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4ee9c684 | 1 | /* Conditional constant propagation pass for the GNU compiler. |
87c0a9fc | 2 | Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, |
3 | 2010 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. | |
48e1416a | 8 | |
4ee9c684 | 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. |
48e1416a | 13 | |
4ee9c684 | 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. | |
48e1416a | 18 | |
4ee9c684 | 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. | |
48e1416a | 66 | |
88dbf20f | 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 | ||
4ee9c684 | 102 | References: |
103 | ||
104 | Constant propagation with conditional branches, | |
105 | Wegman and Zadeck, ACM TOPLAS 13(2):181-210. | |
106 | ||
107 | Building an Optimizing Compiler, | |
108 | Robert Morgan, Butterworth-Heinemann, 1998, Section 8.9. | |
109 | ||
110 | Advanced Compiler Design and Implementation, | |
111 | Steven Muchnick, Morgan Kaufmann, 1997, Section 12.6 */ | |
112 | ||
113 | #include "config.h" | |
114 | #include "system.h" | |
115 | #include "coretypes.h" | |
116 | #include "tm.h" | |
4ee9c684 | 117 | #include "tree.h" |
41511585 | 118 | #include "flags.h" |
4ee9c684 | 119 | #include "tm_p.h" |
4ee9c684 | 120 | #include "basic-block.h" |
41511585 | 121 | #include "output.h" |
41511585 | 122 | #include "function.h" |
ce084dfc | 123 | #include "tree-pretty-print.h" |
124 | #include "gimple-pretty-print.h" | |
41511585 | 125 | #include "timevar.h" |
4ee9c684 | 126 | #include "tree-dump.h" |
41511585 | 127 | #include "tree-flow.h" |
4ee9c684 | 128 | #include "tree-pass.h" |
41511585 | 129 | #include "tree-ssa-propagate.h" |
5a4b7e1e | 130 | #include "value-prof.h" |
41511585 | 131 | #include "langhooks.h" |
8782adcf | 132 | #include "target.h" |
0b205f4c | 133 | #include "diagnostic-core.h" |
add6ee5e | 134 | #include "toplev.h" |
43fb76c1 | 135 | #include "dbgcnt.h" |
4ee9c684 | 136 | |
137 | ||
138 | /* Possible lattice values. */ | |
139 | typedef enum | |
140 | { | |
bfa30570 | 141 | UNINITIALIZED, |
4ee9c684 | 142 | UNDEFINED, |
143 | CONSTANT, | |
144 | VARYING | |
88dbf20f | 145 | } ccp_lattice_t; |
4ee9c684 | 146 | |
14f101cf | 147 | struct prop_value_d { |
148 | /* Lattice value. */ | |
149 | ccp_lattice_t lattice_val; | |
150 | ||
151 | /* Propagated value. */ | |
152 | tree value; | |
153 | }; | |
154 | ||
155 | typedef struct prop_value_d prop_value_t; | |
156 | ||
88dbf20f | 157 | /* Array of propagated constant values. After propagation, |
158 | CONST_VAL[I].VALUE holds the constant value for SSA_NAME(I). If | |
159 | the constant is held in an SSA name representing a memory store | |
4fb5e5ca | 160 | (i.e., a VDEF), CONST_VAL[I].MEM_REF will contain the actual |
161 | memory reference used to store (i.e., the LHS of the assignment | |
162 | doing the store). */ | |
20140406 | 163 | static prop_value_t *const_val; |
4ee9c684 | 164 | |
4af351a8 | 165 | static void canonicalize_float_value (prop_value_t *); |
6688f8ec | 166 | static bool ccp_fold_stmt (gimple_stmt_iterator *); |
4af351a8 | 167 | |
88dbf20f | 168 | /* Dump constant propagation value VAL to file OUTF prefixed by PREFIX. */ |
01406fc0 | 169 | |
170 | static void | |
88dbf20f | 171 | dump_lattice_value (FILE *outf, const char *prefix, prop_value_t val) |
01406fc0 | 172 | { |
41511585 | 173 | switch (val.lattice_val) |
01406fc0 | 174 | { |
88dbf20f | 175 | case UNINITIALIZED: |
176 | fprintf (outf, "%sUNINITIALIZED", prefix); | |
177 | break; | |
41511585 | 178 | case UNDEFINED: |
179 | fprintf (outf, "%sUNDEFINED", prefix); | |
180 | break; | |
181 | case VARYING: | |
182 | fprintf (outf, "%sVARYING", prefix); | |
183 | break; | |
41511585 | 184 | case CONSTANT: |
185 | fprintf (outf, "%sCONSTANT ", prefix); | |
88dbf20f | 186 | print_generic_expr (outf, val.value, dump_flags); |
41511585 | 187 | break; |
188 | default: | |
8c0963c4 | 189 | gcc_unreachable (); |
41511585 | 190 | } |
01406fc0 | 191 | } |
4ee9c684 | 192 | |
4ee9c684 | 193 | |
88dbf20f | 194 | /* Print lattice value VAL to stderr. */ |
195 | ||
196 | void debug_lattice_value (prop_value_t val); | |
197 | ||
4b987fac | 198 | DEBUG_FUNCTION void |
88dbf20f | 199 | debug_lattice_value (prop_value_t val) |
200 | { | |
201 | dump_lattice_value (stderr, "", val); | |
202 | fprintf (stderr, "\n"); | |
203 | } | |
4ee9c684 | 204 | |
4ee9c684 | 205 | |
88dbf20f | 206 | /* Compute a default value for variable VAR and store it in the |
207 | CONST_VAL array. The following rules are used to get default | |
208 | values: | |
01406fc0 | 209 | |
88dbf20f | 210 | 1- Global and static variables that are declared constant are |
211 | considered CONSTANT. | |
212 | ||
213 | 2- Any other value is considered UNDEFINED. This is useful when | |
41511585 | 214 | considering PHI nodes. PHI arguments that are undefined do not |
215 | change the constant value of the PHI node, which allows for more | |
88dbf20f | 216 | constants to be propagated. |
4ee9c684 | 217 | |
8883e700 | 218 | 3- Variables defined by statements other than assignments and PHI |
88dbf20f | 219 | nodes are considered VARYING. |
4ee9c684 | 220 | |
8883e700 | 221 | 4- Initial values of variables that are not GIMPLE registers are |
bfa30570 | 222 | considered VARYING. */ |
4ee9c684 | 223 | |
88dbf20f | 224 | static prop_value_t |
225 | get_default_value (tree var) | |
226 | { | |
227 | tree sym = SSA_NAME_VAR (var); | |
61207d43 | 228 | prop_value_t val = { UNINITIALIZED, NULL_TREE }; |
8edeb88b | 229 | gimple stmt; |
230 | ||
231 | stmt = SSA_NAME_DEF_STMT (var); | |
232 | ||
233 | if (gimple_nop_p (stmt)) | |
4ee9c684 | 234 | { |
8edeb88b | 235 | /* Variables defined by an empty statement are those used |
236 | before being initialized. If VAR is a local variable, we | |
237 | can assume initially that it is UNDEFINED, otherwise we must | |
238 | consider it VARYING. */ | |
524a0531 | 239 | if (is_gimple_reg (sym) |
240 | && TREE_CODE (sym) == VAR_DECL) | |
8edeb88b | 241 | val.lattice_val = UNDEFINED; |
242 | else | |
243 | val.lattice_val = VARYING; | |
4ee9c684 | 244 | } |
8edeb88b | 245 | else if (is_gimple_assign (stmt) |
246 | /* Value-returning GIMPLE_CALL statements assign to | |
247 | a variable, and are treated similarly to GIMPLE_ASSIGN. */ | |
248 | || (is_gimple_call (stmt) | |
249 | && gimple_call_lhs (stmt) != NULL_TREE) | |
250 | || gimple_code (stmt) == GIMPLE_PHI) | |
41511585 | 251 | { |
8edeb88b | 252 | tree cst; |
253 | if (gimple_assign_single_p (stmt) | |
254 | && DECL_P (gimple_assign_rhs1 (stmt)) | |
255 | && (cst = get_symbol_constant_value (gimple_assign_rhs1 (stmt)))) | |
88dbf20f | 256 | { |
8edeb88b | 257 | val.lattice_val = CONSTANT; |
258 | val.value = cst; | |
88dbf20f | 259 | } |
260 | else | |
8edeb88b | 261 | /* Any other variable defined by an assignment or a PHI node |
262 | is considered UNDEFINED. */ | |
263 | val.lattice_val = UNDEFINED; | |
264 | } | |
265 | else | |
266 | { | |
267 | /* Otherwise, VAR will never take on a constant value. */ | |
268 | val.lattice_val = VARYING; | |
41511585 | 269 | } |
4ee9c684 | 270 | |
41511585 | 271 | return val; |
272 | } | |
4ee9c684 | 273 | |
4ee9c684 | 274 | |
bfa30570 | 275 | /* Get the constant value associated with variable VAR. */ |
4ee9c684 | 276 | |
bfa30570 | 277 | static inline prop_value_t * |
278 | get_value (tree var) | |
88dbf20f | 279 | { |
e004838d | 280 | prop_value_t *val; |
bfa30570 | 281 | |
e004838d | 282 | if (const_val == NULL) |
283 | return NULL; | |
284 | ||
285 | val = &const_val[SSA_NAME_VERSION (var)]; | |
bfa30570 | 286 | if (val->lattice_val == UNINITIALIZED) |
4ee9c684 | 287 | *val = get_default_value (var); |
288 | ||
4af351a8 | 289 | canonicalize_float_value (val); |
290 | ||
4ee9c684 | 291 | return val; |
292 | } | |
293 | ||
15d138c9 | 294 | /* Return the constant tree value associated with VAR. */ |
295 | ||
296 | static inline tree | |
297 | get_constant_value (tree var) | |
298 | { | |
299 | prop_value_t *val = get_value (var); | |
300 | if (val && val->lattice_val == CONSTANT) | |
301 | return val->value; | |
302 | return NULL_TREE; | |
303 | } | |
304 | ||
bfa30570 | 305 | /* Sets the value associated with VAR to VARYING. */ |
306 | ||
307 | static inline void | |
308 | set_value_varying (tree var) | |
309 | { | |
310 | prop_value_t *val = &const_val[SSA_NAME_VERSION (var)]; | |
311 | ||
312 | val->lattice_val = VARYING; | |
313 | val->value = NULL_TREE; | |
bfa30570 | 314 | } |
4ee9c684 | 315 | |
b31eb493 | 316 | /* For float types, modify the value of VAL to make ccp work correctly |
317 | for non-standard values (-0, NaN): | |
318 | ||
319 | If HONOR_SIGNED_ZEROS is false, and VAL = -0, we canonicalize it to 0. | |
320 | If HONOR_NANS is false, and VAL is NaN, we canonicalize it to UNDEFINED. | |
321 | This is to fix the following problem (see PR 29921): Suppose we have | |
322 | ||
323 | x = 0.0 * y | |
324 | ||
325 | and we set value of y to NaN. This causes value of x to be set to NaN. | |
326 | When we later determine that y is in fact VARYING, fold uses the fact | |
327 | that HONOR_NANS is false, and we try to change the value of x to 0, | |
328 | causing an ICE. With HONOR_NANS being false, the real appearance of | |
329 | NaN would cause undefined behavior, though, so claiming that y (and x) | |
330 | are UNDEFINED initially is correct. */ | |
331 | ||
332 | static void | |
333 | canonicalize_float_value (prop_value_t *val) | |
334 | { | |
335 | enum machine_mode mode; | |
336 | tree type; | |
337 | REAL_VALUE_TYPE d; | |
338 | ||
339 | if (val->lattice_val != CONSTANT | |
340 | || TREE_CODE (val->value) != REAL_CST) | |
341 | return; | |
342 | ||
343 | d = TREE_REAL_CST (val->value); | |
344 | type = TREE_TYPE (val->value); | |
345 | mode = TYPE_MODE (type); | |
346 | ||
347 | if (!HONOR_SIGNED_ZEROS (mode) | |
348 | && REAL_VALUE_MINUS_ZERO (d)) | |
349 | { | |
350 | val->value = build_real (type, dconst0); | |
351 | return; | |
352 | } | |
353 | ||
354 | if (!HONOR_NANS (mode) | |
355 | && REAL_VALUE_ISNAN (d)) | |
356 | { | |
357 | val->lattice_val = UNDEFINED; | |
358 | val->value = NULL; | |
b31eb493 | 359 | return; |
360 | } | |
361 | } | |
362 | ||
88dbf20f | 363 | /* Set the value for variable VAR to NEW_VAL. Return true if the new |
364 | value is different from VAR's previous value. */ | |
4ee9c684 | 365 | |
41511585 | 366 | static bool |
88dbf20f | 367 | set_lattice_value (tree var, prop_value_t new_val) |
4ee9c684 | 368 | { |
6d0bf6d6 | 369 | /* We can deal with old UNINITIALIZED values just fine here. */ |
370 | prop_value_t *old_val = &const_val[SSA_NAME_VERSION (var)]; | |
88dbf20f | 371 | |
b31eb493 | 372 | canonicalize_float_value (&new_val); |
373 | ||
88dbf20f | 374 | /* Lattice transitions must always be monotonically increasing in |
bfa30570 | 375 | value. If *OLD_VAL and NEW_VAL are the same, return false to |
376 | inform the caller that this was a non-transition. */ | |
377 | ||
aecfc21d | 378 | gcc_assert (old_val->lattice_val < new_val.lattice_val |
88dbf20f | 379 | || (old_val->lattice_val == new_val.lattice_val |
aecfc21d | 380 | && ((!old_val->value && !new_val.value) |
61207d43 | 381 | || operand_equal_p (old_val->value, new_val.value, 0)))); |
88dbf20f | 382 | |
383 | if (old_val->lattice_val != new_val.lattice_val) | |
4ee9c684 | 384 | { |
41511585 | 385 | if (dump_file && (dump_flags & TDF_DETAILS)) |
386 | { | |
88dbf20f | 387 | dump_lattice_value (dump_file, "Lattice value changed to ", new_val); |
bfa30570 | 388 | fprintf (dump_file, ". Adding SSA edges to worklist.\n"); |
41511585 | 389 | } |
390 | ||
88dbf20f | 391 | *old_val = new_val; |
392 | ||
6d0bf6d6 | 393 | gcc_assert (new_val.lattice_val != UNINITIALIZED); |
bfa30570 | 394 | return true; |
4ee9c684 | 395 | } |
41511585 | 396 | |
397 | return false; | |
4ee9c684 | 398 | } |
399 | ||
6d0bf6d6 | 400 | /* Return the value for the tree operand EXPR. */ |
401 | ||
402 | static prop_value_t | |
403 | get_value_for_expr (tree expr) | |
404 | { | |
405 | prop_value_t val; | |
406 | ||
407 | if (TREE_CODE (expr) == SSA_NAME) | |
408 | val = *(get_value (expr)); | |
409 | else if (is_gimple_min_invariant (expr)) | |
410 | { | |
411 | val.lattice_val = CONSTANT; | |
412 | val.value = expr; | |
413 | canonicalize_float_value (&val); | |
414 | } | |
415 | else | |
416 | { | |
417 | val.lattice_val = VARYING; | |
418 | val.value = NULL_TREE; | |
419 | } | |
420 | ||
421 | return val; | |
422 | } | |
423 | ||
4ee9c684 | 424 | |
88dbf20f | 425 | /* Return the likely CCP lattice value for STMT. |
4ee9c684 | 426 | |
41511585 | 427 | If STMT has no operands, then return CONSTANT. |
4ee9c684 | 428 | |
d61b9af3 | 429 | Else if undefinedness of operands of STMT cause its value to be |
430 | undefined, then return UNDEFINED. | |
4ee9c684 | 431 | |
41511585 | 432 | Else if any operands of STMT are constants, then return CONSTANT. |
4ee9c684 | 433 | |
41511585 | 434 | Else return VARYING. */ |
4ee9c684 | 435 | |
88dbf20f | 436 | static ccp_lattice_t |
75a70cf9 | 437 | likely_value (gimple stmt) |
41511585 | 438 | { |
d61b9af3 | 439 | bool has_constant_operand, has_undefined_operand, all_undefined_operands; |
41511585 | 440 | tree use; |
441 | ssa_op_iter iter; | |
8edeb88b | 442 | unsigned i; |
4ee9c684 | 443 | |
590c3166 | 444 | enum gimple_code code = gimple_code (stmt); |
75a70cf9 | 445 | |
446 | /* This function appears to be called only for assignments, calls, | |
447 | conditionals, and switches, due to the logic in visit_stmt. */ | |
448 | gcc_assert (code == GIMPLE_ASSIGN | |
449 | || code == GIMPLE_CALL | |
450 | || code == GIMPLE_COND | |
451 | || code == GIMPLE_SWITCH); | |
88dbf20f | 452 | |
453 | /* If the statement has volatile operands, it won't fold to a | |
454 | constant value. */ | |
75a70cf9 | 455 | if (gimple_has_volatile_ops (stmt)) |
88dbf20f | 456 | return VARYING; |
457 | ||
75a70cf9 | 458 | /* Arrive here for more complex cases. */ |
bfa30570 | 459 | has_constant_operand = false; |
d61b9af3 | 460 | has_undefined_operand = false; |
461 | all_undefined_operands = true; | |
8edeb88b | 462 | FOR_EACH_SSA_TREE_OPERAND (use, stmt, iter, SSA_OP_USE) |
41511585 | 463 | { |
bfa30570 | 464 | prop_value_t *val = get_value (use); |
41511585 | 465 | |
bfa30570 | 466 | if (val->lattice_val == UNDEFINED) |
d61b9af3 | 467 | has_undefined_operand = true; |
468 | else | |
469 | all_undefined_operands = false; | |
88dbf20f | 470 | |
41511585 | 471 | if (val->lattice_val == CONSTANT) |
bfa30570 | 472 | has_constant_operand = true; |
4ee9c684 | 473 | } |
41511585 | 474 | |
dd277d48 | 475 | /* There may be constants in regular rhs operands. For calls we |
476 | have to ignore lhs, fndecl and static chain, otherwise only | |
477 | the lhs. */ | |
478 | for (i = (is_gimple_call (stmt) ? 2 : 0) + gimple_has_lhs (stmt); | |
8edeb88b | 479 | i < gimple_num_ops (stmt); ++i) |
480 | { | |
481 | tree op = gimple_op (stmt, i); | |
482 | if (!op || TREE_CODE (op) == SSA_NAME) | |
483 | continue; | |
484 | if (is_gimple_min_invariant (op)) | |
485 | has_constant_operand = true; | |
486 | } | |
487 | ||
87c0a9fc | 488 | if (has_constant_operand) |
489 | all_undefined_operands = false; | |
490 | ||
d61b9af3 | 491 | /* If the operation combines operands like COMPLEX_EXPR make sure to |
492 | not mark the result UNDEFINED if only one part of the result is | |
493 | undefined. */ | |
75a70cf9 | 494 | if (has_undefined_operand && all_undefined_operands) |
d61b9af3 | 495 | return UNDEFINED; |
75a70cf9 | 496 | else if (code == GIMPLE_ASSIGN && has_undefined_operand) |
d61b9af3 | 497 | { |
75a70cf9 | 498 | switch (gimple_assign_rhs_code (stmt)) |
d61b9af3 | 499 | { |
500 | /* Unary operators are handled with all_undefined_operands. */ | |
501 | case PLUS_EXPR: | |
502 | case MINUS_EXPR: | |
d61b9af3 | 503 | case POINTER_PLUS_EXPR: |
d61b9af3 | 504 | /* Not MIN_EXPR, MAX_EXPR. One VARYING operand may be selected. |
505 | Not bitwise operators, one VARYING operand may specify the | |
506 | result completely. Not logical operators for the same reason. | |
05a936a0 | 507 | Not COMPLEX_EXPR as one VARYING operand makes the result partly |
508 | not UNDEFINED. Not *DIV_EXPR, comparisons and shifts because | |
509 | the undefined operand may be promoted. */ | |
d61b9af3 | 510 | return UNDEFINED; |
511 | ||
512 | default: | |
513 | ; | |
514 | } | |
515 | } | |
516 | /* If there was an UNDEFINED operand but the result may be not UNDEFINED | |
517 | fall back to VARYING even if there were CONSTANT operands. */ | |
518 | if (has_undefined_operand) | |
519 | return VARYING; | |
520 | ||
8edeb88b | 521 | /* We do not consider virtual operands here -- load from read-only |
522 | memory may have only VARYING virtual operands, but still be | |
523 | constant. */ | |
bfa30570 | 524 | if (has_constant_operand |
8edeb88b | 525 | || gimple_references_memory_p (stmt)) |
88dbf20f | 526 | return CONSTANT; |
527 | ||
bfa30570 | 528 | return VARYING; |
4ee9c684 | 529 | } |
530 | ||
bfa30570 | 531 | /* Returns true if STMT cannot be constant. */ |
532 | ||
533 | static bool | |
75a70cf9 | 534 | surely_varying_stmt_p (gimple stmt) |
bfa30570 | 535 | { |
536 | /* If the statement has operands that we cannot handle, it cannot be | |
537 | constant. */ | |
75a70cf9 | 538 | if (gimple_has_volatile_ops (stmt)) |
bfa30570 | 539 | return true; |
540 | ||
f257af64 | 541 | /* If it is a call and does not return a value or is not a |
542 | builtin and not an indirect call, it is varying. */ | |
75a70cf9 | 543 | if (is_gimple_call (stmt)) |
f257af64 | 544 | { |
545 | tree fndecl; | |
546 | if (!gimple_call_lhs (stmt) | |
547 | || ((fndecl = gimple_call_fndecl (stmt)) != NULL_TREE | |
5768aeb3 | 548 | && !DECL_BUILT_IN (fndecl))) |
f257af64 | 549 | return true; |
550 | } | |
bfa30570 | 551 | |
8edeb88b | 552 | /* Any other store operation is not interesting. */ |
dd277d48 | 553 | else if (gimple_vdef (stmt)) |
8edeb88b | 554 | return true; |
555 | ||
bfa30570 | 556 | /* Anything other than assignments and conditional jumps are not |
557 | interesting for CCP. */ | |
75a70cf9 | 558 | if (gimple_code (stmt) != GIMPLE_ASSIGN |
f257af64 | 559 | && gimple_code (stmt) != GIMPLE_COND |
560 | && gimple_code (stmt) != GIMPLE_SWITCH | |
561 | && gimple_code (stmt) != GIMPLE_CALL) | |
bfa30570 | 562 | return true; |
563 | ||
564 | return false; | |
565 | } | |
4ee9c684 | 566 | |
41511585 | 567 | /* Initialize local data structures for CCP. */ |
4ee9c684 | 568 | |
569 | static void | |
41511585 | 570 | ccp_initialize (void) |
4ee9c684 | 571 | { |
41511585 | 572 | basic_block bb; |
4ee9c684 | 573 | |
43959b95 | 574 | const_val = XCNEWVEC (prop_value_t, num_ssa_names); |
4ee9c684 | 575 | |
41511585 | 576 | /* Initialize simulation flags for PHI nodes and statements. */ |
577 | FOR_EACH_BB (bb) | |
4ee9c684 | 578 | { |
75a70cf9 | 579 | gimple_stmt_iterator i; |
4ee9c684 | 580 | |
75a70cf9 | 581 | for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i)) |
41511585 | 582 | { |
75a70cf9 | 583 | gimple stmt = gsi_stmt (i); |
2193544e | 584 | bool is_varying; |
585 | ||
586 | /* If the statement is a control insn, then we do not | |
587 | want to avoid simulating the statement once. Failure | |
588 | to do so means that those edges will never get added. */ | |
589 | if (stmt_ends_bb_p (stmt)) | |
590 | is_varying = false; | |
591 | else | |
592 | is_varying = surely_varying_stmt_p (stmt); | |
4ee9c684 | 593 | |
bfa30570 | 594 | if (is_varying) |
41511585 | 595 | { |
88dbf20f | 596 | tree def; |
597 | ssa_op_iter iter; | |
598 | ||
599 | /* If the statement will not produce a constant, mark | |
600 | all its outputs VARYING. */ | |
601 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS) | |
8edeb88b | 602 | set_value_varying (def); |
41511585 | 603 | } |
75a70cf9 | 604 | prop_set_simulate_again (stmt, !is_varying); |
41511585 | 605 | } |
4ee9c684 | 606 | } |
607 | ||
75a70cf9 | 608 | /* Now process PHI nodes. We never clear the simulate_again flag on |
609 | phi nodes, since we do not know which edges are executable yet, | |
610 | except for phi nodes for virtual operands when we do not do store ccp. */ | |
41511585 | 611 | FOR_EACH_BB (bb) |
4ee9c684 | 612 | { |
75a70cf9 | 613 | gimple_stmt_iterator i; |
41511585 | 614 | |
75a70cf9 | 615 | for (i = gsi_start_phis (bb); !gsi_end_p (i); gsi_next (&i)) |
616 | { | |
617 | gimple phi = gsi_stmt (i); | |
618 | ||
61207d43 | 619 | if (!is_gimple_reg (gimple_phi_result (phi))) |
75a70cf9 | 620 | prop_set_simulate_again (phi, false); |
bfa30570 | 621 | else |
75a70cf9 | 622 | prop_set_simulate_again (phi, true); |
41511585 | 623 | } |
4ee9c684 | 624 | } |
41511585 | 625 | } |
4ee9c684 | 626 | |
43fb76c1 | 627 | /* Debug count support. Reset the values of ssa names |
628 | VARYING when the total number ssa names analyzed is | |
629 | beyond the debug count specified. */ | |
630 | ||
631 | static void | |
632 | do_dbg_cnt (void) | |
633 | { | |
634 | unsigned i; | |
635 | for (i = 0; i < num_ssa_names; i++) | |
636 | { | |
637 | if (!dbg_cnt (ccp)) | |
638 | { | |
639 | const_val[i].lattice_val = VARYING; | |
640 | const_val[i].value = NULL_TREE; | |
641 | } | |
642 | } | |
643 | } | |
644 | ||
4ee9c684 | 645 | |
88dbf20f | 646 | /* Do final substitution of propagated values, cleanup the flowgraph and |
48e1416a | 647 | free allocated storage. |
4ee9c684 | 648 | |
33a34f1e | 649 | Return TRUE when something was optimized. */ |
650 | ||
651 | static bool | |
88dbf20f | 652 | ccp_finalize (void) |
4ee9c684 | 653 | { |
43fb76c1 | 654 | bool something_changed; |
655 | ||
656 | do_dbg_cnt (); | |
88dbf20f | 657 | /* Perform substitutions based on the known constant values. */ |
14f101cf | 658 | something_changed = substitute_and_fold (get_constant_value, |
659 | ccp_fold_stmt, true); | |
4ee9c684 | 660 | |
88dbf20f | 661 | free (const_val); |
e004838d | 662 | const_val = NULL; |
33a34f1e | 663 | return something_changed;; |
4ee9c684 | 664 | } |
665 | ||
666 | ||
88dbf20f | 667 | /* Compute the meet operator between *VAL1 and *VAL2. Store the result |
668 | in VAL1. | |
669 | ||
670 | any M UNDEFINED = any | |
88dbf20f | 671 | any M VARYING = VARYING |
672 | Ci M Cj = Ci if (i == j) | |
673 | Ci M Cj = VARYING if (i != j) | |
bfa30570 | 674 | */ |
4ee9c684 | 675 | |
676 | static void | |
88dbf20f | 677 | ccp_lattice_meet (prop_value_t *val1, prop_value_t *val2) |
4ee9c684 | 678 | { |
88dbf20f | 679 | if (val1->lattice_val == UNDEFINED) |
4ee9c684 | 680 | { |
88dbf20f | 681 | /* UNDEFINED M any = any */ |
682 | *val1 = *val2; | |
41511585 | 683 | } |
88dbf20f | 684 | else if (val2->lattice_val == UNDEFINED) |
92481a4d | 685 | { |
88dbf20f | 686 | /* any M UNDEFINED = any |
687 | Nothing to do. VAL1 already contains the value we want. */ | |
688 | ; | |
92481a4d | 689 | } |
88dbf20f | 690 | else if (val1->lattice_val == VARYING |
691 | || val2->lattice_val == VARYING) | |
41511585 | 692 | { |
88dbf20f | 693 | /* any M VARYING = VARYING. */ |
694 | val1->lattice_val = VARYING; | |
695 | val1->value = NULL_TREE; | |
41511585 | 696 | } |
88dbf20f | 697 | else if (val1->lattice_val == CONSTANT |
698 | && val2->lattice_val == CONSTANT | |
61207d43 | 699 | && simple_cst_equal (val1->value, val2->value) == 1) |
41511585 | 700 | { |
88dbf20f | 701 | /* Ci M Cj = Ci if (i == j) |
702 | Ci M Cj = VARYING if (i != j) | |
703 | ||
704 | If these two values come from memory stores, make sure that | |
7739e598 | 705 | they come from the same memory reference. |
706 | Nothing to do. VAL1 already contains the value we want. */ | |
41511585 | 707 | } |
708 | else | |
709 | { | |
88dbf20f | 710 | /* Any other combination is VARYING. */ |
711 | val1->lattice_val = VARYING; | |
712 | val1->value = NULL_TREE; | |
41511585 | 713 | } |
4ee9c684 | 714 | } |
715 | ||
716 | ||
41511585 | 717 | /* Loop through the PHI_NODE's parameters for BLOCK and compare their |
718 | lattice values to determine PHI_NODE's lattice value. The value of a | |
88dbf20f | 719 | PHI node is determined calling ccp_lattice_meet with all the arguments |
41511585 | 720 | of the PHI node that are incoming via executable edges. */ |
4ee9c684 | 721 | |
41511585 | 722 | static enum ssa_prop_result |
75a70cf9 | 723 | ccp_visit_phi_node (gimple phi) |
4ee9c684 | 724 | { |
75a70cf9 | 725 | unsigned i; |
88dbf20f | 726 | prop_value_t *old_val, new_val; |
4ee9c684 | 727 | |
41511585 | 728 | if (dump_file && (dump_flags & TDF_DETAILS)) |
4ee9c684 | 729 | { |
41511585 | 730 | fprintf (dump_file, "\nVisiting PHI node: "); |
75a70cf9 | 731 | print_gimple_stmt (dump_file, phi, 0, dump_flags); |
4ee9c684 | 732 | } |
4ee9c684 | 733 | |
75a70cf9 | 734 | old_val = get_value (gimple_phi_result (phi)); |
41511585 | 735 | switch (old_val->lattice_val) |
736 | { | |
737 | case VARYING: | |
88dbf20f | 738 | return SSA_PROP_VARYING; |
4ee9c684 | 739 | |
41511585 | 740 | case CONSTANT: |
741 | new_val = *old_val; | |
742 | break; | |
4ee9c684 | 743 | |
41511585 | 744 | case UNDEFINED: |
41511585 | 745 | new_val.lattice_val = UNDEFINED; |
88dbf20f | 746 | new_val.value = NULL_TREE; |
41511585 | 747 | break; |
4ee9c684 | 748 | |
41511585 | 749 | default: |
8c0963c4 | 750 | gcc_unreachable (); |
41511585 | 751 | } |
4ee9c684 | 752 | |
75a70cf9 | 753 | for (i = 0; i < gimple_phi_num_args (phi); i++) |
41511585 | 754 | { |
88dbf20f | 755 | /* Compute the meet operator over all the PHI arguments flowing |
756 | through executable edges. */ | |
75a70cf9 | 757 | edge e = gimple_phi_arg_edge (phi, i); |
4ee9c684 | 758 | |
41511585 | 759 | if (dump_file && (dump_flags & TDF_DETAILS)) |
760 | { | |
761 | fprintf (dump_file, | |
762 | "\n Argument #%d (%d -> %d %sexecutable)\n", | |
763 | i, e->src->index, e->dest->index, | |
764 | (e->flags & EDGE_EXECUTABLE) ? "" : "not "); | |
765 | } | |
766 | ||
767 | /* If the incoming edge is executable, Compute the meet operator for | |
768 | the existing value of the PHI node and the current PHI argument. */ | |
769 | if (e->flags & EDGE_EXECUTABLE) | |
770 | { | |
75a70cf9 | 771 | tree arg = gimple_phi_arg (phi, i)->def; |
6d0bf6d6 | 772 | prop_value_t arg_val = get_value_for_expr (arg); |
4ee9c684 | 773 | |
88dbf20f | 774 | ccp_lattice_meet (&new_val, &arg_val); |
4ee9c684 | 775 | |
41511585 | 776 | if (dump_file && (dump_flags & TDF_DETAILS)) |
777 | { | |
778 | fprintf (dump_file, "\t"); | |
88dbf20f | 779 | print_generic_expr (dump_file, arg, dump_flags); |
780 | dump_lattice_value (dump_file, "\tValue: ", arg_val); | |
41511585 | 781 | fprintf (dump_file, "\n"); |
782 | } | |
4ee9c684 | 783 | |
41511585 | 784 | if (new_val.lattice_val == VARYING) |
785 | break; | |
786 | } | |
787 | } | |
4ee9c684 | 788 | |
789 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
41511585 | 790 | { |
791 | dump_lattice_value (dump_file, "\n PHI node value: ", new_val); | |
792 | fprintf (dump_file, "\n\n"); | |
793 | } | |
794 | ||
bfa30570 | 795 | /* Make the transition to the new value. */ |
75a70cf9 | 796 | if (set_lattice_value (gimple_phi_result (phi), new_val)) |
41511585 | 797 | { |
798 | if (new_val.lattice_val == VARYING) | |
799 | return SSA_PROP_VARYING; | |
800 | else | |
801 | return SSA_PROP_INTERESTING; | |
802 | } | |
803 | else | |
804 | return SSA_PROP_NOT_INTERESTING; | |
4ee9c684 | 805 | } |
806 | ||
15d138c9 | 807 | /* Return the constant value for OP or OP otherwise. */ |
00f4f705 | 808 | |
809 | static tree | |
15d138c9 | 810 | valueize_op (tree op) |
00f4f705 | 811 | { |
00f4f705 | 812 | if (TREE_CODE (op) == SSA_NAME) |
813 | { | |
15d138c9 | 814 | tree tem = get_constant_value (op); |
815 | if (tem) | |
816 | return tem; | |
00f4f705 | 817 | } |
818 | return op; | |
819 | } | |
820 | ||
41511585 | 821 | /* CCP specific front-end to the non-destructive constant folding |
822 | routines. | |
4ee9c684 | 823 | |
824 | Attempt to simplify the RHS of STMT knowing that one or more | |
825 | operands are constants. | |
826 | ||
827 | If simplification is possible, return the simplified RHS, | |
75a70cf9 | 828 | otherwise return the original RHS or NULL_TREE. */ |
4ee9c684 | 829 | |
830 | static tree | |
75a70cf9 | 831 | ccp_fold (gimple stmt) |
4ee9c684 | 832 | { |
389dd41b | 833 | location_t loc = gimple_location (stmt); |
75a70cf9 | 834 | switch (gimple_code (stmt)) |
88dbf20f | 835 | { |
75a70cf9 | 836 | case GIMPLE_ASSIGN: |
837 | { | |
838 | enum tree_code subcode = gimple_assign_rhs_code (stmt); | |
839 | ||
840 | switch (get_gimple_rhs_class (subcode)) | |
841 | { | |
842 | case GIMPLE_SINGLE_RHS: | |
843 | { | |
844 | tree rhs = gimple_assign_rhs1 (stmt); | |
845 | enum tree_code_class kind = TREE_CODE_CLASS (subcode); | |
846 | ||
847 | if (TREE_CODE (rhs) == SSA_NAME) | |
848 | { | |
849 | /* If the RHS is an SSA_NAME, return its known constant value, | |
850 | if any. */ | |
15d138c9 | 851 | return get_constant_value (rhs); |
75a70cf9 | 852 | } |
853 | /* Handle propagating invariant addresses into address operations. | |
854 | The folding we do here matches that in tree-ssa-forwprop.c. */ | |
855 | else if (TREE_CODE (rhs) == ADDR_EXPR) | |
856 | { | |
857 | tree *base; | |
858 | base = &TREE_OPERAND (rhs, 0); | |
859 | while (handled_component_p (*base)) | |
860 | base = &TREE_OPERAND (*base, 0); | |
182cf5a9 | 861 | if (TREE_CODE (*base) == MEM_REF |
75a70cf9 | 862 | && TREE_CODE (TREE_OPERAND (*base, 0)) == SSA_NAME) |
863 | { | |
15d138c9 | 864 | tree val = get_constant_value (TREE_OPERAND (*base, 0)); |
865 | if (val | |
866 | && TREE_CODE (val) == ADDR_EXPR) | |
75a70cf9 | 867 | { |
182cf5a9 | 868 | tree ret, save = *base; |
869 | tree new_base; | |
870 | new_base = fold_build2 (MEM_REF, TREE_TYPE (*base), | |
15d138c9 | 871 | unshare_expr (val), |
182cf5a9 | 872 | TREE_OPERAND (*base, 1)); |
75a70cf9 | 873 | /* We need to return a new tree, not modify the IL |
874 | or share parts of it. So play some tricks to | |
875 | avoid manually building it. */ | |
182cf5a9 | 876 | *base = new_base; |
75a70cf9 | 877 | ret = unshare_expr (rhs); |
878 | recompute_tree_invariant_for_addr_expr (ret); | |
879 | *base = save; | |
880 | return ret; | |
881 | } | |
882 | } | |
883 | } | |
388a0bc7 | 884 | else if (TREE_CODE (rhs) == CONSTRUCTOR |
885 | && TREE_CODE (TREE_TYPE (rhs)) == VECTOR_TYPE | |
886 | && (CONSTRUCTOR_NELTS (rhs) | |
887 | == TYPE_VECTOR_SUBPARTS (TREE_TYPE (rhs)))) | |
888 | { | |
889 | unsigned i; | |
890 | tree val, list; | |
891 | ||
892 | list = NULL_TREE; | |
893 | FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (rhs), i, val) | |
894 | { | |
15d138c9 | 895 | val = valueize_op (val); |
388a0bc7 | 896 | if (TREE_CODE (val) == INTEGER_CST |
897 | || TREE_CODE (val) == REAL_CST | |
898 | || TREE_CODE (val) == FIXED_CST) | |
899 | list = tree_cons (NULL_TREE, val, list); | |
900 | else | |
901 | return NULL_TREE; | |
902 | } | |
903 | ||
904 | return build_vector (TREE_TYPE (rhs), nreverse (list)); | |
905 | } | |
4ee9c684 | 906 | |
75a70cf9 | 907 | if (kind == tcc_reference) |
3e4be816 | 908 | { |
0fefde02 | 909 | if ((TREE_CODE (rhs) == VIEW_CONVERT_EXPR |
910 | || TREE_CODE (rhs) == REALPART_EXPR | |
911 | || TREE_CODE (rhs) == IMAGPART_EXPR) | |
3e4be816 | 912 | && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME) |
913 | { | |
15d138c9 | 914 | tree val = get_constant_value (TREE_OPERAND (rhs, 0)); |
915 | if (val) | |
389dd41b | 916 | return fold_unary_loc (EXPR_LOCATION (rhs), |
15d138c9 | 917 | TREE_CODE (rhs), |
918 | TREE_TYPE (rhs), val); | |
3e4be816 | 919 | } |
182cf5a9 | 920 | else if (TREE_CODE (rhs) == MEM_REF |
8edeb88b | 921 | && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME) |
922 | { | |
15d138c9 | 923 | tree val = get_constant_value (TREE_OPERAND (rhs, 0)); |
924 | if (val | |
925 | && TREE_CODE (val) == ADDR_EXPR) | |
182cf5a9 | 926 | { |
927 | tree tem = fold_build2 (MEM_REF, TREE_TYPE (rhs), | |
15d138c9 | 928 | unshare_expr (val), |
182cf5a9 | 929 | TREE_OPERAND (rhs, 1)); |
930 | if (tem) | |
931 | rhs = tem; | |
932 | } | |
8edeb88b | 933 | } |
3e4be816 | 934 | return fold_const_aggregate_ref (rhs); |
935 | } | |
75a70cf9 | 936 | else if (kind == tcc_declaration) |
937 | return get_symbol_constant_value (rhs); | |
938 | return rhs; | |
939 | } | |
48e1416a | 940 | |
75a70cf9 | 941 | case GIMPLE_UNARY_RHS: |
942 | { | |
943 | /* Handle unary operators that can appear in GIMPLE form. | |
944 | Note that we know the single operand must be a constant, | |
945 | so this should almost always return a simplified RHS. */ | |
946 | tree lhs = gimple_assign_lhs (stmt); | |
15d138c9 | 947 | tree op0 = valueize_op (gimple_assign_rhs1 (stmt)); |
75a70cf9 | 948 | |
949 | /* Conversions are useless for CCP purposes if they are | |
950 | value-preserving. Thus the restrictions that | |
951 | useless_type_conversion_p places for pointer type conversions | |
952 | do not apply here. Substitution later will only substitute to | |
953 | allowed places. */ | |
d9659041 | 954 | if (CONVERT_EXPR_CODE_P (subcode) |
5768aeb3 | 955 | && POINTER_TYPE_P (TREE_TYPE (lhs)) |
182cf5a9 | 956 | && POINTER_TYPE_P (TREE_TYPE (op0))) |
5768aeb3 | 957 | { |
958 | tree tem; | |
182cf5a9 | 959 | /* Try to re-construct array references on-the-fly. */ |
5768aeb3 | 960 | if (!useless_type_conversion_p (TREE_TYPE (lhs), |
961 | TREE_TYPE (op0)) | |
962 | && ((tem = maybe_fold_offset_to_address | |
389dd41b | 963 | (loc, |
e60a6f7b | 964 | op0, integer_zero_node, TREE_TYPE (lhs))) |
5768aeb3 | 965 | != NULL_TREE)) |
966 | return tem; | |
967 | return op0; | |
968 | } | |
75a70cf9 | 969 | |
48e1416a | 970 | return |
389dd41b | 971 | fold_unary_ignore_overflow_loc (loc, subcode, |
972 | gimple_expr_type (stmt), op0); | |
f1fb2997 | 973 | } |
75a70cf9 | 974 | |
975 | case GIMPLE_BINARY_RHS: | |
976 | { | |
977 | /* Handle binary operators that can appear in GIMPLE form. */ | |
15d138c9 | 978 | tree op0 = valueize_op (gimple_assign_rhs1 (stmt)); |
979 | tree op1 = valueize_op (gimple_assign_rhs2 (stmt)); | |
75a70cf9 | 980 | |
182cf5a9 | 981 | /* Translate &x + CST into an invariant form suitable for |
982 | further propagation. */ | |
5768aeb3 | 983 | if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR |
984 | && TREE_CODE (op0) == ADDR_EXPR | |
985 | && TREE_CODE (op1) == INTEGER_CST) | |
986 | { | |
182cf5a9 | 987 | tree off = fold_convert (ptr_type_node, op1); |
988 | return build_fold_addr_expr | |
989 | (fold_build2 (MEM_REF, | |
990 | TREE_TYPE (TREE_TYPE (op0)), | |
991 | unshare_expr (op0), off)); | |
5768aeb3 | 992 | } |
993 | ||
389dd41b | 994 | return fold_binary_loc (loc, subcode, |
182cf5a9 | 995 | gimple_expr_type (stmt), op0, op1); |
75a70cf9 | 996 | } |
997 | ||
00f4f705 | 998 | case GIMPLE_TERNARY_RHS: |
999 | { | |
15d138c9 | 1000 | /* Handle ternary operators that can appear in GIMPLE form. */ |
1001 | tree op0 = valueize_op (gimple_assign_rhs1 (stmt)); | |
1002 | tree op1 = valueize_op (gimple_assign_rhs2 (stmt)); | |
1003 | tree op2 = valueize_op (gimple_assign_rhs3 (stmt)); | |
00f4f705 | 1004 | |
1005 | return fold_ternary_loc (loc, subcode, | |
1006 | gimple_expr_type (stmt), op0, op1, op2); | |
1007 | } | |
1008 | ||
75a70cf9 | 1009 | default: |
1010 | gcc_unreachable (); | |
1011 | } | |
1012 | } | |
1013 | break; | |
4ee9c684 | 1014 | |
75a70cf9 | 1015 | case GIMPLE_CALL: |
f257af64 | 1016 | { |
15d138c9 | 1017 | tree fn = valueize_op (gimple_call_fn (stmt)); |
f257af64 | 1018 | if (TREE_CODE (fn) == ADDR_EXPR |
8ef4f124 | 1019 | && TREE_CODE (TREE_OPERAND (fn, 0)) == FUNCTION_DECL |
f257af64 | 1020 | && DECL_BUILT_IN (TREE_OPERAND (fn, 0))) |
1021 | { | |
1022 | tree *args = XALLOCAVEC (tree, gimple_call_num_args (stmt)); | |
1023 | tree call, retval; | |
1024 | unsigned i; | |
1025 | for (i = 0; i < gimple_call_num_args (stmt); ++i) | |
15d138c9 | 1026 | args[i] = valueize_op (gimple_call_arg (stmt, i)); |
389dd41b | 1027 | call = build_call_array_loc (loc, |
1028 | gimple_call_return_type (stmt), | |
1029 | fn, gimple_call_num_args (stmt), args); | |
1030 | retval = fold_call_expr (EXPR_LOCATION (call), call, false); | |
f257af64 | 1031 | if (retval) |
1032 | /* fold_call_expr wraps the result inside a NOP_EXPR. */ | |
1033 | STRIP_NOPS (retval); | |
1034 | return retval; | |
1035 | } | |
1036 | return NULL_TREE; | |
1037 | } | |
4ee9c684 | 1038 | |
75a70cf9 | 1039 | case GIMPLE_COND: |
1040 | { | |
1041 | /* Handle comparison operators that can appear in GIMPLE form. */ | |
15d138c9 | 1042 | tree op0 = valueize_op (gimple_cond_lhs (stmt)); |
1043 | tree op1 = valueize_op (gimple_cond_rhs (stmt)); | |
75a70cf9 | 1044 | enum tree_code code = gimple_cond_code (stmt); |
389dd41b | 1045 | return fold_binary_loc (loc, code, boolean_type_node, op0, op1); |
75a70cf9 | 1046 | } |
4ee9c684 | 1047 | |
75a70cf9 | 1048 | case GIMPLE_SWITCH: |
1049 | { | |
15d138c9 | 1050 | /* Return the constant switch index. */ |
1051 | return valueize_op (gimple_switch_index (stmt)); | |
75a70cf9 | 1052 | } |
912f109f | 1053 | |
75a70cf9 | 1054 | default: |
1055 | gcc_unreachable (); | |
4ee9c684 | 1056 | } |
4ee9c684 | 1057 | } |
1058 | ||
8782adcf | 1059 | /* Return the tree representing the element referenced by T if T is an |
1060 | ARRAY_REF or COMPONENT_REF into constant aggregates. Return | |
1061 | NULL_TREE otherwise. */ | |
1062 | ||
e004838d | 1063 | tree |
8782adcf | 1064 | fold_const_aggregate_ref (tree t) |
1065 | { | |
c75b4594 | 1066 | tree base, ctor, idx, field; |
1067 | unsigned HOST_WIDE_INT cnt; | |
1068 | tree cfield, cval; | |
15d138c9 | 1069 | tree tem; |
8782adcf | 1070 | |
8edeb88b | 1071 | if (TREE_CODE_CLASS (TREE_CODE (t)) == tcc_declaration) |
1072 | return get_symbol_constant_value (t); | |
1073 | ||
8782adcf | 1074 | switch (TREE_CODE (t)) |
1075 | { | |
1076 | case ARRAY_REF: | |
1077 | /* Get a CONSTRUCTOR. If BASE is a VAR_DECL, get its | |
1078 | DECL_INITIAL. If BASE is a nested reference into another | |
1079 | ARRAY_REF or COMPONENT_REF, make a recursive call to resolve | |
1080 | the inner reference. */ | |
1081 | base = TREE_OPERAND (t, 0); | |
1082 | switch (TREE_CODE (base)) | |
1083 | { | |
1c196c04 | 1084 | case MEM_REF: |
1085 | /* ??? We could handle this case. */ | |
1086 | if (!integer_zerop (TREE_OPERAND (base, 1))) | |
1087 | return NULL_TREE; | |
1088 | base = get_base_address (base); | |
1089 | if (!base | |
1090 | || TREE_CODE (base) != VAR_DECL) | |
1091 | return NULL_TREE; | |
1092 | ||
1093 | /* Fallthru. */ | |
8782adcf | 1094 | case VAR_DECL: |
1095 | if (!TREE_READONLY (base) | |
1096 | || TREE_CODE (TREE_TYPE (base)) != ARRAY_TYPE | |
1097 | || !targetm.binds_local_p (base)) | |
1098 | return NULL_TREE; | |
1099 | ||
1100 | ctor = DECL_INITIAL (base); | |
1101 | break; | |
1102 | ||
1103 | case ARRAY_REF: | |
1104 | case COMPONENT_REF: | |
1105 | ctor = fold_const_aggregate_ref (base); | |
1106 | break; | |
1107 | ||
04236c3a | 1108 | case STRING_CST: |
1109 | case CONSTRUCTOR: | |
1110 | ctor = base; | |
1111 | break; | |
1112 | ||
8782adcf | 1113 | default: |
1114 | return NULL_TREE; | |
1115 | } | |
1116 | ||
1117 | if (ctor == NULL_TREE | |
4f61cce6 | 1118 | || (TREE_CODE (ctor) != CONSTRUCTOR |
1119 | && TREE_CODE (ctor) != STRING_CST) | |
8782adcf | 1120 | || !TREE_STATIC (ctor)) |
1121 | return NULL_TREE; | |
1122 | ||
1123 | /* Get the index. If we have an SSA_NAME, try to resolve it | |
1124 | with the current lattice value for the SSA_NAME. */ | |
1125 | idx = TREE_OPERAND (t, 1); | |
1126 | switch (TREE_CODE (idx)) | |
1127 | { | |
1128 | case SSA_NAME: | |
15d138c9 | 1129 | if ((tem = get_constant_value (idx)) |
1130 | && TREE_CODE (tem) == INTEGER_CST) | |
1131 | idx = tem; | |
8782adcf | 1132 | else |
1133 | return NULL_TREE; | |
1134 | break; | |
1135 | ||
1136 | case INTEGER_CST: | |
1137 | break; | |
1138 | ||
1139 | default: | |
1140 | return NULL_TREE; | |
1141 | } | |
1142 | ||
4f61cce6 | 1143 | /* Fold read from constant string. */ |
1144 | if (TREE_CODE (ctor) == STRING_CST) | |
1145 | { | |
1146 | if ((TYPE_MODE (TREE_TYPE (t)) | |
1147 | == TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) | |
1148 | && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) | |
1149 | == MODE_INT) | |
1150 | && GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) == 1 | |
1151 | && compare_tree_int (idx, TREE_STRING_LENGTH (ctor)) < 0) | |
7b050b7b | 1152 | return build_int_cst_type (TREE_TYPE (t), |
1153 | (TREE_STRING_POINTER (ctor) | |
1154 | [TREE_INT_CST_LOW (idx)])); | |
4f61cce6 | 1155 | return NULL_TREE; |
1156 | } | |
1157 | ||
8782adcf | 1158 | /* Whoo-hoo! I'll fold ya baby. Yeah! */ |
c75b4594 | 1159 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, cval) |
1160 | if (tree_int_cst_equal (cfield, idx)) | |
590d65aa | 1161 | { |
6872bf3c | 1162 | STRIP_NOPS (cval); |
3a44a278 | 1163 | if (TREE_CODE (cval) == ADDR_EXPR) |
1164 | { | |
1165 | tree base = get_base_address (TREE_OPERAND (cval, 0)); | |
1166 | if (base && TREE_CODE (base) == VAR_DECL) | |
1167 | add_referenced_var (base); | |
1168 | } | |
590d65aa | 1169 | return cval; |
1170 | } | |
8782adcf | 1171 | break; |
1172 | ||
1173 | case COMPONENT_REF: | |
1174 | /* Get a CONSTRUCTOR. If BASE is a VAR_DECL, get its | |
1175 | DECL_INITIAL. If BASE is a nested reference into another | |
1176 | ARRAY_REF or COMPONENT_REF, make a recursive call to resolve | |
1177 | the inner reference. */ | |
1178 | base = TREE_OPERAND (t, 0); | |
1179 | switch (TREE_CODE (base)) | |
1180 | { | |
1181 | case VAR_DECL: | |
1182 | if (!TREE_READONLY (base) | |
1183 | || TREE_CODE (TREE_TYPE (base)) != RECORD_TYPE | |
1184 | || !targetm.binds_local_p (base)) | |
1185 | return NULL_TREE; | |
1186 | ||
1187 | ctor = DECL_INITIAL (base); | |
1188 | break; | |
1189 | ||
1190 | case ARRAY_REF: | |
1191 | case COMPONENT_REF: | |
1192 | ctor = fold_const_aggregate_ref (base); | |
1193 | break; | |
1194 | ||
1195 | default: | |
1196 | return NULL_TREE; | |
1197 | } | |
1198 | ||
1199 | if (ctor == NULL_TREE | |
1200 | || TREE_CODE (ctor) != CONSTRUCTOR | |
1201 | || !TREE_STATIC (ctor)) | |
1202 | return NULL_TREE; | |
1203 | ||
1204 | field = TREE_OPERAND (t, 1); | |
1205 | ||
c75b4594 | 1206 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, cval) |
1207 | if (cfield == field | |
8782adcf | 1208 | /* FIXME: Handle bit-fields. */ |
c75b4594 | 1209 | && ! DECL_BIT_FIELD (cfield)) |
590d65aa | 1210 | { |
6872bf3c | 1211 | STRIP_NOPS (cval); |
3a44a278 | 1212 | if (TREE_CODE (cval) == ADDR_EXPR) |
1213 | { | |
1214 | tree base = get_base_address (TREE_OPERAND (cval, 0)); | |
1215 | if (base && TREE_CODE (base) == VAR_DECL) | |
1216 | add_referenced_var (base); | |
1217 | } | |
590d65aa | 1218 | return cval; |
1219 | } | |
8782adcf | 1220 | break; |
1221 | ||
908cb59d | 1222 | case REALPART_EXPR: |
1223 | case IMAGPART_EXPR: | |
1224 | { | |
1225 | tree c = fold_const_aggregate_ref (TREE_OPERAND (t, 0)); | |
1226 | if (c && TREE_CODE (c) == COMPLEX_CST) | |
389dd41b | 1227 | return fold_build1_loc (EXPR_LOCATION (t), |
1228 | TREE_CODE (t), TREE_TYPE (t), c); | |
908cb59d | 1229 | break; |
1230 | } | |
04236c3a | 1231 | |
182cf5a9 | 1232 | case MEM_REF: |
1233 | /* Get the base object we are accessing. */ | |
1234 | base = TREE_OPERAND (t, 0); | |
1235 | if (TREE_CODE (base) == SSA_NAME | |
15d138c9 | 1236 | && (tem = get_constant_value (base))) |
1237 | base = tem; | |
182cf5a9 | 1238 | if (TREE_CODE (base) != ADDR_EXPR) |
1239 | return NULL_TREE; | |
1240 | base = TREE_OPERAND (base, 0); | |
1241 | switch (TREE_CODE (base)) | |
1242 | { | |
1243 | case VAR_DECL: | |
1244 | if (DECL_P (base) | |
1245 | && !AGGREGATE_TYPE_P (TREE_TYPE (base)) | |
1246 | && integer_zerop (TREE_OPERAND (t, 1))) | |
dbeb5fe0 | 1247 | { |
1248 | tree res = get_symbol_constant_value (base); | |
1249 | if (res | |
1250 | && !useless_type_conversion_p | |
1251 | (TREE_TYPE (t), TREE_TYPE (res))) | |
1252 | res = fold_unary (VIEW_CONVERT_EXPR, TREE_TYPE (t), res); | |
1253 | return res; | |
1254 | } | |
182cf5a9 | 1255 | |
1256 | if (!TREE_READONLY (base) | |
1257 | || TREE_CODE (TREE_TYPE (base)) != ARRAY_TYPE | |
1258 | || !targetm.binds_local_p (base)) | |
1259 | return NULL_TREE; | |
1260 | ||
1261 | ctor = DECL_INITIAL (base); | |
1262 | break; | |
1263 | ||
1264 | case STRING_CST: | |
1265 | case CONSTRUCTOR: | |
1266 | ctor = base; | |
1267 | break; | |
1268 | ||
1269 | default: | |
1270 | return NULL_TREE; | |
1271 | } | |
1272 | ||
1273 | if (ctor == NULL_TREE | |
1274 | || (TREE_CODE (ctor) != CONSTRUCTOR | |
1275 | && TREE_CODE (ctor) != STRING_CST) | |
1276 | || !TREE_STATIC (ctor)) | |
1277 | return NULL_TREE; | |
1278 | ||
1279 | /* Get the byte offset. */ | |
1280 | idx = TREE_OPERAND (t, 1); | |
1281 | ||
1282 | /* Fold read from constant string. */ | |
1283 | if (TREE_CODE (ctor) == STRING_CST) | |
1284 | { | |
1285 | if ((TYPE_MODE (TREE_TYPE (t)) | |
1286 | == TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) | |
1287 | && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) | |
1288 | == MODE_INT) | |
1289 | && GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) == 1 | |
1290 | && compare_tree_int (idx, TREE_STRING_LENGTH (ctor)) < 0) | |
1291 | return build_int_cst_type (TREE_TYPE (t), | |
1292 | (TREE_STRING_POINTER (ctor) | |
1293 | [TREE_INT_CST_LOW (idx)])); | |
1294 | return NULL_TREE; | |
1295 | } | |
1296 | ||
1297 | /* ??? Implement byte-offset indexing into a non-array CONSTRUCTOR. */ | |
1298 | if (TREE_CODE (TREE_TYPE (ctor)) == ARRAY_TYPE | |
1299 | && (TYPE_MODE (TREE_TYPE (t)) | |
1300 | == TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) | |
1301 | && GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (t))) != 0 | |
1302 | && integer_zerop | |
1303 | (int_const_binop | |
1304 | (TRUNC_MOD_EXPR, idx, | |
1305 | size_int (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (t)))), 0))) | |
1306 | { | |
1307 | idx = int_const_binop (TRUNC_DIV_EXPR, idx, | |
1308 | size_int (GET_MODE_SIZE | |
1309 | (TYPE_MODE (TREE_TYPE (t)))), 0); | |
1310 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, cval) | |
1311 | if (tree_int_cst_equal (cfield, idx)) | |
1312 | { | |
1313 | STRIP_NOPS (cval); | |
1314 | if (TREE_CODE (cval) == ADDR_EXPR) | |
1315 | { | |
1316 | tree base = get_base_address (TREE_OPERAND (cval, 0)); | |
1317 | if (base && TREE_CODE (base) == VAR_DECL) | |
1318 | add_referenced_var (base); | |
1319 | } | |
1320 | if (useless_type_conversion_p (TREE_TYPE (t), TREE_TYPE (cval))) | |
1321 | return cval; | |
1322 | else if (CONSTANT_CLASS_P (cval)) | |
1323 | return fold_build1 (VIEW_CONVERT_EXPR, TREE_TYPE (t), cval); | |
1324 | else | |
1325 | return NULL_TREE; | |
1326 | } | |
1327 | } | |
1328 | break; | |
04236c3a | 1329 | |
8782adcf | 1330 | default: |
1331 | break; | |
1332 | } | |
1333 | ||
1334 | return NULL_TREE; | |
1335 | } | |
75a70cf9 | 1336 | |
1337 | /* Evaluate statement STMT. | |
1338 | Valid only for assignments, calls, conditionals, and switches. */ | |
4ee9c684 | 1339 | |
88dbf20f | 1340 | static prop_value_t |
75a70cf9 | 1341 | evaluate_stmt (gimple stmt) |
4ee9c684 | 1342 | { |
88dbf20f | 1343 | prop_value_t val; |
4f61cce6 | 1344 | tree simplified = NULL_TREE; |
88dbf20f | 1345 | ccp_lattice_t likelyvalue = likely_value (stmt); |
add6ee5e | 1346 | bool is_constant; |
88dbf20f | 1347 | |
add6ee5e | 1348 | fold_defer_overflow_warnings (); |
1349 | ||
4ee9c684 | 1350 | /* If the statement is likely to have a CONSTANT result, then try |
1351 | to fold the statement to determine the constant value. */ | |
75a70cf9 | 1352 | /* FIXME. This is the only place that we call ccp_fold. |
1353 | Since likely_value never returns CONSTANT for calls, we will | |
1354 | not attempt to fold them, including builtins that may profit. */ | |
4ee9c684 | 1355 | if (likelyvalue == CONSTANT) |
1356 | simplified = ccp_fold (stmt); | |
1357 | /* If the statement is likely to have a VARYING result, then do not | |
1358 | bother folding the statement. */ | |
04236c3a | 1359 | else if (likelyvalue == VARYING) |
75a70cf9 | 1360 | { |
590c3166 | 1361 | enum gimple_code code = gimple_code (stmt); |
75a70cf9 | 1362 | if (code == GIMPLE_ASSIGN) |
1363 | { | |
1364 | enum tree_code subcode = gimple_assign_rhs_code (stmt); | |
48e1416a | 1365 | |
75a70cf9 | 1366 | /* Other cases cannot satisfy is_gimple_min_invariant |
1367 | without folding. */ | |
1368 | if (get_gimple_rhs_class (subcode) == GIMPLE_SINGLE_RHS) | |
1369 | simplified = gimple_assign_rhs1 (stmt); | |
1370 | } | |
1371 | else if (code == GIMPLE_SWITCH) | |
1372 | simplified = gimple_switch_index (stmt); | |
1373 | else | |
a65c4d64 | 1374 | /* These cannot satisfy is_gimple_min_invariant without folding. */ |
1375 | gcc_assert (code == GIMPLE_CALL || code == GIMPLE_COND); | |
75a70cf9 | 1376 | } |
4ee9c684 | 1377 | |
add6ee5e | 1378 | is_constant = simplified && is_gimple_min_invariant (simplified); |
1379 | ||
1380 | fold_undefer_overflow_warnings (is_constant, stmt, 0); | |
1381 | ||
912f109f | 1382 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1383 | { | |
1384 | fprintf (dump_file, "which is likely "); | |
1385 | switch (likelyvalue) | |
1386 | { | |
1387 | case CONSTANT: | |
1388 | fprintf (dump_file, "CONSTANT"); | |
1389 | break; | |
1390 | case UNDEFINED: | |
1391 | fprintf (dump_file, "UNDEFINED"); | |
1392 | break; | |
1393 | case VARYING: | |
1394 | fprintf (dump_file, "VARYING"); | |
1395 | break; | |
1396 | default:; | |
1397 | } | |
1398 | fprintf (dump_file, "\n"); | |
1399 | } | |
1400 | ||
add6ee5e | 1401 | if (is_constant) |
4ee9c684 | 1402 | { |
1403 | /* The statement produced a constant value. */ | |
1404 | val.lattice_val = CONSTANT; | |
88dbf20f | 1405 | val.value = simplified; |
4ee9c684 | 1406 | } |
1407 | else | |
1408 | { | |
1409 | /* The statement produced a nonconstant value. If the statement | |
88dbf20f | 1410 | had UNDEFINED operands, then the result of the statement |
1411 | should be UNDEFINED. Otherwise, the statement is VARYING. */ | |
bfa30570 | 1412 | if (likelyvalue == UNDEFINED) |
b765fa12 | 1413 | val.lattice_val = likelyvalue; |
1414 | else | |
1415 | val.lattice_val = VARYING; | |
1416 | ||
88dbf20f | 1417 | val.value = NULL_TREE; |
4ee9c684 | 1418 | } |
41511585 | 1419 | |
1420 | return val; | |
4ee9c684 | 1421 | } |
1422 | ||
6688f8ec | 1423 | /* Fold the stmt at *GSI with CCP specific information that propagating |
1424 | and regular folding does not catch. */ | |
1425 | ||
1426 | static bool | |
1427 | ccp_fold_stmt (gimple_stmt_iterator *gsi) | |
1428 | { | |
1429 | gimple stmt = gsi_stmt (*gsi); | |
6688f8ec | 1430 | |
94144e68 | 1431 | switch (gimple_code (stmt)) |
1432 | { | |
1433 | case GIMPLE_COND: | |
1434 | { | |
1435 | prop_value_t val; | |
1436 | /* Statement evaluation will handle type mismatches in constants | |
1437 | more gracefully than the final propagation. This allows us to | |
1438 | fold more conditionals here. */ | |
1439 | val = evaluate_stmt (stmt); | |
1440 | if (val.lattice_val != CONSTANT | |
1441 | || TREE_CODE (val.value) != INTEGER_CST) | |
1442 | return false; | |
1443 | ||
1444 | if (integer_zerop (val.value)) | |
1445 | gimple_cond_make_false (stmt); | |
1446 | else | |
1447 | gimple_cond_make_true (stmt); | |
6688f8ec | 1448 | |
94144e68 | 1449 | return true; |
1450 | } | |
6688f8ec | 1451 | |
94144e68 | 1452 | case GIMPLE_CALL: |
1453 | { | |
1454 | tree lhs = gimple_call_lhs (stmt); | |
15d138c9 | 1455 | tree val; |
94144e68 | 1456 | tree argt; |
1457 | bool changed = false; | |
1458 | unsigned i; | |
1459 | ||
1460 | /* If the call was folded into a constant make sure it goes | |
1461 | away even if we cannot propagate into all uses because of | |
1462 | type issues. */ | |
1463 | if (lhs | |
1464 | && TREE_CODE (lhs) == SSA_NAME | |
15d138c9 | 1465 | && (val = get_constant_value (lhs))) |
94144e68 | 1466 | { |
15d138c9 | 1467 | tree new_rhs = unshare_expr (val); |
338cce8f | 1468 | bool res; |
94144e68 | 1469 | if (!useless_type_conversion_p (TREE_TYPE (lhs), |
1470 | TREE_TYPE (new_rhs))) | |
1471 | new_rhs = fold_convert (TREE_TYPE (lhs), new_rhs); | |
338cce8f | 1472 | res = update_call_from_tree (gsi, new_rhs); |
1473 | gcc_assert (res); | |
94144e68 | 1474 | return true; |
1475 | } | |
1476 | ||
1477 | /* Propagate into the call arguments. Compared to replace_uses_in | |
1478 | this can use the argument slot types for type verification | |
1479 | instead of the current argument type. We also can safely | |
1480 | drop qualifiers here as we are dealing with constants anyway. */ | |
1481 | argt = TYPE_ARG_TYPES (TREE_TYPE (TREE_TYPE (gimple_call_fn (stmt)))); | |
1482 | for (i = 0; i < gimple_call_num_args (stmt) && argt; | |
1483 | ++i, argt = TREE_CHAIN (argt)) | |
1484 | { | |
1485 | tree arg = gimple_call_arg (stmt, i); | |
1486 | if (TREE_CODE (arg) == SSA_NAME | |
15d138c9 | 1487 | && (val = get_constant_value (arg)) |
94144e68 | 1488 | && useless_type_conversion_p |
1489 | (TYPE_MAIN_VARIANT (TREE_VALUE (argt)), | |
15d138c9 | 1490 | TYPE_MAIN_VARIANT (TREE_TYPE (val)))) |
94144e68 | 1491 | { |
15d138c9 | 1492 | gimple_call_set_arg (stmt, i, unshare_expr (val)); |
94144e68 | 1493 | changed = true; |
1494 | } | |
1495 | } | |
1496 | ||
1497 | return changed; | |
1498 | } | |
6688f8ec | 1499 | |
6872bf3c | 1500 | case GIMPLE_ASSIGN: |
1501 | { | |
1502 | tree lhs = gimple_assign_lhs (stmt); | |
15d138c9 | 1503 | tree val; |
6872bf3c | 1504 | |
1505 | /* If we have a load that turned out to be constant replace it | |
1506 | as we cannot propagate into all uses in all cases. */ | |
1507 | if (gimple_assign_single_p (stmt) | |
1508 | && TREE_CODE (lhs) == SSA_NAME | |
15d138c9 | 1509 | && (val = get_constant_value (lhs))) |
6872bf3c | 1510 | { |
15d138c9 | 1511 | tree rhs = unshare_expr (val); |
6872bf3c | 1512 | if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs))) |
182cf5a9 | 1513 | rhs = fold_build1 (VIEW_CONVERT_EXPR, TREE_TYPE (lhs), rhs); |
6872bf3c | 1514 | gimple_assign_set_rhs_from_tree (gsi, rhs); |
1515 | return true; | |
1516 | } | |
1517 | ||
1518 | return false; | |
1519 | } | |
1520 | ||
94144e68 | 1521 | default: |
1522 | return false; | |
1523 | } | |
6688f8ec | 1524 | } |
1525 | ||
41511585 | 1526 | /* Visit the assignment statement STMT. Set the value of its LHS to the |
88dbf20f | 1527 | value computed by the RHS and store LHS in *OUTPUT_P. If STMT |
1528 | creates virtual definitions, set the value of each new name to that | |
75a70cf9 | 1529 | of the RHS (if we can derive a constant out of the RHS). |
1530 | Value-returning call statements also perform an assignment, and | |
1531 | are handled here. */ | |
4ee9c684 | 1532 | |
41511585 | 1533 | static enum ssa_prop_result |
75a70cf9 | 1534 | visit_assignment (gimple stmt, tree *output_p) |
4ee9c684 | 1535 | { |
88dbf20f | 1536 | prop_value_t val; |
88dbf20f | 1537 | enum ssa_prop_result retval; |
4ee9c684 | 1538 | |
75a70cf9 | 1539 | tree lhs = gimple_get_lhs (stmt); |
4ee9c684 | 1540 | |
75a70cf9 | 1541 | gcc_assert (gimple_code (stmt) != GIMPLE_CALL |
1542 | || gimple_call_lhs (stmt) != NULL_TREE); | |
1543 | ||
15d138c9 | 1544 | if (gimple_assign_single_p (stmt) |
1545 | && gimple_assign_rhs_code (stmt) == SSA_NAME) | |
1546 | /* For a simple copy operation, we copy the lattice values. */ | |
1547 | val = *get_value (gimple_assign_rhs1 (stmt)); | |
41511585 | 1548 | else |
75a70cf9 | 1549 | /* Evaluate the statement, which could be |
1550 | either a GIMPLE_ASSIGN or a GIMPLE_CALL. */ | |
04236c3a | 1551 | val = evaluate_stmt (stmt); |
4ee9c684 | 1552 | |
88dbf20f | 1553 | retval = SSA_PROP_NOT_INTERESTING; |
4ee9c684 | 1554 | |
41511585 | 1555 | /* Set the lattice value of the statement's output. */ |
88dbf20f | 1556 | if (TREE_CODE (lhs) == SSA_NAME) |
4ee9c684 | 1557 | { |
88dbf20f | 1558 | /* If STMT is an assignment to an SSA_NAME, we only have one |
1559 | value to set. */ | |
1560 | if (set_lattice_value (lhs, val)) | |
1561 | { | |
1562 | *output_p = lhs; | |
1563 | if (val.lattice_val == VARYING) | |
1564 | retval = SSA_PROP_VARYING; | |
1565 | else | |
1566 | retval = SSA_PROP_INTERESTING; | |
1567 | } | |
4ee9c684 | 1568 | } |
88dbf20f | 1569 | |
1570 | return retval; | |
4ee9c684 | 1571 | } |
1572 | ||
4ee9c684 | 1573 | |
41511585 | 1574 | /* Visit the conditional statement STMT. Return SSA_PROP_INTERESTING |
1575 | if it can determine which edge will be taken. Otherwise, return | |
1576 | SSA_PROP_VARYING. */ | |
1577 | ||
1578 | static enum ssa_prop_result | |
75a70cf9 | 1579 | visit_cond_stmt (gimple stmt, edge *taken_edge_p) |
4ee9c684 | 1580 | { |
88dbf20f | 1581 | prop_value_t val; |
41511585 | 1582 | basic_block block; |
1583 | ||
75a70cf9 | 1584 | block = gimple_bb (stmt); |
41511585 | 1585 | val = evaluate_stmt (stmt); |
1586 | ||
1587 | /* Find which edge out of the conditional block will be taken and add it | |
1588 | to the worklist. If no single edge can be determined statically, | |
1589 | return SSA_PROP_VARYING to feed all the outgoing edges to the | |
1590 | propagation engine. */ | |
88dbf20f | 1591 | *taken_edge_p = val.value ? find_taken_edge (block, val.value) : 0; |
41511585 | 1592 | if (*taken_edge_p) |
1593 | return SSA_PROP_INTERESTING; | |
1594 | else | |
1595 | return SSA_PROP_VARYING; | |
4ee9c684 | 1596 | } |
1597 | ||
4ee9c684 | 1598 | |
41511585 | 1599 | /* Evaluate statement STMT. If the statement produces an output value and |
1600 | its evaluation changes the lattice value of its output, return | |
1601 | SSA_PROP_INTERESTING and set *OUTPUT_P to the SSA_NAME holding the | |
1602 | output value. | |
48e1416a | 1603 | |
41511585 | 1604 | If STMT is a conditional branch and we can determine its truth |
1605 | value, set *TAKEN_EDGE_P accordingly. If STMT produces a varying | |
1606 | value, return SSA_PROP_VARYING. */ | |
4ee9c684 | 1607 | |
41511585 | 1608 | static enum ssa_prop_result |
75a70cf9 | 1609 | ccp_visit_stmt (gimple stmt, edge *taken_edge_p, tree *output_p) |
41511585 | 1610 | { |
41511585 | 1611 | tree def; |
1612 | ssa_op_iter iter; | |
4ee9c684 | 1613 | |
41511585 | 1614 | if (dump_file && (dump_flags & TDF_DETAILS)) |
4ee9c684 | 1615 | { |
88dbf20f | 1616 | fprintf (dump_file, "\nVisiting statement:\n"); |
75a70cf9 | 1617 | print_gimple_stmt (dump_file, stmt, 0, dump_flags); |
4ee9c684 | 1618 | } |
4ee9c684 | 1619 | |
75a70cf9 | 1620 | switch (gimple_code (stmt)) |
4ee9c684 | 1621 | { |
75a70cf9 | 1622 | case GIMPLE_ASSIGN: |
1623 | /* If the statement is an assignment that produces a single | |
1624 | output value, evaluate its RHS to see if the lattice value of | |
1625 | its output has changed. */ | |
1626 | return visit_assignment (stmt, output_p); | |
1627 | ||
1628 | case GIMPLE_CALL: | |
1629 | /* A value-returning call also performs an assignment. */ | |
1630 | if (gimple_call_lhs (stmt) != NULL_TREE) | |
1631 | return visit_assignment (stmt, output_p); | |
1632 | break; | |
1633 | ||
1634 | case GIMPLE_COND: | |
1635 | case GIMPLE_SWITCH: | |
1636 | /* If STMT is a conditional branch, see if we can determine | |
1637 | which branch will be taken. */ | |
1638 | /* FIXME. It appears that we should be able to optimize | |
1639 | computed GOTOs here as well. */ | |
1640 | return visit_cond_stmt (stmt, taken_edge_p); | |
1641 | ||
1642 | default: | |
1643 | break; | |
4ee9c684 | 1644 | } |
4ee9c684 | 1645 | |
41511585 | 1646 | /* Any other kind of statement is not interesting for constant |
1647 | propagation and, therefore, not worth simulating. */ | |
41511585 | 1648 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1649 | fprintf (dump_file, "No interesting values produced. Marked VARYING.\n"); | |
4ee9c684 | 1650 | |
41511585 | 1651 | /* Definitions made by statements other than assignments to |
1652 | SSA_NAMEs represent unknown modifications to their outputs. | |
1653 | Mark them VARYING. */ | |
88dbf20f | 1654 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS) |
1655 | { | |
61207d43 | 1656 | prop_value_t v = { VARYING, NULL_TREE }; |
88dbf20f | 1657 | set_lattice_value (def, v); |
1658 | } | |
4ee9c684 | 1659 | |
41511585 | 1660 | return SSA_PROP_VARYING; |
1661 | } | |
4ee9c684 | 1662 | |
4ee9c684 | 1663 | |
88dbf20f | 1664 | /* Main entry point for SSA Conditional Constant Propagation. */ |
41511585 | 1665 | |
33a34f1e | 1666 | static unsigned int |
61207d43 | 1667 | do_ssa_ccp (void) |
41511585 | 1668 | { |
1669 | ccp_initialize (); | |
1670 | ssa_propagate (ccp_visit_stmt, ccp_visit_phi_node); | |
33a34f1e | 1671 | if (ccp_finalize ()) |
eb9161e7 | 1672 | return (TODO_cleanup_cfg | TODO_update_ssa | TODO_remove_unused_locals); |
33a34f1e | 1673 | else |
1674 | return 0; | |
4ee9c684 | 1675 | } |
1676 | ||
5664499b | 1677 | |
1678 | static bool | |
41511585 | 1679 | gate_ccp (void) |
5664499b | 1680 | { |
41511585 | 1681 | return flag_tree_ccp != 0; |
5664499b | 1682 | } |
1683 | ||
4ee9c684 | 1684 | |
48e1416a | 1685 | struct gimple_opt_pass pass_ccp = |
41511585 | 1686 | { |
20099e35 | 1687 | { |
1688 | GIMPLE_PASS, | |
41511585 | 1689 | "ccp", /* name */ |
1690 | gate_ccp, /* gate */ | |
88dbf20f | 1691 | do_ssa_ccp, /* execute */ |
41511585 | 1692 | NULL, /* sub */ |
1693 | NULL, /* next */ | |
1694 | 0, /* static_pass_number */ | |
1695 | TV_TREE_CCP, /* tv_id */ | |
49290934 | 1696 | PROP_cfg | PROP_ssa, /* properties_required */ |
41511585 | 1697 | 0, /* properties_provided */ |
b6246c40 | 1698 | 0, /* properties_destroyed */ |
41511585 | 1699 | 0, /* todo_flags_start */ |
33a34f1e | 1700 | TODO_dump_func | TODO_verify_ssa |
20099e35 | 1701 | | TODO_verify_stmts | TODO_ggc_collect/* todo_flags_finish */ |
1702 | } | |
41511585 | 1703 | }; |
4ee9c684 | 1704 | |
4ee9c684 | 1705 | |
75a70cf9 | 1706 | |
bdd0e199 | 1707 | /* Try to optimize out __builtin_stack_restore. Optimize it out |
1708 | if there is another __builtin_stack_restore in the same basic | |
1709 | block and no calls or ASM_EXPRs are in between, or if this block's | |
1710 | only outgoing edge is to EXIT_BLOCK and there are no calls or | |
1711 | ASM_EXPRs after this __builtin_stack_restore. */ | |
1712 | ||
1713 | static tree | |
75a70cf9 | 1714 | optimize_stack_restore (gimple_stmt_iterator i) |
bdd0e199 | 1715 | { |
6ea999da | 1716 | tree callee; |
1717 | gimple stmt; | |
75a70cf9 | 1718 | |
1719 | basic_block bb = gsi_bb (i); | |
1720 | gimple call = gsi_stmt (i); | |
bdd0e199 | 1721 | |
75a70cf9 | 1722 | if (gimple_code (call) != GIMPLE_CALL |
1723 | || gimple_call_num_args (call) != 1 | |
1724 | || TREE_CODE (gimple_call_arg (call, 0)) != SSA_NAME | |
1725 | || !POINTER_TYPE_P (TREE_TYPE (gimple_call_arg (call, 0)))) | |
bdd0e199 | 1726 | return NULL_TREE; |
1727 | ||
75a70cf9 | 1728 | for (gsi_next (&i); !gsi_end_p (i); gsi_next (&i)) |
bdd0e199 | 1729 | { |
75a70cf9 | 1730 | stmt = gsi_stmt (i); |
1731 | if (gimple_code (stmt) == GIMPLE_ASM) | |
bdd0e199 | 1732 | return NULL_TREE; |
75a70cf9 | 1733 | if (gimple_code (stmt) != GIMPLE_CALL) |
bdd0e199 | 1734 | continue; |
1735 | ||
75a70cf9 | 1736 | callee = gimple_call_fndecl (stmt); |
c40a6f90 | 1737 | if (!callee |
1738 | || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL | |
1739 | /* All regular builtins are ok, just obviously not alloca. */ | |
1740 | || DECL_FUNCTION_CODE (callee) == BUILT_IN_ALLOCA) | |
bdd0e199 | 1741 | return NULL_TREE; |
1742 | ||
1743 | if (DECL_FUNCTION_CODE (callee) == BUILT_IN_STACK_RESTORE) | |
6ea999da | 1744 | goto second_stack_restore; |
bdd0e199 | 1745 | } |
1746 | ||
6ea999da | 1747 | if (!gsi_end_p (i)) |
bdd0e199 | 1748 | return NULL_TREE; |
1749 | ||
6ea999da | 1750 | /* Allow one successor of the exit block, or zero successors. */ |
1751 | switch (EDGE_COUNT (bb->succs)) | |
1752 | { | |
1753 | case 0: | |
1754 | break; | |
1755 | case 1: | |
1756 | if (single_succ_edge (bb)->dest != EXIT_BLOCK_PTR) | |
1757 | return NULL_TREE; | |
1758 | break; | |
1759 | default: | |
1760 | return NULL_TREE; | |
1761 | } | |
1762 | second_stack_restore: | |
bdd0e199 | 1763 | |
6ea999da | 1764 | /* If there's exactly one use, then zap the call to __builtin_stack_save. |
1765 | If there are multiple uses, then the last one should remove the call. | |
1766 | In any case, whether the call to __builtin_stack_save can be removed | |
1767 | or not is irrelevant to removing the call to __builtin_stack_restore. */ | |
1768 | if (has_single_use (gimple_call_arg (call, 0))) | |
1769 | { | |
1770 | gimple stack_save = SSA_NAME_DEF_STMT (gimple_call_arg (call, 0)); | |
1771 | if (is_gimple_call (stack_save)) | |
1772 | { | |
1773 | callee = gimple_call_fndecl (stack_save); | |
1774 | if (callee | |
1775 | && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL | |
1776 | && DECL_FUNCTION_CODE (callee) == BUILT_IN_STACK_SAVE) | |
1777 | { | |
1778 | gimple_stmt_iterator stack_save_gsi; | |
1779 | tree rhs; | |
bdd0e199 | 1780 | |
6ea999da | 1781 | stack_save_gsi = gsi_for_stmt (stack_save); |
1782 | rhs = build_int_cst (TREE_TYPE (gimple_call_arg (call, 0)), 0); | |
1783 | update_call_from_tree (&stack_save_gsi, rhs); | |
1784 | } | |
1785 | } | |
1786 | } | |
bdd0e199 | 1787 | |
75a70cf9 | 1788 | /* No effect, so the statement will be deleted. */ |
bdd0e199 | 1789 | return integer_zero_node; |
1790 | } | |
75a70cf9 | 1791 | |
8a58ed0a | 1792 | /* If va_list type is a simple pointer and nothing special is needed, |
1793 | optimize __builtin_va_start (&ap, 0) into ap = __builtin_next_arg (0), | |
1794 | __builtin_va_end (&ap) out as NOP and __builtin_va_copy into a simple | |
1795 | pointer assignment. */ | |
1796 | ||
1797 | static tree | |
75a70cf9 | 1798 | optimize_stdarg_builtin (gimple call) |
8a58ed0a | 1799 | { |
5f57a8b1 | 1800 | tree callee, lhs, rhs, cfun_va_list; |
8a58ed0a | 1801 | bool va_list_simple_ptr; |
389dd41b | 1802 | location_t loc = gimple_location (call); |
8a58ed0a | 1803 | |
75a70cf9 | 1804 | if (gimple_code (call) != GIMPLE_CALL) |
8a58ed0a | 1805 | return NULL_TREE; |
1806 | ||
75a70cf9 | 1807 | callee = gimple_call_fndecl (call); |
5f57a8b1 | 1808 | |
1809 | cfun_va_list = targetm.fn_abi_va_list (callee); | |
1810 | va_list_simple_ptr = POINTER_TYPE_P (cfun_va_list) | |
1811 | && (TREE_TYPE (cfun_va_list) == void_type_node | |
1812 | || TREE_TYPE (cfun_va_list) == char_type_node); | |
1813 | ||
8a58ed0a | 1814 | switch (DECL_FUNCTION_CODE (callee)) |
1815 | { | |
1816 | case BUILT_IN_VA_START: | |
1817 | if (!va_list_simple_ptr | |
1818 | || targetm.expand_builtin_va_start != NULL | |
75a70cf9 | 1819 | || built_in_decls[BUILT_IN_NEXT_ARG] == NULL) |
8a58ed0a | 1820 | return NULL_TREE; |
1821 | ||
75a70cf9 | 1822 | if (gimple_call_num_args (call) != 2) |
8a58ed0a | 1823 | return NULL_TREE; |
1824 | ||
75a70cf9 | 1825 | lhs = gimple_call_arg (call, 0); |
8a58ed0a | 1826 | if (!POINTER_TYPE_P (TREE_TYPE (lhs)) |
1827 | || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs))) | |
5f57a8b1 | 1828 | != TYPE_MAIN_VARIANT (cfun_va_list)) |
8a58ed0a | 1829 | return NULL_TREE; |
48e1416a | 1830 | |
389dd41b | 1831 | lhs = build_fold_indirect_ref_loc (loc, lhs); |
1832 | rhs = build_call_expr_loc (loc, built_in_decls[BUILT_IN_NEXT_ARG], | |
75a70cf9 | 1833 | 1, integer_zero_node); |
389dd41b | 1834 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); |
8a58ed0a | 1835 | return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs); |
1836 | ||
1837 | case BUILT_IN_VA_COPY: | |
1838 | if (!va_list_simple_ptr) | |
1839 | return NULL_TREE; | |
1840 | ||
75a70cf9 | 1841 | if (gimple_call_num_args (call) != 2) |
8a58ed0a | 1842 | return NULL_TREE; |
1843 | ||
75a70cf9 | 1844 | lhs = gimple_call_arg (call, 0); |
8a58ed0a | 1845 | if (!POINTER_TYPE_P (TREE_TYPE (lhs)) |
1846 | || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs))) | |
5f57a8b1 | 1847 | != TYPE_MAIN_VARIANT (cfun_va_list)) |
8a58ed0a | 1848 | return NULL_TREE; |
1849 | ||
389dd41b | 1850 | lhs = build_fold_indirect_ref_loc (loc, lhs); |
75a70cf9 | 1851 | rhs = gimple_call_arg (call, 1); |
8a58ed0a | 1852 | if (TYPE_MAIN_VARIANT (TREE_TYPE (rhs)) |
5f57a8b1 | 1853 | != TYPE_MAIN_VARIANT (cfun_va_list)) |
8a58ed0a | 1854 | return NULL_TREE; |
1855 | ||
389dd41b | 1856 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); |
8a58ed0a | 1857 | return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs); |
1858 | ||
1859 | case BUILT_IN_VA_END: | |
75a70cf9 | 1860 | /* No effect, so the statement will be deleted. */ |
8a58ed0a | 1861 | return integer_zero_node; |
1862 | ||
1863 | default: | |
1864 | gcc_unreachable (); | |
1865 | } | |
1866 | } | |
75a70cf9 | 1867 | |
4ee9c684 | 1868 | /* A simple pass that attempts to fold all builtin functions. This pass |
1869 | is run after we've propagated as many constants as we can. */ | |
1870 | ||
2a1990e9 | 1871 | static unsigned int |
4ee9c684 | 1872 | execute_fold_all_builtins (void) |
1873 | { | |
b36237eb | 1874 | bool cfg_changed = false; |
4ee9c684 | 1875 | basic_block bb; |
b1b7c0c4 | 1876 | unsigned int todoflags = 0; |
48e1416a | 1877 | |
4ee9c684 | 1878 | FOR_EACH_BB (bb) |
1879 | { | |
75a70cf9 | 1880 | gimple_stmt_iterator i; |
1881 | for (i = gsi_start_bb (bb); !gsi_end_p (i); ) | |
4ee9c684 | 1882 | { |
75a70cf9 | 1883 | gimple stmt, old_stmt; |
4ee9c684 | 1884 | tree callee, result; |
0a39fd54 | 1885 | enum built_in_function fcode; |
4ee9c684 | 1886 | |
75a70cf9 | 1887 | stmt = gsi_stmt (i); |
1888 | ||
1889 | if (gimple_code (stmt) != GIMPLE_CALL) | |
0a39fd54 | 1890 | { |
75a70cf9 | 1891 | gsi_next (&i); |
0a39fd54 | 1892 | continue; |
1893 | } | |
75a70cf9 | 1894 | callee = gimple_call_fndecl (stmt); |
4ee9c684 | 1895 | if (!callee || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL) |
0a39fd54 | 1896 | { |
75a70cf9 | 1897 | gsi_next (&i); |
0a39fd54 | 1898 | continue; |
1899 | } | |
1900 | fcode = DECL_FUNCTION_CODE (callee); | |
4ee9c684 | 1901 | |
2d18b16d | 1902 | result = gimple_fold_builtin (stmt); |
5a4b7e1e | 1903 | |
1904 | if (result) | |
75a70cf9 | 1905 | gimple_remove_stmt_histograms (cfun, stmt); |
5a4b7e1e | 1906 | |
4ee9c684 | 1907 | if (!result) |
1908 | switch (DECL_FUNCTION_CODE (callee)) | |
1909 | { | |
1910 | case BUILT_IN_CONSTANT_P: | |
1911 | /* Resolve __builtin_constant_p. If it hasn't been | |
1912 | folded to integer_one_node by now, it's fairly | |
1913 | certain that the value simply isn't constant. */ | |
75a70cf9 | 1914 | result = integer_zero_node; |
4ee9c684 | 1915 | break; |
1916 | ||
bdd0e199 | 1917 | case BUILT_IN_STACK_RESTORE: |
75a70cf9 | 1918 | result = optimize_stack_restore (i); |
8a58ed0a | 1919 | if (result) |
1920 | break; | |
75a70cf9 | 1921 | gsi_next (&i); |
8a58ed0a | 1922 | continue; |
1923 | ||
1924 | case BUILT_IN_VA_START: | |
1925 | case BUILT_IN_VA_END: | |
1926 | case BUILT_IN_VA_COPY: | |
1927 | /* These shouldn't be folded before pass_stdarg. */ | |
75a70cf9 | 1928 | result = optimize_stdarg_builtin (stmt); |
bdd0e199 | 1929 | if (result) |
1930 | break; | |
1931 | /* FALLTHRU */ | |
1932 | ||
4ee9c684 | 1933 | default: |
75a70cf9 | 1934 | gsi_next (&i); |
4ee9c684 | 1935 | continue; |
1936 | } | |
1937 | ||
1938 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1939 | { | |
1940 | fprintf (dump_file, "Simplified\n "); | |
75a70cf9 | 1941 | print_gimple_stmt (dump_file, stmt, 0, dump_flags); |
4ee9c684 | 1942 | } |
1943 | ||
75a70cf9 | 1944 | old_stmt = stmt; |
75a70cf9 | 1945 | if (!update_call_from_tree (&i, result)) |
0fefde02 | 1946 | { |
1947 | gimplify_and_update_call_from_tree (&i, result); | |
1948 | todoflags |= TODO_update_address_taken; | |
1949 | } | |
de6ed584 | 1950 | |
75a70cf9 | 1951 | stmt = gsi_stmt (i); |
4c5fd53c | 1952 | update_stmt (stmt); |
de6ed584 | 1953 | |
75a70cf9 | 1954 | if (maybe_clean_or_replace_eh_stmt (old_stmt, stmt) |
1955 | && gimple_purge_dead_eh_edges (bb)) | |
b36237eb | 1956 | cfg_changed = true; |
4ee9c684 | 1957 | |
1958 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1959 | { | |
1960 | fprintf (dump_file, "to\n "); | |
75a70cf9 | 1961 | print_gimple_stmt (dump_file, stmt, 0, dump_flags); |
4ee9c684 | 1962 | fprintf (dump_file, "\n"); |
1963 | } | |
0a39fd54 | 1964 | |
1965 | /* Retry the same statement if it changed into another | |
1966 | builtin, there might be new opportunities now. */ | |
75a70cf9 | 1967 | if (gimple_code (stmt) != GIMPLE_CALL) |
0a39fd54 | 1968 | { |
75a70cf9 | 1969 | gsi_next (&i); |
0a39fd54 | 1970 | continue; |
1971 | } | |
75a70cf9 | 1972 | callee = gimple_call_fndecl (stmt); |
0a39fd54 | 1973 | if (!callee |
75a70cf9 | 1974 | || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL |
0a39fd54 | 1975 | || DECL_FUNCTION_CODE (callee) == fcode) |
75a70cf9 | 1976 | gsi_next (&i); |
4ee9c684 | 1977 | } |
1978 | } | |
48e1416a | 1979 | |
b36237eb | 1980 | /* Delete unreachable blocks. */ |
b1b7c0c4 | 1981 | if (cfg_changed) |
1982 | todoflags |= TODO_cleanup_cfg; | |
48e1416a | 1983 | |
b1b7c0c4 | 1984 | return todoflags; |
4ee9c684 | 1985 | } |
1986 | ||
41511585 | 1987 | |
48e1416a | 1988 | struct gimple_opt_pass pass_fold_builtins = |
4ee9c684 | 1989 | { |
20099e35 | 1990 | { |
1991 | GIMPLE_PASS, | |
4ee9c684 | 1992 | "fab", /* name */ |
1993 | NULL, /* gate */ | |
1994 | execute_fold_all_builtins, /* execute */ | |
1995 | NULL, /* sub */ | |
1996 | NULL, /* next */ | |
1997 | 0, /* static_pass_number */ | |
0b1615c1 | 1998 | TV_NONE, /* tv_id */ |
49290934 | 1999 | PROP_cfg | PROP_ssa, /* properties_required */ |
4ee9c684 | 2000 | 0, /* properties_provided */ |
2001 | 0, /* properties_destroyed */ | |
2002 | 0, /* todo_flags_start */ | |
909e5ecb | 2003 | TODO_dump_func |
2004 | | TODO_verify_ssa | |
20099e35 | 2005 | | TODO_update_ssa /* todo_flags_finish */ |
2006 | } | |
4ee9c684 | 2007 | }; |