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6de9cd9a | 1 | /* Conditional constant propagation pass for the GNU compiler. |
1cdaa211 | 2 | Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, |
45a5b21a | 3 | 2010, 2011, 2012 Free Software Foundation, Inc. |
6de9cd9a DN |
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. | |
b8698a0f | 8 | |
6de9cd9a DN |
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 | |
9dcd6f09 | 11 | Free Software Foundation; either version 3, or (at your option) any |
6de9cd9a | 12 | later version. |
b8698a0f | 13 | |
6de9cd9a DN |
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. | |
b8698a0f | 18 | |
6de9cd9a | 19 | You should have received a copy of the GNU General Public License |
9dcd6f09 NC |
20 | along with GCC; see the file COPYING3. If not see |
21 | <http://www.gnu.org/licenses/>. */ | |
6de9cd9a | 22 | |
0bca51f0 DN |
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 | ||
106dec71 ZD |
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. | |
0bca51f0 DN |
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. | |
b8698a0f | 66 | |
0bca51f0 DN |
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 | ||
6de9cd9a DN |
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" | |
6de9cd9a | 117 | #include "tree.h" |
750628d8 | 118 | #include "flags.h" |
6de9cd9a | 119 | #include "tm_p.h" |
6de9cd9a | 120 | #include "basic-block.h" |
750628d8 | 121 | #include "function.h" |
cf835838 | 122 | #include "gimple-pretty-print.h" |
750628d8 | 123 | #include "tree-flow.h" |
6de9cd9a | 124 | #include "tree-pass.h" |
750628d8 | 125 | #include "tree-ssa-propagate.h" |
53a8f709 | 126 | #include "value-prof.h" |
750628d8 | 127 | #include "langhooks.h" |
ae3df618 | 128 | #include "target.h" |
718f9c0f | 129 | #include "diagnostic-core.h" |
74fe548b | 130 | #include "dbgcnt.h" |
cfef45c8 | 131 | #include "gimple-fold.h" |
1fed1006 | 132 | #include "params.h" |
0823efed | 133 | #include "hash-table.h" |
6de9cd9a DN |
134 | |
135 | ||
136 | /* Possible lattice values. */ | |
137 | typedef enum | |
138 | { | |
106dec71 | 139 | UNINITIALIZED, |
6de9cd9a DN |
140 | UNDEFINED, |
141 | CONSTANT, | |
142 | VARYING | |
0bca51f0 | 143 | } ccp_lattice_t; |
6de9cd9a | 144 | |
455e6d5b RG |
145 | struct prop_value_d { |
146 | /* Lattice value. */ | |
147 | ccp_lattice_t lattice_val; | |
148 | ||
149 | /* Propagated value. */ | |
150 | tree value; | |
0b4b14ac RG |
151 | |
152 | /* Mask that applies to the propagated value during CCP. For | |
153 | X with a CONSTANT lattice value X & ~mask == value & ~mask. */ | |
154 | double_int mask; | |
455e6d5b RG |
155 | }; |
156 | ||
157 | typedef struct prop_value_d prop_value_t; | |
158 | ||
0bca51f0 DN |
159 | /* Array of propagated constant values. After propagation, |
160 | CONST_VAL[I].VALUE holds the constant value for SSA_NAME(I). If | |
161 | the constant is held in an SSA name representing a memory store | |
38635499 DN |
162 | (i.e., a VDEF), CONST_VAL[I].MEM_REF will contain the actual |
163 | memory reference used to store (i.e., the LHS of the assignment | |
164 | doing the store). */ | |
404f4351 | 165 | static prop_value_t *const_val; |
6de9cd9a | 166 | |
25e20805 | 167 | static void canonicalize_float_value (prop_value_t *); |
f61e18ec | 168 | static bool ccp_fold_stmt (gimple_stmt_iterator *); |
25e20805 | 169 | |
0bca51f0 | 170 | /* Dump constant propagation value VAL to file OUTF prefixed by PREFIX. */ |
95eec0d6 DB |
171 | |
172 | static void | |
0bca51f0 | 173 | dump_lattice_value (FILE *outf, const char *prefix, prop_value_t val) |
95eec0d6 | 174 | { |
750628d8 | 175 | switch (val.lattice_val) |
95eec0d6 | 176 | { |
0bca51f0 DN |
177 | case UNINITIALIZED: |
178 | fprintf (outf, "%sUNINITIALIZED", prefix); | |
179 | break; | |
750628d8 DN |
180 | case UNDEFINED: |
181 | fprintf (outf, "%sUNDEFINED", prefix); | |
182 | break; | |
183 | case VARYING: | |
184 | fprintf (outf, "%sVARYING", prefix); | |
185 | break; | |
750628d8 DN |
186 | case CONSTANT: |
187 | fprintf (outf, "%sCONSTANT ", prefix); | |
0b4b14ac RG |
188 | if (TREE_CODE (val.value) != INTEGER_CST |
189 | || double_int_zero_p (val.mask)) | |
190 | print_generic_expr (outf, val.value, dump_flags); | |
191 | else | |
192 | { | |
193 | double_int cval = double_int_and_not (tree_to_double_int (val.value), | |
194 | val.mask); | |
195 | fprintf (outf, "%sCONSTANT " HOST_WIDE_INT_PRINT_DOUBLE_HEX, | |
196 | prefix, cval.high, cval.low); | |
197 | fprintf (outf, " (" HOST_WIDE_INT_PRINT_DOUBLE_HEX ")", | |
198 | val.mask.high, val.mask.low); | |
199 | } | |
750628d8 DN |
200 | break; |
201 | default: | |
1e128c5f | 202 | gcc_unreachable (); |
750628d8 | 203 | } |
95eec0d6 | 204 | } |
6de9cd9a | 205 | |
6de9cd9a | 206 | |
0bca51f0 DN |
207 | /* Print lattice value VAL to stderr. */ |
208 | ||
209 | void debug_lattice_value (prop_value_t val); | |
210 | ||
24e47c76 | 211 | DEBUG_FUNCTION void |
0bca51f0 DN |
212 | debug_lattice_value (prop_value_t val) |
213 | { | |
214 | dump_lattice_value (stderr, "", val); | |
215 | fprintf (stderr, "\n"); | |
216 | } | |
6de9cd9a | 217 | |
6de9cd9a | 218 | |
0bca51f0 DN |
219 | /* Compute a default value for variable VAR and store it in the |
220 | CONST_VAL array. The following rules are used to get default | |
221 | values: | |
95eec0d6 | 222 | |
0bca51f0 DN |
223 | 1- Global and static variables that are declared constant are |
224 | considered CONSTANT. | |
225 | ||
226 | 2- Any other value is considered UNDEFINED. This is useful when | |
750628d8 DN |
227 | considering PHI nodes. PHI arguments that are undefined do not |
228 | change the constant value of the PHI node, which allows for more | |
0bca51f0 | 229 | constants to be propagated. |
6de9cd9a | 230 | |
caf55296 | 231 | 3- Variables defined by statements other than assignments and PHI |
0bca51f0 | 232 | nodes are considered VARYING. |
6de9cd9a | 233 | |
caf55296 | 234 | 4- Initial values of variables that are not GIMPLE registers are |
106dec71 | 235 | considered VARYING. */ |
6de9cd9a | 236 | |
0bca51f0 DN |
237 | static prop_value_t |
238 | get_default_value (tree var) | |
239 | { | |
0b4b14ac | 240 | prop_value_t val = { UNINITIALIZED, NULL_TREE, { 0, 0 } }; |
e8114fba RG |
241 | gimple stmt; |
242 | ||
243 | stmt = SSA_NAME_DEF_STMT (var); | |
244 | ||
245 | if (gimple_nop_p (stmt)) | |
6de9cd9a | 246 | { |
e8114fba RG |
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. */ | |
ea057359 RG |
251 | if (!virtual_operand_p (var) |
252 | && TREE_CODE (SSA_NAME_VAR (var)) == VAR_DECL) | |
e8114fba RG |
253 | val.lattice_val = UNDEFINED; |
254 | else | |
0b4b14ac RG |
255 | { |
256 | val.lattice_val = VARYING; | |
257 | val.mask = double_int_minus_one; | |
258 | } | |
6de9cd9a | 259 | } |
e8114fba RG |
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) | |
750628d8 | 266 | { |
e8114fba RG |
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)))) | |
0bca51f0 | 271 | { |
e8114fba RG |
272 | val.lattice_val = CONSTANT; |
273 | val.value = cst; | |
0bca51f0 DN |
274 | } |
275 | else | |
e8114fba RG |
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; | |
0b4b14ac | 284 | val.mask = double_int_minus_one; |
750628d8 | 285 | } |
6de9cd9a | 286 | |
750628d8 DN |
287 | return val; |
288 | } | |
6de9cd9a | 289 | |
6de9cd9a | 290 | |
106dec71 | 291 | /* Get the constant value associated with variable VAR. */ |
6de9cd9a | 292 | |
106dec71 ZD |
293 | static inline prop_value_t * |
294 | get_value (tree var) | |
0bca51f0 | 295 | { |
ed97ddc6 | 296 | prop_value_t *val; |
106dec71 | 297 | |
ed97ddc6 RG |
298 | if (const_val == NULL) |
299 | return NULL; | |
300 | ||
301 | val = &const_val[SSA_NAME_VERSION (var)]; | |
106dec71 | 302 | if (val->lattice_val == UNINITIALIZED) |
6de9cd9a DN |
303 | *val = get_default_value (var); |
304 | ||
25e20805 RG |
305 | canonicalize_float_value (val); |
306 | ||
6de9cd9a DN |
307 | return val; |
308 | } | |
309 | ||
84d77ca6 RG |
310 | /* Return the constant tree value associated with VAR. */ |
311 | ||
312 | static inline tree | |
313 | get_constant_value (tree var) | |
314 | { | |
e196b221 JH |
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); | |
0b4b14ac RG |
323 | if (val |
324 | && val->lattice_val == CONSTANT | |
325 | && (TREE_CODE (val->value) != INTEGER_CST | |
326 | || double_int_zero_p (val->mask))) | |
84d77ca6 RG |
327 | return val->value; |
328 | return NULL_TREE; | |
329 | } | |
330 | ||
106dec71 ZD |
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; | |
0b4b14ac | 340 | val->mask = double_int_minus_one; |
106dec71 | 341 | } |
6de9cd9a | 342 | |
fbb5445b L |
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; | |
fbb5445b L |
386 | return; |
387 | } | |
388 | } | |
389 | ||
0b4b14ac RG |
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 | ||
95cbf851 RG |
408 | /* Allow transitioning from PHI <&x, not executable> == &x |
409 | to PHI <&x, &y> == common alignment. */ | |
0b4b14ac RG |
410 | if (TREE_CODE (old_val.value) != INTEGER_CST |
411 | && TREE_CODE (new_val.value) == INTEGER_CST) | |
412 | return true; | |
413 | ||
414 | /* Bit-lattices have to agree in the still valid bits. */ | |
415 | if (TREE_CODE (old_val.value) == INTEGER_CST | |
416 | && TREE_CODE (new_val.value) == INTEGER_CST) | |
417 | return double_int_equal_p | |
418 | (double_int_and_not (tree_to_double_int (old_val.value), | |
419 | new_val.mask), | |
420 | double_int_and_not (tree_to_double_int (new_val.value), | |
421 | new_val.mask)); | |
422 | ||
423 | /* Otherwise constant values have to agree. */ | |
424 | return operand_equal_p (old_val.value, new_val.value, 0); | |
425 | } | |
426 | ||
0bca51f0 DN |
427 | /* Set the value for variable VAR to NEW_VAL. Return true if the new |
428 | value is different from VAR's previous value. */ | |
6de9cd9a | 429 | |
750628d8 | 430 | static bool |
0bca51f0 | 431 | set_lattice_value (tree var, prop_value_t new_val) |
6de9cd9a | 432 | { |
7a95d078 RG |
433 | /* We can deal with old UNINITIALIZED values just fine here. */ |
434 | prop_value_t *old_val = &const_val[SSA_NAME_VERSION (var)]; | |
0bca51f0 | 435 | |
fbb5445b L |
436 | canonicalize_float_value (&new_val); |
437 | ||
0b4b14ac RG |
438 | /* We have to be careful to not go up the bitwise lattice |
439 | represented by the mask. | |
440 | ??? This doesn't seem to be the best place to enforce this. */ | |
441 | if (new_val.lattice_val == CONSTANT | |
442 | && old_val->lattice_val == CONSTANT | |
443 | && TREE_CODE (new_val.value) == INTEGER_CST | |
444 | && TREE_CODE (old_val->value) == INTEGER_CST) | |
445 | { | |
446 | double_int diff; | |
447 | diff = double_int_xor (tree_to_double_int (new_val.value), | |
448 | tree_to_double_int (old_val->value)); | |
449 | new_val.mask = double_int_ior (new_val.mask, | |
450 | double_int_ior (old_val->mask, diff)); | |
451 | } | |
106dec71 | 452 | |
0b4b14ac | 453 | gcc_assert (valid_lattice_transition (*old_val, new_val)); |
0bca51f0 | 454 | |
0b4b14ac RG |
455 | /* If *OLD_VAL and NEW_VAL are the same, return false to inform the |
456 | caller that this was a non-transition. */ | |
457 | if (old_val->lattice_val != new_val.lattice_val | |
458 | || (new_val.lattice_val == CONSTANT | |
459 | && TREE_CODE (new_val.value) == INTEGER_CST | |
460 | && (TREE_CODE (old_val->value) != INTEGER_CST | |
461 | || !double_int_equal_p (new_val.mask, old_val->mask)))) | |
6de9cd9a | 462 | { |
0b4b14ac RG |
463 | /* ??? We would like to delay creation of INTEGER_CSTs from |
464 | partially constants here. */ | |
465 | ||
750628d8 DN |
466 | if (dump_file && (dump_flags & TDF_DETAILS)) |
467 | { | |
0bca51f0 | 468 | dump_lattice_value (dump_file, "Lattice value changed to ", new_val); |
106dec71 | 469 | fprintf (dump_file, ". Adding SSA edges to worklist.\n"); |
750628d8 DN |
470 | } |
471 | ||
0bca51f0 DN |
472 | *old_val = new_val; |
473 | ||
7a95d078 | 474 | gcc_assert (new_val.lattice_val != UNINITIALIZED); |
106dec71 | 475 | return true; |
6de9cd9a | 476 | } |
750628d8 DN |
477 | |
478 | return false; | |
6de9cd9a DN |
479 | } |
480 | ||
0b4b14ac RG |
481 | static prop_value_t get_value_for_expr (tree, bool); |
482 | static prop_value_t bit_value_binop (enum tree_code, tree, tree, tree); | |
483 | static void bit_value_binop_1 (enum tree_code, tree, double_int *, double_int *, | |
484 | tree, double_int, double_int, | |
485 | tree, double_int, double_int); | |
486 | ||
487 | /* Return a double_int that can be used for bitwise simplifications | |
488 | from VAL. */ | |
489 | ||
490 | static double_int | |
491 | value_to_double_int (prop_value_t val) | |
492 | { | |
493 | if (val.value | |
494 | && TREE_CODE (val.value) == INTEGER_CST) | |
495 | return tree_to_double_int (val.value); | |
496 | else | |
497 | return double_int_zero; | |
498 | } | |
499 | ||
500 | /* Return the value for the address expression EXPR based on alignment | |
501 | information. */ | |
7a95d078 RG |
502 | |
503 | static prop_value_t | |
0b4b14ac RG |
504 | get_value_from_alignment (tree expr) |
505 | { | |
d1f4e15f | 506 | tree type = TREE_TYPE (expr); |
0b4b14ac | 507 | prop_value_t val; |
d1f4e15f RG |
508 | unsigned HOST_WIDE_INT bitpos; |
509 | unsigned int align; | |
0b4b14ac RG |
510 | |
511 | gcc_assert (TREE_CODE (expr) == ADDR_EXPR); | |
512 | ||
a0969677 | 513 | get_pointer_alignment_1 (expr, &align, &bitpos); |
d1f4e15f RG |
514 | val.mask |
515 | = double_int_and_not (POINTER_TYPE_P (type) || TYPE_UNSIGNED (type) | |
516 | ? double_int_mask (TYPE_PRECISION (type)) | |
517 | : double_int_minus_one, | |
518 | uhwi_to_double_int (align / BITS_PER_UNIT - 1)); | |
519 | val.lattice_val = double_int_minus_one_p (val.mask) ? VARYING : CONSTANT; | |
520 | if (val.lattice_val == CONSTANT) | |
521 | val.value | |
522 | = double_int_to_tree (type, uhwi_to_double_int (bitpos / BITS_PER_UNIT)); | |
0b4b14ac | 523 | else |
d1f4e15f | 524 | val.value = NULL_TREE; |
0b4b14ac RG |
525 | |
526 | return val; | |
527 | } | |
528 | ||
529 | /* Return the value for the tree operand EXPR. If FOR_BITS_P is true | |
530 | return constant bits extracted from alignment information for | |
531 | invariant addresses. */ | |
532 | ||
533 | static prop_value_t | |
534 | get_value_for_expr (tree expr, bool for_bits_p) | |
7a95d078 RG |
535 | { |
536 | prop_value_t val; | |
537 | ||
538 | if (TREE_CODE (expr) == SSA_NAME) | |
0b4b14ac RG |
539 | { |
540 | val = *get_value (expr); | |
541 | if (for_bits_p | |
542 | && val.lattice_val == CONSTANT | |
543 | && TREE_CODE (val.value) == ADDR_EXPR) | |
544 | val = get_value_from_alignment (val.value); | |
545 | } | |
546 | else if (is_gimple_min_invariant (expr) | |
547 | && (!for_bits_p || TREE_CODE (expr) != ADDR_EXPR)) | |
7a95d078 RG |
548 | { |
549 | val.lattice_val = CONSTANT; | |
550 | val.value = expr; | |
0b4b14ac | 551 | val.mask = double_int_zero; |
7a95d078 RG |
552 | canonicalize_float_value (&val); |
553 | } | |
0b4b14ac RG |
554 | else if (TREE_CODE (expr) == ADDR_EXPR) |
555 | val = get_value_from_alignment (expr); | |
7a95d078 RG |
556 | else |
557 | { | |
558 | val.lattice_val = VARYING; | |
0b4b14ac | 559 | val.mask = double_int_minus_one; |
7a95d078 RG |
560 | val.value = NULL_TREE; |
561 | } | |
7a95d078 RG |
562 | return val; |
563 | } | |
564 | ||
0bca51f0 | 565 | /* Return the likely CCP lattice value for STMT. |
6de9cd9a | 566 | |
750628d8 | 567 | If STMT has no operands, then return CONSTANT. |
6de9cd9a | 568 | |
7f879c96 RG |
569 | Else if undefinedness of operands of STMT cause its value to be |
570 | undefined, then return UNDEFINED. | |
6de9cd9a | 571 | |
750628d8 | 572 | Else if any operands of STMT are constants, then return CONSTANT. |
6de9cd9a | 573 | |
750628d8 | 574 | Else return VARYING. */ |
6de9cd9a | 575 | |
0bca51f0 | 576 | static ccp_lattice_t |
726a989a | 577 | likely_value (gimple stmt) |
750628d8 | 578 | { |
7f879c96 | 579 | bool has_constant_operand, has_undefined_operand, all_undefined_operands; |
750628d8 DN |
580 | tree use; |
581 | ssa_op_iter iter; | |
e8114fba | 582 | unsigned i; |
6de9cd9a | 583 | |
e0c68ce9 | 584 | enum gimple_code code = gimple_code (stmt); |
726a989a RB |
585 | |
586 | /* This function appears to be called only for assignments, calls, | |
587 | conditionals, and switches, due to the logic in visit_stmt. */ | |
588 | gcc_assert (code == GIMPLE_ASSIGN | |
589 | || code == GIMPLE_CALL | |
590 | || code == GIMPLE_COND | |
591 | || code == GIMPLE_SWITCH); | |
0bca51f0 DN |
592 | |
593 | /* If the statement has volatile operands, it won't fold to a | |
594 | constant value. */ | |
726a989a | 595 | if (gimple_has_volatile_ops (stmt)) |
0bca51f0 DN |
596 | return VARYING; |
597 | ||
726a989a | 598 | /* Arrive here for more complex cases. */ |
106dec71 | 599 | has_constant_operand = false; |
7f879c96 RG |
600 | has_undefined_operand = false; |
601 | all_undefined_operands = true; | |
e8114fba | 602 | FOR_EACH_SSA_TREE_OPERAND (use, stmt, iter, SSA_OP_USE) |
750628d8 | 603 | { |
106dec71 | 604 | prop_value_t *val = get_value (use); |
750628d8 | 605 | |
106dec71 | 606 | if (val->lattice_val == UNDEFINED) |
7f879c96 RG |
607 | has_undefined_operand = true; |
608 | else | |
609 | all_undefined_operands = false; | |
0bca51f0 | 610 | |
750628d8 | 611 | if (val->lattice_val == CONSTANT) |
106dec71 | 612 | has_constant_operand = true; |
6de9cd9a | 613 | } |
750628d8 | 614 | |
5006671f RG |
615 | /* There may be constants in regular rhs operands. For calls we |
616 | have to ignore lhs, fndecl and static chain, otherwise only | |
617 | the lhs. */ | |
618 | for (i = (is_gimple_call (stmt) ? 2 : 0) + gimple_has_lhs (stmt); | |
e8114fba RG |
619 | i < gimple_num_ops (stmt); ++i) |
620 | { | |
621 | tree op = gimple_op (stmt, i); | |
622 | if (!op || TREE_CODE (op) == SSA_NAME) | |
623 | continue; | |
624 | if (is_gimple_min_invariant (op)) | |
625 | has_constant_operand = true; | |
626 | } | |
627 | ||
1cdaa211 RG |
628 | if (has_constant_operand) |
629 | all_undefined_operands = false; | |
630 | ||
7f879c96 RG |
631 | /* If the operation combines operands like COMPLEX_EXPR make sure to |
632 | not mark the result UNDEFINED if only one part of the result is | |
633 | undefined. */ | |
726a989a | 634 | if (has_undefined_operand && all_undefined_operands) |
7f879c96 | 635 | return UNDEFINED; |
726a989a | 636 | else if (code == GIMPLE_ASSIGN && has_undefined_operand) |
7f879c96 | 637 | { |
726a989a | 638 | switch (gimple_assign_rhs_code (stmt)) |
7f879c96 RG |
639 | { |
640 | /* Unary operators are handled with all_undefined_operands. */ | |
641 | case PLUS_EXPR: | |
642 | case MINUS_EXPR: | |
7f879c96 | 643 | case POINTER_PLUS_EXPR: |
7f879c96 RG |
644 | /* Not MIN_EXPR, MAX_EXPR. One VARYING operand may be selected. |
645 | Not bitwise operators, one VARYING operand may specify the | |
646 | result completely. Not logical operators for the same reason. | |
0cedb9e9 RG |
647 | Not COMPLEX_EXPR as one VARYING operand makes the result partly |
648 | not UNDEFINED. Not *DIV_EXPR, comparisons and shifts because | |
649 | the undefined operand may be promoted. */ | |
7f879c96 RG |
650 | return UNDEFINED; |
651 | ||
95cbf851 RG |
652 | case ADDR_EXPR: |
653 | /* If any part of an address is UNDEFINED, like the index | |
654 | of an ARRAY_EXPR, then treat the result as UNDEFINED. */ | |
655 | return UNDEFINED; | |
656 | ||
7f879c96 RG |
657 | default: |
658 | ; | |
659 | } | |
660 | } | |
661 | /* If there was an UNDEFINED operand but the result may be not UNDEFINED | |
6ad024b4 RG |
662 | fall back to CONSTANT. During iteration UNDEFINED may still drop |
663 | to CONSTANT. */ | |
7f879c96 | 664 | if (has_undefined_operand) |
6ad024b4 | 665 | return CONSTANT; |
7f879c96 | 666 | |
e8114fba RG |
667 | /* We do not consider virtual operands here -- load from read-only |
668 | memory may have only VARYING virtual operands, but still be | |
669 | constant. */ | |
106dec71 | 670 | if (has_constant_operand |
e8114fba | 671 | || gimple_references_memory_p (stmt)) |
0bca51f0 DN |
672 | return CONSTANT; |
673 | ||
106dec71 | 674 | return VARYING; |
6de9cd9a DN |
675 | } |
676 | ||
106dec71 ZD |
677 | /* Returns true if STMT cannot be constant. */ |
678 | ||
679 | static bool | |
726a989a | 680 | surely_varying_stmt_p (gimple stmt) |
106dec71 ZD |
681 | { |
682 | /* If the statement has operands that we cannot handle, it cannot be | |
683 | constant. */ | |
726a989a | 684 | if (gimple_has_volatile_ops (stmt)) |
106dec71 ZD |
685 | return true; |
686 | ||
174ef36d RG |
687 | /* If it is a call and does not return a value or is not a |
688 | builtin and not an indirect call, it is varying. */ | |
726a989a | 689 | if (is_gimple_call (stmt)) |
174ef36d RG |
690 | { |
691 | tree fndecl; | |
692 | if (!gimple_call_lhs (stmt) | |
693 | || ((fndecl = gimple_call_fndecl (stmt)) != NULL_TREE | |
99f536cc | 694 | && !DECL_BUILT_IN (fndecl))) |
174ef36d RG |
695 | return true; |
696 | } | |
106dec71 | 697 | |
e8114fba | 698 | /* Any other store operation is not interesting. */ |
5006671f | 699 | else if (gimple_vdef (stmt)) |
e8114fba RG |
700 | return true; |
701 | ||
106dec71 ZD |
702 | /* Anything other than assignments and conditional jumps are not |
703 | interesting for CCP. */ | |
726a989a | 704 | if (gimple_code (stmt) != GIMPLE_ASSIGN |
174ef36d RG |
705 | && gimple_code (stmt) != GIMPLE_COND |
706 | && gimple_code (stmt) != GIMPLE_SWITCH | |
707 | && gimple_code (stmt) != GIMPLE_CALL) | |
106dec71 ZD |
708 | return true; |
709 | ||
710 | return false; | |
711 | } | |
6de9cd9a | 712 | |
750628d8 | 713 | /* Initialize local data structures for CCP. */ |
6de9cd9a DN |
714 | |
715 | static void | |
750628d8 | 716 | ccp_initialize (void) |
6de9cd9a | 717 | { |
750628d8 | 718 | basic_block bb; |
6de9cd9a | 719 | |
b9eae1a9 | 720 | const_val = XCNEWVEC (prop_value_t, num_ssa_names); |
6de9cd9a | 721 | |
750628d8 DN |
722 | /* Initialize simulation flags for PHI nodes and statements. */ |
723 | FOR_EACH_BB (bb) | |
6de9cd9a | 724 | { |
726a989a | 725 | gimple_stmt_iterator i; |
6de9cd9a | 726 | |
726a989a | 727 | for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i)) |
750628d8 | 728 | { |
726a989a | 729 | gimple stmt = gsi_stmt (i); |
cd6ea7a2 RH |
730 | bool is_varying; |
731 | ||
732 | /* If the statement is a control insn, then we do not | |
733 | want to avoid simulating the statement once. Failure | |
734 | to do so means that those edges will never get added. */ | |
735 | if (stmt_ends_bb_p (stmt)) | |
736 | is_varying = false; | |
737 | else | |
738 | is_varying = surely_varying_stmt_p (stmt); | |
6de9cd9a | 739 | |
106dec71 | 740 | if (is_varying) |
750628d8 | 741 | { |
0bca51f0 DN |
742 | tree def; |
743 | ssa_op_iter iter; | |
744 | ||
745 | /* If the statement will not produce a constant, mark | |
746 | all its outputs VARYING. */ | |
747 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS) | |
e8114fba | 748 | set_value_varying (def); |
750628d8 | 749 | } |
726a989a | 750 | prop_set_simulate_again (stmt, !is_varying); |
750628d8 | 751 | } |
6de9cd9a DN |
752 | } |
753 | ||
726a989a RB |
754 | /* Now process PHI nodes. We never clear the simulate_again flag on |
755 | phi nodes, since we do not know which edges are executable yet, | |
756 | except for phi nodes for virtual operands when we do not do store ccp. */ | |
750628d8 | 757 | FOR_EACH_BB (bb) |
6de9cd9a | 758 | { |
726a989a | 759 | gimple_stmt_iterator i; |
750628d8 | 760 | |
726a989a RB |
761 | for (i = gsi_start_phis (bb); !gsi_end_p (i); gsi_next (&i)) |
762 | { | |
763 | gimple phi = gsi_stmt (i); | |
764 | ||
ea057359 | 765 | if (virtual_operand_p (gimple_phi_result (phi))) |
726a989a | 766 | prop_set_simulate_again (phi, false); |
106dec71 | 767 | else |
726a989a | 768 | prop_set_simulate_again (phi, true); |
750628d8 | 769 | } |
6de9cd9a | 770 | } |
750628d8 | 771 | } |
6de9cd9a | 772 | |
74fe548b XDL |
773 | /* Debug count support. Reset the values of ssa names |
774 | VARYING when the total number ssa names analyzed is | |
775 | beyond the debug count specified. */ | |
776 | ||
777 | static void | |
778 | do_dbg_cnt (void) | |
779 | { | |
780 | unsigned i; | |
781 | for (i = 0; i < num_ssa_names; i++) | |
782 | { | |
783 | if (!dbg_cnt (ccp)) | |
784 | { | |
785 | const_val[i].lattice_val = VARYING; | |
0b4b14ac | 786 | const_val[i].mask = double_int_minus_one; |
74fe548b XDL |
787 | const_val[i].value = NULL_TREE; |
788 | } | |
789 | } | |
790 | } | |
791 | ||
6de9cd9a | 792 | |
0bca51f0 | 793 | /* Do final substitution of propagated values, cleanup the flowgraph and |
b8698a0f | 794 | free allocated storage. |
6de9cd9a | 795 | |
3253eafb JH |
796 | Return TRUE when something was optimized. */ |
797 | ||
798 | static bool | |
0bca51f0 | 799 | ccp_finalize (void) |
6de9cd9a | 800 | { |
74fe548b | 801 | bool something_changed; |
1be38ccb | 802 | unsigned i; |
74fe548b XDL |
803 | |
804 | do_dbg_cnt (); | |
1be38ccb RG |
805 | |
806 | /* Derive alignment and misalignment information from partially | |
807 | constant pointers in the lattice. */ | |
808 | for (i = 1; i < num_ssa_names; ++i) | |
809 | { | |
810 | tree name = ssa_name (i); | |
811 | prop_value_t *val; | |
1be38ccb RG |
812 | unsigned int tem, align; |
813 | ||
814 | if (!name | |
815 | || !POINTER_TYPE_P (TREE_TYPE (name))) | |
816 | continue; | |
817 | ||
818 | val = get_value (name); | |
819 | if (val->lattice_val != CONSTANT | |
820 | || TREE_CODE (val->value) != INTEGER_CST) | |
821 | continue; | |
822 | ||
823 | /* Trailing constant bits specify the alignment, trailing value | |
824 | bits the misalignment. */ | |
825 | tem = val->mask.low; | |
826 | align = (tem & -tem); | |
644ffefd MJ |
827 | if (align > 1) |
828 | set_ptr_info_alignment (get_ptr_info (name), align, | |
829 | TREE_INT_CST_LOW (val->value) & (align - 1)); | |
1be38ccb RG |
830 | } |
831 | ||
0bca51f0 | 832 | /* Perform substitutions based on the known constant values. */ |
455e6d5b RG |
833 | something_changed = substitute_and_fold (get_constant_value, |
834 | ccp_fold_stmt, true); | |
6de9cd9a | 835 | |
0bca51f0 | 836 | free (const_val); |
ed97ddc6 | 837 | const_val = NULL; |
3253eafb | 838 | return something_changed;; |
6de9cd9a DN |
839 | } |
840 | ||
841 | ||
0bca51f0 DN |
842 | /* Compute the meet operator between *VAL1 and *VAL2. Store the result |
843 | in VAL1. | |
844 | ||
845 | any M UNDEFINED = any | |
0bca51f0 DN |
846 | any M VARYING = VARYING |
847 | Ci M Cj = Ci if (i == j) | |
848 | Ci M Cj = VARYING if (i != j) | |
106dec71 | 849 | */ |
6de9cd9a DN |
850 | |
851 | static void | |
0bca51f0 | 852 | ccp_lattice_meet (prop_value_t *val1, prop_value_t *val2) |
6de9cd9a | 853 | { |
0bca51f0 | 854 | if (val1->lattice_val == UNDEFINED) |
6de9cd9a | 855 | { |
0bca51f0 DN |
856 | /* UNDEFINED M any = any */ |
857 | *val1 = *val2; | |
750628d8 | 858 | } |
0bca51f0 | 859 | else if (val2->lattice_val == UNDEFINED) |
195da47b | 860 | { |
0bca51f0 DN |
861 | /* any M UNDEFINED = any |
862 | Nothing to do. VAL1 already contains the value we want. */ | |
863 | ; | |
195da47b | 864 | } |
0bca51f0 DN |
865 | else if (val1->lattice_val == VARYING |
866 | || val2->lattice_val == VARYING) | |
750628d8 | 867 | { |
0bca51f0 DN |
868 | /* any M VARYING = VARYING. */ |
869 | val1->lattice_val = VARYING; | |
0b4b14ac | 870 | val1->mask = double_int_minus_one; |
0bca51f0 | 871 | val1->value = NULL_TREE; |
750628d8 | 872 | } |
0b4b14ac RG |
873 | else if (val1->lattice_val == CONSTANT |
874 | && val2->lattice_val == CONSTANT | |
875 | && TREE_CODE (val1->value) == INTEGER_CST | |
876 | && TREE_CODE (val2->value) == INTEGER_CST) | |
877 | { | |
878 | /* Ci M Cj = Ci if (i == j) | |
879 | Ci M Cj = VARYING if (i != j) | |
880 | ||
881 | For INTEGER_CSTs mask unequal bits. If no equal bits remain, | |
882 | drop to varying. */ | |
883 | val1->mask | |
884 | = double_int_ior (double_int_ior (val1->mask, | |
885 | val2->mask), | |
886 | double_int_xor (tree_to_double_int (val1->value), | |
887 | tree_to_double_int (val2->value))); | |
888 | if (double_int_minus_one_p (val1->mask)) | |
889 | { | |
890 | val1->lattice_val = VARYING; | |
891 | val1->value = NULL_TREE; | |
892 | } | |
893 | } | |
0bca51f0 DN |
894 | else if (val1->lattice_val == CONSTANT |
895 | && val2->lattice_val == CONSTANT | |
dce2b2f6 | 896 | && simple_cst_equal (val1->value, val2->value) == 1) |
750628d8 | 897 | { |
0bca51f0 DN |
898 | /* Ci M Cj = Ci if (i == j) |
899 | Ci M Cj = VARYING if (i != j) | |
900 | ||
0b4b14ac RG |
901 | VAL1 already contains the value we want for equivalent values. */ |
902 | } | |
903 | else if (val1->lattice_val == CONSTANT | |
904 | && val2->lattice_val == CONSTANT | |
905 | && (TREE_CODE (val1->value) == ADDR_EXPR | |
906 | || TREE_CODE (val2->value) == ADDR_EXPR)) | |
907 | { | |
908 | /* When not equal addresses are involved try meeting for | |
909 | alignment. */ | |
910 | prop_value_t tem = *val2; | |
911 | if (TREE_CODE (val1->value) == ADDR_EXPR) | |
912 | *val1 = get_value_for_expr (val1->value, true); | |
913 | if (TREE_CODE (val2->value) == ADDR_EXPR) | |
914 | tem = get_value_for_expr (val2->value, true); | |
915 | ccp_lattice_meet (val1, &tem); | |
750628d8 DN |
916 | } |
917 | else | |
918 | { | |
0bca51f0 DN |
919 | /* Any other combination is VARYING. */ |
920 | val1->lattice_val = VARYING; | |
0b4b14ac | 921 | val1->mask = double_int_minus_one; |
0bca51f0 | 922 | val1->value = NULL_TREE; |
750628d8 | 923 | } |
6de9cd9a DN |
924 | } |
925 | ||
926 | ||
750628d8 DN |
927 | /* Loop through the PHI_NODE's parameters for BLOCK and compare their |
928 | lattice values to determine PHI_NODE's lattice value. The value of a | |
0bca51f0 | 929 | PHI node is determined calling ccp_lattice_meet with all the arguments |
750628d8 | 930 | of the PHI node that are incoming via executable edges. */ |
6de9cd9a | 931 | |
750628d8 | 932 | static enum ssa_prop_result |
726a989a | 933 | ccp_visit_phi_node (gimple phi) |
6de9cd9a | 934 | { |
726a989a | 935 | unsigned i; |
0bca51f0 | 936 | prop_value_t *old_val, new_val; |
6de9cd9a | 937 | |
750628d8 | 938 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6de9cd9a | 939 | { |
750628d8 | 940 | fprintf (dump_file, "\nVisiting PHI node: "); |
726a989a | 941 | print_gimple_stmt (dump_file, phi, 0, dump_flags); |
6de9cd9a | 942 | } |
6de9cd9a | 943 | |
726a989a | 944 | old_val = get_value (gimple_phi_result (phi)); |
750628d8 DN |
945 | switch (old_val->lattice_val) |
946 | { | |
947 | case VARYING: | |
0bca51f0 | 948 | return SSA_PROP_VARYING; |
6de9cd9a | 949 | |
750628d8 DN |
950 | case CONSTANT: |
951 | new_val = *old_val; | |
952 | break; | |
6de9cd9a | 953 | |
750628d8 | 954 | case UNDEFINED: |
750628d8 | 955 | new_val.lattice_val = UNDEFINED; |
0bca51f0 | 956 | new_val.value = NULL_TREE; |
750628d8 | 957 | break; |
6de9cd9a | 958 | |
750628d8 | 959 | default: |
1e128c5f | 960 | gcc_unreachable (); |
750628d8 | 961 | } |
6de9cd9a | 962 | |
726a989a | 963 | for (i = 0; i < gimple_phi_num_args (phi); i++) |
750628d8 | 964 | { |
0bca51f0 DN |
965 | /* Compute the meet operator over all the PHI arguments flowing |
966 | through executable edges. */ | |
726a989a | 967 | edge e = gimple_phi_arg_edge (phi, i); |
6de9cd9a | 968 | |
750628d8 DN |
969 | if (dump_file && (dump_flags & TDF_DETAILS)) |
970 | { | |
971 | fprintf (dump_file, | |
972 | "\n Argument #%d (%d -> %d %sexecutable)\n", | |
973 | i, e->src->index, e->dest->index, | |
974 | (e->flags & EDGE_EXECUTABLE) ? "" : "not "); | |
975 | } | |
976 | ||
977 | /* If the incoming edge is executable, Compute the meet operator for | |
978 | the existing value of the PHI node and the current PHI argument. */ | |
979 | if (e->flags & EDGE_EXECUTABLE) | |
980 | { | |
726a989a | 981 | tree arg = gimple_phi_arg (phi, i)->def; |
0b4b14ac | 982 | prop_value_t arg_val = get_value_for_expr (arg, false); |
6de9cd9a | 983 | |
0bca51f0 | 984 | ccp_lattice_meet (&new_val, &arg_val); |
6de9cd9a | 985 | |
750628d8 DN |
986 | if (dump_file && (dump_flags & TDF_DETAILS)) |
987 | { | |
988 | fprintf (dump_file, "\t"); | |
0bca51f0 DN |
989 | print_generic_expr (dump_file, arg, dump_flags); |
990 | dump_lattice_value (dump_file, "\tValue: ", arg_val); | |
750628d8 DN |
991 | fprintf (dump_file, "\n"); |
992 | } | |
6de9cd9a | 993 | |
750628d8 DN |
994 | if (new_val.lattice_val == VARYING) |
995 | break; | |
996 | } | |
997 | } | |
6de9cd9a DN |
998 | |
999 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
750628d8 DN |
1000 | { |
1001 | dump_lattice_value (dump_file, "\n PHI node value: ", new_val); | |
1002 | fprintf (dump_file, "\n\n"); | |
1003 | } | |
1004 | ||
106dec71 | 1005 | /* Make the transition to the new value. */ |
726a989a | 1006 | if (set_lattice_value (gimple_phi_result (phi), new_val)) |
750628d8 DN |
1007 | { |
1008 | if (new_val.lattice_val == VARYING) | |
1009 | return SSA_PROP_VARYING; | |
1010 | else | |
1011 | return SSA_PROP_INTERESTING; | |
1012 | } | |
1013 | else | |
1014 | return SSA_PROP_NOT_INTERESTING; | |
6de9cd9a DN |
1015 | } |
1016 | ||
84d77ca6 | 1017 | /* Return the constant value for OP or OP otherwise. */ |
0354c0c7 BS |
1018 | |
1019 | static tree | |
84d77ca6 | 1020 | valueize_op (tree op) |
0354c0c7 | 1021 | { |
0354c0c7 BS |
1022 | if (TREE_CODE (op) == SSA_NAME) |
1023 | { | |
84d77ca6 RG |
1024 | tree tem = get_constant_value (op); |
1025 | if (tem) | |
1026 | return tem; | |
0354c0c7 BS |
1027 | } |
1028 | return op; | |
1029 | } | |
1030 | ||
750628d8 DN |
1031 | /* CCP specific front-end to the non-destructive constant folding |
1032 | routines. | |
6de9cd9a DN |
1033 | |
1034 | Attempt to simplify the RHS of STMT knowing that one or more | |
1035 | operands are constants. | |
1036 | ||
1037 | If simplification is possible, return the simplified RHS, | |
726a989a | 1038 | otherwise return the original RHS or NULL_TREE. */ |
6de9cd9a DN |
1039 | |
1040 | static tree | |
726a989a | 1041 | ccp_fold (gimple stmt) |
6de9cd9a | 1042 | { |
db3927fb | 1043 | location_t loc = gimple_location (stmt); |
726a989a | 1044 | switch (gimple_code (stmt)) |
0bca51f0 | 1045 | { |
726a989a RB |
1046 | case GIMPLE_COND: |
1047 | { | |
1048 | /* Handle comparison operators that can appear in GIMPLE form. */ | |
84d77ca6 RG |
1049 | tree op0 = valueize_op (gimple_cond_lhs (stmt)); |
1050 | tree op1 = valueize_op (gimple_cond_rhs (stmt)); | |
726a989a | 1051 | enum tree_code code = gimple_cond_code (stmt); |
db3927fb | 1052 | return fold_binary_loc (loc, code, boolean_type_node, op0, op1); |
726a989a | 1053 | } |
6de9cd9a | 1054 | |
726a989a RB |
1055 | case GIMPLE_SWITCH: |
1056 | { | |
84d77ca6 RG |
1057 | /* Return the constant switch index. */ |
1058 | return valueize_op (gimple_switch_index (stmt)); | |
726a989a | 1059 | } |
00d382a8 | 1060 | |
cfef45c8 RG |
1061 | case GIMPLE_ASSIGN: |
1062 | case GIMPLE_CALL: | |
1063 | return gimple_fold_stmt_to_constant_1 (stmt, valueize_op); | |
87e1e42b | 1064 | |
ae3df618 | 1065 | default: |
cfef45c8 | 1066 | gcc_unreachable (); |
ae3df618 | 1067 | } |
ae3df618 | 1068 | } |
726a989a | 1069 | |
0b4b14ac RG |
1070 | /* Apply the operation CODE in type TYPE to the value, mask pair |
1071 | RVAL and RMASK representing a value of type RTYPE and set | |
1072 | the value, mask pair *VAL and *MASK to the result. */ | |
1073 | ||
1074 | static void | |
1075 | bit_value_unop_1 (enum tree_code code, tree type, | |
1076 | double_int *val, double_int *mask, | |
1077 | tree rtype, double_int rval, double_int rmask) | |
1078 | { | |
1079 | switch (code) | |
1080 | { | |
1081 | case BIT_NOT_EXPR: | |
1082 | *mask = rmask; | |
1083 | *val = double_int_not (rval); | |
1084 | break; | |
1085 | ||
1086 | case NEGATE_EXPR: | |
1087 | { | |
1088 | double_int temv, temm; | |
1089 | /* Return ~rval + 1. */ | |
1090 | bit_value_unop_1 (BIT_NOT_EXPR, type, &temv, &temm, type, rval, rmask); | |
1091 | bit_value_binop_1 (PLUS_EXPR, type, val, mask, | |
1092 | type, temv, temm, | |
1093 | type, double_int_one, double_int_zero); | |
1094 | break; | |
1095 | } | |
1096 | ||
1097 | CASE_CONVERT: | |
1098 | { | |
1099 | bool uns; | |
1100 | ||
1101 | /* First extend mask and value according to the original type. */ | |
56099f00 | 1102 | uns = TYPE_UNSIGNED (rtype); |
0b4b14ac RG |
1103 | *mask = double_int_ext (rmask, TYPE_PRECISION (rtype), uns); |
1104 | *val = double_int_ext (rval, TYPE_PRECISION (rtype), uns); | |
1105 | ||
1106 | /* Then extend mask and value according to the target type. */ | |
56099f00 | 1107 | uns = TYPE_UNSIGNED (type); |
0b4b14ac RG |
1108 | *mask = double_int_ext (*mask, TYPE_PRECISION (type), uns); |
1109 | *val = double_int_ext (*val, TYPE_PRECISION (type), uns); | |
1110 | break; | |
1111 | } | |
1112 | ||
1113 | default: | |
1114 | *mask = double_int_minus_one; | |
1115 | break; | |
1116 | } | |
1117 | } | |
1118 | ||
1119 | /* Apply the operation CODE in type TYPE to the value, mask pairs | |
1120 | R1VAL, R1MASK and R2VAL, R2MASK representing a values of type R1TYPE | |
1121 | and R2TYPE and set the value, mask pair *VAL and *MASK to the result. */ | |
1122 | ||
1123 | static void | |
1124 | bit_value_binop_1 (enum tree_code code, tree type, | |
1125 | double_int *val, double_int *mask, | |
1126 | tree r1type, double_int r1val, double_int r1mask, | |
1127 | tree r2type, double_int r2val, double_int r2mask) | |
1128 | { | |
56099f00 | 1129 | bool uns = TYPE_UNSIGNED (type); |
0b4b14ac RG |
1130 | /* Assume we'll get a constant result. Use an initial varying value, |
1131 | we fall back to varying in the end if necessary. */ | |
1132 | *mask = double_int_minus_one; | |
1133 | switch (code) | |
1134 | { | |
1135 | case BIT_AND_EXPR: | |
1136 | /* The mask is constant where there is a known not | |
1137 | set bit, (m1 | m2) & ((v1 | m1) & (v2 | m2)) */ | |
1138 | *mask = double_int_and (double_int_ior (r1mask, r2mask), | |
1139 | double_int_and (double_int_ior (r1val, r1mask), | |
1140 | double_int_ior (r2val, r2mask))); | |
1141 | *val = double_int_and (r1val, r2val); | |
1142 | break; | |
1143 | ||
1144 | case BIT_IOR_EXPR: | |
1145 | /* The mask is constant where there is a known | |
1146 | set bit, (m1 | m2) & ~((v1 & ~m1) | (v2 & ~m2)). */ | |
1147 | *mask = double_int_and_not | |
1148 | (double_int_ior (r1mask, r2mask), | |
1149 | double_int_ior (double_int_and_not (r1val, r1mask), | |
1150 | double_int_and_not (r2val, r2mask))); | |
1151 | *val = double_int_ior (r1val, r2val); | |
1152 | break; | |
1153 | ||
1154 | case BIT_XOR_EXPR: | |
1155 | /* m1 | m2 */ | |
1156 | *mask = double_int_ior (r1mask, r2mask); | |
1157 | *val = double_int_xor (r1val, r2val); | |
1158 | break; | |
1159 | ||
1160 | case LROTATE_EXPR: | |
1161 | case RROTATE_EXPR: | |
1162 | if (double_int_zero_p (r2mask)) | |
1163 | { | |
1164 | HOST_WIDE_INT shift = r2val.low; | |
1165 | if (code == RROTATE_EXPR) | |
1166 | shift = -shift; | |
1167 | *mask = double_int_lrotate (r1mask, shift, TYPE_PRECISION (type)); | |
1168 | *val = double_int_lrotate (r1val, shift, TYPE_PRECISION (type)); | |
1169 | } | |
1170 | break; | |
1171 | ||
1172 | case LSHIFT_EXPR: | |
1173 | case RSHIFT_EXPR: | |
1174 | /* ??? We can handle partially known shift counts if we know | |
1175 | its sign. That way we can tell that (x << (y | 8)) & 255 | |
1176 | is zero. */ | |
1177 | if (double_int_zero_p (r2mask)) | |
1178 | { | |
1179 | HOST_WIDE_INT shift = r2val.low; | |
1180 | if (code == RSHIFT_EXPR) | |
1181 | shift = -shift; | |
1182 | /* We need to know if we are doing a left or a right shift | |
1183 | to properly shift in zeros for left shift and unsigned | |
1184 | right shifts and the sign bit for signed right shifts. | |
1185 | For signed right shifts we shift in varying in case | |
1186 | the sign bit was varying. */ | |
1187 | if (shift > 0) | |
1188 | { | |
1189 | *mask = double_int_lshift (r1mask, shift, | |
1190 | TYPE_PRECISION (type), false); | |
1191 | *val = double_int_lshift (r1val, shift, | |
1192 | TYPE_PRECISION (type), false); | |
1193 | } | |
1194 | else if (shift < 0) | |
1195 | { | |
1196 | shift = -shift; | |
1197 | *mask = double_int_rshift (r1mask, shift, | |
1198 | TYPE_PRECISION (type), !uns); | |
1199 | *val = double_int_rshift (r1val, shift, | |
1200 | TYPE_PRECISION (type), !uns); | |
1201 | } | |
1202 | else | |
1203 | { | |
1204 | *mask = r1mask; | |
1205 | *val = r1val; | |
1206 | } | |
1207 | } | |
1208 | break; | |
1209 | ||
1210 | case PLUS_EXPR: | |
1211 | case POINTER_PLUS_EXPR: | |
1212 | { | |
1213 | double_int lo, hi; | |
1214 | /* Do the addition with unknown bits set to zero, to give carry-ins of | |
1215 | zero wherever possible. */ | |
1216 | lo = double_int_add (double_int_and_not (r1val, r1mask), | |
1217 | double_int_and_not (r2val, r2mask)); | |
1218 | lo = double_int_ext (lo, TYPE_PRECISION (type), uns); | |
1219 | /* Do the addition with unknown bits set to one, to give carry-ins of | |
1220 | one wherever possible. */ | |
1221 | hi = double_int_add (double_int_ior (r1val, r1mask), | |
1222 | double_int_ior (r2val, r2mask)); | |
1223 | hi = double_int_ext (hi, TYPE_PRECISION (type), uns); | |
1224 | /* Each bit in the result is known if (a) the corresponding bits in | |
1225 | both inputs are known, and (b) the carry-in to that bit position | |
1226 | is known. We can check condition (b) by seeing if we got the same | |
1227 | result with minimised carries as with maximised carries. */ | |
1228 | *mask = double_int_ior (double_int_ior (r1mask, r2mask), | |
1229 | double_int_xor (lo, hi)); | |
1230 | *mask = double_int_ext (*mask, TYPE_PRECISION (type), uns); | |
1231 | /* It shouldn't matter whether we choose lo or hi here. */ | |
1232 | *val = lo; | |
1233 | break; | |
1234 | } | |
1235 | ||
1236 | case MINUS_EXPR: | |
1237 | { | |
1238 | double_int temv, temm; | |
1239 | bit_value_unop_1 (NEGATE_EXPR, r2type, &temv, &temm, | |
1240 | r2type, r2val, r2mask); | |
1241 | bit_value_binop_1 (PLUS_EXPR, type, val, mask, | |
1242 | r1type, r1val, r1mask, | |
1243 | r2type, temv, temm); | |
1244 | break; | |
1245 | } | |
1246 | ||
1247 | case MULT_EXPR: | |
1248 | { | |
1249 | /* Just track trailing zeros in both operands and transfer | |
1250 | them to the other. */ | |
1251 | int r1tz = double_int_ctz (double_int_ior (r1val, r1mask)); | |
1252 | int r2tz = double_int_ctz (double_int_ior (r2val, r2mask)); | |
1253 | if (r1tz + r2tz >= HOST_BITS_PER_DOUBLE_INT) | |
1254 | { | |
1255 | *mask = double_int_zero; | |
1256 | *val = double_int_zero; | |
1257 | } | |
1258 | else if (r1tz + r2tz > 0) | |
1259 | { | |
1260 | *mask = double_int_not (double_int_mask (r1tz + r2tz)); | |
1261 | *mask = double_int_ext (*mask, TYPE_PRECISION (type), uns); | |
1262 | *val = double_int_zero; | |
1263 | } | |
1264 | break; | |
1265 | } | |
1266 | ||
1267 | case EQ_EXPR: | |
1268 | case NE_EXPR: | |
1269 | { | |
1270 | double_int m = double_int_ior (r1mask, r2mask); | |
1271 | if (!double_int_equal_p (double_int_and_not (r1val, m), | |
1272 | double_int_and_not (r2val, m))) | |
1273 | { | |
1274 | *mask = double_int_zero; | |
1275 | *val = ((code == EQ_EXPR) ? double_int_zero : double_int_one); | |
1276 | } | |
1277 | else | |
1278 | { | |
1279 | /* We know the result of a comparison is always one or zero. */ | |
1280 | *mask = double_int_one; | |
1281 | *val = double_int_zero; | |
1282 | } | |
1283 | break; | |
1284 | } | |
1285 | ||
1286 | case GE_EXPR: | |
1287 | case GT_EXPR: | |
1288 | { | |
1289 | double_int tem = r1val; | |
1290 | r1val = r2val; | |
1291 | r2val = tem; | |
1292 | tem = r1mask; | |
1293 | r1mask = r2mask; | |
1294 | r2mask = tem; | |
1295 | code = swap_tree_comparison (code); | |
1296 | } | |
1297 | /* Fallthru. */ | |
1298 | case LT_EXPR: | |
1299 | case LE_EXPR: | |
1300 | { | |
1301 | int minmax, maxmin; | |
1302 | /* If the most significant bits are not known we know nothing. */ | |
1303 | if (double_int_negative_p (r1mask) || double_int_negative_p (r2mask)) | |
1304 | break; | |
1305 | ||
0425d6f5 | 1306 | /* For comparisons the signedness is in the comparison operands. */ |
56099f00 | 1307 | uns = TYPE_UNSIGNED (r1type); |
0425d6f5 | 1308 | |
0b4b14ac RG |
1309 | /* If we know the most significant bits we know the values |
1310 | value ranges by means of treating varying bits as zero | |
1311 | or one. Do a cross comparison of the max/min pairs. */ | |
1312 | maxmin = double_int_cmp (double_int_ior (r1val, r1mask), | |
1313 | double_int_and_not (r2val, r2mask), uns); | |
1314 | minmax = double_int_cmp (double_int_and_not (r1val, r1mask), | |
1315 | double_int_ior (r2val, r2mask), uns); | |
1316 | if (maxmin < 0) /* r1 is less than r2. */ | |
1317 | { | |
1318 | *mask = double_int_zero; | |
1319 | *val = double_int_one; | |
1320 | } | |
1321 | else if (minmax > 0) /* r1 is not less or equal to r2. */ | |
1322 | { | |
1323 | *mask = double_int_zero; | |
1324 | *val = double_int_zero; | |
1325 | } | |
1326 | else if (maxmin == minmax) /* r1 and r2 are equal. */ | |
1327 | { | |
1328 | /* This probably should never happen as we'd have | |
1329 | folded the thing during fully constant value folding. */ | |
1330 | *mask = double_int_zero; | |
1331 | *val = (code == LE_EXPR ? double_int_one : double_int_zero); | |
1332 | } | |
1333 | else | |
1334 | { | |
1335 | /* We know the result of a comparison is always one or zero. */ | |
1336 | *mask = double_int_one; | |
1337 | *val = double_int_zero; | |
1338 | } | |
1339 | break; | |
1340 | } | |
1341 | ||
1342 | default:; | |
1343 | } | |
1344 | } | |
1345 | ||
1346 | /* Return the propagation value when applying the operation CODE to | |
1347 | the value RHS yielding type TYPE. */ | |
1348 | ||
1349 | static prop_value_t | |
1350 | bit_value_unop (enum tree_code code, tree type, tree rhs) | |
1351 | { | |
1352 | prop_value_t rval = get_value_for_expr (rhs, true); | |
1353 | double_int value, mask; | |
1354 | prop_value_t val; | |
6ad024b4 RG |
1355 | |
1356 | if (rval.lattice_val == UNDEFINED) | |
1357 | return rval; | |
1358 | ||
0b4b14ac RG |
1359 | gcc_assert ((rval.lattice_val == CONSTANT |
1360 | && TREE_CODE (rval.value) == INTEGER_CST) | |
1361 | || double_int_minus_one_p (rval.mask)); | |
1362 | bit_value_unop_1 (code, type, &value, &mask, | |
1363 | TREE_TYPE (rhs), value_to_double_int (rval), rval.mask); | |
1364 | if (!double_int_minus_one_p (mask)) | |
1365 | { | |
1366 | val.lattice_val = CONSTANT; | |
1367 | val.mask = mask; | |
1368 | /* ??? Delay building trees here. */ | |
1369 | val.value = double_int_to_tree (type, value); | |
1370 | } | |
1371 | else | |
1372 | { | |
1373 | val.lattice_val = VARYING; | |
1374 | val.value = NULL_TREE; | |
1375 | val.mask = double_int_minus_one; | |
1376 | } | |
1377 | return val; | |
1378 | } | |
1379 | ||
1380 | /* Return the propagation value when applying the operation CODE to | |
1381 | the values RHS1 and RHS2 yielding type TYPE. */ | |
1382 | ||
1383 | static prop_value_t | |
1384 | bit_value_binop (enum tree_code code, tree type, tree rhs1, tree rhs2) | |
1385 | { | |
1386 | prop_value_t r1val = get_value_for_expr (rhs1, true); | |
1387 | prop_value_t r2val = get_value_for_expr (rhs2, true); | |
1388 | double_int value, mask; | |
1389 | prop_value_t val; | |
6ad024b4 RG |
1390 | |
1391 | if (r1val.lattice_val == UNDEFINED | |
1392 | || r2val.lattice_val == UNDEFINED) | |
1393 | { | |
1394 | val.lattice_val = VARYING; | |
1395 | val.value = NULL_TREE; | |
1396 | val.mask = double_int_minus_one; | |
1397 | return val; | |
1398 | } | |
1399 | ||
0b4b14ac RG |
1400 | gcc_assert ((r1val.lattice_val == CONSTANT |
1401 | && TREE_CODE (r1val.value) == INTEGER_CST) | |
1402 | || double_int_minus_one_p (r1val.mask)); | |
1403 | gcc_assert ((r2val.lattice_val == CONSTANT | |
1404 | && TREE_CODE (r2val.value) == INTEGER_CST) | |
1405 | || double_int_minus_one_p (r2val.mask)); | |
1406 | bit_value_binop_1 (code, type, &value, &mask, | |
1407 | TREE_TYPE (rhs1), value_to_double_int (r1val), r1val.mask, | |
1408 | TREE_TYPE (rhs2), value_to_double_int (r2val), r2val.mask); | |
1409 | if (!double_int_minus_one_p (mask)) | |
1410 | { | |
1411 | val.lattice_val = CONSTANT; | |
1412 | val.mask = mask; | |
1413 | /* ??? Delay building trees here. */ | |
1414 | val.value = double_int_to_tree (type, value); | |
1415 | } | |
1416 | else | |
1417 | { | |
1418 | val.lattice_val = VARYING; | |
1419 | val.value = NULL_TREE; | |
1420 | val.mask = double_int_minus_one; | |
1421 | } | |
1422 | return val; | |
1423 | } | |
1424 | ||
45d439ac JJ |
1425 | /* Return the propagation value when applying __builtin_assume_aligned to |
1426 | its arguments. */ | |
1427 | ||
1428 | static prop_value_t | |
1429 | bit_value_assume_aligned (gimple stmt) | |
1430 | { | |
1431 | tree ptr = gimple_call_arg (stmt, 0), align, misalign = NULL_TREE; | |
1432 | tree type = TREE_TYPE (ptr); | |
1433 | unsigned HOST_WIDE_INT aligni, misaligni = 0; | |
1434 | prop_value_t ptrval = get_value_for_expr (ptr, true); | |
1435 | prop_value_t alignval; | |
1436 | double_int value, mask; | |
1437 | prop_value_t val; | |
1438 | if (ptrval.lattice_val == UNDEFINED) | |
1439 | return ptrval; | |
1440 | gcc_assert ((ptrval.lattice_val == CONSTANT | |
1441 | && TREE_CODE (ptrval.value) == INTEGER_CST) | |
1442 | || double_int_minus_one_p (ptrval.mask)); | |
1443 | align = gimple_call_arg (stmt, 1); | |
1444 | if (!host_integerp (align, 1)) | |
1445 | return ptrval; | |
1446 | aligni = tree_low_cst (align, 1); | |
1447 | if (aligni <= 1 | |
1448 | || (aligni & (aligni - 1)) != 0) | |
1449 | return ptrval; | |
1450 | if (gimple_call_num_args (stmt) > 2) | |
1451 | { | |
1452 | misalign = gimple_call_arg (stmt, 2); | |
1453 | if (!host_integerp (misalign, 1)) | |
1454 | return ptrval; | |
1455 | misaligni = tree_low_cst (misalign, 1); | |
1456 | if (misaligni >= aligni) | |
1457 | return ptrval; | |
1458 | } | |
1459 | align = build_int_cst_type (type, -aligni); | |
1460 | alignval = get_value_for_expr (align, true); | |
1461 | bit_value_binop_1 (BIT_AND_EXPR, type, &value, &mask, | |
1462 | type, value_to_double_int (ptrval), ptrval.mask, | |
1463 | type, value_to_double_int (alignval), alignval.mask); | |
1464 | if (!double_int_minus_one_p (mask)) | |
1465 | { | |
1466 | val.lattice_val = CONSTANT; | |
1467 | val.mask = mask; | |
1468 | gcc_assert ((mask.low & (aligni - 1)) == 0); | |
1469 | gcc_assert ((value.low & (aligni - 1)) == 0); | |
1470 | value.low |= misaligni; | |
1471 | /* ??? Delay building trees here. */ | |
1472 | val.value = double_int_to_tree (type, value); | |
1473 | } | |
1474 | else | |
1475 | { | |
1476 | val.lattice_val = VARYING; | |
1477 | val.value = NULL_TREE; | |
1478 | val.mask = double_int_minus_one; | |
1479 | } | |
1480 | return val; | |
1481 | } | |
1482 | ||
726a989a RB |
1483 | /* Evaluate statement STMT. |
1484 | Valid only for assignments, calls, conditionals, and switches. */ | |
6de9cd9a | 1485 | |
0bca51f0 | 1486 | static prop_value_t |
726a989a | 1487 | evaluate_stmt (gimple stmt) |
6de9cd9a | 1488 | { |
0bca51f0 | 1489 | prop_value_t val; |
faaf1436 | 1490 | tree simplified = NULL_TREE; |
0bca51f0 | 1491 | ccp_lattice_t likelyvalue = likely_value (stmt); |
0b4b14ac | 1492 | bool is_constant = false; |
13e49da9 | 1493 | unsigned int align; |
0bca51f0 | 1494 | |
0b4b14ac RG |
1495 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1496 | { | |
1497 | fprintf (dump_file, "which is likely "); | |
1498 | switch (likelyvalue) | |
1499 | { | |
1500 | case CONSTANT: | |
1501 | fprintf (dump_file, "CONSTANT"); | |
1502 | break; | |
1503 | case UNDEFINED: | |
1504 | fprintf (dump_file, "UNDEFINED"); | |
1505 | break; | |
1506 | case VARYING: | |
1507 | fprintf (dump_file, "VARYING"); | |
1508 | break; | |
1509 | default:; | |
1510 | } | |
1511 | fprintf (dump_file, "\n"); | |
1512 | } | |
6ac01510 | 1513 | |
6de9cd9a DN |
1514 | /* If the statement is likely to have a CONSTANT result, then try |
1515 | to fold the statement to determine the constant value. */ | |
726a989a RB |
1516 | /* FIXME. This is the only place that we call ccp_fold. |
1517 | Since likely_value never returns CONSTANT for calls, we will | |
1518 | not attempt to fold them, including builtins that may profit. */ | |
6de9cd9a | 1519 | if (likelyvalue == CONSTANT) |
0b4b14ac RG |
1520 | { |
1521 | fold_defer_overflow_warnings (); | |
1522 | simplified = ccp_fold (stmt); | |
1523 | is_constant = simplified && is_gimple_min_invariant (simplified); | |
1524 | fold_undefer_overflow_warnings (is_constant, stmt, 0); | |
1525 | if (is_constant) | |
1526 | { | |
1527 | /* The statement produced a constant value. */ | |
1528 | val.lattice_val = CONSTANT; | |
1529 | val.value = simplified; | |
1530 | val.mask = double_int_zero; | |
1531 | } | |
1532 | } | |
6de9cd9a DN |
1533 | /* If the statement is likely to have a VARYING result, then do not |
1534 | bother folding the statement. */ | |
87e1e42b | 1535 | else if (likelyvalue == VARYING) |
726a989a | 1536 | { |
e0c68ce9 | 1537 | enum gimple_code code = gimple_code (stmt); |
726a989a RB |
1538 | if (code == GIMPLE_ASSIGN) |
1539 | { | |
1540 | enum tree_code subcode = gimple_assign_rhs_code (stmt); | |
b8698a0f | 1541 | |
726a989a RB |
1542 | /* Other cases cannot satisfy is_gimple_min_invariant |
1543 | without folding. */ | |
1544 | if (get_gimple_rhs_class (subcode) == GIMPLE_SINGLE_RHS) | |
1545 | simplified = gimple_assign_rhs1 (stmt); | |
1546 | } | |
1547 | else if (code == GIMPLE_SWITCH) | |
1548 | simplified = gimple_switch_index (stmt); | |
1549 | else | |
44e10129 MM |
1550 | /* These cannot satisfy is_gimple_min_invariant without folding. */ |
1551 | gcc_assert (code == GIMPLE_CALL || code == GIMPLE_COND); | |
0b4b14ac RG |
1552 | is_constant = simplified && is_gimple_min_invariant (simplified); |
1553 | if (is_constant) | |
1554 | { | |
1555 | /* The statement produced a constant value. */ | |
1556 | val.lattice_val = CONSTANT; | |
1557 | val.value = simplified; | |
1558 | val.mask = double_int_zero; | |
1559 | } | |
726a989a | 1560 | } |
6de9cd9a | 1561 | |
0b4b14ac RG |
1562 | /* Resort to simplification for bitwise tracking. */ |
1563 | if (flag_tree_bit_ccp | |
36dc1a88 | 1564 | && (likelyvalue == CONSTANT || is_gimple_call (stmt)) |
0b4b14ac | 1565 | && !is_constant) |
00d382a8 | 1566 | { |
0b4b14ac | 1567 | enum gimple_code code = gimple_code (stmt); |
1be38ccb | 1568 | tree fndecl; |
0b4b14ac RG |
1569 | val.lattice_val = VARYING; |
1570 | val.value = NULL_TREE; | |
1571 | val.mask = double_int_minus_one; | |
1572 | if (code == GIMPLE_ASSIGN) | |
00d382a8 | 1573 | { |
0b4b14ac RG |
1574 | enum tree_code subcode = gimple_assign_rhs_code (stmt); |
1575 | tree rhs1 = gimple_assign_rhs1 (stmt); | |
1576 | switch (get_gimple_rhs_class (subcode)) | |
1577 | { | |
1578 | case GIMPLE_SINGLE_RHS: | |
1579 | if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
1580 | || POINTER_TYPE_P (TREE_TYPE (rhs1))) | |
1581 | val = get_value_for_expr (rhs1, true); | |
1582 | break; | |
1583 | ||
1584 | case GIMPLE_UNARY_RHS: | |
1585 | if ((INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
1586 | || POINTER_TYPE_P (TREE_TYPE (rhs1))) | |
1587 | && (INTEGRAL_TYPE_P (gimple_expr_type (stmt)) | |
1588 | || POINTER_TYPE_P (gimple_expr_type (stmt)))) | |
1589 | val = bit_value_unop (subcode, gimple_expr_type (stmt), rhs1); | |
1590 | break; | |
1591 | ||
1592 | case GIMPLE_BINARY_RHS: | |
1593 | if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
1594 | || POINTER_TYPE_P (TREE_TYPE (rhs1))) | |
1595 | { | |
4e996296 | 1596 | tree lhs = gimple_assign_lhs (stmt); |
0b4b14ac RG |
1597 | tree rhs2 = gimple_assign_rhs2 (stmt); |
1598 | val = bit_value_binop (subcode, | |
4e996296 | 1599 | TREE_TYPE (lhs), rhs1, rhs2); |
0b4b14ac RG |
1600 | } |
1601 | break; | |
1602 | ||
1603 | default:; | |
1604 | } | |
00d382a8 | 1605 | } |
0b4b14ac RG |
1606 | else if (code == GIMPLE_COND) |
1607 | { | |
1608 | enum tree_code code = gimple_cond_code (stmt); | |
1609 | tree rhs1 = gimple_cond_lhs (stmt); | |
1610 | tree rhs2 = gimple_cond_rhs (stmt); | |
1611 | if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
1612 | || POINTER_TYPE_P (TREE_TYPE (rhs1))) | |
1613 | val = bit_value_binop (code, TREE_TYPE (rhs1), rhs1, rhs2); | |
1614 | } | |
1be38ccb RG |
1615 | else if (code == GIMPLE_CALL |
1616 | && (fndecl = gimple_call_fndecl (stmt)) | |
1617 | && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL) | |
1618 | { | |
1619 | switch (DECL_FUNCTION_CODE (fndecl)) | |
1620 | { | |
1621 | case BUILT_IN_MALLOC: | |
1622 | case BUILT_IN_REALLOC: | |
1623 | case BUILT_IN_CALLOC: | |
36dc1a88 JJ |
1624 | case BUILT_IN_STRDUP: |
1625 | case BUILT_IN_STRNDUP: | |
1be38ccb RG |
1626 | val.lattice_val = CONSTANT; |
1627 | val.value = build_int_cst (TREE_TYPE (gimple_get_lhs (stmt)), 0); | |
1628 | val.mask = shwi_to_double_int | |
1629 | (~(((HOST_WIDE_INT) MALLOC_ABI_ALIGNMENT) | |
1630 | / BITS_PER_UNIT - 1)); | |
1631 | break; | |
1632 | ||
1633 | case BUILT_IN_ALLOCA: | |
13e49da9 TV |
1634 | case BUILT_IN_ALLOCA_WITH_ALIGN: |
1635 | align = (DECL_FUNCTION_CODE (fndecl) == BUILT_IN_ALLOCA_WITH_ALIGN | |
1636 | ? TREE_INT_CST_LOW (gimple_call_arg (stmt, 1)) | |
1637 | : BIGGEST_ALIGNMENT); | |
1be38ccb RG |
1638 | val.lattice_val = CONSTANT; |
1639 | val.value = build_int_cst (TREE_TYPE (gimple_get_lhs (stmt)), 0); | |
1640 | val.mask = shwi_to_double_int | |
13e49da9 | 1641 | (~(((HOST_WIDE_INT) align) |
1be38ccb RG |
1642 | / BITS_PER_UNIT - 1)); |
1643 | break; | |
1644 | ||
36dc1a88 JJ |
1645 | /* These builtins return their first argument, unmodified. */ |
1646 | case BUILT_IN_MEMCPY: | |
1647 | case BUILT_IN_MEMMOVE: | |
1648 | case BUILT_IN_MEMSET: | |
1649 | case BUILT_IN_STRCPY: | |
1650 | case BUILT_IN_STRNCPY: | |
1651 | case BUILT_IN_MEMCPY_CHK: | |
1652 | case BUILT_IN_MEMMOVE_CHK: | |
1653 | case BUILT_IN_MEMSET_CHK: | |
1654 | case BUILT_IN_STRCPY_CHK: | |
1655 | case BUILT_IN_STRNCPY_CHK: | |
1656 | val = get_value_for_expr (gimple_call_arg (stmt, 0), true); | |
1657 | break; | |
1658 | ||
45d439ac JJ |
1659 | case BUILT_IN_ASSUME_ALIGNED: |
1660 | val = bit_value_assume_aligned (stmt); | |
1661 | break; | |
1662 | ||
1be38ccb RG |
1663 | default:; |
1664 | } | |
1665 | } | |
0b4b14ac | 1666 | is_constant = (val.lattice_val == CONSTANT); |
00d382a8 RG |
1667 | } |
1668 | ||
0b4b14ac | 1669 | if (!is_constant) |
6de9cd9a DN |
1670 | { |
1671 | /* The statement produced a nonconstant value. If the statement | |
0bca51f0 DN |
1672 | had UNDEFINED operands, then the result of the statement |
1673 | should be UNDEFINED. Otherwise, the statement is VARYING. */ | |
106dec71 | 1674 | if (likelyvalue == UNDEFINED) |
0b4b14ac RG |
1675 | { |
1676 | val.lattice_val = likelyvalue; | |
1677 | val.mask = double_int_zero; | |
1678 | } | |
a318e3ac | 1679 | else |
0b4b14ac RG |
1680 | { |
1681 | val.lattice_val = VARYING; | |
1682 | val.mask = double_int_minus_one; | |
1683 | } | |
a318e3ac | 1684 | |
0bca51f0 | 1685 | val.value = NULL_TREE; |
6de9cd9a | 1686 | } |
750628d8 DN |
1687 | |
1688 | return val; | |
6de9cd9a DN |
1689 | } |
1690 | ||
0823efed DN |
1691 | typedef hash_table <gimple_statement_d, typed_pointer_hash<gimple_statement_d>, |
1692 | typed_pointer_equal<gimple_statement_d>, | |
1693 | typed_null_remove<gimple_statement_d> > | |
1694 | gimple_htab; | |
1695 | ||
2f31f742 TV |
1696 | /* Given a BUILT_IN_STACK_SAVE value SAVED_VAL, insert a clobber of VAR before |
1697 | each matching BUILT_IN_STACK_RESTORE. Mark visited phis in VISITED. */ | |
1698 | ||
1699 | static void | |
0823efed DN |
1700 | insert_clobber_before_stack_restore (tree saved_val, tree var, |
1701 | gimple_htab *visited) | |
2f31f742 TV |
1702 | { |
1703 | gimple stmt, clobber_stmt; | |
1704 | tree clobber; | |
1705 | imm_use_iterator iter; | |
1706 | gimple_stmt_iterator i; | |
1707 | gimple *slot; | |
1708 | ||
1709 | FOR_EACH_IMM_USE_STMT (stmt, iter, saved_val) | |
1710 | if (gimple_call_builtin_p (stmt, BUILT_IN_STACK_RESTORE)) | |
1711 | { | |
1712 | clobber = build_constructor (TREE_TYPE (var), NULL); | |
1713 | TREE_THIS_VOLATILE (clobber) = 1; | |
1714 | clobber_stmt = gimple_build_assign (var, clobber); | |
1715 | ||
1716 | i = gsi_for_stmt (stmt); | |
1717 | gsi_insert_before (&i, clobber_stmt, GSI_SAME_STMT); | |
1718 | } | |
1719 | else if (gimple_code (stmt) == GIMPLE_PHI) | |
1720 | { | |
0823efed DN |
1721 | if (!visited->is_created ()) |
1722 | visited->create (10); | |
2f31f742 | 1723 | |
0823efed | 1724 | slot = visited->find_slot (stmt, INSERT); |
2f31f742 TV |
1725 | if (*slot != NULL) |
1726 | continue; | |
1727 | ||
1728 | *slot = stmt; | |
1729 | insert_clobber_before_stack_restore (gimple_phi_result (stmt), var, | |
1730 | visited); | |
1731 | } | |
1732 | else | |
1733 | gcc_assert (is_gimple_debug (stmt)); | |
1734 | } | |
1735 | ||
1736 | /* Advance the iterator to the previous non-debug gimple statement in the same | |
1737 | or dominating basic block. */ | |
1738 | ||
1739 | static inline void | |
1740 | gsi_prev_dom_bb_nondebug (gimple_stmt_iterator *i) | |
1741 | { | |
1742 | basic_block dom; | |
1743 | ||
1744 | gsi_prev_nondebug (i); | |
1745 | while (gsi_end_p (*i)) | |
1746 | { | |
1747 | dom = get_immediate_dominator (CDI_DOMINATORS, i->bb); | |
1748 | if (dom == NULL || dom == ENTRY_BLOCK_PTR) | |
1749 | return; | |
1750 | ||
1751 | *i = gsi_last_bb (dom); | |
1752 | } | |
1753 | } | |
1754 | ||
1755 | /* Find a BUILT_IN_STACK_SAVE dominating gsi_stmt (I), and insert | |
b9bebd7f MJ |
1756 | a clobber of VAR before each matching BUILT_IN_STACK_RESTORE. |
1757 | ||
1758 | It is possible that BUILT_IN_STACK_SAVE cannot be find in a dominator when a | |
1759 | previous pass (such as DOM) duplicated it along multiple paths to a BB. In | |
1760 | that case the function gives up without inserting the clobbers. */ | |
2f31f742 TV |
1761 | |
1762 | static void | |
1763 | insert_clobbers_for_var (gimple_stmt_iterator i, tree var) | |
1764 | { | |
2f31f742 TV |
1765 | gimple stmt; |
1766 | tree saved_val; | |
0823efed | 1767 | gimple_htab visited; |
2f31f742 | 1768 | |
b9bebd7f | 1769 | for (; !gsi_end_p (i); gsi_prev_dom_bb_nondebug (&i)) |
2f31f742 TV |
1770 | { |
1771 | stmt = gsi_stmt (i); | |
1772 | ||
1773 | if (!gimple_call_builtin_p (stmt, BUILT_IN_STACK_SAVE)) | |
1774 | continue; | |
2f31f742 TV |
1775 | |
1776 | saved_val = gimple_call_lhs (stmt); | |
1777 | if (saved_val == NULL_TREE) | |
1778 | continue; | |
1779 | ||
1780 | insert_clobber_before_stack_restore (saved_val, var, &visited); | |
1781 | break; | |
1782 | } | |
1783 | ||
0823efed DN |
1784 | if (visited.is_created ()) |
1785 | visited.dispose (); | |
2f31f742 TV |
1786 | } |
1787 | ||
13e49da9 TV |
1788 | /* Detects a __builtin_alloca_with_align with constant size argument. Declares |
1789 | fixed-size array and returns the address, if found, otherwise returns | |
1790 | NULL_TREE. */ | |
1fed1006 TV |
1791 | |
1792 | static tree | |
13e49da9 | 1793 | fold_builtin_alloca_with_align (gimple stmt) |
1fed1006 TV |
1794 | { |
1795 | unsigned HOST_WIDE_INT size, threshold, n_elem; | |
1796 | tree lhs, arg, block, var, elem_type, array_type; | |
1fed1006 TV |
1797 | |
1798 | /* Get lhs. */ | |
1799 | lhs = gimple_call_lhs (stmt); | |
1800 | if (lhs == NULL_TREE) | |
1801 | return NULL_TREE; | |
1802 | ||
1803 | /* Detect constant argument. */ | |
1804 | arg = get_constant_value (gimple_call_arg (stmt, 0)); | |
5d882cc1 RG |
1805 | if (arg == NULL_TREE |
1806 | || TREE_CODE (arg) != INTEGER_CST | |
1fed1006 TV |
1807 | || !host_integerp (arg, 1)) |
1808 | return NULL_TREE; | |
5d882cc1 | 1809 | |
1fed1006 TV |
1810 | size = TREE_INT_CST_LOW (arg); |
1811 | ||
13e49da9 | 1812 | /* Heuristic: don't fold large allocas. */ |
1fed1006 | 1813 | threshold = (unsigned HOST_WIDE_INT)PARAM_VALUE (PARAM_LARGE_STACK_FRAME); |
13e49da9 TV |
1814 | /* In case the alloca is located at function entry, it has the same lifetime |
1815 | as a declared array, so we allow a larger size. */ | |
1fed1006 TV |
1816 | block = gimple_block (stmt); |
1817 | if (!(cfun->after_inlining | |
1818 | && TREE_CODE (BLOCK_SUPERCONTEXT (block)) == FUNCTION_DECL)) | |
1819 | threshold /= 10; | |
1820 | if (size > threshold) | |
1821 | return NULL_TREE; | |
1822 | ||
1823 | /* Declare array. */ | |
1824 | elem_type = build_nonstandard_integer_type (BITS_PER_UNIT, 1); | |
1825 | n_elem = size * 8 / BITS_PER_UNIT; | |
1fed1006 TV |
1826 | array_type = build_array_type_nelts (elem_type, n_elem); |
1827 | var = create_tmp_var (array_type, NULL); | |
13e49da9 | 1828 | DECL_ALIGN (var) = TREE_INT_CST_LOW (gimple_call_arg (stmt, 1)); |
703ffc30 TV |
1829 | { |
1830 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (lhs); | |
1831 | if (pi != NULL && !pi->pt.anything) | |
1832 | { | |
1833 | bool singleton_p; | |
1834 | unsigned uid; | |
1835 | singleton_p = pt_solution_singleton_p (&pi->pt, &uid); | |
1836 | gcc_assert (singleton_p); | |
1837 | SET_DECL_PT_UID (var, uid); | |
1838 | } | |
1839 | } | |
1fed1006 TV |
1840 | |
1841 | /* Fold alloca to the address of the array. */ | |
1842 | return fold_convert (TREE_TYPE (lhs), build_fold_addr_expr (var)); | |
1843 | } | |
1844 | ||
f61e18ec RG |
1845 | /* Fold the stmt at *GSI with CCP specific information that propagating |
1846 | and regular folding does not catch. */ | |
1847 | ||
1848 | static bool | |
1849 | ccp_fold_stmt (gimple_stmt_iterator *gsi) | |
1850 | { | |
1851 | gimple stmt = gsi_stmt (*gsi); | |
f61e18ec | 1852 | |
830bc550 RG |
1853 | switch (gimple_code (stmt)) |
1854 | { | |
1855 | case GIMPLE_COND: | |
1856 | { | |
1857 | prop_value_t val; | |
1858 | /* Statement evaluation will handle type mismatches in constants | |
1859 | more gracefully than the final propagation. This allows us to | |
1860 | fold more conditionals here. */ | |
1861 | val = evaluate_stmt (stmt); | |
1862 | if (val.lattice_val != CONSTANT | |
0b4b14ac | 1863 | || !double_int_zero_p (val.mask)) |
830bc550 RG |
1864 | return false; |
1865 | ||
0b4b14ac RG |
1866 | if (dump_file) |
1867 | { | |
1868 | fprintf (dump_file, "Folding predicate "); | |
1869 | print_gimple_expr (dump_file, stmt, 0, 0); | |
1870 | fprintf (dump_file, " to "); | |
1871 | print_generic_expr (dump_file, val.value, 0); | |
1872 | fprintf (dump_file, "\n"); | |
1873 | } | |
1874 | ||
830bc550 RG |
1875 | if (integer_zerop (val.value)) |
1876 | gimple_cond_make_false (stmt); | |
1877 | else | |
1878 | gimple_cond_make_true (stmt); | |
f61e18ec | 1879 | |
830bc550 RG |
1880 | return true; |
1881 | } | |
f61e18ec | 1882 | |
830bc550 RG |
1883 | case GIMPLE_CALL: |
1884 | { | |
1885 | tree lhs = gimple_call_lhs (stmt); | |
45a5b21a | 1886 | int flags = gimple_call_flags (stmt); |
84d77ca6 | 1887 | tree val; |
830bc550 RG |
1888 | tree argt; |
1889 | bool changed = false; | |
1890 | unsigned i; | |
1891 | ||
1892 | /* If the call was folded into a constant make sure it goes | |
1893 | away even if we cannot propagate into all uses because of | |
1894 | type issues. */ | |
1895 | if (lhs | |
1896 | && TREE_CODE (lhs) == SSA_NAME | |
45a5b21a JJ |
1897 | && (val = get_constant_value (lhs)) |
1898 | /* Don't optimize away calls that have side-effects. */ | |
1899 | && (flags & (ECF_CONST|ECF_PURE)) != 0 | |
1900 | && (flags & ECF_LOOPING_CONST_OR_PURE) == 0) | |
830bc550 | 1901 | { |
84d77ca6 | 1902 | tree new_rhs = unshare_expr (val); |
eb6b98c7 | 1903 | bool res; |
830bc550 RG |
1904 | if (!useless_type_conversion_p (TREE_TYPE (lhs), |
1905 | TREE_TYPE (new_rhs))) | |
1906 | new_rhs = fold_convert (TREE_TYPE (lhs), new_rhs); | |
eb6b98c7 RG |
1907 | res = update_call_from_tree (gsi, new_rhs); |
1908 | gcc_assert (res); | |
830bc550 RG |
1909 | return true; |
1910 | } | |
1911 | ||
25583c4f RS |
1912 | /* Internal calls provide no argument types, so the extra laxity |
1913 | for normal calls does not apply. */ | |
1914 | if (gimple_call_internal_p (stmt)) | |
1915 | return false; | |
1916 | ||
13e49da9 TV |
1917 | /* The heuristic of fold_builtin_alloca_with_align differs before and |
1918 | after inlining, so we don't require the arg to be changed into a | |
1919 | constant for folding, but just to be constant. */ | |
1920 | if (gimple_call_builtin_p (stmt, BUILT_IN_ALLOCA_WITH_ALIGN)) | |
1fed1006 | 1921 | { |
13e49da9 | 1922 | tree new_rhs = fold_builtin_alloca_with_align (stmt); |
5d882cc1 RG |
1923 | if (new_rhs) |
1924 | { | |
1925 | bool res = update_call_from_tree (gsi, new_rhs); | |
2f31f742 | 1926 | tree var = TREE_OPERAND (TREE_OPERAND (new_rhs, 0),0); |
5d882cc1 | 1927 | gcc_assert (res); |
2f31f742 | 1928 | insert_clobbers_for_var (*gsi, var); |
5d882cc1 RG |
1929 | return true; |
1930 | } | |
1fed1006 TV |
1931 | } |
1932 | ||
830bc550 RG |
1933 | /* Propagate into the call arguments. Compared to replace_uses_in |
1934 | this can use the argument slot types for type verification | |
1935 | instead of the current argument type. We also can safely | |
1936 | drop qualifiers here as we are dealing with constants anyway. */ | |
9bfc434b | 1937 | argt = TYPE_ARG_TYPES (gimple_call_fntype (stmt)); |
830bc550 RG |
1938 | for (i = 0; i < gimple_call_num_args (stmt) && argt; |
1939 | ++i, argt = TREE_CHAIN (argt)) | |
1940 | { | |
1941 | tree arg = gimple_call_arg (stmt, i); | |
1942 | if (TREE_CODE (arg) == SSA_NAME | |
84d77ca6 | 1943 | && (val = get_constant_value (arg)) |
830bc550 RG |
1944 | && useless_type_conversion_p |
1945 | (TYPE_MAIN_VARIANT (TREE_VALUE (argt)), | |
84d77ca6 | 1946 | TYPE_MAIN_VARIANT (TREE_TYPE (val)))) |
830bc550 | 1947 | { |
84d77ca6 | 1948 | gimple_call_set_arg (stmt, i, unshare_expr (val)); |
830bc550 RG |
1949 | changed = true; |
1950 | } | |
1951 | } | |
74e80a24 | 1952 | |
830bc550 RG |
1953 | return changed; |
1954 | } | |
f61e18ec | 1955 | |
5c95f07b RG |
1956 | case GIMPLE_ASSIGN: |
1957 | { | |
1958 | tree lhs = gimple_assign_lhs (stmt); | |
84d77ca6 | 1959 | tree val; |
5c95f07b RG |
1960 | |
1961 | /* If we have a load that turned out to be constant replace it | |
1962 | as we cannot propagate into all uses in all cases. */ | |
1963 | if (gimple_assign_single_p (stmt) | |
1964 | && TREE_CODE (lhs) == SSA_NAME | |
84d77ca6 | 1965 | && (val = get_constant_value (lhs))) |
5c95f07b | 1966 | { |
84d77ca6 | 1967 | tree rhs = unshare_expr (val); |
5c95f07b | 1968 | if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs))) |
70f34814 | 1969 | rhs = fold_build1 (VIEW_CONVERT_EXPR, TREE_TYPE (lhs), rhs); |
5c95f07b RG |
1970 | gimple_assign_set_rhs_from_tree (gsi, rhs); |
1971 | return true; | |
1972 | } | |
1973 | ||
1974 | return false; | |
1975 | } | |
1976 | ||
830bc550 RG |
1977 | default: |
1978 | return false; | |
1979 | } | |
f61e18ec RG |
1980 | } |
1981 | ||
750628d8 | 1982 | /* Visit the assignment statement STMT. Set the value of its LHS to the |
0bca51f0 DN |
1983 | value computed by the RHS and store LHS in *OUTPUT_P. If STMT |
1984 | creates virtual definitions, set the value of each new name to that | |
726a989a RB |
1985 | of the RHS (if we can derive a constant out of the RHS). |
1986 | Value-returning call statements also perform an assignment, and | |
1987 | are handled here. */ | |
6de9cd9a | 1988 | |
750628d8 | 1989 | static enum ssa_prop_result |
726a989a | 1990 | visit_assignment (gimple stmt, tree *output_p) |
6de9cd9a | 1991 | { |
0bca51f0 | 1992 | prop_value_t val; |
0bca51f0 | 1993 | enum ssa_prop_result retval; |
6de9cd9a | 1994 | |
726a989a | 1995 | tree lhs = gimple_get_lhs (stmt); |
6de9cd9a | 1996 | |
726a989a RB |
1997 | gcc_assert (gimple_code (stmt) != GIMPLE_CALL |
1998 | || gimple_call_lhs (stmt) != NULL_TREE); | |
1999 | ||
84d77ca6 RG |
2000 | if (gimple_assign_single_p (stmt) |
2001 | && gimple_assign_rhs_code (stmt) == SSA_NAME) | |
2002 | /* For a simple copy operation, we copy the lattice values. */ | |
2003 | val = *get_value (gimple_assign_rhs1 (stmt)); | |
750628d8 | 2004 | else |
726a989a RB |
2005 | /* Evaluate the statement, which could be |
2006 | either a GIMPLE_ASSIGN or a GIMPLE_CALL. */ | |
87e1e42b | 2007 | val = evaluate_stmt (stmt); |
6de9cd9a | 2008 | |
0bca51f0 | 2009 | retval = SSA_PROP_NOT_INTERESTING; |
6de9cd9a | 2010 | |
750628d8 | 2011 | /* Set the lattice value of the statement's output. */ |
0bca51f0 | 2012 | if (TREE_CODE (lhs) == SSA_NAME) |
6de9cd9a | 2013 | { |
0bca51f0 DN |
2014 | /* If STMT is an assignment to an SSA_NAME, we only have one |
2015 | value to set. */ | |
2016 | if (set_lattice_value (lhs, val)) | |
2017 | { | |
2018 | *output_p = lhs; | |
2019 | if (val.lattice_val == VARYING) | |
2020 | retval = SSA_PROP_VARYING; | |
2021 | else | |
2022 | retval = SSA_PROP_INTERESTING; | |
2023 | } | |
6de9cd9a | 2024 | } |
0bca51f0 DN |
2025 | |
2026 | return retval; | |
6de9cd9a DN |
2027 | } |
2028 | ||
6de9cd9a | 2029 | |
750628d8 DN |
2030 | /* Visit the conditional statement STMT. Return SSA_PROP_INTERESTING |
2031 | if it can determine which edge will be taken. Otherwise, return | |
2032 | SSA_PROP_VARYING. */ | |
2033 | ||
2034 | static enum ssa_prop_result | |
726a989a | 2035 | visit_cond_stmt (gimple stmt, edge *taken_edge_p) |
6de9cd9a | 2036 | { |
0bca51f0 | 2037 | prop_value_t val; |
750628d8 DN |
2038 | basic_block block; |
2039 | ||
726a989a | 2040 | block = gimple_bb (stmt); |
750628d8 | 2041 | val = evaluate_stmt (stmt); |
0b4b14ac RG |
2042 | if (val.lattice_val != CONSTANT |
2043 | || !double_int_zero_p (val.mask)) | |
2044 | return SSA_PROP_VARYING; | |
750628d8 DN |
2045 | |
2046 | /* Find which edge out of the conditional block will be taken and add it | |
2047 | to the worklist. If no single edge can be determined statically, | |
2048 | return SSA_PROP_VARYING to feed all the outgoing edges to the | |
2049 | propagation engine. */ | |
0b4b14ac | 2050 | *taken_edge_p = find_taken_edge (block, val.value); |
750628d8 DN |
2051 | if (*taken_edge_p) |
2052 | return SSA_PROP_INTERESTING; | |
2053 | else | |
2054 | return SSA_PROP_VARYING; | |
6de9cd9a DN |
2055 | } |
2056 | ||
6de9cd9a | 2057 | |
750628d8 DN |
2058 | /* Evaluate statement STMT. If the statement produces an output value and |
2059 | its evaluation changes the lattice value of its output, return | |
2060 | SSA_PROP_INTERESTING and set *OUTPUT_P to the SSA_NAME holding the | |
2061 | output value. | |
b8698a0f | 2062 | |
750628d8 DN |
2063 | If STMT is a conditional branch and we can determine its truth |
2064 | value, set *TAKEN_EDGE_P accordingly. If STMT produces a varying | |
2065 | value, return SSA_PROP_VARYING. */ | |
6de9cd9a | 2066 | |
750628d8 | 2067 | static enum ssa_prop_result |
726a989a | 2068 | ccp_visit_stmt (gimple stmt, edge *taken_edge_p, tree *output_p) |
750628d8 | 2069 | { |
750628d8 DN |
2070 | tree def; |
2071 | ssa_op_iter iter; | |
6de9cd9a | 2072 | |
750628d8 | 2073 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6de9cd9a | 2074 | { |
0bca51f0 | 2075 | fprintf (dump_file, "\nVisiting statement:\n"); |
726a989a | 2076 | print_gimple_stmt (dump_file, stmt, 0, dump_flags); |
6de9cd9a | 2077 | } |
6de9cd9a | 2078 | |
726a989a | 2079 | switch (gimple_code (stmt)) |
6de9cd9a | 2080 | { |
726a989a RB |
2081 | case GIMPLE_ASSIGN: |
2082 | /* If the statement is an assignment that produces a single | |
2083 | output value, evaluate its RHS to see if the lattice value of | |
2084 | its output has changed. */ | |
2085 | return visit_assignment (stmt, output_p); | |
2086 | ||
2087 | case GIMPLE_CALL: | |
2088 | /* A value-returning call also performs an assignment. */ | |
2089 | if (gimple_call_lhs (stmt) != NULL_TREE) | |
2090 | return visit_assignment (stmt, output_p); | |
2091 | break; | |
2092 | ||
2093 | case GIMPLE_COND: | |
2094 | case GIMPLE_SWITCH: | |
2095 | /* If STMT is a conditional branch, see if we can determine | |
2096 | which branch will be taken. */ | |
2097 | /* FIXME. It appears that we should be able to optimize | |
2098 | computed GOTOs here as well. */ | |
2099 | return visit_cond_stmt (stmt, taken_edge_p); | |
2100 | ||
2101 | default: | |
2102 | break; | |
6de9cd9a | 2103 | } |
6de9cd9a | 2104 | |
750628d8 DN |
2105 | /* Any other kind of statement is not interesting for constant |
2106 | propagation and, therefore, not worth simulating. */ | |
750628d8 DN |
2107 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2108 | fprintf (dump_file, "No interesting values produced. Marked VARYING.\n"); | |
6de9cd9a | 2109 | |
750628d8 DN |
2110 | /* Definitions made by statements other than assignments to |
2111 | SSA_NAMEs represent unknown modifications to their outputs. | |
2112 | Mark them VARYING. */ | |
0bca51f0 DN |
2113 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS) |
2114 | { | |
0b4b14ac | 2115 | prop_value_t v = { VARYING, NULL_TREE, { -1, (HOST_WIDE_INT) -1 } }; |
0bca51f0 DN |
2116 | set_lattice_value (def, v); |
2117 | } | |
6de9cd9a | 2118 | |
750628d8 DN |
2119 | return SSA_PROP_VARYING; |
2120 | } | |
6de9cd9a | 2121 | |
6de9cd9a | 2122 | |
0bca51f0 | 2123 | /* Main entry point for SSA Conditional Constant Propagation. */ |
750628d8 | 2124 | |
3253eafb | 2125 | static unsigned int |
dce2b2f6 | 2126 | do_ssa_ccp (void) |
750628d8 | 2127 | { |
2f31f742 TV |
2128 | unsigned int todo = 0; |
2129 | calculate_dominance_info (CDI_DOMINATORS); | |
750628d8 DN |
2130 | ccp_initialize (); |
2131 | ssa_propagate (ccp_visit_stmt, ccp_visit_phi_node); | |
3253eafb | 2132 | if (ccp_finalize ()) |
2f31f742 TV |
2133 | todo = (TODO_cleanup_cfg | TODO_update_ssa | TODO_remove_unused_locals); |
2134 | free_dominance_info (CDI_DOMINATORS); | |
2135 | return todo; | |
6de9cd9a DN |
2136 | } |
2137 | ||
173b818d BB |
2138 | |
2139 | static bool | |
750628d8 | 2140 | gate_ccp (void) |
173b818d | 2141 | { |
750628d8 | 2142 | return flag_tree_ccp != 0; |
173b818d BB |
2143 | } |
2144 | ||
6de9cd9a | 2145 | |
b8698a0f | 2146 | struct gimple_opt_pass pass_ccp = |
750628d8 | 2147 | { |
8ddbbcae JH |
2148 | { |
2149 | GIMPLE_PASS, | |
750628d8 DN |
2150 | "ccp", /* name */ |
2151 | gate_ccp, /* gate */ | |
0bca51f0 | 2152 | do_ssa_ccp, /* execute */ |
750628d8 DN |
2153 | NULL, /* sub */ |
2154 | NULL, /* next */ | |
2155 | 0, /* static_pass_number */ | |
2156 | TV_TREE_CCP, /* tv_id */ | |
7faade0f | 2157 | PROP_cfg | PROP_ssa, /* properties_required */ |
750628d8 | 2158 | 0, /* properties_provided */ |
ae07b463 | 2159 | 0, /* properties_destroyed */ |
750628d8 | 2160 | 0, /* todo_flags_start */ |
22c5fa5f | 2161 | TODO_verify_ssa |
8ddbbcae JH |
2162 | | TODO_verify_stmts | TODO_ggc_collect/* todo_flags_finish */ |
2163 | } | |
750628d8 | 2164 | }; |
6de9cd9a | 2165 | |
6de9cd9a | 2166 | |
726a989a | 2167 | |
cb8e078d JJ |
2168 | /* Try to optimize out __builtin_stack_restore. Optimize it out |
2169 | if there is another __builtin_stack_restore in the same basic | |
2170 | block and no calls or ASM_EXPRs are in between, or if this block's | |
2171 | only outgoing edge is to EXIT_BLOCK and there are no calls or | |
2172 | ASM_EXPRs after this __builtin_stack_restore. */ | |
2173 | ||
2174 | static tree | |
726a989a | 2175 | optimize_stack_restore (gimple_stmt_iterator i) |
cb8e078d | 2176 | { |
ff9d1adc RH |
2177 | tree callee; |
2178 | gimple stmt; | |
726a989a RB |
2179 | |
2180 | basic_block bb = gsi_bb (i); | |
2181 | gimple call = gsi_stmt (i); | |
cb8e078d | 2182 | |
726a989a RB |
2183 | if (gimple_code (call) != GIMPLE_CALL |
2184 | || gimple_call_num_args (call) != 1 | |
2185 | || TREE_CODE (gimple_call_arg (call, 0)) != SSA_NAME | |
2186 | || !POINTER_TYPE_P (TREE_TYPE (gimple_call_arg (call, 0)))) | |
cb8e078d JJ |
2187 | return NULL_TREE; |
2188 | ||
726a989a | 2189 | for (gsi_next (&i); !gsi_end_p (i); gsi_next (&i)) |
cb8e078d | 2190 | { |
726a989a RB |
2191 | stmt = gsi_stmt (i); |
2192 | if (gimple_code (stmt) == GIMPLE_ASM) | |
cb8e078d | 2193 | return NULL_TREE; |
726a989a | 2194 | if (gimple_code (stmt) != GIMPLE_CALL) |
cb8e078d JJ |
2195 | continue; |
2196 | ||
726a989a | 2197 | callee = gimple_call_fndecl (stmt); |
12f9ddbc RG |
2198 | if (!callee |
2199 | || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL | |
2200 | /* All regular builtins are ok, just obviously not alloca. */ | |
13e49da9 TV |
2201 | || DECL_FUNCTION_CODE (callee) == BUILT_IN_ALLOCA |
2202 | || DECL_FUNCTION_CODE (callee) == BUILT_IN_ALLOCA_WITH_ALIGN) | |
cb8e078d JJ |
2203 | return NULL_TREE; |
2204 | ||
2205 | if (DECL_FUNCTION_CODE (callee) == BUILT_IN_STACK_RESTORE) | |
ff9d1adc | 2206 | goto second_stack_restore; |
cb8e078d JJ |
2207 | } |
2208 | ||
ff9d1adc | 2209 | if (!gsi_end_p (i)) |
cb8e078d JJ |
2210 | return NULL_TREE; |
2211 | ||
ff9d1adc RH |
2212 | /* Allow one successor of the exit block, or zero successors. */ |
2213 | switch (EDGE_COUNT (bb->succs)) | |
2214 | { | |
2215 | case 0: | |
2216 | break; | |
2217 | case 1: | |
2218 | if (single_succ_edge (bb)->dest != EXIT_BLOCK_PTR) | |
2219 | return NULL_TREE; | |
2220 | break; | |
2221 | default: | |
2222 | return NULL_TREE; | |
2223 | } | |
2224 | second_stack_restore: | |
cb8e078d | 2225 | |
ff9d1adc RH |
2226 | /* If there's exactly one use, then zap the call to __builtin_stack_save. |
2227 | If there are multiple uses, then the last one should remove the call. | |
2228 | In any case, whether the call to __builtin_stack_save can be removed | |
2229 | or not is irrelevant to removing the call to __builtin_stack_restore. */ | |
2230 | if (has_single_use (gimple_call_arg (call, 0))) | |
2231 | { | |
2232 | gimple stack_save = SSA_NAME_DEF_STMT (gimple_call_arg (call, 0)); | |
2233 | if (is_gimple_call (stack_save)) | |
2234 | { | |
2235 | callee = gimple_call_fndecl (stack_save); | |
2236 | if (callee | |
2237 | && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL | |
2238 | && DECL_FUNCTION_CODE (callee) == BUILT_IN_STACK_SAVE) | |
2239 | { | |
2240 | gimple_stmt_iterator stack_save_gsi; | |
2241 | tree rhs; | |
cb8e078d | 2242 | |
ff9d1adc RH |
2243 | stack_save_gsi = gsi_for_stmt (stack_save); |
2244 | rhs = build_int_cst (TREE_TYPE (gimple_call_arg (call, 0)), 0); | |
2245 | update_call_from_tree (&stack_save_gsi, rhs); | |
2246 | } | |
2247 | } | |
2248 | } | |
cb8e078d | 2249 | |
726a989a | 2250 | /* No effect, so the statement will be deleted. */ |
cb8e078d JJ |
2251 | return integer_zero_node; |
2252 | } | |
726a989a | 2253 | |
d7bd8aeb JJ |
2254 | /* If va_list type is a simple pointer and nothing special is needed, |
2255 | optimize __builtin_va_start (&ap, 0) into ap = __builtin_next_arg (0), | |
2256 | __builtin_va_end (&ap) out as NOP and __builtin_va_copy into a simple | |
2257 | pointer assignment. */ | |
2258 | ||
2259 | static tree | |
726a989a | 2260 | optimize_stdarg_builtin (gimple call) |
d7bd8aeb | 2261 | { |
35cbb299 | 2262 | tree callee, lhs, rhs, cfun_va_list; |
d7bd8aeb | 2263 | bool va_list_simple_ptr; |
db3927fb | 2264 | location_t loc = gimple_location (call); |
d7bd8aeb | 2265 | |
726a989a | 2266 | if (gimple_code (call) != GIMPLE_CALL) |
d7bd8aeb JJ |
2267 | return NULL_TREE; |
2268 | ||
726a989a | 2269 | callee = gimple_call_fndecl (call); |
35cbb299 KT |
2270 | |
2271 | cfun_va_list = targetm.fn_abi_va_list (callee); | |
2272 | va_list_simple_ptr = POINTER_TYPE_P (cfun_va_list) | |
2273 | && (TREE_TYPE (cfun_va_list) == void_type_node | |
2274 | || TREE_TYPE (cfun_va_list) == char_type_node); | |
2275 | ||
d7bd8aeb JJ |
2276 | switch (DECL_FUNCTION_CODE (callee)) |
2277 | { | |
2278 | case BUILT_IN_VA_START: | |
2279 | if (!va_list_simple_ptr | |
2280 | || targetm.expand_builtin_va_start != NULL | |
f25a65f5 | 2281 | || !builtin_decl_explicit_p (BUILT_IN_NEXT_ARG)) |
d7bd8aeb JJ |
2282 | return NULL_TREE; |
2283 | ||
726a989a | 2284 | if (gimple_call_num_args (call) != 2) |
d7bd8aeb JJ |
2285 | return NULL_TREE; |
2286 | ||
726a989a | 2287 | lhs = gimple_call_arg (call, 0); |
d7bd8aeb JJ |
2288 | if (!POINTER_TYPE_P (TREE_TYPE (lhs)) |
2289 | || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs))) | |
35cbb299 | 2290 | != TYPE_MAIN_VARIANT (cfun_va_list)) |
d7bd8aeb | 2291 | return NULL_TREE; |
b8698a0f | 2292 | |
db3927fb | 2293 | lhs = build_fold_indirect_ref_loc (loc, lhs); |
e79983f4 | 2294 | rhs = build_call_expr_loc (loc, builtin_decl_explicit (BUILT_IN_NEXT_ARG), |
726a989a | 2295 | 1, integer_zero_node); |
db3927fb | 2296 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); |
d7bd8aeb JJ |
2297 | return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs); |
2298 | ||
2299 | case BUILT_IN_VA_COPY: | |
2300 | if (!va_list_simple_ptr) | |
2301 | return NULL_TREE; | |
2302 | ||
726a989a | 2303 | if (gimple_call_num_args (call) != 2) |
d7bd8aeb JJ |
2304 | return NULL_TREE; |
2305 | ||
726a989a | 2306 | lhs = gimple_call_arg (call, 0); |
d7bd8aeb JJ |
2307 | if (!POINTER_TYPE_P (TREE_TYPE (lhs)) |
2308 | || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs))) | |
35cbb299 | 2309 | != TYPE_MAIN_VARIANT (cfun_va_list)) |
d7bd8aeb JJ |
2310 | return NULL_TREE; |
2311 | ||
db3927fb | 2312 | lhs = build_fold_indirect_ref_loc (loc, lhs); |
726a989a | 2313 | rhs = gimple_call_arg (call, 1); |
d7bd8aeb | 2314 | if (TYPE_MAIN_VARIANT (TREE_TYPE (rhs)) |
35cbb299 | 2315 | != TYPE_MAIN_VARIANT (cfun_va_list)) |
d7bd8aeb JJ |
2316 | return NULL_TREE; |
2317 | ||
db3927fb | 2318 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); |
d7bd8aeb JJ |
2319 | return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs); |
2320 | ||
2321 | case BUILT_IN_VA_END: | |
726a989a | 2322 | /* No effect, so the statement will be deleted. */ |
d7bd8aeb JJ |
2323 | return integer_zero_node; |
2324 | ||
2325 | default: | |
2326 | gcc_unreachable (); | |
2327 | } | |
2328 | } | |
726a989a | 2329 | |
c61e5cc1 TV |
2330 | /* Attemp to make the block of __builtin_unreachable I unreachable by changing |
2331 | the incoming jumps. Return true if at least one jump was changed. */ | |
2332 | ||
2333 | static bool | |
2334 | optimize_unreachable (gimple_stmt_iterator i) | |
2335 | { | |
2336 | basic_block bb = gsi_bb (i); | |
2337 | gimple_stmt_iterator gsi; | |
2338 | gimple stmt; | |
2339 | edge_iterator ei; | |
2340 | edge e; | |
2341 | bool ret; | |
2342 | ||
2343 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
2344 | { | |
2345 | stmt = gsi_stmt (gsi); | |
2346 | ||
2347 | if (is_gimple_debug (stmt)) | |
2348 | continue; | |
2349 | ||
2350 | if (gimple_code (stmt) == GIMPLE_LABEL) | |
2351 | { | |
2352 | /* Verify we do not need to preserve the label. */ | |
2353 | if (FORCED_LABEL (gimple_label_label (stmt))) | |
2354 | return false; | |
2355 | ||
2356 | continue; | |
2357 | } | |
2358 | ||
2359 | /* Only handle the case that __builtin_unreachable is the first statement | |
2360 | in the block. We rely on DCE to remove stmts without side-effects | |
2361 | before __builtin_unreachable. */ | |
2362 | if (gsi_stmt (gsi) != gsi_stmt (i)) | |
2363 | return false; | |
2364 | } | |
2365 | ||
2366 | ret = false; | |
2367 | FOR_EACH_EDGE (e, ei, bb->preds) | |
2368 | { | |
2369 | gsi = gsi_last_bb (e->src); | |
cd356d96 UW |
2370 | if (gsi_end_p (gsi)) |
2371 | continue; | |
c61e5cc1 | 2372 | |
cd356d96 UW |
2373 | stmt = gsi_stmt (gsi); |
2374 | if (gimple_code (stmt) == GIMPLE_COND) | |
c61e5cc1 TV |
2375 | { |
2376 | if (e->flags & EDGE_TRUE_VALUE) | |
2377 | gimple_cond_make_false (stmt); | |
2378 | else if (e->flags & EDGE_FALSE_VALUE) | |
2379 | gimple_cond_make_true (stmt); | |
2380 | else | |
2381 | gcc_unreachable (); | |
2382 | } | |
2383 | else | |
2384 | { | |
2385 | /* Todo: handle other cases, f.i. switch statement. */ | |
2386 | continue; | |
2387 | } | |
2388 | ||
2389 | ret = true; | |
2390 | } | |
2391 | ||
2392 | return ret; | |
2393 | } | |
2394 | ||
6de9cd9a DN |
2395 | /* A simple pass that attempts to fold all builtin functions. This pass |
2396 | is run after we've propagated as many constants as we can. */ | |
2397 | ||
c2924966 | 2398 | static unsigned int |
6de9cd9a DN |
2399 | execute_fold_all_builtins (void) |
2400 | { | |
a7d6ba24 | 2401 | bool cfg_changed = false; |
6de9cd9a | 2402 | basic_block bb; |
7b0e48fb | 2403 | unsigned int todoflags = 0; |
b8698a0f | 2404 | |
6de9cd9a DN |
2405 | FOR_EACH_BB (bb) |
2406 | { | |
726a989a RB |
2407 | gimple_stmt_iterator i; |
2408 | for (i = gsi_start_bb (bb); !gsi_end_p (i); ) | |
6de9cd9a | 2409 | { |
726a989a | 2410 | gimple stmt, old_stmt; |
6de9cd9a | 2411 | tree callee, result; |
10a0d495 | 2412 | enum built_in_function fcode; |
6de9cd9a | 2413 | |
726a989a RB |
2414 | stmt = gsi_stmt (i); |
2415 | ||
2416 | if (gimple_code (stmt) != GIMPLE_CALL) | |
10a0d495 | 2417 | { |
726a989a | 2418 | gsi_next (&i); |
10a0d495 JJ |
2419 | continue; |
2420 | } | |
726a989a | 2421 | callee = gimple_call_fndecl (stmt); |
6de9cd9a | 2422 | if (!callee || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL) |
10a0d495 | 2423 | { |
726a989a | 2424 | gsi_next (&i); |
10a0d495 JJ |
2425 | continue; |
2426 | } | |
2427 | fcode = DECL_FUNCTION_CODE (callee); | |
6de9cd9a | 2428 | |
cbdd87d4 | 2429 | result = gimple_fold_builtin (stmt); |
53a8f709 UB |
2430 | |
2431 | if (result) | |
726a989a | 2432 | gimple_remove_stmt_histograms (cfun, stmt); |
53a8f709 | 2433 | |
6de9cd9a DN |
2434 | if (!result) |
2435 | switch (DECL_FUNCTION_CODE (callee)) | |
2436 | { | |
2437 | case BUILT_IN_CONSTANT_P: | |
2438 | /* Resolve __builtin_constant_p. If it hasn't been | |
2439 | folded to integer_one_node by now, it's fairly | |
2440 | certain that the value simply isn't constant. */ | |
726a989a | 2441 | result = integer_zero_node; |
6de9cd9a DN |
2442 | break; |
2443 | ||
45d439ac JJ |
2444 | case BUILT_IN_ASSUME_ALIGNED: |
2445 | /* Remove __builtin_assume_aligned. */ | |
2446 | result = gimple_call_arg (stmt, 0); | |
2447 | break; | |
2448 | ||
cb8e078d | 2449 | case BUILT_IN_STACK_RESTORE: |
726a989a | 2450 | result = optimize_stack_restore (i); |
d7bd8aeb JJ |
2451 | if (result) |
2452 | break; | |
726a989a | 2453 | gsi_next (&i); |
d7bd8aeb JJ |
2454 | continue; |
2455 | ||
c61e5cc1 TV |
2456 | case BUILT_IN_UNREACHABLE: |
2457 | if (optimize_unreachable (i)) | |
2458 | cfg_changed = true; | |
2459 | break; | |
2460 | ||
d7bd8aeb JJ |
2461 | case BUILT_IN_VA_START: |
2462 | case BUILT_IN_VA_END: | |
2463 | case BUILT_IN_VA_COPY: | |
2464 | /* These shouldn't be folded before pass_stdarg. */ | |
726a989a | 2465 | result = optimize_stdarg_builtin (stmt); |
cb8e078d JJ |
2466 | if (result) |
2467 | break; | |
2468 | /* FALLTHRU */ | |
2469 | ||
6de9cd9a | 2470 | default: |
726a989a | 2471 | gsi_next (&i); |
6de9cd9a DN |
2472 | continue; |
2473 | } | |
2474 | ||
c61e5cc1 TV |
2475 | if (result == NULL_TREE) |
2476 | break; | |
2477 | ||
6de9cd9a DN |
2478 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2479 | { | |
2480 | fprintf (dump_file, "Simplified\n "); | |
726a989a | 2481 | print_gimple_stmt (dump_file, stmt, 0, dump_flags); |
6de9cd9a DN |
2482 | } |
2483 | ||
726a989a | 2484 | old_stmt = stmt; |
726a989a | 2485 | if (!update_call_from_tree (&i, result)) |
4bad83f5 RG |
2486 | { |
2487 | gimplify_and_update_call_from_tree (&i, result); | |
2488 | todoflags |= TODO_update_address_taken; | |
2489 | } | |
cfaab3a9 | 2490 | |
726a989a | 2491 | stmt = gsi_stmt (i); |
cff4e50d | 2492 | update_stmt (stmt); |
cfaab3a9 | 2493 | |
726a989a RB |
2494 | if (maybe_clean_or_replace_eh_stmt (old_stmt, stmt) |
2495 | && gimple_purge_dead_eh_edges (bb)) | |
a7d6ba24 | 2496 | cfg_changed = true; |
6de9cd9a DN |
2497 | |
2498 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2499 | { | |
2500 | fprintf (dump_file, "to\n "); | |
726a989a | 2501 | print_gimple_stmt (dump_file, stmt, 0, dump_flags); |
6de9cd9a DN |
2502 | fprintf (dump_file, "\n"); |
2503 | } | |
10a0d495 JJ |
2504 | |
2505 | /* Retry the same statement if it changed into another | |
2506 | builtin, there might be new opportunities now. */ | |
726a989a | 2507 | if (gimple_code (stmt) != GIMPLE_CALL) |
10a0d495 | 2508 | { |
726a989a | 2509 | gsi_next (&i); |
10a0d495 JJ |
2510 | continue; |
2511 | } | |
726a989a | 2512 | callee = gimple_call_fndecl (stmt); |
10a0d495 | 2513 | if (!callee |
726a989a | 2514 | || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL |
10a0d495 | 2515 | || DECL_FUNCTION_CODE (callee) == fcode) |
726a989a | 2516 | gsi_next (&i); |
6de9cd9a DN |
2517 | } |
2518 | } | |
b8698a0f | 2519 | |
a7d6ba24 | 2520 | /* Delete unreachable blocks. */ |
7b0e48fb DB |
2521 | if (cfg_changed) |
2522 | todoflags |= TODO_cleanup_cfg; | |
b8698a0f | 2523 | |
7b0e48fb | 2524 | return todoflags; |
6de9cd9a DN |
2525 | } |
2526 | ||
750628d8 | 2527 | |
b8698a0f | 2528 | struct gimple_opt_pass pass_fold_builtins = |
6de9cd9a | 2529 | { |
8ddbbcae JH |
2530 | { |
2531 | GIMPLE_PASS, | |
6de9cd9a DN |
2532 | "fab", /* name */ |
2533 | NULL, /* gate */ | |
2534 | execute_fold_all_builtins, /* execute */ | |
2535 | NULL, /* sub */ | |
2536 | NULL, /* next */ | |
2537 | 0, /* static_pass_number */ | |
7072a650 | 2538 | TV_NONE, /* tv_id */ |
7faade0f | 2539 | PROP_cfg | PROP_ssa, /* properties_required */ |
6de9cd9a DN |
2540 | 0, /* properties_provided */ |
2541 | 0, /* properties_destroyed */ | |
2542 | 0, /* todo_flags_start */ | |
22c5fa5f | 2543 | TODO_verify_ssa |
8ddbbcae JH |
2544 | | TODO_update_ssa /* todo_flags_finish */ |
2545 | } | |
6de9cd9a | 2546 | }; |