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1 : : /* Liveness for SSA trees.
2 : : Copyright (C) 2003-2024 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 3, 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 COPYING3. If not see
19 : : <http://www.gnu.org/licenses/>. */
20 : :
21 : : #include "config.h"
22 : : #include "system.h"
23 : : #include "coretypes.h"
24 : : #include "backend.h"
25 : : #include "rtl.h"
26 : : #include "tree.h"
27 : : #include "gimple.h"
28 : : #include "timevar.h"
29 : : #include "ssa.h"
30 : : #include "cgraph.h"
31 : : #include "gimple-pretty-print.h"
32 : : #include "diagnostic-core.h"
33 : : #include "gimple-iterator.h"
34 : : #include "tree-dfa.h"
35 : : #include "dumpfile.h"
36 : : #include "tree-ssa-live.h"
37 : : #include "debug.h"
38 : : #include "tree-ssa.h"
39 : : #include "ipa-utils.h"
40 : : #include "cfgloop.h"
41 : : #include "stringpool.h"
42 : : #include "attribs.h"
43 : : #include "optinfo.h"
44 : : #include "gimple-walk.h"
45 : : #include "cfganal.h"
46 : : #include "tree-cfg.h"
47 : :
48 : : static void verify_live_on_entry (tree_live_info_p);
49 : :
50 : :
51 : : /* VARMAP maintains a mapping from SSA version number to real variables.
52 : :
53 : : All SSA_NAMES are divided into partitions. Initially each ssa_name is the
54 : : only member of it's own partition. Coalescing will attempt to group any
55 : : ssa_names which occur in a copy or in a PHI node into the same partition.
56 : :
57 : : At the end of out-of-ssa, each partition becomes a "real" variable and is
58 : : rewritten as a compiler variable.
59 : :
60 : : The var_map data structure is used to manage these partitions. It allows
61 : : partitions to be combined, and determines which partition belongs to what
62 : : ssa_name or variable, and vice versa. */
63 : :
64 : :
65 : : /* Remove the base table in MAP. */
66 : :
67 : : static void
68 : 4299969 : var_map_base_fini (var_map map)
69 : : {
70 : : /* Free the basevar info if it is present. */
71 : 4299969 : if (map->partition_to_base_index != NULL)
72 : : {
73 : 1433323 : free (map->partition_to_base_index);
74 : 1433323 : map->partition_to_base_index = NULL;
75 : 1433323 : map->num_basevars = 0;
76 : : }
77 : 4299969 : }
78 : : /* Create a variable partition map of SIZE for region, initialize and return
79 : : it. Region is a loop if LOOP is non-NULL, otherwise is the current
80 : : function. If BITINT is non-NULL, only SSA_NAMEs from that bitmap
81 : : will be coalesced. */
82 : :
83 : : var_map
84 : 1433323 : init_var_map (int size, class loop *loop, bitmap bitint)
85 : : {
86 : 1433323 : var_map map;
87 : :
88 : 1433323 : map = (var_map) xmalloc (sizeof (struct _var_map));
89 : 1433323 : map->var_partition = partition_new (size);
90 : :
91 : 1433323 : map->partition_to_view = NULL;
92 : 1433323 : map->view_to_partition = NULL;
93 : 1433323 : map->num_partitions = size;
94 : 1433323 : map->partition_size = size;
95 : 1433323 : map->num_basevars = 0;
96 : 1433323 : map->partition_to_base_index = NULL;
97 : 1433323 : map->vec_bbs = vNULL;
98 : 1433323 : if (loop)
99 : : {
100 : 0 : map->bmp_bbs = BITMAP_ALLOC (NULL);
101 : 0 : map->outofssa_p = false;
102 : 0 : basic_block *bbs = get_loop_body_in_dom_order (loop);
103 : 0 : for (unsigned i = 0; i < loop->num_nodes; ++i)
104 : : {
105 : 0 : bitmap_set_bit (map->bmp_bbs, bbs[i]->index);
106 : 0 : map->vec_bbs.safe_push (bbs[i]);
107 : : }
108 : 0 : free (bbs);
109 : : }
110 : : else
111 : : {
112 : 1433323 : map->bmp_bbs = NULL;
113 : 1433323 : map->outofssa_p = bitint == NULL;
114 : 1433323 : map->bitint = bitint;
115 : 1433323 : basic_block bb;
116 : 2866646 : map->vec_bbs.reserve_exact (n_basic_blocks_for_fn (cfun)
117 : 1433323 : - NUM_FIXED_BLOCKS);
118 : 13340578 : FOR_EACH_BB_FN (bb, cfun)
119 : 11907255 : map->vec_bbs.quick_push (bb);
120 : : }
121 : 1433323 : return map;
122 : : }
123 : :
124 : :
125 : : /* Free memory associated with MAP. */
126 : :
127 : : void
128 : 1433323 : delete_var_map (var_map map)
129 : : {
130 : 1433323 : var_map_base_fini (map);
131 : 1433323 : partition_delete (map->var_partition);
132 : 1433323 : free (map->partition_to_view);
133 : 1433323 : free (map->view_to_partition);
134 : 1433323 : if (map->bmp_bbs)
135 : 0 : BITMAP_FREE (map->bmp_bbs);
136 : 1433323 : map->vec_bbs.release ();
137 : 1433323 : free (map);
138 : 1433323 : }
139 : :
140 : :
141 : : /* This function will combine the partitions in MAP for VAR1 and VAR2. It
142 : : Returns the partition which represents the new partition. If the two
143 : : partitions cannot be combined, NO_PARTITION is returned. */
144 : :
145 : : int
146 : 5027800 : var_union (var_map map, tree var1, tree var2)
147 : : {
148 : 5027800 : int p1, p2, p3;
149 : :
150 : 5027800 : gcc_assert (TREE_CODE (var1) == SSA_NAME);
151 : 5027800 : gcc_assert (TREE_CODE (var2) == SSA_NAME);
152 : :
153 : : /* This is independent of partition_to_view. If partition_to_view is
154 : : on, then whichever one of these partitions is absorbed will never have a
155 : : dereference into the partition_to_view array any more. */
156 : :
157 : 5027800 : p1 = partition_find (map->var_partition, SSA_NAME_VERSION (var1));
158 : 5027800 : p2 = partition_find (map->var_partition, SSA_NAME_VERSION (var2));
159 : :
160 : 5027800 : gcc_assert (p1 != NO_PARTITION);
161 : 5027800 : gcc_assert (p2 != NO_PARTITION);
162 : :
163 : 5027800 : if (p1 == p2)
164 : : p3 = p1;
165 : : else
166 : 5027800 : p3 = partition_union (map->var_partition, p1, p2);
167 : :
168 : 5027800 : if (map->partition_to_view)
169 : 5027800 : p3 = map->partition_to_view[p3];
170 : :
171 : 5027800 : return p3;
172 : : }
173 : :
174 : :
175 : : /* Compress the partition numbers in MAP such that they fall in the range
176 : : 0..(num_partitions-1) instead of wherever they turned out during
177 : : the partitioning exercise. This removes any references to unused
178 : : partitions, thereby allowing bitmaps and other vectors to be much
179 : : denser.
180 : :
181 : : This is implemented such that compaction doesn't affect partitioning.
182 : : Ie., once partitions are created and possibly merged, running one
183 : : or more different kind of compaction will not affect the partitions
184 : : themselves. Their index might change, but all the same variables will
185 : : still be members of the same partition group. This allows work on reduced
186 : : sets, and no loss of information when a larger set is later desired.
187 : :
188 : : In particular, coalescing can work on partitions which have 2 or more
189 : : definitions, and then 'recompact' later to include all the single
190 : : definitions for assignment to program variables. */
191 : :
192 : :
193 : : /* Set MAP back to the initial state of having no partition view. Return a
194 : : bitmap which has a bit set for each partition number which is in use in the
195 : : varmap. */
196 : :
197 : : static bitmap
198 : 2866646 : partition_view_init (var_map map)
199 : : {
200 : 2866646 : bitmap used;
201 : 2866646 : int tmp;
202 : 2866646 : unsigned int x;
203 : :
204 : 2866646 : used = BITMAP_ALLOC (NULL);
205 : :
206 : : /* Already in a view? Abandon the old one. */
207 : 2866646 : if (map->partition_to_view)
208 : : {
209 : 1433323 : free (map->partition_to_view);
210 : 1433323 : map->partition_to_view = NULL;
211 : : }
212 : 2866646 : if (map->view_to_partition)
213 : : {
214 : 1433323 : free (map->view_to_partition);
215 : 1433323 : map->view_to_partition = NULL;
216 : : }
217 : :
218 : : /* Find out which partitions are actually referenced. */
219 : 138392698 : for (x = 0; x < map->partition_size; x++)
220 : : {
221 : 135526052 : tmp = partition_find (map->var_partition, x);
222 : 320745048 : if (ssa_name (tmp) != NULL_TREE && !virtual_operand_p (ssa_name (tmp))
223 : 195648570 : && (!has_zero_uses (ssa_name (tmp))
224 : 4008216 : || !SSA_NAME_IS_DEFAULT_DEF (ssa_name (tmp))
225 : 3446114 : || (SSA_NAME_VAR (ssa_name (tmp))
226 : 3446114 : && !VAR_P (SSA_NAME_VAR (ssa_name (tmp))))))
227 : 59625254 : bitmap_set_bit (used, tmp);
228 : : }
229 : :
230 : 2866646 : map->num_partitions = map->partition_size;
231 : 2866646 : return used;
232 : : }
233 : :
234 : :
235 : : /* This routine will finalize the view data for MAP based on the partitions
236 : : set in SELECTED. This is either the same bitmap returned from
237 : : partition_view_init, or a trimmed down version if some of those partitions
238 : : were not desired in this view. SELECTED is freed before returning. */
239 : :
240 : : static void
241 : 2866646 : partition_view_fini (var_map map, bitmap selected)
242 : : {
243 : 2866646 : bitmap_iterator bi;
244 : 2866646 : unsigned count, i, x, limit;
245 : :
246 : 2866646 : gcc_assert (selected);
247 : :
248 : 2866646 : count = bitmap_count_bits (selected);
249 : 2866646 : limit = map->partition_size;
250 : :
251 : : /* If its a one-to-one ratio, we don't need any view compaction. */
252 : 2866646 : if (count < limit)
253 : : {
254 : 2866646 : map->partition_to_view = (int *)xmalloc (limit * sizeof (int));
255 : 2866646 : memset (map->partition_to_view, 0xff, (limit * sizeof (int)));
256 : 2866646 : map->view_to_partition = (int *)xmalloc (count * sizeof (int));
257 : :
258 : 2866646 : i = 0;
259 : : /* Give each selected partition an index. */
260 : 38346153 : EXECUTE_IF_SET_IN_BITMAP (selected, 0, x, bi)
261 : : {
262 : 35479507 : map->partition_to_view[x] = i;
263 : 35479507 : map->view_to_partition[i] = x;
264 : 35479507 : i++;
265 : : }
266 : 2866646 : gcc_assert (i == count);
267 : 2866646 : map->num_partitions = i;
268 : : }
269 : :
270 : 2866646 : BITMAP_FREE (selected);
271 : 2866646 : }
272 : :
273 : :
274 : : /* Create a partition view which includes all the used partitions in MAP. */
275 : :
276 : : void
277 : 1433323 : partition_view_normal (var_map map)
278 : : {
279 : 1433323 : bitmap used;
280 : :
281 : 1433323 : used = partition_view_init (map);
282 : 1433323 : partition_view_fini (map, used);
283 : :
284 : 1433323 : var_map_base_fini (map);
285 : 1433323 : }
286 : :
287 : :
288 : : /* Create a partition view in MAP which includes just partitions which occur in
289 : : the bitmap ONLY. If WANT_BASES is true, create the base variable map
290 : : as well. */
291 : :
292 : : void
293 : 1433323 : partition_view_bitmap (var_map map, bitmap only)
294 : : {
295 : 1433323 : bitmap used;
296 : 1433323 : bitmap new_partitions = BITMAP_ALLOC (NULL);
297 : 1433323 : unsigned x, p;
298 : 1433323 : bitmap_iterator bi;
299 : :
300 : 1433323 : used = partition_view_init (map);
301 : 12128003 : EXECUTE_IF_SET_IN_BITMAP (only, 0, x, bi)
302 : : {
303 : 10694680 : p = partition_find (map->var_partition, x);
304 : 10694680 : gcc_assert (bitmap_bit_p (used, p));
305 : 10694680 : bitmap_set_bit (new_partitions, p);
306 : : }
307 : 1433323 : partition_view_fini (map, new_partitions);
308 : :
309 : 1433323 : var_map_base_fini (map);
310 : 1433323 : }
311 : :
312 : :
313 : : static bitmap usedvars;
314 : :
315 : : /* Mark VAR as used, so that it'll be preserved during rtl expansion.
316 : : Returns true if VAR wasn't marked before. */
317 : :
318 : : static inline bool
319 : 169251759 : set_is_used (tree var)
320 : : {
321 : 169251759 : return bitmap_set_bit (usedvars, DECL_UID (var));
322 : : }
323 : :
324 : : /* Return true if VAR is marked as used. */
325 : :
326 : : static inline bool
327 : 168301555 : is_used_p (tree var)
328 : : {
329 : 168301555 : return bitmap_bit_p (usedvars, DECL_UID (var));
330 : : }
331 : :
332 : : static inline void mark_all_vars_used (tree *);
333 : :
334 : : /* Helper function for mark_all_vars_used, called via walk_tree. */
335 : :
336 : : static tree
337 : 989647257 : mark_all_vars_used_1 (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
338 : : {
339 : 989647257 : tree t = *tp;
340 : 989647257 : enum tree_code_class c = TREE_CODE_CLASS (TREE_CODE (t));
341 : 989647257 : tree b;
342 : :
343 : 989647257 : if (TREE_CODE (t) == SSA_NAME)
344 : : {
345 : 373990864 : *walk_subtrees = 0;
346 : 373990864 : t = SSA_NAME_VAR (t);
347 : : if (!t)
348 : : return NULL;
349 : : }
350 : :
351 : 739161683 : if (IS_EXPR_CODE_CLASS (c)
352 : 739161683 : && (b = TREE_BLOCK (t)) != NULL)
353 : 67386897 : TREE_USED (b) = true;
354 : :
355 : : /* Ignore TMR_OFFSET and TMR_STEP for TARGET_MEM_REFS, as those
356 : : fields do not contain vars. */
357 : 739161683 : if (TREE_CODE (t) == TARGET_MEM_REF)
358 : : {
359 : 1540549 : mark_all_vars_used (&TMR_BASE (t));
360 : 1540549 : mark_all_vars_used (&TMR_INDEX (t));
361 : 1540549 : mark_all_vars_used (&TMR_INDEX2 (t));
362 : 1540549 : *walk_subtrees = 0;
363 : 1540549 : return NULL;
364 : : }
365 : :
366 : : /* Only need to mark VAR_DECLS; parameters and return results are not
367 : : eliminated as unused. */
368 : 737621134 : if (VAR_P (t))
369 : : {
370 : : /* When a global var becomes used for the first time also walk its
371 : : initializer (non global ones don't have any). */
372 : 208470436 : if (set_is_used (t) && is_global_var (t)
373 : 176114101 : && DECL_CONTEXT (t) == current_function_decl)
374 : 1030385 : mark_all_vars_used (&DECL_INITIAL (t));
375 : : }
376 : : /* remove_unused_scope_block_p requires information about labels
377 : : which are not DECL_IGNORED_P to tell if they might be used in the IL. */
378 : 568369375 : else if (TREE_CODE (t) == LABEL_DECL)
379 : : /* Although the TREE_USED values that the frontend uses would be
380 : : acceptable (albeit slightly over-conservative) for our purposes,
381 : : init_vars_expansion clears TREE_USED for LABEL_DECLs too, so we
382 : : must re-compute it here. */
383 : 5972003 : TREE_USED (t) = 1;
384 : :
385 : 737621134 : if (IS_TYPE_OR_DECL_P (t))
386 : 336142978 : *walk_subtrees = 0;
387 : :
388 : : return NULL;
389 : : }
390 : :
391 : : /* Mark the scope block SCOPE and its subblocks unused when they can be
392 : : possibly eliminated if dead. */
393 : :
394 : : static void
395 : 104334650 : mark_scope_block_unused (tree scope)
396 : : {
397 : 104334650 : tree t;
398 : 104334650 : TREE_USED (scope) = false;
399 : 104334650 : if (!(*debug_hooks->ignore_block) (scope))
400 : 316942 : TREE_USED (scope) = true;
401 : 197885768 : for (t = BLOCK_SUBBLOCKS (scope); t ; t = BLOCK_CHAIN (t))
402 : 93551118 : mark_scope_block_unused (t);
403 : 104334650 : }
404 : :
405 : : /* Look if the block is dead (by possibly eliminating its dead subblocks)
406 : : and return true if so.
407 : : Block is declared dead if:
408 : : 1) No statements are associated with it.
409 : : 2) Declares no live variables
410 : : 3) All subblocks are dead
411 : : or there is precisely one subblocks and the block
412 : : has same abstract origin as outer block and declares
413 : : no variables, so it is pure wrapper.
414 : : When we are not outputting full debug info, we also eliminate dead variables
415 : : out of scope blocks to let them to be recycled by GGC and to save copying work
416 : : done by the inliner. */
417 : :
418 : : static bool
419 : 104334650 : remove_unused_scope_block_p (tree scope, bool in_ctor_dtor_block)
420 : : {
421 : 104334650 : tree *t, *next;
422 : 104334650 : bool unused = !TREE_USED (scope);
423 : 104334650 : int nsubblocks = 0;
424 : :
425 : : /* For ipa-polymorphic-call.cc purposes, preserve blocks:
426 : : 1) with BLOCK_ABSTRACT_ORIGIN of a ctor/dtor or their clones */
427 : 104334650 : if (inlined_polymorphic_ctor_dtor_block_p (scope, true))
428 : : {
429 : : in_ctor_dtor_block = true;
430 : : unused = false;
431 : : }
432 : : /* 2) inside such blocks, the outermost block with block_ultimate_origin
433 : : being a FUNCTION_DECL. */
434 : 88648813 : else if (in_ctor_dtor_block)
435 : : {
436 : 14006985 : tree fn = block_ultimate_origin (scope);
437 : 14006985 : if (fn && TREE_CODE (fn) == FUNCTION_DECL)
438 : : {
439 : 104334650 : in_ctor_dtor_block = false;
440 : 104334650 : unused = false;
441 : : }
442 : : }
443 : :
444 : 203727210 : for (t = &BLOCK_VARS (scope); *t; t = next)
445 : : {
446 : 99392560 : next = &DECL_CHAIN (*t);
447 : :
448 : : /* Debug info of nested function refers to the block of the
449 : : function. We might stil call it even if all statements
450 : : of function it was nested into was elliminated.
451 : :
452 : : TODO: We can actually look into cgraph to see if function
453 : : will be output to file. */
454 : 99392560 : if (TREE_CODE (*t) == FUNCTION_DECL)
455 : : unused = false;
456 : :
457 : : /* If a decl has a value expr, we need to instantiate it
458 : : regardless of debug info generation, to avoid codegen
459 : : differences in memory overlap tests. update_equiv_regs() may
460 : : indirectly call validate_equiv_mem() to test whether a
461 : : SET_DEST overlaps with others, and if the value expr changes
462 : : by virtual register instantiation, we may get end up with
463 : : different results. */
464 : 99064488 : else if (VAR_P (*t) && DECL_HAS_VALUE_EXPR_P (*t))
465 : : unused = false;
466 : :
467 : : /* Remove everything we don't generate debug info for. */
468 : 97850468 : else if (DECL_IGNORED_P (*t))
469 : : {
470 : 3677859 : *t = DECL_CHAIN (*t);
471 : 3677859 : next = t;
472 : : }
473 : :
474 : : /* When we are outputting debug info, we usually want to output
475 : : info about optimized-out variables in the scope blocks.
476 : : Exception are the scope blocks not containing any instructions
477 : : at all so user can't get into the scopes at first place. */
478 : 94172609 : else if (is_used_p (*t))
479 : : unused = false;
480 : 81093226 : else if (TREE_CODE (*t) == LABEL_DECL && TREE_USED (*t))
481 : : /* For labels that are still used in the IL, the decision to
482 : : preserve them must not depend DEBUG_INFO_LEVEL, otherwise we
483 : : risk having different ordering in debug vs. non-debug builds
484 : : during inlining or versioning.
485 : : A label appearing here (we have already checked DECL_IGNORED_P)
486 : : should not be used in the IL unless it has been explicitly used
487 : : before, so we use TREE_USED as an approximation. */
488 : : /* In principle, we should do the same here as for the debug case
489 : : below, however, when debugging, there might be additional nested
490 : : levels that keep an upper level with a label live, so we have to
491 : : force this block to be considered used, too. */
492 : : unused = false;
493 : :
494 : : /* When we are not doing full debug info, we however can keep around
495 : : only the used variables for cfgexpand's memory packing saving quite
496 : : a lot of memory.
497 : :
498 : : For sake of -g3, we keep around those vars but we don't count this as
499 : : use of block, so innermost block with no used vars and no instructions
500 : : can be considered dead. We only want to keep around blocks user can
501 : : breakpoint into and ask about value of optimized out variables.
502 : :
503 : : Similarly we need to keep around types at least until all
504 : : variables of all nested blocks are gone. We track no
505 : : information on whether given type is used or not, so we have
506 : : to keep them even when not emitting debug information,
507 : : otherwise we may end up remapping variables and their (local)
508 : : types in different orders depending on whether debug
509 : : information is being generated. */
510 : :
511 : 80524286 : else if (TREE_CODE (*t) == TYPE_DECL
512 : 76925402 : || debug_info_level == DINFO_LEVEL_NORMAL
513 : 2146751 : || debug_info_level == DINFO_LEVEL_VERBOSE)
514 : : ;
515 : : else
516 : : {
517 : 2137536 : *t = DECL_CHAIN (*t);
518 : 2137536 : next = t;
519 : : }
520 : : }
521 : :
522 : 197885768 : for (t = &BLOCK_SUBBLOCKS (scope); *t ;)
523 : 93551118 : if (remove_unused_scope_block_p (*t, in_ctor_dtor_block))
524 : : {
525 : 7385079 : if (BLOCK_SUBBLOCKS (*t))
526 : : {
527 : 2424654 : tree next = BLOCK_CHAIN (*t);
528 : 2424654 : tree supercontext = BLOCK_SUPERCONTEXT (*t);
529 : :
530 : 2424654 : *t = BLOCK_SUBBLOCKS (*t);
531 : 2973694 : while (BLOCK_CHAIN (*t))
532 : : {
533 : 549040 : BLOCK_SUPERCONTEXT (*t) = supercontext;
534 : 549040 : t = &BLOCK_CHAIN (*t);
535 : : }
536 : 2424654 : BLOCK_CHAIN (*t) = next;
537 : 2424654 : BLOCK_SUPERCONTEXT (*t) = supercontext;
538 : 2424654 : t = &BLOCK_CHAIN (*t);
539 : 2424654 : nsubblocks ++;
540 : : }
541 : : else
542 : 4960425 : *t = BLOCK_CHAIN (*t);
543 : : }
544 : : else
545 : : {
546 : 86166039 : t = &BLOCK_CHAIN (*t);
547 : 86166039 : nsubblocks ++;
548 : : }
549 : :
550 : :
551 : 104334650 : if (!unused)
552 : : ;
553 : : /* Outer scope is always used. */
554 : 21852164 : else if (!BLOCK_SUPERCONTEXT (scope)
555 : 21852164 : || TREE_CODE (BLOCK_SUPERCONTEXT (scope)) == FUNCTION_DECL)
556 : : unused = false;
557 : : /* Innermost blocks with no live variables nor statements can be always
558 : : eliminated. */
559 : 20807397 : else if (!nsubblocks)
560 : : ;
561 : : /* When not generating debug info we can eliminate info on unused
562 : : variables. */
563 : 15846972 : else if (!flag_auto_profile
564 : 15846972 : && debug_info_level == DINFO_LEVEL_NONE
565 : 17274230 : && !optinfo_wants_inlining_info_p ())
566 : : {
567 : : /* Even for -g0 don't prune outer scopes from inlined functions,
568 : : otherwise late diagnostics from such functions will not be
569 : : emitted or suppressed properly. */
570 : 1427190 : if (inlined_function_outer_scope_p (scope))
571 : : {
572 : 1214852 : gcc_assert (TREE_CODE (BLOCK_ORIGIN (scope)) == FUNCTION_DECL);
573 : : unused = false;
574 : : }
575 : : }
576 : 14419782 : else if (BLOCK_VARS (scope) || BLOCK_NUM_NONLOCALIZED_VARS (scope))
577 : : unused = false;
578 : : /* See if this block is important for representation of inlined
579 : : function. Inlined functions are always represented by block
580 : : with block_ultimate_origin being set to FUNCTION_DECL and
581 : : DECL_SOURCE_LOCATION set, unless they expand to nothing... */
582 : 2343277 : else if (inlined_function_outer_scope_p (scope))
583 : : unused = false;
584 : : else
585 : : /* Verfify that only blocks with source location set
586 : : are entry points to the inlined functions. */
587 : 2212316 : gcc_assert (LOCATION_LOCUS (BLOCK_SOURCE_LOCATION (scope))
588 : : == UNKNOWN_LOCATION);
589 : :
590 : 104334650 : TREE_USED (scope) = !unused;
591 : 104334650 : return unused;
592 : : }
593 : :
594 : : /* Mark all VAR_DECLS under *EXPR_P as used, so that they won't be
595 : : eliminated during the tree->rtl conversion process. */
596 : :
597 : : static inline void
598 : 739794590 : mark_all_vars_used (tree *expr_p)
599 : : {
600 : 739794590 : walk_tree (expr_p, mark_all_vars_used_1, NULL, NULL);
601 : 739794590 : }
602 : :
603 : : /* Helper function for clear_unused_block_pointer, called via walk_tree. */
604 : :
605 : : static tree
606 : 402400294 : clear_unused_block_pointer_1 (tree *tp, int *, void *)
607 : : {
608 : 67607151 : if (EXPR_P (*tp) && TREE_BLOCK (*tp)
609 : 447380150 : && !TREE_USED (TREE_BLOCK (*tp)))
610 : 988574 : TREE_SET_BLOCK (*tp, NULL);
611 : 402400294 : return NULL_TREE;
612 : : }
613 : :
614 : : /* Clear references to unused BLOCKs from DECL_VALUE_EXPRs of variables
615 : : in BLOCK. */
616 : :
617 : : static void
618 : 96949571 : clear_unused_block_pointer_in_block (tree block)
619 : : {
620 : 187604843 : for (tree t = BLOCK_VARS (block); t; t = DECL_CHAIN (t))
621 : 90655272 : if (VAR_P (t) && DECL_HAS_VALUE_EXPR_P (t))
622 : : {
623 : 1214020 : tree val = DECL_VALUE_EXPR (t);
624 : 1214020 : walk_tree (&val, clear_unused_block_pointer_1, NULL, NULL);
625 : : }
626 : 183115610 : for (tree t = BLOCK_SUBBLOCKS (block); t; t = BLOCK_CHAIN (t))
627 : 86166039 : clear_unused_block_pointer_in_block (t);
628 : 96949571 : }
629 : :
630 : : /* Set all block pointer in debug or clobber stmt to NULL if the block
631 : : is unused, so that they will not be streamed out. */
632 : :
633 : : static void
634 : 10783532 : clear_unused_block_pointer (void)
635 : : {
636 : 10783532 : basic_block bb;
637 : 10783532 : gimple_stmt_iterator gsi;
638 : :
639 : 85144741 : FOR_EACH_BB_FN (bb, cfun)
640 : 641730990 : for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
641 : : {
642 : 494318682 : unsigned i;
643 : 494318682 : tree b;
644 : 494318682 : gimple *stmt;
645 : :
646 : 493010318 : next:
647 : 494318682 : stmt = gsi_stmt (gsi);
648 : 494318682 : if (!is_gimple_debug (stmt) && !gimple_clobber_p (stmt))
649 : 245054712 : continue;
650 : 249263970 : b = gimple_block (stmt);
651 : 249263970 : if (b && !TREE_USED (b))
652 : : {
653 : : /* Elide debug marker stmts that have an associated BLOCK from an
654 : : inline instance removed with also the outermost scope BLOCK of
655 : : said inline instance removed. If the outermost scope BLOCK of
656 : : said inline instance is preserved use that in place of the
657 : : removed BLOCK. That keeps the marker associated to the correct
658 : : inline instance (or no inline instance in case it was not from
659 : : an inline instance). */
660 : 5754302 : if (gimple_debug_nonbind_marker_p (stmt)
661 : 7211456 : && BLOCK_ABSTRACT_ORIGIN (b))
662 : : {
663 : 1816851 : while (TREE_CODE (b) == BLOCK
664 : 1816851 : && !inlined_function_outer_scope_p (b))
665 : 375397 : b = BLOCK_SUPERCONTEXT (b);
666 : 1441454 : if (TREE_CODE (b) == BLOCK)
667 : : {
668 : 1440718 : if (TREE_USED (b))
669 : : {
670 : 130608 : gimple_set_block (stmt, b);
671 : 130608 : continue;
672 : : }
673 : 1310110 : gsi_remove (&gsi, true);
674 : 1310110 : if (gsi_end_p (gsi))
675 : : break;
676 : 1308364 : goto next;
677 : : }
678 : : }
679 : 4313584 : gimple_set_block (stmt, NULL);
680 : : }
681 : 621069166 : for (i = 0; i < gimple_num_ops (stmt); i++)
682 : 373245914 : walk_tree (gimple_op_ptr (stmt, i), clear_unused_block_pointer_1,
683 : : NULL, NULL);
684 : : }
685 : :
686 : : /* Walk all variables mentioned in the functions BLOCK tree and clear
687 : : DECL_VALUE_EXPR from unused blocks where present. */
688 : 10783532 : clear_unused_block_pointer_in_block (DECL_INITIAL (current_function_decl));
689 : 10783532 : }
690 : :
691 : : /* Dump scope blocks starting at SCOPE to FILE. INDENT is the
692 : : indentation level and FLAGS is as in print_generic_expr. */
693 : :
694 : : static void
695 : 4419 : dump_scope_block (FILE *file, int indent, tree scope, dump_flags_t flags)
696 : : {
697 : 4419 : tree var, t;
698 : 4419 : unsigned int i;
699 : :
700 : 4419 : fprintf (file, "\n%*s{ Scope block #%i%s",indent, "" , BLOCK_NUMBER (scope),
701 : 4419 : TREE_USED (scope) ? "" : " (unused)");
702 : 4419 : if (LOCATION_LOCUS (BLOCK_SOURCE_LOCATION (scope)) != UNKNOWN_LOCATION)
703 : : {
704 : 941 : expanded_location s = expand_location (BLOCK_SOURCE_LOCATION (scope));
705 : 941 : fprintf (file, " %s:%i", s.file, s.line);
706 : : }
707 : 4419 : if (BLOCK_ABSTRACT_ORIGIN (scope))
708 : : {
709 : 2050 : tree origin = block_ultimate_origin (scope);
710 : 2050 : if (origin)
711 : : {
712 : 2050 : fprintf (file, " Originating from :");
713 : 2050 : if (DECL_P (origin))
714 : 941 : print_generic_decl (file, origin, flags);
715 : : else
716 : 1109 : fprintf (file, "#%i", BLOCK_NUMBER (origin));
717 : : }
718 : : }
719 : 4419 : if (BLOCK_FRAGMENT_ORIGIN (scope))
720 : 0 : fprintf (file, " Fragment of : #%i",
721 : 0 : BLOCK_NUMBER (BLOCK_FRAGMENT_ORIGIN (scope)));
722 : 4419 : else if (BLOCK_FRAGMENT_CHAIN (scope))
723 : : {
724 : 0 : fprintf (file, " Fragment chain :");
725 : 0 : for (t = BLOCK_FRAGMENT_CHAIN (scope); t ;
726 : 0 : t = BLOCK_FRAGMENT_CHAIN (t))
727 : 0 : fprintf (file, " #%i", BLOCK_NUMBER (t));
728 : : }
729 : 4419 : fprintf (file, " \n");
730 : 8249 : for (var = BLOCK_VARS (scope); var; var = DECL_CHAIN (var))
731 : : {
732 : 3830 : fprintf (file, "%*s", indent, "");
733 : 3830 : print_generic_decl (file, var, flags);
734 : 3830 : fprintf (file, "\n");
735 : : }
736 : 4419 : for (i = 0; i < BLOCK_NUM_NONLOCALIZED_VARS (scope); i++)
737 : : {
738 : 0 : fprintf (file, "%*s",indent, "");
739 : 0 : print_generic_decl (file, BLOCK_NONLOCALIZED_VAR (scope, i),
740 : : flags);
741 : 0 : fprintf (file, " (nonlocalized)\n");
742 : : }
743 : 6852 : for (t = BLOCK_SUBBLOCKS (scope); t ; t = BLOCK_CHAIN (t))
744 : 2433 : dump_scope_block (file, indent + 2, t, flags);
745 : 4419 : fprintf (file, "\n%*s}\n",indent, "");
746 : 4419 : }
747 : :
748 : : /* Dump the tree of lexical scopes starting at SCOPE to stderr. FLAGS
749 : : is as in print_generic_expr. */
750 : :
751 : : DEBUG_FUNCTION void
752 : 0 : debug_scope_block (tree scope, dump_flags_t flags)
753 : : {
754 : 0 : dump_scope_block (stderr, 0, scope, flags);
755 : 0 : }
756 : :
757 : :
758 : : /* Dump the tree of lexical scopes of current_function_decl to FILE.
759 : : FLAGS is as in print_generic_expr. */
760 : :
761 : : void
762 : 1986 : dump_scope_blocks (FILE *file, dump_flags_t flags)
763 : : {
764 : 1986 : dump_scope_block (file, 0, DECL_INITIAL (current_function_decl), flags);
765 : 1986 : }
766 : :
767 : :
768 : : /* Dump the tree of lexical scopes of current_function_decl to stderr.
769 : : FLAGS is as in print_generic_expr. */
770 : :
771 : : DEBUG_FUNCTION void
772 : 0 : debug_scope_blocks (dump_flags_t flags)
773 : : {
774 : 0 : dump_scope_blocks (stderr, flags);
775 : 0 : }
776 : :
777 : : /* Remove local variables that are not referenced in the IL. */
778 : :
779 : : void
780 : 12099209 : remove_unused_locals (void)
781 : : {
782 : 12099209 : basic_block bb;
783 : 12099209 : tree var;
784 : 12099209 : unsigned srcidx, dstidx, num;
785 : 12099209 : bool have_local_clobbers = false;
786 : :
787 : : /* Removing declarations from lexical blocks when not optimizing is
788 : : not only a waste of time, it actually causes differences in stack
789 : : layout. */
790 : 12099209 : if (!optimize)
791 : 1315677 : return;
792 : :
793 : 10783532 : timevar_push (TV_REMOVE_UNUSED);
794 : :
795 : 10783532 : mark_scope_block_unused (DECL_INITIAL (current_function_decl));
796 : :
797 : 10783532 : usedvars = BITMAP_ALLOC (NULL);
798 : 10783532 : auto_bitmap useddebug;
799 : :
800 : : /* Walk the CFG marking all referenced symbols. */
801 : 85144741 : FOR_EACH_BB_FN (bb, cfun)
802 : : {
803 : 74361209 : gimple_stmt_iterator gsi;
804 : 74361209 : size_t i;
805 : 74361209 : edge_iterator ei;
806 : 74361209 : edge e;
807 : :
808 : : /* Walk the statements. */
809 : 647505472 : for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
810 : : {
811 : 498783054 : gimple *stmt = gsi_stmt (gsi);
812 : 498783054 : tree b = gimple_block (stmt);
813 : :
814 : : /* If we wanted to mark the block referenced by the inline
815 : : entry point marker as used, this would be a good spot to
816 : : do it. If the block is not otherwise used, the stmt will
817 : : be cleaned up in clean_unused_block_pointer. */
818 : 498783054 : if (is_gimple_debug (stmt))
819 : : {
820 : 240399260 : if (gimple_debug_bind_p (stmt))
821 : : {
822 : 177320810 : tree var = gimple_debug_bind_get_var (stmt);
823 : 177320810 : if (VAR_P (var))
824 : : {
825 : 166896082 : if (!gimple_debug_bind_get_value (stmt))
826 : : /* Run the 2nd phase. */
827 : : have_local_clobbers = true;
828 : : else
829 : 89609963 : bitmap_set_bit (useddebug, DECL_UID (var));
830 : : }
831 : : }
832 : 240399260 : continue;
833 : 240399260 : }
834 : :
835 : 258383794 : if (gimple_clobber_p (stmt))
836 : : {
837 : 13329071 : have_local_clobbers = true;
838 : 13329071 : continue;
839 : : }
840 : :
841 : 245054723 : if (gimple_call_internal_p (stmt, IFN_DEFERRED_INIT))
842 : : {
843 : 1160 : have_local_clobbers = true;
844 : 1160 : continue;
845 : : }
846 : :
847 : 245053563 : if (b)
848 : 223342594 : TREE_USED (b) = true;
849 : :
850 : 933355787 : for (i = 0; i < gimple_num_ops (stmt); i++)
851 : 688302224 : mark_all_vars_used (gimple_op_ptr (gsi_stmt (gsi), i));
852 : : }
853 : :
854 : 74361209 : for (gphi_iterator gpi = gsi_start_phis (bb);
855 : 100001440 : !gsi_end_p (gpi);
856 : 25640231 : gsi_next (&gpi))
857 : : {
858 : 25640231 : use_operand_p arg_p;
859 : 25640231 : ssa_op_iter i;
860 : 25640231 : tree def;
861 : 25640231 : gphi *phi = gpi.phi ();
862 : :
863 : 51280462 : if (virtual_operand_p (gimple_phi_result (phi)))
864 : 11867784 : continue;
865 : :
866 : 13772447 : def = gimple_phi_result (phi);
867 : 13772447 : mark_all_vars_used (&def);
868 : :
869 : 45840334 : FOR_EACH_PHI_ARG (arg_p, phi, i, SSA_OP_ALL_USES)
870 : : {
871 : 32067887 : tree arg = USE_FROM_PTR (arg_p);
872 : 32067887 : int index = PHI_ARG_INDEX_FROM_USE (arg_p);
873 : 32067887 : tree block =
874 : 32067887 : LOCATION_BLOCK (gimple_phi_arg_location (phi, index));
875 : 18565885 : if (block != NULL)
876 : 18562415 : TREE_USED (block) = true;
877 : 32067887 : mark_all_vars_used (&arg);
878 : : }
879 : : }
880 : :
881 : 178261563 : FOR_EACH_EDGE (e, ei, bb->succs)
882 : 103900354 : if (LOCATION_BLOCK (e->goto_locus) != NULL)
883 : 69922472 : TREE_USED (LOCATION_BLOCK (e->goto_locus)) = true;
884 : : }
885 : :
886 : : /* We do a two-pass approach about the out-of-scope clobbers. We want
887 : : to remove them if they are the only references to a local variable,
888 : : but we want to retain them when there's any other. So the first pass
889 : : ignores them, and the second pass (if there were any) tries to remove
890 : : them. We do the same for .DEFERRED_INIT. */
891 : 10783532 : if (have_local_clobbers)
892 : 57158315 : FOR_EACH_BB_FN (bb, cfun)
893 : : {
894 : 52428035 : gimple_stmt_iterator gsi;
895 : :
896 : 524484685 : for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi);)
897 : : {
898 : 419628615 : gimple *stmt = gsi_stmt (gsi);
899 : 419628615 : tree b = gimple_block (stmt);
900 : :
901 : 419628615 : if (gimple_clobber_p (stmt))
902 : : {
903 : 13329071 : tree lhs = gimple_assign_lhs (stmt);
904 : 13329071 : tree base = get_base_address (lhs);
905 : : /* Remove clobbers referencing unused vars, or clobbers
906 : : with MEM_REF lhs referencing uninitialized pointers. */
907 : 11282421 : if ((VAR_P (base) && !is_used_p (base))
908 : 23948075 : || (TREE_CODE (lhs) == MEM_REF
909 : 3442003 : && TREE_CODE (TREE_OPERAND (lhs, 0)) == SSA_NAME
910 : 2024447 : && SSA_NAME_IS_DEFAULT_DEF (TREE_OPERAND (lhs, 0))
911 : 1333633 : && (TREE_CODE (SSA_NAME_VAR (TREE_OPERAND (lhs, 0)))
912 : : != PARM_DECL)))
913 : : {
914 : 690529 : unlink_stmt_vdef (stmt);
915 : 690529 : gsi_remove (&gsi, true);
916 : 690529 : release_defs (stmt);
917 : 690529 : continue;
918 : : }
919 : 12638542 : if (b)
920 : 12064559 : TREE_USED (b) = true;
921 : : }
922 : 406299544 : else if (gimple_call_internal_p (stmt, IFN_DEFERRED_INIT))
923 : : {
924 : 1160 : tree lhs = gimple_call_lhs (stmt);
925 : 1160 : tree base = get_base_address (lhs);
926 : 1160 : if (DECL_P (base) && !is_used_p (base))
927 : : {
928 : 11 : unlink_stmt_vdef (stmt);
929 : 11 : gsi_remove (&gsi, true);
930 : 11 : release_defs (stmt);
931 : 11 : continue;
932 : : }
933 : 1149 : if (b)
934 : 1149 : TREE_USED (b) = true;
935 : : }
936 : 406298384 : else if (gimple_debug_bind_p (stmt))
937 : : {
938 : 174448342 : tree var = gimple_debug_bind_get_var (stmt);
939 : 178222174 : if (VAR_P (var)
940 : 164258584 : && !bitmap_bit_p (useddebug, DECL_UID (var))
941 : 178647033 : && !is_used_p (var))
942 : : {
943 : 3773832 : if (dump_file && (dump_flags & TDF_DETAILS))
944 : 0 : fprintf (dump_file, "Dead debug bind reset to %u\n",
945 : 0 : DECL_UID (var));
946 : 3773832 : gsi_remove (&gsi, true);
947 : 3773832 : continue;
948 : : }
949 : : }
950 : 415164243 : gsi_next (&gsi);
951 : : }
952 : : }
953 : :
954 : 10783532 : if (cfun->has_simduid_loops)
955 : : {
956 : 124884 : for (auto loop : loops_list (cfun, 0))
957 : 46617 : if (loop->simduid && !is_used_p (loop->simduid))
958 : 26368 : loop->simduid = NULL_TREE;
959 : : }
960 : :
961 : 10783532 : cfun->has_local_explicit_reg_vars = false;
962 : :
963 : : /* Remove unmarked local and global vars from local_decls. */
964 : 10783532 : num = vec_safe_length (cfun->local_decls);
965 : 69419823 : for (srcidx = 0, dstidx = 0; srcidx < num; srcidx++)
966 : : {
967 : 58636291 : var = (*cfun->local_decls)[srcidx];
968 : 58636291 : if (VAR_P (var))
969 : : {
970 : 58636291 : if (!is_used_p (var))
971 : : {
972 : 25189710 : tree def;
973 : 25189710 : if (cfun->nonlocal_goto_save_area
974 : 25189710 : && TREE_OPERAND (cfun->nonlocal_goto_save_area, 0) == var)
975 : 10 : cfun->nonlocal_goto_save_area = NULL;
976 : : /* Release any default def associated with var. */
977 : 25189710 : if ((def = ssa_default_def (cfun, var)) != NULL_TREE)
978 : : {
979 : 1118450 : set_ssa_default_def (cfun, var, NULL_TREE);
980 : 1118450 : release_ssa_name (def);
981 : : }
982 : 25189710 : continue;
983 : 25189710 : }
984 : : }
985 : 33446581 : if (VAR_P (var) && DECL_HARD_REGISTER (var) && !is_global_var (var))
986 : 6572 : cfun->has_local_explicit_reg_vars = true;
987 : :
988 : 33446581 : if (srcidx != dstidx)
989 : 13868292 : (*cfun->local_decls)[dstidx] = var;
990 : 33446581 : dstidx++;
991 : : }
992 : 10783532 : if (dstidx != num)
993 : : {
994 : 3804602 : statistics_counter_event (cfun, "unused VAR_DECLs removed", num - dstidx);
995 : 3804602 : cfun->local_decls->truncate (dstidx);
996 : : }
997 : :
998 : 10783532 : remove_unused_scope_block_p (DECL_INITIAL (current_function_decl),
999 : 10783532 : polymorphic_ctor_dtor_p (current_function_decl,
1000 : : true) != NULL_TREE);
1001 : 10783532 : clear_unused_block_pointer ();
1002 : :
1003 : 10783532 : BITMAP_FREE (usedvars);
1004 : :
1005 : 10783532 : if (dump_file && (dump_flags & TDF_DETAILS))
1006 : : {
1007 : 1984 : fprintf (dump_file, "Scope blocks after cleanups:\n");
1008 : 1984 : dump_scope_blocks (dump_file, dump_flags);
1009 : : }
1010 : :
1011 : 10783532 : timevar_pop (TV_REMOVE_UNUSED);
1012 : 10783532 : }
1013 : :
1014 : : /* Allocate and return a new live range information object base on MAP. */
1015 : :
1016 : : static tree_live_info_p
1017 : 1253820 : new_tree_live_info (var_map map)
1018 : : {
1019 : 1253820 : tree_live_info_p live;
1020 : 1253820 : basic_block bb;
1021 : :
1022 : 1253820 : live = XNEW (struct tree_live_info_d);
1023 : 1253820 : live->map = map;
1024 : 1253820 : live->num_blocks = last_basic_block_for_fn (cfun);
1025 : :
1026 : 1253820 : bitmap_obstack_initialize (&live->livein_obstack);
1027 : 1253820 : bitmap_obstack_initialize (&live->liveout_obstack);
1028 : :
1029 : 1253820 : live->livein = XCNEWVEC (bitmap_head, last_basic_block_for_fn (cfun));
1030 : 1253820 : live->liveout = XCNEWVEC (bitmap_head, last_basic_block_for_fn (cfun));
1031 : 12384566 : for (unsigned i = 0; map->vec_bbs.iterate (i, &bb); ++i)
1032 : : {
1033 : 11130746 : bitmap_initialize (&live->livein[bb->index], &live->livein_obstack);
1034 : 11130746 : bitmap_initialize (&live->liveout[bb->index], &live->liveout_obstack);
1035 : : }
1036 : :
1037 : 1253820 : live->work_stack = XNEWVEC (int, last_basic_block_for_fn (cfun));
1038 : 1253820 : live->stack_top = live->work_stack;
1039 : :
1040 : 1253820 : return live;
1041 : : }
1042 : :
1043 : :
1044 : : /* Free storage for live range info object LIVE. */
1045 : :
1046 : : void
1047 : 1253820 : delete_tree_live_info (tree_live_info_p live)
1048 : : {
1049 : 1253820 : if (live->livein)
1050 : : {
1051 : 0 : bitmap_obstack_release (&live->livein_obstack);
1052 : 0 : free (live->livein);
1053 : : }
1054 : 1253820 : if (live->liveout)
1055 : : {
1056 : 1253820 : bitmap_obstack_release (&live->liveout_obstack);
1057 : 1253820 : free (live->liveout);
1058 : : }
1059 : 1253820 : free (live->work_stack);
1060 : 1253820 : free (live);
1061 : 1253820 : }
1062 : :
1063 : :
1064 : : /* Visit basic block BB and propagate any required live on entry bits from
1065 : : LIVE into the predecessors. VISITED is the bitmap of visited blocks.
1066 : : TMP is a temporary work bitmap which is passed in to avoid reallocating
1067 : : it each time. */
1068 : :
1069 : : static void
1070 : 12868876 : loe_visit_block (tree_live_info_p live, basic_block bb, sbitmap visited)
1071 : : {
1072 : 12868876 : edge e;
1073 : 12868876 : bool change;
1074 : 12868876 : edge_iterator ei;
1075 : 12868876 : basic_block pred_bb;
1076 : 12868876 : bitmap loe;
1077 : :
1078 : 12868876 : gcc_checking_assert (!bitmap_bit_p (visited, bb->index));
1079 : 12868876 : bitmap_set_bit (visited, bb->index);
1080 : :
1081 : 12868876 : loe = live_on_entry (live, bb);
1082 : :
1083 : 31591045 : FOR_EACH_EDGE (e, ei, bb->preds)
1084 : : {
1085 : 18722169 : pred_bb = e->src;
1086 : 18722169 : if (!region_contains_p (live->map, pred_bb))
1087 : 1270371 : continue;
1088 : : /* Variables live-on-entry from BB that aren't defined in the
1089 : : predecessor block. This should be the live on entry vars to pred.
1090 : : Note that liveout is the DEFs in a block while live on entry is
1091 : : being calculated.
1092 : : Add these bits to live-on-entry for the pred. if there are any
1093 : : changes, and pred_bb has been visited already, add it to the
1094 : : revisit stack. */
1095 : 17451798 : change = bitmap_ior_and_compl_into (live_on_entry (live, pred_bb),
1096 : 17451798 : loe, &live->liveout[pred_bb->index]);
1097 : 17451798 : if (change
1098 : 17451798 : && bitmap_bit_p (visited, pred_bb->index))
1099 : : {
1100 : 1738130 : bitmap_clear_bit (visited, pred_bb->index);
1101 : 1738130 : *(live->stack_top)++ = pred_bb->index;
1102 : : }
1103 : : }
1104 : 12868876 : }
1105 : :
1106 : :
1107 : : /* Using LIVE, fill in all the live-on-entry blocks between the defs and uses
1108 : : of all the variables. */
1109 : :
1110 : : static void
1111 : 1253820 : live_worklist (tree_live_info_p live)
1112 : : {
1113 : 1253820 : unsigned b;
1114 : 1253820 : basic_block bb;
1115 : 1253820 : auto_sbitmap visited (last_basic_block_for_fn (cfun) + 1);
1116 : :
1117 : 1253820 : bitmap_clear (visited);
1118 : :
1119 : : /* Visit region's blocks in reverse order and propagate live on entry values
1120 : : into the predecessors blocks. */
1121 : 13638386 : for (unsigned i = live->map->vec_bbs.length () - 1;
1122 : 12384566 : live->map->vec_bbs.iterate (i, &bb); --i)
1123 : 11130746 : loe_visit_block (live, bb, visited);
1124 : :
1125 : : /* Process any blocks which require further iteration. */
1126 : 2991950 : while (live->stack_top != live->work_stack)
1127 : : {
1128 : 1738130 : b = *--(live->stack_top);
1129 : 1738130 : loe_visit_block (live, BASIC_BLOCK_FOR_FN (cfun, b), visited);
1130 : : }
1131 : 1253820 : }
1132 : :
1133 : :
1134 : : /* Calculate the initial live on entry vector for SSA_NAME using immediate_use
1135 : : links. Set the live on entry fields in LIVE. Def's are marked temporarily
1136 : : in the liveout vector. */
1137 : :
1138 : : static void
1139 : 10694680 : set_var_live_on_entry (tree ssa_name, tree_live_info_p live)
1140 : : {
1141 : 10694680 : int p;
1142 : 10694680 : gimple *stmt;
1143 : 10694680 : use_operand_p use;
1144 : 10694680 : basic_block def_bb = NULL;
1145 : 10694680 : imm_use_iterator imm_iter;
1146 : :
1147 : 10694680 : p = var_to_partition (live->map, ssa_name);
1148 : 10694680 : if (p == NO_PARTITION)
1149 : 700786 : return;
1150 : :
1151 : 10694680 : stmt = SSA_NAME_DEF_STMT (ssa_name);
1152 : 10694680 : if (stmt)
1153 : : {
1154 : 10694680 : def_bb = gimple_bb (stmt);
1155 : : /* Mark defs in liveout bitmap temporarily. */
1156 : 10694680 : if (def_bb && region_contains_p (live->map, def_bb))
1157 : 7095239 : bitmap_set_bit (&live->liveout[def_bb->index], p);
1158 : : }
1159 : : else
1160 : 0 : def_bb = ENTRY_BLOCK_PTR_FOR_FN (cfun);
1161 : :
1162 : : /* An undefined local variable does not need to be very alive. */
1163 : 10694680 : if (ssa_undefined_value_p (ssa_name, false))
1164 : : return;
1165 : :
1166 : : /* Visit each use of SSA_NAME and if it isn't in the same block as the def,
1167 : : add it to the list of live on entry blocks. */
1168 : 32274259 : FOR_EACH_IMM_USE_FAST (use, imm_iter, ssa_name)
1169 : : {
1170 : 22280365 : gimple *use_stmt = USE_STMT (use);
1171 : 22280365 : basic_block add_block = NULL;
1172 : :
1173 : 22280365 : if (gimple_code (use_stmt) == GIMPLE_PHI)
1174 : : {
1175 : : /* Uses in PHI's are considered to be live at exit of the SRC block
1176 : : as this is where a copy would be inserted. Check to see if it is
1177 : : defined in that block, or whether its live on entry. */
1178 : 5542429 : int index = PHI_ARG_INDEX_FROM_USE (use);
1179 : 5542429 : edge e = gimple_phi_arg_edge (as_a <gphi *> (use_stmt), index);
1180 : 5542429 : if (e->src != def_bb && region_contains_p (live->map, e->src))
1181 : 1803728 : add_block = e->src;
1182 : : }
1183 : 16737936 : else if (is_gimple_debug (use_stmt))
1184 : 4050259 : continue;
1185 : : else
1186 : : {
1187 : : /* If its not defined in this block, its live on entry. */
1188 : 12687677 : basic_block use_bb = gimple_bb (use_stmt);
1189 : 12687677 : if (use_bb != def_bb && region_contains_p (live->map, use_bb))
1190 : : add_block = use_bb;
1191 : : }
1192 : :
1193 : : /* If there was a live on entry use, set the bit. */
1194 : 10073996 : if (add_block)
1195 : 10073996 : bitmap_set_bit (&live->livein[add_block->index], p);
1196 : : }
1197 : : }
1198 : :
1199 : :
1200 : : /* Calculate the live on exit vectors based on the entry info in LIVEINFO. */
1201 : :
1202 : : static void
1203 : 1253820 : calculate_live_on_exit (tree_live_info_p liveinfo)
1204 : : {
1205 : 1253820 : basic_block bb;
1206 : 1253820 : edge e;
1207 : 1253820 : edge_iterator ei;
1208 : :
1209 : : /* live on entry calculations used liveout vectors for defs, clear them. */
1210 : 12384566 : for (unsigned i = 0; liveinfo->map->vec_bbs.iterate (i, &bb); ++i)
1211 : 11130746 : bitmap_clear (&liveinfo->liveout[bb->index]);
1212 : :
1213 : : /* Set all the live-on-exit bits for uses in PHIs. */
1214 : 12384566 : FOR_EACH_BB_FN (bb, cfun)
1215 : : {
1216 : 11130746 : gphi_iterator gsi;
1217 : 11130746 : size_t i;
1218 : :
1219 : : /* Mark the PHI arguments which are live on exit to the pred block. */
1220 : 13881587 : for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
1221 : : {
1222 : 2750841 : gphi *phi = gsi.phi ();
1223 : 5501682 : if (virtual_operand_p (gimple_phi_result (phi)))
1224 : 5654 : continue;
1225 : 9611184 : for (i = 0; i < gimple_phi_num_args (phi); i++)
1226 : : {
1227 : 6865997 : tree t = PHI_ARG_DEF (phi, i);
1228 : 6865997 : int p;
1229 : :
1230 : 6865997 : if (TREE_CODE (t) != SSA_NAME)
1231 : 1295059 : continue;
1232 : :
1233 : 5570938 : p = var_to_partition (liveinfo->map, t);
1234 : 5570938 : if (p == NO_PARTITION)
1235 : 1405 : continue;
1236 : 5569533 : e = gimple_phi_arg_edge (phi, i);
1237 : 5569533 : if (region_contains_p (liveinfo->map, e->src))
1238 : 5569316 : bitmap_set_bit (&liveinfo->liveout[e->src->index], p);
1239 : : }
1240 : : }
1241 : :
1242 : 11130746 : if (!region_contains_p (liveinfo->map, bb))
1243 : 0 : continue;
1244 : :
1245 : : /* Add each successors live on entry to this bock live on exit. */
1246 : 27266046 : FOR_EACH_EDGE (e, ei, bb->succs)
1247 : 16135300 : if (region_contains_p (liveinfo->map, e->dest))
1248 : 14903698 : bitmap_ior_into (&liveinfo->liveout[bb->index],
1249 : 14903698 : live_on_entry (liveinfo, e->dest));
1250 : : }
1251 : 1253820 : }
1252 : :
1253 : :
1254 : : /* Given partition map MAP, calculate all the live on entry bitmaps for
1255 : : each partition. Return a new live info object. */
1256 : :
1257 : : tree_live_info_p
1258 : 1253820 : calculate_live_ranges (var_map map, bool want_livein)
1259 : : {
1260 : 1253820 : tree var;
1261 : 1253820 : unsigned i;
1262 : 1253820 : tree_live_info_p live;
1263 : :
1264 : 1253820 : live = new_tree_live_info (map);
1265 : 13202320 : for (i = 0; i < num_var_partitions (map); i++)
1266 : : {
1267 : 10694680 : var = partition_to_var (map, i);
1268 : 10694680 : if (var != NULL_TREE)
1269 : 10694680 : set_var_live_on_entry (var, live);
1270 : : }
1271 : :
1272 : 1253820 : live_worklist (live);
1273 : :
1274 : 1253820 : if (flag_checking)
1275 : 1253803 : verify_live_on_entry (live);
1276 : :
1277 : 1253820 : calculate_live_on_exit (live);
1278 : :
1279 : 1253820 : if (!want_livein)
1280 : : {
1281 : 1253820 : bitmap_obstack_release (&live->livein_obstack);
1282 : 1253820 : free (live->livein);
1283 : 1253820 : live->livein = NULL;
1284 : : }
1285 : :
1286 : 1253820 : return live;
1287 : : }
1288 : :
1289 : : /* Data structure for compute_live_vars* functions. */
1290 : :
1291 : : struct compute_live_vars_data {
1292 : : /* Vector of bitmaps for live vars indices at the end of basic blocks,
1293 : : indexed by bb->index. ACTIVE[ENTRY_BLOCK] must be empty bitmap,
1294 : : ACTIVE[EXIT_BLOCK] is used for STOP_AFTER. */
1295 : : vec<bitmap_head> active;
1296 : : /* Work bitmap of currently live variables. */
1297 : : bitmap work;
1298 : : /* Set of interesting variables. Variables with uids not in this
1299 : : hash_map are not tracked. */
1300 : : live_vars_map *vars;
1301 : : };
1302 : :
1303 : : /* Callback for walk_stmt_load_store_addr_ops. If OP is a VAR_DECL with
1304 : : uid set in DATA->vars, enter its corresponding index into bitmap
1305 : : DATA->work. */
1306 : :
1307 : : static bool
1308 : 24643549 : compute_live_vars_visit (gimple *, tree op, tree, void *pdata)
1309 : : {
1310 : 24643549 : compute_live_vars_data *data = (compute_live_vars_data *) pdata;
1311 : 24643549 : op = get_base_address (op);
1312 : 24643549 : if (op && VAR_P (op))
1313 : 16465218 : if (unsigned int *v = data->vars->get (DECL_UID (op)))
1314 : 12949393 : bitmap_set_bit (data->work, *v);
1315 : 24643549 : return false;
1316 : : }
1317 : :
1318 : : /* Helper routine for compute_live_vars, calculating the sets of live
1319 : : variables at the end of BB, leaving the result in DATA->work.
1320 : : If STOP_AFTER is non-NULL, stop processing after that stmt. */
1321 : :
1322 : : static void
1323 : 12153668 : compute_live_vars_1 (basic_block bb, compute_live_vars_data *data,
1324 : : gimple *stop_after)
1325 : : {
1326 : 12153668 : edge e;
1327 : 12153668 : edge_iterator ei;
1328 : 12153668 : gimple_stmt_iterator gsi;
1329 : 12153668 : walk_stmt_load_store_addr_fn visit = compute_live_vars_visit;
1330 : :
1331 : 12153668 : bitmap_clear (data->work);
1332 : 29384515 : FOR_EACH_EDGE (e, ei, bb->preds)
1333 : 17230847 : bitmap_ior_into (data->work, &data->active[e->src->index]);
1334 : :
1335 : 17472651 : for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
1336 : 5318983 : walk_stmt_load_store_addr_ops (gsi_stmt (gsi), data, NULL, NULL, visit);
1337 : 149128418 : for (gsi = gsi_after_labels (bb); !gsi_end_p (gsi); gsi_next (&gsi))
1338 : : {
1339 : 137207516 : gimple *stmt = gsi_stmt (gsi);
1340 : :
1341 : 137207516 : if (gimple_clobber_p (stmt))
1342 : : {
1343 : 4303507 : tree lhs = gimple_assign_lhs (stmt);
1344 : 4303507 : if (VAR_P (lhs))
1345 : 3166387 : if (unsigned int *v = data->vars->get (DECL_UID (lhs)))
1346 : 2683487 : bitmap_clear_bit (data->work, *v);
1347 : : }
1348 : 132904009 : else if (!is_gimple_debug (stmt))
1349 : 38388995 : walk_stmt_load_store_addr_ops (stmt, data, visit, visit, visit);
1350 : 137207516 : if (stmt == stop_after)
1351 : : break;
1352 : : }
1353 : 12153668 : }
1354 : :
1355 : : /* For function FN and live_vars_map (hash map from DECL_UIDs to a dense set of
1356 : : indexes of automatic variables VARS, compute which of those variables are
1357 : : (might be) live at the end of each basic block. */
1358 : :
1359 : : vec<bitmap_head>
1360 : 306571 : compute_live_vars (struct function *fn, live_vars_map *vars)
1361 : : {
1362 : 306571 : vec<bitmap_head> active;
1363 : :
1364 : : /* We approximate the live range of a stack variable by taking the first
1365 : : mention of its name as starting point(s), and by the end-of-scope
1366 : : death clobber added by gimplify as ending point(s) of the range.
1367 : : This overapproximates in the case we for instance moved an address-taken
1368 : : operation upward, without also moving a dereference to it upwards.
1369 : : But it's conservatively correct as a variable never can hold values
1370 : : before its name is mentioned at least once.
1371 : :
1372 : : We then do a mostly classical bitmap liveness algorithm. */
1373 : :
1374 : 306571 : active.create (last_basic_block_for_fn (fn));
1375 : 306571 : active.quick_grow_cleared (last_basic_block_for_fn (fn));
1376 : 6812051 : for (int i = 0; i < last_basic_block_for_fn (fn); i++)
1377 : 6505480 : bitmap_initialize (&active[i], &bitmap_default_obstack);
1378 : :
1379 : 306571 : bitmap work = BITMAP_ALLOC (NULL);
1380 : :
1381 : 306571 : int *rpo = XNEWVEC (int, last_basic_block_for_fn (fn));
1382 : 306571 : int n_bbs = pre_and_rev_post_order_compute_fn (fn, NULL, rpo, false);
1383 : :
1384 : 306571 : bool changed = true;
1385 : 306571 : compute_live_vars_data data = { active, work, vars };
1386 : 856432 : while (changed)
1387 : : {
1388 : : int i;
1389 : : changed = false;
1390 : 12470763 : for (i = 0; i < n_bbs; i++)
1391 : : {
1392 : 11920902 : basic_block bb = BASIC_BLOCK_FOR_FN (fn, rpo[i]);
1393 : 11920902 : compute_live_vars_1 (bb, &data, NULL);
1394 : 11920902 : if (bitmap_ior_into (&active[bb->index], work))
1395 : 4464611 : changed = true;
1396 : : }
1397 : : }
1398 : :
1399 : 306571 : free (rpo);
1400 : 306571 : BITMAP_FREE (work);
1401 : :
1402 : 306571 : return active;
1403 : : }
1404 : :
1405 : : /* For ACTIVE computed by compute_live_vars, compute a bitmap of variables
1406 : : live after the STOP_AFTER statement and return that bitmap. */
1407 : :
1408 : : bitmap
1409 : 232766 : live_vars_at_stmt (vec<bitmap_head> &active, live_vars_map *vars,
1410 : : gimple *stop_after)
1411 : : {
1412 : 232766 : bitmap work = BITMAP_ALLOC (NULL);
1413 : 232766 : compute_live_vars_data data = { active, work, vars };
1414 : 232766 : basic_block bb = gimple_bb (stop_after);
1415 : 232766 : compute_live_vars_1 (bb, &data, stop_after);
1416 : 232766 : return work;
1417 : : }
1418 : :
1419 : : /* Destroy what compute_live_vars has returned when it is no longer needed. */
1420 : :
1421 : : void
1422 : 306571 : destroy_live_vars (vec<bitmap_head> &active)
1423 : : {
1424 : 306571 : unsigned len = active.length ();
1425 : 6812051 : for (unsigned i = 0; i < len; i++)
1426 : 6505480 : bitmap_clear (&active[i]);
1427 : :
1428 : 306571 : active.release ();
1429 : 306571 : }
1430 : :
1431 : : /* Output partition map MAP to file F. */
1432 : :
1433 : : void
1434 : 166 : dump_var_map (FILE *f, var_map map)
1435 : : {
1436 : 166 : int t;
1437 : 166 : unsigned x, y;
1438 : 166 : int p;
1439 : :
1440 : 166 : fprintf (f, "\nPartition map \n\n");
1441 : :
1442 : 1013 : for (x = 0; x < map->num_partitions; x++)
1443 : : {
1444 : 681 : if (map->view_to_partition != NULL)
1445 : 305 : p = map->view_to_partition[x];
1446 : : else
1447 : 376 : p = x;
1448 : :
1449 : 681 : if (ssa_name (p) == NULL_TREE
1450 : 1260 : || virtual_operand_p (ssa_name (p)))
1451 : 215 : continue;
1452 : :
1453 : : t = 0;
1454 : 8474 : for (y = 1; y < num_ssa_names; y++)
1455 : : {
1456 : 8008 : p = partition_find (map->var_partition, y);
1457 : 8008 : if (map->partition_to_view)
1458 : 5071 : p = map->partition_to_view[p];
1459 : 8008 : if (p == (int)x)
1460 : : {
1461 : 498 : if (t++ == 0)
1462 : : {
1463 : 466 : fprintf (f, "Partition %d (", x);
1464 : 466 : print_generic_expr (f, partition_to_var (map, p), TDF_SLIM);
1465 : 466 : fprintf (f, " - ");
1466 : : }
1467 : 498 : fprintf (f, "%d ", y);
1468 : : }
1469 : : }
1470 : 466 : if (t != 0)
1471 : 466 : fprintf (f, ")\n");
1472 : : }
1473 : 166 : fprintf (f, "\n");
1474 : 166 : }
1475 : :
1476 : :
1477 : : /* Generic dump for the above. */
1478 : :
1479 : : DEBUG_FUNCTION void
1480 : 0 : debug (_var_map &ref)
1481 : : {
1482 : 0 : dump_var_map (stderr, &ref);
1483 : 0 : }
1484 : :
1485 : : DEBUG_FUNCTION void
1486 : 0 : debug (_var_map *ptr)
1487 : : {
1488 : 0 : if (ptr)
1489 : 0 : debug (*ptr);
1490 : : else
1491 : 0 : fprintf (stderr, "<nil>\n");
1492 : 0 : }
1493 : :
1494 : :
1495 : : /* Output live range info LIVE to file F, controlled by FLAG. */
1496 : :
1497 : : void
1498 : 32 : dump_live_info (FILE *f, tree_live_info_p live, int flag)
1499 : : {
1500 : 32 : basic_block bb;
1501 : 32 : unsigned i;
1502 : 32 : var_map map = live->map;
1503 : 32 : bitmap_iterator bi;
1504 : :
1505 : 32 : if ((flag & LIVEDUMP_ENTRY) && live->livein)
1506 : : {
1507 : 0 : FOR_EACH_BB_FN (bb, cfun)
1508 : : {
1509 : 0 : fprintf (f, "\nLive on entry to BB%d : ", bb->index);
1510 : 0 : EXECUTE_IF_SET_IN_BITMAP (&live->livein[bb->index], 0, i, bi)
1511 : : {
1512 : 0 : print_generic_expr (f, partition_to_var (map, i), TDF_SLIM);
1513 : 0 : fprintf (f, " ");
1514 : : }
1515 : 0 : fprintf (f, "\n");
1516 : : }
1517 : : }
1518 : :
1519 : 32 : if ((flag & LIVEDUMP_EXIT) && live->liveout)
1520 : : {
1521 : 0 : FOR_EACH_BB_FN (bb, cfun)
1522 : : {
1523 : 0 : fprintf (f, "\nLive on exit from BB%d : ", bb->index);
1524 : 0 : EXECUTE_IF_SET_IN_BITMAP (&live->liveout[bb->index], 0, i, bi)
1525 : : {
1526 : 0 : print_generic_expr (f, partition_to_var (map, i), TDF_SLIM);
1527 : 0 : fprintf (f, " ");
1528 : : }
1529 : 0 : fprintf (f, "\n");
1530 : : }
1531 : : }
1532 : 32 : }
1533 : :
1534 : :
1535 : : /* Generic dump for the above. */
1536 : :
1537 : : DEBUG_FUNCTION void
1538 : 0 : debug (tree_live_info_d &ref)
1539 : : {
1540 : 0 : dump_live_info (stderr, &ref, 0);
1541 : 0 : }
1542 : :
1543 : : DEBUG_FUNCTION void
1544 : 0 : debug (tree_live_info_d *ptr)
1545 : : {
1546 : 0 : if (ptr)
1547 : 0 : debug (*ptr);
1548 : : else
1549 : 0 : fprintf (stderr, "<nil>\n");
1550 : 0 : }
1551 : :
1552 : :
1553 : : /* Verify that the info in LIVE matches the current cfg. */
1554 : :
1555 : : static void
1556 : 1253803 : verify_live_on_entry (tree_live_info_p live)
1557 : : {
1558 : 1253803 : unsigned i;
1559 : 1253803 : tree var;
1560 : 1253803 : gimple *stmt;
1561 : 1253803 : basic_block bb;
1562 : 1253803 : edge e;
1563 : 1253803 : int num;
1564 : 1253803 : edge_iterator ei;
1565 : 1253803 : var_map map = live->map;
1566 : :
1567 : : /* Check for live on entry partitions and report those with a DEF in
1568 : : the program. This will typically mean an optimization has done
1569 : : something wrong. */
1570 : 1253803 : bb = ENTRY_BLOCK_PTR_FOR_FN (cfun);
1571 : 1253803 : num = 0;
1572 : 2507606 : FOR_EACH_EDGE (e, ei, bb->succs)
1573 : : {
1574 : 1253803 : int entry_block = e->dest->index;
1575 : 1253803 : if (!region_contains_p (live->map, e->dest))
1576 : 0 : continue;
1577 : 11948427 : for (i = 0; i < (unsigned)num_var_partitions (map); i++)
1578 : : {
1579 : 10694624 : basic_block tmp;
1580 : 10694624 : tree d = NULL_TREE;
1581 : 10694624 : bitmap loe;
1582 : 10694624 : var = partition_to_var (map, i);
1583 : 10694624 : stmt = SSA_NAME_DEF_STMT (var);
1584 : 10694624 : tmp = gimple_bb (stmt);
1585 : 10694624 : if (SSA_NAME_VAR (var))
1586 : 7616069 : d = ssa_default_def (cfun, SSA_NAME_VAR (var));
1587 : :
1588 : 10694624 : loe = live_on_entry (live, e->dest);
1589 : 10694624 : if (loe && bitmap_bit_p (loe, i))
1590 : : {
1591 : 1928736 : if (!gimple_nop_p (stmt))
1592 : : {
1593 : 0 : num++;
1594 : 0 : print_generic_expr (stderr, var, TDF_SLIM);
1595 : 0 : fprintf (stderr, " is defined ");
1596 : 0 : if (tmp)
1597 : 0 : fprintf (stderr, " in BB%d, ", tmp->index);
1598 : 0 : fprintf (stderr, "by:\n");
1599 : 0 : print_gimple_stmt (stderr, stmt, 0, TDF_SLIM);
1600 : 0 : fprintf (stderr, "\nIt is also live-on-entry to entry BB %d",
1601 : : entry_block);
1602 : 0 : fprintf (stderr, " So it appears to have multiple defs.\n");
1603 : : }
1604 : : else
1605 : : {
1606 : 1928736 : if (d != var)
1607 : : {
1608 : 0 : num++;
1609 : 0 : print_generic_expr (stderr, var, TDF_SLIM);
1610 : 0 : fprintf (stderr, " is live-on-entry to BB%d ",
1611 : : entry_block);
1612 : 0 : if (d)
1613 : : {
1614 : 0 : fprintf (stderr, " but is not the default def of ");
1615 : 0 : print_generic_expr (stderr, d, TDF_SLIM);
1616 : 0 : fprintf (stderr, "\n");
1617 : : }
1618 : : else
1619 : 0 : fprintf (stderr, " and there is no default def.\n");
1620 : : }
1621 : : }
1622 : : }
1623 : : else
1624 : 8765888 : if (d == var)
1625 : : {
1626 : : /* An undefined local variable does not need to be very
1627 : : alive. */
1628 : 1670678 : if (ssa_undefined_value_p (var, false))
1629 : 1670678 : continue;
1630 : :
1631 : : /* The only way this var shouldn't be marked live on entry is
1632 : : if it occurs in a PHI argument of the block. */
1633 : 969938 : size_t z;
1634 : 969938 : bool ok = false;
1635 : 969938 : gphi_iterator gsi;
1636 : 969938 : for (gsi = gsi_start_phis (e->dest);
1637 : 970140 : !gsi_end_p (gsi) && !ok;
1638 : 202 : gsi_next (&gsi))
1639 : : {
1640 : 202 : gphi *phi = gsi.phi ();
1641 : 404 : if (virtual_operand_p (gimple_phi_result (phi)))
1642 : 0 : continue;
1643 : 329 : for (z = 0; z < gimple_phi_num_args (phi); z++)
1644 : 267 : if (var == gimple_phi_arg_def (phi, z))
1645 : : {
1646 : : ok = true;
1647 : : break;
1648 : : }
1649 : : }
1650 : 969938 : if (ok)
1651 : 140 : continue;
1652 : : /* Expand adds unused default defs for PARM_DECLs and
1653 : : RESULT_DECLs. They're ok. */
1654 : 969798 : if (has_zero_uses (var)
1655 : 969798 : && SSA_NAME_VAR (var)
1656 : 1939596 : && !VAR_P (SSA_NAME_VAR (var)))
1657 : 969798 : continue;
1658 : 0 : num++;
1659 : 0 : print_generic_expr (stderr, var, TDF_SLIM);
1660 : 0 : fprintf (stderr, " is not marked live-on-entry to entry BB%d ",
1661 : : entry_block);
1662 : 0 : fprintf (stderr, "but it is a default def so it should be.\n");
1663 : : }
1664 : : }
1665 : : }
1666 : 1253803 : gcc_assert (num <= 0);
1667 : 1253803 : }
1668 : :
1669 : :
1670 : : /* Virtual operand liveness analysis data init. */
1671 : :
1672 : : void
1673 : 187040 : virtual_operand_live::init ()
1674 : : {
1675 : 187040 : liveout = XCNEWVEC (tree, last_basic_block_for_fn (cfun) + 1);
1676 : 187040 : liveout[ENTRY_BLOCK] = ssa_default_def (cfun, gimple_vop (cfun));
1677 : 187040 : }
1678 : :
1679 : : /* Compute live-in of BB from cached live-out. */
1680 : :
1681 : : tree
1682 : 1723829 : virtual_operand_live::get_live_in (basic_block bb)
1683 : : {
1684 : : /* A virtual PHI is a convenient cache for live-in. */
1685 : 1723829 : gphi *phi = get_virtual_phi (bb);
1686 : 1723829 : if (phi)
1687 : 529776 : return gimple_phi_result (phi);
1688 : :
1689 : 1194053 : if (!liveout)
1690 : 187040 : init ();
1691 : :
1692 : : /* Since we don't have a virtual PHI and we don't know whether there's
1693 : : a downstream virtual use (and thus PHIs are inserted where necessary)
1694 : : we now have to check each incoming edge live-out. */
1695 : 1194053 : edge_iterator ei;
1696 : 1194053 : edge e;
1697 : 1194053 : tree livein = NULL_TREE;
1698 : 1194053 : bool first = true;
1699 : 2583989 : FOR_EACH_EDGE (e, ei, bb->preds)
1700 : 1389948 : if (e->flags & EDGE_DFS_BACK)
1701 : : /* We can ignore backedges since if there's a def there it would
1702 : : have forced a PHI in the source because it also acts as use
1703 : : downstream. */
1704 : 61512 : continue;
1705 : 1328436 : else if (first)
1706 : : {
1707 : 1194053 : livein = get_live_out (e->src);
1708 : 1194053 : first = false;
1709 : : }
1710 : 134383 : else if (get_live_out (e->src) != livein)
1711 : : /* When there's no virtual use downstream this indicates a point
1712 : : where we'd insert a PHI merging the different live virtual
1713 : : operands. */
1714 : : return NULL_TREE;
1715 : :
1716 : : return livein;
1717 : : }
1718 : :
1719 : : /* Compute live-out of BB. */
1720 : :
1721 : : tree
1722 : 1328436 : virtual_operand_live::get_live_out (basic_block bb)
1723 : : {
1724 : 1328436 : if (!liveout)
1725 : 0 : init ();
1726 : :
1727 : 1328436 : if (liveout[bb->index])
1728 : : return liveout[bb->index];
1729 : :
1730 : 773158 : tree lo = NULL_TREE;
1731 : 3611048 : for (auto gsi = gsi_last_bb (bb); !gsi_end_p (gsi); gsi_prev (&gsi))
1732 : : {
1733 : 2603972 : gimple *stmt = gsi_stmt (gsi);
1734 : 3485909 : if (gimple_vdef (stmt))
1735 : : {
1736 : : lo = gimple_vdef (stmt);
1737 : : break;
1738 : : }
1739 : 3173755 : if (gimple_vuse (stmt))
1740 : : {
1741 : : lo = gimple_vuse (stmt);
1742 : : break;
1743 : : }
1744 : : }
1745 : 773158 : if (!lo)
1746 : 233918 : lo = get_live_in (bb);
1747 : 773158 : liveout[bb->index] = lo;
1748 : 773158 : return lo;
1749 : : }
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