]>
Commit | Line | Data |
---|---|---|
dea61d92 | 1 | /* Loop distribution. |
b03c3082 | 2 | Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 |
c75c517d | 3 | Free Software Foundation, Inc. |
dea61d92 SP |
4 | Contributed by Georges-Andre Silber <Georges-Andre.Silber@ensmp.fr> |
5 | and Sebastian Pop <sebastian.pop@amd.com>. | |
6 | ||
7 | This file is part of GCC. | |
b8698a0f | 8 | |
dea61d92 SP |
9 | GCC is free software; you can redistribute it and/or modify it |
10 | under the terms of the GNU General Public License as published by the | |
11 | Free Software Foundation; either version 3, or (at your option) any | |
12 | later version. | |
b8698a0f | 13 | |
dea61d92 SP |
14 | GCC is distributed in the hope that it will be useful, but WITHOUT |
15 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
16 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
17 | for more details. | |
b8698a0f | 18 | |
dea61d92 SP |
19 | You should have received a copy of the GNU General Public License |
20 | along with GCC; see the file COPYING3. If not see | |
21 | <http://www.gnu.org/licenses/>. */ | |
22 | ||
23 | /* This pass performs loop distribution: for example, the loop | |
24 | ||
25 | |DO I = 2, N | |
26 | | A(I) = B(I) + C | |
27 | | D(I) = A(I-1)*E | |
28 | |ENDDO | |
29 | ||
b8698a0f | 30 | is transformed to |
dea61d92 SP |
31 | |
32 | |DOALL I = 2, N | |
33 | | A(I) = B(I) + C | |
34 | |ENDDO | |
35 | | | |
36 | |DOALL I = 2, N | |
37 | | D(I) = A(I-1)*E | |
38 | |ENDDO | |
39 | ||
40 | This pass uses an RDG, Reduced Dependence Graph built on top of the | |
41 | data dependence relations. The RDG is then topologically sorted to | |
42 | obtain a map of information producers/consumers based on which it | |
43 | generates the new loops. */ | |
44 | ||
45 | #include "config.h" | |
46 | #include "system.h" | |
47 | #include "coretypes.h" | |
dea61d92 | 48 | #include "tree-flow.h" |
dea61d92 | 49 | #include "cfgloop.h" |
dea61d92 SP |
50 | #include "tree-chrec.h" |
51 | #include "tree-data-ref.h" | |
52 | #include "tree-scalar-evolution.h" | |
53 | #include "tree-pass.h" | |
dea61d92 SP |
54 | |
55 | /* If bit I is not set, it means that this node represents an | |
56 | operation that has already been performed, and that should not be | |
57 | performed again. This is the subgraph of remaining important | |
58 | computations that is passed to the DFS algorithm for avoiding to | |
59 | include several times the same stores in different loops. */ | |
60 | static bitmap remaining_stmts; | |
61 | ||
62 | /* A node of the RDG is marked in this bitmap when it has as a | |
63 | predecessor a node that writes to memory. */ | |
64 | static bitmap upstream_mem_writes; | |
65 | ||
66 | /* Update the PHI nodes of NEW_LOOP. NEW_LOOP is a duplicate of | |
67 | ORIG_LOOP. */ | |
68 | ||
69 | static void | |
70 | update_phis_for_loop_copy (struct loop *orig_loop, struct loop *new_loop) | |
71 | { | |
72 | tree new_ssa_name; | |
726a989a | 73 | gimple_stmt_iterator si_new, si_orig; |
dea61d92 SP |
74 | edge orig_loop_latch = loop_latch_edge (orig_loop); |
75 | edge orig_entry_e = loop_preheader_edge (orig_loop); | |
76 | edge new_loop_entry_e = loop_preheader_edge (new_loop); | |
77 | ||
78 | /* Scan the phis in the headers of the old and new loops | |
79 | (they are organized in exactly the same order). */ | |
726a989a RB |
80 | for (si_new = gsi_start_phis (new_loop->header), |
81 | si_orig = gsi_start_phis (orig_loop->header); | |
82 | !gsi_end_p (si_new) && !gsi_end_p (si_orig); | |
83 | gsi_next (&si_new), gsi_next (&si_orig)) | |
dea61d92 | 84 | { |
726a989a | 85 | tree def; |
f5045c96 | 86 | source_location locus; |
726a989a RB |
87 | gimple phi_new = gsi_stmt (si_new); |
88 | gimple phi_orig = gsi_stmt (si_orig); | |
89 | ||
dea61d92 SP |
90 | /* Add the first phi argument for the phi in NEW_LOOP (the one |
91 | associated with the entry of NEW_LOOP) */ | |
726a989a | 92 | def = PHI_ARG_DEF_FROM_EDGE (phi_orig, orig_entry_e); |
f5045c96 AM |
93 | locus = gimple_phi_arg_location_from_edge (phi_orig, orig_entry_e); |
94 | add_phi_arg (phi_new, def, new_loop_entry_e, locus); | |
dea61d92 SP |
95 | |
96 | /* Add the second phi argument for the phi in NEW_LOOP (the one | |
97 | associated with the latch of NEW_LOOP) */ | |
98 | def = PHI_ARG_DEF_FROM_EDGE (phi_orig, orig_loop_latch); | |
f5045c96 | 99 | locus = gimple_phi_arg_location_from_edge (phi_orig, orig_loop_latch); |
dea61d92 SP |
100 | |
101 | if (TREE_CODE (def) == SSA_NAME) | |
102 | { | |
103 | new_ssa_name = get_current_def (def); | |
104 | ||
105 | if (!new_ssa_name) | |
106 | /* This only happens if there are no definitions inside the | |
61226dc8 SP |
107 | loop. Use the the invariant in the new loop as is. */ |
108 | new_ssa_name = def; | |
dea61d92 SP |
109 | } |
110 | else | |
111 | /* Could be an integer. */ | |
112 | new_ssa_name = def; | |
113 | ||
f5045c96 | 114 | add_phi_arg (phi_new, new_ssa_name, loop_latch_edge (new_loop), locus); |
dea61d92 SP |
115 | } |
116 | } | |
117 | ||
118 | /* Return a copy of LOOP placed before LOOP. */ | |
119 | ||
120 | static struct loop * | |
121 | copy_loop_before (struct loop *loop) | |
122 | { | |
123 | struct loop *res; | |
124 | edge preheader = loop_preheader_edge (loop); | |
125 | ||
126 | if (!single_exit (loop)) | |
127 | return NULL; | |
128 | ||
129 | initialize_original_copy_tables (); | |
130 | res = slpeel_tree_duplicate_loop_to_edge_cfg (loop, preheader); | |
131 | free_original_copy_tables (); | |
132 | ||
133 | if (!res) | |
134 | return NULL; | |
135 | ||
136 | update_phis_for_loop_copy (loop, res); | |
137 | rename_variables_in_loop (res); | |
138 | ||
139 | return res; | |
140 | } | |
141 | ||
142 | /* Creates an empty basic block after LOOP. */ | |
143 | ||
144 | static void | |
145 | create_bb_after_loop (struct loop *loop) | |
146 | { | |
147 | edge exit = single_exit (loop); | |
148 | ||
149 | if (!exit) | |
150 | return; | |
151 | ||
152 | split_edge (exit); | |
153 | } | |
154 | ||
155 | /* Generate code for PARTITION from the code in LOOP. The loop is | |
156 | copied when COPY_P is true. All the statements not flagged in the | |
157 | PARTITION bitmap are removed from the loop or from its copy. The | |
158 | statements are indexed in sequence inside a basic block, and the | |
159 | basic blocks of a loop are taken in dom order. Returns true when | |
160 | the code gen succeeded. */ | |
161 | ||
162 | static bool | |
163 | generate_loops_for_partition (struct loop *loop, bitmap partition, bool copy_p) | |
164 | { | |
165 | unsigned i, x; | |
726a989a | 166 | gimple_stmt_iterator bsi; |
dea61d92 SP |
167 | basic_block *bbs; |
168 | ||
169 | if (copy_p) | |
170 | { | |
171 | loop = copy_loop_before (loop); | |
172 | create_preheader (loop, CP_SIMPLE_PREHEADERS); | |
173 | create_bb_after_loop (loop); | |
174 | } | |
175 | ||
176 | if (loop == NULL) | |
177 | return false; | |
178 | ||
179 | /* Remove stmts not in the PARTITION bitmap. The order in which we | |
180 | visit the phi nodes and the statements is exactly as in | |
181 | stmts_from_loop. */ | |
182 | bbs = get_loop_body_in_dom_order (loop); | |
183 | ||
b03c3082 JJ |
184 | if (MAY_HAVE_DEBUG_STMTS) |
185 | for (x = 0, i = 0; i < loop->num_nodes; i++) | |
186 | { | |
187 | basic_block bb = bbs[i]; | |
188 | ||
189 | for (bsi = gsi_start_phis (bb); !gsi_end_p (bsi); gsi_next (&bsi)) | |
190 | if (!bitmap_bit_p (partition, x++)) | |
191 | reset_debug_uses (gsi_stmt (bsi)); | |
192 | ||
193 | for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) | |
194 | { | |
195 | gimple stmt = gsi_stmt (bsi); | |
196 | if (gimple_code (stmt) != GIMPLE_LABEL | |
197 | && !is_gimple_debug (stmt) | |
198 | && !bitmap_bit_p (partition, x++)) | |
199 | reset_debug_uses (stmt); | |
200 | } | |
201 | } | |
202 | ||
dea61d92 SP |
203 | for (x = 0, i = 0; i < loop->num_nodes; i++) |
204 | { | |
205 | basic_block bb = bbs[i]; | |
dea61d92 | 206 | |
726a989a | 207 | for (bsi = gsi_start_phis (bb); !gsi_end_p (bsi);) |
dea61d92 | 208 | if (!bitmap_bit_p (partition, x++)) |
2706a615 RG |
209 | { |
210 | gimple phi = gsi_stmt (bsi); | |
211 | if (!is_gimple_reg (gimple_phi_result (phi))) | |
212 | mark_virtual_phi_result_for_renaming (phi); | |
213 | remove_phi_node (&bsi, true); | |
214 | } | |
dea61d92 | 215 | else |
726a989a | 216 | gsi_next (&bsi); |
dea61d92 | 217 | |
726a989a | 218 | for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi);) |
2706a615 RG |
219 | { |
220 | gimple stmt = gsi_stmt (bsi); | |
b03c3082 JJ |
221 | if (gimple_code (stmt) != GIMPLE_LABEL |
222 | && !is_gimple_debug (stmt) | |
2706a615 RG |
223 | && !bitmap_bit_p (partition, x++)) |
224 | { | |
225 | unlink_stmt_vdef (stmt); | |
226 | gsi_remove (&bsi, true); | |
227 | release_defs (stmt); | |
228 | } | |
229 | else | |
230 | gsi_next (&bsi); | |
231 | } | |
dea61d92 SP |
232 | } |
233 | ||
234 | free (bbs); | |
235 | return true; | |
236 | } | |
237 | ||
ada39f0b | 238 | /* Build the size argument for a memset call. */ |
3661e899 TB |
239 | |
240 | static inline tree | |
fc81a369 RH |
241 | build_size_arg_loc (location_t loc, tree nb_iter, tree op, |
242 | gimple_seq *stmt_list) | |
3661e899 | 243 | { |
fc81a369 | 244 | gimple_seq stmts; |
3b9e5d95 EB |
245 | tree x = size_binop_loc (loc, MULT_EXPR, |
246 | fold_convert_loc (loc, sizetype, nb_iter), | |
247 | TYPE_SIZE_UNIT (TREE_TYPE (op))); | |
fc81a369 RH |
248 | x = force_gimple_operand (x, &stmts, true, NULL); |
249 | gimple_seq_add_seq (stmt_list, stmts); | |
3661e899 | 250 | |
fc81a369 | 251 | return x; |
3661e899 TB |
252 | } |
253 | ||
dea61d92 SP |
254 | /* Generate a call to memset. Return true when the operation succeeded. */ |
255 | ||
cfee318d | 256 | static void |
726a989a RB |
257 | generate_memset_zero (gimple stmt, tree op0, tree nb_iter, |
258 | gimple_stmt_iterator bsi) | |
dea61d92 | 259 | { |
fc81a369 | 260 | tree addr_base, nb_bytes; |
dea61d92 | 261 | bool res = false; |
fc81a369 | 262 | gimple_seq stmt_list = NULL, stmts; |
726a989a | 263 | gimple fn_call; |
fc81a369 | 264 | tree mem, fn; |
dea61d92 | 265 | struct data_reference *dr = XCNEW (struct data_reference); |
db3927fb | 266 | location_t loc = gimple_location (stmt); |
dea61d92 | 267 | |
dea61d92 SP |
268 | DR_STMT (dr) = stmt; |
269 | DR_REF (dr) = op0; | |
cfee318d SP |
270 | res = dr_analyze_innermost (dr); |
271 | gcc_assert (res && stride_of_unit_type_p (DR_STEP (dr), TREE_TYPE (op0))); | |
5e37ea0e SP |
272 | |
273 | nb_bytes = build_size_arg_loc (loc, nb_iter, op0, &stmt_list); | |
274 | addr_base = size_binop_loc (loc, PLUS_EXPR, DR_OFFSET (dr), DR_INIT (dr)); | |
275 | addr_base = fold_convert_loc (loc, sizetype, addr_base); | |
dea61d92 SP |
276 | |
277 | /* Test for a negative stride, iterating over every element. */ | |
5e37ea0e SP |
278 | if (integer_zerop (size_binop (PLUS_EXPR, |
279 | TYPE_SIZE_UNIT (TREE_TYPE (op0)), | |
280 | fold_convert (sizetype, DR_STEP (dr))))) | |
dea61d92 | 281 | { |
fc81a369 RH |
282 | addr_base = size_binop_loc (loc, MINUS_EXPR, addr_base, |
283 | fold_convert_loc (loc, sizetype, nb_bytes)); | |
6edd8198 AM |
284 | addr_base = size_binop_loc (loc, PLUS_EXPR, addr_base, |
285 | TYPE_SIZE_UNIT (TREE_TYPE (op0))); | |
dea61d92 | 286 | } |
dea61d92 | 287 | |
5e37ea0e SP |
288 | addr_base = fold_build2_loc (loc, POINTER_PLUS_EXPR, |
289 | TREE_TYPE (DR_BASE_ADDRESS (dr)), | |
290 | DR_BASE_ADDRESS (dr), addr_base); | |
dea61d92 | 291 | mem = force_gimple_operand (addr_base, &stmts, true, NULL); |
726a989a | 292 | gimple_seq_add_seq (&stmt_list, stmts); |
dea61d92 | 293 | |
fc81a369 | 294 | fn = build_fold_addr_expr (implicit_built_in_decls [BUILT_IN_MEMSET]); |
726a989a RB |
295 | fn_call = gimple_build_call (fn, 3, mem, integer_zero_node, nb_bytes); |
296 | gimple_seq_add_stmt (&stmt_list, fn_call); | |
726a989a | 297 | gsi_insert_seq_after (&bsi, stmt_list, GSI_CONTINUE_LINKING); |
dea61d92 SP |
298 | |
299 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
300 | fprintf (dump_file, "generated memset zero\n"); | |
301 | ||
dea61d92 | 302 | free_data_ref (dr); |
dea61d92 SP |
303 | } |
304 | ||
305 | /* Tries to generate a builtin function for the instructions of LOOP | |
306 | pointed to by the bits set in PARTITION. Returns true when the | |
307 | operation succeeded. */ | |
308 | ||
309 | static bool | |
310 | generate_builtin (struct loop *loop, bitmap partition, bool copy_p) | |
311 | { | |
312 | bool res = false; | |
313 | unsigned i, x = 0; | |
314 | basic_block *bbs; | |
726a989a | 315 | gimple write = NULL; |
726a989a | 316 | gimple_stmt_iterator bsi; |
dea61d92 SP |
317 | tree nb_iter = number_of_exit_cond_executions (loop); |
318 | ||
319 | if (!nb_iter || nb_iter == chrec_dont_know) | |
320 | return false; | |
321 | ||
322 | bbs = get_loop_body_in_dom_order (loop); | |
323 | ||
324 | for (i = 0; i < loop->num_nodes; i++) | |
325 | { | |
326 | basic_block bb = bbs[i]; | |
dea61d92 | 327 | |
726a989a | 328 | for (bsi = gsi_start_phis (bb); !gsi_end_p (bsi); gsi_next (&bsi)) |
dea61d92 SP |
329 | x++; |
330 | ||
726a989a | 331 | for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) |
dea61d92 | 332 | { |
726a989a | 333 | gimple stmt = gsi_stmt (bsi); |
dea61d92 | 334 | |
b03c3082 JJ |
335 | if (gimple_code (stmt) != GIMPLE_LABEL |
336 | && !is_gimple_debug (stmt) | |
337 | && bitmap_bit_p (partition, x++) | |
726a989a RB |
338 | && is_gimple_assign (stmt) |
339 | && !is_gimple_reg (gimple_assign_lhs (stmt))) | |
dea61d92 SP |
340 | { |
341 | /* Don't generate the builtins when there are more than | |
342 | one memory write. */ | |
343 | if (write != NULL) | |
344 | goto end; | |
345 | ||
346 | write = stmt; | |
6edd8198 AM |
347 | if (bb == loop->latch) |
348 | nb_iter = number_of_latch_executions (loop); | |
dea61d92 SP |
349 | } |
350 | } | |
351 | } | |
352 | ||
cfee318d | 353 | if (!stmt_with_adjacent_zero_store_dr_p (write)) |
dea61d92 SP |
354 | goto end; |
355 | ||
356 | /* The new statements will be placed before LOOP. */ | |
726a989a | 357 | bsi = gsi_last_bb (loop_preheader_edge (loop)->src); |
cfee318d SP |
358 | generate_memset_zero (write, gimple_assign_lhs (write), nb_iter, bsi); |
359 | res = true; | |
dea61d92 SP |
360 | |
361 | /* If this is the last partition for which we generate code, we have | |
362 | to destroy the loop. */ | |
cfee318d | 363 | if (!copy_p) |
dea61d92 SP |
364 | { |
365 | unsigned nbbs = loop->num_nodes; | |
5923c6c3 RG |
366 | edge exit = single_exit (loop); |
367 | basic_block src = loop_preheader_edge (loop)->src, dest = exit->dest; | |
368 | redirect_edge_pred (exit, src); | |
369 | exit->flags &= ~(EDGE_TRUE_VALUE|EDGE_FALSE_VALUE); | |
370 | exit->flags |= EDGE_FALLTHRU; | |
dea61d92 | 371 | cancel_loop_tree (loop); |
5923c6c3 | 372 | rescan_loop_exit (exit, false, true); |
dea61d92 SP |
373 | |
374 | for (i = 0; i < nbbs; i++) | |
375 | delete_basic_block (bbs[i]); | |
d5e54bc1 KH |
376 | |
377 | set_immediate_dominator (CDI_DOMINATORS, dest, | |
378 | recompute_dominator (CDI_DOMINATORS, dest)); | |
dea61d92 SP |
379 | } |
380 | ||
381 | end: | |
382 | free (bbs); | |
383 | return res; | |
384 | } | |
385 | ||
386 | /* Generates code for PARTITION. For simple loops, this function can | |
387 | generate a built-in. */ | |
388 | ||
389 | static bool | |
390 | generate_code_for_partition (struct loop *loop, bitmap partition, bool copy_p) | |
391 | { | |
392 | if (generate_builtin (loop, partition, copy_p)) | |
393 | return true; | |
394 | ||
395 | return generate_loops_for_partition (loop, partition, copy_p); | |
396 | } | |
397 | ||
398 | ||
399 | /* Returns true if the node V of RDG cannot be recomputed. */ | |
400 | ||
401 | static bool | |
402 | rdg_cannot_recompute_vertex_p (struct graph *rdg, int v) | |
403 | { | |
404 | if (RDG_MEM_WRITE_STMT (rdg, v)) | |
405 | return true; | |
406 | ||
407 | return false; | |
408 | } | |
409 | ||
410 | /* Returns true when the vertex V has already been generated in the | |
411 | current partition (V is in PROCESSED), or when V belongs to another | |
412 | partition and cannot be recomputed (V is not in REMAINING_STMTS). */ | |
413 | ||
414 | static inline bool | |
415 | already_processed_vertex_p (bitmap processed, int v) | |
416 | { | |
417 | return (bitmap_bit_p (processed, v) | |
418 | || !bitmap_bit_p (remaining_stmts, v)); | |
419 | } | |
420 | ||
421 | /* Returns NULL when there is no anti-dependence among the successors | |
422 | of vertex V, otherwise returns the edge with the anti-dep. */ | |
423 | ||
424 | static struct graph_edge * | |
425 | has_anti_dependence (struct vertex *v) | |
426 | { | |
427 | struct graph_edge *e; | |
428 | ||
429 | if (v->succ) | |
430 | for (e = v->succ; e; e = e->succ_next) | |
431 | if (RDGE_TYPE (e) == anti_dd) | |
432 | return e; | |
433 | ||
434 | return NULL; | |
435 | } | |
436 | ||
437 | /* Returns true when V has an anti-dependence edge among its successors. */ | |
438 | ||
439 | static bool | |
440 | predecessor_has_mem_write (struct graph *rdg, struct vertex *v) | |
441 | { | |
442 | struct graph_edge *e; | |
443 | ||
444 | if (v->pred) | |
445 | for (e = v->pred; e; e = e->pred_next) | |
446 | if (bitmap_bit_p (upstream_mem_writes, e->src) | |
447 | /* Don't consider flow channels: a write to memory followed | |
448 | by a read from memory. These channels allow the split of | |
449 | the RDG in different partitions. */ | |
450 | && !RDG_MEM_WRITE_STMT (rdg, e->src)) | |
451 | return true; | |
452 | ||
453 | return false; | |
454 | } | |
455 | ||
456 | /* Initializes the upstream_mem_writes bitmap following the | |
457 | information from RDG. */ | |
458 | ||
459 | static void | |
460 | mark_nodes_having_upstream_mem_writes (struct graph *rdg) | |
461 | { | |
462 | int v, x; | |
463 | bitmap seen = BITMAP_ALLOC (NULL); | |
464 | ||
465 | for (v = rdg->n_vertices - 1; v >= 0; v--) | |
466 | if (!bitmap_bit_p (seen, v)) | |
467 | { | |
468 | unsigned i; | |
469 | VEC (int, heap) *nodes = VEC_alloc (int, heap, 3); | |
dea61d92 SP |
470 | |
471 | graphds_dfs (rdg, &v, 1, &nodes, false, NULL); | |
472 | ||
ac47786e | 473 | FOR_EACH_VEC_ELT (int, nodes, i, x) |
dea61d92 | 474 | { |
fcaa4ca4 | 475 | if (!bitmap_set_bit (seen, x)) |
dea61d92 SP |
476 | continue; |
477 | ||
dea61d92 SP |
478 | if (RDG_MEM_WRITE_STMT (rdg, x) |
479 | || predecessor_has_mem_write (rdg, &(rdg->vertices[x])) | |
480 | /* In anti dependences the read should occur before | |
481 | the write, this is why both the read and the write | |
482 | should be placed in the same partition. */ | |
483 | || has_anti_dependence (&(rdg->vertices[x]))) | |
484 | { | |
dea61d92 SP |
485 | bitmap_set_bit (upstream_mem_writes, x); |
486 | } | |
487 | } | |
488 | ||
489 | VEC_free (int, heap, nodes); | |
490 | } | |
491 | } | |
492 | ||
493 | /* Returns true when vertex u has a memory write node as a predecessor | |
494 | in RDG. */ | |
495 | ||
496 | static bool | |
497 | has_upstream_mem_writes (int u) | |
498 | { | |
499 | return bitmap_bit_p (upstream_mem_writes, u); | |
500 | } | |
501 | ||
502 | static void rdg_flag_vertex_and_dependent (struct graph *, int, bitmap, bitmap, | |
503 | bitmap, bool *); | |
504 | ||
dea61d92 SP |
505 | /* Flag the uses of U stopping following the information from |
506 | upstream_mem_writes. */ | |
507 | ||
508 | static void | |
509 | rdg_flag_uses (struct graph *rdg, int u, bitmap partition, bitmap loops, | |
510 | bitmap processed, bool *part_has_writes) | |
511 | { | |
dea61d92 SP |
512 | use_operand_p use_p; |
513 | struct vertex *x = &(rdg->vertices[u]); | |
726a989a | 514 | gimple stmt = RDGV_STMT (x); |
dea61d92 SP |
515 | struct graph_edge *anti_dep = has_anti_dependence (x); |
516 | ||
517 | /* Keep in the same partition the destination of an antidependence, | |
518 | because this is a store to the exact same location. Putting this | |
519 | in another partition is bad for cache locality. */ | |
520 | if (anti_dep) | |
521 | { | |
522 | int v = anti_dep->dest; | |
523 | ||
524 | if (!already_processed_vertex_p (processed, v)) | |
525 | rdg_flag_vertex_and_dependent (rdg, v, partition, loops, | |
526 | processed, part_has_writes); | |
527 | } | |
528 | ||
726a989a | 529 | if (gimple_code (stmt) != GIMPLE_PHI) |
dea61d92 | 530 | { |
5006671f | 531 | if ((use_p = gimple_vuse_op (stmt)) != NULL_USE_OPERAND_P) |
dea61d92 SP |
532 | { |
533 | tree use = USE_FROM_PTR (use_p); | |
534 | ||
535 | if (TREE_CODE (use) == SSA_NAME) | |
536 | { | |
726a989a | 537 | gimple def_stmt = SSA_NAME_DEF_STMT (use); |
dea61d92 SP |
538 | int v = rdg_vertex_for_stmt (rdg, def_stmt); |
539 | ||
540 | if (v >= 0 | |
541 | && !already_processed_vertex_p (processed, v)) | |
542 | rdg_flag_vertex_and_dependent (rdg, v, partition, loops, | |
543 | processed, part_has_writes); | |
544 | } | |
545 | } | |
546 | } | |
547 | ||
726a989a | 548 | if (is_gimple_assign (stmt) && has_upstream_mem_writes (u)) |
dea61d92 | 549 | { |
726a989a | 550 | tree op0 = gimple_assign_lhs (stmt); |
dea61d92 SP |
551 | |
552 | /* Scalar channels don't have enough space for transmitting data | |
553 | between tasks, unless we add more storage by privatizing. */ | |
554 | if (is_gimple_reg (op0)) | |
555 | { | |
556 | use_operand_p use_p; | |
557 | imm_use_iterator iter; | |
558 | ||
559 | FOR_EACH_IMM_USE_FAST (use_p, iter, op0) | |
560 | { | |
561 | int v = rdg_vertex_for_stmt (rdg, USE_STMT (use_p)); | |
562 | ||
563 | if (!already_processed_vertex_p (processed, v)) | |
564 | rdg_flag_vertex_and_dependent (rdg, v, partition, loops, | |
565 | processed, part_has_writes); | |
566 | } | |
567 | } | |
568 | } | |
569 | } | |
570 | ||
571 | /* Flag V from RDG as part of PARTITION, and also flag its loop number | |
572 | in LOOPS. */ | |
573 | ||
574 | static void | |
575 | rdg_flag_vertex (struct graph *rdg, int v, bitmap partition, bitmap loops, | |
576 | bool *part_has_writes) | |
577 | { | |
578 | struct loop *loop; | |
579 | ||
fcaa4ca4 | 580 | if (!bitmap_set_bit (partition, v)) |
dea61d92 SP |
581 | return; |
582 | ||
583 | loop = loop_containing_stmt (RDG_STMT (rdg, v)); | |
584 | bitmap_set_bit (loops, loop->num); | |
dea61d92 SP |
585 | |
586 | if (rdg_cannot_recompute_vertex_p (rdg, v)) | |
587 | { | |
588 | *part_has_writes = true; | |
589 | bitmap_clear_bit (remaining_stmts, v); | |
590 | } | |
591 | } | |
592 | ||
593 | /* Flag in the bitmap PARTITION the vertex V and all its predecessors. | |
fa10beec | 594 | Also flag their loop number in LOOPS. */ |
dea61d92 SP |
595 | |
596 | static void | |
597 | rdg_flag_vertex_and_dependent (struct graph *rdg, int v, bitmap partition, | |
598 | bitmap loops, bitmap processed, | |
599 | bool *part_has_writes) | |
600 | { | |
601 | unsigned i; | |
602 | VEC (int, heap) *nodes = VEC_alloc (int, heap, 3); | |
603 | int x; | |
604 | ||
605 | bitmap_set_bit (processed, v); | |
606 | rdg_flag_uses (rdg, v, partition, loops, processed, part_has_writes); | |
607 | graphds_dfs (rdg, &v, 1, &nodes, false, remaining_stmts); | |
608 | rdg_flag_vertex (rdg, v, partition, loops, part_has_writes); | |
609 | ||
ac47786e | 610 | FOR_EACH_VEC_ELT (int, nodes, i, x) |
dea61d92 SP |
611 | if (!already_processed_vertex_p (processed, x)) |
612 | rdg_flag_vertex_and_dependent (rdg, x, partition, loops, processed, | |
613 | part_has_writes); | |
614 | ||
615 | VEC_free (int, heap, nodes); | |
616 | } | |
617 | ||
618 | /* Initialize CONDS with all the condition statements from the basic | |
619 | blocks of LOOP. */ | |
620 | ||
621 | static void | |
726a989a | 622 | collect_condition_stmts (struct loop *loop, VEC (gimple, heap) **conds) |
dea61d92 SP |
623 | { |
624 | unsigned i; | |
625 | edge e; | |
626 | VEC (edge, heap) *exits = get_loop_exit_edges (loop); | |
627 | ||
ac47786e | 628 | FOR_EACH_VEC_ELT (edge, exits, i, e) |
dea61d92 | 629 | { |
726a989a | 630 | gimple cond = last_stmt (e->src); |
dea61d92 SP |
631 | |
632 | if (cond) | |
726a989a | 633 | VEC_safe_push (gimple, heap, *conds, cond); |
dea61d92 SP |
634 | } |
635 | ||
636 | VEC_free (edge, heap, exits); | |
637 | } | |
638 | ||
639 | /* Add to PARTITION all the exit condition statements for LOOPS | |
640 | together with all their dependent statements determined from | |
641 | RDG. */ | |
642 | ||
643 | static void | |
644 | rdg_flag_loop_exits (struct graph *rdg, bitmap loops, bitmap partition, | |
645 | bitmap processed, bool *part_has_writes) | |
646 | { | |
647 | unsigned i; | |
648 | bitmap_iterator bi; | |
726a989a | 649 | VEC (gimple, heap) *conds = VEC_alloc (gimple, heap, 3); |
dea61d92 SP |
650 | |
651 | EXECUTE_IF_SET_IN_BITMAP (loops, 0, i, bi) | |
652 | collect_condition_stmts (get_loop (i), &conds); | |
653 | ||
726a989a | 654 | while (!VEC_empty (gimple, conds)) |
dea61d92 | 655 | { |
726a989a | 656 | gimple cond = VEC_pop (gimple, conds); |
dea61d92 SP |
657 | int v = rdg_vertex_for_stmt (rdg, cond); |
658 | bitmap new_loops = BITMAP_ALLOC (NULL); | |
659 | ||
660 | if (!already_processed_vertex_p (processed, v)) | |
661 | rdg_flag_vertex_and_dependent (rdg, v, partition, new_loops, processed, | |
662 | part_has_writes); | |
663 | ||
664 | EXECUTE_IF_SET_IN_BITMAP (new_loops, 0, i, bi) | |
fcaa4ca4 NF |
665 | if (bitmap_set_bit (loops, i)) |
666 | collect_condition_stmts (get_loop (i), &conds); | |
dea61d92 SP |
667 | |
668 | BITMAP_FREE (new_loops); | |
669 | } | |
01be8516 SP |
670 | |
671 | VEC_free (gimple, heap, conds); | |
dea61d92 SP |
672 | } |
673 | ||
dea61d92 SP |
674 | /* Returns a bitmap in which all the statements needed for computing |
675 | the strongly connected component C of the RDG are flagged, also | |
676 | including the loop exit conditions. */ | |
677 | ||
678 | static bitmap | |
679 | build_rdg_partition_for_component (struct graph *rdg, rdgc c, | |
cfee318d | 680 | bool *part_has_writes) |
dea61d92 SP |
681 | { |
682 | int i, v; | |
683 | bitmap partition = BITMAP_ALLOC (NULL); | |
684 | bitmap loops = BITMAP_ALLOC (NULL); | |
685 | bitmap processed = BITMAP_ALLOC (NULL); | |
686 | ||
ac47786e | 687 | FOR_EACH_VEC_ELT (int, c->vertices, i, v) |
dea61d92 SP |
688 | if (!already_processed_vertex_p (processed, v)) |
689 | rdg_flag_vertex_and_dependent (rdg, v, partition, loops, processed, | |
690 | part_has_writes); | |
691 | ||
dea61d92 SP |
692 | rdg_flag_loop_exits (rdg, loops, partition, processed, part_has_writes); |
693 | ||
694 | BITMAP_FREE (processed); | |
695 | BITMAP_FREE (loops); | |
696 | return partition; | |
697 | } | |
698 | ||
699 | /* Free memory for COMPONENTS. */ | |
700 | ||
701 | static void | |
702 | free_rdg_components (VEC (rdgc, heap) *components) | |
703 | { | |
704 | int i; | |
705 | rdgc x; | |
706 | ||
ac47786e | 707 | FOR_EACH_VEC_ELT (rdgc, components, i, x) |
dea61d92 SP |
708 | { |
709 | VEC_free (int, heap, x->vertices); | |
710 | free (x); | |
711 | } | |
01be8516 SP |
712 | |
713 | VEC_free (rdgc, heap, components); | |
dea61d92 SP |
714 | } |
715 | ||
716 | /* Build the COMPONENTS vector with the strongly connected components | |
717 | of RDG in which the STARTING_VERTICES occur. */ | |
718 | ||
719 | static void | |
b8698a0f | 720 | rdg_build_components (struct graph *rdg, VEC (int, heap) *starting_vertices, |
dea61d92 SP |
721 | VEC (rdgc, heap) **components) |
722 | { | |
723 | int i, v; | |
724 | bitmap saved_components = BITMAP_ALLOC (NULL); | |
725 | int n_components = graphds_scc (rdg, NULL); | |
726 | VEC (int, heap) **all_components = XNEWVEC (VEC (int, heap) *, n_components); | |
727 | ||
728 | for (i = 0; i < n_components; i++) | |
729 | all_components[i] = VEC_alloc (int, heap, 3); | |
730 | ||
731 | for (i = 0; i < rdg->n_vertices; i++) | |
732 | VEC_safe_push (int, heap, all_components[rdg->vertices[i].component], i); | |
733 | ||
ac47786e | 734 | FOR_EACH_VEC_ELT (int, starting_vertices, i, v) |
dea61d92 SP |
735 | { |
736 | int c = rdg->vertices[v].component; | |
737 | ||
fcaa4ca4 | 738 | if (bitmap_set_bit (saved_components, c)) |
dea61d92 SP |
739 | { |
740 | rdgc x = XCNEW (struct rdg_component); | |
741 | x->num = c; | |
742 | x->vertices = all_components[c]; | |
743 | ||
744 | VEC_safe_push (rdgc, heap, *components, x); | |
dea61d92 SP |
745 | } |
746 | } | |
747 | ||
748 | for (i = 0; i < n_components; i++) | |
749 | if (!bitmap_bit_p (saved_components, i)) | |
750 | VEC_free (int, heap, all_components[i]); | |
751 | ||
752 | free (all_components); | |
753 | BITMAP_FREE (saved_components); | |
754 | } | |
755 | ||
cfee318d SP |
756 | /* Returns true when it is possible to generate a builtin pattern for |
757 | the PARTITION of RDG. For the moment we detect only the memset | |
758 | zero pattern. */ | |
759 | ||
760 | static bool | |
761 | can_generate_builtin (struct graph *rdg, bitmap partition) | |
762 | { | |
763 | unsigned i; | |
764 | bitmap_iterator bi; | |
765 | int nb_reads = 0; | |
766 | int nb_writes = 0; | |
767 | int stores_zero = 0; | |
768 | ||
769 | EXECUTE_IF_SET_IN_BITMAP (partition, 0, i, bi) | |
770 | if (RDG_MEM_READS_STMT (rdg, i)) | |
771 | nb_reads++; | |
772 | else if (RDG_MEM_WRITE_STMT (rdg, i)) | |
773 | { | |
774 | nb_writes++; | |
775 | if (stmt_with_adjacent_zero_store_dr_p (RDG_STMT (rdg, i))) | |
776 | stores_zero++; | |
777 | } | |
778 | ||
779 | return stores_zero == 1 && nb_writes == 1 && nb_reads == 0; | |
780 | } | |
781 | ||
782 | /* Returns true when PARTITION1 and PARTITION2 have similar memory | |
783 | accesses in RDG. */ | |
784 | ||
785 | static bool | |
786 | similar_memory_accesses (struct graph *rdg, bitmap partition1, | |
787 | bitmap partition2) | |
788 | { | |
789 | unsigned i, j; | |
790 | bitmap_iterator bi, bj; | |
791 | ||
792 | EXECUTE_IF_SET_IN_BITMAP (partition1, 0, i, bi) | |
793 | if (RDG_MEM_WRITE_STMT (rdg, i) | |
794 | || RDG_MEM_READS_STMT (rdg, i)) | |
795 | EXECUTE_IF_SET_IN_BITMAP (partition2, 0, j, bj) | |
796 | if (RDG_MEM_WRITE_STMT (rdg, j) | |
797 | || RDG_MEM_READS_STMT (rdg, j)) | |
798 | if (rdg_has_similar_memory_accesses (rdg, i, j)) | |
799 | return true; | |
800 | ||
801 | return false; | |
802 | } | |
803 | ||
804 | /* Fuse all the partitions from PARTITIONS that contain similar memory | |
805 | references, i.e., we're taking care of cache locality. This | |
806 | function does not fuse those partitions that contain patterns that | |
807 | can be code generated with builtins. */ | |
808 | ||
809 | static void | |
810 | fuse_partitions_with_similar_memory_accesses (struct graph *rdg, | |
811 | VEC (bitmap, heap) **partitions) | |
812 | { | |
813 | int p1, p2; | |
814 | bitmap partition1, partition2; | |
815 | ||
816 | FOR_EACH_VEC_ELT (bitmap, *partitions, p1, partition1) | |
817 | if (!can_generate_builtin (rdg, partition1)) | |
818 | FOR_EACH_VEC_ELT (bitmap, *partitions, p2, partition2) | |
819 | if (p1 != p2 | |
820 | && !can_generate_builtin (rdg, partition2) | |
821 | && similar_memory_accesses (rdg, partition1, partition2)) | |
822 | { | |
823 | bitmap_ior_into (partition1, partition2); | |
824 | VEC_ordered_remove (bitmap, *partitions, p2); | |
825 | p2--; | |
826 | } | |
827 | } | |
828 | ||
ab221087 SP |
829 | /* Returns true when DEF is an SSA_NAME defined in LOOP and used after |
830 | the LOOP. */ | |
831 | ||
832 | static bool | |
833 | ssa_name_has_uses_outside_loop_p (tree def, loop_p loop) | |
834 | { | |
835 | imm_use_iterator imm_iter; | |
836 | use_operand_p use_p; | |
837 | ||
838 | FOR_EACH_IMM_USE_FAST (use_p, imm_iter, def) | |
839 | if (loop != loop_containing_stmt (USE_STMT (use_p))) | |
840 | return true; | |
841 | ||
842 | return false; | |
843 | } | |
844 | ||
845 | /* Returns true when STMT defines a scalar variable used after the | |
846 | loop. */ | |
847 | ||
848 | static bool | |
849 | stmt_has_scalar_dependences_outside_loop (gimple stmt) | |
850 | { | |
851 | tree name; | |
852 | ||
853 | switch (gimple_code (stmt)) | |
854 | { | |
855 | case GIMPLE_ASSIGN: | |
856 | name = gimple_assign_lhs (stmt); | |
857 | break; | |
858 | ||
859 | case GIMPLE_PHI: | |
860 | name = gimple_phi_result (stmt); | |
861 | break; | |
862 | ||
863 | default: | |
864 | return false; | |
865 | } | |
866 | ||
867 | return TREE_CODE (name) == SSA_NAME | |
868 | && ssa_name_has_uses_outside_loop_p (name, loop_containing_stmt (stmt)); | |
869 | } | |
870 | ||
871 | /* Returns true when STMT will be code generated in a partition of RDG | |
872 | different than PART and that will not be code generated as a | |
873 | builtin. */ | |
874 | ||
875 | static bool | |
876 | stmt_generated_in_another_partition (struct graph *rdg, gimple stmt, int part, | |
877 | VEC (bitmap, heap) *partitions) | |
878 | { | |
879 | int p; | |
880 | bitmap pp; | |
881 | unsigned i; | |
882 | bitmap_iterator bi; | |
883 | ||
884 | FOR_EACH_VEC_ELT (bitmap, partitions, p, pp) | |
885 | if (p != part | |
886 | && !can_generate_builtin (rdg, pp)) | |
887 | EXECUTE_IF_SET_IN_BITMAP (pp, 0, i, bi) | |
888 | if (stmt == RDG_STMT (rdg, i)) | |
889 | return true; | |
890 | ||
891 | return false; | |
892 | } | |
893 | ||
894 | /* For each partition in PARTITIONS that will be code generated using | |
895 | a builtin, add its scalar computations used after the loop to | |
896 | PARTITION. */ | |
897 | ||
898 | static void | |
899 | add_scalar_computations_to_partition (struct graph *rdg, | |
900 | VEC (bitmap, heap) *partitions, | |
901 | bitmap partition) | |
902 | { | |
903 | int p; | |
904 | bitmap pp; | |
905 | unsigned i; | |
906 | bitmap_iterator bi; | |
907 | bitmap l = BITMAP_ALLOC (NULL); | |
908 | bitmap pr = BITMAP_ALLOC (NULL); | |
909 | bool f = false; | |
910 | ||
911 | FOR_EACH_VEC_ELT (bitmap, partitions, p, pp) | |
912 | if (can_generate_builtin (rdg, pp)) | |
913 | EXECUTE_IF_SET_IN_BITMAP (pp, 0, i, bi) | |
914 | if (stmt_has_scalar_dependences_outside_loop (RDG_STMT (rdg, i)) | |
915 | && !stmt_generated_in_another_partition (rdg, RDG_STMT (rdg, i), p, | |
916 | partitions)) | |
917 | rdg_flag_vertex_and_dependent (rdg, i, partition, l, pr, &f); | |
918 | ||
919 | rdg_flag_loop_exits (rdg, l, partition, pr, &f); | |
920 | ||
921 | BITMAP_FREE (pr); | |
922 | BITMAP_FREE (l); | |
923 | } | |
924 | ||
dea61d92 SP |
925 | /* Aggregate several components into a useful partition that is |
926 | registered in the PARTITIONS vector. Partitions will be | |
927 | distributed in different loops. */ | |
928 | ||
929 | static void | |
930 | rdg_build_partitions (struct graph *rdg, VEC (rdgc, heap) *components, | |
931 | VEC (int, heap) **other_stores, | |
932 | VEC (bitmap, heap) **partitions, bitmap processed) | |
933 | { | |
934 | int i; | |
935 | rdgc x; | |
936 | bitmap partition = BITMAP_ALLOC (NULL); | |
937 | ||
ac47786e | 938 | FOR_EACH_VEC_ELT (rdgc, components, i, x) |
dea61d92 SP |
939 | { |
940 | bitmap np; | |
941 | bool part_has_writes = false; | |
942 | int v = VEC_index (int, x->vertices, 0); | |
b8698a0f | 943 | |
dea61d92 SP |
944 | if (bitmap_bit_p (processed, v)) |
945 | continue; | |
b8698a0f | 946 | |
cfee318d | 947 | np = build_rdg_partition_for_component (rdg, x, &part_has_writes); |
dea61d92 SP |
948 | bitmap_ior_into (partition, np); |
949 | bitmap_ior_into (processed, np); | |
950 | BITMAP_FREE (np); | |
951 | ||
952 | if (part_has_writes) | |
953 | { | |
954 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
955 | { | |
956 | fprintf (dump_file, "ldist useful partition:\n"); | |
957 | dump_bitmap (dump_file, partition); | |
958 | } | |
959 | ||
960 | VEC_safe_push (bitmap, heap, *partitions, partition); | |
961 | partition = BITMAP_ALLOC (NULL); | |
962 | } | |
963 | } | |
964 | ||
965 | /* Add the nodes from the RDG that were not marked as processed, and | |
966 | that are used outside the current loop. These are scalar | |
967 | computations that are not yet part of previous partitions. */ | |
968 | for (i = 0; i < rdg->n_vertices; i++) | |
969 | if (!bitmap_bit_p (processed, i) | |
970 | && rdg_defs_used_in_other_loops_p (rdg, i)) | |
971 | VEC_safe_push (int, heap, *other_stores, i); | |
972 | ||
973 | /* If there are still statements left in the OTHER_STORES array, | |
974 | create other components and partitions with these stores and | |
975 | their dependences. */ | |
976 | if (VEC_length (int, *other_stores) > 0) | |
977 | { | |
978 | VEC (rdgc, heap) *comps = VEC_alloc (rdgc, heap, 3); | |
979 | VEC (int, heap) *foo = VEC_alloc (int, heap, 3); | |
980 | ||
981 | rdg_build_components (rdg, *other_stores, &comps); | |
982 | rdg_build_partitions (rdg, comps, &foo, partitions, processed); | |
983 | ||
984 | VEC_free (int, heap, foo); | |
985 | free_rdg_components (comps); | |
986 | } | |
987 | ||
ab221087 SP |
988 | add_scalar_computations_to_partition (rdg, *partitions, partition); |
989 | ||
dea61d92 SP |
990 | /* If there is something left in the last partition, save it. */ |
991 | if (bitmap_count_bits (partition) > 0) | |
992 | VEC_safe_push (bitmap, heap, *partitions, partition); | |
993 | else | |
994 | BITMAP_FREE (partition); | |
cfee318d SP |
995 | |
996 | fuse_partitions_with_similar_memory_accesses (rdg, partitions); | |
dea61d92 SP |
997 | } |
998 | ||
999 | /* Dump to FILE the PARTITIONS. */ | |
1000 | ||
1001 | static void | |
1002 | dump_rdg_partitions (FILE *file, VEC (bitmap, heap) *partitions) | |
1003 | { | |
1004 | int i; | |
1005 | bitmap partition; | |
1006 | ||
ac47786e | 1007 | FOR_EACH_VEC_ELT (bitmap, partitions, i, partition) |
dea61d92 SP |
1008 | debug_bitmap_file (file, partition); |
1009 | } | |
1010 | ||
1011 | /* Debug PARTITIONS. */ | |
1012 | extern void debug_rdg_partitions (VEC (bitmap, heap) *); | |
1013 | ||
24e47c76 | 1014 | DEBUG_FUNCTION void |
dea61d92 SP |
1015 | debug_rdg_partitions (VEC (bitmap, heap) *partitions) |
1016 | { | |
1017 | dump_rdg_partitions (stderr, partitions); | |
1018 | } | |
1019 | ||
2b8aee8e SP |
1020 | /* Returns the number of read and write operations in the RDG. */ |
1021 | ||
1022 | static int | |
1023 | number_of_rw_in_rdg (struct graph *rdg) | |
1024 | { | |
1025 | int i, res = 0; | |
1026 | ||
1027 | for (i = 0; i < rdg->n_vertices; i++) | |
1028 | { | |
1029 | if (RDG_MEM_WRITE_STMT (rdg, i)) | |
1030 | ++res; | |
1031 | ||
1032 | if (RDG_MEM_READS_STMT (rdg, i)) | |
1033 | ++res; | |
1034 | } | |
1035 | ||
1036 | return res; | |
1037 | } | |
1038 | ||
1039 | /* Returns the number of read and write operations in a PARTITION of | |
1040 | the RDG. */ | |
1041 | ||
1042 | static int | |
1043 | number_of_rw_in_partition (struct graph *rdg, bitmap partition) | |
1044 | { | |
1045 | int res = 0; | |
1046 | unsigned i; | |
1047 | bitmap_iterator ii; | |
1048 | ||
1049 | EXECUTE_IF_SET_IN_BITMAP (partition, 0, i, ii) | |
1050 | { | |
1051 | if (RDG_MEM_WRITE_STMT (rdg, i)) | |
1052 | ++res; | |
1053 | ||
1054 | if (RDG_MEM_READS_STMT (rdg, i)) | |
1055 | ++res; | |
1056 | } | |
1057 | ||
1058 | return res; | |
1059 | } | |
1060 | ||
1061 | /* Returns true when one of the PARTITIONS contains all the read or | |
1062 | write operations of RDG. */ | |
1063 | ||
1064 | static bool | |
1065 | partition_contains_all_rw (struct graph *rdg, VEC (bitmap, heap) *partitions) | |
1066 | { | |
1067 | int i; | |
1068 | bitmap partition; | |
1069 | int nrw = number_of_rw_in_rdg (rdg); | |
1070 | ||
ac47786e | 1071 | FOR_EACH_VEC_ELT (bitmap, partitions, i, partition) |
2b8aee8e SP |
1072 | if (nrw == number_of_rw_in_partition (rdg, partition)) |
1073 | return true; | |
1074 | ||
1075 | return false; | |
1076 | } | |
1077 | ||
dea61d92 SP |
1078 | /* Generate code from STARTING_VERTICES in RDG. Returns the number of |
1079 | distributed loops. */ | |
1080 | ||
1081 | static int | |
1082 | ldist_gen (struct loop *loop, struct graph *rdg, | |
1083 | VEC (int, heap) *starting_vertices) | |
1084 | { | |
1085 | int i, nbp; | |
1086 | VEC (rdgc, heap) *components = VEC_alloc (rdgc, heap, 3); | |
1087 | VEC (bitmap, heap) *partitions = VEC_alloc (bitmap, heap, 3); | |
1088 | VEC (int, heap) *other_stores = VEC_alloc (int, heap, 3); | |
1089 | bitmap partition, processed = BITMAP_ALLOC (NULL); | |
1090 | ||
1091 | remaining_stmts = BITMAP_ALLOC (NULL); | |
1092 | upstream_mem_writes = BITMAP_ALLOC (NULL); | |
1093 | ||
1094 | for (i = 0; i < rdg->n_vertices; i++) | |
1095 | { | |
1096 | bitmap_set_bit (remaining_stmts, i); | |
1097 | ||
1098 | /* Save in OTHER_STORES all the memory writes that are not in | |
1099 | STARTING_VERTICES. */ | |
1100 | if (RDG_MEM_WRITE_STMT (rdg, i)) | |
1101 | { | |
1102 | int v; | |
1103 | unsigned j; | |
1104 | bool found = false; | |
1105 | ||
ac47786e | 1106 | FOR_EACH_VEC_ELT (int, starting_vertices, j, v) |
dea61d92 SP |
1107 | if (i == v) |
1108 | { | |
1109 | found = true; | |
1110 | break; | |
1111 | } | |
1112 | ||
1113 | if (!found) | |
1114 | VEC_safe_push (int, heap, other_stores, i); | |
1115 | } | |
1116 | } | |
1117 | ||
1118 | mark_nodes_having_upstream_mem_writes (rdg); | |
1119 | rdg_build_components (rdg, starting_vertices, &components); | |
1120 | rdg_build_partitions (rdg, components, &other_stores, &partitions, | |
1121 | processed); | |
1122 | BITMAP_FREE (processed); | |
1123 | nbp = VEC_length (bitmap, partitions); | |
1124 | ||
2b8aee8e SP |
1125 | if (nbp <= 1 |
1126 | || partition_contains_all_rw (rdg, partitions)) | |
dea61d92 SP |
1127 | goto ldist_done; |
1128 | ||
1129 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1130 | dump_rdg_partitions (dump_file, partitions); | |
1131 | ||
ac47786e | 1132 | FOR_EACH_VEC_ELT (bitmap, partitions, i, partition) |
dea61d92 SP |
1133 | if (!generate_code_for_partition (loop, partition, i < nbp - 1)) |
1134 | goto ldist_done; | |
1135 | ||
1136 | rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa); | |
1137 | update_ssa (TODO_update_ssa_only_virtuals | TODO_update_ssa); | |
1138 | ||
1139 | ldist_done: | |
1140 | ||
1141 | BITMAP_FREE (remaining_stmts); | |
1142 | BITMAP_FREE (upstream_mem_writes); | |
1143 | ||
ac47786e | 1144 | FOR_EACH_VEC_ELT (bitmap, partitions, i, partition) |
dea61d92 SP |
1145 | BITMAP_FREE (partition); |
1146 | ||
1147 | VEC_free (int, heap, other_stores); | |
1148 | VEC_free (bitmap, heap, partitions); | |
1149 | free_rdg_components (components); | |
1150 | return nbp; | |
1151 | } | |
1152 | ||
1153 | /* Distributes the code from LOOP in such a way that producer | |
1154 | statements are placed before consumer statements. When STMTS is | |
1155 | NULL, performs the maximal distribution, if STMTS is not NULL, | |
1156 | tries to separate only these statements from the LOOP's body. | |
1157 | Returns the number of distributed loops. */ | |
1158 | ||
1159 | static int | |
726a989a | 1160 | distribute_loop (struct loop *loop, VEC (gimple, heap) *stmts) |
dea61d92 | 1161 | { |
e96d7dd7 | 1162 | int res = 0; |
dea61d92 | 1163 | struct graph *rdg; |
726a989a | 1164 | gimple s; |
dea61d92 SP |
1165 | unsigned i; |
1166 | VEC (int, heap) *vertices; | |
01be8516 SP |
1167 | VEC (ddr_p, heap) *dependence_relations; |
1168 | VEC (data_reference_p, heap) *datarefs; | |
1169 | VEC (loop_p, heap) *loop_nest; | |
dea61d92 SP |
1170 | |
1171 | if (loop->num_nodes > 2) | |
1172 | { | |
1173 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1174 | fprintf (dump_file, | |
1175 | "FIXME: Loop %d not distributed: it has more than two basic blocks.\n", | |
1176 | loop->num); | |
1177 | ||
1178 | return res; | |
1179 | } | |
1180 | ||
01be8516 SP |
1181 | datarefs = VEC_alloc (data_reference_p, heap, 10); |
1182 | dependence_relations = VEC_alloc (ddr_p, heap, 100); | |
1183 | loop_nest = VEC_alloc (loop_p, heap, 3); | |
1184 | rdg = build_rdg (loop, &loop_nest, &dependence_relations, &datarefs); | |
dea61d92 SP |
1185 | |
1186 | if (!rdg) | |
1187 | { | |
1188 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1189 | fprintf (dump_file, | |
1190 | "FIXME: Loop %d not distributed: failed to build the RDG.\n", | |
1191 | loop->num); | |
1192 | ||
01be8516 SP |
1193 | free_dependence_relations (dependence_relations); |
1194 | free_data_refs (datarefs); | |
1195 | VEC_free (loop_p, heap, loop_nest); | |
dea61d92 SP |
1196 | return res; |
1197 | } | |
1198 | ||
1199 | vertices = VEC_alloc (int, heap, 3); | |
1200 | ||
1201 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1202 | dump_rdg (dump_file, rdg); | |
1203 | ||
ac47786e | 1204 | FOR_EACH_VEC_ELT (gimple, stmts, i, s) |
dea61d92 SP |
1205 | { |
1206 | int v = rdg_vertex_for_stmt (rdg, s); | |
1207 | ||
1208 | if (v >= 0) | |
1209 | { | |
1210 | VEC_safe_push (int, heap, vertices, v); | |
1211 | ||
1212 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1213 | fprintf (dump_file, | |
1214 | "ldist asked to generate code for vertex %d\n", v); | |
1215 | } | |
1216 | } | |
1217 | ||
1218 | res = ldist_gen (loop, rdg, vertices); | |
1219 | VEC_free (int, heap, vertices); | |
1220 | free_rdg (rdg); | |
01be8516 SP |
1221 | free_dependence_relations (dependence_relations); |
1222 | free_data_refs (datarefs); | |
1223 | VEC_free (loop_p, heap, loop_nest); | |
dea61d92 SP |
1224 | return res; |
1225 | } | |
1226 | ||
1227 | /* Distribute all loops in the current function. */ | |
1228 | ||
1229 | static unsigned int | |
1230 | tree_loop_distribution (void) | |
1231 | { | |
1232 | struct loop *loop; | |
1233 | loop_iterator li; | |
1234 | int nb_generated_loops = 0; | |
1235 | ||
1236 | FOR_EACH_LOOP (li, loop, 0) | |
1237 | { | |
a3357f7d | 1238 | VEC (gimple, heap) *work_list = NULL; |
0e20c89f | 1239 | int num = loop->num; |
a3357f7d RG |
1240 | |
1241 | /* If the loop doesn't have a single exit we will fail anyway, | |
1242 | so do that early. */ | |
1243 | if (!single_exit (loop)) | |
1244 | continue; | |
dea61d92 | 1245 | |
20769d5e SP |
1246 | /* If both flag_tree_loop_distribute_patterns and |
1247 | flag_tree_loop_distribution are set, then only | |
1248 | distribute_patterns is executed. */ | |
1249 | if (flag_tree_loop_distribute_patterns) | |
1250 | { | |
1251 | /* With the following working list, we're asking | |
1252 | distribute_loop to separate from the rest of the loop the | |
1253 | stores of the form "A[i] = 0". */ | |
1254 | stores_zero_from_loop (loop, &work_list); | |
1255 | ||
1256 | /* Do nothing if there are no patterns to be distributed. */ | |
1257 | if (VEC_length (gimple, work_list) > 0) | |
1258 | nb_generated_loops = distribute_loop (loop, work_list); | |
1259 | } | |
1260 | else if (flag_tree_loop_distribution) | |
1261 | { | |
1262 | /* With the following working list, we're asking | |
1263 | distribute_loop to separate the stores of the loop: when | |
1264 | dependences allow, it will end on having one store per | |
1265 | loop. */ | |
1266 | stores_from_loop (loop, &work_list); | |
1267 | ||
1268 | /* A simple heuristic for cache locality is to not split | |
1269 | stores to the same array. Without this call, an unrolled | |
1270 | loop would be split into as many loops as unroll factor, | |
1271 | each loop storing in the same array. */ | |
1272 | remove_similar_memory_refs (&work_list); | |
1273 | ||
1274 | nb_generated_loops = distribute_loop (loop, work_list); | |
1275 | } | |
dea61d92 SP |
1276 | |
1277 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1278 | { | |
1279 | if (nb_generated_loops > 1) | |
1280 | fprintf (dump_file, "Loop %d distributed: split to %d loops.\n", | |
0e20c89f | 1281 | num, nb_generated_loops); |
dea61d92 | 1282 | else |
0e20c89f | 1283 | fprintf (dump_file, "Loop %d is the same.\n", num); |
dea61d92 SP |
1284 | } |
1285 | ||
1286 | verify_loop_structure (); | |
1287 | ||
726a989a | 1288 | VEC_free (gimple, heap, work_list); |
dea61d92 SP |
1289 | } |
1290 | ||
5006671f | 1291 | return 0; |
dea61d92 SP |
1292 | } |
1293 | ||
1294 | static bool | |
1295 | gate_tree_loop_distribution (void) | |
1296 | { | |
20769d5e SP |
1297 | return flag_tree_loop_distribution |
1298 | || flag_tree_loop_distribute_patterns; | |
dea61d92 SP |
1299 | } |
1300 | ||
8ddbbcae | 1301 | struct gimple_opt_pass pass_loop_distribution = |
dea61d92 | 1302 | { |
8ddbbcae JH |
1303 | { |
1304 | GIMPLE_PASS, | |
dea61d92 SP |
1305 | "ldist", /* name */ |
1306 | gate_tree_loop_distribution, /* gate */ | |
1307 | tree_loop_distribution, /* execute */ | |
1308 | NULL, /* sub */ | |
1309 | NULL, /* next */ | |
1310 | 0, /* static_pass_number */ | |
1311 | TV_TREE_LOOP_DISTRIBUTION, /* tv_id */ | |
1312 | PROP_cfg | PROP_ssa, /* properties_required */ | |
1313 | 0, /* properties_provided */ | |
1314 | 0, /* properties_destroyed */ | |
1315 | 0, /* todo_flags_start */ | |
22c5fa5f | 1316 | 0 /* todo_flags_finish */ |
8ddbbcae | 1317 | } |
dea61d92 | 1318 | }; |