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4ee9c684 | 1 | /* Conditional constant propagation pass for the GNU compiler. |
87c0a9fc | 2 | Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, |
3064bb7b | 3 | 2010, 2011, 2012 Free Software Foundation, Inc. |
4ee9c684 | 4 | Adapted from original RTL SSA-CCP by Daniel Berlin <dberlin@dberlin.org> |
5 | Adapted to GIMPLE trees by Diego Novillo <dnovillo@redhat.com> | |
6 | ||
7 | This file is part of GCC. | |
48e1416a | 8 | |
4ee9c684 | 9 | GCC is free software; you can redistribute it and/or modify it |
10 | under the terms of the GNU General Public License as published by the | |
8c4c00c1 | 11 | Free Software Foundation; either version 3, or (at your option) any |
4ee9c684 | 12 | later version. |
48e1416a | 13 | |
4ee9c684 | 14 | GCC is distributed in the hope that it will be useful, but WITHOUT |
15 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
16 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
17 | for more details. | |
48e1416a | 18 | |
4ee9c684 | 19 | You should have received a copy of the GNU General Public License |
8c4c00c1 | 20 | along with GCC; see the file COPYING3. If not see |
21 | <http://www.gnu.org/licenses/>. */ | |
4ee9c684 | 22 | |
88dbf20f | 23 | /* Conditional constant propagation (CCP) is based on the SSA |
24 | propagation engine (tree-ssa-propagate.c). Constant assignments of | |
25 | the form VAR = CST are propagated from the assignments into uses of | |
26 | VAR, which in turn may generate new constants. The simulation uses | |
27 | a four level lattice to keep track of constant values associated | |
28 | with SSA names. Given an SSA name V_i, it may take one of the | |
29 | following values: | |
30 | ||
bfa30570 | 31 | UNINITIALIZED -> the initial state of the value. This value |
32 | is replaced with a correct initial value | |
33 | the first time the value is used, so the | |
34 | rest of the pass does not need to care about | |
35 | it. Using this value simplifies initialization | |
36 | of the pass, and prevents us from needlessly | |
37 | scanning statements that are never reached. | |
88dbf20f | 38 | |
39 | UNDEFINED -> V_i is a local variable whose definition | |
40 | has not been processed yet. Therefore we | |
41 | don't yet know if its value is a constant | |
42 | or not. | |
43 | ||
44 | CONSTANT -> V_i has been found to hold a constant | |
45 | value C. | |
46 | ||
47 | VARYING -> V_i cannot take a constant value, or if it | |
48 | does, it is not possible to determine it | |
49 | at compile time. | |
50 | ||
51 | The core of SSA-CCP is in ccp_visit_stmt and ccp_visit_phi_node: | |
52 | ||
53 | 1- In ccp_visit_stmt, we are interested in assignments whose RHS | |
54 | evaluates into a constant and conditional jumps whose predicate | |
55 | evaluates into a boolean true or false. When an assignment of | |
56 | the form V_i = CONST is found, V_i's lattice value is set to | |
57 | CONSTANT and CONST is associated with it. This causes the | |
58 | propagation engine to add all the SSA edges coming out the | |
59 | assignment into the worklists, so that statements that use V_i | |
60 | can be visited. | |
61 | ||
62 | If the statement is a conditional with a constant predicate, we | |
63 | mark the outgoing edges as executable or not executable | |
64 | depending on the predicate's value. This is then used when | |
65 | visiting PHI nodes to know when a PHI argument can be ignored. | |
48e1416a | 66 | |
88dbf20f | 67 | |
68 | 2- In ccp_visit_phi_node, if all the PHI arguments evaluate to the | |
69 | same constant C, then the LHS of the PHI is set to C. This | |
70 | evaluation is known as the "meet operation". Since one of the | |
71 | goals of this evaluation is to optimistically return constant | |
72 | values as often as possible, it uses two main short cuts: | |
73 | ||
74 | - If an argument is flowing in through a non-executable edge, it | |
75 | is ignored. This is useful in cases like this: | |
76 | ||
77 | if (PRED) | |
78 | a_9 = 3; | |
79 | else | |
80 | a_10 = 100; | |
81 | a_11 = PHI (a_9, a_10) | |
82 | ||
83 | If PRED is known to always evaluate to false, then we can | |
84 | assume that a_11 will always take its value from a_10, meaning | |
85 | that instead of consider it VARYING (a_9 and a_10 have | |
86 | different values), we can consider it CONSTANT 100. | |
87 | ||
88 | - If an argument has an UNDEFINED value, then it does not affect | |
89 | the outcome of the meet operation. If a variable V_i has an | |
90 | UNDEFINED value, it means that either its defining statement | |
91 | hasn't been visited yet or V_i has no defining statement, in | |
92 | which case the original symbol 'V' is being used | |
93 | uninitialized. Since 'V' is a local variable, the compiler | |
94 | may assume any initial value for it. | |
95 | ||
96 | ||
97 | After propagation, every variable V_i that ends up with a lattice | |
98 | value of CONSTANT will have the associated constant value in the | |
99 | array CONST_VAL[i].VALUE. That is fed into substitute_and_fold for | |
100 | final substitution and folding. | |
101 | ||
4ee9c684 | 102 | References: |
103 | ||
104 | Constant propagation with conditional branches, | |
105 | Wegman and Zadeck, ACM TOPLAS 13(2):181-210. | |
106 | ||
107 | Building an Optimizing Compiler, | |
108 | Robert Morgan, Butterworth-Heinemann, 1998, Section 8.9. | |
109 | ||
110 | Advanced Compiler Design and Implementation, | |
111 | Steven Muchnick, Morgan Kaufmann, 1997, Section 12.6 */ | |
112 | ||
113 | #include "config.h" | |
114 | #include "system.h" | |
115 | #include "coretypes.h" | |
116 | #include "tm.h" | |
4ee9c684 | 117 | #include "tree.h" |
41511585 | 118 | #include "flags.h" |
4ee9c684 | 119 | #include "tm_p.h" |
4ee9c684 | 120 | #include "basic-block.h" |
41511585 | 121 | #include "function.h" |
ce084dfc | 122 | #include "gimple-pretty-print.h" |
41511585 | 123 | #include "tree-flow.h" |
4ee9c684 | 124 | #include "tree-pass.h" |
41511585 | 125 | #include "tree-ssa-propagate.h" |
5a4b7e1e | 126 | #include "value-prof.h" |
41511585 | 127 | #include "langhooks.h" |
8782adcf | 128 | #include "target.h" |
0b205f4c | 129 | #include "diagnostic-core.h" |
43fb76c1 | 130 | #include "dbgcnt.h" |
1d0b727d | 131 | #include "gimple-fold.h" |
9a65cc0a | 132 | #include "params.h" |
2b15d2ba | 133 | #include "hash-table.h" |
4ee9c684 | 134 | |
135 | ||
136 | /* Possible lattice values. */ | |
137 | typedef enum | |
138 | { | |
bfa30570 | 139 | UNINITIALIZED, |
4ee9c684 | 140 | UNDEFINED, |
141 | CONSTANT, | |
142 | VARYING | |
88dbf20f | 143 | } ccp_lattice_t; |
4ee9c684 | 144 | |
14f101cf | 145 | struct prop_value_d { |
146 | /* Lattice value. */ | |
147 | ccp_lattice_t lattice_val; | |
148 | ||
149 | /* Propagated value. */ | |
150 | tree value; | |
b7e55469 | 151 | |
152 | /* Mask that applies to the propagated value during CCP. For | |
153 | X with a CONSTANT lattice value X & ~mask == value & ~mask. */ | |
154 | double_int mask; | |
14f101cf | 155 | }; |
156 | ||
157 | typedef struct prop_value_d prop_value_t; | |
158 | ||
88dbf20f | 159 | /* Array of propagated constant values. After propagation, |
160 | CONST_VAL[I].VALUE holds the constant value for SSA_NAME(I). If | |
161 | the constant is held in an SSA name representing a memory store | |
4fb5e5ca | 162 | (i.e., a VDEF), CONST_VAL[I].MEM_REF will contain the actual |
163 | memory reference used to store (i.e., the LHS of the assignment | |
164 | doing the store). */ | |
20140406 | 165 | static prop_value_t *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: |
187 | fprintf (outf, "%sCONSTANT ", prefix); | |
b7e55469 | 188 | if (TREE_CODE (val.value) != INTEGER_CST |
cf8f0e63 | 189 | || val.mask.is_zero ()) |
b7e55469 | 190 | print_generic_expr (outf, val.value, dump_flags); |
191 | else | |
192 | { | |
cf8f0e63 | 193 | double_int cval = tree_to_double_int (val.value).and_not (val.mask); |
b7e55469 | 194 | fprintf (outf, "%sCONSTANT " HOST_WIDE_INT_PRINT_DOUBLE_HEX, |
195 | prefix, cval.high, cval.low); | |
196 | fprintf (outf, " (" HOST_WIDE_INT_PRINT_DOUBLE_HEX ")", | |
197 | val.mask.high, val.mask.low); | |
198 | } | |
41511585 | 199 | break; |
200 | default: | |
8c0963c4 | 201 | gcc_unreachable (); |
41511585 | 202 | } |
01406fc0 | 203 | } |
4ee9c684 | 204 | |
4ee9c684 | 205 | |
88dbf20f | 206 | /* Print lattice value VAL to stderr. */ |
207 | ||
208 | void debug_lattice_value (prop_value_t val); | |
209 | ||
4b987fac | 210 | DEBUG_FUNCTION void |
88dbf20f | 211 | debug_lattice_value (prop_value_t val) |
212 | { | |
213 | dump_lattice_value (stderr, "", val); | |
214 | fprintf (stderr, "\n"); | |
215 | } | |
4ee9c684 | 216 | |
4ee9c684 | 217 | |
88dbf20f | 218 | /* Compute a default value for variable VAR and store it in the |
219 | CONST_VAL array. The following rules are used to get default | |
220 | values: | |
01406fc0 | 221 | |
88dbf20f | 222 | 1- Global and static variables that are declared constant are |
223 | considered CONSTANT. | |
224 | ||
225 | 2- Any other value is considered UNDEFINED. This is useful when | |
41511585 | 226 | considering PHI nodes. PHI arguments that are undefined do not |
227 | change the constant value of the PHI node, which allows for more | |
88dbf20f | 228 | constants to be propagated. |
4ee9c684 | 229 | |
8883e700 | 230 | 3- Variables defined by statements other than assignments and PHI |
88dbf20f | 231 | nodes are considered VARYING. |
4ee9c684 | 232 | |
8883e700 | 233 | 4- Initial values of variables that are not GIMPLE registers are |
bfa30570 | 234 | considered VARYING. */ |
4ee9c684 | 235 | |
88dbf20f | 236 | static prop_value_t |
237 | get_default_value (tree var) | |
238 | { | |
b7e55469 | 239 | prop_value_t val = { UNINITIALIZED, NULL_TREE, { 0, 0 } }; |
8edeb88b | 240 | gimple stmt; |
241 | ||
242 | stmt = SSA_NAME_DEF_STMT (var); | |
243 | ||
244 | if (gimple_nop_p (stmt)) | |
4ee9c684 | 245 | { |
8edeb88b | 246 | /* Variables defined by an empty statement are those used |
247 | before being initialized. If VAR is a local variable, we | |
248 | can assume initially that it is UNDEFINED, otherwise we must | |
249 | consider it VARYING. */ | |
7c782c9b | 250 | if (!virtual_operand_p (var) |
251 | && TREE_CODE (SSA_NAME_VAR (var)) == VAR_DECL) | |
8edeb88b | 252 | val.lattice_val = UNDEFINED; |
253 | else | |
b7e55469 | 254 | { |
255 | val.lattice_val = VARYING; | |
256 | val.mask = double_int_minus_one; | |
257 | } | |
4ee9c684 | 258 | } |
8edeb88b | 259 | else if (is_gimple_assign (stmt) |
260 | /* Value-returning GIMPLE_CALL statements assign to | |
261 | a variable, and are treated similarly to GIMPLE_ASSIGN. */ | |
262 | || (is_gimple_call (stmt) | |
263 | && gimple_call_lhs (stmt) != NULL_TREE) | |
264 | || gimple_code (stmt) == GIMPLE_PHI) | |
41511585 | 265 | { |
8edeb88b | 266 | tree cst; |
267 | if (gimple_assign_single_p (stmt) | |
268 | && DECL_P (gimple_assign_rhs1 (stmt)) | |
269 | && (cst = get_symbol_constant_value (gimple_assign_rhs1 (stmt)))) | |
88dbf20f | 270 | { |
8edeb88b | 271 | val.lattice_val = CONSTANT; |
272 | val.value = cst; | |
88dbf20f | 273 | } |
274 | else | |
8edeb88b | 275 | /* Any other variable defined by an assignment or a PHI node |
276 | is considered UNDEFINED. */ | |
277 | val.lattice_val = UNDEFINED; | |
278 | } | |
279 | else | |
280 | { | |
281 | /* Otherwise, VAR will never take on a constant value. */ | |
282 | val.lattice_val = VARYING; | |
b7e55469 | 283 | val.mask = double_int_minus_one; |
41511585 | 284 | } |
4ee9c684 | 285 | |
41511585 | 286 | return val; |
287 | } | |
4ee9c684 | 288 | |
4ee9c684 | 289 | |
bfa30570 | 290 | /* Get the constant value associated with variable VAR. */ |
4ee9c684 | 291 | |
bfa30570 | 292 | static inline prop_value_t * |
293 | get_value (tree var) | |
88dbf20f | 294 | { |
e004838d | 295 | prop_value_t *val; |
bfa30570 | 296 | |
e004838d | 297 | if (const_val == NULL) |
298 | return NULL; | |
299 | ||
300 | val = &const_val[SSA_NAME_VERSION (var)]; | |
bfa30570 | 301 | if (val->lattice_val == UNINITIALIZED) |
4ee9c684 | 302 | *val = get_default_value (var); |
303 | ||
4af351a8 | 304 | canonicalize_float_value (val); |
305 | ||
4ee9c684 | 306 | return val; |
307 | } | |
308 | ||
15d138c9 | 309 | /* Return the constant tree value associated with VAR. */ |
310 | ||
311 | static inline tree | |
312 | get_constant_value (tree var) | |
313 | { | |
98d92e3c | 314 | prop_value_t *val; |
315 | if (TREE_CODE (var) != SSA_NAME) | |
316 | { | |
317 | if (is_gimple_min_invariant (var)) | |
318 | return var; | |
319 | return NULL_TREE; | |
320 | } | |
321 | val = get_value (var); | |
b7e55469 | 322 | if (val |
323 | && val->lattice_val == CONSTANT | |
324 | && (TREE_CODE (val->value) != INTEGER_CST | |
cf8f0e63 | 325 | || val->mask.is_zero ())) |
15d138c9 | 326 | return val->value; |
327 | return NULL_TREE; | |
328 | } | |
329 | ||
bfa30570 | 330 | /* Sets the value associated with VAR to VARYING. */ |
331 | ||
332 | static inline void | |
333 | set_value_varying (tree var) | |
334 | { | |
335 | prop_value_t *val = &const_val[SSA_NAME_VERSION (var)]; | |
336 | ||
337 | val->lattice_val = VARYING; | |
338 | val->value = NULL_TREE; | |
b7e55469 | 339 | val->mask = double_int_minus_one; |
bfa30570 | 340 | } |
4ee9c684 | 341 | |
b31eb493 | 342 | /* For float types, modify the value of VAL to make ccp work correctly |
343 | for non-standard values (-0, NaN): | |
344 | ||
345 | If HONOR_SIGNED_ZEROS is false, and VAL = -0, we canonicalize it to 0. | |
346 | If HONOR_NANS is false, and VAL is NaN, we canonicalize it to UNDEFINED. | |
347 | This is to fix the following problem (see PR 29921): Suppose we have | |
348 | ||
349 | x = 0.0 * y | |
350 | ||
351 | and we set value of y to NaN. This causes value of x to be set to NaN. | |
352 | When we later determine that y is in fact VARYING, fold uses the fact | |
353 | that HONOR_NANS is false, and we try to change the value of x to 0, | |
354 | causing an ICE. With HONOR_NANS being false, the real appearance of | |
355 | NaN would cause undefined behavior, though, so claiming that y (and x) | |
356 | are UNDEFINED initially is correct. */ | |
357 | ||
358 | static void | |
359 | canonicalize_float_value (prop_value_t *val) | |
360 | { | |
361 | enum machine_mode mode; | |
362 | tree type; | |
363 | REAL_VALUE_TYPE d; | |
364 | ||
365 | if (val->lattice_val != CONSTANT | |
366 | || TREE_CODE (val->value) != REAL_CST) | |
367 | return; | |
368 | ||
369 | d = TREE_REAL_CST (val->value); | |
370 | type = TREE_TYPE (val->value); | |
371 | mode = TYPE_MODE (type); | |
372 | ||
373 | if (!HONOR_SIGNED_ZEROS (mode) | |
374 | && REAL_VALUE_MINUS_ZERO (d)) | |
375 | { | |
376 | val->value = build_real (type, dconst0); | |
377 | return; | |
378 | } | |
379 | ||
380 | if (!HONOR_NANS (mode) | |
381 | && REAL_VALUE_ISNAN (d)) | |
382 | { | |
383 | val->lattice_val = UNDEFINED; | |
384 | val->value = NULL; | |
b31eb493 | 385 | return; |
386 | } | |
387 | } | |
388 | ||
b7e55469 | 389 | /* Return whether the lattice transition is valid. */ |
390 | ||
391 | static bool | |
392 | valid_lattice_transition (prop_value_t old_val, prop_value_t new_val) | |
393 | { | |
394 | /* Lattice transitions must always be monotonically increasing in | |
395 | value. */ | |
396 | if (old_val.lattice_val < new_val.lattice_val) | |
397 | return true; | |
398 | ||
399 | if (old_val.lattice_val != new_val.lattice_val) | |
400 | return false; | |
401 | ||
402 | if (!old_val.value && !new_val.value) | |
403 | return true; | |
404 | ||
405 | /* Now both lattice values are CONSTANT. */ | |
406 | ||
43c92e0a | 407 | /* Allow transitioning from PHI <&x, not executable> == &x |
408 | to PHI <&x, &y> == common alignment. */ | |
b7e55469 | 409 | if (TREE_CODE (old_val.value) != INTEGER_CST |
410 | && TREE_CODE (new_val.value) == INTEGER_CST) | |
411 | return true; | |
412 | ||
413 | /* Bit-lattices have to agree in the still valid bits. */ | |
414 | if (TREE_CODE (old_val.value) == INTEGER_CST | |
415 | && TREE_CODE (new_val.value) == INTEGER_CST) | |
cf8f0e63 | 416 | return tree_to_double_int (old_val.value).and_not (new_val.mask) |
417 | == tree_to_double_int (new_val.value).and_not (new_val.mask); | |
b7e55469 | 418 | |
419 | /* Otherwise constant values have to agree. */ | |
420 | return operand_equal_p (old_val.value, new_val.value, 0); | |
421 | } | |
422 | ||
88dbf20f | 423 | /* Set the value for variable VAR to NEW_VAL. Return true if the new |
424 | value is different from VAR's previous value. */ | |
4ee9c684 | 425 | |
41511585 | 426 | static bool |
88dbf20f | 427 | set_lattice_value (tree var, prop_value_t new_val) |
4ee9c684 | 428 | { |
6d0bf6d6 | 429 | /* We can deal with old UNINITIALIZED values just fine here. */ |
430 | prop_value_t *old_val = &const_val[SSA_NAME_VERSION (var)]; | |
88dbf20f | 431 | |
b31eb493 | 432 | canonicalize_float_value (&new_val); |
433 | ||
b7e55469 | 434 | /* We have to be careful to not go up the bitwise lattice |
435 | represented by the mask. | |
436 | ??? This doesn't seem to be the best place to enforce this. */ | |
437 | if (new_val.lattice_val == CONSTANT | |
438 | && old_val->lattice_val == CONSTANT | |
439 | && TREE_CODE (new_val.value) == INTEGER_CST | |
440 | && TREE_CODE (old_val->value) == INTEGER_CST) | |
441 | { | |
442 | double_int diff; | |
cf8f0e63 | 443 | diff = tree_to_double_int (new_val.value) |
444 | ^ tree_to_double_int (old_val->value); | |
445 | new_val.mask = new_val.mask | old_val->mask | diff; | |
b7e55469 | 446 | } |
bfa30570 | 447 | |
b7e55469 | 448 | gcc_assert (valid_lattice_transition (*old_val, new_val)); |
88dbf20f | 449 | |
b7e55469 | 450 | /* If *OLD_VAL and NEW_VAL are the same, return false to inform the |
451 | caller that this was a non-transition. */ | |
452 | if (old_val->lattice_val != new_val.lattice_val | |
453 | || (new_val.lattice_val == CONSTANT | |
454 | && TREE_CODE (new_val.value) == INTEGER_CST | |
455 | && (TREE_CODE (old_val->value) != INTEGER_CST | |
cf8f0e63 | 456 | || new_val.mask != old_val->mask))) |
4ee9c684 | 457 | { |
b7e55469 | 458 | /* ??? We would like to delay creation of INTEGER_CSTs from |
459 | partially constants here. */ | |
460 | ||
41511585 | 461 | if (dump_file && (dump_flags & TDF_DETAILS)) |
462 | { | |
88dbf20f | 463 | dump_lattice_value (dump_file, "Lattice value changed to ", new_val); |
bfa30570 | 464 | fprintf (dump_file, ". Adding SSA edges to worklist.\n"); |
41511585 | 465 | } |
466 | ||
88dbf20f | 467 | *old_val = new_val; |
468 | ||
6d0bf6d6 | 469 | gcc_assert (new_val.lattice_val != UNINITIALIZED); |
bfa30570 | 470 | return true; |
4ee9c684 | 471 | } |
41511585 | 472 | |
473 | return false; | |
4ee9c684 | 474 | } |
475 | ||
b7e55469 | 476 | static prop_value_t get_value_for_expr (tree, bool); |
477 | static prop_value_t bit_value_binop (enum tree_code, tree, tree, tree); | |
478 | static void bit_value_binop_1 (enum tree_code, tree, double_int *, double_int *, | |
479 | tree, double_int, double_int, | |
480 | tree, double_int, double_int); | |
481 | ||
482 | /* Return a double_int that can be used for bitwise simplifications | |
483 | from VAL. */ | |
484 | ||
485 | static double_int | |
486 | value_to_double_int (prop_value_t val) | |
487 | { | |
488 | if (val.value | |
489 | && TREE_CODE (val.value) == INTEGER_CST) | |
490 | return tree_to_double_int (val.value); | |
491 | else | |
492 | return double_int_zero; | |
493 | } | |
494 | ||
495 | /* Return the value for the address expression EXPR based on alignment | |
496 | information. */ | |
6d0bf6d6 | 497 | |
498 | static prop_value_t | |
b7e55469 | 499 | get_value_from_alignment (tree expr) |
500 | { | |
f8abb542 | 501 | tree type = TREE_TYPE (expr); |
b7e55469 | 502 | prop_value_t val; |
f8abb542 | 503 | unsigned HOST_WIDE_INT bitpos; |
504 | unsigned int align; | |
b7e55469 | 505 | |
506 | gcc_assert (TREE_CODE (expr) == ADDR_EXPR); | |
507 | ||
59da1bcd | 508 | get_pointer_alignment_1 (expr, &align, &bitpos); |
cf8f0e63 | 509 | val.mask = (POINTER_TYPE_P (type) || TYPE_UNSIGNED (type) |
510 | ? double_int::mask (TYPE_PRECISION (type)) | |
511 | : double_int_minus_one) | |
512 | .and_not (double_int::from_uhwi (align / BITS_PER_UNIT - 1)); | |
513 | val.lattice_val = val.mask.is_minus_one () ? VARYING : CONSTANT; | |
f8abb542 | 514 | if (val.lattice_val == CONSTANT) |
515 | val.value | |
cf8f0e63 | 516 | = double_int_to_tree (type, |
517 | double_int::from_uhwi (bitpos / BITS_PER_UNIT)); | |
b7e55469 | 518 | else |
f8abb542 | 519 | val.value = NULL_TREE; |
b7e55469 | 520 | |
521 | return val; | |
522 | } | |
523 | ||
524 | /* Return the value for the tree operand EXPR. If FOR_BITS_P is true | |
525 | return constant bits extracted from alignment information for | |
526 | invariant addresses. */ | |
527 | ||
528 | static prop_value_t | |
529 | get_value_for_expr (tree expr, bool for_bits_p) | |
6d0bf6d6 | 530 | { |
531 | prop_value_t val; | |
532 | ||
533 | if (TREE_CODE (expr) == SSA_NAME) | |
b7e55469 | 534 | { |
535 | val = *get_value (expr); | |
536 | if (for_bits_p | |
537 | && val.lattice_val == CONSTANT | |
538 | && TREE_CODE (val.value) == ADDR_EXPR) | |
539 | val = get_value_from_alignment (val.value); | |
540 | } | |
541 | else if (is_gimple_min_invariant (expr) | |
542 | && (!for_bits_p || TREE_CODE (expr) != ADDR_EXPR)) | |
6d0bf6d6 | 543 | { |
544 | val.lattice_val = CONSTANT; | |
545 | val.value = expr; | |
b7e55469 | 546 | val.mask = double_int_zero; |
6d0bf6d6 | 547 | canonicalize_float_value (&val); |
548 | } | |
b7e55469 | 549 | else if (TREE_CODE (expr) == ADDR_EXPR) |
550 | val = get_value_from_alignment (expr); | |
6d0bf6d6 | 551 | else |
552 | { | |
553 | val.lattice_val = VARYING; | |
b7e55469 | 554 | val.mask = double_int_minus_one; |
6d0bf6d6 | 555 | val.value = NULL_TREE; |
556 | } | |
6d0bf6d6 | 557 | return val; |
558 | } | |
559 | ||
88dbf20f | 560 | /* Return the likely CCP lattice value for STMT. |
4ee9c684 | 561 | |
41511585 | 562 | If STMT has no operands, then return CONSTANT. |
4ee9c684 | 563 | |
d61b9af3 | 564 | Else if undefinedness of operands of STMT cause its value to be |
565 | undefined, then return UNDEFINED. | |
4ee9c684 | 566 | |
41511585 | 567 | Else if any operands of STMT are constants, then return CONSTANT. |
4ee9c684 | 568 | |
41511585 | 569 | Else return VARYING. */ |
4ee9c684 | 570 | |
88dbf20f | 571 | static ccp_lattice_t |
75a70cf9 | 572 | likely_value (gimple stmt) |
41511585 | 573 | { |
d61b9af3 | 574 | bool has_constant_operand, has_undefined_operand, all_undefined_operands; |
41511585 | 575 | tree use; |
576 | ssa_op_iter iter; | |
8edeb88b | 577 | unsigned i; |
4ee9c684 | 578 | |
590c3166 | 579 | enum gimple_code code = gimple_code (stmt); |
75a70cf9 | 580 | |
581 | /* This function appears to be called only for assignments, calls, | |
582 | conditionals, and switches, due to the logic in visit_stmt. */ | |
583 | gcc_assert (code == GIMPLE_ASSIGN | |
584 | || code == GIMPLE_CALL | |
585 | || code == GIMPLE_COND | |
586 | || code == GIMPLE_SWITCH); | |
88dbf20f | 587 | |
588 | /* If the statement has volatile operands, it won't fold to a | |
589 | constant value. */ | |
75a70cf9 | 590 | if (gimple_has_volatile_ops (stmt)) |
88dbf20f | 591 | return VARYING; |
592 | ||
75a70cf9 | 593 | /* Arrive here for more complex cases. */ |
bfa30570 | 594 | has_constant_operand = false; |
d61b9af3 | 595 | has_undefined_operand = false; |
596 | all_undefined_operands = true; | |
8edeb88b | 597 | FOR_EACH_SSA_TREE_OPERAND (use, stmt, iter, SSA_OP_USE) |
41511585 | 598 | { |
bfa30570 | 599 | prop_value_t *val = get_value (use); |
41511585 | 600 | |
bfa30570 | 601 | if (val->lattice_val == UNDEFINED) |
d61b9af3 | 602 | has_undefined_operand = true; |
603 | else | |
604 | all_undefined_operands = false; | |
88dbf20f | 605 | |
41511585 | 606 | if (val->lattice_val == CONSTANT) |
bfa30570 | 607 | has_constant_operand = true; |
4ee9c684 | 608 | } |
41511585 | 609 | |
dd277d48 | 610 | /* There may be constants in regular rhs operands. For calls we |
611 | have to ignore lhs, fndecl and static chain, otherwise only | |
612 | the lhs. */ | |
613 | for (i = (is_gimple_call (stmt) ? 2 : 0) + gimple_has_lhs (stmt); | |
8edeb88b | 614 | i < gimple_num_ops (stmt); ++i) |
615 | { | |
616 | tree op = gimple_op (stmt, i); | |
617 | if (!op || TREE_CODE (op) == SSA_NAME) | |
618 | continue; | |
619 | if (is_gimple_min_invariant (op)) | |
620 | has_constant_operand = true; | |
621 | } | |
622 | ||
87c0a9fc | 623 | if (has_constant_operand) |
624 | all_undefined_operands = false; | |
625 | ||
d61b9af3 | 626 | /* If the operation combines operands like COMPLEX_EXPR make sure to |
627 | not mark the result UNDEFINED if only one part of the result is | |
628 | undefined. */ | |
75a70cf9 | 629 | if (has_undefined_operand && all_undefined_operands) |
d61b9af3 | 630 | return UNDEFINED; |
75a70cf9 | 631 | else if (code == GIMPLE_ASSIGN && has_undefined_operand) |
d61b9af3 | 632 | { |
75a70cf9 | 633 | switch (gimple_assign_rhs_code (stmt)) |
d61b9af3 | 634 | { |
635 | /* Unary operators are handled with all_undefined_operands. */ | |
636 | case PLUS_EXPR: | |
637 | case MINUS_EXPR: | |
d61b9af3 | 638 | case POINTER_PLUS_EXPR: |
d61b9af3 | 639 | /* Not MIN_EXPR, MAX_EXPR. One VARYING operand may be selected. |
640 | Not bitwise operators, one VARYING operand may specify the | |
641 | result completely. Not logical operators for the same reason. | |
05a936a0 | 642 | Not COMPLEX_EXPR as one VARYING operand makes the result partly |
643 | not UNDEFINED. Not *DIV_EXPR, comparisons and shifts because | |
644 | the undefined operand may be promoted. */ | |
d61b9af3 | 645 | return UNDEFINED; |
646 | ||
43c92e0a | 647 | case ADDR_EXPR: |
648 | /* If any part of an address is UNDEFINED, like the index | |
649 | of an ARRAY_EXPR, then treat the result as UNDEFINED. */ | |
650 | return UNDEFINED; | |
651 | ||
d61b9af3 | 652 | default: |
653 | ; | |
654 | } | |
655 | } | |
656 | /* If there was an UNDEFINED operand but the result may be not UNDEFINED | |
c91fedc5 | 657 | fall back to CONSTANT. During iteration UNDEFINED may still drop |
658 | to CONSTANT. */ | |
d61b9af3 | 659 | if (has_undefined_operand) |
c91fedc5 | 660 | return CONSTANT; |
d61b9af3 | 661 | |
8edeb88b | 662 | /* We do not consider virtual operands here -- load from read-only |
663 | memory may have only VARYING virtual operands, but still be | |
664 | constant. */ | |
bfa30570 | 665 | if (has_constant_operand |
8edeb88b | 666 | || gimple_references_memory_p (stmt)) |
88dbf20f | 667 | return CONSTANT; |
668 | ||
bfa30570 | 669 | return VARYING; |
4ee9c684 | 670 | } |
671 | ||
bfa30570 | 672 | /* Returns true if STMT cannot be constant. */ |
673 | ||
674 | static bool | |
75a70cf9 | 675 | surely_varying_stmt_p (gimple stmt) |
bfa30570 | 676 | { |
677 | /* If the statement has operands that we cannot handle, it cannot be | |
678 | constant. */ | |
75a70cf9 | 679 | if (gimple_has_volatile_ops (stmt)) |
bfa30570 | 680 | return true; |
681 | ||
f257af64 | 682 | /* If it is a call and does not return a value or is not a |
683 | builtin and not an indirect call, it is varying. */ | |
75a70cf9 | 684 | if (is_gimple_call (stmt)) |
f257af64 | 685 | { |
686 | tree fndecl; | |
687 | if (!gimple_call_lhs (stmt) | |
688 | || ((fndecl = gimple_call_fndecl (stmt)) != NULL_TREE | |
5768aeb3 | 689 | && !DECL_BUILT_IN (fndecl))) |
f257af64 | 690 | return true; |
691 | } | |
bfa30570 | 692 | |
8edeb88b | 693 | /* Any other store operation is not interesting. */ |
dd277d48 | 694 | else if (gimple_vdef (stmt)) |
8edeb88b | 695 | return true; |
696 | ||
bfa30570 | 697 | /* Anything other than assignments and conditional jumps are not |
698 | interesting for CCP. */ | |
75a70cf9 | 699 | if (gimple_code (stmt) != GIMPLE_ASSIGN |
f257af64 | 700 | && gimple_code (stmt) != GIMPLE_COND |
701 | && gimple_code (stmt) != GIMPLE_SWITCH | |
702 | && gimple_code (stmt) != GIMPLE_CALL) | |
bfa30570 | 703 | return true; |
704 | ||
705 | return false; | |
706 | } | |
4ee9c684 | 707 | |
41511585 | 708 | /* Initialize local data structures for CCP. */ |
4ee9c684 | 709 | |
710 | static void | |
41511585 | 711 | ccp_initialize (void) |
4ee9c684 | 712 | { |
41511585 | 713 | basic_block bb; |
4ee9c684 | 714 | |
43959b95 | 715 | const_val = XCNEWVEC (prop_value_t, num_ssa_names); |
4ee9c684 | 716 | |
41511585 | 717 | /* Initialize simulation flags for PHI nodes and statements. */ |
718 | FOR_EACH_BB (bb) | |
4ee9c684 | 719 | { |
75a70cf9 | 720 | gimple_stmt_iterator i; |
4ee9c684 | 721 | |
75a70cf9 | 722 | for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i)) |
41511585 | 723 | { |
75a70cf9 | 724 | gimple stmt = gsi_stmt (i); |
2193544e | 725 | bool is_varying; |
726 | ||
727 | /* If the statement is a control insn, then we do not | |
728 | want to avoid simulating the statement once. Failure | |
729 | to do so means that those edges will never get added. */ | |
730 | if (stmt_ends_bb_p (stmt)) | |
731 | is_varying = false; | |
732 | else | |
733 | is_varying = surely_varying_stmt_p (stmt); | |
4ee9c684 | 734 | |
bfa30570 | 735 | if (is_varying) |
41511585 | 736 | { |
88dbf20f | 737 | tree def; |
738 | ssa_op_iter iter; | |
739 | ||
740 | /* If the statement will not produce a constant, mark | |
741 | all its outputs VARYING. */ | |
742 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS) | |
8edeb88b | 743 | set_value_varying (def); |
41511585 | 744 | } |
75a70cf9 | 745 | prop_set_simulate_again (stmt, !is_varying); |
41511585 | 746 | } |
4ee9c684 | 747 | } |
748 | ||
75a70cf9 | 749 | /* Now process PHI nodes. We never clear the simulate_again flag on |
750 | phi nodes, since we do not know which edges are executable yet, | |
751 | except for phi nodes for virtual operands when we do not do store ccp. */ | |
41511585 | 752 | FOR_EACH_BB (bb) |
4ee9c684 | 753 | { |
75a70cf9 | 754 | gimple_stmt_iterator i; |
41511585 | 755 | |
75a70cf9 | 756 | for (i = gsi_start_phis (bb); !gsi_end_p (i); gsi_next (&i)) |
757 | { | |
758 | gimple phi = gsi_stmt (i); | |
759 | ||
7c782c9b | 760 | if (virtual_operand_p (gimple_phi_result (phi))) |
75a70cf9 | 761 | prop_set_simulate_again (phi, false); |
bfa30570 | 762 | else |
75a70cf9 | 763 | prop_set_simulate_again (phi, true); |
41511585 | 764 | } |
4ee9c684 | 765 | } |
41511585 | 766 | } |
4ee9c684 | 767 | |
43fb76c1 | 768 | /* Debug count support. Reset the values of ssa names |
769 | VARYING when the total number ssa names analyzed is | |
770 | beyond the debug count specified. */ | |
771 | ||
772 | static void | |
773 | do_dbg_cnt (void) | |
774 | { | |
775 | unsigned i; | |
776 | for (i = 0; i < num_ssa_names; i++) | |
777 | { | |
778 | if (!dbg_cnt (ccp)) | |
779 | { | |
780 | const_val[i].lattice_val = VARYING; | |
b7e55469 | 781 | const_val[i].mask = double_int_minus_one; |
43fb76c1 | 782 | const_val[i].value = NULL_TREE; |
783 | } | |
784 | } | |
785 | } | |
786 | ||
4ee9c684 | 787 | |
88dbf20f | 788 | /* Do final substitution of propagated values, cleanup the flowgraph and |
48e1416a | 789 | free allocated storage. |
4ee9c684 | 790 | |
33a34f1e | 791 | Return TRUE when something was optimized. */ |
792 | ||
793 | static bool | |
88dbf20f | 794 | ccp_finalize (void) |
4ee9c684 | 795 | { |
43fb76c1 | 796 | bool something_changed; |
153c3b50 | 797 | unsigned i; |
43fb76c1 | 798 | |
799 | do_dbg_cnt (); | |
153c3b50 | 800 | |
801 | /* Derive alignment and misalignment information from partially | |
802 | constant pointers in the lattice. */ | |
803 | for (i = 1; i < num_ssa_names; ++i) | |
804 | { | |
805 | tree name = ssa_name (i); | |
806 | prop_value_t *val; | |
153c3b50 | 807 | unsigned int tem, align; |
808 | ||
809 | if (!name | |
810 | || !POINTER_TYPE_P (TREE_TYPE (name))) | |
811 | continue; | |
812 | ||
813 | val = get_value (name); | |
814 | if (val->lattice_val != CONSTANT | |
815 | || TREE_CODE (val->value) != INTEGER_CST) | |
816 | continue; | |
817 | ||
818 | /* Trailing constant bits specify the alignment, trailing value | |
819 | bits the misalignment. */ | |
820 | tem = val->mask.low; | |
821 | align = (tem & -tem); | |
ceea063b | 822 | if (align > 1) |
823 | set_ptr_info_alignment (get_ptr_info (name), align, | |
824 | TREE_INT_CST_LOW (val->value) & (align - 1)); | |
153c3b50 | 825 | } |
826 | ||
88dbf20f | 827 | /* Perform substitutions based on the known constant values. */ |
14f101cf | 828 | something_changed = substitute_and_fold (get_constant_value, |
829 | ccp_fold_stmt, true); | |
4ee9c684 | 830 | |
88dbf20f | 831 | free (const_val); |
e004838d | 832 | const_val = NULL; |
33a34f1e | 833 | return something_changed;; |
4ee9c684 | 834 | } |
835 | ||
836 | ||
88dbf20f | 837 | /* Compute the meet operator between *VAL1 and *VAL2. Store the result |
838 | in VAL1. | |
839 | ||
840 | any M UNDEFINED = any | |
88dbf20f | 841 | any M VARYING = VARYING |
842 | Ci M Cj = Ci if (i == j) | |
843 | Ci M Cj = VARYING if (i != j) | |
bfa30570 | 844 | */ |
4ee9c684 | 845 | |
846 | static void | |
88dbf20f | 847 | ccp_lattice_meet (prop_value_t *val1, prop_value_t *val2) |
4ee9c684 | 848 | { |
88dbf20f | 849 | if (val1->lattice_val == UNDEFINED) |
4ee9c684 | 850 | { |
88dbf20f | 851 | /* UNDEFINED M any = any */ |
852 | *val1 = *val2; | |
41511585 | 853 | } |
88dbf20f | 854 | else if (val2->lattice_val == UNDEFINED) |
92481a4d | 855 | { |
88dbf20f | 856 | /* any M UNDEFINED = any |
857 | Nothing to do. VAL1 already contains the value we want. */ | |
858 | ; | |
92481a4d | 859 | } |
88dbf20f | 860 | else if (val1->lattice_val == VARYING |
861 | || val2->lattice_val == VARYING) | |
41511585 | 862 | { |
88dbf20f | 863 | /* any M VARYING = VARYING. */ |
864 | val1->lattice_val = VARYING; | |
b7e55469 | 865 | val1->mask = double_int_minus_one; |
88dbf20f | 866 | val1->value = NULL_TREE; |
41511585 | 867 | } |
b7e55469 | 868 | else if (val1->lattice_val == CONSTANT |
869 | && val2->lattice_val == CONSTANT | |
870 | && TREE_CODE (val1->value) == INTEGER_CST | |
871 | && TREE_CODE (val2->value) == INTEGER_CST) | |
872 | { | |
873 | /* Ci M Cj = Ci if (i == j) | |
874 | Ci M Cj = VARYING if (i != j) | |
875 | ||
876 | For INTEGER_CSTs mask unequal bits. If no equal bits remain, | |
877 | drop to varying. */ | |
cf8f0e63 | 878 | val1->mask = val1->mask | val2->mask |
879 | | (tree_to_double_int (val1->value) | |
880 | ^ tree_to_double_int (val2->value)); | |
881 | if (val1->mask.is_minus_one ()) | |
b7e55469 | 882 | { |
883 | val1->lattice_val = VARYING; | |
884 | val1->value = NULL_TREE; | |
885 | } | |
886 | } | |
88dbf20f | 887 | else if (val1->lattice_val == CONSTANT |
888 | && val2->lattice_val == CONSTANT | |
61207d43 | 889 | && simple_cst_equal (val1->value, val2->value) == 1) |
41511585 | 890 | { |
88dbf20f | 891 | /* Ci M Cj = Ci if (i == j) |
892 | Ci M Cj = VARYING if (i != j) | |
893 | ||
b7e55469 | 894 | VAL1 already contains the value we want for equivalent values. */ |
895 | } | |
896 | else if (val1->lattice_val == CONSTANT | |
897 | && val2->lattice_val == CONSTANT | |
898 | && (TREE_CODE (val1->value) == ADDR_EXPR | |
899 | || TREE_CODE (val2->value) == ADDR_EXPR)) | |
900 | { | |
901 | /* When not equal addresses are involved try meeting for | |
902 | alignment. */ | |
903 | prop_value_t tem = *val2; | |
904 | if (TREE_CODE (val1->value) == ADDR_EXPR) | |
905 | *val1 = get_value_for_expr (val1->value, true); | |
906 | if (TREE_CODE (val2->value) == ADDR_EXPR) | |
907 | tem = get_value_for_expr (val2->value, true); | |
908 | ccp_lattice_meet (val1, &tem); | |
41511585 | 909 | } |
910 | else | |
911 | { | |
88dbf20f | 912 | /* Any other combination is VARYING. */ |
913 | val1->lattice_val = VARYING; | |
b7e55469 | 914 | val1->mask = double_int_minus_one; |
88dbf20f | 915 | val1->value = NULL_TREE; |
41511585 | 916 | } |
4ee9c684 | 917 | } |
918 | ||
919 | ||
41511585 | 920 | /* Loop through the PHI_NODE's parameters for BLOCK and compare their |
921 | lattice values to determine PHI_NODE's lattice value. The value of a | |
88dbf20f | 922 | PHI node is determined calling ccp_lattice_meet with all the arguments |
41511585 | 923 | of the PHI node that are incoming via executable edges. */ |
4ee9c684 | 924 | |
41511585 | 925 | static enum ssa_prop_result |
75a70cf9 | 926 | ccp_visit_phi_node (gimple phi) |
4ee9c684 | 927 | { |
75a70cf9 | 928 | unsigned i; |
88dbf20f | 929 | prop_value_t *old_val, new_val; |
4ee9c684 | 930 | |
41511585 | 931 | if (dump_file && (dump_flags & TDF_DETAILS)) |
4ee9c684 | 932 | { |
41511585 | 933 | fprintf (dump_file, "\nVisiting PHI node: "); |
75a70cf9 | 934 | print_gimple_stmt (dump_file, phi, 0, dump_flags); |
4ee9c684 | 935 | } |
4ee9c684 | 936 | |
75a70cf9 | 937 | old_val = get_value (gimple_phi_result (phi)); |
41511585 | 938 | switch (old_val->lattice_val) |
939 | { | |
940 | case VARYING: | |
88dbf20f | 941 | return SSA_PROP_VARYING; |
4ee9c684 | 942 | |
41511585 | 943 | case CONSTANT: |
944 | new_val = *old_val; | |
945 | break; | |
4ee9c684 | 946 | |
41511585 | 947 | case UNDEFINED: |
41511585 | 948 | new_val.lattice_val = UNDEFINED; |
88dbf20f | 949 | new_val.value = NULL_TREE; |
41511585 | 950 | break; |
4ee9c684 | 951 | |
41511585 | 952 | default: |
8c0963c4 | 953 | gcc_unreachable (); |
41511585 | 954 | } |
4ee9c684 | 955 | |
75a70cf9 | 956 | for (i = 0; i < gimple_phi_num_args (phi); i++) |
41511585 | 957 | { |
88dbf20f | 958 | /* Compute the meet operator over all the PHI arguments flowing |
959 | through executable edges. */ | |
75a70cf9 | 960 | edge e = gimple_phi_arg_edge (phi, i); |
4ee9c684 | 961 | |
41511585 | 962 | if (dump_file && (dump_flags & TDF_DETAILS)) |
963 | { | |
964 | fprintf (dump_file, | |
965 | "\n Argument #%d (%d -> %d %sexecutable)\n", | |
966 | i, e->src->index, e->dest->index, | |
967 | (e->flags & EDGE_EXECUTABLE) ? "" : "not "); | |
968 | } | |
969 | ||
970 | /* If the incoming edge is executable, Compute the meet operator for | |
971 | the existing value of the PHI node and the current PHI argument. */ | |
972 | if (e->flags & EDGE_EXECUTABLE) | |
973 | { | |
75a70cf9 | 974 | tree arg = gimple_phi_arg (phi, i)->def; |
b7e55469 | 975 | prop_value_t arg_val = get_value_for_expr (arg, false); |
4ee9c684 | 976 | |
88dbf20f | 977 | ccp_lattice_meet (&new_val, &arg_val); |
4ee9c684 | 978 | |
41511585 | 979 | if (dump_file && (dump_flags & TDF_DETAILS)) |
980 | { | |
981 | fprintf (dump_file, "\t"); | |
88dbf20f | 982 | print_generic_expr (dump_file, arg, dump_flags); |
983 | dump_lattice_value (dump_file, "\tValue: ", arg_val); | |
41511585 | 984 | fprintf (dump_file, "\n"); |
985 | } | |
4ee9c684 | 986 | |
41511585 | 987 | if (new_val.lattice_val == VARYING) |
988 | break; | |
989 | } | |
990 | } | |
4ee9c684 | 991 | |
992 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
41511585 | 993 | { |
994 | dump_lattice_value (dump_file, "\n PHI node value: ", new_val); | |
995 | fprintf (dump_file, "\n\n"); | |
996 | } | |
997 | ||
bfa30570 | 998 | /* Make the transition to the new value. */ |
75a70cf9 | 999 | if (set_lattice_value (gimple_phi_result (phi), new_val)) |
41511585 | 1000 | { |
1001 | if (new_val.lattice_val == VARYING) | |
1002 | return SSA_PROP_VARYING; | |
1003 | else | |
1004 | return SSA_PROP_INTERESTING; | |
1005 | } | |
1006 | else | |
1007 | return SSA_PROP_NOT_INTERESTING; | |
4ee9c684 | 1008 | } |
1009 | ||
15d138c9 | 1010 | /* Return the constant value for OP or OP otherwise. */ |
00f4f705 | 1011 | |
1012 | static tree | |
15d138c9 | 1013 | valueize_op (tree op) |
00f4f705 | 1014 | { |
00f4f705 | 1015 | if (TREE_CODE (op) == SSA_NAME) |
1016 | { | |
15d138c9 | 1017 | tree tem = get_constant_value (op); |
1018 | if (tem) | |
1019 | return tem; | |
00f4f705 | 1020 | } |
1021 | return op; | |
1022 | } | |
1023 | ||
41511585 | 1024 | /* CCP specific front-end to the non-destructive constant folding |
1025 | routines. | |
4ee9c684 | 1026 | |
1027 | Attempt to simplify the RHS of STMT knowing that one or more | |
1028 | operands are constants. | |
1029 | ||
1030 | If simplification is possible, return the simplified RHS, | |
75a70cf9 | 1031 | otherwise return the original RHS or NULL_TREE. */ |
4ee9c684 | 1032 | |
1033 | static tree | |
75a70cf9 | 1034 | ccp_fold (gimple stmt) |
4ee9c684 | 1035 | { |
389dd41b | 1036 | location_t loc = gimple_location (stmt); |
75a70cf9 | 1037 | switch (gimple_code (stmt)) |
88dbf20f | 1038 | { |
75a70cf9 | 1039 | case GIMPLE_COND: |
1040 | { | |
1041 | /* Handle comparison operators that can appear in GIMPLE form. */ | |
15d138c9 | 1042 | tree op0 = valueize_op (gimple_cond_lhs (stmt)); |
1043 | tree op1 = valueize_op (gimple_cond_rhs (stmt)); | |
75a70cf9 | 1044 | enum tree_code code = gimple_cond_code (stmt); |
389dd41b | 1045 | return fold_binary_loc (loc, code, boolean_type_node, op0, op1); |
75a70cf9 | 1046 | } |
4ee9c684 | 1047 | |
75a70cf9 | 1048 | case GIMPLE_SWITCH: |
1049 | { | |
15d138c9 | 1050 | /* Return the constant switch index. */ |
1051 | return valueize_op (gimple_switch_index (stmt)); | |
75a70cf9 | 1052 | } |
912f109f | 1053 | |
1d0b727d | 1054 | case GIMPLE_ASSIGN: |
1055 | case GIMPLE_CALL: | |
1056 | return gimple_fold_stmt_to_constant_1 (stmt, valueize_op); | |
04236c3a | 1057 | |
8782adcf | 1058 | default: |
1d0b727d | 1059 | gcc_unreachable (); |
8782adcf | 1060 | } |
8782adcf | 1061 | } |
75a70cf9 | 1062 | |
b7e55469 | 1063 | /* Apply the operation CODE in type TYPE to the value, mask pair |
1064 | RVAL and RMASK representing a value of type RTYPE and set | |
1065 | the value, mask pair *VAL and *MASK to the result. */ | |
1066 | ||
1067 | static void | |
1068 | bit_value_unop_1 (enum tree_code code, tree type, | |
1069 | double_int *val, double_int *mask, | |
1070 | tree rtype, double_int rval, double_int rmask) | |
1071 | { | |
1072 | switch (code) | |
1073 | { | |
1074 | case BIT_NOT_EXPR: | |
1075 | *mask = rmask; | |
cf8f0e63 | 1076 | *val = ~rval; |
b7e55469 | 1077 | break; |
1078 | ||
1079 | case NEGATE_EXPR: | |
1080 | { | |
1081 | double_int temv, temm; | |
1082 | /* Return ~rval + 1. */ | |
1083 | bit_value_unop_1 (BIT_NOT_EXPR, type, &temv, &temm, type, rval, rmask); | |
1084 | bit_value_binop_1 (PLUS_EXPR, type, val, mask, | |
1085 | type, temv, temm, | |
1086 | type, double_int_one, double_int_zero); | |
1087 | break; | |
1088 | } | |
1089 | ||
1090 | CASE_CONVERT: | |
1091 | { | |
1092 | bool uns; | |
1093 | ||
1094 | /* First extend mask and value according to the original type. */ | |
85d86b55 | 1095 | uns = TYPE_UNSIGNED (rtype); |
cf8f0e63 | 1096 | *mask = rmask.ext (TYPE_PRECISION (rtype), uns); |
1097 | *val = rval.ext (TYPE_PRECISION (rtype), uns); | |
b7e55469 | 1098 | |
1099 | /* Then extend mask and value according to the target type. */ | |
85d86b55 | 1100 | uns = TYPE_UNSIGNED (type); |
cf8f0e63 | 1101 | *mask = (*mask).ext (TYPE_PRECISION (type), uns); |
1102 | *val = (*val).ext (TYPE_PRECISION (type), uns); | |
b7e55469 | 1103 | break; |
1104 | } | |
1105 | ||
1106 | default: | |
1107 | *mask = double_int_minus_one; | |
1108 | break; | |
1109 | } | |
1110 | } | |
1111 | ||
1112 | /* Apply the operation CODE in type TYPE to the value, mask pairs | |
1113 | R1VAL, R1MASK and R2VAL, R2MASK representing a values of type R1TYPE | |
1114 | and R2TYPE and set the value, mask pair *VAL and *MASK to the result. */ | |
1115 | ||
1116 | static void | |
1117 | bit_value_binop_1 (enum tree_code code, tree type, | |
1118 | double_int *val, double_int *mask, | |
1119 | tree r1type, double_int r1val, double_int r1mask, | |
1120 | tree r2type, double_int r2val, double_int r2mask) | |
1121 | { | |
85d86b55 | 1122 | bool uns = TYPE_UNSIGNED (type); |
b7e55469 | 1123 | /* Assume we'll get a constant result. Use an initial varying value, |
1124 | we fall back to varying in the end if necessary. */ | |
1125 | *mask = double_int_minus_one; | |
1126 | switch (code) | |
1127 | { | |
1128 | case BIT_AND_EXPR: | |
1129 | /* The mask is constant where there is a known not | |
1130 | set bit, (m1 | m2) & ((v1 | m1) & (v2 | m2)) */ | |
cf8f0e63 | 1131 | *mask = (r1mask | r2mask) & (r1val | r1mask) & (r2val | r2mask); |
1132 | *val = r1val & r2val; | |
b7e55469 | 1133 | break; |
1134 | ||
1135 | case BIT_IOR_EXPR: | |
1136 | /* The mask is constant where there is a known | |
1137 | set bit, (m1 | m2) & ~((v1 & ~m1) | (v2 & ~m2)). */ | |
cf8f0e63 | 1138 | *mask = (r1mask | r2mask) |
1139 | .and_not (r1val.and_not (r1mask) | r2val.and_not (r2mask)); | |
1140 | *val = r1val | r2val; | |
b7e55469 | 1141 | break; |
1142 | ||
1143 | case BIT_XOR_EXPR: | |
1144 | /* m1 | m2 */ | |
cf8f0e63 | 1145 | *mask = r1mask | r2mask; |
1146 | *val = r1val ^ r2val; | |
b7e55469 | 1147 | break; |
1148 | ||
1149 | case LROTATE_EXPR: | |
1150 | case RROTATE_EXPR: | |
cf8f0e63 | 1151 | if (r2mask.is_zero ()) |
b7e55469 | 1152 | { |
1153 | HOST_WIDE_INT shift = r2val.low; | |
1154 | if (code == RROTATE_EXPR) | |
1155 | shift = -shift; | |
cf8f0e63 | 1156 | *mask = r1mask.lrotate (shift, TYPE_PRECISION (type)); |
1157 | *val = r1val.lrotate (shift, TYPE_PRECISION (type)); | |
b7e55469 | 1158 | } |
1159 | break; | |
1160 | ||
1161 | case LSHIFT_EXPR: | |
1162 | case RSHIFT_EXPR: | |
1163 | /* ??? We can handle partially known shift counts if we know | |
1164 | its sign. That way we can tell that (x << (y | 8)) & 255 | |
1165 | is zero. */ | |
cf8f0e63 | 1166 | if (r2mask.is_zero ()) |
b7e55469 | 1167 | { |
1168 | HOST_WIDE_INT shift = r2val.low; | |
1169 | if (code == RSHIFT_EXPR) | |
1170 | shift = -shift; | |
1171 | /* We need to know if we are doing a left or a right shift | |
1172 | to properly shift in zeros for left shift and unsigned | |
1173 | right shifts and the sign bit for signed right shifts. | |
1174 | For signed right shifts we shift in varying in case | |
1175 | the sign bit was varying. */ | |
1176 | if (shift > 0) | |
1177 | { | |
cf8f0e63 | 1178 | *mask = r1mask.llshift (shift, TYPE_PRECISION (type)); |
1179 | *val = r1val.llshift (shift, TYPE_PRECISION (type)); | |
b7e55469 | 1180 | } |
1181 | else if (shift < 0) | |
1182 | { | |
1183 | shift = -shift; | |
cf8f0e63 | 1184 | *mask = r1mask.rshift (shift, TYPE_PRECISION (type), !uns); |
1185 | *val = r1val.rshift (shift, TYPE_PRECISION (type), !uns); | |
b7e55469 | 1186 | } |
1187 | else | |
1188 | { | |
1189 | *mask = r1mask; | |
1190 | *val = r1val; | |
1191 | } | |
1192 | } | |
1193 | break; | |
1194 | ||
1195 | case PLUS_EXPR: | |
1196 | case POINTER_PLUS_EXPR: | |
1197 | { | |
1198 | double_int lo, hi; | |
1199 | /* Do the addition with unknown bits set to zero, to give carry-ins of | |
1200 | zero wherever possible. */ | |
cf8f0e63 | 1201 | lo = r1val.and_not (r1mask) + r2val.and_not (r2mask); |
1202 | lo = lo.ext (TYPE_PRECISION (type), uns); | |
b7e55469 | 1203 | /* Do the addition with unknown bits set to one, to give carry-ins of |
1204 | one wherever possible. */ | |
cf8f0e63 | 1205 | hi = (r1val | r1mask) + (r2val | r2mask); |
1206 | hi = hi.ext (TYPE_PRECISION (type), uns); | |
b7e55469 | 1207 | /* Each bit in the result is known if (a) the corresponding bits in |
1208 | both inputs are known, and (b) the carry-in to that bit position | |
1209 | is known. We can check condition (b) by seeing if we got the same | |
1210 | result with minimised carries as with maximised carries. */ | |
cf8f0e63 | 1211 | *mask = r1mask | r2mask | (lo ^ hi); |
1212 | *mask = (*mask).ext (TYPE_PRECISION (type), uns); | |
b7e55469 | 1213 | /* It shouldn't matter whether we choose lo or hi here. */ |
1214 | *val = lo; | |
1215 | break; | |
1216 | } | |
1217 | ||
1218 | case MINUS_EXPR: | |
1219 | { | |
1220 | double_int temv, temm; | |
1221 | bit_value_unop_1 (NEGATE_EXPR, r2type, &temv, &temm, | |
1222 | r2type, r2val, r2mask); | |
1223 | bit_value_binop_1 (PLUS_EXPR, type, val, mask, | |
1224 | r1type, r1val, r1mask, | |
1225 | r2type, temv, temm); | |
1226 | break; | |
1227 | } | |
1228 | ||
1229 | case MULT_EXPR: | |
1230 | { | |
1231 | /* Just track trailing zeros in both operands and transfer | |
1232 | them to the other. */ | |
cf8f0e63 | 1233 | int r1tz = (r1val | r1mask).trailing_zeros (); |
1234 | int r2tz = (r2val | r2mask).trailing_zeros (); | |
b7e55469 | 1235 | if (r1tz + r2tz >= HOST_BITS_PER_DOUBLE_INT) |
1236 | { | |
1237 | *mask = double_int_zero; | |
1238 | *val = double_int_zero; | |
1239 | } | |
1240 | else if (r1tz + r2tz > 0) | |
1241 | { | |
cf8f0e63 | 1242 | *mask = ~double_int::mask (r1tz + r2tz); |
1243 | *mask = (*mask).ext (TYPE_PRECISION (type), uns); | |
b7e55469 | 1244 | *val = double_int_zero; |
1245 | } | |
1246 | break; | |
1247 | } | |
1248 | ||
1249 | case EQ_EXPR: | |
1250 | case NE_EXPR: | |
1251 | { | |
cf8f0e63 | 1252 | double_int m = r1mask | r2mask; |
1253 | if (r1val.and_not (m) != r2val.and_not (m)) | |
b7e55469 | 1254 | { |
1255 | *mask = double_int_zero; | |
1256 | *val = ((code == EQ_EXPR) ? double_int_zero : double_int_one); | |
1257 | } | |
1258 | else | |
1259 | { | |
1260 | /* We know the result of a comparison is always one or zero. */ | |
1261 | *mask = double_int_one; | |
1262 | *val = double_int_zero; | |
1263 | } | |
1264 | break; | |
1265 | } | |
1266 | ||
1267 | case GE_EXPR: | |
1268 | case GT_EXPR: | |
1269 | { | |
1270 | double_int tem = r1val; | |
1271 | r1val = r2val; | |
1272 | r2val = tem; | |
1273 | tem = r1mask; | |
1274 | r1mask = r2mask; | |
1275 | r2mask = tem; | |
1276 | code = swap_tree_comparison (code); | |
1277 | } | |
1278 | /* Fallthru. */ | |
1279 | case LT_EXPR: | |
1280 | case LE_EXPR: | |
1281 | { | |
1282 | int minmax, maxmin; | |
1283 | /* If the most significant bits are not known we know nothing. */ | |
cf8f0e63 | 1284 | if (r1mask.is_negative () || r2mask.is_negative ()) |
b7e55469 | 1285 | break; |
1286 | ||
90c0f5b7 | 1287 | /* For comparisons the signedness is in the comparison operands. */ |
85d86b55 | 1288 | uns = TYPE_UNSIGNED (r1type); |
90c0f5b7 | 1289 | |
b7e55469 | 1290 | /* If we know the most significant bits we know the values |
1291 | value ranges by means of treating varying bits as zero | |
1292 | or one. Do a cross comparison of the max/min pairs. */ | |
cf8f0e63 | 1293 | maxmin = (r1val | r1mask).cmp (r2val.and_not (r2mask), uns); |
1294 | minmax = r1val.and_not (r1mask).cmp (r2val | r2mask, uns); | |
b7e55469 | 1295 | if (maxmin < 0) /* r1 is less than r2. */ |
1296 | { | |
1297 | *mask = double_int_zero; | |
1298 | *val = double_int_one; | |
1299 | } | |
1300 | else if (minmax > 0) /* r1 is not less or equal to r2. */ | |
1301 | { | |
1302 | *mask = double_int_zero; | |
1303 | *val = double_int_zero; | |
1304 | } | |
1305 | else if (maxmin == minmax) /* r1 and r2 are equal. */ | |
1306 | { | |
1307 | /* This probably should never happen as we'd have | |
1308 | folded the thing during fully constant value folding. */ | |
1309 | *mask = double_int_zero; | |
1310 | *val = (code == LE_EXPR ? double_int_one : double_int_zero); | |
1311 | } | |
1312 | else | |
1313 | { | |
1314 | /* We know the result of a comparison is always one or zero. */ | |
1315 | *mask = double_int_one; | |
1316 | *val = double_int_zero; | |
1317 | } | |
1318 | break; | |
1319 | } | |
1320 | ||
1321 | default:; | |
1322 | } | |
1323 | } | |
1324 | ||
1325 | /* Return the propagation value when applying the operation CODE to | |
1326 | the value RHS yielding type TYPE. */ | |
1327 | ||
1328 | static prop_value_t | |
1329 | bit_value_unop (enum tree_code code, tree type, tree rhs) | |
1330 | { | |
1331 | prop_value_t rval = get_value_for_expr (rhs, true); | |
1332 | double_int value, mask; | |
1333 | prop_value_t val; | |
c91fedc5 | 1334 | |
1335 | if (rval.lattice_val == UNDEFINED) | |
1336 | return rval; | |
1337 | ||
b7e55469 | 1338 | gcc_assert ((rval.lattice_val == CONSTANT |
1339 | && TREE_CODE (rval.value) == INTEGER_CST) | |
cf8f0e63 | 1340 | || rval.mask.is_minus_one ()); |
b7e55469 | 1341 | bit_value_unop_1 (code, type, &value, &mask, |
1342 | TREE_TYPE (rhs), value_to_double_int (rval), rval.mask); | |
cf8f0e63 | 1343 | if (!mask.is_minus_one ()) |
b7e55469 | 1344 | { |
1345 | val.lattice_val = CONSTANT; | |
1346 | val.mask = mask; | |
1347 | /* ??? Delay building trees here. */ | |
1348 | val.value = double_int_to_tree (type, value); | |
1349 | } | |
1350 | else | |
1351 | { | |
1352 | val.lattice_val = VARYING; | |
1353 | val.value = NULL_TREE; | |
1354 | val.mask = double_int_minus_one; | |
1355 | } | |
1356 | return val; | |
1357 | } | |
1358 | ||
1359 | /* Return the propagation value when applying the operation CODE to | |
1360 | the values RHS1 and RHS2 yielding type TYPE. */ | |
1361 | ||
1362 | static prop_value_t | |
1363 | bit_value_binop (enum tree_code code, tree type, tree rhs1, tree rhs2) | |
1364 | { | |
1365 | prop_value_t r1val = get_value_for_expr (rhs1, true); | |
1366 | prop_value_t r2val = get_value_for_expr (rhs2, true); | |
1367 | double_int value, mask; | |
1368 | prop_value_t val; | |
c91fedc5 | 1369 | |
1370 | if (r1val.lattice_val == UNDEFINED | |
1371 | || r2val.lattice_val == UNDEFINED) | |
1372 | { | |
1373 | val.lattice_val = VARYING; | |
1374 | val.value = NULL_TREE; | |
1375 | val.mask = double_int_minus_one; | |
1376 | return val; | |
1377 | } | |
1378 | ||
b7e55469 | 1379 | gcc_assert ((r1val.lattice_val == CONSTANT |
1380 | && TREE_CODE (r1val.value) == INTEGER_CST) | |
cf8f0e63 | 1381 | || r1val.mask.is_minus_one ()); |
b7e55469 | 1382 | gcc_assert ((r2val.lattice_val == CONSTANT |
1383 | && TREE_CODE (r2val.value) == INTEGER_CST) | |
cf8f0e63 | 1384 | || r2val.mask.is_minus_one ()); |
b7e55469 | 1385 | bit_value_binop_1 (code, type, &value, &mask, |
1386 | TREE_TYPE (rhs1), value_to_double_int (r1val), r1val.mask, | |
1387 | TREE_TYPE (rhs2), value_to_double_int (r2val), r2val.mask); | |
cf8f0e63 | 1388 | if (!mask.is_minus_one ()) |
b7e55469 | 1389 | { |
1390 | val.lattice_val = CONSTANT; | |
1391 | val.mask = mask; | |
1392 | /* ??? Delay building trees here. */ | |
1393 | val.value = double_int_to_tree (type, value); | |
1394 | } | |
1395 | else | |
1396 | { | |
1397 | val.lattice_val = VARYING; | |
1398 | val.value = NULL_TREE; | |
1399 | val.mask = double_int_minus_one; | |
1400 | } | |
1401 | return val; | |
1402 | } | |
1403 | ||
fca0886c | 1404 | /* Return the propagation value when applying __builtin_assume_aligned to |
1405 | its arguments. */ | |
1406 | ||
1407 | static prop_value_t | |
1408 | bit_value_assume_aligned (gimple stmt) | |
1409 | { | |
1410 | tree ptr = gimple_call_arg (stmt, 0), align, misalign = NULL_TREE; | |
1411 | tree type = TREE_TYPE (ptr); | |
1412 | unsigned HOST_WIDE_INT aligni, misaligni = 0; | |
1413 | prop_value_t ptrval = get_value_for_expr (ptr, true); | |
1414 | prop_value_t alignval; | |
1415 | double_int value, mask; | |
1416 | prop_value_t val; | |
1417 | if (ptrval.lattice_val == UNDEFINED) | |
1418 | return ptrval; | |
1419 | gcc_assert ((ptrval.lattice_val == CONSTANT | |
1420 | && TREE_CODE (ptrval.value) == INTEGER_CST) | |
cf8f0e63 | 1421 | || ptrval.mask.is_minus_one ()); |
fca0886c | 1422 | align = gimple_call_arg (stmt, 1); |
1423 | if (!host_integerp (align, 1)) | |
1424 | return ptrval; | |
1425 | aligni = tree_low_cst (align, 1); | |
1426 | if (aligni <= 1 | |
1427 | || (aligni & (aligni - 1)) != 0) | |
1428 | return ptrval; | |
1429 | if (gimple_call_num_args (stmt) > 2) | |
1430 | { | |
1431 | misalign = gimple_call_arg (stmt, 2); | |
1432 | if (!host_integerp (misalign, 1)) | |
1433 | return ptrval; | |
1434 | misaligni = tree_low_cst (misalign, 1); | |
1435 | if (misaligni >= aligni) | |
1436 | return ptrval; | |
1437 | } | |
1438 | align = build_int_cst_type (type, -aligni); | |
1439 | alignval = get_value_for_expr (align, true); | |
1440 | bit_value_binop_1 (BIT_AND_EXPR, type, &value, &mask, | |
1441 | type, value_to_double_int (ptrval), ptrval.mask, | |
1442 | type, value_to_double_int (alignval), alignval.mask); | |
cf8f0e63 | 1443 | if (!mask.is_minus_one ()) |
fca0886c | 1444 | { |
1445 | val.lattice_val = CONSTANT; | |
1446 | val.mask = mask; | |
1447 | gcc_assert ((mask.low & (aligni - 1)) == 0); | |
1448 | gcc_assert ((value.low & (aligni - 1)) == 0); | |
1449 | value.low |= misaligni; | |
1450 | /* ??? Delay building trees here. */ | |
1451 | val.value = double_int_to_tree (type, value); | |
1452 | } | |
1453 | else | |
1454 | { | |
1455 | val.lattice_val = VARYING; | |
1456 | val.value = NULL_TREE; | |
1457 | val.mask = double_int_minus_one; | |
1458 | } | |
1459 | return val; | |
1460 | } | |
1461 | ||
75a70cf9 | 1462 | /* Evaluate statement STMT. |
1463 | Valid only for assignments, calls, conditionals, and switches. */ | |
4ee9c684 | 1464 | |
88dbf20f | 1465 | static prop_value_t |
75a70cf9 | 1466 | evaluate_stmt (gimple stmt) |
4ee9c684 | 1467 | { |
88dbf20f | 1468 | prop_value_t val; |
4f61cce6 | 1469 | tree simplified = NULL_TREE; |
88dbf20f | 1470 | ccp_lattice_t likelyvalue = likely_value (stmt); |
b7e55469 | 1471 | bool is_constant = false; |
581bf1c2 | 1472 | unsigned int align; |
88dbf20f | 1473 | |
b7e55469 | 1474 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1475 | { | |
1476 | fprintf (dump_file, "which is likely "); | |
1477 | switch (likelyvalue) | |
1478 | { | |
1479 | case CONSTANT: | |
1480 | fprintf (dump_file, "CONSTANT"); | |
1481 | break; | |
1482 | case UNDEFINED: | |
1483 | fprintf (dump_file, "UNDEFINED"); | |
1484 | break; | |
1485 | case VARYING: | |
1486 | fprintf (dump_file, "VARYING"); | |
1487 | break; | |
1488 | default:; | |
1489 | } | |
1490 | fprintf (dump_file, "\n"); | |
1491 | } | |
add6ee5e | 1492 | |
4ee9c684 | 1493 | /* If the statement is likely to have a CONSTANT result, then try |
1494 | to fold the statement to determine the constant value. */ | |
75a70cf9 | 1495 | /* FIXME. This is the only place that we call ccp_fold. |
1496 | Since likely_value never returns CONSTANT for calls, we will | |
1497 | not attempt to fold them, including builtins that may profit. */ | |
4ee9c684 | 1498 | if (likelyvalue == CONSTANT) |
b7e55469 | 1499 | { |
1500 | fold_defer_overflow_warnings (); | |
1501 | simplified = ccp_fold (stmt); | |
1502 | is_constant = simplified && is_gimple_min_invariant (simplified); | |
1503 | fold_undefer_overflow_warnings (is_constant, stmt, 0); | |
1504 | if (is_constant) | |
1505 | { | |
1506 | /* The statement produced a constant value. */ | |
1507 | val.lattice_val = CONSTANT; | |
1508 | val.value = simplified; | |
1509 | val.mask = double_int_zero; | |
1510 | } | |
1511 | } | |
4ee9c684 | 1512 | /* If the statement is likely to have a VARYING result, then do not |
1513 | bother folding the statement. */ | |
04236c3a | 1514 | else if (likelyvalue == VARYING) |
75a70cf9 | 1515 | { |
590c3166 | 1516 | enum gimple_code code = gimple_code (stmt); |
75a70cf9 | 1517 | if (code == GIMPLE_ASSIGN) |
1518 | { | |
1519 | enum tree_code subcode = gimple_assign_rhs_code (stmt); | |
48e1416a | 1520 | |
75a70cf9 | 1521 | /* Other cases cannot satisfy is_gimple_min_invariant |
1522 | without folding. */ | |
1523 | if (get_gimple_rhs_class (subcode) == GIMPLE_SINGLE_RHS) | |
1524 | simplified = gimple_assign_rhs1 (stmt); | |
1525 | } | |
1526 | else if (code == GIMPLE_SWITCH) | |
1527 | simplified = gimple_switch_index (stmt); | |
1528 | else | |
a65c4d64 | 1529 | /* These cannot satisfy is_gimple_min_invariant without folding. */ |
1530 | gcc_assert (code == GIMPLE_CALL || code == GIMPLE_COND); | |
b7e55469 | 1531 | is_constant = simplified && is_gimple_min_invariant (simplified); |
1532 | if (is_constant) | |
1533 | { | |
1534 | /* The statement produced a constant value. */ | |
1535 | val.lattice_val = CONSTANT; | |
1536 | val.value = simplified; | |
1537 | val.mask = double_int_zero; | |
1538 | } | |
75a70cf9 | 1539 | } |
4ee9c684 | 1540 | |
b7e55469 | 1541 | /* Resort to simplification for bitwise tracking. */ |
1542 | if (flag_tree_bit_ccp | |
939514e9 | 1543 | && (likelyvalue == CONSTANT || is_gimple_call (stmt)) |
b7e55469 | 1544 | && !is_constant) |
912f109f | 1545 | { |
b7e55469 | 1546 | enum gimple_code code = gimple_code (stmt); |
153c3b50 | 1547 | tree fndecl; |
b7e55469 | 1548 | val.lattice_val = VARYING; |
1549 | val.value = NULL_TREE; | |
1550 | val.mask = double_int_minus_one; | |
1551 | if (code == GIMPLE_ASSIGN) | |
912f109f | 1552 | { |
b7e55469 | 1553 | enum tree_code subcode = gimple_assign_rhs_code (stmt); |
1554 | tree rhs1 = gimple_assign_rhs1 (stmt); | |
1555 | switch (get_gimple_rhs_class (subcode)) | |
1556 | { | |
1557 | case GIMPLE_SINGLE_RHS: | |
1558 | if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
1559 | || POINTER_TYPE_P (TREE_TYPE (rhs1))) | |
1560 | val = get_value_for_expr (rhs1, true); | |
1561 | break; | |
1562 | ||
1563 | case GIMPLE_UNARY_RHS: | |
1564 | if ((INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
1565 | || POINTER_TYPE_P (TREE_TYPE (rhs1))) | |
1566 | && (INTEGRAL_TYPE_P (gimple_expr_type (stmt)) | |
1567 | || POINTER_TYPE_P (gimple_expr_type (stmt)))) | |
1568 | val = bit_value_unop (subcode, gimple_expr_type (stmt), rhs1); | |
1569 | break; | |
1570 | ||
1571 | case GIMPLE_BINARY_RHS: | |
1572 | if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
1573 | || POINTER_TYPE_P (TREE_TYPE (rhs1))) | |
1574 | { | |
e47d81e0 | 1575 | tree lhs = gimple_assign_lhs (stmt); |
b7e55469 | 1576 | tree rhs2 = gimple_assign_rhs2 (stmt); |
1577 | val = bit_value_binop (subcode, | |
e47d81e0 | 1578 | TREE_TYPE (lhs), rhs1, rhs2); |
b7e55469 | 1579 | } |
1580 | break; | |
1581 | ||
1582 | default:; | |
1583 | } | |
912f109f | 1584 | } |
b7e55469 | 1585 | else if (code == GIMPLE_COND) |
1586 | { | |
1587 | enum tree_code code = gimple_cond_code (stmt); | |
1588 | tree rhs1 = gimple_cond_lhs (stmt); | |
1589 | tree rhs2 = gimple_cond_rhs (stmt); | |
1590 | if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
1591 | || POINTER_TYPE_P (TREE_TYPE (rhs1))) | |
1592 | val = bit_value_binop (code, TREE_TYPE (rhs1), rhs1, rhs2); | |
1593 | } | |
153c3b50 | 1594 | else if (code == GIMPLE_CALL |
1595 | && (fndecl = gimple_call_fndecl (stmt)) | |
1596 | && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL) | |
1597 | { | |
1598 | switch (DECL_FUNCTION_CODE (fndecl)) | |
1599 | { | |
1600 | case BUILT_IN_MALLOC: | |
1601 | case BUILT_IN_REALLOC: | |
1602 | case BUILT_IN_CALLOC: | |
939514e9 | 1603 | case BUILT_IN_STRDUP: |
1604 | case BUILT_IN_STRNDUP: | |
153c3b50 | 1605 | val.lattice_val = CONSTANT; |
1606 | val.value = build_int_cst (TREE_TYPE (gimple_get_lhs (stmt)), 0); | |
cf8f0e63 | 1607 | val.mask = double_int::from_shwi |
153c3b50 | 1608 | (~(((HOST_WIDE_INT) MALLOC_ABI_ALIGNMENT) |
1609 | / BITS_PER_UNIT - 1)); | |
1610 | break; | |
1611 | ||
1612 | case BUILT_IN_ALLOCA: | |
581bf1c2 | 1613 | case BUILT_IN_ALLOCA_WITH_ALIGN: |
1614 | align = (DECL_FUNCTION_CODE (fndecl) == BUILT_IN_ALLOCA_WITH_ALIGN | |
1615 | ? TREE_INT_CST_LOW (gimple_call_arg (stmt, 1)) | |
1616 | : BIGGEST_ALIGNMENT); | |
153c3b50 | 1617 | val.lattice_val = CONSTANT; |
1618 | val.value = build_int_cst (TREE_TYPE (gimple_get_lhs (stmt)), 0); | |
cf8f0e63 | 1619 | val.mask = double_int::from_shwi (~(((HOST_WIDE_INT) align) |
1620 | / BITS_PER_UNIT - 1)); | |
153c3b50 | 1621 | break; |
1622 | ||
939514e9 | 1623 | /* These builtins return their first argument, unmodified. */ |
1624 | case BUILT_IN_MEMCPY: | |
1625 | case BUILT_IN_MEMMOVE: | |
1626 | case BUILT_IN_MEMSET: | |
1627 | case BUILT_IN_STRCPY: | |
1628 | case BUILT_IN_STRNCPY: | |
1629 | case BUILT_IN_MEMCPY_CHK: | |
1630 | case BUILT_IN_MEMMOVE_CHK: | |
1631 | case BUILT_IN_MEMSET_CHK: | |
1632 | case BUILT_IN_STRCPY_CHK: | |
1633 | case BUILT_IN_STRNCPY_CHK: | |
1634 | val = get_value_for_expr (gimple_call_arg (stmt, 0), true); | |
1635 | break; | |
1636 | ||
fca0886c | 1637 | case BUILT_IN_ASSUME_ALIGNED: |
1638 | val = bit_value_assume_aligned (stmt); | |
1639 | break; | |
1640 | ||
153c3b50 | 1641 | default:; |
1642 | } | |
1643 | } | |
b7e55469 | 1644 | is_constant = (val.lattice_val == CONSTANT); |
912f109f | 1645 | } |
1646 | ||
b7e55469 | 1647 | if (!is_constant) |
4ee9c684 | 1648 | { |
1649 | /* The statement produced a nonconstant value. If the statement | |
88dbf20f | 1650 | had UNDEFINED operands, then the result of the statement |
1651 | should be UNDEFINED. Otherwise, the statement is VARYING. */ | |
bfa30570 | 1652 | if (likelyvalue == UNDEFINED) |
b7e55469 | 1653 | { |
1654 | val.lattice_val = likelyvalue; | |
1655 | val.mask = double_int_zero; | |
1656 | } | |
b765fa12 | 1657 | else |
b7e55469 | 1658 | { |
1659 | val.lattice_val = VARYING; | |
1660 | val.mask = double_int_minus_one; | |
1661 | } | |
b765fa12 | 1662 | |
88dbf20f | 1663 | val.value = NULL_TREE; |
4ee9c684 | 1664 | } |
41511585 | 1665 | |
1666 | return val; | |
4ee9c684 | 1667 | } |
1668 | ||
494bbaae | 1669 | typedef hash_table <pointer_hash <gimple_statement_d> > gimple_htab; |
2b15d2ba | 1670 | |
582a80ed | 1671 | /* Given a BUILT_IN_STACK_SAVE value SAVED_VAL, insert a clobber of VAR before |
1672 | each matching BUILT_IN_STACK_RESTORE. Mark visited phis in VISITED. */ | |
1673 | ||
1674 | static void | |
2b15d2ba | 1675 | insert_clobber_before_stack_restore (tree saved_val, tree var, |
1676 | gimple_htab *visited) | |
582a80ed | 1677 | { |
1678 | gimple stmt, clobber_stmt; | |
1679 | tree clobber; | |
1680 | imm_use_iterator iter; | |
1681 | gimple_stmt_iterator i; | |
1682 | gimple *slot; | |
1683 | ||
1684 | FOR_EACH_IMM_USE_STMT (stmt, iter, saved_val) | |
1685 | if (gimple_call_builtin_p (stmt, BUILT_IN_STACK_RESTORE)) | |
1686 | { | |
1687 | clobber = build_constructor (TREE_TYPE (var), NULL); | |
1688 | TREE_THIS_VOLATILE (clobber) = 1; | |
1689 | clobber_stmt = gimple_build_assign (var, clobber); | |
1690 | ||
1691 | i = gsi_for_stmt (stmt); | |
1692 | gsi_insert_before (&i, clobber_stmt, GSI_SAME_STMT); | |
1693 | } | |
1694 | else if (gimple_code (stmt) == GIMPLE_PHI) | |
1695 | { | |
2b15d2ba | 1696 | if (!visited->is_created ()) |
1697 | visited->create (10); | |
582a80ed | 1698 | |
2b15d2ba | 1699 | slot = visited->find_slot (stmt, INSERT); |
582a80ed | 1700 | if (*slot != NULL) |
1701 | continue; | |
1702 | ||
1703 | *slot = stmt; | |
1704 | insert_clobber_before_stack_restore (gimple_phi_result (stmt), var, | |
1705 | visited); | |
1706 | } | |
1707 | else | |
1708 | gcc_assert (is_gimple_debug (stmt)); | |
1709 | } | |
1710 | ||
1711 | /* Advance the iterator to the previous non-debug gimple statement in the same | |
1712 | or dominating basic block. */ | |
1713 | ||
1714 | static inline void | |
1715 | gsi_prev_dom_bb_nondebug (gimple_stmt_iterator *i) | |
1716 | { | |
1717 | basic_block dom; | |
1718 | ||
1719 | gsi_prev_nondebug (i); | |
1720 | while (gsi_end_p (*i)) | |
1721 | { | |
1722 | dom = get_immediate_dominator (CDI_DOMINATORS, i->bb); | |
1723 | if (dom == NULL || dom == ENTRY_BLOCK_PTR) | |
1724 | return; | |
1725 | ||
1726 | *i = gsi_last_bb (dom); | |
1727 | } | |
1728 | } | |
1729 | ||
1730 | /* Find a BUILT_IN_STACK_SAVE dominating gsi_stmt (I), and insert | |
1543f720 | 1731 | a clobber of VAR before each matching BUILT_IN_STACK_RESTORE. |
1732 | ||
1733 | It is possible that BUILT_IN_STACK_SAVE cannot be find in a dominator when a | |
1734 | previous pass (such as DOM) duplicated it along multiple paths to a BB. In | |
1735 | that case the function gives up without inserting the clobbers. */ | |
582a80ed | 1736 | |
1737 | static void | |
1738 | insert_clobbers_for_var (gimple_stmt_iterator i, tree var) | |
1739 | { | |
582a80ed | 1740 | gimple stmt; |
1741 | tree saved_val; | |
2b15d2ba | 1742 | gimple_htab visited; |
582a80ed | 1743 | |
1543f720 | 1744 | for (; !gsi_end_p (i); gsi_prev_dom_bb_nondebug (&i)) |
582a80ed | 1745 | { |
1746 | stmt = gsi_stmt (i); | |
1747 | ||
1748 | if (!gimple_call_builtin_p (stmt, BUILT_IN_STACK_SAVE)) | |
1749 | continue; | |
582a80ed | 1750 | |
1751 | saved_val = gimple_call_lhs (stmt); | |
1752 | if (saved_val == NULL_TREE) | |
1753 | continue; | |
1754 | ||
1755 | insert_clobber_before_stack_restore (saved_val, var, &visited); | |
1756 | break; | |
1757 | } | |
1758 | ||
2b15d2ba | 1759 | if (visited.is_created ()) |
1760 | visited.dispose (); | |
582a80ed | 1761 | } |
1762 | ||
581bf1c2 | 1763 | /* Detects a __builtin_alloca_with_align with constant size argument. Declares |
1764 | fixed-size array and returns the address, if found, otherwise returns | |
1765 | NULL_TREE. */ | |
9a65cc0a | 1766 | |
1767 | static tree | |
581bf1c2 | 1768 | fold_builtin_alloca_with_align (gimple stmt) |
9a65cc0a | 1769 | { |
1770 | unsigned HOST_WIDE_INT size, threshold, n_elem; | |
1771 | tree lhs, arg, block, var, elem_type, array_type; | |
9a65cc0a | 1772 | |
1773 | /* Get lhs. */ | |
1774 | lhs = gimple_call_lhs (stmt); | |
1775 | if (lhs == NULL_TREE) | |
1776 | return NULL_TREE; | |
1777 | ||
1778 | /* Detect constant argument. */ | |
1779 | arg = get_constant_value (gimple_call_arg (stmt, 0)); | |
6e93d308 | 1780 | if (arg == NULL_TREE |
1781 | || TREE_CODE (arg) != INTEGER_CST | |
9a65cc0a | 1782 | || !host_integerp (arg, 1)) |
1783 | return NULL_TREE; | |
6e93d308 | 1784 | |
9a65cc0a | 1785 | size = TREE_INT_CST_LOW (arg); |
1786 | ||
581bf1c2 | 1787 | /* Heuristic: don't fold large allocas. */ |
9a65cc0a | 1788 | threshold = (unsigned HOST_WIDE_INT)PARAM_VALUE (PARAM_LARGE_STACK_FRAME); |
581bf1c2 | 1789 | /* In case the alloca is located at function entry, it has the same lifetime |
1790 | as a declared array, so we allow a larger size. */ | |
9a65cc0a | 1791 | block = gimple_block (stmt); |
1792 | if (!(cfun->after_inlining | |
1793 | && TREE_CODE (BLOCK_SUPERCONTEXT (block)) == FUNCTION_DECL)) | |
1794 | threshold /= 10; | |
1795 | if (size > threshold) | |
1796 | return NULL_TREE; | |
1797 | ||
1798 | /* Declare array. */ | |
1799 | elem_type = build_nonstandard_integer_type (BITS_PER_UNIT, 1); | |
1800 | n_elem = size * 8 / BITS_PER_UNIT; | |
9a65cc0a | 1801 | array_type = build_array_type_nelts (elem_type, n_elem); |
1802 | var = create_tmp_var (array_type, NULL); | |
581bf1c2 | 1803 | DECL_ALIGN (var) = TREE_INT_CST_LOW (gimple_call_arg (stmt, 1)); |
3d4a0a4b | 1804 | { |
1805 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (lhs); | |
1806 | if (pi != NULL && !pi->pt.anything) | |
1807 | { | |
1808 | bool singleton_p; | |
1809 | unsigned uid; | |
1810 | singleton_p = pt_solution_singleton_p (&pi->pt, &uid); | |
1811 | gcc_assert (singleton_p); | |
1812 | SET_DECL_PT_UID (var, uid); | |
1813 | } | |
1814 | } | |
9a65cc0a | 1815 | |
1816 | /* Fold alloca to the address of the array. */ | |
1817 | return fold_convert (TREE_TYPE (lhs), build_fold_addr_expr (var)); | |
1818 | } | |
1819 | ||
6688f8ec | 1820 | /* Fold the stmt at *GSI with CCP specific information that propagating |
1821 | and regular folding does not catch. */ | |
1822 | ||
1823 | static bool | |
1824 | ccp_fold_stmt (gimple_stmt_iterator *gsi) | |
1825 | { | |
1826 | gimple stmt = gsi_stmt (*gsi); | |
6688f8ec | 1827 | |
94144e68 | 1828 | switch (gimple_code (stmt)) |
1829 | { | |
1830 | case GIMPLE_COND: | |
1831 | { | |
1832 | prop_value_t val; | |
1833 | /* Statement evaluation will handle type mismatches in constants | |
1834 | more gracefully than the final propagation. This allows us to | |
1835 | fold more conditionals here. */ | |
1836 | val = evaluate_stmt (stmt); | |
1837 | if (val.lattice_val != CONSTANT | |
cf8f0e63 | 1838 | || !val.mask.is_zero ()) |
94144e68 | 1839 | return false; |
1840 | ||
b7e55469 | 1841 | if (dump_file) |
1842 | { | |
1843 | fprintf (dump_file, "Folding predicate "); | |
1844 | print_gimple_expr (dump_file, stmt, 0, 0); | |
1845 | fprintf (dump_file, " to "); | |
1846 | print_generic_expr (dump_file, val.value, 0); | |
1847 | fprintf (dump_file, "\n"); | |
1848 | } | |
1849 | ||
94144e68 | 1850 | if (integer_zerop (val.value)) |
1851 | gimple_cond_make_false (stmt); | |
1852 | else | |
1853 | gimple_cond_make_true (stmt); | |
6688f8ec | 1854 | |
94144e68 | 1855 | return true; |
1856 | } | |
6688f8ec | 1857 | |
94144e68 | 1858 | case GIMPLE_CALL: |
1859 | { | |
1860 | tree lhs = gimple_call_lhs (stmt); | |
3064bb7b | 1861 | int flags = gimple_call_flags (stmt); |
15d138c9 | 1862 | tree val; |
94144e68 | 1863 | tree argt; |
1864 | bool changed = false; | |
1865 | unsigned i; | |
1866 | ||
1867 | /* If the call was folded into a constant make sure it goes | |
1868 | away even if we cannot propagate into all uses because of | |
1869 | type issues. */ | |
1870 | if (lhs | |
1871 | && TREE_CODE (lhs) == SSA_NAME | |
3064bb7b | 1872 | && (val = get_constant_value (lhs)) |
1873 | /* Don't optimize away calls that have side-effects. */ | |
1874 | && (flags & (ECF_CONST|ECF_PURE)) != 0 | |
1875 | && (flags & ECF_LOOPING_CONST_OR_PURE) == 0) | |
94144e68 | 1876 | { |
15d138c9 | 1877 | tree new_rhs = unshare_expr (val); |
338cce8f | 1878 | bool res; |
94144e68 | 1879 | if (!useless_type_conversion_p (TREE_TYPE (lhs), |
1880 | TREE_TYPE (new_rhs))) | |
1881 | new_rhs = fold_convert (TREE_TYPE (lhs), new_rhs); | |
338cce8f | 1882 | res = update_call_from_tree (gsi, new_rhs); |
1883 | gcc_assert (res); | |
94144e68 | 1884 | return true; |
1885 | } | |
1886 | ||
fb049fba | 1887 | /* Internal calls provide no argument types, so the extra laxity |
1888 | for normal calls does not apply. */ | |
1889 | if (gimple_call_internal_p (stmt)) | |
1890 | return false; | |
1891 | ||
581bf1c2 | 1892 | /* The heuristic of fold_builtin_alloca_with_align differs before and |
1893 | after inlining, so we don't require the arg to be changed into a | |
1894 | constant for folding, but just to be constant. */ | |
1895 | if (gimple_call_builtin_p (stmt, BUILT_IN_ALLOCA_WITH_ALIGN)) | |
9a65cc0a | 1896 | { |
581bf1c2 | 1897 | tree new_rhs = fold_builtin_alloca_with_align (stmt); |
6e93d308 | 1898 | if (new_rhs) |
1899 | { | |
1900 | bool res = update_call_from_tree (gsi, new_rhs); | |
582a80ed | 1901 | tree var = TREE_OPERAND (TREE_OPERAND (new_rhs, 0),0); |
6e93d308 | 1902 | gcc_assert (res); |
582a80ed | 1903 | insert_clobbers_for_var (*gsi, var); |
6e93d308 | 1904 | return true; |
1905 | } | |
9a65cc0a | 1906 | } |
1907 | ||
94144e68 | 1908 | /* Propagate into the call arguments. Compared to replace_uses_in |
1909 | this can use the argument slot types for type verification | |
1910 | instead of the current argument type. We also can safely | |
1911 | drop qualifiers here as we are dealing with constants anyway. */ | |
2de00a2d | 1912 | argt = TYPE_ARG_TYPES (gimple_call_fntype (stmt)); |
94144e68 | 1913 | for (i = 0; i < gimple_call_num_args (stmt) && argt; |
1914 | ++i, argt = TREE_CHAIN (argt)) | |
1915 | { | |
1916 | tree arg = gimple_call_arg (stmt, i); | |
1917 | if (TREE_CODE (arg) == SSA_NAME | |
15d138c9 | 1918 | && (val = get_constant_value (arg)) |
94144e68 | 1919 | && useless_type_conversion_p |
1920 | (TYPE_MAIN_VARIANT (TREE_VALUE (argt)), | |
15d138c9 | 1921 | TYPE_MAIN_VARIANT (TREE_TYPE (val)))) |
94144e68 | 1922 | { |
15d138c9 | 1923 | gimple_call_set_arg (stmt, i, unshare_expr (val)); |
94144e68 | 1924 | changed = true; |
1925 | } | |
1926 | } | |
e16f4c39 | 1927 | |
94144e68 | 1928 | return changed; |
1929 | } | |
6688f8ec | 1930 | |
6872bf3c | 1931 | case GIMPLE_ASSIGN: |
1932 | { | |
1933 | tree lhs = gimple_assign_lhs (stmt); | |
15d138c9 | 1934 | tree val; |
6872bf3c | 1935 | |
1936 | /* If we have a load that turned out to be constant replace it | |
1937 | as we cannot propagate into all uses in all cases. */ | |
1938 | if (gimple_assign_single_p (stmt) | |
1939 | && TREE_CODE (lhs) == SSA_NAME | |
15d138c9 | 1940 | && (val = get_constant_value (lhs))) |
6872bf3c | 1941 | { |
15d138c9 | 1942 | tree rhs = unshare_expr (val); |
6872bf3c | 1943 | if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs))) |
182cf5a9 | 1944 | rhs = fold_build1 (VIEW_CONVERT_EXPR, TREE_TYPE (lhs), rhs); |
6872bf3c | 1945 | gimple_assign_set_rhs_from_tree (gsi, rhs); |
1946 | return true; | |
1947 | } | |
1948 | ||
1949 | return false; | |
1950 | } | |
1951 | ||
94144e68 | 1952 | default: |
1953 | return false; | |
1954 | } | |
6688f8ec | 1955 | } |
1956 | ||
41511585 | 1957 | /* Visit the assignment statement STMT. Set the value of its LHS to the |
88dbf20f | 1958 | value computed by the RHS and store LHS in *OUTPUT_P. If STMT |
1959 | creates virtual definitions, set the value of each new name to that | |
75a70cf9 | 1960 | of the RHS (if we can derive a constant out of the RHS). |
1961 | Value-returning call statements also perform an assignment, and | |
1962 | are handled here. */ | |
4ee9c684 | 1963 | |
41511585 | 1964 | static enum ssa_prop_result |
75a70cf9 | 1965 | visit_assignment (gimple stmt, tree *output_p) |
4ee9c684 | 1966 | { |
88dbf20f | 1967 | prop_value_t val; |
88dbf20f | 1968 | enum ssa_prop_result retval; |
4ee9c684 | 1969 | |
75a70cf9 | 1970 | tree lhs = gimple_get_lhs (stmt); |
4ee9c684 | 1971 | |
75a70cf9 | 1972 | gcc_assert (gimple_code (stmt) != GIMPLE_CALL |
1973 | || gimple_call_lhs (stmt) != NULL_TREE); | |
1974 | ||
15d138c9 | 1975 | if (gimple_assign_single_p (stmt) |
1976 | && gimple_assign_rhs_code (stmt) == SSA_NAME) | |
1977 | /* For a simple copy operation, we copy the lattice values. */ | |
1978 | val = *get_value (gimple_assign_rhs1 (stmt)); | |
41511585 | 1979 | else |
75a70cf9 | 1980 | /* Evaluate the statement, which could be |
1981 | either a GIMPLE_ASSIGN or a GIMPLE_CALL. */ | |
04236c3a | 1982 | val = evaluate_stmt (stmt); |
4ee9c684 | 1983 | |
88dbf20f | 1984 | retval = SSA_PROP_NOT_INTERESTING; |
4ee9c684 | 1985 | |
41511585 | 1986 | /* Set the lattice value of the statement's output. */ |
88dbf20f | 1987 | if (TREE_CODE (lhs) == SSA_NAME) |
4ee9c684 | 1988 | { |
88dbf20f | 1989 | /* If STMT is an assignment to an SSA_NAME, we only have one |
1990 | value to set. */ | |
1991 | if (set_lattice_value (lhs, val)) | |
1992 | { | |
1993 | *output_p = lhs; | |
1994 | if (val.lattice_val == VARYING) | |
1995 | retval = SSA_PROP_VARYING; | |
1996 | else | |
1997 | retval = SSA_PROP_INTERESTING; | |
1998 | } | |
4ee9c684 | 1999 | } |
88dbf20f | 2000 | |
2001 | return retval; | |
4ee9c684 | 2002 | } |
2003 | ||
4ee9c684 | 2004 | |
41511585 | 2005 | /* Visit the conditional statement STMT. Return SSA_PROP_INTERESTING |
2006 | if it can determine which edge will be taken. Otherwise, return | |
2007 | SSA_PROP_VARYING. */ | |
2008 | ||
2009 | static enum ssa_prop_result | |
75a70cf9 | 2010 | visit_cond_stmt (gimple stmt, edge *taken_edge_p) |
4ee9c684 | 2011 | { |
88dbf20f | 2012 | prop_value_t val; |
41511585 | 2013 | basic_block block; |
2014 | ||
75a70cf9 | 2015 | block = gimple_bb (stmt); |
41511585 | 2016 | val = evaluate_stmt (stmt); |
b7e55469 | 2017 | if (val.lattice_val != CONSTANT |
cf8f0e63 | 2018 | || !val.mask.is_zero ()) |
b7e55469 | 2019 | return SSA_PROP_VARYING; |
41511585 | 2020 | |
2021 | /* Find which edge out of the conditional block will be taken and add it | |
2022 | to the worklist. If no single edge can be determined statically, | |
2023 | return SSA_PROP_VARYING to feed all the outgoing edges to the | |
2024 | propagation engine. */ | |
b7e55469 | 2025 | *taken_edge_p = find_taken_edge (block, val.value); |
41511585 | 2026 | if (*taken_edge_p) |
2027 | return SSA_PROP_INTERESTING; | |
2028 | else | |
2029 | return SSA_PROP_VARYING; | |
4ee9c684 | 2030 | } |
2031 | ||
4ee9c684 | 2032 | |
41511585 | 2033 | /* Evaluate statement STMT. If the statement produces an output value and |
2034 | its evaluation changes the lattice value of its output, return | |
2035 | SSA_PROP_INTERESTING and set *OUTPUT_P to the SSA_NAME holding the | |
2036 | output value. | |
48e1416a | 2037 | |
41511585 | 2038 | If STMT is a conditional branch and we can determine its truth |
2039 | value, set *TAKEN_EDGE_P accordingly. If STMT produces a varying | |
2040 | value, return SSA_PROP_VARYING. */ | |
4ee9c684 | 2041 | |
41511585 | 2042 | static enum ssa_prop_result |
75a70cf9 | 2043 | ccp_visit_stmt (gimple stmt, edge *taken_edge_p, tree *output_p) |
41511585 | 2044 | { |
41511585 | 2045 | tree def; |
2046 | ssa_op_iter iter; | |
4ee9c684 | 2047 | |
41511585 | 2048 | if (dump_file && (dump_flags & TDF_DETAILS)) |
4ee9c684 | 2049 | { |
88dbf20f | 2050 | fprintf (dump_file, "\nVisiting statement:\n"); |
75a70cf9 | 2051 | print_gimple_stmt (dump_file, stmt, 0, dump_flags); |
4ee9c684 | 2052 | } |
4ee9c684 | 2053 | |
75a70cf9 | 2054 | switch (gimple_code (stmt)) |
4ee9c684 | 2055 | { |
75a70cf9 | 2056 | case GIMPLE_ASSIGN: |
2057 | /* If the statement is an assignment that produces a single | |
2058 | output value, evaluate its RHS to see if the lattice value of | |
2059 | its output has changed. */ | |
2060 | return visit_assignment (stmt, output_p); | |
2061 | ||
2062 | case GIMPLE_CALL: | |
2063 | /* A value-returning call also performs an assignment. */ | |
2064 | if (gimple_call_lhs (stmt) != NULL_TREE) | |
2065 | return visit_assignment (stmt, output_p); | |
2066 | break; | |
2067 | ||
2068 | case GIMPLE_COND: | |
2069 | case GIMPLE_SWITCH: | |
2070 | /* If STMT is a conditional branch, see if we can determine | |
2071 | which branch will be taken. */ | |
2072 | /* FIXME. It appears that we should be able to optimize | |
2073 | computed GOTOs here as well. */ | |
2074 | return visit_cond_stmt (stmt, taken_edge_p); | |
2075 | ||
2076 | default: | |
2077 | break; | |
4ee9c684 | 2078 | } |
4ee9c684 | 2079 | |
41511585 | 2080 | /* Any other kind of statement is not interesting for constant |
2081 | propagation and, therefore, not worth simulating. */ | |
41511585 | 2082 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2083 | fprintf (dump_file, "No interesting values produced. Marked VARYING.\n"); | |
4ee9c684 | 2084 | |
41511585 | 2085 | /* Definitions made by statements other than assignments to |
2086 | SSA_NAMEs represent unknown modifications to their outputs. | |
2087 | Mark them VARYING. */ | |
88dbf20f | 2088 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS) |
2089 | { | |
b7e55469 | 2090 | prop_value_t v = { VARYING, NULL_TREE, { -1, (HOST_WIDE_INT) -1 } }; |
88dbf20f | 2091 | set_lattice_value (def, v); |
2092 | } | |
4ee9c684 | 2093 | |
41511585 | 2094 | return SSA_PROP_VARYING; |
2095 | } | |
4ee9c684 | 2096 | |
4ee9c684 | 2097 | |
88dbf20f | 2098 | /* Main entry point for SSA Conditional Constant Propagation. */ |
41511585 | 2099 | |
33a34f1e | 2100 | static unsigned int |
61207d43 | 2101 | do_ssa_ccp (void) |
41511585 | 2102 | { |
582a80ed | 2103 | unsigned int todo = 0; |
2104 | calculate_dominance_info (CDI_DOMINATORS); | |
41511585 | 2105 | ccp_initialize (); |
2106 | ssa_propagate (ccp_visit_stmt, ccp_visit_phi_node); | |
33a34f1e | 2107 | if (ccp_finalize ()) |
582a80ed | 2108 | todo = (TODO_cleanup_cfg | TODO_update_ssa | TODO_remove_unused_locals); |
2109 | free_dominance_info (CDI_DOMINATORS); | |
2110 | return todo; | |
4ee9c684 | 2111 | } |
2112 | ||
5664499b | 2113 | |
2114 | static bool | |
41511585 | 2115 | gate_ccp (void) |
5664499b | 2116 | { |
41511585 | 2117 | return flag_tree_ccp != 0; |
5664499b | 2118 | } |
2119 | ||
4ee9c684 | 2120 | |
48e1416a | 2121 | struct gimple_opt_pass pass_ccp = |
41511585 | 2122 | { |
20099e35 | 2123 | { |
2124 | GIMPLE_PASS, | |
41511585 | 2125 | "ccp", /* name */ |
c7875731 | 2126 | OPTGROUP_NONE, /* optinfo_flags */ |
41511585 | 2127 | gate_ccp, /* gate */ |
88dbf20f | 2128 | do_ssa_ccp, /* execute */ |
41511585 | 2129 | NULL, /* sub */ |
2130 | NULL, /* next */ | |
2131 | 0, /* static_pass_number */ | |
2132 | TV_TREE_CCP, /* tv_id */ | |
49290934 | 2133 | PROP_cfg | PROP_ssa, /* properties_required */ |
41511585 | 2134 | 0, /* properties_provided */ |
b6246c40 | 2135 | 0, /* properties_destroyed */ |
41511585 | 2136 | 0, /* todo_flags_start */ |
771e2890 | 2137 | TODO_verify_ssa |
5b48275c | 2138 | | TODO_update_address_taken |
20099e35 | 2139 | | TODO_verify_stmts | TODO_ggc_collect/* todo_flags_finish */ |
2140 | } | |
41511585 | 2141 | }; |
4ee9c684 | 2142 | |
4ee9c684 | 2143 | |
75a70cf9 | 2144 | |
bdd0e199 | 2145 | /* Try to optimize out __builtin_stack_restore. Optimize it out |
2146 | if there is another __builtin_stack_restore in the same basic | |
2147 | block and no calls or ASM_EXPRs are in between, or if this block's | |
2148 | only outgoing edge is to EXIT_BLOCK and there are no calls or | |
2149 | ASM_EXPRs after this __builtin_stack_restore. */ | |
2150 | ||
2151 | static tree | |
75a70cf9 | 2152 | optimize_stack_restore (gimple_stmt_iterator i) |
bdd0e199 | 2153 | { |
6ea999da | 2154 | tree callee; |
2155 | gimple stmt; | |
75a70cf9 | 2156 | |
2157 | basic_block bb = gsi_bb (i); | |
2158 | gimple call = gsi_stmt (i); | |
bdd0e199 | 2159 | |
75a70cf9 | 2160 | if (gimple_code (call) != GIMPLE_CALL |
2161 | || gimple_call_num_args (call) != 1 | |
2162 | || TREE_CODE (gimple_call_arg (call, 0)) != SSA_NAME | |
2163 | || !POINTER_TYPE_P (TREE_TYPE (gimple_call_arg (call, 0)))) | |
bdd0e199 | 2164 | return NULL_TREE; |
2165 | ||
75a70cf9 | 2166 | for (gsi_next (&i); !gsi_end_p (i); gsi_next (&i)) |
bdd0e199 | 2167 | { |
75a70cf9 | 2168 | stmt = gsi_stmt (i); |
2169 | if (gimple_code (stmt) == GIMPLE_ASM) | |
bdd0e199 | 2170 | return NULL_TREE; |
75a70cf9 | 2171 | if (gimple_code (stmt) != GIMPLE_CALL) |
bdd0e199 | 2172 | continue; |
2173 | ||
75a70cf9 | 2174 | callee = gimple_call_fndecl (stmt); |
c40a6f90 | 2175 | if (!callee |
2176 | || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL | |
2177 | /* All regular builtins are ok, just obviously not alloca. */ | |
581bf1c2 | 2178 | || DECL_FUNCTION_CODE (callee) == BUILT_IN_ALLOCA |
2179 | || DECL_FUNCTION_CODE (callee) == BUILT_IN_ALLOCA_WITH_ALIGN) | |
bdd0e199 | 2180 | return NULL_TREE; |
2181 | ||
2182 | if (DECL_FUNCTION_CODE (callee) == BUILT_IN_STACK_RESTORE) | |
6ea999da | 2183 | goto second_stack_restore; |
bdd0e199 | 2184 | } |
2185 | ||
6ea999da | 2186 | if (!gsi_end_p (i)) |
bdd0e199 | 2187 | return NULL_TREE; |
2188 | ||
6ea999da | 2189 | /* Allow one successor of the exit block, or zero successors. */ |
2190 | switch (EDGE_COUNT (bb->succs)) | |
2191 | { | |
2192 | case 0: | |
2193 | break; | |
2194 | case 1: | |
2195 | if (single_succ_edge (bb)->dest != EXIT_BLOCK_PTR) | |
2196 | return NULL_TREE; | |
2197 | break; | |
2198 | default: | |
2199 | return NULL_TREE; | |
2200 | } | |
2201 | second_stack_restore: | |
bdd0e199 | 2202 | |
6ea999da | 2203 | /* If there's exactly one use, then zap the call to __builtin_stack_save. |
2204 | If there are multiple uses, then the last one should remove the call. | |
2205 | In any case, whether the call to __builtin_stack_save can be removed | |
2206 | or not is irrelevant to removing the call to __builtin_stack_restore. */ | |
2207 | if (has_single_use (gimple_call_arg (call, 0))) | |
2208 | { | |
2209 | gimple stack_save = SSA_NAME_DEF_STMT (gimple_call_arg (call, 0)); | |
2210 | if (is_gimple_call (stack_save)) | |
2211 | { | |
2212 | callee = gimple_call_fndecl (stack_save); | |
2213 | if (callee | |
2214 | && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL | |
2215 | && DECL_FUNCTION_CODE (callee) == BUILT_IN_STACK_SAVE) | |
2216 | { | |
2217 | gimple_stmt_iterator stack_save_gsi; | |
2218 | tree rhs; | |
bdd0e199 | 2219 | |
6ea999da | 2220 | stack_save_gsi = gsi_for_stmt (stack_save); |
2221 | rhs = build_int_cst (TREE_TYPE (gimple_call_arg (call, 0)), 0); | |
2222 | update_call_from_tree (&stack_save_gsi, rhs); | |
2223 | } | |
2224 | } | |
2225 | } | |
bdd0e199 | 2226 | |
75a70cf9 | 2227 | /* No effect, so the statement will be deleted. */ |
bdd0e199 | 2228 | return integer_zero_node; |
2229 | } | |
75a70cf9 | 2230 | |
8a58ed0a | 2231 | /* If va_list type is a simple pointer and nothing special is needed, |
2232 | optimize __builtin_va_start (&ap, 0) into ap = __builtin_next_arg (0), | |
2233 | __builtin_va_end (&ap) out as NOP and __builtin_va_copy into a simple | |
2234 | pointer assignment. */ | |
2235 | ||
2236 | static tree | |
75a70cf9 | 2237 | optimize_stdarg_builtin (gimple call) |
8a58ed0a | 2238 | { |
5f57a8b1 | 2239 | tree callee, lhs, rhs, cfun_va_list; |
8a58ed0a | 2240 | bool va_list_simple_ptr; |
389dd41b | 2241 | location_t loc = gimple_location (call); |
8a58ed0a | 2242 | |
75a70cf9 | 2243 | if (gimple_code (call) != GIMPLE_CALL) |
8a58ed0a | 2244 | return NULL_TREE; |
2245 | ||
75a70cf9 | 2246 | callee = gimple_call_fndecl (call); |
5f57a8b1 | 2247 | |
2248 | cfun_va_list = targetm.fn_abi_va_list (callee); | |
2249 | va_list_simple_ptr = POINTER_TYPE_P (cfun_va_list) | |
2250 | && (TREE_TYPE (cfun_va_list) == void_type_node | |
2251 | || TREE_TYPE (cfun_va_list) == char_type_node); | |
2252 | ||
8a58ed0a | 2253 | switch (DECL_FUNCTION_CODE (callee)) |
2254 | { | |
2255 | case BUILT_IN_VA_START: | |
2256 | if (!va_list_simple_ptr | |
2257 | || targetm.expand_builtin_va_start != NULL | |
e7ed5dd7 | 2258 | || !builtin_decl_explicit_p (BUILT_IN_NEXT_ARG)) |
8a58ed0a | 2259 | return NULL_TREE; |
2260 | ||
75a70cf9 | 2261 | if (gimple_call_num_args (call) != 2) |
8a58ed0a | 2262 | return NULL_TREE; |
2263 | ||
75a70cf9 | 2264 | lhs = gimple_call_arg (call, 0); |
8a58ed0a | 2265 | if (!POINTER_TYPE_P (TREE_TYPE (lhs)) |
2266 | || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs))) | |
5f57a8b1 | 2267 | != TYPE_MAIN_VARIANT (cfun_va_list)) |
8a58ed0a | 2268 | return NULL_TREE; |
48e1416a | 2269 | |
389dd41b | 2270 | lhs = build_fold_indirect_ref_loc (loc, lhs); |
b9a16870 | 2271 | rhs = build_call_expr_loc (loc, builtin_decl_explicit (BUILT_IN_NEXT_ARG), |
75a70cf9 | 2272 | 1, integer_zero_node); |
389dd41b | 2273 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); |
8a58ed0a | 2274 | return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs); |
2275 | ||
2276 | case BUILT_IN_VA_COPY: | |
2277 | if (!va_list_simple_ptr) | |
2278 | return NULL_TREE; | |
2279 | ||
75a70cf9 | 2280 | if (gimple_call_num_args (call) != 2) |
8a58ed0a | 2281 | return NULL_TREE; |
2282 | ||
75a70cf9 | 2283 | lhs = gimple_call_arg (call, 0); |
8a58ed0a | 2284 | if (!POINTER_TYPE_P (TREE_TYPE (lhs)) |
2285 | || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs))) | |
5f57a8b1 | 2286 | != TYPE_MAIN_VARIANT (cfun_va_list)) |
8a58ed0a | 2287 | return NULL_TREE; |
2288 | ||
389dd41b | 2289 | lhs = build_fold_indirect_ref_loc (loc, lhs); |
75a70cf9 | 2290 | rhs = gimple_call_arg (call, 1); |
8a58ed0a | 2291 | if (TYPE_MAIN_VARIANT (TREE_TYPE (rhs)) |
5f57a8b1 | 2292 | != TYPE_MAIN_VARIANT (cfun_va_list)) |
8a58ed0a | 2293 | return NULL_TREE; |
2294 | ||
389dd41b | 2295 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); |
8a58ed0a | 2296 | return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs); |
2297 | ||
2298 | case BUILT_IN_VA_END: | |
75a70cf9 | 2299 | /* No effect, so the statement will be deleted. */ |
8a58ed0a | 2300 | return integer_zero_node; |
2301 | ||
2302 | default: | |
2303 | gcc_unreachable (); | |
2304 | } | |
2305 | } | |
75a70cf9 | 2306 | |
f87df69a | 2307 | /* Attemp to make the block of __builtin_unreachable I unreachable by changing |
2308 | the incoming jumps. Return true if at least one jump was changed. */ | |
2309 | ||
2310 | static bool | |
2311 | optimize_unreachable (gimple_stmt_iterator i) | |
2312 | { | |
2313 | basic_block bb = gsi_bb (i); | |
2314 | gimple_stmt_iterator gsi; | |
2315 | gimple stmt; | |
2316 | edge_iterator ei; | |
2317 | edge e; | |
2318 | bool ret; | |
2319 | ||
2320 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
2321 | { | |
2322 | stmt = gsi_stmt (gsi); | |
2323 | ||
2324 | if (is_gimple_debug (stmt)) | |
2325 | continue; | |
2326 | ||
2327 | if (gimple_code (stmt) == GIMPLE_LABEL) | |
2328 | { | |
2329 | /* Verify we do not need to preserve the label. */ | |
2330 | if (FORCED_LABEL (gimple_label_label (stmt))) | |
2331 | return false; | |
2332 | ||
2333 | continue; | |
2334 | } | |
2335 | ||
2336 | /* Only handle the case that __builtin_unreachable is the first statement | |
2337 | in the block. We rely on DCE to remove stmts without side-effects | |
2338 | before __builtin_unreachable. */ | |
2339 | if (gsi_stmt (gsi) != gsi_stmt (i)) | |
2340 | return false; | |
2341 | } | |
2342 | ||
2343 | ret = false; | |
2344 | FOR_EACH_EDGE (e, ei, bb->preds) | |
2345 | { | |
2346 | gsi = gsi_last_bb (e->src); | |
522f73a1 | 2347 | if (gsi_end_p (gsi)) |
2348 | continue; | |
f87df69a | 2349 | |
522f73a1 | 2350 | stmt = gsi_stmt (gsi); |
2351 | if (gimple_code (stmt) == GIMPLE_COND) | |
f87df69a | 2352 | { |
2353 | if (e->flags & EDGE_TRUE_VALUE) | |
2354 | gimple_cond_make_false (stmt); | |
2355 | else if (e->flags & EDGE_FALSE_VALUE) | |
2356 | gimple_cond_make_true (stmt); | |
2357 | else | |
2358 | gcc_unreachable (); | |
a03a52b4 | 2359 | update_stmt (stmt); |
f87df69a | 2360 | } |
2361 | else | |
2362 | { | |
2363 | /* Todo: handle other cases, f.i. switch statement. */ | |
2364 | continue; | |
2365 | } | |
2366 | ||
2367 | ret = true; | |
2368 | } | |
2369 | ||
2370 | return ret; | |
2371 | } | |
2372 | ||
4ee9c684 | 2373 | /* A simple pass that attempts to fold all builtin functions. This pass |
2374 | is run after we've propagated as many constants as we can. */ | |
2375 | ||
2a1990e9 | 2376 | static unsigned int |
4ee9c684 | 2377 | execute_fold_all_builtins (void) |
2378 | { | |
b36237eb | 2379 | bool cfg_changed = false; |
4ee9c684 | 2380 | basic_block bb; |
b1b7c0c4 | 2381 | unsigned int todoflags = 0; |
48e1416a | 2382 | |
4ee9c684 | 2383 | FOR_EACH_BB (bb) |
2384 | { | |
75a70cf9 | 2385 | gimple_stmt_iterator i; |
2386 | for (i = gsi_start_bb (bb); !gsi_end_p (i); ) | |
4ee9c684 | 2387 | { |
75a70cf9 | 2388 | gimple stmt, old_stmt; |
4ee9c684 | 2389 | tree callee, result; |
0a39fd54 | 2390 | enum built_in_function fcode; |
4ee9c684 | 2391 | |
75a70cf9 | 2392 | stmt = gsi_stmt (i); |
2393 | ||
2394 | if (gimple_code (stmt) != GIMPLE_CALL) | |
0a39fd54 | 2395 | { |
75a70cf9 | 2396 | gsi_next (&i); |
0a39fd54 | 2397 | continue; |
2398 | } | |
75a70cf9 | 2399 | callee = gimple_call_fndecl (stmt); |
4ee9c684 | 2400 | if (!callee || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL) |
0a39fd54 | 2401 | { |
75a70cf9 | 2402 | gsi_next (&i); |
0a39fd54 | 2403 | continue; |
2404 | } | |
2405 | fcode = DECL_FUNCTION_CODE (callee); | |
4ee9c684 | 2406 | |
2d18b16d | 2407 | result = gimple_fold_builtin (stmt); |
5a4b7e1e | 2408 | |
2409 | if (result) | |
75a70cf9 | 2410 | gimple_remove_stmt_histograms (cfun, stmt); |
5a4b7e1e | 2411 | |
4ee9c684 | 2412 | if (!result) |
2413 | switch (DECL_FUNCTION_CODE (callee)) | |
2414 | { | |
2415 | case BUILT_IN_CONSTANT_P: | |
2416 | /* Resolve __builtin_constant_p. If it hasn't been | |
2417 | folded to integer_one_node by now, it's fairly | |
2418 | certain that the value simply isn't constant. */ | |
75a70cf9 | 2419 | result = integer_zero_node; |
4ee9c684 | 2420 | break; |
2421 | ||
fca0886c | 2422 | case BUILT_IN_ASSUME_ALIGNED: |
2423 | /* Remove __builtin_assume_aligned. */ | |
2424 | result = gimple_call_arg (stmt, 0); | |
2425 | break; | |
2426 | ||
bdd0e199 | 2427 | case BUILT_IN_STACK_RESTORE: |
75a70cf9 | 2428 | result = optimize_stack_restore (i); |
8a58ed0a | 2429 | if (result) |
2430 | break; | |
75a70cf9 | 2431 | gsi_next (&i); |
8a58ed0a | 2432 | continue; |
2433 | ||
f87df69a | 2434 | case BUILT_IN_UNREACHABLE: |
2435 | if (optimize_unreachable (i)) | |
2436 | cfg_changed = true; | |
2437 | break; | |
2438 | ||
8a58ed0a | 2439 | case BUILT_IN_VA_START: |
2440 | case BUILT_IN_VA_END: | |
2441 | case BUILT_IN_VA_COPY: | |
2442 | /* These shouldn't be folded before pass_stdarg. */ | |
75a70cf9 | 2443 | result = optimize_stdarg_builtin (stmt); |
bdd0e199 | 2444 | if (result) |
2445 | break; | |
2446 | /* FALLTHRU */ | |
2447 | ||
4ee9c684 | 2448 | default: |
75a70cf9 | 2449 | gsi_next (&i); |
4ee9c684 | 2450 | continue; |
2451 | } | |
2452 | ||
f87df69a | 2453 | if (result == NULL_TREE) |
2454 | break; | |
2455 | ||
4ee9c684 | 2456 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2457 | { | |
2458 | fprintf (dump_file, "Simplified\n "); | |
75a70cf9 | 2459 | print_gimple_stmt (dump_file, stmt, 0, dump_flags); |
4ee9c684 | 2460 | } |
2461 | ||
75a70cf9 | 2462 | old_stmt = stmt; |
75a70cf9 | 2463 | if (!update_call_from_tree (&i, result)) |
0fefde02 | 2464 | { |
2465 | gimplify_and_update_call_from_tree (&i, result); | |
2466 | todoflags |= TODO_update_address_taken; | |
2467 | } | |
de6ed584 | 2468 | |
75a70cf9 | 2469 | stmt = gsi_stmt (i); |
4c5fd53c | 2470 | update_stmt (stmt); |
de6ed584 | 2471 | |
75a70cf9 | 2472 | if (maybe_clean_or_replace_eh_stmt (old_stmt, stmt) |
2473 | && gimple_purge_dead_eh_edges (bb)) | |
b36237eb | 2474 | cfg_changed = true; |
4ee9c684 | 2475 | |
2476 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2477 | { | |
2478 | fprintf (dump_file, "to\n "); | |
75a70cf9 | 2479 | print_gimple_stmt (dump_file, stmt, 0, dump_flags); |
4ee9c684 | 2480 | fprintf (dump_file, "\n"); |
2481 | } | |
0a39fd54 | 2482 | |
2483 | /* Retry the same statement if it changed into another | |
2484 | builtin, there might be new opportunities now. */ | |
75a70cf9 | 2485 | if (gimple_code (stmt) != GIMPLE_CALL) |
0a39fd54 | 2486 | { |
75a70cf9 | 2487 | gsi_next (&i); |
0a39fd54 | 2488 | continue; |
2489 | } | |
75a70cf9 | 2490 | callee = gimple_call_fndecl (stmt); |
0a39fd54 | 2491 | if (!callee |
75a70cf9 | 2492 | || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL |
0a39fd54 | 2493 | || DECL_FUNCTION_CODE (callee) == fcode) |
75a70cf9 | 2494 | gsi_next (&i); |
4ee9c684 | 2495 | } |
2496 | } | |
48e1416a | 2497 | |
b36237eb | 2498 | /* Delete unreachable blocks. */ |
b1b7c0c4 | 2499 | if (cfg_changed) |
2500 | todoflags |= TODO_cleanup_cfg; | |
48e1416a | 2501 | |
b1b7c0c4 | 2502 | return todoflags; |
4ee9c684 | 2503 | } |
2504 | ||
41511585 | 2505 | |
48e1416a | 2506 | struct gimple_opt_pass pass_fold_builtins = |
4ee9c684 | 2507 | { |
20099e35 | 2508 | { |
2509 | GIMPLE_PASS, | |
4ee9c684 | 2510 | "fab", /* name */ |
c7875731 | 2511 | OPTGROUP_NONE, /* optinfo_flags */ |
4ee9c684 | 2512 | NULL, /* gate */ |
2513 | execute_fold_all_builtins, /* execute */ | |
2514 | NULL, /* sub */ | |
2515 | NULL, /* next */ | |
2516 | 0, /* static_pass_number */ | |
0b1615c1 | 2517 | TV_NONE, /* tv_id */ |
49290934 | 2518 | PROP_cfg | PROP_ssa, /* properties_required */ |
4ee9c684 | 2519 | 0, /* properties_provided */ |
2520 | 0, /* properties_destroyed */ | |
2521 | 0, /* todo_flags_start */ | |
771e2890 | 2522 | TODO_verify_ssa |
20099e35 | 2523 | | TODO_update_ssa /* todo_flags_finish */ |
2524 | } | |
4ee9c684 | 2525 | }; |