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6de9cd9a | 1 | /* SSA Dominator optimizations for trees |
5624e564 | 2 | Copyright (C) 2001-2015 Free Software Foundation, Inc. |
6de9cd9a DN |
3 | Contributed by Diego Novillo <dnovillo@redhat.com> |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9dcd6f09 | 9 | the Free Software Foundation; either version 3, or (at your option) |
6de9cd9a DN |
10 | any later version. |
11 | ||
12 | GCC is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
9dcd6f09 NC |
18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
6de9cd9a DN |
20 | |
21 | #include "config.h" | |
22 | #include "system.h" | |
23 | #include "coretypes.h" | |
4a8fb1a1 | 24 | #include "hash-table.h" |
6de9cd9a | 25 | #include "tm.h" |
40e23961 MC |
26 | #include "hash-set.h" |
27 | #include "machmode.h" | |
28 | #include "vec.h" | |
29 | #include "double-int.h" | |
30 | #include "input.h" | |
31 | #include "alias.h" | |
32 | #include "symtab.h" | |
33 | #include "wide-int.h" | |
34 | #include "inchash.h" | |
35 | #include "real.h" | |
6de9cd9a | 36 | #include "tree.h" |
40e23961 | 37 | #include "fold-const.h" |
d8a2d370 | 38 | #include "stor-layout.h" |
6de9cd9a | 39 | #include "flags.h" |
6de9cd9a | 40 | #include "tm_p.h" |
60393bbc | 41 | #include "predict.h" |
83685514 AM |
42 | #include "hard-reg-set.h" |
43 | #include "input.h" | |
6de9cd9a | 44 | #include "function.h" |
60393bbc AM |
45 | #include "dominance.h" |
46 | #include "cfg.h" | |
47 | #include "cfganal.h" | |
48 | #include "basic-block.h" | |
49 | #include "cfgloop.h" | |
50 | #include "inchash.h" | |
cf835838 | 51 | #include "gimple-pretty-print.h" |
2fb9a547 AM |
52 | #include "tree-ssa-alias.h" |
53 | #include "internal-fn.h" | |
54 | #include "gimple-fold.h" | |
55 | #include "tree-eh.h" | |
56 | #include "gimple-expr.h" | |
57 | #include "is-a.h" | |
442b4905 | 58 | #include "gimple.h" |
5be5c238 | 59 | #include "gimple-iterator.h" |
442b4905 AM |
60 | #include "gimple-ssa.h" |
61 | #include "tree-cfg.h" | |
62 | #include "tree-phinodes.h" | |
63 | #include "ssa-iterators.h" | |
d8a2d370 | 64 | #include "stringpool.h" |
442b4905 AM |
65 | #include "tree-ssanames.h" |
66 | #include "tree-into-ssa.h" | |
6de9cd9a | 67 | #include "domwalk.h" |
6de9cd9a | 68 | #include "tree-pass.h" |
c7f90219 | 69 | #include "tree-ssa-propagate.h" |
5254eac4 | 70 | #include "tree-ssa-threadupdate.h" |
6de9cd9a | 71 | #include "langhooks.h" |
43f31be5 | 72 | #include "params.h" |
4484a35a AM |
73 | #include "tree-ssa-threadedge.h" |
74 | #include "tree-ssa-dom.h" | |
2bc10537 | 75 | #include "inchash.h" |
b00734df | 76 | #include "gimplify.h" |
6de9cd9a DN |
77 | |
78 | /* This file implements optimizations on the dominator tree. */ | |
79 | ||
726a989a RB |
80 | /* Representation of a "naked" right-hand-side expression, to be used |
81 | in recording available expressions in the expression hash table. */ | |
82 | ||
83 | enum expr_kind | |
84 | { | |
85 | EXPR_SINGLE, | |
86 | EXPR_UNARY, | |
87 | EXPR_BINARY, | |
0354c0c7 | 88 | EXPR_TERNARY, |
13a3e5b6 BS |
89 | EXPR_CALL, |
90 | EXPR_PHI | |
726a989a RB |
91 | }; |
92 | ||
93 | struct hashable_expr | |
94 | { | |
95 | tree type; | |
96 | enum expr_kind kind; | |
97 | union { | |
98 | struct { tree rhs; } single; | |
99 | struct { enum tree_code op; tree opnd; } unary; | |
0354c0c7 BS |
100 | struct { enum tree_code op; tree opnd0, opnd1; } binary; |
101 | struct { enum tree_code op; tree opnd0, opnd1, opnd2; } ternary; | |
538dd0b7 | 102 | struct { gcall *fn_from; bool pure; size_t nargs; tree *args; } call; |
13a3e5b6 | 103 | struct { size_t nargs; tree *args; } phi; |
726a989a RB |
104 | } ops; |
105 | }; | |
106 | ||
107 | /* Structure for recording known values of a conditional expression | |
108 | at the exits from its block. */ | |
109 | ||
fd4a760e | 110 | typedef struct cond_equivalence_s |
726a989a RB |
111 | { |
112 | struct hashable_expr cond; | |
113 | tree value; | |
fd4a760e RG |
114 | } cond_equivalence; |
115 | ||
efea75f9 JL |
116 | |
117 | /* Structure for recording edge equivalences as well as any pending | |
118 | edge redirections during the dominator optimizer. | |
119 | ||
120 | Computing and storing the edge equivalences instead of creating | |
121 | them on-demand can save significant amounts of time, particularly | |
b8698a0f | 122 | for pathological cases involving switch statements. |
efea75f9 JL |
123 | |
124 | These structures live for a single iteration of the dominator | |
125 | optimizer in the edge's AUX field. At the end of an iteration we | |
126 | free each of these structures and update the AUX field to point | |
127 | to any requested redirection target (the code for updating the | |
128 | CFG and SSA graph for edge redirection expects redirection edge | |
129 | targets to be in the AUX field for each edge. */ | |
130 | ||
131 | struct edge_info | |
132 | { | |
133 | /* If this edge creates a simple equivalence, the LHS and RHS of | |
134 | the equivalence will be stored here. */ | |
135 | tree lhs; | |
136 | tree rhs; | |
137 | ||
138 | /* Traversing an edge may also indicate one or more particular conditions | |
fd4a760e | 139 | are true or false. */ |
9771b263 | 140 | vec<cond_equivalence> cond_equivalences; |
efea75f9 JL |
141 | }; |
142 | ||
48732f23 JL |
143 | /* Stack of available expressions in AVAIL_EXPRs. Each block pushes any |
144 | expressions it enters into the hash table along with a marker entry | |
b3a27618 | 145 | (null). When we finish processing the block, we pop off entries and |
48732f23 JL |
146 | remove the expressions from the global hash table until we hit the |
147 | marker. */ | |
726a989a | 148 | typedef struct expr_hash_elt * expr_hash_elt_t; |
726a989a | 149 | |
b00734df | 150 | static vec<std::pair<expr_hash_elt_t, expr_hash_elt_t> > avail_exprs_stack; |
48732f23 | 151 | |
726a989a | 152 | /* Structure for entries in the expression hash table. */ |
56b043c8 | 153 | |
6de9cd9a DN |
154 | struct expr_hash_elt |
155 | { | |
156 | /* The value (lhs) of this expression. */ | |
157 | tree lhs; | |
158 | ||
159 | /* The expression (rhs) we want to record. */ | |
726a989a | 160 | struct hashable_expr expr; |
6de9cd9a | 161 | |
b00734df RB |
162 | /* The virtual operand associated with the nearest dominating stmt |
163 | loading from or storing to expr. */ | |
164 | tree vop; | |
6de9cd9a | 165 | |
726a989a | 166 | /* The hash value for RHS. */ |
6de9cd9a | 167 | hashval_t hash; |
726a989a RB |
168 | |
169 | /* A unique stamp, typically the address of the hash | |
170 | element itself, used in removing entries from the table. */ | |
171 | struct expr_hash_elt *stamp; | |
6de9cd9a DN |
172 | }; |
173 | ||
4a8fb1a1 LC |
174 | /* Hashtable helpers. */ |
175 | ||
176 | static bool hashable_expr_equal_p (const struct hashable_expr *, | |
177 | const struct hashable_expr *); | |
178 | static void free_expr_hash_elt (void *); | |
179 | ||
180 | struct expr_elt_hasher | |
181 | { | |
84baa4b9 TS |
182 | typedef expr_hash_elt *value_type; |
183 | typedef expr_hash_elt *compare_type; | |
184 | typedef int store_values_directly; | |
185 | static inline hashval_t hash (const value_type &); | |
186 | static inline bool equal (const value_type &, const compare_type &); | |
187 | static inline void remove (value_type &); | |
4a8fb1a1 LC |
188 | }; |
189 | ||
190 | inline hashval_t | |
84baa4b9 | 191 | expr_elt_hasher::hash (const value_type &p) |
4a8fb1a1 LC |
192 | { |
193 | return p->hash; | |
194 | } | |
195 | ||
196 | inline bool | |
84baa4b9 | 197 | expr_elt_hasher::equal (const value_type &p1, const compare_type &p2) |
4a8fb1a1 | 198 | { |
4a8fb1a1 LC |
199 | const struct hashable_expr *expr1 = &p1->expr; |
200 | const struct expr_hash_elt *stamp1 = p1->stamp; | |
4a8fb1a1 LC |
201 | const struct hashable_expr *expr2 = &p2->expr; |
202 | const struct expr_hash_elt *stamp2 = p2->stamp; | |
203 | ||
204 | /* This case should apply only when removing entries from the table. */ | |
205 | if (stamp1 == stamp2) | |
206 | return true; | |
207 | ||
b00734df | 208 | if (p1->hash != p2->hash) |
4a8fb1a1 LC |
209 | return false; |
210 | ||
211 | /* In case of a collision, both RHS have to be identical and have the | |
212 | same VUSE operands. */ | |
213 | if (hashable_expr_equal_p (expr1, expr2) | |
214 | && types_compatible_p (expr1->type, expr2->type)) | |
b00734df | 215 | return true; |
4a8fb1a1 LC |
216 | |
217 | return false; | |
218 | } | |
219 | ||
220 | /* Delete an expr_hash_elt and reclaim its storage. */ | |
221 | ||
222 | inline void | |
84baa4b9 | 223 | expr_elt_hasher::remove (value_type &element) |
4a8fb1a1 LC |
224 | { |
225 | free_expr_hash_elt (element); | |
226 | } | |
227 | ||
228 | /* Hash table with expressions made available during the renaming process. | |
229 | When an assignment of the form X_i = EXPR is found, the statement is | |
230 | stored in this table. If the same expression EXPR is later found on the | |
231 | RHS of another statement, it is replaced with X_i (thus performing | |
232 | global redundancy elimination). Similarly as we pass through conditionals | |
233 | we record the conditional itself as having either a true or false value | |
234 | in this table. */ | |
c203e8a7 | 235 | static hash_table<expr_elt_hasher> *avail_exprs; |
4a8fb1a1 | 236 | |
b5fefcf6 JL |
237 | /* Stack of dest,src pairs that need to be restored during finalization. |
238 | ||
239 | A NULL entry is used to mark the end of pairs which need to be | |
240 | restored during finalization of this block. */ | |
9771b263 | 241 | static vec<tree> const_and_copies_stack; |
b5fefcf6 | 242 | |
6de9cd9a DN |
243 | /* Track whether or not we have changed the control flow graph. */ |
244 | static bool cfg_altered; | |
245 | ||
1eaba2f2 | 246 | /* Bitmap of blocks that have had EH statements cleaned. We should |
f6fe65dc | 247 | remove their dead edges eventually. */ |
1eaba2f2 RH |
248 | static bitmap need_eh_cleanup; |
249 | ||
6de9cd9a DN |
250 | /* Statistics for dominator optimizations. */ |
251 | struct opt_stats_d | |
252 | { | |
253 | long num_stmts; | |
254 | long num_exprs_considered; | |
255 | long num_re; | |
0bca51f0 DN |
256 | long num_const_prop; |
257 | long num_copy_prop; | |
6de9cd9a DN |
258 | }; |
259 | ||
23530866 JL |
260 | static struct opt_stats_d opt_stats; |
261 | ||
6de9cd9a | 262 | /* Local functions. */ |
ccf5c864 | 263 | static void optimize_stmt (basic_block, gimple_stmt_iterator); |
726a989a | 264 | static tree lookup_avail_expr (gimple, bool); |
6de9cd9a | 265 | static hashval_t avail_expr_hash (const void *); |
c203e8a7 TS |
266 | static void htab_statistics (FILE *, |
267 | const hash_table<expr_elt_hasher> &); | |
fd4a760e | 268 | static void record_cond (cond_equivalence *); |
b5fefcf6 JL |
269 | static void record_const_or_copy (tree, tree); |
270 | static void record_equality (tree, tree); | |
efea75f9 JL |
271 | static void record_equivalences_from_phis (basic_block); |
272 | static void record_equivalences_from_incoming_edge (basic_block); | |
87c93592 | 273 | static void eliminate_redundant_computations (gimple_stmt_iterator *); |
726a989a | 274 | static void record_equivalences_from_stmt (gimple, int); |
48732f23 | 275 | static void remove_local_expressions_from_table (void); |
b5fefcf6 | 276 | static void restore_vars_to_original_value (void); |
28c008bb | 277 | static edge single_incoming_edge_ignoring_loop_edges (basic_block); |
6de9cd9a | 278 | |
0bca51f0 | 279 | |
726a989a RB |
280 | /* Given a statement STMT, initialize the hash table element pointed to |
281 | by ELEMENT. */ | |
282 | ||
283 | static void | |
284 | initialize_hash_element (gimple stmt, tree lhs, | |
285 | struct expr_hash_elt *element) | |
286 | { | |
287 | enum gimple_code code = gimple_code (stmt); | |
288 | struct hashable_expr *expr = &element->expr; | |
289 | ||
290 | if (code == GIMPLE_ASSIGN) | |
291 | { | |
292 | enum tree_code subcode = gimple_assign_rhs_code (stmt); | |
293 | ||
726a989a RB |
294 | switch (get_gimple_rhs_class (subcode)) |
295 | { | |
296 | case GIMPLE_SINGLE_RHS: | |
0354c0c7 | 297 | expr->kind = EXPR_SINGLE; |
e2c9010a | 298 | expr->type = TREE_TYPE (gimple_assign_rhs1 (stmt)); |
0354c0c7 BS |
299 | expr->ops.single.rhs = gimple_assign_rhs1 (stmt); |
300 | break; | |
726a989a | 301 | case GIMPLE_UNARY_RHS: |
0354c0c7 | 302 | expr->kind = EXPR_UNARY; |
726a989a | 303 | expr->type = TREE_TYPE (gimple_assign_lhs (stmt)); |
d822570f | 304 | if (CONVERT_EXPR_CODE_P (subcode)) |
625a9766 | 305 | subcode = NOP_EXPR; |
0354c0c7 BS |
306 | expr->ops.unary.op = subcode; |
307 | expr->ops.unary.opnd = gimple_assign_rhs1 (stmt); | |
308 | break; | |
726a989a | 309 | case GIMPLE_BINARY_RHS: |
0354c0c7 | 310 | expr->kind = EXPR_BINARY; |
726a989a | 311 | expr->type = TREE_TYPE (gimple_assign_lhs (stmt)); |
0354c0c7 BS |
312 | expr->ops.binary.op = subcode; |
313 | expr->ops.binary.opnd0 = gimple_assign_rhs1 (stmt); | |
314 | expr->ops.binary.opnd1 = gimple_assign_rhs2 (stmt); | |
315 | break; | |
316 | case GIMPLE_TERNARY_RHS: | |
317 | expr->kind = EXPR_TERNARY; | |
318 | expr->type = TREE_TYPE (gimple_assign_lhs (stmt)); | |
319 | expr->ops.ternary.op = subcode; | |
320 | expr->ops.ternary.opnd0 = gimple_assign_rhs1 (stmt); | |
321 | expr->ops.ternary.opnd1 = gimple_assign_rhs2 (stmt); | |
322 | expr->ops.ternary.opnd2 = gimple_assign_rhs3 (stmt); | |
323 | break; | |
726a989a RB |
324 | default: |
325 | gcc_unreachable (); | |
326 | } | |
327 | } | |
328 | else if (code == GIMPLE_COND) | |
329 | { | |
330 | expr->type = boolean_type_node; | |
331 | expr->kind = EXPR_BINARY; | |
332 | expr->ops.binary.op = gimple_cond_code (stmt); | |
333 | expr->ops.binary.opnd0 = gimple_cond_lhs (stmt); | |
334 | expr->ops.binary.opnd1 = gimple_cond_rhs (stmt); | |
335 | } | |
538dd0b7 | 336 | else if (gcall *call_stmt = dyn_cast <gcall *> (stmt)) |
726a989a | 337 | { |
538dd0b7 | 338 | size_t nargs = gimple_call_num_args (call_stmt); |
726a989a RB |
339 | size_t i; |
340 | ||
538dd0b7 | 341 | gcc_assert (gimple_call_lhs (call_stmt)); |
726a989a | 342 | |
538dd0b7 | 343 | expr->type = TREE_TYPE (gimple_call_lhs (call_stmt)); |
726a989a | 344 | expr->kind = EXPR_CALL; |
538dd0b7 | 345 | expr->ops.call.fn_from = call_stmt; |
726a989a | 346 | |
538dd0b7 | 347 | if (gimple_call_flags (call_stmt) & (ECF_CONST | ECF_PURE)) |
726a989a | 348 | expr->ops.call.pure = true; |
b8698a0f | 349 | else |
726a989a RB |
350 | expr->ops.call.pure = false; |
351 | ||
352 | expr->ops.call.nargs = nargs; | |
13a3e5b6 | 353 | expr->ops.call.args = XCNEWVEC (tree, nargs); |
726a989a | 354 | for (i = 0; i < nargs; i++) |
538dd0b7 | 355 | expr->ops.call.args[i] = gimple_call_arg (call_stmt, i); |
726a989a | 356 | } |
538dd0b7 | 357 | else if (gswitch *swtch_stmt = dyn_cast <gswitch *> (stmt)) |
726a989a | 358 | { |
538dd0b7 | 359 | expr->type = TREE_TYPE (gimple_switch_index (swtch_stmt)); |
726a989a | 360 | expr->kind = EXPR_SINGLE; |
538dd0b7 | 361 | expr->ops.single.rhs = gimple_switch_index (swtch_stmt); |
726a989a RB |
362 | } |
363 | else if (code == GIMPLE_GOTO) | |
364 | { | |
365 | expr->type = TREE_TYPE (gimple_goto_dest (stmt)); | |
366 | expr->kind = EXPR_SINGLE; | |
367 | expr->ops.single.rhs = gimple_goto_dest (stmt); | |
368 | } | |
13a3e5b6 BS |
369 | else if (code == GIMPLE_PHI) |
370 | { | |
371 | size_t nargs = gimple_phi_num_args (stmt); | |
372 | size_t i; | |
373 | ||
374 | expr->type = TREE_TYPE (gimple_phi_result (stmt)); | |
375 | expr->kind = EXPR_PHI; | |
376 | expr->ops.phi.nargs = nargs; | |
377 | expr->ops.phi.args = XCNEWVEC (tree, nargs); | |
378 | ||
379 | for (i = 0; i < nargs; i++) | |
380 | expr->ops.phi.args[i] = gimple_phi_arg_def (stmt, i); | |
381 | } | |
726a989a RB |
382 | else |
383 | gcc_unreachable (); | |
384 | ||
385 | element->lhs = lhs; | |
b00734df | 386 | element->vop = gimple_vuse (stmt); |
726a989a RB |
387 | element->hash = avail_expr_hash (element); |
388 | element->stamp = element; | |
389 | } | |
390 | ||
391 | /* Given a conditional expression COND as a tree, initialize | |
392 | a hashable_expr expression EXPR. The conditional must be a | |
393 | comparison or logical negation. A constant or a variable is | |
394 | not permitted. */ | |
395 | ||
396 | static void | |
397 | initialize_expr_from_cond (tree cond, struct hashable_expr *expr) | |
398 | { | |
399 | expr->type = boolean_type_node; | |
b8698a0f | 400 | |
726a989a RB |
401 | if (COMPARISON_CLASS_P (cond)) |
402 | { | |
403 | expr->kind = EXPR_BINARY; | |
404 | expr->ops.binary.op = TREE_CODE (cond); | |
405 | expr->ops.binary.opnd0 = TREE_OPERAND (cond, 0); | |
406 | expr->ops.binary.opnd1 = TREE_OPERAND (cond, 1); | |
407 | } | |
408 | else if (TREE_CODE (cond) == TRUTH_NOT_EXPR) | |
409 | { | |
410 | expr->kind = EXPR_UNARY; | |
411 | expr->ops.unary.op = TRUTH_NOT_EXPR; | |
412 | expr->ops.unary.opnd = TREE_OPERAND (cond, 0); | |
413 | } | |
414 | else | |
415 | gcc_unreachable (); | |
416 | } | |
417 | ||
418 | /* Given a hashable_expr expression EXPR and an LHS, | |
419 | initialize the hash table element pointed to by ELEMENT. */ | |
420 | ||
421 | static void | |
422 | initialize_hash_element_from_expr (struct hashable_expr *expr, | |
423 | tree lhs, | |
424 | struct expr_hash_elt *element) | |
425 | { | |
426 | element->expr = *expr; | |
427 | element->lhs = lhs; | |
b00734df | 428 | element->vop = NULL_TREE; |
726a989a RB |
429 | element->hash = avail_expr_hash (element); |
430 | element->stamp = element; | |
431 | } | |
432 | ||
433 | /* Compare two hashable_expr structures for equivalence. | |
434 | They are considered equivalent when the the expressions | |
435 | they denote must necessarily be equal. The logic is intended | |
436 | to follow that of operand_equal_p in fold-const.c */ | |
437 | ||
438 | static bool | |
439 | hashable_expr_equal_p (const struct hashable_expr *expr0, | |
440 | const struct hashable_expr *expr1) | |
441 | { | |
442 | tree type0 = expr0->type; | |
443 | tree type1 = expr1->type; | |
444 | ||
445 | /* If either type is NULL, there is nothing to check. */ | |
446 | if ((type0 == NULL_TREE) ^ (type1 == NULL_TREE)) | |
447 | return false; | |
448 | ||
449 | /* If both types don't have the same signedness, precision, and mode, | |
450 | then we can't consider them equal. */ | |
451 | if (type0 != type1 | |
452 | && (TREE_CODE (type0) == ERROR_MARK | |
453 | || TREE_CODE (type1) == ERROR_MARK | |
454 | || TYPE_UNSIGNED (type0) != TYPE_UNSIGNED (type1) | |
455 | || TYPE_PRECISION (type0) != TYPE_PRECISION (type1) | |
456 | || TYPE_MODE (type0) != TYPE_MODE (type1))) | |
457 | return false; | |
458 | ||
459 | if (expr0->kind != expr1->kind) | |
460 | return false; | |
461 | ||
462 | switch (expr0->kind) | |
463 | { | |
464 | case EXPR_SINGLE: | |
465 | return operand_equal_p (expr0->ops.single.rhs, | |
466 | expr1->ops.single.rhs, 0); | |
467 | ||
468 | case EXPR_UNARY: | |
469 | if (expr0->ops.unary.op != expr1->ops.unary.op) | |
470 | return false; | |
471 | ||
1a87cf0c | 472 | if ((CONVERT_EXPR_CODE_P (expr0->ops.unary.op) |
726a989a RB |
473 | || expr0->ops.unary.op == NON_LVALUE_EXPR) |
474 | && TYPE_UNSIGNED (expr0->type) != TYPE_UNSIGNED (expr1->type)) | |
475 | return false; | |
476 | ||
477 | return operand_equal_p (expr0->ops.unary.opnd, | |
478 | expr1->ops.unary.opnd, 0); | |
479 | ||
480 | case EXPR_BINARY: | |
0354c0c7 BS |
481 | if (expr0->ops.binary.op != expr1->ops.binary.op) |
482 | return false; | |
483 | ||
484 | if (operand_equal_p (expr0->ops.binary.opnd0, | |
485 | expr1->ops.binary.opnd0, 0) | |
486 | && operand_equal_p (expr0->ops.binary.opnd1, | |
487 | expr1->ops.binary.opnd1, 0)) | |
488 | return true; | |
489 | ||
490 | /* For commutative ops, allow the other order. */ | |
491 | return (commutative_tree_code (expr0->ops.binary.op) | |
492 | && operand_equal_p (expr0->ops.binary.opnd0, | |
493 | expr1->ops.binary.opnd1, 0) | |
494 | && operand_equal_p (expr0->ops.binary.opnd1, | |
495 | expr1->ops.binary.opnd0, 0)); | |
496 | ||
497 | case EXPR_TERNARY: | |
498 | if (expr0->ops.ternary.op != expr1->ops.ternary.op | |
499 | || !operand_equal_p (expr0->ops.ternary.opnd2, | |
500 | expr1->ops.ternary.opnd2, 0)) | |
501 | return false; | |
502 | ||
503 | if (operand_equal_p (expr0->ops.ternary.opnd0, | |
504 | expr1->ops.ternary.opnd0, 0) | |
505 | && operand_equal_p (expr0->ops.ternary.opnd1, | |
506 | expr1->ops.ternary.opnd1, 0)) | |
507 | return true; | |
508 | ||
509 | /* For commutative ops, allow the other order. */ | |
510 | return (commutative_ternary_tree_code (expr0->ops.ternary.op) | |
511 | && operand_equal_p (expr0->ops.ternary.opnd0, | |
512 | expr1->ops.ternary.opnd1, 0) | |
513 | && operand_equal_p (expr0->ops.ternary.opnd1, | |
514 | expr1->ops.ternary.opnd0, 0)); | |
726a989a RB |
515 | |
516 | case EXPR_CALL: | |
517 | { | |
518 | size_t i; | |
519 | ||
520 | /* If the calls are to different functions, then they | |
521 | clearly cannot be equal. */ | |
25583c4f RS |
522 | if (!gimple_call_same_target_p (expr0->ops.call.fn_from, |
523 | expr1->ops.call.fn_from)) | |
726a989a RB |
524 | return false; |
525 | ||
526 | if (! expr0->ops.call.pure) | |
527 | return false; | |
528 | ||
529 | if (expr0->ops.call.nargs != expr1->ops.call.nargs) | |
530 | return false; | |
531 | ||
532 | for (i = 0; i < expr0->ops.call.nargs; i++) | |
533 | if (! operand_equal_p (expr0->ops.call.args[i], | |
534 | expr1->ops.call.args[i], 0)) | |
535 | return false; | |
536 | ||
7eab31ed EB |
537 | if (stmt_could_throw_p (expr0->ops.call.fn_from)) |
538 | { | |
539 | int lp0 = lookup_stmt_eh_lp (expr0->ops.call.fn_from); | |
540 | int lp1 = lookup_stmt_eh_lp (expr1->ops.call.fn_from); | |
541 | if ((lp0 > 0 || lp1 > 0) && lp0 != lp1) | |
542 | return false; | |
543 | } | |
544 | ||
726a989a RB |
545 | return true; |
546 | } | |
b8698a0f | 547 | |
13a3e5b6 BS |
548 | case EXPR_PHI: |
549 | { | |
550 | size_t i; | |
551 | ||
552 | if (expr0->ops.phi.nargs != expr1->ops.phi.nargs) | |
553 | return false; | |
554 | ||
555 | for (i = 0; i < expr0->ops.phi.nargs; i++) | |
556 | if (! operand_equal_p (expr0->ops.phi.args[i], | |
557 | expr1->ops.phi.args[i], 0)) | |
558 | return false; | |
559 | ||
560 | return true; | |
561 | } | |
562 | ||
726a989a RB |
563 | default: |
564 | gcc_unreachable (); | |
565 | } | |
566 | } | |
567 | ||
862d0b35 | 568 | /* Generate a hash value for a pair of expressions. This can be used |
2bc10537 | 569 | iteratively by passing a previous result in HSTATE. |
862d0b35 DN |
570 | |
571 | The same hash value is always returned for a given pair of expressions, | |
572 | regardless of the order in which they are presented. This is useful in | |
573 | hashing the operands of commutative functions. */ | |
574 | ||
2bc10537 | 575 | namespace inchash |
862d0b35 | 576 | { |
862d0b35 | 577 | |
2bc10537 AK |
578 | static void |
579 | add_expr_commutative (const_tree t1, const_tree t2, hash &hstate) | |
580 | { | |
581 | hash one, two; | |
862d0b35 | 582 | |
2bc10537 AK |
583 | inchash::add_expr (t1, one); |
584 | inchash::add_expr (t2, two); | |
585 | hstate.add_commutative (one, two); | |
862d0b35 DN |
586 | } |
587 | ||
726a989a RB |
588 | /* Compute a hash value for a hashable_expr value EXPR and a |
589 | previously accumulated hash value VAL. If two hashable_expr | |
590 | values compare equal with hashable_expr_equal_p, they must | |
591 | hash to the same value, given an identical value of VAL. | |
2bc10537 | 592 | The logic is intended to follow inchash::add_expr in tree.c. */ |
726a989a | 593 | |
2bc10537 AK |
594 | static void |
595 | add_hashable_expr (const struct hashable_expr *expr, hash &hstate) | |
726a989a RB |
596 | { |
597 | switch (expr->kind) | |
598 | { | |
599 | case EXPR_SINGLE: | |
2bc10537 | 600 | inchash::add_expr (expr->ops.single.rhs, hstate); |
726a989a RB |
601 | break; |
602 | ||
603 | case EXPR_UNARY: | |
2bc10537 | 604 | hstate.add_object (expr->ops.unary.op); |
726a989a RB |
605 | |
606 | /* Make sure to include signedness in the hash computation. | |
607 | Don't hash the type, that can lead to having nodes which | |
608 | compare equal according to operand_equal_p, but which | |
609 | have different hash codes. */ | |
1a87cf0c | 610 | if (CONVERT_EXPR_CODE_P (expr->ops.unary.op) |
726a989a | 611 | || expr->ops.unary.op == NON_LVALUE_EXPR) |
2bc10537 | 612 | hstate.add_int (TYPE_UNSIGNED (expr->type)); |
726a989a | 613 | |
2bc10537 | 614 | inchash::add_expr (expr->ops.unary.opnd, hstate); |
726a989a RB |
615 | break; |
616 | ||
617 | case EXPR_BINARY: | |
2bc10537 | 618 | hstate.add_object (expr->ops.binary.op); |
726a989a | 619 | if (commutative_tree_code (expr->ops.binary.op)) |
2bc10537 AK |
620 | inchash::add_expr_commutative (expr->ops.binary.opnd0, |
621 | expr->ops.binary.opnd1, hstate); | |
726a989a RB |
622 | else |
623 | { | |
2bc10537 AK |
624 | inchash::add_expr (expr->ops.binary.opnd0, hstate); |
625 | inchash::add_expr (expr->ops.binary.opnd1, hstate); | |
726a989a RB |
626 | } |
627 | break; | |
628 | ||
0354c0c7 | 629 | case EXPR_TERNARY: |
2bc10537 | 630 | hstate.add_object (expr->ops.ternary.op); |
0354c0c7 | 631 | if (commutative_ternary_tree_code (expr->ops.ternary.op)) |
2bc10537 AK |
632 | inchash::add_expr_commutative (expr->ops.ternary.opnd0, |
633 | expr->ops.ternary.opnd1, hstate); | |
0354c0c7 BS |
634 | else |
635 | { | |
2bc10537 AK |
636 | inchash::add_expr (expr->ops.ternary.opnd0, hstate); |
637 | inchash::add_expr (expr->ops.ternary.opnd1, hstate); | |
0354c0c7 | 638 | } |
2bc10537 | 639 | inchash::add_expr (expr->ops.ternary.opnd2, hstate); |
0354c0c7 BS |
640 | break; |
641 | ||
726a989a RB |
642 | case EXPR_CALL: |
643 | { | |
644 | size_t i; | |
645 | enum tree_code code = CALL_EXPR; | |
538dd0b7 | 646 | gcall *fn_from; |
726a989a | 647 | |
2bc10537 | 648 | hstate.add_object (code); |
25583c4f RS |
649 | fn_from = expr->ops.call.fn_from; |
650 | if (gimple_call_internal_p (fn_from)) | |
2bc10537 | 651 | hstate.merge_hash ((hashval_t) gimple_call_internal_fn (fn_from)); |
25583c4f | 652 | else |
2bc10537 | 653 | inchash::add_expr (gimple_call_fn (fn_from), hstate); |
726a989a | 654 | for (i = 0; i < expr->ops.call.nargs; i++) |
2bc10537 | 655 | inchash::add_expr (expr->ops.call.args[i], hstate); |
726a989a RB |
656 | } |
657 | break; | |
b8698a0f | 658 | |
13a3e5b6 BS |
659 | case EXPR_PHI: |
660 | { | |
661 | size_t i; | |
662 | ||
663 | for (i = 0; i < expr->ops.phi.nargs; i++) | |
2bc10537 | 664 | inchash::add_expr (expr->ops.phi.args[i], hstate); |
13a3e5b6 BS |
665 | } |
666 | break; | |
667 | ||
726a989a RB |
668 | default: |
669 | gcc_unreachable (); | |
670 | } | |
2bc10537 | 671 | } |
726a989a | 672 | |
726a989a RB |
673 | } |
674 | ||
675 | /* Print a diagnostic dump of an expression hash table entry. */ | |
676 | ||
677 | static void | |
678 | print_expr_hash_elt (FILE * stream, const struct expr_hash_elt *element) | |
679 | { | |
b00734df | 680 | fprintf (stream, "STMT "); |
726a989a RB |
681 | |
682 | if (element->lhs) | |
683 | { | |
684 | print_generic_expr (stream, element->lhs, 0); | |
685 | fprintf (stream, " = "); | |
686 | } | |
b8698a0f | 687 | |
726a989a RB |
688 | switch (element->expr.kind) |
689 | { | |
690 | case EXPR_SINGLE: | |
691 | print_generic_expr (stream, element->expr.ops.single.rhs, 0); | |
692 | break; | |
693 | ||
694 | case EXPR_UNARY: | |
5806f481 | 695 | fprintf (stream, "%s ", get_tree_code_name (element->expr.ops.unary.op)); |
726a989a RB |
696 | print_generic_expr (stream, element->expr.ops.unary.opnd, 0); |
697 | break; | |
698 | ||
699 | case EXPR_BINARY: | |
700 | print_generic_expr (stream, element->expr.ops.binary.opnd0, 0); | |
5806f481 | 701 | fprintf (stream, " %s ", get_tree_code_name (element->expr.ops.binary.op)); |
726a989a RB |
702 | print_generic_expr (stream, element->expr.ops.binary.opnd1, 0); |
703 | break; | |
704 | ||
0354c0c7 | 705 | case EXPR_TERNARY: |
5806f481 | 706 | fprintf (stream, " %s <", get_tree_code_name (element->expr.ops.ternary.op)); |
0354c0c7 BS |
707 | print_generic_expr (stream, element->expr.ops.ternary.opnd0, 0); |
708 | fputs (", ", stream); | |
709 | print_generic_expr (stream, element->expr.ops.ternary.opnd1, 0); | |
710 | fputs (", ", stream); | |
711 | print_generic_expr (stream, element->expr.ops.ternary.opnd2, 0); | |
712 | fputs (">", stream); | |
713 | break; | |
714 | ||
726a989a RB |
715 | case EXPR_CALL: |
716 | { | |
717 | size_t i; | |
718 | size_t nargs = element->expr.ops.call.nargs; | |
538dd0b7 | 719 | gcall *fn_from; |
25583c4f RS |
720 | |
721 | fn_from = element->expr.ops.call.fn_from; | |
722 | if (gimple_call_internal_p (fn_from)) | |
723 | fputs (internal_fn_name (gimple_call_internal_fn (fn_from)), | |
724 | stream); | |
725 | else | |
726 | print_generic_expr (stream, gimple_call_fn (fn_from), 0); | |
726a989a RB |
727 | fprintf (stream, " ("); |
728 | for (i = 0; i < nargs; i++) | |
729 | { | |
730 | print_generic_expr (stream, element->expr.ops.call.args[i], 0); | |
731 | if (i + 1 < nargs) | |
732 | fprintf (stream, ", "); | |
733 | } | |
734 | fprintf (stream, ")"); | |
735 | } | |
736 | break; | |
13a3e5b6 BS |
737 | |
738 | case EXPR_PHI: | |
739 | { | |
740 | size_t i; | |
741 | size_t nargs = element->expr.ops.phi.nargs; | |
742 | ||
743 | fprintf (stream, "PHI <"); | |
744 | for (i = 0; i < nargs; i++) | |
745 | { | |
746 | print_generic_expr (stream, element->expr.ops.phi.args[i], 0); | |
747 | if (i + 1 < nargs) | |
748 | fprintf (stream, ", "); | |
749 | } | |
750 | fprintf (stream, ">"); | |
751 | } | |
752 | break; | |
726a989a | 753 | } |
726a989a | 754 | |
b00734df | 755 | if (element->vop) |
726a989a | 756 | { |
b00734df RB |
757 | fprintf (stream, " with "); |
758 | print_generic_expr (stream, element->vop, 0); | |
726a989a | 759 | } |
b00734df RB |
760 | |
761 | fprintf (stream, "\n"); | |
726a989a RB |
762 | } |
763 | ||
b6db991c | 764 | /* Delete variable sized pieces of the expr_hash_elt ELEMENT. */ |
726a989a RB |
765 | |
766 | static void | |
b6db991c | 767 | free_expr_hash_elt_contents (struct expr_hash_elt *element) |
726a989a | 768 | { |
726a989a RB |
769 | if (element->expr.kind == EXPR_CALL) |
770 | free (element->expr.ops.call.args); | |
b6db991c | 771 | else if (element->expr.kind == EXPR_PHI) |
13a3e5b6 | 772 | free (element->expr.ops.phi.args); |
b6db991c RG |
773 | } |
774 | ||
775 | /* Delete an expr_hash_elt and reclaim its storage. */ | |
13a3e5b6 | 776 | |
b6db991c RG |
777 | static void |
778 | free_expr_hash_elt (void *elt) | |
779 | { | |
780 | struct expr_hash_elt *element = ((struct expr_hash_elt *)elt); | |
781 | free_expr_hash_elt_contents (element); | |
726a989a RB |
782 | free (element); |
783 | } | |
784 | ||
efea75f9 JL |
785 | /* Allocate an EDGE_INFO for edge E and attach it to E. |
786 | Return the new EDGE_INFO structure. */ | |
787 | ||
788 | static struct edge_info * | |
789 | allocate_edge_info (edge e) | |
790 | { | |
791 | struct edge_info *edge_info; | |
792 | ||
e1111e8e | 793 | edge_info = XCNEW (struct edge_info); |
efea75f9 JL |
794 | |
795 | e->aux = edge_info; | |
796 | return edge_info; | |
797 | } | |
798 | ||
799 | /* Free all EDGE_INFO structures associated with edges in the CFG. | |
cbb1cada | 800 | If a particular edge can be threaded, copy the redirection |
efea75f9 JL |
801 | target from the EDGE_INFO structure into the edge's AUX field |
802 | as required by code to update the CFG and SSA graph for | |
803 | jump threading. */ | |
804 | ||
805 | static void | |
806 | free_all_edge_infos (void) | |
807 | { | |
808 | basic_block bb; | |
809 | edge_iterator ei; | |
810 | edge e; | |
811 | ||
11cd3bed | 812 | FOR_EACH_BB_FN (bb, cfun) |
efea75f9 JL |
813 | { |
814 | FOR_EACH_EDGE (e, ei, bb->preds) | |
815 | { | |
e1111e8e | 816 | struct edge_info *edge_info = (struct edge_info *) e->aux; |
efea75f9 JL |
817 | |
818 | if (edge_info) | |
819 | { | |
9771b263 | 820 | edge_info->cond_equivalences.release (); |
efea75f9 | 821 | free (edge_info); |
8702a557 | 822 | e->aux = NULL; |
efea75f9 JL |
823 | } |
824 | } | |
825 | } | |
826 | } | |
827 | ||
4d9192b5 TS |
828 | class dom_opt_dom_walker : public dom_walker |
829 | { | |
830 | public: | |
831 | dom_opt_dom_walker (cdi_direction direction) | |
65d3284b | 832 | : dom_walker (direction), m_dummy_cond (NULL) {} |
4d9192b5 TS |
833 | |
834 | virtual void before_dom_children (basic_block); | |
835 | virtual void after_dom_children (basic_block); | |
836 | ||
837 | private: | |
838 | void thread_across_edge (edge); | |
839 | ||
538dd0b7 | 840 | gcond *m_dummy_cond; |
4d9192b5 TS |
841 | }; |
842 | ||
b8698a0f | 843 | /* Jump threading, redundancy elimination and const/copy propagation. |
6de9cd9a | 844 | |
6de9cd9a DN |
845 | This pass may expose new symbols that need to be renamed into SSA. For |
846 | every new symbol exposed, its corresponding bit will be set in | |
ff2ad0f7 | 847 | VARS_TO_RENAME. */ |
6de9cd9a | 848 | |
be55bfe6 TS |
849 | namespace { |
850 | ||
851 | const pass_data pass_data_dominator = | |
852 | { | |
853 | GIMPLE_PASS, /* type */ | |
854 | "dom", /* name */ | |
855 | OPTGROUP_NONE, /* optinfo_flags */ | |
be55bfe6 TS |
856 | TV_TREE_SSA_DOMINATOR_OPTS, /* tv_id */ |
857 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
858 | 0, /* properties_provided */ | |
859 | 0, /* properties_destroyed */ | |
860 | 0, /* todo_flags_start */ | |
3bea341f | 861 | ( TODO_cleanup_cfg | TODO_update_ssa ), /* todo_flags_finish */ |
be55bfe6 TS |
862 | }; |
863 | ||
864 | class pass_dominator : public gimple_opt_pass | |
865 | { | |
866 | public: | |
867 | pass_dominator (gcc::context *ctxt) | |
868 | : gimple_opt_pass (pass_data_dominator, ctxt) | |
869 | {} | |
870 | ||
871 | /* opt_pass methods: */ | |
872 | opt_pass * clone () { return new pass_dominator (m_ctxt); } | |
873 | virtual bool gate (function *) { return flag_tree_dom != 0; } | |
874 | virtual unsigned int execute (function *); | |
875 | ||
876 | }; // class pass_dominator | |
877 | ||
878 | unsigned int | |
879 | pass_dominator::execute (function *fun) | |
6de9cd9a | 880 | { |
fded8de7 DN |
881 | memset (&opt_stats, 0, sizeof (opt_stats)); |
882 | ||
6de9cd9a | 883 | /* Create our hash tables. */ |
c203e8a7 | 884 | avail_exprs = new hash_table<expr_elt_hasher> (1024); |
9771b263 DN |
885 | avail_exprs_stack.create (20); |
886 | const_and_copies_stack.create (20); | |
8bdbfff5 | 887 | need_eh_cleanup = BITMAP_ALLOC (NULL); |
6de9cd9a | 888 | |
6de9cd9a | 889 | calculate_dominance_info (CDI_DOMINATORS); |
8d9d6561 | 890 | cfg_altered = false; |
6de9cd9a | 891 | |
b02b9b53 ZD |
892 | /* We need to know loop structures in order to avoid destroying them |
893 | in jump threading. Note that we still can e.g. thread through loop | |
894 | headers to an exit edge, or through loop header to the loop body, assuming | |
a3afdbb8 BC |
895 | that we update the loop info. |
896 | ||
897 | TODO: We don't need to set LOOPS_HAVE_PREHEADERS generally, but due | |
898 | to several overly conservative bail-outs in jump threading, case | |
899 | gcc.dg/tree-ssa/pr21417.c can't be threaded if loop preheader is | |
900 | missing. We should improve jump threading in future then | |
901 | LOOPS_HAVE_PREHEADERS won't be needed here. */ | |
902 | loop_optimizer_init (LOOPS_HAVE_PREHEADERS | LOOPS_HAVE_SIMPLE_LATCHES); | |
d38ffc55 | 903 | |
448ee662 RG |
904 | /* Initialize the value-handle array. */ |
905 | threadedge_initialize_values (); | |
906 | ||
2090d6a0 | 907 | /* We need accurate information regarding back edges in the CFG |
fa10beec | 908 | for jump threading; this may include back edges that are not part of |
b02b9b53 | 909 | a single loop. */ |
2090d6a0 | 910 | mark_dfs_back_edges (); |
b8698a0f | 911 | |
2090d6a0 | 912 | /* Recursively walk the dominator tree optimizing statements. */ |
be55bfe6 | 913 | dom_opt_dom_walker (CDI_DOMINATORS).walk (fun->cfg->x_entry_block_ptr); |
6de9cd9a | 914 | |
2090d6a0 | 915 | { |
726a989a | 916 | gimple_stmt_iterator gsi; |
2090d6a0 | 917 | basic_block bb; |
be55bfe6 | 918 | FOR_EACH_BB_FN (bb, fun) |
a881aaa7 RG |
919 | { |
920 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
726a989a | 921 | update_stmt_if_modified (gsi_stmt (gsi)); |
f430bae8 | 922 | } |
2090d6a0 | 923 | } |
a3b609df | 924 | |
2090d6a0 JL |
925 | /* If we exposed any new variables, go ahead and put them into |
926 | SSA form now, before we handle jump threading. This simplifies | |
927 | interactions between rewriting of _DECL nodes into SSA form | |
928 | and rewriting SSA_NAME nodes into SSA form after block | |
929 | duplication and CFG manipulation. */ | |
930 | update_ssa (TODO_update_ssa); | |
d38ffc55 | 931 | |
2090d6a0 | 932 | free_all_edge_infos (); |
d38ffc55 | 933 | |
2090d6a0 | 934 | /* Thread jumps, creating duplicate blocks as needed. */ |
b02b9b53 | 935 | cfg_altered |= thread_through_all_blocks (first_pass_instance); |
6de9cd9a | 936 | |
8d9d6561 EB |
937 | if (cfg_altered) |
938 | free_dominance_info (CDI_DOMINATORS); | |
939 | ||
2090d6a0 JL |
940 | /* Removal of statements may make some EH edges dead. Purge |
941 | such edges from the CFG as needed. */ | |
942 | if (!bitmap_empty_p (need_eh_cleanup)) | |
943 | { | |
45a7844f EB |
944 | unsigned i; |
945 | bitmap_iterator bi; | |
946 | ||
947 | /* Jump threading may have created forwarder blocks from blocks | |
948 | needing EH cleanup; the new successor of these blocks, which | |
1ce296cf JJ |
949 | has inherited from the original block, needs the cleanup. |
950 | Don't clear bits in the bitmap, as that can break the bitmap | |
951 | iterator. */ | |
45a7844f EB |
952 | EXECUTE_IF_SET_IN_BITMAP (need_eh_cleanup, 0, i, bi) |
953 | { | |
be55bfe6 | 954 | basic_block bb = BASIC_BLOCK_FOR_FN (fun, i); |
1ce296cf JJ |
955 | if (bb == NULL) |
956 | continue; | |
957 | while (single_succ_p (bb) | |
958 | && (single_succ_edge (bb)->flags & EDGE_EH) == 0) | |
959 | bb = single_succ (bb); | |
be55bfe6 | 960 | if (bb == EXIT_BLOCK_PTR_FOR_FN (fun)) |
1ce296cf JJ |
961 | continue; |
962 | if ((unsigned) bb->index != i) | |
963 | bitmap_set_bit (need_eh_cleanup, bb->index); | |
45a7844f EB |
964 | } |
965 | ||
726a989a | 966 | gimple_purge_all_dead_eh_edges (need_eh_cleanup); |
f61e445a | 967 | bitmap_clear (need_eh_cleanup); |
2090d6a0 | 968 | } |
6de9cd9a | 969 | |
be55bfe6 | 970 | statistics_counter_event (fun, "Redundant expressions eliminated", |
01902653 | 971 | opt_stats.num_re); |
be55bfe6 | 972 | statistics_counter_event (fun, "Constants propagated", |
01902653 | 973 | opt_stats.num_const_prop); |
be55bfe6 | 974 | statistics_counter_event (fun, "Copies propagated", |
01902653 RG |
975 | opt_stats.num_copy_prop); |
976 | ||
6de9cd9a DN |
977 | /* Debugging dumps. */ |
978 | if (dump_file && (dump_flags & TDF_STATS)) | |
979 | dump_dominator_optimization_stats (dump_file); | |
980 | ||
b02b9b53 ZD |
981 | loop_optimizer_finalize (); |
982 | ||
2090d6a0 | 983 | /* Delete our main hashtable. */ |
c203e8a7 TS |
984 | delete avail_exprs; |
985 | avail_exprs = NULL; | |
6de9cd9a | 986 | |
b16caf72 | 987 | /* Free asserted bitmaps and stacks. */ |
8bdbfff5 | 988 | BITMAP_FREE (need_eh_cleanup); |
b8698a0f | 989 | |
9771b263 DN |
990 | avail_exprs_stack.release (); |
991 | const_and_copies_stack.release (); | |
b8698a0f | 992 | |
448ee662 RG |
993 | /* Free the value-handle array. */ |
994 | threadedge_finalize_values (); | |
448ee662 | 995 | |
c2924966 | 996 | return 0; |
6de9cd9a DN |
997 | } |
998 | ||
27a4cd48 DM |
999 | } // anon namespace |
1000 | ||
1001 | gimple_opt_pass * | |
1002 | make_pass_dominator (gcc::context *ctxt) | |
1003 | { | |
1004 | return new pass_dominator (ctxt); | |
1005 | } | |
1006 | ||
6de9cd9a | 1007 | |
726a989a RB |
1008 | /* Given a conditional statement CONDSTMT, convert the |
1009 | condition to a canonical form. */ | |
0e0ed594 JL |
1010 | |
1011 | static void | |
538dd0b7 | 1012 | canonicalize_comparison (gcond *condstmt) |
0e0ed594 | 1013 | { |
0e0ed594 JL |
1014 | tree op0; |
1015 | tree op1; | |
726a989a | 1016 | enum tree_code code; |
0e0ed594 | 1017 | |
726a989a | 1018 | gcc_assert (gimple_code (condstmt) == GIMPLE_COND); |
0e0ed594 | 1019 | |
726a989a RB |
1020 | op0 = gimple_cond_lhs (condstmt); |
1021 | op1 = gimple_cond_rhs (condstmt); | |
1022 | ||
1023 | code = gimple_cond_code (condstmt); | |
0e0ed594 JL |
1024 | |
1025 | /* If it would be profitable to swap the operands, then do so to | |
1026 | canonicalize the statement, enabling better optimization. | |
1027 | ||
1028 | By placing canonicalization of such expressions here we | |
1029 | transparently keep statements in canonical form, even | |
1030 | when the statement is modified. */ | |
1031 | if (tree_swap_operands_p (op0, op1, false)) | |
1032 | { | |
1033 | /* For relationals we need to swap the operands | |
1034 | and change the code. */ | |
1035 | if (code == LT_EXPR | |
1036 | || code == GT_EXPR | |
1037 | || code == LE_EXPR | |
1038 | || code == GE_EXPR) | |
1039 | { | |
726a989a RB |
1040 | code = swap_tree_comparison (code); |
1041 | ||
1042 | gimple_cond_set_code (condstmt, code); | |
1043 | gimple_cond_set_lhs (condstmt, op1); | |
1044 | gimple_cond_set_rhs (condstmt, op0); | |
1045 | ||
1046 | update_stmt (condstmt); | |
0e0ed594 JL |
1047 | } |
1048 | } | |
1049 | } | |
6de9cd9a | 1050 | |
6de9cd9a DN |
1051 | /* Initialize local stacks for this optimizer and record equivalences |
1052 | upon entry to BB. Equivalences can come from the edge traversed to | |
1053 | reach BB or they may come from PHI nodes at the start of BB. */ | |
1054 | ||
6de9cd9a DN |
1055 | /* Remove all the expressions in LOCALS from TABLE, stopping when there are |
1056 | LIMIT entries left in LOCALs. */ | |
1057 | ||
1058 | static void | |
48732f23 | 1059 | remove_local_expressions_from_table (void) |
6de9cd9a | 1060 | { |
6de9cd9a | 1061 | /* Remove all the expressions made available in this block. */ |
9771b263 | 1062 | while (avail_exprs_stack.length () > 0) |
6de9cd9a | 1063 | { |
b00734df RB |
1064 | std::pair<expr_hash_elt_t, expr_hash_elt_t> victim |
1065 | = avail_exprs_stack.pop (); | |
4a8fb1a1 | 1066 | expr_hash_elt **slot; |
48732f23 | 1067 | |
b00734df | 1068 | if (victim.first == NULL) |
48732f23 | 1069 | break; |
6de9cd9a | 1070 | |
726a989a RB |
1071 | /* This must precede the actual removal from the hash table, |
1072 | as ELEMENT and the table entry may share a call argument | |
1073 | vector which will be freed during removal. */ | |
1074 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1075 | { | |
1076 | fprintf (dump_file, "<<<< "); | |
b00734df | 1077 | print_expr_hash_elt (dump_file, victim.first); |
726a989a RB |
1078 | } |
1079 | ||
b00734df RB |
1080 | slot = avail_exprs->find_slot (victim.first, NO_INSERT); |
1081 | gcc_assert (slot && *slot == victim.first); | |
1082 | if (victim.second != NULL) | |
1083 | { | |
1084 | free_expr_hash_elt (*slot); | |
1085 | *slot = victim.second; | |
1086 | } | |
1087 | else | |
1088 | avail_exprs->clear_slot (slot); | |
6de9cd9a DN |
1089 | } |
1090 | } | |
1091 | ||
b5fefcf6 JL |
1092 | /* Use the source/dest pairs in CONST_AND_COPIES_STACK to restore |
1093 | CONST_AND_COPIES to its original state, stopping when we hit a | |
1094 | NULL marker. */ | |
6de9cd9a DN |
1095 | |
1096 | static void | |
b5fefcf6 | 1097 | restore_vars_to_original_value (void) |
6de9cd9a | 1098 | { |
9771b263 | 1099 | while (const_and_copies_stack.length () > 0) |
6de9cd9a DN |
1100 | { |
1101 | tree prev_value, dest; | |
1102 | ||
9771b263 | 1103 | dest = const_and_copies_stack.pop (); |
6de9cd9a | 1104 | |
b5fefcf6 JL |
1105 | if (dest == NULL) |
1106 | break; | |
1107 | ||
726a989a RB |
1108 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1109 | { | |
1110 | fprintf (dump_file, "<<<< COPY "); | |
1111 | print_generic_expr (dump_file, dest, 0); | |
1112 | fprintf (dump_file, " = "); | |
1113 | print_generic_expr (dump_file, SSA_NAME_VALUE (dest), 0); | |
1114 | fprintf (dump_file, "\n"); | |
1115 | } | |
1116 | ||
9771b263 | 1117 | prev_value = const_and_copies_stack.pop (); |
448ee662 | 1118 | set_ssa_name_value (dest, prev_value); |
6de9cd9a DN |
1119 | } |
1120 | } | |
1121 | ||
2090d6a0 JL |
1122 | /* A trivial wrapper so that we can present the generic jump |
1123 | threading code with a simple API for simplifying statements. */ | |
1124 | static tree | |
726a989a RB |
1125 | simplify_stmt_for_jump_threading (gimple stmt, |
1126 | gimple within_stmt ATTRIBUTE_UNUSED) | |
2090d6a0 JL |
1127 | { |
1128 | return lookup_avail_expr (stmt, false); | |
1129 | } | |
1130 | ||
925f3871 JL |
1131 | /* Record into the equivalence tables any equivalences implied by |
1132 | traversing edge E (which are cached in E->aux). | |
1133 | ||
1134 | Callers are responsible for managing the unwinding markers. */ | |
83ae86f5 JL |
1135 | static void |
1136 | record_temporary_equivalences (edge e) | |
1137 | { | |
1138 | int i; | |
1139 | struct edge_info *edge_info = (struct edge_info *) e->aux; | |
1140 | ||
1141 | /* If we have info associated with this edge, record it into | |
1142 | our equivalence tables. */ | |
1143 | if (edge_info) | |
1144 | { | |
1145 | cond_equivalence *eq; | |
1146 | tree lhs = edge_info->lhs; | |
1147 | tree rhs = edge_info->rhs; | |
1148 | ||
1149 | /* If we have a simple NAME = VALUE equivalence, record it. */ | |
1150 | if (lhs && TREE_CODE (lhs) == SSA_NAME) | |
1151 | record_const_or_copy (lhs, rhs); | |
1152 | ||
1153 | /* If we have 0 = COND or 1 = COND equivalences, record them | |
1154 | into our expression hash tables. */ | |
1155 | for (i = 0; edge_info->cond_equivalences.iterate (i, &eq); ++i) | |
1156 | record_cond (eq); | |
1157 | } | |
1158 | } | |
1159 | ||
2090d6a0 JL |
1160 | /* Wrapper for common code to attempt to thread an edge. For example, |
1161 | it handles lazily building the dummy condition and the bookkeeping | |
1162 | when jump threading is successful. */ | |
1163 | ||
4d9192b5 TS |
1164 | void |
1165 | dom_opt_dom_walker::thread_across_edge (edge e) | |
2090d6a0 | 1166 | { |
65d3284b RS |
1167 | if (! m_dummy_cond) |
1168 | m_dummy_cond = | |
726a989a RB |
1169 | gimple_build_cond (NE_EXPR, |
1170 | integer_zero_node, integer_zero_node, | |
1171 | NULL, NULL); | |
2090d6a0 | 1172 | |
83ae86f5 JL |
1173 | /* Push a marker on both stacks so we can unwind the tables back to their |
1174 | current state. */ | |
b00734df RB |
1175 | avail_exprs_stack.safe_push |
1176 | (std::pair<expr_hash_elt_t, expr_hash_elt_t> (NULL, NULL)); | |
83ae86f5 JL |
1177 | const_and_copies_stack.safe_push (NULL_TREE); |
1178 | ||
1179 | /* Traversing E may result in equivalences we can utilize. */ | |
1180 | record_temporary_equivalences (e); | |
1181 | ||
1182 | /* With all the edge equivalences in the tables, go ahead and attempt | |
1183 | to thread through E->dest. */ | |
65d3284b | 1184 | ::thread_across_edge (m_dummy_cond, e, false, |
4d9192b5 TS |
1185 | &const_and_copies_stack, |
1186 | simplify_stmt_for_jump_threading); | |
83ae86f5 JL |
1187 | |
1188 | /* And restore the various tables to their state before | |
1189 | we threaded this edge. | |
1190 | ||
1191 | XXX The code in tree-ssa-threadedge.c will restore the state of | |
1192 | the const_and_copies table. We we just have to restore the expression | |
1193 | table. */ | |
1194 | remove_local_expressions_from_table (); | |
2090d6a0 JL |
1195 | } |
1196 | ||
6de9cd9a DN |
1197 | /* PHI nodes can create equivalences too. |
1198 | ||
1199 | Ignoring any alternatives which are the same as the result, if | |
1200 | all the alternatives are equal, then the PHI node creates an | |
b16caf72 | 1201 | equivalence. */ |
dd747311 | 1202 | |
6de9cd9a | 1203 | static void |
efea75f9 | 1204 | record_equivalences_from_phis (basic_block bb) |
6de9cd9a | 1205 | { |
538dd0b7 | 1206 | gphi_iterator gsi; |
b8698a0f | 1207 | |
726a989a | 1208 | for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
6de9cd9a | 1209 | { |
538dd0b7 | 1210 | gphi *phi = gsi.phi (); |
726a989a RB |
1211 | |
1212 | tree lhs = gimple_phi_result (phi); | |
6de9cd9a | 1213 | tree rhs = NULL; |
726a989a | 1214 | size_t i; |
6de9cd9a | 1215 | |
726a989a | 1216 | for (i = 0; i < gimple_phi_num_args (phi); i++) |
6de9cd9a | 1217 | { |
726a989a | 1218 | tree t = gimple_phi_arg_def (phi, i); |
6de9cd9a | 1219 | |
6e38fea3 KH |
1220 | /* Ignore alternatives which are the same as our LHS. Since |
1221 | LHS is a PHI_RESULT, it is known to be a SSA_NAME, so we | |
1222 | can simply compare pointers. */ | |
073b8140 | 1223 | if (lhs == t) |
a18428f3 KH |
1224 | continue; |
1225 | ||
1226 | /* If we have not processed an alternative yet, then set | |
1227 | RHS to this alternative. */ | |
1228 | if (rhs == NULL) | |
1229 | rhs = t; | |
1230 | /* If we have processed an alternative (stored in RHS), then | |
1231 | see if it is equal to this one. If it isn't, then stop | |
1232 | the search. */ | |
1233 | else if (! operand_equal_for_phi_arg_p (rhs, t)) | |
6de9cd9a DN |
1234 | break; |
1235 | } | |
1236 | ||
1237 | /* If we had no interesting alternatives, then all the RHS alternatives | |
1238 | must have been the same as LHS. */ | |
1239 | if (!rhs) | |
1240 | rhs = lhs; | |
1241 | ||
1242 | /* If we managed to iterate through each PHI alternative without | |
1243 | breaking out of the loop, then we have a PHI which may create | |
1244 | a useful equivalence. We do not need to record unwind data for | |
1245 | this, since this is a true assignment and not an equivalence | |
1ea7e6ad | 1246 | inferred from a comparison. All uses of this ssa name are dominated |
6de9cd9a | 1247 | by this assignment, so unwinding just costs time and space. */ |
73c7d6bc | 1248 | if (i == gimple_phi_num_args (phi) |
a59d8e8e | 1249 | && may_propagate_copy (lhs, rhs)) |
448ee662 | 1250 | set_ssa_name_value (lhs, rhs); |
6de9cd9a DN |
1251 | } |
1252 | } | |
1253 | ||
28c008bb JL |
1254 | /* Ignoring loop backedges, if BB has precisely one incoming edge then |
1255 | return that edge. Otherwise return NULL. */ | |
1256 | static edge | |
1257 | single_incoming_edge_ignoring_loop_edges (basic_block bb) | |
1258 | { | |
1259 | edge retval = NULL; | |
1260 | edge e; | |
628f6a4e | 1261 | edge_iterator ei; |
28c008bb | 1262 | |
628f6a4e | 1263 | FOR_EACH_EDGE (e, ei, bb->preds) |
28c008bb JL |
1264 | { |
1265 | /* A loop back edge can be identified by the destination of | |
1266 | the edge dominating the source of the edge. */ | |
1267 | if (dominated_by_p (CDI_DOMINATORS, e->src, e->dest)) | |
1268 | continue; | |
1269 | ||
1270 | /* If we have already seen a non-loop edge, then we must have | |
1271 | multiple incoming non-loop edges and thus we return NULL. */ | |
1272 | if (retval) | |
1273 | return NULL; | |
1274 | ||
1275 | /* This is the first non-loop incoming edge we have found. Record | |
1276 | it. */ | |
1277 | retval = e; | |
1278 | } | |
1279 | ||
1280 | return retval; | |
1281 | } | |
1282 | ||
6de9cd9a DN |
1283 | /* Record any equivalences created by the incoming edge to BB. If BB |
1284 | has more than one incoming edge, then no equivalence is created. */ | |
1285 | ||
1286 | static void | |
efea75f9 | 1287 | record_equivalences_from_incoming_edge (basic_block bb) |
6de9cd9a | 1288 | { |
efea75f9 | 1289 | edge e; |
6de9cd9a | 1290 | basic_block parent; |
efea75f9 | 1291 | struct edge_info *edge_info; |
6de9cd9a | 1292 | |
35fd3193 | 1293 | /* If our parent block ended with a control statement, then we may be |
6de9cd9a DN |
1294 | able to record some equivalences based on which outgoing edge from |
1295 | the parent was followed. */ | |
1296 | parent = get_immediate_dominator (CDI_DOMINATORS, bb); | |
6de9cd9a | 1297 | |
efea75f9 | 1298 | e = single_incoming_edge_ignoring_loop_edges (bb); |
6de9cd9a | 1299 | |
efea75f9 JL |
1300 | /* If we had a single incoming edge from our parent block, then enter |
1301 | any data associated with the edge into our tables. */ | |
1302 | if (e && e->src == parent) | |
6de9cd9a | 1303 | { |
efea75f9 | 1304 | unsigned int i; |
6de9cd9a | 1305 | |
e1111e8e | 1306 | edge_info = (struct edge_info *) e->aux; |
6de9cd9a | 1307 | |
efea75f9 | 1308 | if (edge_info) |
6de9cd9a | 1309 | { |
efea75f9 JL |
1310 | tree lhs = edge_info->lhs; |
1311 | tree rhs = edge_info->rhs; | |
fd4a760e | 1312 | cond_equivalence *eq; |
efea75f9 JL |
1313 | |
1314 | if (lhs) | |
1315 | record_equality (lhs, rhs); | |
1316 | ||
39e45653 JL |
1317 | /* If LHS is an SSA_NAME and RHS is a constant integer and LHS was |
1318 | set via a widening type conversion, then we may be able to record | |
4f1f78b9 JL |
1319 | additional equivalences. */ |
1320 | if (lhs | |
1321 | && TREE_CODE (lhs) == SSA_NAME | |
39e45653 JL |
1322 | && is_gimple_constant (rhs) |
1323 | && TREE_CODE (rhs) == INTEGER_CST) | |
4f1f78b9 JL |
1324 | { |
1325 | gimple defstmt = SSA_NAME_DEF_STMT (lhs); | |
1326 | ||
1327 | if (defstmt | |
1328 | && is_gimple_assign (defstmt) | |
1329 | && CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (defstmt))) | |
1330 | { | |
1331 | tree old_rhs = gimple_assign_rhs1 (defstmt); | |
39e45653 | 1332 | |
be672e08 JL |
1333 | /* If the conversion widens the original value and |
1334 | the constant is in the range of the type of OLD_RHS, | |
8d34e421 | 1335 | then convert the constant and record the equivalence. |
be672e08 JL |
1336 | |
1337 | Note that int_fits_type_p does not check the precision | |
1338 | if the upper and lower bounds are OK. */ | |
dd884525 | 1339 | if (INTEGRAL_TYPE_P (TREE_TYPE (old_rhs)) |
be672e08 JL |
1340 | && (TYPE_PRECISION (TREE_TYPE (lhs)) |
1341 | > TYPE_PRECISION (TREE_TYPE (old_rhs))) | |
dd884525 | 1342 | && int_fits_type_p (rhs, TREE_TYPE (old_rhs))) |
39e45653 JL |
1343 | { |
1344 | tree newval = fold_convert (TREE_TYPE (old_rhs), rhs); | |
1345 | record_equality (old_rhs, newval); | |
1346 | } | |
4f1f78b9 JL |
1347 | } |
1348 | } | |
1349 | ||
9771b263 | 1350 | for (i = 0; edge_info->cond_equivalences.iterate (i, &eq); ++i) |
fd4a760e | 1351 | record_cond (eq); |
6de9cd9a DN |
1352 | } |
1353 | } | |
6de9cd9a DN |
1354 | } |
1355 | ||
1356 | /* Dump SSA statistics on FILE. */ | |
1357 | ||
1358 | void | |
1359 | dump_dominator_optimization_stats (FILE *file) | |
1360 | { | |
6de9cd9a DN |
1361 | fprintf (file, "Total number of statements: %6ld\n\n", |
1362 | opt_stats.num_stmts); | |
1363 | fprintf (file, "Exprs considered for dominator optimizations: %6ld\n", | |
1364 | opt_stats.num_exprs_considered); | |
1365 | ||
6de9cd9a DN |
1366 | fprintf (file, "\nHash table statistics:\n"); |
1367 | ||
1368 | fprintf (file, " avail_exprs: "); | |
c203e8a7 | 1369 | htab_statistics (file, *avail_exprs); |
6de9cd9a DN |
1370 | } |
1371 | ||
1372 | ||
1373 | /* Dump SSA statistics on stderr. */ | |
1374 | ||
24e47c76 | 1375 | DEBUG_FUNCTION void |
6de9cd9a DN |
1376 | debug_dominator_optimization_stats (void) |
1377 | { | |
1378 | dump_dominator_optimization_stats (stderr); | |
1379 | } | |
1380 | ||
1381 | ||
1382 | /* Dump statistics for the hash table HTAB. */ | |
1383 | ||
1384 | static void | |
c203e8a7 | 1385 | htab_statistics (FILE *file, const hash_table<expr_elt_hasher> &htab) |
6de9cd9a DN |
1386 | { |
1387 | fprintf (file, "size %ld, %ld elements, %f collision/search ratio\n", | |
4a8fb1a1 LC |
1388 | (long) htab.size (), |
1389 | (long) htab.elements (), | |
1390 | htab.collisions ()); | |
6de9cd9a DN |
1391 | } |
1392 | ||
726a989a RB |
1393 | |
1394 | /* Enter condition equivalence into the expression hash table. | |
1395 | This indicates that a conditional expression has a known | |
1396 | boolean value. */ | |
6de9cd9a DN |
1397 | |
1398 | static void | |
fd4a760e | 1399 | record_cond (cond_equivalence *p) |
6de9cd9a | 1400 | { |
e1111e8e | 1401 | struct expr_hash_elt *element = XCNEW (struct expr_hash_elt); |
4a8fb1a1 | 1402 | expr_hash_elt **slot; |
6de9cd9a | 1403 | |
726a989a | 1404 | initialize_hash_element_from_expr (&p->cond, p->value, element); |
6de9cd9a | 1405 | |
c203e8a7 | 1406 | slot = avail_exprs->find_slot_with_hash (element, element->hash, INSERT); |
6de9cd9a DN |
1407 | if (*slot == NULL) |
1408 | { | |
4a8fb1a1 | 1409 | *slot = element; |
726a989a RB |
1410 | |
1411 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1412 | { | |
1413 | fprintf (dump_file, "1>>> "); | |
1414 | print_expr_hash_elt (dump_file, element); | |
1415 | } | |
1416 | ||
b00734df RB |
1417 | avail_exprs_stack.safe_push |
1418 | (std::pair<expr_hash_elt_t, expr_hash_elt_t> (element, NULL)); | |
6de9cd9a DN |
1419 | } |
1420 | else | |
b6db991c | 1421 | free_expr_hash_elt (element); |
6de9cd9a DN |
1422 | } |
1423 | ||
726a989a | 1424 | /* Build a cond_equivalence record indicating that the comparison |
fd4a760e | 1425 | CODE holds between operands OP0 and OP1 and push it to **P. */ |
b8698a0f | 1426 | |
efea75f9 | 1427 | static void |
726a989a RB |
1428 | build_and_record_new_cond (enum tree_code code, |
1429 | tree op0, tree op1, | |
9771b263 | 1430 | vec<cond_equivalence> *p) |
efea75f9 | 1431 | { |
fd4a760e RG |
1432 | cond_equivalence c; |
1433 | struct hashable_expr *cond = &c.cond; | |
726a989a RB |
1434 | |
1435 | gcc_assert (TREE_CODE_CLASS (code) == tcc_comparison); | |
1436 | ||
1437 | cond->type = boolean_type_node; | |
1438 | cond->kind = EXPR_BINARY; | |
1439 | cond->ops.binary.op = code; | |
1440 | cond->ops.binary.opnd0 = op0; | |
1441 | cond->ops.binary.opnd1 = op1; | |
1442 | ||
fd4a760e | 1443 | c.value = boolean_true_node; |
9771b263 | 1444 | p->safe_push (c); |
efea75f9 JL |
1445 | } |
1446 | ||
1447 | /* Record that COND is true and INVERTED is false into the edge information | |
1448 | structure. Also record that any conditions dominated by COND are true | |
1449 | as well. | |
d2d8936f JL |
1450 | |
1451 | For example, if a < b is true, then a <= b must also be true. */ | |
1452 | ||
1453 | static void | |
efea75f9 | 1454 | record_conditions (struct edge_info *edge_info, tree cond, tree inverted) |
d2d8936f | 1455 | { |
efea75f9 | 1456 | tree op0, op1; |
fd4a760e | 1457 | cond_equivalence c; |
efea75f9 JL |
1458 | |
1459 | if (!COMPARISON_CLASS_P (cond)) | |
1460 | return; | |
1461 | ||
1462 | op0 = TREE_OPERAND (cond, 0); | |
1463 | op1 = TREE_OPERAND (cond, 1); | |
1464 | ||
d2d8936f JL |
1465 | switch (TREE_CODE (cond)) |
1466 | { | |
1467 | case LT_EXPR: | |
d2d8936f | 1468 | case GT_EXPR: |
14b41b5f RS |
1469 | if (FLOAT_TYPE_P (TREE_TYPE (op0))) |
1470 | { | |
14b41b5f | 1471 | build_and_record_new_cond (ORDERED_EXPR, op0, op1, |
fd4a760e | 1472 | &edge_info->cond_equivalences); |
14b41b5f | 1473 | build_and_record_new_cond (LTGT_EXPR, op0, op1, |
fd4a760e | 1474 | &edge_info->cond_equivalences); |
14b41b5f RS |
1475 | } |
1476 | ||
efea75f9 JL |
1477 | build_and_record_new_cond ((TREE_CODE (cond) == LT_EXPR |
1478 | ? LE_EXPR : GE_EXPR), | |
fd4a760e | 1479 | op0, op1, &edge_info->cond_equivalences); |
efea75f9 | 1480 | build_and_record_new_cond (NE_EXPR, op0, op1, |
fd4a760e | 1481 | &edge_info->cond_equivalences); |
d2d8936f JL |
1482 | break; |
1483 | ||
1484 | case GE_EXPR: | |
1485 | case LE_EXPR: | |
14b41b5f RS |
1486 | if (FLOAT_TYPE_P (TREE_TYPE (op0))) |
1487 | { | |
14b41b5f | 1488 | build_and_record_new_cond (ORDERED_EXPR, op0, op1, |
fd4a760e | 1489 | &edge_info->cond_equivalences); |
14b41b5f | 1490 | } |
d2d8936f JL |
1491 | break; |
1492 | ||
1493 | case EQ_EXPR: | |
14b41b5f RS |
1494 | if (FLOAT_TYPE_P (TREE_TYPE (op0))) |
1495 | { | |
14b41b5f | 1496 | build_and_record_new_cond (ORDERED_EXPR, op0, op1, |
fd4a760e | 1497 | &edge_info->cond_equivalences); |
14b41b5f | 1498 | } |
efea75f9 | 1499 | build_and_record_new_cond (LE_EXPR, op0, op1, |
fd4a760e | 1500 | &edge_info->cond_equivalences); |
efea75f9 | 1501 | build_and_record_new_cond (GE_EXPR, op0, op1, |
fd4a760e | 1502 | &edge_info->cond_equivalences); |
d2d8936f JL |
1503 | break; |
1504 | ||
1505 | case UNORDERED_EXPR: | |
efea75f9 | 1506 | build_and_record_new_cond (NE_EXPR, op0, op1, |
fd4a760e | 1507 | &edge_info->cond_equivalences); |
efea75f9 | 1508 | build_and_record_new_cond (UNLE_EXPR, op0, op1, |
fd4a760e | 1509 | &edge_info->cond_equivalences); |
efea75f9 | 1510 | build_and_record_new_cond (UNGE_EXPR, op0, op1, |
fd4a760e | 1511 | &edge_info->cond_equivalences); |
efea75f9 | 1512 | build_and_record_new_cond (UNEQ_EXPR, op0, op1, |
fd4a760e | 1513 | &edge_info->cond_equivalences); |
efea75f9 | 1514 | build_and_record_new_cond (UNLT_EXPR, op0, op1, |
fd4a760e | 1515 | &edge_info->cond_equivalences); |
efea75f9 | 1516 | build_and_record_new_cond (UNGT_EXPR, op0, op1, |
fd4a760e | 1517 | &edge_info->cond_equivalences); |
d2d8936f JL |
1518 | break; |
1519 | ||
1520 | case UNLT_EXPR: | |
d2d8936f | 1521 | case UNGT_EXPR: |
efea75f9 JL |
1522 | build_and_record_new_cond ((TREE_CODE (cond) == UNLT_EXPR |
1523 | ? UNLE_EXPR : UNGE_EXPR), | |
fd4a760e | 1524 | op0, op1, &edge_info->cond_equivalences); |
efea75f9 | 1525 | build_and_record_new_cond (NE_EXPR, op0, op1, |
fd4a760e | 1526 | &edge_info->cond_equivalences); |
d2d8936f JL |
1527 | break; |
1528 | ||
1529 | case UNEQ_EXPR: | |
efea75f9 | 1530 | build_and_record_new_cond (UNLE_EXPR, op0, op1, |
fd4a760e | 1531 | &edge_info->cond_equivalences); |
efea75f9 | 1532 | build_and_record_new_cond (UNGE_EXPR, op0, op1, |
fd4a760e | 1533 | &edge_info->cond_equivalences); |
d2d8936f JL |
1534 | break; |
1535 | ||
1536 | case LTGT_EXPR: | |
efea75f9 | 1537 | build_and_record_new_cond (NE_EXPR, op0, op1, |
fd4a760e | 1538 | &edge_info->cond_equivalences); |
efea75f9 | 1539 | build_and_record_new_cond (ORDERED_EXPR, op0, op1, |
fd4a760e | 1540 | &edge_info->cond_equivalences); |
efea75f9 | 1541 | break; |
d2d8936f JL |
1542 | |
1543 | default: | |
1544 | break; | |
1545 | } | |
efea75f9 JL |
1546 | |
1547 | /* Now store the original true and false conditions into the first | |
1548 | two slots. */ | |
fd4a760e RG |
1549 | initialize_expr_from_cond (cond, &c.cond); |
1550 | c.value = boolean_true_node; | |
9771b263 | 1551 | edge_info->cond_equivalences.safe_push (c); |
726a989a RB |
1552 | |
1553 | /* It is possible for INVERTED to be the negation of a comparison, | |
1554 | and not a valid RHS or GIMPLE_COND condition. This happens because | |
1555 | invert_truthvalue may return such an expression when asked to invert | |
1556 | a floating-point comparison. These comparisons are not assumed to | |
1557 | obey the trichotomy law. */ | |
fd4a760e RG |
1558 | initialize_expr_from_cond (inverted, &c.cond); |
1559 | c.value = boolean_false_node; | |
9771b263 | 1560 | edge_info->cond_equivalences.safe_push (c); |
d2d8936f JL |
1561 | } |
1562 | ||
6de9cd9a DN |
1563 | /* A helper function for record_const_or_copy and record_equality. |
1564 | Do the work of recording the value and undo info. */ | |
1565 | ||
1566 | static void | |
b5fefcf6 | 1567 | record_const_or_copy_1 (tree x, tree y, tree prev_x) |
6de9cd9a | 1568 | { |
448ee662 | 1569 | set_ssa_name_value (x, y); |
6de9cd9a | 1570 | |
726a989a RB |
1571 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1572 | { | |
1573 | fprintf (dump_file, "0>>> COPY "); | |
1574 | print_generic_expr (dump_file, x, 0); | |
1575 | fprintf (dump_file, " = "); | |
1576 | print_generic_expr (dump_file, y, 0); | |
1577 | fprintf (dump_file, "\n"); | |
1578 | } | |
1579 | ||
9771b263 DN |
1580 | const_and_copies_stack.reserve (2); |
1581 | const_and_copies_stack.quick_push (prev_x); | |
1582 | const_and_copies_stack.quick_push (x); | |
6de9cd9a DN |
1583 | } |
1584 | ||
1585 | /* Record that X is equal to Y in const_and_copies. Record undo | |
ceb7eb8f | 1586 | information in the block-local vector. */ |
6de9cd9a DN |
1587 | |
1588 | static void | |
b5fefcf6 | 1589 | record_const_or_copy (tree x, tree y) |
6de9cd9a | 1590 | { |
3aecd08b | 1591 | tree prev_x = SSA_NAME_VALUE (x); |
6de9cd9a | 1592 | |
726a989a RB |
1593 | gcc_assert (TREE_CODE (x) == SSA_NAME); |
1594 | ||
6de9cd9a DN |
1595 | if (TREE_CODE (y) == SSA_NAME) |
1596 | { | |
3aecd08b | 1597 | tree tmp = SSA_NAME_VALUE (y); |
6de9cd9a DN |
1598 | if (tmp) |
1599 | y = tmp; | |
1600 | } | |
1601 | ||
b5fefcf6 | 1602 | record_const_or_copy_1 (x, y, prev_x); |
6de9cd9a DN |
1603 | } |
1604 | ||
406bfdd3 RB |
1605 | /* Return the loop depth of the basic block of the defining statement of X. |
1606 | This number should not be treated as absolutely correct because the loop | |
1607 | information may not be completely up-to-date when dom runs. However, it | |
1608 | will be relatively correct, and as more passes are taught to keep loop info | |
1609 | up to date, the result will become more and more accurate. */ | |
1610 | ||
1611 | static int | |
1612 | loop_depth_of_name (tree x) | |
1613 | { | |
1614 | gimple defstmt; | |
1615 | basic_block defbb; | |
1616 | ||
1617 | /* If it's not an SSA_NAME, we have no clue where the definition is. */ | |
1618 | if (TREE_CODE (x) != SSA_NAME) | |
1619 | return 0; | |
1620 | ||
1621 | /* Otherwise return the loop depth of the defining statement's bb. | |
1622 | Note that there may not actually be a bb for this statement, if the | |
1623 | ssa_name is live on entry. */ | |
1624 | defstmt = SSA_NAME_DEF_STMT (x); | |
1625 | defbb = gimple_bb (defstmt); | |
1626 | if (!defbb) | |
1627 | return 0; | |
1628 | ||
1629 | return bb_loop_depth (defbb); | |
1630 | } | |
1631 | ||
6de9cd9a DN |
1632 | /* Similarly, but assume that X and Y are the two operands of an EQ_EXPR. |
1633 | This constrains the cases in which we may treat this as assignment. */ | |
1634 | ||
1635 | static void | |
b5fefcf6 | 1636 | record_equality (tree x, tree y) |
6de9cd9a DN |
1637 | { |
1638 | tree prev_x = NULL, prev_y = NULL; | |
1639 | ||
1640 | if (TREE_CODE (x) == SSA_NAME) | |
3aecd08b | 1641 | prev_x = SSA_NAME_VALUE (x); |
6de9cd9a | 1642 | if (TREE_CODE (y) == SSA_NAME) |
3aecd08b | 1643 | prev_y = SSA_NAME_VALUE (y); |
6de9cd9a | 1644 | |
84dd478f DB |
1645 | /* If one of the previous values is invariant, or invariant in more loops |
1646 | (by depth), then use that. | |
6de9cd9a DN |
1647 | Otherwise it doesn't matter which value we choose, just so |
1648 | long as we canonicalize on one value. */ | |
ad6003f2 | 1649 | if (is_gimple_min_invariant (y)) |
6de9cd9a | 1650 | ; |
406bfdd3 RB |
1651 | else if (is_gimple_min_invariant (x) |
1652 | /* ??? When threading over backedges the following is important | |
1653 | for correctness. See PR61757. */ | |
1654 | || (loop_depth_of_name (x) <= loop_depth_of_name (y))) | |
6de9cd9a | 1655 | prev_x = x, x = y, y = prev_x, prev_x = prev_y; |
ad6003f2 | 1656 | else if (prev_x && is_gimple_min_invariant (prev_x)) |
6de9cd9a | 1657 | x = y, y = prev_x, prev_x = prev_y; |
c9145754 | 1658 | else if (prev_y) |
6de9cd9a DN |
1659 | y = prev_y; |
1660 | ||
1661 | /* After the swapping, we must have one SSA_NAME. */ | |
1662 | if (TREE_CODE (x) != SSA_NAME) | |
1663 | return; | |
1664 | ||
1665 | /* For IEEE, -0.0 == 0.0, so we don't necessarily know the sign of a | |
1666 | variable compared against zero. If we're honoring signed zeros, | |
1667 | then we cannot record this value unless we know that the value is | |
1ea7e6ad | 1668 | nonzero. */ |
3d3dbadd | 1669 | if (HONOR_SIGNED_ZEROS (x) |
6de9cd9a DN |
1670 | && (TREE_CODE (y) != REAL_CST |
1671 | || REAL_VALUES_EQUAL (dconst0, TREE_REAL_CST (y)))) | |
1672 | return; | |
1673 | ||
b5fefcf6 | 1674 | record_const_or_copy_1 (x, y, prev_x); |
6de9cd9a DN |
1675 | } |
1676 | ||
f67e783f ZD |
1677 | /* Returns true when STMT is a simple iv increment. It detects the |
1678 | following situation: | |
b8698a0f | 1679 | |
f67e783f ZD |
1680 | i_1 = phi (..., i_2) |
1681 | i_2 = i_1 +/- ... */ | |
1682 | ||
601f64e2 | 1683 | bool |
726a989a | 1684 | simple_iv_increment_p (gimple stmt) |
f67e783f | 1685 | { |
601f64e2 | 1686 | enum tree_code code; |
726a989a RB |
1687 | tree lhs, preinc; |
1688 | gimple phi; | |
1689 | size_t i; | |
f67e783f | 1690 | |
726a989a | 1691 | if (gimple_code (stmt) != GIMPLE_ASSIGN) |
f67e783f ZD |
1692 | return false; |
1693 | ||
726a989a | 1694 | lhs = gimple_assign_lhs (stmt); |
f67e783f ZD |
1695 | if (TREE_CODE (lhs) != SSA_NAME) |
1696 | return false; | |
1697 | ||
601f64e2 RG |
1698 | code = gimple_assign_rhs_code (stmt); |
1699 | if (code != PLUS_EXPR | |
1700 | && code != MINUS_EXPR | |
1701 | && code != POINTER_PLUS_EXPR) | |
f67e783f ZD |
1702 | return false; |
1703 | ||
726a989a | 1704 | preinc = gimple_assign_rhs1 (stmt); |
f67e783f ZD |
1705 | if (TREE_CODE (preinc) != SSA_NAME) |
1706 | return false; | |
1707 | ||
1708 | phi = SSA_NAME_DEF_STMT (preinc); | |
726a989a | 1709 | if (gimple_code (phi) != GIMPLE_PHI) |
f67e783f ZD |
1710 | return false; |
1711 | ||
726a989a RB |
1712 | for (i = 0; i < gimple_phi_num_args (phi); i++) |
1713 | if (gimple_phi_arg_def (phi, i) == lhs) | |
f67e783f ZD |
1714 | return true; |
1715 | ||
1716 | return false; | |
1717 | } | |
1718 | ||
ff2ad0f7 | 1719 | /* CONST_AND_COPIES is a table which maps an SSA_NAME to the current |
b8698a0f | 1720 | known value for that SSA_NAME (or NULL if no value is known). |
ff2ad0f7 | 1721 | |
b16caf72 JL |
1722 | Propagate values from CONST_AND_COPIES into the PHI nodes of the |
1723 | successors of BB. */ | |
ff2ad0f7 DN |
1724 | |
1725 | static void | |
b16caf72 | 1726 | cprop_into_successor_phis (basic_block bb) |
ff2ad0f7 DN |
1727 | { |
1728 | edge e; | |
628f6a4e | 1729 | edge_iterator ei; |
ff2ad0f7 | 1730 | |
628f6a4e | 1731 | FOR_EACH_EDGE (e, ei, bb->succs) |
ff2ad0f7 | 1732 | { |
0492baf2 | 1733 | int indx; |
538dd0b7 | 1734 | gphi_iterator gsi; |
ff2ad0f7 DN |
1735 | |
1736 | /* If this is an abnormal edge, then we do not want to copy propagate | |
1737 | into the PHI alternative associated with this edge. */ | |
1738 | if (e->flags & EDGE_ABNORMAL) | |
1739 | continue; | |
1740 | ||
726a989a RB |
1741 | gsi = gsi_start_phis (e->dest); |
1742 | if (gsi_end_p (gsi)) | |
ff2ad0f7 DN |
1743 | continue; |
1744 | ||
8d34e421 JL |
1745 | /* We may have an equivalence associated with this edge. While |
1746 | we can not propagate it into non-dominated blocks, we can | |
1747 | propagate them into PHIs in non-dominated blocks. */ | |
1748 | ||
1749 | /* Push the unwind marker so we can reset the const and copies | |
1750 | table back to its original state after processing this edge. */ | |
1751 | const_and_copies_stack.safe_push (NULL_TREE); | |
1752 | ||
1753 | /* Extract and record any simple NAME = VALUE equivalences. | |
1754 | ||
1755 | Don't bother with [01] = COND equivalences, they're not useful | |
1756 | here. */ | |
1757 | struct edge_info *edge_info = (struct edge_info *) e->aux; | |
1758 | if (edge_info) | |
1759 | { | |
1760 | tree lhs = edge_info->lhs; | |
1761 | tree rhs = edge_info->rhs; | |
1762 | ||
1763 | if (lhs && TREE_CODE (lhs) == SSA_NAME) | |
1764 | record_const_or_copy (lhs, rhs); | |
1765 | } | |
1766 | ||
0492baf2 | 1767 | indx = e->dest_idx; |
726a989a | 1768 | for ( ; !gsi_end_p (gsi); gsi_next (&gsi)) |
ff2ad0f7 | 1769 | { |
c22940cd | 1770 | tree new_val; |
ff2ad0f7 | 1771 | use_operand_p orig_p; |
c22940cd | 1772 | tree orig_val; |
538dd0b7 | 1773 | gphi *phi = gsi.phi (); |
ff2ad0f7 | 1774 | |
ff2ad0f7 DN |
1775 | /* The alternative may be associated with a constant, so verify |
1776 | it is an SSA_NAME before doing anything with it. */ | |
726a989a RB |
1777 | orig_p = gimple_phi_arg_imm_use_ptr (phi, indx); |
1778 | orig_val = get_use_from_ptr (orig_p); | |
c22940cd | 1779 | if (TREE_CODE (orig_val) != SSA_NAME) |
ff2ad0f7 DN |
1780 | continue; |
1781 | ||
ff2ad0f7 DN |
1782 | /* If we have *ORIG_P in our constant/copy table, then replace |
1783 | ORIG_P with its value in our constant/copy table. */ | |
c22940cd TN |
1784 | new_val = SSA_NAME_VALUE (orig_val); |
1785 | if (new_val | |
1786 | && new_val != orig_val | |
1787 | && (TREE_CODE (new_val) == SSA_NAME | |
1788 | || is_gimple_min_invariant (new_val)) | |
1789 | && may_propagate_copy (orig_val, new_val)) | |
1790 | propagate_value (orig_p, new_val); | |
ff2ad0f7 | 1791 | } |
8d34e421 JL |
1792 | |
1793 | restore_vars_to_original_value (); | |
ff2ad0f7 DN |
1794 | } |
1795 | } | |
1796 | ||
efea75f9 JL |
1797 | /* We have finished optimizing BB, record any information implied by |
1798 | taking a specific outgoing edge from BB. */ | |
1799 | ||
1800 | static void | |
1801 | record_edge_info (basic_block bb) | |
1802 | { | |
726a989a | 1803 | gimple_stmt_iterator gsi = gsi_last_bb (bb); |
efea75f9 JL |
1804 | struct edge_info *edge_info; |
1805 | ||
726a989a | 1806 | if (! gsi_end_p (gsi)) |
efea75f9 | 1807 | { |
726a989a | 1808 | gimple stmt = gsi_stmt (gsi); |
db3927fb | 1809 | location_t loc = gimple_location (stmt); |
efea75f9 | 1810 | |
726a989a | 1811 | if (gimple_code (stmt) == GIMPLE_SWITCH) |
efea75f9 | 1812 | { |
538dd0b7 DM |
1813 | gswitch *switch_stmt = as_a <gswitch *> (stmt); |
1814 | tree index = gimple_switch_index (switch_stmt); | |
efea75f9 | 1815 | |
726a989a | 1816 | if (TREE_CODE (index) == SSA_NAME) |
efea75f9 | 1817 | { |
726a989a | 1818 | int i; |
538dd0b7 | 1819 | int n_labels = gimple_switch_num_labels (switch_stmt); |
8b1c6fd7 | 1820 | tree *info = XCNEWVEC (tree, last_basic_block_for_fn (cfun)); |
efea75f9 JL |
1821 | edge e; |
1822 | edge_iterator ei; | |
1823 | ||
1824 | for (i = 0; i < n_labels; i++) | |
1825 | { | |
538dd0b7 | 1826 | tree label = gimple_switch_label (switch_stmt, i); |
efea75f9 | 1827 | basic_block target_bb = label_to_block (CASE_LABEL (label)); |
efea75f9 JL |
1828 | if (CASE_HIGH (label) |
1829 | || !CASE_LOW (label) | |
1830 | || info[target_bb->index]) | |
1831 | info[target_bb->index] = error_mark_node; | |
1832 | else | |
1833 | info[target_bb->index] = label; | |
1834 | } | |
1835 | ||
1836 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1837 | { | |
1838 | basic_block target_bb = e->dest; | |
726a989a | 1839 | tree label = info[target_bb->index]; |
ff2ad0f7 | 1840 | |
726a989a | 1841 | if (label != NULL && label != error_mark_node) |
efea75f9 | 1842 | { |
db3927fb AH |
1843 | tree x = fold_convert_loc (loc, TREE_TYPE (index), |
1844 | CASE_LOW (label)); | |
efea75f9 | 1845 | edge_info = allocate_edge_info (e); |
726a989a | 1846 | edge_info->lhs = index; |
efea75f9 JL |
1847 | edge_info->rhs = x; |
1848 | } | |
1849 | } | |
1850 | free (info); | |
1851 | } | |
1852 | } | |
1853 | ||
1854 | /* A COND_EXPR may create equivalences too. */ | |
726a989a | 1855 | if (gimple_code (stmt) == GIMPLE_COND) |
efea75f9 | 1856 | { |
efea75f9 JL |
1857 | edge true_edge; |
1858 | edge false_edge; | |
1859 | ||
726a989a RB |
1860 | tree op0 = gimple_cond_lhs (stmt); |
1861 | tree op1 = gimple_cond_rhs (stmt); | |
1862 | enum tree_code code = gimple_cond_code (stmt); | |
efea75f9 | 1863 | |
726a989a | 1864 | extract_true_false_edges_from_block (bb, &true_edge, &false_edge); |
efea75f9 | 1865 | |
726a989a RB |
1866 | /* Special case comparing booleans against a constant as we |
1867 | know the value of OP0 on both arms of the branch. i.e., we | |
1868 | can record an equivalence for OP0 rather than COND. */ | |
1869 | if ((code == EQ_EXPR || code == NE_EXPR) | |
1870 | && TREE_CODE (op0) == SSA_NAME | |
1871 | && TREE_CODE (TREE_TYPE (op0)) == BOOLEAN_TYPE | |
1872 | && is_gimple_min_invariant (op1)) | |
1873 | { | |
1874 | if (code == EQ_EXPR) | |
1875 | { | |
1876 | edge_info = allocate_edge_info (true_edge); | |
1877 | edge_info->lhs = op0; | |
1878 | edge_info->rhs = (integer_zerop (op1) | |
1879 | ? boolean_false_node | |
1880 | : boolean_true_node); | |
1881 | ||
1882 | edge_info = allocate_edge_info (false_edge); | |
1883 | edge_info->lhs = op0; | |
1884 | edge_info->rhs = (integer_zerop (op1) | |
1885 | ? boolean_true_node | |
1886 | : boolean_false_node); | |
1887 | } | |
1888 | else | |
1889 | { | |
1890 | edge_info = allocate_edge_info (true_edge); | |
1891 | edge_info->lhs = op0; | |
1892 | edge_info->rhs = (integer_zerop (op1) | |
1893 | ? boolean_true_node | |
1894 | : boolean_false_node); | |
1895 | ||
1896 | edge_info = allocate_edge_info (false_edge); | |
1897 | edge_info->lhs = op0; | |
1898 | edge_info->rhs = (integer_zerop (op1) | |
1899 | ? boolean_false_node | |
1900 | : boolean_true_node); | |
1901 | } | |
1902 | } | |
1903 | else if (is_gimple_min_invariant (op0) | |
1904 | && (TREE_CODE (op1) == SSA_NAME | |
1905 | || is_gimple_min_invariant (op1))) | |
1906 | { | |
1907 | tree cond = build2 (code, boolean_type_node, op0, op1); | |
db3927fb | 1908 | tree inverted = invert_truthvalue_loc (loc, cond); |
4db183a2 | 1909 | bool can_infer_simple_equiv |
3d3dbadd | 1910 | = !(HONOR_SIGNED_ZEROS (op0) |
4db183a2 | 1911 | && real_zerop (op0)); |
726a989a RB |
1912 | struct edge_info *edge_info; |
1913 | ||
1914 | edge_info = allocate_edge_info (true_edge); | |
1915 | record_conditions (edge_info, cond, inverted); | |
1916 | ||
4db183a2 | 1917 | if (can_infer_simple_equiv && code == EQ_EXPR) |
726a989a RB |
1918 | { |
1919 | edge_info->lhs = op1; | |
1920 | edge_info->rhs = op0; | |
1921 | } | |
1922 | ||
1923 | edge_info = allocate_edge_info (false_edge); | |
1924 | record_conditions (edge_info, inverted, cond); | |
1925 | ||
4db183a2 | 1926 | if (can_infer_simple_equiv && TREE_CODE (inverted) == EQ_EXPR) |
726a989a RB |
1927 | { |
1928 | edge_info->lhs = op1; | |
1929 | edge_info->rhs = op0; | |
1930 | } | |
1931 | } | |
1932 | ||
1933 | else if (TREE_CODE (op0) == SSA_NAME | |
4db183a2 EB |
1934 | && (TREE_CODE (op1) == SSA_NAME |
1935 | || is_gimple_min_invariant (op1))) | |
726a989a RB |
1936 | { |
1937 | tree cond = build2 (code, boolean_type_node, op0, op1); | |
db3927fb | 1938 | tree inverted = invert_truthvalue_loc (loc, cond); |
4db183a2 | 1939 | bool can_infer_simple_equiv |
3d3dbadd | 1940 | = !(HONOR_SIGNED_ZEROS (op1) |
4db183a2 | 1941 | && (TREE_CODE (op1) == SSA_NAME || real_zerop (op1))); |
726a989a RB |
1942 | struct edge_info *edge_info; |
1943 | ||
1944 | edge_info = allocate_edge_info (true_edge); | |
1945 | record_conditions (edge_info, cond, inverted); | |
1946 | ||
4db183a2 | 1947 | if (can_infer_simple_equiv && code == EQ_EXPR) |
726a989a RB |
1948 | { |
1949 | edge_info->lhs = op0; | |
1950 | edge_info->rhs = op1; | |
1951 | } | |
1952 | ||
1953 | edge_info = allocate_edge_info (false_edge); | |
1954 | record_conditions (edge_info, inverted, cond); | |
1955 | ||
4db183a2 | 1956 | if (can_infer_simple_equiv && TREE_CODE (inverted) == EQ_EXPR) |
726a989a RB |
1957 | { |
1958 | edge_info->lhs = op0; | |
1959 | edge_info->rhs = op1; | |
1960 | } | |
1961 | } | |
1962 | } | |
1963 | ||
1964 | /* ??? TRUTH_NOT_EXPR can create an equivalence too. */ | |
efea75f9 JL |
1965 | } |
1966 | } | |
1967 | ||
4d9192b5 TS |
1968 | void |
1969 | dom_opt_dom_walker::before_dom_children (basic_block bb) | |
6de9cd9a | 1970 | { |
ccf5c864 PB |
1971 | gimple_stmt_iterator gsi; |
1972 | ||
1973 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1974 | fprintf (dump_file, "\n\nOptimizing block #%d\n\n", bb->index); | |
1975 | ||
1976 | /* Push a marker on the stacks of local information so that we know how | |
1977 | far to unwind when we finalize this block. */ | |
b00734df RB |
1978 | avail_exprs_stack.safe_push |
1979 | (std::pair<expr_hash_elt_t, expr_hash_elt_t> (NULL, NULL)); | |
9771b263 | 1980 | const_and_copies_stack.safe_push (NULL_TREE); |
ccf5c864 PB |
1981 | |
1982 | record_equivalences_from_incoming_edge (bb); | |
1983 | ||
1984 | /* PHI nodes can create equivalences too. */ | |
1985 | record_equivalences_from_phis (bb); | |
1986 | ||
13a3e5b6 BS |
1987 | /* Create equivalences from redundant PHIs. PHIs are only truly |
1988 | redundant when they exist in the same block, so push another | |
1989 | marker and unwind right afterwards. */ | |
b00734df RB |
1990 | avail_exprs_stack.safe_push |
1991 | (std::pair<expr_hash_elt_t, expr_hash_elt_t> (NULL, NULL)); | |
13a3e5b6 BS |
1992 | for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
1993 | eliminate_redundant_computations (&gsi); | |
1994 | remove_local_expressions_from_table (); | |
1995 | ||
ccf5c864 PB |
1996 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
1997 | optimize_stmt (bb, gsi); | |
1998 | ||
1999 | /* Now prepare to process dominated blocks. */ | |
efea75f9 | 2000 | record_edge_info (bb); |
b16caf72 | 2001 | cprop_into_successor_phis (bb); |
6de9cd9a DN |
2002 | } |
2003 | ||
ccf5c864 PB |
2004 | /* We have finished processing the dominator children of BB, perform |
2005 | any finalization actions in preparation for leaving this node in | |
2006 | the dominator tree. */ | |
2007 | ||
4d9192b5 TS |
2008 | void |
2009 | dom_opt_dom_walker::after_dom_children (basic_block bb) | |
ccf5c864 PB |
2010 | { |
2011 | gimple last; | |
2012 | ||
2013 | /* If we have an outgoing edge to a block with multiple incoming and | |
2014 | outgoing edges, then we may be able to thread the edge, i.e., we | |
2015 | may be able to statically determine which of the outgoing edges | |
2016 | will be traversed when the incoming edge from BB is traversed. */ | |
2017 | if (single_succ_p (bb) | |
2018 | && (single_succ_edge (bb)->flags & EDGE_ABNORMAL) == 0 | |
2019 | && potentially_threadable_block (single_succ (bb))) | |
2020 | { | |
4d9192b5 | 2021 | thread_across_edge (single_succ_edge (bb)); |
ccf5c864 PB |
2022 | } |
2023 | else if ((last = last_stmt (bb)) | |
2024 | && gimple_code (last) == GIMPLE_COND | |
2025 | && EDGE_COUNT (bb->succs) == 2 | |
2026 | && (EDGE_SUCC (bb, 0)->flags & EDGE_ABNORMAL) == 0 | |
2027 | && (EDGE_SUCC (bb, 1)->flags & EDGE_ABNORMAL) == 0) | |
2028 | { | |
2029 | edge true_edge, false_edge; | |
2030 | ||
2031 | extract_true_false_edges_from_block (bb, &true_edge, &false_edge); | |
2032 | ||
2033 | /* Only try to thread the edge if it reaches a target block with | |
2034 | more than one predecessor and more than one successor. */ | |
2035 | if (potentially_threadable_block (true_edge->dest)) | |
83ae86f5 | 2036 | thread_across_edge (true_edge); |
ccf5c864 PB |
2037 | |
2038 | /* Similarly for the ELSE arm. */ | |
2039 | if (potentially_threadable_block (false_edge->dest)) | |
83ae86f5 | 2040 | thread_across_edge (false_edge); |
ccf5c864 | 2041 | |
ccf5c864 PB |
2042 | } |
2043 | ||
83ae86f5 | 2044 | /* These remove expressions local to BB from the tables. */ |
ccf5c864 PB |
2045 | remove_local_expressions_from_table (); |
2046 | restore_vars_to_original_value (); | |
ccf5c864 PB |
2047 | } |
2048 | ||
6de9cd9a DN |
2049 | /* Search for redundant computations in STMT. If any are found, then |
2050 | replace them with the variable holding the result of the computation. | |
2051 | ||
2052 | If safe, record this expression into the available expression hash | |
2053 | table. */ | |
2054 | ||
87c93592 | 2055 | static void |
726a989a | 2056 | eliminate_redundant_computations (gimple_stmt_iterator* gsi) |
6de9cd9a | 2057 | { |
726a989a | 2058 | tree expr_type; |
6de9cd9a | 2059 | tree cached_lhs; |
13a3e5b6 | 2060 | tree def; |
726a989a | 2061 | bool insert = true; |
726a989a | 2062 | bool assigns_var_p = false; |
6de9cd9a | 2063 | |
726a989a RB |
2064 | gimple stmt = gsi_stmt (*gsi); |
2065 | ||
13a3e5b6 BS |
2066 | if (gimple_code (stmt) == GIMPLE_PHI) |
2067 | def = gimple_phi_result (stmt); | |
2068 | else | |
2069 | def = gimple_get_lhs (stmt); | |
6de9cd9a DN |
2070 | |
2071 | /* Certain expressions on the RHS can be optimized away, but can not | |
471854f8 | 2072 | themselves be entered into the hash tables. */ |
ff88c5aa | 2073 | if (! def |
6de9cd9a DN |
2074 | || TREE_CODE (def) != SSA_NAME |
2075 | || SSA_NAME_OCCURS_IN_ABNORMAL_PHI (def) | |
5006671f | 2076 | || gimple_vdef (stmt) |
f67e783f ZD |
2077 | /* Do not record equivalences for increments of ivs. This would create |
2078 | overlapping live ranges for a very questionable gain. */ | |
2079 | || simple_iv_increment_p (stmt)) | |
6de9cd9a DN |
2080 | insert = false; |
2081 | ||
2082 | /* Check if the expression has been computed before. */ | |
48732f23 | 2083 | cached_lhs = lookup_avail_expr (stmt, insert); |
6de9cd9a | 2084 | |
6de9cd9a DN |
2085 | opt_stats.num_exprs_considered++; |
2086 | ||
726a989a RB |
2087 | /* Get the type of the expression we are trying to optimize. */ |
2088 | if (is_gimple_assign (stmt)) | |
019b02f1 | 2089 | { |
726a989a RB |
2090 | expr_type = TREE_TYPE (gimple_assign_lhs (stmt)); |
2091 | assigns_var_p = true; | |
019b02f1 | 2092 | } |
726a989a RB |
2093 | else if (gimple_code (stmt) == GIMPLE_COND) |
2094 | expr_type = boolean_type_node; | |
2095 | else if (is_gimple_call (stmt)) | |
019b02f1 | 2096 | { |
726a989a RB |
2097 | gcc_assert (gimple_call_lhs (stmt)); |
2098 | expr_type = TREE_TYPE (gimple_call_lhs (stmt)); | |
2099 | assigns_var_p = true; | |
019b02f1 | 2100 | } |
538dd0b7 DM |
2101 | else if (gswitch *swtch_stmt = dyn_cast <gswitch *> (stmt)) |
2102 | expr_type = TREE_TYPE (gimple_switch_index (swtch_stmt)); | |
13a3e5b6 BS |
2103 | else if (gimple_code (stmt) == GIMPLE_PHI) |
2104 | /* We can't propagate into a phi, so the logic below doesn't apply. | |
2105 | Instead record an equivalence between the cached LHS and the | |
2106 | PHI result of this statement, provided they are in the same block. | |
2107 | This should be sufficient to kill the redundant phi. */ | |
2108 | { | |
2109 | if (def && cached_lhs) | |
2110 | record_const_or_copy (def, cached_lhs); | |
2111 | return; | |
2112 | } | |
726a989a RB |
2113 | else |
2114 | gcc_unreachable (); | |
2115 | ||
2116 | if (!cached_lhs) | |
87c93592 | 2117 | return; |
6de9cd9a DN |
2118 | |
2119 | /* It is safe to ignore types here since we have already done | |
2120 | type checking in the hashing and equality routines. In fact | |
2121 | type checking here merely gets in the way of constant | |
2122 | propagation. Also, make sure that it is safe to propagate | |
726a989a RB |
2123 | CACHED_LHS into the expression in STMT. */ |
2124 | if ((TREE_CODE (cached_lhs) != SSA_NAME | |
2125 | && (assigns_var_p | |
2126 | || useless_type_conversion_p (expr_type, TREE_TYPE (cached_lhs)))) | |
2127 | || may_propagate_copy_into_stmt (stmt, cached_lhs)) | |
2128 | { | |
77a74ed7 NF |
2129 | gcc_checking_assert (TREE_CODE (cached_lhs) == SSA_NAME |
2130 | || is_gimple_min_invariant (cached_lhs)); | |
726a989a | 2131 | |
6de9cd9a DN |
2132 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2133 | { | |
2134 | fprintf (dump_file, " Replaced redundant expr '"); | |
726a989a | 2135 | print_gimple_expr (dump_file, stmt, 0, dump_flags); |
6de9cd9a DN |
2136 | fprintf (dump_file, "' with '"); |
2137 | print_generic_expr (dump_file, cached_lhs, dump_flags); | |
726a989a | 2138 | fprintf (dump_file, "'\n"); |
6de9cd9a DN |
2139 | } |
2140 | ||
2141 | opt_stats.num_re++; | |
b8698a0f | 2142 | |
726a989a RB |
2143 | if (assigns_var_p |
2144 | && !useless_type_conversion_p (expr_type, TREE_TYPE (cached_lhs))) | |
2145 | cached_lhs = fold_convert (expr_type, cached_lhs); | |
6de9cd9a | 2146 | |
726a989a RB |
2147 | propagate_tree_value_into_stmt (gsi, cached_lhs); |
2148 | ||
2149 | /* Since it is always necessary to mark the result as modified, | |
2150 | perhaps we should move this into propagate_tree_value_into_stmt | |
2151 | itself. */ | |
2152 | gimple_set_modified (gsi_stmt (*gsi), true); | |
2153 | } | |
6de9cd9a DN |
2154 | } |
2155 | ||
726a989a | 2156 | /* STMT, a GIMPLE_ASSIGN, may create certain equivalences, in either |
6de9cd9a DN |
2157 | the available expressions table or the const_and_copies table. |
2158 | Detect and record those equivalences. */ | |
726a989a RB |
2159 | /* We handle only very simple copy equivalences here. The heavy |
2160 | lifing is done by eliminate_redundant_computations. */ | |
6de9cd9a DN |
2161 | |
2162 | static void | |
726a989a | 2163 | record_equivalences_from_stmt (gimple stmt, int may_optimize_p) |
6de9cd9a | 2164 | { |
726a989a RB |
2165 | tree lhs; |
2166 | enum tree_code lhs_code; | |
6de9cd9a | 2167 | |
726a989a RB |
2168 | gcc_assert (is_gimple_assign (stmt)); |
2169 | ||
2170 | lhs = gimple_assign_lhs (stmt); | |
2171 | lhs_code = TREE_CODE (lhs); | |
6de9cd9a | 2172 | |
726a989a | 2173 | if (lhs_code == SSA_NAME |
7e673273 | 2174 | && gimple_assign_single_p (stmt)) |
726a989a RB |
2175 | { |
2176 | tree rhs = gimple_assign_rhs1 (stmt); | |
b8698a0f | 2177 | |
6de9cd9a DN |
2178 | /* If the RHS of the assignment is a constant or another variable that |
2179 | may be propagated, register it in the CONST_AND_COPIES table. We | |
2180 | do not need to record unwind data for this, since this is a true | |
1ea7e6ad | 2181 | assignment and not an equivalence inferred from a comparison. All |
6de9cd9a DN |
2182 | uses of this ssa name are dominated by this assignment, so unwinding |
2183 | just costs time and space. */ | |
2184 | if (may_optimize_p | |
2185 | && (TREE_CODE (rhs) == SSA_NAME | |
2186 | || is_gimple_min_invariant (rhs))) | |
726a989a RB |
2187 | { |
2188 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2189 | { | |
2190 | fprintf (dump_file, "==== ASGN "); | |
2191 | print_generic_expr (dump_file, lhs, 0); | |
2192 | fprintf (dump_file, " = "); | |
2193 | print_generic_expr (dump_file, rhs, 0); | |
2194 | fprintf (dump_file, "\n"); | |
2195 | } | |
2196 | ||
448ee662 | 2197 | set_ssa_name_value (lhs, rhs); |
726a989a | 2198 | } |
6de9cd9a DN |
2199 | } |
2200 | ||
b00734df RB |
2201 | /* Make sure we can propagate &x + CST. */ |
2202 | if (lhs_code == SSA_NAME | |
2203 | && gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR | |
2204 | && TREE_CODE (gimple_assign_rhs1 (stmt)) == ADDR_EXPR | |
2205 | && TREE_CODE (gimple_assign_rhs2 (stmt)) == INTEGER_CST) | |
2206 | { | |
2207 | tree op0 = gimple_assign_rhs1 (stmt); | |
2208 | tree op1 = gimple_assign_rhs2 (stmt); | |
2209 | tree new_rhs | |
2210 | = build_fold_addr_expr (fold_build2 (MEM_REF, | |
2211 | TREE_TYPE (TREE_TYPE (op0)), | |
2212 | unshare_expr (op0), | |
2213 | fold_convert (ptr_type_node, | |
2214 | op1))); | |
2215 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2216 | { | |
2217 | fprintf (dump_file, "==== ASGN "); | |
2218 | print_generic_expr (dump_file, lhs, 0); | |
2219 | fprintf (dump_file, " = "); | |
2220 | print_generic_expr (dump_file, new_rhs, 0); | |
2221 | fprintf (dump_file, "\n"); | |
2222 | } | |
2223 | ||
2224 | set_ssa_name_value (lhs, new_rhs); | |
2225 | } | |
2226 | ||
6de9cd9a DN |
2227 | /* A memory store, even an aliased store, creates a useful |
2228 | equivalence. By exchanging the LHS and RHS, creating suitable | |
2229 | vops and recording the result in the available expression table, | |
2230 | we may be able to expose more redundant loads. */ | |
726a989a RB |
2231 | if (!gimple_has_volatile_ops (stmt) |
2232 | && gimple_references_memory_p (stmt) | |
2233 | && gimple_assign_single_p (stmt) | |
2234 | && (TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME | |
2235 | || is_gimple_min_invariant (gimple_assign_rhs1 (stmt))) | |
6de9cd9a DN |
2236 | && !is_gimple_reg (lhs)) |
2237 | { | |
726a989a | 2238 | tree rhs = gimple_assign_rhs1 (stmt); |
538dd0b7 | 2239 | gassign *new_stmt; |
6de9cd9a | 2240 | |
cf3135aa | 2241 | /* Build a new statement with the RHS and LHS exchanged. */ |
726a989a RB |
2242 | if (TREE_CODE (rhs) == SSA_NAME) |
2243 | { | |
2244 | /* NOTE tuples. The call to gimple_build_assign below replaced | |
2245 | a call to build_gimple_modify_stmt, which did not set the | |
2246 | SSA_NAME_DEF_STMT on the LHS of the assignment. Doing so | |
2247 | may cause an SSA validation failure, as the LHS may be a | |
2248 | default-initialized name and should have no definition. I'm | |
2249 | a bit dubious of this, as the artificial statement that we | |
2250 | generate here may in fact be ill-formed, but it is simply | |
2251 | used as an internal device in this pass, and never becomes | |
2252 | part of the CFG. */ | |
2253 | gimple defstmt = SSA_NAME_DEF_STMT (rhs); | |
2254 | new_stmt = gimple_build_assign (rhs, lhs); | |
2255 | SSA_NAME_DEF_STMT (rhs) = defstmt; | |
2256 | } | |
2257 | else | |
2258 | new_stmt = gimple_build_assign (rhs, lhs); | |
2259 | ||
5006671f | 2260 | gimple_set_vuse (new_stmt, gimple_vdef (stmt)); |
6de9cd9a | 2261 | |
cf3135aa RG |
2262 | /* Finally enter the statement into the available expression |
2263 | table. */ | |
2264 | lookup_avail_expr (new_stmt, true); | |
6de9cd9a DN |
2265 | } |
2266 | } | |
2267 | ||
ff2ad0f7 DN |
2268 | /* Replace *OP_P in STMT with any known equivalent value for *OP_P from |
2269 | CONST_AND_COPIES. */ | |
2270 | ||
87c93592 | 2271 | static void |
726a989a | 2272 | cprop_operand (gimple stmt, use_operand_p op_p) |
ff2ad0f7 | 2273 | { |
ff2ad0f7 DN |
2274 | tree val; |
2275 | tree op = USE_FROM_PTR (op_p); | |
2276 | ||
2277 | /* If the operand has a known constant value or it is known to be a | |
2278 | copy of some other variable, use the value or copy stored in | |
2279 | CONST_AND_COPIES. */ | |
3aecd08b | 2280 | val = SSA_NAME_VALUE (op); |
c9145754 | 2281 | if (val && val != op) |
ff2ad0f7 | 2282 | { |
aa24864c | 2283 | /* Do not replace hard register operands in asm statements. */ |
726a989a | 2284 | if (gimple_code (stmt) == GIMPLE_ASM |
aa24864c | 2285 | && !may_propagate_copy_into_asm (op)) |
87c93592 | 2286 | return; |
aa24864c | 2287 | |
ff2ad0f7 DN |
2288 | /* Certain operands are not allowed to be copy propagated due |
2289 | to their interaction with exception handling and some GCC | |
2290 | extensions. */ | |
66e8b99c | 2291 | if (!may_propagate_copy (op, val)) |
87c93592 | 2292 | return; |
66e8b99c | 2293 | |
e9d85fa6 RG |
2294 | /* Do not propagate copies into simple IV increment statements. |
2295 | See PR23821 for how this can disturb IV analysis. */ | |
2296 | if (TREE_CODE (val) != INTEGER_CST | |
2297 | && simple_iv_increment_p (stmt)) | |
2298 | return; | |
2299 | ||
ff2ad0f7 DN |
2300 | /* Dump details. */ |
2301 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2302 | { | |
2303 | fprintf (dump_file, " Replaced '"); | |
2304 | print_generic_expr (dump_file, op, dump_flags); | |
2305 | fprintf (dump_file, "' with %s '", | |
2306 | (TREE_CODE (val) != SSA_NAME ? "constant" : "variable")); | |
2307 | print_generic_expr (dump_file, val, dump_flags); | |
2308 | fprintf (dump_file, "'\n"); | |
2309 | } | |
2310 | ||
0bca51f0 DN |
2311 | if (TREE_CODE (val) != SSA_NAME) |
2312 | opt_stats.num_const_prop++; | |
2313 | else | |
2314 | opt_stats.num_copy_prop++; | |
2315 | ||
ff2ad0f7 DN |
2316 | propagate_value (op_p, val); |
2317 | ||
2318 | /* And note that we modified this statement. This is now | |
2319 | safe, even if we changed virtual operands since we will | |
2320 | rescan the statement and rewrite its operands again. */ | |
726a989a | 2321 | gimple_set_modified (stmt, true); |
ff2ad0f7 | 2322 | } |
ff2ad0f7 DN |
2323 | } |
2324 | ||
2325 | /* CONST_AND_COPIES is a table which maps an SSA_NAME to the current | |
b8698a0f | 2326 | known value for that SSA_NAME (or NULL if no value is known). |
ff2ad0f7 DN |
2327 | |
2328 | Propagate values from CONST_AND_COPIES into the uses, vuses and | |
cfaab3a9 | 2329 | vdef_ops of STMT. */ |
ff2ad0f7 | 2330 | |
87c93592 | 2331 | static void |
726a989a | 2332 | cprop_into_stmt (gimple stmt) |
ff2ad0f7 | 2333 | { |
4c124b4c AM |
2334 | use_operand_p op_p; |
2335 | ssa_op_iter iter; | |
ff2ad0f7 | 2336 | |
2a86de57 RB |
2337 | FOR_EACH_SSA_USE_OPERAND (op_p, stmt, iter, SSA_OP_USE) |
2338 | cprop_operand (stmt, op_p); | |
ff2ad0f7 DN |
2339 | } |
2340 | ||
206048bd | 2341 | /* Optimize the statement pointed to by iterator SI. |
b8698a0f | 2342 | |
6de9cd9a DN |
2343 | We try to perform some simplistic global redundancy elimination and |
2344 | constant propagation: | |
2345 | ||
2346 | 1- To detect global redundancy, we keep track of expressions that have | |
2347 | been computed in this block and its dominators. If we find that the | |
2348 | same expression is computed more than once, we eliminate repeated | |
2349 | computations by using the target of the first one. | |
2350 | ||
2351 | 2- Constant values and copy assignments. This is used to do very | |
2352 | simplistic constant and copy propagation. When a constant or copy | |
2353 | assignment is found, we map the value on the RHS of the assignment to | |
2354 | the variable in the LHS in the CONST_AND_COPIES table. */ | |
2355 | ||
2356 | static void | |
ccf5c864 | 2357 | optimize_stmt (basic_block bb, gimple_stmt_iterator si) |
6de9cd9a | 2358 | { |
726a989a | 2359 | gimple stmt, old_stmt; |
6de9cd9a | 2360 | bool may_optimize_p; |
c5cac099 | 2361 | bool modified_p = false; |
6de9cd9a | 2362 | |
726a989a | 2363 | old_stmt = stmt = gsi_stmt (si); |
b8698a0f | 2364 | |
6de9cd9a DN |
2365 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2366 | { | |
2367 | fprintf (dump_file, "Optimizing statement "); | |
726a989a | 2368 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); |
6de9cd9a DN |
2369 | } |
2370 | ||
2a86de57 | 2371 | if (gimple_code (stmt) == GIMPLE_COND) |
538dd0b7 | 2372 | canonicalize_comparison (as_a <gcond *> (stmt)); |
2a86de57 RB |
2373 | |
2374 | update_stmt_if_modified (stmt); | |
2375 | opt_stats.num_stmts++; | |
2376 | ||
cfaab3a9 | 2377 | /* Const/copy propagate into USES, VUSES and the RHS of VDEFs. */ |
87c93592 | 2378 | cprop_into_stmt (stmt); |
6de9cd9a DN |
2379 | |
2380 | /* If the statement has been modified with constant replacements, | |
2381 | fold its RHS before checking for redundant computations. */ | |
726a989a | 2382 | if (gimple_modified_p (stmt)) |
6de9cd9a | 2383 | { |
726a989a | 2384 | tree rhs = NULL; |
6cedb4ac | 2385 | |
6de9cd9a DN |
2386 | /* Try to fold the statement making sure that STMT is kept |
2387 | up to date. */ | |
726a989a | 2388 | if (fold_stmt (&si)) |
6de9cd9a | 2389 | { |
726a989a | 2390 | stmt = gsi_stmt (si); |
076ba157 | 2391 | gimple_set_modified (stmt, true); |
6de9cd9a DN |
2392 | |
2393 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2394 | { | |
2395 | fprintf (dump_file, " Folded to: "); | |
726a989a | 2396 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); |
6de9cd9a DN |
2397 | } |
2398 | } | |
2399 | ||
726a989a RB |
2400 | /* We only need to consider cases that can yield a gimple operand. */ |
2401 | if (gimple_assign_single_p (stmt)) | |
2402 | rhs = gimple_assign_rhs1 (stmt); | |
2403 | else if (gimple_code (stmt) == GIMPLE_GOTO) | |
2404 | rhs = gimple_goto_dest (stmt); | |
538dd0b7 | 2405 | else if (gswitch *swtch_stmt = dyn_cast <gswitch *> (stmt)) |
726a989a | 2406 | /* This should never be an ADDR_EXPR. */ |
538dd0b7 | 2407 | rhs = gimple_switch_index (swtch_stmt); |
726a989a | 2408 | |
6cedb4ac | 2409 | if (rhs && TREE_CODE (rhs) == ADDR_EXPR) |
726a989a | 2410 | recompute_tree_invariant_for_addr_expr (rhs); |
6cedb4ac | 2411 | |
c5cac099 JJ |
2412 | /* Indicate that maybe_clean_or_replace_eh_stmt needs to be called, |
2413 | even if fold_stmt updated the stmt already and thus cleared | |
2414 | gimple_modified_p flag on it. */ | |
2415 | modified_p = true; | |
6de9cd9a DN |
2416 | } |
2417 | ||
2418 | /* Check for redundant computations. Do this optimization only | |
2419 | for assignments that have no volatile ops and conditionals. */ | |
d829c408 RG |
2420 | may_optimize_p = (!gimple_has_side_effects (stmt) |
2421 | && (is_gimple_assign (stmt) | |
726a989a | 2422 | || (is_gimple_call (stmt) |
d829c408 | 2423 | && gimple_call_lhs (stmt) != NULL_TREE) |
726a989a RB |
2424 | || gimple_code (stmt) == GIMPLE_COND |
2425 | || gimple_code (stmt) == GIMPLE_SWITCH)); | |
6de9cd9a DN |
2426 | |
2427 | if (may_optimize_p) | |
726a989a | 2428 | { |
44e10129 MM |
2429 | if (gimple_code (stmt) == GIMPLE_CALL) |
2430 | { | |
2431 | /* Resolve __builtin_constant_p. If it hasn't been | |
2432 | folded to integer_one_node by now, it's fairly | |
2433 | certain that the value simply isn't constant. */ | |
2434 | tree callee = gimple_call_fndecl (stmt); | |
2435 | if (callee | |
2436 | && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL | |
2437 | && DECL_FUNCTION_CODE (callee) == BUILT_IN_CONSTANT_P) | |
2438 | { | |
2439 | propagate_tree_value_into_stmt (&si, integer_zero_node); | |
2440 | stmt = gsi_stmt (si); | |
2441 | } | |
2442 | } | |
aabf6a03 RG |
2443 | |
2444 | update_stmt_if_modified (stmt); | |
2445 | eliminate_redundant_computations (&si); | |
2446 | stmt = gsi_stmt (si); | |
565b8886 RG |
2447 | |
2448 | /* Perform simple redundant store elimination. */ | |
2449 | if (gimple_assign_single_p (stmt) | |
2450 | && TREE_CODE (gimple_assign_lhs (stmt)) != SSA_NAME) | |
2451 | { | |
2452 | tree lhs = gimple_assign_lhs (stmt); | |
2453 | tree rhs = gimple_assign_rhs1 (stmt); | |
2454 | tree cached_lhs; | |
538dd0b7 | 2455 | gassign *new_stmt; |
565b8886 RG |
2456 | if (TREE_CODE (rhs) == SSA_NAME) |
2457 | { | |
2458 | tree tem = SSA_NAME_VALUE (rhs); | |
2459 | if (tem) | |
2460 | rhs = tem; | |
2461 | } | |
2462 | /* Build a new statement with the RHS and LHS exchanged. */ | |
2463 | if (TREE_CODE (rhs) == SSA_NAME) | |
2464 | { | |
2465 | gimple defstmt = SSA_NAME_DEF_STMT (rhs); | |
2466 | new_stmt = gimple_build_assign (rhs, lhs); | |
2467 | SSA_NAME_DEF_STMT (rhs) = defstmt; | |
2468 | } | |
2469 | else | |
2470 | new_stmt = gimple_build_assign (rhs, lhs); | |
2471 | gimple_set_vuse (new_stmt, gimple_vuse (stmt)); | |
2472 | cached_lhs = lookup_avail_expr (new_stmt, false); | |
2473 | if (cached_lhs | |
2474 | && rhs == cached_lhs) | |
2475 | { | |
2476 | basic_block bb = gimple_bb (stmt); | |
565b8886 | 2477 | unlink_stmt_vdef (stmt); |
b5b3ec3e | 2478 | if (gsi_remove (&si, true)) |
565b8886 RG |
2479 | { |
2480 | bitmap_set_bit (need_eh_cleanup, bb->index); | |
2481 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2482 | fprintf (dump_file, " Flagged to clear EH edges.\n"); | |
2483 | } | |
3d3f2249 | 2484 | release_defs (stmt); |
565b8886 RG |
2485 | return; |
2486 | } | |
2487 | } | |
726a989a | 2488 | } |
6de9cd9a DN |
2489 | |
2490 | /* Record any additional equivalences created by this statement. */ | |
726a989a RB |
2491 | if (is_gimple_assign (stmt)) |
2492 | record_equivalences_from_stmt (stmt, may_optimize_p); | |
6de9cd9a | 2493 | |
6de9cd9a DN |
2494 | /* If STMT is a COND_EXPR and it was modified, then we may know |
2495 | where it goes. If that is the case, then mark the CFG as altered. | |
2496 | ||
2497 | This will cause us to later call remove_unreachable_blocks and | |
b8698a0f | 2498 | cleanup_tree_cfg when it is safe to do so. It is not safe to |
6de9cd9a DN |
2499 | clean things up here since removal of edges and such can trigger |
2500 | the removal of PHI nodes, which in turn can release SSA_NAMEs to | |
2501 | the manager. | |
2502 | ||
2503 | That's all fine and good, except that once SSA_NAMEs are released | |
2504 | to the manager, we must not call create_ssa_name until all references | |
2505 | to released SSA_NAMEs have been eliminated. | |
2506 | ||
2507 | All references to the deleted SSA_NAMEs can not be eliminated until | |
2508 | we remove unreachable blocks. | |
2509 | ||
2510 | We can not remove unreachable blocks until after we have completed | |
2511 | any queued jump threading. | |
2512 | ||
2513 | We can not complete any queued jump threads until we have taken | |
2514 | appropriate variables out of SSA form. Taking variables out of | |
2515 | SSA form can call create_ssa_name and thus we lose. | |
2516 | ||
2517 | Ultimately I suspect we're going to need to change the interface | |
2518 | into the SSA_NAME manager. */ | |
c5cac099 | 2519 | if (gimple_modified_p (stmt) || modified_p) |
6de9cd9a DN |
2520 | { |
2521 | tree val = NULL; | |
b8698a0f | 2522 | |
aabf6a03 | 2523 | update_stmt_if_modified (stmt); |
6de9cd9a | 2524 | |
726a989a | 2525 | if (gimple_code (stmt) == GIMPLE_COND) |
db3927fb AH |
2526 | val = fold_binary_loc (gimple_location (stmt), |
2527 | gimple_cond_code (stmt), boolean_type_node, | |
726a989a | 2528 | gimple_cond_lhs (stmt), gimple_cond_rhs (stmt)); |
538dd0b7 DM |
2529 | else if (gswitch *swtch_stmt = dyn_cast <gswitch *> (stmt)) |
2530 | val = gimple_switch_index (swtch_stmt); | |
6de9cd9a | 2531 | |
1eaba2f2 | 2532 | if (val && TREE_CODE (val) == INTEGER_CST && find_taken_edge (bb, val)) |
6de9cd9a | 2533 | cfg_altered = true; |
1eaba2f2 RH |
2534 | |
2535 | /* If we simplified a statement in such a way as to be shown that it | |
2536 | cannot trap, update the eh information and the cfg to match. */ | |
af47810a | 2537 | if (maybe_clean_or_replace_eh_stmt (old_stmt, stmt)) |
1eaba2f2 RH |
2538 | { |
2539 | bitmap_set_bit (need_eh_cleanup, bb->index); | |
2540 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2541 | fprintf (dump_file, " Flagged to clear EH edges.\n"); | |
2542 | } | |
6de9cd9a | 2543 | } |
6de9cd9a DN |
2544 | } |
2545 | ||
b00734df RB |
2546 | /* Helper for walk_non_aliased_vuses. Determine if we arrived at |
2547 | the desired memory state. */ | |
2548 | ||
2549 | static void * | |
2550 | vuse_eq (ao_ref *, tree vuse1, unsigned int cnt, void *data) | |
2551 | { | |
2552 | tree vuse2 = (tree) data; | |
2553 | if (vuse1 == vuse2) | |
2554 | return data; | |
2555 | ||
2556 | /* This bounds the stmt walks we perform on reference lookups | |
2557 | to O(1) instead of O(N) where N is the number of dominating | |
2558 | stores leading to a candidate. We re-use the SCCVN param | |
2559 | for this as it is basically the same complexity. */ | |
2560 | if (cnt > (unsigned) PARAM_VALUE (PARAM_SCCVN_MAX_ALIAS_QUERIES_PER_ACCESS)) | |
2561 | return (void *)-1; | |
2562 | ||
2563 | return NULL; | |
2564 | } | |
2565 | ||
726a989a RB |
2566 | /* Search for an existing instance of STMT in the AVAIL_EXPRS table. |
2567 | If found, return its LHS. Otherwise insert STMT in the table and | |
2568 | return NULL_TREE. | |
6de9cd9a | 2569 | |
726a989a RB |
2570 | Also, when an expression is first inserted in the table, it is also |
2571 | is also added to AVAIL_EXPRS_STACK, so that it can be removed when | |
2572 | we finish processing this block and its children. */ | |
6de9cd9a DN |
2573 | |
2574 | static tree | |
726a989a | 2575 | lookup_avail_expr (gimple stmt, bool insert) |
6de9cd9a | 2576 | { |
4a8fb1a1 | 2577 | expr_hash_elt **slot; |
6de9cd9a DN |
2578 | tree lhs; |
2579 | tree temp; | |
a7d04a53 | 2580 | struct expr_hash_elt element; |
6de9cd9a | 2581 | |
13a3e5b6 BS |
2582 | /* Get LHS of phi, assignment, or call; else NULL_TREE. */ |
2583 | if (gimple_code (stmt) == GIMPLE_PHI) | |
2584 | lhs = gimple_phi_result (stmt); | |
2585 | else | |
2586 | lhs = gimple_get_lhs (stmt); | |
6de9cd9a | 2587 | |
a7d04a53 | 2588 | initialize_hash_element (stmt, lhs, &element); |
6de9cd9a | 2589 | |
726a989a RB |
2590 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2591 | { | |
2592 | fprintf (dump_file, "LKUP "); | |
a7d04a53 | 2593 | print_expr_hash_elt (dump_file, &element); |
726a989a RB |
2594 | } |
2595 | ||
6de9cd9a DN |
2596 | /* Don't bother remembering constant assignments and copy operations. |
2597 | Constants and copy operations are handled by the constant/copy propagator | |
2598 | in optimize_stmt. */ | |
a7d04a53 RG |
2599 | if (element.expr.kind == EXPR_SINGLE |
2600 | && (TREE_CODE (element.expr.ops.single.rhs) == SSA_NAME | |
2601 | || is_gimple_min_invariant (element.expr.ops.single.rhs))) | |
2602 | return NULL_TREE; | |
6de9cd9a | 2603 | |
6de9cd9a | 2604 | /* Finally try to find the expression in the main expression hash table. */ |
c203e8a7 | 2605 | slot = avail_exprs->find_slot (&element, (insert ? INSERT : NO_INSERT)); |
6de9cd9a | 2606 | if (slot == NULL) |
b6db991c RG |
2607 | { |
2608 | free_expr_hash_elt_contents (&element); | |
2609 | return NULL_TREE; | |
2610 | } | |
2611 | else if (*slot == NULL) | |
6de9cd9a | 2612 | { |
a7d04a53 RG |
2613 | struct expr_hash_elt *element2 = XNEW (struct expr_hash_elt); |
2614 | *element2 = element; | |
2615 | element2->stamp = element2; | |
4a8fb1a1 | 2616 | *slot = element2; |
726a989a RB |
2617 | |
2618 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2619 | { | |
2620 | fprintf (dump_file, "2>>> "); | |
a7d04a53 | 2621 | print_expr_hash_elt (dump_file, element2); |
726a989a RB |
2622 | } |
2623 | ||
b00734df RB |
2624 | avail_exprs_stack.safe_push |
2625 | (std::pair<expr_hash_elt_t, expr_hash_elt_t> (element2, NULL)); | |
6de9cd9a DN |
2626 | return NULL_TREE; |
2627 | } | |
b00734df RB |
2628 | |
2629 | /* If we found a redundant memory operation do an alias walk to | |
2630 | check if we can re-use it. */ | |
2631 | if (gimple_vuse (stmt) != (*slot)->vop) | |
2632 | { | |
2633 | tree vuse1 = (*slot)->vop; | |
2634 | tree vuse2 = gimple_vuse (stmt); | |
2635 | /* If we have a load of a register and a candidate in the | |
2636 | hash with vuse1 then try to reach its stmt by walking | |
2637 | up the virtual use-def chain using walk_non_aliased_vuses. | |
2638 | But don't do this when removing expressions from the hash. */ | |
2639 | ao_ref ref; | |
2640 | if (!(vuse1 && vuse2 | |
2641 | && gimple_assign_single_p (stmt) | |
2642 | && TREE_CODE (gimple_assign_lhs (stmt)) == SSA_NAME | |
2643 | && (ao_ref_init (&ref, gimple_assign_rhs1 (stmt)), true) | |
2644 | && walk_non_aliased_vuses (&ref, vuse2, | |
92a5094e | 2645 | vuse_eq, NULL, NULL, vuse1) != NULL)) |
b00734df RB |
2646 | { |
2647 | struct expr_hash_elt *element2 = XNEW (struct expr_hash_elt); | |
2648 | *element2 = element; | |
2649 | element2->stamp = element2; | |
2650 | ||
2651 | /* Insert the expr into the hash by replacing the current | |
2652 | entry and recording the value to restore in the | |
2653 | aval_exprs_stack. */ | |
2654 | avail_exprs_stack.safe_push (std::make_pair (element2, *slot)); | |
2655 | *slot = element2; | |
2656 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2657 | { | |
2658 | fprintf (dump_file, "2>>> "); | |
2659 | print_expr_hash_elt (dump_file, *slot); | |
2660 | } | |
2661 | return NULL_TREE; | |
2662 | } | |
2663 | } | |
2664 | ||
2665 | free_expr_hash_elt_contents (&element); | |
6de9cd9a DN |
2666 | |
2667 | /* Extract the LHS of the assignment so that it can be used as the current | |
2668 | definition of another variable. */ | |
b00734df | 2669 | lhs = (*slot)->lhs; |
6de9cd9a DN |
2670 | |
2671 | /* See if the LHS appears in the CONST_AND_COPIES table. If it does, then | |
2672 | use the value from the const_and_copies table. */ | |
2673 | if (TREE_CODE (lhs) == SSA_NAME) | |
2674 | { | |
3aecd08b | 2675 | temp = SSA_NAME_VALUE (lhs); |
c9145754 | 2676 | if (temp) |
6de9cd9a DN |
2677 | lhs = temp; |
2678 | } | |
2679 | ||
726a989a RB |
2680 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2681 | { | |
2682 | fprintf (dump_file, "FIND: "); | |
2683 | print_generic_expr (dump_file, lhs, 0); | |
2684 | fprintf (dump_file, "\n"); | |
2685 | } | |
2686 | ||
6de9cd9a DN |
2687 | return lhs; |
2688 | } | |
2689 | ||
726a989a RB |
2690 | /* Hashing and equality functions for AVAIL_EXPRS. We compute a value number |
2691 | for expressions using the code of the expression and the SSA numbers of | |
2692 | its operands. */ | |
6de9cd9a DN |
2693 | |
2694 | static hashval_t | |
2695 | avail_expr_hash (const void *p) | |
2696 | { | |
726a989a | 2697 | const struct hashable_expr *expr = &((const struct expr_hash_elt *)p)->expr; |
2bc10537 | 2698 | inchash::hash hstate; |
6de9cd9a | 2699 | |
2bc10537 | 2700 | inchash::add_hashable_expr (expr, hstate); |
6de9cd9a | 2701 | |
2bc10537 | 2702 | return hstate.end (); |
6de9cd9a DN |
2703 | } |
2704 | ||
e67c25c7 JL |
2705 | /* PHI-ONLY copy and constant propagation. This pass is meant to clean |
2706 | up degenerate PHIs created by or exposed by jump threading. */ | |
2707 | ||
726a989a | 2708 | /* Given a statement STMT, which is either a PHI node or an assignment, |
e67c25c7 JL |
2709 | remove it from the IL. */ |
2710 | ||
2711 | static void | |
726a989a | 2712 | remove_stmt_or_phi (gimple stmt) |
e67c25c7 | 2713 | { |
726a989a RB |
2714 | gimple_stmt_iterator gsi = gsi_for_stmt (stmt); |
2715 | ||
2716 | if (gimple_code (stmt) == GIMPLE_PHI) | |
2717 | remove_phi_node (&gsi, true); | |
e67c25c7 JL |
2718 | else |
2719 | { | |
726a989a RB |
2720 | gsi_remove (&gsi, true); |
2721 | release_defs (stmt); | |
e67c25c7 JL |
2722 | } |
2723 | } | |
2724 | ||
726a989a | 2725 | /* Given a statement STMT, which is either a PHI node or an assignment, |
e67c25c7 | 2726 | return the "rhs" of the node, in the case of a non-degenerate |
726a989a | 2727 | phi, NULL is returned. */ |
e67c25c7 JL |
2728 | |
2729 | static tree | |
726a989a | 2730 | get_rhs_or_phi_arg (gimple stmt) |
e67c25c7 | 2731 | { |
726a989a | 2732 | if (gimple_code (stmt) == GIMPLE_PHI) |
538dd0b7 | 2733 | return degenerate_phi_result (as_a <gphi *> (stmt)); |
726a989a RB |
2734 | else if (gimple_assign_single_p (stmt)) |
2735 | return gimple_assign_rhs1 (stmt); | |
2736 | else | |
2737 | gcc_unreachable (); | |
e67c25c7 JL |
2738 | } |
2739 | ||
2740 | ||
726a989a | 2741 | /* Given a statement STMT, which is either a PHI node or an assignment, |
e67c25c7 JL |
2742 | return the "lhs" of the node. */ |
2743 | ||
2744 | static tree | |
726a989a | 2745 | get_lhs_or_phi_result (gimple stmt) |
e67c25c7 | 2746 | { |
726a989a RB |
2747 | if (gimple_code (stmt) == GIMPLE_PHI) |
2748 | return gimple_phi_result (stmt); | |
2749 | else if (is_gimple_assign (stmt)) | |
2750 | return gimple_assign_lhs (stmt); | |
2751 | else | |
2752 | gcc_unreachable (); | |
e67c25c7 JL |
2753 | } |
2754 | ||
2755 | /* Propagate RHS into all uses of LHS (when possible). | |
2756 | ||
2757 | RHS and LHS are derived from STMT, which is passed in solely so | |
2758 | that we can remove it if propagation is successful. | |
2759 | ||
2760 | When propagating into a PHI node or into a statement which turns | |
2761 | into a trivial copy or constant initialization, set the | |
2762 | appropriate bit in INTERESTING_NAMEs so that we will visit those | |
2763 | nodes as well in an effort to pick up secondary optimization | |
2764 | opportunities. */ | |
2765 | ||
b8698a0f | 2766 | static void |
726a989a | 2767 | propagate_rhs_into_lhs (gimple stmt, tree lhs, tree rhs, bitmap interesting_names) |
e67c25c7 | 2768 | { |
a59d8e8e | 2769 | /* First verify that propagation is valid. */ |
406bfdd3 | 2770 | if (may_propagate_copy (lhs, rhs)) |
e67c25c7 JL |
2771 | { |
2772 | use_operand_p use_p; | |
2773 | imm_use_iterator iter; | |
726a989a | 2774 | gimple use_stmt; |
e67c25c7 JL |
2775 | bool all = true; |
2776 | ||
2777 | /* Dump details. */ | |
2778 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2779 | { | |
2780 | fprintf (dump_file, " Replacing '"); | |
2781 | print_generic_expr (dump_file, lhs, dump_flags); | |
2782 | fprintf (dump_file, "' with %s '", | |
2783 | (TREE_CODE (rhs) != SSA_NAME ? "constant" : "variable")); | |
2784 | print_generic_expr (dump_file, rhs, dump_flags); | |
2785 | fprintf (dump_file, "'\n"); | |
2786 | } | |
2787 | ||
b8698a0f | 2788 | /* Walk over every use of LHS and try to replace the use with RHS. |
e67c25c7 JL |
2789 | At this point the only reason why such a propagation would not |
2790 | be successful would be if the use occurs in an ASM_EXPR. */ | |
6c00f606 | 2791 | FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs) |
e67c25c7 | 2792 | { |
b5b8b0ac AO |
2793 | /* Leave debug stmts alone. If we succeed in propagating |
2794 | all non-debug uses, we'll drop the DEF, and propagation | |
2795 | into debug stmts will occur then. */ | |
2796 | if (gimple_debug_bind_p (use_stmt)) | |
2797 | continue; | |
b8698a0f | 2798 | |
e67c25c7 | 2799 | /* It's not always safe to propagate into an ASM_EXPR. */ |
726a989a RB |
2800 | if (gimple_code (use_stmt) == GIMPLE_ASM |
2801 | && ! may_propagate_copy_into_asm (lhs)) | |
e67c25c7 JL |
2802 | { |
2803 | all = false; | |
2804 | continue; | |
2805 | } | |
2806 | ||
720151ca RG |
2807 | /* It's not ok to propagate into the definition stmt of RHS. |
2808 | <bb 9>: | |
2809 | # prephitmp.12_36 = PHI <g_67.1_6(9)> | |
2810 | g_67.1_6 = prephitmp.12_36; | |
2811 | goto <bb 9>; | |
2812 | While this is strictly all dead code we do not want to | |
2813 | deal with this here. */ | |
2814 | if (TREE_CODE (rhs) == SSA_NAME | |
2815 | && SSA_NAME_DEF_STMT (rhs) == use_stmt) | |
2816 | { | |
2817 | all = false; | |
2818 | continue; | |
2819 | } | |
2820 | ||
e67c25c7 JL |
2821 | /* Dump details. */ |
2822 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2823 | { | |
2824 | fprintf (dump_file, " Original statement:"); | |
726a989a | 2825 | print_gimple_stmt (dump_file, use_stmt, 0, dump_flags); |
e67c25c7 JL |
2826 | } |
2827 | ||
cbc75e62 | 2828 | /* Propagate the RHS into this use of the LHS. */ |
6c00f606 AM |
2829 | FOR_EACH_IMM_USE_ON_STMT (use_p, iter) |
2830 | propagate_value (use_p, rhs); | |
cbc75e62 JL |
2831 | |
2832 | /* Special cases to avoid useless calls into the folding | |
2833 | routines, operand scanning, etc. | |
2834 | ||
6b4a85ad | 2835 | Propagation into a PHI may cause the PHI to become |
cbc75e62 | 2836 | a degenerate, so mark the PHI as interesting. No other |
6b4a85ad RG |
2837 | actions are necessary. */ |
2838 | if (gimple_code (use_stmt) == GIMPLE_PHI) | |
cbc75e62 | 2839 | { |
6b4a85ad RG |
2840 | tree result; |
2841 | ||
cbc75e62 JL |
2842 | /* Dump details. */ |
2843 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2844 | { | |
2845 | fprintf (dump_file, " Updated statement:"); | |
726a989a | 2846 | print_gimple_stmt (dump_file, use_stmt, 0, dump_flags); |
cbc75e62 JL |
2847 | } |
2848 | ||
6b4a85ad RG |
2849 | result = get_lhs_or_phi_result (use_stmt); |
2850 | bitmap_set_bit (interesting_names, SSA_NAME_VERSION (result)); | |
cbc75e62 JL |
2851 | continue; |
2852 | } | |
2853 | ||
b8698a0f | 2854 | /* From this point onward we are propagating into a |
cbc75e62 JL |
2855 | real statement. Folding may (or may not) be possible, |
2856 | we may expose new operands, expose dead EH edges, | |
2857 | etc. */ | |
726a989a RB |
2858 | /* NOTE tuples. In the tuples world, fold_stmt_inplace |
2859 | cannot fold a call that simplifies to a constant, | |
2860 | because the GIMPLE_CALL must be replaced by a | |
2861 | GIMPLE_ASSIGN, and there is no way to effect such a | |
2862 | transformation in-place. We might want to consider | |
2863 | using the more general fold_stmt here. */ | |
59401b92 RG |
2864 | { |
2865 | gimple_stmt_iterator gsi = gsi_for_stmt (use_stmt); | |
2866 | fold_stmt_inplace (&gsi); | |
2867 | } | |
3ae194cd JL |
2868 | |
2869 | /* Sometimes propagation can expose new operands to the | |
cff4e50d PB |
2870 | renamer. */ |
2871 | update_stmt (use_stmt); | |
e67c25c7 JL |
2872 | |
2873 | /* Dump details. */ | |
2874 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2875 | { | |
2876 | fprintf (dump_file, " Updated statement:"); | |
726a989a | 2877 | print_gimple_stmt (dump_file, use_stmt, 0, dump_flags); |
e67c25c7 JL |
2878 | } |
2879 | ||
e67c25c7 JL |
2880 | /* If we replaced a variable index with a constant, then |
2881 | we would need to update the invariant flag for ADDR_EXPRs. */ | |
726a989a RB |
2882 | if (gimple_assign_single_p (use_stmt) |
2883 | && TREE_CODE (gimple_assign_rhs1 (use_stmt)) == ADDR_EXPR) | |
07beea0d | 2884 | recompute_tree_invariant_for_addr_expr |
726a989a | 2885 | (gimple_assign_rhs1 (use_stmt)); |
e67c25c7 JL |
2886 | |
2887 | /* If we cleaned up EH information from the statement, | |
72922229 | 2888 | mark its containing block as needing EH cleanups. */ |
e67c25c7 | 2889 | if (maybe_clean_or_replace_eh_stmt (use_stmt, use_stmt)) |
72922229 | 2890 | { |
726a989a | 2891 | bitmap_set_bit (need_eh_cleanup, gimple_bb (use_stmt)->index); |
72922229 JL |
2892 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2893 | fprintf (dump_file, " Flagged to clear EH edges.\n"); | |
2894 | } | |
e67c25c7 | 2895 | |
cbc75e62 JL |
2896 | /* Propagation may expose new trivial copy/constant propagation |
2897 | opportunities. */ | |
726a989a RB |
2898 | if (gimple_assign_single_p (use_stmt) |
2899 | && TREE_CODE (gimple_assign_lhs (use_stmt)) == SSA_NAME | |
2900 | && (TREE_CODE (gimple_assign_rhs1 (use_stmt)) == SSA_NAME | |
2901 | || is_gimple_min_invariant (gimple_assign_rhs1 (use_stmt)))) | |
2902 | { | |
e67c25c7 JL |
2903 | tree result = get_lhs_or_phi_result (use_stmt); |
2904 | bitmap_set_bit (interesting_names, SSA_NAME_VERSION (result)); | |
2905 | } | |
2906 | ||
2907 | /* Propagation into these nodes may make certain edges in | |
2908 | the CFG unexecutable. We want to identify them as PHI nodes | |
2909 | at the destination of those unexecutable edges may become | |
2910 | degenerates. */ | |
726a989a RB |
2911 | else if (gimple_code (use_stmt) == GIMPLE_COND |
2912 | || gimple_code (use_stmt) == GIMPLE_SWITCH | |
2913 | || gimple_code (use_stmt) == GIMPLE_GOTO) | |
2914 | { | |
e67c25c7 JL |
2915 | tree val; |
2916 | ||
726a989a | 2917 | if (gimple_code (use_stmt) == GIMPLE_COND) |
db3927fb AH |
2918 | val = fold_binary_loc (gimple_location (use_stmt), |
2919 | gimple_cond_code (use_stmt), | |
726a989a RB |
2920 | boolean_type_node, |
2921 | gimple_cond_lhs (use_stmt), | |
2922 | gimple_cond_rhs (use_stmt)); | |
2923 | else if (gimple_code (use_stmt) == GIMPLE_SWITCH) | |
538dd0b7 | 2924 | val = gimple_switch_index (as_a <gswitch *> (use_stmt)); |
e67c25c7 | 2925 | else |
726a989a | 2926 | val = gimple_goto_dest (use_stmt); |
e67c25c7 | 2927 | |
726a989a | 2928 | if (val && is_gimple_min_invariant (val)) |
e67c25c7 | 2929 | { |
726a989a | 2930 | basic_block bb = gimple_bb (use_stmt); |
e67c25c7 JL |
2931 | edge te = find_taken_edge (bb, val); |
2932 | edge_iterator ei; | |
2933 | edge e; | |
538dd0b7 DM |
2934 | gimple_stmt_iterator gsi; |
2935 | gphi_iterator psi; | |
e67c25c7 JL |
2936 | |
2937 | /* Remove all outgoing edges except TE. */ | |
2938 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei));) | |
2939 | { | |
2940 | if (e != te) | |
2941 | { | |
e67c25c7 JL |
2942 | /* Mark all the PHI nodes at the destination of |
2943 | the unexecutable edge as interesting. */ | |
726a989a RB |
2944 | for (psi = gsi_start_phis (e->dest); |
2945 | !gsi_end_p (psi); | |
2946 | gsi_next (&psi)) | |
2947 | { | |
538dd0b7 | 2948 | gphi *phi = psi.phi (); |
726a989a RB |
2949 | |
2950 | tree result = gimple_phi_result (phi); | |
e67c25c7 JL |
2951 | int version = SSA_NAME_VERSION (result); |
2952 | ||
2953 | bitmap_set_bit (interesting_names, version); | |
2954 | } | |
2955 | ||
2956 | te->probability += e->probability; | |
2957 | ||
2958 | te->count += e->count; | |
2959 | remove_edge (e); | |
8d9d6561 | 2960 | cfg_altered = true; |
e67c25c7 JL |
2961 | } |
2962 | else | |
2963 | ei_next (&ei); | |
2964 | } | |
2965 | ||
726a989a RB |
2966 | gsi = gsi_last_bb (gimple_bb (use_stmt)); |
2967 | gsi_remove (&gsi, true); | |
e67c25c7 JL |
2968 | |
2969 | /* And fixup the flags on the single remaining edge. */ | |
2970 | te->flags &= ~(EDGE_TRUE_VALUE | EDGE_FALSE_VALUE); | |
2971 | te->flags &= ~EDGE_ABNORMAL; | |
2972 | te->flags |= EDGE_FALLTHRU; | |
2973 | if (te->probability > REG_BR_PROB_BASE) | |
2974 | te->probability = REG_BR_PROB_BASE; | |
2975 | } | |
2976 | } | |
2977 | } | |
2978 | ||
b8698a0f | 2979 | /* Ensure there is nothing else to do. */ |
a5f84464 | 2980 | gcc_assert (!all || has_zero_uses (lhs)); |
243cc836 | 2981 | |
e67c25c7 JL |
2982 | /* If we were able to propagate away all uses of LHS, then |
2983 | we can remove STMT. */ | |
2984 | if (all) | |
2985 | remove_stmt_or_phi (stmt); | |
2986 | } | |
2987 | } | |
2988 | ||
726a989a | 2989 | /* STMT is either a PHI node (potentially a degenerate PHI node) or |
e67c25c7 JL |
2990 | a statement that is a trivial copy or constant initialization. |
2991 | ||
2992 | Attempt to eliminate T by propagating its RHS into all uses of | |
2993 | its LHS. This may in turn set new bits in INTERESTING_NAMES | |
2994 | for nodes we want to revisit later. | |
2995 | ||
2996 | All exit paths should clear INTERESTING_NAMES for the result | |
726a989a | 2997 | of STMT. */ |
e67c25c7 JL |
2998 | |
2999 | static void | |
726a989a | 3000 | eliminate_const_or_copy (gimple stmt, bitmap interesting_names) |
e67c25c7 | 3001 | { |
726a989a | 3002 | tree lhs = get_lhs_or_phi_result (stmt); |
e67c25c7 JL |
3003 | tree rhs; |
3004 | int version = SSA_NAME_VERSION (lhs); | |
3005 | ||
3006 | /* If the LHS of this statement or PHI has no uses, then we can | |
3007 | just eliminate it. This can occur if, for example, the PHI | |
3008 | was created by block duplication due to threading and its only | |
3009 | use was in the conditional at the end of the block which was | |
3010 | deleted. */ | |
3011 | if (has_zero_uses (lhs)) | |
3012 | { | |
3013 | bitmap_clear_bit (interesting_names, version); | |
726a989a | 3014 | remove_stmt_or_phi (stmt); |
e67c25c7 JL |
3015 | return; |
3016 | } | |
3017 | ||
3018 | /* Get the RHS of the assignment or PHI node if the PHI is a | |
3019 | degenerate. */ | |
726a989a | 3020 | rhs = get_rhs_or_phi_arg (stmt); |
e67c25c7 JL |
3021 | if (!rhs) |
3022 | { | |
3023 | bitmap_clear_bit (interesting_names, version); | |
3024 | return; | |
3025 | } | |
3026 | ||
bd388c2a RB |
3027 | if (!virtual_operand_p (lhs)) |
3028 | propagate_rhs_into_lhs (stmt, lhs, rhs, interesting_names); | |
3029 | else | |
3030 | { | |
3031 | gimple use_stmt; | |
3032 | imm_use_iterator iter; | |
3033 | use_operand_p use_p; | |
3034 | /* For virtual operands we have to propagate into all uses as | |
3035 | otherwise we will create overlapping life-ranges. */ | |
3036 | FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs) | |
3037 | FOR_EACH_IMM_USE_ON_STMT (use_p, iter) | |
3038 | SET_USE (use_p, rhs); | |
3039 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
3040 | SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs) = 1; | |
3041 | remove_stmt_or_phi (stmt); | |
3042 | } | |
e67c25c7 | 3043 | |
726a989a | 3044 | /* Note that STMT may well have been deleted by now, so do |
e67c25c7 JL |
3045 | not access it, instead use the saved version # to clear |
3046 | T's entry in the worklist. */ | |
3047 | bitmap_clear_bit (interesting_names, version); | |
3048 | } | |
3049 | ||
3050 | /* The first phase in degenerate PHI elimination. | |
3051 | ||
3052 | Eliminate the degenerate PHIs in BB, then recurse on the | |
3053 | dominator children of BB. */ | |
3054 | ||
3055 | static void | |
3056 | eliminate_degenerate_phis_1 (basic_block bb, bitmap interesting_names) | |
3057 | { | |
538dd0b7 | 3058 | gphi_iterator gsi; |
e67c25c7 JL |
3059 | basic_block son; |
3060 | ||
726a989a | 3061 | for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
e67c25c7 | 3062 | { |
538dd0b7 | 3063 | gphi *phi = gsi.phi (); |
726a989a | 3064 | |
e67c25c7 JL |
3065 | eliminate_const_or_copy (phi, interesting_names); |
3066 | } | |
3067 | ||
3068 | /* Recurse into the dominator children of BB. */ | |
3069 | for (son = first_dom_son (CDI_DOMINATORS, bb); | |
3070 | son; | |
3071 | son = next_dom_son (CDI_DOMINATORS, son)) | |
3072 | eliminate_degenerate_phis_1 (son, interesting_names); | |
3073 | } | |
3074 | ||
3075 | ||
3076 | /* A very simple pass to eliminate degenerate PHI nodes from the | |
3077 | IL. This is meant to be fast enough to be able to be run several | |
3078 | times in the optimization pipeline. | |
3079 | ||
3080 | Certain optimizations, particularly those which duplicate blocks | |
3081 | or remove edges from the CFG can create or expose PHIs which are | |
3082 | trivial copies or constant initializations. | |
3083 | ||
3084 | While we could pick up these optimizations in DOM or with the | |
3085 | combination of copy-prop and CCP, those solutions are far too | |
3086 | heavy-weight for our needs. | |
3087 | ||
3088 | This implementation has two phases so that we can efficiently | |
3089 | eliminate the first order degenerate PHIs and second order | |
3090 | degenerate PHIs. | |
3091 | ||
3092 | The first phase performs a dominator walk to identify and eliminate | |
3093 | the vast majority of the degenerate PHIs. When a degenerate PHI | |
3094 | is identified and eliminated any affected statements or PHIs | |
3095 | are put on a worklist. | |
3096 | ||
3097 | The second phase eliminates degenerate PHIs and trivial copies | |
3098 | or constant initializations using the worklist. This is how we | |
3099 | pick up the secondary optimization opportunities with minimal | |
3100 | cost. */ | |
3101 | ||
be55bfe6 TS |
3102 | namespace { |
3103 | ||
3104 | const pass_data pass_data_phi_only_cprop = | |
3105 | { | |
3106 | GIMPLE_PASS, /* type */ | |
3107 | "phicprop", /* name */ | |
3108 | OPTGROUP_NONE, /* optinfo_flags */ | |
be55bfe6 TS |
3109 | TV_TREE_PHI_CPROP, /* tv_id */ |
3110 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
3111 | 0, /* properties_provided */ | |
3112 | 0, /* properties_destroyed */ | |
3113 | 0, /* todo_flags_start */ | |
3bea341f | 3114 | ( TODO_cleanup_cfg | TODO_update_ssa ), /* todo_flags_finish */ |
be55bfe6 TS |
3115 | }; |
3116 | ||
3117 | class pass_phi_only_cprop : public gimple_opt_pass | |
3118 | { | |
3119 | public: | |
3120 | pass_phi_only_cprop (gcc::context *ctxt) | |
3121 | : gimple_opt_pass (pass_data_phi_only_cprop, ctxt) | |
3122 | {} | |
3123 | ||
3124 | /* opt_pass methods: */ | |
3125 | opt_pass * clone () { return new pass_phi_only_cprop (m_ctxt); } | |
3126 | virtual bool gate (function *) { return flag_tree_dom != 0; } | |
3127 | virtual unsigned int execute (function *); | |
3128 | ||
3129 | }; // class pass_phi_only_cprop | |
3130 | ||
3131 | unsigned int | |
3132 | pass_phi_only_cprop::execute (function *fun) | |
e67c25c7 JL |
3133 | { |
3134 | bitmap interesting_names; | |
1f70491b | 3135 | bitmap interesting_names1; |
e67c25c7 | 3136 | |
72922229 JL |
3137 | /* Bitmap of blocks which need EH information updated. We can not |
3138 | update it on-the-fly as doing so invalidates the dominator tree. */ | |
3139 | need_eh_cleanup = BITMAP_ALLOC (NULL); | |
3140 | ||
e67c25c7 JL |
3141 | /* INTERESTING_NAMES is effectively our worklist, indexed by |
3142 | SSA_NAME_VERSION. | |
3143 | ||
3144 | A set bit indicates that the statement or PHI node which | |
3145 | defines the SSA_NAME should be (re)examined to determine if | |
66a4ad37 | 3146 | it has become a degenerate PHI or trivial const/copy propagation |
b8698a0f | 3147 | opportunity. |
e67c25c7 JL |
3148 | |
3149 | Experiments have show we generally get better compilation | |
3150 | time behavior with bitmaps rather than sbitmaps. */ | |
3151 | interesting_names = BITMAP_ALLOC (NULL); | |
1f70491b | 3152 | interesting_names1 = BITMAP_ALLOC (NULL); |
e67c25c7 | 3153 | |
8d9d6561 EB |
3154 | calculate_dominance_info (CDI_DOMINATORS); |
3155 | cfg_altered = false; | |
3156 | ||
917f1b7e | 3157 | /* First phase. Eliminate degenerate PHIs via a dominator |
e67c25c7 JL |
3158 | walk of the CFG. |
3159 | ||
3160 | Experiments have indicated that we generally get better | |
3161 | compile-time behavior by visiting blocks in the first | |
3162 | phase in dominator order. Presumably this is because walking | |
3163 | in dominator order leaves fewer PHIs for later examination | |
3164 | by the worklist phase. */ | |
be55bfe6 | 3165 | eliminate_degenerate_phis_1 (ENTRY_BLOCK_PTR_FOR_FN (fun), |
fefa31b5 | 3166 | interesting_names); |
e67c25c7 | 3167 | |
917f1b7e | 3168 | /* Second phase. Eliminate second order degenerate PHIs as well |
e67c25c7 JL |
3169 | as trivial copies or constant initializations identified by |
3170 | the first phase or this phase. Basically we keep iterating | |
3171 | until our set of INTERESTING_NAMEs is empty. */ | |
3172 | while (!bitmap_empty_p (interesting_names)) | |
3173 | { | |
3174 | unsigned int i; | |
3175 | bitmap_iterator bi; | |
3176 | ||
1f70491b AP |
3177 | /* EXECUTE_IF_SET_IN_BITMAP does not like its bitmap |
3178 | changed during the loop. Copy it to another bitmap and | |
3179 | use that. */ | |
3180 | bitmap_copy (interesting_names1, interesting_names); | |
3181 | ||
3182 | EXECUTE_IF_SET_IN_BITMAP (interesting_names1, 0, i, bi) | |
e67c25c7 JL |
3183 | { |
3184 | tree name = ssa_name (i); | |
3185 | ||
3186 | /* Ignore SSA_NAMEs that have been released because | |
3187 | their defining statement was deleted (unreachable). */ | |
3188 | if (name) | |
3189 | eliminate_const_or_copy (SSA_NAME_DEF_STMT (ssa_name (i)), | |
3190 | interesting_names); | |
3191 | } | |
3192 | } | |
72922229 | 3193 | |
8d9d6561 | 3194 | if (cfg_altered) |
83ba4d6f RB |
3195 | { |
3196 | free_dominance_info (CDI_DOMINATORS); | |
3197 | /* If we changed the CFG schedule loops for fixup by cfgcleanup. */ | |
726338f4 | 3198 | loops_state_set (LOOPS_NEED_FIXUP); |
83ba4d6f | 3199 | } |
8d9d6561 | 3200 | |
72922229 JL |
3201 | /* Propagation of const and copies may make some EH edges dead. Purge |
3202 | such edges from the CFG as needed. */ | |
3203 | if (!bitmap_empty_p (need_eh_cleanup)) | |
3204 | { | |
726a989a | 3205 | gimple_purge_all_dead_eh_edges (need_eh_cleanup); |
72922229 JL |
3206 | BITMAP_FREE (need_eh_cleanup); |
3207 | } | |
e67c25c7 JL |
3208 | |
3209 | BITMAP_FREE (interesting_names); | |
1f70491b | 3210 | BITMAP_FREE (interesting_names1); |
e67c25c7 JL |
3211 | return 0; |
3212 | } | |
3213 | ||
27a4cd48 DM |
3214 | } // anon namespace |
3215 | ||
3216 | gimple_opt_pass * | |
3217 | make_pass_phi_only_cprop (gcc::context *ctxt) | |
3218 | { | |
3219 | return new pass_phi_only_cprop (ctxt); | |
3220 | } |