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4ee9c684 | 1 | /* Optimization of PHI nodes by converting them into straightline code. |
711789cc | 2 | Copyright (C) 2004-2013 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" | |
d9dd21a8 | 23 | #include "hash-table.h" |
4ee9c684 | 24 | #include "tm.h" |
4ee9c684 | 25 | #include "ggc.h" |
26 | #include "tree.h" | |
0beac6fc | 27 | #include "flags.h" |
4ee9c684 | 28 | #include "tm_p.h" |
29 | #include "basic-block.h" | |
4ee9c684 | 30 | #include "tree-flow.h" |
31 | #include "tree-pass.h" | |
4ee9c684 | 32 | #include "langhooks.h" |
e6d0e152 | 33 | #include "pointer-set.h" |
34 | #include "domwalk.h" | |
ec611e12 | 35 | #include "cfgloop.h" |
36 | #include "tree-data-ref.h" | |
239e9670 | 37 | #include "gimple-pretty-print.h" |
38 | #include "insn-config.h" | |
39 | #include "expr.h" | |
40 | #include "optabs.h" | |
f6568ea4 | 41 | #include "tree-scalar-evolution.h" |
239e9670 | 42 | |
43 | #ifndef HAVE_conditional_move | |
44 | #define HAVE_conditional_move (0) | |
45 | #endif | |
4ee9c684 | 46 | |
75a70cf9 | 47 | static unsigned int tree_ssa_phiopt (void); |
239e9670 | 48 | static unsigned int tree_ssa_phiopt_worker (bool, bool); |
a4844041 | 49 | static bool conditional_replacement (basic_block, basic_block, |
75a70cf9 | 50 | edge, edge, gimple, tree, tree); |
fb9912ea | 51 | static int value_replacement (basic_block, basic_block, |
52 | edge, edge, gimple, tree, tree); | |
a4844041 | 53 | static bool minmax_replacement (basic_block, basic_block, |
75a70cf9 | 54 | edge, edge, gimple, tree, tree); |
a4844041 | 55 | static bool abs_replacement (basic_block, basic_block, |
75a70cf9 | 56 | edge, edge, gimple, tree, tree); |
e6d0e152 | 57 | static bool cond_store_replacement (basic_block, basic_block, edge, edge, |
58 | struct pointer_set_t *); | |
91cf53d5 | 59 | static bool cond_if_else_store_replacement (basic_block, basic_block, basic_block); |
e6d0e152 | 60 | static struct pointer_set_t * get_non_trapping (void); |
75a70cf9 | 61 | static void replace_phi_edge_with_variable (basic_block, edge, gimple, tree); |
239e9670 | 62 | static void hoist_adjacent_loads (basic_block, basic_block, |
63 | basic_block, basic_block); | |
64 | static bool gate_hoist_loads (void); | |
902929aa | 65 | |
caac37c2 | 66 | /* This pass tries to replaces an if-then-else block with an |
67 | assignment. We have four kinds of transformations. Some of these | |
68 | transformations are also performed by the ifcvt RTL optimizer. | |
69 | ||
70 | Conditional Replacement | |
71 | ----------------------- | |
72 | ||
30c5ffd2 | 73 | This transformation, implemented in conditional_replacement, |
caac37c2 | 74 | replaces |
4ee9c684 | 75 | |
76 | bb0: | |
77 | if (cond) goto bb2; else goto bb1; | |
78 | bb1: | |
79 | bb2: | |
caac37c2 | 80 | x = PHI <0 (bb1), 1 (bb0), ...>; |
4ee9c684 | 81 | |
caac37c2 | 82 | with |
20e5647c | 83 | |
2ab0a163 | 84 | bb0: |
caac37c2 | 85 | x' = cond; |
86 | goto bb2; | |
2ab0a163 | 87 | bb2: |
caac37c2 | 88 | x = PHI <x' (bb0), ...>; |
4ee9c684 | 89 | |
caac37c2 | 90 | We remove bb1 as it becomes unreachable. This occurs often due to |
91 | gimplification of conditionals. | |
20e5647c | 92 | |
caac37c2 | 93 | Value Replacement |
94 | ----------------- | |
95 | ||
96 | This transformation, implemented in value_replacement, replaces | |
0beac6fc | 97 | |
98 | bb0: | |
caac37c2 | 99 | if (a != b) goto bb2; else goto bb1; |
0beac6fc | 100 | bb1: |
101 | bb2: | |
caac37c2 | 102 | x = PHI <a (bb1), b (bb0), ...>; |
0beac6fc | 103 | |
caac37c2 | 104 | with |
0beac6fc | 105 | |
106 | bb0: | |
0beac6fc | 107 | bb2: |
caac37c2 | 108 | x = PHI <b (bb0), ...>; |
109 | ||
110 | This opportunity can sometimes occur as a result of other | |
111 | optimizations. | |
0beac6fc | 112 | |
caac37c2 | 113 | ABS Replacement |
114 | --------------- | |
70512b93 | 115 | |
caac37c2 | 116 | This transformation, implemented in abs_replacement, replaces |
70512b93 | 117 | |
118 | bb0: | |
caac37c2 | 119 | if (a >= 0) goto bb2; else goto bb1; |
70512b93 | 120 | bb1: |
caac37c2 | 121 | x = -a; |
70512b93 | 122 | bb2: |
caac37c2 | 123 | x = PHI <x (bb1), a (bb0), ...>; |
70512b93 | 124 | |
caac37c2 | 125 | with |
70512b93 | 126 | |
127 | bb0: | |
caac37c2 | 128 | x' = ABS_EXPR< a >; |
70512b93 | 129 | bb2: |
caac37c2 | 130 | x = PHI <x' (bb0), ...>; |
131 | ||
132 | MIN/MAX Replacement | |
133 | ------------------- | |
70512b93 | 134 | |
caac37c2 | 135 | This transformation, minmax_replacement replaces |
194899bf | 136 | |
137 | bb0: | |
caac37c2 | 138 | if (a <= b) goto bb2; else goto bb1; |
194899bf | 139 | bb1: |
194899bf | 140 | bb2: |
caac37c2 | 141 | x = PHI <b (bb1), a (bb0), ...>; |
194899bf | 142 | |
caac37c2 | 143 | with |
194899bf | 144 | |
caac37c2 | 145 | bb0: |
146 | x' = MIN_EXPR (a, b) | |
147 | bb2: | |
148 | x = PHI <x' (bb0), ...>; | |
194899bf | 149 | |
239e9670 | 150 | A similar transformation is done for MAX_EXPR. |
151 | ||
152 | ||
153 | This pass also performs a fifth transformation of a slightly different | |
154 | flavor. | |
155 | ||
156 | Adjacent Load Hoisting | |
157 | ---------------------- | |
158 | ||
159 | This transformation replaces | |
160 | ||
161 | bb0: | |
162 | if (...) goto bb2; else goto bb1; | |
163 | bb1: | |
164 | x1 = (<expr>).field1; | |
165 | goto bb3; | |
166 | bb2: | |
167 | x2 = (<expr>).field2; | |
168 | bb3: | |
169 | # x = PHI <x1, x2>; | |
170 | ||
171 | with | |
172 | ||
173 | bb0: | |
174 | x1 = (<expr>).field1; | |
175 | x2 = (<expr>).field2; | |
176 | if (...) goto bb2; else goto bb1; | |
177 | bb1: | |
178 | goto bb3; | |
179 | bb2: | |
180 | bb3: | |
181 | # x = PHI <x1, x2>; | |
182 | ||
183 | The purpose of this transformation is to enable generation of conditional | |
184 | move instructions such as Intel CMOVE or PowerPC ISEL. Because one of | |
185 | the loads is speculative, the transformation is restricted to very | |
186 | specific cases to avoid introducing a page fault. We are looking for | |
187 | the common idiom: | |
188 | ||
189 | if (...) | |
190 | x = y->left; | |
191 | else | |
192 | x = y->right; | |
193 | ||
194 | where left and right are typically adjacent pointers in a tree structure. */ | |
70512b93 | 195 | |
2a1990e9 | 196 | static unsigned int |
4ee9c684 | 197 | tree_ssa_phiopt (void) |
e6d0e152 | 198 | { |
239e9670 | 199 | return tree_ssa_phiopt_worker (false, gate_hoist_loads ()); |
e6d0e152 | 200 | } |
201 | ||
202 | /* This pass tries to transform conditional stores into unconditional | |
203 | ones, enabling further simplifications with the simpler then and else | |
204 | blocks. In particular it replaces this: | |
205 | ||
206 | bb0: | |
207 | if (cond) goto bb2; else goto bb1; | |
208 | bb1: | |
91cf53d5 | 209 | *p = RHS; |
e6d0e152 | 210 | bb2: |
211 | ||
212 | with | |
213 | ||
214 | bb0: | |
215 | if (cond) goto bb1; else goto bb2; | |
216 | bb1: | |
217 | condtmp' = *p; | |
218 | bb2: | |
219 | condtmp = PHI <RHS, condtmp'> | |
91cf53d5 | 220 | *p = condtmp; |
e6d0e152 | 221 | |
222 | This transformation can only be done under several constraints, | |
91cf53d5 | 223 | documented below. It also replaces: |
224 | ||
225 | bb0: | |
226 | if (cond) goto bb2; else goto bb1; | |
227 | bb1: | |
228 | *p = RHS1; | |
229 | goto bb3; | |
230 | bb2: | |
231 | *p = RHS2; | |
232 | bb3: | |
233 | ||
234 | with | |
235 | ||
236 | bb0: | |
237 | if (cond) goto bb3; else goto bb1; | |
238 | bb1: | |
239 | bb3: | |
240 | condtmp = PHI <RHS1, RHS2> | |
241 | *p = condtmp; */ | |
e6d0e152 | 242 | |
243 | static unsigned int | |
244 | tree_ssa_cs_elim (void) | |
245 | { | |
f6568ea4 | 246 | unsigned todo; |
247 | /* ??? We are not interested in loop related info, but the following | |
248 | will create it, ICEing as we didn't init loops with pre-headers. | |
249 | An interfacing issue of find_data_references_in_bb. */ | |
250 | loop_optimizer_init (LOOPS_NORMAL); | |
251 | scev_initialize (); | |
252 | todo = tree_ssa_phiopt_worker (true, false); | |
253 | scev_finalize (); | |
254 | loop_optimizer_finalize (); | |
255 | return todo; | |
e6d0e152 | 256 | } |
257 | ||
c3597b05 | 258 | /* Return the singleton PHI in the SEQ of PHIs for edges E0 and E1. */ |
259 | ||
260 | static gimple | |
261 | single_non_singleton_phi_for_edges (gimple_seq seq, edge e0, edge e1) | |
262 | { | |
263 | gimple_stmt_iterator i; | |
264 | gimple phi = NULL; | |
265 | if (gimple_seq_singleton_p (seq)) | |
266 | return gsi_stmt (gsi_start (seq)); | |
267 | for (i = gsi_start (seq); !gsi_end_p (i); gsi_next (&i)) | |
268 | { | |
269 | gimple p = gsi_stmt (i); | |
270 | /* If the PHI arguments are equal then we can skip this PHI. */ | |
271 | if (operand_equal_for_phi_arg_p (gimple_phi_arg_def (p, e0->dest_idx), | |
272 | gimple_phi_arg_def (p, e1->dest_idx))) | |
273 | continue; | |
274 | ||
275 | /* If we already have a PHI that has the two edge arguments are | |
276 | different, then return it is not a singleton for these PHIs. */ | |
277 | if (phi) | |
278 | return NULL; | |
279 | ||
280 | phi = p; | |
281 | } | |
282 | return phi; | |
283 | } | |
284 | ||
e6d0e152 | 285 | /* The core routine of conditional store replacement and normal |
286 | phi optimizations. Both share much of the infrastructure in how | |
287 | to match applicable basic block patterns. DO_STORE_ELIM is true | |
239e9670 | 288 | when we want to do conditional store replacement, false otherwise. |
289 | DO_HOIST_LOADS is true when we want to hoist adjacent loads out | |
290 | of diamond control flow patterns, false otherwise. */ | |
e6d0e152 | 291 | static unsigned int |
239e9670 | 292 | tree_ssa_phiopt_worker (bool do_store_elim, bool do_hoist_loads) |
4ee9c684 | 293 | { |
294 | basic_block bb; | |
194899bf | 295 | basic_block *bb_order; |
296 | unsigned n, i; | |
1e4b21e3 | 297 | bool cfgchanged = false; |
e6d0e152 | 298 | struct pointer_set_t *nontrap = 0; |
299 | ||
300 | if (do_store_elim) | |
03d37e4e | 301 | /* Calculate the set of non-trapping memory accesses. */ |
302 | nontrap = get_non_trapping (); | |
194899bf | 303 | |
304 | /* Search every basic block for COND_EXPR we may be able to optimize. | |
305 | ||
306 | We walk the blocks in order that guarantees that a block with | |
307 | a single predecessor is processed before the predecessor. | |
308 | This ensures that we collapse inner ifs before visiting the | |
309 | outer ones, and also that we do not try to visit a removed | |
310 | block. */ | |
311 | bb_order = blocks_in_phiopt_order (); | |
4d2e5d52 | 312 | n = n_basic_blocks - NUM_FIXED_BLOCKS; |
4ee9c684 | 313 | |
48e1416a | 314 | for (i = 0; i < n; i++) |
4ee9c684 | 315 | { |
75a70cf9 | 316 | gimple cond_stmt, phi; |
33784d89 | 317 | basic_block bb1, bb2; |
318 | edge e1, e2; | |
194899bf | 319 | tree arg0, arg1; |
320 | ||
321 | bb = bb_order[i]; | |
20e5647c | 322 | |
75a70cf9 | 323 | cond_stmt = last_stmt (bb); |
324 | /* Check to see if the last statement is a GIMPLE_COND. */ | |
325 | if (!cond_stmt | |
326 | || gimple_code (cond_stmt) != GIMPLE_COND) | |
33784d89 | 327 | continue; |
20e5647c | 328 | |
33784d89 | 329 | e1 = EDGE_SUCC (bb, 0); |
330 | bb1 = e1->dest; | |
331 | e2 = EDGE_SUCC (bb, 1); | |
332 | bb2 = e2->dest; | |
20e5647c | 333 | |
33784d89 | 334 | /* We cannot do the optimization on abnormal edges. */ |
335 | if ((e1->flags & EDGE_ABNORMAL) != 0 | |
336 | || (e2->flags & EDGE_ABNORMAL) != 0) | |
337 | continue; | |
20e5647c | 338 | |
33784d89 | 339 | /* If either bb1's succ or bb2 or bb2's succ is non NULL. */ |
ea091dfd | 340 | if (EDGE_COUNT (bb1->succs) == 0 |
33784d89 | 341 | || bb2 == NULL |
ea091dfd | 342 | || EDGE_COUNT (bb2->succs) == 0) |
33784d89 | 343 | continue; |
20e5647c | 344 | |
33784d89 | 345 | /* Find the bb which is the fall through to the other. */ |
346 | if (EDGE_SUCC (bb1, 0)->dest == bb2) | |
347 | ; | |
348 | else if (EDGE_SUCC (bb2, 0)->dest == bb1) | |
349 | { | |
350 | basic_block bb_tmp = bb1; | |
351 | edge e_tmp = e1; | |
352 | bb1 = bb2; | |
353 | bb2 = bb_tmp; | |
354 | e1 = e2; | |
355 | e2 = e_tmp; | |
356 | } | |
91cf53d5 | 357 | else if (do_store_elim |
358 | && EDGE_SUCC (bb1, 0)->dest == EDGE_SUCC (bb2, 0)->dest) | |
359 | { | |
360 | basic_block bb3 = EDGE_SUCC (bb1, 0)->dest; | |
361 | ||
362 | if (!single_succ_p (bb1) | |
363 | || (EDGE_SUCC (bb1, 0)->flags & EDGE_FALLTHRU) == 0 | |
364 | || !single_succ_p (bb2) | |
365 | || (EDGE_SUCC (bb2, 0)->flags & EDGE_FALLTHRU) == 0 | |
366 | || EDGE_COUNT (bb3->preds) != 2) | |
367 | continue; | |
368 | if (cond_if_else_store_replacement (bb1, bb2, bb3)) | |
369 | cfgchanged = true; | |
370 | continue; | |
371 | } | |
239e9670 | 372 | else if (do_hoist_loads |
373 | && EDGE_SUCC (bb1, 0)->dest == EDGE_SUCC (bb2, 0)->dest) | |
374 | { | |
375 | basic_block bb3 = EDGE_SUCC (bb1, 0)->dest; | |
376 | ||
377 | if (!FLOAT_TYPE_P (TREE_TYPE (gimple_cond_lhs (cond_stmt))) | |
378 | && single_succ_p (bb1) | |
379 | && single_succ_p (bb2) | |
380 | && single_pred_p (bb1) | |
381 | && single_pred_p (bb2) | |
382 | && EDGE_COUNT (bb->succs) == 2 | |
383 | && EDGE_COUNT (bb3->preds) == 2 | |
384 | /* If one edge or the other is dominant, a conditional move | |
385 | is likely to perform worse than the well-predicted branch. */ | |
386 | && !predictable_edge_p (EDGE_SUCC (bb, 0)) | |
387 | && !predictable_edge_p (EDGE_SUCC (bb, 1))) | |
388 | hoist_adjacent_loads (bb, bb1, bb2, bb3); | |
389 | continue; | |
390 | } | |
33784d89 | 391 | else |
91cf53d5 | 392 | continue; |
20e5647c | 393 | |
33784d89 | 394 | e1 = EDGE_SUCC (bb1, 0); |
20e5647c | 395 | |
33784d89 | 396 | /* Make sure that bb1 is just a fall through. */ |
db5ba14c | 397 | if (!single_succ_p (bb1) |
33784d89 | 398 | || (e1->flags & EDGE_FALLTHRU) == 0) |
399 | continue; | |
20e5647c | 400 | |
3472707f | 401 | /* Also make sure that bb1 only have one predecessor and that it |
402 | is bb. */ | |
ea091dfd | 403 | if (!single_pred_p (bb1) |
404 | || single_pred (bb1) != bb) | |
33784d89 | 405 | continue; |
20e5647c | 406 | |
e6d0e152 | 407 | if (do_store_elim) |
408 | { | |
409 | /* bb1 is the middle block, bb2 the join block, bb the split block, | |
410 | e1 the fallthrough edge from bb1 to bb2. We can't do the | |
411 | optimization if the join block has more than two predecessors. */ | |
412 | if (EDGE_COUNT (bb2->preds) > 2) | |
413 | continue; | |
414 | if (cond_store_replacement (bb1, bb2, e1, e2, nontrap)) | |
415 | cfgchanged = true; | |
416 | } | |
417 | else | |
418 | { | |
75a70cf9 | 419 | gimple_seq phis = phi_nodes (bb2); |
2109076a | 420 | gimple_stmt_iterator gsi; |
fb9912ea | 421 | bool candorest = true; |
c3597b05 | 422 | |
fb9912ea | 423 | /* Value replacement can work with more than one PHI |
424 | so try that first. */ | |
425 | for (gsi = gsi_start (phis); !gsi_end_p (gsi); gsi_next (&gsi)) | |
426 | { | |
427 | phi = gsi_stmt (gsi); | |
428 | arg0 = gimple_phi_arg_def (phi, e1->dest_idx); | |
429 | arg1 = gimple_phi_arg_def (phi, e2->dest_idx); | |
430 | if (value_replacement (bb, bb1, e1, e2, phi, arg0, arg1) == 2) | |
431 | { | |
432 | candorest = false; | |
433 | cfgchanged = true; | |
434 | break; | |
435 | } | |
436 | } | |
e6d0e152 | 437 | |
fb9912ea | 438 | if (!candorest) |
439 | continue; | |
c3597b05 | 440 | |
441 | phi = single_non_singleton_phi_for_edges (phis, e1, e2); | |
2109076a | 442 | if (!phi) |
e6d0e152 | 443 | continue; |
444 | ||
75a70cf9 | 445 | arg0 = gimple_phi_arg_def (phi, e1->dest_idx); |
446 | arg1 = gimple_phi_arg_def (phi, e2->dest_idx); | |
e6d0e152 | 447 | |
448 | /* Something is wrong if we cannot find the arguments in the PHI | |
449 | node. */ | |
450 | gcc_assert (arg0 != NULL && arg1 != NULL); | |
451 | ||
452 | /* Do the replacement of conditional if it can be done. */ | |
453 | if (conditional_replacement (bb, bb1, e1, e2, phi, arg0, arg1)) | |
454 | cfgchanged = true; | |
e6d0e152 | 455 | else if (abs_replacement (bb, bb1, e1, e2, phi, arg0, arg1)) |
456 | cfgchanged = true; | |
457 | else if (minmax_replacement (bb, bb1, e1, e2, phi, arg0, arg1)) | |
458 | cfgchanged = true; | |
459 | } | |
194899bf | 460 | } |
461 | ||
462 | free (bb_order); | |
48e1416a | 463 | |
e6d0e152 | 464 | if (do_store_elim) |
465 | pointer_set_destroy (nontrap); | |
466 | /* If the CFG has changed, we should cleanup the CFG. */ | |
467 | if (cfgchanged && do_store_elim) | |
468 | { | |
469 | /* In cond-store replacement we have added some loads on edges | |
470 | and new VOPS (as we moved the store, and created a load). */ | |
75a70cf9 | 471 | gsi_commit_edge_inserts (); |
e6d0e152 | 472 | return TODO_cleanup_cfg | TODO_update_ssa_only_virtuals; |
473 | } | |
474 | else if (cfgchanged) | |
475 | return TODO_cleanup_cfg; | |
476 | return 0; | |
194899bf | 477 | } |
478 | ||
479 | /* Returns the list of basic blocks in the function in an order that guarantees | |
480 | that if a block X has just a single predecessor Y, then Y is after X in the | |
481 | ordering. */ | |
482 | ||
8530c7be | 483 | basic_block * |
194899bf | 484 | blocks_in_phiopt_order (void) |
485 | { | |
486 | basic_block x, y; | |
945865c5 | 487 | basic_block *order = XNEWVEC (basic_block, n_basic_blocks); |
48e1416a | 488 | unsigned n = n_basic_blocks - NUM_FIXED_BLOCKS; |
4d2e5d52 | 489 | unsigned np, i; |
48e1416a | 490 | sbitmap visited = sbitmap_alloc (last_basic_block); |
194899bf | 491 | |
08b7917c | 492 | #define MARK_VISITED(BB) (bitmap_set_bit (visited, (BB)->index)) |
493 | #define VISITED_P(BB) (bitmap_bit_p (visited, (BB)->index)) | |
194899bf | 494 | |
53c5d9d4 | 495 | bitmap_clear (visited); |
194899bf | 496 | |
497 | MARK_VISITED (ENTRY_BLOCK_PTR); | |
498 | FOR_EACH_BB (x) | |
499 | { | |
500 | if (VISITED_P (x)) | |
501 | continue; | |
502 | ||
503 | /* Walk the predecessors of x as long as they have precisely one | |
504 | predecessor and add them to the list, so that they get stored | |
505 | after x. */ | |
506 | for (y = x, np = 1; | |
507 | single_pred_p (y) && !VISITED_P (single_pred (y)); | |
508 | y = single_pred (y)) | |
509 | np++; | |
510 | for (y = x, i = n - np; | |
511 | single_pred_p (y) && !VISITED_P (single_pred (y)); | |
512 | y = single_pred (y), i++) | |
513 | { | |
514 | order[i] = y; | |
515 | MARK_VISITED (y); | |
2ab0a163 | 516 | } |
194899bf | 517 | order[i] = y; |
518 | MARK_VISITED (y); | |
519 | ||
520 | gcc_assert (i == n - 1); | |
521 | n -= np; | |
4ee9c684 | 522 | } |
194899bf | 523 | |
524 | sbitmap_free (visited); | |
525 | gcc_assert (n == 0); | |
526 | return order; | |
527 | ||
528 | #undef MARK_VISITED | |
529 | #undef VISITED_P | |
4ee9c684 | 530 | } |
531 | ||
fccee353 | 532 | /* Replace PHI node element whose edge is E in block BB with variable NEW. |
33784d89 | 533 | Remove the edge from COND_BLOCK which does not lead to BB (COND_BLOCK |
902929aa | 534 | is known to have two edges, one of which must reach BB). */ |
535 | ||
536 | static void | |
a4844041 | 537 | replace_phi_edge_with_variable (basic_block cond_block, |
75a70cf9 | 538 | edge e, gimple phi, tree new_tree) |
902929aa | 539 | { |
75a70cf9 | 540 | basic_block bb = gimple_bb (phi); |
0e1a77e1 | 541 | basic_block block_to_remove; |
75a70cf9 | 542 | gimple_stmt_iterator gsi; |
33784d89 | 543 | |
20e5647c | 544 | /* Change the PHI argument to new. */ |
f0d6e81c | 545 | SET_USE (PHI_ARG_DEF_PTR (phi, e->dest_idx), new_tree); |
0e1a77e1 | 546 | |
0e1a77e1 | 547 | /* Remove the empty basic block. */ |
cd665a06 | 548 | if (EDGE_SUCC (cond_block, 0)->dest == bb) |
902929aa | 549 | { |
cd665a06 | 550 | EDGE_SUCC (cond_block, 0)->flags |= EDGE_FALLTHRU; |
551 | EDGE_SUCC (cond_block, 0)->flags &= ~(EDGE_TRUE_VALUE | EDGE_FALSE_VALUE); | |
81c5be57 | 552 | EDGE_SUCC (cond_block, 0)->probability = REG_BR_PROB_BASE; |
553 | EDGE_SUCC (cond_block, 0)->count += EDGE_SUCC (cond_block, 1)->count; | |
0e1a77e1 | 554 | |
cd665a06 | 555 | block_to_remove = EDGE_SUCC (cond_block, 1)->dest; |
902929aa | 556 | } |
557 | else | |
558 | { | |
cd665a06 | 559 | EDGE_SUCC (cond_block, 1)->flags |= EDGE_FALLTHRU; |
560 | EDGE_SUCC (cond_block, 1)->flags | |
902929aa | 561 | &= ~(EDGE_TRUE_VALUE | EDGE_FALSE_VALUE); |
81c5be57 | 562 | EDGE_SUCC (cond_block, 1)->probability = REG_BR_PROB_BASE; |
563 | EDGE_SUCC (cond_block, 1)->count += EDGE_SUCC (cond_block, 0)->count; | |
0e1a77e1 | 564 | |
cd665a06 | 565 | block_to_remove = EDGE_SUCC (cond_block, 0)->dest; |
902929aa | 566 | } |
0e1a77e1 | 567 | delete_basic_block (block_to_remove); |
20e5647c | 568 | |
902929aa | 569 | /* Eliminate the COND_EXPR at the end of COND_BLOCK. */ |
75a70cf9 | 570 | gsi = gsi_last_bb (cond_block); |
571 | gsi_remove (&gsi, true); | |
20e5647c | 572 | |
902929aa | 573 | if (dump_file && (dump_flags & TDF_DETAILS)) |
574 | fprintf (dump_file, | |
575 | "COND_EXPR in block %d and PHI in block %d converted to straightline code.\n", | |
576 | cond_block->index, | |
577 | bb->index); | |
578 | } | |
579 | ||
580 | /* The function conditional_replacement does the main work of doing the | |
581 | conditional replacement. Return true if the replacement is done. | |
582 | Otherwise return false. | |
583 | BB is the basic block where the replacement is going to be done on. ARG0 | |
dac49aa5 | 584 | is argument 0 from PHI. Likewise for ARG1. */ |
902929aa | 585 | |
586 | static bool | |
33784d89 | 587 | conditional_replacement (basic_block cond_bb, basic_block middle_bb, |
75a70cf9 | 588 | edge e0, edge e1, gimple phi, |
33784d89 | 589 | tree arg0, tree arg1) |
902929aa | 590 | { |
591 | tree result; | |
75a70cf9 | 592 | gimple stmt, new_stmt; |
593 | tree cond; | |
594 | gimple_stmt_iterator gsi; | |
902929aa | 595 | edge true_edge, false_edge; |
75a70cf9 | 596 | tree new_var, new_var2; |
678919fd | 597 | bool neg; |
902929aa | 598 | |
435e1a75 | 599 | /* FIXME: Gimplification of complex type is too hard for now. */ |
47b88316 | 600 | /* We aren't prepared to handle vectors either (and it is a question |
601 | if it would be worthwhile anyway). */ | |
602 | if (!(INTEGRAL_TYPE_P (TREE_TYPE (arg0)) | |
603 | || POINTER_TYPE_P (TREE_TYPE (arg0))) | |
604 | || !(INTEGRAL_TYPE_P (TREE_TYPE (arg1)) | |
605 | || POINTER_TYPE_P (TREE_TYPE (arg1)))) | |
435e1a75 | 606 | return false; |
607 | ||
678919fd | 608 | /* The PHI arguments have the constants 0 and 1, or 0 and -1, then |
609 | convert it to the conditional. */ | |
902929aa | 610 | if ((integer_zerop (arg0) && integer_onep (arg1)) |
611 | || (integer_zerop (arg1) && integer_onep (arg0))) | |
678919fd | 612 | neg = false; |
613 | else if ((integer_zerop (arg0) && integer_all_onesp (arg1)) | |
614 | || (integer_zerop (arg1) && integer_all_onesp (arg0))) | |
615 | neg = true; | |
902929aa | 616 | else |
617 | return false; | |
20e5647c | 618 | |
33784d89 | 619 | if (!empty_block_p (middle_bb)) |
902929aa | 620 | return false; |
20e5647c | 621 | |
75a70cf9 | 622 | /* At this point we know we have a GIMPLE_COND with two successors. |
2ab0a163 | 623 | One successor is BB, the other successor is an empty block which |
624 | falls through into BB. | |
20e5647c | 625 | |
2ab0a163 | 626 | There is a single PHI node at the join point (BB) and its arguments |
678919fd | 627 | are constants (0, 1) or (0, -1). |
20e5647c | 628 | |
2ab0a163 | 629 | So, given the condition COND, and the two PHI arguments, we can |
20e5647c | 630 | rewrite this PHI into non-branching code: |
631 | ||
2ab0a163 | 632 | dest = (COND) or dest = COND' |
20e5647c | 633 | |
2ab0a163 | 634 | We use the condition as-is if the argument associated with the |
635 | true edge has the value one or the argument associated with the | |
636 | false edge as the value zero. Note that those conditions are not | |
75a70cf9 | 637 | the same since only one of the outgoing edges from the GIMPLE_COND |
2ab0a163 | 638 | will directly reach BB and thus be associated with an argument. */ |
ae5a4794 | 639 | |
75a70cf9 | 640 | stmt = last_stmt (cond_bb); |
641 | result = PHI_RESULT (phi); | |
b2a02a0e | 642 | |
75a70cf9 | 643 | /* To handle special cases like floating point comparison, it is easier and |
644 | less error-prone to build a tree and gimplify it on the fly though it is | |
645 | less efficient. */ | |
6f9714b3 | 646 | cond = fold_build2_loc (gimple_location (stmt), |
647 | gimple_cond_code (stmt), boolean_type_node, | |
648 | gimple_cond_lhs (stmt), gimple_cond_rhs (stmt)); | |
4ee9c684 | 649 | |
75a70cf9 | 650 | /* We need to know which is the true edge and which is the false |
651 | edge so that we know when to invert the condition below. */ | |
652 | extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge); | |
653 | if ((e0 == true_edge && integer_zerop (arg0)) | |
678919fd | 654 | || (e0 == false_edge && !integer_zerop (arg0)) |
75a70cf9 | 655 | || (e1 == true_edge && integer_zerop (arg1)) |
678919fd | 656 | || (e1 == false_edge && !integer_zerop (arg1))) |
6f9714b3 | 657 | cond = fold_build1_loc (gimple_location (stmt), |
678919fd | 658 | TRUTH_NOT_EXPR, TREE_TYPE (cond), cond); |
659 | ||
660 | if (neg) | |
661 | { | |
662 | cond = fold_convert_loc (gimple_location (stmt), | |
663 | TREE_TYPE (result), cond); | |
664 | cond = fold_build1_loc (gimple_location (stmt), | |
665 | NEGATE_EXPR, TREE_TYPE (cond), cond); | |
666 | } | |
75a70cf9 | 667 | |
668 | /* Insert our new statements at the end of conditional block before the | |
669 | COND_STMT. */ | |
670 | gsi = gsi_for_stmt (stmt); | |
671 | new_var = force_gimple_operand_gsi (&gsi, cond, true, NULL, true, | |
672 | GSI_SAME_STMT); | |
673 | ||
674 | if (!useless_type_conversion_p (TREE_TYPE (result), TREE_TYPE (new_var))) | |
675 | { | |
efbcb6de | 676 | source_location locus_0, locus_1; |
677 | ||
03d37e4e | 678 | new_var2 = make_ssa_name (TREE_TYPE (result), NULL); |
75a70cf9 | 679 | new_stmt = gimple_build_assign_with_ops (CONVERT_EXPR, new_var2, |
680 | new_var, NULL); | |
75a70cf9 | 681 | gsi_insert_before (&gsi, new_stmt, GSI_SAME_STMT); |
682 | new_var = new_var2; | |
efbcb6de | 683 | |
684 | /* Set the locus to the first argument, unless is doesn't have one. */ | |
685 | locus_0 = gimple_phi_arg_location (phi, 0); | |
686 | locus_1 = gimple_phi_arg_location (phi, 1); | |
687 | if (locus_0 == UNKNOWN_LOCATION) | |
688 | locus_0 = locus_1; | |
689 | gimple_set_location (new_stmt, locus_0); | |
4ee9c684 | 690 | } |
20e5647c | 691 | |
75a70cf9 | 692 | replace_phi_edge_with_variable (cond_bb, e1, phi, new_var); |
902929aa | 693 | |
4ee9c684 | 694 | /* Note that we optimized this PHI. */ |
695 | return true; | |
696 | } | |
697 | ||
17b9476e | 698 | /* Update *ARG which is defined in STMT so that it contains the |
699 | computed value if that seems profitable. Return true if the | |
700 | statement is made dead by that rewriting. */ | |
701 | ||
702 | static bool | |
703 | jump_function_from_stmt (tree *arg, gimple stmt) | |
704 | { | |
705 | enum tree_code code = gimple_assign_rhs_code (stmt); | |
706 | if (code == ADDR_EXPR) | |
707 | { | |
708 | /* For arg = &p->i transform it to p, if possible. */ | |
709 | tree rhs1 = gimple_assign_rhs1 (stmt); | |
710 | HOST_WIDE_INT offset; | |
711 | tree tem = get_addr_base_and_unit_offset (TREE_OPERAND (rhs1, 0), | |
712 | &offset); | |
713 | if (tem | |
714 | && TREE_CODE (tem) == MEM_REF | |
cf8f0e63 | 715 | && (mem_ref_offset (tem) + double_int::from_shwi (offset)).is_zero ()) |
17b9476e | 716 | { |
717 | *arg = TREE_OPERAND (tem, 0); | |
718 | return true; | |
719 | } | |
720 | } | |
721 | /* TODO: Much like IPA-CP jump-functions we want to handle constant | |
722 | additions symbolically here, and we'd need to update the comparison | |
723 | code that compares the arg + cst tuples in our caller. For now the | |
724 | code above exactly handles the VEC_BASE pattern from vec.h. */ | |
725 | return false; | |
726 | } | |
727 | ||
0beac6fc | 728 | /* The function value_replacement does the main work of doing the value |
fb9912ea | 729 | replacement. Return non-zero if the replacement is done. Otherwise return |
730 | 0. If we remove the middle basic block, return 2. | |
0beac6fc | 731 | BB is the basic block where the replacement is going to be done on. ARG0 |
dac49aa5 | 732 | is argument 0 from the PHI. Likewise for ARG1. */ |
0beac6fc | 733 | |
fb9912ea | 734 | static int |
33784d89 | 735 | value_replacement (basic_block cond_bb, basic_block middle_bb, |
75a70cf9 | 736 | edge e0, edge e1, gimple phi, |
33784d89 | 737 | tree arg0, tree arg1) |
0beac6fc | 738 | { |
17b9476e | 739 | gimple_stmt_iterator gsi; |
75a70cf9 | 740 | gimple cond; |
0beac6fc | 741 | edge true_edge, false_edge; |
75a70cf9 | 742 | enum tree_code code; |
fb9912ea | 743 | bool emtpy_or_with_defined_p = true; |
0beac6fc | 744 | |
745 | /* If the type says honor signed zeros we cannot do this | |
dac49aa5 | 746 | optimization. */ |
0beac6fc | 747 | if (HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1)))) |
fb9912ea | 748 | return 0; |
0beac6fc | 749 | |
fb9912ea | 750 | /* If there is a statement in MIDDLE_BB that defines one of the PHI |
751 | arguments, then adjust arg0 or arg1. */ | |
17b9476e | 752 | gsi = gsi_after_labels (middle_bb); |
fb9912ea | 753 | if (!gsi_end_p (gsi) && is_gimple_debug (gsi_stmt (gsi))) |
754 | gsi_next_nondebug (&gsi); | |
755 | while (!gsi_end_p (gsi)) | |
17b9476e | 756 | { |
fb9912ea | 757 | gimple stmt = gsi_stmt (gsi); |
758 | tree lhs; | |
759 | gsi_next_nondebug (&gsi); | |
760 | if (!is_gimple_assign (stmt)) | |
17b9476e | 761 | { |
fb9912ea | 762 | emtpy_or_with_defined_p = false; |
763 | continue; | |
17b9476e | 764 | } |
fb9912ea | 765 | /* Now try to adjust arg0 or arg1 according to the computation |
766 | in the statement. */ | |
767 | lhs = gimple_assign_lhs (stmt); | |
768 | if (!(lhs == arg0 | |
769 | && jump_function_from_stmt (&arg0, stmt)) | |
770 | || (lhs == arg1 | |
771 | && jump_function_from_stmt (&arg1, stmt))) | |
772 | emtpy_or_with_defined_p = false; | |
17b9476e | 773 | } |
0beac6fc | 774 | |
75a70cf9 | 775 | cond = last_stmt (cond_bb); |
776 | code = gimple_cond_code (cond); | |
0beac6fc | 777 | |
778 | /* This transformation is only valid for equality comparisons. */ | |
75a70cf9 | 779 | if (code != NE_EXPR && code != EQ_EXPR) |
fb9912ea | 780 | return 0; |
0beac6fc | 781 | |
782 | /* We need to know which is the true edge and which is the false | |
783 | edge so that we know if have abs or negative abs. */ | |
33784d89 | 784 | extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge); |
0beac6fc | 785 | |
786 | /* At this point we know we have a COND_EXPR with two successors. | |
787 | One successor is BB, the other successor is an empty block which | |
788 | falls through into BB. | |
789 | ||
790 | The condition for the COND_EXPR is known to be NE_EXPR or EQ_EXPR. | |
791 | ||
792 | There is a single PHI node at the join point (BB) with two arguments. | |
793 | ||
794 | We now need to verify that the two arguments in the PHI node match | |
795 | the two arguments to the equality comparison. */ | |
20e5647c | 796 | |
75a70cf9 | 797 | if ((operand_equal_for_phi_arg_p (arg0, gimple_cond_lhs (cond)) |
798 | && operand_equal_for_phi_arg_p (arg1, gimple_cond_rhs (cond))) | |
799 | || (operand_equal_for_phi_arg_p (arg1, gimple_cond_lhs (cond)) | |
800 | && operand_equal_for_phi_arg_p (arg0, gimple_cond_rhs (cond)))) | |
0beac6fc | 801 | { |
802 | edge e; | |
803 | tree arg; | |
804 | ||
50737d20 | 805 | /* For NE_EXPR, we want to build an assignment result = arg where |
806 | arg is the PHI argument associated with the true edge. For | |
807 | EQ_EXPR we want the PHI argument associated with the false edge. */ | |
75a70cf9 | 808 | e = (code == NE_EXPR ? true_edge : false_edge); |
50737d20 | 809 | |
810 | /* Unfortunately, E may not reach BB (it may instead have gone to | |
811 | OTHER_BLOCK). If that is the case, then we want the single outgoing | |
812 | edge from OTHER_BLOCK which reaches BB and represents the desired | |
813 | path from COND_BLOCK. */ | |
33784d89 | 814 | if (e->dest == middle_bb) |
ea091dfd | 815 | e = single_succ_edge (e->dest); |
50737d20 | 816 | |
817 | /* Now we know the incoming edge to BB that has the argument for the | |
818 | RHS of our new assignment statement. */ | |
33784d89 | 819 | if (e0 == e) |
0beac6fc | 820 | arg = arg0; |
821 | else | |
822 | arg = arg1; | |
823 | ||
fb9912ea | 824 | /* If the middle basic block was empty or is defining the |
c3597b05 | 825 | PHI arguments and this is a single phi where the args are different |
826 | for the edges e0 and e1 then we can remove the middle basic block. */ | |
fb9912ea | 827 | if (emtpy_or_with_defined_p |
c3597b05 | 828 | && single_non_singleton_phi_for_edges (phi_nodes (gimple_bb (phi)), |
829 | e0, e1)) | |
fb9912ea | 830 | { |
831 | replace_phi_edge_with_variable (cond_bb, e1, phi, arg); | |
832 | /* Note that we optimized this PHI. */ | |
833 | return 2; | |
834 | } | |
835 | else | |
836 | { | |
837 | /* Replace the PHI arguments with arg. */ | |
838 | SET_PHI_ARG_DEF (phi, e0->dest_idx, arg); | |
839 | SET_PHI_ARG_DEF (phi, e1->dest_idx, arg); | |
840 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
841 | { | |
842 | fprintf (dump_file, "PHI "); | |
843 | print_generic_expr (dump_file, gimple_phi_result (phi), 0); | |
c3597b05 | 844 | fprintf (dump_file, " reduced for COND_EXPR in block %d to ", |
845 | cond_bb->index); | |
fb9912ea | 846 | print_generic_expr (dump_file, arg, 0); |
847 | fprintf (dump_file, ".\n"); | |
848 | } | |
849 | return 1; | |
850 | } | |
0beac6fc | 851 | |
0beac6fc | 852 | } |
fb9912ea | 853 | return 0; |
0beac6fc | 854 | } |
855 | ||
194899bf | 856 | /* The function minmax_replacement does the main work of doing the minmax |
857 | replacement. Return true if the replacement is done. Otherwise return | |
858 | false. | |
859 | BB is the basic block where the replacement is going to be done on. ARG0 | |
860 | is argument 0 from the PHI. Likewise for ARG1. */ | |
861 | ||
862 | static bool | |
863 | minmax_replacement (basic_block cond_bb, basic_block middle_bb, | |
75a70cf9 | 864 | edge e0, edge e1, gimple phi, |
194899bf | 865 | tree arg0, tree arg1) |
866 | { | |
867 | tree result, type; | |
75a70cf9 | 868 | gimple cond, new_stmt; |
194899bf | 869 | edge true_edge, false_edge; |
870 | enum tree_code cmp, minmax, ass_code; | |
871 | tree smaller, larger, arg_true, arg_false; | |
75a70cf9 | 872 | gimple_stmt_iterator gsi, gsi_from; |
194899bf | 873 | |
874 | type = TREE_TYPE (PHI_RESULT (phi)); | |
875 | ||
876 | /* The optimization may be unsafe due to NaNs. */ | |
877 | if (HONOR_NANS (TYPE_MODE (type))) | |
878 | return false; | |
879 | ||
75a70cf9 | 880 | cond = last_stmt (cond_bb); |
881 | cmp = gimple_cond_code (cond); | |
194899bf | 882 | |
883 | /* This transformation is only valid for order comparisons. Record which | |
884 | operand is smaller/larger if the result of the comparison is true. */ | |
885 | if (cmp == LT_EXPR || cmp == LE_EXPR) | |
886 | { | |
75a70cf9 | 887 | smaller = gimple_cond_lhs (cond); |
888 | larger = gimple_cond_rhs (cond); | |
194899bf | 889 | } |
890 | else if (cmp == GT_EXPR || cmp == GE_EXPR) | |
891 | { | |
75a70cf9 | 892 | smaller = gimple_cond_rhs (cond); |
893 | larger = gimple_cond_lhs (cond); | |
194899bf | 894 | } |
895 | else | |
896 | return false; | |
897 | ||
898 | /* We need to know which is the true edge and which is the false | |
899 | edge so that we know if have abs or negative abs. */ | |
900 | extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge); | |
901 | ||
902 | /* Forward the edges over the middle basic block. */ | |
903 | if (true_edge->dest == middle_bb) | |
904 | true_edge = EDGE_SUCC (true_edge->dest, 0); | |
905 | if (false_edge->dest == middle_bb) | |
906 | false_edge = EDGE_SUCC (false_edge->dest, 0); | |
907 | ||
908 | if (true_edge == e0) | |
909 | { | |
910 | gcc_assert (false_edge == e1); | |
911 | arg_true = arg0; | |
912 | arg_false = arg1; | |
913 | } | |
914 | else | |
915 | { | |
916 | gcc_assert (false_edge == e0); | |
917 | gcc_assert (true_edge == e1); | |
918 | arg_true = arg1; | |
919 | arg_false = arg0; | |
920 | } | |
921 | ||
922 | if (empty_block_p (middle_bb)) | |
923 | { | |
924 | if (operand_equal_for_phi_arg_p (arg_true, smaller) | |
925 | && operand_equal_for_phi_arg_p (arg_false, larger)) | |
926 | { | |
927 | /* Case | |
48e1416a | 928 | |
194899bf | 929 | if (smaller < larger) |
930 | rslt = smaller; | |
931 | else | |
932 | rslt = larger; */ | |
933 | minmax = MIN_EXPR; | |
934 | } | |
935 | else if (operand_equal_for_phi_arg_p (arg_false, smaller) | |
936 | && operand_equal_for_phi_arg_p (arg_true, larger)) | |
937 | minmax = MAX_EXPR; | |
938 | else | |
939 | return false; | |
940 | } | |
941 | else | |
942 | { | |
943 | /* Recognize the following case, assuming d <= u: | |
944 | ||
945 | if (a <= u) | |
946 | b = MAX (a, d); | |
947 | x = PHI <b, u> | |
948 | ||
949 | This is equivalent to | |
950 | ||
951 | b = MAX (a, d); | |
952 | x = MIN (b, u); */ | |
953 | ||
75a70cf9 | 954 | gimple assign = last_and_only_stmt (middle_bb); |
955 | tree lhs, op0, op1, bound; | |
194899bf | 956 | |
957 | if (!assign | |
75a70cf9 | 958 | || gimple_code (assign) != GIMPLE_ASSIGN) |
194899bf | 959 | return false; |
960 | ||
75a70cf9 | 961 | lhs = gimple_assign_lhs (assign); |
962 | ass_code = gimple_assign_rhs_code (assign); | |
194899bf | 963 | if (ass_code != MAX_EXPR && ass_code != MIN_EXPR) |
964 | return false; | |
75a70cf9 | 965 | op0 = gimple_assign_rhs1 (assign); |
966 | op1 = gimple_assign_rhs2 (assign); | |
194899bf | 967 | |
968 | if (true_edge->src == middle_bb) | |
969 | { | |
970 | /* We got here if the condition is true, i.e., SMALLER < LARGER. */ | |
971 | if (!operand_equal_for_phi_arg_p (lhs, arg_true)) | |
972 | return false; | |
973 | ||
974 | if (operand_equal_for_phi_arg_p (arg_false, larger)) | |
975 | { | |
976 | /* Case | |
977 | ||
978 | if (smaller < larger) | |
979 | { | |
980 | r' = MAX_EXPR (smaller, bound) | |
981 | } | |
982 | r = PHI <r', larger> --> to be turned to MIN_EXPR. */ | |
983 | if (ass_code != MAX_EXPR) | |
984 | return false; | |
985 | ||
986 | minmax = MIN_EXPR; | |
987 | if (operand_equal_for_phi_arg_p (op0, smaller)) | |
988 | bound = op1; | |
989 | else if (operand_equal_for_phi_arg_p (op1, smaller)) | |
990 | bound = op0; | |
991 | else | |
992 | return false; | |
993 | ||
994 | /* We need BOUND <= LARGER. */ | |
49d00087 | 995 | if (!integer_nonzerop (fold_build2 (LE_EXPR, boolean_type_node, |
996 | bound, larger))) | |
194899bf | 997 | return false; |
998 | } | |
999 | else if (operand_equal_for_phi_arg_p (arg_false, smaller)) | |
1000 | { | |
1001 | /* Case | |
1002 | ||
1003 | if (smaller < larger) | |
1004 | { | |
1005 | r' = MIN_EXPR (larger, bound) | |
1006 | } | |
1007 | r = PHI <r', smaller> --> to be turned to MAX_EXPR. */ | |
1008 | if (ass_code != MIN_EXPR) | |
1009 | return false; | |
1010 | ||
1011 | minmax = MAX_EXPR; | |
1012 | if (operand_equal_for_phi_arg_p (op0, larger)) | |
1013 | bound = op1; | |
1014 | else if (operand_equal_for_phi_arg_p (op1, larger)) | |
1015 | bound = op0; | |
1016 | else | |
1017 | return false; | |
1018 | ||
1019 | /* We need BOUND >= SMALLER. */ | |
49d00087 | 1020 | if (!integer_nonzerop (fold_build2 (GE_EXPR, boolean_type_node, |
1021 | bound, smaller))) | |
194899bf | 1022 | return false; |
1023 | } | |
1024 | else | |
1025 | return false; | |
1026 | } | |
1027 | else | |
1028 | { | |
1029 | /* We got here if the condition is false, i.e., SMALLER > LARGER. */ | |
1030 | if (!operand_equal_for_phi_arg_p (lhs, arg_false)) | |
1031 | return false; | |
1032 | ||
1033 | if (operand_equal_for_phi_arg_p (arg_true, larger)) | |
1034 | { | |
1035 | /* Case | |
1036 | ||
1037 | if (smaller > larger) | |
1038 | { | |
1039 | r' = MIN_EXPR (smaller, bound) | |
1040 | } | |
1041 | r = PHI <r', larger> --> to be turned to MAX_EXPR. */ | |
1042 | if (ass_code != MIN_EXPR) | |
1043 | return false; | |
1044 | ||
1045 | minmax = MAX_EXPR; | |
1046 | if (operand_equal_for_phi_arg_p (op0, smaller)) | |
1047 | bound = op1; | |
1048 | else if (operand_equal_for_phi_arg_p (op1, smaller)) | |
1049 | bound = op0; | |
1050 | else | |
1051 | return false; | |
1052 | ||
1053 | /* We need BOUND >= LARGER. */ | |
49d00087 | 1054 | if (!integer_nonzerop (fold_build2 (GE_EXPR, boolean_type_node, |
1055 | bound, larger))) | |
194899bf | 1056 | return false; |
1057 | } | |
1058 | else if (operand_equal_for_phi_arg_p (arg_true, smaller)) | |
1059 | { | |
1060 | /* Case | |
1061 | ||
1062 | if (smaller > larger) | |
1063 | { | |
1064 | r' = MAX_EXPR (larger, bound) | |
1065 | } | |
1066 | r = PHI <r', smaller> --> to be turned to MIN_EXPR. */ | |
1067 | if (ass_code != MAX_EXPR) | |
1068 | return false; | |
1069 | ||
1070 | minmax = MIN_EXPR; | |
1071 | if (operand_equal_for_phi_arg_p (op0, larger)) | |
1072 | bound = op1; | |
1073 | else if (operand_equal_for_phi_arg_p (op1, larger)) | |
1074 | bound = op0; | |
1075 | else | |
1076 | return false; | |
1077 | ||
1078 | /* We need BOUND <= SMALLER. */ | |
49d00087 | 1079 | if (!integer_nonzerop (fold_build2 (LE_EXPR, boolean_type_node, |
1080 | bound, smaller))) | |
194899bf | 1081 | return false; |
1082 | } | |
1083 | else | |
1084 | return false; | |
1085 | } | |
1086 | ||
1087 | /* Move the statement from the middle block. */ | |
75a70cf9 | 1088 | gsi = gsi_last_bb (cond_bb); |
445a6ba5 | 1089 | gsi_from = gsi_last_nondebug_bb (middle_bb); |
75a70cf9 | 1090 | gsi_move_before (&gsi_from, &gsi); |
194899bf | 1091 | } |
1092 | ||
1093 | /* Emit the statement to compute min/max. */ | |
1094 | result = duplicate_ssa_name (PHI_RESULT (phi), NULL); | |
75a70cf9 | 1095 | new_stmt = gimple_build_assign_with_ops (minmax, result, arg0, arg1); |
1096 | gsi = gsi_last_bb (cond_bb); | |
1097 | gsi_insert_before (&gsi, new_stmt, GSI_NEW_STMT); | |
194899bf | 1098 | |
a4844041 | 1099 | replace_phi_edge_with_variable (cond_bb, e1, phi, result); |
194899bf | 1100 | return true; |
1101 | } | |
1102 | ||
70512b93 | 1103 | /* The function absolute_replacement does the main work of doing the absolute |
1104 | replacement. Return true if the replacement is done. Otherwise return | |
1105 | false. | |
1106 | bb is the basic block where the replacement is going to be done on. arg0 | |
f7f07c95 | 1107 | is argument 0 from the phi. Likewise for arg1. */ |
33784d89 | 1108 | |
70512b93 | 1109 | static bool |
33784d89 | 1110 | abs_replacement (basic_block cond_bb, basic_block middle_bb, |
a4844041 | 1111 | edge e0 ATTRIBUTE_UNUSED, edge e1, |
75a70cf9 | 1112 | gimple phi, tree arg0, tree arg1) |
70512b93 | 1113 | { |
1114 | tree result; | |
75a70cf9 | 1115 | gimple new_stmt, cond; |
1116 | gimple_stmt_iterator gsi; | |
70512b93 | 1117 | edge true_edge, false_edge; |
75a70cf9 | 1118 | gimple assign; |
70512b93 | 1119 | edge e; |
194899bf | 1120 | tree rhs, lhs; |
70512b93 | 1121 | bool negate; |
1122 | enum tree_code cond_code; | |
1123 | ||
1124 | /* If the type says honor signed zeros we cannot do this | |
dac49aa5 | 1125 | optimization. */ |
70512b93 | 1126 | if (HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1)))) |
1127 | return false; | |
1128 | ||
70512b93 | 1129 | /* OTHER_BLOCK must have only one executable statement which must have the |
1130 | form arg0 = -arg1 or arg1 = -arg0. */ | |
70512b93 | 1131 | |
194899bf | 1132 | assign = last_and_only_stmt (middle_bb); |
70512b93 | 1133 | /* If we did not find the proper negation assignment, then we can not |
1134 | optimize. */ | |
1135 | if (assign == NULL) | |
1136 | return false; | |
48e1416a | 1137 | |
194899bf | 1138 | /* If we got here, then we have found the only executable statement |
1139 | in OTHER_BLOCK. If it is anything other than arg = -arg1 or | |
1140 | arg1 = -arg0, then we can not optimize. */ | |
75a70cf9 | 1141 | if (gimple_code (assign) != GIMPLE_ASSIGN) |
194899bf | 1142 | return false; |
1143 | ||
75a70cf9 | 1144 | lhs = gimple_assign_lhs (assign); |
194899bf | 1145 | |
75a70cf9 | 1146 | if (gimple_assign_rhs_code (assign) != NEGATE_EXPR) |
194899bf | 1147 | return false; |
1148 | ||
75a70cf9 | 1149 | rhs = gimple_assign_rhs1 (assign); |
48e1416a | 1150 | |
194899bf | 1151 | /* The assignment has to be arg0 = -arg1 or arg1 = -arg0. */ |
1152 | if (!(lhs == arg0 && rhs == arg1) | |
1153 | && !(lhs == arg1 && rhs == arg0)) | |
1154 | return false; | |
70512b93 | 1155 | |
75a70cf9 | 1156 | cond = last_stmt (cond_bb); |
70512b93 | 1157 | result = PHI_RESULT (phi); |
1158 | ||
1159 | /* Only relationals comparing arg[01] against zero are interesting. */ | |
75a70cf9 | 1160 | cond_code = gimple_cond_code (cond); |
70512b93 | 1161 | if (cond_code != GT_EXPR && cond_code != GE_EXPR |
1162 | && cond_code != LT_EXPR && cond_code != LE_EXPR) | |
1163 | return false; | |
1164 | ||
dac49aa5 | 1165 | /* Make sure the conditional is arg[01] OP y. */ |
75a70cf9 | 1166 | if (gimple_cond_lhs (cond) != rhs) |
70512b93 | 1167 | return false; |
1168 | ||
75a70cf9 | 1169 | if (FLOAT_TYPE_P (TREE_TYPE (gimple_cond_rhs (cond))) |
1170 | ? real_zerop (gimple_cond_rhs (cond)) | |
1171 | : integer_zerop (gimple_cond_rhs (cond))) | |
70512b93 | 1172 | ; |
1173 | else | |
1174 | return false; | |
1175 | ||
1176 | /* We need to know which is the true edge and which is the false | |
1177 | edge so that we know if have abs or negative abs. */ | |
33784d89 | 1178 | extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge); |
70512b93 | 1179 | |
1180 | /* For GT_EXPR/GE_EXPR, if the true edge goes to OTHER_BLOCK, then we | |
1181 | will need to negate the result. Similarly for LT_EXPR/LE_EXPR if | |
1182 | the false edge goes to OTHER_BLOCK. */ | |
1183 | if (cond_code == GT_EXPR || cond_code == GE_EXPR) | |
1184 | e = true_edge; | |
1185 | else | |
1186 | e = false_edge; | |
20e5647c | 1187 | |
33784d89 | 1188 | if (e->dest == middle_bb) |
70512b93 | 1189 | negate = true; |
1190 | else | |
1191 | negate = false; | |
20e5647c | 1192 | |
33784d89 | 1193 | result = duplicate_ssa_name (result, NULL); |
20e5647c | 1194 | |
70512b93 | 1195 | if (negate) |
03d37e4e | 1196 | lhs = make_ssa_name (TREE_TYPE (result), NULL); |
70512b93 | 1197 | else |
1198 | lhs = result; | |
1199 | ||
dac49aa5 | 1200 | /* Build the modify expression with abs expression. */ |
75a70cf9 | 1201 | new_stmt = gimple_build_assign_with_ops (ABS_EXPR, lhs, rhs, NULL); |
70512b93 | 1202 | |
75a70cf9 | 1203 | gsi = gsi_last_bb (cond_bb); |
1204 | gsi_insert_before (&gsi, new_stmt, GSI_NEW_STMT); | |
70512b93 | 1205 | |
1206 | if (negate) | |
1207 | { | |
75a70cf9 | 1208 | /* Get the right GSI. We want to insert after the recently |
70512b93 | 1209 | added ABS_EXPR statement (which we know is the first statement |
1210 | in the block. */ | |
75a70cf9 | 1211 | new_stmt = gimple_build_assign_with_ops (NEGATE_EXPR, result, lhs, NULL); |
70512b93 | 1212 | |
75a70cf9 | 1213 | gsi_insert_after (&gsi, new_stmt, GSI_NEW_STMT); |
70512b93 | 1214 | } |
20e5647c | 1215 | |
a4844041 | 1216 | replace_phi_edge_with_variable (cond_bb, e1, phi, result); |
70512b93 | 1217 | |
1218 | /* Note that we optimized this PHI. */ | |
1219 | return true; | |
1220 | } | |
1221 | ||
e6d0e152 | 1222 | /* Auxiliary functions to determine the set of memory accesses which |
1223 | can't trap because they are preceded by accesses to the same memory | |
182cf5a9 | 1224 | portion. We do that for MEM_REFs, so we only need to track |
e6d0e152 | 1225 | the SSA_NAME of the pointer indirectly referenced. The algorithm |
1226 | simply is a walk over all instructions in dominator order. When | |
182cf5a9 | 1227 | we see an MEM_REF we determine if we've already seen a same |
e6d0e152 | 1228 | ref anywhere up to the root of the dominator tree. If we do the |
af4f74fa | 1229 | current access can't trap. If we don't see any dominating access |
e6d0e152 | 1230 | the current access might trap, but might also make later accesses |
af4f74fa | 1231 | non-trapping, so we remember it. We need to be careful with loads |
1232 | or stores, for instance a load might not trap, while a store would, | |
1233 | so if we see a dominating read access this doesn't mean that a later | |
1234 | write access would not trap. Hence we also need to differentiate the | |
1235 | type of access(es) seen. | |
1236 | ||
1237 | ??? We currently are very conservative and assume that a load might | |
1238 | trap even if a store doesn't (write-only memory). This probably is | |
1239 | overly conservative. */ | |
e6d0e152 | 1240 | |
182cf5a9 | 1241 | /* A hash-table of SSA_NAMEs, and in which basic block an MEM_REF |
e6d0e152 | 1242 | through it was seen, which would constitute a no-trap region for |
1243 | same accesses. */ | |
1244 | struct name_to_bb | |
1245 | { | |
963aee26 | 1246 | unsigned int ssa_name_ver; |
42540642 | 1247 | unsigned int phase; |
963aee26 | 1248 | bool store; |
1249 | HOST_WIDE_INT offset, size; | |
e6d0e152 | 1250 | basic_block bb; |
1251 | }; | |
1252 | ||
d9dd21a8 | 1253 | /* Hashtable helpers. */ |
1254 | ||
1255 | struct ssa_names_hasher : typed_free_remove <name_to_bb> | |
1256 | { | |
1257 | typedef name_to_bb value_type; | |
1258 | typedef name_to_bb compare_type; | |
1259 | static inline hashval_t hash (const value_type *); | |
1260 | static inline bool equal (const value_type *, const compare_type *); | |
1261 | }; | |
e6d0e152 | 1262 | |
42540642 | 1263 | /* Used for quick clearing of the hash-table when we see calls. |
1264 | Hash entries with phase < nt_call_phase are invalid. */ | |
1265 | static unsigned int nt_call_phase; | |
1266 | ||
182cf5a9 | 1267 | /* The set of MEM_REFs which can't trap. */ |
e6d0e152 | 1268 | static struct pointer_set_t *nontrap_set; |
1269 | ||
963aee26 | 1270 | /* The hash function. */ |
d9dd21a8 | 1271 | |
1272 | inline hashval_t | |
1273 | ssa_names_hasher::hash (const value_type *n) | |
e6d0e152 | 1274 | { |
963aee26 | 1275 | return n->ssa_name_ver ^ (((hashval_t) n->store) << 31) |
1276 | ^ (n->offset << 6) ^ (n->size << 3); | |
e6d0e152 | 1277 | } |
1278 | ||
963aee26 | 1279 | /* The equality function of *P1 and *P2. */ |
e6d0e152 | 1280 | |
d9dd21a8 | 1281 | inline bool |
1282 | ssa_names_hasher::equal (const value_type *n1, const compare_type *n2) | |
1283 | { | |
963aee26 | 1284 | return n1->ssa_name_ver == n2->ssa_name_ver |
1285 | && n1->store == n2->store | |
1286 | && n1->offset == n2->offset | |
1287 | && n1->size == n2->size; | |
e6d0e152 | 1288 | } |
1289 | ||
d9dd21a8 | 1290 | /* The hash table for remembering what we've seen. */ |
1291 | static hash_table <ssa_names_hasher> seen_ssa_names; | |
1292 | ||
f0b5f617 | 1293 | /* We see the expression EXP in basic block BB. If it's an interesting |
182cf5a9 | 1294 | expression (an MEM_REF through an SSA_NAME) possibly insert the |
af4f74fa | 1295 | expression into the set NONTRAP or the hash table of seen expressions. |
1296 | STORE is true if this expression is on the LHS, otherwise it's on | |
1297 | the RHS. */ | |
e6d0e152 | 1298 | static void |
af4f74fa | 1299 | add_or_mark_expr (basic_block bb, tree exp, |
1300 | struct pointer_set_t *nontrap, bool store) | |
e6d0e152 | 1301 | { |
963aee26 | 1302 | HOST_WIDE_INT size; |
1303 | ||
182cf5a9 | 1304 | if (TREE_CODE (exp) == MEM_REF |
963aee26 | 1305 | && TREE_CODE (TREE_OPERAND (exp, 0)) == SSA_NAME |
1306 | && host_integerp (TREE_OPERAND (exp, 1), 0) | |
1307 | && (size = int_size_in_bytes (TREE_TYPE (exp))) > 0) | |
e6d0e152 | 1308 | { |
1309 | tree name = TREE_OPERAND (exp, 0); | |
1310 | struct name_to_bb map; | |
d9dd21a8 | 1311 | name_to_bb **slot; |
af4f74fa | 1312 | struct name_to_bb *n2bb; |
e6d0e152 | 1313 | basic_block found_bb = 0; |
1314 | ||
182cf5a9 | 1315 | /* Try to find the last seen MEM_REF through the same |
e6d0e152 | 1316 | SSA_NAME, which can trap. */ |
963aee26 | 1317 | map.ssa_name_ver = SSA_NAME_VERSION (name); |
42540642 | 1318 | map.phase = 0; |
e6d0e152 | 1319 | map.bb = 0; |
af4f74fa | 1320 | map.store = store; |
963aee26 | 1321 | map.offset = tree_low_cst (TREE_OPERAND (exp, 1), 0); |
1322 | map.size = size; | |
1323 | ||
d9dd21a8 | 1324 | slot = seen_ssa_names.find_slot (&map, INSERT); |
1325 | n2bb = *slot; | |
42540642 | 1326 | if (n2bb && n2bb->phase >= nt_call_phase) |
af4f74fa | 1327 | found_bb = n2bb->bb; |
e6d0e152 | 1328 | |
182cf5a9 | 1329 | /* If we've found a trapping MEM_REF, _and_ it dominates EXP |
e6d0e152 | 1330 | (it's in a basic block on the path from us to the dominator root) |
1331 | then we can't trap. */ | |
42540642 | 1332 | if (found_bb && (((size_t)found_bb->aux) & 1) == 1) |
e6d0e152 | 1333 | { |
1334 | pointer_set_insert (nontrap, exp); | |
1335 | } | |
1336 | else | |
1337 | { | |
1338 | /* EXP might trap, so insert it into the hash table. */ | |
af4f74fa | 1339 | if (n2bb) |
e6d0e152 | 1340 | { |
42540642 | 1341 | n2bb->phase = nt_call_phase; |
af4f74fa | 1342 | n2bb->bb = bb; |
e6d0e152 | 1343 | } |
1344 | else | |
1345 | { | |
af4f74fa | 1346 | n2bb = XNEW (struct name_to_bb); |
963aee26 | 1347 | n2bb->ssa_name_ver = SSA_NAME_VERSION (name); |
42540642 | 1348 | n2bb->phase = nt_call_phase; |
af4f74fa | 1349 | n2bb->bb = bb; |
1350 | n2bb->store = store; | |
963aee26 | 1351 | n2bb->offset = map.offset; |
1352 | n2bb->size = size; | |
af4f74fa | 1353 | *slot = n2bb; |
e6d0e152 | 1354 | } |
1355 | } | |
1356 | } | |
1357 | } | |
1358 | ||
42540642 | 1359 | /* Return true when CALL is a call stmt that definitely doesn't |
1360 | free any memory or makes it unavailable otherwise. */ | |
e8d4d8a9 | 1361 | bool |
42540642 | 1362 | nonfreeing_call_p (gimple call) |
1363 | { | |
1364 | if (gimple_call_builtin_p (call, BUILT_IN_NORMAL) | |
1365 | && gimple_call_flags (call) & ECF_LEAF) | |
1366 | switch (DECL_FUNCTION_CODE (gimple_call_fndecl (call))) | |
1367 | { | |
1368 | /* Just in case these become ECF_LEAF in the future. */ | |
1369 | case BUILT_IN_FREE: | |
1370 | case BUILT_IN_TM_FREE: | |
1371 | case BUILT_IN_REALLOC: | |
1372 | case BUILT_IN_STACK_RESTORE: | |
1373 | return false; | |
1374 | default: | |
1375 | return true; | |
1376 | } | |
1377 | ||
1378 | return false; | |
1379 | } | |
1380 | ||
e6d0e152 | 1381 | /* Called by walk_dominator_tree, when entering the block BB. */ |
1382 | static void | |
1383 | nt_init_block (struct dom_walk_data *data ATTRIBUTE_UNUSED, basic_block bb) | |
1384 | { | |
42540642 | 1385 | edge e; |
1386 | edge_iterator ei; | |
75a70cf9 | 1387 | gimple_stmt_iterator gsi; |
42540642 | 1388 | |
1389 | /* If we haven't seen all our predecessors, clear the hash-table. */ | |
1390 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1391 | if ((((size_t)e->src->aux) & 2) == 0) | |
1392 | { | |
1393 | nt_call_phase++; | |
1394 | break; | |
1395 | } | |
1396 | ||
1397 | /* Mark this BB as being on the path to dominator root and as visited. */ | |
1398 | bb->aux = (void*)(1 | 2); | |
e6d0e152 | 1399 | |
1400 | /* And walk the statements in order. */ | |
75a70cf9 | 1401 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
e6d0e152 | 1402 | { |
75a70cf9 | 1403 | gimple stmt = gsi_stmt (gsi); |
e6d0e152 | 1404 | |
42540642 | 1405 | if (is_gimple_call (stmt) && !nonfreeing_call_p (stmt)) |
1406 | nt_call_phase++; | |
1407 | else if (gimple_assign_single_p (stmt) && !gimple_has_volatile_ops (stmt)) | |
e6d0e152 | 1408 | { |
75a70cf9 | 1409 | add_or_mark_expr (bb, gimple_assign_lhs (stmt), nontrap_set, true); |
1410 | add_or_mark_expr (bb, gimple_assign_rhs1 (stmt), nontrap_set, false); | |
e6d0e152 | 1411 | } |
1412 | } | |
1413 | } | |
1414 | ||
1415 | /* Called by walk_dominator_tree, when basic block BB is exited. */ | |
1416 | static void | |
1417 | nt_fini_block (struct dom_walk_data *data ATTRIBUTE_UNUSED, basic_block bb) | |
1418 | { | |
1419 | /* This BB isn't on the path to dominator root anymore. */ | |
42540642 | 1420 | bb->aux = (void*)2; |
e6d0e152 | 1421 | } |
1422 | ||
1423 | /* This is the entry point of gathering non trapping memory accesses. | |
1424 | It will do a dominator walk over the whole function, and it will | |
1425 | make use of the bb->aux pointers. It returns a set of trees | |
182cf5a9 | 1426 | (the MEM_REFs itself) which can't trap. */ |
e6d0e152 | 1427 | static struct pointer_set_t * |
1428 | get_non_trapping (void) | |
1429 | { | |
1430 | struct pointer_set_t *nontrap; | |
1431 | struct dom_walk_data walk_data; | |
1432 | ||
42540642 | 1433 | nt_call_phase = 0; |
e6d0e152 | 1434 | nontrap = pointer_set_create (); |
d9dd21a8 | 1435 | seen_ssa_names.create (128); |
e6d0e152 | 1436 | /* We're going to do a dominator walk, so ensure that we have |
1437 | dominance information. */ | |
1438 | calculate_dominance_info (CDI_DOMINATORS); | |
1439 | ||
1440 | /* Setup callbacks for the generic dominator tree walker. */ | |
1441 | nontrap_set = nontrap; | |
e6d0e152 | 1442 | walk_data.dom_direction = CDI_DOMINATORS; |
1443 | walk_data.initialize_block_local_data = NULL; | |
6bf320fb | 1444 | walk_data.before_dom_children = nt_init_block; |
1445 | walk_data.after_dom_children = nt_fini_block; | |
e6d0e152 | 1446 | walk_data.global_data = NULL; |
1447 | walk_data.block_local_data_size = 0; | |
e6d0e152 | 1448 | |
1449 | init_walk_dominator_tree (&walk_data); | |
1450 | walk_dominator_tree (&walk_data, ENTRY_BLOCK_PTR); | |
1451 | fini_walk_dominator_tree (&walk_data); | |
d9dd21a8 | 1452 | seen_ssa_names.dispose (); |
e6d0e152 | 1453 | |
42540642 | 1454 | clear_aux_for_blocks (); |
e6d0e152 | 1455 | return nontrap; |
1456 | } | |
1457 | ||
1458 | /* Do the main work of conditional store replacement. We already know | |
1459 | that the recognized pattern looks like so: | |
1460 | ||
1461 | split: | |
1462 | if (cond) goto MIDDLE_BB; else goto JOIN_BB (edge E1) | |
1463 | MIDDLE_BB: | |
1464 | something | |
1465 | fallthrough (edge E0) | |
1466 | JOIN_BB: | |
1467 | some more | |
1468 | ||
1469 | We check that MIDDLE_BB contains only one store, that that store | |
1470 | doesn't trap (not via NOTRAP, but via checking if an access to the same | |
1471 | memory location dominates us) and that the store has a "simple" RHS. */ | |
1472 | ||
1473 | static bool | |
1474 | cond_store_replacement (basic_block middle_bb, basic_block join_bb, | |
1475 | edge e0, edge e1, struct pointer_set_t *nontrap) | |
1476 | { | |
75a70cf9 | 1477 | gimple assign = last_and_only_stmt (middle_bb); |
03d37e4e | 1478 | tree lhs, rhs, name, name2; |
75a70cf9 | 1479 | gimple newphi, new_stmt; |
1480 | gimple_stmt_iterator gsi; | |
efbcb6de | 1481 | source_location locus; |
e6d0e152 | 1482 | |
1483 | /* Check if middle_bb contains of only one store. */ | |
1484 | if (!assign | |
6cc085b6 | 1485 | || !gimple_assign_single_p (assign) |
1486 | || gimple_has_volatile_ops (assign)) | |
e6d0e152 | 1487 | return false; |
1488 | ||
efbcb6de | 1489 | locus = gimple_location (assign); |
75a70cf9 | 1490 | lhs = gimple_assign_lhs (assign); |
1491 | rhs = gimple_assign_rhs1 (assign); | |
182cf5a9 | 1492 | if (TREE_CODE (lhs) != MEM_REF |
91cf53d5 | 1493 | || TREE_CODE (TREE_OPERAND (lhs, 0)) != SSA_NAME |
3211fa0a | 1494 | || !is_gimple_reg_type (TREE_TYPE (lhs))) |
e6d0e152 | 1495 | return false; |
91cf53d5 | 1496 | |
e6d0e152 | 1497 | /* Prove that we can move the store down. We could also check |
1498 | TREE_THIS_NOTRAP here, but in that case we also could move stores, | |
1499 | whose value is not available readily, which we want to avoid. */ | |
1500 | if (!pointer_set_contains (nontrap, lhs)) | |
1501 | return false; | |
1502 | ||
1503 | /* Now we've checked the constraints, so do the transformation: | |
1504 | 1) Remove the single store. */ | |
75a70cf9 | 1505 | gsi = gsi_for_stmt (assign); |
3211fa0a | 1506 | unlink_stmt_vdef (assign); |
75a70cf9 | 1507 | gsi_remove (&gsi, true); |
91cf53d5 | 1508 | release_defs (assign); |
e6d0e152 | 1509 | |
03d37e4e | 1510 | /* 2) Insert a load from the memory of the store to the temporary |
e6d0e152 | 1511 | on the edge which did not contain the store. */ |
1512 | lhs = unshare_expr (lhs); | |
03d37e4e | 1513 | name = make_temp_ssa_name (TREE_TYPE (lhs), NULL, "cstore"); |
1514 | new_stmt = gimple_build_assign (name, lhs); | |
efbcb6de | 1515 | gimple_set_location (new_stmt, locus); |
75a70cf9 | 1516 | gsi_insert_on_edge (e1, new_stmt); |
e6d0e152 | 1517 | |
03d37e4e | 1518 | /* 3) Create a PHI node at the join block, with one argument |
e6d0e152 | 1519 | holding the old RHS, and the other holding the temporary |
1520 | where we stored the old memory contents. */ | |
03d37e4e | 1521 | name2 = make_temp_ssa_name (TREE_TYPE (lhs), NULL, "cstore"); |
1522 | newphi = create_phi_node (name2, join_bb); | |
60d535d2 | 1523 | add_phi_arg (newphi, rhs, e0, locus); |
1524 | add_phi_arg (newphi, name, e1, locus); | |
e6d0e152 | 1525 | |
1526 | lhs = unshare_expr (lhs); | |
75a70cf9 | 1527 | new_stmt = gimple_build_assign (lhs, PHI_RESULT (newphi)); |
e6d0e152 | 1528 | |
03d37e4e | 1529 | /* 4) Insert that PHI node. */ |
75a70cf9 | 1530 | gsi = gsi_after_labels (join_bb); |
1531 | if (gsi_end_p (gsi)) | |
e6d0e152 | 1532 | { |
75a70cf9 | 1533 | gsi = gsi_last_bb (join_bb); |
1534 | gsi_insert_after (&gsi, new_stmt, GSI_NEW_STMT); | |
e6d0e152 | 1535 | } |
1536 | else | |
75a70cf9 | 1537 | gsi_insert_before (&gsi, new_stmt, GSI_NEW_STMT); |
e6d0e152 | 1538 | |
1539 | return true; | |
1540 | } | |
4ee9c684 | 1541 | |
ec611e12 | 1542 | /* Do the main work of conditional store replacement. */ |
91cf53d5 | 1543 | |
1544 | static bool | |
ec611e12 | 1545 | cond_if_else_store_replacement_1 (basic_block then_bb, basic_block else_bb, |
1546 | basic_block join_bb, gimple then_assign, | |
1547 | gimple else_assign) | |
91cf53d5 | 1548 | { |
03d37e4e | 1549 | tree lhs_base, lhs, then_rhs, else_rhs, name; |
91cf53d5 | 1550 | source_location then_locus, else_locus; |
1551 | gimple_stmt_iterator gsi; | |
1552 | gimple newphi, new_stmt; | |
1553 | ||
91cf53d5 | 1554 | if (then_assign == NULL |
1555 | || !gimple_assign_single_p (then_assign) | |
3c25489e | 1556 | || gimple_clobber_p (then_assign) |
6cc085b6 | 1557 | || gimple_has_volatile_ops (then_assign) |
91cf53d5 | 1558 | || else_assign == NULL |
3c25489e | 1559 | || !gimple_assign_single_p (else_assign) |
6cc085b6 | 1560 | || gimple_clobber_p (else_assign) |
1561 | || gimple_has_volatile_ops (else_assign)) | |
91cf53d5 | 1562 | return false; |
1563 | ||
1564 | lhs = gimple_assign_lhs (then_assign); | |
1565 | if (!is_gimple_reg_type (TREE_TYPE (lhs)) | |
1566 | || !operand_equal_p (lhs, gimple_assign_lhs (else_assign), 0)) | |
1567 | return false; | |
1568 | ||
1569 | lhs_base = get_base_address (lhs); | |
1570 | if (lhs_base == NULL_TREE | |
1571 | || (!DECL_P (lhs_base) && TREE_CODE (lhs_base) != MEM_REF)) | |
1572 | return false; | |
1573 | ||
1574 | then_rhs = gimple_assign_rhs1 (then_assign); | |
1575 | else_rhs = gimple_assign_rhs1 (else_assign); | |
1576 | then_locus = gimple_location (then_assign); | |
1577 | else_locus = gimple_location (else_assign); | |
1578 | ||
1579 | /* Now we've checked the constraints, so do the transformation: | |
1580 | 1) Remove the stores. */ | |
1581 | gsi = gsi_for_stmt (then_assign); | |
1582 | unlink_stmt_vdef (then_assign); | |
1583 | gsi_remove (&gsi, true); | |
1584 | release_defs (then_assign); | |
1585 | ||
1586 | gsi = gsi_for_stmt (else_assign); | |
1587 | unlink_stmt_vdef (else_assign); | |
1588 | gsi_remove (&gsi, true); | |
1589 | release_defs (else_assign); | |
1590 | ||
03d37e4e | 1591 | /* 2) Create a PHI node at the join block, with one argument |
91cf53d5 | 1592 | holding the old RHS, and the other holding the temporary |
1593 | where we stored the old memory contents. */ | |
03d37e4e | 1594 | name = make_temp_ssa_name (TREE_TYPE (lhs), NULL, "cstore"); |
1595 | newphi = create_phi_node (name, join_bb); | |
60d535d2 | 1596 | add_phi_arg (newphi, then_rhs, EDGE_SUCC (then_bb, 0), then_locus); |
1597 | add_phi_arg (newphi, else_rhs, EDGE_SUCC (else_bb, 0), else_locus); | |
91cf53d5 | 1598 | |
1599 | new_stmt = gimple_build_assign (lhs, PHI_RESULT (newphi)); | |
1600 | ||
03d37e4e | 1601 | /* 3) Insert that PHI node. */ |
91cf53d5 | 1602 | gsi = gsi_after_labels (join_bb); |
1603 | if (gsi_end_p (gsi)) | |
1604 | { | |
1605 | gsi = gsi_last_bb (join_bb); | |
1606 | gsi_insert_after (&gsi, new_stmt, GSI_NEW_STMT); | |
1607 | } | |
1608 | else | |
1609 | gsi_insert_before (&gsi, new_stmt, GSI_NEW_STMT); | |
1610 | ||
1611 | return true; | |
1612 | } | |
1613 | ||
ec611e12 | 1614 | /* Conditional store replacement. We already know |
1615 | that the recognized pattern looks like so: | |
1616 | ||
1617 | split: | |
1618 | if (cond) goto THEN_BB; else goto ELSE_BB (edge E1) | |
1619 | THEN_BB: | |
1620 | ... | |
1621 | X = Y; | |
1622 | ... | |
1623 | goto JOIN_BB; | |
1624 | ELSE_BB: | |
1625 | ... | |
1626 | X = Z; | |
1627 | ... | |
1628 | fallthrough (edge E0) | |
1629 | JOIN_BB: | |
1630 | some more | |
1631 | ||
1632 | We check that it is safe to sink the store to JOIN_BB by verifying that | |
1633 | there are no read-after-write or write-after-write dependencies in | |
1634 | THEN_BB and ELSE_BB. */ | |
1635 | ||
1636 | static bool | |
1637 | cond_if_else_store_replacement (basic_block then_bb, basic_block else_bb, | |
1638 | basic_block join_bb) | |
1639 | { | |
1640 | gimple then_assign = last_and_only_stmt (then_bb); | |
1641 | gimple else_assign = last_and_only_stmt (else_bb); | |
f1f41a6c | 1642 | vec<data_reference_p> then_datarefs, else_datarefs; |
1643 | vec<ddr_p> then_ddrs, else_ddrs; | |
ec611e12 | 1644 | gimple then_store, else_store; |
1645 | bool found, ok = false, res; | |
1646 | struct data_dependence_relation *ddr; | |
1647 | data_reference_p then_dr, else_dr; | |
1648 | int i, j; | |
1649 | tree then_lhs, else_lhs; | |
f1f41a6c | 1650 | vec<gimple> then_stores, else_stores; |
ec611e12 | 1651 | basic_block blocks[3]; |
1652 | ||
1653 | if (MAX_STORES_TO_SINK == 0) | |
1654 | return false; | |
1655 | ||
1656 | /* Handle the case with single statement in THEN_BB and ELSE_BB. */ | |
1657 | if (then_assign && else_assign) | |
1658 | return cond_if_else_store_replacement_1 (then_bb, else_bb, join_bb, | |
1659 | then_assign, else_assign); | |
1660 | ||
1661 | /* Find data references. */ | |
f1f41a6c | 1662 | then_datarefs.create (1); |
1663 | else_datarefs.create (1); | |
ec611e12 | 1664 | if ((find_data_references_in_bb (NULL, then_bb, &then_datarefs) |
1665 | == chrec_dont_know) | |
f1f41a6c | 1666 | || !then_datarefs.length () |
ec611e12 | 1667 | || (find_data_references_in_bb (NULL, else_bb, &else_datarefs) |
1668 | == chrec_dont_know) | |
f1f41a6c | 1669 | || !else_datarefs.length ()) |
ec611e12 | 1670 | { |
1671 | free_data_refs (then_datarefs); | |
1672 | free_data_refs (else_datarefs); | |
1673 | return false; | |
1674 | } | |
1675 | ||
1676 | /* Find pairs of stores with equal LHS. */ | |
f1f41a6c | 1677 | then_stores.create (1); |
1678 | else_stores.create (1); | |
1679 | FOR_EACH_VEC_ELT (then_datarefs, i, then_dr) | |
ec611e12 | 1680 | { |
1681 | if (DR_IS_READ (then_dr)) | |
1682 | continue; | |
1683 | ||
1684 | then_store = DR_STMT (then_dr); | |
728dcc71 | 1685 | then_lhs = gimple_get_lhs (then_store); |
ec611e12 | 1686 | found = false; |
1687 | ||
f1f41a6c | 1688 | FOR_EACH_VEC_ELT (else_datarefs, j, else_dr) |
ec611e12 | 1689 | { |
1690 | if (DR_IS_READ (else_dr)) | |
1691 | continue; | |
1692 | ||
1693 | else_store = DR_STMT (else_dr); | |
728dcc71 | 1694 | else_lhs = gimple_get_lhs (else_store); |
ec611e12 | 1695 | |
1696 | if (operand_equal_p (then_lhs, else_lhs, 0)) | |
1697 | { | |
1698 | found = true; | |
1699 | break; | |
1700 | } | |
1701 | } | |
1702 | ||
1703 | if (!found) | |
1704 | continue; | |
1705 | ||
f1f41a6c | 1706 | then_stores.safe_push (then_store); |
1707 | else_stores.safe_push (else_store); | |
ec611e12 | 1708 | } |
1709 | ||
1710 | /* No pairs of stores found. */ | |
f1f41a6c | 1711 | if (!then_stores.length () |
1712 | || then_stores.length () > (unsigned) MAX_STORES_TO_SINK) | |
ec611e12 | 1713 | { |
1714 | free_data_refs (then_datarefs); | |
1715 | free_data_refs (else_datarefs); | |
f1f41a6c | 1716 | then_stores.release (); |
1717 | else_stores.release (); | |
ec611e12 | 1718 | return false; |
1719 | } | |
1720 | ||
1721 | /* Compute and check data dependencies in both basic blocks. */ | |
f1f41a6c | 1722 | then_ddrs.create (1); |
1723 | else_ddrs.create (1); | |
1724 | if (!compute_all_dependences (then_datarefs, &then_ddrs, | |
1e094109 | 1725 | vNULL, false) |
f1f41a6c | 1726 | || !compute_all_dependences (else_datarefs, &else_ddrs, |
1e094109 | 1727 | vNULL, false)) |
8b3fb720 | 1728 | { |
1729 | free_dependence_relations (then_ddrs); | |
1730 | free_dependence_relations (else_ddrs); | |
1731 | free_data_refs (then_datarefs); | |
1732 | free_data_refs (else_datarefs); | |
f1f41a6c | 1733 | then_stores.release (); |
1734 | else_stores.release (); | |
8b3fb720 | 1735 | return false; |
1736 | } | |
ec611e12 | 1737 | blocks[0] = then_bb; |
1738 | blocks[1] = else_bb; | |
1739 | blocks[2] = join_bb; | |
1740 | renumber_gimple_stmt_uids_in_blocks (blocks, 3); | |
1741 | ||
1742 | /* Check that there are no read-after-write or write-after-write dependencies | |
1743 | in THEN_BB. */ | |
f1f41a6c | 1744 | FOR_EACH_VEC_ELT (then_ddrs, i, ddr) |
ec611e12 | 1745 | { |
1746 | struct data_reference *dra = DDR_A (ddr); | |
1747 | struct data_reference *drb = DDR_B (ddr); | |
1748 | ||
1749 | if (DDR_ARE_DEPENDENT (ddr) != chrec_known | |
1750 | && ((DR_IS_READ (dra) && DR_IS_WRITE (drb) | |
1751 | && gimple_uid (DR_STMT (dra)) > gimple_uid (DR_STMT (drb))) | |
1752 | || (DR_IS_READ (drb) && DR_IS_WRITE (dra) | |
1753 | && gimple_uid (DR_STMT (drb)) > gimple_uid (DR_STMT (dra))) | |
1754 | || (DR_IS_WRITE (dra) && DR_IS_WRITE (drb)))) | |
1755 | { | |
1756 | free_dependence_relations (then_ddrs); | |
1757 | free_dependence_relations (else_ddrs); | |
2473bfb7 | 1758 | free_data_refs (then_datarefs); |
1759 | free_data_refs (else_datarefs); | |
f1f41a6c | 1760 | then_stores.release (); |
1761 | else_stores.release (); | |
ec611e12 | 1762 | return false; |
1763 | } | |
1764 | } | |
1765 | ||
1766 | /* Check that there are no read-after-write or write-after-write dependencies | |
1767 | in ELSE_BB. */ | |
f1f41a6c | 1768 | FOR_EACH_VEC_ELT (else_ddrs, i, ddr) |
ec611e12 | 1769 | { |
1770 | struct data_reference *dra = DDR_A (ddr); | |
1771 | struct data_reference *drb = DDR_B (ddr); | |
1772 | ||
1773 | if (DDR_ARE_DEPENDENT (ddr) != chrec_known | |
1774 | && ((DR_IS_READ (dra) && DR_IS_WRITE (drb) | |
1775 | && gimple_uid (DR_STMT (dra)) > gimple_uid (DR_STMT (drb))) | |
1776 | || (DR_IS_READ (drb) && DR_IS_WRITE (dra) | |
1777 | && gimple_uid (DR_STMT (drb)) > gimple_uid (DR_STMT (dra))) | |
1778 | || (DR_IS_WRITE (dra) && DR_IS_WRITE (drb)))) | |
1779 | { | |
1780 | free_dependence_relations (then_ddrs); | |
1781 | free_dependence_relations (else_ddrs); | |
2473bfb7 | 1782 | free_data_refs (then_datarefs); |
1783 | free_data_refs (else_datarefs); | |
f1f41a6c | 1784 | then_stores.release (); |
1785 | else_stores.release (); | |
ec611e12 | 1786 | return false; |
1787 | } | |
1788 | } | |
1789 | ||
1790 | /* Sink stores with same LHS. */ | |
f1f41a6c | 1791 | FOR_EACH_VEC_ELT (then_stores, i, then_store) |
ec611e12 | 1792 | { |
f1f41a6c | 1793 | else_store = else_stores[i]; |
ec611e12 | 1794 | res = cond_if_else_store_replacement_1 (then_bb, else_bb, join_bb, |
1795 | then_store, else_store); | |
1796 | ok = ok || res; | |
1797 | } | |
1798 | ||
1799 | free_dependence_relations (then_ddrs); | |
1800 | free_dependence_relations (else_ddrs); | |
2473bfb7 | 1801 | free_data_refs (then_datarefs); |
1802 | free_data_refs (else_datarefs); | |
f1f41a6c | 1803 | then_stores.release (); |
1804 | else_stores.release (); | |
ec611e12 | 1805 | |
1806 | return ok; | |
1807 | } | |
1808 | ||
239e9670 | 1809 | /* Return TRUE if STMT has a VUSE whose corresponding VDEF is in BB. */ |
1810 | ||
1811 | static bool | |
1812 | local_mem_dependence (gimple stmt, basic_block bb) | |
1813 | { | |
1814 | tree vuse = gimple_vuse (stmt); | |
1815 | gimple def; | |
1816 | ||
1817 | if (!vuse) | |
1818 | return false; | |
1819 | ||
1820 | def = SSA_NAME_DEF_STMT (vuse); | |
1821 | return (def && gimple_bb (def) == bb); | |
1822 | } | |
1823 | ||
1824 | /* Given a "diamond" control-flow pattern where BB0 tests a condition, | |
1825 | BB1 and BB2 are "then" and "else" blocks dependent on this test, | |
1826 | and BB3 rejoins control flow following BB1 and BB2, look for | |
1827 | opportunities to hoist loads as follows. If BB3 contains a PHI of | |
1828 | two loads, one each occurring in BB1 and BB2, and the loads are | |
1829 | provably of adjacent fields in the same structure, then move both | |
1830 | loads into BB0. Of course this can only be done if there are no | |
1831 | dependencies preventing such motion. | |
1832 | ||
1833 | One of the hoisted loads will always be speculative, so the | |
1834 | transformation is currently conservative: | |
1835 | ||
1836 | - The fields must be strictly adjacent. | |
1837 | - The two fields must occupy a single memory block that is | |
1838 | guaranteed to not cross a page boundary. | |
1839 | ||
1840 | The last is difficult to prove, as such memory blocks should be | |
1841 | aligned on the minimum of the stack alignment boundary and the | |
1842 | alignment guaranteed by heap allocation interfaces. Thus we rely | |
1843 | on a parameter for the alignment value. | |
1844 | ||
1845 | Provided a good value is used for the last case, the first | |
1846 | restriction could possibly be relaxed. */ | |
1847 | ||
1848 | static void | |
1849 | hoist_adjacent_loads (basic_block bb0, basic_block bb1, | |
1850 | basic_block bb2, basic_block bb3) | |
1851 | { | |
1852 | int param_align = PARAM_VALUE (PARAM_L1_CACHE_LINE_SIZE); | |
1853 | unsigned param_align_bits = (unsigned) (param_align * BITS_PER_UNIT); | |
1854 | gimple_stmt_iterator gsi; | |
1855 | ||
1856 | /* Walk the phis in bb3 looking for an opportunity. We are looking | |
1857 | for phis of two SSA names, one each of which is defined in bb1 and | |
1858 | bb2. */ | |
1859 | for (gsi = gsi_start_phis (bb3); !gsi_end_p (gsi); gsi_next (&gsi)) | |
1860 | { | |
1861 | gimple phi_stmt = gsi_stmt (gsi); | |
1862 | gimple def1, def2, defswap; | |
1863 | tree arg1, arg2, ref1, ref2, field1, field2, fieldswap; | |
1864 | tree tree_offset1, tree_offset2, tree_size2, next; | |
1865 | int offset1, offset2, size2; | |
1866 | unsigned align1; | |
1867 | gimple_stmt_iterator gsi2; | |
1868 | basic_block bb_for_def1, bb_for_def2; | |
1869 | ||
7c782c9b | 1870 | if (gimple_phi_num_args (phi_stmt) != 2 |
1871 | || virtual_operand_p (gimple_phi_result (phi_stmt))) | |
239e9670 | 1872 | continue; |
1873 | ||
1874 | arg1 = gimple_phi_arg_def (phi_stmt, 0); | |
1875 | arg2 = gimple_phi_arg_def (phi_stmt, 1); | |
1876 | ||
1877 | if (TREE_CODE (arg1) != SSA_NAME | |
1878 | || TREE_CODE (arg2) != SSA_NAME | |
1879 | || SSA_NAME_IS_DEFAULT_DEF (arg1) | |
7c782c9b | 1880 | || SSA_NAME_IS_DEFAULT_DEF (arg2)) |
239e9670 | 1881 | continue; |
1882 | ||
1883 | def1 = SSA_NAME_DEF_STMT (arg1); | |
1884 | def2 = SSA_NAME_DEF_STMT (arg2); | |
1885 | ||
1886 | if ((gimple_bb (def1) != bb1 || gimple_bb (def2) != bb2) | |
1887 | && (gimple_bb (def2) != bb1 || gimple_bb (def1) != bb2)) | |
1888 | continue; | |
1889 | ||
1890 | /* Check the mode of the arguments to be sure a conditional move | |
1891 | can be generated for it. */ | |
935611bc | 1892 | if (optab_handler (movcc_optab, TYPE_MODE (TREE_TYPE (arg1))) |
1893 | == CODE_FOR_nothing) | |
239e9670 | 1894 | continue; |
1895 | ||
1896 | /* Both statements must be assignments whose RHS is a COMPONENT_REF. */ | |
1897 | if (!gimple_assign_single_p (def1) | |
6cc085b6 | 1898 | || !gimple_assign_single_p (def2) |
1899 | || gimple_has_volatile_ops (def1) | |
1900 | || gimple_has_volatile_ops (def2)) | |
239e9670 | 1901 | continue; |
1902 | ||
1903 | ref1 = gimple_assign_rhs1 (def1); | |
1904 | ref2 = gimple_assign_rhs1 (def2); | |
1905 | ||
1906 | if (TREE_CODE (ref1) != COMPONENT_REF | |
1907 | || TREE_CODE (ref2) != COMPONENT_REF) | |
1908 | continue; | |
1909 | ||
1910 | /* The zeroth operand of the two component references must be | |
1911 | identical. It is not sufficient to compare get_base_address of | |
1912 | the two references, because this could allow for different | |
1913 | elements of the same array in the two trees. It is not safe to | |
1914 | assume that the existence of one array element implies the | |
1915 | existence of a different one. */ | |
1916 | if (!operand_equal_p (TREE_OPERAND (ref1, 0), TREE_OPERAND (ref2, 0), 0)) | |
1917 | continue; | |
1918 | ||
1919 | field1 = TREE_OPERAND (ref1, 1); | |
1920 | field2 = TREE_OPERAND (ref2, 1); | |
1921 | ||
1922 | /* Check for field adjacency, and ensure field1 comes first. */ | |
1923 | for (next = DECL_CHAIN (field1); | |
1924 | next && TREE_CODE (next) != FIELD_DECL; | |
1925 | next = DECL_CHAIN (next)) | |
1926 | ; | |
1927 | ||
1928 | if (next != field2) | |
1929 | { | |
1930 | for (next = DECL_CHAIN (field2); | |
1931 | next && TREE_CODE (next) != FIELD_DECL; | |
1932 | next = DECL_CHAIN (next)) | |
1933 | ; | |
1934 | ||
1935 | if (next != field1) | |
1936 | continue; | |
1937 | ||
1938 | fieldswap = field1; | |
1939 | field1 = field2; | |
1940 | field2 = fieldswap; | |
1941 | defswap = def1; | |
1942 | def1 = def2; | |
1943 | def2 = defswap; | |
239e9670 | 1944 | } |
1945 | ||
7c74ee50 | 1946 | bb_for_def1 = gimple_bb (def1); |
1947 | bb_for_def2 = gimple_bb (def2); | |
1948 | ||
239e9670 | 1949 | /* Check for proper alignment of the first field. */ |
1950 | tree_offset1 = bit_position (field1); | |
1951 | tree_offset2 = bit_position (field2); | |
1952 | tree_size2 = DECL_SIZE (field2); | |
1953 | ||
1954 | if (!host_integerp (tree_offset1, 1) | |
1955 | || !host_integerp (tree_offset2, 1) | |
1956 | || !host_integerp (tree_size2, 1)) | |
1957 | continue; | |
1958 | ||
1959 | offset1 = TREE_INT_CST_LOW (tree_offset1); | |
1960 | offset2 = TREE_INT_CST_LOW (tree_offset2); | |
1961 | size2 = TREE_INT_CST_LOW (tree_size2); | |
1962 | align1 = DECL_ALIGN (field1) % param_align_bits; | |
1963 | ||
1964 | if (offset1 % BITS_PER_UNIT != 0) | |
1965 | continue; | |
1966 | ||
1967 | /* For profitability, the two field references should fit within | |
1968 | a single cache line. */ | |
1969 | if (align1 + offset2 - offset1 + size2 > param_align_bits) | |
1970 | continue; | |
1971 | ||
1972 | /* The two expressions cannot be dependent upon vdefs defined | |
1973 | in bb1/bb2. */ | |
1974 | if (local_mem_dependence (def1, bb_for_def1) | |
1975 | || local_mem_dependence (def2, bb_for_def2)) | |
1976 | continue; | |
1977 | ||
1978 | /* The conditions are satisfied; hoist the loads from bb1 and bb2 into | |
1979 | bb0. We hoist the first one first so that a cache miss is handled | |
1980 | efficiently regardless of hardware cache-fill policy. */ | |
1981 | gsi2 = gsi_for_stmt (def1); | |
1982 | gsi_move_to_bb_end (&gsi2, bb0); | |
1983 | gsi2 = gsi_for_stmt (def2); | |
1984 | gsi_move_to_bb_end (&gsi2, bb0); | |
1985 | ||
1986 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1987 | { | |
1988 | fprintf (dump_file, | |
1989 | "\nHoisting adjacent loads from %d and %d into %d: \n", | |
1990 | bb_for_def1->index, bb_for_def2->index, bb0->index); | |
1991 | print_gimple_stmt (dump_file, def1, 0, TDF_VOPS|TDF_MEMSYMS); | |
1992 | print_gimple_stmt (dump_file, def2, 0, TDF_VOPS|TDF_MEMSYMS); | |
1993 | } | |
1994 | } | |
1995 | } | |
1996 | ||
1997 | /* Determine whether we should attempt to hoist adjacent loads out of | |
1998 | diamond patterns in pass_phiopt. Always hoist loads if | |
1999 | -fhoist-adjacent-loads is specified and the target machine has | |
6f0ddab1 | 2000 | both a conditional move instruction and a defined cache line size. */ |
239e9670 | 2001 | |
2002 | static bool | |
2003 | gate_hoist_loads (void) | |
2004 | { | |
6f0ddab1 | 2005 | return (flag_hoist_adjacent_loads == 1 |
2006 | && PARAM_VALUE (PARAM_L1_CACHE_LINE_SIZE) | |
2007 | && HAVE_conditional_move); | |
239e9670 | 2008 | } |
2009 | ||
4ee9c684 | 2010 | /* Always do these optimizations if we have SSA |
20e5647c | 2011 | trees to work on. */ |
4ee9c684 | 2012 | static bool |
2013 | gate_phiopt (void) | |
2014 | { | |
2015 | return 1; | |
2016 | } | |
20e5647c | 2017 | |
20099e35 | 2018 | struct gimple_opt_pass pass_phiopt = |
4ee9c684 | 2019 | { |
20099e35 | 2020 | { |
2021 | GIMPLE_PASS, | |
4ee9c684 | 2022 | "phiopt", /* name */ |
c7875731 | 2023 | OPTGROUP_NONE, /* optinfo_flags */ |
4ee9c684 | 2024 | gate_phiopt, /* gate */ |
2025 | tree_ssa_phiopt, /* execute */ | |
2026 | NULL, /* sub */ | |
2027 | NULL, /* next */ | |
2028 | 0, /* static_pass_number */ | |
2029 | TV_TREE_PHIOPT, /* tv_id */ | |
2f8eb909 | 2030 | PROP_cfg | PROP_ssa, /* properties_required */ |
4ee9c684 | 2031 | 0, /* properties_provided */ |
2032 | 0, /* properties_destroyed */ | |
2033 | 0, /* todo_flags_start */ | |
ef3baff5 | 2034 | TODO_verify_ssa |
88dbf20f | 2035 | | TODO_verify_flow |
20099e35 | 2036 | | TODO_verify_stmts /* todo_flags_finish */ |
2037 | } | |
4ee9c684 | 2038 | }; |
e6d0e152 | 2039 | |
2040 | static bool | |
2041 | gate_cselim (void) | |
2042 | { | |
2043 | return flag_tree_cselim; | |
2044 | } | |
2045 | ||
20099e35 | 2046 | struct gimple_opt_pass pass_cselim = |
e6d0e152 | 2047 | { |
20099e35 | 2048 | { |
2049 | GIMPLE_PASS, | |
e6d0e152 | 2050 | "cselim", /* name */ |
c7875731 | 2051 | OPTGROUP_NONE, /* optinfo_flags */ |
e6d0e152 | 2052 | gate_cselim, /* gate */ |
2053 | tree_ssa_cs_elim, /* execute */ | |
2054 | NULL, /* sub */ | |
2055 | NULL, /* next */ | |
2056 | 0, /* static_pass_number */ | |
2057 | TV_TREE_PHIOPT, /* tv_id */ | |
2f8eb909 | 2058 | PROP_cfg | PROP_ssa, /* properties_required */ |
e6d0e152 | 2059 | 0, /* properties_provided */ |
2060 | 0, /* properties_destroyed */ | |
2061 | 0, /* todo_flags_start */ | |
ef3baff5 | 2062 | TODO_verify_ssa |
e6d0e152 | 2063 | | TODO_verify_flow |
20099e35 | 2064 | | TODO_verify_stmts /* todo_flags_finish */ |
2065 | } | |
e6d0e152 | 2066 | }; |