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