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6de9cd9a DN |
1 | /* Convert a program in SSA form into Normal form. |
2 | Copyright (C) 2004 Free Software Foundation, Inc. | |
3 | Contributed by Andrew Macleod <amacleod@redhat.com> | |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 2, or (at your option) | |
10 | any later version. | |
11 | ||
12 | GCC is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GCC; see the file COPYING. If not, write to | |
19 | the Free Software Foundation, 59 Temple Place - Suite 330, | |
20 | Boston, MA 02111-1307, USA. */ | |
21 | ||
22 | #include "config.h" | |
23 | #include "system.h" | |
24 | #include "coretypes.h" | |
25 | #include "tm.h" | |
26 | #include "tree.h" | |
27 | #include "flags.h" | |
28 | #include "rtl.h" | |
29 | #include "tm_p.h" | |
30 | #include "ggc.h" | |
31 | #include "langhooks.h" | |
32 | #include "hard-reg-set.h" | |
33 | #include "basic-block.h" | |
34 | #include "output.h" | |
35 | #include "errors.h" | |
36 | #include "expr.h" | |
37 | #include "function.h" | |
38 | #include "diagnostic.h" | |
39 | #include "bitmap.h" | |
40 | #include "tree-flow.h" | |
eadf906f | 41 | #include "tree-gimple.h" |
6de9cd9a DN |
42 | #include "tree-inline.h" |
43 | #include "varray.h" | |
44 | #include "timevar.h" | |
6de9cd9a DN |
45 | #include "hashtab.h" |
46 | #include "tree-dump.h" | |
47 | #include "tree-ssa-live.h" | |
48 | #include "tree-pass.h" | |
49 | ||
56b043c8 JL |
50 | /* Flags to pass to remove_ssa_form. */ |
51 | ||
52 | #define SSANORM_PERFORM_TER 0x1 | |
53 | #define SSANORM_COMBINE_TEMPS 0x2 | |
54 | #define SSANORM_REMOVE_ALL_PHIS 0x4 | |
55 | #define SSANORM_COALESCE_PARTITIONS 0x8 | |
56 | #define SSANORM_USE_COALESCE_LIST 0x10 | |
57 | ||
6de9cd9a DN |
58 | /* Used to hold all the components required to do SSA PHI elimination. |
59 | The node and pred/succ list is a simple linear list of nodes and | |
60 | edges represented as pairs of nodes. | |
61 | ||
62 | The predecessor and successor list: Nodes are entered in pairs, where | |
63 | [0] ->PRED, [1]->SUCC. All the even indexes in the array represent | |
64 | predecessors, all the odd elements are successors. | |
65 | ||
66 | Rationale: | |
67 | When implemented as bitmaps, very large programs SSA->Normal times were | |
68 | being dominated by clearing the interference graph. | |
69 | ||
70 | Typically this list of edges is extremely small since it only includes | |
71 | PHI results and uses from a single edge which have not coalesced with | |
72 | each other. This means that no virtual PHI nodes are included, and | |
73 | empirical evidence suggests that the number of edges rarely exceed | |
74 | 3, and in a bootstrap of GCC, the maximum size encountered was 7. | |
75 | This also limits the number of possible nodes that are involved to | |
76 | rarely more than 6, and in the bootstrap of gcc, the maximum number | |
77 | of nodes encountered was 12. */ | |
78 | ||
79 | typedef struct _elim_graph { | |
80 | /* Size of the elimination vectors. */ | |
81 | int size; | |
82 | ||
83 | /* List of nodes in the elimination graph. */ | |
84 | varray_type nodes; | |
85 | ||
9cf737f8 | 86 | /* The predecessor and successor edge list. */ |
6de9cd9a DN |
87 | varray_type edge_list; |
88 | ||
89 | /* Visited vector. */ | |
90 | sbitmap visited; | |
91 | ||
92 | /* Stack for visited nodes. */ | |
93 | varray_type stack; | |
94 | ||
95 | /* The variable partition map. */ | |
96 | var_map map; | |
97 | ||
98 | /* Edge being eliminated by this graph. */ | |
99 | edge e; | |
100 | ||
101 | /* List of constant copies to emit. These are pushed on in pairs. */ | |
102 | varray_type const_copies; | |
103 | } *elim_graph; | |
104 | ||
105 | ||
106 | /* Local functions. */ | |
107 | static tree create_temp (tree); | |
108 | static void insert_copy_on_edge (edge, tree, tree); | |
109 | static elim_graph new_elim_graph (int); | |
110 | static inline void delete_elim_graph (elim_graph); | |
111 | static inline void clear_elim_graph (elim_graph); | |
112 | static inline int elim_graph_size (elim_graph); | |
113 | static inline void elim_graph_add_node (elim_graph, tree); | |
114 | static inline void elim_graph_add_edge (elim_graph, int, int); | |
115 | static inline int elim_graph_remove_succ_edge (elim_graph, int); | |
116 | ||
117 | static inline void eliminate_name (elim_graph, tree); | |
118 | static void eliminate_build (elim_graph, basic_block, int); | |
119 | static void elim_forward (elim_graph, int); | |
120 | static int elim_unvisited_predecessor (elim_graph, int); | |
121 | static void elim_backward (elim_graph, int); | |
122 | static void elim_create (elim_graph, int); | |
123 | static void eliminate_phi (edge, int, elim_graph); | |
124 | static tree_live_info_p coalesce_ssa_name (var_map, int); | |
125 | static void assign_vars (var_map); | |
d00ad49b AM |
126 | static bool replace_use_variable (var_map, use_operand_p, tree *); |
127 | static bool replace_def_variable (var_map, def_operand_p, tree *); | |
6de9cd9a DN |
128 | static void eliminate_virtual_phis (void); |
129 | static void coalesce_abnormal_edges (var_map, conflict_graph, root_var_p); | |
130 | static void print_exprs (FILE *, const char *, tree, const char *, tree, | |
131 | const char *); | |
132 | static void print_exprs_edge (FILE *, edge, const char *, tree, const char *, | |
133 | tree); | |
134 | ||
135 | ||
136 | /* Create a temporary variable based on the type of variable T. Use T's name | |
137 | as the prefix. */ | |
138 | ||
139 | static tree | |
140 | create_temp (tree t) | |
141 | { | |
142 | tree tmp; | |
143 | const char *name = NULL; | |
144 | tree type; | |
145 | ||
146 | if (TREE_CODE (t) == SSA_NAME) | |
147 | t = SSA_NAME_VAR (t); | |
1e128c5f GB |
148 | |
149 | gcc_assert (TREE_CODE (t) == VAR_DECL || TREE_CODE (t) == PARM_DECL); | |
6de9cd9a DN |
150 | |
151 | type = TREE_TYPE (t); | |
152 | tmp = DECL_NAME (t); | |
153 | if (tmp) | |
154 | name = IDENTIFIER_POINTER (tmp); | |
155 | ||
156 | if (name == NULL) | |
157 | name = "temp"; | |
158 | tmp = create_tmp_var (type, name); | |
159 | DECL_ARTIFICIAL (tmp) = DECL_ARTIFICIAL (t); | |
160 | add_referenced_tmp_var (tmp); | |
161 | ||
162 | /* add_referenced_tmp_var will create the annotation and set up some | |
163 | of the flags in the annotation. However, some flags we need to | |
164 | inherit from our original variable. */ | |
165 | var_ann (tmp)->type_mem_tag = var_ann (t)->type_mem_tag; | |
166 | if (is_call_clobbered (t)) | |
167 | mark_call_clobbered (tmp); | |
168 | ||
169 | return tmp; | |
170 | } | |
171 | ||
172 | ||
173 | /* This helper function fill insert a copy from a constant or variable SRC to | |
174 | variable DEST on edge E. */ | |
175 | ||
176 | static void | |
177 | insert_copy_on_edge (edge e, tree dest, tree src) | |
178 | { | |
179 | tree copy; | |
180 | ||
181 | copy = build (MODIFY_EXPR, TREE_TYPE (dest), dest, src); | |
182 | set_is_used (dest); | |
183 | ||
184 | if (TREE_CODE (src) == ADDR_EXPR) | |
185 | src = TREE_OPERAND (src, 0); | |
186 | if (TREE_CODE (src) == VAR_DECL || TREE_CODE (src) == PARM_DECL) | |
187 | set_is_used (src); | |
188 | ||
189 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
190 | { | |
191 | fprintf (dump_file, | |
192 | "Inserting a copy on edge BB%d->BB%d :", | |
193 | e->src->index, | |
194 | e->dest->index); | |
195 | print_generic_expr (dump_file, copy, dump_flags); | |
196 | fprintf (dump_file, "\n"); | |
197 | } | |
198 | ||
199 | bsi_insert_on_edge (e, copy); | |
200 | } | |
201 | ||
202 | ||
203 | /* Create an elimination graph with SIZE nodes and associated data | |
204 | structures. */ | |
205 | ||
206 | static elim_graph | |
207 | new_elim_graph (int size) | |
208 | { | |
209 | elim_graph g = (elim_graph) xmalloc (sizeof (struct _elim_graph)); | |
210 | ||
211 | VARRAY_TREE_INIT (g->nodes, 30, "Elimination Node List"); | |
212 | VARRAY_TREE_INIT (g->const_copies, 20, "Elimination Constant Copies"); | |
213 | VARRAY_INT_INIT (g->edge_list, 20, "Elimination Edge List"); | |
214 | VARRAY_INT_INIT (g->stack, 30, " Elimination Stack"); | |
215 | ||
216 | g->visited = sbitmap_alloc (size); | |
217 | ||
218 | return g; | |
219 | } | |
220 | ||
221 | ||
222 | /* Empty elimination graph G. */ | |
223 | ||
224 | static inline void | |
225 | clear_elim_graph (elim_graph g) | |
226 | { | |
227 | VARRAY_POP_ALL (g->nodes); | |
228 | VARRAY_POP_ALL (g->edge_list); | |
229 | } | |
230 | ||
231 | ||
232 | /* Delete elimination graph G. */ | |
233 | ||
234 | static inline void | |
235 | delete_elim_graph (elim_graph g) | |
236 | { | |
237 | sbitmap_free (g->visited); | |
238 | free (g); | |
239 | } | |
240 | ||
241 | ||
242 | /* Return the number of nodes in graph G. */ | |
243 | ||
244 | static inline int | |
245 | elim_graph_size (elim_graph g) | |
246 | { | |
247 | return VARRAY_ACTIVE_SIZE (g->nodes); | |
248 | } | |
249 | ||
250 | ||
251 | /* Add NODE to graph G, if it doesn't exist already. */ | |
252 | ||
253 | static inline void | |
254 | elim_graph_add_node (elim_graph g, tree node) | |
255 | { | |
256 | int x; | |
257 | for (x = 0; x < elim_graph_size (g); x++) | |
258 | if (VARRAY_TREE (g->nodes, x) == node) | |
259 | return; | |
260 | VARRAY_PUSH_TREE (g->nodes, node); | |
261 | } | |
262 | ||
263 | ||
264 | /* Add the edge PRED->SUCC to graph G. */ | |
265 | ||
266 | static inline void | |
267 | elim_graph_add_edge (elim_graph g, int pred, int succ) | |
268 | { | |
269 | VARRAY_PUSH_INT (g->edge_list, pred); | |
270 | VARRAY_PUSH_INT (g->edge_list, succ); | |
271 | } | |
272 | ||
273 | ||
274 | /* Remove an edge from graph G for which NODE is the predecessor, and | |
275 | return the successor node. -1 is returned if there is no such edge. */ | |
276 | ||
277 | static inline int | |
278 | elim_graph_remove_succ_edge (elim_graph g, int node) | |
279 | { | |
280 | int y; | |
281 | unsigned x; | |
282 | for (x = 0; x < VARRAY_ACTIVE_SIZE (g->edge_list); x += 2) | |
283 | if (VARRAY_INT (g->edge_list, x) == node) | |
284 | { | |
285 | VARRAY_INT (g->edge_list, x) = -1; | |
286 | y = VARRAY_INT (g->edge_list, x + 1); | |
287 | VARRAY_INT (g->edge_list, x + 1) = -1; | |
288 | return y; | |
289 | } | |
290 | return -1; | |
291 | } | |
292 | ||
293 | ||
294 | /* Find all the nodes in GRAPH which are successors to NODE in the | |
295 | edge list. VAR will hold the partition number found. CODE is the | |
296 | code fragment executed for every node found. */ | |
297 | ||
298 | #define FOR_EACH_ELIM_GRAPH_SUCC(GRAPH, NODE, VAR, CODE) \ | |
299 | do { \ | |
300 | unsigned x_; \ | |
301 | int y_; \ | |
302 | for (x_ = 0; x_ < VARRAY_ACTIVE_SIZE ((GRAPH)->edge_list); x_ += 2) \ | |
303 | { \ | |
304 | y_ = VARRAY_INT ((GRAPH)->edge_list, x_); \ | |
305 | if (y_ != (NODE)) \ | |
306 | continue; \ | |
307 | (VAR) = VARRAY_INT ((GRAPH)->edge_list, x_ + 1); \ | |
308 | CODE; \ | |
309 | } \ | |
310 | } while (0) | |
311 | ||
312 | ||
313 | /* Find all the nodes which are predecessors of NODE in the edge list for | |
314 | GRAPH. VAR will hold the partition number found. CODE is the | |
315 | code fragment executed for every node found. */ | |
316 | ||
317 | #define FOR_EACH_ELIM_GRAPH_PRED(GRAPH, NODE, VAR, CODE) \ | |
318 | do { \ | |
319 | unsigned x_; \ | |
320 | int y_; \ | |
321 | for (x_ = 0; x_ < VARRAY_ACTIVE_SIZE ((GRAPH)->edge_list); x_ += 2) \ | |
322 | { \ | |
323 | y_ = VARRAY_INT ((GRAPH)->edge_list, x_ + 1); \ | |
324 | if (y_ != (NODE)) \ | |
325 | continue; \ | |
326 | (VAR) = VARRAY_INT ((GRAPH)->edge_list, x_); \ | |
327 | CODE; \ | |
328 | } \ | |
329 | } while (0) | |
330 | ||
331 | ||
332 | /* Add T to elimination graph G. */ | |
333 | ||
334 | static inline void | |
335 | eliminate_name (elim_graph g, tree T) | |
336 | { | |
337 | elim_graph_add_node (g, T); | |
338 | } | |
339 | ||
340 | ||
341 | /* Build elimination graph G for basic block BB on incoming PHI edge I. */ | |
342 | ||
343 | static void | |
344 | eliminate_build (elim_graph g, basic_block B, int i) | |
345 | { | |
346 | tree phi; | |
347 | tree T0, Ti; | |
348 | int p0, pi; | |
349 | ||
350 | clear_elim_graph (g); | |
351 | ||
17192884 | 352 | for (phi = phi_nodes (B); phi; phi = PHI_CHAIN (phi)) |
6de9cd9a DN |
353 | { |
354 | T0 = var_to_partition_to_var (g->map, PHI_RESULT (phi)); | |
355 | ||
356 | /* Ignore results which are not in partitions. */ | |
357 | if (T0 == NULL_TREE) | |
358 | continue; | |
359 | ||
360 | if (PHI_ARG_EDGE (phi, i) == g->e) | |
361 | Ti = PHI_ARG_DEF (phi, i); | |
362 | else | |
363 | { | |
364 | /* On rare occasions, a PHI node may not have the arguments | |
365 | in the same order as all of the other PHI nodes. If they don't | |
366 | match, find the appropriate index here. */ | |
367 | pi = phi_arg_from_edge (phi, g->e); | |
1e128c5f | 368 | gcc_assert (pi != -1); |
6de9cd9a DN |
369 | Ti = PHI_ARG_DEF (phi, pi); |
370 | } | |
371 | ||
372 | /* If this argument is a constant, or a SSA_NAME which is being | |
373 | left in SSA form, just queue a copy to be emitted on this | |
374 | edge. */ | |
375 | if (!phi_ssa_name_p (Ti) | |
376 | || (TREE_CODE (Ti) == SSA_NAME | |
377 | && var_to_partition (g->map, Ti) == NO_PARTITION)) | |
378 | { | |
379 | /* Save constant copies until all other copies have been emitted | |
380 | on this edge. */ | |
381 | VARRAY_PUSH_TREE (g->const_copies, T0); | |
382 | VARRAY_PUSH_TREE (g->const_copies, Ti); | |
383 | } | |
384 | else | |
385 | { | |
386 | Ti = var_to_partition_to_var (g->map, Ti); | |
387 | if (T0 != Ti) | |
388 | { | |
389 | eliminate_name (g, T0); | |
390 | eliminate_name (g, Ti); | |
391 | p0 = var_to_partition (g->map, T0); | |
392 | pi = var_to_partition (g->map, Ti); | |
393 | elim_graph_add_edge (g, p0, pi); | |
394 | } | |
395 | } | |
396 | } | |
397 | } | |
398 | ||
399 | ||
400 | /* Push successors of T onto the elimination stack for G. */ | |
401 | ||
402 | static void | |
403 | elim_forward (elim_graph g, int T) | |
404 | { | |
405 | int S; | |
406 | SET_BIT (g->visited, T); | |
407 | FOR_EACH_ELIM_GRAPH_SUCC (g, T, S, | |
408 | { | |
409 | if (!TEST_BIT (g->visited, S)) | |
410 | elim_forward (g, S); | |
411 | }); | |
412 | VARRAY_PUSH_INT (g->stack, T); | |
413 | } | |
414 | ||
415 | ||
416 | /* Return 1 if there unvisited predecessors of T in graph G. */ | |
417 | ||
418 | static int | |
419 | elim_unvisited_predecessor (elim_graph g, int T) | |
420 | { | |
421 | int P; | |
422 | FOR_EACH_ELIM_GRAPH_PRED (g, T, P, | |
423 | { | |
424 | if (!TEST_BIT (g->visited, P)) | |
425 | return 1; | |
426 | }); | |
427 | return 0; | |
428 | } | |
429 | ||
430 | /* Process predecessors first, and insert a copy. */ | |
431 | ||
432 | static void | |
433 | elim_backward (elim_graph g, int T) | |
434 | { | |
435 | int P; | |
436 | SET_BIT (g->visited, T); | |
437 | FOR_EACH_ELIM_GRAPH_PRED (g, T, P, | |
438 | { | |
439 | if (!TEST_BIT (g->visited, P)) | |
440 | { | |
441 | elim_backward (g, P); | |
442 | insert_copy_on_edge (g->e, | |
443 | partition_to_var (g->map, P), | |
444 | partition_to_var (g->map, T)); | |
445 | } | |
446 | }); | |
447 | } | |
448 | ||
449 | /* Insert required copies for T in graph G. Check for a strongly connected | |
450 | region, and create a temporary to break the cycle if one is found. */ | |
451 | ||
452 | static void | |
453 | elim_create (elim_graph g, int T) | |
454 | { | |
455 | tree U; | |
456 | int P, S; | |
457 | ||
458 | if (elim_unvisited_predecessor (g, T)) | |
459 | { | |
460 | U = create_temp (partition_to_var (g->map, T)); | |
461 | insert_copy_on_edge (g->e, U, partition_to_var (g->map, T)); | |
462 | FOR_EACH_ELIM_GRAPH_PRED (g, T, P, | |
463 | { | |
464 | if (!TEST_BIT (g->visited, P)) | |
465 | { | |
466 | elim_backward (g, P); | |
467 | insert_copy_on_edge (g->e, partition_to_var (g->map, P), U); | |
468 | } | |
469 | }); | |
470 | } | |
471 | else | |
472 | { | |
473 | S = elim_graph_remove_succ_edge (g, T); | |
474 | if (S != -1) | |
475 | { | |
476 | SET_BIT (g->visited, T); | |
477 | insert_copy_on_edge (g->e, | |
478 | partition_to_var (g->map, T), | |
479 | partition_to_var (g->map, S)); | |
480 | } | |
481 | } | |
482 | ||
483 | } | |
484 | ||
485 | /* Eliminate all the phi nodes on edge E in graph G. I is the usual PHI | |
486 | index that edge E's values are found on. */ | |
487 | ||
488 | static void | |
489 | eliminate_phi (edge e, int i, elim_graph g) | |
490 | { | |
491 | int num_nodes = 0; | |
492 | int x; | |
493 | basic_block B = e->dest; | |
494 | ||
1e128c5f GB |
495 | gcc_assert (i != -1); |
496 | gcc_assert (VARRAY_ACTIVE_SIZE (g->const_copies) == 0); | |
6de9cd9a DN |
497 | |
498 | /* Abnormal edges already have everything coalesced, or the coalescer | |
499 | would have aborted. */ | |
500 | if (e->flags & EDGE_ABNORMAL) | |
501 | return; | |
502 | ||
503 | num_nodes = num_var_partitions (g->map); | |
504 | g->e = e; | |
505 | ||
506 | eliminate_build (g, B, i); | |
507 | ||
508 | if (elim_graph_size (g) != 0) | |
509 | { | |
510 | sbitmap_zero (g->visited); | |
511 | VARRAY_POP_ALL (g->stack); | |
512 | ||
513 | for (x = 0; x < elim_graph_size (g); x++) | |
514 | { | |
515 | tree var = VARRAY_TREE (g->nodes, x); | |
516 | int p = var_to_partition (g->map, var); | |
517 | if (!TEST_BIT (g->visited, p)) | |
518 | elim_forward (g, p); | |
519 | } | |
520 | ||
521 | sbitmap_zero (g->visited); | |
522 | while (VARRAY_ACTIVE_SIZE (g->stack) > 0) | |
523 | { | |
524 | x = VARRAY_TOP_INT (g->stack); | |
525 | VARRAY_POP (g->stack); | |
526 | if (!TEST_BIT (g->visited, x)) | |
527 | elim_create (g, x); | |
528 | } | |
529 | } | |
530 | ||
531 | /* If there are any pending constant copies, issue them now. */ | |
532 | while (VARRAY_ACTIVE_SIZE (g->const_copies) > 0) | |
533 | { | |
534 | tree src, dest; | |
535 | src = VARRAY_TOP_TREE (g->const_copies); | |
536 | VARRAY_POP (g->const_copies); | |
537 | dest = VARRAY_TOP_TREE (g->const_copies); | |
538 | VARRAY_POP (g->const_copies); | |
539 | insert_copy_on_edge (e, dest, src); | |
540 | } | |
541 | } | |
542 | ||
543 | ||
544 | /* Shortcut routine to print messages to file F of the form: | |
545 | "STR1 EXPR1 STR2 EXPR2 STR3." */ | |
546 | ||
547 | static void | |
548 | print_exprs (FILE *f, const char *str1, tree expr1, const char *str2, | |
549 | tree expr2, const char *str3) | |
550 | { | |
551 | fprintf (f, "%s", str1); | |
552 | print_generic_expr (f, expr1, TDF_SLIM); | |
553 | fprintf (f, "%s", str2); | |
554 | print_generic_expr (f, expr2, TDF_SLIM); | |
555 | fprintf (f, "%s", str3); | |
556 | } | |
557 | ||
558 | ||
559 | /* Shortcut routine to print abnormal edge messages to file F of the form: | |
560 | "STR1 EXPR1 STR2 EXPR2 across edge E. */ | |
561 | ||
562 | static void | |
563 | print_exprs_edge (FILE *f, edge e, const char *str1, tree expr1, | |
564 | const char *str2, tree expr2) | |
565 | { | |
566 | print_exprs (f, str1, expr1, str2, expr2, " across an abnormal edge"); | |
567 | fprintf (f, " from BB%d->BB%d\n", e->src->index, | |
568 | e->dest->index); | |
569 | } | |
570 | ||
571 | ||
572 | /* Coalesce partitions in MAP which are live across abnormal edges in GRAPH. | |
573 | RV is the root variable groupings of the partitions in MAP. Since code | |
574 | cannot be inserted on these edges, failure to coalesce something across | |
575 | an abnormal edge is an error. */ | |
576 | ||
577 | static void | |
578 | coalesce_abnormal_edges (var_map map, conflict_graph graph, root_var_p rv) | |
579 | { | |
580 | basic_block bb; | |
581 | edge e; | |
582 | tree phi, var, tmp; | |
583 | int x, y; | |
628f6a4e | 584 | edge_iterator ei; |
6de9cd9a DN |
585 | |
586 | /* Code cannot be inserted on abnormal edges. Look for all abnormal | |
587 | edges, and coalesce any PHI results with their arguments across | |
588 | that edge. */ | |
589 | ||
590 | FOR_EACH_BB (bb) | |
628f6a4e | 591 | FOR_EACH_EDGE (e, ei, bb->succs) |
6de9cd9a | 592 | if (e->dest != EXIT_BLOCK_PTR && e->flags & EDGE_ABNORMAL) |
17192884 | 593 | for (phi = phi_nodes (e->dest); phi; phi = PHI_CHAIN (phi)) |
6de9cd9a DN |
594 | { |
595 | /* Visit each PHI on the destination side of this abnormal | |
596 | edge, and attempt to coalesce the argument with the result. */ | |
597 | var = PHI_RESULT (phi); | |
598 | x = var_to_partition (map, var); | |
599 | ||
600 | /* Ignore results which are not relevant. */ | |
601 | if (x == NO_PARTITION) | |
602 | continue; | |
603 | ||
604 | y = phi_arg_from_edge (phi, e); | |
1e128c5f | 605 | gcc_assert (y != -1); |
6de9cd9a DN |
606 | |
607 | tmp = PHI_ARG_DEF (phi, y); | |
1e128c5f | 608 | #ifdef ENABLE_CHECKING |
6de9cd9a DN |
609 | if (!phi_ssa_name_p (tmp)) |
610 | { | |
611 | print_exprs_edge (stderr, e, | |
612 | "\nConstant argument in PHI. Can't insert :", | |
613 | var, " = ", tmp); | |
1e128c5f | 614 | internal_error ("SSA corruption"); |
6de9cd9a | 615 | } |
1e128c5f | 616 | #else |
b49ce401 | 617 | gcc_assert (phi_ssa_name_p (tmp)); |
1e128c5f | 618 | #endif |
6de9cd9a | 619 | y = var_to_partition (map, tmp); |
1e128c5f GB |
620 | gcc_assert (x != NO_PARTITION); |
621 | gcc_assert (y != NO_PARTITION); | |
622 | #ifdef ENABLE_CHECKING | |
6de9cd9a DN |
623 | if (root_var_find (rv, x) != root_var_find (rv, y)) |
624 | { | |
625 | print_exprs_edge (stderr, e, "\nDifferent root vars: ", | |
626 | root_var (rv, root_var_find (rv, x)), | |
627 | " and ", | |
628 | root_var (rv, root_var_find (rv, y))); | |
1e128c5f | 629 | internal_error ("SSA corruption"); |
6de9cd9a | 630 | } |
1e128c5f GB |
631 | #else |
632 | gcc_assert (root_var_find (rv, x) == root_var_find (rv, y)); | |
633 | #endif | |
6de9cd9a DN |
634 | |
635 | if (x != y) | |
636 | { | |
1e128c5f GB |
637 | #ifdef ENABLE_CHECKING |
638 | if (conflict_graph_conflict_p (graph, x, y)) | |
6de9cd9a DN |
639 | { |
640 | print_exprs_edge (stderr, e, "\n Conflict ", | |
641 | partition_to_var (map, x), | |
642 | " and ", partition_to_var (map, y)); | |
1e128c5f | 643 | internal_error ("SSA corruption"); |
6de9cd9a | 644 | } |
1e128c5f GB |
645 | #else |
646 | gcc_assert (!conflict_graph_conflict_p (graph, x, y)); | |
647 | #endif | |
648 | ||
649 | /* Now map the partitions back to their real variables. */ | |
650 | var = partition_to_var (map, x); | |
651 | tmp = partition_to_var (map, y); | |
652 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
653 | { | |
654 | print_exprs_edge (dump_file, e, | |
655 | "ABNORMAL: Coalescing ", | |
656 | var, " and ", tmp); | |
657 | } | |
658 | #ifdef ENABLE_CHECKING | |
659 | if (var_union (map, var, tmp) == NO_PARTITION) | |
660 | { | |
661 | print_exprs_edge (stderr, e, "\nUnable to coalesce", | |
662 | partition_to_var (map, x), " and ", | |
663 | partition_to_var (map, y)); | |
664 | internal_error ("SSA corruption"); | |
665 | } | |
666 | #else | |
667 | gcc_assert (var_union (map, var, tmp) != NO_PARTITION); | |
668 | #endif | |
669 | conflict_graph_merge_regs (graph, x, y); | |
6de9cd9a DN |
670 | } |
671 | } | |
672 | } | |
673 | ||
674 | ||
675 | /* Reduce the number of live ranges in MAP. Live range information is | |
676 | returned if FLAGS indicates that we are combining temporaries, otherwise | |
677 | NULL is returned. The only partitions which are associated with actual | |
678 | variables at this point are those which are forced to be coalesced for | |
679 | various reason. (live on entry, live across abnormal edges, etc.). */ | |
680 | ||
681 | static tree_live_info_p | |
682 | coalesce_ssa_name (var_map map, int flags) | |
683 | { | |
684 | int num, x, i; | |
685 | sbitmap live; | |
686 | tree var, phi; | |
687 | root_var_p rv; | |
688 | tree_live_info_p liveinfo; | |
689 | var_ann_t ann; | |
690 | conflict_graph graph; | |
691 | basic_block bb; | |
692 | coalesce_list_p cl = NULL; | |
693 | ||
694 | if (num_var_partitions (map) <= 1) | |
695 | return NULL; | |
696 | ||
697 | /* If no preference given, use cheap coalescing of all partitions. */ | |
698 | if ((flags & (SSANORM_COALESCE_PARTITIONS | SSANORM_USE_COALESCE_LIST)) == 0) | |
699 | flags |= SSANORM_COALESCE_PARTITIONS; | |
700 | ||
701 | liveinfo = calculate_live_on_entry (map); | |
702 | calculate_live_on_exit (liveinfo); | |
703 | rv = root_var_init (map); | |
704 | ||
705 | /* Remove single element variable from the list. */ | |
706 | root_var_compact (rv); | |
707 | ||
708 | if (flags & SSANORM_USE_COALESCE_LIST) | |
709 | { | |
710 | cl = create_coalesce_list (map); | |
711 | ||
712 | /* Add all potential copies via PHI arguments to the list. */ | |
713 | FOR_EACH_BB (bb) | |
714 | { | |
17192884 | 715 | for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi)) |
6de9cd9a DN |
716 | { |
717 | tree res = PHI_RESULT (phi); | |
718 | int p = var_to_partition (map, res); | |
719 | if (p == NO_PARTITION) | |
720 | continue; | |
721 | for (x = 0; x < PHI_NUM_ARGS (phi); x++) | |
722 | { | |
723 | tree arg = PHI_ARG_DEF (phi, x); | |
724 | int p2; | |
725 | ||
726 | if (TREE_CODE (arg) != SSA_NAME) | |
727 | continue; | |
728 | if (SSA_NAME_VAR (res) != SSA_NAME_VAR (arg)) | |
729 | continue; | |
730 | p2 = var_to_partition (map, PHI_ARG_DEF (phi, x)); | |
731 | if (p2 != NO_PARTITION) | |
732 | add_coalesce (cl, p, p2, 1); | |
733 | } | |
734 | } | |
735 | } | |
736 | ||
737 | /* Coalesce all the result decls together. */ | |
738 | var = NULL_TREE; | |
739 | i = 0; | |
740 | for (x = 0; x < num_var_partitions (map); x++) | |
741 | { | |
742 | tree p = partition_to_var (map, x); | |
743 | if (TREE_CODE (SSA_NAME_VAR(p)) == RESULT_DECL) | |
744 | { | |
745 | if (var == NULL_TREE) | |
746 | { | |
747 | var = p; | |
748 | i = x; | |
749 | } | |
750 | else | |
751 | add_coalesce (cl, i, x, 1); | |
752 | } | |
753 | } | |
754 | } | |
755 | ||
756 | /* Build a conflict graph. */ | |
757 | graph = build_tree_conflict_graph (liveinfo, rv, cl); | |
758 | ||
759 | if (cl) | |
760 | { | |
761 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
762 | { | |
763 | fprintf (dump_file, "Before sorting:\n"); | |
764 | dump_coalesce_list (dump_file, cl); | |
765 | } | |
766 | ||
767 | sort_coalesce_list (cl); | |
768 | ||
769 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
770 | { | |
771 | fprintf (dump_file, "\nAfter sorting:\n"); | |
772 | dump_coalesce_list (dump_file, cl); | |
773 | } | |
774 | } | |
775 | ||
776 | /* Put the single element variables back in. */ | |
777 | root_var_decompact (rv); | |
778 | ||
779 | /* First, coalesce all live on entry variables to their root variable. | |
9cf737f8 | 780 | This will ensure the first use is coming from the correct location. */ |
6de9cd9a DN |
781 | |
782 | live = sbitmap_alloc (num_var_partitions (map)); | |
783 | sbitmap_zero (live); | |
784 | ||
785 | /* Set 'live' vector to indicate live on entry partitions. */ | |
786 | num = num_var_partitions (map); | |
787 | for (x = 0 ; x < num; x++) | |
788 | { | |
789 | var = partition_to_var (map, x); | |
790 | if (default_def (SSA_NAME_VAR (var)) == var) | |
791 | SET_BIT (live, x); | |
792 | } | |
793 | ||
794 | if ((flags & SSANORM_COMBINE_TEMPS) == 0) | |
795 | { | |
796 | delete_tree_live_info (liveinfo); | |
797 | liveinfo = NULL; | |
798 | } | |
799 | ||
800 | /* Assign root variable as partition representative for each live on entry | |
801 | partition. */ | |
802 | EXECUTE_IF_SET_IN_SBITMAP (live, 0, x, | |
803 | { | |
804 | var = root_var (rv, root_var_find (rv, x)); | |
805 | ann = var_ann (var); | |
806 | /* If these aren't already coalesced... */ | |
807 | if (partition_to_var (map, x) != var) | |
808 | { | |
1e128c5f GB |
809 | /* This root variable should have not already been assigned |
810 | to another partition which is not coalesced with this one. */ | |
811 | gcc_assert (!ann->out_of_ssa_tag); | |
6de9cd9a DN |
812 | |
813 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
814 | { | |
815 | print_exprs (dump_file, "Must coalesce ", | |
816 | partition_to_var (map, x), | |
817 | " with the root variable ", var, ".\n"); | |
818 | } | |
819 | ||
820 | change_partition_var (map, var, x); | |
821 | } | |
822 | }); | |
823 | ||
824 | sbitmap_free (live); | |
825 | ||
826 | /* Coalesce partitions live across abnormal edges. */ | |
827 | coalesce_abnormal_edges (map, graph, rv); | |
828 | ||
829 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
830 | dump_var_map (dump_file, map); | |
831 | ||
832 | /* Coalesce partitions. */ | |
833 | if (flags & SSANORM_USE_COALESCE_LIST) | |
834 | coalesce_tpa_members (rv, graph, map, cl, | |
835 | ((dump_flags & TDF_DETAILS) ? dump_file | |
836 | : NULL)); | |
837 | ||
838 | ||
839 | if (flags & SSANORM_COALESCE_PARTITIONS) | |
840 | coalesce_tpa_members (rv, graph, map, NULL, | |
841 | ((dump_flags & TDF_DETAILS) ? dump_file | |
842 | : NULL)); | |
843 | if (cl) | |
844 | delete_coalesce_list (cl); | |
845 | root_var_delete (rv); | |
846 | conflict_graph_delete (graph); | |
847 | ||
848 | return liveinfo; | |
849 | } | |
850 | ||
851 | ||
852 | /* Take the ssa-name var_map MAP, and assign real variables to each | |
853 | partition. */ | |
854 | ||
855 | static void | |
856 | assign_vars (var_map map) | |
857 | { | |
858 | int x, i, num, rep; | |
859 | tree t, var; | |
860 | var_ann_t ann; | |
861 | root_var_p rv; | |
862 | ||
863 | rv = root_var_init (map); | |
864 | if (!rv) | |
865 | return; | |
866 | ||
867 | /* Coalescing may already have forced some partitions to their root | |
868 | variable. Find these and tag them. */ | |
869 | ||
870 | num = num_var_partitions (map); | |
871 | for (x = 0; x < num; x++) | |
872 | { | |
873 | var = partition_to_var (map, x); | |
874 | if (TREE_CODE (var) != SSA_NAME) | |
875 | { | |
876 | /* Coalescing will already have verified that more than one | |
877 | partition doesn't have the same root variable. Simply marked | |
878 | the variable as assigned. */ | |
879 | ann = var_ann (var); | |
880 | ann->out_of_ssa_tag = 1; | |
881 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
882 | { | |
883 | fprintf (dump_file, "partition %d has variable ", x); | |
884 | print_generic_expr (dump_file, var, TDF_SLIM); | |
885 | fprintf (dump_file, " assigned to it.\n"); | |
886 | } | |
887 | ||
888 | } | |
889 | } | |
890 | ||
891 | num = root_var_num (rv); | |
892 | for (x = 0; x < num; x++) | |
893 | { | |
894 | var = root_var (rv, x); | |
895 | ann = var_ann (var); | |
896 | for (i = root_var_first_partition (rv, x); | |
897 | i != ROOT_VAR_NONE; | |
898 | i = root_var_next_partition (rv, i)) | |
899 | { | |
900 | t = partition_to_var (map, i); | |
901 | ||
902 | if (t == var || TREE_CODE (t) != SSA_NAME) | |
903 | continue; | |
904 | ||
905 | rep = var_to_partition (map, t); | |
906 | ||
907 | if (!ann->out_of_ssa_tag) | |
908 | { | |
909 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
910 | print_exprs (dump_file, "", t, " --> ", var, "\n"); | |
911 | change_partition_var (map, var, rep); | |
912 | continue; | |
913 | } | |
914 | ||
915 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
916 | print_exprs (dump_file, "", t, " not coalesced with ", var, | |
917 | ""); | |
918 | ||
919 | var = create_temp (t); | |
920 | change_partition_var (map, var, rep); | |
921 | ann = var_ann (var); | |
922 | ||
923 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
924 | { | |
925 | fprintf (dump_file, " --> New temp: '"); | |
926 | print_generic_expr (dump_file, var, TDF_SLIM); | |
927 | fprintf (dump_file, "'\n"); | |
928 | } | |
929 | } | |
930 | } | |
931 | ||
932 | root_var_delete (rv); | |
933 | } | |
934 | ||
935 | ||
d00ad49b AM |
936 | /* Replace use operand P with whatever variable it has been rewritten to based |
937 | on the partitions in MAP. EXPR is an optional expression vector over SSA | |
938 | versions which is used to replace P with an expression instead of a variable. | |
6de9cd9a DN |
939 | If the stmt is changed, return true. */ |
940 | ||
941 | static inline bool | |
d00ad49b | 942 | replace_use_variable (var_map map, use_operand_p p, tree *expr) |
6de9cd9a DN |
943 | { |
944 | tree new_var; | |
d00ad49b | 945 | tree var = USE_FROM_PTR (p); |
6de9cd9a DN |
946 | |
947 | /* Check if we are replacing this variable with an expression. */ | |
948 | if (expr) | |
949 | { | |
d00ad49b | 950 | int version = SSA_NAME_VERSION (var); |
6de9cd9a DN |
951 | if (expr[version]) |
952 | { | |
953 | tree new_expr = TREE_OPERAND (expr[version], 1); | |
d00ad49b | 954 | SET_USE (p, new_expr); |
6de9cd9a DN |
955 | /* Clear the stmt's RHS, or GC might bite us. */ |
956 | TREE_OPERAND (expr[version], 1) = NULL_TREE; | |
957 | return true; | |
958 | } | |
959 | } | |
960 | ||
961 | new_var = var_to_partition_to_var (map, var); | |
962 | if (new_var) | |
963 | { | |
d00ad49b AM |
964 | SET_USE (p, new_var); |
965 | set_is_used (new_var); | |
966 | return true; | |
967 | } | |
968 | return false; | |
969 | } | |
970 | ||
971 | ||
972 | /* Replace def operand DEF_P with whatever variable it has been rewritten to | |
973 | based on the partitions in MAP. EXPR is an optional expression vector over | |
974 | SSA versions which is used to replace DEF_P with an expression instead of a | |
975 | variable. If the stmt is changed, return true. */ | |
976 | ||
977 | static inline bool | |
978 | replace_def_variable (var_map map, def_operand_p def_p, tree *expr) | |
979 | { | |
980 | tree new_var; | |
981 | tree var = DEF_FROM_PTR (def_p); | |
982 | ||
983 | /* Check if we are replacing this variable with an expression. */ | |
984 | if (expr) | |
985 | { | |
986 | int version = SSA_NAME_VERSION (var); | |
987 | if (expr[version]) | |
988 | { | |
989 | tree new_expr = TREE_OPERAND (expr[version], 1); | |
990 | SET_DEF (def_p, new_expr); | |
991 | /* Clear the stmt's RHS, or GC might bite us. */ | |
992 | TREE_OPERAND (expr[version], 1) = NULL_TREE; | |
993 | return true; | |
994 | } | |
995 | } | |
996 | ||
997 | new_var = var_to_partition_to_var (map, var); | |
998 | if (new_var) | |
999 | { | |
1000 | SET_DEF (def_p, new_var); | |
6de9cd9a DN |
1001 | set_is_used (new_var); |
1002 | return true; | |
1003 | } | |
1004 | return false; | |
1005 | } | |
1006 | ||
1007 | ||
1008 | /* Remove any PHI node which is a virtual PHI. */ | |
1009 | ||
1010 | static void | |
1011 | eliminate_virtual_phis (void) | |
1012 | { | |
1013 | basic_block bb; | |
1014 | tree phi, next; | |
1015 | ||
1016 | FOR_EACH_BB (bb) | |
1017 | { | |
1018 | for (phi = phi_nodes (bb); phi; phi = next) | |
1019 | { | |
17192884 | 1020 | next = PHI_CHAIN (phi); |
6de9cd9a DN |
1021 | if (!is_gimple_reg (SSA_NAME_VAR (PHI_RESULT (phi)))) |
1022 | { | |
1023 | #ifdef ENABLE_CHECKING | |
1024 | int i; | |
1025 | /* There should be no arguments of this PHI which are in | |
1026 | the partition list, or we get incorrect results. */ | |
1027 | for (i = 0; i < PHI_NUM_ARGS (phi); i++) | |
1028 | { | |
1029 | tree arg = PHI_ARG_DEF (phi, i); | |
1030 | if (TREE_CODE (arg) == SSA_NAME | |
1031 | && is_gimple_reg (SSA_NAME_VAR (arg))) | |
1032 | { | |
1033 | fprintf (stderr, "Argument of PHI is not virtual ("); | |
1034 | print_generic_expr (stderr, arg, TDF_SLIM); | |
1035 | fprintf (stderr, "), but the result is :"); | |
1036 | print_generic_stmt (stderr, phi, TDF_SLIM); | |
1e128c5f | 1037 | internal_error ("SSA corruption"); |
6de9cd9a DN |
1038 | } |
1039 | } | |
1040 | #endif | |
1041 | remove_phi_node (phi, NULL_TREE, bb); | |
1042 | } | |
1043 | } | |
1044 | } | |
1045 | } | |
1046 | ||
1047 | ||
1048 | /* This routine will coalesce variables in MAP of the same type which do not | |
1049 | interfere with each other. LIVEINFO is the live range info for variables | |
1050 | of interest. This will both reduce the memory footprint of the stack, and | |
1051 | allow us to coalesce together local copies of globals and scalarized | |
1052 | component refs. */ | |
1053 | ||
1054 | static void | |
1055 | coalesce_vars (var_map map, tree_live_info_p liveinfo) | |
1056 | { | |
1057 | basic_block bb; | |
1058 | type_var_p tv; | |
1059 | tree var; | |
1060 | int x, p, p2; | |
1061 | coalesce_list_p cl; | |
1062 | conflict_graph graph; | |
1063 | ||
1064 | cl = create_coalesce_list (map); | |
1065 | ||
1066 | /* Merge all the live on entry vectors for coalesced partitions. */ | |
1067 | for (x = 0; x < num_var_partitions (map); x++) | |
1068 | { | |
1069 | var = partition_to_var (map, x); | |
1070 | p = var_to_partition (map, var); | |
1071 | if (p != x) | |
1072 | live_merge_and_clear (liveinfo, p, x); | |
1073 | } | |
1074 | ||
1075 | /* When PHI nodes are turned into copies, the result of each PHI node | |
1076 | becomes live on entry to the block. Mark these now. */ | |
1077 | FOR_EACH_BB (bb) | |
1078 | { | |
1079 | tree phi, arg; | |
1080 | int p; | |
17192884 | 1081 | for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi)) |
6de9cd9a DN |
1082 | { |
1083 | p = var_to_partition (map, PHI_RESULT (phi)); | |
1084 | ||
1085 | /* Skip virtual PHI nodes. */ | |
1086 | if (p == NO_PARTITION) | |
1087 | continue; | |
1088 | ||
1089 | make_live_on_entry (liveinfo, bb, p); | |
1090 | ||
1091 | /* Each argument is a potential copy operation. Add any arguments | |
1092 | which are not coalesced to the result to the coalesce list. */ | |
1093 | for (x = 0; x < PHI_NUM_ARGS (phi); x++) | |
1094 | { | |
1095 | arg = PHI_ARG_DEF (phi, x); | |
1096 | if (!phi_ssa_name_p (arg)) | |
1097 | continue; | |
1098 | p2 = var_to_partition (map, arg); | |
1099 | if (p2 == NO_PARTITION) | |
1100 | continue; | |
1101 | if (p != p2) | |
1102 | add_coalesce (cl, p, p2, 1); | |
1103 | } | |
1104 | } | |
1105 | } | |
1106 | ||
1107 | ||
1108 | /* Re-calculate live on exit info. */ | |
1109 | calculate_live_on_exit (liveinfo); | |
1110 | ||
1111 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1112 | { | |
1113 | fprintf (dump_file, "Live range info for variable memory coalescing.\n"); | |
1114 | dump_live_info (dump_file, liveinfo, LIVEDUMP_ALL); | |
1115 | ||
1116 | fprintf (dump_file, "Coalesce list from phi nodes:\n"); | |
1117 | dump_coalesce_list (dump_file, cl); | |
1118 | } | |
1119 | ||
1120 | ||
1121 | tv = type_var_init (map); | |
1122 | if (dump_file) | |
1123 | type_var_dump (dump_file, tv); | |
1124 | type_var_compact (tv); | |
1125 | if (dump_file) | |
1126 | type_var_dump (dump_file, tv); | |
1127 | ||
1128 | graph = build_tree_conflict_graph (liveinfo, tv, cl); | |
1129 | ||
1130 | type_var_decompact (tv); | |
1131 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1132 | { | |
1133 | fprintf (dump_file, "type var list now looks like:n"); | |
1134 | type_var_dump (dump_file, tv); | |
1135 | ||
1136 | fprintf (dump_file, "Coalesce list after conflict graph build:\n"); | |
1137 | dump_coalesce_list (dump_file, cl); | |
1138 | } | |
1139 | ||
1140 | sort_coalesce_list (cl); | |
1141 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1142 | { | |
1143 | fprintf (dump_file, "Coalesce list after sorting:\n"); | |
1144 | dump_coalesce_list (dump_file, cl); | |
1145 | } | |
1146 | ||
1147 | coalesce_tpa_members (tv, graph, map, cl, | |
1148 | ((dump_flags & TDF_DETAILS) ? dump_file : NULL)); | |
1149 | ||
1150 | type_var_delete (tv); | |
1151 | delete_coalesce_list (cl); | |
1152 | } | |
1153 | ||
1154 | ||
1155 | /* Temporary Expression Replacement (TER) | |
1156 | ||
1157 | Replace SSA version variables during out-of-ssa with their defining | |
1158 | expression if there is only one use of the variable. | |
1159 | ||
1160 | A pass is made through the function, one block at a time. No cross block | |
1161 | information is tracked. | |
1162 | ||
1163 | Variables which only have one use, and whose defining stmt is considered | |
1164 | a replaceable expression (see check_replaceable) are entered into | |
1165 | consideration by adding a list of dependent partitions to the version_info | |
1166 | vector for that ssa_name_version. This information comes from the partition | |
1167 | mapping for each USE. At the same time, the partition_dep_list vector for | |
1168 | these partitions have this version number entered into their lists. | |
1169 | ||
1170 | When the use of a replaceable ssa_variable is encountered, the dependence | |
1171 | list in version_info[] is moved to the "pending_dependence" list in case | |
1172 | the current expression is also replaceable. (To be determined later in | |
1173 | processing this stmt.) version_info[] for the version is then updated to | |
1174 | point to the defining stmt and the 'replaceable' bit is set. | |
1175 | ||
1176 | Any partition which is defined by a statement 'kills' any expression which | |
1177 | is dependent on this partition. Every ssa version in the partitions' | |
1178 | dependence list is removed from future consideration. | |
1179 | ||
1180 | All virtual references are lumped together. Any expression which is | |
1181 | dependent on any virtual variable (via a VUSE) has a dependence added | |
1182 | to the special partition defined by VIRTUAL_PARTITION. | |
1183 | ||
a32b97a2 BB |
1184 | Whenever a V_MAY_DEF is seen, all expressions dependent this |
1185 | VIRTUAL_PARTITION are removed from consideration. | |
6de9cd9a DN |
1186 | |
1187 | At the end of a basic block, all expression are removed from consideration | |
1188 | in preparation for the next block. | |
1189 | ||
1190 | The end result is a vector over SSA_NAME_VERSION which is passed back to | |
1191 | rewrite_out_of_ssa. As the SSA variables are being rewritten, instead of | |
1192 | replacing the SSA_NAME tree element with the partition it was assigned, | |
1193 | it is replaced with the RHS of the defining expression. */ | |
1194 | ||
1195 | ||
61ada8ae | 1196 | /* Dependency list element. This can contain either a partition index or a |
6de9cd9a DN |
1197 | version number, depending on which list it is in. */ |
1198 | ||
1199 | typedef struct value_expr_d | |
1200 | { | |
1201 | int value; | |
1202 | struct value_expr_d *next; | |
1203 | } *value_expr_p; | |
1204 | ||
1205 | ||
1206 | /* Temporary Expression Replacement (TER) table information. */ | |
1207 | ||
1208 | typedef struct temp_expr_table_d | |
1209 | { | |
1210 | var_map map; | |
1211 | void **version_info; | |
1212 | value_expr_p *partition_dep_list; | |
1213 | bitmap replaceable; | |
1214 | bool saw_replaceable; | |
1215 | int virtual_partition; | |
1216 | bitmap partition_in_use; | |
1217 | value_expr_p free_list; | |
1218 | value_expr_p pending_dependence; | |
1219 | } *temp_expr_table_p; | |
1220 | ||
61ada8ae | 1221 | /* Used to indicate a dependency on V_MAY_DEFs. */ |
6de9cd9a DN |
1222 | #define VIRTUAL_PARTITION(table) (table->virtual_partition) |
1223 | ||
1224 | static temp_expr_table_p new_temp_expr_table (var_map); | |
1225 | static tree *free_temp_expr_table (temp_expr_table_p); | |
1226 | static inline value_expr_p new_value_expr (temp_expr_table_p); | |
1227 | static inline void free_value_expr (temp_expr_table_p, value_expr_p); | |
1228 | static inline value_expr_p find_value_in_list (value_expr_p, int, | |
1229 | value_expr_p *); | |
1230 | static inline void add_value_to_list (temp_expr_table_p, value_expr_p *, int); | |
1231 | static inline void add_info_to_list (temp_expr_table_p, value_expr_p *, | |
1232 | value_expr_p); | |
1233 | static value_expr_p remove_value_from_list (value_expr_p *, int); | |
1234 | static void add_dependance (temp_expr_table_p, int, tree); | |
1235 | static bool check_replaceable (temp_expr_table_p, tree); | |
1236 | static void finish_expr (temp_expr_table_p, int, bool); | |
1237 | static void mark_replaceable (temp_expr_table_p, tree); | |
1238 | static inline void kill_expr (temp_expr_table_p, int, bool); | |
1239 | static inline void kill_virtual_exprs (temp_expr_table_p, bool); | |
1240 | static void find_replaceable_in_bb (temp_expr_table_p, basic_block); | |
1241 | static tree *find_replaceable_exprs (var_map); | |
1242 | static void dump_replaceable_exprs (FILE *, tree *); | |
1243 | ||
1244 | ||
1245 | /* Create a new TER table for MAP. */ | |
1246 | ||
1247 | static temp_expr_table_p | |
1248 | new_temp_expr_table (var_map map) | |
1249 | { | |
1250 | temp_expr_table_p t; | |
1251 | ||
1252 | t = (temp_expr_table_p) xmalloc (sizeof (struct temp_expr_table_d)); | |
1253 | t->map = map; | |
1254 | ||
95a3742c | 1255 | t->version_info = xcalloc (num_ssa_names + 1, sizeof (void *)); |
6de9cd9a DN |
1256 | t->partition_dep_list = xcalloc (num_var_partitions (map) + 1, |
1257 | sizeof (value_expr_p)); | |
1258 | ||
1259 | t->replaceable = BITMAP_XMALLOC (); | |
1260 | t->partition_in_use = BITMAP_XMALLOC (); | |
1261 | ||
1262 | t->saw_replaceable = false; | |
1263 | t->virtual_partition = num_var_partitions (map); | |
1264 | t->free_list = NULL; | |
1265 | t->pending_dependence = NULL; | |
1266 | ||
1267 | return t; | |
1268 | } | |
1269 | ||
1270 | ||
1271 | /* Free TER table T. If there are valid replacements, return the expression | |
1272 | vector. */ | |
1273 | ||
1274 | static tree * | |
1275 | free_temp_expr_table (temp_expr_table_p t) | |
1276 | { | |
1277 | value_expr_p p; | |
1278 | tree *ret = NULL; | |
1279 | ||
1280 | #ifdef ENABLE_CHECKING | |
1281 | int x; | |
1282 | for (x = 0; x <= num_var_partitions (t->map); x++) | |
e1537934 | 1283 | gcc_assert (!t->partition_dep_list[x]); |
6de9cd9a DN |
1284 | #endif |
1285 | ||
1286 | while ((p = t->free_list)) | |
1287 | { | |
1288 | t->free_list = p->next; | |
1289 | free (p); | |
1290 | } | |
1291 | ||
1292 | BITMAP_XFREE (t->partition_in_use); | |
1293 | BITMAP_XFREE (t->replaceable); | |
1294 | ||
1295 | free (t->partition_dep_list); | |
1296 | if (t->saw_replaceable) | |
1297 | ret = (tree *)t->version_info; | |
1298 | else | |
1299 | free (t->version_info); | |
1300 | ||
1301 | free (t); | |
1302 | return ret; | |
1303 | } | |
1304 | ||
1305 | ||
1306 | /* Allocate a new value list node. Take it from the free list in TABLE if | |
1307 | possible. */ | |
1308 | ||
1309 | static inline value_expr_p | |
1310 | new_value_expr (temp_expr_table_p table) | |
1311 | { | |
1312 | value_expr_p p; | |
1313 | if (table->free_list) | |
1314 | { | |
1315 | p = table->free_list; | |
1316 | table->free_list = p->next; | |
1317 | } | |
1318 | else | |
1319 | p = (value_expr_p) xmalloc (sizeof (struct value_expr_d)); | |
1320 | ||
1321 | return p; | |
1322 | } | |
1323 | ||
1324 | ||
1325 | /* Add value list node P to the free list in TABLE. */ | |
1326 | ||
1327 | static inline void | |
1328 | free_value_expr (temp_expr_table_p table, value_expr_p p) | |
1329 | { | |
1330 | p->next = table->free_list; | |
1331 | table->free_list = p; | |
1332 | } | |
1333 | ||
1334 | ||
1335 | /* Find VALUE if its in LIST. Return a pointer to the list object if found, | |
1336 | else return NULL. If LAST_PTR is provided, it will point to the previous | |
1337 | item upon return, or NULL if this is the first item in the list. */ | |
1338 | ||
1339 | static inline value_expr_p | |
1340 | find_value_in_list (value_expr_p list, int value, value_expr_p *last_ptr) | |
1341 | { | |
1342 | value_expr_p curr; | |
1343 | value_expr_p last = NULL; | |
1344 | ||
1345 | for (curr = list; curr; last = curr, curr = curr->next) | |
1346 | { | |
1347 | if (curr->value == value) | |
1348 | break; | |
1349 | } | |
1350 | if (last_ptr) | |
1351 | *last_ptr = last; | |
1352 | return curr; | |
1353 | } | |
1354 | ||
1355 | ||
1356 | /* Add VALUE to LIST, if it isn't already present. TAB is the expression | |
1357 | table */ | |
1358 | ||
1359 | static inline void | |
1360 | add_value_to_list (temp_expr_table_p tab, value_expr_p *list, int value) | |
1361 | { | |
1362 | value_expr_p info; | |
1363 | ||
1364 | if (!find_value_in_list (*list, value, NULL)) | |
1365 | { | |
1366 | info = new_value_expr (tab); | |
1367 | info->value = value; | |
1368 | info->next = *list; | |
1369 | *list = info; | |
1370 | } | |
1371 | } | |
1372 | ||
1373 | ||
1374 | /* Add value node INFO if it's value isn't already in LIST. Free INFO if | |
1375 | it is already in the list. TAB is the expression table. */ | |
1376 | ||
1377 | static inline void | |
1378 | add_info_to_list (temp_expr_table_p tab, value_expr_p *list, value_expr_p info) | |
1379 | { | |
1380 | if (find_value_in_list (*list, info->value, NULL)) | |
1381 | free_value_expr (tab, info); | |
1382 | else | |
1383 | { | |
1384 | info->next = *list; | |
1385 | *list = info; | |
1386 | } | |
1387 | } | |
1388 | ||
1389 | ||
1390 | /* Look for VALUE in LIST. If found, remove it from the list and return it's | |
1391 | pointer. */ | |
1392 | ||
1393 | static value_expr_p | |
1394 | remove_value_from_list (value_expr_p *list, int value) | |
1395 | { | |
1396 | value_expr_p info, last; | |
1397 | ||
1398 | info = find_value_in_list (*list, value, &last); | |
1399 | if (!info) | |
1400 | return NULL; | |
1401 | if (!last) | |
1402 | *list = info->next; | |
1403 | else | |
1404 | last->next = info->next; | |
1405 | ||
1406 | return info; | |
1407 | } | |
1408 | ||
1409 | ||
61ada8ae KH |
1410 | /* Add a dependency between the def of ssa VERSION and VAR. If VAR is |
1411 | replaceable by an expression, add a dependence each of the elements of the | |
6de9cd9a DN |
1412 | expression. These are contained in the pending list. TAB is the |
1413 | expression table. */ | |
1414 | ||
1415 | static void | |
1416 | add_dependance (temp_expr_table_p tab, int version, tree var) | |
1417 | { | |
1418 | int i, x; | |
1419 | value_expr_p info; | |
1420 | ||
1421 | i = SSA_NAME_VERSION (var); | |
1422 | if (bitmap_bit_p (tab->replaceable, i)) | |
1423 | { | |
1424 | /* This variable is being substituted, so use whatever dependences | |
1425 | were queued up when we marked this as replaceable earlier. */ | |
1426 | while ((info = tab->pending_dependence)) | |
1427 | { | |
1428 | tab->pending_dependence = info->next; | |
1429 | /* Get the partition this variable was dependent on. Reuse this | |
1430 | object to represent the current expression instead. */ | |
1431 | x = info->value; | |
1432 | info->value = version; | |
1433 | add_info_to_list (tab, &(tab->partition_dep_list[x]), info); | |
1434 | add_value_to_list (tab, | |
1435 | (value_expr_p *)&(tab->version_info[version]), x); | |
1436 | bitmap_set_bit (tab->partition_in_use, x); | |
1437 | } | |
1438 | } | |
1439 | else | |
1440 | { | |
1441 | i = var_to_partition (tab->map, var); | |
1e128c5f | 1442 | gcc_assert (i != NO_PARTITION); |
6de9cd9a DN |
1443 | add_value_to_list (tab, &(tab->partition_dep_list[i]), version); |
1444 | add_value_to_list (tab, | |
1445 | (value_expr_p *)&(tab->version_info[version]), i); | |
1446 | bitmap_set_bit (tab->partition_in_use, i); | |
1447 | } | |
1448 | } | |
1449 | ||
1450 | ||
1451 | /* Check if expression STMT is suitable for replacement in table TAB. If so, | |
1452 | create an expression entry. Return true if this stmt is replaceable. */ | |
1453 | ||
1454 | static bool | |
1455 | check_replaceable (temp_expr_table_p tab, tree stmt) | |
1456 | { | |
1457 | stmt_ann_t ann; | |
1458 | vuse_optype vuseops; | |
1459 | def_optype defs; | |
1460 | use_optype uses; | |
1461 | tree var, def; | |
4c124b4c | 1462 | int num_use_ops, version; |
6de9cd9a | 1463 | var_map map = tab->map; |
4c124b4c | 1464 | ssa_op_iter iter; |
6de9cd9a DN |
1465 | |
1466 | if (TREE_CODE (stmt) != MODIFY_EXPR) | |
1467 | return false; | |
1468 | ||
1469 | ann = stmt_ann (stmt); | |
1470 | defs = DEF_OPS (ann); | |
1471 | ||
1472 | /* Punt if there is more than 1 def, or more than 1 use. */ | |
1473 | if (NUM_DEFS (defs) != 1) | |
1474 | return false; | |
1475 | def = DEF_OP (defs, 0); | |
1476 | if (version_ref_count (map, def) != 1) | |
1477 | return false; | |
1478 | ||
a32b97a2 BB |
1479 | /* There must be no V_MAY_DEFS. */ |
1480 | if (NUM_V_MAY_DEFS (V_MAY_DEF_OPS (ann)) != 0) | |
1481 | return false; | |
1482 | ||
1483 | /* There must be no V_MUST_DEFS. */ | |
1484 | if (NUM_V_MUST_DEFS (V_MUST_DEF_OPS (ann)) != 0) | |
6de9cd9a DN |
1485 | return false; |
1486 | ||
1487 | /* Float expressions must go through memory if float-store is on. */ | |
1488 | if (flag_float_store && FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (stmt, 1)))) | |
1489 | return false; | |
1490 | ||
1491 | uses = USE_OPS (ann); | |
1492 | num_use_ops = NUM_USES (uses); | |
1493 | vuseops = VUSE_OPS (ann); | |
1494 | ||
1495 | /* Any expression which has no virtual operands and no real operands | |
1496 | should have been propagated if it's possible to do anything with them. | |
1497 | If this happens here, it probably exists that way for a reason, so we | |
1498 | won't touch it. An example is: | |
1499 | b_4 = &tab | |
1500 | There are no virtual uses nor any real uses, so we just leave this | |
1501 | alone to be safe. */ | |
1502 | ||
1503 | if (num_use_ops == 0 && NUM_VUSES (vuseops) == 0) | |
1504 | return false; | |
1505 | ||
1506 | version = SSA_NAME_VERSION (def); | |
1507 | ||
61ada8ae | 1508 | /* Add this expression to the dependency list for each use partition. */ |
4c124b4c | 1509 | FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_USE) |
6de9cd9a | 1510 | { |
6de9cd9a DN |
1511 | add_dependance (tab, version, var); |
1512 | } | |
1513 | ||
1514 | /* If there are VUSES, add a dependence on virtual defs. */ | |
1515 | if (NUM_VUSES (vuseops) != 0) | |
1516 | { | |
1517 | add_value_to_list (tab, (value_expr_p *)&(tab->version_info[version]), | |
1518 | VIRTUAL_PARTITION (tab)); | |
1519 | add_value_to_list (tab, | |
1520 | &(tab->partition_dep_list[VIRTUAL_PARTITION (tab)]), | |
1521 | version); | |
1522 | bitmap_set_bit (tab->partition_in_use, VIRTUAL_PARTITION (tab)); | |
1523 | } | |
1524 | ||
1525 | return true; | |
1526 | } | |
1527 | ||
1528 | ||
1529 | /* This function will remove the expression for VERSION from replacement | |
1530 | consideration.n table TAB If 'replace' is true, it is marked as | |
1531 | replaceable, otherwise not. */ | |
1532 | ||
1533 | static void | |
1534 | finish_expr (temp_expr_table_p tab, int version, bool replace) | |
1535 | { | |
1536 | value_expr_p info, tmp; | |
1537 | int partition; | |
1538 | ||
61ada8ae | 1539 | /* Remove this expression from its dependent lists. The partition dependence |
6de9cd9a DN |
1540 | list is retained and transfered later to whomever uses this version. */ |
1541 | for (info = (value_expr_p) tab->version_info[version]; info; info = tmp) | |
1542 | { | |
1543 | partition = info->value; | |
1e128c5f | 1544 | gcc_assert (tab->partition_dep_list[partition]); |
6de9cd9a DN |
1545 | tmp = remove_value_from_list (&(tab->partition_dep_list[partition]), |
1546 | version); | |
1e128c5f | 1547 | gcc_assert (tmp); |
6de9cd9a | 1548 | free_value_expr (tab, tmp); |
61ada8ae | 1549 | /* Only clear the bit when the dependency list is emptied via |
6de9cd9a DN |
1550 | a replacement. Otherwise kill_expr will take care of it. */ |
1551 | if (!(tab->partition_dep_list[partition]) && replace) | |
1552 | bitmap_clear_bit (tab->partition_in_use, partition); | |
1553 | tmp = info->next; | |
1554 | if (!replace) | |
1555 | free_value_expr (tab, info); | |
1556 | } | |
1557 | ||
1558 | if (replace) | |
1559 | { | |
1560 | tab->saw_replaceable = true; | |
1561 | bitmap_set_bit (tab->replaceable, version); | |
1562 | } | |
1563 | else | |
1564 | { | |
1e128c5f | 1565 | gcc_assert (!bitmap_bit_p (tab->replaceable, version)); |
6de9cd9a DN |
1566 | tab->version_info[version] = NULL; |
1567 | } | |
1568 | } | |
1569 | ||
1570 | ||
1571 | /* Mark the expression associated with VAR as replaceable, and enter | |
1572 | the defining stmt into the version_info table TAB. */ | |
1573 | ||
1574 | static void | |
1575 | mark_replaceable (temp_expr_table_p tab, tree var) | |
1576 | { | |
1577 | value_expr_p info; | |
1578 | int version = SSA_NAME_VERSION (var); | |
1579 | finish_expr (tab, version, true); | |
1580 | ||
1581 | /* Move the dependence list to the pending list. */ | |
1582 | if (tab->version_info[version]) | |
1583 | { | |
1584 | info = (value_expr_p) tab->version_info[version]; | |
1585 | for ( ; info->next; info = info->next) | |
1586 | continue; | |
1587 | info->next = tab->pending_dependence; | |
1588 | tab->pending_dependence = (value_expr_p)tab->version_info[version]; | |
1589 | } | |
1590 | ||
1591 | tab->version_info[version] = SSA_NAME_DEF_STMT (var); | |
1592 | } | |
1593 | ||
1594 | ||
1595 | /* This function marks any expression in TAB which is dependent on PARTITION | |
1596 | as NOT replaceable. CLEAR_BIT is used to determine whether partition_in_use | |
1597 | should have its bit cleared. Since this routine can be called within an | |
1598 | EXECUTE_IF_SET_IN_BITMAP, the bit can't always be cleared. */ | |
1599 | ||
1600 | static inline void | |
1601 | kill_expr (temp_expr_table_p tab, int partition, bool clear_bit) | |
1602 | { | |
1603 | value_expr_p ptr; | |
1604 | ||
61ada8ae | 1605 | /* Mark every active expr dependent on this var as not replaceable. */ |
6de9cd9a DN |
1606 | while ((ptr = tab->partition_dep_list[partition]) != NULL) |
1607 | finish_expr (tab, ptr->value, false); | |
1608 | ||
1609 | if (clear_bit) | |
1610 | bitmap_clear_bit (tab->partition_in_use, partition); | |
1611 | } | |
1612 | ||
1613 | ||
61ada8ae | 1614 | /* This function kills all expressions in TAB which are dependent on virtual |
6de9cd9a DN |
1615 | DEFs. CLEAR_BIT determines whether partition_in_use gets cleared. */ |
1616 | ||
1617 | static inline void | |
1618 | kill_virtual_exprs (temp_expr_table_p tab, bool clear_bit) | |
1619 | { | |
1620 | kill_expr (tab, VIRTUAL_PARTITION (tab), clear_bit); | |
1621 | } | |
1622 | ||
1623 | ||
1624 | /* This function processes basic block BB, and looks for variables which can | |
1625 | be replaced by their expressions. Results are stored in TAB. */ | |
1626 | ||
1627 | static void | |
1628 | find_replaceable_in_bb (temp_expr_table_p tab, basic_block bb) | |
1629 | { | |
1630 | block_stmt_iterator bsi; | |
1631 | tree stmt, def; | |
1632 | stmt_ann_t ann; | |
4c124b4c | 1633 | int partition; |
6de9cd9a DN |
1634 | var_map map = tab->map; |
1635 | value_expr_p p; | |
4c124b4c | 1636 | ssa_op_iter iter; |
6de9cd9a DN |
1637 | |
1638 | for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) | |
1639 | { | |
1640 | stmt = bsi_stmt (bsi); | |
1641 | ann = stmt_ann (stmt); | |
1642 | ||
1643 | /* Determine if this stmt finishes an existing expression. */ | |
4c124b4c | 1644 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_USE) |
6de9cd9a | 1645 | { |
6de9cd9a DN |
1646 | if (tab->version_info[SSA_NAME_VERSION (def)]) |
1647 | { | |
1648 | /* Mark expression as replaceable unless stmt is volatile. */ | |
1649 | if (!ann->has_volatile_ops) | |
1650 | mark_replaceable (tab, def); | |
1651 | else | |
1652 | finish_expr (tab, SSA_NAME_VERSION (def), false); | |
1653 | } | |
1654 | } | |
1655 | ||
1656 | /* Next, see if this stmt kills off an active expression. */ | |
4c124b4c | 1657 | FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_DEF) |
6de9cd9a | 1658 | { |
6de9cd9a DN |
1659 | partition = var_to_partition (map, def); |
1660 | if (partition != NO_PARTITION && tab->partition_dep_list[partition]) | |
1661 | kill_expr (tab, partition, true); | |
1662 | } | |
1663 | ||
1664 | /* Now see if we are creating a new expression or not. */ | |
1665 | if (!ann->has_volatile_ops) | |
1666 | check_replaceable (tab, stmt); | |
1667 | ||
61ada8ae | 1668 | /* Free any unused dependency lists. */ |
6de9cd9a DN |
1669 | while ((p = tab->pending_dependence)) |
1670 | { | |
1671 | tab->pending_dependence = p->next; | |
1672 | free_value_expr (tab, p); | |
1673 | } | |
1674 | ||
a32b97a2 BB |
1675 | /* A V_MAY_DEF kills any expression using a virtual operand. */ |
1676 | if (NUM_V_MAY_DEFS (V_MAY_DEF_OPS (ann)) > 0) | |
1677 | kill_virtual_exprs (tab, true); | |
1678 | ||
1679 | /* A V_MUST_DEF kills any expression using a virtual operand. */ | |
1680 | if (NUM_V_MUST_DEFS (V_MUST_DEF_OPS (ann)) > 0) | |
6de9cd9a DN |
1681 | kill_virtual_exprs (tab, true); |
1682 | } | |
1683 | } | |
1684 | ||
1685 | ||
1686 | /* This function is the driver routine for replacement of temporary expressions | |
1687 | in the SSA->normal phase, operating on MAP. If there are replaceable | |
1688 | expressions, a table is returned which maps SSA versions to the | |
1689 | expressions they should be replaced with. A NULL_TREE indicates no | |
1690 | replacement should take place. If there are no replacements at all, | |
1691 | NULL is returned by the function, otherwise an expression vector indexed | |
1692 | by SSA_NAME version numbers. */ | |
1693 | ||
1694 | static tree * | |
1695 | find_replaceable_exprs (var_map map) | |
1696 | { | |
1697 | basic_block bb; | |
1698 | int i; | |
1699 | temp_expr_table_p table; | |
1700 | tree *ret; | |
1701 | ||
1702 | table = new_temp_expr_table (map); | |
1703 | FOR_EACH_BB (bb) | |
1704 | { | |
87c476a2 ZD |
1705 | bitmap_iterator bi; |
1706 | ||
6de9cd9a | 1707 | find_replaceable_in_bb (table, bb); |
87c476a2 | 1708 | EXECUTE_IF_SET_IN_BITMAP ((table->partition_in_use), 0, i, bi) |
6de9cd9a DN |
1709 | { |
1710 | kill_expr (table, i, false); | |
87c476a2 | 1711 | } |
6de9cd9a DN |
1712 | } |
1713 | ||
1714 | ret = free_temp_expr_table (table); | |
1715 | return ret; | |
1716 | } | |
1717 | ||
1718 | ||
1719 | /* Dump TER expression table EXPR to file F. */ | |
1720 | ||
1721 | static void | |
1722 | dump_replaceable_exprs (FILE *f, tree *expr) | |
1723 | { | |
1724 | tree stmt, var; | |
1725 | int x; | |
1726 | fprintf (f, "\nReplacing Expressions\n"); | |
95a3742c | 1727 | for (x = 0; x < (int)num_ssa_names + 1; x++) |
6de9cd9a DN |
1728 | if (expr[x]) |
1729 | { | |
1730 | stmt = expr[x]; | |
1731 | var = DEF_OP (STMT_DEF_OPS (stmt), 0); | |
1732 | print_generic_expr (f, var, TDF_SLIM); | |
1733 | fprintf (f, " replace with --> "); | |
1734 | print_generic_expr (f, TREE_OPERAND (stmt, 1), TDF_SLIM); | |
1735 | fprintf (f, "\n"); | |
1736 | } | |
1737 | fprintf (f, "\n"); | |
1738 | } | |
1739 | ||
1740 | ||
1741 | /* Helper function for discover_nonconstant_array_refs. | |
1742 | Look for ARRAY_REF nodes with non-constant indexes and mark them | |
1743 | addressable. */ | |
1744 | ||
1745 | static tree | |
1746 | discover_nonconstant_array_refs_r (tree * tp, int *walk_subtrees, | |
1747 | void *data ATTRIBUTE_UNUSED) | |
1748 | { | |
1749 | tree t = *tp; | |
1750 | ||
6615c446 | 1751 | if (IS_TYPE_OR_DECL_P (t)) |
6de9cd9a | 1752 | *walk_subtrees = 0; |
350fae66 | 1753 | else if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF) |
6de9cd9a | 1754 | { |
44de5aeb | 1755 | while (((TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF) |
8f44bc38 RK |
1756 | && is_gimple_min_invariant (TREE_OPERAND (t, 1)) |
1757 | && (!TREE_OPERAND (t, 2) | |
1758 | || is_gimple_min_invariant (TREE_OPERAND (t, 2)))) | |
6de9cd9a | 1759 | || (TREE_CODE (t) == COMPONENT_REF |
8f44bc38 RK |
1760 | && (!TREE_OPERAND (t,2) |
1761 | || is_gimple_min_invariant (TREE_OPERAND (t, 2)))) | |
1762 | || TREE_CODE (t) == BIT_FIELD_REF | |
1763 | || TREE_CODE (t) == REALPART_EXPR | |
1764 | || TREE_CODE (t) == IMAGPART_EXPR | |
1765 | || TREE_CODE (t) == VIEW_CONVERT_EXPR | |
1766 | || TREE_CODE (t) == NOP_EXPR | |
1767 | || TREE_CODE (t) == CONVERT_EXPR) | |
6de9cd9a DN |
1768 | t = TREE_OPERAND (t, 0); |
1769 | ||
44de5aeb | 1770 | if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF) |
6de9cd9a DN |
1771 | { |
1772 | t = get_base_address (t); | |
1773 | if (t && DECL_P (t)) | |
1774 | TREE_ADDRESSABLE (t) = 1; | |
1775 | } | |
1776 | ||
1777 | *walk_subtrees = 0; | |
1778 | } | |
1779 | ||
1780 | return NULL_TREE; | |
1781 | } | |
1782 | ||
1783 | ||
1784 | /* RTL expansion is not able to compile array references with variable | |
1785 | offsets for arrays stored in single register. Discover such | |
1786 | expressions and mark variables as addressable to avoid this | |
1787 | scenario. */ | |
1788 | ||
1789 | static void | |
1790 | discover_nonconstant_array_refs (void) | |
1791 | { | |
1792 | basic_block bb; | |
1793 | block_stmt_iterator bsi; | |
1794 | ||
1795 | FOR_EACH_BB (bb) | |
1796 | { | |
1797 | for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) | |
1798 | walk_tree (bsi_stmt_ptr (bsi), discover_nonconstant_array_refs_r, | |
1799 | NULL , NULL); | |
1800 | } | |
1801 | } | |
1802 | ||
1803 | ||
1804 | /* This function will rewrite the current program using the variable mapping | |
1805 | found in MAP. If the replacement vector VALUES is provided, any | |
1806 | occurrences of partitions with non-null entries in the vector will be | |
1807 | replaced with the expression in the vector instead of its mapped | |
1808 | variable. */ | |
1809 | ||
1810 | static void | |
1811 | rewrite_trees (var_map map, tree *values) | |
1812 | { | |
1813 | elim_graph g; | |
1814 | basic_block bb; | |
1815 | block_stmt_iterator si; | |
1816 | edge e; | |
1817 | tree phi; | |
1818 | bool changed; | |
1819 | ||
1820 | #ifdef ENABLE_CHECKING | |
1821 | /* Search for PHIs where the destination has no partition, but one | |
1822 | or more arguments has a partition. This should not happen and can | |
1823 | create incorrect code. */ | |
1824 | FOR_EACH_BB (bb) | |
1825 | { | |
1826 | tree phi; | |
1827 | ||
17192884 | 1828 | for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi)) |
6de9cd9a DN |
1829 | { |
1830 | tree T0 = var_to_partition_to_var (map, PHI_RESULT (phi)); | |
1831 | ||
1832 | if (T0 == NULL_TREE) | |
1833 | { | |
1834 | int i; | |
1835 | ||
1836 | for (i = 0; i < PHI_NUM_ARGS (phi); i++) | |
1837 | { | |
1838 | tree arg = PHI_ARG_DEF (phi, i); | |
1839 | ||
1840 | if (TREE_CODE (arg) == SSA_NAME | |
1841 | && var_to_partition (map, arg) != NO_PARTITION) | |
1842 | { | |
1843 | fprintf (stderr, "Argument of PHI is in a partition :("); | |
1844 | print_generic_expr (stderr, arg, TDF_SLIM); | |
1845 | fprintf (stderr, "), but the result is not :"); | |
1846 | print_generic_stmt (stderr, phi, TDF_SLIM); | |
1e128c5f | 1847 | internal_error ("SSA corruption"); |
6de9cd9a DN |
1848 | } |
1849 | } | |
1850 | } | |
1851 | } | |
1852 | } | |
1853 | #endif | |
1854 | ||
1855 | /* Replace PHI nodes with any required copies. */ | |
1856 | g = new_elim_graph (map->num_partitions); | |
1857 | g->map = map; | |
1858 | FOR_EACH_BB (bb) | |
1859 | { | |
1860 | for (si = bsi_start (bb); !bsi_end_p (si); ) | |
1861 | { | |
4c124b4c | 1862 | size_t num_uses, num_defs; |
6de9cd9a DN |
1863 | use_optype uses; |
1864 | def_optype defs; | |
1865 | tree stmt = bsi_stmt (si); | |
d00ad49b | 1866 | use_operand_p use_p; |
4c124b4c | 1867 | def_operand_p def_p; |
6de9cd9a DN |
1868 | int remove = 0, is_copy = 0; |
1869 | stmt_ann_t ann; | |
4c124b4c | 1870 | ssa_op_iter iter; |
6de9cd9a DN |
1871 | |
1872 | get_stmt_operands (stmt); | |
1873 | ann = stmt_ann (stmt); | |
1874 | changed = false; | |
1875 | ||
1876 | if (TREE_CODE (stmt) == MODIFY_EXPR | |
1877 | && (TREE_CODE (TREE_OPERAND (stmt, 1)) == SSA_NAME)) | |
1878 | is_copy = 1; | |
1879 | ||
1880 | uses = USE_OPS (ann); | |
1881 | num_uses = NUM_USES (uses); | |
4c124b4c | 1882 | FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE) |
6de9cd9a | 1883 | { |
d00ad49b | 1884 | if (replace_use_variable (map, use_p, values)) |
6de9cd9a DN |
1885 | changed = true; |
1886 | } | |
1887 | ||
1888 | defs = DEF_OPS (ann); | |
1889 | num_defs = NUM_DEFS (defs); | |
1890 | ||
1891 | /* Mark this stmt for removal if it is the list of replaceable | |
1892 | expressions. */ | |
1893 | if (values && num_defs == 1) | |
1894 | { | |
1895 | tree def = DEF_OP (defs, 0); | |
1896 | tree val; | |
1897 | val = values[SSA_NAME_VERSION (def)]; | |
1898 | if (val) | |
1899 | remove = 1; | |
1900 | } | |
1901 | if (!remove) | |
1902 | { | |
4c124b4c | 1903 | FOR_EACH_SSA_DEF_OPERAND (def_p, stmt, iter, SSA_OP_DEF) |
6de9cd9a | 1904 | { |
d00ad49b | 1905 | if (replace_def_variable (map, def_p, NULL)) |
6de9cd9a DN |
1906 | changed = true; |
1907 | ||
1908 | /* If both SSA_NAMEs coalesce to the same variable, | |
1909 | mark the now redundant copy for removal. */ | |
1910 | if (is_copy | |
1911 | && num_uses == 1 | |
d00ad49b | 1912 | && (DEF_FROM_PTR (def_p) == USE_OP (uses, 0))) |
6de9cd9a DN |
1913 | remove = 1; |
1914 | } | |
68b9f53b | 1915 | if (changed & !remove) |
6de9cd9a DN |
1916 | modify_stmt (stmt); |
1917 | } | |
1918 | ||
1919 | /* Remove any stmts marked for removal. */ | |
1920 | if (remove) | |
1921 | bsi_remove (&si); | |
1922 | else | |
1923 | bsi_next (&si); | |
1924 | } | |
1925 | ||
1926 | phi = phi_nodes (bb); | |
1927 | if (phi) | |
1928 | { | |
628f6a4e BE |
1929 | edge_iterator ei; |
1930 | FOR_EACH_EDGE (e, ei, bb->preds) | |
6de9cd9a DN |
1931 | eliminate_phi (e, phi_arg_from_edge (phi, e), g); |
1932 | } | |
1933 | } | |
1934 | ||
1935 | delete_elim_graph (g); | |
1936 | ||
1937 | /* If any copies were inserted on edges, actually insert them now. */ | |
1938 | bsi_commit_edge_inserts (NULL); | |
1939 | } | |
1940 | ||
1941 | ||
1942 | /* Remove the variables specified in MAP from SSA form. Any debug information | |
1943 | is sent to DUMP. FLAGS indicate what options should be used. */ | |
1944 | ||
56b043c8 | 1945 | static void |
6de9cd9a DN |
1946 | remove_ssa_form (FILE *dump, var_map map, int flags) |
1947 | { | |
1948 | tree_live_info_p liveinfo; | |
1949 | basic_block bb; | |
1950 | tree phi, next; | |
1951 | FILE *save; | |
1952 | tree *values = NULL; | |
1953 | ||
1954 | save = dump_file; | |
1955 | dump_file = dump; | |
1956 | ||
1957 | /* If we are not combining temps, don't calculate live ranges for variables | |
1958 | with only one SSA version. */ | |
1959 | if ((flags & SSANORM_COMBINE_TEMPS) == 0) | |
1960 | compact_var_map (map, VARMAP_NO_SINGLE_DEFS); | |
1961 | else | |
1962 | compact_var_map (map, VARMAP_NORMAL); | |
1963 | ||
1964 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1965 | dump_var_map (dump_file, map); | |
1966 | ||
1967 | liveinfo = coalesce_ssa_name (map, flags); | |
1968 | ||
1969 | /* Make sure even single occurrence variables are in the list now. */ | |
1970 | if ((flags & SSANORM_COMBINE_TEMPS) == 0) | |
1971 | compact_var_map (map, VARMAP_NORMAL); | |
1972 | ||
1973 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1974 | { | |
1975 | fprintf (dump_file, "After Coalescing:\n"); | |
1976 | dump_var_map (dump_file, map); | |
1977 | } | |
1978 | ||
1979 | if (flags & SSANORM_PERFORM_TER) | |
1980 | { | |
1981 | values = find_replaceable_exprs (map); | |
1982 | if (values && dump_file && (dump_flags & TDF_DETAILS)) | |
1983 | dump_replaceable_exprs (dump_file, values); | |
1984 | } | |
1985 | ||
1986 | /* Assign real variables to the partitions now. */ | |
1987 | assign_vars (map); | |
1988 | ||
1989 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1990 | { | |
1991 | fprintf (dump_file, "After Root variable replacement:\n"); | |
1992 | dump_var_map (dump_file, map); | |
1993 | } | |
1994 | ||
1995 | if ((flags & SSANORM_COMBINE_TEMPS) && liveinfo) | |
1996 | { | |
1997 | coalesce_vars (map, liveinfo); | |
1998 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1999 | { | |
2000 | fprintf (dump_file, "After variable memory coalescing:\n"); | |
2001 | dump_var_map (dump_file, map); | |
2002 | } | |
2003 | } | |
2004 | ||
2005 | if (liveinfo) | |
2006 | delete_tree_live_info (liveinfo); | |
2007 | ||
2008 | rewrite_trees (map, values); | |
2009 | ||
2010 | if (values) | |
2011 | free (values); | |
2012 | ||
2013 | /* Remove phi nodes which have been translated back to real variables. */ | |
2014 | FOR_EACH_BB (bb) | |
2015 | { | |
2016 | for (phi = phi_nodes (bb); phi; phi = next) | |
2017 | { | |
17192884 | 2018 | next = PHI_CHAIN (phi); |
6de9cd9a DN |
2019 | if ((flags & SSANORM_REMOVE_ALL_PHIS) |
2020 | || var_to_partition (map, PHI_RESULT (phi)) != NO_PARTITION) | |
2021 | remove_phi_node (phi, NULL_TREE, bb); | |
2022 | } | |
2023 | } | |
2024 | ||
2025 | dump_file = save; | |
2026 | } | |
2027 | ||
6de9cd9a DN |
2028 | /* Take the current function out of SSA form, as described in |
2029 | R. Morgan, ``Building an Optimizing Compiler'', | |
2030 | Butterworth-Heinemann, Boston, MA, 1998. pp 176-186. */ | |
2031 | ||
2032 | static void | |
2033 | rewrite_out_of_ssa (void) | |
2034 | { | |
2035 | var_map map; | |
2036 | int var_flags = 0; | |
2037 | int ssa_flags = (SSANORM_REMOVE_ALL_PHIS | SSANORM_USE_COALESCE_LIST); | |
2038 | ||
2039 | if (!flag_tree_live_range_split) | |
2040 | ssa_flags |= SSANORM_COALESCE_PARTITIONS; | |
2041 | ||
2042 | eliminate_virtual_phis (); | |
2043 | ||
2044 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2045 | dump_tree_cfg (dump_file, dump_flags & ~TDF_DETAILS); | |
2046 | ||
2047 | /* We cannot allow unssa to un-gimplify trees before we instrument them. */ | |
2048 | if (flag_tree_ter && !flag_mudflap) | |
2049 | var_flags = SSA_VAR_MAP_REF_COUNT; | |
2050 | ||
2051 | map = create_ssa_var_map (var_flags); | |
2052 | ||
2053 | if (flag_tree_combine_temps) | |
2054 | ssa_flags |= SSANORM_COMBINE_TEMPS; | |
2055 | if (flag_tree_ter && !flag_mudflap) | |
2056 | ssa_flags |= SSANORM_PERFORM_TER; | |
2057 | ||
2058 | remove_ssa_form (dump_file, map, ssa_flags); | |
2059 | ||
2060 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2061 | dump_tree_cfg (dump_file, dump_flags & ~TDF_DETAILS); | |
2062 | ||
2063 | /* Do some cleanups which reduce the amount of data the | |
2064 | tree->rtl expanders deal with. */ | |
2065 | cfg_remove_useless_stmts (); | |
2066 | ||
2067 | /* Flush out flow graph and SSA data. */ | |
2068 | delete_var_map (map); | |
2069 | ||
2070 | /* Mark arrays indexed with non-constant indices with TREE_ADDRESSABLE. */ | |
2071 | discover_nonconstant_array_refs (); | |
2072 | } | |
2073 | ||
2074 | ||
2075 | /* Define the parameters of the out of SSA pass. */ | |
2076 | ||
2077 | struct tree_opt_pass pass_del_ssa = | |
2078 | { | |
2079 | "optimized", /* name */ | |
2080 | NULL, /* gate */ | |
2081 | rewrite_out_of_ssa, /* execute */ | |
2082 | NULL, /* sub */ | |
2083 | NULL, /* next */ | |
2084 | 0, /* static_pass_number */ | |
2085 | TV_TREE_SSA_TO_NORMAL, /* tv_id */ | |
c1b763fa | 2086 | PROP_cfg | PROP_ssa | PROP_alias, /* properties_required */ |
6de9cd9a DN |
2087 | 0, /* properties_provided */ |
2088 | /* ??? If TER is enabled, we also kill gimple. */ | |
2089 | PROP_ssa, /* properties_destroyed */ | |
2090 | TODO_verify_ssa | TODO_verify_flow | |
2091 | | TODO_verify_stmts, /* todo_flags_start */ | |
9f8628ba PB |
2092 | TODO_dump_func | TODO_ggc_collect, /* todo_flags_finish */ |
2093 | 0 /* letter */ | |
6de9cd9a | 2094 | }; |