]>
Commit | Line | Data |
---|---|---|
4ee9c684 | 1 | /* Optimization of PHI nodes by converting them into straightline code. |
d353bf18 | 2 | Copyright (C) 2004-2015 Free Software Foundation, Inc. |
4ee9c684 | 3 | |
4 | This file is part of GCC. | |
20e5647c | 5 | |
4ee9c684 | 6 | GCC is free software; you can redistribute it and/or modify it |
7 | under the terms of the GNU General Public License as published by the | |
8c4c00c1 | 8 | Free Software Foundation; either version 3, or (at your option) any |
4ee9c684 | 9 | later version. |
20e5647c | 10 | |
4ee9c684 | 11 | GCC is distributed in the hope that it will be useful, but WITHOUT |
12 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
13 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
14 | for more details. | |
20e5647c | 15 | |
4ee9c684 | 16 | You should have received a copy of the GNU General Public License |
8c4c00c1 | 17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ | |
4ee9c684 | 19 | |
20 | #include "config.h" | |
21 | #include "system.h" | |
22 | #include "coretypes.h" | |
9ef16211 | 23 | #include "backend.h" |
d040a5b0 | 24 | #include "cfghooks.h" |
4ee9c684 | 25 | #include "tree.h" |
9ef16211 | 26 | #include "gimple.h" |
27 | #include "rtl.h" | |
28 | #include "ssa.h" | |
29 | #include "alias.h" | |
b20a8bb4 | 30 | #include "fold-const.h" |
9ed99284 | 31 | #include "stor-layout.h" |
0beac6fc | 32 | #include "flags.h" |
4ee9c684 | 33 | #include "tm_p.h" |
94ea8568 | 34 | #include "cfganal.h" |
bc61cadb | 35 | #include "internal-fn.h" |
a8783bee | 36 | #include "gimplify.h" |
dcf1a1ec | 37 | #include "gimple-iterator.h" |
e795d6e1 | 38 | #include "gimplify-me.h" |
073c1fd5 | 39 | #include "tree-cfg.h" |
d53441c8 | 40 | #include "insn-config.h" |
073c1fd5 | 41 | #include "tree-dfa.h" |
4ee9c684 | 42 | #include "tree-pass.h" |
4ee9c684 | 43 | #include "langhooks.h" |
e6d0e152 | 44 | #include "domwalk.h" |
ec611e12 | 45 | #include "cfgloop.h" |
46 | #include "tree-data-ref.h" | |
239e9670 | 47 | #include "gimple-pretty-print.h" |
34517c64 | 48 | #include "insn-codes.h" |
947ed59a | 49 | #include "optabs-tree.h" |
f6568ea4 | 50 | #include "tree-scalar-evolution.h" |
b6814ca0 | 51 | #include "tree-inline.h" |
0d8001a7 | 52 | #include "params.h" |
239e9670 | 53 | |
239e9670 | 54 | static unsigned int tree_ssa_phiopt_worker (bool, bool); |
a4844041 | 55 | static bool conditional_replacement (basic_block, basic_block, |
1a91d914 | 56 | edge, edge, gphi *, tree, tree); |
29a78fec | 57 | static bool factor_out_conditional_conversion (edge, edge, gphi *, tree, tree); |
fb9912ea | 58 | static int value_replacement (basic_block, basic_block, |
42acab1c | 59 | edge, edge, gimple *, tree, tree); |
a4844041 | 60 | static bool minmax_replacement (basic_block, basic_block, |
42acab1c | 61 | edge, edge, gimple *, tree, tree); |
a4844041 | 62 | static bool abs_replacement (basic_block, basic_block, |
42acab1c | 63 | edge, edge, gimple *, tree, tree); |
e6d0e152 | 64 | static bool cond_store_replacement (basic_block, basic_block, edge, edge, |
431205b7 | 65 | hash_set<tree> *); |
91cf53d5 | 66 | static bool cond_if_else_store_replacement (basic_block, basic_block, basic_block); |
431205b7 | 67 | static hash_set<tree> * get_non_trapping (); |
42acab1c | 68 | static void replace_phi_edge_with_variable (basic_block, edge, gimple *, tree); |
239e9670 | 69 | static void hoist_adjacent_loads (basic_block, basic_block, |
70 | basic_block, basic_block); | |
71 | static bool gate_hoist_loads (void); | |
902929aa | 72 | |
e6d0e152 | 73 | /* This pass tries to transform conditional stores into unconditional |
74 | ones, enabling further simplifications with the simpler then and else | |
75 | blocks. In particular it replaces this: | |
76 | ||
77 | bb0: | |
78 | if (cond) goto bb2; else goto bb1; | |
79 | bb1: | |
91cf53d5 | 80 | *p = RHS; |
e6d0e152 | 81 | bb2: |
82 | ||
83 | with | |
84 | ||
85 | bb0: | |
86 | if (cond) goto bb1; else goto bb2; | |
87 | bb1: | |
88 | condtmp' = *p; | |
89 | bb2: | |
90 | condtmp = PHI <RHS, condtmp'> | |
91cf53d5 | 91 | *p = condtmp; |
e6d0e152 | 92 | |
93 | This transformation can only be done under several constraints, | |
91cf53d5 | 94 | documented below. It also replaces: |
95 | ||
96 | bb0: | |
97 | if (cond) goto bb2; else goto bb1; | |
98 | bb1: | |
99 | *p = RHS1; | |
100 | goto bb3; | |
101 | bb2: | |
102 | *p = RHS2; | |
103 | bb3: | |
104 | ||
105 | with | |
106 | ||
107 | bb0: | |
108 | if (cond) goto bb3; else goto bb1; | |
109 | bb1: | |
110 | bb3: | |
111 | condtmp = PHI <RHS1, RHS2> | |
112 | *p = condtmp; */ | |
e6d0e152 | 113 | |
114 | static unsigned int | |
115 | tree_ssa_cs_elim (void) | |
116 | { | |
f6568ea4 | 117 | unsigned todo; |
118 | /* ??? We are not interested in loop related info, but the following | |
119 | will create it, ICEing as we didn't init loops with pre-headers. | |
120 | An interfacing issue of find_data_references_in_bb. */ | |
121 | loop_optimizer_init (LOOPS_NORMAL); | |
122 | scev_initialize (); | |
123 | todo = tree_ssa_phiopt_worker (true, false); | |
124 | scev_finalize (); | |
125 | loop_optimizer_finalize (); | |
126 | return todo; | |
e6d0e152 | 127 | } |
128 | ||
c3597b05 | 129 | /* Return the singleton PHI in the SEQ of PHIs for edges E0 and E1. */ |
130 | ||
1a91d914 | 131 | static gphi * |
c3597b05 | 132 | single_non_singleton_phi_for_edges (gimple_seq seq, edge e0, edge e1) |
133 | { | |
134 | gimple_stmt_iterator i; | |
1a91d914 | 135 | gphi *phi = NULL; |
c3597b05 | 136 | if (gimple_seq_singleton_p (seq)) |
1a91d914 | 137 | return as_a <gphi *> (gsi_stmt (gsi_start (seq))); |
c3597b05 | 138 | for (i = gsi_start (seq); !gsi_end_p (i); gsi_next (&i)) |
139 | { | |
1a91d914 | 140 | gphi *p = as_a <gphi *> (gsi_stmt (i)); |
c3597b05 | 141 | /* If the PHI arguments are equal then we can skip this PHI. */ |
142 | if (operand_equal_for_phi_arg_p (gimple_phi_arg_def (p, e0->dest_idx), | |
143 | gimple_phi_arg_def (p, e1->dest_idx))) | |
144 | continue; | |
145 | ||
146 | /* If we already have a PHI that has the two edge arguments are | |
147 | different, then return it is not a singleton for these PHIs. */ | |
148 | if (phi) | |
149 | return NULL; | |
150 | ||
151 | phi = p; | |
152 | } | |
153 | return phi; | |
154 | } | |
155 | ||
e6d0e152 | 156 | /* The core routine of conditional store replacement and normal |
157 | phi optimizations. Both share much of the infrastructure in how | |
158 | to match applicable basic block patterns. DO_STORE_ELIM is true | |
239e9670 | 159 | when we want to do conditional store replacement, false otherwise. |
f32420fb | 160 | DO_HOIST_LOADS is true when we want to hoist adjacent loads out |
239e9670 | 161 | of diamond control flow patterns, false otherwise. */ |
e6d0e152 | 162 | static unsigned int |
239e9670 | 163 | tree_ssa_phiopt_worker (bool do_store_elim, bool do_hoist_loads) |
4ee9c684 | 164 | { |
165 | basic_block bb; | |
194899bf | 166 | basic_block *bb_order; |
167 | unsigned n, i; | |
1e4b21e3 | 168 | bool cfgchanged = false; |
431205b7 | 169 | hash_set<tree> *nontrap = 0; |
e6d0e152 | 170 | |
171 | if (do_store_elim) | |
03d37e4e | 172 | /* Calculate the set of non-trapping memory accesses. */ |
173 | nontrap = get_non_trapping (); | |
194899bf | 174 | |
175 | /* Search every basic block for COND_EXPR we may be able to optimize. | |
176 | ||
177 | We walk the blocks in order that guarantees that a block with | |
178 | a single predecessor is processed before the predecessor. | |
179 | This ensures that we collapse inner ifs before visiting the | |
180 | outer ones, and also that we do not try to visit a removed | |
181 | block. */ | |
ba4d2b2f | 182 | bb_order = single_pred_before_succ_order (); |
a28770e1 | 183 | n = n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS; |
4ee9c684 | 184 | |
48e1416a | 185 | for (i = 0; i < n; i++) |
4ee9c684 | 186 | { |
42acab1c | 187 | gimple *cond_stmt; |
1a91d914 | 188 | gphi *phi; |
33784d89 | 189 | basic_block bb1, bb2; |
190 | edge e1, e2; | |
194899bf | 191 | tree arg0, arg1; |
192 | ||
193 | bb = bb_order[i]; | |
20e5647c | 194 | |
75a70cf9 | 195 | cond_stmt = last_stmt (bb); |
196 | /* Check to see if the last statement is a GIMPLE_COND. */ | |
197 | if (!cond_stmt | |
198 | || gimple_code (cond_stmt) != GIMPLE_COND) | |
33784d89 | 199 | continue; |
20e5647c | 200 | |
33784d89 | 201 | e1 = EDGE_SUCC (bb, 0); |
202 | bb1 = e1->dest; | |
203 | e2 = EDGE_SUCC (bb, 1); | |
204 | bb2 = e2->dest; | |
20e5647c | 205 | |
33784d89 | 206 | /* We cannot do the optimization on abnormal edges. */ |
207 | if ((e1->flags & EDGE_ABNORMAL) != 0 | |
208 | || (e2->flags & EDGE_ABNORMAL) != 0) | |
209 | continue; | |
20e5647c | 210 | |
33784d89 | 211 | /* If either bb1's succ or bb2 or bb2's succ is non NULL. */ |
ea091dfd | 212 | if (EDGE_COUNT (bb1->succs) == 0 |
33784d89 | 213 | || bb2 == NULL |
ea091dfd | 214 | || EDGE_COUNT (bb2->succs) == 0) |
33784d89 | 215 | continue; |
20e5647c | 216 | |
33784d89 | 217 | /* Find the bb which is the fall through to the other. */ |
218 | if (EDGE_SUCC (bb1, 0)->dest == bb2) | |
219 | ; | |
220 | else if (EDGE_SUCC (bb2, 0)->dest == bb1) | |
221 | { | |
a4f59596 | 222 | std::swap (bb1, bb2); |
223 | std::swap (e1, e2); | |
33784d89 | 224 | } |
91cf53d5 | 225 | else if (do_store_elim |
226 | && EDGE_SUCC (bb1, 0)->dest == EDGE_SUCC (bb2, 0)->dest) | |
227 | { | |
228 | basic_block bb3 = EDGE_SUCC (bb1, 0)->dest; | |
229 | ||
230 | if (!single_succ_p (bb1) | |
231 | || (EDGE_SUCC (bb1, 0)->flags & EDGE_FALLTHRU) == 0 | |
232 | || !single_succ_p (bb2) | |
233 | || (EDGE_SUCC (bb2, 0)->flags & EDGE_FALLTHRU) == 0 | |
234 | || EDGE_COUNT (bb3->preds) != 2) | |
235 | continue; | |
236 | if (cond_if_else_store_replacement (bb1, bb2, bb3)) | |
237 | cfgchanged = true; | |
238 | continue; | |
239 | } | |
239e9670 | 240 | else if (do_hoist_loads |
241 | && EDGE_SUCC (bb1, 0)->dest == EDGE_SUCC (bb2, 0)->dest) | |
242 | { | |
243 | basic_block bb3 = EDGE_SUCC (bb1, 0)->dest; | |
244 | ||
245 | if (!FLOAT_TYPE_P (TREE_TYPE (gimple_cond_lhs (cond_stmt))) | |
246 | && single_succ_p (bb1) | |
247 | && single_succ_p (bb2) | |
248 | && single_pred_p (bb1) | |
249 | && single_pred_p (bb2) | |
250 | && EDGE_COUNT (bb->succs) == 2 | |
251 | && EDGE_COUNT (bb3->preds) == 2 | |
252 | /* If one edge or the other is dominant, a conditional move | |
253 | is likely to perform worse than the well-predicted branch. */ | |
254 | && !predictable_edge_p (EDGE_SUCC (bb, 0)) | |
255 | && !predictable_edge_p (EDGE_SUCC (bb, 1))) | |
256 | hoist_adjacent_loads (bb, bb1, bb2, bb3); | |
257 | continue; | |
258 | } | |
33784d89 | 259 | else |
f32420fb | 260 | continue; |
20e5647c | 261 | |
33784d89 | 262 | e1 = EDGE_SUCC (bb1, 0); |
20e5647c | 263 | |
33784d89 | 264 | /* Make sure that bb1 is just a fall through. */ |
db5ba14c | 265 | if (!single_succ_p (bb1) |
33784d89 | 266 | || (e1->flags & EDGE_FALLTHRU) == 0) |
267 | continue; | |
20e5647c | 268 | |
3472707f | 269 | /* Also make sure that bb1 only have one predecessor and that it |
270 | is bb. */ | |
ea091dfd | 271 | if (!single_pred_p (bb1) |
272 | || single_pred (bb1) != bb) | |
33784d89 | 273 | continue; |
20e5647c | 274 | |
e6d0e152 | 275 | if (do_store_elim) |
276 | { | |
277 | /* bb1 is the middle block, bb2 the join block, bb the split block, | |
278 | e1 the fallthrough edge from bb1 to bb2. We can't do the | |
279 | optimization if the join block has more than two predecessors. */ | |
280 | if (EDGE_COUNT (bb2->preds) > 2) | |
281 | continue; | |
282 | if (cond_store_replacement (bb1, bb2, e1, e2, nontrap)) | |
283 | cfgchanged = true; | |
284 | } | |
285 | else | |
286 | { | |
75a70cf9 | 287 | gimple_seq phis = phi_nodes (bb2); |
2109076a | 288 | gimple_stmt_iterator gsi; |
fb9912ea | 289 | bool candorest = true; |
c3597b05 | 290 | |
fb9912ea | 291 | /* Value replacement can work with more than one PHI |
292 | so try that first. */ | |
293 | for (gsi = gsi_start (phis); !gsi_end_p (gsi); gsi_next (&gsi)) | |
294 | { | |
1a91d914 | 295 | phi = as_a <gphi *> (gsi_stmt (gsi)); |
fb9912ea | 296 | arg0 = gimple_phi_arg_def (phi, e1->dest_idx); |
297 | arg1 = gimple_phi_arg_def (phi, e2->dest_idx); | |
298 | if (value_replacement (bb, bb1, e1, e2, phi, arg0, arg1) == 2) | |
299 | { | |
300 | candorest = false; | |
301 | cfgchanged = true; | |
302 | break; | |
303 | } | |
304 | } | |
e6d0e152 | 305 | |
fb9912ea | 306 | if (!candorest) |
307 | continue; | |
f32420fb | 308 | |
c3597b05 | 309 | phi = single_non_singleton_phi_for_edges (phis, e1, e2); |
2109076a | 310 | if (!phi) |
e6d0e152 | 311 | continue; |
312 | ||
75a70cf9 | 313 | arg0 = gimple_phi_arg_def (phi, e1->dest_idx); |
314 | arg1 = gimple_phi_arg_def (phi, e2->dest_idx); | |
e6d0e152 | 315 | |
316 | /* Something is wrong if we cannot find the arguments in the PHI | |
317 | node. */ | |
318 | gcc_assert (arg0 != NULL && arg1 != NULL); | |
319 | ||
29a78fec | 320 | if (factor_out_conditional_conversion (e1, e2, phi, arg0, arg1)) |
321 | { | |
322 | /* factor_out_conditional_conversion may create a new PHI in | |
323 | BB2 and eliminate an existing PHI in BB2. Recompute values | |
324 | that may be affected by that change. */ | |
325 | phis = phi_nodes (bb2); | |
326 | phi = single_non_singleton_phi_for_edges (phis, e1, e2); | |
327 | gcc_assert (phi); | |
328 | arg0 = gimple_phi_arg_def (phi, e1->dest_idx); | |
329 | arg1 = gimple_phi_arg_def (phi, e2->dest_idx); | |
330 | gcc_assert (arg0 != NULL && arg1 != NULL); | |
331 | } | |
332 | ||
e6d0e152 | 333 | /* Do the replacement of conditional if it can be done. */ |
334 | if (conditional_replacement (bb, bb1, e1, e2, phi, arg0, arg1)) | |
335 | cfgchanged = true; | |
e6d0e152 | 336 | else if (abs_replacement (bb, bb1, e1, e2, phi, arg0, arg1)) |
337 | cfgchanged = true; | |
338 | else if (minmax_replacement (bb, bb1, e1, e2, phi, arg0, arg1)) | |
339 | cfgchanged = true; | |
340 | } | |
194899bf | 341 | } |
342 | ||
343 | free (bb_order); | |
48e1416a | 344 | |
e6d0e152 | 345 | if (do_store_elim) |
431205b7 | 346 | delete nontrap; |
e6d0e152 | 347 | /* If the CFG has changed, we should cleanup the CFG. */ |
348 | if (cfgchanged && do_store_elim) | |
349 | { | |
350 | /* In cond-store replacement we have added some loads on edges | |
351 | and new VOPS (as we moved the store, and created a load). */ | |
75a70cf9 | 352 | gsi_commit_edge_inserts (); |
e6d0e152 | 353 | return TODO_cleanup_cfg | TODO_update_ssa_only_virtuals; |
354 | } | |
355 | else if (cfgchanged) | |
356 | return TODO_cleanup_cfg; | |
357 | return 0; | |
194899bf | 358 | } |
359 | ||
fccee353 | 360 | /* Replace PHI node element whose edge is E in block BB with variable NEW. |
33784d89 | 361 | Remove the edge from COND_BLOCK which does not lead to BB (COND_BLOCK |
902929aa | 362 | is known to have two edges, one of which must reach BB). */ |
363 | ||
364 | static void | |
a4844041 | 365 | replace_phi_edge_with_variable (basic_block cond_block, |
42acab1c | 366 | edge e, gimple *phi, tree new_tree) |
902929aa | 367 | { |
75a70cf9 | 368 | basic_block bb = gimple_bb (phi); |
0e1a77e1 | 369 | basic_block block_to_remove; |
75a70cf9 | 370 | gimple_stmt_iterator gsi; |
33784d89 | 371 | |
20e5647c | 372 | /* Change the PHI argument to new. */ |
f0d6e81c | 373 | SET_USE (PHI_ARG_DEF_PTR (phi, e->dest_idx), new_tree); |
0e1a77e1 | 374 | |
0e1a77e1 | 375 | /* Remove the empty basic block. */ |
cd665a06 | 376 | if (EDGE_SUCC (cond_block, 0)->dest == bb) |
902929aa | 377 | { |
cd665a06 | 378 | EDGE_SUCC (cond_block, 0)->flags |= EDGE_FALLTHRU; |
379 | EDGE_SUCC (cond_block, 0)->flags &= ~(EDGE_TRUE_VALUE | EDGE_FALSE_VALUE); | |
81c5be57 | 380 | EDGE_SUCC (cond_block, 0)->probability = REG_BR_PROB_BASE; |
381 | EDGE_SUCC (cond_block, 0)->count += EDGE_SUCC (cond_block, 1)->count; | |
0e1a77e1 | 382 | |
cd665a06 | 383 | block_to_remove = EDGE_SUCC (cond_block, 1)->dest; |
902929aa | 384 | } |
385 | else | |
386 | { | |
cd665a06 | 387 | EDGE_SUCC (cond_block, 1)->flags |= EDGE_FALLTHRU; |
388 | EDGE_SUCC (cond_block, 1)->flags | |
902929aa | 389 | &= ~(EDGE_TRUE_VALUE | EDGE_FALSE_VALUE); |
81c5be57 | 390 | EDGE_SUCC (cond_block, 1)->probability = REG_BR_PROB_BASE; |
391 | EDGE_SUCC (cond_block, 1)->count += EDGE_SUCC (cond_block, 0)->count; | |
0e1a77e1 | 392 | |
cd665a06 | 393 | block_to_remove = EDGE_SUCC (cond_block, 0)->dest; |
902929aa | 394 | } |
0e1a77e1 | 395 | delete_basic_block (block_to_remove); |
20e5647c | 396 | |
902929aa | 397 | /* Eliminate the COND_EXPR at the end of COND_BLOCK. */ |
75a70cf9 | 398 | gsi = gsi_last_bb (cond_block); |
399 | gsi_remove (&gsi, true); | |
20e5647c | 400 | |
902929aa | 401 | if (dump_file && (dump_flags & TDF_DETAILS)) |
402 | fprintf (dump_file, | |
403 | "COND_EXPR in block %d and PHI in block %d converted to straightline code.\n", | |
404 | cond_block->index, | |
405 | bb->index); | |
406 | } | |
407 | ||
29a78fec | 408 | /* PR66726: Factor conversion out of COND_EXPR. If the arguments of the PHI |
409 | stmt are CONVERT_STMT, factor out the conversion and perform the conversion | |
410 | to the result of PHI stmt. */ | |
411 | ||
412 | static bool | |
413 | factor_out_conditional_conversion (edge e0, edge e1, gphi *phi, | |
414 | tree arg0, tree arg1) | |
415 | { | |
42acab1c | 416 | gimple *arg0_def_stmt = NULL, *arg1_def_stmt = NULL, *new_stmt; |
29a78fec | 417 | tree new_arg0 = NULL_TREE, new_arg1 = NULL_TREE; |
418 | tree temp, result; | |
419 | gphi *newphi; | |
420 | gimple_stmt_iterator gsi, gsi_for_def; | |
421 | source_location locus = gimple_location (phi); | |
422 | enum tree_code convert_code; | |
423 | ||
424 | /* Handle only PHI statements with two arguments. TODO: If all | |
425 | other arguments to PHI are INTEGER_CST or if their defining | |
426 | statement have the same unary operation, we can handle more | |
427 | than two arguments too. */ | |
428 | if (gimple_phi_num_args (phi) != 2) | |
429 | return false; | |
430 | ||
431 | /* First canonicalize to simplify tests. */ | |
432 | if (TREE_CODE (arg0) != SSA_NAME) | |
433 | { | |
434 | std::swap (arg0, arg1); | |
435 | std::swap (e0, e1); | |
436 | } | |
437 | ||
438 | if (TREE_CODE (arg0) != SSA_NAME | |
439 | || (TREE_CODE (arg1) != SSA_NAME | |
440 | && TREE_CODE (arg1) != INTEGER_CST)) | |
441 | return false; | |
442 | ||
443 | /* Check if arg0 is an SSA_NAME and the stmt which defines arg0 is | |
444 | a conversion. */ | |
445 | arg0_def_stmt = SSA_NAME_DEF_STMT (arg0); | |
446 | if (!is_gimple_assign (arg0_def_stmt) | |
447 | || !gimple_assign_cast_p (arg0_def_stmt)) | |
448 | return false; | |
449 | ||
450 | /* Use the RHS as new_arg0. */ | |
451 | convert_code = gimple_assign_rhs_code (arg0_def_stmt); | |
452 | new_arg0 = gimple_assign_rhs1 (arg0_def_stmt); | |
453 | if (convert_code == VIEW_CONVERT_EXPR) | |
454 | new_arg0 = TREE_OPERAND (new_arg0, 0); | |
455 | ||
456 | if (TREE_CODE (arg1) == SSA_NAME) | |
457 | { | |
458 | /* Check if arg1 is an SSA_NAME and the stmt which defines arg1 | |
459 | is a conversion. */ | |
460 | arg1_def_stmt = SSA_NAME_DEF_STMT (arg1); | |
461 | if (!is_gimple_assign (arg1_def_stmt) | |
462 | || gimple_assign_rhs_code (arg1_def_stmt) != convert_code) | |
463 | return false; | |
464 | ||
465 | /* Use the RHS as new_arg1. */ | |
466 | new_arg1 = gimple_assign_rhs1 (arg1_def_stmt); | |
467 | if (convert_code == VIEW_CONVERT_EXPR) | |
468 | new_arg1 = TREE_OPERAND (new_arg1, 0); | |
469 | } | |
470 | else | |
471 | { | |
472 | /* If arg1 is an INTEGER_CST, fold it to new type. */ | |
473 | if (INTEGRAL_TYPE_P (TREE_TYPE (new_arg0)) | |
474 | && int_fits_type_p (arg1, TREE_TYPE (new_arg0))) | |
475 | { | |
476 | if (gimple_assign_cast_p (arg0_def_stmt)) | |
477 | new_arg1 = fold_convert (TREE_TYPE (new_arg0), arg1); | |
478 | else | |
479 | return false; | |
480 | } | |
481 | else | |
482 | return false; | |
483 | } | |
484 | ||
485 | /* If arg0/arg1 have > 1 use, then this transformation actually increases | |
486 | the number of expressions evaluated at runtime. */ | |
487 | if (!has_single_use (arg0) | |
488 | || (arg1_def_stmt && !has_single_use (arg1))) | |
489 | return false; | |
490 | ||
491 | /* If types of new_arg0 and new_arg1 are different bailout. */ | |
492 | if (!types_compatible_p (TREE_TYPE (new_arg0), TREE_TYPE (new_arg1))) | |
493 | return false; | |
494 | ||
495 | /* Create a new PHI stmt. */ | |
496 | result = PHI_RESULT (phi); | |
497 | temp = make_ssa_name (TREE_TYPE (new_arg0), NULL); | |
498 | newphi = create_phi_node (temp, gimple_bb (phi)); | |
499 | ||
500 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
501 | { | |
502 | fprintf (dump_file, "PHI "); | |
503 | print_generic_expr (dump_file, gimple_phi_result (phi), 0); | |
504 | fprintf (dump_file, | |
505 | " changed to factor conversion out from COND_EXPR.\n"); | |
506 | fprintf (dump_file, "New stmt with CAST that defines "); | |
507 | print_generic_expr (dump_file, result, 0); | |
508 | fprintf (dump_file, ".\n"); | |
509 | } | |
510 | ||
511 | /* Remove the old cast(s) that has single use. */ | |
512 | gsi_for_def = gsi_for_stmt (arg0_def_stmt); | |
513 | gsi_remove (&gsi_for_def, true); | |
514 | if (arg1_def_stmt) | |
515 | { | |
516 | gsi_for_def = gsi_for_stmt (arg1_def_stmt); | |
517 | gsi_remove (&gsi_for_def, true); | |
518 | } | |
519 | ||
520 | add_phi_arg (newphi, new_arg0, e0, locus); | |
521 | add_phi_arg (newphi, new_arg1, e1, locus); | |
522 | ||
523 | /* Create the conversion stmt and insert it. */ | |
524 | if (convert_code == VIEW_CONVERT_EXPR) | |
525 | temp = fold_build1 (VIEW_CONVERT_EXPR, TREE_TYPE (result), temp); | |
526 | new_stmt = gimple_build_assign (result, convert_code, temp); | |
527 | gsi = gsi_after_labels (gimple_bb (phi)); | |
528 | gsi_insert_before (&gsi, new_stmt, GSI_SAME_STMT); | |
529 | ||
530 | /* Remove he original PHI stmt. */ | |
531 | gsi = gsi_for_stmt (phi); | |
532 | gsi_remove (&gsi, true); | |
533 | return true; | |
534 | } | |
535 | ||
902929aa | 536 | /* The function conditional_replacement does the main work of doing the |
537 | conditional replacement. Return true if the replacement is done. | |
538 | Otherwise return false. | |
539 | BB is the basic block where the replacement is going to be done on. ARG0 | |
dac49aa5 | 540 | is argument 0 from PHI. Likewise for ARG1. */ |
902929aa | 541 | |
542 | static bool | |
33784d89 | 543 | conditional_replacement (basic_block cond_bb, basic_block middle_bb, |
1a91d914 | 544 | edge e0, edge e1, gphi *phi, |
33784d89 | 545 | tree arg0, tree arg1) |
902929aa | 546 | { |
547 | tree result; | |
42acab1c | 548 | gimple *stmt; |
1a91d914 | 549 | gassign *new_stmt; |
75a70cf9 | 550 | tree cond; |
551 | gimple_stmt_iterator gsi; | |
902929aa | 552 | edge true_edge, false_edge; |
75a70cf9 | 553 | tree new_var, new_var2; |
678919fd | 554 | bool neg; |
902929aa | 555 | |
435e1a75 | 556 | /* FIXME: Gimplification of complex type is too hard for now. */ |
47b88316 | 557 | /* We aren't prepared to handle vectors either (and it is a question |
558 | if it would be worthwhile anyway). */ | |
559 | if (!(INTEGRAL_TYPE_P (TREE_TYPE (arg0)) | |
560 | || POINTER_TYPE_P (TREE_TYPE (arg0))) | |
561 | || !(INTEGRAL_TYPE_P (TREE_TYPE (arg1)) | |
562 | || POINTER_TYPE_P (TREE_TYPE (arg1)))) | |
435e1a75 | 563 | return false; |
564 | ||
678919fd | 565 | /* The PHI arguments have the constants 0 and 1, or 0 and -1, then |
566 | convert it to the conditional. */ | |
902929aa | 567 | if ((integer_zerop (arg0) && integer_onep (arg1)) |
568 | || (integer_zerop (arg1) && integer_onep (arg0))) | |
678919fd | 569 | neg = false; |
570 | else if ((integer_zerop (arg0) && integer_all_onesp (arg1)) | |
571 | || (integer_zerop (arg1) && integer_all_onesp (arg0))) | |
572 | neg = true; | |
902929aa | 573 | else |
574 | return false; | |
20e5647c | 575 | |
33784d89 | 576 | if (!empty_block_p (middle_bb)) |
902929aa | 577 | return false; |
20e5647c | 578 | |
75a70cf9 | 579 | /* At this point we know we have a GIMPLE_COND with two successors. |
2ab0a163 | 580 | One successor is BB, the other successor is an empty block which |
581 | falls through into BB. | |
20e5647c | 582 | |
2ab0a163 | 583 | There is a single PHI node at the join point (BB) and its arguments |
678919fd | 584 | are constants (0, 1) or (0, -1). |
20e5647c | 585 | |
2ab0a163 | 586 | So, given the condition COND, and the two PHI arguments, we can |
20e5647c | 587 | rewrite this PHI into non-branching code: |
588 | ||
2ab0a163 | 589 | dest = (COND) or dest = COND' |
20e5647c | 590 | |
2ab0a163 | 591 | We use the condition as-is if the argument associated with the |
592 | true edge has the value one or the argument associated with the | |
593 | false edge as the value zero. Note that those conditions are not | |
75a70cf9 | 594 | the same since only one of the outgoing edges from the GIMPLE_COND |
2ab0a163 | 595 | will directly reach BB and thus be associated with an argument. */ |
ae5a4794 | 596 | |
75a70cf9 | 597 | stmt = last_stmt (cond_bb); |
598 | result = PHI_RESULT (phi); | |
b2a02a0e | 599 | |
75a70cf9 | 600 | /* To handle special cases like floating point comparison, it is easier and |
601 | less error-prone to build a tree and gimplify it on the fly though it is | |
602 | less efficient. */ | |
6f9714b3 | 603 | cond = fold_build2_loc (gimple_location (stmt), |
604 | gimple_cond_code (stmt), boolean_type_node, | |
605 | gimple_cond_lhs (stmt), gimple_cond_rhs (stmt)); | |
4ee9c684 | 606 | |
75a70cf9 | 607 | /* We need to know which is the true edge and which is the false |
608 | edge so that we know when to invert the condition below. */ | |
609 | extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge); | |
610 | if ((e0 == true_edge && integer_zerop (arg0)) | |
678919fd | 611 | || (e0 == false_edge && !integer_zerop (arg0)) |
75a70cf9 | 612 | || (e1 == true_edge && integer_zerop (arg1)) |
678919fd | 613 | || (e1 == false_edge && !integer_zerop (arg1))) |
6f9714b3 | 614 | cond = fold_build1_loc (gimple_location (stmt), |
678919fd | 615 | TRUTH_NOT_EXPR, TREE_TYPE (cond), cond); |
616 | ||
617 | if (neg) | |
618 | { | |
619 | cond = fold_convert_loc (gimple_location (stmt), | |
620 | TREE_TYPE (result), cond); | |
621 | cond = fold_build1_loc (gimple_location (stmt), | |
622 | NEGATE_EXPR, TREE_TYPE (cond), cond); | |
623 | } | |
75a70cf9 | 624 | |
625 | /* Insert our new statements at the end of conditional block before the | |
626 | COND_STMT. */ | |
627 | gsi = gsi_for_stmt (stmt); | |
628 | new_var = force_gimple_operand_gsi (&gsi, cond, true, NULL, true, | |
629 | GSI_SAME_STMT); | |
630 | ||
631 | if (!useless_type_conversion_p (TREE_TYPE (result), TREE_TYPE (new_var))) | |
632 | { | |
efbcb6de | 633 | source_location locus_0, locus_1; |
634 | ||
f9e245b2 | 635 | new_var2 = make_ssa_name (TREE_TYPE (result)); |
e9cf809e | 636 | new_stmt = gimple_build_assign (new_var2, CONVERT_EXPR, new_var); |
75a70cf9 | 637 | gsi_insert_before (&gsi, new_stmt, GSI_SAME_STMT); |
638 | new_var = new_var2; | |
efbcb6de | 639 | |
640 | /* Set the locus to the first argument, unless is doesn't have one. */ | |
641 | locus_0 = gimple_phi_arg_location (phi, 0); | |
642 | locus_1 = gimple_phi_arg_location (phi, 1); | |
643 | if (locus_0 == UNKNOWN_LOCATION) | |
644 | locus_0 = locus_1; | |
645 | gimple_set_location (new_stmt, locus_0); | |
4ee9c684 | 646 | } |
20e5647c | 647 | |
75a70cf9 | 648 | replace_phi_edge_with_variable (cond_bb, e1, phi, new_var); |
8c1ab18f | 649 | reset_flow_sensitive_info_in_bb (cond_bb); |
902929aa | 650 | |
4ee9c684 | 651 | /* Note that we optimized this PHI. */ |
652 | return true; | |
653 | } | |
654 | ||
17b9476e | 655 | /* Update *ARG which is defined in STMT so that it contains the |
656 | computed value if that seems profitable. Return true if the | |
657 | statement is made dead by that rewriting. */ | |
658 | ||
659 | static bool | |
42acab1c | 660 | jump_function_from_stmt (tree *arg, gimple *stmt) |
17b9476e | 661 | { |
662 | enum tree_code code = gimple_assign_rhs_code (stmt); | |
663 | if (code == ADDR_EXPR) | |
664 | { | |
665 | /* For arg = &p->i transform it to p, if possible. */ | |
666 | tree rhs1 = gimple_assign_rhs1 (stmt); | |
667 | HOST_WIDE_INT offset; | |
668 | tree tem = get_addr_base_and_unit_offset (TREE_OPERAND (rhs1, 0), | |
669 | &offset); | |
670 | if (tem | |
671 | && TREE_CODE (tem) == MEM_REF | |
796b6678 | 672 | && (mem_ref_offset (tem) + offset) == 0) |
17b9476e | 673 | { |
674 | *arg = TREE_OPERAND (tem, 0); | |
675 | return true; | |
676 | } | |
677 | } | |
678 | /* TODO: Much like IPA-CP jump-functions we want to handle constant | |
679 | additions symbolically here, and we'd need to update the comparison | |
680 | code that compares the arg + cst tuples in our caller. For now the | |
681 | code above exactly handles the VEC_BASE pattern from vec.h. */ | |
682 | return false; | |
683 | } | |
684 | ||
f32420fb | 685 | /* RHS is a source argument in a BIT_AND_EXPR which feeds a conditional |
686 | of the form SSA_NAME NE 0. | |
687 | ||
688 | If RHS is fed by a simple EQ_EXPR comparison of two values, see if | |
689 | the two input values of the EQ_EXPR match arg0 and arg1. | |
690 | ||
691 | If so update *code and return TRUE. Otherwise return FALSE. */ | |
692 | ||
693 | static bool | |
694 | rhs_is_fed_for_value_replacement (const_tree arg0, const_tree arg1, | |
695 | enum tree_code *code, const_tree rhs) | |
696 | { | |
697 | /* Obviously if RHS is not an SSA_NAME, we can't look at the defining | |
698 | statement. */ | |
699 | if (TREE_CODE (rhs) == SSA_NAME) | |
700 | { | |
42acab1c | 701 | gimple *def1 = SSA_NAME_DEF_STMT (rhs); |
f32420fb | 702 | |
703 | /* Verify the defining statement has an EQ_EXPR on the RHS. */ | |
704 | if (is_gimple_assign (def1) && gimple_assign_rhs_code (def1) == EQ_EXPR) | |
705 | { | |
706 | /* Finally verify the source operands of the EQ_EXPR are equal | |
707 | to arg0 and arg1. */ | |
708 | tree op0 = gimple_assign_rhs1 (def1); | |
709 | tree op1 = gimple_assign_rhs2 (def1); | |
710 | if ((operand_equal_for_phi_arg_p (arg0, op0) | |
711 | && operand_equal_for_phi_arg_p (arg1, op1)) | |
712 | || (operand_equal_for_phi_arg_p (arg0, op1) | |
713 | && operand_equal_for_phi_arg_p (arg1, op0))) | |
714 | { | |
715 | /* We will perform the optimization. */ | |
716 | *code = gimple_assign_rhs_code (def1); | |
717 | return true; | |
718 | } | |
719 | } | |
720 | } | |
721 | return false; | |
722 | } | |
723 | ||
724 | /* Return TRUE if arg0/arg1 are equal to the rhs/lhs or lhs/rhs of COND. | |
725 | ||
726 | Also return TRUE if arg0/arg1 are equal to the source arguments of a | |
727 | an EQ comparison feeding a BIT_AND_EXPR which feeds COND. | |
728 | ||
729 | Return FALSE otherwise. */ | |
730 | ||
731 | static bool | |
732 | operand_equal_for_value_replacement (const_tree arg0, const_tree arg1, | |
42acab1c | 733 | enum tree_code *code, gimple *cond) |
f32420fb | 734 | { |
42acab1c | 735 | gimple *def; |
f32420fb | 736 | tree lhs = gimple_cond_lhs (cond); |
737 | tree rhs = gimple_cond_rhs (cond); | |
738 | ||
739 | if ((operand_equal_for_phi_arg_p (arg0, lhs) | |
740 | && operand_equal_for_phi_arg_p (arg1, rhs)) | |
741 | || (operand_equal_for_phi_arg_p (arg1, lhs) | |
742 | && operand_equal_for_phi_arg_p (arg0, rhs))) | |
743 | return true; | |
744 | ||
745 | /* Now handle more complex case where we have an EQ comparison | |
746 | which feeds a BIT_AND_EXPR which feeds COND. | |
747 | ||
748 | First verify that COND is of the form SSA_NAME NE 0. */ | |
749 | if (*code != NE_EXPR || !integer_zerop (rhs) | |
750 | || TREE_CODE (lhs) != SSA_NAME) | |
751 | return false; | |
752 | ||
753 | /* Now ensure that SSA_NAME is set by a BIT_AND_EXPR. */ | |
754 | def = SSA_NAME_DEF_STMT (lhs); | |
755 | if (!is_gimple_assign (def) || gimple_assign_rhs_code (def) != BIT_AND_EXPR) | |
756 | return false; | |
757 | ||
758 | /* Now verify arg0/arg1 correspond to the source arguments of an | |
759 | EQ comparison feeding the BIT_AND_EXPR. */ | |
760 | ||
761 | tree tmp = gimple_assign_rhs1 (def); | |
762 | if (rhs_is_fed_for_value_replacement (arg0, arg1, code, tmp)) | |
763 | return true; | |
764 | ||
765 | tmp = gimple_assign_rhs2 (def); | |
766 | if (rhs_is_fed_for_value_replacement (arg0, arg1, code, tmp)) | |
767 | return true; | |
768 | ||
769 | return false; | |
770 | } | |
771 | ||
b6814ca0 | 772 | /* Returns true if ARG is a neutral element for operation CODE |
773 | on the RIGHT side. */ | |
774 | ||
775 | static bool | |
776 | neutral_element_p (tree_code code, tree arg, bool right) | |
777 | { | |
778 | switch (code) | |
779 | { | |
780 | case PLUS_EXPR: | |
781 | case BIT_IOR_EXPR: | |
782 | case BIT_XOR_EXPR: | |
783 | return integer_zerop (arg); | |
784 | ||
785 | case LROTATE_EXPR: | |
786 | case RROTATE_EXPR: | |
787 | case LSHIFT_EXPR: | |
788 | case RSHIFT_EXPR: | |
789 | case MINUS_EXPR: | |
790 | case POINTER_PLUS_EXPR: | |
791 | return right && integer_zerop (arg); | |
792 | ||
793 | case MULT_EXPR: | |
794 | return integer_onep (arg); | |
795 | ||
796 | case TRUNC_DIV_EXPR: | |
797 | case CEIL_DIV_EXPR: | |
798 | case FLOOR_DIV_EXPR: | |
799 | case ROUND_DIV_EXPR: | |
800 | case EXACT_DIV_EXPR: | |
801 | return right && integer_onep (arg); | |
802 | ||
803 | case BIT_AND_EXPR: | |
804 | return integer_all_onesp (arg); | |
805 | ||
806 | default: | |
807 | return false; | |
808 | } | |
809 | } | |
810 | ||
811 | /* Returns true if ARG is an absorbing element for operation CODE. */ | |
812 | ||
813 | static bool | |
814 | absorbing_element_p (tree_code code, tree arg) | |
815 | { | |
816 | switch (code) | |
817 | { | |
818 | case BIT_IOR_EXPR: | |
819 | return integer_all_onesp (arg); | |
820 | ||
821 | case MULT_EXPR: | |
822 | case BIT_AND_EXPR: | |
823 | return integer_zerop (arg); | |
824 | ||
825 | default: | |
826 | return false; | |
827 | } | |
828 | } | |
829 | ||
0beac6fc | 830 | /* The function value_replacement does the main work of doing the value |
fb9912ea | 831 | replacement. Return non-zero if the replacement is done. Otherwise return |
832 | 0. If we remove the middle basic block, return 2. | |
0beac6fc | 833 | BB is the basic block where the replacement is going to be done on. ARG0 |
dac49aa5 | 834 | is argument 0 from the PHI. Likewise for ARG1. */ |
0beac6fc | 835 | |
fb9912ea | 836 | static int |
33784d89 | 837 | value_replacement (basic_block cond_bb, basic_block middle_bb, |
42acab1c | 838 | edge e0, edge e1, gimple *phi, |
33784d89 | 839 | tree arg0, tree arg1) |
0beac6fc | 840 | { |
17b9476e | 841 | gimple_stmt_iterator gsi; |
42acab1c | 842 | gimple *cond; |
0beac6fc | 843 | edge true_edge, false_edge; |
75a70cf9 | 844 | enum tree_code code; |
fb9912ea | 845 | bool emtpy_or_with_defined_p = true; |
0beac6fc | 846 | |
847 | /* If the type says honor signed zeros we cannot do this | |
dac49aa5 | 848 | optimization. */ |
fe994837 | 849 | if (HONOR_SIGNED_ZEROS (arg1)) |
fb9912ea | 850 | return 0; |
0beac6fc | 851 | |
fb9912ea | 852 | /* If there is a statement in MIDDLE_BB that defines one of the PHI |
853 | arguments, then adjust arg0 or arg1. */ | |
b6814ca0 | 854 | gsi = gsi_start_nondebug_after_labels_bb (middle_bb); |
fb9912ea | 855 | while (!gsi_end_p (gsi)) |
17b9476e | 856 | { |
42acab1c | 857 | gimple *stmt = gsi_stmt (gsi); |
fb9912ea | 858 | tree lhs; |
859 | gsi_next_nondebug (&gsi); | |
860 | if (!is_gimple_assign (stmt)) | |
17b9476e | 861 | { |
fb9912ea | 862 | emtpy_or_with_defined_p = false; |
863 | continue; | |
17b9476e | 864 | } |
fb9912ea | 865 | /* Now try to adjust arg0 or arg1 according to the computation |
866 | in the statement. */ | |
867 | lhs = gimple_assign_lhs (stmt); | |
868 | if (!(lhs == arg0 | |
869 | && jump_function_from_stmt (&arg0, stmt)) | |
870 | || (lhs == arg1 | |
871 | && jump_function_from_stmt (&arg1, stmt))) | |
872 | emtpy_or_with_defined_p = false; | |
17b9476e | 873 | } |
0beac6fc | 874 | |
75a70cf9 | 875 | cond = last_stmt (cond_bb); |
876 | code = gimple_cond_code (cond); | |
0beac6fc | 877 | |
878 | /* This transformation is only valid for equality comparisons. */ | |
75a70cf9 | 879 | if (code != NE_EXPR && code != EQ_EXPR) |
fb9912ea | 880 | return 0; |
0beac6fc | 881 | |
882 | /* We need to know which is the true edge and which is the false | |
883 | edge so that we know if have abs or negative abs. */ | |
33784d89 | 884 | extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge); |
0beac6fc | 885 | |
886 | /* At this point we know we have a COND_EXPR with two successors. | |
887 | One successor is BB, the other successor is an empty block which | |
888 | falls through into BB. | |
889 | ||
890 | The condition for the COND_EXPR is known to be NE_EXPR or EQ_EXPR. | |
891 | ||
892 | There is a single PHI node at the join point (BB) with two arguments. | |
893 | ||
894 | We now need to verify that the two arguments in the PHI node match | |
895 | the two arguments to the equality comparison. */ | |
20e5647c | 896 | |
f32420fb | 897 | if (operand_equal_for_value_replacement (arg0, arg1, &code, cond)) |
0beac6fc | 898 | { |
899 | edge e; | |
900 | tree arg; | |
901 | ||
50737d20 | 902 | /* For NE_EXPR, we want to build an assignment result = arg where |
903 | arg is the PHI argument associated with the true edge. For | |
904 | EQ_EXPR we want the PHI argument associated with the false edge. */ | |
75a70cf9 | 905 | e = (code == NE_EXPR ? true_edge : false_edge); |
50737d20 | 906 | |
907 | /* Unfortunately, E may not reach BB (it may instead have gone to | |
908 | OTHER_BLOCK). If that is the case, then we want the single outgoing | |
909 | edge from OTHER_BLOCK which reaches BB and represents the desired | |
910 | path from COND_BLOCK. */ | |
33784d89 | 911 | if (e->dest == middle_bb) |
ea091dfd | 912 | e = single_succ_edge (e->dest); |
50737d20 | 913 | |
914 | /* Now we know the incoming edge to BB that has the argument for the | |
915 | RHS of our new assignment statement. */ | |
33784d89 | 916 | if (e0 == e) |
0beac6fc | 917 | arg = arg0; |
918 | else | |
919 | arg = arg1; | |
920 | ||
fb9912ea | 921 | /* If the middle basic block was empty or is defining the |
c3597b05 | 922 | PHI arguments and this is a single phi where the args are different |
923 | for the edges e0 and e1 then we can remove the middle basic block. */ | |
fb9912ea | 924 | if (emtpy_or_with_defined_p |
c3597b05 | 925 | && single_non_singleton_phi_for_edges (phi_nodes (gimple_bb (phi)), |
ce75c7c2 | 926 | e0, e1) == phi) |
fb9912ea | 927 | { |
928 | replace_phi_edge_with_variable (cond_bb, e1, phi, arg); | |
929 | /* Note that we optimized this PHI. */ | |
930 | return 2; | |
931 | } | |
932 | else | |
933 | { | |
934 | /* Replace the PHI arguments with arg. */ | |
935 | SET_PHI_ARG_DEF (phi, e0->dest_idx, arg); | |
936 | SET_PHI_ARG_DEF (phi, e1->dest_idx, arg); | |
937 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
938 | { | |
939 | fprintf (dump_file, "PHI "); | |
940 | print_generic_expr (dump_file, gimple_phi_result (phi), 0); | |
c3597b05 | 941 | fprintf (dump_file, " reduced for COND_EXPR in block %d to ", |
942 | cond_bb->index); | |
fb9912ea | 943 | print_generic_expr (dump_file, arg, 0); |
944 | fprintf (dump_file, ".\n"); | |
945 | } | |
946 | return 1; | |
947 | } | |
0beac6fc | 948 | |
0beac6fc | 949 | } |
b6814ca0 | 950 | |
951 | /* Now optimize (x != 0) ? x + y : y to just y. | |
952 | The following condition is too restrictive, there can easily be another | |
953 | stmt in middle_bb, for instance a CONVERT_EXPR for the second argument. */ | |
42acab1c | 954 | gimple *assign = last_and_only_stmt (middle_bb); |
b6814ca0 | 955 | if (!assign || gimple_code (assign) != GIMPLE_ASSIGN |
956 | || gimple_assign_rhs_class (assign) != GIMPLE_BINARY_RHS | |
957 | || (!INTEGRAL_TYPE_P (TREE_TYPE (arg0)) | |
958 | && !POINTER_TYPE_P (TREE_TYPE (arg0)))) | |
959 | return 0; | |
960 | ||
6c96fe34 | 961 | /* Punt if there are (degenerate) PHIs in middle_bb, there should not be. */ |
962 | if (!gimple_seq_empty_p (phi_nodes (middle_bb))) | |
963 | return 0; | |
964 | ||
43fbec4a | 965 | /* Only transform if it removes the condition. */ |
966 | if (!single_non_singleton_phi_for_edges (phi_nodes (gimple_bb (phi)), e0, e1)) | |
967 | return 0; | |
968 | ||
b6814ca0 | 969 | /* Size-wise, this is always profitable. */ |
970 | if (optimize_bb_for_speed_p (cond_bb) | |
971 | /* The special case is useless if it has a low probability. */ | |
972 | && profile_status_for_fn (cfun) != PROFILE_ABSENT | |
973 | && EDGE_PRED (middle_bb, 0)->probability < PROB_EVEN | |
974 | /* If assign is cheap, there is no point avoiding it. */ | |
975 | && estimate_num_insns (assign, &eni_time_weights) | |
976 | >= 3 * estimate_num_insns (cond, &eni_time_weights)) | |
977 | return 0; | |
978 | ||
979 | tree lhs = gimple_assign_lhs (assign); | |
980 | tree rhs1 = gimple_assign_rhs1 (assign); | |
981 | tree rhs2 = gimple_assign_rhs2 (assign); | |
982 | enum tree_code code_def = gimple_assign_rhs_code (assign); | |
983 | tree cond_lhs = gimple_cond_lhs (cond); | |
984 | tree cond_rhs = gimple_cond_rhs (cond); | |
985 | ||
986 | if (((code == NE_EXPR && e1 == false_edge) | |
987 | || (code == EQ_EXPR && e1 == true_edge)) | |
988 | && arg0 == lhs | |
989 | && ((arg1 == rhs1 | |
990 | && operand_equal_for_phi_arg_p (rhs2, cond_lhs) | |
991 | && neutral_element_p (code_def, cond_rhs, true)) | |
992 | || (arg1 == rhs2 | |
993 | && operand_equal_for_phi_arg_p (rhs1, cond_lhs) | |
994 | && neutral_element_p (code_def, cond_rhs, false)) | |
995 | || (operand_equal_for_phi_arg_p (arg1, cond_rhs) | |
996 | && (operand_equal_for_phi_arg_p (rhs2, cond_lhs) | |
997 | || operand_equal_for_phi_arg_p (rhs1, cond_lhs)) | |
998 | && absorbing_element_p (code_def, cond_rhs)))) | |
999 | { | |
1000 | gsi = gsi_for_stmt (cond); | |
18c06fb8 | 1001 | if (INTEGRAL_TYPE_P (TREE_TYPE (lhs))) |
1002 | { | |
1003 | /* Moving ASSIGN might change VR of lhs, e.g. when moving u_6 | |
1004 | def-stmt in: | |
1005 | if (n_5 != 0) | |
1006 | goto <bb 3>; | |
1007 | else | |
1008 | goto <bb 4>; | |
1009 | ||
1010 | <bb 3>: | |
1011 | # RANGE [0, 4294967294] | |
1012 | u_6 = n_5 + 4294967295; | |
1013 | ||
1014 | <bb 4>: | |
1015 | # u_3 = PHI <u_6(3), 4294967295(2)> */ | |
1016 | SSA_NAME_RANGE_INFO (lhs) = NULL; | |
18c06fb8 | 1017 | /* If available, we can use VR of phi result at least. */ |
1018 | tree phires = gimple_phi_result (phi); | |
1019 | struct range_info_def *phires_range_info | |
1020 | = SSA_NAME_RANGE_INFO (phires); | |
1021 | if (phires_range_info) | |
1022 | duplicate_ssa_name_range_info (lhs, SSA_NAME_RANGE_TYPE (phires), | |
1023 | phires_range_info); | |
1024 | } | |
b6814ca0 | 1025 | gimple_stmt_iterator gsi_from = gsi_for_stmt (assign); |
1026 | gsi_move_before (&gsi_from, &gsi); | |
1027 | replace_phi_edge_with_variable (cond_bb, e1, phi, lhs); | |
1028 | return 2; | |
1029 | } | |
1030 | ||
fb9912ea | 1031 | return 0; |
0beac6fc | 1032 | } |
1033 | ||
194899bf | 1034 | /* The function minmax_replacement does the main work of doing the minmax |
1035 | replacement. Return true if the replacement is done. Otherwise return | |
1036 | false. | |
1037 | BB is the basic block where the replacement is going to be done on. ARG0 | |
1038 | is argument 0 from the PHI. Likewise for ARG1. */ | |
1039 | ||
1040 | static bool | |
1041 | minmax_replacement (basic_block cond_bb, basic_block middle_bb, | |
42acab1c | 1042 | edge e0, edge e1, gimple *phi, |
194899bf | 1043 | tree arg0, tree arg1) |
1044 | { | |
1045 | tree result, type; | |
1a91d914 | 1046 | gcond *cond; |
1047 | gassign *new_stmt; | |
194899bf | 1048 | edge true_edge, false_edge; |
1049 | enum tree_code cmp, minmax, ass_code; | |
1050 | tree smaller, larger, arg_true, arg_false; | |
75a70cf9 | 1051 | gimple_stmt_iterator gsi, gsi_from; |
194899bf | 1052 | |
1053 | type = TREE_TYPE (PHI_RESULT (phi)); | |
1054 | ||
1055 | /* The optimization may be unsafe due to NaNs. */ | |
93633022 | 1056 | if (HONOR_NANS (type)) |
194899bf | 1057 | return false; |
1058 | ||
1a91d914 | 1059 | cond = as_a <gcond *> (last_stmt (cond_bb)); |
75a70cf9 | 1060 | cmp = gimple_cond_code (cond); |
194899bf | 1061 | |
1062 | /* This transformation is only valid for order comparisons. Record which | |
1063 | operand is smaller/larger if the result of the comparison is true. */ | |
1064 | if (cmp == LT_EXPR || cmp == LE_EXPR) | |
1065 | { | |
75a70cf9 | 1066 | smaller = gimple_cond_lhs (cond); |
1067 | larger = gimple_cond_rhs (cond); | |
194899bf | 1068 | } |
1069 | else if (cmp == GT_EXPR || cmp == GE_EXPR) | |
1070 | { | |
75a70cf9 | 1071 | smaller = gimple_cond_rhs (cond); |
1072 | larger = gimple_cond_lhs (cond); | |
194899bf | 1073 | } |
1074 | else | |
1075 | return false; | |
1076 | ||
1077 | /* We need to know which is the true edge and which is the false | |
1078 | edge so that we know if have abs or negative abs. */ | |
1079 | extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge); | |
1080 | ||
1081 | /* Forward the edges over the middle basic block. */ | |
1082 | if (true_edge->dest == middle_bb) | |
1083 | true_edge = EDGE_SUCC (true_edge->dest, 0); | |
1084 | if (false_edge->dest == middle_bb) | |
1085 | false_edge = EDGE_SUCC (false_edge->dest, 0); | |
1086 | ||
1087 | if (true_edge == e0) | |
1088 | { | |
1089 | gcc_assert (false_edge == e1); | |
1090 | arg_true = arg0; | |
1091 | arg_false = arg1; | |
1092 | } | |
1093 | else | |
1094 | { | |
1095 | gcc_assert (false_edge == e0); | |
1096 | gcc_assert (true_edge == e1); | |
1097 | arg_true = arg1; | |
1098 | arg_false = arg0; | |
1099 | } | |
1100 | ||
1101 | if (empty_block_p (middle_bb)) | |
1102 | { | |
1103 | if (operand_equal_for_phi_arg_p (arg_true, smaller) | |
1104 | && operand_equal_for_phi_arg_p (arg_false, larger)) | |
1105 | { | |
1106 | /* Case | |
48e1416a | 1107 | |
194899bf | 1108 | if (smaller < larger) |
1109 | rslt = smaller; | |
1110 | else | |
1111 | rslt = larger; */ | |
1112 | minmax = MIN_EXPR; | |
1113 | } | |
1114 | else if (operand_equal_for_phi_arg_p (arg_false, smaller) | |
1115 | && operand_equal_for_phi_arg_p (arg_true, larger)) | |
1116 | minmax = MAX_EXPR; | |
1117 | else | |
1118 | return false; | |
1119 | } | |
1120 | else | |
1121 | { | |
1122 | /* Recognize the following case, assuming d <= u: | |
1123 | ||
1124 | if (a <= u) | |
1125 | b = MAX (a, d); | |
1126 | x = PHI <b, u> | |
1127 | ||
1128 | This is equivalent to | |
1129 | ||
1130 | b = MAX (a, d); | |
1131 | x = MIN (b, u); */ | |
1132 | ||
42acab1c | 1133 | gimple *assign = last_and_only_stmt (middle_bb); |
75a70cf9 | 1134 | tree lhs, op0, op1, bound; |
194899bf | 1135 | |
1136 | if (!assign | |
75a70cf9 | 1137 | || gimple_code (assign) != GIMPLE_ASSIGN) |
194899bf | 1138 | return false; |
1139 | ||
75a70cf9 | 1140 | lhs = gimple_assign_lhs (assign); |
1141 | ass_code = gimple_assign_rhs_code (assign); | |
194899bf | 1142 | if (ass_code != MAX_EXPR && ass_code != MIN_EXPR) |
1143 | return false; | |
75a70cf9 | 1144 | op0 = gimple_assign_rhs1 (assign); |
1145 | op1 = gimple_assign_rhs2 (assign); | |
194899bf | 1146 | |
1147 | if (true_edge->src == middle_bb) | |
1148 | { | |
1149 | /* We got here if the condition is true, i.e., SMALLER < LARGER. */ | |
1150 | if (!operand_equal_for_phi_arg_p (lhs, arg_true)) | |
1151 | return false; | |
1152 | ||
1153 | if (operand_equal_for_phi_arg_p (arg_false, larger)) | |
1154 | { | |
1155 | /* Case | |
1156 | ||
1157 | if (smaller < larger) | |
1158 | { | |
1159 | r' = MAX_EXPR (smaller, bound) | |
1160 | } | |
1161 | r = PHI <r', larger> --> to be turned to MIN_EXPR. */ | |
1162 | if (ass_code != MAX_EXPR) | |
1163 | return false; | |
1164 | ||
1165 | minmax = MIN_EXPR; | |
1166 | if (operand_equal_for_phi_arg_p (op0, smaller)) | |
1167 | bound = op1; | |
1168 | else if (operand_equal_for_phi_arg_p (op1, smaller)) | |
1169 | bound = op0; | |
1170 | else | |
1171 | return false; | |
1172 | ||
1173 | /* We need BOUND <= LARGER. */ | |
49d00087 | 1174 | if (!integer_nonzerop (fold_build2 (LE_EXPR, boolean_type_node, |
1175 | bound, larger))) | |
194899bf | 1176 | return false; |
1177 | } | |
1178 | else if (operand_equal_for_phi_arg_p (arg_false, smaller)) | |
1179 | { | |
1180 | /* Case | |
1181 | ||
1182 | if (smaller < larger) | |
1183 | { | |
1184 | r' = MIN_EXPR (larger, bound) | |
1185 | } | |
1186 | r = PHI <r', smaller> --> to be turned to MAX_EXPR. */ | |
1187 | if (ass_code != MIN_EXPR) | |
1188 | return false; | |
1189 | ||
1190 | minmax = MAX_EXPR; | |
1191 | if (operand_equal_for_phi_arg_p (op0, larger)) | |
1192 | bound = op1; | |
1193 | else if (operand_equal_for_phi_arg_p (op1, larger)) | |
1194 | bound = op0; | |
1195 | else | |
1196 | return false; | |
1197 | ||
1198 | /* We need BOUND >= SMALLER. */ | |
49d00087 | 1199 | if (!integer_nonzerop (fold_build2 (GE_EXPR, boolean_type_node, |
1200 | bound, smaller))) | |
194899bf | 1201 | return false; |
1202 | } | |
1203 | else | |
1204 | return false; | |
1205 | } | |
1206 | else | |
1207 | { | |
1208 | /* We got here if the condition is false, i.e., SMALLER > LARGER. */ | |
1209 | if (!operand_equal_for_phi_arg_p (lhs, arg_false)) | |
1210 | return false; | |
1211 | ||
1212 | if (operand_equal_for_phi_arg_p (arg_true, larger)) | |
1213 | { | |
1214 | /* Case | |
1215 | ||
1216 | if (smaller > larger) | |
1217 | { | |
1218 | r' = MIN_EXPR (smaller, bound) | |
1219 | } | |
1220 | r = PHI <r', larger> --> to be turned to MAX_EXPR. */ | |
1221 | if (ass_code != MIN_EXPR) | |
1222 | return false; | |
1223 | ||
1224 | minmax = MAX_EXPR; | |
1225 | if (operand_equal_for_phi_arg_p (op0, smaller)) | |
1226 | bound = op1; | |
1227 | else if (operand_equal_for_phi_arg_p (op1, smaller)) | |
1228 | bound = op0; | |
1229 | else | |
1230 | return false; | |
1231 | ||
1232 | /* We need BOUND >= LARGER. */ | |
49d00087 | 1233 | if (!integer_nonzerop (fold_build2 (GE_EXPR, boolean_type_node, |
1234 | bound, larger))) | |
194899bf | 1235 | return false; |
1236 | } | |
1237 | else if (operand_equal_for_phi_arg_p (arg_true, smaller)) | |
1238 | { | |
1239 | /* Case | |
1240 | ||
1241 | if (smaller > larger) | |
1242 | { | |
1243 | r' = MAX_EXPR (larger, bound) | |
1244 | } | |
1245 | r = PHI <r', smaller> --> to be turned to MIN_EXPR. */ | |
1246 | if (ass_code != MAX_EXPR) | |
1247 | return false; | |
1248 | ||
1249 | minmax = MIN_EXPR; | |
1250 | if (operand_equal_for_phi_arg_p (op0, larger)) | |
1251 | bound = op1; | |
1252 | else if (operand_equal_for_phi_arg_p (op1, larger)) | |
1253 | bound = op0; | |
1254 | else | |
1255 | return false; | |
1256 | ||
1257 | /* We need BOUND <= SMALLER. */ | |
49d00087 | 1258 | if (!integer_nonzerop (fold_build2 (LE_EXPR, boolean_type_node, |
1259 | bound, smaller))) | |
194899bf | 1260 | return false; |
1261 | } | |
1262 | else | |
1263 | return false; | |
1264 | } | |
1265 | ||
1266 | /* Move the statement from the middle block. */ | |
75a70cf9 | 1267 | gsi = gsi_last_bb (cond_bb); |
445a6ba5 | 1268 | gsi_from = gsi_last_nondebug_bb (middle_bb); |
75a70cf9 | 1269 | gsi_move_before (&gsi_from, &gsi); |
194899bf | 1270 | } |
1271 | ||
9b604bc1 | 1272 | /* Create an SSA var to hold the min/max result. If we're the only |
1273 | things setting the target PHI, then we can clone the PHI | |
1274 | variable. Otherwise we must create a new one. */ | |
1275 | result = PHI_RESULT (phi); | |
1276 | if (EDGE_COUNT (gimple_bb (phi)->preds) == 2) | |
1277 | result = duplicate_ssa_name (result, NULL); | |
1278 | else | |
1279 | result = make_ssa_name (TREE_TYPE (result)); | |
1280 | ||
194899bf | 1281 | /* Emit the statement to compute min/max. */ |
e9cf809e | 1282 | new_stmt = gimple_build_assign (result, minmax, arg0, arg1); |
75a70cf9 | 1283 | gsi = gsi_last_bb (cond_bb); |
1284 | gsi_insert_before (&gsi, new_stmt, GSI_NEW_STMT); | |
194899bf | 1285 | |
a4844041 | 1286 | replace_phi_edge_with_variable (cond_bb, e1, phi, result); |
8c1ab18f | 1287 | reset_flow_sensitive_info_in_bb (cond_bb); |
1288 | ||
194899bf | 1289 | return true; |
1290 | } | |
1291 | ||
70512b93 | 1292 | /* The function absolute_replacement does the main work of doing the absolute |
1293 | replacement. Return true if the replacement is done. Otherwise return | |
1294 | false. | |
1295 | bb is the basic block where the replacement is going to be done on. arg0 | |
f7f07c95 | 1296 | is argument 0 from the phi. Likewise for arg1. */ |
33784d89 | 1297 | |
70512b93 | 1298 | static bool |
33784d89 | 1299 | abs_replacement (basic_block cond_bb, basic_block middle_bb, |
a4844041 | 1300 | edge e0 ATTRIBUTE_UNUSED, edge e1, |
42acab1c | 1301 | gimple *phi, tree arg0, tree arg1) |
70512b93 | 1302 | { |
1303 | tree result; | |
1a91d914 | 1304 | gassign *new_stmt; |
42acab1c | 1305 | gimple *cond; |
75a70cf9 | 1306 | gimple_stmt_iterator gsi; |
70512b93 | 1307 | edge true_edge, false_edge; |
42acab1c | 1308 | gimple *assign; |
70512b93 | 1309 | edge e; |
194899bf | 1310 | tree rhs, lhs; |
70512b93 | 1311 | bool negate; |
1312 | enum tree_code cond_code; | |
1313 | ||
1314 | /* If the type says honor signed zeros we cannot do this | |
dac49aa5 | 1315 | optimization. */ |
fe994837 | 1316 | if (HONOR_SIGNED_ZEROS (arg1)) |
70512b93 | 1317 | return false; |
1318 | ||
70512b93 | 1319 | /* OTHER_BLOCK must have only one executable statement which must have the |
1320 | form arg0 = -arg1 or arg1 = -arg0. */ | |
70512b93 | 1321 | |
194899bf | 1322 | assign = last_and_only_stmt (middle_bb); |
70512b93 | 1323 | /* If we did not find the proper negation assignment, then we can not |
1324 | optimize. */ | |
1325 | if (assign == NULL) | |
1326 | return false; | |
48e1416a | 1327 | |
194899bf | 1328 | /* If we got here, then we have found the only executable statement |
1329 | in OTHER_BLOCK. If it is anything other than arg = -arg1 or | |
1330 | arg1 = -arg0, then we can not optimize. */ | |
75a70cf9 | 1331 | if (gimple_code (assign) != GIMPLE_ASSIGN) |
194899bf | 1332 | return false; |
1333 | ||
75a70cf9 | 1334 | lhs = gimple_assign_lhs (assign); |
194899bf | 1335 | |
75a70cf9 | 1336 | if (gimple_assign_rhs_code (assign) != NEGATE_EXPR) |
194899bf | 1337 | return false; |
1338 | ||
75a70cf9 | 1339 | rhs = gimple_assign_rhs1 (assign); |
48e1416a | 1340 | |
194899bf | 1341 | /* The assignment has to be arg0 = -arg1 or arg1 = -arg0. */ |
1342 | if (!(lhs == arg0 && rhs == arg1) | |
1343 | && !(lhs == arg1 && rhs == arg0)) | |
1344 | return false; | |
70512b93 | 1345 | |
75a70cf9 | 1346 | cond = last_stmt (cond_bb); |
70512b93 | 1347 | result = PHI_RESULT (phi); |
1348 | ||
1349 | /* Only relationals comparing arg[01] against zero are interesting. */ | |
75a70cf9 | 1350 | cond_code = gimple_cond_code (cond); |
70512b93 | 1351 | if (cond_code != GT_EXPR && cond_code != GE_EXPR |
1352 | && cond_code != LT_EXPR && cond_code != LE_EXPR) | |
1353 | return false; | |
1354 | ||
dac49aa5 | 1355 | /* Make sure the conditional is arg[01] OP y. */ |
75a70cf9 | 1356 | if (gimple_cond_lhs (cond) != rhs) |
70512b93 | 1357 | return false; |
1358 | ||
75a70cf9 | 1359 | if (FLOAT_TYPE_P (TREE_TYPE (gimple_cond_rhs (cond))) |
1360 | ? real_zerop (gimple_cond_rhs (cond)) | |
1361 | : integer_zerop (gimple_cond_rhs (cond))) | |
70512b93 | 1362 | ; |
1363 | else | |
1364 | return false; | |
1365 | ||
1366 | /* We need to know which is the true edge and which is the false | |
1367 | edge so that we know if have abs or negative abs. */ | |
33784d89 | 1368 | extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge); |
70512b93 | 1369 | |
1370 | /* For GT_EXPR/GE_EXPR, if the true edge goes to OTHER_BLOCK, then we | |
1371 | will need to negate the result. Similarly for LT_EXPR/LE_EXPR if | |
1372 | the false edge goes to OTHER_BLOCK. */ | |
1373 | if (cond_code == GT_EXPR || cond_code == GE_EXPR) | |
1374 | e = true_edge; | |
1375 | else | |
1376 | e = false_edge; | |
20e5647c | 1377 | |
33784d89 | 1378 | if (e->dest == middle_bb) |
70512b93 | 1379 | negate = true; |
1380 | else | |
1381 | negate = false; | |
20e5647c | 1382 | |
33784d89 | 1383 | result = duplicate_ssa_name (result, NULL); |
20e5647c | 1384 | |
70512b93 | 1385 | if (negate) |
f9e245b2 | 1386 | lhs = make_ssa_name (TREE_TYPE (result)); |
70512b93 | 1387 | else |
1388 | lhs = result; | |
1389 | ||
dac49aa5 | 1390 | /* Build the modify expression with abs expression. */ |
e9cf809e | 1391 | new_stmt = gimple_build_assign (lhs, ABS_EXPR, rhs); |
70512b93 | 1392 | |
75a70cf9 | 1393 | gsi = gsi_last_bb (cond_bb); |
1394 | gsi_insert_before (&gsi, new_stmt, GSI_NEW_STMT); | |
70512b93 | 1395 | |
1396 | if (negate) | |
1397 | { | |
75a70cf9 | 1398 | /* Get the right GSI. We want to insert after the recently |
70512b93 | 1399 | added ABS_EXPR statement (which we know is the first statement |
1400 | in the block. */ | |
e9cf809e | 1401 | new_stmt = gimple_build_assign (result, NEGATE_EXPR, lhs); |
70512b93 | 1402 | |
75a70cf9 | 1403 | gsi_insert_after (&gsi, new_stmt, GSI_NEW_STMT); |
70512b93 | 1404 | } |
20e5647c | 1405 | |
a4844041 | 1406 | replace_phi_edge_with_variable (cond_bb, e1, phi, result); |
8c1ab18f | 1407 | reset_flow_sensitive_info_in_bb (cond_bb); |
70512b93 | 1408 | |
1409 | /* Note that we optimized this PHI. */ | |
1410 | return true; | |
1411 | } | |
1412 | ||
e6d0e152 | 1413 | /* Auxiliary functions to determine the set of memory accesses which |
1414 | can't trap because they are preceded by accesses to the same memory | |
182cf5a9 | 1415 | portion. We do that for MEM_REFs, so we only need to track |
e6d0e152 | 1416 | the SSA_NAME of the pointer indirectly referenced. The algorithm |
1417 | simply is a walk over all instructions in dominator order. When | |
182cf5a9 | 1418 | we see an MEM_REF we determine if we've already seen a same |
e6d0e152 | 1419 | ref anywhere up to the root of the dominator tree. If we do the |
af4f74fa | 1420 | current access can't trap. If we don't see any dominating access |
e6d0e152 | 1421 | the current access might trap, but might also make later accesses |
af4f74fa | 1422 | non-trapping, so we remember it. We need to be careful with loads |
1423 | or stores, for instance a load might not trap, while a store would, | |
1424 | so if we see a dominating read access this doesn't mean that a later | |
1425 | write access would not trap. Hence we also need to differentiate the | |
1426 | type of access(es) seen. | |
1427 | ||
1428 | ??? We currently are very conservative and assume that a load might | |
1429 | trap even if a store doesn't (write-only memory). This probably is | |
1430 | overly conservative. */ | |
e6d0e152 | 1431 | |
182cf5a9 | 1432 | /* A hash-table of SSA_NAMEs, and in which basic block an MEM_REF |
e6d0e152 | 1433 | through it was seen, which would constitute a no-trap region for |
1434 | same accesses. */ | |
1435 | struct name_to_bb | |
1436 | { | |
963aee26 | 1437 | unsigned int ssa_name_ver; |
42540642 | 1438 | unsigned int phase; |
963aee26 | 1439 | bool store; |
1440 | HOST_WIDE_INT offset, size; | |
e6d0e152 | 1441 | basic_block bb; |
1442 | }; | |
1443 | ||
d9dd21a8 | 1444 | /* Hashtable helpers. */ |
1445 | ||
298e7f9a | 1446 | struct ssa_names_hasher : free_ptr_hash <name_to_bb> |
d9dd21a8 | 1447 | { |
9969c043 | 1448 | static inline hashval_t hash (const name_to_bb *); |
1449 | static inline bool equal (const name_to_bb *, const name_to_bb *); | |
d9dd21a8 | 1450 | }; |
e6d0e152 | 1451 | |
42540642 | 1452 | /* Used for quick clearing of the hash-table when we see calls. |
1453 | Hash entries with phase < nt_call_phase are invalid. */ | |
1454 | static unsigned int nt_call_phase; | |
1455 | ||
963aee26 | 1456 | /* The hash function. */ |
d9dd21a8 | 1457 | |
1458 | inline hashval_t | |
9969c043 | 1459 | ssa_names_hasher::hash (const name_to_bb *n) |
e6d0e152 | 1460 | { |
963aee26 | 1461 | return n->ssa_name_ver ^ (((hashval_t) n->store) << 31) |
1462 | ^ (n->offset << 6) ^ (n->size << 3); | |
e6d0e152 | 1463 | } |
1464 | ||
963aee26 | 1465 | /* The equality function of *P1 and *P2. */ |
e6d0e152 | 1466 | |
d9dd21a8 | 1467 | inline bool |
9969c043 | 1468 | ssa_names_hasher::equal (const name_to_bb *n1, const name_to_bb *n2) |
d9dd21a8 | 1469 | { |
963aee26 | 1470 | return n1->ssa_name_ver == n2->ssa_name_ver |
1471 | && n1->store == n2->store | |
1472 | && n1->offset == n2->offset | |
1473 | && n1->size == n2->size; | |
e6d0e152 | 1474 | } |
1475 | ||
c1f445d2 | 1476 | class nontrapping_dom_walker : public dom_walker |
1477 | { | |
1478 | public: | |
431205b7 | 1479 | nontrapping_dom_walker (cdi_direction direction, hash_set<tree> *ps) |
c1f445d2 | 1480 | : dom_walker (direction), m_nontrapping (ps), m_seen_ssa_names (128) {} |
1481 | ||
1482 | virtual void before_dom_children (basic_block); | |
1483 | virtual void after_dom_children (basic_block); | |
1484 | ||
1485 | private: | |
1486 | ||
1487 | /* We see the expression EXP in basic block BB. If it's an interesting | |
1488 | expression (an MEM_REF through an SSA_NAME) possibly insert the | |
1489 | expression into the set NONTRAP or the hash table of seen expressions. | |
1490 | STORE is true if this expression is on the LHS, otherwise it's on | |
1491 | the RHS. */ | |
1492 | void add_or_mark_expr (basic_block, tree, bool); | |
1493 | ||
431205b7 | 1494 | hash_set<tree> *m_nontrapping; |
c1f445d2 | 1495 | |
1496 | /* The hash table for remembering what we've seen. */ | |
1497 | hash_table<ssa_names_hasher> m_seen_ssa_names; | |
1498 | }; | |
1499 | ||
1500 | /* Called by walk_dominator_tree, when entering the block BB. */ | |
1501 | void | |
1502 | nontrapping_dom_walker::before_dom_children (basic_block bb) | |
1503 | { | |
1504 | edge e; | |
1505 | edge_iterator ei; | |
1506 | gimple_stmt_iterator gsi; | |
1507 | ||
1508 | /* If we haven't seen all our predecessors, clear the hash-table. */ | |
1509 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1510 | if ((((size_t)e->src->aux) & 2) == 0) | |
1511 | { | |
1512 | nt_call_phase++; | |
1513 | break; | |
1514 | } | |
1515 | ||
1516 | /* Mark this BB as being on the path to dominator root and as visited. */ | |
1517 | bb->aux = (void*)(1 | 2); | |
1518 | ||
1519 | /* And walk the statements in order. */ | |
1520 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
1521 | { | |
42acab1c | 1522 | gimple *stmt = gsi_stmt (gsi); |
c1f445d2 | 1523 | |
1524 | if (is_gimple_call (stmt) && !nonfreeing_call_p (stmt)) | |
1525 | nt_call_phase++; | |
1526 | else if (gimple_assign_single_p (stmt) && !gimple_has_volatile_ops (stmt)) | |
1527 | { | |
1528 | add_or_mark_expr (bb, gimple_assign_lhs (stmt), true); | |
1529 | add_or_mark_expr (bb, gimple_assign_rhs1 (stmt), false); | |
1530 | } | |
1531 | } | |
1532 | } | |
1533 | ||
1534 | /* Called by walk_dominator_tree, when basic block BB is exited. */ | |
1535 | void | |
1536 | nontrapping_dom_walker::after_dom_children (basic_block bb) | |
1537 | { | |
1538 | /* This BB isn't on the path to dominator root anymore. */ | |
1539 | bb->aux = (void*)2; | |
1540 | } | |
d9dd21a8 | 1541 | |
f0b5f617 | 1542 | /* We see the expression EXP in basic block BB. If it's an interesting |
182cf5a9 | 1543 | expression (an MEM_REF through an SSA_NAME) possibly insert the |
af4f74fa | 1544 | expression into the set NONTRAP or the hash table of seen expressions. |
1545 | STORE is true if this expression is on the LHS, otherwise it's on | |
1546 | the RHS. */ | |
c1f445d2 | 1547 | void |
1548 | nontrapping_dom_walker::add_or_mark_expr (basic_block bb, tree exp, bool store) | |
e6d0e152 | 1549 | { |
963aee26 | 1550 | HOST_WIDE_INT size; |
1551 | ||
182cf5a9 | 1552 | if (TREE_CODE (exp) == MEM_REF |
963aee26 | 1553 | && TREE_CODE (TREE_OPERAND (exp, 0)) == SSA_NAME |
e913b5cd | 1554 | && tree_fits_shwi_p (TREE_OPERAND (exp, 1)) |
963aee26 | 1555 | && (size = int_size_in_bytes (TREE_TYPE (exp))) > 0) |
e6d0e152 | 1556 | { |
1557 | tree name = TREE_OPERAND (exp, 0); | |
1558 | struct name_to_bb map; | |
d9dd21a8 | 1559 | name_to_bb **slot; |
af4f74fa | 1560 | struct name_to_bb *n2bb; |
e6d0e152 | 1561 | basic_block found_bb = 0; |
1562 | ||
182cf5a9 | 1563 | /* Try to find the last seen MEM_REF through the same |
e6d0e152 | 1564 | SSA_NAME, which can trap. */ |
963aee26 | 1565 | map.ssa_name_ver = SSA_NAME_VERSION (name); |
42540642 | 1566 | map.phase = 0; |
e6d0e152 | 1567 | map.bb = 0; |
af4f74fa | 1568 | map.store = store; |
e913b5cd | 1569 | map.offset = tree_to_shwi (TREE_OPERAND (exp, 1)); |
963aee26 | 1570 | map.size = size; |
1571 | ||
c1f445d2 | 1572 | slot = m_seen_ssa_names.find_slot (&map, INSERT); |
d9dd21a8 | 1573 | n2bb = *slot; |
42540642 | 1574 | if (n2bb && n2bb->phase >= nt_call_phase) |
af4f74fa | 1575 | found_bb = n2bb->bb; |
e6d0e152 | 1576 | |
182cf5a9 | 1577 | /* If we've found a trapping MEM_REF, _and_ it dominates EXP |
e6d0e152 | 1578 | (it's in a basic block on the path from us to the dominator root) |
1579 | then we can't trap. */ | |
42540642 | 1580 | if (found_bb && (((size_t)found_bb->aux) & 1) == 1) |
e6d0e152 | 1581 | { |
431205b7 | 1582 | m_nontrapping->add (exp); |
e6d0e152 | 1583 | } |
1584 | else | |
1585 | { | |
1586 | /* EXP might trap, so insert it into the hash table. */ | |
af4f74fa | 1587 | if (n2bb) |
e6d0e152 | 1588 | { |
42540642 | 1589 | n2bb->phase = nt_call_phase; |
af4f74fa | 1590 | n2bb->bb = bb; |
e6d0e152 | 1591 | } |
1592 | else | |
1593 | { | |
af4f74fa | 1594 | n2bb = XNEW (struct name_to_bb); |
963aee26 | 1595 | n2bb->ssa_name_ver = SSA_NAME_VERSION (name); |
42540642 | 1596 | n2bb->phase = nt_call_phase; |
af4f74fa | 1597 | n2bb->bb = bb; |
1598 | n2bb->store = store; | |
963aee26 | 1599 | n2bb->offset = map.offset; |
1600 | n2bb->size = size; | |
af4f74fa | 1601 | *slot = n2bb; |
e6d0e152 | 1602 | } |
1603 | } | |
1604 | } | |
1605 | } | |
1606 | ||
e6d0e152 | 1607 | /* This is the entry point of gathering non trapping memory accesses. |
1608 | It will do a dominator walk over the whole function, and it will | |
1609 | make use of the bb->aux pointers. It returns a set of trees | |
182cf5a9 | 1610 | (the MEM_REFs itself) which can't trap. */ |
431205b7 | 1611 | static hash_set<tree> * |
e6d0e152 | 1612 | get_non_trapping (void) |
1613 | { | |
42540642 | 1614 | nt_call_phase = 0; |
431205b7 | 1615 | hash_set<tree> *nontrap = new hash_set<tree>; |
e6d0e152 | 1616 | /* We're going to do a dominator walk, so ensure that we have |
1617 | dominance information. */ | |
1618 | calculate_dominance_info (CDI_DOMINATORS); | |
1619 | ||
54c91640 | 1620 | nontrapping_dom_walker (CDI_DOMINATORS, nontrap) |
1621 | .walk (cfun->cfg->x_entry_block_ptr); | |
1622 | ||
42540642 | 1623 | clear_aux_for_blocks (); |
e6d0e152 | 1624 | return nontrap; |
1625 | } | |
1626 | ||
1627 | /* Do the main work of conditional store replacement. We already know | |
1628 | that the recognized pattern looks like so: | |
1629 | ||
1630 | split: | |
1631 | if (cond) goto MIDDLE_BB; else goto JOIN_BB (edge E1) | |
1632 | MIDDLE_BB: | |
1633 | something | |
1634 | fallthrough (edge E0) | |
1635 | JOIN_BB: | |
1636 | some more | |
1637 | ||
1638 | We check that MIDDLE_BB contains only one store, that that store | |
1639 | doesn't trap (not via NOTRAP, but via checking if an access to the same | |
1640 | memory location dominates us) and that the store has a "simple" RHS. */ | |
1641 | ||
1642 | static bool | |
1643 | cond_store_replacement (basic_block middle_bb, basic_block join_bb, | |
431205b7 | 1644 | edge e0, edge e1, hash_set<tree> *nontrap) |
e6d0e152 | 1645 | { |
42acab1c | 1646 | gimple *assign = last_and_only_stmt (middle_bb); |
03d37e4e | 1647 | tree lhs, rhs, name, name2; |
1a91d914 | 1648 | gphi *newphi; |
1649 | gassign *new_stmt; | |
75a70cf9 | 1650 | gimple_stmt_iterator gsi; |
efbcb6de | 1651 | source_location locus; |
e6d0e152 | 1652 | |
1653 | /* Check if middle_bb contains of only one store. */ | |
1654 | if (!assign | |
6cc085b6 | 1655 | || !gimple_assign_single_p (assign) |
1656 | || gimple_has_volatile_ops (assign)) | |
e6d0e152 | 1657 | return false; |
1658 | ||
efbcb6de | 1659 | locus = gimple_location (assign); |
75a70cf9 | 1660 | lhs = gimple_assign_lhs (assign); |
1661 | rhs = gimple_assign_rhs1 (assign); | |
182cf5a9 | 1662 | if (TREE_CODE (lhs) != MEM_REF |
91cf53d5 | 1663 | || TREE_CODE (TREE_OPERAND (lhs, 0)) != SSA_NAME |
3211fa0a | 1664 | || !is_gimple_reg_type (TREE_TYPE (lhs))) |
e6d0e152 | 1665 | return false; |
91cf53d5 | 1666 | |
e6d0e152 | 1667 | /* Prove that we can move the store down. We could also check |
1668 | TREE_THIS_NOTRAP here, but in that case we also could move stores, | |
1669 | whose value is not available readily, which we want to avoid. */ | |
431205b7 | 1670 | if (!nontrap->contains (lhs)) |
e6d0e152 | 1671 | return false; |
1672 | ||
1673 | /* Now we've checked the constraints, so do the transformation: | |
1674 | 1) Remove the single store. */ | |
75a70cf9 | 1675 | gsi = gsi_for_stmt (assign); |
3211fa0a | 1676 | unlink_stmt_vdef (assign); |
75a70cf9 | 1677 | gsi_remove (&gsi, true); |
91cf53d5 | 1678 | release_defs (assign); |
e6d0e152 | 1679 | |
03d37e4e | 1680 | /* 2) Insert a load from the memory of the store to the temporary |
e6d0e152 | 1681 | on the edge which did not contain the store. */ |
1682 | lhs = unshare_expr (lhs); | |
03d37e4e | 1683 | name = make_temp_ssa_name (TREE_TYPE (lhs), NULL, "cstore"); |
1684 | new_stmt = gimple_build_assign (name, lhs); | |
efbcb6de | 1685 | gimple_set_location (new_stmt, locus); |
75a70cf9 | 1686 | gsi_insert_on_edge (e1, new_stmt); |
e6d0e152 | 1687 | |
03d37e4e | 1688 | /* 3) Create a PHI node at the join block, with one argument |
e6d0e152 | 1689 | holding the old RHS, and the other holding the temporary |
1690 | where we stored the old memory contents. */ | |
03d37e4e | 1691 | name2 = make_temp_ssa_name (TREE_TYPE (lhs), NULL, "cstore"); |
1692 | newphi = create_phi_node (name2, join_bb); | |
60d535d2 | 1693 | add_phi_arg (newphi, rhs, e0, locus); |
1694 | add_phi_arg (newphi, name, e1, locus); | |
e6d0e152 | 1695 | |
1696 | lhs = unshare_expr (lhs); | |
75a70cf9 | 1697 | new_stmt = gimple_build_assign (lhs, PHI_RESULT (newphi)); |
e6d0e152 | 1698 | |
03d37e4e | 1699 | /* 4) Insert that PHI node. */ |
75a70cf9 | 1700 | gsi = gsi_after_labels (join_bb); |
1701 | if (gsi_end_p (gsi)) | |
e6d0e152 | 1702 | { |
75a70cf9 | 1703 | gsi = gsi_last_bb (join_bb); |
1704 | gsi_insert_after (&gsi, new_stmt, GSI_NEW_STMT); | |
e6d0e152 | 1705 | } |
1706 | else | |
75a70cf9 | 1707 | gsi_insert_before (&gsi, new_stmt, GSI_NEW_STMT); |
e6d0e152 | 1708 | |
1709 | return true; | |
1710 | } | |
4ee9c684 | 1711 | |
ec611e12 | 1712 | /* Do the main work of conditional store replacement. */ |
91cf53d5 | 1713 | |
1714 | static bool | |
ec611e12 | 1715 | cond_if_else_store_replacement_1 (basic_block then_bb, basic_block else_bb, |
42acab1c | 1716 | basic_block join_bb, gimple *then_assign, |
1717 | gimple *else_assign) | |
91cf53d5 | 1718 | { |
03d37e4e | 1719 | tree lhs_base, lhs, then_rhs, else_rhs, name; |
91cf53d5 | 1720 | source_location then_locus, else_locus; |
1721 | gimple_stmt_iterator gsi; | |
1a91d914 | 1722 | gphi *newphi; |
1723 | gassign *new_stmt; | |
91cf53d5 | 1724 | |
91cf53d5 | 1725 | if (then_assign == NULL |
1726 | || !gimple_assign_single_p (then_assign) | |
3c25489e | 1727 | || gimple_clobber_p (then_assign) |
6cc085b6 | 1728 | || gimple_has_volatile_ops (then_assign) |
91cf53d5 | 1729 | || else_assign == NULL |
3c25489e | 1730 | || !gimple_assign_single_p (else_assign) |
6cc085b6 | 1731 | || gimple_clobber_p (else_assign) |
1732 | || gimple_has_volatile_ops (else_assign)) | |
91cf53d5 | 1733 | return false; |
1734 | ||
1735 | lhs = gimple_assign_lhs (then_assign); | |
1736 | if (!is_gimple_reg_type (TREE_TYPE (lhs)) | |
1737 | || !operand_equal_p (lhs, gimple_assign_lhs (else_assign), 0)) | |
1738 | return false; | |
1739 | ||
1740 | lhs_base = get_base_address (lhs); | |
1741 | if (lhs_base == NULL_TREE | |
1742 | || (!DECL_P (lhs_base) && TREE_CODE (lhs_base) != MEM_REF)) | |
1743 | return false; | |
1744 | ||
1745 | then_rhs = gimple_assign_rhs1 (then_assign); | |
1746 | else_rhs = gimple_assign_rhs1 (else_assign); | |
1747 | then_locus = gimple_location (then_assign); | |
1748 | else_locus = gimple_location (else_assign); | |
1749 | ||
1750 | /* Now we've checked the constraints, so do the transformation: | |
1751 | 1) Remove the stores. */ | |
1752 | gsi = gsi_for_stmt (then_assign); | |
1753 | unlink_stmt_vdef (then_assign); | |
1754 | gsi_remove (&gsi, true); | |
1755 | release_defs (then_assign); | |
1756 | ||
1757 | gsi = gsi_for_stmt (else_assign); | |
1758 | unlink_stmt_vdef (else_assign); | |
1759 | gsi_remove (&gsi, true); | |
1760 | release_defs (else_assign); | |
1761 | ||
03d37e4e | 1762 | /* 2) Create a PHI node at the join block, with one argument |
91cf53d5 | 1763 | holding the old RHS, and the other holding the temporary |
1764 | where we stored the old memory contents. */ | |
03d37e4e | 1765 | name = make_temp_ssa_name (TREE_TYPE (lhs), NULL, "cstore"); |
1766 | newphi = create_phi_node (name, join_bb); | |
60d535d2 | 1767 | add_phi_arg (newphi, then_rhs, EDGE_SUCC (then_bb, 0), then_locus); |
1768 | add_phi_arg (newphi, else_rhs, EDGE_SUCC (else_bb, 0), else_locus); | |
91cf53d5 | 1769 | |
1770 | new_stmt = gimple_build_assign (lhs, PHI_RESULT (newphi)); | |
1771 | ||
03d37e4e | 1772 | /* 3) Insert that PHI node. */ |
91cf53d5 | 1773 | gsi = gsi_after_labels (join_bb); |
1774 | if (gsi_end_p (gsi)) | |
1775 | { | |
1776 | gsi = gsi_last_bb (join_bb); | |
1777 | gsi_insert_after (&gsi, new_stmt, GSI_NEW_STMT); | |
1778 | } | |
1779 | else | |
1780 | gsi_insert_before (&gsi, new_stmt, GSI_NEW_STMT); | |
1781 | ||
1782 | return true; | |
1783 | } | |
1784 | ||
ec611e12 | 1785 | /* Conditional store replacement. We already know |
1786 | that the recognized pattern looks like so: | |
1787 | ||
1788 | split: | |
1789 | if (cond) goto THEN_BB; else goto ELSE_BB (edge E1) | |
1790 | THEN_BB: | |
1791 | ... | |
1792 | X = Y; | |
1793 | ... | |
1794 | goto JOIN_BB; | |
1795 | ELSE_BB: | |
1796 | ... | |
1797 | X = Z; | |
1798 | ... | |
1799 | fallthrough (edge E0) | |
1800 | JOIN_BB: | |
1801 | some more | |
1802 | ||
1803 | We check that it is safe to sink the store to JOIN_BB by verifying that | |
1804 | there are no read-after-write or write-after-write dependencies in | |
1805 | THEN_BB and ELSE_BB. */ | |
1806 | ||
1807 | static bool | |
1808 | cond_if_else_store_replacement (basic_block then_bb, basic_block else_bb, | |
1809 | basic_block join_bb) | |
1810 | { | |
42acab1c | 1811 | gimple *then_assign = last_and_only_stmt (then_bb); |
1812 | gimple *else_assign = last_and_only_stmt (else_bb); | |
f1f41a6c | 1813 | vec<data_reference_p> then_datarefs, else_datarefs; |
1814 | vec<ddr_p> then_ddrs, else_ddrs; | |
42acab1c | 1815 | gimple *then_store, *else_store; |
ec611e12 | 1816 | bool found, ok = false, res; |
1817 | struct data_dependence_relation *ddr; | |
1818 | data_reference_p then_dr, else_dr; | |
1819 | int i, j; | |
1820 | tree then_lhs, else_lhs; | |
ec611e12 | 1821 | basic_block blocks[3]; |
1822 | ||
1823 | if (MAX_STORES_TO_SINK == 0) | |
1824 | return false; | |
1825 | ||
1826 | /* Handle the case with single statement in THEN_BB and ELSE_BB. */ | |
1827 | if (then_assign && else_assign) | |
1828 | return cond_if_else_store_replacement_1 (then_bb, else_bb, join_bb, | |
1829 | then_assign, else_assign); | |
1830 | ||
1831 | /* Find data references. */ | |
f1f41a6c | 1832 | then_datarefs.create (1); |
1833 | else_datarefs.create (1); | |
ec611e12 | 1834 | if ((find_data_references_in_bb (NULL, then_bb, &then_datarefs) |
1835 | == chrec_dont_know) | |
f1f41a6c | 1836 | || !then_datarefs.length () |
ec611e12 | 1837 | || (find_data_references_in_bb (NULL, else_bb, &else_datarefs) |
c71d3c24 | 1838 | == chrec_dont_know) |
f1f41a6c | 1839 | || !else_datarefs.length ()) |
ec611e12 | 1840 | { |
1841 | free_data_refs (then_datarefs); | |
1842 | free_data_refs (else_datarefs); | |
1843 | return false; | |
1844 | } | |
1845 | ||
1846 | /* Find pairs of stores with equal LHS. */ | |
42acab1c | 1847 | auto_vec<gimple *, 1> then_stores, else_stores; |
f1f41a6c | 1848 | FOR_EACH_VEC_ELT (then_datarefs, i, then_dr) |
ec611e12 | 1849 | { |
1850 | if (DR_IS_READ (then_dr)) | |
1851 | continue; | |
1852 | ||
1853 | then_store = DR_STMT (then_dr); | |
728dcc71 | 1854 | then_lhs = gimple_get_lhs (then_store); |
c71d3c24 | 1855 | if (then_lhs == NULL_TREE) |
1856 | continue; | |
ec611e12 | 1857 | found = false; |
1858 | ||
f1f41a6c | 1859 | FOR_EACH_VEC_ELT (else_datarefs, j, else_dr) |
ec611e12 | 1860 | { |
1861 | if (DR_IS_READ (else_dr)) | |
1862 | continue; | |
1863 | ||
1864 | else_store = DR_STMT (else_dr); | |
728dcc71 | 1865 | else_lhs = gimple_get_lhs (else_store); |
c71d3c24 | 1866 | if (else_lhs == NULL_TREE) |
1867 | continue; | |
ec611e12 | 1868 | |
1869 | if (operand_equal_p (then_lhs, else_lhs, 0)) | |
1870 | { | |
1871 | found = true; | |
1872 | break; | |
1873 | } | |
1874 | } | |
1875 | ||
1876 | if (!found) | |
1877 | continue; | |
1878 | ||
f1f41a6c | 1879 | then_stores.safe_push (then_store); |
1880 | else_stores.safe_push (else_store); | |
ec611e12 | 1881 | } |
1882 | ||
1883 | /* No pairs of stores found. */ | |
f1f41a6c | 1884 | if (!then_stores.length () |
1885 | || then_stores.length () > (unsigned) MAX_STORES_TO_SINK) | |
ec611e12 | 1886 | { |
1887 | free_data_refs (then_datarefs); | |
1888 | free_data_refs (else_datarefs); | |
ec611e12 | 1889 | return false; |
1890 | } | |
1891 | ||
1892 | /* Compute and check data dependencies in both basic blocks. */ | |
f1f41a6c | 1893 | then_ddrs.create (1); |
1894 | else_ddrs.create (1); | |
1895 | if (!compute_all_dependences (then_datarefs, &then_ddrs, | |
1e094109 | 1896 | vNULL, false) |
f1f41a6c | 1897 | || !compute_all_dependences (else_datarefs, &else_ddrs, |
1e094109 | 1898 | vNULL, false)) |
8b3fb720 | 1899 | { |
1900 | free_dependence_relations (then_ddrs); | |
1901 | free_dependence_relations (else_ddrs); | |
1902 | free_data_refs (then_datarefs); | |
1903 | free_data_refs (else_datarefs); | |
8b3fb720 | 1904 | return false; |
1905 | } | |
ec611e12 | 1906 | blocks[0] = then_bb; |
1907 | blocks[1] = else_bb; | |
1908 | blocks[2] = join_bb; | |
1909 | renumber_gimple_stmt_uids_in_blocks (blocks, 3); | |
1910 | ||
1911 | /* Check that there are no read-after-write or write-after-write dependencies | |
1912 | in THEN_BB. */ | |
f1f41a6c | 1913 | FOR_EACH_VEC_ELT (then_ddrs, i, ddr) |
ec611e12 | 1914 | { |
1915 | struct data_reference *dra = DDR_A (ddr); | |
1916 | struct data_reference *drb = DDR_B (ddr); | |
1917 | ||
1918 | if (DDR_ARE_DEPENDENT (ddr) != chrec_known | |
1919 | && ((DR_IS_READ (dra) && DR_IS_WRITE (drb) | |
1920 | && gimple_uid (DR_STMT (dra)) > gimple_uid (DR_STMT (drb))) | |
1921 | || (DR_IS_READ (drb) && DR_IS_WRITE (dra) | |
1922 | && gimple_uid (DR_STMT (drb)) > gimple_uid (DR_STMT (dra))) | |
1923 | || (DR_IS_WRITE (dra) && DR_IS_WRITE (drb)))) | |
1924 | { | |
1925 | free_dependence_relations (then_ddrs); | |
1926 | free_dependence_relations (else_ddrs); | |
2473bfb7 | 1927 | free_data_refs (then_datarefs); |
1928 | free_data_refs (else_datarefs); | |
ec611e12 | 1929 | return false; |
1930 | } | |
1931 | } | |
1932 | ||
1933 | /* Check that there are no read-after-write or write-after-write dependencies | |
1934 | in ELSE_BB. */ | |
f1f41a6c | 1935 | FOR_EACH_VEC_ELT (else_ddrs, i, ddr) |
ec611e12 | 1936 | { |
1937 | struct data_reference *dra = DDR_A (ddr); | |
1938 | struct data_reference *drb = DDR_B (ddr); | |
1939 | ||
1940 | if (DDR_ARE_DEPENDENT (ddr) != chrec_known | |
1941 | && ((DR_IS_READ (dra) && DR_IS_WRITE (drb) | |
1942 | && gimple_uid (DR_STMT (dra)) > gimple_uid (DR_STMT (drb))) | |
1943 | || (DR_IS_READ (drb) && DR_IS_WRITE (dra) | |
1944 | && gimple_uid (DR_STMT (drb)) > gimple_uid (DR_STMT (dra))) | |
1945 | || (DR_IS_WRITE (dra) && DR_IS_WRITE (drb)))) | |
1946 | { | |
1947 | free_dependence_relations (then_ddrs); | |
1948 | free_dependence_relations (else_ddrs); | |
2473bfb7 | 1949 | free_data_refs (then_datarefs); |
1950 | free_data_refs (else_datarefs); | |
ec611e12 | 1951 | return false; |
1952 | } | |
1953 | } | |
1954 | ||
1955 | /* Sink stores with same LHS. */ | |
f1f41a6c | 1956 | FOR_EACH_VEC_ELT (then_stores, i, then_store) |
ec611e12 | 1957 | { |
f1f41a6c | 1958 | else_store = else_stores[i]; |
ec611e12 | 1959 | res = cond_if_else_store_replacement_1 (then_bb, else_bb, join_bb, |
1960 | then_store, else_store); | |
1961 | ok = ok || res; | |
1962 | } | |
1963 | ||
1964 | free_dependence_relations (then_ddrs); | |
1965 | free_dependence_relations (else_ddrs); | |
2473bfb7 | 1966 | free_data_refs (then_datarefs); |
1967 | free_data_refs (else_datarefs); | |
ec611e12 | 1968 | |
1969 | return ok; | |
1970 | } | |
1971 | ||
239e9670 | 1972 | /* Return TRUE if STMT has a VUSE whose corresponding VDEF is in BB. */ |
1973 | ||
1974 | static bool | |
42acab1c | 1975 | local_mem_dependence (gimple *stmt, basic_block bb) |
239e9670 | 1976 | { |
1977 | tree vuse = gimple_vuse (stmt); | |
42acab1c | 1978 | gimple *def; |
239e9670 | 1979 | |
1980 | if (!vuse) | |
1981 | return false; | |
1982 | ||
1983 | def = SSA_NAME_DEF_STMT (vuse); | |
1984 | return (def && gimple_bb (def) == bb); | |
1985 | } | |
1986 | ||
1987 | /* Given a "diamond" control-flow pattern where BB0 tests a condition, | |
1988 | BB1 and BB2 are "then" and "else" blocks dependent on this test, | |
f32420fb | 1989 | and BB3 rejoins control flow following BB1 and BB2, look for |
239e9670 | 1990 | opportunities to hoist loads as follows. If BB3 contains a PHI of |
1991 | two loads, one each occurring in BB1 and BB2, and the loads are | |
1992 | provably of adjacent fields in the same structure, then move both | |
1993 | loads into BB0. Of course this can only be done if there are no | |
1994 | dependencies preventing such motion. | |
1995 | ||
1996 | One of the hoisted loads will always be speculative, so the | |
1997 | transformation is currently conservative: | |
1998 | ||
1999 | - The fields must be strictly adjacent. | |
2000 | - The two fields must occupy a single memory block that is | |
2001 | guaranteed to not cross a page boundary. | |
2002 | ||
2003 | The last is difficult to prove, as such memory blocks should be | |
2004 | aligned on the minimum of the stack alignment boundary and the | |
2005 | alignment guaranteed by heap allocation interfaces. Thus we rely | |
2006 | on a parameter for the alignment value. | |
2007 | ||
2008 | Provided a good value is used for the last case, the first | |
2009 | restriction could possibly be relaxed. */ | |
2010 | ||
2011 | static void | |
2012 | hoist_adjacent_loads (basic_block bb0, basic_block bb1, | |
2013 | basic_block bb2, basic_block bb3) | |
2014 | { | |
2015 | int param_align = PARAM_VALUE (PARAM_L1_CACHE_LINE_SIZE); | |
2016 | unsigned param_align_bits = (unsigned) (param_align * BITS_PER_UNIT); | |
1a91d914 | 2017 | gphi_iterator gsi; |
239e9670 | 2018 | |
2019 | /* Walk the phis in bb3 looking for an opportunity. We are looking | |
2020 | for phis of two SSA names, one each of which is defined in bb1 and | |
2021 | bb2. */ | |
2022 | for (gsi = gsi_start_phis (bb3); !gsi_end_p (gsi); gsi_next (&gsi)) | |
2023 | { | |
1a91d914 | 2024 | gphi *phi_stmt = gsi.phi (); |
42acab1c | 2025 | gimple *def1, *def2; |
dfcf26a5 | 2026 | tree arg1, arg2, ref1, ref2, field1, field2; |
239e9670 | 2027 | tree tree_offset1, tree_offset2, tree_size2, next; |
2028 | int offset1, offset2, size2; | |
2029 | unsigned align1; | |
2030 | gimple_stmt_iterator gsi2; | |
2031 | basic_block bb_for_def1, bb_for_def2; | |
2032 | ||
7c782c9b | 2033 | if (gimple_phi_num_args (phi_stmt) != 2 |
2034 | || virtual_operand_p (gimple_phi_result (phi_stmt))) | |
239e9670 | 2035 | continue; |
2036 | ||
2037 | arg1 = gimple_phi_arg_def (phi_stmt, 0); | |
2038 | arg2 = gimple_phi_arg_def (phi_stmt, 1); | |
f32420fb | 2039 | |
239e9670 | 2040 | if (TREE_CODE (arg1) != SSA_NAME |
2041 | || TREE_CODE (arg2) != SSA_NAME | |
2042 | || SSA_NAME_IS_DEFAULT_DEF (arg1) | |
7c782c9b | 2043 | || SSA_NAME_IS_DEFAULT_DEF (arg2)) |
239e9670 | 2044 | continue; |
2045 | ||
2046 | def1 = SSA_NAME_DEF_STMT (arg1); | |
2047 | def2 = SSA_NAME_DEF_STMT (arg2); | |
2048 | ||
2049 | if ((gimple_bb (def1) != bb1 || gimple_bb (def2) != bb2) | |
2050 | && (gimple_bb (def2) != bb1 || gimple_bb (def1) != bb2)) | |
2051 | continue; | |
2052 | ||
2053 | /* Check the mode of the arguments to be sure a conditional move | |
2054 | can be generated for it. */ | |
935611bc | 2055 | if (optab_handler (movcc_optab, TYPE_MODE (TREE_TYPE (arg1))) |
2056 | == CODE_FOR_nothing) | |
239e9670 | 2057 | continue; |
2058 | ||
2059 | /* Both statements must be assignments whose RHS is a COMPONENT_REF. */ | |
2060 | if (!gimple_assign_single_p (def1) | |
6cc085b6 | 2061 | || !gimple_assign_single_p (def2) |
2062 | || gimple_has_volatile_ops (def1) | |
2063 | || gimple_has_volatile_ops (def2)) | |
239e9670 | 2064 | continue; |
2065 | ||
2066 | ref1 = gimple_assign_rhs1 (def1); | |
2067 | ref2 = gimple_assign_rhs1 (def2); | |
2068 | ||
2069 | if (TREE_CODE (ref1) != COMPONENT_REF | |
2070 | || TREE_CODE (ref2) != COMPONENT_REF) | |
2071 | continue; | |
2072 | ||
2073 | /* The zeroth operand of the two component references must be | |
2074 | identical. It is not sufficient to compare get_base_address of | |
2075 | the two references, because this could allow for different | |
2076 | elements of the same array in the two trees. It is not safe to | |
2077 | assume that the existence of one array element implies the | |
2078 | existence of a different one. */ | |
2079 | if (!operand_equal_p (TREE_OPERAND (ref1, 0), TREE_OPERAND (ref2, 0), 0)) | |
2080 | continue; | |
2081 | ||
2082 | field1 = TREE_OPERAND (ref1, 1); | |
2083 | field2 = TREE_OPERAND (ref2, 1); | |
2084 | ||
2085 | /* Check for field adjacency, and ensure field1 comes first. */ | |
2086 | for (next = DECL_CHAIN (field1); | |
2087 | next && TREE_CODE (next) != FIELD_DECL; | |
2088 | next = DECL_CHAIN (next)) | |
2089 | ; | |
2090 | ||
2091 | if (next != field2) | |
2092 | { | |
2093 | for (next = DECL_CHAIN (field2); | |
2094 | next && TREE_CODE (next) != FIELD_DECL; | |
2095 | next = DECL_CHAIN (next)) | |
2096 | ; | |
2097 | ||
2098 | if (next != field1) | |
2099 | continue; | |
2100 | ||
dfcf26a5 | 2101 | std::swap (field1, field2); |
2102 | std::swap (def1, def2); | |
239e9670 | 2103 | } |
2104 | ||
7c74ee50 | 2105 | bb_for_def1 = gimple_bb (def1); |
2106 | bb_for_def2 = gimple_bb (def2); | |
2107 | ||
239e9670 | 2108 | /* Check for proper alignment of the first field. */ |
2109 | tree_offset1 = bit_position (field1); | |
2110 | tree_offset2 = bit_position (field2); | |
2111 | tree_size2 = DECL_SIZE (field2); | |
2112 | ||
e913b5cd | 2113 | if (!tree_fits_uhwi_p (tree_offset1) |
2114 | || !tree_fits_uhwi_p (tree_offset2) | |
2115 | || !tree_fits_uhwi_p (tree_size2)) | |
239e9670 | 2116 | continue; |
2117 | ||
e913b5cd | 2118 | offset1 = tree_to_uhwi (tree_offset1); |
2119 | offset2 = tree_to_uhwi (tree_offset2); | |
2120 | size2 = tree_to_uhwi (tree_size2); | |
239e9670 | 2121 | align1 = DECL_ALIGN (field1) % param_align_bits; |
2122 | ||
2123 | if (offset1 % BITS_PER_UNIT != 0) | |
2124 | continue; | |
2125 | ||
2126 | /* For profitability, the two field references should fit within | |
2127 | a single cache line. */ | |
2128 | if (align1 + offset2 - offset1 + size2 > param_align_bits) | |
2129 | continue; | |
2130 | ||
2131 | /* The two expressions cannot be dependent upon vdefs defined | |
2132 | in bb1/bb2. */ | |
2133 | if (local_mem_dependence (def1, bb_for_def1) | |
2134 | || local_mem_dependence (def2, bb_for_def2)) | |
2135 | continue; | |
2136 | ||
2137 | /* The conditions are satisfied; hoist the loads from bb1 and bb2 into | |
2138 | bb0. We hoist the first one first so that a cache miss is handled | |
2139 | efficiently regardless of hardware cache-fill policy. */ | |
2140 | gsi2 = gsi_for_stmt (def1); | |
2141 | gsi_move_to_bb_end (&gsi2, bb0); | |
2142 | gsi2 = gsi_for_stmt (def2); | |
2143 | gsi_move_to_bb_end (&gsi2, bb0); | |
2144 | ||
2145 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2146 | { | |
2147 | fprintf (dump_file, | |
2148 | "\nHoisting adjacent loads from %d and %d into %d: \n", | |
2149 | bb_for_def1->index, bb_for_def2->index, bb0->index); | |
2150 | print_gimple_stmt (dump_file, def1, 0, TDF_VOPS|TDF_MEMSYMS); | |
2151 | print_gimple_stmt (dump_file, def2, 0, TDF_VOPS|TDF_MEMSYMS); | |
2152 | } | |
2153 | } | |
2154 | } | |
2155 | ||
2156 | /* Determine whether we should attempt to hoist adjacent loads out of | |
2157 | diamond patterns in pass_phiopt. Always hoist loads if | |
2158 | -fhoist-adjacent-loads is specified and the target machine has | |
6f0ddab1 | 2159 | both a conditional move instruction and a defined cache line size. */ |
239e9670 | 2160 | |
2161 | static bool | |
2162 | gate_hoist_loads (void) | |
2163 | { | |
6f0ddab1 | 2164 | return (flag_hoist_adjacent_loads == 1 |
2165 | && PARAM_VALUE (PARAM_L1_CACHE_LINE_SIZE) | |
2166 | && HAVE_conditional_move); | |
239e9670 | 2167 | } |
2168 | ||
65b0537f | 2169 | /* This pass tries to replaces an if-then-else block with an |
2170 | assignment. We have four kinds of transformations. Some of these | |
2171 | transformations are also performed by the ifcvt RTL optimizer. | |
2172 | ||
2173 | Conditional Replacement | |
2174 | ----------------------- | |
2175 | ||
2176 | This transformation, implemented in conditional_replacement, | |
2177 | replaces | |
2178 | ||
2179 | bb0: | |
2180 | if (cond) goto bb2; else goto bb1; | |
2181 | bb1: | |
2182 | bb2: | |
2183 | x = PHI <0 (bb1), 1 (bb0), ...>; | |
2184 | ||
2185 | with | |
2186 | ||
2187 | bb0: | |
2188 | x' = cond; | |
2189 | goto bb2; | |
2190 | bb2: | |
2191 | x = PHI <x' (bb0), ...>; | |
2192 | ||
2193 | We remove bb1 as it becomes unreachable. This occurs often due to | |
2194 | gimplification of conditionals. | |
2195 | ||
2196 | Value Replacement | |
2197 | ----------------- | |
2198 | ||
2199 | This transformation, implemented in value_replacement, replaces | |
2200 | ||
2201 | bb0: | |
2202 | if (a != b) goto bb2; else goto bb1; | |
2203 | bb1: | |
2204 | bb2: | |
2205 | x = PHI <a (bb1), b (bb0), ...>; | |
2206 | ||
2207 | with | |
2208 | ||
2209 | bb0: | |
2210 | bb2: | |
2211 | x = PHI <b (bb0), ...>; | |
2212 | ||
2213 | This opportunity can sometimes occur as a result of other | |
2214 | optimizations. | |
2215 | ||
2216 | ||
2217 | Another case caught by value replacement looks like this: | |
2218 | ||
2219 | bb0: | |
2220 | t1 = a == CONST; | |
2221 | t2 = b > c; | |
2222 | t3 = t1 & t2; | |
2223 | if (t3 != 0) goto bb1; else goto bb2; | |
2224 | bb1: | |
2225 | bb2: | |
2226 | x = PHI (CONST, a) | |
2227 | ||
2228 | Gets replaced with: | |
2229 | bb0: | |
2230 | bb2: | |
2231 | t1 = a == CONST; | |
2232 | t2 = b > c; | |
2233 | t3 = t1 & t2; | |
2234 | x = a; | |
2235 | ||
2236 | ABS Replacement | |
2237 | --------------- | |
2238 | ||
2239 | This transformation, implemented in abs_replacement, replaces | |
2240 | ||
2241 | bb0: | |
2242 | if (a >= 0) goto bb2; else goto bb1; | |
2243 | bb1: | |
2244 | x = -a; | |
2245 | bb2: | |
2246 | x = PHI <x (bb1), a (bb0), ...>; | |
2247 | ||
2248 | with | |
2249 | ||
2250 | bb0: | |
2251 | x' = ABS_EXPR< a >; | |
2252 | bb2: | |
2253 | x = PHI <x' (bb0), ...>; | |
2254 | ||
2255 | MIN/MAX Replacement | |
2256 | ------------------- | |
2257 | ||
2258 | This transformation, minmax_replacement replaces | |
2259 | ||
2260 | bb0: | |
2261 | if (a <= b) goto bb2; else goto bb1; | |
2262 | bb1: | |
2263 | bb2: | |
2264 | x = PHI <b (bb1), a (bb0), ...>; | |
2265 | ||
2266 | with | |
2267 | ||
2268 | bb0: | |
2269 | x' = MIN_EXPR (a, b) | |
2270 | bb2: | |
2271 | x = PHI <x' (bb0), ...>; | |
2272 | ||
2273 | A similar transformation is done for MAX_EXPR. | |
2274 | ||
2275 | ||
2276 | This pass also performs a fifth transformation of a slightly different | |
2277 | flavor. | |
2278 | ||
29a78fec | 2279 | Factor conversion in COND_EXPR |
2280 | ------------------------------ | |
2281 | ||
2282 | This transformation factors the conversion out of COND_EXPR with | |
2283 | factor_out_conditional_conversion. | |
2284 | ||
2285 | For example: | |
2286 | if (a <= CST) goto <bb 3>; else goto <bb 4>; | |
2287 | <bb 3>: | |
2288 | tmp = (int) a; | |
2289 | <bb 4>: | |
2290 | tmp = PHI <tmp, CST> | |
2291 | ||
2292 | Into: | |
2293 | if (a <= CST) goto <bb 3>; else goto <bb 4>; | |
2294 | <bb 3>: | |
2295 | <bb 4>: | |
2296 | a = PHI <a, CST> | |
2297 | tmp = (int) a; | |
2298 | ||
65b0537f | 2299 | Adjacent Load Hoisting |
2300 | ---------------------- | |
2301 | ||
2302 | This transformation replaces | |
2303 | ||
2304 | bb0: | |
2305 | if (...) goto bb2; else goto bb1; | |
2306 | bb1: | |
2307 | x1 = (<expr>).field1; | |
2308 | goto bb3; | |
2309 | bb2: | |
2310 | x2 = (<expr>).field2; | |
2311 | bb3: | |
2312 | # x = PHI <x1, x2>; | |
2313 | ||
2314 | with | |
2315 | ||
2316 | bb0: | |
2317 | x1 = (<expr>).field1; | |
2318 | x2 = (<expr>).field2; | |
2319 | if (...) goto bb2; else goto bb1; | |
2320 | bb1: | |
2321 | goto bb3; | |
2322 | bb2: | |
2323 | bb3: | |
2324 | # x = PHI <x1, x2>; | |
2325 | ||
2326 | The purpose of this transformation is to enable generation of conditional | |
2327 | move instructions such as Intel CMOVE or PowerPC ISEL. Because one of | |
2328 | the loads is speculative, the transformation is restricted to very | |
2329 | specific cases to avoid introducing a page fault. We are looking for | |
2330 | the common idiom: | |
2331 | ||
2332 | if (...) | |
2333 | x = y->left; | |
2334 | else | |
2335 | x = y->right; | |
2336 | ||
2337 | where left and right are typically adjacent pointers in a tree structure. */ | |
20e5647c | 2338 | |
cbe8bda8 | 2339 | namespace { |
2340 | ||
2341 | const pass_data pass_data_phiopt = | |
4ee9c684 | 2342 | { |
cbe8bda8 | 2343 | GIMPLE_PASS, /* type */ |
2344 | "phiopt", /* name */ | |
2345 | OPTGROUP_NONE, /* optinfo_flags */ | |
cbe8bda8 | 2346 | TV_TREE_PHIOPT, /* tv_id */ |
2347 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
2348 | 0, /* properties_provided */ | |
2349 | 0, /* properties_destroyed */ | |
2350 | 0, /* todo_flags_start */ | |
8b88439e | 2351 | 0, /* todo_flags_finish */ |
4ee9c684 | 2352 | }; |
e6d0e152 | 2353 | |
cbe8bda8 | 2354 | class pass_phiopt : public gimple_opt_pass |
2355 | { | |
2356 | public: | |
9af5ce0c | 2357 | pass_phiopt (gcc::context *ctxt) |
2358 | : gimple_opt_pass (pass_data_phiopt, ctxt) | |
cbe8bda8 | 2359 | {} |
2360 | ||
2361 | /* opt_pass methods: */ | |
ae84f584 | 2362 | opt_pass * clone () { return new pass_phiopt (m_ctxt); } |
3dac50cc | 2363 | virtual bool gate (function *) { return flag_ssa_phiopt; } |
65b0537f | 2364 | virtual unsigned int execute (function *) |
2365 | { | |
2366 | return tree_ssa_phiopt_worker (false, gate_hoist_loads ()); | |
2367 | } | |
cbe8bda8 | 2368 | |
2369 | }; // class pass_phiopt | |
2370 | ||
2371 | } // anon namespace | |
2372 | ||
2373 | gimple_opt_pass * | |
2374 | make_pass_phiopt (gcc::context *ctxt) | |
2375 | { | |
2376 | return new pass_phiopt (ctxt); | |
2377 | } | |
2378 | ||
cbe8bda8 | 2379 | namespace { |
2380 | ||
2381 | const pass_data pass_data_cselim = | |
e6d0e152 | 2382 | { |
cbe8bda8 | 2383 | GIMPLE_PASS, /* type */ |
2384 | "cselim", /* name */ | |
2385 | OPTGROUP_NONE, /* optinfo_flags */ | |
cbe8bda8 | 2386 | TV_TREE_PHIOPT, /* tv_id */ |
2387 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
2388 | 0, /* properties_provided */ | |
2389 | 0, /* properties_destroyed */ | |
2390 | 0, /* todo_flags_start */ | |
8b88439e | 2391 | 0, /* todo_flags_finish */ |
e6d0e152 | 2392 | }; |
cbe8bda8 | 2393 | |
2394 | class pass_cselim : public gimple_opt_pass | |
2395 | { | |
2396 | public: | |
9af5ce0c | 2397 | pass_cselim (gcc::context *ctxt) |
2398 | : gimple_opt_pass (pass_data_cselim, ctxt) | |
cbe8bda8 | 2399 | {} |
2400 | ||
2401 | /* opt_pass methods: */ | |
31315c24 | 2402 | virtual bool gate (function *) { return flag_tree_cselim; } |
65b0537f | 2403 | virtual unsigned int execute (function *) { return tree_ssa_cs_elim (); } |
cbe8bda8 | 2404 | |
2405 | }; // class pass_cselim | |
2406 | ||
2407 | } // anon namespace | |
2408 | ||
2409 | gimple_opt_pass * | |
2410 | make_pass_cselim (gcc::context *ctxt) | |
2411 | { | |
2412 | return new pass_cselim (ctxt); | |
2413 | } |