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6de9cd9a | 1 | /* Conditional constant propagation pass for the GNU compiler. |
23a5b65a | 2 | Copyright (C) 2000-2014 Free Software Foundation, Inc. |
6de9cd9a DN |
3 | Adapted from original RTL SSA-CCP by Daniel Berlin <dberlin@dberlin.org> |
4 | Adapted to GIMPLE trees by Diego Novillo <dnovillo@redhat.com> | |
5 | ||
6 | This file is part of GCC. | |
b8698a0f | 7 | |
6de9cd9a DN |
8 | GCC is free software; you can redistribute it and/or modify it |
9 | under the terms of the GNU General Public License as published by the | |
9dcd6f09 | 10 | Free Software Foundation; either version 3, or (at your option) any |
6de9cd9a | 11 | later version. |
b8698a0f | 12 | |
6de9cd9a DN |
13 | GCC is distributed in the hope that it will be useful, but WITHOUT |
14 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
16 | for more details. | |
b8698a0f | 17 | |
6de9cd9a | 18 | You should have received a copy of the GNU General Public License |
9dcd6f09 NC |
19 | along with GCC; see the file COPYING3. If not see |
20 | <http://www.gnu.org/licenses/>. */ | |
6de9cd9a | 21 | |
0bca51f0 DN |
22 | /* Conditional constant propagation (CCP) is based on the SSA |
23 | propagation engine (tree-ssa-propagate.c). Constant assignments of | |
24 | the form VAR = CST are propagated from the assignments into uses of | |
25 | VAR, which in turn may generate new constants. The simulation uses | |
26 | a four level lattice to keep track of constant values associated | |
27 | with SSA names. Given an SSA name V_i, it may take one of the | |
28 | following values: | |
29 | ||
106dec71 ZD |
30 | UNINITIALIZED -> the initial state of the value. This value |
31 | is replaced with a correct initial value | |
32 | the first time the value is used, so the | |
33 | rest of the pass does not need to care about | |
34 | it. Using this value simplifies initialization | |
35 | of the pass, and prevents us from needlessly | |
36 | scanning statements that are never reached. | |
0bca51f0 DN |
37 | |
38 | UNDEFINED -> V_i is a local variable whose definition | |
39 | has not been processed yet. Therefore we | |
40 | don't yet know if its value is a constant | |
41 | or not. | |
42 | ||
43 | CONSTANT -> V_i has been found to hold a constant | |
44 | value C. | |
45 | ||
46 | VARYING -> V_i cannot take a constant value, or if it | |
47 | does, it is not possible to determine it | |
48 | at compile time. | |
49 | ||
50 | The core of SSA-CCP is in ccp_visit_stmt and ccp_visit_phi_node: | |
51 | ||
52 | 1- In ccp_visit_stmt, we are interested in assignments whose RHS | |
53 | evaluates into a constant and conditional jumps whose predicate | |
54 | evaluates into a boolean true or false. When an assignment of | |
55 | the form V_i = CONST is found, V_i's lattice value is set to | |
56 | CONSTANT and CONST is associated with it. This causes the | |
57 | propagation engine to add all the SSA edges coming out the | |
58 | assignment into the worklists, so that statements that use V_i | |
59 | can be visited. | |
60 | ||
61 | If the statement is a conditional with a constant predicate, we | |
62 | mark the outgoing edges as executable or not executable | |
63 | depending on the predicate's value. This is then used when | |
64 | visiting PHI nodes to know when a PHI argument can be ignored. | |
b8698a0f | 65 | |
0bca51f0 DN |
66 | |
67 | 2- In ccp_visit_phi_node, if all the PHI arguments evaluate to the | |
68 | same constant C, then the LHS of the PHI is set to C. This | |
69 | evaluation is known as the "meet operation". Since one of the | |
70 | goals of this evaluation is to optimistically return constant | |
71 | values as often as possible, it uses two main short cuts: | |
72 | ||
73 | - If an argument is flowing in through a non-executable edge, it | |
74 | is ignored. This is useful in cases like this: | |
75 | ||
76 | if (PRED) | |
77 | a_9 = 3; | |
78 | else | |
79 | a_10 = 100; | |
80 | a_11 = PHI (a_9, a_10) | |
81 | ||
82 | If PRED is known to always evaluate to false, then we can | |
83 | assume that a_11 will always take its value from a_10, meaning | |
84 | that instead of consider it VARYING (a_9 and a_10 have | |
85 | different values), we can consider it CONSTANT 100. | |
86 | ||
87 | - If an argument has an UNDEFINED value, then it does not affect | |
88 | the outcome of the meet operation. If a variable V_i has an | |
89 | UNDEFINED value, it means that either its defining statement | |
90 | hasn't been visited yet or V_i has no defining statement, in | |
91 | which case the original symbol 'V' is being used | |
92 | uninitialized. Since 'V' is a local variable, the compiler | |
93 | may assume any initial value for it. | |
94 | ||
95 | ||
96 | After propagation, every variable V_i that ends up with a lattice | |
97 | value of CONSTANT will have the associated constant value in the | |
98 | array CONST_VAL[i].VALUE. That is fed into substitute_and_fold for | |
99 | final substitution and folding. | |
100 | ||
807e902e KZ |
101 | This algorithm uses wide-ints at the max precision of the target. |
102 | This means that, with one uninteresting exception, variables with | |
103 | UNSIGNED types never go to VARYING because the bits above the | |
104 | precision of the type of the variable are always zero. The | |
105 | uninteresting case is a variable of UNSIGNED type that has the | |
106 | maximum precision of the target. Such variables can go to VARYING, | |
107 | but this causes no loss of infomation since these variables will | |
108 | never be extended. | |
109 | ||
6de9cd9a DN |
110 | References: |
111 | ||
112 | Constant propagation with conditional branches, | |
113 | Wegman and Zadeck, ACM TOPLAS 13(2):181-210. | |
114 | ||
115 | Building an Optimizing Compiler, | |
116 | Robert Morgan, Butterworth-Heinemann, 1998, Section 8.9. | |
117 | ||
118 | Advanced Compiler Design and Implementation, | |
119 | Steven Muchnick, Morgan Kaufmann, 1997, Section 12.6 */ | |
120 | ||
121 | #include "config.h" | |
122 | #include "system.h" | |
123 | #include "coretypes.h" | |
124 | #include "tm.h" | |
6de9cd9a | 125 | #include "tree.h" |
d8a2d370 | 126 | #include "stor-layout.h" |
750628d8 | 127 | #include "flags.h" |
6de9cd9a | 128 | #include "tm_p.h" |
60393bbc AM |
129 | #include "predict.h" |
130 | #include "vec.h" | |
83685514 AM |
131 | #include "hashtab.h" |
132 | #include "hash-set.h" | |
83685514 AM |
133 | #include "machmode.h" |
134 | #include "hard-reg-set.h" | |
135 | #include "input.h" | |
750628d8 | 136 | #include "function.h" |
60393bbc AM |
137 | #include "dominance.h" |
138 | #include "cfg.h" | |
139 | #include "basic-block.h" | |
cf835838 | 140 | #include "gimple-pretty-print.h" |
2fb9a547 AM |
141 | #include "hash-table.h" |
142 | #include "tree-ssa-alias.h" | |
143 | #include "internal-fn.h" | |
144 | #include "gimple-fold.h" | |
145 | #include "tree-eh.h" | |
146 | #include "gimple-expr.h" | |
147 | #include "is-a.h" | |
18f429e2 | 148 | #include "gimple.h" |
45b0be94 | 149 | #include "gimplify.h" |
5be5c238 | 150 | #include "gimple-iterator.h" |
442b4905 AM |
151 | #include "gimple-ssa.h" |
152 | #include "tree-cfg.h" | |
153 | #include "tree-phinodes.h" | |
154 | #include "ssa-iterators.h" | |
d8a2d370 | 155 | #include "stringpool.h" |
442b4905 | 156 | #include "tree-ssanames.h" |
6de9cd9a | 157 | #include "tree-pass.h" |
750628d8 | 158 | #include "tree-ssa-propagate.h" |
53a8f709 | 159 | #include "value-prof.h" |
750628d8 | 160 | #include "langhooks.h" |
ae3df618 | 161 | #include "target.h" |
718f9c0f | 162 | #include "diagnostic-core.h" |
74fe548b | 163 | #include "dbgcnt.h" |
1fed1006 | 164 | #include "params.h" |
807e902e | 165 | #include "wide-int-print.h" |
9b2b7279 | 166 | #include "builtins.h" |
d5e254e1 | 167 | #include "tree-chkp.h" |
6de9cd9a DN |
168 | |
169 | ||
170 | /* Possible lattice values. */ | |
171 | typedef enum | |
172 | { | |
106dec71 | 173 | UNINITIALIZED, |
6de9cd9a DN |
174 | UNDEFINED, |
175 | CONSTANT, | |
176 | VARYING | |
0bca51f0 | 177 | } ccp_lattice_t; |
6de9cd9a | 178 | |
11478306 | 179 | struct ccp_prop_value_t { |
455e6d5b RG |
180 | /* Lattice value. */ |
181 | ccp_lattice_t lattice_val; | |
182 | ||
183 | /* Propagated value. */ | |
184 | tree value; | |
0b4b14ac | 185 | |
807e902e KZ |
186 | /* Mask that applies to the propagated value during CCP. For X |
187 | with a CONSTANT lattice value X & ~mask == value & ~mask. The | |
188 | zero bits in the mask cover constant values. The ones mean no | |
189 | information. */ | |
190 | widest_int mask; | |
455e6d5b RG |
191 | }; |
192 | ||
0bca51f0 DN |
193 | /* Array of propagated constant values. After propagation, |
194 | CONST_VAL[I].VALUE holds the constant value for SSA_NAME(I). If | |
195 | the constant is held in an SSA name representing a memory store | |
38635499 DN |
196 | (i.e., a VDEF), CONST_VAL[I].MEM_REF will contain the actual |
197 | memory reference used to store (i.e., the LHS of the assignment | |
198 | doing the store). */ | |
11478306 | 199 | static ccp_prop_value_t *const_val; |
e91c8ed6 | 200 | static unsigned n_const_val; |
6de9cd9a | 201 | |
11478306 | 202 | static void canonicalize_value (ccp_prop_value_t *); |
f61e18ec | 203 | static bool ccp_fold_stmt (gimple_stmt_iterator *); |
25e20805 | 204 | |
0bca51f0 | 205 | /* Dump constant propagation value VAL to file OUTF prefixed by PREFIX. */ |
95eec0d6 DB |
206 | |
207 | static void | |
11478306 | 208 | dump_lattice_value (FILE *outf, const char *prefix, ccp_prop_value_t val) |
95eec0d6 | 209 | { |
750628d8 | 210 | switch (val.lattice_val) |
95eec0d6 | 211 | { |
0bca51f0 DN |
212 | case UNINITIALIZED: |
213 | fprintf (outf, "%sUNINITIALIZED", prefix); | |
214 | break; | |
750628d8 DN |
215 | case UNDEFINED: |
216 | fprintf (outf, "%sUNDEFINED", prefix); | |
217 | break; | |
218 | case VARYING: | |
219 | fprintf (outf, "%sVARYING", prefix); | |
220 | break; | |
750628d8 | 221 | case CONSTANT: |
0b4b14ac | 222 | if (TREE_CODE (val.value) != INTEGER_CST |
807e902e | 223 | || val.mask == 0) |
c38cdd3f EB |
224 | { |
225 | fprintf (outf, "%sCONSTANT ", prefix); | |
226 | print_generic_expr (outf, val.value, dump_flags); | |
227 | } | |
0b4b14ac RG |
228 | else |
229 | { | |
807e902e KZ |
230 | widest_int cval = wi::bit_and_not (wi::to_widest (val.value), |
231 | val.mask); | |
232 | fprintf (outf, "%sCONSTANT ", prefix); | |
233 | print_hex (cval, outf); | |
234 | fprintf (outf, " ("); | |
235 | print_hex (val.mask, outf); | |
236 | fprintf (outf, ")"); | |
0b4b14ac | 237 | } |
750628d8 DN |
238 | break; |
239 | default: | |
1e128c5f | 240 | gcc_unreachable (); |
750628d8 | 241 | } |
95eec0d6 | 242 | } |
6de9cd9a | 243 | |
6de9cd9a | 244 | |
0bca51f0 DN |
245 | /* Print lattice value VAL to stderr. */ |
246 | ||
11478306 | 247 | void debug_lattice_value (ccp_prop_value_t val); |
0bca51f0 | 248 | |
24e47c76 | 249 | DEBUG_FUNCTION void |
11478306 | 250 | debug_lattice_value (ccp_prop_value_t val) |
0bca51f0 DN |
251 | { |
252 | dump_lattice_value (stderr, "", val); | |
253 | fprintf (stderr, "\n"); | |
254 | } | |
6de9cd9a | 255 | |
807e902e KZ |
256 | /* Extend NONZERO_BITS to a full mask, with the upper bits being set. */ |
257 | ||
258 | static widest_int | |
259 | extend_mask (const wide_int &nonzero_bits) | |
260 | { | |
261 | return (wi::mask <widest_int> (wi::get_precision (nonzero_bits), true) | |
262 | | widest_int::from (nonzero_bits, UNSIGNED)); | |
263 | } | |
6de9cd9a | 264 | |
0bca51f0 DN |
265 | /* Compute a default value for variable VAR and store it in the |
266 | CONST_VAL array. The following rules are used to get default | |
267 | values: | |
95eec0d6 | 268 | |
0bca51f0 DN |
269 | 1- Global and static variables that are declared constant are |
270 | considered CONSTANT. | |
271 | ||
272 | 2- Any other value is considered UNDEFINED. This is useful when | |
750628d8 DN |
273 | considering PHI nodes. PHI arguments that are undefined do not |
274 | change the constant value of the PHI node, which allows for more | |
0bca51f0 | 275 | constants to be propagated. |
6de9cd9a | 276 | |
caf55296 | 277 | 3- Variables defined by statements other than assignments and PHI |
0bca51f0 | 278 | nodes are considered VARYING. |
6de9cd9a | 279 | |
caf55296 | 280 | 4- Initial values of variables that are not GIMPLE registers are |
106dec71 | 281 | considered VARYING. */ |
6de9cd9a | 282 | |
11478306 | 283 | static ccp_prop_value_t |
0bca51f0 DN |
284 | get_default_value (tree var) |
285 | { | |
11478306 | 286 | ccp_prop_value_t val = { UNINITIALIZED, NULL_TREE, 0 }; |
e8114fba RG |
287 | gimple stmt; |
288 | ||
289 | stmt = SSA_NAME_DEF_STMT (var); | |
290 | ||
291 | if (gimple_nop_p (stmt)) | |
6de9cd9a | 292 | { |
e8114fba RG |
293 | /* Variables defined by an empty statement are those used |
294 | before being initialized. If VAR is a local variable, we | |
295 | can assume initially that it is UNDEFINED, otherwise we must | |
296 | consider it VARYING. */ | |
ea057359 RG |
297 | if (!virtual_operand_p (var) |
298 | && TREE_CODE (SSA_NAME_VAR (var)) == VAR_DECL) | |
e8114fba RG |
299 | val.lattice_val = UNDEFINED; |
300 | else | |
0b4b14ac RG |
301 | { |
302 | val.lattice_val = VARYING; | |
807e902e | 303 | val.mask = -1; |
c853f62a JJ |
304 | if (flag_tree_bit_ccp) |
305 | { | |
807e902e KZ |
306 | wide_int nonzero_bits = get_nonzero_bits (var); |
307 | if (nonzero_bits != -1) | |
c853f62a JJ |
308 | { |
309 | val.lattice_val = CONSTANT; | |
310 | val.value = build_zero_cst (TREE_TYPE (var)); | |
807e902e | 311 | val.mask = extend_mask (nonzero_bits); |
c853f62a JJ |
312 | } |
313 | } | |
0b4b14ac | 314 | } |
6de9cd9a | 315 | } |
d71ff3fa | 316 | else if (is_gimple_assign (stmt)) |
750628d8 | 317 | { |
e8114fba RG |
318 | tree cst; |
319 | if (gimple_assign_single_p (stmt) | |
320 | && DECL_P (gimple_assign_rhs1 (stmt)) | |
321 | && (cst = get_symbol_constant_value (gimple_assign_rhs1 (stmt)))) | |
0bca51f0 | 322 | { |
e8114fba RG |
323 | val.lattice_val = CONSTANT; |
324 | val.value = cst; | |
0bca51f0 DN |
325 | } |
326 | else | |
d71ff3fa ZZ |
327 | { |
328 | /* Any other variable defined by an assignment is considered | |
329 | UNDEFINED. */ | |
330 | val.lattice_val = UNDEFINED; | |
331 | } | |
332 | } | |
333 | else if ((is_gimple_call (stmt) | |
334 | && gimple_call_lhs (stmt) != NULL_TREE) | |
335 | || gimple_code (stmt) == GIMPLE_PHI) | |
336 | { | |
337 | /* A variable defined by a call or a PHI node is considered | |
338 | UNDEFINED. */ | |
339 | val.lattice_val = UNDEFINED; | |
e8114fba RG |
340 | } |
341 | else | |
342 | { | |
343 | /* Otherwise, VAR will never take on a constant value. */ | |
344 | val.lattice_val = VARYING; | |
807e902e | 345 | val.mask = -1; |
750628d8 | 346 | } |
6de9cd9a | 347 | |
750628d8 DN |
348 | return val; |
349 | } | |
6de9cd9a | 350 | |
6de9cd9a | 351 | |
106dec71 | 352 | /* Get the constant value associated with variable VAR. */ |
6de9cd9a | 353 | |
11478306 | 354 | static inline ccp_prop_value_t * |
106dec71 | 355 | get_value (tree var) |
0bca51f0 | 356 | { |
11478306 | 357 | ccp_prop_value_t *val; |
106dec71 | 358 | |
e91c8ed6 RB |
359 | if (const_val == NULL |
360 | || SSA_NAME_VERSION (var) >= n_const_val) | |
ed97ddc6 RG |
361 | return NULL; |
362 | ||
363 | val = &const_val[SSA_NAME_VERSION (var)]; | |
106dec71 | 364 | if (val->lattice_val == UNINITIALIZED) |
6de9cd9a DN |
365 | *val = get_default_value (var); |
366 | ||
846abd0d | 367 | canonicalize_value (val); |
25e20805 | 368 | |
6de9cd9a DN |
369 | return val; |
370 | } | |
371 | ||
84d77ca6 RG |
372 | /* Return the constant tree value associated with VAR. */ |
373 | ||
374 | static inline tree | |
375 | get_constant_value (tree var) | |
376 | { | |
11478306 | 377 | ccp_prop_value_t *val; |
e196b221 JH |
378 | if (TREE_CODE (var) != SSA_NAME) |
379 | { | |
380 | if (is_gimple_min_invariant (var)) | |
381 | return var; | |
382 | return NULL_TREE; | |
383 | } | |
384 | val = get_value (var); | |
0b4b14ac RG |
385 | if (val |
386 | && val->lattice_val == CONSTANT | |
387 | && (TREE_CODE (val->value) != INTEGER_CST | |
807e902e | 388 | || val->mask == 0)) |
84d77ca6 RG |
389 | return val->value; |
390 | return NULL_TREE; | |
391 | } | |
392 | ||
106dec71 ZD |
393 | /* Sets the value associated with VAR to VARYING. */ |
394 | ||
395 | static inline void | |
396 | set_value_varying (tree var) | |
397 | { | |
11478306 | 398 | ccp_prop_value_t *val = &const_val[SSA_NAME_VERSION (var)]; |
106dec71 ZD |
399 | |
400 | val->lattice_val = VARYING; | |
401 | val->value = NULL_TREE; | |
807e902e | 402 | val->mask = -1; |
106dec71 | 403 | } |
6de9cd9a | 404 | |
bee1d478 | 405 | /* For integer constants, make sure to drop TREE_OVERFLOW. */ |
fbb5445b L |
406 | |
407 | static void | |
11478306 | 408 | canonicalize_value (ccp_prop_value_t *val) |
fbb5445b | 409 | { |
846abd0d RB |
410 | if (val->lattice_val != CONSTANT) |
411 | return; | |
412 | ||
413 | if (TREE_OVERFLOW_P (val->value)) | |
414 | val->value = drop_tree_overflow (val->value); | |
fbb5445b L |
415 | } |
416 | ||
0b4b14ac RG |
417 | /* Return whether the lattice transition is valid. */ |
418 | ||
419 | static bool | |
11478306 | 420 | valid_lattice_transition (ccp_prop_value_t old_val, ccp_prop_value_t new_val) |
0b4b14ac RG |
421 | { |
422 | /* Lattice transitions must always be monotonically increasing in | |
423 | value. */ | |
424 | if (old_val.lattice_val < new_val.lattice_val) | |
425 | return true; | |
426 | ||
427 | if (old_val.lattice_val != new_val.lattice_val) | |
428 | return false; | |
429 | ||
430 | if (!old_val.value && !new_val.value) | |
431 | return true; | |
432 | ||
433 | /* Now both lattice values are CONSTANT. */ | |
434 | ||
95cbf851 RG |
435 | /* Allow transitioning from PHI <&x, not executable> == &x |
436 | to PHI <&x, &y> == common alignment. */ | |
0b4b14ac RG |
437 | if (TREE_CODE (old_val.value) != INTEGER_CST |
438 | && TREE_CODE (new_val.value) == INTEGER_CST) | |
439 | return true; | |
440 | ||
441 | /* Bit-lattices have to agree in the still valid bits. */ | |
442 | if (TREE_CODE (old_val.value) == INTEGER_CST | |
443 | && TREE_CODE (new_val.value) == INTEGER_CST) | |
807e902e KZ |
444 | return (wi::bit_and_not (wi::to_widest (old_val.value), new_val.mask) |
445 | == wi::bit_and_not (wi::to_widest (new_val.value), new_val.mask)); | |
0b4b14ac RG |
446 | |
447 | /* Otherwise constant values have to agree. */ | |
bee1d478 RB |
448 | if (operand_equal_p (old_val.value, new_val.value, 0)) |
449 | return true; | |
450 | ||
451 | /* At least the kinds and types should agree now. */ | |
452 | if (TREE_CODE (old_val.value) != TREE_CODE (new_val.value) | |
453 | || !types_compatible_p (TREE_TYPE (old_val.value), | |
454 | TREE_TYPE (new_val.value))) | |
455 | return false; | |
456 | ||
457 | /* For floats and !HONOR_NANS allow transitions from (partial) NaN | |
458 | to non-NaN. */ | |
459 | tree type = TREE_TYPE (new_val.value); | |
460 | if (SCALAR_FLOAT_TYPE_P (type) | |
461 | && !HONOR_NANS (TYPE_MODE (type))) | |
462 | { | |
463 | if (REAL_VALUE_ISNAN (TREE_REAL_CST (old_val.value))) | |
464 | return true; | |
465 | } | |
466 | else if (VECTOR_FLOAT_TYPE_P (type) | |
467 | && !HONOR_NANS (TYPE_MODE (TREE_TYPE (type)))) | |
468 | { | |
469 | for (unsigned i = 0; i < VECTOR_CST_NELTS (old_val.value); ++i) | |
470 | if (!REAL_VALUE_ISNAN | |
471 | (TREE_REAL_CST (VECTOR_CST_ELT (old_val.value, i))) | |
472 | && !operand_equal_p (VECTOR_CST_ELT (old_val.value, i), | |
473 | VECTOR_CST_ELT (new_val.value, i), 0)) | |
474 | return false; | |
475 | return true; | |
476 | } | |
477 | else if (COMPLEX_FLOAT_TYPE_P (type) | |
478 | && !HONOR_NANS (TYPE_MODE (TREE_TYPE (type)))) | |
479 | { | |
480 | if (!REAL_VALUE_ISNAN (TREE_REAL_CST (TREE_REALPART (old_val.value))) | |
481 | && !operand_equal_p (TREE_REALPART (old_val.value), | |
482 | TREE_REALPART (new_val.value), 0)) | |
483 | return false; | |
484 | if (!REAL_VALUE_ISNAN (TREE_REAL_CST (TREE_IMAGPART (old_val.value))) | |
485 | && !operand_equal_p (TREE_IMAGPART (old_val.value), | |
486 | TREE_IMAGPART (new_val.value), 0)) | |
487 | return false; | |
488 | return true; | |
489 | } | |
490 | return false; | |
0b4b14ac RG |
491 | } |
492 | ||
0bca51f0 DN |
493 | /* Set the value for variable VAR to NEW_VAL. Return true if the new |
494 | value is different from VAR's previous value. */ | |
6de9cd9a | 495 | |
750628d8 | 496 | static bool |
11478306 | 497 | set_lattice_value (tree var, ccp_prop_value_t new_val) |
6de9cd9a | 498 | { |
7a95d078 | 499 | /* We can deal with old UNINITIALIZED values just fine here. */ |
11478306 | 500 | ccp_prop_value_t *old_val = &const_val[SSA_NAME_VERSION (var)]; |
0bca51f0 | 501 | |
846abd0d | 502 | canonicalize_value (&new_val); |
fbb5445b | 503 | |
0b4b14ac RG |
504 | /* We have to be careful to not go up the bitwise lattice |
505 | represented by the mask. | |
506 | ??? This doesn't seem to be the best place to enforce this. */ | |
507 | if (new_val.lattice_val == CONSTANT | |
508 | && old_val->lattice_val == CONSTANT | |
509 | && TREE_CODE (new_val.value) == INTEGER_CST | |
510 | && TREE_CODE (old_val->value) == INTEGER_CST) | |
511 | { | |
807e902e KZ |
512 | widest_int diff = (wi::to_widest (new_val.value) |
513 | ^ wi::to_widest (old_val->value)); | |
27bcd47c | 514 | new_val.mask = new_val.mask | old_val->mask | diff; |
0b4b14ac | 515 | } |
106dec71 | 516 | |
bee1d478 | 517 | gcc_checking_assert (valid_lattice_transition (*old_val, new_val)); |
0bca51f0 | 518 | |
0b4b14ac RG |
519 | /* If *OLD_VAL and NEW_VAL are the same, return false to inform the |
520 | caller that this was a non-transition. */ | |
521 | if (old_val->lattice_val != new_val.lattice_val | |
522 | || (new_val.lattice_val == CONSTANT | |
523 | && TREE_CODE (new_val.value) == INTEGER_CST | |
524 | && (TREE_CODE (old_val->value) != INTEGER_CST | |
27bcd47c | 525 | || new_val.mask != old_val->mask))) |
6de9cd9a | 526 | { |
0b4b14ac RG |
527 | /* ??? We would like to delay creation of INTEGER_CSTs from |
528 | partially constants here. */ | |
529 | ||
750628d8 DN |
530 | if (dump_file && (dump_flags & TDF_DETAILS)) |
531 | { | |
0bca51f0 | 532 | dump_lattice_value (dump_file, "Lattice value changed to ", new_val); |
106dec71 | 533 | fprintf (dump_file, ". Adding SSA edges to worklist.\n"); |
750628d8 DN |
534 | } |
535 | ||
0bca51f0 DN |
536 | *old_val = new_val; |
537 | ||
7a95d078 | 538 | gcc_assert (new_val.lattice_val != UNINITIALIZED); |
106dec71 | 539 | return true; |
6de9cd9a | 540 | } |
750628d8 DN |
541 | |
542 | return false; | |
6de9cd9a DN |
543 | } |
544 | ||
11478306 JH |
545 | static ccp_prop_value_t get_value_for_expr (tree, bool); |
546 | static ccp_prop_value_t bit_value_binop (enum tree_code, tree, tree, tree); | |
807e902e KZ |
547 | static void bit_value_binop_1 (enum tree_code, tree, widest_int *, widest_int *, |
548 | tree, const widest_int &, const widest_int &, | |
549 | tree, const widest_int &, const widest_int &); | |
0b4b14ac | 550 | |
807e902e | 551 | /* Return a widest_int that can be used for bitwise simplifications |
0b4b14ac RG |
552 | from VAL. */ |
553 | ||
807e902e | 554 | static widest_int |
11478306 | 555 | value_to_wide_int (ccp_prop_value_t val) |
0b4b14ac RG |
556 | { |
557 | if (val.value | |
558 | && TREE_CODE (val.value) == INTEGER_CST) | |
807e902e KZ |
559 | return wi::to_widest (val.value); |
560 | ||
561 | return 0; | |
0b4b14ac RG |
562 | } |
563 | ||
564 | /* Return the value for the address expression EXPR based on alignment | |
565 | information. */ | |
7a95d078 | 566 | |
11478306 | 567 | static ccp_prop_value_t |
0b4b14ac RG |
568 | get_value_from_alignment (tree expr) |
569 | { | |
d1f4e15f | 570 | tree type = TREE_TYPE (expr); |
11478306 | 571 | ccp_prop_value_t val; |
d1f4e15f RG |
572 | unsigned HOST_WIDE_INT bitpos; |
573 | unsigned int align; | |
0b4b14ac RG |
574 | |
575 | gcc_assert (TREE_CODE (expr) == ADDR_EXPR); | |
576 | ||
a0969677 | 577 | get_pointer_alignment_1 (expr, &align, &bitpos); |
27bcd47c | 578 | val.mask = (POINTER_TYPE_P (type) || TYPE_UNSIGNED (type) |
807e902e KZ |
579 | ? wi::mask <widest_int> (TYPE_PRECISION (type), false) |
580 | : -1).and_not (align / BITS_PER_UNIT - 1); | |
581 | val.lattice_val = val.mask == -1 ? VARYING : CONSTANT; | |
d1f4e15f | 582 | if (val.lattice_val == CONSTANT) |
807e902e | 583 | val.value = build_int_cstu (type, bitpos / BITS_PER_UNIT); |
0b4b14ac | 584 | else |
d1f4e15f | 585 | val.value = NULL_TREE; |
0b4b14ac RG |
586 | |
587 | return val; | |
588 | } | |
589 | ||
590 | /* Return the value for the tree operand EXPR. If FOR_BITS_P is true | |
591 | return constant bits extracted from alignment information for | |
592 | invariant addresses. */ | |
593 | ||
11478306 | 594 | static ccp_prop_value_t |
0b4b14ac | 595 | get_value_for_expr (tree expr, bool for_bits_p) |
7a95d078 | 596 | { |
11478306 | 597 | ccp_prop_value_t val; |
7a95d078 RG |
598 | |
599 | if (TREE_CODE (expr) == SSA_NAME) | |
0b4b14ac RG |
600 | { |
601 | val = *get_value (expr); | |
602 | if (for_bits_p | |
603 | && val.lattice_val == CONSTANT | |
604 | && TREE_CODE (val.value) == ADDR_EXPR) | |
605 | val = get_value_from_alignment (val.value); | |
606 | } | |
607 | else if (is_gimple_min_invariant (expr) | |
608 | && (!for_bits_p || TREE_CODE (expr) != ADDR_EXPR)) | |
7a95d078 RG |
609 | { |
610 | val.lattice_val = CONSTANT; | |
611 | val.value = expr; | |
807e902e | 612 | val.mask = 0; |
846abd0d | 613 | canonicalize_value (&val); |
7a95d078 | 614 | } |
0b4b14ac RG |
615 | else if (TREE_CODE (expr) == ADDR_EXPR) |
616 | val = get_value_from_alignment (expr); | |
7a95d078 RG |
617 | else |
618 | { | |
619 | val.lattice_val = VARYING; | |
807e902e | 620 | val.mask = -1; |
7a95d078 RG |
621 | val.value = NULL_TREE; |
622 | } | |
7a95d078 RG |
623 | return val; |
624 | } | |
625 | ||
0bca51f0 | 626 | /* Return the likely CCP lattice value for STMT. |
6de9cd9a | 627 | |
750628d8 | 628 | If STMT has no operands, then return CONSTANT. |
6de9cd9a | 629 | |
7f879c96 RG |
630 | Else if undefinedness of operands of STMT cause its value to be |
631 | undefined, then return UNDEFINED. | |
6de9cd9a | 632 | |
750628d8 | 633 | Else if any operands of STMT are constants, then return CONSTANT. |
6de9cd9a | 634 | |
750628d8 | 635 | Else return VARYING. */ |
6de9cd9a | 636 | |
0bca51f0 | 637 | static ccp_lattice_t |
726a989a | 638 | likely_value (gimple stmt) |
750628d8 | 639 | { |
7f879c96 | 640 | bool has_constant_operand, has_undefined_operand, all_undefined_operands; |
750628d8 DN |
641 | tree use; |
642 | ssa_op_iter iter; | |
e8114fba | 643 | unsigned i; |
6de9cd9a | 644 | |
e0c68ce9 | 645 | enum gimple_code code = gimple_code (stmt); |
726a989a RB |
646 | |
647 | /* This function appears to be called only for assignments, calls, | |
648 | conditionals, and switches, due to the logic in visit_stmt. */ | |
649 | gcc_assert (code == GIMPLE_ASSIGN | |
650 | || code == GIMPLE_CALL | |
651 | || code == GIMPLE_COND | |
652 | || code == GIMPLE_SWITCH); | |
0bca51f0 DN |
653 | |
654 | /* If the statement has volatile operands, it won't fold to a | |
655 | constant value. */ | |
726a989a | 656 | if (gimple_has_volatile_ops (stmt)) |
0bca51f0 DN |
657 | return VARYING; |
658 | ||
726a989a | 659 | /* Arrive here for more complex cases. */ |
106dec71 | 660 | has_constant_operand = false; |
7f879c96 RG |
661 | has_undefined_operand = false; |
662 | all_undefined_operands = true; | |
e8114fba | 663 | FOR_EACH_SSA_TREE_OPERAND (use, stmt, iter, SSA_OP_USE) |
750628d8 | 664 | { |
11478306 | 665 | ccp_prop_value_t *val = get_value (use); |
750628d8 | 666 | |
106dec71 | 667 | if (val->lattice_val == UNDEFINED) |
7f879c96 RG |
668 | has_undefined_operand = true; |
669 | else | |
670 | all_undefined_operands = false; | |
0bca51f0 | 671 | |
750628d8 | 672 | if (val->lattice_val == CONSTANT) |
106dec71 | 673 | has_constant_operand = true; |
6de9cd9a | 674 | } |
750628d8 | 675 | |
5006671f RG |
676 | /* There may be constants in regular rhs operands. For calls we |
677 | have to ignore lhs, fndecl and static chain, otherwise only | |
678 | the lhs. */ | |
679 | for (i = (is_gimple_call (stmt) ? 2 : 0) + gimple_has_lhs (stmt); | |
e8114fba RG |
680 | i < gimple_num_ops (stmt); ++i) |
681 | { | |
682 | tree op = gimple_op (stmt, i); | |
683 | if (!op || TREE_CODE (op) == SSA_NAME) | |
684 | continue; | |
685 | if (is_gimple_min_invariant (op)) | |
686 | has_constant_operand = true; | |
687 | } | |
688 | ||
1cdaa211 RG |
689 | if (has_constant_operand) |
690 | all_undefined_operands = false; | |
691 | ||
74bf76ed JJ |
692 | if (has_undefined_operand |
693 | && code == GIMPLE_CALL | |
694 | && gimple_call_internal_p (stmt)) | |
695 | switch (gimple_call_internal_fn (stmt)) | |
696 | { | |
697 | /* These 3 builtins use the first argument just as a magic | |
698 | way how to find out a decl uid. */ | |
699 | case IFN_GOMP_SIMD_LANE: | |
700 | case IFN_GOMP_SIMD_VF: | |
701 | case IFN_GOMP_SIMD_LAST_LANE: | |
702 | has_undefined_operand = false; | |
703 | break; | |
704 | default: | |
705 | break; | |
706 | } | |
707 | ||
7f879c96 RG |
708 | /* If the operation combines operands like COMPLEX_EXPR make sure to |
709 | not mark the result UNDEFINED if only one part of the result is | |
710 | undefined. */ | |
726a989a | 711 | if (has_undefined_operand && all_undefined_operands) |
7f879c96 | 712 | return UNDEFINED; |
726a989a | 713 | else if (code == GIMPLE_ASSIGN && has_undefined_operand) |
7f879c96 | 714 | { |
726a989a | 715 | switch (gimple_assign_rhs_code (stmt)) |
7f879c96 RG |
716 | { |
717 | /* Unary operators are handled with all_undefined_operands. */ | |
718 | case PLUS_EXPR: | |
719 | case MINUS_EXPR: | |
7f879c96 | 720 | case POINTER_PLUS_EXPR: |
7f879c96 RG |
721 | /* Not MIN_EXPR, MAX_EXPR. One VARYING operand may be selected. |
722 | Not bitwise operators, one VARYING operand may specify the | |
723 | result completely. Not logical operators for the same reason. | |
0cedb9e9 RG |
724 | Not COMPLEX_EXPR as one VARYING operand makes the result partly |
725 | not UNDEFINED. Not *DIV_EXPR, comparisons and shifts because | |
726 | the undefined operand may be promoted. */ | |
7f879c96 RG |
727 | return UNDEFINED; |
728 | ||
95cbf851 RG |
729 | case ADDR_EXPR: |
730 | /* If any part of an address is UNDEFINED, like the index | |
731 | of an ARRAY_EXPR, then treat the result as UNDEFINED. */ | |
732 | return UNDEFINED; | |
733 | ||
7f879c96 RG |
734 | default: |
735 | ; | |
736 | } | |
737 | } | |
738 | /* If there was an UNDEFINED operand but the result may be not UNDEFINED | |
6ad024b4 RG |
739 | fall back to CONSTANT. During iteration UNDEFINED may still drop |
740 | to CONSTANT. */ | |
7f879c96 | 741 | if (has_undefined_operand) |
6ad024b4 | 742 | return CONSTANT; |
7f879c96 | 743 | |
e8114fba RG |
744 | /* We do not consider virtual operands here -- load from read-only |
745 | memory may have only VARYING virtual operands, but still be | |
746 | constant. */ | |
106dec71 | 747 | if (has_constant_operand |
e8114fba | 748 | || gimple_references_memory_p (stmt)) |
0bca51f0 DN |
749 | return CONSTANT; |
750 | ||
106dec71 | 751 | return VARYING; |
6de9cd9a DN |
752 | } |
753 | ||
106dec71 ZD |
754 | /* Returns true if STMT cannot be constant. */ |
755 | ||
756 | static bool | |
726a989a | 757 | surely_varying_stmt_p (gimple stmt) |
106dec71 ZD |
758 | { |
759 | /* If the statement has operands that we cannot handle, it cannot be | |
760 | constant. */ | |
726a989a | 761 | if (gimple_has_volatile_ops (stmt)) |
106dec71 ZD |
762 | return true; |
763 | ||
174ef36d | 764 | /* If it is a call and does not return a value or is not a |
8fcbce72 JJ |
765 | builtin and not an indirect call or a call to function with |
766 | assume_aligned/alloc_align attribute, it is varying. */ | |
726a989a | 767 | if (is_gimple_call (stmt)) |
174ef36d | 768 | { |
8fcbce72 | 769 | tree fndecl, fntype = gimple_call_fntype (stmt); |
174ef36d RG |
770 | if (!gimple_call_lhs (stmt) |
771 | || ((fndecl = gimple_call_fndecl (stmt)) != NULL_TREE | |
8fcbce72 JJ |
772 | && !DECL_BUILT_IN (fndecl) |
773 | && !lookup_attribute ("assume_aligned", | |
774 | TYPE_ATTRIBUTES (fntype)) | |
775 | && !lookup_attribute ("alloc_align", | |
776 | TYPE_ATTRIBUTES (fntype)))) | |
174ef36d RG |
777 | return true; |
778 | } | |
106dec71 | 779 | |
e8114fba | 780 | /* Any other store operation is not interesting. */ |
5006671f | 781 | else if (gimple_vdef (stmt)) |
e8114fba RG |
782 | return true; |
783 | ||
106dec71 ZD |
784 | /* Anything other than assignments and conditional jumps are not |
785 | interesting for CCP. */ | |
726a989a | 786 | if (gimple_code (stmt) != GIMPLE_ASSIGN |
174ef36d RG |
787 | && gimple_code (stmt) != GIMPLE_COND |
788 | && gimple_code (stmt) != GIMPLE_SWITCH | |
789 | && gimple_code (stmt) != GIMPLE_CALL) | |
106dec71 ZD |
790 | return true; |
791 | ||
792 | return false; | |
793 | } | |
6de9cd9a | 794 | |
750628d8 | 795 | /* Initialize local data structures for CCP. */ |
6de9cd9a DN |
796 | |
797 | static void | |
750628d8 | 798 | ccp_initialize (void) |
6de9cd9a | 799 | { |
750628d8 | 800 | basic_block bb; |
6de9cd9a | 801 | |
e91c8ed6 | 802 | n_const_val = num_ssa_names; |
11478306 | 803 | const_val = XCNEWVEC (ccp_prop_value_t, n_const_val); |
6de9cd9a | 804 | |
750628d8 | 805 | /* Initialize simulation flags for PHI nodes and statements. */ |
11cd3bed | 806 | FOR_EACH_BB_FN (bb, cfun) |
6de9cd9a | 807 | { |
726a989a | 808 | gimple_stmt_iterator i; |
6de9cd9a | 809 | |
726a989a | 810 | for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i)) |
750628d8 | 811 | { |
726a989a | 812 | gimple stmt = gsi_stmt (i); |
cd6ea7a2 RH |
813 | bool is_varying; |
814 | ||
815 | /* If the statement is a control insn, then we do not | |
816 | want to avoid simulating the statement once. Failure | |
817 | to do so means that those edges will never get added. */ | |
818 | if (stmt_ends_bb_p (stmt)) | |
819 | is_varying = false; | |
820 | else | |
821 | is_varying = surely_varying_stmt_p (stmt); | |
6de9cd9a | 822 | |
106dec71 | 823 | if (is_varying) |
750628d8 | 824 | { |
0bca51f0 DN |
825 | tree def; |
826 | ssa_op_iter iter; | |
827 | ||
828 | /* If the statement will not produce a constant, mark | |
829 | all its outputs VARYING. */ | |
830 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS) | |
e8114fba | 831 | set_value_varying (def); |
750628d8 | 832 | } |
726a989a | 833 | prop_set_simulate_again (stmt, !is_varying); |
750628d8 | 834 | } |
6de9cd9a DN |
835 | } |
836 | ||
726a989a RB |
837 | /* Now process PHI nodes. We never clear the simulate_again flag on |
838 | phi nodes, since we do not know which edges are executable yet, | |
839 | except for phi nodes for virtual operands when we do not do store ccp. */ | |
11cd3bed | 840 | FOR_EACH_BB_FN (bb, cfun) |
6de9cd9a | 841 | { |
538dd0b7 | 842 | gphi_iterator i; |
750628d8 | 843 | |
726a989a RB |
844 | for (i = gsi_start_phis (bb); !gsi_end_p (i); gsi_next (&i)) |
845 | { | |
538dd0b7 | 846 | gphi *phi = i.phi (); |
726a989a | 847 | |
ea057359 | 848 | if (virtual_operand_p (gimple_phi_result (phi))) |
726a989a | 849 | prop_set_simulate_again (phi, false); |
106dec71 | 850 | else |
726a989a | 851 | prop_set_simulate_again (phi, true); |
750628d8 | 852 | } |
6de9cd9a | 853 | } |
750628d8 | 854 | } |
6de9cd9a | 855 | |
74fe548b XDL |
856 | /* Debug count support. Reset the values of ssa names |
857 | VARYING when the total number ssa names analyzed is | |
858 | beyond the debug count specified. */ | |
859 | ||
860 | static void | |
861 | do_dbg_cnt (void) | |
862 | { | |
863 | unsigned i; | |
864 | for (i = 0; i < num_ssa_names; i++) | |
865 | { | |
866 | if (!dbg_cnt (ccp)) | |
867 | { | |
868 | const_val[i].lattice_val = VARYING; | |
807e902e | 869 | const_val[i].mask = -1; |
74fe548b XDL |
870 | const_val[i].value = NULL_TREE; |
871 | } | |
872 | } | |
873 | } | |
874 | ||
6de9cd9a | 875 | |
0bca51f0 | 876 | /* Do final substitution of propagated values, cleanup the flowgraph and |
b8698a0f | 877 | free allocated storage. |
6de9cd9a | 878 | |
3253eafb JH |
879 | Return TRUE when something was optimized. */ |
880 | ||
881 | static bool | |
0bca51f0 | 882 | ccp_finalize (void) |
6de9cd9a | 883 | { |
74fe548b | 884 | bool something_changed; |
1be38ccb | 885 | unsigned i; |
74fe548b XDL |
886 | |
887 | do_dbg_cnt (); | |
1be38ccb RG |
888 | |
889 | /* Derive alignment and misalignment information from partially | |
c853f62a JJ |
890 | constant pointers in the lattice or nonzero bits from partially |
891 | constant integers. */ | |
1be38ccb RG |
892 | for (i = 1; i < num_ssa_names; ++i) |
893 | { | |
894 | tree name = ssa_name (i); | |
11478306 | 895 | ccp_prop_value_t *val; |
1be38ccb RG |
896 | unsigned int tem, align; |
897 | ||
898 | if (!name | |
c853f62a JJ |
899 | || (!POINTER_TYPE_P (TREE_TYPE (name)) |
900 | && (!INTEGRAL_TYPE_P (TREE_TYPE (name)) | |
901 | /* Don't record nonzero bits before IPA to avoid | |
902 | using too much memory. */ | |
903 | || first_pass_instance))) | |
1be38ccb RG |
904 | continue; |
905 | ||
906 | val = get_value (name); | |
907 | if (val->lattice_val != CONSTANT | |
908 | || TREE_CODE (val->value) != INTEGER_CST) | |
909 | continue; | |
910 | ||
c853f62a JJ |
911 | if (POINTER_TYPE_P (TREE_TYPE (name))) |
912 | { | |
913 | /* Trailing mask bits specify the alignment, trailing value | |
914 | bits the misalignment. */ | |
807e902e | 915 | tem = val->mask.to_uhwi (); |
c853f62a JJ |
916 | align = (tem & -tem); |
917 | if (align > 1) | |
918 | set_ptr_info_alignment (get_ptr_info (name), align, | |
919 | (TREE_INT_CST_LOW (val->value) | |
920 | & (align - 1))); | |
921 | } | |
922 | else | |
923 | { | |
807e902e KZ |
924 | unsigned int precision = TYPE_PRECISION (TREE_TYPE (val->value)); |
925 | wide_int nonzero_bits = wide_int::from (val->mask, precision, | |
926 | UNSIGNED) | val->value; | |
c853f62a JJ |
927 | nonzero_bits &= get_nonzero_bits (name); |
928 | set_nonzero_bits (name, nonzero_bits); | |
929 | } | |
1be38ccb RG |
930 | } |
931 | ||
0bca51f0 | 932 | /* Perform substitutions based on the known constant values. */ |
455e6d5b RG |
933 | something_changed = substitute_and_fold (get_constant_value, |
934 | ccp_fold_stmt, true); | |
6de9cd9a | 935 | |
0bca51f0 | 936 | free (const_val); |
ed97ddc6 | 937 | const_val = NULL; |
3253eafb | 938 | return something_changed;; |
6de9cd9a DN |
939 | } |
940 | ||
941 | ||
0bca51f0 DN |
942 | /* Compute the meet operator between *VAL1 and *VAL2. Store the result |
943 | in VAL1. | |
944 | ||
945 | any M UNDEFINED = any | |
0bca51f0 DN |
946 | any M VARYING = VARYING |
947 | Ci M Cj = Ci if (i == j) | |
948 | Ci M Cj = VARYING if (i != j) | |
106dec71 | 949 | */ |
6de9cd9a DN |
950 | |
951 | static void | |
11478306 | 952 | ccp_lattice_meet (ccp_prop_value_t *val1, ccp_prop_value_t *val2) |
6de9cd9a | 953 | { |
0bca51f0 | 954 | if (val1->lattice_val == UNDEFINED) |
6de9cd9a | 955 | { |
0bca51f0 DN |
956 | /* UNDEFINED M any = any */ |
957 | *val1 = *val2; | |
750628d8 | 958 | } |
0bca51f0 | 959 | else if (val2->lattice_val == UNDEFINED) |
195da47b | 960 | { |
0bca51f0 DN |
961 | /* any M UNDEFINED = any |
962 | Nothing to do. VAL1 already contains the value we want. */ | |
963 | ; | |
195da47b | 964 | } |
0bca51f0 DN |
965 | else if (val1->lattice_val == VARYING |
966 | || val2->lattice_val == VARYING) | |
750628d8 | 967 | { |
0bca51f0 DN |
968 | /* any M VARYING = VARYING. */ |
969 | val1->lattice_val = VARYING; | |
807e902e | 970 | val1->mask = -1; |
0bca51f0 | 971 | val1->value = NULL_TREE; |
750628d8 | 972 | } |
0b4b14ac RG |
973 | else if (val1->lattice_val == CONSTANT |
974 | && val2->lattice_val == CONSTANT | |
975 | && TREE_CODE (val1->value) == INTEGER_CST | |
976 | && TREE_CODE (val2->value) == INTEGER_CST) | |
977 | { | |
978 | /* Ci M Cj = Ci if (i == j) | |
979 | Ci M Cj = VARYING if (i != j) | |
980 | ||
981 | For INTEGER_CSTs mask unequal bits. If no equal bits remain, | |
982 | drop to varying. */ | |
807e902e KZ |
983 | val1->mask = (val1->mask | val2->mask |
984 | | (wi::to_widest (val1->value) | |
985 | ^ wi::to_widest (val2->value))); | |
986 | if (val1->mask == -1) | |
0b4b14ac RG |
987 | { |
988 | val1->lattice_val = VARYING; | |
989 | val1->value = NULL_TREE; | |
990 | } | |
991 | } | |
0bca51f0 DN |
992 | else if (val1->lattice_val == CONSTANT |
993 | && val2->lattice_val == CONSTANT | |
dce2b2f6 | 994 | && simple_cst_equal (val1->value, val2->value) == 1) |
750628d8 | 995 | { |
0bca51f0 DN |
996 | /* Ci M Cj = Ci if (i == j) |
997 | Ci M Cj = VARYING if (i != j) | |
998 | ||
0b4b14ac RG |
999 | VAL1 already contains the value we want for equivalent values. */ |
1000 | } | |
1001 | else if (val1->lattice_val == CONSTANT | |
1002 | && val2->lattice_val == CONSTANT | |
1003 | && (TREE_CODE (val1->value) == ADDR_EXPR | |
1004 | || TREE_CODE (val2->value) == ADDR_EXPR)) | |
1005 | { | |
1006 | /* When not equal addresses are involved try meeting for | |
1007 | alignment. */ | |
11478306 | 1008 | ccp_prop_value_t tem = *val2; |
0b4b14ac RG |
1009 | if (TREE_CODE (val1->value) == ADDR_EXPR) |
1010 | *val1 = get_value_for_expr (val1->value, true); | |
1011 | if (TREE_CODE (val2->value) == ADDR_EXPR) | |
1012 | tem = get_value_for_expr (val2->value, true); | |
1013 | ccp_lattice_meet (val1, &tem); | |
750628d8 DN |
1014 | } |
1015 | else | |
1016 | { | |
0bca51f0 DN |
1017 | /* Any other combination is VARYING. */ |
1018 | val1->lattice_val = VARYING; | |
807e902e | 1019 | val1->mask = -1; |
0bca51f0 | 1020 | val1->value = NULL_TREE; |
750628d8 | 1021 | } |
6de9cd9a DN |
1022 | } |
1023 | ||
1024 | ||
750628d8 DN |
1025 | /* Loop through the PHI_NODE's parameters for BLOCK and compare their |
1026 | lattice values to determine PHI_NODE's lattice value. The value of a | |
0bca51f0 | 1027 | PHI node is determined calling ccp_lattice_meet with all the arguments |
750628d8 | 1028 | of the PHI node that are incoming via executable edges. */ |
6de9cd9a | 1029 | |
750628d8 | 1030 | static enum ssa_prop_result |
538dd0b7 | 1031 | ccp_visit_phi_node (gphi *phi) |
6de9cd9a | 1032 | { |
726a989a | 1033 | unsigned i; |
11478306 | 1034 | ccp_prop_value_t *old_val, new_val; |
6de9cd9a | 1035 | |
750628d8 | 1036 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6de9cd9a | 1037 | { |
750628d8 | 1038 | fprintf (dump_file, "\nVisiting PHI node: "); |
726a989a | 1039 | print_gimple_stmt (dump_file, phi, 0, dump_flags); |
6de9cd9a | 1040 | } |
6de9cd9a | 1041 | |
726a989a | 1042 | old_val = get_value (gimple_phi_result (phi)); |
750628d8 DN |
1043 | switch (old_val->lattice_val) |
1044 | { | |
1045 | case VARYING: | |
0bca51f0 | 1046 | return SSA_PROP_VARYING; |
6de9cd9a | 1047 | |
750628d8 DN |
1048 | case CONSTANT: |
1049 | new_val = *old_val; | |
1050 | break; | |
6de9cd9a | 1051 | |
750628d8 | 1052 | case UNDEFINED: |
750628d8 | 1053 | new_val.lattice_val = UNDEFINED; |
0bca51f0 | 1054 | new_val.value = NULL_TREE; |
750628d8 | 1055 | break; |
6de9cd9a | 1056 | |
750628d8 | 1057 | default: |
1e128c5f | 1058 | gcc_unreachable (); |
750628d8 | 1059 | } |
6de9cd9a | 1060 | |
726a989a | 1061 | for (i = 0; i < gimple_phi_num_args (phi); i++) |
750628d8 | 1062 | { |
0bca51f0 DN |
1063 | /* Compute the meet operator over all the PHI arguments flowing |
1064 | through executable edges. */ | |
726a989a | 1065 | edge e = gimple_phi_arg_edge (phi, i); |
6de9cd9a | 1066 | |
750628d8 DN |
1067 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1068 | { | |
1069 | fprintf (dump_file, | |
1070 | "\n Argument #%d (%d -> %d %sexecutable)\n", | |
1071 | i, e->src->index, e->dest->index, | |
1072 | (e->flags & EDGE_EXECUTABLE) ? "" : "not "); | |
1073 | } | |
1074 | ||
1075 | /* If the incoming edge is executable, Compute the meet operator for | |
1076 | the existing value of the PHI node and the current PHI argument. */ | |
1077 | if (e->flags & EDGE_EXECUTABLE) | |
1078 | { | |
726a989a | 1079 | tree arg = gimple_phi_arg (phi, i)->def; |
11478306 | 1080 | ccp_prop_value_t arg_val = get_value_for_expr (arg, false); |
6de9cd9a | 1081 | |
0bca51f0 | 1082 | ccp_lattice_meet (&new_val, &arg_val); |
6de9cd9a | 1083 | |
750628d8 DN |
1084 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1085 | { | |
1086 | fprintf (dump_file, "\t"); | |
0bca51f0 DN |
1087 | print_generic_expr (dump_file, arg, dump_flags); |
1088 | dump_lattice_value (dump_file, "\tValue: ", arg_val); | |
750628d8 DN |
1089 | fprintf (dump_file, "\n"); |
1090 | } | |
6de9cd9a | 1091 | |
750628d8 DN |
1092 | if (new_val.lattice_val == VARYING) |
1093 | break; | |
1094 | } | |
1095 | } | |
6de9cd9a DN |
1096 | |
1097 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
750628d8 DN |
1098 | { |
1099 | dump_lattice_value (dump_file, "\n PHI node value: ", new_val); | |
1100 | fprintf (dump_file, "\n\n"); | |
1101 | } | |
1102 | ||
106dec71 | 1103 | /* Make the transition to the new value. */ |
726a989a | 1104 | if (set_lattice_value (gimple_phi_result (phi), new_val)) |
750628d8 DN |
1105 | { |
1106 | if (new_val.lattice_val == VARYING) | |
1107 | return SSA_PROP_VARYING; | |
1108 | else | |
1109 | return SSA_PROP_INTERESTING; | |
1110 | } | |
1111 | else | |
1112 | return SSA_PROP_NOT_INTERESTING; | |
6de9cd9a DN |
1113 | } |
1114 | ||
84d77ca6 | 1115 | /* Return the constant value for OP or OP otherwise. */ |
0354c0c7 BS |
1116 | |
1117 | static tree | |
84d77ca6 | 1118 | valueize_op (tree op) |
0354c0c7 | 1119 | { |
0354c0c7 BS |
1120 | if (TREE_CODE (op) == SSA_NAME) |
1121 | { | |
84d77ca6 RG |
1122 | tree tem = get_constant_value (op); |
1123 | if (tem) | |
1124 | return tem; | |
0354c0c7 BS |
1125 | } |
1126 | return op; | |
1127 | } | |
1128 | ||
d2a85801 RB |
1129 | /* Return the constant value for OP, but signal to not follow SSA |
1130 | edges if the definition may be simulated again. */ | |
1131 | ||
1132 | static tree | |
1133 | valueize_op_1 (tree op) | |
1134 | { | |
1135 | if (TREE_CODE (op) == SSA_NAME) | |
1136 | { | |
1137 | tree tem = get_constant_value (op); | |
1138 | if (tem) | |
1139 | return tem; | |
1140 | /* If the definition may be simulated again we cannot follow | |
1141 | this SSA edge as the SSA propagator does not necessarily | |
1142 | re-visit the use. */ | |
1143 | gimple def_stmt = SSA_NAME_DEF_STMT (op); | |
1144 | if (prop_simulate_again_p (def_stmt)) | |
1145 | return NULL_TREE; | |
1146 | } | |
1147 | return op; | |
1148 | } | |
1149 | ||
750628d8 DN |
1150 | /* CCP specific front-end to the non-destructive constant folding |
1151 | routines. | |
6de9cd9a DN |
1152 | |
1153 | Attempt to simplify the RHS of STMT knowing that one or more | |
1154 | operands are constants. | |
1155 | ||
1156 | If simplification is possible, return the simplified RHS, | |
726a989a | 1157 | otherwise return the original RHS or NULL_TREE. */ |
6de9cd9a DN |
1158 | |
1159 | static tree | |
726a989a | 1160 | ccp_fold (gimple stmt) |
6de9cd9a | 1161 | { |
db3927fb | 1162 | location_t loc = gimple_location (stmt); |
726a989a | 1163 | switch (gimple_code (stmt)) |
0bca51f0 | 1164 | { |
726a989a RB |
1165 | case GIMPLE_COND: |
1166 | { | |
1167 | /* Handle comparison operators that can appear in GIMPLE form. */ | |
84d77ca6 RG |
1168 | tree op0 = valueize_op (gimple_cond_lhs (stmt)); |
1169 | tree op1 = valueize_op (gimple_cond_rhs (stmt)); | |
726a989a | 1170 | enum tree_code code = gimple_cond_code (stmt); |
db3927fb | 1171 | return fold_binary_loc (loc, code, boolean_type_node, op0, op1); |
726a989a | 1172 | } |
6de9cd9a | 1173 | |
726a989a RB |
1174 | case GIMPLE_SWITCH: |
1175 | { | |
84d77ca6 | 1176 | /* Return the constant switch index. */ |
538dd0b7 | 1177 | return valueize_op (gimple_switch_index (as_a <gswitch *> (stmt))); |
726a989a | 1178 | } |
00d382a8 | 1179 | |
cfef45c8 RG |
1180 | case GIMPLE_ASSIGN: |
1181 | case GIMPLE_CALL: | |
d2a85801 RB |
1182 | return gimple_fold_stmt_to_constant_1 (stmt, |
1183 | valueize_op, valueize_op_1); | |
87e1e42b | 1184 | |
ae3df618 | 1185 | default: |
cfef45c8 | 1186 | gcc_unreachable (); |
ae3df618 | 1187 | } |
ae3df618 | 1188 | } |
726a989a | 1189 | |
0b4b14ac RG |
1190 | /* Apply the operation CODE in type TYPE to the value, mask pair |
1191 | RVAL and RMASK representing a value of type RTYPE and set | |
1192 | the value, mask pair *VAL and *MASK to the result. */ | |
1193 | ||
1194 | static void | |
1195 | bit_value_unop_1 (enum tree_code code, tree type, | |
807e902e KZ |
1196 | widest_int *val, widest_int *mask, |
1197 | tree rtype, const widest_int &rval, const widest_int &rmask) | |
0b4b14ac RG |
1198 | { |
1199 | switch (code) | |
1200 | { | |
1201 | case BIT_NOT_EXPR: | |
1202 | *mask = rmask; | |
27bcd47c | 1203 | *val = ~rval; |
0b4b14ac RG |
1204 | break; |
1205 | ||
1206 | case NEGATE_EXPR: | |
1207 | { | |
807e902e | 1208 | widest_int temv, temm; |
0b4b14ac RG |
1209 | /* Return ~rval + 1. */ |
1210 | bit_value_unop_1 (BIT_NOT_EXPR, type, &temv, &temm, type, rval, rmask); | |
1211 | bit_value_binop_1 (PLUS_EXPR, type, val, mask, | |
807e902e | 1212 | type, temv, temm, type, 1, 0); |
0b4b14ac RG |
1213 | break; |
1214 | } | |
1215 | ||
1216 | CASE_CONVERT: | |
1217 | { | |
807e902e | 1218 | signop sgn; |
0b4b14ac RG |
1219 | |
1220 | /* First extend mask and value according to the original type. */ | |
807e902e KZ |
1221 | sgn = TYPE_SIGN (rtype); |
1222 | *mask = wi::ext (rmask, TYPE_PRECISION (rtype), sgn); | |
1223 | *val = wi::ext (rval, TYPE_PRECISION (rtype), sgn); | |
0b4b14ac RG |
1224 | |
1225 | /* Then extend mask and value according to the target type. */ | |
807e902e KZ |
1226 | sgn = TYPE_SIGN (type); |
1227 | *mask = wi::ext (*mask, TYPE_PRECISION (type), sgn); | |
1228 | *val = wi::ext (*val, TYPE_PRECISION (type), sgn); | |
0b4b14ac RG |
1229 | break; |
1230 | } | |
1231 | ||
1232 | default: | |
807e902e | 1233 | *mask = -1; |
0b4b14ac RG |
1234 | break; |
1235 | } | |
1236 | } | |
1237 | ||
1238 | /* Apply the operation CODE in type TYPE to the value, mask pairs | |
1239 | R1VAL, R1MASK and R2VAL, R2MASK representing a values of type R1TYPE | |
1240 | and R2TYPE and set the value, mask pair *VAL and *MASK to the result. */ | |
1241 | ||
1242 | static void | |
1243 | bit_value_binop_1 (enum tree_code code, tree type, | |
807e902e KZ |
1244 | widest_int *val, widest_int *mask, |
1245 | tree r1type, const widest_int &r1val, | |
1246 | const widest_int &r1mask, tree r2type, | |
1247 | const widest_int &r2val, const widest_int &r2mask) | |
0b4b14ac | 1248 | { |
807e902e KZ |
1249 | signop sgn = TYPE_SIGN (type); |
1250 | int width = TYPE_PRECISION (type); | |
1251 | bool swap_p = false; | |
1252 | ||
1253 | /* Assume we'll get a constant result. Use an initial non varying | |
1254 | value, we fall back to varying in the end if necessary. */ | |
1255 | *mask = -1; | |
1256 | ||
0b4b14ac RG |
1257 | switch (code) |
1258 | { | |
1259 | case BIT_AND_EXPR: | |
1260 | /* The mask is constant where there is a known not | |
1261 | set bit, (m1 | m2) & ((v1 | m1) & (v2 | m2)) */ | |
27bcd47c LC |
1262 | *mask = (r1mask | r2mask) & (r1val | r1mask) & (r2val | r2mask); |
1263 | *val = r1val & r2val; | |
0b4b14ac RG |
1264 | break; |
1265 | ||
1266 | case BIT_IOR_EXPR: | |
1267 | /* The mask is constant where there is a known | |
1268 | set bit, (m1 | m2) & ~((v1 & ~m1) | (v2 & ~m2)). */ | |
27bcd47c LC |
1269 | *mask = (r1mask | r2mask) |
1270 | .and_not (r1val.and_not (r1mask) | r2val.and_not (r2mask)); | |
1271 | *val = r1val | r2val; | |
0b4b14ac RG |
1272 | break; |
1273 | ||
1274 | case BIT_XOR_EXPR: | |
1275 | /* m1 | m2 */ | |
27bcd47c LC |
1276 | *mask = r1mask | r2mask; |
1277 | *val = r1val ^ r2val; | |
0b4b14ac RG |
1278 | break; |
1279 | ||
1280 | case LROTATE_EXPR: | |
1281 | case RROTATE_EXPR: | |
807e902e | 1282 | if (r2mask == 0) |
0b4b14ac | 1283 | { |
807e902e KZ |
1284 | widest_int shift = r2val; |
1285 | if (shift == 0) | |
1286 | { | |
1287 | *mask = r1mask; | |
1288 | *val = r1val; | |
1289 | } | |
1290 | else | |
1291 | { | |
1292 | if (wi::neg_p (shift)) | |
1293 | { | |
1294 | shift = -shift; | |
1295 | if (code == RROTATE_EXPR) | |
1296 | code = LROTATE_EXPR; | |
1297 | else | |
1298 | code = RROTATE_EXPR; | |
1299 | } | |
1300 | if (code == RROTATE_EXPR) | |
1301 | { | |
1302 | *mask = wi::rrotate (r1mask, shift, width); | |
1303 | *val = wi::rrotate (r1val, shift, width); | |
1304 | } | |
1305 | else | |
1306 | { | |
1307 | *mask = wi::lrotate (r1mask, shift, width); | |
1308 | *val = wi::lrotate (r1val, shift, width); | |
1309 | } | |
1310 | } | |
0b4b14ac RG |
1311 | } |
1312 | break; | |
1313 | ||
1314 | case LSHIFT_EXPR: | |
1315 | case RSHIFT_EXPR: | |
1316 | /* ??? We can handle partially known shift counts if we know | |
1317 | its sign. That way we can tell that (x << (y | 8)) & 255 | |
1318 | is zero. */ | |
807e902e | 1319 | if (r2mask == 0) |
0b4b14ac | 1320 | { |
807e902e KZ |
1321 | widest_int shift = r2val; |
1322 | if (shift == 0) | |
0b4b14ac | 1323 | { |
807e902e KZ |
1324 | *mask = r1mask; |
1325 | *val = r1val; | |
0b4b14ac RG |
1326 | } |
1327 | else | |
1328 | { | |
807e902e KZ |
1329 | if (wi::neg_p (shift)) |
1330 | { | |
1331 | shift = -shift; | |
1332 | if (code == RSHIFT_EXPR) | |
1333 | code = LSHIFT_EXPR; | |
1334 | else | |
1335 | code = RSHIFT_EXPR; | |
1336 | } | |
1337 | if (code == RSHIFT_EXPR) | |
1338 | { | |
1339 | *mask = wi::rshift (wi::ext (r1mask, width, sgn), shift, sgn); | |
1340 | *val = wi::rshift (wi::ext (r1val, width, sgn), shift, sgn); | |
1341 | } | |
1342 | else | |
1343 | { | |
1344 | *mask = wi::ext (wi::lshift (r1mask, shift), width, sgn); | |
1345 | *val = wi::ext (wi::lshift (r1val, shift), width, sgn); | |
1346 | } | |
0b4b14ac RG |
1347 | } |
1348 | } | |
1349 | break; | |
1350 | ||
1351 | case PLUS_EXPR: | |
1352 | case POINTER_PLUS_EXPR: | |
1353 | { | |
0b4b14ac RG |
1354 | /* Do the addition with unknown bits set to zero, to give carry-ins of |
1355 | zero wherever possible. */ | |
807e902e KZ |
1356 | widest_int lo = r1val.and_not (r1mask) + r2val.and_not (r2mask); |
1357 | lo = wi::ext (lo, width, sgn); | |
0b4b14ac RG |
1358 | /* Do the addition with unknown bits set to one, to give carry-ins of |
1359 | one wherever possible. */ | |
807e902e KZ |
1360 | widest_int hi = (r1val | r1mask) + (r2val | r2mask); |
1361 | hi = wi::ext (hi, width, sgn); | |
0b4b14ac RG |
1362 | /* Each bit in the result is known if (a) the corresponding bits in |
1363 | both inputs are known, and (b) the carry-in to that bit position | |
1364 | is known. We can check condition (b) by seeing if we got the same | |
1365 | result with minimised carries as with maximised carries. */ | |
27bcd47c | 1366 | *mask = r1mask | r2mask | (lo ^ hi); |
807e902e | 1367 | *mask = wi::ext (*mask, width, sgn); |
0b4b14ac RG |
1368 | /* It shouldn't matter whether we choose lo or hi here. */ |
1369 | *val = lo; | |
1370 | break; | |
1371 | } | |
1372 | ||
1373 | case MINUS_EXPR: | |
1374 | { | |
807e902e | 1375 | widest_int temv, temm; |
0b4b14ac RG |
1376 | bit_value_unop_1 (NEGATE_EXPR, r2type, &temv, &temm, |
1377 | r2type, r2val, r2mask); | |
1378 | bit_value_binop_1 (PLUS_EXPR, type, val, mask, | |
1379 | r1type, r1val, r1mask, | |
1380 | r2type, temv, temm); | |
1381 | break; | |
1382 | } | |
1383 | ||
1384 | case MULT_EXPR: | |
1385 | { | |
1386 | /* Just track trailing zeros in both operands and transfer | |
1387 | them to the other. */ | |
807e902e KZ |
1388 | int r1tz = wi::ctz (r1val | r1mask); |
1389 | int r2tz = wi::ctz (r2val | r2mask); | |
1390 | if (r1tz + r2tz >= width) | |
0b4b14ac | 1391 | { |
807e902e KZ |
1392 | *mask = 0; |
1393 | *val = 0; | |
0b4b14ac RG |
1394 | } |
1395 | else if (r1tz + r2tz > 0) | |
1396 | { | |
807e902e KZ |
1397 | *mask = wi::ext (wi::mask <widest_int> (r1tz + r2tz, true), |
1398 | width, sgn); | |
1399 | *val = 0; | |
0b4b14ac RG |
1400 | } |
1401 | break; | |
1402 | } | |
1403 | ||
1404 | case EQ_EXPR: | |
1405 | case NE_EXPR: | |
1406 | { | |
807e902e | 1407 | widest_int m = r1mask | r2mask; |
27bcd47c | 1408 | if (r1val.and_not (m) != r2val.and_not (m)) |
0b4b14ac | 1409 | { |
807e902e KZ |
1410 | *mask = 0; |
1411 | *val = ((code == EQ_EXPR) ? 0 : 1); | |
0b4b14ac RG |
1412 | } |
1413 | else | |
1414 | { | |
1415 | /* We know the result of a comparison is always one or zero. */ | |
807e902e KZ |
1416 | *mask = 1; |
1417 | *val = 0; | |
0b4b14ac RG |
1418 | } |
1419 | break; | |
1420 | } | |
1421 | ||
1422 | case GE_EXPR: | |
1423 | case GT_EXPR: | |
807e902e KZ |
1424 | swap_p = true; |
1425 | code = swap_tree_comparison (code); | |
1426 | /* Fall through. */ | |
0b4b14ac RG |
1427 | case LT_EXPR: |
1428 | case LE_EXPR: | |
1429 | { | |
1430 | int minmax, maxmin; | |
807e902e KZ |
1431 | |
1432 | const widest_int &o1val = swap_p ? r2val : r1val; | |
1433 | const widest_int &o1mask = swap_p ? r2mask : r1mask; | |
1434 | const widest_int &o2val = swap_p ? r1val : r2val; | |
1435 | const widest_int &o2mask = swap_p ? r1mask : r2mask; | |
1436 | ||
0b4b14ac | 1437 | /* If the most significant bits are not known we know nothing. */ |
807e902e | 1438 | if (wi::neg_p (o1mask) || wi::neg_p (o2mask)) |
0b4b14ac RG |
1439 | break; |
1440 | ||
0425d6f5 | 1441 | /* For comparisons the signedness is in the comparison operands. */ |
807e902e | 1442 | sgn = TYPE_SIGN (r1type); |
0425d6f5 | 1443 | |
0b4b14ac RG |
1444 | /* If we know the most significant bits we know the values |
1445 | value ranges by means of treating varying bits as zero | |
1446 | or one. Do a cross comparison of the max/min pairs. */ | |
807e902e KZ |
1447 | maxmin = wi::cmp (o1val | o1mask, o2val.and_not (o2mask), sgn); |
1448 | minmax = wi::cmp (o1val.and_not (o1mask), o2val | o2mask, sgn); | |
1449 | if (maxmin < 0) /* o1 is less than o2. */ | |
0b4b14ac | 1450 | { |
807e902e KZ |
1451 | *mask = 0; |
1452 | *val = 1; | |
0b4b14ac | 1453 | } |
807e902e | 1454 | else if (minmax > 0) /* o1 is not less or equal to o2. */ |
0b4b14ac | 1455 | { |
807e902e KZ |
1456 | *mask = 0; |
1457 | *val = 0; | |
0b4b14ac | 1458 | } |
807e902e | 1459 | else if (maxmin == minmax) /* o1 and o2 are equal. */ |
0b4b14ac RG |
1460 | { |
1461 | /* This probably should never happen as we'd have | |
1462 | folded the thing during fully constant value folding. */ | |
807e902e KZ |
1463 | *mask = 0; |
1464 | *val = (code == LE_EXPR ? 1 : 0); | |
0b4b14ac RG |
1465 | } |
1466 | else | |
1467 | { | |
1468 | /* We know the result of a comparison is always one or zero. */ | |
807e902e KZ |
1469 | *mask = 1; |
1470 | *val = 0; | |
0b4b14ac RG |
1471 | } |
1472 | break; | |
1473 | } | |
1474 | ||
1475 | default:; | |
1476 | } | |
1477 | } | |
1478 | ||
1479 | /* Return the propagation value when applying the operation CODE to | |
1480 | the value RHS yielding type TYPE. */ | |
1481 | ||
11478306 | 1482 | static ccp_prop_value_t |
0b4b14ac RG |
1483 | bit_value_unop (enum tree_code code, tree type, tree rhs) |
1484 | { | |
11478306 | 1485 | ccp_prop_value_t rval = get_value_for_expr (rhs, true); |
807e902e | 1486 | widest_int value, mask; |
11478306 | 1487 | ccp_prop_value_t val; |
6ad024b4 RG |
1488 | |
1489 | if (rval.lattice_val == UNDEFINED) | |
1490 | return rval; | |
1491 | ||
0b4b14ac RG |
1492 | gcc_assert ((rval.lattice_val == CONSTANT |
1493 | && TREE_CODE (rval.value) == INTEGER_CST) | |
807e902e | 1494 | || rval.mask == -1); |
0b4b14ac | 1495 | bit_value_unop_1 (code, type, &value, &mask, |
807e902e KZ |
1496 | TREE_TYPE (rhs), value_to_wide_int (rval), rval.mask); |
1497 | if (mask != -1) | |
0b4b14ac RG |
1498 | { |
1499 | val.lattice_val = CONSTANT; | |
1500 | val.mask = mask; | |
1501 | /* ??? Delay building trees here. */ | |
807e902e | 1502 | val.value = wide_int_to_tree (type, value); |
0b4b14ac RG |
1503 | } |
1504 | else | |
1505 | { | |
1506 | val.lattice_val = VARYING; | |
1507 | val.value = NULL_TREE; | |
807e902e | 1508 | val.mask = -1; |
0b4b14ac RG |
1509 | } |
1510 | return val; | |
1511 | } | |
1512 | ||
1513 | /* Return the propagation value when applying the operation CODE to | |
1514 | the values RHS1 and RHS2 yielding type TYPE. */ | |
1515 | ||
11478306 | 1516 | static ccp_prop_value_t |
0b4b14ac RG |
1517 | bit_value_binop (enum tree_code code, tree type, tree rhs1, tree rhs2) |
1518 | { | |
11478306 JH |
1519 | ccp_prop_value_t r1val = get_value_for_expr (rhs1, true); |
1520 | ccp_prop_value_t r2val = get_value_for_expr (rhs2, true); | |
807e902e | 1521 | widest_int value, mask; |
11478306 | 1522 | ccp_prop_value_t val; |
6ad024b4 RG |
1523 | |
1524 | if (r1val.lattice_val == UNDEFINED | |
1525 | || r2val.lattice_val == UNDEFINED) | |
1526 | { | |
1527 | val.lattice_val = VARYING; | |
1528 | val.value = NULL_TREE; | |
807e902e | 1529 | val.mask = -1; |
6ad024b4 RG |
1530 | return val; |
1531 | } | |
1532 | ||
0b4b14ac RG |
1533 | gcc_assert ((r1val.lattice_val == CONSTANT |
1534 | && TREE_CODE (r1val.value) == INTEGER_CST) | |
807e902e | 1535 | || r1val.mask == -1); |
0b4b14ac RG |
1536 | gcc_assert ((r2val.lattice_val == CONSTANT |
1537 | && TREE_CODE (r2val.value) == INTEGER_CST) | |
807e902e | 1538 | || r2val.mask == -1); |
0b4b14ac | 1539 | bit_value_binop_1 (code, type, &value, &mask, |
807e902e KZ |
1540 | TREE_TYPE (rhs1), value_to_wide_int (r1val), r1val.mask, |
1541 | TREE_TYPE (rhs2), value_to_wide_int (r2val), r2val.mask); | |
1542 | if (mask != -1) | |
0b4b14ac RG |
1543 | { |
1544 | val.lattice_val = CONSTANT; | |
1545 | val.mask = mask; | |
1546 | /* ??? Delay building trees here. */ | |
807e902e | 1547 | val.value = wide_int_to_tree (type, value); |
0b4b14ac RG |
1548 | } |
1549 | else | |
1550 | { | |
1551 | val.lattice_val = VARYING; | |
1552 | val.value = NULL_TREE; | |
807e902e | 1553 | val.mask = -1; |
0b4b14ac RG |
1554 | } |
1555 | return val; | |
1556 | } | |
1557 | ||
8fcbce72 JJ |
1558 | /* Return the propagation value for __builtin_assume_aligned |
1559 | and functions with assume_aligned or alloc_aligned attribute. | |
1560 | For __builtin_assume_aligned, ATTR is NULL_TREE, | |
1561 | for assume_aligned attribute ATTR is non-NULL and ALLOC_ALIGNED | |
1562 | is false, for alloc_aligned attribute ATTR is non-NULL and | |
1563 | ALLOC_ALIGNED is true. */ | |
45d439ac | 1564 | |
11478306 JH |
1565 | static ccp_prop_value_t |
1566 | bit_value_assume_aligned (gimple stmt, tree attr, ccp_prop_value_t ptrval, | |
8fcbce72 | 1567 | bool alloc_aligned) |
45d439ac | 1568 | { |
8fcbce72 | 1569 | tree align, misalign = NULL_TREE, type; |
45d439ac | 1570 | unsigned HOST_WIDE_INT aligni, misaligni = 0; |
11478306 | 1571 | ccp_prop_value_t alignval; |
807e902e | 1572 | widest_int value, mask; |
11478306 | 1573 | ccp_prop_value_t val; |
8fcbce72 JJ |
1574 | |
1575 | if (attr == NULL_TREE) | |
1576 | { | |
1577 | tree ptr = gimple_call_arg (stmt, 0); | |
1578 | type = TREE_TYPE (ptr); | |
1579 | ptrval = get_value_for_expr (ptr, true); | |
1580 | } | |
1581 | else | |
1582 | { | |
1583 | tree lhs = gimple_call_lhs (stmt); | |
1584 | type = TREE_TYPE (lhs); | |
1585 | } | |
1586 | ||
45d439ac JJ |
1587 | if (ptrval.lattice_val == UNDEFINED) |
1588 | return ptrval; | |
1589 | gcc_assert ((ptrval.lattice_val == CONSTANT | |
1590 | && TREE_CODE (ptrval.value) == INTEGER_CST) | |
807e902e | 1591 | || ptrval.mask == -1); |
8fcbce72 | 1592 | if (attr == NULL_TREE) |
45d439ac | 1593 | { |
8fcbce72 JJ |
1594 | /* Get aligni and misaligni from __builtin_assume_aligned. */ |
1595 | align = gimple_call_arg (stmt, 1); | |
1596 | if (!tree_fits_uhwi_p (align)) | |
45d439ac | 1597 | return ptrval; |
8fcbce72 JJ |
1598 | aligni = tree_to_uhwi (align); |
1599 | if (gimple_call_num_args (stmt) > 2) | |
1600 | { | |
1601 | misalign = gimple_call_arg (stmt, 2); | |
1602 | if (!tree_fits_uhwi_p (misalign)) | |
1603 | return ptrval; | |
1604 | misaligni = tree_to_uhwi (misalign); | |
1605 | } | |
1606 | } | |
1607 | else | |
1608 | { | |
1609 | /* Get aligni and misaligni from assume_aligned or | |
1610 | alloc_align attributes. */ | |
1611 | if (TREE_VALUE (attr) == NULL_TREE) | |
1612 | return ptrval; | |
1613 | attr = TREE_VALUE (attr); | |
1614 | align = TREE_VALUE (attr); | |
1615 | if (!tree_fits_uhwi_p (align)) | |
45d439ac | 1616 | return ptrval; |
8fcbce72 JJ |
1617 | aligni = tree_to_uhwi (align); |
1618 | if (alloc_aligned) | |
1619 | { | |
1620 | if (aligni == 0 || aligni > gimple_call_num_args (stmt)) | |
1621 | return ptrval; | |
1622 | align = gimple_call_arg (stmt, aligni - 1); | |
1623 | if (!tree_fits_uhwi_p (align)) | |
1624 | return ptrval; | |
1625 | aligni = tree_to_uhwi (align); | |
1626 | } | |
1627 | else if (TREE_CHAIN (attr) && TREE_VALUE (TREE_CHAIN (attr))) | |
1628 | { | |
1629 | misalign = TREE_VALUE (TREE_CHAIN (attr)); | |
1630 | if (!tree_fits_uhwi_p (misalign)) | |
1631 | return ptrval; | |
1632 | misaligni = tree_to_uhwi (misalign); | |
1633 | } | |
45d439ac | 1634 | } |
8fcbce72 JJ |
1635 | if (aligni <= 1 || (aligni & (aligni - 1)) != 0 || misaligni >= aligni) |
1636 | return ptrval; | |
1637 | ||
45d439ac JJ |
1638 | align = build_int_cst_type (type, -aligni); |
1639 | alignval = get_value_for_expr (align, true); | |
1640 | bit_value_binop_1 (BIT_AND_EXPR, type, &value, &mask, | |
807e902e KZ |
1641 | type, value_to_wide_int (ptrval), ptrval.mask, |
1642 | type, value_to_wide_int (alignval), alignval.mask); | |
1643 | if (mask != -1) | |
45d439ac JJ |
1644 | { |
1645 | val.lattice_val = CONSTANT; | |
1646 | val.mask = mask; | |
807e902e KZ |
1647 | gcc_assert ((mask.to_uhwi () & (aligni - 1)) == 0); |
1648 | gcc_assert ((value.to_uhwi () & (aligni - 1)) == 0); | |
1649 | value |= misaligni; | |
45d439ac | 1650 | /* ??? Delay building trees here. */ |
807e902e | 1651 | val.value = wide_int_to_tree (type, value); |
45d439ac JJ |
1652 | } |
1653 | else | |
1654 | { | |
1655 | val.lattice_val = VARYING; | |
1656 | val.value = NULL_TREE; | |
807e902e | 1657 | val.mask = -1; |
45d439ac JJ |
1658 | } |
1659 | return val; | |
1660 | } | |
1661 | ||
726a989a RB |
1662 | /* Evaluate statement STMT. |
1663 | Valid only for assignments, calls, conditionals, and switches. */ | |
6de9cd9a | 1664 | |
11478306 | 1665 | static ccp_prop_value_t |
726a989a | 1666 | evaluate_stmt (gimple stmt) |
6de9cd9a | 1667 | { |
11478306 | 1668 | ccp_prop_value_t val; |
faaf1436 | 1669 | tree simplified = NULL_TREE; |
0bca51f0 | 1670 | ccp_lattice_t likelyvalue = likely_value (stmt); |
0b4b14ac | 1671 | bool is_constant = false; |
13e49da9 | 1672 | unsigned int align; |
0bca51f0 | 1673 | |
0b4b14ac RG |
1674 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1675 | { | |
1676 | fprintf (dump_file, "which is likely "); | |
1677 | switch (likelyvalue) | |
1678 | { | |
1679 | case CONSTANT: | |
1680 | fprintf (dump_file, "CONSTANT"); | |
1681 | break; | |
1682 | case UNDEFINED: | |
1683 | fprintf (dump_file, "UNDEFINED"); | |
1684 | break; | |
1685 | case VARYING: | |
1686 | fprintf (dump_file, "VARYING"); | |
1687 | break; | |
1688 | default:; | |
1689 | } | |
1690 | fprintf (dump_file, "\n"); | |
1691 | } | |
6ac01510 | 1692 | |
6de9cd9a DN |
1693 | /* If the statement is likely to have a CONSTANT result, then try |
1694 | to fold the statement to determine the constant value. */ | |
726a989a RB |
1695 | /* FIXME. This is the only place that we call ccp_fold. |
1696 | Since likely_value never returns CONSTANT for calls, we will | |
1697 | not attempt to fold them, including builtins that may profit. */ | |
6de9cd9a | 1698 | if (likelyvalue == CONSTANT) |
0b4b14ac RG |
1699 | { |
1700 | fold_defer_overflow_warnings (); | |
1701 | simplified = ccp_fold (stmt); | |
1702 | is_constant = simplified && is_gimple_min_invariant (simplified); | |
1703 | fold_undefer_overflow_warnings (is_constant, stmt, 0); | |
1704 | if (is_constant) | |
1705 | { | |
1706 | /* The statement produced a constant value. */ | |
1707 | val.lattice_val = CONSTANT; | |
1708 | val.value = simplified; | |
807e902e | 1709 | val.mask = 0; |
0b4b14ac RG |
1710 | } |
1711 | } | |
6de9cd9a DN |
1712 | /* If the statement is likely to have a VARYING result, then do not |
1713 | bother folding the statement. */ | |
87e1e42b | 1714 | else if (likelyvalue == VARYING) |
726a989a | 1715 | { |
e0c68ce9 | 1716 | enum gimple_code code = gimple_code (stmt); |
726a989a RB |
1717 | if (code == GIMPLE_ASSIGN) |
1718 | { | |
1719 | enum tree_code subcode = gimple_assign_rhs_code (stmt); | |
b8698a0f | 1720 | |
726a989a RB |
1721 | /* Other cases cannot satisfy is_gimple_min_invariant |
1722 | without folding. */ | |
1723 | if (get_gimple_rhs_class (subcode) == GIMPLE_SINGLE_RHS) | |
1724 | simplified = gimple_assign_rhs1 (stmt); | |
1725 | } | |
1726 | else if (code == GIMPLE_SWITCH) | |
538dd0b7 | 1727 | simplified = gimple_switch_index (as_a <gswitch *> (stmt)); |
726a989a | 1728 | else |
44e10129 MM |
1729 | /* These cannot satisfy is_gimple_min_invariant without folding. */ |
1730 | gcc_assert (code == GIMPLE_CALL || code == GIMPLE_COND); | |
0b4b14ac RG |
1731 | is_constant = simplified && is_gimple_min_invariant (simplified); |
1732 | if (is_constant) | |
1733 | { | |
1734 | /* The statement produced a constant value. */ | |
1735 | val.lattice_val = CONSTANT; | |
1736 | val.value = simplified; | |
807e902e | 1737 | val.mask = 0; |
0b4b14ac | 1738 | } |
726a989a | 1739 | } |
6de9cd9a | 1740 | |
0b4b14ac RG |
1741 | /* Resort to simplification for bitwise tracking. */ |
1742 | if (flag_tree_bit_ccp | |
36dc1a88 | 1743 | && (likelyvalue == CONSTANT || is_gimple_call (stmt)) |
0b4b14ac | 1744 | && !is_constant) |
00d382a8 | 1745 | { |
0b4b14ac RG |
1746 | enum gimple_code code = gimple_code (stmt); |
1747 | val.lattice_val = VARYING; | |
1748 | val.value = NULL_TREE; | |
807e902e | 1749 | val.mask = -1; |
0b4b14ac | 1750 | if (code == GIMPLE_ASSIGN) |
00d382a8 | 1751 | { |
0b4b14ac RG |
1752 | enum tree_code subcode = gimple_assign_rhs_code (stmt); |
1753 | tree rhs1 = gimple_assign_rhs1 (stmt); | |
1754 | switch (get_gimple_rhs_class (subcode)) | |
1755 | { | |
1756 | case GIMPLE_SINGLE_RHS: | |
1757 | if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
1758 | || POINTER_TYPE_P (TREE_TYPE (rhs1))) | |
1759 | val = get_value_for_expr (rhs1, true); | |
1760 | break; | |
1761 | ||
1762 | case GIMPLE_UNARY_RHS: | |
1763 | if ((INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
1764 | || POINTER_TYPE_P (TREE_TYPE (rhs1))) | |
1765 | && (INTEGRAL_TYPE_P (gimple_expr_type (stmt)) | |
1766 | || POINTER_TYPE_P (gimple_expr_type (stmt)))) | |
1767 | val = bit_value_unop (subcode, gimple_expr_type (stmt), rhs1); | |
1768 | break; | |
1769 | ||
1770 | case GIMPLE_BINARY_RHS: | |
1771 | if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
1772 | || POINTER_TYPE_P (TREE_TYPE (rhs1))) | |
1773 | { | |
4e996296 | 1774 | tree lhs = gimple_assign_lhs (stmt); |
0b4b14ac RG |
1775 | tree rhs2 = gimple_assign_rhs2 (stmt); |
1776 | val = bit_value_binop (subcode, | |
4e996296 | 1777 | TREE_TYPE (lhs), rhs1, rhs2); |
0b4b14ac RG |
1778 | } |
1779 | break; | |
1780 | ||
1781 | default:; | |
1782 | } | |
00d382a8 | 1783 | } |
0b4b14ac RG |
1784 | else if (code == GIMPLE_COND) |
1785 | { | |
1786 | enum tree_code code = gimple_cond_code (stmt); | |
1787 | tree rhs1 = gimple_cond_lhs (stmt); | |
1788 | tree rhs2 = gimple_cond_rhs (stmt); | |
1789 | if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
1790 | || POINTER_TYPE_P (TREE_TYPE (rhs1))) | |
1791 | val = bit_value_binop (code, TREE_TYPE (rhs1), rhs1, rhs2); | |
1792 | } | |
3138f224 | 1793 | else if (gimple_call_builtin_p (stmt, BUILT_IN_NORMAL)) |
1be38ccb | 1794 | { |
3138f224 | 1795 | tree fndecl = gimple_call_fndecl (stmt); |
1be38ccb RG |
1796 | switch (DECL_FUNCTION_CODE (fndecl)) |
1797 | { | |
1798 | case BUILT_IN_MALLOC: | |
1799 | case BUILT_IN_REALLOC: | |
1800 | case BUILT_IN_CALLOC: | |
36dc1a88 JJ |
1801 | case BUILT_IN_STRDUP: |
1802 | case BUILT_IN_STRNDUP: | |
1be38ccb RG |
1803 | val.lattice_val = CONSTANT; |
1804 | val.value = build_int_cst (TREE_TYPE (gimple_get_lhs (stmt)), 0); | |
807e902e KZ |
1805 | val.mask = ~((HOST_WIDE_INT) MALLOC_ABI_ALIGNMENT |
1806 | / BITS_PER_UNIT - 1); | |
1be38ccb RG |
1807 | break; |
1808 | ||
1809 | case BUILT_IN_ALLOCA: | |
13e49da9 TV |
1810 | case BUILT_IN_ALLOCA_WITH_ALIGN: |
1811 | align = (DECL_FUNCTION_CODE (fndecl) == BUILT_IN_ALLOCA_WITH_ALIGN | |
1812 | ? TREE_INT_CST_LOW (gimple_call_arg (stmt, 1)) | |
1813 | : BIGGEST_ALIGNMENT); | |
1be38ccb RG |
1814 | val.lattice_val = CONSTANT; |
1815 | val.value = build_int_cst (TREE_TYPE (gimple_get_lhs (stmt)), 0); | |
807e902e | 1816 | val.mask = ~((HOST_WIDE_INT) align / BITS_PER_UNIT - 1); |
1be38ccb RG |
1817 | break; |
1818 | ||
36dc1a88 JJ |
1819 | /* These builtins return their first argument, unmodified. */ |
1820 | case BUILT_IN_MEMCPY: | |
1821 | case BUILT_IN_MEMMOVE: | |
1822 | case BUILT_IN_MEMSET: | |
1823 | case BUILT_IN_STRCPY: | |
1824 | case BUILT_IN_STRNCPY: | |
1825 | case BUILT_IN_MEMCPY_CHK: | |
1826 | case BUILT_IN_MEMMOVE_CHK: | |
1827 | case BUILT_IN_MEMSET_CHK: | |
1828 | case BUILT_IN_STRCPY_CHK: | |
1829 | case BUILT_IN_STRNCPY_CHK: | |
1830 | val = get_value_for_expr (gimple_call_arg (stmt, 0), true); | |
1831 | break; | |
1832 | ||
45d439ac | 1833 | case BUILT_IN_ASSUME_ALIGNED: |
8fcbce72 | 1834 | val = bit_value_assume_aligned (stmt, NULL_TREE, val, false); |
45d439ac JJ |
1835 | break; |
1836 | ||
22869a37 RB |
1837 | case BUILT_IN_ALIGNED_ALLOC: |
1838 | { | |
1839 | tree align = get_constant_value (gimple_call_arg (stmt, 0)); | |
1840 | if (align | |
1841 | && tree_fits_uhwi_p (align)) | |
1842 | { | |
1843 | unsigned HOST_WIDE_INT aligni = tree_to_uhwi (align); | |
1844 | if (aligni > 1 | |
1845 | /* align must be power-of-two */ | |
1846 | && (aligni & (aligni - 1)) == 0) | |
1847 | { | |
1848 | val.lattice_val = CONSTANT; | |
1849 | val.value = build_int_cst (ptr_type_node, 0); | |
807e902e | 1850 | val.mask = -aligni; |
22869a37 RB |
1851 | } |
1852 | } | |
1853 | break; | |
1854 | } | |
1855 | ||
1be38ccb RG |
1856 | default:; |
1857 | } | |
1858 | } | |
8fcbce72 JJ |
1859 | if (is_gimple_call (stmt) && gimple_call_lhs (stmt)) |
1860 | { | |
1861 | tree fntype = gimple_call_fntype (stmt); | |
1862 | if (fntype) | |
1863 | { | |
1864 | tree attrs = lookup_attribute ("assume_aligned", | |
1865 | TYPE_ATTRIBUTES (fntype)); | |
1866 | if (attrs) | |
1867 | val = bit_value_assume_aligned (stmt, attrs, val, false); | |
1868 | attrs = lookup_attribute ("alloc_align", | |
1869 | TYPE_ATTRIBUTES (fntype)); | |
1870 | if (attrs) | |
1871 | val = bit_value_assume_aligned (stmt, attrs, val, true); | |
1872 | } | |
1873 | } | |
0b4b14ac | 1874 | is_constant = (val.lattice_val == CONSTANT); |
00d382a8 RG |
1875 | } |
1876 | ||
c853f62a JJ |
1877 | if (flag_tree_bit_ccp |
1878 | && ((is_constant && TREE_CODE (val.value) == INTEGER_CST) | |
1879 | || (!is_constant && likelyvalue != UNDEFINED)) | |
1880 | && gimple_get_lhs (stmt) | |
1881 | && TREE_CODE (gimple_get_lhs (stmt)) == SSA_NAME) | |
1882 | { | |
1883 | tree lhs = gimple_get_lhs (stmt); | |
807e902e KZ |
1884 | wide_int nonzero_bits = get_nonzero_bits (lhs); |
1885 | if (nonzero_bits != -1) | |
c853f62a JJ |
1886 | { |
1887 | if (!is_constant) | |
1888 | { | |
1889 | val.lattice_val = CONSTANT; | |
1890 | val.value = build_zero_cst (TREE_TYPE (lhs)); | |
807e902e | 1891 | val.mask = extend_mask (nonzero_bits); |
c853f62a JJ |
1892 | is_constant = true; |
1893 | } | |
1894 | else | |
1895 | { | |
807e902e KZ |
1896 | if (wi::bit_and_not (val.value, nonzero_bits) != 0) |
1897 | val.value = wide_int_to_tree (TREE_TYPE (lhs), | |
1898 | nonzero_bits & val.value); | |
1899 | if (nonzero_bits == 0) | |
1900 | val.mask = 0; | |
c853f62a | 1901 | else |
807e902e | 1902 | val.mask = val.mask & extend_mask (nonzero_bits); |
c853f62a JJ |
1903 | } |
1904 | } | |
1905 | } | |
1906 | ||
0b4b14ac | 1907 | if (!is_constant) |
6de9cd9a DN |
1908 | { |
1909 | /* The statement produced a nonconstant value. If the statement | |
0bca51f0 DN |
1910 | had UNDEFINED operands, then the result of the statement |
1911 | should be UNDEFINED. Otherwise, the statement is VARYING. */ | |
106dec71 | 1912 | if (likelyvalue == UNDEFINED) |
0b4b14ac RG |
1913 | { |
1914 | val.lattice_val = likelyvalue; | |
807e902e | 1915 | val.mask = 0; |
0b4b14ac | 1916 | } |
a318e3ac | 1917 | else |
0b4b14ac RG |
1918 | { |
1919 | val.lattice_val = VARYING; | |
807e902e | 1920 | val.mask = -1; |
0b4b14ac | 1921 | } |
a318e3ac | 1922 | |
0bca51f0 | 1923 | val.value = NULL_TREE; |
6de9cd9a | 1924 | } |
750628d8 DN |
1925 | |
1926 | return val; | |
6de9cd9a DN |
1927 | } |
1928 | ||
c203e8a7 | 1929 | typedef hash_table<pointer_hash<gimple_statement_base> > gimple_htab; |
0823efed | 1930 | |
2f31f742 TV |
1931 | /* Given a BUILT_IN_STACK_SAVE value SAVED_VAL, insert a clobber of VAR before |
1932 | each matching BUILT_IN_STACK_RESTORE. Mark visited phis in VISITED. */ | |
1933 | ||
1934 | static void | |
0823efed | 1935 | insert_clobber_before_stack_restore (tree saved_val, tree var, |
c203e8a7 | 1936 | gimple_htab **visited) |
2f31f742 | 1937 | { |
538dd0b7 DM |
1938 | gimple stmt; |
1939 | gassign *clobber_stmt; | |
2f31f742 TV |
1940 | tree clobber; |
1941 | imm_use_iterator iter; | |
1942 | gimple_stmt_iterator i; | |
1943 | gimple *slot; | |
1944 | ||
1945 | FOR_EACH_IMM_USE_STMT (stmt, iter, saved_val) | |
1946 | if (gimple_call_builtin_p (stmt, BUILT_IN_STACK_RESTORE)) | |
1947 | { | |
9771b263 DN |
1948 | clobber = build_constructor (TREE_TYPE (var), |
1949 | NULL); | |
2f31f742 TV |
1950 | TREE_THIS_VOLATILE (clobber) = 1; |
1951 | clobber_stmt = gimple_build_assign (var, clobber); | |
1952 | ||
1953 | i = gsi_for_stmt (stmt); | |
1954 | gsi_insert_before (&i, clobber_stmt, GSI_SAME_STMT); | |
1955 | } | |
1956 | else if (gimple_code (stmt) == GIMPLE_PHI) | |
1957 | { | |
c203e8a7 TS |
1958 | if (!*visited) |
1959 | *visited = new gimple_htab (10); | |
2f31f742 | 1960 | |
c203e8a7 | 1961 | slot = (*visited)->find_slot (stmt, INSERT); |
2f31f742 TV |
1962 | if (*slot != NULL) |
1963 | continue; | |
1964 | ||
1965 | *slot = stmt; | |
1966 | insert_clobber_before_stack_restore (gimple_phi_result (stmt), var, | |
1967 | visited); | |
1968 | } | |
cefce769 EB |
1969 | else if (gimple_assign_ssa_name_copy_p (stmt)) |
1970 | insert_clobber_before_stack_restore (gimple_assign_lhs (stmt), var, | |
1971 | visited); | |
d5e254e1 IE |
1972 | else if (chkp_gimple_call_builtin_p (stmt, BUILT_IN_CHKP_BNDRET)) |
1973 | continue; | |
2f31f742 TV |
1974 | else |
1975 | gcc_assert (is_gimple_debug (stmt)); | |
1976 | } | |
1977 | ||
1978 | /* Advance the iterator to the previous non-debug gimple statement in the same | |
1979 | or dominating basic block. */ | |
1980 | ||
1981 | static inline void | |
1982 | gsi_prev_dom_bb_nondebug (gimple_stmt_iterator *i) | |
1983 | { | |
1984 | basic_block dom; | |
1985 | ||
1986 | gsi_prev_nondebug (i); | |
1987 | while (gsi_end_p (*i)) | |
1988 | { | |
1989 | dom = get_immediate_dominator (CDI_DOMINATORS, i->bb); | |
fefa31b5 | 1990 | if (dom == NULL || dom == ENTRY_BLOCK_PTR_FOR_FN (cfun)) |
2f31f742 TV |
1991 | return; |
1992 | ||
1993 | *i = gsi_last_bb (dom); | |
1994 | } | |
1995 | } | |
1996 | ||
1997 | /* Find a BUILT_IN_STACK_SAVE dominating gsi_stmt (I), and insert | |
b9bebd7f MJ |
1998 | a clobber of VAR before each matching BUILT_IN_STACK_RESTORE. |
1999 | ||
2000 | It is possible that BUILT_IN_STACK_SAVE cannot be find in a dominator when a | |
2001 | previous pass (such as DOM) duplicated it along multiple paths to a BB. In | |
2002 | that case the function gives up without inserting the clobbers. */ | |
2f31f742 TV |
2003 | |
2004 | static void | |
2005 | insert_clobbers_for_var (gimple_stmt_iterator i, tree var) | |
2006 | { | |
2f31f742 TV |
2007 | gimple stmt; |
2008 | tree saved_val; | |
c203e8a7 | 2009 | gimple_htab *visited = NULL; |
2f31f742 | 2010 | |
b9bebd7f | 2011 | for (; !gsi_end_p (i); gsi_prev_dom_bb_nondebug (&i)) |
2f31f742 TV |
2012 | { |
2013 | stmt = gsi_stmt (i); | |
2014 | ||
2015 | if (!gimple_call_builtin_p (stmt, BUILT_IN_STACK_SAVE)) | |
2016 | continue; | |
2f31f742 TV |
2017 | |
2018 | saved_val = gimple_call_lhs (stmt); | |
2019 | if (saved_val == NULL_TREE) | |
2020 | continue; | |
2021 | ||
2022 | insert_clobber_before_stack_restore (saved_val, var, &visited); | |
2023 | break; | |
2024 | } | |
2025 | ||
c203e8a7 | 2026 | delete visited; |
2f31f742 TV |
2027 | } |
2028 | ||
13e49da9 TV |
2029 | /* Detects a __builtin_alloca_with_align with constant size argument. Declares |
2030 | fixed-size array and returns the address, if found, otherwise returns | |
2031 | NULL_TREE. */ | |
1fed1006 TV |
2032 | |
2033 | static tree | |
13e49da9 | 2034 | fold_builtin_alloca_with_align (gimple stmt) |
1fed1006 TV |
2035 | { |
2036 | unsigned HOST_WIDE_INT size, threshold, n_elem; | |
2037 | tree lhs, arg, block, var, elem_type, array_type; | |
1fed1006 TV |
2038 | |
2039 | /* Get lhs. */ | |
2040 | lhs = gimple_call_lhs (stmt); | |
2041 | if (lhs == NULL_TREE) | |
2042 | return NULL_TREE; | |
2043 | ||
2044 | /* Detect constant argument. */ | |
2045 | arg = get_constant_value (gimple_call_arg (stmt, 0)); | |
5d882cc1 RG |
2046 | if (arg == NULL_TREE |
2047 | || TREE_CODE (arg) != INTEGER_CST | |
cc269bb6 | 2048 | || !tree_fits_uhwi_p (arg)) |
1fed1006 | 2049 | return NULL_TREE; |
5d882cc1 | 2050 | |
eb1ce453 | 2051 | size = tree_to_uhwi (arg); |
1fed1006 | 2052 | |
13e49da9 | 2053 | /* Heuristic: don't fold large allocas. */ |
1fed1006 | 2054 | threshold = (unsigned HOST_WIDE_INT)PARAM_VALUE (PARAM_LARGE_STACK_FRAME); |
13e49da9 TV |
2055 | /* In case the alloca is located at function entry, it has the same lifetime |
2056 | as a declared array, so we allow a larger size. */ | |
1fed1006 TV |
2057 | block = gimple_block (stmt); |
2058 | if (!(cfun->after_inlining | |
2059 | && TREE_CODE (BLOCK_SUPERCONTEXT (block)) == FUNCTION_DECL)) | |
2060 | threshold /= 10; | |
2061 | if (size > threshold) | |
2062 | return NULL_TREE; | |
2063 | ||
2064 | /* Declare array. */ | |
2065 | elem_type = build_nonstandard_integer_type (BITS_PER_UNIT, 1); | |
2066 | n_elem = size * 8 / BITS_PER_UNIT; | |
1fed1006 TV |
2067 | array_type = build_array_type_nelts (elem_type, n_elem); |
2068 | var = create_tmp_var (array_type, NULL); | |
13e49da9 | 2069 | DECL_ALIGN (var) = TREE_INT_CST_LOW (gimple_call_arg (stmt, 1)); |
703ffc30 TV |
2070 | { |
2071 | struct ptr_info_def *pi = SSA_NAME_PTR_INFO (lhs); | |
2072 | if (pi != NULL && !pi->pt.anything) | |
2073 | { | |
2074 | bool singleton_p; | |
2075 | unsigned uid; | |
2076 | singleton_p = pt_solution_singleton_p (&pi->pt, &uid); | |
2077 | gcc_assert (singleton_p); | |
2078 | SET_DECL_PT_UID (var, uid); | |
2079 | } | |
2080 | } | |
1fed1006 TV |
2081 | |
2082 | /* Fold alloca to the address of the array. */ | |
2083 | return fold_convert (TREE_TYPE (lhs), build_fold_addr_expr (var)); | |
2084 | } | |
2085 | ||
f61e18ec RG |
2086 | /* Fold the stmt at *GSI with CCP specific information that propagating |
2087 | and regular folding does not catch. */ | |
2088 | ||
2089 | static bool | |
2090 | ccp_fold_stmt (gimple_stmt_iterator *gsi) | |
2091 | { | |
2092 | gimple stmt = gsi_stmt (*gsi); | |
f61e18ec | 2093 | |
830bc550 RG |
2094 | switch (gimple_code (stmt)) |
2095 | { | |
2096 | case GIMPLE_COND: | |
2097 | { | |
538dd0b7 | 2098 | gcond *cond_stmt = as_a <gcond *> (stmt); |
11478306 | 2099 | ccp_prop_value_t val; |
830bc550 RG |
2100 | /* Statement evaluation will handle type mismatches in constants |
2101 | more gracefully than the final propagation. This allows us to | |
2102 | fold more conditionals here. */ | |
2103 | val = evaluate_stmt (stmt); | |
2104 | if (val.lattice_val != CONSTANT | |
807e902e | 2105 | || val.mask != 0) |
830bc550 RG |
2106 | return false; |
2107 | ||
0b4b14ac RG |
2108 | if (dump_file) |
2109 | { | |
2110 | fprintf (dump_file, "Folding predicate "); | |
2111 | print_gimple_expr (dump_file, stmt, 0, 0); | |
2112 | fprintf (dump_file, " to "); | |
2113 | print_generic_expr (dump_file, val.value, 0); | |
2114 | fprintf (dump_file, "\n"); | |
2115 | } | |
2116 | ||
830bc550 | 2117 | if (integer_zerop (val.value)) |
538dd0b7 | 2118 | gimple_cond_make_false (cond_stmt); |
830bc550 | 2119 | else |
538dd0b7 | 2120 | gimple_cond_make_true (cond_stmt); |
f61e18ec | 2121 | |
830bc550 RG |
2122 | return true; |
2123 | } | |
f61e18ec | 2124 | |
830bc550 RG |
2125 | case GIMPLE_CALL: |
2126 | { | |
2127 | tree lhs = gimple_call_lhs (stmt); | |
45a5b21a | 2128 | int flags = gimple_call_flags (stmt); |
84d77ca6 | 2129 | tree val; |
830bc550 RG |
2130 | tree argt; |
2131 | bool changed = false; | |
2132 | unsigned i; | |
2133 | ||
2134 | /* If the call was folded into a constant make sure it goes | |
2135 | away even if we cannot propagate into all uses because of | |
2136 | type issues. */ | |
2137 | if (lhs | |
2138 | && TREE_CODE (lhs) == SSA_NAME | |
45a5b21a JJ |
2139 | && (val = get_constant_value (lhs)) |
2140 | /* Don't optimize away calls that have side-effects. */ | |
2141 | && (flags & (ECF_CONST|ECF_PURE)) != 0 | |
2142 | && (flags & ECF_LOOPING_CONST_OR_PURE) == 0) | |
830bc550 | 2143 | { |
84d77ca6 | 2144 | tree new_rhs = unshare_expr (val); |
eb6b98c7 | 2145 | bool res; |
830bc550 RG |
2146 | if (!useless_type_conversion_p (TREE_TYPE (lhs), |
2147 | TREE_TYPE (new_rhs))) | |
2148 | new_rhs = fold_convert (TREE_TYPE (lhs), new_rhs); | |
eb6b98c7 RG |
2149 | res = update_call_from_tree (gsi, new_rhs); |
2150 | gcc_assert (res); | |
830bc550 RG |
2151 | return true; |
2152 | } | |
2153 | ||
25583c4f RS |
2154 | /* Internal calls provide no argument types, so the extra laxity |
2155 | for normal calls does not apply. */ | |
2156 | if (gimple_call_internal_p (stmt)) | |
2157 | return false; | |
2158 | ||
13e49da9 TV |
2159 | /* The heuristic of fold_builtin_alloca_with_align differs before and |
2160 | after inlining, so we don't require the arg to be changed into a | |
2161 | constant for folding, but just to be constant. */ | |
2162 | if (gimple_call_builtin_p (stmt, BUILT_IN_ALLOCA_WITH_ALIGN)) | |
1fed1006 | 2163 | { |
13e49da9 | 2164 | tree new_rhs = fold_builtin_alloca_with_align (stmt); |
5d882cc1 RG |
2165 | if (new_rhs) |
2166 | { | |
2167 | bool res = update_call_from_tree (gsi, new_rhs); | |
2f31f742 | 2168 | tree var = TREE_OPERAND (TREE_OPERAND (new_rhs, 0),0); |
5d882cc1 | 2169 | gcc_assert (res); |
2f31f742 | 2170 | insert_clobbers_for_var (*gsi, var); |
5d882cc1 RG |
2171 | return true; |
2172 | } | |
1fed1006 TV |
2173 | } |
2174 | ||
830bc550 RG |
2175 | /* Propagate into the call arguments. Compared to replace_uses_in |
2176 | this can use the argument slot types for type verification | |
2177 | instead of the current argument type. We also can safely | |
2178 | drop qualifiers here as we are dealing with constants anyway. */ | |
9bfc434b | 2179 | argt = TYPE_ARG_TYPES (gimple_call_fntype (stmt)); |
830bc550 RG |
2180 | for (i = 0; i < gimple_call_num_args (stmt) && argt; |
2181 | ++i, argt = TREE_CHAIN (argt)) | |
2182 | { | |
2183 | tree arg = gimple_call_arg (stmt, i); | |
2184 | if (TREE_CODE (arg) == SSA_NAME | |
84d77ca6 | 2185 | && (val = get_constant_value (arg)) |
830bc550 RG |
2186 | && useless_type_conversion_p |
2187 | (TYPE_MAIN_VARIANT (TREE_VALUE (argt)), | |
84d77ca6 | 2188 | TYPE_MAIN_VARIANT (TREE_TYPE (val)))) |
830bc550 | 2189 | { |
84d77ca6 | 2190 | gimple_call_set_arg (stmt, i, unshare_expr (val)); |
830bc550 RG |
2191 | changed = true; |
2192 | } | |
2193 | } | |
74e80a24 | 2194 | |
830bc550 RG |
2195 | return changed; |
2196 | } | |
f61e18ec | 2197 | |
5c95f07b RG |
2198 | case GIMPLE_ASSIGN: |
2199 | { | |
2200 | tree lhs = gimple_assign_lhs (stmt); | |
84d77ca6 | 2201 | tree val; |
5c95f07b RG |
2202 | |
2203 | /* If we have a load that turned out to be constant replace it | |
2204 | as we cannot propagate into all uses in all cases. */ | |
2205 | if (gimple_assign_single_p (stmt) | |
2206 | && TREE_CODE (lhs) == SSA_NAME | |
84d77ca6 | 2207 | && (val = get_constant_value (lhs))) |
5c95f07b | 2208 | { |
84d77ca6 | 2209 | tree rhs = unshare_expr (val); |
5c95f07b | 2210 | if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs))) |
70f34814 | 2211 | rhs = fold_build1 (VIEW_CONVERT_EXPR, TREE_TYPE (lhs), rhs); |
5c95f07b RG |
2212 | gimple_assign_set_rhs_from_tree (gsi, rhs); |
2213 | return true; | |
2214 | } | |
2215 | ||
2216 | return false; | |
2217 | } | |
2218 | ||
830bc550 RG |
2219 | default: |
2220 | return false; | |
2221 | } | |
f61e18ec RG |
2222 | } |
2223 | ||
750628d8 | 2224 | /* Visit the assignment statement STMT. Set the value of its LHS to the |
0bca51f0 DN |
2225 | value computed by the RHS and store LHS in *OUTPUT_P. If STMT |
2226 | creates virtual definitions, set the value of each new name to that | |
726a989a RB |
2227 | of the RHS (if we can derive a constant out of the RHS). |
2228 | Value-returning call statements also perform an assignment, and | |
2229 | are handled here. */ | |
6de9cd9a | 2230 | |
750628d8 | 2231 | static enum ssa_prop_result |
726a989a | 2232 | visit_assignment (gimple stmt, tree *output_p) |
6de9cd9a | 2233 | { |
11478306 | 2234 | ccp_prop_value_t val; |
0bca51f0 | 2235 | enum ssa_prop_result retval; |
6de9cd9a | 2236 | |
726a989a | 2237 | tree lhs = gimple_get_lhs (stmt); |
6de9cd9a | 2238 | |
726a989a RB |
2239 | gcc_assert (gimple_code (stmt) != GIMPLE_CALL |
2240 | || gimple_call_lhs (stmt) != NULL_TREE); | |
2241 | ||
84d77ca6 RG |
2242 | if (gimple_assign_single_p (stmt) |
2243 | && gimple_assign_rhs_code (stmt) == SSA_NAME) | |
2244 | /* For a simple copy operation, we copy the lattice values. */ | |
2245 | val = *get_value (gimple_assign_rhs1 (stmt)); | |
750628d8 | 2246 | else |
726a989a RB |
2247 | /* Evaluate the statement, which could be |
2248 | either a GIMPLE_ASSIGN or a GIMPLE_CALL. */ | |
87e1e42b | 2249 | val = evaluate_stmt (stmt); |
6de9cd9a | 2250 | |
0bca51f0 | 2251 | retval = SSA_PROP_NOT_INTERESTING; |
6de9cd9a | 2252 | |
750628d8 | 2253 | /* Set the lattice value of the statement's output. */ |
0bca51f0 | 2254 | if (TREE_CODE (lhs) == SSA_NAME) |
6de9cd9a | 2255 | { |
0bca51f0 DN |
2256 | /* If STMT is an assignment to an SSA_NAME, we only have one |
2257 | value to set. */ | |
2258 | if (set_lattice_value (lhs, val)) | |
2259 | { | |
2260 | *output_p = lhs; | |
2261 | if (val.lattice_val == VARYING) | |
2262 | retval = SSA_PROP_VARYING; | |
2263 | else | |
2264 | retval = SSA_PROP_INTERESTING; | |
2265 | } | |
6de9cd9a | 2266 | } |
0bca51f0 DN |
2267 | |
2268 | return retval; | |
6de9cd9a DN |
2269 | } |
2270 | ||
6de9cd9a | 2271 | |
750628d8 DN |
2272 | /* Visit the conditional statement STMT. Return SSA_PROP_INTERESTING |
2273 | if it can determine which edge will be taken. Otherwise, return | |
2274 | SSA_PROP_VARYING. */ | |
2275 | ||
2276 | static enum ssa_prop_result | |
726a989a | 2277 | visit_cond_stmt (gimple stmt, edge *taken_edge_p) |
6de9cd9a | 2278 | { |
11478306 | 2279 | ccp_prop_value_t val; |
750628d8 DN |
2280 | basic_block block; |
2281 | ||
726a989a | 2282 | block = gimple_bb (stmt); |
750628d8 | 2283 | val = evaluate_stmt (stmt); |
0b4b14ac | 2284 | if (val.lattice_val != CONSTANT |
807e902e | 2285 | || val.mask != 0) |
0b4b14ac | 2286 | return SSA_PROP_VARYING; |
750628d8 DN |
2287 | |
2288 | /* Find which edge out of the conditional block will be taken and add it | |
2289 | to the worklist. If no single edge can be determined statically, | |
2290 | return SSA_PROP_VARYING to feed all the outgoing edges to the | |
2291 | propagation engine. */ | |
0b4b14ac | 2292 | *taken_edge_p = find_taken_edge (block, val.value); |
750628d8 DN |
2293 | if (*taken_edge_p) |
2294 | return SSA_PROP_INTERESTING; | |
2295 | else | |
2296 | return SSA_PROP_VARYING; | |
6de9cd9a DN |
2297 | } |
2298 | ||
6de9cd9a | 2299 | |
750628d8 DN |
2300 | /* Evaluate statement STMT. If the statement produces an output value and |
2301 | its evaluation changes the lattice value of its output, return | |
2302 | SSA_PROP_INTERESTING and set *OUTPUT_P to the SSA_NAME holding the | |
2303 | output value. | |
b8698a0f | 2304 | |
750628d8 DN |
2305 | If STMT is a conditional branch and we can determine its truth |
2306 | value, set *TAKEN_EDGE_P accordingly. If STMT produces a varying | |
2307 | value, return SSA_PROP_VARYING. */ | |
6de9cd9a | 2308 | |
750628d8 | 2309 | static enum ssa_prop_result |
726a989a | 2310 | ccp_visit_stmt (gimple stmt, edge *taken_edge_p, tree *output_p) |
750628d8 | 2311 | { |
750628d8 DN |
2312 | tree def; |
2313 | ssa_op_iter iter; | |
6de9cd9a | 2314 | |
750628d8 | 2315 | if (dump_file && (dump_flags & TDF_DETAILS)) |
6de9cd9a | 2316 | { |
0bca51f0 | 2317 | fprintf (dump_file, "\nVisiting statement:\n"); |
726a989a | 2318 | print_gimple_stmt (dump_file, stmt, 0, dump_flags); |
6de9cd9a | 2319 | } |
6de9cd9a | 2320 | |
726a989a | 2321 | switch (gimple_code (stmt)) |
6de9cd9a | 2322 | { |
726a989a RB |
2323 | case GIMPLE_ASSIGN: |
2324 | /* If the statement is an assignment that produces a single | |
2325 | output value, evaluate its RHS to see if the lattice value of | |
2326 | its output has changed. */ | |
2327 | return visit_assignment (stmt, output_p); | |
2328 | ||
2329 | case GIMPLE_CALL: | |
2330 | /* A value-returning call also performs an assignment. */ | |
2331 | if (gimple_call_lhs (stmt) != NULL_TREE) | |
2332 | return visit_assignment (stmt, output_p); | |
2333 | break; | |
2334 | ||
2335 | case GIMPLE_COND: | |
2336 | case GIMPLE_SWITCH: | |
2337 | /* If STMT is a conditional branch, see if we can determine | |
2338 | which branch will be taken. */ | |
2339 | /* FIXME. It appears that we should be able to optimize | |
2340 | computed GOTOs here as well. */ | |
2341 | return visit_cond_stmt (stmt, taken_edge_p); | |
2342 | ||
2343 | default: | |
2344 | break; | |
6de9cd9a | 2345 | } |
6de9cd9a | 2346 | |
750628d8 DN |
2347 | /* Any other kind of statement is not interesting for constant |
2348 | propagation and, therefore, not worth simulating. */ | |
750628d8 DN |
2349 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2350 | fprintf (dump_file, "No interesting values produced. Marked VARYING.\n"); | |
6de9cd9a | 2351 | |
750628d8 DN |
2352 | /* Definitions made by statements other than assignments to |
2353 | SSA_NAMEs represent unknown modifications to their outputs. | |
2354 | Mark them VARYING. */ | |
0bca51f0 DN |
2355 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS) |
2356 | { | |
11478306 | 2357 | ccp_prop_value_t v = { VARYING, NULL_TREE, -1 }; |
0bca51f0 DN |
2358 | set_lattice_value (def, v); |
2359 | } | |
6de9cd9a | 2360 | |
750628d8 DN |
2361 | return SSA_PROP_VARYING; |
2362 | } | |
6de9cd9a | 2363 | |
6de9cd9a | 2364 | |
0bca51f0 | 2365 | /* Main entry point for SSA Conditional Constant Propagation. */ |
750628d8 | 2366 | |
3253eafb | 2367 | static unsigned int |
dce2b2f6 | 2368 | do_ssa_ccp (void) |
750628d8 | 2369 | { |
2f31f742 TV |
2370 | unsigned int todo = 0; |
2371 | calculate_dominance_info (CDI_DOMINATORS); | |
750628d8 DN |
2372 | ccp_initialize (); |
2373 | ssa_propagate (ccp_visit_stmt, ccp_visit_phi_node); | |
3253eafb | 2374 | if (ccp_finalize ()) |
c0e50f72 | 2375 | todo = (TODO_cleanup_cfg | TODO_update_ssa); |
2f31f742 TV |
2376 | free_dominance_info (CDI_DOMINATORS); |
2377 | return todo; | |
6de9cd9a DN |
2378 | } |
2379 | ||
173b818d | 2380 | |
27a4cd48 DM |
2381 | namespace { |
2382 | ||
2383 | const pass_data pass_data_ccp = | |
750628d8 | 2384 | { |
27a4cd48 DM |
2385 | GIMPLE_PASS, /* type */ |
2386 | "ccp", /* name */ | |
2387 | OPTGROUP_NONE, /* optinfo_flags */ | |
27a4cd48 DM |
2388 | TV_TREE_CCP, /* tv_id */ |
2389 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
2390 | 0, /* properties_provided */ | |
2391 | 0, /* properties_destroyed */ | |
2392 | 0, /* todo_flags_start */ | |
3bea341f | 2393 | TODO_update_address_taken, /* todo_flags_finish */ |
750628d8 | 2394 | }; |
6de9cd9a | 2395 | |
27a4cd48 DM |
2396 | class pass_ccp : public gimple_opt_pass |
2397 | { | |
2398 | public: | |
c3284718 RS |
2399 | pass_ccp (gcc::context *ctxt) |
2400 | : gimple_opt_pass (pass_data_ccp, ctxt) | |
27a4cd48 DM |
2401 | {} |
2402 | ||
2403 | /* opt_pass methods: */ | |
65d3284b | 2404 | opt_pass * clone () { return new pass_ccp (m_ctxt); } |
1a3d085c | 2405 | virtual bool gate (function *) { return flag_tree_ccp != 0; } |
be55bfe6 | 2406 | virtual unsigned int execute (function *) { return do_ssa_ccp (); } |
27a4cd48 DM |
2407 | |
2408 | }; // class pass_ccp | |
2409 | ||
2410 | } // anon namespace | |
2411 | ||
2412 | gimple_opt_pass * | |
2413 | make_pass_ccp (gcc::context *ctxt) | |
2414 | { | |
2415 | return new pass_ccp (ctxt); | |
2416 | } | |
2417 | ||
6de9cd9a | 2418 | |
726a989a | 2419 | |
cb8e078d JJ |
2420 | /* Try to optimize out __builtin_stack_restore. Optimize it out |
2421 | if there is another __builtin_stack_restore in the same basic | |
2422 | block and no calls or ASM_EXPRs are in between, or if this block's | |
2423 | only outgoing edge is to EXIT_BLOCK and there are no calls or | |
2424 | ASM_EXPRs after this __builtin_stack_restore. */ | |
2425 | ||
2426 | static tree | |
726a989a | 2427 | optimize_stack_restore (gimple_stmt_iterator i) |
cb8e078d | 2428 | { |
ff9d1adc RH |
2429 | tree callee; |
2430 | gimple stmt; | |
726a989a RB |
2431 | |
2432 | basic_block bb = gsi_bb (i); | |
2433 | gimple call = gsi_stmt (i); | |
cb8e078d | 2434 | |
726a989a RB |
2435 | if (gimple_code (call) != GIMPLE_CALL |
2436 | || gimple_call_num_args (call) != 1 | |
2437 | || TREE_CODE (gimple_call_arg (call, 0)) != SSA_NAME | |
2438 | || !POINTER_TYPE_P (TREE_TYPE (gimple_call_arg (call, 0)))) | |
cb8e078d JJ |
2439 | return NULL_TREE; |
2440 | ||
726a989a | 2441 | for (gsi_next (&i); !gsi_end_p (i); gsi_next (&i)) |
cb8e078d | 2442 | { |
726a989a RB |
2443 | stmt = gsi_stmt (i); |
2444 | if (gimple_code (stmt) == GIMPLE_ASM) | |
cb8e078d | 2445 | return NULL_TREE; |
726a989a | 2446 | if (gimple_code (stmt) != GIMPLE_CALL) |
cb8e078d JJ |
2447 | continue; |
2448 | ||
726a989a | 2449 | callee = gimple_call_fndecl (stmt); |
12f9ddbc RG |
2450 | if (!callee |
2451 | || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL | |
2452 | /* All regular builtins are ok, just obviously not alloca. */ | |
13e49da9 TV |
2453 | || DECL_FUNCTION_CODE (callee) == BUILT_IN_ALLOCA |
2454 | || DECL_FUNCTION_CODE (callee) == BUILT_IN_ALLOCA_WITH_ALIGN) | |
cb8e078d JJ |
2455 | return NULL_TREE; |
2456 | ||
2457 | if (DECL_FUNCTION_CODE (callee) == BUILT_IN_STACK_RESTORE) | |
ff9d1adc | 2458 | goto second_stack_restore; |
cb8e078d JJ |
2459 | } |
2460 | ||
ff9d1adc | 2461 | if (!gsi_end_p (i)) |
cb8e078d JJ |
2462 | return NULL_TREE; |
2463 | ||
ff9d1adc RH |
2464 | /* Allow one successor of the exit block, or zero successors. */ |
2465 | switch (EDGE_COUNT (bb->succs)) | |
2466 | { | |
2467 | case 0: | |
2468 | break; | |
2469 | case 1: | |
fefa31b5 | 2470 | if (single_succ_edge (bb)->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) |
ff9d1adc RH |
2471 | return NULL_TREE; |
2472 | break; | |
2473 | default: | |
2474 | return NULL_TREE; | |
2475 | } | |
2476 | second_stack_restore: | |
cb8e078d | 2477 | |
ff9d1adc RH |
2478 | /* If there's exactly one use, then zap the call to __builtin_stack_save. |
2479 | If there are multiple uses, then the last one should remove the call. | |
2480 | In any case, whether the call to __builtin_stack_save can be removed | |
2481 | or not is irrelevant to removing the call to __builtin_stack_restore. */ | |
2482 | if (has_single_use (gimple_call_arg (call, 0))) | |
2483 | { | |
2484 | gimple stack_save = SSA_NAME_DEF_STMT (gimple_call_arg (call, 0)); | |
2485 | if (is_gimple_call (stack_save)) | |
2486 | { | |
2487 | callee = gimple_call_fndecl (stack_save); | |
2488 | if (callee | |
2489 | && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL | |
2490 | && DECL_FUNCTION_CODE (callee) == BUILT_IN_STACK_SAVE) | |
2491 | { | |
2492 | gimple_stmt_iterator stack_save_gsi; | |
2493 | tree rhs; | |
cb8e078d | 2494 | |
ff9d1adc RH |
2495 | stack_save_gsi = gsi_for_stmt (stack_save); |
2496 | rhs = build_int_cst (TREE_TYPE (gimple_call_arg (call, 0)), 0); | |
2497 | update_call_from_tree (&stack_save_gsi, rhs); | |
2498 | } | |
2499 | } | |
2500 | } | |
cb8e078d | 2501 | |
726a989a | 2502 | /* No effect, so the statement will be deleted. */ |
cb8e078d JJ |
2503 | return integer_zero_node; |
2504 | } | |
726a989a | 2505 | |
d7bd8aeb JJ |
2506 | /* If va_list type is a simple pointer and nothing special is needed, |
2507 | optimize __builtin_va_start (&ap, 0) into ap = __builtin_next_arg (0), | |
2508 | __builtin_va_end (&ap) out as NOP and __builtin_va_copy into a simple | |
2509 | pointer assignment. */ | |
2510 | ||
2511 | static tree | |
726a989a | 2512 | optimize_stdarg_builtin (gimple call) |
d7bd8aeb | 2513 | { |
35cbb299 | 2514 | tree callee, lhs, rhs, cfun_va_list; |
d7bd8aeb | 2515 | bool va_list_simple_ptr; |
db3927fb | 2516 | location_t loc = gimple_location (call); |
d7bd8aeb | 2517 | |
726a989a | 2518 | if (gimple_code (call) != GIMPLE_CALL) |
d7bd8aeb JJ |
2519 | return NULL_TREE; |
2520 | ||
726a989a | 2521 | callee = gimple_call_fndecl (call); |
35cbb299 KT |
2522 | |
2523 | cfun_va_list = targetm.fn_abi_va_list (callee); | |
2524 | va_list_simple_ptr = POINTER_TYPE_P (cfun_va_list) | |
2525 | && (TREE_TYPE (cfun_va_list) == void_type_node | |
2526 | || TREE_TYPE (cfun_va_list) == char_type_node); | |
2527 | ||
d7bd8aeb JJ |
2528 | switch (DECL_FUNCTION_CODE (callee)) |
2529 | { | |
2530 | case BUILT_IN_VA_START: | |
2531 | if (!va_list_simple_ptr | |
2532 | || targetm.expand_builtin_va_start != NULL | |
f25a65f5 | 2533 | || !builtin_decl_explicit_p (BUILT_IN_NEXT_ARG)) |
d7bd8aeb JJ |
2534 | return NULL_TREE; |
2535 | ||
726a989a | 2536 | if (gimple_call_num_args (call) != 2) |
d7bd8aeb JJ |
2537 | return NULL_TREE; |
2538 | ||
726a989a | 2539 | lhs = gimple_call_arg (call, 0); |
d7bd8aeb JJ |
2540 | if (!POINTER_TYPE_P (TREE_TYPE (lhs)) |
2541 | || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs))) | |
35cbb299 | 2542 | != TYPE_MAIN_VARIANT (cfun_va_list)) |
d7bd8aeb | 2543 | return NULL_TREE; |
b8698a0f | 2544 | |
db3927fb | 2545 | lhs = build_fold_indirect_ref_loc (loc, lhs); |
e79983f4 | 2546 | rhs = build_call_expr_loc (loc, builtin_decl_explicit (BUILT_IN_NEXT_ARG), |
726a989a | 2547 | 1, integer_zero_node); |
db3927fb | 2548 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); |
d7bd8aeb JJ |
2549 | return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs); |
2550 | ||
2551 | case BUILT_IN_VA_COPY: | |
2552 | if (!va_list_simple_ptr) | |
2553 | return NULL_TREE; | |
2554 | ||
726a989a | 2555 | if (gimple_call_num_args (call) != 2) |
d7bd8aeb JJ |
2556 | return NULL_TREE; |
2557 | ||
726a989a | 2558 | lhs = gimple_call_arg (call, 0); |
d7bd8aeb JJ |
2559 | if (!POINTER_TYPE_P (TREE_TYPE (lhs)) |
2560 | || TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (lhs))) | |
35cbb299 | 2561 | != TYPE_MAIN_VARIANT (cfun_va_list)) |
d7bd8aeb JJ |
2562 | return NULL_TREE; |
2563 | ||
db3927fb | 2564 | lhs = build_fold_indirect_ref_loc (loc, lhs); |
726a989a | 2565 | rhs = gimple_call_arg (call, 1); |
d7bd8aeb | 2566 | if (TYPE_MAIN_VARIANT (TREE_TYPE (rhs)) |
35cbb299 | 2567 | != TYPE_MAIN_VARIANT (cfun_va_list)) |
d7bd8aeb JJ |
2568 | return NULL_TREE; |
2569 | ||
db3927fb | 2570 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); |
d7bd8aeb JJ |
2571 | return build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, rhs); |
2572 | ||
2573 | case BUILT_IN_VA_END: | |
726a989a | 2574 | /* No effect, so the statement will be deleted. */ |
d7bd8aeb JJ |
2575 | return integer_zero_node; |
2576 | ||
2577 | default: | |
2578 | gcc_unreachable (); | |
2579 | } | |
2580 | } | |
726a989a | 2581 | |
c61e5cc1 TV |
2582 | /* Attemp to make the block of __builtin_unreachable I unreachable by changing |
2583 | the incoming jumps. Return true if at least one jump was changed. */ | |
2584 | ||
2585 | static bool | |
2586 | optimize_unreachable (gimple_stmt_iterator i) | |
2587 | { | |
2588 | basic_block bb = gsi_bb (i); | |
2589 | gimple_stmt_iterator gsi; | |
2590 | gimple stmt; | |
2591 | edge_iterator ei; | |
2592 | edge e; | |
2593 | bool ret; | |
2594 | ||
4088b790 MP |
2595 | if (flag_sanitize & SANITIZE_UNREACHABLE) |
2596 | return false; | |
2597 | ||
c61e5cc1 TV |
2598 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
2599 | { | |
2600 | stmt = gsi_stmt (gsi); | |
2601 | ||
2602 | if (is_gimple_debug (stmt)) | |
2603 | continue; | |
2604 | ||
538dd0b7 | 2605 | if (glabel *label_stmt = dyn_cast <glabel *> (stmt)) |
c61e5cc1 TV |
2606 | { |
2607 | /* Verify we do not need to preserve the label. */ | |
538dd0b7 | 2608 | if (FORCED_LABEL (gimple_label_label (label_stmt))) |
c61e5cc1 TV |
2609 | return false; |
2610 | ||
2611 | continue; | |
2612 | } | |
2613 | ||
2614 | /* Only handle the case that __builtin_unreachable is the first statement | |
2615 | in the block. We rely on DCE to remove stmts without side-effects | |
2616 | before __builtin_unreachable. */ | |
2617 | if (gsi_stmt (gsi) != gsi_stmt (i)) | |
2618 | return false; | |
2619 | } | |
2620 | ||
2621 | ret = false; | |
2622 | FOR_EACH_EDGE (e, ei, bb->preds) | |
2623 | { | |
2624 | gsi = gsi_last_bb (e->src); | |
cd356d96 UW |
2625 | if (gsi_end_p (gsi)) |
2626 | continue; | |
c61e5cc1 | 2627 | |
cd356d96 | 2628 | stmt = gsi_stmt (gsi); |
538dd0b7 | 2629 | if (gcond *cond_stmt = dyn_cast <gcond *> (stmt)) |
c61e5cc1 TV |
2630 | { |
2631 | if (e->flags & EDGE_TRUE_VALUE) | |
538dd0b7 | 2632 | gimple_cond_make_false (cond_stmt); |
c61e5cc1 | 2633 | else if (e->flags & EDGE_FALSE_VALUE) |
538dd0b7 | 2634 | gimple_cond_make_true (cond_stmt); |
c61e5cc1 TV |
2635 | else |
2636 | gcc_unreachable (); | |
538dd0b7 | 2637 | update_stmt (cond_stmt); |
c61e5cc1 TV |
2638 | } |
2639 | else | |
2640 | { | |
2641 | /* Todo: handle other cases, f.i. switch statement. */ | |
2642 | continue; | |
2643 | } | |
2644 | ||
2645 | ret = true; | |
2646 | } | |
2647 | ||
2648 | return ret; | |
2649 | } | |
2650 | ||
6de9cd9a DN |
2651 | /* A simple pass that attempts to fold all builtin functions. This pass |
2652 | is run after we've propagated as many constants as we can. */ | |
2653 | ||
be55bfe6 TS |
2654 | namespace { |
2655 | ||
2656 | const pass_data pass_data_fold_builtins = | |
2657 | { | |
2658 | GIMPLE_PASS, /* type */ | |
2659 | "fab", /* name */ | |
2660 | OPTGROUP_NONE, /* optinfo_flags */ | |
be55bfe6 TS |
2661 | TV_NONE, /* tv_id */ |
2662 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
2663 | 0, /* properties_provided */ | |
2664 | 0, /* properties_destroyed */ | |
2665 | 0, /* todo_flags_start */ | |
3bea341f | 2666 | TODO_update_ssa, /* todo_flags_finish */ |
be55bfe6 TS |
2667 | }; |
2668 | ||
2669 | class pass_fold_builtins : public gimple_opt_pass | |
2670 | { | |
2671 | public: | |
2672 | pass_fold_builtins (gcc::context *ctxt) | |
2673 | : gimple_opt_pass (pass_data_fold_builtins, ctxt) | |
2674 | {} | |
2675 | ||
2676 | /* opt_pass methods: */ | |
2677 | opt_pass * clone () { return new pass_fold_builtins (m_ctxt); } | |
2678 | virtual unsigned int execute (function *); | |
2679 | ||
2680 | }; // class pass_fold_builtins | |
2681 | ||
2682 | unsigned int | |
2683 | pass_fold_builtins::execute (function *fun) | |
6de9cd9a | 2684 | { |
a7d6ba24 | 2685 | bool cfg_changed = false; |
6de9cd9a | 2686 | basic_block bb; |
7b0e48fb | 2687 | unsigned int todoflags = 0; |
b8698a0f | 2688 | |
be55bfe6 | 2689 | FOR_EACH_BB_FN (bb, fun) |
6de9cd9a | 2690 | { |
726a989a RB |
2691 | gimple_stmt_iterator i; |
2692 | for (i = gsi_start_bb (bb); !gsi_end_p (i); ) | |
6de9cd9a | 2693 | { |
726a989a | 2694 | gimple stmt, old_stmt; |
3daa26d0 | 2695 | tree callee; |
10a0d495 | 2696 | enum built_in_function fcode; |
6de9cd9a | 2697 | |
726a989a RB |
2698 | stmt = gsi_stmt (i); |
2699 | ||
2700 | if (gimple_code (stmt) != GIMPLE_CALL) | |
10a0d495 | 2701 | { |
f223bb13 JJ |
2702 | /* Remove all *ssaname_N ={v} {CLOBBER}; stmts, |
2703 | after the last GIMPLE DSE they aren't needed and might | |
2704 | unnecessarily keep the SSA_NAMEs live. */ | |
2705 | if (gimple_clobber_p (stmt)) | |
2706 | { | |
2707 | tree lhs = gimple_assign_lhs (stmt); | |
2708 | if (TREE_CODE (lhs) == MEM_REF | |
2709 | && TREE_CODE (TREE_OPERAND (lhs, 0)) == SSA_NAME) | |
2710 | { | |
2711 | unlink_stmt_vdef (stmt); | |
2712 | gsi_remove (&i, true); | |
2713 | release_defs (stmt); | |
2714 | continue; | |
2715 | } | |
2716 | } | |
726a989a | 2717 | gsi_next (&i); |
10a0d495 JJ |
2718 | continue; |
2719 | } | |
3daa26d0 | 2720 | |
726a989a | 2721 | callee = gimple_call_fndecl (stmt); |
6de9cd9a | 2722 | if (!callee || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL) |
10a0d495 | 2723 | { |
726a989a | 2724 | gsi_next (&i); |
10a0d495 JJ |
2725 | continue; |
2726 | } | |
53a8f709 | 2727 | |
3daa26d0 RB |
2728 | fcode = DECL_FUNCTION_CODE (callee); |
2729 | if (fold_stmt (&i)) | |
2730 | ; | |
2731 | else | |
2732 | { | |
2733 | tree result = NULL_TREE; | |
2734 | switch (DECL_FUNCTION_CODE (callee)) | |
2735 | { | |
2736 | case BUILT_IN_CONSTANT_P: | |
2737 | /* Resolve __builtin_constant_p. If it hasn't been | |
2738 | folded to integer_one_node by now, it's fairly | |
2739 | certain that the value simply isn't constant. */ | |
2740 | result = integer_zero_node; | |
2741 | break; | |
53a8f709 | 2742 | |
3daa26d0 RB |
2743 | case BUILT_IN_ASSUME_ALIGNED: |
2744 | /* Remove __builtin_assume_aligned. */ | |
2745 | result = gimple_call_arg (stmt, 0); | |
2746 | break; | |
6de9cd9a | 2747 | |
3daa26d0 RB |
2748 | case BUILT_IN_STACK_RESTORE: |
2749 | result = optimize_stack_restore (i); | |
2750 | if (result) | |
2751 | break; | |
2752 | gsi_next (&i); | |
2753 | continue; | |
45d439ac | 2754 | |
3daa26d0 RB |
2755 | case BUILT_IN_UNREACHABLE: |
2756 | if (optimize_unreachable (i)) | |
2757 | cfg_changed = true; | |
d7bd8aeb | 2758 | break; |
d7bd8aeb | 2759 | |
3daa26d0 RB |
2760 | case BUILT_IN_VA_START: |
2761 | case BUILT_IN_VA_END: | |
2762 | case BUILT_IN_VA_COPY: | |
2763 | /* These shouldn't be folded before pass_stdarg. */ | |
2764 | result = optimize_stdarg_builtin (stmt); | |
2765 | if (result) | |
2766 | break; | |
2767 | /* FALLTHRU */ | |
c61e5cc1 | 2768 | |
3daa26d0 RB |
2769 | default:; |
2770 | } | |
cb8e078d | 2771 | |
3daa26d0 RB |
2772 | if (!result) |
2773 | { | |
2774 | gsi_next (&i); | |
2775 | continue; | |
2776 | } | |
6de9cd9a | 2777 | |
3daa26d0 RB |
2778 | if (!update_call_from_tree (&i, result)) |
2779 | gimplify_and_update_call_from_tree (&i, result); | |
2780 | } | |
2781 | ||
2782 | todoflags |= TODO_update_address_taken; | |
c61e5cc1 | 2783 | |
6de9cd9a DN |
2784 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2785 | { | |
2786 | fprintf (dump_file, "Simplified\n "); | |
726a989a | 2787 | print_gimple_stmt (dump_file, stmt, 0, dump_flags); |
6de9cd9a DN |
2788 | } |
2789 | ||
726a989a | 2790 | old_stmt = stmt; |
726a989a | 2791 | stmt = gsi_stmt (i); |
cff4e50d | 2792 | update_stmt (stmt); |
cfaab3a9 | 2793 | |
726a989a RB |
2794 | if (maybe_clean_or_replace_eh_stmt (old_stmt, stmt) |
2795 | && gimple_purge_dead_eh_edges (bb)) | |
a7d6ba24 | 2796 | cfg_changed = true; |
6de9cd9a DN |
2797 | |
2798 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2799 | { | |
2800 | fprintf (dump_file, "to\n "); | |
726a989a | 2801 | print_gimple_stmt (dump_file, stmt, 0, dump_flags); |
6de9cd9a DN |
2802 | fprintf (dump_file, "\n"); |
2803 | } | |
10a0d495 JJ |
2804 | |
2805 | /* Retry the same statement if it changed into another | |
2806 | builtin, there might be new opportunities now. */ | |
726a989a | 2807 | if (gimple_code (stmt) != GIMPLE_CALL) |
10a0d495 | 2808 | { |
726a989a | 2809 | gsi_next (&i); |
10a0d495 JJ |
2810 | continue; |
2811 | } | |
726a989a | 2812 | callee = gimple_call_fndecl (stmt); |
10a0d495 | 2813 | if (!callee |
726a989a | 2814 | || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL |
10a0d495 | 2815 | || DECL_FUNCTION_CODE (callee) == fcode) |
726a989a | 2816 | gsi_next (&i); |
6de9cd9a DN |
2817 | } |
2818 | } | |
b8698a0f | 2819 | |
a7d6ba24 | 2820 | /* Delete unreachable blocks. */ |
7b0e48fb DB |
2821 | if (cfg_changed) |
2822 | todoflags |= TODO_cleanup_cfg; | |
b8698a0f | 2823 | |
7b0e48fb | 2824 | return todoflags; |
6de9cd9a DN |
2825 | } |
2826 | ||
27a4cd48 DM |
2827 | } // anon namespace |
2828 | ||
2829 | gimple_opt_pass * | |
2830 | make_pass_fold_builtins (gcc::context *ctxt) | |
2831 | { | |
2832 | return new pass_fold_builtins (ctxt); | |
2833 | } |