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cbdd87d4 RG |
1 | /* Statement simplification on GIMPLE. |
2 | Copyright (C) 2010 Free Software Foundation, Inc. | |
3 | Split out from tree-ssa-ccp.c. | |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it | |
8 | under the terms of the GNU General Public License as published by the | |
9 | Free Software Foundation; either version 3, or (at your option) any | |
10 | later version. | |
11 | ||
12 | GCC is distributed in the hope that it will be useful, but WITHOUT | |
13 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GCC; see the file COPYING3. If not see | |
19 | <http://www.gnu.org/licenses/>. */ | |
20 | ||
21 | #include "config.h" | |
22 | #include "system.h" | |
23 | #include "coretypes.h" | |
24 | #include "tm.h" | |
25 | #include "tree.h" | |
26 | #include "flags.h" | |
cbdd87d4 | 27 | #include "function.h" |
cbdd87d4 RG |
28 | #include "tree-dump.h" |
29 | #include "tree-flow.h" | |
30 | #include "tree-pass.h" | |
31 | #include "tree-ssa-propagate.h" | |
cbdd87d4 RG |
32 | #include "target.h" |
33 | ||
b3b9f3d0 JH |
34 | /* Return true when DECL can be referenced from current unit. |
35 | We can get declarations that are not possible to reference for | |
36 | various reasons: | |
1389294c | 37 | |
1389294c JH |
38 | 1) When analyzing C++ virtual tables. |
39 | C++ virtual tables do have known constructors even | |
40 | when they are keyed to other compilation unit. | |
41 | Those tables can contain pointers to methods and vars | |
42 | in other units. Those methods have both STATIC and EXTERNAL | |
43 | set. | |
44 | 2) In WHOPR mode devirtualization might lead to reference | |
45 | to method that was partitioned elsehwere. | |
46 | In this case we have static VAR_DECL or FUNCTION_DECL | |
47 | that has no corresponding callgraph/varpool node | |
b3b9f3d0 JH |
48 | declaring the body. |
49 | 3) COMDAT functions referred by external vtables that | |
50 | we devirtualize only during final copmilation stage. | |
51 | At this time we already decided that we will not output | |
52 | the function body and thus we can't reference the symbol | |
53 | directly. */ | |
54 | ||
1389294c | 55 | static bool |
b3b9f3d0 | 56 | can_refer_decl_in_current_unit_p (tree decl) |
1389294c JH |
57 | { |
58 | struct varpool_node *vnode; | |
59 | struct cgraph_node *node; | |
60 | ||
b3b9f3d0 JH |
61 | if (!TREE_STATIC (decl) && !DECL_EXTERNAL (decl)) |
62 | return true; | |
1389294c JH |
63 | /* External flag is set, so we deal with C++ reference |
64 | to static object from other file. */ | |
b3b9f3d0 JH |
65 | if (DECL_EXTERNAL (decl) && TREE_STATIC (decl) |
66 | && TREE_CODE (decl) == VAR_DECL) | |
1389294c JH |
67 | { |
68 | /* Just be sure it is not big in frontend setting | |
69 | flags incorrectly. Those variables should never | |
70 | be finalized. */ | |
71 | gcc_checking_assert (!(vnode = varpool_get_node (decl)) | |
72 | || !vnode->finalized); | |
b3b9f3d0 | 73 | return false; |
1389294c | 74 | } |
b3b9f3d0 JH |
75 | /* When function is public, we always can introduce new reference. |
76 | Exception are the COMDAT functions where introducing a direct | |
77 | reference imply need to include function body in the curren tunit. */ | |
78 | if (TREE_PUBLIC (decl) && !DECL_COMDAT (decl)) | |
79 | return true; | |
80 | /* We are not at ltrans stage; so don't worry about WHOPR. | |
81 | Also when still gimplifying all referred comdat functions will be | |
82 | produced. */ | |
83 | if (!flag_ltrans && (!DECL_COMDAT (decl) || !cgraph_function_flags_ready)) | |
84 | return true; | |
85 | /* If we already output the function body, we are safe. */ | |
86 | if (TREE_ASM_WRITTEN (decl)) | |
87 | return true; | |
1389294c JH |
88 | if (TREE_CODE (decl) == FUNCTION_DECL) |
89 | { | |
90 | node = cgraph_get_node (decl); | |
b3b9f3d0 JH |
91 | /* Check that we still have function body and that we didn't took |
92 | the decision to eliminate offline copy of the function yet. | |
93 | The second is important when devirtualization happens during final | |
94 | compilation stage when making a new reference no longer makes callee | |
95 | to be compiled. */ | |
96 | if (!node || !node->analyzed || node->global.inlined_to) | |
97 | return false; | |
1389294c JH |
98 | } |
99 | else if (TREE_CODE (decl) == VAR_DECL) | |
100 | { | |
101 | vnode = varpool_get_node (decl); | |
102 | if (!vnode || !vnode->finalized) | |
b3b9f3d0 | 103 | return false; |
1389294c | 104 | } |
b3b9f3d0 | 105 | return true; |
1389294c JH |
106 | } |
107 | ||
17f39a39 JH |
108 | /* CVAL is value taken from DECL_INITIAL of variable. Try to transorm it into |
109 | acceptable form for is_gimple_min_invariant. */ | |
110 | ||
111 | tree | |
112 | canonicalize_constructor_val (tree cval) | |
113 | { | |
114 | STRIP_NOPS (cval); | |
115 | if (TREE_CODE (cval) == POINTER_PLUS_EXPR) | |
116 | { | |
117 | tree t = maybe_fold_offset_to_address (EXPR_LOCATION (cval), | |
118 | TREE_OPERAND (cval, 0), | |
119 | TREE_OPERAND (cval, 1), | |
120 | TREE_TYPE (cval)); | |
121 | if (t) | |
122 | cval = t; | |
123 | } | |
124 | if (TREE_CODE (cval) == ADDR_EXPR) | |
125 | { | |
126 | tree base = get_base_address (TREE_OPERAND (cval, 0)); | |
b3b9f3d0 | 127 | |
1389294c JH |
128 | if (base |
129 | && (TREE_CODE (base) == VAR_DECL | |
130 | || TREE_CODE (base) == FUNCTION_DECL) | |
b3b9f3d0 | 131 | && !can_refer_decl_in_current_unit_p (base)) |
1389294c | 132 | return NULL_TREE; |
17f39a39 JH |
133 | if (base && TREE_CODE (base) == VAR_DECL) |
134 | add_referenced_var (base); | |
73aef89e RG |
135 | /* We never have the chance to fixup types in global initializers |
136 | during gimplification. Do so here. */ | |
137 | if (TREE_TYPE (TREE_TYPE (cval)) != TREE_TYPE (TREE_OPERAND (cval, 0))) | |
138 | cval = build_fold_addr_expr (TREE_OPERAND (cval, 0)); | |
17f39a39 JH |
139 | } |
140 | return cval; | |
141 | } | |
cbdd87d4 RG |
142 | |
143 | /* If SYM is a constant variable with known value, return the value. | |
144 | NULL_TREE is returned otherwise. */ | |
145 | ||
146 | tree | |
147 | get_symbol_constant_value (tree sym) | |
148 | { | |
64e0f5ff | 149 | if (const_value_known_p (sym)) |
cbdd87d4 RG |
150 | { |
151 | tree val = DECL_INITIAL (sym); | |
152 | if (val) | |
153 | { | |
17f39a39 | 154 | val = canonicalize_constructor_val (val); |
1389294c | 155 | if (val && is_gimple_min_invariant (val)) |
17f39a39 | 156 | return val; |
1389294c JH |
157 | else |
158 | return NULL_TREE; | |
cbdd87d4 RG |
159 | } |
160 | /* Variables declared 'const' without an initializer | |
161 | have zero as the initializer if they may not be | |
162 | overridden at link or run time. */ | |
163 | if (!val | |
cbdd87d4 RG |
164 | && (INTEGRAL_TYPE_P (TREE_TYPE (sym)) |
165 | || SCALAR_FLOAT_TYPE_P (TREE_TYPE (sym)))) | |
e8160c9a | 166 | return build_zero_cst (TREE_TYPE (sym)); |
cbdd87d4 RG |
167 | } |
168 | ||
169 | return NULL_TREE; | |
170 | } | |
171 | ||
172 | ||
173 | /* Return true if we may propagate the address expression ADDR into the | |
174 | dereference DEREF and cancel them. */ | |
175 | ||
176 | bool | |
177 | may_propagate_address_into_dereference (tree addr, tree deref) | |
178 | { | |
70f34814 | 179 | gcc_assert (TREE_CODE (deref) == MEM_REF |
cbdd87d4 RG |
180 | && TREE_CODE (addr) == ADDR_EXPR); |
181 | ||
182 | /* Don't propagate if ADDR's operand has incomplete type. */ | |
183 | if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_OPERAND (addr, 0)))) | |
184 | return false; | |
185 | ||
186 | /* If the address is invariant then we do not need to preserve restrict | |
187 | qualifications. But we do need to preserve volatile qualifiers until | |
188 | we can annotate the folded dereference itself properly. */ | |
189 | if (is_gimple_min_invariant (addr) | |
190 | && (!TREE_THIS_VOLATILE (deref) | |
191 | || TYPE_VOLATILE (TREE_TYPE (addr)))) | |
192 | return useless_type_conversion_p (TREE_TYPE (deref), | |
193 | TREE_TYPE (TREE_OPERAND (addr, 0))); | |
194 | ||
195 | /* Else both the address substitution and the folding must result in | |
196 | a valid useless type conversion sequence. */ | |
197 | return (useless_type_conversion_p (TREE_TYPE (TREE_OPERAND (deref, 0)), | |
198 | TREE_TYPE (addr)) | |
199 | && useless_type_conversion_p (TREE_TYPE (deref), | |
200 | TREE_TYPE (TREE_OPERAND (addr, 0)))); | |
201 | } | |
202 | ||
203 | ||
204 | /* A subroutine of fold_stmt. Attempts to fold *(A+O) to A[X]. | |
70f34814 | 205 | BASE is an array type. OFFSET is a byte displacement. |
cbdd87d4 RG |
206 | |
207 | LOC is the location of the original expression. */ | |
208 | ||
209 | static tree | |
70f34814 | 210 | maybe_fold_offset_to_array_ref (location_t loc, tree base, tree offset) |
cbdd87d4 RG |
211 | { |
212 | tree min_idx, idx, idx_type, elt_offset = integer_zero_node; | |
213 | tree array_type, elt_type, elt_size; | |
214 | tree domain_type; | |
215 | ||
216 | /* If BASE is an ARRAY_REF, we can pick up another offset (this time | |
217 | measured in units of the size of elements type) from that ARRAY_REF). | |
218 | We can't do anything if either is variable. | |
219 | ||
220 | The case we handle here is *(&A[N]+O). */ | |
221 | if (TREE_CODE (base) == ARRAY_REF) | |
222 | { | |
223 | tree low_bound = array_ref_low_bound (base); | |
224 | ||
225 | elt_offset = TREE_OPERAND (base, 1); | |
226 | if (TREE_CODE (low_bound) != INTEGER_CST | |
227 | || TREE_CODE (elt_offset) != INTEGER_CST) | |
228 | return NULL_TREE; | |
229 | ||
230 | elt_offset = int_const_binop (MINUS_EXPR, elt_offset, low_bound, 0); | |
231 | base = TREE_OPERAND (base, 0); | |
232 | } | |
233 | ||
234 | /* Ignore stupid user tricks of indexing non-array variables. */ | |
235 | array_type = TREE_TYPE (base); | |
236 | if (TREE_CODE (array_type) != ARRAY_TYPE) | |
237 | return NULL_TREE; | |
238 | elt_type = TREE_TYPE (array_type); | |
cbdd87d4 RG |
239 | |
240 | /* Use signed size type for intermediate computation on the index. */ | |
3b9e5d95 | 241 | idx_type = ssizetype; |
cbdd87d4 RG |
242 | |
243 | /* If OFFSET and ELT_OFFSET are zero, we don't care about the size of the | |
244 | element type (so we can use the alignment if it's not constant). | |
245 | Otherwise, compute the offset as an index by using a division. If the | |
246 | division isn't exact, then don't do anything. */ | |
247 | elt_size = TYPE_SIZE_UNIT (elt_type); | |
248 | if (!elt_size) | |
249 | return NULL; | |
250 | if (integer_zerop (offset)) | |
251 | { | |
252 | if (TREE_CODE (elt_size) != INTEGER_CST) | |
253 | elt_size = size_int (TYPE_ALIGN (elt_type)); | |
254 | ||
255 | idx = build_int_cst (idx_type, 0); | |
256 | } | |
257 | else | |
258 | { | |
259 | unsigned HOST_WIDE_INT lquo, lrem; | |
260 | HOST_WIDE_INT hquo, hrem; | |
261 | double_int soffset; | |
262 | ||
263 | /* The final array offset should be signed, so we need | |
264 | to sign-extend the (possibly pointer) offset here | |
265 | and use signed division. */ | |
266 | soffset = double_int_sext (tree_to_double_int (offset), | |
267 | TYPE_PRECISION (TREE_TYPE (offset))); | |
268 | if (TREE_CODE (elt_size) != INTEGER_CST | |
269 | || div_and_round_double (TRUNC_DIV_EXPR, 0, | |
270 | soffset.low, soffset.high, | |
271 | TREE_INT_CST_LOW (elt_size), | |
272 | TREE_INT_CST_HIGH (elt_size), | |
273 | &lquo, &hquo, &lrem, &hrem) | |
274 | || lrem || hrem) | |
275 | return NULL_TREE; | |
276 | ||
277 | idx = build_int_cst_wide (idx_type, lquo, hquo); | |
278 | } | |
279 | ||
280 | /* Assume the low bound is zero. If there is a domain type, get the | |
281 | low bound, if any, convert the index into that type, and add the | |
282 | low bound. */ | |
283 | min_idx = build_int_cst (idx_type, 0); | |
284 | domain_type = TYPE_DOMAIN (array_type); | |
285 | if (domain_type) | |
286 | { | |
287 | idx_type = domain_type; | |
288 | if (TYPE_MIN_VALUE (idx_type)) | |
289 | min_idx = TYPE_MIN_VALUE (idx_type); | |
290 | else | |
291 | min_idx = fold_convert (idx_type, min_idx); | |
292 | ||
293 | if (TREE_CODE (min_idx) != INTEGER_CST) | |
294 | return NULL_TREE; | |
295 | ||
296 | elt_offset = fold_convert (idx_type, elt_offset); | |
297 | } | |
298 | ||
299 | if (!integer_zerop (min_idx)) | |
300 | idx = int_const_binop (PLUS_EXPR, idx, min_idx, 0); | |
301 | if (!integer_zerop (elt_offset)) | |
302 | idx = int_const_binop (PLUS_EXPR, idx, elt_offset, 0); | |
303 | ||
304 | /* Make sure to possibly truncate late after offsetting. */ | |
305 | idx = fold_convert (idx_type, idx); | |
306 | ||
307 | /* We don't want to construct access past array bounds. For example | |
308 | char *(c[4]); | |
309 | c[3][2]; | |
310 | should not be simplified into (*c)[14] or tree-vrp will | |
70f34814 RG |
311 | give false warnings. |
312 | This is only an issue for multi-dimensional arrays. */ | |
313 | if (TREE_CODE (elt_type) == ARRAY_TYPE | |
314 | && domain_type) | |
cbdd87d4 | 315 | { |
70f34814 RG |
316 | if (TYPE_MAX_VALUE (domain_type) |
317 | && TREE_CODE (TYPE_MAX_VALUE (domain_type)) == INTEGER_CST | |
318 | && tree_int_cst_lt (TYPE_MAX_VALUE (domain_type), idx)) | |
cbdd87d4 | 319 | return NULL_TREE; |
70f34814 RG |
320 | else if (TYPE_MIN_VALUE (domain_type) |
321 | && TREE_CODE (TYPE_MIN_VALUE (domain_type)) == INTEGER_CST | |
322 | && tree_int_cst_lt (idx, TYPE_MIN_VALUE (domain_type))) | |
323 | return NULL_TREE; | |
324 | else if (compare_tree_int (idx, 0) < 0) | |
cbdd87d4 RG |
325 | return NULL_TREE; |
326 | } | |
cbdd87d4 RG |
327 | |
328 | { | |
329 | tree t = build4 (ARRAY_REF, elt_type, base, idx, NULL_TREE, NULL_TREE); | |
330 | SET_EXPR_LOCATION (t, loc); | |
331 | return t; | |
332 | } | |
333 | } | |
334 | ||
335 | ||
70f34814 | 336 | /* Attempt to express (ORIG_TYPE)BASE+OFFSET as BASE[index]. |
cbdd87d4 RG |
337 | LOC is the location of original expression. |
338 | ||
70f34814 | 339 | Before attempting the conversion strip off existing ADDR_EXPRs. */ |
cbdd87d4 RG |
340 | |
341 | tree | |
342 | maybe_fold_offset_to_reference (location_t loc, tree base, tree offset, | |
343 | tree orig_type) | |
344 | { | |
345 | tree ret; | |
cbdd87d4 RG |
346 | |
347 | STRIP_NOPS (base); | |
348 | if (TREE_CODE (base) != ADDR_EXPR) | |
349 | return NULL_TREE; | |
350 | ||
351 | base = TREE_OPERAND (base, 0); | |
70f34814 | 352 | if (types_compatible_p (orig_type, TREE_TYPE (base)) |
cbdd87d4 RG |
353 | && integer_zerop (offset)) |
354 | return base; | |
cbdd87d4 | 355 | |
70f34814 RG |
356 | ret = maybe_fold_offset_to_array_ref (loc, base, offset); |
357 | if (ret && types_compatible_p (orig_type, TREE_TYPE (ret))) | |
358 | return ret; | |
359 | return NULL_TREE; | |
cbdd87d4 RG |
360 | } |
361 | ||
70f34814 RG |
362 | /* Attempt to express (ORIG_TYPE)ADDR+OFFSET as (*ADDR)[index]. |
363 | LOC is the location of the original expression. */ | |
cbdd87d4 RG |
364 | |
365 | tree | |
366 | maybe_fold_offset_to_address (location_t loc, tree addr, tree offset, | |
367 | tree orig_type) | |
368 | { | |
70f34814 | 369 | tree base, ret; |
cbdd87d4 | 370 | |
70f34814 RG |
371 | STRIP_NOPS (addr); |
372 | if (TREE_CODE (addr) != ADDR_EXPR) | |
373 | return NULL_TREE; | |
374 | base = TREE_OPERAND (addr, 0); | |
375 | ret = maybe_fold_offset_to_array_ref (loc, base, offset); | |
376 | if (ret) | |
cbdd87d4 | 377 | { |
70f34814 RG |
378 | ret = build_fold_addr_expr (ret); |
379 | if (!useless_type_conversion_p (orig_type, TREE_TYPE (ret))) | |
cbdd87d4 | 380 | return NULL_TREE; |
70f34814 | 381 | SET_EXPR_LOCATION (ret, loc); |
cbdd87d4 RG |
382 | } |
383 | ||
70f34814 | 384 | return ret; |
cbdd87d4 RG |
385 | } |
386 | ||
387 | ||
388 | /* A quaint feature extant in our address arithmetic is that there | |
389 | can be hidden type changes here. The type of the result need | |
390 | not be the same as the type of the input pointer. | |
391 | ||
392 | What we're after here is an expression of the form | |
393 | (T *)(&array + const) | |
394 | where array is OP0, const is OP1, RES_TYPE is T and | |
395 | the cast doesn't actually exist, but is implicit in the | |
396 | type of the POINTER_PLUS_EXPR. We'd like to turn this into | |
397 | &array[x] | |
398 | which may be able to propagate further. */ | |
399 | ||
400 | tree | |
401 | maybe_fold_stmt_addition (location_t loc, tree res_type, tree op0, tree op1) | |
402 | { | |
403 | tree ptd_type; | |
404 | tree t; | |
405 | ||
406 | /* The first operand should be an ADDR_EXPR. */ | |
407 | if (TREE_CODE (op0) != ADDR_EXPR) | |
408 | return NULL_TREE; | |
409 | op0 = TREE_OPERAND (op0, 0); | |
410 | ||
411 | /* It had better be a constant. */ | |
412 | if (TREE_CODE (op1) != INTEGER_CST) | |
413 | { | |
414 | /* Or op0 should now be A[0] and the non-constant offset defined | |
415 | via a multiplication by the array element size. */ | |
416 | if (TREE_CODE (op0) == ARRAY_REF | |
c946a318 RG |
417 | /* As we will end up creating a variable index array access |
418 | in the outermost array dimension make sure there isn't | |
419 | a more inner array that the index could overflow to. */ | |
70f34814 RG |
420 | && TREE_CODE (TREE_OPERAND (op0, 0)) != ARRAY_REF |
421 | && integer_zerop (TREE_OPERAND (op0, 1)) | |
422 | && TREE_CODE (op1) == SSA_NAME) | |
423 | { | |
424 | gimple offset_def = SSA_NAME_DEF_STMT (op1); | |
425 | tree elsz = TYPE_SIZE_UNIT (TREE_TYPE (op0)); | |
426 | if (!host_integerp (elsz, 1) | |
427 | || !is_gimple_assign (offset_def)) | |
c946a318 RG |
428 | return NULL_TREE; |
429 | ||
430 | /* Do not build array references of something that we can't | |
431 | see the true number of array dimensions for. */ | |
432 | if (!DECL_P (TREE_OPERAND (op0, 0)) | |
433 | && !handled_component_p (TREE_OPERAND (op0, 0))) | |
434 | return NULL_TREE; | |
435 | ||
cbdd87d4 RG |
436 | if (gimple_assign_rhs_code (offset_def) == MULT_EXPR |
437 | && TREE_CODE (gimple_assign_rhs2 (offset_def)) == INTEGER_CST | |
70f34814 | 438 | && tree_int_cst_equal (gimple_assign_rhs2 (offset_def), elsz)) |
cbdd87d4 RG |
439 | return build_fold_addr_expr |
440 | (build4 (ARRAY_REF, TREE_TYPE (op0), | |
441 | TREE_OPERAND (op0, 0), | |
442 | gimple_assign_rhs1 (offset_def), | |
443 | TREE_OPERAND (op0, 2), | |
444 | TREE_OPERAND (op0, 3))); | |
70f34814 | 445 | else if (integer_onep (elsz) |
cbdd87d4 RG |
446 | && gimple_assign_rhs_code (offset_def) != MULT_EXPR) |
447 | return build_fold_addr_expr | |
448 | (build4 (ARRAY_REF, TREE_TYPE (op0), | |
449 | TREE_OPERAND (op0, 0), | |
450 | op1, | |
451 | TREE_OPERAND (op0, 2), | |
452 | TREE_OPERAND (op0, 3))); | |
453 | } | |
70f34814 RG |
454 | else if (TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE |
455 | /* Dto. */ | |
456 | && TREE_CODE (TREE_TYPE (TREE_TYPE (op0))) != ARRAY_TYPE | |
457 | && TREE_CODE (op1) == SSA_NAME) | |
458 | { | |
459 | gimple offset_def = SSA_NAME_DEF_STMT (op1); | |
460 | tree elsz = TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (op0))); | |
461 | if (!host_integerp (elsz, 1) | |
462 | || !is_gimple_assign (offset_def)) | |
463 | return NULL_TREE; | |
464 | ||
465 | /* Do not build array references of something that we can't | |
466 | see the true number of array dimensions for. */ | |
467 | if (!DECL_P (op0) | |
468 | && !handled_component_p (op0)) | |
469 | return NULL_TREE; | |
470 | ||
471 | if (gimple_assign_rhs_code (offset_def) == MULT_EXPR | |
472 | && TREE_CODE (gimple_assign_rhs2 (offset_def)) == INTEGER_CST | |
473 | && tree_int_cst_equal (gimple_assign_rhs2 (offset_def), elsz)) | |
474 | return build_fold_addr_expr | |
475 | (build4 (ARRAY_REF, TREE_TYPE (TREE_TYPE (op0)), | |
476 | op0, gimple_assign_rhs1 (offset_def), | |
477 | integer_zero_node, NULL_TREE)); | |
478 | else if (integer_onep (elsz) | |
479 | && gimple_assign_rhs_code (offset_def) != MULT_EXPR) | |
480 | return build_fold_addr_expr | |
481 | (build4 (ARRAY_REF, TREE_TYPE (TREE_TYPE (op0)), | |
482 | op0, op1, | |
483 | integer_zero_node, NULL_TREE)); | |
484 | } | |
485 | ||
cbdd87d4 RG |
486 | return NULL_TREE; |
487 | } | |
488 | ||
489 | /* If the first operand is an ARRAY_REF, expand it so that we can fold | |
490 | the offset into it. */ | |
491 | while (TREE_CODE (op0) == ARRAY_REF) | |
492 | { | |
493 | tree array_obj = TREE_OPERAND (op0, 0); | |
494 | tree array_idx = TREE_OPERAND (op0, 1); | |
495 | tree elt_type = TREE_TYPE (op0); | |
496 | tree elt_size = TYPE_SIZE_UNIT (elt_type); | |
497 | tree min_idx; | |
498 | ||
499 | if (TREE_CODE (array_idx) != INTEGER_CST) | |
500 | break; | |
501 | if (TREE_CODE (elt_size) != INTEGER_CST) | |
502 | break; | |
503 | ||
504 | /* Un-bias the index by the min index of the array type. */ | |
505 | min_idx = TYPE_DOMAIN (TREE_TYPE (array_obj)); | |
506 | if (min_idx) | |
507 | { | |
508 | min_idx = TYPE_MIN_VALUE (min_idx); | |
509 | if (min_idx) | |
510 | { | |
511 | if (TREE_CODE (min_idx) != INTEGER_CST) | |
512 | break; | |
513 | ||
514 | array_idx = fold_convert (TREE_TYPE (min_idx), array_idx); | |
515 | if (!integer_zerop (min_idx)) | |
516 | array_idx = int_const_binop (MINUS_EXPR, array_idx, | |
517 | min_idx, 0); | |
518 | } | |
519 | } | |
520 | ||
521 | /* Convert the index to a byte offset. */ | |
522 | array_idx = fold_convert (sizetype, array_idx); | |
523 | array_idx = int_const_binop (MULT_EXPR, array_idx, elt_size, 0); | |
524 | ||
525 | /* Update the operands for the next round, or for folding. */ | |
526 | op1 = int_const_binop (PLUS_EXPR, | |
527 | array_idx, op1, 0); | |
528 | op0 = array_obj; | |
529 | } | |
530 | ||
531 | ptd_type = TREE_TYPE (res_type); | |
532 | /* If we want a pointer to void, reconstruct the reference from the | |
533 | array element type. A pointer to that can be trivially converted | |
534 | to void *. This happens as we fold (void *)(ptr p+ off). */ | |
535 | if (VOID_TYPE_P (ptd_type) | |
536 | && TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE) | |
537 | ptd_type = TREE_TYPE (TREE_TYPE (op0)); | |
538 | ||
539 | /* At which point we can try some of the same things as for indirects. */ | |
70f34814 | 540 | t = maybe_fold_offset_to_array_ref (loc, op0, op1); |
cbdd87d4 RG |
541 | if (t) |
542 | { | |
70f34814 RG |
543 | t = build_fold_addr_expr (t); |
544 | if (!useless_type_conversion_p (res_type, TREE_TYPE (t))) | |
545 | return NULL_TREE; | |
cbdd87d4 RG |
546 | SET_EXPR_LOCATION (t, loc); |
547 | } | |
548 | ||
549 | return t; | |
550 | } | |
551 | ||
552 | /* Subroutine of fold_stmt. We perform several simplifications of the | |
553 | memory reference tree EXPR and make sure to re-gimplify them properly | |
554 | after propagation of constant addresses. IS_LHS is true if the | |
555 | reference is supposed to be an lvalue. */ | |
556 | ||
557 | static tree | |
558 | maybe_fold_reference (tree expr, bool is_lhs) | |
559 | { | |
560 | tree *t = &expr; | |
17f39a39 | 561 | tree result; |
cbdd87d4 | 562 | |
17f39a39 | 563 | if (!is_lhs |
8683f051 JH |
564 | && (result = fold_const_aggregate_ref (expr)) |
565 | && is_gimple_min_invariant (result)) | |
17f39a39 | 566 | return result; |
cbdd87d4 RG |
567 | |
568 | /* ??? We might want to open-code the relevant remaining cases | |
569 | to avoid using the generic fold. */ | |
570 | if (handled_component_p (*t) | |
571 | && CONSTANT_CLASS_P (TREE_OPERAND (*t, 0))) | |
572 | { | |
573 | tree tem = fold (*t); | |
574 | if (tem != *t) | |
575 | return tem; | |
576 | } | |
577 | ||
578 | while (handled_component_p (*t)) | |
579 | t = &TREE_OPERAND (*t, 0); | |
580 | ||
70f34814 RG |
581 | /* Fold back MEM_REFs to reference trees. */ |
582 | if (TREE_CODE (*t) == MEM_REF | |
583 | && TREE_CODE (TREE_OPERAND (*t, 0)) == ADDR_EXPR | |
584 | && integer_zerop (TREE_OPERAND (*t, 1)) | |
585 | && (TREE_THIS_VOLATILE (*t) | |
586 | == TREE_THIS_VOLATILE (TREE_OPERAND (TREE_OPERAND (*t, 0), 0))) | |
587 | && !TYPE_REF_CAN_ALIAS_ALL (TREE_TYPE (TREE_OPERAND (*t, 1))) | |
588 | && (TYPE_MAIN_VARIANT (TREE_TYPE (*t)) | |
589 | == TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (TREE_OPERAND (*t, 1))))) | |
590 | /* We have to look out here to not drop a required conversion | |
591 | from the rhs to the lhs if is_lhs, but we don't have the | |
592 | rhs here to verify that. Thus require strict type | |
593 | compatibility. */ | |
594 | && types_compatible_p (TREE_TYPE (*t), | |
595 | TREE_TYPE (TREE_OPERAND | |
596 | (TREE_OPERAND (*t, 0), 0)))) | |
cbdd87d4 | 597 | { |
70f34814 RG |
598 | tree tem; |
599 | *t = TREE_OPERAND (TREE_OPERAND (*t, 0), 0); | |
600 | tem = maybe_fold_reference (expr, is_lhs); | |
601 | if (tem) | |
602 | return tem; | |
603 | return expr; | |
604 | } | |
605 | /* Canonicalize MEM_REFs invariant address operand. */ | |
606 | else if (TREE_CODE (*t) == MEM_REF | |
e9615971 | 607 | && !is_gimple_mem_ref_addr (TREE_OPERAND (*t, 0))) |
70f34814 | 608 | { |
e9615971 | 609 | bool volatile_p = TREE_THIS_VOLATILE (*t); |
70f34814 RG |
610 | tree tem = fold_binary (MEM_REF, TREE_TYPE (*t), |
611 | TREE_OPERAND (*t, 0), | |
612 | TREE_OPERAND (*t, 1)); | |
cbdd87d4 RG |
613 | if (tem) |
614 | { | |
e9615971 | 615 | TREE_THIS_VOLATILE (tem) = volatile_p; |
cbdd87d4 RG |
616 | *t = tem; |
617 | tem = maybe_fold_reference (expr, is_lhs); | |
618 | if (tem) | |
619 | return tem; | |
620 | return expr; | |
621 | } | |
622 | } | |
4d948885 RG |
623 | else if (TREE_CODE (*t) == TARGET_MEM_REF) |
624 | { | |
625 | tree tem = maybe_fold_tmr (*t); | |
626 | if (tem) | |
627 | { | |
628 | *t = tem; | |
629 | tem = maybe_fold_reference (expr, is_lhs); | |
630 | if (tem) | |
631 | return tem; | |
632 | return expr; | |
633 | } | |
634 | } | |
cbdd87d4 RG |
635 | else if (!is_lhs |
636 | && DECL_P (*t)) | |
637 | { | |
638 | tree tem = get_symbol_constant_value (*t); | |
639 | if (tem | |
640 | && useless_type_conversion_p (TREE_TYPE (*t), TREE_TYPE (tem))) | |
641 | { | |
642 | *t = unshare_expr (tem); | |
643 | tem = maybe_fold_reference (expr, is_lhs); | |
644 | if (tem) | |
645 | return tem; | |
646 | return expr; | |
647 | } | |
648 | } | |
649 | ||
650 | return NULL_TREE; | |
651 | } | |
652 | ||
653 | ||
654 | /* Attempt to fold an assignment statement pointed-to by SI. Returns a | |
655 | replacement rhs for the statement or NULL_TREE if no simplification | |
656 | could be made. It is assumed that the operands have been previously | |
657 | folded. */ | |
658 | ||
659 | static tree | |
660 | fold_gimple_assign (gimple_stmt_iterator *si) | |
661 | { | |
662 | gimple stmt = gsi_stmt (*si); | |
663 | enum tree_code subcode = gimple_assign_rhs_code (stmt); | |
664 | location_t loc = gimple_location (stmt); | |
665 | ||
666 | tree result = NULL_TREE; | |
667 | ||
668 | switch (get_gimple_rhs_class (subcode)) | |
669 | { | |
670 | case GIMPLE_SINGLE_RHS: | |
671 | { | |
672 | tree rhs = gimple_assign_rhs1 (stmt); | |
673 | ||
674 | /* Try to fold a conditional expression. */ | |
675 | if (TREE_CODE (rhs) == COND_EXPR) | |
676 | { | |
677 | tree op0 = COND_EXPR_COND (rhs); | |
678 | tree tem; | |
679 | bool set = false; | |
680 | location_t cond_loc = EXPR_LOCATION (rhs); | |
681 | ||
682 | if (COMPARISON_CLASS_P (op0)) | |
683 | { | |
684 | fold_defer_overflow_warnings (); | |
685 | tem = fold_binary_loc (cond_loc, | |
686 | TREE_CODE (op0), TREE_TYPE (op0), | |
687 | TREE_OPERAND (op0, 0), | |
688 | TREE_OPERAND (op0, 1)); | |
689 | /* This is actually a conditional expression, not a GIMPLE | |
690 | conditional statement, however, the valid_gimple_rhs_p | |
691 | test still applies. */ | |
692 | set = (tem && is_gimple_condexpr (tem) | |
693 | && valid_gimple_rhs_p (tem)); | |
694 | fold_undefer_overflow_warnings (set, stmt, 0); | |
695 | } | |
696 | else if (is_gimple_min_invariant (op0)) | |
697 | { | |
698 | tem = op0; | |
699 | set = true; | |
700 | } | |
701 | else | |
702 | return NULL_TREE; | |
703 | ||
704 | if (set) | |
705 | result = fold_build3_loc (cond_loc, COND_EXPR, TREE_TYPE (rhs), tem, | |
706 | COND_EXPR_THEN (rhs), COND_EXPR_ELSE (rhs)); | |
707 | } | |
708 | ||
cbdd87d4 RG |
709 | else if (REFERENCE_CLASS_P (rhs)) |
710 | return maybe_fold_reference (rhs, false); | |
711 | ||
712 | else if (TREE_CODE (rhs) == ADDR_EXPR) | |
713 | { | |
70f34814 RG |
714 | tree ref = TREE_OPERAND (rhs, 0); |
715 | tree tem = maybe_fold_reference (ref, true); | |
716 | if (tem | |
717 | && TREE_CODE (tem) == MEM_REF | |
718 | && integer_zerop (TREE_OPERAND (tem, 1))) | |
719 | result = fold_convert (TREE_TYPE (rhs), TREE_OPERAND (tem, 0)); | |
720 | else if (tem) | |
cbdd87d4 RG |
721 | result = fold_convert (TREE_TYPE (rhs), |
722 | build_fold_addr_expr_loc (loc, tem)); | |
70f34814 RG |
723 | else if (TREE_CODE (ref) == MEM_REF |
724 | && integer_zerop (TREE_OPERAND (ref, 1))) | |
725 | result = fold_convert (TREE_TYPE (rhs), TREE_OPERAND (ref, 0)); | |
cbdd87d4 RG |
726 | } |
727 | ||
728 | else if (TREE_CODE (rhs) == CONSTRUCTOR | |
729 | && TREE_CODE (TREE_TYPE (rhs)) == VECTOR_TYPE | |
730 | && (CONSTRUCTOR_NELTS (rhs) | |
731 | == TYPE_VECTOR_SUBPARTS (TREE_TYPE (rhs)))) | |
732 | { | |
733 | /* Fold a constant vector CONSTRUCTOR to VECTOR_CST. */ | |
734 | unsigned i; | |
735 | tree val; | |
736 | ||
737 | FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (rhs), i, val) | |
738 | if (TREE_CODE (val) != INTEGER_CST | |
739 | && TREE_CODE (val) != REAL_CST | |
740 | && TREE_CODE (val) != FIXED_CST) | |
741 | return NULL_TREE; | |
742 | ||
743 | return build_vector_from_ctor (TREE_TYPE (rhs), | |
744 | CONSTRUCTOR_ELTS (rhs)); | |
745 | } | |
746 | ||
747 | else if (DECL_P (rhs)) | |
748 | return unshare_expr (get_symbol_constant_value (rhs)); | |
749 | ||
750 | /* If we couldn't fold the RHS, hand over to the generic | |
751 | fold routines. */ | |
752 | if (result == NULL_TREE) | |
753 | result = fold (rhs); | |
754 | ||
755 | /* Strip away useless type conversions. Both the NON_LVALUE_EXPR | |
756 | that may have been added by fold, and "useless" type | |
757 | conversions that might now be apparent due to propagation. */ | |
758 | STRIP_USELESS_TYPE_CONVERSION (result); | |
759 | ||
760 | if (result != rhs && valid_gimple_rhs_p (result)) | |
761 | return result; | |
762 | ||
763 | return NULL_TREE; | |
764 | } | |
765 | break; | |
766 | ||
767 | case GIMPLE_UNARY_RHS: | |
768 | { | |
769 | tree rhs = gimple_assign_rhs1 (stmt); | |
770 | ||
771 | result = fold_unary_loc (loc, subcode, gimple_expr_type (stmt), rhs); | |
772 | if (result) | |
773 | { | |
774 | /* If the operation was a conversion do _not_ mark a | |
775 | resulting constant with TREE_OVERFLOW if the original | |
776 | constant was not. These conversions have implementation | |
777 | defined behavior and retaining the TREE_OVERFLOW flag | |
778 | here would confuse later passes such as VRP. */ | |
779 | if (CONVERT_EXPR_CODE_P (subcode) | |
780 | && TREE_CODE (result) == INTEGER_CST | |
781 | && TREE_CODE (rhs) == INTEGER_CST) | |
782 | TREE_OVERFLOW (result) = TREE_OVERFLOW (rhs); | |
783 | ||
784 | STRIP_USELESS_TYPE_CONVERSION (result); | |
785 | if (valid_gimple_rhs_p (result)) | |
786 | return result; | |
787 | } | |
788 | else if (CONVERT_EXPR_CODE_P (subcode) | |
789 | && POINTER_TYPE_P (gimple_expr_type (stmt)) | |
790 | && POINTER_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (stmt)))) | |
791 | { | |
792 | tree type = gimple_expr_type (stmt); | |
793 | tree t = maybe_fold_offset_to_address (loc, | |
794 | gimple_assign_rhs1 (stmt), | |
795 | integer_zero_node, type); | |
796 | if (t) | |
797 | return t; | |
798 | } | |
799 | } | |
800 | break; | |
801 | ||
802 | case GIMPLE_BINARY_RHS: | |
803 | /* Try to fold pointer addition. */ | |
804 | if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR) | |
805 | { | |
806 | tree type = TREE_TYPE (gimple_assign_rhs1 (stmt)); | |
807 | if (TREE_CODE (TREE_TYPE (type)) == ARRAY_TYPE) | |
808 | { | |
809 | type = build_pointer_type (TREE_TYPE (TREE_TYPE (type))); | |
810 | if (!useless_type_conversion_p | |
811 | (TREE_TYPE (gimple_assign_lhs (stmt)), type)) | |
812 | type = TREE_TYPE (gimple_assign_rhs1 (stmt)); | |
813 | } | |
814 | result = maybe_fold_stmt_addition (gimple_location (stmt), | |
815 | type, | |
816 | gimple_assign_rhs1 (stmt), | |
817 | gimple_assign_rhs2 (stmt)); | |
818 | } | |
819 | ||
820 | if (!result) | |
821 | result = fold_binary_loc (loc, subcode, | |
822 | TREE_TYPE (gimple_assign_lhs (stmt)), | |
823 | gimple_assign_rhs1 (stmt), | |
824 | gimple_assign_rhs2 (stmt)); | |
825 | ||
826 | if (result) | |
827 | { | |
828 | STRIP_USELESS_TYPE_CONVERSION (result); | |
829 | if (valid_gimple_rhs_p (result)) | |
830 | return result; | |
831 | ||
832 | /* Fold might have produced non-GIMPLE, so if we trust it blindly | |
833 | we lose canonicalization opportunities. Do not go again | |
834 | through fold here though, or the same non-GIMPLE will be | |
835 | produced. */ | |
836 | if (commutative_tree_code (subcode) | |
837 | && tree_swap_operands_p (gimple_assign_rhs1 (stmt), | |
838 | gimple_assign_rhs2 (stmt), false)) | |
839 | return build2 (subcode, TREE_TYPE (gimple_assign_lhs (stmt)), | |
840 | gimple_assign_rhs2 (stmt), | |
841 | gimple_assign_rhs1 (stmt)); | |
842 | } | |
843 | break; | |
844 | ||
0354c0c7 BS |
845 | case GIMPLE_TERNARY_RHS: |
846 | result = fold_ternary_loc (loc, subcode, | |
847 | TREE_TYPE (gimple_assign_lhs (stmt)), | |
848 | gimple_assign_rhs1 (stmt), | |
849 | gimple_assign_rhs2 (stmt), | |
850 | gimple_assign_rhs3 (stmt)); | |
851 | ||
852 | if (result) | |
853 | { | |
854 | STRIP_USELESS_TYPE_CONVERSION (result); | |
855 | if (valid_gimple_rhs_p (result)) | |
856 | return result; | |
857 | ||
858 | /* Fold might have produced non-GIMPLE, so if we trust it blindly | |
859 | we lose canonicalization opportunities. Do not go again | |
860 | through fold here though, or the same non-GIMPLE will be | |
861 | produced. */ | |
862 | if (commutative_ternary_tree_code (subcode) | |
863 | && tree_swap_operands_p (gimple_assign_rhs1 (stmt), | |
864 | gimple_assign_rhs2 (stmt), false)) | |
865 | return build3 (subcode, TREE_TYPE (gimple_assign_lhs (stmt)), | |
866 | gimple_assign_rhs2 (stmt), | |
867 | gimple_assign_rhs1 (stmt), | |
868 | gimple_assign_rhs3 (stmt)); | |
869 | } | |
870 | break; | |
871 | ||
cbdd87d4 RG |
872 | case GIMPLE_INVALID_RHS: |
873 | gcc_unreachable (); | |
874 | } | |
875 | ||
876 | return NULL_TREE; | |
877 | } | |
878 | ||
879 | /* Attempt to fold a conditional statement. Return true if any changes were | |
880 | made. We only attempt to fold the condition expression, and do not perform | |
881 | any transformation that would require alteration of the cfg. It is | |
882 | assumed that the operands have been previously folded. */ | |
883 | ||
884 | static bool | |
885 | fold_gimple_cond (gimple stmt) | |
886 | { | |
887 | tree result = fold_binary_loc (gimple_location (stmt), | |
888 | gimple_cond_code (stmt), | |
889 | boolean_type_node, | |
890 | gimple_cond_lhs (stmt), | |
891 | gimple_cond_rhs (stmt)); | |
892 | ||
893 | if (result) | |
894 | { | |
895 | STRIP_USELESS_TYPE_CONVERSION (result); | |
896 | if (is_gimple_condexpr (result) && valid_gimple_rhs_p (result)) | |
897 | { | |
898 | gimple_cond_set_condition_from_tree (stmt, result); | |
899 | return true; | |
900 | } | |
901 | } | |
902 | ||
903 | return false; | |
904 | } | |
905 | ||
906 | /* Convert EXPR into a GIMPLE value suitable for substitution on the | |
907 | RHS of an assignment. Insert the necessary statements before | |
908 | iterator *SI_P. The statement at *SI_P, which must be a GIMPLE_CALL | |
909 | is replaced. If the call is expected to produces a result, then it | |
910 | is replaced by an assignment of the new RHS to the result variable. | |
911 | If the result is to be ignored, then the call is replaced by a | |
fe2ef088 MM |
912 | GIMPLE_NOP. A proper VDEF chain is retained by making the first |
913 | VUSE and the last VDEF of the whole sequence be the same as the replaced | |
914 | statement and using new SSA names for stores in between. */ | |
cbdd87d4 RG |
915 | |
916 | void | |
917 | gimplify_and_update_call_from_tree (gimple_stmt_iterator *si_p, tree expr) | |
918 | { | |
919 | tree lhs; | |
920 | tree tmp = NULL_TREE; /* Silence warning. */ | |
921 | gimple stmt, new_stmt; | |
922 | gimple_stmt_iterator i; | |
923 | gimple_seq stmts = gimple_seq_alloc(); | |
924 | struct gimplify_ctx gctx; | |
925 | gimple last = NULL; | |
fe2ef088 MM |
926 | gimple laststore = NULL; |
927 | tree reaching_vuse; | |
cbdd87d4 RG |
928 | |
929 | stmt = gsi_stmt (*si_p); | |
930 | ||
931 | gcc_assert (is_gimple_call (stmt)); | |
932 | ||
933 | lhs = gimple_call_lhs (stmt); | |
fe2ef088 | 934 | reaching_vuse = gimple_vuse (stmt); |
cbdd87d4 RG |
935 | |
936 | push_gimplify_context (&gctx); | |
937 | ||
938 | if (lhs == NULL_TREE) | |
6e572326 RG |
939 | { |
940 | gimplify_and_add (expr, &stmts); | |
941 | /* We can end up with folding a memcpy of an empty class assignment | |
942 | which gets optimized away by C++ gimplification. */ | |
943 | if (gimple_seq_empty_p (stmts)) | |
944 | { | |
945 | if (gimple_in_ssa_p (cfun)) | |
946 | { | |
947 | unlink_stmt_vdef (stmt); | |
948 | release_defs (stmt); | |
949 | } | |
950 | gsi_remove (si_p, true); | |
951 | return; | |
952 | } | |
953 | } | |
cbdd87d4 RG |
954 | else |
955 | tmp = get_initialized_tmp_var (expr, &stmts, NULL); | |
956 | ||
957 | pop_gimplify_context (NULL); | |
958 | ||
959 | if (gimple_has_location (stmt)) | |
960 | annotate_all_with_location (stmts, gimple_location (stmt)); | |
961 | ||
962 | /* The replacement can expose previously unreferenced variables. */ | |
963 | for (i = gsi_start (stmts); !gsi_end_p (i); gsi_next (&i)) | |
964 | { | |
965 | if (last) | |
966 | { | |
967 | gsi_insert_before (si_p, last, GSI_NEW_STMT); | |
968 | gsi_next (si_p); | |
969 | } | |
970 | new_stmt = gsi_stmt (i); | |
edc74207 RG |
971 | if (gimple_in_ssa_p (cfun)) |
972 | { | |
973 | find_new_referenced_vars (new_stmt); | |
974 | mark_symbols_for_renaming (new_stmt); | |
975 | } | |
fe2ef088 MM |
976 | /* If the new statement has a VUSE, update it with exact SSA name we |
977 | know will reach this one. */ | |
978 | if (gimple_vuse (new_stmt)) | |
979 | { | |
980 | /* If we've also seen a previous store create a new VDEF for | |
981 | the latter one, and make that the new reaching VUSE. */ | |
982 | if (laststore) | |
983 | { | |
984 | reaching_vuse = make_ssa_name (gimple_vop (cfun), laststore); | |
985 | gimple_set_vdef (laststore, reaching_vuse); | |
986 | update_stmt (laststore); | |
987 | laststore = NULL; | |
988 | } | |
989 | gimple_set_vuse (new_stmt, reaching_vuse); | |
990 | gimple_set_modified (new_stmt, true); | |
991 | } | |
992 | if (gimple_assign_single_p (new_stmt) | |
993 | && !is_gimple_reg (gimple_assign_lhs (new_stmt))) | |
994 | { | |
995 | laststore = new_stmt; | |
996 | } | |
cbdd87d4 RG |
997 | last = new_stmt; |
998 | } | |
999 | ||
1000 | if (lhs == NULL_TREE) | |
1001 | { | |
fe2ef088 MM |
1002 | /* If we replace a call without LHS that has a VDEF and our new |
1003 | sequence ends with a store we must make that store have the same | |
1004 | vdef in order not to break the sequencing. This can happen | |
1005 | for instance when folding memcpy calls into assignments. */ | |
1006 | if (gimple_vdef (stmt) && laststore) | |
1007 | { | |
1008 | gimple_set_vdef (laststore, gimple_vdef (stmt)); | |
8a1561bc MM |
1009 | if (TREE_CODE (gimple_vdef (stmt)) == SSA_NAME) |
1010 | SSA_NAME_DEF_STMT (gimple_vdef (stmt)) = laststore; | |
fe2ef088 MM |
1011 | update_stmt (laststore); |
1012 | } | |
edc74207 | 1013 | else if (gimple_in_ssa_p (cfun)) |
fe2ef088 MM |
1014 | { |
1015 | unlink_stmt_vdef (stmt); | |
1016 | release_defs (stmt); | |
1017 | } | |
cbdd87d4 RG |
1018 | new_stmt = last; |
1019 | } | |
1020 | else | |
1021 | { | |
1022 | if (last) | |
1023 | { | |
1024 | gsi_insert_before (si_p, last, GSI_NEW_STMT); | |
1025 | gsi_next (si_p); | |
1026 | } | |
8a1561bc MM |
1027 | if (laststore && is_gimple_reg (lhs)) |
1028 | { | |
1029 | gimple_set_vdef (laststore, gimple_vdef (stmt)); | |
1030 | update_stmt (laststore); | |
1031 | if (TREE_CODE (gimple_vdef (stmt)) == SSA_NAME) | |
1032 | SSA_NAME_DEF_STMT (gimple_vdef (stmt)) = laststore; | |
1033 | laststore = NULL; | |
1034 | } | |
1035 | else if (laststore) | |
fe2ef088 MM |
1036 | { |
1037 | reaching_vuse = make_ssa_name (gimple_vop (cfun), laststore); | |
1038 | gimple_set_vdef (laststore, reaching_vuse); | |
1039 | update_stmt (laststore); | |
1040 | laststore = NULL; | |
1041 | } | |
cbdd87d4 | 1042 | new_stmt = gimple_build_assign (lhs, tmp); |
8a1561bc MM |
1043 | if (!is_gimple_reg (tmp)) |
1044 | gimple_set_vuse (new_stmt, reaching_vuse); | |
1045 | if (!is_gimple_reg (lhs)) | |
1046 | { | |
1047 | gimple_set_vdef (new_stmt, gimple_vdef (stmt)); | |
1048 | if (TREE_CODE (gimple_vdef (stmt)) == SSA_NAME) | |
1049 | SSA_NAME_DEF_STMT (gimple_vdef (stmt)) = new_stmt; | |
1050 | } | |
07db7d35 RG |
1051 | else if (reaching_vuse == gimple_vuse (stmt)) |
1052 | unlink_stmt_vdef (stmt); | |
cbdd87d4 RG |
1053 | } |
1054 | ||
1055 | gimple_set_location (new_stmt, gimple_location (stmt)); | |
1056 | gsi_replace (si_p, new_stmt, false); | |
1057 | } | |
1058 | ||
1059 | /* Return the string length, maximum string length or maximum value of | |
1060 | ARG in LENGTH. | |
1061 | If ARG is an SSA name variable, follow its use-def chains. If LENGTH | |
1062 | is not NULL and, for TYPE == 0, its value is not equal to the length | |
1063 | we determine or if we are unable to determine the length or value, | |
1064 | return false. VISITED is a bitmap of visited variables. | |
1065 | TYPE is 0 if string length should be returned, 1 for maximum string | |
1066 | length and 2 for maximum value ARG can have. */ | |
1067 | ||
1068 | static bool | |
1069 | get_maxval_strlen (tree arg, tree *length, bitmap visited, int type) | |
1070 | { | |
1071 | tree var, val; | |
1072 | gimple def_stmt; | |
1073 | ||
1074 | if (TREE_CODE (arg) != SSA_NAME) | |
1075 | { | |
1076 | if (TREE_CODE (arg) == COND_EXPR) | |
1077 | return get_maxval_strlen (COND_EXPR_THEN (arg), length, visited, type) | |
1078 | && get_maxval_strlen (COND_EXPR_ELSE (arg), length, visited, type); | |
1079 | /* We can end up with &(*iftmp_1)[0] here as well, so handle it. */ | |
1080 | else if (TREE_CODE (arg) == ADDR_EXPR | |
1081 | && TREE_CODE (TREE_OPERAND (arg, 0)) == ARRAY_REF | |
1082 | && integer_zerop (TREE_OPERAND (TREE_OPERAND (arg, 0), 1))) | |
1083 | { | |
1084 | tree aop0 = TREE_OPERAND (TREE_OPERAND (arg, 0), 0); | |
1085 | if (TREE_CODE (aop0) == INDIRECT_REF | |
1086 | && TREE_CODE (TREE_OPERAND (aop0, 0)) == SSA_NAME) | |
1087 | return get_maxval_strlen (TREE_OPERAND (aop0, 0), | |
1088 | length, visited, type); | |
1089 | } | |
1090 | ||
1091 | if (type == 2) | |
1092 | { | |
1093 | val = arg; | |
1094 | if (TREE_CODE (val) != INTEGER_CST | |
1095 | || tree_int_cst_sgn (val) < 0) | |
1096 | return false; | |
1097 | } | |
1098 | else | |
1099 | val = c_strlen (arg, 1); | |
1100 | if (!val) | |
1101 | return false; | |
1102 | ||
1103 | if (*length) | |
1104 | { | |
1105 | if (type > 0) | |
1106 | { | |
1107 | if (TREE_CODE (*length) != INTEGER_CST | |
1108 | || TREE_CODE (val) != INTEGER_CST) | |
1109 | return false; | |
1110 | ||
1111 | if (tree_int_cst_lt (*length, val)) | |
1112 | *length = val; | |
1113 | return true; | |
1114 | } | |
1115 | else if (simple_cst_equal (val, *length) != 1) | |
1116 | return false; | |
1117 | } | |
1118 | ||
1119 | *length = val; | |
1120 | return true; | |
1121 | } | |
1122 | ||
1123 | /* If we were already here, break the infinite cycle. */ | |
fcaa4ca4 | 1124 | if (!bitmap_set_bit (visited, SSA_NAME_VERSION (arg))) |
cbdd87d4 | 1125 | return true; |
cbdd87d4 RG |
1126 | |
1127 | var = arg; | |
1128 | def_stmt = SSA_NAME_DEF_STMT (var); | |
1129 | ||
1130 | switch (gimple_code (def_stmt)) | |
1131 | { | |
1132 | case GIMPLE_ASSIGN: | |
1133 | /* The RHS of the statement defining VAR must either have a | |
1134 | constant length or come from another SSA_NAME with a constant | |
1135 | length. */ | |
1136 | if (gimple_assign_single_p (def_stmt) | |
1137 | || gimple_assign_unary_nop_p (def_stmt)) | |
1138 | { | |
1139 | tree rhs = gimple_assign_rhs1 (def_stmt); | |
1140 | return get_maxval_strlen (rhs, length, visited, type); | |
1141 | } | |
1142 | return false; | |
1143 | ||
1144 | case GIMPLE_PHI: | |
1145 | { | |
1146 | /* All the arguments of the PHI node must have the same constant | |
1147 | length. */ | |
1148 | unsigned i; | |
1149 | ||
1150 | for (i = 0; i < gimple_phi_num_args (def_stmt); i++) | |
1151 | { | |
1152 | tree arg = gimple_phi_arg (def_stmt, i)->def; | |
1153 | ||
1154 | /* If this PHI has itself as an argument, we cannot | |
1155 | determine the string length of this argument. However, | |
1156 | if we can find a constant string length for the other | |
1157 | PHI args then we can still be sure that this is a | |
1158 | constant string length. So be optimistic and just | |
1159 | continue with the next argument. */ | |
1160 | if (arg == gimple_phi_result (def_stmt)) | |
1161 | continue; | |
1162 | ||
1163 | if (!get_maxval_strlen (arg, length, visited, type)) | |
1164 | return false; | |
1165 | } | |
1166 | } | |
1167 | return true; | |
1168 | ||
1169 | default: | |
1170 | return false; | |
1171 | } | |
1172 | } | |
1173 | ||
1174 | ||
1175 | /* Fold builtin call in statement STMT. Returns a simplified tree. | |
1176 | We may return a non-constant expression, including another call | |
1177 | to a different function and with different arguments, e.g., | |
1178 | substituting memcpy for strcpy when the string length is known. | |
1179 | Note that some builtins expand into inline code that may not | |
1180 | be valid in GIMPLE. Callers must take care. */ | |
1181 | ||
1182 | tree | |
1183 | gimple_fold_builtin (gimple stmt) | |
1184 | { | |
1185 | tree result, val[3]; | |
1186 | tree callee, a; | |
1187 | int arg_idx, type; | |
1188 | bitmap visited; | |
1189 | bool ignore; | |
1190 | int nargs; | |
1191 | location_t loc = gimple_location (stmt); | |
1192 | ||
1193 | gcc_assert (is_gimple_call (stmt)); | |
1194 | ||
1195 | ignore = (gimple_call_lhs (stmt) == NULL); | |
1196 | ||
1197 | /* First try the generic builtin folder. If that succeeds, return the | |
1198 | result directly. */ | |
1199 | result = fold_call_stmt (stmt, ignore); | |
1200 | if (result) | |
1201 | { | |
1202 | if (ignore) | |
1203 | STRIP_NOPS (result); | |
1204 | return result; | |
1205 | } | |
1206 | ||
1207 | /* Ignore MD builtins. */ | |
1208 | callee = gimple_call_fndecl (stmt); | |
1209 | if (DECL_BUILT_IN_CLASS (callee) == BUILT_IN_MD) | |
1210 | return NULL_TREE; | |
1211 | ||
1212 | /* If the builtin could not be folded, and it has no argument list, | |
1213 | we're done. */ | |
1214 | nargs = gimple_call_num_args (stmt); | |
1215 | if (nargs == 0) | |
1216 | return NULL_TREE; | |
1217 | ||
1218 | /* Limit the work only for builtins we know how to simplify. */ | |
1219 | switch (DECL_FUNCTION_CODE (callee)) | |
1220 | { | |
1221 | case BUILT_IN_STRLEN: | |
1222 | case BUILT_IN_FPUTS: | |
1223 | case BUILT_IN_FPUTS_UNLOCKED: | |
1224 | arg_idx = 0; | |
1225 | type = 0; | |
1226 | break; | |
1227 | case BUILT_IN_STRCPY: | |
1228 | case BUILT_IN_STRNCPY: | |
1229 | arg_idx = 1; | |
1230 | type = 0; | |
1231 | break; | |
1232 | case BUILT_IN_MEMCPY_CHK: | |
1233 | case BUILT_IN_MEMPCPY_CHK: | |
1234 | case BUILT_IN_MEMMOVE_CHK: | |
1235 | case BUILT_IN_MEMSET_CHK: | |
1236 | case BUILT_IN_STRNCPY_CHK: | |
1237 | arg_idx = 2; | |
1238 | type = 2; | |
1239 | break; | |
1240 | case BUILT_IN_STRCPY_CHK: | |
1241 | case BUILT_IN_STPCPY_CHK: | |
1242 | arg_idx = 1; | |
1243 | type = 1; | |
1244 | break; | |
1245 | case BUILT_IN_SNPRINTF_CHK: | |
1246 | case BUILT_IN_VSNPRINTF_CHK: | |
1247 | arg_idx = 1; | |
1248 | type = 2; | |
1249 | break; | |
1250 | default: | |
1251 | return NULL_TREE; | |
1252 | } | |
1253 | ||
1254 | if (arg_idx >= nargs) | |
1255 | return NULL_TREE; | |
1256 | ||
1257 | /* Try to use the dataflow information gathered by the CCP process. */ | |
1258 | visited = BITMAP_ALLOC (NULL); | |
1259 | bitmap_clear (visited); | |
1260 | ||
1261 | memset (val, 0, sizeof (val)); | |
1262 | a = gimple_call_arg (stmt, arg_idx); | |
1263 | if (!get_maxval_strlen (a, &val[arg_idx], visited, type)) | |
1264 | val[arg_idx] = NULL_TREE; | |
1265 | ||
1266 | BITMAP_FREE (visited); | |
1267 | ||
1268 | result = NULL_TREE; | |
1269 | switch (DECL_FUNCTION_CODE (callee)) | |
1270 | { | |
1271 | case BUILT_IN_STRLEN: | |
1272 | if (val[0] && nargs == 1) | |
1273 | { | |
1274 | tree new_val = | |
1275 | fold_convert (TREE_TYPE (gimple_call_lhs (stmt)), val[0]); | |
1276 | ||
1277 | /* If the result is not a valid gimple value, or not a cast | |
6e4da084 | 1278 | of a valid gimple value, then we cannot use the result. */ |
cbdd87d4 | 1279 | if (is_gimple_val (new_val) |
3dbe9454 | 1280 | || (CONVERT_EXPR_P (new_val) |
cbdd87d4 RG |
1281 | && is_gimple_val (TREE_OPERAND (new_val, 0)))) |
1282 | return new_val; | |
1283 | } | |
1284 | break; | |
1285 | ||
1286 | case BUILT_IN_STRCPY: | |
1287 | if (val[1] && is_gimple_val (val[1]) && nargs == 2) | |
1288 | result = fold_builtin_strcpy (loc, callee, | |
1289 | gimple_call_arg (stmt, 0), | |
1290 | gimple_call_arg (stmt, 1), | |
1291 | val[1]); | |
1292 | break; | |
1293 | ||
1294 | case BUILT_IN_STRNCPY: | |
1295 | if (val[1] && is_gimple_val (val[1]) && nargs == 3) | |
1296 | result = fold_builtin_strncpy (loc, callee, | |
1297 | gimple_call_arg (stmt, 0), | |
1298 | gimple_call_arg (stmt, 1), | |
1299 | gimple_call_arg (stmt, 2), | |
1300 | val[1]); | |
1301 | break; | |
1302 | ||
1303 | case BUILT_IN_FPUTS: | |
1304 | if (nargs == 2) | |
1305 | result = fold_builtin_fputs (loc, gimple_call_arg (stmt, 0), | |
1306 | gimple_call_arg (stmt, 1), | |
1307 | ignore, false, val[0]); | |
1308 | break; | |
1309 | ||
1310 | case BUILT_IN_FPUTS_UNLOCKED: | |
1311 | if (nargs == 2) | |
1312 | result = fold_builtin_fputs (loc, gimple_call_arg (stmt, 0), | |
1313 | gimple_call_arg (stmt, 1), | |
1314 | ignore, true, val[0]); | |
1315 | break; | |
1316 | ||
1317 | case BUILT_IN_MEMCPY_CHK: | |
1318 | case BUILT_IN_MEMPCPY_CHK: | |
1319 | case BUILT_IN_MEMMOVE_CHK: | |
1320 | case BUILT_IN_MEMSET_CHK: | |
1321 | if (val[2] && is_gimple_val (val[2]) && nargs == 4) | |
1322 | result = fold_builtin_memory_chk (loc, callee, | |
1323 | gimple_call_arg (stmt, 0), | |
1324 | gimple_call_arg (stmt, 1), | |
1325 | gimple_call_arg (stmt, 2), | |
1326 | gimple_call_arg (stmt, 3), | |
1327 | val[2], ignore, | |
1328 | DECL_FUNCTION_CODE (callee)); | |
1329 | break; | |
1330 | ||
1331 | case BUILT_IN_STRCPY_CHK: | |
1332 | case BUILT_IN_STPCPY_CHK: | |
1333 | if (val[1] && is_gimple_val (val[1]) && nargs == 3) | |
1334 | result = fold_builtin_stxcpy_chk (loc, callee, | |
1335 | gimple_call_arg (stmt, 0), | |
1336 | gimple_call_arg (stmt, 1), | |
1337 | gimple_call_arg (stmt, 2), | |
1338 | val[1], ignore, | |
1339 | DECL_FUNCTION_CODE (callee)); | |
1340 | break; | |
1341 | ||
1342 | case BUILT_IN_STRNCPY_CHK: | |
1343 | if (val[2] && is_gimple_val (val[2]) && nargs == 4) | |
1344 | result = fold_builtin_strncpy_chk (loc, gimple_call_arg (stmt, 0), | |
1345 | gimple_call_arg (stmt, 1), | |
1346 | gimple_call_arg (stmt, 2), | |
1347 | gimple_call_arg (stmt, 3), | |
1348 | val[2]); | |
1349 | break; | |
1350 | ||
1351 | case BUILT_IN_SNPRINTF_CHK: | |
1352 | case BUILT_IN_VSNPRINTF_CHK: | |
1353 | if (val[1] && is_gimple_val (val[1])) | |
1354 | result = gimple_fold_builtin_snprintf_chk (stmt, val[1], | |
1355 | DECL_FUNCTION_CODE (callee)); | |
1356 | break; | |
1357 | ||
1358 | default: | |
1359 | gcc_unreachable (); | |
1360 | } | |
1361 | ||
1362 | if (result && ignore) | |
1363 | result = fold_ignored_result (result); | |
1364 | return result; | |
1365 | } | |
1366 | ||
1ae6fe9b MJ |
1367 | /* Search for a base binfo of BINFO that corresponds to TYPE and return it if |
1368 | it is found or NULL_TREE if it is not. */ | |
1369 | ||
1370 | static tree | |
1371 | get_base_binfo_for_type (tree binfo, tree type) | |
1372 | { | |
1373 | int i; | |
1374 | tree base_binfo; | |
1375 | tree res = NULL_TREE; | |
1376 | ||
1377 | for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) | |
1378 | if (TREE_TYPE (base_binfo) == type) | |
1379 | { | |
1380 | gcc_assert (!res); | |
1381 | res = base_binfo; | |
1382 | } | |
1383 | ||
1384 | return res; | |
1385 | } | |
1386 | ||
1387 | /* Return a binfo describing the part of object referenced by expression REF. | |
1388 | Return NULL_TREE if it cannot be determined. REF can consist of a series of | |
1389 | COMPONENT_REFs of a declaration or of an INDIRECT_REF or it can also be just | |
1390 | a simple declaration, indirect reference or an SSA_NAME. If the function | |
1391 | discovers an INDIRECT_REF or an SSA_NAME, it will assume that the | |
1392 | encapsulating type is described by KNOWN_BINFO, if it is not NULL_TREE. | |
1393 | Otherwise the first non-artificial field declaration or the base declaration | |
1394 | will be examined to get the encapsulating type. */ | |
1395 | ||
1396 | tree | |
1397 | gimple_get_relevant_ref_binfo (tree ref, tree known_binfo) | |
1398 | { | |
1399 | while (true) | |
1400 | { | |
1401 | if (TREE_CODE (ref) == COMPONENT_REF) | |
1402 | { | |
1403 | tree par_type; | |
b85020cb | 1404 | tree binfo; |
1ae6fe9b MJ |
1405 | tree field = TREE_OPERAND (ref, 1); |
1406 | ||
1407 | if (!DECL_ARTIFICIAL (field)) | |
1408 | { | |
1409 | tree type = TREE_TYPE (field); | |
1410 | if (TREE_CODE (type) == RECORD_TYPE) | |
1411 | return TYPE_BINFO (type); | |
1412 | else | |
1413 | return NULL_TREE; | |
1414 | } | |
1415 | ||
1416 | par_type = TREE_TYPE (TREE_OPERAND (ref, 0)); | |
1417 | binfo = TYPE_BINFO (par_type); | |
1418 | if (!binfo | |
1419 | || BINFO_N_BASE_BINFOS (binfo) == 0) | |
1420 | return NULL_TREE; | |
1421 | ||
b85020cb MJ |
1422 | /* Offset 0 indicates the primary base, whose vtable contents are |
1423 | represented in the binfo for the derived class. */ | |
1424 | if (int_bit_position (field) != 0) | |
1ae6fe9b MJ |
1425 | { |
1426 | tree d_binfo; | |
1427 | ||
b85020cb | 1428 | /* Get descendant binfo. */ |
1ae6fe9b MJ |
1429 | d_binfo = gimple_get_relevant_ref_binfo (TREE_OPERAND (ref, 0), |
1430 | known_binfo); | |
1ae6fe9b MJ |
1431 | if (!d_binfo) |
1432 | return NULL_TREE; | |
1433 | return get_base_binfo_for_type (d_binfo, TREE_TYPE (field)); | |
1434 | } | |
1435 | ||
1436 | ref = TREE_OPERAND (ref, 0); | |
1437 | } | |
1438 | else if (DECL_P (ref) && TREE_CODE (TREE_TYPE (ref)) == RECORD_TYPE) | |
1439 | return TYPE_BINFO (TREE_TYPE (ref)); | |
1440 | else if (known_binfo | |
1441 | && (TREE_CODE (ref) == SSA_NAME | |
70f34814 | 1442 | || TREE_CODE (ref) == MEM_REF)) |
1ae6fe9b MJ |
1443 | return known_binfo; |
1444 | else | |
1445 | return NULL_TREE; | |
1446 | } | |
1447 | } | |
1448 | ||
1449 | /* Fold a OBJ_TYPE_REF expression to the address of a function. TOKEN is | |
1450 | integer form of OBJ_TYPE_REF_TOKEN of the reference expression. KNOWN_BINFO | |
1451 | carries the binfo describing the true type of OBJ_TYPE_REF_OBJECT(REF). */ | |
1452 | ||
1453 | tree | |
1454 | gimple_fold_obj_type_ref_known_binfo (HOST_WIDE_INT token, tree known_binfo) | |
1455 | { | |
1456 | HOST_WIDE_INT i; | |
3f1f0ae3 | 1457 | tree v, fndecl, delta; |
1ae6fe9b MJ |
1458 | |
1459 | v = BINFO_VIRTUALS (known_binfo); | |
1460 | i = 0; | |
1461 | while (i != token) | |
1462 | { | |
1463 | i += (TARGET_VTABLE_USES_DESCRIPTORS | |
1464 | ? TARGET_VTABLE_USES_DESCRIPTORS : 1); | |
1465 | v = TREE_CHAIN (v); | |
1466 | } | |
1467 | ||
1468 | fndecl = TREE_VALUE (v); | |
3f1f0ae3 MJ |
1469 | delta = TREE_PURPOSE (v); |
1470 | gcc_assert (host_integerp (delta, 0)); | |
1471 | ||
1472 | if (integer_nonzerop (delta)) | |
1473 | { | |
1474 | struct cgraph_node *node = cgraph_get_node (fndecl); | |
1475 | HOST_WIDE_INT off = tree_low_cst (delta, 0); | |
1476 | ||
1477 | if (!node) | |
1478 | return NULL; | |
1479 | for (node = node->same_body; node; node = node->next) | |
1480 | if (node->thunk.thunk_p && off == node->thunk.fixed_offset) | |
1481 | break; | |
1482 | if (node) | |
1483 | fndecl = node->decl; | |
1484 | else | |
1485 | return NULL; | |
1486 | } | |
1487 | ||
6e4da084 JH |
1488 | /* When cgraph node is missing and function is not public, we cannot |
1489 | devirtualize. This can happen in WHOPR when the actual method | |
1490 | ends up in other partition, because we found devirtualization | |
1491 | possibility too late. */ | |
b3b9f3d0 | 1492 | if (!can_refer_decl_in_current_unit_p (fndecl)) |
6e4da084 | 1493 | return NULL; |
1ae6fe9b MJ |
1494 | return build_fold_addr_expr (fndecl); |
1495 | } | |
1496 | ||
1497 | ||
1498 | /* Fold a OBJ_TYPE_REF expression to the address of a function. If KNOWN_TYPE | |
1499 | is not NULL_TREE, it is the true type of the outmost encapsulating object if | |
1500 | that comes from a pointer SSA_NAME. If the true outmost encapsulating type | |
1501 | can be determined from a declaration OBJ_TYPE_REF_OBJECT(REF), it is used | |
1502 | regardless of KNOWN_TYPE (which thus can be NULL_TREE). */ | |
1503 | ||
1504 | tree | |
1505 | gimple_fold_obj_type_ref (tree ref, tree known_type) | |
1506 | { | |
1507 | tree obj = OBJ_TYPE_REF_OBJECT (ref); | |
1508 | tree known_binfo = known_type ? TYPE_BINFO (known_type) : NULL_TREE; | |
1509 | tree binfo; | |
1510 | ||
1511 | if (TREE_CODE (obj) == ADDR_EXPR) | |
1512 | obj = TREE_OPERAND (obj, 0); | |
1513 | ||
1514 | binfo = gimple_get_relevant_ref_binfo (obj, known_binfo); | |
1515 | if (binfo) | |
1516 | { | |
1517 | HOST_WIDE_INT token = tree_low_cst (OBJ_TYPE_REF_TOKEN (ref), 1); | |
0d8485e0 | 1518 | /* If there is no virtual methods leave the OBJ_TYPE_REF alone. */ |
ce2b1d68 | 1519 | if (!BINFO_VIRTUALS (binfo)) |
0d8485e0 | 1520 | return NULL_TREE; |
1ae6fe9b MJ |
1521 | return gimple_fold_obj_type_ref_known_binfo (token, binfo); |
1522 | } | |
1523 | else | |
1524 | return NULL_TREE; | |
1525 | } | |
1526 | ||
cbdd87d4 RG |
1527 | /* Attempt to fold a call statement referenced by the statement iterator GSI. |
1528 | The statement may be replaced by another statement, e.g., if the call | |
1529 | simplifies to a constant value. Return true if any changes were made. | |
1530 | It is assumed that the operands have been previously folded. */ | |
1531 | ||
1532 | static bool | |
23c1da7a | 1533 | fold_gimple_call (gimple_stmt_iterator *gsi, bool inplace) |
cbdd87d4 RG |
1534 | { |
1535 | gimple stmt = gsi_stmt (*gsi); | |
1536 | ||
1537 | tree callee = gimple_call_fndecl (stmt); | |
1538 | ||
1539 | /* Check for builtins that CCP can handle using information not | |
1540 | available in the generic fold routines. */ | |
23c1da7a | 1541 | if (!inplace && callee && DECL_BUILT_IN (callee)) |
cbdd87d4 RG |
1542 | { |
1543 | tree result = gimple_fold_builtin (stmt); | |
1544 | ||
1545 | if (result) | |
1546 | { | |
1547 | if (!update_call_from_tree (gsi, result)) | |
1548 | gimplify_and_update_call_from_tree (gsi, result); | |
1549 | return true; | |
1550 | } | |
1551 | } | |
1552 | else | |
1553 | { | |
cbdd87d4 RG |
1554 | /* ??? Should perhaps do this in fold proper. However, doing it |
1555 | there requires that we create a new CALL_EXPR, and that requires | |
1556 | copying EH region info to the new node. Easier to just do it | |
1557 | here where we can just smash the call operand. */ | |
cbdd87d4 RG |
1558 | callee = gimple_call_fn (stmt); |
1559 | if (TREE_CODE (callee) == OBJ_TYPE_REF | |
1ae6fe9b | 1560 | && TREE_CODE (OBJ_TYPE_REF_OBJECT (callee)) == ADDR_EXPR) |
cbdd87d4 RG |
1561 | { |
1562 | tree t; | |
1563 | ||
1ae6fe9b | 1564 | t = gimple_fold_obj_type_ref (callee, NULL_TREE); |
cbdd87d4 RG |
1565 | if (t) |
1566 | { | |
1567 | gimple_call_set_fn (stmt, t); | |
1568 | return true; | |
1569 | } | |
1570 | } | |
1571 | } | |
1572 | ||
1573 | return false; | |
1574 | } | |
1575 | ||
1576 | /* Worker for both fold_stmt and fold_stmt_inplace. The INPLACE argument | |
1577 | distinguishes both cases. */ | |
1578 | ||
1579 | static bool | |
1580 | fold_stmt_1 (gimple_stmt_iterator *gsi, bool inplace) | |
1581 | { | |
1582 | bool changed = false; | |
1583 | gimple stmt = gsi_stmt (*gsi); | |
1584 | unsigned i; | |
1585 | ||
1586 | /* Fold the main computation performed by the statement. */ | |
1587 | switch (gimple_code (stmt)) | |
1588 | { | |
1589 | case GIMPLE_ASSIGN: | |
1590 | { | |
1591 | unsigned old_num_ops = gimple_num_ops (stmt); | |
1592 | tree new_rhs = fold_gimple_assign (gsi); | |
1593 | tree lhs = gimple_assign_lhs (stmt); | |
1594 | if (new_rhs | |
1595 | && !useless_type_conversion_p (TREE_TYPE (lhs), | |
1596 | TREE_TYPE (new_rhs))) | |
1597 | new_rhs = fold_convert (TREE_TYPE (lhs), new_rhs); | |
1598 | if (new_rhs | |
1599 | && (!inplace | |
1600 | || get_gimple_rhs_num_ops (TREE_CODE (new_rhs)) < old_num_ops)) | |
1601 | { | |
1602 | gimple_assign_set_rhs_from_tree (gsi, new_rhs); | |
1603 | changed = true; | |
1604 | } | |
1605 | break; | |
1606 | } | |
1607 | ||
1608 | case GIMPLE_COND: | |
1609 | changed |= fold_gimple_cond (stmt); | |
1610 | break; | |
1611 | ||
1612 | case GIMPLE_CALL: | |
1613 | /* Fold *& in call arguments. */ | |
1614 | for (i = 0; i < gimple_call_num_args (stmt); ++i) | |
1615 | if (REFERENCE_CLASS_P (gimple_call_arg (stmt, i))) | |
1616 | { | |
1617 | tree tmp = maybe_fold_reference (gimple_call_arg (stmt, i), false); | |
1618 | if (tmp) | |
1619 | { | |
1620 | gimple_call_set_arg (stmt, i, tmp); | |
1621 | changed = true; | |
1622 | } | |
1623 | } | |
23c1da7a | 1624 | changed |= fold_gimple_call (gsi, inplace); |
cbdd87d4 RG |
1625 | break; |
1626 | ||
1627 | case GIMPLE_ASM: | |
1628 | /* Fold *& in asm operands. */ | |
1629 | for (i = 0; i < gimple_asm_noutputs (stmt); ++i) | |
1630 | { | |
1631 | tree link = gimple_asm_output_op (stmt, i); | |
1632 | tree op = TREE_VALUE (link); | |
1633 | if (REFERENCE_CLASS_P (op) | |
1634 | && (op = maybe_fold_reference (op, true)) != NULL_TREE) | |
1635 | { | |
1636 | TREE_VALUE (link) = op; | |
1637 | changed = true; | |
1638 | } | |
1639 | } | |
1640 | for (i = 0; i < gimple_asm_ninputs (stmt); ++i) | |
1641 | { | |
1642 | tree link = gimple_asm_input_op (stmt, i); | |
1643 | tree op = TREE_VALUE (link); | |
1644 | if (REFERENCE_CLASS_P (op) | |
1645 | && (op = maybe_fold_reference (op, false)) != NULL_TREE) | |
1646 | { | |
1647 | TREE_VALUE (link) = op; | |
1648 | changed = true; | |
1649 | } | |
1650 | } | |
1651 | break; | |
1652 | ||
bd422c4a RG |
1653 | case GIMPLE_DEBUG: |
1654 | if (gimple_debug_bind_p (stmt)) | |
1655 | { | |
1656 | tree val = gimple_debug_bind_get_value (stmt); | |
1657 | if (val | |
1658 | && REFERENCE_CLASS_P (val)) | |
1659 | { | |
1660 | tree tem = maybe_fold_reference (val, false); | |
1661 | if (tem) | |
1662 | { | |
1663 | gimple_debug_bind_set_value (stmt, tem); | |
1664 | changed = true; | |
1665 | } | |
1666 | } | |
1667 | } | |
1668 | break; | |
1669 | ||
cbdd87d4 RG |
1670 | default:; |
1671 | } | |
1672 | ||
1673 | stmt = gsi_stmt (*gsi); | |
1674 | ||
1675 | /* Fold *& on the lhs. */ | |
1676 | if (gimple_has_lhs (stmt)) | |
1677 | { | |
1678 | tree lhs = gimple_get_lhs (stmt); | |
1679 | if (lhs && REFERENCE_CLASS_P (lhs)) | |
1680 | { | |
1681 | tree new_lhs = maybe_fold_reference (lhs, true); | |
1682 | if (new_lhs) | |
1683 | { | |
1684 | gimple_set_lhs (stmt, new_lhs); | |
1685 | changed = true; | |
1686 | } | |
1687 | } | |
1688 | } | |
1689 | ||
1690 | return changed; | |
1691 | } | |
1692 | ||
1693 | /* Fold the statement pointed to by GSI. In some cases, this function may | |
1694 | replace the whole statement with a new one. Returns true iff folding | |
1695 | makes any changes. | |
1696 | The statement pointed to by GSI should be in valid gimple form but may | |
1697 | be in unfolded state as resulting from for example constant propagation | |
1698 | which can produce *&x = 0. */ | |
1699 | ||
1700 | bool | |
1701 | fold_stmt (gimple_stmt_iterator *gsi) | |
1702 | { | |
1703 | return fold_stmt_1 (gsi, false); | |
1704 | } | |
1705 | ||
1706 | /* Perform the minimal folding on statement STMT. Only operations like | |
1707 | *&x created by constant propagation are handled. The statement cannot | |
1708 | be replaced with a new one. Return true if the statement was | |
1709 | changed, false otherwise. | |
1710 | The statement STMT should be in valid gimple form but may | |
1711 | be in unfolded state as resulting from for example constant propagation | |
1712 | which can produce *&x = 0. */ | |
1713 | ||
1714 | bool | |
1715 | fold_stmt_inplace (gimple stmt) | |
1716 | { | |
1717 | gimple_stmt_iterator gsi = gsi_for_stmt (stmt); | |
1718 | bool changed = fold_stmt_1 (&gsi, true); | |
1719 | gcc_assert (gsi_stmt (gsi) == stmt); | |
1720 | return changed; | |
1721 | } | |
1722 | ||
e89065a1 SL |
1723 | /* Canonicalize and possibly invert the boolean EXPR; return NULL_TREE |
1724 | if EXPR is null or we don't know how. | |
1725 | If non-null, the result always has boolean type. */ | |
1726 | ||
1727 | static tree | |
1728 | canonicalize_bool (tree expr, bool invert) | |
1729 | { | |
1730 | if (!expr) | |
1731 | return NULL_TREE; | |
1732 | else if (invert) | |
1733 | { | |
1734 | if (integer_nonzerop (expr)) | |
1735 | return boolean_false_node; | |
1736 | else if (integer_zerop (expr)) | |
1737 | return boolean_true_node; | |
1738 | else if (TREE_CODE (expr) == SSA_NAME) | |
1739 | return fold_build2 (EQ_EXPR, boolean_type_node, expr, | |
1740 | build_int_cst (TREE_TYPE (expr), 0)); | |
1741 | else if (TREE_CODE_CLASS (TREE_CODE (expr)) == tcc_comparison) | |
1742 | return fold_build2 (invert_tree_comparison (TREE_CODE (expr), false), | |
1743 | boolean_type_node, | |
1744 | TREE_OPERAND (expr, 0), | |
1745 | TREE_OPERAND (expr, 1)); | |
1746 | else | |
1747 | return NULL_TREE; | |
1748 | } | |
1749 | else | |
1750 | { | |
1751 | if (TREE_CODE (TREE_TYPE (expr)) == BOOLEAN_TYPE) | |
1752 | return expr; | |
1753 | if (integer_nonzerop (expr)) | |
1754 | return boolean_true_node; | |
1755 | else if (integer_zerop (expr)) | |
1756 | return boolean_false_node; | |
1757 | else if (TREE_CODE (expr) == SSA_NAME) | |
1758 | return fold_build2 (NE_EXPR, boolean_type_node, expr, | |
1759 | build_int_cst (TREE_TYPE (expr), 0)); | |
1760 | else if (TREE_CODE_CLASS (TREE_CODE (expr)) == tcc_comparison) | |
1761 | return fold_build2 (TREE_CODE (expr), | |
1762 | boolean_type_node, | |
1763 | TREE_OPERAND (expr, 0), | |
1764 | TREE_OPERAND (expr, 1)); | |
1765 | else | |
1766 | return NULL_TREE; | |
1767 | } | |
1768 | } | |
1769 | ||
1770 | /* Check to see if a boolean expression EXPR is logically equivalent to the | |
1771 | comparison (OP1 CODE OP2). Check for various identities involving | |
1772 | SSA_NAMEs. */ | |
1773 | ||
1774 | static bool | |
1775 | same_bool_comparison_p (const_tree expr, enum tree_code code, | |
1776 | const_tree op1, const_tree op2) | |
1777 | { | |
1778 | gimple s; | |
1779 | ||
1780 | /* The obvious case. */ | |
1781 | if (TREE_CODE (expr) == code | |
1782 | && operand_equal_p (TREE_OPERAND (expr, 0), op1, 0) | |
1783 | && operand_equal_p (TREE_OPERAND (expr, 1), op2, 0)) | |
1784 | return true; | |
1785 | ||
1786 | /* Check for comparing (name, name != 0) and the case where expr | |
1787 | is an SSA_NAME with a definition matching the comparison. */ | |
1788 | if (TREE_CODE (expr) == SSA_NAME | |
1789 | && TREE_CODE (TREE_TYPE (expr)) == BOOLEAN_TYPE) | |
1790 | { | |
1791 | if (operand_equal_p (expr, op1, 0)) | |
1792 | return ((code == NE_EXPR && integer_zerop (op2)) | |
1793 | || (code == EQ_EXPR && integer_nonzerop (op2))); | |
1794 | s = SSA_NAME_DEF_STMT (expr); | |
1795 | if (is_gimple_assign (s) | |
1796 | && gimple_assign_rhs_code (s) == code | |
1797 | && operand_equal_p (gimple_assign_rhs1 (s), op1, 0) | |
1798 | && operand_equal_p (gimple_assign_rhs2 (s), op2, 0)) | |
1799 | return true; | |
1800 | } | |
1801 | ||
1802 | /* If op1 is of the form (name != 0) or (name == 0), and the definition | |
1803 | of name is a comparison, recurse. */ | |
1804 | if (TREE_CODE (op1) == SSA_NAME | |
1805 | && TREE_CODE (TREE_TYPE (op1)) == BOOLEAN_TYPE) | |
1806 | { | |
1807 | s = SSA_NAME_DEF_STMT (op1); | |
1808 | if (is_gimple_assign (s) | |
1809 | && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison) | |
1810 | { | |
1811 | enum tree_code c = gimple_assign_rhs_code (s); | |
1812 | if ((c == NE_EXPR && integer_zerop (op2)) | |
1813 | || (c == EQ_EXPR && integer_nonzerop (op2))) | |
1814 | return same_bool_comparison_p (expr, c, | |
1815 | gimple_assign_rhs1 (s), | |
1816 | gimple_assign_rhs2 (s)); | |
1817 | if ((c == EQ_EXPR && integer_zerop (op2)) | |
1818 | || (c == NE_EXPR && integer_nonzerop (op2))) | |
1819 | return same_bool_comparison_p (expr, | |
1820 | invert_tree_comparison (c, false), | |
1821 | gimple_assign_rhs1 (s), | |
1822 | gimple_assign_rhs2 (s)); | |
1823 | } | |
1824 | } | |
1825 | return false; | |
1826 | } | |
1827 | ||
1828 | /* Check to see if two boolean expressions OP1 and OP2 are logically | |
1829 | equivalent. */ | |
1830 | ||
1831 | static bool | |
1832 | same_bool_result_p (const_tree op1, const_tree op2) | |
1833 | { | |
1834 | /* Simple cases first. */ | |
1835 | if (operand_equal_p (op1, op2, 0)) | |
1836 | return true; | |
1837 | ||
1838 | /* Check the cases where at least one of the operands is a comparison. | |
1839 | These are a bit smarter than operand_equal_p in that they apply some | |
1840 | identifies on SSA_NAMEs. */ | |
1841 | if (TREE_CODE_CLASS (TREE_CODE (op2)) == tcc_comparison | |
1842 | && same_bool_comparison_p (op1, TREE_CODE (op2), | |
1843 | TREE_OPERAND (op2, 0), | |
1844 | TREE_OPERAND (op2, 1))) | |
1845 | return true; | |
1846 | if (TREE_CODE_CLASS (TREE_CODE (op1)) == tcc_comparison | |
1847 | && same_bool_comparison_p (op2, TREE_CODE (op1), | |
1848 | TREE_OPERAND (op1, 0), | |
1849 | TREE_OPERAND (op1, 1))) | |
1850 | return true; | |
1851 | ||
1852 | /* Default case. */ | |
1853 | return false; | |
1854 | } | |
1855 | ||
1856 | /* Forward declarations for some mutually recursive functions. */ | |
1857 | ||
1858 | static tree | |
1859 | and_comparisons_1 (enum tree_code code1, tree op1a, tree op1b, | |
1860 | enum tree_code code2, tree op2a, tree op2b); | |
1861 | static tree | |
1862 | and_var_with_comparison (tree var, bool invert, | |
1863 | enum tree_code code2, tree op2a, tree op2b); | |
1864 | static tree | |
1865 | and_var_with_comparison_1 (gimple stmt, | |
1866 | enum tree_code code2, tree op2a, tree op2b); | |
1867 | static tree | |
1868 | or_comparisons_1 (enum tree_code code1, tree op1a, tree op1b, | |
1869 | enum tree_code code2, tree op2a, tree op2b); | |
1870 | static tree | |
1871 | or_var_with_comparison (tree var, bool invert, | |
1872 | enum tree_code code2, tree op2a, tree op2b); | |
1873 | static tree | |
1874 | or_var_with_comparison_1 (gimple stmt, | |
1875 | enum tree_code code2, tree op2a, tree op2b); | |
1876 | ||
1877 | /* Helper function for and_comparisons_1: try to simplify the AND of the | |
1878 | ssa variable VAR with the comparison specified by (OP2A CODE2 OP2B). | |
1879 | If INVERT is true, invert the value of the VAR before doing the AND. | |
1880 | Return NULL_EXPR if we can't simplify this to a single expression. */ | |
1881 | ||
1882 | static tree | |
1883 | and_var_with_comparison (tree var, bool invert, | |
1884 | enum tree_code code2, tree op2a, tree op2b) | |
1885 | { | |
1886 | tree t; | |
1887 | gimple stmt = SSA_NAME_DEF_STMT (var); | |
1888 | ||
1889 | /* We can only deal with variables whose definitions are assignments. */ | |
1890 | if (!is_gimple_assign (stmt)) | |
1891 | return NULL_TREE; | |
1892 | ||
1893 | /* If we have an inverted comparison, apply DeMorgan's law and rewrite | |
1894 | !var AND (op2a code2 op2b) => !(var OR !(op2a code2 op2b)) | |
1895 | Then we only have to consider the simpler non-inverted cases. */ | |
1896 | if (invert) | |
1897 | t = or_var_with_comparison_1 (stmt, | |
1898 | invert_tree_comparison (code2, false), | |
1899 | op2a, op2b); | |
1900 | else | |
1901 | t = and_var_with_comparison_1 (stmt, code2, op2a, op2b); | |
1902 | return canonicalize_bool (t, invert); | |
1903 | } | |
1904 | ||
1905 | /* Try to simplify the AND of the ssa variable defined by the assignment | |
1906 | STMT with the comparison specified by (OP2A CODE2 OP2B). | |
1907 | Return NULL_EXPR if we can't simplify this to a single expression. */ | |
1908 | ||
1909 | static tree | |
1910 | and_var_with_comparison_1 (gimple stmt, | |
1911 | enum tree_code code2, tree op2a, tree op2b) | |
1912 | { | |
1913 | tree var = gimple_assign_lhs (stmt); | |
1914 | tree true_test_var = NULL_TREE; | |
1915 | tree false_test_var = NULL_TREE; | |
1916 | enum tree_code innercode = gimple_assign_rhs_code (stmt); | |
1917 | ||
1918 | /* Check for identities like (var AND (var == 0)) => false. */ | |
1919 | if (TREE_CODE (op2a) == SSA_NAME | |
1920 | && TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE) | |
1921 | { | |
1922 | if ((code2 == NE_EXPR && integer_zerop (op2b)) | |
1923 | || (code2 == EQ_EXPR && integer_nonzerop (op2b))) | |
1924 | { | |
1925 | true_test_var = op2a; | |
1926 | if (var == true_test_var) | |
1927 | return var; | |
1928 | } | |
1929 | else if ((code2 == EQ_EXPR && integer_zerop (op2b)) | |
1930 | || (code2 == NE_EXPR && integer_nonzerop (op2b))) | |
1931 | { | |
1932 | false_test_var = op2a; | |
1933 | if (var == false_test_var) | |
1934 | return boolean_false_node; | |
1935 | } | |
1936 | } | |
1937 | ||
1938 | /* If the definition is a comparison, recurse on it. */ | |
1939 | if (TREE_CODE_CLASS (innercode) == tcc_comparison) | |
1940 | { | |
1941 | tree t = and_comparisons_1 (innercode, | |
1942 | gimple_assign_rhs1 (stmt), | |
1943 | gimple_assign_rhs2 (stmt), | |
1944 | code2, | |
1945 | op2a, | |
1946 | op2b); | |
1947 | if (t) | |
1948 | return t; | |
1949 | } | |
1950 | ||
1951 | /* If the definition is an AND or OR expression, we may be able to | |
1952 | simplify by reassociating. */ | |
1953 | if (innercode == TRUTH_AND_EXPR | |
1954 | || innercode == TRUTH_OR_EXPR | |
1955 | || (TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE | |
1956 | && (innercode == BIT_AND_EXPR || innercode == BIT_IOR_EXPR))) | |
1957 | { | |
1958 | tree inner1 = gimple_assign_rhs1 (stmt); | |
1959 | tree inner2 = gimple_assign_rhs2 (stmt); | |
1960 | gimple s; | |
1961 | tree t; | |
1962 | tree partial = NULL_TREE; | |
1963 | bool is_and = (innercode == TRUTH_AND_EXPR || innercode == BIT_AND_EXPR); | |
1964 | ||
1965 | /* Check for boolean identities that don't require recursive examination | |
1966 | of inner1/inner2: | |
1967 | inner1 AND (inner1 AND inner2) => inner1 AND inner2 => var | |
1968 | inner1 AND (inner1 OR inner2) => inner1 | |
1969 | !inner1 AND (inner1 AND inner2) => false | |
1970 | !inner1 AND (inner1 OR inner2) => !inner1 AND inner2 | |
1971 | Likewise for similar cases involving inner2. */ | |
1972 | if (inner1 == true_test_var) | |
1973 | return (is_and ? var : inner1); | |
1974 | else if (inner2 == true_test_var) | |
1975 | return (is_and ? var : inner2); | |
1976 | else if (inner1 == false_test_var) | |
1977 | return (is_and | |
1978 | ? boolean_false_node | |
1979 | : and_var_with_comparison (inner2, false, code2, op2a, op2b)); | |
1980 | else if (inner2 == false_test_var) | |
1981 | return (is_and | |
1982 | ? boolean_false_node | |
1983 | : and_var_with_comparison (inner1, false, code2, op2a, op2b)); | |
1984 | ||
1985 | /* Next, redistribute/reassociate the AND across the inner tests. | |
1986 | Compute the first partial result, (inner1 AND (op2a code op2b)) */ | |
1987 | if (TREE_CODE (inner1) == SSA_NAME | |
1988 | && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner1)) | |
1989 | && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison | |
1990 | && (t = maybe_fold_and_comparisons (gimple_assign_rhs_code (s), | |
1991 | gimple_assign_rhs1 (s), | |
1992 | gimple_assign_rhs2 (s), | |
1993 | code2, op2a, op2b))) | |
1994 | { | |
1995 | /* Handle the AND case, where we are reassociating: | |
1996 | (inner1 AND inner2) AND (op2a code2 op2b) | |
1997 | => (t AND inner2) | |
1998 | If the partial result t is a constant, we win. Otherwise | |
1999 | continue on to try reassociating with the other inner test. */ | |
2000 | if (is_and) | |
2001 | { | |
2002 | if (integer_onep (t)) | |
2003 | return inner2; | |
2004 | else if (integer_zerop (t)) | |
2005 | return boolean_false_node; | |
2006 | } | |
2007 | ||
2008 | /* Handle the OR case, where we are redistributing: | |
2009 | (inner1 OR inner2) AND (op2a code2 op2b) | |
2010 | => (t OR (inner2 AND (op2a code2 op2b))) */ | |
8236c8eb JJ |
2011 | else if (integer_onep (t)) |
2012 | return boolean_true_node; | |
2013 | ||
2014 | /* Save partial result for later. */ | |
2015 | partial = t; | |
e89065a1 SL |
2016 | } |
2017 | ||
2018 | /* Compute the second partial result, (inner2 AND (op2a code op2b)) */ | |
2019 | if (TREE_CODE (inner2) == SSA_NAME | |
2020 | && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner2)) | |
2021 | && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison | |
2022 | && (t = maybe_fold_and_comparisons (gimple_assign_rhs_code (s), | |
2023 | gimple_assign_rhs1 (s), | |
2024 | gimple_assign_rhs2 (s), | |
2025 | code2, op2a, op2b))) | |
2026 | { | |
2027 | /* Handle the AND case, where we are reassociating: | |
2028 | (inner1 AND inner2) AND (op2a code2 op2b) | |
2029 | => (inner1 AND t) */ | |
2030 | if (is_and) | |
2031 | { | |
2032 | if (integer_onep (t)) | |
2033 | return inner1; | |
2034 | else if (integer_zerop (t)) | |
2035 | return boolean_false_node; | |
8236c8eb JJ |
2036 | /* If both are the same, we can apply the identity |
2037 | (x AND x) == x. */ | |
2038 | else if (partial && same_bool_result_p (t, partial)) | |
2039 | return t; | |
e89065a1 SL |
2040 | } |
2041 | ||
2042 | /* Handle the OR case. where we are redistributing: | |
2043 | (inner1 OR inner2) AND (op2a code2 op2b) | |
2044 | => (t OR (inner1 AND (op2a code2 op2b))) | |
2045 | => (t OR partial) */ | |
2046 | else | |
2047 | { | |
2048 | if (integer_onep (t)) | |
2049 | return boolean_true_node; | |
2050 | else if (partial) | |
2051 | { | |
2052 | /* We already got a simplification for the other | |
2053 | operand to the redistributed OR expression. The | |
2054 | interesting case is when at least one is false. | |
2055 | Or, if both are the same, we can apply the identity | |
2056 | (x OR x) == x. */ | |
2057 | if (integer_zerop (partial)) | |
2058 | return t; | |
2059 | else if (integer_zerop (t)) | |
2060 | return partial; | |
2061 | else if (same_bool_result_p (t, partial)) | |
2062 | return t; | |
2063 | } | |
2064 | } | |
2065 | } | |
2066 | } | |
2067 | return NULL_TREE; | |
2068 | } | |
2069 | ||
2070 | /* Try to simplify the AND of two comparisons defined by | |
2071 | (OP1A CODE1 OP1B) and (OP2A CODE2 OP2B), respectively. | |
2072 | If this can be done without constructing an intermediate value, | |
2073 | return the resulting tree; otherwise NULL_TREE is returned. | |
2074 | This function is deliberately asymmetric as it recurses on SSA_DEFs | |
2075 | in the first comparison but not the second. */ | |
2076 | ||
2077 | static tree | |
2078 | and_comparisons_1 (enum tree_code code1, tree op1a, tree op1b, | |
2079 | enum tree_code code2, tree op2a, tree op2b) | |
2080 | { | |
2081 | /* First check for ((x CODE1 y) AND (x CODE2 y)). */ | |
2082 | if (operand_equal_p (op1a, op2a, 0) | |
2083 | && operand_equal_p (op1b, op2b, 0)) | |
2084 | { | |
2085 | tree t = combine_comparisons (UNKNOWN_LOCATION, | |
2086 | TRUTH_ANDIF_EXPR, code1, code2, | |
2087 | boolean_type_node, op1a, op1b); | |
2088 | if (t) | |
2089 | return t; | |
2090 | } | |
2091 | ||
2092 | /* Likewise the swapped case of the above. */ | |
2093 | if (operand_equal_p (op1a, op2b, 0) | |
2094 | && operand_equal_p (op1b, op2a, 0)) | |
2095 | { | |
2096 | tree t = combine_comparisons (UNKNOWN_LOCATION, | |
2097 | TRUTH_ANDIF_EXPR, code1, | |
2098 | swap_tree_comparison (code2), | |
2099 | boolean_type_node, op1a, op1b); | |
2100 | if (t) | |
2101 | return t; | |
2102 | } | |
2103 | ||
2104 | /* If both comparisons are of the same value against constants, we might | |
2105 | be able to merge them. */ | |
2106 | if (operand_equal_p (op1a, op2a, 0) | |
2107 | && TREE_CODE (op1b) == INTEGER_CST | |
2108 | && TREE_CODE (op2b) == INTEGER_CST) | |
2109 | { | |
2110 | int cmp = tree_int_cst_compare (op1b, op2b); | |
2111 | ||
2112 | /* If we have (op1a == op1b), we should either be able to | |
2113 | return that or FALSE, depending on whether the constant op1b | |
2114 | also satisfies the other comparison against op2b. */ | |
2115 | if (code1 == EQ_EXPR) | |
2116 | { | |
2117 | bool done = true; | |
2118 | bool val; | |
2119 | switch (code2) | |
2120 | { | |
2121 | case EQ_EXPR: val = (cmp == 0); break; | |
2122 | case NE_EXPR: val = (cmp != 0); break; | |
2123 | case LT_EXPR: val = (cmp < 0); break; | |
2124 | case GT_EXPR: val = (cmp > 0); break; | |
2125 | case LE_EXPR: val = (cmp <= 0); break; | |
2126 | case GE_EXPR: val = (cmp >= 0); break; | |
2127 | default: done = false; | |
2128 | } | |
2129 | if (done) | |
2130 | { | |
2131 | if (val) | |
2132 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2133 | else | |
2134 | return boolean_false_node; | |
2135 | } | |
2136 | } | |
2137 | /* Likewise if the second comparison is an == comparison. */ | |
2138 | else if (code2 == EQ_EXPR) | |
2139 | { | |
2140 | bool done = true; | |
2141 | bool val; | |
2142 | switch (code1) | |
2143 | { | |
2144 | case EQ_EXPR: val = (cmp == 0); break; | |
2145 | case NE_EXPR: val = (cmp != 0); break; | |
2146 | case LT_EXPR: val = (cmp > 0); break; | |
2147 | case GT_EXPR: val = (cmp < 0); break; | |
2148 | case LE_EXPR: val = (cmp >= 0); break; | |
2149 | case GE_EXPR: val = (cmp <= 0); break; | |
2150 | default: done = false; | |
2151 | } | |
2152 | if (done) | |
2153 | { | |
2154 | if (val) | |
2155 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2156 | else | |
2157 | return boolean_false_node; | |
2158 | } | |
2159 | } | |
2160 | ||
2161 | /* Same business with inequality tests. */ | |
2162 | else if (code1 == NE_EXPR) | |
2163 | { | |
2164 | bool val; | |
2165 | switch (code2) | |
2166 | { | |
2167 | case EQ_EXPR: val = (cmp != 0); break; | |
2168 | case NE_EXPR: val = (cmp == 0); break; | |
2169 | case LT_EXPR: val = (cmp >= 0); break; | |
2170 | case GT_EXPR: val = (cmp <= 0); break; | |
2171 | case LE_EXPR: val = (cmp > 0); break; | |
2172 | case GE_EXPR: val = (cmp < 0); break; | |
2173 | default: | |
2174 | val = false; | |
2175 | } | |
2176 | if (val) | |
2177 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2178 | } | |
2179 | else if (code2 == NE_EXPR) | |
2180 | { | |
2181 | bool val; | |
2182 | switch (code1) | |
2183 | { | |
2184 | case EQ_EXPR: val = (cmp == 0); break; | |
2185 | case NE_EXPR: val = (cmp != 0); break; | |
2186 | case LT_EXPR: val = (cmp <= 0); break; | |
2187 | case GT_EXPR: val = (cmp >= 0); break; | |
2188 | case LE_EXPR: val = (cmp < 0); break; | |
2189 | case GE_EXPR: val = (cmp > 0); break; | |
2190 | default: | |
2191 | val = false; | |
2192 | } | |
2193 | if (val) | |
2194 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2195 | } | |
2196 | ||
2197 | /* Chose the more restrictive of two < or <= comparisons. */ | |
2198 | else if ((code1 == LT_EXPR || code1 == LE_EXPR) | |
2199 | && (code2 == LT_EXPR || code2 == LE_EXPR)) | |
2200 | { | |
2201 | if ((cmp < 0) || (cmp == 0 && code1 == LT_EXPR)) | |
2202 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2203 | else | |
2204 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2205 | } | |
2206 | ||
2207 | /* Likewise chose the more restrictive of two > or >= comparisons. */ | |
2208 | else if ((code1 == GT_EXPR || code1 == GE_EXPR) | |
2209 | && (code2 == GT_EXPR || code2 == GE_EXPR)) | |
2210 | { | |
2211 | if ((cmp > 0) || (cmp == 0 && code1 == GT_EXPR)) | |
2212 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2213 | else | |
2214 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2215 | } | |
2216 | ||
2217 | /* Check for singleton ranges. */ | |
2218 | else if (cmp == 0 | |
2219 | && ((code1 == LE_EXPR && code2 == GE_EXPR) | |
2220 | || (code1 == GE_EXPR && code2 == LE_EXPR))) | |
2221 | return fold_build2 (EQ_EXPR, boolean_type_node, op1a, op2b); | |
2222 | ||
2223 | /* Check for disjoint ranges. */ | |
2224 | else if (cmp <= 0 | |
2225 | && (code1 == LT_EXPR || code1 == LE_EXPR) | |
2226 | && (code2 == GT_EXPR || code2 == GE_EXPR)) | |
2227 | return boolean_false_node; | |
2228 | else if (cmp >= 0 | |
2229 | && (code1 == GT_EXPR || code1 == GE_EXPR) | |
2230 | && (code2 == LT_EXPR || code2 == LE_EXPR)) | |
2231 | return boolean_false_node; | |
2232 | } | |
2233 | ||
2234 | /* Perhaps the first comparison is (NAME != 0) or (NAME == 1) where | |
2235 | NAME's definition is a truth value. See if there are any simplifications | |
2236 | that can be done against the NAME's definition. */ | |
2237 | if (TREE_CODE (op1a) == SSA_NAME | |
2238 | && (code1 == NE_EXPR || code1 == EQ_EXPR) | |
2239 | && (integer_zerop (op1b) || integer_onep (op1b))) | |
2240 | { | |
2241 | bool invert = ((code1 == EQ_EXPR && integer_zerop (op1b)) | |
2242 | || (code1 == NE_EXPR && integer_onep (op1b))); | |
2243 | gimple stmt = SSA_NAME_DEF_STMT (op1a); | |
2244 | switch (gimple_code (stmt)) | |
2245 | { | |
2246 | case GIMPLE_ASSIGN: | |
2247 | /* Try to simplify by copy-propagating the definition. */ | |
2248 | return and_var_with_comparison (op1a, invert, code2, op2a, op2b); | |
2249 | ||
2250 | case GIMPLE_PHI: | |
2251 | /* If every argument to the PHI produces the same result when | |
2252 | ANDed with the second comparison, we win. | |
2253 | Do not do this unless the type is bool since we need a bool | |
2254 | result here anyway. */ | |
2255 | if (TREE_CODE (TREE_TYPE (op1a)) == BOOLEAN_TYPE) | |
2256 | { | |
2257 | tree result = NULL_TREE; | |
2258 | unsigned i; | |
2259 | for (i = 0; i < gimple_phi_num_args (stmt); i++) | |
2260 | { | |
2261 | tree arg = gimple_phi_arg_def (stmt, i); | |
2262 | ||
2263 | /* If this PHI has itself as an argument, ignore it. | |
2264 | If all the other args produce the same result, | |
2265 | we're still OK. */ | |
2266 | if (arg == gimple_phi_result (stmt)) | |
2267 | continue; | |
2268 | else if (TREE_CODE (arg) == INTEGER_CST) | |
2269 | { | |
2270 | if (invert ? integer_nonzerop (arg) : integer_zerop (arg)) | |
2271 | { | |
2272 | if (!result) | |
2273 | result = boolean_false_node; | |
2274 | else if (!integer_zerop (result)) | |
2275 | return NULL_TREE; | |
2276 | } | |
2277 | else if (!result) | |
2278 | result = fold_build2 (code2, boolean_type_node, | |
2279 | op2a, op2b); | |
2280 | else if (!same_bool_comparison_p (result, | |
2281 | code2, op2a, op2b)) | |
2282 | return NULL_TREE; | |
2283 | } | |
2284 | else if (TREE_CODE (arg) == SSA_NAME) | |
2285 | { | |
2286 | tree temp = and_var_with_comparison (arg, invert, | |
2287 | code2, op2a, op2b); | |
2288 | if (!temp) | |
2289 | return NULL_TREE; | |
2290 | else if (!result) | |
2291 | result = temp; | |
2292 | else if (!same_bool_result_p (result, temp)) | |
2293 | return NULL_TREE; | |
2294 | } | |
2295 | else | |
2296 | return NULL_TREE; | |
2297 | } | |
2298 | return result; | |
2299 | } | |
2300 | ||
2301 | default: | |
2302 | break; | |
2303 | } | |
2304 | } | |
2305 | return NULL_TREE; | |
2306 | } | |
2307 | ||
2308 | /* Try to simplify the AND of two comparisons, specified by | |
2309 | (OP1A CODE1 OP1B) and (OP2B CODE2 OP2B), respectively. | |
2310 | If this can be simplified to a single expression (without requiring | |
2311 | introducing more SSA variables to hold intermediate values), | |
2312 | return the resulting tree. Otherwise return NULL_TREE. | |
2313 | If the result expression is non-null, it has boolean type. */ | |
2314 | ||
2315 | tree | |
2316 | maybe_fold_and_comparisons (enum tree_code code1, tree op1a, tree op1b, | |
2317 | enum tree_code code2, tree op2a, tree op2b) | |
2318 | { | |
2319 | tree t = and_comparisons_1 (code1, op1a, op1b, code2, op2a, op2b); | |
2320 | if (t) | |
2321 | return t; | |
2322 | else | |
2323 | return and_comparisons_1 (code2, op2a, op2b, code1, op1a, op1b); | |
2324 | } | |
2325 | ||
2326 | /* Helper function for or_comparisons_1: try to simplify the OR of the | |
2327 | ssa variable VAR with the comparison specified by (OP2A CODE2 OP2B). | |
2328 | If INVERT is true, invert the value of VAR before doing the OR. | |
2329 | Return NULL_EXPR if we can't simplify this to a single expression. */ | |
2330 | ||
2331 | static tree | |
2332 | or_var_with_comparison (tree var, bool invert, | |
2333 | enum tree_code code2, tree op2a, tree op2b) | |
2334 | { | |
2335 | tree t; | |
2336 | gimple stmt = SSA_NAME_DEF_STMT (var); | |
2337 | ||
2338 | /* We can only deal with variables whose definitions are assignments. */ | |
2339 | if (!is_gimple_assign (stmt)) | |
2340 | return NULL_TREE; | |
2341 | ||
2342 | /* If we have an inverted comparison, apply DeMorgan's law and rewrite | |
2343 | !var OR (op2a code2 op2b) => !(var AND !(op2a code2 op2b)) | |
2344 | Then we only have to consider the simpler non-inverted cases. */ | |
2345 | if (invert) | |
2346 | t = and_var_with_comparison_1 (stmt, | |
2347 | invert_tree_comparison (code2, false), | |
2348 | op2a, op2b); | |
2349 | else | |
2350 | t = or_var_with_comparison_1 (stmt, code2, op2a, op2b); | |
2351 | return canonicalize_bool (t, invert); | |
2352 | } | |
2353 | ||
2354 | /* Try to simplify the OR of the ssa variable defined by the assignment | |
2355 | STMT with the comparison specified by (OP2A CODE2 OP2B). | |
2356 | Return NULL_EXPR if we can't simplify this to a single expression. */ | |
2357 | ||
2358 | static tree | |
2359 | or_var_with_comparison_1 (gimple stmt, | |
2360 | enum tree_code code2, tree op2a, tree op2b) | |
2361 | { | |
2362 | tree var = gimple_assign_lhs (stmt); | |
2363 | tree true_test_var = NULL_TREE; | |
2364 | tree false_test_var = NULL_TREE; | |
2365 | enum tree_code innercode = gimple_assign_rhs_code (stmt); | |
2366 | ||
2367 | /* Check for identities like (var OR (var != 0)) => true . */ | |
2368 | if (TREE_CODE (op2a) == SSA_NAME | |
2369 | && TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE) | |
2370 | { | |
2371 | if ((code2 == NE_EXPR && integer_zerop (op2b)) | |
2372 | || (code2 == EQ_EXPR && integer_nonzerop (op2b))) | |
2373 | { | |
2374 | true_test_var = op2a; | |
2375 | if (var == true_test_var) | |
2376 | return var; | |
2377 | } | |
2378 | else if ((code2 == EQ_EXPR && integer_zerop (op2b)) | |
2379 | || (code2 == NE_EXPR && integer_nonzerop (op2b))) | |
2380 | { | |
2381 | false_test_var = op2a; | |
2382 | if (var == false_test_var) | |
2383 | return boolean_true_node; | |
2384 | } | |
2385 | } | |
2386 | ||
2387 | /* If the definition is a comparison, recurse on it. */ | |
2388 | if (TREE_CODE_CLASS (innercode) == tcc_comparison) | |
2389 | { | |
2390 | tree t = or_comparisons_1 (innercode, | |
2391 | gimple_assign_rhs1 (stmt), | |
2392 | gimple_assign_rhs2 (stmt), | |
2393 | code2, | |
2394 | op2a, | |
2395 | op2b); | |
2396 | if (t) | |
2397 | return t; | |
2398 | } | |
2399 | ||
2400 | /* If the definition is an AND or OR expression, we may be able to | |
2401 | simplify by reassociating. */ | |
2402 | if (innercode == TRUTH_AND_EXPR | |
2403 | || innercode == TRUTH_OR_EXPR | |
2404 | || (TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE | |
2405 | && (innercode == BIT_AND_EXPR || innercode == BIT_IOR_EXPR))) | |
2406 | { | |
2407 | tree inner1 = gimple_assign_rhs1 (stmt); | |
2408 | tree inner2 = gimple_assign_rhs2 (stmt); | |
2409 | gimple s; | |
2410 | tree t; | |
2411 | tree partial = NULL_TREE; | |
2412 | bool is_or = (innercode == TRUTH_OR_EXPR || innercode == BIT_IOR_EXPR); | |
2413 | ||
2414 | /* Check for boolean identities that don't require recursive examination | |
2415 | of inner1/inner2: | |
2416 | inner1 OR (inner1 OR inner2) => inner1 OR inner2 => var | |
2417 | inner1 OR (inner1 AND inner2) => inner1 | |
2418 | !inner1 OR (inner1 OR inner2) => true | |
2419 | !inner1 OR (inner1 AND inner2) => !inner1 OR inner2 | |
2420 | */ | |
2421 | if (inner1 == true_test_var) | |
2422 | return (is_or ? var : inner1); | |
2423 | else if (inner2 == true_test_var) | |
2424 | return (is_or ? var : inner2); | |
2425 | else if (inner1 == false_test_var) | |
2426 | return (is_or | |
2427 | ? boolean_true_node | |
2428 | : or_var_with_comparison (inner2, false, code2, op2a, op2b)); | |
2429 | else if (inner2 == false_test_var) | |
2430 | return (is_or | |
2431 | ? boolean_true_node | |
2432 | : or_var_with_comparison (inner1, false, code2, op2a, op2b)); | |
2433 | ||
2434 | /* Next, redistribute/reassociate the OR across the inner tests. | |
2435 | Compute the first partial result, (inner1 OR (op2a code op2b)) */ | |
2436 | if (TREE_CODE (inner1) == SSA_NAME | |
2437 | && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner1)) | |
2438 | && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison | |
2439 | && (t = maybe_fold_or_comparisons (gimple_assign_rhs_code (s), | |
2440 | gimple_assign_rhs1 (s), | |
2441 | gimple_assign_rhs2 (s), | |
2442 | code2, op2a, op2b))) | |
2443 | { | |
2444 | /* Handle the OR case, where we are reassociating: | |
2445 | (inner1 OR inner2) OR (op2a code2 op2b) | |
2446 | => (t OR inner2) | |
2447 | If the partial result t is a constant, we win. Otherwise | |
2448 | continue on to try reassociating with the other inner test. */ | |
8236c8eb | 2449 | if (is_or) |
e89065a1 SL |
2450 | { |
2451 | if (integer_onep (t)) | |
2452 | return boolean_true_node; | |
2453 | else if (integer_zerop (t)) | |
2454 | return inner2; | |
2455 | } | |
2456 | ||
2457 | /* Handle the AND case, where we are redistributing: | |
2458 | (inner1 AND inner2) OR (op2a code2 op2b) | |
2459 | => (t AND (inner2 OR (op2a code op2b))) */ | |
8236c8eb JJ |
2460 | else if (integer_zerop (t)) |
2461 | return boolean_false_node; | |
2462 | ||
2463 | /* Save partial result for later. */ | |
2464 | partial = t; | |
e89065a1 SL |
2465 | } |
2466 | ||
2467 | /* Compute the second partial result, (inner2 OR (op2a code op2b)) */ | |
2468 | if (TREE_CODE (inner2) == SSA_NAME | |
2469 | && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner2)) | |
2470 | && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison | |
2471 | && (t = maybe_fold_or_comparisons (gimple_assign_rhs_code (s), | |
2472 | gimple_assign_rhs1 (s), | |
2473 | gimple_assign_rhs2 (s), | |
2474 | code2, op2a, op2b))) | |
2475 | { | |
2476 | /* Handle the OR case, where we are reassociating: | |
2477 | (inner1 OR inner2) OR (op2a code2 op2b) | |
8236c8eb JJ |
2478 | => (inner1 OR t) |
2479 | => (t OR partial) */ | |
2480 | if (is_or) | |
e89065a1 SL |
2481 | { |
2482 | if (integer_zerop (t)) | |
2483 | return inner1; | |
2484 | else if (integer_onep (t)) | |
2485 | return boolean_true_node; | |
8236c8eb JJ |
2486 | /* If both are the same, we can apply the identity |
2487 | (x OR x) == x. */ | |
2488 | else if (partial && same_bool_result_p (t, partial)) | |
2489 | return t; | |
e89065a1 SL |
2490 | } |
2491 | ||
2492 | /* Handle the AND case, where we are redistributing: | |
2493 | (inner1 AND inner2) OR (op2a code2 op2b) | |
2494 | => (t AND (inner1 OR (op2a code2 op2b))) | |
2495 | => (t AND partial) */ | |
2496 | else | |
2497 | { | |
2498 | if (integer_zerop (t)) | |
2499 | return boolean_false_node; | |
2500 | else if (partial) | |
2501 | { | |
2502 | /* We already got a simplification for the other | |
2503 | operand to the redistributed AND expression. The | |
2504 | interesting case is when at least one is true. | |
2505 | Or, if both are the same, we can apply the identity | |
8236c8eb | 2506 | (x AND x) == x. */ |
e89065a1 SL |
2507 | if (integer_onep (partial)) |
2508 | return t; | |
2509 | else if (integer_onep (t)) | |
2510 | return partial; | |
2511 | else if (same_bool_result_p (t, partial)) | |
8236c8eb | 2512 | return t; |
e89065a1 SL |
2513 | } |
2514 | } | |
2515 | } | |
2516 | } | |
2517 | return NULL_TREE; | |
2518 | } | |
2519 | ||
2520 | /* Try to simplify the OR of two comparisons defined by | |
2521 | (OP1A CODE1 OP1B) and (OP2A CODE2 OP2B), respectively. | |
2522 | If this can be done without constructing an intermediate value, | |
2523 | return the resulting tree; otherwise NULL_TREE is returned. | |
2524 | This function is deliberately asymmetric as it recurses on SSA_DEFs | |
2525 | in the first comparison but not the second. */ | |
2526 | ||
2527 | static tree | |
2528 | or_comparisons_1 (enum tree_code code1, tree op1a, tree op1b, | |
2529 | enum tree_code code2, tree op2a, tree op2b) | |
2530 | { | |
2531 | /* First check for ((x CODE1 y) OR (x CODE2 y)). */ | |
2532 | if (operand_equal_p (op1a, op2a, 0) | |
2533 | && operand_equal_p (op1b, op2b, 0)) | |
2534 | { | |
2535 | tree t = combine_comparisons (UNKNOWN_LOCATION, | |
2536 | TRUTH_ORIF_EXPR, code1, code2, | |
2537 | boolean_type_node, op1a, op1b); | |
2538 | if (t) | |
2539 | return t; | |
2540 | } | |
2541 | ||
2542 | /* Likewise the swapped case of the above. */ | |
2543 | if (operand_equal_p (op1a, op2b, 0) | |
2544 | && operand_equal_p (op1b, op2a, 0)) | |
2545 | { | |
2546 | tree t = combine_comparisons (UNKNOWN_LOCATION, | |
2547 | TRUTH_ORIF_EXPR, code1, | |
2548 | swap_tree_comparison (code2), | |
2549 | boolean_type_node, op1a, op1b); | |
2550 | if (t) | |
2551 | return t; | |
2552 | } | |
2553 | ||
2554 | /* If both comparisons are of the same value against constants, we might | |
2555 | be able to merge them. */ | |
2556 | if (operand_equal_p (op1a, op2a, 0) | |
2557 | && TREE_CODE (op1b) == INTEGER_CST | |
2558 | && TREE_CODE (op2b) == INTEGER_CST) | |
2559 | { | |
2560 | int cmp = tree_int_cst_compare (op1b, op2b); | |
2561 | ||
2562 | /* If we have (op1a != op1b), we should either be able to | |
2563 | return that or TRUE, depending on whether the constant op1b | |
2564 | also satisfies the other comparison against op2b. */ | |
2565 | if (code1 == NE_EXPR) | |
2566 | { | |
2567 | bool done = true; | |
2568 | bool val; | |
2569 | switch (code2) | |
2570 | { | |
2571 | case EQ_EXPR: val = (cmp == 0); break; | |
2572 | case NE_EXPR: val = (cmp != 0); break; | |
2573 | case LT_EXPR: val = (cmp < 0); break; | |
2574 | case GT_EXPR: val = (cmp > 0); break; | |
2575 | case LE_EXPR: val = (cmp <= 0); break; | |
2576 | case GE_EXPR: val = (cmp >= 0); break; | |
2577 | default: done = false; | |
2578 | } | |
2579 | if (done) | |
2580 | { | |
2581 | if (val) | |
2582 | return boolean_true_node; | |
2583 | else | |
2584 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2585 | } | |
2586 | } | |
2587 | /* Likewise if the second comparison is a != comparison. */ | |
2588 | else if (code2 == NE_EXPR) | |
2589 | { | |
2590 | bool done = true; | |
2591 | bool val; | |
2592 | switch (code1) | |
2593 | { | |
2594 | case EQ_EXPR: val = (cmp == 0); break; | |
2595 | case NE_EXPR: val = (cmp != 0); break; | |
2596 | case LT_EXPR: val = (cmp > 0); break; | |
2597 | case GT_EXPR: val = (cmp < 0); break; | |
2598 | case LE_EXPR: val = (cmp >= 0); break; | |
2599 | case GE_EXPR: val = (cmp <= 0); break; | |
2600 | default: done = false; | |
2601 | } | |
2602 | if (done) | |
2603 | { | |
2604 | if (val) | |
2605 | return boolean_true_node; | |
2606 | else | |
2607 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2608 | } | |
2609 | } | |
2610 | ||
2611 | /* See if an equality test is redundant with the other comparison. */ | |
2612 | else if (code1 == EQ_EXPR) | |
2613 | { | |
2614 | bool val; | |
2615 | switch (code2) | |
2616 | { | |
2617 | case EQ_EXPR: val = (cmp == 0); break; | |
2618 | case NE_EXPR: val = (cmp != 0); break; | |
2619 | case LT_EXPR: val = (cmp < 0); break; | |
2620 | case GT_EXPR: val = (cmp > 0); break; | |
2621 | case LE_EXPR: val = (cmp <= 0); break; | |
2622 | case GE_EXPR: val = (cmp >= 0); break; | |
2623 | default: | |
2624 | val = false; | |
2625 | } | |
2626 | if (val) | |
2627 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2628 | } | |
2629 | else if (code2 == EQ_EXPR) | |
2630 | { | |
2631 | bool val; | |
2632 | switch (code1) | |
2633 | { | |
2634 | case EQ_EXPR: val = (cmp == 0); break; | |
2635 | case NE_EXPR: val = (cmp != 0); break; | |
2636 | case LT_EXPR: val = (cmp > 0); break; | |
2637 | case GT_EXPR: val = (cmp < 0); break; | |
2638 | case LE_EXPR: val = (cmp >= 0); break; | |
2639 | case GE_EXPR: val = (cmp <= 0); break; | |
2640 | default: | |
2641 | val = false; | |
2642 | } | |
2643 | if (val) | |
2644 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2645 | } | |
2646 | ||
2647 | /* Chose the less restrictive of two < or <= comparisons. */ | |
2648 | else if ((code1 == LT_EXPR || code1 == LE_EXPR) | |
2649 | && (code2 == LT_EXPR || code2 == LE_EXPR)) | |
2650 | { | |
2651 | if ((cmp < 0) || (cmp == 0 && code1 == LT_EXPR)) | |
2652 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2653 | else | |
2654 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2655 | } | |
2656 | ||
2657 | /* Likewise chose the less restrictive of two > or >= comparisons. */ | |
2658 | else if ((code1 == GT_EXPR || code1 == GE_EXPR) | |
2659 | && (code2 == GT_EXPR || code2 == GE_EXPR)) | |
2660 | { | |
2661 | if ((cmp > 0) || (cmp == 0 && code1 == GT_EXPR)) | |
2662 | return fold_build2 (code2, boolean_type_node, op2a, op2b); | |
2663 | else | |
2664 | return fold_build2 (code1, boolean_type_node, op1a, op1b); | |
2665 | } | |
2666 | ||
2667 | /* Check for singleton ranges. */ | |
2668 | else if (cmp == 0 | |
2669 | && ((code1 == LT_EXPR && code2 == GT_EXPR) | |
2670 | || (code1 == GT_EXPR && code2 == LT_EXPR))) | |
2671 | return fold_build2 (NE_EXPR, boolean_type_node, op1a, op2b); | |
2672 | ||
2673 | /* Check for less/greater pairs that don't restrict the range at all. */ | |
2674 | else if (cmp >= 0 | |
2675 | && (code1 == LT_EXPR || code1 == LE_EXPR) | |
2676 | && (code2 == GT_EXPR || code2 == GE_EXPR)) | |
2677 | return boolean_true_node; | |
2678 | else if (cmp <= 0 | |
2679 | && (code1 == GT_EXPR || code1 == GE_EXPR) | |
2680 | && (code2 == LT_EXPR || code2 == LE_EXPR)) | |
2681 | return boolean_true_node; | |
2682 | } | |
2683 | ||
2684 | /* Perhaps the first comparison is (NAME != 0) or (NAME == 1) where | |
2685 | NAME's definition is a truth value. See if there are any simplifications | |
2686 | that can be done against the NAME's definition. */ | |
2687 | if (TREE_CODE (op1a) == SSA_NAME | |
2688 | && (code1 == NE_EXPR || code1 == EQ_EXPR) | |
2689 | && (integer_zerop (op1b) || integer_onep (op1b))) | |
2690 | { | |
2691 | bool invert = ((code1 == EQ_EXPR && integer_zerop (op1b)) | |
2692 | || (code1 == NE_EXPR && integer_onep (op1b))); | |
2693 | gimple stmt = SSA_NAME_DEF_STMT (op1a); | |
2694 | switch (gimple_code (stmt)) | |
2695 | { | |
2696 | case GIMPLE_ASSIGN: | |
2697 | /* Try to simplify by copy-propagating the definition. */ | |
2698 | return or_var_with_comparison (op1a, invert, code2, op2a, op2b); | |
2699 | ||
2700 | case GIMPLE_PHI: | |
2701 | /* If every argument to the PHI produces the same result when | |
2702 | ORed with the second comparison, we win. | |
2703 | Do not do this unless the type is bool since we need a bool | |
2704 | result here anyway. */ | |
2705 | if (TREE_CODE (TREE_TYPE (op1a)) == BOOLEAN_TYPE) | |
2706 | { | |
2707 | tree result = NULL_TREE; | |
2708 | unsigned i; | |
2709 | for (i = 0; i < gimple_phi_num_args (stmt); i++) | |
2710 | { | |
2711 | tree arg = gimple_phi_arg_def (stmt, i); | |
2712 | ||
2713 | /* If this PHI has itself as an argument, ignore it. | |
2714 | If all the other args produce the same result, | |
2715 | we're still OK. */ | |
2716 | if (arg == gimple_phi_result (stmt)) | |
2717 | continue; | |
2718 | else if (TREE_CODE (arg) == INTEGER_CST) | |
2719 | { | |
2720 | if (invert ? integer_zerop (arg) : integer_nonzerop (arg)) | |
2721 | { | |
2722 | if (!result) | |
2723 | result = boolean_true_node; | |
2724 | else if (!integer_onep (result)) | |
2725 | return NULL_TREE; | |
2726 | } | |
2727 | else if (!result) | |
2728 | result = fold_build2 (code2, boolean_type_node, | |
2729 | op2a, op2b); | |
2730 | else if (!same_bool_comparison_p (result, | |
2731 | code2, op2a, op2b)) | |
2732 | return NULL_TREE; | |
2733 | } | |
2734 | else if (TREE_CODE (arg) == SSA_NAME) | |
2735 | { | |
2736 | tree temp = or_var_with_comparison (arg, invert, | |
2737 | code2, op2a, op2b); | |
2738 | if (!temp) | |
2739 | return NULL_TREE; | |
2740 | else if (!result) | |
2741 | result = temp; | |
2742 | else if (!same_bool_result_p (result, temp)) | |
2743 | return NULL_TREE; | |
2744 | } | |
2745 | else | |
2746 | return NULL_TREE; | |
2747 | } | |
2748 | return result; | |
2749 | } | |
2750 | ||
2751 | default: | |
2752 | break; | |
2753 | } | |
2754 | } | |
2755 | return NULL_TREE; | |
2756 | } | |
2757 | ||
2758 | /* Try to simplify the OR of two comparisons, specified by | |
2759 | (OP1A CODE1 OP1B) and (OP2B CODE2 OP2B), respectively. | |
2760 | If this can be simplified to a single expression (without requiring | |
2761 | introducing more SSA variables to hold intermediate values), | |
2762 | return the resulting tree. Otherwise return NULL_TREE. | |
2763 | If the result expression is non-null, it has boolean type. */ | |
2764 | ||
2765 | tree | |
2766 | maybe_fold_or_comparisons (enum tree_code code1, tree op1a, tree op1b, | |
2767 | enum tree_code code2, tree op2a, tree op2b) | |
2768 | { | |
2769 | tree t = or_comparisons_1 (code1, op1a, op1b, code2, op2a, op2b); | |
2770 | if (t) | |
2771 | return t; | |
2772 | else | |
2773 | return or_comparisons_1 (code2, op2a, op2b, code1, op1a, op1b); | |
2774 | } |