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6de9cd9a | 1 | /* Conditional constant propagation pass for the GNU compiler. |
fa10beec | 2 | Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 |
1e052c19 | 3 | Free Software Foundation, Inc. |
6de9cd9a DN |
4 | Adapted from original RTL SSA-CCP by Daniel Berlin <dberlin@dberlin.org> |
5 | Adapted to GIMPLE trees by Diego Novillo <dnovillo@redhat.com> | |
6 | ||
7 | This file is part of GCC. | |
8 | ||
9 | GCC is free software; you can redistribute it and/or modify it | |
10 | under the terms of the GNU General Public License as published by the | |
9dcd6f09 | 11 | Free Software Foundation; either version 3, or (at your option) any |
6de9cd9a DN |
12 | later version. |
13 | ||
14 | GCC is distributed in the hope that it will be useful, but WITHOUT | |
15 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
16 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
17 | for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
9dcd6f09 NC |
20 | along with GCC; see the file COPYING3. If not see |
21 | <http://www.gnu.org/licenses/>. */ | |
6de9cd9a | 22 | |
0bca51f0 DN |
23 | /* Conditional constant propagation (CCP) is based on the SSA |
24 | propagation engine (tree-ssa-propagate.c). Constant assignments of | |
25 | the form VAR = CST are propagated from the assignments into uses of | |
26 | VAR, which in turn may generate new constants. The simulation uses | |
27 | a four level lattice to keep track of constant values associated | |
28 | with SSA names. Given an SSA name V_i, it may take one of the | |
29 | following values: | |
30 | ||
106dec71 ZD |
31 | UNINITIALIZED -> the initial state of the value. This value |
32 | is replaced with a correct initial value | |
33 | the first time the value is used, so the | |
34 | rest of the pass does not need to care about | |
35 | it. Using this value simplifies initialization | |
36 | of the pass, and prevents us from needlessly | |
37 | scanning statements that are never reached. | |
0bca51f0 DN |
38 | |
39 | UNDEFINED -> V_i is a local variable whose definition | |
40 | has not been processed yet. Therefore we | |
41 | don't yet know if its value is a constant | |
42 | or not. | |
43 | ||
44 | CONSTANT -> V_i has been found to hold a constant | |
45 | value C. | |
46 | ||
47 | VARYING -> V_i cannot take a constant value, or if it | |
48 | does, it is not possible to determine it | |
49 | at compile time. | |
50 | ||
51 | The core of SSA-CCP is in ccp_visit_stmt and ccp_visit_phi_node: | |
52 | ||
53 | 1- In ccp_visit_stmt, we are interested in assignments whose RHS | |
54 | evaluates into a constant and conditional jumps whose predicate | |
55 | evaluates into a boolean true or false. When an assignment of | |
56 | the form V_i = CONST is found, V_i's lattice value is set to | |
57 | CONSTANT and CONST is associated with it. This causes the | |
58 | propagation engine to add all the SSA edges coming out the | |
59 | assignment into the worklists, so that statements that use V_i | |
60 | can be visited. | |
61 | ||
62 | If the statement is a conditional with a constant predicate, we | |
63 | mark the outgoing edges as executable or not executable | |
64 | depending on the predicate's value. This is then used when | |
65 | visiting PHI nodes to know when a PHI argument can be ignored. | |
66 | ||
67 | ||
68 | 2- In ccp_visit_phi_node, if all the PHI arguments evaluate to the | |
69 | same constant C, then the LHS of the PHI is set to C. This | |
70 | evaluation is known as the "meet operation". Since one of the | |
71 | goals of this evaluation is to optimistically return constant | |
72 | values as often as possible, it uses two main short cuts: | |
73 | ||
74 | - If an argument is flowing in through a non-executable edge, it | |
75 | is ignored. This is useful in cases like this: | |
76 | ||
77 | if (PRED) | |
78 | a_9 = 3; | |
79 | else | |
80 | a_10 = 100; | |
81 | a_11 = PHI (a_9, a_10) | |
82 | ||
83 | If PRED is known to always evaluate to false, then we can | |
84 | assume that a_11 will always take its value from a_10, meaning | |
85 | that instead of consider it VARYING (a_9 and a_10 have | |
86 | different values), we can consider it CONSTANT 100. | |
87 | ||
88 | - If an argument has an UNDEFINED value, then it does not affect | |
89 | the outcome of the meet operation. If a variable V_i has an | |
90 | UNDEFINED value, it means that either its defining statement | |
91 | hasn't been visited yet or V_i has no defining statement, in | |
92 | which case the original symbol 'V' is being used | |
93 | uninitialized. Since 'V' is a local variable, the compiler | |
94 | may assume any initial value for it. | |
95 | ||
96 | ||
97 | After propagation, every variable V_i that ends up with a lattice | |
98 | value of CONSTANT will have the associated constant value in the | |
99 | array CONST_VAL[i].VALUE. That is fed into substitute_and_fold for | |
100 | final substitution and folding. | |
101 | ||
102 | ||
103 | Constant propagation in stores and loads (STORE-CCP) | |
104 | ---------------------------------------------------- | |
105 | ||
106 | While CCP has all the logic to propagate constants in GIMPLE | |
107 | registers, it is missing the ability to associate constants with | |
108 | stores and loads (i.e., pointer dereferences, structures and | |
109 | global/aliased variables). We don't keep loads and stores in | |
110 | SSA, but we do build a factored use-def web for them (in the | |
111 | virtual operands). | |
112 | ||
113 | For instance, consider the following code fragment: | |
114 | ||
115 | struct A a; | |
116 | const int B = 42; | |
117 | ||
118 | void foo (int i) | |
119 | { | |
120 | if (i > 10) | |
121 | a.a = 42; | |
122 | else | |
123 | { | |
124 | a.b = 21; | |
125 | a.a = a.b + 21; | |
126 | } | |
127 | ||
128 | if (a.a != B) | |
129 | never_executed (); | |
130 | } | |
131 | ||
132 | We should be able to deduce that the predicate 'a.a != B' is always | |
133 | false. To achieve this, we associate constant values to the SSA | |
38635499 DN |
134 | names in the VDEF operands for each store. Additionally, |
135 | since we also glob partial loads/stores with the base symbol, we | |
136 | also keep track of the memory reference where the constant value | |
137 | was stored (in the MEM_REF field of PROP_VALUE_T). For instance, | |
0bca51f0 | 138 | |
38635499 | 139 | # a_5 = VDEF <a_4> |
0bca51f0 DN |
140 | a.a = 2; |
141 | ||
142 | # VUSE <a_5> | |
143 | x_3 = a.b; | |
144 | ||
145 | In the example above, CCP will associate value '2' with 'a_5', but | |
146 | it would be wrong to replace the load from 'a.b' with '2', because | |
147 | '2' had been stored into a.a. | |
148 | ||
106dec71 ZD |
149 | Note that the initial value of virtual operands is VARYING, not |
150 | UNDEFINED. Consider, for instance global variables: | |
0bca51f0 DN |
151 | |
152 | int A; | |
153 | ||
154 | foo (int i) | |
155 | { | |
156 | if (i_3 > 10) | |
157 | A_4 = 3; | |
158 | # A_5 = PHI (A_4, A_2); | |
159 | ||
160 | # VUSE <A_5> | |
161 | A.0_6 = A; | |
162 | ||
163 | return A.0_6; | |
164 | } | |
165 | ||
166 | The value of A_2 cannot be assumed to be UNDEFINED, as it may have | |
167 | been defined outside of foo. If we were to assume it UNDEFINED, we | |
106dec71 | 168 | would erroneously optimize the above into 'return 3;'. |
0bca51f0 DN |
169 | |
170 | Though STORE-CCP is not too expensive, it does have to do more work | |
171 | than regular CCP, so it is only enabled at -O2. Both regular CCP | |
172 | and STORE-CCP use the exact same algorithm. The only distinction | |
173 | is that when doing STORE-CCP, the boolean variable DO_STORE_CCP is | |
174 | set to true. This affects the evaluation of statements and PHI | |
175 | nodes. | |
6de9cd9a DN |
176 | |
177 | References: | |
178 | ||
179 | Constant propagation with conditional branches, | |
180 | Wegman and Zadeck, ACM TOPLAS 13(2):181-210. | |
181 | ||
182 | Building an Optimizing Compiler, | |
183 | Robert Morgan, Butterworth-Heinemann, 1998, Section 8.9. | |
184 | ||
185 | Advanced Compiler Design and Implementation, | |
186 | Steven Muchnick, Morgan Kaufmann, 1997, Section 12.6 */ | |
187 | ||
188 | #include "config.h" | |
189 | #include "system.h" | |
190 | #include "coretypes.h" | |
191 | #include "tm.h" | |
6de9cd9a | 192 | #include "tree.h" |
750628d8 | 193 | #include "flags.h" |
6de9cd9a DN |
194 | #include "rtl.h" |
195 | #include "tm_p.h" | |
750628d8 | 196 | #include "ggc.h" |
6de9cd9a | 197 | #include "basic-block.h" |
750628d8 | 198 | #include "output.h" |
750628d8 DN |
199 | #include "expr.h" |
200 | #include "function.h" | |
6de9cd9a | 201 | #include "diagnostic.h" |
750628d8 | 202 | #include "timevar.h" |
6de9cd9a | 203 | #include "tree-dump.h" |
750628d8 | 204 | #include "tree-flow.h" |
6de9cd9a | 205 | #include "tree-pass.h" |
750628d8 | 206 | #include "tree-ssa-propagate.h" |
53a8f709 | 207 | #include "value-prof.h" |
750628d8 | 208 | #include "langhooks.h" |
ae3df618 | 209 | #include "target.h" |
6ac01510 | 210 | #include "toplev.h" |
6de9cd9a DN |
211 | |
212 | ||
213 | /* Possible lattice values. */ | |
214 | typedef enum | |
215 | { | |
106dec71 | 216 | UNINITIALIZED, |
6de9cd9a DN |
217 | UNDEFINED, |
218 | CONSTANT, | |
219 | VARYING | |
0bca51f0 | 220 | } ccp_lattice_t; |
6de9cd9a | 221 | |
0bca51f0 DN |
222 | /* Array of propagated constant values. After propagation, |
223 | CONST_VAL[I].VALUE holds the constant value for SSA_NAME(I). If | |
224 | the constant is held in an SSA name representing a memory store | |
38635499 DN |
225 | (i.e., a VDEF), CONST_VAL[I].MEM_REF will contain the actual |
226 | memory reference used to store (i.e., the LHS of the assignment | |
227 | doing the store). */ | |
404f4351 | 228 | static prop_value_t *const_val; |
6de9cd9a | 229 | |
0bca51f0 DN |
230 | /* True if we are also propagating constants in stores and loads. */ |
231 | static bool do_store_ccp; | |
6de9cd9a | 232 | |
0bca51f0 | 233 | /* Dump constant propagation value VAL to file OUTF prefixed by PREFIX. */ |
95eec0d6 DB |
234 | |
235 | static void | |
0bca51f0 | 236 | dump_lattice_value (FILE *outf, const char *prefix, prop_value_t val) |
95eec0d6 | 237 | { |
750628d8 | 238 | switch (val.lattice_val) |
95eec0d6 | 239 | { |
0bca51f0 DN |
240 | case UNINITIALIZED: |
241 | fprintf (outf, "%sUNINITIALIZED", prefix); | |
242 | break; | |
750628d8 DN |
243 | case UNDEFINED: |
244 | fprintf (outf, "%sUNDEFINED", prefix); | |
245 | break; | |
246 | case VARYING: | |
247 | fprintf (outf, "%sVARYING", prefix); | |
248 | break; | |
750628d8 DN |
249 | case CONSTANT: |
250 | fprintf (outf, "%sCONSTANT ", prefix); | |
0bca51f0 | 251 | print_generic_expr (outf, val.value, dump_flags); |
750628d8 DN |
252 | break; |
253 | default: | |
1e128c5f | 254 | gcc_unreachable (); |
750628d8 | 255 | } |
95eec0d6 | 256 | } |
6de9cd9a | 257 | |
6de9cd9a | 258 | |
0bca51f0 DN |
259 | /* Print lattice value VAL to stderr. */ |
260 | ||
261 | void debug_lattice_value (prop_value_t val); | |
262 | ||
263 | void | |
264 | debug_lattice_value (prop_value_t val) | |
265 | { | |
266 | dump_lattice_value (stderr, "", val); | |
267 | fprintf (stderr, "\n"); | |
268 | } | |
6de9cd9a | 269 | |
6de9cd9a | 270 | |
fc9962ee ZD |
271 | /* If SYM is a constant variable with known value, return the value. |
272 | NULL_TREE is returned otherwise. */ | |
273 | ||
ed97ddc6 | 274 | tree |
fc9962ee ZD |
275 | get_symbol_constant_value (tree sym) |
276 | { | |
277 | if (TREE_STATIC (sym) | |
278 | && TREE_READONLY (sym) | |
ed97ddc6 | 279 | && !MTAG_P (sym)) |
fc9962ee ZD |
280 | { |
281 | tree val = DECL_INITIAL (sym); | |
62bc00e2 RG |
282 | if (val) |
283 | { | |
284 | STRIP_USELESS_TYPE_CONVERSION (val); | |
285 | if (is_gimple_min_invariant (val)) | |
286 | return val; | |
287 | } | |
b0940154 | 288 | /* Variables declared 'const' without an initializer |
fa10beec | 289 | have zero as the initializer if they may not be |
ed97ddc6 | 290 | overridden at link or run time. */ |
b0940154 | 291 | if (!val |
ed97ddc6 | 292 | && targetm.binds_local_p (sym) |
b0940154 AP |
293 | && (INTEGRAL_TYPE_P (TREE_TYPE (sym)) |
294 | || SCALAR_FLOAT_TYPE_P (TREE_TYPE (sym)))) | |
295 | return fold_convert (TREE_TYPE (sym), integer_zero_node); | |
fc9962ee ZD |
296 | } |
297 | ||
298 | return NULL_TREE; | |
299 | } | |
688e936d | 300 | |
0bca51f0 DN |
301 | /* Compute a default value for variable VAR and store it in the |
302 | CONST_VAL array. The following rules are used to get default | |
303 | values: | |
95eec0d6 | 304 | |
0bca51f0 DN |
305 | 1- Global and static variables that are declared constant are |
306 | considered CONSTANT. | |
307 | ||
308 | 2- Any other value is considered UNDEFINED. This is useful when | |
750628d8 DN |
309 | considering PHI nodes. PHI arguments that are undefined do not |
310 | change the constant value of the PHI node, which allows for more | |
0bca51f0 | 311 | constants to be propagated. |
6de9cd9a | 312 | |
0bca51f0 DN |
313 | 3- If SSA_NAME_VALUE is set and it is a constant, its value is |
314 | used. | |
6de9cd9a | 315 | |
0bca51f0 DN |
316 | 4- Variables defined by statements other than assignments and PHI |
317 | nodes are considered VARYING. | |
6de9cd9a | 318 | |
106dec71 ZD |
319 | 5- Initial values of variables that are not GIMPLE registers are |
320 | considered VARYING. */ | |
6de9cd9a | 321 | |
0bca51f0 DN |
322 | static prop_value_t |
323 | get_default_value (tree var) | |
324 | { | |
325 | tree sym = SSA_NAME_VAR (var); | |
326 | prop_value_t val = { UNINITIALIZED, NULL_TREE, NULL_TREE }; | |
fc9962ee | 327 | tree cst_val; |
106dec71 | 328 | |
0bca51f0 | 329 | if (!do_store_ccp && !is_gimple_reg (var)) |
6de9cd9a | 330 | { |
0bca51f0 DN |
331 | /* Short circuit for regular CCP. We are not interested in any |
332 | non-register when DO_STORE_CCP is false. */ | |
750628d8 | 333 | val.lattice_val = VARYING; |
6de9cd9a | 334 | } |
0bca51f0 DN |
335 | else if (SSA_NAME_VALUE (var) |
336 | && is_gimple_min_invariant (SSA_NAME_VALUE (var))) | |
750628d8 | 337 | { |
0bca51f0 DN |
338 | val.lattice_val = CONSTANT; |
339 | val.value = SSA_NAME_VALUE (var); | |
750628d8 | 340 | } |
fc9962ee | 341 | else if ((cst_val = get_symbol_constant_value (sym)) != NULL_TREE) |
750628d8 | 342 | { |
0bca51f0 DN |
343 | /* Globals and static variables declared 'const' take their |
344 | initial value. */ | |
345 | val.lattice_val = CONSTANT; | |
fc9962ee | 346 | val.value = cst_val; |
0bca51f0 | 347 | val.mem_ref = sym; |
750628d8 DN |
348 | } |
349 | else | |
350 | { | |
750628d8 | 351 | tree stmt = SSA_NAME_DEF_STMT (var); |
6de9cd9a | 352 | |
0bca51f0 DN |
353 | if (IS_EMPTY_STMT (stmt)) |
354 | { | |
355 | /* Variables defined by an empty statement are those used | |
356 | before being initialized. If VAR is a local variable, we | |
106dec71 ZD |
357 | can assume initially that it is UNDEFINED, otherwise we must |
358 | consider it VARYING. */ | |
0bca51f0 DN |
359 | if (is_gimple_reg (sym) && TREE_CODE (sym) != PARM_DECL) |
360 | val.lattice_val = UNDEFINED; | |
0bca51f0 | 361 | else |
750628d8 DN |
362 | val.lattice_val = VARYING; |
363 | } | |
07beea0d | 364 | else if (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT |
0bca51f0 DN |
365 | || TREE_CODE (stmt) == PHI_NODE) |
366 | { | |
367 | /* Any other variable defined by an assignment or a PHI node | |
106dec71 ZD |
368 | is considered UNDEFINED. */ |
369 | val.lattice_val = UNDEFINED; | |
0bca51f0 DN |
370 | } |
371 | else | |
372 | { | |
373 | /* Otherwise, VAR will never take on a constant value. */ | |
374 | val.lattice_val = VARYING; | |
375 | } | |
750628d8 | 376 | } |
6de9cd9a | 377 | |
750628d8 DN |
378 | return val; |
379 | } | |
6de9cd9a | 380 | |
6de9cd9a | 381 | |
106dec71 | 382 | /* Get the constant value associated with variable VAR. */ |
6de9cd9a | 383 | |
106dec71 ZD |
384 | static inline prop_value_t * |
385 | get_value (tree var) | |
0bca51f0 | 386 | { |
ed97ddc6 | 387 | prop_value_t *val; |
106dec71 | 388 | |
ed97ddc6 RG |
389 | if (const_val == NULL) |
390 | return NULL; | |
391 | ||
392 | val = &const_val[SSA_NAME_VERSION (var)]; | |
106dec71 | 393 | if (val->lattice_val == UNINITIALIZED) |
6de9cd9a DN |
394 | *val = get_default_value (var); |
395 | ||
396 | return val; | |
397 | } | |
398 | ||
106dec71 ZD |
399 | /* Sets the value associated with VAR to VARYING. */ |
400 | ||
401 | static inline void | |
402 | set_value_varying (tree var) | |
403 | { | |
404 | prop_value_t *val = &const_val[SSA_NAME_VERSION (var)]; | |
405 | ||
406 | val->lattice_val = VARYING; | |
407 | val->value = NULL_TREE; | |
408 | val->mem_ref = NULL_TREE; | |
409 | } | |
6de9cd9a | 410 | |
fbb5445b L |
411 | /* For float types, modify the value of VAL to make ccp work correctly |
412 | for non-standard values (-0, NaN): | |
413 | ||
414 | If HONOR_SIGNED_ZEROS is false, and VAL = -0, we canonicalize it to 0. | |
415 | If HONOR_NANS is false, and VAL is NaN, we canonicalize it to UNDEFINED. | |
416 | This is to fix the following problem (see PR 29921): Suppose we have | |
417 | ||
418 | x = 0.0 * y | |
419 | ||
420 | and we set value of y to NaN. This causes value of x to be set to NaN. | |
421 | When we later determine that y is in fact VARYING, fold uses the fact | |
422 | that HONOR_NANS is false, and we try to change the value of x to 0, | |
423 | causing an ICE. With HONOR_NANS being false, the real appearance of | |
424 | NaN would cause undefined behavior, though, so claiming that y (and x) | |
425 | are UNDEFINED initially is correct. */ | |
426 | ||
427 | static void | |
428 | canonicalize_float_value (prop_value_t *val) | |
429 | { | |
430 | enum machine_mode mode; | |
431 | tree type; | |
432 | REAL_VALUE_TYPE d; | |
433 | ||
434 | if (val->lattice_val != CONSTANT | |
435 | || TREE_CODE (val->value) != REAL_CST) | |
436 | return; | |
437 | ||
438 | d = TREE_REAL_CST (val->value); | |
439 | type = TREE_TYPE (val->value); | |
440 | mode = TYPE_MODE (type); | |
441 | ||
442 | if (!HONOR_SIGNED_ZEROS (mode) | |
443 | && REAL_VALUE_MINUS_ZERO (d)) | |
444 | { | |
445 | val->value = build_real (type, dconst0); | |
446 | return; | |
447 | } | |
448 | ||
449 | if (!HONOR_NANS (mode) | |
450 | && REAL_VALUE_ISNAN (d)) | |
451 | { | |
452 | val->lattice_val = UNDEFINED; | |
453 | val->value = NULL; | |
454 | val->mem_ref = NULL; | |
455 | return; | |
456 | } | |
457 | } | |
458 | ||
0bca51f0 DN |
459 | /* Set the value for variable VAR to NEW_VAL. Return true if the new |
460 | value is different from VAR's previous value. */ | |
6de9cd9a | 461 | |
750628d8 | 462 | static bool |
0bca51f0 | 463 | set_lattice_value (tree var, prop_value_t new_val) |
6de9cd9a | 464 | { |
106dec71 | 465 | prop_value_t *old_val = get_value (var); |
0bca51f0 | 466 | |
fbb5445b L |
467 | canonicalize_float_value (&new_val); |
468 | ||
0bca51f0 | 469 | /* Lattice transitions must always be monotonically increasing in |
106dec71 ZD |
470 | value. If *OLD_VAL and NEW_VAL are the same, return false to |
471 | inform the caller that this was a non-transition. */ | |
472 | ||
fc9962ee | 473 | gcc_assert (old_val->lattice_val < new_val.lattice_val |
0bca51f0 | 474 | || (old_val->lattice_val == new_val.lattice_val |
fc9962ee ZD |
475 | && ((!old_val->value && !new_val.value) |
476 | || operand_equal_p (old_val->value, new_val.value, 0)) | |
106dec71 | 477 | && old_val->mem_ref == new_val.mem_ref)); |
0bca51f0 DN |
478 | |
479 | if (old_val->lattice_val != new_val.lattice_val) | |
6de9cd9a | 480 | { |
750628d8 DN |
481 | if (dump_file && (dump_flags & TDF_DETAILS)) |
482 | { | |
0bca51f0 | 483 | dump_lattice_value (dump_file, "Lattice value changed to ", new_val); |
106dec71 | 484 | fprintf (dump_file, ". Adding SSA edges to worklist.\n"); |
750628d8 DN |
485 | } |
486 | ||
0bca51f0 DN |
487 | *old_val = new_val; |
488 | ||
106dec71 ZD |
489 | gcc_assert (new_val.lattice_val != UNDEFINED); |
490 | return true; | |
6de9cd9a | 491 | } |
750628d8 DN |
492 | |
493 | return false; | |
6de9cd9a DN |
494 | } |
495 | ||
496 | ||
0bca51f0 | 497 | /* Return the likely CCP lattice value for STMT. |
6de9cd9a | 498 | |
750628d8 | 499 | If STMT has no operands, then return CONSTANT. |
6de9cd9a | 500 | |
7f879c96 RG |
501 | Else if undefinedness of operands of STMT cause its value to be |
502 | undefined, then return UNDEFINED. | |
6de9cd9a | 503 | |
750628d8 | 504 | Else if any operands of STMT are constants, then return CONSTANT. |
6de9cd9a | 505 | |
750628d8 | 506 | Else return VARYING. */ |
6de9cd9a | 507 | |
0bca51f0 | 508 | static ccp_lattice_t |
750628d8 DN |
509 | likely_value (tree stmt) |
510 | { | |
7f879c96 | 511 | bool has_constant_operand, has_undefined_operand, all_undefined_operands; |
750628d8 DN |
512 | stmt_ann_t ann; |
513 | tree use; | |
514 | ssa_op_iter iter; | |
6de9cd9a | 515 | |
750628d8 | 516 | ann = stmt_ann (stmt); |
0bca51f0 DN |
517 | |
518 | /* If the statement has volatile operands, it won't fold to a | |
519 | constant value. */ | |
520 | if (ann->has_volatile_ops) | |
521 | return VARYING; | |
522 | ||
523 | /* If we are not doing store-ccp, statements with loads | |
524 | and/or stores will never fold into a constant. */ | |
525 | if (!do_store_ccp | |
ff88c5aa | 526 | && !ZERO_SSA_OPERANDS (stmt, SSA_OP_ALL_VIRTUALS)) |
750628d8 | 527 | return VARYING; |
6de9cd9a | 528 | |
0bca51f0 DN |
529 | |
530 | /* A CALL_EXPR is assumed to be varying. NOTE: This may be overly | |
531 | conservative, in the presence of const and pure calls. */ | |
750628d8 DN |
532 | if (get_call_expr_in (stmt) != NULL_TREE) |
533 | return VARYING; | |
6de9cd9a | 534 | |
0bca51f0 DN |
535 | /* Anything other than assignments and conditional jumps are not |
536 | interesting for CCP. */ | |
07beea0d | 537 | if (TREE_CODE (stmt) != GIMPLE_MODIFY_STMT |
106dec71 | 538 | && !(TREE_CODE (stmt) == RETURN_EXPR && get_rhs (stmt) != NULL_TREE) |
0bca51f0 DN |
539 | && TREE_CODE (stmt) != COND_EXPR |
540 | && TREE_CODE (stmt) != SWITCH_EXPR) | |
541 | return VARYING; | |
542 | ||
a318e3ac SB |
543 | if (is_gimple_min_invariant (get_rhs (stmt))) |
544 | return CONSTANT; | |
545 | ||
106dec71 | 546 | has_constant_operand = false; |
7f879c96 RG |
547 | has_undefined_operand = false; |
548 | all_undefined_operands = true; | |
106dec71 | 549 | FOR_EACH_SSA_TREE_OPERAND (use, stmt, iter, SSA_OP_USE | SSA_OP_VUSE) |
750628d8 | 550 | { |
106dec71 | 551 | prop_value_t *val = get_value (use); |
750628d8 | 552 | |
106dec71 | 553 | if (val->lattice_val == UNDEFINED) |
7f879c96 RG |
554 | has_undefined_operand = true; |
555 | else | |
556 | all_undefined_operands = false; | |
0bca51f0 | 557 | |
750628d8 | 558 | if (val->lattice_val == CONSTANT) |
106dec71 | 559 | has_constant_operand = true; |
6de9cd9a | 560 | } |
750628d8 | 561 | |
7f879c96 RG |
562 | /* If the operation combines operands like COMPLEX_EXPR make sure to |
563 | not mark the result UNDEFINED if only one part of the result is | |
564 | undefined. */ | |
565 | if (has_undefined_operand | |
566 | && all_undefined_operands) | |
567 | return UNDEFINED; | |
568 | else if (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT | |
569 | && has_undefined_operand) | |
570 | { | |
571 | switch (TREE_CODE (GIMPLE_STMT_OPERAND (stmt, 1))) | |
572 | { | |
573 | /* Unary operators are handled with all_undefined_operands. */ | |
574 | case PLUS_EXPR: | |
575 | case MINUS_EXPR: | |
7f879c96 | 576 | case POINTER_PLUS_EXPR: |
7f879c96 RG |
577 | /* Not MIN_EXPR, MAX_EXPR. One VARYING operand may be selected. |
578 | Not bitwise operators, one VARYING operand may specify the | |
579 | result completely. Not logical operators for the same reason. | |
0cedb9e9 RG |
580 | Not COMPLEX_EXPR as one VARYING operand makes the result partly |
581 | not UNDEFINED. Not *DIV_EXPR, comparisons and shifts because | |
582 | the undefined operand may be promoted. */ | |
7f879c96 RG |
583 | return UNDEFINED; |
584 | ||
585 | default: | |
586 | ; | |
587 | } | |
588 | } | |
589 | /* If there was an UNDEFINED operand but the result may be not UNDEFINED | |
590 | fall back to VARYING even if there were CONSTANT operands. */ | |
591 | if (has_undefined_operand) | |
592 | return VARYING; | |
593 | ||
106dec71 ZD |
594 | if (has_constant_operand |
595 | /* We do not consider virtual operands here -- load from read-only | |
596 | memory may have only VARYING virtual operands, but still be | |
597 | constant. */ | |
598 | || ZERO_SSA_OPERANDS (stmt, SSA_OP_USE)) | |
0bca51f0 DN |
599 | return CONSTANT; |
600 | ||
106dec71 | 601 | return VARYING; |
6de9cd9a DN |
602 | } |
603 | ||
106dec71 ZD |
604 | /* Returns true if STMT cannot be constant. */ |
605 | ||
606 | static bool | |
607 | surely_varying_stmt_p (tree stmt) | |
608 | { | |
609 | /* If the statement has operands that we cannot handle, it cannot be | |
610 | constant. */ | |
611 | if (stmt_ann (stmt)->has_volatile_ops) | |
612 | return true; | |
613 | ||
614 | if (!ZERO_SSA_OPERANDS (stmt, SSA_OP_ALL_VIRTUALS)) | |
615 | { | |
616 | if (!do_store_ccp) | |
617 | return true; | |
618 | ||
619 | /* We can only handle simple loads and stores. */ | |
620 | if (!stmt_makes_single_load (stmt) | |
621 | && !stmt_makes_single_store (stmt)) | |
622 | return true; | |
623 | } | |
624 | ||
625 | /* If it contains a call, it is varying. */ | |
626 | if (get_call_expr_in (stmt) != NULL_TREE) | |
627 | return true; | |
628 | ||
629 | /* Anything other than assignments and conditional jumps are not | |
630 | interesting for CCP. */ | |
07beea0d | 631 | if (TREE_CODE (stmt) != GIMPLE_MODIFY_STMT |
106dec71 ZD |
632 | && !(TREE_CODE (stmt) == RETURN_EXPR && get_rhs (stmt) != NULL_TREE) |
633 | && TREE_CODE (stmt) != COND_EXPR | |
634 | && TREE_CODE (stmt) != SWITCH_EXPR) | |
635 | return true; | |
636 | ||
637 | return false; | |
638 | } | |
6de9cd9a | 639 | |
750628d8 | 640 | /* Initialize local data structures for CCP. */ |
6de9cd9a DN |
641 | |
642 | static void | |
750628d8 | 643 | ccp_initialize (void) |
6de9cd9a | 644 | { |
750628d8 | 645 | basic_block bb; |
6de9cd9a | 646 | |
b9eae1a9 | 647 | const_val = XCNEWVEC (prop_value_t, num_ssa_names); |
6de9cd9a | 648 | |
750628d8 DN |
649 | /* Initialize simulation flags for PHI nodes and statements. */ |
650 | FOR_EACH_BB (bb) | |
6de9cd9a | 651 | { |
750628d8 | 652 | block_stmt_iterator i; |
6de9cd9a | 653 | |
750628d8 DN |
654 | for (i = bsi_start (bb); !bsi_end_p (i); bsi_next (&i)) |
655 | { | |
750628d8 | 656 | tree stmt = bsi_stmt (i); |
106dec71 | 657 | bool is_varying = surely_varying_stmt_p (stmt); |
6de9cd9a | 658 | |
106dec71 | 659 | if (is_varying) |
750628d8 | 660 | { |
0bca51f0 DN |
661 | tree def; |
662 | ssa_op_iter iter; | |
663 | ||
664 | /* If the statement will not produce a constant, mark | |
665 | all its outputs VARYING. */ | |
666 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS) | |
106dec71 ZD |
667 | { |
668 | if (is_varying) | |
669 | set_value_varying (def); | |
670 | } | |
750628d8 DN |
671 | } |
672 | ||
750628d8 DN |
673 | DONT_SIMULATE_AGAIN (stmt) = is_varying; |
674 | } | |
6de9cd9a DN |
675 | } |
676 | ||
106dec71 ZD |
677 | /* Now process PHI nodes. We never set DONT_SIMULATE_AGAIN on phi node, |
678 | since we do not know which edges are executable yet, except for | |
679 | phi nodes for virtual operands when we do not do store ccp. */ | |
750628d8 | 680 | FOR_EACH_BB (bb) |
6de9cd9a | 681 | { |
0bca51f0 | 682 | tree phi; |
750628d8 DN |
683 | |
684 | for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi)) | |
685 | { | |
106dec71 ZD |
686 | if (!do_store_ccp && !is_gimple_reg (PHI_RESULT (phi))) |
687 | DONT_SIMULATE_AGAIN (phi) = true; | |
688 | else | |
689 | DONT_SIMULATE_AGAIN (phi) = false; | |
750628d8 | 690 | } |
6de9cd9a | 691 | } |
750628d8 | 692 | } |
6de9cd9a | 693 | |
6de9cd9a | 694 | |
0bca51f0 | 695 | /* Do final substitution of propagated values, cleanup the flowgraph and |
3253eafb | 696 | free allocated storage. |
6de9cd9a | 697 | |
3253eafb JH |
698 | Return TRUE when something was optimized. */ |
699 | ||
700 | static bool | |
0bca51f0 | 701 | ccp_finalize (void) |
6de9cd9a | 702 | { |
0bca51f0 | 703 | /* Perform substitutions based on the known constant values. */ |
3253eafb | 704 | bool something_changed = substitute_and_fold (const_val, false); |
6de9cd9a | 705 | |
0bca51f0 | 706 | free (const_val); |
ed97ddc6 | 707 | const_val = NULL; |
3253eafb | 708 | return something_changed;; |
6de9cd9a DN |
709 | } |
710 | ||
711 | ||
0bca51f0 DN |
712 | /* Compute the meet operator between *VAL1 and *VAL2. Store the result |
713 | in VAL1. | |
714 | ||
715 | any M UNDEFINED = any | |
0bca51f0 DN |
716 | any M VARYING = VARYING |
717 | Ci M Cj = Ci if (i == j) | |
718 | Ci M Cj = VARYING if (i != j) | |
106dec71 | 719 | */ |
6de9cd9a DN |
720 | |
721 | static void | |
0bca51f0 | 722 | ccp_lattice_meet (prop_value_t *val1, prop_value_t *val2) |
6de9cd9a | 723 | { |
0bca51f0 | 724 | if (val1->lattice_val == UNDEFINED) |
6de9cd9a | 725 | { |
0bca51f0 DN |
726 | /* UNDEFINED M any = any */ |
727 | *val1 = *val2; | |
750628d8 | 728 | } |
0bca51f0 | 729 | else if (val2->lattice_val == UNDEFINED) |
195da47b | 730 | { |
0bca51f0 DN |
731 | /* any M UNDEFINED = any |
732 | Nothing to do. VAL1 already contains the value we want. */ | |
733 | ; | |
195da47b | 734 | } |
0bca51f0 DN |
735 | else if (val1->lattice_val == VARYING |
736 | || val2->lattice_val == VARYING) | |
750628d8 | 737 | { |
0bca51f0 DN |
738 | /* any M VARYING = VARYING. */ |
739 | val1->lattice_val = VARYING; | |
740 | val1->value = NULL_TREE; | |
741 | val1->mem_ref = NULL_TREE; | |
750628d8 | 742 | } |
0bca51f0 DN |
743 | else if (val1->lattice_val == CONSTANT |
744 | && val2->lattice_val == CONSTANT | |
745 | && simple_cst_equal (val1->value, val2->value) == 1 | |
746 | && (!do_store_ccp | |
a318e3ac SB |
747 | || (val1->mem_ref && val2->mem_ref |
748 | && operand_equal_p (val1->mem_ref, val2->mem_ref, 0)))) | |
750628d8 | 749 | { |
0bca51f0 DN |
750 | /* Ci M Cj = Ci if (i == j) |
751 | Ci M Cj = VARYING if (i != j) | |
752 | ||
753 | If these two values come from memory stores, make sure that | |
754 | they come from the same memory reference. */ | |
755 | val1->lattice_val = CONSTANT; | |
756 | val1->value = val1->value; | |
757 | val1->mem_ref = val1->mem_ref; | |
750628d8 DN |
758 | } |
759 | else | |
760 | { | |
0bca51f0 DN |
761 | /* Any other combination is VARYING. */ |
762 | val1->lattice_val = VARYING; | |
763 | val1->value = NULL_TREE; | |
764 | val1->mem_ref = NULL_TREE; | |
750628d8 | 765 | } |
6de9cd9a DN |
766 | } |
767 | ||
768 | ||
750628d8 DN |
769 | /* Loop through the PHI_NODE's parameters for BLOCK and compare their |
770 | lattice values to determine PHI_NODE's lattice value. The value of a | |
0bca51f0 | 771 | PHI node is determined calling ccp_lattice_meet with all the arguments |
750628d8 | 772 | of the PHI node that are incoming via executable edges. */ |
6de9cd9a | 773 | |
750628d8 DN |
774 | static enum ssa_prop_result |
775 | ccp_visit_phi_node (tree phi) | |
6de9cd9a | 776 | { |
750628d8 | 777 | int i; |
0bca51f0 | 778 | prop_value_t *old_val, new_val; |
6de9cd9a | 779 | |
750628d8 | 780 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6de9cd9a | 781 | { |
750628d8 DN |
782 | fprintf (dump_file, "\nVisiting PHI node: "); |
783 | print_generic_expr (dump_file, phi, dump_flags); | |
6de9cd9a | 784 | } |
6de9cd9a | 785 | |
106dec71 | 786 | old_val = get_value (PHI_RESULT (phi)); |
750628d8 DN |
787 | switch (old_val->lattice_val) |
788 | { | |
789 | case VARYING: | |
0bca51f0 | 790 | return SSA_PROP_VARYING; |
6de9cd9a | 791 | |
750628d8 DN |
792 | case CONSTANT: |
793 | new_val = *old_val; | |
794 | break; | |
6de9cd9a | 795 | |
750628d8 | 796 | case UNDEFINED: |
750628d8 | 797 | new_val.lattice_val = UNDEFINED; |
0bca51f0 DN |
798 | new_val.value = NULL_TREE; |
799 | new_val.mem_ref = NULL_TREE; | |
750628d8 | 800 | break; |
6de9cd9a | 801 | |
750628d8 | 802 | default: |
1e128c5f | 803 | gcc_unreachable (); |
750628d8 | 804 | } |
6de9cd9a | 805 | |
750628d8 DN |
806 | for (i = 0; i < PHI_NUM_ARGS (phi); i++) |
807 | { | |
0bca51f0 DN |
808 | /* Compute the meet operator over all the PHI arguments flowing |
809 | through executable edges. */ | |
750628d8 | 810 | edge e = PHI_ARG_EDGE (phi, i); |
6de9cd9a | 811 | |
750628d8 DN |
812 | if (dump_file && (dump_flags & TDF_DETAILS)) |
813 | { | |
814 | fprintf (dump_file, | |
815 | "\n Argument #%d (%d -> %d %sexecutable)\n", | |
816 | i, e->src->index, e->dest->index, | |
817 | (e->flags & EDGE_EXECUTABLE) ? "" : "not "); | |
818 | } | |
819 | ||
820 | /* If the incoming edge is executable, Compute the meet operator for | |
821 | the existing value of the PHI node and the current PHI argument. */ | |
822 | if (e->flags & EDGE_EXECUTABLE) | |
823 | { | |
0bca51f0 DN |
824 | tree arg = PHI_ARG_DEF (phi, i); |
825 | prop_value_t arg_val; | |
6de9cd9a | 826 | |
0bca51f0 | 827 | if (is_gimple_min_invariant (arg)) |
750628d8 | 828 | { |
0bca51f0 DN |
829 | arg_val.lattice_val = CONSTANT; |
830 | arg_val.value = arg; | |
831 | arg_val.mem_ref = NULL_TREE; | |
750628d8 DN |
832 | } |
833 | else | |
106dec71 | 834 | arg_val = *(get_value (arg)); |
6de9cd9a | 835 | |
0bca51f0 | 836 | ccp_lattice_meet (&new_val, &arg_val); |
6de9cd9a | 837 | |
750628d8 DN |
838 | if (dump_file && (dump_flags & TDF_DETAILS)) |
839 | { | |
840 | fprintf (dump_file, "\t"); | |
0bca51f0 DN |
841 | print_generic_expr (dump_file, arg, dump_flags); |
842 | dump_lattice_value (dump_file, "\tValue: ", arg_val); | |
750628d8 DN |
843 | fprintf (dump_file, "\n"); |
844 | } | |
6de9cd9a | 845 | |
750628d8 DN |
846 | if (new_val.lattice_val == VARYING) |
847 | break; | |
848 | } | |
849 | } | |
6de9cd9a DN |
850 | |
851 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
750628d8 DN |
852 | { |
853 | dump_lattice_value (dump_file, "\n PHI node value: ", new_val); | |
854 | fprintf (dump_file, "\n\n"); | |
855 | } | |
856 | ||
106dec71 | 857 | /* Make the transition to the new value. */ |
750628d8 DN |
858 | if (set_lattice_value (PHI_RESULT (phi), new_val)) |
859 | { | |
860 | if (new_val.lattice_val == VARYING) | |
861 | return SSA_PROP_VARYING; | |
862 | else | |
863 | return SSA_PROP_INTERESTING; | |
864 | } | |
865 | else | |
866 | return SSA_PROP_NOT_INTERESTING; | |
6de9cd9a DN |
867 | } |
868 | ||
869 | ||
750628d8 DN |
870 | /* CCP specific front-end to the non-destructive constant folding |
871 | routines. | |
6de9cd9a DN |
872 | |
873 | Attempt to simplify the RHS of STMT knowing that one or more | |
874 | operands are constants. | |
875 | ||
876 | If simplification is possible, return the simplified RHS, | |
877 | otherwise return the original RHS. */ | |
878 | ||
879 | static tree | |
880 | ccp_fold (tree stmt) | |
881 | { | |
882 | tree rhs = get_rhs (stmt); | |
883 | enum tree_code code = TREE_CODE (rhs); | |
6615c446 | 884 | enum tree_code_class kind = TREE_CODE_CLASS (code); |
6de9cd9a DN |
885 | tree retval = NULL_TREE; |
886 | ||
6de9cd9a | 887 | if (TREE_CODE (rhs) == SSA_NAME) |
0bca51f0 DN |
888 | { |
889 | /* If the RHS is an SSA_NAME, return its known constant value, | |
890 | if any. */ | |
106dec71 | 891 | return get_value (rhs)->value; |
0bca51f0 DN |
892 | } |
893 | else if (do_store_ccp && stmt_makes_single_load (stmt)) | |
894 | { | |
895 | /* If the RHS is a memory load, see if the VUSEs associated with | |
896 | it are a valid constant for that memory load. */ | |
897 | prop_value_t *val = get_value_loaded_by (stmt, const_val); | |
add9e6d3 AP |
898 | if (val && val->mem_ref) |
899 | { | |
900 | if (operand_equal_p (val->mem_ref, rhs, 0)) | |
901 | return val->value; | |
902 | ||
903 | /* If RHS is extracting REALPART_EXPR or IMAGPART_EXPR of a | |
904 | complex type with a known constant value, return it. */ | |
905 | if ((TREE_CODE (rhs) == REALPART_EXPR | |
906 | || TREE_CODE (rhs) == IMAGPART_EXPR) | |
907 | && operand_equal_p (val->mem_ref, TREE_OPERAND (rhs, 0), 0)) | |
908 | return fold_build1 (TREE_CODE (rhs), TREE_TYPE (rhs), val->value); | |
909 | } | |
910 | return NULL_TREE; | |
0bca51f0 | 911 | } |
6de9cd9a DN |
912 | |
913 | /* Unary operators. Note that we know the single operand must | |
914 | be a constant. So this should almost always return a | |
915 | simplified RHS. */ | |
6615c446 | 916 | if (kind == tcc_unary) |
6de9cd9a DN |
917 | { |
918 | /* Handle unary operators which can appear in GIMPLE form. */ | |
919 | tree op0 = TREE_OPERAND (rhs, 0); | |
920 | ||
921 | /* Simplify the operand down to a constant. */ | |
922 | if (TREE_CODE (op0) == SSA_NAME) | |
923 | { | |
106dec71 | 924 | prop_value_t *val = get_value (op0); |
6de9cd9a | 925 | if (val->lattice_val == CONSTANT) |
106dec71 | 926 | op0 = get_value (op0)->value; |
6de9cd9a DN |
927 | } |
928 | ||
16ac8575 RG |
929 | /* Conversions are useless for CCP purposes if they are |
930 | value-preserving. Thus the restrictions that | |
931 | useless_type_conversion_p places for pointer type conversions do | |
932 | not apply here. Substitution later will only substitute to | |
933 | allowed places. */ | |
078152a2 | 934 | if ((code == NOP_EXPR || code == CONVERT_EXPR) |
16ac8575 RG |
935 | && ((POINTER_TYPE_P (TREE_TYPE (rhs)) |
936 | && POINTER_TYPE_P (TREE_TYPE (op0))) | |
937 | || useless_type_conversion_p (TREE_TYPE (rhs), TREE_TYPE (op0)))) | |
078152a2 | 938 | return op0; |
615bc06a | 939 | return fold_unary (code, TREE_TYPE (rhs), op0); |
6de9cd9a DN |
940 | } |
941 | ||
942 | /* Binary and comparison operators. We know one or both of the | |
943 | operands are constants. */ | |
6615c446 JO |
944 | else if (kind == tcc_binary |
945 | || kind == tcc_comparison | |
6de9cd9a DN |
946 | || code == TRUTH_AND_EXPR |
947 | || code == TRUTH_OR_EXPR | |
948 | || code == TRUTH_XOR_EXPR) | |
949 | { | |
950 | /* Handle binary and comparison operators that can appear in | |
951 | GIMPLE form. */ | |
952 | tree op0 = TREE_OPERAND (rhs, 0); | |
953 | tree op1 = TREE_OPERAND (rhs, 1); | |
954 | ||
955 | /* Simplify the operands down to constants when appropriate. */ | |
956 | if (TREE_CODE (op0) == SSA_NAME) | |
957 | { | |
106dec71 | 958 | prop_value_t *val = get_value (op0); |
6de9cd9a | 959 | if (val->lattice_val == CONSTANT) |
0bca51f0 | 960 | op0 = val->value; |
6de9cd9a DN |
961 | } |
962 | ||
963 | if (TREE_CODE (op1) == SSA_NAME) | |
964 | { | |
106dec71 | 965 | prop_value_t *val = get_value (op1); |
6de9cd9a | 966 | if (val->lattice_val == CONSTANT) |
0bca51f0 | 967 | op1 = val->value; |
6de9cd9a DN |
968 | } |
969 | ||
615bc06a | 970 | return fold_binary (code, TREE_TYPE (rhs), op0, op1); |
6de9cd9a DN |
971 | } |
972 | ||
87e1e42b RG |
973 | else if (kind == tcc_declaration) |
974 | return get_symbol_constant_value (rhs); | |
975 | ||
976 | else if (kind == tcc_reference) | |
977 | return fold_const_aggregate_ref (rhs); | |
978 | ||
00d382a8 RG |
979 | /* Handle propagating invariant addresses into address operations. |
980 | The folding we do here matches that in tree-ssa-forwprop.c. */ | |
981 | else if (code == ADDR_EXPR) | |
982 | { | |
983 | tree *base; | |
984 | base = &TREE_OPERAND (rhs, 0); | |
985 | while (handled_component_p (*base)) | |
986 | base = &TREE_OPERAND (*base, 0); | |
987 | if (TREE_CODE (*base) == INDIRECT_REF | |
988 | && TREE_CODE (TREE_OPERAND (*base, 0)) == SSA_NAME) | |
989 | { | |
990 | prop_value_t *val = get_value (TREE_OPERAND (*base, 0)); | |
991 | if (val->lattice_val == CONSTANT | |
992 | && TREE_CODE (val->value) == ADDR_EXPR | |
993 | && useless_type_conversion_p (TREE_TYPE (TREE_OPERAND (*base, 0)), | |
994 | TREE_TYPE (val->value)) | |
995 | && useless_type_conversion_p (TREE_TYPE (*base), | |
996 | TREE_TYPE (TREE_OPERAND (val->value, 0)))) | |
997 | { | |
998 | /* We need to return a new tree, not modify the IL or share | |
999 | parts of it. So play some tricks to avoid manually | |
1000 | building it. */ | |
1001 | tree ret, save = *base; | |
1002 | *base = TREE_OPERAND (val->value, 0); | |
1003 | ret = unshare_expr (rhs); | |
1004 | recompute_tree_invariant_for_addr_expr (ret); | |
1005 | *base = save; | |
1006 | return ret; | |
1007 | } | |
1008 | } | |
1009 | } | |
1010 | ||
6de9cd9a | 1011 | /* We may be able to fold away calls to builtin functions if their |
9cf737f8 | 1012 | arguments are constants. */ |
6de9cd9a | 1013 | else if (code == CALL_EXPR |
5039610b SL |
1014 | && TREE_CODE (CALL_EXPR_FN (rhs)) == ADDR_EXPR |
1015 | && TREE_CODE (TREE_OPERAND (CALL_EXPR_FN (rhs), 0)) == FUNCTION_DECL | |
1016 | && DECL_BUILT_IN (TREE_OPERAND (CALL_EXPR_FN (rhs), 0))) | |
6de9cd9a | 1017 | { |
f47c96aa | 1018 | if (!ZERO_SSA_OPERANDS (stmt, SSA_OP_USE)) |
6de9cd9a | 1019 | { |
f47c96aa | 1020 | tree *orig, var; |
f47c96aa AM |
1021 | size_t i = 0; |
1022 | ssa_op_iter iter; | |
1023 | use_operand_p var_p; | |
6de9cd9a DN |
1024 | |
1025 | /* Preserve the original values of every operand. */ | |
858904db | 1026 | orig = XNEWVEC (tree, NUM_SSA_OPERANDS (stmt, SSA_OP_USE)); |
f47c96aa AM |
1027 | FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_USE) |
1028 | orig[i++] = var; | |
6de9cd9a DN |
1029 | |
1030 | /* Substitute operands with their values and try to fold. */ | |
0bca51f0 | 1031 | replace_uses_in (stmt, NULL, const_val); |
5039610b | 1032 | retval = fold_call_expr (rhs, false); |
6de9cd9a DN |
1033 | |
1034 | /* Restore operands to their original form. */ | |
f47c96aa AM |
1035 | i = 0; |
1036 | FOR_EACH_SSA_USE_OPERAND (var_p, stmt, iter, SSA_OP_USE) | |
1037 | SET_USE (var_p, orig[i++]); | |
6de9cd9a DN |
1038 | free (orig); |
1039 | } | |
1040 | } | |
1041 | else | |
1042 | return rhs; | |
1043 | ||
1044 | /* If we got a simplified form, see if we need to convert its type. */ | |
1045 | if (retval) | |
a32e70c3 | 1046 | return fold_convert (TREE_TYPE (rhs), retval); |
6de9cd9a DN |
1047 | |
1048 | /* No simplification was possible. */ | |
1049 | return rhs; | |
1050 | } | |
1051 | ||
1052 | ||
ae3df618 SB |
1053 | /* Return the tree representing the element referenced by T if T is an |
1054 | ARRAY_REF or COMPONENT_REF into constant aggregates. Return | |
1055 | NULL_TREE otherwise. */ | |
1056 | ||
ed97ddc6 | 1057 | tree |
ae3df618 SB |
1058 | fold_const_aggregate_ref (tree t) |
1059 | { | |
1060 | prop_value_t *value; | |
4038c495 GB |
1061 | tree base, ctor, idx, field; |
1062 | unsigned HOST_WIDE_INT cnt; | |
1063 | tree cfield, cval; | |
ae3df618 SB |
1064 | |
1065 | switch (TREE_CODE (t)) | |
1066 | { | |
1067 | case ARRAY_REF: | |
1068 | /* Get a CONSTRUCTOR. If BASE is a VAR_DECL, get its | |
1069 | DECL_INITIAL. If BASE is a nested reference into another | |
1070 | ARRAY_REF or COMPONENT_REF, make a recursive call to resolve | |
1071 | the inner reference. */ | |
1072 | base = TREE_OPERAND (t, 0); | |
1073 | switch (TREE_CODE (base)) | |
1074 | { | |
1075 | case VAR_DECL: | |
1076 | if (!TREE_READONLY (base) | |
1077 | || TREE_CODE (TREE_TYPE (base)) != ARRAY_TYPE | |
1078 | || !targetm.binds_local_p (base)) | |
1079 | return NULL_TREE; | |
1080 | ||
1081 | ctor = DECL_INITIAL (base); | |
1082 | break; | |
1083 | ||
1084 | case ARRAY_REF: | |
1085 | case COMPONENT_REF: | |
1086 | ctor = fold_const_aggregate_ref (base); | |
1087 | break; | |
1088 | ||
87e1e42b RG |
1089 | case STRING_CST: |
1090 | case CONSTRUCTOR: | |
1091 | ctor = base; | |
1092 | break; | |
1093 | ||
ae3df618 SB |
1094 | default: |
1095 | return NULL_TREE; | |
1096 | } | |
1097 | ||
1098 | if (ctor == NULL_TREE | |
faaf1436 RG |
1099 | || (TREE_CODE (ctor) != CONSTRUCTOR |
1100 | && TREE_CODE (ctor) != STRING_CST) | |
ae3df618 SB |
1101 | || !TREE_STATIC (ctor)) |
1102 | return NULL_TREE; | |
1103 | ||
1104 | /* Get the index. If we have an SSA_NAME, try to resolve it | |
1105 | with the current lattice value for the SSA_NAME. */ | |
1106 | idx = TREE_OPERAND (t, 1); | |
1107 | switch (TREE_CODE (idx)) | |
1108 | { | |
1109 | case SSA_NAME: | |
106dec71 | 1110 | if ((value = get_value (idx)) |
ae3df618 SB |
1111 | && value->lattice_val == CONSTANT |
1112 | && TREE_CODE (value->value) == INTEGER_CST) | |
1113 | idx = value->value; | |
1114 | else | |
1115 | return NULL_TREE; | |
1116 | break; | |
1117 | ||
1118 | case INTEGER_CST: | |
1119 | break; | |
1120 | ||
1121 | default: | |
1122 | return NULL_TREE; | |
1123 | } | |
1124 | ||
faaf1436 RG |
1125 | /* Fold read from constant string. */ |
1126 | if (TREE_CODE (ctor) == STRING_CST) | |
1127 | { | |
1128 | if ((TYPE_MODE (TREE_TYPE (t)) | |
1129 | == TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) | |
1130 | && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) | |
1131 | == MODE_INT) | |
1132 | && GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) == 1 | |
1133 | && compare_tree_int (idx, TREE_STRING_LENGTH (ctor)) < 0) | |
0c4d4efb DJ |
1134 | return build_int_cst_type (TREE_TYPE (t), |
1135 | (TREE_STRING_POINTER (ctor) | |
1136 | [TREE_INT_CST_LOW (idx)])); | |
faaf1436 RG |
1137 | return NULL_TREE; |
1138 | } | |
1139 | ||
ae3df618 | 1140 | /* Whoo-hoo! I'll fold ya baby. Yeah! */ |
4038c495 GB |
1141 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, cval) |
1142 | if (tree_int_cst_equal (cfield, idx)) | |
62bc00e2 RG |
1143 | { |
1144 | STRIP_USELESS_TYPE_CONVERSION (cval); | |
1145 | return cval; | |
1146 | } | |
ae3df618 SB |
1147 | break; |
1148 | ||
1149 | case COMPONENT_REF: | |
1150 | /* Get a CONSTRUCTOR. If BASE is a VAR_DECL, get its | |
1151 | DECL_INITIAL. If BASE is a nested reference into another | |
1152 | ARRAY_REF or COMPONENT_REF, make a recursive call to resolve | |
1153 | the inner reference. */ | |
1154 | base = TREE_OPERAND (t, 0); | |
1155 | switch (TREE_CODE (base)) | |
1156 | { | |
1157 | case VAR_DECL: | |
1158 | if (!TREE_READONLY (base) | |
1159 | || TREE_CODE (TREE_TYPE (base)) != RECORD_TYPE | |
1160 | || !targetm.binds_local_p (base)) | |
1161 | return NULL_TREE; | |
1162 | ||
1163 | ctor = DECL_INITIAL (base); | |
1164 | break; | |
1165 | ||
1166 | case ARRAY_REF: | |
1167 | case COMPONENT_REF: | |
1168 | ctor = fold_const_aggregate_ref (base); | |
1169 | break; | |
1170 | ||
1171 | default: | |
1172 | return NULL_TREE; | |
1173 | } | |
1174 | ||
1175 | if (ctor == NULL_TREE | |
1176 | || TREE_CODE (ctor) != CONSTRUCTOR | |
1177 | || !TREE_STATIC (ctor)) | |
1178 | return NULL_TREE; | |
1179 | ||
1180 | field = TREE_OPERAND (t, 1); | |
1181 | ||
4038c495 GB |
1182 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, cval) |
1183 | if (cfield == field | |
ae3df618 | 1184 | /* FIXME: Handle bit-fields. */ |
4038c495 | 1185 | && ! DECL_BIT_FIELD (cfield)) |
62bc00e2 RG |
1186 | { |
1187 | STRIP_USELESS_TYPE_CONVERSION (cval); | |
1188 | return cval; | |
1189 | } | |
ae3df618 SB |
1190 | break; |
1191 | ||
1ebd8d9a SB |
1192 | case REALPART_EXPR: |
1193 | case IMAGPART_EXPR: | |
1194 | { | |
1195 | tree c = fold_const_aggregate_ref (TREE_OPERAND (t, 0)); | |
1196 | if (c && TREE_CODE (c) == COMPLEX_CST) | |
1197 | return fold_build1 (TREE_CODE (t), TREE_TYPE (t), c); | |
1198 | break; | |
1199 | } | |
87e1e42b RG |
1200 | |
1201 | case INDIRECT_REF: | |
1202 | { | |
1203 | tree base = TREE_OPERAND (t, 0); | |
1204 | if (TREE_CODE (base) == SSA_NAME | |
1205 | && (value = get_value (base)) | |
1206 | && value->lattice_val == CONSTANT | |
1207 | && TREE_CODE (value->value) == ADDR_EXPR) | |
1208 | return fold_const_aggregate_ref (TREE_OPERAND (value->value, 0)); | |
1209 | break; | |
1210 | } | |
1211 | ||
ae3df618 SB |
1212 | default: |
1213 | break; | |
1214 | } | |
1215 | ||
1216 | return NULL_TREE; | |
1217 | } | |
1218 | ||
6de9cd9a DN |
1219 | /* Evaluate statement STMT. */ |
1220 | ||
0bca51f0 | 1221 | static prop_value_t |
6de9cd9a DN |
1222 | evaluate_stmt (tree stmt) |
1223 | { | |
0bca51f0 | 1224 | prop_value_t val; |
faaf1436 | 1225 | tree simplified = NULL_TREE; |
0bca51f0 | 1226 | ccp_lattice_t likelyvalue = likely_value (stmt); |
6ac01510 | 1227 | bool is_constant; |
0bca51f0 DN |
1228 | |
1229 | val.mem_ref = NULL_TREE; | |
6de9cd9a | 1230 | |
6ac01510 ILT |
1231 | fold_defer_overflow_warnings (); |
1232 | ||
6de9cd9a DN |
1233 | /* If the statement is likely to have a CONSTANT result, then try |
1234 | to fold the statement to determine the constant value. */ | |
1235 | if (likelyvalue == CONSTANT) | |
1236 | simplified = ccp_fold (stmt); | |
1237 | /* If the statement is likely to have a VARYING result, then do not | |
1238 | bother folding the statement. */ | |
87e1e42b | 1239 | else if (likelyvalue == VARYING) |
6de9cd9a | 1240 | simplified = get_rhs (stmt); |
6de9cd9a | 1241 | |
6ac01510 ILT |
1242 | is_constant = simplified && is_gimple_min_invariant (simplified); |
1243 | ||
1244 | fold_undefer_overflow_warnings (is_constant, stmt, 0); | |
1245 | ||
00d382a8 RG |
1246 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1247 | { | |
1248 | fprintf (dump_file, "which is likely "); | |
1249 | switch (likelyvalue) | |
1250 | { | |
1251 | case CONSTANT: | |
1252 | fprintf (dump_file, "CONSTANT"); | |
1253 | break; | |
1254 | case UNDEFINED: | |
1255 | fprintf (dump_file, "UNDEFINED"); | |
1256 | break; | |
1257 | case VARYING: | |
1258 | fprintf (dump_file, "VARYING"); | |
1259 | break; | |
1260 | default:; | |
1261 | } | |
1262 | fprintf (dump_file, "\n"); | |
1263 | } | |
1264 | ||
6ac01510 | 1265 | if (is_constant) |
6de9cd9a DN |
1266 | { |
1267 | /* The statement produced a constant value. */ | |
1268 | val.lattice_val = CONSTANT; | |
0bca51f0 | 1269 | val.value = simplified; |
6de9cd9a DN |
1270 | } |
1271 | else | |
1272 | { | |
1273 | /* The statement produced a nonconstant value. If the statement | |
0bca51f0 DN |
1274 | had UNDEFINED operands, then the result of the statement |
1275 | should be UNDEFINED. Otherwise, the statement is VARYING. */ | |
106dec71 | 1276 | if (likelyvalue == UNDEFINED) |
a318e3ac SB |
1277 | val.lattice_val = likelyvalue; |
1278 | else | |
1279 | val.lattice_val = VARYING; | |
1280 | ||
0bca51f0 | 1281 | val.value = NULL_TREE; |
6de9cd9a | 1282 | } |
750628d8 DN |
1283 | |
1284 | return val; | |
6de9cd9a DN |
1285 | } |
1286 | ||
1287 | ||
750628d8 | 1288 | /* Visit the assignment statement STMT. Set the value of its LHS to the |
0bca51f0 DN |
1289 | value computed by the RHS and store LHS in *OUTPUT_P. If STMT |
1290 | creates virtual definitions, set the value of each new name to that | |
1291 | of the RHS (if we can derive a constant out of the RHS). */ | |
6de9cd9a | 1292 | |
750628d8 DN |
1293 | static enum ssa_prop_result |
1294 | visit_assignment (tree stmt, tree *output_p) | |
6de9cd9a | 1295 | { |
0bca51f0 | 1296 | prop_value_t val; |
750628d8 | 1297 | tree lhs, rhs; |
0bca51f0 | 1298 | enum ssa_prop_result retval; |
6de9cd9a | 1299 | |
07beea0d AH |
1300 | lhs = GIMPLE_STMT_OPERAND (stmt, 0); |
1301 | rhs = GIMPLE_STMT_OPERAND (stmt, 1); | |
6de9cd9a | 1302 | |
750628d8 DN |
1303 | if (TREE_CODE (rhs) == SSA_NAME) |
1304 | { | |
1305 | /* For a simple copy operation, we copy the lattice values. */ | |
106dec71 | 1306 | prop_value_t *nval = get_value (rhs); |
750628d8 DN |
1307 | val = *nval; |
1308 | } | |
0bca51f0 | 1309 | else if (do_store_ccp && stmt_makes_single_load (stmt)) |
750628d8 | 1310 | { |
0bca51f0 | 1311 | /* Same as above, but the RHS is not a gimple register and yet |
106dec71 | 1312 | has a known VUSE. If STMT is loading from the same memory |
0bca51f0 DN |
1313 | location that created the SSA_NAMEs for the virtual operands, |
1314 | we can propagate the value on the RHS. */ | |
1315 | prop_value_t *nval = get_value_loaded_by (stmt, const_val); | |
1316 | ||
106dec71 ZD |
1317 | if (nval |
1318 | && nval->mem_ref | |
a318e3ac | 1319 | && operand_equal_p (nval->mem_ref, rhs, 0)) |
0bca51f0 DN |
1320 | val = *nval; |
1321 | else | |
1322 | val = evaluate_stmt (stmt); | |
750628d8 DN |
1323 | } |
1324 | else | |
9390c347 | 1325 | /* Evaluate the statement. */ |
87e1e42b | 1326 | val = evaluate_stmt (stmt); |
6de9cd9a | 1327 | |
0bca51f0 | 1328 | retval = SSA_PROP_NOT_INTERESTING; |
6de9cd9a | 1329 | |
750628d8 | 1330 | /* Set the lattice value of the statement's output. */ |
0bca51f0 | 1331 | if (TREE_CODE (lhs) == SSA_NAME) |
6de9cd9a | 1332 | { |
0bca51f0 DN |
1333 | /* If STMT is an assignment to an SSA_NAME, we only have one |
1334 | value to set. */ | |
1335 | if (set_lattice_value (lhs, val)) | |
1336 | { | |
1337 | *output_p = lhs; | |
1338 | if (val.lattice_val == VARYING) | |
1339 | retval = SSA_PROP_VARYING; | |
1340 | else | |
1341 | retval = SSA_PROP_INTERESTING; | |
1342 | } | |
6de9cd9a | 1343 | } |
0bca51f0 DN |
1344 | else if (do_store_ccp && stmt_makes_single_store (stmt)) |
1345 | { | |
38635499 DN |
1346 | /* Otherwise, set the names in VDEF operands to the new |
1347 | constant value and mark the LHS as the memory reference | |
1348 | associated with VAL. */ | |
0bca51f0 DN |
1349 | ssa_op_iter i; |
1350 | tree vdef; | |
1351 | bool changed; | |
1352 | ||
0bca51f0 | 1353 | /* Mark VAL as stored in the LHS of this assignment. */ |
106dec71 ZD |
1354 | if (val.lattice_val == CONSTANT) |
1355 | val.mem_ref = lhs; | |
0bca51f0 DN |
1356 | |
1357 | /* Set the value of every VDEF to VAL. */ | |
1358 | changed = false; | |
1359 | FOR_EACH_SSA_TREE_OPERAND (vdef, stmt, i, SSA_OP_VIRTUAL_DEFS) | |
fc9962ee ZD |
1360 | { |
1361 | /* See PR 29801. We may have VDEFs for read-only variables | |
1362 | (see the handling of unmodifiable variables in | |
1363 | add_virtual_operand); do not attempt to change their value. */ | |
1364 | if (get_symbol_constant_value (SSA_NAME_VAR (vdef)) != NULL_TREE) | |
1365 | continue; | |
1366 | ||
1367 | changed |= set_lattice_value (vdef, val); | |
1368 | } | |
0bca51f0 DN |
1369 | |
1370 | /* Note that for propagation purposes, we are only interested in | |
1371 | visiting statements that load the exact same memory reference | |
1372 | stored here. Those statements will have the exact same list | |
1373 | of virtual uses, so it is enough to set the output of this | |
1374 | statement to be its first virtual definition. */ | |
1375 | *output_p = first_vdef (stmt); | |
1376 | if (changed) | |
1377 | { | |
1378 | if (val.lattice_val == VARYING) | |
1379 | retval = SSA_PROP_VARYING; | |
1380 | else | |
1381 | retval = SSA_PROP_INTERESTING; | |
1382 | } | |
1383 | } | |
1384 | ||
1385 | return retval; | |
6de9cd9a DN |
1386 | } |
1387 | ||
6de9cd9a | 1388 | |
750628d8 DN |
1389 | /* Visit the conditional statement STMT. Return SSA_PROP_INTERESTING |
1390 | if it can determine which edge will be taken. Otherwise, return | |
1391 | SSA_PROP_VARYING. */ | |
1392 | ||
1393 | static enum ssa_prop_result | |
1394 | visit_cond_stmt (tree stmt, edge *taken_edge_p) | |
6de9cd9a | 1395 | { |
0bca51f0 | 1396 | prop_value_t val; |
750628d8 DN |
1397 | basic_block block; |
1398 | ||
1399 | block = bb_for_stmt (stmt); | |
1400 | val = evaluate_stmt (stmt); | |
1401 | ||
1402 | /* Find which edge out of the conditional block will be taken and add it | |
1403 | to the worklist. If no single edge can be determined statically, | |
1404 | return SSA_PROP_VARYING to feed all the outgoing edges to the | |
1405 | propagation engine. */ | |
0bca51f0 | 1406 | *taken_edge_p = val.value ? find_taken_edge (block, val.value) : 0; |
750628d8 DN |
1407 | if (*taken_edge_p) |
1408 | return SSA_PROP_INTERESTING; | |
1409 | else | |
1410 | return SSA_PROP_VARYING; | |
6de9cd9a DN |
1411 | } |
1412 | ||
6de9cd9a | 1413 | |
750628d8 DN |
1414 | /* Evaluate statement STMT. If the statement produces an output value and |
1415 | its evaluation changes the lattice value of its output, return | |
1416 | SSA_PROP_INTERESTING and set *OUTPUT_P to the SSA_NAME holding the | |
1417 | output value. | |
1418 | ||
1419 | If STMT is a conditional branch and we can determine its truth | |
1420 | value, set *TAKEN_EDGE_P accordingly. If STMT produces a varying | |
1421 | value, return SSA_PROP_VARYING. */ | |
6de9cd9a | 1422 | |
750628d8 DN |
1423 | static enum ssa_prop_result |
1424 | ccp_visit_stmt (tree stmt, edge *taken_edge_p, tree *output_p) | |
1425 | { | |
750628d8 DN |
1426 | tree def; |
1427 | ssa_op_iter iter; | |
6de9cd9a | 1428 | |
750628d8 | 1429 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6de9cd9a | 1430 | { |
0bca51f0 DN |
1431 | fprintf (dump_file, "\nVisiting statement:\n"); |
1432 | print_generic_stmt (dump_file, stmt, dump_flags); | |
6de9cd9a | 1433 | } |
6de9cd9a | 1434 | |
07beea0d | 1435 | if (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT) |
6de9cd9a | 1436 | { |
750628d8 DN |
1437 | /* If the statement is an assignment that produces a single |
1438 | output value, evaluate its RHS to see if the lattice value of | |
1439 | its output has changed. */ | |
1440 | return visit_assignment (stmt, output_p); | |
6de9cd9a | 1441 | } |
750628d8 | 1442 | else if (TREE_CODE (stmt) == COND_EXPR || TREE_CODE (stmt) == SWITCH_EXPR) |
6de9cd9a | 1443 | { |
750628d8 DN |
1444 | /* If STMT is a conditional branch, see if we can determine |
1445 | which branch will be taken. */ | |
1446 | return visit_cond_stmt (stmt, taken_edge_p); | |
6de9cd9a | 1447 | } |
6de9cd9a | 1448 | |
750628d8 DN |
1449 | /* Any other kind of statement is not interesting for constant |
1450 | propagation and, therefore, not worth simulating. */ | |
750628d8 DN |
1451 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1452 | fprintf (dump_file, "No interesting values produced. Marked VARYING.\n"); | |
6de9cd9a | 1453 | |
750628d8 DN |
1454 | /* Definitions made by statements other than assignments to |
1455 | SSA_NAMEs represent unknown modifications to their outputs. | |
1456 | Mark them VARYING. */ | |
0bca51f0 DN |
1457 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS) |
1458 | { | |
1459 | prop_value_t v = { VARYING, NULL_TREE, NULL_TREE }; | |
1460 | set_lattice_value (def, v); | |
1461 | } | |
6de9cd9a | 1462 | |
750628d8 DN |
1463 | return SSA_PROP_VARYING; |
1464 | } | |
6de9cd9a | 1465 | |
6de9cd9a | 1466 | |
0bca51f0 | 1467 | /* Main entry point for SSA Conditional Constant Propagation. */ |
750628d8 | 1468 | |
3253eafb | 1469 | static unsigned int |
0bca51f0 | 1470 | execute_ssa_ccp (bool store_ccp) |
750628d8 | 1471 | { |
0bca51f0 | 1472 | do_store_ccp = store_ccp; |
750628d8 DN |
1473 | ccp_initialize (); |
1474 | ssa_propagate (ccp_visit_stmt, ccp_visit_phi_node); | |
3253eafb | 1475 | if (ccp_finalize ()) |
706ca88e | 1476 | return (TODO_cleanup_cfg | TODO_update_ssa | TODO_remove_unused_locals); |
3253eafb JH |
1477 | else |
1478 | return 0; | |
6de9cd9a DN |
1479 | } |
1480 | ||
173b818d | 1481 | |
c2924966 | 1482 | static unsigned int |
0bca51f0 DN |
1483 | do_ssa_ccp (void) |
1484 | { | |
3253eafb | 1485 | return execute_ssa_ccp (false); |
0bca51f0 DN |
1486 | } |
1487 | ||
1488 | ||
173b818d | 1489 | static bool |
750628d8 | 1490 | gate_ccp (void) |
173b818d | 1491 | { |
750628d8 | 1492 | return flag_tree_ccp != 0; |
173b818d BB |
1493 | } |
1494 | ||
6de9cd9a | 1495 | |
8ddbbcae | 1496 | struct gimple_opt_pass pass_ccp = |
750628d8 | 1497 | { |
8ddbbcae JH |
1498 | { |
1499 | GIMPLE_PASS, | |
750628d8 DN |
1500 | "ccp", /* name */ |
1501 | gate_ccp, /* gate */ | |
0bca51f0 | 1502 | do_ssa_ccp, /* execute */ |
750628d8 DN |
1503 | NULL, /* sub */ |
1504 | NULL, /* next */ | |
1505 | 0, /* static_pass_number */ | |
1506 | TV_TREE_CCP, /* tv_id */ | |
7faade0f | 1507 | PROP_cfg | PROP_ssa, /* properties_required */ |
750628d8 | 1508 | 0, /* properties_provided */ |
ae07b463 | 1509 | 0, /* properties_destroyed */ |
750628d8 | 1510 | 0, /* todo_flags_start */ |
3253eafb | 1511 | TODO_dump_func | TODO_verify_ssa |
8ddbbcae JH |
1512 | | TODO_verify_stmts | TODO_ggc_collect/* todo_flags_finish */ |
1513 | } | |
750628d8 | 1514 | }; |
6de9cd9a | 1515 | |
6de9cd9a | 1516 | |
c2924966 | 1517 | static unsigned int |
0bca51f0 DN |
1518 | do_ssa_store_ccp (void) |
1519 | { | |
1520 | /* If STORE-CCP is not enabled, we just run regular CCP. */ | |
3253eafb | 1521 | return execute_ssa_ccp (flag_tree_store_ccp != 0); |
0bca51f0 DN |
1522 | } |
1523 | ||
1524 | static bool | |
1525 | gate_store_ccp (void) | |
1526 | { | |
1527 | /* STORE-CCP is enabled only with -ftree-store-ccp, but when | |
1528 | -fno-tree-store-ccp is specified, we should run regular CCP. | |
1529 | That's why the pass is enabled with either flag. */ | |
1530 | return flag_tree_store_ccp != 0 || flag_tree_ccp != 0; | |
1531 | } | |
1532 | ||
1533 | ||
8ddbbcae | 1534 | struct gimple_opt_pass pass_store_ccp = |
0bca51f0 | 1535 | { |
8ddbbcae JH |
1536 | { |
1537 | GIMPLE_PASS, | |
0bca51f0 DN |
1538 | "store_ccp", /* name */ |
1539 | gate_store_ccp, /* gate */ | |
1540 | do_ssa_store_ccp, /* execute */ | |
1541 | NULL, /* sub */ | |
1542 | NULL, /* next */ | |
1543 | 0, /* static_pass_number */ | |
1544 | TV_TREE_STORE_CCP, /* tv_id */ | |
1545 | PROP_cfg | PROP_ssa | PROP_alias, /* properties_required */ | |
1546 | 0, /* properties_provided */ | |
ae07b463 | 1547 | 0, /* properties_destroyed */ |
0bca51f0 | 1548 | 0, /* todo_flags_start */ |
3253eafb | 1549 | TODO_dump_func | TODO_verify_ssa |
8ddbbcae JH |
1550 | | TODO_verify_stmts | TODO_ggc_collect/* todo_flags_finish */ |
1551 | } | |
0bca51f0 DN |
1552 | }; |
1553 | ||
6de9cd9a DN |
1554 | /* A subroutine of fold_stmt_r. Attempts to fold *(A+O) to A[X]. |
1555 | BASE is an array type. OFFSET is a byte displacement. ORIG_TYPE | |
9cf737f8 | 1556 | is the desired result type. */ |
6de9cd9a DN |
1557 | |
1558 | static tree | |
1fd89060 RG |
1559 | maybe_fold_offset_to_array_ref (tree base, tree offset, tree orig_type, |
1560 | bool allow_negative_idx) | |
6de9cd9a | 1561 | { |
891fc5e9 | 1562 | tree min_idx, idx, idx_type, elt_offset = integer_zero_node; |
44de5aeb | 1563 | tree array_type, elt_type, elt_size; |
3097760b | 1564 | tree domain_type; |
44de5aeb RK |
1565 | |
1566 | /* If BASE is an ARRAY_REF, we can pick up another offset (this time | |
1567 | measured in units of the size of elements type) from that ARRAY_REF). | |
1568 | We can't do anything if either is variable. | |
1569 | ||
1570 | The case we handle here is *(&A[N]+O). */ | |
1571 | if (TREE_CODE (base) == ARRAY_REF) | |
1572 | { | |
1573 | tree low_bound = array_ref_low_bound (base); | |
1574 | ||
1575 | elt_offset = TREE_OPERAND (base, 1); | |
1576 | if (TREE_CODE (low_bound) != INTEGER_CST | |
1577 | || TREE_CODE (elt_offset) != INTEGER_CST) | |
1578 | return NULL_TREE; | |
1579 | ||
1580 | elt_offset = int_const_binop (MINUS_EXPR, elt_offset, low_bound, 0); | |
1581 | base = TREE_OPERAND (base, 0); | |
1582 | } | |
6de9cd9a DN |
1583 | |
1584 | /* Ignore stupid user tricks of indexing non-array variables. */ | |
1585 | array_type = TREE_TYPE (base); | |
1586 | if (TREE_CODE (array_type) != ARRAY_TYPE) | |
1587 | return NULL_TREE; | |
1588 | elt_type = TREE_TYPE (array_type); | |
f4088621 | 1589 | if (!useless_type_conversion_p (orig_type, elt_type)) |
6de9cd9a | 1590 | return NULL_TREE; |
891fc5e9 RG |
1591 | |
1592 | /* Use signed size type for intermediate computation on the index. */ | |
1593 | idx_type = signed_type_for (size_type_node); | |
1594 | ||
44de5aeb RK |
1595 | /* If OFFSET and ELT_OFFSET are zero, we don't care about the size of the |
1596 | element type (so we can use the alignment if it's not constant). | |
1597 | Otherwise, compute the offset as an index by using a division. If the | |
1598 | division isn't exact, then don't do anything. */ | |
6de9cd9a | 1599 | elt_size = TYPE_SIZE_UNIT (elt_type); |
fe9821b8 JH |
1600 | if (!elt_size) |
1601 | return NULL; | |
44de5aeb RK |
1602 | if (integer_zerop (offset)) |
1603 | { | |
1604 | if (TREE_CODE (elt_size) != INTEGER_CST) | |
1605 | elt_size = size_int (TYPE_ALIGN (elt_type)); | |
6de9cd9a | 1606 | |
891fc5e9 | 1607 | idx = build_int_cst (idx_type, 0); |
44de5aeb RK |
1608 | } |
1609 | else | |
1610 | { | |
1611 | unsigned HOST_WIDE_INT lquo, lrem; | |
1612 | HOST_WIDE_INT hquo, hrem; | |
891fc5e9 | 1613 | double_int soffset; |
44de5aeb | 1614 | |
891fc5e9 RG |
1615 | /* The final array offset should be signed, so we need |
1616 | to sign-extend the (possibly pointer) offset here | |
1617 | and use signed division. */ | |
1618 | soffset = double_int_sext (tree_to_double_int (offset), | |
1619 | TYPE_PRECISION (TREE_TYPE (offset))); | |
44de5aeb | 1620 | if (TREE_CODE (elt_size) != INTEGER_CST |
891fc5e9 RG |
1621 | || div_and_round_double (TRUNC_DIV_EXPR, 0, |
1622 | soffset.low, soffset.high, | |
44de5aeb RK |
1623 | TREE_INT_CST_LOW (elt_size), |
1624 | TREE_INT_CST_HIGH (elt_size), | |
1625 | &lquo, &hquo, &lrem, &hrem) | |
1626 | || lrem || hrem) | |
1627 | return NULL_TREE; | |
6de9cd9a | 1628 | |
891fc5e9 | 1629 | idx = build_int_cst_wide (idx_type, lquo, hquo); |
44de5aeb RK |
1630 | } |
1631 | ||
1632 | /* Assume the low bound is zero. If there is a domain type, get the | |
1633 | low bound, if any, convert the index into that type, and add the | |
1634 | low bound. */ | |
891fc5e9 | 1635 | min_idx = build_int_cst (idx_type, 0); |
3097760b JH |
1636 | domain_type = TYPE_DOMAIN (array_type); |
1637 | if (domain_type) | |
6de9cd9a | 1638 | { |
3097760b | 1639 | idx_type = domain_type; |
891fc5e9 RG |
1640 | if (TYPE_MIN_VALUE (idx_type)) |
1641 | min_idx = TYPE_MIN_VALUE (idx_type); | |
44de5aeb | 1642 | else |
891fc5e9 | 1643 | min_idx = fold_convert (idx_type, min_idx); |
44de5aeb RK |
1644 | |
1645 | if (TREE_CODE (min_idx) != INTEGER_CST) | |
1646 | return NULL_TREE; | |
1647 | ||
891fc5e9 | 1648 | elt_offset = fold_convert (idx_type, elt_offset); |
6de9cd9a DN |
1649 | } |
1650 | ||
44de5aeb RK |
1651 | if (!integer_zerop (min_idx)) |
1652 | idx = int_const_binop (PLUS_EXPR, idx, min_idx, 0); | |
1653 | if (!integer_zerop (elt_offset)) | |
1654 | idx = int_const_binop (PLUS_EXPR, idx, elt_offset, 0); | |
1655 | ||
891fc5e9 RG |
1656 | /* Make sure to possibly truncate late after offsetting. */ |
1657 | idx = fold_convert (idx_type, idx); | |
1658 | ||
3097760b | 1659 | /* We don't want to construct access past array bounds. For example |
1fd89060 RG |
1660 | char *(c[4]); |
1661 | c[3][2]; | |
1662 | should not be simplified into (*c)[14] or tree-vrp will | |
1663 | give false warnings. The same is true for | |
1664 | struct A { long x; char d[0]; } *a; | |
1665 | (char *)a - 4; | |
1666 | which should be not folded to &a->d[-8]. */ | |
1667 | if (domain_type | |
1668 | && TYPE_MAX_VALUE (domain_type) | |
3097760b JH |
1669 | && TREE_CODE (TYPE_MAX_VALUE (domain_type)) == INTEGER_CST) |
1670 | { | |
1671 | tree up_bound = TYPE_MAX_VALUE (domain_type); | |
1672 | ||
1673 | if (tree_int_cst_lt (up_bound, idx) | |
1674 | /* Accesses after the end of arrays of size 0 (gcc | |
1675 | extension) and 1 are likely intentional ("struct | |
1676 | hack"). */ | |
1677 | && compare_tree_int (up_bound, 1) > 0) | |
1678 | return NULL_TREE; | |
1679 | } | |
1fd89060 RG |
1680 | if (domain_type |
1681 | && TYPE_MIN_VALUE (domain_type)) | |
1682 | { | |
1683 | if (!allow_negative_idx | |
1684 | && TREE_CODE (TYPE_MIN_VALUE (domain_type)) == INTEGER_CST | |
1685 | && tree_int_cst_lt (idx, TYPE_MIN_VALUE (domain_type))) | |
1686 | return NULL_TREE; | |
1687 | } | |
1688 | else if (!allow_negative_idx | |
1689 | && compare_tree_int (idx, 0) < 0) | |
1690 | return NULL_TREE; | |
3097760b | 1691 | |
04d86531 | 1692 | return build4 (ARRAY_REF, elt_type, base, idx, NULL_TREE, NULL_TREE); |
6de9cd9a DN |
1693 | } |
1694 | ||
750628d8 | 1695 | |
fe9821b8 | 1696 | /* Attempt to fold *(S+O) to S.X. |
6de9cd9a DN |
1697 | BASE is a record type. OFFSET is a byte displacement. ORIG_TYPE |
1698 | is the desired result type. */ | |
6de9cd9a | 1699 | |
fe9821b8 | 1700 | static tree |
6de9cd9a DN |
1701 | maybe_fold_offset_to_component_ref (tree record_type, tree base, tree offset, |
1702 | tree orig_type, bool base_is_ptr) | |
1703 | { | |
f34fa464 | 1704 | tree f, t, field_type, tail_array_field, field_offset; |
6e6e19cb JH |
1705 | tree ret; |
1706 | tree new_base; | |
6de9cd9a DN |
1707 | |
1708 | if (TREE_CODE (record_type) != RECORD_TYPE | |
1709 | && TREE_CODE (record_type) != UNION_TYPE | |
1710 | && TREE_CODE (record_type) != QUAL_UNION_TYPE) | |
1711 | return NULL_TREE; | |
1712 | ||
1713 | /* Short-circuit silly cases. */ | |
f4088621 | 1714 | if (useless_type_conversion_p (record_type, orig_type)) |
6de9cd9a DN |
1715 | return NULL_TREE; |
1716 | ||
1717 | tail_array_field = NULL_TREE; | |
1718 | for (f = TYPE_FIELDS (record_type); f ; f = TREE_CHAIN (f)) | |
1719 | { | |
1720 | int cmp; | |
1721 | ||
1722 | if (TREE_CODE (f) != FIELD_DECL) | |
1723 | continue; | |
1724 | if (DECL_BIT_FIELD (f)) | |
1725 | continue; | |
f34fa464 | 1726 | |
fe9821b8 JH |
1727 | if (!DECL_FIELD_OFFSET (f)) |
1728 | continue; | |
f34fa464 ZD |
1729 | field_offset = byte_position (f); |
1730 | if (TREE_CODE (field_offset) != INTEGER_CST) | |
6de9cd9a DN |
1731 | continue; |
1732 | ||
1733 | /* ??? Java creates "interesting" fields for representing base classes. | |
1734 | They have no name, and have no context. With no context, we get into | |
1735 | trouble with nonoverlapping_component_refs_p. Skip them. */ | |
1736 | if (!DECL_FIELD_CONTEXT (f)) | |
1737 | continue; | |
1738 | ||
1739 | /* The previous array field isn't at the end. */ | |
1740 | tail_array_field = NULL_TREE; | |
1741 | ||
1742 | /* Check to see if this offset overlaps with the field. */ | |
f34fa464 | 1743 | cmp = tree_int_cst_compare (field_offset, offset); |
6de9cd9a DN |
1744 | if (cmp > 0) |
1745 | continue; | |
1746 | ||
1747 | field_type = TREE_TYPE (f); | |
6de9cd9a DN |
1748 | |
1749 | /* Here we exactly match the offset being checked. If the types match, | |
1750 | then we can return that field. */ | |
53dba802 | 1751 | if (cmp == 0 |
f4088621 | 1752 | && useless_type_conversion_p (orig_type, field_type)) |
6de9cd9a DN |
1753 | { |
1754 | if (base_is_ptr) | |
1755 | base = build1 (INDIRECT_REF, record_type, base); | |
b4257cfc | 1756 | t = build3 (COMPONENT_REF, field_type, base, f, NULL_TREE); |
6de9cd9a DN |
1757 | return t; |
1758 | } | |
53dba802 ZD |
1759 | |
1760 | /* Don't care about offsets into the middle of scalars. */ | |
1761 | if (!AGGREGATE_TYPE_P (field_type)) | |
1762 | continue; | |
6de9cd9a | 1763 | |
53dba802 ZD |
1764 | /* Check for array at the end of the struct. This is often |
1765 | used as for flexible array members. We should be able to | |
1766 | turn this into an array access anyway. */ | |
1767 | if (TREE_CODE (field_type) == ARRAY_TYPE) | |
1768 | tail_array_field = f; | |
1769 | ||
1770 | /* Check the end of the field against the offset. */ | |
1771 | if (!DECL_SIZE_UNIT (f) | |
1772 | || TREE_CODE (DECL_SIZE_UNIT (f)) != INTEGER_CST) | |
1773 | continue; | |
1774 | t = int_const_binop (MINUS_EXPR, offset, field_offset, 1); | |
1775 | if (!tree_int_cst_lt (t, DECL_SIZE_UNIT (f))) | |
1776 | continue; | |
6de9cd9a | 1777 | |
53dba802 ZD |
1778 | /* If we matched, then set offset to the displacement into |
1779 | this field. */ | |
6e6e19cb JH |
1780 | if (base_is_ptr) |
1781 | new_base = build1 (INDIRECT_REF, record_type, base); | |
1782 | else | |
1783 | new_base = base; | |
1784 | new_base = build3 (COMPONENT_REF, field_type, new_base, f, NULL_TREE); | |
1785 | ||
1786 | /* Recurse to possibly find the match. */ | |
1fd89060 RG |
1787 | ret = maybe_fold_offset_to_array_ref (new_base, t, orig_type, |
1788 | f == TYPE_FIELDS (record_type)); | |
6e6e19cb JH |
1789 | if (ret) |
1790 | return ret; | |
1791 | ret = maybe_fold_offset_to_component_ref (field_type, new_base, t, | |
1792 | orig_type, false); | |
1793 | if (ret) | |
1794 | return ret; | |
6de9cd9a DN |
1795 | } |
1796 | ||
1797 | if (!tail_array_field) | |
1798 | return NULL_TREE; | |
1799 | ||
1800 | f = tail_array_field; | |
1801 | field_type = TREE_TYPE (f); | |
53dba802 | 1802 | offset = int_const_binop (MINUS_EXPR, offset, byte_position (f), 1); |
6de9cd9a | 1803 | |
6de9cd9a | 1804 | /* If we get here, we've got an aggregate field, and a possibly |
1ea7e6ad | 1805 | nonzero offset into them. Recurse and hope for a valid match. */ |
6de9cd9a DN |
1806 | if (base_is_ptr) |
1807 | base = build1 (INDIRECT_REF, record_type, base); | |
b4257cfc | 1808 | base = build3 (COMPONENT_REF, field_type, base, f, NULL_TREE); |
6de9cd9a | 1809 | |
1fd89060 RG |
1810 | t = maybe_fold_offset_to_array_ref (base, offset, orig_type, |
1811 | f == TYPE_FIELDS (record_type)); | |
6de9cd9a DN |
1812 | if (t) |
1813 | return t; | |
1814 | return maybe_fold_offset_to_component_ref (field_type, base, offset, | |
1815 | orig_type, false); | |
1816 | } | |
1817 | ||
fe9821b8 JH |
1818 | /* Attempt to express (ORIG_TYPE)BASE+OFFSET as BASE->field_of_orig_type |
1819 | or BASE[index] or by combination of those. | |
1820 | ||
1821 | Before attempting the conversion strip off existing ADDR_EXPRs and | |
1822 | handled component refs. */ | |
1823 | ||
1824 | tree | |
1825 | maybe_fold_offset_to_reference (tree base, tree offset, tree orig_type) | |
1826 | { | |
1827 | tree ret; | |
1828 | tree type; | |
1829 | bool base_is_ptr = true; | |
1830 | ||
1831 | STRIP_NOPS (base); | |
1832 | if (TREE_CODE (base) == ADDR_EXPR) | |
1833 | { | |
1834 | base_is_ptr = false; | |
1835 | ||
1836 | base = TREE_OPERAND (base, 0); | |
1837 | ||
1838 | /* Handle case where existing COMPONENT_REF pick e.g. wrong field of union, | |
1839 | so it needs to be removed and new COMPONENT_REF constructed. | |
1840 | The wrong COMPONENT_REF are often constructed by folding the | |
1841 | (type *)&object within the expression (type *)&object+offset */ | |
1842 | if (handled_component_p (base) && 0) | |
1843 | { | |
1844 | HOST_WIDE_INT sub_offset, size, maxsize; | |
1845 | tree newbase; | |
1846 | newbase = get_ref_base_and_extent (base, &sub_offset, | |
1847 | &size, &maxsize); | |
1848 | gcc_assert (newbase); | |
1849 | gcc_assert (!(sub_offset & (BITS_PER_UNIT - 1))); | |
1850 | if (size == maxsize) | |
1851 | { | |
1852 | base = newbase; | |
1853 | if (sub_offset) | |
1854 | offset = int_const_binop (PLUS_EXPR, offset, | |
1855 | build_int_cst (TREE_TYPE (offset), | |
1856 | sub_offset / BITS_PER_UNIT), 1); | |
1857 | } | |
1858 | } | |
f4088621 | 1859 | if (useless_type_conversion_p (orig_type, TREE_TYPE (base)) |
fe9821b8 JH |
1860 | && integer_zerop (offset)) |
1861 | return base; | |
1862 | type = TREE_TYPE (base); | |
1863 | } | |
1864 | else | |
1865 | { | |
1866 | base_is_ptr = true; | |
1867 | if (!POINTER_TYPE_P (TREE_TYPE (base))) | |
1868 | return NULL_TREE; | |
1869 | type = TREE_TYPE (TREE_TYPE (base)); | |
1870 | } | |
1871 | ret = maybe_fold_offset_to_component_ref (type, base, offset, | |
1872 | orig_type, base_is_ptr); | |
1873 | if (!ret) | |
1874 | { | |
1875 | if (base_is_ptr) | |
1876 | base = build1 (INDIRECT_REF, type, base); | |
1fd89060 | 1877 | ret = maybe_fold_offset_to_array_ref (base, offset, orig_type, true); |
fe9821b8 JH |
1878 | } |
1879 | return ret; | |
1880 | } | |
750628d8 | 1881 | |
6de9cd9a DN |
1882 | /* A subroutine of fold_stmt_r. Attempt to simplify *(BASE+OFFSET). |
1883 | Return the simplified expression, or NULL if nothing could be done. */ | |
1884 | ||
1885 | static tree | |
1886 | maybe_fold_stmt_indirect (tree expr, tree base, tree offset) | |
1887 | { | |
1888 | tree t; | |
cbf8d355 | 1889 | bool volatile_p = TREE_THIS_VOLATILE (expr); |
6de9cd9a DN |
1890 | |
1891 | /* We may well have constructed a double-nested PLUS_EXPR via multiple | |
1892 | substitutions. Fold that down to one. Remove NON_LVALUE_EXPRs that | |
1893 | are sometimes added. */ | |
1894 | base = fold (base); | |
ff7c8597 | 1895 | STRIP_TYPE_NOPS (base); |
6de9cd9a DN |
1896 | TREE_OPERAND (expr, 0) = base; |
1897 | ||
1898 | /* One possibility is that the address reduces to a string constant. */ | |
1899 | t = fold_read_from_constant_string (expr); | |
1900 | if (t) | |
1901 | return t; | |
1902 | ||
5be014d5 AP |
1903 | /* Add in any offset from a POINTER_PLUS_EXPR. */ |
1904 | if (TREE_CODE (base) == POINTER_PLUS_EXPR) | |
6de9cd9a DN |
1905 | { |
1906 | tree offset2; | |
1907 | ||
1908 | offset2 = TREE_OPERAND (base, 1); | |
1909 | if (TREE_CODE (offset2) != INTEGER_CST) | |
1910 | return NULL_TREE; | |
1911 | base = TREE_OPERAND (base, 0); | |
1912 | ||
5be014d5 AP |
1913 | offset = fold_convert (sizetype, |
1914 | int_const_binop (PLUS_EXPR, offset, offset2, 1)); | |
6de9cd9a DN |
1915 | } |
1916 | ||
1917 | if (TREE_CODE (base) == ADDR_EXPR) | |
1918 | { | |
fe9821b8 JH |
1919 | tree base_addr = base; |
1920 | ||
6de9cd9a DN |
1921 | /* Strip the ADDR_EXPR. */ |
1922 | base = TREE_OPERAND (base, 0); | |
1923 | ||
0534fa56 RH |
1924 | /* Fold away CONST_DECL to its value, if the type is scalar. */ |
1925 | if (TREE_CODE (base) == CONST_DECL | |
1b738915 | 1926 | && is_gimple_min_invariant (DECL_INITIAL (base))) |
0534fa56 RH |
1927 | return DECL_INITIAL (base); |
1928 | ||
6de9cd9a | 1929 | /* Try folding *(&B+O) to B.X. */ |
fe9821b8 JH |
1930 | t = maybe_fold_offset_to_reference (base_addr, offset, |
1931 | TREE_TYPE (expr)); | |
6de9cd9a | 1932 | if (t) |
cbf8d355 RG |
1933 | { |
1934 | TREE_THIS_VOLATILE (t) = volatile_p; | |
1935 | return t; | |
1936 | } | |
6de9cd9a DN |
1937 | } |
1938 | else | |
1939 | { | |
1940 | /* We can get here for out-of-range string constant accesses, | |
1941 | such as "_"[3]. Bail out of the entire substitution search | |
1942 | and arrange for the entire statement to be replaced by a | |
aabcd309 | 1943 | call to __builtin_trap. In all likelihood this will all be |
6de9cd9a DN |
1944 | constant-folded away, but in the meantime we can't leave with |
1945 | something that get_expr_operands can't understand. */ | |
1946 | ||
1947 | t = base; | |
1948 | STRIP_NOPS (t); | |
1949 | if (TREE_CODE (t) == ADDR_EXPR | |
1950 | && TREE_CODE (TREE_OPERAND (t, 0)) == STRING_CST) | |
1951 | { | |
1952 | /* FIXME: Except that this causes problems elsewhere with dead | |
0e61db61 | 1953 | code not being deleted, and we die in the rtl expanders |
6de9cd9a DN |
1954 | because we failed to remove some ssa_name. In the meantime, |
1955 | just return zero. */ | |
1956 | /* FIXME2: This condition should be signaled by | |
1957 | fold_read_from_constant_string directly, rather than | |
1958 | re-checking for it here. */ | |
1959 | return integer_zero_node; | |
1960 | } | |
1961 | ||
1962 | /* Try folding *(B+O) to B->X. Still an improvement. */ | |
1963 | if (POINTER_TYPE_P (TREE_TYPE (base))) | |
1964 | { | |
fe9821b8 JH |
1965 | t = maybe_fold_offset_to_reference (base, offset, |
1966 | TREE_TYPE (expr)); | |
6de9cd9a DN |
1967 | if (t) |
1968 | return t; | |
1969 | } | |
1970 | } | |
1971 | ||
1972 | /* Otherwise we had an offset that we could not simplify. */ | |
1973 | return NULL_TREE; | |
1974 | } | |
1975 | ||
750628d8 | 1976 | |
5be014d5 | 1977 | /* A subroutine of fold_stmt_r. EXPR is a POINTER_PLUS_EXPR. |
6de9cd9a DN |
1978 | |
1979 | A quaint feature extant in our address arithmetic is that there | |
1980 | can be hidden type changes here. The type of the result need | |
1981 | not be the same as the type of the input pointer. | |
1982 | ||
1983 | What we're after here is an expression of the form | |
1984 | (T *)(&array + const) | |
1985 | where the cast doesn't actually exist, but is implicit in the | |
5be014d5 | 1986 | type of the POINTER_PLUS_EXPR. We'd like to turn this into |
6de9cd9a DN |
1987 | &array[x] |
1988 | which may be able to propagate further. */ | |
1989 | ||
1990 | static tree | |
1991 | maybe_fold_stmt_addition (tree expr) | |
1992 | { | |
1993 | tree op0 = TREE_OPERAND (expr, 0); | |
1994 | tree op1 = TREE_OPERAND (expr, 1); | |
1995 | tree ptr_type = TREE_TYPE (expr); | |
1996 | tree ptd_type; | |
1997 | tree t; | |
6de9cd9a | 1998 | |
5be014d5 AP |
1999 | gcc_assert (TREE_CODE (expr) == POINTER_PLUS_EXPR); |
2000 | ||
6de9cd9a DN |
2001 | /* It had better be a constant. */ |
2002 | if (TREE_CODE (op1) != INTEGER_CST) | |
2003 | return NULL_TREE; | |
2004 | /* The first operand should be an ADDR_EXPR. */ | |
2005 | if (TREE_CODE (op0) != ADDR_EXPR) | |
2006 | return NULL_TREE; | |
2007 | op0 = TREE_OPERAND (op0, 0); | |
2008 | ||
2009 | /* If the first operand is an ARRAY_REF, expand it so that we can fold | |
2010 | the offset into it. */ | |
2011 | while (TREE_CODE (op0) == ARRAY_REF) | |
2012 | { | |
2013 | tree array_obj = TREE_OPERAND (op0, 0); | |
2014 | tree array_idx = TREE_OPERAND (op0, 1); | |
2015 | tree elt_type = TREE_TYPE (op0); | |
2016 | tree elt_size = TYPE_SIZE_UNIT (elt_type); | |
2017 | tree min_idx; | |
2018 | ||
2019 | if (TREE_CODE (array_idx) != INTEGER_CST) | |
2020 | break; | |
2021 | if (TREE_CODE (elt_size) != INTEGER_CST) | |
2022 | break; | |
2023 | ||
2024 | /* Un-bias the index by the min index of the array type. */ | |
2025 | min_idx = TYPE_DOMAIN (TREE_TYPE (array_obj)); | |
2026 | if (min_idx) | |
2027 | { | |
2028 | min_idx = TYPE_MIN_VALUE (min_idx); | |
2029 | if (min_idx) | |
2030 | { | |
44de5aeb RK |
2031 | if (TREE_CODE (min_idx) != INTEGER_CST) |
2032 | break; | |
2033 | ||
b6f65e3c | 2034 | array_idx = fold_convert (TREE_TYPE (min_idx), array_idx); |
6de9cd9a DN |
2035 | if (!integer_zerop (min_idx)) |
2036 | array_idx = int_const_binop (MINUS_EXPR, array_idx, | |
2037 | min_idx, 0); | |
2038 | } | |
2039 | } | |
2040 | ||
2041 | /* Convert the index to a byte offset. */ | |
b6f65e3c | 2042 | array_idx = fold_convert (sizetype, array_idx); |
6de9cd9a DN |
2043 | array_idx = int_const_binop (MULT_EXPR, array_idx, elt_size, 0); |
2044 | ||
2045 | /* Update the operands for the next round, or for folding. */ | |
5be014d5 | 2046 | op1 = int_const_binop (PLUS_EXPR, |
6de9cd9a | 2047 | array_idx, op1, 0); |
6de9cd9a DN |
2048 | op0 = array_obj; |
2049 | } | |
2050 | ||
6de9cd9a | 2051 | ptd_type = TREE_TYPE (ptr_type); |
c4e5b5a8 RG |
2052 | /* If we want a pointer to void, reconstruct the reference from the |
2053 | array element type. A pointer to that can be trivially converted | |
2054 | to void *. This happens as we fold (void *)(ptr p+ off). */ | |
2055 | if (VOID_TYPE_P (ptd_type) | |
2056 | && TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE) | |
2057 | ptd_type = TREE_TYPE (TREE_TYPE (op0)); | |
6de9cd9a DN |
2058 | |
2059 | /* At which point we can try some of the same things as for indirects. */ | |
1fd89060 | 2060 | t = maybe_fold_offset_to_array_ref (op0, op1, ptd_type, true); |
6de9cd9a DN |
2061 | if (!t) |
2062 | t = maybe_fold_offset_to_component_ref (TREE_TYPE (op0), op0, op1, | |
2063 | ptd_type, false); | |
2064 | if (t) | |
2065 | t = build1 (ADDR_EXPR, ptr_type, t); | |
2066 | ||
2067 | return t; | |
2068 | } | |
2069 | ||
622f91ba JL |
2070 | /* For passing state through walk_tree into fold_stmt_r and its |
2071 | children. */ | |
2072 | ||
2073 | struct fold_stmt_r_data | |
2074 | { | |
6ac01510 ILT |
2075 | tree stmt; |
2076 | bool *changed_p; | |
2077 | bool *inside_addr_expr_p; | |
622f91ba JL |
2078 | }; |
2079 | ||
6de9cd9a DN |
2080 | /* Subroutine of fold_stmt called via walk_tree. We perform several |
2081 | simplifications of EXPR_P, mostly having to do with pointer arithmetic. */ | |
2082 | ||
2083 | static tree | |
2084 | fold_stmt_r (tree *expr_p, int *walk_subtrees, void *data) | |
2085 | { | |
858904db | 2086 | struct fold_stmt_r_data *fold_stmt_r_data = (struct fold_stmt_r_data *) data; |
622f91ba JL |
2087 | bool *inside_addr_expr_p = fold_stmt_r_data->inside_addr_expr_p; |
2088 | bool *changed_p = fold_stmt_r_data->changed_p; | |
6de9cd9a | 2089 | tree expr = *expr_p, t; |
6aaa4013 | 2090 | bool volatile_p = TREE_THIS_VOLATILE (expr); |
6de9cd9a DN |
2091 | |
2092 | /* ??? It'd be nice if walk_tree had a pre-order option. */ | |
2093 | switch (TREE_CODE (expr)) | |
2094 | { | |
2095 | case INDIRECT_REF: | |
2096 | t = walk_tree (&TREE_OPERAND (expr, 0), fold_stmt_r, data, NULL); | |
2097 | if (t) | |
2098 | return t; | |
2099 | *walk_subtrees = 0; | |
2100 | ||
2101 | t = maybe_fold_stmt_indirect (expr, TREE_OPERAND (expr, 0), | |
2102 | integer_zero_node); | |
16ac8575 RG |
2103 | if (!t |
2104 | && TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR) | |
2105 | /* If we had a good reason for propagating the address here, | |
2106 | make sure we end up with valid gimple. See PR34989. */ | |
2107 | t = TREE_OPERAND (TREE_OPERAND (expr, 0), 0); | |
6de9cd9a DN |
2108 | break; |
2109 | ||
fe9821b8 JH |
2110 | case NOP_EXPR: |
2111 | t = walk_tree (&TREE_OPERAND (expr, 0), fold_stmt_r, data, NULL); | |
2112 | if (t) | |
2113 | return t; | |
2114 | *walk_subtrees = 0; | |
2115 | ||
2116 | if (POINTER_TYPE_P (TREE_TYPE (expr)) | |
2117 | && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (expr, 0))) | |
2118 | && (t = maybe_fold_offset_to_reference | |
2119 | (TREE_OPERAND (expr, 0), | |
2120 | integer_zero_node, | |
2121 | TREE_TYPE (TREE_TYPE (expr))))) | |
fa2050d2 RG |
2122 | { |
2123 | tree ptr_type = build_pointer_type (TREE_TYPE (t)); | |
2124 | if (!useless_type_conversion_p (TREE_TYPE (expr), ptr_type)) | |
2125 | return NULL_TREE; | |
2126 | t = build_fold_addr_expr_with_type (t, ptr_type); | |
2127 | } | |
fe9821b8 JH |
2128 | break; |
2129 | ||
622f91ba | 2130 | /* ??? Could handle more ARRAY_REFs here, as a variant of INDIRECT_REF. |
6de9cd9a DN |
2131 | We'd only want to bother decomposing an existing ARRAY_REF if |
2132 | the base array is found to have another offset contained within. | |
2133 | Otherwise we'd be wasting time. */ | |
622f91ba JL |
2134 | case ARRAY_REF: |
2135 | /* If we are not processing expressions found within an | |
2136 | ADDR_EXPR, then we can fold constant array references. */ | |
2137 | if (!*inside_addr_expr_p) | |
2138 | t = fold_read_from_constant_string (expr); | |
2139 | else | |
2140 | t = NULL; | |
2141 | break; | |
6de9cd9a DN |
2142 | |
2143 | case ADDR_EXPR: | |
622f91ba | 2144 | *inside_addr_expr_p = true; |
6de9cd9a | 2145 | t = walk_tree (&TREE_OPERAND (expr, 0), fold_stmt_r, data, NULL); |
622f91ba | 2146 | *inside_addr_expr_p = false; |
6de9cd9a DN |
2147 | if (t) |
2148 | return t; | |
2149 | *walk_subtrees = 0; | |
2150 | ||
51eed280 PB |
2151 | /* Make sure the value is properly considered constant, and so gets |
2152 | propagated as expected. */ | |
6de9cd9a | 2153 | if (*changed_p) |
127203ac | 2154 | recompute_tree_invariant_for_addr_expr (expr); |
6de9cd9a DN |
2155 | return NULL_TREE; |
2156 | ||
5be014d5 | 2157 | case POINTER_PLUS_EXPR: |
6de9cd9a DN |
2158 | t = walk_tree (&TREE_OPERAND (expr, 0), fold_stmt_r, data, NULL); |
2159 | if (t) | |
2160 | return t; | |
2161 | t = walk_tree (&TREE_OPERAND (expr, 1), fold_stmt_r, data, NULL); | |
2162 | if (t) | |
2163 | return t; | |
2164 | *walk_subtrees = 0; | |
2165 | ||
2166 | t = maybe_fold_stmt_addition (expr); | |
2167 | break; | |
2168 | ||
2169 | case COMPONENT_REF: | |
2170 | t = walk_tree (&TREE_OPERAND (expr, 0), fold_stmt_r, data, NULL); | |
2171 | if (t) | |
2172 | return t; | |
2173 | *walk_subtrees = 0; | |
2174 | ||
fa27426e RH |
2175 | /* Make sure the FIELD_DECL is actually a field in the type on the lhs. |
2176 | We've already checked that the records are compatible, so we should | |
2177 | come up with a set of compatible fields. */ | |
2178 | { | |
2179 | tree expr_record = TREE_TYPE (TREE_OPERAND (expr, 0)); | |
2180 | tree expr_field = TREE_OPERAND (expr, 1); | |
2181 | ||
2182 | if (DECL_FIELD_CONTEXT (expr_field) != TYPE_MAIN_VARIANT (expr_record)) | |
2183 | { | |
2184 | expr_field = find_compatible_field (expr_record, expr_field); | |
2185 | TREE_OPERAND (expr, 1) = expr_field; | |
2186 | } | |
2187 | } | |
6de9cd9a DN |
2188 | break; |
2189 | ||
ac182688 ZD |
2190 | case TARGET_MEM_REF: |
2191 | t = maybe_fold_tmr (expr); | |
2192 | break; | |
2193 | ||
f393e7f5 RG |
2194 | case COND_EXPR: |
2195 | if (COMPARISON_CLASS_P (TREE_OPERAND (expr, 0))) | |
2196 | { | |
2197 | tree op0 = TREE_OPERAND (expr, 0); | |
6ac01510 ILT |
2198 | tree tem; |
2199 | bool set; | |
2200 | ||
2201 | fold_defer_overflow_warnings (); | |
2202 | tem = fold_binary (TREE_CODE (op0), TREE_TYPE (op0), | |
2203 | TREE_OPERAND (op0, 0), | |
2204 | TREE_OPERAND (op0, 1)); | |
2205 | set = tem && set_rhs (expr_p, tem); | |
2206 | fold_undefer_overflow_warnings (set, fold_stmt_r_data->stmt, 0); | |
2207 | if (set) | |
5cdc4a26 RS |
2208 | { |
2209 | t = *expr_p; | |
2210 | break; | |
2211 | } | |
f393e7f5 | 2212 | } |
5cdc4a26 | 2213 | return NULL_TREE; |
f393e7f5 | 2214 | |
6de9cd9a DN |
2215 | default: |
2216 | return NULL_TREE; | |
2217 | } | |
2218 | ||
2219 | if (t) | |
2220 | { | |
6aaa4013 RG |
2221 | /* Preserve volatileness of the original expression. */ |
2222 | TREE_THIS_VOLATILE (t) = volatile_p; | |
6de9cd9a DN |
2223 | *expr_p = t; |
2224 | *changed_p = true; | |
2225 | } | |
2226 | ||
2227 | return NULL_TREE; | |
2228 | } | |
2229 | ||
6de9cd9a | 2230 | |
10a0d495 JJ |
2231 | /* Return the string length, maximum string length or maximum value of |
2232 | ARG in LENGTH. | |
2233 | If ARG is an SSA name variable, follow its use-def chains. If LENGTH | |
2234 | is not NULL and, for TYPE == 0, its value is not equal to the length | |
2235 | we determine or if we are unable to determine the length or value, | |
2236 | return false. VISITED is a bitmap of visited variables. | |
2237 | TYPE is 0 if string length should be returned, 1 for maximum string | |
2238 | length and 2 for maximum value ARG can have. */ | |
6de9cd9a | 2239 | |
06a9b53f | 2240 | static bool |
10a0d495 | 2241 | get_maxval_strlen (tree arg, tree *length, bitmap visited, int type) |
6de9cd9a | 2242 | { |
750628d8 DN |
2243 | tree var, def_stmt, val; |
2244 | ||
2245 | if (TREE_CODE (arg) != SSA_NAME) | |
06a9b53f | 2246 | { |
f255541f RC |
2247 | if (TREE_CODE (arg) == COND_EXPR) |
2248 | return get_maxval_strlen (COND_EXPR_THEN (arg), length, visited, type) | |
2249 | && get_maxval_strlen (COND_EXPR_ELSE (arg), length, visited, type); | |
c4e5b5a8 RG |
2250 | /* We can end up with &(*iftmp_1)[0] here as well, so handle it. */ |
2251 | else if (TREE_CODE (arg) == ADDR_EXPR | |
2252 | && TREE_CODE (TREE_OPERAND (arg, 0)) == ARRAY_REF | |
2253 | && integer_zerop (TREE_OPERAND (TREE_OPERAND (arg, 0), 1))) | |
2254 | { | |
2255 | tree aop0 = TREE_OPERAND (TREE_OPERAND (arg, 0), 0); | |
2256 | if (TREE_CODE (aop0) == INDIRECT_REF | |
2257 | && TREE_CODE (TREE_OPERAND (aop0, 0)) == SSA_NAME) | |
2258 | return get_maxval_strlen (TREE_OPERAND (aop0, 0), | |
2259 | length, visited, type); | |
2260 | } | |
f255541f | 2261 | |
10a0d495 JJ |
2262 | if (type == 2) |
2263 | { | |
2264 | val = arg; | |
2265 | if (TREE_CODE (val) != INTEGER_CST | |
2266 | || tree_int_cst_sgn (val) < 0) | |
2267 | return false; | |
2268 | } | |
2269 | else | |
2270 | val = c_strlen (arg, 1); | |
750628d8 | 2271 | if (!val) |
06a9b53f | 2272 | return false; |
cd709752 | 2273 | |
10a0d495 JJ |
2274 | if (*length) |
2275 | { | |
2276 | if (type > 0) | |
2277 | { | |
2278 | if (TREE_CODE (*length) != INTEGER_CST | |
2279 | || TREE_CODE (val) != INTEGER_CST) | |
2280 | return false; | |
2281 | ||
2282 | if (tree_int_cst_lt (*length, val)) | |
2283 | *length = val; | |
2284 | return true; | |
2285 | } | |
2286 | else if (simple_cst_equal (val, *length) != 1) | |
2287 | return false; | |
2288 | } | |
6de9cd9a | 2289 | |
750628d8 DN |
2290 | *length = val; |
2291 | return true; | |
6de9cd9a | 2292 | } |
06a9b53f | 2293 | |
750628d8 DN |
2294 | /* If we were already here, break the infinite cycle. */ |
2295 | if (bitmap_bit_p (visited, SSA_NAME_VERSION (arg))) | |
2296 | return true; | |
2297 | bitmap_set_bit (visited, SSA_NAME_VERSION (arg)); | |
2298 | ||
2299 | var = arg; | |
2300 | def_stmt = SSA_NAME_DEF_STMT (var); | |
6de9cd9a | 2301 | |
750628d8 DN |
2302 | switch (TREE_CODE (def_stmt)) |
2303 | { | |
07beea0d | 2304 | case GIMPLE_MODIFY_STMT: |
750628d8 | 2305 | { |
10a0d495 JJ |
2306 | tree rhs; |
2307 | ||
750628d8 DN |
2308 | /* The RHS of the statement defining VAR must either have a |
2309 | constant length or come from another SSA_NAME with a constant | |
2310 | length. */ | |
07beea0d | 2311 | rhs = GIMPLE_STMT_OPERAND (def_stmt, 1); |
750628d8 | 2312 | STRIP_NOPS (rhs); |
10a0d495 | 2313 | return get_maxval_strlen (rhs, length, visited, type); |
750628d8 | 2314 | } |
6de9cd9a | 2315 | |
750628d8 DN |
2316 | case PHI_NODE: |
2317 | { | |
2318 | /* All the arguments of the PHI node must have the same constant | |
2319 | length. */ | |
2320 | int i; | |
6de9cd9a | 2321 | |
750628d8 DN |
2322 | for (i = 0; i < PHI_NUM_ARGS (def_stmt); i++) |
2323 | { | |
2324 | tree arg = PHI_ARG_DEF (def_stmt, i); | |
6de9cd9a | 2325 | |
750628d8 DN |
2326 | /* If this PHI has itself as an argument, we cannot |
2327 | determine the string length of this argument. However, | |
2328 | if we can find a constant string length for the other | |
2329 | PHI args then we can still be sure that this is a | |
2330 | constant string length. So be optimistic and just | |
2331 | continue with the next argument. */ | |
2332 | if (arg == PHI_RESULT (def_stmt)) | |
2333 | continue; | |
6de9cd9a | 2334 | |
10a0d495 | 2335 | if (!get_maxval_strlen (arg, length, visited, type)) |
750628d8 DN |
2336 | return false; |
2337 | } | |
6de9cd9a | 2338 | |
750628d8 | 2339 | return true; |
173b818d | 2340 | } |
6de9cd9a | 2341 | |
750628d8 DN |
2342 | default: |
2343 | break; | |
6de9cd9a DN |
2344 | } |
2345 | ||
750628d8 DN |
2346 | |
2347 | return false; | |
6de9cd9a DN |
2348 | } |
2349 | ||
2350 | ||
2351 | /* Fold builtin call FN in statement STMT. If it cannot be folded into a | |
2352 | constant, return NULL_TREE. Otherwise, return its constant value. */ | |
2353 | ||
2354 | static tree | |
2355 | ccp_fold_builtin (tree stmt, tree fn) | |
2356 | { | |
10a0d495 | 2357 | tree result, val[3]; |
5039610b | 2358 | tree callee, a; |
10a0d495 | 2359 | int arg_mask, i, type; |
a32e70c3 RS |
2360 | bitmap visited; |
2361 | bool ignore; | |
5039610b SL |
2362 | call_expr_arg_iterator iter; |
2363 | int nargs; | |
6de9cd9a | 2364 | |
07beea0d | 2365 | ignore = TREE_CODE (stmt) != GIMPLE_MODIFY_STMT; |
6de9cd9a DN |
2366 | |
2367 | /* First try the generic builtin folder. If that succeeds, return the | |
2368 | result directly. */ | |
5039610b | 2369 | result = fold_call_expr (fn, ignore); |
6de9cd9a | 2370 | if (result) |
10a0d495 JJ |
2371 | { |
2372 | if (ignore) | |
2373 | STRIP_NOPS (result); | |
2374 | return result; | |
2375 | } | |
a32e70c3 RS |
2376 | |
2377 | /* Ignore MD builtins. */ | |
5039610b | 2378 | callee = get_callee_fndecl (fn); |
a32e70c3 RS |
2379 | if (DECL_BUILT_IN_CLASS (callee) == BUILT_IN_MD) |
2380 | return NULL_TREE; | |
6de9cd9a DN |
2381 | |
2382 | /* If the builtin could not be folded, and it has no argument list, | |
2383 | we're done. */ | |
5039610b SL |
2384 | nargs = call_expr_nargs (fn); |
2385 | if (nargs == 0) | |
6de9cd9a DN |
2386 | return NULL_TREE; |
2387 | ||
2388 | /* Limit the work only for builtins we know how to simplify. */ | |
2389 | switch (DECL_FUNCTION_CODE (callee)) | |
2390 | { | |
2391 | case BUILT_IN_STRLEN: | |
2392 | case BUILT_IN_FPUTS: | |
2393 | case BUILT_IN_FPUTS_UNLOCKED: | |
10a0d495 JJ |
2394 | arg_mask = 1; |
2395 | type = 0; | |
6de9cd9a DN |
2396 | break; |
2397 | case BUILT_IN_STRCPY: | |
2398 | case BUILT_IN_STRNCPY: | |
10a0d495 JJ |
2399 | arg_mask = 2; |
2400 | type = 0; | |
2401 | break; | |
2402 | case BUILT_IN_MEMCPY_CHK: | |
2403 | case BUILT_IN_MEMPCPY_CHK: | |
2404 | case BUILT_IN_MEMMOVE_CHK: | |
2405 | case BUILT_IN_MEMSET_CHK: | |
2406 | case BUILT_IN_STRNCPY_CHK: | |
2407 | arg_mask = 4; | |
2408 | type = 2; | |
2409 | break; | |
2410 | case BUILT_IN_STRCPY_CHK: | |
2411 | case BUILT_IN_STPCPY_CHK: | |
2412 | arg_mask = 2; | |
2413 | type = 1; | |
2414 | break; | |
2415 | case BUILT_IN_SNPRINTF_CHK: | |
2416 | case BUILT_IN_VSNPRINTF_CHK: | |
2417 | arg_mask = 2; | |
2418 | type = 2; | |
6de9cd9a DN |
2419 | break; |
2420 | default: | |
2421 | return NULL_TREE; | |
2422 | } | |
2423 | ||
2424 | /* Try to use the dataflow information gathered by the CCP process. */ | |
8bdbfff5 | 2425 | visited = BITMAP_ALLOC (NULL); |
6de9cd9a | 2426 | |
10a0d495 | 2427 | memset (val, 0, sizeof (val)); |
5039610b SL |
2428 | init_call_expr_arg_iterator (fn, &iter); |
2429 | for (i = 0; arg_mask; i++, arg_mask >>= 1) | |
2430 | { | |
2431 | a = next_call_expr_arg (&iter); | |
2432 | if (arg_mask & 1) | |
2433 | { | |
2434 | bitmap_clear (visited); | |
2435 | if (!get_maxval_strlen (a, &val[i], visited, type)) | |
2436 | val[i] = NULL_TREE; | |
2437 | } | |
2438 | } | |
6de9cd9a | 2439 | |
8bdbfff5 | 2440 | BITMAP_FREE (visited); |
6de9cd9a | 2441 | |
a32e70c3 | 2442 | result = NULL_TREE; |
6de9cd9a DN |
2443 | switch (DECL_FUNCTION_CODE (callee)) |
2444 | { | |
2445 | case BUILT_IN_STRLEN: | |
10a0d495 | 2446 | if (val[0]) |
6de9cd9a | 2447 | { |
c22940cd | 2448 | tree new_val = fold_convert (TREE_TYPE (fn), val[0]); |
6de9cd9a DN |
2449 | |
2450 | /* If the result is not a valid gimple value, or not a cast | |
2451 | of a valid gimple value, then we can not use the result. */ | |
c22940cd TN |
2452 | if (is_gimple_val (new_val) |
2453 | || (is_gimple_cast (new_val) | |
2454 | && is_gimple_val (TREE_OPERAND (new_val, 0)))) | |
2455 | return new_val; | |
6de9cd9a | 2456 | } |
a32e70c3 RS |
2457 | break; |
2458 | ||
6de9cd9a | 2459 | case BUILT_IN_STRCPY: |
5039610b SL |
2460 | if (val[1] && is_gimple_val (val[1]) && nargs == 2) |
2461 | result = fold_builtin_strcpy (callee, | |
2462 | CALL_EXPR_ARG (fn, 0), | |
2463 | CALL_EXPR_ARG (fn, 1), | |
2464 | val[1]); | |
a32e70c3 RS |
2465 | break; |
2466 | ||
6de9cd9a | 2467 | case BUILT_IN_STRNCPY: |
5039610b SL |
2468 | if (val[1] && is_gimple_val (val[1]) && nargs == 3) |
2469 | result = fold_builtin_strncpy (callee, | |
2470 | CALL_EXPR_ARG (fn, 0), | |
2471 | CALL_EXPR_ARG (fn, 1), | |
2472 | CALL_EXPR_ARG (fn, 2), | |
2473 | val[1]); | |
a32e70c3 RS |
2474 | break; |
2475 | ||
6de9cd9a | 2476 | case BUILT_IN_FPUTS: |
5039610b SL |
2477 | result = fold_builtin_fputs (CALL_EXPR_ARG (fn, 0), |
2478 | CALL_EXPR_ARG (fn, 1), | |
07beea0d | 2479 | TREE_CODE (stmt) != GIMPLE_MODIFY_STMT, 0, |
10a0d495 | 2480 | val[0]); |
a32e70c3 RS |
2481 | break; |
2482 | ||
6de9cd9a | 2483 | case BUILT_IN_FPUTS_UNLOCKED: |
5039610b SL |
2484 | result = fold_builtin_fputs (CALL_EXPR_ARG (fn, 0), |
2485 | CALL_EXPR_ARG (fn, 1), | |
07beea0d | 2486 | TREE_CODE (stmt) != GIMPLE_MODIFY_STMT, 1, |
10a0d495 JJ |
2487 | val[0]); |
2488 | break; | |
2489 | ||
2490 | case BUILT_IN_MEMCPY_CHK: | |
2491 | case BUILT_IN_MEMPCPY_CHK: | |
2492 | case BUILT_IN_MEMMOVE_CHK: | |
2493 | case BUILT_IN_MEMSET_CHK: | |
2494 | if (val[2] && is_gimple_val (val[2])) | |
5039610b SL |
2495 | result = fold_builtin_memory_chk (callee, |
2496 | CALL_EXPR_ARG (fn, 0), | |
2497 | CALL_EXPR_ARG (fn, 1), | |
2498 | CALL_EXPR_ARG (fn, 2), | |
2499 | CALL_EXPR_ARG (fn, 3), | |
2500 | val[2], ignore, | |
10a0d495 JJ |
2501 | DECL_FUNCTION_CODE (callee)); |
2502 | break; | |
2503 | ||
2504 | case BUILT_IN_STRCPY_CHK: | |
2505 | case BUILT_IN_STPCPY_CHK: | |
2506 | if (val[1] && is_gimple_val (val[1])) | |
5039610b SL |
2507 | result = fold_builtin_stxcpy_chk (callee, |
2508 | CALL_EXPR_ARG (fn, 0), | |
2509 | CALL_EXPR_ARG (fn, 1), | |
2510 | CALL_EXPR_ARG (fn, 2), | |
2511 | val[1], ignore, | |
10a0d495 JJ |
2512 | DECL_FUNCTION_CODE (callee)); |
2513 | break; | |
2514 | ||
2515 | case BUILT_IN_STRNCPY_CHK: | |
2516 | if (val[2] && is_gimple_val (val[2])) | |
5039610b SL |
2517 | result = fold_builtin_strncpy_chk (CALL_EXPR_ARG (fn, 0), |
2518 | CALL_EXPR_ARG (fn, 1), | |
2519 | CALL_EXPR_ARG (fn, 2), | |
2520 | CALL_EXPR_ARG (fn, 3), | |
2521 | val[2]); | |
10a0d495 JJ |
2522 | break; |
2523 | ||
2524 | case BUILT_IN_SNPRINTF_CHK: | |
2525 | case BUILT_IN_VSNPRINTF_CHK: | |
2526 | if (val[1] && is_gimple_val (val[1])) | |
5039610b | 2527 | result = fold_builtin_snprintf_chk (fn, val[1], |
10a0d495 | 2528 | DECL_FUNCTION_CODE (callee)); |
a32e70c3 | 2529 | break; |
6de9cd9a DN |
2530 | |
2531 | default: | |
1e128c5f | 2532 | gcc_unreachable (); |
6de9cd9a DN |
2533 | } |
2534 | ||
a32e70c3 | 2535 | if (result && ignore) |
9675412f | 2536 | result = fold_ignored_result (result); |
a32e70c3 | 2537 | return result; |
6de9cd9a DN |
2538 | } |
2539 | ||
2540 | ||
206048bd | 2541 | /* Fold the statement pointed to by STMT_P. In some cases, this function may |
750628d8 DN |
2542 | replace the whole statement with a new one. Returns true iff folding |
2543 | makes any changes. */ | |
6de9cd9a | 2544 | |
750628d8 DN |
2545 | bool |
2546 | fold_stmt (tree *stmt_p) | |
6de9cd9a | 2547 | { |
750628d8 | 2548 | tree rhs, result, stmt; |
622f91ba | 2549 | struct fold_stmt_r_data fold_stmt_r_data; |
750628d8 | 2550 | bool changed = false; |
622f91ba JL |
2551 | bool inside_addr_expr = false; |
2552 | ||
6ac01510 ILT |
2553 | stmt = *stmt_p; |
2554 | ||
2555 | fold_stmt_r_data.stmt = stmt; | |
622f91ba JL |
2556 | fold_stmt_r_data.changed_p = &changed; |
2557 | fold_stmt_r_data.inside_addr_expr_p = &inside_addr_expr; | |
6de9cd9a | 2558 | |
750628d8 DN |
2559 | /* If we replaced constants and the statement makes pointer dereferences, |
2560 | then we may need to fold instances of *&VAR into VAR, etc. */ | |
622f91ba | 2561 | if (walk_tree (stmt_p, fold_stmt_r, &fold_stmt_r_data, NULL)) |
750628d8 | 2562 | { |
5039610b | 2563 | *stmt_p = build_call_expr (implicit_built_in_decls[BUILT_IN_TRAP], 0); |
6de9cd9a DN |
2564 | return true; |
2565 | } | |
2566 | ||
750628d8 DN |
2567 | rhs = get_rhs (stmt); |
2568 | if (!rhs) | |
2569 | return changed; | |
2570 | result = NULL_TREE; | |
6de9cd9a | 2571 | |
750628d8 | 2572 | if (TREE_CODE (rhs) == CALL_EXPR) |
6de9cd9a | 2573 | { |
750628d8 | 2574 | tree callee; |
6de9cd9a | 2575 | |
750628d8 DN |
2576 | /* Check for builtins that CCP can handle using information not |
2577 | available in the generic fold routines. */ | |
2578 | callee = get_callee_fndecl (rhs); | |
2579 | if (callee && DECL_BUILT_IN (callee)) | |
2580 | result = ccp_fold_builtin (stmt, rhs); | |
1809ff6b AP |
2581 | else |
2582 | { | |
2583 | /* Check for resolvable OBJ_TYPE_REF. The only sorts we can resolve | |
2584 | here are when we've propagated the address of a decl into the | |
2585 | object slot. */ | |
2586 | /* ??? Should perhaps do this in fold proper. However, doing it | |
2587 | there requires that we create a new CALL_EXPR, and that requires | |
2588 | copying EH region info to the new node. Easier to just do it | |
2589 | here where we can just smash the call operand. Also | |
2590 | CALL_EXPR_RETURN_SLOT_OPT needs to be handled correctly and | |
5039610b SL |
2591 | copied, fold_call_expr does not have not information. */ |
2592 | callee = CALL_EXPR_FN (rhs); | |
1809ff6b AP |
2593 | if (TREE_CODE (callee) == OBJ_TYPE_REF |
2594 | && lang_hooks.fold_obj_type_ref | |
2595 | && TREE_CODE (OBJ_TYPE_REF_OBJECT (callee)) == ADDR_EXPR | |
2596 | && DECL_P (TREE_OPERAND | |
2597 | (OBJ_TYPE_REF_OBJECT (callee), 0))) | |
2598 | { | |
2599 | tree t; | |
2600 | ||
2601 | /* ??? Caution: Broken ADDR_EXPR semantics means that | |
2602 | looking at the type of the operand of the addr_expr | |
2603 | can yield an array type. See silly exception in | |
2604 | check_pointer_types_r. */ | |
2605 | ||
2606 | t = TREE_TYPE (TREE_TYPE (OBJ_TYPE_REF_OBJECT (callee))); | |
2607 | t = lang_hooks.fold_obj_type_ref (callee, t); | |
2608 | if (t) | |
2609 | { | |
5039610b | 2610 | CALL_EXPR_FN (rhs) = t; |
1809ff6b AP |
2611 | changed = true; |
2612 | } | |
2613 | } | |
2614 | } | |
6de9cd9a | 2615 | } |
f255541f RC |
2616 | else if (TREE_CODE (rhs) == COND_EXPR) |
2617 | { | |
2618 | tree temp = fold (COND_EXPR_COND (rhs)); | |
2619 | if (temp != COND_EXPR_COND (rhs)) | |
2620 | result = fold_build3 (COND_EXPR, TREE_TYPE (rhs), temp, | |
2621 | COND_EXPR_THEN (rhs), COND_EXPR_ELSE (rhs)); | |
2622 | } | |
6de9cd9a | 2623 | |
750628d8 DN |
2624 | /* If we couldn't fold the RHS, hand over to the generic fold routines. */ |
2625 | if (result == NULL_TREE) | |
2626 | result = fold (rhs); | |
6de9cd9a | 2627 | |
750628d8 DN |
2628 | /* Strip away useless type conversions. Both the NON_LVALUE_EXPR that |
2629 | may have been added by fold, and "useless" type conversions that might | |
2630 | now be apparent due to propagation. */ | |
2631 | STRIP_USELESS_TYPE_CONVERSION (result); | |
2632 | ||
2633 | if (result != rhs) | |
2634 | changed |= set_rhs (stmt_p, result); | |
2635 | ||
2636 | return changed; | |
6de9cd9a DN |
2637 | } |
2638 | ||
38965eb2 ZD |
2639 | /* Perform the minimal folding on statement STMT. Only operations like |
2640 | *&x created by constant propagation are handled. The statement cannot | |
2641 | be replaced with a new one. */ | |
2642 | ||
2643 | bool | |
2644 | fold_stmt_inplace (tree stmt) | |
2645 | { | |
2646 | tree old_stmt = stmt, rhs, new_rhs; | |
622f91ba | 2647 | struct fold_stmt_r_data fold_stmt_r_data; |
38965eb2 | 2648 | bool changed = false; |
622f91ba JL |
2649 | bool inside_addr_expr = false; |
2650 | ||
6ac01510 | 2651 | fold_stmt_r_data.stmt = stmt; |
622f91ba JL |
2652 | fold_stmt_r_data.changed_p = &changed; |
2653 | fold_stmt_r_data.inside_addr_expr_p = &inside_addr_expr; | |
38965eb2 | 2654 | |
622f91ba | 2655 | walk_tree (&stmt, fold_stmt_r, &fold_stmt_r_data, NULL); |
38965eb2 ZD |
2656 | gcc_assert (stmt == old_stmt); |
2657 | ||
2658 | rhs = get_rhs (stmt); | |
2659 | if (!rhs || rhs == stmt) | |
2660 | return changed; | |
2661 | ||
2662 | new_rhs = fold (rhs); | |
43e364dd | 2663 | STRIP_USELESS_TYPE_CONVERSION (new_rhs); |
38965eb2 ZD |
2664 | if (new_rhs == rhs) |
2665 | return changed; | |
2666 | ||
2667 | changed |= set_rhs (&stmt, new_rhs); | |
2668 | gcc_assert (stmt == old_stmt); | |
2669 | ||
2670 | return changed; | |
2671 | } | |
6de9cd9a | 2672 | \f |
cb8e078d JJ |
2673 | /* Try to optimize out __builtin_stack_restore. Optimize it out |
2674 | if there is another __builtin_stack_restore in the same basic | |
2675 | block and no calls or ASM_EXPRs are in between, or if this block's | |
2676 | only outgoing edge is to EXIT_BLOCK and there are no calls or | |
2677 | ASM_EXPRs after this __builtin_stack_restore. */ | |
2678 | ||
2679 | static tree | |
2680 | optimize_stack_restore (basic_block bb, tree call, block_stmt_iterator i) | |
2681 | { | |
2682 | tree stack_save, stmt, callee; | |
2683 | ||
2684 | if (TREE_CODE (call) != CALL_EXPR | |
2685 | || call_expr_nargs (call) != 1 | |
2686 | || TREE_CODE (CALL_EXPR_ARG (call, 0)) != SSA_NAME | |
2687 | || !POINTER_TYPE_P (TREE_TYPE (CALL_EXPR_ARG (call, 0)))) | |
2688 | return NULL_TREE; | |
2689 | ||
2690 | for (bsi_next (&i); !bsi_end_p (i); bsi_next (&i)) | |
2691 | { | |
2692 | tree call; | |
2693 | ||
2694 | stmt = bsi_stmt (i); | |
2695 | if (TREE_CODE (stmt) == ASM_EXPR) | |
2696 | return NULL_TREE; | |
2697 | call = get_call_expr_in (stmt); | |
2698 | if (call == NULL) | |
2699 | continue; | |
2700 | ||
2701 | callee = get_callee_fndecl (call); | |
2702 | if (!callee || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL) | |
2703 | return NULL_TREE; | |
2704 | ||
2705 | if (DECL_FUNCTION_CODE (callee) == BUILT_IN_STACK_RESTORE) | |
2706 | break; | |
2707 | } | |
2708 | ||
2709 | if (bsi_end_p (i) | |
2710 | && (! single_succ_p (bb) | |
2711 | || single_succ_edge (bb)->dest != EXIT_BLOCK_PTR)) | |
2712 | return NULL_TREE; | |
2713 | ||
2714 | stack_save = SSA_NAME_DEF_STMT (CALL_EXPR_ARG (call, 0)); | |
2715 | if (TREE_CODE (stack_save) != GIMPLE_MODIFY_STMT | |
2716 | || GIMPLE_STMT_OPERAND (stack_save, 0) != CALL_EXPR_ARG (call, 0) | |
2717 | || TREE_CODE (GIMPLE_STMT_OPERAND (stack_save, 1)) != CALL_EXPR | |
2718 | || tree_could_throw_p (stack_save) | |
2719 | || !has_single_use (CALL_EXPR_ARG (call, 0))) | |
2720 | return NULL_TREE; | |
2721 | ||
2722 | callee = get_callee_fndecl (GIMPLE_STMT_OPERAND (stack_save, 1)); | |
2723 | if (!callee | |
2724 | || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL | |
2725 | || DECL_FUNCTION_CODE (callee) != BUILT_IN_STACK_SAVE | |
2726 | || call_expr_nargs (GIMPLE_STMT_OPERAND (stack_save, 1)) != 0) | |
2727 | return NULL_TREE; | |
2728 | ||
2729 | stmt = stack_save; | |
2730 | push_stmt_changes (&stmt); | |
2731 | if (!set_rhs (&stmt, | |
2732 | build_int_cst (TREE_TYPE (CALL_EXPR_ARG (call, 0)), 0))) | |
2733 | { | |
2734 | discard_stmt_changes (&stmt); | |
2735 | return NULL_TREE; | |
2736 | } | |
2737 | gcc_assert (stmt == stack_save); | |
2738 | pop_stmt_changes (&stmt); | |
2739 | ||
2740 | return integer_zero_node; | |
2741 | } | |
2742 | \f | |
d7bd8aeb JJ |
2743 | /* If va_list type is a simple pointer and nothing special is needed, |
2744 | optimize __builtin_va_start (&ap, 0) into ap = __builtin_next_arg (0), | |
2745 | __builtin_va_end (&ap) out as NOP and __builtin_va_copy into a simple | |
2746 | pointer assignment. */ | |
2747 | ||
2748 | static tree | |
2749 | optimize_stdarg_builtin (tree call) | |
2750 | { | |
1d79e31d | 2751 | tree callee, lhs, rhs; |
d7bd8aeb JJ |
2752 | bool va_list_simple_ptr; |
2753 | ||
2754 | if (TREE_CODE (call) != CALL_EXPR) | |
2755 | return NULL_TREE; | |
2756 | ||
1d79e31d KT |
2757 | va_list_simple_ptr = POINTER_TYPE_P (va_list_type_node) |
2758 | && (TREE_TYPE (va_list_type_node) == void_type_node | |
2759 | || TREE_TYPE (va_list_type_node) == char_type_node); | |
0b4b69ef | 2760 | |
1d79e31d | 2761 | callee = get_callee_fndecl (call); |
d7bd8aeb JJ |
2762 | switch (DECL_FUNCTION_CODE (callee)) |
2763 | { | |
2764 | case BUILT_IN_VA_START: | |
2765 | if (!va_list_simple_ptr | |
2766 | || targetm.expand_builtin_va_start != NULL | |
2767 | || built_in_decls[BUILT_IN_NEXT_ARG] == NULL) | |
2768 | return NULL_TREE; | |
2769 | ||
2770 | if (call_expr_nargs (call) != 2) | |
2771 | return NULL_TREE; | |
2772 | ||
2773 | lhs = CALL_EXPR_ARG (call, 0); | |
2774 | if (!POINTER_TYPE_P (TREE_TYPE (lhs)) | |
2775 | || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs))) | |
1d79e31d | 2776 | != TYPE_MAIN_VARIANT (va_list_type_node)) |
d7bd8aeb JJ |
2777 | return NULL_TREE; |
2778 | ||
2779 | lhs = build_fold_indirect_ref (lhs); | |
2780 | rhs = build_call_expr (built_in_decls[BUILT_IN_NEXT_ARG], | |
2781 | 1, integer_zero_node); | |
2782 | rhs = fold_convert (TREE_TYPE (lhs), rhs); | |
2783 | return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs); | |
2784 | ||
2785 | case BUILT_IN_VA_COPY: | |
2786 | if (!va_list_simple_ptr) | |
2787 | return NULL_TREE; | |
2788 | ||
2789 | if (call_expr_nargs (call) != 2) | |
2790 | return NULL_TREE; | |
2791 | ||
2792 | lhs = CALL_EXPR_ARG (call, 0); | |
2793 | if (!POINTER_TYPE_P (TREE_TYPE (lhs)) | |
2794 | || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs))) | |
1d79e31d | 2795 | != TYPE_MAIN_VARIANT (va_list_type_node)) |
d7bd8aeb JJ |
2796 | return NULL_TREE; |
2797 | ||
2798 | lhs = build_fold_indirect_ref (lhs); | |
2799 | rhs = CALL_EXPR_ARG (call, 1); | |
2800 | if (TYPE_MAIN_VARIANT (TREE_TYPE (rhs)) | |
1d79e31d | 2801 | != TYPE_MAIN_VARIANT (va_list_type_node)) |
d7bd8aeb JJ |
2802 | return NULL_TREE; |
2803 | ||
2804 | rhs = fold_convert (TREE_TYPE (lhs), rhs); | |
2805 | return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs); | |
2806 | ||
2807 | case BUILT_IN_VA_END: | |
2808 | return integer_zero_node; | |
2809 | ||
2810 | default: | |
2811 | gcc_unreachable (); | |
2812 | } | |
2813 | } | |
2814 | \f | |
b28b1600 JJ |
2815 | /* Convert EXPR into a GIMPLE value suitable for substitution on the |
2816 | RHS of an assignment. Insert the necessary statements before | |
2e929cf3 JH |
2817 | iterator *SI_P. |
2818 | When IGNORE is set, don't worry about the return value. */ | |
b28b1600 JJ |
2819 | |
2820 | static tree | |
2e929cf3 | 2821 | convert_to_gimple_builtin (block_stmt_iterator *si_p, tree expr, bool ignore) |
b28b1600 JJ |
2822 | { |
2823 | tree_stmt_iterator ti; | |
2824 | tree stmt = bsi_stmt (*si_p); | |
2825 | tree tmp, stmts = NULL; | |
2826 | ||
2827 | push_gimplify_context (); | |
2e929cf3 JH |
2828 | if (ignore) |
2829 | { | |
2830 | tmp = build_empty_stmt (); | |
2831 | gimplify_and_add (expr, &stmts); | |
2832 | } | |
2833 | else | |
2834 | tmp = get_initialized_tmp_var (expr, &stmts, NULL); | |
b28b1600 JJ |
2835 | pop_gimplify_context (NULL); |
2836 | ||
f47c96aa AM |
2837 | if (EXPR_HAS_LOCATION (stmt)) |
2838 | annotate_all_with_locus (&stmts, EXPR_LOCATION (stmt)); | |
2839 | ||
b28b1600 JJ |
2840 | /* The replacement can expose previously unreferenced variables. */ |
2841 | for (ti = tsi_start (stmts); !tsi_end_p (ti); tsi_next (&ti)) | |
2842 | { | |
f47c96aa | 2843 | tree new_stmt = tsi_stmt (ti); |
b28b1600 | 2844 | find_new_referenced_vars (tsi_stmt_ptr (ti)); |
f47c96aa | 2845 | bsi_insert_before (si_p, new_stmt, BSI_NEW_STMT); |
cfaab3a9 | 2846 | mark_symbols_for_renaming (new_stmt); |
f47c96aa | 2847 | bsi_next (si_p); |
b28b1600 JJ |
2848 | } |
2849 | ||
b28b1600 JJ |
2850 | return tmp; |
2851 | } | |
2852 | ||
2853 | ||
6de9cd9a DN |
2854 | /* A simple pass that attempts to fold all builtin functions. This pass |
2855 | is run after we've propagated as many constants as we can. */ | |
2856 | ||
c2924966 | 2857 | static unsigned int |
6de9cd9a DN |
2858 | execute_fold_all_builtins (void) |
2859 | { | |
a7d6ba24 | 2860 | bool cfg_changed = false; |
6de9cd9a | 2861 | basic_block bb; |
7b0e48fb DB |
2862 | unsigned int todoflags = 0; |
2863 | ||
6de9cd9a DN |
2864 | FOR_EACH_BB (bb) |
2865 | { | |
2866 | block_stmt_iterator i; | |
10a0d495 | 2867 | for (i = bsi_start (bb); !bsi_end_p (i); ) |
6de9cd9a DN |
2868 | { |
2869 | tree *stmtp = bsi_stmt_ptr (i); | |
af47810a | 2870 | tree old_stmt = *stmtp; |
6de9cd9a DN |
2871 | tree call = get_rhs (*stmtp); |
2872 | tree callee, result; | |
10a0d495 | 2873 | enum built_in_function fcode; |
6de9cd9a DN |
2874 | |
2875 | if (!call || TREE_CODE (call) != CALL_EXPR) | |
10a0d495 JJ |
2876 | { |
2877 | bsi_next (&i); | |
2878 | continue; | |
2879 | } | |
6de9cd9a DN |
2880 | callee = get_callee_fndecl (call); |
2881 | if (!callee || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL) | |
10a0d495 JJ |
2882 | { |
2883 | bsi_next (&i); | |
2884 | continue; | |
2885 | } | |
2886 | fcode = DECL_FUNCTION_CODE (callee); | |
6de9cd9a DN |
2887 | |
2888 | result = ccp_fold_builtin (*stmtp, call); | |
53a8f709 UB |
2889 | |
2890 | if (result) | |
2891 | gimple_remove_stmt_histograms (cfun, *stmtp); | |
2892 | ||
6de9cd9a DN |
2893 | if (!result) |
2894 | switch (DECL_FUNCTION_CODE (callee)) | |
2895 | { | |
2896 | case BUILT_IN_CONSTANT_P: | |
2897 | /* Resolve __builtin_constant_p. If it hasn't been | |
2898 | folded to integer_one_node by now, it's fairly | |
2899 | certain that the value simply isn't constant. */ | |
2900 | result = integer_zero_node; | |
2901 | break; | |
2902 | ||
cb8e078d JJ |
2903 | case BUILT_IN_STACK_RESTORE: |
2904 | result = optimize_stack_restore (bb, *stmtp, i); | |
d7bd8aeb JJ |
2905 | if (result) |
2906 | break; | |
2907 | bsi_next (&i); | |
2908 | continue; | |
2909 | ||
2910 | case BUILT_IN_VA_START: | |
2911 | case BUILT_IN_VA_END: | |
2912 | case BUILT_IN_VA_COPY: | |
2913 | /* These shouldn't be folded before pass_stdarg. */ | |
2914 | result = optimize_stdarg_builtin (*stmtp); | |
cb8e078d JJ |
2915 | if (result) |
2916 | break; | |
2917 | /* FALLTHRU */ | |
2918 | ||
6de9cd9a | 2919 | default: |
10a0d495 | 2920 | bsi_next (&i); |
6de9cd9a DN |
2921 | continue; |
2922 | } | |
2923 | ||
2924 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2925 | { | |
2926 | fprintf (dump_file, "Simplified\n "); | |
2927 | print_generic_stmt (dump_file, *stmtp, dump_flags); | |
2928 | } | |
2929 | ||
cfaab3a9 DN |
2930 | push_stmt_changes (stmtp); |
2931 | ||
b28b1600 JJ |
2932 | if (!set_rhs (stmtp, result)) |
2933 | { | |
2e929cf3 JH |
2934 | result = convert_to_gimple_builtin (&i, result, |
2935 | TREE_CODE (old_stmt) | |
07beea0d | 2936 | != GIMPLE_MODIFY_STMT); |
e16acfcd NS |
2937 | if (result) |
2938 | { | |
2939 | bool ok = set_rhs (stmtp, result); | |
e16acfcd | 2940 | gcc_assert (ok); |
7b0e48fb | 2941 | todoflags |= TODO_rebuild_alias; |
e16acfcd | 2942 | } |
b28b1600 | 2943 | } |
cfaab3a9 DN |
2944 | |
2945 | pop_stmt_changes (stmtp); | |
2946 | ||
af47810a | 2947 | if (maybe_clean_or_replace_eh_stmt (old_stmt, *stmtp) |
a7d6ba24 JJ |
2948 | && tree_purge_dead_eh_edges (bb)) |
2949 | cfg_changed = true; | |
6de9cd9a DN |
2950 | |
2951 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2952 | { | |
2953 | fprintf (dump_file, "to\n "); | |
2954 | print_generic_stmt (dump_file, *stmtp, dump_flags); | |
2955 | fprintf (dump_file, "\n"); | |
2956 | } | |
10a0d495 JJ |
2957 | |
2958 | /* Retry the same statement if it changed into another | |
2959 | builtin, there might be new opportunities now. */ | |
2960 | call = get_rhs (*stmtp); | |
2961 | if (!call || TREE_CODE (call) != CALL_EXPR) | |
2962 | { | |
2963 | bsi_next (&i); | |
2964 | continue; | |
2965 | } | |
2966 | callee = get_callee_fndecl (call); | |
2967 | if (!callee | |
2968 | || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL | |
2969 | || DECL_FUNCTION_CODE (callee) == fcode) | |
2970 | bsi_next (&i); | |
6de9cd9a DN |
2971 | } |
2972 | } | |
7b0e48fb | 2973 | |
a7d6ba24 | 2974 | /* Delete unreachable blocks. */ |
7b0e48fb DB |
2975 | if (cfg_changed) |
2976 | todoflags |= TODO_cleanup_cfg; | |
2977 | ||
2978 | return todoflags; | |
6de9cd9a DN |
2979 | } |
2980 | ||
750628d8 | 2981 | |
8ddbbcae | 2982 | struct gimple_opt_pass pass_fold_builtins = |
6de9cd9a | 2983 | { |
8ddbbcae JH |
2984 | { |
2985 | GIMPLE_PASS, | |
6de9cd9a DN |
2986 | "fab", /* name */ |
2987 | NULL, /* gate */ | |
2988 | execute_fold_all_builtins, /* execute */ | |
2989 | NULL, /* sub */ | |
2990 | NULL, /* next */ | |
2991 | 0, /* static_pass_number */ | |
2992 | 0, /* tv_id */ | |
7faade0f | 2993 | PROP_cfg | PROP_ssa, /* properties_required */ |
6de9cd9a DN |
2994 | 0, /* properties_provided */ |
2995 | 0, /* properties_destroyed */ | |
2996 | 0, /* todo_flags_start */ | |
b28b1600 JJ |
2997 | TODO_dump_func |
2998 | | TODO_verify_ssa | |
8ddbbcae JH |
2999 | | TODO_update_ssa /* todo_flags_finish */ |
3000 | } | |
6de9cd9a | 3001 | }; |