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comparison gcc/tree-vect-patterns.c @ 0:a06113de4d67
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author | kent <kent@cr.ie.u-ryukyu.ac.jp> |
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date | Fri, 17 Jul 2009 14:47:48 +0900 |
parents | |
children | 77e2b8dfacca |
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1 /* Analysis Utilities for Loop Vectorization. | |
2 Copyright (C) 2006, 2007, 2008 Free Software Foundation, Inc. | |
3 Contributed by Dorit Nuzman <dorit@il.ibm.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 | |
9 Software Foundation; either version 3, or (at your option) any later | |
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 | |
18 along with GCC; see the file COPYING3. If not see | |
19 <http://www.gnu.org/licenses/>. */ | |
20 | |
21 #include "config.h" | |
22 #include "system.h" | |
23 #include "coretypes.h" | |
24 #include "tm.h" | |
25 #include "ggc.h" | |
26 #include "tree.h" | |
27 | |
28 #include "target.h" | |
29 #include "basic-block.h" | |
30 #include "diagnostic.h" | |
31 #include "tree-flow.h" | |
32 #include "tree-dump.h" | |
33 #include "timevar.h" | |
34 #include "cfgloop.h" | |
35 #include "expr.h" | |
36 #include "optabs.h" | |
37 #include "params.h" | |
38 #include "tree-data-ref.h" | |
39 #include "tree-vectorizer.h" | |
40 #include "recog.h" | |
41 #include "toplev.h" | |
42 | |
43 /* Function prototypes */ | |
44 static void vect_pattern_recog_1 | |
45 (gimple (* ) (gimple, tree *, tree *), gimple_stmt_iterator); | |
46 static bool widened_name_p (tree, gimple, tree *, gimple *); | |
47 | |
48 /* Pattern recognition functions */ | |
49 static gimple vect_recog_widen_sum_pattern (gimple, tree *, tree *); | |
50 static gimple vect_recog_widen_mult_pattern (gimple, tree *, tree *); | |
51 static gimple vect_recog_dot_prod_pattern (gimple, tree *, tree *); | |
52 static gimple vect_recog_pow_pattern (gimple, tree *, tree *); | |
53 static vect_recog_func_ptr vect_vect_recog_func_ptrs[NUM_PATTERNS] = { | |
54 vect_recog_widen_mult_pattern, | |
55 vect_recog_widen_sum_pattern, | |
56 vect_recog_dot_prod_pattern, | |
57 vect_recog_pow_pattern}; | |
58 | |
59 | |
60 /* Function widened_name_p | |
61 | |
62 Check whether NAME, an ssa-name used in USE_STMT, | |
63 is a result of a type-promotion, such that: | |
64 DEF_STMT: NAME = NOP (name0) | |
65 where the type of name0 (HALF_TYPE) is smaller than the type of NAME. | |
66 */ | |
67 | |
68 static bool | |
69 widened_name_p (tree name, gimple use_stmt, tree *half_type, gimple *def_stmt) | |
70 { | |
71 tree dummy; | |
72 gimple dummy_gimple; | |
73 loop_vec_info loop_vinfo; | |
74 stmt_vec_info stmt_vinfo; | |
75 tree type = TREE_TYPE (name); | |
76 tree oprnd0; | |
77 enum vect_def_type dt; | |
78 tree def; | |
79 | |
80 stmt_vinfo = vinfo_for_stmt (use_stmt); | |
81 loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_vinfo); | |
82 | |
83 if (!vect_is_simple_use (name, loop_vinfo, def_stmt, &def, &dt)) | |
84 return false; | |
85 | |
86 if (dt != vect_loop_def | |
87 && dt != vect_invariant_def && dt != vect_constant_def) | |
88 return false; | |
89 | |
90 if (! *def_stmt) | |
91 return false; | |
92 | |
93 if (!is_gimple_assign (*def_stmt)) | |
94 return false; | |
95 | |
96 if (gimple_assign_rhs_code (*def_stmt) != NOP_EXPR) | |
97 return false; | |
98 | |
99 oprnd0 = gimple_assign_rhs1 (*def_stmt); | |
100 | |
101 *half_type = TREE_TYPE (oprnd0); | |
102 if (!INTEGRAL_TYPE_P (type) || !INTEGRAL_TYPE_P (*half_type) | |
103 || (TYPE_UNSIGNED (type) != TYPE_UNSIGNED (*half_type)) | |
104 || (TYPE_PRECISION (type) < (TYPE_PRECISION (*half_type) * 2))) | |
105 return false; | |
106 | |
107 if (!vect_is_simple_use (oprnd0, loop_vinfo, &dummy_gimple, &dummy, &dt)) | |
108 return false; | |
109 | |
110 return true; | |
111 } | |
112 | |
113 /* Helper to return a new temporary for pattern of TYPE for STMT. If STMT | |
114 is NULL, the caller must set SSA_NAME_DEF_STMT for the returned SSA var. */ | |
115 | |
116 static tree | |
117 vect_recog_temp_ssa_var (tree type, gimple stmt) | |
118 { | |
119 tree var = create_tmp_var (type, "patt"); | |
120 | |
121 add_referenced_var (var); | |
122 var = make_ssa_name (var, stmt); | |
123 return var; | |
124 } | |
125 | |
126 /* Function vect_recog_dot_prod_pattern | |
127 | |
128 Try to find the following pattern: | |
129 | |
130 type x_t, y_t; | |
131 TYPE1 prod; | |
132 TYPE2 sum = init; | |
133 loop: | |
134 sum_0 = phi <init, sum_1> | |
135 S1 x_t = ... | |
136 S2 y_t = ... | |
137 S3 x_T = (TYPE1) x_t; | |
138 S4 y_T = (TYPE1) y_t; | |
139 S5 prod = x_T * y_T; | |
140 [S6 prod = (TYPE2) prod; #optional] | |
141 S7 sum_1 = prod + sum_0; | |
142 | |
143 where 'TYPE1' is exactly double the size of type 'type', and 'TYPE2' is the | |
144 same size of 'TYPE1' or bigger. This is a special case of a reduction | |
145 computation. | |
146 | |
147 Input: | |
148 | |
149 * LAST_STMT: A stmt from which the pattern search begins. In the example, | |
150 when this function is called with S7, the pattern {S3,S4,S5,S6,S7} will be | |
151 detected. | |
152 | |
153 Output: | |
154 | |
155 * TYPE_IN: The type of the input arguments to the pattern. | |
156 | |
157 * TYPE_OUT: The type of the output of this pattern. | |
158 | |
159 * Return value: A new stmt that will be used to replace the sequence of | |
160 stmts that constitute the pattern. In this case it will be: | |
161 WIDEN_DOT_PRODUCT <x_t, y_t, sum_0> | |
162 | |
163 Note: The dot-prod idiom is a widening reduction pattern that is | |
164 vectorized without preserving all the intermediate results. It | |
165 produces only N/2 (widened) results (by summing up pairs of | |
166 intermediate results) rather than all N results. Therefore, we | |
167 cannot allow this pattern when we want to get all the results and in | |
168 the correct order (as is the case when this computation is in an | |
169 inner-loop nested in an outer-loop that us being vectorized). */ | |
170 | |
171 static gimple | |
172 vect_recog_dot_prod_pattern (gimple last_stmt, tree *type_in, tree *type_out) | |
173 { | |
174 gimple stmt; | |
175 tree oprnd0, oprnd1; | |
176 tree oprnd00, oprnd01; | |
177 stmt_vec_info stmt_vinfo = vinfo_for_stmt (last_stmt); | |
178 tree type, half_type; | |
179 gimple pattern_stmt; | |
180 tree prod_type; | |
181 loop_vec_info loop_info = STMT_VINFO_LOOP_VINFO (stmt_vinfo); | |
182 struct loop *loop = LOOP_VINFO_LOOP (loop_info); | |
183 tree var, rhs; | |
184 | |
185 if (!is_gimple_assign (last_stmt)) | |
186 return NULL; | |
187 | |
188 type = gimple_expr_type (last_stmt); | |
189 | |
190 /* Look for the following pattern | |
191 DX = (TYPE1) X; | |
192 DY = (TYPE1) Y; | |
193 DPROD = DX * DY; | |
194 DDPROD = (TYPE2) DPROD; | |
195 sum_1 = DDPROD + sum_0; | |
196 In which | |
197 - DX is double the size of X | |
198 - DY is double the size of Y | |
199 - DX, DY, DPROD all have the same type | |
200 - sum is the same size of DPROD or bigger | |
201 - sum has been recognized as a reduction variable. | |
202 | |
203 This is equivalent to: | |
204 DPROD = X w* Y; #widen mult | |
205 sum_1 = DPROD w+ sum_0; #widen summation | |
206 or | |
207 DPROD = X w* Y; #widen mult | |
208 sum_1 = DPROD + sum_0; #summation | |
209 */ | |
210 | |
211 /* Starting from LAST_STMT, follow the defs of its uses in search | |
212 of the above pattern. */ | |
213 | |
214 if (gimple_assign_rhs_code (last_stmt) != PLUS_EXPR) | |
215 return NULL; | |
216 | |
217 if (STMT_VINFO_IN_PATTERN_P (stmt_vinfo)) | |
218 { | |
219 /* Has been detected as widening-summation? */ | |
220 | |
221 stmt = STMT_VINFO_RELATED_STMT (stmt_vinfo); | |
222 type = gimple_expr_type (stmt); | |
223 if (gimple_assign_rhs_code (stmt) != WIDEN_SUM_EXPR) | |
224 return NULL; | |
225 oprnd0 = gimple_assign_rhs1 (stmt); | |
226 oprnd1 = gimple_assign_rhs2 (stmt); | |
227 half_type = TREE_TYPE (oprnd0); | |
228 } | |
229 else | |
230 { | |
231 gimple def_stmt; | |
232 | |
233 if (STMT_VINFO_DEF_TYPE (stmt_vinfo) != vect_reduction_def) | |
234 return NULL; | |
235 oprnd0 = gimple_assign_rhs1 (last_stmt); | |
236 oprnd1 = gimple_assign_rhs2 (last_stmt); | |
237 if (TYPE_MAIN_VARIANT (TREE_TYPE (oprnd0)) != TYPE_MAIN_VARIANT (type) | |
238 || TYPE_MAIN_VARIANT (TREE_TYPE (oprnd1)) != TYPE_MAIN_VARIANT (type)) | |
239 return NULL; | |
240 stmt = last_stmt; | |
241 | |
242 if (widened_name_p (oprnd0, stmt, &half_type, &def_stmt)) | |
243 { | |
244 stmt = def_stmt; | |
245 oprnd0 = gimple_assign_rhs1 (stmt); | |
246 } | |
247 else | |
248 half_type = type; | |
249 } | |
250 | |
251 /* So far so good. Since last_stmt was detected as a (summation) reduction, | |
252 we know that oprnd1 is the reduction variable (defined by a loop-header | |
253 phi), and oprnd0 is an ssa-name defined by a stmt in the loop body. | |
254 Left to check that oprnd0 is defined by a (widen_)mult_expr */ | |
255 | |
256 prod_type = half_type; | |
257 stmt = SSA_NAME_DEF_STMT (oprnd0); | |
258 /* FORNOW. Can continue analyzing the def-use chain when this stmt in a phi | |
259 inside the loop (in case we are analyzing an outer-loop). */ | |
260 if (!is_gimple_assign (stmt)) | |
261 return NULL; | |
262 stmt_vinfo = vinfo_for_stmt (stmt); | |
263 gcc_assert (stmt_vinfo); | |
264 if (STMT_VINFO_DEF_TYPE (stmt_vinfo) != vect_loop_def) | |
265 return NULL; | |
266 if (gimple_assign_rhs_code (stmt) != MULT_EXPR) | |
267 return NULL; | |
268 if (STMT_VINFO_IN_PATTERN_P (stmt_vinfo)) | |
269 { | |
270 /* Has been detected as a widening multiplication? */ | |
271 | |
272 stmt = STMT_VINFO_RELATED_STMT (stmt_vinfo); | |
273 if (gimple_assign_rhs_code (stmt) != WIDEN_MULT_EXPR) | |
274 return NULL; | |
275 stmt_vinfo = vinfo_for_stmt (stmt); | |
276 gcc_assert (stmt_vinfo); | |
277 gcc_assert (STMT_VINFO_DEF_TYPE (stmt_vinfo) == vect_loop_def); | |
278 oprnd00 = gimple_assign_rhs1 (stmt); | |
279 oprnd01 = gimple_assign_rhs2 (stmt); | |
280 } | |
281 else | |
282 { | |
283 tree half_type0, half_type1; | |
284 gimple def_stmt; | |
285 tree oprnd0, oprnd1; | |
286 | |
287 oprnd0 = gimple_assign_rhs1 (stmt); | |
288 oprnd1 = gimple_assign_rhs2 (stmt); | |
289 if (TYPE_MAIN_VARIANT (TREE_TYPE (oprnd0)) | |
290 != TYPE_MAIN_VARIANT (prod_type) | |
291 || TYPE_MAIN_VARIANT (TREE_TYPE (oprnd1)) | |
292 != TYPE_MAIN_VARIANT (prod_type)) | |
293 return NULL; | |
294 if (!widened_name_p (oprnd0, stmt, &half_type0, &def_stmt)) | |
295 return NULL; | |
296 oprnd00 = gimple_assign_rhs1 (def_stmt); | |
297 if (!widened_name_p (oprnd1, stmt, &half_type1, &def_stmt)) | |
298 return NULL; | |
299 oprnd01 = gimple_assign_rhs1 (def_stmt); | |
300 if (TYPE_MAIN_VARIANT (half_type0) != TYPE_MAIN_VARIANT (half_type1)) | |
301 return NULL; | |
302 if (TYPE_PRECISION (prod_type) != TYPE_PRECISION (half_type0) * 2) | |
303 return NULL; | |
304 } | |
305 | |
306 half_type = TREE_TYPE (oprnd00); | |
307 *type_in = half_type; | |
308 *type_out = type; | |
309 | |
310 /* Pattern detected. Create a stmt to be used to replace the pattern: */ | |
311 var = vect_recog_temp_ssa_var (type, NULL); | |
312 rhs = build3 (DOT_PROD_EXPR, type, oprnd00, oprnd01, oprnd1), | |
313 pattern_stmt = gimple_build_assign (var, rhs); | |
314 | |
315 if (vect_print_dump_info (REPORT_DETAILS)) | |
316 { | |
317 fprintf (vect_dump, "vect_recog_dot_prod_pattern: detected: "); | |
318 print_gimple_stmt (vect_dump, pattern_stmt, 0, TDF_SLIM); | |
319 } | |
320 | |
321 /* We don't allow changing the order of the computation in the inner-loop | |
322 when doing outer-loop vectorization. */ | |
323 if (nested_in_vect_loop_p (loop, last_stmt)) | |
324 { | |
325 if (vect_print_dump_info (REPORT_DETAILS)) | |
326 fprintf (vect_dump, "vect_recog_dot_prod_pattern: not allowed."); | |
327 return NULL; | |
328 } | |
329 | |
330 return pattern_stmt; | |
331 } | |
332 | |
333 /* Function vect_recog_widen_mult_pattern | |
334 | |
335 Try to find the following pattern: | |
336 | |
337 type a_t, b_t; | |
338 TYPE a_T, b_T, prod_T; | |
339 | |
340 S1 a_t = ; | |
341 S2 b_t = ; | |
342 S3 a_T = (TYPE) a_t; | |
343 S4 b_T = (TYPE) b_t; | |
344 S5 prod_T = a_T * b_T; | |
345 | |
346 where type 'TYPE' is at least double the size of type 'type'. | |
347 | |
348 Input: | |
349 | |
350 * LAST_STMT: A stmt from which the pattern search begins. In the example, | |
351 when this function is called with S5, the pattern {S3,S4,S5} is be detected. | |
352 | |
353 Output: | |
354 | |
355 * TYPE_IN: The type of the input arguments to the pattern. | |
356 | |
357 * TYPE_OUT: The type of the output of this pattern. | |
358 | |
359 * Return value: A new stmt that will be used to replace the sequence of | |
360 stmts that constitute the pattern. In this case it will be: | |
361 WIDEN_MULT <a_t, b_t> | |
362 */ | |
363 | |
364 static gimple | |
365 vect_recog_widen_mult_pattern (gimple last_stmt, | |
366 tree *type_in, | |
367 tree *type_out) | |
368 { | |
369 gimple def_stmt0, def_stmt1; | |
370 tree oprnd0, oprnd1; | |
371 tree type, half_type0, half_type1; | |
372 gimple pattern_stmt; | |
373 tree vectype; | |
374 tree dummy; | |
375 tree var; | |
376 enum tree_code dummy_code; | |
377 int dummy_int; | |
378 VEC (tree, heap) *dummy_vec; | |
379 | |
380 if (!is_gimple_assign (last_stmt)) | |
381 return NULL; | |
382 | |
383 type = gimple_expr_type (last_stmt); | |
384 | |
385 /* Starting from LAST_STMT, follow the defs of its uses in search | |
386 of the above pattern. */ | |
387 | |
388 if (gimple_assign_rhs_code (last_stmt) != MULT_EXPR) | |
389 return NULL; | |
390 | |
391 oprnd0 = gimple_assign_rhs1 (last_stmt); | |
392 oprnd1 = gimple_assign_rhs2 (last_stmt); | |
393 if (TYPE_MAIN_VARIANT (TREE_TYPE (oprnd0)) != TYPE_MAIN_VARIANT (type) | |
394 || TYPE_MAIN_VARIANT (TREE_TYPE (oprnd1)) != TYPE_MAIN_VARIANT (type)) | |
395 return NULL; | |
396 | |
397 /* Check argument 0 */ | |
398 if (!widened_name_p (oprnd0, last_stmt, &half_type0, &def_stmt0)) | |
399 return NULL; | |
400 oprnd0 = gimple_assign_rhs1 (def_stmt0); | |
401 | |
402 /* Check argument 1 */ | |
403 if (!widened_name_p (oprnd1, last_stmt, &half_type1, &def_stmt1)) | |
404 return NULL; | |
405 oprnd1 = gimple_assign_rhs1 (def_stmt1); | |
406 | |
407 if (TYPE_MAIN_VARIANT (half_type0) != TYPE_MAIN_VARIANT (half_type1)) | |
408 return NULL; | |
409 | |
410 /* Pattern detected. */ | |
411 if (vect_print_dump_info (REPORT_DETAILS)) | |
412 fprintf (vect_dump, "vect_recog_widen_mult_pattern: detected: "); | |
413 | |
414 /* Check target support */ | |
415 vectype = get_vectype_for_scalar_type (half_type0); | |
416 if (!vectype | |
417 || !supportable_widening_operation (WIDEN_MULT_EXPR, last_stmt, vectype, | |
418 &dummy, &dummy, &dummy_code, | |
419 &dummy_code, &dummy_int, &dummy_vec)) | |
420 return NULL; | |
421 | |
422 *type_in = vectype; | |
423 *type_out = NULL_TREE; | |
424 | |
425 /* Pattern supported. Create a stmt to be used to replace the pattern: */ | |
426 var = vect_recog_temp_ssa_var (type, NULL); | |
427 pattern_stmt = gimple_build_assign_with_ops (WIDEN_MULT_EXPR, var, oprnd0, | |
428 oprnd1); | |
429 SSA_NAME_DEF_STMT (var) = pattern_stmt; | |
430 | |
431 if (vect_print_dump_info (REPORT_DETAILS)) | |
432 print_gimple_stmt (vect_dump, pattern_stmt, 0, TDF_SLIM); | |
433 | |
434 return pattern_stmt; | |
435 } | |
436 | |
437 | |
438 /* Function vect_recog_pow_pattern | |
439 | |
440 Try to find the following pattern: | |
441 | |
442 x = POW (y, N); | |
443 | |
444 with POW being one of pow, powf, powi, powif and N being | |
445 either 2 or 0.5. | |
446 | |
447 Input: | |
448 | |
449 * LAST_STMT: A stmt from which the pattern search begins. | |
450 | |
451 Output: | |
452 | |
453 * TYPE_IN: The type of the input arguments to the pattern. | |
454 | |
455 * TYPE_OUT: The type of the output of this pattern. | |
456 | |
457 * Return value: A new stmt that will be used to replace the sequence of | |
458 stmts that constitute the pattern. In this case it will be: | |
459 x = x * x | |
460 or | |
461 x = sqrt (x) | |
462 */ | |
463 | |
464 static gimple | |
465 vect_recog_pow_pattern (gimple last_stmt, tree *type_in, tree *type_out) | |
466 { | |
467 tree type; | |
468 tree fn, base, exp = NULL; | |
469 gimple stmt; | |
470 tree var; | |
471 | |
472 if (!is_gimple_call (last_stmt) || gimple_call_lhs (last_stmt) == NULL) | |
473 return NULL; | |
474 | |
475 type = gimple_expr_type (last_stmt); | |
476 | |
477 fn = gimple_call_fndecl (last_stmt); | |
478 switch (DECL_FUNCTION_CODE (fn)) | |
479 { | |
480 case BUILT_IN_POWIF: | |
481 case BUILT_IN_POWI: | |
482 case BUILT_IN_POWF: | |
483 case BUILT_IN_POW: | |
484 base = gimple_call_arg (last_stmt, 0); | |
485 exp = gimple_call_arg (last_stmt, 1); | |
486 if (TREE_CODE (exp) != REAL_CST | |
487 && TREE_CODE (exp) != INTEGER_CST) | |
488 return NULL; | |
489 break; | |
490 | |
491 default: | |
492 return NULL; | |
493 } | |
494 | |
495 /* We now have a pow or powi builtin function call with a constant | |
496 exponent. */ | |
497 | |
498 *type_out = NULL_TREE; | |
499 | |
500 /* Catch squaring. */ | |
501 if ((host_integerp (exp, 0) | |
502 && tree_low_cst (exp, 0) == 2) | |
503 || (TREE_CODE (exp) == REAL_CST | |
504 && REAL_VALUES_EQUAL (TREE_REAL_CST (exp), dconst2))) | |
505 { | |
506 *type_in = TREE_TYPE (base); | |
507 | |
508 var = vect_recog_temp_ssa_var (TREE_TYPE (base), NULL); | |
509 stmt = gimple_build_assign_with_ops (MULT_EXPR, var, base, base); | |
510 SSA_NAME_DEF_STMT (var) = stmt; | |
511 return stmt; | |
512 } | |
513 | |
514 /* Catch square root. */ | |
515 if (TREE_CODE (exp) == REAL_CST | |
516 && REAL_VALUES_EQUAL (TREE_REAL_CST (exp), dconsthalf)) | |
517 { | |
518 tree newfn = mathfn_built_in (TREE_TYPE (base), BUILT_IN_SQRT); | |
519 *type_in = get_vectype_for_scalar_type (TREE_TYPE (base)); | |
520 if (*type_in) | |
521 { | |
522 gimple stmt = gimple_build_call (newfn, 1, base); | |
523 if (vectorizable_function (stmt, *type_in, *type_in) | |
524 != NULL_TREE) | |
525 { | |
526 var = vect_recog_temp_ssa_var (TREE_TYPE (base), stmt); | |
527 gimple_call_set_lhs (stmt, var); | |
528 return stmt; | |
529 } | |
530 } | |
531 } | |
532 | |
533 return NULL; | |
534 } | |
535 | |
536 | |
537 /* Function vect_recog_widen_sum_pattern | |
538 | |
539 Try to find the following pattern: | |
540 | |
541 type x_t; | |
542 TYPE x_T, sum = init; | |
543 loop: | |
544 sum_0 = phi <init, sum_1> | |
545 S1 x_t = *p; | |
546 S2 x_T = (TYPE) x_t; | |
547 S3 sum_1 = x_T + sum_0; | |
548 | |
549 where type 'TYPE' is at least double the size of type 'type', i.e - we're | |
550 summing elements of type 'type' into an accumulator of type 'TYPE'. This is | |
551 a special case of a reduction computation. | |
552 | |
553 Input: | |
554 | |
555 * LAST_STMT: A stmt from which the pattern search begins. In the example, | |
556 when this function is called with S3, the pattern {S2,S3} will be detected. | |
557 | |
558 Output: | |
559 | |
560 * TYPE_IN: The type of the input arguments to the pattern. | |
561 | |
562 * TYPE_OUT: The type of the output of this pattern. | |
563 | |
564 * Return value: A new stmt that will be used to replace the sequence of | |
565 stmts that constitute the pattern. In this case it will be: | |
566 WIDEN_SUM <x_t, sum_0> | |
567 | |
568 Note: The widening-sum idiom is a widening reduction pattern that is | |
569 vectorized without preserving all the intermediate results. It | |
570 produces only N/2 (widened) results (by summing up pairs of | |
571 intermediate results) rather than all N results. Therefore, we | |
572 cannot allow this pattern when we want to get all the results and in | |
573 the correct order (as is the case when this computation is in an | |
574 inner-loop nested in an outer-loop that us being vectorized). */ | |
575 | |
576 static gimple | |
577 vect_recog_widen_sum_pattern (gimple last_stmt, tree *type_in, tree *type_out) | |
578 { | |
579 gimple stmt; | |
580 tree oprnd0, oprnd1; | |
581 stmt_vec_info stmt_vinfo = vinfo_for_stmt (last_stmt); | |
582 tree type, half_type; | |
583 gimple pattern_stmt; | |
584 loop_vec_info loop_info = STMT_VINFO_LOOP_VINFO (stmt_vinfo); | |
585 struct loop *loop = LOOP_VINFO_LOOP (loop_info); | |
586 tree var; | |
587 | |
588 if (!is_gimple_assign (last_stmt)) | |
589 return NULL; | |
590 | |
591 type = gimple_expr_type (last_stmt); | |
592 | |
593 /* Look for the following pattern | |
594 DX = (TYPE) X; | |
595 sum_1 = DX + sum_0; | |
596 In which DX is at least double the size of X, and sum_1 has been | |
597 recognized as a reduction variable. | |
598 */ | |
599 | |
600 /* Starting from LAST_STMT, follow the defs of its uses in search | |
601 of the above pattern. */ | |
602 | |
603 if (gimple_assign_rhs_code (last_stmt) != PLUS_EXPR) | |
604 return NULL; | |
605 | |
606 if (STMT_VINFO_DEF_TYPE (stmt_vinfo) != vect_reduction_def) | |
607 return NULL; | |
608 | |
609 oprnd0 = gimple_assign_rhs1 (last_stmt); | |
610 oprnd1 = gimple_assign_rhs2 (last_stmt); | |
611 if (TYPE_MAIN_VARIANT (TREE_TYPE (oprnd0)) != TYPE_MAIN_VARIANT (type) | |
612 || TYPE_MAIN_VARIANT (TREE_TYPE (oprnd1)) != TYPE_MAIN_VARIANT (type)) | |
613 return NULL; | |
614 | |
615 /* So far so good. Since last_stmt was detected as a (summation) reduction, | |
616 we know that oprnd1 is the reduction variable (defined by a loop-header | |
617 phi), and oprnd0 is an ssa-name defined by a stmt in the loop body. | |
618 Left to check that oprnd0 is defined by a cast from type 'type' to type | |
619 'TYPE'. */ | |
620 | |
621 if (!widened_name_p (oprnd0, last_stmt, &half_type, &stmt)) | |
622 return NULL; | |
623 | |
624 oprnd0 = gimple_assign_rhs1 (stmt); | |
625 *type_in = half_type; | |
626 *type_out = type; | |
627 | |
628 /* Pattern detected. Create a stmt to be used to replace the pattern: */ | |
629 var = vect_recog_temp_ssa_var (type, NULL); | |
630 pattern_stmt = gimple_build_assign_with_ops (WIDEN_SUM_EXPR, var, | |
631 oprnd0, oprnd1); | |
632 SSA_NAME_DEF_STMT (var) = pattern_stmt; | |
633 | |
634 if (vect_print_dump_info (REPORT_DETAILS)) | |
635 { | |
636 fprintf (vect_dump, "vect_recog_widen_sum_pattern: detected: "); | |
637 print_gimple_stmt (vect_dump, pattern_stmt, 0, TDF_SLIM); | |
638 } | |
639 | |
640 /* We don't allow changing the order of the computation in the inner-loop | |
641 when doing outer-loop vectorization. */ | |
642 if (nested_in_vect_loop_p (loop, last_stmt)) | |
643 { | |
644 if (vect_print_dump_info (REPORT_DETAILS)) | |
645 fprintf (vect_dump, "vect_recog_widen_sum_pattern: not allowed."); | |
646 return NULL; | |
647 } | |
648 | |
649 return pattern_stmt; | |
650 } | |
651 | |
652 | |
653 /* Function vect_pattern_recog_1 | |
654 | |
655 Input: | |
656 PATTERN_RECOG_FUNC: A pointer to a function that detects a certain | |
657 computation pattern. | |
658 STMT: A stmt from which the pattern search should start. | |
659 | |
660 If PATTERN_RECOG_FUNC successfully detected the pattern, it creates an | |
661 expression that computes the same functionality and can be used to | |
662 replace the sequence of stmts that are involved in the pattern. | |
663 | |
664 Output: | |
665 This function checks if the expression returned by PATTERN_RECOG_FUNC is | |
666 supported in vector form by the target. We use 'TYPE_IN' to obtain the | |
667 relevant vector type. If 'TYPE_IN' is already a vector type, then this | |
668 indicates that target support had already been checked by PATTERN_RECOG_FUNC. | |
669 If 'TYPE_OUT' is also returned by PATTERN_RECOG_FUNC, we check that it fits | |
670 to the available target pattern. | |
671 | |
672 This function also does some bookkeeping, as explained in the documentation | |
673 for vect_recog_pattern. */ | |
674 | |
675 static void | |
676 vect_pattern_recog_1 ( | |
677 gimple (* vect_recog_func) (gimple, tree *, tree *), | |
678 gimple_stmt_iterator si) | |
679 { | |
680 gimple stmt = gsi_stmt (si), pattern_stmt; | |
681 stmt_vec_info stmt_info = vinfo_for_stmt (stmt); | |
682 stmt_vec_info pattern_stmt_info; | |
683 loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info); | |
684 tree pattern_vectype; | |
685 tree type_in, type_out; | |
686 enum tree_code code; | |
687 | |
688 pattern_stmt = (* vect_recog_func) (stmt, &type_in, &type_out); | |
689 if (!pattern_stmt) | |
690 return; | |
691 | |
692 if (VECTOR_MODE_P (TYPE_MODE (type_in))) | |
693 { | |
694 /* No need to check target support (already checked by the pattern | |
695 recognition function). */ | |
696 pattern_vectype = type_in; | |
697 } | |
698 else | |
699 { | |
700 enum tree_code vec_mode; | |
701 enum insn_code icode; | |
702 optab optab; | |
703 | |
704 /* Check target support */ | |
705 pattern_vectype = get_vectype_for_scalar_type (type_in); | |
706 if (!pattern_vectype) | |
707 return; | |
708 | |
709 if (is_gimple_assign (pattern_stmt)) | |
710 code = gimple_assign_rhs_code (pattern_stmt); | |
711 else | |
712 { | |
713 gcc_assert (is_gimple_call (pattern_stmt)); | |
714 code = CALL_EXPR; | |
715 } | |
716 | |
717 optab = optab_for_tree_code (code, pattern_vectype, optab_default); | |
718 vec_mode = TYPE_MODE (pattern_vectype); | |
719 if (!optab | |
720 || (icode = optab_handler (optab, vec_mode)->insn_code) == | |
721 CODE_FOR_nothing | |
722 || (type_out | |
723 && (!get_vectype_for_scalar_type (type_out) | |
724 || (insn_data[icode].operand[0].mode != | |
725 TYPE_MODE (get_vectype_for_scalar_type (type_out)))))) | |
726 return; | |
727 } | |
728 | |
729 /* Found a vectorizable pattern. */ | |
730 if (vect_print_dump_info (REPORT_DETAILS)) | |
731 { | |
732 fprintf (vect_dump, "pattern recognized: "); | |
733 print_gimple_stmt (vect_dump, pattern_stmt, 0, TDF_SLIM); | |
734 } | |
735 | |
736 /* Mark the stmts that are involved in the pattern. */ | |
737 gsi_insert_before (&si, pattern_stmt, GSI_SAME_STMT); | |
738 set_vinfo_for_stmt (pattern_stmt, | |
739 new_stmt_vec_info (pattern_stmt, loop_vinfo)); | |
740 pattern_stmt_info = vinfo_for_stmt (pattern_stmt); | |
741 | |
742 STMT_VINFO_RELATED_STMT (pattern_stmt_info) = stmt; | |
743 STMT_VINFO_DEF_TYPE (pattern_stmt_info) = STMT_VINFO_DEF_TYPE (stmt_info); | |
744 STMT_VINFO_VECTYPE (pattern_stmt_info) = pattern_vectype; | |
745 STMT_VINFO_IN_PATTERN_P (stmt_info) = true; | |
746 STMT_VINFO_RELATED_STMT (stmt_info) = pattern_stmt; | |
747 | |
748 return; | |
749 } | |
750 | |
751 | |
752 /* Function vect_pattern_recog | |
753 | |
754 Input: | |
755 LOOP_VINFO - a struct_loop_info of a loop in which we want to look for | |
756 computation idioms. | |
757 | |
758 Output - for each computation idiom that is detected we insert a new stmt | |
759 that provides the same functionality and that can be vectorized. We | |
760 also record some information in the struct_stmt_info of the relevant | |
761 stmts, as explained below: | |
762 | |
763 At the entry to this function we have the following stmts, with the | |
764 following initial value in the STMT_VINFO fields: | |
765 | |
766 stmt in_pattern_p related_stmt vec_stmt | |
767 S1: a_i = .... - - - | |
768 S2: a_2 = ..use(a_i).. - - - | |
769 S3: a_1 = ..use(a_2).. - - - | |
770 S4: a_0 = ..use(a_1).. - - - | |
771 S5: ... = ..use(a_0).. - - - | |
772 | |
773 Say the sequence {S1,S2,S3,S4} was detected as a pattern that can be | |
774 represented by a single stmt. We then: | |
775 - create a new stmt S6 that will replace the pattern. | |
776 - insert the new stmt S6 before the last stmt in the pattern | |
777 - fill in the STMT_VINFO fields as follows: | |
778 | |
779 in_pattern_p related_stmt vec_stmt | |
780 S1: a_i = .... - - - | |
781 S2: a_2 = ..use(a_i).. - - - | |
782 S3: a_1 = ..use(a_2).. - - - | |
783 > S6: a_new = .... - S4 - | |
784 S4: a_0 = ..use(a_1).. true S6 - | |
785 S5: ... = ..use(a_0).. - - - | |
786 | |
787 (the last stmt in the pattern (S4) and the new pattern stmt (S6) point | |
788 to each other through the RELATED_STMT field). | |
789 | |
790 S6 will be marked as relevant in vect_mark_stmts_to_be_vectorized instead | |
791 of S4 because it will replace all its uses. Stmts {S1,S2,S3} will | |
792 remain irrelevant unless used by stmts other than S4. | |
793 | |
794 If vectorization succeeds, vect_transform_stmt will skip over {S1,S2,S3} | |
795 (because they are marked as irrelevant). It will vectorize S6, and record | |
796 a pointer to the new vector stmt VS6 both from S6 (as usual), and also | |
797 from S4. We do that so that when we get to vectorizing stmts that use the | |
798 def of S4 (like S5 that uses a_0), we'll know where to take the relevant | |
799 vector-def from. S4 will be skipped, and S5 will be vectorized as usual: | |
800 | |
801 in_pattern_p related_stmt vec_stmt | |
802 S1: a_i = .... - - - | |
803 S2: a_2 = ..use(a_i).. - - - | |
804 S3: a_1 = ..use(a_2).. - - - | |
805 > VS6: va_new = .... - - - | |
806 S6: a_new = .... - S4 VS6 | |
807 S4: a_0 = ..use(a_1).. true S6 VS6 | |
808 > VS5: ... = ..vuse(va_new).. - - - | |
809 S5: ... = ..use(a_0).. - - - | |
810 | |
811 DCE could then get rid of {S1,S2,S3,S4,S5,S6} (if their defs are not used | |
812 elsewhere), and we'll end up with: | |
813 | |
814 VS6: va_new = .... | |
815 VS5: ... = ..vuse(va_new).. | |
816 | |
817 If vectorization does not succeed, DCE will clean S6 away (its def is | |
818 not used), and we'll end up with the original sequence. | |
819 */ | |
820 | |
821 void | |
822 vect_pattern_recog (loop_vec_info loop_vinfo) | |
823 { | |
824 struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); | |
825 basic_block *bbs = LOOP_VINFO_BBS (loop_vinfo); | |
826 unsigned int nbbs = loop->num_nodes; | |
827 gimple_stmt_iterator si; | |
828 gimple stmt; | |
829 unsigned int i, j; | |
830 gimple (* vect_recog_func_ptr) (gimple, tree *, tree *); | |
831 | |
832 if (vect_print_dump_info (REPORT_DETAILS)) | |
833 fprintf (vect_dump, "=== vect_pattern_recog ==="); | |
834 | |
835 /* Scan through the loop stmts, applying the pattern recognition | |
836 functions starting at each stmt visited: */ | |
837 for (i = 0; i < nbbs; i++) | |
838 { | |
839 basic_block bb = bbs[i]; | |
840 for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si)) | |
841 { | |
842 stmt = gsi_stmt (si); | |
843 | |
844 /* Scan over all generic vect_recog_xxx_pattern functions. */ | |
845 for (j = 0; j < NUM_PATTERNS; j++) | |
846 { | |
847 vect_recog_func_ptr = vect_vect_recog_func_ptrs[j]; | |
848 vect_pattern_recog_1 (vect_recog_func_ptr, si); | |
849 } | |
850 } | |
851 } | |
852 } |