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cbdd87d4 | 1 | /* Statement simplification on GIMPLE. |
949e47e5 | 2 | Copyright (C) 2010, 2011, 2012 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)) | |
ead84f73 | 73 | || vnode->alias |
1389294c | 74 | || !vnode->finalized); |
b3b9f3d0 | 75 | return false; |
1389294c | 76 | } |
b3b9f3d0 JH |
77 | /* When function is public, we always can introduce new reference. |
78 | Exception are the COMDAT functions where introducing a direct | |
79 | reference imply need to include function body in the curren tunit. */ | |
80 | if (TREE_PUBLIC (decl) && !DECL_COMDAT (decl)) | |
81 | return true; | |
82 | /* We are not at ltrans stage; so don't worry about WHOPR. | |
83 | Also when still gimplifying all referred comdat functions will be | |
2e9bb6ba JH |
84 | produced. |
85 | ??? as observed in PR20991 for already optimized out comdat virtual functions | |
86 | we may not neccesarily give up because the copy will be output elsewhere when | |
87 | corresponding vtable is output. */ | |
b3b9f3d0 JH |
88 | if (!flag_ltrans && (!DECL_COMDAT (decl) || !cgraph_function_flags_ready)) |
89 | return true; | |
90 | /* If we already output the function body, we are safe. */ | |
91 | if (TREE_ASM_WRITTEN (decl)) | |
92 | return true; | |
1389294c JH |
93 | if (TREE_CODE (decl) == FUNCTION_DECL) |
94 | { | |
95 | node = cgraph_get_node (decl); | |
b3b9f3d0 JH |
96 | /* Check that we still have function body and that we didn't took |
97 | the decision to eliminate offline copy of the function yet. | |
98 | The second is important when devirtualization happens during final | |
99 | compilation stage when making a new reference no longer makes callee | |
100 | to be compiled. */ | |
101 | if (!node || !node->analyzed || node->global.inlined_to) | |
102 | return false; | |
1389294c JH |
103 | } |
104 | else if (TREE_CODE (decl) == VAR_DECL) | |
105 | { | |
106 | vnode = varpool_get_node (decl); | |
107 | if (!vnode || !vnode->finalized) | |
b3b9f3d0 | 108 | return false; |
1389294c | 109 | } |
b3b9f3d0 | 110 | return true; |
1389294c JH |
111 | } |
112 | ||
0038d4e0 | 113 | /* CVAL is value taken from DECL_INITIAL of variable. Try to transform it into |
17f39a39 JH |
114 | acceptable form for is_gimple_min_invariant. */ |
115 | ||
116 | tree | |
117 | canonicalize_constructor_val (tree cval) | |
118 | { | |
119 | STRIP_NOPS (cval); | |
315f5f1b RG |
120 | if (TREE_CODE (cval) == POINTER_PLUS_EXPR |
121 | && TREE_CODE (TREE_OPERAND (cval, 1)) == INTEGER_CST) | |
17f39a39 | 122 | { |
315f5f1b RG |
123 | tree ptr = TREE_OPERAND (cval, 0); |
124 | if (is_gimple_min_invariant (ptr)) | |
125 | cval = build1_loc (EXPR_LOCATION (cval), | |
126 | ADDR_EXPR, TREE_TYPE (ptr), | |
127 | fold_build2 (MEM_REF, TREE_TYPE (TREE_TYPE (ptr)), | |
128 | ptr, | |
129 | fold_convert (ptr_type_node, | |
130 | TREE_OPERAND (cval, 1)))); | |
17f39a39 JH |
131 | } |
132 | if (TREE_CODE (cval) == ADDR_EXPR) | |
133 | { | |
134 | tree base = get_base_address (TREE_OPERAND (cval, 0)); | |
7501ca28 RG |
135 | if (!base) |
136 | return NULL_TREE; | |
b3b9f3d0 | 137 | |
7501ca28 RG |
138 | if ((TREE_CODE (base) == VAR_DECL |
139 | || TREE_CODE (base) == FUNCTION_DECL) | |
b3b9f3d0 | 140 | && !can_refer_decl_in_current_unit_p (base)) |
1389294c | 141 | return NULL_TREE; |
7501ca28 | 142 | if (TREE_CODE (base) == VAR_DECL) |
c5bdb340 RG |
143 | { |
144 | TREE_ADDRESSABLE (base) = 1; | |
145 | if (cfun && gimple_referenced_vars (cfun)) | |
146 | add_referenced_var (base); | |
147 | } | |
7501ca28 RG |
148 | else if (TREE_CODE (base) == FUNCTION_DECL) |
149 | { | |
150 | /* Make sure we create a cgraph node for functions we'll reference. | |
151 | They can be non-existent if the reference comes from an entry | |
152 | of an external vtable for example. */ | |
153 | cgraph_get_create_node (base); | |
154 | } | |
0038d4e0 | 155 | /* Fixup types in global initializers. */ |
73aef89e RG |
156 | if (TREE_TYPE (TREE_TYPE (cval)) != TREE_TYPE (TREE_OPERAND (cval, 0))) |
157 | cval = build_fold_addr_expr (TREE_OPERAND (cval, 0)); | |
17f39a39 JH |
158 | } |
159 | return cval; | |
160 | } | |
cbdd87d4 RG |
161 | |
162 | /* If SYM is a constant variable with known value, return the value. | |
163 | NULL_TREE is returned otherwise. */ | |
164 | ||
165 | tree | |
166 | get_symbol_constant_value (tree sym) | |
167 | { | |
64e0f5ff | 168 | if (const_value_known_p (sym)) |
cbdd87d4 RG |
169 | { |
170 | tree val = DECL_INITIAL (sym); | |
171 | if (val) | |
172 | { | |
17f39a39 | 173 | val = canonicalize_constructor_val (val); |
1389294c | 174 | if (val && is_gimple_min_invariant (val)) |
17f39a39 | 175 | return val; |
1389294c JH |
176 | else |
177 | return NULL_TREE; | |
cbdd87d4 RG |
178 | } |
179 | /* Variables declared 'const' without an initializer | |
180 | have zero as the initializer if they may not be | |
181 | overridden at link or run time. */ | |
182 | if (!val | |
cbdd87d4 RG |
183 | && (INTEGRAL_TYPE_P (TREE_TYPE (sym)) |
184 | || SCALAR_FLOAT_TYPE_P (TREE_TYPE (sym)))) | |
e8160c9a | 185 | return build_zero_cst (TREE_TYPE (sym)); |
cbdd87d4 RG |
186 | } |
187 | ||
188 | return NULL_TREE; | |
189 | } | |
190 | ||
191 | ||
cbdd87d4 RG |
192 | |
193 | /* Subroutine of fold_stmt. We perform several simplifications of the | |
194 | memory reference tree EXPR and make sure to re-gimplify them properly | |
195 | after propagation of constant addresses. IS_LHS is true if the | |
196 | reference is supposed to be an lvalue. */ | |
197 | ||
198 | static tree | |
199 | maybe_fold_reference (tree expr, bool is_lhs) | |
200 | { | |
201 | tree *t = &expr; | |
17f39a39 | 202 | tree result; |
cbdd87d4 | 203 | |
f0eddb90 RG |
204 | if ((TREE_CODE (expr) == VIEW_CONVERT_EXPR |
205 | || TREE_CODE (expr) == REALPART_EXPR | |
206 | || TREE_CODE (expr) == IMAGPART_EXPR) | |
207 | && CONSTANT_CLASS_P (TREE_OPERAND (expr, 0))) | |
208 | return fold_unary_loc (EXPR_LOCATION (expr), | |
209 | TREE_CODE (expr), | |
210 | TREE_TYPE (expr), | |
211 | TREE_OPERAND (expr, 0)); | |
212 | else if (TREE_CODE (expr) == BIT_FIELD_REF | |
213 | && CONSTANT_CLASS_P (TREE_OPERAND (expr, 0))) | |
214 | return fold_ternary_loc (EXPR_LOCATION (expr), | |
215 | TREE_CODE (expr), | |
216 | TREE_TYPE (expr), | |
217 | TREE_OPERAND (expr, 0), | |
218 | TREE_OPERAND (expr, 1), | |
219 | TREE_OPERAND (expr, 2)); | |
220 | ||
221 | while (handled_component_p (*t)) | |
222 | t = &TREE_OPERAND (*t, 0); | |
cbdd87d4 | 223 | |
f0eddb90 RG |
224 | /* Canonicalize MEM_REFs invariant address operand. Do this first |
225 | to avoid feeding non-canonical MEM_REFs elsewhere. */ | |
226 | if (TREE_CODE (*t) == MEM_REF | |
227 | && !is_gimple_mem_ref_addr (TREE_OPERAND (*t, 0))) | |
cbdd87d4 | 228 | { |
f0eddb90 RG |
229 | bool volatile_p = TREE_THIS_VOLATILE (*t); |
230 | tree tem = fold_binary (MEM_REF, TREE_TYPE (*t), | |
231 | TREE_OPERAND (*t, 0), | |
232 | TREE_OPERAND (*t, 1)); | |
233 | if (tem) | |
234 | { | |
235 | TREE_THIS_VOLATILE (tem) = volatile_p; | |
236 | *t = tem; | |
237 | tem = maybe_fold_reference (expr, is_lhs); | |
238 | if (tem) | |
239 | return tem; | |
240 | return expr; | |
241 | } | |
cbdd87d4 RG |
242 | } |
243 | ||
f0eddb90 RG |
244 | if (!is_lhs |
245 | && (result = fold_const_aggregate_ref (expr)) | |
246 | && is_gimple_min_invariant (result)) | |
247 | return result; | |
cbdd87d4 | 248 | |
70f34814 RG |
249 | /* Fold back MEM_REFs to reference trees. */ |
250 | if (TREE_CODE (*t) == MEM_REF | |
251 | && TREE_CODE (TREE_OPERAND (*t, 0)) == ADDR_EXPR | |
252 | && integer_zerop (TREE_OPERAND (*t, 1)) | |
253 | && (TREE_THIS_VOLATILE (*t) | |
254 | == TREE_THIS_VOLATILE (TREE_OPERAND (TREE_OPERAND (*t, 0), 0))) | |
255 | && !TYPE_REF_CAN_ALIAS_ALL (TREE_TYPE (TREE_OPERAND (*t, 1))) | |
256 | && (TYPE_MAIN_VARIANT (TREE_TYPE (*t)) | |
257 | == TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (TREE_OPERAND (*t, 1))))) | |
258 | /* We have to look out here to not drop a required conversion | |
259 | from the rhs to the lhs if is_lhs, but we don't have the | |
260 | rhs here to verify that. Thus require strict type | |
261 | compatibility. */ | |
262 | && types_compatible_p (TREE_TYPE (*t), | |
263 | TREE_TYPE (TREE_OPERAND | |
f0eddb90 | 264 | (TREE_OPERAND (*t, 0), 0)))) |
cbdd87d4 | 265 | { |
70f34814 RG |
266 | tree tem; |
267 | *t = TREE_OPERAND (TREE_OPERAND (*t, 0), 0); | |
268 | tem = maybe_fold_reference (expr, is_lhs); | |
269 | if (tem) | |
270 | return tem; | |
271 | return expr; | |
272 | } | |
4d948885 RG |
273 | else if (TREE_CODE (*t) == TARGET_MEM_REF) |
274 | { | |
275 | tree tem = maybe_fold_tmr (*t); | |
276 | if (tem) | |
277 | { | |
278 | *t = tem; | |
279 | tem = maybe_fold_reference (expr, is_lhs); | |
280 | if (tem) | |
281 | return tem; | |
282 | return expr; | |
283 | } | |
284 | } | |
cbdd87d4 RG |
285 | |
286 | return NULL_TREE; | |
287 | } | |
288 | ||
289 | ||
290 | /* Attempt to fold an assignment statement pointed-to by SI. Returns a | |
291 | replacement rhs for the statement or NULL_TREE if no simplification | |
292 | could be made. It is assumed that the operands have been previously | |
293 | folded. */ | |
294 | ||
295 | static tree | |
296 | fold_gimple_assign (gimple_stmt_iterator *si) | |
297 | { | |
298 | gimple stmt = gsi_stmt (*si); | |
299 | enum tree_code subcode = gimple_assign_rhs_code (stmt); | |
300 | location_t loc = gimple_location (stmt); | |
301 | ||
302 | tree result = NULL_TREE; | |
303 | ||
304 | switch (get_gimple_rhs_class (subcode)) | |
305 | { | |
306 | case GIMPLE_SINGLE_RHS: | |
307 | { | |
308 | tree rhs = gimple_assign_rhs1 (stmt); | |
309 | ||
4e71066d | 310 | if (REFERENCE_CLASS_P (rhs)) |
cbdd87d4 RG |
311 | return maybe_fold_reference (rhs, false); |
312 | ||
313 | else if (TREE_CODE (rhs) == ADDR_EXPR) | |
314 | { | |
70f34814 RG |
315 | tree ref = TREE_OPERAND (rhs, 0); |
316 | tree tem = maybe_fold_reference (ref, true); | |
317 | if (tem | |
318 | && TREE_CODE (tem) == MEM_REF | |
319 | && integer_zerop (TREE_OPERAND (tem, 1))) | |
320 | result = fold_convert (TREE_TYPE (rhs), TREE_OPERAND (tem, 0)); | |
321 | else if (tem) | |
cbdd87d4 RG |
322 | result = fold_convert (TREE_TYPE (rhs), |
323 | build_fold_addr_expr_loc (loc, tem)); | |
70f34814 RG |
324 | else if (TREE_CODE (ref) == MEM_REF |
325 | && integer_zerop (TREE_OPERAND (ref, 1))) | |
326 | result = fold_convert (TREE_TYPE (rhs), TREE_OPERAND (ref, 0)); | |
cbdd87d4 RG |
327 | } |
328 | ||
329 | else if (TREE_CODE (rhs) == CONSTRUCTOR | |
330 | && TREE_CODE (TREE_TYPE (rhs)) == VECTOR_TYPE | |
331 | && (CONSTRUCTOR_NELTS (rhs) | |
332 | == TYPE_VECTOR_SUBPARTS (TREE_TYPE (rhs)))) | |
333 | { | |
334 | /* Fold a constant vector CONSTRUCTOR to VECTOR_CST. */ | |
335 | unsigned i; | |
336 | tree val; | |
337 | ||
338 | FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (rhs), i, val) | |
339 | if (TREE_CODE (val) != INTEGER_CST | |
340 | && TREE_CODE (val) != REAL_CST | |
341 | && TREE_CODE (val) != FIXED_CST) | |
342 | return NULL_TREE; | |
343 | ||
344 | return build_vector_from_ctor (TREE_TYPE (rhs), | |
345 | CONSTRUCTOR_ELTS (rhs)); | |
346 | } | |
347 | ||
348 | else if (DECL_P (rhs)) | |
349 | return unshare_expr (get_symbol_constant_value (rhs)); | |
350 | ||
351 | /* If we couldn't fold the RHS, hand over to the generic | |
352 | fold routines. */ | |
353 | if (result == NULL_TREE) | |
354 | result = fold (rhs); | |
355 | ||
356 | /* Strip away useless type conversions. Both the NON_LVALUE_EXPR | |
357 | that may have been added by fold, and "useless" type | |
358 | conversions that might now be apparent due to propagation. */ | |
359 | STRIP_USELESS_TYPE_CONVERSION (result); | |
360 | ||
361 | if (result != rhs && valid_gimple_rhs_p (result)) | |
362 | return result; | |
363 | ||
364 | return NULL_TREE; | |
365 | } | |
366 | break; | |
367 | ||
368 | case GIMPLE_UNARY_RHS: | |
369 | { | |
370 | tree rhs = gimple_assign_rhs1 (stmt); | |
371 | ||
372 | result = fold_unary_loc (loc, subcode, gimple_expr_type (stmt), rhs); | |
373 | if (result) | |
374 | { | |
375 | /* If the operation was a conversion do _not_ mark a | |
376 | resulting constant with TREE_OVERFLOW if the original | |
377 | constant was not. These conversions have implementation | |
378 | defined behavior and retaining the TREE_OVERFLOW flag | |
379 | here would confuse later passes such as VRP. */ | |
380 | if (CONVERT_EXPR_CODE_P (subcode) | |
381 | && TREE_CODE (result) == INTEGER_CST | |
382 | && TREE_CODE (rhs) == INTEGER_CST) | |
383 | TREE_OVERFLOW (result) = TREE_OVERFLOW (rhs); | |
384 | ||
385 | STRIP_USELESS_TYPE_CONVERSION (result); | |
386 | if (valid_gimple_rhs_p (result)) | |
387 | return result; | |
388 | } | |
cbdd87d4 RG |
389 | } |
390 | break; | |
391 | ||
392 | case GIMPLE_BINARY_RHS: | |
9b80d091 KT |
393 | /* Try to canonicalize for boolean-typed X the comparisons |
394 | X == 0, X == 1, X != 0, and X != 1. */ | |
315f5f1b RG |
395 | if (gimple_assign_rhs_code (stmt) == EQ_EXPR |
396 | || gimple_assign_rhs_code (stmt) == NE_EXPR) | |
9b80d091 KT |
397 | { |
398 | tree lhs = gimple_assign_lhs (stmt); | |
399 | tree op1 = gimple_assign_rhs1 (stmt); | |
400 | tree op2 = gimple_assign_rhs2 (stmt); | |
401 | tree type = TREE_TYPE (op1); | |
402 | ||
403 | /* Check whether the comparison operands are of the same boolean | |
404 | type as the result type is. | |
405 | Check that second operand is an integer-constant with value | |
406 | one or zero. */ | |
407 | if (TREE_CODE (op2) == INTEGER_CST | |
408 | && (integer_zerop (op2) || integer_onep (op2)) | |
409 | && useless_type_conversion_p (TREE_TYPE (lhs), type)) | |
410 | { | |
411 | enum tree_code cmp_code = gimple_assign_rhs_code (stmt); | |
412 | bool is_logical_not = false; | |
413 | ||
414 | /* X == 0 and X != 1 is a logical-not.of X | |
415 | X == 1 and X != 0 is X */ | |
416 | if ((cmp_code == EQ_EXPR && integer_zerop (op2)) | |
417 | || (cmp_code == NE_EXPR && integer_onep (op2))) | |
418 | is_logical_not = true; | |
419 | ||
420 | if (is_logical_not == false) | |
421 | result = op1; | |
422 | /* Only for one-bit precision typed X the transformation | |
423 | !X -> ~X is valied. */ | |
424 | else if (TYPE_PRECISION (type) == 1) | |
425 | result = build1_loc (gimple_location (stmt), BIT_NOT_EXPR, | |
426 | type, op1); | |
427 | /* Otherwise we use !X -> X ^ 1. */ | |
428 | else | |
429 | result = build2_loc (gimple_location (stmt), BIT_XOR_EXPR, | |
430 | type, op1, build_int_cst (type, 1)); | |
431 | ||
432 | } | |
433 | } | |
cbdd87d4 RG |
434 | |
435 | if (!result) | |
436 | result = fold_binary_loc (loc, subcode, | |
5fbcc0ed RG |
437 | TREE_TYPE (gimple_assign_lhs (stmt)), |
438 | gimple_assign_rhs1 (stmt), | |
439 | gimple_assign_rhs2 (stmt)); | |
cbdd87d4 RG |
440 | |
441 | if (result) | |
442 | { | |
443 | STRIP_USELESS_TYPE_CONVERSION (result); | |
444 | if (valid_gimple_rhs_p (result)) | |
445 | return result; | |
cbdd87d4 RG |
446 | } |
447 | break; | |
448 | ||
0354c0c7 | 449 | case GIMPLE_TERNARY_RHS: |
4e71066d RG |
450 | /* Try to fold a conditional expression. */ |
451 | if (gimple_assign_rhs_code (stmt) == COND_EXPR) | |
452 | { | |
453 | tree op0 = gimple_assign_rhs1 (stmt); | |
454 | tree tem; | |
455 | bool set = false; | |
456 | location_t cond_loc = gimple_location (stmt); | |
457 | ||
458 | if (COMPARISON_CLASS_P (op0)) | |
459 | { | |
460 | fold_defer_overflow_warnings (); | |
461 | tem = fold_binary_loc (cond_loc, | |
462 | TREE_CODE (op0), TREE_TYPE (op0), | |
463 | TREE_OPERAND (op0, 0), | |
464 | TREE_OPERAND (op0, 1)); | |
465 | /* This is actually a conditional expression, not a GIMPLE | |
466 | conditional statement, however, the valid_gimple_rhs_p | |
467 | test still applies. */ | |
468 | set = (tem && is_gimple_condexpr (tem) | |
469 | && valid_gimple_rhs_p (tem)); | |
470 | fold_undefer_overflow_warnings (set, stmt, 0); | |
471 | } | |
472 | else if (is_gimple_min_invariant (op0)) | |
473 | { | |
474 | tem = op0; | |
475 | set = true; | |
476 | } | |
477 | else | |
478 | return NULL_TREE; | |
479 | ||
480 | if (set) | |
481 | result = fold_build3_loc (cond_loc, COND_EXPR, | |
482 | TREE_TYPE (gimple_assign_lhs (stmt)), tem, | |
483 | gimple_assign_rhs2 (stmt), | |
484 | gimple_assign_rhs3 (stmt)); | |
485 | } | |
486 | ||
487 | if (!result) | |
488 | result = fold_ternary_loc (loc, subcode, | |
489 | TREE_TYPE (gimple_assign_lhs (stmt)), | |
490 | gimple_assign_rhs1 (stmt), | |
491 | gimple_assign_rhs2 (stmt), | |
492 | gimple_assign_rhs3 (stmt)); | |
0354c0c7 BS |
493 | |
494 | if (result) | |
495 | { | |
496 | STRIP_USELESS_TYPE_CONVERSION (result); | |
497 | if (valid_gimple_rhs_p (result)) | |
498 | return result; | |
0354c0c7 BS |
499 | } |
500 | break; | |
501 | ||
cbdd87d4 RG |
502 | case GIMPLE_INVALID_RHS: |
503 | gcc_unreachable (); | |
504 | } | |
505 | ||
506 | return NULL_TREE; | |
507 | } | |
508 | ||
509 | /* Attempt to fold a conditional statement. Return true if any changes were | |
510 | made. We only attempt to fold the condition expression, and do not perform | |
511 | any transformation that would require alteration of the cfg. It is | |
512 | assumed that the operands have been previously folded. */ | |
513 | ||
514 | static bool | |
515 | fold_gimple_cond (gimple stmt) | |
516 | { | |
517 | tree result = fold_binary_loc (gimple_location (stmt), | |
518 | gimple_cond_code (stmt), | |
519 | boolean_type_node, | |
520 | gimple_cond_lhs (stmt), | |
521 | gimple_cond_rhs (stmt)); | |
522 | ||
523 | if (result) | |
524 | { | |
525 | STRIP_USELESS_TYPE_CONVERSION (result); | |
526 | if (is_gimple_condexpr (result) && valid_gimple_rhs_p (result)) | |
527 | { | |
528 | gimple_cond_set_condition_from_tree (stmt, result); | |
529 | return true; | |
530 | } | |
531 | } | |
532 | ||
533 | return false; | |
534 | } | |
535 | ||
536 | /* Convert EXPR into a GIMPLE value suitable for substitution on the | |
537 | RHS of an assignment. Insert the necessary statements before | |
538 | iterator *SI_P. The statement at *SI_P, which must be a GIMPLE_CALL | |
539 | is replaced. If the call is expected to produces a result, then it | |
540 | is replaced by an assignment of the new RHS to the result variable. | |
541 | If the result is to be ignored, then the call is replaced by a | |
fe2ef088 MM |
542 | GIMPLE_NOP. A proper VDEF chain is retained by making the first |
543 | VUSE and the last VDEF of the whole sequence be the same as the replaced | |
544 | statement and using new SSA names for stores in between. */ | |
cbdd87d4 RG |
545 | |
546 | void | |
547 | gimplify_and_update_call_from_tree (gimple_stmt_iterator *si_p, tree expr) | |
548 | { | |
549 | tree lhs; | |
cbdd87d4 RG |
550 | gimple stmt, new_stmt; |
551 | gimple_stmt_iterator i; | |
552 | gimple_seq stmts = gimple_seq_alloc(); | |
553 | struct gimplify_ctx gctx; | |
e256dfce RG |
554 | gimple last; |
555 | gimple laststore; | |
fe2ef088 | 556 | tree reaching_vuse; |
cbdd87d4 RG |
557 | |
558 | stmt = gsi_stmt (*si_p); | |
559 | ||
560 | gcc_assert (is_gimple_call (stmt)); | |
561 | ||
cbdd87d4 | 562 | push_gimplify_context (&gctx); |
21860814 | 563 | gctx.into_ssa = gimple_in_ssa_p (cfun); |
cbdd87d4 | 564 | |
e256dfce | 565 | lhs = gimple_call_lhs (stmt); |
cbdd87d4 | 566 | if (lhs == NULL_TREE) |
6e572326 RG |
567 | { |
568 | gimplify_and_add (expr, &stmts); | |
569 | /* We can end up with folding a memcpy of an empty class assignment | |
570 | which gets optimized away by C++ gimplification. */ | |
571 | if (gimple_seq_empty_p (stmts)) | |
572 | { | |
9fdc58de | 573 | pop_gimplify_context (NULL); |
6e572326 RG |
574 | if (gimple_in_ssa_p (cfun)) |
575 | { | |
576 | unlink_stmt_vdef (stmt); | |
577 | release_defs (stmt); | |
578 | } | |
579 | gsi_remove (si_p, true); | |
580 | return; | |
581 | } | |
582 | } | |
cbdd87d4 | 583 | else |
e256dfce RG |
584 | { |
585 | tree tmp = get_initialized_tmp_var (expr, &stmts, NULL); | |
586 | new_stmt = gimple_build_assign (lhs, tmp); | |
587 | i = gsi_last (stmts); | |
588 | gsi_insert_after_without_update (&i, new_stmt, | |
589 | GSI_CONTINUE_LINKING); | |
590 | } | |
cbdd87d4 RG |
591 | |
592 | pop_gimplify_context (NULL); | |
593 | ||
594 | if (gimple_has_location (stmt)) | |
595 | annotate_all_with_location (stmts, gimple_location (stmt)); | |
596 | ||
e256dfce RG |
597 | /* First iterate over the replacement statements backward, assigning |
598 | virtual operands to their defining statements. */ | |
599 | laststore = NULL; | |
600 | for (i = gsi_last (stmts); !gsi_end_p (i); gsi_prev (&i)) | |
601 | { | |
602 | new_stmt = gsi_stmt (i); | |
949e47e5 JJ |
603 | if ((gimple_assign_single_p (new_stmt) |
604 | && !is_gimple_reg (gimple_assign_lhs (new_stmt))) | |
605 | || (is_gimple_call (new_stmt) | |
606 | && (gimple_call_flags (new_stmt) | |
607 | & (ECF_NOVOPS | ECF_PURE | ECF_CONST | ECF_NORETURN)) == 0)) | |
e256dfce RG |
608 | { |
609 | tree vdef; | |
610 | if (!laststore) | |
611 | vdef = gimple_vdef (stmt); | |
612 | else | |
613 | vdef = make_ssa_name (gimple_vop (cfun), new_stmt); | |
614 | gimple_set_vdef (new_stmt, vdef); | |
52f26be4 | 615 | if (vdef && TREE_CODE (vdef) == SSA_NAME) |
e256dfce RG |
616 | SSA_NAME_DEF_STMT (vdef) = new_stmt; |
617 | laststore = new_stmt; | |
618 | } | |
619 | } | |
620 | ||
621 | /* Second iterate over the statements forward, assigning virtual | |
622 | operands to their uses. */ | |
623 | last = NULL; | |
624 | reaching_vuse = gimple_vuse (stmt); | |
cbdd87d4 RG |
625 | for (i = gsi_start (stmts); !gsi_end_p (i); gsi_next (&i)) |
626 | { | |
e256dfce RG |
627 | /* Do not insert the last stmt in this loop but remember it |
628 | for replacing the original statement. */ | |
cbdd87d4 RG |
629 | if (last) |
630 | { | |
631 | gsi_insert_before (si_p, last, GSI_NEW_STMT); | |
632 | gsi_next (si_p); | |
633 | } | |
634 | new_stmt = gsi_stmt (i); | |
e256dfce | 635 | /* The replacement can expose previously unreferenced variables. */ |
edc74207 | 636 | if (gimple_in_ssa_p (cfun)) |
a24ac460 RG |
637 | find_new_referenced_vars (new_stmt); |
638 | /* If the new statement possibly has a VUSE, update it with exact SSA | |
639 | name we know will reach this one. */ | |
640 | if (gimple_has_mem_ops (new_stmt)) | |
e256dfce RG |
641 | gimple_set_vuse (new_stmt, reaching_vuse); |
642 | gimple_set_modified (new_stmt, true); | |
643 | if (gimple_vdef (new_stmt)) | |
644 | reaching_vuse = gimple_vdef (new_stmt); | |
cbdd87d4 RG |
645 | last = new_stmt; |
646 | } | |
647 | ||
e256dfce RG |
648 | /* If the new sequence does not do a store release the virtual |
649 | definition of the original statement. */ | |
650 | if (reaching_vuse | |
651 | && reaching_vuse == gimple_vuse (stmt)) | |
cbdd87d4 | 652 | { |
e256dfce RG |
653 | tree vdef = gimple_vdef (stmt); |
654 | if (vdef | |
655 | && TREE_CODE (vdef) == SSA_NAME) | |
fe2ef088 MM |
656 | { |
657 | unlink_stmt_vdef (stmt); | |
e256dfce | 658 | release_ssa_name (vdef); |
8a1561bc | 659 | } |
cbdd87d4 RG |
660 | } |
661 | ||
e256dfce RG |
662 | /* Finally replace rhe original statement with the last. */ |
663 | gsi_replace (si_p, last, false); | |
cbdd87d4 RG |
664 | } |
665 | ||
666 | /* Return the string length, maximum string length or maximum value of | |
667 | ARG in LENGTH. | |
668 | If ARG is an SSA name variable, follow its use-def chains. If LENGTH | |
669 | is not NULL and, for TYPE == 0, its value is not equal to the length | |
670 | we determine or if we are unable to determine the length or value, | |
671 | return false. VISITED is a bitmap of visited variables. | |
672 | TYPE is 0 if string length should be returned, 1 for maximum string | |
673 | length and 2 for maximum value ARG can have. */ | |
674 | ||
675 | static bool | |
676 | get_maxval_strlen (tree arg, tree *length, bitmap visited, int type) | |
677 | { | |
678 | tree var, val; | |
679 | gimple def_stmt; | |
680 | ||
681 | if (TREE_CODE (arg) != SSA_NAME) | |
682 | { | |
683 | if (TREE_CODE (arg) == COND_EXPR) | |
684 | return get_maxval_strlen (COND_EXPR_THEN (arg), length, visited, type) | |
685 | && get_maxval_strlen (COND_EXPR_ELSE (arg), length, visited, type); | |
686 | /* We can end up with &(*iftmp_1)[0] here as well, so handle it. */ | |
687 | else if (TREE_CODE (arg) == ADDR_EXPR | |
688 | && TREE_CODE (TREE_OPERAND (arg, 0)) == ARRAY_REF | |
689 | && integer_zerop (TREE_OPERAND (TREE_OPERAND (arg, 0), 1))) | |
690 | { | |
691 | tree aop0 = TREE_OPERAND (TREE_OPERAND (arg, 0), 0); | |
692 | if (TREE_CODE (aop0) == INDIRECT_REF | |
693 | && TREE_CODE (TREE_OPERAND (aop0, 0)) == SSA_NAME) | |
694 | return get_maxval_strlen (TREE_OPERAND (aop0, 0), | |
695 | length, visited, type); | |
696 | } | |
697 | ||
698 | if (type == 2) | |
699 | { | |
700 | val = arg; | |
701 | if (TREE_CODE (val) != INTEGER_CST | |
702 | || tree_int_cst_sgn (val) < 0) | |
703 | return false; | |
704 | } | |
705 | else | |
706 | val = c_strlen (arg, 1); | |
707 | if (!val) | |
708 | return false; | |
709 | ||
710 | if (*length) | |
711 | { | |
712 | if (type > 0) | |
713 | { | |
714 | if (TREE_CODE (*length) != INTEGER_CST | |
715 | || TREE_CODE (val) != INTEGER_CST) | |
716 | return false; | |
717 | ||
718 | if (tree_int_cst_lt (*length, val)) | |
719 | *length = val; | |
720 | return true; | |
721 | } | |
722 | else if (simple_cst_equal (val, *length) != 1) | |
723 | return false; | |
724 | } | |
725 | ||
726 | *length = val; | |
727 | return true; | |
728 | } | |
729 | ||
730 | /* If we were already here, break the infinite cycle. */ | |
fcaa4ca4 | 731 | if (!bitmap_set_bit (visited, SSA_NAME_VERSION (arg))) |
cbdd87d4 | 732 | return true; |
cbdd87d4 RG |
733 | |
734 | var = arg; | |
735 | def_stmt = SSA_NAME_DEF_STMT (var); | |
736 | ||
737 | switch (gimple_code (def_stmt)) | |
738 | { | |
739 | case GIMPLE_ASSIGN: | |
740 | /* The RHS of the statement defining VAR must either have a | |
741 | constant length or come from another SSA_NAME with a constant | |
742 | length. */ | |
743 | if (gimple_assign_single_p (def_stmt) | |
744 | || gimple_assign_unary_nop_p (def_stmt)) | |
745 | { | |
746 | tree rhs = gimple_assign_rhs1 (def_stmt); | |
747 | return get_maxval_strlen (rhs, length, visited, type); | |
748 | } | |
749 | return false; | |
750 | ||
751 | case GIMPLE_PHI: | |
752 | { | |
753 | /* All the arguments of the PHI node must have the same constant | |
754 | length. */ | |
755 | unsigned i; | |
756 | ||
757 | for (i = 0; i < gimple_phi_num_args (def_stmt); i++) | |
758 | { | |
759 | tree arg = gimple_phi_arg (def_stmt, i)->def; | |
760 | ||
761 | /* If this PHI has itself as an argument, we cannot | |
762 | determine the string length of this argument. However, | |
763 | if we can find a constant string length for the other | |
764 | PHI args then we can still be sure that this is a | |
765 | constant string length. So be optimistic and just | |
766 | continue with the next argument. */ | |
767 | if (arg == gimple_phi_result (def_stmt)) | |
768 | continue; | |
769 | ||
770 | if (!get_maxval_strlen (arg, length, visited, type)) | |
771 | return false; | |
772 | } | |
773 | } | |
774 | return true; | |
775 | ||
776 | default: | |
777 | return false; | |
778 | } | |
779 | } | |
780 | ||
781 | ||
782 | /* Fold builtin call in statement STMT. Returns a simplified tree. | |
783 | We may return a non-constant expression, including another call | |
784 | to a different function and with different arguments, e.g., | |
785 | substituting memcpy for strcpy when the string length is known. | |
786 | Note that some builtins expand into inline code that may not | |
787 | be valid in GIMPLE. Callers must take care. */ | |
788 | ||
789 | tree | |
790 | gimple_fold_builtin (gimple stmt) | |
791 | { | |
792 | tree result, val[3]; | |
793 | tree callee, a; | |
794 | int arg_idx, type; | |
795 | bitmap visited; | |
796 | bool ignore; | |
797 | int nargs; | |
798 | location_t loc = gimple_location (stmt); | |
799 | ||
800 | gcc_assert (is_gimple_call (stmt)); | |
801 | ||
802 | ignore = (gimple_call_lhs (stmt) == NULL); | |
803 | ||
804 | /* First try the generic builtin folder. If that succeeds, return the | |
805 | result directly. */ | |
806 | result = fold_call_stmt (stmt, ignore); | |
807 | if (result) | |
808 | { | |
809 | if (ignore) | |
810 | STRIP_NOPS (result); | |
811 | return result; | |
812 | } | |
813 | ||
814 | /* Ignore MD builtins. */ | |
815 | callee = gimple_call_fndecl (stmt); | |
816 | if (DECL_BUILT_IN_CLASS (callee) == BUILT_IN_MD) | |
817 | return NULL_TREE; | |
818 | ||
e7f9dae0 JJ |
819 | /* Give up for always_inline inline builtins until they are |
820 | inlined. */ | |
821 | if (avoid_folding_inline_builtin (callee)) | |
822 | return NULL_TREE; | |
823 | ||
cbdd87d4 RG |
824 | /* If the builtin could not be folded, and it has no argument list, |
825 | we're done. */ | |
826 | nargs = gimple_call_num_args (stmt); | |
827 | if (nargs == 0) | |
828 | return NULL_TREE; | |
829 | ||
830 | /* Limit the work only for builtins we know how to simplify. */ | |
831 | switch (DECL_FUNCTION_CODE (callee)) | |
832 | { | |
833 | case BUILT_IN_STRLEN: | |
834 | case BUILT_IN_FPUTS: | |
835 | case BUILT_IN_FPUTS_UNLOCKED: | |
836 | arg_idx = 0; | |
837 | type = 0; | |
838 | break; | |
839 | case BUILT_IN_STRCPY: | |
840 | case BUILT_IN_STRNCPY: | |
841 | arg_idx = 1; | |
842 | type = 0; | |
843 | break; | |
844 | case BUILT_IN_MEMCPY_CHK: | |
845 | case BUILT_IN_MEMPCPY_CHK: | |
846 | case BUILT_IN_MEMMOVE_CHK: | |
847 | case BUILT_IN_MEMSET_CHK: | |
848 | case BUILT_IN_STRNCPY_CHK: | |
f3fc9b80 | 849 | case BUILT_IN_STPNCPY_CHK: |
cbdd87d4 RG |
850 | arg_idx = 2; |
851 | type = 2; | |
852 | break; | |
853 | case BUILT_IN_STRCPY_CHK: | |
854 | case BUILT_IN_STPCPY_CHK: | |
855 | arg_idx = 1; | |
856 | type = 1; | |
857 | break; | |
858 | case BUILT_IN_SNPRINTF_CHK: | |
859 | case BUILT_IN_VSNPRINTF_CHK: | |
860 | arg_idx = 1; | |
861 | type = 2; | |
862 | break; | |
863 | default: | |
864 | return NULL_TREE; | |
865 | } | |
866 | ||
867 | if (arg_idx >= nargs) | |
868 | return NULL_TREE; | |
869 | ||
870 | /* Try to use the dataflow information gathered by the CCP process. */ | |
871 | visited = BITMAP_ALLOC (NULL); | |
872 | bitmap_clear (visited); | |
873 | ||
874 | memset (val, 0, sizeof (val)); | |
875 | a = gimple_call_arg (stmt, arg_idx); | |
876 | if (!get_maxval_strlen (a, &val[arg_idx], visited, type)) | |
877 | val[arg_idx] = NULL_TREE; | |
878 | ||
879 | BITMAP_FREE (visited); | |
880 | ||
881 | result = NULL_TREE; | |
882 | switch (DECL_FUNCTION_CODE (callee)) | |
883 | { | |
884 | case BUILT_IN_STRLEN: | |
885 | if (val[0] && nargs == 1) | |
886 | { | |
887 | tree new_val = | |
888 | fold_convert (TREE_TYPE (gimple_call_lhs (stmt)), val[0]); | |
889 | ||
890 | /* If the result is not a valid gimple value, or not a cast | |
6e4da084 | 891 | of a valid gimple value, then we cannot use the result. */ |
cbdd87d4 | 892 | if (is_gimple_val (new_val) |
3dbe9454 | 893 | || (CONVERT_EXPR_P (new_val) |
cbdd87d4 RG |
894 | && is_gimple_val (TREE_OPERAND (new_val, 0)))) |
895 | return new_val; | |
896 | } | |
897 | break; | |
898 | ||
899 | case BUILT_IN_STRCPY: | |
900 | if (val[1] && is_gimple_val (val[1]) && nargs == 2) | |
901 | result = fold_builtin_strcpy (loc, callee, | |
902 | gimple_call_arg (stmt, 0), | |
903 | gimple_call_arg (stmt, 1), | |
904 | val[1]); | |
905 | break; | |
906 | ||
907 | case BUILT_IN_STRNCPY: | |
908 | if (val[1] && is_gimple_val (val[1]) && nargs == 3) | |
909 | result = fold_builtin_strncpy (loc, callee, | |
910 | gimple_call_arg (stmt, 0), | |
911 | gimple_call_arg (stmt, 1), | |
912 | gimple_call_arg (stmt, 2), | |
913 | val[1]); | |
914 | break; | |
915 | ||
916 | case BUILT_IN_FPUTS: | |
917 | if (nargs == 2) | |
918 | result = fold_builtin_fputs (loc, gimple_call_arg (stmt, 0), | |
919 | gimple_call_arg (stmt, 1), | |
920 | ignore, false, val[0]); | |
921 | break; | |
922 | ||
923 | case BUILT_IN_FPUTS_UNLOCKED: | |
924 | if (nargs == 2) | |
925 | result = fold_builtin_fputs (loc, gimple_call_arg (stmt, 0), | |
926 | gimple_call_arg (stmt, 1), | |
927 | ignore, true, val[0]); | |
928 | break; | |
929 | ||
930 | case BUILT_IN_MEMCPY_CHK: | |
931 | case BUILT_IN_MEMPCPY_CHK: | |
932 | case BUILT_IN_MEMMOVE_CHK: | |
933 | case BUILT_IN_MEMSET_CHK: | |
934 | if (val[2] && is_gimple_val (val[2]) && nargs == 4) | |
935 | result = fold_builtin_memory_chk (loc, callee, | |
936 | gimple_call_arg (stmt, 0), | |
937 | gimple_call_arg (stmt, 1), | |
938 | gimple_call_arg (stmt, 2), | |
939 | gimple_call_arg (stmt, 3), | |
940 | val[2], ignore, | |
941 | DECL_FUNCTION_CODE (callee)); | |
942 | break; | |
943 | ||
944 | case BUILT_IN_STRCPY_CHK: | |
945 | case BUILT_IN_STPCPY_CHK: | |
946 | if (val[1] && is_gimple_val (val[1]) && nargs == 3) | |
947 | result = fold_builtin_stxcpy_chk (loc, callee, | |
948 | gimple_call_arg (stmt, 0), | |
949 | gimple_call_arg (stmt, 1), | |
950 | gimple_call_arg (stmt, 2), | |
951 | val[1], ignore, | |
952 | DECL_FUNCTION_CODE (callee)); | |
953 | break; | |
954 | ||
955 | case BUILT_IN_STRNCPY_CHK: | |
f3fc9b80 | 956 | case BUILT_IN_STPNCPY_CHK: |
cbdd87d4 | 957 | if (val[2] && is_gimple_val (val[2]) && nargs == 4) |
f3fc9b80 | 958 | result = fold_builtin_stxncpy_chk (loc, gimple_call_arg (stmt, 0), |
cbdd87d4 RG |
959 | gimple_call_arg (stmt, 1), |
960 | gimple_call_arg (stmt, 2), | |
961 | gimple_call_arg (stmt, 3), | |
f3fc9b80 RG |
962 | val[2], ignore, |
963 | DECL_FUNCTION_CODE (callee)); | |
cbdd87d4 RG |
964 | break; |
965 | ||
966 | case BUILT_IN_SNPRINTF_CHK: | |
967 | case BUILT_IN_VSNPRINTF_CHK: | |
968 | if (val[1] && is_gimple_val (val[1])) | |
969 | result = gimple_fold_builtin_snprintf_chk (stmt, val[1], | |
970 | DECL_FUNCTION_CODE (callee)); | |
971 | break; | |
972 | ||
973 | default: | |
974 | gcc_unreachable (); | |
975 | } | |
976 | ||
977 | if (result && ignore) | |
978 | result = fold_ignored_result (result); | |
979 | return result; | |
980 | } | |
981 | ||
1ae6fe9b | 982 | |
49c471e3 MJ |
983 | /* Return a binfo to be used for devirtualization of calls based on an object |
984 | represented by a declaration (i.e. a global or automatically allocated one) | |
985 | or NULL if it cannot be found or is not safe. CST is expected to be an | |
986 | ADDR_EXPR of such object or the function will return NULL. Currently it is | |
987 | safe to use such binfo only if it has no base binfo (i.e. no ancestors). */ | |
988 | ||
989 | tree | |
990 | gimple_extract_devirt_binfo_from_cst (tree cst) | |
991 | { | |
992 | HOST_WIDE_INT offset, size, max_size; | |
993 | tree base, type, expected_type, binfo; | |
994 | bool last_artificial = false; | |
995 | ||
996 | if (!flag_devirtualize | |
997 | || TREE_CODE (cst) != ADDR_EXPR | |
998 | || TREE_CODE (TREE_TYPE (TREE_TYPE (cst))) != RECORD_TYPE) | |
999 | return NULL_TREE; | |
1000 | ||
1001 | cst = TREE_OPERAND (cst, 0); | |
1002 | expected_type = TREE_TYPE (cst); | |
1003 | base = get_ref_base_and_extent (cst, &offset, &size, &max_size); | |
1004 | type = TREE_TYPE (base); | |
1005 | if (!DECL_P (base) | |
1006 | || max_size == -1 | |
1007 | || max_size != size | |
1008 | || TREE_CODE (type) != RECORD_TYPE) | |
1009 | return NULL_TREE; | |
1010 | ||
1011 | /* Find the sub-object the constant actually refers to and mark whether it is | |
1012 | an artificial one (as opposed to a user-defined one). */ | |
1013 | while (true) | |
1014 | { | |
1015 | HOST_WIDE_INT pos, size; | |
1016 | tree fld; | |
1017 | ||
1018 | if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (expected_type)) | |
1019 | break; | |
1020 | if (offset < 0) | |
1021 | return NULL_TREE; | |
1022 | ||
1023 | for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld)) | |
1024 | { | |
1025 | if (TREE_CODE (fld) != FIELD_DECL) | |
1026 | continue; | |
1027 | ||
1028 | pos = int_bit_position (fld); | |
1029 | size = tree_low_cst (DECL_SIZE (fld), 1); | |
1030 | if (pos <= offset && (pos + size) > offset) | |
1031 | break; | |
1032 | } | |
1033 | if (!fld || TREE_CODE (TREE_TYPE (fld)) != RECORD_TYPE) | |
1034 | return NULL_TREE; | |
1035 | ||
1036 | last_artificial = DECL_ARTIFICIAL (fld); | |
1037 | type = TREE_TYPE (fld); | |
1038 | offset -= pos; | |
1039 | } | |
1040 | /* Artifical sub-objects are ancestors, we do not want to use them for | |
1041 | devirtualization, at least not here. */ | |
1042 | if (last_artificial) | |
1043 | return NULL_TREE; | |
1044 | binfo = TYPE_BINFO (type); | |
1045 | if (!binfo || BINFO_N_BASE_BINFOS (binfo) > 0) | |
1046 | return NULL_TREE; | |
1047 | else | |
1048 | return binfo; | |
1049 | } | |
1050 | ||
cbdd87d4 RG |
1051 | /* Attempt to fold a call statement referenced by the statement iterator GSI. |
1052 | The statement may be replaced by another statement, e.g., if the call | |
1053 | simplifies to a constant value. Return true if any changes were made. | |
1054 | It is assumed that the operands have been previously folded. */ | |
1055 | ||
e021c122 | 1056 | static bool |
ceeffab0 | 1057 | gimple_fold_call (gimple_stmt_iterator *gsi, bool inplace) |
cbdd87d4 RG |
1058 | { |
1059 | gimple stmt = gsi_stmt (*gsi); | |
3b45a007 | 1060 | tree callee; |
e021c122 RG |
1061 | bool changed = false; |
1062 | unsigned i; | |
cbdd87d4 | 1063 | |
e021c122 RG |
1064 | /* Fold *& in call arguments. */ |
1065 | for (i = 0; i < gimple_call_num_args (stmt); ++i) | |
1066 | if (REFERENCE_CLASS_P (gimple_call_arg (stmt, i))) | |
1067 | { | |
1068 | tree tmp = maybe_fold_reference (gimple_call_arg (stmt, i), false); | |
1069 | if (tmp) | |
1070 | { | |
1071 | gimple_call_set_arg (stmt, i, tmp); | |
1072 | changed = true; | |
1073 | } | |
1074 | } | |
3b45a007 RG |
1075 | |
1076 | /* Check for virtual calls that became direct calls. */ | |
1077 | callee = gimple_call_fn (stmt); | |
25583c4f | 1078 | if (callee && TREE_CODE (callee) == OBJ_TYPE_REF) |
3b45a007 | 1079 | { |
49c471e3 MJ |
1080 | if (gimple_call_addr_fndecl (OBJ_TYPE_REF_EXPR (callee)) != NULL_TREE) |
1081 | { | |
1082 | gimple_call_set_fn (stmt, OBJ_TYPE_REF_EXPR (callee)); | |
e021c122 RG |
1083 | changed = true; |
1084 | } | |
1085 | else | |
1086 | { | |
1087 | tree obj = OBJ_TYPE_REF_OBJECT (callee); | |
1088 | tree binfo = gimple_extract_devirt_binfo_from_cst (obj); | |
1089 | if (binfo) | |
1090 | { | |
1091 | HOST_WIDE_INT token | |
1092 | = TREE_INT_CST_LOW (OBJ_TYPE_REF_TOKEN (callee)); | |
1093 | tree fndecl = gimple_get_virt_method_for_binfo (token, binfo); | |
1094 | if (fndecl) | |
1095 | { | |
1096 | gimple_call_set_fndecl (stmt, fndecl); | |
1097 | changed = true; | |
1098 | } | |
1099 | } | |
49c471e3 | 1100 | } |
e021c122 | 1101 | } |
49c471e3 | 1102 | |
e021c122 RG |
1103 | if (inplace) |
1104 | return changed; | |
1105 | ||
1106 | /* Check for builtins that CCP can handle using information not | |
1107 | available in the generic fold routines. */ | |
89faf322 | 1108 | callee = gimple_call_fndecl (stmt); |
e021c122 RG |
1109 | if (callee && DECL_BUILT_IN (callee)) |
1110 | { | |
1111 | tree result = gimple_fold_builtin (stmt); | |
f6dbed32 | 1112 | if (result) |
e021c122 RG |
1113 | { |
1114 | if (!update_call_from_tree (gsi, result)) | |
1115 | gimplify_and_update_call_from_tree (gsi, result); | |
1116 | changed = true; | |
1117 | } | |
3b45a007 RG |
1118 | } |
1119 | ||
e021c122 | 1120 | return changed; |
cbdd87d4 RG |
1121 | } |
1122 | ||
1123 | /* Worker for both fold_stmt and fold_stmt_inplace. The INPLACE argument | |
1124 | distinguishes both cases. */ | |
1125 | ||
1126 | static bool | |
1127 | fold_stmt_1 (gimple_stmt_iterator *gsi, bool inplace) | |
1128 | { | |
1129 | bool changed = false; | |
1130 | gimple stmt = gsi_stmt (*gsi); | |
1131 | unsigned i; | |
a9d24544 JJ |
1132 | gimple_stmt_iterator gsinext = *gsi; |
1133 | gimple next_stmt; | |
1134 | ||
1135 | gsi_next (&gsinext); | |
1136 | next_stmt = gsi_end_p (gsinext) ? NULL : gsi_stmt (gsinext); | |
cbdd87d4 RG |
1137 | |
1138 | /* Fold the main computation performed by the statement. */ | |
1139 | switch (gimple_code (stmt)) | |
1140 | { | |
1141 | case GIMPLE_ASSIGN: | |
1142 | { | |
1143 | unsigned old_num_ops = gimple_num_ops (stmt); | |
5fbcc0ed | 1144 | enum tree_code subcode = gimple_assign_rhs_code (stmt); |
cbdd87d4 | 1145 | tree lhs = gimple_assign_lhs (stmt); |
5fbcc0ed RG |
1146 | tree new_rhs; |
1147 | /* First canonicalize operand order. This avoids building new | |
1148 | trees if this is the only thing fold would later do. */ | |
1149 | if ((commutative_tree_code (subcode) | |
1150 | || commutative_ternary_tree_code (subcode)) | |
1151 | && tree_swap_operands_p (gimple_assign_rhs1 (stmt), | |
1152 | gimple_assign_rhs2 (stmt), false)) | |
1153 | { | |
1154 | tree tem = gimple_assign_rhs1 (stmt); | |
1155 | gimple_assign_set_rhs1 (stmt, gimple_assign_rhs2 (stmt)); | |
1156 | gimple_assign_set_rhs2 (stmt, tem); | |
1157 | changed = true; | |
1158 | } | |
1159 | new_rhs = fold_gimple_assign (gsi); | |
cbdd87d4 RG |
1160 | if (new_rhs |
1161 | && !useless_type_conversion_p (TREE_TYPE (lhs), | |
1162 | TREE_TYPE (new_rhs))) | |
1163 | new_rhs = fold_convert (TREE_TYPE (lhs), new_rhs); | |
1164 | if (new_rhs | |
1165 | && (!inplace | |
1166 | || get_gimple_rhs_num_ops (TREE_CODE (new_rhs)) < old_num_ops)) | |
1167 | { | |
1168 | gimple_assign_set_rhs_from_tree (gsi, new_rhs); | |
1169 | changed = true; | |
1170 | } | |
1171 | break; | |
1172 | } | |
1173 | ||
1174 | case GIMPLE_COND: | |
1175 | changed |= fold_gimple_cond (stmt); | |
1176 | break; | |
1177 | ||
1178 | case GIMPLE_CALL: | |
ceeffab0 | 1179 | changed |= gimple_fold_call (gsi, inplace); |
cbdd87d4 RG |
1180 | break; |
1181 | ||
1182 | case GIMPLE_ASM: | |
1183 | /* Fold *& in asm operands. */ | |
38384150 JJ |
1184 | { |
1185 | size_t noutputs; | |
1186 | const char **oconstraints; | |
1187 | const char *constraint; | |
1188 | bool allows_mem, allows_reg; | |
1189 | ||
1190 | noutputs = gimple_asm_noutputs (stmt); | |
1191 | oconstraints = XALLOCAVEC (const char *, noutputs); | |
1192 | ||
1193 | for (i = 0; i < gimple_asm_noutputs (stmt); ++i) | |
1194 | { | |
1195 | tree link = gimple_asm_output_op (stmt, i); | |
1196 | tree op = TREE_VALUE (link); | |
1197 | oconstraints[i] | |
1198 | = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link))); | |
1199 | if (REFERENCE_CLASS_P (op) | |
1200 | && (op = maybe_fold_reference (op, true)) != NULL_TREE) | |
1201 | { | |
1202 | TREE_VALUE (link) = op; | |
1203 | changed = true; | |
1204 | } | |
1205 | } | |
1206 | for (i = 0; i < gimple_asm_ninputs (stmt); ++i) | |
1207 | { | |
1208 | tree link = gimple_asm_input_op (stmt, i); | |
1209 | tree op = TREE_VALUE (link); | |
1210 | constraint | |
1211 | = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link))); | |
1212 | parse_input_constraint (&constraint, 0, 0, noutputs, 0, | |
1213 | oconstraints, &allows_mem, &allows_reg); | |
1214 | if (REFERENCE_CLASS_P (op) | |
1215 | && (op = maybe_fold_reference (op, !allows_reg && allows_mem)) | |
1216 | != NULL_TREE) | |
1217 | { | |
1218 | TREE_VALUE (link) = op; | |
1219 | changed = true; | |
1220 | } | |
1221 | } | |
1222 | } | |
cbdd87d4 RG |
1223 | break; |
1224 | ||
bd422c4a RG |
1225 | case GIMPLE_DEBUG: |
1226 | if (gimple_debug_bind_p (stmt)) | |
1227 | { | |
1228 | tree val = gimple_debug_bind_get_value (stmt); | |
1229 | if (val | |
1230 | && REFERENCE_CLASS_P (val)) | |
1231 | { | |
1232 | tree tem = maybe_fold_reference (val, false); | |
1233 | if (tem) | |
1234 | { | |
1235 | gimple_debug_bind_set_value (stmt, tem); | |
1236 | changed = true; | |
1237 | } | |
1238 | } | |
3e888a5e RG |
1239 | else if (val |
1240 | && TREE_CODE (val) == ADDR_EXPR) | |
1241 | { | |
1242 | tree ref = TREE_OPERAND (val, 0); | |
1243 | tree tem = maybe_fold_reference (ref, false); | |
1244 | if (tem) | |
1245 | { | |
1246 | tem = build_fold_addr_expr_with_type (tem, TREE_TYPE (val)); | |
1247 | gimple_debug_bind_set_value (stmt, tem); | |
1248 | changed = true; | |
1249 | } | |
1250 | } | |
bd422c4a RG |
1251 | } |
1252 | break; | |
1253 | ||
cbdd87d4 RG |
1254 | default:; |
1255 | } | |
1256 | ||
a9d24544 JJ |
1257 | /* If stmt folds into nothing and it was the last stmt in a bb, |
1258 | don't call gsi_stmt. */ | |
1259 | if (gsi_end_p (*gsi)) | |
1260 | { | |
1261 | gcc_assert (next_stmt == NULL); | |
1262 | return changed; | |
1263 | } | |
1264 | ||
cbdd87d4 RG |
1265 | stmt = gsi_stmt (*gsi); |
1266 | ||
a9d24544 JJ |
1267 | /* Fold *& on the lhs. Don't do this if stmt folded into nothing, |
1268 | as we'd changing the next stmt. */ | |
1269 | if (gimple_has_lhs (stmt) && stmt != next_stmt) | |
cbdd87d4 RG |
1270 | { |
1271 | tree lhs = gimple_get_lhs (stmt); | |
1272 | if (lhs && REFERENCE_CLASS_P (lhs)) | |
1273 | { | |
1274 | tree new_lhs = maybe_fold_reference (lhs, true); | |
1275 | if (new_lhs) | |
1276 | { | |
1277 | gimple_set_lhs (stmt, new_lhs); | |
1278 | changed = true; | |
1279 | } | |
1280 | } | |
1281 | } | |
1282 | ||
1283 | return changed; | |
1284 | } | |
1285 | ||
1286 | /* Fold the statement pointed to by GSI. In some cases, this function may | |
1287 | replace the whole statement with a new one. Returns true iff folding | |
1288 | makes any changes. | |
1289 | The statement pointed to by GSI should be in valid gimple form but may | |
1290 | be in unfolded state as resulting from for example constant propagation | |
1291 | which can produce *&x = 0. */ | |
1292 | ||
1293 | bool | |
1294 | fold_stmt (gimple_stmt_iterator *gsi) | |
1295 | { | |
1296 | return fold_stmt_1 (gsi, false); | |
1297 | } | |
1298 | ||
59401b92 | 1299 | /* Perform the minimal folding on statement *GSI. Only operations like |
cbdd87d4 RG |
1300 | *&x created by constant propagation are handled. The statement cannot |
1301 | be replaced with a new one. Return true if the statement was | |
1302 | changed, false otherwise. | |
59401b92 | 1303 | The statement *GSI should be in valid gimple form but may |
cbdd87d4 RG |
1304 | be in unfolded state as resulting from for example constant propagation |
1305 | which can produce *&x = 0. */ | |
1306 | ||
1307 | bool | |
59401b92 | 1308 | fold_stmt_inplace (gimple_stmt_iterator *gsi) |
cbdd87d4 | 1309 | { |
59401b92 RG |
1310 | gimple stmt = gsi_stmt (*gsi); |
1311 | bool changed = fold_stmt_1 (gsi, true); | |
1312 | gcc_assert (gsi_stmt (*gsi) == stmt); | |
cbdd87d4 RG |
1313 | return changed; |
1314 | } | |
1315 | ||
e89065a1 SL |
1316 | /* Canonicalize and possibly invert the boolean EXPR; return NULL_TREE |
1317 | if EXPR is null or we don't know how. | |
1318 | If non-null, the result always has boolean type. */ | |
1319 | ||
1320 | static tree | |
1321 | canonicalize_bool (tree expr, bool invert) | |
1322 | { | |
1323 | if (!expr) | |
1324 | return NULL_TREE; | |
1325 | else if (invert) | |
1326 | { | |
1327 | if (integer_nonzerop (expr)) | |
1328 | return boolean_false_node; | |
1329 | else if (integer_zerop (expr)) | |
1330 | return boolean_true_node; | |
1331 | else if (TREE_CODE (expr) == SSA_NAME) | |
1332 | return fold_build2 (EQ_EXPR, boolean_type_node, expr, | |
1333 | build_int_cst (TREE_TYPE (expr), 0)); | |
1334 | else if (TREE_CODE_CLASS (TREE_CODE (expr)) == tcc_comparison) | |
1335 | return fold_build2 (invert_tree_comparison (TREE_CODE (expr), false), | |
1336 | boolean_type_node, | |
1337 | TREE_OPERAND (expr, 0), | |
1338 | TREE_OPERAND (expr, 1)); | |
1339 | else | |
1340 | return NULL_TREE; | |
1341 | } | |
1342 | else | |
1343 | { | |
1344 | if (TREE_CODE (TREE_TYPE (expr)) == BOOLEAN_TYPE) | |
1345 | return expr; | |
1346 | if (integer_nonzerop (expr)) | |
1347 | return boolean_true_node; | |
1348 | else if (integer_zerop (expr)) | |
1349 | return boolean_false_node; | |
1350 | else if (TREE_CODE (expr) == SSA_NAME) | |
1351 | return fold_build2 (NE_EXPR, boolean_type_node, expr, | |
1352 | build_int_cst (TREE_TYPE (expr), 0)); | |
1353 | else if (TREE_CODE_CLASS (TREE_CODE (expr)) == tcc_comparison) | |
1354 | return fold_build2 (TREE_CODE (expr), | |
1355 | boolean_type_node, | |
1356 | TREE_OPERAND (expr, 0), | |
1357 | TREE_OPERAND (expr, 1)); | |
1358 | else | |
1359 | return NULL_TREE; | |
1360 | } | |
1361 | } | |
1362 | ||
1363 | /* Check to see if a boolean expression EXPR is logically equivalent to the | |
1364 | comparison (OP1 CODE OP2). Check for various identities involving | |
1365 | SSA_NAMEs. */ | |
1366 | ||
1367 | static bool | |
1368 | same_bool_comparison_p (const_tree expr, enum tree_code code, | |
1369 | const_tree op1, const_tree op2) | |
1370 | { | |
1371 | gimple s; | |
1372 | ||
1373 | /* The obvious case. */ | |
1374 | if (TREE_CODE (expr) == code | |
1375 | && operand_equal_p (TREE_OPERAND (expr, 0), op1, 0) | |
1376 | && operand_equal_p (TREE_OPERAND (expr, 1), op2, 0)) | |
1377 | return true; | |
1378 | ||
1379 | /* Check for comparing (name, name != 0) and the case where expr | |
1380 | is an SSA_NAME with a definition matching the comparison. */ | |
1381 | if (TREE_CODE (expr) == SSA_NAME | |
1382 | && TREE_CODE (TREE_TYPE (expr)) == BOOLEAN_TYPE) | |
1383 | { | |
1384 | if (operand_equal_p (expr, op1, 0)) | |
1385 | return ((code == NE_EXPR && integer_zerop (op2)) | |
1386 | || (code == EQ_EXPR && integer_nonzerop (op2))); | |
1387 | s = SSA_NAME_DEF_STMT (expr); | |
1388 | if (is_gimple_assign (s) | |
1389 | && gimple_assign_rhs_code (s) == code | |
1390 | && operand_equal_p (gimple_assign_rhs1 (s), op1, 0) | |
1391 | && operand_equal_p (gimple_assign_rhs2 (s), op2, 0)) | |
1392 | return true; | |
1393 | } | |
1394 | ||
1395 | /* If op1 is of the form (name != 0) or (name == 0), and the definition | |
1396 | of name is a comparison, recurse. */ | |
1397 | if (TREE_CODE (op1) == SSA_NAME | |
1398 | && TREE_CODE (TREE_TYPE (op1)) == BOOLEAN_TYPE) | |
1399 | { | |
1400 | s = SSA_NAME_DEF_STMT (op1); | |
1401 | if (is_gimple_assign (s) | |
1402 | && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison) | |
1403 | { | |
1404 | enum tree_code c = gimple_assign_rhs_code (s); | |
1405 | if ((c == NE_EXPR && integer_zerop (op2)) | |
1406 | || (c == EQ_EXPR && integer_nonzerop (op2))) | |
1407 | return same_bool_comparison_p (expr, c, | |
1408 | gimple_assign_rhs1 (s), | |
1409 | gimple_assign_rhs2 (s)); | |
1410 | if ((c == EQ_EXPR && integer_zerop (op2)) | |
1411 | || (c == NE_EXPR && integer_nonzerop (op2))) | |
1412 | return same_bool_comparison_p (expr, | |
1413 | invert_tree_comparison (c, false), | |
1414 | gimple_assign_rhs1 (s), | |
1415 | gimple_assign_rhs2 (s)); | |
1416 | } | |
1417 | } | |
1418 | return false; | |
1419 | } | |
1420 | ||
1421 | /* Check to see if two boolean expressions OP1 and OP2 are logically | |
1422 | equivalent. */ | |
1423 | ||
1424 | static bool | |
1425 | same_bool_result_p (const_tree op1, const_tree op2) | |
1426 | { | |
1427 | /* Simple cases first. */ | |
1428 | if (operand_equal_p (op1, op2, 0)) | |
1429 | return true; | |
1430 | ||
1431 | /* Check the cases where at least one of the operands is a comparison. | |
1432 | These are a bit smarter than operand_equal_p in that they apply some | |
1433 | identifies on SSA_NAMEs. */ | |
1434 | if (TREE_CODE_CLASS (TREE_CODE (op2)) == tcc_comparison | |
1435 | && same_bool_comparison_p (op1, TREE_CODE (op2), | |
1436 | TREE_OPERAND (op2, 0), | |
1437 | TREE_OPERAND (op2, 1))) | |
1438 | return true; | |
1439 | if (TREE_CODE_CLASS (TREE_CODE (op1)) == tcc_comparison | |
1440 | && same_bool_comparison_p (op2, TREE_CODE (op1), | |
1441 | TREE_OPERAND (op1, 0), | |
1442 | TREE_OPERAND (op1, 1))) | |
1443 | return true; | |
1444 | ||
1445 | /* Default case. */ | |
1446 | return false; | |
1447 | } | |
1448 | ||
1449 | /* Forward declarations for some mutually recursive functions. */ | |
1450 | ||
1451 | static tree | |
1452 | and_comparisons_1 (enum tree_code code1, tree op1a, tree op1b, | |
1453 | enum tree_code code2, tree op2a, tree op2b); | |
1454 | static tree | |
1455 | and_var_with_comparison (tree var, bool invert, | |
1456 | enum tree_code code2, tree op2a, tree op2b); | |
1457 | static tree | |
1458 | and_var_with_comparison_1 (gimple stmt, | |
1459 | enum tree_code code2, tree op2a, tree op2b); | |
1460 | static tree | |
1461 | or_comparisons_1 (enum tree_code code1, tree op1a, tree op1b, | |
1462 | enum tree_code code2, tree op2a, tree op2b); | |
1463 | static tree | |
1464 | or_var_with_comparison (tree var, bool invert, | |
1465 | enum tree_code code2, tree op2a, tree op2b); | |
1466 | static tree | |
1467 | or_var_with_comparison_1 (gimple stmt, | |
1468 | enum tree_code code2, tree op2a, tree op2b); | |
1469 | ||
1470 | /* Helper function for and_comparisons_1: try to simplify the AND of the | |
1471 | ssa variable VAR with the comparison specified by (OP2A CODE2 OP2B). | |
1472 | If INVERT is true, invert the value of the VAR before doing the AND. | |
1473 | Return NULL_EXPR if we can't simplify this to a single expression. */ | |
1474 | ||
1475 | static tree | |
1476 | and_var_with_comparison (tree var, bool invert, | |
1477 | enum tree_code code2, tree op2a, tree op2b) | |
1478 | { | |
1479 | tree t; | |
1480 | gimple stmt = SSA_NAME_DEF_STMT (var); | |
1481 | ||
1482 | /* We can only deal with variables whose definitions are assignments. */ | |
1483 | if (!is_gimple_assign (stmt)) | |
1484 | return NULL_TREE; | |
1485 | ||
1486 | /* If we have an inverted comparison, apply DeMorgan's law and rewrite | |
1487 | !var AND (op2a code2 op2b) => !(var OR !(op2a code2 op2b)) | |
1488 | Then we only have to consider the simpler non-inverted cases. */ | |
1489 | if (invert) | |
1490 | t = or_var_with_comparison_1 (stmt, | |
1491 | invert_tree_comparison (code2, false), | |
1492 | op2a, op2b); | |
1493 | else | |
1494 | t = and_var_with_comparison_1 (stmt, code2, op2a, op2b); | |
1495 | return canonicalize_bool (t, invert); | |
1496 | } | |
1497 | ||
1498 | /* Try to simplify the AND of the ssa variable defined by the assignment | |
1499 | STMT with the comparison specified by (OP2A CODE2 OP2B). | |
1500 | Return NULL_EXPR if we can't simplify this to a single expression. */ | |
1501 | ||
1502 | static tree | |
1503 | and_var_with_comparison_1 (gimple stmt, | |
1504 | enum tree_code code2, tree op2a, tree op2b) | |
1505 | { | |
1506 | tree var = gimple_assign_lhs (stmt); | |
1507 | tree true_test_var = NULL_TREE; | |
1508 | tree false_test_var = NULL_TREE; | |
1509 | enum tree_code innercode = gimple_assign_rhs_code (stmt); | |
1510 | ||
1511 | /* Check for identities like (var AND (var == 0)) => false. */ | |
1512 | if (TREE_CODE (op2a) == SSA_NAME | |
1513 | && TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE) | |
1514 | { | |
1515 | if ((code2 == NE_EXPR && integer_zerop (op2b)) | |
1516 | || (code2 == EQ_EXPR && integer_nonzerop (op2b))) | |
1517 | { | |
1518 | true_test_var = op2a; | |
1519 | if (var == true_test_var) | |
1520 | return var; | |
1521 | } | |
1522 | else if ((code2 == EQ_EXPR && integer_zerop (op2b)) | |
1523 | || (code2 == NE_EXPR && integer_nonzerop (op2b))) | |
1524 | { | |
1525 | false_test_var = op2a; | |
1526 | if (var == false_test_var) | |
1527 | return boolean_false_node; | |
1528 | } | |
1529 | } | |
1530 | ||
1531 | /* If the definition is a comparison, recurse on it. */ | |
1532 | if (TREE_CODE_CLASS (innercode) == tcc_comparison) | |
1533 | { | |
1534 | tree t = and_comparisons_1 (innercode, | |
1535 | gimple_assign_rhs1 (stmt), | |
1536 | gimple_assign_rhs2 (stmt), | |
1537 | code2, | |
1538 | op2a, | |
1539 | op2b); | |
1540 | if (t) | |
1541 | return t; | |
1542 | } | |
1543 | ||
1544 | /* If the definition is an AND or OR expression, we may be able to | |
1545 | simplify by reassociating. */ | |
eb9820c0 KT |
1546 | if (TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE |
1547 | && (innercode == BIT_AND_EXPR || innercode == BIT_IOR_EXPR)) | |
e89065a1 SL |
1548 | { |
1549 | tree inner1 = gimple_assign_rhs1 (stmt); | |
1550 | tree inner2 = gimple_assign_rhs2 (stmt); | |
1551 | gimple s; | |
1552 | tree t; | |
1553 | tree partial = NULL_TREE; | |
eb9820c0 | 1554 | bool is_and = (innercode == BIT_AND_EXPR); |
e89065a1 SL |
1555 | |
1556 | /* Check for boolean identities that don't require recursive examination | |
1557 | of inner1/inner2: | |
1558 | inner1 AND (inner1 AND inner2) => inner1 AND inner2 => var | |
1559 | inner1 AND (inner1 OR inner2) => inner1 | |
1560 | !inner1 AND (inner1 AND inner2) => false | |
1561 | !inner1 AND (inner1 OR inner2) => !inner1 AND inner2 | |
1562 | Likewise for similar cases involving inner2. */ | |
1563 | if (inner1 == true_test_var) | |
1564 | return (is_and ? var : inner1); | |
1565 | else if (inner2 == true_test_var) | |
1566 | return (is_and ? var : inner2); | |
1567 | else if (inner1 == false_test_var) | |
1568 | return (is_and | |
1569 | ? boolean_false_node | |
1570 | : and_var_with_comparison (inner2, false, code2, op2a, op2b)); | |
1571 | else if (inner2 == false_test_var) | |
1572 | return (is_and | |
1573 | ? boolean_false_node | |
1574 | : and_var_with_comparison (inner1, false, code2, op2a, op2b)); | |
1575 | ||
1576 | /* Next, redistribute/reassociate the AND across the inner tests. | |
1577 | Compute the first partial result, (inner1 AND (op2a code op2b)) */ | |
1578 | if (TREE_CODE (inner1) == SSA_NAME | |
1579 | && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner1)) | |
1580 | && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison | |
1581 | && (t = maybe_fold_and_comparisons (gimple_assign_rhs_code (s), | |
1582 | gimple_assign_rhs1 (s), | |
1583 | gimple_assign_rhs2 (s), | |
1584 | code2, op2a, op2b))) | |
1585 | { | |
1586 | /* Handle the AND case, where we are reassociating: | |
1587 | (inner1 AND inner2) AND (op2a code2 op2b) | |
1588 | => (t AND inner2) | |
1589 | If the partial result t is a constant, we win. Otherwise | |
1590 | continue on to try reassociating with the other inner test. */ | |
1591 | if (is_and) | |
1592 | { | |
1593 | if (integer_onep (t)) | |
1594 | return inner2; | |
1595 | else if (integer_zerop (t)) | |
1596 | return boolean_false_node; | |
1597 | } | |
1598 | ||
1599 | /* Handle the OR case, where we are redistributing: | |
1600 | (inner1 OR inner2) AND (op2a code2 op2b) | |
1601 | => (t OR (inner2 AND (op2a code2 op2b))) */ | |
8236c8eb JJ |
1602 | else if (integer_onep (t)) |
1603 | return boolean_true_node; | |
1604 | ||
1605 | /* Save partial result for later. */ | |
1606 | partial = t; | |
e89065a1 SL |
1607 | } |
1608 | ||
1609 | /* Compute the second partial result, (inner2 AND (op2a code op2b)) */ | |
1610 | if (TREE_CODE (inner2) == SSA_NAME | |
1611 | && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner2)) | |
1612 | && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison | |
1613 | && (t = maybe_fold_and_comparisons (gimple_assign_rhs_code (s), | |
1614 | gimple_assign_rhs1 (s), | |
1615 | gimple_assign_rhs2 (s), | |
1616 | code2, op2a, op2b))) | |
1617 | { | |
1618 | /* Handle the AND case, where we are reassociating: | |
1619 | (inner1 AND inner2) AND (op2a code2 op2b) | |
1620 | => (inner1 AND t) */ | |
1621 | if (is_and) | |
1622 | { | |
1623 | if (integer_onep (t)) | |
1624 | return inner1; | |
1625 | else if (integer_zerop (t)) | |
1626 | return boolean_false_node; | |
8236c8eb JJ |
1627 | /* If both are the same, we can apply the identity |
1628 | (x AND x) == x. */ | |
1629 | else if (partial && same_bool_result_p (t, partial)) | |
1630 | return t; | |
e89065a1 SL |
1631 | } |
1632 | ||
1633 | /* Handle the OR case. where we are redistributing: | |
1634 | (inner1 OR inner2) AND (op2a code2 op2b) | |
1635 | => (t OR (inner1 AND (op2a code2 op2b))) | |
1636 | => (t OR partial) */ | |
1637 | else | |
1638 | { | |
1639 | if (integer_onep (t)) | |
1640 | return boolean_true_node; | |
1641 | else if (partial) | |
1642 | { | |
1643 | /* We already got a simplification for the other | |
1644 | operand to the redistributed OR expression. The | |
1645 | interesting case is when at least one is false. | |
1646 | Or, if both are the same, we can apply the identity | |
1647 | (x OR x) == x. */ | |
1648 | if (integer_zerop (partial)) | |
1649 | return t; | |
1650 | else if (integer_zerop (t)) | |
1651 | return partial; | |
1652 | else if (same_bool_result_p (t, partial)) | |
1653 | return t; | |
1654 | } | |
1655 | } | |
1656 | } | |
1657 | } | |
1658 | return NULL_TREE; | |
1659 | } | |
1660 | ||
1661 | /* Try to simplify the AND of two comparisons defined by | |
1662 | (OP1A CODE1 OP1B) and (OP2A CODE2 OP2B), respectively. | |
1663 | If this can be done without constructing an intermediate value, | |
1664 | return the resulting tree; otherwise NULL_TREE is returned. | |
1665 | This function is deliberately asymmetric as it recurses on SSA_DEFs | |
1666 | in the first comparison but not the second. */ | |
1667 | ||
1668 | static tree | |
1669 | and_comparisons_1 (enum tree_code code1, tree op1a, tree op1b, | |
1670 | enum tree_code code2, tree op2a, tree op2b) | |
1671 | { | |
1672 | /* First check for ((x CODE1 y) AND (x CODE2 y)). */ | |
1673 | if (operand_equal_p (op1a, op2a, 0) | |
1674 | && operand_equal_p (op1b, op2b, 0)) | |
1675 | { | |
eb9820c0 | 1676 | /* Result will be either NULL_TREE, or a combined comparison. */ |
e89065a1 SL |
1677 | tree t = combine_comparisons (UNKNOWN_LOCATION, |
1678 | TRUTH_ANDIF_EXPR, code1, code2, | |
1679 | boolean_type_node, op1a, op1b); | |
1680 | if (t) | |
1681 | return t; | |
1682 | } | |
1683 | ||
1684 | /* Likewise the swapped case of the above. */ | |
1685 | if (operand_equal_p (op1a, op2b, 0) | |
1686 | && operand_equal_p (op1b, op2a, 0)) | |
1687 | { | |
eb9820c0 | 1688 | /* Result will be either NULL_TREE, or a combined comparison. */ |
e89065a1 SL |
1689 | tree t = combine_comparisons (UNKNOWN_LOCATION, |
1690 | TRUTH_ANDIF_EXPR, code1, | |
1691 | swap_tree_comparison (code2), | |
1692 | boolean_type_node, op1a, op1b); | |
1693 | if (t) | |
1694 | return t; | |
1695 | } | |
1696 | ||
1697 | /* If both comparisons are of the same value against constants, we might | |
1698 | be able to merge them. */ | |
1699 | if (operand_equal_p (op1a, op2a, 0) | |
1700 | && TREE_CODE (op1b) == INTEGER_CST | |
1701 | && TREE_CODE (op2b) == INTEGER_CST) | |
1702 | { | |
1703 | int cmp = tree_int_cst_compare (op1b, op2b); | |
1704 | ||
1705 | /* If we have (op1a == op1b), we should either be able to | |
1706 | return that or FALSE, depending on whether the constant op1b | |
1707 | also satisfies the other comparison against op2b. */ | |
1708 | if (code1 == EQ_EXPR) | |
1709 | { | |
1710 | bool done = true; | |
1711 | bool val; | |
1712 | switch (code2) | |
1713 | { | |
1714 | case EQ_EXPR: val = (cmp == 0); break; | |
1715 | case NE_EXPR: val = (cmp != 0); break; | |
1716 | case LT_EXPR: val = (cmp < 0); break; | |
1717 | case GT_EXPR: val = (cmp > 0); break; | |
1718 | case LE_EXPR: val = (cmp <= 0); break; | |
1719 | case GE_EXPR: val = (cmp >= 0); break; | |
1720 | default: done = false; | |
1721 | } | |
1722 | if (done) | |
1723 | { | |
1724 | if (val) | |
1725 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
1726 | else | |
1727 | return boolean_false_node; | |
1728 | } | |
1729 | } | |
1730 | /* Likewise if the second comparison is an == comparison. */ | |
1731 | else if (code2 == EQ_EXPR) | |
1732 | { | |
1733 | bool done = true; | |
1734 | bool val; | |
1735 | switch (code1) | |
1736 | { | |
1737 | case EQ_EXPR: val = (cmp == 0); break; | |
1738 | case NE_EXPR: val = (cmp != 0); break; | |
1739 | case LT_EXPR: val = (cmp > 0); break; | |
1740 | case GT_EXPR: val = (cmp < 0); break; | |
1741 | case LE_EXPR: val = (cmp >= 0); break; | |
1742 | case GE_EXPR: val = (cmp <= 0); break; | |
1743 | default: done = false; | |
1744 | } | |
1745 | if (done) | |
1746 | { | |
1747 | if (val) | |
1748 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
1749 | else | |
1750 | return boolean_false_node; | |
1751 | } | |
1752 | } | |
1753 | ||
1754 | /* Same business with inequality tests. */ | |
1755 | else if (code1 == NE_EXPR) | |
1756 | { | |
1757 | bool val; | |
1758 | switch (code2) | |
1759 | { | |
1760 | case EQ_EXPR: val = (cmp != 0); break; | |
1761 | case NE_EXPR: val = (cmp == 0); break; | |
1762 | case LT_EXPR: val = (cmp >= 0); break; | |
1763 | case GT_EXPR: val = (cmp <= 0); break; | |
1764 | case LE_EXPR: val = (cmp > 0); break; | |
1765 | case GE_EXPR: val = (cmp < 0); break; | |
1766 | default: | |
1767 | val = false; | |
1768 | } | |
1769 | if (val) | |
1770 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
1771 | } | |
1772 | else if (code2 == NE_EXPR) | |
1773 | { | |
1774 | bool val; | |
1775 | switch (code1) | |
1776 | { | |
1777 | case EQ_EXPR: val = (cmp == 0); break; | |
1778 | case NE_EXPR: val = (cmp != 0); break; | |
1779 | case LT_EXPR: val = (cmp <= 0); break; | |
1780 | case GT_EXPR: val = (cmp >= 0); break; | |
1781 | case LE_EXPR: val = (cmp < 0); break; | |
1782 | case GE_EXPR: val = (cmp > 0); break; | |
1783 | default: | |
1784 | val = false; | |
1785 | } | |
1786 | if (val) | |
1787 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
1788 | } | |
1789 | ||
1790 | /* Chose the more restrictive of two < or <= comparisons. */ | |
1791 | else if ((code1 == LT_EXPR || code1 == LE_EXPR) | |
1792 | && (code2 == LT_EXPR || code2 == LE_EXPR)) | |
1793 | { | |
1794 | if ((cmp < 0) || (cmp == 0 && code1 == LT_EXPR)) | |
1795 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
1796 | else | |
1797 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
1798 | } | |
1799 | ||
1800 | /* Likewise chose the more restrictive of two > or >= comparisons. */ | |
1801 | else if ((code1 == GT_EXPR || code1 == GE_EXPR) | |
1802 | && (code2 == GT_EXPR || code2 == GE_EXPR)) | |
1803 | { | |
1804 | if ((cmp > 0) || (cmp == 0 && code1 == GT_EXPR)) | |
1805 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
1806 | else | |
1807 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
1808 | } | |
1809 | ||
1810 | /* Check for singleton ranges. */ | |
1811 | else if (cmp == 0 | |
1812 | && ((code1 == LE_EXPR && code2 == GE_EXPR) | |
1813 | || (code1 == GE_EXPR && code2 == LE_EXPR))) | |
1814 | return fold_build2 (EQ_EXPR, boolean_type_node, op1a, op2b); | |
1815 | ||
1816 | /* Check for disjoint ranges. */ | |
1817 | else if (cmp <= 0 | |
1818 | && (code1 == LT_EXPR || code1 == LE_EXPR) | |
1819 | && (code2 == GT_EXPR || code2 == GE_EXPR)) | |
1820 | return boolean_false_node; | |
1821 | else if (cmp >= 0 | |
1822 | && (code1 == GT_EXPR || code1 == GE_EXPR) | |
1823 | && (code2 == LT_EXPR || code2 == LE_EXPR)) | |
1824 | return boolean_false_node; | |
1825 | } | |
1826 | ||
1827 | /* Perhaps the first comparison is (NAME != 0) or (NAME == 1) where | |
1828 | NAME's definition is a truth value. See if there are any simplifications | |
1829 | that can be done against the NAME's definition. */ | |
1830 | if (TREE_CODE (op1a) == SSA_NAME | |
1831 | && (code1 == NE_EXPR || code1 == EQ_EXPR) | |
1832 | && (integer_zerop (op1b) || integer_onep (op1b))) | |
1833 | { | |
1834 | bool invert = ((code1 == EQ_EXPR && integer_zerop (op1b)) | |
1835 | || (code1 == NE_EXPR && integer_onep (op1b))); | |
1836 | gimple stmt = SSA_NAME_DEF_STMT (op1a); | |
1837 | switch (gimple_code (stmt)) | |
1838 | { | |
1839 | case GIMPLE_ASSIGN: | |
1840 | /* Try to simplify by copy-propagating the definition. */ | |
1841 | return and_var_with_comparison (op1a, invert, code2, op2a, op2b); | |
1842 | ||
1843 | case GIMPLE_PHI: | |
1844 | /* If every argument to the PHI produces the same result when | |
1845 | ANDed with the second comparison, we win. | |
1846 | Do not do this unless the type is bool since we need a bool | |
1847 | result here anyway. */ | |
1848 | if (TREE_CODE (TREE_TYPE (op1a)) == BOOLEAN_TYPE) | |
1849 | { | |
1850 | tree result = NULL_TREE; | |
1851 | unsigned i; | |
1852 | for (i = 0; i < gimple_phi_num_args (stmt); i++) | |
1853 | { | |
1854 | tree arg = gimple_phi_arg_def (stmt, i); | |
1855 | ||
1856 | /* If this PHI has itself as an argument, ignore it. | |
1857 | If all the other args produce the same result, | |
1858 | we're still OK. */ | |
1859 | if (arg == gimple_phi_result (stmt)) | |
1860 | continue; | |
1861 | else if (TREE_CODE (arg) == INTEGER_CST) | |
1862 | { | |
1863 | if (invert ? integer_nonzerop (arg) : integer_zerop (arg)) | |
1864 | { | |
1865 | if (!result) | |
1866 | result = boolean_false_node; | |
1867 | else if (!integer_zerop (result)) | |
1868 | return NULL_TREE; | |
1869 | } | |
1870 | else if (!result) | |
1871 | result = fold_build2 (code2, boolean_type_node, | |
1872 | op2a, op2b); | |
1873 | else if (!same_bool_comparison_p (result, | |
1874 | code2, op2a, op2b)) | |
1875 | return NULL_TREE; | |
1876 | } | |
0e8b84ec JJ |
1877 | else if (TREE_CODE (arg) == SSA_NAME |
1878 | && !SSA_NAME_IS_DEFAULT_DEF (arg)) | |
e89065a1 | 1879 | { |
6c66f733 JJ |
1880 | tree temp; |
1881 | gimple def_stmt = SSA_NAME_DEF_STMT (arg); | |
1882 | /* In simple cases we can look through PHI nodes, | |
1883 | but we have to be careful with loops. | |
1884 | See PR49073. */ | |
1885 | if (! dom_info_available_p (CDI_DOMINATORS) | |
1886 | || gimple_bb (def_stmt) == gimple_bb (stmt) | |
1887 | || dominated_by_p (CDI_DOMINATORS, | |
1888 | gimple_bb (def_stmt), | |
1889 | gimple_bb (stmt))) | |
1890 | return NULL_TREE; | |
1891 | temp = and_var_with_comparison (arg, invert, code2, | |
1892 | op2a, op2b); | |
e89065a1 SL |
1893 | if (!temp) |
1894 | return NULL_TREE; | |
1895 | else if (!result) | |
1896 | result = temp; | |
1897 | else if (!same_bool_result_p (result, temp)) | |
1898 | return NULL_TREE; | |
1899 | } | |
1900 | else | |
1901 | return NULL_TREE; | |
1902 | } | |
1903 | return result; | |
1904 | } | |
1905 | ||
1906 | default: | |
1907 | break; | |
1908 | } | |
1909 | } | |
1910 | return NULL_TREE; | |
1911 | } | |
1912 | ||
1913 | /* Try to simplify the AND of two comparisons, specified by | |
1914 | (OP1A CODE1 OP1B) and (OP2B CODE2 OP2B), respectively. | |
1915 | If this can be simplified to a single expression (without requiring | |
1916 | introducing more SSA variables to hold intermediate values), | |
1917 | return the resulting tree. Otherwise return NULL_TREE. | |
1918 | If the result expression is non-null, it has boolean type. */ | |
1919 | ||
1920 | tree | |
1921 | maybe_fold_and_comparisons (enum tree_code code1, tree op1a, tree op1b, | |
1922 | enum tree_code code2, tree op2a, tree op2b) | |
1923 | { | |
1924 | tree t = and_comparisons_1 (code1, op1a, op1b, code2, op2a, op2b); | |
1925 | if (t) | |
1926 | return t; | |
1927 | else | |
1928 | return and_comparisons_1 (code2, op2a, op2b, code1, op1a, op1b); | |
1929 | } | |
1930 | ||
1931 | /* Helper function for or_comparisons_1: try to simplify the OR of the | |
1932 | ssa variable VAR with the comparison specified by (OP2A CODE2 OP2B). | |
1933 | If INVERT is true, invert the value of VAR before doing the OR. | |
1934 | Return NULL_EXPR if we can't simplify this to a single expression. */ | |
1935 | ||
1936 | static tree | |
1937 | or_var_with_comparison (tree var, bool invert, | |
1938 | enum tree_code code2, tree op2a, tree op2b) | |
1939 | { | |
1940 | tree t; | |
1941 | gimple stmt = SSA_NAME_DEF_STMT (var); | |
1942 | ||
1943 | /* We can only deal with variables whose definitions are assignments. */ | |
1944 | if (!is_gimple_assign (stmt)) | |
1945 | return NULL_TREE; | |
1946 | ||
1947 | /* If we have an inverted comparison, apply DeMorgan's law and rewrite | |
1948 | !var OR (op2a code2 op2b) => !(var AND !(op2a code2 op2b)) | |
1949 | Then we only have to consider the simpler non-inverted cases. */ | |
1950 | if (invert) | |
1951 | t = and_var_with_comparison_1 (stmt, | |
1952 | invert_tree_comparison (code2, false), | |
1953 | op2a, op2b); | |
1954 | else | |
1955 | t = or_var_with_comparison_1 (stmt, code2, op2a, op2b); | |
1956 | return canonicalize_bool (t, invert); | |
1957 | } | |
1958 | ||
1959 | /* Try to simplify the OR of the ssa variable defined by the assignment | |
1960 | STMT with the comparison specified by (OP2A CODE2 OP2B). | |
1961 | Return NULL_EXPR if we can't simplify this to a single expression. */ | |
1962 | ||
1963 | static tree | |
1964 | or_var_with_comparison_1 (gimple stmt, | |
1965 | enum tree_code code2, tree op2a, tree op2b) | |
1966 | { | |
1967 | tree var = gimple_assign_lhs (stmt); | |
1968 | tree true_test_var = NULL_TREE; | |
1969 | tree false_test_var = NULL_TREE; | |
1970 | enum tree_code innercode = gimple_assign_rhs_code (stmt); | |
1971 | ||
1972 | /* Check for identities like (var OR (var != 0)) => true . */ | |
1973 | if (TREE_CODE (op2a) == SSA_NAME | |
1974 | && TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE) | |
1975 | { | |
1976 | if ((code2 == NE_EXPR && integer_zerop (op2b)) | |
1977 | || (code2 == EQ_EXPR && integer_nonzerop (op2b))) | |
1978 | { | |
1979 | true_test_var = op2a; | |
1980 | if (var == true_test_var) | |
1981 | return var; | |
1982 | } | |
1983 | else if ((code2 == EQ_EXPR && integer_zerop (op2b)) | |
1984 | || (code2 == NE_EXPR && integer_nonzerop (op2b))) | |
1985 | { | |
1986 | false_test_var = op2a; | |
1987 | if (var == false_test_var) | |
1988 | return boolean_true_node; | |
1989 | } | |
1990 | } | |
1991 | ||
1992 | /* If the definition is a comparison, recurse on it. */ | |
1993 | if (TREE_CODE_CLASS (innercode) == tcc_comparison) | |
1994 | { | |
1995 | tree t = or_comparisons_1 (innercode, | |
1996 | gimple_assign_rhs1 (stmt), | |
1997 | gimple_assign_rhs2 (stmt), | |
1998 | code2, | |
1999 | op2a, | |
2000 | op2b); | |
2001 | if (t) | |
2002 | return t; | |
2003 | } | |
2004 | ||
2005 | /* If the definition is an AND or OR expression, we may be able to | |
2006 | simplify by reassociating. */ | |
eb9820c0 KT |
2007 | if (TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE |
2008 | && (innercode == BIT_AND_EXPR || innercode == BIT_IOR_EXPR)) | |
e89065a1 SL |
2009 | { |
2010 | tree inner1 = gimple_assign_rhs1 (stmt); | |
2011 | tree inner2 = gimple_assign_rhs2 (stmt); | |
2012 | gimple s; | |
2013 | tree t; | |
2014 | tree partial = NULL_TREE; | |
eb9820c0 | 2015 | bool is_or = (innercode == BIT_IOR_EXPR); |
e89065a1 SL |
2016 | |
2017 | /* Check for boolean identities that don't require recursive examination | |
2018 | of inner1/inner2: | |
2019 | inner1 OR (inner1 OR inner2) => inner1 OR inner2 => var | |
2020 | inner1 OR (inner1 AND inner2) => inner1 | |
2021 | !inner1 OR (inner1 OR inner2) => true | |
2022 | !inner1 OR (inner1 AND inner2) => !inner1 OR inner2 | |
2023 | */ | |
2024 | if (inner1 == true_test_var) | |
2025 | return (is_or ? var : inner1); | |
2026 | else if (inner2 == true_test_var) | |
2027 | return (is_or ? var : inner2); | |
2028 | else if (inner1 == false_test_var) | |
2029 | return (is_or | |
2030 | ? boolean_true_node | |
2031 | : or_var_with_comparison (inner2, false, code2, op2a, op2b)); | |
2032 | else if (inner2 == false_test_var) | |
2033 | return (is_or | |
2034 | ? boolean_true_node | |
2035 | : or_var_with_comparison (inner1, false, code2, op2a, op2b)); | |
2036 | ||
2037 | /* Next, redistribute/reassociate the OR across the inner tests. | |
2038 | Compute the first partial result, (inner1 OR (op2a code op2b)) */ | |
2039 | if (TREE_CODE (inner1) == SSA_NAME | |
2040 | && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner1)) | |
2041 | && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison | |
2042 | && (t = maybe_fold_or_comparisons (gimple_assign_rhs_code (s), | |
2043 | gimple_assign_rhs1 (s), | |
2044 | gimple_assign_rhs2 (s), | |
2045 | code2, op2a, op2b))) | |
2046 | { | |
2047 | /* Handle the OR case, where we are reassociating: | |
2048 | (inner1 OR inner2) OR (op2a code2 op2b) | |
2049 | => (t OR inner2) | |
2050 | If the partial result t is a constant, we win. Otherwise | |
2051 | continue on to try reassociating with the other inner test. */ | |
8236c8eb | 2052 | if (is_or) |
e89065a1 SL |
2053 | { |
2054 | if (integer_onep (t)) | |
2055 | return boolean_true_node; | |
2056 | else if (integer_zerop (t)) | |
2057 | return inner2; | |
2058 | } | |
2059 | ||
2060 | /* Handle the AND case, where we are redistributing: | |
2061 | (inner1 AND inner2) OR (op2a code2 op2b) | |
2062 | => (t AND (inner2 OR (op2a code op2b))) */ | |
8236c8eb JJ |
2063 | else if (integer_zerop (t)) |
2064 | return boolean_false_node; | |
2065 | ||
2066 | /* Save partial result for later. */ | |
2067 | partial = t; | |
e89065a1 SL |
2068 | } |
2069 | ||
2070 | /* Compute the second partial result, (inner2 OR (op2a code op2b)) */ | |
2071 | if (TREE_CODE (inner2) == SSA_NAME | |
2072 | && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner2)) | |
2073 | && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison | |
2074 | && (t = maybe_fold_or_comparisons (gimple_assign_rhs_code (s), | |
2075 | gimple_assign_rhs1 (s), | |
2076 | gimple_assign_rhs2 (s), | |
2077 | code2, op2a, op2b))) | |
2078 | { | |
2079 | /* Handle the OR case, where we are reassociating: | |
2080 | (inner1 OR inner2) OR (op2a code2 op2b) | |
8236c8eb JJ |
2081 | => (inner1 OR t) |
2082 | => (t OR partial) */ | |
2083 | if (is_or) | |
e89065a1 SL |
2084 | { |
2085 | if (integer_zerop (t)) | |
2086 | return inner1; | |
2087 | else if (integer_onep (t)) | |
2088 | return boolean_true_node; | |
8236c8eb JJ |
2089 | /* If both are the same, we can apply the identity |
2090 | (x OR x) == x. */ | |
2091 | else if (partial && same_bool_result_p (t, partial)) | |
2092 | return t; | |
e89065a1 SL |
2093 | } |
2094 | ||
2095 | /* Handle the AND case, where we are redistributing: | |
2096 | (inner1 AND inner2) OR (op2a code2 op2b) | |
2097 | => (t AND (inner1 OR (op2a code2 op2b))) | |
2098 | => (t AND partial) */ | |
2099 | else | |
2100 | { | |
2101 | if (integer_zerop (t)) | |
2102 | return boolean_false_node; | |
2103 | else if (partial) | |
2104 | { | |
2105 | /* We already got a simplification for the other | |
2106 | operand to the redistributed AND expression. The | |
2107 | interesting case is when at least one is true. | |
2108 | Or, if both are the same, we can apply the identity | |
8236c8eb | 2109 | (x AND x) == x. */ |
e89065a1 SL |
2110 | if (integer_onep (partial)) |
2111 | return t; | |
2112 | else if (integer_onep (t)) | |
2113 | return partial; | |
2114 | else if (same_bool_result_p (t, partial)) | |
8236c8eb | 2115 | return t; |
e89065a1 SL |
2116 | } |
2117 | } | |
2118 | } | |
2119 | } | |
2120 | return NULL_TREE; | |
2121 | } | |
2122 | ||
2123 | /* Try to simplify the OR of two comparisons defined by | |
2124 | (OP1A CODE1 OP1B) and (OP2A CODE2 OP2B), respectively. | |
2125 | If this can be done without constructing an intermediate value, | |
2126 | return the resulting tree; otherwise NULL_TREE is returned. | |
2127 | This function is deliberately asymmetric as it recurses on SSA_DEFs | |
2128 | in the first comparison but not the second. */ | |
2129 | ||
2130 | static tree | |
2131 | or_comparisons_1 (enum tree_code code1, tree op1a, tree op1b, | |
2132 | enum tree_code code2, tree op2a, tree op2b) | |
2133 | { | |
2134 | /* First check for ((x CODE1 y) OR (x CODE2 y)). */ | |
2135 | if (operand_equal_p (op1a, op2a, 0) | |
2136 | && operand_equal_p (op1b, op2b, 0)) | |
2137 | { | |
eb9820c0 | 2138 | /* Result will be either NULL_TREE, or a combined comparison. */ |
e89065a1 SL |
2139 | tree t = combine_comparisons (UNKNOWN_LOCATION, |
2140 | TRUTH_ORIF_EXPR, code1, code2, | |
2141 | boolean_type_node, op1a, op1b); | |
2142 | if (t) | |
2143 | return t; | |
2144 | } | |
2145 | ||
2146 | /* Likewise the swapped case of the above. */ | |
2147 | if (operand_equal_p (op1a, op2b, 0) | |
2148 | && operand_equal_p (op1b, op2a, 0)) | |
2149 | { | |
eb9820c0 | 2150 | /* Result will be either NULL_TREE, or a combined comparison. */ |
e89065a1 SL |
2151 | tree t = combine_comparisons (UNKNOWN_LOCATION, |
2152 | TRUTH_ORIF_EXPR, code1, | |
2153 | swap_tree_comparison (code2), | |
2154 | boolean_type_node, op1a, op1b); | |
2155 | if (t) | |
2156 | return t; | |
2157 | } | |
2158 | ||
2159 | /* If both comparisons are of the same value against constants, we might | |
2160 | be able to merge them. */ | |
2161 | if (operand_equal_p (op1a, op2a, 0) | |
2162 | && TREE_CODE (op1b) == INTEGER_CST | |
2163 | && TREE_CODE (op2b) == INTEGER_CST) | |
2164 | { | |
2165 | int cmp = tree_int_cst_compare (op1b, op2b); | |
2166 | ||
2167 | /* If we have (op1a != op1b), we should either be able to | |
2168 | return that or TRUE, depending on whether the constant op1b | |
2169 | also satisfies the other comparison against op2b. */ | |
2170 | if (code1 == NE_EXPR) | |
2171 | { | |
2172 | bool done = true; | |
2173 | bool val; | |
2174 | switch (code2) | |
2175 | { | |
2176 | case EQ_EXPR: val = (cmp == 0); break; | |
2177 | case NE_EXPR: val = (cmp != 0); break; | |
2178 | case LT_EXPR: val = (cmp < 0); break; | |
2179 | case GT_EXPR: val = (cmp > 0); break; | |
2180 | case LE_EXPR: val = (cmp <= 0); break; | |
2181 | case GE_EXPR: val = (cmp >= 0); break; | |
2182 | default: done = false; | |
2183 | } | |
2184 | if (done) | |
2185 | { | |
2186 | if (val) | |
2187 | return boolean_true_node; | |
2188 | else | |
2189 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2190 | } | |
2191 | } | |
2192 | /* Likewise if the second comparison is a != comparison. */ | |
2193 | else if (code2 == NE_EXPR) | |
2194 | { | |
2195 | bool done = true; | |
2196 | bool val; | |
2197 | switch (code1) | |
2198 | { | |
2199 | case EQ_EXPR: val = (cmp == 0); break; | |
2200 | case NE_EXPR: val = (cmp != 0); break; | |
2201 | case LT_EXPR: val = (cmp > 0); break; | |
2202 | case GT_EXPR: val = (cmp < 0); break; | |
2203 | case LE_EXPR: val = (cmp >= 0); break; | |
2204 | case GE_EXPR: val = (cmp <= 0); break; | |
2205 | default: done = false; | |
2206 | } | |
2207 | if (done) | |
2208 | { | |
2209 | if (val) | |
2210 | return boolean_true_node; | |
2211 | else | |
2212 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2213 | } | |
2214 | } | |
2215 | ||
2216 | /* See if an equality test is redundant with the other comparison. */ | |
2217 | else if (code1 == EQ_EXPR) | |
2218 | { | |
2219 | bool val; | |
2220 | switch (code2) | |
2221 | { | |
2222 | case EQ_EXPR: val = (cmp == 0); break; | |
2223 | case NE_EXPR: val = (cmp != 0); break; | |
2224 | case LT_EXPR: val = (cmp < 0); break; | |
2225 | case GT_EXPR: val = (cmp > 0); break; | |
2226 | case LE_EXPR: val = (cmp <= 0); break; | |
2227 | case GE_EXPR: val = (cmp >= 0); break; | |
2228 | default: | |
2229 | val = false; | |
2230 | } | |
2231 | if (val) | |
2232 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2233 | } | |
2234 | else if (code2 == EQ_EXPR) | |
2235 | { | |
2236 | bool val; | |
2237 | switch (code1) | |
2238 | { | |
2239 | case EQ_EXPR: val = (cmp == 0); break; | |
2240 | case NE_EXPR: val = (cmp != 0); break; | |
2241 | case LT_EXPR: val = (cmp > 0); break; | |
2242 | case GT_EXPR: val = (cmp < 0); break; | |
2243 | case LE_EXPR: val = (cmp >= 0); break; | |
2244 | case GE_EXPR: val = (cmp <= 0); break; | |
2245 | default: | |
2246 | val = false; | |
2247 | } | |
2248 | if (val) | |
2249 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2250 | } | |
2251 | ||
2252 | /* Chose the less restrictive of two < or <= comparisons. */ | |
2253 | else if ((code1 == LT_EXPR || code1 == LE_EXPR) | |
2254 | && (code2 == LT_EXPR || code2 == LE_EXPR)) | |
2255 | { | |
2256 | if ((cmp < 0) || (cmp == 0 && code1 == LT_EXPR)) | |
2257 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2258 | else | |
2259 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2260 | } | |
2261 | ||
2262 | /* Likewise chose the less restrictive of two > or >= comparisons. */ | |
2263 | else if ((code1 == GT_EXPR || code1 == GE_EXPR) | |
2264 | && (code2 == GT_EXPR || code2 == GE_EXPR)) | |
2265 | { | |
2266 | if ((cmp > 0) || (cmp == 0 && code1 == GT_EXPR)) | |
2267 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2268 | else | |
2269 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2270 | } | |
2271 | ||
2272 | /* Check for singleton ranges. */ | |
2273 | else if (cmp == 0 | |
2274 | && ((code1 == LT_EXPR && code2 == GT_EXPR) | |
2275 | || (code1 == GT_EXPR && code2 == LT_EXPR))) | |
2276 | return fold_build2 (NE_EXPR, boolean_type_node, op1a, op2b); | |
2277 | ||
2278 | /* Check for less/greater pairs that don't restrict the range at all. */ | |
2279 | else if (cmp >= 0 | |
2280 | && (code1 == LT_EXPR || code1 == LE_EXPR) | |
2281 | && (code2 == GT_EXPR || code2 == GE_EXPR)) | |
2282 | return boolean_true_node; | |
2283 | else if (cmp <= 0 | |
2284 | && (code1 == GT_EXPR || code1 == GE_EXPR) | |
2285 | && (code2 == LT_EXPR || code2 == LE_EXPR)) | |
2286 | return boolean_true_node; | |
2287 | } | |
2288 | ||
2289 | /* Perhaps the first comparison is (NAME != 0) or (NAME == 1) where | |
2290 | NAME's definition is a truth value. See if there are any simplifications | |
2291 | that can be done against the NAME's definition. */ | |
2292 | if (TREE_CODE (op1a) == SSA_NAME | |
2293 | && (code1 == NE_EXPR || code1 == EQ_EXPR) | |
2294 | && (integer_zerop (op1b) || integer_onep (op1b))) | |
2295 | { | |
2296 | bool invert = ((code1 == EQ_EXPR && integer_zerop (op1b)) | |
2297 | || (code1 == NE_EXPR && integer_onep (op1b))); | |
2298 | gimple stmt = SSA_NAME_DEF_STMT (op1a); | |
2299 | switch (gimple_code (stmt)) | |
2300 | { | |
2301 | case GIMPLE_ASSIGN: | |
2302 | /* Try to simplify by copy-propagating the definition. */ | |
2303 | return or_var_with_comparison (op1a, invert, code2, op2a, op2b); | |
2304 | ||
2305 | case GIMPLE_PHI: | |
2306 | /* If every argument to the PHI produces the same result when | |
2307 | ORed with the second comparison, we win. | |
2308 | Do not do this unless the type is bool since we need a bool | |
2309 | result here anyway. */ | |
2310 | if (TREE_CODE (TREE_TYPE (op1a)) == BOOLEAN_TYPE) | |
2311 | { | |
2312 | tree result = NULL_TREE; | |
2313 | unsigned i; | |
2314 | for (i = 0; i < gimple_phi_num_args (stmt); i++) | |
2315 | { | |
2316 | tree arg = gimple_phi_arg_def (stmt, i); | |
2317 | ||
2318 | /* If this PHI has itself as an argument, ignore it. | |
2319 | If all the other args produce the same result, | |
2320 | we're still OK. */ | |
2321 | if (arg == gimple_phi_result (stmt)) | |
2322 | continue; | |
2323 | else if (TREE_CODE (arg) == INTEGER_CST) | |
2324 | { | |
2325 | if (invert ? integer_zerop (arg) : integer_nonzerop (arg)) | |
2326 | { | |
2327 | if (!result) | |
2328 | result = boolean_true_node; | |
2329 | else if (!integer_onep (result)) | |
2330 | return NULL_TREE; | |
2331 | } | |
2332 | else if (!result) | |
2333 | result = fold_build2 (code2, boolean_type_node, | |
2334 | op2a, op2b); | |
2335 | else if (!same_bool_comparison_p (result, | |
2336 | code2, op2a, op2b)) | |
2337 | return NULL_TREE; | |
2338 | } | |
0e8b84ec JJ |
2339 | else if (TREE_CODE (arg) == SSA_NAME |
2340 | && !SSA_NAME_IS_DEFAULT_DEF (arg)) | |
e89065a1 | 2341 | { |
6c66f733 JJ |
2342 | tree temp; |
2343 | gimple def_stmt = SSA_NAME_DEF_STMT (arg); | |
2344 | /* In simple cases we can look through PHI nodes, | |
2345 | but we have to be careful with loops. | |
2346 | See PR49073. */ | |
2347 | if (! dom_info_available_p (CDI_DOMINATORS) | |
2348 | || gimple_bb (def_stmt) == gimple_bb (stmt) | |
2349 | || dominated_by_p (CDI_DOMINATORS, | |
2350 | gimple_bb (def_stmt), | |
2351 | gimple_bb (stmt))) | |
2352 | return NULL_TREE; | |
2353 | temp = or_var_with_comparison (arg, invert, code2, | |
2354 | op2a, op2b); | |
e89065a1 SL |
2355 | if (!temp) |
2356 | return NULL_TREE; | |
2357 | else if (!result) | |
2358 | result = temp; | |
2359 | else if (!same_bool_result_p (result, temp)) | |
2360 | return NULL_TREE; | |
2361 | } | |
2362 | else | |
2363 | return NULL_TREE; | |
2364 | } | |
2365 | return result; | |
2366 | } | |
2367 | ||
2368 | default: | |
2369 | break; | |
2370 | } | |
2371 | } | |
2372 | return NULL_TREE; | |
2373 | } | |
2374 | ||
2375 | /* Try to simplify the OR of two comparisons, specified by | |
2376 | (OP1A CODE1 OP1B) and (OP2B CODE2 OP2B), respectively. | |
2377 | If this can be simplified to a single expression (without requiring | |
2378 | introducing more SSA variables to hold intermediate values), | |
2379 | return the resulting tree. Otherwise return NULL_TREE. | |
2380 | If the result expression is non-null, it has boolean type. */ | |
2381 | ||
2382 | tree | |
2383 | maybe_fold_or_comparisons (enum tree_code code1, tree op1a, tree op1b, | |
2384 | enum tree_code code2, tree op2a, tree op2b) | |
2385 | { | |
2386 | tree t = or_comparisons_1 (code1, op1a, op1b, code2, op2a, op2b); | |
2387 | if (t) | |
2388 | return t; | |
2389 | else | |
2390 | return or_comparisons_1 (code2, op2a, op2b, code1, op1a, op1b); | |
2391 | } | |
cfef45c8 RG |
2392 | |
2393 | ||
2394 | /* Fold STMT to a constant using VALUEIZE to valueize SSA names. | |
2395 | ||
2396 | Either NULL_TREE, a simplified but non-constant or a constant | |
2397 | is returned. | |
2398 | ||
2399 | ??? This should go into a gimple-fold-inline.h file to be eventually | |
2400 | privatized with the single valueize function used in the various TUs | |
2401 | to avoid the indirect function call overhead. */ | |
2402 | ||
2403 | tree | |
2404 | gimple_fold_stmt_to_constant_1 (gimple stmt, tree (*valueize) (tree)) | |
2405 | { | |
2406 | location_t loc = gimple_location (stmt); | |
2407 | switch (gimple_code (stmt)) | |
2408 | { | |
2409 | case GIMPLE_ASSIGN: | |
2410 | { | |
2411 | enum tree_code subcode = gimple_assign_rhs_code (stmt); | |
2412 | ||
2413 | switch (get_gimple_rhs_class (subcode)) | |
2414 | { | |
2415 | case GIMPLE_SINGLE_RHS: | |
2416 | { | |
2417 | tree rhs = gimple_assign_rhs1 (stmt); | |
2418 | enum tree_code_class kind = TREE_CODE_CLASS (subcode); | |
2419 | ||
2420 | if (TREE_CODE (rhs) == SSA_NAME) | |
2421 | { | |
2422 | /* If the RHS is an SSA_NAME, return its known constant value, | |
2423 | if any. */ | |
2424 | return (*valueize) (rhs); | |
2425 | } | |
2426 | /* Handle propagating invariant addresses into address | |
2427 | operations. */ | |
2428 | else if (TREE_CODE (rhs) == ADDR_EXPR | |
2429 | && !is_gimple_min_invariant (rhs)) | |
2430 | { | |
d25c4172 | 2431 | HOST_WIDE_INT offset = 0; |
cfef45c8 RG |
2432 | tree base; |
2433 | base = get_addr_base_and_unit_offset_1 (TREE_OPERAND (rhs, 0), | |
2434 | &offset, | |
2435 | valueize); | |
2436 | if (base | |
2437 | && (CONSTANT_CLASS_P (base) | |
2438 | || decl_address_invariant_p (base))) | |
2439 | return build_invariant_address (TREE_TYPE (rhs), | |
2440 | base, offset); | |
2441 | } | |
2442 | else if (TREE_CODE (rhs) == CONSTRUCTOR | |
2443 | && TREE_CODE (TREE_TYPE (rhs)) == VECTOR_TYPE | |
2444 | && (CONSTRUCTOR_NELTS (rhs) | |
2445 | == TYPE_VECTOR_SUBPARTS (TREE_TYPE (rhs)))) | |
2446 | { | |
2447 | unsigned i; | |
d2a12ae7 | 2448 | tree val, *vec; |
cfef45c8 | 2449 | |
d2a12ae7 RG |
2450 | vec = XALLOCAVEC (tree, |
2451 | TYPE_VECTOR_SUBPARTS (TREE_TYPE (rhs))); | |
cfef45c8 RG |
2452 | FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (rhs), i, val) |
2453 | { | |
2454 | val = (*valueize) (val); | |
2455 | if (TREE_CODE (val) == INTEGER_CST | |
2456 | || TREE_CODE (val) == REAL_CST | |
2457 | || TREE_CODE (val) == FIXED_CST) | |
d2a12ae7 | 2458 | vec[i] = val; |
cfef45c8 RG |
2459 | else |
2460 | return NULL_TREE; | |
2461 | } | |
2462 | ||
d2a12ae7 | 2463 | return build_vector (TREE_TYPE (rhs), vec); |
cfef45c8 RG |
2464 | } |
2465 | ||
2466 | if (kind == tcc_reference) | |
2467 | { | |
2468 | if ((TREE_CODE (rhs) == VIEW_CONVERT_EXPR | |
2469 | || TREE_CODE (rhs) == REALPART_EXPR | |
2470 | || TREE_CODE (rhs) == IMAGPART_EXPR) | |
2471 | && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME) | |
2472 | { | |
2473 | tree val = (*valueize) (TREE_OPERAND (rhs, 0)); | |
2474 | return fold_unary_loc (EXPR_LOCATION (rhs), | |
2475 | TREE_CODE (rhs), | |
2476 | TREE_TYPE (rhs), val); | |
2477 | } | |
2478 | else if (TREE_CODE (rhs) == BIT_FIELD_REF | |
2479 | && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME) | |
2480 | { | |
2481 | tree val = (*valueize) (TREE_OPERAND (rhs, 0)); | |
2482 | return fold_ternary_loc (EXPR_LOCATION (rhs), | |
2483 | TREE_CODE (rhs), | |
2484 | TREE_TYPE (rhs), val, | |
2485 | TREE_OPERAND (rhs, 1), | |
2486 | TREE_OPERAND (rhs, 2)); | |
2487 | } | |
2488 | else if (TREE_CODE (rhs) == MEM_REF | |
2489 | && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME) | |
2490 | { | |
2491 | tree val = (*valueize) (TREE_OPERAND (rhs, 0)); | |
2492 | if (TREE_CODE (val) == ADDR_EXPR | |
2493 | && is_gimple_min_invariant (val)) | |
2494 | { | |
2495 | tree tem = fold_build2 (MEM_REF, TREE_TYPE (rhs), | |
2496 | unshare_expr (val), | |
2497 | TREE_OPERAND (rhs, 1)); | |
2498 | if (tem) | |
2499 | rhs = tem; | |
2500 | } | |
2501 | } | |
2502 | return fold_const_aggregate_ref_1 (rhs, valueize); | |
2503 | } | |
2504 | else if (kind == tcc_declaration) | |
2505 | return get_symbol_constant_value (rhs); | |
2506 | return rhs; | |
2507 | } | |
2508 | ||
2509 | case GIMPLE_UNARY_RHS: | |
2510 | { | |
2511 | /* Handle unary operators that can appear in GIMPLE form. | |
2512 | Note that we know the single operand must be a constant, | |
2513 | so this should almost always return a simplified RHS. */ | |
315f5f1b | 2514 | tree lhs = gimple_assign_lhs (stmt); |
cfef45c8 RG |
2515 | tree op0 = (*valueize) (gimple_assign_rhs1 (stmt)); |
2516 | ||
2517 | /* Conversions are useless for CCP purposes if they are | |
2518 | value-preserving. Thus the restrictions that | |
315f5f1b RG |
2519 | useless_type_conversion_p places for restrict qualification |
2520 | of pointer types should not apply here. | |
2521 | Substitution later will only substitute to allowed places. */ | |
cfef45c8 RG |
2522 | if (CONVERT_EXPR_CODE_P (subcode) |
2523 | && POINTER_TYPE_P (TREE_TYPE (lhs)) | |
315f5f1b | 2524 | && POINTER_TYPE_P (TREE_TYPE (op0)) |
8f420307 EB |
2525 | && TYPE_ADDR_SPACE (TREE_TYPE (lhs)) |
2526 | == TYPE_ADDR_SPACE (TREE_TYPE (op0)) | |
2527 | && TYPE_MODE (TREE_TYPE (lhs)) | |
2528 | == TYPE_MODE (TREE_TYPE (op0))) | |
315f5f1b | 2529 | return op0; |
cfef45c8 RG |
2530 | |
2531 | return | |
2532 | fold_unary_ignore_overflow_loc (loc, subcode, | |
2533 | gimple_expr_type (stmt), op0); | |
2534 | } | |
2535 | ||
2536 | case GIMPLE_BINARY_RHS: | |
2537 | { | |
2538 | /* Handle binary operators that can appear in GIMPLE form. */ | |
2539 | tree op0 = (*valueize) (gimple_assign_rhs1 (stmt)); | |
2540 | tree op1 = (*valueize) (gimple_assign_rhs2 (stmt)); | |
2541 | ||
2542 | /* Translate &x + CST into an invariant form suitable for | |
2543 | further propagation. */ | |
2544 | if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR | |
2545 | && TREE_CODE (op0) == ADDR_EXPR | |
2546 | && TREE_CODE (op1) == INTEGER_CST) | |
2547 | { | |
2548 | tree off = fold_convert (ptr_type_node, op1); | |
4d59a001 RG |
2549 | return build_fold_addr_expr_loc |
2550 | (loc, | |
2551 | fold_build2 (MEM_REF, | |
cfef45c8 RG |
2552 | TREE_TYPE (TREE_TYPE (op0)), |
2553 | unshare_expr (op0), off)); | |
2554 | } | |
2555 | ||
2556 | return fold_binary_loc (loc, subcode, | |
2557 | gimple_expr_type (stmt), op0, op1); | |
2558 | } | |
2559 | ||
2560 | case GIMPLE_TERNARY_RHS: | |
2561 | { | |
2562 | /* Handle ternary operators that can appear in GIMPLE form. */ | |
2563 | tree op0 = (*valueize) (gimple_assign_rhs1 (stmt)); | |
2564 | tree op1 = (*valueize) (gimple_assign_rhs2 (stmt)); | |
2565 | tree op2 = (*valueize) (gimple_assign_rhs3 (stmt)); | |
2566 | ||
d3878abf RG |
2567 | /* Fold embedded expressions in ternary codes. */ |
2568 | if ((subcode == COND_EXPR | |
2569 | || subcode == VEC_COND_EXPR) | |
2570 | && COMPARISON_CLASS_P (op0)) | |
2571 | { | |
2572 | tree op00 = (*valueize) (TREE_OPERAND (op0, 0)); | |
2573 | tree op01 = (*valueize) (TREE_OPERAND (op0, 1)); | |
2574 | tree tem = fold_binary_loc (loc, TREE_CODE (op0), | |
2575 | TREE_TYPE (op0), op00, op01); | |
2576 | if (tem) | |
2577 | op0 = tem; | |
2578 | } | |
2579 | ||
cfef45c8 RG |
2580 | return fold_ternary_loc (loc, subcode, |
2581 | gimple_expr_type (stmt), op0, op1, op2); | |
2582 | } | |
2583 | ||
2584 | default: | |
2585 | gcc_unreachable (); | |
2586 | } | |
2587 | } | |
2588 | ||
2589 | case GIMPLE_CALL: | |
2590 | { | |
25583c4f RS |
2591 | tree fn; |
2592 | ||
2593 | if (gimple_call_internal_p (stmt)) | |
2594 | /* No folding yet for these functions. */ | |
2595 | return NULL_TREE; | |
2596 | ||
2597 | fn = (*valueize) (gimple_call_fn (stmt)); | |
cfef45c8 RG |
2598 | if (TREE_CODE (fn) == ADDR_EXPR |
2599 | && TREE_CODE (TREE_OPERAND (fn, 0)) == FUNCTION_DECL | |
2600 | && DECL_BUILT_IN (TREE_OPERAND (fn, 0))) | |
2601 | { | |
2602 | tree *args = XALLOCAVEC (tree, gimple_call_num_args (stmt)); | |
2603 | tree call, retval; | |
2604 | unsigned i; | |
2605 | for (i = 0; i < gimple_call_num_args (stmt); ++i) | |
2606 | args[i] = (*valueize) (gimple_call_arg (stmt, i)); | |
2607 | call = build_call_array_loc (loc, | |
2608 | gimple_call_return_type (stmt), | |
2609 | fn, gimple_call_num_args (stmt), args); | |
2610 | retval = fold_call_expr (EXPR_LOCATION (call), call, false); | |
2611 | if (retval) | |
2612 | /* fold_call_expr wraps the result inside a NOP_EXPR. */ | |
2613 | STRIP_NOPS (retval); | |
2614 | return retval; | |
2615 | } | |
2616 | return NULL_TREE; | |
2617 | } | |
2618 | ||
2619 | default: | |
2620 | return NULL_TREE; | |
2621 | } | |
2622 | } | |
2623 | ||
2624 | /* Fold STMT to a constant using VALUEIZE to valueize SSA names. | |
2625 | Returns NULL_TREE if folding to a constant is not possible, otherwise | |
2626 | returns a constant according to is_gimple_min_invariant. */ | |
2627 | ||
2628 | tree | |
2629 | gimple_fold_stmt_to_constant (gimple stmt, tree (*valueize) (tree)) | |
2630 | { | |
2631 | tree res = gimple_fold_stmt_to_constant_1 (stmt, valueize); | |
2632 | if (res && is_gimple_min_invariant (res)) | |
2633 | return res; | |
2634 | return NULL_TREE; | |
2635 | } | |
2636 | ||
2637 | ||
2638 | /* The following set of functions are supposed to fold references using | |
2639 | their constant initializers. */ | |
2640 | ||
2641 | static tree fold_ctor_reference (tree type, tree ctor, | |
2642 | unsigned HOST_WIDE_INT offset, | |
2643 | unsigned HOST_WIDE_INT size); | |
2644 | ||
2645 | /* See if we can find constructor defining value of BASE. | |
2646 | When we know the consructor with constant offset (such as | |
2647 | base is array[40] and we do know constructor of array), then | |
2648 | BIT_OFFSET is adjusted accordingly. | |
2649 | ||
2650 | As a special case, return error_mark_node when constructor | |
2651 | is not explicitly available, but it is known to be zero | |
2652 | such as 'static const int a;'. */ | |
2653 | static tree | |
2654 | get_base_constructor (tree base, HOST_WIDE_INT *bit_offset, | |
2655 | tree (*valueize)(tree)) | |
2656 | { | |
2657 | HOST_WIDE_INT bit_offset2, size, max_size; | |
2658 | if (TREE_CODE (base) == MEM_REF) | |
2659 | { | |
2660 | if (!integer_zerop (TREE_OPERAND (base, 1))) | |
2661 | { | |
2662 | if (!host_integerp (TREE_OPERAND (base, 1), 0)) | |
2663 | return NULL_TREE; | |
2664 | *bit_offset += (mem_ref_offset (base).low | |
2665 | * BITS_PER_UNIT); | |
2666 | } | |
2667 | ||
2668 | if (valueize | |
2669 | && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME) | |
2670 | base = valueize (TREE_OPERAND (base, 0)); | |
2671 | if (!base || TREE_CODE (base) != ADDR_EXPR) | |
2672 | return NULL_TREE; | |
2673 | base = TREE_OPERAND (base, 0); | |
2674 | } | |
2675 | ||
2676 | /* Get a CONSTRUCTOR. If BASE is a VAR_DECL, get its | |
2677 | DECL_INITIAL. If BASE is a nested reference into another | |
2678 | ARRAY_REF or COMPONENT_REF, make a recursive call to resolve | |
2679 | the inner reference. */ | |
2680 | switch (TREE_CODE (base)) | |
2681 | { | |
2682 | case VAR_DECL: | |
2683 | if (!const_value_known_p (base)) | |
2684 | return NULL_TREE; | |
2685 | ||
2686 | /* Fallthru. */ | |
2687 | case CONST_DECL: | |
2688 | if (!DECL_INITIAL (base) | |
2689 | && (TREE_STATIC (base) || DECL_EXTERNAL (base))) | |
2690 | return error_mark_node; | |
2691 | return DECL_INITIAL (base); | |
2692 | ||
2693 | case ARRAY_REF: | |
2694 | case COMPONENT_REF: | |
2695 | base = get_ref_base_and_extent (base, &bit_offset2, &size, &max_size); | |
2696 | if (max_size == -1 || size != max_size) | |
2697 | return NULL_TREE; | |
2698 | *bit_offset += bit_offset2; | |
2699 | return get_base_constructor (base, bit_offset, valueize); | |
2700 | ||
2701 | case STRING_CST: | |
2702 | case CONSTRUCTOR: | |
2703 | return base; | |
2704 | ||
2705 | default: | |
2706 | return NULL_TREE; | |
2707 | } | |
2708 | } | |
2709 | ||
2710 | /* CTOR is STRING_CST. Fold reference of type TYPE and size SIZE | |
2711 | to the memory at bit OFFSET. | |
2712 | ||
2713 | We do only simple job of folding byte accesses. */ | |
2714 | ||
2715 | static tree | |
2716 | fold_string_cst_ctor_reference (tree type, tree ctor, | |
2717 | unsigned HOST_WIDE_INT offset, | |
2718 | unsigned HOST_WIDE_INT size) | |
2719 | { | |
2720 | if (INTEGRAL_TYPE_P (type) | |
2721 | && (TYPE_MODE (type) | |
2722 | == TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) | |
2723 | && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) | |
2724 | == MODE_INT) | |
2725 | && GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) == 1 | |
2726 | && size == BITS_PER_UNIT | |
2727 | && !(offset % BITS_PER_UNIT)) | |
2728 | { | |
2729 | offset /= BITS_PER_UNIT; | |
2730 | if (offset < (unsigned HOST_WIDE_INT) TREE_STRING_LENGTH (ctor)) | |
2731 | return build_int_cst_type (type, (TREE_STRING_POINTER (ctor) | |
2732 | [offset])); | |
2733 | /* Folding | |
2734 | const char a[20]="hello"; | |
2735 | return a[10]; | |
2736 | ||
2737 | might lead to offset greater than string length. In this case we | |
2738 | know value is either initialized to 0 or out of bounds. Return 0 | |
2739 | in both cases. */ | |
2740 | return build_zero_cst (type); | |
2741 | } | |
2742 | return NULL_TREE; | |
2743 | } | |
2744 | ||
2745 | /* CTOR is CONSTRUCTOR of an array type. Fold reference of type TYPE and size | |
2746 | SIZE to the memory at bit OFFSET. */ | |
2747 | ||
2748 | static tree | |
2749 | fold_array_ctor_reference (tree type, tree ctor, | |
2750 | unsigned HOST_WIDE_INT offset, | |
2751 | unsigned HOST_WIDE_INT size) | |
2752 | { | |
2753 | unsigned HOST_WIDE_INT cnt; | |
2754 | tree cfield, cval; | |
2755 | double_int low_bound, elt_size; | |
2756 | double_int index, max_index; | |
2757 | double_int access_index; | |
eb8f1123 | 2758 | tree domain_type = NULL_TREE; |
cfef45c8 RG |
2759 | HOST_WIDE_INT inner_offset; |
2760 | ||
2761 | /* Compute low bound and elt size. */ | |
eb8f1123 RG |
2762 | if (TREE_CODE (TREE_TYPE (ctor)) == ARRAY_TYPE) |
2763 | domain_type = TYPE_DOMAIN (TREE_TYPE (ctor)); | |
cfef45c8 RG |
2764 | if (domain_type && TYPE_MIN_VALUE (domain_type)) |
2765 | { | |
2766 | /* Static constructors for variably sized objects makes no sense. */ | |
2767 | gcc_assert (TREE_CODE (TYPE_MIN_VALUE (domain_type)) == INTEGER_CST); | |
2768 | low_bound = tree_to_double_int (TYPE_MIN_VALUE (domain_type)); | |
2769 | } | |
2770 | else | |
2771 | low_bound = double_int_zero; | |
2772 | /* Static constructors for variably sized objects makes no sense. */ | |
2773 | gcc_assert (TREE_CODE(TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (ctor)))) | |
2774 | == INTEGER_CST); | |
2775 | elt_size = | |
2776 | tree_to_double_int (TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (ctor)))); | |
2777 | ||
2778 | ||
2779 | /* We can handle only constantly sized accesses that are known to not | |
2780 | be larger than size of array element. */ | |
2781 | if (!TYPE_SIZE_UNIT (type) | |
2782 | || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST | |
2783 | || double_int_cmp (elt_size, | |
2784 | tree_to_double_int (TYPE_SIZE_UNIT (type)), 0) < 0) | |
2785 | return NULL_TREE; | |
2786 | ||
2787 | /* Compute the array index we look for. */ | |
2788 | access_index = double_int_udiv (uhwi_to_double_int (offset / BITS_PER_UNIT), | |
2789 | elt_size, TRUNC_DIV_EXPR); | |
2790 | access_index = double_int_add (access_index, low_bound); | |
2791 | ||
2792 | /* And offset within the access. */ | |
2793 | inner_offset = offset % (double_int_to_uhwi (elt_size) * BITS_PER_UNIT); | |
2794 | ||
2795 | /* See if the array field is large enough to span whole access. We do not | |
2796 | care to fold accesses spanning multiple array indexes. */ | |
2797 | if (inner_offset + size > double_int_to_uhwi (elt_size) * BITS_PER_UNIT) | |
2798 | return NULL_TREE; | |
2799 | ||
2800 | index = double_int_sub (low_bound, double_int_one); | |
2801 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, cval) | |
2802 | { | |
2803 | /* Array constructor might explicitely set index, or specify range | |
2804 | or leave index NULL meaning that it is next index after previous | |
2805 | one. */ | |
2806 | if (cfield) | |
2807 | { | |
2808 | if (TREE_CODE (cfield) == INTEGER_CST) | |
2809 | max_index = index = tree_to_double_int (cfield); | |
2810 | else | |
2811 | { | |
2812 | gcc_assert (TREE_CODE (cfield) == RANGE_EXPR); | |
2813 | index = tree_to_double_int (TREE_OPERAND (cfield, 0)); | |
2814 | max_index = tree_to_double_int (TREE_OPERAND (cfield, 1)); | |
2815 | } | |
2816 | } | |
2817 | else | |
2818 | max_index = index = double_int_add (index, double_int_one); | |
2819 | ||
2820 | /* Do we have match? */ | |
2821 | if (double_int_cmp (access_index, index, 1) >= 0 | |
2822 | && double_int_cmp (access_index, max_index, 1) <= 0) | |
2823 | return fold_ctor_reference (type, cval, inner_offset, size); | |
2824 | } | |
2825 | /* When memory is not explicitely mentioned in constructor, | |
2826 | it is 0 (or out of range). */ | |
2827 | return build_zero_cst (type); | |
2828 | } | |
2829 | ||
2830 | /* CTOR is CONSTRUCTOR of an aggregate or vector. | |
2831 | Fold reference of type TYPE and size SIZE to the memory at bit OFFSET. */ | |
2832 | ||
2833 | static tree | |
2834 | fold_nonarray_ctor_reference (tree type, tree ctor, | |
2835 | unsigned HOST_WIDE_INT offset, | |
2836 | unsigned HOST_WIDE_INT size) | |
2837 | { | |
2838 | unsigned HOST_WIDE_INT cnt; | |
2839 | tree cfield, cval; | |
2840 | ||
2841 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, | |
2842 | cval) | |
2843 | { | |
2844 | tree byte_offset = DECL_FIELD_OFFSET (cfield); | |
2845 | tree field_offset = DECL_FIELD_BIT_OFFSET (cfield); | |
2846 | tree field_size = DECL_SIZE (cfield); | |
2847 | double_int bitoffset; | |
2848 | double_int byte_offset_cst = tree_to_double_int (byte_offset); | |
2849 | double_int bits_per_unit_cst = uhwi_to_double_int (BITS_PER_UNIT); | |
b8b2b009 | 2850 | double_int bitoffset_end, access_end; |
cfef45c8 RG |
2851 | |
2852 | /* Variable sized objects in static constructors makes no sense, | |
2853 | but field_size can be NULL for flexible array members. */ | |
2854 | gcc_assert (TREE_CODE (field_offset) == INTEGER_CST | |
2855 | && TREE_CODE (byte_offset) == INTEGER_CST | |
2856 | && (field_size != NULL_TREE | |
2857 | ? TREE_CODE (field_size) == INTEGER_CST | |
2858 | : TREE_CODE (TREE_TYPE (cfield)) == ARRAY_TYPE)); | |
2859 | ||
2860 | /* Compute bit offset of the field. */ | |
2861 | bitoffset = double_int_add (tree_to_double_int (field_offset), | |
2862 | double_int_mul (byte_offset_cst, | |
2863 | bits_per_unit_cst)); | |
2864 | /* Compute bit offset where the field ends. */ | |
2865 | if (field_size != NULL_TREE) | |
2866 | bitoffset_end = double_int_add (bitoffset, | |
2867 | tree_to_double_int (field_size)); | |
2868 | else | |
2869 | bitoffset_end = double_int_zero; | |
2870 | ||
b8b2b009 JJ |
2871 | access_end = double_int_add (uhwi_to_double_int (offset), |
2872 | uhwi_to_double_int (size)); | |
2873 | ||
2874 | /* Is there any overlap between [OFFSET, OFFSET+SIZE) and | |
2875 | [BITOFFSET, BITOFFSET_END)? */ | |
2876 | if (double_int_cmp (access_end, bitoffset, 0) > 0 | |
cfef45c8 RG |
2877 | && (field_size == NULL_TREE |
2878 | || double_int_cmp (uhwi_to_double_int (offset), | |
2879 | bitoffset_end, 0) < 0)) | |
2880 | { | |
cfef45c8 RG |
2881 | double_int inner_offset = double_int_sub (uhwi_to_double_int (offset), |
2882 | bitoffset); | |
2883 | /* We do have overlap. Now see if field is large enough to | |
2884 | cover the access. Give up for accesses spanning multiple | |
2885 | fields. */ | |
2886 | if (double_int_cmp (access_end, bitoffset_end, 0) > 0) | |
2887 | return NULL_TREE; | |
b8b2b009 JJ |
2888 | if (double_int_cmp (uhwi_to_double_int (offset), bitoffset, 0) < 0) |
2889 | return NULL_TREE; | |
cfef45c8 RG |
2890 | return fold_ctor_reference (type, cval, |
2891 | double_int_to_uhwi (inner_offset), size); | |
2892 | } | |
2893 | } | |
2894 | /* When memory is not explicitely mentioned in constructor, it is 0. */ | |
2895 | return build_zero_cst (type); | |
2896 | } | |
2897 | ||
2898 | /* CTOR is value initializing memory, fold reference of type TYPE and size SIZE | |
2899 | to the memory at bit OFFSET. */ | |
2900 | ||
2901 | static tree | |
2902 | fold_ctor_reference (tree type, tree ctor, unsigned HOST_WIDE_INT offset, | |
2903 | unsigned HOST_WIDE_INT size) | |
2904 | { | |
2905 | tree ret; | |
2906 | ||
2907 | /* We found the field with exact match. */ | |
2908 | if (useless_type_conversion_p (type, TREE_TYPE (ctor)) | |
2909 | && !offset) | |
2910 | return canonicalize_constructor_val (ctor); | |
2911 | ||
2912 | /* We are at the end of walk, see if we can view convert the | |
2913 | result. */ | |
2914 | if (!AGGREGATE_TYPE_P (TREE_TYPE (ctor)) && !offset | |
2915 | /* VIEW_CONVERT_EXPR is defined only for matching sizes. */ | |
2916 | && operand_equal_p (TYPE_SIZE (type), | |
2917 | TYPE_SIZE (TREE_TYPE (ctor)), 0)) | |
2918 | { | |
2919 | ret = canonicalize_constructor_val (ctor); | |
2920 | ret = fold_unary (VIEW_CONVERT_EXPR, type, ret); | |
2921 | if (ret) | |
2922 | STRIP_NOPS (ret); | |
2923 | return ret; | |
2924 | } | |
2925 | if (TREE_CODE (ctor) == STRING_CST) | |
2926 | return fold_string_cst_ctor_reference (type, ctor, offset, size); | |
2927 | if (TREE_CODE (ctor) == CONSTRUCTOR) | |
2928 | { | |
2929 | ||
eb8f1123 RG |
2930 | if (TREE_CODE (TREE_TYPE (ctor)) == ARRAY_TYPE |
2931 | || TREE_CODE (TREE_TYPE (ctor)) == VECTOR_TYPE) | |
cfef45c8 RG |
2932 | return fold_array_ctor_reference (type, ctor, offset, size); |
2933 | else | |
2934 | return fold_nonarray_ctor_reference (type, ctor, offset, size); | |
2935 | } | |
2936 | ||
2937 | return NULL_TREE; | |
2938 | } | |
2939 | ||
2940 | /* Return the tree representing the element referenced by T if T is an | |
2941 | ARRAY_REF or COMPONENT_REF into constant aggregates valuezing SSA | |
2942 | names using VALUEIZE. Return NULL_TREE otherwise. */ | |
2943 | ||
2944 | tree | |
2945 | fold_const_aggregate_ref_1 (tree t, tree (*valueize) (tree)) | |
2946 | { | |
2947 | tree ctor, idx, base; | |
2948 | HOST_WIDE_INT offset, size, max_size; | |
2949 | tree tem; | |
2950 | ||
f8a7df45 RG |
2951 | if (TREE_THIS_VOLATILE (t)) |
2952 | return NULL_TREE; | |
2953 | ||
cfef45c8 RG |
2954 | if (TREE_CODE_CLASS (TREE_CODE (t)) == tcc_declaration) |
2955 | return get_symbol_constant_value (t); | |
2956 | ||
2957 | tem = fold_read_from_constant_string (t); | |
2958 | if (tem) | |
2959 | return tem; | |
2960 | ||
2961 | switch (TREE_CODE (t)) | |
2962 | { | |
2963 | case ARRAY_REF: | |
2964 | case ARRAY_RANGE_REF: | |
2965 | /* Constant indexes are handled well by get_base_constructor. | |
2966 | Only special case variable offsets. | |
2967 | FIXME: This code can't handle nested references with variable indexes | |
2968 | (they will be handled only by iteration of ccp). Perhaps we can bring | |
2969 | get_ref_base_and_extent here and make it use a valueize callback. */ | |
2970 | if (TREE_CODE (TREE_OPERAND (t, 1)) == SSA_NAME | |
2971 | && valueize | |
2972 | && (idx = (*valueize) (TREE_OPERAND (t, 1))) | |
2973 | && host_integerp (idx, 0)) | |
2974 | { | |
2975 | tree low_bound, unit_size; | |
2976 | ||
2977 | /* If the resulting bit-offset is constant, track it. */ | |
2978 | if ((low_bound = array_ref_low_bound (t), | |
2979 | host_integerp (low_bound, 0)) | |
2980 | && (unit_size = array_ref_element_size (t), | |
2981 | host_integerp (unit_size, 1))) | |
2982 | { | |
2983 | offset = TREE_INT_CST_LOW (idx); | |
2984 | offset -= TREE_INT_CST_LOW (low_bound); | |
2985 | offset *= TREE_INT_CST_LOW (unit_size); | |
2986 | offset *= BITS_PER_UNIT; | |
2987 | ||
2988 | base = TREE_OPERAND (t, 0); | |
2989 | ctor = get_base_constructor (base, &offset, valueize); | |
2990 | /* Empty constructor. Always fold to 0. */ | |
2991 | if (ctor == error_mark_node) | |
2992 | return build_zero_cst (TREE_TYPE (t)); | |
2993 | /* Out of bound array access. Value is undefined, | |
2994 | but don't fold. */ | |
2995 | if (offset < 0) | |
2996 | return NULL_TREE; | |
2997 | /* We can not determine ctor. */ | |
2998 | if (!ctor) | |
2999 | return NULL_TREE; | |
3000 | return fold_ctor_reference (TREE_TYPE (t), ctor, offset, | |
3001 | TREE_INT_CST_LOW (unit_size) | |
3002 | * BITS_PER_UNIT); | |
3003 | } | |
3004 | } | |
3005 | /* Fallthru. */ | |
3006 | ||
3007 | case COMPONENT_REF: | |
3008 | case BIT_FIELD_REF: | |
3009 | case TARGET_MEM_REF: | |
3010 | case MEM_REF: | |
3011 | base = get_ref_base_and_extent (t, &offset, &size, &max_size); | |
3012 | ctor = get_base_constructor (base, &offset, valueize); | |
3013 | ||
3014 | /* Empty constructor. Always fold to 0. */ | |
3015 | if (ctor == error_mark_node) | |
3016 | return build_zero_cst (TREE_TYPE (t)); | |
3017 | /* We do not know precise address. */ | |
3018 | if (max_size == -1 || max_size != size) | |
3019 | return NULL_TREE; | |
3020 | /* We can not determine ctor. */ | |
3021 | if (!ctor) | |
3022 | return NULL_TREE; | |
3023 | ||
3024 | /* Out of bound array access. Value is undefined, but don't fold. */ | |
3025 | if (offset < 0) | |
3026 | return NULL_TREE; | |
3027 | ||
3028 | return fold_ctor_reference (TREE_TYPE (t), ctor, offset, size); | |
3029 | ||
3030 | case REALPART_EXPR: | |
3031 | case IMAGPART_EXPR: | |
3032 | { | |
3033 | tree c = fold_const_aggregate_ref_1 (TREE_OPERAND (t, 0), valueize); | |
3034 | if (c && TREE_CODE (c) == COMPLEX_CST) | |
3035 | return fold_build1_loc (EXPR_LOCATION (t), | |
3036 | TREE_CODE (t), TREE_TYPE (t), c); | |
3037 | break; | |
3038 | } | |
3039 | ||
3040 | default: | |
3041 | break; | |
3042 | } | |
3043 | ||
3044 | return NULL_TREE; | |
3045 | } | |
3046 | ||
3047 | tree | |
3048 | fold_const_aggregate_ref (tree t) | |
3049 | { | |
3050 | return fold_const_aggregate_ref_1 (t, NULL); | |
3051 | } | |
06bc3ec7 | 3052 | |
81fa35bd MJ |
3053 | /* Return a declaration of a function which an OBJ_TYPE_REF references. TOKEN |
3054 | is integer form of OBJ_TYPE_REF_TOKEN of the reference expression. | |
3055 | KNOWN_BINFO carries the binfo describing the true type of | |
3056 | OBJ_TYPE_REF_OBJECT(REF). */ | |
3057 | ||
3058 | tree | |
3059 | gimple_get_virt_method_for_binfo (HOST_WIDE_INT token, tree known_binfo) | |
3060 | { | |
3061 | unsigned HOST_WIDE_INT offset, size; | |
3062 | tree v, fn; | |
3063 | ||
3064 | v = BINFO_VTABLE (known_binfo); | |
3065 | /* If there is no virtual methods table, leave the OBJ_TYPE_REF alone. */ | |
3066 | if (!v) | |
3067 | return NULL_TREE; | |
3068 | ||
3069 | if (TREE_CODE (v) == POINTER_PLUS_EXPR) | |
3070 | { | |
3071 | offset = tree_low_cst (TREE_OPERAND (v, 1), 1) * BITS_PER_UNIT; | |
3072 | v = TREE_OPERAND (v, 0); | |
3073 | } | |
3074 | else | |
3075 | offset = 0; | |
3076 | ||
3077 | if (TREE_CODE (v) != ADDR_EXPR) | |
3078 | return NULL_TREE; | |
3079 | v = TREE_OPERAND (v, 0); | |
3080 | ||
3081 | if (TREE_CODE (v) != VAR_DECL | |
3082 | || !DECL_VIRTUAL_P (v) | |
5548ca35 JH |
3083 | || !DECL_INITIAL (v) |
3084 | || DECL_INITIAL (v) == error_mark_node) | |
81fa35bd MJ |
3085 | return NULL_TREE; |
3086 | gcc_checking_assert (TREE_CODE (TREE_TYPE (v)) == ARRAY_TYPE); | |
3087 | size = tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (v))), 1); | |
3088 | offset += token * size; | |
3089 | fn = fold_ctor_reference (TREE_TYPE (TREE_TYPE (v)), DECL_INITIAL (v), | |
3090 | offset, size); | |
8e8483e6 | 3091 | if (!fn || integer_zerop (fn)) |
81fa35bd MJ |
3092 | return NULL_TREE; |
3093 | gcc_assert (TREE_CODE (fn) == ADDR_EXPR | |
3094 | || TREE_CODE (fn) == FDESC_EXPR); | |
3095 | fn = TREE_OPERAND (fn, 0); | |
3096 | gcc_assert (TREE_CODE (fn) == FUNCTION_DECL); | |
3097 | ||
3098 | /* When cgraph node is missing and function is not public, we cannot | |
3099 | devirtualize. This can happen in WHOPR when the actual method | |
3100 | ends up in other partition, because we found devirtualization | |
3101 | possibility too late. */ | |
3102 | if (!can_refer_decl_in_current_unit_p (fn)) | |
3103 | return NULL_TREE; | |
3104 | ||
7501ca28 RG |
3105 | /* Make sure we create a cgraph node for functions we'll reference. |
3106 | They can be non-existent if the reference comes from an entry | |
3107 | of an external vtable for example. */ | |
3108 | cgraph_get_create_node (fn); | |
3109 | ||
81fa35bd MJ |
3110 | return fn; |
3111 | } | |
3112 | ||
06bc3ec7 BS |
3113 | /* Return true iff VAL is a gimple expression that is known to be |
3114 | non-negative. Restricted to floating-point inputs. */ | |
3115 | ||
3116 | bool | |
3117 | gimple_val_nonnegative_real_p (tree val) | |
3118 | { | |
3119 | gimple def_stmt; | |
3120 | ||
3121 | gcc_assert (val && SCALAR_FLOAT_TYPE_P (TREE_TYPE (val))); | |
3122 | ||
3123 | /* Use existing logic for non-gimple trees. */ | |
3124 | if (tree_expr_nonnegative_p (val)) | |
3125 | return true; | |
3126 | ||
3127 | if (TREE_CODE (val) != SSA_NAME) | |
3128 | return false; | |
3129 | ||
3130 | /* Currently we look only at the immediately defining statement | |
3131 | to make this determination, since recursion on defining | |
3132 | statements of operands can lead to quadratic behavior in the | |
3133 | worst case. This is expected to catch almost all occurrences | |
3134 | in practice. It would be possible to implement limited-depth | |
3135 | recursion if important cases are lost. Alternatively, passes | |
3136 | that need this information (such as the pow/powi lowering code | |
3137 | in the cse_sincos pass) could be revised to provide it through | |
3138 | dataflow propagation. */ | |
3139 | ||
3140 | def_stmt = SSA_NAME_DEF_STMT (val); | |
3141 | ||
3142 | if (is_gimple_assign (def_stmt)) | |
3143 | { | |
3144 | tree op0, op1; | |
3145 | ||
3146 | /* See fold-const.c:tree_expr_nonnegative_p for additional | |
3147 | cases that could be handled with recursion. */ | |
3148 | ||
3149 | switch (gimple_assign_rhs_code (def_stmt)) | |
3150 | { | |
3151 | case ABS_EXPR: | |
3152 | /* Always true for floating-point operands. */ | |
3153 | return true; | |
3154 | ||
3155 | case MULT_EXPR: | |
3156 | /* True if the two operands are identical (since we are | |
3157 | restricted to floating-point inputs). */ | |
3158 | op0 = gimple_assign_rhs1 (def_stmt); | |
3159 | op1 = gimple_assign_rhs2 (def_stmt); | |
3160 | ||
3161 | if (op0 == op1 | |
3162 | || operand_equal_p (op0, op1, 0)) | |
3163 | return true; | |
3164 | ||
3165 | default: | |
3166 | return false; | |
3167 | } | |
3168 | } | |
3169 | else if (is_gimple_call (def_stmt)) | |
3170 | { | |
3171 | tree fndecl = gimple_call_fndecl (def_stmt); | |
3172 | if (fndecl | |
3173 | && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL) | |
3174 | { | |
3175 | tree arg1; | |
3176 | ||
3177 | switch (DECL_FUNCTION_CODE (fndecl)) | |
3178 | { | |
3179 | CASE_FLT_FN (BUILT_IN_ACOS): | |
3180 | CASE_FLT_FN (BUILT_IN_ACOSH): | |
3181 | CASE_FLT_FN (BUILT_IN_CABS): | |
3182 | CASE_FLT_FN (BUILT_IN_COSH): | |
3183 | CASE_FLT_FN (BUILT_IN_ERFC): | |
3184 | CASE_FLT_FN (BUILT_IN_EXP): | |
3185 | CASE_FLT_FN (BUILT_IN_EXP10): | |
3186 | CASE_FLT_FN (BUILT_IN_EXP2): | |
3187 | CASE_FLT_FN (BUILT_IN_FABS): | |
3188 | CASE_FLT_FN (BUILT_IN_FDIM): | |
3189 | CASE_FLT_FN (BUILT_IN_HYPOT): | |
3190 | CASE_FLT_FN (BUILT_IN_POW10): | |
3191 | return true; | |
3192 | ||
3193 | CASE_FLT_FN (BUILT_IN_SQRT): | |
3194 | /* sqrt(-0.0) is -0.0, and sqrt is not defined over other | |
3195 | nonnegative inputs. */ | |
3196 | if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (val)))) | |
3197 | return true; | |
3198 | ||
3199 | break; | |
3200 | ||
3201 | CASE_FLT_FN (BUILT_IN_POWI): | |
3202 | /* True if the second argument is an even integer. */ | |
3203 | arg1 = gimple_call_arg (def_stmt, 1); | |
3204 | ||
3205 | if (TREE_CODE (arg1) == INTEGER_CST | |
3206 | && (TREE_INT_CST_LOW (arg1) & 1) == 0) | |
3207 | return true; | |
3208 | ||
3209 | break; | |
3210 | ||
3211 | CASE_FLT_FN (BUILT_IN_POW): | |
3212 | /* True if the second argument is an even integer-valued | |
3213 | real. */ | |
3214 | arg1 = gimple_call_arg (def_stmt, 1); | |
3215 | ||
3216 | if (TREE_CODE (arg1) == REAL_CST) | |
3217 | { | |
3218 | REAL_VALUE_TYPE c; | |
3219 | HOST_WIDE_INT n; | |
3220 | ||
3221 | c = TREE_REAL_CST (arg1); | |
3222 | n = real_to_integer (&c); | |
3223 | ||
3224 | if ((n & 1) == 0) | |
3225 | { | |
3226 | REAL_VALUE_TYPE cint; | |
3227 | real_from_integer (&cint, VOIDmode, n, n < 0 ? -1 : 0, 0); | |
3228 | if (real_identical (&c, &cint)) | |
3229 | return true; | |
3230 | } | |
3231 | } | |
3232 | ||
3233 | break; | |
3234 | ||
3235 | default: | |
3236 | return false; | |
3237 | } | |
3238 | } | |
3239 | } | |
3240 | ||
3241 | return false; | |
3242 | } |