* lcm.c (optimize_mode_switching): Revert previous change.
[official-gcc.git] / gcc / ggc-common.c
blob57c193d5036a7bd6aece6efaa34ec7f48a0181e3
1 /* Simple garbage collection for the GNU compiler.
2 Copyright (C) 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 2, or (at your option) any later
9 version.
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 for more details.
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING. If not, write to the Free
18 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
19 02111-1307, USA. */
21 /* Generic garbage collection (GC) functions and data, not specific to
22 any particular GC implementation. */
24 #include "config.h"
25 #include "system.h"
26 #include "rtl.h"
27 #include "tree.h"
28 #include "tm_p.h"
29 #include "hash.h"
30 #include "hashtab.h"
31 #include "varray.h"
32 #include "ggc.h"
33 #include "langhooks.h"
35 /* Statistics about the allocation. */
36 static ggc_statistics *ggc_stats;
38 /* Trees that have been marked, but whose children still need marking. */
39 varray_type ggc_pending_trees;
41 static void ggc_mark_rtx_children_1 PARAMS ((rtx));
42 static void ggc_mark_rtx_ptr PARAMS ((void *));
43 static void ggc_mark_tree_ptr PARAMS ((void *));
44 static void ggc_mark_rtx_varray_ptr PARAMS ((void *));
45 static void ggc_mark_tree_varray_ptr PARAMS ((void *));
46 static void ggc_mark_tree_hash_table_ptr PARAMS ((void *));
47 static int ggc_htab_delete PARAMS ((void **, void *));
48 static void ggc_mark_trees PARAMS ((void));
49 static bool ggc_mark_tree_hash_table_entry PARAMS ((struct hash_entry *,
50 hash_table_key));
52 /* Maintain global roots that are preserved during GC. */
54 /* Global roots that are preserved during calls to gc. */
56 struct ggc_root
58 struct ggc_root *next;
59 void *base;
60 int nelt;
61 int size;
62 void (*cb) PARAMS ((void *));
65 static struct ggc_root *roots;
67 /* Add BASE as a new garbage collection root. It is an array of
68 length NELT with each element SIZE bytes long. CB is a
69 function that will be called with a pointer to each element
70 of the array; it is the intention that CB call the appropriate
71 routine to mark gc-able memory for that element. */
73 void
74 ggc_add_root (base, nelt, size, cb)
75 void *base;
76 int nelt, size;
77 void (*cb) PARAMS ((void *));
79 struct ggc_root *x = (struct ggc_root *) xmalloc (sizeof (*x));
81 x->next = roots;
82 x->base = base;
83 x->nelt = nelt;
84 x->size = size;
85 x->cb = cb;
87 roots = x;
90 /* Register an array of rtx as a GC root. */
92 void
93 ggc_add_rtx_root (base, nelt)
94 rtx *base;
95 int nelt;
97 ggc_add_root (base, nelt, sizeof (rtx), ggc_mark_rtx_ptr);
100 /* Register an array of trees as a GC root. */
102 void
103 ggc_add_tree_root (base, nelt)
104 tree *base;
105 int nelt;
107 ggc_add_root (base, nelt, sizeof (tree), ggc_mark_tree_ptr);
110 /* Register a varray of rtxs as a GC root. */
112 void
113 ggc_add_rtx_varray_root (base, nelt)
114 varray_type *base;
115 int nelt;
117 ggc_add_root (base, nelt, sizeof (varray_type),
118 ggc_mark_rtx_varray_ptr);
121 /* Register a varray of trees as a GC root. */
123 void
124 ggc_add_tree_varray_root (base, nelt)
125 varray_type *base;
126 int nelt;
128 ggc_add_root (base, nelt, sizeof (varray_type),
129 ggc_mark_tree_varray_ptr);
132 /* Register a hash table of trees as a GC root. */
134 void
135 ggc_add_tree_hash_table_root (base, nelt)
136 struct hash_table **base;
137 int nelt;
139 ggc_add_root (base, nelt, sizeof (struct hash_table *),
140 ggc_mark_tree_hash_table_ptr);
143 /* Remove the previously registered GC root at BASE. */
145 void
146 ggc_del_root (base)
147 void *base;
149 struct ggc_root *x, **p;
151 p = &roots, x = roots;
152 while (x)
154 if (x->base == base)
156 *p = x->next;
157 free (x);
158 return;
160 p = &x->next;
161 x = x->next;
164 abort ();
167 /* Add a hash table to be scanned when all roots have been processed. We
168 delete any entry in the table that has not been marked. */
170 struct d_htab_root
172 struct d_htab_root *next;
173 htab_t htab;
174 ggc_htab_marked_p marked_p;
175 ggc_htab_mark mark;
178 static struct d_htab_root *d_htab_roots;
180 /* Add X, an htab, to a list of htabs that contain objects which are allocated
181 from GC memory. Once all other roots are marked, we check each object in
182 the htab to see if it has already been marked. If not, it is deleted.
184 MARKED_P, if specified, is a function that returns 1 if the entry is to
185 be considered as "marked". If not present, the data structure pointed to
186 by the htab slot is tested. This function should be supplied if some
187 other object (such as something pointed to by that object) should be tested
188 in which case the function tests whether that object (or objects) are
189 marked (using ggc_marked_p) and returns nonzero if it is.
191 MARK, if specified, is a function that is passed the contents of a slot
192 that has been determined to have been "marked" (via the above function)
193 and marks any other objects pointed to by that object. For example,
194 we might have a hash table of memory attribute blocks, which are pointed
195 to by a MEM RTL but have a pointer to a DECL. MARKED_P in that case will
196 not be specified because we want to know if the attribute block is pointed
197 to by the MEM, but MARK must be specified because if the block has been
198 marked, we need to mark the DECL. */
200 void
201 ggc_add_deletable_htab (x, marked_p, mark)
202 PTR x;
203 ggc_htab_marked_p marked_p;
204 ggc_htab_mark mark;
206 struct d_htab_root *r
207 = (struct d_htab_root *) xmalloc (sizeof (struct d_htab_root));
209 r->next = d_htab_roots;
210 r->htab = (htab_t) x;
211 r->marked_p = marked_p ? marked_p : ggc_marked_p;
212 r->mark = mark;
213 d_htab_roots = r;
216 /* Process a slot of an htab by deleting it if it has not been marked. */
218 static int
219 ggc_htab_delete (slot, info)
220 void **slot;
221 void *info;
223 struct d_htab_root *r = (struct d_htab_root *) info;
225 if (! (*r->marked_p) (*slot))
226 htab_clear_slot (r->htab, slot);
227 else if (r->mark)
228 (*r->mark) (*slot);
230 return 1;
233 /* Iterate through all registered roots and mark each element. */
235 void
236 ggc_mark_roots ()
238 struct ggc_root *x;
239 struct d_htab_root *y;
241 VARRAY_TREE_INIT (ggc_pending_trees, 4096, "ggc_pending_trees");
243 for (x = roots; x != NULL; x = x->next)
245 char *elt = x->base;
246 int s = x->size, n = x->nelt;
247 void (*cb) PARAMS ((void *)) = x->cb;
248 int i;
250 for (i = 0; i < n; ++i, elt += s)
251 (*cb)(elt);
254 /* Mark all the queued up trees, and their children. */
255 ggc_mark_trees ();
256 VARRAY_FREE (ggc_pending_trees);
258 /* Now scan all hash tables that have objects which are to be deleted if
259 they are not already marked. Since these may mark more trees, we need
260 to reinitialize that varray. */
261 VARRAY_TREE_INIT (ggc_pending_trees, 1024, "ggc_pending_trees");
263 for (y = d_htab_roots; y != NULL; y = y->next)
264 htab_traverse (y->htab, ggc_htab_delete, (PTR) y);
265 ggc_mark_trees ();
266 VARRAY_FREE (ggc_pending_trees);
269 /* R had not been previously marked, but has now been marked via
270 ggc_set_mark. Now recurse and process the children. */
272 void
273 ggc_mark_rtx_children (r)
274 rtx r;
276 rtx i, last;
278 /* Special case the instruction chain. This is a data structure whose
279 chain length is potentially unbounded, and which contain references
280 within the chain (e.g. label_ref and insn_list). If do nothing here,
281 we risk blowing the stack recursing through a long chain of insns.
283 Combat this by marking all of the instructions in the chain before
284 marking the contents of those instructions. */
286 switch (GET_CODE (r))
288 case INSN:
289 case JUMP_INSN:
290 case CALL_INSN:
291 case NOTE:
292 case CODE_LABEL:
293 case BARRIER:
294 for (i = NEXT_INSN (r); ; i = NEXT_INSN (i))
295 if (! ggc_test_and_set_mark (i))
296 break;
297 last = i;
299 for (i = NEXT_INSN (r); i != last; i = NEXT_INSN (i))
300 ggc_mark_rtx_children_1 (i);
302 default:
303 break;
306 ggc_mark_rtx_children_1 (r);
309 static void
310 ggc_mark_rtx_children_1 (r)
311 rtx r;
313 const char *fmt;
314 int i;
315 rtx next_rtx;
319 enum rtx_code code = GET_CODE (r);
320 /* This gets set to a child rtx to eliminate tail recursion. */
321 next_rtx = NULL;
323 /* Collect statistics, if appropriate. */
324 if (ggc_stats)
326 ++ggc_stats->num_rtxs[(int) code];
327 ggc_stats->size_rtxs[(int) code] += ggc_get_size (r);
330 /* ??? If (some of) these are really pass-dependent info, do we
331 have any right poking our noses in? */
332 switch (code)
334 case MEM:
335 ggc_mark (MEM_ATTRS (r));
336 break;
337 case JUMP_INSN:
338 ggc_mark_rtx (JUMP_LABEL (r));
339 break;
340 case CODE_LABEL:
341 ggc_mark_rtx (LABEL_REFS (r));
342 break;
343 case LABEL_REF:
344 ggc_mark_rtx (LABEL_NEXTREF (r));
345 ggc_mark_rtx (CONTAINING_INSN (r));
346 break;
347 case ADDRESSOF:
348 ggc_mark_tree (ADDRESSOF_DECL (r));
349 break;
350 case NOTE:
351 switch (NOTE_LINE_NUMBER (r))
353 case NOTE_INSN_RANGE_BEG:
354 case NOTE_INSN_RANGE_END:
355 case NOTE_INSN_LIVE:
356 case NOTE_INSN_EXPECTED_VALUE:
357 ggc_mark_rtx (NOTE_RANGE_INFO (r));
358 break;
360 case NOTE_INSN_BLOCK_BEG:
361 case NOTE_INSN_BLOCK_END:
362 ggc_mark_tree (NOTE_BLOCK (r));
363 break;
365 default:
366 break;
368 break;
370 default:
371 break;
374 for (fmt = GET_RTX_FORMAT (GET_CODE (r)), i = 0; *fmt ; ++fmt, ++i)
376 rtx exp;
377 switch (*fmt)
379 case 'e': case 'u':
380 exp = XEXP (r, i);
381 if (ggc_test_and_set_mark (exp))
383 if (next_rtx == NULL)
384 next_rtx = exp;
385 else
386 ggc_mark_rtx_children (exp);
388 break;
389 case 'V': case 'E':
390 ggc_mark_rtvec (XVEC (r, i));
391 break;
395 while ((r = next_rtx) != NULL);
398 /* V had not been previously marked, but has now been marked via
399 ggc_set_mark. Now recurse and process the children. */
401 void
402 ggc_mark_rtvec_children (v)
403 rtvec v;
405 int i;
407 i = GET_NUM_ELEM (v);
408 while (--i >= 0)
409 ggc_mark_rtx (RTVEC_ELT (v, i));
412 /* Recursively set marks on all of the children of the
413 GCC_PENDING_TREES. */
415 static void
416 ggc_mark_trees ()
418 while (ggc_pending_trees->elements_used)
420 tree t;
421 enum tree_code code;
423 t = VARRAY_TOP_TREE (ggc_pending_trees);
424 VARRAY_POP (ggc_pending_trees);
425 code = TREE_CODE (t);
427 /* Collect statistics, if appropriate. */
428 if (ggc_stats)
430 ++ggc_stats->num_trees[(int) code];
431 ggc_stats->size_trees[(int) code] += ggc_get_size (t);
434 /* Bits from common. */
435 ggc_mark_tree (TREE_TYPE (t));
436 ggc_mark_tree (TREE_CHAIN (t));
438 /* Some nodes require special handling. */
439 switch (code)
441 case TREE_LIST:
442 ggc_mark_tree (TREE_PURPOSE (t));
443 ggc_mark_tree (TREE_VALUE (t));
444 continue;
446 case TREE_VEC:
448 int i = TREE_VEC_LENGTH (t);
450 while (--i >= 0)
451 ggc_mark_tree (TREE_VEC_ELT (t, i));
452 continue;
455 case COMPLEX_CST:
456 ggc_mark_tree (TREE_REALPART (t));
457 ggc_mark_tree (TREE_IMAGPART (t));
458 break;
460 case PARM_DECL:
461 ggc_mark_rtx (DECL_INCOMING_RTL (t));
462 break;
464 case FIELD_DECL:
465 ggc_mark_tree (DECL_FIELD_BIT_OFFSET (t));
466 break;
468 case IDENTIFIER_NODE:
469 (*lang_hooks.mark_tree) (t);
470 continue;
472 default:
473 break;
476 /* But in general we can handle them by class. */
477 switch (TREE_CODE_CLASS (code))
479 case 'd': /* A decl node. */
480 ggc_mark_tree (DECL_SIZE (t));
481 ggc_mark_tree (DECL_SIZE_UNIT (t));
482 ggc_mark_tree (DECL_NAME (t));
483 ggc_mark_tree (DECL_CONTEXT (t));
484 ggc_mark_tree (DECL_ARGUMENTS (t));
485 ggc_mark_tree (DECL_RESULT_FLD (t));
486 ggc_mark_tree (DECL_INITIAL (t));
487 ggc_mark_tree (DECL_ABSTRACT_ORIGIN (t));
488 ggc_mark_tree (DECL_SECTION_NAME (t));
489 ggc_mark_tree (DECL_ATTRIBUTES (t));
490 if (DECL_RTL_SET_P (t))
491 ggc_mark_rtx (DECL_RTL (t));
492 ggc_mark_rtx (DECL_LIVE_RANGE_RTL (t));
493 ggc_mark_tree (DECL_VINDEX (t));
494 if (DECL_ASSEMBLER_NAME_SET_P (t))
495 ggc_mark_tree (DECL_ASSEMBLER_NAME (t));
496 if (TREE_CODE (t) == FUNCTION_DECL)
498 ggc_mark_tree (DECL_SAVED_TREE (t));
499 ggc_mark_tree (DECL_INLINED_FNS (t));
500 if (DECL_SAVED_INSNS (t))
501 ggc_mark_struct_function (DECL_SAVED_INSNS (t));
503 (*lang_hooks.mark_tree) (t);
504 break;
506 case 't': /* A type node. */
507 ggc_mark_tree (TYPE_SIZE (t));
508 ggc_mark_tree (TYPE_SIZE_UNIT (t));
509 ggc_mark_tree (TYPE_ATTRIBUTES (t));
510 ggc_mark_tree (TYPE_VALUES (t));
511 ggc_mark_tree (TYPE_POINTER_TO (t));
512 ggc_mark_tree (TYPE_REFERENCE_TO (t));
513 ggc_mark_tree (TYPE_NAME (t));
514 ggc_mark_tree (TYPE_MIN_VALUE (t));
515 ggc_mark_tree (TYPE_MAX_VALUE (t));
516 ggc_mark_tree (TYPE_NEXT_VARIANT (t));
517 ggc_mark_tree (TYPE_MAIN_VARIANT (t));
518 ggc_mark_tree (TYPE_BINFO (t));
519 ggc_mark_tree (TYPE_CONTEXT (t));
520 (*lang_hooks.mark_tree) (t);
521 break;
523 case 'b': /* A lexical block. */
524 ggc_mark_tree (BLOCK_VARS (t));
525 ggc_mark_tree (BLOCK_SUBBLOCKS (t));
526 ggc_mark_tree (BLOCK_SUPERCONTEXT (t));
527 ggc_mark_tree (BLOCK_ABSTRACT_ORIGIN (t));
528 break;
530 case 'c': /* A constant. */
531 ggc_mark_rtx (TREE_CST_RTL (t));
532 break;
534 case 'r': case '<': case '1':
535 case '2': case 'e': case 's': /* Expressions. */
537 int i = TREE_CODE_LENGTH (TREE_CODE (t));
538 int first_rtl = first_rtl_op (TREE_CODE (t));
540 while (--i >= 0)
542 if (i >= first_rtl)
543 ggc_mark_rtx ((rtx) TREE_OPERAND (t, i));
544 else
545 ggc_mark_tree (TREE_OPERAND (t, i));
547 break;
550 case 'x':
551 (*lang_hooks.mark_tree) (t);
552 break;
557 /* Mark all the elements of the varray V, which contains rtxs. */
559 void
560 ggc_mark_rtx_varray (v)
561 varray_type v;
563 int i;
565 if (v)
566 for (i = v->num_elements - 1; i >= 0; --i)
567 ggc_mark_rtx (VARRAY_RTX (v, i));
570 /* Mark all the elements of the varray V, which contains trees. */
572 void
573 ggc_mark_tree_varray (v)
574 varray_type v;
576 int i;
578 if (v)
579 for (i = v->num_elements - 1; i >= 0; --i)
580 ggc_mark_tree (VARRAY_TREE (v, i));
583 /* Mark the hash table-entry HE. Its key field is really a tree. */
585 static bool
586 ggc_mark_tree_hash_table_entry (he, k)
587 struct hash_entry *he;
588 hash_table_key k ATTRIBUTE_UNUSED;
590 ggc_mark_tree ((tree) he->key);
591 return true;
594 /* Mark all the elements of the hash-table H, which contains trees. */
596 void
597 ggc_mark_tree_hash_table (ht)
598 struct hash_table *ht;
600 hash_traverse (ht, ggc_mark_tree_hash_table_entry, /*info=*/0);
603 /* Type-correct function to pass to ggc_add_root. It just forwards
604 *ELT (which is an rtx) to ggc_mark_rtx. */
606 static void
607 ggc_mark_rtx_ptr (elt)
608 void *elt;
610 ggc_mark_rtx (*(rtx *) elt);
613 /* Type-correct function to pass to ggc_add_root. It just forwards
614 *ELT (which is a tree) to ggc_mark_tree. */
616 static void
617 ggc_mark_tree_ptr (elt)
618 void *elt;
620 ggc_mark_tree (*(tree *) elt);
623 /* Type-correct function to pass to ggc_add_root. It just forwards
624 ELT (which is really a varray_type *) to ggc_mark_rtx_varray. */
626 static void
627 ggc_mark_rtx_varray_ptr (elt)
628 void *elt;
630 ggc_mark_rtx_varray (*(varray_type *) elt);
633 /* Type-correct function to pass to ggc_add_root. It just forwards
634 ELT (which is really a varray_type *) to ggc_mark_tree_varray. */
636 static void
637 ggc_mark_tree_varray_ptr (elt)
638 void *elt;
640 ggc_mark_tree_varray (*(varray_type *) elt);
643 /* Type-correct function to pass to ggc_add_root. It just forwards
644 ELT (which is really a struct hash_table **) to
645 ggc_mark_tree_hash_table. */
647 static void
648 ggc_mark_tree_hash_table_ptr (elt)
649 void *elt;
651 ggc_mark_tree_hash_table (*(struct hash_table **) elt);
654 /* Allocate a block of memory, then clear it. */
655 void *
656 ggc_alloc_cleared (size)
657 size_t size;
659 void *buf = ggc_alloc (size);
660 memset (buf, 0, size);
661 return buf;
664 /* Print statistics that are independent of the collector in use. */
665 #define SCALE(x) ((unsigned long) ((x) < 1024*10 \
666 ? (x) \
667 : ((x) < 1024*1024*10 \
668 ? (x) / 1024 \
669 : (x) / (1024*1024))))
670 #define LABEL(x) ((x) < 1024*10 ? ' ' : ((x) < 1024*1024*10 ? 'k' : 'M'))
672 void
673 ggc_print_common_statistics (stream, stats)
674 FILE *stream;
675 ggc_statistics *stats;
677 int code;
679 /* Set the pointer so that during collection we will actually gather
680 the statistics. */
681 ggc_stats = stats;
683 /* Then do one collection to fill in the statistics. */
684 ggc_collect ();
686 /* Total the statistics. */
687 for (code = 0; code < MAX_TREE_CODES; ++code)
689 stats->total_num_trees += stats->num_trees[code];
690 stats->total_size_trees += stats->size_trees[code];
692 for (code = 0; code < NUM_RTX_CODE; ++code)
694 stats->total_num_rtxs += stats->num_rtxs[code];
695 stats->total_size_rtxs += stats->size_rtxs[code];
698 /* Print the statistics for trees. */
699 fprintf (stream, "\n%-17s%10s %16s %10s\n", "Tree",
700 "Number", "Bytes", "% Total");
701 for (code = 0; code < MAX_TREE_CODES; ++code)
702 if (ggc_stats->num_trees[code])
704 fprintf (stream, "%-17s%10u%16ld%c %10.3f\n",
705 tree_code_name[code],
706 ggc_stats->num_trees[code],
707 SCALE (ggc_stats->size_trees[code]),
708 LABEL (ggc_stats->size_trees[code]),
709 (100 * ((double) ggc_stats->size_trees[code])
710 / ggc_stats->total_size_trees));
712 fprintf (stream,
713 "%-17s%10u%16ld%c\n", "Total",
714 ggc_stats->total_num_trees,
715 SCALE (ggc_stats->total_size_trees),
716 LABEL (ggc_stats->total_size_trees));
718 /* Print the statistics for RTL. */
719 fprintf (stream, "\n%-17s%10s %16s %10s\n", "RTX",
720 "Number", "Bytes", "% Total");
721 for (code = 0; code < NUM_RTX_CODE; ++code)
722 if (ggc_stats->num_rtxs[code])
724 fprintf (stream, "%-17s%10u%16ld%c %10.3f\n",
725 rtx_name[code],
726 ggc_stats->num_rtxs[code],
727 SCALE (ggc_stats->size_rtxs[code]),
728 LABEL (ggc_stats->size_rtxs[code]),
729 (100 * ((double) ggc_stats->size_rtxs[code])
730 / ggc_stats->total_size_rtxs));
732 fprintf (stream,
733 "%-17s%10u%16ld%c\n", "Total",
734 ggc_stats->total_num_rtxs,
735 SCALE (ggc_stats->total_size_rtxs),
736 LABEL (ggc_stats->total_size_rtxs));
738 /* Don't gather statistics any more. */
739 ggc_stats = NULL;