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6de9cd9a | 1 | /* Liveness for SSA trees. |
d1e082c2 | 2 | Copyright (C) 2003-2013 Free Software Foundation, Inc. |
6de9cd9a DN |
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 | |
9dcd6f09 | 9 | the Free Software Foundation; either version 3, or (at your option) |
6de9cd9a DN |
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 | |
9dcd6f09 NC |
18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
6de9cd9a DN |
20 | |
21 | #include "config.h" | |
22 | #include "system.h" | |
23 | #include "coretypes.h" | |
4a8fb1a1 | 24 | #include "hash-table.h" |
6de9cd9a DN |
25 | #include "tm.h" |
26 | #include "tree.h" | |
cf835838 | 27 | #include "gimple-pretty-print.h" |
6de9cd9a | 28 | #include "bitmap.h" |
7a300452 | 29 | #include "tree-ssa.h" |
7ee2468b SB |
30 | #include "timevar.h" |
31 | #include "dumpfile.h" | |
6de9cd9a | 32 | #include "tree-ssa-live.h" |
718f9c0f | 33 | #include "diagnostic-core.h" |
aee46bbd JH |
34 | #include "debug.h" |
35 | #include "flags.h" | |
c31c32f9 | 36 | #include "gimple.h" |
7290d709 | 37 | |
32ace6e2 AM |
38 | #ifdef ENABLE_CHECKING |
39 | static void verify_live_on_entry (tree_live_info_p); | |
40 | #endif | |
6de9cd9a | 41 | |
6de9cd9a | 42 | |
7290d709 AM |
43 | /* VARMAP maintains a mapping from SSA version number to real variables. |
44 | ||
45 | All SSA_NAMES are divided into partitions. Initially each ssa_name is the | |
46 | only member of it's own partition. Coalescing will attempt to group any | |
47 | ssa_names which occur in a copy or in a PHI node into the same partition. | |
48 | ||
49 | At the end of out-of-ssa, each partition becomes a "real" variable and is | |
50 | rewritten as a compiler variable. | |
51 | ||
fa10beec | 52 | The var_map data structure is used to manage these partitions. It allows |
7290d709 AM |
53 | partitions to be combined, and determines which partition belongs to what |
54 | ssa_name or variable, and vice versa. */ | |
55 | ||
56 | ||
4a8fb1a1 LC |
57 | /* Hashtable helpers. */ |
58 | ||
59 | struct tree_int_map_hasher : typed_noop_remove <tree_int_map> | |
60 | { | |
61 | typedef tree_int_map value_type; | |
62 | typedef tree_int_map compare_type; | |
63 | static inline hashval_t hash (const value_type *); | |
64 | static inline bool equal (const value_type *, const compare_type *); | |
65 | }; | |
66 | ||
67 | inline hashval_t | |
68 | tree_int_map_hasher::hash (const value_type *v) | |
69 | { | |
70 | return tree_map_base_hash (v); | |
71 | } | |
72 | ||
73 | inline bool | |
74 | tree_int_map_hasher::equal (const value_type *v, const compare_type *c) | |
75 | { | |
76 | return tree_int_map_eq (v, c); | |
77 | } | |
78 | ||
79 | ||
7290d709 AM |
80 | /* This routine will initialize the basevar fields of MAP. */ |
81 | ||
82 | static void | |
83 | var_map_base_init (var_map map) | |
84 | { | |
5f564b8f | 85 | int x, num_part; |
7290d709 | 86 | tree var; |
4a8fb1a1 | 87 | hash_table <tree_int_map_hasher> tree_to_index; |
5f564b8f | 88 | struct tree_int_map *m, *mapstorage; |
b8698a0f | 89 | |
7290d709 | 90 | num_part = num_var_partitions (map); |
4a8fb1a1 | 91 | tree_to_index.create (num_part); |
5f564b8f MM |
92 | /* We can have at most num_part entries in the hash tables, so it's |
93 | enough to allocate so many map elements once, saving some malloc | |
94 | calls. */ | |
95 | mapstorage = m = XNEWVEC (struct tree_int_map, num_part); | |
7290d709 AM |
96 | |
97 | /* If a base table already exists, clear it, otherwise create it. */ | |
5f564b8f | 98 | free (map->partition_to_base_index); |
7290d709 AM |
99 | map->partition_to_base_index = (int *) xmalloc (sizeof (int) * num_part); |
100 | ||
101 | /* Build the base variable list, and point partitions at their bases. */ | |
102 | for (x = 0; x < num_part; x++) | |
103 | { | |
5f564b8f MM |
104 | struct tree_int_map **slot; |
105 | unsigned baseindex; | |
7290d709 | 106 | var = partition_to_var (map, x); |
70b5e7dc RG |
107 | if (SSA_NAME_VAR (var)) |
108 | m->base.from = SSA_NAME_VAR (var); | |
109 | else | |
110 | /* This restricts what anonymous SSA names we can coalesce | |
111 | as it restricts the sets we compute conflicts for. | |
112 | Using TREE_TYPE to generate sets is the easies as | |
113 | type equivalency also holds for SSA names with the same | |
e91d0adb JL |
114 | underlying decl. |
115 | ||
116 | Check gimple_can_coalesce_p when changing this code. */ | |
117 | m->base.from = (TYPE_CANONICAL (TREE_TYPE (var)) | |
118 | ? TYPE_CANONICAL (TREE_TYPE (var)) | |
119 | : TREE_TYPE (var)); | |
7290d709 | 120 | /* If base variable hasn't been seen, set it up. */ |
4a8fb1a1 | 121 | slot = tree_to_index.find_slot (m, INSERT); |
5f564b8f MM |
122 | if (!*slot) |
123 | { | |
124 | baseindex = m - mapstorage; | |
125 | m->to = baseindex; | |
126 | *slot = m; | |
127 | m++; | |
7290d709 | 128 | } |
5f564b8f MM |
129 | else |
130 | baseindex = (*slot)->to; | |
131 | map->partition_to_base_index[x] = baseindex; | |
7290d709 AM |
132 | } |
133 | ||
5f564b8f | 134 | map->num_basevars = m - mapstorage; |
7290d709 | 135 | |
5f564b8f | 136 | free (mapstorage); |
4a8fb1a1 | 137 | tree_to_index. dispose (); |
7290d709 AM |
138 | } |
139 | ||
6de9cd9a | 140 | |
7290d709 | 141 | /* Remove the base table in MAP. */ |
6de9cd9a | 142 | |
7290d709 AM |
143 | static void |
144 | var_map_base_fini (var_map map) | |
145 | { | |
146 | /* Free the basevar info if it is present. */ | |
147 | if (map->partition_to_base_index != NULL) | |
148 | { | |
7290d709 AM |
149 | free (map->partition_to_base_index); |
150 | map->partition_to_base_index = NULL; | |
151 | map->num_basevars = 0; | |
152 | } | |
153 | } | |
6de9cd9a DN |
154 | /* Create a variable partition map of SIZE, initialize and return it. */ |
155 | ||
156 | var_map | |
157 | init_var_map (int size) | |
158 | { | |
159 | var_map map; | |
160 | ||
161 | map = (var_map) xmalloc (sizeof (struct _var_map)); | |
162 | map->var_partition = partition_new (size); | |
6de9cd9a | 163 | |
7290d709 AM |
164 | map->partition_to_view = NULL; |
165 | map->view_to_partition = NULL; | |
6de9cd9a DN |
166 | map->num_partitions = size; |
167 | map->partition_size = size; | |
7290d709 AM |
168 | map->num_basevars = 0; |
169 | map->partition_to_base_index = NULL; | |
6de9cd9a DN |
170 | return map; |
171 | } | |
172 | ||
173 | ||
174 | /* Free memory associated with MAP. */ | |
175 | ||
176 | void | |
177 | delete_var_map (var_map map) | |
178 | { | |
7290d709 | 179 | var_map_base_fini (map); |
6de9cd9a | 180 | partition_delete (map->var_partition); |
04695783 JM |
181 | free (map->partition_to_view); |
182 | free (map->view_to_partition); | |
6de9cd9a DN |
183 | free (map); |
184 | } | |
185 | ||
186 | ||
b8698a0f L |
187 | /* This function will combine the partitions in MAP for VAR1 and VAR2. It |
188 | Returns the partition which represents the new partition. If the two | |
9cf737f8 | 189 | partitions cannot be combined, NO_PARTITION is returned. */ |
6de9cd9a DN |
190 | |
191 | int | |
192 | var_union (var_map map, tree var1, tree var2) | |
193 | { | |
194 | int p1, p2, p3; | |
4e3825db MM |
195 | |
196 | gcc_assert (TREE_CODE (var1) == SSA_NAME); | |
197 | gcc_assert (TREE_CODE (var2) == SSA_NAME); | |
6de9cd9a | 198 | |
b8698a0f | 199 | /* This is independent of partition_to_view. If partition_to_view is |
6de9cd9a | 200 | on, then whichever one of these partitions is absorbed will never have a |
7290d709 | 201 | dereference into the partition_to_view array any more. */ |
6de9cd9a | 202 | |
4e3825db MM |
203 | p1 = partition_find (map->var_partition, SSA_NAME_VERSION (var1)); |
204 | p2 = partition_find (map->var_partition, SSA_NAME_VERSION (var2)); | |
6de9cd9a | 205 | |
1e128c5f GB |
206 | gcc_assert (p1 != NO_PARTITION); |
207 | gcc_assert (p2 != NO_PARTITION); | |
6de9cd9a DN |
208 | |
209 | if (p1 == p2) | |
210 | p3 = p1; | |
211 | else | |
212 | p3 = partition_union (map->var_partition, p1, p2); | |
213 | ||
7290d709 AM |
214 | if (map->partition_to_view) |
215 | p3 = map->partition_to_view[p3]; | |
6de9cd9a | 216 | |
6de9cd9a DN |
217 | return p3; |
218 | } | |
219 | ||
b8698a0f L |
220 | |
221 | /* Compress the partition numbers in MAP such that they fall in the range | |
6de9cd9a DN |
222 | 0..(num_partitions-1) instead of wherever they turned out during |
223 | the partitioning exercise. This removes any references to unused | |
224 | partitions, thereby allowing bitmaps and other vectors to be much | |
b8698a0f | 225 | denser. |
6de9cd9a DN |
226 | |
227 | This is implemented such that compaction doesn't affect partitioning. | |
228 | Ie., once partitions are created and possibly merged, running one | |
229 | or more different kind of compaction will not affect the partitions | |
230 | themselves. Their index might change, but all the same variables will | |
231 | still be members of the same partition group. This allows work on reduced | |
232 | sets, and no loss of information when a larger set is later desired. | |
233 | ||
234 | In particular, coalescing can work on partitions which have 2 or more | |
235 | definitions, and then 'recompact' later to include all the single | |
236 | definitions for assignment to program variables. */ | |
237 | ||
7290d709 | 238 | |
b8698a0f L |
239 | /* Set MAP back to the initial state of having no partition view. Return a |
240 | bitmap which has a bit set for each partition number which is in use in the | |
7290d709 AM |
241 | varmap. */ |
242 | ||
243 | static bitmap | |
244 | partition_view_init (var_map map) | |
6de9cd9a | 245 | { |
7290d709 AM |
246 | bitmap used; |
247 | int tmp; | |
248 | unsigned int x; | |
6de9cd9a | 249 | |
7290d709 | 250 | used = BITMAP_ALLOC (NULL); |
6de9cd9a | 251 | |
7290d709 AM |
252 | /* Already in a view? Abandon the old one. */ |
253 | if (map->partition_to_view) | |
6de9cd9a | 254 | { |
7290d709 AM |
255 | free (map->partition_to_view); |
256 | map->partition_to_view = NULL; | |
6de9cd9a | 257 | } |
7290d709 | 258 | if (map->view_to_partition) |
6de9cd9a | 259 | { |
7290d709 AM |
260 | free (map->view_to_partition); |
261 | map->view_to_partition = NULL; | |
6de9cd9a DN |
262 | } |
263 | ||
6de9cd9a | 264 | /* Find out which partitions are actually referenced. */ |
7290d709 | 265 | for (x = 0; x < map->partition_size; x++) |
6de9cd9a DN |
266 | { |
267 | tmp = partition_find (map->var_partition, x); | |
ea057359 | 268 | if (ssa_name (tmp) != NULL_TREE && !virtual_operand_p (ssa_name (tmp)) |
4e3825db MM |
269 | && (!has_zero_uses (ssa_name (tmp)) |
270 | || !SSA_NAME_IS_DEFAULT_DEF (ssa_name (tmp)))) | |
7290d709 | 271 | bitmap_set_bit (used, tmp); |
6de9cd9a DN |
272 | } |
273 | ||
7290d709 AM |
274 | map->num_partitions = map->partition_size; |
275 | return used; | |
276 | } | |
277 | ||
278 | ||
279 | /* This routine will finalize the view data for MAP based on the partitions | |
b8698a0f | 280 | set in SELECTED. This is either the same bitmap returned from |
7290d709 AM |
281 | partition_view_init, or a trimmed down version if some of those partitions |
282 | were not desired in this view. SELECTED is freed before returning. */ | |
283 | ||
b8698a0f | 284 | static void |
7290d709 AM |
285 | partition_view_fini (var_map map, bitmap selected) |
286 | { | |
287 | bitmap_iterator bi; | |
288 | unsigned count, i, x, limit; | |
7290d709 AM |
289 | |
290 | gcc_assert (selected); | |
291 | ||
292 | count = bitmap_count_bits (selected); | |
293 | limit = map->partition_size; | |
294 | ||
295 | /* If its a one-to-one ratio, we don't need any view compaction. */ | |
296 | if (count < limit) | |
6de9cd9a | 297 | { |
7290d709 AM |
298 | map->partition_to_view = (int *)xmalloc (limit * sizeof (int)); |
299 | memset (map->partition_to_view, 0xff, (limit * sizeof (int))); | |
300 | map->view_to_partition = (int *)xmalloc (count * sizeof (int)); | |
b6e7e9af | 301 | |
7290d709 AM |
302 | i = 0; |
303 | /* Give each selected partition an index. */ | |
304 | EXECUTE_IF_SET_IN_BITMAP (selected, 0, x, bi) | |
6de9cd9a | 305 | { |
7290d709 AM |
306 | map->partition_to_view[x] = i; |
307 | map->view_to_partition[i] = x; | |
7290d709 | 308 | i++; |
b6e7e9af | 309 | } |
7290d709 AM |
310 | gcc_assert (i == count); |
311 | map->num_partitions = i; | |
6de9cd9a | 312 | } |
7290d709 AM |
313 | |
314 | BITMAP_FREE (selected); | |
315 | } | |
316 | ||
317 | ||
b8698a0f | 318 | /* Create a partition view which includes all the used partitions in MAP. If |
7290d709 AM |
319 | WANT_BASES is true, create the base variable map as well. */ |
320 | ||
3f9b14ff | 321 | void |
7290d709 AM |
322 | partition_view_normal (var_map map, bool want_bases) |
323 | { | |
324 | bitmap used; | |
325 | ||
326 | used = partition_view_init (map); | |
327 | partition_view_fini (map, used); | |
328 | ||
329 | if (want_bases) | |
330 | var_map_base_init (map); | |
6de9cd9a | 331 | else |
7290d709 AM |
332 | var_map_base_fini (map); |
333 | } | |
334 | ||
335 | ||
b8698a0f L |
336 | /* Create a partition view in MAP which includes just partitions which occur in |
337 | the bitmap ONLY. If WANT_BASES is true, create the base variable map | |
7290d709 AM |
338 | as well. */ |
339 | ||
3f9b14ff | 340 | void |
7290d709 AM |
341 | partition_view_bitmap (var_map map, bitmap only, bool want_bases) |
342 | { | |
343 | bitmap used; | |
344 | bitmap new_partitions = BITMAP_ALLOC (NULL); | |
345 | unsigned x, p; | |
346 | bitmap_iterator bi; | |
347 | ||
348 | used = partition_view_init (map); | |
349 | EXECUTE_IF_SET_IN_BITMAP (only, 0, x, bi) | |
6de9cd9a | 350 | { |
7290d709 AM |
351 | p = partition_find (map->var_partition, x); |
352 | gcc_assert (bitmap_bit_p (used, p)); | |
353 | bitmap_set_bit (new_partitions, p); | |
6de9cd9a | 354 | } |
7290d709 | 355 | partition_view_fini (map, new_partitions); |
6de9cd9a | 356 | |
7290d709 AM |
357 | if (want_bases) |
358 | var_map_base_init (map); | |
359 | else | |
360 | var_map_base_fini (map); | |
6de9cd9a DN |
361 | } |
362 | ||
363 | ||
5f564b8f MM |
364 | static bitmap usedvars; |
365 | ||
329df070 MM |
366 | /* Mark VAR as used, so that it'll be preserved during rtl expansion. |
367 | Returns true if VAR wasn't marked before. */ | |
5f564b8f | 368 | |
329df070 | 369 | static inline bool |
5f564b8f MM |
370 | set_is_used (tree var) |
371 | { | |
329df070 | 372 | return bitmap_set_bit (usedvars, DECL_UID (var)); |
5f564b8f MM |
373 | } |
374 | ||
375 | /* Return true if VAR is marked as used. */ | |
376 | ||
377 | static inline bool | |
378 | is_used_p (tree var) | |
379 | { | |
380 | return bitmap_bit_p (usedvars, DECL_UID (var)); | |
381 | } | |
382 | ||
329df070 | 383 | static inline void mark_all_vars_used (tree *); |
6de9cd9a | 384 | |
727a31fa RH |
385 | /* Helper function for mark_all_vars_used, called via walk_tree. */ |
386 | ||
387 | static tree | |
329df070 | 388 | mark_all_vars_used_1 (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED) |
727a31fa RH |
389 | { |
390 | tree t = *tp; | |
aee46bbd JH |
391 | enum tree_code_class c = TREE_CODE_CLASS (TREE_CODE (t)); |
392 | tree b; | |
727a31fa | 393 | |
3f519b35 | 394 | if (TREE_CODE (t) == SSA_NAME) |
70b5e7dc RG |
395 | { |
396 | *walk_subtrees = 0; | |
397 | t = SSA_NAME_VAR (t); | |
398 | if (!t) | |
399 | return NULL; | |
400 | } | |
726a989a RB |
401 | |
402 | if (IS_EXPR_CODE_CLASS (c) | |
aee46bbd JH |
403 | && (b = TREE_BLOCK (t)) != NULL) |
404 | TREE_USED (b) = true; | |
3f519b35 | 405 | |
4d948885 RG |
406 | /* Ignore TMR_OFFSET and TMR_STEP for TARGET_MEM_REFS, as those |
407 | fields do not contain vars. */ | |
89632019 ZD |
408 | if (TREE_CODE (t) == TARGET_MEM_REF) |
409 | { | |
329df070 MM |
410 | mark_all_vars_used (&TMR_BASE (t)); |
411 | mark_all_vars_used (&TMR_INDEX (t)); | |
412 | mark_all_vars_used (&TMR_INDEX2 (t)); | |
89632019 ZD |
413 | *walk_subtrees = 0; |
414 | return NULL; | |
415 | } | |
416 | ||
727a31fa RH |
417 | /* Only need to mark VAR_DECLS; parameters and return results are not |
418 | eliminated as unused. */ | |
419 | if (TREE_CODE (t) == VAR_DECL) | |
900461f3 | 420 | { |
329df070 MM |
421 | /* When a global var becomes used for the first time also walk its |
422 | initializer (non global ones don't have any). */ | |
423 | if (set_is_used (t) && is_global_var (t)) | |
424 | mark_all_vars_used (&DECL_INITIAL (t)); | |
900461f3 | 425 | } |
ccf134c7 RG |
426 | /* remove_unused_scope_block_p requires information about labels |
427 | which are not DECL_IGNORED_P to tell if they might be used in the IL. */ | |
9c09f152 | 428 | else if (TREE_CODE (t) == LABEL_DECL) |
ccf134c7 RG |
429 | /* Although the TREE_USED values that the frontend uses would be |
430 | acceptable (albeit slightly over-conservative) for our purposes, | |
431 | init_vars_expansion clears TREE_USED for LABEL_DECLs too, so we | |
432 | must re-compute it here. */ | |
433 | TREE_USED (t) = 1; | |
727a31fa | 434 | |
6615c446 | 435 | if (IS_TYPE_OR_DECL_P (t)) |
727a31fa RH |
436 | *walk_subtrees = 0; |
437 | ||
438 | return NULL; | |
439 | } | |
440 | ||
aee46bbd JH |
441 | /* Mark the scope block SCOPE and its subblocks unused when they can be |
442 | possibly eliminated if dead. */ | |
443 | ||
444 | static void | |
445 | mark_scope_block_unused (tree scope) | |
446 | { | |
447 | tree t; | |
448 | TREE_USED (scope) = false; | |
449 | if (!(*debug_hooks->ignore_block) (scope)) | |
450 | TREE_USED (scope) = true; | |
451 | for (t = BLOCK_SUBBLOCKS (scope); t ; t = BLOCK_CHAIN (t)) | |
452 | mark_scope_block_unused (t); | |
453 | } | |
454 | ||
455 | /* Look if the block is dead (by possibly eliminating its dead subblocks) | |
b8698a0f | 456 | and return true if so. |
aee46bbd JH |
457 | Block is declared dead if: |
458 | 1) No statements are associated with it. | |
459 | 2) Declares no live variables | |
460 | 3) All subblocks are dead | |
461 | or there is precisely one subblocks and the block | |
462 | has same abstract origin as outer block and declares | |
463 | no variables, so it is pure wrapper. | |
cea618ac | 464 | When we are not outputting full debug info, we also eliminate dead variables |
aee46bbd JH |
465 | out of scope blocks to let them to be recycled by GGC and to save copying work |
466 | done by the inliner. */ | |
467 | ||
468 | static bool | |
329df070 | 469 | remove_unused_scope_block_p (tree scope) |
aee46bbd | 470 | { |
d1aed86b | 471 | tree *t, *next; |
aee46bbd | 472 | bool unused = !TREE_USED (scope); |
aee46bbd JH |
473 | int nsubblocks = 0; |
474 | ||
d1aed86b AO |
475 | for (t = &BLOCK_VARS (scope); *t; t = next) |
476 | { | |
910ad8de | 477 | next = &DECL_CHAIN (*t); |
d1aed86b AO |
478 | |
479 | /* Debug info of nested function refers to the block of the | |
61e04322 JH |
480 | function. We might stil call it even if all statements |
481 | of function it was nested into was elliminated. | |
b8698a0f | 482 | |
61e04322 JH |
483 | TODO: We can actually look into cgraph to see if function |
484 | will be output to file. */ | |
d1aed86b AO |
485 | if (TREE_CODE (*t) == FUNCTION_DECL) |
486 | unused = false; | |
2ce59df7 AO |
487 | |
488 | /* If a decl has a value expr, we need to instantiate it | |
489 | regardless of debug info generation, to avoid codegen | |
490 | differences in memory overlap tests. update_equiv_regs() may | |
491 | indirectly call validate_equiv_mem() to test whether a | |
492 | SET_DEST overlaps with others, and if the value expr changes | |
493 | by virtual register instantiation, we may get end up with | |
494 | different results. */ | |
495 | else if (TREE_CODE (*t) == VAR_DECL && DECL_HAS_VALUE_EXPR_P (*t)) | |
496 | unused = false; | |
497 | ||
a300e459 EB |
498 | /* Remove everything we don't generate debug info for. */ |
499 | else if (DECL_IGNORED_P (*t)) | |
b91bc349 | 500 | { |
910ad8de | 501 | *t = DECL_CHAIN (*t); |
b91bc349 JH |
502 | next = t; |
503 | } | |
504 | ||
d1aed86b AO |
505 | /* When we are outputting debug info, we usually want to output |
506 | info about optimized-out variables in the scope blocks. | |
507 | Exception are the scope blocks not containing any instructions | |
508 | at all so user can't get into the scopes at first place. */ | |
329df070 | 509 | else if (is_used_p (*t)) |
d1aed86b | 510 | unused = false; |
ccf134c7 RG |
511 | else if (TREE_CODE (*t) == LABEL_DECL && TREE_USED (*t)) |
512 | /* For labels that are still used in the IL, the decision to | |
513 | preserve them must not depend DEBUG_INFO_LEVEL, otherwise we | |
514 | risk having different ordering in debug vs. non-debug builds | |
515 | during inlining or versioning. | |
516 | A label appearing here (we have already checked DECL_IGNORED_P) | |
517 | should not be used in the IL unless it has been explicitly used | |
518 | before, so we use TREE_USED as an approximation. */ | |
519 | /* In principle, we should do the same here as for the debug case | |
520 | below, however, when debugging, there might be additional nested | |
521 | levels that keep an upper level with a label live, so we have to | |
522 | force this block to be considered used, too. */ | |
523 | unused = false; | |
d1aed86b AO |
524 | |
525 | /* When we are not doing full debug info, we however can keep around | |
526 | only the used variables for cfgexpand's memory packing saving quite | |
b8698a0f | 527 | a lot of memory. |
61e04322 JH |
528 | |
529 | For sake of -g3, we keep around those vars but we don't count this as | |
530 | use of block, so innermost block with no used vars and no instructions | |
531 | can be considered dead. We only want to keep around blocks user can | |
b8698a0f | 532 | breakpoint into and ask about value of optimized out variables. |
61e04322 | 533 | |
427f6cec AO |
534 | Similarly we need to keep around types at least until all |
535 | variables of all nested blocks are gone. We track no | |
536 | information on whether given type is used or not, so we have | |
537 | to keep them even when not emitting debug information, | |
538 | otherwise we may end up remapping variables and their (local) | |
539 | types in different orders depending on whether debug | |
540 | information is being generated. */ | |
541 | ||
542 | else if (TREE_CODE (*t) == TYPE_DECL | |
543 | || debug_info_level == DINFO_LEVEL_NORMAL | |
c7ba0cfb | 544 | || debug_info_level == DINFO_LEVEL_VERBOSE) |
61e04322 | 545 | ; |
3c8da8a5 | 546 | else |
d1aed86b | 547 | { |
910ad8de | 548 | *t = DECL_CHAIN (*t); |
d1aed86b AO |
549 | next = t; |
550 | } | |
551 | } | |
552 | ||
aee46bbd | 553 | for (t = &BLOCK_SUBBLOCKS (scope); *t ;) |
329df070 | 554 | if (remove_unused_scope_block_p (*t)) |
aee46bbd JH |
555 | { |
556 | if (BLOCK_SUBBLOCKS (*t)) | |
557 | { | |
558 | tree next = BLOCK_CHAIN (*t); | |
559 | tree supercontext = BLOCK_SUPERCONTEXT (*t); | |
cff7525f | 560 | |
aee46bbd | 561 | *t = BLOCK_SUBBLOCKS (*t); |
cff7525f JH |
562 | while (BLOCK_CHAIN (*t)) |
563 | { | |
564 | BLOCK_SUPERCONTEXT (*t) = supercontext; | |
565 | t = &BLOCK_CHAIN (*t); | |
566 | } | |
aee46bbd JH |
567 | BLOCK_CHAIN (*t) = next; |
568 | BLOCK_SUPERCONTEXT (*t) = supercontext; | |
569 | t = &BLOCK_CHAIN (*t); | |
570 | nsubblocks ++; | |
571 | } | |
572 | else | |
61e04322 | 573 | *t = BLOCK_CHAIN (*t); |
aee46bbd JH |
574 | } |
575 | else | |
576 | { | |
577 | t = &BLOCK_CHAIN (*t); | |
578 | nsubblocks ++; | |
579 | } | |
cff7525f JH |
580 | |
581 | ||
582 | if (!unused) | |
583 | ; | |
aee46bbd | 584 | /* Outer scope is always used. */ |
cff7525f JH |
585 | else if (!BLOCK_SUPERCONTEXT (scope) |
586 | || TREE_CODE (BLOCK_SUPERCONTEXT (scope)) == FUNCTION_DECL) | |
aee46bbd | 587 | unused = false; |
cff7525f JH |
588 | /* Innermost blocks with no live variables nor statements can be always |
589 | eliminated. */ | |
590 | else if (!nsubblocks) | |
591 | ; | |
cff7525f JH |
592 | /* For terse debug info we can eliminate info on unused variables. */ |
593 | else if (debug_info_level == DINFO_LEVEL_NONE | |
594 | || debug_info_level == DINFO_LEVEL_TERSE) | |
9f706f23 JJ |
595 | { |
596 | /* Even for -g0/-g1 don't prune outer scopes from artificial | |
597 | functions, otherwise diagnostics using tree_nonartificial_location | |
598 | will not be emitted properly. */ | |
599 | if (inlined_function_outer_scope_p (scope)) | |
600 | { | |
601 | tree ao = scope; | |
602 | ||
603 | while (ao | |
604 | && TREE_CODE (ao) == BLOCK | |
605 | && BLOCK_ABSTRACT_ORIGIN (ao) != ao) | |
606 | ao = BLOCK_ABSTRACT_ORIGIN (ao); | |
607 | if (ao | |
608 | && TREE_CODE (ao) == FUNCTION_DECL | |
609 | && DECL_DECLARED_INLINE_P (ao) | |
610 | && lookup_attribute ("artificial", DECL_ATTRIBUTES (ao))) | |
611 | unused = false; | |
612 | } | |
613 | } | |
526d73ab | 614 | else if (BLOCK_VARS (scope) || BLOCK_NUM_NONLOCALIZED_VARS (scope)) |
aee46bbd | 615 | unused = false; |
cff7525f JH |
616 | /* See if this block is important for representation of inlined function. |
617 | Inlined functions are always represented by block with | |
618 | block_ultimate_origin being set to FUNCTION_DECL and DECL_SOURCE_LOCATION | |
619 | set... */ | |
620 | else if (inlined_function_outer_scope_p (scope)) | |
621 | unused = false; | |
622 | else | |
623 | /* Verfify that only blocks with source location set | |
624 | are entry points to the inlined functions. */ | |
2f13f2de DC |
625 | gcc_assert (LOCATION_LOCUS (BLOCK_SOURCE_LOCATION (scope)) |
626 | == UNKNOWN_LOCATION); | |
5b4c43d7 EB |
627 | |
628 | TREE_USED (scope) = !unused; | |
aee46bbd JH |
629 | return unused; |
630 | } | |
7290d709 | 631 | |
b8698a0f | 632 | /* Mark all VAR_DECLS under *EXPR_P as used, so that they won't be |
727a31fa RH |
633 | eliminated during the tree->rtl conversion process. */ |
634 | ||
635 | static inline void | |
329df070 | 636 | mark_all_vars_used (tree *expr_p) |
727a31fa | 637 | { |
329df070 | 638 | walk_tree (expr_p, mark_all_vars_used_1, NULL, NULL); |
727a31fa RH |
639 | } |
640 | ||
5368224f DC |
641 | /* Helper function for clear_unused_block_pointer, called via walk_tree. */ |
642 | ||
643 | static tree | |
644 | clear_unused_block_pointer_1 (tree *tp, int *, void *) | |
645 | { | |
646 | if (EXPR_P (*tp) && TREE_BLOCK (*tp) | |
647 | && !TREE_USED (TREE_BLOCK (*tp))) | |
648 | TREE_SET_BLOCK (*tp, NULL); | |
5368224f DC |
649 | return NULL_TREE; |
650 | } | |
651 | ||
5d751b0c JJ |
652 | /* Set all block pointer in debug or clobber stmt to NULL if the block |
653 | is unused, so that they will not be streamed out. */ | |
5368224f DC |
654 | |
655 | static void | |
6040bb5f | 656 | clear_unused_block_pointer (void) |
5368224f DC |
657 | { |
658 | basic_block bb; | |
659 | gimple_stmt_iterator gsi; | |
28957eab | 660 | |
5368224f DC |
661 | FOR_EACH_BB (bb) |
662 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
663 | { | |
664 | unsigned i; | |
665 | tree b; | |
666 | gimple stmt = gsi_stmt (gsi); | |
667 | ||
5d751b0c | 668 | if (!is_gimple_debug (stmt) && !gimple_clobber_p (stmt)) |
5368224f DC |
669 | continue; |
670 | b = gimple_block (stmt); | |
671 | if (b && !TREE_USED (b)) | |
672 | gimple_set_block (stmt, NULL); | |
673 | for (i = 0; i < gimple_num_ops (stmt); i++) | |
674 | walk_tree (gimple_op_ptr (stmt, i), clear_unused_block_pointer_1, | |
675 | NULL, NULL); | |
676 | } | |
677 | } | |
ac80ba07 DN |
678 | |
679 | /* Dump scope blocks starting at SCOPE to FILE. INDENT is the | |
680 | indentation level and FLAGS is as in print_generic_expr. */ | |
61e04322 JH |
681 | |
682 | static void | |
683 | dump_scope_block (FILE *file, int indent, tree scope, int flags) | |
684 | { | |
685 | tree var, t; | |
526d73ab | 686 | unsigned int i; |
61e04322 | 687 | |
cff7525f JH |
688 | fprintf (file, "\n%*s{ Scope block #%i%s%s",indent, "" , BLOCK_NUMBER (scope), |
689 | TREE_USED (scope) ? "" : " (unused)", | |
690 | BLOCK_ABSTRACT (scope) ? " (abstract)": ""); | |
2f13f2de | 691 | if (LOCATION_LOCUS (BLOCK_SOURCE_LOCATION (scope)) != UNKNOWN_LOCATION) |
cff7525f JH |
692 | { |
693 | expanded_location s = expand_location (BLOCK_SOURCE_LOCATION (scope)); | |
694 | fprintf (file, " %s:%i", s.file, s.line); | |
695 | } | |
696 | if (BLOCK_ABSTRACT_ORIGIN (scope)) | |
61e04322 | 697 | { |
cff7525f JH |
698 | tree origin = block_ultimate_origin (scope); |
699 | if (origin) | |
700 | { | |
701 | fprintf (file, " Originating from :"); | |
702 | if (DECL_P (origin)) | |
703 | print_generic_decl (file, origin, flags); | |
704 | else | |
705 | fprintf (file, "#%i", BLOCK_NUMBER (origin)); | |
706 | } | |
61e04322 | 707 | } |
cff7525f | 708 | fprintf (file, " \n"); |
910ad8de | 709 | for (var = BLOCK_VARS (scope); var; var = DECL_CHAIN (var)) |
61e04322 | 710 | { |
83d70792 | 711 | fprintf (file, "%*s", indent, ""); |
61e04322 | 712 | print_generic_decl (file, var, flags); |
5f564b8f | 713 | fprintf (file, "\n"); |
61e04322 | 714 | } |
526d73ab JH |
715 | for (i = 0; i < BLOCK_NUM_NONLOCALIZED_VARS (scope); i++) |
716 | { | |
717 | fprintf (file, "%*s",indent, ""); | |
718 | print_generic_decl (file, BLOCK_NONLOCALIZED_VAR (scope, i), | |
719 | flags); | |
720 | fprintf (file, " (nonlocalized)\n"); | |
721 | } | |
61e04322 JH |
722 | for (t = BLOCK_SUBBLOCKS (scope); t ; t = BLOCK_CHAIN (t)) |
723 | dump_scope_block (file, indent + 2, t, flags); | |
cff7525f | 724 | fprintf (file, "\n%*s}\n",indent, ""); |
61e04322 JH |
725 | } |
726 | ||
c6a21142 RG |
727 | /* Dump the tree of lexical scopes starting at SCOPE to stderr. FLAGS |
728 | is as in print_generic_expr. */ | |
729 | ||
24e47c76 | 730 | DEBUG_FUNCTION void |
c6a21142 RG |
731 | debug_scope_block (tree scope, int flags) |
732 | { | |
733 | dump_scope_block (stderr, 0, scope, flags); | |
734 | } | |
735 | ||
ac80ba07 DN |
736 | |
737 | /* Dump the tree of lexical scopes of current_function_decl to FILE. | |
738 | FLAGS is as in print_generic_expr. */ | |
739 | ||
cff7525f JH |
740 | void |
741 | dump_scope_blocks (FILE *file, int flags) | |
742 | { | |
743 | dump_scope_block (file, 0, DECL_INITIAL (current_function_decl), flags); | |
744 | } | |
3f519b35 | 745 | |
ac80ba07 DN |
746 | |
747 | /* Dump the tree of lexical scopes of current_function_decl to stderr. | |
748 | FLAGS is as in print_generic_expr. */ | |
749 | ||
24e47c76 | 750 | DEBUG_FUNCTION void |
ac80ba07 DN |
751 | debug_scope_blocks (int flags) |
752 | { | |
753 | dump_scope_blocks (stderr, flags); | |
754 | } | |
755 | ||
3f519b35 RG |
756 | /* Remove local variables that are not referenced in the IL. */ |
757 | ||
758 | void | |
759 | remove_unused_locals (void) | |
760 | { | |
761 | basic_block bb; | |
46eb666a | 762 | tree var; |
329df070 | 763 | unsigned srcidx, dstidx, num; |
47598145 | 764 | bool have_local_clobbers = false; |
3f519b35 | 765 | |
89fbbe4e AO |
766 | /* Removing declarations from lexical blocks when not optimizing is |
767 | not only a waste of time, it actually causes differences in stack | |
768 | layout. */ | |
769 | if (!optimize) | |
770 | return; | |
771 | ||
a222c01a MM |
772 | timevar_push (TV_REMOVE_UNUSED); |
773 | ||
61e04322 | 774 | mark_scope_block_unused (DECL_INITIAL (current_function_decl)); |
726a989a | 775 | |
5f564b8f | 776 | usedvars = BITMAP_ALLOC (NULL); |
3f519b35 RG |
777 | |
778 | /* Walk the CFG marking all referenced symbols. */ | |
779 | FOR_EACH_BB (bb) | |
780 | { | |
726a989a RB |
781 | gimple_stmt_iterator gsi; |
782 | size_t i; | |
cc2a64dd JJ |
783 | edge_iterator ei; |
784 | edge e; | |
3f519b35 RG |
785 | |
786 | /* Walk the statements. */ | |
726a989a RB |
787 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
788 | { | |
789 | gimple stmt = gsi_stmt (gsi); | |
790 | tree b = gimple_block (stmt); | |
791 | ||
b5b8b0ac AO |
792 | if (is_gimple_debug (stmt)) |
793 | continue; | |
794 | ||
47598145 MM |
795 | if (gimple_clobber_p (stmt)) |
796 | { | |
797 | have_local_clobbers = true; | |
798 | continue; | |
799 | } | |
800 | ||
726a989a RB |
801 | if (b) |
802 | TREE_USED (b) = true; | |
3f519b35 | 803 | |
726a989a | 804 | for (i = 0; i < gimple_num_ops (stmt); i++) |
329df070 | 805 | mark_all_vars_used (gimple_op_ptr (gsi_stmt (gsi), i)); |
726a989a RB |
806 | } |
807 | ||
808 | for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
3f519b35 RG |
809 | { |
810 | use_operand_p arg_p; | |
811 | ssa_op_iter i; | |
726a989a RB |
812 | tree def; |
813 | gimple phi = gsi_stmt (gsi); | |
3f519b35 | 814 | |
ea057359 | 815 | if (virtual_operand_p (gimple_phi_result (phi))) |
3f519b35 RG |
816 | continue; |
817 | ||
726a989a | 818 | def = gimple_phi_result (phi); |
329df070 | 819 | mark_all_vars_used (&def); |
3f519b35 RG |
820 | |
821 | FOR_EACH_PHI_ARG (arg_p, phi, i, SSA_OP_ALL_USES) | |
822 | { | |
823 | tree arg = USE_FROM_PTR (arg_p); | |
5368224f DC |
824 | int index = PHI_ARG_INDEX_FROM_USE (arg_p); |
825 | tree block = | |
826 | LOCATION_BLOCK (gimple_phi_arg_location (phi, index)); | |
827 | if (block != NULL) | |
828 | TREE_USED (block) = true; | |
329df070 | 829 | mark_all_vars_used (&arg); |
3f519b35 RG |
830 | } |
831 | } | |
cc2a64dd JJ |
832 | |
833 | FOR_EACH_EDGE (e, ei, bb->succs) | |
6040bb5f | 834 | if (LOCATION_BLOCK (e->goto_locus) != NULL) |
5368224f | 835 | TREE_USED (LOCATION_BLOCK (e->goto_locus)) = true; |
3f519b35 RG |
836 | } |
837 | ||
47598145 MM |
838 | /* We do a two-pass approach about the out-of-scope clobbers. We want |
839 | to remove them if they are the only references to a local variable, | |
840 | but we want to retain them when there's any other. So the first pass | |
841 | ignores them, and the second pass (if there were any) tries to remove | |
842 | them. */ | |
843 | if (have_local_clobbers) | |
844 | FOR_EACH_BB (bb) | |
845 | { | |
846 | gimple_stmt_iterator gsi; | |
847 | ||
848 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi);) | |
849 | { | |
850 | gimple stmt = gsi_stmt (gsi); | |
851 | tree b = gimple_block (stmt); | |
852 | ||
853 | if (gimple_clobber_p (stmt)) | |
854 | { | |
855 | tree lhs = gimple_assign_lhs (stmt); | |
5d751b0c JJ |
856 | tree base = get_base_address (lhs); |
857 | /* Remove clobbers referencing unused vars, or clobbers | |
858 | with MEM_REF lhs referencing uninitialized pointers. */ | |
859 | if ((TREE_CODE (base) == VAR_DECL && !is_used_p (base)) | |
860 | || (TREE_CODE (lhs) == MEM_REF | |
861 | && TREE_CODE (TREE_OPERAND (lhs, 0)) == SSA_NAME | |
862 | && SSA_NAME_IS_DEFAULT_DEF (TREE_OPERAND (lhs, 0)) | |
863 | && (TREE_CODE (SSA_NAME_VAR (TREE_OPERAND (lhs, 0))) | |
864 | != PARM_DECL))) | |
47598145 MM |
865 | { |
866 | unlink_stmt_vdef (stmt); | |
867 | gsi_remove (&gsi, true); | |
868 | release_defs (stmt); | |
869 | continue; | |
870 | } | |
871 | if (b) | |
872 | TREE_USED (b) = true; | |
873 | } | |
874 | gsi_next (&gsi); | |
875 | } | |
876 | } | |
877 | ||
fc3103e7 JJ |
878 | cfun->has_local_explicit_reg_vars = false; |
879 | ||
329df070 | 880 | /* Remove unmarked local and global vars from local_decls. */ |
9771b263 | 881 | num = vec_safe_length (cfun->local_decls); |
2fed2012 | 882 | for (srcidx = 0, dstidx = 0; srcidx < num; srcidx++) |
3f519b35 | 883 | { |
9771b263 | 884 | var = (*cfun->local_decls)[srcidx]; |
9c09f152 | 885 | if (TREE_CODE (var) == VAR_DECL) |
3f519b35 | 886 | { |
329df070 | 887 | if (!is_used_p (var)) |
9c09f152 | 888 | { |
01c59d23 | 889 | tree def; |
ca5f4331 MM |
890 | if (cfun->nonlocal_goto_save_area |
891 | && TREE_OPERAND (cfun->nonlocal_goto_save_area, 0) == var) | |
892 | cfun->nonlocal_goto_save_area = NULL; | |
01c59d23 RG |
893 | /* Release any default def associated with var. */ |
894 | if ((def = ssa_default_def (cfun, var)) != NULL_TREE) | |
895 | { | |
896 | set_ssa_default_def (cfun, var, NULL_TREE); | |
897 | release_ssa_name (def); | |
898 | } | |
9c09f152 | 899 | continue; |
900461f3 | 900 | } |
3f519b35 | 901 | } |
9c09f152 RB |
902 | if (TREE_CODE (var) == VAR_DECL |
903 | && DECL_HARD_REGISTER (var) | |
904 | && !is_global_var (var)) | |
fc3103e7 | 905 | cfun->has_local_explicit_reg_vars = true; |
c021f10b | 906 | |
2fed2012 | 907 | if (srcidx != dstidx) |
9771b263 | 908 | (*cfun->local_decls)[dstidx] = var; |
2fed2012 | 909 | dstidx++; |
3f519b35 | 910 | } |
2fed2012 | 911 | if (dstidx != num) |
c0e50f72 RB |
912 | { |
913 | statistics_counter_event (cfun, "unused VAR_DECLs removed", num - dstidx); | |
914 | cfun->local_decls->truncate (dstidx); | |
915 | } | |
1431ce01 | 916 | |
329df070 | 917 | remove_unused_scope_block_p (DECL_INITIAL (current_function_decl)); |
5368224f | 918 | clear_unused_block_pointer (); |
1431ce01 | 919 | |
5f564b8f | 920 | BITMAP_FREE (usedvars); |
326648f1 | 921 | |
61e04322 JH |
922 | if (dump_file && (dump_flags & TDF_DETAILS)) |
923 | { | |
924 | fprintf (dump_file, "Scope blocks after cleanups:\n"); | |
cff7525f | 925 | dump_scope_blocks (dump_file, dump_flags); |
61e04322 | 926 | } |
a222c01a MM |
927 | |
928 | timevar_pop (TV_REMOVE_UNUSED); | |
3f519b35 RG |
929 | } |
930 | ||
3f9b14ff SB |
931 | /* Obstack for globale liveness info bitmaps. We don't want to put these |
932 | on the default obstack because these bitmaps can grow quite large and | |
933 | we'll hold on to all that memory until the end of the compiler run. | |
934 | As a bonus, delete_tree_live_info can destroy all the bitmaps by just | |
935 | releasing the whole obstack. */ | |
936 | static bitmap_obstack liveness_bitmap_obstack; | |
6de9cd9a DN |
937 | |
938 | /* Allocate and return a new live range information object base on MAP. */ | |
939 | ||
940 | static tree_live_info_p | |
941 | new_tree_live_info (var_map map) | |
942 | { | |
943 | tree_live_info_p live; | |
3f9b14ff | 944 | basic_block bb; |
6de9cd9a | 945 | |
3f9b14ff | 946 | live = XNEW (struct tree_live_info_d); |
6de9cd9a DN |
947 | live->map = map; |
948 | live->num_blocks = last_basic_block; | |
949 | ||
3f9b14ff SB |
950 | live->livein = XNEWVEC (bitmap_head, last_basic_block); |
951 | FOR_EACH_BB (bb) | |
952 | bitmap_initialize (&live->livein[bb->index], &liveness_bitmap_obstack); | |
6de9cd9a | 953 | |
3f9b14ff SB |
954 | live->liveout = XNEWVEC (bitmap_head, last_basic_block); |
955 | FOR_EACH_BB (bb) | |
956 | bitmap_initialize (&live->liveout[bb->index], &liveness_bitmap_obstack); | |
32ace6e2 AM |
957 | |
958 | live->work_stack = XNEWVEC (int, last_basic_block); | |
959 | live->stack_top = live->work_stack; | |
960 | ||
3f9b14ff | 961 | live->global = BITMAP_ALLOC (&liveness_bitmap_obstack); |
6de9cd9a DN |
962 | return live; |
963 | } | |
964 | ||
965 | ||
966 | /* Free storage for live range info object LIVE. */ | |
967 | ||
b8698a0f | 968 | void |
6de9cd9a DN |
969 | delete_tree_live_info (tree_live_info_p live) |
970 | { | |
3f9b14ff | 971 | bitmap_obstack_release (&liveness_bitmap_obstack); |
32ace6e2 | 972 | free (live->work_stack); |
32ace6e2 | 973 | free (live->liveout); |
32ace6e2 | 974 | free (live->livein); |
32ace6e2 | 975 | free (live); |
6de9cd9a DN |
976 | } |
977 | ||
978 | ||
b8698a0f L |
979 | /* Visit basic block BB and propagate any required live on entry bits from |
980 | LIVE into the predecessors. VISITED is the bitmap of visited blocks. | |
2e226e66 | 981 | TMP is a temporary work bitmap which is passed in to avoid reallocating |
32ace6e2 | 982 | it each time. */ |
6de9cd9a | 983 | |
b8698a0f | 984 | static void |
32ace6e2 AM |
985 | loe_visit_block (tree_live_info_p live, basic_block bb, sbitmap visited, |
986 | bitmap tmp) | |
6de9cd9a | 987 | { |
32ace6e2 AM |
988 | edge e; |
989 | bool change; | |
990 | edge_iterator ei; | |
991 | basic_block pred_bb; | |
992 | bitmap loe; | |
d7c028c0 | 993 | gcc_assert (!bitmap_bit_p (visited, bb->index)); |
6de9cd9a | 994 | |
d7c028c0 | 995 | bitmap_set_bit (visited, bb->index); |
32ace6e2 | 996 | loe = live_on_entry (live, bb); |
6de9cd9a | 997 | |
32ace6e2 | 998 | FOR_EACH_EDGE (e, ei, bb->preds) |
6de9cd9a | 999 | { |
32ace6e2 AM |
1000 | pred_bb = e->src; |
1001 | if (pred_bb == ENTRY_BLOCK_PTR) | |
1002 | continue; | |
7290d709 | 1003 | /* TMP is variables live-on-entry from BB that aren't defined in the |
b8698a0f | 1004 | predecessor block. This should be the live on entry vars to pred. |
32ace6e2 AM |
1005 | Note that liveout is the DEFs in a block while live on entry is |
1006 | being calculated. */ | |
3f9b14ff | 1007 | bitmap_and_compl (tmp, loe, &live->liveout[pred_bb->index]); |
32ace6e2 | 1008 | |
b8698a0f | 1009 | /* Add these bits to live-on-entry for the pred. if there are any |
32ace6e2 AM |
1010 | changes, and pred_bb has been visited already, add it to the |
1011 | revisit stack. */ | |
1012 | change = bitmap_ior_into (live_on_entry (live, pred_bb), tmp); | |
d7c028c0 | 1013 | if (bitmap_bit_p (visited, pred_bb->index) && change) |
32ace6e2 | 1014 | { |
d7c028c0 | 1015 | bitmap_clear_bit (visited, pred_bb->index); |
32ace6e2 AM |
1016 | *(live->stack_top)++ = pred_bb->index; |
1017 | } | |
6de9cd9a DN |
1018 | } |
1019 | } | |
1020 | ||
1021 | ||
b8698a0f | 1022 | /* Using LIVE, fill in all the live-on-entry blocks between the defs and uses |
2e226e66 | 1023 | of all the variables. */ |
6de9cd9a | 1024 | |
32ace6e2 AM |
1025 | static void |
1026 | live_worklist (tree_live_info_p live) | |
6de9cd9a | 1027 | { |
32ace6e2 | 1028 | unsigned b; |
6de9cd9a | 1029 | basic_block bb; |
32ace6e2 | 1030 | sbitmap visited = sbitmap_alloc (last_basic_block + 1); |
3f9b14ff | 1031 | bitmap tmp = BITMAP_ALLOC (&liveness_bitmap_obstack); |
6de9cd9a | 1032 | |
f61e445a | 1033 | bitmap_clear (visited); |
6de9cd9a | 1034 | |
110abdbc | 1035 | /* Visit all the blocks in reverse order and propagate live on entry values |
32ace6e2 AM |
1036 | into the predecessors blocks. */ |
1037 | FOR_EACH_BB_REVERSE (bb) | |
1038 | loe_visit_block (live, bb, visited, tmp); | |
6de9cd9a | 1039 | |
32ace6e2 AM |
1040 | /* Process any blocks which require further iteration. */ |
1041 | while (live->stack_top != live->work_stack) | |
6de9cd9a | 1042 | { |
32ace6e2 AM |
1043 | b = *--(live->stack_top); |
1044 | loe_visit_block (live, BASIC_BLOCK (b), visited, tmp); | |
1045 | } | |
6de9cd9a | 1046 | |
32ace6e2 AM |
1047 | BITMAP_FREE (tmp); |
1048 | sbitmap_free (visited); | |
1049 | } | |
6de9cd9a | 1050 | |
6de9cd9a | 1051 | |
2e226e66 | 1052 | /* Calculate the initial live on entry vector for SSA_NAME using immediate_use |
32ace6e2 AM |
1053 | links. Set the live on entry fields in LIVE. Def's are marked temporarily |
1054 | in the liveout vector. */ | |
6de9cd9a | 1055 | |
32ace6e2 AM |
1056 | static void |
1057 | set_var_live_on_entry (tree ssa_name, tree_live_info_p live) | |
1058 | { | |
1059 | int p; | |
726a989a | 1060 | gimple stmt; |
32ace6e2 AM |
1061 | use_operand_p use; |
1062 | basic_block def_bb = NULL; | |
1063 | imm_use_iterator imm_iter; | |
1064 | bool global = false; | |
6de9cd9a | 1065 | |
32ace6e2 AM |
1066 | p = var_to_partition (live->map, ssa_name); |
1067 | if (p == NO_PARTITION) | |
1068 | return; | |
6de9cd9a | 1069 | |
32ace6e2 AM |
1070 | stmt = SSA_NAME_DEF_STMT (ssa_name); |
1071 | if (stmt) | |
6de9cd9a | 1072 | { |
726a989a | 1073 | def_bb = gimple_bb (stmt); |
7290d709 | 1074 | /* Mark defs in liveout bitmap temporarily. */ |
32ace6e2 | 1075 | if (def_bb) |
3f9b14ff | 1076 | bitmap_set_bit (&live->liveout[def_bb->index], p); |
87c476a2 | 1077 | } |
32ace6e2 AM |
1078 | else |
1079 | def_bb = ENTRY_BLOCK_PTR; | |
6de9cd9a | 1080 | |
32ace6e2 AM |
1081 | /* Visit each use of SSA_NAME and if it isn't in the same block as the def, |
1082 | add it to the list of live on entry blocks. */ | |
1083 | FOR_EACH_IMM_USE_FAST (use, imm_iter, ssa_name) | |
6de9cd9a | 1084 | { |
726a989a | 1085 | gimple use_stmt = USE_STMT (use); |
32ace6e2 | 1086 | basic_block add_block = NULL; |
6de9cd9a | 1087 | |
726a989a | 1088 | if (gimple_code (use_stmt) == GIMPLE_PHI) |
32ace6e2 AM |
1089 | { |
1090 | /* Uses in PHI's are considered to be live at exit of the SRC block | |
1091 | as this is where a copy would be inserted. Check to see if it is | |
1092 | defined in that block, or whether its live on entry. */ | |
1093 | int index = PHI_ARG_INDEX_FROM_USE (use); | |
726a989a | 1094 | edge e = gimple_phi_arg_edge (use_stmt, index); |
32ace6e2 | 1095 | if (e->src != ENTRY_BLOCK_PTR) |
6de9cd9a | 1096 | { |
32ace6e2 AM |
1097 | if (e->src != def_bb) |
1098 | add_block = e->src; | |
6de9cd9a | 1099 | } |
32ace6e2 | 1100 | } |
b5b8b0ac AO |
1101 | else if (is_gimple_debug (use_stmt)) |
1102 | continue; | |
32ace6e2 AM |
1103 | else |
1104 | { | |
1105 | /* If its not defined in this block, its live on entry. */ | |
726a989a | 1106 | basic_block use_bb = gimple_bb (use_stmt); |
32ace6e2 AM |
1107 | if (use_bb != def_bb) |
1108 | add_block = use_bb; | |
b8698a0f | 1109 | } |
32ace6e2 AM |
1110 | |
1111 | /* If there was a live on entry use, set the bit. */ | |
1112 | if (add_block) | |
1113 | { | |
1114 | global = true; | |
3f9b14ff | 1115 | bitmap_set_bit (&live->livein[add_block->index], p); |
6de9cd9a DN |
1116 | } |
1117 | } | |
6de9cd9a | 1118 | |
32ace6e2 AM |
1119 | /* If SSA_NAME is live on entry to at least one block, fill in all the live |
1120 | on entry blocks between the def and all the uses. */ | |
1121 | if (global) | |
1122 | bitmap_set_bit (live->global, p); | |
6de9cd9a DN |
1123 | } |
1124 | ||
1125 | ||
1126 | /* Calculate the live on exit vectors based on the entry info in LIVEINFO. */ | |
1127 | ||
1128 | void | |
1129 | calculate_live_on_exit (tree_live_info_p liveinfo) | |
1130 | { | |
6de9cd9a DN |
1131 | basic_block bb; |
1132 | edge e; | |
32ace6e2 | 1133 | edge_iterator ei; |
6de9cd9a | 1134 | |
7290d709 | 1135 | /* live on entry calculations used liveout vectors for defs, clear them. */ |
32ace6e2 | 1136 | FOR_EACH_BB (bb) |
3f9b14ff | 1137 | bitmap_clear (&liveinfo->liveout[bb->index]); |
6de9cd9a DN |
1138 | |
1139 | /* Set all the live-on-exit bits for uses in PHIs. */ | |
1140 | FOR_EACH_BB (bb) | |
1141 | { | |
726a989a RB |
1142 | gimple_stmt_iterator gsi; |
1143 | size_t i; | |
1144 | ||
32ace6e2 | 1145 | /* Mark the PHI arguments which are live on exit to the pred block. */ |
726a989a RB |
1146 | for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
1147 | { | |
1148 | gimple phi = gsi_stmt (gsi); | |
1149 | for (i = 0; i < gimple_phi_num_args (phi); i++) | |
b8698a0f | 1150 | { |
726a989a RB |
1151 | tree t = PHI_ARG_DEF (phi, i); |
1152 | int p; | |
1153 | ||
1154 | if (TREE_CODE (t) != SSA_NAME) | |
1155 | continue; | |
1156 | ||
1157 | p = var_to_partition (liveinfo->map, t); | |
1158 | if (p == NO_PARTITION) | |
1159 | continue; | |
1160 | e = gimple_phi_arg_edge (phi, i); | |
1161 | if (e->src != ENTRY_BLOCK_PTR) | |
3f9b14ff | 1162 | bitmap_set_bit (&liveinfo->liveout[e->src->index], p); |
726a989a RB |
1163 | } |
1164 | } | |
32ace6e2 | 1165 | |
7290d709 | 1166 | /* Add each successors live on entry to this bock live on exit. */ |
32ace6e2 AM |
1167 | FOR_EACH_EDGE (e, ei, bb->succs) |
1168 | if (e->dest != EXIT_BLOCK_PTR) | |
3f9b14ff | 1169 | bitmap_ior_into (&liveinfo->liveout[bb->index], |
32ace6e2 | 1170 | live_on_entry (liveinfo, e->dest)); |
6de9cd9a | 1171 | } |
32ace6e2 AM |
1172 | } |
1173 | ||
7290d709 | 1174 | |
b8698a0f | 1175 | /* Given partition map MAP, calculate all the live on entry bitmaps for |
32ace6e2 AM |
1176 | each partition. Return a new live info object. */ |
1177 | ||
b8698a0f | 1178 | tree_live_info_p |
32ace6e2 AM |
1179 | calculate_live_ranges (var_map map) |
1180 | { | |
1181 | tree var; | |
1182 | unsigned i; | |
1183 | tree_live_info_p live; | |
6de9cd9a | 1184 | |
3f9b14ff | 1185 | bitmap_obstack_initialize (&liveness_bitmap_obstack); |
32ace6e2 | 1186 | live = new_tree_live_info (map); |
6de9cd9a DN |
1187 | for (i = 0; i < num_var_partitions (map); i++) |
1188 | { | |
32ace6e2 AM |
1189 | var = partition_to_var (map, i); |
1190 | if (var != NULL_TREE) | |
1191 | set_var_live_on_entry (var, live); | |
6de9cd9a DN |
1192 | } |
1193 | ||
32ace6e2 AM |
1194 | live_worklist (live); |
1195 | ||
1196 | #ifdef ENABLE_CHECKING | |
1197 | verify_live_on_entry (live); | |
1198 | #endif | |
1199 | ||
1200 | calculate_live_on_exit (live); | |
1201 | return live; | |
6de9cd9a DN |
1202 | } |
1203 | ||
1204 | ||
6de9cd9a DN |
1205 | /* Output partition map MAP to file F. */ |
1206 | ||
1207 | void | |
1208 | dump_var_map (FILE *f, var_map map) | |
1209 | { | |
1210 | int t; | |
1211 | unsigned x, y; | |
1212 | int p; | |
1213 | ||
1214 | fprintf (f, "\nPartition map \n\n"); | |
1215 | ||
1216 | for (x = 0; x < map->num_partitions; x++) | |
1217 | { | |
7290d709 AM |
1218 | if (map->view_to_partition != NULL) |
1219 | p = map->view_to_partition[x]; | |
6de9cd9a DN |
1220 | else |
1221 | p = x; | |
1222 | ||
12fdc099 SB |
1223 | if (ssa_name (p) == NULL_TREE |
1224 | || virtual_operand_p (ssa_name (p))) | |
6de9cd9a DN |
1225 | continue; |
1226 | ||
1227 | t = 0; | |
95a3742c | 1228 | for (y = 1; y < num_ssa_names; y++) |
6de9cd9a DN |
1229 | { |
1230 | p = partition_find (map->var_partition, y); | |
7290d709 AM |
1231 | if (map->partition_to_view) |
1232 | p = map->partition_to_view[p]; | |
6de9cd9a DN |
1233 | if (p == (int)x) |
1234 | { | |
1235 | if (t++ == 0) | |
1236 | { | |
1237 | fprintf(f, "Partition %d (", x); | |
1238 | print_generic_expr (f, partition_to_var (map, p), TDF_SLIM); | |
1239 | fprintf (f, " - "); | |
1240 | } | |
1241 | fprintf (f, "%d ", y); | |
1242 | } | |
1243 | } | |
1244 | if (t != 0) | |
1245 | fprintf (f, ")\n"); | |
1246 | } | |
1247 | fprintf (f, "\n"); | |
1248 | } | |
1249 | ||
1250 | ||
7b3b6ae4 LC |
1251 | /* Generic dump for the above. */ |
1252 | ||
1253 | DEBUG_FUNCTION void | |
1254 | debug (_var_map &ref) | |
1255 | { | |
1256 | dump_var_map (stderr, &ref); | |
1257 | } | |
1258 | ||
1259 | DEBUG_FUNCTION void | |
1260 | debug (_var_map *ptr) | |
1261 | { | |
1262 | if (ptr) | |
1263 | debug (*ptr); | |
1264 | else | |
1265 | fprintf (stderr, "<nil>\n"); | |
1266 | } | |
1267 | ||
1268 | ||
6de9cd9a DN |
1269 | /* Output live range info LIVE to file F, controlled by FLAG. */ |
1270 | ||
1271 | void | |
1272 | dump_live_info (FILE *f, tree_live_info_p live, int flag) | |
1273 | { | |
1274 | basic_block bb; | |
3cd8c58a | 1275 | unsigned i; |
6de9cd9a | 1276 | var_map map = live->map; |
87c476a2 | 1277 | bitmap_iterator bi; |
6de9cd9a DN |
1278 | |
1279 | if ((flag & LIVEDUMP_ENTRY) && live->livein) | |
1280 | { | |
1281 | FOR_EACH_BB (bb) | |
1282 | { | |
1283 | fprintf (f, "\nLive on entry to BB%d : ", bb->index); | |
3f9b14ff | 1284 | EXECUTE_IF_SET_IN_BITMAP (&live->livein[bb->index], 0, i, bi) |
6de9cd9a | 1285 | { |
32ace6e2 AM |
1286 | print_generic_expr (f, partition_to_var (map, i), TDF_SLIM); |
1287 | fprintf (f, " "); | |
6de9cd9a DN |
1288 | } |
1289 | fprintf (f, "\n"); | |
1290 | } | |
1291 | } | |
1292 | ||
1293 | if ((flag & LIVEDUMP_EXIT) && live->liveout) | |
1294 | { | |
1295 | FOR_EACH_BB (bb) | |
1296 | { | |
1297 | fprintf (f, "\nLive on exit from BB%d : ", bb->index); | |
3f9b14ff | 1298 | EXECUTE_IF_SET_IN_BITMAP (&live->liveout[bb->index], 0, i, bi) |
6de9cd9a DN |
1299 | { |
1300 | print_generic_expr (f, partition_to_var (map, i), TDF_SLIM); | |
1301 | fprintf (f, " "); | |
87c476a2 | 1302 | } |
6de9cd9a DN |
1303 | fprintf (f, "\n"); |
1304 | } | |
1305 | } | |
1306 | } | |
1e128c5f | 1307 | |
7b3b6ae4 LC |
1308 | |
1309 | /* Generic dump for the above. */ | |
1310 | ||
1311 | DEBUG_FUNCTION void | |
1312 | debug (tree_live_info_d &ref) | |
1313 | { | |
1314 | dump_live_info (stderr, &ref, 0); | |
1315 | } | |
1316 | ||
1317 | DEBUG_FUNCTION void | |
1318 | debug (tree_live_info_d *ptr) | |
1319 | { | |
1320 | if (ptr) | |
1321 | debug (*ptr); | |
1322 | else | |
1323 | fprintf (stderr, "<nil>\n"); | |
1324 | } | |
1325 | ||
1326 | ||
1e128c5f | 1327 | #ifdef ENABLE_CHECKING |
7290d709 AM |
1328 | /* Verify that SSA_VAR is a non-virtual SSA_NAME. */ |
1329 | ||
1e128c5f GB |
1330 | void |
1331 | register_ssa_partition_check (tree ssa_var) | |
1332 | { | |
1333 | gcc_assert (TREE_CODE (ssa_var) == SSA_NAME); | |
ea057359 | 1334 | if (virtual_operand_p (ssa_var)) |
1e128c5f GB |
1335 | { |
1336 | fprintf (stderr, "Illegally registering a virtual SSA name :"); | |
1337 | print_generic_expr (stderr, ssa_var, TDF_SLIM); | |
1338 | fprintf (stderr, " in the SSA->Normal phase.\n"); | |
1339 | internal_error ("SSA corruption"); | |
1340 | } | |
1341 | } | |
32ace6e2 AM |
1342 | |
1343 | ||
1344 | /* Verify that the info in LIVE matches the current cfg. */ | |
7290d709 | 1345 | |
32ace6e2 AM |
1346 | static void |
1347 | verify_live_on_entry (tree_live_info_p live) | |
1348 | { | |
1349 | unsigned i; | |
1350 | tree var; | |
726a989a | 1351 | gimple stmt; |
32ace6e2 AM |
1352 | basic_block bb; |
1353 | edge e; | |
1354 | int num; | |
1355 | edge_iterator ei; | |
1356 | var_map map = live->map; | |
1357 | ||
1358 | /* Check for live on entry partitions and report those with a DEF in | |
1359 | the program. This will typically mean an optimization has done | |
1360 | something wrong. */ | |
32ace6e2 AM |
1361 | bb = ENTRY_BLOCK_PTR; |
1362 | num = 0; | |
1363 | FOR_EACH_EDGE (e, ei, bb->succs) | |
1364 | { | |
1365 | int entry_block = e->dest->index; | |
1366 | if (e->dest == EXIT_BLOCK_PTR) | |
1367 | continue; | |
1368 | for (i = 0; i < (unsigned)num_var_partitions (map); i++) | |
1369 | { | |
1370 | basic_block tmp; | |
70b5e7dc | 1371 | tree d = NULL_TREE; |
32ace6e2 AM |
1372 | bitmap loe; |
1373 | var = partition_to_var (map, i); | |
1374 | stmt = SSA_NAME_DEF_STMT (var); | |
726a989a | 1375 | tmp = gimple_bb (stmt); |
70b5e7dc RG |
1376 | if (SSA_NAME_VAR (var)) |
1377 | d = ssa_default_def (cfun, SSA_NAME_VAR (var)); | |
32ace6e2 AM |
1378 | |
1379 | loe = live_on_entry (live, e->dest); | |
1380 | if (loe && bitmap_bit_p (loe, i)) | |
1381 | { | |
726a989a | 1382 | if (!gimple_nop_p (stmt)) |
32ace6e2 AM |
1383 | { |
1384 | num++; | |
1385 | print_generic_expr (stderr, var, TDF_SLIM); | |
1386 | fprintf (stderr, " is defined "); | |
1387 | if (tmp) | |
1388 | fprintf (stderr, " in BB%d, ", tmp->index); | |
1389 | fprintf (stderr, "by:\n"); | |
726a989a | 1390 | print_gimple_stmt (stderr, stmt, 0, TDF_SLIM); |
b8698a0f | 1391 | fprintf (stderr, "\nIt is also live-on-entry to entry BB %d", |
32ace6e2 AM |
1392 | entry_block); |
1393 | fprintf (stderr, " So it appears to have multiple defs.\n"); | |
1394 | } | |
1395 | else | |
1396 | { | |
1397 | if (d != var) | |
1398 | { | |
1399 | num++; | |
1400 | print_generic_expr (stderr, var, TDF_SLIM); | |
726a989a RB |
1401 | fprintf (stderr, " is live-on-entry to BB%d ", |
1402 | entry_block); | |
32ace6e2 AM |
1403 | if (d) |
1404 | { | |
1405 | fprintf (stderr, " but is not the default def of "); | |
1406 | print_generic_expr (stderr, d, TDF_SLIM); | |
1407 | fprintf (stderr, "\n"); | |
1408 | } | |
1409 | else | |
1410 | fprintf (stderr, " and there is no default def.\n"); | |
1411 | } | |
1412 | } | |
1413 | } | |
1414 | else | |
1415 | if (d == var) | |
1416 | { | |
b8698a0f | 1417 | /* The only way this var shouldn't be marked live on entry is |
32ace6e2 | 1418 | if it occurs in a PHI argument of the block. */ |
726a989a RB |
1419 | size_t z; |
1420 | bool ok = false; | |
1421 | gimple_stmt_iterator gsi; | |
1422 | for (gsi = gsi_start_phis (e->dest); | |
1423 | !gsi_end_p (gsi) && !ok; | |
1424 | gsi_next (&gsi)) | |
32ace6e2 | 1425 | { |
726a989a RB |
1426 | gimple phi = gsi_stmt (gsi); |
1427 | for (z = 0; z < gimple_phi_num_args (phi); z++) | |
1428 | if (var == gimple_phi_arg_def (phi, z)) | |
32ace6e2 | 1429 | { |
726a989a | 1430 | ok = true; |
32ace6e2 AM |
1431 | break; |
1432 | } | |
1433 | } | |
1434 | if (ok) | |
1435 | continue; | |
1436 | num++; | |
1437 | print_generic_expr (stderr, var, TDF_SLIM); | |
b8698a0f | 1438 | fprintf (stderr, " is not marked live-on-entry to entry BB%d ", |
32ace6e2 AM |
1439 | entry_block); |
1440 | fprintf (stderr, "but it is a default def so it should be.\n"); | |
1441 | } | |
1442 | } | |
1443 | } | |
1444 | gcc_assert (num <= 0); | |
1445 | } | |
1e128c5f | 1446 | #endif |