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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" |
4ee9c684 | 133 | |
134 | ||
135 | /* Possible lattice values. */ | |
136 | typedef enum | |
137 | { | |
bfa30570 | 138 | UNINITIALIZED, |
4ee9c684 | 139 | UNDEFINED, |
140 | CONSTANT, | |
141 | VARYING | |
88dbf20f | 142 | } ccp_lattice_t; |
4ee9c684 | 143 | |
14f101cf | 144 | struct prop_value_d { |
145 | /* Lattice value. */ | |
146 | ccp_lattice_t lattice_val; | |
147 | ||
148 | /* Propagated value. */ | |
149 | tree value; | |
b7e55469 | 150 | |
151 | /* Mask that applies to the propagated value during CCP. For | |
152 | X with a CONSTANT lattice value X & ~mask == value & ~mask. */ | |
153 | double_int mask; | |
14f101cf | 154 | }; |
155 | ||
156 | typedef struct prop_value_d prop_value_t; | |
157 | ||
88dbf20f | 158 | /* Array of propagated constant values. After propagation, |
159 | CONST_VAL[I].VALUE holds the constant value for SSA_NAME(I). If | |
160 | the constant is held in an SSA name representing a memory store | |
4fb5e5ca | 161 | (i.e., a VDEF), CONST_VAL[I].MEM_REF will contain the actual |
162 | memory reference used to store (i.e., the LHS of the assignment | |
163 | doing the store). */ | |
20140406 | 164 | static prop_value_t *const_val; |
4ee9c684 | 165 | |
4af351a8 | 166 | static void canonicalize_float_value (prop_value_t *); |
6688f8ec | 167 | static bool ccp_fold_stmt (gimple_stmt_iterator *); |
4af351a8 | 168 | |
88dbf20f | 169 | /* Dump constant propagation value VAL to file OUTF prefixed by PREFIX. */ |
01406fc0 | 170 | |
171 | static void | |
88dbf20f | 172 | dump_lattice_value (FILE *outf, const char *prefix, prop_value_t val) |
01406fc0 | 173 | { |
41511585 | 174 | switch (val.lattice_val) |
01406fc0 | 175 | { |
88dbf20f | 176 | case UNINITIALIZED: |
177 | fprintf (outf, "%sUNINITIALIZED", prefix); | |
178 | break; | |
41511585 | 179 | case UNDEFINED: |
180 | fprintf (outf, "%sUNDEFINED", prefix); | |
181 | break; | |
182 | case VARYING: | |
183 | fprintf (outf, "%sVARYING", prefix); | |
184 | break; | |
41511585 | 185 | case CONSTANT: |
186 | fprintf (outf, "%sCONSTANT ", prefix); | |
b7e55469 | 187 | if (TREE_CODE (val.value) != INTEGER_CST |
188 | || double_int_zero_p (val.mask)) | |
189 | print_generic_expr (outf, val.value, dump_flags); | |
190 | else | |
191 | { | |
192 | double_int cval = double_int_and_not (tree_to_double_int (val.value), | |
193 | val.mask); | |
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 | { | |
239 | tree sym = SSA_NAME_VAR (var); | |
b7e55469 | 240 | prop_value_t val = { UNINITIALIZED, NULL_TREE, { 0, 0 } }; |
8edeb88b | 241 | gimple stmt; |
242 | ||
243 | stmt = SSA_NAME_DEF_STMT (var); | |
244 | ||
245 | if (gimple_nop_p (stmt)) | |
4ee9c684 | 246 | { |
8edeb88b | 247 | /* Variables defined by an empty statement are those used |
248 | before being initialized. If VAR is a local variable, we | |
249 | can assume initially that it is UNDEFINED, otherwise we must | |
250 | consider it VARYING. */ | |
524a0531 | 251 | if (is_gimple_reg (sym) |
252 | && TREE_CODE (sym) == VAR_DECL) | |
8edeb88b | 253 | val.lattice_val = UNDEFINED; |
254 | else | |
b7e55469 | 255 | { |
256 | val.lattice_val = VARYING; | |
257 | val.mask = double_int_minus_one; | |
258 | } | |
4ee9c684 | 259 | } |
8edeb88b | 260 | else if (is_gimple_assign (stmt) |
261 | /* Value-returning GIMPLE_CALL statements assign to | |
262 | a variable, and are treated similarly to GIMPLE_ASSIGN. */ | |
263 | || (is_gimple_call (stmt) | |
264 | && gimple_call_lhs (stmt) != NULL_TREE) | |
265 | || gimple_code (stmt) == GIMPLE_PHI) | |
41511585 | 266 | { |
8edeb88b | 267 | tree cst; |
268 | if (gimple_assign_single_p (stmt) | |
269 | && DECL_P (gimple_assign_rhs1 (stmt)) | |
270 | && (cst = get_symbol_constant_value (gimple_assign_rhs1 (stmt)))) | |
88dbf20f | 271 | { |
8edeb88b | 272 | val.lattice_val = CONSTANT; |
273 | val.value = cst; | |
88dbf20f | 274 | } |
275 | else | |
8edeb88b | 276 | /* Any other variable defined by an assignment or a PHI node |
277 | is considered UNDEFINED. */ | |
278 | val.lattice_val = UNDEFINED; | |
279 | } | |
280 | else | |
281 | { | |
282 | /* Otherwise, VAR will never take on a constant value. */ | |
283 | val.lattice_val = VARYING; | |
b7e55469 | 284 | val.mask = double_int_minus_one; |
41511585 | 285 | } |
4ee9c684 | 286 | |
41511585 | 287 | return val; |
288 | } | |
4ee9c684 | 289 | |
4ee9c684 | 290 | |
bfa30570 | 291 | /* Get the constant value associated with variable VAR. */ |
4ee9c684 | 292 | |
bfa30570 | 293 | static inline prop_value_t * |
294 | get_value (tree var) | |
88dbf20f | 295 | { |
e004838d | 296 | prop_value_t *val; |
bfa30570 | 297 | |
e004838d | 298 | if (const_val == NULL) |
299 | return NULL; | |
300 | ||
301 | val = &const_val[SSA_NAME_VERSION (var)]; | |
bfa30570 | 302 | if (val->lattice_val == UNINITIALIZED) |
4ee9c684 | 303 | *val = get_default_value (var); |
304 | ||
4af351a8 | 305 | canonicalize_float_value (val); |
306 | ||
4ee9c684 | 307 | return val; |
308 | } | |
309 | ||
15d138c9 | 310 | /* Return the constant tree value associated with VAR. */ |
311 | ||
312 | static inline tree | |
313 | get_constant_value (tree var) | |
314 | { | |
98d92e3c | 315 | prop_value_t *val; |
316 | if (TREE_CODE (var) != SSA_NAME) | |
317 | { | |
318 | if (is_gimple_min_invariant (var)) | |
319 | return var; | |
320 | return NULL_TREE; | |
321 | } | |
322 | val = get_value (var); | |
b7e55469 | 323 | if (val |
324 | && val->lattice_val == CONSTANT | |
325 | && (TREE_CODE (val->value) != INTEGER_CST | |
326 | || double_int_zero_p (val->mask))) | |
15d138c9 | 327 | return val->value; |
328 | return NULL_TREE; | |
329 | } | |
330 | ||
bfa30570 | 331 | /* Sets the value associated with VAR to VARYING. */ |
332 | ||
333 | static inline void | |
334 | set_value_varying (tree var) | |
335 | { | |
336 | prop_value_t *val = &const_val[SSA_NAME_VERSION (var)]; | |
337 | ||
338 | val->lattice_val = VARYING; | |
339 | val->value = NULL_TREE; | |
b7e55469 | 340 | val->mask = double_int_minus_one; |
bfa30570 | 341 | } |
4ee9c684 | 342 | |
b31eb493 | 343 | /* For float types, modify the value of VAL to make ccp work correctly |
344 | for non-standard values (-0, NaN): | |
345 | ||
346 | If HONOR_SIGNED_ZEROS is false, and VAL = -0, we canonicalize it to 0. | |
347 | If HONOR_NANS is false, and VAL is NaN, we canonicalize it to UNDEFINED. | |
348 | This is to fix the following problem (see PR 29921): Suppose we have | |
349 | ||
350 | x = 0.0 * y | |
351 | ||
352 | and we set value of y to NaN. This causes value of x to be set to NaN. | |
353 | When we later determine that y is in fact VARYING, fold uses the fact | |
354 | that HONOR_NANS is false, and we try to change the value of x to 0, | |
355 | causing an ICE. With HONOR_NANS being false, the real appearance of | |
356 | NaN would cause undefined behavior, though, so claiming that y (and x) | |
357 | are UNDEFINED initially is correct. */ | |
358 | ||
359 | static void | |
360 | canonicalize_float_value (prop_value_t *val) | |
361 | { | |
362 | enum machine_mode mode; | |
363 | tree type; | |
364 | REAL_VALUE_TYPE d; | |
365 | ||
366 | if (val->lattice_val != CONSTANT | |
367 | || TREE_CODE (val->value) != REAL_CST) | |
368 | return; | |
369 | ||
370 | d = TREE_REAL_CST (val->value); | |
371 | type = TREE_TYPE (val->value); | |
372 | mode = TYPE_MODE (type); | |
373 | ||
374 | if (!HONOR_SIGNED_ZEROS (mode) | |
375 | && REAL_VALUE_MINUS_ZERO (d)) | |
376 | { | |
377 | val->value = build_real (type, dconst0); | |
378 | return; | |
379 | } | |
380 | ||
381 | if (!HONOR_NANS (mode) | |
382 | && REAL_VALUE_ISNAN (d)) | |
383 | { | |
384 | val->lattice_val = UNDEFINED; | |
385 | val->value = NULL; | |
b31eb493 | 386 | return; |
387 | } | |
388 | } | |
389 | ||
b7e55469 | 390 | /* Return whether the lattice transition is valid. */ |
391 | ||
392 | static bool | |
393 | valid_lattice_transition (prop_value_t old_val, prop_value_t new_val) | |
394 | { | |
395 | /* Lattice transitions must always be monotonically increasing in | |
396 | value. */ | |
397 | if (old_val.lattice_val < new_val.lattice_val) | |
398 | return true; | |
399 | ||
400 | if (old_val.lattice_val != new_val.lattice_val) | |
401 | return false; | |
402 | ||
403 | if (!old_val.value && !new_val.value) | |
404 | return true; | |
405 | ||
406 | /* Now both lattice values are CONSTANT. */ | |
407 | ||
408 | /* Allow transitioning from &x to &x & ~3. */ | |
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) | |
416 | return double_int_equal_p | |
417 | (double_int_and_not (tree_to_double_int (old_val.value), | |
418 | new_val.mask), | |
419 | double_int_and_not (tree_to_double_int (new_val.value), | |
420 | new_val.mask)); | |
421 | ||
422 | /* Otherwise constant values have to agree. */ | |
423 | return operand_equal_p (old_val.value, new_val.value, 0); | |
424 | } | |
425 | ||
88dbf20f | 426 | /* Set the value for variable VAR to NEW_VAL. Return true if the new |
427 | value is different from VAR's previous value. */ | |
4ee9c684 | 428 | |
41511585 | 429 | static bool |
88dbf20f | 430 | set_lattice_value (tree var, prop_value_t new_val) |
4ee9c684 | 431 | { |
6d0bf6d6 | 432 | /* We can deal with old UNINITIALIZED values just fine here. */ |
433 | prop_value_t *old_val = &const_val[SSA_NAME_VERSION (var)]; | |
88dbf20f | 434 | |
b31eb493 | 435 | canonicalize_float_value (&new_val); |
436 | ||
b7e55469 | 437 | /* We have to be careful to not go up the bitwise lattice |
438 | represented by the mask. | |
439 | ??? This doesn't seem to be the best place to enforce this. */ | |
440 | if (new_val.lattice_val == CONSTANT | |
441 | && old_val->lattice_val == CONSTANT | |
442 | && TREE_CODE (new_val.value) == INTEGER_CST | |
443 | && TREE_CODE (old_val->value) == INTEGER_CST) | |
444 | { | |
445 | double_int diff; | |
446 | diff = double_int_xor (tree_to_double_int (new_val.value), | |
447 | tree_to_double_int (old_val->value)); | |
448 | new_val.mask = double_int_ior (new_val.mask, | |
449 | double_int_ior (old_val->mask, diff)); | |
450 | } | |
bfa30570 | 451 | |
b7e55469 | 452 | gcc_assert (valid_lattice_transition (*old_val, new_val)); |
88dbf20f | 453 | |
b7e55469 | 454 | /* If *OLD_VAL and NEW_VAL are the same, return false to inform the |
455 | caller that this was a non-transition. */ | |
456 | if (old_val->lattice_val != new_val.lattice_val | |
457 | || (new_val.lattice_val == CONSTANT | |
458 | && TREE_CODE (new_val.value) == INTEGER_CST | |
459 | && (TREE_CODE (old_val->value) != INTEGER_CST | |
460 | || !double_int_equal_p (new_val.mask, old_val->mask)))) | |
4ee9c684 | 461 | { |
b7e55469 | 462 | /* ??? We would like to delay creation of INTEGER_CSTs from |
463 | partially constants here. */ | |
464 | ||
41511585 | 465 | if (dump_file && (dump_flags & TDF_DETAILS)) |
466 | { | |
88dbf20f | 467 | dump_lattice_value (dump_file, "Lattice value changed to ", new_val); |
bfa30570 | 468 | fprintf (dump_file, ". Adding SSA edges to worklist.\n"); |
41511585 | 469 | } |
470 | ||
88dbf20f | 471 | *old_val = new_val; |
472 | ||
6d0bf6d6 | 473 | gcc_assert (new_val.lattice_val != UNINITIALIZED); |
bfa30570 | 474 | return true; |
4ee9c684 | 475 | } |
41511585 | 476 | |
477 | return false; | |
4ee9c684 | 478 | } |
479 | ||
b7e55469 | 480 | static prop_value_t get_value_for_expr (tree, bool); |
481 | static prop_value_t bit_value_binop (enum tree_code, tree, tree, tree); | |
482 | static void bit_value_binop_1 (enum tree_code, tree, double_int *, double_int *, | |
483 | tree, double_int, double_int, | |
484 | tree, double_int, double_int); | |
485 | ||
486 | /* Return a double_int that can be used for bitwise simplifications | |
487 | from VAL. */ | |
488 | ||
489 | static double_int | |
490 | value_to_double_int (prop_value_t val) | |
491 | { | |
492 | if (val.value | |
493 | && TREE_CODE (val.value) == INTEGER_CST) | |
494 | return tree_to_double_int (val.value); | |
495 | else | |
496 | return double_int_zero; | |
497 | } | |
498 | ||
499 | /* Return the value for the address expression EXPR based on alignment | |
500 | information. */ | |
6d0bf6d6 | 501 | |
502 | static prop_value_t | |
b7e55469 | 503 | get_value_from_alignment (tree expr) |
504 | { | |
f8abb542 | 505 | tree type = TREE_TYPE (expr); |
b7e55469 | 506 | prop_value_t val; |
f8abb542 | 507 | unsigned HOST_WIDE_INT bitpos; |
508 | unsigned int align; | |
b7e55469 | 509 | |
510 | gcc_assert (TREE_CODE (expr) == ADDR_EXPR); | |
511 | ||
ceea063b | 512 | get_object_alignment_1 (TREE_OPERAND (expr, 0), &align, &bitpos); |
f8abb542 | 513 | val.mask |
514 | = double_int_and_not (POINTER_TYPE_P (type) || TYPE_UNSIGNED (type) | |
515 | ? double_int_mask (TYPE_PRECISION (type)) | |
516 | : double_int_minus_one, | |
517 | uhwi_to_double_int (align / BITS_PER_UNIT - 1)); | |
518 | val.lattice_val = double_int_minus_one_p (val.mask) ? VARYING : CONSTANT; | |
519 | if (val.lattice_val == CONSTANT) | |
520 | val.value | |
521 | = double_int_to_tree (type, uhwi_to_double_int (bitpos / BITS_PER_UNIT)); | |
b7e55469 | 522 | else |
f8abb542 | 523 | val.value = NULL_TREE; |
b7e55469 | 524 | |
525 | return val; | |
526 | } | |
527 | ||
528 | /* Return the value for the tree operand EXPR. If FOR_BITS_P is true | |
529 | return constant bits extracted from alignment information for | |
530 | invariant addresses. */ | |
531 | ||
532 | static prop_value_t | |
533 | get_value_for_expr (tree expr, bool for_bits_p) | |
6d0bf6d6 | 534 | { |
535 | prop_value_t val; | |
536 | ||
537 | if (TREE_CODE (expr) == SSA_NAME) | |
b7e55469 | 538 | { |
539 | val = *get_value (expr); | |
540 | if (for_bits_p | |
541 | && val.lattice_val == CONSTANT | |
542 | && TREE_CODE (val.value) == ADDR_EXPR) | |
543 | val = get_value_from_alignment (val.value); | |
544 | } | |
545 | else if (is_gimple_min_invariant (expr) | |
546 | && (!for_bits_p || TREE_CODE (expr) != ADDR_EXPR)) | |
6d0bf6d6 | 547 | { |
548 | val.lattice_val = CONSTANT; | |
549 | val.value = expr; | |
b7e55469 | 550 | val.mask = double_int_zero; |
6d0bf6d6 | 551 | canonicalize_float_value (&val); |
552 | } | |
b7e55469 | 553 | else if (TREE_CODE (expr) == ADDR_EXPR) |
554 | val = get_value_from_alignment (expr); | |
6d0bf6d6 | 555 | else |
556 | { | |
557 | val.lattice_val = VARYING; | |
b7e55469 | 558 | val.mask = double_int_minus_one; |
6d0bf6d6 | 559 | val.value = NULL_TREE; |
560 | } | |
6d0bf6d6 | 561 | return val; |
562 | } | |
563 | ||
88dbf20f | 564 | /* Return the likely CCP lattice value for STMT. |
4ee9c684 | 565 | |
41511585 | 566 | If STMT has no operands, then return CONSTANT. |
4ee9c684 | 567 | |
d61b9af3 | 568 | Else if undefinedness of operands of STMT cause its value to be |
569 | undefined, then return UNDEFINED. | |
4ee9c684 | 570 | |
41511585 | 571 | Else if any operands of STMT are constants, then return CONSTANT. |
4ee9c684 | 572 | |
41511585 | 573 | Else return VARYING. */ |
4ee9c684 | 574 | |
88dbf20f | 575 | static ccp_lattice_t |
75a70cf9 | 576 | likely_value (gimple stmt) |
41511585 | 577 | { |
d61b9af3 | 578 | bool has_constant_operand, has_undefined_operand, all_undefined_operands; |
41511585 | 579 | tree use; |
580 | ssa_op_iter iter; | |
8edeb88b | 581 | unsigned i; |
4ee9c684 | 582 | |
590c3166 | 583 | enum gimple_code code = gimple_code (stmt); |
75a70cf9 | 584 | |
585 | /* This function appears to be called only for assignments, calls, | |
586 | conditionals, and switches, due to the logic in visit_stmt. */ | |
587 | gcc_assert (code == GIMPLE_ASSIGN | |
588 | || code == GIMPLE_CALL | |
589 | || code == GIMPLE_COND | |
590 | || code == GIMPLE_SWITCH); | |
88dbf20f | 591 | |
592 | /* If the statement has volatile operands, it won't fold to a | |
593 | constant value. */ | |
75a70cf9 | 594 | if (gimple_has_volatile_ops (stmt)) |
88dbf20f | 595 | return VARYING; |
596 | ||
75a70cf9 | 597 | /* Arrive here for more complex cases. */ |
bfa30570 | 598 | has_constant_operand = false; |
d61b9af3 | 599 | has_undefined_operand = false; |
600 | all_undefined_operands = true; | |
8edeb88b | 601 | FOR_EACH_SSA_TREE_OPERAND (use, stmt, iter, SSA_OP_USE) |
41511585 | 602 | { |
bfa30570 | 603 | prop_value_t *val = get_value (use); |
41511585 | 604 | |
bfa30570 | 605 | if (val->lattice_val == UNDEFINED) |
d61b9af3 | 606 | has_undefined_operand = true; |
607 | else | |
608 | all_undefined_operands = false; | |
88dbf20f | 609 | |
41511585 | 610 | if (val->lattice_val == CONSTANT) |
bfa30570 | 611 | has_constant_operand = true; |
4ee9c684 | 612 | } |
41511585 | 613 | |
dd277d48 | 614 | /* There may be constants in regular rhs operands. For calls we |
615 | have to ignore lhs, fndecl and static chain, otherwise only | |
616 | the lhs. */ | |
617 | for (i = (is_gimple_call (stmt) ? 2 : 0) + gimple_has_lhs (stmt); | |
8edeb88b | 618 | i < gimple_num_ops (stmt); ++i) |
619 | { | |
620 | tree op = gimple_op (stmt, i); | |
621 | if (!op || TREE_CODE (op) == SSA_NAME) | |
622 | continue; | |
623 | if (is_gimple_min_invariant (op)) | |
624 | has_constant_operand = true; | |
625 | } | |
626 | ||
87c0a9fc | 627 | if (has_constant_operand) |
628 | all_undefined_operands = false; | |
629 | ||
d61b9af3 | 630 | /* If the operation combines operands like COMPLEX_EXPR make sure to |
631 | not mark the result UNDEFINED if only one part of the result is | |
632 | undefined. */ | |
75a70cf9 | 633 | if (has_undefined_operand && all_undefined_operands) |
d61b9af3 | 634 | return UNDEFINED; |
75a70cf9 | 635 | else if (code == GIMPLE_ASSIGN && has_undefined_operand) |
d61b9af3 | 636 | { |
75a70cf9 | 637 | switch (gimple_assign_rhs_code (stmt)) |
d61b9af3 | 638 | { |
639 | /* Unary operators are handled with all_undefined_operands. */ | |
640 | case PLUS_EXPR: | |
641 | case MINUS_EXPR: | |
d61b9af3 | 642 | case POINTER_PLUS_EXPR: |
d61b9af3 | 643 | /* Not MIN_EXPR, MAX_EXPR. One VARYING operand may be selected. |
644 | Not bitwise operators, one VARYING operand may specify the | |
645 | result completely. Not logical operators for the same reason. | |
05a936a0 | 646 | Not COMPLEX_EXPR as one VARYING operand makes the result partly |
647 | not UNDEFINED. Not *DIV_EXPR, comparisons and shifts because | |
648 | the undefined operand may be promoted. */ | |
d61b9af3 | 649 | return UNDEFINED; |
650 | ||
651 | default: | |
652 | ; | |
653 | } | |
654 | } | |
655 | /* If there was an UNDEFINED operand but the result may be not UNDEFINED | |
c91fedc5 | 656 | fall back to CONSTANT. During iteration UNDEFINED may still drop |
657 | to CONSTANT. */ | |
d61b9af3 | 658 | if (has_undefined_operand) |
c91fedc5 | 659 | return CONSTANT; |
d61b9af3 | 660 | |
8edeb88b | 661 | /* We do not consider virtual operands here -- load from read-only |
662 | memory may have only VARYING virtual operands, but still be | |
663 | constant. */ | |
bfa30570 | 664 | if (has_constant_operand |
8edeb88b | 665 | || gimple_references_memory_p (stmt)) |
88dbf20f | 666 | return CONSTANT; |
667 | ||
bfa30570 | 668 | return VARYING; |
4ee9c684 | 669 | } |
670 | ||
bfa30570 | 671 | /* Returns true if STMT cannot be constant. */ |
672 | ||
673 | static bool | |
75a70cf9 | 674 | surely_varying_stmt_p (gimple stmt) |
bfa30570 | 675 | { |
676 | /* If the statement has operands that we cannot handle, it cannot be | |
677 | constant. */ | |
75a70cf9 | 678 | if (gimple_has_volatile_ops (stmt)) |
bfa30570 | 679 | return true; |
680 | ||
f257af64 | 681 | /* If it is a call and does not return a value or is not a |
682 | builtin and not an indirect call, it is varying. */ | |
75a70cf9 | 683 | if (is_gimple_call (stmt)) |
f257af64 | 684 | { |
685 | tree fndecl; | |
686 | if (!gimple_call_lhs (stmt) | |
687 | || ((fndecl = gimple_call_fndecl (stmt)) != NULL_TREE | |
5768aeb3 | 688 | && !DECL_BUILT_IN (fndecl))) |
f257af64 | 689 | return true; |
690 | } | |
bfa30570 | 691 | |
8edeb88b | 692 | /* Any other store operation is not interesting. */ |
dd277d48 | 693 | else if (gimple_vdef (stmt)) |
8edeb88b | 694 | return true; |
695 | ||
bfa30570 | 696 | /* Anything other than assignments and conditional jumps are not |
697 | interesting for CCP. */ | |
75a70cf9 | 698 | if (gimple_code (stmt) != GIMPLE_ASSIGN |
f257af64 | 699 | && gimple_code (stmt) != GIMPLE_COND |
700 | && gimple_code (stmt) != GIMPLE_SWITCH | |
701 | && gimple_code (stmt) != GIMPLE_CALL) | |
bfa30570 | 702 | return true; |
703 | ||
704 | return false; | |
705 | } | |
4ee9c684 | 706 | |
41511585 | 707 | /* Initialize local data structures for CCP. */ |
4ee9c684 | 708 | |
709 | static void | |
41511585 | 710 | ccp_initialize (void) |
4ee9c684 | 711 | { |
41511585 | 712 | basic_block bb; |
4ee9c684 | 713 | |
43959b95 | 714 | const_val = XCNEWVEC (prop_value_t, num_ssa_names); |
4ee9c684 | 715 | |
41511585 | 716 | /* Initialize simulation flags for PHI nodes and statements. */ |
717 | FOR_EACH_BB (bb) | |
4ee9c684 | 718 | { |
75a70cf9 | 719 | gimple_stmt_iterator i; |
4ee9c684 | 720 | |
75a70cf9 | 721 | for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i)) |
41511585 | 722 | { |
75a70cf9 | 723 | gimple stmt = gsi_stmt (i); |
2193544e | 724 | bool is_varying; |
725 | ||
726 | /* If the statement is a control insn, then we do not | |
727 | want to avoid simulating the statement once. Failure | |
728 | to do so means that those edges will never get added. */ | |
729 | if (stmt_ends_bb_p (stmt)) | |
730 | is_varying = false; | |
731 | else | |
732 | is_varying = surely_varying_stmt_p (stmt); | |
4ee9c684 | 733 | |
bfa30570 | 734 | if (is_varying) |
41511585 | 735 | { |
88dbf20f | 736 | tree def; |
737 | ssa_op_iter iter; | |
738 | ||
739 | /* If the statement will not produce a constant, mark | |
740 | all its outputs VARYING. */ | |
741 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS) | |
8edeb88b | 742 | set_value_varying (def); |
41511585 | 743 | } |
75a70cf9 | 744 | prop_set_simulate_again (stmt, !is_varying); |
41511585 | 745 | } |
4ee9c684 | 746 | } |
747 | ||
75a70cf9 | 748 | /* Now process PHI nodes. We never clear the simulate_again flag on |
749 | phi nodes, since we do not know which edges are executable yet, | |
750 | except for phi nodes for virtual operands when we do not do store ccp. */ | |
41511585 | 751 | FOR_EACH_BB (bb) |
4ee9c684 | 752 | { |
75a70cf9 | 753 | gimple_stmt_iterator i; |
41511585 | 754 | |
75a70cf9 | 755 | for (i = gsi_start_phis (bb); !gsi_end_p (i); gsi_next (&i)) |
756 | { | |
757 | gimple phi = gsi_stmt (i); | |
758 | ||
61207d43 | 759 | if (!is_gimple_reg (gimple_phi_result (phi))) |
75a70cf9 | 760 | prop_set_simulate_again (phi, false); |
bfa30570 | 761 | else |
75a70cf9 | 762 | prop_set_simulate_again (phi, true); |
41511585 | 763 | } |
4ee9c684 | 764 | } |
41511585 | 765 | } |
4ee9c684 | 766 | |
43fb76c1 | 767 | /* Debug count support. Reset the values of ssa names |
768 | VARYING when the total number ssa names analyzed is | |
769 | beyond the debug count specified. */ | |
770 | ||
771 | static void | |
772 | do_dbg_cnt (void) | |
773 | { | |
774 | unsigned i; | |
775 | for (i = 0; i < num_ssa_names; i++) | |
776 | { | |
777 | if (!dbg_cnt (ccp)) | |
778 | { | |
779 | const_val[i].lattice_val = VARYING; | |
b7e55469 | 780 | const_val[i].mask = double_int_minus_one; |
43fb76c1 | 781 | const_val[i].value = NULL_TREE; |
782 | } | |
783 | } | |
784 | } | |
785 | ||
4ee9c684 | 786 | |
88dbf20f | 787 | /* Do final substitution of propagated values, cleanup the flowgraph and |
48e1416a | 788 | free allocated storage. |
4ee9c684 | 789 | |
33a34f1e | 790 | Return TRUE when something was optimized. */ |
791 | ||
792 | static bool | |
88dbf20f | 793 | ccp_finalize (void) |
4ee9c684 | 794 | { |
43fb76c1 | 795 | bool something_changed; |
153c3b50 | 796 | unsigned i; |
43fb76c1 | 797 | |
798 | do_dbg_cnt (); | |
153c3b50 | 799 | |
800 | /* Derive alignment and misalignment information from partially | |
801 | constant pointers in the lattice. */ | |
802 | for (i = 1; i < num_ssa_names; ++i) | |
803 | { | |
804 | tree name = ssa_name (i); | |
805 | prop_value_t *val; | |
153c3b50 | 806 | unsigned int tem, align; |
807 | ||
808 | if (!name | |
809 | || !POINTER_TYPE_P (TREE_TYPE (name))) | |
810 | continue; | |
811 | ||
812 | val = get_value (name); | |
813 | if (val->lattice_val != CONSTANT | |
814 | || TREE_CODE (val->value) != INTEGER_CST) | |
815 | continue; | |
816 | ||
817 | /* Trailing constant bits specify the alignment, trailing value | |
818 | bits the misalignment. */ | |
819 | tem = val->mask.low; | |
820 | align = (tem & -tem); | |
ceea063b | 821 | if (align > 1) |
822 | set_ptr_info_alignment (get_ptr_info (name), align, | |
823 | TREE_INT_CST_LOW (val->value) & (align - 1)); | |
153c3b50 | 824 | } |
825 | ||
88dbf20f | 826 | /* Perform substitutions based on the known constant values. */ |
14f101cf | 827 | something_changed = substitute_and_fold (get_constant_value, |
828 | ccp_fold_stmt, true); | |
4ee9c684 | 829 | |
88dbf20f | 830 | free (const_val); |
e004838d | 831 | const_val = NULL; |
33a34f1e | 832 | return something_changed;; |
4ee9c684 | 833 | } |
834 | ||
835 | ||
88dbf20f | 836 | /* Compute the meet operator between *VAL1 and *VAL2. Store the result |
837 | in VAL1. | |
838 | ||
839 | any M UNDEFINED = any | |
88dbf20f | 840 | any M VARYING = VARYING |
841 | Ci M Cj = Ci if (i == j) | |
842 | Ci M Cj = VARYING if (i != j) | |
bfa30570 | 843 | */ |
4ee9c684 | 844 | |
845 | static void | |
88dbf20f | 846 | ccp_lattice_meet (prop_value_t *val1, prop_value_t *val2) |
4ee9c684 | 847 | { |
88dbf20f | 848 | if (val1->lattice_val == UNDEFINED) |
4ee9c684 | 849 | { |
88dbf20f | 850 | /* UNDEFINED M any = any */ |
851 | *val1 = *val2; | |
41511585 | 852 | } |
88dbf20f | 853 | else if (val2->lattice_val == UNDEFINED) |
92481a4d | 854 | { |
88dbf20f | 855 | /* any M UNDEFINED = any |
856 | Nothing to do. VAL1 already contains the value we want. */ | |
857 | ; | |
92481a4d | 858 | } |
88dbf20f | 859 | else if (val1->lattice_val == VARYING |
860 | || val2->lattice_val == VARYING) | |
41511585 | 861 | { |
88dbf20f | 862 | /* any M VARYING = VARYING. */ |
863 | val1->lattice_val = VARYING; | |
b7e55469 | 864 | val1->mask = double_int_minus_one; |
88dbf20f | 865 | val1->value = NULL_TREE; |
41511585 | 866 | } |
b7e55469 | 867 | else if (val1->lattice_val == CONSTANT |
868 | && val2->lattice_val == CONSTANT | |
869 | && TREE_CODE (val1->value) == INTEGER_CST | |
870 | && TREE_CODE (val2->value) == INTEGER_CST) | |
871 | { | |
872 | /* Ci M Cj = Ci if (i == j) | |
873 | Ci M Cj = VARYING if (i != j) | |
874 | ||
875 | For INTEGER_CSTs mask unequal bits. If no equal bits remain, | |
876 | drop to varying. */ | |
877 | val1->mask | |
878 | = double_int_ior (double_int_ior (val1->mask, | |
879 | val2->mask), | |
880 | double_int_xor (tree_to_double_int (val1->value), | |
881 | tree_to_double_int (val2->value))); | |
882 | if (double_int_minus_one_p (val1->mask)) | |
883 | { | |
884 | val1->lattice_val = VARYING; | |
885 | val1->value = NULL_TREE; | |
886 | } | |
887 | } | |
88dbf20f | 888 | else if (val1->lattice_val == CONSTANT |
889 | && val2->lattice_val == CONSTANT | |
61207d43 | 890 | && simple_cst_equal (val1->value, val2->value) == 1) |
41511585 | 891 | { |
88dbf20f | 892 | /* Ci M Cj = Ci if (i == j) |
893 | Ci M Cj = VARYING if (i != j) | |
894 | ||
b7e55469 | 895 | VAL1 already contains the value we want for equivalent values. */ |
896 | } | |
897 | else if (val1->lattice_val == CONSTANT | |
898 | && val2->lattice_val == CONSTANT | |
899 | && (TREE_CODE (val1->value) == ADDR_EXPR | |
900 | || TREE_CODE (val2->value) == ADDR_EXPR)) | |
901 | { | |
902 | /* When not equal addresses are involved try meeting for | |
903 | alignment. */ | |
904 | prop_value_t tem = *val2; | |
905 | if (TREE_CODE (val1->value) == ADDR_EXPR) | |
906 | *val1 = get_value_for_expr (val1->value, true); | |
907 | if (TREE_CODE (val2->value) == ADDR_EXPR) | |
908 | tem = get_value_for_expr (val2->value, true); | |
909 | ccp_lattice_meet (val1, &tem); | |
41511585 | 910 | } |
911 | else | |
912 | { | |
88dbf20f | 913 | /* Any other combination is VARYING. */ |
914 | val1->lattice_val = VARYING; | |
b7e55469 | 915 | val1->mask = double_int_minus_one; |
88dbf20f | 916 | val1->value = NULL_TREE; |
41511585 | 917 | } |
4ee9c684 | 918 | } |
919 | ||
920 | ||
41511585 | 921 | /* Loop through the PHI_NODE's parameters for BLOCK and compare their |
922 | lattice values to determine PHI_NODE's lattice value. The value of a | |
88dbf20f | 923 | PHI node is determined calling ccp_lattice_meet with all the arguments |
41511585 | 924 | of the PHI node that are incoming via executable edges. */ |
4ee9c684 | 925 | |
41511585 | 926 | static enum ssa_prop_result |
75a70cf9 | 927 | ccp_visit_phi_node (gimple phi) |
4ee9c684 | 928 | { |
75a70cf9 | 929 | unsigned i; |
88dbf20f | 930 | prop_value_t *old_val, new_val; |
4ee9c684 | 931 | |
41511585 | 932 | if (dump_file && (dump_flags & TDF_DETAILS)) |
4ee9c684 | 933 | { |
41511585 | 934 | fprintf (dump_file, "\nVisiting PHI node: "); |
75a70cf9 | 935 | print_gimple_stmt (dump_file, phi, 0, dump_flags); |
4ee9c684 | 936 | } |
4ee9c684 | 937 | |
75a70cf9 | 938 | old_val = get_value (gimple_phi_result (phi)); |
41511585 | 939 | switch (old_val->lattice_val) |
940 | { | |
941 | case VARYING: | |
88dbf20f | 942 | return SSA_PROP_VARYING; |
4ee9c684 | 943 | |
41511585 | 944 | case CONSTANT: |
945 | new_val = *old_val; | |
946 | break; | |
4ee9c684 | 947 | |
41511585 | 948 | case UNDEFINED: |
41511585 | 949 | new_val.lattice_val = UNDEFINED; |
88dbf20f | 950 | new_val.value = NULL_TREE; |
41511585 | 951 | break; |
4ee9c684 | 952 | |
41511585 | 953 | default: |
8c0963c4 | 954 | gcc_unreachable (); |
41511585 | 955 | } |
4ee9c684 | 956 | |
75a70cf9 | 957 | for (i = 0; i < gimple_phi_num_args (phi); i++) |
41511585 | 958 | { |
88dbf20f | 959 | /* Compute the meet operator over all the PHI arguments flowing |
960 | through executable edges. */ | |
75a70cf9 | 961 | edge e = gimple_phi_arg_edge (phi, i); |
4ee9c684 | 962 | |
41511585 | 963 | if (dump_file && (dump_flags & TDF_DETAILS)) |
964 | { | |
965 | fprintf (dump_file, | |
966 | "\n Argument #%d (%d -> %d %sexecutable)\n", | |
967 | i, e->src->index, e->dest->index, | |
968 | (e->flags & EDGE_EXECUTABLE) ? "" : "not "); | |
969 | } | |
970 | ||
971 | /* If the incoming edge is executable, Compute the meet operator for | |
972 | the existing value of the PHI node and the current PHI argument. */ | |
973 | if (e->flags & EDGE_EXECUTABLE) | |
974 | { | |
75a70cf9 | 975 | tree arg = gimple_phi_arg (phi, i)->def; |
b7e55469 | 976 | prop_value_t arg_val = get_value_for_expr (arg, false); |
4ee9c684 | 977 | |
88dbf20f | 978 | ccp_lattice_meet (&new_val, &arg_val); |
4ee9c684 | 979 | |
41511585 | 980 | if (dump_file && (dump_flags & TDF_DETAILS)) |
981 | { | |
982 | fprintf (dump_file, "\t"); | |
88dbf20f | 983 | print_generic_expr (dump_file, arg, dump_flags); |
984 | dump_lattice_value (dump_file, "\tValue: ", arg_val); | |
41511585 | 985 | fprintf (dump_file, "\n"); |
986 | } | |
4ee9c684 | 987 | |
41511585 | 988 | if (new_val.lattice_val == VARYING) |
989 | break; | |
990 | } | |
991 | } | |
4ee9c684 | 992 | |
993 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
41511585 | 994 | { |
995 | dump_lattice_value (dump_file, "\n PHI node value: ", new_val); | |
996 | fprintf (dump_file, "\n\n"); | |
997 | } | |
998 | ||
bfa30570 | 999 | /* Make the transition to the new value. */ |
75a70cf9 | 1000 | if (set_lattice_value (gimple_phi_result (phi), new_val)) |
41511585 | 1001 | { |
1002 | if (new_val.lattice_val == VARYING) | |
1003 | return SSA_PROP_VARYING; | |
1004 | else | |
1005 | return SSA_PROP_INTERESTING; | |
1006 | } | |
1007 | else | |
1008 | return SSA_PROP_NOT_INTERESTING; | |
4ee9c684 | 1009 | } |
1010 | ||
15d138c9 | 1011 | /* Return the constant value for OP or OP otherwise. */ |
00f4f705 | 1012 | |
1013 | static tree | |
15d138c9 | 1014 | valueize_op (tree op) |
00f4f705 | 1015 | { |
00f4f705 | 1016 | if (TREE_CODE (op) == SSA_NAME) |
1017 | { | |
15d138c9 | 1018 | tree tem = get_constant_value (op); |
1019 | if (tem) | |
1020 | return tem; | |
00f4f705 | 1021 | } |
1022 | return op; | |
1023 | } | |
1024 | ||
41511585 | 1025 | /* CCP specific front-end to the non-destructive constant folding |
1026 | routines. | |
4ee9c684 | 1027 | |
1028 | Attempt to simplify the RHS of STMT knowing that one or more | |
1029 | operands are constants. | |
1030 | ||
1031 | If simplification is possible, return the simplified RHS, | |
75a70cf9 | 1032 | otherwise return the original RHS or NULL_TREE. */ |
4ee9c684 | 1033 | |
1034 | static tree | |
75a70cf9 | 1035 | ccp_fold (gimple stmt) |
4ee9c684 | 1036 | { |
389dd41b | 1037 | location_t loc = gimple_location (stmt); |
75a70cf9 | 1038 | switch (gimple_code (stmt)) |
88dbf20f | 1039 | { |
75a70cf9 | 1040 | case GIMPLE_COND: |
1041 | { | |
1042 | /* Handle comparison operators that can appear in GIMPLE form. */ | |
15d138c9 | 1043 | tree op0 = valueize_op (gimple_cond_lhs (stmt)); |
1044 | tree op1 = valueize_op (gimple_cond_rhs (stmt)); | |
75a70cf9 | 1045 | enum tree_code code = gimple_cond_code (stmt); |
389dd41b | 1046 | return fold_binary_loc (loc, code, boolean_type_node, op0, op1); |
75a70cf9 | 1047 | } |
4ee9c684 | 1048 | |
75a70cf9 | 1049 | case GIMPLE_SWITCH: |
1050 | { | |
15d138c9 | 1051 | /* Return the constant switch index. */ |
1052 | return valueize_op (gimple_switch_index (stmt)); | |
75a70cf9 | 1053 | } |
912f109f | 1054 | |
1d0b727d | 1055 | case GIMPLE_ASSIGN: |
1056 | case GIMPLE_CALL: | |
1057 | return gimple_fold_stmt_to_constant_1 (stmt, valueize_op); | |
04236c3a | 1058 | |
8782adcf | 1059 | default: |
1d0b727d | 1060 | gcc_unreachable (); |
8782adcf | 1061 | } |
8782adcf | 1062 | } |
75a70cf9 | 1063 | |
b7e55469 | 1064 | /* Apply the operation CODE in type TYPE to the value, mask pair |
1065 | RVAL and RMASK representing a value of type RTYPE and set | |
1066 | the value, mask pair *VAL and *MASK to the result. */ | |
1067 | ||
1068 | static void | |
1069 | bit_value_unop_1 (enum tree_code code, tree type, | |
1070 | double_int *val, double_int *mask, | |
1071 | tree rtype, double_int rval, double_int rmask) | |
1072 | { | |
1073 | switch (code) | |
1074 | { | |
1075 | case BIT_NOT_EXPR: | |
1076 | *mask = rmask; | |
1077 | *val = double_int_not (rval); | |
1078 | break; | |
1079 | ||
1080 | case NEGATE_EXPR: | |
1081 | { | |
1082 | double_int temv, temm; | |
1083 | /* Return ~rval + 1. */ | |
1084 | bit_value_unop_1 (BIT_NOT_EXPR, type, &temv, &temm, type, rval, rmask); | |
1085 | bit_value_binop_1 (PLUS_EXPR, type, val, mask, | |
1086 | type, temv, temm, | |
1087 | type, double_int_one, double_int_zero); | |
1088 | break; | |
1089 | } | |
1090 | ||
1091 | CASE_CONVERT: | |
1092 | { | |
1093 | bool uns; | |
1094 | ||
1095 | /* First extend mask and value according to the original type. */ | |
85d86b55 | 1096 | uns = TYPE_UNSIGNED (rtype); |
b7e55469 | 1097 | *mask = double_int_ext (rmask, TYPE_PRECISION (rtype), uns); |
1098 | *val = double_int_ext (rval, TYPE_PRECISION (rtype), uns); | |
1099 | ||
1100 | /* Then extend mask and value according to the target type. */ | |
85d86b55 | 1101 | uns = TYPE_UNSIGNED (type); |
b7e55469 | 1102 | *mask = double_int_ext (*mask, TYPE_PRECISION (type), uns); |
1103 | *val = double_int_ext (*val, TYPE_PRECISION (type), uns); | |
1104 | break; | |
1105 | } | |
1106 | ||
1107 | default: | |
1108 | *mask = double_int_minus_one; | |
1109 | break; | |
1110 | } | |
1111 | } | |
1112 | ||
1113 | /* Apply the operation CODE in type TYPE to the value, mask pairs | |
1114 | R1VAL, R1MASK and R2VAL, R2MASK representing a values of type R1TYPE | |
1115 | and R2TYPE and set the value, mask pair *VAL and *MASK to the result. */ | |
1116 | ||
1117 | static void | |
1118 | bit_value_binop_1 (enum tree_code code, tree type, | |
1119 | double_int *val, double_int *mask, | |
1120 | tree r1type, double_int r1val, double_int r1mask, | |
1121 | tree r2type, double_int r2val, double_int r2mask) | |
1122 | { | |
85d86b55 | 1123 | bool uns = TYPE_UNSIGNED (type); |
b7e55469 | 1124 | /* Assume we'll get a constant result. Use an initial varying value, |
1125 | we fall back to varying in the end if necessary. */ | |
1126 | *mask = double_int_minus_one; | |
1127 | switch (code) | |
1128 | { | |
1129 | case BIT_AND_EXPR: | |
1130 | /* The mask is constant where there is a known not | |
1131 | set bit, (m1 | m2) & ((v1 | m1) & (v2 | m2)) */ | |
1132 | *mask = double_int_and (double_int_ior (r1mask, r2mask), | |
1133 | double_int_and (double_int_ior (r1val, r1mask), | |
1134 | double_int_ior (r2val, r2mask))); | |
1135 | *val = double_int_and (r1val, r2val); | |
1136 | break; | |
1137 | ||
1138 | case BIT_IOR_EXPR: | |
1139 | /* The mask is constant where there is a known | |
1140 | set bit, (m1 | m2) & ~((v1 & ~m1) | (v2 & ~m2)). */ | |
1141 | *mask = double_int_and_not | |
1142 | (double_int_ior (r1mask, r2mask), | |
1143 | double_int_ior (double_int_and_not (r1val, r1mask), | |
1144 | double_int_and_not (r2val, r2mask))); | |
1145 | *val = double_int_ior (r1val, r2val); | |
1146 | break; | |
1147 | ||
1148 | case BIT_XOR_EXPR: | |
1149 | /* m1 | m2 */ | |
1150 | *mask = double_int_ior (r1mask, r2mask); | |
1151 | *val = double_int_xor (r1val, r2val); | |
1152 | break; | |
1153 | ||
1154 | case LROTATE_EXPR: | |
1155 | case RROTATE_EXPR: | |
1156 | if (double_int_zero_p (r2mask)) | |
1157 | { | |
1158 | HOST_WIDE_INT shift = r2val.low; | |
1159 | if (code == RROTATE_EXPR) | |
1160 | shift = -shift; | |
1161 | *mask = double_int_lrotate (r1mask, shift, TYPE_PRECISION (type)); | |
1162 | *val = double_int_lrotate (r1val, shift, TYPE_PRECISION (type)); | |
1163 | } | |
1164 | break; | |
1165 | ||
1166 | case LSHIFT_EXPR: | |
1167 | case RSHIFT_EXPR: | |
1168 | /* ??? We can handle partially known shift counts if we know | |
1169 | its sign. That way we can tell that (x << (y | 8)) & 255 | |
1170 | is zero. */ | |
1171 | if (double_int_zero_p (r2mask)) | |
1172 | { | |
1173 | HOST_WIDE_INT shift = r2val.low; | |
1174 | if (code == RSHIFT_EXPR) | |
1175 | shift = -shift; | |
1176 | /* We need to know if we are doing a left or a right shift | |
1177 | to properly shift in zeros for left shift and unsigned | |
1178 | right shifts and the sign bit for signed right shifts. | |
1179 | For signed right shifts we shift in varying in case | |
1180 | the sign bit was varying. */ | |
1181 | if (shift > 0) | |
1182 | { | |
1183 | *mask = double_int_lshift (r1mask, shift, | |
1184 | TYPE_PRECISION (type), false); | |
1185 | *val = double_int_lshift (r1val, shift, | |
1186 | TYPE_PRECISION (type), false); | |
1187 | } | |
1188 | else if (shift < 0) | |
1189 | { | |
1190 | shift = -shift; | |
1191 | *mask = double_int_rshift (r1mask, shift, | |
1192 | TYPE_PRECISION (type), !uns); | |
1193 | *val = double_int_rshift (r1val, shift, | |
1194 | TYPE_PRECISION (type), !uns); | |
1195 | } | |
1196 | else | |
1197 | { | |
1198 | *mask = r1mask; | |
1199 | *val = r1val; | |
1200 | } | |
1201 | } | |
1202 | break; | |
1203 | ||
1204 | case PLUS_EXPR: | |
1205 | case POINTER_PLUS_EXPR: | |
1206 | { | |
1207 | double_int lo, hi; | |
1208 | /* Do the addition with unknown bits set to zero, to give carry-ins of | |
1209 | zero wherever possible. */ | |
1210 | lo = double_int_add (double_int_and_not (r1val, r1mask), | |
1211 | double_int_and_not (r2val, r2mask)); | |
1212 | lo = double_int_ext (lo, TYPE_PRECISION (type), uns); | |
1213 | /* Do the addition with unknown bits set to one, to give carry-ins of | |
1214 | one wherever possible. */ | |
1215 | hi = double_int_add (double_int_ior (r1val, r1mask), | |
1216 | double_int_ior (r2val, r2mask)); | |
1217 | hi = double_int_ext (hi, TYPE_PRECISION (type), uns); | |
1218 | /* Each bit in the result is known if (a) the corresponding bits in | |
1219 | both inputs are known, and (b) the carry-in to that bit position | |
1220 | is known. We can check condition (b) by seeing if we got the same | |
1221 | result with minimised carries as with maximised carries. */ | |
1222 | *mask = double_int_ior (double_int_ior (r1mask, r2mask), | |
1223 | double_int_xor (lo, hi)); | |
1224 | *mask = double_int_ext (*mask, TYPE_PRECISION (type), uns); | |
1225 | /* It shouldn't matter whether we choose lo or hi here. */ | |
1226 | *val = lo; | |
1227 | break; | |
1228 | } | |
1229 | ||
1230 | case MINUS_EXPR: | |
1231 | { | |
1232 | double_int temv, temm; | |
1233 | bit_value_unop_1 (NEGATE_EXPR, r2type, &temv, &temm, | |
1234 | r2type, r2val, r2mask); | |
1235 | bit_value_binop_1 (PLUS_EXPR, type, val, mask, | |
1236 | r1type, r1val, r1mask, | |
1237 | r2type, temv, temm); | |
1238 | break; | |
1239 | } | |
1240 | ||
1241 | case MULT_EXPR: | |
1242 | { | |
1243 | /* Just track trailing zeros in both operands and transfer | |
1244 | them to the other. */ | |
1245 | int r1tz = double_int_ctz (double_int_ior (r1val, r1mask)); | |
1246 | int r2tz = double_int_ctz (double_int_ior (r2val, r2mask)); | |
1247 | if (r1tz + r2tz >= HOST_BITS_PER_DOUBLE_INT) | |
1248 | { | |
1249 | *mask = double_int_zero; | |
1250 | *val = double_int_zero; | |
1251 | } | |
1252 | else if (r1tz + r2tz > 0) | |
1253 | { | |
1254 | *mask = double_int_not (double_int_mask (r1tz + r2tz)); | |
1255 | *mask = double_int_ext (*mask, TYPE_PRECISION (type), uns); | |
1256 | *val = double_int_zero; | |
1257 | } | |
1258 | break; | |
1259 | } | |
1260 | ||
1261 | case EQ_EXPR: | |
1262 | case NE_EXPR: | |
1263 | { | |
1264 | double_int m = double_int_ior (r1mask, r2mask); | |
1265 | if (!double_int_equal_p (double_int_and_not (r1val, m), | |
1266 | double_int_and_not (r2val, m))) | |
1267 | { | |
1268 | *mask = double_int_zero; | |
1269 | *val = ((code == EQ_EXPR) ? double_int_zero : double_int_one); | |
1270 | } | |
1271 | else | |
1272 | { | |
1273 | /* We know the result of a comparison is always one or zero. */ | |
1274 | *mask = double_int_one; | |
1275 | *val = double_int_zero; | |
1276 | } | |
1277 | break; | |
1278 | } | |
1279 | ||
1280 | case GE_EXPR: | |
1281 | case GT_EXPR: | |
1282 | { | |
1283 | double_int tem = r1val; | |
1284 | r1val = r2val; | |
1285 | r2val = tem; | |
1286 | tem = r1mask; | |
1287 | r1mask = r2mask; | |
1288 | r2mask = tem; | |
1289 | code = swap_tree_comparison (code); | |
1290 | } | |
1291 | /* Fallthru. */ | |
1292 | case LT_EXPR: | |
1293 | case LE_EXPR: | |
1294 | { | |
1295 | int minmax, maxmin; | |
1296 | /* If the most significant bits are not known we know nothing. */ | |
1297 | if (double_int_negative_p (r1mask) || double_int_negative_p (r2mask)) | |
1298 | break; | |
1299 | ||
90c0f5b7 | 1300 | /* For comparisons the signedness is in the comparison operands. */ |
85d86b55 | 1301 | uns = TYPE_UNSIGNED (r1type); |
90c0f5b7 | 1302 | |
b7e55469 | 1303 | /* If we know the most significant bits we know the values |
1304 | value ranges by means of treating varying bits as zero | |
1305 | or one. Do a cross comparison of the max/min pairs. */ | |
1306 | maxmin = double_int_cmp (double_int_ior (r1val, r1mask), | |
1307 | double_int_and_not (r2val, r2mask), uns); | |
1308 | minmax = double_int_cmp (double_int_and_not (r1val, r1mask), | |
1309 | double_int_ior (r2val, r2mask), uns); | |
1310 | if (maxmin < 0) /* r1 is less than r2. */ | |
1311 | { | |
1312 | *mask = double_int_zero; | |
1313 | *val = double_int_one; | |
1314 | } | |
1315 | else if (minmax > 0) /* r1 is not less or equal to r2. */ | |
1316 | { | |
1317 | *mask = double_int_zero; | |
1318 | *val = double_int_zero; | |
1319 | } | |
1320 | else if (maxmin == minmax) /* r1 and r2 are equal. */ | |
1321 | { | |
1322 | /* This probably should never happen as we'd have | |
1323 | folded the thing during fully constant value folding. */ | |
1324 | *mask = double_int_zero; | |
1325 | *val = (code == LE_EXPR ? double_int_one : double_int_zero); | |
1326 | } | |
1327 | else | |
1328 | { | |
1329 | /* We know the result of a comparison is always one or zero. */ | |
1330 | *mask = double_int_one; | |
1331 | *val = double_int_zero; | |
1332 | } | |
1333 | break; | |
1334 | } | |
1335 | ||
1336 | default:; | |
1337 | } | |
1338 | } | |
1339 | ||
1340 | /* Return the propagation value when applying the operation CODE to | |
1341 | the value RHS yielding type TYPE. */ | |
1342 | ||
1343 | static prop_value_t | |
1344 | bit_value_unop (enum tree_code code, tree type, tree rhs) | |
1345 | { | |
1346 | prop_value_t rval = get_value_for_expr (rhs, true); | |
1347 | double_int value, mask; | |
1348 | prop_value_t val; | |
c91fedc5 | 1349 | |
1350 | if (rval.lattice_val == UNDEFINED) | |
1351 | return rval; | |
1352 | ||
b7e55469 | 1353 | gcc_assert ((rval.lattice_val == CONSTANT |
1354 | && TREE_CODE (rval.value) == INTEGER_CST) | |
1355 | || double_int_minus_one_p (rval.mask)); | |
1356 | bit_value_unop_1 (code, type, &value, &mask, | |
1357 | TREE_TYPE (rhs), value_to_double_int (rval), rval.mask); | |
1358 | if (!double_int_minus_one_p (mask)) | |
1359 | { | |
1360 | val.lattice_val = CONSTANT; | |
1361 | val.mask = mask; | |
1362 | /* ??? Delay building trees here. */ | |
1363 | val.value = double_int_to_tree (type, value); | |
1364 | } | |
1365 | else | |
1366 | { | |
1367 | val.lattice_val = VARYING; | |
1368 | val.value = NULL_TREE; | |
1369 | val.mask = double_int_minus_one; | |
1370 | } | |
1371 | return val; | |
1372 | } | |
1373 | ||
1374 | /* Return the propagation value when applying the operation CODE to | |
1375 | the values RHS1 and RHS2 yielding type TYPE. */ | |
1376 | ||
1377 | static prop_value_t | |
1378 | bit_value_binop (enum tree_code code, tree type, tree rhs1, tree rhs2) | |
1379 | { | |
1380 | prop_value_t r1val = get_value_for_expr (rhs1, true); | |
1381 | prop_value_t r2val = get_value_for_expr (rhs2, true); | |
1382 | double_int value, mask; | |
1383 | prop_value_t val; | |
c91fedc5 | 1384 | |
1385 | if (r1val.lattice_val == UNDEFINED | |
1386 | || r2val.lattice_val == UNDEFINED) | |
1387 | { | |
1388 | val.lattice_val = VARYING; | |
1389 | val.value = NULL_TREE; | |
1390 | val.mask = double_int_minus_one; | |
1391 | return val; | |
1392 | } | |
1393 | ||
b7e55469 | 1394 | gcc_assert ((r1val.lattice_val == CONSTANT |
1395 | && TREE_CODE (r1val.value) == INTEGER_CST) | |
1396 | || double_int_minus_one_p (r1val.mask)); | |
1397 | gcc_assert ((r2val.lattice_val == CONSTANT | |
1398 | && TREE_CODE (r2val.value) == INTEGER_CST) | |
1399 | || double_int_minus_one_p (r2val.mask)); | |
1400 | bit_value_binop_1 (code, type, &value, &mask, | |
1401 | TREE_TYPE (rhs1), value_to_double_int (r1val), r1val.mask, | |
1402 | TREE_TYPE (rhs2), value_to_double_int (r2val), r2val.mask); | |
1403 | if (!double_int_minus_one_p (mask)) | |
1404 | { | |
1405 | val.lattice_val = CONSTANT; | |
1406 | val.mask = mask; | |
1407 | /* ??? Delay building trees here. */ | |
1408 | val.value = double_int_to_tree (type, value); | |
1409 | } | |
1410 | else | |
1411 | { | |
1412 | val.lattice_val = VARYING; | |
1413 | val.value = NULL_TREE; | |
1414 | val.mask = double_int_minus_one; | |
1415 | } | |
1416 | return val; | |
1417 | } | |
1418 | ||
fca0886c | 1419 | /* Return the propagation value when applying __builtin_assume_aligned to |
1420 | its arguments. */ | |
1421 | ||
1422 | static prop_value_t | |
1423 | bit_value_assume_aligned (gimple stmt) | |
1424 | { | |
1425 | tree ptr = gimple_call_arg (stmt, 0), align, misalign = NULL_TREE; | |
1426 | tree type = TREE_TYPE (ptr); | |
1427 | unsigned HOST_WIDE_INT aligni, misaligni = 0; | |
1428 | prop_value_t ptrval = get_value_for_expr (ptr, true); | |
1429 | prop_value_t alignval; | |
1430 | double_int value, mask; | |
1431 | prop_value_t val; | |
1432 | if (ptrval.lattice_val == UNDEFINED) | |
1433 | return ptrval; | |
1434 | gcc_assert ((ptrval.lattice_val == CONSTANT | |
1435 | && TREE_CODE (ptrval.value) == INTEGER_CST) | |
1436 | || double_int_minus_one_p (ptrval.mask)); | |
1437 | align = gimple_call_arg (stmt, 1); | |
1438 | if (!host_integerp (align, 1)) | |
1439 | return ptrval; | |
1440 | aligni = tree_low_cst (align, 1); | |
1441 | if (aligni <= 1 | |
1442 | || (aligni & (aligni - 1)) != 0) | |
1443 | return ptrval; | |
1444 | if (gimple_call_num_args (stmt) > 2) | |
1445 | { | |
1446 | misalign = gimple_call_arg (stmt, 2); | |
1447 | if (!host_integerp (misalign, 1)) | |
1448 | return ptrval; | |
1449 | misaligni = tree_low_cst (misalign, 1); | |
1450 | if (misaligni >= aligni) | |
1451 | return ptrval; | |
1452 | } | |
1453 | align = build_int_cst_type (type, -aligni); | |
1454 | alignval = get_value_for_expr (align, true); | |
1455 | bit_value_binop_1 (BIT_AND_EXPR, type, &value, &mask, | |
1456 | type, value_to_double_int (ptrval), ptrval.mask, | |
1457 | type, value_to_double_int (alignval), alignval.mask); | |
1458 | if (!double_int_minus_one_p (mask)) | |
1459 | { | |
1460 | val.lattice_val = CONSTANT; | |
1461 | val.mask = mask; | |
1462 | gcc_assert ((mask.low & (aligni - 1)) == 0); | |
1463 | gcc_assert ((value.low & (aligni - 1)) == 0); | |
1464 | value.low |= misaligni; | |
1465 | /* ??? Delay building trees here. */ | |
1466 | val.value = double_int_to_tree (type, value); | |
1467 | } | |
1468 | else | |
1469 | { | |
1470 | val.lattice_val = VARYING; | |
1471 | val.value = NULL_TREE; | |
1472 | val.mask = double_int_minus_one; | |
1473 | } | |
1474 | return val; | |
1475 | } | |
1476 | ||
75a70cf9 | 1477 | /* Evaluate statement STMT. |
1478 | Valid only for assignments, calls, conditionals, and switches. */ | |
4ee9c684 | 1479 | |
88dbf20f | 1480 | static prop_value_t |
75a70cf9 | 1481 | evaluate_stmt (gimple stmt) |
4ee9c684 | 1482 | { |
88dbf20f | 1483 | prop_value_t val; |
4f61cce6 | 1484 | tree simplified = NULL_TREE; |
88dbf20f | 1485 | ccp_lattice_t likelyvalue = likely_value (stmt); |
b7e55469 | 1486 | bool is_constant = false; |
581bf1c2 | 1487 | unsigned int align; |
88dbf20f | 1488 | |
b7e55469 | 1489 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1490 | { | |
1491 | fprintf (dump_file, "which is likely "); | |
1492 | switch (likelyvalue) | |
1493 | { | |
1494 | case CONSTANT: | |
1495 | fprintf (dump_file, "CONSTANT"); | |
1496 | break; | |
1497 | case UNDEFINED: | |
1498 | fprintf (dump_file, "UNDEFINED"); | |
1499 | break; | |
1500 | case VARYING: | |
1501 | fprintf (dump_file, "VARYING"); | |
1502 | break; | |
1503 | default:; | |
1504 | } | |
1505 | fprintf (dump_file, "\n"); | |
1506 | } | |
add6ee5e | 1507 | |
4ee9c684 | 1508 | /* If the statement is likely to have a CONSTANT result, then try |
1509 | to fold the statement to determine the constant value. */ | |
75a70cf9 | 1510 | /* FIXME. This is the only place that we call ccp_fold. |
1511 | Since likely_value never returns CONSTANT for calls, we will | |
1512 | not attempt to fold them, including builtins that may profit. */ | |
4ee9c684 | 1513 | if (likelyvalue == CONSTANT) |
b7e55469 | 1514 | { |
1515 | fold_defer_overflow_warnings (); | |
1516 | simplified = ccp_fold (stmt); | |
1517 | is_constant = simplified && is_gimple_min_invariant (simplified); | |
1518 | fold_undefer_overflow_warnings (is_constant, stmt, 0); | |
1519 | if (is_constant) | |
1520 | { | |
1521 | /* The statement produced a constant value. */ | |
1522 | val.lattice_val = CONSTANT; | |
1523 | val.value = simplified; | |
1524 | val.mask = double_int_zero; | |
1525 | } | |
1526 | } | |
4ee9c684 | 1527 | /* If the statement is likely to have a VARYING result, then do not |
1528 | bother folding the statement. */ | |
04236c3a | 1529 | else if (likelyvalue == VARYING) |
75a70cf9 | 1530 | { |
590c3166 | 1531 | enum gimple_code code = gimple_code (stmt); |
75a70cf9 | 1532 | if (code == GIMPLE_ASSIGN) |
1533 | { | |
1534 | enum tree_code subcode = gimple_assign_rhs_code (stmt); | |
48e1416a | 1535 | |
75a70cf9 | 1536 | /* Other cases cannot satisfy is_gimple_min_invariant |
1537 | without folding. */ | |
1538 | if (get_gimple_rhs_class (subcode) == GIMPLE_SINGLE_RHS) | |
1539 | simplified = gimple_assign_rhs1 (stmt); | |
1540 | } | |
1541 | else if (code == GIMPLE_SWITCH) | |
1542 | simplified = gimple_switch_index (stmt); | |
1543 | else | |
a65c4d64 | 1544 | /* These cannot satisfy is_gimple_min_invariant without folding. */ |
1545 | gcc_assert (code == GIMPLE_CALL || code == GIMPLE_COND); | |
b7e55469 | 1546 | is_constant = simplified && is_gimple_min_invariant (simplified); |
1547 | if (is_constant) | |
1548 | { | |
1549 | /* The statement produced a constant value. */ | |
1550 | val.lattice_val = CONSTANT; | |
1551 | val.value = simplified; | |
1552 | val.mask = double_int_zero; | |
1553 | } | |
75a70cf9 | 1554 | } |
4ee9c684 | 1555 | |
b7e55469 | 1556 | /* Resort to simplification for bitwise tracking. */ |
1557 | if (flag_tree_bit_ccp | |
939514e9 | 1558 | && (likelyvalue == CONSTANT || is_gimple_call (stmt)) |
b7e55469 | 1559 | && !is_constant) |
912f109f | 1560 | { |
b7e55469 | 1561 | enum gimple_code code = gimple_code (stmt); |
153c3b50 | 1562 | tree fndecl; |
b7e55469 | 1563 | val.lattice_val = VARYING; |
1564 | val.value = NULL_TREE; | |
1565 | val.mask = double_int_minus_one; | |
1566 | if (code == GIMPLE_ASSIGN) | |
912f109f | 1567 | { |
b7e55469 | 1568 | enum tree_code subcode = gimple_assign_rhs_code (stmt); |
1569 | tree rhs1 = gimple_assign_rhs1 (stmt); | |
1570 | switch (get_gimple_rhs_class (subcode)) | |
1571 | { | |
1572 | case GIMPLE_SINGLE_RHS: | |
1573 | if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
1574 | || POINTER_TYPE_P (TREE_TYPE (rhs1))) | |
1575 | val = get_value_for_expr (rhs1, true); | |
1576 | break; | |
1577 | ||
1578 | case GIMPLE_UNARY_RHS: | |
1579 | if ((INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
1580 | || POINTER_TYPE_P (TREE_TYPE (rhs1))) | |
1581 | && (INTEGRAL_TYPE_P (gimple_expr_type (stmt)) | |
1582 | || POINTER_TYPE_P (gimple_expr_type (stmt)))) | |
1583 | val = bit_value_unop (subcode, gimple_expr_type (stmt), rhs1); | |
1584 | break; | |
1585 | ||
1586 | case GIMPLE_BINARY_RHS: | |
1587 | if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
1588 | || POINTER_TYPE_P (TREE_TYPE (rhs1))) | |
1589 | { | |
e47d81e0 | 1590 | tree lhs = gimple_assign_lhs (stmt); |
b7e55469 | 1591 | tree rhs2 = gimple_assign_rhs2 (stmt); |
1592 | val = bit_value_binop (subcode, | |
e47d81e0 | 1593 | TREE_TYPE (lhs), rhs1, rhs2); |
b7e55469 | 1594 | } |
1595 | break; | |
1596 | ||
1597 | default:; | |
1598 | } | |
912f109f | 1599 | } |
b7e55469 | 1600 | else if (code == GIMPLE_COND) |
1601 | { | |
1602 | enum tree_code code = gimple_cond_code (stmt); | |
1603 | tree rhs1 = gimple_cond_lhs (stmt); | |
1604 | tree rhs2 = gimple_cond_rhs (stmt); | |
1605 | if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
1606 | || POINTER_TYPE_P (TREE_TYPE (rhs1))) | |
1607 | val = bit_value_binop (code, TREE_TYPE (rhs1), rhs1, rhs2); | |
1608 | } | |
153c3b50 | 1609 | else if (code == GIMPLE_CALL |
1610 | && (fndecl = gimple_call_fndecl (stmt)) | |
1611 | && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL) | |
1612 | { | |
1613 | switch (DECL_FUNCTION_CODE (fndecl)) | |
1614 | { | |
1615 | case BUILT_IN_MALLOC: | |
1616 | case BUILT_IN_REALLOC: | |
1617 | case BUILT_IN_CALLOC: | |
939514e9 | 1618 | case BUILT_IN_STRDUP: |
1619 | case BUILT_IN_STRNDUP: | |
153c3b50 | 1620 | val.lattice_val = CONSTANT; |
1621 | val.value = build_int_cst (TREE_TYPE (gimple_get_lhs (stmt)), 0); | |
1622 | val.mask = shwi_to_double_int | |
1623 | (~(((HOST_WIDE_INT) MALLOC_ABI_ALIGNMENT) | |
1624 | / BITS_PER_UNIT - 1)); | |
1625 | break; | |
1626 | ||
1627 | case BUILT_IN_ALLOCA: | |
581bf1c2 | 1628 | case BUILT_IN_ALLOCA_WITH_ALIGN: |
1629 | align = (DECL_FUNCTION_CODE (fndecl) == BUILT_IN_ALLOCA_WITH_ALIGN | |
1630 | ? TREE_INT_CST_LOW (gimple_call_arg (stmt, 1)) | |
1631 | : BIGGEST_ALIGNMENT); | |
153c3b50 | 1632 | val.lattice_val = CONSTANT; |
1633 | val.value = build_int_cst (TREE_TYPE (gimple_get_lhs (stmt)), 0); | |
1634 | val.mask = shwi_to_double_int | |
581bf1c2 | 1635 | (~(((HOST_WIDE_INT) align) |
153c3b50 | 1636 | / BITS_PER_UNIT - 1)); |
1637 | break; | |
1638 | ||
939514e9 | 1639 | /* These builtins return their first argument, unmodified. */ |
1640 | case BUILT_IN_MEMCPY: | |
1641 | case BUILT_IN_MEMMOVE: | |
1642 | case BUILT_IN_MEMSET: | |
1643 | case BUILT_IN_STRCPY: | |
1644 | case BUILT_IN_STRNCPY: | |
1645 | case BUILT_IN_MEMCPY_CHK: | |
1646 | case BUILT_IN_MEMMOVE_CHK: | |
1647 | case BUILT_IN_MEMSET_CHK: | |
1648 | case BUILT_IN_STRCPY_CHK: | |
1649 | case BUILT_IN_STRNCPY_CHK: | |
1650 | val = get_value_for_expr (gimple_call_arg (stmt, 0), true); | |
1651 | break; | |
1652 | ||
fca0886c | 1653 | case BUILT_IN_ASSUME_ALIGNED: |
1654 | val = bit_value_assume_aligned (stmt); | |
1655 | break; | |
1656 | ||
153c3b50 | 1657 | default:; |
1658 | } | |
1659 | } | |
b7e55469 | 1660 | is_constant = (val.lattice_val == CONSTANT); |
912f109f | 1661 | } |
1662 | ||
b7e55469 | 1663 | if (!is_constant) |
4ee9c684 | 1664 | { |
1665 | /* The statement produced a nonconstant value. If the statement | |
88dbf20f | 1666 | had UNDEFINED operands, then the result of the statement |
1667 | should be UNDEFINED. Otherwise, the statement is VARYING. */ | |
bfa30570 | 1668 | if (likelyvalue == UNDEFINED) |
b7e55469 | 1669 | { |
1670 | val.lattice_val = likelyvalue; | |
1671 | val.mask = double_int_zero; | |
1672 | } | |
b765fa12 | 1673 | else |
b7e55469 | 1674 | { |
1675 | val.lattice_val = VARYING; | |
1676 | val.mask = double_int_minus_one; | |
1677 | } | |
b765fa12 | 1678 | |
88dbf20f | 1679 | val.value = NULL_TREE; |
4ee9c684 | 1680 | } |
41511585 | 1681 | |
1682 | return val; | |
4ee9c684 | 1683 | } |
1684 | ||
582a80ed | 1685 | /* Given a BUILT_IN_STACK_SAVE value SAVED_VAL, insert a clobber of VAR before |
1686 | each matching BUILT_IN_STACK_RESTORE. Mark visited phis in VISITED. */ | |
1687 | ||
1688 | static void | |
1689 | insert_clobber_before_stack_restore (tree saved_val, tree var, htab_t *visited) | |
1690 | { | |
1691 | gimple stmt, clobber_stmt; | |
1692 | tree clobber; | |
1693 | imm_use_iterator iter; | |
1694 | gimple_stmt_iterator i; | |
1695 | gimple *slot; | |
1696 | ||
1697 | FOR_EACH_IMM_USE_STMT (stmt, iter, saved_val) | |
1698 | if (gimple_call_builtin_p (stmt, BUILT_IN_STACK_RESTORE)) | |
1699 | { | |
1700 | clobber = build_constructor (TREE_TYPE (var), NULL); | |
1701 | TREE_THIS_VOLATILE (clobber) = 1; | |
1702 | clobber_stmt = gimple_build_assign (var, clobber); | |
1703 | ||
1704 | i = gsi_for_stmt (stmt); | |
1705 | gsi_insert_before (&i, clobber_stmt, GSI_SAME_STMT); | |
1706 | } | |
1707 | else if (gimple_code (stmt) == GIMPLE_PHI) | |
1708 | { | |
1709 | if (*visited == NULL) | |
1710 | *visited = htab_create (10, htab_hash_pointer, htab_eq_pointer, NULL); | |
1711 | ||
1712 | slot = (gimple *)htab_find_slot (*visited, stmt, INSERT); | |
1713 | if (*slot != NULL) | |
1714 | continue; | |
1715 | ||
1716 | *slot = stmt; | |
1717 | insert_clobber_before_stack_restore (gimple_phi_result (stmt), var, | |
1718 | visited); | |
1719 | } | |
1720 | else | |
1721 | gcc_assert (is_gimple_debug (stmt)); | |
1722 | } | |
1723 | ||
1724 | /* Advance the iterator to the previous non-debug gimple statement in the same | |
1725 | or dominating basic block. */ | |
1726 | ||
1727 | static inline void | |
1728 | gsi_prev_dom_bb_nondebug (gimple_stmt_iterator *i) | |
1729 | { | |
1730 | basic_block dom; | |
1731 | ||
1732 | gsi_prev_nondebug (i); | |
1733 | while (gsi_end_p (*i)) | |
1734 | { | |
1735 | dom = get_immediate_dominator (CDI_DOMINATORS, i->bb); | |
1736 | if (dom == NULL || dom == ENTRY_BLOCK_PTR) | |
1737 | return; | |
1738 | ||
1739 | *i = gsi_last_bb (dom); | |
1740 | } | |
1741 | } | |
1742 | ||
1743 | /* Find a BUILT_IN_STACK_SAVE dominating gsi_stmt (I), and insert | |
1543f720 | 1744 | a clobber of VAR before each matching BUILT_IN_STACK_RESTORE. |
1745 | ||
1746 | It is possible that BUILT_IN_STACK_SAVE cannot be find in a dominator when a | |
1747 | previous pass (such as DOM) duplicated it along multiple paths to a BB. In | |
1748 | that case the function gives up without inserting the clobbers. */ | |
582a80ed | 1749 | |
1750 | static void | |
1751 | insert_clobbers_for_var (gimple_stmt_iterator i, tree var) | |
1752 | { | |
582a80ed | 1753 | gimple stmt; |
1754 | tree saved_val; | |
1755 | htab_t visited = NULL; | |
1756 | ||
1543f720 | 1757 | for (; !gsi_end_p (i); gsi_prev_dom_bb_nondebug (&i)) |
582a80ed | 1758 | { |
1759 | stmt = gsi_stmt (i); | |
1760 | ||
1761 | if (!gimple_call_builtin_p (stmt, BUILT_IN_STACK_SAVE)) | |
1762 | continue; | |
582a80ed | 1763 | |
1764 | saved_val = gimple_call_lhs (stmt); | |
1765 | if (saved_val == NULL_TREE) | |
1766 | continue; | |
1767 | ||
1768 | insert_clobber_before_stack_restore (saved_val, var, &visited); | |
1769 | break; | |
1770 | } | |
1771 | ||
1772 | if (visited != NULL) | |
1773 | htab_delete (visited); | |
582a80ed | 1774 | } |
1775 | ||
581bf1c2 | 1776 | /* Detects a __builtin_alloca_with_align with constant size argument. Declares |
1777 | fixed-size array and returns the address, if found, otherwise returns | |
1778 | NULL_TREE. */ | |
9a65cc0a | 1779 | |
1780 | static tree | |
581bf1c2 | 1781 | fold_builtin_alloca_with_align (gimple stmt) |
9a65cc0a | 1782 | { |
1783 | unsigned HOST_WIDE_INT size, threshold, n_elem; | |
1784 | tree lhs, arg, block, var, elem_type, array_type; | |
9a65cc0a | 1785 | |
1786 | /* Get lhs. */ | |
1787 | lhs = gimple_call_lhs (stmt); | |
1788 | if (lhs == NULL_TREE) | |
1789 | return NULL_TREE; | |
1790 | ||
1791 | /* Detect constant argument. */ | |
1792 | arg = get_constant_value (gimple_call_arg (stmt, 0)); | |
6e93d308 | 1793 | if (arg == NULL_TREE |
1794 | || TREE_CODE (arg) != INTEGER_CST | |
9a65cc0a | 1795 | || !host_integerp (arg, 1)) |
1796 | return NULL_TREE; | |
6e93d308 | 1797 | |
9a65cc0a | 1798 | size = TREE_INT_CST_LOW (arg); |
1799 | ||
581bf1c2 | 1800 | /* Heuristic: don't fold large allocas. */ |
9a65cc0a | 1801 | threshold = (unsigned HOST_WIDE_INT)PARAM_VALUE (PARAM_LARGE_STACK_FRAME); |
581bf1c2 | 1802 | /* In case the alloca is located at function entry, it has the same lifetime |
1803 | as a declared array, so we allow a larger size. */ | |
9a65cc0a | 1804 | block = gimple_block (stmt); |
1805 | if (!(cfun->after_inlining | |
1806 | && TREE_CODE (BLOCK_SUPERCONTEXT (block)) == FUNCTION_DECL)) | |
1807 | threshold /= 10; | |
1808 | if (size > threshold) | |
1809 | return NULL_TREE; | |
1810 | ||
1811 | /* Declare array. */ | |
1812 | elem_type = build_nonstandard_integer_type (BITS_PER_UNIT, 1); | |
1813 | n_elem = size * 8 / BITS_PER_UNIT; | |
9a65cc0a | 1814 | array_type = build_array_type_nelts (elem_type, n_elem); |
1815 | var = create_tmp_var (array_type, NULL); | |
581bf1c2 | 1816 | DECL_ALIGN (var) = TREE_INT_CST_LOW (gimple_call_arg (stmt, 1)); |
3d4a0a4b | 1817 | { |
1818 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (lhs); | |
1819 | if (pi != NULL && !pi->pt.anything) | |
1820 | { | |
1821 | bool singleton_p; | |
1822 | unsigned uid; | |
1823 | singleton_p = pt_solution_singleton_p (&pi->pt, &uid); | |
1824 | gcc_assert (singleton_p); | |
1825 | SET_DECL_PT_UID (var, uid); | |
1826 | } | |
1827 | } | |
9a65cc0a | 1828 | |
1829 | /* Fold alloca to the address of the array. */ | |
1830 | return fold_convert (TREE_TYPE (lhs), build_fold_addr_expr (var)); | |
1831 | } | |
1832 | ||
6688f8ec | 1833 | /* Fold the stmt at *GSI with CCP specific information that propagating |
1834 | and regular folding does not catch. */ | |
1835 | ||
1836 | static bool | |
1837 | ccp_fold_stmt (gimple_stmt_iterator *gsi) | |
1838 | { | |
1839 | gimple stmt = gsi_stmt (*gsi); | |
6688f8ec | 1840 | |
94144e68 | 1841 | switch (gimple_code (stmt)) |
1842 | { | |
1843 | case GIMPLE_COND: | |
1844 | { | |
1845 | prop_value_t val; | |
1846 | /* Statement evaluation will handle type mismatches in constants | |
1847 | more gracefully than the final propagation. This allows us to | |
1848 | fold more conditionals here. */ | |
1849 | val = evaluate_stmt (stmt); | |
1850 | if (val.lattice_val != CONSTANT | |
b7e55469 | 1851 | || !double_int_zero_p (val.mask)) |
94144e68 | 1852 | return false; |
1853 | ||
b7e55469 | 1854 | if (dump_file) |
1855 | { | |
1856 | fprintf (dump_file, "Folding predicate "); | |
1857 | print_gimple_expr (dump_file, stmt, 0, 0); | |
1858 | fprintf (dump_file, " to "); | |
1859 | print_generic_expr (dump_file, val.value, 0); | |
1860 | fprintf (dump_file, "\n"); | |
1861 | } | |
1862 | ||
94144e68 | 1863 | if (integer_zerop (val.value)) |
1864 | gimple_cond_make_false (stmt); | |
1865 | else | |
1866 | gimple_cond_make_true (stmt); | |
6688f8ec | 1867 | |
94144e68 | 1868 | return true; |
1869 | } | |
6688f8ec | 1870 | |
94144e68 | 1871 | case GIMPLE_CALL: |
1872 | { | |
1873 | tree lhs = gimple_call_lhs (stmt); | |
3064bb7b | 1874 | int flags = gimple_call_flags (stmt); |
15d138c9 | 1875 | tree val; |
94144e68 | 1876 | tree argt; |
1877 | bool changed = false; | |
1878 | unsigned i; | |
1879 | ||
1880 | /* If the call was folded into a constant make sure it goes | |
1881 | away even if we cannot propagate into all uses because of | |
1882 | type issues. */ | |
1883 | if (lhs | |
1884 | && TREE_CODE (lhs) == SSA_NAME | |
3064bb7b | 1885 | && (val = get_constant_value (lhs)) |
1886 | /* Don't optimize away calls that have side-effects. */ | |
1887 | && (flags & (ECF_CONST|ECF_PURE)) != 0 | |
1888 | && (flags & ECF_LOOPING_CONST_OR_PURE) == 0) | |
94144e68 | 1889 | { |
15d138c9 | 1890 | tree new_rhs = unshare_expr (val); |
338cce8f | 1891 | bool res; |
94144e68 | 1892 | if (!useless_type_conversion_p (TREE_TYPE (lhs), |
1893 | TREE_TYPE (new_rhs))) | |
1894 | new_rhs = fold_convert (TREE_TYPE (lhs), new_rhs); | |
338cce8f | 1895 | res = update_call_from_tree (gsi, new_rhs); |
1896 | gcc_assert (res); | |
94144e68 | 1897 | return true; |
1898 | } | |
1899 | ||
fb049fba | 1900 | /* Internal calls provide no argument types, so the extra laxity |
1901 | for normal calls does not apply. */ | |
1902 | if (gimple_call_internal_p (stmt)) | |
1903 | return false; | |
1904 | ||
581bf1c2 | 1905 | /* The heuristic of fold_builtin_alloca_with_align differs before and |
1906 | after inlining, so we don't require the arg to be changed into a | |
1907 | constant for folding, but just to be constant. */ | |
1908 | if (gimple_call_builtin_p (stmt, BUILT_IN_ALLOCA_WITH_ALIGN)) | |
9a65cc0a | 1909 | { |
581bf1c2 | 1910 | tree new_rhs = fold_builtin_alloca_with_align (stmt); |
6e93d308 | 1911 | if (new_rhs) |
1912 | { | |
1913 | bool res = update_call_from_tree (gsi, new_rhs); | |
582a80ed | 1914 | tree var = TREE_OPERAND (TREE_OPERAND (new_rhs, 0),0); |
6e93d308 | 1915 | gcc_assert (res); |
582a80ed | 1916 | insert_clobbers_for_var (*gsi, var); |
6e93d308 | 1917 | return true; |
1918 | } | |
9a65cc0a | 1919 | } |
1920 | ||
94144e68 | 1921 | /* Propagate into the call arguments. Compared to replace_uses_in |
1922 | this can use the argument slot types for type verification | |
1923 | instead of the current argument type. We also can safely | |
1924 | drop qualifiers here as we are dealing with constants anyway. */ | |
2de00a2d | 1925 | argt = TYPE_ARG_TYPES (gimple_call_fntype (stmt)); |
94144e68 | 1926 | for (i = 0; i < gimple_call_num_args (stmt) && argt; |
1927 | ++i, argt = TREE_CHAIN (argt)) | |
1928 | { | |
1929 | tree arg = gimple_call_arg (stmt, i); | |
1930 | if (TREE_CODE (arg) == SSA_NAME | |
15d138c9 | 1931 | && (val = get_constant_value (arg)) |
94144e68 | 1932 | && useless_type_conversion_p |
1933 | (TYPE_MAIN_VARIANT (TREE_VALUE (argt)), | |
15d138c9 | 1934 | TYPE_MAIN_VARIANT (TREE_TYPE (val)))) |
94144e68 | 1935 | { |
15d138c9 | 1936 | gimple_call_set_arg (stmt, i, unshare_expr (val)); |
94144e68 | 1937 | changed = true; |
1938 | } | |
1939 | } | |
e16f4c39 | 1940 | |
94144e68 | 1941 | return changed; |
1942 | } | |
6688f8ec | 1943 | |
6872bf3c | 1944 | case GIMPLE_ASSIGN: |
1945 | { | |
1946 | tree lhs = gimple_assign_lhs (stmt); | |
15d138c9 | 1947 | tree val; |
6872bf3c | 1948 | |
1949 | /* If we have a load that turned out to be constant replace it | |
1950 | as we cannot propagate into all uses in all cases. */ | |
1951 | if (gimple_assign_single_p (stmt) | |
1952 | && TREE_CODE (lhs) == SSA_NAME | |
15d138c9 | 1953 | && (val = get_constant_value (lhs))) |
6872bf3c | 1954 | { |
15d138c9 | 1955 | tree rhs = unshare_expr (val); |
6872bf3c | 1956 | if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs))) |
182cf5a9 | 1957 | rhs = fold_build1 (VIEW_CONVERT_EXPR, TREE_TYPE (lhs), rhs); |
6872bf3c | 1958 | gimple_assign_set_rhs_from_tree (gsi, rhs); |
1959 | return true; | |
1960 | } | |
1961 | ||
1962 | return false; | |
1963 | } | |
1964 | ||
94144e68 | 1965 | default: |
1966 | return false; | |
1967 | } | |
6688f8ec | 1968 | } |
1969 | ||
41511585 | 1970 | /* Visit the assignment statement STMT. Set the value of its LHS to the |
88dbf20f | 1971 | value computed by the RHS and store LHS in *OUTPUT_P. If STMT |
1972 | creates virtual definitions, set the value of each new name to that | |
75a70cf9 | 1973 | of the RHS (if we can derive a constant out of the RHS). |
1974 | Value-returning call statements also perform an assignment, and | |
1975 | are handled here. */ | |
4ee9c684 | 1976 | |
41511585 | 1977 | static enum ssa_prop_result |
75a70cf9 | 1978 | visit_assignment (gimple stmt, tree *output_p) |
4ee9c684 | 1979 | { |
88dbf20f | 1980 | prop_value_t val; |
88dbf20f | 1981 | enum ssa_prop_result retval; |
4ee9c684 | 1982 | |
75a70cf9 | 1983 | tree lhs = gimple_get_lhs (stmt); |
4ee9c684 | 1984 | |
75a70cf9 | 1985 | gcc_assert (gimple_code (stmt) != GIMPLE_CALL |
1986 | || gimple_call_lhs (stmt) != NULL_TREE); | |
1987 | ||
15d138c9 | 1988 | if (gimple_assign_single_p (stmt) |
1989 | && gimple_assign_rhs_code (stmt) == SSA_NAME) | |
1990 | /* For a simple copy operation, we copy the lattice values. */ | |
1991 | val = *get_value (gimple_assign_rhs1 (stmt)); | |
41511585 | 1992 | else |
75a70cf9 | 1993 | /* Evaluate the statement, which could be |
1994 | either a GIMPLE_ASSIGN or a GIMPLE_CALL. */ | |
04236c3a | 1995 | val = evaluate_stmt (stmt); |
4ee9c684 | 1996 | |
88dbf20f | 1997 | retval = SSA_PROP_NOT_INTERESTING; |
4ee9c684 | 1998 | |
41511585 | 1999 | /* Set the lattice value of the statement's output. */ |
88dbf20f | 2000 | if (TREE_CODE (lhs) == SSA_NAME) |
4ee9c684 | 2001 | { |
88dbf20f | 2002 | /* If STMT is an assignment to an SSA_NAME, we only have one |
2003 | value to set. */ | |
2004 | if (set_lattice_value (lhs, val)) | |
2005 | { | |
2006 | *output_p = lhs; | |
2007 | if (val.lattice_val == VARYING) | |
2008 | retval = SSA_PROP_VARYING; | |
2009 | else | |
2010 | retval = SSA_PROP_INTERESTING; | |
2011 | } | |
4ee9c684 | 2012 | } |
88dbf20f | 2013 | |
2014 | return retval; | |
4ee9c684 | 2015 | } |
2016 | ||
4ee9c684 | 2017 | |
41511585 | 2018 | /* Visit the conditional statement STMT. Return SSA_PROP_INTERESTING |
2019 | if it can determine which edge will be taken. Otherwise, return | |
2020 | SSA_PROP_VARYING. */ | |
2021 | ||
2022 | static enum ssa_prop_result | |
75a70cf9 | 2023 | visit_cond_stmt (gimple stmt, edge *taken_edge_p) |
4ee9c684 | 2024 | { |
88dbf20f | 2025 | prop_value_t val; |
41511585 | 2026 | basic_block block; |
2027 | ||
75a70cf9 | 2028 | block = gimple_bb (stmt); |
41511585 | 2029 | val = evaluate_stmt (stmt); |
b7e55469 | 2030 | if (val.lattice_val != CONSTANT |
2031 | || !double_int_zero_p (val.mask)) | |
2032 | return SSA_PROP_VARYING; | |
41511585 | 2033 | |
2034 | /* Find which edge out of the conditional block will be taken and add it | |
2035 | to the worklist. If no single edge can be determined statically, | |
2036 | return SSA_PROP_VARYING to feed all the outgoing edges to the | |
2037 | propagation engine. */ | |
b7e55469 | 2038 | *taken_edge_p = find_taken_edge (block, val.value); |
41511585 | 2039 | if (*taken_edge_p) |
2040 | return SSA_PROP_INTERESTING; | |
2041 | else | |
2042 | return SSA_PROP_VARYING; | |
4ee9c684 | 2043 | } |
2044 | ||
4ee9c684 | 2045 | |
41511585 | 2046 | /* Evaluate statement STMT. If the statement produces an output value and |
2047 | its evaluation changes the lattice value of its output, return | |
2048 | SSA_PROP_INTERESTING and set *OUTPUT_P to the SSA_NAME holding the | |
2049 | output value. | |
48e1416a | 2050 | |
41511585 | 2051 | If STMT is a conditional branch and we can determine its truth |
2052 | value, set *TAKEN_EDGE_P accordingly. If STMT produces a varying | |
2053 | value, return SSA_PROP_VARYING. */ | |
4ee9c684 | 2054 | |
41511585 | 2055 | static enum ssa_prop_result |
75a70cf9 | 2056 | ccp_visit_stmt (gimple stmt, edge *taken_edge_p, tree *output_p) |
41511585 | 2057 | { |
41511585 | 2058 | tree def; |
2059 | ssa_op_iter iter; | |
4ee9c684 | 2060 | |
41511585 | 2061 | if (dump_file && (dump_flags & TDF_DETAILS)) |
4ee9c684 | 2062 | { |
88dbf20f | 2063 | fprintf (dump_file, "\nVisiting statement:\n"); |
75a70cf9 | 2064 | print_gimple_stmt (dump_file, stmt, 0, dump_flags); |
4ee9c684 | 2065 | } |
4ee9c684 | 2066 | |
75a70cf9 | 2067 | switch (gimple_code (stmt)) |
4ee9c684 | 2068 | { |
75a70cf9 | 2069 | case GIMPLE_ASSIGN: |
2070 | /* If the statement is an assignment that produces a single | |
2071 | output value, evaluate its RHS to see if the lattice value of | |
2072 | its output has changed. */ | |
2073 | return visit_assignment (stmt, output_p); | |
2074 | ||
2075 | case GIMPLE_CALL: | |
2076 | /* A value-returning call also performs an assignment. */ | |
2077 | if (gimple_call_lhs (stmt) != NULL_TREE) | |
2078 | return visit_assignment (stmt, output_p); | |
2079 | break; | |
2080 | ||
2081 | case GIMPLE_COND: | |
2082 | case GIMPLE_SWITCH: | |
2083 | /* If STMT is a conditional branch, see if we can determine | |
2084 | which branch will be taken. */ | |
2085 | /* FIXME. It appears that we should be able to optimize | |
2086 | computed GOTOs here as well. */ | |
2087 | return visit_cond_stmt (stmt, taken_edge_p); | |
2088 | ||
2089 | default: | |
2090 | break; | |
4ee9c684 | 2091 | } |
4ee9c684 | 2092 | |
41511585 | 2093 | /* Any other kind of statement is not interesting for constant |
2094 | propagation and, therefore, not worth simulating. */ | |
41511585 | 2095 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2096 | fprintf (dump_file, "No interesting values produced. Marked VARYING.\n"); | |
4ee9c684 | 2097 | |
41511585 | 2098 | /* Definitions made by statements other than assignments to |
2099 | SSA_NAMEs represent unknown modifications to their outputs. | |
2100 | Mark them VARYING. */ | |
88dbf20f | 2101 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS) |
2102 | { | |
b7e55469 | 2103 | prop_value_t v = { VARYING, NULL_TREE, { -1, (HOST_WIDE_INT) -1 } }; |
88dbf20f | 2104 | set_lattice_value (def, v); |
2105 | } | |
4ee9c684 | 2106 | |
41511585 | 2107 | return SSA_PROP_VARYING; |
2108 | } | |
4ee9c684 | 2109 | |
4ee9c684 | 2110 | |
88dbf20f | 2111 | /* Main entry point for SSA Conditional Constant Propagation. */ |
41511585 | 2112 | |
33a34f1e | 2113 | static unsigned int |
61207d43 | 2114 | do_ssa_ccp (void) |
41511585 | 2115 | { |
582a80ed | 2116 | unsigned int todo = 0; |
2117 | calculate_dominance_info (CDI_DOMINATORS); | |
41511585 | 2118 | ccp_initialize (); |
2119 | ssa_propagate (ccp_visit_stmt, ccp_visit_phi_node); | |
33a34f1e | 2120 | if (ccp_finalize ()) |
582a80ed | 2121 | todo = (TODO_cleanup_cfg | TODO_update_ssa | TODO_remove_unused_locals); |
2122 | free_dominance_info (CDI_DOMINATORS); | |
2123 | return todo; | |
4ee9c684 | 2124 | } |
2125 | ||
5664499b | 2126 | |
2127 | static bool | |
41511585 | 2128 | gate_ccp (void) |
5664499b | 2129 | { |
41511585 | 2130 | return flag_tree_ccp != 0; |
5664499b | 2131 | } |
2132 | ||
4ee9c684 | 2133 | |
48e1416a | 2134 | struct gimple_opt_pass pass_ccp = |
41511585 | 2135 | { |
20099e35 | 2136 | { |
2137 | GIMPLE_PASS, | |
41511585 | 2138 | "ccp", /* name */ |
2139 | gate_ccp, /* gate */ | |
88dbf20f | 2140 | do_ssa_ccp, /* execute */ |
41511585 | 2141 | NULL, /* sub */ |
2142 | NULL, /* next */ | |
2143 | 0, /* static_pass_number */ | |
2144 | TV_TREE_CCP, /* tv_id */ | |
49290934 | 2145 | PROP_cfg | PROP_ssa, /* properties_required */ |
41511585 | 2146 | 0, /* properties_provided */ |
b6246c40 | 2147 | 0, /* properties_destroyed */ |
41511585 | 2148 | 0, /* todo_flags_start */ |
771e2890 | 2149 | TODO_verify_ssa |
20099e35 | 2150 | | TODO_verify_stmts | TODO_ggc_collect/* todo_flags_finish */ |
2151 | } | |
41511585 | 2152 | }; |
4ee9c684 | 2153 | |
4ee9c684 | 2154 | |
75a70cf9 | 2155 | |
bdd0e199 | 2156 | /* Try to optimize out __builtin_stack_restore. Optimize it out |
2157 | if there is another __builtin_stack_restore in the same basic | |
2158 | block and no calls or ASM_EXPRs are in between, or if this block's | |
2159 | only outgoing edge is to EXIT_BLOCK and there are no calls or | |
2160 | ASM_EXPRs after this __builtin_stack_restore. */ | |
2161 | ||
2162 | static tree | |
75a70cf9 | 2163 | optimize_stack_restore (gimple_stmt_iterator i) |
bdd0e199 | 2164 | { |
6ea999da | 2165 | tree callee; |
2166 | gimple stmt; | |
75a70cf9 | 2167 | |
2168 | basic_block bb = gsi_bb (i); | |
2169 | gimple call = gsi_stmt (i); | |
bdd0e199 | 2170 | |
75a70cf9 | 2171 | if (gimple_code (call) != GIMPLE_CALL |
2172 | || gimple_call_num_args (call) != 1 | |
2173 | || TREE_CODE (gimple_call_arg (call, 0)) != SSA_NAME | |
2174 | || !POINTER_TYPE_P (TREE_TYPE (gimple_call_arg (call, 0)))) | |
bdd0e199 | 2175 | return NULL_TREE; |
2176 | ||
75a70cf9 | 2177 | for (gsi_next (&i); !gsi_end_p (i); gsi_next (&i)) |
bdd0e199 | 2178 | { |
75a70cf9 | 2179 | stmt = gsi_stmt (i); |
2180 | if (gimple_code (stmt) == GIMPLE_ASM) | |
bdd0e199 | 2181 | return NULL_TREE; |
75a70cf9 | 2182 | if (gimple_code (stmt) != GIMPLE_CALL) |
bdd0e199 | 2183 | continue; |
2184 | ||
75a70cf9 | 2185 | callee = gimple_call_fndecl (stmt); |
c40a6f90 | 2186 | if (!callee |
2187 | || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL | |
2188 | /* All regular builtins are ok, just obviously not alloca. */ | |
581bf1c2 | 2189 | || DECL_FUNCTION_CODE (callee) == BUILT_IN_ALLOCA |
2190 | || DECL_FUNCTION_CODE (callee) == BUILT_IN_ALLOCA_WITH_ALIGN) | |
bdd0e199 | 2191 | return NULL_TREE; |
2192 | ||
2193 | if (DECL_FUNCTION_CODE (callee) == BUILT_IN_STACK_RESTORE) | |
6ea999da | 2194 | goto second_stack_restore; |
bdd0e199 | 2195 | } |
2196 | ||
6ea999da | 2197 | if (!gsi_end_p (i)) |
bdd0e199 | 2198 | return NULL_TREE; |
2199 | ||
6ea999da | 2200 | /* Allow one successor of the exit block, or zero successors. */ |
2201 | switch (EDGE_COUNT (bb->succs)) | |
2202 | { | |
2203 | case 0: | |
2204 | break; | |
2205 | case 1: | |
2206 | if (single_succ_edge (bb)->dest != EXIT_BLOCK_PTR) | |
2207 | return NULL_TREE; | |
2208 | break; | |
2209 | default: | |
2210 | return NULL_TREE; | |
2211 | } | |
2212 | second_stack_restore: | |
bdd0e199 | 2213 | |
6ea999da | 2214 | /* If there's exactly one use, then zap the call to __builtin_stack_save. |
2215 | If there are multiple uses, then the last one should remove the call. | |
2216 | In any case, whether the call to __builtin_stack_save can be removed | |
2217 | or not is irrelevant to removing the call to __builtin_stack_restore. */ | |
2218 | if (has_single_use (gimple_call_arg (call, 0))) | |
2219 | { | |
2220 | gimple stack_save = SSA_NAME_DEF_STMT (gimple_call_arg (call, 0)); | |
2221 | if (is_gimple_call (stack_save)) | |
2222 | { | |
2223 | callee = gimple_call_fndecl (stack_save); | |
2224 | if (callee | |
2225 | && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL | |
2226 | && DECL_FUNCTION_CODE (callee) == BUILT_IN_STACK_SAVE) | |
2227 | { | |
2228 | gimple_stmt_iterator stack_save_gsi; | |
2229 | tree rhs; | |
bdd0e199 | 2230 | |
6ea999da | 2231 | stack_save_gsi = gsi_for_stmt (stack_save); |
2232 | rhs = build_int_cst (TREE_TYPE (gimple_call_arg (call, 0)), 0); | |
2233 | update_call_from_tree (&stack_save_gsi, rhs); | |
2234 | } | |
2235 | } | |
2236 | } | |
bdd0e199 | 2237 | |
75a70cf9 | 2238 | /* No effect, so the statement will be deleted. */ |
bdd0e199 | 2239 | return integer_zero_node; |
2240 | } | |
75a70cf9 | 2241 | |
8a58ed0a | 2242 | /* If va_list type is a simple pointer and nothing special is needed, |
2243 | optimize __builtin_va_start (&ap, 0) into ap = __builtin_next_arg (0), | |
2244 | __builtin_va_end (&ap) out as NOP and __builtin_va_copy into a simple | |
2245 | pointer assignment. */ | |
2246 | ||
2247 | static tree | |
75a70cf9 | 2248 | optimize_stdarg_builtin (gimple call) |
8a58ed0a | 2249 | { |
5f57a8b1 | 2250 | tree callee, lhs, rhs, cfun_va_list; |
8a58ed0a | 2251 | bool va_list_simple_ptr; |
389dd41b | 2252 | location_t loc = gimple_location (call); |
8a58ed0a | 2253 | |
75a70cf9 | 2254 | if (gimple_code (call) != GIMPLE_CALL) |
8a58ed0a | 2255 | return NULL_TREE; |
2256 | ||
75a70cf9 | 2257 | callee = gimple_call_fndecl (call); |
5f57a8b1 | 2258 | |
2259 | cfun_va_list = targetm.fn_abi_va_list (callee); | |
2260 | va_list_simple_ptr = POINTER_TYPE_P (cfun_va_list) | |
2261 | && (TREE_TYPE (cfun_va_list) == void_type_node | |
2262 | || TREE_TYPE (cfun_va_list) == char_type_node); | |
2263 | ||
8a58ed0a | 2264 | switch (DECL_FUNCTION_CODE (callee)) |
2265 | { | |
2266 | case BUILT_IN_VA_START: | |
2267 | if (!va_list_simple_ptr | |
2268 | || targetm.expand_builtin_va_start != NULL | |
e7ed5dd7 | 2269 | || !builtin_decl_explicit_p (BUILT_IN_NEXT_ARG)) |
8a58ed0a | 2270 | return NULL_TREE; |
2271 | ||
75a70cf9 | 2272 | if (gimple_call_num_args (call) != 2) |
8a58ed0a | 2273 | return NULL_TREE; |
2274 | ||
75a70cf9 | 2275 | lhs = gimple_call_arg (call, 0); |
8a58ed0a | 2276 | if (!POINTER_TYPE_P (TREE_TYPE (lhs)) |
2277 | || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs))) | |
5f57a8b1 | 2278 | != TYPE_MAIN_VARIANT (cfun_va_list)) |
8a58ed0a | 2279 | return NULL_TREE; |
48e1416a | 2280 | |
389dd41b | 2281 | lhs = build_fold_indirect_ref_loc (loc, lhs); |
b9a16870 | 2282 | rhs = build_call_expr_loc (loc, builtin_decl_explicit (BUILT_IN_NEXT_ARG), |
75a70cf9 | 2283 | 1, integer_zero_node); |
389dd41b | 2284 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); |
8a58ed0a | 2285 | return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs); |
2286 | ||
2287 | case BUILT_IN_VA_COPY: | |
2288 | if (!va_list_simple_ptr) | |
2289 | return NULL_TREE; | |
2290 | ||
75a70cf9 | 2291 | if (gimple_call_num_args (call) != 2) |
8a58ed0a | 2292 | return NULL_TREE; |
2293 | ||
75a70cf9 | 2294 | lhs = gimple_call_arg (call, 0); |
8a58ed0a | 2295 | if (!POINTER_TYPE_P (TREE_TYPE (lhs)) |
2296 | || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs))) | |
5f57a8b1 | 2297 | != TYPE_MAIN_VARIANT (cfun_va_list)) |
8a58ed0a | 2298 | return NULL_TREE; |
2299 | ||
389dd41b | 2300 | lhs = build_fold_indirect_ref_loc (loc, lhs); |
75a70cf9 | 2301 | rhs = gimple_call_arg (call, 1); |
8a58ed0a | 2302 | if (TYPE_MAIN_VARIANT (TREE_TYPE (rhs)) |
5f57a8b1 | 2303 | != TYPE_MAIN_VARIANT (cfun_va_list)) |
8a58ed0a | 2304 | return NULL_TREE; |
2305 | ||
389dd41b | 2306 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); |
8a58ed0a | 2307 | return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs); |
2308 | ||
2309 | case BUILT_IN_VA_END: | |
75a70cf9 | 2310 | /* No effect, so the statement will be deleted. */ |
8a58ed0a | 2311 | return integer_zero_node; |
2312 | ||
2313 | default: | |
2314 | gcc_unreachable (); | |
2315 | } | |
2316 | } | |
75a70cf9 | 2317 | |
f87df69a | 2318 | /* Attemp to make the block of __builtin_unreachable I unreachable by changing |
2319 | the incoming jumps. Return true if at least one jump was changed. */ | |
2320 | ||
2321 | static bool | |
2322 | optimize_unreachable (gimple_stmt_iterator i) | |
2323 | { | |
2324 | basic_block bb = gsi_bb (i); | |
2325 | gimple_stmt_iterator gsi; | |
2326 | gimple stmt; | |
2327 | edge_iterator ei; | |
2328 | edge e; | |
2329 | bool ret; | |
2330 | ||
2331 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
2332 | { | |
2333 | stmt = gsi_stmt (gsi); | |
2334 | ||
2335 | if (is_gimple_debug (stmt)) | |
2336 | continue; | |
2337 | ||
2338 | if (gimple_code (stmt) == GIMPLE_LABEL) | |
2339 | { | |
2340 | /* Verify we do not need to preserve the label. */ | |
2341 | if (FORCED_LABEL (gimple_label_label (stmt))) | |
2342 | return false; | |
2343 | ||
2344 | continue; | |
2345 | } | |
2346 | ||
2347 | /* Only handle the case that __builtin_unreachable is the first statement | |
2348 | in the block. We rely on DCE to remove stmts without side-effects | |
2349 | before __builtin_unreachable. */ | |
2350 | if (gsi_stmt (gsi) != gsi_stmt (i)) | |
2351 | return false; | |
2352 | } | |
2353 | ||
2354 | ret = false; | |
2355 | FOR_EACH_EDGE (e, ei, bb->preds) | |
2356 | { | |
2357 | gsi = gsi_last_bb (e->src); | |
522f73a1 | 2358 | if (gsi_end_p (gsi)) |
2359 | continue; | |
f87df69a | 2360 | |
522f73a1 | 2361 | stmt = gsi_stmt (gsi); |
2362 | if (gimple_code (stmt) == GIMPLE_COND) | |
f87df69a | 2363 | { |
2364 | if (e->flags & EDGE_TRUE_VALUE) | |
2365 | gimple_cond_make_false (stmt); | |
2366 | else if (e->flags & EDGE_FALSE_VALUE) | |
2367 | gimple_cond_make_true (stmt); | |
2368 | else | |
2369 | gcc_unreachable (); | |
2370 | } | |
2371 | else | |
2372 | { | |
2373 | /* Todo: handle other cases, f.i. switch statement. */ | |
2374 | continue; | |
2375 | } | |
2376 | ||
2377 | ret = true; | |
2378 | } | |
2379 | ||
2380 | return ret; | |
2381 | } | |
2382 | ||
4ee9c684 | 2383 | /* A simple pass that attempts to fold all builtin functions. This pass |
2384 | is run after we've propagated as many constants as we can. */ | |
2385 | ||
2a1990e9 | 2386 | static unsigned int |
4ee9c684 | 2387 | execute_fold_all_builtins (void) |
2388 | { | |
b36237eb | 2389 | bool cfg_changed = false; |
4ee9c684 | 2390 | basic_block bb; |
b1b7c0c4 | 2391 | unsigned int todoflags = 0; |
48e1416a | 2392 | |
4ee9c684 | 2393 | FOR_EACH_BB (bb) |
2394 | { | |
75a70cf9 | 2395 | gimple_stmt_iterator i; |
2396 | for (i = gsi_start_bb (bb); !gsi_end_p (i); ) | |
4ee9c684 | 2397 | { |
75a70cf9 | 2398 | gimple stmt, old_stmt; |
4ee9c684 | 2399 | tree callee, result; |
0a39fd54 | 2400 | enum built_in_function fcode; |
4ee9c684 | 2401 | |
75a70cf9 | 2402 | stmt = gsi_stmt (i); |
2403 | ||
2404 | if (gimple_code (stmt) != GIMPLE_CALL) | |
0a39fd54 | 2405 | { |
75a70cf9 | 2406 | gsi_next (&i); |
0a39fd54 | 2407 | continue; |
2408 | } | |
75a70cf9 | 2409 | callee = gimple_call_fndecl (stmt); |
4ee9c684 | 2410 | if (!callee || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL) |
0a39fd54 | 2411 | { |
75a70cf9 | 2412 | gsi_next (&i); |
0a39fd54 | 2413 | continue; |
2414 | } | |
2415 | fcode = DECL_FUNCTION_CODE (callee); | |
4ee9c684 | 2416 | |
2d18b16d | 2417 | result = gimple_fold_builtin (stmt); |
5a4b7e1e | 2418 | |
2419 | if (result) | |
75a70cf9 | 2420 | gimple_remove_stmt_histograms (cfun, stmt); |
5a4b7e1e | 2421 | |
4ee9c684 | 2422 | if (!result) |
2423 | switch (DECL_FUNCTION_CODE (callee)) | |
2424 | { | |
2425 | case BUILT_IN_CONSTANT_P: | |
2426 | /* Resolve __builtin_constant_p. If it hasn't been | |
2427 | folded to integer_one_node by now, it's fairly | |
2428 | certain that the value simply isn't constant. */ | |
75a70cf9 | 2429 | result = integer_zero_node; |
4ee9c684 | 2430 | break; |
2431 | ||
fca0886c | 2432 | case BUILT_IN_ASSUME_ALIGNED: |
2433 | /* Remove __builtin_assume_aligned. */ | |
2434 | result = gimple_call_arg (stmt, 0); | |
2435 | break; | |
2436 | ||
bdd0e199 | 2437 | case BUILT_IN_STACK_RESTORE: |
75a70cf9 | 2438 | result = optimize_stack_restore (i); |
8a58ed0a | 2439 | if (result) |
2440 | break; | |
75a70cf9 | 2441 | gsi_next (&i); |
8a58ed0a | 2442 | continue; |
2443 | ||
f87df69a | 2444 | case BUILT_IN_UNREACHABLE: |
2445 | if (optimize_unreachable (i)) | |
2446 | cfg_changed = true; | |
2447 | break; | |
2448 | ||
8a58ed0a | 2449 | case BUILT_IN_VA_START: |
2450 | case BUILT_IN_VA_END: | |
2451 | case BUILT_IN_VA_COPY: | |
2452 | /* These shouldn't be folded before pass_stdarg. */ | |
75a70cf9 | 2453 | result = optimize_stdarg_builtin (stmt); |
bdd0e199 | 2454 | if (result) |
2455 | break; | |
2456 | /* FALLTHRU */ | |
2457 | ||
4ee9c684 | 2458 | default: |
75a70cf9 | 2459 | gsi_next (&i); |
4ee9c684 | 2460 | continue; |
2461 | } | |
2462 | ||
f87df69a | 2463 | if (result == NULL_TREE) |
2464 | break; | |
2465 | ||
4ee9c684 | 2466 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2467 | { | |
2468 | fprintf (dump_file, "Simplified\n "); | |
75a70cf9 | 2469 | print_gimple_stmt (dump_file, stmt, 0, dump_flags); |
4ee9c684 | 2470 | } |
2471 | ||
75a70cf9 | 2472 | old_stmt = stmt; |
75a70cf9 | 2473 | if (!update_call_from_tree (&i, result)) |
0fefde02 | 2474 | { |
2475 | gimplify_and_update_call_from_tree (&i, result); | |
2476 | todoflags |= TODO_update_address_taken; | |
2477 | } | |
de6ed584 | 2478 | |
75a70cf9 | 2479 | stmt = gsi_stmt (i); |
4c5fd53c | 2480 | update_stmt (stmt); |
de6ed584 | 2481 | |
75a70cf9 | 2482 | if (maybe_clean_or_replace_eh_stmt (old_stmt, stmt) |
2483 | && gimple_purge_dead_eh_edges (bb)) | |
b36237eb | 2484 | cfg_changed = true; |
4ee9c684 | 2485 | |
2486 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2487 | { | |
2488 | fprintf (dump_file, "to\n "); | |
75a70cf9 | 2489 | print_gimple_stmt (dump_file, stmt, 0, dump_flags); |
4ee9c684 | 2490 | fprintf (dump_file, "\n"); |
2491 | } | |
0a39fd54 | 2492 | |
2493 | /* Retry the same statement if it changed into another | |
2494 | builtin, there might be new opportunities now. */ | |
75a70cf9 | 2495 | if (gimple_code (stmt) != GIMPLE_CALL) |
0a39fd54 | 2496 | { |
75a70cf9 | 2497 | gsi_next (&i); |
0a39fd54 | 2498 | continue; |
2499 | } | |
75a70cf9 | 2500 | callee = gimple_call_fndecl (stmt); |
0a39fd54 | 2501 | if (!callee |
75a70cf9 | 2502 | || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL |
0a39fd54 | 2503 | || DECL_FUNCTION_CODE (callee) == fcode) |
75a70cf9 | 2504 | gsi_next (&i); |
4ee9c684 | 2505 | } |
2506 | } | |
48e1416a | 2507 | |
b36237eb | 2508 | /* Delete unreachable blocks. */ |
b1b7c0c4 | 2509 | if (cfg_changed) |
2510 | todoflags |= TODO_cleanup_cfg; | |
48e1416a | 2511 | |
b1b7c0c4 | 2512 | return todoflags; |
4ee9c684 | 2513 | } |
2514 | ||
41511585 | 2515 | |
48e1416a | 2516 | struct gimple_opt_pass pass_fold_builtins = |
4ee9c684 | 2517 | { |
20099e35 | 2518 | { |
2519 | GIMPLE_PASS, | |
4ee9c684 | 2520 | "fab", /* name */ |
2521 | NULL, /* gate */ | |
2522 | execute_fold_all_builtins, /* execute */ | |
2523 | NULL, /* sub */ | |
2524 | NULL, /* next */ | |
2525 | 0, /* static_pass_number */ | |
0b1615c1 | 2526 | TV_NONE, /* tv_id */ |
49290934 | 2527 | PROP_cfg | PROP_ssa, /* properties_required */ |
4ee9c684 | 2528 | 0, /* properties_provided */ |
2529 | 0, /* properties_destroyed */ | |
2530 | 0, /* todo_flags_start */ | |
771e2890 | 2531 | TODO_verify_ssa |
20099e35 | 2532 | | TODO_update_ssa /* todo_flags_finish */ |
2533 | } | |
4ee9c684 | 2534 | }; |