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6de9cd9a | 1 | /* Conditional constant propagation pass for the GNU compiler. |
6ac01510 | 2 | Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 |
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 DN |
206 | #include "tree-ssa-propagate.h" |
207 | #include "langhooks.h" | |
ae3df618 | 208 | #include "target.h" |
6ac01510 | 209 | #include "toplev.h" |
6de9cd9a DN |
210 | |
211 | ||
212 | /* Possible lattice values. */ | |
213 | typedef enum | |
214 | { | |
106dec71 | 215 | UNINITIALIZED, |
6de9cd9a DN |
216 | UNDEFINED, |
217 | CONSTANT, | |
218 | VARYING | |
0bca51f0 | 219 | } ccp_lattice_t; |
6de9cd9a | 220 | |
0bca51f0 DN |
221 | /* Array of propagated constant values. After propagation, |
222 | CONST_VAL[I].VALUE holds the constant value for SSA_NAME(I). If | |
223 | the constant is held in an SSA name representing a memory store | |
38635499 DN |
224 | (i.e., a VDEF), CONST_VAL[I].MEM_REF will contain the actual |
225 | memory reference used to store (i.e., the LHS of the assignment | |
226 | doing the store). */ | |
404f4351 | 227 | static prop_value_t *const_val; |
6de9cd9a | 228 | |
0bca51f0 DN |
229 | /* True if we are also propagating constants in stores and loads. */ |
230 | static bool do_store_ccp; | |
6de9cd9a | 231 | |
0bca51f0 | 232 | /* Dump constant propagation value VAL to file OUTF prefixed by PREFIX. */ |
95eec0d6 DB |
233 | |
234 | static void | |
0bca51f0 | 235 | dump_lattice_value (FILE *outf, const char *prefix, prop_value_t val) |
95eec0d6 | 236 | { |
750628d8 | 237 | switch (val.lattice_val) |
95eec0d6 | 238 | { |
0bca51f0 DN |
239 | case UNINITIALIZED: |
240 | fprintf (outf, "%sUNINITIALIZED", prefix); | |
241 | break; | |
750628d8 DN |
242 | case UNDEFINED: |
243 | fprintf (outf, "%sUNDEFINED", prefix); | |
244 | break; | |
245 | case VARYING: | |
246 | fprintf (outf, "%sVARYING", prefix); | |
247 | break; | |
750628d8 DN |
248 | case CONSTANT: |
249 | fprintf (outf, "%sCONSTANT ", prefix); | |
0bca51f0 | 250 | print_generic_expr (outf, val.value, dump_flags); |
750628d8 DN |
251 | break; |
252 | default: | |
1e128c5f | 253 | gcc_unreachable (); |
750628d8 | 254 | } |
95eec0d6 | 255 | } |
6de9cd9a | 256 | |
6de9cd9a | 257 | |
0bca51f0 DN |
258 | /* Print lattice value VAL to stderr. */ |
259 | ||
260 | void debug_lattice_value (prop_value_t val); | |
261 | ||
262 | void | |
263 | debug_lattice_value (prop_value_t val) | |
264 | { | |
265 | dump_lattice_value (stderr, "", val); | |
266 | fprintf (stderr, "\n"); | |
267 | } | |
6de9cd9a | 268 | |
6de9cd9a | 269 | |
688e936d RH |
270 | /* The regular is_gimple_min_invariant does a shallow test of the object. |
271 | It assumes that full gimplification has happened, or will happen on the | |
272 | object. For a value coming from DECL_INITIAL, this is not true, so we | |
6416ae7f | 273 | have to be more strict ourselves. */ |
688e936d RH |
274 | |
275 | static bool | |
276 | ccp_decl_initial_min_invariant (tree t) | |
277 | { | |
278 | if (!is_gimple_min_invariant (t)) | |
279 | return false; | |
280 | if (TREE_CODE (t) == ADDR_EXPR) | |
281 | { | |
282 | /* Inline and unroll is_gimple_addressable. */ | |
283 | while (1) | |
284 | { | |
285 | t = TREE_OPERAND (t, 0); | |
286 | if (is_gimple_id (t)) | |
287 | return true; | |
288 | if (!handled_component_p (t)) | |
289 | return false; | |
290 | } | |
291 | } | |
292 | return true; | |
293 | } | |
294 | ||
fc9962ee ZD |
295 | /* If SYM is a constant variable with known value, return the value. |
296 | NULL_TREE is returned otherwise. */ | |
297 | ||
298 | static tree | |
299 | get_symbol_constant_value (tree sym) | |
300 | { | |
301 | if (TREE_STATIC (sym) | |
302 | && TREE_READONLY (sym) | |
725c2d32 L |
303 | && !MTAG_P (sym) |
304 | /* Check if a read-only definition may be overridden at | |
305 | link and run time. */ | |
306 | && targetm.binds_local_p (sym)) | |
fc9962ee ZD |
307 | { |
308 | tree val = DECL_INITIAL (sym); | |
309 | if (val | |
310 | && ccp_decl_initial_min_invariant (val)) | |
311 | return val; | |
b0940154 AP |
312 | /* Variables declared 'const' without an initializer |
313 | have zero as the intializer. */ | |
314 | if (!val | |
315 | && (INTEGRAL_TYPE_P (TREE_TYPE (sym)) | |
316 | || SCALAR_FLOAT_TYPE_P (TREE_TYPE (sym)))) | |
317 | return fold_convert (TREE_TYPE (sym), integer_zero_node); | |
fc9962ee ZD |
318 | } |
319 | ||
320 | return NULL_TREE; | |
321 | } | |
688e936d | 322 | |
0bca51f0 DN |
323 | /* Compute a default value for variable VAR and store it in the |
324 | CONST_VAL array. The following rules are used to get default | |
325 | values: | |
95eec0d6 | 326 | |
0bca51f0 DN |
327 | 1- Global and static variables that are declared constant are |
328 | considered CONSTANT. | |
329 | ||
330 | 2- Any other value is considered UNDEFINED. This is useful when | |
750628d8 DN |
331 | considering PHI nodes. PHI arguments that are undefined do not |
332 | change the constant value of the PHI node, which allows for more | |
0bca51f0 | 333 | constants to be propagated. |
6de9cd9a | 334 | |
0bca51f0 DN |
335 | 3- If SSA_NAME_VALUE is set and it is a constant, its value is |
336 | used. | |
6de9cd9a | 337 | |
0bca51f0 DN |
338 | 4- Variables defined by statements other than assignments and PHI |
339 | nodes are considered VARYING. | |
6de9cd9a | 340 | |
106dec71 ZD |
341 | 5- Initial values of variables that are not GIMPLE registers are |
342 | considered VARYING. */ | |
6de9cd9a | 343 | |
0bca51f0 DN |
344 | static prop_value_t |
345 | get_default_value (tree var) | |
346 | { | |
347 | tree sym = SSA_NAME_VAR (var); | |
348 | prop_value_t val = { UNINITIALIZED, NULL_TREE, NULL_TREE }; | |
fc9962ee | 349 | tree cst_val; |
106dec71 | 350 | |
0bca51f0 | 351 | if (!do_store_ccp && !is_gimple_reg (var)) |
6de9cd9a | 352 | { |
0bca51f0 DN |
353 | /* Short circuit for regular CCP. We are not interested in any |
354 | non-register when DO_STORE_CCP is false. */ | |
750628d8 | 355 | val.lattice_val = VARYING; |
6de9cd9a | 356 | } |
0bca51f0 DN |
357 | else if (SSA_NAME_VALUE (var) |
358 | && is_gimple_min_invariant (SSA_NAME_VALUE (var))) | |
750628d8 | 359 | { |
0bca51f0 DN |
360 | val.lattice_val = CONSTANT; |
361 | val.value = SSA_NAME_VALUE (var); | |
750628d8 | 362 | } |
fc9962ee | 363 | else if ((cst_val = get_symbol_constant_value (sym)) != NULL_TREE) |
750628d8 | 364 | { |
0bca51f0 DN |
365 | /* Globals and static variables declared 'const' take their |
366 | initial value. */ | |
367 | val.lattice_val = CONSTANT; | |
fc9962ee | 368 | val.value = cst_val; |
0bca51f0 | 369 | val.mem_ref = sym; |
750628d8 DN |
370 | } |
371 | else | |
372 | { | |
750628d8 | 373 | tree stmt = SSA_NAME_DEF_STMT (var); |
6de9cd9a | 374 | |
0bca51f0 DN |
375 | if (IS_EMPTY_STMT (stmt)) |
376 | { | |
377 | /* Variables defined by an empty statement are those used | |
378 | before being initialized. If VAR is a local variable, we | |
106dec71 ZD |
379 | can assume initially that it is UNDEFINED, otherwise we must |
380 | consider it VARYING. */ | |
0bca51f0 DN |
381 | if (is_gimple_reg (sym) && TREE_CODE (sym) != PARM_DECL) |
382 | val.lattice_val = UNDEFINED; | |
0bca51f0 | 383 | else |
750628d8 DN |
384 | val.lattice_val = VARYING; |
385 | } | |
07beea0d | 386 | else if (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT |
0bca51f0 DN |
387 | || TREE_CODE (stmt) == PHI_NODE) |
388 | { | |
389 | /* Any other variable defined by an assignment or a PHI node | |
106dec71 ZD |
390 | is considered UNDEFINED. */ |
391 | val.lattice_val = UNDEFINED; | |
0bca51f0 DN |
392 | } |
393 | else | |
394 | { | |
395 | /* Otherwise, VAR will never take on a constant value. */ | |
396 | val.lattice_val = VARYING; | |
397 | } | |
750628d8 | 398 | } |
6de9cd9a | 399 | |
750628d8 DN |
400 | return val; |
401 | } | |
6de9cd9a | 402 | |
6de9cd9a | 403 | |
106dec71 | 404 | /* Get the constant value associated with variable VAR. */ |
6de9cd9a | 405 | |
106dec71 ZD |
406 | static inline prop_value_t * |
407 | get_value (tree var) | |
0bca51f0 DN |
408 | { |
409 | prop_value_t *val = &const_val[SSA_NAME_VERSION (var)]; | |
106dec71 ZD |
410 | |
411 | if (val->lattice_val == UNINITIALIZED) | |
6de9cd9a DN |
412 | *val = get_default_value (var); |
413 | ||
414 | return val; | |
415 | } | |
416 | ||
106dec71 ZD |
417 | /* Sets the value associated with VAR to VARYING. */ |
418 | ||
419 | static inline void | |
420 | set_value_varying (tree var) | |
421 | { | |
422 | prop_value_t *val = &const_val[SSA_NAME_VERSION (var)]; | |
423 | ||
424 | val->lattice_val = VARYING; | |
425 | val->value = NULL_TREE; | |
426 | val->mem_ref = NULL_TREE; | |
427 | } | |
6de9cd9a | 428 | |
fbb5445b L |
429 | /* For float types, modify the value of VAL to make ccp work correctly |
430 | for non-standard values (-0, NaN): | |
431 | ||
432 | If HONOR_SIGNED_ZEROS is false, and VAL = -0, we canonicalize it to 0. | |
433 | If HONOR_NANS is false, and VAL is NaN, we canonicalize it to UNDEFINED. | |
434 | This is to fix the following problem (see PR 29921): Suppose we have | |
435 | ||
436 | x = 0.0 * y | |
437 | ||
438 | and we set value of y to NaN. This causes value of x to be set to NaN. | |
439 | When we later determine that y is in fact VARYING, fold uses the fact | |
440 | that HONOR_NANS is false, and we try to change the value of x to 0, | |
441 | causing an ICE. With HONOR_NANS being false, the real appearance of | |
442 | NaN would cause undefined behavior, though, so claiming that y (and x) | |
443 | are UNDEFINED initially is correct. */ | |
444 | ||
445 | static void | |
446 | canonicalize_float_value (prop_value_t *val) | |
447 | { | |
448 | enum machine_mode mode; | |
449 | tree type; | |
450 | REAL_VALUE_TYPE d; | |
451 | ||
452 | if (val->lattice_val != CONSTANT | |
453 | || TREE_CODE (val->value) != REAL_CST) | |
454 | return; | |
455 | ||
456 | d = TREE_REAL_CST (val->value); | |
457 | type = TREE_TYPE (val->value); | |
458 | mode = TYPE_MODE (type); | |
459 | ||
460 | if (!HONOR_SIGNED_ZEROS (mode) | |
461 | && REAL_VALUE_MINUS_ZERO (d)) | |
462 | { | |
463 | val->value = build_real (type, dconst0); | |
464 | return; | |
465 | } | |
466 | ||
467 | if (!HONOR_NANS (mode) | |
468 | && REAL_VALUE_ISNAN (d)) | |
469 | { | |
470 | val->lattice_val = UNDEFINED; | |
471 | val->value = NULL; | |
472 | val->mem_ref = NULL; | |
473 | return; | |
474 | } | |
475 | } | |
476 | ||
0bca51f0 DN |
477 | /* Set the value for variable VAR to NEW_VAL. Return true if the new |
478 | value is different from VAR's previous value. */ | |
6de9cd9a | 479 | |
750628d8 | 480 | static bool |
0bca51f0 | 481 | set_lattice_value (tree var, prop_value_t new_val) |
6de9cd9a | 482 | { |
106dec71 | 483 | prop_value_t *old_val = get_value (var); |
0bca51f0 | 484 | |
fbb5445b L |
485 | canonicalize_float_value (&new_val); |
486 | ||
0bca51f0 | 487 | /* Lattice transitions must always be monotonically increasing in |
106dec71 ZD |
488 | value. If *OLD_VAL and NEW_VAL are the same, return false to |
489 | inform the caller that this was a non-transition. */ | |
490 | ||
fc9962ee | 491 | gcc_assert (old_val->lattice_val < new_val.lattice_val |
0bca51f0 | 492 | || (old_val->lattice_val == new_val.lattice_val |
fc9962ee ZD |
493 | && ((!old_val->value && !new_val.value) |
494 | || operand_equal_p (old_val->value, new_val.value, 0)) | |
106dec71 | 495 | && old_val->mem_ref == new_val.mem_ref)); |
0bca51f0 DN |
496 | |
497 | if (old_val->lattice_val != new_val.lattice_val) | |
6de9cd9a | 498 | { |
750628d8 DN |
499 | if (dump_file && (dump_flags & TDF_DETAILS)) |
500 | { | |
0bca51f0 | 501 | dump_lattice_value (dump_file, "Lattice value changed to ", new_val); |
106dec71 | 502 | fprintf (dump_file, ". Adding SSA edges to worklist.\n"); |
750628d8 DN |
503 | } |
504 | ||
0bca51f0 DN |
505 | *old_val = new_val; |
506 | ||
106dec71 ZD |
507 | gcc_assert (new_val.lattice_val != UNDEFINED); |
508 | return true; | |
6de9cd9a | 509 | } |
750628d8 DN |
510 | |
511 | return false; | |
6de9cd9a DN |
512 | } |
513 | ||
514 | ||
0bca51f0 | 515 | /* Return the likely CCP lattice value for STMT. |
6de9cd9a | 516 | |
750628d8 | 517 | If STMT has no operands, then return CONSTANT. |
6de9cd9a | 518 | |
7f879c96 RG |
519 | Else if undefinedness of operands of STMT cause its value to be |
520 | undefined, then return UNDEFINED. | |
6de9cd9a | 521 | |
750628d8 | 522 | Else if any operands of STMT are constants, then return CONSTANT. |
6de9cd9a | 523 | |
750628d8 | 524 | Else return VARYING. */ |
6de9cd9a | 525 | |
0bca51f0 | 526 | static ccp_lattice_t |
750628d8 DN |
527 | likely_value (tree stmt) |
528 | { | |
7f879c96 | 529 | bool has_constant_operand, has_undefined_operand, all_undefined_operands; |
750628d8 DN |
530 | stmt_ann_t ann; |
531 | tree use; | |
532 | ssa_op_iter iter; | |
6de9cd9a | 533 | |
750628d8 | 534 | ann = stmt_ann (stmt); |
0bca51f0 DN |
535 | |
536 | /* If the statement has volatile operands, it won't fold to a | |
537 | constant value. */ | |
538 | if (ann->has_volatile_ops) | |
539 | return VARYING; | |
540 | ||
541 | /* If we are not doing store-ccp, statements with loads | |
542 | and/or stores will never fold into a constant. */ | |
543 | if (!do_store_ccp | |
ff88c5aa | 544 | && !ZERO_SSA_OPERANDS (stmt, SSA_OP_ALL_VIRTUALS)) |
750628d8 | 545 | return VARYING; |
6de9cd9a | 546 | |
0bca51f0 DN |
547 | |
548 | /* A CALL_EXPR is assumed to be varying. NOTE: This may be overly | |
549 | conservative, in the presence of const and pure calls. */ | |
750628d8 DN |
550 | if (get_call_expr_in (stmt) != NULL_TREE) |
551 | return VARYING; | |
6de9cd9a | 552 | |
0bca51f0 DN |
553 | /* Anything other than assignments and conditional jumps are not |
554 | interesting for CCP. */ | |
07beea0d | 555 | if (TREE_CODE (stmt) != GIMPLE_MODIFY_STMT |
106dec71 | 556 | && !(TREE_CODE (stmt) == RETURN_EXPR && get_rhs (stmt) != NULL_TREE) |
0bca51f0 DN |
557 | && TREE_CODE (stmt) != COND_EXPR |
558 | && TREE_CODE (stmt) != SWITCH_EXPR) | |
559 | return VARYING; | |
560 | ||
a318e3ac SB |
561 | if (is_gimple_min_invariant (get_rhs (stmt))) |
562 | return CONSTANT; | |
563 | ||
106dec71 | 564 | has_constant_operand = false; |
7f879c96 RG |
565 | has_undefined_operand = false; |
566 | all_undefined_operands = true; | |
106dec71 | 567 | FOR_EACH_SSA_TREE_OPERAND (use, stmt, iter, SSA_OP_USE | SSA_OP_VUSE) |
750628d8 | 568 | { |
106dec71 | 569 | prop_value_t *val = get_value (use); |
750628d8 | 570 | |
106dec71 | 571 | if (val->lattice_val == UNDEFINED) |
7f879c96 RG |
572 | has_undefined_operand = true; |
573 | else | |
574 | all_undefined_operands = false; | |
0bca51f0 | 575 | |
750628d8 | 576 | if (val->lattice_val == CONSTANT) |
106dec71 | 577 | has_constant_operand = true; |
6de9cd9a | 578 | } |
750628d8 | 579 | |
7f879c96 RG |
580 | /* If the operation combines operands like COMPLEX_EXPR make sure to |
581 | not mark the result UNDEFINED if only one part of the result is | |
582 | undefined. */ | |
583 | if (has_undefined_operand | |
584 | && all_undefined_operands) | |
585 | return UNDEFINED; | |
586 | else if (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT | |
587 | && has_undefined_operand) | |
588 | { | |
589 | switch (TREE_CODE (GIMPLE_STMT_OPERAND (stmt, 1))) | |
590 | { | |
591 | /* Unary operators are handled with all_undefined_operands. */ | |
592 | case PLUS_EXPR: | |
593 | case MINUS_EXPR: | |
7f879c96 | 594 | case POINTER_PLUS_EXPR: |
7f879c96 RG |
595 | /* Not MIN_EXPR, MAX_EXPR. One VARYING operand may be selected. |
596 | Not bitwise operators, one VARYING operand may specify the | |
597 | result completely. Not logical operators for the same reason. | |
0cedb9e9 RG |
598 | Not COMPLEX_EXPR as one VARYING operand makes the result partly |
599 | not UNDEFINED. Not *DIV_EXPR, comparisons and shifts because | |
600 | the undefined operand may be promoted. */ | |
7f879c96 RG |
601 | return UNDEFINED; |
602 | ||
603 | default: | |
604 | ; | |
605 | } | |
606 | } | |
607 | /* If there was an UNDEFINED operand but the result may be not UNDEFINED | |
608 | fall back to VARYING even if there were CONSTANT operands. */ | |
609 | if (has_undefined_operand) | |
610 | return VARYING; | |
611 | ||
106dec71 ZD |
612 | if (has_constant_operand |
613 | /* We do not consider virtual operands here -- load from read-only | |
614 | memory may have only VARYING virtual operands, but still be | |
615 | constant. */ | |
616 | || ZERO_SSA_OPERANDS (stmt, SSA_OP_USE)) | |
0bca51f0 DN |
617 | return CONSTANT; |
618 | ||
106dec71 | 619 | return VARYING; |
6de9cd9a DN |
620 | } |
621 | ||
106dec71 ZD |
622 | /* Returns true if STMT cannot be constant. */ |
623 | ||
624 | static bool | |
625 | surely_varying_stmt_p (tree stmt) | |
626 | { | |
627 | /* If the statement has operands that we cannot handle, it cannot be | |
628 | constant. */ | |
629 | if (stmt_ann (stmt)->has_volatile_ops) | |
630 | return true; | |
631 | ||
632 | if (!ZERO_SSA_OPERANDS (stmt, SSA_OP_ALL_VIRTUALS)) | |
633 | { | |
634 | if (!do_store_ccp) | |
635 | return true; | |
636 | ||
637 | /* We can only handle simple loads and stores. */ | |
638 | if (!stmt_makes_single_load (stmt) | |
639 | && !stmt_makes_single_store (stmt)) | |
640 | return true; | |
641 | } | |
642 | ||
643 | /* If it contains a call, it is varying. */ | |
644 | if (get_call_expr_in (stmt) != NULL_TREE) | |
645 | return true; | |
646 | ||
647 | /* Anything other than assignments and conditional jumps are not | |
648 | interesting for CCP. */ | |
07beea0d | 649 | if (TREE_CODE (stmt) != GIMPLE_MODIFY_STMT |
106dec71 ZD |
650 | && !(TREE_CODE (stmt) == RETURN_EXPR && get_rhs (stmt) != NULL_TREE) |
651 | && TREE_CODE (stmt) != COND_EXPR | |
652 | && TREE_CODE (stmt) != SWITCH_EXPR) | |
653 | return true; | |
654 | ||
655 | return false; | |
656 | } | |
6de9cd9a | 657 | |
750628d8 | 658 | /* Initialize local data structures for CCP. */ |
6de9cd9a DN |
659 | |
660 | static void | |
750628d8 | 661 | ccp_initialize (void) |
6de9cd9a | 662 | { |
750628d8 | 663 | basic_block bb; |
6de9cd9a | 664 | |
b9eae1a9 | 665 | const_val = XCNEWVEC (prop_value_t, num_ssa_names); |
6de9cd9a | 666 | |
750628d8 DN |
667 | /* Initialize simulation flags for PHI nodes and statements. */ |
668 | FOR_EACH_BB (bb) | |
6de9cd9a | 669 | { |
750628d8 | 670 | block_stmt_iterator i; |
6de9cd9a | 671 | |
750628d8 DN |
672 | for (i = bsi_start (bb); !bsi_end_p (i); bsi_next (&i)) |
673 | { | |
750628d8 | 674 | tree stmt = bsi_stmt (i); |
106dec71 | 675 | bool is_varying = surely_varying_stmt_p (stmt); |
6de9cd9a | 676 | |
106dec71 | 677 | if (is_varying) |
750628d8 | 678 | { |
0bca51f0 DN |
679 | tree def; |
680 | ssa_op_iter iter; | |
681 | ||
682 | /* If the statement will not produce a constant, mark | |
683 | all its outputs VARYING. */ | |
684 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS) | |
106dec71 ZD |
685 | { |
686 | if (is_varying) | |
687 | set_value_varying (def); | |
688 | } | |
750628d8 DN |
689 | } |
690 | ||
750628d8 DN |
691 | DONT_SIMULATE_AGAIN (stmt) = is_varying; |
692 | } | |
6de9cd9a DN |
693 | } |
694 | ||
106dec71 ZD |
695 | /* Now process PHI nodes. We never set DONT_SIMULATE_AGAIN on phi node, |
696 | since we do not know which edges are executable yet, except for | |
697 | phi nodes for virtual operands when we do not do store ccp. */ | |
750628d8 | 698 | FOR_EACH_BB (bb) |
6de9cd9a | 699 | { |
0bca51f0 | 700 | tree phi; |
750628d8 DN |
701 | |
702 | for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi)) | |
703 | { | |
106dec71 ZD |
704 | if (!do_store_ccp && !is_gimple_reg (PHI_RESULT (phi))) |
705 | DONT_SIMULATE_AGAIN (phi) = true; | |
706 | else | |
707 | DONT_SIMULATE_AGAIN (phi) = false; | |
750628d8 | 708 | } |
6de9cd9a | 709 | } |
750628d8 | 710 | } |
6de9cd9a | 711 | |
6de9cd9a | 712 | |
0bca51f0 | 713 | /* Do final substitution of propagated values, cleanup the flowgraph and |
3253eafb | 714 | free allocated storage. |
6de9cd9a | 715 | |
3253eafb JH |
716 | Return TRUE when something was optimized. */ |
717 | ||
718 | static bool | |
0bca51f0 | 719 | ccp_finalize (void) |
6de9cd9a | 720 | { |
0bca51f0 | 721 | /* Perform substitutions based on the known constant values. */ |
3253eafb | 722 | bool something_changed = substitute_and_fold (const_val, false); |
6de9cd9a | 723 | |
0bca51f0 | 724 | free (const_val); |
3253eafb | 725 | return something_changed;; |
6de9cd9a DN |
726 | } |
727 | ||
728 | ||
0bca51f0 DN |
729 | /* Compute the meet operator between *VAL1 and *VAL2. Store the result |
730 | in VAL1. | |
731 | ||
732 | any M UNDEFINED = any | |
0bca51f0 DN |
733 | any M VARYING = VARYING |
734 | Ci M Cj = Ci if (i == j) | |
735 | Ci M Cj = VARYING if (i != j) | |
106dec71 | 736 | */ |
6de9cd9a DN |
737 | |
738 | static void | |
0bca51f0 | 739 | ccp_lattice_meet (prop_value_t *val1, prop_value_t *val2) |
6de9cd9a | 740 | { |
0bca51f0 | 741 | if (val1->lattice_val == UNDEFINED) |
6de9cd9a | 742 | { |
0bca51f0 DN |
743 | /* UNDEFINED M any = any */ |
744 | *val1 = *val2; | |
750628d8 | 745 | } |
0bca51f0 | 746 | else if (val2->lattice_val == UNDEFINED) |
195da47b | 747 | { |
0bca51f0 DN |
748 | /* any M UNDEFINED = any |
749 | Nothing to do. VAL1 already contains the value we want. */ | |
750 | ; | |
195da47b | 751 | } |
0bca51f0 DN |
752 | else if (val1->lattice_val == VARYING |
753 | || val2->lattice_val == VARYING) | |
750628d8 | 754 | { |
0bca51f0 DN |
755 | /* any M VARYING = VARYING. */ |
756 | val1->lattice_val = VARYING; | |
757 | val1->value = NULL_TREE; | |
758 | val1->mem_ref = NULL_TREE; | |
750628d8 | 759 | } |
0bca51f0 DN |
760 | else if (val1->lattice_val == CONSTANT |
761 | && val2->lattice_val == CONSTANT | |
762 | && simple_cst_equal (val1->value, val2->value) == 1 | |
763 | && (!do_store_ccp | |
a318e3ac SB |
764 | || (val1->mem_ref && val2->mem_ref |
765 | && operand_equal_p (val1->mem_ref, val2->mem_ref, 0)))) | |
750628d8 | 766 | { |
0bca51f0 DN |
767 | /* Ci M Cj = Ci if (i == j) |
768 | Ci M Cj = VARYING if (i != j) | |
769 | ||
770 | If these two values come from memory stores, make sure that | |
771 | they come from the same memory reference. */ | |
772 | val1->lattice_val = CONSTANT; | |
773 | val1->value = val1->value; | |
774 | val1->mem_ref = val1->mem_ref; | |
750628d8 DN |
775 | } |
776 | else | |
777 | { | |
0bca51f0 DN |
778 | /* Any other combination is VARYING. */ |
779 | val1->lattice_val = VARYING; | |
780 | val1->value = NULL_TREE; | |
781 | val1->mem_ref = NULL_TREE; | |
750628d8 | 782 | } |
6de9cd9a DN |
783 | } |
784 | ||
785 | ||
750628d8 DN |
786 | /* Loop through the PHI_NODE's parameters for BLOCK and compare their |
787 | lattice values to determine PHI_NODE's lattice value. The value of a | |
0bca51f0 | 788 | PHI node is determined calling ccp_lattice_meet with all the arguments |
750628d8 | 789 | of the PHI node that are incoming via executable edges. */ |
6de9cd9a | 790 | |
750628d8 DN |
791 | static enum ssa_prop_result |
792 | ccp_visit_phi_node (tree phi) | |
6de9cd9a | 793 | { |
750628d8 | 794 | int i; |
0bca51f0 | 795 | prop_value_t *old_val, new_val; |
6de9cd9a | 796 | |
750628d8 | 797 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6de9cd9a | 798 | { |
750628d8 DN |
799 | fprintf (dump_file, "\nVisiting PHI node: "); |
800 | print_generic_expr (dump_file, phi, dump_flags); | |
6de9cd9a | 801 | } |
6de9cd9a | 802 | |
106dec71 | 803 | old_val = get_value (PHI_RESULT (phi)); |
750628d8 DN |
804 | switch (old_val->lattice_val) |
805 | { | |
806 | case VARYING: | |
0bca51f0 | 807 | return SSA_PROP_VARYING; |
6de9cd9a | 808 | |
750628d8 DN |
809 | case CONSTANT: |
810 | new_val = *old_val; | |
811 | break; | |
6de9cd9a | 812 | |
750628d8 | 813 | case UNDEFINED: |
750628d8 | 814 | new_val.lattice_val = UNDEFINED; |
0bca51f0 DN |
815 | new_val.value = NULL_TREE; |
816 | new_val.mem_ref = NULL_TREE; | |
750628d8 | 817 | break; |
6de9cd9a | 818 | |
750628d8 | 819 | default: |
1e128c5f | 820 | gcc_unreachable (); |
750628d8 | 821 | } |
6de9cd9a | 822 | |
750628d8 DN |
823 | for (i = 0; i < PHI_NUM_ARGS (phi); i++) |
824 | { | |
0bca51f0 DN |
825 | /* Compute the meet operator over all the PHI arguments flowing |
826 | through executable edges. */ | |
750628d8 | 827 | edge e = PHI_ARG_EDGE (phi, i); |
6de9cd9a | 828 | |
750628d8 DN |
829 | if (dump_file && (dump_flags & TDF_DETAILS)) |
830 | { | |
831 | fprintf (dump_file, | |
832 | "\n Argument #%d (%d -> %d %sexecutable)\n", | |
833 | i, e->src->index, e->dest->index, | |
834 | (e->flags & EDGE_EXECUTABLE) ? "" : "not "); | |
835 | } | |
836 | ||
837 | /* If the incoming edge is executable, Compute the meet operator for | |
838 | the existing value of the PHI node and the current PHI argument. */ | |
839 | if (e->flags & EDGE_EXECUTABLE) | |
840 | { | |
0bca51f0 DN |
841 | tree arg = PHI_ARG_DEF (phi, i); |
842 | prop_value_t arg_val; | |
6de9cd9a | 843 | |
0bca51f0 | 844 | if (is_gimple_min_invariant (arg)) |
750628d8 | 845 | { |
0bca51f0 DN |
846 | arg_val.lattice_val = CONSTANT; |
847 | arg_val.value = arg; | |
848 | arg_val.mem_ref = NULL_TREE; | |
750628d8 DN |
849 | } |
850 | else | |
106dec71 | 851 | arg_val = *(get_value (arg)); |
6de9cd9a | 852 | |
0bca51f0 | 853 | ccp_lattice_meet (&new_val, &arg_val); |
6de9cd9a | 854 | |
750628d8 DN |
855 | if (dump_file && (dump_flags & TDF_DETAILS)) |
856 | { | |
857 | fprintf (dump_file, "\t"); | |
0bca51f0 DN |
858 | print_generic_expr (dump_file, arg, dump_flags); |
859 | dump_lattice_value (dump_file, "\tValue: ", arg_val); | |
750628d8 DN |
860 | fprintf (dump_file, "\n"); |
861 | } | |
6de9cd9a | 862 | |
750628d8 DN |
863 | if (new_val.lattice_val == VARYING) |
864 | break; | |
865 | } | |
866 | } | |
6de9cd9a DN |
867 | |
868 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
750628d8 DN |
869 | { |
870 | dump_lattice_value (dump_file, "\n PHI node value: ", new_val); | |
871 | fprintf (dump_file, "\n\n"); | |
872 | } | |
873 | ||
106dec71 | 874 | /* Make the transition to the new value. */ |
750628d8 DN |
875 | if (set_lattice_value (PHI_RESULT (phi), new_val)) |
876 | { | |
877 | if (new_val.lattice_val == VARYING) | |
878 | return SSA_PROP_VARYING; | |
879 | else | |
880 | return SSA_PROP_INTERESTING; | |
881 | } | |
882 | else | |
883 | return SSA_PROP_NOT_INTERESTING; | |
6de9cd9a DN |
884 | } |
885 | ||
886 | ||
750628d8 DN |
887 | /* CCP specific front-end to the non-destructive constant folding |
888 | routines. | |
6de9cd9a DN |
889 | |
890 | Attempt to simplify the RHS of STMT knowing that one or more | |
891 | operands are constants. | |
892 | ||
893 | If simplification is possible, return the simplified RHS, | |
894 | otherwise return the original RHS. */ | |
895 | ||
896 | static tree | |
897 | ccp_fold (tree stmt) | |
898 | { | |
899 | tree rhs = get_rhs (stmt); | |
900 | enum tree_code code = TREE_CODE (rhs); | |
6615c446 | 901 | enum tree_code_class kind = TREE_CODE_CLASS (code); |
6de9cd9a DN |
902 | tree retval = NULL_TREE; |
903 | ||
6de9cd9a | 904 | if (TREE_CODE (rhs) == SSA_NAME) |
0bca51f0 DN |
905 | { |
906 | /* If the RHS is an SSA_NAME, return its known constant value, | |
907 | if any. */ | |
106dec71 | 908 | return get_value (rhs)->value; |
0bca51f0 DN |
909 | } |
910 | else if (do_store_ccp && stmt_makes_single_load (stmt)) | |
911 | { | |
912 | /* If the RHS is a memory load, see if the VUSEs associated with | |
913 | it are a valid constant for that memory load. */ | |
914 | prop_value_t *val = get_value_loaded_by (stmt, const_val); | |
add9e6d3 AP |
915 | if (val && val->mem_ref) |
916 | { | |
917 | if (operand_equal_p (val->mem_ref, rhs, 0)) | |
918 | return val->value; | |
919 | ||
920 | /* If RHS is extracting REALPART_EXPR or IMAGPART_EXPR of a | |
921 | complex type with a known constant value, return it. */ | |
922 | if ((TREE_CODE (rhs) == REALPART_EXPR | |
923 | || TREE_CODE (rhs) == IMAGPART_EXPR) | |
924 | && operand_equal_p (val->mem_ref, TREE_OPERAND (rhs, 0), 0)) | |
925 | return fold_build1 (TREE_CODE (rhs), TREE_TYPE (rhs), val->value); | |
926 | } | |
927 | return NULL_TREE; | |
0bca51f0 | 928 | } |
6de9cd9a DN |
929 | |
930 | /* Unary operators. Note that we know the single operand must | |
931 | be a constant. So this should almost always return a | |
932 | simplified RHS. */ | |
6615c446 | 933 | if (kind == tcc_unary) |
6de9cd9a DN |
934 | { |
935 | /* Handle unary operators which can appear in GIMPLE form. */ | |
936 | tree op0 = TREE_OPERAND (rhs, 0); | |
937 | ||
938 | /* Simplify the operand down to a constant. */ | |
939 | if (TREE_CODE (op0) == SSA_NAME) | |
940 | { | |
106dec71 | 941 | prop_value_t *val = get_value (op0); |
6de9cd9a | 942 | if (val->lattice_val == CONSTANT) |
106dec71 | 943 | op0 = get_value (op0)->value; |
6de9cd9a DN |
944 | } |
945 | ||
078152a2 | 946 | if ((code == NOP_EXPR || code == CONVERT_EXPR) |
36618b93 | 947 | && useless_type_conversion_p (TREE_TYPE (rhs), TREE_TYPE (op0))) |
078152a2 | 948 | return op0; |
615bc06a | 949 | return fold_unary (code, TREE_TYPE (rhs), op0); |
6de9cd9a DN |
950 | } |
951 | ||
952 | /* Binary and comparison operators. We know one or both of the | |
953 | operands are constants. */ | |
6615c446 JO |
954 | else if (kind == tcc_binary |
955 | || kind == tcc_comparison | |
6de9cd9a DN |
956 | || code == TRUTH_AND_EXPR |
957 | || code == TRUTH_OR_EXPR | |
958 | || code == TRUTH_XOR_EXPR) | |
959 | { | |
960 | /* Handle binary and comparison operators that can appear in | |
961 | GIMPLE form. */ | |
962 | tree op0 = TREE_OPERAND (rhs, 0); | |
963 | tree op1 = TREE_OPERAND (rhs, 1); | |
964 | ||
965 | /* Simplify the operands down to constants when appropriate. */ | |
966 | if (TREE_CODE (op0) == SSA_NAME) | |
967 | { | |
106dec71 | 968 | prop_value_t *val = get_value (op0); |
6de9cd9a | 969 | if (val->lattice_val == CONSTANT) |
0bca51f0 | 970 | op0 = val->value; |
6de9cd9a DN |
971 | } |
972 | ||
973 | if (TREE_CODE (op1) == SSA_NAME) | |
974 | { | |
106dec71 | 975 | prop_value_t *val = get_value (op1); |
6de9cd9a | 976 | if (val->lattice_val == CONSTANT) |
0bca51f0 | 977 | op1 = val->value; |
6de9cd9a DN |
978 | } |
979 | ||
615bc06a | 980 | return fold_binary (code, TREE_TYPE (rhs), op0, op1); |
6de9cd9a DN |
981 | } |
982 | ||
983 | /* We may be able to fold away calls to builtin functions if their | |
9cf737f8 | 984 | arguments are constants. */ |
6de9cd9a | 985 | else if (code == CALL_EXPR |
5039610b SL |
986 | && TREE_CODE (CALL_EXPR_FN (rhs)) == ADDR_EXPR |
987 | && TREE_CODE (TREE_OPERAND (CALL_EXPR_FN (rhs), 0)) == FUNCTION_DECL | |
988 | && DECL_BUILT_IN (TREE_OPERAND (CALL_EXPR_FN (rhs), 0))) | |
6de9cd9a | 989 | { |
f47c96aa | 990 | if (!ZERO_SSA_OPERANDS (stmt, SSA_OP_USE)) |
6de9cd9a | 991 | { |
f47c96aa | 992 | tree *orig, var; |
f47c96aa AM |
993 | size_t i = 0; |
994 | ssa_op_iter iter; | |
995 | use_operand_p var_p; | |
6de9cd9a DN |
996 | |
997 | /* Preserve the original values of every operand. */ | |
858904db | 998 | orig = XNEWVEC (tree, NUM_SSA_OPERANDS (stmt, SSA_OP_USE)); |
f47c96aa AM |
999 | FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_USE) |
1000 | orig[i++] = var; | |
6de9cd9a DN |
1001 | |
1002 | /* Substitute operands with their values and try to fold. */ | |
0bca51f0 | 1003 | replace_uses_in (stmt, NULL, const_val); |
5039610b | 1004 | retval = fold_call_expr (rhs, false); |
6de9cd9a DN |
1005 | |
1006 | /* Restore operands to their original form. */ | |
f47c96aa AM |
1007 | i = 0; |
1008 | FOR_EACH_SSA_USE_OPERAND (var_p, stmt, iter, SSA_OP_USE) | |
1009 | SET_USE (var_p, orig[i++]); | |
6de9cd9a DN |
1010 | free (orig); |
1011 | } | |
1012 | } | |
1013 | else | |
1014 | return rhs; | |
1015 | ||
1016 | /* If we got a simplified form, see if we need to convert its type. */ | |
1017 | if (retval) | |
a32e70c3 | 1018 | return fold_convert (TREE_TYPE (rhs), retval); |
6de9cd9a DN |
1019 | |
1020 | /* No simplification was possible. */ | |
1021 | return rhs; | |
1022 | } | |
1023 | ||
1024 | ||
ae3df618 SB |
1025 | /* Return the tree representing the element referenced by T if T is an |
1026 | ARRAY_REF or COMPONENT_REF into constant aggregates. Return | |
1027 | NULL_TREE otherwise. */ | |
1028 | ||
1029 | static tree | |
1030 | fold_const_aggregate_ref (tree t) | |
1031 | { | |
1032 | prop_value_t *value; | |
4038c495 GB |
1033 | tree base, ctor, idx, field; |
1034 | unsigned HOST_WIDE_INT cnt; | |
1035 | tree cfield, cval; | |
ae3df618 SB |
1036 | |
1037 | switch (TREE_CODE (t)) | |
1038 | { | |
1039 | case ARRAY_REF: | |
1040 | /* Get a CONSTRUCTOR. If BASE is a VAR_DECL, get its | |
1041 | DECL_INITIAL. If BASE is a nested reference into another | |
1042 | ARRAY_REF or COMPONENT_REF, make a recursive call to resolve | |
1043 | the inner reference. */ | |
1044 | base = TREE_OPERAND (t, 0); | |
1045 | switch (TREE_CODE (base)) | |
1046 | { | |
1047 | case VAR_DECL: | |
1048 | if (!TREE_READONLY (base) | |
1049 | || TREE_CODE (TREE_TYPE (base)) != ARRAY_TYPE | |
1050 | || !targetm.binds_local_p (base)) | |
1051 | return NULL_TREE; | |
1052 | ||
1053 | ctor = DECL_INITIAL (base); | |
1054 | break; | |
1055 | ||
1056 | case ARRAY_REF: | |
1057 | case COMPONENT_REF: | |
1058 | ctor = fold_const_aggregate_ref (base); | |
1059 | break; | |
1060 | ||
1061 | default: | |
1062 | return NULL_TREE; | |
1063 | } | |
1064 | ||
1065 | if (ctor == NULL_TREE | |
faaf1436 RG |
1066 | || (TREE_CODE (ctor) != CONSTRUCTOR |
1067 | && TREE_CODE (ctor) != STRING_CST) | |
ae3df618 SB |
1068 | || !TREE_STATIC (ctor)) |
1069 | return NULL_TREE; | |
1070 | ||
1071 | /* Get the index. If we have an SSA_NAME, try to resolve it | |
1072 | with the current lattice value for the SSA_NAME. */ | |
1073 | idx = TREE_OPERAND (t, 1); | |
1074 | switch (TREE_CODE (idx)) | |
1075 | { | |
1076 | case SSA_NAME: | |
106dec71 | 1077 | if ((value = get_value (idx)) |
ae3df618 SB |
1078 | && value->lattice_val == CONSTANT |
1079 | && TREE_CODE (value->value) == INTEGER_CST) | |
1080 | idx = value->value; | |
1081 | else | |
1082 | return NULL_TREE; | |
1083 | break; | |
1084 | ||
1085 | case INTEGER_CST: | |
1086 | break; | |
1087 | ||
1088 | default: | |
1089 | return NULL_TREE; | |
1090 | } | |
1091 | ||
faaf1436 RG |
1092 | /* Fold read from constant string. */ |
1093 | if (TREE_CODE (ctor) == STRING_CST) | |
1094 | { | |
1095 | if ((TYPE_MODE (TREE_TYPE (t)) | |
1096 | == TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) | |
1097 | && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) | |
1098 | == MODE_INT) | |
1099 | && GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) == 1 | |
1100 | && compare_tree_int (idx, TREE_STRING_LENGTH (ctor)) < 0) | |
0c4d4efb DJ |
1101 | return build_int_cst_type (TREE_TYPE (t), |
1102 | (TREE_STRING_POINTER (ctor) | |
1103 | [TREE_INT_CST_LOW (idx)])); | |
faaf1436 RG |
1104 | return NULL_TREE; |
1105 | } | |
1106 | ||
ae3df618 | 1107 | /* Whoo-hoo! I'll fold ya baby. Yeah! */ |
4038c495 GB |
1108 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, cval) |
1109 | if (tree_int_cst_equal (cfield, idx)) | |
1110 | return cval; | |
ae3df618 SB |
1111 | break; |
1112 | ||
1113 | case COMPONENT_REF: | |
1114 | /* Get a CONSTRUCTOR. If BASE is a VAR_DECL, get its | |
1115 | DECL_INITIAL. If BASE is a nested reference into another | |
1116 | ARRAY_REF or COMPONENT_REF, make a recursive call to resolve | |
1117 | the inner reference. */ | |
1118 | base = TREE_OPERAND (t, 0); | |
1119 | switch (TREE_CODE (base)) | |
1120 | { | |
1121 | case VAR_DECL: | |
1122 | if (!TREE_READONLY (base) | |
1123 | || TREE_CODE (TREE_TYPE (base)) != RECORD_TYPE | |
1124 | || !targetm.binds_local_p (base)) | |
1125 | return NULL_TREE; | |
1126 | ||
1127 | ctor = DECL_INITIAL (base); | |
1128 | break; | |
1129 | ||
1130 | case ARRAY_REF: | |
1131 | case COMPONENT_REF: | |
1132 | ctor = fold_const_aggregate_ref (base); | |
1133 | break; | |
1134 | ||
1135 | default: | |
1136 | return NULL_TREE; | |
1137 | } | |
1138 | ||
1139 | if (ctor == NULL_TREE | |
1140 | || TREE_CODE (ctor) != CONSTRUCTOR | |
1141 | || !TREE_STATIC (ctor)) | |
1142 | return NULL_TREE; | |
1143 | ||
1144 | field = TREE_OPERAND (t, 1); | |
1145 | ||
4038c495 GB |
1146 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, cval) |
1147 | if (cfield == field | |
ae3df618 | 1148 | /* FIXME: Handle bit-fields. */ |
4038c495 GB |
1149 | && ! DECL_BIT_FIELD (cfield)) |
1150 | return cval; | |
ae3df618 SB |
1151 | break; |
1152 | ||
1ebd8d9a SB |
1153 | case REALPART_EXPR: |
1154 | case IMAGPART_EXPR: | |
1155 | { | |
1156 | tree c = fold_const_aggregate_ref (TREE_OPERAND (t, 0)); | |
1157 | if (c && TREE_CODE (c) == COMPLEX_CST) | |
1158 | return fold_build1 (TREE_CODE (t), TREE_TYPE (t), c); | |
1159 | break; | |
1160 | } | |
1161 | ||
ae3df618 SB |
1162 | default: |
1163 | break; | |
1164 | } | |
1165 | ||
1166 | return NULL_TREE; | |
1167 | } | |
1168 | ||
6de9cd9a DN |
1169 | /* Evaluate statement STMT. */ |
1170 | ||
0bca51f0 | 1171 | static prop_value_t |
6de9cd9a DN |
1172 | evaluate_stmt (tree stmt) |
1173 | { | |
0bca51f0 | 1174 | prop_value_t val; |
faaf1436 | 1175 | tree simplified = NULL_TREE; |
0bca51f0 | 1176 | ccp_lattice_t likelyvalue = likely_value (stmt); |
6ac01510 | 1177 | bool is_constant; |
0bca51f0 DN |
1178 | |
1179 | val.mem_ref = NULL_TREE; | |
6de9cd9a | 1180 | |
6ac01510 ILT |
1181 | fold_defer_overflow_warnings (); |
1182 | ||
6de9cd9a DN |
1183 | /* If the statement is likely to have a CONSTANT result, then try |
1184 | to fold the statement to determine the constant value. */ | |
1185 | if (likelyvalue == CONSTANT) | |
1186 | simplified = ccp_fold (stmt); | |
1187 | /* If the statement is likely to have a VARYING result, then do not | |
1188 | bother folding the statement. */ | |
faaf1436 | 1189 | if (likelyvalue == VARYING) |
6de9cd9a | 1190 | simplified = get_rhs (stmt); |
ae3df618 SB |
1191 | /* If the statement is an ARRAY_REF or COMPONENT_REF into constant |
1192 | aggregates, extract the referenced constant. Otherwise the | |
1193 | statement is likely to have an UNDEFINED value, and there will be | |
1194 | nothing to do. Note that fold_const_aggregate_ref returns | |
1195 | NULL_TREE if the first case does not match. */ | |
faaf1436 | 1196 | else if (!simplified) |
ae3df618 | 1197 | simplified = fold_const_aggregate_ref (get_rhs (stmt)); |
6de9cd9a | 1198 | |
6ac01510 ILT |
1199 | is_constant = simplified && is_gimple_min_invariant (simplified); |
1200 | ||
1201 | fold_undefer_overflow_warnings (is_constant, stmt, 0); | |
1202 | ||
1203 | if (is_constant) | |
6de9cd9a DN |
1204 | { |
1205 | /* The statement produced a constant value. */ | |
1206 | val.lattice_val = CONSTANT; | |
0bca51f0 | 1207 | val.value = simplified; |
6de9cd9a DN |
1208 | } |
1209 | else | |
1210 | { | |
1211 | /* The statement produced a nonconstant value. If the statement | |
0bca51f0 DN |
1212 | had UNDEFINED operands, then the result of the statement |
1213 | should be UNDEFINED. Otherwise, the statement is VARYING. */ | |
106dec71 | 1214 | if (likelyvalue == UNDEFINED) |
a318e3ac SB |
1215 | val.lattice_val = likelyvalue; |
1216 | else | |
1217 | val.lattice_val = VARYING; | |
1218 | ||
0bca51f0 | 1219 | val.value = NULL_TREE; |
6de9cd9a | 1220 | } |
750628d8 DN |
1221 | |
1222 | return val; | |
6de9cd9a DN |
1223 | } |
1224 | ||
1225 | ||
750628d8 | 1226 | /* Visit the assignment statement STMT. Set the value of its LHS to the |
0bca51f0 DN |
1227 | value computed by the RHS and store LHS in *OUTPUT_P. If STMT |
1228 | creates virtual definitions, set the value of each new name to that | |
1229 | of the RHS (if we can derive a constant out of the RHS). */ | |
6de9cd9a | 1230 | |
750628d8 DN |
1231 | static enum ssa_prop_result |
1232 | visit_assignment (tree stmt, tree *output_p) | |
6de9cd9a | 1233 | { |
0bca51f0 | 1234 | prop_value_t val; |
750628d8 | 1235 | tree lhs, rhs; |
0bca51f0 | 1236 | enum ssa_prop_result retval; |
6de9cd9a | 1237 | |
07beea0d AH |
1238 | lhs = GIMPLE_STMT_OPERAND (stmt, 0); |
1239 | rhs = GIMPLE_STMT_OPERAND (stmt, 1); | |
6de9cd9a | 1240 | |
750628d8 DN |
1241 | if (TREE_CODE (rhs) == SSA_NAME) |
1242 | { | |
1243 | /* For a simple copy operation, we copy the lattice values. */ | |
106dec71 | 1244 | prop_value_t *nval = get_value (rhs); |
750628d8 DN |
1245 | val = *nval; |
1246 | } | |
0bca51f0 | 1247 | else if (do_store_ccp && stmt_makes_single_load (stmt)) |
750628d8 | 1248 | { |
0bca51f0 | 1249 | /* Same as above, but the RHS is not a gimple register and yet |
106dec71 | 1250 | has a known VUSE. If STMT is loading from the same memory |
0bca51f0 DN |
1251 | location that created the SSA_NAMEs for the virtual operands, |
1252 | we can propagate the value on the RHS. */ | |
1253 | prop_value_t *nval = get_value_loaded_by (stmt, const_val); | |
1254 | ||
106dec71 ZD |
1255 | if (nval |
1256 | && nval->mem_ref | |
a318e3ac | 1257 | && operand_equal_p (nval->mem_ref, rhs, 0)) |
0bca51f0 DN |
1258 | val = *nval; |
1259 | else | |
1260 | val = evaluate_stmt (stmt); | |
750628d8 DN |
1261 | } |
1262 | else | |
9390c347 | 1263 | /* Evaluate the statement. */ |
750628d8 | 1264 | val = evaluate_stmt (stmt); |
6de9cd9a | 1265 | |
9390c347 | 1266 | /* If the original LHS was a VIEW_CONVERT_EXPR, modify the constant |
ae95537a | 1267 | value to be a VIEW_CONVERT_EXPR of the old constant value. |
9390c347 RK |
1268 | |
1269 | ??? Also, if this was a definition of a bitfield, we need to widen | |
750628d8 DN |
1270 | the constant value into the type of the destination variable. This |
1271 | should not be necessary if GCC represented bitfields properly. */ | |
1272 | { | |
07beea0d | 1273 | tree orig_lhs = GIMPLE_STMT_OPERAND (stmt, 0); |
9390c347 RK |
1274 | |
1275 | if (TREE_CODE (orig_lhs) == VIEW_CONVERT_EXPR | |
1276 | && val.lattice_val == CONSTANT) | |
1277 | { | |
0dd4b47b KH |
1278 | tree w = fold_unary (VIEW_CONVERT_EXPR, |
1279 | TREE_TYPE (TREE_OPERAND (orig_lhs, 0)), | |
1280 | val.value); | |
ae95537a | 1281 | |
3d36fb45 | 1282 | orig_lhs = TREE_OPERAND (orig_lhs, 0); |
ae95537a | 1283 | if (w && is_gimple_min_invariant (w)) |
0bca51f0 | 1284 | val.value = w; |
ae95537a RK |
1285 | else |
1286 | { | |
1287 | val.lattice_val = VARYING; | |
0bca51f0 | 1288 | val.value = NULL; |
ae95537a | 1289 | } |
9390c347 RK |
1290 | } |
1291 | ||
750628d8 | 1292 | if (val.lattice_val == CONSTANT |
9390c347 RK |
1293 | && TREE_CODE (orig_lhs) == COMPONENT_REF |
1294 | && DECL_BIT_FIELD (TREE_OPERAND (orig_lhs, 1))) | |
6de9cd9a | 1295 | { |
0bca51f0 | 1296 | tree w = widen_bitfield (val.value, TREE_OPERAND (orig_lhs, 1), |
9390c347 | 1297 | orig_lhs); |
750628d8 DN |
1298 | |
1299 | if (w && is_gimple_min_invariant (w)) | |
0bca51f0 | 1300 | val.value = w; |
750628d8 | 1301 | else |
6de9cd9a | 1302 | { |
750628d8 | 1303 | val.lattice_val = VARYING; |
0bca51f0 DN |
1304 | val.value = NULL_TREE; |
1305 | val.mem_ref = NULL_TREE; | |
6de9cd9a | 1306 | } |
6de9cd9a | 1307 | } |
750628d8 | 1308 | } |
6de9cd9a | 1309 | |
0bca51f0 | 1310 | retval = SSA_PROP_NOT_INTERESTING; |
6de9cd9a | 1311 | |
750628d8 | 1312 | /* Set the lattice value of the statement's output. */ |
0bca51f0 | 1313 | if (TREE_CODE (lhs) == SSA_NAME) |
6de9cd9a | 1314 | { |
0bca51f0 DN |
1315 | /* If STMT is an assignment to an SSA_NAME, we only have one |
1316 | value to set. */ | |
1317 | if (set_lattice_value (lhs, val)) | |
1318 | { | |
1319 | *output_p = lhs; | |
1320 | if (val.lattice_val == VARYING) | |
1321 | retval = SSA_PROP_VARYING; | |
1322 | else | |
1323 | retval = SSA_PROP_INTERESTING; | |
1324 | } | |
6de9cd9a | 1325 | } |
0bca51f0 DN |
1326 | else if (do_store_ccp && stmt_makes_single_store (stmt)) |
1327 | { | |
38635499 DN |
1328 | /* Otherwise, set the names in VDEF operands to the new |
1329 | constant value and mark the LHS as the memory reference | |
1330 | associated with VAL. */ | |
0bca51f0 DN |
1331 | ssa_op_iter i; |
1332 | tree vdef; | |
1333 | bool changed; | |
1334 | ||
0bca51f0 | 1335 | /* Mark VAL as stored in the LHS of this assignment. */ |
106dec71 ZD |
1336 | if (val.lattice_val == CONSTANT) |
1337 | val.mem_ref = lhs; | |
0bca51f0 DN |
1338 | |
1339 | /* Set the value of every VDEF to VAL. */ | |
1340 | changed = false; | |
1341 | FOR_EACH_SSA_TREE_OPERAND (vdef, stmt, i, SSA_OP_VIRTUAL_DEFS) | |
fc9962ee ZD |
1342 | { |
1343 | /* See PR 29801. We may have VDEFs for read-only variables | |
1344 | (see the handling of unmodifiable variables in | |
1345 | add_virtual_operand); do not attempt to change their value. */ | |
1346 | if (get_symbol_constant_value (SSA_NAME_VAR (vdef)) != NULL_TREE) | |
1347 | continue; | |
1348 | ||
1349 | changed |= set_lattice_value (vdef, val); | |
1350 | } | |
0bca51f0 DN |
1351 | |
1352 | /* Note that for propagation purposes, we are only interested in | |
1353 | visiting statements that load the exact same memory reference | |
1354 | stored here. Those statements will have the exact same list | |
1355 | of virtual uses, so it is enough to set the output of this | |
1356 | statement to be its first virtual definition. */ | |
1357 | *output_p = first_vdef (stmt); | |
1358 | if (changed) | |
1359 | { | |
1360 | if (val.lattice_val == VARYING) | |
1361 | retval = SSA_PROP_VARYING; | |
1362 | else | |
1363 | retval = SSA_PROP_INTERESTING; | |
1364 | } | |
1365 | } | |
1366 | ||
1367 | return retval; | |
6de9cd9a DN |
1368 | } |
1369 | ||
6de9cd9a | 1370 | |
750628d8 DN |
1371 | /* Visit the conditional statement STMT. Return SSA_PROP_INTERESTING |
1372 | if it can determine which edge will be taken. Otherwise, return | |
1373 | SSA_PROP_VARYING. */ | |
1374 | ||
1375 | static enum ssa_prop_result | |
1376 | visit_cond_stmt (tree stmt, edge *taken_edge_p) | |
6de9cd9a | 1377 | { |
0bca51f0 | 1378 | prop_value_t val; |
750628d8 DN |
1379 | basic_block block; |
1380 | ||
1381 | block = bb_for_stmt (stmt); | |
1382 | val = evaluate_stmt (stmt); | |
1383 | ||
1384 | /* Find which edge out of the conditional block will be taken and add it | |
1385 | to the worklist. If no single edge can be determined statically, | |
1386 | return SSA_PROP_VARYING to feed all the outgoing edges to the | |
1387 | propagation engine. */ | |
0bca51f0 | 1388 | *taken_edge_p = val.value ? find_taken_edge (block, val.value) : 0; |
750628d8 DN |
1389 | if (*taken_edge_p) |
1390 | return SSA_PROP_INTERESTING; | |
1391 | else | |
1392 | return SSA_PROP_VARYING; | |
6de9cd9a DN |
1393 | } |
1394 | ||
6de9cd9a | 1395 | |
750628d8 DN |
1396 | /* Evaluate statement STMT. If the statement produces an output value and |
1397 | its evaluation changes the lattice value of its output, return | |
1398 | SSA_PROP_INTERESTING and set *OUTPUT_P to the SSA_NAME holding the | |
1399 | output value. | |
1400 | ||
1401 | If STMT is a conditional branch and we can determine its truth | |
1402 | value, set *TAKEN_EDGE_P accordingly. If STMT produces a varying | |
1403 | value, return SSA_PROP_VARYING. */ | |
6de9cd9a | 1404 | |
750628d8 DN |
1405 | static enum ssa_prop_result |
1406 | ccp_visit_stmt (tree stmt, edge *taken_edge_p, tree *output_p) | |
1407 | { | |
750628d8 DN |
1408 | tree def; |
1409 | ssa_op_iter iter; | |
6de9cd9a | 1410 | |
750628d8 | 1411 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6de9cd9a | 1412 | { |
0bca51f0 DN |
1413 | fprintf (dump_file, "\nVisiting statement:\n"); |
1414 | print_generic_stmt (dump_file, stmt, dump_flags); | |
750628d8 | 1415 | fprintf (dump_file, "\n"); |
6de9cd9a | 1416 | } |
6de9cd9a | 1417 | |
07beea0d | 1418 | if (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT) |
6de9cd9a | 1419 | { |
750628d8 DN |
1420 | /* If the statement is an assignment that produces a single |
1421 | output value, evaluate its RHS to see if the lattice value of | |
1422 | its output has changed. */ | |
1423 | return visit_assignment (stmt, output_p); | |
6de9cd9a | 1424 | } |
750628d8 | 1425 | else if (TREE_CODE (stmt) == COND_EXPR || TREE_CODE (stmt) == SWITCH_EXPR) |
6de9cd9a | 1426 | { |
750628d8 DN |
1427 | /* If STMT is a conditional branch, see if we can determine |
1428 | which branch will be taken. */ | |
1429 | return visit_cond_stmt (stmt, taken_edge_p); | |
6de9cd9a | 1430 | } |
6de9cd9a | 1431 | |
750628d8 DN |
1432 | /* Any other kind of statement is not interesting for constant |
1433 | propagation and, therefore, not worth simulating. */ | |
750628d8 DN |
1434 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1435 | fprintf (dump_file, "No interesting values produced. Marked VARYING.\n"); | |
6de9cd9a | 1436 | |
750628d8 DN |
1437 | /* Definitions made by statements other than assignments to |
1438 | SSA_NAMEs represent unknown modifications to their outputs. | |
1439 | Mark them VARYING. */ | |
0bca51f0 DN |
1440 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS) |
1441 | { | |
1442 | prop_value_t v = { VARYING, NULL_TREE, NULL_TREE }; | |
1443 | set_lattice_value (def, v); | |
1444 | } | |
6de9cd9a | 1445 | |
750628d8 DN |
1446 | return SSA_PROP_VARYING; |
1447 | } | |
6de9cd9a | 1448 | |
6de9cd9a | 1449 | |
0bca51f0 | 1450 | /* Main entry point for SSA Conditional Constant Propagation. */ |
750628d8 | 1451 | |
3253eafb | 1452 | static unsigned int |
0bca51f0 | 1453 | execute_ssa_ccp (bool store_ccp) |
750628d8 | 1454 | { |
0bca51f0 | 1455 | do_store_ccp = store_ccp; |
750628d8 DN |
1456 | ccp_initialize (); |
1457 | ssa_propagate (ccp_visit_stmt, ccp_visit_phi_node); | |
3253eafb | 1458 | if (ccp_finalize ()) |
706ca88e | 1459 | return (TODO_cleanup_cfg | TODO_update_ssa | TODO_remove_unused_locals); |
3253eafb JH |
1460 | else |
1461 | return 0; | |
6de9cd9a DN |
1462 | } |
1463 | ||
173b818d | 1464 | |
c2924966 | 1465 | static unsigned int |
0bca51f0 DN |
1466 | do_ssa_ccp (void) |
1467 | { | |
3253eafb | 1468 | return execute_ssa_ccp (false); |
0bca51f0 DN |
1469 | } |
1470 | ||
1471 | ||
173b818d | 1472 | static bool |
750628d8 | 1473 | gate_ccp (void) |
173b818d | 1474 | { |
750628d8 | 1475 | return flag_tree_ccp != 0; |
173b818d BB |
1476 | } |
1477 | ||
6de9cd9a | 1478 | |
750628d8 DN |
1479 | struct tree_opt_pass pass_ccp = |
1480 | { | |
1481 | "ccp", /* name */ | |
1482 | gate_ccp, /* gate */ | |
0bca51f0 | 1483 | do_ssa_ccp, /* execute */ |
750628d8 DN |
1484 | NULL, /* sub */ |
1485 | NULL, /* next */ | |
1486 | 0, /* static_pass_number */ | |
1487 | TV_TREE_CCP, /* tv_id */ | |
7faade0f | 1488 | PROP_cfg | PROP_ssa, /* properties_required */ |
750628d8 | 1489 | 0, /* properties_provided */ |
ae07b463 | 1490 | 0, /* properties_destroyed */ |
750628d8 | 1491 | 0, /* todo_flags_start */ |
3253eafb JH |
1492 | TODO_dump_func | TODO_verify_ssa |
1493 | | TODO_verify_stmts | TODO_ggc_collect,/* todo_flags_finish */ | |
9f8628ba | 1494 | 0 /* letter */ |
750628d8 | 1495 | }; |
6de9cd9a | 1496 | |
6de9cd9a | 1497 | |
c2924966 | 1498 | static unsigned int |
0bca51f0 DN |
1499 | do_ssa_store_ccp (void) |
1500 | { | |
1501 | /* If STORE-CCP is not enabled, we just run regular CCP. */ | |
3253eafb | 1502 | return execute_ssa_ccp (flag_tree_store_ccp != 0); |
0bca51f0 DN |
1503 | } |
1504 | ||
1505 | static bool | |
1506 | gate_store_ccp (void) | |
1507 | { | |
1508 | /* STORE-CCP is enabled only with -ftree-store-ccp, but when | |
1509 | -fno-tree-store-ccp is specified, we should run regular CCP. | |
1510 | That's why the pass is enabled with either flag. */ | |
1511 | return flag_tree_store_ccp != 0 || flag_tree_ccp != 0; | |
1512 | } | |
1513 | ||
1514 | ||
1515 | struct tree_opt_pass pass_store_ccp = | |
1516 | { | |
1517 | "store_ccp", /* name */ | |
1518 | gate_store_ccp, /* gate */ | |
1519 | do_ssa_store_ccp, /* execute */ | |
1520 | NULL, /* sub */ | |
1521 | NULL, /* next */ | |
1522 | 0, /* static_pass_number */ | |
1523 | TV_TREE_STORE_CCP, /* tv_id */ | |
1524 | PROP_cfg | PROP_ssa | PROP_alias, /* properties_required */ | |
1525 | 0, /* properties_provided */ | |
ae07b463 | 1526 | 0, /* properties_destroyed */ |
0bca51f0 | 1527 | 0, /* todo_flags_start */ |
3253eafb JH |
1528 | TODO_dump_func | TODO_verify_ssa |
1529 | | TODO_verify_stmts | TODO_ggc_collect,/* todo_flags_finish */ | |
0bca51f0 DN |
1530 | 0 /* letter */ |
1531 | }; | |
1532 | ||
750628d8 DN |
1533 | /* Given a constant value VAL for bitfield FIELD, and a destination |
1534 | variable VAR, return VAL appropriately widened to fit into VAR. If | |
1535 | FIELD is wider than HOST_WIDE_INT, NULL is returned. */ | |
6de9cd9a | 1536 | |
750628d8 DN |
1537 | tree |
1538 | widen_bitfield (tree val, tree field, tree var) | |
6de9cd9a | 1539 | { |
750628d8 DN |
1540 | unsigned HOST_WIDE_INT var_size, field_size; |
1541 | tree wide_val; | |
1542 | unsigned HOST_WIDE_INT mask; | |
1543 | unsigned int i; | |
6de9cd9a | 1544 | |
750628d8 DN |
1545 | /* We can only do this if the size of the type and field and VAL are |
1546 | all constants representable in HOST_WIDE_INT. */ | |
1547 | if (!host_integerp (TYPE_SIZE (TREE_TYPE (var)), 1) | |
1548 | || !host_integerp (DECL_SIZE (field), 1) | |
1549 | || !host_integerp (val, 0)) | |
1550 | return NULL_TREE; | |
6de9cd9a | 1551 | |
750628d8 DN |
1552 | var_size = tree_low_cst (TYPE_SIZE (TREE_TYPE (var)), 1); |
1553 | field_size = tree_low_cst (DECL_SIZE (field), 1); | |
6de9cd9a | 1554 | |
750628d8 DN |
1555 | /* Give up if either the bitfield or the variable are too wide. */ |
1556 | if (field_size > HOST_BITS_PER_WIDE_INT || var_size > HOST_BITS_PER_WIDE_INT) | |
1557 | return NULL_TREE; | |
6de9cd9a | 1558 | |
1e128c5f | 1559 | gcc_assert (var_size >= field_size); |
6de9cd9a | 1560 | |
750628d8 DN |
1561 | /* If the sign bit of the value is not set or the field's type is unsigned, |
1562 | just mask off the high order bits of the value. */ | |
1563 | if (DECL_UNSIGNED (field) | |
1564 | || !(tree_low_cst (val, 0) & (((HOST_WIDE_INT)1) << (field_size - 1)))) | |
1565 | { | |
1566 | /* Zero extension. Build a mask with the lower 'field_size' bits | |
1567 | set and a BIT_AND_EXPR node to clear the high order bits of | |
1568 | the value. */ | |
1569 | for (i = 0, mask = 0; i < field_size; i++) | |
1570 | mask |= ((HOST_WIDE_INT) 1) << i; | |
6de9cd9a | 1571 | |
f457cf40 JM |
1572 | wide_val = fold_build2 (BIT_AND_EXPR, TREE_TYPE (var), val, |
1573 | build_int_cst (TREE_TYPE (var), mask)); | |
6de9cd9a | 1574 | } |
750628d8 | 1575 | else |
173b818d | 1576 | { |
750628d8 DN |
1577 | /* Sign extension. Create a mask with the upper 'field_size' |
1578 | bits set and a BIT_IOR_EXPR to set the high order bits of the | |
1579 | value. */ | |
1580 | for (i = 0, mask = 0; i < (var_size - field_size); i++) | |
1581 | mask |= ((HOST_WIDE_INT) 1) << (var_size - i - 1); | |
1582 | ||
f457cf40 JM |
1583 | wide_val = fold_build2 (BIT_IOR_EXPR, TREE_TYPE (var), val, |
1584 | build_int_cst (TREE_TYPE (var), mask)); | |
173b818d | 1585 | } |
6de9cd9a | 1586 | |
f457cf40 | 1587 | return wide_val; |
6de9cd9a DN |
1588 | } |
1589 | ||
750628d8 | 1590 | |
6de9cd9a DN |
1591 | /* A subroutine of fold_stmt_r. Attempts to fold *(A+O) to A[X]. |
1592 | BASE is an array type. OFFSET is a byte displacement. ORIG_TYPE | |
9cf737f8 | 1593 | is the desired result type. */ |
6de9cd9a DN |
1594 | |
1595 | static tree | |
1596 | maybe_fold_offset_to_array_ref (tree base, tree offset, tree orig_type) | |
1597 | { | |
891fc5e9 | 1598 | tree min_idx, idx, idx_type, elt_offset = integer_zero_node; |
44de5aeb | 1599 | tree array_type, elt_type, elt_size; |
3097760b | 1600 | tree domain_type; |
44de5aeb RK |
1601 | |
1602 | /* If BASE is an ARRAY_REF, we can pick up another offset (this time | |
1603 | measured in units of the size of elements type) from that ARRAY_REF). | |
1604 | We can't do anything if either is variable. | |
1605 | ||
1606 | The case we handle here is *(&A[N]+O). */ | |
1607 | if (TREE_CODE (base) == ARRAY_REF) | |
1608 | { | |
1609 | tree low_bound = array_ref_low_bound (base); | |
1610 | ||
1611 | elt_offset = TREE_OPERAND (base, 1); | |
1612 | if (TREE_CODE (low_bound) != INTEGER_CST | |
1613 | || TREE_CODE (elt_offset) != INTEGER_CST) | |
1614 | return NULL_TREE; | |
1615 | ||
1616 | elt_offset = int_const_binop (MINUS_EXPR, elt_offset, low_bound, 0); | |
1617 | base = TREE_OPERAND (base, 0); | |
1618 | } | |
6de9cd9a DN |
1619 | |
1620 | /* Ignore stupid user tricks of indexing non-array variables. */ | |
1621 | array_type = TREE_TYPE (base); | |
1622 | if (TREE_CODE (array_type) != ARRAY_TYPE) | |
1623 | return NULL_TREE; | |
1624 | elt_type = TREE_TYPE (array_type); | |
f4088621 | 1625 | if (!useless_type_conversion_p (orig_type, elt_type)) |
6de9cd9a | 1626 | return NULL_TREE; |
891fc5e9 RG |
1627 | |
1628 | /* Use signed size type for intermediate computation on the index. */ | |
1629 | idx_type = signed_type_for (size_type_node); | |
1630 | ||
44de5aeb RK |
1631 | /* If OFFSET and ELT_OFFSET are zero, we don't care about the size of the |
1632 | element type (so we can use the alignment if it's not constant). | |
1633 | Otherwise, compute the offset as an index by using a division. If the | |
1634 | division isn't exact, then don't do anything. */ | |
6de9cd9a | 1635 | elt_size = TYPE_SIZE_UNIT (elt_type); |
fe9821b8 JH |
1636 | if (!elt_size) |
1637 | return NULL; | |
44de5aeb RK |
1638 | if (integer_zerop (offset)) |
1639 | { | |
1640 | if (TREE_CODE (elt_size) != INTEGER_CST) | |
1641 | elt_size = size_int (TYPE_ALIGN (elt_type)); | |
6de9cd9a | 1642 | |
891fc5e9 | 1643 | idx = build_int_cst (idx_type, 0); |
44de5aeb RK |
1644 | } |
1645 | else | |
1646 | { | |
1647 | unsigned HOST_WIDE_INT lquo, lrem; | |
1648 | HOST_WIDE_INT hquo, hrem; | |
891fc5e9 | 1649 | double_int soffset; |
44de5aeb | 1650 | |
891fc5e9 RG |
1651 | /* The final array offset should be signed, so we need |
1652 | to sign-extend the (possibly pointer) offset here | |
1653 | and use signed division. */ | |
1654 | soffset = double_int_sext (tree_to_double_int (offset), | |
1655 | TYPE_PRECISION (TREE_TYPE (offset))); | |
44de5aeb | 1656 | if (TREE_CODE (elt_size) != INTEGER_CST |
891fc5e9 RG |
1657 | || div_and_round_double (TRUNC_DIV_EXPR, 0, |
1658 | soffset.low, soffset.high, | |
44de5aeb RK |
1659 | TREE_INT_CST_LOW (elt_size), |
1660 | TREE_INT_CST_HIGH (elt_size), | |
1661 | &lquo, &hquo, &lrem, &hrem) | |
1662 | || lrem || hrem) | |
1663 | return NULL_TREE; | |
6de9cd9a | 1664 | |
891fc5e9 | 1665 | idx = build_int_cst_wide (idx_type, lquo, hquo); |
44de5aeb RK |
1666 | } |
1667 | ||
1668 | /* Assume the low bound is zero. If there is a domain type, get the | |
1669 | low bound, if any, convert the index into that type, and add the | |
1670 | low bound. */ | |
891fc5e9 | 1671 | min_idx = build_int_cst (idx_type, 0); |
3097760b JH |
1672 | domain_type = TYPE_DOMAIN (array_type); |
1673 | if (domain_type) | |
6de9cd9a | 1674 | { |
3097760b | 1675 | idx_type = domain_type; |
891fc5e9 RG |
1676 | if (TYPE_MIN_VALUE (idx_type)) |
1677 | min_idx = TYPE_MIN_VALUE (idx_type); | |
44de5aeb | 1678 | else |
891fc5e9 | 1679 | min_idx = fold_convert (idx_type, min_idx); |
44de5aeb RK |
1680 | |
1681 | if (TREE_CODE (min_idx) != INTEGER_CST) | |
1682 | return NULL_TREE; | |
1683 | ||
891fc5e9 | 1684 | elt_offset = fold_convert (idx_type, elt_offset); |
6de9cd9a DN |
1685 | } |
1686 | ||
44de5aeb RK |
1687 | if (!integer_zerop (min_idx)) |
1688 | idx = int_const_binop (PLUS_EXPR, idx, min_idx, 0); | |
1689 | if (!integer_zerop (elt_offset)) | |
1690 | idx = int_const_binop (PLUS_EXPR, idx, elt_offset, 0); | |
1691 | ||
891fc5e9 RG |
1692 | /* Make sure to possibly truncate late after offsetting. */ |
1693 | idx = fold_convert (idx_type, idx); | |
1694 | ||
3097760b JH |
1695 | /* We don't want to construct access past array bounds. For example |
1696 | char *(c[4]); | |
1697 | ||
1698 | c[3][2]; should not be simplified into (*c)[14] or tree-vrp will give false | |
1699 | warning. */ | |
1700 | if (domain_type && TYPE_MAX_VALUE (domain_type) | |
1701 | && TREE_CODE (TYPE_MAX_VALUE (domain_type)) == INTEGER_CST) | |
1702 | { | |
1703 | tree up_bound = TYPE_MAX_VALUE (domain_type); | |
1704 | ||
1705 | if (tree_int_cst_lt (up_bound, idx) | |
1706 | /* Accesses after the end of arrays of size 0 (gcc | |
1707 | extension) and 1 are likely intentional ("struct | |
1708 | hack"). */ | |
1709 | && compare_tree_int (up_bound, 1) > 0) | |
1710 | return NULL_TREE; | |
1711 | } | |
1712 | ||
04d86531 | 1713 | return build4 (ARRAY_REF, elt_type, base, idx, NULL_TREE, NULL_TREE); |
6de9cd9a DN |
1714 | } |
1715 | ||
750628d8 | 1716 | |
fe9821b8 | 1717 | /* Attempt to fold *(S+O) to S.X. |
6de9cd9a DN |
1718 | BASE is a record type. OFFSET is a byte displacement. ORIG_TYPE |
1719 | is the desired result type. */ | |
6de9cd9a | 1720 | |
fe9821b8 | 1721 | static tree |
6de9cd9a DN |
1722 | maybe_fold_offset_to_component_ref (tree record_type, tree base, tree offset, |
1723 | tree orig_type, bool base_is_ptr) | |
1724 | { | |
f34fa464 | 1725 | tree f, t, field_type, tail_array_field, field_offset; |
6e6e19cb JH |
1726 | tree ret; |
1727 | tree new_base; | |
6de9cd9a DN |
1728 | |
1729 | if (TREE_CODE (record_type) != RECORD_TYPE | |
1730 | && TREE_CODE (record_type) != UNION_TYPE | |
1731 | && TREE_CODE (record_type) != QUAL_UNION_TYPE) | |
1732 | return NULL_TREE; | |
1733 | ||
1734 | /* Short-circuit silly cases. */ | |
f4088621 | 1735 | if (useless_type_conversion_p (record_type, orig_type)) |
6de9cd9a DN |
1736 | return NULL_TREE; |
1737 | ||
1738 | tail_array_field = NULL_TREE; | |
1739 | for (f = TYPE_FIELDS (record_type); f ; f = TREE_CHAIN (f)) | |
1740 | { | |
1741 | int cmp; | |
1742 | ||
1743 | if (TREE_CODE (f) != FIELD_DECL) | |
1744 | continue; | |
1745 | if (DECL_BIT_FIELD (f)) | |
1746 | continue; | |
f34fa464 | 1747 | |
fe9821b8 JH |
1748 | if (!DECL_FIELD_OFFSET (f)) |
1749 | continue; | |
f34fa464 ZD |
1750 | field_offset = byte_position (f); |
1751 | if (TREE_CODE (field_offset) != INTEGER_CST) | |
6de9cd9a DN |
1752 | continue; |
1753 | ||
1754 | /* ??? Java creates "interesting" fields for representing base classes. | |
1755 | They have no name, and have no context. With no context, we get into | |
1756 | trouble with nonoverlapping_component_refs_p. Skip them. */ | |
1757 | if (!DECL_FIELD_CONTEXT (f)) | |
1758 | continue; | |
1759 | ||
1760 | /* The previous array field isn't at the end. */ | |
1761 | tail_array_field = NULL_TREE; | |
1762 | ||
1763 | /* Check to see if this offset overlaps with the field. */ | |
f34fa464 | 1764 | cmp = tree_int_cst_compare (field_offset, offset); |
6de9cd9a DN |
1765 | if (cmp > 0) |
1766 | continue; | |
1767 | ||
1768 | field_type = TREE_TYPE (f); | |
6de9cd9a DN |
1769 | |
1770 | /* Here we exactly match the offset being checked. If the types match, | |
1771 | then we can return that field. */ | |
53dba802 | 1772 | if (cmp == 0 |
f4088621 | 1773 | && useless_type_conversion_p (orig_type, field_type)) |
6de9cd9a DN |
1774 | { |
1775 | if (base_is_ptr) | |
1776 | base = build1 (INDIRECT_REF, record_type, base); | |
b4257cfc | 1777 | t = build3 (COMPONENT_REF, field_type, base, f, NULL_TREE); |
6de9cd9a DN |
1778 | return t; |
1779 | } | |
53dba802 ZD |
1780 | |
1781 | /* Don't care about offsets into the middle of scalars. */ | |
1782 | if (!AGGREGATE_TYPE_P (field_type)) | |
1783 | continue; | |
6de9cd9a | 1784 | |
53dba802 ZD |
1785 | /* Check for array at the end of the struct. This is often |
1786 | used as for flexible array members. We should be able to | |
1787 | turn this into an array access anyway. */ | |
1788 | if (TREE_CODE (field_type) == ARRAY_TYPE) | |
1789 | tail_array_field = f; | |
1790 | ||
1791 | /* Check the end of the field against the offset. */ | |
1792 | if (!DECL_SIZE_UNIT (f) | |
1793 | || TREE_CODE (DECL_SIZE_UNIT (f)) != INTEGER_CST) | |
1794 | continue; | |
1795 | t = int_const_binop (MINUS_EXPR, offset, field_offset, 1); | |
1796 | if (!tree_int_cst_lt (t, DECL_SIZE_UNIT (f))) | |
1797 | continue; | |
6de9cd9a | 1798 | |
53dba802 ZD |
1799 | /* If we matched, then set offset to the displacement into |
1800 | this field. */ | |
6e6e19cb JH |
1801 | if (base_is_ptr) |
1802 | new_base = build1 (INDIRECT_REF, record_type, base); | |
1803 | else | |
1804 | new_base = base; | |
1805 | new_base = build3 (COMPONENT_REF, field_type, new_base, f, NULL_TREE); | |
1806 | ||
1807 | /* Recurse to possibly find the match. */ | |
1808 | ret = maybe_fold_offset_to_array_ref (new_base, t, orig_type); | |
1809 | if (ret) | |
1810 | return ret; | |
1811 | ret = maybe_fold_offset_to_component_ref (field_type, new_base, t, | |
1812 | orig_type, false); | |
1813 | if (ret) | |
1814 | return ret; | |
6de9cd9a DN |
1815 | } |
1816 | ||
1817 | if (!tail_array_field) | |
1818 | return NULL_TREE; | |
1819 | ||
1820 | f = tail_array_field; | |
1821 | field_type = TREE_TYPE (f); | |
53dba802 | 1822 | offset = int_const_binop (MINUS_EXPR, offset, byte_position (f), 1); |
6de9cd9a | 1823 | |
6de9cd9a | 1824 | /* If we get here, we've got an aggregate field, and a possibly |
1ea7e6ad | 1825 | nonzero offset into them. Recurse and hope for a valid match. */ |
6de9cd9a DN |
1826 | if (base_is_ptr) |
1827 | base = build1 (INDIRECT_REF, record_type, base); | |
b4257cfc | 1828 | base = build3 (COMPONENT_REF, field_type, base, f, NULL_TREE); |
6de9cd9a DN |
1829 | |
1830 | t = maybe_fold_offset_to_array_ref (base, offset, orig_type); | |
1831 | if (t) | |
1832 | return t; | |
1833 | return maybe_fold_offset_to_component_ref (field_type, base, offset, | |
1834 | orig_type, false); | |
1835 | } | |
1836 | ||
fe9821b8 JH |
1837 | /* Attempt to express (ORIG_TYPE)BASE+OFFSET as BASE->field_of_orig_type |
1838 | or BASE[index] or by combination of those. | |
1839 | ||
1840 | Before attempting the conversion strip off existing ADDR_EXPRs and | |
1841 | handled component refs. */ | |
1842 | ||
1843 | tree | |
1844 | maybe_fold_offset_to_reference (tree base, tree offset, tree orig_type) | |
1845 | { | |
1846 | tree ret; | |
1847 | tree type; | |
1848 | bool base_is_ptr = true; | |
1849 | ||
1850 | STRIP_NOPS (base); | |
1851 | if (TREE_CODE (base) == ADDR_EXPR) | |
1852 | { | |
1853 | base_is_ptr = false; | |
1854 | ||
1855 | base = TREE_OPERAND (base, 0); | |
1856 | ||
1857 | /* Handle case where existing COMPONENT_REF pick e.g. wrong field of union, | |
1858 | so it needs to be removed and new COMPONENT_REF constructed. | |
1859 | The wrong COMPONENT_REF are often constructed by folding the | |
1860 | (type *)&object within the expression (type *)&object+offset */ | |
1861 | if (handled_component_p (base) && 0) | |
1862 | { | |
1863 | HOST_WIDE_INT sub_offset, size, maxsize; | |
1864 | tree newbase; | |
1865 | newbase = get_ref_base_and_extent (base, &sub_offset, | |
1866 | &size, &maxsize); | |
1867 | gcc_assert (newbase); | |
1868 | gcc_assert (!(sub_offset & (BITS_PER_UNIT - 1))); | |
1869 | if (size == maxsize) | |
1870 | { | |
1871 | base = newbase; | |
1872 | if (sub_offset) | |
1873 | offset = int_const_binop (PLUS_EXPR, offset, | |
1874 | build_int_cst (TREE_TYPE (offset), | |
1875 | sub_offset / BITS_PER_UNIT), 1); | |
1876 | } | |
1877 | } | |
f4088621 | 1878 | if (useless_type_conversion_p (orig_type, TREE_TYPE (base)) |
fe9821b8 JH |
1879 | && integer_zerop (offset)) |
1880 | return base; | |
1881 | type = TREE_TYPE (base); | |
1882 | } | |
1883 | else | |
1884 | { | |
1885 | base_is_ptr = true; | |
1886 | if (!POINTER_TYPE_P (TREE_TYPE (base))) | |
1887 | return NULL_TREE; | |
1888 | type = TREE_TYPE (TREE_TYPE (base)); | |
1889 | } | |
1890 | ret = maybe_fold_offset_to_component_ref (type, base, offset, | |
1891 | orig_type, base_is_ptr); | |
1892 | if (!ret) | |
1893 | { | |
1894 | if (base_is_ptr) | |
1895 | base = build1 (INDIRECT_REF, type, base); | |
1896 | ret = maybe_fold_offset_to_array_ref (base, offset, orig_type); | |
1897 | } | |
1898 | return ret; | |
1899 | } | |
750628d8 | 1900 | |
6de9cd9a DN |
1901 | /* A subroutine of fold_stmt_r. Attempt to simplify *(BASE+OFFSET). |
1902 | Return the simplified expression, or NULL if nothing could be done. */ | |
1903 | ||
1904 | static tree | |
1905 | maybe_fold_stmt_indirect (tree expr, tree base, tree offset) | |
1906 | { | |
1907 | tree t; | |
cbf8d355 | 1908 | bool volatile_p = TREE_THIS_VOLATILE (expr); |
6de9cd9a DN |
1909 | |
1910 | /* We may well have constructed a double-nested PLUS_EXPR via multiple | |
1911 | substitutions. Fold that down to one. Remove NON_LVALUE_EXPRs that | |
1912 | are sometimes added. */ | |
1913 | base = fold (base); | |
ff7c8597 | 1914 | STRIP_TYPE_NOPS (base); |
6de9cd9a DN |
1915 | TREE_OPERAND (expr, 0) = base; |
1916 | ||
1917 | /* One possibility is that the address reduces to a string constant. */ | |
1918 | t = fold_read_from_constant_string (expr); | |
1919 | if (t) | |
1920 | return t; | |
1921 | ||
5be014d5 AP |
1922 | /* Add in any offset from a POINTER_PLUS_EXPR. */ |
1923 | if (TREE_CODE (base) == POINTER_PLUS_EXPR) | |
6de9cd9a DN |
1924 | { |
1925 | tree offset2; | |
1926 | ||
1927 | offset2 = TREE_OPERAND (base, 1); | |
1928 | if (TREE_CODE (offset2) != INTEGER_CST) | |
1929 | return NULL_TREE; | |
1930 | base = TREE_OPERAND (base, 0); | |
1931 | ||
5be014d5 AP |
1932 | offset = fold_convert (sizetype, |
1933 | int_const_binop (PLUS_EXPR, offset, offset2, 1)); | |
6de9cd9a DN |
1934 | } |
1935 | ||
1936 | if (TREE_CODE (base) == ADDR_EXPR) | |
1937 | { | |
fe9821b8 JH |
1938 | tree base_addr = base; |
1939 | ||
6de9cd9a DN |
1940 | /* Strip the ADDR_EXPR. */ |
1941 | base = TREE_OPERAND (base, 0); | |
1942 | ||
0534fa56 RH |
1943 | /* Fold away CONST_DECL to its value, if the type is scalar. */ |
1944 | if (TREE_CODE (base) == CONST_DECL | |
688e936d | 1945 | && ccp_decl_initial_min_invariant (DECL_INITIAL (base))) |
0534fa56 RH |
1946 | return DECL_INITIAL (base); |
1947 | ||
6de9cd9a | 1948 | /* Try folding *(&B+O) to B.X. */ |
fe9821b8 JH |
1949 | t = maybe_fold_offset_to_reference (base_addr, offset, |
1950 | TREE_TYPE (expr)); | |
6de9cd9a | 1951 | if (t) |
cbf8d355 RG |
1952 | { |
1953 | TREE_THIS_VOLATILE (t) = volatile_p; | |
1954 | return t; | |
1955 | } | |
6de9cd9a DN |
1956 | } |
1957 | else | |
1958 | { | |
1959 | /* We can get here for out-of-range string constant accesses, | |
1960 | such as "_"[3]. Bail out of the entire substitution search | |
1961 | and arrange for the entire statement to be replaced by a | |
aabcd309 | 1962 | call to __builtin_trap. In all likelihood this will all be |
6de9cd9a DN |
1963 | constant-folded away, but in the meantime we can't leave with |
1964 | something that get_expr_operands can't understand. */ | |
1965 | ||
1966 | t = base; | |
1967 | STRIP_NOPS (t); | |
1968 | if (TREE_CODE (t) == ADDR_EXPR | |
1969 | && TREE_CODE (TREE_OPERAND (t, 0)) == STRING_CST) | |
1970 | { | |
1971 | /* FIXME: Except that this causes problems elsewhere with dead | |
0e61db61 | 1972 | code not being deleted, and we die in the rtl expanders |
6de9cd9a DN |
1973 | because we failed to remove some ssa_name. In the meantime, |
1974 | just return zero. */ | |
1975 | /* FIXME2: This condition should be signaled by | |
1976 | fold_read_from_constant_string directly, rather than | |
1977 | re-checking for it here. */ | |
1978 | return integer_zero_node; | |
1979 | } | |
1980 | ||
1981 | /* Try folding *(B+O) to B->X. Still an improvement. */ | |
1982 | if (POINTER_TYPE_P (TREE_TYPE (base))) | |
1983 | { | |
fe9821b8 JH |
1984 | t = maybe_fold_offset_to_reference (base, offset, |
1985 | TREE_TYPE (expr)); | |
6de9cd9a DN |
1986 | if (t) |
1987 | return t; | |
1988 | } | |
1989 | } | |
1990 | ||
1991 | /* Otherwise we had an offset that we could not simplify. */ | |
1992 | return NULL_TREE; | |
1993 | } | |
1994 | ||
750628d8 | 1995 | |
5be014d5 | 1996 | /* A subroutine of fold_stmt_r. EXPR is a POINTER_PLUS_EXPR. |
6de9cd9a DN |
1997 | |
1998 | A quaint feature extant in our address arithmetic is that there | |
1999 | can be hidden type changes here. The type of the result need | |
2000 | not be the same as the type of the input pointer. | |
2001 | ||
2002 | What we're after here is an expression of the form | |
2003 | (T *)(&array + const) | |
2004 | where the cast doesn't actually exist, but is implicit in the | |
5be014d5 | 2005 | type of the POINTER_PLUS_EXPR. We'd like to turn this into |
6de9cd9a DN |
2006 | &array[x] |
2007 | which may be able to propagate further. */ | |
2008 | ||
2009 | static tree | |
2010 | maybe_fold_stmt_addition (tree expr) | |
2011 | { | |
2012 | tree op0 = TREE_OPERAND (expr, 0); | |
2013 | tree op1 = TREE_OPERAND (expr, 1); | |
2014 | tree ptr_type = TREE_TYPE (expr); | |
2015 | tree ptd_type; | |
2016 | tree t; | |
6de9cd9a | 2017 | |
5be014d5 AP |
2018 | gcc_assert (TREE_CODE (expr) == POINTER_PLUS_EXPR); |
2019 | ||
6de9cd9a DN |
2020 | /* It had better be a constant. */ |
2021 | if (TREE_CODE (op1) != INTEGER_CST) | |
2022 | return NULL_TREE; | |
2023 | /* The first operand should be an ADDR_EXPR. */ | |
2024 | if (TREE_CODE (op0) != ADDR_EXPR) | |
2025 | return NULL_TREE; | |
2026 | op0 = TREE_OPERAND (op0, 0); | |
2027 | ||
2028 | /* If the first operand is an ARRAY_REF, expand it so that we can fold | |
2029 | the offset into it. */ | |
2030 | while (TREE_CODE (op0) == ARRAY_REF) | |
2031 | { | |
2032 | tree array_obj = TREE_OPERAND (op0, 0); | |
2033 | tree array_idx = TREE_OPERAND (op0, 1); | |
2034 | tree elt_type = TREE_TYPE (op0); | |
2035 | tree elt_size = TYPE_SIZE_UNIT (elt_type); | |
2036 | tree min_idx; | |
2037 | ||
2038 | if (TREE_CODE (array_idx) != INTEGER_CST) | |
2039 | break; | |
2040 | if (TREE_CODE (elt_size) != INTEGER_CST) | |
2041 | break; | |
2042 | ||
2043 | /* Un-bias the index by the min index of the array type. */ | |
2044 | min_idx = TYPE_DOMAIN (TREE_TYPE (array_obj)); | |
2045 | if (min_idx) | |
2046 | { | |
2047 | min_idx = TYPE_MIN_VALUE (min_idx); | |
2048 | if (min_idx) | |
2049 | { | |
44de5aeb RK |
2050 | if (TREE_CODE (min_idx) != INTEGER_CST) |
2051 | break; | |
2052 | ||
b6f65e3c | 2053 | array_idx = fold_convert (TREE_TYPE (min_idx), array_idx); |
6de9cd9a DN |
2054 | if (!integer_zerop (min_idx)) |
2055 | array_idx = int_const_binop (MINUS_EXPR, array_idx, | |
2056 | min_idx, 0); | |
2057 | } | |
2058 | } | |
2059 | ||
2060 | /* Convert the index to a byte offset. */ | |
b6f65e3c | 2061 | array_idx = fold_convert (sizetype, array_idx); |
6de9cd9a DN |
2062 | array_idx = int_const_binop (MULT_EXPR, array_idx, elt_size, 0); |
2063 | ||
2064 | /* Update the operands for the next round, or for folding. */ | |
5be014d5 | 2065 | op1 = int_const_binop (PLUS_EXPR, |
6de9cd9a | 2066 | array_idx, op1, 0); |
6de9cd9a DN |
2067 | op0 = array_obj; |
2068 | } | |
2069 | ||
6de9cd9a DN |
2070 | ptd_type = TREE_TYPE (ptr_type); |
2071 | ||
2072 | /* At which point we can try some of the same things as for indirects. */ | |
2073 | t = maybe_fold_offset_to_array_ref (op0, op1, ptd_type); | |
2074 | if (!t) | |
2075 | t = maybe_fold_offset_to_component_ref (TREE_TYPE (op0), op0, op1, | |
2076 | ptd_type, false); | |
2077 | if (t) | |
2078 | t = build1 (ADDR_EXPR, ptr_type, t); | |
2079 | ||
2080 | return t; | |
2081 | } | |
2082 | ||
622f91ba JL |
2083 | /* For passing state through walk_tree into fold_stmt_r and its |
2084 | children. */ | |
2085 | ||
2086 | struct fold_stmt_r_data | |
2087 | { | |
6ac01510 ILT |
2088 | tree stmt; |
2089 | bool *changed_p; | |
2090 | bool *inside_addr_expr_p; | |
622f91ba JL |
2091 | }; |
2092 | ||
6de9cd9a DN |
2093 | /* Subroutine of fold_stmt called via walk_tree. We perform several |
2094 | simplifications of EXPR_P, mostly having to do with pointer arithmetic. */ | |
2095 | ||
2096 | static tree | |
2097 | fold_stmt_r (tree *expr_p, int *walk_subtrees, void *data) | |
2098 | { | |
858904db | 2099 | struct fold_stmt_r_data *fold_stmt_r_data = (struct fold_stmt_r_data *) data; |
622f91ba JL |
2100 | bool *inside_addr_expr_p = fold_stmt_r_data->inside_addr_expr_p; |
2101 | bool *changed_p = fold_stmt_r_data->changed_p; | |
6de9cd9a | 2102 | tree expr = *expr_p, t; |
6aaa4013 | 2103 | bool volatile_p = TREE_THIS_VOLATILE (expr); |
6de9cd9a DN |
2104 | |
2105 | /* ??? It'd be nice if walk_tree had a pre-order option. */ | |
2106 | switch (TREE_CODE (expr)) | |
2107 | { | |
2108 | case INDIRECT_REF: | |
2109 | t = walk_tree (&TREE_OPERAND (expr, 0), fold_stmt_r, data, NULL); | |
2110 | if (t) | |
2111 | return t; | |
2112 | *walk_subtrees = 0; | |
2113 | ||
2114 | t = maybe_fold_stmt_indirect (expr, TREE_OPERAND (expr, 0), | |
2115 | integer_zero_node); | |
2116 | break; | |
2117 | ||
fe9821b8 JH |
2118 | case NOP_EXPR: |
2119 | t = walk_tree (&TREE_OPERAND (expr, 0), fold_stmt_r, data, NULL); | |
2120 | if (t) | |
2121 | return t; | |
2122 | *walk_subtrees = 0; | |
2123 | ||
2124 | if (POINTER_TYPE_P (TREE_TYPE (expr)) | |
2125 | && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (expr, 0))) | |
2126 | && (t = maybe_fold_offset_to_reference | |
2127 | (TREE_OPERAND (expr, 0), | |
2128 | integer_zero_node, | |
2129 | TREE_TYPE (TREE_TYPE (expr))))) | |
fa2050d2 RG |
2130 | { |
2131 | tree ptr_type = build_pointer_type (TREE_TYPE (t)); | |
2132 | if (!useless_type_conversion_p (TREE_TYPE (expr), ptr_type)) | |
2133 | return NULL_TREE; | |
2134 | t = build_fold_addr_expr_with_type (t, ptr_type); | |
2135 | } | |
fe9821b8 JH |
2136 | break; |
2137 | ||
622f91ba | 2138 | /* ??? Could handle more ARRAY_REFs here, as a variant of INDIRECT_REF. |
6de9cd9a DN |
2139 | We'd only want to bother decomposing an existing ARRAY_REF if |
2140 | the base array is found to have another offset contained within. | |
2141 | Otherwise we'd be wasting time. */ | |
622f91ba JL |
2142 | case ARRAY_REF: |
2143 | /* If we are not processing expressions found within an | |
2144 | ADDR_EXPR, then we can fold constant array references. */ | |
2145 | if (!*inside_addr_expr_p) | |
2146 | t = fold_read_from_constant_string (expr); | |
2147 | else | |
2148 | t = NULL; | |
2149 | break; | |
6de9cd9a DN |
2150 | |
2151 | case ADDR_EXPR: | |
622f91ba | 2152 | *inside_addr_expr_p = true; |
6de9cd9a | 2153 | t = walk_tree (&TREE_OPERAND (expr, 0), fold_stmt_r, data, NULL); |
622f91ba | 2154 | *inside_addr_expr_p = false; |
6de9cd9a DN |
2155 | if (t) |
2156 | return t; | |
2157 | *walk_subtrees = 0; | |
2158 | ||
2159 | /* Set TREE_INVARIANT properly so that the value is properly | |
2160 | considered constant, and so gets propagated as expected. */ | |
2161 | if (*changed_p) | |
127203ac | 2162 | recompute_tree_invariant_for_addr_expr (expr); |
6de9cd9a DN |
2163 | return NULL_TREE; |
2164 | ||
5be014d5 | 2165 | case POINTER_PLUS_EXPR: |
6de9cd9a DN |
2166 | t = walk_tree (&TREE_OPERAND (expr, 0), fold_stmt_r, data, NULL); |
2167 | if (t) | |
2168 | return t; | |
2169 | t = walk_tree (&TREE_OPERAND (expr, 1), fold_stmt_r, data, NULL); | |
2170 | if (t) | |
2171 | return t; | |
2172 | *walk_subtrees = 0; | |
2173 | ||
2174 | t = maybe_fold_stmt_addition (expr); | |
2175 | break; | |
2176 | ||
2177 | case COMPONENT_REF: | |
2178 | t = walk_tree (&TREE_OPERAND (expr, 0), fold_stmt_r, data, NULL); | |
2179 | if (t) | |
2180 | return t; | |
2181 | *walk_subtrees = 0; | |
2182 | ||
fa27426e RH |
2183 | /* Make sure the FIELD_DECL is actually a field in the type on the lhs. |
2184 | We've already checked that the records are compatible, so we should | |
2185 | come up with a set of compatible fields. */ | |
2186 | { | |
2187 | tree expr_record = TREE_TYPE (TREE_OPERAND (expr, 0)); | |
2188 | tree expr_field = TREE_OPERAND (expr, 1); | |
2189 | ||
2190 | if (DECL_FIELD_CONTEXT (expr_field) != TYPE_MAIN_VARIANT (expr_record)) | |
2191 | { | |
2192 | expr_field = find_compatible_field (expr_record, expr_field); | |
2193 | TREE_OPERAND (expr, 1) = expr_field; | |
2194 | } | |
2195 | } | |
6de9cd9a DN |
2196 | break; |
2197 | ||
ac182688 ZD |
2198 | case TARGET_MEM_REF: |
2199 | t = maybe_fold_tmr (expr); | |
2200 | break; | |
2201 | ||
f393e7f5 RG |
2202 | case COND_EXPR: |
2203 | if (COMPARISON_CLASS_P (TREE_OPERAND (expr, 0))) | |
2204 | { | |
2205 | tree op0 = TREE_OPERAND (expr, 0); | |
6ac01510 ILT |
2206 | tree tem; |
2207 | bool set; | |
2208 | ||
2209 | fold_defer_overflow_warnings (); | |
2210 | tem = fold_binary (TREE_CODE (op0), TREE_TYPE (op0), | |
2211 | TREE_OPERAND (op0, 0), | |
2212 | TREE_OPERAND (op0, 1)); | |
2213 | set = tem && set_rhs (expr_p, tem); | |
2214 | fold_undefer_overflow_warnings (set, fold_stmt_r_data->stmt, 0); | |
2215 | if (set) | |
5cdc4a26 RS |
2216 | { |
2217 | t = *expr_p; | |
2218 | break; | |
2219 | } | |
f393e7f5 | 2220 | } |
5cdc4a26 | 2221 | return NULL_TREE; |
f393e7f5 | 2222 | |
6de9cd9a DN |
2223 | default: |
2224 | return NULL_TREE; | |
2225 | } | |
2226 | ||
2227 | if (t) | |
2228 | { | |
6aaa4013 RG |
2229 | /* Preserve volatileness of the original expression. */ |
2230 | TREE_THIS_VOLATILE (t) = volatile_p; | |
6de9cd9a DN |
2231 | *expr_p = t; |
2232 | *changed_p = true; | |
2233 | } | |
2234 | ||
2235 | return NULL_TREE; | |
2236 | } | |
2237 | ||
6de9cd9a | 2238 | |
10a0d495 JJ |
2239 | /* Return the string length, maximum string length or maximum value of |
2240 | ARG in LENGTH. | |
2241 | If ARG is an SSA name variable, follow its use-def chains. If LENGTH | |
2242 | is not NULL and, for TYPE == 0, its value is not equal to the length | |
2243 | we determine or if we are unable to determine the length or value, | |
2244 | return false. VISITED is a bitmap of visited variables. | |
2245 | TYPE is 0 if string length should be returned, 1 for maximum string | |
2246 | length and 2 for maximum value ARG can have. */ | |
6de9cd9a | 2247 | |
06a9b53f | 2248 | static bool |
10a0d495 | 2249 | get_maxval_strlen (tree arg, tree *length, bitmap visited, int type) |
6de9cd9a | 2250 | { |
750628d8 DN |
2251 | tree var, def_stmt, val; |
2252 | ||
2253 | if (TREE_CODE (arg) != SSA_NAME) | |
06a9b53f | 2254 | { |
f255541f RC |
2255 | if (TREE_CODE (arg) == COND_EXPR) |
2256 | return get_maxval_strlen (COND_EXPR_THEN (arg), length, visited, type) | |
2257 | && get_maxval_strlen (COND_EXPR_ELSE (arg), length, visited, type); | |
2258 | ||
10a0d495 JJ |
2259 | if (type == 2) |
2260 | { | |
2261 | val = arg; | |
2262 | if (TREE_CODE (val) != INTEGER_CST | |
2263 | || tree_int_cst_sgn (val) < 0) | |
2264 | return false; | |
2265 | } | |
2266 | else | |
2267 | val = c_strlen (arg, 1); | |
750628d8 | 2268 | if (!val) |
06a9b53f | 2269 | return false; |
cd709752 | 2270 | |
10a0d495 JJ |
2271 | if (*length) |
2272 | { | |
2273 | if (type > 0) | |
2274 | { | |
2275 | if (TREE_CODE (*length) != INTEGER_CST | |
2276 | || TREE_CODE (val) != INTEGER_CST) | |
2277 | return false; | |
2278 | ||
2279 | if (tree_int_cst_lt (*length, val)) | |
2280 | *length = val; | |
2281 | return true; | |
2282 | } | |
2283 | else if (simple_cst_equal (val, *length) != 1) | |
2284 | return false; | |
2285 | } | |
6de9cd9a | 2286 | |
750628d8 DN |
2287 | *length = val; |
2288 | return true; | |
6de9cd9a | 2289 | } |
06a9b53f | 2290 | |
750628d8 DN |
2291 | /* If we were already here, break the infinite cycle. */ |
2292 | if (bitmap_bit_p (visited, SSA_NAME_VERSION (arg))) | |
2293 | return true; | |
2294 | bitmap_set_bit (visited, SSA_NAME_VERSION (arg)); | |
2295 | ||
2296 | var = arg; | |
2297 | def_stmt = SSA_NAME_DEF_STMT (var); | |
6de9cd9a | 2298 | |
750628d8 DN |
2299 | switch (TREE_CODE (def_stmt)) |
2300 | { | |
07beea0d | 2301 | case GIMPLE_MODIFY_STMT: |
750628d8 | 2302 | { |
10a0d495 JJ |
2303 | tree rhs; |
2304 | ||
750628d8 DN |
2305 | /* The RHS of the statement defining VAR must either have a |
2306 | constant length or come from another SSA_NAME with a constant | |
2307 | length. */ | |
07beea0d | 2308 | rhs = GIMPLE_STMT_OPERAND (def_stmt, 1); |
750628d8 | 2309 | STRIP_NOPS (rhs); |
10a0d495 | 2310 | return get_maxval_strlen (rhs, length, visited, type); |
750628d8 | 2311 | } |
6de9cd9a | 2312 | |
750628d8 DN |
2313 | case PHI_NODE: |
2314 | { | |
2315 | /* All the arguments of the PHI node must have the same constant | |
2316 | length. */ | |
2317 | int i; | |
6de9cd9a | 2318 | |
750628d8 DN |
2319 | for (i = 0; i < PHI_NUM_ARGS (def_stmt); i++) |
2320 | { | |
2321 | tree arg = PHI_ARG_DEF (def_stmt, i); | |
6de9cd9a | 2322 | |
750628d8 DN |
2323 | /* If this PHI has itself as an argument, we cannot |
2324 | determine the string length of this argument. However, | |
2325 | if we can find a constant string length for the other | |
2326 | PHI args then we can still be sure that this is a | |
2327 | constant string length. So be optimistic and just | |
2328 | continue with the next argument. */ | |
2329 | if (arg == PHI_RESULT (def_stmt)) | |
2330 | continue; | |
6de9cd9a | 2331 | |
10a0d495 | 2332 | if (!get_maxval_strlen (arg, length, visited, type)) |
750628d8 DN |
2333 | return false; |
2334 | } | |
6de9cd9a | 2335 | |
750628d8 | 2336 | return true; |
173b818d | 2337 | } |
6de9cd9a | 2338 | |
750628d8 DN |
2339 | default: |
2340 | break; | |
6de9cd9a DN |
2341 | } |
2342 | ||
750628d8 DN |
2343 | |
2344 | return false; | |
6de9cd9a DN |
2345 | } |
2346 | ||
2347 | ||
2348 | /* Fold builtin call FN in statement STMT. If it cannot be folded into a | |
2349 | constant, return NULL_TREE. Otherwise, return its constant value. */ | |
2350 | ||
2351 | static tree | |
2352 | ccp_fold_builtin (tree stmt, tree fn) | |
2353 | { | |
10a0d495 | 2354 | tree result, val[3]; |
5039610b | 2355 | tree callee, a; |
10a0d495 | 2356 | int arg_mask, i, type; |
a32e70c3 RS |
2357 | bitmap visited; |
2358 | bool ignore; | |
5039610b SL |
2359 | call_expr_arg_iterator iter; |
2360 | int nargs; | |
6de9cd9a | 2361 | |
07beea0d | 2362 | ignore = TREE_CODE (stmt) != GIMPLE_MODIFY_STMT; |
6de9cd9a DN |
2363 | |
2364 | /* First try the generic builtin folder. If that succeeds, return the | |
2365 | result directly. */ | |
5039610b | 2366 | result = fold_call_expr (fn, ignore); |
6de9cd9a | 2367 | if (result) |
10a0d495 JJ |
2368 | { |
2369 | if (ignore) | |
2370 | STRIP_NOPS (result); | |
2371 | return result; | |
2372 | } | |
a32e70c3 RS |
2373 | |
2374 | /* Ignore MD builtins. */ | |
5039610b | 2375 | callee = get_callee_fndecl (fn); |
a32e70c3 RS |
2376 | if (DECL_BUILT_IN_CLASS (callee) == BUILT_IN_MD) |
2377 | return NULL_TREE; | |
6de9cd9a DN |
2378 | |
2379 | /* If the builtin could not be folded, and it has no argument list, | |
2380 | we're done. */ | |
5039610b SL |
2381 | nargs = call_expr_nargs (fn); |
2382 | if (nargs == 0) | |
6de9cd9a DN |
2383 | return NULL_TREE; |
2384 | ||
2385 | /* Limit the work only for builtins we know how to simplify. */ | |
2386 | switch (DECL_FUNCTION_CODE (callee)) | |
2387 | { | |
2388 | case BUILT_IN_STRLEN: | |
2389 | case BUILT_IN_FPUTS: | |
2390 | case BUILT_IN_FPUTS_UNLOCKED: | |
10a0d495 JJ |
2391 | arg_mask = 1; |
2392 | type = 0; | |
6de9cd9a DN |
2393 | break; |
2394 | case BUILT_IN_STRCPY: | |
2395 | case BUILT_IN_STRNCPY: | |
10a0d495 JJ |
2396 | arg_mask = 2; |
2397 | type = 0; | |
2398 | break; | |
2399 | case BUILT_IN_MEMCPY_CHK: | |
2400 | case BUILT_IN_MEMPCPY_CHK: | |
2401 | case BUILT_IN_MEMMOVE_CHK: | |
2402 | case BUILT_IN_MEMSET_CHK: | |
2403 | case BUILT_IN_STRNCPY_CHK: | |
2404 | arg_mask = 4; | |
2405 | type = 2; | |
2406 | break; | |
2407 | case BUILT_IN_STRCPY_CHK: | |
2408 | case BUILT_IN_STPCPY_CHK: | |
2409 | arg_mask = 2; | |
2410 | type = 1; | |
2411 | break; | |
2412 | case BUILT_IN_SNPRINTF_CHK: | |
2413 | case BUILT_IN_VSNPRINTF_CHK: | |
2414 | arg_mask = 2; | |
2415 | type = 2; | |
6de9cd9a DN |
2416 | break; |
2417 | default: | |
2418 | return NULL_TREE; | |
2419 | } | |
2420 | ||
2421 | /* Try to use the dataflow information gathered by the CCP process. */ | |
8bdbfff5 | 2422 | visited = BITMAP_ALLOC (NULL); |
6de9cd9a | 2423 | |
10a0d495 | 2424 | memset (val, 0, sizeof (val)); |
5039610b SL |
2425 | init_call_expr_arg_iterator (fn, &iter); |
2426 | for (i = 0; arg_mask; i++, arg_mask >>= 1) | |
2427 | { | |
2428 | a = next_call_expr_arg (&iter); | |
2429 | if (arg_mask & 1) | |
2430 | { | |
2431 | bitmap_clear (visited); | |
2432 | if (!get_maxval_strlen (a, &val[i], visited, type)) | |
2433 | val[i] = NULL_TREE; | |
2434 | } | |
2435 | } | |
6de9cd9a | 2436 | |
8bdbfff5 | 2437 | BITMAP_FREE (visited); |
6de9cd9a | 2438 | |
a32e70c3 | 2439 | result = NULL_TREE; |
6de9cd9a DN |
2440 | switch (DECL_FUNCTION_CODE (callee)) |
2441 | { | |
2442 | case BUILT_IN_STRLEN: | |
10a0d495 | 2443 | if (val[0]) |
6de9cd9a | 2444 | { |
c22940cd | 2445 | tree new_val = fold_convert (TREE_TYPE (fn), val[0]); |
6de9cd9a DN |
2446 | |
2447 | /* If the result is not a valid gimple value, or not a cast | |
2448 | of a valid gimple value, then we can not use the result. */ | |
c22940cd TN |
2449 | if (is_gimple_val (new_val) |
2450 | || (is_gimple_cast (new_val) | |
2451 | && is_gimple_val (TREE_OPERAND (new_val, 0)))) | |
2452 | return new_val; | |
6de9cd9a | 2453 | } |
a32e70c3 RS |
2454 | break; |
2455 | ||
6de9cd9a | 2456 | case BUILT_IN_STRCPY: |
5039610b SL |
2457 | if (val[1] && is_gimple_val (val[1]) && nargs == 2) |
2458 | result = fold_builtin_strcpy (callee, | |
2459 | CALL_EXPR_ARG (fn, 0), | |
2460 | CALL_EXPR_ARG (fn, 1), | |
2461 | val[1]); | |
a32e70c3 RS |
2462 | break; |
2463 | ||
6de9cd9a | 2464 | case BUILT_IN_STRNCPY: |
5039610b SL |
2465 | if (val[1] && is_gimple_val (val[1]) && nargs == 3) |
2466 | result = fold_builtin_strncpy (callee, | |
2467 | CALL_EXPR_ARG (fn, 0), | |
2468 | CALL_EXPR_ARG (fn, 1), | |
2469 | CALL_EXPR_ARG (fn, 2), | |
2470 | val[1]); | |
a32e70c3 RS |
2471 | break; |
2472 | ||
6de9cd9a | 2473 | case BUILT_IN_FPUTS: |
5039610b SL |
2474 | result = fold_builtin_fputs (CALL_EXPR_ARG (fn, 0), |
2475 | CALL_EXPR_ARG (fn, 1), | |
07beea0d | 2476 | TREE_CODE (stmt) != GIMPLE_MODIFY_STMT, 0, |
10a0d495 | 2477 | val[0]); |
a32e70c3 RS |
2478 | break; |
2479 | ||
6de9cd9a | 2480 | case BUILT_IN_FPUTS_UNLOCKED: |
5039610b SL |
2481 | result = fold_builtin_fputs (CALL_EXPR_ARG (fn, 0), |
2482 | CALL_EXPR_ARG (fn, 1), | |
07beea0d | 2483 | TREE_CODE (stmt) != GIMPLE_MODIFY_STMT, 1, |
10a0d495 JJ |
2484 | val[0]); |
2485 | break; | |
2486 | ||
2487 | case BUILT_IN_MEMCPY_CHK: | |
2488 | case BUILT_IN_MEMPCPY_CHK: | |
2489 | case BUILT_IN_MEMMOVE_CHK: | |
2490 | case BUILT_IN_MEMSET_CHK: | |
2491 | if (val[2] && is_gimple_val (val[2])) | |
5039610b SL |
2492 | result = fold_builtin_memory_chk (callee, |
2493 | CALL_EXPR_ARG (fn, 0), | |
2494 | CALL_EXPR_ARG (fn, 1), | |
2495 | CALL_EXPR_ARG (fn, 2), | |
2496 | CALL_EXPR_ARG (fn, 3), | |
2497 | val[2], ignore, | |
10a0d495 JJ |
2498 | DECL_FUNCTION_CODE (callee)); |
2499 | break; | |
2500 | ||
2501 | case BUILT_IN_STRCPY_CHK: | |
2502 | case BUILT_IN_STPCPY_CHK: | |
2503 | if (val[1] && is_gimple_val (val[1])) | |
5039610b SL |
2504 | result = fold_builtin_stxcpy_chk (callee, |
2505 | CALL_EXPR_ARG (fn, 0), | |
2506 | CALL_EXPR_ARG (fn, 1), | |
2507 | CALL_EXPR_ARG (fn, 2), | |
2508 | val[1], ignore, | |
10a0d495 JJ |
2509 | DECL_FUNCTION_CODE (callee)); |
2510 | break; | |
2511 | ||
2512 | case BUILT_IN_STRNCPY_CHK: | |
2513 | if (val[2] && is_gimple_val (val[2])) | |
5039610b SL |
2514 | result = fold_builtin_strncpy_chk (CALL_EXPR_ARG (fn, 0), |
2515 | CALL_EXPR_ARG (fn, 1), | |
2516 | CALL_EXPR_ARG (fn, 2), | |
2517 | CALL_EXPR_ARG (fn, 3), | |
2518 | val[2]); | |
10a0d495 JJ |
2519 | break; |
2520 | ||
2521 | case BUILT_IN_SNPRINTF_CHK: | |
2522 | case BUILT_IN_VSNPRINTF_CHK: | |
2523 | if (val[1] && is_gimple_val (val[1])) | |
5039610b | 2524 | result = fold_builtin_snprintf_chk (fn, val[1], |
10a0d495 | 2525 | DECL_FUNCTION_CODE (callee)); |
a32e70c3 | 2526 | break; |
6de9cd9a DN |
2527 | |
2528 | default: | |
1e128c5f | 2529 | gcc_unreachable (); |
6de9cd9a DN |
2530 | } |
2531 | ||
a32e70c3 | 2532 | if (result && ignore) |
9675412f | 2533 | result = fold_ignored_result (result); |
a32e70c3 | 2534 | return result; |
6de9cd9a DN |
2535 | } |
2536 | ||
2537 | ||
206048bd | 2538 | /* Fold the statement pointed to by STMT_P. In some cases, this function may |
750628d8 DN |
2539 | replace the whole statement with a new one. Returns true iff folding |
2540 | makes any changes. */ | |
6de9cd9a | 2541 | |
750628d8 DN |
2542 | bool |
2543 | fold_stmt (tree *stmt_p) | |
6de9cd9a | 2544 | { |
750628d8 | 2545 | tree rhs, result, stmt; |
622f91ba | 2546 | struct fold_stmt_r_data fold_stmt_r_data; |
750628d8 | 2547 | bool changed = false; |
622f91ba JL |
2548 | bool inside_addr_expr = false; |
2549 | ||
6ac01510 ILT |
2550 | stmt = *stmt_p; |
2551 | ||
2552 | fold_stmt_r_data.stmt = stmt; | |
622f91ba JL |
2553 | fold_stmt_r_data.changed_p = &changed; |
2554 | fold_stmt_r_data.inside_addr_expr_p = &inside_addr_expr; | |
6de9cd9a | 2555 | |
750628d8 DN |
2556 | /* If we replaced constants and the statement makes pointer dereferences, |
2557 | then we may need to fold instances of *&VAR into VAR, etc. */ | |
622f91ba | 2558 | if (walk_tree (stmt_p, fold_stmt_r, &fold_stmt_r_data, NULL)) |
750628d8 | 2559 | { |
5039610b | 2560 | *stmt_p = build_call_expr (implicit_built_in_decls[BUILT_IN_TRAP], 0); |
6de9cd9a DN |
2561 | return true; |
2562 | } | |
2563 | ||
750628d8 DN |
2564 | rhs = get_rhs (stmt); |
2565 | if (!rhs) | |
2566 | return changed; | |
2567 | result = NULL_TREE; | |
6de9cd9a | 2568 | |
750628d8 | 2569 | if (TREE_CODE (rhs) == CALL_EXPR) |
6de9cd9a | 2570 | { |
750628d8 | 2571 | tree callee; |
6de9cd9a | 2572 | |
750628d8 DN |
2573 | /* Check for builtins that CCP can handle using information not |
2574 | available in the generic fold routines. */ | |
2575 | callee = get_callee_fndecl (rhs); | |
2576 | if (callee && DECL_BUILT_IN (callee)) | |
2577 | result = ccp_fold_builtin (stmt, rhs); | |
1809ff6b AP |
2578 | else |
2579 | { | |
2580 | /* Check for resolvable OBJ_TYPE_REF. The only sorts we can resolve | |
2581 | here are when we've propagated the address of a decl into the | |
2582 | object slot. */ | |
2583 | /* ??? Should perhaps do this in fold proper. However, doing it | |
2584 | there requires that we create a new CALL_EXPR, and that requires | |
2585 | copying EH region info to the new node. Easier to just do it | |
2586 | here where we can just smash the call operand. Also | |
2587 | CALL_EXPR_RETURN_SLOT_OPT needs to be handled correctly and | |
5039610b SL |
2588 | copied, fold_call_expr does not have not information. */ |
2589 | callee = CALL_EXPR_FN (rhs); | |
1809ff6b AP |
2590 | if (TREE_CODE (callee) == OBJ_TYPE_REF |
2591 | && lang_hooks.fold_obj_type_ref | |
2592 | && TREE_CODE (OBJ_TYPE_REF_OBJECT (callee)) == ADDR_EXPR | |
2593 | && DECL_P (TREE_OPERAND | |
2594 | (OBJ_TYPE_REF_OBJECT (callee), 0))) | |
2595 | { | |
2596 | tree t; | |
2597 | ||
2598 | /* ??? Caution: Broken ADDR_EXPR semantics means that | |
2599 | looking at the type of the operand of the addr_expr | |
2600 | can yield an array type. See silly exception in | |
2601 | check_pointer_types_r. */ | |
2602 | ||
2603 | t = TREE_TYPE (TREE_TYPE (OBJ_TYPE_REF_OBJECT (callee))); | |
2604 | t = lang_hooks.fold_obj_type_ref (callee, t); | |
2605 | if (t) | |
2606 | { | |
5039610b | 2607 | CALL_EXPR_FN (rhs) = t; |
1809ff6b AP |
2608 | changed = true; |
2609 | } | |
2610 | } | |
2611 | } | |
6de9cd9a | 2612 | } |
f255541f RC |
2613 | else if (TREE_CODE (rhs) == COND_EXPR) |
2614 | { | |
2615 | tree temp = fold (COND_EXPR_COND (rhs)); | |
2616 | if (temp != COND_EXPR_COND (rhs)) | |
2617 | result = fold_build3 (COND_EXPR, TREE_TYPE (rhs), temp, | |
2618 | COND_EXPR_THEN (rhs), COND_EXPR_ELSE (rhs)); | |
2619 | } | |
6de9cd9a | 2620 | |
750628d8 DN |
2621 | /* If we couldn't fold the RHS, hand over to the generic fold routines. */ |
2622 | if (result == NULL_TREE) | |
2623 | result = fold (rhs); | |
6de9cd9a | 2624 | |
750628d8 DN |
2625 | /* Strip away useless type conversions. Both the NON_LVALUE_EXPR that |
2626 | may have been added by fold, and "useless" type conversions that might | |
2627 | now be apparent due to propagation. */ | |
2628 | STRIP_USELESS_TYPE_CONVERSION (result); | |
2629 | ||
2630 | if (result != rhs) | |
2631 | changed |= set_rhs (stmt_p, result); | |
2632 | ||
2633 | return changed; | |
6de9cd9a DN |
2634 | } |
2635 | ||
38965eb2 ZD |
2636 | /* Perform the minimal folding on statement STMT. Only operations like |
2637 | *&x created by constant propagation are handled. The statement cannot | |
2638 | be replaced with a new one. */ | |
2639 | ||
2640 | bool | |
2641 | fold_stmt_inplace (tree stmt) | |
2642 | { | |
2643 | tree old_stmt = stmt, rhs, new_rhs; | |
622f91ba | 2644 | struct fold_stmt_r_data fold_stmt_r_data; |
38965eb2 | 2645 | bool changed = false; |
622f91ba JL |
2646 | bool inside_addr_expr = false; |
2647 | ||
6ac01510 | 2648 | fold_stmt_r_data.stmt = stmt; |
622f91ba JL |
2649 | fold_stmt_r_data.changed_p = &changed; |
2650 | fold_stmt_r_data.inside_addr_expr_p = &inside_addr_expr; | |
38965eb2 | 2651 | |
622f91ba | 2652 | walk_tree (&stmt, fold_stmt_r, &fold_stmt_r_data, NULL); |
38965eb2 ZD |
2653 | gcc_assert (stmt == old_stmt); |
2654 | ||
2655 | rhs = get_rhs (stmt); | |
2656 | if (!rhs || rhs == stmt) | |
2657 | return changed; | |
2658 | ||
2659 | new_rhs = fold (rhs); | |
43e364dd | 2660 | STRIP_USELESS_TYPE_CONVERSION (new_rhs); |
38965eb2 ZD |
2661 | if (new_rhs == rhs) |
2662 | return changed; | |
2663 | ||
2664 | changed |= set_rhs (&stmt, new_rhs); | |
2665 | gcc_assert (stmt == old_stmt); | |
2666 | ||
2667 | return changed; | |
2668 | } | |
6de9cd9a | 2669 | \f |
cb8e078d JJ |
2670 | /* Try to optimize out __builtin_stack_restore. Optimize it out |
2671 | if there is another __builtin_stack_restore in the same basic | |
2672 | block and no calls or ASM_EXPRs are in between, or if this block's | |
2673 | only outgoing edge is to EXIT_BLOCK and there are no calls or | |
2674 | ASM_EXPRs after this __builtin_stack_restore. */ | |
2675 | ||
2676 | static tree | |
2677 | optimize_stack_restore (basic_block bb, tree call, block_stmt_iterator i) | |
2678 | { | |
2679 | tree stack_save, stmt, callee; | |
2680 | ||
2681 | if (TREE_CODE (call) != CALL_EXPR | |
2682 | || call_expr_nargs (call) != 1 | |
2683 | || TREE_CODE (CALL_EXPR_ARG (call, 0)) != SSA_NAME | |
2684 | || !POINTER_TYPE_P (TREE_TYPE (CALL_EXPR_ARG (call, 0)))) | |
2685 | return NULL_TREE; | |
2686 | ||
2687 | for (bsi_next (&i); !bsi_end_p (i); bsi_next (&i)) | |
2688 | { | |
2689 | tree call; | |
2690 | ||
2691 | stmt = bsi_stmt (i); | |
2692 | if (TREE_CODE (stmt) == ASM_EXPR) | |
2693 | return NULL_TREE; | |
2694 | call = get_call_expr_in (stmt); | |
2695 | if (call == NULL) | |
2696 | continue; | |
2697 | ||
2698 | callee = get_callee_fndecl (call); | |
2699 | if (!callee || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL) | |
2700 | return NULL_TREE; | |
2701 | ||
2702 | if (DECL_FUNCTION_CODE (callee) == BUILT_IN_STACK_RESTORE) | |
2703 | break; | |
2704 | } | |
2705 | ||
2706 | if (bsi_end_p (i) | |
2707 | && (! single_succ_p (bb) | |
2708 | || single_succ_edge (bb)->dest != EXIT_BLOCK_PTR)) | |
2709 | return NULL_TREE; | |
2710 | ||
2711 | stack_save = SSA_NAME_DEF_STMT (CALL_EXPR_ARG (call, 0)); | |
2712 | if (TREE_CODE (stack_save) != GIMPLE_MODIFY_STMT | |
2713 | || GIMPLE_STMT_OPERAND (stack_save, 0) != CALL_EXPR_ARG (call, 0) | |
2714 | || TREE_CODE (GIMPLE_STMT_OPERAND (stack_save, 1)) != CALL_EXPR | |
2715 | || tree_could_throw_p (stack_save) | |
2716 | || !has_single_use (CALL_EXPR_ARG (call, 0))) | |
2717 | return NULL_TREE; | |
2718 | ||
2719 | callee = get_callee_fndecl (GIMPLE_STMT_OPERAND (stack_save, 1)); | |
2720 | if (!callee | |
2721 | || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL | |
2722 | || DECL_FUNCTION_CODE (callee) != BUILT_IN_STACK_SAVE | |
2723 | || call_expr_nargs (GIMPLE_STMT_OPERAND (stack_save, 1)) != 0) | |
2724 | return NULL_TREE; | |
2725 | ||
2726 | stmt = stack_save; | |
2727 | push_stmt_changes (&stmt); | |
2728 | if (!set_rhs (&stmt, | |
2729 | build_int_cst (TREE_TYPE (CALL_EXPR_ARG (call, 0)), 0))) | |
2730 | { | |
2731 | discard_stmt_changes (&stmt); | |
2732 | return NULL_TREE; | |
2733 | } | |
2734 | gcc_assert (stmt == stack_save); | |
2735 | pop_stmt_changes (&stmt); | |
2736 | ||
2737 | return integer_zero_node; | |
2738 | } | |
2739 | \f | |
d7bd8aeb JJ |
2740 | /* If va_list type is a simple pointer and nothing special is needed, |
2741 | optimize __builtin_va_start (&ap, 0) into ap = __builtin_next_arg (0), | |
2742 | __builtin_va_end (&ap) out as NOP and __builtin_va_copy into a simple | |
2743 | pointer assignment. */ | |
2744 | ||
2745 | static tree | |
2746 | optimize_stdarg_builtin (tree call) | |
2747 | { | |
2748 | tree callee, lhs, rhs; | |
2749 | bool va_list_simple_ptr; | |
2750 | ||
2751 | if (TREE_CODE (call) != CALL_EXPR) | |
2752 | return NULL_TREE; | |
2753 | ||
2754 | va_list_simple_ptr = POINTER_TYPE_P (va_list_type_node) | |
2755 | && (TREE_TYPE (va_list_type_node) == void_type_node | |
2756 | || TREE_TYPE (va_list_type_node) == char_type_node); | |
2757 | ||
2758 | callee = get_callee_fndecl (call); | |
2759 | switch (DECL_FUNCTION_CODE (callee)) | |
2760 | { | |
2761 | case BUILT_IN_VA_START: | |
2762 | if (!va_list_simple_ptr | |
2763 | || targetm.expand_builtin_va_start != NULL | |
2764 | || built_in_decls[BUILT_IN_NEXT_ARG] == NULL) | |
2765 | return NULL_TREE; | |
2766 | ||
2767 | if (call_expr_nargs (call) != 2) | |
2768 | return NULL_TREE; | |
2769 | ||
2770 | lhs = CALL_EXPR_ARG (call, 0); | |
2771 | if (!POINTER_TYPE_P (TREE_TYPE (lhs)) | |
2772 | || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs))) | |
2773 | != TYPE_MAIN_VARIANT (va_list_type_node)) | |
2774 | return NULL_TREE; | |
2775 | ||
2776 | lhs = build_fold_indirect_ref (lhs); | |
2777 | rhs = build_call_expr (built_in_decls[BUILT_IN_NEXT_ARG], | |
2778 | 1, integer_zero_node); | |
2779 | rhs = fold_convert (TREE_TYPE (lhs), rhs); | |
2780 | return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs); | |
2781 | ||
2782 | case BUILT_IN_VA_COPY: | |
2783 | if (!va_list_simple_ptr) | |
2784 | return NULL_TREE; | |
2785 | ||
2786 | if (call_expr_nargs (call) != 2) | |
2787 | return NULL_TREE; | |
2788 | ||
2789 | lhs = CALL_EXPR_ARG (call, 0); | |
2790 | if (!POINTER_TYPE_P (TREE_TYPE (lhs)) | |
2791 | || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs))) | |
2792 | != TYPE_MAIN_VARIANT (va_list_type_node)) | |
2793 | return NULL_TREE; | |
2794 | ||
2795 | lhs = build_fold_indirect_ref (lhs); | |
2796 | rhs = CALL_EXPR_ARG (call, 1); | |
2797 | if (TYPE_MAIN_VARIANT (TREE_TYPE (rhs)) | |
2798 | != TYPE_MAIN_VARIANT (va_list_type_node)) | |
2799 | return NULL_TREE; | |
2800 | ||
2801 | rhs = fold_convert (TREE_TYPE (lhs), rhs); | |
2802 | return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs); | |
2803 | ||
2804 | case BUILT_IN_VA_END: | |
2805 | return integer_zero_node; | |
2806 | ||
2807 | default: | |
2808 | gcc_unreachable (); | |
2809 | } | |
2810 | } | |
2811 | \f | |
b28b1600 JJ |
2812 | /* Convert EXPR into a GIMPLE value suitable for substitution on the |
2813 | RHS of an assignment. Insert the necessary statements before | |
2e929cf3 JH |
2814 | iterator *SI_P. |
2815 | When IGNORE is set, don't worry about the return value. */ | |
b28b1600 JJ |
2816 | |
2817 | static tree | |
2e929cf3 | 2818 | convert_to_gimple_builtin (block_stmt_iterator *si_p, tree expr, bool ignore) |
b28b1600 JJ |
2819 | { |
2820 | tree_stmt_iterator ti; | |
2821 | tree stmt = bsi_stmt (*si_p); | |
2822 | tree tmp, stmts = NULL; | |
2823 | ||
2824 | push_gimplify_context (); | |
2e929cf3 JH |
2825 | if (ignore) |
2826 | { | |
2827 | tmp = build_empty_stmt (); | |
2828 | gimplify_and_add (expr, &stmts); | |
2829 | } | |
2830 | else | |
2831 | tmp = get_initialized_tmp_var (expr, &stmts, NULL); | |
b28b1600 JJ |
2832 | pop_gimplify_context (NULL); |
2833 | ||
f47c96aa AM |
2834 | if (EXPR_HAS_LOCATION (stmt)) |
2835 | annotate_all_with_locus (&stmts, EXPR_LOCATION (stmt)); | |
2836 | ||
b28b1600 JJ |
2837 | /* The replacement can expose previously unreferenced variables. */ |
2838 | for (ti = tsi_start (stmts); !tsi_end_p (ti); tsi_next (&ti)) | |
2839 | { | |
f47c96aa | 2840 | tree new_stmt = tsi_stmt (ti); |
b28b1600 | 2841 | find_new_referenced_vars (tsi_stmt_ptr (ti)); |
f47c96aa | 2842 | bsi_insert_before (si_p, new_stmt, BSI_NEW_STMT); |
cfaab3a9 | 2843 | mark_symbols_for_renaming (new_stmt); |
f47c96aa | 2844 | bsi_next (si_p); |
b28b1600 JJ |
2845 | } |
2846 | ||
b28b1600 JJ |
2847 | return tmp; |
2848 | } | |
2849 | ||
2850 | ||
6de9cd9a DN |
2851 | /* A simple pass that attempts to fold all builtin functions. This pass |
2852 | is run after we've propagated as many constants as we can. */ | |
2853 | ||
c2924966 | 2854 | static unsigned int |
6de9cd9a DN |
2855 | execute_fold_all_builtins (void) |
2856 | { | |
a7d6ba24 | 2857 | bool cfg_changed = false; |
6de9cd9a | 2858 | basic_block bb; |
7b0e48fb DB |
2859 | unsigned int todoflags = 0; |
2860 | ||
6de9cd9a DN |
2861 | FOR_EACH_BB (bb) |
2862 | { | |
2863 | block_stmt_iterator i; | |
10a0d495 | 2864 | for (i = bsi_start (bb); !bsi_end_p (i); ) |
6de9cd9a DN |
2865 | { |
2866 | tree *stmtp = bsi_stmt_ptr (i); | |
af47810a | 2867 | tree old_stmt = *stmtp; |
6de9cd9a DN |
2868 | tree call = get_rhs (*stmtp); |
2869 | tree callee, result; | |
10a0d495 | 2870 | enum built_in_function fcode; |
6de9cd9a DN |
2871 | |
2872 | if (!call || TREE_CODE (call) != CALL_EXPR) | |
10a0d495 JJ |
2873 | { |
2874 | bsi_next (&i); | |
2875 | continue; | |
2876 | } | |
6de9cd9a DN |
2877 | callee = get_callee_fndecl (call); |
2878 | if (!callee || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL) | |
10a0d495 JJ |
2879 | { |
2880 | bsi_next (&i); | |
2881 | continue; | |
2882 | } | |
2883 | fcode = DECL_FUNCTION_CODE (callee); | |
6de9cd9a DN |
2884 | |
2885 | result = ccp_fold_builtin (*stmtp, call); | |
2886 | if (!result) | |
2887 | switch (DECL_FUNCTION_CODE (callee)) | |
2888 | { | |
2889 | case BUILT_IN_CONSTANT_P: | |
2890 | /* Resolve __builtin_constant_p. If it hasn't been | |
2891 | folded to integer_one_node by now, it's fairly | |
2892 | certain that the value simply isn't constant. */ | |
2893 | result = integer_zero_node; | |
2894 | break; | |
2895 | ||
cb8e078d JJ |
2896 | case BUILT_IN_STACK_RESTORE: |
2897 | result = optimize_stack_restore (bb, *stmtp, i); | |
d7bd8aeb JJ |
2898 | if (result) |
2899 | break; | |
2900 | bsi_next (&i); | |
2901 | continue; | |
2902 | ||
2903 | case BUILT_IN_VA_START: | |
2904 | case BUILT_IN_VA_END: | |
2905 | case BUILT_IN_VA_COPY: | |
2906 | /* These shouldn't be folded before pass_stdarg. */ | |
2907 | result = optimize_stdarg_builtin (*stmtp); | |
cb8e078d JJ |
2908 | if (result) |
2909 | break; | |
2910 | /* FALLTHRU */ | |
2911 | ||
6de9cd9a | 2912 | default: |
10a0d495 | 2913 | bsi_next (&i); |
6de9cd9a DN |
2914 | continue; |
2915 | } | |
2916 | ||
2917 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2918 | { | |
2919 | fprintf (dump_file, "Simplified\n "); | |
2920 | print_generic_stmt (dump_file, *stmtp, dump_flags); | |
2921 | } | |
2922 | ||
cfaab3a9 DN |
2923 | push_stmt_changes (stmtp); |
2924 | ||
b28b1600 JJ |
2925 | if (!set_rhs (stmtp, result)) |
2926 | { | |
2e929cf3 JH |
2927 | result = convert_to_gimple_builtin (&i, result, |
2928 | TREE_CODE (old_stmt) | |
07beea0d | 2929 | != GIMPLE_MODIFY_STMT); |
e16acfcd NS |
2930 | if (result) |
2931 | { | |
2932 | bool ok = set_rhs (stmtp, result); | |
e16acfcd | 2933 | gcc_assert (ok); |
7b0e48fb | 2934 | todoflags |= TODO_rebuild_alias; |
e16acfcd | 2935 | } |
b28b1600 | 2936 | } |
cfaab3a9 DN |
2937 | |
2938 | pop_stmt_changes (stmtp); | |
2939 | ||
af47810a | 2940 | if (maybe_clean_or_replace_eh_stmt (old_stmt, *stmtp) |
a7d6ba24 JJ |
2941 | && tree_purge_dead_eh_edges (bb)) |
2942 | cfg_changed = true; | |
6de9cd9a DN |
2943 | |
2944 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2945 | { | |
2946 | fprintf (dump_file, "to\n "); | |
2947 | print_generic_stmt (dump_file, *stmtp, dump_flags); | |
2948 | fprintf (dump_file, "\n"); | |
2949 | } | |
10a0d495 JJ |
2950 | |
2951 | /* Retry the same statement if it changed into another | |
2952 | builtin, there might be new opportunities now. */ | |
2953 | call = get_rhs (*stmtp); | |
2954 | if (!call || TREE_CODE (call) != CALL_EXPR) | |
2955 | { | |
2956 | bsi_next (&i); | |
2957 | continue; | |
2958 | } | |
2959 | callee = get_callee_fndecl (call); | |
2960 | if (!callee | |
2961 | || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL | |
2962 | || DECL_FUNCTION_CODE (callee) == fcode) | |
2963 | bsi_next (&i); | |
6de9cd9a DN |
2964 | } |
2965 | } | |
7b0e48fb | 2966 | |
a7d6ba24 | 2967 | /* Delete unreachable blocks. */ |
7b0e48fb DB |
2968 | if (cfg_changed) |
2969 | todoflags |= TODO_cleanup_cfg; | |
2970 | ||
2971 | return todoflags; | |
6de9cd9a DN |
2972 | } |
2973 | ||
750628d8 | 2974 | |
6de9cd9a DN |
2975 | struct tree_opt_pass pass_fold_builtins = |
2976 | { | |
2977 | "fab", /* name */ | |
2978 | NULL, /* gate */ | |
2979 | execute_fold_all_builtins, /* execute */ | |
2980 | NULL, /* sub */ | |
2981 | NULL, /* next */ | |
2982 | 0, /* static_pass_number */ | |
2983 | 0, /* tv_id */ | |
7faade0f | 2984 | PROP_cfg | PROP_ssa, /* properties_required */ |
6de9cd9a DN |
2985 | 0, /* properties_provided */ |
2986 | 0, /* properties_destroyed */ | |
2987 | 0, /* todo_flags_start */ | |
b28b1600 JJ |
2988 | TODO_dump_func |
2989 | | TODO_verify_ssa | |
0bca51f0 | 2990 | | TODO_update_ssa, /* todo_flags_finish */ |
9f8628ba | 2991 | 0 /* letter */ |
6de9cd9a | 2992 | }; |