d4 RG |
545 | |
546 | stmt = gsi_stmt (*si_p); | |
547 | ||
548 | gcc_assert (is_gimple_call (stmt)); | |
549 | ||
550 | lhs = gimple_call_lhs (stmt); | |
fe2ef088 | 551 | reaching_vuse = gimple_vuse (stmt); |
cbdd87d4 RG |
552 | |
553 | push_gimplify_context (&gctx); | |
21860814 | 554 | gctx.into_ssa = gimple_in_ssa_p (cfun); |
cbdd87d4 RG |
555 | |
556 | if (lhs == NULL_TREE) | |
6e572326 RG |
557 | { |
558 | gimplify_and_add (expr, &stmts); | |
559 | /* We can end up with folding a memcpy of an empty class assignment | |
560 | which gets optimized away by C++ gimplification. */ | |
561 | if (gimple_seq_empty_p (stmts)) | |
562 | { | |
9fdc58de | 563 | pop_gimplify_context (NULL); |
6e572326 RG |
564 | if (gimple_in_ssa_p (cfun)) |
565 | { | |
566 | unlink_stmt_vdef (stmt); | |
567 | release_defs (stmt); | |
568 | } | |
569 | gsi_remove (si_p, true); | |
570 | return; | |
571 | } | |
572 | } | |
cbdd87d4 RG |
573 | else |
574 | tmp = get_initialized_tmp_var (expr, &stmts, NULL); | |
575 | ||
576 | pop_gimplify_context (NULL); | |
577 | ||
578 | if (gimple_has_location (stmt)) | |
579 | annotate_all_with_location (stmts, gimple_location (stmt)); | |
580 | ||
581 | /* The replacement can expose previously unreferenced variables. */ | |
582 | for (i = gsi_start (stmts); !gsi_end_p (i); gsi_next (&i)) | |
583 | { | |
584 | if (last) | |
585 | { | |
586 | gsi_insert_before (si_p, last, GSI_NEW_STMT); | |
587 | gsi_next (si_p); | |
588 | } | |
589 | new_stmt = gsi_stmt (i); | |
edc74207 RG |
590 | if (gimple_in_ssa_p (cfun)) |
591 | { | |
592 | find_new_referenced_vars (new_stmt); | |
593 | mark_symbols_for_renaming (new_stmt); | |
594 | } | |
fe2ef088 MM |
595 | /* If the new statement has a VUSE, update it with exact SSA name we |
596 | know will reach this one. */ | |
597 | if (gimple_vuse (new_stmt)) | |
598 | { | |
599 | /* If we've also seen a previous store create a new VDEF for | |
600 | the latter one, and make that the new reaching VUSE. */ | |
601 | if (laststore) | |
602 | { | |
603 | reaching_vuse = make_ssa_name (gimple_vop (cfun), laststore); | |
604 | gimple_set_vdef (laststore, reaching_vuse); | |
605 | update_stmt (laststore); | |
606 | laststore = NULL; | |
607 | } | |
608 | gimple_set_vuse (new_stmt, reaching_vuse); | |
609 | gimple_set_modified (new_stmt, true); | |
610 | } | |
611 | if (gimple_assign_single_p (new_stmt) | |
612 | && !is_gimple_reg (gimple_assign_lhs (new_stmt))) | |
613 | { | |
614 | laststore = new_stmt; | |
615 | } | |
cbdd87d4 RG |
616 | last = new_stmt; |
617 | } | |
618 | ||
619 | if (lhs == NULL_TREE) | |
620 | { | |
fe2ef088 MM |
621 | /* If we replace a call without LHS that has a VDEF and our new |
622 | sequence ends with a store we must make that store have the same | |
623 | vdef in order not to break the sequencing. This can happen | |
624 | for instance when folding memcpy calls into assignments. */ | |
625 | if (gimple_vdef (stmt) && laststore) | |
626 | { | |
627 | gimple_set_vdef (laststore, gimple_vdef (stmt)); | |
8a1561bc MM |
628 | if (TREE_CODE (gimple_vdef (stmt)) == SSA_NAME) |
629 | SSA_NAME_DEF_STMT (gimple_vdef (stmt)) = laststore; | |
fe2ef088 MM |
630 | update_stmt (laststore); |
631 | } | |
edc74207 | 632 | else if (gimple_in_ssa_p (cfun)) |
fe2ef088 MM |
633 | { |
634 | unlink_stmt_vdef (stmt); | |
635 | release_defs (stmt); | |
636 | } | |
cbdd87d4 RG |
637 | new_stmt = last; |
638 | } | |
639 | else | |
640 | { | |
641 | if (last) | |
642 | { | |
643 | gsi_insert_before (si_p, last, GSI_NEW_STMT); | |
644 | gsi_next (si_p); | |
645 | } | |
8a1561bc MM |
646 | if (laststore && is_gimple_reg (lhs)) |
647 | { | |
648 | gimple_set_vdef (laststore, gimple_vdef (stmt)); | |
649 | update_stmt (laststore); | |
650 | if (TREE_CODE (gimple_vdef (stmt)) == SSA_NAME) | |
651 | SSA_NAME_DEF_STMT (gimple_vdef (stmt)) = laststore; | |
652 | laststore = NULL; | |
653 | } | |
654 | else if (laststore) | |
fe2ef088 MM |
655 | { |
656 | reaching_vuse = make_ssa_name (gimple_vop (cfun), laststore); | |
657 | gimple_set_vdef (laststore, reaching_vuse); | |
658 | update_stmt (laststore); | |
659 | laststore = NULL; | |
660 | } | |
cbdd87d4 | 661 | new_stmt = gimple_build_assign (lhs, tmp); |
8a1561bc MM |
662 | if (!is_gimple_reg (tmp)) |
663 | gimple_set_vuse (new_stmt, reaching_vuse); | |
664 | if (!is_gimple_reg (lhs)) | |
665 | { | |
666 | gimple_set_vdef (new_stmt, gimple_vdef (stmt)); | |
667 | if (TREE_CODE (gimple_vdef (stmt)) == SSA_NAME) | |
668 | SSA_NAME_DEF_STMT (gimple_vdef (stmt)) = new_stmt; | |
669 | } | |
07db7d35 RG |
670 | else if (reaching_vuse == gimple_vuse (stmt)) |
671 | unlink_stmt_vdef (stmt); | |
cbdd87d4 RG |
672 | } |
673 | ||
674 | gimple_set_location (new_stmt, gimple_location (stmt)); | |
675 | gsi_replace (si_p, new_stmt, false); | |
676 | } | |
677 | ||
678 | /* Return the string length, maximum string length or maximum value of | |
679 | ARG in LENGTH. | |
680 | If ARG is an SSA name variable, follow its use-def chains. If LENGTH | |
681 | is not NULL and, for TYPE == 0, its value is not equal to the length | |
682 | we determine or if we are unable to determine the length or value, | |
683 | return false. VISITED is a bitmap of visited variables. | |
684 | TYPE is 0 if string length should be returned, 1 for maximum string | |
685 | length and 2 for maximum value ARG can have. */ | |
686 | ||
687 | static bool | |
688 | get_maxval_strlen (tree arg, tree *length, bitmap visited, int type) | |
689 | { | |
690 | tree var, val; | |
691 | gimple def_stmt; | |
692 | ||
693 | if (TREE_CODE (arg) != SSA_NAME) | |
694 | { | |
695 | if (TREE_CODE (arg) == COND_EXPR) | |
696 | return get_maxval_strlen (COND_EXPR_THEN (arg), length, visited, type) | |
697 | && get_maxval_strlen (COND_EXPR_ELSE (arg), length, visited, type); | |
698 | /* We can end up with &(*iftmp_1)[0] here as well, so handle it. */ | |
699 | else if (TREE_CODE (arg) == ADDR_EXPR | |
700 | && TREE_CODE (TREE_OPERAND (arg, 0)) == ARRAY_REF | |
701 | && integer_zerop (TREE_OPERAND (TREE_OPERAND (arg, 0), 1))) | |
702 | { | |
703 | tree aop0 = TREE_OPERAND (TREE_OPERAND (arg, 0), 0); | |
704 | if (TREE_CODE (aop0) == INDIRECT_REF | |
705 | && TREE_CODE (TREE_OPERAND (aop0, 0)) == SSA_NAME) | |
706 | return get_maxval_strlen (TREE_OPERAND (aop0, 0), | |
707 | length, visited, type); | |
708 | } | |
709 | ||
710 | if (type == 2) | |
711 | { | |
712 | val = arg; | |
713 | if (TREE_CODE (val) != INTEGER_CST | |
714 | || tree_int_cst_sgn (val) < 0) | |
715 | return false; | |
716 | } | |
717 | else | |
718 | val = c_strlen (arg, 1); | |
719 | if (!val) | |
720 | return false; | |
721 | ||
722 | if (*length) | |
723 | { | |
724 | if (type > 0) | |
725 | { | |
726 | if (TREE_CODE (*length) != INTEGER_CST | |
727 | || TREE_CODE (val) != INTEGER_CST) | |
728 | return false; | |
729 | ||
730 | if (tree_int_cst_lt (*length, val)) | |
731 | *length = val; | |
732 | return true; | |
733 | } | |
734 | else if (simple_cst_equal (val, *length) != 1) | |
735 | return false; | |
736 | } | |
737 | ||
738 | *length = val; | |
739 | return true; | |
740 | } | |
741 | ||
742 | /* If we were already here, break the infinite cycle. */ | |
fcaa4ca4 | 743 | if (!bitmap_set_bit (visited, SSA_NAME_VERSION (arg))) |
cbdd87d4 | 744 | return true; |
cbdd87d4 RG |
745 | |
746 | var = arg; | |
747 | def_stmt = SSA_NAME_DEF_STMT (var); | |
748 | ||
749 | switch (gimple_code (def_stmt)) | |
750 | { | |
751 | case GIMPLE_ASSIGN: | |
752 | /* The RHS of the statement defining VAR must either have a | |
753 | constant length or come from another SSA_NAME with a constant | |
754 | length. */ | |
755 | if (gimple_assign_single_p (def_stmt) | |
756 | || gimple_assign_unary_nop_p (def_stmt)) | |
757 | { | |
758 | tree rhs = gimple_assign_rhs1 (def_stmt); | |
759 | return get_maxval_strlen (rhs, length, visited, type); | |
760 | } | |
761 | return false; | |
762 | ||
763 | case GIMPLE_PHI: | |
764 | { | |
765 | /* All the arguments of the PHI node must have the same constant | |
766 | length. */ | |
767 | unsigned i; | |
768 | ||
769 | for (i = 0; i < gimple_phi_num_args (def_stmt); i++) | |
770 | { | |
771 | tree arg = gimple_phi_arg (def_stmt, i)->def; | |
772 | ||
773 | /* If this PHI has itself as an argument, we cannot | |
774 | determine the string length of this argument. However, | |
775 | if we can find a constant string length for the other | |
776 | PHI args then we can still be sure that this is a | |
777 | constant string length. So be optimistic and just | |
778 | continue with the next argument. */ | |
779 | if (arg == gimple_phi_result (def_stmt)) | |
780 | continue; | |
781 | ||
782 | if (!get_maxval_strlen (arg, length, visited, type)) | |
783 | return false; | |
784 | } | |
785 | } | |
786 | return true; | |
787 | ||
788 | default: | |
789 | return false; | |
790 | } | |
791 | } | |
792 | ||
793 | ||
794 | /* Fold builtin call in statement STMT. Returns a simplified tree. | |
795 | We may return a non-constant expression, including another call | |
796 | to a different function and with different arguments, e.g., | |
797 | substituting memcpy for strcpy when the string length is known. | |
798 | Note that some builtins expand into inline code that may not | |
799 | be valid in GIMPLE. Callers must take care. */ | |
800 | ||
801 | tree | |
802 | gimple_fold_builtin (gimple stmt) | |
803 | { | |
804 | tree result, val[3]; | |
805 | tree callee, a; | |
806 | int arg_idx, type; | |
807 | bitmap visited; | |
808 | bool ignore; | |
809 | int nargs; | |
810 | location_t loc = gimple_location (stmt); | |
811 | ||
812 | gcc_assert (is_gimple_call (stmt)); | |
813 | ||
814 | ignore = (gimple_call_lhs (stmt) == NULL); | |
815 | ||
816 | /* First try the generic builtin folder. If that succeeds, return the | |
817 | result directly. */ | |
818 | result = fold_call_stmt (stmt, ignore); | |
819 | if (result) | |
820 | { | |
821 | if (ignore) | |
822 | STRIP_NOPS (result); | |
823 | return result; | |
824 | } | |
825 | ||
826 | /* Ignore MD builtins. */ | |
827 | callee = gimple_call_fndecl (stmt); | |
828 | if (DECL_BUILT_IN_CLASS (callee) == BUILT_IN_MD) | |
829 | return NULL_TREE; | |
830 | ||
831 | /* If the builtin could not be folded, and it has no argument list, | |
832 | we're done. */ | |
833 | nargs = gimple_call_num_args (stmt); | |
834 | if (nargs == 0) | |
835 | return NULL_TREE; | |
836 | ||
837 | /* Limit the work only for builtins we know how to simplify. */ | |
838 | switch (DECL_FUNCTION_CODE (callee)) | |
839 | { | |
840 | case BUILT_IN_STRLEN: | |
841 | case BUILT_IN_FPUTS: | |
842 | case BUILT_IN_FPUTS_UNLOCKED: | |
843 | arg_idx = 0; | |
844 | type = 0; | |
845 | break; | |
846 | case BUILT_IN_STRCPY: | |
847 | case BUILT_IN_STRNCPY: | |
848 | arg_idx = 1; | |
849 | type = 0; | |
850 | break; | |
851 | case BUILT_IN_MEMCPY_CHK: | |
852 | case BUILT_IN_MEMPCPY_CHK: | |
853 | case BUILT_IN_MEMMOVE_CHK: | |
854 | case BUILT_IN_MEMSET_CHK: | |
855 | case BUILT_IN_STRNCPY_CHK: | |
856 | arg_idx = 2; | |
857 | type = 2; | |
858 | break; | |
859 | case BUILT_IN_STRCPY_CHK: | |
860 | case BUILT_IN_STPCPY_CHK: | |
861 | arg_idx = 1; | |
862 | type = 1; | |
863 | break; | |
864 | case BUILT_IN_SNPRINTF_CHK: | |
865 | case BUILT_IN_VSNPRINTF_CHK: | |
866 | arg_idx = 1; | |
867 | type = 2; | |
868 | break; | |
869 | default: | |
870 | return NULL_TREE; | |
871 | } | |
872 | ||
873 | if (arg_idx >= nargs) | |
874 | return NULL_TREE; | |
875 | ||
876 | /* Try to use the dataflow information gathered by the CCP process. */ | |
877 | visited = BITMAP_ALLOC (NULL); | |
878 | bitmap_clear (visited); | |
879 | ||
880 | memset (val, 0, sizeof (val)); | |
881 | a = gimple_call_arg (stmt, arg_idx); | |
882 | if (!get_maxval_strlen (a, &val[arg_idx], visited, type)) | |
883 | val[arg_idx] = NULL_TREE; | |
884 | ||
885 | BITMAP_FREE (visited); | |
886 | ||
887 | result = NULL_TREE; | |
888 | switch (DECL_FUNCTION_CODE (callee)) | |
889 | { | |
890 | case BUILT_IN_STRLEN: | |
891 | if (val[0] && nargs == 1) | |
892 | { | |
893 | tree new_val = | |
894 | fold_convert (TREE_TYPE (gimple_call_lhs (stmt)), val[0]); | |
895 | ||
896 | /* If the result is not a valid gimple value, or not a cast | |
6e4da084 | 897 | of a valid gimple value, then we cannot use the result. */ |
cbdd87d4 | 898 | if (is_gimple_val (new_val) |
3dbe9454 | 899 | || (CONVERT_EXPR_P (new_val) |
cbdd87d4 RG |
900 | && is_gimple_val (TREE_OPERAND (new_val, 0)))) |
901 | return new_val; | |
902 | } | |
903 | break; | |
904 | ||
905 | case BUILT_IN_STRCPY: | |
906 | if (val[1] && is_gimple_val (val[1]) && nargs == 2) | |
907 | result = fold_builtin_strcpy (loc, callee, | |
908 | gimple_call_arg (stmt, 0), | |
909 | gimple_call_arg (stmt, 1), | |
910 | val[1]); | |
911 | break; | |
912 | ||
913 | case BUILT_IN_STRNCPY: | |
914 | if (val[1] && is_gimple_val (val[1]) && nargs == 3) | |
915 | result = fold_builtin_strncpy (loc, callee, | |
916 | gimple_call_arg (stmt, 0), | |
917 | gimple_call_arg (stmt, 1), | |
918 | gimple_call_arg (stmt, 2), | |
919 | val[1]); | |
920 | break; | |
921 | ||
922 | case BUILT_IN_FPUTS: | |
923 | if (nargs == 2) | |
924 | result = fold_builtin_fputs (loc, gimple_call_arg (stmt, 0), | |
925 | gimple_call_arg (stmt, 1), | |
926 | ignore, false, val[0]); | |
927 | break; | |
928 | ||
929 | case BUILT_IN_FPUTS_UNLOCKED: | |
930 | if (nargs == 2) | |
931 | result = fold_builtin_fputs (loc, gimple_call_arg (stmt, 0), | |
932 | gimple_call_arg (stmt, 1), | |
933 | ignore, true, val[0]); | |
934 | break; | |
935 | ||
936 | case BUILT_IN_MEMCPY_CHK: | |
937 | case BUILT_IN_MEMPCPY_CHK: | |
938 | case BUILT_IN_MEMMOVE_CHK: | |
939 | case BUILT_IN_MEMSET_CHK: | |
940 | if (val[2] && is_gimple_val (val[2]) && nargs == 4) | |
941 | result = fold_builtin_memory_chk (loc, callee, | |
942 | gimple_call_arg (stmt, 0), | |
943 | gimple_call_arg (stmt, 1), | |
944 | gimple_call_arg (stmt, 2), | |
945 | gimple_call_arg (stmt, 3), | |
946 | val[2], ignore, | |
947 | DECL_FUNCTION_CODE (callee)); | |
948 | break; | |
949 | ||
950 | case BUILT_IN_STRCPY_CHK: | |
951 | case BUILT_IN_STPCPY_CHK: | |
952 | if (val[1] && is_gimple_val (val[1]) && nargs == 3) | |
953 | result = fold_builtin_stxcpy_chk (loc, callee, | |
954 | gimple_call_arg (stmt, 0), | |
955 | gimple_call_arg (stmt, 1), | |
956 | gimple_call_arg (stmt, 2), | |
957 | val[1], ignore, | |
958 | DECL_FUNCTION_CODE (callee)); | |
959 | break; | |
960 | ||
961 | case BUILT_IN_STRNCPY_CHK: | |
962 | if (val[2] && is_gimple_val (val[2]) && nargs == 4) | |
963 | result = fold_builtin_strncpy_chk (loc, gimple_call_arg (stmt, 0), | |
964 | gimple_call_arg (stmt, 1), | |
965 | gimple_call_arg (stmt, 2), | |
966 | gimple_call_arg (stmt, 3), | |
967 | val[2]); | |
968 | break; | |
969 | ||
970 | case BUILT_IN_SNPRINTF_CHK: | |
971 | case BUILT_IN_VSNPRINTF_CHK: | |
972 | if (val[1] && is_gimple_val (val[1])) | |
973 | result = gimple_fold_builtin_snprintf_chk (stmt, val[1], | |
974 | DECL_FUNCTION_CODE (callee)); | |
975 | break; | |
976 | ||
977 | default: | |
978 | gcc_unreachable (); | |
979 | } | |
980 | ||
981 | if (result && ignore) | |
982 | result = fold_ignored_result (result); | |
983 | return result; | |
984 | } | |
985 | ||
ceeffab0 MJ |
986 | /* Generate code adjusting the first parameter of a call statement determined |
987 | by GSI by DELTA. */ | |
988 | ||
989 | void | |
990 | gimple_adjust_this_by_delta (gimple_stmt_iterator *gsi, tree delta) | |
991 | { | |
992 | gimple call_stmt = gsi_stmt (*gsi); | |
993 | tree parm, tmp; | |
994 | gimple new_stmt; | |
995 | ||
0d82a1c8 | 996 | delta = convert_to_ptrofftype (delta); |
ceeffab0 MJ |
997 | gcc_assert (gimple_call_num_args (call_stmt) >= 1); |
998 | parm = gimple_call_arg (call_stmt, 0); | |
999 | gcc_assert (POINTER_TYPE_P (TREE_TYPE (parm))); | |
1000 | tmp = create_tmp_var (TREE_TYPE (parm), NULL); | |
1001 | add_referenced_var (tmp); | |
1002 | ||
1003 | tmp = make_ssa_name (tmp, NULL); | |
1004 | new_stmt = gimple_build_assign_with_ops (POINTER_PLUS_EXPR, tmp, parm, delta); | |
1005 | SSA_NAME_DEF_STMT (tmp) = new_stmt; | |
1006 | gsi_insert_before (gsi, new_stmt, GSI_SAME_STMT); | |
1007 | gimple_call_set_arg (call_stmt, 0, tmp); | |
1008 | } | |
1ae6fe9b | 1009 | |
49c471e3 MJ |
1010 | /* Return a binfo to be used for devirtualization of calls based on an object |
1011 | represented by a declaration (i.e. a global or automatically allocated one) | |
1012 | or NULL if it cannot be found or is not safe. CST is expected to be an | |
1013 | ADDR_EXPR of such object or the function will return NULL. Currently it is | |
1014 | safe to use such binfo only if it has no base binfo (i.e. no ancestors). */ | |
1015 | ||
1016 | tree | |
1017 | gimple_extract_devirt_binfo_from_cst (tree cst) | |
1018 | { | |
1019 | HOST_WIDE_INT offset, size, max_size; | |
1020 | tree base, type, expected_type, binfo; | |
1021 | bool last_artificial = false; | |
1022 | ||
1023 | if (!flag_devirtualize | |
1024 | || TREE_CODE (cst) != ADDR_EXPR | |
1025 | || TREE_CODE (TREE_TYPE (TREE_TYPE (cst))) != RECORD_TYPE) | |
1026 | return NULL_TREE; | |
1027 | ||
1028 | cst = TREE_OPERAND (cst, 0); | |
1029 | expected_type = TREE_TYPE (cst); | |
1030 | base = get_ref_base_and_extent (cst, &offset, &size, &max_size); | |
1031 | type = TREE_TYPE (base); | |
1032 | if (!DECL_P (base) | |
1033 | || max_size == -1 | |
1034 | || max_size != size | |
1035 | || TREE_CODE (type) != RECORD_TYPE) | |
1036 | return NULL_TREE; | |
1037 | ||
1038 | /* Find the sub-object the constant actually refers to and mark whether it is | |
1039 | an artificial one (as opposed to a user-defined one). */ | |
1040 | while (true) | |
1041 | { | |
1042 | HOST_WIDE_INT pos, size; | |
1043 | tree fld; | |
1044 | ||
1045 | if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (expected_type)) | |
1046 | break; | |
1047 | if (offset < 0) | |
1048 | return NULL_TREE; | |
1049 | ||
1050 | for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld)) | |
1051 | { | |
1052 | if (TREE_CODE (fld) != FIELD_DECL) | |
1053 | continue; | |
1054 | ||
1055 | pos = int_bit_position (fld); | |
1056 | size = tree_low_cst (DECL_SIZE (fld), 1); | |
1057 | if (pos <= offset && (pos + size) > offset) | |
1058 | break; | |
1059 | } | |
1060 | if (!fld || TREE_CODE (TREE_TYPE (fld)) != RECORD_TYPE) | |
1061 | return NULL_TREE; | |
1062 | ||
1063 | last_artificial = DECL_ARTIFICIAL (fld); | |
1064 | type = TREE_TYPE (fld); | |
1065 | offset -= pos; | |
1066 | } | |
1067 | /* Artifical sub-objects are ancestors, we do not want to use them for | |
1068 | devirtualization, at least not here. */ | |
1069 | if (last_artificial) | |
1070 | return NULL_TREE; | |
1071 | binfo = TYPE_BINFO (type); | |
1072 | if (!binfo || BINFO_N_BASE_BINFOS (binfo) > 0) | |
1073 | return NULL_TREE; | |
1074 | else | |
1075 | return binfo; | |
1076 | } | |
1077 | ||
cbdd87d4 RG |
1078 | /* Attempt to fold a call statement referenced by the statement iterator GSI. |
1079 | The statement may be replaced by another statement, e.g., if the call | |
1080 | simplifies to a constant value. Return true if any changes were made. | |
1081 | It is assumed that the operands have been previously folded. */ | |
1082 | ||
ceeffab0 MJ |
1083 | bool |
1084 | gimple_fold_call (gimple_stmt_iterator *gsi, bool inplace) | |
cbdd87d4 RG |
1085 | { |
1086 | gimple stmt = gsi_stmt (*gsi); | |
3b45a007 | 1087 | tree callee; |
cbdd87d4 RG |
1088 | |
1089 | /* Check for builtins that CCP can handle using information not | |
1090 | available in the generic fold routines. */ | |
3b45a007 | 1091 | callee = gimple_call_fndecl (stmt); |
23c1da7a | 1092 | if (!inplace && callee && DECL_BUILT_IN (callee)) |
cbdd87d4 RG |
1093 | { |
1094 | tree result = gimple_fold_builtin (stmt); | |
1095 | ||
1096 | if (result) | |
1097 | { | |
1098 | if (!update_call_from_tree (gsi, result)) | |
1099 | gimplify_and_update_call_from_tree (gsi, result); | |
1100 | return true; | |
1101 | } | |
1102 | } | |
3b45a007 RG |
1103 | |
1104 | /* Check for virtual calls that became direct calls. */ | |
1105 | callee = gimple_call_fn (stmt); | |
25583c4f | 1106 | if (callee && TREE_CODE (callee) == OBJ_TYPE_REF) |
3b45a007 | 1107 | { |
81fa35bd | 1108 | tree binfo, fndecl, obj; |
49c471e3 MJ |
1109 | HOST_WIDE_INT token; |
1110 | ||
1111 | if (gimple_call_addr_fndecl (OBJ_TYPE_REF_EXPR (callee)) != NULL_TREE) | |
1112 | { | |
1113 | gimple_call_set_fn (stmt, OBJ_TYPE_REF_EXPR (callee)); | |
1114 | return true; | |
1115 | } | |
1116 | ||
1117 | obj = OBJ_TYPE_REF_OBJECT (callee); | |
1118 | binfo = gimple_extract_devirt_binfo_from_cst (obj); | |
1119 | if (!binfo) | |
1120 | return false; | |
1121 | token = TREE_INT_CST_LOW (OBJ_TYPE_REF_TOKEN (callee)); | |
81fa35bd | 1122 | fndecl = gimple_get_virt_method_for_binfo (token, binfo); |
49c471e3 MJ |
1123 | if (!fndecl) |
1124 | return false; | |
49c471e3 | 1125 | gimple_call_set_fndecl (stmt, fndecl); |
3b45a007 RG |
1126 | return true; |
1127 | } | |
1128 | ||
cbdd87d4 RG |
1129 | return false; |
1130 | } | |
1131 | ||
1132 | /* Worker for both fold_stmt and fold_stmt_inplace. The INPLACE argument | |
1133 | distinguishes both cases. */ | |
1134 | ||
1135 | static bool | |
1136 | fold_stmt_1 (gimple_stmt_iterator *gsi, bool inplace) | |
1137 | { | |
1138 | bool changed = false; | |
1139 | gimple stmt = gsi_stmt (*gsi); | |
1140 | unsigned i; | |
a9d24544 JJ |
1141 | gimple_stmt_iterator gsinext = *gsi; |
1142 | gimple next_stmt; | |
1143 | ||
1144 | gsi_next (&gsinext); | |
1145 | next_stmt = gsi_end_p (gsinext) ? NULL : gsi_stmt (gsinext); | |
cbdd87d4 RG |
1146 | |
1147 | /* Fold the main computation performed by the statement. */ | |
1148 | switch (gimple_code (stmt)) | |
1149 | { | |
1150 | case GIMPLE_ASSIGN: | |
1151 | { | |
1152 | unsigned old_num_ops = gimple_num_ops (stmt); | |
5fbcc0ed | 1153 | enum tree_code subcode = gimple_assign_rhs_code (stmt); |
cbdd87d4 | 1154 | tree lhs = gimple_assign_lhs (stmt); |
5fbcc0ed RG |
1155 | tree new_rhs; |
1156 | /* First canonicalize operand order. This avoids building new | |
1157 | trees if this is the only thing fold would later do. */ | |
1158 | if ((commutative_tree_code (subcode) | |
1159 | || commutative_ternary_tree_code (subcode)) | |
1160 | && tree_swap_operands_p (gimple_assign_rhs1 (stmt), | |
1161 | gimple_assign_rhs2 (stmt), false)) | |
1162 | { | |
1163 | tree tem = gimple_assign_rhs1 (stmt); | |
1164 | gimple_assign_set_rhs1 (stmt, gimple_assign_rhs2 (stmt)); | |
1165 | gimple_assign_set_rhs2 (stmt, tem); | |
1166 | changed = true; | |
1167 | } | |
1168 | new_rhs = fold_gimple_assign (gsi); | |
cbdd87d4 RG |
1169 | if (new_rhs |
1170 | && !useless_type_conversion_p (TREE_TYPE (lhs), | |
1171 | TREE_TYPE (new_rhs))) | |
1172 | new_rhs = fold_convert (TREE_TYPE (lhs), new_rhs); | |
1173 | if (new_rhs | |
1174 | && (!inplace | |
1175 | || get_gimple_rhs_num_ops (TREE_CODE (new_rhs)) < old_num_ops)) | |
1176 | { | |
1177 | gimple_assign_set_rhs_from_tree (gsi, new_rhs); | |
1178 | changed = true; | |
1179 | } | |
1180 | break; | |
1181 | } | |
1182 | ||
1183 | case GIMPLE_COND: | |
1184 | changed |= fold_gimple_cond (stmt); | |
1185 | break; | |
1186 | ||
1187 | case GIMPLE_CALL: | |
1188 | /* Fold *& in call arguments. */ | |
1189 | for (i = 0; i < gimple_call_num_args (stmt); ++i) | |
1190 | if (REFERENCE_CLASS_P (gimple_call_arg (stmt, i))) | |
1191 | { | |
1192 | tree tmp = maybe_fold_reference (gimple_call_arg (stmt, i), false); | |
1193 | if (tmp) | |
1194 | { | |
1195 | gimple_call_set_arg (stmt, i, tmp); | |
1196 | changed = true; | |
1197 | } | |
1198 | } | |
ceeffab0 | 1199 | changed |= gimple_fold_call (gsi, inplace); |
cbdd87d4 RG |
1200 | break; |
1201 | ||
1202 | case GIMPLE_ASM: | |
1203 | /* Fold *& in asm operands. */ | |
38384150 JJ |
1204 | { |
1205 | size_t noutputs; | |
1206 | const char **oconstraints; | |
1207 | const char *constraint; | |
1208 | bool allows_mem, allows_reg; | |
1209 | ||
1210 | noutputs = gimple_asm_noutputs (stmt); | |
1211 | oconstraints = XALLOCAVEC (const char *, noutputs); | |
1212 | ||
1213 | for (i = 0; i < gimple_asm_noutputs (stmt); ++i) | |
1214 | { | |
1215 | tree link = gimple_asm_output_op (stmt, i); | |
1216 | tree op = TREE_VALUE (link); | |
1217 | oconstraints[i] | |
1218 | = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link))); | |
1219 | if (REFERENCE_CLASS_P (op) | |
1220 | && (op = maybe_fold_reference (op, true)) != NULL_TREE) | |
1221 | { | |
1222 | TREE_VALUE (link) = op; | |
1223 | changed = true; | |
1224 | } | |
1225 | } | |
1226 | for (i = 0; i < gimple_asm_ninputs (stmt); ++i) | |
1227 | { | |
1228 | tree link = gimple_asm_input_op (stmt, i); | |
1229 | tree op = TREE_VALUE (link); | |
1230 | constraint | |
1231 | = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link))); | |
1232 | parse_input_constraint (&constraint, 0, 0, noutputs, 0, | |
1233 | oconstraints, &allows_mem, &allows_reg); | |
1234 | if (REFERENCE_CLASS_P (op) | |
1235 | && (op = maybe_fold_reference (op, !allows_reg && allows_mem)) | |
1236 | != NULL_TREE) | |
1237 | { | |
1238 | TREE_VALUE (link) = op; | |
1239 | changed = true; | |
1240 | } | |
1241 | } | |
1242 | } | |
cbdd87d4 RG |
1243 | break; |
1244 | ||
bd422c4a RG |
1245 | case GIMPLE_DEBUG: |
1246 | if (gimple_debug_bind_p (stmt)) | |
1247 | { | |
1248 | tree val = gimple_debug_bind_get_value (stmt); | |
1249 | if (val | |
1250 | && REFERENCE_CLASS_P (val)) | |
1251 | { | |
1252 | tree tem = maybe_fold_reference (val, false); | |
1253 | if (tem) | |
1254 | { | |
1255 | gimple_debug_bind_set_value (stmt, tem); | |
1256 | changed = true; | |
1257 | } | |
1258 | } | |
1259 | } | |
1260 | break; | |
1261 | ||
cbdd87d4 RG |
1262 | default:; |
1263 | } | |
1264 | ||
a9d24544 JJ |
1265 | /* If stmt folds into nothing and it was the last stmt in a bb, |
1266 | don't call gsi_stmt. */ | |
1267 | if (gsi_end_p (*gsi)) | |
1268 | { | |
1269 | gcc_assert (next_stmt == NULL); | |
1270 | return changed; | |
1271 | } | |
1272 | ||
cbdd87d4 RG |
1273 | stmt = gsi_stmt (*gsi); |
1274 | ||
a9d24544 JJ |
1275 | /* Fold *& on the lhs. Don't do this if stmt folded into nothing, |
1276 | as we'd changing the next stmt. */ | |
1277 | if (gimple_has_lhs (stmt) && stmt != next_stmt) | |
cbdd87d4 RG |
1278 | { |
1279 | tree lhs = gimple_get_lhs (stmt); | |
1280 | if (lhs && REFERENCE_CLASS_P (lhs)) | |
1281 | { | |
1282 | tree new_lhs = maybe_fold_reference (lhs, true); | |
1283 | if (new_lhs) | |
1284 | { | |
1285 | gimple_set_lhs (stmt, new_lhs); | |
1286 | changed = true; | |
1287 | } | |
1288 | } | |
1289 | } | |
1290 | ||
1291 | return changed; | |
1292 | } | |
1293 | ||
1294 | /* Fold the statement pointed to by GSI. In some cases, this function may | |
1295 | replace the whole statement with a new one. Returns true iff folding | |
1296 | makes any changes. | |
1297 | The statement pointed to by GSI should be in valid gimple form but may | |
1298 | be in unfolded state as resulting from for example constant propagation | |
1299 | which can produce *&x = 0. */ | |
1300 | ||
1301 | bool | |
1302 | fold_stmt (gimple_stmt_iterator *gsi) | |
1303 | { | |
1304 | return fold_stmt_1 (gsi, false); | |
1305 | } | |
1306 | ||
59401b92 | 1307 | /* Perform the minimal folding on statement *GSI. Only operations like |
cbdd87d4 RG |
1308 | *&x created by constant propagation are handled. The statement cannot |
1309 | be replaced with a new one. Return true if the statement was | |
1310 | changed, false otherwise. | |
59401b92 | 1311 | The statement *GSI should be in valid gimple form but may |
cbdd87d4 RG |
1312 | be in unfolded state as resulting from for example constant propagation |
1313 | which can produce *&x = 0. */ | |
1314 | ||
1315 | bool | |
59401b92 | 1316 | fold_stmt_inplace (gimple_stmt_iterator *gsi) |
cbdd87d4 | 1317 | { |
59401b92 RG |
1318 | gimple stmt = gsi_stmt (*gsi); |
1319 | bool changed = fold_stmt_1 (gsi, true); | |
1320 | gcc_assert (gsi_stmt (*gsi) == stmt); | |
cbdd87d4 RG |
1321 | return changed; |
1322 | } | |
1323 | ||
e89065a1 SL |
1324 | /* Canonicalize and possibly invert the boolean EXPR; return NULL_TREE |
1325 | if EXPR is null or we don't know how. | |
1326 | If non-null, the result always has boolean type. */ | |
1327 | ||
1328 | static tree | |
1329 | canonicalize_bool (tree expr, bool invert) | |
1330 | { | |
1331 | if (!expr) | |
1332 | return NULL_TREE; | |
1333 | else if (invert) | |
1334 | { | |
1335 | if (integer_nonzerop (expr)) | |
1336 | return boolean_false_node; | |
1337 | else if (integer_zerop (expr)) | |
1338 | return boolean_true_node; | |
1339 | else if (TREE_CODE (expr) == SSA_NAME) | |
1340 | return fold_build2 (EQ_EXPR, boolean_type_node, expr, | |
1341 | build_int_cst (TREE_TYPE (expr), 0)); | |
1342 | else if (TREE_CODE_CLASS (TREE_CODE (expr)) == tcc_comparison) | |
1343 | return fold_build2 (invert_tree_comparison (TREE_CODE (expr), false), | |
1344 | boolean_type_node, | |
1345 | TREE_OPERAND (expr, 0), | |
1346 | TREE_OPERAND (expr, 1)); | |
1347 | else | |
1348 | return NULL_TREE; | |
1349 | } | |
1350 | else | |
1351 | { | |
1352 | if (TREE_CODE (TREE_TYPE (expr)) == BOOLEAN_TYPE) | |
1353 | return expr; | |
1354 | if (integer_nonzerop (expr)) | |
1355 | return boolean_true_node; | |
1356 | else if (integer_zerop (expr)) | |
1357 | return boolean_false_node; | |
1358 | else if (TREE_CODE (expr) == SSA_NAME) | |
1359 | return fold_build2 (NE_EXPR, boolean_type_node, expr, | |
1360 | build_int_cst (TREE_TYPE (expr), 0)); | |
1361 | else if (TREE_CODE_CLASS (TREE_CODE (expr)) == tcc_comparison) | |
1362 | return fold_build2 (TREE_CODE (expr), | |
1363 | boolean_type_node, | |
1364 | TREE_OPERAND (expr, 0), | |
1365 | TREE_OPERAND (expr, 1)); | |
1366 | else | |
1367 | return NULL_TREE; | |
1368 | } | |
1369 | } | |
1370 | ||
1371 | /* Check to see if a boolean expression EXPR is logically equivalent to the | |
1372 | comparison (OP1 CODE OP2). Check for various identities involving | |
1373 | SSA_NAMEs. */ | |
1374 | ||
1375 | static bool | |
1376 | same_bool_comparison_p (const_tree expr, enum tree_code code, | |
1377 | const_tree op1, const_tree op2) | |
1378 | { | |
1379 | gimple s; | |
1380 | ||
1381 | /* The obvious case. */ | |
1382 | if (TREE_CODE (expr) == code | |
1383 | && operand_equal_p (TREE_OPERAND (expr, 0), op1, 0) | |
1384 | && operand_equal_p (TREE_OPERAND (expr, 1), op2, 0)) | |
1385 | return true; | |
1386 | ||
1387 | /* Check for comparing (name, name != 0) and the case where expr | |
1388 | is an SSA_NAME with a definition matching the comparison. */ | |
1389 | if (TREE_CODE (expr) == SSA_NAME | |
1390 | && TREE_CODE (TREE_TYPE (expr)) == BOOLEAN_TYPE) | |
1391 | { | |
1392 | if (operand_equal_p (expr, op1, 0)) | |
1393 | return ((code == NE_EXPR && integer_zerop (op2)) | |
1394 | || (code == EQ_EXPR && integer_nonzerop (op2))); | |
1395 | s = SSA_NAME_DEF_STMT (expr); | |
1396 | if (is_gimple_assign (s) | |
1397 | && gimple_assign_rhs_code (s) == code | |
1398 | && operand_equal_p (gimple_assign_rhs1 (s), op1, 0) | |
1399 | && operand_equal_p (gimple_assign_rhs2 (s), op2, 0)) | |
1400 | return true; | |
1401 | } | |
1402 | ||
1403 | /* If op1 is of the form (name != 0) or (name == 0), and the definition | |
1404 | of name is a comparison, recurse. */ | |
1405 | if (TREE_CODE (op1) == SSA_NAME | |
1406 | && TREE_CODE (TREE_TYPE (op1)) == BOOLEAN_TYPE) | |
1407 | { | |
1408 | s = SSA_NAME_DEF_STMT (op1); | |
1409 | if (is_gimple_assign (s) | |
1410 | && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison) | |
1411 | { | |
1412 | enum tree_code c = gimple_assign_rhs_code (s); | |
1413 | if ((c == NE_EXPR && integer_zerop (op2)) | |
1414 | || (c == EQ_EXPR && integer_nonzerop (op2))) | |
1415 | return same_bool_comparison_p (expr, c, | |
1416 | gimple_assign_rhs1 (s), | |
1417 | gimple_assign_rhs2 (s)); | |
1418 | if ((c == EQ_EXPR && integer_zerop (op2)) | |
1419 | || (c == NE_EXPR && integer_nonzerop (op2))) | |
1420 | return same_bool_comparison_p (expr, | |
1421 | invert_tree_comparison (c, false), | |
1422 | gimple_assign_rhs1 (s), | |
1423 | gimple_assign_rhs2 (s)); | |
1424 | } | |
1425 | } | |
1426 | return false; | |
1427 | } | |
1428 | ||
1429 | /* Check to see if two boolean expressions OP1 and OP2 are logically | |
1430 | equivalent. */ | |
1431 | ||
1432 | static bool | |
1433 | same_bool_result_p (const_tree op1, const_tree op2) | |
1434 | { | |
1435 | /* Simple cases first. */ | |
1436 | if (operand_equal_p (op1, op2, 0)) | |
1437 | return true; | |
1438 | ||
1439 | /* Check the cases where at least one of the operands is a comparison. | |
1440 | These are a bit smarter than operand_equal_p in that they apply some | |
1441 | identifies on SSA_NAMEs. */ | |
1442 | if (TREE_CODE_CLASS (TREE_CODE (op2)) == tcc_comparison | |
1443 | && same_bool_comparison_p (op1, TREE_CODE (op2), | |
1444 | TREE_OPERAND (op2, 0), | |
1445 | TREE_OPERAND (op2, 1))) | |
1446 | return true; | |
1447 | if (TREE_CODE_CLASS (TREE_CODE (op1)) == tcc_comparison | |
1448 | && same_bool_comparison_p (op2, TREE_CODE (op1), | |
1449 | TREE_OPERAND (op1, 0), | |
1450 | TREE_OPERAND (op1, 1))) | |
1451 | return true; | |
1452 | ||
1453 | /* Default case. */ | |
1454 | return false; | |
1455 | } | |
1456 | ||
1457 | /* Forward declarations for some mutually recursive functions. */ | |
1458 | ||
1459 | static tree | |
1460 | and_comparisons_1 (enum tree_code code1, tree op1a, tree op1b, | |
1461 | enum tree_code code2, tree op2a, tree op2b); | |
1462 | static tree | |
1463 | and_var_with_comparison (tree var, bool invert, | |
1464 | enum tree_code code2, tree op2a, tree op2b); | |
1465 | static tree | |
1466 | and_var_with_comparison_1 (gimple stmt, | |
1467 | enum tree_code code2, tree op2a, tree op2b); | |
1468 | static tree | |
1469 | or_comparisons_1 (enum tree_code code1, tree op1a, tree op1b, | |
1470 | enum tree_code code2, tree op2a, tree op2b); | |
1471 | static tree | |
1472 | or_var_with_comparison (tree var, bool invert, | |
1473 | enum tree_code code2, tree op2a, tree op2b); | |
1474 | static tree | |
1475 | or_var_with_comparison_1 (gimple stmt, | |
1476 | enum tree_code code2, tree op2a, tree op2b); | |
1477 | ||
1478 | /* Helper function for and_comparisons_1: try to simplify the AND of the | |
1479 | ssa variable VAR with the comparison specified by (OP2A CODE2 OP2B). | |
1480 | If INVERT is true, invert the value of the VAR before doing the AND. | |
1481 | Return NULL_EXPR if we can't simplify this to a single expression. */ | |
1482 | ||
1483 | static tree | |
1484 | and_var_with_comparison (tree var, bool invert, | |
1485 | enum tree_code code2, tree op2a, tree op2b) | |
1486 | { | |
1487 | tree t; | |
1488 | gimple stmt = SSA_NAME_DEF_STMT (var); | |
1489 | ||
1490 | /* We can only deal with variables whose definitions are assignments. */ | |
1491 | if (!is_gimple_assign (stmt)) | |
1492 | return NULL_TREE; | |
1493 | ||
1494 | /* If we have an inverted comparison, apply DeMorgan's law and rewrite | |
1495 | !var AND (op2a code2 op2b) => !(var OR !(op2a code2 op2b)) | |
1496 | Then we only have to consider the simpler non-inverted cases. */ | |
1497 | if (invert) | |
1498 | t = or_var_with_comparison_1 (stmt, | |
1499 | invert_tree_comparison (code2, false), | |
1500 | op2a, op2b); | |
1501 | else | |
1502 | t = and_var_with_comparison_1 (stmt, code2, op2a, op2b); | |
1503 | return canonicalize_bool (t, invert); | |
1504 | } | |
1505 | ||
1506 | /* Try to simplify the AND of the ssa variable defined by the assignment | |
1507 | STMT with the comparison specified by (OP2A CODE2 OP2B). | |
1508 | Return NULL_EXPR if we can't simplify this to a single expression. */ | |
1509 | ||
1510 | static tree | |
1511 | and_var_with_comparison_1 (gimple stmt, | |
1512 | enum tree_code code2, tree op2a, tree op2b) | |
1513 | { | |
1514 | tree var = gimple_assign_lhs (stmt); | |
1515 | tree true_test_var = NULL_TREE; | |
1516 | tree false_test_var = NULL_TREE; | |
1517 | enum tree_code innercode = gimple_assign_rhs_code (stmt); | |
1518 | ||
1519 | /* Check for identities like (var AND (var == 0)) => false. */ | |
1520 | if (TREE_CODE (op2a) == SSA_NAME | |
1521 | && TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE) | |
1522 | { | |
1523 | if ((code2 == NE_EXPR && integer_zerop (op2b)) | |
1524 | || (code2 == EQ_EXPR && integer_nonzerop (op2b))) | |
1525 | { | |
1526 | true_test_var = op2a; | |
1527 | if (var == true_test_var) | |
1528 | return var; | |
1529 | } | |
1530 | else if ((code2 == EQ_EXPR && integer_zerop (op2b)) | |
1531 | || (code2 == NE_EXPR && integer_nonzerop (op2b))) | |
1532 | { | |
1533 | false_test_var = op2a; | |
1534 | if (var == false_test_var) | |
1535 | return boolean_false_node; | |
1536 | } | |
1537 | } | |
1538 | ||
1539 | /* If the definition is a comparison, recurse on it. */ | |
1540 | if (TREE_CODE_CLASS (innercode) == tcc_comparison) | |
1541 | { | |
1542 | tree t = and_comparisons_1 (innercode, | |
1543 | gimple_assign_rhs1 (stmt), | |
1544 | gimple_assign_rhs2 (stmt), | |
1545 | code2, | |
1546 | op2a, | |
1547 | op2b); | |
1548 | if (t) | |
1549 | return t; | |
1550 | } | |
1551 | ||
1552 | /* If the definition is an AND or OR expression, we may be able to | |
1553 | simplify by reassociating. */ | |
eb9820c0 KT |
1554 | if (TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE |
1555 | && (innercode == BIT_AND_EXPR || innercode == BIT_IOR_EXPR)) | |
e89065a1 SL |
1556 | { |
1557 | tree inner1 = gimple_assign_rhs1 (stmt); | |
1558 | tree inner2 = gimple_assign_rhs2 (stmt); | |
1559 | gimple s; | |
1560 | tree t; | |
1561 | tree partial = NULL_TREE; | |
eb9820c0 | 1562 | bool is_and = (innercode == BIT_AND_EXPR); |
e89065a1 SL |
1563 | |
1564 | /* Check for boolean identities that don't require recursive examination | |
1565 | of inner1/inner2: | |
1566 | inner1 AND (inner1 AND inner2) => inner1 AND inner2 => var | |
1567 | inner1 AND (inner1 OR inner2) => inner1 | |
1568 | !inner1 AND (inner1 AND inner2) => false | |
1569 | !inner1 AND (inner1 OR inner2) => !inner1 AND inner2 | |
1570 | Likewise for similar cases involving inner2. */ | |
1571 | if (inner1 == true_test_var) | |
1572 | return (is_and ? var : inner1); | |
1573 | else if (inner2 == true_test_var) | |
1574 | return (is_and ? var : inner2); | |
1575 | else if (inner1 == false_test_var) | |
1576 | return (is_and | |
1577 | ? boolean_false_node | |
1578 | : and_var_with_comparison (inner2, false, code2, op2a, op2b)); | |
1579 | else if (inner2 == false_test_var) | |
1580 | return (is_and | |
1581 | ? boolean_false_node | |
1582 | : and_var_with_comparison (inner1, false, code2, op2a, op2b)); | |
1583 | ||
1584 | /* Next, redistribute/reassociate the AND across the inner tests. | |
1585 | Compute the first partial result, (inner1 AND (op2a code op2b)) */ | |
1586 | if (TREE_CODE (inner1) == SSA_NAME | |
1587 | && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner1)) | |
1588 | && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison | |
1589 | && (t = maybe_fold_and_comparisons (gimple_assign_rhs_code (s), | |
1590 | gimple_assign_rhs1 (s), | |
1591 | gimple_assign_rhs2 (s), | |
1592 | code2, op2a, op2b))) | |
1593 | { | |
1594 | /* Handle the AND case, where we are reassociating: | |
1595 | (inner1 AND inner2) AND (op2a code2 op2b) | |
1596 | => (t AND inner2) | |
1597 | If the partial result t is a constant, we win. Otherwise | |
1598 | continue on to try reassociating with the other inner test. */ | |
1599 | if (is_and) | |
1600 | { | |
1601 | if (integer_onep (t)) | |
1602 | return inner2; | |
1603 | else if (integer_zerop (t)) | |
1604 | return boolean_false_node; | |
1605 | } | |
1606 | ||
1607 | /* Handle the OR case, where we are redistributing: | |
1608 | (inner1 OR inner2) AND (op2a code2 op2b) | |
1609 | => (t OR (inner2 AND (op2a code2 op2b))) */ | |
8236c8eb JJ |
1610 | else if (integer_onep (t)) |
1611 | return boolean_true_node; | |
1612 | ||
1613 | /* Save partial result for later. */ | |
1614 | partial = t; | |
e89065a1 SL |
1615 | } |
1616 | ||
1617 | /* Compute the second partial result, (inner2 AND (op2a code op2b)) */ | |
1618 | if (TREE_CODE (inner2) == SSA_NAME | |
1619 | && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner2)) | |
1620 | && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison | |
1621 | && (t = maybe_fold_and_comparisons (gimple_assign_rhs_code (s), | |
1622 | gimple_assign_rhs1 (s), | |
1623 | gimple_assign_rhs2 (s), | |
1624 | code2, op2a, op2b))) | |
1625 | { | |
1626 | /* Handle the AND case, where we are reassociating: | |
1627 | (inner1 AND inner2) AND (op2a code2 op2b) | |
1628 | => (inner1 AND t) */ | |
1629 | if (is_and) | |
1630 | { | |
1631 | if (integer_onep (t)) | |
1632 | return inner1; | |
1633 | else if (integer_zerop (t)) | |
1634 | return boolean_false_node; | |
8236c8eb JJ |
1635 | /* If both are the same, we can apply the identity |
1636 | (x AND x) == x. */ | |
1637 | else if (partial && same_bool_result_p (t, partial)) | |
1638 | return t; | |
e89065a1 SL |
1639 | } |
1640 | ||
1641 | /* Handle the OR case. where we are redistributing: | |
1642 | (inner1 OR inner2) AND (op2a code2 op2b) | |
1643 | => (t OR (inner1 AND (op2a code2 op2b))) | |
1644 | => (t OR partial) */ | |
1645 | else | |
1646 | { | |
1647 | if (integer_onep (t)) | |
1648 | return boolean_true_node; | |
1649 | else if (partial) | |
1650 | { | |
1651 | /* We already got a simplification for the other | |
1652 | operand to the redistributed OR expression. The | |
1653 | interesting case is when at least one is false. | |
1654 | Or, if both are the same, we can apply the identity | |
1655 | (x OR x) == x. */ | |
1656 | if (integer_zerop (partial)) | |
1657 | return t; | |
1658 | else if (integer_zerop (t)) | |
1659 | return partial; | |
1660 | else if (same_bool_result_p (t, partial)) | |
1661 | return t; | |
1662 | } | |
1663 | } | |
1664 | } | |
1665 | } | |
1666 | return NULL_TREE; | |
1667 | } | |
1668 | ||
1669 | /* Try to simplify the AND of two comparisons defined by | |
1670 | (OP1A CODE1 OP1B) and (OP2A CODE2 OP2B), respectively. | |
1671 | If this can be done without constructing an intermediate value, | |
1672 | return the resulting tree; otherwise NULL_TREE is returned. | |
1673 | This function is deliberately asymmetric as it recurses on SSA_DEFs | |
1674 | in the first comparison but not the second. */ | |
1675 | ||
1676 | static tree | |
1677 | and_comparisons_1 (enum tree_code code1, tree op1a, tree op1b, | |
1678 | enum tree_code code2, tree op2a, tree op2b) | |
1679 | { | |
1680 | /* First check for ((x CODE1 y) AND (x CODE2 y)). */ | |
1681 | if (operand_equal_p (op1a, op2a, 0) | |
1682 | && operand_equal_p (op1b, op2b, 0)) | |
1683 | { | |
eb9820c0 | 1684 | /* Result will be either NULL_TREE, or a combined comparison. */ |
e89065a1 SL |
1685 | tree t = combine_comparisons (UNKNOWN_LOCATION, |
1686 | TRUTH_ANDIF_EXPR, code1, code2, | |
1687 | boolean_type_node, op1a, op1b); | |
1688 | if (t) | |
1689 | return t; | |
1690 | } | |
1691 | ||
1692 | /* Likewise the swapped case of the above. */ | |
1693 | if (operand_equal_p (op1a, op2b, 0) | |
1694 | && operand_equal_p (op1b, op2a, 0)) | |
1695 | { | |
eb9820c0 | 1696 | /* Result will be either NULL_TREE, or a combined comparison. */ |
e89065a1 SL |
1697 | tree t = combine_comparisons (UNKNOWN_LOCATION, |
1698 | TRUTH_ANDIF_EXPR, code1, | |
1699 | swap_tree_comparison (code2), | |
1700 | boolean_type_node, op1a, op1b); | |
1701 | if (t) | |
1702 | return t; | |
1703 | } | |
1704 | ||
1705 | /* If both comparisons are of the same value against constants, we might | |
1706 | be able to merge them. */ | |
1707 | if (operand_equal_p (op1a, op2a, 0) | |
1708 | && TREE_CODE (op1b) == INTEGER_CST | |
1709 | && TREE_CODE (op2b) == INTEGER_CST) | |
1710 | { | |
1711 | int cmp = tree_int_cst_compare (op1b, op2b); | |
1712 | ||
1713 | /* If we have (op1a == op1b), we should either be able to | |
1714 | return that or FALSE, depending on whether the constant op1b | |
1715 | also satisfies the other comparison against op2b. */ | |
1716 | if (code1 == EQ_EXPR) | |
1717 | { | |
1718 | bool done = true; | |
1719 | bool val; | |
1720 | switch (code2) | |
1721 | { | |
1722 | case EQ_EXPR: val = (cmp == 0); break; | |
1723 | case NE_EXPR: val = (cmp != 0); break; | |
1724 | case LT_EXPR: val = (cmp < 0); break; | |
1725 | case GT_EXPR: val = (cmp > 0); break; | |
1726 | case LE_EXPR: val = (cmp <= 0); break; | |
1727 | case GE_EXPR: val = (cmp >= 0); break; | |
1728 | default: done = false; | |
1729 | } | |
1730 | if (done) | |
1731 | { | |
1732 | if (val) | |
1733 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
1734 | else | |
1735 | return boolean_false_node; | |
1736 | } | |
1737 | } | |
1738 | /* Likewise if the second comparison is an == comparison. */ | |
1739 | else if (code2 == EQ_EXPR) | |
1740 | { | |
1741 | bool done = true; | |
1742 | bool val; | |
1743 | switch (code1) | |
1744 | { | |
1745 | case EQ_EXPR: val = (cmp == 0); break; | |
1746 | case NE_EXPR: val = (cmp != 0); break; | |
1747 | case LT_EXPR: val = (cmp > 0); break; | |
1748 | case GT_EXPR: val = (cmp < 0); break; | |
1749 | case LE_EXPR: val = (cmp >= 0); break; | |
1750 | case GE_EXPR: val = (cmp <= 0); break; | |
1751 | default: done = false; | |
1752 | } | |
1753 | if (done) | |
1754 | { | |
1755 | if (val) | |
1756 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
1757 | else | |
1758 | return boolean_false_node; | |
1759 | } | |
1760 | } | |
1761 | ||
1762 | /* Same business with inequality tests. */ | |
1763 | else if (code1 == NE_EXPR) | |
1764 | { | |
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: | |
1775 | val = false; | |
1776 | } | |
1777 | if (val) | |
1778 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
1779 | } | |
1780 | else if (code2 == NE_EXPR) | |
1781 | { | |
1782 | bool val; | |
1783 | switch (code1) | |
1784 | { | |
1785 | case EQ_EXPR: val = (cmp == 0); break; | |
1786 | case NE_EXPR: val = (cmp != 0); break; | |
1787 | case LT_EXPR: val = (cmp <= 0); break; | |
1788 | case GT_EXPR: val = (cmp >= 0); break; | |
1789 | case LE_EXPR: val = (cmp < 0); break; | |
1790 | case GE_EXPR: val = (cmp > 0); break; | |
1791 | default: | |
1792 | val = false; | |
1793 | } | |
1794 | if (val) | |
1795 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
1796 | } | |
1797 | ||
1798 | /* Chose the more restrictive of two < or <= comparisons. */ | |
1799 | else if ((code1 == LT_EXPR || code1 == LE_EXPR) | |
1800 | && (code2 == LT_EXPR || code2 == LE_EXPR)) | |
1801 | { | |
1802 | if ((cmp < 0) || (cmp == 0 && code1 == LT_EXPR)) | |
1803 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
1804 | else | |
1805 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
1806 | } | |
1807 | ||
1808 | /* Likewise chose the more restrictive of two > or >= comparisons. */ | |
1809 | else if ((code1 == GT_EXPR || code1 == GE_EXPR) | |
1810 | && (code2 == GT_EXPR || code2 == GE_EXPR)) | |
1811 | { | |
1812 | if ((cmp > 0) || (cmp == 0 && code1 == GT_EXPR)) | |
1813 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
1814 | else | |
1815 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
1816 | } | |
1817 | ||
1818 | /* Check for singleton ranges. */ | |
1819 | else if (cmp == 0 | |
1820 | && ((code1 == LE_EXPR && code2 == GE_EXPR) | |
1821 | || (code1 == GE_EXPR && code2 == LE_EXPR))) | |
1822 | return fold_build2 (EQ_EXPR, boolean_type_node, op1a, op2b); | |
1823 | ||
1824 | /* Check for disjoint ranges. */ | |
1825 | else if (cmp <= 0 | |
1826 | && (code1 == LT_EXPR || code1 == LE_EXPR) | |
1827 | && (code2 == GT_EXPR || code2 == GE_EXPR)) | |
1828 | return boolean_false_node; | |
1829 | else if (cmp >= 0 | |
1830 | && (code1 == GT_EXPR || code1 == GE_EXPR) | |
1831 | && (code2 == LT_EXPR || code2 == LE_EXPR)) | |
1832 | return boolean_false_node; | |
1833 | } | |
1834 | ||
1835 | /* Perhaps the first comparison is (NAME != 0) or (NAME == 1) where | |
1836 | NAME's definition is a truth value. See if there are any simplifications | |
1837 | that can be done against the NAME's definition. */ | |
1838 | if (TREE_CODE (op1a) == SSA_NAME | |
1839 | && (code1 == NE_EXPR || code1 == EQ_EXPR) | |
1840 | && (integer_zerop (op1b) || integer_onep (op1b))) | |
1841 | { | |
1842 | bool invert = ((code1 == EQ_EXPR && integer_zerop (op1b)) | |
1843 | || (code1 == NE_EXPR && integer_onep (op1b))); | |
1844 | gimple stmt = SSA_NAME_DEF_STMT (op1a); | |
1845 | switch (gimple_code (stmt)) | |
1846 | { | |
1847 | case GIMPLE_ASSIGN: | |
1848 | /* Try to simplify by copy-propagating the definition. */ | |
1849 | return and_var_with_comparison (op1a, invert, code2, op2a, op2b); | |
1850 | ||
1851 | case GIMPLE_PHI: | |
1852 | /* If every argument to the PHI produces the same result when | |
1853 | ANDed with the second comparison, we win. | |
1854 | Do not do this unless the type is bool since we need a bool | |
1855 | result here anyway. */ | |
1856 | if (TREE_CODE (TREE_TYPE (op1a)) == BOOLEAN_TYPE) | |
1857 | { | |
1858 | tree result = NULL_TREE; | |
1859 | unsigned i; | |
1860 | for (i = 0; i < gimple_phi_num_args (stmt); i++) | |
1861 | { | |
1862 | tree arg = gimple_phi_arg_def (stmt, i); | |
1863 | ||
1864 | /* If this PHI has itself as an argument, ignore it. | |
1865 | If all the other args produce the same result, | |
1866 | we're still OK. */ | |
1867 | if (arg == gimple_phi_result (stmt)) | |
1868 | continue; | |
1869 | else if (TREE_CODE (arg) == INTEGER_CST) | |
1870 | { | |
1871 | if (invert ? integer_nonzerop (arg) : integer_zerop (arg)) | |
1872 | { | |
1873 | if (!result) | |
1874 | result = boolean_false_node; | |
1875 | else if (!integer_zerop (result)) | |
1876 | return NULL_TREE; | |
1877 | } | |
1878 | else if (!result) | |
1879 | result = fold_build2 (code2, boolean_type_node, | |
1880 | op2a, op2b); | |
1881 | else if (!same_bool_comparison_p (result, | |
1882 | code2, op2a, op2b)) | |
1883 | return NULL_TREE; | |
1884 | } | |
0e8b84ec JJ |
1885 | else if (TREE_CODE (arg) == SSA_NAME |
1886 | && !SSA_NAME_IS_DEFAULT_DEF (arg)) | |
e89065a1 | 1887 | { |
6c66f733 JJ |
1888 | tree temp; |
1889 | gimple def_stmt = SSA_NAME_DEF_STMT (arg); | |
1890 | /* In simple cases we can look through PHI nodes, | |
1891 | but we have to be careful with loops. | |
1892 | See PR49073. */ | |
1893 | if (! dom_info_available_p (CDI_DOMINATORS) | |
1894 | || gimple_bb (def_stmt) == gimple_bb (stmt) | |
1895 | || dominated_by_p (CDI_DOMINATORS, | |
1896 | gimple_bb (def_stmt), | |
1897 | gimple_bb (stmt))) | |
1898 | return NULL_TREE; | |
1899 | temp = and_var_with_comparison (arg, invert, code2, | |
1900 | op2a, op2b); | |
e89065a1 SL |
1901 | if (!temp) |
1902 | return NULL_TREE; | |
1903 | else if (!result) | |
1904 | result = temp; | |
1905 | else if (!same_bool_result_p (result, temp)) | |
1906 | return NULL_TREE; | |
1907 | } | |
1908 | else | |
1909 | return NULL_TREE; | |
1910 | } | |
1911 | return result; | |
1912 | } | |
1913 | ||
1914 | default: | |
1915 | break; | |
1916 | } | |
1917 | } | |
1918 | return NULL_TREE; | |
1919 | } | |
1920 | ||
1921 | /* Try to simplify the AND of two comparisons, specified by | |
1922 | (OP1A CODE1 OP1B) and (OP2B CODE2 OP2B), respectively. | |
1923 | If this can be simplified to a single expression (without requiring | |
1924 | introducing more SSA variables to hold intermediate values), | |
1925 | return the resulting tree. Otherwise return NULL_TREE. | |
1926 | If the result expression is non-null, it has boolean type. */ | |
1927 | ||
1928 | tree | |
1929 | maybe_fold_and_comparisons (enum tree_code code1, tree op1a, tree op1b, | |
1930 | enum tree_code code2, tree op2a, tree op2b) | |
1931 | { | |
1932 | tree t = and_comparisons_1 (code1, op1a, op1b, code2, op2a, op2b); | |
1933 | if (t) | |
1934 | return t; | |
1935 | else | |
1936 | return and_comparisons_1 (code2, op2a, op2b, code1, op1a, op1b); | |
1937 | } | |
1938 | ||
1939 | /* Helper function for or_comparisons_1: try to simplify the OR of the | |
1940 | ssa variable VAR with the comparison specified by (OP2A CODE2 OP2B). | |
1941 | If INVERT is true, invert the value of VAR before doing the OR. | |
1942 | Return NULL_EXPR if we can't simplify this to a single expression. */ | |
1943 | ||
1944 | static tree | |
1945 | or_var_with_comparison (tree var, bool invert, | |
1946 | enum tree_code code2, tree op2a, tree op2b) | |
1947 | { | |
1948 | tree t; | |
1949 | gimple stmt = SSA_NAME_DEF_STMT (var); | |
1950 | ||
1951 | /* We can only deal with variables whose definitions are assignments. */ | |
1952 | if (!is_gimple_assign (stmt)) | |
1953 | return NULL_TREE; | |
1954 | ||
1955 | /* If we have an inverted comparison, apply DeMorgan's law and rewrite | |
1956 | !var OR (op2a code2 op2b) => !(var AND !(op2a code2 op2b)) | |
1957 | Then we only have to consider the simpler non-inverted cases. */ | |
1958 | if (invert) | |
1959 | t = and_var_with_comparison_1 (stmt, | |
1960 | invert_tree_comparison (code2, false), | |
1961 | op2a, op2b); | |
1962 | else | |
1963 | t = or_var_with_comparison_1 (stmt, code2, op2a, op2b); | |
1964 | return canonicalize_bool (t, invert); | |
1965 | } | |
1966 | ||
1967 | /* Try to simplify the OR of the ssa variable defined by the assignment | |
1968 | STMT with the comparison specified by (OP2A CODE2 OP2B). | |
1969 | Return NULL_EXPR if we can't simplify this to a single expression. */ | |
1970 | ||
1971 | static tree | |
1972 | or_var_with_comparison_1 (gimple stmt, | |
1973 | enum tree_code code2, tree op2a, tree op2b) | |
1974 | { | |
1975 | tree var = gimple_assign_lhs (stmt); | |
1976 | tree true_test_var = NULL_TREE; | |
1977 | tree false_test_var = NULL_TREE; | |
1978 | enum tree_code innercode = gimple_assign_rhs_code (stmt); | |
1979 | ||
1980 | /* Check for identities like (var OR (var != 0)) => true . */ | |
1981 | if (TREE_CODE (op2a) == SSA_NAME | |
1982 | && TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE) | |
1983 | { | |
1984 | if ((code2 == NE_EXPR && integer_zerop (op2b)) | |
1985 | || (code2 == EQ_EXPR && integer_nonzerop (op2b))) | |
1986 | { | |
1987 | true_test_var = op2a; | |
1988 | if (var == true_test_var) | |
1989 | return var; | |
1990 | } | |
1991 | else if ((code2 == EQ_EXPR && integer_zerop (op2b)) | |
1992 | || (code2 == NE_EXPR && integer_nonzerop (op2b))) | |
1993 | { | |
1994 | false_test_var = op2a; | |
1995 | if (var == false_test_var) | |
1996 | return boolean_true_node; | |
1997 | } | |
1998 | } | |
1999 | ||
2000 | /* If the definition is a comparison, recurse on it. */ | |
2001 | if (TREE_CODE_CLASS (innercode) == tcc_comparison) | |
2002 | { | |
2003 | tree t = or_comparisons_1 (innercode, | |
2004 | gimple_assign_rhs1 (stmt), | |
2005 | gimple_assign_rhs2 (stmt), | |
2006 | code2, | |
2007 | op2a, | |
2008 | op2b); | |
2009 | if (t) | |
2010 | return t; | |
2011 | } | |
2012 | ||
2013 | /* If the definition is an AND or OR expression, we may be able to | |
2014 | simplify by reassociating. */ | |
eb9820c0 KT |
2015 | if (TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE |
2016 | && (innercode == BIT_AND_EXPR || innercode == BIT_IOR_EXPR)) | |
e89065a1 SL |
2017 | { |
2018 | tree inner1 = gimple_assign_rhs1 (stmt); | |
2019 | tree inner2 = gimple_assign_rhs2 (stmt); | |
2020 | gimple s; | |
2021 | tree t; | |
2022 | tree partial = NULL_TREE; | |
eb9820c0 | 2023 | bool is_or = (innercode == BIT_IOR_EXPR); |
e89065a1 SL |
2024 | |
2025 | /* Check for boolean identities that don't require recursive examination | |
2026 | of inner1/inner2: | |
2027 | inner1 OR (inner1 OR inner2) => inner1 OR inner2 => var | |
2028 | inner1 OR (inner1 AND inner2) => inner1 | |
2029 | !inner1 OR (inner1 OR inner2) => true | |
2030 | !inner1 OR (inner1 AND inner2) => !inner1 OR inner2 | |
2031 | */ | |
2032 | if (inner1 == true_test_var) | |
2033 | return (is_or ? var : inner1); | |
2034 | else if (inner2 == true_test_var) | |
2035 | return (is_or ? var : inner2); | |
2036 | else if (inner1 == false_test_var) | |
2037 | return (is_or | |
2038 | ? boolean_true_node | |
2039 | : or_var_with_comparison (inner2, false, code2, op2a, op2b)); | |
2040 | else if (inner2 == false_test_var) | |
2041 | return (is_or | |
2042 | ? boolean_true_node | |
2043 | : or_var_with_comparison (inner1, false, code2, op2a, op2b)); | |
2044 | ||
2045 | /* Next, redistribute/reassociate the OR across the inner tests. | |
2046 | Compute the first partial result, (inner1 OR (op2a code op2b)) */ | |
2047 | if (TREE_CODE (inner1) == SSA_NAME | |
2048 | && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner1)) | |
2049 | && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison | |
2050 | && (t = maybe_fold_or_comparisons (gimple_assign_rhs_code (s), | |
2051 | gimple_assign_rhs1 (s), | |
2052 | gimple_assign_rhs2 (s), | |
2053 | code2, op2a, op2b))) | |
2054 | { | |
2055 | /* Handle the OR case, where we are reassociating: | |
2056 | (inner1 OR inner2) OR (op2a code2 op2b) | |
2057 | => (t OR inner2) | |
2058 | If the partial result t is a constant, we win. Otherwise | |
2059 | continue on to try reassociating with the other inner test. */ | |
8236c8eb | 2060 | if (is_or) |
e89065a1 SL |
2061 | { |
2062 | if (integer_onep (t)) | |
2063 | return boolean_true_node; | |
2064 | else if (integer_zerop (t)) | |
2065 | return inner2; | |
2066 | } | |
2067 | ||
2068 | /* Handle the AND case, where we are redistributing: | |
2069 | (inner1 AND inner2) OR (op2a code2 op2b) | |
2070 | => (t AND (inner2 OR (op2a code op2b))) */ | |
8236c8eb JJ |
2071 | else if (integer_zerop (t)) |
2072 | return boolean_false_node; | |
2073 | ||
2074 | /* Save partial result for later. */ | |
2075 | partial = t; | |
e89065a1 SL |
2076 | } |
2077 | ||
2078 | /* Compute the second partial result, (inner2 OR (op2a code op2b)) */ | |
2079 | if (TREE_CODE (inner2) == SSA_NAME | |
2080 | && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner2)) | |
2081 | && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison | |
2082 | && (t = maybe_fold_or_comparisons (gimple_assign_rhs_code (s), | |
2083 | gimple_assign_rhs1 (s), | |
2084 | gimple_assign_rhs2 (s), | |
2085 | code2, op2a, op2b))) | |
2086 | { | |
2087 | /* Handle the OR case, where we are reassociating: | |
2088 | (inner1 OR inner2) OR (op2a code2 op2b) | |
8236c8eb JJ |
2089 | => (inner1 OR t) |
2090 | => (t OR partial) */ | |
2091 | if (is_or) | |
e89065a1 SL |
2092 | { |
2093 | if (integer_zerop (t)) | |
2094 | return inner1; | |
2095 | else if (integer_onep (t)) | |
2096 | return boolean_true_node; | |
8236c8eb JJ |
2097 | /* If both are the same, we can apply the identity |
2098 | (x OR x) == x. */ | |
2099 | else if (partial && same_bool_result_p (t, partial)) | |
2100 | return t; | |
e89065a1 SL |
2101 | } |
2102 | ||
2103 | /* Handle the AND case, where we are redistributing: | |
2104 | (inner1 AND inner2) OR (op2a code2 op2b) | |
2105 | => (t AND (inner1 OR (op2a code2 op2b))) | |
2106 | => (t AND partial) */ | |
2107 | else | |
2108 | { | |
2109 | if (integer_zerop (t)) | |
2110 | return boolean_false_node; | |
2111 | else if (partial) | |
2112 | { | |
2113 | /* We already got a simplification for the other | |
2114 | operand to the redistributed AND expression. The | |
2115 | interesting case is when at least one is true. | |
2116 | Or, if both are the same, we can apply the identity | |
8236c8eb | 2117 | (x AND x) == x. */ |
e89065a1 SL |
2118 | if (integer_onep (partial)) |
2119 | return t; | |
2120 | else if (integer_onep (t)) | |
2121 | return partial; | |
2122 | else if (same_bool_result_p (t, partial)) | |
8236c8eb | 2123 | return t; |
e89065a1 SL |
2124 | } |
2125 | } | |
2126 | } | |
2127 | } | |
2128 | return NULL_TREE; | |
2129 | } | |
2130 | ||
2131 | /* Try to simplify the OR of two comparisons defined by | |
2132 | (OP1A CODE1 OP1B) and (OP2A CODE2 OP2B), respectively. | |
2133 | If this can be done without constructing an intermediate value, | |
2134 | return the resulting tree; otherwise NULL_TREE is returned. | |
2135 | This function is deliberately asymmetric as it recurses on SSA_DEFs | |
2136 | in the first comparison but not the second. */ | |
2137 | ||
2138 | static tree | |
2139 | or_comparisons_1 (enum tree_code code1, tree op1a, tree op1b, | |
2140 | enum tree_code code2, tree op2a, tree op2b) | |
2141 | { | |
2142 | /* First check for ((x CODE1 y) OR (x CODE2 y)). */ | |
2143 | if (operand_equal_p (op1a, op2a, 0) | |
2144 | && operand_equal_p (op1b, op2b, 0)) | |
2145 | { | |
eb9820c0 | 2146 | /* Result will be either NULL_TREE, or a combined comparison. */ |
e89065a1 SL |
2147 | tree t = combine_comparisons (UNKNOWN_LOCATION, |
2148 | TRUTH_ORIF_EXPR, code1, code2, | |
2149 | boolean_type_node, op1a, op1b); | |
2150 | if (t) | |
2151 | return t; | |
2152 | } | |
2153 | ||
2154 | /* Likewise the swapped case of the above. */ | |
2155 | if (operand_equal_p (op1a, op2b, 0) | |
2156 | && operand_equal_p (op1b, op2a, 0)) | |
2157 | { | |
eb9820c0 | 2158 | /* Result will be either NULL_TREE, or a combined comparison. */ |
e89065a1 SL |
2159 | tree t = combine_comparisons (UNKNOWN_LOCATION, |
2160 | TRUTH_ORIF_EXPR, code1, | |
2161 | swap_tree_comparison (code2), | |
2162 | boolean_type_node, op1a, op1b); | |
2163 | if (t) | |
2164 | return t; | |
2165 | } | |
2166 | ||
2167 | /* If both comparisons are of the same value against constants, we might | |
2168 | be able to merge them. */ | |
2169 | if (operand_equal_p (op1a, op2a, 0) | |
2170 | && TREE_CODE (op1b) == INTEGER_CST | |
2171 | && TREE_CODE (op2b) == INTEGER_CST) | |
2172 | { | |
2173 | int cmp = tree_int_cst_compare (op1b, op2b); | |
2174 | ||
2175 | /* If we have (op1a != op1b), we should either be able to | |
2176 | return that or TRUE, depending on whether the constant op1b | |
2177 | also satisfies the other comparison against op2b. */ | |
2178 | if (code1 == NE_EXPR) | |
2179 | { | |
2180 | bool done = true; | |
2181 | bool val; | |
2182 | switch (code2) | |
2183 | { | |
2184 | case EQ_EXPR: val = (cmp == 0); break; | |
2185 | case NE_EXPR: val = (cmp != 0); break; | |
2186 | case LT_EXPR: val = (cmp < 0); break; | |
2187 | case GT_EXPR: val = (cmp > 0); break; | |
2188 | case LE_EXPR: val = (cmp <= 0); break; | |
2189 | case GE_EXPR: val = (cmp >= 0); break; | |
2190 | default: done = false; | |
2191 | } | |
2192 | if (done) | |
2193 | { | |
2194 | if (val) | |
2195 | return boolean_true_node; | |
2196 | else | |
2197 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2198 | } | |
2199 | } | |
2200 | /* Likewise if the second comparison is a != comparison. */ | |
2201 | else if (code2 == NE_EXPR) | |
2202 | { | |
2203 | bool done = true; | |
2204 | bool val; | |
2205 | switch (code1) | |
2206 | { | |
2207 | case EQ_EXPR: val = (cmp == 0); break; | |
2208 | case NE_EXPR: val = (cmp != 0); break; | |
2209 | case LT_EXPR: val = (cmp > 0); break; | |
2210 | case GT_EXPR: val = (cmp < 0); break; | |
2211 | case LE_EXPR: val = (cmp >= 0); break; | |
2212 | case GE_EXPR: val = (cmp <= 0); break; | |
2213 | default: done = false; | |
2214 | } | |
2215 | if (done) | |
2216 | { | |
2217 | if (val) | |
2218 | return boolean_true_node; | |
2219 | else | |
2220 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2221 | } | |
2222 | } | |
2223 | ||
2224 | /* See if an equality test is redundant with the other comparison. */ | |
2225 | else if (code1 == EQ_EXPR) | |
2226 | { | |
2227 | bool val; | |
2228 | switch (code2) | |
2229 | { | |
2230 | case EQ_EXPR: val = (cmp == 0); break; | |
2231 | case NE_EXPR: val = (cmp != 0); break; | |
2232 | case LT_EXPR: val = (cmp < 0); break; | |
2233 | case GT_EXPR: val = (cmp > 0); break; | |
2234 | case LE_EXPR: val = (cmp <= 0); break; | |
2235 | case GE_EXPR: val = (cmp >= 0); break; | |
2236 | default: | |
2237 | val = false; | |
2238 | } | |
2239 | if (val) | |
2240 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2241 | } | |
2242 | else if (code2 == EQ_EXPR) | |
2243 | { | |
2244 | bool val; | |
2245 | switch (code1) | |
2246 | { | |
2247 | case EQ_EXPR: val = (cmp == 0); break; | |
2248 | case NE_EXPR: val = (cmp != 0); break; | |
2249 | case LT_EXPR: val = (cmp > 0); break; | |
2250 | case GT_EXPR: val = (cmp < 0); break; | |
2251 | case LE_EXPR: val = (cmp >= 0); break; | |
2252 | case GE_EXPR: val = (cmp <= 0); break; | |
2253 | default: | |
2254 | val = false; | |
2255 | } | |
2256 | if (val) | |
2257 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2258 | } | |
2259 | ||
2260 | /* Chose the less restrictive of two < or <= comparisons. */ | |
2261 | else if ((code1 == LT_EXPR || code1 == LE_EXPR) | |
2262 | && (code2 == LT_EXPR || code2 == LE_EXPR)) | |
2263 | { | |
2264 | if ((cmp < 0) || (cmp == 0 && code1 == LT_EXPR)) | |
2265 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2266 | else | |
2267 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2268 | } | |
2269 | ||
2270 | /* Likewise chose the less restrictive of two > or >= comparisons. */ | |
2271 | else if ((code1 == GT_EXPR || code1 == GE_EXPR) | |
2272 | && (code2 == GT_EXPR || code2 == GE_EXPR)) | |
2273 | { | |
2274 | if ((cmp > 0) || (cmp == 0 && code1 == GT_EXPR)) | |
2275 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2276 | else | |
2277 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2278 | } | |
2279 | ||
2280 | /* Check for singleton ranges. */ | |
2281 | else if (cmp == 0 | |
2282 | && ((code1 == LT_EXPR && code2 == GT_EXPR) | |
2283 | || (code1 == GT_EXPR && code2 == LT_EXPR))) | |
2284 | return fold_build2 (NE_EXPR, boolean_type_node, op1a, op2b); | |
2285 | ||
2286 | /* Check for less/greater pairs that don't restrict the range at all. */ | |
2287 | else if (cmp >= 0 | |
2288 | && (code1 == LT_EXPR || code1 == LE_EXPR) | |
2289 | && (code2 == GT_EXPR || code2 == GE_EXPR)) | |
2290 | return boolean_true_node; | |
2291 | else if (cmp <= 0 | |
2292 | && (code1 == GT_EXPR || code1 == GE_EXPR) | |
2293 | && (code2 == LT_EXPR || code2 == LE_EXPR)) | |
2294 | return boolean_true_node; | |
2295 | } | |
2296 | ||
2297 | /* Perhaps the first comparison is (NAME != 0) or (NAME == 1) where | |
2298 | NAME's definition is a truth value. See if there are any simplifications | |
2299 | that can be done against the NAME's definition. */ | |
2300 | if (TREE_CODE (op1a) == SSA_NAME | |
2301 | && (code1 == NE_EXPR || code1 == EQ_EXPR) | |
2302 | && (integer_zerop (op1b) || integer_onep (op1b))) | |
2303 | { | |
2304 | bool invert = ((code1 == EQ_EXPR && integer_zerop (op1b)) | |
2305 | || (code1 == NE_EXPR && integer_onep (op1b))); | |
2306 | gimple stmt = SSA_NAME_DEF_STMT (op1a); | |
2307 | switch (gimple_code (stmt)) | |
2308 | { | |
2309 | case GIMPLE_ASSIGN: | |
2310 | /* Try to simplify by copy-propagating the definition. */ | |
2311 | return or_var_with_comparison (op1a, invert, code2, op2a, op2b); | |
2312 | ||
2313 | case GIMPLE_PHI: | |
2314 | /* If every argument to the PHI produces the same result when | |
2315 | ORed with the second comparison, we win. | |
2316 | Do not do this unless the type is bool since we need a bool | |
2317 | result here anyway. */ | |
2318 | if (TREE_CODE (TREE_TYPE (op1a)) == BOOLEAN_TYPE) | |
2319 | { | |
2320 | tree result = NULL_TREE; | |
2321 | unsigned i; | |
2322 | for (i = 0; i < gimple_phi_num_args (stmt); i++) | |
2323 | { | |
2324 | tree arg = gimple_phi_arg_def (stmt, i); | |
2325 | ||
2326 | /* If this PHI has itself as an argument, ignore it. | |
2327 | If all the other args produce the same result, | |
2328 | we're still OK. */ | |
2329 | if (arg == gimple_phi_result (stmt)) | |
2330 | continue; | |
2331 | else if (TREE_CODE (arg) == INTEGER_CST) | |
2332 | { | |
2333 | if (invert ? integer_zerop (arg) : integer_nonzerop (arg)) | |
2334 | { | |
2335 | if (!result) | |
2336 | result = boolean_true_node; | |
2337 | else if (!integer_onep (result)) | |
2338 | return NULL_TREE; | |
2339 | } | |
2340 | else if (!result) | |
2341 | result = fold_build2 (code2, boolean_type_node, | |
2342 | op2a, op2b); | |
2343 | else if (!same_bool_comparison_p (result, | |
2344 | code2, op2a, op2b)) | |
2345 | return NULL_TREE; | |
2346 | } | |
0e8b84ec JJ |
2347 | else if (TREE_CODE (arg) == SSA_NAME |
2348 | && !SSA_NAME_IS_DEFAULT_DEF (arg)) | |
e89065a1 | 2349 | { |
6c66f733 JJ |
2350 | tree temp; |
2351 | gimple def_stmt = SSA_NAME_DEF_STMT (arg); | |
2352 | /* In simple cases we can look through PHI nodes, | |
2353 | but we have to be careful with loops. | |
2354 | See PR49073. */ | |
2355 | if (! dom_info_available_p (CDI_DOMINATORS) | |
2356 | || gimple_bb (def_stmt) == gimple_bb (stmt) | |
2357 | || dominated_by_p (CDI_DOMINATORS, | |
2358 | gimple_bb (def_stmt), | |
2359 | gimple_bb (stmt))) | |
2360 | return NULL_TREE; | |
2361 | temp = or_var_with_comparison (arg, invert, code2, | |
2362 | op2a, op2b); | |
e89065a1 SL |
2363 | if (!temp) |
2364 | return NULL_TREE; | |
2365 | else if (!result) | |
2366 | result = temp; | |
2367 | else if (!same_bool_result_p (result, temp)) | |
2368 | return NULL_TREE; | |
2369 | } | |
2370 | else | |
2371 | return NULL_TREE; | |
2372 | } | |
2373 | return result; | |
2374 | } | |
2375 | ||
2376 | default: | |
2377 | break; | |
2378 | } | |
2379 | } | |
2380 | return NULL_TREE; | |
2381 | } | |
2382 | ||
2383 | /* Try to simplify the OR of two comparisons, specified by | |
2384 | (OP1A CODE1 OP1B) and (OP2B CODE2 OP2B), respectively. | |
2385 | If this can be simplified to a single expression (without requiring | |
2386 | introducing more SSA variables to hold intermediate values), | |
2387 | return the resulting tree. Otherwise return NULL_TREE. | |
2388 | If the result expression is non-null, it has boolean type. */ | |
2389 | ||
2390 | tree | |
2391 | maybe_fold_or_comparisons (enum tree_code code1, tree op1a, tree op1b, | |
2392 | enum tree_code code2, tree op2a, tree op2b) | |
2393 | { | |
2394 | tree t = or_comparisons_1 (code1, op1a, op1b, code2, op2a, op2b); | |
2395 | if (t) | |
2396 | return t; | |
2397 | else | |
2398 | return or_comparisons_1 (code2, op2a, op2b, code1, op1a, op1b); | |
2399 | } | |
cfef45c8 RG |
2400 | |
2401 | ||
2402 | /* Fold STMT to a constant using VALUEIZE to valueize SSA names. | |
2403 | ||
2404 | Either NULL_TREE, a simplified but non-constant or a constant | |
2405 | is returned. | |
2406 | ||
2407 | ??? This should go into a gimple-fold-inline.h file to be eventually | |
2408 | privatized with the single valueize function used in the various TUs | |
2409 | to avoid the indirect function call overhead. */ | |
2410 | ||
2411 | tree | |
2412 | gimple_fold_stmt_to_constant_1 (gimple stmt, tree (*valueize) (tree)) | |
2413 | { | |
2414 | location_t loc = gimple_location (stmt); | |
2415 | switch (gimple_code (stmt)) | |
2416 | { | |
2417 | case GIMPLE_ASSIGN: | |
2418 | { | |
2419 | enum tree_code subcode = gimple_assign_rhs_code (stmt); | |
2420 | ||
2421 | switch (get_gimple_rhs_class (subcode)) | |
2422 | { | |
2423 | case GIMPLE_SINGLE_RHS: | |
2424 | { | |
2425 | tree rhs = gimple_assign_rhs1 (stmt); | |
2426 | enum tree_code_class kind = TREE_CODE_CLASS (subcode); | |
2427 | ||
2428 | if (TREE_CODE (rhs) == SSA_NAME) | |
2429 | { | |
2430 | /* If the RHS is an SSA_NAME, return its known constant value, | |
2431 | if any. */ | |
2432 | return (*valueize) (rhs); | |
2433 | } | |
2434 | /* Handle propagating invariant addresses into address | |
2435 | operations. */ | |
2436 | else if (TREE_CODE (rhs) == ADDR_EXPR | |
2437 | && !is_gimple_min_invariant (rhs)) | |
2438 | { | |
2439 | HOST_WIDE_INT offset; | |
2440 | tree base; | |
2441 | base = get_addr_base_and_unit_offset_1 (TREE_OPERAND (rhs, 0), | |
2442 | &offset, | |
2443 | valueize); | |
2444 | if (base | |
2445 | && (CONSTANT_CLASS_P (base) | |
2446 | || decl_address_invariant_p (base))) | |
2447 | return build_invariant_address (TREE_TYPE (rhs), | |
2448 | base, offset); | |
2449 | } | |
2450 | else if (TREE_CODE (rhs) == CONSTRUCTOR | |
2451 | && TREE_CODE (TREE_TYPE (rhs)) == VECTOR_TYPE | |
2452 | && (CONSTRUCTOR_NELTS (rhs) | |
2453 | == TYPE_VECTOR_SUBPARTS (TREE_TYPE (rhs)))) | |
2454 | { | |
2455 | unsigned i; | |
2456 | tree val, list; | |
2457 | ||
2458 | list = NULL_TREE; | |
2459 | FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (rhs), i, val) | |
2460 | { | |
2461 | val = (*valueize) (val); | |
2462 | if (TREE_CODE (val) == INTEGER_CST | |
2463 | || TREE_CODE (val) == REAL_CST | |
2464 | || TREE_CODE (val) == FIXED_CST) | |
2465 | list = tree_cons (NULL_TREE, val, list); | |
2466 | else | |
2467 | return NULL_TREE; | |
2468 | } | |
2469 | ||
2470 | return build_vector (TREE_TYPE (rhs), nreverse (list)); | |
2471 | } | |
2472 | ||
2473 | if (kind == tcc_reference) | |
2474 | { | |
2475 | if ((TREE_CODE (rhs) == VIEW_CONVERT_EXPR | |
2476 | || TREE_CODE (rhs) == REALPART_EXPR | |
2477 | || TREE_CODE (rhs) == IMAGPART_EXPR) | |
2478 | && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME) | |
2479 | { | |
2480 | tree val = (*valueize) (TREE_OPERAND (rhs, 0)); | |
2481 | return fold_unary_loc (EXPR_LOCATION (rhs), | |
2482 | TREE_CODE (rhs), | |
2483 | TREE_TYPE (rhs), val); | |
2484 | } | |
2485 | else if (TREE_CODE (rhs) == BIT_FIELD_REF | |
2486 | && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME) | |
2487 | { | |
2488 | tree val = (*valueize) (TREE_OPERAND (rhs, 0)); | |
2489 | return fold_ternary_loc (EXPR_LOCATION (rhs), | |
2490 | TREE_CODE (rhs), | |
2491 | TREE_TYPE (rhs), val, | |
2492 | TREE_OPERAND (rhs, 1), | |
2493 | TREE_OPERAND (rhs, 2)); | |
2494 | } | |
2495 | else if (TREE_CODE (rhs) == MEM_REF | |
2496 | && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME) | |
2497 | { | |
2498 | tree val = (*valueize) (TREE_OPERAND (rhs, 0)); | |
2499 | if (TREE_CODE (val) == ADDR_EXPR | |
2500 | && is_gimple_min_invariant (val)) | |
2501 | { | |
2502 | tree tem = fold_build2 (MEM_REF, TREE_TYPE (rhs), | |
2503 | unshare_expr (val), | |
2504 | TREE_OPERAND (rhs, 1)); | |
2505 | if (tem) | |
2506 | rhs = tem; | |
2507 | } | |
2508 | } | |
2509 | return fold_const_aggregate_ref_1 (rhs, valueize); | |
2510 | } | |
2511 | else if (kind == tcc_declaration) | |
2512 | return get_symbol_constant_value (rhs); | |
2513 | return rhs; | |
2514 | } | |
2515 | ||
2516 | case GIMPLE_UNARY_RHS: | |
2517 | { | |
2518 | /* Handle unary operators that can appear in GIMPLE form. | |
2519 | Note that we know the single operand must be a constant, | |
2520 | so this should almost always return a simplified RHS. */ | |
315f5f1b | 2521 | tree lhs = gimple_assign_lhs (stmt); |
cfef45c8 RG |
2522 | tree op0 = (*valueize) (gimple_assign_rhs1 (stmt)); |
2523 | ||
2524 | /* Conversions are useless for CCP purposes if they are | |
2525 | value-preserving. Thus the restrictions that | |
315f5f1b RG |
2526 | useless_type_conversion_p places for restrict qualification |
2527 | of pointer types should not apply here. | |
2528 | Substitution later will only substitute to allowed places. */ | |
cfef45c8 RG |
2529 | if (CONVERT_EXPR_CODE_P (subcode) |
2530 | && POINTER_TYPE_P (TREE_TYPE (lhs)) | |
315f5f1b RG |
2531 | && POINTER_TYPE_P (TREE_TYPE (op0)) |
2532 | && (TYPE_ADDR_SPACE (TREE_TYPE (lhs)) | |
2533 | == TYPE_ADDR_SPACE (TREE_TYPE (op0)))) | |
2534 | return op0; | |
cfef45c8 RG |
2535 | |
2536 | return | |
2537 | fold_unary_ignore_overflow_loc (loc, subcode, | |
2538 | gimple_expr_type (stmt), op0); | |
2539 | } | |
2540 | ||
2541 | case GIMPLE_BINARY_RHS: | |
2542 | { | |
2543 | /* Handle binary operators that can appear in GIMPLE form. */ | |
2544 | tree op0 = (*valueize) (gimple_assign_rhs1 (stmt)); | |
2545 | tree op1 = (*valueize) (gimple_assign_rhs2 (stmt)); | |
2546 | ||
2547 | /* Translate &x + CST into an invariant form suitable for | |
2548 | further propagation. */ | |
2549 | if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR | |
2550 | && TREE_CODE (op0) == ADDR_EXPR | |
2551 | && TREE_CODE (op1) == INTEGER_CST) | |
2552 | { | |
2553 | tree off = fold_convert (ptr_type_node, op1); | |
4d59a001 RG |
2554 | return build_fold_addr_expr_loc |
2555 | (loc, | |
2556 | fold_build2 (MEM_REF, | |
cfef45c8 RG |
2557 | TREE_TYPE (TREE_TYPE (op0)), |
2558 | unshare_expr (op0), off)); | |
2559 | } | |
2560 | ||
2561 | return fold_binary_loc (loc, subcode, | |
2562 | gimple_expr_type (stmt), op0, op1); | |
2563 | } | |
2564 | ||
2565 | case GIMPLE_TERNARY_RHS: | |
2566 | { | |
2567 | /* Handle ternary operators that can appear in GIMPLE form. */ | |
2568 | tree op0 = (*valueize) (gimple_assign_rhs1 (stmt)); | |
2569 | tree op1 = (*valueize) (gimple_assign_rhs2 (stmt)); | |
2570 | tree op2 = (*valueize) (gimple_assign_rhs3 (stmt)); | |
2571 | ||
2572 | return fold_ternary_loc (loc, subcode, | |
2573 | gimple_expr_type (stmt), op0, op1, op2); | |
2574 | } | |
2575 | ||
2576 | default: | |
2577 | gcc_unreachable (); | |
2578 | } | |
2579 | } | |
2580 | ||
2581 | case GIMPLE_CALL: | |
2582 | { | |
25583c4f RS |
2583 | tree fn; |
2584 | ||
2585 | if (gimple_call_internal_p (stmt)) | |
2586 | /* No folding yet for these functions. */ | |
2587 | return NULL_TREE; | |
2588 | ||
2589 | fn = (*valueize) (gimple_call_fn (stmt)); | |
cfef45c8 RG |
2590 | if (TREE_CODE (fn) == ADDR_EXPR |
2591 | && TREE_CODE (TREE_OPERAND (fn, 0)) == FUNCTION_DECL | |
2592 | && DECL_BUILT_IN (TREE_OPERAND (fn, 0))) | |
2593 | { | |
2594 | tree *args = XALLOCAVEC (tree, gimple_call_num_args (stmt)); | |
2595 | tree call, retval; | |
2596 | unsigned i; | |
2597 | for (i = 0; i < gimple_call_num_args (stmt); ++i) | |
2598 | args[i] = (*valueize) (gimple_call_arg (stmt, i)); | |
2599 | call = build_call_array_loc (loc, | |
2600 | gimple_call_return_type (stmt), | |
2601 | fn, gimple_call_num_args (stmt), args); | |
2602 | retval = fold_call_expr (EXPR_LOCATION (call), call, false); | |
2603 | if (retval) | |
2604 | /* fold_call_expr wraps the result inside a NOP_EXPR. */ | |
2605 | STRIP_NOPS (retval); | |
2606 | return retval; | |
2607 | } | |
2608 | return NULL_TREE; | |
2609 | } | |
2610 | ||
2611 | default: | |
2612 | return NULL_TREE; | |
2613 | } | |
2614 | } | |
2615 | ||
2616 | /* Fold STMT to a constant using VALUEIZE to valueize SSA names. | |
2617 | Returns NULL_TREE if folding to a constant is not possible, otherwise | |
2618 | returns a constant according to is_gimple_min_invariant. */ | |
2619 | ||
2620 | tree | |
2621 | gimple_fold_stmt_to_constant (gimple stmt, tree (*valueize) (tree)) | |
2622 | { | |
2623 | tree res = gimple_fold_stmt_to_constant_1 (stmt, valueize); | |
2624 | if (res && is_gimple_min_invariant (res)) | |
2625 | return res; | |
2626 | return NULL_TREE; | |
2627 | } | |
2628 | ||
2629 | ||
2630 | /* The following set of functions are supposed to fold references using | |
2631 | their constant initializers. */ | |
2632 | ||
2633 | static tree fold_ctor_reference (tree type, tree ctor, | |
2634 | unsigned HOST_WIDE_INT offset, | |
2635 | unsigned HOST_WIDE_INT size); | |
2636 | ||
2637 | /* See if we can find constructor defining value of BASE. | |
2638 | When we know the consructor with constant offset (such as | |
2639 | base is array[40] and we do know constructor of array), then | |
2640 | BIT_OFFSET is adjusted accordingly. | |
2641 | ||
2642 | As a special case, return error_mark_node when constructor | |
2643 | is not explicitly available, but it is known to be zero | |
2644 | such as 'static const int a;'. */ | |
2645 | static tree | |
2646 | get_base_constructor (tree base, HOST_WIDE_INT *bit_offset, | |
2647 | tree (*valueize)(tree)) | |
2648 | { | |
2649 | HOST_WIDE_INT bit_offset2, size, max_size; | |
2650 | if (TREE_CODE (base) == MEM_REF) | |
2651 | { | |
2652 | if (!integer_zerop (TREE_OPERAND (base, 1))) | |
2653 | { | |
2654 | if (!host_integerp (TREE_OPERAND (base, 1), 0)) | |
2655 | return NULL_TREE; | |
2656 | *bit_offset += (mem_ref_offset (base).low | |
2657 | * BITS_PER_UNIT); | |
2658 | } | |
2659 | ||
2660 | if (valueize | |
2661 | && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME) | |
2662 | base = valueize (TREE_OPERAND (base, 0)); | |
2663 | if (!base || TREE_CODE (base) != ADDR_EXPR) | |
2664 | return NULL_TREE; | |
2665 | base = TREE_OPERAND (base, 0); | |
2666 | } | |
2667 | ||
2668 | /* Get a CONSTRUCTOR. If BASE is a VAR_DECL, get its | |
2669 | DECL_INITIAL. If BASE is a nested reference into another | |
2670 | ARRAY_REF or COMPONENT_REF, make a recursive call to resolve | |
2671 | the inner reference. */ | |
2672 | switch (TREE_CODE (base)) | |
2673 | { | |
2674 | case VAR_DECL: | |
2675 | if (!const_value_known_p (base)) | |
2676 | return NULL_TREE; | |
2677 | ||
2678 | /* Fallthru. */ | |
2679 | case CONST_DECL: | |
2680 | if (!DECL_INITIAL (base) | |
2681 | && (TREE_STATIC (base) || DECL_EXTERNAL (base))) | |
2682 | return error_mark_node; | |
2683 | return DECL_INITIAL (base); | |
2684 | ||
2685 | case ARRAY_REF: | |
2686 | case COMPONENT_REF: | |
2687 | base = get_ref_base_and_extent (base, &bit_offset2, &size, &max_size); | |
2688 | if (max_size == -1 || size != max_size) | |
2689 | return NULL_TREE; | |
2690 | *bit_offset += bit_offset2; | |
2691 | return get_base_constructor (base, bit_offset, valueize); | |
2692 | ||
2693 | case STRING_CST: | |
2694 | case CONSTRUCTOR: | |
2695 | return base; | |
2696 | ||
2697 | default: | |
2698 | return NULL_TREE; | |
2699 | } | |
2700 | } | |
2701 | ||
2702 | /* CTOR is STRING_CST. Fold reference of type TYPE and size SIZE | |
2703 | to the memory at bit OFFSET. | |
2704 | ||
2705 | We do only simple job of folding byte accesses. */ | |
2706 | ||
2707 | static tree | |
2708 | fold_string_cst_ctor_reference (tree type, tree ctor, | |
2709 | unsigned HOST_WIDE_INT offset, | |
2710 | unsigned HOST_WIDE_INT size) | |
2711 | { | |
2712 | if (INTEGRAL_TYPE_P (type) | |
2713 | && (TYPE_MODE (type) | |
2714 | == TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) | |
2715 | && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) | |
2716 | == MODE_INT) | |
2717 | && GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) == 1 | |
2718 | && size == BITS_PER_UNIT | |
2719 | && !(offset % BITS_PER_UNIT)) | |
2720 | { | |
2721 | offset /= BITS_PER_UNIT; | |
2722 | if (offset < (unsigned HOST_WIDE_INT) TREE_STRING_LENGTH (ctor)) | |
2723 | return build_int_cst_type (type, (TREE_STRING_POINTER (ctor) | |
2724 | [offset])); | |
2725 | /* Folding | |
2726 | const char a[20]="hello"; | |
2727 | return a[10]; | |
2728 | ||
2729 | might lead to offset greater than string length. In this case we | |
2730 | know value is either initialized to 0 or out of bounds. Return 0 | |
2731 | in both cases. */ | |
2732 | return build_zero_cst (type); | |
2733 | } | |
2734 | return NULL_TREE; | |
2735 | } | |
2736 | ||
2737 | /* CTOR is CONSTRUCTOR of an array type. Fold reference of type TYPE and size | |
2738 | SIZE to the memory at bit OFFSET. */ | |
2739 | ||
2740 | static tree | |
2741 | fold_array_ctor_reference (tree type, tree ctor, | |
2742 | unsigned HOST_WIDE_INT offset, | |
2743 | unsigned HOST_WIDE_INT size) | |
2744 | { | |
2745 | unsigned HOST_WIDE_INT cnt; | |
2746 | tree cfield, cval; | |
2747 | double_int low_bound, elt_size; | |
2748 | double_int index, max_index; | |
2749 | double_int access_index; | |
eb8f1123 | 2750 | tree domain_type = NULL_TREE; |
cfef45c8 RG |
2751 | HOST_WIDE_INT inner_offset; |
2752 | ||
2753 | /* Compute low bound and elt size. */ | |
eb8f1123 RG |
2754 | if (TREE_CODE (TREE_TYPE (ctor)) == ARRAY_TYPE) |
2755 | domain_type = TYPE_DOMAIN (TREE_TYPE (ctor)); | |
cfef45c8 RG |
2756 | if (domain_type && TYPE_MIN_VALUE (domain_type)) |
2757 | { | |
2758 | /* Static constructors for variably sized objects makes no sense. */ | |
2759 | gcc_assert (TREE_CODE (TYPE_MIN_VALUE (domain_type)) == INTEGER_CST); | |
2760 | low_bound = tree_to_double_int (TYPE_MIN_VALUE (domain_type)); | |
2761 | } | |
2762 | else | |
2763 | low_bound = double_int_zero; | |
2764 | /* Static constructors for variably sized objects makes no sense. */ | |
2765 | gcc_assert (TREE_CODE(TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (ctor)))) | |
2766 | == INTEGER_CST); | |
2767 | elt_size = | |
2768 | tree_to_double_int (TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (ctor)))); | |
2769 | ||
2770 | ||
2771 | /* We can handle only constantly sized accesses that are known to not | |
2772 | be larger than size of array element. */ | |
2773 | if (!TYPE_SIZE_UNIT (type) | |
2774 | || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST | |
2775 | || double_int_cmp (elt_size, | |
2776 | tree_to_double_int (TYPE_SIZE_UNIT (type)), 0) < 0) | |
2777 | return NULL_TREE; | |
2778 | ||
2779 | /* Compute the array index we look for. */ | |
2780 | access_index = double_int_udiv (uhwi_to_double_int (offset / BITS_PER_UNIT), | |
2781 | elt_size, TRUNC_DIV_EXPR); | |
2782 | access_index = double_int_add (access_index, low_bound); | |
2783 | ||
2784 | /* And offset within the access. */ | |
2785 | inner_offset = offset % (double_int_to_uhwi (elt_size) * BITS_PER_UNIT); | |
2786 | ||
2787 | /* See if the array field is large enough to span whole access. We do not | |
2788 | care to fold accesses spanning multiple array indexes. */ | |
2789 | if (inner_offset + size > double_int_to_uhwi (elt_size) * BITS_PER_UNIT) | |
2790 | return NULL_TREE; | |
2791 | ||
2792 | index = double_int_sub (low_bound, double_int_one); | |
2793 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, cval) | |
2794 | { | |
2795 | /* Array constructor might explicitely set index, or specify range | |
2796 | or leave index NULL meaning that it is next index after previous | |
2797 | one. */ | |
2798 | if (cfield) | |
2799 | { | |
2800 | if (TREE_CODE (cfield) == INTEGER_CST) | |
2801 | max_index = index = tree_to_double_int (cfield); | |
2802 | else | |
2803 | { | |
2804 | gcc_assert (TREE_CODE (cfield) == RANGE_EXPR); | |
2805 | index = tree_to_double_int (TREE_OPERAND (cfield, 0)); | |
2806 | max_index = tree_to_double_int (TREE_OPERAND (cfield, 1)); | |
2807 | } | |
2808 | } | |
2809 | else | |
2810 | max_index = index = double_int_add (index, double_int_one); | |
2811 | ||
2812 | /* Do we have match? */ | |
2813 | if (double_int_cmp (access_index, index, 1) >= 0 | |
2814 | && double_int_cmp (access_index, max_index, 1) <= 0) | |
2815 | return fold_ctor_reference (type, cval, inner_offset, size); | |
2816 | } | |
2817 | /* When memory is not explicitely mentioned in constructor, | |
2818 | it is 0 (or out of range). */ | |
2819 | return build_zero_cst (type); | |
2820 | } | |
2821 | ||
2822 | /* CTOR is CONSTRUCTOR of an aggregate or vector. | |
2823 | Fold reference of type TYPE and size SIZE to the memory at bit OFFSET. */ | |
2824 | ||
2825 | static tree | |
2826 | fold_nonarray_ctor_reference (tree type, tree ctor, | |
2827 | unsigned HOST_WIDE_INT offset, | |
2828 | unsigned HOST_WIDE_INT size) | |
2829 | { | |
2830 | unsigned HOST_WIDE_INT cnt; | |
2831 | tree cfield, cval; | |
2832 | ||
2833 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, | |
2834 | cval) | |
2835 | { | |
2836 | tree byte_offset = DECL_FIELD_OFFSET (cfield); | |
2837 | tree field_offset = DECL_FIELD_BIT_OFFSET (cfield); | |
2838 | tree field_size = DECL_SIZE (cfield); | |
2839 | double_int bitoffset; | |
2840 | double_int byte_offset_cst = tree_to_double_int (byte_offset); | |
2841 | double_int bits_per_unit_cst = uhwi_to_double_int (BITS_PER_UNIT); | |
b8b2b009 | 2842 | double_int bitoffset_end, access_end; |
cfef45c8 RG |
2843 | |
2844 | /* Variable sized objects in static constructors makes no sense, | |
2845 | but field_size can be NULL for flexible array members. */ | |
2846 | gcc_assert (TREE_CODE (field_offset) == INTEGER_CST | |
2847 | && TREE_CODE (byte_offset) == INTEGER_CST | |
2848 | && (field_size != NULL_TREE | |
2849 | ? TREE_CODE (field_size) == INTEGER_CST | |
2850 | : TREE_CODE (TREE_TYPE (cfield)) == ARRAY_TYPE)); | |
2851 | ||
2852 | /* Compute bit offset of the field. */ | |
2853 | bitoffset = double_int_add (tree_to_double_int (field_offset), | |
2854 | double_int_mul (byte_offset_cst, | |
2855 | bits_per_unit_cst)); | |
2856 | /* Compute bit offset where the field ends. */ | |
2857 | if (field_size != NULL_TREE) | |
2858 | bitoffset_end = double_int_add (bitoffset, | |
2859 | tree_to_double_int (field_size)); | |
2860 | else | |
2861 | bitoffset_end = double_int_zero; | |
2862 | ||
b8b2b009 JJ |
2863 | access_end = double_int_add (uhwi_to_double_int (offset), |
2864 | uhwi_to_double_int (size)); | |
2865 | ||
2866 | /* Is there any overlap between [OFFSET, OFFSET+SIZE) and | |
2867 | [BITOFFSET, BITOFFSET_END)? */ | |
2868 | if (double_int_cmp (access_end, bitoffset, 0) > 0 | |
cfef45c8 RG |
2869 | && (field_size == NULL_TREE |
2870 | || double_int_cmp (uhwi_to_double_int (offset), | |
2871 | bitoffset_end, 0) < 0)) | |
2872 | { | |
cfef45c8 RG |
2873 | double_int inner_offset = double_int_sub (uhwi_to_double_int (offset), |
2874 | bitoffset); | |
2875 | /* We do have overlap. Now see if field is large enough to | |
2876 | cover the access. Give up for accesses spanning multiple | |
2877 | fields. */ | |
2878 | if (double_int_cmp (access_end, bitoffset_end, 0) > 0) | |
2879 | return NULL_TREE; | |
b8b2b009 JJ |
2880 | if (double_int_cmp (uhwi_to_double_int (offset), bitoffset, 0) < 0) |
2881 | return NULL_TREE; | |
cfef45c8 RG |
2882 | return fold_ctor_reference (type, cval, |
2883 | double_int_to_uhwi (inner_offset), size); | |
2884 | } | |
2885 | } | |
2886 | /* When memory is not explicitely mentioned in constructor, it is 0. */ | |
2887 | return build_zero_cst (type); | |
2888 | } | |
2889 | ||
2890 | /* CTOR is value initializing memory, fold reference of type TYPE and size SIZE | |
2891 | to the memory at bit OFFSET. */ | |
2892 | ||
2893 | static tree | |
2894 | fold_ctor_reference (tree type, tree ctor, unsigned HOST_WIDE_INT offset, | |
2895 | unsigned HOST_WIDE_INT size) | |
2896 | { | |
2897 | tree ret; | |
2898 | ||
2899 | /* We found the field with exact match. */ | |
2900 | if (useless_type_conversion_p (type, TREE_TYPE (ctor)) | |
2901 | && !offset) | |
2902 | return canonicalize_constructor_val (ctor); | |
2903 | ||
2904 | /* We are at the end of walk, see if we can view convert the | |
2905 | result. */ | |
2906 | if (!AGGREGATE_TYPE_P (TREE_TYPE (ctor)) && !offset | |
2907 | /* VIEW_CONVERT_EXPR is defined only for matching sizes. */ | |
2908 | && operand_equal_p (TYPE_SIZE (type), | |
2909 | TYPE_SIZE (TREE_TYPE (ctor)), 0)) | |
2910 | { | |
2911 | ret = canonicalize_constructor_val (ctor); | |
2912 | ret = fold_unary (VIEW_CONVERT_EXPR, type, ret); | |
2913 | if (ret) | |
2914 | STRIP_NOPS (ret); | |
2915 | return ret; | |
2916 | } | |
2917 | if (TREE_CODE (ctor) == STRING_CST) | |
2918 | return fold_string_cst_ctor_reference (type, ctor, offset, size); | |
2919 | if (TREE_CODE (ctor) == CONSTRUCTOR) | |
2920 | { | |
2921 | ||
eb8f1123 RG |
2922 | if (TREE_CODE (TREE_TYPE (ctor)) == ARRAY_TYPE |
2923 | || TREE_CODE (TREE_TYPE (ctor)) == VECTOR_TYPE) | |
cfef45c8 RG |
2924 | return fold_array_ctor_reference (type, ctor, offset, size); |
2925 | else | |
2926 | return fold_nonarray_ctor_reference (type, ctor, offset, size); | |
2927 | } | |
2928 | ||
2929 | return NULL_TREE; | |
2930 | } | |
2931 | ||
2932 | /* Return the tree representing the element referenced by T if T is an | |
2933 | ARRAY_REF or COMPONENT_REF into constant aggregates valuezing SSA | |
2934 | names using VALUEIZE. Return NULL_TREE otherwise. */ | |
2935 | ||
2936 | tree | |
2937 | fold_const_aggregate_ref_1 (tree t, tree (*valueize) (tree)) | |
2938 | { | |
2939 | tree ctor, idx, base; | |
2940 | HOST_WIDE_INT offset, size, max_size; | |
2941 | tree tem; | |
2942 | ||
f8a7df45 RG |
2943 | if (TREE_THIS_VOLATILE (t)) |
2944 | return NULL_TREE; | |
2945 | ||
cfef45c8 RG |
2946 | if (TREE_CODE_CLASS (TREE_CODE (t)) == tcc_declaration) |
2947 | return get_symbol_constant_value (t); | |
2948 | ||
2949 | tem = fold_read_from_constant_string (t); | |
2950 | if (tem) | |
2951 | return tem; | |
2952 | ||
2953 | switch (TREE_CODE (t)) | |
2954 | { | |
2955 | case ARRAY_REF: | |
2956 | case ARRAY_RANGE_REF: | |
2957 | /* Constant indexes are handled well by get_base_constructor. | |
2958 | Only special case variable offsets. | |
2959 | FIXME: This code can't handle nested references with variable indexes | |
2960 | (they will be handled only by iteration of ccp). Perhaps we can bring | |
2961 | get_ref_base_and_extent here and make it use a valueize callback. */ | |
2962 | if (TREE_CODE (TREE_OPERAND (t, 1)) == SSA_NAME | |
2963 | && valueize | |
2964 | && (idx = (*valueize) (TREE_OPERAND (t, 1))) | |
2965 | && host_integerp (idx, 0)) | |
2966 | { | |
2967 | tree low_bound, unit_size; | |
2968 | ||
2969 | /* If the resulting bit-offset is constant, track it. */ | |
2970 | if ((low_bound = array_ref_low_bound (t), | |
2971 | host_integerp (low_bound, 0)) | |
2972 | && (unit_size = array_ref_element_size (t), | |
2973 | host_integerp (unit_size, 1))) | |
2974 | { | |
2975 | offset = TREE_INT_CST_LOW (idx); | |
2976 | offset -= TREE_INT_CST_LOW (low_bound); | |
2977 | offset *= TREE_INT_CST_LOW (unit_size); | |
2978 | offset *= BITS_PER_UNIT; | |
2979 | ||
2980 | base = TREE_OPERAND (t, 0); | |
2981 | ctor = get_base_constructor (base, &offset, valueize); | |
2982 | /* Empty constructor. Always fold to 0. */ | |
2983 | if (ctor == error_mark_node) | |
2984 | return build_zero_cst (TREE_TYPE (t)); | |
2985 | /* Out of bound array access. Value is undefined, | |
2986 | but don't fold. */ | |
2987 | if (offset < 0) | |
2988 | return NULL_TREE; | |
2989 | /* We can not determine ctor. */ | |
2990 | if (!ctor) | |
2991 | return NULL_TREE; | |
2992 | return fold_ctor_reference (TREE_TYPE (t), ctor, offset, | |
2993 | TREE_INT_CST_LOW (unit_size) | |
2994 | * BITS_PER_UNIT); | |
2995 | } | |
2996 | } | |
2997 | /* Fallthru. */ | |
2998 | ||
2999 | case COMPONENT_REF: | |
3000 | case BIT_FIELD_REF: | |
3001 | case TARGET_MEM_REF: | |
3002 | case MEM_REF: | |
3003 | base = get_ref_base_and_extent (t, &offset, &size, &max_size); | |
3004 | ctor = get_base_constructor (base, &offset, valueize); | |
3005 | ||
3006 | /* Empty constructor. Always fold to 0. */ | |
3007 | if (ctor == error_mark_node) | |
3008 | return build_zero_cst (TREE_TYPE (t)); | |
3009 | /* We do not know precise address. */ | |
3010 | if (max_size == -1 || max_size != size) | |
3011 | return NULL_TREE; | |
3012 | /* We can not determine ctor. */ | |
3013 | if (!ctor) | |
3014 | return NULL_TREE; | |
3015 | ||
3016 | /* Out of bound array access. Value is undefined, but don't fold. */ | |
3017 | if (offset < 0) | |
3018 | return NULL_TREE; | |
3019 | ||
3020 | return fold_ctor_reference (TREE_TYPE (t), ctor, offset, size); | |
3021 | ||
3022 | case REALPART_EXPR: | |
3023 | case IMAGPART_EXPR: | |
3024 | { | |
3025 | tree c = fold_const_aggregate_ref_1 (TREE_OPERAND (t, 0), valueize); | |
3026 | if (c && TREE_CODE (c) == COMPLEX_CST) | |
3027 | return fold_build1_loc (EXPR_LOCATION (t), | |
3028 | TREE_CODE (t), TREE_TYPE (t), c); | |
3029 | break; | |
3030 | } | |
3031 | ||
3032 | default: | |
3033 | break; | |
3034 | } | |
3035 | ||
3036 | return NULL_TREE; | |
3037 | } | |
3038 | ||
3039 | tree | |
3040 | fold_const_aggregate_ref (tree t) | |
3041 | { | |
3042 | return fold_const_aggregate_ref_1 (t, NULL); | |
3043 | } | |
06bc3ec7 | 3044 | |
81fa35bd MJ |
3045 | /* Return a declaration of a function which an OBJ_TYPE_REF references. TOKEN |
3046 | is integer form of OBJ_TYPE_REF_TOKEN of the reference expression. | |
3047 | KNOWN_BINFO carries the binfo describing the true type of | |
3048 | OBJ_TYPE_REF_OBJECT(REF). */ | |
3049 | ||
3050 | tree | |
3051 | gimple_get_virt_method_for_binfo (HOST_WIDE_INT token, tree known_binfo) | |
3052 | { | |
3053 | unsigned HOST_WIDE_INT offset, size; | |
3054 | tree v, fn; | |
3055 | ||
3056 | v = BINFO_VTABLE (known_binfo); | |
3057 | /* If there is no virtual methods table, leave the OBJ_TYPE_REF alone. */ | |
3058 | if (!v) | |
3059 | return NULL_TREE; | |
3060 | ||
3061 | if (TREE_CODE (v) == POINTER_PLUS_EXPR) | |
3062 | { | |
3063 | offset = tree_low_cst (TREE_OPERAND (v, 1), 1) * BITS_PER_UNIT; | |
3064 | v = TREE_OPERAND (v, 0); | |
3065 | } | |
3066 | else | |
3067 | offset = 0; | |
3068 | ||
3069 | if (TREE_CODE (v) != ADDR_EXPR) | |
3070 | return NULL_TREE; | |
3071 | v = TREE_OPERAND (v, 0); | |
3072 | ||
3073 | if (TREE_CODE (v) != VAR_DECL | |
3074 | || !DECL_VIRTUAL_P (v) | |
5548ca35 JH |
3075 | || !DECL_INITIAL (v) |
3076 | || DECL_INITIAL (v) == error_mark_node) | |
81fa35bd MJ |
3077 | return NULL_TREE; |
3078 | gcc_checking_assert (TREE_CODE (TREE_TYPE (v)) == ARRAY_TYPE); | |
3079 | size = tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (v))), 1); | |
3080 | offset += token * size; | |
3081 | fn = fold_ctor_reference (TREE_TYPE (TREE_TYPE (v)), DECL_INITIAL (v), | |
3082 | offset, size); | |
3083 | if (!fn) | |
3084 | return NULL_TREE; | |
3085 | gcc_assert (TREE_CODE (fn) == ADDR_EXPR | |
3086 | || TREE_CODE (fn) == FDESC_EXPR); | |
3087 | fn = TREE_OPERAND (fn, 0); | |
3088 | gcc_assert (TREE_CODE (fn) == FUNCTION_DECL); | |
3089 | ||
3090 | /* When cgraph node is missing and function is not public, we cannot | |
3091 | devirtualize. This can happen in WHOPR when the actual method | |
3092 | ends up in other partition, because we found devirtualization | |
3093 | possibility too late. */ | |
3094 | if (!can_refer_decl_in_current_unit_p (fn)) | |
3095 | return NULL_TREE; | |
3096 | ||
3097 | return fn; | |
3098 | } | |
3099 | ||
06bc3ec7 BS |
3100 | /* Return true iff VAL is a gimple expression that is known to be |
3101 | non-negative. Restricted to floating-point inputs. */ | |
3102 | ||
3103 | bool | |
3104 | gimple_val_nonnegative_real_p (tree val) | |
3105 | { | |
3106 | gimple def_stmt; | |
3107 | ||
3108 | gcc_assert (val && SCALAR_FLOAT_TYPE_P (TREE_TYPE (val))); | |
3109 | ||
3110 | /* Use existing logic for non-gimple trees. */ | |
3111 | if (tree_expr_nonnegative_p (val)) | |
3112 | return true; | |
3113 | ||
3114 | if (TREE_CODE (val) != SSA_NAME) | |
3115 | return false; | |
3116 | ||
3117 | /* Currently we look only at the immediately defining statement | |
3118 | to make this determination, since recursion on defining | |
3119 | statements of operands can lead to quadratic behavior in the | |
3120 | worst case. This is expected to catch almost all occurrences | |
3121 | in practice. It would be possible to implement limited-depth | |
3122 | recursion if important cases are lost. Alternatively, passes | |
3123 | that need this information (such as the pow/powi lowering code | |
3124 | in the cse_sincos pass) could be revised to provide it through | |
3125 | dataflow propagation. */ | |
3126 | ||
3127 | def_stmt = SSA_NAME_DEF_STMT (val); | |
3128 | ||
3129 | if (is_gimple_assign (def_stmt)) | |
3130 | { | |
3131 | tree op0, op1; | |
3132 | ||
3133 | /* See fold-const.c:tree_expr_nonnegative_p for additional | |
3134 | cases that could be handled with recursion. */ | |
3135 | ||
3136 | switch (gimple_assign_rhs_code (def_stmt)) | |
3137 | { | |
3138 | case ABS_EXPR: | |
3139 | /* Always true for floating-point operands. */ | |
3140 | return true; | |
3141 | ||
3142 | case MULT_EXPR: | |
3143 | /* True if the two operands are identical (since we are | |
3144 | restricted to floating-point inputs). */ | |
3145 | op0 = gimple_assign_rhs1 (def_stmt); | |
3146 | op1 = gimple_assign_rhs2 (def_stmt); | |
3147 | ||
3148 | if (op0 == op1 | |
3149 | || operand_equal_p (op0, op1, 0)) | |
3150 | return true; | |
3151 | ||
3152 | default: | |
3153 | return false; | |
3154 | } | |
3155 | } | |
3156 | else if (is_gimple_call (def_stmt)) | |
3157 | { | |
3158 | tree fndecl = gimple_call_fndecl (def_stmt); | |
3159 | if (fndecl | |
3160 | && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL) | |
3161 | { | |
3162 | tree arg1; | |
3163 | ||
3164 | switch (DECL_FUNCTION_CODE (fndecl)) | |
3165 | { | |
3166 | CASE_FLT_FN (BUILT_IN_ACOS): | |
3167 | CASE_FLT_FN (BUILT_IN_ACOSH): | |
3168 | CASE_FLT_FN (BUILT_IN_CABS): | |
3169 | CASE_FLT_FN (BUILT_IN_COSH): | |
3170 | CASE_FLT_FN (BUILT_IN_ERFC): | |
3171 | CASE_FLT_FN (BUILT_IN_EXP): | |
3172 | CASE_FLT_FN (BUILT_IN_EXP10): | |
3173 | CASE_FLT_FN (BUILT_IN_EXP2): | |
3174 | CASE_FLT_FN (BUILT_IN_FABS): | |
3175 | CASE_FLT_FN (BUILT_IN_FDIM): | |
3176 | CASE_FLT_FN (BUILT_IN_HYPOT): | |
3177 | CASE_FLT_FN (BUILT_IN_POW10): | |
3178 | return true; | |
3179 | ||
3180 | CASE_FLT_FN (BUILT_IN_SQRT): | |
3181 | /* sqrt(-0.0) is -0.0, and sqrt is not defined over other | |
3182 | nonnegative inputs. */ | |
3183 | if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (val)))) | |
3184 | return true; | |
3185 | ||
3186 | break; | |
3187 | ||
3188 | CASE_FLT_FN (BUILT_IN_POWI): | |
3189 | /* True if the second argument is an even integer. */ | |
3190 | arg1 = gimple_call_arg (def_stmt, 1); | |
3191 | ||
3192 | if (TREE_CODE (arg1) == INTEGER_CST | |
3193 | && (TREE_INT_CST_LOW (arg1) & 1) == 0) | |
3194 | return true; | |
3195 | ||
3196 | break; | |
3197 | ||
3198 | CASE_FLT_FN (BUILT_IN_POW): | |
3199 | /* True if the second argument is an even integer-valued | |
3200 | real. */ | |
3201 | arg1 = gimple_call_arg (def_stmt, 1); | |
3202 | ||
3203 | if (TREE_CODE (arg1) == REAL_CST) | |
3204 | { | |
3205 | REAL_VALUE_TYPE c; | |
3206 | HOST_WIDE_INT n; | |
3207 | ||
3208 | c = TREE_REAL_CST (arg1); | |
3209 | n = real_to_integer (&c); | |
3210 | ||
3211 | if ((n & 1) == 0) | |
3212 | { | |
3213 | REAL_VALUE_TYPE cint; | |
3214 | real_from_integer (&cint, VOIDmode, n, n < 0 ? -1 : 0, 0); | |
3215 | if (real_identical (&c, &cint)) | |
3216 | return true; | |
3217 | } | |
3218 | } | |
3219 | ||
3220 | break; | |
3221 | ||
3222 | default: | |
3223 | return false; | |
3224 | } | |
3225 | } | |
3226 | } | |
3227 | ||
3228 | return false; | |
3229 | } |