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6de9cd9a | 1 | /* Conditional constant propagation pass for the GNU compiler. |
23a5b65a | 2 | Copyright (C) 2000-2014 Free Software Foundation, Inc. |
6de9cd9a DN |
3 | Adapted from original RTL SSA-CCP by Daniel Berlin <dberlin@dberlin.org> |
4 | Adapted to GIMPLE trees by Diego Novillo <dnovillo@redhat.com> | |
5 | ||
6 | This file is part of GCC. | |
b8698a0f | 7 | |
6de9cd9a DN |
8 | GCC is free software; you can redistribute it and/or modify it |
9 | under the terms of the GNU General Public License as published by the | |
9dcd6f09 | 10 | Free Software Foundation; either version 3, or (at your option) any |
6de9cd9a | 11 | later version. |
b8698a0f | 12 | |
6de9cd9a DN |
13 | GCC is distributed in the hope that it will be useful, but WITHOUT |
14 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
16 | for more details. | |
b8698a0f | 17 | |
6de9cd9a | 18 | You should have received a copy of the GNU General Public License |
9dcd6f09 NC |
19 | along with GCC; see the file COPYING3. If not see |
20 | <http://www.gnu.org/licenses/>. */ | |
6de9cd9a | 21 | |
0bca51f0 DN |
22 | /* Conditional constant propagation (CCP) is based on the SSA |
23 | propagation engine (tree-ssa-propagate.c). Constant assignments of | |
24 | the form VAR = CST are propagated from the assignments into uses of | |
25 | VAR, which in turn may generate new constants. The simulation uses | |
26 | a four level lattice to keep track of constant values associated | |
27 | with SSA names. Given an SSA name V_i, it may take one of the | |
28 | following values: | |
29 | ||
106dec71 ZD |
30 | UNINITIALIZED -> the initial state of the value. This value |
31 | is replaced with a correct initial value | |
32 | the first time the value is used, so the | |
33 | rest of the pass does not need to care about | |
34 | it. Using this value simplifies initialization | |
35 | of the pass, and prevents us from needlessly | |
36 | scanning statements that are never reached. | |
0bca51f0 DN |
37 | |
38 | UNDEFINED -> V_i is a local variable whose definition | |
39 | has not been processed yet. Therefore we | |
40 | don't yet know if its value is a constant | |
41 | or not. | |
42 | ||
43 | CONSTANT -> V_i has been found to hold a constant | |
44 | value C. | |
45 | ||
46 | VARYING -> V_i cannot take a constant value, or if it | |
47 | does, it is not possible to determine it | |
48 | at compile time. | |
49 | ||
50 | The core of SSA-CCP is in ccp_visit_stmt and ccp_visit_phi_node: | |
51 | ||
52 | 1- In ccp_visit_stmt, we are interested in assignments whose RHS | |
53 | evaluates into a constant and conditional jumps whose predicate | |
54 | evaluates into a boolean true or false. When an assignment of | |
55 | the form V_i = CONST is found, V_i's lattice value is set to | |
56 | CONSTANT and CONST is associated with it. This causes the | |
57 | propagation engine to add all the SSA edges coming out the | |
58 | assignment into the worklists, so that statements that use V_i | |
59 | can be visited. | |
60 | ||
61 | If the statement is a conditional with a constant predicate, we | |
62 | mark the outgoing edges as executable or not executable | |
63 | depending on the predicate's value. This is then used when | |
64 | visiting PHI nodes to know when a PHI argument can be ignored. | |
b8698a0f | 65 | |
0bca51f0 DN |
66 | |
67 | 2- In ccp_visit_phi_node, if all the PHI arguments evaluate to the | |
68 | same constant C, then the LHS of the PHI is set to C. This | |
69 | evaluation is known as the "meet operation". Since one of the | |
70 | goals of this evaluation is to optimistically return constant | |
71 | values as often as possible, it uses two main short cuts: | |
72 | ||
73 | - If an argument is flowing in through a non-executable edge, it | |
74 | is ignored. This is useful in cases like this: | |
75 | ||
76 | if (PRED) | |
77 | a_9 = 3; | |
78 | else | |
79 | a_10 = 100; | |
80 | a_11 = PHI (a_9, a_10) | |
81 | ||
82 | If PRED is known to always evaluate to false, then we can | |
83 | assume that a_11 will always take its value from a_10, meaning | |
84 | that instead of consider it VARYING (a_9 and a_10 have | |
85 | different values), we can consider it CONSTANT 100. | |
86 | ||
87 | - If an argument has an UNDEFINED value, then it does not affect | |
88 | the outcome of the meet operation. If a variable V_i has an | |
89 | UNDEFINED value, it means that either its defining statement | |
90 | hasn't been visited yet or V_i has no defining statement, in | |
91 | which case the original symbol 'V' is being used | |
92 | uninitialized. Since 'V' is a local variable, the compiler | |
93 | may assume any initial value for it. | |
94 | ||
95 | ||
96 | After propagation, every variable V_i that ends up with a lattice | |
97 | value of CONSTANT will have the associated constant value in the | |
98 | array CONST_VAL[i].VALUE. That is fed into substitute_and_fold for | |
99 | final substitution and folding. | |
100 | ||
807e902e KZ |
101 | This algorithm uses wide-ints at the max precision of the target. |
102 | This means that, with one uninteresting exception, variables with | |
103 | UNSIGNED types never go to VARYING because the bits above the | |
104 | precision of the type of the variable are always zero. The | |
105 | uninteresting case is a variable of UNSIGNED type that has the | |
106 | maximum precision of the target. Such variables can go to VARYING, | |
107 | but this causes no loss of infomation since these variables will | |
108 | never be extended. | |
109 | ||
6de9cd9a DN |
110 | References: |
111 | ||
112 | Constant propagation with conditional branches, | |
113 | Wegman and Zadeck, ACM TOPLAS 13(2):181-210. | |
114 | ||
115 | Building an Optimizing Compiler, | |
116 | Robert Morgan, Butterworth-Heinemann, 1998, Section 8.9. | |
117 | ||
118 | Advanced Compiler Design and Implementation, | |
119 | Steven Muchnick, Morgan Kaufmann, 1997, Section 12.6 */ | |
120 | ||
121 | #include "config.h" | |
122 | #include "system.h" | |
123 | #include "coretypes.h" | |
124 | #include "tm.h" | |
6de9cd9a | 125 | #include "tree.h" |
d8a2d370 | 126 | #include "stor-layout.h" |
750628d8 | 127 | #include "flags.h" |
6de9cd9a | 128 | #include "tm_p.h" |
60393bbc AM |
129 | #include "predict.h" |
130 | #include "vec.h" | |
83685514 AM |
131 | #include "hashtab.h" |
132 | #include "hash-set.h" | |
83685514 AM |
133 | #include "machmode.h" |
134 | #include "hard-reg-set.h" | |
135 | #include "input.h" | |
750628d8 | 136 | #include "function.h" |
60393bbc AM |
137 | #include "dominance.h" |
138 | #include "cfg.h" | |
139 | #include "basic-block.h" | |
cf835838 | 140 | #include "gimple-pretty-print.h" |
2fb9a547 AM |
141 | #include "hash-table.h" |
142 | #include "tree-ssa-alias.h" | |
143 | #include "internal-fn.h" | |
144 | #include "gimple-fold.h" | |
145 | #include "tree-eh.h" | |
146 | #include "gimple-expr.h" | |
147 | #include "is-a.h" | |
18f429e2 | 148 | #include "gimple.h" |
45b0be94 | 149 | #include "gimplify.h" |
5be5c238 | 150 | #include "gimple-iterator.h" |
442b4905 AM |
151 | #include "gimple-ssa.h" |
152 | #include "tree-cfg.h" | |
153 | #include "tree-phinodes.h" | |
154 | #include "ssa-iterators.h" | |
d8a2d370 | 155 | #include "stringpool.h" |
442b4905 | 156 | #include "tree-ssanames.h" |
6de9cd9a | 157 | #include "tree-pass.h" |
750628d8 | 158 | #include "tree-ssa-propagate.h" |
53a8f709 | 159 | #include "value-prof.h" |
750628d8 | 160 | #include "langhooks.h" |
ae3df618 | 161 | #include "target.h" |
718f9c0f | 162 | #include "diagnostic-core.h" |
74fe548b | 163 | #include "dbgcnt.h" |
1fed1006 | 164 | #include "params.h" |
807e902e | 165 | #include "wide-int-print.h" |
9b2b7279 | 166 | #include "builtins.h" |
6de9cd9a DN |
167 | |
168 | ||
169 | /* Possible lattice values. */ | |
170 | typedef enum | |
171 | { | |
106dec71 | 172 | UNINITIALIZED, |
6de9cd9a DN |
173 | UNDEFINED, |
174 | CONSTANT, | |
175 | VARYING | |
0bca51f0 | 176 | } ccp_lattice_t; |
6de9cd9a | 177 | |
11478306 | 178 | struct ccp_prop_value_t { |
455e6d5b RG |
179 | /* Lattice value. */ |
180 | ccp_lattice_t lattice_val; | |
181 | ||
182 | /* Propagated value. */ | |
183 | tree value; | |
0b4b14ac | 184 | |
807e902e KZ |
185 | /* Mask that applies to the propagated value during CCP. For X |
186 | with a CONSTANT lattice value X & ~mask == value & ~mask. The | |
187 | zero bits in the mask cover constant values. The ones mean no | |
188 | information. */ | |
189 | widest_int mask; | |
455e6d5b RG |
190 | }; |
191 | ||
0bca51f0 DN |
192 | /* Array of propagated constant values. After propagation, |
193 | CONST_VAL[I].VALUE holds the constant value for SSA_NAME(I). If | |
194 | the constant is held in an SSA name representing a memory store | |
38635499 DN |
195 | (i.e., a VDEF), CONST_VAL[I].MEM_REF will contain the actual |
196 | memory reference used to store (i.e., the LHS of the assignment | |
197 | doing the store). */ | |
11478306 | 198 | static ccp_prop_value_t *const_val; |
e91c8ed6 | 199 | static unsigned n_const_val; |
6de9cd9a | 200 | |
11478306 | 201 | static void canonicalize_value (ccp_prop_value_t *); |
f61e18ec | 202 | static bool ccp_fold_stmt (gimple_stmt_iterator *); |
25e20805 | 203 | |
0bca51f0 | 204 | /* Dump constant propagation value VAL to file OUTF prefixed by PREFIX. */ |
95eec0d6 DB |
205 | |
206 | static void | |
11478306 | 207 | dump_lattice_value (FILE *outf, const char *prefix, ccp_prop_value_t val) |
95eec0d6 | 208 | { |
750628d8 | 209 | switch (val.lattice_val) |
95eec0d6 | 210 | { |
0bca51f0 DN |
211 | case UNINITIALIZED: |
212 | fprintf (outf, "%sUNINITIALIZED", prefix); | |
213 | break; | |
750628d8 DN |
214 | case UNDEFINED: |
215 | fprintf (outf, "%sUNDEFINED", prefix); | |
216 | break; | |
217 | case VARYING: | |
218 | fprintf (outf, "%sVARYING", prefix); | |
219 | break; | |
750628d8 | 220 | case CONSTANT: |
0b4b14ac | 221 | if (TREE_CODE (val.value) != INTEGER_CST |
807e902e | 222 | || val.mask == 0) |
c38cdd3f EB |
223 | { |
224 | fprintf (outf, "%sCONSTANT ", prefix); | |
225 | print_generic_expr (outf, val.value, dump_flags); | |
226 | } | |
0b4b14ac RG |
227 | else |
228 | { | |
807e902e KZ |
229 | widest_int cval = wi::bit_and_not (wi::to_widest (val.value), |
230 | val.mask); | |
231 | fprintf (outf, "%sCONSTANT ", prefix); | |
232 | print_hex (cval, outf); | |
233 | fprintf (outf, " ("); | |
234 | print_hex (val.mask, outf); | |
235 | fprintf (outf, ")"); | |
0b4b14ac | 236 | } |
750628d8 DN |
237 | break; |
238 | default: | |
1e128c5f | 239 | gcc_unreachable (); |
750628d8 | 240 | } |
95eec0d6 | 241 | } |
6de9cd9a | 242 | |
6de9cd9a | 243 | |
0bca51f0 DN |
244 | /* Print lattice value VAL to stderr. */ |
245 | ||
11478306 | 246 | void debug_lattice_value (ccp_prop_value_t val); |
0bca51f0 | 247 | |
24e47c76 | 248 | DEBUG_FUNCTION void |
11478306 | 249 | debug_lattice_value (ccp_prop_value_t val) |
0bca51f0 DN |
250 | { |
251 | dump_lattice_value (stderr, "", val); | |
252 | fprintf (stderr, "\n"); | |
253 | } | |
6de9cd9a | 254 | |
807e902e KZ |
255 | /* Extend NONZERO_BITS to a full mask, with the upper bits being set. */ |
256 | ||
257 | static widest_int | |
258 | extend_mask (const wide_int &nonzero_bits) | |
259 | { | |
260 | return (wi::mask <widest_int> (wi::get_precision (nonzero_bits), true) | |
261 | | widest_int::from (nonzero_bits, UNSIGNED)); | |
262 | } | |
6de9cd9a | 263 | |
0bca51f0 DN |
264 | /* Compute a default value for variable VAR and store it in the |
265 | CONST_VAL array. The following rules are used to get default | |
266 | values: | |
95eec0d6 | 267 | |
0bca51f0 DN |
268 | 1- Global and static variables that are declared constant are |
269 | considered CONSTANT. | |
270 | ||
271 | 2- Any other value is considered UNDEFINED. This is useful when | |
750628d8 DN |
272 | considering PHI nodes. PHI arguments that are undefined do not |
273 | change the constant value of the PHI node, which allows for more | |
0bca51f0 | 274 | constants to be propagated. |
6de9cd9a | 275 | |
caf55296 | 276 | 3- Variables defined by statements other than assignments and PHI |
0bca51f0 | 277 | nodes are considered VARYING. |
6de9cd9a | 278 | |
caf55296 | 279 | 4- Initial values of variables that are not GIMPLE registers are |
106dec71 | 280 | considered VARYING. */ |
6de9cd9a | 281 | |
11478306 | 282 | static ccp_prop_value_t |
0bca51f0 DN |
283 | get_default_value (tree var) |
284 | { | |
11478306 | 285 | ccp_prop_value_t val = { UNINITIALIZED, NULL_TREE, 0 }; |
e8114fba RG |
286 | gimple stmt; |
287 | ||
288 | stmt = SSA_NAME_DEF_STMT (var); | |
289 | ||
290 | if (gimple_nop_p (stmt)) | |
6de9cd9a | 291 | { |
e8114fba RG |
292 | /* Variables defined by an empty statement are those used |
293 | before being initialized. If VAR is a local variable, we | |
294 | can assume initially that it is UNDEFINED, otherwise we must | |
295 | consider it VARYING. */ | |
ea057359 RG |
296 | if (!virtual_operand_p (var) |
297 | && TREE_CODE (SSA_NAME_VAR (var)) == VAR_DECL) | |
e8114fba RG |
298 | val.lattice_val = UNDEFINED; |
299 | else | |
0b4b14ac RG |
300 | { |
301 | val.lattice_val = VARYING; | |
807e902e | 302 | val.mask = -1; |
c853f62a JJ |
303 | if (flag_tree_bit_ccp) |
304 | { | |
807e902e KZ |
305 | wide_int nonzero_bits = get_nonzero_bits (var); |
306 | if (nonzero_bits != -1) | |
c853f62a JJ |
307 | { |
308 | val.lattice_val = CONSTANT; | |
309 | val.value = build_zero_cst (TREE_TYPE (var)); | |
807e902e | 310 | val.mask = extend_mask (nonzero_bits); |
c853f62a JJ |
311 | } |
312 | } | |
0b4b14ac | 313 | } |
6de9cd9a | 314 | } |
d71ff3fa | 315 | else if (is_gimple_assign (stmt)) |
750628d8 | 316 | { |
e8114fba RG |
317 | tree cst; |
318 | if (gimple_assign_single_p (stmt) | |
319 | && DECL_P (gimple_assign_rhs1 (stmt)) | |
320 | && (cst = get_symbol_constant_value (gimple_assign_rhs1 (stmt)))) | |
0bca51f0 | 321 | { |
e8114fba RG |
322 | val.lattice_val = CONSTANT; |
323 | val.value = cst; | |
0bca51f0 DN |
324 | } |
325 | else | |
d71ff3fa ZZ |
326 | { |
327 | /* Any other variable defined by an assignment is considered | |
328 | UNDEFINED. */ | |
329 | val.lattice_val = UNDEFINED; | |
330 | } | |
331 | } | |
332 | else if ((is_gimple_call (stmt) | |
333 | && gimple_call_lhs (stmt) != NULL_TREE) | |
334 | || gimple_code (stmt) == GIMPLE_PHI) | |
335 | { | |
336 | /* A variable defined by a call or a PHI node is considered | |
337 | UNDEFINED. */ | |
338 | val.lattice_val = UNDEFINED; | |
e8114fba RG |
339 | } |
340 | else | |
341 | { | |
342 | /* Otherwise, VAR will never take on a constant value. */ | |
343 | val.lattice_val = VARYING; | |
807e902e | 344 | val.mask = -1; |
750628d8 | 345 | } |
6de9cd9a | 346 | |
750628d8 DN |
347 | return val; |
348 | } | |
6de9cd9a | 349 | |
6de9cd9a | 350 | |
106dec71 | 351 | /* Get the constant value associated with variable VAR. */ |
6de9cd9a | 352 | |
11478306 | 353 | static inline ccp_prop_value_t * |
106dec71 | 354 | get_value (tree var) |
0bca51f0 | 355 | { |
11478306 | 356 | ccp_prop_value_t *val; |
106dec71 | 357 | |
e91c8ed6 RB |
358 | if (const_val == NULL |
359 | || SSA_NAME_VERSION (var) >= n_const_val) | |
ed97ddc6 RG |
360 | return NULL; |
361 | ||
362 | val = &const_val[SSA_NAME_VERSION (var)]; | |
106dec71 | 363 | if (val->lattice_val == UNINITIALIZED) |
6de9cd9a DN |
364 | *val = get_default_value (var); |
365 | ||
846abd0d | 366 | canonicalize_value (val); |
25e20805 | 367 | |
6de9cd9a DN |
368 | return val; |
369 | } | |
370 | ||
84d77ca6 RG |
371 | /* Return the constant tree value associated with VAR. */ |
372 | ||
373 | static inline tree | |
374 | get_constant_value (tree var) | |
375 | { | |
11478306 | 376 | ccp_prop_value_t *val; |
e196b221 JH |
377 | if (TREE_CODE (var) != SSA_NAME) |
378 | { | |
379 | if (is_gimple_min_invariant (var)) | |
380 | return var; | |
381 | return NULL_TREE; | |
382 | } | |
383 | val = get_value (var); | |
0b4b14ac RG |
384 | if (val |
385 | && val->lattice_val == CONSTANT | |
386 | && (TREE_CODE (val->value) != INTEGER_CST | |
807e902e | 387 | || val->mask == 0)) |
84d77ca6 RG |
388 | return val->value; |
389 | return NULL_TREE; | |
390 | } | |
391 | ||
106dec71 ZD |
392 | /* Sets the value associated with VAR to VARYING. */ |
393 | ||
394 | static inline void | |
395 | set_value_varying (tree var) | |
396 | { | |
11478306 | 397 | ccp_prop_value_t *val = &const_val[SSA_NAME_VERSION (var)]; |
106dec71 ZD |
398 | |
399 | val->lattice_val = VARYING; | |
400 | val->value = NULL_TREE; | |
807e902e | 401 | val->mask = -1; |
106dec71 | 402 | } |
6de9cd9a | 403 | |
fbb5445b L |
404 | /* For float types, modify the value of VAL to make ccp work correctly |
405 | for non-standard values (-0, NaN): | |
406 | ||
407 | If HONOR_SIGNED_ZEROS is false, and VAL = -0, we canonicalize it to 0. | |
408 | If HONOR_NANS is false, and VAL is NaN, we canonicalize it to UNDEFINED. | |
409 | This is to fix the following problem (see PR 29921): Suppose we have | |
410 | ||
411 | x = 0.0 * y | |
412 | ||
413 | and we set value of y to NaN. This causes value of x to be set to NaN. | |
414 | When we later determine that y is in fact VARYING, fold uses the fact | |
415 | that HONOR_NANS is false, and we try to change the value of x to 0, | |
416 | causing an ICE. With HONOR_NANS being false, the real appearance of | |
417 | NaN would cause undefined behavior, though, so claiming that y (and x) | |
846abd0d RB |
418 | are UNDEFINED initially is correct. |
419 | ||
420 | For other constants, make sure to drop TREE_OVERFLOW. */ | |
fbb5445b L |
421 | |
422 | static void | |
11478306 | 423 | canonicalize_value (ccp_prop_value_t *val) |
fbb5445b | 424 | { |
ef4bddc2 | 425 | machine_mode mode; |
fbb5445b L |
426 | tree type; |
427 | REAL_VALUE_TYPE d; | |
428 | ||
846abd0d RB |
429 | if (val->lattice_val != CONSTANT) |
430 | return; | |
431 | ||
432 | if (TREE_OVERFLOW_P (val->value)) | |
433 | val->value = drop_tree_overflow (val->value); | |
434 | ||
435 | if (TREE_CODE (val->value) != REAL_CST) | |
fbb5445b L |
436 | return; |
437 | ||
438 | d = TREE_REAL_CST (val->value); | |
439 | type = TREE_TYPE (val->value); | |
440 | mode = TYPE_MODE (type); | |
441 | ||
442 | if (!HONOR_SIGNED_ZEROS (mode) | |
443 | && REAL_VALUE_MINUS_ZERO (d)) | |
444 | { | |
445 | val->value = build_real (type, dconst0); | |
446 | return; | |
447 | } | |
448 | ||
449 | if (!HONOR_NANS (mode) | |
450 | && REAL_VALUE_ISNAN (d)) | |
451 | { | |
452 | val->lattice_val = UNDEFINED; | |
453 | val->value = NULL; | |
fbb5445b L |
454 | return; |
455 | } | |
456 | } | |
457 | ||
0b4b14ac RG |
458 | /* Return whether the lattice transition is valid. */ |
459 | ||
460 | static bool | |
11478306 | 461 | valid_lattice_transition (ccp_prop_value_t old_val, ccp_prop_value_t new_val) |
0b4b14ac RG |
462 | { |
463 | /* Lattice transitions must always be monotonically increasing in | |
464 | value. */ | |
465 | if (old_val.lattice_val < new_val.lattice_val) | |
466 | return true; | |
467 | ||
468 | if (old_val.lattice_val != new_val.lattice_val) | |
469 | return false; | |
470 | ||
471 | if (!old_val.value && !new_val.value) | |
472 | return true; | |
473 | ||
474 | /* Now both lattice values are CONSTANT. */ | |
475 | ||
95cbf851 RG |
476 | /* Allow transitioning from PHI <&x, not executable> == &x |
477 | to PHI <&x, &y> == common alignment. */ | |
0b4b14ac RG |
478 | if (TREE_CODE (old_val.value) != INTEGER_CST |
479 | && TREE_CODE (new_val.value) == INTEGER_CST) | |
480 | return true; | |
481 | ||
482 | /* Bit-lattices have to agree in the still valid bits. */ | |
483 | if (TREE_CODE (old_val.value) == INTEGER_CST | |
484 | && TREE_CODE (new_val.value) == INTEGER_CST) | |
807e902e KZ |
485 | return (wi::bit_and_not (wi::to_widest (old_val.value), new_val.mask) |
486 | == wi::bit_and_not (wi::to_widest (new_val.value), new_val.mask)); | |
0b4b14ac RG |
487 | |
488 | /* Otherwise constant values have to agree. */ | |
489 | return operand_equal_p (old_val.value, new_val.value, 0); | |
490 | } | |
491 | ||
0bca51f0 DN |
492 | /* Set the value for variable VAR to NEW_VAL. Return true if the new |
493 | value is different from VAR's previous value. */ | |
6de9cd9a | 494 | |
750628d8 | 495 | static bool |
11478306 | 496 | set_lattice_value (tree var, ccp_prop_value_t new_val) |
6de9cd9a | 497 | { |
7a95d078 | 498 | /* We can deal with old UNINITIALIZED values just fine here. */ |
11478306 | 499 | ccp_prop_value_t *old_val = &const_val[SSA_NAME_VERSION (var)]; |
0bca51f0 | 500 | |
846abd0d | 501 | canonicalize_value (&new_val); |
fbb5445b | 502 | |
0b4b14ac RG |
503 | /* We have to be careful to not go up the bitwise lattice |
504 | represented by the mask. | |
505 | ??? This doesn't seem to be the best place to enforce this. */ | |
506 | if (new_val.lattice_val == CONSTANT | |
507 | && old_val->lattice_val == CONSTANT | |
508 | && TREE_CODE (new_val.value) == INTEGER_CST | |
509 | && TREE_CODE (old_val->value) == INTEGER_CST) | |
510 | { | |
807e902e KZ |
511 | widest_int diff = (wi::to_widest (new_val.value) |
512 | ^ wi::to_widest (old_val->value)); | |
27bcd47c | 513 | new_val.mask = new_val.mask | old_val->mask | diff; |
0b4b14ac | 514 | } |
106dec71 | 515 | |
0b4b14ac | 516 | gcc_assert (valid_lattice_transition (*old_val, new_val)); |
0bca51f0 | 517 | |
0b4b14ac RG |
518 | /* If *OLD_VAL and NEW_VAL are the same, return false to inform the |
519 | caller that this was a non-transition. */ | |
520 | if (old_val->lattice_val != new_val.lattice_val | |
521 | || (new_val.lattice_val == CONSTANT | |
522 | && TREE_CODE (new_val.value) == INTEGER_CST | |
523 | && (TREE_CODE (old_val->value) != INTEGER_CST | |
27bcd47c | 524 | || new_val.mask != old_val->mask))) |
6de9cd9a | 525 | { |
0b4b14ac RG |
526 | /* ??? We would like to delay creation of INTEGER_CSTs from |
527 | partially constants here. */ | |
528 | ||
750628d8 DN |
529 | if (dump_file && (dump_flags & TDF_DETAILS)) |
530 | { | |
0bca51f0 | 531 | dump_lattice_value (dump_file, "Lattice value changed to ", new_val); |
106dec71 | 532 | fprintf (dump_file, ". Adding SSA edges to worklist.\n"); |
750628d8 DN |
533 | } |
534 | ||
0bca51f0 DN |
535 | *old_val = new_val; |
536 | ||
7a95d078 | 537 | gcc_assert (new_val.lattice_val != UNINITIALIZED); |
106dec71 | 538 | return true; |
6de9cd9a | 539 | } |
750628d8 DN |
540 | |
541 | return false; | |
6de9cd9a DN |
542 | } |
543 | ||
11478306 JH |
544 | static ccp_prop_value_t get_value_for_expr (tree, bool); |
545 | static ccp_prop_value_t bit_value_binop (enum tree_code, tree, tree, tree); | |
807e902e KZ |
546 | static void bit_value_binop_1 (enum tree_code, tree, widest_int *, widest_int *, |
547 | tree, const widest_int &, const widest_int &, | |
548 | tree, const widest_int &, const widest_int &); | |
0b4b14ac | 549 | |
807e902e | 550 | /* Return a widest_int that can be used for bitwise simplifications |
0b4b14ac RG |
551 | from VAL. */ |
552 | ||
807e902e | 553 | static widest_int |
11478306 | 554 | value_to_wide_int (ccp_prop_value_t val) |
0b4b14ac RG |
555 | { |
556 | if (val.value | |
557 | && TREE_CODE (val.value) == INTEGER_CST) | |
807e902e KZ |
558 | return wi::to_widest (val.value); |
559 | ||
560 | return 0; | |
0b4b14ac RG |
561 | } |
562 | ||
563 | /* Return the value for the address expression EXPR based on alignment | |
564 | information. */ | |
7a95d078 | 565 | |
11478306 | 566 | static ccp_prop_value_t |
0b4b14ac RG |
567 | get_value_from_alignment (tree expr) |
568 | { | |
d1f4e15f | 569 | tree type = TREE_TYPE (expr); |
11478306 | 570 | ccp_prop_value_t val; |
d1f4e15f RG |
571 | unsigned HOST_WIDE_INT bitpos; |
572 | unsigned int align; | |
0b4b14ac RG |
573 | |
574 | gcc_assert (TREE_CODE (expr) == ADDR_EXPR); | |
575 | ||
a0969677 | 576 | get_pointer_alignment_1 (expr, &align, &bitpos); |
27bcd47c | 577 | val.mask = (POINTER_TYPE_P (type) || TYPE_UNSIGNED (type) |
807e902e KZ |
578 | ? wi::mask <widest_int> (TYPE_PRECISION (type), false) |
579 | : -1).and_not (align / BITS_PER_UNIT - 1); | |
580 | val.lattice_val = val.mask == -1 ? VARYING : CONSTANT; | |
d1f4e15f | 581 | if (val.lattice_val == CONSTANT) |
807e902e | 582 | val.value = build_int_cstu (type, bitpos / BITS_PER_UNIT); |
0b4b14ac | 583 | else |
d1f4e15f | 584 | val.value = NULL_TREE; |
0b4b14ac RG |
585 | |
586 | return val; | |
587 | } | |
588 | ||
589 | /* Return the value for the tree operand EXPR. If FOR_BITS_P is true | |
590 | return constant bits extracted from alignment information for | |
591 | invariant addresses. */ | |
592 | ||
11478306 | 593 | static ccp_prop_value_t |
0b4b14ac | 594 | get_value_for_expr (tree expr, bool for_bits_p) |
7a95d078 | 595 | { |
11478306 | 596 | ccp_prop_value_t val; |
7a95d078 RG |
597 | |
598 | if (TREE_CODE (expr) == SSA_NAME) | |
0b4b14ac RG |
599 | { |
600 | val = *get_value (expr); | |
601 | if (for_bits_p | |
602 | && val.lattice_val == CONSTANT | |
603 | && TREE_CODE (val.value) == ADDR_EXPR) | |
604 | val = get_value_from_alignment (val.value); | |
605 | } | |
606 | else if (is_gimple_min_invariant (expr) | |
607 | && (!for_bits_p || TREE_CODE (expr) != ADDR_EXPR)) | |
7a95d078 RG |
608 | { |
609 | val.lattice_val = CONSTANT; | |
610 | val.value = expr; | |
807e902e | 611 | val.mask = 0; |
846abd0d | 612 | canonicalize_value (&val); |
7a95d078 | 613 | } |
0b4b14ac RG |
614 | else if (TREE_CODE (expr) == ADDR_EXPR) |
615 | val = get_value_from_alignment (expr); | |
7a95d078 RG |
616 | else |
617 | { | |
618 | val.lattice_val = VARYING; | |
807e902e | 619 | val.mask = -1; |
7a95d078 RG |
620 | val.value = NULL_TREE; |
621 | } | |
7a95d078 RG |
622 | return val; |
623 | } | |
624 | ||
0bca51f0 | 625 | /* Return the likely CCP lattice value for STMT. |
6de9cd9a | 626 | |
750628d8 | 627 | If STMT has no operands, then return CONSTANT. |
6de9cd9a | 628 | |
7f879c96 RG |
629 | Else if undefinedness of operands of STMT cause its value to be |
630 | undefined, then return UNDEFINED. | |
6de9cd9a | 631 | |
750628d8 | 632 | Else if any operands of STMT are constants, then return CONSTANT. |
6de9cd9a | 633 | |
750628d8 | 634 | Else return VARYING. */ |
6de9cd9a | 635 | |
0bca51f0 | 636 | static ccp_lattice_t |
726a989a | 637 | likely_value (gimple stmt) |
750628d8 | 638 | { |
7f879c96 | 639 | bool has_constant_operand, has_undefined_operand, all_undefined_operands; |
750628d8 DN |
640 | tree use; |
641 | ssa_op_iter iter; | |
e8114fba | 642 | unsigned i; |
6de9cd9a | 643 | |
e0c68ce9 | 644 | enum gimple_code code = gimple_code (stmt); |
726a989a RB |
645 | |
646 | /* This function appears to be called only for assignments, calls, | |
647 | conditionals, and switches, due to the logic in visit_stmt. */ | |
648 | gcc_assert (code == GIMPLE_ASSIGN | |
649 | || code == GIMPLE_CALL | |
650 | || code == GIMPLE_COND | |
651 | || code == GIMPLE_SWITCH); | |
0bca51f0 DN |
652 | |
653 | /* If the statement has volatile operands, it won't fold to a | |
654 | constant value. */ | |
726a989a | 655 | if (gimple_has_volatile_ops (stmt)) |
0bca51f0 DN |
656 | return VARYING; |
657 | ||
726a989a | 658 | /* Arrive here for more complex cases. */ |
106dec71 | 659 | has_constant_operand = false; |
7f879c96 RG |
660 | has_undefined_operand = false; |
661 | all_undefined_operands = true; | |
e8114fba | 662 | FOR_EACH_SSA_TREE_OPERAND (use, stmt, iter, SSA_OP_USE) |
750628d8 | 663 | { |
11478306 | 664 | ccp_prop_value_t *val = get_value (use); |
750628d8 | 665 | |
106dec71 | 666 | if (val->lattice_val == UNDEFINED) |
7f879c96 RG |
667 | has_undefined_operand = true; |
668 | else | |
669 | all_undefined_operands = false; | |
0bca51f0 | 670 | |
750628d8 | 671 | if (val->lattice_val == CONSTANT) |
106dec71 | 672 | has_constant_operand = true; |
6de9cd9a | 673 | } |
750628d8 | 674 | |
5006671f RG |
675 | /* There may be constants in regular rhs operands. For calls we |
676 | have to ignore lhs, fndecl and static chain, otherwise only | |
677 | the lhs. */ | |
678 | for (i = (is_gimple_call (stmt) ? 2 : 0) + gimple_has_lhs (stmt); | |
e8114fba RG |
679 | i < gimple_num_ops (stmt); ++i) |
680 | { | |
681 | tree op = gimple_op (stmt, i); | |
682 | if (!op || TREE_CODE (op) == SSA_NAME) | |
683 | continue; | |
684 | if (is_gimple_min_invariant (op)) | |
685 | has_constant_operand = true; | |
686 | } | |
687 | ||
1cdaa211 RG |
688 | if (has_constant_operand) |
689 | all_undefined_operands = false; | |
690 | ||
74bf76ed JJ |
691 | if (has_undefined_operand |
692 | && code == GIMPLE_CALL | |
693 | && gimple_call_internal_p (stmt)) | |
694 | switch (gimple_call_internal_fn (stmt)) | |
695 | { | |
696 | /* These 3 builtins use the first argument just as a magic | |
697 | way how to find out a decl uid. */ | |
698 | case IFN_GOMP_SIMD_LANE: | |
699 | case IFN_GOMP_SIMD_VF: | |
700 | case IFN_GOMP_SIMD_LAST_LANE: | |
701 | has_undefined_operand = false; | |
702 | break; | |
703 | default: | |
704 | break; | |
705 | } | |
706 | ||
7f879c96 RG |
707 | /* If the operation combines operands like COMPLEX_EXPR make sure to |
708 | not mark the result UNDEFINED if only one part of the result is | |
709 | undefined. */ | |
726a989a | 710 | if (has_undefined_operand && all_undefined_operands) |
7f879c96 | 711 | return UNDEFINED; |
726a989a | 712 | else if (code == GIMPLE_ASSIGN && has_undefined_operand) |
7f879c96 | 713 | { |
726a989a | 714 | switch (gimple_assign_rhs_code (stmt)) |
7f879c96 RG |
715 | { |
716 | /* Unary operators are handled with all_undefined_operands. */ | |
717 | case PLUS_EXPR: | |
718 | case MINUS_EXPR: | |
7f879c96 | 719 | case POINTER_PLUS_EXPR: |
7f879c96 RG |
720 | /* Not MIN_EXPR, MAX_EXPR. One VARYING operand may be selected. |
721 | Not bitwise operators, one VARYING operand may specify the | |
722 | result completely. Not logical operators for the same reason. | |
0cedb9e9 RG |
723 | Not COMPLEX_EXPR as one VARYING operand makes the result partly |
724 | not UNDEFINED. Not *DIV_EXPR, comparisons and shifts because | |
725 | the undefined operand may be promoted. */ | |
7f879c96 RG |
726 | return UNDEFINED; |
727 | ||
95cbf851 RG |
728 | case ADDR_EXPR: |
729 | /* If any part of an address is UNDEFINED, like the index | |
730 | of an ARRAY_EXPR, then treat the result as UNDEFINED. */ | |
731 | return UNDEFINED; | |
732 | ||
7f879c96 RG |
733 | default: |
734 | ; | |
735 | } | |
736 | } | |
737 | /* If there was an UNDEFINED operand but the result may be not UNDEFINED | |
6ad024b4 RG |
738 | fall back to CONSTANT. During iteration UNDEFINED may still drop |
739 | to CONSTANT. */ | |
7f879c96 | 740 | if (has_undefined_operand) |
6ad024b4 | 741 | return CONSTANT; |
7f879c96 | 742 | |
e8114fba RG |
743 | /* We do not consider virtual operands here -- load from read-only |
744 | memory may have only VARYING virtual operands, but still be | |
745 | constant. */ | |
106dec71 | 746 | if (has_constant_operand |
e8114fba | 747 | || gimple_references_memory_p (stmt)) |
0bca51f0 DN |
748 | return CONSTANT; |
749 | ||
106dec71 | 750 | return VARYING; |
6de9cd9a DN |
751 | } |
752 | ||
106dec71 ZD |
753 | /* Returns true if STMT cannot be constant. */ |
754 | ||
755 | static bool | |
726a989a | 756 | surely_varying_stmt_p (gimple stmt) |
106dec71 ZD |
757 | { |
758 | /* If the statement has operands that we cannot handle, it cannot be | |
759 | constant. */ | |
726a989a | 760 | if (gimple_has_volatile_ops (stmt)) |
106dec71 ZD |
761 | return true; |
762 | ||
174ef36d | 763 | /* If it is a call and does not return a value or is not a |
8fcbce72 JJ |
764 | builtin and not an indirect call or a call to function with |
765 | assume_aligned/alloc_align attribute, it is varying. */ | |
726a989a | 766 | if (is_gimple_call (stmt)) |
174ef36d | 767 | { |
8fcbce72 | 768 | tree fndecl, fntype = gimple_call_fntype (stmt); |
174ef36d RG |
769 | if (!gimple_call_lhs (stmt) |
770 | || ((fndecl = gimple_call_fndecl (stmt)) != NULL_TREE | |
8fcbce72 JJ |
771 | && !DECL_BUILT_IN (fndecl) |
772 | && !lookup_attribute ("assume_aligned", | |
773 | TYPE_ATTRIBUTES (fntype)) | |
774 | && !lookup_attribute ("alloc_align", | |
775 | TYPE_ATTRIBUTES (fntype)))) | |
174ef36d RG |
776 | return true; |
777 | } | |
106dec71 | 778 | |
e8114fba | 779 | /* Any other store operation is not interesting. */ |
5006671f | 780 | else if (gimple_vdef (stmt)) |
e8114fba RG |
781 | return true; |
782 | ||
106dec71 ZD |
783 | /* Anything other than assignments and conditional jumps are not |
784 | interesting for CCP. */ | |
726a989a | 785 | if (gimple_code (stmt) != GIMPLE_ASSIGN |
174ef36d RG |
786 | && gimple_code (stmt) != GIMPLE_COND |
787 | && gimple_code (stmt) != GIMPLE_SWITCH | |
788 | && gimple_code (stmt) != GIMPLE_CALL) | |
106dec71 ZD |
789 | return true; |
790 | ||
791 | return false; | |
792 | } | |
6de9cd9a | 793 | |
750628d8 | 794 | /* Initialize local data structures for CCP. */ |
6de9cd9a DN |
795 | |
796 | static void | |
750628d8 | 797 | ccp_initialize (void) |
6de9cd9a | 798 | { |
750628d8 | 799 | basic_block bb; |
6de9cd9a | 800 | |
e91c8ed6 | 801 | n_const_val = num_ssa_names; |
11478306 | 802 | const_val = XCNEWVEC (ccp_prop_value_t, n_const_val); |
6de9cd9a | 803 | |
750628d8 | 804 | /* Initialize simulation flags for PHI nodes and statements. */ |
11cd3bed | 805 | FOR_EACH_BB_FN (bb, cfun) |
6de9cd9a | 806 | { |
726a989a | 807 | gimple_stmt_iterator i; |
6de9cd9a | 808 | |
726a989a | 809 | for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i)) |
750628d8 | 810 | { |
726a989a | 811 | gimple stmt = gsi_stmt (i); |
cd6ea7a2 RH |
812 | bool is_varying; |
813 | ||
814 | /* If the statement is a control insn, then we do not | |
815 | want to avoid simulating the statement once. Failure | |
816 | to do so means that those edges will never get added. */ | |
817 | if (stmt_ends_bb_p (stmt)) | |
818 | is_varying = false; | |
819 | else | |
820 | is_varying = surely_varying_stmt_p (stmt); | |
6de9cd9a | 821 | |
106dec71 | 822 | if (is_varying) |
750628d8 | 823 | { |
0bca51f0 DN |
824 | tree def; |
825 | ssa_op_iter iter; | |
826 | ||
827 | /* If the statement will not produce a constant, mark | |
828 | all its outputs VARYING. */ | |
829 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS) | |
e8114fba | 830 | set_value_varying (def); |
750628d8 | 831 | } |
726a989a | 832 | prop_set_simulate_again (stmt, !is_varying); |
750628d8 | 833 | } |
6de9cd9a DN |
834 | } |
835 | ||
726a989a RB |
836 | /* Now process PHI nodes. We never clear the simulate_again flag on |
837 | phi nodes, since we do not know which edges are executable yet, | |
838 | except for phi nodes for virtual operands when we do not do store ccp. */ | |
11cd3bed | 839 | FOR_EACH_BB_FN (bb, cfun) |
6de9cd9a | 840 | { |
726a989a | 841 | gimple_stmt_iterator i; |
750628d8 | 842 | |
726a989a RB |
843 | for (i = gsi_start_phis (bb); !gsi_end_p (i); gsi_next (&i)) |
844 | { | |
845 | gimple phi = gsi_stmt (i); | |
846 | ||
ea057359 | 847 | if (virtual_operand_p (gimple_phi_result (phi))) |
726a989a | 848 | prop_set_simulate_again (phi, false); |
106dec71 | 849 | else |
726a989a | 850 | prop_set_simulate_again (phi, true); |
750628d8 | 851 | } |
6de9cd9a | 852 | } |
750628d8 | 853 | } |
6de9cd9a | 854 | |
74fe548b XDL |
855 | /* Debug count support. Reset the values of ssa names |
856 | VARYING when the total number ssa names analyzed is | |
857 | beyond the debug count specified. */ | |
858 | ||
859 | static void | |
860 | do_dbg_cnt (void) | |
861 | { | |
862 | unsigned i; | |
863 | for (i = 0; i < num_ssa_names; i++) | |
864 | { | |
865 | if (!dbg_cnt (ccp)) | |
866 | { | |
867 | const_val[i].lattice_val = VARYING; | |
807e902e | 868 | const_val[i].mask = -1; |
74fe548b XDL |
869 | const_val[i].value = NULL_TREE; |
870 | } | |
871 | } | |
872 | } | |
873 | ||
6de9cd9a | 874 | |
0bca51f0 | 875 | /* Do final substitution of propagated values, cleanup the flowgraph and |
b8698a0f | 876 | free allocated storage. |
6de9cd9a | 877 | |
3253eafb JH |
878 | Return TRUE when something was optimized. */ |
879 | ||
880 | static bool | |
0bca51f0 | 881 | ccp_finalize (void) |
6de9cd9a | 882 | { |
74fe548b | 883 | bool something_changed; |
1be38ccb | 884 | unsigned i; |
74fe548b XDL |
885 | |
886 | do_dbg_cnt (); | |
1be38ccb RG |
887 | |
888 | /* Derive alignment and misalignment information from partially | |
c853f62a JJ |
889 | constant pointers in the lattice or nonzero bits from partially |
890 | constant integers. */ | |
1be38ccb RG |
891 | for (i = 1; i < num_ssa_names; ++i) |
892 | { | |
893 | tree name = ssa_name (i); | |
11478306 | 894 | ccp_prop_value_t *val; |
1be38ccb RG |
895 | unsigned int tem, align; |
896 | ||
897 | if (!name | |
c853f62a JJ |
898 | || (!POINTER_TYPE_P (TREE_TYPE (name)) |
899 | && (!INTEGRAL_TYPE_P (TREE_TYPE (name)) | |
900 | /* Don't record nonzero bits before IPA to avoid | |
901 | using too much memory. */ | |
902 | || first_pass_instance))) | |
1be38ccb RG |
903 | continue; |
904 | ||
905 | val = get_value (name); | |
906 | if (val->lattice_val != CONSTANT | |
907 | || TREE_CODE (val->value) != INTEGER_CST) | |
908 | continue; | |
909 | ||
c853f62a JJ |
910 | if (POINTER_TYPE_P (TREE_TYPE (name))) |
911 | { | |
912 | /* Trailing mask bits specify the alignment, trailing value | |
913 | bits the misalignment. */ | |
807e902e | 914 | tem = val->mask.to_uhwi (); |
c853f62a JJ |
915 | align = (tem & -tem); |
916 | if (align > 1) | |
917 | set_ptr_info_alignment (get_ptr_info (name), align, | |
918 | (TREE_INT_CST_LOW (val->value) | |
919 | & (align - 1))); | |
920 | } | |
921 | else | |
922 | { | |
807e902e KZ |
923 | unsigned int precision = TYPE_PRECISION (TREE_TYPE (val->value)); |
924 | wide_int nonzero_bits = wide_int::from (val->mask, precision, | |
925 | UNSIGNED) | val->value; | |
c853f62a JJ |
926 | nonzero_bits &= get_nonzero_bits (name); |
927 | set_nonzero_bits (name, nonzero_bits); | |
928 | } | |
1be38ccb RG |
929 | } |
930 | ||
0bca51f0 | 931 | /* Perform substitutions based on the known constant values. */ |
455e6d5b RG |
932 | something_changed = substitute_and_fold (get_constant_value, |
933 | ccp_fold_stmt, true); | |
6de9cd9a | 934 | |
0bca51f0 | 935 | free (const_val); |
ed97ddc6 | 936 | const_val = NULL; |
3253eafb | 937 | return something_changed;; |
6de9cd9a DN |
938 | } |
939 | ||
940 | ||
0bca51f0 DN |
941 | /* Compute the meet operator between *VAL1 and *VAL2. Store the result |
942 | in VAL1. | |
943 | ||
944 | any M UNDEFINED = any | |
0bca51f0 DN |
945 | any M VARYING = VARYING |
946 | Ci M Cj = Ci if (i == j) | |
947 | Ci M Cj = VARYING if (i != j) | |
106dec71 | 948 | */ |
6de9cd9a DN |
949 | |
950 | static void | |
11478306 | 951 | ccp_lattice_meet (ccp_prop_value_t *val1, ccp_prop_value_t *val2) |
6de9cd9a | 952 | { |
0bca51f0 | 953 | if (val1->lattice_val == UNDEFINED) |
6de9cd9a | 954 | { |
0bca51f0 DN |
955 | /* UNDEFINED M any = any */ |
956 | *val1 = *val2; | |
750628d8 | 957 | } |
0bca51f0 | 958 | else if (val2->lattice_val == UNDEFINED) |
195da47b | 959 | { |
0bca51f0 DN |
960 | /* any M UNDEFINED = any |
961 | Nothing to do. VAL1 already contains the value we want. */ | |
962 | ; | |
195da47b | 963 | } |
0bca51f0 DN |
964 | else if (val1->lattice_val == VARYING |
965 | || val2->lattice_val == VARYING) | |
750628d8 | 966 | { |
0bca51f0 DN |
967 | /* any M VARYING = VARYING. */ |
968 | val1->lattice_val = VARYING; | |
807e902e | 969 | val1->mask = -1; |
0bca51f0 | 970 | val1->value = NULL_TREE; |
750628d8 | 971 | } |
0b4b14ac RG |
972 | else if (val1->lattice_val == CONSTANT |
973 | && val2->lattice_val == CONSTANT | |
974 | && TREE_CODE (val1->value) == INTEGER_CST | |
975 | && TREE_CODE (val2->value) == INTEGER_CST) | |
976 | { | |
977 | /* Ci M Cj = Ci if (i == j) | |
978 | Ci M Cj = VARYING if (i != j) | |
979 | ||
980 | For INTEGER_CSTs mask unequal bits. If no equal bits remain, | |
981 | drop to varying. */ | |
807e902e KZ |
982 | val1->mask = (val1->mask | val2->mask |
983 | | (wi::to_widest (val1->value) | |
984 | ^ wi::to_widest (val2->value))); | |
985 | if (val1->mask == -1) | |
0b4b14ac RG |
986 | { |
987 | val1->lattice_val = VARYING; | |
988 | val1->value = NULL_TREE; | |
989 | } | |
990 | } | |
0bca51f0 DN |
991 | else if (val1->lattice_val == CONSTANT |
992 | && val2->lattice_val == CONSTANT | |
dce2b2f6 | 993 | && simple_cst_equal (val1->value, val2->value) == 1) |
750628d8 | 994 | { |
0bca51f0 DN |
995 | /* Ci M Cj = Ci if (i == j) |
996 | Ci M Cj = VARYING if (i != j) | |
997 | ||
0b4b14ac RG |
998 | VAL1 already contains the value we want for equivalent values. */ |
999 | } | |
1000 | else if (val1->lattice_val == CONSTANT | |
1001 | && val2->lattice_val == CONSTANT | |
1002 | && (TREE_CODE (val1->value) == ADDR_EXPR | |
1003 | || TREE_CODE (val2->value) == ADDR_EXPR)) | |
1004 | { | |
1005 | /* When not equal addresses are involved try meeting for | |
1006 | alignment. */ | |
11478306 | 1007 | ccp_prop_value_t tem = *val2; |
0b4b14ac RG |
1008 | if (TREE_CODE (val1->value) == ADDR_EXPR) |
1009 | *val1 = get_value_for_expr (val1->value, true); | |
1010 | if (TREE_CODE (val2->value) == ADDR_EXPR) | |
1011 | tem = get_value_for_expr (val2->value, true); | |
1012 | ccp_lattice_meet (val1, &tem); | |
750628d8 DN |
1013 | } |
1014 | else | |
1015 | { | |
0bca51f0 DN |
1016 | /* Any other combination is VARYING. */ |
1017 | val1->lattice_val = VARYING; | |
807e902e | 1018 | val1->mask = -1; |
0bca51f0 | 1019 | val1->value = NULL_TREE; |
750628d8 | 1020 | } |
6de9cd9a DN |
1021 | } |
1022 | ||
1023 | ||
750628d8 DN |
1024 | /* Loop through the PHI_NODE's parameters for BLOCK and compare their |
1025 | lattice values to determine PHI_NODE's lattice value. The value of a | |
0bca51f0 | 1026 | PHI node is determined calling ccp_lattice_meet with all the arguments |
750628d8 | 1027 | of the PHI node that are incoming via executable edges. */ |
6de9cd9a | 1028 | |
750628d8 | 1029 | static enum ssa_prop_result |
726a989a | 1030 | ccp_visit_phi_node (gimple phi) |
6de9cd9a | 1031 | { |
726a989a | 1032 | unsigned i; |
11478306 | 1033 | ccp_prop_value_t *old_val, new_val; |
6de9cd9a | 1034 | |
750628d8 | 1035 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6de9cd9a | 1036 | { |
750628d8 | 1037 | fprintf (dump_file, "\nVisiting PHI node: "); |
726a989a | 1038 | print_gimple_stmt (dump_file, phi, 0, dump_flags); |
6de9cd9a | 1039 | } |
6de9cd9a | 1040 | |
726a989a | 1041 | old_val = get_value (gimple_phi_result (phi)); |
750628d8 DN |
1042 | switch (old_val->lattice_val) |
1043 | { | |
1044 | case VARYING: | |
0bca51f0 | 1045 | return SSA_PROP_VARYING; |
6de9cd9a | 1046 | |
750628d8 DN |
1047 | case CONSTANT: |
1048 | new_val = *old_val; | |
1049 | break; | |
6de9cd9a | 1050 | |
750628d8 | 1051 | case UNDEFINED: |
750628d8 | 1052 | new_val.lattice_val = UNDEFINED; |
0bca51f0 | 1053 | new_val.value = NULL_TREE; |
750628d8 | 1054 | break; |
6de9cd9a | 1055 | |
750628d8 | 1056 | default: |
1e128c5f | 1057 | gcc_unreachable (); |
750628d8 | 1058 | } |
6de9cd9a | 1059 | |
726a989a | 1060 | for (i = 0; i < gimple_phi_num_args (phi); i++) |
750628d8 | 1061 | { |
0bca51f0 DN |
1062 | /* Compute the meet operator over all the PHI arguments flowing |
1063 | through executable edges. */ | |
726a989a | 1064 | edge e = gimple_phi_arg_edge (phi, i); |
6de9cd9a | 1065 | |
750628d8 DN |
1066 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1067 | { | |
1068 | fprintf (dump_file, | |
1069 | "\n Argument #%d (%d -> %d %sexecutable)\n", | |
1070 | i, e->src->index, e->dest->index, | |
1071 | (e->flags & EDGE_EXECUTABLE) ? "" : "not "); | |
1072 | } | |
1073 | ||
1074 | /* If the incoming edge is executable, Compute the meet operator for | |
1075 | the existing value of the PHI node and the current PHI argument. */ | |
1076 | if (e->flags & EDGE_EXECUTABLE) | |
1077 | { | |
726a989a | 1078 | tree arg = gimple_phi_arg (phi, i)->def; |
11478306 | 1079 | ccp_prop_value_t arg_val = get_value_for_expr (arg, false); |
6de9cd9a | 1080 | |
0bca51f0 | 1081 | ccp_lattice_meet (&new_val, &arg_val); |
6de9cd9a | 1082 | |
750628d8 DN |
1083 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1084 | { | |
1085 | fprintf (dump_file, "\t"); | |
0bca51f0 DN |
1086 | print_generic_expr (dump_file, arg, dump_flags); |
1087 | dump_lattice_value (dump_file, "\tValue: ", arg_val); | |
750628d8 DN |
1088 | fprintf (dump_file, "\n"); |
1089 | } | |
6de9cd9a | 1090 | |
750628d8 DN |
1091 | if (new_val.lattice_val == VARYING) |
1092 | break; | |
1093 | } | |
1094 | } | |
6de9cd9a DN |
1095 | |
1096 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
750628d8 DN |
1097 | { |
1098 | dump_lattice_value (dump_file, "\n PHI node value: ", new_val); | |
1099 | fprintf (dump_file, "\n\n"); | |
1100 | } | |
1101 | ||
106dec71 | 1102 | /* Make the transition to the new value. */ |
726a989a | 1103 | if (set_lattice_value (gimple_phi_result (phi), new_val)) |
750628d8 DN |
1104 | { |
1105 | if (new_val.lattice_val == VARYING) | |
1106 | return SSA_PROP_VARYING; | |
1107 | else | |
1108 | return SSA_PROP_INTERESTING; | |
1109 | } | |
1110 | else | |
1111 | return SSA_PROP_NOT_INTERESTING; | |
6de9cd9a DN |
1112 | } |
1113 | ||
84d77ca6 | 1114 | /* Return the constant value for OP or OP otherwise. */ |
0354c0c7 BS |
1115 | |
1116 | static tree | |
84d77ca6 | 1117 | valueize_op (tree op) |
0354c0c7 | 1118 | { |
0354c0c7 BS |
1119 | if (TREE_CODE (op) == SSA_NAME) |
1120 | { | |
84d77ca6 RG |
1121 | tree tem = get_constant_value (op); |
1122 | if (tem) | |
1123 | return tem; | |
0354c0c7 BS |
1124 | } |
1125 | return op; | |
1126 | } | |
1127 | ||
750628d8 DN |
1128 | /* CCP specific front-end to the non-destructive constant folding |
1129 | routines. | |
6de9cd9a DN |
1130 | |
1131 | Attempt to simplify the RHS of STMT knowing that one or more | |
1132 | operands are constants. | |
1133 | ||
1134 | If simplification is possible, return the simplified RHS, | |
726a989a | 1135 | otherwise return the original RHS or NULL_TREE. */ |
6de9cd9a DN |
1136 | |
1137 | static tree | |
726a989a | 1138 | ccp_fold (gimple stmt) |
6de9cd9a | 1139 | { |
db3927fb | 1140 | location_t loc = gimple_location (stmt); |
726a989a | 1141 | switch (gimple_code (stmt)) |
0bca51f0 | 1142 | { |
726a989a RB |
1143 | case GIMPLE_COND: |
1144 | { | |
1145 | /* Handle comparison operators that can appear in GIMPLE form. */ | |
84d77ca6 RG |
1146 | tree op0 = valueize_op (gimple_cond_lhs (stmt)); |
1147 | tree op1 = valueize_op (gimple_cond_rhs (stmt)); | |
726a989a | 1148 | enum tree_code code = gimple_cond_code (stmt); |
db3927fb | 1149 | return fold_binary_loc (loc, code, boolean_type_node, op0, op1); |
726a989a | 1150 | } |
6de9cd9a | 1151 | |
726a989a RB |
1152 | case GIMPLE_SWITCH: |
1153 | { | |
84d77ca6 RG |
1154 | /* Return the constant switch index. */ |
1155 | return valueize_op (gimple_switch_index (stmt)); | |
726a989a | 1156 | } |
00d382a8 | 1157 | |
cfef45c8 RG |
1158 | case GIMPLE_ASSIGN: |
1159 | case GIMPLE_CALL: | |
1160 | return gimple_fold_stmt_to_constant_1 (stmt, valueize_op); | |
87e1e42b | 1161 | |
ae3df618 | 1162 | default: |
cfef45c8 | 1163 | gcc_unreachable (); |
ae3df618 | 1164 | } |
ae3df618 | 1165 | } |
726a989a | 1166 | |
0b4b14ac RG |
1167 | /* Apply the operation CODE in type TYPE to the value, mask pair |
1168 | RVAL and RMASK representing a value of type RTYPE and set | |
1169 | the value, mask pair *VAL and *MASK to the result. */ | |
1170 | ||
1171 | static void | |
1172 | bit_value_unop_1 (enum tree_code code, tree type, | |
807e902e KZ |
1173 | widest_int *val, widest_int *mask, |
1174 | tree rtype, const widest_int &rval, const widest_int &rmask) | |
0b4b14ac RG |
1175 | { |
1176 | switch (code) | |
1177 | { | |
1178 | case BIT_NOT_EXPR: | |
1179 | *mask = rmask; | |
27bcd47c | 1180 | *val = ~rval; |
0b4b14ac RG |
1181 | break; |
1182 | ||
1183 | case NEGATE_EXPR: | |
1184 | { | |
807e902e | 1185 | widest_int temv, temm; |
0b4b14ac RG |
1186 | /* Return ~rval + 1. */ |
1187 | bit_value_unop_1 (BIT_NOT_EXPR, type, &temv, &temm, type, rval, rmask); | |
1188 | bit_value_binop_1 (PLUS_EXPR, type, val, mask, | |
807e902e | 1189 | type, temv, temm, type, 1, 0); |
0b4b14ac RG |
1190 | break; |
1191 | } | |
1192 | ||
1193 | CASE_CONVERT: | |
1194 | { | |
807e902e | 1195 | signop sgn; |
0b4b14ac RG |
1196 | |
1197 | /* First extend mask and value according to the original type. */ | |
807e902e KZ |
1198 | sgn = TYPE_SIGN (rtype); |
1199 | *mask = wi::ext (rmask, TYPE_PRECISION (rtype), sgn); | |
1200 | *val = wi::ext (rval, TYPE_PRECISION (rtype), sgn); | |
0b4b14ac RG |
1201 | |
1202 | /* Then extend mask and value according to the target type. */ | |
807e902e KZ |
1203 | sgn = TYPE_SIGN (type); |
1204 | *mask = wi::ext (*mask, TYPE_PRECISION (type), sgn); | |
1205 | *val = wi::ext (*val, TYPE_PRECISION (type), sgn); | |
0b4b14ac RG |
1206 | break; |
1207 | } | |
1208 | ||
1209 | default: | |
807e902e | 1210 | *mask = -1; |
0b4b14ac RG |
1211 | break; |
1212 | } | |
1213 | } | |
1214 | ||
1215 | /* Apply the operation CODE in type TYPE to the value, mask pairs | |
1216 | R1VAL, R1MASK and R2VAL, R2MASK representing a values of type R1TYPE | |
1217 | and R2TYPE and set the value, mask pair *VAL and *MASK to the result. */ | |
1218 | ||
1219 | static void | |
1220 | bit_value_binop_1 (enum tree_code code, tree type, | |
807e902e KZ |
1221 | widest_int *val, widest_int *mask, |
1222 | tree r1type, const widest_int &r1val, | |
1223 | const widest_int &r1mask, tree r2type, | |
1224 | const widest_int &r2val, const widest_int &r2mask) | |
0b4b14ac | 1225 | { |
807e902e KZ |
1226 | signop sgn = TYPE_SIGN (type); |
1227 | int width = TYPE_PRECISION (type); | |
1228 | bool swap_p = false; | |
1229 | ||
1230 | /* Assume we'll get a constant result. Use an initial non varying | |
1231 | value, we fall back to varying in the end if necessary. */ | |
1232 | *mask = -1; | |
1233 | ||
0b4b14ac RG |
1234 | switch (code) |
1235 | { | |
1236 | case BIT_AND_EXPR: | |
1237 | /* The mask is constant where there is a known not | |
1238 | set bit, (m1 | m2) & ((v1 | m1) & (v2 | m2)) */ | |
27bcd47c LC |
1239 | *mask = (r1mask | r2mask) & (r1val | r1mask) & (r2val | r2mask); |
1240 | *val = r1val & r2val; | |
0b4b14ac RG |
1241 | break; |
1242 | ||
1243 | case BIT_IOR_EXPR: | |
1244 | /* The mask is constant where there is a known | |
1245 | set bit, (m1 | m2) & ~((v1 & ~m1) | (v2 & ~m2)). */ | |
27bcd47c LC |
1246 | *mask = (r1mask | r2mask) |
1247 | .and_not (r1val.and_not (r1mask) | r2val.and_not (r2mask)); | |
1248 | *val = r1val | r2val; | |
0b4b14ac RG |
1249 | break; |
1250 | ||
1251 | case BIT_XOR_EXPR: | |
1252 | /* m1 | m2 */ | |
27bcd47c LC |
1253 | *mask = r1mask | r2mask; |
1254 | *val = r1val ^ r2val; | |
0b4b14ac RG |
1255 | break; |
1256 | ||
1257 | case LROTATE_EXPR: | |
1258 | case RROTATE_EXPR: | |
807e902e | 1259 | if (r2mask == 0) |
0b4b14ac | 1260 | { |
807e902e KZ |
1261 | widest_int shift = r2val; |
1262 | if (shift == 0) | |
1263 | { | |
1264 | *mask = r1mask; | |
1265 | *val = r1val; | |
1266 | } | |
1267 | else | |
1268 | { | |
1269 | if (wi::neg_p (shift)) | |
1270 | { | |
1271 | shift = -shift; | |
1272 | if (code == RROTATE_EXPR) | |
1273 | code = LROTATE_EXPR; | |
1274 | else | |
1275 | code = RROTATE_EXPR; | |
1276 | } | |
1277 | if (code == RROTATE_EXPR) | |
1278 | { | |
1279 | *mask = wi::rrotate (r1mask, shift, width); | |
1280 | *val = wi::rrotate (r1val, shift, width); | |
1281 | } | |
1282 | else | |
1283 | { | |
1284 | *mask = wi::lrotate (r1mask, shift, width); | |
1285 | *val = wi::lrotate (r1val, shift, width); | |
1286 | } | |
1287 | } | |
0b4b14ac RG |
1288 | } |
1289 | break; | |
1290 | ||
1291 | case LSHIFT_EXPR: | |
1292 | case RSHIFT_EXPR: | |
1293 | /* ??? We can handle partially known shift counts if we know | |
1294 | its sign. That way we can tell that (x << (y | 8)) & 255 | |
1295 | is zero. */ | |
807e902e | 1296 | if (r2mask == 0) |
0b4b14ac | 1297 | { |
807e902e KZ |
1298 | widest_int shift = r2val; |
1299 | if (shift == 0) | |
0b4b14ac | 1300 | { |
807e902e KZ |
1301 | *mask = r1mask; |
1302 | *val = r1val; | |
0b4b14ac RG |
1303 | } |
1304 | else | |
1305 | { | |
807e902e KZ |
1306 | if (wi::neg_p (shift)) |
1307 | { | |
1308 | shift = -shift; | |
1309 | if (code == RSHIFT_EXPR) | |
1310 | code = LSHIFT_EXPR; | |
1311 | else | |
1312 | code = RSHIFT_EXPR; | |
1313 | } | |
1314 | if (code == RSHIFT_EXPR) | |
1315 | { | |
1316 | *mask = wi::rshift (wi::ext (r1mask, width, sgn), shift, sgn); | |
1317 | *val = wi::rshift (wi::ext (r1val, width, sgn), shift, sgn); | |
1318 | } | |
1319 | else | |
1320 | { | |
1321 | *mask = wi::ext (wi::lshift (r1mask, shift), width, sgn); | |
1322 | *val = wi::ext (wi::lshift (r1val, shift), width, sgn); | |
1323 | } | |
0b4b14ac RG |
1324 | } |
1325 | } | |
1326 | break; | |
1327 | ||
1328 | case PLUS_EXPR: | |
1329 | case POINTER_PLUS_EXPR: | |
1330 | { | |
0b4b14ac RG |
1331 | /* Do the addition with unknown bits set to zero, to give carry-ins of |
1332 | zero wherever possible. */ | |
807e902e KZ |
1333 | widest_int lo = r1val.and_not (r1mask) + r2val.and_not (r2mask); |
1334 | lo = wi::ext (lo, width, sgn); | |
0b4b14ac RG |
1335 | /* Do the addition with unknown bits set to one, to give carry-ins of |
1336 | one wherever possible. */ | |
807e902e KZ |
1337 | widest_int hi = (r1val | r1mask) + (r2val | r2mask); |
1338 | hi = wi::ext (hi, width, sgn); | |
0b4b14ac RG |
1339 | /* Each bit in the result is known if (a) the corresponding bits in |
1340 | both inputs are known, and (b) the carry-in to that bit position | |
1341 | is known. We can check condition (b) by seeing if we got the same | |
1342 | result with minimised carries as with maximised carries. */ | |
27bcd47c | 1343 | *mask = r1mask | r2mask | (lo ^ hi); |
807e902e | 1344 | *mask = wi::ext (*mask, width, sgn); |
0b4b14ac RG |
1345 | /* It shouldn't matter whether we choose lo or hi here. */ |
1346 | *val = lo; | |
1347 | break; | |
1348 | } | |
1349 | ||
1350 | case MINUS_EXPR: | |
1351 | { | |
807e902e | 1352 | widest_int temv, temm; |
0b4b14ac RG |
1353 | bit_value_unop_1 (NEGATE_EXPR, r2type, &temv, &temm, |
1354 | r2type, r2val, r2mask); | |
1355 | bit_value_binop_1 (PLUS_EXPR, type, val, mask, | |
1356 | r1type, r1val, r1mask, | |
1357 | r2type, temv, temm); | |
1358 | break; | |
1359 | } | |
1360 | ||
1361 | case MULT_EXPR: | |
1362 | { | |
1363 | /* Just track trailing zeros in both operands and transfer | |
1364 | them to the other. */ | |
807e902e KZ |
1365 | int r1tz = wi::ctz (r1val | r1mask); |
1366 | int r2tz = wi::ctz (r2val | r2mask); | |
1367 | if (r1tz + r2tz >= width) | |
0b4b14ac | 1368 | { |
807e902e KZ |
1369 | *mask = 0; |
1370 | *val = 0; | |
0b4b14ac RG |
1371 | } |
1372 | else if (r1tz + r2tz > 0) | |
1373 | { | |
807e902e KZ |
1374 | *mask = wi::ext (wi::mask <widest_int> (r1tz + r2tz, true), |
1375 | width, sgn); | |
1376 | *val = 0; | |
0b4b14ac RG |
1377 | } |
1378 | break; | |
1379 | } | |
1380 | ||
1381 | case EQ_EXPR: | |
1382 | case NE_EXPR: | |
1383 | { | |
807e902e | 1384 | widest_int m = r1mask | r2mask; |
27bcd47c | 1385 | if (r1val.and_not (m) != r2val.and_not (m)) |
0b4b14ac | 1386 | { |
807e902e KZ |
1387 | *mask = 0; |
1388 | *val = ((code == EQ_EXPR) ? 0 : 1); | |
0b4b14ac RG |
1389 | } |
1390 | else | |
1391 | { | |
1392 | /* We know the result of a comparison is always one or zero. */ | |
807e902e KZ |
1393 | *mask = 1; |
1394 | *val = 0; | |
0b4b14ac RG |
1395 | } |
1396 | break; | |
1397 | } | |
1398 | ||
1399 | case GE_EXPR: | |
1400 | case GT_EXPR: | |
807e902e KZ |
1401 | swap_p = true; |
1402 | code = swap_tree_comparison (code); | |
1403 | /* Fall through. */ | |
0b4b14ac RG |
1404 | case LT_EXPR: |
1405 | case LE_EXPR: | |
1406 | { | |
1407 | int minmax, maxmin; | |
807e902e KZ |
1408 | |
1409 | const widest_int &o1val = swap_p ? r2val : r1val; | |
1410 | const widest_int &o1mask = swap_p ? r2mask : r1mask; | |
1411 | const widest_int &o2val = swap_p ? r1val : r2val; | |
1412 | const widest_int &o2mask = swap_p ? r1mask : r2mask; | |
1413 | ||
0b4b14ac | 1414 | /* If the most significant bits are not known we know nothing. */ |
807e902e | 1415 | if (wi::neg_p (o1mask) || wi::neg_p (o2mask)) |
0b4b14ac RG |
1416 | break; |
1417 | ||
0425d6f5 | 1418 | /* For comparisons the signedness is in the comparison operands. */ |
807e902e | 1419 | sgn = TYPE_SIGN (r1type); |
0425d6f5 | 1420 | |
0b4b14ac RG |
1421 | /* If we know the most significant bits we know the values |
1422 | value ranges by means of treating varying bits as zero | |
1423 | or one. Do a cross comparison of the max/min pairs. */ | |
807e902e KZ |
1424 | maxmin = wi::cmp (o1val | o1mask, o2val.and_not (o2mask), sgn); |
1425 | minmax = wi::cmp (o1val.and_not (o1mask), o2val | o2mask, sgn); | |
1426 | if (maxmin < 0) /* o1 is less than o2. */ | |
0b4b14ac | 1427 | { |
807e902e KZ |
1428 | *mask = 0; |
1429 | *val = 1; | |
0b4b14ac | 1430 | } |
807e902e | 1431 | else if (minmax > 0) /* o1 is not less or equal to o2. */ |
0b4b14ac | 1432 | { |
807e902e KZ |
1433 | *mask = 0; |
1434 | *val = 0; | |
0b4b14ac | 1435 | } |
807e902e | 1436 | else if (maxmin == minmax) /* o1 and o2 are equal. */ |
0b4b14ac RG |
1437 | { |
1438 | /* This probably should never happen as we'd have | |
1439 | folded the thing during fully constant value folding. */ | |
807e902e KZ |
1440 | *mask = 0; |
1441 | *val = (code == LE_EXPR ? 1 : 0); | |
0b4b14ac RG |
1442 | } |
1443 | else | |
1444 | { | |
1445 | /* We know the result of a comparison is always one or zero. */ | |
807e902e KZ |
1446 | *mask = 1; |
1447 | *val = 0; | |
0b4b14ac RG |
1448 | } |
1449 | break; | |
1450 | } | |
1451 | ||
1452 | default:; | |
1453 | } | |
1454 | } | |
1455 | ||
1456 | /* Return the propagation value when applying the operation CODE to | |
1457 | the value RHS yielding type TYPE. */ | |
1458 | ||
11478306 | 1459 | static ccp_prop_value_t |
0b4b14ac RG |
1460 | bit_value_unop (enum tree_code code, tree type, tree rhs) |
1461 | { | |
11478306 | 1462 | ccp_prop_value_t rval = get_value_for_expr (rhs, true); |
807e902e | 1463 | widest_int value, mask; |
11478306 | 1464 | ccp_prop_value_t val; |
6ad024b4 RG |
1465 | |
1466 | if (rval.lattice_val == UNDEFINED) | |
1467 | return rval; | |
1468 | ||
0b4b14ac RG |
1469 | gcc_assert ((rval.lattice_val == CONSTANT |
1470 | && TREE_CODE (rval.value) == INTEGER_CST) | |
807e902e | 1471 | || rval.mask == -1); |
0b4b14ac | 1472 | bit_value_unop_1 (code, type, &value, &mask, |
807e902e KZ |
1473 | TREE_TYPE (rhs), value_to_wide_int (rval), rval.mask); |
1474 | if (mask != -1) | |
0b4b14ac RG |
1475 | { |
1476 | val.lattice_val = CONSTANT; | |
1477 | val.mask = mask; | |
1478 | /* ??? Delay building trees here. */ | |
807e902e | 1479 | val.value = wide_int_to_tree (type, value); |
0b4b14ac RG |
1480 | } |
1481 | else | |
1482 | { | |
1483 | val.lattice_val = VARYING; | |
1484 | val.value = NULL_TREE; | |
807e902e | 1485 | val.mask = -1; |
0b4b14ac RG |
1486 | } |
1487 | return val; | |
1488 | } | |
1489 | ||
1490 | /* Return the propagation value when applying the operation CODE to | |
1491 | the values RHS1 and RHS2 yielding type TYPE. */ | |
1492 | ||
11478306 | 1493 | static ccp_prop_value_t |
0b4b14ac RG |
1494 | bit_value_binop (enum tree_code code, tree type, tree rhs1, tree rhs2) |
1495 | { | |
11478306 JH |
1496 | ccp_prop_value_t r1val = get_value_for_expr (rhs1, true); |
1497 | ccp_prop_value_t r2val = get_value_for_expr (rhs2, true); | |
807e902e | 1498 | widest_int value, mask; |
11478306 | 1499 | ccp_prop_value_t val; |
6ad024b4 RG |
1500 | |
1501 | if (r1val.lattice_val == UNDEFINED | |
1502 | || r2val.lattice_val == UNDEFINED) | |
1503 | { | |
1504 | val.lattice_val = VARYING; | |
1505 | val.value = NULL_TREE; | |
807e902e | 1506 | val.mask = -1; |
6ad024b4 RG |
1507 | return val; |
1508 | } | |
1509 | ||
0b4b14ac RG |
1510 | gcc_assert ((r1val.lattice_val == CONSTANT |
1511 | && TREE_CODE (r1val.value) == INTEGER_CST) | |
807e902e | 1512 | || r1val.mask == -1); |
0b4b14ac RG |
1513 | gcc_assert ((r2val.lattice_val == CONSTANT |
1514 | && TREE_CODE (r2val.value) == INTEGER_CST) | |
807e902e | 1515 | || r2val.mask == -1); |
0b4b14ac | 1516 | bit_value_binop_1 (code, type, &value, &mask, |
807e902e KZ |
1517 | TREE_TYPE (rhs1), value_to_wide_int (r1val), r1val.mask, |
1518 | TREE_TYPE (rhs2), value_to_wide_int (r2val), r2val.mask); | |
1519 | if (mask != -1) | |
0b4b14ac RG |
1520 | { |
1521 | val.lattice_val = CONSTANT; | |
1522 | val.mask = mask; | |
1523 | /* ??? Delay building trees here. */ | |
807e902e | 1524 | val.value = wide_int_to_tree (type, value); |
0b4b14ac RG |
1525 | } |
1526 | else | |
1527 | { | |
1528 | val.lattice_val = VARYING; | |
1529 | val.value = NULL_TREE; | |
807e902e | 1530 | val.mask = -1; |
0b4b14ac RG |
1531 | } |
1532 | return val; | |
1533 | } | |
1534 | ||
8fcbce72 JJ |
1535 | /* Return the propagation value for __builtin_assume_aligned |
1536 | and functions with assume_aligned or alloc_aligned attribute. | |
1537 | For __builtin_assume_aligned, ATTR is NULL_TREE, | |
1538 | for assume_aligned attribute ATTR is non-NULL and ALLOC_ALIGNED | |
1539 | is false, for alloc_aligned attribute ATTR is non-NULL and | |
1540 | ALLOC_ALIGNED is true. */ | |
45d439ac | 1541 | |
11478306 JH |
1542 | static ccp_prop_value_t |
1543 | bit_value_assume_aligned (gimple stmt, tree attr, ccp_prop_value_t ptrval, | |
8fcbce72 | 1544 | bool alloc_aligned) |
45d439ac | 1545 | { |
8fcbce72 | 1546 | tree align, misalign = NULL_TREE, type; |
45d439ac | 1547 | unsigned HOST_WIDE_INT aligni, misaligni = 0; |
11478306 | 1548 | ccp_prop_value_t alignval; |
807e902e | 1549 | widest_int value, mask; |
11478306 | 1550 | ccp_prop_value_t val; |
8fcbce72 JJ |
1551 | |
1552 | if (attr == NULL_TREE) | |
1553 | { | |
1554 | tree ptr = gimple_call_arg (stmt, 0); | |
1555 | type = TREE_TYPE (ptr); | |
1556 | ptrval = get_value_for_expr (ptr, true); | |
1557 | } | |
1558 | else | |
1559 | { | |
1560 | tree lhs = gimple_call_lhs (stmt); | |
1561 | type = TREE_TYPE (lhs); | |
1562 | } | |
1563 | ||
45d439ac JJ |
1564 | if (ptrval.lattice_val == UNDEFINED) |
1565 | return ptrval; | |
1566 | gcc_assert ((ptrval.lattice_val == CONSTANT | |
1567 | && TREE_CODE (ptrval.value) == INTEGER_CST) | |
807e902e | 1568 | || ptrval.mask == -1); |
8fcbce72 | 1569 | if (attr == NULL_TREE) |
45d439ac | 1570 | { |
8fcbce72 JJ |
1571 | /* Get aligni and misaligni from __builtin_assume_aligned. */ |
1572 | align = gimple_call_arg (stmt, 1); | |
1573 | if (!tree_fits_uhwi_p (align)) | |
45d439ac | 1574 | return ptrval; |
8fcbce72 JJ |
1575 | aligni = tree_to_uhwi (align); |
1576 | if (gimple_call_num_args (stmt) > 2) | |
1577 | { | |
1578 | misalign = gimple_call_arg (stmt, 2); | |
1579 | if (!tree_fits_uhwi_p (misalign)) | |
1580 | return ptrval; | |
1581 | misaligni = tree_to_uhwi (misalign); | |
1582 | } | |
1583 | } | |
1584 | else | |
1585 | { | |
1586 | /* Get aligni and misaligni from assume_aligned or | |
1587 | alloc_align attributes. */ | |
1588 | if (TREE_VALUE (attr) == NULL_TREE) | |
1589 | return ptrval; | |
1590 | attr = TREE_VALUE (attr); | |
1591 | align = TREE_VALUE (attr); | |
1592 | if (!tree_fits_uhwi_p (align)) | |
45d439ac | 1593 | return ptrval; |
8fcbce72 JJ |
1594 | aligni = tree_to_uhwi (align); |
1595 | if (alloc_aligned) | |
1596 | { | |
1597 | if (aligni == 0 || aligni > gimple_call_num_args (stmt)) | |
1598 | return ptrval; | |
1599 | align = gimple_call_arg (stmt, aligni - 1); | |
1600 | if (!tree_fits_uhwi_p (align)) | |
1601 | return ptrval; | |
1602 | aligni = tree_to_uhwi (align); | |
1603 | } | |
1604 | else if (TREE_CHAIN (attr) && TREE_VALUE (TREE_CHAIN (attr))) | |
1605 | { | |
1606 | misalign = TREE_VALUE (TREE_CHAIN (attr)); | |
1607 | if (!tree_fits_uhwi_p (misalign)) | |
1608 | return ptrval; | |
1609 | misaligni = tree_to_uhwi (misalign); | |
1610 | } | |
45d439ac | 1611 | } |
8fcbce72 JJ |
1612 | if (aligni <= 1 || (aligni & (aligni - 1)) != 0 || misaligni >= aligni) |
1613 | return ptrval; | |
1614 | ||
45d439ac JJ |
1615 | align = build_int_cst_type (type, -aligni); |
1616 | alignval = get_value_for_expr (align, true); | |
1617 | bit_value_binop_1 (BIT_AND_EXPR, type, &value, &mask, | |
807e902e KZ |
1618 | type, value_to_wide_int (ptrval), ptrval.mask, |
1619 | type, value_to_wide_int (alignval), alignval.mask); | |
1620 | if (mask != -1) | |
45d439ac JJ |
1621 | { |
1622 | val.lattice_val = CONSTANT; | |
1623 | val.mask = mask; | |
807e902e KZ |
1624 | gcc_assert ((mask.to_uhwi () & (aligni - 1)) == 0); |
1625 | gcc_assert ((value.to_uhwi () & (aligni - 1)) == 0); | |
1626 | value |= misaligni; | |
45d439ac | 1627 | /* ??? Delay building trees here. */ |
807e902e | 1628 | val.value = wide_int_to_tree (type, value); |
45d439ac JJ |
1629 | } |
1630 | else | |
1631 | { | |
1632 | val.lattice_val = VARYING; | |
1633 | val.value = NULL_TREE; | |
807e902e | 1634 | val.mask = -1; |
45d439ac JJ |
1635 | } |
1636 | return val; | |
1637 | } | |
1638 | ||
726a989a RB |
1639 | /* Evaluate statement STMT. |
1640 | Valid only for assignments, calls, conditionals, and switches. */ | |
6de9cd9a | 1641 | |
11478306 | 1642 | static ccp_prop_value_t |
726a989a | 1643 | evaluate_stmt (gimple stmt) |
6de9cd9a | 1644 | { |
11478306 | 1645 | ccp_prop_value_t val; |
faaf1436 | 1646 | tree simplified = NULL_TREE; |
0bca51f0 | 1647 | ccp_lattice_t likelyvalue = likely_value (stmt); |
0b4b14ac | 1648 | bool is_constant = false; |
13e49da9 | 1649 | unsigned int align; |
0bca51f0 | 1650 | |
0b4b14ac RG |
1651 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1652 | { | |
1653 | fprintf (dump_file, "which is likely "); | |
1654 | switch (likelyvalue) | |
1655 | { | |
1656 | case CONSTANT: | |
1657 | fprintf (dump_file, "CONSTANT"); | |
1658 | break; | |
1659 | case UNDEFINED: | |
1660 | fprintf (dump_file, "UNDEFINED"); | |
1661 | break; | |
1662 | case VARYING: | |
1663 | fprintf (dump_file, "VARYING"); | |
1664 | break; | |
1665 | default:; | |
1666 | } | |
1667 | fprintf (dump_file, "\n"); | |
1668 | } | |
6ac01510 | 1669 | |
6de9cd9a DN |
1670 | /* If the statement is likely to have a CONSTANT result, then try |
1671 | to fold the statement to determine the constant value. */ | |
726a989a RB |
1672 | /* FIXME. This is the only place that we call ccp_fold. |
1673 | Since likely_value never returns CONSTANT for calls, we will | |
1674 | not attempt to fold them, including builtins that may profit. */ | |
6de9cd9a | 1675 | if (likelyvalue == CONSTANT) |
0b4b14ac RG |
1676 | { |
1677 | fold_defer_overflow_warnings (); | |
1678 | simplified = ccp_fold (stmt); | |
1679 | is_constant = simplified && is_gimple_min_invariant (simplified); | |
1680 | fold_undefer_overflow_warnings (is_constant, stmt, 0); | |
1681 | if (is_constant) | |
1682 | { | |
1683 | /* The statement produced a constant value. */ | |
1684 | val.lattice_val = CONSTANT; | |
1685 | val.value = simplified; | |
807e902e | 1686 | val.mask = 0; |
0b4b14ac RG |
1687 | } |
1688 | } | |
6de9cd9a DN |
1689 | /* If the statement is likely to have a VARYING result, then do not |
1690 | bother folding the statement. */ | |
87e1e42b | 1691 | else if (likelyvalue == VARYING) |
726a989a | 1692 | { |
e0c68ce9 | 1693 | enum gimple_code code = gimple_code (stmt); |
726a989a RB |
1694 | if (code == GIMPLE_ASSIGN) |
1695 | { | |
1696 | enum tree_code subcode = gimple_assign_rhs_code (stmt); | |
b8698a0f | 1697 | |
726a989a RB |
1698 | /* Other cases cannot satisfy is_gimple_min_invariant |
1699 | without folding. */ | |
1700 | if (get_gimple_rhs_class (subcode) == GIMPLE_SINGLE_RHS) | |
1701 | simplified = gimple_assign_rhs1 (stmt); | |
1702 | } | |
1703 | else if (code == GIMPLE_SWITCH) | |
1704 | simplified = gimple_switch_index (stmt); | |
1705 | else | |
44e10129 MM |
1706 | /* These cannot satisfy is_gimple_min_invariant without folding. */ |
1707 | gcc_assert (code == GIMPLE_CALL || code == GIMPLE_COND); | |
0b4b14ac RG |
1708 | is_constant = simplified && is_gimple_min_invariant (simplified); |
1709 | if (is_constant) | |
1710 | { | |
1711 | /* The statement produced a constant value. */ | |
1712 | val.lattice_val = CONSTANT; | |
1713 | val.value = simplified; | |
807e902e | 1714 | val.mask = 0; |
0b4b14ac | 1715 | } |
726a989a | 1716 | } |
6de9cd9a | 1717 | |
0b4b14ac RG |
1718 | /* Resort to simplification for bitwise tracking. */ |
1719 | if (flag_tree_bit_ccp | |
36dc1a88 | 1720 | && (likelyvalue == CONSTANT || is_gimple_call (stmt)) |
0b4b14ac | 1721 | && !is_constant) |
00d382a8 | 1722 | { |
0b4b14ac RG |
1723 | enum gimple_code code = gimple_code (stmt); |
1724 | val.lattice_val = VARYING; | |
1725 | val.value = NULL_TREE; | |
807e902e | 1726 | val.mask = -1; |
0b4b14ac | 1727 | if (code == GIMPLE_ASSIGN) |
00d382a8 | 1728 | { |
0b4b14ac RG |
1729 | enum tree_code subcode = gimple_assign_rhs_code (stmt); |
1730 | tree rhs1 = gimple_assign_rhs1 (stmt); | |
1731 | switch (get_gimple_rhs_class (subcode)) | |
1732 | { | |
1733 | case GIMPLE_SINGLE_RHS: | |
1734 | if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
1735 | || POINTER_TYPE_P (TREE_TYPE (rhs1))) | |
1736 | val = get_value_for_expr (rhs1, true); | |
1737 | break; | |
1738 | ||
1739 | case GIMPLE_UNARY_RHS: | |
1740 | if ((INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
1741 | || POINTER_TYPE_P (TREE_TYPE (rhs1))) | |
1742 | && (INTEGRAL_TYPE_P (gimple_expr_type (stmt)) | |
1743 | || POINTER_TYPE_P (gimple_expr_type (stmt)))) | |
1744 | val = bit_value_unop (subcode, gimple_expr_type (stmt), rhs1); | |
1745 | break; | |
1746 | ||
1747 | case GIMPLE_BINARY_RHS: | |
1748 | if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
1749 | || POINTER_TYPE_P (TREE_TYPE (rhs1))) | |
1750 | { | |
4e996296 | 1751 | tree lhs = gimple_assign_lhs (stmt); |
0b4b14ac RG |
1752 | tree rhs2 = gimple_assign_rhs2 (stmt); |
1753 | val = bit_value_binop (subcode, | |
4e996296 | 1754 | TREE_TYPE (lhs), rhs1, rhs2); |
0b4b14ac RG |
1755 | } |
1756 | break; | |
1757 | ||
1758 | default:; | |
1759 | } | |
00d382a8 | 1760 | } |
0b4b14ac RG |
1761 | else if (code == GIMPLE_COND) |
1762 | { | |
1763 | enum tree_code code = gimple_cond_code (stmt); | |
1764 | tree rhs1 = gimple_cond_lhs (stmt); | |
1765 | tree rhs2 = gimple_cond_rhs (stmt); | |
1766 | if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
1767 | || POINTER_TYPE_P (TREE_TYPE (rhs1))) | |
1768 | val = bit_value_binop (code, TREE_TYPE (rhs1), rhs1, rhs2); | |
1769 | } | |
3138f224 | 1770 | else if (gimple_call_builtin_p (stmt, BUILT_IN_NORMAL)) |
1be38ccb | 1771 | { |
3138f224 | 1772 | tree fndecl = gimple_call_fndecl (stmt); |
1be38ccb RG |
1773 | switch (DECL_FUNCTION_CODE (fndecl)) |
1774 | { | |
1775 | case BUILT_IN_MALLOC: | |
1776 | case BUILT_IN_REALLOC: | |
1777 | case BUILT_IN_CALLOC: | |
36dc1a88 JJ |
1778 | case BUILT_IN_STRDUP: |
1779 | case BUILT_IN_STRNDUP: | |
1be38ccb RG |
1780 | val.lattice_val = CONSTANT; |
1781 | val.value = build_int_cst (TREE_TYPE (gimple_get_lhs (stmt)), 0); | |
807e902e KZ |
1782 | val.mask = ~((HOST_WIDE_INT) MALLOC_ABI_ALIGNMENT |
1783 | / BITS_PER_UNIT - 1); | |
1be38ccb RG |
1784 | break; |
1785 | ||
1786 | case BUILT_IN_ALLOCA: | |
13e49da9 TV |
1787 | case BUILT_IN_ALLOCA_WITH_ALIGN: |
1788 | align = (DECL_FUNCTION_CODE (fndecl) == BUILT_IN_ALLOCA_WITH_ALIGN | |
1789 | ? TREE_INT_CST_LOW (gimple_call_arg (stmt, 1)) | |
1790 | : BIGGEST_ALIGNMENT); | |
1be38ccb RG |
1791 | val.lattice_val = CONSTANT; |
1792 | val.value = build_int_cst (TREE_TYPE (gimple_get_lhs (stmt)), 0); | |
807e902e | 1793 | val.mask = ~((HOST_WIDE_INT) align / BITS_PER_UNIT - 1); |
1be38ccb RG |
1794 | break; |
1795 | ||
36dc1a88 JJ |
1796 | /* These builtins return their first argument, unmodified. */ |
1797 | case BUILT_IN_MEMCPY: | |
1798 | case BUILT_IN_MEMMOVE: | |
1799 | case BUILT_IN_MEMSET: | |
1800 | case BUILT_IN_STRCPY: | |
1801 | case BUILT_IN_STRNCPY: | |
1802 | case BUILT_IN_MEMCPY_CHK: | |
1803 | case BUILT_IN_MEMMOVE_CHK: | |
1804 | case BUILT_IN_MEMSET_CHK: | |
1805 | case BUILT_IN_STRCPY_CHK: | |
1806 | case BUILT_IN_STRNCPY_CHK: | |
1807 | val = get_value_for_expr (gimple_call_arg (stmt, 0), true); | |
1808 | break; | |
1809 | ||
45d439ac | 1810 | case BUILT_IN_ASSUME_ALIGNED: |
8fcbce72 | 1811 | val = bit_value_assume_aligned (stmt, NULL_TREE, val, false); |
45d439ac JJ |
1812 | break; |
1813 | ||
22869a37 RB |
1814 | case BUILT_IN_ALIGNED_ALLOC: |
1815 | { | |
1816 | tree align = get_constant_value (gimple_call_arg (stmt, 0)); | |
1817 | if (align | |
1818 | && tree_fits_uhwi_p (align)) | |
1819 | { | |
1820 | unsigned HOST_WIDE_INT aligni = tree_to_uhwi (align); | |
1821 | if (aligni > 1 | |
1822 | /* align must be power-of-two */ | |
1823 | && (aligni & (aligni - 1)) == 0) | |
1824 | { | |
1825 | val.lattice_val = CONSTANT; | |
1826 | val.value = build_int_cst (ptr_type_node, 0); | |
807e902e | 1827 | val.mask = -aligni; |
22869a37 RB |
1828 | } |
1829 | } | |
1830 | break; | |
1831 | } | |
1832 | ||
1be38ccb RG |
1833 | default:; |
1834 | } | |
1835 | } | |
8fcbce72 JJ |
1836 | if (is_gimple_call (stmt) && gimple_call_lhs (stmt)) |
1837 | { | |
1838 | tree fntype = gimple_call_fntype (stmt); | |
1839 | if (fntype) | |
1840 | { | |
1841 | tree attrs = lookup_attribute ("assume_aligned", | |
1842 | TYPE_ATTRIBUTES (fntype)); | |
1843 | if (attrs) | |
1844 | val = bit_value_assume_aligned (stmt, attrs, val, false); | |
1845 | attrs = lookup_attribute ("alloc_align", | |
1846 | TYPE_ATTRIBUTES (fntype)); | |
1847 | if (attrs) | |
1848 | val = bit_value_assume_aligned (stmt, attrs, val, true); | |
1849 | } | |
1850 | } | |
0b4b14ac | 1851 | is_constant = (val.lattice_val == CONSTANT); |
00d382a8 RG |
1852 | } |
1853 | ||
c853f62a JJ |
1854 | if (flag_tree_bit_ccp |
1855 | && ((is_constant && TREE_CODE (val.value) == INTEGER_CST) | |
1856 | || (!is_constant && likelyvalue != UNDEFINED)) | |
1857 | && gimple_get_lhs (stmt) | |
1858 | && TREE_CODE (gimple_get_lhs (stmt)) == SSA_NAME) | |
1859 | { | |
1860 | tree lhs = gimple_get_lhs (stmt); | |
807e902e KZ |
1861 | wide_int nonzero_bits = get_nonzero_bits (lhs); |
1862 | if (nonzero_bits != -1) | |
c853f62a JJ |
1863 | { |
1864 | if (!is_constant) | |
1865 | { | |
1866 | val.lattice_val = CONSTANT; | |
1867 | val.value = build_zero_cst (TREE_TYPE (lhs)); | |
807e902e | 1868 | val.mask = extend_mask (nonzero_bits); |
c853f62a JJ |
1869 | is_constant = true; |
1870 | } | |
1871 | else | |
1872 | { | |
807e902e KZ |
1873 | if (wi::bit_and_not (val.value, nonzero_bits) != 0) |
1874 | val.value = wide_int_to_tree (TREE_TYPE (lhs), | |
1875 | nonzero_bits & val.value); | |
1876 | if (nonzero_bits == 0) | |
1877 | val.mask = 0; | |
c853f62a | 1878 | else |
807e902e | 1879 | val.mask = val.mask & extend_mask (nonzero_bits); |
c853f62a JJ |
1880 | } |
1881 | } | |
1882 | } | |
1883 | ||
0b4b14ac | 1884 | if (!is_constant) |
6de9cd9a DN |
1885 | { |
1886 | /* The statement produced a nonconstant value. If the statement | |
0bca51f0 DN |
1887 | had UNDEFINED operands, then the result of the statement |
1888 | should be UNDEFINED. Otherwise, the statement is VARYING. */ | |
106dec71 | 1889 | if (likelyvalue == UNDEFINED) |
0b4b14ac RG |
1890 | { |
1891 | val.lattice_val = likelyvalue; | |
807e902e | 1892 | val.mask = 0; |
0b4b14ac | 1893 | } |
a318e3ac | 1894 | else |
0b4b14ac RG |
1895 | { |
1896 | val.lattice_val = VARYING; | |
807e902e | 1897 | val.mask = -1; |
0b4b14ac | 1898 | } |
a318e3ac | 1899 | |
0bca51f0 | 1900 | val.value = NULL_TREE; |
6de9cd9a | 1901 | } |
750628d8 DN |
1902 | |
1903 | return val; | |
6de9cd9a DN |
1904 | } |
1905 | ||
c203e8a7 | 1906 | typedef hash_table<pointer_hash<gimple_statement_base> > gimple_htab; |
0823efed | 1907 | |
2f31f742 TV |
1908 | /* Given a BUILT_IN_STACK_SAVE value SAVED_VAL, insert a clobber of VAR before |
1909 | each matching BUILT_IN_STACK_RESTORE. Mark visited phis in VISITED. */ | |
1910 | ||
1911 | static void | |
0823efed | 1912 | insert_clobber_before_stack_restore (tree saved_val, tree var, |
c203e8a7 | 1913 | gimple_htab **visited) |
2f31f742 TV |
1914 | { |
1915 | gimple stmt, clobber_stmt; | |
1916 | tree clobber; | |
1917 | imm_use_iterator iter; | |
1918 | gimple_stmt_iterator i; | |
1919 | gimple *slot; | |
1920 | ||
1921 | FOR_EACH_IMM_USE_STMT (stmt, iter, saved_val) | |
1922 | if (gimple_call_builtin_p (stmt, BUILT_IN_STACK_RESTORE)) | |
1923 | { | |
9771b263 DN |
1924 | clobber = build_constructor (TREE_TYPE (var), |
1925 | NULL); | |
2f31f742 TV |
1926 | TREE_THIS_VOLATILE (clobber) = 1; |
1927 | clobber_stmt = gimple_build_assign (var, clobber); | |
1928 | ||
1929 | i = gsi_for_stmt (stmt); | |
1930 | gsi_insert_before (&i, clobber_stmt, GSI_SAME_STMT); | |
1931 | } | |
1932 | else if (gimple_code (stmt) == GIMPLE_PHI) | |
1933 | { | |
c203e8a7 TS |
1934 | if (!*visited) |
1935 | *visited = new gimple_htab (10); | |
2f31f742 | 1936 | |
c203e8a7 | 1937 | slot = (*visited)->find_slot (stmt, INSERT); |
2f31f742 TV |
1938 | if (*slot != NULL) |
1939 | continue; | |
1940 | ||
1941 | *slot = stmt; | |
1942 | insert_clobber_before_stack_restore (gimple_phi_result (stmt), var, | |
1943 | visited); | |
1944 | } | |
cefce769 EB |
1945 | else if (gimple_assign_ssa_name_copy_p (stmt)) |
1946 | insert_clobber_before_stack_restore (gimple_assign_lhs (stmt), var, | |
1947 | visited); | |
2f31f742 TV |
1948 | else |
1949 | gcc_assert (is_gimple_debug (stmt)); | |
1950 | } | |
1951 | ||
1952 | /* Advance the iterator to the previous non-debug gimple statement in the same | |
1953 | or dominating basic block. */ | |
1954 | ||
1955 | static inline void | |
1956 | gsi_prev_dom_bb_nondebug (gimple_stmt_iterator *i) | |
1957 | { | |
1958 | basic_block dom; | |
1959 | ||
1960 | gsi_prev_nondebug (i); | |
1961 | while (gsi_end_p (*i)) | |
1962 | { | |
1963 | dom = get_immediate_dominator (CDI_DOMINATORS, i->bb); | |
fefa31b5 | 1964 | if (dom == NULL || dom == ENTRY_BLOCK_PTR_FOR_FN (cfun)) |
2f31f742 TV |
1965 | return; |
1966 | ||
1967 | *i = gsi_last_bb (dom); | |
1968 | } | |
1969 | } | |
1970 | ||
1971 | /* Find a BUILT_IN_STACK_SAVE dominating gsi_stmt (I), and insert | |
b9bebd7f MJ |
1972 | a clobber of VAR before each matching BUILT_IN_STACK_RESTORE. |
1973 | ||
1974 | It is possible that BUILT_IN_STACK_SAVE cannot be find in a dominator when a | |
1975 | previous pass (such as DOM) duplicated it along multiple paths to a BB. In | |
1976 | that case the function gives up without inserting the clobbers. */ | |
2f31f742 TV |
1977 | |
1978 | static void | |
1979 | insert_clobbers_for_var (gimple_stmt_iterator i, tree var) | |
1980 | { | |
2f31f742 TV |
1981 | gimple stmt; |
1982 | tree saved_val; | |
c203e8a7 | 1983 | gimple_htab *visited = NULL; |
2f31f742 | 1984 | |
b9bebd7f | 1985 | for (; !gsi_end_p (i); gsi_prev_dom_bb_nondebug (&i)) |
2f31f742 TV |
1986 | { |
1987 | stmt = gsi_stmt (i); | |
1988 | ||
1989 | if (!gimple_call_builtin_p (stmt, BUILT_IN_STACK_SAVE)) | |
1990 | continue; | |
2f31f742 TV |
1991 | |
1992 | saved_val = gimple_call_lhs (stmt); | |
1993 | if (saved_val == NULL_TREE) | |
1994 | continue; | |
1995 | ||
1996 | insert_clobber_before_stack_restore (saved_val, var, &visited); | |
1997 | break; | |
1998 | } | |
1999 | ||
c203e8a7 | 2000 | delete visited; |
2f31f742 TV |
2001 | } |
2002 | ||
13e49da9 TV |
2003 | /* Detects a __builtin_alloca_with_align with constant size argument. Declares |
2004 | fixed-size array and returns the address, if found, otherwise returns | |
2005 | NULL_TREE. */ | |
1fed1006 TV |
2006 | |
2007 | static tree | |
13e49da9 | 2008 | fold_builtin_alloca_with_align (gimple stmt) |
1fed1006 TV |
2009 | { |
2010 | unsigned HOST_WIDE_INT size, threshold, n_elem; | |
2011 | tree lhs, arg, block, var, elem_type, array_type; | |
1fed1006 TV |
2012 | |
2013 | /* Get lhs. */ | |
2014 | lhs = gimple_call_lhs (stmt); | |
2015 | if (lhs == NULL_TREE) | |
2016 | return NULL_TREE; | |
2017 | ||
2018 | /* Detect constant argument. */ | |
2019 | arg = get_constant_value (gimple_call_arg (stmt, 0)); | |
5d882cc1 RG |
2020 | if (arg == NULL_TREE |
2021 | || TREE_CODE (arg) != INTEGER_CST | |
cc269bb6 | 2022 | || !tree_fits_uhwi_p (arg)) |
1fed1006 | 2023 | return NULL_TREE; |
5d882cc1 | 2024 | |
eb1ce453 | 2025 | size = tree_to_uhwi (arg); |
1fed1006 | 2026 | |
13e49da9 | 2027 | /* Heuristic: don't fold large allocas. */ |
1fed1006 | 2028 | threshold = (unsigned HOST_WIDE_INT)PARAM_VALUE (PARAM_LARGE_STACK_FRAME); |
13e49da9 TV |
2029 | /* In case the alloca is located at function entry, it has the same lifetime |
2030 | as a declared array, so we allow a larger size. */ | |
1fed1006 TV |
2031 | block = gimple_block (stmt); |
2032 | if (!(cfun->after_inlining | |
2033 | && TREE_CODE (BLOCK_SUPERCONTEXT (block)) == FUNCTION_DECL)) | |
2034 | threshold /= 10; | |
2035 | if (size > threshold) | |
2036 | return NULL_TREE; | |
2037 | ||
2038 | /* Declare array. */ | |
2039 | elem_type = build_nonstandard_integer_type (BITS_PER_UNIT, 1); | |
2040 | n_elem = size * 8 / BITS_PER_UNIT; | |
1fed1006 TV |
2041 | array_type = build_array_type_nelts (elem_type, n_elem); |
2042 | var = create_tmp_var (array_type, NULL); | |
13e49da9 | 2043 | DECL_ALIGN (var) = TREE_INT_CST_LOW (gimple_call_arg (stmt, 1)); |
703ffc30 TV |
2044 | { |
2045 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (lhs); | |
2046 | if (pi != NULL && !pi->pt.anything) | |
2047 | { | |
2048 | bool singleton_p; | |
2049 | unsigned uid; | |
2050 | singleton_p = pt_solution_singleton_p (&pi->pt, &uid); | |
2051 | gcc_assert (singleton_p); | |
2052 | SET_DECL_PT_UID (var, uid); | |
2053 | } | |
2054 | } | |
1fed1006 TV |
2055 | |
2056 | /* Fold alloca to the address of the array. */ | |
2057 | return fold_convert (TREE_TYPE (lhs), build_fold_addr_expr (var)); | |
2058 | } | |
2059 | ||
f61e18ec RG |
2060 | /* Fold the stmt at *GSI with CCP specific information that propagating |
2061 | and regular folding does not catch. */ | |
2062 | ||
2063 | static bool | |
2064 | ccp_fold_stmt (gimple_stmt_iterator *gsi) | |
2065 | { | |
2066 | gimple stmt = gsi_stmt (*gsi); | |
f61e18ec | 2067 | |
830bc550 RG |
2068 | switch (gimple_code (stmt)) |
2069 | { | |
2070 | case GIMPLE_COND: | |
2071 | { | |
11478306 | 2072 | ccp_prop_value_t val; |
830bc550 RG |
2073 | /* Statement evaluation will handle type mismatches in constants |
2074 | more gracefully than the final propagation. This allows us to | |
2075 | fold more conditionals here. */ | |
2076 | val = evaluate_stmt (stmt); | |
2077 | if (val.lattice_val != CONSTANT | |
807e902e | 2078 | || val.mask != 0) |
830bc550 RG |
2079 | return false; |
2080 | ||
0b4b14ac RG |
2081 | if (dump_file) |
2082 | { | |
2083 | fprintf (dump_file, "Folding predicate "); | |
2084 | print_gimple_expr (dump_file, stmt, 0, 0); | |
2085 | fprintf (dump_file, " to "); | |
2086 | print_generic_expr (dump_file, val.value, 0); | |
2087 | fprintf (dump_file, "\n"); | |
2088 | } | |
2089 | ||
830bc550 RG |
2090 | if (integer_zerop (val.value)) |
2091 | gimple_cond_make_false (stmt); | |
2092 | else | |
2093 | gimple_cond_make_true (stmt); | |
f61e18ec | 2094 | |
830bc550 RG |
2095 | return true; |
2096 | } | |
f61e18ec | 2097 | |
830bc550 RG |
2098 | case GIMPLE_CALL: |
2099 | { | |
2100 | tree lhs = gimple_call_lhs (stmt); | |
45a5b21a | 2101 | int flags = gimple_call_flags (stmt); |
84d77ca6 | 2102 | tree val; |
830bc550 RG |
2103 | tree argt; |
2104 | bool changed = false; | |
2105 | unsigned i; | |
2106 | ||
2107 | /* If the call was folded into a constant make sure it goes | |
2108 | away even if we cannot propagate into all uses because of | |
2109 | type issues. */ | |
2110 | if (lhs | |
2111 | && TREE_CODE (lhs) == SSA_NAME | |
45a5b21a JJ |
2112 | && (val = get_constant_value (lhs)) |
2113 | /* Don't optimize away calls that have side-effects. */ | |
2114 | && (flags & (ECF_CONST|ECF_PURE)) != 0 | |
2115 | && (flags & ECF_LOOPING_CONST_OR_PURE) == 0) | |
830bc550 | 2116 | { |
84d77ca6 | 2117 | tree new_rhs = unshare_expr (val); |
eb6b98c7 | 2118 | bool res; |
830bc550 RG |
2119 | if (!useless_type_conversion_p (TREE_TYPE (lhs), |
2120 | TREE_TYPE (new_rhs))) | |
2121 | new_rhs = fold_convert (TREE_TYPE (lhs), new_rhs); | |
eb6b98c7 RG |
2122 | res = update_call_from_tree (gsi, new_rhs); |
2123 | gcc_assert (res); | |
830bc550 RG |
2124 | return true; |
2125 | } | |
2126 | ||
25583c4f RS |
2127 | /* Internal calls provide no argument types, so the extra laxity |
2128 | for normal calls does not apply. */ | |
2129 | if (gimple_call_internal_p (stmt)) | |
2130 | return false; | |
2131 | ||
13e49da9 TV |
2132 | /* The heuristic of fold_builtin_alloca_with_align differs before and |
2133 | after inlining, so we don't require the arg to be changed into a | |
2134 | constant for folding, but just to be constant. */ | |
2135 | if (gimple_call_builtin_p (stmt, BUILT_IN_ALLOCA_WITH_ALIGN)) | |
1fed1006 | 2136 | { |
13e49da9 | 2137 | tree new_rhs = fold_builtin_alloca_with_align (stmt); |
5d882cc1 RG |
2138 | if (new_rhs) |
2139 | { | |
2140 | bool res = update_call_from_tree (gsi, new_rhs); | |
2f31f742 | 2141 | tree var = TREE_OPERAND (TREE_OPERAND (new_rhs, 0),0); |
5d882cc1 | 2142 | gcc_assert (res); |
2f31f742 | 2143 | insert_clobbers_for_var (*gsi, var); |
5d882cc1 RG |
2144 | return true; |
2145 | } | |
1fed1006 TV |
2146 | } |
2147 | ||
830bc550 RG |
2148 | /* Propagate into the call arguments. Compared to replace_uses_in |
2149 | this can use the argument slot types for type verification | |
2150 | instead of the current argument type. We also can safely | |
2151 | drop qualifiers here as we are dealing with constants anyway. */ | |
9bfc434b | 2152 | argt = TYPE_ARG_TYPES (gimple_call_fntype (stmt)); |
830bc550 RG |
2153 | for (i = 0; i < gimple_call_num_args (stmt) && argt; |
2154 | ++i, argt = TREE_CHAIN (argt)) | |
2155 | { | |
2156 | tree arg = gimple_call_arg (stmt, i); | |
2157 | if (TREE_CODE (arg) == SSA_NAME | |
84d77ca6 | 2158 | && (val = get_constant_value (arg)) |
830bc550 RG |
2159 | && useless_type_conversion_p |
2160 | (TYPE_MAIN_VARIANT (TREE_VALUE (argt)), | |
84d77ca6 | 2161 | TYPE_MAIN_VARIANT (TREE_TYPE (val)))) |
830bc550 | 2162 | { |
84d77ca6 | 2163 | gimple_call_set_arg (stmt, i, unshare_expr (val)); |
830bc550 RG |
2164 | changed = true; |
2165 | } | |
2166 | } | |
74e80a24 | 2167 | |
830bc550 RG |
2168 | return changed; |
2169 | } | |
f61e18ec | 2170 | |
5c95f07b RG |
2171 | case GIMPLE_ASSIGN: |
2172 | { | |
2173 | tree lhs = gimple_assign_lhs (stmt); | |
84d77ca6 | 2174 | tree val; |
5c95f07b RG |
2175 | |
2176 | /* If we have a load that turned out to be constant replace it | |
2177 | as we cannot propagate into all uses in all cases. */ | |
2178 | if (gimple_assign_single_p (stmt) | |
2179 | && TREE_CODE (lhs) == SSA_NAME | |
84d77ca6 | 2180 | && (val = get_constant_value (lhs))) |
5c95f07b | 2181 | { |
84d77ca6 | 2182 | tree rhs = unshare_expr (val); |
5c95f07b | 2183 | if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs))) |
70f34814 | 2184 | rhs = fold_build1 (VIEW_CONVERT_EXPR, TREE_TYPE (lhs), rhs); |
5c95f07b RG |
2185 | gimple_assign_set_rhs_from_tree (gsi, rhs); |
2186 | return true; | |
2187 | } | |
2188 | ||
2189 | return false; | |
2190 | } | |
2191 | ||
830bc550 RG |
2192 | default: |
2193 | return false; | |
2194 | } | |
f61e18ec RG |
2195 | } |
2196 | ||
750628d8 | 2197 | /* Visit the assignment statement STMT. Set the value of its LHS to the |
0bca51f0 DN |
2198 | value computed by the RHS and store LHS in *OUTPUT_P. If STMT |
2199 | creates virtual definitions, set the value of each new name to that | |
726a989a RB |
2200 | of the RHS (if we can derive a constant out of the RHS). |
2201 | Value-returning call statements also perform an assignment, and | |
2202 | are handled here. */ | |
6de9cd9a | 2203 | |
750628d8 | 2204 | static enum ssa_prop_result |
726a989a | 2205 | visit_assignment (gimple stmt, tree *output_p) |
6de9cd9a | 2206 | { |
11478306 | 2207 | ccp_prop_value_t val; |
0bca51f0 | 2208 | enum ssa_prop_result retval; |
6de9cd9a | 2209 | |
726a989a | 2210 | tree lhs = gimple_get_lhs (stmt); |
6de9cd9a | 2211 | |
726a989a RB |
2212 | gcc_assert (gimple_code (stmt) != GIMPLE_CALL |
2213 | || gimple_call_lhs (stmt) != NULL_TREE); | |
2214 | ||
84d77ca6 RG |
2215 | if (gimple_assign_single_p (stmt) |
2216 | && gimple_assign_rhs_code (stmt) == SSA_NAME) | |
2217 | /* For a simple copy operation, we copy the lattice values. */ | |
2218 | val = *get_value (gimple_assign_rhs1 (stmt)); | |
750628d8 | 2219 | else |
726a989a RB |
2220 | /* Evaluate the statement, which could be |
2221 | either a GIMPLE_ASSIGN or a GIMPLE_CALL. */ | |
87e1e42b | 2222 | val = evaluate_stmt (stmt); |
6de9cd9a | 2223 | |
0bca51f0 | 2224 | retval = SSA_PROP_NOT_INTERESTING; |
6de9cd9a | 2225 | |
750628d8 | 2226 | /* Set the lattice value of the statement's output. */ |
0bca51f0 | 2227 | if (TREE_CODE (lhs) == SSA_NAME) |
6de9cd9a | 2228 | { |
0bca51f0 DN |
2229 | /* If STMT is an assignment to an SSA_NAME, we only have one |
2230 | value to set. */ | |
2231 | if (set_lattice_value (lhs, val)) | |
2232 | { | |
2233 | *output_p = lhs; | |
2234 | if (val.lattice_val == VARYING) | |
2235 | retval = SSA_PROP_VARYING; | |
2236 | else | |
2237 | retval = SSA_PROP_INTERESTING; | |
2238 | } | |
6de9cd9a | 2239 | } |
0bca51f0 DN |
2240 | |
2241 | return retval; | |
6de9cd9a DN |
2242 | } |
2243 | ||
6de9cd9a | 2244 | |
750628d8 DN |
2245 | /* Visit the conditional statement STMT. Return SSA_PROP_INTERESTING |
2246 | if it can determine which edge will be taken. Otherwise, return | |
2247 | SSA_PROP_VARYING. */ | |
2248 | ||
2249 | static enum ssa_prop_result | |
726a989a | 2250 | visit_cond_stmt (gimple stmt, edge *taken_edge_p) |
6de9cd9a | 2251 | { |
11478306 | 2252 | ccp_prop_value_t val; |
750628d8 DN |
2253 | basic_block block; |
2254 | ||
726a989a | 2255 | block = gimple_bb (stmt); |
750628d8 | 2256 | val = evaluate_stmt (stmt); |
0b4b14ac | 2257 | if (val.lattice_val != CONSTANT |
807e902e | 2258 | || val.mask != 0) |
0b4b14ac | 2259 | return SSA_PROP_VARYING; |
750628d8 DN |
2260 | |
2261 | /* Find which edge out of the conditional block will be taken and add it | |
2262 | to the worklist. If no single edge can be determined statically, | |
2263 | return SSA_PROP_VARYING to feed all the outgoing edges to the | |
2264 | propagation engine. */ | |
0b4b14ac | 2265 | *taken_edge_p = find_taken_edge (block, val.value); |
750628d8 DN |
2266 | if (*taken_edge_p) |
2267 | return SSA_PROP_INTERESTING; | |
2268 | else | |
2269 | return SSA_PROP_VARYING; | |
6de9cd9a DN |
2270 | } |
2271 | ||
6de9cd9a | 2272 | |
750628d8 DN |
2273 | /* Evaluate statement STMT. If the statement produces an output value and |
2274 | its evaluation changes the lattice value of its output, return | |
2275 | SSA_PROP_INTERESTING and set *OUTPUT_P to the SSA_NAME holding the | |
2276 | output value. | |
b8698a0f | 2277 | |
750628d8 DN |
2278 | If STMT is a conditional branch and we can determine its truth |
2279 | value, set *TAKEN_EDGE_P accordingly. If STMT produces a varying | |
2280 | value, return SSA_PROP_VARYING. */ | |
6de9cd9a | 2281 | |
750628d8 | 2282 | static enum ssa_prop_result |
726a989a | 2283 | ccp_visit_stmt (gimple stmt, edge *taken_edge_p, tree *output_p) |
750628d8 | 2284 | { |
750628d8 DN |
2285 | tree def; |
2286 | ssa_op_iter iter; | |
6de9cd9a | 2287 | |
750628d8 | 2288 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6de9cd9a | 2289 | { |
0bca51f0 | 2290 | fprintf (dump_file, "\nVisiting statement:\n"); |
726a989a | 2291 | print_gimple_stmt (dump_file, stmt, 0, dump_flags); |
6de9cd9a | 2292 | } |
6de9cd9a | 2293 | |
726a989a | 2294 | switch (gimple_code (stmt)) |
6de9cd9a | 2295 | { |
726a989a RB |
2296 | case GIMPLE_ASSIGN: |
2297 | /* If the statement is an assignment that produces a single | |
2298 | output value, evaluate its RHS to see if the lattice value of | |
2299 | its output has changed. */ | |
2300 | return visit_assignment (stmt, output_p); | |
2301 | ||
2302 | case GIMPLE_CALL: | |
2303 | /* A value-returning call also performs an assignment. */ | |
2304 | if (gimple_call_lhs (stmt) != NULL_TREE) | |
2305 | return visit_assignment (stmt, output_p); | |
2306 | break; | |
2307 | ||
2308 | case GIMPLE_COND: | |
2309 | case GIMPLE_SWITCH: | |
2310 | /* If STMT is a conditional branch, see if we can determine | |
2311 | which branch will be taken. */ | |
2312 | /* FIXME. It appears that we should be able to optimize | |
2313 | computed GOTOs here as well. */ | |
2314 | return visit_cond_stmt (stmt, taken_edge_p); | |
2315 | ||
2316 | default: | |
2317 | break; | |
6de9cd9a | 2318 | } |
6de9cd9a | 2319 | |
750628d8 DN |
2320 | /* Any other kind of statement is not interesting for constant |
2321 | propagation and, therefore, not worth simulating. */ | |
750628d8 DN |
2322 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2323 | fprintf (dump_file, "No interesting values produced. Marked VARYING.\n"); | |
6de9cd9a | 2324 | |
750628d8 DN |
2325 | /* Definitions made by statements other than assignments to |
2326 | SSA_NAMEs represent unknown modifications to their outputs. | |
2327 | Mark them VARYING. */ | |
0bca51f0 DN |
2328 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS) |
2329 | { | |
11478306 | 2330 | ccp_prop_value_t v = { VARYING, NULL_TREE, -1 }; |
0bca51f0 DN |
2331 | set_lattice_value (def, v); |
2332 | } | |
6de9cd9a | 2333 | |
750628d8 DN |
2334 | return SSA_PROP_VARYING; |
2335 | } | |
6de9cd9a | 2336 | |
6de9cd9a | 2337 | |
0bca51f0 | 2338 | /* Main entry point for SSA Conditional Constant Propagation. */ |
750628d8 | 2339 | |
3253eafb | 2340 | static unsigned int |
dce2b2f6 | 2341 | do_ssa_ccp (void) |
750628d8 | 2342 | { |
2f31f742 TV |
2343 | unsigned int todo = 0; |
2344 | calculate_dominance_info (CDI_DOMINATORS); | |
750628d8 DN |
2345 | ccp_initialize (); |
2346 | ssa_propagate (ccp_visit_stmt, ccp_visit_phi_node); | |
3253eafb | 2347 | if (ccp_finalize ()) |
c0e50f72 | 2348 | todo = (TODO_cleanup_cfg | TODO_update_ssa); |
2f31f742 TV |
2349 | free_dominance_info (CDI_DOMINATORS); |
2350 | return todo; | |
6de9cd9a DN |
2351 | } |
2352 | ||
173b818d | 2353 | |
27a4cd48 DM |
2354 | namespace { |
2355 | ||
2356 | const pass_data pass_data_ccp = | |
750628d8 | 2357 | { |
27a4cd48 DM |
2358 | GIMPLE_PASS, /* type */ |
2359 | "ccp", /* name */ | |
2360 | OPTGROUP_NONE, /* optinfo_flags */ | |
27a4cd48 DM |
2361 | TV_TREE_CCP, /* tv_id */ |
2362 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
2363 | 0, /* properties_provided */ | |
2364 | 0, /* properties_destroyed */ | |
2365 | 0, /* todo_flags_start */ | |
3bea341f | 2366 | TODO_update_address_taken, /* todo_flags_finish */ |
750628d8 | 2367 | }; |
6de9cd9a | 2368 | |
27a4cd48 DM |
2369 | class pass_ccp : public gimple_opt_pass |
2370 | { | |
2371 | public: | |
c3284718 RS |
2372 | pass_ccp (gcc::context *ctxt) |
2373 | : gimple_opt_pass (pass_data_ccp, ctxt) | |
27a4cd48 DM |
2374 | {} |
2375 | ||
2376 | /* opt_pass methods: */ | |
65d3284b | 2377 | opt_pass * clone () { return new pass_ccp (m_ctxt); } |
1a3d085c | 2378 | virtual bool gate (function *) { return flag_tree_ccp != 0; } |
be55bfe6 | 2379 | virtual unsigned int execute (function *) { return do_ssa_ccp (); } |
27a4cd48 DM |
2380 | |
2381 | }; // class pass_ccp | |
2382 | ||
2383 | } // anon namespace | |
2384 | ||
2385 | gimple_opt_pass * | |
2386 | make_pass_ccp (gcc::context *ctxt) | |
2387 | { | |
2388 | return new pass_ccp (ctxt); | |
2389 | } | |
2390 | ||
6de9cd9a | 2391 | |
726a989a | 2392 | |
cb8e078d JJ |
2393 | /* Try to optimize out __builtin_stack_restore. Optimize it out |
2394 | if there is another __builtin_stack_restore in the same basic | |
2395 | block and no calls or ASM_EXPRs are in between, or if this block's | |
2396 | only outgoing edge is to EXIT_BLOCK and there are no calls or | |
2397 | ASM_EXPRs after this __builtin_stack_restore. */ | |
2398 | ||
2399 | static tree | |
726a989a | 2400 | optimize_stack_restore (gimple_stmt_iterator i) |
cb8e078d | 2401 | { |
ff9d1adc RH |
2402 | tree callee; |
2403 | gimple stmt; | |
726a989a RB |
2404 | |
2405 | basic_block bb = gsi_bb (i); | |
2406 | gimple call = gsi_stmt (i); | |
cb8e078d | 2407 | |
726a989a RB |
2408 | if (gimple_code (call) != GIMPLE_CALL |
2409 | || gimple_call_num_args (call) != 1 | |
2410 | || TREE_CODE (gimple_call_arg (call, 0)) != SSA_NAME | |
2411 | || !POINTER_TYPE_P (TREE_TYPE (gimple_call_arg (call, 0)))) | |
cb8e078d JJ |
2412 | return NULL_TREE; |
2413 | ||
726a989a | 2414 | for (gsi_next (&i); !gsi_end_p (i); gsi_next (&i)) |
cb8e078d | 2415 | { |
726a989a RB |
2416 | stmt = gsi_stmt (i); |
2417 | if (gimple_code (stmt) == GIMPLE_ASM) | |
cb8e078d | 2418 | return NULL_TREE; |
726a989a | 2419 | if (gimple_code (stmt) != GIMPLE_CALL) |
cb8e078d JJ |
2420 | continue; |
2421 | ||
726a989a | 2422 | callee = gimple_call_fndecl (stmt); |
12f9ddbc RG |
2423 | if (!callee |
2424 | || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL | |
2425 | /* All regular builtins are ok, just obviously not alloca. */ | |
13e49da9 TV |
2426 | || DECL_FUNCTION_CODE (callee) == BUILT_IN_ALLOCA |
2427 | || DECL_FUNCTION_CODE (callee) == BUILT_IN_ALLOCA_WITH_ALIGN) | |
cb8e078d JJ |
2428 | return NULL_TREE; |
2429 | ||
2430 | if (DECL_FUNCTION_CODE (callee) == BUILT_IN_STACK_RESTORE) | |
ff9d1adc | 2431 | goto second_stack_restore; |
cb8e078d JJ |
2432 | } |
2433 | ||
ff9d1adc | 2434 | if (!gsi_end_p (i)) |
cb8e078d JJ |
2435 | return NULL_TREE; |
2436 | ||
ff9d1adc RH |
2437 | /* Allow one successor of the exit block, or zero successors. */ |
2438 | switch (EDGE_COUNT (bb->succs)) | |
2439 | { | |
2440 | case 0: | |
2441 | break; | |
2442 | case 1: | |
fefa31b5 | 2443 | if (single_succ_edge (bb)->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
ff9d1adc RH |
2444 | return NULL_TREE; |
2445 | break; | |
2446 | default: | |
2447 | return NULL_TREE; | |
2448 | } | |
2449 | second_stack_restore: | |
cb8e078d | 2450 | |
ff9d1adc RH |
2451 | /* If there's exactly one use, then zap the call to __builtin_stack_save. |
2452 | If there are multiple uses, then the last one should remove the call. | |
2453 | In any case, whether the call to __builtin_stack_save can be removed | |
2454 | or not is irrelevant to removing the call to __builtin_stack_restore. */ | |
2455 | if (has_single_use (gimple_call_arg (call, 0))) | |
2456 | { | |
2457 | gimple stack_save = SSA_NAME_DEF_STMT (gimple_call_arg (call, 0)); | |
2458 | if (is_gimple_call (stack_save)) | |
2459 | { | |
2460 | callee = gimple_call_fndecl (stack_save); | |
2461 | if (callee | |
2462 | && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL | |
2463 | && DECL_FUNCTION_CODE (callee) == BUILT_IN_STACK_SAVE) | |
2464 | { | |
2465 | gimple_stmt_iterator stack_save_gsi; | |
2466 | tree rhs; | |
cb8e078d | 2467 | |
ff9d1adc RH |
2468 | stack_save_gsi = gsi_for_stmt (stack_save); |
2469 | rhs = build_int_cst (TREE_TYPE (gimple_call_arg (call, 0)), 0); | |
2470 | update_call_from_tree (&stack_save_gsi, rhs); | |
2471 | } | |
2472 | } | |
2473 | } | |
cb8e078d | 2474 | |
726a989a | 2475 | /* No effect, so the statement will be deleted. */ |
cb8e078d JJ |
2476 | return integer_zero_node; |
2477 | } | |
726a989a | 2478 | |
d7bd8aeb JJ |
2479 | /* If va_list type is a simple pointer and nothing special is needed, |
2480 | optimize __builtin_va_start (&ap, 0) into ap = __builtin_next_arg (0), | |
2481 | __builtin_va_end (&ap) out as NOP and __builtin_va_copy into a simple | |
2482 | pointer assignment. */ | |
2483 | ||
2484 | static tree | |
726a989a | 2485 | optimize_stdarg_builtin (gimple call) |
d7bd8aeb | 2486 | { |
35cbb299 | 2487 | tree callee, lhs, rhs, cfun_va_list; |
d7bd8aeb | 2488 | bool va_list_simple_ptr; |
db3927fb | 2489 | location_t loc = gimple_location (call); |
d7bd8aeb | 2490 | |
726a989a | 2491 | if (gimple_code (call) != GIMPLE_CALL) |
d7bd8aeb JJ |
2492 | return NULL_TREE; |
2493 | ||
726a989a | 2494 | callee = gimple_call_fndecl (call); |
35cbb299 KT |
2495 | |
2496 | cfun_va_list = targetm.fn_abi_va_list (callee); | |
2497 | va_list_simple_ptr = POINTER_TYPE_P (cfun_va_list) | |
2498 | && (TREE_TYPE (cfun_va_list) == void_type_node | |
2499 | || TREE_TYPE (cfun_va_list) == char_type_node); | |
2500 | ||
d7bd8aeb JJ |
2501 | switch (DECL_FUNCTION_CODE (callee)) |
2502 | { | |
2503 | case BUILT_IN_VA_START: | |
2504 | if (!va_list_simple_ptr | |
2505 | || targetm.expand_builtin_va_start != NULL | |
f25a65f5 | 2506 | || !builtin_decl_explicit_p (BUILT_IN_NEXT_ARG)) |
d7bd8aeb JJ |
2507 | return NULL_TREE; |
2508 | ||
726a989a | 2509 | if (gimple_call_num_args (call) != 2) |
d7bd8aeb JJ |
2510 | return NULL_TREE; |
2511 | ||
726a989a | 2512 | lhs = gimple_call_arg (call, 0); |
d7bd8aeb JJ |
2513 | if (!POINTER_TYPE_P (TREE_TYPE (lhs)) |
2514 | || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs))) | |
35cbb299 | 2515 | != TYPE_MAIN_VARIANT (cfun_va_list)) |
d7bd8aeb | 2516 | return NULL_TREE; |
b8698a0f | 2517 | |
db3927fb | 2518 | lhs = build_fold_indirect_ref_loc (loc, lhs); |
e79983f4 | 2519 | rhs = build_call_expr_loc (loc, builtin_decl_explicit (BUILT_IN_NEXT_ARG), |
726a989a | 2520 | 1, integer_zero_node); |
db3927fb | 2521 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); |
d7bd8aeb JJ |
2522 | return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs); |
2523 | ||
2524 | case BUILT_IN_VA_COPY: | |
2525 | if (!va_list_simple_ptr) | |
2526 | return NULL_TREE; | |
2527 | ||
726a989a | 2528 | if (gimple_call_num_args (call) != 2) |
d7bd8aeb JJ |
2529 | return NULL_TREE; |
2530 | ||
726a989a | 2531 | lhs = gimple_call_arg (call, 0); |
d7bd8aeb JJ |
2532 | if (!POINTER_TYPE_P (TREE_TYPE (lhs)) |
2533 | || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs))) | |
35cbb299 | 2534 | != TYPE_MAIN_VARIANT (cfun_va_list)) |
d7bd8aeb JJ |
2535 | return NULL_TREE; |
2536 | ||
db3927fb | 2537 | lhs = build_fold_indirect_ref_loc (loc, lhs); |
726a989a | 2538 | rhs = gimple_call_arg (call, 1); |
d7bd8aeb | 2539 | if (TYPE_MAIN_VARIANT (TREE_TYPE (rhs)) |
35cbb299 | 2540 | != TYPE_MAIN_VARIANT (cfun_va_list)) |
d7bd8aeb JJ |
2541 | return NULL_TREE; |
2542 | ||
db3927fb | 2543 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); |
d7bd8aeb JJ |
2544 | return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs); |
2545 | ||
2546 | case BUILT_IN_VA_END: | |
726a989a | 2547 | /* No effect, so the statement will be deleted. */ |
d7bd8aeb JJ |
2548 | return integer_zero_node; |
2549 | ||
2550 | default: | |
2551 | gcc_unreachable (); | |
2552 | } | |
2553 | } | |
726a989a | 2554 | |
c61e5cc1 TV |
2555 | /* Attemp to make the block of __builtin_unreachable I unreachable by changing |
2556 | the incoming jumps. Return true if at least one jump was changed. */ | |
2557 | ||
2558 | static bool | |
2559 | optimize_unreachable (gimple_stmt_iterator i) | |
2560 | { | |
2561 | basic_block bb = gsi_bb (i); | |
2562 | gimple_stmt_iterator gsi; | |
2563 | gimple stmt; | |
2564 | edge_iterator ei; | |
2565 | edge e; | |
2566 | bool ret; | |
2567 | ||
2568 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
2569 | { | |
2570 | stmt = gsi_stmt (gsi); | |
2571 | ||
2572 | if (is_gimple_debug (stmt)) | |
2573 | continue; | |
2574 | ||
2575 | if (gimple_code (stmt) == GIMPLE_LABEL) | |
2576 | { | |
2577 | /* Verify we do not need to preserve the label. */ | |
2578 | if (FORCED_LABEL (gimple_label_label (stmt))) | |
2579 | return false; | |
2580 | ||
2581 | continue; | |
2582 | } | |
2583 | ||
2584 | /* Only handle the case that __builtin_unreachable is the first statement | |
2585 | in the block. We rely on DCE to remove stmts without side-effects | |
2586 | before __builtin_unreachable. */ | |
2587 | if (gsi_stmt (gsi) != gsi_stmt (i)) | |
2588 | return false; | |
2589 | } | |
2590 | ||
2591 | ret = false; | |
2592 | FOR_EACH_EDGE (e, ei, bb->preds) | |
2593 | { | |
2594 | gsi = gsi_last_bb (e->src); | |
cd356d96 UW |
2595 | if (gsi_end_p (gsi)) |
2596 | continue; | |
c61e5cc1 | 2597 | |
cd356d96 UW |
2598 | stmt = gsi_stmt (gsi); |
2599 | if (gimple_code (stmt) == GIMPLE_COND) | |
c61e5cc1 TV |
2600 | { |
2601 | if (e->flags & EDGE_TRUE_VALUE) | |
2602 | gimple_cond_make_false (stmt); | |
2603 | else if (e->flags & EDGE_FALSE_VALUE) | |
2604 | gimple_cond_make_true (stmt); | |
2605 | else | |
2606 | gcc_unreachable (); | |
bf3d1928 | 2607 | update_stmt (stmt); |
c61e5cc1 TV |
2608 | } |
2609 | else | |
2610 | { | |
2611 | /* Todo: handle other cases, f.i. switch statement. */ | |
2612 | continue; | |
2613 | } | |
2614 | ||
2615 | ret = true; | |
2616 | } | |
2617 | ||
2618 | return ret; | |
2619 | } | |
2620 | ||
6de9cd9a DN |
2621 | /* A simple pass that attempts to fold all builtin functions. This pass |
2622 | is run after we've propagated as many constants as we can. */ | |
2623 | ||
be55bfe6 TS |
2624 | namespace { |
2625 | ||
2626 | const pass_data pass_data_fold_builtins = | |
2627 | { | |
2628 | GIMPLE_PASS, /* type */ | |
2629 | "fab", /* name */ | |
2630 | OPTGROUP_NONE, /* optinfo_flags */ | |
be55bfe6 TS |
2631 | TV_NONE, /* tv_id */ |
2632 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
2633 | 0, /* properties_provided */ | |
2634 | 0, /* properties_destroyed */ | |
2635 | 0, /* todo_flags_start */ | |
3bea341f | 2636 | TODO_update_ssa, /* todo_flags_finish */ |
be55bfe6 TS |
2637 | }; |
2638 | ||
2639 | class pass_fold_builtins : public gimple_opt_pass | |
2640 | { | |
2641 | public: | |
2642 | pass_fold_builtins (gcc::context *ctxt) | |
2643 | : gimple_opt_pass (pass_data_fold_builtins, ctxt) | |
2644 | {} | |
2645 | ||
2646 | /* opt_pass methods: */ | |
2647 | opt_pass * clone () { return new pass_fold_builtins (m_ctxt); } | |
2648 | virtual unsigned int execute (function *); | |
2649 | ||
2650 | }; // class pass_fold_builtins | |
2651 | ||
2652 | unsigned int | |
2653 | pass_fold_builtins::execute (function *fun) | |
6de9cd9a | 2654 | { |
a7d6ba24 | 2655 | bool cfg_changed = false; |
6de9cd9a | 2656 | basic_block bb; |
7b0e48fb | 2657 | unsigned int todoflags = 0; |
b8698a0f | 2658 | |
be55bfe6 | 2659 | FOR_EACH_BB_FN (bb, fun) |
6de9cd9a | 2660 | { |
726a989a RB |
2661 | gimple_stmt_iterator i; |
2662 | for (i = gsi_start_bb (bb); !gsi_end_p (i); ) | |
6de9cd9a | 2663 | { |
726a989a | 2664 | gimple stmt, old_stmt; |
3daa26d0 | 2665 | tree callee; |
10a0d495 | 2666 | enum built_in_function fcode; |
6de9cd9a | 2667 | |
726a989a RB |
2668 | stmt = gsi_stmt (i); |
2669 | ||
2670 | if (gimple_code (stmt) != GIMPLE_CALL) | |
10a0d495 | 2671 | { |
f223bb13 JJ |
2672 | /* Remove all *ssaname_N ={v} {CLOBBER}; stmts, |
2673 | after the last GIMPLE DSE they aren't needed and might | |
2674 | unnecessarily keep the SSA_NAMEs live. */ | |
2675 | if (gimple_clobber_p (stmt)) | |
2676 | { | |
2677 | tree lhs = gimple_assign_lhs (stmt); | |
2678 | if (TREE_CODE (lhs) == MEM_REF | |
2679 | && TREE_CODE (TREE_OPERAND (lhs, 0)) == SSA_NAME) | |
2680 | { | |
2681 | unlink_stmt_vdef (stmt); | |
2682 | gsi_remove (&i, true); | |
2683 | release_defs (stmt); | |
2684 | continue; | |
2685 | } | |
2686 | } | |
726a989a | 2687 | gsi_next (&i); |
10a0d495 JJ |
2688 | continue; |
2689 | } | |
3daa26d0 | 2690 | |
726a989a | 2691 | callee = gimple_call_fndecl (stmt); |
6de9cd9a | 2692 | if (!callee || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL) |
10a0d495 | 2693 | { |
726a989a | 2694 | gsi_next (&i); |
10a0d495 JJ |
2695 | continue; |
2696 | } | |
53a8f709 | 2697 | |
3daa26d0 RB |
2698 | fcode = DECL_FUNCTION_CODE (callee); |
2699 | if (fold_stmt (&i)) | |
2700 | ; | |
2701 | else | |
2702 | { | |
2703 | tree result = NULL_TREE; | |
2704 | switch (DECL_FUNCTION_CODE (callee)) | |
2705 | { | |
2706 | case BUILT_IN_CONSTANT_P: | |
2707 | /* Resolve __builtin_constant_p. If it hasn't been | |
2708 | folded to integer_one_node by now, it's fairly | |
2709 | certain that the value simply isn't constant. */ | |
2710 | result = integer_zero_node; | |
2711 | break; | |
53a8f709 | 2712 | |
3daa26d0 RB |
2713 | case BUILT_IN_ASSUME_ALIGNED: |
2714 | /* Remove __builtin_assume_aligned. */ | |
2715 | result = gimple_call_arg (stmt, 0); | |
2716 | break; | |
6de9cd9a | 2717 | |
3daa26d0 RB |
2718 | case BUILT_IN_STACK_RESTORE: |
2719 | result = optimize_stack_restore (i); | |
2720 | if (result) | |
2721 | break; | |
2722 | gsi_next (&i); | |
2723 | continue; | |
45d439ac | 2724 | |
3daa26d0 RB |
2725 | case BUILT_IN_UNREACHABLE: |
2726 | if (optimize_unreachable (i)) | |
2727 | cfg_changed = true; | |
d7bd8aeb | 2728 | break; |
d7bd8aeb | 2729 | |
3daa26d0 RB |
2730 | case BUILT_IN_VA_START: |
2731 | case BUILT_IN_VA_END: | |
2732 | case BUILT_IN_VA_COPY: | |
2733 | /* These shouldn't be folded before pass_stdarg. */ | |
2734 | result = optimize_stdarg_builtin (stmt); | |
2735 | if (result) | |
2736 | break; | |
2737 | /* FALLTHRU */ | |
c61e5cc1 | 2738 | |
3daa26d0 RB |
2739 | default:; |
2740 | } | |
cb8e078d | 2741 | |
3daa26d0 RB |
2742 | if (!result) |
2743 | { | |
2744 | gsi_next (&i); | |
2745 | continue; | |
2746 | } | |
6de9cd9a | 2747 | |
3daa26d0 RB |
2748 | if (!update_call_from_tree (&i, result)) |
2749 | gimplify_and_update_call_from_tree (&i, result); | |
2750 | } | |
2751 | ||
2752 | todoflags |= TODO_update_address_taken; | |
c61e5cc1 | 2753 | |
6de9cd9a DN |
2754 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2755 | { | |
2756 | fprintf (dump_file, "Simplified\n "); | |
726a989a | 2757 | print_gimple_stmt (dump_file, stmt, 0, dump_flags); |
6de9cd9a DN |
2758 | } |
2759 | ||
726a989a | 2760 | old_stmt = stmt; |
726a989a | 2761 | stmt = gsi_stmt (i); |
cff4e50d | 2762 | update_stmt (stmt); |
cfaab3a9 | 2763 | |
726a989a RB |
2764 | if (maybe_clean_or_replace_eh_stmt (old_stmt, stmt) |
2765 | && gimple_purge_dead_eh_edges (bb)) | |
a7d6ba24 | 2766 | cfg_changed = true; |
6de9cd9a DN |
2767 | |
2768 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2769 | { | |
2770 | fprintf (dump_file, "to\n "); | |
726a989a | 2771 | print_gimple_stmt (dump_file, stmt, 0, dump_flags); |
6de9cd9a DN |
2772 | fprintf (dump_file, "\n"); |
2773 | } | |
10a0d495 JJ |
2774 | |
2775 | /* Retry the same statement if it changed into another | |
2776 | builtin, there might be new opportunities now. */ | |
726a989a | 2777 | if (gimple_code (stmt) != GIMPLE_CALL) |
10a0d495 | 2778 | { |
726a989a | 2779 | gsi_next (&i); |
10a0d495 JJ |
2780 | continue; |
2781 | } | |
726a989a | 2782 | callee = gimple_call_fndecl (stmt); |
10a0d495 | 2783 | if (!callee |
726a989a | 2784 | || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL |
10a0d495 | 2785 | || DECL_FUNCTION_CODE (callee) == fcode) |
726a989a | 2786 | gsi_next (&i); |
6de9cd9a DN |
2787 | } |
2788 | } | |
b8698a0f | 2789 | |
a7d6ba24 | 2790 | /* Delete unreachable blocks. */ |
7b0e48fb DB |
2791 | if (cfg_changed) |
2792 | todoflags |= TODO_cleanup_cfg; | |
b8698a0f | 2793 | |
7b0e48fb | 2794 | return todoflags; |
6de9cd9a DN |
2795 | } |
2796 | ||
27a4cd48 DM |
2797 | } // anon namespace |
2798 | ||
2799 | gimple_opt_pass * | |
2800 | make_pass_fold_builtins (gcc::context *ctxt) | |
2801 | { | |
2802 | return new pass_fold_builtins (ctxt); | |
2803 | } |