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4ee9c684 | 1 | /* Conditional constant propagation pass for the GNU compiler. |
d353bf18 | 2 | Copyright (C) 2000-2015 Free Software Foundation, Inc. |
4ee9c684 | 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. | |
48e1416a | 7 | |
4ee9c684 | 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 | |
8c4c00c1 | 10 | Free Software Foundation; either version 3, or (at your option) any |
4ee9c684 | 11 | later version. |
48e1416a | 12 | |
4ee9c684 | 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. | |
48e1416a | 17 | |
4ee9c684 | 18 | You should have received a copy of the GNU General Public License |
8c4c00c1 | 19 | along with GCC; see the file COPYING3. If not see |
20 | <http://www.gnu.org/licenses/>. */ | |
4ee9c684 | 21 | |
88dbf20f | 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 | ||
bfa30570 | 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. | |
88dbf20f | 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. | |
48e1416a | 65 | |
88dbf20f | 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 | ||
e913b5cd | 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 | ||
4ee9c684 | 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" | |
b20a8bb4 | 125 | #include "hash-set.h" |
126 | #include "machmode.h" | |
127 | #include "vec.h" | |
128 | #include "double-int.h" | |
129 | #include "input.h" | |
130 | #include "alias.h" | |
131 | #include "symtab.h" | |
132 | #include "wide-int.h" | |
133 | #include "inchash.h" | |
134 | #include "real.h" | |
4ee9c684 | 135 | #include "tree.h" |
b20a8bb4 | 136 | #include "fold-const.h" |
9ed99284 | 137 | #include "stor-layout.h" |
41511585 | 138 | #include "flags.h" |
4ee9c684 | 139 | #include "tm_p.h" |
94ea8568 | 140 | #include "predict.h" |
a3020f2f | 141 | #include "hard-reg-set.h" |
142 | #include "input.h" | |
41511585 | 143 | #include "function.h" |
94ea8568 | 144 | #include "dominance.h" |
145 | #include "cfg.h" | |
146 | #include "basic-block.h" | |
ce084dfc | 147 | #include "gimple-pretty-print.h" |
bc61cadb | 148 | #include "hash-table.h" |
149 | #include "tree-ssa-alias.h" | |
150 | #include "internal-fn.h" | |
151 | #include "gimple-fold.h" | |
152 | #include "tree-eh.h" | |
153 | #include "gimple-expr.h" | |
154 | #include "is-a.h" | |
073c1fd5 | 155 | #include "gimple.h" |
a8783bee | 156 | #include "gimplify.h" |
dcf1a1ec | 157 | #include "gimple-iterator.h" |
073c1fd5 | 158 | #include "gimple-ssa.h" |
159 | #include "tree-cfg.h" | |
160 | #include "tree-phinodes.h" | |
161 | #include "ssa-iterators.h" | |
9ed99284 | 162 | #include "stringpool.h" |
073c1fd5 | 163 | #include "tree-ssanames.h" |
4ee9c684 | 164 | #include "tree-pass.h" |
41511585 | 165 | #include "tree-ssa-propagate.h" |
5a4b7e1e | 166 | #include "value-prof.h" |
41511585 | 167 | #include "langhooks.h" |
8782adcf | 168 | #include "target.h" |
0b205f4c | 169 | #include "diagnostic-core.h" |
43fb76c1 | 170 | #include "dbgcnt.h" |
9a65cc0a | 171 | #include "params.h" |
e913b5cd | 172 | #include "wide-int-print.h" |
f7715905 | 173 | #include "builtins.h" |
058a1b7a | 174 | #include "tree-chkp.h" |
4ee9c684 | 175 | |
2dc10fae | 176 | |
4ee9c684 | 177 | /* Possible lattice values. */ |
178 | typedef enum | |
179 | { | |
bfa30570 | 180 | UNINITIALIZED, |
4ee9c684 | 181 | UNDEFINED, |
182 | CONSTANT, | |
183 | VARYING | |
88dbf20f | 184 | } ccp_lattice_t; |
4ee9c684 | 185 | |
9908fe4d | 186 | struct ccp_prop_value_t { |
14f101cf | 187 | /* Lattice value. */ |
188 | ccp_lattice_t lattice_val; | |
189 | ||
190 | /* Propagated value. */ | |
191 | tree value; | |
b7e55469 | 192 | |
e913b5cd | 193 | /* Mask that applies to the propagated value during CCP. For X |
194 | with a CONSTANT lattice value X & ~mask == value & ~mask. The | |
195 | zero bits in the mask cover constant values. The ones mean no | |
196 | information. */ | |
5de9d3ed | 197 | widest_int mask; |
14f101cf | 198 | }; |
199 | ||
88dbf20f | 200 | /* Array of propagated constant values. After propagation, |
201 | CONST_VAL[I].VALUE holds the constant value for SSA_NAME(I). If | |
202 | the constant is held in an SSA name representing a memory store | |
4fb5e5ca | 203 | (i.e., a VDEF), CONST_VAL[I].MEM_REF will contain the actual |
204 | memory reference used to store (i.e., the LHS of the assignment | |
205 | doing the store). */ | |
9908fe4d | 206 | static ccp_prop_value_t *const_val; |
285df01b | 207 | static unsigned n_const_val; |
4ee9c684 | 208 | |
9908fe4d | 209 | static void canonicalize_value (ccp_prop_value_t *); |
6688f8ec | 210 | static bool ccp_fold_stmt (gimple_stmt_iterator *); |
4af351a8 | 211 | |
88dbf20f | 212 | /* Dump constant propagation value VAL to file OUTF prefixed by PREFIX. */ |
01406fc0 | 213 | |
214 | static void | |
9908fe4d | 215 | dump_lattice_value (FILE *outf, const char *prefix, ccp_prop_value_t val) |
01406fc0 | 216 | { |
41511585 | 217 | switch (val.lattice_val) |
01406fc0 | 218 | { |
88dbf20f | 219 | case UNINITIALIZED: |
220 | fprintf (outf, "%sUNINITIALIZED", prefix); | |
221 | break; | |
41511585 | 222 | case UNDEFINED: |
223 | fprintf (outf, "%sUNDEFINED", prefix); | |
224 | break; | |
225 | case VARYING: | |
226 | fprintf (outf, "%sVARYING", prefix); | |
227 | break; | |
41511585 | 228 | case CONSTANT: |
b7e55469 | 229 | if (TREE_CODE (val.value) != INTEGER_CST |
796b6678 | 230 | || val.mask == 0) |
16ab4e97 | 231 | { |
232 | fprintf (outf, "%sCONSTANT ", prefix); | |
233 | print_generic_expr (outf, val.value, dump_flags); | |
234 | } | |
b7e55469 | 235 | else |
236 | { | |
28e557ef | 237 | widest_int cval = wi::bit_and_not (wi::to_widest (val.value), |
238 | val.mask); | |
e913b5cd | 239 | fprintf (outf, "%sCONSTANT ", prefix); |
240 | print_hex (cval, outf); | |
241 | fprintf (outf, " ("); | |
242 | print_hex (val.mask, outf); | |
243 | fprintf (outf, ")"); | |
b7e55469 | 244 | } |
41511585 | 245 | break; |
246 | default: | |
8c0963c4 | 247 | gcc_unreachable (); |
41511585 | 248 | } |
01406fc0 | 249 | } |
4ee9c684 | 250 | |
4ee9c684 | 251 | |
88dbf20f | 252 | /* Print lattice value VAL to stderr. */ |
253 | ||
9908fe4d | 254 | void debug_lattice_value (ccp_prop_value_t val); |
88dbf20f | 255 | |
4b987fac | 256 | DEBUG_FUNCTION void |
9908fe4d | 257 | debug_lattice_value (ccp_prop_value_t val) |
88dbf20f | 258 | { |
259 | dump_lattice_value (stderr, "", val); | |
260 | fprintf (stderr, "\n"); | |
261 | } | |
4ee9c684 | 262 | |
9c1be15e | 263 | /* Extend NONZERO_BITS to a full mask, with the upper bits being set. */ |
264 | ||
265 | static widest_int | |
266 | extend_mask (const wide_int &nonzero_bits) | |
267 | { | |
268 | return (wi::mask <widest_int> (wi::get_precision (nonzero_bits), true) | |
269 | | widest_int::from (nonzero_bits, UNSIGNED)); | |
270 | } | |
4ee9c684 | 271 | |
88dbf20f | 272 | /* Compute a default value for variable VAR and store it in the |
273 | CONST_VAL array. The following rules are used to get default | |
274 | values: | |
01406fc0 | 275 | |
88dbf20f | 276 | 1- Global and static variables that are declared constant are |
277 | considered CONSTANT. | |
278 | ||
279 | 2- Any other value is considered UNDEFINED. This is useful when | |
41511585 | 280 | considering PHI nodes. PHI arguments that are undefined do not |
281 | change the constant value of the PHI node, which allows for more | |
88dbf20f | 282 | constants to be propagated. |
4ee9c684 | 283 | |
8883e700 | 284 | 3- Variables defined by statements other than assignments and PHI |
88dbf20f | 285 | nodes are considered VARYING. |
4ee9c684 | 286 | |
8883e700 | 287 | 4- Initial values of variables that are not GIMPLE registers are |
bfa30570 | 288 | considered VARYING. */ |
4ee9c684 | 289 | |
9908fe4d | 290 | static ccp_prop_value_t |
88dbf20f | 291 | get_default_value (tree var) |
292 | { | |
9908fe4d | 293 | ccp_prop_value_t val = { UNINITIALIZED, NULL_TREE, 0 }; |
8edeb88b | 294 | gimple stmt; |
295 | ||
296 | stmt = SSA_NAME_DEF_STMT (var); | |
297 | ||
298 | if (gimple_nop_p (stmt)) | |
4ee9c684 | 299 | { |
8edeb88b | 300 | /* Variables defined by an empty statement are those used |
301 | before being initialized. If VAR is a local variable, we | |
302 | can assume initially that it is UNDEFINED, otherwise we must | |
303 | consider it VARYING. */ | |
7c782c9b | 304 | if (!virtual_operand_p (var) |
305 | && TREE_CODE (SSA_NAME_VAR (var)) == VAR_DECL) | |
8edeb88b | 306 | val.lattice_val = UNDEFINED; |
307 | else | |
b7e55469 | 308 | { |
309 | val.lattice_val = VARYING; | |
e913b5cd | 310 | val.mask = -1; |
fc08b993 | 311 | if (flag_tree_bit_ccp) |
312 | { | |
9c1be15e | 313 | wide_int nonzero_bits = get_nonzero_bits (var); |
314 | if (nonzero_bits != -1) | |
fc08b993 | 315 | { |
316 | val.lattice_val = CONSTANT; | |
317 | val.value = build_zero_cst (TREE_TYPE (var)); | |
9c1be15e | 318 | val.mask = extend_mask (nonzero_bits); |
fc08b993 | 319 | } |
320 | } | |
b7e55469 | 321 | } |
4ee9c684 | 322 | } |
b45b214a | 323 | else if (is_gimple_assign (stmt)) |
41511585 | 324 | { |
8edeb88b | 325 | tree cst; |
326 | if (gimple_assign_single_p (stmt) | |
327 | && DECL_P (gimple_assign_rhs1 (stmt)) | |
328 | && (cst = get_symbol_constant_value (gimple_assign_rhs1 (stmt)))) | |
88dbf20f | 329 | { |
8edeb88b | 330 | val.lattice_val = CONSTANT; |
331 | val.value = cst; | |
88dbf20f | 332 | } |
333 | else | |
b45b214a | 334 | { |
335 | /* Any other variable defined by an assignment is considered | |
336 | UNDEFINED. */ | |
337 | val.lattice_val = UNDEFINED; | |
338 | } | |
339 | } | |
340 | else if ((is_gimple_call (stmt) | |
341 | && gimple_call_lhs (stmt) != NULL_TREE) | |
342 | || gimple_code (stmt) == GIMPLE_PHI) | |
343 | { | |
344 | /* A variable defined by a call or a PHI node is considered | |
345 | UNDEFINED. */ | |
346 | val.lattice_val = UNDEFINED; | |
8edeb88b | 347 | } |
348 | else | |
349 | { | |
350 | /* Otherwise, VAR will never take on a constant value. */ | |
351 | val.lattice_val = VARYING; | |
e913b5cd | 352 | val.mask = -1; |
41511585 | 353 | } |
4ee9c684 | 354 | |
41511585 | 355 | return val; |
356 | } | |
4ee9c684 | 357 | |
4ee9c684 | 358 | |
bfa30570 | 359 | /* Get the constant value associated with variable VAR. */ |
4ee9c684 | 360 | |
9908fe4d | 361 | static inline ccp_prop_value_t * |
bfa30570 | 362 | get_value (tree var) |
88dbf20f | 363 | { |
9908fe4d | 364 | ccp_prop_value_t *val; |
bfa30570 | 365 | |
285df01b | 366 | if (const_val == NULL |
367 | || SSA_NAME_VERSION (var) >= n_const_val) | |
e004838d | 368 | return NULL; |
369 | ||
370 | val = &const_val[SSA_NAME_VERSION (var)]; | |
bfa30570 | 371 | if (val->lattice_val == UNINITIALIZED) |
4ee9c684 | 372 | *val = get_default_value (var); |
373 | ||
f5faab84 | 374 | canonicalize_value (val); |
4af351a8 | 375 | |
4ee9c684 | 376 | return val; |
377 | } | |
378 | ||
15d138c9 | 379 | /* Return the constant tree value associated with VAR. */ |
380 | ||
381 | static inline tree | |
382 | get_constant_value (tree var) | |
383 | { | |
9908fe4d | 384 | ccp_prop_value_t *val; |
98d92e3c | 385 | if (TREE_CODE (var) != SSA_NAME) |
386 | { | |
387 | if (is_gimple_min_invariant (var)) | |
388 | return var; | |
389 | return NULL_TREE; | |
390 | } | |
391 | val = get_value (var); | |
b7e55469 | 392 | if (val |
393 | && val->lattice_val == CONSTANT | |
394 | && (TREE_CODE (val->value) != INTEGER_CST | |
796b6678 | 395 | || val->mask == 0)) |
15d138c9 | 396 | return val->value; |
397 | return NULL_TREE; | |
398 | } | |
399 | ||
bfa30570 | 400 | /* Sets the value associated with VAR to VARYING. */ |
401 | ||
402 | static inline void | |
403 | set_value_varying (tree var) | |
404 | { | |
9908fe4d | 405 | ccp_prop_value_t *val = &const_val[SSA_NAME_VERSION (var)]; |
bfa30570 | 406 | |
407 | val->lattice_val = VARYING; | |
408 | val->value = NULL_TREE; | |
e913b5cd | 409 | val->mask = -1; |
bfa30570 | 410 | } |
4ee9c684 | 411 | |
0001b944 | 412 | /* For integer constants, make sure to drop TREE_OVERFLOW. */ |
b31eb493 | 413 | |
414 | static void | |
9908fe4d | 415 | canonicalize_value (ccp_prop_value_t *val) |
b31eb493 | 416 | { |
f5faab84 | 417 | if (val->lattice_val != CONSTANT) |
418 | return; | |
419 | ||
420 | if (TREE_OVERFLOW_P (val->value)) | |
421 | val->value = drop_tree_overflow (val->value); | |
b31eb493 | 422 | } |
423 | ||
b7e55469 | 424 | /* Return whether the lattice transition is valid. */ |
425 | ||
426 | static bool | |
9908fe4d | 427 | valid_lattice_transition (ccp_prop_value_t old_val, ccp_prop_value_t new_val) |
b7e55469 | 428 | { |
429 | /* Lattice transitions must always be monotonically increasing in | |
430 | value. */ | |
431 | if (old_val.lattice_val < new_val.lattice_val) | |
432 | return true; | |
433 | ||
434 | if (old_val.lattice_val != new_val.lattice_val) | |
435 | return false; | |
436 | ||
437 | if (!old_val.value && !new_val.value) | |
438 | return true; | |
439 | ||
440 | /* Now both lattice values are CONSTANT. */ | |
441 | ||
43c92e0a | 442 | /* Allow transitioning from PHI <&x, not executable> == &x |
443 | to PHI <&x, &y> == common alignment. */ | |
b7e55469 | 444 | if (TREE_CODE (old_val.value) != INTEGER_CST |
445 | && TREE_CODE (new_val.value) == INTEGER_CST) | |
446 | return true; | |
447 | ||
448 | /* Bit-lattices have to agree in the still valid bits. */ | |
449 | if (TREE_CODE (old_val.value) == INTEGER_CST | |
450 | && TREE_CODE (new_val.value) == INTEGER_CST) | |
5de9d3ed | 451 | return (wi::bit_and_not (wi::to_widest (old_val.value), new_val.mask) |
452 | == wi::bit_and_not (wi::to_widest (new_val.value), new_val.mask)); | |
b7e55469 | 453 | |
454 | /* Otherwise constant values have to agree. */ | |
0001b944 | 455 | if (operand_equal_p (old_val.value, new_val.value, 0)) |
456 | return true; | |
457 | ||
458 | /* At least the kinds and types should agree now. */ | |
459 | if (TREE_CODE (old_val.value) != TREE_CODE (new_val.value) | |
460 | || !types_compatible_p (TREE_TYPE (old_val.value), | |
461 | TREE_TYPE (new_val.value))) | |
462 | return false; | |
463 | ||
464 | /* For floats and !HONOR_NANS allow transitions from (partial) NaN | |
465 | to non-NaN. */ | |
466 | tree type = TREE_TYPE (new_val.value); | |
467 | if (SCALAR_FLOAT_TYPE_P (type) | |
93633022 | 468 | && !HONOR_NANS (type)) |
0001b944 | 469 | { |
470 | if (REAL_VALUE_ISNAN (TREE_REAL_CST (old_val.value))) | |
471 | return true; | |
472 | } | |
473 | else if (VECTOR_FLOAT_TYPE_P (type) | |
93633022 | 474 | && !HONOR_NANS (type)) |
0001b944 | 475 | { |
476 | for (unsigned i = 0; i < VECTOR_CST_NELTS (old_val.value); ++i) | |
477 | if (!REAL_VALUE_ISNAN | |
478 | (TREE_REAL_CST (VECTOR_CST_ELT (old_val.value, i))) | |
479 | && !operand_equal_p (VECTOR_CST_ELT (old_val.value, i), | |
480 | VECTOR_CST_ELT (new_val.value, i), 0)) | |
481 | return false; | |
482 | return true; | |
483 | } | |
484 | else if (COMPLEX_FLOAT_TYPE_P (type) | |
93633022 | 485 | && !HONOR_NANS (type)) |
0001b944 | 486 | { |
487 | if (!REAL_VALUE_ISNAN (TREE_REAL_CST (TREE_REALPART (old_val.value))) | |
488 | && !operand_equal_p (TREE_REALPART (old_val.value), | |
489 | TREE_REALPART (new_val.value), 0)) | |
490 | return false; | |
491 | if (!REAL_VALUE_ISNAN (TREE_REAL_CST (TREE_IMAGPART (old_val.value))) | |
492 | && !operand_equal_p (TREE_IMAGPART (old_val.value), | |
493 | TREE_IMAGPART (new_val.value), 0)) | |
494 | return false; | |
495 | return true; | |
496 | } | |
497 | return false; | |
b7e55469 | 498 | } |
499 | ||
88dbf20f | 500 | /* Set the value for variable VAR to NEW_VAL. Return true if the new |
501 | value is different from VAR's previous value. */ | |
4ee9c684 | 502 | |
41511585 | 503 | static bool |
9908fe4d | 504 | set_lattice_value (tree var, ccp_prop_value_t new_val) |
4ee9c684 | 505 | { |
6d0bf6d6 | 506 | /* We can deal with old UNINITIALIZED values just fine here. */ |
9908fe4d | 507 | ccp_prop_value_t *old_val = &const_val[SSA_NAME_VERSION (var)]; |
88dbf20f | 508 | |
f5faab84 | 509 | canonicalize_value (&new_val); |
b31eb493 | 510 | |
b7e55469 | 511 | /* We have to be careful to not go up the bitwise lattice |
512 | represented by the mask. | |
513 | ??? This doesn't seem to be the best place to enforce this. */ | |
514 | if (new_val.lattice_val == CONSTANT | |
515 | && old_val->lattice_val == CONSTANT | |
516 | && TREE_CODE (new_val.value) == INTEGER_CST | |
517 | && TREE_CODE (old_val->value) == INTEGER_CST) | |
518 | { | |
5de9d3ed | 519 | widest_int diff = (wi::to_widest (new_val.value) |
520 | ^ wi::to_widest (old_val->value)); | |
cf8f0e63 | 521 | new_val.mask = new_val.mask | old_val->mask | diff; |
b7e55469 | 522 | } |
bfa30570 | 523 | |
0001b944 | 524 | gcc_checking_assert (valid_lattice_transition (*old_val, new_val)); |
88dbf20f | 525 | |
b7e55469 | 526 | /* If *OLD_VAL and NEW_VAL are the same, return false to inform the |
527 | caller that this was a non-transition. */ | |
528 | if (old_val->lattice_val != new_val.lattice_val | |
529 | || (new_val.lattice_val == CONSTANT | |
530 | && TREE_CODE (new_val.value) == INTEGER_CST | |
531 | && (TREE_CODE (old_val->value) != INTEGER_CST | |
3a54beaf | 532 | || new_val.mask != old_val->mask))) |
4ee9c684 | 533 | { |
b7e55469 | 534 | /* ??? We would like to delay creation of INTEGER_CSTs from |
535 | partially constants here. */ | |
536 | ||
41511585 | 537 | if (dump_file && (dump_flags & TDF_DETAILS)) |
538 | { | |
88dbf20f | 539 | dump_lattice_value (dump_file, "Lattice value changed to ", new_val); |
bfa30570 | 540 | fprintf (dump_file, ". Adding SSA edges to worklist.\n"); |
41511585 | 541 | } |
542 | ||
88dbf20f | 543 | *old_val = new_val; |
544 | ||
6d0bf6d6 | 545 | gcc_assert (new_val.lattice_val != UNINITIALIZED); |
bfa30570 | 546 | return true; |
4ee9c684 | 547 | } |
41511585 | 548 | |
549 | return false; | |
4ee9c684 | 550 | } |
551 | ||
9908fe4d | 552 | static ccp_prop_value_t get_value_for_expr (tree, bool); |
553 | static ccp_prop_value_t bit_value_binop (enum tree_code, tree, tree, tree); | |
5de9d3ed | 554 | static void bit_value_binop_1 (enum tree_code, tree, widest_int *, widest_int *, |
10c3fe8d | 555 | tree, const widest_int &, const widest_int &, |
556 | tree, const widest_int &, const widest_int &); | |
b7e55469 | 557 | |
5de9d3ed | 558 | /* Return a widest_int that can be used for bitwise simplifications |
b7e55469 | 559 | from VAL. */ |
560 | ||
5de9d3ed | 561 | static widest_int |
9908fe4d | 562 | value_to_wide_int (ccp_prop_value_t val) |
b7e55469 | 563 | { |
564 | if (val.value | |
565 | && TREE_CODE (val.value) == INTEGER_CST) | |
5de9d3ed | 566 | return wi::to_widest (val.value); |
e913b5cd | 567 | |
568 | return 0; | |
b7e55469 | 569 | } |
570 | ||
571 | /* Return the value for the address expression EXPR based on alignment | |
572 | information. */ | |
6d0bf6d6 | 573 | |
9908fe4d | 574 | static ccp_prop_value_t |
b7e55469 | 575 | get_value_from_alignment (tree expr) |
576 | { | |
f8abb542 | 577 | tree type = TREE_TYPE (expr); |
9908fe4d | 578 | ccp_prop_value_t val; |
f8abb542 | 579 | unsigned HOST_WIDE_INT bitpos; |
580 | unsigned int align; | |
b7e55469 | 581 | |
582 | gcc_assert (TREE_CODE (expr) == ADDR_EXPR); | |
583 | ||
59da1bcd | 584 | get_pointer_alignment_1 (expr, &align, &bitpos); |
cf8f0e63 | 585 | val.mask = (POINTER_TYPE_P (type) || TYPE_UNSIGNED (type) |
5de9d3ed | 586 | ? wi::mask <widest_int> (TYPE_PRECISION (type), false) |
e913b5cd | 587 | : -1).and_not (align / BITS_PER_UNIT - 1); |
c90d2c17 | 588 | val.lattice_val |
589 | = wi::sext (val.mask, TYPE_PRECISION (type)) == -1 ? VARYING : CONSTANT; | |
f8abb542 | 590 | if (val.lattice_val == CONSTANT) |
796b6678 | 591 | val.value = build_int_cstu (type, bitpos / BITS_PER_UNIT); |
b7e55469 | 592 | else |
f8abb542 | 593 | val.value = NULL_TREE; |
b7e55469 | 594 | |
595 | return val; | |
596 | } | |
597 | ||
598 | /* Return the value for the tree operand EXPR. If FOR_BITS_P is true | |
599 | return constant bits extracted from alignment information for | |
600 | invariant addresses. */ | |
601 | ||
9908fe4d | 602 | static ccp_prop_value_t |
b7e55469 | 603 | get_value_for_expr (tree expr, bool for_bits_p) |
6d0bf6d6 | 604 | { |
9908fe4d | 605 | ccp_prop_value_t val; |
6d0bf6d6 | 606 | |
607 | if (TREE_CODE (expr) == SSA_NAME) | |
b7e55469 | 608 | { |
609 | val = *get_value (expr); | |
610 | if (for_bits_p | |
611 | && val.lattice_val == CONSTANT | |
612 | && TREE_CODE (val.value) == ADDR_EXPR) | |
613 | val = get_value_from_alignment (val.value); | |
614 | } | |
615 | else if (is_gimple_min_invariant (expr) | |
616 | && (!for_bits_p || TREE_CODE (expr) != ADDR_EXPR)) | |
6d0bf6d6 | 617 | { |
618 | val.lattice_val = CONSTANT; | |
619 | val.value = expr; | |
e913b5cd | 620 | val.mask = 0; |
f5faab84 | 621 | canonicalize_value (&val); |
6d0bf6d6 | 622 | } |
b7e55469 | 623 | else if (TREE_CODE (expr) == ADDR_EXPR) |
624 | val = get_value_from_alignment (expr); | |
6d0bf6d6 | 625 | else |
626 | { | |
627 | val.lattice_val = VARYING; | |
09b2913a | 628 | val.mask = -1; |
6d0bf6d6 | 629 | val.value = NULL_TREE; |
630 | } | |
6d0bf6d6 | 631 | return val; |
632 | } | |
633 | ||
88dbf20f | 634 | /* Return the likely CCP lattice value for STMT. |
4ee9c684 | 635 | |
41511585 | 636 | If STMT has no operands, then return CONSTANT. |
4ee9c684 | 637 | |
d61b9af3 | 638 | Else if undefinedness of operands of STMT cause its value to be |
639 | undefined, then return UNDEFINED. | |
4ee9c684 | 640 | |
41511585 | 641 | Else if any operands of STMT are constants, then return CONSTANT. |
4ee9c684 | 642 | |
41511585 | 643 | Else return VARYING. */ |
4ee9c684 | 644 | |
88dbf20f | 645 | static ccp_lattice_t |
75a70cf9 | 646 | likely_value (gimple stmt) |
41511585 | 647 | { |
d61b9af3 | 648 | bool has_constant_operand, has_undefined_operand, all_undefined_operands; |
a8a0d56e | 649 | bool has_nsa_operand; |
41511585 | 650 | tree use; |
651 | ssa_op_iter iter; | |
8edeb88b | 652 | unsigned i; |
4ee9c684 | 653 | |
590c3166 | 654 | enum gimple_code code = gimple_code (stmt); |
75a70cf9 | 655 | |
656 | /* This function appears to be called only for assignments, calls, | |
657 | conditionals, and switches, due to the logic in visit_stmt. */ | |
658 | gcc_assert (code == GIMPLE_ASSIGN | |
659 | || code == GIMPLE_CALL | |
660 | || code == GIMPLE_COND | |
661 | || code == GIMPLE_SWITCH); | |
88dbf20f | 662 | |
663 | /* If the statement has volatile operands, it won't fold to a | |
664 | constant value. */ | |
75a70cf9 | 665 | if (gimple_has_volatile_ops (stmt)) |
88dbf20f | 666 | return VARYING; |
667 | ||
75a70cf9 | 668 | /* Arrive here for more complex cases. */ |
bfa30570 | 669 | has_constant_operand = false; |
d61b9af3 | 670 | has_undefined_operand = false; |
671 | all_undefined_operands = true; | |
a8a0d56e | 672 | has_nsa_operand = false; |
8edeb88b | 673 | FOR_EACH_SSA_TREE_OPERAND (use, stmt, iter, SSA_OP_USE) |
41511585 | 674 | { |
9908fe4d | 675 | ccp_prop_value_t *val = get_value (use); |
41511585 | 676 | |
bfa30570 | 677 | if (val->lattice_val == UNDEFINED) |
d61b9af3 | 678 | has_undefined_operand = true; |
679 | else | |
680 | all_undefined_operands = false; | |
88dbf20f | 681 | |
41511585 | 682 | if (val->lattice_val == CONSTANT) |
bfa30570 | 683 | has_constant_operand = true; |
a8a0d56e | 684 | |
685 | if (SSA_NAME_IS_DEFAULT_DEF (use) | |
686 | || !prop_simulate_again_p (SSA_NAME_DEF_STMT (use))) | |
687 | has_nsa_operand = true; | |
4ee9c684 | 688 | } |
41511585 | 689 | |
dd277d48 | 690 | /* There may be constants in regular rhs operands. For calls we |
691 | have to ignore lhs, fndecl and static chain, otherwise only | |
692 | the lhs. */ | |
693 | for (i = (is_gimple_call (stmt) ? 2 : 0) + gimple_has_lhs (stmt); | |
8edeb88b | 694 | i < gimple_num_ops (stmt); ++i) |
695 | { | |
696 | tree op = gimple_op (stmt, i); | |
697 | if (!op || TREE_CODE (op) == SSA_NAME) | |
698 | continue; | |
699 | if (is_gimple_min_invariant (op)) | |
700 | has_constant_operand = true; | |
701 | } | |
702 | ||
87c0a9fc | 703 | if (has_constant_operand) |
704 | all_undefined_operands = false; | |
705 | ||
3d483a94 | 706 | if (has_undefined_operand |
707 | && code == GIMPLE_CALL | |
708 | && gimple_call_internal_p (stmt)) | |
709 | switch (gimple_call_internal_fn (stmt)) | |
710 | { | |
711 | /* These 3 builtins use the first argument just as a magic | |
712 | way how to find out a decl uid. */ | |
713 | case IFN_GOMP_SIMD_LANE: | |
714 | case IFN_GOMP_SIMD_VF: | |
715 | case IFN_GOMP_SIMD_LAST_LANE: | |
716 | has_undefined_operand = false; | |
717 | break; | |
718 | default: | |
719 | break; | |
720 | } | |
721 | ||
d61b9af3 | 722 | /* If the operation combines operands like COMPLEX_EXPR make sure to |
723 | not mark the result UNDEFINED if only one part of the result is | |
724 | undefined. */ | |
75a70cf9 | 725 | if (has_undefined_operand && all_undefined_operands) |
d61b9af3 | 726 | return UNDEFINED; |
75a70cf9 | 727 | else if (code == GIMPLE_ASSIGN && has_undefined_operand) |
d61b9af3 | 728 | { |
75a70cf9 | 729 | switch (gimple_assign_rhs_code (stmt)) |
d61b9af3 | 730 | { |
731 | /* Unary operators are handled with all_undefined_operands. */ | |
732 | case PLUS_EXPR: | |
733 | case MINUS_EXPR: | |
d61b9af3 | 734 | case POINTER_PLUS_EXPR: |
d61b9af3 | 735 | /* Not MIN_EXPR, MAX_EXPR. One VARYING operand may be selected. |
736 | Not bitwise operators, one VARYING operand may specify the | |
737 | result completely. Not logical operators for the same reason. | |
05a936a0 | 738 | Not COMPLEX_EXPR as one VARYING operand makes the result partly |
739 | not UNDEFINED. Not *DIV_EXPR, comparisons and shifts because | |
740 | the undefined operand may be promoted. */ | |
d61b9af3 | 741 | return UNDEFINED; |
742 | ||
43c92e0a | 743 | case ADDR_EXPR: |
744 | /* If any part of an address is UNDEFINED, like the index | |
745 | of an ARRAY_EXPR, then treat the result as UNDEFINED. */ | |
746 | return UNDEFINED; | |
747 | ||
d61b9af3 | 748 | default: |
749 | ; | |
750 | } | |
751 | } | |
752 | /* If there was an UNDEFINED operand but the result may be not UNDEFINED | |
c91fedc5 | 753 | fall back to CONSTANT. During iteration UNDEFINED may still drop |
754 | to CONSTANT. */ | |
d61b9af3 | 755 | if (has_undefined_operand) |
c91fedc5 | 756 | return CONSTANT; |
d61b9af3 | 757 | |
8edeb88b | 758 | /* We do not consider virtual operands here -- load from read-only |
759 | memory may have only VARYING virtual operands, but still be | |
a8a0d56e | 760 | constant. Also we can combine the stmt with definitions from |
761 | operands whose definitions are not simulated again. */ | |
bfa30570 | 762 | if (has_constant_operand |
a8a0d56e | 763 | || has_nsa_operand |
8edeb88b | 764 | || gimple_references_memory_p (stmt)) |
88dbf20f | 765 | return CONSTANT; |
766 | ||
bfa30570 | 767 | return VARYING; |
4ee9c684 | 768 | } |
769 | ||
bfa30570 | 770 | /* Returns true if STMT cannot be constant. */ |
771 | ||
772 | static bool | |
75a70cf9 | 773 | surely_varying_stmt_p (gimple stmt) |
bfa30570 | 774 | { |
775 | /* If the statement has operands that we cannot handle, it cannot be | |
776 | constant. */ | |
75a70cf9 | 777 | if (gimple_has_volatile_ops (stmt)) |
bfa30570 | 778 | return true; |
779 | ||
f257af64 | 780 | /* If it is a call and does not return a value or is not a |
237e78b1 | 781 | builtin and not an indirect call or a call to function with |
782 | assume_aligned/alloc_align attribute, it is varying. */ | |
75a70cf9 | 783 | if (is_gimple_call (stmt)) |
f257af64 | 784 | { |
237e78b1 | 785 | tree fndecl, fntype = gimple_call_fntype (stmt); |
f257af64 | 786 | if (!gimple_call_lhs (stmt) |
787 | || ((fndecl = gimple_call_fndecl (stmt)) != NULL_TREE | |
237e78b1 | 788 | && !DECL_BUILT_IN (fndecl) |
789 | && !lookup_attribute ("assume_aligned", | |
790 | TYPE_ATTRIBUTES (fntype)) | |
791 | && !lookup_attribute ("alloc_align", | |
792 | TYPE_ATTRIBUTES (fntype)))) | |
f257af64 | 793 | return true; |
794 | } | |
bfa30570 | 795 | |
8edeb88b | 796 | /* Any other store operation is not interesting. */ |
dd277d48 | 797 | else if (gimple_vdef (stmt)) |
8edeb88b | 798 | return true; |
799 | ||
bfa30570 | 800 | /* Anything other than assignments and conditional jumps are not |
801 | interesting for CCP. */ | |
75a70cf9 | 802 | if (gimple_code (stmt) != GIMPLE_ASSIGN |
f257af64 | 803 | && gimple_code (stmt) != GIMPLE_COND |
804 | && gimple_code (stmt) != GIMPLE_SWITCH | |
805 | && gimple_code (stmt) != GIMPLE_CALL) | |
bfa30570 | 806 | return true; |
807 | ||
808 | return false; | |
809 | } | |
4ee9c684 | 810 | |
41511585 | 811 | /* Initialize local data structures for CCP. */ |
4ee9c684 | 812 | |
813 | static void | |
41511585 | 814 | ccp_initialize (void) |
4ee9c684 | 815 | { |
41511585 | 816 | basic_block bb; |
4ee9c684 | 817 | |
285df01b | 818 | n_const_val = num_ssa_names; |
9908fe4d | 819 | const_val = XCNEWVEC (ccp_prop_value_t, n_const_val); |
4ee9c684 | 820 | |
41511585 | 821 | /* Initialize simulation flags for PHI nodes and statements. */ |
fc00614f | 822 | FOR_EACH_BB_FN (bb, cfun) |
4ee9c684 | 823 | { |
75a70cf9 | 824 | gimple_stmt_iterator i; |
4ee9c684 | 825 | |
75a70cf9 | 826 | for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i)) |
41511585 | 827 | { |
75a70cf9 | 828 | gimple stmt = gsi_stmt (i); |
2193544e | 829 | bool is_varying; |
830 | ||
831 | /* If the statement is a control insn, then we do not | |
832 | want to avoid simulating the statement once. Failure | |
833 | to do so means that those edges will never get added. */ | |
834 | if (stmt_ends_bb_p (stmt)) | |
835 | is_varying = false; | |
836 | else | |
837 | is_varying = surely_varying_stmt_p (stmt); | |
4ee9c684 | 838 | |
bfa30570 | 839 | if (is_varying) |
41511585 | 840 | { |
88dbf20f | 841 | tree def; |
842 | ssa_op_iter iter; | |
843 | ||
844 | /* If the statement will not produce a constant, mark | |
845 | all its outputs VARYING. */ | |
846 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS) | |
8edeb88b | 847 | set_value_varying (def); |
41511585 | 848 | } |
75a70cf9 | 849 | prop_set_simulate_again (stmt, !is_varying); |
41511585 | 850 | } |
4ee9c684 | 851 | } |
852 | ||
75a70cf9 | 853 | /* Now process PHI nodes. We never clear the simulate_again flag on |
854 | phi nodes, since we do not know which edges are executable yet, | |
855 | except for phi nodes for virtual operands when we do not do store ccp. */ | |
fc00614f | 856 | FOR_EACH_BB_FN (bb, cfun) |
4ee9c684 | 857 | { |
1a91d914 | 858 | gphi_iterator i; |
41511585 | 859 | |
75a70cf9 | 860 | for (i = gsi_start_phis (bb); !gsi_end_p (i); gsi_next (&i)) |
861 | { | |
1a91d914 | 862 | gphi *phi = i.phi (); |
75a70cf9 | 863 | |
7c782c9b | 864 | if (virtual_operand_p (gimple_phi_result (phi))) |
75a70cf9 | 865 | prop_set_simulate_again (phi, false); |
bfa30570 | 866 | else |
75a70cf9 | 867 | prop_set_simulate_again (phi, true); |
41511585 | 868 | } |
4ee9c684 | 869 | } |
41511585 | 870 | } |
4ee9c684 | 871 | |
43fb76c1 | 872 | /* Debug count support. Reset the values of ssa names |
873 | VARYING when the total number ssa names analyzed is | |
874 | beyond the debug count specified. */ | |
875 | ||
876 | static void | |
877 | do_dbg_cnt (void) | |
878 | { | |
879 | unsigned i; | |
880 | for (i = 0; i < num_ssa_names; i++) | |
881 | { | |
882 | if (!dbg_cnt (ccp)) | |
883 | { | |
884 | const_val[i].lattice_val = VARYING; | |
e913b5cd | 885 | const_val[i].mask = -1; |
43fb76c1 | 886 | const_val[i].value = NULL_TREE; |
887 | } | |
888 | } | |
889 | } | |
890 | ||
4ee9c684 | 891 | |
88dbf20f | 892 | /* Do final substitution of propagated values, cleanup the flowgraph and |
48e1416a | 893 | free allocated storage. |
4ee9c684 | 894 | |
33a34f1e | 895 | Return TRUE when something was optimized. */ |
896 | ||
897 | static bool | |
88dbf20f | 898 | ccp_finalize (void) |
4ee9c684 | 899 | { |
43fb76c1 | 900 | bool something_changed; |
153c3b50 | 901 | unsigned i; |
43fb76c1 | 902 | |
903 | do_dbg_cnt (); | |
153c3b50 | 904 | |
905 | /* Derive alignment and misalignment information from partially | |
fc08b993 | 906 | constant pointers in the lattice or nonzero bits from partially |
907 | constant integers. */ | |
153c3b50 | 908 | for (i = 1; i < num_ssa_names; ++i) |
909 | { | |
910 | tree name = ssa_name (i); | |
9908fe4d | 911 | ccp_prop_value_t *val; |
153c3b50 | 912 | unsigned int tem, align; |
913 | ||
914 | if (!name | |
fc08b993 | 915 | || (!POINTER_TYPE_P (TREE_TYPE (name)) |
916 | && (!INTEGRAL_TYPE_P (TREE_TYPE (name)) | |
917 | /* Don't record nonzero bits before IPA to avoid | |
918 | using too much memory. */ | |
919 | || first_pass_instance))) | |
153c3b50 | 920 | continue; |
921 | ||
922 | val = get_value (name); | |
923 | if (val->lattice_val != CONSTANT | |
924 | || TREE_CODE (val->value) != INTEGER_CST) | |
925 | continue; | |
926 | ||
fc08b993 | 927 | if (POINTER_TYPE_P (TREE_TYPE (name))) |
928 | { | |
929 | /* Trailing mask bits specify the alignment, trailing value | |
930 | bits the misalignment. */ | |
aeb682a2 | 931 | tem = val->mask.to_uhwi (); |
fc08b993 | 932 | align = (tem & -tem); |
933 | if (align > 1) | |
934 | set_ptr_info_alignment (get_ptr_info (name), align, | |
f9ae6f95 | 935 | (TREE_INT_CST_LOW (val->value) |
fc08b993 | 936 | & (align - 1))); |
937 | } | |
938 | else | |
939 | { | |
9c1be15e | 940 | unsigned int precision = TYPE_PRECISION (TREE_TYPE (val->value)); |
941 | wide_int nonzero_bits = wide_int::from (val->mask, precision, | |
942 | UNSIGNED) | val->value; | |
fc08b993 | 943 | nonzero_bits &= get_nonzero_bits (name); |
944 | set_nonzero_bits (name, nonzero_bits); | |
945 | } | |
153c3b50 | 946 | } |
947 | ||
88dbf20f | 948 | /* Perform substitutions based on the known constant values. */ |
14f101cf | 949 | something_changed = substitute_and_fold (get_constant_value, |
950 | ccp_fold_stmt, true); | |
4ee9c684 | 951 | |
88dbf20f | 952 | free (const_val); |
e004838d | 953 | const_val = NULL; |
33a34f1e | 954 | return something_changed;; |
4ee9c684 | 955 | } |
956 | ||
957 | ||
88dbf20f | 958 | /* Compute the meet operator between *VAL1 and *VAL2. Store the result |
959 | in VAL1. | |
960 | ||
961 | any M UNDEFINED = any | |
88dbf20f | 962 | any M VARYING = VARYING |
963 | Ci M Cj = Ci if (i == j) | |
964 | Ci M Cj = VARYING if (i != j) | |
bfa30570 | 965 | */ |
4ee9c684 | 966 | |
967 | static void | |
9908fe4d | 968 | ccp_lattice_meet (ccp_prop_value_t *val1, ccp_prop_value_t *val2) |
4ee9c684 | 969 | { |
88dbf20f | 970 | if (val1->lattice_val == UNDEFINED) |
4ee9c684 | 971 | { |
88dbf20f | 972 | /* UNDEFINED M any = any */ |
973 | *val1 = *val2; | |
41511585 | 974 | } |
88dbf20f | 975 | else if (val2->lattice_val == UNDEFINED) |
92481a4d | 976 | { |
88dbf20f | 977 | /* any M UNDEFINED = any |
978 | Nothing to do. VAL1 already contains the value we want. */ | |
979 | ; | |
92481a4d | 980 | } |
88dbf20f | 981 | else if (val1->lattice_val == VARYING |
982 | || val2->lattice_val == VARYING) | |
41511585 | 983 | { |
88dbf20f | 984 | /* any M VARYING = VARYING. */ |
985 | val1->lattice_val = VARYING; | |
e913b5cd | 986 | val1->mask = -1; |
88dbf20f | 987 | val1->value = NULL_TREE; |
41511585 | 988 | } |
b7e55469 | 989 | else if (val1->lattice_val == CONSTANT |
990 | && val2->lattice_val == CONSTANT | |
991 | && TREE_CODE (val1->value) == INTEGER_CST | |
992 | && TREE_CODE (val2->value) == INTEGER_CST) | |
993 | { | |
994 | /* Ci M Cj = Ci if (i == j) | |
995 | Ci M Cj = VARYING if (i != j) | |
996 | ||
997 | For INTEGER_CSTs mask unequal bits. If no equal bits remain, | |
998 | drop to varying. */ | |
e913b5cd | 999 | val1->mask = (val1->mask | val2->mask |
5de9d3ed | 1000 | | (wi::to_widest (val1->value) |
1001 | ^ wi::to_widest (val2->value))); | |
c90d2c17 | 1002 | if (wi::sext (val1->mask, TYPE_PRECISION (TREE_TYPE (val1->value))) == -1) |
b7e55469 | 1003 | { |
1004 | val1->lattice_val = VARYING; | |
1005 | val1->value = NULL_TREE; | |
1006 | } | |
1007 | } | |
88dbf20f | 1008 | else if (val1->lattice_val == CONSTANT |
1009 | && val2->lattice_val == CONSTANT | |
61207d43 | 1010 | && simple_cst_equal (val1->value, val2->value) == 1) |
41511585 | 1011 | { |
88dbf20f | 1012 | /* Ci M Cj = Ci if (i == j) |
1013 | Ci M Cj = VARYING if (i != j) | |
1014 | ||
b7e55469 | 1015 | VAL1 already contains the value we want for equivalent values. */ |
1016 | } | |
1017 | else if (val1->lattice_val == CONSTANT | |
1018 | && val2->lattice_val == CONSTANT | |
1019 | && (TREE_CODE (val1->value) == ADDR_EXPR | |
1020 | || TREE_CODE (val2->value) == ADDR_EXPR)) | |
1021 | { | |
1022 | /* When not equal addresses are involved try meeting for | |
1023 | alignment. */ | |
9908fe4d | 1024 | ccp_prop_value_t tem = *val2; |
b7e55469 | 1025 | if (TREE_CODE (val1->value) == ADDR_EXPR) |
1026 | *val1 = get_value_for_expr (val1->value, true); | |
1027 | if (TREE_CODE (val2->value) == ADDR_EXPR) | |
1028 | tem = get_value_for_expr (val2->value, true); | |
1029 | ccp_lattice_meet (val1, &tem); | |
41511585 | 1030 | } |
1031 | else | |
1032 | { | |
88dbf20f | 1033 | /* Any other combination is VARYING. */ |
1034 | val1->lattice_val = VARYING; | |
e913b5cd | 1035 | val1->mask = -1; |
88dbf20f | 1036 | val1->value = NULL_TREE; |
41511585 | 1037 | } |
4ee9c684 | 1038 | } |
1039 | ||
1040 | ||
41511585 | 1041 | /* Loop through the PHI_NODE's parameters for BLOCK and compare their |
1042 | lattice values to determine PHI_NODE's lattice value. The value of a | |
88dbf20f | 1043 | PHI node is determined calling ccp_lattice_meet with all the arguments |
41511585 | 1044 | of the PHI node that are incoming via executable edges. */ |
4ee9c684 | 1045 | |
41511585 | 1046 | static enum ssa_prop_result |
1a91d914 | 1047 | ccp_visit_phi_node (gphi *phi) |
4ee9c684 | 1048 | { |
75a70cf9 | 1049 | unsigned i; |
9908fe4d | 1050 | ccp_prop_value_t *old_val, new_val; |
4ee9c684 | 1051 | |
41511585 | 1052 | if (dump_file && (dump_flags & TDF_DETAILS)) |
4ee9c684 | 1053 | { |
41511585 | 1054 | fprintf (dump_file, "\nVisiting PHI node: "); |
75a70cf9 | 1055 | print_gimple_stmt (dump_file, phi, 0, dump_flags); |
4ee9c684 | 1056 | } |
4ee9c684 | 1057 | |
75a70cf9 | 1058 | old_val = get_value (gimple_phi_result (phi)); |
41511585 | 1059 | switch (old_val->lattice_val) |
1060 | { | |
1061 | case VARYING: | |
88dbf20f | 1062 | return SSA_PROP_VARYING; |
4ee9c684 | 1063 | |
41511585 | 1064 | case CONSTANT: |
1065 | new_val = *old_val; | |
1066 | break; | |
4ee9c684 | 1067 | |
41511585 | 1068 | case UNDEFINED: |
41511585 | 1069 | new_val.lattice_val = UNDEFINED; |
88dbf20f | 1070 | new_val.value = NULL_TREE; |
41511585 | 1071 | break; |
4ee9c684 | 1072 | |
41511585 | 1073 | default: |
8c0963c4 | 1074 | gcc_unreachable (); |
41511585 | 1075 | } |
4ee9c684 | 1076 | |
75a70cf9 | 1077 | for (i = 0; i < gimple_phi_num_args (phi); i++) |
41511585 | 1078 | { |
88dbf20f | 1079 | /* Compute the meet operator over all the PHI arguments flowing |
1080 | through executable edges. */ | |
75a70cf9 | 1081 | edge e = gimple_phi_arg_edge (phi, i); |
4ee9c684 | 1082 | |
41511585 | 1083 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1084 | { | |
1085 | fprintf (dump_file, | |
1086 | "\n Argument #%d (%d -> %d %sexecutable)\n", | |
1087 | i, e->src->index, e->dest->index, | |
1088 | (e->flags & EDGE_EXECUTABLE) ? "" : "not "); | |
1089 | } | |
1090 | ||
1091 | /* If the incoming edge is executable, Compute the meet operator for | |
1092 | the existing value of the PHI node and the current PHI argument. */ | |
1093 | if (e->flags & EDGE_EXECUTABLE) | |
1094 | { | |
75a70cf9 | 1095 | tree arg = gimple_phi_arg (phi, i)->def; |
9908fe4d | 1096 | ccp_prop_value_t arg_val = get_value_for_expr (arg, false); |
4ee9c684 | 1097 | |
88dbf20f | 1098 | ccp_lattice_meet (&new_val, &arg_val); |
4ee9c684 | 1099 | |
41511585 | 1100 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1101 | { | |
1102 | fprintf (dump_file, "\t"); | |
88dbf20f | 1103 | print_generic_expr (dump_file, arg, dump_flags); |
1104 | dump_lattice_value (dump_file, "\tValue: ", arg_val); | |
41511585 | 1105 | fprintf (dump_file, "\n"); |
1106 | } | |
4ee9c684 | 1107 | |
41511585 | 1108 | if (new_val.lattice_val == VARYING) |
1109 | break; | |
1110 | } | |
1111 | } | |
4ee9c684 | 1112 | |
1113 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
41511585 | 1114 | { |
1115 | dump_lattice_value (dump_file, "\n PHI node value: ", new_val); | |
1116 | fprintf (dump_file, "\n\n"); | |
1117 | } | |
1118 | ||
bfa30570 | 1119 | /* Make the transition to the new value. */ |
75a70cf9 | 1120 | if (set_lattice_value (gimple_phi_result (phi), new_val)) |
41511585 | 1121 | { |
1122 | if (new_val.lattice_val == VARYING) | |
1123 | return SSA_PROP_VARYING; | |
1124 | else | |
1125 | return SSA_PROP_INTERESTING; | |
1126 | } | |
1127 | else | |
1128 | return SSA_PROP_NOT_INTERESTING; | |
4ee9c684 | 1129 | } |
1130 | ||
15d138c9 | 1131 | /* Return the constant value for OP or OP otherwise. */ |
00f4f705 | 1132 | |
1133 | static tree | |
15d138c9 | 1134 | valueize_op (tree op) |
00f4f705 | 1135 | { |
00f4f705 | 1136 | if (TREE_CODE (op) == SSA_NAME) |
1137 | { | |
15d138c9 | 1138 | tree tem = get_constant_value (op); |
1139 | if (tem) | |
1140 | return tem; | |
00f4f705 | 1141 | } |
1142 | return op; | |
1143 | } | |
1144 | ||
4e1b3545 | 1145 | /* Return the constant value for OP, but signal to not follow SSA |
1146 | edges if the definition may be simulated again. */ | |
1147 | ||
1148 | static tree | |
1149 | valueize_op_1 (tree op) | |
1150 | { | |
1151 | if (TREE_CODE (op) == SSA_NAME) | |
1152 | { | |
4e1b3545 | 1153 | /* If the definition may be simulated again we cannot follow |
1154 | this SSA edge as the SSA propagator does not necessarily | |
1155 | re-visit the use. */ | |
1156 | gimple def_stmt = SSA_NAME_DEF_STMT (op); | |
2160d5ba | 1157 | if (!gimple_nop_p (def_stmt) |
1158 | && prop_simulate_again_p (def_stmt)) | |
4e1b3545 | 1159 | return NULL_TREE; |
bc8fa068 | 1160 | tree tem = get_constant_value (op); |
1161 | if (tem) | |
1162 | return tem; | |
4e1b3545 | 1163 | } |
1164 | return op; | |
1165 | } | |
1166 | ||
41511585 | 1167 | /* CCP specific front-end to the non-destructive constant folding |
1168 | routines. | |
4ee9c684 | 1169 | |
1170 | Attempt to simplify the RHS of STMT knowing that one or more | |
1171 | operands are constants. | |
1172 | ||
1173 | If simplification is possible, return the simplified RHS, | |
75a70cf9 | 1174 | otherwise return the original RHS or NULL_TREE. */ |
4ee9c684 | 1175 | |
1176 | static tree | |
75a70cf9 | 1177 | ccp_fold (gimple stmt) |
4ee9c684 | 1178 | { |
389dd41b | 1179 | location_t loc = gimple_location (stmt); |
75a70cf9 | 1180 | switch (gimple_code (stmt)) |
88dbf20f | 1181 | { |
75a70cf9 | 1182 | case GIMPLE_COND: |
1183 | { | |
1184 | /* Handle comparison operators that can appear in GIMPLE form. */ | |
15d138c9 | 1185 | tree op0 = valueize_op (gimple_cond_lhs (stmt)); |
1186 | tree op1 = valueize_op (gimple_cond_rhs (stmt)); | |
75a70cf9 | 1187 | enum tree_code code = gimple_cond_code (stmt); |
389dd41b | 1188 | return fold_binary_loc (loc, code, boolean_type_node, op0, op1); |
75a70cf9 | 1189 | } |
4ee9c684 | 1190 | |
75a70cf9 | 1191 | case GIMPLE_SWITCH: |
1192 | { | |
15d138c9 | 1193 | /* Return the constant switch index. */ |
1a91d914 | 1194 | return valueize_op (gimple_switch_index (as_a <gswitch *> (stmt))); |
75a70cf9 | 1195 | } |
912f109f | 1196 | |
1d0b727d | 1197 | case GIMPLE_ASSIGN: |
1198 | case GIMPLE_CALL: | |
4e1b3545 | 1199 | return gimple_fold_stmt_to_constant_1 (stmt, |
1200 | valueize_op, valueize_op_1); | |
04236c3a | 1201 | |
8782adcf | 1202 | default: |
1d0b727d | 1203 | gcc_unreachable (); |
8782adcf | 1204 | } |
8782adcf | 1205 | } |
75a70cf9 | 1206 | |
b7e55469 | 1207 | /* Apply the operation CODE in type TYPE to the value, mask pair |
1208 | RVAL and RMASK representing a value of type RTYPE and set | |
1209 | the value, mask pair *VAL and *MASK to the result. */ | |
1210 | ||
1211 | static void | |
1212 | bit_value_unop_1 (enum tree_code code, tree type, | |
5de9d3ed | 1213 | widest_int *val, widest_int *mask, |
1214 | tree rtype, const widest_int &rval, const widest_int &rmask) | |
b7e55469 | 1215 | { |
1216 | switch (code) | |
1217 | { | |
1218 | case BIT_NOT_EXPR: | |
1219 | *mask = rmask; | |
cf8f0e63 | 1220 | *val = ~rval; |
b7e55469 | 1221 | break; |
1222 | ||
1223 | case NEGATE_EXPR: | |
1224 | { | |
5de9d3ed | 1225 | widest_int temv, temm; |
b7e55469 | 1226 | /* Return ~rval + 1. */ |
1227 | bit_value_unop_1 (BIT_NOT_EXPR, type, &temv, &temm, type, rval, rmask); | |
1228 | bit_value_binop_1 (PLUS_EXPR, type, val, mask, | |
e913b5cd | 1229 | type, temv, temm, type, 1, 0); |
b7e55469 | 1230 | break; |
1231 | } | |
1232 | ||
1233 | CASE_CONVERT: | |
1234 | { | |
e913b5cd | 1235 | signop sgn; |
b7e55469 | 1236 | |
1237 | /* First extend mask and value according to the original type. */ | |
e913b5cd | 1238 | sgn = TYPE_SIGN (rtype); |
796b6678 | 1239 | *mask = wi::ext (rmask, TYPE_PRECISION (rtype), sgn); |
1240 | *val = wi::ext (rval, TYPE_PRECISION (rtype), sgn); | |
b7e55469 | 1241 | |
1242 | /* Then extend mask and value according to the target type. */ | |
e913b5cd | 1243 | sgn = TYPE_SIGN (type); |
796b6678 | 1244 | *mask = wi::ext (*mask, TYPE_PRECISION (type), sgn); |
1245 | *val = wi::ext (*val, TYPE_PRECISION (type), sgn); | |
b7e55469 | 1246 | break; |
1247 | } | |
1248 | ||
1249 | default: | |
e913b5cd | 1250 | *mask = -1; |
b7e55469 | 1251 | break; |
1252 | } | |
1253 | } | |
1254 | ||
1255 | /* Apply the operation CODE in type TYPE to the value, mask pairs | |
1256 | R1VAL, R1MASK and R2VAL, R2MASK representing a values of type R1TYPE | |
1257 | and R2TYPE and set the value, mask pair *VAL and *MASK to the result. */ | |
1258 | ||
1259 | static void | |
1260 | bit_value_binop_1 (enum tree_code code, tree type, | |
5de9d3ed | 1261 | widest_int *val, widest_int *mask, |
10c3fe8d | 1262 | tree r1type, const widest_int &r1val, |
1263 | const widest_int &r1mask, tree r2type, | |
1264 | const widest_int &r2val, const widest_int &r2mask) | |
b7e55469 | 1265 | { |
e913b5cd | 1266 | signop sgn = TYPE_SIGN (type); |
1267 | int width = TYPE_PRECISION (type); | |
10c3fe8d | 1268 | bool swap_p = false; |
e913b5cd | 1269 | |
1270 | /* Assume we'll get a constant result. Use an initial non varying | |
1271 | value, we fall back to varying in the end if necessary. */ | |
1272 | *mask = -1; | |
1273 | ||
b7e55469 | 1274 | switch (code) |
1275 | { | |
1276 | case BIT_AND_EXPR: | |
1277 | /* The mask is constant where there is a known not | |
1278 | set bit, (m1 | m2) & ((v1 | m1) & (v2 | m2)) */ | |
cf8f0e63 | 1279 | *mask = (r1mask | r2mask) & (r1val | r1mask) & (r2val | r2mask); |
1280 | *val = r1val & r2val; | |
b7e55469 | 1281 | break; |
1282 | ||
1283 | case BIT_IOR_EXPR: | |
1284 | /* The mask is constant where there is a known | |
1285 | set bit, (m1 | m2) & ~((v1 & ~m1) | (v2 & ~m2)). */ | |
cf8f0e63 | 1286 | *mask = (r1mask | r2mask) |
1287 | .and_not (r1val.and_not (r1mask) | r2val.and_not (r2mask)); | |
1288 | *val = r1val | r2val; | |
b7e55469 | 1289 | break; |
1290 | ||
1291 | case BIT_XOR_EXPR: | |
1292 | /* m1 | m2 */ | |
cf8f0e63 | 1293 | *mask = r1mask | r2mask; |
1294 | *val = r1val ^ r2val; | |
b7e55469 | 1295 | break; |
1296 | ||
1297 | case LROTATE_EXPR: | |
1298 | case RROTATE_EXPR: | |
796b6678 | 1299 | if (r2mask == 0) |
b7e55469 | 1300 | { |
28e557ef | 1301 | widest_int shift = r2val; |
796b6678 | 1302 | if (shift == 0) |
e913b5cd | 1303 | { |
1304 | *mask = r1mask; | |
1305 | *val = r1val; | |
1306 | } | |
ddb1be65 | 1307 | else |
e913b5cd | 1308 | { |
796b6678 | 1309 | if (wi::neg_p (shift)) |
e913b5cd | 1310 | { |
1311 | shift = -shift; | |
1312 | if (code == RROTATE_EXPR) | |
1313 | code = LROTATE_EXPR; | |
1314 | else | |
1315 | code = RROTATE_EXPR; | |
1316 | } | |
1317 | if (code == RROTATE_EXPR) | |
1318 | { | |
796b6678 | 1319 | *mask = wi::rrotate (r1mask, shift, width); |
1320 | *val = wi::rrotate (r1val, shift, width); | |
e913b5cd | 1321 | } |
1322 | else | |
1323 | { | |
796b6678 | 1324 | *mask = wi::lrotate (r1mask, shift, width); |
1325 | *val = wi::lrotate (r1val, shift, width); | |
e913b5cd | 1326 | } |
1327 | } | |
b7e55469 | 1328 | } |
1329 | break; | |
1330 | ||
1331 | case LSHIFT_EXPR: | |
1332 | case RSHIFT_EXPR: | |
1333 | /* ??? We can handle partially known shift counts if we know | |
1334 | its sign. That way we can tell that (x << (y | 8)) & 255 | |
1335 | is zero. */ | |
796b6678 | 1336 | if (r2mask == 0) |
b7e55469 | 1337 | { |
28e557ef | 1338 | widest_int shift = r2val; |
796b6678 | 1339 | if (shift == 0) |
b7e55469 | 1340 | { |
1341 | *mask = r1mask; | |
1342 | *val = r1val; | |
1343 | } | |
ddb1be65 | 1344 | else |
e913b5cd | 1345 | { |
796b6678 | 1346 | if (wi::neg_p (shift)) |
e913b5cd | 1347 | { |
1348 | shift = -shift; | |
1349 | if (code == RSHIFT_EXPR) | |
1350 | code = LSHIFT_EXPR; | |
1351 | else | |
1352 | code = RSHIFT_EXPR; | |
1353 | } | |
1354 | if (code == RSHIFT_EXPR) | |
1355 | { | |
45639915 | 1356 | *mask = wi::rshift (wi::ext (r1mask, width, sgn), shift, sgn); |
1357 | *val = wi::rshift (wi::ext (r1val, width, sgn), shift, sgn); | |
e913b5cd | 1358 | } |
1359 | else | |
1360 | { | |
45639915 | 1361 | *mask = wi::ext (wi::lshift (r1mask, shift), width, sgn); |
1362 | *val = wi::ext (wi::lshift (r1val, shift), width, sgn); | |
e913b5cd | 1363 | } |
1364 | } | |
b7e55469 | 1365 | } |
1366 | break; | |
1367 | ||
1368 | case PLUS_EXPR: | |
1369 | case POINTER_PLUS_EXPR: | |
1370 | { | |
b7e55469 | 1371 | /* Do the addition with unknown bits set to zero, to give carry-ins of |
1372 | zero wherever possible. */ | |
ab2c1de8 | 1373 | widest_int lo = r1val.and_not (r1mask) + r2val.and_not (r2mask); |
796b6678 | 1374 | lo = wi::ext (lo, width, sgn); |
b7e55469 | 1375 | /* Do the addition with unknown bits set to one, to give carry-ins of |
1376 | one wherever possible. */ | |
ab2c1de8 | 1377 | widest_int hi = (r1val | r1mask) + (r2val | r2mask); |
796b6678 | 1378 | hi = wi::ext (hi, width, sgn); |
b7e55469 | 1379 | /* Each bit in the result is known if (a) the corresponding bits in |
1380 | both inputs are known, and (b) the carry-in to that bit position | |
1381 | is known. We can check condition (b) by seeing if we got the same | |
1382 | result with minimised carries as with maximised carries. */ | |
cf8f0e63 | 1383 | *mask = r1mask | r2mask | (lo ^ hi); |
796b6678 | 1384 | *mask = wi::ext (*mask, width, sgn); |
b7e55469 | 1385 | /* It shouldn't matter whether we choose lo or hi here. */ |
1386 | *val = lo; | |
1387 | break; | |
1388 | } | |
1389 | ||
1390 | case MINUS_EXPR: | |
1391 | { | |
5de9d3ed | 1392 | widest_int temv, temm; |
b7e55469 | 1393 | bit_value_unop_1 (NEGATE_EXPR, r2type, &temv, &temm, |
1394 | r2type, r2val, r2mask); | |
1395 | bit_value_binop_1 (PLUS_EXPR, type, val, mask, | |
1396 | r1type, r1val, r1mask, | |
1397 | r2type, temv, temm); | |
1398 | break; | |
1399 | } | |
1400 | ||
1401 | case MULT_EXPR: | |
1402 | { | |
1403 | /* Just track trailing zeros in both operands and transfer | |
1404 | them to the other. */ | |
796b6678 | 1405 | int r1tz = wi::ctz (r1val | r1mask); |
1406 | int r2tz = wi::ctz (r2val | r2mask); | |
e913b5cd | 1407 | if (r1tz + r2tz >= width) |
b7e55469 | 1408 | { |
e913b5cd | 1409 | *mask = 0; |
1410 | *val = 0; | |
b7e55469 | 1411 | } |
1412 | else if (r1tz + r2tz > 0) | |
1413 | { | |
5de9d3ed | 1414 | *mask = wi::ext (wi::mask <widest_int> (r1tz + r2tz, true), |
796b6678 | 1415 | width, sgn); |
e913b5cd | 1416 | *val = 0; |
b7e55469 | 1417 | } |
1418 | break; | |
1419 | } | |
1420 | ||
1421 | case EQ_EXPR: | |
1422 | case NE_EXPR: | |
1423 | { | |
5de9d3ed | 1424 | widest_int m = r1mask | r2mask; |
cf8f0e63 | 1425 | if (r1val.and_not (m) != r2val.and_not (m)) |
b7e55469 | 1426 | { |
e913b5cd | 1427 | *mask = 0; |
1428 | *val = ((code == EQ_EXPR) ? 0 : 1); | |
b7e55469 | 1429 | } |
1430 | else | |
1431 | { | |
1432 | /* We know the result of a comparison is always one or zero. */ | |
e913b5cd | 1433 | *mask = 1; |
1434 | *val = 0; | |
b7e55469 | 1435 | } |
1436 | break; | |
1437 | } | |
1438 | ||
1439 | case GE_EXPR: | |
1440 | case GT_EXPR: | |
10c3fe8d | 1441 | swap_p = true; |
1442 | code = swap_tree_comparison (code); | |
1443 | /* Fall through. */ | |
b7e55469 | 1444 | case LT_EXPR: |
1445 | case LE_EXPR: | |
1446 | { | |
1447 | int minmax, maxmin; | |
e913b5cd | 1448 | |
10c3fe8d | 1449 | const widest_int &o1val = swap_p ? r2val : r1val; |
1450 | const widest_int &o1mask = swap_p ? r2mask : r1mask; | |
1451 | const widest_int &o2val = swap_p ? r1val : r2val; | |
1452 | const widest_int &o2mask = swap_p ? r1mask : r2mask; | |
1453 | ||
b7e55469 | 1454 | /* If the most significant bits are not known we know nothing. */ |
796b6678 | 1455 | if (wi::neg_p (o1mask) || wi::neg_p (o2mask)) |
b7e55469 | 1456 | break; |
1457 | ||
90c0f5b7 | 1458 | /* For comparisons the signedness is in the comparison operands. */ |
e913b5cd | 1459 | sgn = TYPE_SIGN (r1type); |
90c0f5b7 | 1460 | |
b7e55469 | 1461 | /* If we know the most significant bits we know the values |
1462 | value ranges by means of treating varying bits as zero | |
1463 | or one. Do a cross comparison of the max/min pairs. */ | |
796b6678 | 1464 | maxmin = wi::cmp (o1val | o1mask, o2val.and_not (o2mask), sgn); |
1465 | minmax = wi::cmp (o1val.and_not (o1mask), o2val | o2mask, sgn); | |
e913b5cd | 1466 | if (maxmin < 0) /* o1 is less than o2. */ |
b7e55469 | 1467 | { |
e913b5cd | 1468 | *mask = 0; |
1469 | *val = 1; | |
b7e55469 | 1470 | } |
e913b5cd | 1471 | else if (minmax > 0) /* o1 is not less or equal to o2. */ |
b7e55469 | 1472 | { |
e913b5cd | 1473 | *mask = 0; |
1474 | *val = 0; | |
b7e55469 | 1475 | } |
e913b5cd | 1476 | else if (maxmin == minmax) /* o1 and o2 are equal. */ |
b7e55469 | 1477 | { |
1478 | /* This probably should never happen as we'd have | |
1479 | folded the thing during fully constant value folding. */ | |
e913b5cd | 1480 | *mask = 0; |
1481 | *val = (code == LE_EXPR ? 1 : 0); | |
b7e55469 | 1482 | } |
1483 | else | |
1484 | { | |
1485 | /* We know the result of a comparison is always one or zero. */ | |
e913b5cd | 1486 | *mask = 1; |
1487 | *val = 0; | |
b7e55469 | 1488 | } |
1489 | break; | |
1490 | } | |
1491 | ||
1492 | default:; | |
1493 | } | |
1494 | } | |
1495 | ||
1496 | /* Return the propagation value when applying the operation CODE to | |
1497 | the value RHS yielding type TYPE. */ | |
1498 | ||
9908fe4d | 1499 | static ccp_prop_value_t |
b7e55469 | 1500 | bit_value_unop (enum tree_code code, tree type, tree rhs) |
1501 | { | |
9908fe4d | 1502 | ccp_prop_value_t rval = get_value_for_expr (rhs, true); |
5de9d3ed | 1503 | widest_int value, mask; |
9908fe4d | 1504 | ccp_prop_value_t val; |
c91fedc5 | 1505 | |
1506 | if (rval.lattice_val == UNDEFINED) | |
1507 | return rval; | |
1508 | ||
b7e55469 | 1509 | gcc_assert ((rval.lattice_val == CONSTANT |
1510 | && TREE_CODE (rval.value) == INTEGER_CST) | |
c90d2c17 | 1511 | || wi::sext (rval.mask, TYPE_PRECISION (TREE_TYPE (rhs))) == -1); |
b7e55469 | 1512 | bit_value_unop_1 (code, type, &value, &mask, |
e913b5cd | 1513 | TREE_TYPE (rhs), value_to_wide_int (rval), rval.mask); |
c90d2c17 | 1514 | if (wi::sext (mask, TYPE_PRECISION (type)) != -1) |
b7e55469 | 1515 | { |
1516 | val.lattice_val = CONSTANT; | |
1517 | val.mask = mask; | |
1518 | /* ??? Delay building trees here. */ | |
e913b5cd | 1519 | val.value = wide_int_to_tree (type, value); |
b7e55469 | 1520 | } |
1521 | else | |
1522 | { | |
1523 | val.lattice_val = VARYING; | |
1524 | val.value = NULL_TREE; | |
e913b5cd | 1525 | val.mask = -1; |
b7e55469 | 1526 | } |
1527 | return val; | |
1528 | } | |
1529 | ||
1530 | /* Return the propagation value when applying the operation CODE to | |
1531 | the values RHS1 and RHS2 yielding type TYPE. */ | |
1532 | ||
9908fe4d | 1533 | static ccp_prop_value_t |
b7e55469 | 1534 | bit_value_binop (enum tree_code code, tree type, tree rhs1, tree rhs2) |
1535 | { | |
9908fe4d | 1536 | ccp_prop_value_t r1val = get_value_for_expr (rhs1, true); |
1537 | ccp_prop_value_t r2val = get_value_for_expr (rhs2, true); | |
5de9d3ed | 1538 | widest_int value, mask; |
9908fe4d | 1539 | ccp_prop_value_t val; |
c91fedc5 | 1540 | |
1541 | if (r1val.lattice_val == UNDEFINED | |
1542 | || r2val.lattice_val == UNDEFINED) | |
1543 | { | |
1544 | val.lattice_val = VARYING; | |
1545 | val.value = NULL_TREE; | |
e913b5cd | 1546 | val.mask = -1; |
c91fedc5 | 1547 | return val; |
1548 | } | |
1549 | ||
b7e55469 | 1550 | gcc_assert ((r1val.lattice_val == CONSTANT |
1551 | && TREE_CODE (r1val.value) == INTEGER_CST) | |
c90d2c17 | 1552 | || wi::sext (r1val.mask, |
1553 | TYPE_PRECISION (TREE_TYPE (rhs1))) == -1); | |
b7e55469 | 1554 | gcc_assert ((r2val.lattice_val == CONSTANT |
1555 | && TREE_CODE (r2val.value) == INTEGER_CST) | |
c90d2c17 | 1556 | || wi::sext (r2val.mask, |
1557 | TYPE_PRECISION (TREE_TYPE (rhs2))) == -1); | |
b7e55469 | 1558 | bit_value_binop_1 (code, type, &value, &mask, |
e913b5cd | 1559 | TREE_TYPE (rhs1), value_to_wide_int (r1val), r1val.mask, |
1560 | TREE_TYPE (rhs2), value_to_wide_int (r2val), r2val.mask); | |
c90d2c17 | 1561 | if (wi::sext (mask, TYPE_PRECISION (type)) != -1) |
b7e55469 | 1562 | { |
1563 | val.lattice_val = CONSTANT; | |
1564 | val.mask = mask; | |
1565 | /* ??? Delay building trees here. */ | |
e913b5cd | 1566 | val.value = wide_int_to_tree (type, value); |
b7e55469 | 1567 | } |
1568 | else | |
1569 | { | |
1570 | val.lattice_val = VARYING; | |
1571 | val.value = NULL_TREE; | |
e913b5cd | 1572 | val.mask = -1; |
b7e55469 | 1573 | } |
1574 | return val; | |
1575 | } | |
1576 | ||
237e78b1 | 1577 | /* Return the propagation value for __builtin_assume_aligned |
1578 | and functions with assume_aligned or alloc_aligned attribute. | |
1579 | For __builtin_assume_aligned, ATTR is NULL_TREE, | |
1580 | for assume_aligned attribute ATTR is non-NULL and ALLOC_ALIGNED | |
1581 | is false, for alloc_aligned attribute ATTR is non-NULL and | |
1582 | ALLOC_ALIGNED is true. */ | |
fca0886c | 1583 | |
9908fe4d | 1584 | static ccp_prop_value_t |
1585 | bit_value_assume_aligned (gimple stmt, tree attr, ccp_prop_value_t ptrval, | |
237e78b1 | 1586 | bool alloc_aligned) |
fca0886c | 1587 | { |
237e78b1 | 1588 | tree align, misalign = NULL_TREE, type; |
fca0886c | 1589 | unsigned HOST_WIDE_INT aligni, misaligni = 0; |
9908fe4d | 1590 | ccp_prop_value_t alignval; |
5de9d3ed | 1591 | widest_int value, mask; |
9908fe4d | 1592 | ccp_prop_value_t val; |
e913b5cd | 1593 | |
237e78b1 | 1594 | if (attr == NULL_TREE) |
1595 | { | |
1596 | tree ptr = gimple_call_arg (stmt, 0); | |
1597 | type = TREE_TYPE (ptr); | |
1598 | ptrval = get_value_for_expr (ptr, true); | |
1599 | } | |
1600 | else | |
1601 | { | |
1602 | tree lhs = gimple_call_lhs (stmt); | |
1603 | type = TREE_TYPE (lhs); | |
1604 | } | |
1605 | ||
fca0886c | 1606 | if (ptrval.lattice_val == UNDEFINED) |
1607 | return ptrval; | |
1608 | gcc_assert ((ptrval.lattice_val == CONSTANT | |
1609 | && TREE_CODE (ptrval.value) == INTEGER_CST) | |
c90d2c17 | 1610 | || wi::sext (ptrval.mask, TYPE_PRECISION (type)) == -1); |
237e78b1 | 1611 | if (attr == NULL_TREE) |
fca0886c | 1612 | { |
237e78b1 | 1613 | /* Get aligni and misaligni from __builtin_assume_aligned. */ |
1614 | align = gimple_call_arg (stmt, 1); | |
1615 | if (!tree_fits_uhwi_p (align)) | |
fca0886c | 1616 | return ptrval; |
237e78b1 | 1617 | aligni = tree_to_uhwi (align); |
1618 | if (gimple_call_num_args (stmt) > 2) | |
1619 | { | |
1620 | misalign = gimple_call_arg (stmt, 2); | |
1621 | if (!tree_fits_uhwi_p (misalign)) | |
1622 | return ptrval; | |
1623 | misaligni = tree_to_uhwi (misalign); | |
1624 | } | |
1625 | } | |
1626 | else | |
fca0886c | 1627 | { |
237e78b1 | 1628 | /* Get aligni and misaligni from assume_aligned or |
1629 | alloc_align attributes. */ | |
1630 | if (TREE_VALUE (attr) == NULL_TREE) | |
fca0886c | 1631 | return ptrval; |
237e78b1 | 1632 | attr = TREE_VALUE (attr); |
1633 | align = TREE_VALUE (attr); | |
1634 | if (!tree_fits_uhwi_p (align)) | |
fca0886c | 1635 | return ptrval; |
237e78b1 | 1636 | aligni = tree_to_uhwi (align); |
1637 | if (alloc_aligned) | |
1638 | { | |
1639 | if (aligni == 0 || aligni > gimple_call_num_args (stmt)) | |
1640 | return ptrval; | |
1641 | align = gimple_call_arg (stmt, aligni - 1); | |
1642 | if (!tree_fits_uhwi_p (align)) | |
1643 | return ptrval; | |
1644 | aligni = tree_to_uhwi (align); | |
1645 | } | |
1646 | else if (TREE_CHAIN (attr) && TREE_VALUE (TREE_CHAIN (attr))) | |
1647 | { | |
1648 | misalign = TREE_VALUE (TREE_CHAIN (attr)); | |
1649 | if (!tree_fits_uhwi_p (misalign)) | |
1650 | return ptrval; | |
1651 | misaligni = tree_to_uhwi (misalign); | |
1652 | } | |
fca0886c | 1653 | } |
237e78b1 | 1654 | if (aligni <= 1 || (aligni & (aligni - 1)) != 0 || misaligni >= aligni) |
1655 | return ptrval; | |
1656 | ||
fca0886c | 1657 | align = build_int_cst_type (type, -aligni); |
1658 | alignval = get_value_for_expr (align, true); | |
1659 | bit_value_binop_1 (BIT_AND_EXPR, type, &value, &mask, | |
e913b5cd | 1660 | type, value_to_wide_int (ptrval), ptrval.mask, |
1661 | type, value_to_wide_int (alignval), alignval.mask); | |
c90d2c17 | 1662 | if (wi::sext (mask, TYPE_PRECISION (type)) != -1) |
fca0886c | 1663 | { |
1664 | val.lattice_val = CONSTANT; | |
1665 | val.mask = mask; | |
e913b5cd | 1666 | gcc_assert ((mask.to_uhwi () & (aligni - 1)) == 0); |
1667 | gcc_assert ((value.to_uhwi () & (aligni - 1)) == 0); | |
1668 | value |= misaligni; | |
fca0886c | 1669 | /* ??? Delay building trees here. */ |
e913b5cd | 1670 | val.value = wide_int_to_tree (type, value); |
fca0886c | 1671 | } |
1672 | else | |
1673 | { | |
1674 | val.lattice_val = VARYING; | |
1675 | val.value = NULL_TREE; | |
e913b5cd | 1676 | val.mask = -1; |
fca0886c | 1677 | } |
1678 | return val; | |
1679 | } | |
1680 | ||
75a70cf9 | 1681 | /* Evaluate statement STMT. |
1682 | Valid only for assignments, calls, conditionals, and switches. */ | |
4ee9c684 | 1683 | |
9908fe4d | 1684 | static ccp_prop_value_t |
75a70cf9 | 1685 | evaluate_stmt (gimple stmt) |
4ee9c684 | 1686 | { |
9908fe4d | 1687 | ccp_prop_value_t val; |
4f61cce6 | 1688 | tree simplified = NULL_TREE; |
88dbf20f | 1689 | ccp_lattice_t likelyvalue = likely_value (stmt); |
b7e55469 | 1690 | bool is_constant = false; |
581bf1c2 | 1691 | unsigned int align; |
88dbf20f | 1692 | |
b7e55469 | 1693 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1694 | { | |
1695 | fprintf (dump_file, "which is likely "); | |
1696 | switch (likelyvalue) | |
1697 | { | |
1698 | case CONSTANT: | |
1699 | fprintf (dump_file, "CONSTANT"); | |
1700 | break; | |
1701 | case UNDEFINED: | |
1702 | fprintf (dump_file, "UNDEFINED"); | |
1703 | break; | |
1704 | case VARYING: | |
1705 | fprintf (dump_file, "VARYING"); | |
1706 | break; | |
1707 | default:; | |
1708 | } | |
1709 | fprintf (dump_file, "\n"); | |
1710 | } | |
add6ee5e | 1711 | |
4ee9c684 | 1712 | /* If the statement is likely to have a CONSTANT result, then try |
1713 | to fold the statement to determine the constant value. */ | |
75a70cf9 | 1714 | /* FIXME. This is the only place that we call ccp_fold. |
1715 | Since likely_value never returns CONSTANT for calls, we will | |
1716 | not attempt to fold them, including builtins that may profit. */ | |
4ee9c684 | 1717 | if (likelyvalue == CONSTANT) |
b7e55469 | 1718 | { |
1719 | fold_defer_overflow_warnings (); | |
1720 | simplified = ccp_fold (stmt); | |
1721 | is_constant = simplified && is_gimple_min_invariant (simplified); | |
1722 | fold_undefer_overflow_warnings (is_constant, stmt, 0); | |
1723 | if (is_constant) | |
1724 | { | |
1725 | /* The statement produced a constant value. */ | |
1726 | val.lattice_val = CONSTANT; | |
1727 | val.value = simplified; | |
e913b5cd | 1728 | val.mask = 0; |
b7e55469 | 1729 | } |
1730 | } | |
4ee9c684 | 1731 | /* If the statement is likely to have a VARYING result, then do not |
1732 | bother folding the statement. */ | |
04236c3a | 1733 | else if (likelyvalue == VARYING) |
75a70cf9 | 1734 | { |
590c3166 | 1735 | enum gimple_code code = gimple_code (stmt); |
75a70cf9 | 1736 | if (code == GIMPLE_ASSIGN) |
1737 | { | |
1738 | enum tree_code subcode = gimple_assign_rhs_code (stmt); | |
48e1416a | 1739 | |
75a70cf9 | 1740 | /* Other cases cannot satisfy is_gimple_min_invariant |
1741 | without folding. */ | |
1742 | if (get_gimple_rhs_class (subcode) == GIMPLE_SINGLE_RHS) | |
1743 | simplified = gimple_assign_rhs1 (stmt); | |
1744 | } | |
1745 | else if (code == GIMPLE_SWITCH) | |
1a91d914 | 1746 | simplified = gimple_switch_index (as_a <gswitch *> (stmt)); |
75a70cf9 | 1747 | else |
a65c4d64 | 1748 | /* These cannot satisfy is_gimple_min_invariant without folding. */ |
1749 | gcc_assert (code == GIMPLE_CALL || code == GIMPLE_COND); | |
b7e55469 | 1750 | is_constant = simplified && is_gimple_min_invariant (simplified); |
1751 | if (is_constant) | |
1752 | { | |
1753 | /* The statement produced a constant value. */ | |
1754 | val.lattice_val = CONSTANT; | |
1755 | val.value = simplified; | |
e913b5cd | 1756 | val.mask = 0; |
b7e55469 | 1757 | } |
75a70cf9 | 1758 | } |
4ee9c684 | 1759 | |
b7e55469 | 1760 | /* Resort to simplification for bitwise tracking. */ |
1761 | if (flag_tree_bit_ccp | |
db48deb0 | 1762 | && (likelyvalue == CONSTANT || is_gimple_call (stmt) |
1763 | || (gimple_assign_single_p (stmt) | |
1764 | && gimple_assign_rhs_code (stmt) == ADDR_EXPR)) | |
b7e55469 | 1765 | && !is_constant) |
912f109f | 1766 | { |
b7e55469 | 1767 | enum gimple_code code = gimple_code (stmt); |
1768 | val.lattice_val = VARYING; | |
1769 | val.value = NULL_TREE; | |
e913b5cd | 1770 | val.mask = -1; |
b7e55469 | 1771 | if (code == GIMPLE_ASSIGN) |
912f109f | 1772 | { |
b7e55469 | 1773 | enum tree_code subcode = gimple_assign_rhs_code (stmt); |
1774 | tree rhs1 = gimple_assign_rhs1 (stmt); | |
c0a4b664 | 1775 | tree lhs = gimple_assign_lhs (stmt); |
1776 | if ((INTEGRAL_TYPE_P (TREE_TYPE (lhs)) | |
1777 | || POINTER_TYPE_P (TREE_TYPE (lhs))) | |
1778 | && (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
1779 | || POINTER_TYPE_P (TREE_TYPE (rhs1)))) | |
1780 | switch (get_gimple_rhs_class (subcode)) | |
1781 | { | |
1782 | case GIMPLE_SINGLE_RHS: | |
1783 | val = get_value_for_expr (rhs1, true); | |
1784 | break; | |
1785 | ||
1786 | case GIMPLE_UNARY_RHS: | |
1787 | val = bit_value_unop (subcode, TREE_TYPE (lhs), rhs1); | |
1788 | break; | |
1789 | ||
1790 | case GIMPLE_BINARY_RHS: | |
1791 | val = bit_value_binop (subcode, TREE_TYPE (lhs), rhs1, | |
1792 | gimple_assign_rhs2 (stmt)); | |
1793 | break; | |
1794 | ||
1795 | default:; | |
1796 | } | |
912f109f | 1797 | } |
b7e55469 | 1798 | else if (code == GIMPLE_COND) |
1799 | { | |
1800 | enum tree_code code = gimple_cond_code (stmt); | |
1801 | tree rhs1 = gimple_cond_lhs (stmt); | |
1802 | tree rhs2 = gimple_cond_rhs (stmt); | |
1803 | if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
1804 | || POINTER_TYPE_P (TREE_TYPE (rhs1))) | |
1805 | val = bit_value_binop (code, TREE_TYPE (rhs1), rhs1, rhs2); | |
1806 | } | |
0b4f0116 | 1807 | else if (gimple_call_builtin_p (stmt, BUILT_IN_NORMAL)) |
153c3b50 | 1808 | { |
0b4f0116 | 1809 | tree fndecl = gimple_call_fndecl (stmt); |
153c3b50 | 1810 | switch (DECL_FUNCTION_CODE (fndecl)) |
1811 | { | |
1812 | case BUILT_IN_MALLOC: | |
1813 | case BUILT_IN_REALLOC: | |
1814 | case BUILT_IN_CALLOC: | |
939514e9 | 1815 | case BUILT_IN_STRDUP: |
1816 | case BUILT_IN_STRNDUP: | |
153c3b50 | 1817 | val.lattice_val = CONSTANT; |
1818 | val.value = build_int_cst (TREE_TYPE (gimple_get_lhs (stmt)), 0); | |
796b6678 | 1819 | val.mask = ~((HOST_WIDE_INT) MALLOC_ABI_ALIGNMENT |
1820 | / BITS_PER_UNIT - 1); | |
153c3b50 | 1821 | break; |
1822 | ||
1823 | case BUILT_IN_ALLOCA: | |
581bf1c2 | 1824 | case BUILT_IN_ALLOCA_WITH_ALIGN: |
1825 | align = (DECL_FUNCTION_CODE (fndecl) == BUILT_IN_ALLOCA_WITH_ALIGN | |
f9ae6f95 | 1826 | ? TREE_INT_CST_LOW (gimple_call_arg (stmt, 1)) |
581bf1c2 | 1827 | : BIGGEST_ALIGNMENT); |
153c3b50 | 1828 | val.lattice_val = CONSTANT; |
1829 | val.value = build_int_cst (TREE_TYPE (gimple_get_lhs (stmt)), 0); | |
796b6678 | 1830 | val.mask = ~((HOST_WIDE_INT) align / BITS_PER_UNIT - 1); |
153c3b50 | 1831 | break; |
1832 | ||
939514e9 | 1833 | /* These builtins return their first argument, unmodified. */ |
1834 | case BUILT_IN_MEMCPY: | |
1835 | case BUILT_IN_MEMMOVE: | |
1836 | case BUILT_IN_MEMSET: | |
1837 | case BUILT_IN_STRCPY: | |
1838 | case BUILT_IN_STRNCPY: | |
1839 | case BUILT_IN_MEMCPY_CHK: | |
1840 | case BUILT_IN_MEMMOVE_CHK: | |
1841 | case BUILT_IN_MEMSET_CHK: | |
1842 | case BUILT_IN_STRCPY_CHK: | |
1843 | case BUILT_IN_STRNCPY_CHK: | |
1844 | val = get_value_for_expr (gimple_call_arg (stmt, 0), true); | |
1845 | break; | |
1846 | ||
fca0886c | 1847 | case BUILT_IN_ASSUME_ALIGNED: |
237e78b1 | 1848 | val = bit_value_assume_aligned (stmt, NULL_TREE, val, false); |
fca0886c | 1849 | break; |
1850 | ||
060fc206 | 1851 | case BUILT_IN_ALIGNED_ALLOC: |
1852 | { | |
1853 | tree align = get_constant_value (gimple_call_arg (stmt, 0)); | |
1854 | if (align | |
1855 | && tree_fits_uhwi_p (align)) | |
1856 | { | |
1857 | unsigned HOST_WIDE_INT aligni = tree_to_uhwi (align); | |
1858 | if (aligni > 1 | |
1859 | /* align must be power-of-two */ | |
1860 | && (aligni & (aligni - 1)) == 0) | |
1861 | { | |
1862 | val.lattice_val = CONSTANT; | |
1863 | val.value = build_int_cst (ptr_type_node, 0); | |
cd89b631 | 1864 | val.mask = -aligni; |
060fc206 | 1865 | } |
1866 | } | |
1867 | break; | |
1868 | } | |
1869 | ||
153c3b50 | 1870 | default:; |
1871 | } | |
1872 | } | |
237e78b1 | 1873 | if (is_gimple_call (stmt) && gimple_call_lhs (stmt)) |
1874 | { | |
1875 | tree fntype = gimple_call_fntype (stmt); | |
1876 | if (fntype) | |
1877 | { | |
1878 | tree attrs = lookup_attribute ("assume_aligned", | |
1879 | TYPE_ATTRIBUTES (fntype)); | |
1880 | if (attrs) | |
1881 | val = bit_value_assume_aligned (stmt, attrs, val, false); | |
1882 | attrs = lookup_attribute ("alloc_align", | |
1883 | TYPE_ATTRIBUTES (fntype)); | |
1884 | if (attrs) | |
1885 | val = bit_value_assume_aligned (stmt, attrs, val, true); | |
1886 | } | |
1887 | } | |
b7e55469 | 1888 | is_constant = (val.lattice_val == CONSTANT); |
912f109f | 1889 | } |
1890 | ||
fc08b993 | 1891 | if (flag_tree_bit_ccp |
1892 | && ((is_constant && TREE_CODE (val.value) == INTEGER_CST) | |
1893 | || (!is_constant && likelyvalue != UNDEFINED)) | |
1894 | && gimple_get_lhs (stmt) | |
1895 | && TREE_CODE (gimple_get_lhs (stmt)) == SSA_NAME) | |
1896 | { | |
1897 | tree lhs = gimple_get_lhs (stmt); | |
9c1be15e | 1898 | wide_int nonzero_bits = get_nonzero_bits (lhs); |
1899 | if (nonzero_bits != -1) | |
fc08b993 | 1900 | { |
1901 | if (!is_constant) | |
1902 | { | |
1903 | val.lattice_val = CONSTANT; | |
1904 | val.value = build_zero_cst (TREE_TYPE (lhs)); | |
9c1be15e | 1905 | val.mask = extend_mask (nonzero_bits); |
fc08b993 | 1906 | is_constant = true; |
1907 | } | |
1908 | else | |
1909 | { | |
9c1be15e | 1910 | if (wi::bit_and_not (val.value, nonzero_bits) != 0) |
aeb682a2 | 1911 | val.value = wide_int_to_tree (TREE_TYPE (lhs), |
9c1be15e | 1912 | nonzero_bits & val.value); |
aeb682a2 | 1913 | if (nonzero_bits == 0) |
1914 | val.mask = 0; | |
fc08b993 | 1915 | else |
09b2913a | 1916 | val.mask = val.mask & extend_mask (nonzero_bits); |
fc08b993 | 1917 | } |
1918 | } | |
1919 | } | |
1920 | ||
b7e55469 | 1921 | if (!is_constant) |
4ee9c684 | 1922 | { |
1923 | /* The statement produced a nonconstant value. If the statement | |
88dbf20f | 1924 | had UNDEFINED operands, then the result of the statement |
1925 | should be UNDEFINED. Otherwise, the statement is VARYING. */ | |
bfa30570 | 1926 | if (likelyvalue == UNDEFINED) |
b7e55469 | 1927 | { |
1928 | val.lattice_val = likelyvalue; | |
e913b5cd | 1929 | val.mask = 0; |
b7e55469 | 1930 | } |
b765fa12 | 1931 | else |
b7e55469 | 1932 | { |
1933 | val.lattice_val = VARYING; | |
e913b5cd | 1934 | val.mask = -1; |
b7e55469 | 1935 | } |
b765fa12 | 1936 | |
88dbf20f | 1937 | val.value = NULL_TREE; |
4ee9c684 | 1938 | } |
41511585 | 1939 | |
1940 | return val; | |
4ee9c684 | 1941 | } |
1942 | ||
c1f445d2 | 1943 | typedef hash_table<pointer_hash<gimple_statement_base> > gimple_htab; |
2b15d2ba | 1944 | |
582a80ed | 1945 | /* Given a BUILT_IN_STACK_SAVE value SAVED_VAL, insert a clobber of VAR before |
1946 | each matching BUILT_IN_STACK_RESTORE. Mark visited phis in VISITED. */ | |
1947 | ||
1948 | static void | |
2b15d2ba | 1949 | insert_clobber_before_stack_restore (tree saved_val, tree var, |
c1f445d2 | 1950 | gimple_htab **visited) |
582a80ed | 1951 | { |
1a91d914 | 1952 | gimple stmt; |
1953 | gassign *clobber_stmt; | |
582a80ed | 1954 | tree clobber; |
1955 | imm_use_iterator iter; | |
1956 | gimple_stmt_iterator i; | |
1957 | gimple *slot; | |
1958 | ||
1959 | FOR_EACH_IMM_USE_STMT (stmt, iter, saved_val) | |
1960 | if (gimple_call_builtin_p (stmt, BUILT_IN_STACK_RESTORE)) | |
1961 | { | |
f1f41a6c | 1962 | clobber = build_constructor (TREE_TYPE (var), |
1963 | NULL); | |
582a80ed | 1964 | TREE_THIS_VOLATILE (clobber) = 1; |
1965 | clobber_stmt = gimple_build_assign (var, clobber); | |
1966 | ||
1967 | i = gsi_for_stmt (stmt); | |
1968 | gsi_insert_before (&i, clobber_stmt, GSI_SAME_STMT); | |
1969 | } | |
1970 | else if (gimple_code (stmt) == GIMPLE_PHI) | |
1971 | { | |
c1f445d2 | 1972 | if (!*visited) |
1973 | *visited = new gimple_htab (10); | |
582a80ed | 1974 | |
c1f445d2 | 1975 | slot = (*visited)->find_slot (stmt, INSERT); |
582a80ed | 1976 | if (*slot != NULL) |
1977 | continue; | |
1978 | ||
1979 | *slot = stmt; | |
1980 | insert_clobber_before_stack_restore (gimple_phi_result (stmt), var, | |
1981 | visited); | |
1982 | } | |
42eed683 | 1983 | else if (gimple_assign_ssa_name_copy_p (stmt)) |
1984 | insert_clobber_before_stack_restore (gimple_assign_lhs (stmt), var, | |
1985 | visited); | |
058a1b7a | 1986 | else if (chkp_gimple_call_builtin_p (stmt, BUILT_IN_CHKP_BNDRET)) |
1987 | continue; | |
582a80ed | 1988 | else |
1989 | gcc_assert (is_gimple_debug (stmt)); | |
1990 | } | |
1991 | ||
1992 | /* Advance the iterator to the previous non-debug gimple statement in the same | |
1993 | or dominating basic block. */ | |
1994 | ||
1995 | static inline void | |
1996 | gsi_prev_dom_bb_nondebug (gimple_stmt_iterator *i) | |
1997 | { | |
1998 | basic_block dom; | |
1999 | ||
2000 | gsi_prev_nondebug (i); | |
2001 | while (gsi_end_p (*i)) | |
2002 | { | |
2003 | dom = get_immediate_dominator (CDI_DOMINATORS, i->bb); | |
34154e27 | 2004 | if (dom == NULL || dom == ENTRY_BLOCK_PTR_FOR_FN (cfun)) |
582a80ed | 2005 | return; |
2006 | ||
2007 | *i = gsi_last_bb (dom); | |
2008 | } | |
2009 | } | |
2010 | ||
2011 | /* Find a BUILT_IN_STACK_SAVE dominating gsi_stmt (I), and insert | |
1543f720 | 2012 | a clobber of VAR before each matching BUILT_IN_STACK_RESTORE. |
2013 | ||
2014 | It is possible that BUILT_IN_STACK_SAVE cannot be find in a dominator when a | |
2015 | previous pass (such as DOM) duplicated it along multiple paths to a BB. In | |
2016 | that case the function gives up without inserting the clobbers. */ | |
582a80ed | 2017 | |
2018 | static void | |
2019 | insert_clobbers_for_var (gimple_stmt_iterator i, tree var) | |
2020 | { | |
582a80ed | 2021 | gimple stmt; |
2022 | tree saved_val; | |
c1f445d2 | 2023 | gimple_htab *visited = NULL; |
582a80ed | 2024 | |
1543f720 | 2025 | for (; !gsi_end_p (i); gsi_prev_dom_bb_nondebug (&i)) |
582a80ed | 2026 | { |
2027 | stmt = gsi_stmt (i); | |
2028 | ||
2029 | if (!gimple_call_builtin_p (stmt, BUILT_IN_STACK_SAVE)) | |
2030 | continue; | |
582a80ed | 2031 | |
2032 | saved_val = gimple_call_lhs (stmt); | |
2033 | if (saved_val == NULL_TREE) | |
2034 | continue; | |
2035 | ||
2036 | insert_clobber_before_stack_restore (saved_val, var, &visited); | |
2037 | break; | |
2038 | } | |
2039 | ||
c1f445d2 | 2040 | delete visited; |
582a80ed | 2041 | } |
2042 | ||
581bf1c2 | 2043 | /* Detects a __builtin_alloca_with_align with constant size argument. Declares |
2044 | fixed-size array and returns the address, if found, otherwise returns | |
2045 | NULL_TREE. */ | |
9a65cc0a | 2046 | |
2047 | static tree | |
581bf1c2 | 2048 | fold_builtin_alloca_with_align (gimple stmt) |
9a65cc0a | 2049 | { |
2050 | unsigned HOST_WIDE_INT size, threshold, n_elem; | |
2051 | tree lhs, arg, block, var, elem_type, array_type; | |
9a65cc0a | 2052 | |
2053 | /* Get lhs. */ | |
2054 | lhs = gimple_call_lhs (stmt); | |
2055 | if (lhs == NULL_TREE) | |
2056 | return NULL_TREE; | |
2057 | ||
2058 | /* Detect constant argument. */ | |
2059 | arg = get_constant_value (gimple_call_arg (stmt, 0)); | |
6e93d308 | 2060 | if (arg == NULL_TREE |
2061 | || TREE_CODE (arg) != INTEGER_CST | |
e913b5cd | 2062 | || !tree_fits_uhwi_p (arg)) |
9a65cc0a | 2063 | return NULL_TREE; |
6e93d308 | 2064 | |
8c53c46c | 2065 | size = tree_to_uhwi (arg); |
9a65cc0a | 2066 | |
581bf1c2 | 2067 | /* Heuristic: don't fold large allocas. */ |
9a65cc0a | 2068 | threshold = (unsigned HOST_WIDE_INT)PARAM_VALUE (PARAM_LARGE_STACK_FRAME); |
581bf1c2 | 2069 | /* In case the alloca is located at function entry, it has the same lifetime |
2070 | as a declared array, so we allow a larger size. */ | |
9a65cc0a | 2071 | block = gimple_block (stmt); |
2072 | if (!(cfun->after_inlining | |
2073 | && TREE_CODE (BLOCK_SUPERCONTEXT (block)) == FUNCTION_DECL)) | |
2074 | threshold /= 10; | |
2075 | if (size > threshold) | |
2076 | return NULL_TREE; | |
2077 | ||
2078 | /* Declare array. */ | |
2079 | elem_type = build_nonstandard_integer_type (BITS_PER_UNIT, 1); | |
2080 | n_elem = size * 8 / BITS_PER_UNIT; | |
9a65cc0a | 2081 | array_type = build_array_type_nelts (elem_type, n_elem); |
f9e245b2 | 2082 | var = create_tmp_var (array_type); |
f9ae6f95 | 2083 | DECL_ALIGN (var) = TREE_INT_CST_LOW (gimple_call_arg (stmt, 1)); |
3d4a0a4b | 2084 | { |
2085 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (lhs); | |
2086 | if (pi != NULL && !pi->pt.anything) | |
2087 | { | |
2088 | bool singleton_p; | |
2089 | unsigned uid; | |
2090 | singleton_p = pt_solution_singleton_p (&pi->pt, &uid); | |
2091 | gcc_assert (singleton_p); | |
2092 | SET_DECL_PT_UID (var, uid); | |
2093 | } | |
2094 | } | |
9a65cc0a | 2095 | |
2096 | /* Fold alloca to the address of the array. */ | |
2097 | return fold_convert (TREE_TYPE (lhs), build_fold_addr_expr (var)); | |
2098 | } | |
2099 | ||
6688f8ec | 2100 | /* Fold the stmt at *GSI with CCP specific information that propagating |
2101 | and regular folding does not catch. */ | |
2102 | ||
2103 | static bool | |
2104 | ccp_fold_stmt (gimple_stmt_iterator *gsi) | |
2105 | { | |
2106 | gimple stmt = gsi_stmt (*gsi); | |
6688f8ec | 2107 | |
94144e68 | 2108 | switch (gimple_code (stmt)) |
2109 | { | |
2110 | case GIMPLE_COND: | |
2111 | { | |
1a91d914 | 2112 | gcond *cond_stmt = as_a <gcond *> (stmt); |
9908fe4d | 2113 | ccp_prop_value_t val; |
94144e68 | 2114 | /* Statement evaluation will handle type mismatches in constants |
2115 | more gracefully than the final propagation. This allows us to | |
2116 | fold more conditionals here. */ | |
2117 | val = evaluate_stmt (stmt); | |
2118 | if (val.lattice_val != CONSTANT | |
796b6678 | 2119 | || val.mask != 0) |
94144e68 | 2120 | return false; |
2121 | ||
b7e55469 | 2122 | if (dump_file) |
2123 | { | |
2124 | fprintf (dump_file, "Folding predicate "); | |
2125 | print_gimple_expr (dump_file, stmt, 0, 0); | |
2126 | fprintf (dump_file, " to "); | |
2127 | print_generic_expr (dump_file, val.value, 0); | |
2128 | fprintf (dump_file, "\n"); | |
2129 | } | |
2130 | ||
94144e68 | 2131 | if (integer_zerop (val.value)) |
1a91d914 | 2132 | gimple_cond_make_false (cond_stmt); |
94144e68 | 2133 | else |
1a91d914 | 2134 | gimple_cond_make_true (cond_stmt); |
6688f8ec | 2135 | |
94144e68 | 2136 | return true; |
2137 | } | |
6688f8ec | 2138 | |
94144e68 | 2139 | case GIMPLE_CALL: |
2140 | { | |
2141 | tree lhs = gimple_call_lhs (stmt); | |
3064bb7b | 2142 | int flags = gimple_call_flags (stmt); |
15d138c9 | 2143 | tree val; |
94144e68 | 2144 | tree argt; |
2145 | bool changed = false; | |
2146 | unsigned i; | |
2147 | ||
2148 | /* If the call was folded into a constant make sure it goes | |
2149 | away even if we cannot propagate into all uses because of | |
2150 | type issues. */ | |
2151 | if (lhs | |
2152 | && TREE_CODE (lhs) == SSA_NAME | |
3064bb7b | 2153 | && (val = get_constant_value (lhs)) |
2154 | /* Don't optimize away calls that have side-effects. */ | |
2155 | && (flags & (ECF_CONST|ECF_PURE)) != 0 | |
2156 | && (flags & ECF_LOOPING_CONST_OR_PURE) == 0) | |
94144e68 | 2157 | { |
15d138c9 | 2158 | tree new_rhs = unshare_expr (val); |
338cce8f | 2159 | bool res; |
94144e68 | 2160 | if (!useless_type_conversion_p (TREE_TYPE (lhs), |
2161 | TREE_TYPE (new_rhs))) | |
2162 | new_rhs = fold_convert (TREE_TYPE (lhs), new_rhs); | |
338cce8f | 2163 | res = update_call_from_tree (gsi, new_rhs); |
2164 | gcc_assert (res); | |
94144e68 | 2165 | return true; |
2166 | } | |
2167 | ||
fb049fba | 2168 | /* Internal calls provide no argument types, so the extra laxity |
2169 | for normal calls does not apply. */ | |
2170 | if (gimple_call_internal_p (stmt)) | |
2171 | return false; | |
2172 | ||
581bf1c2 | 2173 | /* The heuristic of fold_builtin_alloca_with_align differs before and |
2174 | after inlining, so we don't require the arg to be changed into a | |
2175 | constant for folding, but just to be constant. */ | |
2176 | if (gimple_call_builtin_p (stmt, BUILT_IN_ALLOCA_WITH_ALIGN)) | |
9a65cc0a | 2177 | { |
581bf1c2 | 2178 | tree new_rhs = fold_builtin_alloca_with_align (stmt); |
6e93d308 | 2179 | if (new_rhs) |
2180 | { | |
2181 | bool res = update_call_from_tree (gsi, new_rhs); | |
582a80ed | 2182 | tree var = TREE_OPERAND (TREE_OPERAND (new_rhs, 0),0); |
6e93d308 | 2183 | gcc_assert (res); |
582a80ed | 2184 | insert_clobbers_for_var (*gsi, var); |
6e93d308 | 2185 | return true; |
2186 | } | |
9a65cc0a | 2187 | } |
2188 | ||
94144e68 | 2189 | /* Propagate into the call arguments. Compared to replace_uses_in |
2190 | this can use the argument slot types for type verification | |
2191 | instead of the current argument type. We also can safely | |
2192 | drop qualifiers here as we are dealing with constants anyway. */ | |
2de00a2d | 2193 | argt = TYPE_ARG_TYPES (gimple_call_fntype (stmt)); |
94144e68 | 2194 | for (i = 0; i < gimple_call_num_args (stmt) && argt; |
2195 | ++i, argt = TREE_CHAIN (argt)) | |
2196 | { | |
2197 | tree arg = gimple_call_arg (stmt, i); | |
2198 | if (TREE_CODE (arg) == SSA_NAME | |
15d138c9 | 2199 | && (val = get_constant_value (arg)) |
94144e68 | 2200 | && useless_type_conversion_p |
2201 | (TYPE_MAIN_VARIANT (TREE_VALUE (argt)), | |
15d138c9 | 2202 | TYPE_MAIN_VARIANT (TREE_TYPE (val)))) |
94144e68 | 2203 | { |
15d138c9 | 2204 | gimple_call_set_arg (stmt, i, unshare_expr (val)); |
94144e68 | 2205 | changed = true; |
2206 | } | |
2207 | } | |
e16f4c39 | 2208 | |
94144e68 | 2209 | return changed; |
2210 | } | |
6688f8ec | 2211 | |
6872bf3c | 2212 | case GIMPLE_ASSIGN: |
2213 | { | |
2214 | tree lhs = gimple_assign_lhs (stmt); | |
15d138c9 | 2215 | tree val; |
6872bf3c | 2216 | |
2217 | /* If we have a load that turned out to be constant replace it | |
2218 | as we cannot propagate into all uses in all cases. */ | |
2219 | if (gimple_assign_single_p (stmt) | |
2220 | && TREE_CODE (lhs) == SSA_NAME | |
15d138c9 | 2221 | && (val = get_constant_value (lhs))) |
6872bf3c | 2222 | { |
15d138c9 | 2223 | tree rhs = unshare_expr (val); |
6872bf3c | 2224 | if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs))) |
182cf5a9 | 2225 | rhs = fold_build1 (VIEW_CONVERT_EXPR, TREE_TYPE (lhs), rhs); |
6872bf3c | 2226 | gimple_assign_set_rhs_from_tree (gsi, rhs); |
2227 | return true; | |
2228 | } | |
2229 | ||
2230 | return false; | |
2231 | } | |
2232 | ||
94144e68 | 2233 | default: |
2234 | return false; | |
2235 | } | |
6688f8ec | 2236 | } |
2237 | ||
41511585 | 2238 | /* Visit the assignment statement STMT. Set the value of its LHS to the |
88dbf20f | 2239 | value computed by the RHS and store LHS in *OUTPUT_P. If STMT |
2240 | creates virtual definitions, set the value of each new name to that | |
75a70cf9 | 2241 | of the RHS (if we can derive a constant out of the RHS). |
2242 | Value-returning call statements also perform an assignment, and | |
2243 | are handled here. */ | |
4ee9c684 | 2244 | |
41511585 | 2245 | static enum ssa_prop_result |
75a70cf9 | 2246 | visit_assignment (gimple stmt, tree *output_p) |
4ee9c684 | 2247 | { |
9908fe4d | 2248 | ccp_prop_value_t val; |
88dbf20f | 2249 | enum ssa_prop_result retval; |
4ee9c684 | 2250 | |
75a70cf9 | 2251 | tree lhs = gimple_get_lhs (stmt); |
4ee9c684 | 2252 | |
75a70cf9 | 2253 | gcc_assert (gimple_code (stmt) != GIMPLE_CALL |
2254 | || gimple_call_lhs (stmt) != NULL_TREE); | |
2255 | ||
15d138c9 | 2256 | if (gimple_assign_single_p (stmt) |
2257 | && gimple_assign_rhs_code (stmt) == SSA_NAME) | |
2258 | /* For a simple copy operation, we copy the lattice values. */ | |
2259 | val = *get_value (gimple_assign_rhs1 (stmt)); | |
41511585 | 2260 | else |
75a70cf9 | 2261 | /* Evaluate the statement, which could be |
2262 | either a GIMPLE_ASSIGN or a GIMPLE_CALL. */ | |
04236c3a | 2263 | val = evaluate_stmt (stmt); |
4ee9c684 | 2264 | |
88dbf20f | 2265 | retval = SSA_PROP_NOT_INTERESTING; |
4ee9c684 | 2266 | |
41511585 | 2267 | /* Set the lattice value of the statement's output. */ |
88dbf20f | 2268 | if (TREE_CODE (lhs) == SSA_NAME) |
4ee9c684 | 2269 | { |
88dbf20f | 2270 | /* If STMT is an assignment to an SSA_NAME, we only have one |
2271 | value to set. */ | |
2272 | if (set_lattice_value (lhs, val)) | |
2273 | { | |
2274 | *output_p = lhs; | |
2275 | if (val.lattice_val == VARYING) | |
2276 | retval = SSA_PROP_VARYING; | |
2277 | else | |
2278 | retval = SSA_PROP_INTERESTING; | |
2279 | } | |
4ee9c684 | 2280 | } |
88dbf20f | 2281 | |
2282 | return retval; | |
4ee9c684 | 2283 | } |
2284 | ||
4ee9c684 | 2285 | |
41511585 | 2286 | /* Visit the conditional statement STMT. Return SSA_PROP_INTERESTING |
2287 | if it can determine which edge will be taken. Otherwise, return | |
2288 | SSA_PROP_VARYING. */ | |
2289 | ||
2290 | static enum ssa_prop_result | |
75a70cf9 | 2291 | visit_cond_stmt (gimple stmt, edge *taken_edge_p) |
4ee9c684 | 2292 | { |
9908fe4d | 2293 | ccp_prop_value_t val; |
41511585 | 2294 | basic_block block; |
2295 | ||
75a70cf9 | 2296 | block = gimple_bb (stmt); |
41511585 | 2297 | val = evaluate_stmt (stmt); |
b7e55469 | 2298 | if (val.lattice_val != CONSTANT |
796b6678 | 2299 | || val.mask != 0) |
b7e55469 | 2300 | return SSA_PROP_VARYING; |
41511585 | 2301 | |
2302 | /* Find which edge out of the conditional block will be taken and add it | |
2303 | to the worklist. If no single edge can be determined statically, | |
2304 | return SSA_PROP_VARYING to feed all the outgoing edges to the | |
2305 | propagation engine. */ | |
b7e55469 | 2306 | *taken_edge_p = find_taken_edge (block, val.value); |
41511585 | 2307 | if (*taken_edge_p) |
2308 | return SSA_PROP_INTERESTING; | |
2309 | else | |
2310 | return SSA_PROP_VARYING; | |
4ee9c684 | 2311 | } |
2312 | ||
4ee9c684 | 2313 | |
41511585 | 2314 | /* Evaluate statement STMT. If the statement produces an output value and |
2315 | its evaluation changes the lattice value of its output, return | |
2316 | SSA_PROP_INTERESTING and set *OUTPUT_P to the SSA_NAME holding the | |
2317 | output value. | |
48e1416a | 2318 | |
41511585 | 2319 | If STMT is a conditional branch and we can determine its truth |
2320 | value, set *TAKEN_EDGE_P accordingly. If STMT produces a varying | |
2321 | value, return SSA_PROP_VARYING. */ | |
4ee9c684 | 2322 | |
41511585 | 2323 | static enum ssa_prop_result |
75a70cf9 | 2324 | ccp_visit_stmt (gimple stmt, edge *taken_edge_p, tree *output_p) |
41511585 | 2325 | { |
41511585 | 2326 | tree def; |
2327 | ssa_op_iter iter; | |
4ee9c684 | 2328 | |
41511585 | 2329 | if (dump_file && (dump_flags & TDF_DETAILS)) |
4ee9c684 | 2330 | { |
88dbf20f | 2331 | fprintf (dump_file, "\nVisiting statement:\n"); |
75a70cf9 | 2332 | print_gimple_stmt (dump_file, stmt, 0, dump_flags); |
4ee9c684 | 2333 | } |
4ee9c684 | 2334 | |
75a70cf9 | 2335 | switch (gimple_code (stmt)) |
4ee9c684 | 2336 | { |
75a70cf9 | 2337 | case GIMPLE_ASSIGN: |
2338 | /* If the statement is an assignment that produces a single | |
2339 | output value, evaluate its RHS to see if the lattice value of | |
2340 | its output has changed. */ | |
2341 | return visit_assignment (stmt, output_p); | |
2342 | ||
2343 | case GIMPLE_CALL: | |
2344 | /* A value-returning call also performs an assignment. */ | |
2345 | if (gimple_call_lhs (stmt) != NULL_TREE) | |
2346 | return visit_assignment (stmt, output_p); | |
2347 | break; | |
2348 | ||
2349 | case GIMPLE_COND: | |
2350 | case GIMPLE_SWITCH: | |
2351 | /* If STMT is a conditional branch, see if we can determine | |
2352 | which branch will be taken. */ | |
2353 | /* FIXME. It appears that we should be able to optimize | |
2354 | computed GOTOs here as well. */ | |
2355 | return visit_cond_stmt (stmt, taken_edge_p); | |
2356 | ||
2357 | default: | |
2358 | break; | |
4ee9c684 | 2359 | } |
4ee9c684 | 2360 | |
41511585 | 2361 | /* Any other kind of statement is not interesting for constant |
2362 | propagation and, therefore, not worth simulating. */ | |
41511585 | 2363 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2364 | fprintf (dump_file, "No interesting values produced. Marked VARYING.\n"); | |
4ee9c684 | 2365 | |
41511585 | 2366 | /* Definitions made by statements other than assignments to |
2367 | SSA_NAMEs represent unknown modifications to their outputs. | |
2368 | Mark them VARYING. */ | |
88dbf20f | 2369 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS) |
2370 | { | |
9908fe4d | 2371 | ccp_prop_value_t v = { VARYING, NULL_TREE, -1 }; |
88dbf20f | 2372 | set_lattice_value (def, v); |
2373 | } | |
4ee9c684 | 2374 | |
41511585 | 2375 | return SSA_PROP_VARYING; |
2376 | } | |
4ee9c684 | 2377 | |
4ee9c684 | 2378 | |
88dbf20f | 2379 | /* Main entry point for SSA Conditional Constant Propagation. */ |
41511585 | 2380 | |
33a34f1e | 2381 | static unsigned int |
61207d43 | 2382 | do_ssa_ccp (void) |
41511585 | 2383 | { |
582a80ed | 2384 | unsigned int todo = 0; |
2385 | calculate_dominance_info (CDI_DOMINATORS); | |
41511585 | 2386 | ccp_initialize (); |
2387 | ssa_propagate (ccp_visit_stmt, ccp_visit_phi_node); | |
33a34f1e | 2388 | if (ccp_finalize ()) |
560965e9 | 2389 | todo = (TODO_cleanup_cfg | TODO_update_ssa); |
582a80ed | 2390 | free_dominance_info (CDI_DOMINATORS); |
2391 | return todo; | |
4ee9c684 | 2392 | } |
2393 | ||
5664499b | 2394 | |
cbe8bda8 | 2395 | namespace { |
2396 | ||
2397 | const pass_data pass_data_ccp = | |
41511585 | 2398 | { |
cbe8bda8 | 2399 | GIMPLE_PASS, /* type */ |
2400 | "ccp", /* name */ | |
2401 | OPTGROUP_NONE, /* optinfo_flags */ | |
cbe8bda8 | 2402 | TV_TREE_CCP, /* tv_id */ |
2403 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
2404 | 0, /* properties_provided */ | |
2405 | 0, /* properties_destroyed */ | |
2406 | 0, /* todo_flags_start */ | |
8b88439e | 2407 | TODO_update_address_taken, /* todo_flags_finish */ |
41511585 | 2408 | }; |
4ee9c684 | 2409 | |
cbe8bda8 | 2410 | class pass_ccp : public gimple_opt_pass |
2411 | { | |
2412 | public: | |
9af5ce0c | 2413 | pass_ccp (gcc::context *ctxt) |
2414 | : gimple_opt_pass (pass_data_ccp, ctxt) | |
cbe8bda8 | 2415 | {} |
2416 | ||
2417 | /* opt_pass methods: */ | |
ae84f584 | 2418 | opt_pass * clone () { return new pass_ccp (m_ctxt); } |
31315c24 | 2419 | virtual bool gate (function *) { return flag_tree_ccp != 0; } |
65b0537f | 2420 | virtual unsigned int execute (function *) { return do_ssa_ccp (); } |
cbe8bda8 | 2421 | |
2422 | }; // class pass_ccp | |
2423 | ||
2424 | } // anon namespace | |
2425 | ||
2426 | gimple_opt_pass * | |
2427 | make_pass_ccp (gcc::context *ctxt) | |
2428 | { | |
2429 | return new pass_ccp (ctxt); | |
2430 | } | |
2431 | ||
4ee9c684 | 2432 | |
75a70cf9 | 2433 | |
bdd0e199 | 2434 | /* Try to optimize out __builtin_stack_restore. Optimize it out |
2435 | if there is another __builtin_stack_restore in the same basic | |
2436 | block and no calls or ASM_EXPRs are in between, or if this block's | |
2437 | only outgoing edge is to EXIT_BLOCK and there are no calls or | |
2438 | ASM_EXPRs after this __builtin_stack_restore. */ | |
2439 | ||
2440 | static tree | |
75a70cf9 | 2441 | optimize_stack_restore (gimple_stmt_iterator i) |
bdd0e199 | 2442 | { |
6ea999da | 2443 | tree callee; |
2444 | gimple stmt; | |
75a70cf9 | 2445 | |
2446 | basic_block bb = gsi_bb (i); | |
2447 | gimple call = gsi_stmt (i); | |
bdd0e199 | 2448 | |
75a70cf9 | 2449 | if (gimple_code (call) != GIMPLE_CALL |
2450 | || gimple_call_num_args (call) != 1 | |
2451 | || TREE_CODE (gimple_call_arg (call, 0)) != SSA_NAME | |
2452 | || !POINTER_TYPE_P (TREE_TYPE (gimple_call_arg (call, 0)))) | |
bdd0e199 | 2453 | return NULL_TREE; |
2454 | ||
75a70cf9 | 2455 | for (gsi_next (&i); !gsi_end_p (i); gsi_next (&i)) |
bdd0e199 | 2456 | { |
75a70cf9 | 2457 | stmt = gsi_stmt (i); |
2458 | if (gimple_code (stmt) == GIMPLE_ASM) | |
bdd0e199 | 2459 | return NULL_TREE; |
75a70cf9 | 2460 | if (gimple_code (stmt) != GIMPLE_CALL) |
bdd0e199 | 2461 | continue; |
2462 | ||
75a70cf9 | 2463 | callee = gimple_call_fndecl (stmt); |
c40a6f90 | 2464 | if (!callee |
2465 | || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL | |
2466 | /* All regular builtins are ok, just obviously not alloca. */ | |
581bf1c2 | 2467 | || DECL_FUNCTION_CODE (callee) == BUILT_IN_ALLOCA |
2468 | || DECL_FUNCTION_CODE (callee) == BUILT_IN_ALLOCA_WITH_ALIGN) | |
bdd0e199 | 2469 | return NULL_TREE; |
2470 | ||
2471 | if (DECL_FUNCTION_CODE (callee) == BUILT_IN_STACK_RESTORE) | |
6ea999da | 2472 | goto second_stack_restore; |
bdd0e199 | 2473 | } |
2474 | ||
6ea999da | 2475 | if (!gsi_end_p (i)) |
bdd0e199 | 2476 | return NULL_TREE; |
2477 | ||
6ea999da | 2478 | /* Allow one successor of the exit block, or zero successors. */ |
2479 | switch (EDGE_COUNT (bb->succs)) | |
2480 | { | |
2481 | case 0: | |
2482 | break; | |
2483 | case 1: | |
34154e27 | 2484 | if (single_succ_edge (bb)->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
6ea999da | 2485 | return NULL_TREE; |
2486 | break; | |
2487 | default: | |
2488 | return NULL_TREE; | |
2489 | } | |
2490 | second_stack_restore: | |
bdd0e199 | 2491 | |
6ea999da | 2492 | /* If there's exactly one use, then zap the call to __builtin_stack_save. |
2493 | If there are multiple uses, then the last one should remove the call. | |
2494 | In any case, whether the call to __builtin_stack_save can be removed | |
2495 | or not is irrelevant to removing the call to __builtin_stack_restore. */ | |
2496 | if (has_single_use (gimple_call_arg (call, 0))) | |
2497 | { | |
2498 | gimple stack_save = SSA_NAME_DEF_STMT (gimple_call_arg (call, 0)); | |
2499 | if (is_gimple_call (stack_save)) | |
2500 | { | |
2501 | callee = gimple_call_fndecl (stack_save); | |
2502 | if (callee | |
2503 | && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL | |
2504 | && DECL_FUNCTION_CODE (callee) == BUILT_IN_STACK_SAVE) | |
2505 | { | |
2506 | gimple_stmt_iterator stack_save_gsi; | |
2507 | tree rhs; | |
bdd0e199 | 2508 | |
6ea999da | 2509 | stack_save_gsi = gsi_for_stmt (stack_save); |
2510 | rhs = build_int_cst (TREE_TYPE (gimple_call_arg (call, 0)), 0); | |
2511 | update_call_from_tree (&stack_save_gsi, rhs); | |
2512 | } | |
2513 | } | |
2514 | } | |
bdd0e199 | 2515 | |
75a70cf9 | 2516 | /* No effect, so the statement will be deleted. */ |
bdd0e199 | 2517 | return integer_zero_node; |
2518 | } | |
75a70cf9 | 2519 | |
8a58ed0a | 2520 | /* If va_list type is a simple pointer and nothing special is needed, |
2521 | optimize __builtin_va_start (&ap, 0) into ap = __builtin_next_arg (0), | |
2522 | __builtin_va_end (&ap) out as NOP and __builtin_va_copy into a simple | |
2523 | pointer assignment. */ | |
2524 | ||
2525 | static tree | |
75a70cf9 | 2526 | optimize_stdarg_builtin (gimple call) |
8a58ed0a | 2527 | { |
5f57a8b1 | 2528 | tree callee, lhs, rhs, cfun_va_list; |
8a58ed0a | 2529 | bool va_list_simple_ptr; |
389dd41b | 2530 | location_t loc = gimple_location (call); |
8a58ed0a | 2531 | |
75a70cf9 | 2532 | if (gimple_code (call) != GIMPLE_CALL) |
8a58ed0a | 2533 | return NULL_TREE; |
2534 | ||
75a70cf9 | 2535 | callee = gimple_call_fndecl (call); |
5f57a8b1 | 2536 | |
2537 | cfun_va_list = targetm.fn_abi_va_list (callee); | |
2538 | va_list_simple_ptr = POINTER_TYPE_P (cfun_va_list) | |
2539 | && (TREE_TYPE (cfun_va_list) == void_type_node | |
2540 | || TREE_TYPE (cfun_va_list) == char_type_node); | |
2541 | ||
8a58ed0a | 2542 | switch (DECL_FUNCTION_CODE (callee)) |
2543 | { | |
2544 | case BUILT_IN_VA_START: | |
2545 | if (!va_list_simple_ptr | |
2546 | || targetm.expand_builtin_va_start != NULL | |
e7ed5dd7 | 2547 | || !builtin_decl_explicit_p (BUILT_IN_NEXT_ARG)) |
8a58ed0a | 2548 | return NULL_TREE; |
2549 | ||
75a70cf9 | 2550 | if (gimple_call_num_args (call) != 2) |
8a58ed0a | 2551 | return NULL_TREE; |
2552 | ||
75a70cf9 | 2553 | lhs = gimple_call_arg (call, 0); |
8a58ed0a | 2554 | if (!POINTER_TYPE_P (TREE_TYPE (lhs)) |
2555 | || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs))) | |
5f57a8b1 | 2556 | != TYPE_MAIN_VARIANT (cfun_va_list)) |
8a58ed0a | 2557 | return NULL_TREE; |
48e1416a | 2558 | |
389dd41b | 2559 | lhs = build_fold_indirect_ref_loc (loc, lhs); |
b9a16870 | 2560 | rhs = build_call_expr_loc (loc, builtin_decl_explicit (BUILT_IN_NEXT_ARG), |
75a70cf9 | 2561 | 1, integer_zero_node); |
389dd41b | 2562 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); |
8a58ed0a | 2563 | return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs); |
2564 | ||
2565 | case BUILT_IN_VA_COPY: | |
2566 | if (!va_list_simple_ptr) | |
2567 | return NULL_TREE; | |
2568 | ||
75a70cf9 | 2569 | if (gimple_call_num_args (call) != 2) |
8a58ed0a | 2570 | return NULL_TREE; |
2571 | ||
75a70cf9 | 2572 | lhs = gimple_call_arg (call, 0); |
8a58ed0a | 2573 | if (!POINTER_TYPE_P (TREE_TYPE (lhs)) |
2574 | || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs))) | |
5f57a8b1 | 2575 | != TYPE_MAIN_VARIANT (cfun_va_list)) |
8a58ed0a | 2576 | return NULL_TREE; |
2577 | ||
389dd41b | 2578 | lhs = build_fold_indirect_ref_loc (loc, lhs); |
75a70cf9 | 2579 | rhs = gimple_call_arg (call, 1); |
8a58ed0a | 2580 | if (TYPE_MAIN_VARIANT (TREE_TYPE (rhs)) |
5f57a8b1 | 2581 | != TYPE_MAIN_VARIANT (cfun_va_list)) |
8a58ed0a | 2582 | return NULL_TREE; |
2583 | ||
389dd41b | 2584 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); |
8a58ed0a | 2585 | return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs); |
2586 | ||
2587 | case BUILT_IN_VA_END: | |
75a70cf9 | 2588 | /* No effect, so the statement will be deleted. */ |
8a58ed0a | 2589 | return integer_zero_node; |
2590 | ||
2591 | default: | |
2592 | gcc_unreachable (); | |
2593 | } | |
2594 | } | |
75a70cf9 | 2595 | |
f87df69a | 2596 | /* Attemp to make the block of __builtin_unreachable I unreachable by changing |
2597 | the incoming jumps. Return true if at least one jump was changed. */ | |
2598 | ||
2599 | static bool | |
2600 | optimize_unreachable (gimple_stmt_iterator i) | |
2601 | { | |
2602 | basic_block bb = gsi_bb (i); | |
2603 | gimple_stmt_iterator gsi; | |
2604 | gimple stmt; | |
2605 | edge_iterator ei; | |
2606 | edge e; | |
2607 | bool ret; | |
2608 | ||
f6b540af | 2609 | if (flag_sanitize & SANITIZE_UNREACHABLE) |
2610 | return false; | |
2611 | ||
f87df69a | 2612 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
2613 | { | |
2614 | stmt = gsi_stmt (gsi); | |
2615 | ||
2616 | if (is_gimple_debug (stmt)) | |
2617 | continue; | |
2618 | ||
1a91d914 | 2619 | if (glabel *label_stmt = dyn_cast <glabel *> (stmt)) |
f87df69a | 2620 | { |
2621 | /* Verify we do not need to preserve the label. */ | |
1a91d914 | 2622 | if (FORCED_LABEL (gimple_label_label (label_stmt))) |
f87df69a | 2623 | return false; |
2624 | ||
2625 | continue; | |
2626 | } | |
2627 | ||
2628 | /* Only handle the case that __builtin_unreachable is the first statement | |
2629 | in the block. We rely on DCE to remove stmts without side-effects | |
2630 | before __builtin_unreachable. */ | |
2631 | if (gsi_stmt (gsi) != gsi_stmt (i)) | |
2632 | return false; | |
2633 | } | |
2634 | ||
2635 | ret = false; | |
2636 | FOR_EACH_EDGE (e, ei, bb->preds) | |
2637 | { | |
2638 | gsi = gsi_last_bb (e->src); | |
522f73a1 | 2639 | if (gsi_end_p (gsi)) |
2640 | continue; | |
f87df69a | 2641 | |
522f73a1 | 2642 | stmt = gsi_stmt (gsi); |
1a91d914 | 2643 | if (gcond *cond_stmt = dyn_cast <gcond *> (stmt)) |
f87df69a | 2644 | { |
2645 | if (e->flags & EDGE_TRUE_VALUE) | |
1a91d914 | 2646 | gimple_cond_make_false (cond_stmt); |
f87df69a | 2647 | else if (e->flags & EDGE_FALSE_VALUE) |
1a91d914 | 2648 | gimple_cond_make_true (cond_stmt); |
f87df69a | 2649 | else |
2650 | gcc_unreachable (); | |
1a91d914 | 2651 | update_stmt (cond_stmt); |
f87df69a | 2652 | } |
2653 | else | |
2654 | { | |
2655 | /* Todo: handle other cases, f.i. switch statement. */ | |
2656 | continue; | |
2657 | } | |
2658 | ||
2659 | ret = true; | |
2660 | } | |
2661 | ||
2662 | return ret; | |
2663 | } | |
2664 | ||
4ee9c684 | 2665 | /* A simple pass that attempts to fold all builtin functions. This pass |
2666 | is run after we've propagated as many constants as we can. */ | |
2667 | ||
65b0537f | 2668 | namespace { |
2669 | ||
2670 | const pass_data pass_data_fold_builtins = | |
2671 | { | |
2672 | GIMPLE_PASS, /* type */ | |
2673 | "fab", /* name */ | |
2674 | OPTGROUP_NONE, /* optinfo_flags */ | |
65b0537f | 2675 | TV_NONE, /* tv_id */ |
2676 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
2677 | 0, /* properties_provided */ | |
2678 | 0, /* properties_destroyed */ | |
2679 | 0, /* todo_flags_start */ | |
8b88439e | 2680 | TODO_update_ssa, /* todo_flags_finish */ |
65b0537f | 2681 | }; |
2682 | ||
2683 | class pass_fold_builtins : public gimple_opt_pass | |
2684 | { | |
2685 | public: | |
2686 | pass_fold_builtins (gcc::context *ctxt) | |
2687 | : gimple_opt_pass (pass_data_fold_builtins, ctxt) | |
2688 | {} | |
2689 | ||
2690 | /* opt_pass methods: */ | |
2691 | opt_pass * clone () { return new pass_fold_builtins (m_ctxt); } | |
2692 | virtual unsigned int execute (function *); | |
2693 | ||
2694 | }; // class pass_fold_builtins | |
2695 | ||
2696 | unsigned int | |
2697 | pass_fold_builtins::execute (function *fun) | |
4ee9c684 | 2698 | { |
b36237eb | 2699 | bool cfg_changed = false; |
4ee9c684 | 2700 | basic_block bb; |
b1b7c0c4 | 2701 | unsigned int todoflags = 0; |
48e1416a | 2702 | |
65b0537f | 2703 | FOR_EACH_BB_FN (bb, fun) |
4ee9c684 | 2704 | { |
75a70cf9 | 2705 | gimple_stmt_iterator i; |
2706 | for (i = gsi_start_bb (bb); !gsi_end_p (i); ) | |
4ee9c684 | 2707 | { |
75a70cf9 | 2708 | gimple stmt, old_stmt; |
40a3eb84 | 2709 | tree callee; |
0a39fd54 | 2710 | enum built_in_function fcode; |
4ee9c684 | 2711 | |
75a70cf9 | 2712 | stmt = gsi_stmt (i); |
2713 | ||
2714 | if (gimple_code (stmt) != GIMPLE_CALL) | |
0a39fd54 | 2715 | { |
896a0c42 | 2716 | /* Remove all *ssaname_N ={v} {CLOBBER}; stmts, |
2717 | after the last GIMPLE DSE they aren't needed and might | |
2718 | unnecessarily keep the SSA_NAMEs live. */ | |
2719 | if (gimple_clobber_p (stmt)) | |
2720 | { | |
2721 | tree lhs = gimple_assign_lhs (stmt); | |
2722 | if (TREE_CODE (lhs) == MEM_REF | |
2723 | && TREE_CODE (TREE_OPERAND (lhs, 0)) == SSA_NAME) | |
2724 | { | |
2725 | unlink_stmt_vdef (stmt); | |
2726 | gsi_remove (&i, true); | |
2727 | release_defs (stmt); | |
2728 | continue; | |
2729 | } | |
2730 | } | |
75a70cf9 | 2731 | gsi_next (&i); |
0a39fd54 | 2732 | continue; |
2733 | } | |
40a3eb84 | 2734 | |
75a70cf9 | 2735 | callee = gimple_call_fndecl (stmt); |
4ee9c684 | 2736 | if (!callee || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL) |
0a39fd54 | 2737 | { |
75a70cf9 | 2738 | gsi_next (&i); |
0a39fd54 | 2739 | continue; |
2740 | } | |
5a4b7e1e | 2741 | |
40a3eb84 | 2742 | fcode = DECL_FUNCTION_CODE (callee); |
2743 | if (fold_stmt (&i)) | |
2744 | ; | |
2745 | else | |
2746 | { | |
2747 | tree result = NULL_TREE; | |
2748 | switch (DECL_FUNCTION_CODE (callee)) | |
2749 | { | |
2750 | case BUILT_IN_CONSTANT_P: | |
2751 | /* Resolve __builtin_constant_p. If it hasn't been | |
2752 | folded to integer_one_node by now, it's fairly | |
2753 | certain that the value simply isn't constant. */ | |
2754 | result = integer_zero_node; | |
2755 | break; | |
5a4b7e1e | 2756 | |
40a3eb84 | 2757 | case BUILT_IN_ASSUME_ALIGNED: |
2758 | /* Remove __builtin_assume_aligned. */ | |
2759 | result = gimple_call_arg (stmt, 0); | |
2760 | break; | |
4ee9c684 | 2761 | |
40a3eb84 | 2762 | case BUILT_IN_STACK_RESTORE: |
2763 | result = optimize_stack_restore (i); | |
2764 | if (result) | |
2765 | break; | |
2766 | gsi_next (&i); | |
2767 | continue; | |
fca0886c | 2768 | |
40a3eb84 | 2769 | case BUILT_IN_UNREACHABLE: |
2770 | if (optimize_unreachable (i)) | |
2771 | cfg_changed = true; | |
8a58ed0a | 2772 | break; |
8a58ed0a | 2773 | |
40a3eb84 | 2774 | case BUILT_IN_VA_START: |
2775 | case BUILT_IN_VA_END: | |
2776 | case BUILT_IN_VA_COPY: | |
2777 | /* These shouldn't be folded before pass_stdarg. */ | |
2778 | result = optimize_stdarg_builtin (stmt); | |
2779 | if (result) | |
2780 | break; | |
2781 | /* FALLTHRU */ | |
f87df69a | 2782 | |
40a3eb84 | 2783 | default:; |
2784 | } | |
bdd0e199 | 2785 | |
40a3eb84 | 2786 | if (!result) |
2787 | { | |
2788 | gsi_next (&i); | |
2789 | continue; | |
2790 | } | |
4ee9c684 | 2791 | |
40a3eb84 | 2792 | if (!update_call_from_tree (&i, result)) |
2793 | gimplify_and_update_call_from_tree (&i, result); | |
2794 | } | |
2795 | ||
2796 | todoflags |= TODO_update_address_taken; | |
f87df69a | 2797 | |
4ee9c684 | 2798 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2799 | { | |
2800 | fprintf (dump_file, "Simplified\n "); | |
75a70cf9 | 2801 | print_gimple_stmt (dump_file, stmt, 0, dump_flags); |
4ee9c684 | 2802 | } |
2803 | ||
75a70cf9 | 2804 | old_stmt = stmt; |
75a70cf9 | 2805 | stmt = gsi_stmt (i); |
4c5fd53c | 2806 | update_stmt (stmt); |
de6ed584 | 2807 | |
75a70cf9 | 2808 | if (maybe_clean_or_replace_eh_stmt (old_stmt, stmt) |
2809 | && gimple_purge_dead_eh_edges (bb)) | |
b36237eb | 2810 | cfg_changed = true; |
4ee9c684 | 2811 | |
2812 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2813 | { | |
2814 | fprintf (dump_file, "to\n "); | |
75a70cf9 | 2815 | print_gimple_stmt (dump_file, stmt, 0, dump_flags); |
4ee9c684 | 2816 | fprintf (dump_file, "\n"); |
2817 | } | |
0a39fd54 | 2818 | |
2819 | /* Retry the same statement if it changed into another | |
2820 | builtin, there might be new opportunities now. */ | |
75a70cf9 | 2821 | if (gimple_code (stmt) != GIMPLE_CALL) |
0a39fd54 | 2822 | { |
75a70cf9 | 2823 | gsi_next (&i); |
0a39fd54 | 2824 | continue; |
2825 | } | |
75a70cf9 | 2826 | callee = gimple_call_fndecl (stmt); |
0a39fd54 | 2827 | if (!callee |
75a70cf9 | 2828 | || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL |
0a39fd54 | 2829 | || DECL_FUNCTION_CODE (callee) == fcode) |
75a70cf9 | 2830 | gsi_next (&i); |
4ee9c684 | 2831 | } |
2832 | } | |
48e1416a | 2833 | |
b36237eb | 2834 | /* Delete unreachable blocks. */ |
b1b7c0c4 | 2835 | if (cfg_changed) |
2836 | todoflags |= TODO_cleanup_cfg; | |
48e1416a | 2837 | |
b1b7c0c4 | 2838 | return todoflags; |
4ee9c684 | 2839 | } |
2840 | ||
cbe8bda8 | 2841 | } // anon namespace |
2842 | ||
2843 | gimple_opt_pass * | |
2844 | make_pass_fold_builtins (gcc::context *ctxt) | |
2845 | { | |
2846 | return new pass_fold_builtins (ctxt); | |
2847 | } |