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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; |
0d82a1c8 RG |
245 | tree x = fold_build2_loc (loc, MULT_EXPR, size_type_node, |
246 | fold_convert_loc (loc, size_type_node, nb_iter), | |
247 | fold_convert_loc (loc, size_type_node, | |
248 | TYPE_SIZE_UNIT (TREE_TYPE (op)))); | |
fc81a369 RH |
249 | x = force_gimple_operand (x, &stmts, true, NULL); |
250 | gimple_seq_add_seq (stmt_list, stmts); | |
3661e899 | 251 | |
fc81a369 | 252 | return x; |
3661e899 TB |
253 | } |
254 | ||
dea61d92 SP |
255 | /* Generate a call to memset. Return true when the operation succeeded. */ |
256 | ||
cfee318d | 257 | static void |
726a989a RB |
258 | generate_memset_zero (gimple stmt, tree op0, tree nb_iter, |
259 | gimple_stmt_iterator bsi) | |
dea61d92 | 260 | { |
fc81a369 | 261 | tree addr_base, nb_bytes; |
dea61d92 | 262 | bool res = false; |
fc81a369 | 263 | gimple_seq stmt_list = NULL, stmts; |
726a989a | 264 | gimple fn_call; |
fc81a369 | 265 | tree mem, fn; |
dea61d92 | 266 | struct data_reference *dr = XCNEW (struct data_reference); |
db3927fb | 267 | location_t loc = gimple_location (stmt); |
dea61d92 | 268 | |
dea61d92 SP |
269 | DR_STMT (dr) = stmt; |
270 | DR_REF (dr) = op0; | |
4e4452b6 | 271 | res = dr_analyze_innermost (dr, loop_containing_stmt (stmt)); |
cfee318d | 272 | gcc_assert (res && stride_of_unit_type_p (DR_STEP (dr), TREE_TYPE (op0))); |
5e37ea0e SP |
273 | |
274 | nb_bytes = build_size_arg_loc (loc, nb_iter, op0, &stmt_list); | |
275 | addr_base = size_binop_loc (loc, PLUS_EXPR, DR_OFFSET (dr), DR_INIT (dr)); | |
276 | addr_base = fold_convert_loc (loc, sizetype, addr_base); | |
dea61d92 SP |
277 | |
278 | /* Test for a negative stride, iterating over every element. */ | |
0d82a1c8 | 279 | if (tree_int_cst_sgn (DR_STEP (dr)) == -1) |
dea61d92 | 280 | { |
fc81a369 RH |
281 | addr_base = size_binop_loc (loc, MINUS_EXPR, addr_base, |
282 | fold_convert_loc (loc, sizetype, nb_bytes)); | |
6edd8198 AM |
283 | addr_base = size_binop_loc (loc, PLUS_EXPR, addr_base, |
284 | TYPE_SIZE_UNIT (TREE_TYPE (op0))); | |
dea61d92 | 285 | } |
dea61d92 | 286 | |
5d49b6a7 RG |
287 | addr_base = fold_build_pointer_plus_loc (loc, |
288 | DR_BASE_ADDRESS (dr), addr_base); | |
dea61d92 | 289 | mem = force_gimple_operand (addr_base, &stmts, true, NULL); |
726a989a | 290 | gimple_seq_add_seq (&stmt_list, stmts); |
dea61d92 | 291 | |
e79983f4 | 292 | fn = build_fold_addr_expr (builtin_decl_implicit (BUILT_IN_MEMSET)); |
726a989a RB |
293 | fn_call = gimple_build_call (fn, 3, mem, integer_zero_node, nb_bytes); |
294 | gimple_seq_add_stmt (&stmt_list, fn_call); | |
726a989a | 295 | gsi_insert_seq_after (&bsi, stmt_list, GSI_CONTINUE_LINKING); |
dea61d92 SP |
296 | |
297 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
298 | fprintf (dump_file, "generated memset zero\n"); | |
299 | ||
dea61d92 | 300 | free_data_ref (dr); |
dea61d92 SP |
301 | } |
302 | ||
303 | /* Tries to generate a builtin function for the instructions of LOOP | |
304 | pointed to by the bits set in PARTITION. Returns true when the | |
305 | operation succeeded. */ | |
306 | ||
307 | static bool | |
308 | generate_builtin (struct loop *loop, bitmap partition, bool copy_p) | |
309 | { | |
310 | bool res = false; | |
311 | unsigned i, x = 0; | |
312 | basic_block *bbs; | |
726a989a | 313 | gimple write = NULL; |
726a989a | 314 | gimple_stmt_iterator bsi; |
dea61d92 SP |
315 | tree nb_iter = number_of_exit_cond_executions (loop); |
316 | ||
317 | if (!nb_iter || nb_iter == chrec_dont_know) | |
318 | return false; | |
319 | ||
320 | bbs = get_loop_body_in_dom_order (loop); | |
321 | ||
322 | for (i = 0; i < loop->num_nodes; i++) | |
323 | { | |
324 | basic_block bb = bbs[i]; | |
dea61d92 | 325 | |
726a989a | 326 | for (bsi = gsi_start_phis (bb); !gsi_end_p (bsi); gsi_next (&bsi)) |
dea61d92 SP |
327 | x++; |
328 | ||
726a989a | 329 | for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) |
dea61d92 | 330 | { |
726a989a | 331 | gimple stmt = gsi_stmt (bsi); |
dea61d92 | 332 | |
b03c3082 JJ |
333 | if (gimple_code (stmt) != GIMPLE_LABEL |
334 | && !is_gimple_debug (stmt) | |
335 | && bitmap_bit_p (partition, x++) | |
726a989a RB |
336 | && is_gimple_assign (stmt) |
337 | && !is_gimple_reg (gimple_assign_lhs (stmt))) | |
dea61d92 SP |
338 | { |
339 | /* Don't generate the builtins when there are more than | |
340 | one memory write. */ | |
341 | if (write != NULL) | |
342 | goto end; | |
343 | ||
344 | write = stmt; | |
6edd8198 AM |
345 | if (bb == loop->latch) |
346 | nb_iter = number_of_latch_executions (loop); | |
dea61d92 SP |
347 | } |
348 | } | |
349 | } | |
350 | ||
cfee318d | 351 | if (!stmt_with_adjacent_zero_store_dr_p (write)) |
dea61d92 SP |
352 | goto end; |
353 | ||
354 | /* The new statements will be placed before LOOP. */ | |
726a989a | 355 | bsi = gsi_last_bb (loop_preheader_edge (loop)->src); |
cfee318d SP |
356 | generate_memset_zero (write, gimple_assign_lhs (write), nb_iter, bsi); |
357 | res = true; | |
dea61d92 SP |
358 | |
359 | /* If this is the last partition for which we generate code, we have | |
360 | to destroy the loop. */ | |
cfee318d | 361 | if (!copy_p) |
dea61d92 SP |
362 | { |
363 | unsigned nbbs = loop->num_nodes; | |
5923c6c3 RG |
364 | edge exit = single_exit (loop); |
365 | basic_block src = loop_preheader_edge (loop)->src, dest = exit->dest; | |
366 | redirect_edge_pred (exit, src); | |
367 | exit->flags &= ~(EDGE_TRUE_VALUE|EDGE_FALSE_VALUE); | |
368 | exit->flags |= EDGE_FALLTHRU; | |
dea61d92 | 369 | cancel_loop_tree (loop); |
5923c6c3 | 370 | rescan_loop_exit (exit, false, true); |
dea61d92 SP |
371 | |
372 | for (i = 0; i < nbbs; i++) | |
373 | delete_basic_block (bbs[i]); | |
d5e54bc1 KH |
374 | |
375 | set_immediate_dominator (CDI_DOMINATORS, dest, | |
376 | recompute_dominator (CDI_DOMINATORS, dest)); | |
dea61d92 SP |
377 | } |
378 | ||
379 | end: | |
380 | free (bbs); | |
381 | return res; | |
382 | } | |
383 | ||
384 | /* Generates code for PARTITION. For simple loops, this function can | |
385 | generate a built-in. */ | |
386 | ||
387 | static bool | |
388 | generate_code_for_partition (struct loop *loop, bitmap partition, bool copy_p) | |
389 | { | |
390 | if (generate_builtin (loop, partition, copy_p)) | |
391 | return true; | |
392 | ||
393 | return generate_loops_for_partition (loop, partition, copy_p); | |
394 | } | |
395 | ||
396 | ||
397 | /* Returns true if the node V of RDG cannot be recomputed. */ | |
398 | ||
399 | static bool | |
400 | rdg_cannot_recompute_vertex_p (struct graph *rdg, int v) | |
401 | { | |
402 | if (RDG_MEM_WRITE_STMT (rdg, v)) | |
403 | return true; | |
404 | ||
405 | return false; | |
406 | } | |
407 | ||
408 | /* Returns true when the vertex V has already been generated in the | |
409 | current partition (V is in PROCESSED), or when V belongs to another | |
410 | partition and cannot be recomputed (V is not in REMAINING_STMTS). */ | |
411 | ||
412 | static inline bool | |
413 | already_processed_vertex_p (bitmap processed, int v) | |
414 | { | |
415 | return (bitmap_bit_p (processed, v) | |
416 | || !bitmap_bit_p (remaining_stmts, v)); | |
417 | } | |
418 | ||
419 | /* Returns NULL when there is no anti-dependence among the successors | |
420 | of vertex V, otherwise returns the edge with the anti-dep. */ | |
421 | ||
422 | static struct graph_edge * | |
423 | has_anti_dependence (struct vertex *v) | |
424 | { | |
425 | struct graph_edge *e; | |
426 | ||
427 | if (v->succ) | |
428 | for (e = v->succ; e; e = e->succ_next) | |
429 | if (RDGE_TYPE (e) == anti_dd) | |
430 | return e; | |
431 | ||
432 | return NULL; | |
433 | } | |
434 | ||
435 | /* Returns true when V has an anti-dependence edge among its successors. */ | |
436 | ||
437 | static bool | |
438 | predecessor_has_mem_write (struct graph *rdg, struct vertex *v) | |
439 | { | |
440 | struct graph_edge *e; | |
441 | ||
442 | if (v->pred) | |
443 | for (e = v->pred; e; e = e->pred_next) | |
444 | if (bitmap_bit_p (upstream_mem_writes, e->src) | |
445 | /* Don't consider flow channels: a write to memory followed | |
446 | by a read from memory. These channels allow the split of | |
447 | the RDG in different partitions. */ | |
448 | && !RDG_MEM_WRITE_STMT (rdg, e->src)) | |
449 | return true; | |
450 | ||
451 | return false; | |
452 | } | |
453 | ||
454 | /* Initializes the upstream_mem_writes bitmap following the | |
455 | information from RDG. */ | |
456 | ||
457 | static void | |
458 | mark_nodes_having_upstream_mem_writes (struct graph *rdg) | |
459 | { | |
460 | int v, x; | |
461 | bitmap seen = BITMAP_ALLOC (NULL); | |
462 | ||
463 | for (v = rdg->n_vertices - 1; v >= 0; v--) | |
464 | if (!bitmap_bit_p (seen, v)) | |
465 | { | |
466 | unsigned i; | |
467 | VEC (int, heap) *nodes = VEC_alloc (int, heap, 3); | |
dea61d92 SP |
468 | |
469 | graphds_dfs (rdg, &v, 1, &nodes, false, NULL); | |
470 | ||
ac47786e | 471 | FOR_EACH_VEC_ELT (int, nodes, i, x) |
dea61d92 | 472 | { |
fcaa4ca4 | 473 | if (!bitmap_set_bit (seen, x)) |
dea61d92 SP |
474 | continue; |
475 | ||
dea61d92 SP |
476 | if (RDG_MEM_WRITE_STMT (rdg, x) |
477 | || predecessor_has_mem_write (rdg, &(rdg->vertices[x])) | |
478 | /* In anti dependences the read should occur before | |
479 | the write, this is why both the read and the write | |
480 | should be placed in the same partition. */ | |
481 | || has_anti_dependence (&(rdg->vertices[x]))) | |
482 | { | |
dea61d92 SP |
483 | bitmap_set_bit (upstream_mem_writes, x); |
484 | } | |
485 | } | |
486 | ||
487 | VEC_free (int, heap, nodes); | |
488 | } | |
489 | } | |
490 | ||
491 | /* Returns true when vertex u has a memory write node as a predecessor | |
492 | in RDG. */ | |
493 | ||
494 | static bool | |
495 | has_upstream_mem_writes (int u) | |
496 | { | |
497 | return bitmap_bit_p (upstream_mem_writes, u); | |
498 | } | |
499 | ||
500 | static void rdg_flag_vertex_and_dependent (struct graph *, int, bitmap, bitmap, | |
501 | bitmap, bool *); | |
502 | ||
dea61d92 SP |
503 | /* Flag the uses of U stopping following the information from |
504 | upstream_mem_writes. */ | |
505 | ||
506 | static void | |
507 | rdg_flag_uses (struct graph *rdg, int u, bitmap partition, bitmap loops, | |
508 | bitmap processed, bool *part_has_writes) | |
509 | { | |
dea61d92 SP |
510 | use_operand_p use_p; |
511 | struct vertex *x = &(rdg->vertices[u]); | |
726a989a | 512 | gimple stmt = RDGV_STMT (x); |
dea61d92 SP |
513 | struct graph_edge *anti_dep = has_anti_dependence (x); |
514 | ||
515 | /* Keep in the same partition the destination of an antidependence, | |
516 | because this is a store to the exact same location. Putting this | |
517 | in another partition is bad for cache locality. */ | |
518 | if (anti_dep) | |
519 | { | |
520 | int v = anti_dep->dest; | |
521 | ||
522 | if (!already_processed_vertex_p (processed, v)) | |
523 | rdg_flag_vertex_and_dependent (rdg, v, partition, loops, | |
524 | processed, part_has_writes); | |
525 | } | |
526 | ||
726a989a | 527 | if (gimple_code (stmt) != GIMPLE_PHI) |
dea61d92 | 528 | { |
5006671f | 529 | if ((use_p = gimple_vuse_op (stmt)) != NULL_USE_OPERAND_P) |
dea61d92 SP |
530 | { |
531 | tree use = USE_FROM_PTR (use_p); | |
532 | ||
533 | if (TREE_CODE (use) == SSA_NAME) | |
534 | { | |
726a989a | 535 | gimple def_stmt = SSA_NAME_DEF_STMT (use); |
dea61d92 SP |
536 | int v = rdg_vertex_for_stmt (rdg, def_stmt); |
537 | ||
538 | if (v >= 0 | |
539 | && !already_processed_vertex_p (processed, v)) | |
540 | rdg_flag_vertex_and_dependent (rdg, v, partition, loops, | |
541 | processed, part_has_writes); | |
542 | } | |
543 | } | |
544 | } | |
545 | ||
726a989a | 546 | if (is_gimple_assign (stmt) && has_upstream_mem_writes (u)) |
dea61d92 | 547 | { |
726a989a | 548 | tree op0 = gimple_assign_lhs (stmt); |
dea61d92 SP |
549 | |
550 | /* Scalar channels don't have enough space for transmitting data | |
551 | between tasks, unless we add more storage by privatizing. */ | |
552 | if (is_gimple_reg (op0)) | |
553 | { | |
554 | use_operand_p use_p; | |
555 | imm_use_iterator iter; | |
556 | ||
557 | FOR_EACH_IMM_USE_FAST (use_p, iter, op0) | |
558 | { | |
559 | int v = rdg_vertex_for_stmt (rdg, USE_STMT (use_p)); | |
560 | ||
561 | if (!already_processed_vertex_p (processed, v)) | |
562 | rdg_flag_vertex_and_dependent (rdg, v, partition, loops, | |
563 | processed, part_has_writes); | |
564 | } | |
565 | } | |
566 | } | |
567 | } | |
568 | ||
569 | /* Flag V from RDG as part of PARTITION, and also flag its loop number | |
570 | in LOOPS. */ | |
571 | ||
572 | static void | |
573 | rdg_flag_vertex (struct graph *rdg, int v, bitmap partition, bitmap loops, | |
574 | bool *part_has_writes) | |
575 | { | |
576 | struct loop *loop; | |
577 | ||
fcaa4ca4 | 578 | if (!bitmap_set_bit (partition, v)) |
dea61d92 SP |
579 | return; |
580 | ||
581 | loop = loop_containing_stmt (RDG_STMT (rdg, v)); | |
582 | bitmap_set_bit (loops, loop->num); | |
dea61d92 SP |
583 | |
584 | if (rdg_cannot_recompute_vertex_p (rdg, v)) | |
585 | { | |
586 | *part_has_writes = true; | |
587 | bitmap_clear_bit (remaining_stmts, v); | |
588 | } | |
589 | } | |
590 | ||
591 | /* Flag in the bitmap PARTITION the vertex V and all its predecessors. | |
fa10beec | 592 | Also flag their loop number in LOOPS. */ |
dea61d92 SP |
593 | |
594 | static void | |
595 | rdg_flag_vertex_and_dependent (struct graph *rdg, int v, bitmap partition, | |
596 | bitmap loops, bitmap processed, | |
597 | bool *part_has_writes) | |
598 | { | |
599 | unsigned i; | |
600 | VEC (int, heap) *nodes = VEC_alloc (int, heap, 3); | |
601 | int x; | |
602 | ||
603 | bitmap_set_bit (processed, v); | |
604 | rdg_flag_uses (rdg, v, partition, loops, processed, part_has_writes); | |
605 | graphds_dfs (rdg, &v, 1, &nodes, false, remaining_stmts); | |
606 | rdg_flag_vertex (rdg, v, partition, loops, part_has_writes); | |
607 | ||
ac47786e | 608 | FOR_EACH_VEC_ELT (int, nodes, i, x) |
dea61d92 SP |
609 | if (!already_processed_vertex_p (processed, x)) |
610 | rdg_flag_vertex_and_dependent (rdg, x, partition, loops, processed, | |
611 | part_has_writes); | |
612 | ||
613 | VEC_free (int, heap, nodes); | |
614 | } | |
615 | ||
616 | /* Initialize CONDS with all the condition statements from the basic | |
617 | blocks of LOOP. */ | |
618 | ||
619 | static void | |
726a989a | 620 | collect_condition_stmts (struct loop *loop, VEC (gimple, heap) **conds) |
dea61d92 SP |
621 | { |
622 | unsigned i; | |
623 | edge e; | |
624 | VEC (edge, heap) *exits = get_loop_exit_edges (loop); | |
625 | ||
ac47786e | 626 | FOR_EACH_VEC_ELT (edge, exits, i, e) |
dea61d92 | 627 | { |
726a989a | 628 | gimple cond = last_stmt (e->src); |
dea61d92 SP |
629 | |
630 | if (cond) | |
726a989a | 631 | VEC_safe_push (gimple, heap, *conds, cond); |
dea61d92 SP |
632 | } |
633 | ||
634 | VEC_free (edge, heap, exits); | |
635 | } | |
636 | ||
637 | /* Add to PARTITION all the exit condition statements for LOOPS | |
638 | together with all their dependent statements determined from | |
639 | RDG. */ | |
640 | ||
641 | static void | |
642 | rdg_flag_loop_exits (struct graph *rdg, bitmap loops, bitmap partition, | |
643 | bitmap processed, bool *part_has_writes) | |
644 | { | |
645 | unsigned i; | |
646 | bitmap_iterator bi; | |
726a989a | 647 | VEC (gimple, heap) *conds = VEC_alloc (gimple, heap, 3); |
dea61d92 SP |
648 | |
649 | EXECUTE_IF_SET_IN_BITMAP (loops, 0, i, bi) | |
650 | collect_condition_stmts (get_loop (i), &conds); | |
651 | ||
726a989a | 652 | while (!VEC_empty (gimple, conds)) |
dea61d92 | 653 | { |
726a989a | 654 | gimple cond = VEC_pop (gimple, conds); |
dea61d92 SP |
655 | int v = rdg_vertex_for_stmt (rdg, cond); |
656 | bitmap new_loops = BITMAP_ALLOC (NULL); | |
657 | ||
658 | if (!already_processed_vertex_p (processed, v)) | |
659 | rdg_flag_vertex_and_dependent (rdg, v, partition, new_loops, processed, | |
660 | part_has_writes); | |
661 | ||
662 | EXECUTE_IF_SET_IN_BITMAP (new_loops, 0, i, bi) | |
fcaa4ca4 NF |
663 | if (bitmap_set_bit (loops, i)) |
664 | collect_condition_stmts (get_loop (i), &conds); | |
dea61d92 SP |
665 | |
666 | BITMAP_FREE (new_loops); | |
667 | } | |
01be8516 SP |
668 | |
669 | VEC_free (gimple, heap, conds); | |
dea61d92 SP |
670 | } |
671 | ||
dea61d92 SP |
672 | /* Returns a bitmap in which all the statements needed for computing |
673 | the strongly connected component C of the RDG are flagged, also | |
674 | including the loop exit conditions. */ | |
675 | ||
676 | static bitmap | |
677 | build_rdg_partition_for_component (struct graph *rdg, rdgc c, | |
cfee318d | 678 | bool *part_has_writes) |
dea61d92 SP |
679 | { |
680 | int i, v; | |
681 | bitmap partition = BITMAP_ALLOC (NULL); | |
682 | bitmap loops = BITMAP_ALLOC (NULL); | |
683 | bitmap processed = BITMAP_ALLOC (NULL); | |
684 | ||
ac47786e | 685 | FOR_EACH_VEC_ELT (int, c->vertices, i, v) |
dea61d92 SP |
686 | if (!already_processed_vertex_p (processed, v)) |
687 | rdg_flag_vertex_and_dependent (rdg, v, partition, loops, processed, | |
688 | part_has_writes); | |
689 | ||
dea61d92 SP |
690 | rdg_flag_loop_exits (rdg, loops, partition, processed, part_has_writes); |
691 | ||
692 | BITMAP_FREE (processed); | |
693 | BITMAP_FREE (loops); | |
694 | return partition; | |
695 | } | |
696 | ||
697 | /* Free memory for COMPONENTS. */ | |
698 | ||
699 | static void | |
700 | free_rdg_components (VEC (rdgc, heap) *components) | |
701 | { | |
702 | int i; | |
703 | rdgc x; | |
704 | ||
ac47786e | 705 | FOR_EACH_VEC_ELT (rdgc, components, i, x) |
dea61d92 SP |
706 | { |
707 | VEC_free (int, heap, x->vertices); | |
708 | free (x); | |
709 | } | |
01be8516 SP |
710 | |
711 | VEC_free (rdgc, heap, components); | |
dea61d92 SP |
712 | } |
713 | ||
714 | /* Build the COMPONENTS vector with the strongly connected components | |
715 | of RDG in which the STARTING_VERTICES occur. */ | |
716 | ||
717 | static void | |
b8698a0f | 718 | rdg_build_components (struct graph *rdg, VEC (int, heap) *starting_vertices, |
dea61d92 SP |
719 | VEC (rdgc, heap) **components) |
720 | { | |
721 | int i, v; | |
722 | bitmap saved_components = BITMAP_ALLOC (NULL); | |
723 | int n_components = graphds_scc (rdg, NULL); | |
724 | VEC (int, heap) **all_components = XNEWVEC (VEC (int, heap) *, n_components); | |
725 | ||
726 | for (i = 0; i < n_components; i++) | |
727 | all_components[i] = VEC_alloc (int, heap, 3); | |
728 | ||
729 | for (i = 0; i < rdg->n_vertices; i++) | |
730 | VEC_safe_push (int, heap, all_components[rdg->vertices[i].component], i); | |
731 | ||
ac47786e | 732 | FOR_EACH_VEC_ELT (int, starting_vertices, i, v) |
dea61d92 SP |
733 | { |
734 | int c = rdg->vertices[v].component; | |
735 | ||
fcaa4ca4 | 736 | if (bitmap_set_bit (saved_components, c)) |
dea61d92 SP |
737 | { |
738 | rdgc x = XCNEW (struct rdg_component); | |
739 | x->num = c; | |
740 | x->vertices = all_components[c]; | |
741 | ||
742 | VEC_safe_push (rdgc, heap, *components, x); | |
dea61d92 SP |
743 | } |
744 | } | |
745 | ||
746 | for (i = 0; i < n_components; i++) | |
747 | if (!bitmap_bit_p (saved_components, i)) | |
748 | VEC_free (int, heap, all_components[i]); | |
749 | ||
750 | free (all_components); | |
751 | BITMAP_FREE (saved_components); | |
752 | } | |
753 | ||
cfee318d SP |
754 | /* Returns true when it is possible to generate a builtin pattern for |
755 | the PARTITION of RDG. For the moment we detect only the memset | |
756 | zero pattern. */ | |
757 | ||
758 | static bool | |
759 | can_generate_builtin (struct graph *rdg, bitmap partition) | |
760 | { | |
761 | unsigned i; | |
762 | bitmap_iterator bi; | |
763 | int nb_reads = 0; | |
764 | int nb_writes = 0; | |
765 | int stores_zero = 0; | |
766 | ||
767 | EXECUTE_IF_SET_IN_BITMAP (partition, 0, i, bi) | |
768 | if (RDG_MEM_READS_STMT (rdg, i)) | |
769 | nb_reads++; | |
770 | else if (RDG_MEM_WRITE_STMT (rdg, i)) | |
771 | { | |
772 | nb_writes++; | |
773 | if (stmt_with_adjacent_zero_store_dr_p (RDG_STMT (rdg, i))) | |
774 | stores_zero++; | |
775 | } | |
776 | ||
777 | return stores_zero == 1 && nb_writes == 1 && nb_reads == 0; | |
778 | } | |
779 | ||
780 | /* Returns true when PARTITION1 and PARTITION2 have similar memory | |
781 | accesses in RDG. */ | |
782 | ||
783 | static bool | |
784 | similar_memory_accesses (struct graph *rdg, bitmap partition1, | |
785 | bitmap partition2) | |
786 | { | |
787 | unsigned i, j; | |
788 | bitmap_iterator bi, bj; | |
789 | ||
790 | EXECUTE_IF_SET_IN_BITMAP (partition1, 0, i, bi) | |
791 | if (RDG_MEM_WRITE_STMT (rdg, i) | |
792 | || RDG_MEM_READS_STMT (rdg, i)) | |
793 | EXECUTE_IF_SET_IN_BITMAP (partition2, 0, j, bj) | |
794 | if (RDG_MEM_WRITE_STMT (rdg, j) | |
795 | || RDG_MEM_READS_STMT (rdg, j)) | |
796 | if (rdg_has_similar_memory_accesses (rdg, i, j)) | |
797 | return true; | |
798 | ||
799 | return false; | |
800 | } | |
801 | ||
802 | /* Fuse all the partitions from PARTITIONS that contain similar memory | |
803 | references, i.e., we're taking care of cache locality. This | |
804 | function does not fuse those partitions that contain patterns that | |
805 | can be code generated with builtins. */ | |
806 | ||
807 | static void | |
808 | fuse_partitions_with_similar_memory_accesses (struct graph *rdg, | |
809 | VEC (bitmap, heap) **partitions) | |
810 | { | |
811 | int p1, p2; | |
812 | bitmap partition1, partition2; | |
813 | ||
814 | FOR_EACH_VEC_ELT (bitmap, *partitions, p1, partition1) | |
815 | if (!can_generate_builtin (rdg, partition1)) | |
816 | FOR_EACH_VEC_ELT (bitmap, *partitions, p2, partition2) | |
817 | if (p1 != p2 | |
818 | && !can_generate_builtin (rdg, partition2) | |
819 | && similar_memory_accesses (rdg, partition1, partition2)) | |
820 | { | |
821 | bitmap_ior_into (partition1, partition2); | |
822 | VEC_ordered_remove (bitmap, *partitions, p2); | |
823 | p2--; | |
824 | } | |
825 | } | |
826 | ||
ab221087 SP |
827 | /* Returns true when DEF is an SSA_NAME defined in LOOP and used after |
828 | the LOOP. */ | |
829 | ||
830 | static bool | |
831 | ssa_name_has_uses_outside_loop_p (tree def, loop_p loop) | |
832 | { | |
833 | imm_use_iterator imm_iter; | |
834 | use_operand_p use_p; | |
835 | ||
836 | FOR_EACH_IMM_USE_FAST (use_p, imm_iter, def) | |
837 | if (loop != loop_containing_stmt (USE_STMT (use_p))) | |
838 | return true; | |
839 | ||
840 | return false; | |
841 | } | |
842 | ||
843 | /* Returns true when STMT defines a scalar variable used after the | |
844 | loop. */ | |
845 | ||
846 | static bool | |
847 | stmt_has_scalar_dependences_outside_loop (gimple stmt) | |
848 | { | |
849 | tree name; | |
850 | ||
851 | switch (gimple_code (stmt)) | |
852 | { | |
853 | case GIMPLE_ASSIGN: | |
854 | name = gimple_assign_lhs (stmt); | |
855 | break; | |
856 | ||
857 | case GIMPLE_PHI: | |
858 | name = gimple_phi_result (stmt); | |
859 | break; | |
860 | ||
861 | default: | |
862 | return false; | |
863 | } | |
864 | ||
865 | return TREE_CODE (name) == SSA_NAME | |
866 | && ssa_name_has_uses_outside_loop_p (name, loop_containing_stmt (stmt)); | |
867 | } | |
868 | ||
869 | /* Returns true when STMT will be code generated in a partition of RDG | |
870 | different than PART and that will not be code generated as a | |
871 | builtin. */ | |
872 | ||
873 | static bool | |
874 | stmt_generated_in_another_partition (struct graph *rdg, gimple stmt, int part, | |
875 | VEC (bitmap, heap) *partitions) | |
876 | { | |
877 | int p; | |
878 | bitmap pp; | |
879 | unsigned i; | |
880 | bitmap_iterator bi; | |
881 | ||
882 | FOR_EACH_VEC_ELT (bitmap, partitions, p, pp) | |
883 | if (p != part | |
884 | && !can_generate_builtin (rdg, pp)) | |
885 | EXECUTE_IF_SET_IN_BITMAP (pp, 0, i, bi) | |
886 | if (stmt == RDG_STMT (rdg, i)) | |
887 | return true; | |
888 | ||
889 | return false; | |
890 | } | |
891 | ||
892 | /* For each partition in PARTITIONS that will be code generated using | |
893 | a builtin, add its scalar computations used after the loop to | |
894 | PARTITION. */ | |
895 | ||
896 | static void | |
897 | add_scalar_computations_to_partition (struct graph *rdg, | |
898 | VEC (bitmap, heap) *partitions, | |
899 | bitmap partition) | |
900 | { | |
901 | int p; | |
902 | bitmap pp; | |
903 | unsigned i; | |
904 | bitmap_iterator bi; | |
905 | bitmap l = BITMAP_ALLOC (NULL); | |
906 | bitmap pr = BITMAP_ALLOC (NULL); | |
907 | bool f = false; | |
908 | ||
909 | FOR_EACH_VEC_ELT (bitmap, partitions, p, pp) | |
910 | if (can_generate_builtin (rdg, pp)) | |
911 | EXECUTE_IF_SET_IN_BITMAP (pp, 0, i, bi) | |
912 | if (stmt_has_scalar_dependences_outside_loop (RDG_STMT (rdg, i)) | |
913 | && !stmt_generated_in_another_partition (rdg, RDG_STMT (rdg, i), p, | |
914 | partitions)) | |
915 | rdg_flag_vertex_and_dependent (rdg, i, partition, l, pr, &f); | |
916 | ||
917 | rdg_flag_loop_exits (rdg, l, partition, pr, &f); | |
918 | ||
919 | BITMAP_FREE (pr); | |
920 | BITMAP_FREE (l); | |
921 | } | |
922 | ||
dea61d92 SP |
923 | /* Aggregate several components into a useful partition that is |
924 | registered in the PARTITIONS vector. Partitions will be | |
925 | distributed in different loops. */ | |
926 | ||
927 | static void | |
928 | rdg_build_partitions (struct graph *rdg, VEC (rdgc, heap) *components, | |
929 | VEC (int, heap) **other_stores, | |
930 | VEC (bitmap, heap) **partitions, bitmap processed) | |
931 | { | |
932 | int i; | |
933 | rdgc x; | |
934 | bitmap partition = BITMAP_ALLOC (NULL); | |
935 | ||
ac47786e | 936 | FOR_EACH_VEC_ELT (rdgc, components, i, x) |
dea61d92 SP |
937 | { |
938 | bitmap np; | |
939 | bool part_has_writes = false; | |
940 | int v = VEC_index (int, x->vertices, 0); | |
b8698a0f | 941 | |
dea61d92 SP |
942 | if (bitmap_bit_p (processed, v)) |
943 | continue; | |
b8698a0f | 944 | |
cfee318d | 945 | np = build_rdg_partition_for_component (rdg, x, &part_has_writes); |
dea61d92 SP |
946 | bitmap_ior_into (partition, np); |
947 | bitmap_ior_into (processed, np); | |
948 | BITMAP_FREE (np); | |
949 | ||
950 | if (part_has_writes) | |
951 | { | |
952 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
953 | { | |
954 | fprintf (dump_file, "ldist useful partition:\n"); | |
955 | dump_bitmap (dump_file, partition); | |
956 | } | |
957 | ||
958 | VEC_safe_push (bitmap, heap, *partitions, partition); | |
959 | partition = BITMAP_ALLOC (NULL); | |
960 | } | |
961 | } | |
962 | ||
963 | /* Add the nodes from the RDG that were not marked as processed, and | |
964 | that are used outside the current loop. These are scalar | |
965 | computations that are not yet part of previous partitions. */ | |
966 | for (i = 0; i < rdg->n_vertices; i++) | |
967 | if (!bitmap_bit_p (processed, i) | |
968 | && rdg_defs_used_in_other_loops_p (rdg, i)) | |
969 | VEC_safe_push (int, heap, *other_stores, i); | |
970 | ||
971 | /* If there are still statements left in the OTHER_STORES array, | |
972 | create other components and partitions with these stores and | |
973 | their dependences. */ | |
974 | if (VEC_length (int, *other_stores) > 0) | |
975 | { | |
976 | VEC (rdgc, heap) *comps = VEC_alloc (rdgc, heap, 3); | |
977 | VEC (int, heap) *foo = VEC_alloc (int, heap, 3); | |
978 | ||
979 | rdg_build_components (rdg, *other_stores, &comps); | |
980 | rdg_build_partitions (rdg, comps, &foo, partitions, processed); | |
981 | ||
982 | VEC_free (int, heap, foo); | |
983 | free_rdg_components (comps); | |
984 | } | |
985 | ||
ab221087 SP |
986 | add_scalar_computations_to_partition (rdg, *partitions, partition); |
987 | ||
dea61d92 SP |
988 | /* If there is something left in the last partition, save it. */ |
989 | if (bitmap_count_bits (partition) > 0) | |
990 | VEC_safe_push (bitmap, heap, *partitions, partition); | |
991 | else | |
992 | BITMAP_FREE (partition); | |
cfee318d SP |
993 | |
994 | fuse_partitions_with_similar_memory_accesses (rdg, partitions); | |
dea61d92 SP |
995 | } |
996 | ||
997 | /* Dump to FILE the PARTITIONS. */ | |
998 | ||
999 | static void | |
1000 | dump_rdg_partitions (FILE *file, VEC (bitmap, heap) *partitions) | |
1001 | { | |
1002 | int i; | |
1003 | bitmap partition; | |
1004 | ||
ac47786e | 1005 | FOR_EACH_VEC_ELT (bitmap, partitions, i, partition) |
dea61d92 SP |
1006 | debug_bitmap_file (file, partition); |
1007 | } | |
1008 | ||
1009 | /* Debug PARTITIONS. */ | |
1010 | extern void debug_rdg_partitions (VEC (bitmap, heap) *); | |
1011 | ||
24e47c76 | 1012 | DEBUG_FUNCTION void |
dea61d92 SP |
1013 | debug_rdg_partitions (VEC (bitmap, heap) *partitions) |
1014 | { | |
1015 | dump_rdg_partitions (stderr, partitions); | |
1016 | } | |
1017 | ||
2b8aee8e SP |
1018 | /* Returns the number of read and write operations in the RDG. */ |
1019 | ||
1020 | static int | |
1021 | number_of_rw_in_rdg (struct graph *rdg) | |
1022 | { | |
1023 | int i, res = 0; | |
1024 | ||
1025 | for (i = 0; i < rdg->n_vertices; i++) | |
1026 | { | |
1027 | if (RDG_MEM_WRITE_STMT (rdg, i)) | |
1028 | ++res; | |
1029 | ||
1030 | if (RDG_MEM_READS_STMT (rdg, i)) | |
1031 | ++res; | |
1032 | } | |
1033 | ||
1034 | return res; | |
1035 | } | |
1036 | ||
1037 | /* Returns the number of read and write operations in a PARTITION of | |
1038 | the RDG. */ | |
1039 | ||
1040 | static int | |
1041 | number_of_rw_in_partition (struct graph *rdg, bitmap partition) | |
1042 | { | |
1043 | int res = 0; | |
1044 | unsigned i; | |
1045 | bitmap_iterator ii; | |
1046 | ||
1047 | EXECUTE_IF_SET_IN_BITMAP (partition, 0, i, ii) | |
1048 | { | |
1049 | if (RDG_MEM_WRITE_STMT (rdg, i)) | |
1050 | ++res; | |
1051 | ||
1052 | if (RDG_MEM_READS_STMT (rdg, i)) | |
1053 | ++res; | |
1054 | } | |
1055 | ||
1056 | return res; | |
1057 | } | |
1058 | ||
1059 | /* Returns true when one of the PARTITIONS contains all the read or | |
1060 | write operations of RDG. */ | |
1061 | ||
1062 | static bool | |
1063 | partition_contains_all_rw (struct graph *rdg, VEC (bitmap, heap) *partitions) | |
1064 | { | |
1065 | int i; | |
1066 | bitmap partition; | |
1067 | int nrw = number_of_rw_in_rdg (rdg); | |
1068 | ||
ac47786e | 1069 | FOR_EACH_VEC_ELT (bitmap, partitions, i, partition) |
2b8aee8e SP |
1070 | if (nrw == number_of_rw_in_partition (rdg, partition)) |
1071 | return true; | |
1072 | ||
1073 | return false; | |
1074 | } | |
1075 | ||
dea61d92 SP |
1076 | /* Generate code from STARTING_VERTICES in RDG. Returns the number of |
1077 | distributed loops. */ | |
1078 | ||
1079 | static int | |
1080 | ldist_gen (struct loop *loop, struct graph *rdg, | |
1081 | VEC (int, heap) *starting_vertices) | |
1082 | { | |
1083 | int i, nbp; | |
1084 | VEC (rdgc, heap) *components = VEC_alloc (rdgc, heap, 3); | |
1085 | VEC (bitmap, heap) *partitions = VEC_alloc (bitmap, heap, 3); | |
1086 | VEC (int, heap) *other_stores = VEC_alloc (int, heap, 3); | |
1087 | bitmap partition, processed = BITMAP_ALLOC (NULL); | |
1088 | ||
1089 | remaining_stmts = BITMAP_ALLOC (NULL); | |
1090 | upstream_mem_writes = BITMAP_ALLOC (NULL); | |
1091 | ||
1092 | for (i = 0; i < rdg->n_vertices; i++) | |
1093 | { | |
1094 | bitmap_set_bit (remaining_stmts, i); | |
1095 | ||
1096 | /* Save in OTHER_STORES all the memory writes that are not in | |
1097 | STARTING_VERTICES. */ | |
1098 | if (RDG_MEM_WRITE_STMT (rdg, i)) | |
1099 | { | |
1100 | int v; | |
1101 | unsigned j; | |
1102 | bool found = false; | |
1103 | ||
ac47786e | 1104 | FOR_EACH_VEC_ELT (int, starting_vertices, j, v) |
dea61d92 SP |
1105 | if (i == v) |
1106 | { | |
1107 | found = true; | |
1108 | break; | |
1109 | } | |
1110 | ||
1111 | if (!found) | |
1112 | VEC_safe_push (int, heap, other_stores, i); | |
1113 | } | |
1114 | } | |
1115 | ||
1116 | mark_nodes_having_upstream_mem_writes (rdg); | |
1117 | rdg_build_components (rdg, starting_vertices, &components); | |
1118 | rdg_build_partitions (rdg, components, &other_stores, &partitions, | |
1119 | processed); | |
1120 | BITMAP_FREE (processed); | |
1121 | nbp = VEC_length (bitmap, partitions); | |
1122 | ||
2b8aee8e SP |
1123 | if (nbp <= 1 |
1124 | || partition_contains_all_rw (rdg, partitions)) | |
dea61d92 SP |
1125 | goto ldist_done; |
1126 | ||
1127 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1128 | dump_rdg_partitions (dump_file, partitions); | |
1129 | ||
ac47786e | 1130 | FOR_EACH_VEC_ELT (bitmap, partitions, i, partition) |
dea61d92 SP |
1131 | if (!generate_code_for_partition (loop, partition, i < nbp - 1)) |
1132 | goto ldist_done; | |
1133 | ||
1134 | rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa); | |
1135 | update_ssa (TODO_update_ssa_only_virtuals | TODO_update_ssa); | |
1136 | ||
1137 | ldist_done: | |
1138 | ||
1139 | BITMAP_FREE (remaining_stmts); | |
1140 | BITMAP_FREE (upstream_mem_writes); | |
1141 | ||
ac47786e | 1142 | FOR_EACH_VEC_ELT (bitmap, partitions, i, partition) |
dea61d92 SP |
1143 | BITMAP_FREE (partition); |
1144 | ||
1145 | VEC_free (int, heap, other_stores); | |
1146 | VEC_free (bitmap, heap, partitions); | |
1147 | free_rdg_components (components); | |
1148 | return nbp; | |
1149 | } | |
1150 | ||
1151 | /* Distributes the code from LOOP in such a way that producer | |
1152 | statements are placed before consumer statements. When STMTS is | |
1153 | NULL, performs the maximal distribution, if STMTS is not NULL, | |
1154 | tries to separate only these statements from the LOOP's body. | |
1155 | Returns the number of distributed loops. */ | |
1156 | ||
1157 | static int | |
726a989a | 1158 | distribute_loop (struct loop *loop, VEC (gimple, heap) *stmts) |
dea61d92 | 1159 | { |
e96d7dd7 | 1160 | int res = 0; |
dea61d92 | 1161 | struct graph *rdg; |
726a989a | 1162 | gimple s; |
dea61d92 SP |
1163 | unsigned i; |
1164 | VEC (int, heap) *vertices; | |
01be8516 SP |
1165 | VEC (ddr_p, heap) *dependence_relations; |
1166 | VEC (data_reference_p, heap) *datarefs; | |
1167 | VEC (loop_p, heap) *loop_nest; | |
dea61d92 SP |
1168 | |
1169 | if (loop->num_nodes > 2) | |
1170 | { | |
1171 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1172 | fprintf (dump_file, | |
1173 | "FIXME: Loop %d not distributed: it has more than two basic blocks.\n", | |
1174 | loop->num); | |
1175 | ||
1176 | return res; | |
1177 | } | |
1178 | ||
01be8516 SP |
1179 | datarefs = VEC_alloc (data_reference_p, heap, 10); |
1180 | dependence_relations = VEC_alloc (ddr_p, heap, 100); | |
1181 | loop_nest = VEC_alloc (loop_p, heap, 3); | |
1182 | rdg = build_rdg (loop, &loop_nest, &dependence_relations, &datarefs); | |
dea61d92 SP |
1183 | |
1184 | if (!rdg) | |
1185 | { | |
1186 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1187 | fprintf (dump_file, | |
1188 | "FIXME: Loop %d not distributed: failed to build the RDG.\n", | |
1189 | loop->num); | |
1190 | ||
01be8516 SP |
1191 | free_dependence_relations (dependence_relations); |
1192 | free_data_refs (datarefs); | |
1193 | VEC_free (loop_p, heap, loop_nest); | |
dea61d92 SP |
1194 | return res; |
1195 | } | |
1196 | ||
1197 | vertices = VEC_alloc (int, heap, 3); | |
1198 | ||
1199 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1200 | dump_rdg (dump_file, rdg); | |
1201 | ||
ac47786e | 1202 | FOR_EACH_VEC_ELT (gimple, stmts, i, s) |
dea61d92 SP |
1203 | { |
1204 | int v = rdg_vertex_for_stmt (rdg, s); | |
1205 | ||
1206 | if (v >= 0) | |
1207 | { | |
1208 | VEC_safe_push (int, heap, vertices, v); | |
1209 | ||
1210 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1211 | fprintf (dump_file, | |
1212 | "ldist asked to generate code for vertex %d\n", v); | |
1213 | } | |
1214 | } | |
1215 | ||
1216 | res = ldist_gen (loop, rdg, vertices); | |
1217 | VEC_free (int, heap, vertices); | |
1218 | free_rdg (rdg); | |
01be8516 SP |
1219 | free_dependence_relations (dependence_relations); |
1220 | free_data_refs (datarefs); | |
1221 | VEC_free (loop_p, heap, loop_nest); | |
dea61d92 SP |
1222 | return res; |
1223 | } | |
1224 | ||
1225 | /* Distribute all loops in the current function. */ | |
1226 | ||
1227 | static unsigned int | |
1228 | tree_loop_distribution (void) | |
1229 | { | |
1230 | struct loop *loop; | |
1231 | loop_iterator li; | |
1232 | int nb_generated_loops = 0; | |
1233 | ||
1234 | FOR_EACH_LOOP (li, loop, 0) | |
1235 | { | |
a3357f7d | 1236 | VEC (gimple, heap) *work_list = NULL; |
0e20c89f | 1237 | int num = loop->num; |
a3357f7d RG |
1238 | |
1239 | /* If the loop doesn't have a single exit we will fail anyway, | |
1240 | so do that early. */ | |
1241 | if (!single_exit (loop)) | |
1242 | continue; | |
dea61d92 | 1243 | |
20769d5e SP |
1244 | /* If both flag_tree_loop_distribute_patterns and |
1245 | flag_tree_loop_distribution are set, then only | |
1246 | distribute_patterns is executed. */ | |
1247 | if (flag_tree_loop_distribute_patterns) | |
1248 | { | |
1249 | /* With the following working list, we're asking | |
1250 | distribute_loop to separate from the rest of the loop the | |
1251 | stores of the form "A[i] = 0". */ | |
1252 | stores_zero_from_loop (loop, &work_list); | |
1253 | ||
1254 | /* Do nothing if there are no patterns to be distributed. */ | |
1255 | if (VEC_length (gimple, work_list) > 0) | |
1256 | nb_generated_loops = distribute_loop (loop, work_list); | |
1257 | } | |
1258 | else if (flag_tree_loop_distribution) | |
1259 | { | |
1260 | /* With the following working list, we're asking | |
1261 | distribute_loop to separate the stores of the loop: when | |
1262 | dependences allow, it will end on having one store per | |
1263 | loop. */ | |
1264 | stores_from_loop (loop, &work_list); | |
1265 | ||
1266 | /* A simple heuristic for cache locality is to not split | |
1267 | stores to the same array. Without this call, an unrolled | |
1268 | loop would be split into as many loops as unroll factor, | |
1269 | each loop storing in the same array. */ | |
1270 | remove_similar_memory_refs (&work_list); | |
1271 | ||
1272 | nb_generated_loops = distribute_loop (loop, work_list); | |
1273 | } | |
dea61d92 SP |
1274 | |
1275 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1276 | { | |
1277 | if (nb_generated_loops > 1) | |
1278 | fprintf (dump_file, "Loop %d distributed: split to %d loops.\n", | |
0e20c89f | 1279 | num, nb_generated_loops); |
dea61d92 | 1280 | else |
0e20c89f | 1281 | fprintf (dump_file, "Loop %d is the same.\n", num); |
dea61d92 SP |
1282 | } |
1283 | ||
1284 | verify_loop_structure (); | |
1285 | ||
726a989a | 1286 | VEC_free (gimple, heap, work_list); |
dea61d92 SP |
1287 | } |
1288 | ||
5006671f | 1289 | return 0; |
dea61d92 SP |
1290 | } |
1291 | ||
1292 | static bool | |
1293 | gate_tree_loop_distribution (void) | |
1294 | { | |
20769d5e SP |
1295 | return flag_tree_loop_distribution |
1296 | || flag_tree_loop_distribute_patterns; | |
dea61d92 SP |
1297 | } |
1298 | ||
8ddbbcae | 1299 | struct gimple_opt_pass pass_loop_distribution = |
dea61d92 | 1300 | { |
8ddbbcae JH |
1301 | { |
1302 | GIMPLE_PASS, | |
dea61d92 SP |
1303 | "ldist", /* name */ |
1304 | gate_tree_loop_distribution, /* gate */ | |
1305 | tree_loop_distribution, /* execute */ | |
1306 | NULL, /* sub */ | |
1307 | NULL, /* next */ | |
1308 | 0, /* static_pass_number */ | |
1309 | TV_TREE_LOOP_DISTRIBUTION, /* tv_id */ | |
1310 | PROP_cfg | PROP_ssa, /* properties_required */ | |
1311 | 0, /* properties_provided */ | |
1312 | 0, /* properties_destroyed */ | |
1313 | 0, /* todo_flags_start */ | |
22c5fa5f | 1314 | 0 /* todo_flags_finish */ |
8ddbbcae | 1315 | } |
dea61d92 | 1316 | }; |