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c6bb733d | 1 | /* Detection of Static Control Parts (SCoP) for Graphite. |
d353bf18 | 2 | Copyright (C) 2009-2015 Free Software Foundation, Inc. |
c6bb733d | 3 | Contributed by Sebastian Pop <sebastian.pop@amd.com> and |
4 | Tobias Grosser <grosser@fim.uni-passau.de>. | |
5 | ||
6 | This file is part of GCC. | |
7 | ||
8 | GCC is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 3, or (at your option) | |
11 | any later version. | |
12 | ||
13 | GCC is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with GCC; see the file COPYING3. If not see | |
20 | <http://www.gnu.org/licenses/>. */ | |
21 | ||
22 | #include "config.h" | |
87e20041 | 23 | |
429cca51 | 24 | #ifdef HAVE_isl |
40bdfbcc | 25 | /* Workaround for GMP 5.1.3 bug, see PR56019. */ |
26 | #include <stddef.h> | |
27 | ||
a26dad6a | 28 | #include <isl/constraint.h> |
87e20041 | 29 | #include <isl/set.h> |
30 | #include <isl/map.h> | |
31 | #include <isl/union_map.h> | |
87e20041 | 32 | |
c6bb733d | 33 | #include "system.h" |
34 | #include "coretypes.h" | |
9ef16211 | 35 | #include "backend.h" |
d040a5b0 | 36 | #include "cfghooks.h" |
edbec012 | 37 | #include "domwalk.h" |
7eb20e71 | 38 | #include "params.h" |
b20a8bb4 | 39 | #include "tree.h" |
9ef16211 | 40 | #include "gimple.h" |
9ef16211 | 41 | #include "ssa.h" |
9ef16211 | 42 | #include "fold-const.h" |
dcf1a1ec | 43 | #include "gimple-iterator.h" |
edbec012 | 44 | #include "tree-cfg.h" |
05d9c18a | 45 | #include "tree-ssa-loop-manip.h" |
46 | #include "tree-ssa-loop-niter.h" | |
073c1fd5 | 47 | #include "tree-ssa-loop.h" |
48 | #include "tree-into-ssa.h" | |
69ee5dbb | 49 | #include "tree-ssa.h" |
c6bb733d | 50 | #include "cfgloop.h" |
c6bb733d | 51 | #include "tree-data-ref.h" |
52 | #include "tree-scalar-evolution.h" | |
53 | #include "tree-pass.h" | |
c6bb733d | 54 | #include "graphite-poly.h" |
26bd1f19 | 55 | #include "tree-ssa-propagate.h" |
c6bb733d | 56 | #include "graphite-scop-detection.h" |
4773ab25 | 57 | #include "gimple-pretty-print.h" |
c6bb733d | 58 | |
edbec012 | 59 | class debug_printer |
60 | { | |
61 | private: | |
62 | FILE *dump_file; | |
63 | ||
64 | public: | |
65 | void | |
66 | set_dump_file (FILE *f) | |
67 | { | |
68 | gcc_assert (f); | |
69 | dump_file = f; | |
70 | } | |
71 | ||
72 | friend debug_printer & | |
73 | operator<< (debug_printer &output, int i) | |
74 | { | |
75 | fprintf (output.dump_file, "%d", i); | |
76 | return output; | |
77 | } | |
78 | friend debug_printer & | |
79 | operator<< (debug_printer &output, const char *s) | |
80 | { | |
81 | fprintf (output.dump_file, "%s", s); | |
82 | return output; | |
83 | } | |
84 | } dp; | |
85 | ||
86 | #define DEBUG_PRINT(args) do \ | |
87 | { \ | |
88 | if (dump_file && (dump_flags & TDF_DETAILS)) { args; } \ | |
89 | } while (0); | |
90 | ||
e057353f | 91 | /* Pretty print to FILE all the SCoPs in DOT format and mark them with |
92 | different colors. If there are not enough colors, paint the | |
93 | remaining SCoPs in gray. | |
94 | ||
95 | Special nodes: | |
96 | - "*" after the node number denotes the entry of a SCoP, | |
97 | - "#" after the node number denotes the exit of a SCoP, | |
98 | - "()" around the node number denotes the entry or the | |
99 | exit nodes of the SCOP. These are not part of SCoP. */ | |
100 | ||
101 | static void | |
102 | dot_all_scops_1 (FILE *file, vec<scop_p> scops) | |
103 | { | |
104 | basic_block bb; | |
105 | edge e; | |
106 | edge_iterator ei; | |
107 | scop_p scop; | |
108 | const char *color; | |
109 | int i; | |
110 | ||
111 | /* Disable debugging while printing graph. */ | |
112 | int tmp_dump_flags = dump_flags; | |
113 | dump_flags = 0; | |
114 | ||
115 | fprintf (file, "digraph all {\n"); | |
116 | ||
117 | FOR_ALL_BB_FN (bb, cfun) | |
118 | { | |
119 | int part_of_scop = false; | |
120 | ||
121 | /* Use HTML for every bb label. So we are able to print bbs | |
122 | which are part of two different SCoPs, with two different | |
123 | background colors. */ | |
124 | fprintf (file, "%d [label=<\n <TABLE BORDER=\"0\" CELLBORDER=\"1\" ", | |
125 | bb->index); | |
126 | fprintf (file, "CELLSPACING=\"0\">\n"); | |
127 | ||
128 | /* Select color for SCoP. */ | |
129 | FOR_EACH_VEC_ELT (scops, i, scop) | |
130 | { | |
131 | sese_l region = scop->scop_info->region; | |
132 | if (bb_in_sese_p (bb, region) || (region.exit->dest == bb) | |
133 | || (region.entry->dest == bb)) | |
134 | { | |
135 | switch (i % 17) | |
136 | { | |
137 | case 0: /* red */ | |
138 | color = "#e41a1c"; | |
139 | break; | |
140 | case 1: /* blue */ | |
141 | color = "#377eb8"; | |
142 | break; | |
143 | case 2: /* green */ | |
144 | color = "#4daf4a"; | |
145 | break; | |
146 | case 3: /* purple */ | |
147 | color = "#984ea3"; | |
148 | break; | |
149 | case 4: /* orange */ | |
150 | color = "#ff7f00"; | |
151 | break; | |
152 | case 5: /* yellow */ | |
153 | color = "#ffff33"; | |
154 | break; | |
155 | case 6: /* brown */ | |
156 | color = "#a65628"; | |
157 | break; | |
158 | case 7: /* rose */ | |
159 | color = "#f781bf"; | |
160 | break; | |
161 | case 8: | |
162 | color = "#8dd3c7"; | |
163 | break; | |
164 | case 9: | |
165 | color = "#ffffb3"; | |
166 | break; | |
167 | case 10: | |
168 | color = "#bebada"; | |
169 | break; | |
170 | case 11: | |
171 | color = "#fb8072"; | |
172 | break; | |
173 | case 12: | |
174 | color = "#80b1d3"; | |
175 | break; | |
176 | case 13: | |
177 | color = "#fdb462"; | |
178 | break; | |
179 | case 14: | |
180 | color = "#b3de69"; | |
181 | break; | |
182 | case 15: | |
183 | color = "#fccde5"; | |
184 | break; | |
185 | case 16: | |
186 | color = "#bc80bd"; | |
187 | break; | |
188 | default: /* gray */ | |
189 | color = "#999999"; | |
190 | } | |
191 | ||
192 | fprintf (file, " <TR><TD WIDTH=\"50\" BGCOLOR=\"%s\">", | |
193 | color); | |
194 | ||
195 | if (!bb_in_sese_p (bb, region)) | |
196 | fprintf (file, " ("); | |
197 | ||
198 | if (bb == region.entry->dest && bb == region.exit->dest) | |
199 | fprintf (file, " %d*# ", bb->index); | |
200 | else if (bb == region.entry->dest) | |
201 | fprintf (file, " %d* ", bb->index); | |
202 | else if (bb == region.exit->dest) | |
203 | fprintf (file, " %d# ", bb->index); | |
204 | else | |
205 | fprintf (file, " %d ", bb->index); | |
206 | ||
207 | fprintf (file, "{lp_%d}", bb->loop_father->num); | |
208 | ||
209 | if (!bb_in_sese_p (bb, region)) | |
210 | fprintf (file, ")"); | |
211 | ||
212 | fprintf (file, "</TD></TR>\n"); | |
213 | part_of_scop = true; | |
214 | } | |
215 | } | |
216 | ||
217 | if (!part_of_scop) | |
218 | { | |
219 | fprintf (file, " <TR><TD WIDTH=\"50\" BGCOLOR=\"#ffffff\">"); | |
220 | fprintf (file, " %d {lp_%d} </TD></TR>\n", bb->index, | |
221 | bb->loop_father->num); | |
222 | } | |
223 | fprintf (file, " </TABLE>>, shape=box, style=\"setlinewidth(0)\"]\n"); | |
224 | } | |
225 | ||
226 | FOR_ALL_BB_FN (bb, cfun) | |
227 | { | |
228 | FOR_EACH_EDGE (e, ei, bb->succs) | |
229 | fprintf (file, "%d -> %d;\n", bb->index, e->dest->index); | |
230 | } | |
231 | ||
232 | fputs ("}\n\n", file); | |
233 | ||
234 | /* Enable debugging again. */ | |
235 | dump_flags = tmp_dump_flags; | |
236 | } | |
237 | ||
238 | /* Display all SCoPs using dotty. */ | |
239 | ||
240 | DEBUG_FUNCTION void | |
241 | dot_all_scops (vec<scop_p> scops) | |
242 | { | |
243 | /* When debugging, enable the following code. This cannot be used | |
244 | in production compilers because it calls "system". */ | |
245 | #if 0 | |
246 | int x; | |
247 | FILE *stream = fopen ("/tmp/allscops.dot", "w"); | |
248 | gcc_assert (stream); | |
249 | ||
250 | dot_all_scops_1 (stream, scops); | |
251 | fclose (stream); | |
252 | ||
253 | x = system ("dotty /tmp/allscops.dot &"); | |
254 | #else | |
255 | dot_all_scops_1 (stderr, scops); | |
256 | #endif | |
257 | } | |
258 | ||
259 | /* Display all SCoPs using dotty. */ | |
260 | ||
261 | DEBUG_FUNCTION void | |
262 | dot_scop (scop_p scop) | |
263 | { | |
264 | auto_vec<scop_p, 1> scops; | |
265 | ||
266 | if (scop) | |
267 | scops.safe_push (scop); | |
268 | ||
269 | /* When debugging, enable the following code. This cannot be used | |
270 | in production compilers because it calls "system". */ | |
271 | #if 0 | |
272 | { | |
273 | int x; | |
274 | FILE *stream = fopen ("/tmp/allscops.dot", "w"); | |
275 | gcc_assert (stream); | |
276 | ||
277 | dot_all_scops_1 (stream, scops); | |
278 | fclose (stream); | |
279 | x = system ("dotty /tmp/allscops.dot &"); | |
280 | } | |
281 | #else | |
282 | dot_all_scops_1 (stderr, scops); | |
283 | #endif | |
284 | } | |
edbec012 | 285 | |
286 | /* Return true if BB is empty, contains only DEBUG_INSNs. */ | |
287 | ||
288 | static bool | |
289 | trivially_empty_bb_p (basic_block bb) | |
290 | { | |
291 | gimple_stmt_iterator gsi; | |
292 | ||
293 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
294 | if (gimple_code (gsi_stmt (gsi)) != GIMPLE_DEBUG) | |
295 | return false; | |
296 | ||
297 | return true; | |
298 | } | |
299 | ||
300 | /* Returns true when P1 and P2 are close phis with the same | |
301 | argument. */ | |
302 | ||
303 | static inline bool | |
304 | same_close_phi_node (gphi *p1, gphi *p2) | |
305 | { | |
306 | return operand_equal_p (gimple_phi_arg_def (p1, 0), | |
307 | gimple_phi_arg_def (p2, 0), 0); | |
308 | } | |
309 | ||
edbec012 | 310 | static void make_close_phi_nodes_unique (basic_block bb); |
311 | ||
312 | /* Remove the close phi node at GSI and replace its rhs with the rhs | |
313 | of PHI. */ | |
314 | ||
315 | static void | |
316 | remove_duplicate_close_phi (gphi *phi, gphi_iterator *gsi) | |
317 | { | |
318 | gimple *use_stmt; | |
319 | use_operand_p use_p; | |
320 | imm_use_iterator imm_iter; | |
321 | tree res = gimple_phi_result (phi); | |
322 | tree def = gimple_phi_result (gsi->phi ()); | |
323 | ||
324 | gcc_assert (same_close_phi_node (phi, gsi->phi ())); | |
325 | ||
326 | FOR_EACH_IMM_USE_STMT (use_stmt, imm_iter, def) | |
327 | { | |
328 | FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter) | |
329 | SET_USE (use_p, res); | |
330 | ||
331 | update_stmt (use_stmt); | |
332 | ||
333 | /* It is possible that we just created a duplicate close-phi | |
334 | for an already-processed containing loop. Check for this | |
335 | case and clean it up. */ | |
336 | if (gimple_code (use_stmt) == GIMPLE_PHI | |
337 | && gimple_phi_num_args (use_stmt) == 1) | |
338 | make_close_phi_nodes_unique (gimple_bb (use_stmt)); | |
339 | } | |
340 | ||
341 | remove_phi_node (gsi, true); | |
342 | } | |
343 | ||
344 | /* Removes all the close phi duplicates from BB. */ | |
345 | ||
346 | static void | |
347 | make_close_phi_nodes_unique (basic_block bb) | |
348 | { | |
349 | gphi_iterator psi; | |
350 | ||
351 | for (psi = gsi_start_phis (bb); !gsi_end_p (psi); gsi_next (&psi)) | |
352 | { | |
353 | gphi_iterator gsi = psi; | |
354 | gphi *phi = psi.phi (); | |
355 | ||
356 | /* At this point, PHI should be a close phi in normal form. */ | |
357 | gcc_assert (gimple_phi_num_args (phi) == 1); | |
358 | ||
359 | /* Iterate over the next phis and remove duplicates. */ | |
360 | gsi_next (&gsi); | |
361 | while (!gsi_end_p (gsi)) | |
362 | if (same_close_phi_node (phi, gsi.phi ())) | |
363 | remove_duplicate_close_phi (phi, &gsi); | |
364 | else | |
365 | gsi_next (&gsi); | |
366 | } | |
367 | } | |
368 | ||
369 | /* Transforms LOOP to the canonical loop closed SSA form. */ | |
370 | ||
371 | static void | |
372 | canonicalize_loop_closed_ssa (loop_p loop) | |
373 | { | |
374 | edge e = single_exit (loop); | |
375 | basic_block bb; | |
376 | ||
377 | if (!e || e->flags & EDGE_ABNORMAL) | |
378 | return; | |
379 | ||
380 | bb = e->dest; | |
381 | ||
382 | if (single_pred_p (bb)) | |
383 | { | |
384 | e = split_block_after_labels (bb); | |
385 | DEBUG_PRINT (dp << "\nSplitting bb_" << bb->index); | |
386 | make_close_phi_nodes_unique (e->src); | |
387 | } | |
388 | else | |
389 | { | |
390 | gphi_iterator psi; | |
391 | basic_block close = split_edge (e); | |
392 | ||
393 | e = single_succ_edge (close); | |
394 | DEBUG_PRINT (dp << "\nSplitting edge (" << e->src->index << "," | |
395 | << e->dest->index << ")\n"); | |
396 | ||
397 | for (psi = gsi_start_phis (bb); !gsi_end_p (psi); gsi_next (&psi)) | |
398 | { | |
399 | gphi *phi = psi.phi (); | |
400 | unsigned i; | |
401 | ||
402 | for (i = 0; i < gimple_phi_num_args (phi); i++) | |
403 | if (gimple_phi_arg_edge (phi, i) == e) | |
404 | { | |
405 | tree res, arg = gimple_phi_arg_def (phi, i); | |
406 | use_operand_p use_p; | |
407 | gphi *close_phi; | |
408 | ||
409 | if (TREE_CODE (arg) != SSA_NAME) | |
410 | continue; | |
411 | ||
412 | close_phi = create_phi_node (NULL_TREE, close); | |
413 | res = create_new_def_for (arg, close_phi, | |
414 | gimple_phi_result_ptr (close_phi)); | |
415 | add_phi_arg (close_phi, arg, | |
416 | gimple_phi_arg_edge (close_phi, 0), | |
417 | UNKNOWN_LOCATION); | |
418 | use_p = gimple_phi_arg_imm_use_ptr (phi, i); | |
419 | replace_exp (use_p, res); | |
420 | update_stmt (phi); | |
421 | } | |
422 | } | |
423 | ||
424 | make_close_phi_nodes_unique (close); | |
425 | } | |
426 | ||
427 | /* The code above does not properly handle changes in the post dominance | |
428 | information (yet). */ | |
429 | recompute_all_dominators (); | |
430 | } | |
431 | ||
432 | /* Converts the current loop closed SSA form to a canonical form | |
433 | expected by the Graphite code generation. | |
434 | ||
435 | The loop closed SSA form has the following invariant: a variable | |
436 | defined in a loop that is used outside the loop appears only in the | |
437 | phi nodes in the destination of the loop exit. These phi nodes are | |
438 | called close phi nodes. | |
439 | ||
440 | The canonical loop closed SSA form contains the extra invariants: | |
441 | ||
442 | - when the loop contains only one exit, the close phi nodes contain | |
443 | only one argument. That implies that the basic block that contains | |
444 | the close phi nodes has only one predecessor, that is a basic block | |
445 | in the loop. | |
446 | ||
447 | - the basic block containing the close phi nodes does not contain | |
448 | other statements. | |
449 | ||
450 | - there exist only one phi node per definition in the loop. | |
451 | */ | |
452 | ||
453 | static void | |
454 | canonicalize_loop_closed_ssa_form (void) | |
455 | { | |
382ecba7 | 456 | checking_verify_loop_closed_ssa (true); |
edbec012 | 457 | |
382ecba7 | 458 | loop_p loop; |
edbec012 | 459 | FOR_EACH_LOOP (loop, 0) |
460 | canonicalize_loop_closed_ssa (loop); | |
461 | ||
462 | rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa); | |
463 | update_ssa (TODO_update_ssa); | |
464 | ||
382ecba7 | 465 | checking_verify_loop_closed_ssa (true); |
edbec012 | 466 | } |
467 | ||
468 | /* Can all ivs be represented by a signed integer? | |
469 | As ISL might generate negative values in its expressions, signed loop ivs | |
470 | are required in the backend. */ | |
471 | ||
472 | static bool | |
473 | loop_ivs_can_be_represented (loop_p loop) | |
474 | { | |
475 | unsigned type_long_long = TYPE_PRECISION (long_long_integer_type_node); | |
476 | for (gphi_iterator psi = gsi_start_phis (loop->header); !gsi_end_p (psi); | |
477 | gsi_next (&psi)) | |
478 | { | |
479 | gphi *phi = psi.phi (); | |
480 | tree res = PHI_RESULT (phi); | |
481 | tree type = TREE_TYPE (res); | |
482 | ||
483 | if (TYPE_UNSIGNED (type) && TYPE_PRECISION (type) >= type_long_long) | |
484 | return false; | |
485 | } | |
486 | ||
487 | return true; | |
488 | } | |
489 | ||
490 | /* Returns a COND_EXPR statement when BB has a single predecessor, the | |
491 | edge between BB and its predecessor is not a loop exit edge, and | |
492 | the last statement of the single predecessor is a COND_EXPR. */ | |
493 | ||
494 | static gcond * | |
495 | single_pred_cond_non_loop_exit (basic_block bb) | |
496 | { | |
497 | if (single_pred_p (bb)) | |
498 | { | |
499 | edge e = single_pred_edge (bb); | |
500 | basic_block pred = e->src; | |
501 | gimple *stmt; | |
502 | ||
503 | if (loop_depth (pred->loop_father) > loop_depth (bb->loop_father)) | |
504 | return NULL; | |
505 | ||
506 | stmt = last_stmt (pred); | |
507 | ||
508 | if (stmt && gimple_code (stmt) == GIMPLE_COND) | |
509 | return as_a<gcond *> (stmt); | |
510 | } | |
511 | ||
512 | return NULL; | |
513 | } | |
514 | ||
515 | namespace | |
516 | { | |
517 | ||
518 | /* Build the maximal scop containing LOOPs and add it to SCOPS. */ | |
519 | ||
520 | class scop_detection | |
521 | { | |
522 | public: | |
523 | scop_detection () : scops (vNULL) {} | |
524 | ||
525 | /* A marker for invalid sese_l. */ | |
526 | static sese_l invalid_sese; | |
527 | ||
528 | /* Return the SCOPS in this SCOP_DETECTION. */ | |
529 | ||
530 | vec<sese_l> | |
531 | get_scops () | |
532 | { | |
533 | return scops; | |
534 | } | |
535 | ||
536 | /* Return an sese_l around the LOOP. */ | |
537 | ||
538 | sese_l get_sese (loop_p loop); | |
539 | ||
540 | /* Return the closest dominator with a single entry edge. In case of a | |
541 | back-loop the back-edge is not counted. */ | |
542 | ||
543 | static edge get_nearest_dom_with_single_entry (basic_block dom); | |
544 | ||
545 | /* Return the closest post-dominator with a single exit edge. In case of a | |
546 | back-loop the back-edge is not counted. */ | |
547 | ||
548 | static edge get_nearest_pdom_with_single_exit (basic_block dom); | |
549 | ||
550 | /* Print S to FILE. */ | |
551 | ||
552 | static void print_sese (FILE *file, sese_l s); | |
553 | ||
554 | /* Merge scops at same loop depth and returns the new sese. | |
555 | Returns a new SESE when merge was successful, INVALID_SESE otherwise. */ | |
556 | ||
557 | sese_l merge_sese (sese_l first, sese_l second) const; | |
558 | ||
559 | /* Build scop outer->inner if possible. */ | |
560 | ||
561 | sese_l build_scop_depth (sese_l s, loop_p loop); | |
562 | ||
563 | /* If loop and loop->next are valid scops, try to merge them. */ | |
564 | ||
565 | sese_l build_scop_breadth (sese_l s1, loop_p loop); | |
566 | ||
567 | /* Return true when LOOP is a valid scop, that is a Static Control Part, a | |
568 | region of code that can be represented in the polyhedral model. SCOP | |
569 | defines the region we analyse. */ | |
570 | ||
571 | bool loop_is_valid_scop (loop_p loop, sese_l scop) const; | |
572 | ||
573 | /* Return true when BEGIN is the preheader edge of a loop with a single exit | |
574 | END. */ | |
575 | ||
576 | static bool region_has_one_loop (sese_l s); | |
577 | ||
578 | /* Add to SCOPS a scop starting at SCOP_BEGIN and ending at SCOP_END. */ | |
579 | ||
580 | void add_scop (sese_l s); | |
581 | ||
582 | /* Returns true if S1 subsumes/surrounds S2. */ | |
583 | static bool subsumes (sese_l s1, sese_l s2); | |
584 | ||
585 | /* Remove a SCoP which is subsumed by S1. */ | |
586 | void remove_subscops (sese_l s1); | |
587 | ||
588 | /* Returns true if S1 intersects with S2. Since we already know that S1 does | |
589 | not subsume S2 or vice-versa, we only check for entry bbs. */ | |
590 | ||
591 | static bool intersects (sese_l s1, sese_l s2); | |
592 | ||
593 | /* Remove one of the scops when it intersects with any other. */ | |
594 | ||
595 | void remove_intersecting_scops (sese_l s1); | |
596 | ||
597 | /* Return true when the body of LOOP has statements that can be represented | |
598 | as a valid scop. */ | |
599 | ||
600 | bool loop_body_is_valid_scop (loop_p loop, sese_l scop) const; | |
601 | ||
602 | /* Return true when BB contains a harmful operation for a scop: that | |
603 | can be a function call with side effects, the induction variables | |
604 | are not linear with respect to SCOP, etc. The current open | |
605 | scop should end before this statement. */ | |
606 | ||
607 | bool harmful_stmt_in_bb (sese_l scop, basic_block bb) const; | |
608 | ||
609 | /* Return true when a statement in SCOP cannot be represented by Graphite. | |
610 | The assumptions are that L1 dominates L2, and SCOP->entry dominates L1. | |
611 | Limit the number of bbs between adjacent loops to | |
612 | PARAM_SCOP_MAX_NUM_BBS_BETWEEN_LOOPS. */ | |
613 | ||
614 | bool harmful_stmt_in_region (sese_l scop) const; | |
615 | ||
616 | /* Return true only when STMT is simple enough for being handled by Graphite. | |
617 | This depends on SCOP, as the parameters are initialized relatively to | |
618 | this basic block, the linear functions are initialized based on the | |
619 | outermost loop containing STMT inside the SCOP. BB is the place where we | |
620 | try to evaluate the STMT. */ | |
621 | ||
622 | bool stmt_simple_for_scop_p (sese_l scop, gimple *stmt, | |
623 | basic_block bb) const; | |
624 | ||
625 | /* Something like "n * m" is not allowed. */ | |
626 | ||
627 | static bool graphite_can_represent_init (tree e); | |
628 | ||
629 | /* Return true when SCEV can be represented in the polyhedral model. | |
630 | ||
631 | An expression can be represented, if it can be expressed as an | |
632 | affine expression. For loops (i, j) and parameters (m, n) all | |
633 | affine expressions are of the form: | |
634 | ||
635 | x1 * i + x2 * j + x3 * m + x4 * n + x5 * 1 where x1..x5 element of Z | |
636 | ||
637 | 1 i + 20 j + (-2) m + 25 | |
638 | ||
639 | Something like "i * n" or "n * m" is not allowed. */ | |
640 | ||
641 | static bool graphite_can_represent_scev (tree scev); | |
642 | ||
643 | /* Return true when EXPR can be represented in the polyhedral model. | |
644 | ||
645 | This means an expression can be represented, if it is linear with respect | |
646 | to the loops and the strides are non parametric. LOOP is the place where | |
647 | the expr will be evaluated. SCOP defines the region we analyse. */ | |
648 | ||
649 | static bool graphite_can_represent_expr (sese_l scop, loop_p loop, | |
650 | tree expr); | |
651 | ||
652 | /* Return true if the data references of STMT can be represented by Graphite. | |
653 | We try to analyze the data references in a loop contained in the SCOP. */ | |
654 | ||
655 | static bool stmt_has_simple_data_refs_p (sese_l scop, gimple *stmt); | |
656 | ||
657 | /* Remove the close phi node at GSI and replace its rhs with the rhs | |
658 | of PHI. */ | |
659 | ||
660 | static void remove_duplicate_close_phi (gphi *phi, gphi_iterator *gsi); | |
661 | ||
662 | /* Returns true when Graphite can represent LOOP in SCOP. | |
663 | FIXME: For the moment, graphite cannot be used on loops that iterate using | |
664 | induction variables that wrap. */ | |
665 | ||
666 | static bool can_represent_loop_1 (loop_p loop, sese_l scop); | |
667 | ||
668 | /* Return true when all the loops within LOOP can be represented by | |
669 | Graphite. */ | |
670 | ||
671 | static bool can_represent_loop (loop_p loop, sese_l scop); | |
672 | ||
edbec012 | 673 | /* Returns the number of pbbs that are in loops contained in SCOP. */ |
674 | ||
675 | static int nb_pbbs_in_loops (scop_p scop); | |
676 | ||
677 | static bool graphite_can_represent_stmt (sese_l, gimple *, basic_block); | |
678 | ||
679 | private: | |
680 | vec<sese_l> scops; | |
681 | }; | |
682 | ||
5828c94d | 683 | sese_l scop_detection::invalid_sese (NULL, NULL); |
edbec012 | 684 | |
685 | /* Return an sese_l around the LOOP. */ | |
686 | ||
687 | sese_l | |
688 | scop_detection::get_sese (loop_p loop) | |
689 | { | |
690 | if (!loop) | |
691 | return invalid_sese; | |
692 | ||
693 | if (!loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS)) | |
694 | return invalid_sese; | |
695 | edge scop_end = single_exit (loop); | |
696 | if (!scop_end) | |
697 | return invalid_sese; | |
698 | edge scop_begin = loop_preheader_edge (loop); | |
699 | sese_l s (scop_begin, scop_end); | |
700 | return s; | |
701 | } | |
702 | ||
703 | /* Return the closest dominator with a single entry edge. */ | |
704 | ||
705 | edge | |
706 | scop_detection::get_nearest_dom_with_single_entry (basic_block dom) | |
707 | { | |
708 | if (!dom->preds) | |
709 | return NULL; | |
710 | /* If e1->src dominates e2->src then e1->src will also dominate dom. */ | |
711 | if (dom->preds->length () == 2) | |
712 | { | |
713 | edge e1 = (*dom->preds)[0]; | |
714 | edge e2 = (*dom->preds)[1]; | |
715 | if (dominated_by_p (CDI_DOMINATORS, e2->src, e1->src)) | |
716 | return e1; | |
717 | if (dominated_by_p (CDI_DOMINATORS, e1->src, e2->src)) | |
718 | return e2; | |
719 | } | |
720 | ||
721 | while (dom->preds->length () != 1) | |
722 | { | |
723 | if (dom->preds->length () < 1) | |
724 | return NULL; | |
725 | dom = get_immediate_dominator (CDI_DOMINATORS, dom); | |
726 | if (!dom->preds) | |
727 | return NULL; | |
728 | } | |
729 | return (*dom->preds)[0]; | |
730 | } | |
731 | ||
732 | /* Return the closest post-dominator with a single exit edge. In case of a | |
733 | back-loop the back-edge is not counted. */ | |
734 | ||
735 | edge | |
736 | scop_detection::get_nearest_pdom_with_single_exit (basic_block dom) | |
737 | { | |
738 | if (!dom->succs) | |
739 | return NULL; | |
740 | if (dom->succs->length () == 2) | |
741 | { | |
742 | edge e1 = (*dom->succs)[0]; | |
743 | edge e2 = (*dom->succs)[1]; | |
744 | if (dominated_by_p (CDI_POST_DOMINATORS, e2->dest, e1->dest)) | |
745 | return e1; | |
746 | if (dominated_by_p (CDI_POST_DOMINATORS, e1->dest, e2->dest)) | |
747 | return e2; | |
748 | } | |
749 | ||
750 | while (dom->succs->length () != 1) | |
751 | { | |
752 | if (dom->succs->length () < 1) | |
753 | return NULL; | |
754 | dom = get_immediate_dominator (CDI_POST_DOMINATORS, dom); | |
755 | if (!dom->succs) | |
756 | return NULL; | |
757 | } | |
758 | return (*dom->succs)[0]; | |
759 | } | |
760 | ||
761 | /* Print S to FILE. */ | |
762 | ||
763 | void | |
764 | scop_detection::print_sese (FILE *file, sese_l s) | |
765 | { | |
766 | fprintf (file, "(entry_edge (bb_%d, bb_%d), exit_edge (bb_%d, bb_%d))\n", | |
767 | s.entry->src->index, s.entry->dest->index, | |
768 | s.exit->src->index, s.exit->dest->index); | |
769 | } | |
770 | ||
771 | /* Merge scops at same loop depth and returns the new sese. | |
772 | Returns a new SESE when merge was successful, INVALID_SESE otherwise. */ | |
773 | ||
774 | sese_l | |
775 | scop_detection::merge_sese (sese_l first, sese_l second) const | |
776 | { | |
777 | /* In the trivial case first/second may be NULL. */ | |
778 | if (!first) | |
779 | return second; | |
780 | if (!second) | |
781 | return first; | |
782 | ||
783 | DEBUG_PRINT (dp << "[try-merging-sese] s1: "; print_sese (dump_file, first); | |
784 | dp << "[try-merging-sese] s2: "; | |
785 | print_sese (dump_file, second)); | |
786 | ||
787 | /* Assumption: Both the sese's should be at the same loop depth or one scop | |
788 | should subsume the other like in case of nested loops. */ | |
789 | ||
790 | /* Find the common dominators for entry, | |
791 | and common post-dominators for the exit. */ | |
792 | basic_block dom = nearest_common_dominator (CDI_DOMINATORS, | |
f032380c | 793 | get_entry_bb (first), |
794 | get_entry_bb (second)); | |
edbec012 | 795 | |
796 | edge entry = get_nearest_dom_with_single_entry (dom); | |
9e3b8c11 | 797 | |
798 | if (!entry || (entry->flags & EDGE_IRREDUCIBLE_LOOP)) | |
edbec012 | 799 | return invalid_sese; |
800 | ||
801 | basic_block pdom = nearest_common_dominator (CDI_POST_DOMINATORS, | |
f032380c | 802 | get_exit_bb (first), |
803 | get_exit_bb (second)); | |
edbec012 | 804 | pdom = nearest_common_dominator (CDI_POST_DOMINATORS, dom, pdom); |
805 | ||
806 | edge exit = get_nearest_pdom_with_single_exit (pdom); | |
9e3b8c11 | 807 | |
808 | if (!exit || (exit->flags & EDGE_IRREDUCIBLE_LOOP)) | |
edbec012 | 809 | return invalid_sese; |
810 | ||
811 | sese_l combined (entry, exit); | |
812 | ||
813 | /* FIXME: We could iterate to find the dom which dominates pdom, and pdom | |
814 | which post-dominates dom, until it stabilizes. Also, ENTRY->SRC and | |
815 | EXIT->DEST should be in the same loop nest. */ | |
816 | if (!dominated_by_p (CDI_DOMINATORS, pdom, dom) | |
817 | || loop_depth (entry->src->loop_father) | |
818 | != loop_depth (exit->dest->loop_father)) | |
819 | return invalid_sese; | |
820 | ||
821 | /* For now we just want to bail out when exit does not post-dominate entry. | |
822 | TODO: We might just add a basic_block at the exit to make exit | |
823 | post-dominate entry (the entire region). */ | |
f032380c | 824 | if (!dominated_by_p (CDI_POST_DOMINATORS, get_entry_bb (combined), |
825 | get_exit_bb (combined)) | |
826 | || !dominated_by_p (CDI_DOMINATORS, get_exit_bb (combined), | |
827 | get_entry_bb (combined))) | |
edbec012 | 828 | { |
829 | DEBUG_PRINT (dp << "[scop-detection-fail] cannot merge seses.\n"); | |
830 | return invalid_sese; | |
831 | } | |
832 | ||
833 | /* FIXME: We should remove this piece of code once | |
834 | canonicalize_loop_closed_ssa has been removed, because that function | |
835 | adds a BB with single exit. */ | |
f032380c | 836 | if (!trivially_empty_bb_p (get_exit_bb (combined))) |
edbec012 | 837 | { |
838 | /* Find the first empty succ (with single exit) of combined.exit. */ | |
839 | basic_block imm_succ = combined.exit->dest; | |
840 | if (single_succ_p (imm_succ) && trivially_empty_bb_p (imm_succ)) | |
841 | combined.exit = single_succ_edge (imm_succ); | |
842 | else | |
843 | { | |
844 | DEBUG_PRINT (dp << "\n[scop-detection-fail] Discarding SCoP because " | |
845 | << "no single exit (empty succ) for sese exit"; | |
846 | print_sese (dump_file, combined)); | |
847 | return invalid_sese; | |
848 | } | |
849 | } | |
850 | ||
851 | /* Analyze all the BBs in new sese. */ | |
852 | if (harmful_stmt_in_region (combined)) | |
853 | return invalid_sese; | |
854 | ||
855 | DEBUG_PRINT (dp << "[merged-sese] s1: "; print_sese (dump_file, combined)); | |
856 | ||
857 | return combined; | |
858 | } | |
859 | ||
860 | /* Build scop outer->inner if possible. */ | |
861 | ||
862 | sese_l | |
863 | scop_detection::build_scop_depth (sese_l s, loop_p loop) | |
864 | { | |
865 | if (!loop) | |
866 | return s; | |
867 | ||
868 | DEBUG_PRINT (dp << "\n[Depth loop_" << loop->num << "]"); | |
869 | s = build_scop_depth (s, loop->inner); | |
870 | ||
871 | sese_l s2 = merge_sese (s, get_sese (loop)); | |
872 | if (!s2) | |
873 | { | |
874 | /* s might be a valid scop, so return it and start analyzing from the | |
875 | adjacent loop. */ | |
876 | build_scop_depth (invalid_sese, loop->next); | |
877 | return s; | |
878 | } | |
879 | ||
880 | if (!loop_is_valid_scop (loop, s2)) | |
881 | return build_scop_depth (invalid_sese, loop->next); | |
882 | ||
883 | return build_scop_breadth (s2, loop); | |
884 | } | |
885 | ||
886 | /* If loop and loop->next are valid scops, try to merge them. */ | |
887 | ||
888 | sese_l | |
889 | scop_detection::build_scop_breadth (sese_l s1, loop_p loop) | |
890 | { | |
891 | if (!loop) | |
892 | return s1; | |
893 | DEBUG_PRINT (dp << "\n[Breadth loop_" << loop->num << "]"); | |
894 | gcc_assert (s1); | |
895 | ||
896 | loop_p l = loop; | |
897 | sese_l s2 = build_scop_depth (invalid_sese, l->next); | |
898 | if (!s2) | |
899 | { | |
900 | if (s1) | |
901 | add_scop (s1); | |
902 | return s1; | |
903 | } | |
904 | ||
905 | sese_l combined = merge_sese (s1, s2); | |
906 | ||
907 | if (combined) | |
908 | s1 = combined; | |
909 | else | |
910 | add_scop (s2); | |
911 | ||
912 | if (s1) | |
913 | add_scop (s1); | |
914 | return s1; | |
915 | } | |
916 | ||
917 | /* Returns true when Graphite can represent LOOP in SCOP. | |
918 | FIXME: For the moment, graphite cannot be used on loops that iterate using | |
919 | induction variables that wrap. */ | |
920 | ||
921 | bool | |
922 | scop_detection::can_represent_loop_1 (loop_p loop, sese_l scop) | |
923 | { | |
924 | tree niter; | |
925 | struct tree_niter_desc niter_desc; | |
926 | ||
927 | return single_exit (loop) | |
9e3b8c11 | 928 | && !(loop_preheader_edge (loop)->flags & EDGE_IRREDUCIBLE_LOOP) |
edbec012 | 929 | && number_of_iterations_exit (loop, single_exit (loop), &niter_desc, false) |
930 | && niter_desc.control.no_overflow | |
931 | && (niter = number_of_latch_executions (loop)) | |
932 | && !chrec_contains_undetermined (niter) | |
933 | && graphite_can_represent_expr (scop, loop, niter); | |
934 | } | |
935 | ||
936 | /* Return true when all the loops within LOOP can be represented by | |
937 | Graphite. */ | |
938 | ||
939 | bool | |
940 | scop_detection::can_represent_loop (loop_p loop, sese_l scop) | |
941 | { | |
942 | if (!can_represent_loop_1 (loop, scop)) | |
943 | return false; | |
944 | if (loop->inner && !can_represent_loop (loop->inner, scop)) | |
945 | return false; | |
946 | if (loop->next && !can_represent_loop (loop->next, scop)) | |
947 | return false; | |
948 | ||
949 | return true; | |
950 | } | |
951 | ||
952 | /* Return true when LOOP is a valid scop, that is a Static Control Part, a | |
953 | region of code that can be represented in the polyhedral model. SCOP | |
954 | defines the region we analyse. */ | |
955 | ||
956 | bool | |
957 | scop_detection::loop_is_valid_scop (loop_p loop, sese_l scop) const | |
958 | { | |
959 | if (!scop) | |
960 | return false; | |
961 | ||
76fd4c50 | 962 | if (!optimize_loop_nest_for_speed_p (loop)) |
963 | { | |
964 | DEBUG_PRINT (dp << "[scop-detection-fail] loop_" | |
965 | << loop->num << " is not on a hot path.\n"); | |
966 | return false; | |
967 | } | |
968 | ||
edbec012 | 969 | if (!can_represent_loop (loop, scop)) |
970 | { | |
971 | DEBUG_PRINT (dp << "[scop-detection-fail] cannot represent loop_" | |
972 | << loop->num << "\n"); | |
973 | return false; | |
974 | } | |
975 | ||
976 | if (loop_body_is_valid_scop (loop, scop)) | |
977 | { | |
978 | DEBUG_PRINT (dp << "[valid-scop] loop_" << loop->num | |
979 | << "is a valid scop.\n"); | |
980 | return true; | |
981 | } | |
982 | return false; | |
983 | } | |
984 | ||
985 | /* Return true when BEGIN is the preheader edge of a loop with a single exit | |
986 | END. */ | |
987 | ||
988 | bool | |
989 | scop_detection::region_has_one_loop (sese_l s) | |
990 | { | |
991 | edge begin = s.entry; | |
992 | edge end = s.exit; | |
993 | /* Check for a single perfectly nested loop. */ | |
994 | if (begin->dest->loop_father->inner) | |
995 | return false; | |
996 | ||
997 | /* Otherwise, check whether we have adjacent loops. */ | |
998 | return begin->dest->loop_father == end->src->loop_father; | |
999 | } | |
1000 | ||
1001 | /* Add to SCOPS a scop starting at SCOP_BEGIN and ending at SCOP_END. */ | |
1002 | ||
1003 | void | |
1004 | scop_detection::add_scop (sese_l s) | |
1005 | { | |
1006 | gcc_assert (s); | |
1007 | ||
1008 | /* Do not add scops with only one loop. */ | |
1009 | if (region_has_one_loop (s)) | |
1010 | { | |
1011 | DEBUG_PRINT (dp << "\n[scop-detection-fail] Discarding one loop SCoP"; | |
1012 | print_sese (dump_file, s)); | |
1013 | return; | |
1014 | } | |
1015 | ||
f032380c | 1016 | if (get_exit_bb (s) == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
edbec012 | 1017 | { |
1018 | DEBUG_PRINT (dp << "\n[scop-detection-fail] " | |
1019 | << "Discarding SCoP exiting to return"; | |
1020 | print_sese (dump_file, s)); | |
1021 | return; | |
1022 | } | |
1023 | ||
1024 | /* Remove all the scops which are subsumed by s. */ | |
1025 | remove_subscops (s); | |
1026 | ||
1027 | /* Replace this with split-intersecting scops. */ | |
1028 | remove_intersecting_scops (s); | |
c6bb733d | 1029 | |
edbec012 | 1030 | scops.safe_push (s); |
1031 | DEBUG_PRINT (dp << "\nAdding SCoP "; print_sese (dump_file, s)); | |
7eb20e71 | 1032 | } |
c6bb733d | 1033 | |
edbec012 | 1034 | /* Return true when a statement in SCOP cannot be represented by Graphite. |
1035 | The assumptions are that L1 dominates L2, and SCOP->entry dominates L1. | |
1036 | Limit the number of bbs between adjacent loops to | |
1037 | PARAM_SCOP_MAX_NUM_BBS_BETWEEN_LOOPS. */ | |
1038 | ||
1039 | bool | |
1040 | scop_detection::harmful_stmt_in_region (sese_l scop) const | |
c6bb733d | 1041 | { |
f032380c | 1042 | basic_block exit_bb = get_exit_bb (scop); |
1043 | basic_block entry_bb = get_entry_bb (scop); | |
c6bb733d | 1044 | |
edbec012 | 1045 | DEBUG_PRINT (dp << "\n[checking-harmful-bbs] "; |
1046 | print_sese (dump_file, scop)); | |
1047 | gcc_assert (dominated_by_p (CDI_DOMINATORS, exit_bb, entry_bb)); | |
c6bb733d | 1048 | |
edbec012 | 1049 | int depth = bb_dom_dfs_in (CDI_DOMINATORS, exit_bb) |
1050 | - bb_dom_dfs_in (CDI_DOMINATORS, entry_bb); | |
c6bb733d | 1051 | |
edbec012 | 1052 | gcc_assert (depth > 0); |
c6bb733d | 1053 | |
edbec012 | 1054 | vec<basic_block> dom |
1055 | = get_dominated_to_depth (CDI_DOMINATORS, entry_bb, depth); | |
1056 | int i; | |
1057 | basic_block bb; | |
1058 | FOR_EACH_VEC_ELT (dom, i, bb) | |
1059 | { | |
1060 | DEBUG_PRINT (dp << "\nVisiting bb_" << bb->index); | |
c6bb733d | 1061 | |
edbec012 | 1062 | /* We don't want to analyze any bb outside sese. */ |
1063 | if (!dominated_by_p (CDI_POST_DOMINATORS, bb, exit_bb)) | |
1064 | continue; | |
1065 | ||
9e3b8c11 | 1066 | /* The basic block should not be part of an irreducible loop. */ |
1067 | if (bb->flags & BB_IRREDUCIBLE_LOOP) | |
1068 | return true; | |
1069 | ||
edbec012 | 1070 | if (harmful_stmt_in_bb (scop, bb)) |
1071 | return true; | |
1072 | } | |
1073 | ||
1074 | return false; | |
1075 | } | |
1076 | ||
1077 | /* Returns true if S1 subsumes/surrounds S2. */ | |
1078 | bool | |
1079 | scop_detection::subsumes (sese_l s1, sese_l s2) | |
c6bb733d | 1080 | { |
f032380c | 1081 | if (dominated_by_p (CDI_DOMINATORS, get_entry_bb (s2), |
1082 | get_entry_bb (s1)) | |
1083 | && dominated_by_p (CDI_POST_DOMINATORS, s2.exit->dest, | |
1084 | s1.exit->dest)) | |
edbec012 | 1085 | return true; |
1086 | return false; | |
1087 | } | |
c6bb733d | 1088 | |
edbec012 | 1089 | /* Remove a SCoP which is subsumed by S1. */ |
1090 | void | |
1091 | scop_detection::remove_subscops (sese_l s1) | |
1092 | { | |
1093 | int j; | |
5828c94d | 1094 | sese_l *s2; |
edbec012 | 1095 | FOR_EACH_VEC_ELT_REVERSE (scops, j, s2) |
1096 | { | |
5828c94d | 1097 | if (subsumes (s1, *s2)) |
edbec012 | 1098 | { |
1099 | DEBUG_PRINT (dp << "\nRemoving sub-SCoP"; | |
5828c94d | 1100 | print_sese (dump_file, *s2)); |
edbec012 | 1101 | scops.unordered_remove (j); |
1102 | } | |
1103 | } | |
1104 | } | |
c6bb733d | 1105 | |
edbec012 | 1106 | /* Returns true if S1 intersects with S2. Since we already know that S1 does |
1107 | not subsume S2 or vice-versa, we only check for entry bbs. */ | |
1108 | ||
1109 | bool | |
1110 | scop_detection::intersects (sese_l s1, sese_l s2) | |
1111 | { | |
f032380c | 1112 | if (dominated_by_p (CDI_DOMINATORS, get_entry_bb (s2), |
1113 | get_entry_bb (s1)) | |
1114 | && !dominated_by_p (CDI_DOMINATORS, get_entry_bb (s2), | |
1115 | get_exit_bb (s1))) | |
edbec012 | 1116 | return true; |
1117 | if ((s1.exit == s2.entry) || (s2.exit == s1.entry)) | |
1118 | return true; | |
1119 | ||
1120 | return false; | |
c6bb733d | 1121 | } |
1122 | ||
edbec012 | 1123 | /* Remove one of the scops when it intersects with any other. */ |
7eb20e71 | 1124 | |
edbec012 | 1125 | void |
1126 | scop_detection::remove_intersecting_scops (sese_l s1) | |
1127 | { | |
1128 | int j; | |
5828c94d | 1129 | sese_l *s2; |
edbec012 | 1130 | FOR_EACH_VEC_ELT_REVERSE (scops, j, s2) |
1131 | { | |
5828c94d | 1132 | if (intersects (s1, *s2)) |
edbec012 | 1133 | { |
1134 | DEBUG_PRINT (dp << "\nRemoving intersecting SCoP"; | |
5828c94d | 1135 | print_sese (dump_file, *s2); dp << "Intersects with:"; |
edbec012 | 1136 | print_sese (dump_file, s1)); |
1137 | scops.unordered_remove (j); | |
1138 | } | |
1139 | } | |
1140 | } | |
7eb20e71 | 1141 | |
c6bb733d | 1142 | /* Something like "n * m" is not allowed. */ |
1143 | ||
edbec012 | 1144 | bool |
1145 | scop_detection::graphite_can_represent_init (tree e) | |
c6bb733d | 1146 | { |
1147 | switch (TREE_CODE (e)) | |
1148 | { | |
1149 | case POLYNOMIAL_CHREC: | |
1150 | return graphite_can_represent_init (CHREC_LEFT (e)) | |
1151 | && graphite_can_represent_init (CHREC_RIGHT (e)); | |
1152 | ||
1153 | case MULT_EXPR: | |
1154 | if (chrec_contains_symbols (TREE_OPERAND (e, 0))) | |
7464e753 | 1155 | return graphite_can_represent_init (TREE_OPERAND (e, 0)) |
35ec552a | 1156 | && tree_fits_shwi_p (TREE_OPERAND (e, 1)); |
c6bb733d | 1157 | else |
7464e753 | 1158 | return graphite_can_represent_init (TREE_OPERAND (e, 1)) |
35ec552a | 1159 | && tree_fits_shwi_p (TREE_OPERAND (e, 0)); |
c6bb733d | 1160 | |
1161 | case PLUS_EXPR: | |
1162 | case POINTER_PLUS_EXPR: | |
1163 | case MINUS_EXPR: | |
1164 | return graphite_can_represent_init (TREE_OPERAND (e, 0)) | |
1165 | && graphite_can_represent_init (TREE_OPERAND (e, 1)); | |
1166 | ||
1167 | case NEGATE_EXPR: | |
1168 | case BIT_NOT_EXPR: | |
1169 | CASE_CONVERT: | |
1170 | case NON_LVALUE_EXPR: | |
1171 | return graphite_can_represent_init (TREE_OPERAND (e, 0)); | |
1172 | ||
edbec012 | 1173 | default: |
1174 | break; | |
c6bb733d | 1175 | } |
1176 | ||
1177 | return true; | |
1178 | } | |
1179 | ||
1180 | /* Return true when SCEV can be represented in the polyhedral model. | |
1181 | ||
1182 | An expression can be represented, if it can be expressed as an | |
1183 | affine expression. For loops (i, j) and parameters (m, n) all | |
1184 | affine expressions are of the form: | |
1185 | ||
1186 | x1 * i + x2 * j + x3 * m + x4 * n + x5 * 1 where x1..x5 element of Z | |
1187 | ||
1188 | 1 i + 20 j + (-2) m + 25 | |
1189 | ||
e3135850 | 1190 | Something like "i * n" or "n * m" is not allowed. */ |
c6bb733d | 1191 | |
edbec012 | 1192 | bool |
1193 | scop_detection::graphite_can_represent_scev (tree scev) | |
c6bb733d | 1194 | { |
1195 | if (chrec_contains_undetermined (scev)) | |
1196 | return false; | |
1197 | ||
c49ee0f5 | 1198 | /* We disable the handling of pointer types, because it’s currently not |
1199 | supported by Graphite with the ISL AST generator. SSA_NAME nodes are | |
1200 | the only nodes, which are disabled in case they are pointers to object | |
1201 | types, but this can be changed. */ | |
1202 | ||
6cf9f9e0 | 1203 | if (POINTER_TYPE_P (TREE_TYPE (scev)) && TREE_CODE (scev) == SSA_NAME) |
c49ee0f5 | 1204 | return false; |
1205 | ||
99c136a5 | 1206 | switch (TREE_CODE (scev)) |
1207 | { | |
98acb419 | 1208 | case NEGATE_EXPR: |
1209 | case BIT_NOT_EXPR: | |
1210 | CASE_CONVERT: | |
1211 | case NON_LVALUE_EXPR: | |
1212 | return graphite_can_represent_scev (TREE_OPERAND (scev, 0)); | |
1213 | ||
99c136a5 | 1214 | case PLUS_EXPR: |
98acb419 | 1215 | case POINTER_PLUS_EXPR: |
99c136a5 | 1216 | case MINUS_EXPR: |
e3135850 | 1217 | return graphite_can_represent_scev (TREE_OPERAND (scev, 0)) |
1218 | && graphite_can_represent_scev (TREE_OPERAND (scev, 1)); | |
c6bb733d | 1219 | |
99c136a5 | 1220 | case MULT_EXPR: |
1221 | return !CONVERT_EXPR_CODE_P (TREE_CODE (TREE_OPERAND (scev, 0))) | |
1222 | && !CONVERT_EXPR_CODE_P (TREE_CODE (TREE_OPERAND (scev, 1))) | |
1223 | && !(chrec_contains_symbols (TREE_OPERAND (scev, 0)) | |
1224 | && chrec_contains_symbols (TREE_OPERAND (scev, 1))) | |
ce0ae3b6 | 1225 | && graphite_can_represent_init (scev) |
e3135850 | 1226 | && graphite_can_represent_scev (TREE_OPERAND (scev, 0)) |
1227 | && graphite_can_represent_scev (TREE_OPERAND (scev, 1)); | |
c6bb733d | 1228 | |
99c136a5 | 1229 | case POLYNOMIAL_CHREC: |
1230 | /* Check for constant strides. With a non constant stride of | |
1231 | 'n' we would have a value of 'iv * n'. Also check that the | |
1232 | initial value can represented: for example 'n * m' cannot be | |
1233 | represented. */ | |
1234 | if (!evolution_function_right_is_integer_cst (scev) | |
1235 | || !graphite_can_represent_init (scev)) | |
1236 | return false; | |
98acb419 | 1237 | return graphite_can_represent_scev (CHREC_LEFT (scev)); |
99c136a5 | 1238 | |
1239 | default: | |
1240 | break; | |
1241 | } | |
c6bb733d | 1242 | |
1243 | /* Only affine functions can be represented. */ | |
edbec012 | 1244 | if (tree_contains_chrecs (scev, NULL) || !scev_is_linear_expression (scev)) |
c6bb733d | 1245 | return false; |
1246 | ||
629787af | 1247 | return true; |
c6bb733d | 1248 | } |
1249 | ||
c6bb733d | 1250 | /* Return true when EXPR can be represented in the polyhedral model. |
1251 | ||
7eb20e71 | 1252 | This means an expression can be represented, if it is linear with respect to |
1253 | the loops and the strides are non parametric. LOOP is the place where the | |
1254 | expr will be evaluated. SCOP defines the region we analyse. */ | |
c6bb733d | 1255 | |
edbec012 | 1256 | bool |
1257 | scop_detection::graphite_can_represent_expr (sese_l scop, loop_p loop, | |
1258 | tree expr) | |
c6bb733d | 1259 | { |
f032380c | 1260 | tree scev = scalar_evolution_in_region (scop, loop, expr); |
e3135850 | 1261 | return graphite_can_represent_scev (scev); |
c6bb733d | 1262 | } |
1263 | ||
7eb20e71 | 1264 | /* Return true if the data references of STMT can be represented by Graphite. |
1265 | We try to analyze the data references in a loop contained in the SCOP. */ | |
c6bb733d | 1266 | |
edbec012 | 1267 | bool |
1268 | scop_detection::stmt_has_simple_data_refs_p (sese_l scop, gimple *stmt) | |
c6bb733d | 1269 | { |
f032380c | 1270 | loop_p nest = outermost_loop_in_sese (scop, gimple_bb (stmt)); |
443b5bd0 | 1271 | loop_p loop = loop_containing_stmt (stmt); |
1e094109 | 1272 | vec<data_reference_p> drs = vNULL; |
e97c4b0d | 1273 | |
443b5bd0 | 1274 | graphite_find_data_references_in_stmt (nest, loop, stmt, &drs); |
1275 | ||
1276 | int j; | |
1277 | data_reference_p dr; | |
1278 | FOR_EACH_VEC_ELT (drs, j, dr) | |
e97c4b0d | 1279 | { |
443b5bd0 | 1280 | int nb_subscripts = DR_NUM_DIMENSIONS (dr); |
b98a7d5b | 1281 | |
1282 | if (nb_subscripts < 1) | |
1283 | { | |
1284 | free_data_refs (drs); | |
1285 | return false; | |
1286 | } | |
1287 | ||
443b5bd0 | 1288 | tree ref = DR_REF (dr); |
e97c4b0d | 1289 | |
443b5bd0 | 1290 | for (int i = nb_subscripts - 1; i >= 0; i--) |
fc25c670 | 1291 | { |
443b5bd0 | 1292 | if (!graphite_can_represent_scev (DR_ACCESS_FN (dr, i)) |
edbec012 | 1293 | || (TREE_CODE (ref) != ARRAY_REF && TREE_CODE (ref) != MEM_REF |
443b5bd0 | 1294 | && TREE_CODE (ref) != COMPONENT_REF)) |
e97c4b0d | 1295 | { |
443b5bd0 | 1296 | free_data_refs (drs); |
1297 | return false; | |
e97c4b0d | 1298 | } |
1299 | ||
443b5bd0 | 1300 | ref = TREE_OPERAND (ref, 0); |
1301 | } | |
e97c4b0d | 1302 | } |
c6bb733d | 1303 | |
edbec012 | 1304 | free_data_refs (drs); |
1305 | return true; | |
c6bb733d | 1306 | } |
1307 | ||
29663955 | 1308 | /* GIMPLE_ASM and GIMPLE_CALL may embed arbitrary side effects. |
1309 | Calls have side-effects, except those to const or pure | |
1310 | functions. */ | |
c6bb733d | 1311 | |
1312 | static bool | |
29663955 | 1313 | stmt_has_side_effects (gimple *stmt) |
c6bb733d | 1314 | { |
c6bb733d | 1315 | if (gimple_has_volatile_ops (stmt) |
1316 | || (gimple_code (stmt) == GIMPLE_CALL | |
1317 | && !(gimple_call_flags (stmt) & (ECF_CONST | ECF_PURE))) | |
1318 | || (gimple_code (stmt) == GIMPLE_ASM)) | |
4773ab25 | 1319 | { |
7eb20e71 | 1320 | DEBUG_PRINT (dp << "[scop-detection-fail] " |
29663955 | 1321 | << "Statement has side-effects:\n"; |
edbec012 | 1322 | print_gimple_stmt (dump_file, stmt, 0, TDF_VOPS | TDF_MEMSYMS)); |
29663955 | 1323 | return true; |
4773ab25 | 1324 | } |
29663955 | 1325 | return false; |
1326 | } | |
c6bb733d | 1327 | |
29663955 | 1328 | /* Returns true if STMT can be represented in polyhedral model. LABEL, |
1329 | simple COND stmts, pure calls, and assignments can be repesented. */ | |
c6bb733d | 1330 | |
edbec012 | 1331 | bool |
1332 | scop_detection::graphite_can_represent_stmt (sese_l scop, gimple *stmt, | |
1333 | basic_block bb) | |
29663955 | 1334 | { |
1335 | loop_p loop = bb->loop_father; | |
c6bb733d | 1336 | switch (gimple_code (stmt)) |
1337 | { | |
c6bb733d | 1338 | case GIMPLE_LABEL: |
1339 | return true; | |
1340 | ||
1341 | case GIMPLE_COND: | |
1342 | { | |
c6bb733d | 1343 | /* We can handle all binary comparisons. Inequalities are |
1344 | also supported as they can be represented with union of | |
1345 | polyhedra. */ | |
29663955 | 1346 | enum tree_code code = gimple_cond_code (stmt); |
1347 | if (!(code == LT_EXPR | |
c6bb733d | 1348 | || code == GT_EXPR |
1349 | || code == LE_EXPR | |
1350 | || code == GE_EXPR | |
1351 | || code == EQ_EXPR | |
1352 | || code == NE_EXPR)) | |
29663955 | 1353 | { |
1354 | DEBUG_PRINT (dp << "[scop-detection-fail] " | |
7eb20e71 | 1355 | << "Graphite cannot handle cond stmt:\n"; |
edbec012 | 1356 | print_gimple_stmt (dump_file, stmt, 0, |
1357 | TDF_VOPS | TDF_MEMSYMS)); | |
4773ab25 | 1358 | return false; |
1359 | } | |
c6bb733d | 1360 | |
5da4c394 | 1361 | for (unsigned i = 0; i < 2; ++i) |
1362 | { | |
1363 | tree op = gimple_op (stmt, i); | |
7eb20e71 | 1364 | if (!graphite_can_represent_expr (scop, loop, op) |
9852e66f | 1365 | /* We can only constrain on integer type. */ |
1366 | || (TREE_CODE (TREE_TYPE (op)) != INTEGER_TYPE)) | |
4773ab25 | 1367 | { |
edbec012 | 1368 | DEBUG_PRINT (dp << "[scop-detection-fail] " |
1369 | << "Graphite cannot represent stmt:\n"; | |
1370 | print_gimple_stmt (dump_file, stmt, 0, | |
1371 | TDF_VOPS | TDF_MEMSYMS)); | |
4773ab25 | 1372 | return false; |
1373 | } | |
5da4c394 | 1374 | } |
c6bb733d | 1375 | |
1376 | return true; | |
1377 | } | |
1378 | ||
1379 | case GIMPLE_ASSIGN: | |
c6bb733d | 1380 | case GIMPLE_CALL: |
01e31b4b | 1381 | return true; |
c6bb733d | 1382 | |
1383 | default: | |
1384 | /* These nodes cut a new scope. */ | |
edbec012 | 1385 | DEBUG_PRINT ( |
1386 | dp << "[scop-detection-fail] " | |
1387 | << "Gimple stmt not handled in Graphite:\n"; | |
1388 | print_gimple_stmt (dump_file, stmt, 0, TDF_VOPS | TDF_MEMSYMS)); | |
c6bb733d | 1389 | return false; |
1390 | } | |
29663955 | 1391 | } |
c6bb733d | 1392 | |
29663955 | 1393 | /* Return true only when STMT is simple enough for being handled by Graphite. |
1394 | This depends on SCOP, as the parameters are initialized relatively to | |
1395 | this basic block, the linear functions are initialized based on the outermost | |
1396 | loop containing STMT inside the SCOP. BB is the place where we try to | |
1397 | evaluate the STMT. */ | |
1398 | ||
edbec012 | 1399 | bool |
1400 | scop_detection::stmt_simple_for_scop_p (sese_l scop, gimple *stmt, | |
1401 | basic_block bb) const | |
29663955 | 1402 | { |
1403 | gcc_assert (scop); | |
1404 | ||
1405 | if (is_gimple_debug (stmt)) | |
1406 | return true; | |
1407 | ||
1408 | if (stmt_has_side_effects (stmt)) | |
1409 | return false; | |
1410 | ||
1411 | if (!stmt_has_simple_data_refs_p (scop, stmt)) | |
1412 | { | |
1413 | DEBUG_PRINT (dp << "[scop-detection-fail] " | |
1414 | << "Graphite cannot handle data-refs in stmt:\n"; | |
1415 | print_gimple_stmt (dump_file, stmt, 0, TDF_VOPS|TDF_MEMSYMS);); | |
1416 | return false; | |
1417 | } | |
1418 | ||
1419 | return graphite_can_represent_stmt (scop, stmt, bb); | |
c6bb733d | 1420 | } |
1421 | ||
7eb20e71 | 1422 | /* Return true when BB contains a harmful operation for a scop: that |
c6bb733d | 1423 | can be a function call with side effects, the induction variables |
7eb20e71 | 1424 | are not linear with respect to SCOP, etc. The current open |
1425 | scop should end before this statement. */ | |
c6bb733d | 1426 | |
edbec012 | 1427 | bool |
1428 | scop_detection::harmful_stmt_in_bb (sese_l scop, basic_block bb) const | |
c6bb733d | 1429 | { |
1430 | gimple_stmt_iterator gsi; | |
1431 | ||
edbec012 | 1432 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
1433 | if (!stmt_simple_for_scop_p (scop, gsi_stmt (gsi), bb)) | |
1434 | return true; | |
c6bb733d | 1435 | |
edbec012 | 1436 | return false; |
c6bb733d | 1437 | } |
1438 | ||
7eb20e71 | 1439 | /* Return true when the body of LOOP has statements that can be represented as a |
1440 | valid scop. */ | |
1441 | ||
edbec012 | 1442 | bool |
1443 | scop_detection::loop_body_is_valid_scop (loop_p loop, sese_l scop) const | |
7eb20e71 | 1444 | { |
33228567 | 1445 | if (!loop_ivs_can_be_represented (loop)) |
1446 | { | |
edbec012 | 1447 | DEBUG_PRINT (dp << "[scop-detection-fail] loop_" << loop->num |
1448 | << "IV cannot be represented.\n"); | |
33228567 | 1449 | return false; |
1450 | } | |
1451 | ||
7eb20e71 | 1452 | if (!loop_nest_has_data_refs (loop)) |
1453 | { | |
edbec012 | 1454 | DEBUG_PRINT (dp << "[scop-detection-fail] loop_" << loop->num |
1455 | << "does not have any data reference.\n"); | |
7eb20e71 | 1456 | return false; |
1457 | } | |
1458 | ||
1459 | basic_block *bbs = get_loop_body (loop); | |
1460 | for (unsigned i = 0; i < loop->num_nodes; i++) | |
1461 | { | |
1462 | basic_block bb = bbs[i]; | |
1463 | ||
1464 | if (harmful_stmt_in_bb (scop, bb)) | |
1465 | return false; | |
1466 | } | |
1467 | free (bbs); | |
75f966f7 | 1468 | |
1469 | if (loop->inner) | |
1470 | { | |
1471 | loop = loop->inner; | |
1472 | while (loop) | |
1473 | { | |
1474 | if (!loop_body_is_valid_scop (loop, scop)) | |
1475 | return false; | |
1476 | loop = loop->next; | |
1477 | } | |
1478 | } | |
1479 | ||
7eb20e71 | 1480 | return true; |
1481 | } | |
1482 | ||
edbec012 | 1483 | /* Returns the number of pbbs that are in loops contained in SCOP. */ |
7eb20e71 | 1484 | |
edbec012 | 1485 | int |
1486 | scop_detection::nb_pbbs_in_loops (scop_p scop) | |
1487 | { | |
1488 | int i; | |
1489 | poly_bb_p pbb; | |
1490 | int res = 0; | |
7eb20e71 | 1491 | |
0e526381 | 1492 | FOR_EACH_VEC_ELT (scop->pbbs, i, pbb) |
5828c94d | 1493 | if (loop_in_sese_p (gbb_loop (PBB_BLACK_BOX (pbb)), scop->scop_info->region)) |
edbec012 | 1494 | res++; |
7eb20e71 | 1495 | |
edbec012 | 1496 | return res; |
1497 | } | |
7eb20e71 | 1498 | |
118a202b | 1499 | /* When parameter NAME is in REGION, returns its index in SESE_PARAMS. |
1500 | Otherwise returns -1. */ | |
1501 | ||
1502 | static inline int | |
f032380c | 1503 | parameter_index_in_region_1 (tree name, sese_info_p region) |
118a202b | 1504 | { |
1505 | int i; | |
1506 | tree p; | |
1507 | ||
1508 | gcc_assert (TREE_CODE (name) == SSA_NAME); | |
1509 | ||
30162daa | 1510 | FOR_EACH_VEC_ELT (region->params, i, p) |
118a202b | 1511 | if (p == name) |
1512 | return i; | |
1513 | ||
1514 | return -1; | |
1515 | } | |
1516 | ||
1517 | /* When the parameter NAME is in REGION, returns its index in | |
1518 | SESE_PARAMS. Otherwise this function inserts NAME in SESE_PARAMS | |
1519 | and returns the index of NAME. */ | |
1520 | ||
1521 | static int | |
f032380c | 1522 | parameter_index_in_region (tree name, sese_info_p region) |
118a202b | 1523 | { |
1524 | int i; | |
1525 | ||
1526 | gcc_assert (TREE_CODE (name) == SSA_NAME); | |
1527 | ||
1528 | /* Cannot constrain on anything else than INTEGER_TYPE parameters. */ | |
1529 | if (TREE_CODE (TREE_TYPE (name)) != INTEGER_TYPE) | |
1530 | return -1; | |
1531 | ||
13f421d5 | 1532 | if (!invariant_in_sese_p_rec (name, region->region, NULL)) |
118a202b | 1533 | return -1; |
1534 | ||
1535 | i = parameter_index_in_region_1 (name, region); | |
1536 | if (i != -1) | |
1537 | return i; | |
1538 | ||
30162daa | 1539 | i = region->params.length (); |
1540 | region->params.safe_push (name); | |
118a202b | 1541 | return i; |
1542 | } | |
1543 | ||
1544 | /* In the context of sese S, scan the expression E and translate it to | |
1545 | a linear expression C. When parsing a symbolic multiplication, K | |
1546 | represents the constant multiplier of an expression containing | |
1547 | parameters. */ | |
1548 | ||
1549 | static void | |
f032380c | 1550 | scan_tree_for_params (sese_info_p s, tree e) |
118a202b | 1551 | { |
1552 | if (e == chrec_dont_know) | |
1553 | return; | |
1554 | ||
1555 | switch (TREE_CODE (e)) | |
1556 | { | |
1557 | case POLYNOMIAL_CHREC: | |
1558 | scan_tree_for_params (s, CHREC_LEFT (e)); | |
1559 | break; | |
1560 | ||
1561 | case MULT_EXPR: | |
1562 | if (chrec_contains_symbols (TREE_OPERAND (e, 0))) | |
1563 | scan_tree_for_params (s, TREE_OPERAND (e, 0)); | |
1564 | else | |
1565 | scan_tree_for_params (s, TREE_OPERAND (e, 1)); | |
1566 | break; | |
1567 | ||
1568 | case PLUS_EXPR: | |
1569 | case POINTER_PLUS_EXPR: | |
1570 | case MINUS_EXPR: | |
1571 | scan_tree_for_params (s, TREE_OPERAND (e, 0)); | |
1572 | scan_tree_for_params (s, TREE_OPERAND (e, 1)); | |
1573 | break; | |
1574 | ||
1575 | case NEGATE_EXPR: | |
1576 | case BIT_NOT_EXPR: | |
1577 | CASE_CONVERT: | |
1578 | case NON_LVALUE_EXPR: | |
1579 | scan_tree_for_params (s, TREE_OPERAND (e, 0)); | |
1580 | break; | |
1581 | ||
1582 | case SSA_NAME: | |
1583 | parameter_index_in_region (e, s); | |
1584 | break; | |
1585 | ||
1586 | case INTEGER_CST: | |
1587 | case ADDR_EXPR: | |
1588 | case REAL_CST: | |
1589 | case COMPLEX_CST: | |
1590 | case VECTOR_CST: | |
1591 | break; | |
1592 | ||
1593 | default: | |
1594 | gcc_unreachable (); | |
1595 | break; | |
1596 | } | |
1597 | } | |
1598 | ||
1599 | /* Find parameters with respect to REGION in BB. We are looking in memory | |
1600 | access functions, conditions and loop bounds. */ | |
1601 | ||
1602 | static void | |
f032380c | 1603 | find_params_in_bb (sese_info_p region, gimple_poly_bb_p gbb) |
118a202b | 1604 | { |
3b9ce1aa | 1605 | /* Find parameters in the access functions of data references. */ |
118a202b | 1606 | int i; |
118a202b | 1607 | data_reference_p dr; |
118a202b | 1608 | FOR_EACH_VEC_ELT (GBB_DATA_REFS (gbb), i, dr) |
3b9ce1aa | 1609 | for (unsigned j = 0; j < DR_NUM_DIMENSIONS (dr); j++) |
118a202b | 1610 | scan_tree_for_params (region, DR_ACCESS_FN (dr, j)); |
1611 | ||
1612 | /* Find parameters in conditional statements. */ | |
3b9ce1aa | 1613 | gimple *stmt; |
1614 | loop_p loop = GBB_BB (gbb)->loop_father; | |
118a202b | 1615 | FOR_EACH_VEC_ELT (GBB_CONDITIONS (gbb), i, stmt) |
1616 | { | |
f032380c | 1617 | tree lhs = scalar_evolution_in_region (region->region, loop, |
118a202b | 1618 | gimple_cond_lhs (stmt)); |
f032380c | 1619 | tree rhs = scalar_evolution_in_region (region->region, loop, |
118a202b | 1620 | gimple_cond_rhs (stmt)); |
1621 | ||
1622 | scan_tree_for_params (region, lhs); | |
1623 | scan_tree_for_params (region, rhs); | |
1624 | } | |
1625 | } | |
1626 | ||
1627 | /* Record the parameters used in the SCOP. A variable is a parameter | |
1628 | in a scop if it does not vary during the execution of that scop. */ | |
1629 | ||
1630 | static void | |
1631 | find_scop_parameters (scop_p scop) | |
1632 | { | |
118a202b | 1633 | unsigned i; |
5828c94d | 1634 | sese_info_p region = scop->scop_info; |
118a202b | 1635 | struct loop *loop; |
118a202b | 1636 | |
1637 | /* Find the parameters used in the loop bounds. */ | |
30162daa | 1638 | FOR_EACH_VEC_ELT (region->loop_nest, i, loop) |
118a202b | 1639 | { |
1640 | tree nb_iters = number_of_latch_executions (loop); | |
1641 | ||
1642 | if (!chrec_contains_symbols (nb_iters)) | |
1643 | continue; | |
1644 | ||
f032380c | 1645 | nb_iters = scalar_evolution_in_region (region->region, loop, nb_iters); |
118a202b | 1646 | scan_tree_for_params (region, nb_iters); |
1647 | } | |
1648 | ||
1649 | /* Find the parameters used in data accesses. */ | |
3b9ce1aa | 1650 | poly_bb_p pbb; |
0e526381 | 1651 | FOR_EACH_VEC_ELT (scop->pbbs, i, pbb) |
118a202b | 1652 | find_params_in_bb (region, PBB_BLACK_BOX (pbb)); |
1653 | ||
3b9ce1aa | 1654 | int nbp = sese_nb_params (region); |
118a202b | 1655 | scop_set_nb_params (scop, nbp); |
118a202b | 1656 | } |
1657 | ||
30162daa | 1658 | /* Record DEF if it is used in other bbs different than DEF_BB in the SCOP. */ |
1659 | ||
1660 | static void | |
1661 | build_cross_bb_scalars_def (scop_p scop, tree def, basic_block def_bb, | |
1662 | vec<tree> *writes) | |
1663 | { | |
1664 | gcc_assert (def); | |
1665 | if (!is_gimple_reg (def)) | |
1666 | return; | |
1667 | ||
1668 | /* Do not gather scalar variables that can be analyzed by SCEV as they can be | |
1669 | generated out of the induction variables. */ | |
1670 | if (scev_analyzable_p (def, scop->scop_info->region)) | |
1671 | return; | |
1672 | ||
1673 | gimple *use_stmt; | |
1674 | imm_use_iterator imm_iter; | |
1675 | FOR_EACH_IMM_USE_STMT (use_stmt, imm_iter, def) | |
1676 | if (def_bb != gimple_bb (use_stmt) && !is_gimple_debug (use_stmt)) | |
1677 | { | |
1678 | writes->safe_push (def); | |
1679 | DEBUG_PRINT (dp << "Adding scalar write:\n"; | |
1680 | print_generic_expr (dump_file, def, 0); | |
1681 | dp << "From stmt:\n"; | |
1682 | print_gimple_stmt (dump_file, | |
1683 | SSA_NAME_DEF_STMT (def), 0, 0)); | |
1684 | /* This is required by the FOR_EACH_IMM_USE_STMT when we want to break | |
1685 | before all the uses have been visited. */ | |
1686 | BREAK_FROM_IMM_USE_STMT (imm_iter); | |
1687 | } | |
1688 | } | |
1689 | ||
1690 | /* Record DEF if it is used in other bbs different than DEF_BB in the SCOP. */ | |
1691 | ||
1692 | static void | |
1693 | build_cross_bb_scalars_use (scop_p scop, tree use, gimple *use_stmt, | |
1694 | vec<scalar_use> *reads) | |
1695 | { | |
1696 | gcc_assert (use); | |
1697 | if (!is_gimple_reg (use)) | |
1698 | return; | |
1699 | ||
1700 | /* Do not gather scalar variables that can be analyzed by SCEV as they can be | |
1701 | generated out of the induction variables. */ | |
1702 | if (scev_analyzable_p (use, scop->scop_info->region)) | |
1703 | return; | |
1704 | ||
1705 | gimple *def_stmt = SSA_NAME_DEF_STMT (use); | |
1706 | if (gimple_bb (def_stmt) != gimple_bb (use_stmt)) | |
1707 | { | |
1708 | DEBUG_PRINT (dp << "Adding scalar read:\n"; | |
1709 | print_generic_expr (dump_file, use, 0); | |
1710 | dp << "From stmt:\n"; | |
1711 | print_gimple_stmt (dump_file, use_stmt, 0, 0)); | |
1712 | reads->safe_push (std::make_pair (use_stmt, use)); | |
1713 | } | |
1714 | } | |
1715 | ||
1716 | /* Record all scalar variables that are defined and used in different BBs of the | |
1717 | SCOP. */ | |
1718 | ||
1719 | static void | |
1720 | graphite_find_cross_bb_scalar_vars (scop_p scop, gimple *stmt, | |
1721 | vec<scalar_use> *reads, vec<tree> *writes) | |
1722 | { | |
1723 | tree def; | |
1724 | ||
1725 | if (gimple_code (stmt) == GIMPLE_ASSIGN) | |
1726 | def = gimple_assign_lhs (stmt); | |
1727 | else if (gimple_code (stmt) == GIMPLE_CALL) | |
1728 | def = gimple_call_lhs (stmt); | |
1729 | else if (gimple_code (stmt) == GIMPLE_PHI) | |
1730 | def = gimple_phi_result (stmt); | |
1731 | else | |
1732 | return; | |
1733 | ||
1734 | ||
1735 | build_cross_bb_scalars_def (scop, def, gimple_bb (stmt), writes); | |
1736 | ||
1737 | ssa_op_iter iter; | |
1738 | use_operand_p use_p; | |
1739 | FOR_EACH_PHI_OR_STMT_USE (use_p, stmt, iter, SSA_OP_USE) | |
1740 | { | |
1741 | tree use = USE_FROM_PTR (use_p); | |
1742 | build_cross_bb_scalars_use (scop, use, stmt, reads); | |
1743 | } | |
1744 | } | |
1745 | ||
0e526381 | 1746 | /* Generates a polyhedral black box only if the bb contains interesting |
1747 | information. */ | |
1748 | ||
1749 | static gimple_poly_bb_p | |
1750 | try_generate_gimple_bb (scop_p scop, basic_block bb) | |
1751 | { | |
1752 | vec<data_reference_p> drs; | |
30162daa | 1753 | drs.create (3); |
1754 | vec<tree> writes; | |
1755 | writes.create (3); | |
1756 | vec<scalar_use> reads; | |
1757 | reads.create (3); | |
1758 | ||
5828c94d | 1759 | sese_l region = scop->scop_info->region; |
0e526381 | 1760 | loop_p nest = outermost_loop_in_sese (region, bb); |
1761 | ||
1762 | loop_p loop = bb->loop_father; | |
1763 | if (!loop_in_sese_p (loop, region)) | |
1764 | loop = nest; | |
1765 | ||
30162daa | 1766 | for (gimple_stmt_iterator gsi = gsi_start_bb (bb); !gsi_end_p (gsi); |
1767 | gsi_next (&gsi)) | |
0e526381 | 1768 | { |
1769 | gimple *stmt = gsi_stmt (gsi); | |
1770 | if (is_gimple_debug (stmt)) | |
1771 | continue; | |
1772 | ||
1773 | graphite_find_data_references_in_stmt (nest, loop, stmt, &drs); | |
30162daa | 1774 | graphite_find_cross_bb_scalar_vars (scop, stmt, &reads, &writes); |
0e526381 | 1775 | } |
1776 | ||
30162daa | 1777 | for (gphi_iterator psi = gsi_start_phis (bb); !gsi_end_p (psi); |
1778 | gsi_next (&psi)) | |
1779 | if (!virtual_operand_p (gimple_phi_result (psi.phi ()))) | |
1780 | graphite_find_cross_bb_scalar_vars (scop, psi.phi (), &reads, &writes); | |
1781 | ||
1782 | if (drs.is_empty () && writes.is_empty () && reads.is_empty ()) | |
1783 | return NULL; | |
1784 | ||
1785 | return new_gimple_poly_bb (bb, drs, reads, writes); | |
1786 | } | |
1787 | ||
1788 | /* Compute alias-sets for all data references in DRS. */ | |
1789 | ||
1790 | static void | |
1791 | build_alias_set (scop_p scop) | |
1792 | { | |
1793 | int num_vertices = scop->drs.length (); | |
1794 | struct graph *g = new_graph (num_vertices); | |
1795 | dr_info *dr1, *dr2; | |
1796 | int i, j; | |
1797 | int *all_vertices; | |
1798 | ||
1799 | FOR_EACH_VEC_ELT (scop->drs, i, dr1) | |
1800 | for (j = i+1; scop->drs.iterate (j, &dr2); j++) | |
1801 | if (dr_may_alias_p (dr1->dr, dr2->dr, true)) | |
1802 | { | |
1803 | add_edge (g, i, j); | |
1804 | add_edge (g, j, i); | |
1805 | } | |
1806 | ||
1807 | all_vertices = XNEWVEC (int, num_vertices); | |
1808 | for (i = 0; i < num_vertices; i++) | |
1809 | all_vertices[i] = i; | |
1810 | ||
1811 | graphds_dfs (g, all_vertices, num_vertices, NULL, true, NULL); | |
1812 | free (all_vertices); | |
1813 | ||
1814 | for (i = 0; i < g->n_vertices; i++) | |
1815 | scop->drs[i].alias_set = g->vertices[i].component + 1; | |
1816 | ||
1817 | free_graph (g); | |
0e526381 | 1818 | } |
1819 | ||
1820 | /* Gather BBs and conditions for a SCOP. */ | |
1821 | class gather_bbs : public dom_walker | |
edbec012 | 1822 | { |
1823 | public: | |
0e526381 | 1824 | gather_bbs (cdi_direction, scop_p); |
7eb20e71 | 1825 | |
edbec012 | 1826 | virtual void before_dom_children (basic_block); |
1827 | virtual void after_dom_children (basic_block); | |
7eb20e71 | 1828 | |
edbec012 | 1829 | private: |
0e526381 | 1830 | auto_vec<gimple *, 3> conditions, cases; |
1831 | scop_p scop; | |
edbec012 | 1832 | }; |
1833 | } | |
0e526381 | 1834 | gather_bbs::gather_bbs (cdi_direction direction, scop_p scop) |
1835 | : dom_walker (direction), scop (scop) | |
edbec012 | 1836 | { |
1837 | } | |
7eb20e71 | 1838 | |
edbec012 | 1839 | /* Call-back for dom_walk executed before visiting the dominated |
1840 | blocks. */ | |
7eb20e71 | 1841 | |
edbec012 | 1842 | void |
0e526381 | 1843 | gather_bbs::before_dom_children (basic_block bb) |
edbec012 | 1844 | { |
5828c94d | 1845 | if (!bb_in_sese_p (bb, scop->scop_info->region)) |
edbec012 | 1846 | return; |
7eb20e71 | 1847 | |
0e526381 | 1848 | gcond *stmt = single_pred_cond_non_loop_exit (bb); |
7eb20e71 | 1849 | |
edbec012 | 1850 | if (stmt) |
1851 | { | |
1852 | edge e = single_pred_edge (bb); | |
7eb20e71 | 1853 | |
0e526381 | 1854 | conditions.safe_push (stmt); |
7eb20e71 | 1855 | |
edbec012 | 1856 | if (e->flags & EDGE_TRUE_VALUE) |
0e526381 | 1857 | cases.safe_push (stmt); |
edbec012 | 1858 | else |
0e526381 | 1859 | cases.safe_push (NULL); |
edbec012 | 1860 | } |
7eb20e71 | 1861 | |
5828c94d | 1862 | scop->scop_info->bbs.safe_push (bb); |
7eb20e71 | 1863 | |
0e526381 | 1864 | gimple_poly_bb_p gbb = try_generate_gimple_bb (scop, bb); |
30162daa | 1865 | if (!gbb) |
1866 | return; | |
1867 | ||
0e526381 | 1868 | GBB_CONDITIONS (gbb) = conditions.copy (); |
1869 | GBB_CONDITION_CASES (gbb) = cases.copy (); | |
1870 | ||
1871 | poly_bb_p pbb = new_poly_bb (scop, gbb); | |
1872 | scop->pbbs.safe_push (pbb); | |
30162daa | 1873 | |
1874 | int i; | |
1875 | data_reference_p dr; | |
1876 | FOR_EACH_VEC_ELT (gbb->data_refs, i, dr) | |
1877 | scop->drs.safe_push (dr_info (dr, pbb)); | |
edbec012 | 1878 | } |
7eb20e71 | 1879 | |
edbec012 | 1880 | /* Call-back for dom_walk executed after visiting the dominated |
1881 | blocks. */ | |
7eb20e71 | 1882 | |
edbec012 | 1883 | void |
0e526381 | 1884 | gather_bbs::after_dom_children (basic_block bb) |
edbec012 | 1885 | { |
5828c94d | 1886 | if (!bb_in_sese_p (bb, scop->scop_info->region)) |
edbec012 | 1887 | return; |
7eb20e71 | 1888 | |
edbec012 | 1889 | if (single_pred_cond_non_loop_exit (bb)) |
1890 | { | |
0e526381 | 1891 | conditions.pop (); |
1892 | cases.pop (); | |
edbec012 | 1893 | } |
1894 | } | |
7eb20e71 | 1895 | |
1896 | /* Find Static Control Parts (SCoP) in the current function and pushes | |
1897 | them to SCOPS. */ | |
1898 | ||
1899 | void | |
1900 | build_scops (vec<scop_p> *scops) | |
1901 | { | |
1902 | if (dump_file) | |
1903 | dp.set_dump_file (dump_file); | |
1904 | ||
1905 | canonicalize_loop_closed_ssa_form (); | |
1906 | ||
edbec012 | 1907 | scop_detection sb; |
1908 | sb.build_scop_depth (scop_detection::invalid_sese, current_loops->tree_root); | |
16cbd7c3 | 1909 | |
1910 | /* Now create scops from the lightweight SESEs. */ | |
1911 | vec<sese_l> scops_l = sb.get_scops (); | |
1912 | int i; | |
5828c94d | 1913 | sese_l *s; |
16cbd7c3 | 1914 | FOR_EACH_VEC_ELT (scops_l, i, s) |
edbec012 | 1915 | { |
5828c94d | 1916 | scop_p scop = new_scop (s->entry, s->exit); |
edbec012 | 1917 | |
0e526381 | 1918 | /* Record all basic blocks and their conditions in REGION. */ |
1919 | gather_bbs (CDI_DOMINATORS, scop).walk (cfun->cfg->x_entry_block_ptr); | |
1920 | ||
30162daa | 1921 | build_alias_set (scop); |
1922 | ||
edbec012 | 1923 | /* Do not optimize a scop containing only PBBs that do not belong |
1924 | to any loops. */ | |
1925 | if (sb.nb_pbbs_in_loops (scop) == 0) | |
1926 | { | |
118a202b | 1927 | DEBUG_PRINT (dp << "[scop-detection-fail] no data references.\n"); |
1928 | free_scop (scop); | |
1929 | continue; | |
1930 | } | |
1931 | ||
84e96705 | 1932 | unsigned max_arrays = PARAM_VALUE (PARAM_GRAPHITE_MAX_ARRAYS_PER_SCOP); |
1933 | if (scop->drs.length () >= max_arrays) | |
1934 | { | |
1935 | DEBUG_PRINT (dp << "[scop-detection-fail] too many data references: " | |
1936 | << scop->drs.length () | |
1937 | << " is larger than --param graphite-max-arrays-per-scop=" | |
1938 | << max_arrays << ".\n"); | |
1939 | free_scop (scop); | |
1940 | continue; | |
1941 | } | |
1942 | ||
5828c94d | 1943 | build_sese_loop_nests (scop->scop_info); |
118a202b | 1944 | |
1945 | find_scop_parameters (scop); | |
1946 | graphite_dim_t max_dim = PARAM_VALUE (PARAM_GRAPHITE_MAX_NB_SCOP_PARAMS); | |
1947 | ||
1948 | if (scop_nb_params (scop) > max_dim) | |
1949 | { | |
1950 | DEBUG_PRINT (dp << "[scop-detection-fail] too many parameters: " | |
1951 | << scop_nb_params (scop) | |
1952 | << " larger than --param graphite-max-nb-scop-params=" | |
1953 | << max_dim << ".\n"); | |
edbec012 | 1954 | free_scop (scop); |
1955 | continue; | |
1956 | } | |
1957 | ||
1958 | scops->safe_push (scop); | |
1959 | } | |
1960 | ||
7eb20e71 | 1961 | DEBUG_PRINT (dp << "number of SCoPs: " << (scops ? scops->length () : 0);); |
1962 | } | |
1963 | ||
edbec012 | 1964 | #endif /* HAVE_isl */ |