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4ee9c684 | 1 | /* Conditional constant propagation pass for the GNU compiler. |
cfaf579d | 2 | Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 |
000657b5 | 3 | Free Software Foundation, Inc. |
4ee9c684 | 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 | |
8c4c00c1 | 11 | Free Software Foundation; either version 3, or (at your option) any |
4ee9c684 | 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 | |
8c4c00c1 | 20 | along with GCC; see the file COPYING3. If not see |
21 | <http://www.gnu.org/licenses/>. */ | |
4ee9c684 | 22 | |
88dbf20f | 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 | ||
bfa30570 | 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. | |
88dbf20f | 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 | |
4fb5e5ca | 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, | |
88dbf20f | 138 | |
4fb5e5ca | 139 | # a_5 = VDEF <a_4> |
88dbf20f | 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 | ||
bfa30570 | 149 | Note that the initial value of virtual operands is VARYING, not |
150 | UNDEFINED. Consider, for instance global variables: | |
88dbf20f | 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 | |
bfa30570 | 168 | would erroneously optimize the above into 'return 3;'. |
88dbf20f | 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. | |
4ee9c684 | 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" | |
4ee9c684 | 192 | #include "tree.h" |
41511585 | 193 | #include "flags.h" |
4ee9c684 | 194 | #include "rtl.h" |
195 | #include "tm_p.h" | |
41511585 | 196 | #include "ggc.h" |
4ee9c684 | 197 | #include "basic-block.h" |
41511585 | 198 | #include "output.h" |
41511585 | 199 | #include "expr.h" |
200 | #include "function.h" | |
4ee9c684 | 201 | #include "diagnostic.h" |
41511585 | 202 | #include "timevar.h" |
4ee9c684 | 203 | #include "tree-dump.h" |
41511585 | 204 | #include "tree-flow.h" |
4ee9c684 | 205 | #include "tree-pass.h" |
41511585 | 206 | #include "tree-ssa-propagate.h" |
5a4b7e1e | 207 | #include "value-prof.h" |
41511585 | 208 | #include "langhooks.h" |
8782adcf | 209 | #include "target.h" |
add6ee5e | 210 | #include "toplev.h" |
43fb76c1 | 211 | #include "dbgcnt.h" |
4ee9c684 | 212 | |
213 | ||
214 | /* Possible lattice values. */ | |
215 | typedef enum | |
216 | { | |
bfa30570 | 217 | UNINITIALIZED, |
4ee9c684 | 218 | UNDEFINED, |
219 | CONSTANT, | |
220 | VARYING | |
88dbf20f | 221 | } ccp_lattice_t; |
4ee9c684 | 222 | |
88dbf20f | 223 | /* Array of propagated constant values. After propagation, |
224 | CONST_VAL[I].VALUE holds the constant value for SSA_NAME(I). If | |
225 | the constant is held in an SSA name representing a memory store | |
4fb5e5ca | 226 | (i.e., a VDEF), CONST_VAL[I].MEM_REF will contain the actual |
227 | memory reference used to store (i.e., the LHS of the assignment | |
228 | doing the store). */ | |
20140406 | 229 | static prop_value_t *const_val; |
4ee9c684 | 230 | |
4af351a8 | 231 | static void canonicalize_float_value (prop_value_t *); |
6688f8ec | 232 | static bool ccp_fold_stmt (gimple_stmt_iterator *); |
4af351a8 | 233 | |
88dbf20f | 234 | /* Dump constant propagation value VAL to file OUTF prefixed by PREFIX. */ |
01406fc0 | 235 | |
236 | static void | |
88dbf20f | 237 | dump_lattice_value (FILE *outf, const char *prefix, prop_value_t val) |
01406fc0 | 238 | { |
41511585 | 239 | switch (val.lattice_val) |
01406fc0 | 240 | { |
88dbf20f | 241 | case UNINITIALIZED: |
242 | fprintf (outf, "%sUNINITIALIZED", prefix); | |
243 | break; | |
41511585 | 244 | case UNDEFINED: |
245 | fprintf (outf, "%sUNDEFINED", prefix); | |
246 | break; | |
247 | case VARYING: | |
248 | fprintf (outf, "%sVARYING", prefix); | |
249 | break; | |
41511585 | 250 | case CONSTANT: |
251 | fprintf (outf, "%sCONSTANT ", prefix); | |
88dbf20f | 252 | print_generic_expr (outf, val.value, dump_flags); |
41511585 | 253 | break; |
254 | default: | |
8c0963c4 | 255 | gcc_unreachable (); |
41511585 | 256 | } |
01406fc0 | 257 | } |
4ee9c684 | 258 | |
4ee9c684 | 259 | |
88dbf20f | 260 | /* Print lattice value VAL to stderr. */ |
261 | ||
262 | void debug_lattice_value (prop_value_t val); | |
263 | ||
264 | void | |
265 | debug_lattice_value (prop_value_t val) | |
266 | { | |
267 | dump_lattice_value (stderr, "", val); | |
268 | fprintf (stderr, "\n"); | |
269 | } | |
4ee9c684 | 270 | |
4ee9c684 | 271 | |
75a70cf9 | 272 | |
aecfc21d | 273 | /* If SYM is a constant variable with known value, return the value. |
274 | NULL_TREE is returned otherwise. */ | |
275 | ||
e004838d | 276 | tree |
aecfc21d | 277 | get_symbol_constant_value (tree sym) |
278 | { | |
279 | if (TREE_STATIC (sym) | |
cc8f0042 | 280 | && (TREE_READONLY (sym) |
281 | || TREE_CODE (sym) == CONST_DECL)) | |
aecfc21d | 282 | { |
283 | tree val = DECL_INITIAL (sym); | |
590d65aa | 284 | if (val) |
285 | { | |
286 | STRIP_USELESS_TYPE_CONVERSION (val); | |
287 | if (is_gimple_min_invariant (val)) | |
3a44a278 | 288 | { |
289 | if (TREE_CODE (val) == ADDR_EXPR) | |
290 | { | |
291 | tree base = get_base_address (TREE_OPERAND (val, 0)); | |
292 | if (base && TREE_CODE (base) == VAR_DECL) | |
cc8f0042 | 293 | { |
294 | TREE_ADDRESSABLE (base) = 1; | |
295 | if (gimple_referenced_vars (cfun)) | |
296 | add_referenced_var (base); | |
297 | } | |
3a44a278 | 298 | } |
299 | return val; | |
300 | } | |
590d65aa | 301 | } |
6e6e51e5 | 302 | /* Variables declared 'const' without an initializer |
f0b5f617 | 303 | have zero as the initializer if they may not be |
e004838d | 304 | overridden at link or run time. */ |
6e6e51e5 | 305 | if (!val |
807bf718 | 306 | && !DECL_EXTERNAL (sym) |
e004838d | 307 | && targetm.binds_local_p (sym) |
6e6e51e5 | 308 | && (INTEGRAL_TYPE_P (TREE_TYPE (sym)) |
309 | || SCALAR_FLOAT_TYPE_P (TREE_TYPE (sym)))) | |
807bf718 | 310 | return fold_convert (TREE_TYPE (sym), integer_zero_node); |
aecfc21d | 311 | } |
312 | ||
313 | return NULL_TREE; | |
314 | } | |
d03bd588 | 315 | |
88dbf20f | 316 | /* Compute a default value for variable VAR and store it in the |
317 | CONST_VAL array. The following rules are used to get default | |
318 | values: | |
01406fc0 | 319 | |
88dbf20f | 320 | 1- Global and static variables that are declared constant are |
321 | considered CONSTANT. | |
322 | ||
323 | 2- Any other value is considered UNDEFINED. This is useful when | |
41511585 | 324 | considering PHI nodes. PHI arguments that are undefined do not |
325 | change the constant value of the PHI node, which allows for more | |
88dbf20f | 326 | constants to be propagated. |
4ee9c684 | 327 | |
8883e700 | 328 | 3- Variables defined by statements other than assignments and PHI |
88dbf20f | 329 | nodes are considered VARYING. |
4ee9c684 | 330 | |
8883e700 | 331 | 4- Initial values of variables that are not GIMPLE registers are |
bfa30570 | 332 | considered VARYING. */ |
4ee9c684 | 333 | |
88dbf20f | 334 | static prop_value_t |
335 | get_default_value (tree var) | |
336 | { | |
337 | tree sym = SSA_NAME_VAR (var); | |
61207d43 | 338 | prop_value_t val = { UNINITIALIZED, NULL_TREE }; |
8edeb88b | 339 | gimple stmt; |
340 | ||
341 | stmt = SSA_NAME_DEF_STMT (var); | |
342 | ||
343 | if (gimple_nop_p (stmt)) | |
4ee9c684 | 344 | { |
8edeb88b | 345 | /* Variables defined by an empty statement are those used |
346 | before being initialized. If VAR is a local variable, we | |
347 | can assume initially that it is UNDEFINED, otherwise we must | |
348 | consider it VARYING. */ | |
349 | if (is_gimple_reg (sym) && TREE_CODE (sym) != PARM_DECL) | |
350 | val.lattice_val = UNDEFINED; | |
351 | else | |
352 | val.lattice_val = VARYING; | |
4ee9c684 | 353 | } |
8edeb88b | 354 | else if (is_gimple_assign (stmt) |
355 | /* Value-returning GIMPLE_CALL statements assign to | |
356 | a variable, and are treated similarly to GIMPLE_ASSIGN. */ | |
357 | || (is_gimple_call (stmt) | |
358 | && gimple_call_lhs (stmt) != NULL_TREE) | |
359 | || gimple_code (stmt) == GIMPLE_PHI) | |
41511585 | 360 | { |
8edeb88b | 361 | tree cst; |
362 | if (gimple_assign_single_p (stmt) | |
363 | && DECL_P (gimple_assign_rhs1 (stmt)) | |
364 | && (cst = get_symbol_constant_value (gimple_assign_rhs1 (stmt)))) | |
88dbf20f | 365 | { |
8edeb88b | 366 | val.lattice_val = CONSTANT; |
367 | val.value = cst; | |
88dbf20f | 368 | } |
369 | else | |
8edeb88b | 370 | /* Any other variable defined by an assignment or a PHI node |
371 | is considered UNDEFINED. */ | |
372 | val.lattice_val = UNDEFINED; | |
373 | } | |
374 | else | |
375 | { | |
376 | /* Otherwise, VAR will never take on a constant value. */ | |
377 | val.lattice_val = VARYING; | |
41511585 | 378 | } |
4ee9c684 | 379 | |
41511585 | 380 | return val; |
381 | } | |
4ee9c684 | 382 | |
4ee9c684 | 383 | |
bfa30570 | 384 | /* Get the constant value associated with variable VAR. */ |
4ee9c684 | 385 | |
bfa30570 | 386 | static inline prop_value_t * |
387 | get_value (tree var) | |
88dbf20f | 388 | { |
e004838d | 389 | prop_value_t *val; |
bfa30570 | 390 | |
e004838d | 391 | if (const_val == NULL) |
392 | return NULL; | |
393 | ||
394 | val = &const_val[SSA_NAME_VERSION (var)]; | |
bfa30570 | 395 | if (val->lattice_val == UNINITIALIZED) |
4ee9c684 | 396 | *val = get_default_value (var); |
397 | ||
4af351a8 | 398 | canonicalize_float_value (val); |
399 | ||
4ee9c684 | 400 | return val; |
401 | } | |
402 | ||
bfa30570 | 403 | /* Sets the value associated with VAR to VARYING. */ |
404 | ||
405 | static inline void | |
406 | set_value_varying (tree var) | |
407 | { | |
408 | prop_value_t *val = &const_val[SSA_NAME_VERSION (var)]; | |
409 | ||
410 | val->lattice_val = VARYING; | |
411 | val->value = NULL_TREE; | |
bfa30570 | 412 | } |
4ee9c684 | 413 | |
b31eb493 | 414 | /* For float types, modify the value of VAL to make ccp work correctly |
415 | for non-standard values (-0, NaN): | |
416 | ||
417 | If HONOR_SIGNED_ZEROS is false, and VAL = -0, we canonicalize it to 0. | |
418 | If HONOR_NANS is false, and VAL is NaN, we canonicalize it to UNDEFINED. | |
419 | This is to fix the following problem (see PR 29921): Suppose we have | |
420 | ||
421 | x = 0.0 * y | |
422 | ||
423 | and we set value of y to NaN. This causes value of x to be set to NaN. | |
424 | When we later determine that y is in fact VARYING, fold uses the fact | |
425 | that HONOR_NANS is false, and we try to change the value of x to 0, | |
426 | causing an ICE. With HONOR_NANS being false, the real appearance of | |
427 | NaN would cause undefined behavior, though, so claiming that y (and x) | |
428 | are UNDEFINED initially is correct. */ | |
429 | ||
430 | static void | |
431 | canonicalize_float_value (prop_value_t *val) | |
432 | { | |
433 | enum machine_mode mode; | |
434 | tree type; | |
435 | REAL_VALUE_TYPE d; | |
436 | ||
437 | if (val->lattice_val != CONSTANT | |
438 | || TREE_CODE (val->value) != REAL_CST) | |
439 | return; | |
440 | ||
441 | d = TREE_REAL_CST (val->value); | |
442 | type = TREE_TYPE (val->value); | |
443 | mode = TYPE_MODE (type); | |
444 | ||
445 | if (!HONOR_SIGNED_ZEROS (mode) | |
446 | && REAL_VALUE_MINUS_ZERO (d)) | |
447 | { | |
448 | val->value = build_real (type, dconst0); | |
449 | return; | |
450 | } | |
451 | ||
452 | if (!HONOR_NANS (mode) | |
453 | && REAL_VALUE_ISNAN (d)) | |
454 | { | |
455 | val->lattice_val = UNDEFINED; | |
456 | val->value = NULL; | |
b31eb493 | 457 | return; |
458 | } | |
459 | } | |
460 | ||
88dbf20f | 461 | /* Set the value for variable VAR to NEW_VAL. Return true if the new |
462 | value is different from VAR's previous value. */ | |
4ee9c684 | 463 | |
41511585 | 464 | static bool |
88dbf20f | 465 | set_lattice_value (tree var, prop_value_t new_val) |
4ee9c684 | 466 | { |
bfa30570 | 467 | prop_value_t *old_val = get_value (var); |
88dbf20f | 468 | |
b31eb493 | 469 | canonicalize_float_value (&new_val); |
470 | ||
88dbf20f | 471 | /* Lattice transitions must always be monotonically increasing in |
bfa30570 | 472 | value. If *OLD_VAL and NEW_VAL are the same, return false to |
473 | inform the caller that this was a non-transition. */ | |
474 | ||
aecfc21d | 475 | gcc_assert (old_val->lattice_val < new_val.lattice_val |
88dbf20f | 476 | || (old_val->lattice_val == new_val.lattice_val |
aecfc21d | 477 | && ((!old_val->value && !new_val.value) |
61207d43 | 478 | || operand_equal_p (old_val->value, new_val.value, 0)))); |
88dbf20f | 479 | |
480 | if (old_val->lattice_val != new_val.lattice_val) | |
4ee9c684 | 481 | { |
41511585 | 482 | if (dump_file && (dump_flags & TDF_DETAILS)) |
483 | { | |
88dbf20f | 484 | dump_lattice_value (dump_file, "Lattice value changed to ", new_val); |
bfa30570 | 485 | fprintf (dump_file, ". Adding SSA edges to worklist.\n"); |
41511585 | 486 | } |
487 | ||
88dbf20f | 488 | *old_val = new_val; |
489 | ||
bfa30570 | 490 | gcc_assert (new_val.lattice_val != UNDEFINED); |
491 | return true; | |
4ee9c684 | 492 | } |
41511585 | 493 | |
494 | return false; | |
4ee9c684 | 495 | } |
496 | ||
497 | ||
88dbf20f | 498 | /* Return the likely CCP lattice value for STMT. |
4ee9c684 | 499 | |
41511585 | 500 | If STMT has no operands, then return CONSTANT. |
4ee9c684 | 501 | |
d61b9af3 | 502 | Else if undefinedness of operands of STMT cause its value to be |
503 | undefined, then return UNDEFINED. | |
4ee9c684 | 504 | |
41511585 | 505 | Else if any operands of STMT are constants, then return CONSTANT. |
4ee9c684 | 506 | |
41511585 | 507 | Else return VARYING. */ |
4ee9c684 | 508 | |
88dbf20f | 509 | static ccp_lattice_t |
75a70cf9 | 510 | likely_value (gimple stmt) |
41511585 | 511 | { |
d61b9af3 | 512 | bool has_constant_operand, has_undefined_operand, all_undefined_operands; |
41511585 | 513 | tree use; |
514 | ssa_op_iter iter; | |
8edeb88b | 515 | unsigned i; |
4ee9c684 | 516 | |
590c3166 | 517 | enum gimple_code code = gimple_code (stmt); |
75a70cf9 | 518 | |
519 | /* This function appears to be called only for assignments, calls, | |
520 | conditionals, and switches, due to the logic in visit_stmt. */ | |
521 | gcc_assert (code == GIMPLE_ASSIGN | |
522 | || code == GIMPLE_CALL | |
523 | || code == GIMPLE_COND | |
524 | || code == GIMPLE_SWITCH); | |
88dbf20f | 525 | |
526 | /* If the statement has volatile operands, it won't fold to a | |
527 | constant value. */ | |
75a70cf9 | 528 | if (gimple_has_volatile_ops (stmt)) |
88dbf20f | 529 | return VARYING; |
530 | ||
75a70cf9 | 531 | /* Arrive here for more complex cases. */ |
bfa30570 | 532 | has_constant_operand = false; |
d61b9af3 | 533 | has_undefined_operand = false; |
534 | all_undefined_operands = true; | |
8edeb88b | 535 | FOR_EACH_SSA_TREE_OPERAND (use, stmt, iter, SSA_OP_USE) |
41511585 | 536 | { |
bfa30570 | 537 | prop_value_t *val = get_value (use); |
41511585 | 538 | |
bfa30570 | 539 | if (val->lattice_val == UNDEFINED) |
d61b9af3 | 540 | has_undefined_operand = true; |
541 | else | |
542 | all_undefined_operands = false; | |
88dbf20f | 543 | |
41511585 | 544 | if (val->lattice_val == CONSTANT) |
bfa30570 | 545 | has_constant_operand = true; |
4ee9c684 | 546 | } |
41511585 | 547 | |
dd277d48 | 548 | /* There may be constants in regular rhs operands. For calls we |
549 | have to ignore lhs, fndecl and static chain, otherwise only | |
550 | the lhs. */ | |
551 | for (i = (is_gimple_call (stmt) ? 2 : 0) + gimple_has_lhs (stmt); | |
8edeb88b | 552 | i < gimple_num_ops (stmt); ++i) |
553 | { | |
554 | tree op = gimple_op (stmt, i); | |
555 | if (!op || TREE_CODE (op) == SSA_NAME) | |
556 | continue; | |
557 | if (is_gimple_min_invariant (op)) | |
558 | has_constant_operand = true; | |
559 | } | |
560 | ||
d61b9af3 | 561 | /* If the operation combines operands like COMPLEX_EXPR make sure to |
562 | not mark the result UNDEFINED if only one part of the result is | |
563 | undefined. */ | |
75a70cf9 | 564 | if (has_undefined_operand && all_undefined_operands) |
d61b9af3 | 565 | return UNDEFINED; |
75a70cf9 | 566 | else if (code == GIMPLE_ASSIGN && has_undefined_operand) |
d61b9af3 | 567 | { |
75a70cf9 | 568 | switch (gimple_assign_rhs_code (stmt)) |
d61b9af3 | 569 | { |
570 | /* Unary operators are handled with all_undefined_operands. */ | |
571 | case PLUS_EXPR: | |
572 | case MINUS_EXPR: | |
d61b9af3 | 573 | case POINTER_PLUS_EXPR: |
d61b9af3 | 574 | /* Not MIN_EXPR, MAX_EXPR. One VARYING operand may be selected. |
575 | Not bitwise operators, one VARYING operand may specify the | |
576 | result completely. Not logical operators for the same reason. | |
05a936a0 | 577 | Not COMPLEX_EXPR as one VARYING operand makes the result partly |
578 | not UNDEFINED. Not *DIV_EXPR, comparisons and shifts because | |
579 | the undefined operand may be promoted. */ | |
d61b9af3 | 580 | return UNDEFINED; |
581 | ||
582 | default: | |
583 | ; | |
584 | } | |
585 | } | |
586 | /* If there was an UNDEFINED operand but the result may be not UNDEFINED | |
587 | fall back to VARYING even if there were CONSTANT operands. */ | |
588 | if (has_undefined_operand) | |
589 | return VARYING; | |
590 | ||
8edeb88b | 591 | /* We do not consider virtual operands here -- load from read-only |
592 | memory may have only VARYING virtual operands, but still be | |
593 | constant. */ | |
bfa30570 | 594 | if (has_constant_operand |
8edeb88b | 595 | || gimple_references_memory_p (stmt)) |
88dbf20f | 596 | return CONSTANT; |
597 | ||
bfa30570 | 598 | return VARYING; |
4ee9c684 | 599 | } |
600 | ||
bfa30570 | 601 | /* Returns true if STMT cannot be constant. */ |
602 | ||
603 | static bool | |
75a70cf9 | 604 | surely_varying_stmt_p (gimple stmt) |
bfa30570 | 605 | { |
606 | /* If the statement has operands that we cannot handle, it cannot be | |
607 | constant. */ | |
75a70cf9 | 608 | if (gimple_has_volatile_ops (stmt)) |
bfa30570 | 609 | return true; |
610 | ||
f257af64 | 611 | /* If it is a call and does not return a value or is not a |
612 | builtin and not an indirect call, it is varying. */ | |
75a70cf9 | 613 | if (is_gimple_call (stmt)) |
f257af64 | 614 | { |
615 | tree fndecl; | |
616 | if (!gimple_call_lhs (stmt) | |
617 | || ((fndecl = gimple_call_fndecl (stmt)) != NULL_TREE | |
5768aeb3 | 618 | && !DECL_BUILT_IN (fndecl))) |
f257af64 | 619 | return true; |
620 | } | |
bfa30570 | 621 | |
8edeb88b | 622 | /* Any other store operation is not interesting. */ |
dd277d48 | 623 | else if (gimple_vdef (stmt)) |
8edeb88b | 624 | return true; |
625 | ||
bfa30570 | 626 | /* Anything other than assignments and conditional jumps are not |
627 | interesting for CCP. */ | |
75a70cf9 | 628 | if (gimple_code (stmt) != GIMPLE_ASSIGN |
f257af64 | 629 | && gimple_code (stmt) != GIMPLE_COND |
630 | && gimple_code (stmt) != GIMPLE_SWITCH | |
631 | && gimple_code (stmt) != GIMPLE_CALL) | |
bfa30570 | 632 | return true; |
633 | ||
634 | return false; | |
635 | } | |
4ee9c684 | 636 | |
41511585 | 637 | /* Initialize local data structures for CCP. */ |
4ee9c684 | 638 | |
639 | static void | |
41511585 | 640 | ccp_initialize (void) |
4ee9c684 | 641 | { |
41511585 | 642 | basic_block bb; |
4ee9c684 | 643 | |
43959b95 | 644 | const_val = XCNEWVEC (prop_value_t, num_ssa_names); |
4ee9c684 | 645 | |
41511585 | 646 | /* Initialize simulation flags for PHI nodes and statements. */ |
647 | FOR_EACH_BB (bb) | |
4ee9c684 | 648 | { |
75a70cf9 | 649 | gimple_stmt_iterator i; |
4ee9c684 | 650 | |
75a70cf9 | 651 | for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i)) |
41511585 | 652 | { |
75a70cf9 | 653 | gimple stmt = gsi_stmt (i); |
2193544e | 654 | bool is_varying; |
655 | ||
656 | /* If the statement is a control insn, then we do not | |
657 | want to avoid simulating the statement once. Failure | |
658 | to do so means that those edges will never get added. */ | |
659 | if (stmt_ends_bb_p (stmt)) | |
660 | is_varying = false; | |
661 | else | |
662 | is_varying = surely_varying_stmt_p (stmt); | |
4ee9c684 | 663 | |
bfa30570 | 664 | if (is_varying) |
41511585 | 665 | { |
88dbf20f | 666 | tree def; |
667 | ssa_op_iter iter; | |
668 | ||
669 | /* If the statement will not produce a constant, mark | |
670 | all its outputs VARYING. */ | |
671 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS) | |
8edeb88b | 672 | set_value_varying (def); |
41511585 | 673 | } |
75a70cf9 | 674 | prop_set_simulate_again (stmt, !is_varying); |
41511585 | 675 | } |
4ee9c684 | 676 | } |
677 | ||
75a70cf9 | 678 | /* Now process PHI nodes. We never clear the simulate_again flag on |
679 | phi nodes, since we do not know which edges are executable yet, | |
680 | except for phi nodes for virtual operands when we do not do store ccp. */ | |
41511585 | 681 | FOR_EACH_BB (bb) |
4ee9c684 | 682 | { |
75a70cf9 | 683 | gimple_stmt_iterator i; |
41511585 | 684 | |
75a70cf9 | 685 | for (i = gsi_start_phis (bb); !gsi_end_p (i); gsi_next (&i)) |
686 | { | |
687 | gimple phi = gsi_stmt (i); | |
688 | ||
61207d43 | 689 | if (!is_gimple_reg (gimple_phi_result (phi))) |
75a70cf9 | 690 | prop_set_simulate_again (phi, false); |
bfa30570 | 691 | else |
75a70cf9 | 692 | prop_set_simulate_again (phi, true); |
41511585 | 693 | } |
4ee9c684 | 694 | } |
41511585 | 695 | } |
4ee9c684 | 696 | |
43fb76c1 | 697 | /* Debug count support. Reset the values of ssa names |
698 | VARYING when the total number ssa names analyzed is | |
699 | beyond the debug count specified. */ | |
700 | ||
701 | static void | |
702 | do_dbg_cnt (void) | |
703 | { | |
704 | unsigned i; | |
705 | for (i = 0; i < num_ssa_names; i++) | |
706 | { | |
707 | if (!dbg_cnt (ccp)) | |
708 | { | |
709 | const_val[i].lattice_val = VARYING; | |
710 | const_val[i].value = NULL_TREE; | |
711 | } | |
712 | } | |
713 | } | |
714 | ||
4ee9c684 | 715 | |
88dbf20f | 716 | /* Do final substitution of propagated values, cleanup the flowgraph and |
33a34f1e | 717 | free allocated storage. |
4ee9c684 | 718 | |
33a34f1e | 719 | Return TRUE when something was optimized. */ |
720 | ||
721 | static bool | |
88dbf20f | 722 | ccp_finalize (void) |
4ee9c684 | 723 | { |
43fb76c1 | 724 | bool something_changed; |
725 | ||
726 | do_dbg_cnt (); | |
88dbf20f | 727 | /* Perform substitutions based on the known constant values. */ |
6688f8ec | 728 | something_changed = substitute_and_fold (const_val, ccp_fold_stmt); |
4ee9c684 | 729 | |
88dbf20f | 730 | free (const_val); |
e004838d | 731 | const_val = NULL; |
33a34f1e | 732 | return something_changed;; |
4ee9c684 | 733 | } |
734 | ||
735 | ||
88dbf20f | 736 | /* Compute the meet operator between *VAL1 and *VAL2. Store the result |
737 | in VAL1. | |
738 | ||
739 | any M UNDEFINED = any | |
88dbf20f | 740 | any M VARYING = VARYING |
741 | Ci M Cj = Ci if (i == j) | |
742 | Ci M Cj = VARYING if (i != j) | |
bfa30570 | 743 | */ |
4ee9c684 | 744 | |
745 | static void | |
88dbf20f | 746 | ccp_lattice_meet (prop_value_t *val1, prop_value_t *val2) |
4ee9c684 | 747 | { |
88dbf20f | 748 | if (val1->lattice_val == UNDEFINED) |
4ee9c684 | 749 | { |
88dbf20f | 750 | /* UNDEFINED M any = any */ |
751 | *val1 = *val2; | |
41511585 | 752 | } |
88dbf20f | 753 | else if (val2->lattice_val == UNDEFINED) |
92481a4d | 754 | { |
88dbf20f | 755 | /* any M UNDEFINED = any |
756 | Nothing to do. VAL1 already contains the value we want. */ | |
757 | ; | |
92481a4d | 758 | } |
88dbf20f | 759 | else if (val1->lattice_val == VARYING |
760 | || val2->lattice_val == VARYING) | |
41511585 | 761 | { |
88dbf20f | 762 | /* any M VARYING = VARYING. */ |
763 | val1->lattice_val = VARYING; | |
764 | val1->value = NULL_TREE; | |
41511585 | 765 | } |
88dbf20f | 766 | else if (val1->lattice_val == CONSTANT |
767 | && val2->lattice_val == CONSTANT | |
61207d43 | 768 | && simple_cst_equal (val1->value, val2->value) == 1) |
41511585 | 769 | { |
88dbf20f | 770 | /* Ci M Cj = Ci if (i == j) |
771 | Ci M Cj = VARYING if (i != j) | |
772 | ||
773 | If these two values come from memory stores, make sure that | |
774 | they come from the same memory reference. */ | |
775 | val1->lattice_val = CONSTANT; | |
776 | val1->value = val1->value; | |
41511585 | 777 | } |
778 | else | |
779 | { | |
88dbf20f | 780 | /* Any other combination is VARYING. */ |
781 | val1->lattice_val = VARYING; | |
782 | val1->value = NULL_TREE; | |
41511585 | 783 | } |
4ee9c684 | 784 | } |
785 | ||
786 | ||
41511585 | 787 | /* Loop through the PHI_NODE's parameters for BLOCK and compare their |
788 | lattice values to determine PHI_NODE's lattice value. The value of a | |
88dbf20f | 789 | PHI node is determined calling ccp_lattice_meet with all the arguments |
41511585 | 790 | of the PHI node that are incoming via executable edges. */ |
4ee9c684 | 791 | |
41511585 | 792 | static enum ssa_prop_result |
75a70cf9 | 793 | ccp_visit_phi_node (gimple phi) |
4ee9c684 | 794 | { |
75a70cf9 | 795 | unsigned i; |
88dbf20f | 796 | prop_value_t *old_val, new_val; |
4ee9c684 | 797 | |
41511585 | 798 | if (dump_file && (dump_flags & TDF_DETAILS)) |
4ee9c684 | 799 | { |
41511585 | 800 | fprintf (dump_file, "\nVisiting PHI node: "); |
75a70cf9 | 801 | print_gimple_stmt (dump_file, phi, 0, dump_flags); |
4ee9c684 | 802 | } |
4ee9c684 | 803 | |
75a70cf9 | 804 | old_val = get_value (gimple_phi_result (phi)); |
41511585 | 805 | switch (old_val->lattice_val) |
806 | { | |
807 | case VARYING: | |
88dbf20f | 808 | return SSA_PROP_VARYING; |
4ee9c684 | 809 | |
41511585 | 810 | case CONSTANT: |
811 | new_val = *old_val; | |
812 | break; | |
4ee9c684 | 813 | |
41511585 | 814 | case UNDEFINED: |
41511585 | 815 | new_val.lattice_val = UNDEFINED; |
88dbf20f | 816 | new_val.value = NULL_TREE; |
41511585 | 817 | break; |
4ee9c684 | 818 | |
41511585 | 819 | default: |
8c0963c4 | 820 | gcc_unreachable (); |
41511585 | 821 | } |
4ee9c684 | 822 | |
75a70cf9 | 823 | for (i = 0; i < gimple_phi_num_args (phi); i++) |
41511585 | 824 | { |
88dbf20f | 825 | /* Compute the meet operator over all the PHI arguments flowing |
826 | through executable edges. */ | |
75a70cf9 | 827 | edge e = gimple_phi_arg_edge (phi, i); |
4ee9c684 | 828 | |
41511585 | 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 | { | |
75a70cf9 | 841 | tree arg = gimple_phi_arg (phi, i)->def; |
88dbf20f | 842 | prop_value_t arg_val; |
4ee9c684 | 843 | |
88dbf20f | 844 | if (is_gimple_min_invariant (arg)) |
41511585 | 845 | { |
88dbf20f | 846 | arg_val.lattice_val = CONSTANT; |
847 | arg_val.value = arg; | |
41511585 | 848 | } |
849 | else | |
bfa30570 | 850 | arg_val = *(get_value (arg)); |
4ee9c684 | 851 | |
88dbf20f | 852 | ccp_lattice_meet (&new_val, &arg_val); |
4ee9c684 | 853 | |
41511585 | 854 | if (dump_file && (dump_flags & TDF_DETAILS)) |
855 | { | |
856 | fprintf (dump_file, "\t"); | |
88dbf20f | 857 | print_generic_expr (dump_file, arg, dump_flags); |
858 | dump_lattice_value (dump_file, "\tValue: ", arg_val); | |
41511585 | 859 | fprintf (dump_file, "\n"); |
860 | } | |
4ee9c684 | 861 | |
41511585 | 862 | if (new_val.lattice_val == VARYING) |
863 | break; | |
864 | } | |
865 | } | |
4ee9c684 | 866 | |
867 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
41511585 | 868 | { |
869 | dump_lattice_value (dump_file, "\n PHI node value: ", new_val); | |
870 | fprintf (dump_file, "\n\n"); | |
871 | } | |
872 | ||
bfa30570 | 873 | /* Make the transition to the new value. */ |
75a70cf9 | 874 | if (set_lattice_value (gimple_phi_result (phi), new_val)) |
41511585 | 875 | { |
876 | if (new_val.lattice_val == VARYING) | |
877 | return SSA_PROP_VARYING; | |
878 | else | |
879 | return SSA_PROP_INTERESTING; | |
880 | } | |
881 | else | |
882 | return SSA_PROP_NOT_INTERESTING; | |
4ee9c684 | 883 | } |
884 | ||
fb8ed03f | 885 | /* Return true if we may propagate the address expression ADDR into the |
886 | dereference DEREF and cancel them. */ | |
887 | ||
888 | bool | |
889 | may_propagate_address_into_dereference (tree addr, tree deref) | |
890 | { | |
891 | gcc_assert (INDIRECT_REF_P (deref) | |
892 | && TREE_CODE (addr) == ADDR_EXPR); | |
893 | ||
0d051ece | 894 | /* Don't propagate if ADDR's operand has incomplete type. */ |
895 | if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_OPERAND (addr, 0)))) | |
896 | return false; | |
897 | ||
fb8ed03f | 898 | /* If the address is invariant then we do not need to preserve restrict |
899 | qualifications. But we do need to preserve volatile qualifiers until | |
900 | we can annotate the folded dereference itself properly. */ | |
901 | if (is_gimple_min_invariant (addr) | |
902 | && (!TREE_THIS_VOLATILE (deref) | |
903 | || TYPE_VOLATILE (TREE_TYPE (addr)))) | |
904 | return useless_type_conversion_p (TREE_TYPE (deref), | |
905 | TREE_TYPE (TREE_OPERAND (addr, 0))); | |
906 | ||
907 | /* Else both the address substitution and the folding must result in | |
908 | a valid useless type conversion sequence. */ | |
909 | return (useless_type_conversion_p (TREE_TYPE (TREE_OPERAND (deref, 0)), | |
910 | TREE_TYPE (addr)) | |
911 | && useless_type_conversion_p (TREE_TYPE (deref), | |
912 | TREE_TYPE (TREE_OPERAND (addr, 0)))); | |
913 | } | |
4ee9c684 | 914 | |
41511585 | 915 | /* CCP specific front-end to the non-destructive constant folding |
916 | routines. | |
4ee9c684 | 917 | |
918 | Attempt to simplify the RHS of STMT knowing that one or more | |
919 | operands are constants. | |
920 | ||
921 | If simplification is possible, return the simplified RHS, | |
75a70cf9 | 922 | otherwise return the original RHS or NULL_TREE. */ |
4ee9c684 | 923 | |
924 | static tree | |
75a70cf9 | 925 | ccp_fold (gimple stmt) |
4ee9c684 | 926 | { |
389dd41b | 927 | location_t loc = gimple_location (stmt); |
75a70cf9 | 928 | switch (gimple_code (stmt)) |
88dbf20f | 929 | { |
75a70cf9 | 930 | case GIMPLE_ASSIGN: |
931 | { | |
932 | enum tree_code subcode = gimple_assign_rhs_code (stmt); | |
933 | ||
934 | switch (get_gimple_rhs_class (subcode)) | |
935 | { | |
936 | case GIMPLE_SINGLE_RHS: | |
937 | { | |
938 | tree rhs = gimple_assign_rhs1 (stmt); | |
939 | enum tree_code_class kind = TREE_CODE_CLASS (subcode); | |
940 | ||
941 | if (TREE_CODE (rhs) == SSA_NAME) | |
942 | { | |
943 | /* If the RHS is an SSA_NAME, return its known constant value, | |
944 | if any. */ | |
945 | return get_value (rhs)->value; | |
946 | } | |
947 | /* Handle propagating invariant addresses into address operations. | |
948 | The folding we do here matches that in tree-ssa-forwprop.c. */ | |
949 | else if (TREE_CODE (rhs) == ADDR_EXPR) | |
950 | { | |
951 | tree *base; | |
952 | base = &TREE_OPERAND (rhs, 0); | |
953 | while (handled_component_p (*base)) | |
954 | base = &TREE_OPERAND (*base, 0); | |
955 | if (TREE_CODE (*base) == INDIRECT_REF | |
956 | && TREE_CODE (TREE_OPERAND (*base, 0)) == SSA_NAME) | |
957 | { | |
958 | prop_value_t *val = get_value (TREE_OPERAND (*base, 0)); | |
959 | if (val->lattice_val == CONSTANT | |
960 | && TREE_CODE (val->value) == ADDR_EXPR | |
fb8ed03f | 961 | && may_propagate_address_into_dereference |
962 | (val->value, *base)) | |
75a70cf9 | 963 | { |
964 | /* We need to return a new tree, not modify the IL | |
965 | or share parts of it. So play some tricks to | |
966 | avoid manually building it. */ | |
967 | tree ret, save = *base; | |
968 | *base = TREE_OPERAND (val->value, 0); | |
969 | ret = unshare_expr (rhs); | |
970 | recompute_tree_invariant_for_addr_expr (ret); | |
971 | *base = save; | |
972 | return ret; | |
973 | } | |
974 | } | |
975 | } | |
388a0bc7 | 976 | else if (TREE_CODE (rhs) == CONSTRUCTOR |
977 | && TREE_CODE (TREE_TYPE (rhs)) == VECTOR_TYPE | |
978 | && (CONSTRUCTOR_NELTS (rhs) | |
979 | == TYPE_VECTOR_SUBPARTS (TREE_TYPE (rhs)))) | |
980 | { | |
981 | unsigned i; | |
982 | tree val, list; | |
983 | ||
984 | list = NULL_TREE; | |
985 | FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (rhs), i, val) | |
986 | { | |
987 | if (TREE_CODE (val) == SSA_NAME | |
988 | && get_value (val)->lattice_val == CONSTANT) | |
989 | val = get_value (val)->value; | |
990 | if (TREE_CODE (val) == INTEGER_CST | |
991 | || TREE_CODE (val) == REAL_CST | |
992 | || TREE_CODE (val) == FIXED_CST) | |
993 | list = tree_cons (NULL_TREE, val, list); | |
994 | else | |
995 | return NULL_TREE; | |
996 | } | |
997 | ||
998 | return build_vector (TREE_TYPE (rhs), nreverse (list)); | |
999 | } | |
4ee9c684 | 1000 | |
75a70cf9 | 1001 | if (kind == tcc_reference) |
3e4be816 | 1002 | { |
0fefde02 | 1003 | if ((TREE_CODE (rhs) == VIEW_CONVERT_EXPR |
1004 | || TREE_CODE (rhs) == REALPART_EXPR | |
1005 | || TREE_CODE (rhs) == IMAGPART_EXPR) | |
3e4be816 | 1006 | && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME) |
1007 | { | |
1008 | prop_value_t *val = get_value (TREE_OPERAND (rhs, 0)); | |
1009 | if (val->lattice_val == CONSTANT) | |
389dd41b | 1010 | return fold_unary_loc (EXPR_LOCATION (rhs), |
1011 | TREE_CODE (rhs), | |
3e4be816 | 1012 | TREE_TYPE (rhs), val->value); |
1013 | } | |
8edeb88b | 1014 | else if (TREE_CODE (rhs) == INDIRECT_REF |
1015 | && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME) | |
1016 | { | |
1017 | prop_value_t *val = get_value (TREE_OPERAND (rhs, 0)); | |
1018 | if (val->lattice_val == CONSTANT | |
1019 | && TREE_CODE (val->value) == ADDR_EXPR | |
1020 | && useless_type_conversion_p (TREE_TYPE (rhs), | |
1021 | TREE_TYPE (TREE_TYPE (val->value)))) | |
1022 | rhs = TREE_OPERAND (val->value, 0); | |
1023 | } | |
3e4be816 | 1024 | return fold_const_aggregate_ref (rhs); |
1025 | } | |
75a70cf9 | 1026 | else if (kind == tcc_declaration) |
1027 | return get_symbol_constant_value (rhs); | |
1028 | return rhs; | |
1029 | } | |
1030 | ||
1031 | case GIMPLE_UNARY_RHS: | |
1032 | { | |
1033 | /* Handle unary operators that can appear in GIMPLE form. | |
1034 | Note that we know the single operand must be a constant, | |
1035 | so this should almost always return a simplified RHS. */ | |
1036 | tree lhs = gimple_assign_lhs (stmt); | |
1037 | tree op0 = gimple_assign_rhs1 (stmt); | |
1038 | ||
1039 | /* Simplify the operand down to a constant. */ | |
1040 | if (TREE_CODE (op0) == SSA_NAME) | |
1041 | { | |
1042 | prop_value_t *val = get_value (op0); | |
1043 | if (val->lattice_val == CONSTANT) | |
1044 | op0 = get_value (op0)->value; | |
1045 | } | |
1046 | ||
1047 | /* Conversions are useless for CCP purposes if they are | |
1048 | value-preserving. Thus the restrictions that | |
1049 | useless_type_conversion_p places for pointer type conversions | |
1050 | do not apply here. Substitution later will only substitute to | |
1051 | allowed places. */ | |
d9659041 | 1052 | if (CONVERT_EXPR_CODE_P (subcode) |
5768aeb3 | 1053 | && POINTER_TYPE_P (TREE_TYPE (lhs)) |
1054 | && POINTER_TYPE_P (TREE_TYPE (op0)) | |
1055 | /* Do not allow differences in volatile qualification | |
1056 | as this might get us confused as to whether a | |
1057 | propagation destination statement is volatile | |
1058 | or not. See PR36988. */ | |
1059 | && (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (lhs))) | |
1060 | == TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (op0))))) | |
1061 | { | |
1062 | tree tem; | |
1063 | /* Still try to generate a constant of correct type. */ | |
1064 | if (!useless_type_conversion_p (TREE_TYPE (lhs), | |
1065 | TREE_TYPE (op0)) | |
1066 | && ((tem = maybe_fold_offset_to_address | |
389dd41b | 1067 | (loc, |
e60a6f7b | 1068 | op0, integer_zero_node, TREE_TYPE (lhs))) |
5768aeb3 | 1069 | != NULL_TREE)) |
1070 | return tem; | |
1071 | return op0; | |
1072 | } | |
75a70cf9 | 1073 | |
389dd41b | 1074 | return |
1075 | fold_unary_ignore_overflow_loc (loc, subcode, | |
1076 | gimple_expr_type (stmt), op0); | |
f1fb2997 | 1077 | } |
75a70cf9 | 1078 | |
1079 | case GIMPLE_BINARY_RHS: | |
1080 | { | |
1081 | /* Handle binary operators that can appear in GIMPLE form. */ | |
1082 | tree op0 = gimple_assign_rhs1 (stmt); | |
1083 | tree op1 = gimple_assign_rhs2 (stmt); | |
1084 | ||
1085 | /* Simplify the operands down to constants when appropriate. */ | |
1086 | if (TREE_CODE (op0) == SSA_NAME) | |
1087 | { | |
1088 | prop_value_t *val = get_value (op0); | |
1089 | if (val->lattice_val == CONSTANT) | |
1090 | op0 = val->value; | |
1091 | } | |
1092 | ||
1093 | if (TREE_CODE (op1) == SSA_NAME) | |
1094 | { | |
1095 | prop_value_t *val = get_value (op1); | |
1096 | if (val->lattice_val == CONSTANT) | |
1097 | op1 = val->value; | |
1098 | } | |
1099 | ||
5768aeb3 | 1100 | /* Fold &foo + CST into an invariant reference if possible. */ |
1101 | if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR | |
1102 | && TREE_CODE (op0) == ADDR_EXPR | |
1103 | && TREE_CODE (op1) == INTEGER_CST) | |
1104 | { | |
e60a6f7b | 1105 | tree tem = maybe_fold_offset_to_address |
4c0d4e21 | 1106 | (loc, op0, op1, TREE_TYPE (op0)); |
5768aeb3 | 1107 | if (tem != NULL_TREE) |
1108 | return tem; | |
1109 | } | |
1110 | ||
389dd41b | 1111 | return fold_binary_loc (loc, subcode, |
1112 | gimple_expr_type (stmt), op0, op1); | |
75a70cf9 | 1113 | } |
1114 | ||
1115 | default: | |
1116 | gcc_unreachable (); | |
1117 | } | |
1118 | } | |
1119 | break; | |
4ee9c684 | 1120 | |
75a70cf9 | 1121 | case GIMPLE_CALL: |
f257af64 | 1122 | { |
1123 | tree fn = gimple_call_fn (stmt); | |
1124 | prop_value_t *val; | |
1125 | ||
1126 | if (TREE_CODE (fn) == SSA_NAME) | |
1127 | { | |
1128 | val = get_value (fn); | |
1129 | if (val->lattice_val == CONSTANT) | |
1130 | fn = val->value; | |
1131 | } | |
1132 | if (TREE_CODE (fn) == ADDR_EXPR | |
8ef4f124 | 1133 | && TREE_CODE (TREE_OPERAND (fn, 0)) == FUNCTION_DECL |
f257af64 | 1134 | && DECL_BUILT_IN (TREE_OPERAND (fn, 0))) |
1135 | { | |
1136 | tree *args = XALLOCAVEC (tree, gimple_call_num_args (stmt)); | |
1137 | tree call, retval; | |
1138 | unsigned i; | |
1139 | for (i = 0; i < gimple_call_num_args (stmt); ++i) | |
1140 | { | |
1141 | args[i] = gimple_call_arg (stmt, i); | |
1142 | if (TREE_CODE (args[i]) == SSA_NAME) | |
1143 | { | |
1144 | val = get_value (args[i]); | |
1145 | if (val->lattice_val == CONSTANT) | |
1146 | args[i] = val->value; | |
1147 | } | |
1148 | } | |
389dd41b | 1149 | call = build_call_array_loc (loc, |
1150 | gimple_call_return_type (stmt), | |
1151 | fn, gimple_call_num_args (stmt), args); | |
1152 | retval = fold_call_expr (EXPR_LOCATION (call), call, false); | |
f257af64 | 1153 | if (retval) |
1154 | /* fold_call_expr wraps the result inside a NOP_EXPR. */ | |
1155 | STRIP_NOPS (retval); | |
1156 | return retval; | |
1157 | } | |
1158 | return NULL_TREE; | |
1159 | } | |
4ee9c684 | 1160 | |
75a70cf9 | 1161 | case GIMPLE_COND: |
1162 | { | |
1163 | /* Handle comparison operators that can appear in GIMPLE form. */ | |
1164 | tree op0 = gimple_cond_lhs (stmt); | |
1165 | tree op1 = gimple_cond_rhs (stmt); | |
1166 | enum tree_code code = gimple_cond_code (stmt); | |
1167 | ||
1168 | /* Simplify the operands down to constants when appropriate. */ | |
1169 | if (TREE_CODE (op0) == SSA_NAME) | |
1170 | { | |
1171 | prop_value_t *val = get_value (op0); | |
1172 | if (val->lattice_val == CONSTANT) | |
1173 | op0 = val->value; | |
1174 | } | |
1175 | ||
1176 | if (TREE_CODE (op1) == SSA_NAME) | |
1177 | { | |
1178 | prop_value_t *val = get_value (op1); | |
1179 | if (val->lattice_val == CONSTANT) | |
1180 | op1 = val->value; | |
1181 | } | |
1182 | ||
389dd41b | 1183 | return fold_binary_loc (loc, code, boolean_type_node, op0, op1); |
75a70cf9 | 1184 | } |
4ee9c684 | 1185 | |
75a70cf9 | 1186 | case GIMPLE_SWITCH: |
1187 | { | |
1188 | tree rhs = gimple_switch_index (stmt); | |
04236c3a | 1189 | |
75a70cf9 | 1190 | if (TREE_CODE (rhs) == SSA_NAME) |
1191 | { | |
1192 | /* If the RHS is an SSA_NAME, return its known constant value, | |
1193 | if any. */ | |
1194 | return get_value (rhs)->value; | |
1195 | } | |
04236c3a | 1196 | |
75a70cf9 | 1197 | return rhs; |
1198 | } | |
912f109f | 1199 | |
75a70cf9 | 1200 | default: |
1201 | gcc_unreachable (); | |
4ee9c684 | 1202 | } |
4ee9c684 | 1203 | } |
1204 | ||
1205 | ||
8782adcf | 1206 | /* Return the tree representing the element referenced by T if T is an |
1207 | ARRAY_REF or COMPONENT_REF into constant aggregates. Return | |
1208 | NULL_TREE otherwise. */ | |
1209 | ||
e004838d | 1210 | tree |
8782adcf | 1211 | fold_const_aggregate_ref (tree t) |
1212 | { | |
1213 | prop_value_t *value; | |
c75b4594 | 1214 | tree base, ctor, idx, field; |
1215 | unsigned HOST_WIDE_INT cnt; | |
1216 | tree cfield, cval; | |
8782adcf | 1217 | |
8edeb88b | 1218 | if (TREE_CODE_CLASS (TREE_CODE (t)) == tcc_declaration) |
1219 | return get_symbol_constant_value (t); | |
1220 | ||
8782adcf | 1221 | switch (TREE_CODE (t)) |
1222 | { | |
1223 | case ARRAY_REF: | |
1224 | /* Get a CONSTRUCTOR. If BASE is a VAR_DECL, get its | |
1225 | DECL_INITIAL. If BASE is a nested reference into another | |
1226 | ARRAY_REF or COMPONENT_REF, make a recursive call to resolve | |
1227 | the inner reference. */ | |
1228 | base = TREE_OPERAND (t, 0); | |
1229 | switch (TREE_CODE (base)) | |
1230 | { | |
1231 | case VAR_DECL: | |
1232 | if (!TREE_READONLY (base) | |
1233 | || TREE_CODE (TREE_TYPE (base)) != ARRAY_TYPE | |
1234 | || !targetm.binds_local_p (base)) | |
1235 | return NULL_TREE; | |
1236 | ||
1237 | ctor = DECL_INITIAL (base); | |
1238 | break; | |
1239 | ||
1240 | case ARRAY_REF: | |
1241 | case COMPONENT_REF: | |
1242 | ctor = fold_const_aggregate_ref (base); | |
1243 | break; | |
1244 | ||
04236c3a | 1245 | case STRING_CST: |
1246 | case CONSTRUCTOR: | |
1247 | ctor = base; | |
1248 | break; | |
1249 | ||
8782adcf | 1250 | default: |
1251 | return NULL_TREE; | |
1252 | } | |
1253 | ||
1254 | if (ctor == NULL_TREE | |
4f61cce6 | 1255 | || (TREE_CODE (ctor) != CONSTRUCTOR |
1256 | && TREE_CODE (ctor) != STRING_CST) | |
8782adcf | 1257 | || !TREE_STATIC (ctor)) |
1258 | return NULL_TREE; | |
1259 | ||
1260 | /* Get the index. If we have an SSA_NAME, try to resolve it | |
1261 | with the current lattice value for the SSA_NAME. */ | |
1262 | idx = TREE_OPERAND (t, 1); | |
1263 | switch (TREE_CODE (idx)) | |
1264 | { | |
1265 | case SSA_NAME: | |
bfa30570 | 1266 | if ((value = get_value (idx)) |
8782adcf | 1267 | && value->lattice_val == CONSTANT |
1268 | && TREE_CODE (value->value) == INTEGER_CST) | |
1269 | idx = value->value; | |
1270 | else | |
1271 | return NULL_TREE; | |
1272 | break; | |
1273 | ||
1274 | case INTEGER_CST: | |
1275 | break; | |
1276 | ||
1277 | default: | |
1278 | return NULL_TREE; | |
1279 | } | |
1280 | ||
4f61cce6 | 1281 | /* Fold read from constant string. */ |
1282 | if (TREE_CODE (ctor) == STRING_CST) | |
1283 | { | |
1284 | if ((TYPE_MODE (TREE_TYPE (t)) | |
1285 | == TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) | |
1286 | && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) | |
1287 | == MODE_INT) | |
1288 | && GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) == 1 | |
1289 | && compare_tree_int (idx, TREE_STRING_LENGTH (ctor)) < 0) | |
7b050b7b | 1290 | return build_int_cst_type (TREE_TYPE (t), |
1291 | (TREE_STRING_POINTER (ctor) | |
1292 | [TREE_INT_CST_LOW (idx)])); | |
4f61cce6 | 1293 | return NULL_TREE; |
1294 | } | |
1295 | ||
8782adcf | 1296 | /* Whoo-hoo! I'll fold ya baby. Yeah! */ |
c75b4594 | 1297 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, cval) |
1298 | if (tree_int_cst_equal (cfield, idx)) | |
590d65aa | 1299 | { |
1300 | STRIP_USELESS_TYPE_CONVERSION (cval); | |
3a44a278 | 1301 | if (TREE_CODE (cval) == ADDR_EXPR) |
1302 | { | |
1303 | tree base = get_base_address (TREE_OPERAND (cval, 0)); | |
1304 | if (base && TREE_CODE (base) == VAR_DECL) | |
1305 | add_referenced_var (base); | |
1306 | } | |
590d65aa | 1307 | return cval; |
1308 | } | |
8782adcf | 1309 | break; |
1310 | ||
1311 | case COMPONENT_REF: | |
1312 | /* Get a CONSTRUCTOR. If BASE is a VAR_DECL, get its | |
1313 | DECL_INITIAL. If BASE is a nested reference into another | |
1314 | ARRAY_REF or COMPONENT_REF, make a recursive call to resolve | |
1315 | the inner reference. */ | |
1316 | base = TREE_OPERAND (t, 0); | |
1317 | switch (TREE_CODE (base)) | |
1318 | { | |
1319 | case VAR_DECL: | |
1320 | if (!TREE_READONLY (base) | |
1321 | || TREE_CODE (TREE_TYPE (base)) != RECORD_TYPE | |
1322 | || !targetm.binds_local_p (base)) | |
1323 | return NULL_TREE; | |
1324 | ||
1325 | ctor = DECL_INITIAL (base); | |
1326 | break; | |
1327 | ||
1328 | case ARRAY_REF: | |
1329 | case COMPONENT_REF: | |
1330 | ctor = fold_const_aggregate_ref (base); | |
1331 | break; | |
1332 | ||
1333 | default: | |
1334 | return NULL_TREE; | |
1335 | } | |
1336 | ||
1337 | if (ctor == NULL_TREE | |
1338 | || TREE_CODE (ctor) != CONSTRUCTOR | |
1339 | || !TREE_STATIC (ctor)) | |
1340 | return NULL_TREE; | |
1341 | ||
1342 | field = TREE_OPERAND (t, 1); | |
1343 | ||
c75b4594 | 1344 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, cval) |
1345 | if (cfield == field | |
8782adcf | 1346 | /* FIXME: Handle bit-fields. */ |
c75b4594 | 1347 | && ! DECL_BIT_FIELD (cfield)) |
590d65aa | 1348 | { |
1349 | STRIP_USELESS_TYPE_CONVERSION (cval); | |
3a44a278 | 1350 | if (TREE_CODE (cval) == ADDR_EXPR) |
1351 | { | |
1352 | tree base = get_base_address (TREE_OPERAND (cval, 0)); | |
1353 | if (base && TREE_CODE (base) == VAR_DECL) | |
1354 | add_referenced_var (base); | |
1355 | } | |
590d65aa | 1356 | return cval; |
1357 | } | |
8782adcf | 1358 | break; |
1359 | ||
908cb59d | 1360 | case REALPART_EXPR: |
1361 | case IMAGPART_EXPR: | |
1362 | { | |
1363 | tree c = fold_const_aggregate_ref (TREE_OPERAND (t, 0)); | |
1364 | if (c && TREE_CODE (c) == COMPLEX_CST) | |
389dd41b | 1365 | return fold_build1_loc (EXPR_LOCATION (t), |
1366 | TREE_CODE (t), TREE_TYPE (t), c); | |
908cb59d | 1367 | break; |
1368 | } | |
04236c3a | 1369 | |
1370 | case INDIRECT_REF: | |
1371 | { | |
1372 | tree base = TREE_OPERAND (t, 0); | |
1373 | if (TREE_CODE (base) == SSA_NAME | |
1374 | && (value = get_value (base)) | |
1375 | && value->lattice_val == CONSTANT | |
65c463fd | 1376 | && TREE_CODE (value->value) == ADDR_EXPR |
1377 | && useless_type_conversion_p (TREE_TYPE (t), | |
1378 | TREE_TYPE (TREE_TYPE (value->value)))) | |
04236c3a | 1379 | return fold_const_aggregate_ref (TREE_OPERAND (value->value, 0)); |
1380 | break; | |
1381 | } | |
1382 | ||
8782adcf | 1383 | default: |
1384 | break; | |
1385 | } | |
1386 | ||
1387 | return NULL_TREE; | |
1388 | } | |
75a70cf9 | 1389 | |
1390 | /* Evaluate statement STMT. | |
1391 | Valid only for assignments, calls, conditionals, and switches. */ | |
4ee9c684 | 1392 | |
88dbf20f | 1393 | static prop_value_t |
75a70cf9 | 1394 | evaluate_stmt (gimple stmt) |
4ee9c684 | 1395 | { |
88dbf20f | 1396 | prop_value_t val; |
4f61cce6 | 1397 | tree simplified = NULL_TREE; |
88dbf20f | 1398 | ccp_lattice_t likelyvalue = likely_value (stmt); |
add6ee5e | 1399 | bool is_constant; |
88dbf20f | 1400 | |
add6ee5e | 1401 | fold_defer_overflow_warnings (); |
1402 | ||
4ee9c684 | 1403 | /* If the statement is likely to have a CONSTANT result, then try |
1404 | to fold the statement to determine the constant value. */ | |
75a70cf9 | 1405 | /* FIXME. This is the only place that we call ccp_fold. |
1406 | Since likely_value never returns CONSTANT for calls, we will | |
1407 | not attempt to fold them, including builtins that may profit. */ | |
4ee9c684 | 1408 | if (likelyvalue == CONSTANT) |
1409 | simplified = ccp_fold (stmt); | |
1410 | /* If the statement is likely to have a VARYING result, then do not | |
1411 | bother folding the statement. */ | |
04236c3a | 1412 | else if (likelyvalue == VARYING) |
75a70cf9 | 1413 | { |
590c3166 | 1414 | enum gimple_code code = gimple_code (stmt); |
75a70cf9 | 1415 | if (code == GIMPLE_ASSIGN) |
1416 | { | |
1417 | enum tree_code subcode = gimple_assign_rhs_code (stmt); | |
1418 | ||
1419 | /* Other cases cannot satisfy is_gimple_min_invariant | |
1420 | without folding. */ | |
1421 | if (get_gimple_rhs_class (subcode) == GIMPLE_SINGLE_RHS) | |
1422 | simplified = gimple_assign_rhs1 (stmt); | |
1423 | } | |
1424 | else if (code == GIMPLE_SWITCH) | |
1425 | simplified = gimple_switch_index (stmt); | |
1426 | else | |
1427 | /* These cannot satisfy is_gimple_min_invariant without folding. */ | |
1428 | gcc_assert (code == GIMPLE_CALL || code == GIMPLE_COND); | |
1429 | } | |
4ee9c684 | 1430 | |
add6ee5e | 1431 | is_constant = simplified && is_gimple_min_invariant (simplified); |
1432 | ||
1433 | fold_undefer_overflow_warnings (is_constant, stmt, 0); | |
1434 | ||
912f109f | 1435 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1436 | { | |
1437 | fprintf (dump_file, "which is likely "); | |
1438 | switch (likelyvalue) | |
1439 | { | |
1440 | case CONSTANT: | |
1441 | fprintf (dump_file, "CONSTANT"); | |
1442 | break; | |
1443 | case UNDEFINED: | |
1444 | fprintf (dump_file, "UNDEFINED"); | |
1445 | break; | |
1446 | case VARYING: | |
1447 | fprintf (dump_file, "VARYING"); | |
1448 | break; | |
1449 | default:; | |
1450 | } | |
1451 | fprintf (dump_file, "\n"); | |
1452 | } | |
1453 | ||
add6ee5e | 1454 | if (is_constant) |
4ee9c684 | 1455 | { |
1456 | /* The statement produced a constant value. */ | |
1457 | val.lattice_val = CONSTANT; | |
88dbf20f | 1458 | val.value = simplified; |
4ee9c684 | 1459 | } |
1460 | else | |
1461 | { | |
1462 | /* The statement produced a nonconstant value. If the statement | |
88dbf20f | 1463 | had UNDEFINED operands, then the result of the statement |
1464 | should be UNDEFINED. Otherwise, the statement is VARYING. */ | |
bfa30570 | 1465 | if (likelyvalue == UNDEFINED) |
b765fa12 | 1466 | val.lattice_val = likelyvalue; |
1467 | else | |
1468 | val.lattice_val = VARYING; | |
1469 | ||
88dbf20f | 1470 | val.value = NULL_TREE; |
4ee9c684 | 1471 | } |
41511585 | 1472 | |
1473 | return val; | |
4ee9c684 | 1474 | } |
1475 | ||
6688f8ec | 1476 | /* Fold the stmt at *GSI with CCP specific information that propagating |
1477 | and regular folding does not catch. */ | |
1478 | ||
1479 | static bool | |
1480 | ccp_fold_stmt (gimple_stmt_iterator *gsi) | |
1481 | { | |
1482 | gimple stmt = gsi_stmt (*gsi); | |
1483 | prop_value_t val; | |
1484 | ||
1485 | if (gimple_code (stmt) != GIMPLE_COND) | |
1486 | return false; | |
1487 | ||
1488 | /* Statement evaluation will handle type mismatches in constants | |
1489 | more gracefully than the final propagation. This allows us to | |
1490 | fold more conditionals here. */ | |
1491 | val = evaluate_stmt (stmt); | |
1492 | if (val.lattice_val != CONSTANT | |
1493 | || TREE_CODE (val.value) != INTEGER_CST) | |
1494 | return false; | |
1495 | ||
1496 | if (integer_zerop (val.value)) | |
1497 | gimple_cond_make_false (stmt); | |
1498 | else | |
1499 | gimple_cond_make_true (stmt); | |
1500 | ||
1501 | return true; | |
1502 | } | |
1503 | ||
41511585 | 1504 | /* Visit the assignment statement STMT. Set the value of its LHS to the |
88dbf20f | 1505 | value computed by the RHS and store LHS in *OUTPUT_P. If STMT |
1506 | creates virtual definitions, set the value of each new name to that | |
75a70cf9 | 1507 | of the RHS (if we can derive a constant out of the RHS). |
1508 | Value-returning call statements also perform an assignment, and | |
1509 | are handled here. */ | |
4ee9c684 | 1510 | |
41511585 | 1511 | static enum ssa_prop_result |
75a70cf9 | 1512 | visit_assignment (gimple stmt, tree *output_p) |
4ee9c684 | 1513 | { |
88dbf20f | 1514 | prop_value_t val; |
88dbf20f | 1515 | enum ssa_prop_result retval; |
4ee9c684 | 1516 | |
75a70cf9 | 1517 | tree lhs = gimple_get_lhs (stmt); |
4ee9c684 | 1518 | |
75a70cf9 | 1519 | gcc_assert (gimple_code (stmt) != GIMPLE_CALL |
1520 | || gimple_call_lhs (stmt) != NULL_TREE); | |
1521 | ||
1522 | if (gimple_assign_copy_p (stmt)) | |
41511585 | 1523 | { |
75a70cf9 | 1524 | tree rhs = gimple_assign_rhs1 (stmt); |
88dbf20f | 1525 | |
75a70cf9 | 1526 | if (TREE_CODE (rhs) == SSA_NAME) |
1527 | { | |
1528 | /* For a simple copy operation, we copy the lattice values. */ | |
1529 | prop_value_t *nval = get_value (rhs); | |
1530 | val = *nval; | |
1531 | } | |
88dbf20f | 1532 | else |
75a70cf9 | 1533 | val = evaluate_stmt (stmt); |
41511585 | 1534 | } |
1535 | else | |
75a70cf9 | 1536 | /* Evaluate the statement, which could be |
1537 | either a GIMPLE_ASSIGN or a GIMPLE_CALL. */ | |
04236c3a | 1538 | val = evaluate_stmt (stmt); |
4ee9c684 | 1539 | |
88dbf20f | 1540 | retval = SSA_PROP_NOT_INTERESTING; |
4ee9c684 | 1541 | |
41511585 | 1542 | /* Set the lattice value of the statement's output. */ |
88dbf20f | 1543 | if (TREE_CODE (lhs) == SSA_NAME) |
4ee9c684 | 1544 | { |
88dbf20f | 1545 | /* If STMT is an assignment to an SSA_NAME, we only have one |
1546 | value to set. */ | |
1547 | if (set_lattice_value (lhs, val)) | |
1548 | { | |
1549 | *output_p = lhs; | |
1550 | if (val.lattice_val == VARYING) | |
1551 | retval = SSA_PROP_VARYING; | |
1552 | else | |
1553 | retval = SSA_PROP_INTERESTING; | |
1554 | } | |
4ee9c684 | 1555 | } |
88dbf20f | 1556 | |
1557 | return retval; | |
4ee9c684 | 1558 | } |
1559 | ||
4ee9c684 | 1560 | |
41511585 | 1561 | /* Visit the conditional statement STMT. Return SSA_PROP_INTERESTING |
1562 | if it can determine which edge will be taken. Otherwise, return | |
1563 | SSA_PROP_VARYING. */ | |
1564 | ||
1565 | static enum ssa_prop_result | |
75a70cf9 | 1566 | visit_cond_stmt (gimple stmt, edge *taken_edge_p) |
4ee9c684 | 1567 | { |
88dbf20f | 1568 | prop_value_t val; |
41511585 | 1569 | basic_block block; |
1570 | ||
75a70cf9 | 1571 | block = gimple_bb (stmt); |
41511585 | 1572 | val = evaluate_stmt (stmt); |
1573 | ||
1574 | /* Find which edge out of the conditional block will be taken and add it | |
1575 | to the worklist. If no single edge can be determined statically, | |
1576 | return SSA_PROP_VARYING to feed all the outgoing edges to the | |
1577 | propagation engine. */ | |
88dbf20f | 1578 | *taken_edge_p = val.value ? find_taken_edge (block, val.value) : 0; |
41511585 | 1579 | if (*taken_edge_p) |
1580 | return SSA_PROP_INTERESTING; | |
1581 | else | |
1582 | return SSA_PROP_VARYING; | |
4ee9c684 | 1583 | } |
1584 | ||
4ee9c684 | 1585 | |
41511585 | 1586 | /* Evaluate statement STMT. If the statement produces an output value and |
1587 | its evaluation changes the lattice value of its output, return | |
1588 | SSA_PROP_INTERESTING and set *OUTPUT_P to the SSA_NAME holding the | |
1589 | output value. | |
1590 | ||
1591 | If STMT is a conditional branch and we can determine its truth | |
1592 | value, set *TAKEN_EDGE_P accordingly. If STMT produces a varying | |
1593 | value, return SSA_PROP_VARYING. */ | |
4ee9c684 | 1594 | |
41511585 | 1595 | static enum ssa_prop_result |
75a70cf9 | 1596 | ccp_visit_stmt (gimple stmt, edge *taken_edge_p, tree *output_p) |
41511585 | 1597 | { |
41511585 | 1598 | tree def; |
1599 | ssa_op_iter iter; | |
4ee9c684 | 1600 | |
41511585 | 1601 | if (dump_file && (dump_flags & TDF_DETAILS)) |
4ee9c684 | 1602 | { |
88dbf20f | 1603 | fprintf (dump_file, "\nVisiting statement:\n"); |
75a70cf9 | 1604 | print_gimple_stmt (dump_file, stmt, 0, dump_flags); |
4ee9c684 | 1605 | } |
4ee9c684 | 1606 | |
75a70cf9 | 1607 | switch (gimple_code (stmt)) |
4ee9c684 | 1608 | { |
75a70cf9 | 1609 | case GIMPLE_ASSIGN: |
1610 | /* If the statement is an assignment that produces a single | |
1611 | output value, evaluate its RHS to see if the lattice value of | |
1612 | its output has changed. */ | |
1613 | return visit_assignment (stmt, output_p); | |
1614 | ||
1615 | case GIMPLE_CALL: | |
1616 | /* A value-returning call also performs an assignment. */ | |
1617 | if (gimple_call_lhs (stmt) != NULL_TREE) | |
1618 | return visit_assignment (stmt, output_p); | |
1619 | break; | |
1620 | ||
1621 | case GIMPLE_COND: | |
1622 | case GIMPLE_SWITCH: | |
1623 | /* If STMT is a conditional branch, see if we can determine | |
1624 | which branch will be taken. */ | |
1625 | /* FIXME. It appears that we should be able to optimize | |
1626 | computed GOTOs here as well. */ | |
1627 | return visit_cond_stmt (stmt, taken_edge_p); | |
1628 | ||
1629 | default: | |
1630 | break; | |
4ee9c684 | 1631 | } |
4ee9c684 | 1632 | |
41511585 | 1633 | /* Any other kind of statement is not interesting for constant |
1634 | propagation and, therefore, not worth simulating. */ | |
41511585 | 1635 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1636 | fprintf (dump_file, "No interesting values produced. Marked VARYING.\n"); | |
4ee9c684 | 1637 | |
41511585 | 1638 | /* Definitions made by statements other than assignments to |
1639 | SSA_NAMEs represent unknown modifications to their outputs. | |
1640 | Mark them VARYING. */ | |
88dbf20f | 1641 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS) |
1642 | { | |
61207d43 | 1643 | prop_value_t v = { VARYING, NULL_TREE }; |
88dbf20f | 1644 | set_lattice_value (def, v); |
1645 | } | |
4ee9c684 | 1646 | |
41511585 | 1647 | return SSA_PROP_VARYING; |
1648 | } | |
4ee9c684 | 1649 | |
4ee9c684 | 1650 | |
88dbf20f | 1651 | /* Main entry point for SSA Conditional Constant Propagation. */ |
41511585 | 1652 | |
33a34f1e | 1653 | static unsigned int |
61207d43 | 1654 | do_ssa_ccp (void) |
41511585 | 1655 | { |
1656 | ccp_initialize (); | |
1657 | ssa_propagate (ccp_visit_stmt, ccp_visit_phi_node); | |
33a34f1e | 1658 | if (ccp_finalize ()) |
eb9161e7 | 1659 | return (TODO_cleanup_cfg | TODO_update_ssa | TODO_remove_unused_locals); |
33a34f1e | 1660 | else |
1661 | return 0; | |
4ee9c684 | 1662 | } |
1663 | ||
5664499b | 1664 | |
1665 | static bool | |
41511585 | 1666 | gate_ccp (void) |
5664499b | 1667 | { |
41511585 | 1668 | return flag_tree_ccp != 0; |
5664499b | 1669 | } |
1670 | ||
4ee9c684 | 1671 | |
20099e35 | 1672 | struct gimple_opt_pass pass_ccp = |
41511585 | 1673 | { |
20099e35 | 1674 | { |
1675 | GIMPLE_PASS, | |
41511585 | 1676 | "ccp", /* name */ |
1677 | gate_ccp, /* gate */ | |
88dbf20f | 1678 | do_ssa_ccp, /* execute */ |
41511585 | 1679 | NULL, /* sub */ |
1680 | NULL, /* next */ | |
1681 | 0, /* static_pass_number */ | |
1682 | TV_TREE_CCP, /* tv_id */ | |
49290934 | 1683 | PROP_cfg | PROP_ssa, /* properties_required */ |
41511585 | 1684 | 0, /* properties_provided */ |
b6246c40 | 1685 | 0, /* properties_destroyed */ |
41511585 | 1686 | 0, /* todo_flags_start */ |
33a34f1e | 1687 | TODO_dump_func | TODO_verify_ssa |
20099e35 | 1688 | | TODO_verify_stmts | TODO_ggc_collect/* todo_flags_finish */ |
1689 | } | |
41511585 | 1690 | }; |
4ee9c684 | 1691 | |
4ee9c684 | 1692 | |
304557cd | 1693 | /* A subroutine of fold_stmt. Attempts to fold *(A+O) to A[X]. |
4ee9c684 | 1694 | BASE is an array type. OFFSET is a byte displacement. ORIG_TYPE |
e60a6f7b | 1695 | is the desired result type. |
1696 | ||
1697 | LOC is the location of the original expression. */ | |
4ee9c684 | 1698 | |
1699 | static tree | |
e60a6f7b | 1700 | maybe_fold_offset_to_array_ref (location_t loc, tree base, tree offset, |
1701 | tree orig_type, | |
b7488229 | 1702 | bool allow_negative_idx) |
4ee9c684 | 1703 | { |
e71da05f | 1704 | tree min_idx, idx, idx_type, elt_offset = integer_zero_node; |
6374121b | 1705 | tree array_type, elt_type, elt_size; |
b513c084 | 1706 | tree domain_type; |
6374121b | 1707 | |
1708 | /* If BASE is an ARRAY_REF, we can pick up another offset (this time | |
1709 | measured in units of the size of elements type) from that ARRAY_REF). | |
1710 | We can't do anything if either is variable. | |
1711 | ||
1712 | The case we handle here is *(&A[N]+O). */ | |
1713 | if (TREE_CODE (base) == ARRAY_REF) | |
1714 | { | |
1715 | tree low_bound = array_ref_low_bound (base); | |
1716 | ||
1717 | elt_offset = TREE_OPERAND (base, 1); | |
1718 | if (TREE_CODE (low_bound) != INTEGER_CST | |
1719 | || TREE_CODE (elt_offset) != INTEGER_CST) | |
1720 | return NULL_TREE; | |
1721 | ||
1722 | elt_offset = int_const_binop (MINUS_EXPR, elt_offset, low_bound, 0); | |
1723 | base = TREE_OPERAND (base, 0); | |
1724 | } | |
4ee9c684 | 1725 | |
1726 | /* Ignore stupid user tricks of indexing non-array variables. */ | |
1727 | array_type = TREE_TYPE (base); | |
1728 | if (TREE_CODE (array_type) != ARRAY_TYPE) | |
1729 | return NULL_TREE; | |
1730 | elt_type = TREE_TYPE (array_type); | |
c8ca3ee7 | 1731 | if (!useless_type_conversion_p (orig_type, elt_type)) |
4ee9c684 | 1732 | return NULL_TREE; |
e71da05f | 1733 | |
1734 | /* Use signed size type for intermediate computation on the index. */ | |
1735 | idx_type = signed_type_for (size_type_node); | |
1736 | ||
6374121b | 1737 | /* If OFFSET and ELT_OFFSET are zero, we don't care about the size of the |
1738 | element type (so we can use the alignment if it's not constant). | |
1739 | Otherwise, compute the offset as an index by using a division. If the | |
1740 | division isn't exact, then don't do anything. */ | |
4ee9c684 | 1741 | elt_size = TYPE_SIZE_UNIT (elt_type); |
3b45913d | 1742 | if (!elt_size) |
1743 | return NULL; | |
6374121b | 1744 | if (integer_zerop (offset)) |
1745 | { | |
1746 | if (TREE_CODE (elt_size) != INTEGER_CST) | |
1747 | elt_size = size_int (TYPE_ALIGN (elt_type)); | |
4ee9c684 | 1748 | |
e71da05f | 1749 | idx = build_int_cst (idx_type, 0); |
6374121b | 1750 | } |
1751 | else | |
1752 | { | |
1753 | unsigned HOST_WIDE_INT lquo, lrem; | |
1754 | HOST_WIDE_INT hquo, hrem; | |
e71da05f | 1755 | double_int soffset; |
6374121b | 1756 | |
e71da05f | 1757 | /* The final array offset should be signed, so we need |
1758 | to sign-extend the (possibly pointer) offset here | |
1759 | and use signed division. */ | |
1760 | soffset = double_int_sext (tree_to_double_int (offset), | |
1761 | TYPE_PRECISION (TREE_TYPE (offset))); | |
6374121b | 1762 | if (TREE_CODE (elt_size) != INTEGER_CST |
e71da05f | 1763 | || div_and_round_double (TRUNC_DIV_EXPR, 0, |
1764 | soffset.low, soffset.high, | |
6374121b | 1765 | TREE_INT_CST_LOW (elt_size), |
1766 | TREE_INT_CST_HIGH (elt_size), | |
1767 | &lquo, &hquo, &lrem, &hrem) | |
1768 | || lrem || hrem) | |
1769 | return NULL_TREE; | |
4ee9c684 | 1770 | |
e71da05f | 1771 | idx = build_int_cst_wide (idx_type, lquo, hquo); |
6374121b | 1772 | } |
1773 | ||
1774 | /* Assume the low bound is zero. If there is a domain type, get the | |
1775 | low bound, if any, convert the index into that type, and add the | |
1776 | low bound. */ | |
e71da05f | 1777 | min_idx = build_int_cst (idx_type, 0); |
b513c084 | 1778 | domain_type = TYPE_DOMAIN (array_type); |
1779 | if (domain_type) | |
4ee9c684 | 1780 | { |
b513c084 | 1781 | idx_type = domain_type; |
e71da05f | 1782 | if (TYPE_MIN_VALUE (idx_type)) |
1783 | min_idx = TYPE_MIN_VALUE (idx_type); | |
6374121b | 1784 | else |
e71da05f | 1785 | min_idx = fold_convert (idx_type, min_idx); |
6374121b | 1786 | |
1787 | if (TREE_CODE (min_idx) != INTEGER_CST) | |
1788 | return NULL_TREE; | |
1789 | ||
e71da05f | 1790 | elt_offset = fold_convert (idx_type, elt_offset); |
4ee9c684 | 1791 | } |
1792 | ||
6374121b | 1793 | if (!integer_zerop (min_idx)) |
1794 | idx = int_const_binop (PLUS_EXPR, idx, min_idx, 0); | |
1795 | if (!integer_zerop (elt_offset)) | |
1796 | idx = int_const_binop (PLUS_EXPR, idx, elt_offset, 0); | |
1797 | ||
e71da05f | 1798 | /* Make sure to possibly truncate late after offsetting. */ |
1799 | idx = fold_convert (idx_type, idx); | |
1800 | ||
b513c084 | 1801 | /* We don't want to construct access past array bounds. For example |
b7488229 | 1802 | char *(c[4]); |
1803 | c[3][2]; | |
1804 | should not be simplified into (*c)[14] or tree-vrp will | |
1805 | give false warnings. The same is true for | |
1806 | struct A { long x; char d[0]; } *a; | |
1807 | (char *)a - 4; | |
1808 | which should be not folded to &a->d[-8]. */ | |
1809 | if (domain_type | |
1810 | && TYPE_MAX_VALUE (domain_type) | |
b513c084 | 1811 | && TREE_CODE (TYPE_MAX_VALUE (domain_type)) == INTEGER_CST) |
1812 | { | |
1813 | tree up_bound = TYPE_MAX_VALUE (domain_type); | |
1814 | ||
1815 | if (tree_int_cst_lt (up_bound, idx) | |
1816 | /* Accesses after the end of arrays of size 0 (gcc | |
1817 | extension) and 1 are likely intentional ("struct | |
1818 | hack"). */ | |
1819 | && compare_tree_int (up_bound, 1) > 0) | |
1820 | return NULL_TREE; | |
1821 | } | |
b7488229 | 1822 | if (domain_type |
1823 | && TYPE_MIN_VALUE (domain_type)) | |
1824 | { | |
1825 | if (!allow_negative_idx | |
1826 | && TREE_CODE (TYPE_MIN_VALUE (domain_type)) == INTEGER_CST | |
1827 | && tree_int_cst_lt (idx, TYPE_MIN_VALUE (domain_type))) | |
1828 | return NULL_TREE; | |
1829 | } | |
1830 | else if (!allow_negative_idx | |
1831 | && compare_tree_int (idx, 0) < 0) | |
1832 | return NULL_TREE; | |
b513c084 | 1833 | |
e60a6f7b | 1834 | { |
1835 | tree t = build4 (ARRAY_REF, elt_type, base, idx, NULL_TREE, NULL_TREE); | |
1836 | SET_EXPR_LOCATION (t, loc); | |
1837 | return t; | |
1838 | } | |
4ee9c684 | 1839 | } |
1840 | ||
41511585 | 1841 | |
3b45913d | 1842 | /* Attempt to fold *(S+O) to S.X. |
4ee9c684 | 1843 | BASE is a record type. OFFSET is a byte displacement. ORIG_TYPE |
e60a6f7b | 1844 | is the desired result type. |
1845 | ||
1846 | LOC is the location of the original expression. */ | |
4ee9c684 | 1847 | |
3b45913d | 1848 | static tree |
e60a6f7b | 1849 | maybe_fold_offset_to_component_ref (location_t loc, tree record_type, |
3d8f99df | 1850 | tree base, tree offset, tree orig_type) |
4ee9c684 | 1851 | { |
6d5d8428 | 1852 | tree f, t, field_type, tail_array_field, field_offset; |
d9745cea | 1853 | tree ret; |
1854 | tree new_base; | |
4ee9c684 | 1855 | |
1856 | if (TREE_CODE (record_type) != RECORD_TYPE | |
1857 | && TREE_CODE (record_type) != UNION_TYPE | |
1858 | && TREE_CODE (record_type) != QUAL_UNION_TYPE) | |
1859 | return NULL_TREE; | |
1860 | ||
1861 | /* Short-circuit silly cases. */ | |
c8ca3ee7 | 1862 | if (useless_type_conversion_p (record_type, orig_type)) |
4ee9c684 | 1863 | return NULL_TREE; |
1864 | ||
1865 | tail_array_field = NULL_TREE; | |
1866 | for (f = TYPE_FIELDS (record_type); f ; f = TREE_CHAIN (f)) | |
1867 | { | |
1868 | int cmp; | |
1869 | ||
1870 | if (TREE_CODE (f) != FIELD_DECL) | |
1871 | continue; | |
1872 | if (DECL_BIT_FIELD (f)) | |
1873 | continue; | |
6d5d8428 | 1874 | |
3b45913d | 1875 | if (!DECL_FIELD_OFFSET (f)) |
1876 | continue; | |
6d5d8428 | 1877 | field_offset = byte_position (f); |
1878 | if (TREE_CODE (field_offset) != INTEGER_CST) | |
4ee9c684 | 1879 | continue; |
1880 | ||
1881 | /* ??? Java creates "interesting" fields for representing base classes. | |
1882 | They have no name, and have no context. With no context, we get into | |
1883 | trouble with nonoverlapping_component_refs_p. Skip them. */ | |
1884 | if (!DECL_FIELD_CONTEXT (f)) | |
1885 | continue; | |
1886 | ||
1887 | /* The previous array field isn't at the end. */ | |
1888 | tail_array_field = NULL_TREE; | |
1889 | ||
1890 | /* Check to see if this offset overlaps with the field. */ | |
6d5d8428 | 1891 | cmp = tree_int_cst_compare (field_offset, offset); |
4ee9c684 | 1892 | if (cmp > 0) |
1893 | continue; | |
1894 | ||
1895 | field_type = TREE_TYPE (f); | |
4ee9c684 | 1896 | |
1897 | /* Here we exactly match the offset being checked. If the types match, | |
1898 | then we can return that field. */ | |
115073ff | 1899 | if (cmp == 0 |
c8ca3ee7 | 1900 | && useless_type_conversion_p (orig_type, field_type)) |
4ee9c684 | 1901 | { |
40b19772 | 1902 | t = build3 (COMPONENT_REF, field_type, base, f, NULL_TREE); |
4ee9c684 | 1903 | return t; |
1904 | } | |
115073ff | 1905 | |
1906 | /* Don't care about offsets into the middle of scalars. */ | |
1907 | if (!AGGREGATE_TYPE_P (field_type)) | |
1908 | continue; | |
4ee9c684 | 1909 | |
115073ff | 1910 | /* Check for array at the end of the struct. This is often |
1911 | used as for flexible array members. We should be able to | |
1912 | turn this into an array access anyway. */ | |
1913 | if (TREE_CODE (field_type) == ARRAY_TYPE) | |
1914 | tail_array_field = f; | |
1915 | ||
1916 | /* Check the end of the field against the offset. */ | |
1917 | if (!DECL_SIZE_UNIT (f) | |
1918 | || TREE_CODE (DECL_SIZE_UNIT (f)) != INTEGER_CST) | |
1919 | continue; | |
1920 | t = int_const_binop (MINUS_EXPR, offset, field_offset, 1); | |
1921 | if (!tree_int_cst_lt (t, DECL_SIZE_UNIT (f))) | |
1922 | continue; | |
4ee9c684 | 1923 | |
115073ff | 1924 | /* If we matched, then set offset to the displacement into |
1925 | this field. */ | |
3d8f99df | 1926 | new_base = build3 (COMPONENT_REF, field_type, base, f, NULL_TREE); |
1927 | SET_EXPR_LOCATION (new_base, loc); | |
d9745cea | 1928 | |
1929 | /* Recurse to possibly find the match. */ | |
e60a6f7b | 1930 | ret = maybe_fold_offset_to_array_ref (loc, new_base, t, orig_type, |
b7488229 | 1931 | f == TYPE_FIELDS (record_type)); |
d9745cea | 1932 | if (ret) |
1933 | return ret; | |
e60a6f7b | 1934 | ret = maybe_fold_offset_to_component_ref (loc, field_type, new_base, t, |
3d8f99df | 1935 | orig_type); |
d9745cea | 1936 | if (ret) |
1937 | return ret; | |
4ee9c684 | 1938 | } |
1939 | ||
1940 | if (!tail_array_field) | |
1941 | return NULL_TREE; | |
1942 | ||
1943 | f = tail_array_field; | |
1944 | field_type = TREE_TYPE (f); | |
115073ff | 1945 | offset = int_const_binop (MINUS_EXPR, offset, byte_position (f), 1); |
4ee9c684 | 1946 | |
4ee9c684 | 1947 | /* If we get here, we've got an aggregate field, and a possibly |
365db11e | 1948 | nonzero offset into them. Recurse and hope for a valid match. */ |
40b19772 | 1949 | base = build3 (COMPONENT_REF, field_type, base, f, NULL_TREE); |
e60a6f7b | 1950 | SET_EXPR_LOCATION (base, loc); |
4ee9c684 | 1951 | |
e60a6f7b | 1952 | t = maybe_fold_offset_to_array_ref (loc, base, offset, orig_type, |
b7488229 | 1953 | f == TYPE_FIELDS (record_type)); |
4ee9c684 | 1954 | if (t) |
1955 | return t; | |
e60a6f7b | 1956 | return maybe_fold_offset_to_component_ref (loc, field_type, base, offset, |
3d8f99df | 1957 | orig_type); |
4ee9c684 | 1958 | } |
1959 | ||
3b45913d | 1960 | /* Attempt to express (ORIG_TYPE)BASE+OFFSET as BASE->field_of_orig_type |
e60a6f7b | 1961 | or BASE[index] or by combination of those. |
1962 | ||
1963 | LOC is the location of original expression. | |
3b45913d | 1964 | |
1965 | Before attempting the conversion strip off existing ADDR_EXPRs and | |
1966 | handled component refs. */ | |
1967 | ||
1968 | tree | |
e60a6f7b | 1969 | maybe_fold_offset_to_reference (location_t loc, tree base, tree offset, |
1970 | tree orig_type) | |
3b45913d | 1971 | { |
1972 | tree ret; | |
1973 | tree type; | |
3b45913d | 1974 | |
1975 | STRIP_NOPS (base); | |
3d8f99df | 1976 | if (TREE_CODE (base) != ADDR_EXPR) |
1977 | return NULL_TREE; | |
3b45913d | 1978 | |
3d8f99df | 1979 | base = TREE_OPERAND (base, 0); |
3b45913d | 1980 | |
3d8f99df | 1981 | /* Handle case where existing COMPONENT_REF pick e.g. wrong field of union, |
1982 | so it needs to be removed and new COMPONENT_REF constructed. | |
1983 | The wrong COMPONENT_REF are often constructed by folding the | |
1984 | (type *)&object within the expression (type *)&object+offset */ | |
1985 | if (handled_component_p (base)) | |
3b45913d | 1986 | { |
3d8f99df | 1987 | HOST_WIDE_INT sub_offset, size, maxsize; |
1988 | tree newbase; | |
1989 | newbase = get_ref_base_and_extent (base, &sub_offset, | |
1990 | &size, &maxsize); | |
1991 | gcc_assert (newbase); | |
1992 | if (size == maxsize | |
1993 | && size != -1 | |
1994 | && !(sub_offset & (BITS_PER_UNIT - 1))) | |
e60a6f7b | 1995 | { |
3d8f99df | 1996 | base = newbase; |
1997 | if (sub_offset) | |
1998 | offset = int_const_binop (PLUS_EXPR, offset, | |
1999 | build_int_cst (TREE_TYPE (offset), | |
2000 | sub_offset / BITS_PER_UNIT), 1); | |
e60a6f7b | 2001 | } |
3b45913d | 2002 | } |
3d8f99df | 2003 | if (useless_type_conversion_p (orig_type, TREE_TYPE (base)) |
2004 | && integer_zerop (offset)) | |
2005 | return base; | |
2006 | type = TREE_TYPE (base); | |
2007 | ||
2008 | ret = maybe_fold_offset_to_component_ref (loc, type, base, offset, orig_type); | |
2009 | if (!ret) | |
2010 | ret = maybe_fold_offset_to_array_ref (loc, base, offset, orig_type, true); | |
2011 | ||
3b45913d | 2012 | return ret; |
2013 | } | |
41511585 | 2014 | |
5768aeb3 | 2015 | /* Attempt to express (ORIG_TYPE)&BASE+OFFSET as &BASE->field_of_orig_type |
2016 | or &BASE[index] or by combination of those. | |
2017 | ||
e60a6f7b | 2018 | LOC is the location of the original expression. |
2019 | ||
5768aeb3 | 2020 | Before attempting the conversion strip off existing component refs. */ |
2021 | ||
2022 | tree | |
e60a6f7b | 2023 | maybe_fold_offset_to_address (location_t loc, tree addr, tree offset, |
2024 | tree orig_type) | |
5768aeb3 | 2025 | { |
2026 | tree t; | |
2027 | ||
2028 | gcc_assert (POINTER_TYPE_P (TREE_TYPE (addr)) | |
2029 | && POINTER_TYPE_P (orig_type)); | |
2030 | ||
e60a6f7b | 2031 | t = maybe_fold_offset_to_reference (loc, addr, offset, |
2032 | TREE_TYPE (orig_type)); | |
5768aeb3 | 2033 | if (t != NULL_TREE) |
2034 | { | |
2035 | tree orig = addr; | |
2036 | tree ptr_type; | |
2037 | ||
2038 | /* For __builtin_object_size to function correctly we need to | |
2039 | make sure not to fold address arithmetic so that we change | |
2040 | reference from one array to another. This would happen for | |
2041 | example for | |
2042 | ||
2043 | struct X { char s1[10]; char s2[10] } s; | |
2044 | char *foo (void) { return &s.s2[-4]; } | |
2045 | ||
2046 | where we need to avoid generating &s.s1[6]. As the C and | |
2047 | C++ frontends create different initial trees | |
2048 | (char *) &s.s1 + -4 vs. &s.s1[-4] we have to do some | |
2049 | sophisticated comparisons here. Note that checking for the | |
2050 | condition after the fact is easier than trying to avoid doing | |
2051 | the folding. */ | |
2052 | STRIP_NOPS (orig); | |
2053 | if (TREE_CODE (orig) == ADDR_EXPR) | |
2054 | orig = TREE_OPERAND (orig, 0); | |
2055 | if ((TREE_CODE (orig) == ARRAY_REF | |
2056 | || (TREE_CODE (orig) == COMPONENT_REF | |
2057 | && TREE_CODE (TREE_TYPE (TREE_OPERAND (orig, 1))) == ARRAY_TYPE)) | |
2058 | && (TREE_CODE (t) == ARRAY_REF | |
bc79a76b | 2059 | || TREE_CODE (t) == COMPONENT_REF) |
5768aeb3 | 2060 | && !operand_equal_p (TREE_CODE (orig) == ARRAY_REF |
2061 | ? TREE_OPERAND (orig, 0) : orig, | |
2062 | TREE_CODE (t) == ARRAY_REF | |
2063 | ? TREE_OPERAND (t, 0) : t, 0)) | |
2064 | return NULL_TREE; | |
2065 | ||
2066 | ptr_type = build_pointer_type (TREE_TYPE (t)); | |
2067 | if (!useless_type_conversion_p (orig_type, ptr_type)) | |
2068 | return NULL_TREE; | |
389dd41b | 2069 | return build_fold_addr_expr_with_type_loc (loc, t, ptr_type); |
5768aeb3 | 2070 | } |
2071 | ||
2072 | return NULL_TREE; | |
2073 | } | |
2074 | ||
304557cd | 2075 | /* A subroutine of fold_stmt. Attempt to simplify *(BASE+OFFSET). |
4ee9c684 | 2076 | Return the simplified expression, or NULL if nothing could be done. */ |
2077 | ||
2078 | static tree | |
2079 | maybe_fold_stmt_indirect (tree expr, tree base, tree offset) | |
2080 | { | |
2081 | tree t; | |
5acf8305 | 2082 | bool volatile_p = TREE_THIS_VOLATILE (expr); |
e60a6f7b | 2083 | location_t loc = EXPR_LOCATION (expr); |
4ee9c684 | 2084 | |
2085 | /* We may well have constructed a double-nested PLUS_EXPR via multiple | |
2086 | substitutions. Fold that down to one. Remove NON_LVALUE_EXPRs that | |
2087 | are sometimes added. */ | |
2088 | base = fold (base); | |
40bcfc86 | 2089 | STRIP_TYPE_NOPS (base); |
4ee9c684 | 2090 | TREE_OPERAND (expr, 0) = base; |
2091 | ||
2092 | /* One possibility is that the address reduces to a string constant. */ | |
2093 | t = fold_read_from_constant_string (expr); | |
2094 | if (t) | |
2095 | return t; | |
2096 | ||
0de36bdb | 2097 | /* Add in any offset from a POINTER_PLUS_EXPR. */ |
2098 | if (TREE_CODE (base) == POINTER_PLUS_EXPR) | |
4ee9c684 | 2099 | { |
2100 | tree offset2; | |
2101 | ||
2102 | offset2 = TREE_OPERAND (base, 1); | |
2103 | if (TREE_CODE (offset2) != INTEGER_CST) | |
2104 | return NULL_TREE; | |
2105 | base = TREE_OPERAND (base, 0); | |
2106 | ||
0de36bdb | 2107 | offset = fold_convert (sizetype, |
2108 | int_const_binop (PLUS_EXPR, offset, offset2, 1)); | |
4ee9c684 | 2109 | } |
2110 | ||
2111 | if (TREE_CODE (base) == ADDR_EXPR) | |
2112 | { | |
3b45913d | 2113 | tree base_addr = base; |
2114 | ||
4ee9c684 | 2115 | /* Strip the ADDR_EXPR. */ |
2116 | base = TREE_OPERAND (base, 0); | |
2117 | ||
e67e5e1f | 2118 | /* Fold away CONST_DECL to its value, if the type is scalar. */ |
2119 | if (TREE_CODE (base) == CONST_DECL | |
0a685b29 | 2120 | && is_gimple_min_invariant (DECL_INITIAL (base))) |
e67e5e1f | 2121 | return DECL_INITIAL (base); |
2122 | ||
4ee9c684 | 2123 | /* Try folding *(&B+O) to B.X. */ |
e60a6f7b | 2124 | t = maybe_fold_offset_to_reference (loc, base_addr, offset, |
3b45913d | 2125 | TREE_TYPE (expr)); |
4ee9c684 | 2126 | if (t) |
5acf8305 | 2127 | { |
bcc7452f | 2128 | /* Preserve volatileness of the original expression. |
2129 | We can end up with a plain decl here which is shared | |
2130 | and we shouldn't mess with its flags. */ | |
2131 | if (!SSA_VAR_P (t)) | |
2132 | TREE_THIS_VOLATILE (t) = volatile_p; | |
5acf8305 | 2133 | return t; |
2134 | } | |
4ee9c684 | 2135 | } |
2136 | else | |
2137 | { | |
2138 | /* We can get here for out-of-range string constant accesses, | |
2139 | such as "_"[3]. Bail out of the entire substitution search | |
2140 | and arrange for the entire statement to be replaced by a | |
06b27565 | 2141 | call to __builtin_trap. In all likelihood this will all be |
4ee9c684 | 2142 | constant-folded away, but in the meantime we can't leave with |
2143 | something that get_expr_operands can't understand. */ | |
2144 | ||
2145 | t = base; | |
2146 | STRIP_NOPS (t); | |
2147 | if (TREE_CODE (t) == ADDR_EXPR | |
2148 | && TREE_CODE (TREE_OPERAND (t, 0)) == STRING_CST) | |
2149 | { | |
2150 | /* FIXME: Except that this causes problems elsewhere with dead | |
1fa3a8f6 | 2151 | code not being deleted, and we die in the rtl expanders |
4ee9c684 | 2152 | because we failed to remove some ssa_name. In the meantime, |
2153 | just return zero. */ | |
2154 | /* FIXME2: This condition should be signaled by | |
2155 | fold_read_from_constant_string directly, rather than | |
2156 | re-checking for it here. */ | |
2157 | return integer_zero_node; | |
2158 | } | |
2159 | ||
2160 | /* Try folding *(B+O) to B->X. Still an improvement. */ | |
2161 | if (POINTER_TYPE_P (TREE_TYPE (base))) | |
2162 | { | |
e60a6f7b | 2163 | t = maybe_fold_offset_to_reference (loc, base, offset, |
3b45913d | 2164 | TREE_TYPE (expr)); |
4ee9c684 | 2165 | if (t) |
2166 | return t; | |
2167 | } | |
2168 | } | |
2169 | ||
2170 | /* Otherwise we had an offset that we could not simplify. */ | |
2171 | return NULL_TREE; | |
2172 | } | |
2173 | ||
41511585 | 2174 | |
75a70cf9 | 2175 | /* A quaint feature extant in our address arithmetic is that there |
4ee9c684 | 2176 | can be hidden type changes here. The type of the result need |
2177 | not be the same as the type of the input pointer. | |
2178 | ||
2179 | What we're after here is an expression of the form | |
2180 | (T *)(&array + const) | |
75a70cf9 | 2181 | where array is OP0, const is OP1, RES_TYPE is T and |
2182 | the cast doesn't actually exist, but is implicit in the | |
0de36bdb | 2183 | type of the POINTER_PLUS_EXPR. We'd like to turn this into |
4ee9c684 | 2184 | &array[x] |
2185 | which may be able to propagate further. */ | |
2186 | ||
75a70cf9 | 2187 | tree |
e60a6f7b | 2188 | maybe_fold_stmt_addition (location_t loc, tree res_type, tree op0, tree op1) |
4ee9c684 | 2189 | { |
4ee9c684 | 2190 | tree ptd_type; |
2191 | tree t; | |
4ee9c684 | 2192 | |
4ee9c684 | 2193 | /* The first operand should be an ADDR_EXPR. */ |
2194 | if (TREE_CODE (op0) != ADDR_EXPR) | |
2195 | return NULL_TREE; | |
2196 | op0 = TREE_OPERAND (op0, 0); | |
2197 | ||
87c5de3b | 2198 | /* It had better be a constant. */ |
2199 | if (TREE_CODE (op1) != INTEGER_CST) | |
2200 | { | |
2201 | /* Or op0 should now be A[0] and the non-constant offset defined | |
2202 | via a multiplication by the array element size. */ | |
2203 | if (TREE_CODE (op0) == ARRAY_REF | |
2204 | && integer_zerop (TREE_OPERAND (op0, 1)) | |
2205 | && TREE_CODE (op1) == SSA_NAME | |
2206 | && host_integerp (TYPE_SIZE_UNIT (TREE_TYPE (op0)), 1)) | |
2207 | { | |
2208 | gimple offset_def = SSA_NAME_DEF_STMT (op1); | |
2209 | if (!is_gimple_assign (offset_def)) | |
2210 | return NULL_TREE; | |
2211 | ||
2212 | if (gimple_assign_rhs_code (offset_def) == MULT_EXPR | |
2213 | && TREE_CODE (gimple_assign_rhs2 (offset_def)) == INTEGER_CST | |
2214 | && tree_int_cst_equal (gimple_assign_rhs2 (offset_def), | |
2215 | TYPE_SIZE_UNIT (TREE_TYPE (op0)))) | |
aab01f66 | 2216 | return build_fold_addr_expr |
2217 | (build4 (ARRAY_REF, TREE_TYPE (op0), | |
87c5de3b | 2218 | TREE_OPERAND (op0, 0), |
2219 | gimple_assign_rhs1 (offset_def), | |
2220 | TREE_OPERAND (op0, 2), | |
2221 | TREE_OPERAND (op0, 3))); | |
2222 | else if (integer_onep (TYPE_SIZE_UNIT (TREE_TYPE (op0))) | |
2223 | && gimple_assign_rhs_code (offset_def) != MULT_EXPR) | |
aab01f66 | 2224 | return build_fold_addr_expr |
2225 | (build4 (ARRAY_REF, TREE_TYPE (op0), | |
87c5de3b | 2226 | TREE_OPERAND (op0, 0), |
2227 | op1, | |
2228 | TREE_OPERAND (op0, 2), | |
2229 | TREE_OPERAND (op0, 3))); | |
2230 | } | |
2231 | return NULL_TREE; | |
2232 | } | |
2233 | ||
4ee9c684 | 2234 | /* If the first operand is an ARRAY_REF, expand it so that we can fold |
2235 | the offset into it. */ | |
2236 | while (TREE_CODE (op0) == ARRAY_REF) | |
2237 | { | |
2238 | tree array_obj = TREE_OPERAND (op0, 0); | |
2239 | tree array_idx = TREE_OPERAND (op0, 1); | |
2240 | tree elt_type = TREE_TYPE (op0); | |
2241 | tree elt_size = TYPE_SIZE_UNIT (elt_type); | |
2242 | tree min_idx; | |
2243 | ||
2244 | if (TREE_CODE (array_idx) != INTEGER_CST) | |
2245 | break; | |
2246 | if (TREE_CODE (elt_size) != INTEGER_CST) | |
2247 | break; | |
2248 | ||
2249 | /* Un-bias the index by the min index of the array type. */ | |
2250 | min_idx = TYPE_DOMAIN (TREE_TYPE (array_obj)); | |
2251 | if (min_idx) | |
2252 | { | |
2253 | min_idx = TYPE_MIN_VALUE (min_idx); | |
2254 | if (min_idx) | |
2255 | { | |
6374121b | 2256 | if (TREE_CODE (min_idx) != INTEGER_CST) |
2257 | break; | |
2258 | ||
535664e3 | 2259 | array_idx = fold_convert (TREE_TYPE (min_idx), array_idx); |
4ee9c684 | 2260 | if (!integer_zerop (min_idx)) |
2261 | array_idx = int_const_binop (MINUS_EXPR, array_idx, | |
2262 | min_idx, 0); | |
2263 | } | |
2264 | } | |
2265 | ||
2266 | /* Convert the index to a byte offset. */ | |
535664e3 | 2267 | array_idx = fold_convert (sizetype, array_idx); |
4ee9c684 | 2268 | array_idx = int_const_binop (MULT_EXPR, array_idx, elt_size, 0); |
2269 | ||
2270 | /* Update the operands for the next round, or for folding. */ | |
0de36bdb | 2271 | op1 = int_const_binop (PLUS_EXPR, |
4ee9c684 | 2272 | array_idx, op1, 0); |
4ee9c684 | 2273 | op0 = array_obj; |
2274 | } | |
2275 | ||
75a70cf9 | 2276 | ptd_type = TREE_TYPE (res_type); |
0b4a6afc | 2277 | /* If we want a pointer to void, reconstruct the reference from the |
2278 | array element type. A pointer to that can be trivially converted | |
2279 | to void *. This happens as we fold (void *)(ptr p+ off). */ | |
2280 | if (VOID_TYPE_P (ptd_type) | |
2281 | && TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE) | |
2282 | ptd_type = TREE_TYPE (TREE_TYPE (op0)); | |
4ee9c684 | 2283 | |
2284 | /* At which point we can try some of the same things as for indirects. */ | |
e60a6f7b | 2285 | t = maybe_fold_offset_to_array_ref (loc, op0, op1, ptd_type, true); |
4ee9c684 | 2286 | if (!t) |
e60a6f7b | 2287 | t = maybe_fold_offset_to_component_ref (loc, TREE_TYPE (op0), op0, op1, |
3d8f99df | 2288 | ptd_type); |
4ee9c684 | 2289 | if (t) |
e60a6f7b | 2290 | { |
2291 | t = build1 (ADDR_EXPR, res_type, t); | |
2292 | SET_EXPR_LOCATION (t, loc); | |
2293 | } | |
4ee9c684 | 2294 | |
2295 | return t; | |
2296 | } | |
2297 | ||
304557cd | 2298 | /* Subroutine of fold_stmt. We perform several simplifications of the |
2299 | memory reference tree EXPR and make sure to re-gimplify them properly | |
2300 | after propagation of constant addresses. IS_LHS is true if the | |
2301 | reference is supposed to be an lvalue. */ | |
4ee9c684 | 2302 | |
2303 | static tree | |
304557cd | 2304 | maybe_fold_reference (tree expr, bool is_lhs) |
4ee9c684 | 2305 | { |
304557cd | 2306 | tree *t = &expr; |
4ee9c684 | 2307 | |
304557cd | 2308 | if (TREE_CODE (expr) == ARRAY_REF |
2309 | && !is_lhs) | |
2310 | { | |
2311 | tree tem = fold_read_from_constant_string (expr); | |
2312 | if (tem) | |
2313 | return tem; | |
2314 | } | |
75a70cf9 | 2315 | |
304557cd | 2316 | /* ??? We might want to open-code the relevant remaining cases |
2317 | to avoid using the generic fold. */ | |
2318 | if (handled_component_p (*t) | |
2319 | && CONSTANT_CLASS_P (TREE_OPERAND (*t, 0))) | |
4ee9c684 | 2320 | { |
304557cd | 2321 | tree tem = fold (*t); |
2322 | if (tem != *t) | |
2323 | return tem; | |
2324 | } | |
2325 | ||
2326 | while (handled_component_p (*t)) | |
2327 | t = &TREE_OPERAND (*t, 0); | |
4ee9c684 | 2328 | |
304557cd | 2329 | if (TREE_CODE (*t) == INDIRECT_REF) |
2330 | { | |
2331 | tree tem = maybe_fold_stmt_indirect (*t, TREE_OPERAND (*t, 0), | |
2332 | integer_zero_node); | |
4d444068 | 2333 | /* Avoid folding *"abc" = 5 into 'a' = 5. */ |
304557cd | 2334 | if (is_lhs && tem && CONSTANT_CLASS_P (tem)) |
2335 | tem = NULL_TREE; | |
2336 | if (!tem | |
2337 | && TREE_CODE (TREE_OPERAND (*t, 0)) == ADDR_EXPR) | |
8ac2d49b | 2338 | /* If we had a good reason for propagating the address here, |
2339 | make sure we end up with valid gimple. See PR34989. */ | |
304557cd | 2340 | tem = TREE_OPERAND (TREE_OPERAND (*t, 0), 0); |
4ee9c684 | 2341 | |
304557cd | 2342 | if (tem) |
2343 | { | |
2344 | *t = tem; | |
2345 | tem = maybe_fold_reference (expr, is_lhs); | |
2346 | if (tem) | |
2347 | return tem; | |
2348 | return expr; | |
2349 | } | |
4ee9c684 | 2350 | } |
cc8f0042 | 2351 | else if (!is_lhs |
2352 | && DECL_P (*t)) | |
2353 | { | |
2354 | tree tem = get_symbol_constant_value (*t); | |
2355 | if (tem) | |
2356 | { | |
2357 | *t = tem; | |
2358 | tem = maybe_fold_reference (expr, is_lhs); | |
2359 | if (tem) | |
2360 | return tem; | |
2361 | return expr; | |
2362 | } | |
2363 | } | |
4ee9c684 | 2364 | |
2365 | return NULL_TREE; | |
2366 | } | |
2367 | ||
304557cd | 2368 | |
0a39fd54 | 2369 | /* Return the string length, maximum string length or maximum value of |
2370 | ARG in LENGTH. | |
2371 | If ARG is an SSA name variable, follow its use-def chains. If LENGTH | |
2372 | is not NULL and, for TYPE == 0, its value is not equal to the length | |
2373 | we determine or if we are unable to determine the length or value, | |
2374 | return false. VISITED is a bitmap of visited variables. | |
2375 | TYPE is 0 if string length should be returned, 1 for maximum string | |
2376 | length and 2 for maximum value ARG can have. */ | |
4ee9c684 | 2377 | |
72648a0e | 2378 | static bool |
0a39fd54 | 2379 | get_maxval_strlen (tree arg, tree *length, bitmap visited, int type) |
4ee9c684 | 2380 | { |
75a70cf9 | 2381 | tree var, val; |
2382 | gimple def_stmt; | |
41511585 | 2383 | |
2384 | if (TREE_CODE (arg) != SSA_NAME) | |
72648a0e | 2385 | { |
ec0fa513 | 2386 | if (TREE_CODE (arg) == COND_EXPR) |
2387 | return get_maxval_strlen (COND_EXPR_THEN (arg), length, visited, type) | |
2388 | && get_maxval_strlen (COND_EXPR_ELSE (arg), length, visited, type); | |
0b4a6afc | 2389 | /* We can end up with &(*iftmp_1)[0] here as well, so handle it. */ |
2390 | else if (TREE_CODE (arg) == ADDR_EXPR | |
2391 | && TREE_CODE (TREE_OPERAND (arg, 0)) == ARRAY_REF | |
2392 | && integer_zerop (TREE_OPERAND (TREE_OPERAND (arg, 0), 1))) | |
2393 | { | |
2394 | tree aop0 = TREE_OPERAND (TREE_OPERAND (arg, 0), 0); | |
2395 | if (TREE_CODE (aop0) == INDIRECT_REF | |
2396 | && TREE_CODE (TREE_OPERAND (aop0, 0)) == SSA_NAME) | |
2397 | return get_maxval_strlen (TREE_OPERAND (aop0, 0), | |
2398 | length, visited, type); | |
2399 | } | |
ec0fa513 | 2400 | |
0a39fd54 | 2401 | if (type == 2) |
2402 | { | |
2403 | val = arg; | |
2404 | if (TREE_CODE (val) != INTEGER_CST | |
2405 | || tree_int_cst_sgn (val) < 0) | |
2406 | return false; | |
2407 | } | |
2408 | else | |
2409 | val = c_strlen (arg, 1); | |
41511585 | 2410 | if (!val) |
72648a0e | 2411 | return false; |
e37235f0 | 2412 | |
0a39fd54 | 2413 | if (*length) |
2414 | { | |
2415 | if (type > 0) | |
2416 | { | |
2417 | if (TREE_CODE (*length) != INTEGER_CST | |
2418 | || TREE_CODE (val) != INTEGER_CST) | |
2419 | return false; | |
2420 | ||
2421 | if (tree_int_cst_lt (*length, val)) | |
2422 | *length = val; | |
2423 | return true; | |
2424 | } | |
2425 | else if (simple_cst_equal (val, *length) != 1) | |
2426 | return false; | |
2427 | } | |
4ee9c684 | 2428 | |
41511585 | 2429 | *length = val; |
2430 | return true; | |
4ee9c684 | 2431 | } |
72648a0e | 2432 | |
41511585 | 2433 | /* If we were already here, break the infinite cycle. */ |
2434 | if (bitmap_bit_p (visited, SSA_NAME_VERSION (arg))) | |
2435 | return true; | |
2436 | bitmap_set_bit (visited, SSA_NAME_VERSION (arg)); | |
2437 | ||
2438 | var = arg; | |
2439 | def_stmt = SSA_NAME_DEF_STMT (var); | |
4ee9c684 | 2440 | |
75a70cf9 | 2441 | switch (gimple_code (def_stmt)) |
2442 | { | |
2443 | case GIMPLE_ASSIGN: | |
2444 | /* The RHS of the statement defining VAR must either have a | |
2445 | constant length or come from another SSA_NAME with a constant | |
2446 | length. */ | |
2447 | if (gimple_assign_single_p (def_stmt) | |
2448 | || gimple_assign_unary_nop_p (def_stmt)) | |
2449 | { | |
2450 | tree rhs = gimple_assign_rhs1 (def_stmt); | |
2451 | return get_maxval_strlen (rhs, length, visited, type); | |
2452 | } | |
2453 | return false; | |
2454 | ||
2455 | case GIMPLE_PHI: | |
41511585 | 2456 | { |
2457 | /* All the arguments of the PHI node must have the same constant | |
2458 | length. */ | |
75a70cf9 | 2459 | unsigned i; |
2460 | ||
2461 | for (i = 0; i < gimple_phi_num_args (def_stmt); i++) | |
2462 | { | |
2463 | tree arg = gimple_phi_arg (def_stmt, i)->def; | |
2464 | ||
2465 | /* If this PHI has itself as an argument, we cannot | |
2466 | determine the string length of this argument. However, | |
2467 | if we can find a constant string length for the other | |
2468 | PHI args then we can still be sure that this is a | |
2469 | constant string length. So be optimistic and just | |
2470 | continue with the next argument. */ | |
2471 | if (arg == gimple_phi_result (def_stmt)) | |
2472 | continue; | |
2473 | ||
2474 | if (!get_maxval_strlen (arg, length, visited, type)) | |
2475 | return false; | |
2476 | } | |
2477 | } | |
2478 | return true; | |
4ee9c684 | 2479 | |
41511585 | 2480 | default: |
75a70cf9 | 2481 | return false; |
4ee9c684 | 2482 | } |
4ee9c684 | 2483 | } |
2484 | ||
2485 | ||
75a70cf9 | 2486 | /* Fold builtin call in statement STMT. Returns a simplified tree. |
2487 | We may return a non-constant expression, including another call | |
2488 | to a different function and with different arguments, e.g., | |
2489 | substituting memcpy for strcpy when the string length is known. | |
2490 | Note that some builtins expand into inline code that may not | |
2491 | be valid in GIMPLE. Callers must take care. */ | |
4ee9c684 | 2492 | |
2493 | static tree | |
75a70cf9 | 2494 | ccp_fold_builtin (gimple stmt) |
4ee9c684 | 2495 | { |
0a39fd54 | 2496 | tree result, val[3]; |
c2f47e15 | 2497 | tree callee, a; |
be9f921e | 2498 | int arg_idx, type; |
f0613857 | 2499 | bitmap visited; |
2500 | bool ignore; | |
c2f47e15 | 2501 | int nargs; |
389dd41b | 2502 | location_t loc = gimple_location (stmt); |
4ee9c684 | 2503 | |
75a70cf9 | 2504 | gcc_assert (is_gimple_call (stmt)); |
2505 | ||
2506 | ignore = (gimple_call_lhs (stmt) == NULL); | |
4ee9c684 | 2507 | |
2508 | /* First try the generic builtin folder. If that succeeds, return the | |
2509 | result directly. */ | |
75a70cf9 | 2510 | result = fold_call_stmt (stmt, ignore); |
4ee9c684 | 2511 | if (result) |
0a39fd54 | 2512 | { |
2513 | if (ignore) | |
2514 | STRIP_NOPS (result); | |
2515 | return result; | |
2516 | } | |
f0613857 | 2517 | |
2518 | /* Ignore MD builtins. */ | |
75a70cf9 | 2519 | callee = gimple_call_fndecl (stmt); |
f0613857 | 2520 | if (DECL_BUILT_IN_CLASS (callee) == BUILT_IN_MD) |
2521 | return NULL_TREE; | |
4ee9c684 | 2522 | |
2523 | /* If the builtin could not be folded, and it has no argument list, | |
2524 | we're done. */ | |
75a70cf9 | 2525 | nargs = gimple_call_num_args (stmt); |
c2f47e15 | 2526 | if (nargs == 0) |
4ee9c684 | 2527 | return NULL_TREE; |
2528 | ||
2529 | /* Limit the work only for builtins we know how to simplify. */ | |
2530 | switch (DECL_FUNCTION_CODE (callee)) | |
2531 | { | |
2532 | case BUILT_IN_STRLEN: | |
2533 | case BUILT_IN_FPUTS: | |
2534 | case BUILT_IN_FPUTS_UNLOCKED: | |
be9f921e | 2535 | arg_idx = 0; |
0a39fd54 | 2536 | type = 0; |
4ee9c684 | 2537 | break; |
2538 | case BUILT_IN_STRCPY: | |
2539 | case BUILT_IN_STRNCPY: | |
be9f921e | 2540 | arg_idx = 1; |
0a39fd54 | 2541 | type = 0; |
2542 | break; | |
2543 | case BUILT_IN_MEMCPY_CHK: | |
2544 | case BUILT_IN_MEMPCPY_CHK: | |
2545 | case BUILT_IN_MEMMOVE_CHK: | |
2546 | case BUILT_IN_MEMSET_CHK: | |
2547 | case BUILT_IN_STRNCPY_CHK: | |
be9f921e | 2548 | arg_idx = 2; |
0a39fd54 | 2549 | type = 2; |
2550 | break; | |
2551 | case BUILT_IN_STRCPY_CHK: | |
2552 | case BUILT_IN_STPCPY_CHK: | |
be9f921e | 2553 | arg_idx = 1; |
0a39fd54 | 2554 | type = 1; |
2555 | break; | |
2556 | case BUILT_IN_SNPRINTF_CHK: | |
2557 | case BUILT_IN_VSNPRINTF_CHK: | |
be9f921e | 2558 | arg_idx = 1; |
0a39fd54 | 2559 | type = 2; |
4ee9c684 | 2560 | break; |
2561 | default: | |
2562 | return NULL_TREE; | |
2563 | } | |
2564 | ||
54807c88 | 2565 | if (arg_idx >= nargs) |
2566 | return NULL_TREE; | |
2567 | ||
4ee9c684 | 2568 | /* Try to use the dataflow information gathered by the CCP process. */ |
27335ffd | 2569 | visited = BITMAP_ALLOC (NULL); |
be9f921e | 2570 | bitmap_clear (visited); |
4ee9c684 | 2571 | |
0a39fd54 | 2572 | memset (val, 0, sizeof (val)); |
be9f921e | 2573 | a = gimple_call_arg (stmt, arg_idx); |
2574 | if (!get_maxval_strlen (a, &val[arg_idx], visited, type)) | |
2575 | val[arg_idx] = NULL_TREE; | |
4ee9c684 | 2576 | |
27335ffd | 2577 | BITMAP_FREE (visited); |
4ee9c684 | 2578 | |
f0613857 | 2579 | result = NULL_TREE; |
4ee9c684 | 2580 | switch (DECL_FUNCTION_CODE (callee)) |
2581 | { | |
2582 | case BUILT_IN_STRLEN: | |
54807c88 | 2583 | if (val[0] && nargs == 1) |
4ee9c684 | 2584 | { |
75a70cf9 | 2585 | tree new_val = |
2586 | fold_convert (TREE_TYPE (gimple_call_lhs (stmt)), val[0]); | |
4ee9c684 | 2587 | |
2588 | /* If the result is not a valid gimple value, or not a cast | |
2589 | of a valid gimple value, then we can not use the result. */ | |
f0d6e81c | 2590 | if (is_gimple_val (new_val) |
2591 | || (is_gimple_cast (new_val) | |
2592 | && is_gimple_val (TREE_OPERAND (new_val, 0)))) | |
2593 | return new_val; | |
4ee9c684 | 2594 | } |
f0613857 | 2595 | break; |
2596 | ||
4ee9c684 | 2597 | case BUILT_IN_STRCPY: |
c2f47e15 | 2598 | if (val[1] && is_gimple_val (val[1]) && nargs == 2) |
389dd41b | 2599 | result = fold_builtin_strcpy (loc, callee, |
75a70cf9 | 2600 | gimple_call_arg (stmt, 0), |
2601 | gimple_call_arg (stmt, 1), | |
c2f47e15 | 2602 | val[1]); |
f0613857 | 2603 | break; |
2604 | ||
4ee9c684 | 2605 | case BUILT_IN_STRNCPY: |
c2f47e15 | 2606 | if (val[1] && is_gimple_val (val[1]) && nargs == 3) |
389dd41b | 2607 | result = fold_builtin_strncpy (loc, callee, |
75a70cf9 | 2608 | gimple_call_arg (stmt, 0), |
2609 | gimple_call_arg (stmt, 1), | |
2610 | gimple_call_arg (stmt, 2), | |
c2f47e15 | 2611 | val[1]); |
f0613857 | 2612 | break; |
2613 | ||
4ee9c684 | 2614 | case BUILT_IN_FPUTS: |
54807c88 | 2615 | if (nargs == 2) |
389dd41b | 2616 | result = fold_builtin_fputs (loc, gimple_call_arg (stmt, 0), |
54807c88 | 2617 | gimple_call_arg (stmt, 1), |
2618 | ignore, false, val[0]); | |
f0613857 | 2619 | break; |
2620 | ||
4ee9c684 | 2621 | case BUILT_IN_FPUTS_UNLOCKED: |
54807c88 | 2622 | if (nargs == 2) |
389dd41b | 2623 | result = fold_builtin_fputs (loc, gimple_call_arg (stmt, 0), |
54807c88 | 2624 | gimple_call_arg (stmt, 1), |
2625 | ignore, true, val[0]); | |
0a39fd54 | 2626 | break; |
2627 | ||
2628 | case BUILT_IN_MEMCPY_CHK: | |
2629 | case BUILT_IN_MEMPCPY_CHK: | |
2630 | case BUILT_IN_MEMMOVE_CHK: | |
2631 | case BUILT_IN_MEMSET_CHK: | |
54807c88 | 2632 | if (val[2] && is_gimple_val (val[2]) && nargs == 4) |
389dd41b | 2633 | result = fold_builtin_memory_chk (loc, callee, |
75a70cf9 | 2634 | gimple_call_arg (stmt, 0), |
2635 | gimple_call_arg (stmt, 1), | |
2636 | gimple_call_arg (stmt, 2), | |
2637 | gimple_call_arg (stmt, 3), | |
c2f47e15 | 2638 | val[2], ignore, |
0a39fd54 | 2639 | DECL_FUNCTION_CODE (callee)); |
2640 | break; | |
2641 | ||
2642 | case BUILT_IN_STRCPY_CHK: | |
2643 | case BUILT_IN_STPCPY_CHK: | |
54807c88 | 2644 | if (val[1] && is_gimple_val (val[1]) && nargs == 3) |
389dd41b | 2645 | result = fold_builtin_stxcpy_chk (loc, callee, |
75a70cf9 | 2646 | gimple_call_arg (stmt, 0), |
2647 | gimple_call_arg (stmt, 1), | |
2648 | gimple_call_arg (stmt, 2), | |
c2f47e15 | 2649 | val[1], ignore, |
0a39fd54 | 2650 | DECL_FUNCTION_CODE (callee)); |
2651 | break; | |
2652 | ||
2653 | case BUILT_IN_STRNCPY_CHK: | |
54807c88 | 2654 | if (val[2] && is_gimple_val (val[2]) && nargs == 4) |
389dd41b | 2655 | result = fold_builtin_strncpy_chk (loc, gimple_call_arg (stmt, 0), |
75a70cf9 | 2656 | gimple_call_arg (stmt, 1), |
2657 | gimple_call_arg (stmt, 2), | |
2658 | gimple_call_arg (stmt, 3), | |
c2f47e15 | 2659 | val[2]); |
0a39fd54 | 2660 | break; |
2661 | ||
2662 | case BUILT_IN_SNPRINTF_CHK: | |
2663 | case BUILT_IN_VSNPRINTF_CHK: | |
2664 | if (val[1] && is_gimple_val (val[1])) | |
75a70cf9 | 2665 | result = gimple_fold_builtin_snprintf_chk (stmt, val[1], |
2666 | DECL_FUNCTION_CODE (callee)); | |
f0613857 | 2667 | break; |
4ee9c684 | 2668 | |
2669 | default: | |
8c0963c4 | 2670 | gcc_unreachable (); |
4ee9c684 | 2671 | } |
2672 | ||
f0613857 | 2673 | if (result && ignore) |
db97ad41 | 2674 | result = fold_ignored_result (result); |
f0613857 | 2675 | return result; |
4ee9c684 | 2676 | } |
2677 | ||
75a70cf9 | 2678 | /* Attempt to fold an assignment statement pointed-to by SI. Returns a |
2679 | replacement rhs for the statement or NULL_TREE if no simplification | |
2680 | could be made. It is assumed that the operands have been previously | |
2681 | folded. */ | |
2682 | ||
2683 | static tree | |
2684 | fold_gimple_assign (gimple_stmt_iterator *si) | |
2685 | { | |
2686 | gimple stmt = gsi_stmt (*si); | |
2687 | enum tree_code subcode = gimple_assign_rhs_code (stmt); | |
389dd41b | 2688 | location_t loc = gimple_location (stmt); |
75a70cf9 | 2689 | |
304557cd | 2690 | tree result = NULL_TREE; |
75a70cf9 | 2691 | |
2692 | switch (get_gimple_rhs_class (subcode)) | |
2693 | { | |
2694 | case GIMPLE_SINGLE_RHS: | |
2695 | { | |
2696 | tree rhs = gimple_assign_rhs1 (stmt); | |
304557cd | 2697 | |
75a70cf9 | 2698 | /* Try to fold a conditional expression. */ |
2699 | if (TREE_CODE (rhs) == COND_EXPR) | |
2700 | { | |
304557cd | 2701 | tree op0 = COND_EXPR_COND (rhs); |
2702 | tree tem; | |
2703 | bool set = false; | |
389dd41b | 2704 | location_t cond_loc = EXPR_LOCATION (rhs); |
304557cd | 2705 | |
2706 | if (COMPARISON_CLASS_P (op0)) | |
2707 | { | |
2708 | fold_defer_overflow_warnings (); | |
389dd41b | 2709 | tem = fold_binary_loc (cond_loc, |
2710 | TREE_CODE (op0), TREE_TYPE (op0), | |
304557cd | 2711 | TREE_OPERAND (op0, 0), |
2712 | TREE_OPERAND (op0, 1)); | |
2713 | /* This is actually a conditional expression, not a GIMPLE | |
2714 | conditional statement, however, the valid_gimple_rhs_p | |
2715 | test still applies. */ | |
2716 | set = (tem && is_gimple_condexpr (tem) | |
2717 | && valid_gimple_rhs_p (tem)); | |
2718 | fold_undefer_overflow_warnings (set, stmt, 0); | |
2719 | } | |
2720 | else if (is_gimple_min_invariant (op0)) | |
2721 | { | |
2722 | tem = op0; | |
2723 | set = true; | |
2724 | } | |
2725 | else | |
2726 | return NULL_TREE; | |
2727 | ||
2728 | if (set) | |
389dd41b | 2729 | result = fold_build3_loc (cond_loc, COND_EXPR, TREE_TYPE (rhs), tem, |
304557cd | 2730 | COND_EXPR_THEN (rhs), COND_EXPR_ELSE (rhs)); |
75a70cf9 | 2731 | } |
2732 | ||
304557cd | 2733 | else if (TREE_CODE (rhs) == TARGET_MEM_REF) |
2734 | return maybe_fold_tmr (rhs); | |
2735 | ||
2736 | else if (REFERENCE_CLASS_P (rhs)) | |
2737 | return maybe_fold_reference (rhs, false); | |
2738 | ||
2739 | else if (TREE_CODE (rhs) == ADDR_EXPR) | |
2740 | { | |
2741 | tree tem = maybe_fold_reference (TREE_OPERAND (rhs, 0), true); | |
2742 | if (tem) | |
2743 | result = fold_convert (TREE_TYPE (rhs), | |
389dd41b | 2744 | build_fold_addr_expr_loc (loc, tem)); |
304557cd | 2745 | } |
2746 | ||
388a0bc7 | 2747 | else if (TREE_CODE (rhs) == CONSTRUCTOR |
2748 | && TREE_CODE (TREE_TYPE (rhs)) == VECTOR_TYPE | |
2749 | && (CONSTRUCTOR_NELTS (rhs) | |
2750 | == TYPE_VECTOR_SUBPARTS (TREE_TYPE (rhs)))) | |
2751 | { | |
2752 | /* Fold a constant vector CONSTRUCTOR to VECTOR_CST. */ | |
2753 | unsigned i; | |
2754 | tree val; | |
2755 | ||
2756 | FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (rhs), i, val) | |
2757 | if (TREE_CODE (val) != INTEGER_CST | |
2758 | && TREE_CODE (val) != REAL_CST | |
2759 | && TREE_CODE (val) != FIXED_CST) | |
2760 | return NULL_TREE; | |
2761 | ||
2762 | return build_vector_from_ctor (TREE_TYPE (rhs), | |
2763 | CONSTRUCTOR_ELTS (rhs)); | |
2764 | } | |
2765 | ||
cc8f0042 | 2766 | else if (DECL_P (rhs)) |
2767 | return get_symbol_constant_value (rhs); | |
2768 | ||
75a70cf9 | 2769 | /* If we couldn't fold the RHS, hand over to the generic |
2770 | fold routines. */ | |
2771 | if (result == NULL_TREE) | |
2772 | result = fold (rhs); | |
2773 | ||
2774 | /* Strip away useless type conversions. Both the NON_LVALUE_EXPR | |
2775 | that may have been added by fold, and "useless" type | |
2776 | conversions that might now be apparent due to propagation. */ | |
2777 | STRIP_USELESS_TYPE_CONVERSION (result); | |
2778 | ||
2779 | if (result != rhs && valid_gimple_rhs_p (result)) | |
2780 | return result; | |
304557cd | 2781 | |
2782 | return NULL_TREE; | |
75a70cf9 | 2783 | } |
2784 | break; | |
2785 | ||
2786 | case GIMPLE_UNARY_RHS: | |
f1fb2997 | 2787 | { |
2788 | tree rhs = gimple_assign_rhs1 (stmt); | |
75a70cf9 | 2789 | |
389dd41b | 2790 | result = fold_unary_loc (loc, subcode, gimple_expr_type (stmt), rhs); |
f1fb2997 | 2791 | if (result) |
2792 | { | |
2793 | /* If the operation was a conversion do _not_ mark a | |
2794 | resulting constant with TREE_OVERFLOW if the original | |
2795 | constant was not. These conversions have implementation | |
2796 | defined behavior and retaining the TREE_OVERFLOW flag | |
2797 | here would confuse later passes such as VRP. */ | |
2798 | if (CONVERT_EXPR_CODE_P (subcode) | |
2799 | && TREE_CODE (result) == INTEGER_CST | |
2800 | && TREE_CODE (rhs) == INTEGER_CST) | |
2801 | TREE_OVERFLOW (result) = TREE_OVERFLOW (rhs); | |
2802 | ||
2803 | STRIP_USELESS_TYPE_CONVERSION (result); | |
2804 | if (valid_gimple_rhs_p (result)) | |
2805 | return result; | |
2806 | } | |
2807 | else if (CONVERT_EXPR_CODE_P (subcode) | |
2808 | && POINTER_TYPE_P (gimple_expr_type (stmt)) | |
2809 | && POINTER_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (stmt)))) | |
2810 | { | |
2811 | tree type = gimple_expr_type (stmt); | |
389dd41b | 2812 | tree t = maybe_fold_offset_to_address (loc, |
e60a6f7b | 2813 | gimple_assign_rhs1 (stmt), |
f1fb2997 | 2814 | integer_zero_node, type); |
2815 | if (t) | |
2816 | return t; | |
2817 | } | |
2818 | } | |
75a70cf9 | 2819 | break; |
2820 | ||
2821 | case GIMPLE_BINARY_RHS: | |
2822 | /* Try to fold pointer addition. */ | |
2823 | if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR) | |
93f3673b | 2824 | { |
2825 | tree type = TREE_TYPE (gimple_assign_rhs1 (stmt)); | |
2826 | if (TREE_CODE (TREE_TYPE (type)) == ARRAY_TYPE) | |
2827 | { | |
2828 | type = build_pointer_type (TREE_TYPE (TREE_TYPE (type))); | |
2829 | if (!useless_type_conversion_p | |
2830 | (TREE_TYPE (gimple_assign_lhs (stmt)), type)) | |
2831 | type = TREE_TYPE (gimple_assign_rhs1 (stmt)); | |
2832 | } | |
e60a6f7b | 2833 | result = maybe_fold_stmt_addition (gimple_location (stmt), |
2834 | type, | |
93f3673b | 2835 | gimple_assign_rhs1 (stmt), |
2836 | gimple_assign_rhs2 (stmt)); | |
2837 | } | |
75a70cf9 | 2838 | |
2839 | if (!result) | |
389dd41b | 2840 | result = fold_binary_loc (loc, subcode, |
75a70cf9 | 2841 | TREE_TYPE (gimple_assign_lhs (stmt)), |
2842 | gimple_assign_rhs1 (stmt), | |
2843 | gimple_assign_rhs2 (stmt)); | |
2844 | ||
2845 | if (result) | |
2846 | { | |
2847 | STRIP_USELESS_TYPE_CONVERSION (result); | |
2848 | if (valid_gimple_rhs_p (result)) | |
2849 | return result; | |
ec3753d0 | 2850 | |
2851 | /* Fold might have produced non-GIMPLE, so if we trust it blindly | |
2852 | we lose canonicalization opportunities. Do not go again | |
2853 | through fold here though, or the same non-GIMPLE will be | |
2854 | produced. */ | |
2855 | if (commutative_tree_code (subcode) | |
2856 | && tree_swap_operands_p (gimple_assign_rhs1 (stmt), | |
2857 | gimple_assign_rhs2 (stmt), false)) | |
2858 | return build2 (subcode, TREE_TYPE (gimple_assign_lhs (stmt)), | |
2859 | gimple_assign_rhs2 (stmt), | |
2860 | gimple_assign_rhs1 (stmt)); | |
75a70cf9 | 2861 | } |
2862 | break; | |
2863 | ||
2864 | case GIMPLE_INVALID_RHS: | |
2865 | gcc_unreachable (); | |
2866 | } | |
2867 | ||
2868 | return NULL_TREE; | |
2869 | } | |
2870 | ||
2871 | /* Attempt to fold a conditional statement. Return true if any changes were | |
2872 | made. We only attempt to fold the condition expression, and do not perform | |
2873 | any transformation that would require alteration of the cfg. It is | |
2874 | assumed that the operands have been previously folded. */ | |
2875 | ||
2876 | static bool | |
2877 | fold_gimple_cond (gimple stmt) | |
2878 | { | |
389dd41b | 2879 | tree result = fold_binary_loc (gimple_location (stmt), |
2880 | gimple_cond_code (stmt), | |
75a70cf9 | 2881 | boolean_type_node, |
2882 | gimple_cond_lhs (stmt), | |
2883 | gimple_cond_rhs (stmt)); | |
2884 | ||
2885 | if (result) | |
2886 | { | |
2887 | STRIP_USELESS_TYPE_CONVERSION (result); | |
2888 | if (is_gimple_condexpr (result) && valid_gimple_rhs_p (result)) | |
2889 | { | |
2890 | gimple_cond_set_condition_from_tree (stmt, result); | |
2891 | return true; | |
2892 | } | |
2893 | } | |
2894 | ||
2895 | return false; | |
2896 | } | |
2897 | ||
2898 | ||
2899 | /* Attempt to fold a call statement referenced by the statement iterator GSI. | |
2900 | The statement may be replaced by another statement, e.g., if the call | |
2901 | simplifies to a constant value. Return true if any changes were made. | |
2902 | It is assumed that the operands have been previously folded. */ | |
2903 | ||
2904 | static bool | |
2905 | fold_gimple_call (gimple_stmt_iterator *gsi) | |
2906 | { | |
2907 | gimple stmt = gsi_stmt (*gsi); | |
2908 | ||
2909 | tree callee = gimple_call_fndecl (stmt); | |
2910 | ||
2911 | /* Check for builtins that CCP can handle using information not | |
2912 | available in the generic fold routines. */ | |
2913 | if (callee && DECL_BUILT_IN (callee)) | |
2914 | { | |
2915 | tree result = ccp_fold_builtin (stmt); | |
2916 | ||
2917 | if (result) | |
2918 | return update_call_from_tree (gsi, result); | |
2919 | } | |
2920 | else | |
2921 | { | |
2922 | /* Check for resolvable OBJ_TYPE_REF. The only sorts we can resolve | |
2923 | here are when we've propagated the address of a decl into the | |
2924 | object slot. */ | |
2925 | /* ??? Should perhaps do this in fold proper. However, doing it | |
2926 | there requires that we create a new CALL_EXPR, and that requires | |
2927 | copying EH region info to the new node. Easier to just do it | |
2928 | here where we can just smash the call operand. */ | |
2929 | /* ??? Is there a good reason not to do this in fold_stmt_inplace? */ | |
2930 | callee = gimple_call_fn (stmt); | |
2931 | if (TREE_CODE (callee) == OBJ_TYPE_REF | |
2932 | && lang_hooks.fold_obj_type_ref | |
2933 | && TREE_CODE (OBJ_TYPE_REF_OBJECT (callee)) == ADDR_EXPR | |
2934 | && DECL_P (TREE_OPERAND | |
2935 | (OBJ_TYPE_REF_OBJECT (callee), 0))) | |
2936 | { | |
2937 | tree t; | |
2938 | ||
2939 | /* ??? Caution: Broken ADDR_EXPR semantics means that | |
2940 | looking at the type of the operand of the addr_expr | |
2941 | can yield an array type. See silly exception in | |
2942 | check_pointer_types_r. */ | |
2943 | t = TREE_TYPE (TREE_TYPE (OBJ_TYPE_REF_OBJECT (callee))); | |
2944 | t = lang_hooks.fold_obj_type_ref (callee, t); | |
2945 | if (t) | |
2946 | { | |
2947 | gimple_call_set_fn (stmt, t); | |
2948 | return true; | |
2949 | } | |
2950 | } | |
2951 | } | |
2952 | ||
2953 | return false; | |
2954 | } | |
4ee9c684 | 2955 | |
1c03e359 | 2956 | /* Worker for both fold_stmt and fold_stmt_inplace. The INPLACE argument |
2957 | distinguishes both cases. */ | |
4ee9c684 | 2958 | |
1c03e359 | 2959 | static bool |
2960 | fold_stmt_1 (gimple_stmt_iterator *gsi, bool inplace) | |
4ee9c684 | 2961 | { |
41511585 | 2962 | bool changed = false; |
75a70cf9 | 2963 | gimple stmt = gsi_stmt (*gsi); |
1c03e359 | 2964 | unsigned i; |
add6ee5e | 2965 | |
75a70cf9 | 2966 | /* Fold the main computation performed by the statement. */ |
2967 | switch (gimple_code (stmt)) | |
4ee9c684 | 2968 | { |
75a70cf9 | 2969 | case GIMPLE_ASSIGN: |
2970 | { | |
1c03e359 | 2971 | unsigned old_num_ops = gimple_num_ops (stmt); |
75a70cf9 | 2972 | tree new_rhs = fold_gimple_assign (gsi); |
1c03e359 | 2973 | if (new_rhs != NULL_TREE |
2974 | && (!inplace | |
2975 | || get_gimple_rhs_num_ops (TREE_CODE (new_rhs)) < old_num_ops)) | |
75a70cf9 | 2976 | { |
2977 | gimple_assign_set_rhs_from_tree (gsi, new_rhs); | |
2978 | changed = true; | |
2979 | } | |
75a70cf9 | 2980 | break; |
2981 | } | |
1c03e359 | 2982 | |
75a70cf9 | 2983 | case GIMPLE_COND: |
2984 | changed |= fold_gimple_cond (stmt); | |
2985 | break; | |
1c03e359 | 2986 | |
75a70cf9 | 2987 | case GIMPLE_CALL: |
1c03e359 | 2988 | /* Fold *& in call arguments. */ |
2989 | for (i = 0; i < gimple_call_num_args (stmt); ++i) | |
2990 | if (REFERENCE_CLASS_P (gimple_call_arg (stmt, i))) | |
2991 | { | |
2992 | tree tmp = maybe_fold_reference (gimple_call_arg (stmt, i), false); | |
2993 | if (tmp) | |
2994 | { | |
2995 | gimple_call_set_arg (stmt, i, tmp); | |
2996 | changed = true; | |
2997 | } | |
2998 | } | |
75a70cf9 | 2999 | /* The entire statement may be replaced in this case. */ |
1c03e359 | 3000 | if (!inplace) |
3001 | changed |= fold_gimple_call (gsi); | |
75a70cf9 | 3002 | break; |
e77b8618 | 3003 | |
1c03e359 | 3004 | case GIMPLE_ASM: |
3005 | /* Fold *& in asm operands. */ | |
3006 | for (i = 0; i < gimple_asm_noutputs (stmt); ++i) | |
3007 | { | |
3008 | tree link = gimple_asm_output_op (stmt, i); | |
3009 | tree op = TREE_VALUE (link); | |
3010 | if (REFERENCE_CLASS_P (op) | |
3011 | && (op = maybe_fold_reference (op, true)) != NULL_TREE) | |
3012 | { | |
3013 | TREE_VALUE (link) = op; | |
3014 | changed = true; | |
3015 | } | |
3016 | } | |
3017 | for (i = 0; i < gimple_asm_ninputs (stmt); ++i) | |
3018 | { | |
3019 | tree link = gimple_asm_input_op (stmt, i); | |
3020 | tree op = TREE_VALUE (link); | |
3021 | if (REFERENCE_CLASS_P (op) | |
3022 | && (op = maybe_fold_reference (op, false)) != NULL_TREE) | |
3023 | { | |
3024 | TREE_VALUE (link) = op; | |
3025 | changed = true; | |
3026 | } | |
3027 | } | |
75a70cf9 | 3028 | break; |
1c03e359 | 3029 | |
3030 | default:; | |
ec0fa513 | 3031 | } |
4ee9c684 | 3032 | |
304557cd | 3033 | stmt = gsi_stmt (*gsi); |
3034 | ||
3035 | /* Fold *& on the lhs. */ | |
3036 | if (gimple_has_lhs (stmt)) | |
3037 | { | |
3038 | tree lhs = gimple_get_lhs (stmt); | |
3039 | if (lhs && REFERENCE_CLASS_P (lhs)) | |
3040 | { | |
3041 | tree new_lhs = maybe_fold_reference (lhs, true); | |
3042 | if (new_lhs) | |
3043 | { | |
3044 | gimple_set_lhs (stmt, new_lhs); | |
3045 | changed = true; | |
3046 | } | |
3047 | } | |
3048 | } | |
3049 | ||
41511585 | 3050 | return changed; |
4ee9c684 | 3051 | } |
3052 | ||
1c03e359 | 3053 | /* Fold the statement pointed to by GSI. In some cases, this function may |
3054 | replace the whole statement with a new one. Returns true iff folding | |
3055 | makes any changes. | |
3056 | The statement pointed to by GSI should be in valid gimple form but may | |
3057 | be in unfolded state as resulting from for example constant propagation | |
3058 | which can produce *&x = 0. */ | |
3059 | ||
3060 | bool | |
3061 | fold_stmt (gimple_stmt_iterator *gsi) | |
3062 | { | |
3063 | return fold_stmt_1 (gsi, false); | |
3064 | } | |
3065 | ||
8171a1dd | 3066 | /* Perform the minimal folding on statement STMT. Only operations like |
3067 | *&x created by constant propagation are handled. The statement cannot | |
75a70cf9 | 3068 | be replaced with a new one. Return true if the statement was |
304557cd | 3069 | changed, false otherwise. |
3070 | The statement STMT should be in valid gimple form but may | |
3071 | be in unfolded state as resulting from for example constant propagation | |
3072 | which can produce *&x = 0. */ | |
8171a1dd | 3073 | |
3074 | bool | |
75a70cf9 | 3075 | fold_stmt_inplace (gimple stmt) |
8171a1dd | 3076 | { |
1c03e359 | 3077 | gimple_stmt_iterator gsi = gsi_for_stmt (stmt); |
3078 | bool changed = fold_stmt_1 (&gsi, true); | |
3079 | gcc_assert (gsi_stmt (gsi) == stmt); | |
8171a1dd | 3080 | return changed; |
3081 | } | |
75a70cf9 | 3082 | |
bdd0e199 | 3083 | /* Try to optimize out __builtin_stack_restore. Optimize it out |
3084 | if there is another __builtin_stack_restore in the same basic | |
3085 | block and no calls or ASM_EXPRs are in between, or if this block's | |
3086 | only outgoing edge is to EXIT_BLOCK and there are no calls or | |
3087 | ASM_EXPRs after this __builtin_stack_restore. */ | |
3088 | ||
3089 | static tree | |
75a70cf9 | 3090 | optimize_stack_restore (gimple_stmt_iterator i) |
bdd0e199 | 3091 | { |
6ea999da | 3092 | tree callee; |
3093 | gimple stmt; | |
75a70cf9 | 3094 | |
3095 | basic_block bb = gsi_bb (i); | |
3096 | gimple call = gsi_stmt (i); | |
bdd0e199 | 3097 | |
75a70cf9 | 3098 | if (gimple_code (call) != GIMPLE_CALL |
3099 | || gimple_call_num_args (call) != 1 | |
3100 | || TREE_CODE (gimple_call_arg (call, 0)) != SSA_NAME | |
3101 | || !POINTER_TYPE_P (TREE_TYPE (gimple_call_arg (call, 0)))) | |
bdd0e199 | 3102 | return NULL_TREE; |
3103 | ||
75a70cf9 | 3104 | for (gsi_next (&i); !gsi_end_p (i); gsi_next (&i)) |
bdd0e199 | 3105 | { |
75a70cf9 | 3106 | stmt = gsi_stmt (i); |
3107 | if (gimple_code (stmt) == GIMPLE_ASM) | |
bdd0e199 | 3108 | return NULL_TREE; |
75a70cf9 | 3109 | if (gimple_code (stmt) != GIMPLE_CALL) |
bdd0e199 | 3110 | continue; |
3111 | ||
75a70cf9 | 3112 | callee = gimple_call_fndecl (stmt); |
bdd0e199 | 3113 | if (!callee || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL) |
3114 | return NULL_TREE; | |
3115 | ||
3116 | if (DECL_FUNCTION_CODE (callee) == BUILT_IN_STACK_RESTORE) | |
6ea999da | 3117 | goto second_stack_restore; |
bdd0e199 | 3118 | } |
3119 | ||
6ea999da | 3120 | if (!gsi_end_p (i)) |
bdd0e199 | 3121 | return NULL_TREE; |
3122 | ||
6ea999da | 3123 | /* Allow one successor of the exit block, or zero successors. */ |
3124 | switch (EDGE_COUNT (bb->succs)) | |
3125 | { | |
3126 | case 0: | |
3127 | break; | |
3128 | case 1: | |
3129 | if (single_succ_edge (bb)->dest != EXIT_BLOCK_PTR) | |
3130 | return NULL_TREE; | |
3131 | break; | |
3132 | default: | |
3133 | return NULL_TREE; | |
3134 | } | |
3135 | second_stack_restore: | |
bdd0e199 | 3136 | |
6ea999da | 3137 | /* If there's exactly one use, then zap the call to __builtin_stack_save. |
3138 | If there are multiple uses, then the last one should remove the call. | |
3139 | In any case, whether the call to __builtin_stack_save can be removed | |
3140 | or not is irrelevant to removing the call to __builtin_stack_restore. */ | |
3141 | if (has_single_use (gimple_call_arg (call, 0))) | |
3142 | { | |
3143 | gimple stack_save = SSA_NAME_DEF_STMT (gimple_call_arg (call, 0)); | |
3144 | if (is_gimple_call (stack_save)) | |
3145 | { | |
3146 | callee = gimple_call_fndecl (stack_save); | |
3147 | if (callee | |
3148 | && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL | |
3149 | && DECL_FUNCTION_CODE (callee) == BUILT_IN_STACK_SAVE) | |
3150 | { | |
3151 | gimple_stmt_iterator stack_save_gsi; | |
3152 | tree rhs; | |
bdd0e199 | 3153 | |
6ea999da | 3154 | stack_save_gsi = gsi_for_stmt (stack_save); |
3155 | rhs = build_int_cst (TREE_TYPE (gimple_call_arg (call, 0)), 0); | |
3156 | update_call_from_tree (&stack_save_gsi, rhs); | |
3157 | } | |
3158 | } | |
3159 | } | |
bdd0e199 | 3160 | |
75a70cf9 | 3161 | /* No effect, so the statement will be deleted. */ |
bdd0e199 | 3162 | return integer_zero_node; |
3163 | } | |
75a70cf9 | 3164 | |
8a58ed0a | 3165 | /* If va_list type is a simple pointer and nothing special is needed, |
3166 | optimize __builtin_va_start (&ap, 0) into ap = __builtin_next_arg (0), | |
3167 | __builtin_va_end (&ap) out as NOP and __builtin_va_copy into a simple | |
3168 | pointer assignment. */ | |
3169 | ||
3170 | static tree | |
75a70cf9 | 3171 | optimize_stdarg_builtin (gimple call) |
8a58ed0a | 3172 | { |
5f57a8b1 | 3173 | tree callee, lhs, rhs, cfun_va_list; |
8a58ed0a | 3174 | bool va_list_simple_ptr; |
389dd41b | 3175 | location_t loc = gimple_location (call); |
8a58ed0a | 3176 | |
75a70cf9 | 3177 | if (gimple_code (call) != GIMPLE_CALL) |
8a58ed0a | 3178 | return NULL_TREE; |
3179 | ||
75a70cf9 | 3180 | callee = gimple_call_fndecl (call); |
5f57a8b1 | 3181 | |
3182 | cfun_va_list = targetm.fn_abi_va_list (callee); | |
3183 | va_list_simple_ptr = POINTER_TYPE_P (cfun_va_list) | |
3184 | && (TREE_TYPE (cfun_va_list) == void_type_node | |
3185 | || TREE_TYPE (cfun_va_list) == char_type_node); | |
3186 | ||
8a58ed0a | 3187 | switch (DECL_FUNCTION_CODE (callee)) |
3188 | { | |
3189 | case BUILT_IN_VA_START: | |
3190 | if (!va_list_simple_ptr | |
3191 | || targetm.expand_builtin_va_start != NULL | |
75a70cf9 | 3192 | || built_in_decls[BUILT_IN_NEXT_ARG] == NULL) |
8a58ed0a | 3193 | return NULL_TREE; |
3194 | ||
75a70cf9 | 3195 | if (gimple_call_num_args (call) != 2) |
8a58ed0a | 3196 | return NULL_TREE; |
3197 | ||
75a70cf9 | 3198 | lhs = gimple_call_arg (call, 0); |
8a58ed0a | 3199 | if (!POINTER_TYPE_P (TREE_TYPE (lhs)) |
3200 | || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs))) | |
5f57a8b1 | 3201 | != TYPE_MAIN_VARIANT (cfun_va_list)) |
8a58ed0a | 3202 | return NULL_TREE; |
75a70cf9 | 3203 | |
389dd41b | 3204 | lhs = build_fold_indirect_ref_loc (loc, lhs); |
3205 | rhs = build_call_expr_loc (loc, built_in_decls[BUILT_IN_NEXT_ARG], | |
75a70cf9 | 3206 | 1, integer_zero_node); |
389dd41b | 3207 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); |
8a58ed0a | 3208 | return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs); |
3209 | ||
3210 | case BUILT_IN_VA_COPY: | |
3211 | if (!va_list_simple_ptr) | |
3212 | return NULL_TREE; | |
3213 | ||
75a70cf9 | 3214 | if (gimple_call_num_args (call) != 2) |
8a58ed0a | 3215 | return NULL_TREE; |
3216 | ||
75a70cf9 | 3217 | lhs = gimple_call_arg (call, 0); |
8a58ed0a | 3218 | if (!POINTER_TYPE_P (TREE_TYPE (lhs)) |
3219 | || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs))) | |
5f57a8b1 | 3220 | != TYPE_MAIN_VARIANT (cfun_va_list)) |
8a58ed0a | 3221 | return NULL_TREE; |
3222 | ||
389dd41b | 3223 | lhs = build_fold_indirect_ref_loc (loc, lhs); |
75a70cf9 | 3224 | rhs = gimple_call_arg (call, 1); |
8a58ed0a | 3225 | if (TYPE_MAIN_VARIANT (TREE_TYPE (rhs)) |
5f57a8b1 | 3226 | != TYPE_MAIN_VARIANT (cfun_va_list)) |
8a58ed0a | 3227 | return NULL_TREE; |
3228 | ||
389dd41b | 3229 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); |
8a58ed0a | 3230 | return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs); |
3231 | ||
3232 | case BUILT_IN_VA_END: | |
75a70cf9 | 3233 | /* No effect, so the statement will be deleted. */ |
8a58ed0a | 3234 | return integer_zero_node; |
3235 | ||
3236 | default: | |
3237 | gcc_unreachable (); | |
3238 | } | |
3239 | } | |
75a70cf9 | 3240 | |
909e5ecb | 3241 | /* Convert EXPR into a GIMPLE value suitable for substitution on the |
3242 | RHS of an assignment. Insert the necessary statements before | |
75a70cf9 | 3243 | iterator *SI_P. The statement at *SI_P, which must be a GIMPLE_CALL |
3244 | is replaced. If the call is expected to produces a result, then it | |
3245 | is replaced by an assignment of the new RHS to the result variable. | |
3246 | If the result is to be ignored, then the call is replaced by a | |
3247 | GIMPLE_NOP. */ | |
909e5ecb | 3248 | |
75a70cf9 | 3249 | static void |
3250 | gimplify_and_update_call_from_tree (gimple_stmt_iterator *si_p, tree expr) | |
909e5ecb | 3251 | { |
75a70cf9 | 3252 | tree lhs; |
3253 | tree tmp = NULL_TREE; /* Silence warning. */ | |
3254 | gimple stmt, new_stmt; | |
3255 | gimple_stmt_iterator i; | |
3256 | gimple_seq stmts = gimple_seq_alloc(); | |
dac18d1a | 3257 | struct gimplify_ctx gctx; |
909e5ecb | 3258 | |
75a70cf9 | 3259 | stmt = gsi_stmt (*si_p); |
3260 | ||
3261 | gcc_assert (is_gimple_call (stmt)); | |
3262 | ||
3263 | lhs = gimple_call_lhs (stmt); | |
3264 | ||
dac18d1a | 3265 | push_gimplify_context (&gctx); |
75a70cf9 | 3266 | |
3267 | if (lhs == NULL_TREE) | |
3268 | gimplify_and_add (expr, &stmts); | |
3269 | else | |
a280136a | 3270 | tmp = get_initialized_tmp_var (expr, &stmts, NULL); |
75a70cf9 | 3271 | |
909e5ecb | 3272 | pop_gimplify_context (NULL); |
3273 | ||
75a70cf9 | 3274 | if (gimple_has_location (stmt)) |
3275 | annotate_all_with_location (stmts, gimple_location (stmt)); | |
b66731e8 | 3276 | |
909e5ecb | 3277 | /* The replacement can expose previously unreferenced variables. */ |
75a70cf9 | 3278 | for (i = gsi_start (stmts); !gsi_end_p (i); gsi_next (&i)) |
3279 | { | |
3280 | new_stmt = gsi_stmt (i); | |
3281 | find_new_referenced_vars (new_stmt); | |
3282 | gsi_insert_before (si_p, new_stmt, GSI_NEW_STMT); | |
3283 | mark_symbols_for_renaming (new_stmt); | |
3284 | gsi_next (si_p); | |
3285 | } | |
3286 | ||
3287 | if (lhs == NULL_TREE) | |
dd277d48 | 3288 | { |
3289 | new_stmt = gimple_build_nop (); | |
3290 | unlink_stmt_vdef (stmt); | |
3291 | release_defs (stmt); | |
3292 | } | |
75a70cf9 | 3293 | else |
909e5ecb | 3294 | { |
75a70cf9 | 3295 | new_stmt = gimple_build_assign (lhs, tmp); |
dd277d48 | 3296 | gimple_set_vuse (new_stmt, gimple_vuse (stmt)); |
3297 | gimple_set_vdef (new_stmt, gimple_vdef (stmt)); | |
75a70cf9 | 3298 | move_ssa_defining_stmt_for_defs (new_stmt, stmt); |
909e5ecb | 3299 | } |
3300 | ||
75a70cf9 | 3301 | gimple_set_location (new_stmt, gimple_location (stmt)); |
3302 | gsi_replace (si_p, new_stmt, false); | |
909e5ecb | 3303 | } |
3304 | ||
4ee9c684 | 3305 | /* A simple pass that attempts to fold all builtin functions. This pass |
3306 | is run after we've propagated as many constants as we can. */ | |
3307 | ||
2a1990e9 | 3308 | static unsigned int |
4ee9c684 | 3309 | execute_fold_all_builtins (void) |
3310 | { | |
b36237eb | 3311 | bool cfg_changed = false; |
4ee9c684 | 3312 | basic_block bb; |
b1b7c0c4 | 3313 | unsigned int todoflags = 0; |
3314 | ||
4ee9c684 | 3315 | FOR_EACH_BB (bb) |
3316 | { | |
75a70cf9 | 3317 | gimple_stmt_iterator i; |
3318 | for (i = gsi_start_bb (bb); !gsi_end_p (i); ) | |
4ee9c684 | 3319 | { |
75a70cf9 | 3320 | gimple stmt, old_stmt; |
4ee9c684 | 3321 | tree callee, result; |
0a39fd54 | 3322 | enum built_in_function fcode; |
4ee9c684 | 3323 | |
75a70cf9 | 3324 | stmt = gsi_stmt (i); |
3325 | ||
3326 | if (gimple_code (stmt) != GIMPLE_CALL) | |
0a39fd54 | 3327 | { |
75a70cf9 | 3328 | gsi_next (&i); |
0a39fd54 | 3329 | continue; |
3330 | } | |
75a70cf9 | 3331 | callee = gimple_call_fndecl (stmt); |
4ee9c684 | 3332 | if (!callee || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL) |
0a39fd54 | 3333 | { |
75a70cf9 | 3334 | gsi_next (&i); |
0a39fd54 | 3335 | continue; |
3336 | } | |
3337 | fcode = DECL_FUNCTION_CODE (callee); | |
4ee9c684 | 3338 | |
75a70cf9 | 3339 | result = ccp_fold_builtin (stmt); |
5a4b7e1e | 3340 | |
3341 | if (result) | |
75a70cf9 | 3342 | gimple_remove_stmt_histograms (cfun, stmt); |
5a4b7e1e | 3343 | |
4ee9c684 | 3344 | if (!result) |
3345 | switch (DECL_FUNCTION_CODE (callee)) | |
3346 | { | |
3347 | case BUILT_IN_CONSTANT_P: | |
3348 | /* Resolve __builtin_constant_p. If it hasn't been | |
3349 | folded to integer_one_node by now, it's fairly | |
3350 | certain that the value simply isn't constant. */ | |
75a70cf9 | 3351 | result = integer_zero_node; |
4ee9c684 | 3352 | break; |
3353 | ||
bdd0e199 | 3354 | case BUILT_IN_STACK_RESTORE: |
75a70cf9 | 3355 | result = optimize_stack_restore (i); |
8a58ed0a | 3356 | if (result) |
3357 | break; | |
75a70cf9 | 3358 | gsi_next (&i); |
8a58ed0a | 3359 | continue; |
3360 | ||
3361 | case BUILT_IN_VA_START: | |
3362 | case BUILT_IN_VA_END: | |
3363 | case BUILT_IN_VA_COPY: | |
3364 | /* These shouldn't be folded before pass_stdarg. */ | |
75a70cf9 | 3365 | result = optimize_stdarg_builtin (stmt); |
bdd0e199 | 3366 | if (result) |
3367 | break; | |
3368 | /* FALLTHRU */ | |
3369 | ||
4ee9c684 | 3370 | default: |
75a70cf9 | 3371 | gsi_next (&i); |
4ee9c684 | 3372 | continue; |
3373 | } | |
3374 | ||
3375 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3376 | { | |
3377 | fprintf (dump_file, "Simplified\n "); | |
75a70cf9 | 3378 | print_gimple_stmt (dump_file, stmt, 0, dump_flags); |
4ee9c684 | 3379 | } |
3380 | ||
75a70cf9 | 3381 | old_stmt = stmt; |
75a70cf9 | 3382 | if (!update_call_from_tree (&i, result)) |
0fefde02 | 3383 | { |
3384 | gimplify_and_update_call_from_tree (&i, result); | |
3385 | todoflags |= TODO_update_address_taken; | |
3386 | } | |
de6ed584 | 3387 | |
75a70cf9 | 3388 | stmt = gsi_stmt (i); |
4c5fd53c | 3389 | update_stmt (stmt); |
de6ed584 | 3390 | |
75a70cf9 | 3391 | if (maybe_clean_or_replace_eh_stmt (old_stmt, stmt) |
3392 | && gimple_purge_dead_eh_edges (bb)) | |
b36237eb | 3393 | cfg_changed = true; |
4ee9c684 | 3394 | |
3395 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3396 | { | |
3397 | fprintf (dump_file, "to\n "); | |
75a70cf9 | 3398 | print_gimple_stmt (dump_file, stmt, 0, dump_flags); |
4ee9c684 | 3399 | fprintf (dump_file, "\n"); |
3400 | } | |
0a39fd54 | 3401 | |
3402 | /* Retry the same statement if it changed into another | |
3403 | builtin, there might be new opportunities now. */ | |
75a70cf9 | 3404 | if (gimple_code (stmt) != GIMPLE_CALL) |
0a39fd54 | 3405 | { |
75a70cf9 | 3406 | gsi_next (&i); |
0a39fd54 | 3407 | continue; |
3408 | } | |
75a70cf9 | 3409 | callee = gimple_call_fndecl (stmt); |
0a39fd54 | 3410 | if (!callee |
75a70cf9 | 3411 | || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL |
0a39fd54 | 3412 | || DECL_FUNCTION_CODE (callee) == fcode) |
75a70cf9 | 3413 | gsi_next (&i); |
4ee9c684 | 3414 | } |
3415 | } | |
b1b7c0c4 | 3416 | |
b36237eb | 3417 | /* Delete unreachable blocks. */ |
b1b7c0c4 | 3418 | if (cfg_changed) |
3419 | todoflags |= TODO_cleanup_cfg; | |
3420 | ||
3421 | return todoflags; | |
4ee9c684 | 3422 | } |
3423 | ||
41511585 | 3424 | |
20099e35 | 3425 | struct gimple_opt_pass pass_fold_builtins = |
4ee9c684 | 3426 | { |
20099e35 | 3427 | { |
3428 | GIMPLE_PASS, | |
4ee9c684 | 3429 | "fab", /* name */ |
3430 | NULL, /* gate */ | |
3431 | execute_fold_all_builtins, /* execute */ | |
3432 | NULL, /* sub */ | |
3433 | NULL, /* next */ | |
3434 | 0, /* static_pass_number */ | |
0b1615c1 | 3435 | TV_NONE, /* tv_id */ |
49290934 | 3436 | PROP_cfg | PROP_ssa, /* properties_required */ |
4ee9c684 | 3437 | 0, /* properties_provided */ |
3438 | 0, /* properties_destroyed */ | |
3439 | 0, /* todo_flags_start */ | |
909e5ecb | 3440 | TODO_dump_func |
3441 | | TODO_verify_ssa | |
20099e35 | 3442 | | TODO_update_ssa /* todo_flags_finish */ |
3443 | } | |
4ee9c684 | 3444 | }; |