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40923b20 | 1 | /* If-conversion for vectorizer. |
23a5b65a | 2 | Copyright (C) 2004-2014 Free Software Foundation, Inc. |
40923b20 DP |
3 | Contributed by Devang Patel <dpatel@apple.com> |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it under | |
8 | the terms of the GNU General Public License as published by the Free | |
9dcd6f09 | 9 | Software Foundation; either version 3, or (at your option) any later |
40923b20 DP |
10 | version. |
11 | ||
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
9dcd6f09 NC |
18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
40923b20 | 20 | |
98c07c54 SP |
21 | /* This pass implements a tree level if-conversion of loops. Its |
22 | initial goal is to help the vectorizer to vectorize loops with | |
23 | conditions. | |
40923b20 DP |
24 | |
25 | A short description of if-conversion: | |
26 | ||
e0ddb4bd | 27 | o Decide if a loop is if-convertible or not. |
40923b20 DP |
28 | o Walk all loop basic blocks in breadth first order (BFS order). |
29 | o Remove conditional statements (at the end of basic block) | |
61b5f210 | 30 | and propagate condition into destination basic blocks' |
40923b20 DP |
31 | predicate list. |
32 | o Replace modify expression with conditional modify expression | |
33 | using current basic block's condition. | |
34 | o Merge all basic blocks | |
35 | o Replace phi nodes with conditional modify expr | |
36 | o Merge all basic blocks into header | |
37 | ||
38 | Sample transformation: | |
39 | ||
40 | INPUT | |
41 | ----- | |
42 | ||
43 | # i_23 = PHI <0(0), i_18(10)>; | |
44 | <L0>:; | |
45 | j_15 = A[i_23]; | |
46 | if (j_15 > 41) goto <L1>; else goto <L17>; | |
47 | ||
48 | <L17>:; | |
49 | goto <bb 3> (<L3>); | |
50 | ||
51 | <L1>:; | |
52 | ||
53 | # iftmp.2_4 = PHI <0(8), 42(2)>; | |
54 | <L3>:; | |
55 | A[i_23] = iftmp.2_4; | |
56 | i_18 = i_23 + 1; | |
57 | if (i_18 <= 15) goto <L19>; else goto <L18>; | |
58 | ||
59 | <L19>:; | |
60 | goto <bb 1> (<L0>); | |
61 | ||
62 | <L18>:; | |
63 | ||
64 | OUTPUT | |
65 | ------ | |
66 | ||
67 | # i_23 = PHI <0(0), i_18(10)>; | |
68 | <L0>:; | |
69 | j_15 = A[i_23]; | |
61b5f210 | 70 | |
40923b20 DP |
71 | <L3>:; |
72 | iftmp.2_4 = j_15 > 41 ? 42 : 0; | |
73 | A[i_23] = iftmp.2_4; | |
74 | i_18 = i_23 + 1; | |
75 | if (i_18 <= 15) goto <L19>; else goto <L18>; | |
61b5f210 | 76 | |
40923b20 DP |
77 | <L19>:; |
78 | goto <bb 1> (<L0>); | |
79 | ||
80 | <L18>:; | |
81 | */ | |
82 | ||
83 | #include "config.h" | |
84 | #include "system.h" | |
85 | #include "coretypes.h" | |
86 | #include "tm.h" | |
40923b20 | 87 | #include "tree.h" |
d8a2d370 | 88 | #include "stor-layout.h" |
40923b20 | 89 | #include "flags.h" |
40923b20 | 90 | #include "basic-block.h" |
cf835838 | 91 | #include "gimple-pretty-print.h" |
2fb9a547 AM |
92 | #include "tree-ssa-alias.h" |
93 | #include "internal-fn.h" | |
94 | #include "gimple-fold.h" | |
95 | #include "gimple-expr.h" | |
96 | #include "is-a.h" | |
18f429e2 | 97 | #include "gimple.h" |
45b0be94 | 98 | #include "gimplify.h" |
5be5c238 | 99 | #include "gimple-iterator.h" |
18f429e2 | 100 | #include "gimplify-me.h" |
442b4905 AM |
101 | #include "gimple-ssa.h" |
102 | #include "tree-cfg.h" | |
103 | #include "tree-phinodes.h" | |
104 | #include "ssa-iterators.h" | |
d8a2d370 | 105 | #include "stringpool.h" |
442b4905 AM |
106 | #include "tree-ssanames.h" |
107 | #include "tree-into-ssa.h" | |
7a300452 | 108 | #include "tree-ssa.h" |
40923b20 DP |
109 | #include "cfgloop.h" |
110 | #include "tree-chrec.h" | |
111 | #include "tree-data-ref.h" | |
112 | #include "tree-scalar-evolution.h" | |
5ce9450f JJ |
113 | #include "tree-ssa-loop-ivopts.h" |
114 | #include "tree-ssa-address.h" | |
40923b20 | 115 | #include "tree-pass.h" |
53aa40a8 | 116 | #include "dbgcnt.h" |
5ce9450f JJ |
117 | #include "expr.h" |
118 | #include "optabs.h" | |
40923b20 | 119 | |
40923b20 DP |
120 | /* List of basic blocks in if-conversion-suitable order. */ |
121 | static basic_block *ifc_bbs; | |
122 | ||
7b14477e SP |
123 | /* Structure used to predicate basic blocks. This is attached to the |
124 | ->aux field of the BBs in the loop to be if-converted. */ | |
125 | typedef struct bb_predicate_s { | |
126 | ||
127 | /* The condition under which this basic block is executed. */ | |
128 | tree predicate; | |
129 | ||
130 | /* PREDICATE is gimplified, and the sequence of statements is | |
131 | recorded here, in order to avoid the duplication of computations | |
132 | that occur in previous conditions. See PR44483. */ | |
133 | gimple_seq predicate_gimplified_stmts; | |
134 | } *bb_predicate_p; | |
135 | ||
136 | /* Returns true when the basic block BB has a predicate. */ | |
137 | ||
138 | static inline bool | |
139 | bb_has_predicate (basic_block bb) | |
140 | { | |
141 | return bb->aux != NULL; | |
142 | } | |
143 | ||
144 | /* Returns the gimplified predicate for basic block BB. */ | |
145 | ||
146 | static inline tree | |
147 | bb_predicate (basic_block bb) | |
148 | { | |
149 | return ((bb_predicate_p) bb->aux)->predicate; | |
150 | } | |
151 | ||
152 | /* Sets the gimplified predicate COND for basic block BB. */ | |
153 | ||
154 | static inline void | |
155 | set_bb_predicate (basic_block bb, tree cond) | |
156 | { | |
747633c5 RG |
157 | gcc_assert ((TREE_CODE (cond) == TRUTH_NOT_EXPR |
158 | && is_gimple_condexpr (TREE_OPERAND (cond, 0))) | |
159 | || is_gimple_condexpr (cond)); | |
7b14477e SP |
160 | ((bb_predicate_p) bb->aux)->predicate = cond; |
161 | } | |
162 | ||
163 | /* Returns the sequence of statements of the gimplification of the | |
164 | predicate for basic block BB. */ | |
165 | ||
166 | static inline gimple_seq | |
167 | bb_predicate_gimplified_stmts (basic_block bb) | |
168 | { | |
169 | return ((bb_predicate_p) bb->aux)->predicate_gimplified_stmts; | |
170 | } | |
171 | ||
172 | /* Sets the sequence of statements STMTS of the gimplification of the | |
173 | predicate for basic block BB. */ | |
174 | ||
175 | static inline void | |
176 | set_bb_predicate_gimplified_stmts (basic_block bb, gimple_seq stmts) | |
177 | { | |
178 | ((bb_predicate_p) bb->aux)->predicate_gimplified_stmts = stmts; | |
179 | } | |
180 | ||
181 | /* Adds the sequence of statements STMTS to the sequence of statements | |
182 | of the predicate for basic block BB. */ | |
183 | ||
184 | static inline void | |
185 | add_bb_predicate_gimplified_stmts (basic_block bb, gimple_seq stmts) | |
186 | { | |
187 | gimple_seq_add_seq | |
188 | (&(((bb_predicate_p) bb->aux)->predicate_gimplified_stmts), stmts); | |
189 | } | |
190 | ||
191 | /* Initializes to TRUE the predicate of basic block BB. */ | |
192 | ||
193 | static inline void | |
194 | init_bb_predicate (basic_block bb) | |
195 | { | |
196 | bb->aux = XNEW (struct bb_predicate_s); | |
197 | set_bb_predicate_gimplified_stmts (bb, NULL); | |
29caa68a | 198 | set_bb_predicate (bb, boolean_true_node); |
7b14477e SP |
199 | } |
200 | ||
5ce9450f JJ |
201 | /* Release the SSA_NAMEs associated with the predicate of basic block BB, |
202 | but don't actually free it. */ | |
7b14477e SP |
203 | |
204 | static inline void | |
5ce9450f | 205 | release_bb_predicate (basic_block bb) |
7b14477e | 206 | { |
5ce9450f | 207 | gimple_seq stmts = bb_predicate_gimplified_stmts (bb); |
7b14477e SP |
208 | if (stmts) |
209 | { | |
210 | gimple_stmt_iterator i; | |
211 | ||
212 | for (i = gsi_start (stmts); !gsi_end_p (i); gsi_next (&i)) | |
6a58ccca | 213 | free_stmt_operands (cfun, gsi_stmt (i)); |
5ce9450f | 214 | set_bb_predicate_gimplified_stmts (bb, NULL); |
7b14477e | 215 | } |
5ce9450f JJ |
216 | } |
217 | ||
218 | /* Free the predicate of basic block BB. */ | |
7b14477e | 219 | |
5ce9450f JJ |
220 | static inline void |
221 | free_bb_predicate (basic_block bb) | |
222 | { | |
223 | if (!bb_has_predicate (bb)) | |
224 | return; | |
225 | ||
226 | release_bb_predicate (bb); | |
7b14477e SP |
227 | free (bb->aux); |
228 | bb->aux = NULL; | |
229 | } | |
230 | ||
5ce9450f | 231 | /* Reinitialize predicate of BB with the true predicate. */ |
29caa68a SP |
232 | |
233 | static inline void | |
234 | reset_bb_predicate (basic_block bb) | |
235 | { | |
5ce9450f JJ |
236 | if (!bb_has_predicate (bb)) |
237 | init_bb_predicate (bb); | |
238 | else | |
239 | { | |
240 | release_bb_predicate (bb); | |
241 | set_bb_predicate (bb, boolean_true_node); | |
242 | } | |
29caa68a SP |
243 | } |
244 | ||
bd544141 SP |
245 | /* Returns a new SSA_NAME of type TYPE that is assigned the value of |
246 | the expression EXPR. Inserts the statement created for this | |
247 | computation before GSI and leaves the iterator GSI at the same | |
248 | statement. */ | |
40923b20 | 249 | |
bd544141 SP |
250 | static tree |
251 | ifc_temp_var (tree type, tree expr, gimple_stmt_iterator *gsi) | |
40923b20 | 252 | { |
83d5977e RG |
253 | tree new_name = make_temp_ssa_name (type, NULL, "_ifc_"); |
254 | gimple stmt = gimple_build_assign (new_name, expr); | |
bd544141 | 255 | gsi_insert_before (gsi, stmt, GSI_SAME_STMT); |
83d5977e | 256 | return new_name; |
baaa8e96 SP |
257 | } |
258 | ||
0247298c SP |
259 | /* Return true when COND is a true predicate. */ |
260 | ||
261 | static inline bool | |
262 | is_true_predicate (tree cond) | |
263 | { | |
264 | return (cond == NULL_TREE | |
265 | || cond == boolean_true_node | |
266 | || integer_onep (cond)); | |
267 | } | |
268 | ||
269 | /* Returns true when BB has a predicate that is not trivial: true or | |
270 | NULL_TREE. */ | |
271 | ||
272 | static inline bool | |
273 | is_predicated (basic_block bb) | |
274 | { | |
7b14477e | 275 | return !is_true_predicate (bb_predicate (bb)); |
0247298c SP |
276 | } |
277 | ||
d89e5e20 SP |
278 | /* Parses the predicate COND and returns its comparison code and |
279 | operands OP0 and OP1. */ | |
280 | ||
281 | static enum tree_code | |
282 | parse_predicate (tree cond, tree *op0, tree *op1) | |
283 | { | |
284 | gimple s; | |
285 | ||
286 | if (TREE_CODE (cond) == SSA_NAME | |
287 | && is_gimple_assign (s = SSA_NAME_DEF_STMT (cond))) | |
288 | { | |
289 | if (TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison) | |
290 | { | |
291 | *op0 = gimple_assign_rhs1 (s); | |
292 | *op1 = gimple_assign_rhs2 (s); | |
293 | return gimple_assign_rhs_code (s); | |
294 | } | |
295 | ||
296 | else if (gimple_assign_rhs_code (s) == TRUTH_NOT_EXPR) | |
297 | { | |
298 | tree op = gimple_assign_rhs1 (s); | |
299 | tree type = TREE_TYPE (op); | |
300 | enum tree_code code = parse_predicate (op, op0, op1); | |
301 | ||
302 | return code == ERROR_MARK ? ERROR_MARK | |
303 | : invert_tree_comparison (code, HONOR_NANS (TYPE_MODE (type))); | |
304 | } | |
305 | ||
306 | return ERROR_MARK; | |
307 | } | |
308 | ||
309 | if (TREE_CODE_CLASS (TREE_CODE (cond)) == tcc_comparison) | |
310 | { | |
311 | *op0 = TREE_OPERAND (cond, 0); | |
312 | *op1 = TREE_OPERAND (cond, 1); | |
313 | return TREE_CODE (cond); | |
314 | } | |
315 | ||
316 | return ERROR_MARK; | |
317 | } | |
318 | ||
59ee2304 SP |
319 | /* Returns the fold of predicate C1 OR C2 at location LOC. */ |
320 | ||
321 | static tree | |
322 | fold_or_predicates (location_t loc, tree c1, tree c2) | |
323 | { | |
324 | tree op1a, op1b, op2a, op2b; | |
325 | enum tree_code code1 = parse_predicate (c1, &op1a, &op1b); | |
326 | enum tree_code code2 = parse_predicate (c2, &op2a, &op2b); | |
327 | ||
328 | if (code1 != ERROR_MARK && code2 != ERROR_MARK) | |
329 | { | |
330 | tree t = maybe_fold_or_comparisons (code1, op1a, op1b, | |
331 | code2, op2a, op2b); | |
332 | if (t) | |
333 | return t; | |
334 | } | |
335 | ||
336 | return fold_build2_loc (loc, TRUTH_OR_EXPR, boolean_type_node, c1, c2); | |
337 | } | |
338 | ||
f35613b2 AP |
339 | /* Returns true if N is either a constant or a SSA_NAME. */ |
340 | ||
341 | static bool | |
342 | constant_or_ssa_name (tree n) | |
343 | { | |
344 | switch (TREE_CODE (n)) | |
345 | { | |
346 | case SSA_NAME: | |
347 | case INTEGER_CST: | |
348 | case REAL_CST: | |
349 | case COMPLEX_CST: | |
350 | case VECTOR_CST: | |
351 | return true; | |
352 | default: | |
353 | return false; | |
354 | } | |
355 | } | |
356 | ||
357 | /* Returns either a COND_EXPR or the folded expression if the folded | |
358 | expression is a MIN_EXPR, a MAX_EXPR, an ABS_EXPR, | |
359 | a constant or a SSA_NAME. */ | |
360 | ||
361 | static tree | |
362 | fold_build_cond_expr (tree type, tree cond, tree rhs, tree lhs) | |
363 | { | |
364 | tree rhs1, lhs1, cond_expr; | |
365 | cond_expr = fold_ternary (COND_EXPR, type, cond, | |
366 | rhs, lhs); | |
367 | ||
368 | if (cond_expr == NULL_TREE) | |
369 | return build3 (COND_EXPR, type, cond, rhs, lhs); | |
370 | ||
371 | STRIP_USELESS_TYPE_CONVERSION (cond_expr); | |
372 | ||
373 | if (constant_or_ssa_name (cond_expr)) | |
374 | return cond_expr; | |
375 | ||
376 | if (TREE_CODE (cond_expr) == ABS_EXPR) | |
377 | { | |
378 | rhs1 = TREE_OPERAND (cond_expr, 1); | |
379 | STRIP_USELESS_TYPE_CONVERSION (rhs1); | |
380 | if (constant_or_ssa_name (rhs1)) | |
381 | return build1 (ABS_EXPR, type, rhs1); | |
382 | } | |
383 | ||
384 | if (TREE_CODE (cond_expr) == MIN_EXPR | |
385 | || TREE_CODE (cond_expr) == MAX_EXPR) | |
386 | { | |
387 | lhs1 = TREE_OPERAND (cond_expr, 0); | |
388 | STRIP_USELESS_TYPE_CONVERSION (lhs1); | |
389 | rhs1 = TREE_OPERAND (cond_expr, 1); | |
390 | STRIP_USELESS_TYPE_CONVERSION (rhs1); | |
391 | if (constant_or_ssa_name (rhs1) | |
392 | && constant_or_ssa_name (lhs1)) | |
393 | return build2 (TREE_CODE (cond_expr), type, lhs1, rhs1); | |
394 | } | |
395 | return build3 (COND_EXPR, type, cond, rhs, lhs); | |
396 | } | |
397 | ||
5ce9450f JJ |
398 | /* Add condition NC to the predicate list of basic block BB. LOOP is |
399 | the loop to be if-converted. */ | |
baaa8e96 | 400 | |
0247298c | 401 | static inline void |
5ce9450f | 402 | add_to_predicate_list (struct loop *loop, basic_block bb, tree nc) |
baaa8e96 | 403 | { |
747633c5 | 404 | tree bc, *tp; |
d89e5e20 SP |
405 | |
406 | if (is_true_predicate (nc)) | |
407 | return; | |
408 | ||
409 | if (!is_predicated (bb)) | |
5ce9450f JJ |
410 | { |
411 | /* If dominance tells us this basic block is always executed, don't | |
412 | record any predicates for it. */ | |
413 | if (dominated_by_p (CDI_DOMINATORS, loop->latch, bb)) | |
414 | return; | |
415 | ||
416 | bc = nc; | |
417 | } | |
d89e5e20 SP |
418 | else |
419 | { | |
d89e5e20 | 420 | bc = bb_predicate (bb); |
59ee2304 | 421 | bc = fold_or_predicates (EXPR_LOCATION (bc), nc, bc); |
747633c5 RG |
422 | if (is_true_predicate (bc)) |
423 | { | |
424 | reset_bb_predicate (bb); | |
425 | return; | |
426 | } | |
d89e5e20 SP |
427 | } |
428 | ||
747633c5 RG |
429 | /* Allow a TRUTH_NOT_EXPR around the main predicate. */ |
430 | if (TREE_CODE (bc) == TRUTH_NOT_EXPR) | |
431 | tp = &TREE_OPERAND (bc, 0); | |
432 | else | |
433 | tp = &bc; | |
434 | if (!is_gimple_condexpr (*tp)) | |
d89e5e20 SP |
435 | { |
436 | gimple_seq stmts; | |
747633c5 | 437 | *tp = force_gimple_operand_1 (*tp, &stmts, is_gimple_condexpr, NULL_TREE); |
d89e5e20 SP |
438 | add_bb_predicate_gimplified_stmts (bb, stmts); |
439 | } | |
747633c5 | 440 | set_bb_predicate (bb, bc); |
baaa8e96 SP |
441 | } |
442 | ||
e1449456 SP |
443 | /* Add the condition COND to the previous condition PREV_COND, and add |
444 | this to the predicate list of the destination of edge E. LOOP is | |
445 | the loop to be if-converted. */ | |
baaa8e96 | 446 | |
0247298c | 447 | static void |
baaa8e96 | 448 | add_to_dst_predicate_list (struct loop *loop, edge e, |
e1449456 | 449 | tree prev_cond, tree cond) |
baaa8e96 | 450 | { |
baaa8e96 | 451 | if (!flow_bb_inside_loop_p (loop, e->dest)) |
0247298c | 452 | return; |
baaa8e96 | 453 | |
0247298c SP |
454 | if (!is_true_predicate (prev_cond)) |
455 | cond = fold_build2 (TRUTH_AND_EXPR, boolean_type_node, | |
456 | prev_cond, cond); | |
40923b20 | 457 | |
5ce9450f | 458 | add_to_predicate_list (loop, e->dest, cond); |
baaa8e96 | 459 | } |
8ad02175 | 460 | |
98c07c54 | 461 | /* Return true if one of the successor edges of BB exits LOOP. */ |
40923b20 | 462 | |
baaa8e96 SP |
463 | static bool |
464 | bb_with_exit_edge_p (struct loop *loop, basic_block bb) | |
465 | { | |
466 | edge e; | |
467 | edge_iterator ei; | |
40923b20 | 468 | |
baaa8e96 SP |
469 | FOR_EACH_EDGE (e, ei, bb->succs) |
470 | if (loop_exit_edge_p (loop, e)) | |
98c07c54 | 471 | return true; |
40923b20 | 472 | |
98c07c54 | 473 | return false; |
baaa8e96 | 474 | } |
77bd31de | 475 | |
98c07c54 | 476 | /* Return true when PHI is if-convertible. PHI is part of loop LOOP |
40923b20 | 477 | and it belongs to basic block BB. |
98c07c54 SP |
478 | |
479 | PHI is not if-convertible if: | |
bd544141 SP |
480 | - it has more than 2 arguments. |
481 | ||
482 | When the flag_tree_loop_if_convert_stores is not set, PHI is not | |
483 | if-convertible if: | |
484 | - a virtual PHI is immediately used in another PHI node, | |
485 | - there is a virtual PHI in a BB other than the loop->header. */ | |
40923b20 DP |
486 | |
487 | static bool | |
5ce9450f JJ |
488 | if_convertible_phi_p (struct loop *loop, basic_block bb, gimple phi, |
489 | bool any_mask_load_store) | |
40923b20 DP |
490 | { |
491 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
492 | { | |
493 | fprintf (dump_file, "-------------------------\n"); | |
726a989a | 494 | print_gimple_stmt (dump_file, phi, 0, TDF_SLIM); |
40923b20 | 495 | } |
61b5f210 | 496 | |
726a989a | 497 | if (bb != loop->header && gimple_phi_num_args (phi) != 2) |
40923b20 DP |
498 | { |
499 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
500 | fprintf (dump_file, "More than two phi node args.\n"); | |
501 | return false; | |
502 | } | |
61b5f210 | 503 | |
5ce9450f | 504 | if (flag_tree_loop_if_convert_stores || any_mask_load_store) |
bd544141 SP |
505 | return true; |
506 | ||
507 | /* When the flag_tree_loop_if_convert_stores is not set, check | |
508 | that there are no memory writes in the branches of the loop to be | |
509 | if-converted. */ | |
ea057359 | 510 | if (virtual_operand_p (gimple_phi_result (phi))) |
40923b20 | 511 | { |
f430bae8 AM |
512 | imm_use_iterator imm_iter; |
513 | use_operand_p use_p; | |
93d15c33 JJ |
514 | |
515 | if (bb != loop->header) | |
516 | { | |
517 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
bd544141 | 518 | fprintf (dump_file, "Virtual phi not on loop->header.\n"); |
93d15c33 JJ |
519 | return false; |
520 | } | |
bd544141 | 521 | |
726a989a | 522 | FOR_EACH_IMM_USE_FAST (use_p, imm_iter, gimple_phi_result (phi)) |
40923b20 | 523 | { |
726a989a | 524 | if (gimple_code (USE_STMT (use_p)) == GIMPLE_PHI) |
40923b20 DP |
525 | { |
526 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
527 | fprintf (dump_file, "Difficult to handle this virtual phi.\n"); | |
528 | return false; | |
529 | } | |
530 | } | |
531 | } | |
532 | ||
533 | return true; | |
534 | } | |
535 | ||
4b9c23ea SP |
536 | /* Records the status of a data reference. This struct is attached to |
537 | each DR->aux field. */ | |
538 | ||
539 | struct ifc_dr { | |
540 | /* -1 when not initialized, 0 when false, 1 when true. */ | |
541 | int written_at_least_once; | |
542 | ||
543 | /* -1 when not initialized, 0 when false, 1 when true. */ | |
544 | int rw_unconditionally; | |
545 | }; | |
546 | ||
547 | #define IFC_DR(DR) ((struct ifc_dr *) (DR)->aux) | |
548 | #define DR_WRITTEN_AT_LEAST_ONCE(DR) (IFC_DR (DR)->written_at_least_once) | |
549 | #define DR_RW_UNCONDITIONALLY(DR) (IFC_DR (DR)->rw_unconditionally) | |
550 | ||
e1fd038a SP |
551 | /* Returns true when the memory references of STMT are read or written |
552 | unconditionally. In other words, this function returns true when | |
553 | for every data reference A in STMT there exist other accesses to | |
4979c28b RG |
554 | a data reference with the same base with predicates that add up (OR-up) to |
555 | the true predicate: this ensures that the data reference A is touched | |
e1fd038a SP |
556 | (read or written) on every iteration of the if-converted loop. */ |
557 | ||
558 | static bool | |
559 | memrefs_read_or_written_unconditionally (gimple stmt, | |
9771b263 | 560 | vec<data_reference_p> drs) |
e1fd038a SP |
561 | { |
562 | int i, j; | |
563 | data_reference_p a, b; | |
564 | tree ca = bb_predicate (gimple_bb (stmt)); | |
565 | ||
9771b263 | 566 | for (i = 0; drs.iterate (i, &a); i++) |
e1fd038a SP |
567 | if (DR_STMT (a) == stmt) |
568 | { | |
569 | bool found = false; | |
4b9c23ea SP |
570 | int x = DR_RW_UNCONDITIONALLY (a); |
571 | ||
572 | if (x == 0) | |
573 | return false; | |
574 | ||
575 | if (x == 1) | |
576 | continue; | |
e1fd038a | 577 | |
9771b263 | 578 | for (j = 0; drs.iterate (j, &b); j++) |
4979c28b RG |
579 | { |
580 | tree ref_base_a = DR_REF (a); | |
581 | tree ref_base_b = DR_REF (b); | |
582 | ||
583 | if (DR_STMT (b) == stmt) | |
584 | continue; | |
585 | ||
586 | while (TREE_CODE (ref_base_a) == COMPONENT_REF | |
587 | || TREE_CODE (ref_base_a) == IMAGPART_EXPR | |
588 | || TREE_CODE (ref_base_a) == REALPART_EXPR) | |
589 | ref_base_a = TREE_OPERAND (ref_base_a, 0); | |
590 | ||
591 | while (TREE_CODE (ref_base_b) == COMPONENT_REF | |
592 | || TREE_CODE (ref_base_b) == IMAGPART_EXPR | |
593 | || TREE_CODE (ref_base_b) == REALPART_EXPR) | |
594 | ref_base_b = TREE_OPERAND (ref_base_b, 0); | |
595 | ||
596 | if (!operand_equal_p (ref_base_a, ref_base_b, 0)) | |
597 | { | |
598 | tree cb = bb_predicate (gimple_bb (DR_STMT (b))); | |
599 | ||
600 | if (DR_RW_UNCONDITIONALLY (b) == 1 | |
601 | || is_true_predicate (cb) | |
602 | || is_true_predicate (ca | |
603 | = fold_or_predicates (EXPR_LOCATION (cb), ca, cb))) | |
604 | { | |
605 | DR_RW_UNCONDITIONALLY (a) = 1; | |
606 | DR_RW_UNCONDITIONALLY (b) = 1; | |
607 | found = true; | |
608 | break; | |
609 | } | |
610 | } | |
e1fd038a SP |
611 | } |
612 | ||
613 | if (!found) | |
4b9c23ea SP |
614 | { |
615 | DR_RW_UNCONDITIONALLY (a) = 0; | |
616 | return false; | |
617 | } | |
e1fd038a SP |
618 | } |
619 | ||
620 | return true; | |
621 | } | |
622 | ||
623 | /* Returns true when the memory references of STMT are unconditionally | |
624 | written. In other words, this function returns true when for every | |
625 | data reference A written in STMT, there exist other writes to the | |
626 | same data reference with predicates that add up (OR-up) to the true | |
627 | predicate: this ensures that the data reference A is written on | |
628 | every iteration of the if-converted loop. */ | |
629 | ||
630 | static bool | |
631 | write_memrefs_written_at_least_once (gimple stmt, | |
9771b263 | 632 | vec<data_reference_p> drs) |
e1fd038a SP |
633 | { |
634 | int i, j; | |
635 | data_reference_p a, b; | |
636 | tree ca = bb_predicate (gimple_bb (stmt)); | |
637 | ||
9771b263 | 638 | for (i = 0; drs.iterate (i, &a); i++) |
e1fd038a | 639 | if (DR_STMT (a) == stmt |
b0af49c4 | 640 | && DR_IS_WRITE (a)) |
e1fd038a SP |
641 | { |
642 | bool found = false; | |
4b9c23ea SP |
643 | int x = DR_WRITTEN_AT_LEAST_ONCE (a); |
644 | ||
645 | if (x == 0) | |
646 | return false; | |
647 | ||
648 | if (x == 1) | |
649 | continue; | |
e1fd038a | 650 | |
9771b263 | 651 | for (j = 0; drs.iterate (j, &b); j++) |
e1fd038a | 652 | if (DR_STMT (b) != stmt |
b0af49c4 | 653 | && DR_IS_WRITE (b) |
e1fd038a SP |
654 | && same_data_refs_base_objects (a, b)) |
655 | { | |
656 | tree cb = bb_predicate (gimple_bb (DR_STMT (b))); | |
657 | ||
4b9c23ea SP |
658 | if (DR_WRITTEN_AT_LEAST_ONCE (b) == 1 |
659 | || is_true_predicate (cb) | |
e1fd038a SP |
660 | || is_true_predicate (ca = fold_or_predicates (EXPR_LOCATION (cb), |
661 | ca, cb))) | |
662 | { | |
4b9c23ea SP |
663 | DR_WRITTEN_AT_LEAST_ONCE (a) = 1; |
664 | DR_WRITTEN_AT_LEAST_ONCE (b) = 1; | |
e1fd038a SP |
665 | found = true; |
666 | break; | |
667 | } | |
668 | } | |
669 | ||
670 | if (!found) | |
4b9c23ea SP |
671 | { |
672 | DR_WRITTEN_AT_LEAST_ONCE (a) = 0; | |
673 | return false; | |
674 | } | |
e1fd038a SP |
675 | } |
676 | ||
677 | return true; | |
678 | } | |
679 | ||
680 | /* Return true when the memory references of STMT won't trap in the | |
681 | if-converted code. There are two things that we have to check for: | |
682 | ||
683 | - writes to memory occur to writable memory: if-conversion of | |
684 | memory writes transforms the conditional memory writes into | |
685 | unconditional writes, i.e. "if (cond) A[i] = foo" is transformed | |
686 | into "A[i] = cond ? foo : A[i]", and as the write to memory may not | |
687 | be executed at all in the original code, it may be a readonly | |
688 | memory. To check that A is not const-qualified, we check that | |
689 | there exists at least an unconditional write to A in the current | |
690 | function. | |
691 | ||
692 | - reads or writes to memory are valid memory accesses for every | |
693 | iteration. To check that the memory accesses are correctly formed | |
694 | and that we are allowed to read and write in these locations, we | |
695 | check that the memory accesses to be if-converted occur at every | |
696 | iteration unconditionally. */ | |
697 | ||
698 | static bool | |
9771b263 | 699 | ifcvt_memrefs_wont_trap (gimple stmt, vec<data_reference_p> refs) |
e1fd038a SP |
700 | { |
701 | return write_memrefs_written_at_least_once (stmt, refs) | |
702 | && memrefs_read_or_written_unconditionally (stmt, refs); | |
703 | } | |
704 | ||
705 | /* Wrapper around gimple_could_trap_p refined for the needs of the | |
706 | if-conversion. Try to prove that the memory accesses of STMT could | |
707 | not trap in the innermost loop containing STMT. */ | |
708 | ||
709 | static bool | |
9771b263 | 710 | ifcvt_could_trap_p (gimple stmt, vec<data_reference_p> refs) |
e1fd038a SP |
711 | { |
712 | if (gimple_vuse (stmt) | |
713 | && !gimple_could_trap_p_1 (stmt, false, false) | |
714 | && ifcvt_memrefs_wont_trap (stmt, refs)) | |
715 | return false; | |
716 | ||
717 | return gimple_could_trap_p (stmt); | |
718 | } | |
719 | ||
5ce9450f JJ |
720 | /* Return true if STMT could be converted into a masked load or store |
721 | (conditional load or store based on a mask computed from bb predicate). */ | |
722 | ||
723 | static bool | |
724 | ifcvt_can_use_mask_load_store (gimple stmt) | |
725 | { | |
726 | tree lhs, ref; | |
727 | enum machine_mode mode; | |
728 | basic_block bb = gimple_bb (stmt); | |
729 | bool is_load; | |
730 | ||
b15b5979 | 731 | if (!(flag_tree_loop_vectorize || bb->loop_father->force_vectorize) |
5ce9450f JJ |
732 | || bb->loop_father->dont_vectorize |
733 | || !gimple_assign_single_p (stmt) | |
734 | || gimple_has_volatile_ops (stmt)) | |
735 | return false; | |
736 | ||
737 | /* Check whether this is a load or store. */ | |
738 | lhs = gimple_assign_lhs (stmt); | |
739 | if (gimple_store_p (stmt)) | |
740 | { | |
741 | if (!is_gimple_val (gimple_assign_rhs1 (stmt))) | |
742 | return false; | |
743 | is_load = false; | |
744 | ref = lhs; | |
745 | } | |
746 | else if (gimple_assign_load_p (stmt)) | |
747 | { | |
748 | is_load = true; | |
749 | ref = gimple_assign_rhs1 (stmt); | |
750 | } | |
751 | else | |
752 | return false; | |
753 | ||
754 | if (may_be_nonaddressable_p (ref)) | |
755 | return false; | |
756 | ||
757 | /* Mask should be integer mode of the same size as the load/store | |
758 | mode. */ | |
759 | mode = TYPE_MODE (TREE_TYPE (lhs)); | |
760 | if (int_mode_for_mode (mode) == BLKmode | |
761 | || VECTOR_MODE_P (mode)) | |
762 | return false; | |
763 | ||
764 | if (can_vec_mask_load_store_p (mode, is_load)) | |
765 | return true; | |
766 | ||
767 | return false; | |
768 | } | |
769 | ||
98c07c54 SP |
770 | /* Return true when STMT is if-convertible. |
771 | ||
726a989a | 772 | GIMPLE_ASSIGN statement is not if-convertible if, |
b6779d81 SP |
773 | - it is not movable, |
774 | - it could trap, | |
bd544141 | 775 | - LHS is not var decl. */ |
40923b20 DP |
776 | |
777 | static bool | |
e1fd038a | 778 | if_convertible_gimple_assign_stmt_p (gimple stmt, |
5ce9450f JJ |
779 | vec<data_reference_p> refs, |
780 | bool *any_mask_load_store) | |
40923b20 | 781 | { |
98c07c54 | 782 | tree lhs = gimple_assign_lhs (stmt); |
bd544141 | 783 | basic_block bb; |
3ece6cc2 | 784 | |
40923b20 DP |
785 | if (dump_file && (dump_flags & TDF_DETAILS)) |
786 | { | |
787 | fprintf (dump_file, "-------------------------\n"); | |
726a989a | 788 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); |
40923b20 | 789 | } |
61b5f210 | 790 | |
bd544141 SP |
791 | if (!is_gimple_reg_type (TREE_TYPE (lhs))) |
792 | return false; | |
793 | ||
3ece6cc2 | 794 | /* Some of these constrains might be too conservative. */ |
726a989a RB |
795 | if (stmt_ends_bb_p (stmt) |
796 | || gimple_has_volatile_ops (stmt) | |
3ece6cc2 RE |
797 | || (TREE_CODE (lhs) == SSA_NAME |
798 | && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
726a989a | 799 | || gimple_has_side_effects (stmt)) |
40923b20 DP |
800 | { |
801 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3ece6cc2 | 802 | fprintf (dump_file, "stmt not suitable for ifcvt\n"); |
40923b20 DP |
803 | return false; |
804 | } | |
805 | ||
5ce9450f JJ |
806 | /* tree-into-ssa.c uses GF_PLF_1, so avoid it, because |
807 | in between if_convertible_loop_p and combine_blocks | |
808 | we can perform loop versioning. */ | |
809 | gimple_set_plf (stmt, GF_PLF_2, false); | |
810 | ||
bd544141 SP |
811 | if (flag_tree_loop_if_convert_stores) |
812 | { | |
e1fd038a | 813 | if (ifcvt_could_trap_p (stmt, refs)) |
bd544141 | 814 | { |
5ce9450f JJ |
815 | if (ifcvt_can_use_mask_load_store (stmt)) |
816 | { | |
817 | gimple_set_plf (stmt, GF_PLF_2, true); | |
818 | *any_mask_load_store = true; | |
819 | return true; | |
820 | } | |
bd544141 SP |
821 | if (dump_file && (dump_flags & TDF_DETAILS)) |
822 | fprintf (dump_file, "tree could trap...\n"); | |
823 | return false; | |
824 | } | |
825 | return true; | |
826 | } | |
827 | ||
4204425f | 828 | if (gimple_assign_rhs_could_trap_p (stmt)) |
40923b20 | 829 | { |
5ce9450f JJ |
830 | if (ifcvt_can_use_mask_load_store (stmt)) |
831 | { | |
832 | gimple_set_plf (stmt, GF_PLF_2, true); | |
833 | *any_mask_load_store = true; | |
834 | return true; | |
835 | } | |
40923b20 DP |
836 | if (dump_file && (dump_flags & TDF_DETAILS)) |
837 | fprintf (dump_file, "tree could trap...\n"); | |
838 | return false; | |
839 | } | |
840 | ||
bd544141 SP |
841 | bb = gimple_bb (stmt); |
842 | ||
726a989a | 843 | if (TREE_CODE (lhs) != SSA_NAME |
bd544141 SP |
844 | && bb != bb->loop_father->header |
845 | && !bb_with_exit_edge_p (bb->loop_father, bb)) | |
40923b20 | 846 | { |
5ce9450f JJ |
847 | if (ifcvt_can_use_mask_load_store (stmt)) |
848 | { | |
849 | gimple_set_plf (stmt, GF_PLF_2, true); | |
850 | *any_mask_load_store = true; | |
851 | return true; | |
852 | } | |
40923b20 DP |
853 | if (dump_file && (dump_flags & TDF_DETAILS)) |
854 | { | |
855 | fprintf (dump_file, "LHS is not var\n"); | |
726a989a | 856 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); |
40923b20 DP |
857 | } |
858 | return false; | |
859 | } | |
860 | ||
40923b20 DP |
861 | return true; |
862 | } | |
863 | ||
98c07c54 SP |
864 | /* Return true when STMT is if-convertible. |
865 | ||
866 | A statement is if-convertible if: | |
d47657bd | 867 | - it is an if-convertible GIMPLE_ASSIGN, |
bd544141 | 868 | - it is a GIMPLE_LABEL or a GIMPLE_COND. */ |
40923b20 DP |
869 | |
870 | static bool | |
5ce9450f JJ |
871 | if_convertible_stmt_p (gimple stmt, vec<data_reference_p> refs, |
872 | bool *any_mask_load_store) | |
40923b20 | 873 | { |
726a989a | 874 | switch (gimple_code (stmt)) |
40923b20 | 875 | { |
726a989a | 876 | case GIMPLE_LABEL: |
b5b8b0ac | 877 | case GIMPLE_DEBUG: |
98c07c54 SP |
878 | case GIMPLE_COND: |
879 | return true; | |
61b5f210 | 880 | |
b5b8b0ac | 881 | case GIMPLE_ASSIGN: |
5ce9450f JJ |
882 | return if_convertible_gimple_assign_stmt_p (stmt, refs, |
883 | any_mask_load_store); | |
61b5f210 | 884 | |
d7978bff RG |
885 | case GIMPLE_CALL: |
886 | { | |
887 | tree fndecl = gimple_call_fndecl (stmt); | |
888 | if (fndecl) | |
889 | { | |
890 | int flags = gimple_call_flags (stmt); | |
891 | if ((flags & ECF_CONST) | |
892 | && !(flags & ECF_LOOPING_CONST_OR_PURE) | |
893 | /* We can only vectorize some builtins at the moment, | |
894 | so restrict if-conversion to those. */ | |
895 | && DECL_BUILT_IN (fndecl)) | |
896 | return true; | |
897 | } | |
898 | return false; | |
899 | } | |
900 | ||
40923b20 DP |
901 | default: |
902 | /* Don't know what to do with 'em so don't do anything. */ | |
903 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
904 | { | |
905 | fprintf (dump_file, "don't know what to do\n"); | |
726a989a | 906 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); |
40923b20 DP |
907 | } |
908 | return false; | |
909 | break; | |
910 | } | |
911 | ||
912 | return true; | |
913 | } | |
914 | ||
98c07c54 SP |
915 | /* Return true when BB is if-convertible. This routine does not check |
916 | basic block's statements and phis. | |
917 | ||
918 | A basic block is not if-convertible if: | |
919 | - it is non-empty and it is after the exit block (in BFS order), | |
920 | - it is after the exit block but before the latch, | |
921 | - its edges are not normal. | |
922 | ||
923 | EXIT_BB is the basic block containing the exit of the LOOP. BB is | |
924 | inside LOOP. */ | |
40923b20 | 925 | |
61b5f210 | 926 | static bool |
3d91803a | 927 | if_convertible_bb_p (struct loop *loop, basic_block bb, basic_block exit_bb) |
40923b20 DP |
928 | { |
929 | edge e; | |
628f6a4e | 930 | edge_iterator ei; |
40923b20 DP |
931 | |
932 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
933 | fprintf (dump_file, "----------[%d]-------------\n", bb->index); | |
61b5f210 | 934 | |
bc447143 SP |
935 | if (EDGE_COUNT (bb->preds) > 2 |
936 | || EDGE_COUNT (bb->succs) > 2) | |
937 | return false; | |
938 | ||
3d91803a | 939 | if (exit_bb) |
40923b20 DP |
940 | { |
941 | if (bb != loop->latch) | |
942 | { | |
943 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
944 | fprintf (dump_file, "basic block after exit bb but before latch\n"); | |
945 | return false; | |
946 | } | |
947 | else if (!empty_block_p (bb)) | |
948 | { | |
baaa8e96 SP |
949 | if (dump_file && (dump_flags & TDF_DETAILS)) |
950 | fprintf (dump_file, "non empty basic block after exit bb\n"); | |
951 | return false; | |
952 | } | |
953 | else if (bb == loop->latch | |
954 | && bb != exit_bb | |
955 | && !dominated_by_p (CDI_DOMINATORS, bb, exit_bb)) | |
956 | { | |
957 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
958 | fprintf (dump_file, "latch is not dominated by exit_block\n"); | |
959 | return false; | |
960 | } | |
961 | } | |
962 | ||
963 | /* Be less adventurous and handle only normal edges. */ | |
964 | FOR_EACH_EDGE (e, ei, bb->succs) | |
a315c44c | 965 | if (e->flags & (EDGE_EH | EDGE_ABNORMAL | EDGE_IRREDUCIBLE_LOOP)) |
baaa8e96 SP |
966 | { |
967 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
98c07c54 | 968 | fprintf (dump_file, "Difficult to handle edges\n"); |
baaa8e96 SP |
969 | return false; |
970 | } | |
971 | ||
4ded8276 RB |
972 | /* At least one incoming edge has to be non-critical as otherwise edge |
973 | predicates are not equal to basic-block predicates of the edge | |
974 | source. */ | |
975 | if (EDGE_COUNT (bb->preds) > 1 | |
976 | && bb != loop->header) | |
977 | { | |
978 | bool found = false; | |
979 | FOR_EACH_EDGE (e, ei, bb->preds) | |
980 | if (EDGE_COUNT (e->src->succs) == 1) | |
981 | found = true; | |
982 | if (!found) | |
983 | { | |
984 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
985 | fprintf (dump_file, "only critical predecessors\n"); | |
986 | return false; | |
987 | } | |
988 | } | |
db963b52 | 989 | |
baaa8e96 SP |
990 | return true; |
991 | } | |
992 | ||
98c07c54 SP |
993 | /* Return true when all predecessor blocks of BB are visited. The |
994 | VISITED bitmap keeps track of the visited blocks. */ | |
baaa8e96 SP |
995 | |
996 | static bool | |
997 | pred_blocks_visited_p (basic_block bb, bitmap *visited) | |
998 | { | |
999 | edge e; | |
1000 | edge_iterator ei; | |
1001 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1002 | if (!bitmap_bit_p (*visited, e->src->index)) | |
1003 | return false; | |
1004 | ||
1005 | return true; | |
1006 | } | |
1007 | ||
1008 | /* Get body of a LOOP in suitable order for if-conversion. It is | |
1009 | caller's responsibility to deallocate basic block list. | |
1010 | If-conversion suitable order is, breadth first sort (BFS) order | |
1011 | with an additional constraint: select a block only if all its | |
1012 | predecessors are already selected. */ | |
1013 | ||
1014 | static basic_block * | |
1015 | get_loop_body_in_if_conv_order (const struct loop *loop) | |
1016 | { | |
1017 | basic_block *blocks, *blocks_in_bfs_order; | |
1018 | basic_block bb; | |
1019 | bitmap visited; | |
1020 | unsigned int index = 0; | |
1021 | unsigned int visited_count = 0; | |
1022 | ||
1023 | gcc_assert (loop->num_nodes); | |
fefa31b5 | 1024 | gcc_assert (loop->latch != EXIT_BLOCK_PTR_FOR_FN (cfun)); |
baaa8e96 SP |
1025 | |
1026 | blocks = XCNEWVEC (basic_block, loop->num_nodes); | |
1027 | visited = BITMAP_ALLOC (NULL); | |
1028 | ||
1029 | blocks_in_bfs_order = get_loop_body_in_bfs_order (loop); | |
1030 | ||
1031 | index = 0; | |
1032 | while (index < loop->num_nodes) | |
1033 | { | |
1034 | bb = blocks_in_bfs_order [index]; | |
1035 | ||
1036 | if (bb->flags & BB_IRREDUCIBLE_LOOP) | |
1037 | { | |
1038 | free (blocks_in_bfs_order); | |
1039 | BITMAP_FREE (visited); | |
1040 | free (blocks); | |
1041 | return NULL; | |
1042 | } | |
1043 | ||
1044 | if (!bitmap_bit_p (visited, bb->index)) | |
1045 | { | |
1046 | if (pred_blocks_visited_p (bb, &visited) | |
1047 | || bb == loop->header) | |
1048 | { | |
1049 | /* This block is now visited. */ | |
1050 | bitmap_set_bit (visited, bb->index); | |
1051 | blocks[visited_count++] = bb; | |
1052 | } | |
40923b20 | 1053 | } |
61b5f210 | 1054 | |
baaa8e96 | 1055 | index++; |
40923b20 | 1056 | |
baaa8e96 SP |
1057 | if (index == loop->num_nodes |
1058 | && visited_count != loop->num_nodes) | |
1059 | /* Not done yet. */ | |
1060 | index = 0; | |
1061 | } | |
1062 | free (blocks_in_bfs_order); | |
1063 | BITMAP_FREE (visited); | |
1064 | return blocks; | |
40923b20 DP |
1065 | } |
1066 | ||
e1449456 SP |
1067 | /* Returns true when the analysis of the predicates for all the basic |
1068 | blocks in LOOP succeeded. | |
1069 | ||
7b14477e | 1070 | predicate_bbs first allocates the predicates of the basic blocks. |
32ccbfac SP |
1071 | These fields are then initialized with the tree expressions |
1072 | representing the predicates under which a basic block is executed | |
1073 | in the LOOP. As the loop->header is executed at each iteration, it | |
1074 | has the "true" predicate. Other statements executed under a | |
1075 | condition are predicated with that condition, for example | |
e1449456 SP |
1076 | |
1077 | | if (x) | |
1078 | | S1; | |
1079 | | else | |
1080 | | S2; | |
1081 | ||
5521cae9 SP |
1082 | S1 will be predicated with "x", and |
1083 | S2 will be predicated with "!x". */ | |
e1449456 | 1084 | |
5ce9450f | 1085 | static void |
e1449456 SP |
1086 | predicate_bbs (loop_p loop) |
1087 | { | |
1088 | unsigned int i; | |
1089 | ||
1090 | for (i = 0; i < loop->num_nodes; i++) | |
7b14477e | 1091 | init_bb_predicate (ifc_bbs[i]); |
e1449456 SP |
1092 | |
1093 | for (i = 0; i < loop->num_nodes; i++) | |
1094 | { | |
7b14477e SP |
1095 | basic_block bb = ifc_bbs[i]; |
1096 | tree cond; | |
5ce9450f | 1097 | gimple stmt; |
e1449456 | 1098 | |
7b14477e SP |
1099 | /* The loop latch is always executed and has no extra conditions |
1100 | to be processed: skip it. */ | |
1101 | if (bb == loop->latch) | |
1102 | { | |
29caa68a | 1103 | reset_bb_predicate (loop->latch); |
7b14477e SP |
1104 | continue; |
1105 | } | |
1106 | ||
1107 | cond = bb_predicate (bb); | |
5ce9450f JJ |
1108 | stmt = last_stmt (bb); |
1109 | if (stmt && gimple_code (stmt) == GIMPLE_COND) | |
e1449456 | 1110 | { |
5ce9450f JJ |
1111 | tree c2; |
1112 | edge true_edge, false_edge; | |
1113 | location_t loc = gimple_location (stmt); | |
1114 | tree c = fold_build2_loc (loc, gimple_cond_code (stmt), | |
1115 | boolean_type_node, | |
1116 | gimple_cond_lhs (stmt), | |
1117 | gimple_cond_rhs (stmt)); | |
1118 | ||
1119 | /* Add new condition into destination's predicate list. */ | |
1120 | extract_true_false_edges_from_block (gimple_bb (stmt), | |
1121 | &true_edge, &false_edge); | |
1122 | ||
1123 | /* If C is true, then TRUE_EDGE is taken. */ | |
1124 | add_to_dst_predicate_list (loop, true_edge, unshare_expr (cond), | |
1125 | unshare_expr (c)); | |
1126 | ||
1127 | /* If C is false, then FALSE_EDGE is taken. */ | |
1128 | c2 = build1_loc (loc, TRUTH_NOT_EXPR, boolean_type_node, | |
1129 | unshare_expr (c)); | |
1130 | add_to_dst_predicate_list (loop, false_edge, | |
1131 | unshare_expr (cond), c2); | |
1132 | ||
1133 | cond = NULL_TREE; | |
e1449456 SP |
1134 | } |
1135 | ||
1136 | /* If current bb has only one successor, then consider it as an | |
1137 | unconditional goto. */ | |
1138 | if (single_succ_p (bb)) | |
1139 | { | |
1140 | basic_block bb_n = single_succ (bb); | |
1141 | ||
1142 | /* The successor bb inherits the predicate of its | |
1143 | predecessor. If there is no predicate in the predecessor | |
1144 | bb, then consider the successor bb as always executed. */ | |
1145 | if (cond == NULL_TREE) | |
1146 | cond = boolean_true_node; | |
1147 | ||
5ce9450f | 1148 | add_to_predicate_list (loop, bb_n, cond); |
e1449456 SP |
1149 | } |
1150 | } | |
1151 | ||
1152 | /* The loop header is always executed. */ | |
29caa68a | 1153 | reset_bb_predicate (loop->header); |
7b14477e SP |
1154 | gcc_assert (bb_predicate_gimplified_stmts (loop->header) == NULL |
1155 | && bb_predicate_gimplified_stmts (loop->latch) == NULL); | |
e1449456 SP |
1156 | } |
1157 | ||
e1fd038a SP |
1158 | /* Return true when LOOP is if-convertible. This is a helper function |
1159 | for if_convertible_loop_p. REFS and DDRS are initialized and freed | |
1160 | in if_convertible_loop_p. */ | |
40923b20 DP |
1161 | |
1162 | static bool | |
e1fd038a | 1163 | if_convertible_loop_p_1 (struct loop *loop, |
9771b263 DN |
1164 | vec<loop_p> *loop_nest, |
1165 | vec<data_reference_p> *refs, | |
5ce9450f | 1166 | vec<ddr_p> *ddrs, bool *any_mask_load_store) |
40923b20 | 1167 | { |
e1fd038a | 1168 | bool res; |
40923b20 | 1169 | unsigned int i; |
3d91803a | 1170 | basic_block exit_bb = NULL; |
40923b20 | 1171 | |
6d795034 SP |
1172 | /* Don't if-convert the loop when the data dependences cannot be |
1173 | computed: the loop won't be vectorized in that case. */ | |
01be8516 | 1174 | res = compute_data_dependences_for_loop (loop, true, loop_nest, refs, ddrs); |
e1fd038a SP |
1175 | if (!res) |
1176 | return false; | |
6d795034 | 1177 | |
40923b20 | 1178 | calculate_dominance_info (CDI_DOMINATORS); |
40923b20 DP |
1179 | |
1180 | /* Allow statements that can be handled during if-conversion. */ | |
1181 | ifc_bbs = get_loop_body_in_if_conv_order (loop); | |
1182 | if (!ifc_bbs) | |
1183 | { | |
1184 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
4ab71973 | 1185 | fprintf (dump_file, "Irreducible loop\n"); |
40923b20 DP |
1186 | return false; |
1187 | } | |
61b5f210 | 1188 | |
40923b20 DP |
1189 | for (i = 0; i < loop->num_nodes; i++) |
1190 | { | |
e1449456 | 1191 | basic_block bb = ifc_bbs[i]; |
40923b20 | 1192 | |
3d91803a | 1193 | if (!if_convertible_bb_p (loop, bb, exit_bb)) |
40923b20 DP |
1194 | return false; |
1195 | ||
e1449456 SP |
1196 | if (bb_with_exit_edge_p (loop, bb)) |
1197 | exit_bb = bb; | |
1198 | } | |
1199 | ||
5ce9450f JJ |
1200 | for (i = 0; i < loop->num_nodes; i++) |
1201 | { | |
1202 | basic_block bb = ifc_bbs[i]; | |
1203 | gimple_stmt_iterator gsi; | |
1204 | ||
1205 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
1206 | switch (gimple_code (gsi_stmt (gsi))) | |
1207 | { | |
1208 | case GIMPLE_LABEL: | |
1209 | case GIMPLE_ASSIGN: | |
1210 | case GIMPLE_CALL: | |
1211 | case GIMPLE_DEBUG: | |
1212 | case GIMPLE_COND: | |
1213 | break; | |
1214 | default: | |
1215 | return false; | |
1216 | } | |
1217 | } | |
e1449456 | 1218 | |
4b9c23ea SP |
1219 | if (flag_tree_loop_if_convert_stores) |
1220 | { | |
1221 | data_reference_p dr; | |
1222 | ||
9771b263 | 1223 | for (i = 0; refs->iterate (i, &dr); i++) |
4b9c23ea SP |
1224 | { |
1225 | dr->aux = XNEW (struct ifc_dr); | |
1226 | DR_WRITTEN_AT_LEAST_ONCE (dr) = -1; | |
1227 | DR_RW_UNCONDITIONALLY (dr) = -1; | |
1228 | } | |
5ce9450f | 1229 | predicate_bbs (loop); |
4b9c23ea SP |
1230 | } |
1231 | ||
e1449456 SP |
1232 | for (i = 0; i < loop->num_nodes; i++) |
1233 | { | |
1234 | basic_block bb = ifc_bbs[i]; | |
1235 | gimple_stmt_iterator itr; | |
1236 | ||
e1fd038a | 1237 | /* Check the if-convertibility of statements in predicated BBs. */ |
5ce9450f | 1238 | if (!dominated_by_p (CDI_DOMINATORS, loop->latch, bb)) |
e1fd038a | 1239 | for (itr = gsi_start_bb (bb); !gsi_end_p (itr); gsi_next (&itr)) |
5ce9450f JJ |
1240 | if (!if_convertible_stmt_p (gsi_stmt (itr), *refs, |
1241 | any_mask_load_store)) | |
e1fd038a | 1242 | return false; |
40923b20 DP |
1243 | } |
1244 | ||
5ce9450f JJ |
1245 | if (flag_tree_loop_if_convert_stores) |
1246 | for (i = 0; i < loop->num_nodes; i++) | |
1247 | free_bb_predicate (ifc_bbs[i]); | |
1248 | ||
1249 | /* Checking PHIs needs to be done after stmts, as the fact whether there | |
1250 | are any masked loads or stores affects the tests. */ | |
1251 | for (i = 0; i < loop->num_nodes; i++) | |
1252 | { | |
1253 | basic_block bb = ifc_bbs[i]; | |
1254 | gimple_stmt_iterator itr; | |
1255 | ||
1256 | for (itr = gsi_start_phis (bb); !gsi_end_p (itr); gsi_next (&itr)) | |
1257 | if (!if_convertible_phi_p (loop, bb, gsi_stmt (itr), | |
1258 | *any_mask_load_store)) | |
1259 | return false; | |
1260 | } | |
1261 | ||
40923b20 | 1262 | if (dump_file) |
4ab71973 | 1263 | fprintf (dump_file, "Applying if-conversion\n"); |
40923b20 | 1264 | |
40923b20 DP |
1265 | return true; |
1266 | } | |
1267 | ||
e1fd038a SP |
1268 | /* Return true when LOOP is if-convertible. |
1269 | LOOP is if-convertible if: | |
1270 | - it is innermost, | |
1271 | - it has two or more basic blocks, | |
1272 | - it has only one exit, | |
1273 | - loop header is not the exit edge, | |
1274 | - if its basic blocks and phi nodes are if convertible. */ | |
1275 | ||
1276 | static bool | |
5ce9450f | 1277 | if_convertible_loop_p (struct loop *loop, bool *any_mask_load_store) |
e1fd038a SP |
1278 | { |
1279 | edge e; | |
1280 | edge_iterator ei; | |
1281 | bool res = false; | |
9771b263 DN |
1282 | vec<data_reference_p> refs; |
1283 | vec<ddr_p> ddrs; | |
e1fd038a SP |
1284 | |
1285 | /* Handle only innermost loop. */ | |
1286 | if (!loop || loop->inner) | |
1287 | { | |
1288 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1289 | fprintf (dump_file, "not innermost loop\n"); | |
1290 | return false; | |
1291 | } | |
1292 | ||
1293 | /* If only one block, no need for if-conversion. */ | |
1294 | if (loop->num_nodes <= 2) | |
1295 | { | |
1296 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1297 | fprintf (dump_file, "less than 2 basic blocks\n"); | |
1298 | return false; | |
1299 | } | |
1300 | ||
1301 | /* More than one loop exit is too much to handle. */ | |
1302 | if (!single_exit (loop)) | |
1303 | { | |
1304 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1305 | fprintf (dump_file, "multiple exits\n"); | |
1306 | return false; | |
1307 | } | |
1308 | ||
1309 | /* If one of the loop header's edge is an exit edge then do not | |
1310 | apply if-conversion. */ | |
1311 | FOR_EACH_EDGE (e, ei, loop->header->succs) | |
1312 | if (loop_exit_edge_p (loop, e)) | |
1313 | return false; | |
1314 | ||
9771b263 DN |
1315 | refs.create (5); |
1316 | ddrs.create (25); | |
00f96dc9 | 1317 | auto_vec<loop_p, 3> loop_nest; |
5ce9450f JJ |
1318 | res = if_convertible_loop_p_1 (loop, &loop_nest, &refs, &ddrs, |
1319 | any_mask_load_store); | |
e1fd038a | 1320 | |
4b9c23ea SP |
1321 | if (flag_tree_loop_if_convert_stores) |
1322 | { | |
1323 | data_reference_p dr; | |
1324 | unsigned int i; | |
1325 | ||
9771b263 | 1326 | for (i = 0; refs.iterate (i, &dr); i++) |
4b9c23ea SP |
1327 | free (dr->aux); |
1328 | } | |
1329 | ||
e1fd038a SP |
1330 | free_data_refs (refs); |
1331 | free_dependence_relations (ddrs); | |
1332 | return res; | |
1333 | } | |
1334 | ||
7b14477e SP |
1335 | /* Basic block BB has two predecessors. Using predecessor's bb |
1336 | predicate, set an appropriate condition COND for the PHI node | |
1337 | replacement. Return the true block whose phi arguments are | |
1338 | selected when cond is true. LOOP is the loop containing the | |
1339 | if-converted region, GSI is the place to insert the code for the | |
1340 | if-conversion. */ | |
40923b20 | 1341 | |
7f7e0703 | 1342 | static basic_block |
4ded8276 | 1343 | find_phi_replacement_condition (basic_block bb, tree *cond, |
bd544141 | 1344 | gimple_stmt_iterator *gsi) |
40923b20 | 1345 | { |
8ad02175 | 1346 | edge first_edge, second_edge; |
c6540bde | 1347 | tree tmp_cond; |
40923b20 | 1348 | |
1c280337 | 1349 | gcc_assert (EDGE_COUNT (bb->preds) == 2); |
8ad02175 UB |
1350 | first_edge = EDGE_PRED (bb, 0); |
1351 | second_edge = EDGE_PRED (bb, 1); | |
40923b20 | 1352 | |
4ded8276 RB |
1353 | /* Prefer an edge with a not negated predicate. |
1354 | ??? That's a very weak cost model. */ | |
7b14477e | 1355 | tmp_cond = bb_predicate (first_edge->src); |
77bd31de | 1356 | gcc_assert (tmp_cond); |
40923b20 DP |
1357 | if (TREE_CODE (tmp_cond) == TRUTH_NOT_EXPR) |
1358 | { | |
8ad02175 UB |
1359 | edge tmp_edge; |
1360 | ||
1361 | tmp_edge = first_edge; | |
1362 | first_edge = second_edge; | |
1363 | second_edge = tmp_edge; | |
40923b20 | 1364 | } |
1c280337 | 1365 | |
4ded8276 RB |
1366 | /* Check if the edge we take the condition from is not critical. |
1367 | We know that at least one non-critical edge exists. */ | |
1368 | if (EDGE_COUNT (first_edge->src->succs) > 1) | |
40923b20 | 1369 | { |
7b14477e | 1370 | *cond = bb_predicate (second_edge->src); |
8ad02175 | 1371 | |
8ad02175 | 1372 | if (TREE_CODE (*cond) == TRUTH_NOT_EXPR) |
747633c5 | 1373 | *cond = TREE_OPERAND (*cond, 0); |
0bca51f0 | 1374 | else |
8ad02175 UB |
1375 | /* Select non loop header bb. */ |
1376 | first_edge = second_edge; | |
40923b20 | 1377 | } |
1c280337 | 1378 | else |
7b14477e | 1379 | *cond = bb_predicate (first_edge->src); |
61b5f210 | 1380 | |
747633c5 RG |
1381 | /* Gimplify the condition to a valid cond-expr conditonal operand. */ |
1382 | *cond = force_gimple_operand_gsi_1 (gsi, unshare_expr (*cond), | |
1383 | is_gimple_condexpr, NULL_TREE, | |
1384 | true, GSI_SAME_STMT); | |
40923b20 | 1385 | |
8ad02175 | 1386 | return first_edge->src; |
40923b20 DP |
1387 | } |
1388 | ||
bd544141 SP |
1389 | /* Replace a scalar PHI node with a COND_EXPR using COND as condition. |
1390 | This routine does not handle PHI nodes with more than two | |
1391 | arguments. | |
40923b20 | 1392 | |
40923b20 | 1393 | For example, |
b8f4632c | 1394 | S1: A = PHI <x1(1), x2(5)> |
40923b20 DP |
1395 | is converted into, |
1396 | S2: A = cond ? x1 : x2; | |
98c07c54 SP |
1397 | |
1398 | The generated code is inserted at GSI that points to the top of | |
1399 | basic block's statement list. When COND is true, phi arg from | |
1400 | TRUE_BB is selected. */ | |
40923b20 DP |
1401 | |
1402 | static void | |
bd544141 SP |
1403 | predicate_scalar_phi (gimple phi, tree cond, |
1404 | basic_block true_bb, | |
1405 | gimple_stmt_iterator *gsi) | |
40923b20 | 1406 | { |
726a989a | 1407 | gimple new_stmt; |
40923b20 | 1408 | basic_block bb; |
e639b206 | 1409 | tree rhs, res, arg, scev; |
40923b20 | 1410 | |
98c07c54 SP |
1411 | gcc_assert (gimple_code (phi) == GIMPLE_PHI |
1412 | && gimple_phi_num_args (phi) == 2); | |
b8698a0f | 1413 | |
bd544141 SP |
1414 | res = gimple_phi_result (phi); |
1415 | /* Do not handle virtual phi nodes. */ | |
ea057359 | 1416 | if (virtual_operand_p (res)) |
bd544141 SP |
1417 | return; |
1418 | ||
726a989a | 1419 | bb = gimple_bb (phi); |
40923b20 | 1420 | |
e639b206 SP |
1421 | if ((arg = degenerate_phi_result (phi)) |
1422 | || ((scev = analyze_scalar_evolution (gimple_bb (phi)->loop_father, | |
1423 | res)) | |
1424 | && !chrec_contains_undetermined (scev) | |
1425 | && scev != res | |
1426 | && (arg = gimple_phi_arg_def (phi, 0)))) | |
e7cb8957 | 1427 | rhs = arg; |
40923b20 DP |
1428 | else |
1429 | { | |
e7cb8957 SP |
1430 | tree arg_0, arg_1; |
1431 | /* Use condition that is not TRUTH_NOT_EXPR in conditional modify expr. */ | |
1432 | if (EDGE_PRED (bb, 1)->src == true_bb) | |
1433 | { | |
1434 | arg_0 = gimple_phi_arg_def (phi, 1); | |
1435 | arg_1 = gimple_phi_arg_def (phi, 0); | |
1436 | } | |
1437 | else | |
1438 | { | |
1439 | arg_0 = gimple_phi_arg_def (phi, 0); | |
1440 | arg_1 = gimple_phi_arg_def (phi, 1); | |
1441 | } | |
40923b20 | 1442 | |
e7cb8957 | 1443 | /* Build new RHS using selected condition and arguments. */ |
f35613b2 AP |
1444 | rhs = fold_build_cond_expr (TREE_TYPE (res), unshare_expr (cond), |
1445 | arg_0, arg_1); | |
e7cb8957 | 1446 | } |
40923b20 | 1447 | |
bd544141 | 1448 | new_stmt = gimple_build_assign (res, rhs); |
726a989a | 1449 | gsi_insert_before (gsi, new_stmt, GSI_SAME_STMT); |
f430bae8 | 1450 | update_stmt (new_stmt); |
40923b20 DP |
1451 | |
1452 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1453 | { | |
1454 | fprintf (dump_file, "new phi replacement stmt\n"); | |
726a989a | 1455 | print_gimple_stmt (dump_file, new_stmt, 0, TDF_SLIM); |
40923b20 DP |
1456 | } |
1457 | } | |
1458 | ||
bd544141 | 1459 | /* Replaces in LOOP all the scalar phi nodes other than those in the |
7b14477e | 1460 | LOOP->header block with conditional modify expressions. */ |
40923b20 DP |
1461 | |
1462 | static void | |
bd544141 | 1463 | predicate_all_scalar_phis (struct loop *loop) |
40923b20 DP |
1464 | { |
1465 | basic_block bb; | |
1466 | unsigned int orig_loop_num_nodes = loop->num_nodes; | |
1467 | unsigned int i; | |
1468 | ||
40923b20 DP |
1469 | for (i = 1; i < orig_loop_num_nodes; i++) |
1470 | { | |
726a989a RB |
1471 | gimple phi; |
1472 | tree cond = NULL_TREE; | |
1473 | gimple_stmt_iterator gsi, phi_gsi; | |
7f7e0703 | 1474 | basic_block true_bb = NULL; |
40923b20 | 1475 | bb = ifc_bbs[i]; |
61b5f210 | 1476 | |
0ecf0d5f | 1477 | if (bb == loop->header) |
40923b20 DP |
1478 | continue; |
1479 | ||
726a989a | 1480 | phi_gsi = gsi_start_phis (bb); |
7b14477e SP |
1481 | if (gsi_end_p (phi_gsi)) |
1482 | continue; | |
40923b20 | 1483 | |
62ef2431 | 1484 | /* BB has two predecessors. Using predecessor's aux field, set |
40923b20 | 1485 | appropriate condition for the PHI node replacement. */ |
7b14477e | 1486 | gsi = gsi_after_labels (bb); |
4ded8276 | 1487 | true_bb = find_phi_replacement_condition (bb, &cond, &gsi); |
40923b20 | 1488 | |
726a989a | 1489 | while (!gsi_end_p (phi_gsi)) |
40923b20 | 1490 | { |
726a989a | 1491 | phi = gsi_stmt (phi_gsi); |
bd544141 | 1492 | predicate_scalar_phi (phi, cond, true_bb, &gsi); |
40923b20 | 1493 | release_phi_node (phi); |
726a989a | 1494 | gsi_next (&phi_gsi); |
40923b20 | 1495 | } |
7b14477e | 1496 | |
726a989a | 1497 | set_phi_nodes (bb, NULL); |
40923b20 | 1498 | } |
40923b20 DP |
1499 | } |
1500 | ||
7b14477e SP |
1501 | /* Insert in each basic block of LOOP the statements produced by the |
1502 | gimplification of the predicates. */ | |
1503 | ||
1504 | static void | |
5ce9450f | 1505 | insert_gimplified_predicates (loop_p loop, bool any_mask_load_store) |
7b14477e SP |
1506 | { |
1507 | unsigned int i; | |
1508 | ||
1509 | for (i = 0; i < loop->num_nodes; i++) | |
1510 | { | |
1511 | basic_block bb = ifc_bbs[i]; | |
bd544141 | 1512 | gimple_seq stmts; |
7b14477e | 1513 | |
5c8b27d7 SP |
1514 | if (!is_predicated (bb)) |
1515 | { | |
1516 | /* Do not insert statements for a basic block that is not | |
1517 | predicated. Also make sure that the predicate of the | |
1518 | basic block is set to true. */ | |
1519 | reset_bb_predicate (bb); | |
1520 | continue; | |
1521 | } | |
1522 | ||
bd544141 | 1523 | stmts = bb_predicate_gimplified_stmts (bb); |
7b14477e SP |
1524 | if (stmts) |
1525 | { | |
5ce9450f JJ |
1526 | if (flag_tree_loop_if_convert_stores |
1527 | || any_mask_load_store) | |
bd544141 SP |
1528 | { |
1529 | /* Insert the predicate of the BB just after the label, | |
1530 | as the if-conversion of memory writes will use this | |
1531 | predicate. */ | |
1532 | gimple_stmt_iterator gsi = gsi_after_labels (bb); | |
1533 | gsi_insert_seq_before (&gsi, stmts, GSI_SAME_STMT); | |
1534 | } | |
7b14477e | 1535 | else |
bd544141 SP |
1536 | { |
1537 | /* Insert the predicate of the BB at the end of the BB | |
1538 | as this would reduce the register pressure: the only | |
1539 | use of this predicate will be in successor BBs. */ | |
1540 | gimple_stmt_iterator gsi = gsi_last_bb (bb); | |
1541 | ||
1542 | if (gsi_end_p (gsi) | |
1543 | || stmt_ends_bb_p (gsi_stmt (gsi))) | |
1544 | gsi_insert_seq_before (&gsi, stmts, GSI_SAME_STMT); | |
1545 | else | |
1546 | gsi_insert_seq_after (&gsi, stmts, GSI_SAME_STMT); | |
1547 | } | |
7b14477e SP |
1548 | |
1549 | /* Once the sequence is code generated, set it to NULL. */ | |
1550 | set_bb_predicate_gimplified_stmts (bb, NULL); | |
1551 | } | |
1552 | } | |
1553 | } | |
1554 | ||
bd544141 SP |
1555 | /* Predicate each write to memory in LOOP. |
1556 | ||
1557 | This function transforms control flow constructs containing memory | |
1558 | writes of the form: | |
1559 | ||
1560 | | for (i = 0; i < N; i++) | |
1561 | | if (cond) | |
1562 | | A[i] = expr; | |
1563 | ||
1564 | into the following form that does not contain control flow: | |
1565 | ||
1566 | | for (i = 0; i < N; i++) | |
1567 | | A[i] = cond ? expr : A[i]; | |
1568 | ||
1569 | The original CFG looks like this: | |
1570 | ||
1571 | | bb_0 | |
1572 | | i = 0 | |
1573 | | end_bb_0 | |
1574 | | | |
1575 | | bb_1 | |
1576 | | if (i < N) goto bb_5 else goto bb_2 | |
1577 | | end_bb_1 | |
1578 | | | |
1579 | | bb_2 | |
1580 | | cond = some_computation; | |
1581 | | if (cond) goto bb_3 else goto bb_4 | |
1582 | | end_bb_2 | |
1583 | | | |
1584 | | bb_3 | |
1585 | | A[i] = expr; | |
1586 | | goto bb_4 | |
1587 | | end_bb_3 | |
1588 | | | |
1589 | | bb_4 | |
1590 | | goto bb_1 | |
1591 | | end_bb_4 | |
1592 | ||
1593 | insert_gimplified_predicates inserts the computation of the COND | |
1594 | expression at the beginning of the destination basic block: | |
1595 | ||
1596 | | bb_0 | |
1597 | | i = 0 | |
1598 | | end_bb_0 | |
1599 | | | |
1600 | | bb_1 | |
1601 | | if (i < N) goto bb_5 else goto bb_2 | |
1602 | | end_bb_1 | |
1603 | | | |
1604 | | bb_2 | |
1605 | | cond = some_computation; | |
1606 | | if (cond) goto bb_3 else goto bb_4 | |
1607 | | end_bb_2 | |
1608 | | | |
1609 | | bb_3 | |
1610 | | cond = some_computation; | |
1611 | | A[i] = expr; | |
1612 | | goto bb_4 | |
1613 | | end_bb_3 | |
1614 | | | |
1615 | | bb_4 | |
1616 | | goto bb_1 | |
1617 | | end_bb_4 | |
1618 | ||
1619 | predicate_mem_writes is then predicating the memory write as follows: | |
1620 | ||
1621 | | bb_0 | |
1622 | | i = 0 | |
1623 | | end_bb_0 | |
1624 | | | |
1625 | | bb_1 | |
1626 | | if (i < N) goto bb_5 else goto bb_2 | |
1627 | | end_bb_1 | |
1628 | | | |
1629 | | bb_2 | |
1630 | | if (cond) goto bb_3 else goto bb_4 | |
1631 | | end_bb_2 | |
1632 | | | |
1633 | | bb_3 | |
1634 | | cond = some_computation; | |
1635 | | A[i] = cond ? expr : A[i]; | |
1636 | | goto bb_4 | |
1637 | | end_bb_3 | |
1638 | | | |
1639 | | bb_4 | |
1640 | | goto bb_1 | |
1641 | | end_bb_4 | |
1642 | ||
1643 | and finally combine_blocks removes the basic block boundaries making | |
1644 | the loop vectorizable: | |
1645 | ||
1646 | | bb_0 | |
1647 | | i = 0 | |
1648 | | if (i < N) goto bb_5 else goto bb_1 | |
1649 | | end_bb_0 | |
1650 | | | |
1651 | | bb_1 | |
1652 | | cond = some_computation; | |
1653 | | A[i] = cond ? expr : A[i]; | |
1654 | | if (i < N) goto bb_5 else goto bb_4 | |
1655 | | end_bb_1 | |
1656 | | | |
1657 | | bb_4 | |
1658 | | goto bb_1 | |
1659 | | end_bb_4 | |
1660 | */ | |
1661 | ||
1662 | static void | |
1663 | predicate_mem_writes (loop_p loop) | |
1664 | { | |
1665 | unsigned int i, orig_loop_num_nodes = loop->num_nodes; | |
1666 | ||
1667 | for (i = 1; i < orig_loop_num_nodes; i++) | |
1668 | { | |
1669 | gimple_stmt_iterator gsi; | |
1670 | basic_block bb = ifc_bbs[i]; | |
1671 | tree cond = bb_predicate (bb); | |
95df37bf | 1672 | bool swap; |
bd544141 SP |
1673 | gimple stmt; |
1674 | ||
1675 | if (is_true_predicate (cond)) | |
1676 | continue; | |
1677 | ||
95df37bf RG |
1678 | swap = false; |
1679 | if (TREE_CODE (cond) == TRUTH_NOT_EXPR) | |
1680 | { | |
1681 | swap = true; | |
1682 | cond = TREE_OPERAND (cond, 0); | |
1683 | } | |
1684 | ||
bd544141 | 1685 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
5ce9450f JJ |
1686 | if (!gimple_assign_single_p (stmt = gsi_stmt (gsi))) |
1687 | continue; | |
1688 | else if (gimple_plf (stmt, GF_PLF_2)) | |
1689 | { | |
1690 | tree lhs = gimple_assign_lhs (stmt); | |
1691 | tree rhs = gimple_assign_rhs1 (stmt); | |
1692 | tree ref, addr, ptr, masktype, mask_op0, mask_op1, mask; | |
1693 | gimple new_stmt; | |
1694 | int bitsize = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (lhs))); | |
1695 | ||
1696 | masktype = build_nonstandard_integer_type (bitsize, 1); | |
1697 | mask_op0 = build_int_cst (masktype, swap ? 0 : -1); | |
1698 | mask_op1 = build_int_cst (masktype, swap ? -1 : 0); | |
1699 | ref = TREE_CODE (lhs) == SSA_NAME ? rhs : lhs; | |
1700 | mark_addressable (ref); | |
1701 | addr = force_gimple_operand_gsi (&gsi, build_fold_addr_expr (ref), | |
1702 | true, NULL_TREE, true, | |
1703 | GSI_SAME_STMT); | |
1704 | cond = force_gimple_operand_gsi_1 (&gsi, unshare_expr (cond), | |
1705 | is_gimple_condexpr, NULL_TREE, | |
1706 | true, GSI_SAME_STMT); | |
1707 | mask = fold_build_cond_expr (masktype, unshare_expr (cond), | |
1708 | mask_op0, mask_op1); | |
1709 | mask = ifc_temp_var (masktype, mask, &gsi); | |
1710 | ptr = build_int_cst (reference_alias_ptr_type (ref), 0); | |
1711 | /* Copy points-to info if possible. */ | |
1712 | if (TREE_CODE (addr) == SSA_NAME && !SSA_NAME_PTR_INFO (addr)) | |
1713 | copy_ref_info (build2 (MEM_REF, TREE_TYPE (ref), addr, ptr), | |
1714 | ref); | |
1715 | if (TREE_CODE (lhs) == SSA_NAME) | |
1716 | { | |
1717 | new_stmt | |
1718 | = gimple_build_call_internal (IFN_MASK_LOAD, 3, addr, | |
1719 | ptr, mask); | |
1720 | gimple_call_set_lhs (new_stmt, lhs); | |
1721 | } | |
1722 | else | |
1723 | new_stmt | |
1724 | = gimple_build_call_internal (IFN_MASK_STORE, 4, addr, ptr, | |
1725 | mask, rhs); | |
8e91d222 | 1726 | gsi_replace (&gsi, new_stmt, true); |
5ce9450f JJ |
1727 | } |
1728 | else if (gimple_vdef (stmt)) | |
bd544141 SP |
1729 | { |
1730 | tree lhs = gimple_assign_lhs (stmt); | |
1731 | tree rhs = gimple_assign_rhs1 (stmt); | |
1732 | tree type = TREE_TYPE (lhs); | |
1733 | ||
1734 | lhs = ifc_temp_var (type, unshare_expr (lhs), &gsi); | |
1735 | rhs = ifc_temp_var (type, unshare_expr (rhs), &gsi); | |
95df37bf RG |
1736 | if (swap) |
1737 | { | |
1738 | tree tem = lhs; | |
1739 | lhs = rhs; | |
1740 | rhs = tem; | |
1741 | } | |
1742 | cond = force_gimple_operand_gsi_1 (&gsi, unshare_expr (cond), | |
1743 | is_gimple_condexpr, NULL_TREE, | |
1744 | true, GSI_SAME_STMT); | |
f35613b2 | 1745 | rhs = fold_build_cond_expr (type, unshare_expr (cond), rhs, lhs); |
bd544141 SP |
1746 | gimple_assign_set_rhs1 (stmt, ifc_temp_var (type, rhs, &gsi)); |
1747 | update_stmt (stmt); | |
1748 | } | |
1749 | } | |
1750 | } | |
1751 | ||
76b84776 | 1752 | /* Remove all GIMPLE_CONDs and GIMPLE_LABELs of all the basic blocks |
718d3588 SP |
1753 | other than the exit and latch of the LOOP. Also resets the |
1754 | GIMPLE_DEBUG information. */ | |
76b84776 SP |
1755 | |
1756 | static void | |
1757 | remove_conditions_and_labels (loop_p loop) | |
1758 | { | |
1759 | gimple_stmt_iterator gsi; | |
1760 | unsigned int i; | |
1761 | ||
1762 | for (i = 0; i < loop->num_nodes; i++) | |
1763 | { | |
7b14477e | 1764 | basic_block bb = ifc_bbs[i]; |
76b84776 SP |
1765 | |
1766 | if (bb_with_exit_edge_p (loop, bb) | |
1767 | || bb == loop->latch) | |
1768 | continue; | |
1769 | ||
1770 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); ) | |
718d3588 SP |
1771 | switch (gimple_code (gsi_stmt (gsi))) |
1772 | { | |
1773 | case GIMPLE_COND: | |
1774 | case GIMPLE_LABEL: | |
1775 | gsi_remove (&gsi, true); | |
1776 | break; | |
1777 | ||
1778 | case GIMPLE_DEBUG: | |
1779 | /* ??? Should there be conditional GIMPLE_DEBUG_BINDs? */ | |
1780 | if (gimple_debug_bind_p (gsi_stmt (gsi))) | |
1781 | { | |
1782 | gimple_debug_bind_reset_value (gsi_stmt (gsi)); | |
1783 | update_stmt (gsi_stmt (gsi)); | |
1784 | } | |
1785 | gsi_next (&gsi); | |
1786 | break; | |
1787 | ||
1788 | default: | |
1789 | gsi_next (&gsi); | |
1790 | } | |
76b84776 SP |
1791 | } |
1792 | } | |
1793 | ||
62ef2431 SP |
1794 | /* Combine all the basic blocks from LOOP into one or two super basic |
1795 | blocks. Replace PHI nodes with conditional modify expressions. */ | |
40923b20 DP |
1796 | |
1797 | static void | |
5ce9450f | 1798 | combine_blocks (struct loop *loop, bool any_mask_load_store) |
40923b20 DP |
1799 | { |
1800 | basic_block bb, exit_bb, merge_target_bb; | |
1801 | unsigned int orig_loop_num_nodes = loop->num_nodes; | |
1802 | unsigned int i; | |
36b24193 ZD |
1803 | edge e; |
1804 | edge_iterator ei; | |
2b74282d | 1805 | |
5ce9450f | 1806 | predicate_bbs (loop); |
76b84776 | 1807 | remove_conditions_and_labels (loop); |
5ce9450f | 1808 | insert_gimplified_predicates (loop, any_mask_load_store); |
bd544141 SP |
1809 | predicate_all_scalar_phis (loop); |
1810 | ||
5ce9450f | 1811 | if (flag_tree_loop_if_convert_stores || any_mask_load_store) |
bd544141 | 1812 | predicate_mem_writes (loop); |
40923b20 | 1813 | |
98c07c54 SP |
1814 | /* Merge basic blocks: first remove all the edges in the loop, |
1815 | except for those from the exit block. */ | |
40923b20 | 1816 | exit_bb = NULL; |
36b24193 ZD |
1817 | for (i = 0; i < orig_loop_num_nodes; i++) |
1818 | { | |
1819 | bb = ifc_bbs[i]; | |
c2b5fc8d | 1820 | free_bb_predicate (bb); |
36b24193 ZD |
1821 | if (bb_with_exit_edge_p (loop, bb)) |
1822 | { | |
c6542175 | 1823 | gcc_assert (exit_bb == NULL); |
36b24193 | 1824 | exit_bb = bb; |
36b24193 ZD |
1825 | } |
1826 | } | |
1827 | gcc_assert (exit_bb != loop->latch); | |
40923b20 | 1828 | |
40923b20 DP |
1829 | for (i = 1; i < orig_loop_num_nodes; i++) |
1830 | { | |
40923b20 DP |
1831 | bb = ifc_bbs[i]; |
1832 | ||
36b24193 | 1833 | for (ei = ei_start (bb->preds); (e = ei_safe_edge (ei));) |
40923b20 | 1834 | { |
36b24193 ZD |
1835 | if (e->src == exit_bb) |
1836 | ei_next (&ei); | |
1837 | else | |
1838 | remove_edge (e); | |
1839 | } | |
1840 | } | |
40923b20 | 1841 | |
36b24193 ZD |
1842 | if (exit_bb != NULL) |
1843 | { | |
1844 | if (exit_bb != loop->header) | |
1845 | { | |
98c07c54 | 1846 | /* Connect this node to loop header. */ |
36b24193 ZD |
1847 | make_edge (loop->header, exit_bb, EDGE_FALLTHRU); |
1848 | set_immediate_dominator (CDI_DOMINATORS, exit_bb, loop->header); | |
40923b20 DP |
1849 | } |
1850 | ||
36b24193 ZD |
1851 | /* Redirect non-exit edges to loop->latch. */ |
1852 | FOR_EACH_EDGE (e, ei, exit_bb->succs) | |
1853 | { | |
1854 | if (!loop_exit_edge_p (loop, e)) | |
1855 | redirect_edge_and_branch (e, loop->latch); | |
1856 | } | |
1857 | set_immediate_dominator (CDI_DOMINATORS, loop->latch, exit_bb); | |
1858 | } | |
1859 | else | |
1860 | { | |
98c07c54 | 1861 | /* If the loop does not have an exit, reconnect header and latch. */ |
36b24193 ZD |
1862 | make_edge (loop->header, loop->latch, EDGE_FALLTHRU); |
1863 | set_immediate_dominator (CDI_DOMINATORS, loop->latch, loop->header); | |
1864 | } | |
0ecf0d5f | 1865 | |
36b24193 ZD |
1866 | merge_target_bb = loop->header; |
1867 | for (i = 1; i < orig_loop_num_nodes; i++) | |
1868 | { | |
726a989a RB |
1869 | gimple_stmt_iterator gsi; |
1870 | gimple_stmt_iterator last; | |
ac0bd801 | 1871 | |
36b24193 | 1872 | bb = ifc_bbs[i]; |
537a2904 | 1873 | |
36b24193 ZD |
1874 | if (bb == exit_bb || bb == loop->latch) |
1875 | continue; | |
537a2904 | 1876 | |
76b84776 SP |
1877 | /* Make stmts member of loop->header. */ |
1878 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
1879 | gimple_set_bb (gsi_stmt (gsi), merge_target_bb); | |
40923b20 DP |
1880 | |
1881 | /* Update stmt list. */ | |
726a989a RB |
1882 | last = gsi_last_bb (merge_target_bb); |
1883 | gsi_insert_seq_after (&last, bb_seq (bb), GSI_NEW_STMT); | |
1884 | set_bb_seq (bb, NULL); | |
40923b20 | 1885 | |
598ec7bd | 1886 | delete_basic_block (bb); |
40923b20 | 1887 | } |
a2159c4c | 1888 | |
98c07c54 SP |
1889 | /* If possible, merge loop header to the block with the exit edge. |
1890 | This reduces the number of basic blocks to two, to please the | |
0f741287 | 1891 | vectorizer that handles only loops with two nodes. */ |
0ecf0d5f | 1892 | if (exit_bb |
36b24193 ZD |
1893 | && exit_bb != loop->header |
1894 | && can_merge_blocks_p (loop->header, exit_bb)) | |
598ec7bd | 1895 | merge_blocks (loop->header, exit_bb); |
c2b5fc8d JJ |
1896 | |
1897 | free (ifc_bbs); | |
1898 | ifc_bbs = NULL; | |
40923b20 DP |
1899 | } |
1900 | ||
5ce9450f JJ |
1901 | /* Version LOOP before if-converting it, the original loop |
1902 | will be then if-converted, the new copy of the loop will not, | |
1903 | and the LOOP_VECTORIZED internal call will be guarding which | |
1904 | loop to execute. The vectorizer pass will fold this | |
1905 | internal call into either true or false. */ | |
40923b20 | 1906 | |
0f741287 | 1907 | static bool |
5ce9450f JJ |
1908 | version_loop_for_if_conversion (struct loop *loop) |
1909 | { | |
1910 | basic_block cond_bb; | |
1911 | tree cond = make_ssa_name (boolean_type_node, NULL); | |
1912 | struct loop *new_loop; | |
1913 | gimple g; | |
1914 | gimple_stmt_iterator gsi; | |
1915 | ||
1916 | g = gimple_build_call_internal (IFN_LOOP_VECTORIZED, 2, | |
1917 | build_int_cst (integer_type_node, loop->num), | |
1918 | integer_zero_node); | |
1919 | gimple_call_set_lhs (g, cond); | |
1920 | ||
1921 | initialize_original_copy_tables (); | |
1922 | new_loop = loop_version (loop, cond, &cond_bb, | |
1923 | REG_BR_PROB_BASE, REG_BR_PROB_BASE, | |
1924 | REG_BR_PROB_BASE, true); | |
1925 | free_original_copy_tables (); | |
1926 | if (new_loop == NULL) | |
1927 | return false; | |
1928 | new_loop->dont_vectorize = true; | |
b15b5979 | 1929 | new_loop->force_vectorize = false; |
5ce9450f JJ |
1930 | gsi = gsi_last_bb (cond_bb); |
1931 | gimple_call_set_arg (g, 1, build_int_cst (integer_type_node, new_loop->num)); | |
1932 | gsi_insert_before (&gsi, g, GSI_SAME_STMT); | |
1933 | update_ssa (TODO_update_ssa); | |
1934 | return true; | |
1935 | } | |
1936 | ||
1937 | /* If-convert LOOP when it is legal. For the moment this pass has no | |
1938 | profitability analysis. Returns non-zero todo flags when something | |
1939 | changed. */ | |
1940 | ||
1941 | static unsigned int | |
6cbcfa9d | 1942 | tree_if_conversion (struct loop *loop) |
40923b20 | 1943 | { |
5ce9450f | 1944 | unsigned int todo = 0; |
baaa8e96 | 1945 | ifc_bbs = NULL; |
5ce9450f | 1946 | bool any_mask_load_store = false; |
40923b20 | 1947 | |
5ce9450f | 1948 | if (!if_convertible_loop_p (loop, &any_mask_load_store) |
53aa40a8 | 1949 | || !dbg_cnt (if_conversion_tree)) |
e1449456 | 1950 | goto cleanup; |
b6779d81 | 1951 | |
5ce9450f | 1952 | if (any_mask_load_store |
b15b5979 | 1953 | && ((!flag_tree_loop_vectorize && !loop->force_vectorize) |
5ce9450f JJ |
1954 | || loop->dont_vectorize)) |
1955 | goto cleanup; | |
1956 | ||
1957 | if (any_mask_load_store && !version_loop_for_if_conversion (loop)) | |
1958 | goto cleanup; | |
1959 | ||
e1449456 SP |
1960 | /* Now all statements are if-convertible. Combine all the basic |
1961 | blocks into one huge basic block doing the if-conversion | |
1962 | on-the-fly. */ | |
5ce9450f | 1963 | combine_blocks (loop, any_mask_load_store); |
bd544141 | 1964 | |
5ce9450f JJ |
1965 | todo |= TODO_cleanup_cfg; |
1966 | if (flag_tree_loop_if_convert_stores || any_mask_load_store) | |
1967 | { | |
1968 | mark_virtual_operands_for_renaming (cfun); | |
1969 | todo |= TODO_update_ssa_only_virtuals; | |
1970 | } | |
40923b20 | 1971 | |
e1449456 | 1972 | cleanup: |
e1449456 SP |
1973 | if (ifc_bbs) |
1974 | { | |
7b14477e SP |
1975 | unsigned int i; |
1976 | ||
1977 | for (i = 0; i < loop->num_nodes; i++) | |
1978 | free_bb_predicate (ifc_bbs[i]); | |
1979 | ||
e1449456 SP |
1980 | free (ifc_bbs); |
1981 | ifc_bbs = NULL; | |
1982 | } | |
0f741287 | 1983 | |
5ce9450f | 1984 | return todo; |
40923b20 DP |
1985 | } |
1986 | ||
1987 | /* Tree if-conversion pass management. */ | |
1988 | ||
c2924966 | 1989 | static unsigned int |
40923b20 DP |
1990 | main_tree_if_conversion (void) |
1991 | { | |
40923b20 | 1992 | struct loop *loop; |
bd544141 | 1993 | unsigned todo = 0; |
40923b20 | 1994 | |
0fc822d0 | 1995 | if (number_of_loops (cfun) <= 1) |
c2924966 | 1996 | return 0; |
40923b20 | 1997 | |
f0bd40b1 | 1998 | FOR_EACH_LOOP (loop, 0) |
74bf76ed JJ |
1999 | if (flag_tree_loop_if_convert == 1 |
2000 | || flag_tree_loop_if_convert_stores == 1 | |
b15b5979 | 2001 | || ((flag_tree_loop_vectorize || loop->force_vectorize) |
5ce9450f JJ |
2002 | && !loop->dont_vectorize)) |
2003 | todo |= tree_if_conversion (loop); | |
bd544141 | 2004 | |
c6542175 | 2005 | #ifdef ENABLE_CHECKING |
05232ff6 RB |
2006 | { |
2007 | basic_block bb; | |
11cd3bed | 2008 | FOR_EACH_BB_FN (bb, cfun) |
05232ff6 RB |
2009 | gcc_assert (!bb->aux); |
2010 | } | |
c6542175 RG |
2011 | #endif |
2012 | ||
bd544141 | 2013 | return todo; |
40923b20 DP |
2014 | } |
2015 | ||
384a5197 SP |
2016 | /* Returns true when the if-conversion pass is enabled. */ |
2017 | ||
40923b20 DP |
2018 | static bool |
2019 | gate_tree_if_conversion (void) | |
2020 | { | |
b15b5979 | 2021 | return (((flag_tree_loop_vectorize || cfun->has_force_vectorize_loops) |
74bf76ed | 2022 | && flag_tree_loop_if_convert != 0) |
bd544141 SP |
2023 | || flag_tree_loop_if_convert == 1 |
2024 | || flag_tree_loop_if_convert_stores == 1); | |
40923b20 DP |
2025 | } |
2026 | ||
27a4cd48 DM |
2027 | namespace { |
2028 | ||
2029 | const pass_data pass_data_if_conversion = | |
40923b20 | 2030 | { |
27a4cd48 DM |
2031 | GIMPLE_PASS, /* type */ |
2032 | "ifcvt", /* name */ | |
2033 | OPTGROUP_NONE, /* optinfo_flags */ | |
2034 | true, /* has_gate */ | |
2035 | true, /* has_execute */ | |
2036 | TV_NONE, /* tv_id */ | |
2037 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
2038 | 0, /* properties_provided */ | |
2039 | 0, /* properties_destroyed */ | |
2040 | 0, /* todo_flags_start */ | |
4ded8276 RB |
2041 | ( TODO_verify_stmts | TODO_verify_flow |
2042 | | TODO_verify_ssa ), /* todo_flags_finish */ | |
40923b20 | 2043 | }; |
27a4cd48 DM |
2044 | |
2045 | class pass_if_conversion : public gimple_opt_pass | |
2046 | { | |
2047 | public: | |
c3284718 RS |
2048 | pass_if_conversion (gcc::context *ctxt) |
2049 | : gimple_opt_pass (pass_data_if_conversion, ctxt) | |
27a4cd48 DM |
2050 | {} |
2051 | ||
2052 | /* opt_pass methods: */ | |
2053 | bool gate () { return gate_tree_if_conversion (); } | |
2054 | unsigned int execute () { return main_tree_if_conversion (); } | |
2055 | ||
2056 | }; // class pass_if_conversion | |
2057 | ||
2058 | } // anon namespace | |
2059 | ||
2060 | gimple_opt_pass * | |
2061 | make_pass_if_conversion (gcc::context *ctxt) | |
2062 | { | |
2063 | return new pass_if_conversion (ctxt); | |
2064 | } |