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4ee9c684 | 1 | /* Optimization of PHI nodes by converting them into straightline code. |
fbd26352 | 2 | Copyright (C) 2004-2019 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" |
7c29e30e | 24 | #include "insn-codes.h" |
25 | #include "rtl.h" | |
4ee9c684 | 26 | #include "tree.h" |
9ef16211 | 27 | #include "gimple.h" |
7c29e30e | 28 | #include "cfghooks.h" |
29 | #include "tree-pass.h" | |
9ef16211 | 30 | #include "ssa.h" |
7c29e30e | 31 | #include "optabs-tree.h" |
32 | #include "insn-config.h" | |
33 | #include "gimple-pretty-print.h" | |
b20a8bb4 | 34 | #include "fold-const.h" |
9ed99284 | 35 | #include "stor-layout.h" |
94ea8568 | 36 | #include "cfganal.h" |
a8783bee | 37 | #include "gimplify.h" |
dcf1a1ec | 38 | #include "gimple-iterator.h" |
e795d6e1 | 39 | #include "gimplify-me.h" |
073c1fd5 | 40 | #include "tree-cfg.h" |
073c1fd5 | 41 | #include "tree-dfa.h" |
e6d0e152 | 42 | #include "domwalk.h" |
ec611e12 | 43 | #include "cfgloop.h" |
44 | #include "tree-data-ref.h" | |
f6568ea4 | 45 | #include "tree-scalar-evolution.h" |
b6814ca0 | 46 | #include "tree-inline.h" |
0d8001a7 | 47 | #include "params.h" |
a75cc7d9 | 48 | #include "case-cfn-macros.h" |
239e9670 | 49 | |
a2c2432d | 50 | static unsigned int tree_ssa_phiopt_worker (bool, bool, bool); |
162634aa | 51 | static bool two_value_replacement (basic_block, basic_block, edge, gphi *, |
52 | tree, tree); | |
a4844041 | 53 | static bool conditional_replacement (basic_block, basic_block, |
1a91d914 | 54 | edge, edge, gphi *, tree, tree); |
8100256d | 55 | static gphi *factor_out_conditional_conversion (edge, edge, gphi *, tree, tree, |
56 | gimple *); | |
fb9912ea | 57 | static int value_replacement (basic_block, basic_block, |
42acab1c | 58 | edge, edge, gimple *, tree, tree); |
a4844041 | 59 | static bool minmax_replacement (basic_block, basic_block, |
42acab1c | 60 | edge, edge, gimple *, tree, tree); |
a4844041 | 61 | static bool abs_replacement (basic_block, basic_block, |
42acab1c | 62 | edge, edge, gimple *, tree, tree); |
a75cc7d9 | 63 | static bool cond_removal_in_popcount_pattern (basic_block, basic_block, |
64 | edge, edge, gimple *, tree, tree); | |
e6d0e152 | 65 | static bool cond_store_replacement (basic_block, basic_block, edge, edge, |
431205b7 | 66 | hash_set<tree> *); |
91cf53d5 | 67 | static bool cond_if_else_store_replacement (basic_block, basic_block, basic_block); |
431205b7 | 68 | static hash_set<tree> * get_non_trapping (); |
42acab1c | 69 | static void replace_phi_edge_with_variable (basic_block, edge, gimple *, tree); |
239e9670 | 70 | static void hoist_adjacent_loads (basic_block, basic_block, |
71 | basic_block, basic_block); | |
72 | static bool gate_hoist_loads (void); | |
902929aa | 73 | |
e6d0e152 | 74 | /* This pass tries to transform conditional stores into unconditional |
75 | ones, enabling further simplifications with the simpler then and else | |
76 | blocks. In particular it replaces this: | |
77 | ||
78 | bb0: | |
79 | if (cond) goto bb2; else goto bb1; | |
80 | bb1: | |
91cf53d5 | 81 | *p = RHS; |
e6d0e152 | 82 | bb2: |
83 | ||
84 | with | |
85 | ||
86 | bb0: | |
87 | if (cond) goto bb1; else goto bb2; | |
88 | bb1: | |
89 | condtmp' = *p; | |
90 | bb2: | |
91 | condtmp = PHI <RHS, condtmp'> | |
91cf53d5 | 92 | *p = condtmp; |
e6d0e152 | 93 | |
94 | This transformation can only be done under several constraints, | |
91cf53d5 | 95 | documented below. It also replaces: |
96 | ||
97 | bb0: | |
98 | if (cond) goto bb2; else goto bb1; | |
99 | bb1: | |
100 | *p = RHS1; | |
101 | goto bb3; | |
102 | bb2: | |
103 | *p = RHS2; | |
104 | bb3: | |
105 | ||
106 | with | |
107 | ||
108 | bb0: | |
109 | if (cond) goto bb3; else goto bb1; | |
110 | bb1: | |
111 | bb3: | |
112 | condtmp = PHI <RHS1, RHS2> | |
113 | *p = condtmp; */ | |
e6d0e152 | 114 | |
115 | static unsigned int | |
116 | tree_ssa_cs_elim (void) | |
117 | { | |
f6568ea4 | 118 | unsigned todo; |
119 | /* ??? We are not interested in loop related info, but the following | |
120 | will create it, ICEing as we didn't init loops with pre-headers. | |
121 | An interfacing issue of find_data_references_in_bb. */ | |
122 | loop_optimizer_init (LOOPS_NORMAL); | |
123 | scev_initialize (); | |
a2c2432d | 124 | todo = tree_ssa_phiopt_worker (true, false, false); |
f6568ea4 | 125 | scev_finalize (); |
126 | loop_optimizer_finalize (); | |
127 | return todo; | |
e6d0e152 | 128 | } |
129 | ||
c3597b05 | 130 | /* Return the singleton PHI in the SEQ of PHIs for edges E0 and E1. */ |
131 | ||
1a91d914 | 132 | static gphi * |
c3597b05 | 133 | single_non_singleton_phi_for_edges (gimple_seq seq, edge e0, edge e1) |
134 | { | |
135 | gimple_stmt_iterator i; | |
1a91d914 | 136 | gphi *phi = NULL; |
c3597b05 | 137 | if (gimple_seq_singleton_p (seq)) |
1a91d914 | 138 | return as_a <gphi *> (gsi_stmt (gsi_start (seq))); |
c3597b05 | 139 | for (i = gsi_start (seq); !gsi_end_p (i); gsi_next (&i)) |
140 | { | |
1a91d914 | 141 | gphi *p = as_a <gphi *> (gsi_stmt (i)); |
c3597b05 | 142 | /* If the PHI arguments are equal then we can skip this PHI. */ |
143 | if (operand_equal_for_phi_arg_p (gimple_phi_arg_def (p, e0->dest_idx), | |
144 | gimple_phi_arg_def (p, e1->dest_idx))) | |
145 | continue; | |
146 | ||
147 | /* If we already have a PHI that has the two edge arguments are | |
148 | different, then return it is not a singleton for these PHIs. */ | |
149 | if (phi) | |
150 | return NULL; | |
151 | ||
152 | phi = p; | |
153 | } | |
154 | return phi; | |
155 | } | |
156 | ||
e6d0e152 | 157 | /* The core routine of conditional store replacement and normal |
158 | phi optimizations. Both share much of the infrastructure in how | |
159 | to match applicable basic block patterns. DO_STORE_ELIM is true | |
239e9670 | 160 | when we want to do conditional store replacement, false otherwise. |
f32420fb | 161 | DO_HOIST_LOADS is true when we want to hoist adjacent loads out |
239e9670 | 162 | of diamond control flow patterns, false otherwise. */ |
e6d0e152 | 163 | static unsigned int |
a2c2432d | 164 | tree_ssa_phiopt_worker (bool do_store_elim, bool do_hoist_loads, bool early_p) |
4ee9c684 | 165 | { |
166 | basic_block bb; | |
194899bf | 167 | basic_block *bb_order; |
168 | unsigned n, i; | |
1e4b21e3 | 169 | bool cfgchanged = false; |
431205b7 | 170 | hash_set<tree> *nontrap = 0; |
e6d0e152 | 171 | |
172 | if (do_store_elim) | |
03d37e4e | 173 | /* Calculate the set of non-trapping memory accesses. */ |
174 | nontrap = get_non_trapping (); | |
194899bf | 175 | |
176 | /* Search every basic block for COND_EXPR we may be able to optimize. | |
177 | ||
178 | We walk the blocks in order that guarantees that a block with | |
179 | a single predecessor is processed before the predecessor. | |
180 | This ensures that we collapse inner ifs before visiting the | |
181 | outer ones, and also that we do not try to visit a removed | |
182 | block. */ | |
ba4d2b2f | 183 | bb_order = single_pred_before_succ_order (); |
a28770e1 | 184 | n = n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS; |
4ee9c684 | 185 | |
48e1416a | 186 | for (i = 0; i < n; i++) |
4ee9c684 | 187 | { |
42acab1c | 188 | gimple *cond_stmt; |
1a91d914 | 189 | gphi *phi; |
33784d89 | 190 | basic_block bb1, bb2; |
191 | edge e1, e2; | |
194899bf | 192 | tree arg0, arg1; |
193 | ||
194 | bb = bb_order[i]; | |
20e5647c | 195 | |
75a70cf9 | 196 | cond_stmt = last_stmt (bb); |
197 | /* Check to see if the last statement is a GIMPLE_COND. */ | |
198 | if (!cond_stmt | |
199 | || gimple_code (cond_stmt) != GIMPLE_COND) | |
33784d89 | 200 | continue; |
20e5647c | 201 | |
33784d89 | 202 | e1 = EDGE_SUCC (bb, 0); |
203 | bb1 = e1->dest; | |
204 | e2 = EDGE_SUCC (bb, 1); | |
205 | bb2 = e2->dest; | |
20e5647c | 206 | |
33784d89 | 207 | /* We cannot do the optimization on abnormal edges. */ |
208 | if ((e1->flags & EDGE_ABNORMAL) != 0 | |
209 | || (e2->flags & EDGE_ABNORMAL) != 0) | |
210 | continue; | |
20e5647c | 211 | |
33784d89 | 212 | /* If either bb1's succ or bb2 or bb2's succ is non NULL. */ |
ea091dfd | 213 | if (EDGE_COUNT (bb1->succs) == 0 |
33784d89 | 214 | || bb2 == NULL |
ea091dfd | 215 | || EDGE_COUNT (bb2->succs) == 0) |
33784d89 | 216 | continue; |
20e5647c | 217 | |
33784d89 | 218 | /* Find the bb which is the fall through to the other. */ |
219 | if (EDGE_SUCC (bb1, 0)->dest == bb2) | |
220 | ; | |
221 | else if (EDGE_SUCC (bb2, 0)->dest == bb1) | |
222 | { | |
a4f59596 | 223 | std::swap (bb1, bb2); |
224 | std::swap (e1, e2); | |
33784d89 | 225 | } |
91cf53d5 | 226 | else if (do_store_elim |
227 | && EDGE_SUCC (bb1, 0)->dest == EDGE_SUCC (bb2, 0)->dest) | |
228 | { | |
229 | basic_block bb3 = EDGE_SUCC (bb1, 0)->dest; | |
230 | ||
231 | if (!single_succ_p (bb1) | |
232 | || (EDGE_SUCC (bb1, 0)->flags & EDGE_FALLTHRU) == 0 | |
233 | || !single_succ_p (bb2) | |
234 | || (EDGE_SUCC (bb2, 0)->flags & EDGE_FALLTHRU) == 0 | |
235 | || EDGE_COUNT (bb3->preds) != 2) | |
236 | continue; | |
237 | if (cond_if_else_store_replacement (bb1, bb2, bb3)) | |
238 | cfgchanged = true; | |
239 | continue; | |
240 | } | |
239e9670 | 241 | else if (do_hoist_loads |
8100256d | 242 | && EDGE_SUCC (bb1, 0)->dest == EDGE_SUCC (bb2, 0)->dest) |
239e9670 | 243 | { |
244 | basic_block bb3 = EDGE_SUCC (bb1, 0)->dest; | |
245 | ||
246 | if (!FLOAT_TYPE_P (TREE_TYPE (gimple_cond_lhs (cond_stmt))) | |
247 | && single_succ_p (bb1) | |
248 | && single_succ_p (bb2) | |
249 | && single_pred_p (bb1) | |
250 | && single_pred_p (bb2) | |
251 | && EDGE_COUNT (bb->succs) == 2 | |
252 | && EDGE_COUNT (bb3->preds) == 2 | |
253 | /* If one edge or the other is dominant, a conditional move | |
254 | is likely to perform worse than the well-predicted branch. */ | |
255 | && !predictable_edge_p (EDGE_SUCC (bb, 0)) | |
256 | && !predictable_edge_p (EDGE_SUCC (bb, 1))) | |
257 | hoist_adjacent_loads (bb, bb1, bb2, bb3); | |
258 | continue; | |
259 | } | |
33784d89 | 260 | else |
f32420fb | 261 | continue; |
20e5647c | 262 | |
33784d89 | 263 | e1 = EDGE_SUCC (bb1, 0); |
20e5647c | 264 | |
33784d89 | 265 | /* Make sure that bb1 is just a fall through. */ |
db5ba14c | 266 | if (!single_succ_p (bb1) |
33784d89 | 267 | || (e1->flags & EDGE_FALLTHRU) == 0) |
268 | continue; | |
20e5647c | 269 | |
3472707f | 270 | /* Also make sure that bb1 only have one predecessor and that it |
271 | is bb. */ | |
ea091dfd | 272 | if (!single_pred_p (bb1) |
273 | || single_pred (bb1) != bb) | |
33784d89 | 274 | continue; |
20e5647c | 275 | |
e6d0e152 | 276 | if (do_store_elim) |
277 | { | |
278 | /* bb1 is the middle block, bb2 the join block, bb the split block, | |
279 | e1 the fallthrough edge from bb1 to bb2. We can't do the | |
280 | optimization if the join block has more than two predecessors. */ | |
281 | if (EDGE_COUNT (bb2->preds) > 2) | |
282 | continue; | |
283 | if (cond_store_replacement (bb1, bb2, e1, e2, nontrap)) | |
284 | cfgchanged = true; | |
285 | } | |
286 | else | |
287 | { | |
75a70cf9 | 288 | gimple_seq phis = phi_nodes (bb2); |
2109076a | 289 | gimple_stmt_iterator gsi; |
fb9912ea | 290 | bool candorest = true; |
c3597b05 | 291 | |
fb9912ea | 292 | /* Value replacement can work with more than one PHI |
293 | so try that first. */ | |
a2c2432d | 294 | if (!early_p) |
295 | for (gsi = gsi_start (phis); !gsi_end_p (gsi); gsi_next (&gsi)) | |
296 | { | |
297 | phi = as_a <gphi *> (gsi_stmt (gsi)); | |
298 | arg0 = gimple_phi_arg_def (phi, e1->dest_idx); | |
299 | arg1 = gimple_phi_arg_def (phi, e2->dest_idx); | |
300 | if (value_replacement (bb, bb1, e1, e2, phi, arg0, arg1) == 2) | |
301 | { | |
302 | candorest = false; | |
303 | cfgchanged = true; | |
304 | break; | |
305 | } | |
306 | } | |
e6d0e152 | 307 | |
fb9912ea | 308 | if (!candorest) |
309 | continue; | |
f32420fb | 310 | |
c3597b05 | 311 | phi = single_non_singleton_phi_for_edges (phis, e1, e2); |
2109076a | 312 | if (!phi) |
e6d0e152 | 313 | continue; |
314 | ||
75a70cf9 | 315 | arg0 = gimple_phi_arg_def (phi, e1->dest_idx); |
316 | arg1 = gimple_phi_arg_def (phi, e2->dest_idx); | |
e6d0e152 | 317 | |
318 | /* Something is wrong if we cannot find the arguments in the PHI | |
319 | node. */ | |
5dccd071 | 320 | gcc_assert (arg0 != NULL_TREE && arg1 != NULL_TREE); |
e6d0e152 | 321 | |
5dccd071 | 322 | gphi *newphi = factor_out_conditional_conversion (e1, e2, phi, |
8100256d | 323 | arg0, arg1, |
324 | cond_stmt); | |
5dccd071 | 325 | if (newphi != NULL) |
29a78fec | 326 | { |
5dccd071 | 327 | phi = newphi; |
29a78fec | 328 | /* factor_out_conditional_conversion may create a new PHI in |
329 | BB2 and eliminate an existing PHI in BB2. Recompute values | |
330 | that may be affected by that change. */ | |
29a78fec | 331 | arg0 = gimple_phi_arg_def (phi, e1->dest_idx); |
332 | arg1 = gimple_phi_arg_def (phi, e2->dest_idx); | |
5dccd071 | 333 | gcc_assert (arg0 != NULL_TREE && arg1 != NULL_TREE); |
29a78fec | 334 | } |
335 | ||
e6d0e152 | 336 | /* Do the replacement of conditional if it can be done. */ |
162634aa | 337 | if (two_value_replacement (bb, bb1, e2, phi, arg0, arg1)) |
338 | cfgchanged = true; | |
339 | else if (!early_p | |
340 | && conditional_replacement (bb, bb1, e1, e2, phi, | |
341 | arg0, arg1)) | |
e6d0e152 | 342 | cfgchanged = true; |
e6d0e152 | 343 | else if (abs_replacement (bb, bb1, e1, e2, phi, arg0, arg1)) |
344 | cfgchanged = true; | |
a2c2432d | 345 | else if (!early_p |
346 | && cond_removal_in_popcount_pattern (bb, bb1, e1, e2, | |
347 | phi, arg0, arg1)) | |
a75cc7d9 | 348 | cfgchanged = true; |
e6d0e152 | 349 | else if (minmax_replacement (bb, bb1, e1, e2, phi, arg0, arg1)) |
350 | cfgchanged = true; | |
351 | } | |
194899bf | 352 | } |
353 | ||
354 | free (bb_order); | |
48e1416a | 355 | |
e6d0e152 | 356 | if (do_store_elim) |
431205b7 | 357 | delete nontrap; |
e6d0e152 | 358 | /* If the CFG has changed, we should cleanup the CFG. */ |
359 | if (cfgchanged && do_store_elim) | |
360 | { | |
361 | /* In cond-store replacement we have added some loads on edges | |
362 | and new VOPS (as we moved the store, and created a load). */ | |
75a70cf9 | 363 | gsi_commit_edge_inserts (); |
e6d0e152 | 364 | return TODO_cleanup_cfg | TODO_update_ssa_only_virtuals; |
365 | } | |
366 | else if (cfgchanged) | |
367 | return TODO_cleanup_cfg; | |
368 | return 0; | |
194899bf | 369 | } |
370 | ||
fccee353 | 371 | /* Replace PHI node element whose edge is E in block BB with variable NEW. |
33784d89 | 372 | Remove the edge from COND_BLOCK which does not lead to BB (COND_BLOCK |
902929aa | 373 | is known to have two edges, one of which must reach BB). */ |
374 | ||
375 | static void | |
a4844041 | 376 | replace_phi_edge_with_variable (basic_block cond_block, |
42acab1c | 377 | edge e, gimple *phi, tree new_tree) |
902929aa | 378 | { |
75a70cf9 | 379 | basic_block bb = gimple_bb (phi); |
0e1a77e1 | 380 | basic_block block_to_remove; |
75a70cf9 | 381 | gimple_stmt_iterator gsi; |
33784d89 | 382 | |
20e5647c | 383 | /* Change the PHI argument to new. */ |
f0d6e81c | 384 | SET_USE (PHI_ARG_DEF_PTR (phi, e->dest_idx), new_tree); |
0e1a77e1 | 385 | |
0e1a77e1 | 386 | /* Remove the empty basic block. */ |
cd665a06 | 387 | if (EDGE_SUCC (cond_block, 0)->dest == bb) |
902929aa | 388 | { |
cd665a06 | 389 | EDGE_SUCC (cond_block, 0)->flags |= EDGE_FALLTHRU; |
390 | EDGE_SUCC (cond_block, 0)->flags &= ~(EDGE_TRUE_VALUE | EDGE_FALSE_VALUE); | |
720cfc43 | 391 | EDGE_SUCC (cond_block, 0)->probability = profile_probability::always (); |
0e1a77e1 | 392 | |
cd665a06 | 393 | block_to_remove = EDGE_SUCC (cond_block, 1)->dest; |
902929aa | 394 | } |
395 | else | |
396 | { | |
cd665a06 | 397 | EDGE_SUCC (cond_block, 1)->flags |= EDGE_FALLTHRU; |
398 | EDGE_SUCC (cond_block, 1)->flags | |
902929aa | 399 | &= ~(EDGE_TRUE_VALUE | EDGE_FALSE_VALUE); |
720cfc43 | 400 | EDGE_SUCC (cond_block, 1)->probability = profile_probability::always (); |
0e1a77e1 | 401 | |
cd665a06 | 402 | block_to_remove = EDGE_SUCC (cond_block, 0)->dest; |
902929aa | 403 | } |
0e1a77e1 | 404 | delete_basic_block (block_to_remove); |
20e5647c | 405 | |
902929aa | 406 | /* Eliminate the COND_EXPR at the end of COND_BLOCK. */ |
75a70cf9 | 407 | gsi = gsi_last_bb (cond_block); |
408 | gsi_remove (&gsi, true); | |
20e5647c | 409 | |
902929aa | 410 | if (dump_file && (dump_flags & TDF_DETAILS)) |
411 | fprintf (dump_file, | |
412 | "COND_EXPR in block %d and PHI in block %d converted to straightline code.\n", | |
413 | cond_block->index, | |
414 | bb->index); | |
415 | } | |
416 | ||
29a78fec | 417 | /* PR66726: Factor conversion out of COND_EXPR. If the arguments of the PHI |
418 | stmt are CONVERT_STMT, factor out the conversion and perform the conversion | |
8100256d | 419 | to the result of PHI stmt. COND_STMT is the controlling predicate. |
420 | Return the newly-created PHI, if any. */ | |
29a78fec | 421 | |
5dccd071 | 422 | static gphi * |
29a78fec | 423 | factor_out_conditional_conversion (edge e0, edge e1, gphi *phi, |
8100256d | 424 | tree arg0, tree arg1, gimple *cond_stmt) |
29a78fec | 425 | { |
42acab1c | 426 | gimple *arg0_def_stmt = NULL, *arg1_def_stmt = NULL, *new_stmt; |
29a78fec | 427 | tree new_arg0 = NULL_TREE, new_arg1 = NULL_TREE; |
428 | tree temp, result; | |
429 | gphi *newphi; | |
430 | gimple_stmt_iterator gsi, gsi_for_def; | |
be1e7283 | 431 | location_t locus = gimple_location (phi); |
29a78fec | 432 | enum tree_code convert_code; |
433 | ||
434 | /* Handle only PHI statements with two arguments. TODO: If all | |
435 | other arguments to PHI are INTEGER_CST or if their defining | |
436 | statement have the same unary operation, we can handle more | |
437 | than two arguments too. */ | |
438 | if (gimple_phi_num_args (phi) != 2) | |
5dccd071 | 439 | return NULL; |
29a78fec | 440 | |
441 | /* First canonicalize to simplify tests. */ | |
442 | if (TREE_CODE (arg0) != SSA_NAME) | |
443 | { | |
444 | std::swap (arg0, arg1); | |
445 | std::swap (e0, e1); | |
446 | } | |
447 | ||
448 | if (TREE_CODE (arg0) != SSA_NAME | |
449 | || (TREE_CODE (arg1) != SSA_NAME | |
450 | && TREE_CODE (arg1) != INTEGER_CST)) | |
5dccd071 | 451 | return NULL; |
29a78fec | 452 | |
453 | /* Check if arg0 is an SSA_NAME and the stmt which defines arg0 is | |
454 | a conversion. */ | |
455 | arg0_def_stmt = SSA_NAME_DEF_STMT (arg0); | |
552821b4 | 456 | if (!gimple_assign_cast_p (arg0_def_stmt)) |
5dccd071 | 457 | return NULL; |
29a78fec | 458 | |
459 | /* Use the RHS as new_arg0. */ | |
460 | convert_code = gimple_assign_rhs_code (arg0_def_stmt); | |
461 | new_arg0 = gimple_assign_rhs1 (arg0_def_stmt); | |
462 | if (convert_code == VIEW_CONVERT_EXPR) | |
552821b4 | 463 | { |
464 | new_arg0 = TREE_OPERAND (new_arg0, 0); | |
465 | if (!is_gimple_reg_type (TREE_TYPE (new_arg0))) | |
466 | return NULL; | |
467 | } | |
29a78fec | 468 | |
469 | if (TREE_CODE (arg1) == SSA_NAME) | |
470 | { | |
471 | /* Check if arg1 is an SSA_NAME and the stmt which defines arg1 | |
472 | is a conversion. */ | |
473 | arg1_def_stmt = SSA_NAME_DEF_STMT (arg1); | |
474 | if (!is_gimple_assign (arg1_def_stmt) | |
475 | || gimple_assign_rhs_code (arg1_def_stmt) != convert_code) | |
5dccd071 | 476 | return NULL; |
29a78fec | 477 | |
478 | /* Use the RHS as new_arg1. */ | |
479 | new_arg1 = gimple_assign_rhs1 (arg1_def_stmt); | |
480 | if (convert_code == VIEW_CONVERT_EXPR) | |
481 | new_arg1 = TREE_OPERAND (new_arg1, 0); | |
482 | } | |
483 | else | |
484 | { | |
485 | /* If arg1 is an INTEGER_CST, fold it to new type. */ | |
486 | if (INTEGRAL_TYPE_P (TREE_TYPE (new_arg0)) | |
487 | && int_fits_type_p (arg1, TREE_TYPE (new_arg0))) | |
488 | { | |
489 | if (gimple_assign_cast_p (arg0_def_stmt)) | |
8100256d | 490 | { |
491 | /* For the INTEGER_CST case, we are just moving the | |
492 | conversion from one place to another, which can often | |
493 | hurt as the conversion moves further away from the | |
494 | statement that computes the value. So, perform this | |
495 | only if new_arg0 is an operand of COND_STMT, or | |
496 | if arg0_def_stmt is the only non-debug stmt in | |
497 | its basic block, because then it is possible this | |
498 | could enable further optimizations (minmax replacement | |
499 | etc.). See PR71016. */ | |
500 | if (new_arg0 != gimple_cond_lhs (cond_stmt) | |
501 | && new_arg0 != gimple_cond_rhs (cond_stmt) | |
502 | && gimple_bb (arg0_def_stmt) == e0->src) | |
503 | { | |
504 | gsi = gsi_for_stmt (arg0_def_stmt); | |
505 | gsi_prev_nondebug (&gsi); | |
506 | if (!gsi_end_p (gsi)) | |
507 | return NULL; | |
508 | gsi = gsi_for_stmt (arg0_def_stmt); | |
509 | gsi_next_nondebug (&gsi); | |
510 | if (!gsi_end_p (gsi)) | |
511 | return NULL; | |
512 | } | |
513 | new_arg1 = fold_convert (TREE_TYPE (new_arg0), arg1); | |
514 | } | |
29a78fec | 515 | else |
5dccd071 | 516 | return NULL; |
29a78fec | 517 | } |
518 | else | |
5dccd071 | 519 | return NULL; |
29a78fec | 520 | } |
521 | ||
522 | /* If arg0/arg1 have > 1 use, then this transformation actually increases | |
523 | the number of expressions evaluated at runtime. */ | |
524 | if (!has_single_use (arg0) | |
525 | || (arg1_def_stmt && !has_single_use (arg1))) | |
5dccd071 | 526 | return NULL; |
29a78fec | 527 | |
528 | /* If types of new_arg0 and new_arg1 are different bailout. */ | |
529 | if (!types_compatible_p (TREE_TYPE (new_arg0), TREE_TYPE (new_arg1))) | |
5dccd071 | 530 | return NULL; |
29a78fec | 531 | |
532 | /* Create a new PHI stmt. */ | |
533 | result = PHI_RESULT (phi); | |
534 | temp = make_ssa_name (TREE_TYPE (new_arg0), NULL); | |
535 | newphi = create_phi_node (temp, gimple_bb (phi)); | |
536 | ||
537 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
538 | { | |
539 | fprintf (dump_file, "PHI "); | |
1ffa4346 | 540 | print_generic_expr (dump_file, gimple_phi_result (phi)); |
29a78fec | 541 | fprintf (dump_file, |
542 | " changed to factor conversion out from COND_EXPR.\n"); | |
543 | fprintf (dump_file, "New stmt with CAST that defines "); | |
1ffa4346 | 544 | print_generic_expr (dump_file, result); |
29a78fec | 545 | fprintf (dump_file, ".\n"); |
546 | } | |
547 | ||
548 | /* Remove the old cast(s) that has single use. */ | |
549 | gsi_for_def = gsi_for_stmt (arg0_def_stmt); | |
550 | gsi_remove (&gsi_for_def, true); | |
3f6d43bf | 551 | release_defs (arg0_def_stmt); |
552 | ||
29a78fec | 553 | if (arg1_def_stmt) |
554 | { | |
555 | gsi_for_def = gsi_for_stmt (arg1_def_stmt); | |
556 | gsi_remove (&gsi_for_def, true); | |
3f6d43bf | 557 | release_defs (arg1_def_stmt); |
29a78fec | 558 | } |
559 | ||
560 | add_phi_arg (newphi, new_arg0, e0, locus); | |
561 | add_phi_arg (newphi, new_arg1, e1, locus); | |
562 | ||
563 | /* Create the conversion stmt and insert it. */ | |
564 | if (convert_code == VIEW_CONVERT_EXPR) | |
18b3dab4 | 565 | { |
566 | temp = fold_build1 (VIEW_CONVERT_EXPR, TREE_TYPE (result), temp); | |
567 | new_stmt = gimple_build_assign (result, temp); | |
568 | } | |
569 | else | |
570 | new_stmt = gimple_build_assign (result, convert_code, temp); | |
29a78fec | 571 | gsi = gsi_after_labels (gimple_bb (phi)); |
572 | gsi_insert_before (&gsi, new_stmt, GSI_SAME_STMT); | |
573 | ||
3f6d43bf | 574 | /* Remove the original PHI stmt. */ |
29a78fec | 575 | gsi = gsi_for_stmt (phi); |
576 | gsi_remove (&gsi, true); | |
5dccd071 | 577 | return newphi; |
29a78fec | 578 | } |
579 | ||
162634aa | 580 | /* Optimize |
581 | # x_5 in range [cst1, cst2] where cst2 = cst1 + 1 | |
582 | if (x_5 op cstN) # where op is == or != and N is 1 or 2 | |
583 | goto bb3; | |
584 | else | |
585 | goto bb4; | |
586 | bb3: | |
587 | bb4: | |
588 | # r_6 = PHI<cst3(2), cst4(3)> # where cst3 == cst4 + 1 or cst4 == cst3 + 1 | |
589 | ||
590 | to r_6 = x_5 + (min (cst3, cst4) - cst1) or | |
591 | r_6 = (min (cst3, cst4) + cst1) - x_5 depending on op, N and which | |
592 | of cst3 and cst4 is smaller. */ | |
593 | ||
594 | static bool | |
595 | two_value_replacement (basic_block cond_bb, basic_block middle_bb, | |
596 | edge e1, gphi *phi, tree arg0, tree arg1) | |
597 | { | |
598 | /* Only look for adjacent integer constants. */ | |
599 | if (!INTEGRAL_TYPE_P (TREE_TYPE (arg0)) | |
600 | || !INTEGRAL_TYPE_P (TREE_TYPE (arg1)) | |
601 | || TREE_CODE (arg0) != INTEGER_CST | |
602 | || TREE_CODE (arg1) != INTEGER_CST | |
603 | || (tree_int_cst_lt (arg0, arg1) | |
604 | ? wi::to_widest (arg0) + 1 != wi::to_widest (arg1) | |
605 | : wi::to_widest (arg1) + 1 != wi::to_widest (arg1))) | |
606 | return false; | |
607 | ||
608 | if (!empty_block_p (middle_bb)) | |
609 | return false; | |
610 | ||
611 | gimple *stmt = last_stmt (cond_bb); | |
612 | tree lhs = gimple_cond_lhs (stmt); | |
613 | tree rhs = gimple_cond_rhs (stmt); | |
614 | ||
615 | if (TREE_CODE (lhs) != SSA_NAME | |
616 | || !INTEGRAL_TYPE_P (TREE_TYPE (lhs)) | |
617 | || TREE_CODE (TREE_TYPE (lhs)) == BOOLEAN_TYPE | |
618 | || TREE_CODE (rhs) != INTEGER_CST) | |
619 | return false; | |
620 | ||
621 | switch (gimple_cond_code (stmt)) | |
622 | { | |
623 | case EQ_EXPR: | |
624 | case NE_EXPR: | |
625 | break; | |
626 | default: | |
627 | return false; | |
628 | } | |
629 | ||
630 | wide_int min, max; | |
631 | if (get_range_info (lhs, &min, &max) != VR_RANGE | |
632 | || min + 1 != max | |
633 | || (wi::to_wide (rhs) != min | |
634 | && wi::to_wide (rhs) != max)) | |
635 | return false; | |
636 | ||
637 | /* We need to know which is the true edge and which is the false | |
638 | edge so that we know when to invert the condition below. */ | |
639 | edge true_edge, false_edge; | |
640 | extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge); | |
641 | if ((gimple_cond_code (stmt) == EQ_EXPR) | |
642 | ^ (wi::to_wide (rhs) == max) | |
643 | ^ (e1 == false_edge)) | |
644 | std::swap (arg0, arg1); | |
645 | ||
646 | tree type; | |
647 | if (TYPE_PRECISION (TREE_TYPE (lhs)) == TYPE_PRECISION (TREE_TYPE (arg0))) | |
648 | { | |
649 | /* Avoid performing the arithmetics in bool type which has different | |
650 | semantics, otherwise prefer unsigned types from the two with | |
651 | the same precision. */ | |
652 | if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE | |
653 | || !TYPE_UNSIGNED (TREE_TYPE (arg0))) | |
654 | type = TREE_TYPE (lhs); | |
655 | else | |
656 | type = TREE_TYPE (arg0); | |
657 | } | |
658 | else if (TYPE_PRECISION (TREE_TYPE (lhs)) > TYPE_PRECISION (TREE_TYPE (arg0))) | |
659 | type = TREE_TYPE (lhs); | |
660 | else | |
661 | type = TREE_TYPE (arg0); | |
662 | ||
663 | min = wide_int::from (min, TYPE_PRECISION (type), | |
664 | TYPE_SIGN (TREE_TYPE (lhs))); | |
665 | wide_int a = wide_int::from (wi::to_wide (arg0), TYPE_PRECISION (type), | |
666 | TYPE_SIGN (TREE_TYPE (arg0))); | |
667 | enum tree_code code; | |
668 | wi::overflow_type ovf; | |
669 | if (tree_int_cst_lt (arg0, arg1)) | |
670 | { | |
671 | code = PLUS_EXPR; | |
672 | a -= min; | |
673 | if (!TYPE_UNSIGNED (type)) | |
674 | { | |
675 | /* lhs is known to be in range [min, min+1] and we want to add a | |
676 | to it. Check if that operation can overflow for those 2 values | |
677 | and if yes, force unsigned type. */ | |
678 | wi::add (min + (wi::neg_p (a) ? 0 : 1), a, SIGNED, &ovf); | |
679 | if (ovf) | |
680 | type = unsigned_type_for (type); | |
681 | } | |
682 | } | |
683 | else | |
684 | { | |
685 | code = MINUS_EXPR; | |
686 | a += min; | |
687 | if (!TYPE_UNSIGNED (type)) | |
688 | { | |
689 | /* lhs is known to be in range [min, min+1] and we want to subtract | |
690 | it from a. Check if that operation can overflow for those 2 | |
691 | values and if yes, force unsigned type. */ | |
692 | wi::sub (a, min + (wi::neg_p (min) ? 0 : 1), SIGNED, &ovf); | |
693 | if (ovf) | |
694 | type = unsigned_type_for (type); | |
695 | } | |
696 | } | |
697 | ||
698 | tree arg = wide_int_to_tree (type, a); | |
699 | gimple_stmt_iterator gsi = gsi_for_stmt (stmt); | |
700 | if (!useless_type_conversion_p (type, TREE_TYPE (lhs))) | |
701 | lhs = gimplify_build1 (&gsi, NOP_EXPR, type, lhs); | |
702 | tree new_rhs; | |
703 | if (code == PLUS_EXPR) | |
704 | new_rhs = gimplify_build2 (&gsi, PLUS_EXPR, type, lhs, arg); | |
705 | else | |
706 | new_rhs = gimplify_build2 (&gsi, MINUS_EXPR, type, arg, lhs); | |
707 | if (!useless_type_conversion_p (TREE_TYPE (arg0), type)) | |
708 | new_rhs = gimplify_build1 (&gsi, NOP_EXPR, TREE_TYPE (arg0), new_rhs); | |
709 | ||
710 | replace_phi_edge_with_variable (cond_bb, e1, phi, new_rhs); | |
711 | ||
712 | /* Note that we optimized this PHI. */ | |
713 | return true; | |
714 | } | |
715 | ||
902929aa | 716 | /* The function conditional_replacement does the main work of doing the |
717 | conditional replacement. Return true if the replacement is done. | |
718 | Otherwise return false. | |
719 | BB is the basic block where the replacement is going to be done on. ARG0 | |
dac49aa5 | 720 | is argument 0 from PHI. Likewise for ARG1. */ |
902929aa | 721 | |
722 | static bool | |
33784d89 | 723 | conditional_replacement (basic_block cond_bb, basic_block middle_bb, |
1a91d914 | 724 | edge e0, edge e1, gphi *phi, |
33784d89 | 725 | tree arg0, tree arg1) |
902929aa | 726 | { |
727 | tree result; | |
42acab1c | 728 | gimple *stmt; |
1a91d914 | 729 | gassign *new_stmt; |
75a70cf9 | 730 | tree cond; |
731 | gimple_stmt_iterator gsi; | |
902929aa | 732 | edge true_edge, false_edge; |
75a70cf9 | 733 | tree new_var, new_var2; |
678919fd | 734 | bool neg; |
902929aa | 735 | |
435e1a75 | 736 | /* FIXME: Gimplification of complex type is too hard for now. */ |
47b88316 | 737 | /* We aren't prepared to handle vectors either (and it is a question |
738 | if it would be worthwhile anyway). */ | |
739 | if (!(INTEGRAL_TYPE_P (TREE_TYPE (arg0)) | |
740 | || POINTER_TYPE_P (TREE_TYPE (arg0))) | |
741 | || !(INTEGRAL_TYPE_P (TREE_TYPE (arg1)) | |
742 | || POINTER_TYPE_P (TREE_TYPE (arg1)))) | |
435e1a75 | 743 | return false; |
744 | ||
678919fd | 745 | /* The PHI arguments have the constants 0 and 1, or 0 and -1, then |
746 | convert it to the conditional. */ | |
902929aa | 747 | if ((integer_zerop (arg0) && integer_onep (arg1)) |
748 | || (integer_zerop (arg1) && integer_onep (arg0))) | |
678919fd | 749 | neg = false; |
750 | else if ((integer_zerop (arg0) && integer_all_onesp (arg1)) | |
751 | || (integer_zerop (arg1) && integer_all_onesp (arg0))) | |
752 | neg = true; | |
902929aa | 753 | else |
754 | return false; | |
20e5647c | 755 | |
33784d89 | 756 | if (!empty_block_p (middle_bb)) |
902929aa | 757 | return false; |
20e5647c | 758 | |
75a70cf9 | 759 | /* At this point we know we have a GIMPLE_COND with two successors. |
2ab0a163 | 760 | One successor is BB, the other successor is an empty block which |
761 | falls through into BB. | |
20e5647c | 762 | |
2ab0a163 | 763 | There is a single PHI node at the join point (BB) and its arguments |
678919fd | 764 | are constants (0, 1) or (0, -1). |
20e5647c | 765 | |
2ab0a163 | 766 | So, given the condition COND, and the two PHI arguments, we can |
20e5647c | 767 | rewrite this PHI into non-branching code: |
768 | ||
2ab0a163 | 769 | dest = (COND) or dest = COND' |
20e5647c | 770 | |
2ab0a163 | 771 | We use the condition as-is if the argument associated with the |
772 | true edge has the value one or the argument associated with the | |
773 | false edge as the value zero. Note that those conditions are not | |
75a70cf9 | 774 | the same since only one of the outgoing edges from the GIMPLE_COND |
2ab0a163 | 775 | will directly reach BB and thus be associated with an argument. */ |
ae5a4794 | 776 | |
75a70cf9 | 777 | stmt = last_stmt (cond_bb); |
778 | result = PHI_RESULT (phi); | |
b2a02a0e | 779 | |
75a70cf9 | 780 | /* To handle special cases like floating point comparison, it is easier and |
781 | less error-prone to build a tree and gimplify it on the fly though it is | |
782 | less efficient. */ | |
6f9714b3 | 783 | cond = fold_build2_loc (gimple_location (stmt), |
784 | gimple_cond_code (stmt), boolean_type_node, | |
785 | gimple_cond_lhs (stmt), gimple_cond_rhs (stmt)); | |
4ee9c684 | 786 | |
75a70cf9 | 787 | /* We need to know which is the true edge and which is the false |
788 | edge so that we know when to invert the condition below. */ | |
789 | extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge); | |
790 | if ((e0 == true_edge && integer_zerop (arg0)) | |
678919fd | 791 | || (e0 == false_edge && !integer_zerop (arg0)) |
75a70cf9 | 792 | || (e1 == true_edge && integer_zerop (arg1)) |
678919fd | 793 | || (e1 == false_edge && !integer_zerop (arg1))) |
6f9714b3 | 794 | cond = fold_build1_loc (gimple_location (stmt), |
678919fd | 795 | TRUTH_NOT_EXPR, TREE_TYPE (cond), cond); |
796 | ||
797 | if (neg) | |
798 | { | |
799 | cond = fold_convert_loc (gimple_location (stmt), | |
800 | TREE_TYPE (result), cond); | |
801 | cond = fold_build1_loc (gimple_location (stmt), | |
802 | NEGATE_EXPR, TREE_TYPE (cond), cond); | |
803 | } | |
75a70cf9 | 804 | |
805 | /* Insert our new statements at the end of conditional block before the | |
806 | COND_STMT. */ | |
807 | gsi = gsi_for_stmt (stmt); | |
808 | new_var = force_gimple_operand_gsi (&gsi, cond, true, NULL, true, | |
809 | GSI_SAME_STMT); | |
810 | ||
811 | if (!useless_type_conversion_p (TREE_TYPE (result), TREE_TYPE (new_var))) | |
812 | { | |
be1e7283 | 813 | location_t locus_0, locus_1; |
efbcb6de | 814 | |
f9e245b2 | 815 | new_var2 = make_ssa_name (TREE_TYPE (result)); |
e9cf809e | 816 | new_stmt = gimple_build_assign (new_var2, CONVERT_EXPR, new_var); |
75a70cf9 | 817 | gsi_insert_before (&gsi, new_stmt, GSI_SAME_STMT); |
818 | new_var = new_var2; | |
efbcb6de | 819 | |
820 | /* Set the locus to the first argument, unless is doesn't have one. */ | |
821 | locus_0 = gimple_phi_arg_location (phi, 0); | |
822 | locus_1 = gimple_phi_arg_location (phi, 1); | |
823 | if (locus_0 == UNKNOWN_LOCATION) | |
824 | locus_0 = locus_1; | |
825 | gimple_set_location (new_stmt, locus_0); | |
4ee9c684 | 826 | } |
20e5647c | 827 | |
75a70cf9 | 828 | replace_phi_edge_with_variable (cond_bb, e1, phi, new_var); |
902929aa | 829 | |
4ee9c684 | 830 | /* Note that we optimized this PHI. */ |
831 | return true; | |
832 | } | |
833 | ||
17b9476e | 834 | /* Update *ARG which is defined in STMT so that it contains the |
835 | computed value if that seems profitable. Return true if the | |
836 | statement is made dead by that rewriting. */ | |
837 | ||
838 | static bool | |
42acab1c | 839 | jump_function_from_stmt (tree *arg, gimple *stmt) |
17b9476e | 840 | { |
841 | enum tree_code code = gimple_assign_rhs_code (stmt); | |
842 | if (code == ADDR_EXPR) | |
843 | { | |
844 | /* For arg = &p->i transform it to p, if possible. */ | |
845 | tree rhs1 = gimple_assign_rhs1 (stmt); | |
773078cb | 846 | poly_int64 offset; |
17b9476e | 847 | tree tem = get_addr_base_and_unit_offset (TREE_OPERAND (rhs1, 0), |
848 | &offset); | |
849 | if (tem | |
850 | && TREE_CODE (tem) == MEM_REF | |
773078cb | 851 | && known_eq (mem_ref_offset (tem) + offset, 0)) |
17b9476e | 852 | { |
853 | *arg = TREE_OPERAND (tem, 0); | |
854 | return true; | |
855 | } | |
856 | } | |
857 | /* TODO: Much like IPA-CP jump-functions we want to handle constant | |
858 | additions symbolically here, and we'd need to update the comparison | |
859 | code that compares the arg + cst tuples in our caller. For now the | |
860 | code above exactly handles the VEC_BASE pattern from vec.h. */ | |
861 | return false; | |
862 | } | |
863 | ||
f32420fb | 864 | /* RHS is a source argument in a BIT_AND_EXPR which feeds a conditional |
865 | of the form SSA_NAME NE 0. | |
866 | ||
867 | If RHS is fed by a simple EQ_EXPR comparison of two values, see if | |
868 | the two input values of the EQ_EXPR match arg0 and arg1. | |
869 | ||
870 | If so update *code and return TRUE. Otherwise return FALSE. */ | |
871 | ||
872 | static bool | |
873 | rhs_is_fed_for_value_replacement (const_tree arg0, const_tree arg1, | |
874 | enum tree_code *code, const_tree rhs) | |
875 | { | |
876 | /* Obviously if RHS is not an SSA_NAME, we can't look at the defining | |
877 | statement. */ | |
878 | if (TREE_CODE (rhs) == SSA_NAME) | |
879 | { | |
42acab1c | 880 | gimple *def1 = SSA_NAME_DEF_STMT (rhs); |
f32420fb | 881 | |
882 | /* Verify the defining statement has an EQ_EXPR on the RHS. */ | |
883 | if (is_gimple_assign (def1) && gimple_assign_rhs_code (def1) == EQ_EXPR) | |
884 | { | |
885 | /* Finally verify the source operands of the EQ_EXPR are equal | |
886 | to arg0 and arg1. */ | |
887 | tree op0 = gimple_assign_rhs1 (def1); | |
888 | tree op1 = gimple_assign_rhs2 (def1); | |
889 | if ((operand_equal_for_phi_arg_p (arg0, op0) | |
890 | && operand_equal_for_phi_arg_p (arg1, op1)) | |
891 | || (operand_equal_for_phi_arg_p (arg0, op1) | |
892 | && operand_equal_for_phi_arg_p (arg1, op0))) | |
893 | { | |
894 | /* We will perform the optimization. */ | |
895 | *code = gimple_assign_rhs_code (def1); | |
896 | return true; | |
897 | } | |
898 | } | |
899 | } | |
900 | return false; | |
901 | } | |
902 | ||
903 | /* Return TRUE if arg0/arg1 are equal to the rhs/lhs or lhs/rhs of COND. | |
904 | ||
905 | Also return TRUE if arg0/arg1 are equal to the source arguments of a | |
906 | an EQ comparison feeding a BIT_AND_EXPR which feeds COND. | |
907 | ||
908 | Return FALSE otherwise. */ | |
909 | ||
910 | static bool | |
911 | operand_equal_for_value_replacement (const_tree arg0, const_tree arg1, | |
42acab1c | 912 | enum tree_code *code, gimple *cond) |
f32420fb | 913 | { |
42acab1c | 914 | gimple *def; |
f32420fb | 915 | tree lhs = gimple_cond_lhs (cond); |
916 | tree rhs = gimple_cond_rhs (cond); | |
917 | ||
918 | if ((operand_equal_for_phi_arg_p (arg0, lhs) | |
919 | && operand_equal_for_phi_arg_p (arg1, rhs)) | |
920 | || (operand_equal_for_phi_arg_p (arg1, lhs) | |
921 | && operand_equal_for_phi_arg_p (arg0, rhs))) | |
922 | return true; | |
923 | ||
924 | /* Now handle more complex case where we have an EQ comparison | |
925 | which feeds a BIT_AND_EXPR which feeds COND. | |
926 | ||
927 | First verify that COND is of the form SSA_NAME NE 0. */ | |
928 | if (*code != NE_EXPR || !integer_zerop (rhs) | |
929 | || TREE_CODE (lhs) != SSA_NAME) | |
930 | return false; | |
931 | ||
932 | /* Now ensure that SSA_NAME is set by a BIT_AND_EXPR. */ | |
933 | def = SSA_NAME_DEF_STMT (lhs); | |
934 | if (!is_gimple_assign (def) || gimple_assign_rhs_code (def) != BIT_AND_EXPR) | |
935 | return false; | |
936 | ||
937 | /* Now verify arg0/arg1 correspond to the source arguments of an | |
938 | EQ comparison feeding the BIT_AND_EXPR. */ | |
939 | ||
940 | tree tmp = gimple_assign_rhs1 (def); | |
941 | if (rhs_is_fed_for_value_replacement (arg0, arg1, code, tmp)) | |
942 | return true; | |
943 | ||
944 | tmp = gimple_assign_rhs2 (def); | |
945 | if (rhs_is_fed_for_value_replacement (arg0, arg1, code, tmp)) | |
946 | return true; | |
947 | ||
948 | return false; | |
949 | } | |
950 | ||
b6814ca0 | 951 | /* Returns true if ARG is a neutral element for operation CODE |
952 | on the RIGHT side. */ | |
953 | ||
954 | static bool | |
955 | neutral_element_p (tree_code code, tree arg, bool right) | |
956 | { | |
957 | switch (code) | |
958 | { | |
959 | case PLUS_EXPR: | |
960 | case BIT_IOR_EXPR: | |
961 | case BIT_XOR_EXPR: | |
962 | return integer_zerop (arg); | |
963 | ||
964 | case LROTATE_EXPR: | |
965 | case RROTATE_EXPR: | |
966 | case LSHIFT_EXPR: | |
967 | case RSHIFT_EXPR: | |
968 | case MINUS_EXPR: | |
969 | case POINTER_PLUS_EXPR: | |
970 | return right && integer_zerop (arg); | |
971 | ||
972 | case MULT_EXPR: | |
973 | return integer_onep (arg); | |
974 | ||
975 | case TRUNC_DIV_EXPR: | |
976 | case CEIL_DIV_EXPR: | |
977 | case FLOOR_DIV_EXPR: | |
978 | case ROUND_DIV_EXPR: | |
979 | case EXACT_DIV_EXPR: | |
980 | return right && integer_onep (arg); | |
981 | ||
982 | case BIT_AND_EXPR: | |
983 | return integer_all_onesp (arg); | |
984 | ||
985 | default: | |
986 | return false; | |
987 | } | |
988 | } | |
989 | ||
990 | /* Returns true if ARG is an absorbing element for operation CODE. */ | |
991 | ||
992 | static bool | |
2177bb9a | 993 | absorbing_element_p (tree_code code, tree arg, bool right, tree rval) |
b6814ca0 | 994 | { |
995 | switch (code) | |
996 | { | |
997 | case BIT_IOR_EXPR: | |
998 | return integer_all_onesp (arg); | |
999 | ||
1000 | case MULT_EXPR: | |
1001 | case BIT_AND_EXPR: | |
1002 | return integer_zerop (arg); | |
1003 | ||
0644c120 | 1004 | case LSHIFT_EXPR: |
1005 | case RSHIFT_EXPR: | |
1006 | case LROTATE_EXPR: | |
1007 | case RROTATE_EXPR: | |
2177bb9a | 1008 | return !right && integer_zerop (arg); |
1009 | ||
0644c120 | 1010 | case TRUNC_DIV_EXPR: |
1011 | case CEIL_DIV_EXPR: | |
1012 | case FLOOR_DIV_EXPR: | |
1013 | case ROUND_DIV_EXPR: | |
1014 | case EXACT_DIV_EXPR: | |
1015 | case TRUNC_MOD_EXPR: | |
1016 | case CEIL_MOD_EXPR: | |
1017 | case FLOOR_MOD_EXPR: | |
1018 | case ROUND_MOD_EXPR: | |
2177bb9a | 1019 | return (!right |
1020 | && integer_zerop (arg) | |
1021 | && tree_single_nonzero_warnv_p (rval, NULL)); | |
0644c120 | 1022 | |
b6814ca0 | 1023 | default: |
1024 | return false; | |
1025 | } | |
1026 | } | |
1027 | ||
0beac6fc | 1028 | /* The function value_replacement does the main work of doing the value |
fb9912ea | 1029 | replacement. Return non-zero if the replacement is done. Otherwise return |
1030 | 0. If we remove the middle basic block, return 2. | |
0beac6fc | 1031 | BB is the basic block where the replacement is going to be done on. ARG0 |
dac49aa5 | 1032 | is argument 0 from the PHI. Likewise for ARG1. */ |
0beac6fc | 1033 | |
fb9912ea | 1034 | static int |
33784d89 | 1035 | value_replacement (basic_block cond_bb, basic_block middle_bb, |
42acab1c | 1036 | edge e0, edge e1, gimple *phi, |
33784d89 | 1037 | tree arg0, tree arg1) |
0beac6fc | 1038 | { |
17b9476e | 1039 | gimple_stmt_iterator gsi; |
42acab1c | 1040 | gimple *cond; |
0beac6fc | 1041 | edge true_edge, false_edge; |
75a70cf9 | 1042 | enum tree_code code; |
fb9912ea | 1043 | bool emtpy_or_with_defined_p = true; |
0beac6fc | 1044 | |
1045 | /* If the type says honor signed zeros we cannot do this | |
dac49aa5 | 1046 | optimization. */ |
fe994837 | 1047 | if (HONOR_SIGNED_ZEROS (arg1)) |
fb9912ea | 1048 | return 0; |
0beac6fc | 1049 | |
fb9912ea | 1050 | /* If there is a statement in MIDDLE_BB that defines one of the PHI |
1051 | arguments, then adjust arg0 or arg1. */ | |
b6814ca0 | 1052 | gsi = gsi_start_nondebug_after_labels_bb (middle_bb); |
fb9912ea | 1053 | while (!gsi_end_p (gsi)) |
17b9476e | 1054 | { |
42acab1c | 1055 | gimple *stmt = gsi_stmt (gsi); |
fb9912ea | 1056 | tree lhs; |
1057 | gsi_next_nondebug (&gsi); | |
1058 | if (!is_gimple_assign (stmt)) | |
17b9476e | 1059 | { |
a2c2432d | 1060 | if (gimple_code (stmt) != GIMPLE_PREDICT |
1061 | && gimple_code (stmt) != GIMPLE_NOP) | |
1062 | emtpy_or_with_defined_p = false; | |
fb9912ea | 1063 | continue; |
17b9476e | 1064 | } |
fb9912ea | 1065 | /* Now try to adjust arg0 or arg1 according to the computation |
1066 | in the statement. */ | |
1067 | lhs = gimple_assign_lhs (stmt); | |
1068 | if (!(lhs == arg0 | |
1069 | && jump_function_from_stmt (&arg0, stmt)) | |
1070 | || (lhs == arg1 | |
1071 | && jump_function_from_stmt (&arg1, stmt))) | |
1072 | emtpy_or_with_defined_p = false; | |
17b9476e | 1073 | } |
0beac6fc | 1074 | |
75a70cf9 | 1075 | cond = last_stmt (cond_bb); |
1076 | code = gimple_cond_code (cond); | |
0beac6fc | 1077 | |
1078 | /* This transformation is only valid for equality comparisons. */ | |
75a70cf9 | 1079 | if (code != NE_EXPR && code != EQ_EXPR) |
fb9912ea | 1080 | return 0; |
0beac6fc | 1081 | |
1082 | /* We need to know which is the true edge and which is the false | |
1083 | edge so that we know if have abs or negative abs. */ | |
33784d89 | 1084 | extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge); |
0beac6fc | 1085 | |
1086 | /* At this point we know we have a COND_EXPR with two successors. | |
1087 | One successor is BB, the other successor is an empty block which | |
1088 | falls through into BB. | |
1089 | ||
1090 | The condition for the COND_EXPR is known to be NE_EXPR or EQ_EXPR. | |
1091 | ||
1092 | There is a single PHI node at the join point (BB) with two arguments. | |
1093 | ||
1094 | We now need to verify that the two arguments in the PHI node match | |
1095 | the two arguments to the equality comparison. */ | |
20e5647c | 1096 | |
f32420fb | 1097 | if (operand_equal_for_value_replacement (arg0, arg1, &code, cond)) |
0beac6fc | 1098 | { |
1099 | edge e; | |
1100 | tree arg; | |
1101 | ||
50737d20 | 1102 | /* For NE_EXPR, we want to build an assignment result = arg where |
1103 | arg is the PHI argument associated with the true edge. For | |
1104 | EQ_EXPR we want the PHI argument associated with the false edge. */ | |
75a70cf9 | 1105 | e = (code == NE_EXPR ? true_edge : false_edge); |
50737d20 | 1106 | |
1107 | /* Unfortunately, E may not reach BB (it may instead have gone to | |
1108 | OTHER_BLOCK). If that is the case, then we want the single outgoing | |
1109 | edge from OTHER_BLOCK which reaches BB and represents the desired | |
1110 | path from COND_BLOCK. */ | |
33784d89 | 1111 | if (e->dest == middle_bb) |
ea091dfd | 1112 | e = single_succ_edge (e->dest); |
50737d20 | 1113 | |
1114 | /* Now we know the incoming edge to BB that has the argument for the | |
1115 | RHS of our new assignment statement. */ | |
33784d89 | 1116 | if (e0 == e) |
0beac6fc | 1117 | arg = arg0; |
1118 | else | |
1119 | arg = arg1; | |
1120 | ||
fb9912ea | 1121 | /* If the middle basic block was empty or is defining the |
c3597b05 | 1122 | PHI arguments and this is a single phi where the args are different |
1123 | for the edges e0 and e1 then we can remove the middle basic block. */ | |
fb9912ea | 1124 | if (emtpy_or_with_defined_p |
c3597b05 | 1125 | && single_non_singleton_phi_for_edges (phi_nodes (gimple_bb (phi)), |
ce75c7c2 | 1126 | e0, e1) == phi) |
fb9912ea | 1127 | { |
1128 | replace_phi_edge_with_variable (cond_bb, e1, phi, arg); | |
1129 | /* Note that we optimized this PHI. */ | |
1130 | return 2; | |
1131 | } | |
1132 | else | |
1133 | { | |
1134 | /* Replace the PHI arguments with arg. */ | |
1135 | SET_PHI_ARG_DEF (phi, e0->dest_idx, arg); | |
1136 | SET_PHI_ARG_DEF (phi, e1->dest_idx, arg); | |
1137 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1138 | { | |
1139 | fprintf (dump_file, "PHI "); | |
1ffa4346 | 1140 | print_generic_expr (dump_file, gimple_phi_result (phi)); |
c3597b05 | 1141 | fprintf (dump_file, " reduced for COND_EXPR in block %d to ", |
1142 | cond_bb->index); | |
1ffa4346 | 1143 | print_generic_expr (dump_file, arg); |
fb9912ea | 1144 | fprintf (dump_file, ".\n"); |
1145 | } | |
1146 | return 1; | |
1147 | } | |
0beac6fc | 1148 | |
0beac6fc | 1149 | } |
b6814ca0 | 1150 | |
ae163345 | 1151 | /* Now optimize (x != 0) ? x + y : y to just x + y. */ |
1152 | gsi = gsi_last_nondebug_bb (middle_bb); | |
1153 | if (gsi_end_p (gsi)) | |
1154 | return 0; | |
1155 | ||
1156 | gimple *assign = gsi_stmt (gsi); | |
1157 | if (!is_gimple_assign (assign) | |
b6814ca0 | 1158 | || gimple_assign_rhs_class (assign) != GIMPLE_BINARY_RHS |
1159 | || (!INTEGRAL_TYPE_P (TREE_TYPE (arg0)) | |
1160 | && !POINTER_TYPE_P (TREE_TYPE (arg0)))) | |
1161 | return 0; | |
1162 | ||
6c96fe34 | 1163 | /* Punt if there are (degenerate) PHIs in middle_bb, there should not be. */ |
1164 | if (!gimple_seq_empty_p (phi_nodes (middle_bb))) | |
1165 | return 0; | |
1166 | ||
ae163345 | 1167 | /* Allow up to 2 cheap preparation statements that prepare argument |
1168 | for assign, e.g.: | |
1169 | if (y_4 != 0) | |
1170 | goto <bb 3>; | |
1171 | else | |
1172 | goto <bb 4>; | |
1173 | <bb 3>: | |
1174 | _1 = (int) y_4; | |
1175 | iftmp.0_6 = x_5(D) r<< _1; | |
1176 | <bb 4>: | |
1177 | # iftmp.0_2 = PHI <iftmp.0_6(3), x_5(D)(2)> | |
1178 | or: | |
1179 | if (y_3(D) == 0) | |
1180 | goto <bb 4>; | |
1181 | else | |
1182 | goto <bb 3>; | |
1183 | <bb 3>: | |
1184 | y_4 = y_3(D) & 31; | |
1185 | _1 = (int) y_4; | |
1186 | _6 = x_5(D) r<< _1; | |
1187 | <bb 4>: | |
1188 | # _2 = PHI <x_5(D)(2), _6(3)> */ | |
1189 | gimple *prep_stmt[2] = { NULL, NULL }; | |
1190 | int prep_cnt; | |
1191 | for (prep_cnt = 0; ; prep_cnt++) | |
1192 | { | |
1193 | gsi_prev_nondebug (&gsi); | |
1194 | if (gsi_end_p (gsi)) | |
1195 | break; | |
1196 | ||
1197 | gimple *g = gsi_stmt (gsi); | |
1198 | if (gimple_code (g) == GIMPLE_LABEL) | |
1199 | break; | |
1200 | ||
1201 | if (prep_cnt == 2 || !is_gimple_assign (g)) | |
1202 | return 0; | |
1203 | ||
1204 | tree lhs = gimple_assign_lhs (g); | |
1205 | tree rhs1 = gimple_assign_rhs1 (g); | |
1206 | use_operand_p use_p; | |
1207 | gimple *use_stmt; | |
1208 | if (TREE_CODE (lhs) != SSA_NAME | |
1209 | || TREE_CODE (rhs1) != SSA_NAME | |
1210 | || !INTEGRAL_TYPE_P (TREE_TYPE (lhs)) | |
1211 | || !INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) | |
1212 | || !single_imm_use (lhs, &use_p, &use_stmt) | |
1213 | || use_stmt != (prep_cnt ? prep_stmt[prep_cnt - 1] : assign)) | |
1214 | return 0; | |
1215 | switch (gimple_assign_rhs_code (g)) | |
1216 | { | |
1217 | CASE_CONVERT: | |
1218 | break; | |
1219 | case PLUS_EXPR: | |
1220 | case BIT_AND_EXPR: | |
1221 | case BIT_IOR_EXPR: | |
1222 | case BIT_XOR_EXPR: | |
1223 | if (TREE_CODE (gimple_assign_rhs2 (g)) != INTEGER_CST) | |
1224 | return 0; | |
1225 | break; | |
1226 | default: | |
1227 | return 0; | |
1228 | } | |
1229 | prep_stmt[prep_cnt] = g; | |
1230 | } | |
1231 | ||
43fbec4a | 1232 | /* Only transform if it removes the condition. */ |
1233 | if (!single_non_singleton_phi_for_edges (phi_nodes (gimple_bb (phi)), e0, e1)) | |
1234 | return 0; | |
1235 | ||
b6814ca0 | 1236 | /* Size-wise, this is always profitable. */ |
1237 | if (optimize_bb_for_speed_p (cond_bb) | |
1238 | /* The special case is useless if it has a low probability. */ | |
1239 | && profile_status_for_fn (cfun) != PROFILE_ABSENT | |
720cfc43 | 1240 | && EDGE_PRED (middle_bb, 0)->probability < profile_probability::even () |
b6814ca0 | 1241 | /* If assign is cheap, there is no point avoiding it. */ |
ae163345 | 1242 | && estimate_num_insns (bb_seq (middle_bb), &eni_time_weights) |
b6814ca0 | 1243 | >= 3 * estimate_num_insns (cond, &eni_time_weights)) |
1244 | return 0; | |
1245 | ||
1246 | tree lhs = gimple_assign_lhs (assign); | |
1247 | tree rhs1 = gimple_assign_rhs1 (assign); | |
1248 | tree rhs2 = gimple_assign_rhs2 (assign); | |
1249 | enum tree_code code_def = gimple_assign_rhs_code (assign); | |
1250 | tree cond_lhs = gimple_cond_lhs (cond); | |
1251 | tree cond_rhs = gimple_cond_rhs (cond); | |
1252 | ||
ae163345 | 1253 | /* Propagate the cond_rhs constant through preparation stmts, |
1254 | make sure UB isn't invoked while doing that. */ | |
1255 | for (int i = prep_cnt - 1; i >= 0; --i) | |
1256 | { | |
1257 | gimple *g = prep_stmt[i]; | |
1258 | tree grhs1 = gimple_assign_rhs1 (g); | |
1259 | if (!operand_equal_for_phi_arg_p (cond_lhs, grhs1)) | |
1260 | return 0; | |
1261 | cond_lhs = gimple_assign_lhs (g); | |
1262 | cond_rhs = fold_convert (TREE_TYPE (grhs1), cond_rhs); | |
1263 | if (TREE_CODE (cond_rhs) != INTEGER_CST | |
1264 | || TREE_OVERFLOW (cond_rhs)) | |
1265 | return 0; | |
1266 | if (gimple_assign_rhs_class (g) == GIMPLE_BINARY_RHS) | |
1267 | { | |
1268 | cond_rhs = int_const_binop (gimple_assign_rhs_code (g), cond_rhs, | |
1269 | gimple_assign_rhs2 (g)); | |
1270 | if (TREE_OVERFLOW (cond_rhs)) | |
1271 | return 0; | |
1272 | } | |
1273 | cond_rhs = fold_convert (TREE_TYPE (cond_lhs), cond_rhs); | |
1274 | if (TREE_CODE (cond_rhs) != INTEGER_CST | |
1275 | || TREE_OVERFLOW (cond_rhs)) | |
1276 | return 0; | |
1277 | } | |
1278 | ||
b6814ca0 | 1279 | if (((code == NE_EXPR && e1 == false_edge) |
1280 | || (code == EQ_EXPR && e1 == true_edge)) | |
1281 | && arg0 == lhs | |
1282 | && ((arg1 == rhs1 | |
1283 | && operand_equal_for_phi_arg_p (rhs2, cond_lhs) | |
1284 | && neutral_element_p (code_def, cond_rhs, true)) | |
1285 | || (arg1 == rhs2 | |
1286 | && operand_equal_for_phi_arg_p (rhs1, cond_lhs) | |
1287 | && neutral_element_p (code_def, cond_rhs, false)) | |
1288 | || (operand_equal_for_phi_arg_p (arg1, cond_rhs) | |
0644c120 | 1289 | && ((operand_equal_for_phi_arg_p (rhs2, cond_lhs) |
2177bb9a | 1290 | && absorbing_element_p (code_def, cond_rhs, true, rhs2)) |
0644c120 | 1291 | || (operand_equal_for_phi_arg_p (rhs1, cond_lhs) |
2177bb9a | 1292 | && absorbing_element_p (code_def, |
1293 | cond_rhs, false, rhs2)))))) | |
b6814ca0 | 1294 | { |
1295 | gsi = gsi_for_stmt (cond); | |
4e47d7a1 | 1296 | /* Moving ASSIGN might change VR of lhs, e.g. when moving u_6 |
1297 | def-stmt in: | |
1298 | if (n_5 != 0) | |
1299 | goto <bb 3>; | |
1300 | else | |
1301 | goto <bb 4>; | |
1302 | ||
1303 | <bb 3>: | |
1304 | # RANGE [0, 4294967294] | |
1305 | u_6 = n_5 + 4294967295; | |
1306 | ||
1307 | <bb 4>: | |
1308 | # u_3 = PHI <u_6(3), 4294967295(2)> */ | |
1309 | reset_flow_sensitive_info (lhs); | |
18c06fb8 | 1310 | if (INTEGRAL_TYPE_P (TREE_TYPE (lhs))) |
1311 | { | |
18c06fb8 | 1312 | /* If available, we can use VR of phi result at least. */ |
1313 | tree phires = gimple_phi_result (phi); | |
1314 | struct range_info_def *phires_range_info | |
1315 | = SSA_NAME_RANGE_INFO (phires); | |
1316 | if (phires_range_info) | |
1317 | duplicate_ssa_name_range_info (lhs, SSA_NAME_RANGE_TYPE (phires), | |
1318 | phires_range_info); | |
1319 | } | |
ae163345 | 1320 | gimple_stmt_iterator gsi_from; |
1321 | for (int i = prep_cnt - 1; i >= 0; --i) | |
1322 | { | |
1323 | tree plhs = gimple_assign_lhs (prep_stmt[i]); | |
4e47d7a1 | 1324 | reset_flow_sensitive_info (plhs); |
ae163345 | 1325 | gsi_from = gsi_for_stmt (prep_stmt[i]); |
1326 | gsi_move_before (&gsi_from, &gsi); | |
1327 | } | |
1328 | gsi_from = gsi_for_stmt (assign); | |
b6814ca0 | 1329 | gsi_move_before (&gsi_from, &gsi); |
1330 | replace_phi_edge_with_variable (cond_bb, e1, phi, lhs); | |
1331 | return 2; | |
1332 | } | |
1333 | ||
fb9912ea | 1334 | return 0; |
0beac6fc | 1335 | } |
1336 | ||
194899bf | 1337 | /* The function minmax_replacement does the main work of doing the minmax |
1338 | replacement. Return true if the replacement is done. Otherwise return | |
1339 | false. | |
1340 | BB is the basic block where the replacement is going to be done on. ARG0 | |
1341 | is argument 0 from the PHI. Likewise for ARG1. */ | |
1342 | ||
1343 | static bool | |
1344 | minmax_replacement (basic_block cond_bb, basic_block middle_bb, | |
42acab1c | 1345 | edge e0, edge e1, gimple *phi, |
194899bf | 1346 | tree arg0, tree arg1) |
1347 | { | |
28a01ce7 | 1348 | tree result, type, rhs; |
1a91d914 | 1349 | gcond *cond; |
1350 | gassign *new_stmt; | |
194899bf | 1351 | edge true_edge, false_edge; |
1352 | enum tree_code cmp, minmax, ass_code; | |
74201dc2 | 1353 | tree smaller, alt_smaller, larger, alt_larger, arg_true, arg_false; |
75a70cf9 | 1354 | gimple_stmt_iterator gsi, gsi_from; |
194899bf | 1355 | |
1356 | type = TREE_TYPE (PHI_RESULT (phi)); | |
1357 | ||
1358 | /* The optimization may be unsafe due to NaNs. */ | |
b0ab3ca0 | 1359 | if (HONOR_NANS (type) || HONOR_SIGNED_ZEROS (type)) |
194899bf | 1360 | return false; |
1361 | ||
1a91d914 | 1362 | cond = as_a <gcond *> (last_stmt (cond_bb)); |
75a70cf9 | 1363 | cmp = gimple_cond_code (cond); |
28a01ce7 | 1364 | rhs = gimple_cond_rhs (cond); |
1365 | ||
1366 | /* Turn EQ/NE of extreme values to order comparisons. */ | |
1367 | if ((cmp == NE_EXPR || cmp == EQ_EXPR) | |
1368 | && TREE_CODE (rhs) == INTEGER_CST) | |
1369 | { | |
1370 | if (wi::eq_p (wi::to_wide (rhs), wi::min_value (TREE_TYPE (rhs)))) | |
1371 | { | |
1372 | cmp = (cmp == EQ_EXPR) ? LT_EXPR : GE_EXPR; | |
1373 | rhs = wide_int_to_tree (TREE_TYPE (rhs), | |
1374 | wi::min_value (TREE_TYPE (rhs)) + 1); | |
1375 | } | |
1376 | else if (wi::eq_p (wi::to_wide (rhs), wi::max_value (TREE_TYPE (rhs)))) | |
1377 | { | |
1378 | cmp = (cmp == EQ_EXPR) ? GT_EXPR : LE_EXPR; | |
1379 | rhs = wide_int_to_tree (TREE_TYPE (rhs), | |
1380 | wi::max_value (TREE_TYPE (rhs)) - 1); | |
1381 | } | |
1382 | } | |
194899bf | 1383 | |
1384 | /* This transformation is only valid for order comparisons. Record which | |
1385 | operand is smaller/larger if the result of the comparison is true. */ | |
74201dc2 | 1386 | alt_smaller = NULL_TREE; |
1387 | alt_larger = NULL_TREE; | |
194899bf | 1388 | if (cmp == LT_EXPR || cmp == LE_EXPR) |
1389 | { | |
75a70cf9 | 1390 | smaller = gimple_cond_lhs (cond); |
28a01ce7 | 1391 | larger = rhs; |
74201dc2 | 1392 | /* If we have smaller < CST it is equivalent to smaller <= CST-1. |
1393 | Likewise smaller <= CST is equivalent to smaller < CST+1. */ | |
1394 | if (TREE_CODE (larger) == INTEGER_CST) | |
1395 | { | |
1396 | if (cmp == LT_EXPR) | |
1397 | { | |
30b5769f | 1398 | wi::overflow_type overflow; |
e3d0f65c | 1399 | wide_int alt = wi::sub (wi::to_wide (larger), 1, |
1400 | TYPE_SIGN (TREE_TYPE (larger)), | |
74201dc2 | 1401 | &overflow); |
1402 | if (! overflow) | |
1403 | alt_larger = wide_int_to_tree (TREE_TYPE (larger), alt); | |
1404 | } | |
1405 | else | |
1406 | { | |
30b5769f | 1407 | wi::overflow_type overflow; |
e3d0f65c | 1408 | wide_int alt = wi::add (wi::to_wide (larger), 1, |
1409 | TYPE_SIGN (TREE_TYPE (larger)), | |
74201dc2 | 1410 | &overflow); |
1411 | if (! overflow) | |
1412 | alt_larger = wide_int_to_tree (TREE_TYPE (larger), alt); | |
1413 | } | |
1414 | } | |
194899bf | 1415 | } |
1416 | else if (cmp == GT_EXPR || cmp == GE_EXPR) | |
1417 | { | |
28a01ce7 | 1418 | smaller = rhs; |
75a70cf9 | 1419 | larger = gimple_cond_lhs (cond); |
74201dc2 | 1420 | /* If we have larger > CST it is equivalent to larger >= CST+1. |
1421 | Likewise larger >= CST is equivalent to larger > CST-1. */ | |
1422 | if (TREE_CODE (smaller) == INTEGER_CST) | |
1423 | { | |
30b5769f | 1424 | wi::overflow_type overflow; |
74201dc2 | 1425 | if (cmp == GT_EXPR) |
1426 | { | |
e3d0f65c | 1427 | wide_int alt = wi::add (wi::to_wide (smaller), 1, |
1428 | TYPE_SIGN (TREE_TYPE (smaller)), | |
74201dc2 | 1429 | &overflow); |
1430 | if (! overflow) | |
1431 | alt_smaller = wide_int_to_tree (TREE_TYPE (smaller), alt); | |
1432 | } | |
1433 | else | |
1434 | { | |
e3d0f65c | 1435 | wide_int alt = wi::sub (wi::to_wide (smaller), 1, |
1436 | TYPE_SIGN (TREE_TYPE (smaller)), | |
74201dc2 | 1437 | &overflow); |
1438 | if (! overflow) | |
1439 | alt_smaller = wide_int_to_tree (TREE_TYPE (smaller), alt); | |
1440 | } | |
1441 | } | |
194899bf | 1442 | } |
1443 | else | |
1444 | return false; | |
1445 | ||
1446 | /* We need to know which is the true edge and which is the false | |
1447 | edge so that we know if have abs or negative abs. */ | |
1448 | extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge); | |
1449 | ||
1450 | /* Forward the edges over the middle basic block. */ | |
1451 | if (true_edge->dest == middle_bb) | |
1452 | true_edge = EDGE_SUCC (true_edge->dest, 0); | |
1453 | if (false_edge->dest == middle_bb) | |
1454 | false_edge = EDGE_SUCC (false_edge->dest, 0); | |
1455 | ||
1456 | if (true_edge == e0) | |
1457 | { | |
1458 | gcc_assert (false_edge == e1); | |
1459 | arg_true = arg0; | |
1460 | arg_false = arg1; | |
1461 | } | |
1462 | else | |
1463 | { | |
1464 | gcc_assert (false_edge == e0); | |
1465 | gcc_assert (true_edge == e1); | |
1466 | arg_true = arg1; | |
1467 | arg_false = arg0; | |
1468 | } | |
1469 | ||
1470 | if (empty_block_p (middle_bb)) | |
1471 | { | |
74201dc2 | 1472 | if ((operand_equal_for_phi_arg_p (arg_true, smaller) |
1473 | || (alt_smaller | |
1474 | && operand_equal_for_phi_arg_p (arg_true, alt_smaller))) | |
1475 | && (operand_equal_for_phi_arg_p (arg_false, larger) | |
1476 | || (alt_larger | |
1477 | && operand_equal_for_phi_arg_p (arg_true, alt_larger)))) | |
194899bf | 1478 | { |
1479 | /* Case | |
48e1416a | 1480 | |
194899bf | 1481 | if (smaller < larger) |
1482 | rslt = smaller; | |
1483 | else | |
1484 | rslt = larger; */ | |
1485 | minmax = MIN_EXPR; | |
1486 | } | |
74201dc2 | 1487 | else if ((operand_equal_for_phi_arg_p (arg_false, smaller) |
1488 | || (alt_smaller | |
1489 | && operand_equal_for_phi_arg_p (arg_false, alt_smaller))) | |
1490 | && (operand_equal_for_phi_arg_p (arg_true, larger) | |
1491 | || (alt_larger | |
1492 | && operand_equal_for_phi_arg_p (arg_true, alt_larger)))) | |
194899bf | 1493 | minmax = MAX_EXPR; |
1494 | else | |
1495 | return false; | |
1496 | } | |
1497 | else | |
1498 | { | |
1499 | /* Recognize the following case, assuming d <= u: | |
1500 | ||
1501 | if (a <= u) | |
1502 | b = MAX (a, d); | |
1503 | x = PHI <b, u> | |
1504 | ||
1505 | This is equivalent to | |
1506 | ||
1507 | b = MAX (a, d); | |
1508 | x = MIN (b, u); */ | |
1509 | ||
42acab1c | 1510 | gimple *assign = last_and_only_stmt (middle_bb); |
75a70cf9 | 1511 | tree lhs, op0, op1, bound; |
194899bf | 1512 | |
1513 | if (!assign | |
75a70cf9 | 1514 | || gimple_code (assign) != GIMPLE_ASSIGN) |
194899bf | 1515 | return false; |
1516 | ||
75a70cf9 | 1517 | lhs = gimple_assign_lhs (assign); |
1518 | ass_code = gimple_assign_rhs_code (assign); | |
194899bf | 1519 | if (ass_code != MAX_EXPR && ass_code != MIN_EXPR) |
1520 | return false; | |
75a70cf9 | 1521 | op0 = gimple_assign_rhs1 (assign); |
1522 | op1 = gimple_assign_rhs2 (assign); | |
194899bf | 1523 | |
1524 | if (true_edge->src == middle_bb) | |
1525 | { | |
1526 | /* We got here if the condition is true, i.e., SMALLER < LARGER. */ | |
1527 | if (!operand_equal_for_phi_arg_p (lhs, arg_true)) | |
1528 | return false; | |
1529 | ||
74201dc2 | 1530 | if (operand_equal_for_phi_arg_p (arg_false, larger) |
1531 | || (alt_larger | |
1532 | && operand_equal_for_phi_arg_p (arg_false, alt_larger))) | |
194899bf | 1533 | { |
1534 | /* Case | |
1535 | ||
1536 | if (smaller < larger) | |
1537 | { | |
1538 | r' = MAX_EXPR (smaller, bound) | |
1539 | } | |
1540 | r = PHI <r', larger> --> to be turned to MIN_EXPR. */ | |
1541 | if (ass_code != MAX_EXPR) | |
1542 | return false; | |
1543 | ||
1544 | minmax = MIN_EXPR; | |
74201dc2 | 1545 | if (operand_equal_for_phi_arg_p (op0, smaller) |
1546 | || (alt_smaller | |
1547 | && operand_equal_for_phi_arg_p (op0, alt_smaller))) | |
194899bf | 1548 | bound = op1; |
74201dc2 | 1549 | else if (operand_equal_for_phi_arg_p (op1, smaller) |
1550 | || (alt_smaller | |
1551 | && operand_equal_for_phi_arg_p (op1, alt_smaller))) | |
194899bf | 1552 | bound = op0; |
1553 | else | |
1554 | return false; | |
1555 | ||
1556 | /* We need BOUND <= LARGER. */ | |
49d00087 | 1557 | if (!integer_nonzerop (fold_build2 (LE_EXPR, boolean_type_node, |
1558 | bound, larger))) | |
194899bf | 1559 | return false; |
1560 | } | |
74201dc2 | 1561 | else if (operand_equal_for_phi_arg_p (arg_false, smaller) |
1562 | || (alt_smaller | |
1563 | && operand_equal_for_phi_arg_p (arg_false, alt_smaller))) | |
194899bf | 1564 | { |
1565 | /* Case | |
1566 | ||
1567 | if (smaller < larger) | |
1568 | { | |
1569 | r' = MIN_EXPR (larger, bound) | |
1570 | } | |
1571 | r = PHI <r', smaller> --> to be turned to MAX_EXPR. */ | |
1572 | if (ass_code != MIN_EXPR) | |
1573 | return false; | |
1574 | ||
1575 | minmax = MAX_EXPR; | |
74201dc2 | 1576 | if (operand_equal_for_phi_arg_p (op0, larger) |
1577 | || (alt_larger | |
1578 | && operand_equal_for_phi_arg_p (op0, alt_larger))) | |
194899bf | 1579 | bound = op1; |
74201dc2 | 1580 | else if (operand_equal_for_phi_arg_p (op1, larger) |
1581 | || (alt_larger | |
1582 | && operand_equal_for_phi_arg_p (op1, alt_larger))) | |
194899bf | 1583 | bound = op0; |
1584 | else | |
1585 | return false; | |
1586 | ||
1587 | /* We need BOUND >= SMALLER. */ | |
49d00087 | 1588 | if (!integer_nonzerop (fold_build2 (GE_EXPR, boolean_type_node, |
1589 | bound, smaller))) | |
194899bf | 1590 | return false; |
1591 | } | |
1592 | else | |
1593 | return false; | |
1594 | } | |
1595 | else | |
1596 | { | |
1597 | /* We got here if the condition is false, i.e., SMALLER > LARGER. */ | |
1598 | if (!operand_equal_for_phi_arg_p (lhs, arg_false)) | |
1599 | return false; | |
1600 | ||
74201dc2 | 1601 | if (operand_equal_for_phi_arg_p (arg_true, larger) |
1602 | || (alt_larger | |
1603 | && operand_equal_for_phi_arg_p (arg_true, alt_larger))) | |
194899bf | 1604 | { |
1605 | /* Case | |
1606 | ||
1607 | if (smaller > larger) | |
1608 | { | |
1609 | r' = MIN_EXPR (smaller, bound) | |
1610 | } | |
1611 | r = PHI <r', larger> --> to be turned to MAX_EXPR. */ | |
1612 | if (ass_code != MIN_EXPR) | |
1613 | return false; | |
1614 | ||
1615 | minmax = MAX_EXPR; | |
74201dc2 | 1616 | if (operand_equal_for_phi_arg_p (op0, smaller) |
1617 | || (alt_smaller | |
1618 | && operand_equal_for_phi_arg_p (op0, alt_smaller))) | |
194899bf | 1619 | bound = op1; |
74201dc2 | 1620 | else if (operand_equal_for_phi_arg_p (op1, smaller) |
1621 | || (alt_smaller | |
1622 | && operand_equal_for_phi_arg_p (op1, alt_smaller))) | |
194899bf | 1623 | bound = op0; |
1624 | else | |
1625 | return false; | |
1626 | ||
1627 | /* We need BOUND >= LARGER. */ | |
49d00087 | 1628 | if (!integer_nonzerop (fold_build2 (GE_EXPR, boolean_type_node, |
1629 | bound, larger))) | |
194899bf | 1630 | return false; |
1631 | } | |
74201dc2 | 1632 | else if (operand_equal_for_phi_arg_p (arg_true, smaller) |
1633 | || (alt_smaller | |
1634 | && operand_equal_for_phi_arg_p (arg_true, alt_smaller))) | |
194899bf | 1635 | { |
1636 | /* Case | |
1637 | ||
1638 | if (smaller > larger) | |
1639 | { | |
1640 | r' = MAX_EXPR (larger, bound) | |
1641 | } | |
1642 | r = PHI <r', smaller> --> to be turned to MIN_EXPR. */ | |
1643 | if (ass_code != MAX_EXPR) | |
1644 | return false; | |
1645 | ||
1646 | minmax = MIN_EXPR; | |
1647 | if (operand_equal_for_phi_arg_p (op0, larger)) | |
1648 | bound = op1; | |
1649 | else if (operand_equal_for_phi_arg_p (op1, larger)) | |
1650 | bound = op0; | |
1651 | else | |
1652 | return false; | |
1653 | ||
1654 | /* We need BOUND <= SMALLER. */ | |
49d00087 | 1655 | if (!integer_nonzerop (fold_build2 (LE_EXPR, boolean_type_node, |
1656 | bound, smaller))) | |
194899bf | 1657 | return false; |
1658 | } | |
1659 | else | |
1660 | return false; | |
1661 | } | |
1662 | ||
1663 | /* Move the statement from the middle block. */ | |
75a70cf9 | 1664 | gsi = gsi_last_bb (cond_bb); |
445a6ba5 | 1665 | gsi_from = gsi_last_nondebug_bb (middle_bb); |
4e47d7a1 | 1666 | reset_flow_sensitive_info (SINGLE_SSA_TREE_OPERAND (gsi_stmt (gsi_from), |
1667 | SSA_OP_DEF)); | |
75a70cf9 | 1668 | gsi_move_before (&gsi_from, &gsi); |
194899bf | 1669 | } |
1670 | ||
9b604bc1 | 1671 | /* Create an SSA var to hold the min/max result. If we're the only |
1672 | things setting the target PHI, then we can clone the PHI | |
1673 | variable. Otherwise we must create a new one. */ | |
1674 | result = PHI_RESULT (phi); | |
1675 | if (EDGE_COUNT (gimple_bb (phi)->preds) == 2) | |
1676 | result = duplicate_ssa_name (result, NULL); | |
1677 | else | |
1678 | result = make_ssa_name (TREE_TYPE (result)); | |
1679 | ||
194899bf | 1680 | /* Emit the statement to compute min/max. */ |
e9cf809e | 1681 | new_stmt = gimple_build_assign (result, minmax, arg0, arg1); |
75a70cf9 | 1682 | gsi = gsi_last_bb (cond_bb); |
1683 | gsi_insert_before (&gsi, new_stmt, GSI_NEW_STMT); | |
194899bf | 1684 | |
a4844041 | 1685 | replace_phi_edge_with_variable (cond_bb, e1, phi, result); |
8c1ab18f | 1686 | |
194899bf | 1687 | return true; |
1688 | } | |
1689 | ||
a75cc7d9 | 1690 | /* Convert |
1691 | ||
1692 | <bb 2> | |
1693 | if (b_4(D) != 0) | |
1694 | goto <bb 3> | |
1695 | else | |
1696 | goto <bb 4> | |
1697 | ||
1698 | <bb 3> | |
1699 | _2 = (unsigned long) b_4(D); | |
1700 | _9 = __builtin_popcountl (_2); | |
1701 | OR | |
1702 | _9 = __builtin_popcountl (b_4(D)); | |
1703 | ||
1704 | <bb 4> | |
1705 | c_12 = PHI <0(2), _9(3)> | |
1706 | ||
1707 | Into | |
1708 | <bb 2> | |
1709 | _2 = (unsigned long) b_4(D); | |
1710 | _9 = __builtin_popcountl (_2); | |
1711 | OR | |
1712 | _9 = __builtin_popcountl (b_4(D)); | |
1713 | ||
1714 | <bb 4> | |
1715 | c_12 = PHI <_9(2)> | |
1716 | */ | |
1717 | ||
1718 | static bool | |
1719 | cond_removal_in_popcount_pattern (basic_block cond_bb, basic_block middle_bb, | |
1720 | edge e1, edge e2, | |
1721 | gimple *phi, tree arg0, tree arg1) | |
1722 | { | |
1723 | gimple *cond; | |
1724 | gimple_stmt_iterator gsi, gsi_from; | |
1725 | gimple *popcount; | |
1726 | gimple *cast = NULL; | |
1727 | tree lhs, arg; | |
1728 | ||
1729 | /* Check that | |
1730 | _2 = (unsigned long) b_4(D); | |
1731 | _9 = __builtin_popcountl (_2); | |
1732 | OR | |
1733 | _9 = __builtin_popcountl (b_4(D)); | |
1734 | are the only stmts in the middle_bb. */ | |
1735 | ||
1736 | gsi = gsi_start_nondebug_after_labels_bb (middle_bb); | |
1737 | if (gsi_end_p (gsi)) | |
1738 | return false; | |
1739 | cast = gsi_stmt (gsi); | |
1740 | gsi_next_nondebug (&gsi); | |
1741 | if (!gsi_end_p (gsi)) | |
1742 | { | |
1743 | popcount = gsi_stmt (gsi); | |
1744 | gsi_next_nondebug (&gsi); | |
1745 | if (!gsi_end_p (gsi)) | |
1746 | return false; | |
1747 | } | |
1748 | else | |
1749 | { | |
1750 | popcount = cast; | |
1751 | cast = NULL; | |
1752 | } | |
1753 | ||
1754 | /* Check that we have a popcount builtin. */ | |
1755 | if (!is_gimple_call (popcount)) | |
1756 | return false; | |
1757 | combined_fn cfn = gimple_call_combined_fn (popcount); | |
1758 | switch (cfn) | |
1759 | { | |
1760 | CASE_CFN_POPCOUNT: | |
1761 | break; | |
1762 | default: | |
1763 | return false; | |
1764 | } | |
1765 | ||
1766 | arg = gimple_call_arg (popcount, 0); | |
1767 | lhs = gimple_get_lhs (popcount); | |
1768 | ||
1769 | if (cast) | |
1770 | { | |
1771 | /* We have a cast stmt feeding popcount builtin. */ | |
1772 | /* Check that we have a cast prior to that. */ | |
1773 | if (gimple_code (cast) != GIMPLE_ASSIGN | |
1774 | || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (cast))) | |
1775 | return false; | |
1776 | /* Result of the cast stmt is the argument to the builtin. */ | |
1777 | if (arg != gimple_assign_lhs (cast)) | |
1778 | return false; | |
1779 | arg = gimple_assign_rhs1 (cast); | |
1780 | } | |
1781 | ||
b91a85f5 | 1782 | cond = last_stmt (cond_bb); |
1783 | ||
1784 | /* Cond_bb has a check for b_4 [!=|==] 0 before calling the popcount | |
1785 | builtin. */ | |
1786 | if (gimple_code (cond) != GIMPLE_COND | |
1787 | || (gimple_cond_code (cond) != NE_EXPR | |
1788 | && gimple_cond_code (cond) != EQ_EXPR) | |
1789 | || !integer_zerop (gimple_cond_rhs (cond)) | |
1790 | || arg != gimple_cond_lhs (cond)) | |
1791 | return false; | |
1792 | ||
a75cc7d9 | 1793 | /* Canonicalize. */ |
b91a85f5 | 1794 | if ((e2->flags & EDGE_TRUE_VALUE |
1795 | && gimple_cond_code (cond) == NE_EXPR) | |
1796 | || (e1->flags & EDGE_TRUE_VALUE | |
1797 | && gimple_cond_code (cond) == EQ_EXPR)) | |
a75cc7d9 | 1798 | { |
1799 | std::swap (arg0, arg1); | |
1800 | std::swap (e1, e2); | |
1801 | } | |
1802 | ||
1803 | /* Check PHI arguments. */ | |
1804 | if (lhs != arg0 || !integer_zerop (arg1)) | |
1805 | return false; | |
1806 | ||
a75cc7d9 | 1807 | /* And insert the popcount builtin and cast stmt before the cond_bb. */ |
1808 | gsi = gsi_last_bb (cond_bb); | |
1809 | if (cast) | |
1810 | { | |
1811 | gsi_from = gsi_for_stmt (cast); | |
1812 | gsi_move_before (&gsi_from, &gsi); | |
1813 | reset_flow_sensitive_info (gimple_get_lhs (cast)); | |
1814 | } | |
1815 | gsi_from = gsi_for_stmt (popcount); | |
1816 | gsi_move_before (&gsi_from, &gsi); | |
1817 | reset_flow_sensitive_info (gimple_get_lhs (popcount)); | |
1818 | ||
1819 | /* Now update the PHI and remove unneeded bbs. */ | |
1820 | replace_phi_edge_with_variable (cond_bb, e2, phi, lhs); | |
1821 | return true; | |
1822 | } | |
1823 | ||
70512b93 | 1824 | /* The function absolute_replacement does the main work of doing the absolute |
1825 | replacement. Return true if the replacement is done. Otherwise return | |
1826 | false. | |
1827 | bb is the basic block where the replacement is going to be done on. arg0 | |
f7f07c95 | 1828 | is argument 0 from the phi. Likewise for arg1. */ |
33784d89 | 1829 | |
70512b93 | 1830 | static bool |
33784d89 | 1831 | abs_replacement (basic_block cond_bb, basic_block middle_bb, |
a4844041 | 1832 | edge e0 ATTRIBUTE_UNUSED, edge e1, |
42acab1c | 1833 | gimple *phi, tree arg0, tree arg1) |
70512b93 | 1834 | { |
1835 | tree result; | |
1a91d914 | 1836 | gassign *new_stmt; |
42acab1c | 1837 | gimple *cond; |
75a70cf9 | 1838 | gimple_stmt_iterator gsi; |
70512b93 | 1839 | edge true_edge, false_edge; |
42acab1c | 1840 | gimple *assign; |
70512b93 | 1841 | edge e; |
194899bf | 1842 | tree rhs, lhs; |
70512b93 | 1843 | bool negate; |
1844 | enum tree_code cond_code; | |
1845 | ||
1846 | /* If the type says honor signed zeros we cannot do this | |
dac49aa5 | 1847 | optimization. */ |
fe994837 | 1848 | if (HONOR_SIGNED_ZEROS (arg1)) |
70512b93 | 1849 | return false; |
1850 | ||
70512b93 | 1851 | /* OTHER_BLOCK must have only one executable statement which must have the |
1852 | form arg0 = -arg1 or arg1 = -arg0. */ | |
70512b93 | 1853 | |
194899bf | 1854 | assign = last_and_only_stmt (middle_bb); |
f4d3c071 | 1855 | /* If we did not find the proper negation assignment, then we cannot |
70512b93 | 1856 | optimize. */ |
1857 | if (assign == NULL) | |
1858 | return false; | |
48e1416a | 1859 | |
194899bf | 1860 | /* If we got here, then we have found the only executable statement |
1861 | in OTHER_BLOCK. If it is anything other than arg = -arg1 or | |
f4d3c071 | 1862 | arg1 = -arg0, then we cannot optimize. */ |
75a70cf9 | 1863 | if (gimple_code (assign) != GIMPLE_ASSIGN) |
194899bf | 1864 | return false; |
1865 | ||
75a70cf9 | 1866 | lhs = gimple_assign_lhs (assign); |
194899bf | 1867 | |
75a70cf9 | 1868 | if (gimple_assign_rhs_code (assign) != NEGATE_EXPR) |
194899bf | 1869 | return false; |
1870 | ||
75a70cf9 | 1871 | rhs = gimple_assign_rhs1 (assign); |
48e1416a | 1872 | |
194899bf | 1873 | /* The assignment has to be arg0 = -arg1 or arg1 = -arg0. */ |
1874 | if (!(lhs == arg0 && rhs == arg1) | |
1875 | && !(lhs == arg1 && rhs == arg0)) | |
1876 | return false; | |
70512b93 | 1877 | |
75a70cf9 | 1878 | cond = last_stmt (cond_bb); |
70512b93 | 1879 | result = PHI_RESULT (phi); |
1880 | ||
1881 | /* Only relationals comparing arg[01] against zero are interesting. */ | |
75a70cf9 | 1882 | cond_code = gimple_cond_code (cond); |
70512b93 | 1883 | if (cond_code != GT_EXPR && cond_code != GE_EXPR |
1884 | && cond_code != LT_EXPR && cond_code != LE_EXPR) | |
1885 | return false; | |
1886 | ||
dac49aa5 | 1887 | /* Make sure the conditional is arg[01] OP y. */ |
75a70cf9 | 1888 | if (gimple_cond_lhs (cond) != rhs) |
70512b93 | 1889 | return false; |
1890 | ||
75a70cf9 | 1891 | if (FLOAT_TYPE_P (TREE_TYPE (gimple_cond_rhs (cond))) |
1892 | ? real_zerop (gimple_cond_rhs (cond)) | |
1893 | : integer_zerop (gimple_cond_rhs (cond))) | |
70512b93 | 1894 | ; |
1895 | else | |
1896 | return false; | |
1897 | ||
1898 | /* We need to know which is the true edge and which is the false | |
1899 | edge so that we know if have abs or negative abs. */ | |
33784d89 | 1900 | extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge); |
70512b93 | 1901 | |
1902 | /* For GT_EXPR/GE_EXPR, if the true edge goes to OTHER_BLOCK, then we | |
1903 | will need to negate the result. Similarly for LT_EXPR/LE_EXPR if | |
1904 | the false edge goes to OTHER_BLOCK. */ | |
1905 | if (cond_code == GT_EXPR || cond_code == GE_EXPR) | |
1906 | e = true_edge; | |
1907 | else | |
1908 | e = false_edge; | |
20e5647c | 1909 | |
33784d89 | 1910 | if (e->dest == middle_bb) |
70512b93 | 1911 | negate = true; |
1912 | else | |
1913 | negate = false; | |
20e5647c | 1914 | |
57b2dea1 | 1915 | /* If the code negates only iff positive then make sure to not |
1916 | introduce undefined behavior when negating or computing the absolute. | |
1917 | ??? We could use range info if present to check for arg1 == INT_MIN. */ | |
1918 | if (negate | |
1919 | && (ANY_INTEGRAL_TYPE_P (TREE_TYPE (arg1)) | |
1920 | && ! TYPE_OVERFLOW_WRAPS (TREE_TYPE (arg1)))) | |
1921 | return false; | |
1922 | ||
33784d89 | 1923 | result = duplicate_ssa_name (result, NULL); |
20e5647c | 1924 | |
70512b93 | 1925 | if (negate) |
f9e245b2 | 1926 | lhs = make_ssa_name (TREE_TYPE (result)); |
70512b93 | 1927 | else |
1928 | lhs = result; | |
1929 | ||
dac49aa5 | 1930 | /* Build the modify expression with abs expression. */ |
e9cf809e | 1931 | new_stmt = gimple_build_assign (lhs, ABS_EXPR, rhs); |
70512b93 | 1932 | |
75a70cf9 | 1933 | gsi = gsi_last_bb (cond_bb); |
1934 | gsi_insert_before (&gsi, new_stmt, GSI_NEW_STMT); | |
70512b93 | 1935 | |
1936 | if (negate) | |
1937 | { | |
75a70cf9 | 1938 | /* Get the right GSI. We want to insert after the recently |
70512b93 | 1939 | added ABS_EXPR statement (which we know is the first statement |
1940 | in the block. */ | |
e9cf809e | 1941 | new_stmt = gimple_build_assign (result, NEGATE_EXPR, lhs); |
70512b93 | 1942 | |
75a70cf9 | 1943 | gsi_insert_after (&gsi, new_stmt, GSI_NEW_STMT); |
70512b93 | 1944 | } |
20e5647c | 1945 | |
a4844041 | 1946 | replace_phi_edge_with_variable (cond_bb, e1, phi, result); |
70512b93 | 1947 | |
1948 | /* Note that we optimized this PHI. */ | |
1949 | return true; | |
1950 | } | |
1951 | ||
e6d0e152 | 1952 | /* Auxiliary functions to determine the set of memory accesses which |
1953 | can't trap because they are preceded by accesses to the same memory | |
182cf5a9 | 1954 | portion. We do that for MEM_REFs, so we only need to track |
e6d0e152 | 1955 | the SSA_NAME of the pointer indirectly referenced. The algorithm |
1956 | simply is a walk over all instructions in dominator order. When | |
182cf5a9 | 1957 | we see an MEM_REF we determine if we've already seen a same |
e6d0e152 | 1958 | ref anywhere up to the root of the dominator tree. If we do the |
af4f74fa | 1959 | current access can't trap. If we don't see any dominating access |
e6d0e152 | 1960 | the current access might trap, but might also make later accesses |
af4f74fa | 1961 | non-trapping, so we remember it. We need to be careful with loads |
1962 | or stores, for instance a load might not trap, while a store would, | |
1963 | so if we see a dominating read access this doesn't mean that a later | |
1964 | write access would not trap. Hence we also need to differentiate the | |
1965 | type of access(es) seen. | |
1966 | ||
1967 | ??? We currently are very conservative and assume that a load might | |
1968 | trap even if a store doesn't (write-only memory). This probably is | |
1969 | overly conservative. */ | |
e6d0e152 | 1970 | |
182cf5a9 | 1971 | /* A hash-table of SSA_NAMEs, and in which basic block an MEM_REF |
e6d0e152 | 1972 | through it was seen, which would constitute a no-trap region for |
1973 | same accesses. */ | |
1974 | struct name_to_bb | |
1975 | { | |
963aee26 | 1976 | unsigned int ssa_name_ver; |
42540642 | 1977 | unsigned int phase; |
963aee26 | 1978 | bool store; |
1979 | HOST_WIDE_INT offset, size; | |
e6d0e152 | 1980 | basic_block bb; |
1981 | }; | |
1982 | ||
d9dd21a8 | 1983 | /* Hashtable helpers. */ |
1984 | ||
298e7f9a | 1985 | struct ssa_names_hasher : free_ptr_hash <name_to_bb> |
d9dd21a8 | 1986 | { |
9969c043 | 1987 | static inline hashval_t hash (const name_to_bb *); |
1988 | static inline bool equal (const name_to_bb *, const name_to_bb *); | |
d9dd21a8 | 1989 | }; |
e6d0e152 | 1990 | |
42540642 | 1991 | /* Used for quick clearing of the hash-table when we see calls. |
1992 | Hash entries with phase < nt_call_phase are invalid. */ | |
1993 | static unsigned int nt_call_phase; | |
1994 | ||
963aee26 | 1995 | /* The hash function. */ |
d9dd21a8 | 1996 | |
1997 | inline hashval_t | |
9969c043 | 1998 | ssa_names_hasher::hash (const name_to_bb *n) |
e6d0e152 | 1999 | { |
963aee26 | 2000 | return n->ssa_name_ver ^ (((hashval_t) n->store) << 31) |
2001 | ^ (n->offset << 6) ^ (n->size << 3); | |
e6d0e152 | 2002 | } |
2003 | ||
963aee26 | 2004 | /* The equality function of *P1 and *P2. */ |
e6d0e152 | 2005 | |
d9dd21a8 | 2006 | inline bool |
9969c043 | 2007 | ssa_names_hasher::equal (const name_to_bb *n1, const name_to_bb *n2) |
d9dd21a8 | 2008 | { |
963aee26 | 2009 | return n1->ssa_name_ver == n2->ssa_name_ver |
2010 | && n1->store == n2->store | |
2011 | && n1->offset == n2->offset | |
2012 | && n1->size == n2->size; | |
e6d0e152 | 2013 | } |
2014 | ||
c1f445d2 | 2015 | class nontrapping_dom_walker : public dom_walker |
2016 | { | |
2017 | public: | |
431205b7 | 2018 | nontrapping_dom_walker (cdi_direction direction, hash_set<tree> *ps) |
c1f445d2 | 2019 | : dom_walker (direction), m_nontrapping (ps), m_seen_ssa_names (128) {} |
2020 | ||
96752458 | 2021 | virtual edge before_dom_children (basic_block); |
c1f445d2 | 2022 | virtual void after_dom_children (basic_block); |
2023 | ||
2024 | private: | |
2025 | ||
2026 | /* We see the expression EXP in basic block BB. If it's an interesting | |
2027 | expression (an MEM_REF through an SSA_NAME) possibly insert the | |
2028 | expression into the set NONTRAP or the hash table of seen expressions. | |
2029 | STORE is true if this expression is on the LHS, otherwise it's on | |
2030 | the RHS. */ | |
2031 | void add_or_mark_expr (basic_block, tree, bool); | |
2032 | ||
431205b7 | 2033 | hash_set<tree> *m_nontrapping; |
c1f445d2 | 2034 | |
2035 | /* The hash table for remembering what we've seen. */ | |
2036 | hash_table<ssa_names_hasher> m_seen_ssa_names; | |
2037 | }; | |
2038 | ||
2039 | /* Called by walk_dominator_tree, when entering the block BB. */ | |
96752458 | 2040 | edge |
c1f445d2 | 2041 | nontrapping_dom_walker::before_dom_children (basic_block bb) |
2042 | { | |
2043 | edge e; | |
2044 | edge_iterator ei; | |
2045 | gimple_stmt_iterator gsi; | |
2046 | ||
2047 | /* If we haven't seen all our predecessors, clear the hash-table. */ | |
2048 | FOR_EACH_EDGE (e, ei, bb->preds) | |
2049 | if ((((size_t)e->src->aux) & 2) == 0) | |
2050 | { | |
2051 | nt_call_phase++; | |
2052 | break; | |
2053 | } | |
2054 | ||
2055 | /* Mark this BB as being on the path to dominator root and as visited. */ | |
2056 | bb->aux = (void*)(1 | 2); | |
2057 | ||
2058 | /* And walk the statements in order. */ | |
2059 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
2060 | { | |
42acab1c | 2061 | gimple *stmt = gsi_stmt (gsi); |
c1f445d2 | 2062 | |
05a63389 | 2063 | if ((gimple_code (stmt) == GIMPLE_ASM && gimple_vdef (stmt)) |
2064 | || (is_gimple_call (stmt) | |
2065 | && (!nonfreeing_call_p (stmt) || !nonbarrier_call_p (stmt)))) | |
c1f445d2 | 2066 | nt_call_phase++; |
2067 | else if (gimple_assign_single_p (stmt) && !gimple_has_volatile_ops (stmt)) | |
2068 | { | |
2069 | add_or_mark_expr (bb, gimple_assign_lhs (stmt), true); | |
2070 | add_or_mark_expr (bb, gimple_assign_rhs1 (stmt), false); | |
2071 | } | |
2072 | } | |
96752458 | 2073 | return NULL; |
c1f445d2 | 2074 | } |
2075 | ||
2076 | /* Called by walk_dominator_tree, when basic block BB is exited. */ | |
2077 | void | |
2078 | nontrapping_dom_walker::after_dom_children (basic_block bb) | |
2079 | { | |
2080 | /* This BB isn't on the path to dominator root anymore. */ | |
2081 | bb->aux = (void*)2; | |
2082 | } | |
d9dd21a8 | 2083 | |
f0b5f617 | 2084 | /* We see the expression EXP in basic block BB. If it's an interesting |
182cf5a9 | 2085 | expression (an MEM_REF through an SSA_NAME) possibly insert the |
af4f74fa | 2086 | expression into the set NONTRAP or the hash table of seen expressions. |
2087 | STORE is true if this expression is on the LHS, otherwise it's on | |
2088 | the RHS. */ | |
c1f445d2 | 2089 | void |
2090 | nontrapping_dom_walker::add_or_mark_expr (basic_block bb, tree exp, bool store) | |
e6d0e152 | 2091 | { |
963aee26 | 2092 | HOST_WIDE_INT size; |
2093 | ||
182cf5a9 | 2094 | if (TREE_CODE (exp) == MEM_REF |
963aee26 | 2095 | && TREE_CODE (TREE_OPERAND (exp, 0)) == SSA_NAME |
e913b5cd | 2096 | && tree_fits_shwi_p (TREE_OPERAND (exp, 1)) |
963aee26 | 2097 | && (size = int_size_in_bytes (TREE_TYPE (exp))) > 0) |
e6d0e152 | 2098 | { |
2099 | tree name = TREE_OPERAND (exp, 0); | |
2100 | struct name_to_bb map; | |
d9dd21a8 | 2101 | name_to_bb **slot; |
af4f74fa | 2102 | struct name_to_bb *n2bb; |
e6d0e152 | 2103 | basic_block found_bb = 0; |
2104 | ||
182cf5a9 | 2105 | /* Try to find the last seen MEM_REF through the same |
e6d0e152 | 2106 | SSA_NAME, which can trap. */ |
963aee26 | 2107 | map.ssa_name_ver = SSA_NAME_VERSION (name); |
42540642 | 2108 | map.phase = 0; |
e6d0e152 | 2109 | map.bb = 0; |
af4f74fa | 2110 | map.store = store; |
e913b5cd | 2111 | map.offset = tree_to_shwi (TREE_OPERAND (exp, 1)); |
963aee26 | 2112 | map.size = size; |
2113 | ||
c1f445d2 | 2114 | slot = m_seen_ssa_names.find_slot (&map, INSERT); |
d9dd21a8 | 2115 | n2bb = *slot; |
42540642 | 2116 | if (n2bb && n2bb->phase >= nt_call_phase) |
af4f74fa | 2117 | found_bb = n2bb->bb; |
e6d0e152 | 2118 | |
182cf5a9 | 2119 | /* If we've found a trapping MEM_REF, _and_ it dominates EXP |
e6d0e152 | 2120 | (it's in a basic block on the path from us to the dominator root) |
2121 | then we can't trap. */ | |
42540642 | 2122 | if (found_bb && (((size_t)found_bb->aux) & 1) == 1) |
e6d0e152 | 2123 | { |
431205b7 | 2124 | m_nontrapping->add (exp); |
e6d0e152 | 2125 | } |
2126 | else | |
2127 | { | |
2128 | /* EXP might trap, so insert it into the hash table. */ | |
af4f74fa | 2129 | if (n2bb) |
e6d0e152 | 2130 | { |
42540642 | 2131 | n2bb->phase = nt_call_phase; |
af4f74fa | 2132 | n2bb->bb = bb; |
e6d0e152 | 2133 | } |
2134 | else | |
2135 | { | |
af4f74fa | 2136 | n2bb = XNEW (struct name_to_bb); |
963aee26 | 2137 | n2bb->ssa_name_ver = SSA_NAME_VERSION (name); |
42540642 | 2138 | n2bb->phase = nt_call_phase; |
af4f74fa | 2139 | n2bb->bb = bb; |
2140 | n2bb->store = store; | |
963aee26 | 2141 | n2bb->offset = map.offset; |
2142 | n2bb->size = size; | |
af4f74fa | 2143 | *slot = n2bb; |
e6d0e152 | 2144 | } |
2145 | } | |
2146 | } | |
2147 | } | |
2148 | ||
e6d0e152 | 2149 | /* This is the entry point of gathering non trapping memory accesses. |
2150 | It will do a dominator walk over the whole function, and it will | |
2151 | make use of the bb->aux pointers. It returns a set of trees | |
182cf5a9 | 2152 | (the MEM_REFs itself) which can't trap. */ |
431205b7 | 2153 | static hash_set<tree> * |
e6d0e152 | 2154 | get_non_trapping (void) |
2155 | { | |
42540642 | 2156 | nt_call_phase = 0; |
431205b7 | 2157 | hash_set<tree> *nontrap = new hash_set<tree>; |
e6d0e152 | 2158 | /* We're going to do a dominator walk, so ensure that we have |
2159 | dominance information. */ | |
2160 | calculate_dominance_info (CDI_DOMINATORS); | |
2161 | ||
54c91640 | 2162 | nontrapping_dom_walker (CDI_DOMINATORS, nontrap) |
2163 | .walk (cfun->cfg->x_entry_block_ptr); | |
2164 | ||
42540642 | 2165 | clear_aux_for_blocks (); |
e6d0e152 | 2166 | return nontrap; |
2167 | } | |
2168 | ||
2169 | /* Do the main work of conditional store replacement. We already know | |
2170 | that the recognized pattern looks like so: | |
2171 | ||
2172 | split: | |
2173 | if (cond) goto MIDDLE_BB; else goto JOIN_BB (edge E1) | |
2174 | MIDDLE_BB: | |
2175 | something | |
2176 | fallthrough (edge E0) | |
2177 | JOIN_BB: | |
2178 | some more | |
2179 | ||
2180 | We check that MIDDLE_BB contains only one store, that that store | |
2181 | doesn't trap (not via NOTRAP, but via checking if an access to the same | |
2182 | memory location dominates us) and that the store has a "simple" RHS. */ | |
2183 | ||
2184 | static bool | |
2185 | cond_store_replacement (basic_block middle_bb, basic_block join_bb, | |
431205b7 | 2186 | edge e0, edge e1, hash_set<tree> *nontrap) |
e6d0e152 | 2187 | { |
42acab1c | 2188 | gimple *assign = last_and_only_stmt (middle_bb); |
03d37e4e | 2189 | tree lhs, rhs, name, name2; |
1a91d914 | 2190 | gphi *newphi; |
2191 | gassign *new_stmt; | |
75a70cf9 | 2192 | gimple_stmt_iterator gsi; |
be1e7283 | 2193 | location_t locus; |
e6d0e152 | 2194 | |
2195 | /* Check if middle_bb contains of only one store. */ | |
2196 | if (!assign | |
6cc085b6 | 2197 | || !gimple_assign_single_p (assign) |
2198 | || gimple_has_volatile_ops (assign)) | |
e6d0e152 | 2199 | return false; |
2200 | ||
efbcb6de | 2201 | locus = gimple_location (assign); |
75a70cf9 | 2202 | lhs = gimple_assign_lhs (assign); |
2203 | rhs = gimple_assign_rhs1 (assign); | |
182cf5a9 | 2204 | if (TREE_CODE (lhs) != MEM_REF |
91cf53d5 | 2205 | || TREE_CODE (TREE_OPERAND (lhs, 0)) != SSA_NAME |
3211fa0a | 2206 | || !is_gimple_reg_type (TREE_TYPE (lhs))) |
e6d0e152 | 2207 | return false; |
91cf53d5 | 2208 | |
e6d0e152 | 2209 | /* Prove that we can move the store down. We could also check |
2210 | TREE_THIS_NOTRAP here, but in that case we also could move stores, | |
2211 | whose value is not available readily, which we want to avoid. */ | |
431205b7 | 2212 | if (!nontrap->contains (lhs)) |
e6d0e152 | 2213 | return false; |
2214 | ||
2215 | /* Now we've checked the constraints, so do the transformation: | |
2216 | 1) Remove the single store. */ | |
75a70cf9 | 2217 | gsi = gsi_for_stmt (assign); |
3211fa0a | 2218 | unlink_stmt_vdef (assign); |
75a70cf9 | 2219 | gsi_remove (&gsi, true); |
91cf53d5 | 2220 | release_defs (assign); |
e6d0e152 | 2221 | |
20496f0e | 2222 | /* Make both store and load use alias-set zero as we have to |
2223 | deal with the case of the store being a conditional change | |
2224 | of the dynamic type. */ | |
2225 | lhs = unshare_expr (lhs); | |
2226 | tree *basep = &lhs; | |
2227 | while (handled_component_p (*basep)) | |
2228 | basep = &TREE_OPERAND (*basep, 0); | |
2229 | if (TREE_CODE (*basep) == MEM_REF | |
2230 | || TREE_CODE (*basep) == TARGET_MEM_REF) | |
2231 | TREE_OPERAND (*basep, 1) | |
2232 | = fold_convert (ptr_type_node, TREE_OPERAND (*basep, 1)); | |
2233 | else | |
2234 | *basep = build2 (MEM_REF, TREE_TYPE (*basep), | |
2235 | build_fold_addr_expr (*basep), | |
2236 | build_zero_cst (ptr_type_node)); | |
2237 | ||
03d37e4e | 2238 | /* 2) Insert a load from the memory of the store to the temporary |
e6d0e152 | 2239 | on the edge which did not contain the store. */ |
03d37e4e | 2240 | name = make_temp_ssa_name (TREE_TYPE (lhs), NULL, "cstore"); |
2241 | new_stmt = gimple_build_assign (name, lhs); | |
efbcb6de | 2242 | gimple_set_location (new_stmt, locus); |
75a70cf9 | 2243 | gsi_insert_on_edge (e1, new_stmt); |
e6d0e152 | 2244 | |
03d37e4e | 2245 | /* 3) Create a PHI node at the join block, with one argument |
e6d0e152 | 2246 | holding the old RHS, and the other holding the temporary |
2247 | where we stored the old memory contents. */ | |
03d37e4e | 2248 | name2 = make_temp_ssa_name (TREE_TYPE (lhs), NULL, "cstore"); |
2249 | newphi = create_phi_node (name2, join_bb); | |
60d535d2 | 2250 | add_phi_arg (newphi, rhs, e0, locus); |
2251 | add_phi_arg (newphi, name, e1, locus); | |
e6d0e152 | 2252 | |
2253 | lhs = unshare_expr (lhs); | |
75a70cf9 | 2254 | new_stmt = gimple_build_assign (lhs, PHI_RESULT (newphi)); |
e6d0e152 | 2255 | |
03d37e4e | 2256 | /* 4) Insert that PHI node. */ |
75a70cf9 | 2257 | gsi = gsi_after_labels (join_bb); |
2258 | if (gsi_end_p (gsi)) | |
e6d0e152 | 2259 | { |
75a70cf9 | 2260 | gsi = gsi_last_bb (join_bb); |
2261 | gsi_insert_after (&gsi, new_stmt, GSI_NEW_STMT); | |
e6d0e152 | 2262 | } |
2263 | else | |
75a70cf9 | 2264 | gsi_insert_before (&gsi, new_stmt, GSI_NEW_STMT); |
e6d0e152 | 2265 | |
2266 | return true; | |
2267 | } | |
4ee9c684 | 2268 | |
ec611e12 | 2269 | /* Do the main work of conditional store replacement. */ |
91cf53d5 | 2270 | |
2271 | static bool | |
ec611e12 | 2272 | cond_if_else_store_replacement_1 (basic_block then_bb, basic_block else_bb, |
42acab1c | 2273 | basic_block join_bb, gimple *then_assign, |
2274 | gimple *else_assign) | |
91cf53d5 | 2275 | { |
03d37e4e | 2276 | tree lhs_base, lhs, then_rhs, else_rhs, name; |
be1e7283 | 2277 | location_t then_locus, else_locus; |
91cf53d5 | 2278 | gimple_stmt_iterator gsi; |
1a91d914 | 2279 | gphi *newphi; |
2280 | gassign *new_stmt; | |
91cf53d5 | 2281 | |
91cf53d5 | 2282 | if (then_assign == NULL |
2283 | || !gimple_assign_single_p (then_assign) | |
3c25489e | 2284 | || gimple_clobber_p (then_assign) |
6cc085b6 | 2285 | || gimple_has_volatile_ops (then_assign) |
91cf53d5 | 2286 | || else_assign == NULL |
3c25489e | 2287 | || !gimple_assign_single_p (else_assign) |
6cc085b6 | 2288 | || gimple_clobber_p (else_assign) |
2289 | || gimple_has_volatile_ops (else_assign)) | |
91cf53d5 | 2290 | return false; |
2291 | ||
2292 | lhs = gimple_assign_lhs (then_assign); | |
2293 | if (!is_gimple_reg_type (TREE_TYPE (lhs)) | |
2294 | || !operand_equal_p (lhs, gimple_assign_lhs (else_assign), 0)) | |
2295 | return false; | |
2296 | ||
2297 | lhs_base = get_base_address (lhs); | |
2298 | if (lhs_base == NULL_TREE | |
2299 | || (!DECL_P (lhs_base) && TREE_CODE (lhs_base) != MEM_REF)) | |
2300 | return false; | |
2301 | ||
2302 | then_rhs = gimple_assign_rhs1 (then_assign); | |
2303 | else_rhs = gimple_assign_rhs1 (else_assign); | |
2304 | then_locus = gimple_location (then_assign); | |
2305 | else_locus = gimple_location (else_assign); | |
2306 | ||
2307 | /* Now we've checked the constraints, so do the transformation: | |
2308 | 1) Remove the stores. */ | |
2309 | gsi = gsi_for_stmt (then_assign); | |
2310 | unlink_stmt_vdef (then_assign); | |
2311 | gsi_remove (&gsi, true); | |
2312 | release_defs (then_assign); | |
2313 | ||
2314 | gsi = gsi_for_stmt (else_assign); | |
2315 | unlink_stmt_vdef (else_assign); | |
2316 | gsi_remove (&gsi, true); | |
2317 | release_defs (else_assign); | |
2318 | ||
03d37e4e | 2319 | /* 2) Create a PHI node at the join block, with one argument |
91cf53d5 | 2320 | holding the old RHS, and the other holding the temporary |
2321 | where we stored the old memory contents. */ | |
03d37e4e | 2322 | name = make_temp_ssa_name (TREE_TYPE (lhs), NULL, "cstore"); |
2323 | newphi = create_phi_node (name, join_bb); | |
60d535d2 | 2324 | add_phi_arg (newphi, then_rhs, EDGE_SUCC (then_bb, 0), then_locus); |
2325 | add_phi_arg (newphi, else_rhs, EDGE_SUCC (else_bb, 0), else_locus); | |
91cf53d5 | 2326 | |
2327 | new_stmt = gimple_build_assign (lhs, PHI_RESULT (newphi)); | |
2328 | ||
03d37e4e | 2329 | /* 3) Insert that PHI node. */ |
91cf53d5 | 2330 | gsi = gsi_after_labels (join_bb); |
2331 | if (gsi_end_p (gsi)) | |
2332 | { | |
2333 | gsi = gsi_last_bb (join_bb); | |
2334 | gsi_insert_after (&gsi, new_stmt, GSI_NEW_STMT); | |
2335 | } | |
2336 | else | |
2337 | gsi_insert_before (&gsi, new_stmt, GSI_NEW_STMT); | |
2338 | ||
2339 | return true; | |
2340 | } | |
2341 | ||
33ac517c | 2342 | /* Return the single store in BB with VDEF or NULL if there are |
2343 | other stores in the BB or loads following the store. */ | |
2344 | ||
2345 | static gimple * | |
2346 | single_trailing_store_in_bb (basic_block bb, tree vdef) | |
2347 | { | |
2348 | if (SSA_NAME_IS_DEFAULT_DEF (vdef)) | |
2349 | return NULL; | |
2350 | gimple *store = SSA_NAME_DEF_STMT (vdef); | |
2351 | if (gimple_bb (store) != bb | |
2352 | || gimple_code (store) == GIMPLE_PHI) | |
2353 | return NULL; | |
2354 | ||
2355 | /* Verify there is no other store in this BB. */ | |
2356 | if (!SSA_NAME_IS_DEFAULT_DEF (gimple_vuse (store)) | |
2357 | && gimple_bb (SSA_NAME_DEF_STMT (gimple_vuse (store))) == bb | |
2358 | && gimple_code (SSA_NAME_DEF_STMT (gimple_vuse (store))) != GIMPLE_PHI) | |
2359 | return NULL; | |
2360 | ||
2361 | /* Verify there is no load or store after the store. */ | |
2362 | use_operand_p use_p; | |
2363 | imm_use_iterator imm_iter; | |
2364 | FOR_EACH_IMM_USE_FAST (use_p, imm_iter, gimple_vdef (store)) | |
2365 | if (USE_STMT (use_p) != store | |
2366 | && gimple_bb (USE_STMT (use_p)) == bb) | |
2367 | return NULL; | |
2368 | ||
2369 | return store; | |
2370 | } | |
2371 | ||
ec611e12 | 2372 | /* Conditional store replacement. We already know |
2373 | that the recognized pattern looks like so: | |
2374 | ||
2375 | split: | |
2376 | if (cond) goto THEN_BB; else goto ELSE_BB (edge E1) | |
2377 | THEN_BB: | |
2378 | ... | |
2379 | X = Y; | |
2380 | ... | |
2381 | goto JOIN_BB; | |
2382 | ELSE_BB: | |
2383 | ... | |
2384 | X = Z; | |
2385 | ... | |
2386 | fallthrough (edge E0) | |
2387 | JOIN_BB: | |
2388 | some more | |
2389 | ||
2390 | We check that it is safe to sink the store to JOIN_BB by verifying that | |
2391 | there are no read-after-write or write-after-write dependencies in | |
2392 | THEN_BB and ELSE_BB. */ | |
2393 | ||
2394 | static bool | |
2395 | cond_if_else_store_replacement (basic_block then_bb, basic_block else_bb, | |
2396 | basic_block join_bb) | |
2397 | { | |
f1f41a6c | 2398 | vec<data_reference_p> then_datarefs, else_datarefs; |
2399 | vec<ddr_p> then_ddrs, else_ddrs; | |
42acab1c | 2400 | gimple *then_store, *else_store; |
ec611e12 | 2401 | bool found, ok = false, res; |
2402 | struct data_dependence_relation *ddr; | |
2403 | data_reference_p then_dr, else_dr; | |
2404 | int i, j; | |
2405 | tree then_lhs, else_lhs; | |
ec611e12 | 2406 | basic_block blocks[3]; |
2407 | ||
33ac517c | 2408 | /* Handle the case with single store in THEN_BB and ELSE_BB. That is |
2409 | cheap enough to always handle as it allows us to elide dependence | |
2410 | checking. */ | |
2411 | gphi *vphi = NULL; | |
2412 | for (gphi_iterator si = gsi_start_phis (join_bb); !gsi_end_p (si); | |
2413 | gsi_next (&si)) | |
2414 | if (virtual_operand_p (gimple_phi_result (si.phi ()))) | |
2415 | { | |
2416 | vphi = si.phi (); | |
2417 | break; | |
2418 | } | |
2419 | if (!vphi) | |
ec611e12 | 2420 | return false; |
33ac517c | 2421 | tree then_vdef = PHI_ARG_DEF_FROM_EDGE (vphi, single_succ_edge (then_bb)); |
2422 | tree else_vdef = PHI_ARG_DEF_FROM_EDGE (vphi, single_succ_edge (else_bb)); | |
2423 | gimple *then_assign = single_trailing_store_in_bb (then_bb, then_vdef); | |
2424 | if (then_assign) | |
2425 | { | |
2426 | gimple *else_assign = single_trailing_store_in_bb (else_bb, else_vdef); | |
2427 | if (else_assign) | |
2428 | return cond_if_else_store_replacement_1 (then_bb, else_bb, join_bb, | |
2429 | then_assign, else_assign); | |
2430 | } | |
ec611e12 | 2431 | |
33ac517c | 2432 | if (MAX_STORES_TO_SINK == 0) |
2433 | return false; | |
ec611e12 | 2434 | |
2435 | /* Find data references. */ | |
f1f41a6c | 2436 | then_datarefs.create (1); |
2437 | else_datarefs.create (1); | |
ec611e12 | 2438 | if ((find_data_references_in_bb (NULL, then_bb, &then_datarefs) |
2439 | == chrec_dont_know) | |
f1f41a6c | 2440 | || !then_datarefs.length () |
ec611e12 | 2441 | || (find_data_references_in_bb (NULL, else_bb, &else_datarefs) |
c71d3c24 | 2442 | == chrec_dont_know) |
f1f41a6c | 2443 | || !else_datarefs.length ()) |
ec611e12 | 2444 | { |
2445 | free_data_refs (then_datarefs); | |
2446 | free_data_refs (else_datarefs); | |
2447 | return false; | |
2448 | } | |
2449 | ||
2450 | /* Find pairs of stores with equal LHS. */ | |
42acab1c | 2451 | auto_vec<gimple *, 1> then_stores, else_stores; |
f1f41a6c | 2452 | FOR_EACH_VEC_ELT (then_datarefs, i, then_dr) |
ec611e12 | 2453 | { |
2454 | if (DR_IS_READ (then_dr)) | |
2455 | continue; | |
2456 | ||
2457 | then_store = DR_STMT (then_dr); | |
728dcc71 | 2458 | then_lhs = gimple_get_lhs (then_store); |
c71d3c24 | 2459 | if (then_lhs == NULL_TREE) |
2460 | continue; | |
ec611e12 | 2461 | found = false; |
2462 | ||
f1f41a6c | 2463 | FOR_EACH_VEC_ELT (else_datarefs, j, else_dr) |
ec611e12 | 2464 | { |
2465 | if (DR_IS_READ (else_dr)) | |
2466 | continue; | |
2467 | ||
2468 | else_store = DR_STMT (else_dr); | |
728dcc71 | 2469 | else_lhs = gimple_get_lhs (else_store); |
c71d3c24 | 2470 | if (else_lhs == NULL_TREE) |
2471 | continue; | |
ec611e12 | 2472 | |
2473 | if (operand_equal_p (then_lhs, else_lhs, 0)) | |
2474 | { | |
2475 | found = true; | |
2476 | break; | |
2477 | } | |
2478 | } | |
2479 | ||
2480 | if (!found) | |
2481 | continue; | |
2482 | ||
f1f41a6c | 2483 | then_stores.safe_push (then_store); |
2484 | else_stores.safe_push (else_store); | |
ec611e12 | 2485 | } |
2486 | ||
2487 | /* No pairs of stores found. */ | |
f1f41a6c | 2488 | if (!then_stores.length () |
2489 | || then_stores.length () > (unsigned) MAX_STORES_TO_SINK) | |
ec611e12 | 2490 | { |
2491 | free_data_refs (then_datarefs); | |
2492 | free_data_refs (else_datarefs); | |
ec611e12 | 2493 | return false; |
2494 | } | |
2495 | ||
2496 | /* Compute and check data dependencies in both basic blocks. */ | |
f1f41a6c | 2497 | then_ddrs.create (1); |
2498 | else_ddrs.create (1); | |
2499 | if (!compute_all_dependences (then_datarefs, &then_ddrs, | |
1e094109 | 2500 | vNULL, false) |
f1f41a6c | 2501 | || !compute_all_dependences (else_datarefs, &else_ddrs, |
1e094109 | 2502 | vNULL, false)) |
8b3fb720 | 2503 | { |
2504 | free_dependence_relations (then_ddrs); | |
2505 | free_dependence_relations (else_ddrs); | |
2506 | free_data_refs (then_datarefs); | |
2507 | free_data_refs (else_datarefs); | |
8b3fb720 | 2508 | return false; |
2509 | } | |
ec611e12 | 2510 | blocks[0] = then_bb; |
2511 | blocks[1] = else_bb; | |
2512 | blocks[2] = join_bb; | |
2513 | renumber_gimple_stmt_uids_in_blocks (blocks, 3); | |
2514 | ||
2515 | /* Check that there are no read-after-write or write-after-write dependencies | |
2516 | in THEN_BB. */ | |
f1f41a6c | 2517 | FOR_EACH_VEC_ELT (then_ddrs, i, ddr) |
ec611e12 | 2518 | { |
2519 | struct data_reference *dra = DDR_A (ddr); | |
2520 | struct data_reference *drb = DDR_B (ddr); | |
2521 | ||
2522 | if (DDR_ARE_DEPENDENT (ddr) != chrec_known | |
2523 | && ((DR_IS_READ (dra) && DR_IS_WRITE (drb) | |
2524 | && gimple_uid (DR_STMT (dra)) > gimple_uid (DR_STMT (drb))) | |
2525 | || (DR_IS_READ (drb) && DR_IS_WRITE (dra) | |
2526 | && gimple_uid (DR_STMT (drb)) > gimple_uid (DR_STMT (dra))) | |
2527 | || (DR_IS_WRITE (dra) && DR_IS_WRITE (drb)))) | |
2528 | { | |
2529 | free_dependence_relations (then_ddrs); | |
2530 | free_dependence_relations (else_ddrs); | |
2473bfb7 | 2531 | free_data_refs (then_datarefs); |
2532 | free_data_refs (else_datarefs); | |
ec611e12 | 2533 | return false; |
2534 | } | |
2535 | } | |
2536 | ||
2537 | /* Check that there are no read-after-write or write-after-write dependencies | |
2538 | in ELSE_BB. */ | |
f1f41a6c | 2539 | FOR_EACH_VEC_ELT (else_ddrs, i, ddr) |
ec611e12 | 2540 | { |
2541 | struct data_reference *dra = DDR_A (ddr); | |
2542 | struct data_reference *drb = DDR_B (ddr); | |
2543 | ||
2544 | if (DDR_ARE_DEPENDENT (ddr) != chrec_known | |
2545 | && ((DR_IS_READ (dra) && DR_IS_WRITE (drb) | |
2546 | && gimple_uid (DR_STMT (dra)) > gimple_uid (DR_STMT (drb))) | |
2547 | || (DR_IS_READ (drb) && DR_IS_WRITE (dra) | |
2548 | && gimple_uid (DR_STMT (drb)) > gimple_uid (DR_STMT (dra))) | |
2549 | || (DR_IS_WRITE (dra) && DR_IS_WRITE (drb)))) | |
2550 | { | |
2551 | free_dependence_relations (then_ddrs); | |
2552 | free_dependence_relations (else_ddrs); | |
2473bfb7 | 2553 | free_data_refs (then_datarefs); |
2554 | free_data_refs (else_datarefs); | |
ec611e12 | 2555 | return false; |
2556 | } | |
2557 | } | |
2558 | ||
2559 | /* Sink stores with same LHS. */ | |
f1f41a6c | 2560 | FOR_EACH_VEC_ELT (then_stores, i, then_store) |
ec611e12 | 2561 | { |
f1f41a6c | 2562 | else_store = else_stores[i]; |
ec611e12 | 2563 | res = cond_if_else_store_replacement_1 (then_bb, else_bb, join_bb, |
2564 | then_store, else_store); | |
2565 | ok = ok || res; | |
2566 | } | |
2567 | ||
2568 | free_dependence_relations (then_ddrs); | |
2569 | free_dependence_relations (else_ddrs); | |
2473bfb7 | 2570 | free_data_refs (then_datarefs); |
2571 | free_data_refs (else_datarefs); | |
ec611e12 | 2572 | |
2573 | return ok; | |
2574 | } | |
2575 | ||
239e9670 | 2576 | /* Return TRUE if STMT has a VUSE whose corresponding VDEF is in BB. */ |
2577 | ||
2578 | static bool | |
42acab1c | 2579 | local_mem_dependence (gimple *stmt, basic_block bb) |
239e9670 | 2580 | { |
2581 | tree vuse = gimple_vuse (stmt); | |
42acab1c | 2582 | gimple *def; |
239e9670 | 2583 | |
2584 | if (!vuse) | |
2585 | return false; | |
2586 | ||
2587 | def = SSA_NAME_DEF_STMT (vuse); | |
2588 | return (def && gimple_bb (def) == bb); | |
2589 | } | |
2590 | ||
2591 | /* Given a "diamond" control-flow pattern where BB0 tests a condition, | |
2592 | BB1 and BB2 are "then" and "else" blocks dependent on this test, | |
f32420fb | 2593 | and BB3 rejoins control flow following BB1 and BB2, look for |
239e9670 | 2594 | opportunities to hoist loads as follows. If BB3 contains a PHI of |
2595 | two loads, one each occurring in BB1 and BB2, and the loads are | |
2596 | provably of adjacent fields in the same structure, then move both | |
2597 | loads into BB0. Of course this can only be done if there are no | |
2598 | dependencies preventing such motion. | |
2599 | ||
2600 | One of the hoisted loads will always be speculative, so the | |
2601 | transformation is currently conservative: | |
2602 | ||
2603 | - The fields must be strictly adjacent. | |
2604 | - The two fields must occupy a single memory block that is | |
2605 | guaranteed to not cross a page boundary. | |
2606 | ||
2607 | The last is difficult to prove, as such memory blocks should be | |
2608 | aligned on the minimum of the stack alignment boundary and the | |
2609 | alignment guaranteed by heap allocation interfaces. Thus we rely | |
2610 | on a parameter for the alignment value. | |
2611 | ||
2612 | Provided a good value is used for the last case, the first | |
2613 | restriction could possibly be relaxed. */ | |
2614 | ||
2615 | static void | |
2616 | hoist_adjacent_loads (basic_block bb0, basic_block bb1, | |
2617 | basic_block bb2, basic_block bb3) | |
2618 | { | |
2619 | int param_align = PARAM_VALUE (PARAM_L1_CACHE_LINE_SIZE); | |
2620 | unsigned param_align_bits = (unsigned) (param_align * BITS_PER_UNIT); | |
1a91d914 | 2621 | gphi_iterator gsi; |
239e9670 | 2622 | |
2623 | /* Walk the phis in bb3 looking for an opportunity. We are looking | |
2624 | for phis of two SSA names, one each of which is defined in bb1 and | |
2625 | bb2. */ | |
2626 | for (gsi = gsi_start_phis (bb3); !gsi_end_p (gsi); gsi_next (&gsi)) | |
2627 | { | |
1a91d914 | 2628 | gphi *phi_stmt = gsi.phi (); |
42acab1c | 2629 | gimple *def1, *def2; |
dfcf26a5 | 2630 | tree arg1, arg2, ref1, ref2, field1, field2; |
239e9670 | 2631 | tree tree_offset1, tree_offset2, tree_size2, next; |
2632 | int offset1, offset2, size2; | |
2633 | unsigned align1; | |
2634 | gimple_stmt_iterator gsi2; | |
2635 | basic_block bb_for_def1, bb_for_def2; | |
2636 | ||
7c782c9b | 2637 | if (gimple_phi_num_args (phi_stmt) != 2 |
2638 | || virtual_operand_p (gimple_phi_result (phi_stmt))) | |
239e9670 | 2639 | continue; |
2640 | ||
2641 | arg1 = gimple_phi_arg_def (phi_stmt, 0); | |
2642 | arg2 = gimple_phi_arg_def (phi_stmt, 1); | |
f32420fb | 2643 | |
239e9670 | 2644 | if (TREE_CODE (arg1) != SSA_NAME |
2645 | || TREE_CODE (arg2) != SSA_NAME | |
2646 | || SSA_NAME_IS_DEFAULT_DEF (arg1) | |
7c782c9b | 2647 | || SSA_NAME_IS_DEFAULT_DEF (arg2)) |
239e9670 | 2648 | continue; |
2649 | ||
2650 | def1 = SSA_NAME_DEF_STMT (arg1); | |
2651 | def2 = SSA_NAME_DEF_STMT (arg2); | |
2652 | ||
2653 | if ((gimple_bb (def1) != bb1 || gimple_bb (def2) != bb2) | |
2654 | && (gimple_bb (def2) != bb1 || gimple_bb (def1) != bb2)) | |
2655 | continue; | |
2656 | ||
2657 | /* Check the mode of the arguments to be sure a conditional move | |
2658 | can be generated for it. */ | |
935611bc | 2659 | if (optab_handler (movcc_optab, TYPE_MODE (TREE_TYPE (arg1))) |
2660 | == CODE_FOR_nothing) | |
239e9670 | 2661 | continue; |
2662 | ||
2663 | /* Both statements must be assignments whose RHS is a COMPONENT_REF. */ | |
2664 | if (!gimple_assign_single_p (def1) | |
6cc085b6 | 2665 | || !gimple_assign_single_p (def2) |
2666 | || gimple_has_volatile_ops (def1) | |
2667 | || gimple_has_volatile_ops (def2)) | |
239e9670 | 2668 | continue; |
2669 | ||
2670 | ref1 = gimple_assign_rhs1 (def1); | |
2671 | ref2 = gimple_assign_rhs1 (def2); | |
2672 | ||
2673 | if (TREE_CODE (ref1) != COMPONENT_REF | |
2674 | || TREE_CODE (ref2) != COMPONENT_REF) | |
2675 | continue; | |
2676 | ||
2677 | /* The zeroth operand of the two component references must be | |
2678 | identical. It is not sufficient to compare get_base_address of | |
2679 | the two references, because this could allow for different | |
2680 | elements of the same array in the two trees. It is not safe to | |
2681 | assume that the existence of one array element implies the | |
2682 | existence of a different one. */ | |
2683 | if (!operand_equal_p (TREE_OPERAND (ref1, 0), TREE_OPERAND (ref2, 0), 0)) | |
2684 | continue; | |
2685 | ||
2686 | field1 = TREE_OPERAND (ref1, 1); | |
2687 | field2 = TREE_OPERAND (ref2, 1); | |
2688 | ||
2689 | /* Check for field adjacency, and ensure field1 comes first. */ | |
2690 | for (next = DECL_CHAIN (field1); | |
2691 | next && TREE_CODE (next) != FIELD_DECL; | |
2692 | next = DECL_CHAIN (next)) | |
2693 | ; | |
2694 | ||
2695 | if (next != field2) | |
2696 | { | |
2697 | for (next = DECL_CHAIN (field2); | |
2698 | next && TREE_CODE (next) != FIELD_DECL; | |
2699 | next = DECL_CHAIN (next)) | |
2700 | ; | |
2701 | ||
2702 | if (next != field1) | |
2703 | continue; | |
2704 | ||
dfcf26a5 | 2705 | std::swap (field1, field2); |
2706 | std::swap (def1, def2); | |
239e9670 | 2707 | } |
2708 | ||
7c74ee50 | 2709 | bb_for_def1 = gimple_bb (def1); |
2710 | bb_for_def2 = gimple_bb (def2); | |
2711 | ||
239e9670 | 2712 | /* Check for proper alignment of the first field. */ |
2713 | tree_offset1 = bit_position (field1); | |
2714 | tree_offset2 = bit_position (field2); | |
2715 | tree_size2 = DECL_SIZE (field2); | |
2716 | ||
e913b5cd | 2717 | if (!tree_fits_uhwi_p (tree_offset1) |
2718 | || !tree_fits_uhwi_p (tree_offset2) | |
2719 | || !tree_fits_uhwi_p (tree_size2)) | |
239e9670 | 2720 | continue; |
2721 | ||
e913b5cd | 2722 | offset1 = tree_to_uhwi (tree_offset1); |
2723 | offset2 = tree_to_uhwi (tree_offset2); | |
2724 | size2 = tree_to_uhwi (tree_size2); | |
239e9670 | 2725 | align1 = DECL_ALIGN (field1) % param_align_bits; |
2726 | ||
2727 | if (offset1 % BITS_PER_UNIT != 0) | |
2728 | continue; | |
2729 | ||
2730 | /* For profitability, the two field references should fit within | |
2731 | a single cache line. */ | |
2732 | if (align1 + offset2 - offset1 + size2 > param_align_bits) | |
2733 | continue; | |
2734 | ||
2735 | /* The two expressions cannot be dependent upon vdefs defined | |
2736 | in bb1/bb2. */ | |
2737 | if (local_mem_dependence (def1, bb_for_def1) | |
2738 | || local_mem_dependence (def2, bb_for_def2)) | |
2739 | continue; | |
2740 | ||
2741 | /* The conditions are satisfied; hoist the loads from bb1 and bb2 into | |
2742 | bb0. We hoist the first one first so that a cache miss is handled | |
2743 | efficiently regardless of hardware cache-fill policy. */ | |
2744 | gsi2 = gsi_for_stmt (def1); | |
2745 | gsi_move_to_bb_end (&gsi2, bb0); | |
2746 | gsi2 = gsi_for_stmt (def2); | |
2747 | gsi_move_to_bb_end (&gsi2, bb0); | |
2748 | ||
2749 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2750 | { | |
2751 | fprintf (dump_file, | |
2752 | "\nHoisting adjacent loads from %d and %d into %d: \n", | |
2753 | bb_for_def1->index, bb_for_def2->index, bb0->index); | |
2754 | print_gimple_stmt (dump_file, def1, 0, TDF_VOPS|TDF_MEMSYMS); | |
2755 | print_gimple_stmt (dump_file, def2, 0, TDF_VOPS|TDF_MEMSYMS); | |
2756 | } | |
2757 | } | |
2758 | } | |
2759 | ||
2760 | /* Determine whether we should attempt to hoist adjacent loads out of | |
2761 | diamond patterns in pass_phiopt. Always hoist loads if | |
2762 | -fhoist-adjacent-loads is specified and the target machine has | |
6f0ddab1 | 2763 | both a conditional move instruction and a defined cache line size. */ |
239e9670 | 2764 | |
2765 | static bool | |
2766 | gate_hoist_loads (void) | |
2767 | { | |
6f0ddab1 | 2768 | return (flag_hoist_adjacent_loads == 1 |
2769 | && PARAM_VALUE (PARAM_L1_CACHE_LINE_SIZE) | |
2770 | && HAVE_conditional_move); | |
239e9670 | 2771 | } |
2772 | ||
65b0537f | 2773 | /* This pass tries to replaces an if-then-else block with an |
2774 | assignment. We have four kinds of transformations. Some of these | |
2775 | transformations are also performed by the ifcvt RTL optimizer. | |
2776 | ||
2777 | Conditional Replacement | |
2778 | ----------------------- | |
2779 | ||
2780 | This transformation, implemented in conditional_replacement, | |
2781 | replaces | |
2782 | ||
2783 | bb0: | |
2784 | if (cond) goto bb2; else goto bb1; | |
2785 | bb1: | |
2786 | bb2: | |
2787 | x = PHI <0 (bb1), 1 (bb0), ...>; | |
2788 | ||
2789 | with | |
2790 | ||
2791 | bb0: | |
2792 | x' = cond; | |
2793 | goto bb2; | |
2794 | bb2: | |
2795 | x = PHI <x' (bb0), ...>; | |
2796 | ||
2797 | We remove bb1 as it becomes unreachable. This occurs often due to | |
2798 | gimplification of conditionals. | |
2799 | ||
2800 | Value Replacement | |
2801 | ----------------- | |
2802 | ||
2803 | This transformation, implemented in value_replacement, replaces | |
2804 | ||
2805 | bb0: | |
2806 | if (a != b) goto bb2; else goto bb1; | |
2807 | bb1: | |
2808 | bb2: | |
2809 | x = PHI <a (bb1), b (bb0), ...>; | |
2810 | ||
2811 | with | |
2812 | ||
2813 | bb0: | |
2814 | bb2: | |
2815 | x = PHI <b (bb0), ...>; | |
2816 | ||
2817 | This opportunity can sometimes occur as a result of other | |
2818 | optimizations. | |
2819 | ||
2820 | ||
2821 | Another case caught by value replacement looks like this: | |
2822 | ||
2823 | bb0: | |
2824 | t1 = a == CONST; | |
2825 | t2 = b > c; | |
2826 | t3 = t1 & t2; | |
2827 | if (t3 != 0) goto bb1; else goto bb2; | |
2828 | bb1: | |
2829 | bb2: | |
2830 | x = PHI (CONST, a) | |
2831 | ||
2832 | Gets replaced with: | |
2833 | bb0: | |
2834 | bb2: | |
2835 | t1 = a == CONST; | |
2836 | t2 = b > c; | |
2837 | t3 = t1 & t2; | |
2838 | x = a; | |
2839 | ||
2840 | ABS Replacement | |
2841 | --------------- | |
2842 | ||
2843 | This transformation, implemented in abs_replacement, replaces | |
2844 | ||
2845 | bb0: | |
2846 | if (a >= 0) goto bb2; else goto bb1; | |
2847 | bb1: | |
2848 | x = -a; | |
2849 | bb2: | |
2850 | x = PHI <x (bb1), a (bb0), ...>; | |
2851 | ||
2852 | with | |
2853 | ||
2854 | bb0: | |
2855 | x' = ABS_EXPR< a >; | |
2856 | bb2: | |
2857 | x = PHI <x' (bb0), ...>; | |
2858 | ||
2859 | MIN/MAX Replacement | |
2860 | ------------------- | |
2861 | ||
2862 | This transformation, minmax_replacement replaces | |
2863 | ||
2864 | bb0: | |
2865 | if (a <= b) goto bb2; else goto bb1; | |
2866 | bb1: | |
2867 | bb2: | |
2868 | x = PHI <b (bb1), a (bb0), ...>; | |
2869 | ||
2870 | with | |
2871 | ||
2872 | bb0: | |
2873 | x' = MIN_EXPR (a, b) | |
2874 | bb2: | |
2875 | x = PHI <x' (bb0), ...>; | |
2876 | ||
2877 | A similar transformation is done for MAX_EXPR. | |
2878 | ||
2879 | ||
2880 | This pass also performs a fifth transformation of a slightly different | |
2881 | flavor. | |
2882 | ||
29a78fec | 2883 | Factor conversion in COND_EXPR |
2884 | ------------------------------ | |
2885 | ||
2886 | This transformation factors the conversion out of COND_EXPR with | |
2887 | factor_out_conditional_conversion. | |
2888 | ||
2889 | For example: | |
2890 | if (a <= CST) goto <bb 3>; else goto <bb 4>; | |
2891 | <bb 3>: | |
2892 | tmp = (int) a; | |
2893 | <bb 4>: | |
2894 | tmp = PHI <tmp, CST> | |
2895 | ||
2896 | Into: | |
2897 | if (a <= CST) goto <bb 3>; else goto <bb 4>; | |
2898 | <bb 3>: | |
2899 | <bb 4>: | |
2900 | a = PHI <a, CST> | |
2901 | tmp = (int) a; | |
2902 | ||
65b0537f | 2903 | Adjacent Load Hoisting |
2904 | ---------------------- | |
2905 | ||
2906 | This transformation replaces | |
2907 | ||
2908 | bb0: | |
2909 | if (...) goto bb2; else goto bb1; | |
2910 | bb1: | |
2911 | x1 = (<expr>).field1; | |
2912 | goto bb3; | |
2913 | bb2: | |
2914 | x2 = (<expr>).field2; | |
2915 | bb3: | |
2916 | # x = PHI <x1, x2>; | |
2917 | ||
2918 | with | |
2919 | ||
2920 | bb0: | |
2921 | x1 = (<expr>).field1; | |
2922 | x2 = (<expr>).field2; | |
2923 | if (...) goto bb2; else goto bb1; | |
2924 | bb1: | |
2925 | goto bb3; | |
2926 | bb2: | |
2927 | bb3: | |
2928 | # x = PHI <x1, x2>; | |
2929 | ||
2930 | The purpose of this transformation is to enable generation of conditional | |
2931 | move instructions such as Intel CMOVE or PowerPC ISEL. Because one of | |
2932 | the loads is speculative, the transformation is restricted to very | |
2933 | specific cases to avoid introducing a page fault. We are looking for | |
2934 | the common idiom: | |
2935 | ||
2936 | if (...) | |
2937 | x = y->left; | |
2938 | else | |
2939 | x = y->right; | |
2940 | ||
2941 | where left and right are typically adjacent pointers in a tree structure. */ | |
20e5647c | 2942 | |
cbe8bda8 | 2943 | namespace { |
2944 | ||
2945 | const pass_data pass_data_phiopt = | |
4ee9c684 | 2946 | { |
cbe8bda8 | 2947 | GIMPLE_PASS, /* type */ |
2948 | "phiopt", /* name */ | |
2949 | OPTGROUP_NONE, /* optinfo_flags */ | |
cbe8bda8 | 2950 | TV_TREE_PHIOPT, /* tv_id */ |
2951 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
2952 | 0, /* properties_provided */ | |
2953 | 0, /* properties_destroyed */ | |
2954 | 0, /* todo_flags_start */ | |
8b88439e | 2955 | 0, /* todo_flags_finish */ |
4ee9c684 | 2956 | }; |
e6d0e152 | 2957 | |
cbe8bda8 | 2958 | class pass_phiopt : public gimple_opt_pass |
2959 | { | |
2960 | public: | |
9af5ce0c | 2961 | pass_phiopt (gcc::context *ctxt) |
a2c2432d | 2962 | : gimple_opt_pass (pass_data_phiopt, ctxt), early_p (false) |
cbe8bda8 | 2963 | {} |
2964 | ||
2965 | /* opt_pass methods: */ | |
ae84f584 | 2966 | opt_pass * clone () { return new pass_phiopt (m_ctxt); } |
a2c2432d | 2967 | void set_pass_param (unsigned n, bool param) |
2968 | { | |
2969 | gcc_assert (n == 0); | |
2970 | early_p = param; | |
2971 | } | |
3dac50cc | 2972 | virtual bool gate (function *) { return flag_ssa_phiopt; } |
65b0537f | 2973 | virtual unsigned int execute (function *) |
2974 | { | |
a2c2432d | 2975 | return tree_ssa_phiopt_worker (false, |
2976 | !early_p ? gate_hoist_loads () : false, | |
2977 | early_p); | |
65b0537f | 2978 | } |
cbe8bda8 | 2979 | |
a2c2432d | 2980 | private: |
2981 | bool early_p; | |
cbe8bda8 | 2982 | }; // class pass_phiopt |
2983 | ||
2984 | } // anon namespace | |
2985 | ||
2986 | gimple_opt_pass * | |
2987 | make_pass_phiopt (gcc::context *ctxt) | |
2988 | { | |
2989 | return new pass_phiopt (ctxt); | |
2990 | } | |
2991 | ||
cbe8bda8 | 2992 | namespace { |
2993 | ||
2994 | const pass_data pass_data_cselim = | |
e6d0e152 | 2995 | { |
cbe8bda8 | 2996 | GIMPLE_PASS, /* type */ |
2997 | "cselim", /* name */ | |
2998 | OPTGROUP_NONE, /* optinfo_flags */ | |
cbe8bda8 | 2999 | TV_TREE_PHIOPT, /* tv_id */ |
3000 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
3001 | 0, /* properties_provided */ | |
3002 | 0, /* properties_destroyed */ | |
3003 | 0, /* todo_flags_start */ | |
8b88439e | 3004 | 0, /* todo_flags_finish */ |
e6d0e152 | 3005 | }; |
cbe8bda8 | 3006 | |
3007 | class pass_cselim : public gimple_opt_pass | |
3008 | { | |
3009 | public: | |
9af5ce0c | 3010 | pass_cselim (gcc::context *ctxt) |
3011 | : gimple_opt_pass (pass_data_cselim, ctxt) | |
cbe8bda8 | 3012 | {} |
3013 | ||
3014 | /* opt_pass methods: */ | |
31315c24 | 3015 | virtual bool gate (function *) { return flag_tree_cselim; } |
65b0537f | 3016 | virtual unsigned int execute (function *) { return tree_ssa_cs_elim (); } |
cbe8bda8 | 3017 | |
3018 | }; // class pass_cselim | |
3019 | ||
3020 | } // anon namespace | |
3021 | ||
3022 | gimple_opt_pass * | |
3023 | make_pass_cselim (gcc::context *ctxt) | |
3024 | { | |
3025 | return new pass_cselim (ctxt); | |
3026 | } |