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4ee9c684 | 1 | /* Conditional constant propagation pass for the GNU compiler. |
711789cc | 2 | Copyright (C) 2000-2013 Free Software Foundation, Inc. |
4ee9c684 | 3 | Adapted from original RTL SSA-CCP by Daniel Berlin <dberlin@dberlin.org> |
4 | Adapted to GIMPLE trees by Diego Novillo <dnovillo@redhat.com> | |
5 | ||
6 | This file is part of GCC. | |
48e1416a | 7 | |
4ee9c684 | 8 | GCC is free software; you can redistribute it and/or modify it |
9 | under the terms of the GNU General Public License as published by the | |
8c4c00c1 | 10 | Free Software Foundation; either version 3, or (at your option) any |
4ee9c684 | 11 | later version. |
48e1416a | 12 | |
4ee9c684 | 13 | GCC is distributed in the hope that it will be useful, but WITHOUT |
14 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
16 | for more details. | |
48e1416a | 17 | |
4ee9c684 | 18 | You should have received a copy of the GNU General Public License |
8c4c00c1 | 19 | along with GCC; see the file COPYING3. If not see |
20 | <http://www.gnu.org/licenses/>. */ | |
4ee9c684 | 21 | |
88dbf20f | 22 | /* Conditional constant propagation (CCP) is based on the SSA |
23 | propagation engine (tree-ssa-propagate.c). Constant assignments of | |
24 | the form VAR = CST are propagated from the assignments into uses of | |
25 | VAR, which in turn may generate new constants. The simulation uses | |
26 | a four level lattice to keep track of constant values associated | |
27 | with SSA names. Given an SSA name V_i, it may take one of the | |
28 | following values: | |
29 | ||
bfa30570 | 30 | UNINITIALIZED -> the initial state of the value. This value |
31 | is replaced with a correct initial value | |
32 | the first time the value is used, so the | |
33 | rest of the pass does not need to care about | |
34 | it. Using this value simplifies initialization | |
35 | of the pass, and prevents us from needlessly | |
36 | scanning statements that are never reached. | |
88dbf20f | 37 | |
38 | UNDEFINED -> V_i is a local variable whose definition | |
39 | has not been processed yet. Therefore we | |
40 | don't yet know if its value is a constant | |
41 | or not. | |
42 | ||
43 | CONSTANT -> V_i has been found to hold a constant | |
44 | value C. | |
45 | ||
46 | VARYING -> V_i cannot take a constant value, or if it | |
47 | does, it is not possible to determine it | |
48 | at compile time. | |
49 | ||
50 | The core of SSA-CCP is in ccp_visit_stmt and ccp_visit_phi_node: | |
51 | ||
52 | 1- In ccp_visit_stmt, we are interested in assignments whose RHS | |
53 | evaluates into a constant and conditional jumps whose predicate | |
54 | evaluates into a boolean true or false. When an assignment of | |
55 | the form V_i = CONST is found, V_i's lattice value is set to | |
56 | CONSTANT and CONST is associated with it. This causes the | |
57 | propagation engine to add all the SSA edges coming out the | |
58 | assignment into the worklists, so that statements that use V_i | |
59 | can be visited. | |
60 | ||
61 | If the statement is a conditional with a constant predicate, we | |
62 | mark the outgoing edges as executable or not executable | |
63 | depending on the predicate's value. This is then used when | |
64 | visiting PHI nodes to know when a PHI argument can be ignored. | |
48e1416a | 65 | |
88dbf20f | 66 | |
67 | 2- In ccp_visit_phi_node, if all the PHI arguments evaluate to the | |
68 | same constant C, then the LHS of the PHI is set to C. This | |
69 | evaluation is known as the "meet operation". Since one of the | |
70 | goals of this evaluation is to optimistically return constant | |
71 | values as often as possible, it uses two main short cuts: | |
72 | ||
73 | - If an argument is flowing in through a non-executable edge, it | |
74 | is ignored. This is useful in cases like this: | |
75 | ||
76 | if (PRED) | |
77 | a_9 = 3; | |
78 | else | |
79 | a_10 = 100; | |
80 | a_11 = PHI (a_9, a_10) | |
81 | ||
82 | If PRED is known to always evaluate to false, then we can | |
83 | assume that a_11 will always take its value from a_10, meaning | |
84 | that instead of consider it VARYING (a_9 and a_10 have | |
85 | different values), we can consider it CONSTANT 100. | |
86 | ||
87 | - If an argument has an UNDEFINED value, then it does not affect | |
88 | the outcome of the meet operation. If a variable V_i has an | |
89 | UNDEFINED value, it means that either its defining statement | |
90 | hasn't been visited yet or V_i has no defining statement, in | |
91 | which case the original symbol 'V' is being used | |
92 | uninitialized. Since 'V' is a local variable, the compiler | |
93 | may assume any initial value for it. | |
94 | ||
95 | ||
96 | After propagation, every variable V_i that ends up with a lattice | |
97 | value of CONSTANT will have the associated constant value in the | |
98 | array CONST_VAL[i].VALUE. That is fed into substitute_and_fold for | |
99 | final substitution and folding. | |
100 | ||
4ee9c684 | 101 | References: |
102 | ||
103 | Constant propagation with conditional branches, | |
104 | Wegman and Zadeck, ACM TOPLAS 13(2):181-210. | |
105 | ||
106 | Building an Optimizing Compiler, | |
107 | Robert Morgan, Butterworth-Heinemann, 1998, Section 8.9. | |
108 | ||
109 | Advanced Compiler Design and Implementation, | |
110 | Steven Muchnick, Morgan Kaufmann, 1997, Section 12.6 */ | |
111 | ||
112 | #include "config.h" | |
113 | #include "system.h" | |
114 | #include "coretypes.h" | |
115 | #include "tm.h" | |
4ee9c684 | 116 | #include "tree.h" |
41511585 | 117 | #include "flags.h" |
4ee9c684 | 118 | #include "tm_p.h" |
4ee9c684 | 119 | #include "basic-block.h" |
41511585 | 120 | #include "function.h" |
ce084dfc | 121 | #include "gimple-pretty-print.h" |
41511585 | 122 | #include "tree-flow.h" |
4ee9c684 | 123 | #include "tree-pass.h" |
41511585 | 124 | #include "tree-ssa-propagate.h" |
5a4b7e1e | 125 | #include "value-prof.h" |
41511585 | 126 | #include "langhooks.h" |
8782adcf | 127 | #include "target.h" |
0b205f4c | 128 | #include "diagnostic-core.h" |
43fb76c1 | 129 | #include "dbgcnt.h" |
1d0b727d | 130 | #include "gimple-fold.h" |
9a65cc0a | 131 | #include "params.h" |
2b15d2ba | 132 | #include "hash-table.h" |
4ee9c684 | 133 | |
134 | ||
135 | /* Possible lattice values. */ | |
136 | typedef enum | |
137 | { | |
bfa30570 | 138 | UNINITIALIZED, |
4ee9c684 | 139 | UNDEFINED, |
140 | CONSTANT, | |
141 | VARYING | |
88dbf20f | 142 | } ccp_lattice_t; |
4ee9c684 | 143 | |
14f101cf | 144 | struct prop_value_d { |
145 | /* Lattice value. */ | |
146 | ccp_lattice_t lattice_val; | |
147 | ||
148 | /* Propagated value. */ | |
149 | tree value; | |
b7e55469 | 150 | |
151 | /* Mask that applies to the propagated value during CCP. For | |
152 | X with a CONSTANT lattice value X & ~mask == value & ~mask. */ | |
153 | double_int mask; | |
14f101cf | 154 | }; |
155 | ||
156 | typedef struct prop_value_d prop_value_t; | |
157 | ||
88dbf20f | 158 | /* Array of propagated constant values. After propagation, |
159 | CONST_VAL[I].VALUE holds the constant value for SSA_NAME(I). If | |
160 | the constant is held in an SSA name representing a memory store | |
4fb5e5ca | 161 | (i.e., a VDEF), CONST_VAL[I].MEM_REF will contain the actual |
162 | memory reference used to store (i.e., the LHS of the assignment | |
163 | doing the store). */ | |
20140406 | 164 | static prop_value_t *const_val; |
285df01b | 165 | static unsigned n_const_val; |
4ee9c684 | 166 | |
4af351a8 | 167 | static void canonicalize_float_value (prop_value_t *); |
6688f8ec | 168 | static bool ccp_fold_stmt (gimple_stmt_iterator *); |
4af351a8 | 169 | |
88dbf20f | 170 | /* Dump constant propagation value VAL to file OUTF prefixed by PREFIX. */ |
01406fc0 | 171 | |
172 | static void | |
88dbf20f | 173 | dump_lattice_value (FILE *outf, const char *prefix, prop_value_t val) |
01406fc0 | 174 | { |
41511585 | 175 | switch (val.lattice_val) |
01406fc0 | 176 | { |
88dbf20f | 177 | case UNINITIALIZED: |
178 | fprintf (outf, "%sUNINITIALIZED", prefix); | |
179 | break; | |
41511585 | 180 | case UNDEFINED: |
181 | fprintf (outf, "%sUNDEFINED", prefix); | |
182 | break; | |
183 | case VARYING: | |
184 | fprintf (outf, "%sVARYING", prefix); | |
185 | break; | |
41511585 | 186 | case CONSTANT: |
b7e55469 | 187 | if (TREE_CODE (val.value) != INTEGER_CST |
cf8f0e63 | 188 | || val.mask.is_zero ()) |
16ab4e97 | 189 | { |
190 | fprintf (outf, "%sCONSTANT ", prefix); | |
191 | print_generic_expr (outf, val.value, dump_flags); | |
192 | } | |
b7e55469 | 193 | else |
194 | { | |
cf8f0e63 | 195 | double_int cval = tree_to_double_int (val.value).and_not (val.mask); |
b7e55469 | 196 | fprintf (outf, "%sCONSTANT " HOST_WIDE_INT_PRINT_DOUBLE_HEX, |
197 | prefix, cval.high, cval.low); | |
198 | fprintf (outf, " (" HOST_WIDE_INT_PRINT_DOUBLE_HEX ")", | |
199 | val.mask.high, val.mask.low); | |
200 | } | |
41511585 | 201 | break; |
202 | default: | |
8c0963c4 | 203 | gcc_unreachable (); |
41511585 | 204 | } |
01406fc0 | 205 | } |
4ee9c684 | 206 | |
4ee9c684 | 207 | |
88dbf20f | 208 | /* Print lattice value VAL to stderr. */ |
209 | ||
210 | void debug_lattice_value (prop_value_t val); | |
211 | ||
4b987fac | 212 | DEBUG_FUNCTION void |
88dbf20f | 213 | debug_lattice_value (prop_value_t val) |
214 | { | |
215 | dump_lattice_value (stderr, "", val); | |
216 | fprintf (stderr, "\n"); | |
217 | } | |
4ee9c684 | 218 | |
4ee9c684 | 219 | |
88dbf20f | 220 | /* Compute a default value for variable VAR and store it in the |
221 | CONST_VAL array. The following rules are used to get default | |
222 | values: | |
01406fc0 | 223 | |
88dbf20f | 224 | 1- Global and static variables that are declared constant are |
225 | considered CONSTANT. | |
226 | ||
227 | 2- Any other value is considered UNDEFINED. This is useful when | |
41511585 | 228 | considering PHI nodes. PHI arguments that are undefined do not |
229 | change the constant value of the PHI node, which allows for more | |
88dbf20f | 230 | constants to be propagated. |
4ee9c684 | 231 | |
8883e700 | 232 | 3- Variables defined by statements other than assignments and PHI |
88dbf20f | 233 | nodes are considered VARYING. |
4ee9c684 | 234 | |
8883e700 | 235 | 4- Initial values of variables that are not GIMPLE registers are |
bfa30570 | 236 | considered VARYING. */ |
4ee9c684 | 237 | |
88dbf20f | 238 | static prop_value_t |
239 | get_default_value (tree var) | |
240 | { | |
b7e55469 | 241 | prop_value_t val = { UNINITIALIZED, NULL_TREE, { 0, 0 } }; |
8edeb88b | 242 | gimple stmt; |
243 | ||
244 | stmt = SSA_NAME_DEF_STMT (var); | |
245 | ||
246 | if (gimple_nop_p (stmt)) | |
4ee9c684 | 247 | { |
8edeb88b | 248 | /* Variables defined by an empty statement are those used |
249 | before being initialized. If VAR is a local variable, we | |
250 | can assume initially that it is UNDEFINED, otherwise we must | |
251 | consider it VARYING. */ | |
7c782c9b | 252 | if (!virtual_operand_p (var) |
253 | && TREE_CODE (SSA_NAME_VAR (var)) == VAR_DECL) | |
8edeb88b | 254 | val.lattice_val = UNDEFINED; |
255 | else | |
b7e55469 | 256 | { |
257 | val.lattice_val = VARYING; | |
258 | val.mask = double_int_minus_one; | |
259 | } | |
4ee9c684 | 260 | } |
8edeb88b | 261 | else if (is_gimple_assign (stmt) |
262 | /* Value-returning GIMPLE_CALL statements assign to | |
263 | a variable, and are treated similarly to GIMPLE_ASSIGN. */ | |
264 | || (is_gimple_call (stmt) | |
265 | && gimple_call_lhs (stmt) != NULL_TREE) | |
266 | || gimple_code (stmt) == GIMPLE_PHI) | |
41511585 | 267 | { |
8edeb88b | 268 | tree cst; |
269 | if (gimple_assign_single_p (stmt) | |
270 | && DECL_P (gimple_assign_rhs1 (stmt)) | |
271 | && (cst = get_symbol_constant_value (gimple_assign_rhs1 (stmt)))) | |
88dbf20f | 272 | { |
8edeb88b | 273 | val.lattice_val = CONSTANT; |
274 | val.value = cst; | |
88dbf20f | 275 | } |
276 | else | |
8edeb88b | 277 | /* Any other variable defined by an assignment or a PHI node |
278 | is considered UNDEFINED. */ | |
279 | val.lattice_val = UNDEFINED; | |
280 | } | |
281 | else | |
282 | { | |
283 | /* Otherwise, VAR will never take on a constant value. */ | |
284 | val.lattice_val = VARYING; | |
b7e55469 | 285 | val.mask = double_int_minus_one; |
41511585 | 286 | } |
4ee9c684 | 287 | |
41511585 | 288 | return val; |
289 | } | |
4ee9c684 | 290 | |
4ee9c684 | 291 | |
bfa30570 | 292 | /* Get the constant value associated with variable VAR. */ |
4ee9c684 | 293 | |
bfa30570 | 294 | static inline prop_value_t * |
295 | get_value (tree var) | |
88dbf20f | 296 | { |
e004838d | 297 | prop_value_t *val; |
bfa30570 | 298 | |
285df01b | 299 | if (const_val == NULL |
300 | || SSA_NAME_VERSION (var) >= n_const_val) | |
e004838d | 301 | return NULL; |
302 | ||
303 | val = &const_val[SSA_NAME_VERSION (var)]; | |
bfa30570 | 304 | if (val->lattice_val == UNINITIALIZED) |
4ee9c684 | 305 | *val = get_default_value (var); |
306 | ||
4af351a8 | 307 | canonicalize_float_value (val); |
308 | ||
4ee9c684 | 309 | return val; |
310 | } | |
311 | ||
15d138c9 | 312 | /* Return the constant tree value associated with VAR. */ |
313 | ||
314 | static inline tree | |
315 | get_constant_value (tree var) | |
316 | { | |
98d92e3c | 317 | prop_value_t *val; |
318 | if (TREE_CODE (var) != SSA_NAME) | |
319 | { | |
320 | if (is_gimple_min_invariant (var)) | |
321 | return var; | |
322 | return NULL_TREE; | |
323 | } | |
324 | val = get_value (var); | |
b7e55469 | 325 | if (val |
326 | && val->lattice_val == CONSTANT | |
327 | && (TREE_CODE (val->value) != INTEGER_CST | |
cf8f0e63 | 328 | || val->mask.is_zero ())) |
15d138c9 | 329 | return val->value; |
330 | return NULL_TREE; | |
331 | } | |
332 | ||
bfa30570 | 333 | /* Sets the value associated with VAR to VARYING. */ |
334 | ||
335 | static inline void | |
336 | set_value_varying (tree var) | |
337 | { | |
338 | prop_value_t *val = &const_val[SSA_NAME_VERSION (var)]; | |
339 | ||
340 | val->lattice_val = VARYING; | |
341 | val->value = NULL_TREE; | |
b7e55469 | 342 | val->mask = double_int_minus_one; |
bfa30570 | 343 | } |
4ee9c684 | 344 | |
b31eb493 | 345 | /* For float types, modify the value of VAL to make ccp work correctly |
346 | for non-standard values (-0, NaN): | |
347 | ||
348 | If HONOR_SIGNED_ZEROS is false, and VAL = -0, we canonicalize it to 0. | |
349 | If HONOR_NANS is false, and VAL is NaN, we canonicalize it to UNDEFINED. | |
350 | This is to fix the following problem (see PR 29921): Suppose we have | |
351 | ||
352 | x = 0.0 * y | |
353 | ||
354 | and we set value of y to NaN. This causes value of x to be set to NaN. | |
355 | When we later determine that y is in fact VARYING, fold uses the fact | |
356 | that HONOR_NANS is false, and we try to change the value of x to 0, | |
357 | causing an ICE. With HONOR_NANS being false, the real appearance of | |
358 | NaN would cause undefined behavior, though, so claiming that y (and x) | |
359 | are UNDEFINED initially is correct. */ | |
360 | ||
361 | static void | |
362 | canonicalize_float_value (prop_value_t *val) | |
363 | { | |
364 | enum machine_mode mode; | |
365 | tree type; | |
366 | REAL_VALUE_TYPE d; | |
367 | ||
368 | if (val->lattice_val != CONSTANT | |
369 | || TREE_CODE (val->value) != REAL_CST) | |
370 | return; | |
371 | ||
372 | d = TREE_REAL_CST (val->value); | |
373 | type = TREE_TYPE (val->value); | |
374 | mode = TYPE_MODE (type); | |
375 | ||
376 | if (!HONOR_SIGNED_ZEROS (mode) | |
377 | && REAL_VALUE_MINUS_ZERO (d)) | |
378 | { | |
379 | val->value = build_real (type, dconst0); | |
380 | return; | |
381 | } | |
382 | ||
383 | if (!HONOR_NANS (mode) | |
384 | && REAL_VALUE_ISNAN (d)) | |
385 | { | |
386 | val->lattice_val = UNDEFINED; | |
387 | val->value = NULL; | |
b31eb493 | 388 | return; |
389 | } | |
390 | } | |
391 | ||
b7e55469 | 392 | /* Return whether the lattice transition is valid. */ |
393 | ||
394 | static bool | |
395 | valid_lattice_transition (prop_value_t old_val, prop_value_t new_val) | |
396 | { | |
397 | /* Lattice transitions must always be monotonically increasing in | |
398 | value. */ | |
399 | if (old_val.lattice_val < new_val.lattice_val) | |
400 | return true; | |
401 | ||
402 | if (old_val.lattice_val != new_val.lattice_val) | |
403 | return false; | |
404 | ||
405 | if (!old_val.value && !new_val.value) | |
406 | return true; | |
407 | ||
408 | /* Now both lattice values are CONSTANT. */ | |
409 | ||
43c92e0a | 410 | /* Allow transitioning from PHI <&x, not executable> == &x |
411 | to PHI <&x, &y> == common alignment. */ | |
b7e55469 | 412 | if (TREE_CODE (old_val.value) != INTEGER_CST |
413 | && TREE_CODE (new_val.value) == INTEGER_CST) | |
414 | return true; | |
415 | ||
416 | /* Bit-lattices have to agree in the still valid bits. */ | |
417 | if (TREE_CODE (old_val.value) == INTEGER_CST | |
418 | && TREE_CODE (new_val.value) == INTEGER_CST) | |
cf8f0e63 | 419 | return tree_to_double_int (old_val.value).and_not (new_val.mask) |
420 | == tree_to_double_int (new_val.value).and_not (new_val.mask); | |
b7e55469 | 421 | |
422 | /* Otherwise constant values have to agree. */ | |
423 | return operand_equal_p (old_val.value, new_val.value, 0); | |
424 | } | |
425 | ||
88dbf20f | 426 | /* Set the value for variable VAR to NEW_VAL. Return true if the new |
427 | value is different from VAR's previous value. */ | |
4ee9c684 | 428 | |
41511585 | 429 | static bool |
88dbf20f | 430 | set_lattice_value (tree var, prop_value_t new_val) |
4ee9c684 | 431 | { |
6d0bf6d6 | 432 | /* We can deal with old UNINITIALIZED values just fine here. */ |
433 | prop_value_t *old_val = &const_val[SSA_NAME_VERSION (var)]; | |
88dbf20f | 434 | |
b31eb493 | 435 | canonicalize_float_value (&new_val); |
436 | ||
b7e55469 | 437 | /* We have to be careful to not go up the bitwise lattice |
438 | represented by the mask. | |
439 | ??? This doesn't seem to be the best place to enforce this. */ | |
440 | if (new_val.lattice_val == CONSTANT | |
441 | && old_val->lattice_val == CONSTANT | |
442 | && TREE_CODE (new_val.value) == INTEGER_CST | |
443 | && TREE_CODE (old_val->value) == INTEGER_CST) | |
444 | { | |
445 | double_int diff; | |
cf8f0e63 | 446 | diff = tree_to_double_int (new_val.value) |
447 | ^ tree_to_double_int (old_val->value); | |
448 | new_val.mask = new_val.mask | old_val->mask | diff; | |
b7e55469 | 449 | } |
bfa30570 | 450 | |
b7e55469 | 451 | gcc_assert (valid_lattice_transition (*old_val, new_val)); |
88dbf20f | 452 | |
b7e55469 | 453 | /* If *OLD_VAL and NEW_VAL are the same, return false to inform the |
454 | caller that this was a non-transition. */ | |
455 | if (old_val->lattice_val != new_val.lattice_val | |
456 | || (new_val.lattice_val == CONSTANT | |
457 | && TREE_CODE (new_val.value) == INTEGER_CST | |
458 | && (TREE_CODE (old_val->value) != INTEGER_CST | |
cf8f0e63 | 459 | || new_val.mask != old_val->mask))) |
4ee9c684 | 460 | { |
b7e55469 | 461 | /* ??? We would like to delay creation of INTEGER_CSTs from |
462 | partially constants here. */ | |
463 | ||
41511585 | 464 | if (dump_file && (dump_flags & TDF_DETAILS)) |
465 | { | |
88dbf20f | 466 | dump_lattice_value (dump_file, "Lattice value changed to ", new_val); |
bfa30570 | 467 | fprintf (dump_file, ". Adding SSA edges to worklist.\n"); |
41511585 | 468 | } |
469 | ||
88dbf20f | 470 | *old_val = new_val; |
471 | ||
6d0bf6d6 | 472 | gcc_assert (new_val.lattice_val != UNINITIALIZED); |
bfa30570 | 473 | return true; |
4ee9c684 | 474 | } |
41511585 | 475 | |
476 | return false; | |
4ee9c684 | 477 | } |
478 | ||
b7e55469 | 479 | static prop_value_t get_value_for_expr (tree, bool); |
480 | static prop_value_t bit_value_binop (enum tree_code, tree, tree, tree); | |
481 | static void bit_value_binop_1 (enum tree_code, tree, double_int *, double_int *, | |
482 | tree, double_int, double_int, | |
483 | tree, double_int, double_int); | |
484 | ||
485 | /* Return a double_int that can be used for bitwise simplifications | |
486 | from VAL. */ | |
487 | ||
488 | static double_int | |
489 | value_to_double_int (prop_value_t val) | |
490 | { | |
491 | if (val.value | |
492 | && TREE_CODE (val.value) == INTEGER_CST) | |
493 | return tree_to_double_int (val.value); | |
494 | else | |
495 | return double_int_zero; | |
496 | } | |
497 | ||
498 | /* Return the value for the address expression EXPR based on alignment | |
499 | information. */ | |
6d0bf6d6 | 500 | |
501 | static prop_value_t | |
b7e55469 | 502 | get_value_from_alignment (tree expr) |
503 | { | |
f8abb542 | 504 | tree type = TREE_TYPE (expr); |
b7e55469 | 505 | prop_value_t val; |
f8abb542 | 506 | unsigned HOST_WIDE_INT bitpos; |
507 | unsigned int align; | |
b7e55469 | 508 | |
509 | gcc_assert (TREE_CODE (expr) == ADDR_EXPR); | |
510 | ||
59da1bcd | 511 | get_pointer_alignment_1 (expr, &align, &bitpos); |
cf8f0e63 | 512 | val.mask = (POINTER_TYPE_P (type) || TYPE_UNSIGNED (type) |
513 | ? double_int::mask (TYPE_PRECISION (type)) | |
514 | : double_int_minus_one) | |
515 | .and_not (double_int::from_uhwi (align / BITS_PER_UNIT - 1)); | |
516 | val.lattice_val = val.mask.is_minus_one () ? VARYING : CONSTANT; | |
f8abb542 | 517 | if (val.lattice_val == CONSTANT) |
518 | val.value | |
cf8f0e63 | 519 | = double_int_to_tree (type, |
520 | double_int::from_uhwi (bitpos / BITS_PER_UNIT)); | |
b7e55469 | 521 | else |
f8abb542 | 522 | val.value = NULL_TREE; |
b7e55469 | 523 | |
524 | return val; | |
525 | } | |
526 | ||
527 | /* Return the value for the tree operand EXPR. If FOR_BITS_P is true | |
528 | return constant bits extracted from alignment information for | |
529 | invariant addresses. */ | |
530 | ||
531 | static prop_value_t | |
532 | get_value_for_expr (tree expr, bool for_bits_p) | |
6d0bf6d6 | 533 | { |
534 | prop_value_t val; | |
535 | ||
536 | if (TREE_CODE (expr) == SSA_NAME) | |
b7e55469 | 537 | { |
538 | val = *get_value (expr); | |
539 | if (for_bits_p | |
540 | && val.lattice_val == CONSTANT | |
541 | && TREE_CODE (val.value) == ADDR_EXPR) | |
542 | val = get_value_from_alignment (val.value); | |
543 | } | |
544 | else if (is_gimple_min_invariant (expr) | |
545 | && (!for_bits_p || TREE_CODE (expr) != ADDR_EXPR)) | |
6d0bf6d6 | 546 | { |
547 | val.lattice_val = CONSTANT; | |
548 | val.value = expr; | |
b7e55469 | 549 | val.mask = double_int_zero; |
6d0bf6d6 | 550 | canonicalize_float_value (&val); |
551 | } | |
b7e55469 | 552 | else if (TREE_CODE (expr) == ADDR_EXPR) |
553 | val = get_value_from_alignment (expr); | |
6d0bf6d6 | 554 | else |
555 | { | |
556 | val.lattice_val = VARYING; | |
b7e55469 | 557 | val.mask = double_int_minus_one; |
6d0bf6d6 | 558 | val.value = NULL_TREE; |
559 | } | |
6d0bf6d6 | 560 | return val; |
561 | } | |
562 | ||
88dbf20f | 563 | /* Return the likely CCP lattice value for STMT. |
4ee9c684 | 564 | |
41511585 | 565 | If STMT has no operands, then return CONSTANT. |
4ee9c684 | 566 | |
d61b9af3 | 567 | Else if undefinedness of operands of STMT cause its value to be |
568 | undefined, then return UNDEFINED. | |
4ee9c684 | 569 | |
41511585 | 570 | Else if any operands of STMT are constants, then return CONSTANT. |
4ee9c684 | 571 | |
41511585 | 572 | Else return VARYING. */ |
4ee9c684 | 573 | |
88dbf20f | 574 | static ccp_lattice_t |
75a70cf9 | 575 | likely_value (gimple stmt) |
41511585 | 576 | { |
d61b9af3 | 577 | bool has_constant_operand, has_undefined_operand, all_undefined_operands; |
41511585 | 578 | tree use; |
579 | ssa_op_iter iter; | |
8edeb88b | 580 | unsigned i; |
4ee9c684 | 581 | |
590c3166 | 582 | enum gimple_code code = gimple_code (stmt); |
75a70cf9 | 583 | |
584 | /* This function appears to be called only for assignments, calls, | |
585 | conditionals, and switches, due to the logic in visit_stmt. */ | |
586 | gcc_assert (code == GIMPLE_ASSIGN | |
587 | || code == GIMPLE_CALL | |
588 | || code == GIMPLE_COND | |
589 | || code == GIMPLE_SWITCH); | |
88dbf20f | 590 | |
591 | /* If the statement has volatile operands, it won't fold to a | |
592 | constant value. */ | |
75a70cf9 | 593 | if (gimple_has_volatile_ops (stmt)) |
88dbf20f | 594 | return VARYING; |
595 | ||
75a70cf9 | 596 | /* Arrive here for more complex cases. */ |
bfa30570 | 597 | has_constant_operand = false; |
d61b9af3 | 598 | has_undefined_operand = false; |
599 | all_undefined_operands = true; | |
8edeb88b | 600 | FOR_EACH_SSA_TREE_OPERAND (use, stmt, iter, SSA_OP_USE) |
41511585 | 601 | { |
bfa30570 | 602 | prop_value_t *val = get_value (use); |
41511585 | 603 | |
bfa30570 | 604 | if (val->lattice_val == UNDEFINED) |
d61b9af3 | 605 | has_undefined_operand = true; |
606 | else | |
607 | all_undefined_operands = false; | |
88dbf20f | 608 | |
41511585 | 609 | if (val->lattice_val == CONSTANT) |
bfa30570 | 610 | has_constant_operand = true; |
4ee9c684 | 611 | } |
41511585 | 612 | |
dd277d48 | 613 | /* There may be constants in regular rhs operands. For calls we |
614 | have to ignore lhs, fndecl and static chain, otherwise only | |
615 | the lhs. */ | |
616 | for (i = (is_gimple_call (stmt) ? 2 : 0) + gimple_has_lhs (stmt); | |
8edeb88b | 617 | i < gimple_num_ops (stmt); ++i) |
618 | { | |
619 | tree op = gimple_op (stmt, i); | |
620 | if (!op || TREE_CODE (op) == SSA_NAME) | |
621 | continue; | |
622 | if (is_gimple_min_invariant (op)) | |
623 | has_constant_operand = true; | |
624 | } | |
625 | ||
87c0a9fc | 626 | if (has_constant_operand) |
627 | all_undefined_operands = false; | |
628 | ||
d61b9af3 | 629 | /* If the operation combines operands like COMPLEX_EXPR make sure to |
630 | not mark the result UNDEFINED if only one part of the result is | |
631 | undefined. */ | |
75a70cf9 | 632 | if (has_undefined_operand && all_undefined_operands) |
d61b9af3 | 633 | return UNDEFINED; |
75a70cf9 | 634 | else if (code == GIMPLE_ASSIGN && has_undefined_operand) |
d61b9af3 | 635 | { |
75a70cf9 | 636 | switch (gimple_assign_rhs_code (stmt)) |
d61b9af3 | 637 | { |
638 | /* Unary operators are handled with all_undefined_operands. */ | |
639 | case PLUS_EXPR: | |
640 | case MINUS_EXPR: | |
d61b9af3 | 641 | case POINTER_PLUS_EXPR: |
d61b9af3 | 642 | /* Not MIN_EXPR, MAX_EXPR. One VARYING operand may be selected. |
643 | Not bitwise operators, one VARYING operand may specify the | |
644 | result completely. Not logical operators for the same reason. | |
05a936a0 | 645 | Not COMPLEX_EXPR as one VARYING operand makes the result partly |
646 | not UNDEFINED. Not *DIV_EXPR, comparisons and shifts because | |
647 | the undefined operand may be promoted. */ | |
d61b9af3 | 648 | return UNDEFINED; |
649 | ||
43c92e0a | 650 | case ADDR_EXPR: |
651 | /* If any part of an address is UNDEFINED, like the index | |
652 | of an ARRAY_EXPR, then treat the result as UNDEFINED. */ | |
653 | return UNDEFINED; | |
654 | ||
d61b9af3 | 655 | default: |
656 | ; | |
657 | } | |
658 | } | |
659 | /* If there was an UNDEFINED operand but the result may be not UNDEFINED | |
c91fedc5 | 660 | fall back to CONSTANT. During iteration UNDEFINED may still drop |
661 | to CONSTANT. */ | |
d61b9af3 | 662 | if (has_undefined_operand) |
c91fedc5 | 663 | return CONSTANT; |
d61b9af3 | 664 | |
8edeb88b | 665 | /* We do not consider virtual operands here -- load from read-only |
666 | memory may have only VARYING virtual operands, but still be | |
667 | constant. */ | |
bfa30570 | 668 | if (has_constant_operand |
8edeb88b | 669 | || gimple_references_memory_p (stmt)) |
88dbf20f | 670 | return CONSTANT; |
671 | ||
bfa30570 | 672 | return VARYING; |
4ee9c684 | 673 | } |
674 | ||
bfa30570 | 675 | /* Returns true if STMT cannot be constant. */ |
676 | ||
677 | static bool | |
75a70cf9 | 678 | surely_varying_stmt_p (gimple stmt) |
bfa30570 | 679 | { |
680 | /* If the statement has operands that we cannot handle, it cannot be | |
681 | constant. */ | |
75a70cf9 | 682 | if (gimple_has_volatile_ops (stmt)) |
bfa30570 | 683 | return true; |
684 | ||
f257af64 | 685 | /* If it is a call and does not return a value or is not a |
686 | builtin and not an indirect call, it is varying. */ | |
75a70cf9 | 687 | if (is_gimple_call (stmt)) |
f257af64 | 688 | { |
689 | tree fndecl; | |
690 | if (!gimple_call_lhs (stmt) | |
691 | || ((fndecl = gimple_call_fndecl (stmt)) != NULL_TREE | |
5768aeb3 | 692 | && !DECL_BUILT_IN (fndecl))) |
f257af64 | 693 | return true; |
694 | } | |
bfa30570 | 695 | |
8edeb88b | 696 | /* Any other store operation is not interesting. */ |
dd277d48 | 697 | else if (gimple_vdef (stmt)) |
8edeb88b | 698 | return true; |
699 | ||
bfa30570 | 700 | /* Anything other than assignments and conditional jumps are not |
701 | interesting for CCP. */ | |
75a70cf9 | 702 | if (gimple_code (stmt) != GIMPLE_ASSIGN |
f257af64 | 703 | && gimple_code (stmt) != GIMPLE_COND |
704 | && gimple_code (stmt) != GIMPLE_SWITCH | |
705 | && gimple_code (stmt) != GIMPLE_CALL) | |
bfa30570 | 706 | return true; |
707 | ||
708 | return false; | |
709 | } | |
4ee9c684 | 710 | |
41511585 | 711 | /* Initialize local data structures for CCP. */ |
4ee9c684 | 712 | |
713 | static void | |
41511585 | 714 | ccp_initialize (void) |
4ee9c684 | 715 | { |
41511585 | 716 | basic_block bb; |
4ee9c684 | 717 | |
285df01b | 718 | n_const_val = num_ssa_names; |
719 | const_val = XCNEWVEC (prop_value_t, n_const_val); | |
4ee9c684 | 720 | |
41511585 | 721 | /* Initialize simulation flags for PHI nodes and statements. */ |
722 | FOR_EACH_BB (bb) | |
4ee9c684 | 723 | { |
75a70cf9 | 724 | gimple_stmt_iterator i; |
4ee9c684 | 725 | |
75a70cf9 | 726 | for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i)) |
41511585 | 727 | { |
75a70cf9 | 728 | gimple stmt = gsi_stmt (i); |
2193544e | 729 | bool is_varying; |
730 | ||
731 | /* If the statement is a control insn, then we do not | |
732 | want to avoid simulating the statement once. Failure | |
733 | to do so means that those edges will never get added. */ | |
734 | if (stmt_ends_bb_p (stmt)) | |
735 | is_varying = false; | |
736 | else | |
737 | is_varying = surely_varying_stmt_p (stmt); | |
4ee9c684 | 738 | |
bfa30570 | 739 | if (is_varying) |
41511585 | 740 | { |
88dbf20f | 741 | tree def; |
742 | ssa_op_iter iter; | |
743 | ||
744 | /* If the statement will not produce a constant, mark | |
745 | all its outputs VARYING. */ | |
746 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS) | |
8edeb88b | 747 | set_value_varying (def); |
41511585 | 748 | } |
75a70cf9 | 749 | prop_set_simulate_again (stmt, !is_varying); |
41511585 | 750 | } |
4ee9c684 | 751 | } |
752 | ||
75a70cf9 | 753 | /* Now process PHI nodes. We never clear the simulate_again flag on |
754 | phi nodes, since we do not know which edges are executable yet, | |
755 | except for phi nodes for virtual operands when we do not do store ccp. */ | |
41511585 | 756 | FOR_EACH_BB (bb) |
4ee9c684 | 757 | { |
75a70cf9 | 758 | gimple_stmt_iterator i; |
41511585 | 759 | |
75a70cf9 | 760 | for (i = gsi_start_phis (bb); !gsi_end_p (i); gsi_next (&i)) |
761 | { | |
762 | gimple phi = gsi_stmt (i); | |
763 | ||
7c782c9b | 764 | if (virtual_operand_p (gimple_phi_result (phi))) |
75a70cf9 | 765 | prop_set_simulate_again (phi, false); |
bfa30570 | 766 | else |
75a70cf9 | 767 | prop_set_simulate_again (phi, true); |
41511585 | 768 | } |
4ee9c684 | 769 | } |
41511585 | 770 | } |
4ee9c684 | 771 | |
43fb76c1 | 772 | /* Debug count support. Reset the values of ssa names |
773 | VARYING when the total number ssa names analyzed is | |
774 | beyond the debug count specified. */ | |
775 | ||
776 | static void | |
777 | do_dbg_cnt (void) | |
778 | { | |
779 | unsigned i; | |
780 | for (i = 0; i < num_ssa_names; i++) | |
781 | { | |
782 | if (!dbg_cnt (ccp)) | |
783 | { | |
784 | const_val[i].lattice_val = VARYING; | |
b7e55469 | 785 | const_val[i].mask = double_int_minus_one; |
43fb76c1 | 786 | const_val[i].value = NULL_TREE; |
787 | } | |
788 | } | |
789 | } | |
790 | ||
4ee9c684 | 791 | |
88dbf20f | 792 | /* Do final substitution of propagated values, cleanup the flowgraph and |
48e1416a | 793 | free allocated storage. |
4ee9c684 | 794 | |
33a34f1e | 795 | Return TRUE when something was optimized. */ |
796 | ||
797 | static bool | |
88dbf20f | 798 | ccp_finalize (void) |
4ee9c684 | 799 | { |
43fb76c1 | 800 | bool something_changed; |
153c3b50 | 801 | unsigned i; |
43fb76c1 | 802 | |
803 | do_dbg_cnt (); | |
153c3b50 | 804 | |
805 | /* Derive alignment and misalignment information from partially | |
806 | constant pointers in the lattice. */ | |
807 | for (i = 1; i < num_ssa_names; ++i) | |
808 | { | |
809 | tree name = ssa_name (i); | |
810 | prop_value_t *val; | |
153c3b50 | 811 | unsigned int tem, align; |
812 | ||
813 | if (!name | |
814 | || !POINTER_TYPE_P (TREE_TYPE (name))) | |
815 | continue; | |
816 | ||
817 | val = get_value (name); | |
818 | if (val->lattice_val != CONSTANT | |
819 | || TREE_CODE (val->value) != INTEGER_CST) | |
820 | continue; | |
821 | ||
822 | /* Trailing constant bits specify the alignment, trailing value | |
823 | bits the misalignment. */ | |
824 | tem = val->mask.low; | |
825 | align = (tem & -tem); | |
ceea063b | 826 | if (align > 1) |
827 | set_ptr_info_alignment (get_ptr_info (name), align, | |
828 | TREE_INT_CST_LOW (val->value) & (align - 1)); | |
153c3b50 | 829 | } |
830 | ||
88dbf20f | 831 | /* Perform substitutions based on the known constant values. */ |
14f101cf | 832 | something_changed = substitute_and_fold (get_constant_value, |
833 | ccp_fold_stmt, true); | |
4ee9c684 | 834 | |
88dbf20f | 835 | free (const_val); |
e004838d | 836 | const_val = NULL; |
33a34f1e | 837 | return something_changed;; |
4ee9c684 | 838 | } |
839 | ||
840 | ||
88dbf20f | 841 | /* Compute the meet operator between *VAL1 and *VAL2. Store the result |
842 | in VAL1. | |
843 | ||
844 | any M UNDEFINED = any | |
88dbf20f | 845 | any M VARYING = VARYING |
846 | Ci M Cj = Ci if (i == j) | |
847 | Ci M Cj = VARYING if (i != j) | |
bfa30570 | 848 | */ |
4ee9c684 | 849 | |
850 | static void | |
88dbf20f | 851 | ccp_lattice_meet (prop_value_t *val1, prop_value_t *val2) |
4ee9c684 | 852 | { |
88dbf20f | 853 | if (val1->lattice_val == UNDEFINED) |
4ee9c684 | 854 | { |
88dbf20f | 855 | /* UNDEFINED M any = any */ |
856 | *val1 = *val2; | |
41511585 | 857 | } |
88dbf20f | 858 | else if (val2->lattice_val == UNDEFINED) |
92481a4d | 859 | { |
88dbf20f | 860 | /* any M UNDEFINED = any |
861 | Nothing to do. VAL1 already contains the value we want. */ | |
862 | ; | |
92481a4d | 863 | } |
88dbf20f | 864 | else if (val1->lattice_val == VARYING |
865 | || val2->lattice_val == VARYING) | |
41511585 | 866 | { |
88dbf20f | 867 | /* any M VARYING = VARYING. */ |
868 | val1->lattice_val = VARYING; | |
b7e55469 | 869 | val1->mask = double_int_minus_one; |
88dbf20f | 870 | val1->value = NULL_TREE; |
41511585 | 871 | } |
b7e55469 | 872 | else if (val1->lattice_val == CONSTANT |
873 | && val2->lattice_val == CONSTANT | |
874 | && TREE_CODE (val1->value) == INTEGER_CST | |
875 | && TREE_CODE (val2->value) == INTEGER_CST) | |
876 | { | |
877 | /* Ci M Cj = Ci if (i == j) | |
878 | Ci M Cj = VARYING if (i != j) | |
879 | ||
880 | For INTEGER_CSTs mask unequal bits. If no equal bits remain, | |
881 | drop to varying. */ | |
cf8f0e63 | 882 | val1->mask = val1->mask | val2->mask |
883 | | (tree_to_double_int (val1->value) | |
884 | ^ tree_to_double_int (val2->value)); | |
885 | if (val1->mask.is_minus_one ()) | |
b7e55469 | 886 | { |
887 | val1->lattice_val = VARYING; | |
888 | val1->value = NULL_TREE; | |
889 | } | |
890 | } | |
88dbf20f | 891 | else if (val1->lattice_val == CONSTANT |
892 | && val2->lattice_val == CONSTANT | |
61207d43 | 893 | && simple_cst_equal (val1->value, val2->value) == 1) |
41511585 | 894 | { |
88dbf20f | 895 | /* Ci M Cj = Ci if (i == j) |
896 | Ci M Cj = VARYING if (i != j) | |
897 | ||
b7e55469 | 898 | VAL1 already contains the value we want for equivalent values. */ |
899 | } | |
900 | else if (val1->lattice_val == CONSTANT | |
901 | && val2->lattice_val == CONSTANT | |
902 | && (TREE_CODE (val1->value) == ADDR_EXPR | |
903 | || TREE_CODE (val2->value) == ADDR_EXPR)) | |
904 | { | |
905 | /* When not equal addresses are involved try meeting for | |
906 | alignment. */ | |
907 | prop_value_t tem = *val2; | |
908 | if (TREE_CODE (val1->value) == ADDR_EXPR) | |
909 | *val1 = get_value_for_expr (val1->value, true); | |
910 | if (TREE_CODE (val2->value) == ADDR_EXPR) | |
911 | tem = get_value_for_expr (val2->value, true); | |
912 | ccp_lattice_meet (val1, &tem); | |
41511585 | 913 | } |
914 | else | |
915 | { | |
88dbf20f | 916 | /* Any other combination is VARYING. */ |
917 | val1->lattice_val = VARYING; | |
b7e55469 | 918 | val1->mask = double_int_minus_one; |
88dbf20f | 919 | val1->value = NULL_TREE; |
41511585 | 920 | } |
4ee9c684 | 921 | } |
922 | ||
923 | ||
41511585 | 924 | /* Loop through the PHI_NODE's parameters for BLOCK and compare their |
925 | lattice values to determine PHI_NODE's lattice value. The value of a | |
88dbf20f | 926 | PHI node is determined calling ccp_lattice_meet with all the arguments |
41511585 | 927 | of the PHI node that are incoming via executable edges. */ |
4ee9c684 | 928 | |
41511585 | 929 | static enum ssa_prop_result |
75a70cf9 | 930 | ccp_visit_phi_node (gimple phi) |
4ee9c684 | 931 | { |
75a70cf9 | 932 | unsigned i; |
88dbf20f | 933 | prop_value_t *old_val, new_val; |
4ee9c684 | 934 | |
41511585 | 935 | if (dump_file && (dump_flags & TDF_DETAILS)) |
4ee9c684 | 936 | { |
41511585 | 937 | fprintf (dump_file, "\nVisiting PHI node: "); |
75a70cf9 | 938 | print_gimple_stmt (dump_file, phi, 0, dump_flags); |
4ee9c684 | 939 | } |
4ee9c684 | 940 | |
75a70cf9 | 941 | old_val = get_value (gimple_phi_result (phi)); |
41511585 | 942 | switch (old_val->lattice_val) |
943 | { | |
944 | case VARYING: | |
88dbf20f | 945 | return SSA_PROP_VARYING; |
4ee9c684 | 946 | |
41511585 | 947 | case CONSTANT: |
948 | new_val = *old_val; | |
949 | break; | |
4ee9c684 | 950 | |
41511585 | 951 | case UNDEFINED: |
41511585 | 952 | new_val.lattice_val = UNDEFINED; |
88dbf20f | 953 | new_val.value = NULL_TREE; |
41511585 | 954 | break; |
4ee9c684 | 955 | |
41511585 | 956 | default: |
8c0963c4 | 957 | gcc_unreachable (); |
41511585 | 958 | } |
4ee9c684 | 959 | |
75a70cf9 | 960 | for (i = 0; i < gimple_phi_num_args (phi); i++) |
41511585 | 961 | { |
88dbf20f | 962 | /* Compute the meet operator over all the PHI arguments flowing |
963 | through executable edges. */ | |
75a70cf9 | 964 | edge e = gimple_phi_arg_edge (phi, i); |
4ee9c684 | 965 | |
41511585 | 966 | if (dump_file && (dump_flags & TDF_DETAILS)) |
967 | { | |
968 | fprintf (dump_file, | |
969 | "\n Argument #%d (%d -> %d %sexecutable)\n", | |
970 | i, e->src->index, e->dest->index, | |
971 | (e->flags & EDGE_EXECUTABLE) ? "" : "not "); | |
972 | } | |
973 | ||
974 | /* If the incoming edge is executable, Compute the meet operator for | |
975 | the existing value of the PHI node and the current PHI argument. */ | |
976 | if (e->flags & EDGE_EXECUTABLE) | |
977 | { | |
75a70cf9 | 978 | tree arg = gimple_phi_arg (phi, i)->def; |
b7e55469 | 979 | prop_value_t arg_val = get_value_for_expr (arg, false); |
4ee9c684 | 980 | |
88dbf20f | 981 | ccp_lattice_meet (&new_val, &arg_val); |
4ee9c684 | 982 | |
41511585 | 983 | if (dump_file && (dump_flags & TDF_DETAILS)) |
984 | { | |
985 | fprintf (dump_file, "\t"); | |
88dbf20f | 986 | print_generic_expr (dump_file, arg, dump_flags); |
987 | dump_lattice_value (dump_file, "\tValue: ", arg_val); | |
41511585 | 988 | fprintf (dump_file, "\n"); |
989 | } | |
4ee9c684 | 990 | |
41511585 | 991 | if (new_val.lattice_val == VARYING) |
992 | break; | |
993 | } | |
994 | } | |
4ee9c684 | 995 | |
996 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
41511585 | 997 | { |
998 | dump_lattice_value (dump_file, "\n PHI node value: ", new_val); | |
999 | fprintf (dump_file, "\n\n"); | |
1000 | } | |
1001 | ||
bfa30570 | 1002 | /* Make the transition to the new value. */ |
75a70cf9 | 1003 | if (set_lattice_value (gimple_phi_result (phi), new_val)) |
41511585 | 1004 | { |
1005 | if (new_val.lattice_val == VARYING) | |
1006 | return SSA_PROP_VARYING; | |
1007 | else | |
1008 | return SSA_PROP_INTERESTING; | |
1009 | } | |
1010 | else | |
1011 | return SSA_PROP_NOT_INTERESTING; | |
4ee9c684 | 1012 | } |
1013 | ||
15d138c9 | 1014 | /* Return the constant value for OP or OP otherwise. */ |
00f4f705 | 1015 | |
1016 | static tree | |
15d138c9 | 1017 | valueize_op (tree op) |
00f4f705 | 1018 | { |
00f4f705 | 1019 | if (TREE_CODE (op) == SSA_NAME) |
1020 | { | |
15d138c9 | 1021 | tree tem = get_constant_value (op); |
1022 | if (tem) | |
1023 | return tem; | |
00f4f705 | 1024 | } |
1025 | return op; | |
1026 | } | |
1027 | ||
41511585 | 1028 | /* CCP specific front-end to the non-destructive constant folding |
1029 | routines. | |
4ee9c684 | 1030 | |
1031 | Attempt to simplify the RHS of STMT knowing that one or more | |
1032 | operands are constants. | |
1033 | ||
1034 | If simplification is possible, return the simplified RHS, | |
75a70cf9 | 1035 | otherwise return the original RHS or NULL_TREE. */ |
4ee9c684 | 1036 | |
1037 | static tree | |
75a70cf9 | 1038 | ccp_fold (gimple stmt) |
4ee9c684 | 1039 | { |
389dd41b | 1040 | location_t loc = gimple_location (stmt); |
75a70cf9 | 1041 | switch (gimple_code (stmt)) |
88dbf20f | 1042 | { |
75a70cf9 | 1043 | case GIMPLE_COND: |
1044 | { | |
1045 | /* Handle comparison operators that can appear in GIMPLE form. */ | |
15d138c9 | 1046 | tree op0 = valueize_op (gimple_cond_lhs (stmt)); |
1047 | tree op1 = valueize_op (gimple_cond_rhs (stmt)); | |
75a70cf9 | 1048 | enum tree_code code = gimple_cond_code (stmt); |
389dd41b | 1049 | return fold_binary_loc (loc, code, boolean_type_node, op0, op1); |
75a70cf9 | 1050 | } |
4ee9c684 | 1051 | |
75a70cf9 | 1052 | case GIMPLE_SWITCH: |
1053 | { | |
15d138c9 | 1054 | /* Return the constant switch index. */ |
1055 | return valueize_op (gimple_switch_index (stmt)); | |
75a70cf9 | 1056 | } |
912f109f | 1057 | |
1d0b727d | 1058 | case GIMPLE_ASSIGN: |
1059 | case GIMPLE_CALL: | |
1060 | return gimple_fold_stmt_to_constant_1 (stmt, valueize_op); | |
04236c3a | 1061 | |
8782adcf | 1062 | default: |
1d0b727d | 1063 | gcc_unreachable (); |
8782adcf | 1064 | } |
8782adcf | 1065 | } |
75a70cf9 | 1066 | |
b7e55469 | 1067 | /* Apply the operation CODE in type TYPE to the value, mask pair |
1068 | RVAL and RMASK representing a value of type RTYPE and set | |
1069 | the value, mask pair *VAL and *MASK to the result. */ | |
1070 | ||
1071 | static void | |
1072 | bit_value_unop_1 (enum tree_code code, tree type, | |
1073 | double_int *val, double_int *mask, | |
1074 | tree rtype, double_int rval, double_int rmask) | |
1075 | { | |
1076 | switch (code) | |
1077 | { | |
1078 | case BIT_NOT_EXPR: | |
1079 | *mask = rmask; | |
cf8f0e63 | 1080 | *val = ~rval; |
b7e55469 | 1081 | break; |
1082 | ||
1083 | case NEGATE_EXPR: | |
1084 | { | |
1085 | double_int temv, temm; | |
1086 | /* Return ~rval + 1. */ | |
1087 | bit_value_unop_1 (BIT_NOT_EXPR, type, &temv, &temm, type, rval, rmask); | |
1088 | bit_value_binop_1 (PLUS_EXPR, type, val, mask, | |
1089 | type, temv, temm, | |
1090 | type, double_int_one, double_int_zero); | |
1091 | break; | |
1092 | } | |
1093 | ||
1094 | CASE_CONVERT: | |
1095 | { | |
1096 | bool uns; | |
1097 | ||
1098 | /* First extend mask and value according to the original type. */ | |
85d86b55 | 1099 | uns = TYPE_UNSIGNED (rtype); |
cf8f0e63 | 1100 | *mask = rmask.ext (TYPE_PRECISION (rtype), uns); |
1101 | *val = rval.ext (TYPE_PRECISION (rtype), uns); | |
b7e55469 | 1102 | |
1103 | /* Then extend mask and value according to the target type. */ | |
85d86b55 | 1104 | uns = TYPE_UNSIGNED (type); |
cf8f0e63 | 1105 | *mask = (*mask).ext (TYPE_PRECISION (type), uns); |
1106 | *val = (*val).ext (TYPE_PRECISION (type), uns); | |
b7e55469 | 1107 | break; |
1108 | } | |
1109 | ||
1110 | default: | |
1111 | *mask = double_int_minus_one; | |
1112 | break; | |
1113 | } | |
1114 | } | |
1115 | ||
1116 | /* Apply the operation CODE in type TYPE to the value, mask pairs | |
1117 | R1VAL, R1MASK and R2VAL, R2MASK representing a values of type R1TYPE | |
1118 | and R2TYPE and set the value, mask pair *VAL and *MASK to the result. */ | |
1119 | ||
1120 | static void | |
1121 | bit_value_binop_1 (enum tree_code code, tree type, | |
1122 | double_int *val, double_int *mask, | |
1123 | tree r1type, double_int r1val, double_int r1mask, | |
1124 | tree r2type, double_int r2val, double_int r2mask) | |
1125 | { | |
85d86b55 | 1126 | bool uns = TYPE_UNSIGNED (type); |
b7e55469 | 1127 | /* Assume we'll get a constant result. Use an initial varying value, |
1128 | we fall back to varying in the end if necessary. */ | |
1129 | *mask = double_int_minus_one; | |
1130 | switch (code) | |
1131 | { | |
1132 | case BIT_AND_EXPR: | |
1133 | /* The mask is constant where there is a known not | |
1134 | set bit, (m1 | m2) & ((v1 | m1) & (v2 | m2)) */ | |
cf8f0e63 | 1135 | *mask = (r1mask | r2mask) & (r1val | r1mask) & (r2val | r2mask); |
1136 | *val = r1val & r2val; | |
b7e55469 | 1137 | break; |
1138 | ||
1139 | case BIT_IOR_EXPR: | |
1140 | /* The mask is constant where there is a known | |
1141 | set bit, (m1 | m2) & ~((v1 & ~m1) | (v2 & ~m2)). */ | |
cf8f0e63 | 1142 | *mask = (r1mask | r2mask) |
1143 | .and_not (r1val.and_not (r1mask) | r2val.and_not (r2mask)); | |
1144 | *val = r1val | r2val; | |
b7e55469 | 1145 | break; |
1146 | ||
1147 | case BIT_XOR_EXPR: | |
1148 | /* m1 | m2 */ | |
cf8f0e63 | 1149 | *mask = r1mask | r2mask; |
1150 | *val = r1val ^ r2val; | |
b7e55469 | 1151 | break; |
1152 | ||
1153 | case LROTATE_EXPR: | |
1154 | case RROTATE_EXPR: | |
cf8f0e63 | 1155 | if (r2mask.is_zero ()) |
b7e55469 | 1156 | { |
1157 | HOST_WIDE_INT shift = r2val.low; | |
1158 | if (code == RROTATE_EXPR) | |
1159 | shift = -shift; | |
cf8f0e63 | 1160 | *mask = r1mask.lrotate (shift, TYPE_PRECISION (type)); |
1161 | *val = r1val.lrotate (shift, TYPE_PRECISION (type)); | |
b7e55469 | 1162 | } |
1163 | break; | |
1164 | ||
1165 | case LSHIFT_EXPR: | |
1166 | case RSHIFT_EXPR: | |
1167 | /* ??? We can handle partially known shift counts if we know | |
1168 | its sign. That way we can tell that (x << (y | 8)) & 255 | |
1169 | is zero. */ | |
cf8f0e63 | 1170 | if (r2mask.is_zero ()) |
b7e55469 | 1171 | { |
1172 | HOST_WIDE_INT shift = r2val.low; | |
1173 | if (code == RSHIFT_EXPR) | |
1174 | shift = -shift; | |
1175 | /* We need to know if we are doing a left or a right shift | |
1176 | to properly shift in zeros for left shift and unsigned | |
1177 | right shifts and the sign bit for signed right shifts. | |
1178 | For signed right shifts we shift in varying in case | |
1179 | the sign bit was varying. */ | |
1180 | if (shift > 0) | |
1181 | { | |
cf8f0e63 | 1182 | *mask = r1mask.llshift (shift, TYPE_PRECISION (type)); |
1183 | *val = r1val.llshift (shift, TYPE_PRECISION (type)); | |
b7e55469 | 1184 | } |
1185 | else if (shift < 0) | |
1186 | { | |
1187 | shift = -shift; | |
cf8f0e63 | 1188 | *mask = r1mask.rshift (shift, TYPE_PRECISION (type), !uns); |
1189 | *val = r1val.rshift (shift, TYPE_PRECISION (type), !uns); | |
b7e55469 | 1190 | } |
1191 | else | |
1192 | { | |
1193 | *mask = r1mask; | |
1194 | *val = r1val; | |
1195 | } | |
1196 | } | |
1197 | break; | |
1198 | ||
1199 | case PLUS_EXPR: | |
1200 | case POINTER_PLUS_EXPR: | |
1201 | { | |
1202 | double_int lo, hi; | |
1203 | /* Do the addition with unknown bits set to zero, to give carry-ins of | |
1204 | zero wherever possible. */ | |
cf8f0e63 | 1205 | lo = r1val.and_not (r1mask) + r2val.and_not (r2mask); |
1206 | lo = lo.ext (TYPE_PRECISION (type), uns); | |
b7e55469 | 1207 | /* Do the addition with unknown bits set to one, to give carry-ins of |
1208 | one wherever possible. */ | |
cf8f0e63 | 1209 | hi = (r1val | r1mask) + (r2val | r2mask); |
1210 | hi = hi.ext (TYPE_PRECISION (type), uns); | |
b7e55469 | 1211 | /* Each bit in the result is known if (a) the corresponding bits in |
1212 | both inputs are known, and (b) the carry-in to that bit position | |
1213 | is known. We can check condition (b) by seeing if we got the same | |
1214 | result with minimised carries as with maximised carries. */ | |
cf8f0e63 | 1215 | *mask = r1mask | r2mask | (lo ^ hi); |
1216 | *mask = (*mask).ext (TYPE_PRECISION (type), uns); | |
b7e55469 | 1217 | /* It shouldn't matter whether we choose lo or hi here. */ |
1218 | *val = lo; | |
1219 | break; | |
1220 | } | |
1221 | ||
1222 | case MINUS_EXPR: | |
1223 | { | |
1224 | double_int temv, temm; | |
1225 | bit_value_unop_1 (NEGATE_EXPR, r2type, &temv, &temm, | |
1226 | r2type, r2val, r2mask); | |
1227 | bit_value_binop_1 (PLUS_EXPR, type, val, mask, | |
1228 | r1type, r1val, r1mask, | |
1229 | r2type, temv, temm); | |
1230 | break; | |
1231 | } | |
1232 | ||
1233 | case MULT_EXPR: | |
1234 | { | |
1235 | /* Just track trailing zeros in both operands and transfer | |
1236 | them to the other. */ | |
cf8f0e63 | 1237 | int r1tz = (r1val | r1mask).trailing_zeros (); |
1238 | int r2tz = (r2val | r2mask).trailing_zeros (); | |
b7e55469 | 1239 | if (r1tz + r2tz >= HOST_BITS_PER_DOUBLE_INT) |
1240 | { | |
1241 | *mask = double_int_zero; | |
1242 | *val = double_int_zero; | |
1243 | } | |
1244 | else if (r1tz + r2tz > 0) | |
1245 | { | |
cf8f0e63 | 1246 | *mask = ~double_int::mask (r1tz + r2tz); |
1247 | *mask = (*mask).ext (TYPE_PRECISION (type), uns); | |
b7e55469 | 1248 | *val = double_int_zero; |
1249 | } | |
1250 | break; | |
1251 | } | |
1252 | ||
1253 | case EQ_EXPR: | |
1254 | case NE_EXPR: | |
1255 | { | |
cf8f0e63 | 1256 | double_int m = r1mask | r2mask; |
1257 | if (r1val.and_not (m) != r2val.and_not (m)) | |
b7e55469 | 1258 | { |
1259 | *mask = double_int_zero; | |
1260 | *val = ((code == EQ_EXPR) ? double_int_zero : double_int_one); | |
1261 | } | |
1262 | else | |
1263 | { | |
1264 | /* We know the result of a comparison is always one or zero. */ | |
1265 | *mask = double_int_one; | |
1266 | *val = double_int_zero; | |
1267 | } | |
1268 | break; | |
1269 | } | |
1270 | ||
1271 | case GE_EXPR: | |
1272 | case GT_EXPR: | |
1273 | { | |
1274 | double_int tem = r1val; | |
1275 | r1val = r2val; | |
1276 | r2val = tem; | |
1277 | tem = r1mask; | |
1278 | r1mask = r2mask; | |
1279 | r2mask = tem; | |
1280 | code = swap_tree_comparison (code); | |
1281 | } | |
1282 | /* Fallthru. */ | |
1283 | case LT_EXPR: | |
1284 | case LE_EXPR: | |
1285 | { | |
1286 | int minmax, maxmin; | |
1287 | /* If the most significant bits are not known we know nothing. */ | |
cf8f0e63 | 1288 | if (r1mask.is_negative () || r2mask.is_negative ()) |
b7e55469 | 1289 | break; |
1290 | ||
90c0f5b7 | 1291 | /* For comparisons the signedness is in the comparison operands. */ |
85d86b55 | 1292 | uns = TYPE_UNSIGNED (r1type); |
90c0f5b7 | 1293 | |
b7e55469 | 1294 | /* If we know the most significant bits we know the values |
1295 | value ranges by means of treating varying bits as zero | |
1296 | or one. Do a cross comparison of the max/min pairs. */ | |
cf8f0e63 | 1297 | maxmin = (r1val | r1mask).cmp (r2val.and_not (r2mask), uns); |
1298 | minmax = r1val.and_not (r1mask).cmp (r2val | r2mask, uns); | |
b7e55469 | 1299 | if (maxmin < 0) /* r1 is less than r2. */ |
1300 | { | |
1301 | *mask = double_int_zero; | |
1302 | *val = double_int_one; | |
1303 | } | |
1304 | else if (minmax > 0) /* r1 is not less or equal to r2. */ | |
1305 | { | |
1306 | *mask = double_int_zero; | |
1307 | *val = double_int_zero; | |
1308 | } | |
1309 | else if (maxmin == minmax) /* r1 and r2 are equal. */ | |
1310 | { | |
1311 | /* This probably should never happen as we'd have | |
1312 | folded the thing during fully constant value folding. */ | |
1313 | *mask = double_int_zero; | |
1314 | *val = (code == LE_EXPR ? double_int_one : double_int_zero); | |
1315 | } | |
1316 | else | |
1317 | { | |
1318 | /* We know the result of a comparison is always one or zero. */ | |
1319 | *mask = double_int_one; | |
1320 | *val = double_int_zero; | |
1321 | } | |
1322 | break; | |
1323 | } | |
1324 | ||
1325 | default:; | |
1326 | } | |
1327 | } | |
1328 | ||
1329 | /* Return the propagation value when applying the operation CODE to | |
1330 | the value RHS yielding type TYPE. */ | |
1331 | ||
1332 | static prop_value_t | |
1333 | bit_value_unop (enum tree_code code, tree type, tree rhs) | |
1334 | { | |
1335 | prop_value_t rval = get_value_for_expr (rhs, true); | |
1336 | double_int value, mask; | |
1337 | prop_value_t val; | |
c91fedc5 | 1338 | |
1339 | if (rval.lattice_val == UNDEFINED) | |
1340 | return rval; | |
1341 | ||
b7e55469 | 1342 | gcc_assert ((rval.lattice_val == CONSTANT |
1343 | && TREE_CODE (rval.value) == INTEGER_CST) | |
cf8f0e63 | 1344 | || rval.mask.is_minus_one ()); |
b7e55469 | 1345 | bit_value_unop_1 (code, type, &value, &mask, |
1346 | TREE_TYPE (rhs), value_to_double_int (rval), rval.mask); | |
cf8f0e63 | 1347 | if (!mask.is_minus_one ()) |
b7e55469 | 1348 | { |
1349 | val.lattice_val = CONSTANT; | |
1350 | val.mask = mask; | |
1351 | /* ??? Delay building trees here. */ | |
1352 | val.value = double_int_to_tree (type, value); | |
1353 | } | |
1354 | else | |
1355 | { | |
1356 | val.lattice_val = VARYING; | |
1357 | val.value = NULL_TREE; | |
1358 | val.mask = double_int_minus_one; | |
1359 | } | |
1360 | return val; | |
1361 | } | |
1362 | ||
1363 | /* Return the propagation value when applying the operation CODE to | |
1364 | the values RHS1 and RHS2 yielding type TYPE. */ | |
1365 | ||
1366 | static prop_value_t | |
1367 | bit_value_binop (enum tree_code code, tree type, tree rhs1, tree rhs2) | |
1368 | { | |
1369 | prop_value_t r1val = get_value_for_expr (rhs1, true); | |
1370 | prop_value_t r2val = get_value_for_expr (rhs2, true); | |
1371 | double_int value, mask; | |
1372 | prop_value_t val; | |
c91fedc5 | 1373 | |
1374 | if (r1val.lattice_val == UNDEFINED | |
1375 | || r2val.lattice_val == UNDEFINED) | |
1376 | { | |
1377 | val.lattice_val = VARYING; | |
1378 | val.value = NULL_TREE; | |
1379 | val.mask = double_int_minus_one; | |
1380 | return val; | |
1381 | } | |
1382 | ||
b7e55469 | 1383 | gcc_assert ((r1val.lattice_val == CONSTANT |
1384 | && TREE_CODE (r1val.value) == INTEGER_CST) | |
cf8f0e63 | 1385 | || r1val.mask.is_minus_one ()); |
b7e55469 | 1386 | gcc_assert ((r2val.lattice_val == CONSTANT |
1387 | && TREE_CODE (r2val.value) == INTEGER_CST) | |
cf8f0e63 | 1388 | || r2val.mask.is_minus_one ()); |
b7e55469 | 1389 | bit_value_binop_1 (code, type, &value, &mask, |
1390 | TREE_TYPE (rhs1), value_to_double_int (r1val), r1val.mask, | |
1391 | TREE_TYPE (rhs2), value_to_double_int (r2val), r2val.mask); | |
cf8f0e63 | 1392 | if (!mask.is_minus_one ()) |
b7e55469 | 1393 | { |
1394 | val.lattice_val = CONSTANT; | |
1395 | val.mask = mask; | |
1396 | /* ??? Delay building trees here. */ | |
1397 | val.value = double_int_to_tree (type, value); | |
1398 | } | |
1399 | else | |
1400 | { | |
1401 | val.lattice_val = VARYING; | |
1402 | val.value = NULL_TREE; | |
1403 | val.mask = double_int_minus_one; | |
1404 | } | |
1405 | return val; | |
1406 | } | |
1407 | ||
fca0886c | 1408 | /* Return the propagation value when applying __builtin_assume_aligned to |
1409 | its arguments. */ | |
1410 | ||
1411 | static prop_value_t | |
1412 | bit_value_assume_aligned (gimple stmt) | |
1413 | { | |
1414 | tree ptr = gimple_call_arg (stmt, 0), align, misalign = NULL_TREE; | |
1415 | tree type = TREE_TYPE (ptr); | |
1416 | unsigned HOST_WIDE_INT aligni, misaligni = 0; | |
1417 | prop_value_t ptrval = get_value_for_expr (ptr, true); | |
1418 | prop_value_t alignval; | |
1419 | double_int value, mask; | |
1420 | prop_value_t val; | |
1421 | if (ptrval.lattice_val == UNDEFINED) | |
1422 | return ptrval; | |
1423 | gcc_assert ((ptrval.lattice_val == CONSTANT | |
1424 | && TREE_CODE (ptrval.value) == INTEGER_CST) | |
cf8f0e63 | 1425 | || ptrval.mask.is_minus_one ()); |
fca0886c | 1426 | align = gimple_call_arg (stmt, 1); |
1427 | if (!host_integerp (align, 1)) | |
1428 | return ptrval; | |
1429 | aligni = tree_low_cst (align, 1); | |
1430 | if (aligni <= 1 | |
1431 | || (aligni & (aligni - 1)) != 0) | |
1432 | return ptrval; | |
1433 | if (gimple_call_num_args (stmt) > 2) | |
1434 | { | |
1435 | misalign = gimple_call_arg (stmt, 2); | |
1436 | if (!host_integerp (misalign, 1)) | |
1437 | return ptrval; | |
1438 | misaligni = tree_low_cst (misalign, 1); | |
1439 | if (misaligni >= aligni) | |
1440 | return ptrval; | |
1441 | } | |
1442 | align = build_int_cst_type (type, -aligni); | |
1443 | alignval = get_value_for_expr (align, true); | |
1444 | bit_value_binop_1 (BIT_AND_EXPR, type, &value, &mask, | |
1445 | type, value_to_double_int (ptrval), ptrval.mask, | |
1446 | type, value_to_double_int (alignval), alignval.mask); | |
cf8f0e63 | 1447 | if (!mask.is_minus_one ()) |
fca0886c | 1448 | { |
1449 | val.lattice_val = CONSTANT; | |
1450 | val.mask = mask; | |
1451 | gcc_assert ((mask.low & (aligni - 1)) == 0); | |
1452 | gcc_assert ((value.low & (aligni - 1)) == 0); | |
1453 | value.low |= misaligni; | |
1454 | /* ??? Delay building trees here. */ | |
1455 | val.value = double_int_to_tree (type, value); | |
1456 | } | |
1457 | else | |
1458 | { | |
1459 | val.lattice_val = VARYING; | |
1460 | val.value = NULL_TREE; | |
1461 | val.mask = double_int_minus_one; | |
1462 | } | |
1463 | return val; | |
1464 | } | |
1465 | ||
75a70cf9 | 1466 | /* Evaluate statement STMT. |
1467 | Valid only for assignments, calls, conditionals, and switches. */ | |
4ee9c684 | 1468 | |
88dbf20f | 1469 | static prop_value_t |
75a70cf9 | 1470 | evaluate_stmt (gimple stmt) |
4ee9c684 | 1471 | { |
88dbf20f | 1472 | prop_value_t val; |
4f61cce6 | 1473 | tree simplified = NULL_TREE; |
88dbf20f | 1474 | ccp_lattice_t likelyvalue = likely_value (stmt); |
b7e55469 | 1475 | bool is_constant = false; |
581bf1c2 | 1476 | unsigned int align; |
88dbf20f | 1477 | |
b7e55469 | 1478 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1479 | { | |
1480 | fprintf (dump_file, "which is likely "); | |
1481 | switch (likelyvalue) | |
1482 | { | |
1483 | case CONSTANT: | |
1484 | fprintf (dump_file, "CONSTANT"); | |
1485 | break; | |
1486 | case UNDEFINED: | |
1487 | fprintf (dump_file, "UNDEFINED"); | |
1488 | break; | |
1489 | case VARYING: | |
1490 | fprintf (dump_file, "VARYING"); | |
1491 | break; | |
1492 | default:; | |
1493 | } | |
1494 | fprintf (dump_file, "\n"); | |
1495 | } | |
add6ee5e | 1496 | |
4ee9c684 | 1497 | /* If the statement is likely to have a CONSTANT result, then try |
1498 | to fold the statement to determine the constant value. */ | |
75a70cf9 | 1499 | /* FIXME. This is the only place that we call ccp_fold. |
1500 | Since likely_value never returns CONSTANT for calls, we will | |
1501 | not attempt to fold them, including builtins that may profit. */ | |
4ee9c684 | 1502 | if (likelyvalue == CONSTANT) |
b7e55469 | 1503 | { |
1504 | fold_defer_overflow_warnings (); | |
1505 | simplified = ccp_fold (stmt); | |
1506 | is_constant = simplified && is_gimple_min_invariant (simplified); | |
1507 | fold_undefer_overflow_warnings (is_constant, stmt, 0); | |
1508 | if (is_constant) | |
1509 | { | |
1510 | /* The statement produced a constant value. */ | |
1511 | val.lattice_val = CONSTANT; | |
1512 | val.value = simplified; | |
1513 | val.mask = double_int_zero; | |
1514 | } | |
1515 | } | |
4ee9c684 | 1516 | /* If the statement is likely to have a VARYING result, then do not |
1517 | bother folding the statement. */ | |
04236c3a | 1518 | else if (likelyvalue == VARYING) |
75a70cf9 | 1519 | { |
590c3166 | 1520 | enum gimple_code code = gimple_code (stmt); |
75a70cf9 | 1521 | if (code == GIMPLE_ASSIGN) |
1522 | { | |
1523 | enum tree_code subcode = gimple_assign_rhs_code (stmt); | |
48e1416a | 1524 | |
75a70cf9 | 1525 | /* Other cases cannot satisfy is_gimple_min_invariant |
1526 | without folding. */ | |
1527 | if (get_gimple_rhs_class (subcode) == GIMPLE_SINGLE_RHS) | |
1528 | simplified = gimple_assign_rhs1 (stmt); | |
1529 | } | |
1530 | else if (code == GIMPLE_SWITCH) | |
1531 | simplified = gimple_switch_index (stmt); | |
1532 | else | |
a65c4d64 | 1533 | /* These cannot satisfy is_gimple_min_invariant without folding. */ |
1534 | gcc_assert (code == GIMPLE_CALL || code == GIMPLE_COND); | |
b7e55469 | 1535 | is_constant = simplified && is_gimple_min_invariant (simplified); |
1536 | if (is_constant) | |
1537 | { | |
1538 | /* The statement produced a constant value. */ | |
1539 | val.lattice_val = CONSTANT; | |
1540 | val.value = simplified; | |
1541 | val.mask = double_int_zero; | |
1542 | } | |
75a70cf9 | 1543 | } |
4ee9c684 | 1544 | |
b7e55469 | 1545 | /* Resort to simplification for bitwise tracking. */ |
1546 | if (flag_tree_bit_ccp | |
939514e9 | 1547 | && (likelyvalue == CONSTANT || is_gimple_call (stmt)) |
b7e55469 | 1548 | && !is_constant) |
912f109f | 1549 | { |
b7e55469 | 1550 | enum gimple_code code = gimple_code (stmt); |
1551 | val.lattice_val = VARYING; | |
1552 | val.value = NULL_TREE; | |
1553 | val.mask = double_int_minus_one; | |
1554 | if (code == GIMPLE_ASSIGN) | |
912f109f | 1555 | { |
b7e55469 | 1556 | enum tree_code subcode = gimple_assign_rhs_code (stmt); |
1557 | tree rhs1 = gimple_assign_rhs1 (stmt); | |
1558 | switch (get_gimple_rhs_class (subcode)) | |
1559 | { | |
1560 | case GIMPLE_SINGLE_RHS: | |
1561 | if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
1562 | || POINTER_TYPE_P (TREE_TYPE (rhs1))) | |
1563 | val = get_value_for_expr (rhs1, true); | |
1564 | break; | |
1565 | ||
1566 | case GIMPLE_UNARY_RHS: | |
1567 | if ((INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
1568 | || POINTER_TYPE_P (TREE_TYPE (rhs1))) | |
1569 | && (INTEGRAL_TYPE_P (gimple_expr_type (stmt)) | |
1570 | || POINTER_TYPE_P (gimple_expr_type (stmt)))) | |
1571 | val = bit_value_unop (subcode, gimple_expr_type (stmt), rhs1); | |
1572 | break; | |
1573 | ||
1574 | case GIMPLE_BINARY_RHS: | |
1575 | if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
1576 | || POINTER_TYPE_P (TREE_TYPE (rhs1))) | |
1577 | { | |
e47d81e0 | 1578 | tree lhs = gimple_assign_lhs (stmt); |
b7e55469 | 1579 | tree rhs2 = gimple_assign_rhs2 (stmt); |
1580 | val = bit_value_binop (subcode, | |
e47d81e0 | 1581 | TREE_TYPE (lhs), rhs1, rhs2); |
b7e55469 | 1582 | } |
1583 | break; | |
1584 | ||
1585 | default:; | |
1586 | } | |
912f109f | 1587 | } |
b7e55469 | 1588 | else if (code == GIMPLE_COND) |
1589 | { | |
1590 | enum tree_code code = gimple_cond_code (stmt); | |
1591 | tree rhs1 = gimple_cond_lhs (stmt); | |
1592 | tree rhs2 = gimple_cond_rhs (stmt); | |
1593 | if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
1594 | || POINTER_TYPE_P (TREE_TYPE (rhs1))) | |
1595 | val = bit_value_binop (code, TREE_TYPE (rhs1), rhs1, rhs2); | |
1596 | } | |
0b4f0116 | 1597 | else if (gimple_call_builtin_p (stmt, BUILT_IN_NORMAL)) |
153c3b50 | 1598 | { |
0b4f0116 | 1599 | tree fndecl = gimple_call_fndecl (stmt); |
153c3b50 | 1600 | switch (DECL_FUNCTION_CODE (fndecl)) |
1601 | { | |
1602 | case BUILT_IN_MALLOC: | |
1603 | case BUILT_IN_REALLOC: | |
1604 | case BUILT_IN_CALLOC: | |
939514e9 | 1605 | case BUILT_IN_STRDUP: |
1606 | case BUILT_IN_STRNDUP: | |
153c3b50 | 1607 | val.lattice_val = CONSTANT; |
1608 | val.value = build_int_cst (TREE_TYPE (gimple_get_lhs (stmt)), 0); | |
cf8f0e63 | 1609 | val.mask = double_int::from_shwi |
153c3b50 | 1610 | (~(((HOST_WIDE_INT) MALLOC_ABI_ALIGNMENT) |
1611 | / BITS_PER_UNIT - 1)); | |
1612 | break; | |
1613 | ||
1614 | case BUILT_IN_ALLOCA: | |
581bf1c2 | 1615 | case BUILT_IN_ALLOCA_WITH_ALIGN: |
1616 | align = (DECL_FUNCTION_CODE (fndecl) == BUILT_IN_ALLOCA_WITH_ALIGN | |
1617 | ? TREE_INT_CST_LOW (gimple_call_arg (stmt, 1)) | |
1618 | : BIGGEST_ALIGNMENT); | |
153c3b50 | 1619 | val.lattice_val = CONSTANT; |
1620 | val.value = build_int_cst (TREE_TYPE (gimple_get_lhs (stmt)), 0); | |
cf8f0e63 | 1621 | val.mask = double_int::from_shwi (~(((HOST_WIDE_INT) align) |
1622 | / BITS_PER_UNIT - 1)); | |
153c3b50 | 1623 | break; |
1624 | ||
939514e9 | 1625 | /* These builtins return their first argument, unmodified. */ |
1626 | case BUILT_IN_MEMCPY: | |
1627 | case BUILT_IN_MEMMOVE: | |
1628 | case BUILT_IN_MEMSET: | |
1629 | case BUILT_IN_STRCPY: | |
1630 | case BUILT_IN_STRNCPY: | |
1631 | case BUILT_IN_MEMCPY_CHK: | |
1632 | case BUILT_IN_MEMMOVE_CHK: | |
1633 | case BUILT_IN_MEMSET_CHK: | |
1634 | case BUILT_IN_STRCPY_CHK: | |
1635 | case BUILT_IN_STRNCPY_CHK: | |
1636 | val = get_value_for_expr (gimple_call_arg (stmt, 0), true); | |
1637 | break; | |
1638 | ||
fca0886c | 1639 | case BUILT_IN_ASSUME_ALIGNED: |
1640 | val = bit_value_assume_aligned (stmt); | |
1641 | break; | |
1642 | ||
153c3b50 | 1643 | default:; |
1644 | } | |
1645 | } | |
b7e55469 | 1646 | is_constant = (val.lattice_val == CONSTANT); |
912f109f | 1647 | } |
1648 | ||
b7e55469 | 1649 | if (!is_constant) |
4ee9c684 | 1650 | { |
1651 | /* The statement produced a nonconstant value. If the statement | |
88dbf20f | 1652 | had UNDEFINED operands, then the result of the statement |
1653 | should be UNDEFINED. Otherwise, the statement is VARYING. */ | |
bfa30570 | 1654 | if (likelyvalue == UNDEFINED) |
b7e55469 | 1655 | { |
1656 | val.lattice_val = likelyvalue; | |
1657 | val.mask = double_int_zero; | |
1658 | } | |
b765fa12 | 1659 | else |
b7e55469 | 1660 | { |
1661 | val.lattice_val = VARYING; | |
1662 | val.mask = double_int_minus_one; | |
1663 | } | |
b765fa12 | 1664 | |
88dbf20f | 1665 | val.value = NULL_TREE; |
4ee9c684 | 1666 | } |
41511585 | 1667 | |
1668 | return val; | |
4ee9c684 | 1669 | } |
1670 | ||
494bbaae | 1671 | typedef hash_table <pointer_hash <gimple_statement_d> > gimple_htab; |
2b15d2ba | 1672 | |
582a80ed | 1673 | /* Given a BUILT_IN_STACK_SAVE value SAVED_VAL, insert a clobber of VAR before |
1674 | each matching BUILT_IN_STACK_RESTORE. Mark visited phis in VISITED. */ | |
1675 | ||
1676 | static void | |
2b15d2ba | 1677 | insert_clobber_before_stack_restore (tree saved_val, tree var, |
1678 | gimple_htab *visited) | |
582a80ed | 1679 | { |
1680 | gimple stmt, clobber_stmt; | |
1681 | tree clobber; | |
1682 | imm_use_iterator iter; | |
1683 | gimple_stmt_iterator i; | |
1684 | gimple *slot; | |
1685 | ||
1686 | FOR_EACH_IMM_USE_STMT (stmt, iter, saved_val) | |
1687 | if (gimple_call_builtin_p (stmt, BUILT_IN_STACK_RESTORE)) | |
1688 | { | |
f1f41a6c | 1689 | clobber = build_constructor (TREE_TYPE (var), |
1690 | NULL); | |
582a80ed | 1691 | TREE_THIS_VOLATILE (clobber) = 1; |
1692 | clobber_stmt = gimple_build_assign (var, clobber); | |
1693 | ||
1694 | i = gsi_for_stmt (stmt); | |
1695 | gsi_insert_before (&i, clobber_stmt, GSI_SAME_STMT); | |
1696 | } | |
1697 | else if (gimple_code (stmt) == GIMPLE_PHI) | |
1698 | { | |
2b15d2ba | 1699 | if (!visited->is_created ()) |
1700 | visited->create (10); | |
582a80ed | 1701 | |
2b15d2ba | 1702 | slot = visited->find_slot (stmt, INSERT); |
582a80ed | 1703 | if (*slot != NULL) |
1704 | continue; | |
1705 | ||
1706 | *slot = stmt; | |
1707 | insert_clobber_before_stack_restore (gimple_phi_result (stmt), var, | |
1708 | visited); | |
1709 | } | |
1710 | else | |
1711 | gcc_assert (is_gimple_debug (stmt)); | |
1712 | } | |
1713 | ||
1714 | /* Advance the iterator to the previous non-debug gimple statement in the same | |
1715 | or dominating basic block. */ | |
1716 | ||
1717 | static inline void | |
1718 | gsi_prev_dom_bb_nondebug (gimple_stmt_iterator *i) | |
1719 | { | |
1720 | basic_block dom; | |
1721 | ||
1722 | gsi_prev_nondebug (i); | |
1723 | while (gsi_end_p (*i)) | |
1724 | { | |
1725 | dom = get_immediate_dominator (CDI_DOMINATORS, i->bb); | |
1726 | if (dom == NULL || dom == ENTRY_BLOCK_PTR) | |
1727 | return; | |
1728 | ||
1729 | *i = gsi_last_bb (dom); | |
1730 | } | |
1731 | } | |
1732 | ||
1733 | /* Find a BUILT_IN_STACK_SAVE dominating gsi_stmt (I), and insert | |
1543f720 | 1734 | a clobber of VAR before each matching BUILT_IN_STACK_RESTORE. |
1735 | ||
1736 | It is possible that BUILT_IN_STACK_SAVE cannot be find in a dominator when a | |
1737 | previous pass (such as DOM) duplicated it along multiple paths to a BB. In | |
1738 | that case the function gives up without inserting the clobbers. */ | |
582a80ed | 1739 | |
1740 | static void | |
1741 | insert_clobbers_for_var (gimple_stmt_iterator i, tree var) | |
1742 | { | |
582a80ed | 1743 | gimple stmt; |
1744 | tree saved_val; | |
2b15d2ba | 1745 | gimple_htab visited; |
582a80ed | 1746 | |
1543f720 | 1747 | for (; !gsi_end_p (i); gsi_prev_dom_bb_nondebug (&i)) |
582a80ed | 1748 | { |
1749 | stmt = gsi_stmt (i); | |
1750 | ||
1751 | if (!gimple_call_builtin_p (stmt, BUILT_IN_STACK_SAVE)) | |
1752 | continue; | |
582a80ed | 1753 | |
1754 | saved_val = gimple_call_lhs (stmt); | |
1755 | if (saved_val == NULL_TREE) | |
1756 | continue; | |
1757 | ||
1758 | insert_clobber_before_stack_restore (saved_val, var, &visited); | |
1759 | break; | |
1760 | } | |
1761 | ||
2b15d2ba | 1762 | if (visited.is_created ()) |
1763 | visited.dispose (); | |
582a80ed | 1764 | } |
1765 | ||
581bf1c2 | 1766 | /* Detects a __builtin_alloca_with_align with constant size argument. Declares |
1767 | fixed-size array and returns the address, if found, otherwise returns | |
1768 | NULL_TREE. */ | |
9a65cc0a | 1769 | |
1770 | static tree | |
581bf1c2 | 1771 | fold_builtin_alloca_with_align (gimple stmt) |
9a65cc0a | 1772 | { |
1773 | unsigned HOST_WIDE_INT size, threshold, n_elem; | |
1774 | tree lhs, arg, block, var, elem_type, array_type; | |
9a65cc0a | 1775 | |
1776 | /* Get lhs. */ | |
1777 | lhs = gimple_call_lhs (stmt); | |
1778 | if (lhs == NULL_TREE) | |
1779 | return NULL_TREE; | |
1780 | ||
1781 | /* Detect constant argument. */ | |
1782 | arg = get_constant_value (gimple_call_arg (stmt, 0)); | |
6e93d308 | 1783 | if (arg == NULL_TREE |
1784 | || TREE_CODE (arg) != INTEGER_CST | |
9a65cc0a | 1785 | || !host_integerp (arg, 1)) |
1786 | return NULL_TREE; | |
6e93d308 | 1787 | |
9a65cc0a | 1788 | size = TREE_INT_CST_LOW (arg); |
1789 | ||
581bf1c2 | 1790 | /* Heuristic: don't fold large allocas. */ |
9a65cc0a | 1791 | threshold = (unsigned HOST_WIDE_INT)PARAM_VALUE (PARAM_LARGE_STACK_FRAME); |
581bf1c2 | 1792 | /* In case the alloca is located at function entry, it has the same lifetime |
1793 | as a declared array, so we allow a larger size. */ | |
9a65cc0a | 1794 | block = gimple_block (stmt); |
1795 | if (!(cfun->after_inlining | |
1796 | && TREE_CODE (BLOCK_SUPERCONTEXT (block)) == FUNCTION_DECL)) | |
1797 | threshold /= 10; | |
1798 | if (size > threshold) | |
1799 | return NULL_TREE; | |
1800 | ||
1801 | /* Declare array. */ | |
1802 | elem_type = build_nonstandard_integer_type (BITS_PER_UNIT, 1); | |
1803 | n_elem = size * 8 / BITS_PER_UNIT; | |
9a65cc0a | 1804 | array_type = build_array_type_nelts (elem_type, n_elem); |
1805 | var = create_tmp_var (array_type, NULL); | |
581bf1c2 | 1806 | DECL_ALIGN (var) = TREE_INT_CST_LOW (gimple_call_arg (stmt, 1)); |
3d4a0a4b | 1807 | { |
1808 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (lhs); | |
1809 | if (pi != NULL && !pi->pt.anything) | |
1810 | { | |
1811 | bool singleton_p; | |
1812 | unsigned uid; | |
1813 | singleton_p = pt_solution_singleton_p (&pi->pt, &uid); | |
1814 | gcc_assert (singleton_p); | |
1815 | SET_DECL_PT_UID (var, uid); | |
1816 | } | |
1817 | } | |
9a65cc0a | 1818 | |
1819 | /* Fold alloca to the address of the array. */ | |
1820 | return fold_convert (TREE_TYPE (lhs), build_fold_addr_expr (var)); | |
1821 | } | |
1822 | ||
6688f8ec | 1823 | /* Fold the stmt at *GSI with CCP specific information that propagating |
1824 | and regular folding does not catch. */ | |
1825 | ||
1826 | static bool | |
1827 | ccp_fold_stmt (gimple_stmt_iterator *gsi) | |
1828 | { | |
1829 | gimple stmt = gsi_stmt (*gsi); | |
6688f8ec | 1830 | |
94144e68 | 1831 | switch (gimple_code (stmt)) |
1832 | { | |
1833 | case GIMPLE_COND: | |
1834 | { | |
1835 | prop_value_t val; | |
1836 | /* Statement evaluation will handle type mismatches in constants | |
1837 | more gracefully than the final propagation. This allows us to | |
1838 | fold more conditionals here. */ | |
1839 | val = evaluate_stmt (stmt); | |
1840 | if (val.lattice_val != CONSTANT | |
cf8f0e63 | 1841 | || !val.mask.is_zero ()) |
94144e68 | 1842 | return false; |
1843 | ||
b7e55469 | 1844 | if (dump_file) |
1845 | { | |
1846 | fprintf (dump_file, "Folding predicate "); | |
1847 | print_gimple_expr (dump_file, stmt, 0, 0); | |
1848 | fprintf (dump_file, " to "); | |
1849 | print_generic_expr (dump_file, val.value, 0); | |
1850 | fprintf (dump_file, "\n"); | |
1851 | } | |
1852 | ||
94144e68 | 1853 | if (integer_zerop (val.value)) |
1854 | gimple_cond_make_false (stmt); | |
1855 | else | |
1856 | gimple_cond_make_true (stmt); | |
6688f8ec | 1857 | |
94144e68 | 1858 | return true; |
1859 | } | |
6688f8ec | 1860 | |
94144e68 | 1861 | case GIMPLE_CALL: |
1862 | { | |
1863 | tree lhs = gimple_call_lhs (stmt); | |
3064bb7b | 1864 | int flags = gimple_call_flags (stmt); |
15d138c9 | 1865 | tree val; |
94144e68 | 1866 | tree argt; |
1867 | bool changed = false; | |
1868 | unsigned i; | |
1869 | ||
1870 | /* If the call was folded into a constant make sure it goes | |
1871 | away even if we cannot propagate into all uses because of | |
1872 | type issues. */ | |
1873 | if (lhs | |
1874 | && TREE_CODE (lhs) == SSA_NAME | |
3064bb7b | 1875 | && (val = get_constant_value (lhs)) |
1876 | /* Don't optimize away calls that have side-effects. */ | |
1877 | && (flags & (ECF_CONST|ECF_PURE)) != 0 | |
1878 | && (flags & ECF_LOOPING_CONST_OR_PURE) == 0) | |
94144e68 | 1879 | { |
15d138c9 | 1880 | tree new_rhs = unshare_expr (val); |
338cce8f | 1881 | bool res; |
94144e68 | 1882 | if (!useless_type_conversion_p (TREE_TYPE (lhs), |
1883 | TREE_TYPE (new_rhs))) | |
1884 | new_rhs = fold_convert (TREE_TYPE (lhs), new_rhs); | |
338cce8f | 1885 | res = update_call_from_tree (gsi, new_rhs); |
1886 | gcc_assert (res); | |
94144e68 | 1887 | return true; |
1888 | } | |
1889 | ||
fb049fba | 1890 | /* Internal calls provide no argument types, so the extra laxity |
1891 | for normal calls does not apply. */ | |
1892 | if (gimple_call_internal_p (stmt)) | |
1893 | return false; | |
1894 | ||
581bf1c2 | 1895 | /* The heuristic of fold_builtin_alloca_with_align differs before and |
1896 | after inlining, so we don't require the arg to be changed into a | |
1897 | constant for folding, but just to be constant. */ | |
1898 | if (gimple_call_builtin_p (stmt, BUILT_IN_ALLOCA_WITH_ALIGN)) | |
9a65cc0a | 1899 | { |
581bf1c2 | 1900 | tree new_rhs = fold_builtin_alloca_with_align (stmt); |
6e93d308 | 1901 | if (new_rhs) |
1902 | { | |
1903 | bool res = update_call_from_tree (gsi, new_rhs); | |
582a80ed | 1904 | tree var = TREE_OPERAND (TREE_OPERAND (new_rhs, 0),0); |
6e93d308 | 1905 | gcc_assert (res); |
582a80ed | 1906 | insert_clobbers_for_var (*gsi, var); |
6e93d308 | 1907 | return true; |
1908 | } | |
9a65cc0a | 1909 | } |
1910 | ||
94144e68 | 1911 | /* Propagate into the call arguments. Compared to replace_uses_in |
1912 | this can use the argument slot types for type verification | |
1913 | instead of the current argument type. We also can safely | |
1914 | drop qualifiers here as we are dealing with constants anyway. */ | |
2de00a2d | 1915 | argt = TYPE_ARG_TYPES (gimple_call_fntype (stmt)); |
94144e68 | 1916 | for (i = 0; i < gimple_call_num_args (stmt) && argt; |
1917 | ++i, argt = TREE_CHAIN (argt)) | |
1918 | { | |
1919 | tree arg = gimple_call_arg (stmt, i); | |
1920 | if (TREE_CODE (arg) == SSA_NAME | |
15d138c9 | 1921 | && (val = get_constant_value (arg)) |
94144e68 | 1922 | && useless_type_conversion_p |
1923 | (TYPE_MAIN_VARIANT (TREE_VALUE (argt)), | |
15d138c9 | 1924 | TYPE_MAIN_VARIANT (TREE_TYPE (val)))) |
94144e68 | 1925 | { |
15d138c9 | 1926 | gimple_call_set_arg (stmt, i, unshare_expr (val)); |
94144e68 | 1927 | changed = true; |
1928 | } | |
1929 | } | |
e16f4c39 | 1930 | |
94144e68 | 1931 | return changed; |
1932 | } | |
6688f8ec | 1933 | |
6872bf3c | 1934 | case GIMPLE_ASSIGN: |
1935 | { | |
1936 | tree lhs = gimple_assign_lhs (stmt); | |
15d138c9 | 1937 | tree val; |
6872bf3c | 1938 | |
1939 | /* If we have a load that turned out to be constant replace it | |
1940 | as we cannot propagate into all uses in all cases. */ | |
1941 | if (gimple_assign_single_p (stmt) | |
1942 | && TREE_CODE (lhs) == SSA_NAME | |
15d138c9 | 1943 | && (val = get_constant_value (lhs))) |
6872bf3c | 1944 | { |
15d138c9 | 1945 | tree rhs = unshare_expr (val); |
6872bf3c | 1946 | if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs))) |
182cf5a9 | 1947 | rhs = fold_build1 (VIEW_CONVERT_EXPR, TREE_TYPE (lhs), rhs); |
6872bf3c | 1948 | gimple_assign_set_rhs_from_tree (gsi, rhs); |
1949 | return true; | |
1950 | } | |
1951 | ||
1952 | return false; | |
1953 | } | |
1954 | ||
94144e68 | 1955 | default: |
1956 | return false; | |
1957 | } | |
6688f8ec | 1958 | } |
1959 | ||
41511585 | 1960 | /* Visit the assignment statement STMT. Set the value of its LHS to the |
88dbf20f | 1961 | value computed by the RHS and store LHS in *OUTPUT_P. If STMT |
1962 | creates virtual definitions, set the value of each new name to that | |
75a70cf9 | 1963 | of the RHS (if we can derive a constant out of the RHS). |
1964 | Value-returning call statements also perform an assignment, and | |
1965 | are handled here. */ | |
4ee9c684 | 1966 | |
41511585 | 1967 | static enum ssa_prop_result |
75a70cf9 | 1968 | visit_assignment (gimple stmt, tree *output_p) |
4ee9c684 | 1969 | { |
88dbf20f | 1970 | prop_value_t val; |
88dbf20f | 1971 | enum ssa_prop_result retval; |
4ee9c684 | 1972 | |
75a70cf9 | 1973 | tree lhs = gimple_get_lhs (stmt); |
4ee9c684 | 1974 | |
75a70cf9 | 1975 | gcc_assert (gimple_code (stmt) != GIMPLE_CALL |
1976 | || gimple_call_lhs (stmt) != NULL_TREE); | |
1977 | ||
15d138c9 | 1978 | if (gimple_assign_single_p (stmt) |
1979 | && gimple_assign_rhs_code (stmt) == SSA_NAME) | |
1980 | /* For a simple copy operation, we copy the lattice values. */ | |
1981 | val = *get_value (gimple_assign_rhs1 (stmt)); | |
41511585 | 1982 | else |
75a70cf9 | 1983 | /* Evaluate the statement, which could be |
1984 | either a GIMPLE_ASSIGN or a GIMPLE_CALL. */ | |
04236c3a | 1985 | val = evaluate_stmt (stmt); |
4ee9c684 | 1986 | |
88dbf20f | 1987 | retval = SSA_PROP_NOT_INTERESTING; |
4ee9c684 | 1988 | |
41511585 | 1989 | /* Set the lattice value of the statement's output. */ |
88dbf20f | 1990 | if (TREE_CODE (lhs) == SSA_NAME) |
4ee9c684 | 1991 | { |
88dbf20f | 1992 | /* If STMT is an assignment to an SSA_NAME, we only have one |
1993 | value to set. */ | |
1994 | if (set_lattice_value (lhs, val)) | |
1995 | { | |
1996 | *output_p = lhs; | |
1997 | if (val.lattice_val == VARYING) | |
1998 | retval = SSA_PROP_VARYING; | |
1999 | else | |
2000 | retval = SSA_PROP_INTERESTING; | |
2001 | } | |
4ee9c684 | 2002 | } |
88dbf20f | 2003 | |
2004 | return retval; | |
4ee9c684 | 2005 | } |
2006 | ||
4ee9c684 | 2007 | |
41511585 | 2008 | /* Visit the conditional statement STMT. Return SSA_PROP_INTERESTING |
2009 | if it can determine which edge will be taken. Otherwise, return | |
2010 | SSA_PROP_VARYING. */ | |
2011 | ||
2012 | static enum ssa_prop_result | |
75a70cf9 | 2013 | visit_cond_stmt (gimple stmt, edge *taken_edge_p) |
4ee9c684 | 2014 | { |
88dbf20f | 2015 | prop_value_t val; |
41511585 | 2016 | basic_block block; |
2017 | ||
75a70cf9 | 2018 | block = gimple_bb (stmt); |
41511585 | 2019 | val = evaluate_stmt (stmt); |
b7e55469 | 2020 | if (val.lattice_val != CONSTANT |
cf8f0e63 | 2021 | || !val.mask.is_zero ()) |
b7e55469 | 2022 | return SSA_PROP_VARYING; |
41511585 | 2023 | |
2024 | /* Find which edge out of the conditional block will be taken and add it | |
2025 | to the worklist. If no single edge can be determined statically, | |
2026 | return SSA_PROP_VARYING to feed all the outgoing edges to the | |
2027 | propagation engine. */ | |
b7e55469 | 2028 | *taken_edge_p = find_taken_edge (block, val.value); |
41511585 | 2029 | if (*taken_edge_p) |
2030 | return SSA_PROP_INTERESTING; | |
2031 | else | |
2032 | return SSA_PROP_VARYING; | |
4ee9c684 | 2033 | } |
2034 | ||
4ee9c684 | 2035 | |
41511585 | 2036 | /* Evaluate statement STMT. If the statement produces an output value and |
2037 | its evaluation changes the lattice value of its output, return | |
2038 | SSA_PROP_INTERESTING and set *OUTPUT_P to the SSA_NAME holding the | |
2039 | output value. | |
48e1416a | 2040 | |
41511585 | 2041 | If STMT is a conditional branch and we can determine its truth |
2042 | value, set *TAKEN_EDGE_P accordingly. If STMT produces a varying | |
2043 | value, return SSA_PROP_VARYING. */ | |
4ee9c684 | 2044 | |
41511585 | 2045 | static enum ssa_prop_result |
75a70cf9 | 2046 | ccp_visit_stmt (gimple stmt, edge *taken_edge_p, tree *output_p) |
41511585 | 2047 | { |
41511585 | 2048 | tree def; |
2049 | ssa_op_iter iter; | |
4ee9c684 | 2050 | |
41511585 | 2051 | if (dump_file && (dump_flags & TDF_DETAILS)) |
4ee9c684 | 2052 | { |
88dbf20f | 2053 | fprintf (dump_file, "\nVisiting statement:\n"); |
75a70cf9 | 2054 | print_gimple_stmt (dump_file, stmt, 0, dump_flags); |
4ee9c684 | 2055 | } |
4ee9c684 | 2056 | |
75a70cf9 | 2057 | switch (gimple_code (stmt)) |
4ee9c684 | 2058 | { |
75a70cf9 | 2059 | case GIMPLE_ASSIGN: |
2060 | /* If the statement is an assignment that produces a single | |
2061 | output value, evaluate its RHS to see if the lattice value of | |
2062 | its output has changed. */ | |
2063 | return visit_assignment (stmt, output_p); | |
2064 | ||
2065 | case GIMPLE_CALL: | |
2066 | /* A value-returning call also performs an assignment. */ | |
2067 | if (gimple_call_lhs (stmt) != NULL_TREE) | |
2068 | return visit_assignment (stmt, output_p); | |
2069 | break; | |
2070 | ||
2071 | case GIMPLE_COND: | |
2072 | case GIMPLE_SWITCH: | |
2073 | /* If STMT is a conditional branch, see if we can determine | |
2074 | which branch will be taken. */ | |
2075 | /* FIXME. It appears that we should be able to optimize | |
2076 | computed GOTOs here as well. */ | |
2077 | return visit_cond_stmt (stmt, taken_edge_p); | |
2078 | ||
2079 | default: | |
2080 | break; | |
4ee9c684 | 2081 | } |
4ee9c684 | 2082 | |
41511585 | 2083 | /* Any other kind of statement is not interesting for constant |
2084 | propagation and, therefore, not worth simulating. */ | |
41511585 | 2085 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2086 | fprintf (dump_file, "No interesting values produced. Marked VARYING.\n"); | |
4ee9c684 | 2087 | |
41511585 | 2088 | /* Definitions made by statements other than assignments to |
2089 | SSA_NAMEs represent unknown modifications to their outputs. | |
2090 | Mark them VARYING. */ | |
88dbf20f | 2091 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS) |
2092 | { | |
b7e55469 | 2093 | prop_value_t v = { VARYING, NULL_TREE, { -1, (HOST_WIDE_INT) -1 } }; |
88dbf20f | 2094 | set_lattice_value (def, v); |
2095 | } | |
4ee9c684 | 2096 | |
41511585 | 2097 | return SSA_PROP_VARYING; |
2098 | } | |
4ee9c684 | 2099 | |
4ee9c684 | 2100 | |
88dbf20f | 2101 | /* Main entry point for SSA Conditional Constant Propagation. */ |
41511585 | 2102 | |
33a34f1e | 2103 | static unsigned int |
61207d43 | 2104 | do_ssa_ccp (void) |
41511585 | 2105 | { |
582a80ed | 2106 | unsigned int todo = 0; |
2107 | calculate_dominance_info (CDI_DOMINATORS); | |
41511585 | 2108 | ccp_initialize (); |
2109 | ssa_propagate (ccp_visit_stmt, ccp_visit_phi_node); | |
33a34f1e | 2110 | if (ccp_finalize ()) |
560965e9 | 2111 | todo = (TODO_cleanup_cfg | TODO_update_ssa); |
582a80ed | 2112 | free_dominance_info (CDI_DOMINATORS); |
2113 | return todo; | |
4ee9c684 | 2114 | } |
2115 | ||
5664499b | 2116 | |
2117 | static bool | |
41511585 | 2118 | gate_ccp (void) |
5664499b | 2119 | { |
41511585 | 2120 | return flag_tree_ccp != 0; |
5664499b | 2121 | } |
2122 | ||
4ee9c684 | 2123 | |
cbe8bda8 | 2124 | namespace { |
2125 | ||
2126 | const pass_data pass_data_ccp = | |
41511585 | 2127 | { |
cbe8bda8 | 2128 | GIMPLE_PASS, /* type */ |
2129 | "ccp", /* name */ | |
2130 | OPTGROUP_NONE, /* optinfo_flags */ | |
2131 | true, /* has_gate */ | |
2132 | true, /* has_execute */ | |
2133 | TV_TREE_CCP, /* tv_id */ | |
2134 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
2135 | 0, /* properties_provided */ | |
2136 | 0, /* properties_destroyed */ | |
2137 | 0, /* todo_flags_start */ | |
2138 | ( TODO_verify_ssa | TODO_update_address_taken | |
2139 | | TODO_verify_stmts ), /* todo_flags_finish */ | |
41511585 | 2140 | }; |
4ee9c684 | 2141 | |
cbe8bda8 | 2142 | class pass_ccp : public gimple_opt_pass |
2143 | { | |
2144 | public: | |
2145 | pass_ccp(gcc::context *ctxt) | |
2146 | : gimple_opt_pass(pass_data_ccp, ctxt) | |
2147 | {} | |
2148 | ||
2149 | /* opt_pass methods: */ | |
2150 | opt_pass * clone () { return new pass_ccp (ctxt_); } | |
2151 | bool gate () { return gate_ccp (); } | |
2152 | unsigned int execute () { return do_ssa_ccp (); } | |
2153 | ||
2154 | }; // class pass_ccp | |
2155 | ||
2156 | } // anon namespace | |
2157 | ||
2158 | gimple_opt_pass * | |
2159 | make_pass_ccp (gcc::context *ctxt) | |
2160 | { | |
2161 | return new pass_ccp (ctxt); | |
2162 | } | |
2163 | ||
4ee9c684 | 2164 | |
75a70cf9 | 2165 | |
bdd0e199 | 2166 | /* Try to optimize out __builtin_stack_restore. Optimize it out |
2167 | if there is another __builtin_stack_restore in the same basic | |
2168 | block and no calls or ASM_EXPRs are in between, or if this block's | |
2169 | only outgoing edge is to EXIT_BLOCK and there are no calls or | |
2170 | ASM_EXPRs after this __builtin_stack_restore. */ | |
2171 | ||
2172 | static tree | |
75a70cf9 | 2173 | optimize_stack_restore (gimple_stmt_iterator i) |
bdd0e199 | 2174 | { |
6ea999da | 2175 | tree callee; |
2176 | gimple stmt; | |
75a70cf9 | 2177 | |
2178 | basic_block bb = gsi_bb (i); | |
2179 | gimple call = gsi_stmt (i); | |
bdd0e199 | 2180 | |
75a70cf9 | 2181 | if (gimple_code (call) != GIMPLE_CALL |
2182 | || gimple_call_num_args (call) != 1 | |
2183 | || TREE_CODE (gimple_call_arg (call, 0)) != SSA_NAME | |
2184 | || !POINTER_TYPE_P (TREE_TYPE (gimple_call_arg (call, 0)))) | |
bdd0e199 | 2185 | return NULL_TREE; |
2186 | ||
75a70cf9 | 2187 | for (gsi_next (&i); !gsi_end_p (i); gsi_next (&i)) |
bdd0e199 | 2188 | { |
75a70cf9 | 2189 | stmt = gsi_stmt (i); |
2190 | if (gimple_code (stmt) == GIMPLE_ASM) | |
bdd0e199 | 2191 | return NULL_TREE; |
75a70cf9 | 2192 | if (gimple_code (stmt) != GIMPLE_CALL) |
bdd0e199 | 2193 | continue; |
2194 | ||
75a70cf9 | 2195 | callee = gimple_call_fndecl (stmt); |
c40a6f90 | 2196 | if (!callee |
2197 | || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL | |
2198 | /* All regular builtins are ok, just obviously not alloca. */ | |
581bf1c2 | 2199 | || DECL_FUNCTION_CODE (callee) == BUILT_IN_ALLOCA |
2200 | || DECL_FUNCTION_CODE (callee) == BUILT_IN_ALLOCA_WITH_ALIGN) | |
bdd0e199 | 2201 | return NULL_TREE; |
2202 | ||
2203 | if (DECL_FUNCTION_CODE (callee) == BUILT_IN_STACK_RESTORE) | |
6ea999da | 2204 | goto second_stack_restore; |
bdd0e199 | 2205 | } |
2206 | ||
6ea999da | 2207 | if (!gsi_end_p (i)) |
bdd0e199 | 2208 | return NULL_TREE; |
2209 | ||
6ea999da | 2210 | /* Allow one successor of the exit block, or zero successors. */ |
2211 | switch (EDGE_COUNT (bb->succs)) | |
2212 | { | |
2213 | case 0: | |
2214 | break; | |
2215 | case 1: | |
2216 | if (single_succ_edge (bb)->dest != EXIT_BLOCK_PTR) | |
2217 | return NULL_TREE; | |
2218 | break; | |
2219 | default: | |
2220 | return NULL_TREE; | |
2221 | } | |
2222 | second_stack_restore: | |
bdd0e199 | 2223 | |
6ea999da | 2224 | /* If there's exactly one use, then zap the call to __builtin_stack_save. |
2225 | If there are multiple uses, then the last one should remove the call. | |
2226 | In any case, whether the call to __builtin_stack_save can be removed | |
2227 | or not is irrelevant to removing the call to __builtin_stack_restore. */ | |
2228 | if (has_single_use (gimple_call_arg (call, 0))) | |
2229 | { | |
2230 | gimple stack_save = SSA_NAME_DEF_STMT (gimple_call_arg (call, 0)); | |
2231 | if (is_gimple_call (stack_save)) | |
2232 | { | |
2233 | callee = gimple_call_fndecl (stack_save); | |
2234 | if (callee | |
2235 | && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL | |
2236 | && DECL_FUNCTION_CODE (callee) == BUILT_IN_STACK_SAVE) | |
2237 | { | |
2238 | gimple_stmt_iterator stack_save_gsi; | |
2239 | tree rhs; | |
bdd0e199 | 2240 | |
6ea999da | 2241 | stack_save_gsi = gsi_for_stmt (stack_save); |
2242 | rhs = build_int_cst (TREE_TYPE (gimple_call_arg (call, 0)), 0); | |
2243 | update_call_from_tree (&stack_save_gsi, rhs); | |
2244 | } | |
2245 | } | |
2246 | } | |
bdd0e199 | 2247 | |
75a70cf9 | 2248 | /* No effect, so the statement will be deleted. */ |
bdd0e199 | 2249 | return integer_zero_node; |
2250 | } | |
75a70cf9 | 2251 | |
8a58ed0a | 2252 | /* If va_list type is a simple pointer and nothing special is needed, |
2253 | optimize __builtin_va_start (&ap, 0) into ap = __builtin_next_arg (0), | |
2254 | __builtin_va_end (&ap) out as NOP and __builtin_va_copy into a simple | |
2255 | pointer assignment. */ | |
2256 | ||
2257 | static tree | |
75a70cf9 | 2258 | optimize_stdarg_builtin (gimple call) |
8a58ed0a | 2259 | { |
5f57a8b1 | 2260 | tree callee, lhs, rhs, cfun_va_list; |
8a58ed0a | 2261 | bool va_list_simple_ptr; |
389dd41b | 2262 | location_t loc = gimple_location (call); |
8a58ed0a | 2263 | |
75a70cf9 | 2264 | if (gimple_code (call) != GIMPLE_CALL) |
8a58ed0a | 2265 | return NULL_TREE; |
2266 | ||
75a70cf9 | 2267 | callee = gimple_call_fndecl (call); |
5f57a8b1 | 2268 | |
2269 | cfun_va_list = targetm.fn_abi_va_list (callee); | |
2270 | va_list_simple_ptr = POINTER_TYPE_P (cfun_va_list) | |
2271 | && (TREE_TYPE (cfun_va_list) == void_type_node | |
2272 | || TREE_TYPE (cfun_va_list) == char_type_node); | |
2273 | ||
8a58ed0a | 2274 | switch (DECL_FUNCTION_CODE (callee)) |
2275 | { | |
2276 | case BUILT_IN_VA_START: | |
2277 | if (!va_list_simple_ptr | |
2278 | || targetm.expand_builtin_va_start != NULL | |
e7ed5dd7 | 2279 | || !builtin_decl_explicit_p (BUILT_IN_NEXT_ARG)) |
8a58ed0a | 2280 | return NULL_TREE; |
2281 | ||
75a70cf9 | 2282 | if (gimple_call_num_args (call) != 2) |
8a58ed0a | 2283 | return NULL_TREE; |
2284 | ||
75a70cf9 | 2285 | lhs = gimple_call_arg (call, 0); |
8a58ed0a | 2286 | if (!POINTER_TYPE_P (TREE_TYPE (lhs)) |
2287 | || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs))) | |
5f57a8b1 | 2288 | != TYPE_MAIN_VARIANT (cfun_va_list)) |
8a58ed0a | 2289 | return NULL_TREE; |
48e1416a | 2290 | |
389dd41b | 2291 | lhs = build_fold_indirect_ref_loc (loc, lhs); |
b9a16870 | 2292 | rhs = build_call_expr_loc (loc, builtin_decl_explicit (BUILT_IN_NEXT_ARG), |
75a70cf9 | 2293 | 1, integer_zero_node); |
389dd41b | 2294 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); |
8a58ed0a | 2295 | return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs); |
2296 | ||
2297 | case BUILT_IN_VA_COPY: | |
2298 | if (!va_list_simple_ptr) | |
2299 | return NULL_TREE; | |
2300 | ||
75a70cf9 | 2301 | if (gimple_call_num_args (call) != 2) |
8a58ed0a | 2302 | return NULL_TREE; |
2303 | ||
75a70cf9 | 2304 | lhs = gimple_call_arg (call, 0); |
8a58ed0a | 2305 | if (!POINTER_TYPE_P (TREE_TYPE (lhs)) |
2306 | || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs))) | |
5f57a8b1 | 2307 | != TYPE_MAIN_VARIANT (cfun_va_list)) |
8a58ed0a | 2308 | return NULL_TREE; |
2309 | ||
389dd41b | 2310 | lhs = build_fold_indirect_ref_loc (loc, lhs); |
75a70cf9 | 2311 | rhs = gimple_call_arg (call, 1); |
8a58ed0a | 2312 | if (TYPE_MAIN_VARIANT (TREE_TYPE (rhs)) |
5f57a8b1 | 2313 | != TYPE_MAIN_VARIANT (cfun_va_list)) |
8a58ed0a | 2314 | return NULL_TREE; |
2315 | ||
389dd41b | 2316 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); |
8a58ed0a | 2317 | return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs); |
2318 | ||
2319 | case BUILT_IN_VA_END: | |
75a70cf9 | 2320 | /* No effect, so the statement will be deleted. */ |
8a58ed0a | 2321 | return integer_zero_node; |
2322 | ||
2323 | default: | |
2324 | gcc_unreachable (); | |
2325 | } | |
2326 | } | |
75a70cf9 | 2327 | |
f87df69a | 2328 | /* Attemp to make the block of __builtin_unreachable I unreachable by changing |
2329 | the incoming jumps. Return true if at least one jump was changed. */ | |
2330 | ||
2331 | static bool | |
2332 | optimize_unreachable (gimple_stmt_iterator i) | |
2333 | { | |
2334 | basic_block bb = gsi_bb (i); | |
2335 | gimple_stmt_iterator gsi; | |
2336 | gimple stmt; | |
2337 | edge_iterator ei; | |
2338 | edge e; | |
2339 | bool ret; | |
2340 | ||
2341 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
2342 | { | |
2343 | stmt = gsi_stmt (gsi); | |
2344 | ||
2345 | if (is_gimple_debug (stmt)) | |
2346 | continue; | |
2347 | ||
2348 | if (gimple_code (stmt) == GIMPLE_LABEL) | |
2349 | { | |
2350 | /* Verify we do not need to preserve the label. */ | |
2351 | if (FORCED_LABEL (gimple_label_label (stmt))) | |
2352 | return false; | |
2353 | ||
2354 | continue; | |
2355 | } | |
2356 | ||
2357 | /* Only handle the case that __builtin_unreachable is the first statement | |
2358 | in the block. We rely on DCE to remove stmts without side-effects | |
2359 | before __builtin_unreachable. */ | |
2360 | if (gsi_stmt (gsi) != gsi_stmt (i)) | |
2361 | return false; | |
2362 | } | |
2363 | ||
2364 | ret = false; | |
2365 | FOR_EACH_EDGE (e, ei, bb->preds) | |
2366 | { | |
2367 | gsi = gsi_last_bb (e->src); | |
522f73a1 | 2368 | if (gsi_end_p (gsi)) |
2369 | continue; | |
f87df69a | 2370 | |
522f73a1 | 2371 | stmt = gsi_stmt (gsi); |
2372 | if (gimple_code (stmt) == GIMPLE_COND) | |
f87df69a | 2373 | { |
2374 | if (e->flags & EDGE_TRUE_VALUE) | |
2375 | gimple_cond_make_false (stmt); | |
2376 | else if (e->flags & EDGE_FALSE_VALUE) | |
2377 | gimple_cond_make_true (stmt); | |
2378 | else | |
2379 | gcc_unreachable (); | |
a03a52b4 | 2380 | update_stmt (stmt); |
f87df69a | 2381 | } |
2382 | else | |
2383 | { | |
2384 | /* Todo: handle other cases, f.i. switch statement. */ | |
2385 | continue; | |
2386 | } | |
2387 | ||
2388 | ret = true; | |
2389 | } | |
2390 | ||
2391 | return ret; | |
2392 | } | |
2393 | ||
4ee9c684 | 2394 | /* A simple pass that attempts to fold all builtin functions. This pass |
2395 | is run after we've propagated as many constants as we can. */ | |
2396 | ||
2a1990e9 | 2397 | static unsigned int |
4ee9c684 | 2398 | execute_fold_all_builtins (void) |
2399 | { | |
b36237eb | 2400 | bool cfg_changed = false; |
4ee9c684 | 2401 | basic_block bb; |
b1b7c0c4 | 2402 | unsigned int todoflags = 0; |
48e1416a | 2403 | |
4ee9c684 | 2404 | FOR_EACH_BB (bb) |
2405 | { | |
75a70cf9 | 2406 | gimple_stmt_iterator i; |
2407 | for (i = gsi_start_bb (bb); !gsi_end_p (i); ) | |
4ee9c684 | 2408 | { |
75a70cf9 | 2409 | gimple stmt, old_stmt; |
4ee9c684 | 2410 | tree callee, result; |
0a39fd54 | 2411 | enum built_in_function fcode; |
4ee9c684 | 2412 | |
75a70cf9 | 2413 | stmt = gsi_stmt (i); |
2414 | ||
2415 | if (gimple_code (stmt) != GIMPLE_CALL) | |
0a39fd54 | 2416 | { |
896a0c42 | 2417 | /* Remove all *ssaname_N ={v} {CLOBBER}; stmts, |
2418 | after the last GIMPLE DSE they aren't needed and might | |
2419 | unnecessarily keep the SSA_NAMEs live. */ | |
2420 | if (gimple_clobber_p (stmt)) | |
2421 | { | |
2422 | tree lhs = gimple_assign_lhs (stmt); | |
2423 | if (TREE_CODE (lhs) == MEM_REF | |
2424 | && TREE_CODE (TREE_OPERAND (lhs, 0)) == SSA_NAME) | |
2425 | { | |
2426 | unlink_stmt_vdef (stmt); | |
2427 | gsi_remove (&i, true); | |
2428 | release_defs (stmt); | |
2429 | continue; | |
2430 | } | |
2431 | } | |
75a70cf9 | 2432 | gsi_next (&i); |
0a39fd54 | 2433 | continue; |
2434 | } | |
75a70cf9 | 2435 | callee = gimple_call_fndecl (stmt); |
4ee9c684 | 2436 | if (!callee || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL) |
0a39fd54 | 2437 | { |
75a70cf9 | 2438 | gsi_next (&i); |
0a39fd54 | 2439 | continue; |
2440 | } | |
2441 | fcode = DECL_FUNCTION_CODE (callee); | |
4ee9c684 | 2442 | |
2d18b16d | 2443 | result = gimple_fold_builtin (stmt); |
5a4b7e1e | 2444 | |
2445 | if (result) | |
75a70cf9 | 2446 | gimple_remove_stmt_histograms (cfun, stmt); |
5a4b7e1e | 2447 | |
4ee9c684 | 2448 | if (!result) |
2449 | switch (DECL_FUNCTION_CODE (callee)) | |
2450 | { | |
2451 | case BUILT_IN_CONSTANT_P: | |
2452 | /* Resolve __builtin_constant_p. If it hasn't been | |
2453 | folded to integer_one_node by now, it's fairly | |
2454 | certain that the value simply isn't constant. */ | |
75a70cf9 | 2455 | result = integer_zero_node; |
4ee9c684 | 2456 | break; |
2457 | ||
fca0886c | 2458 | case BUILT_IN_ASSUME_ALIGNED: |
2459 | /* Remove __builtin_assume_aligned. */ | |
2460 | result = gimple_call_arg (stmt, 0); | |
2461 | break; | |
2462 | ||
bdd0e199 | 2463 | case BUILT_IN_STACK_RESTORE: |
75a70cf9 | 2464 | result = optimize_stack_restore (i); |
8a58ed0a | 2465 | if (result) |
2466 | break; | |
75a70cf9 | 2467 | gsi_next (&i); |
8a58ed0a | 2468 | continue; |
2469 | ||
f87df69a | 2470 | case BUILT_IN_UNREACHABLE: |
2471 | if (optimize_unreachable (i)) | |
2472 | cfg_changed = true; | |
2473 | break; | |
2474 | ||
8a58ed0a | 2475 | case BUILT_IN_VA_START: |
2476 | case BUILT_IN_VA_END: | |
2477 | case BUILT_IN_VA_COPY: | |
2478 | /* These shouldn't be folded before pass_stdarg. */ | |
75a70cf9 | 2479 | result = optimize_stdarg_builtin (stmt); |
bdd0e199 | 2480 | if (result) |
2481 | break; | |
2482 | /* FALLTHRU */ | |
2483 | ||
4ee9c684 | 2484 | default: |
75a70cf9 | 2485 | gsi_next (&i); |
4ee9c684 | 2486 | continue; |
2487 | } | |
2488 | ||
f87df69a | 2489 | if (result == NULL_TREE) |
2490 | break; | |
2491 | ||
4ee9c684 | 2492 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2493 | { | |
2494 | fprintf (dump_file, "Simplified\n "); | |
75a70cf9 | 2495 | print_gimple_stmt (dump_file, stmt, 0, dump_flags); |
4ee9c684 | 2496 | } |
2497 | ||
75a70cf9 | 2498 | old_stmt = stmt; |
75a70cf9 | 2499 | if (!update_call_from_tree (&i, result)) |
0fefde02 | 2500 | { |
2501 | gimplify_and_update_call_from_tree (&i, result); | |
2502 | todoflags |= TODO_update_address_taken; | |
2503 | } | |
de6ed584 | 2504 | |
75a70cf9 | 2505 | stmt = gsi_stmt (i); |
4c5fd53c | 2506 | update_stmt (stmt); |
de6ed584 | 2507 | |
75a70cf9 | 2508 | if (maybe_clean_or_replace_eh_stmt (old_stmt, stmt) |
2509 | && gimple_purge_dead_eh_edges (bb)) | |
b36237eb | 2510 | cfg_changed = true; |
4ee9c684 | 2511 | |
2512 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2513 | { | |
2514 | fprintf (dump_file, "to\n "); | |
75a70cf9 | 2515 | print_gimple_stmt (dump_file, stmt, 0, dump_flags); |
4ee9c684 | 2516 | fprintf (dump_file, "\n"); |
2517 | } | |
0a39fd54 | 2518 | |
2519 | /* Retry the same statement if it changed into another | |
2520 | builtin, there might be new opportunities now. */ | |
75a70cf9 | 2521 | if (gimple_code (stmt) != GIMPLE_CALL) |
0a39fd54 | 2522 | { |
75a70cf9 | 2523 | gsi_next (&i); |
0a39fd54 | 2524 | continue; |
2525 | } | |
75a70cf9 | 2526 | callee = gimple_call_fndecl (stmt); |
0a39fd54 | 2527 | if (!callee |
75a70cf9 | 2528 | || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL |
0a39fd54 | 2529 | || DECL_FUNCTION_CODE (callee) == fcode) |
75a70cf9 | 2530 | gsi_next (&i); |
4ee9c684 | 2531 | } |
2532 | } | |
48e1416a | 2533 | |
b36237eb | 2534 | /* Delete unreachable blocks. */ |
b1b7c0c4 | 2535 | if (cfg_changed) |
2536 | todoflags |= TODO_cleanup_cfg; | |
48e1416a | 2537 | |
b1b7c0c4 | 2538 | return todoflags; |
4ee9c684 | 2539 | } |
2540 | ||
41511585 | 2541 | |
cbe8bda8 | 2542 | namespace { |
2543 | ||
2544 | const pass_data pass_data_fold_builtins = | |
4ee9c684 | 2545 | { |
cbe8bda8 | 2546 | GIMPLE_PASS, /* type */ |
2547 | "fab", /* name */ | |
2548 | OPTGROUP_NONE, /* optinfo_flags */ | |
2549 | false, /* has_gate */ | |
2550 | true, /* has_execute */ | |
2551 | TV_NONE, /* tv_id */ | |
2552 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
2553 | 0, /* properties_provided */ | |
2554 | 0, /* properties_destroyed */ | |
2555 | 0, /* todo_flags_start */ | |
2556 | ( TODO_verify_ssa | TODO_update_ssa ), /* todo_flags_finish */ | |
4ee9c684 | 2557 | }; |
cbe8bda8 | 2558 | |
2559 | class pass_fold_builtins : public gimple_opt_pass | |
2560 | { | |
2561 | public: | |
2562 | pass_fold_builtins(gcc::context *ctxt) | |
2563 | : gimple_opt_pass(pass_data_fold_builtins, ctxt) | |
2564 | {} | |
2565 | ||
2566 | /* opt_pass methods: */ | |
2567 | opt_pass * clone () { return new pass_fold_builtins (ctxt_); } | |
2568 | unsigned int execute () { return execute_fold_all_builtins (); } | |
2569 | ||
2570 | }; // class pass_fold_builtins | |
2571 | ||
2572 | } // anon namespace | |
2573 | ||
2574 | gimple_opt_pass * | |
2575 | make_pass_fold_builtins (gcc::context *ctxt) | |
2576 | { | |
2577 | return new pass_fold_builtins (ctxt); | |
2578 | } |