X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/d08290769c798befc27e9f8bbc3f1a3da12d1f08..6617622c9aaa6ec3a9de5b0867421e2849b68b2f:/lib/lbitset.c
diff --git a/lib/lbitset.c b/lib/lbitset.c
index 2e5b2081..9a6fc0ae 100644
--- a/lib/lbitset.c
+++ b/lib/lbitset.c
@@ -1,10 +1,10 @@
/* Functions to support link list bitsets.
- Copyright (C) 2002, 2003 Free Software Foundation, Inc.
+ Copyright (C) 2002, 2003, 2004, 2006 Free Software Foundation, Inc.
Contributed by Michael Hayes (m.hayes@elec.canterbury.ac.nz).
- This program is free software; you can redistribute it and/or modify
+ This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
+ the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
@@ -13,19 +13,17 @@
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
-*/
+ along with this program. If not, see . */
-#ifdef HAVE_CONFIG_H
-#include "config.h"
-#endif
+#include
#include "lbitset.h"
+
#include "obstack.h"
#include
#include
#include
+#include
/* This file implements linked-list bitsets. These bitsets can be of
arbitrary length and are more efficient than arrays of bits for
@@ -40,7 +38,10 @@
/* Number of words to use for each element. The larger the value the
greater the size of the cache and the shorter the time to find a given bit
but the more memory wasted for sparse bitsets and the longer the time
- to search for set bits. */
+ to search for set bits.
+
+ The routines that dominate timing profiles are lbitset_elt_find
+ and lbitset_elt_link, especially when accessing the bits randomly. */
#define LBITSET_ELT_WORDS 2
@@ -50,7 +51,7 @@ typedef bitset_word lbitset_word;
/* Number of bits stored in each element. */
#define LBITSET_ELT_BITS \
- ((unsigned) (LBITSET_ELT_WORDS * LBITSET_WORD_BITS))
+ ((unsigned int) (LBITSET_ELT_WORDS * LBITSET_WORD_BITS))
/* Lbitset element. We use an array of bits for each element.
These are linked together in a doubly-linked list. */
@@ -74,7 +75,7 @@ static struct obstack lbitset_obstack;
static bool lbitset_obstack_init = false;
static lbitset_elt *lbitset_free_list; /* Free list of bitset elements. */
-extern void debug_lbitset PARAMS ((bitset));
+extern void debug_lbitset (bitset);
#define LBITSET_CURRENT1(X) \
((lbitset_elt *) (void *) ((char *) (X) - offsetof (lbitset_elt, words)))
@@ -117,15 +118,13 @@ lbitset_elt_alloc (void)
#define OBSTACK_CHUNK_FREE free
#endif
-#if !defined(__GNUC__) || (__GNUC__ < 2)
+#if ! defined __GNUC__ || __GNUC__ < 2
#define __alignof__(type) 0
#endif
obstack_specify_allocation (&lbitset_obstack, OBSTACK_CHUNK_SIZE,
__alignof__ (lbitset_elt),
- (void *(*)PARAMS ((long)))
OBSTACK_CHUNK_ALLOC,
- (void (*)PARAMS ((void *)))
OBSTACK_CHUNK_FREE);
}
@@ -361,6 +360,9 @@ lbitset_elt_find (bitset bset, bitset_windex windex,
switch (mode)
{
+ default:
+ abort ();
+
case LBITSET_FIND:
return 0;
@@ -374,9 +376,6 @@ lbitset_elt_find (bitset bset, bitset_windex windex,
case LBITSET_SUBST:
return &lbitset_zero_elts[0];
-
- default:
- abort ();
}
}
@@ -502,21 +501,15 @@ lbitset_copy_cmp (bitset dst, bitset src)
}
-/* Return size in bits of bitset SRC. */
static bitset_bindex
-lbitset_size (bitset src)
+lbitset_resize (bitset src, bitset_bindex size)
{
- lbitset_elt *elt;
-
- elt = LBITSET_TAIL (src);
- if (!elt)
- return 0;
+ BITSET_NBITS_ (src) = size;
- /* Return current size of bitset in bits. */
- return (elt->index + LBITSET_ELT_WORDS) * BITSET_WORD_BITS;
+ /* Need to prune any excess bits. FIXME. */
+ return size;
}
-
/* Set bit BITNO in bitset DST. */
static void
lbitset_set (bitset dst, bitset_bindex bitno)
@@ -867,8 +860,48 @@ lbitset_list (bitset bset, bitset_bindex *list,
static bool
lbitset_empty_p (bitset dst)
{
- lbitset_weed (dst);
- return !LBITSET_HEAD (dst);
+ lbitset_elt *elt;
+ lbitset_elt *next;
+
+ for (elt = LBITSET_HEAD (dst); elt; elt = next)
+ {
+ next = elt->next;
+ if (!lbitset_elt_zero_p (elt))
+ return 0;
+ /* Weed as we go. */
+ lbitset_elt_unlink (dst, elt);
+ }
+
+ return 1;
+}
+
+
+/* Ensure that any unused bits within the last element are clear. */
+static inline void
+lbitset_unused_clear (bitset dst)
+{
+ unsigned int last_bit;
+ bitset_bindex n_bits;
+
+ n_bits = BITSET_SIZE_ (dst);
+ last_bit = n_bits % LBITSET_ELT_BITS;
+
+ if (last_bit)
+ {
+ lbitset_elt *elt;
+ bitset_windex windex;
+ bitset_word *srcp;
+
+ elt = LBITSET_TAIL (dst);
+ srcp = elt->words;
+ windex = n_bits / BITSET_WORD_BITS;
+
+ srcp[windex - elt->index] &= ((bitset_word) 1 << last_bit) - 1;
+ windex++;
+
+ for (; (windex - elt->index) < LBITSET_ELT_WORDS; windex++)
+ srcp[windex - elt->index] = 0;
+ }
}
@@ -883,18 +916,17 @@ lbitset_ones (bitset dst)
bitset! It makes a sparse bitset become dense. An alternative
is to have a flag that indicates that the bitset stores the
complement of what it indicates. */
- elt = LBITSET_TAIL (dst);
- /* Ignore empty set. */
- if (!elt)
- return;
- windex = elt->index;
+ windex = (BITSET_SIZE_ (dst) + BITSET_WORD_BITS - 1) / BITSET_WORD_BITS;
+
for (i = 0; i < windex; i += LBITSET_ELT_WORDS)
{
/* Create new elements if they cannot be found. */
elt = lbitset_elt_find (dst, i, LBITSET_CREATE);
memset (elt->words, -1, sizeof (elt->words));
}
+
+ lbitset_unused_clear (dst);
}
@@ -911,11 +943,9 @@ lbitset_not (bitset dst, bitset src)
/* This is another unfriendly operation for a linked list
bitset! */
elt = LBITSET_TAIL (dst);
- /* Ignore empty set. */
- if (!elt)
- return;
- windex = elt->index;
+ windex = (BITSET_SIZE_ (dst) + BITSET_WORD_BITS - 1) / BITSET_WORD_BITS;
+
for (i = 0; i < windex; i += LBITSET_ELT_WORDS)
{
/* Create new elements for dst if they cannot be found
@@ -926,6 +956,7 @@ lbitset_not (bitset dst, bitset src)
for (j = 0; j < LBITSET_ELT_WORDS; j++)
delt->words[j] = ~selt->words[j];
}
+ lbitset_unused_clear (dst);
lbitset_weed (dst);
return;
}
@@ -1083,6 +1114,9 @@ lbitset_op3_cmp (bitset dst, bitset src1, bitset src2, enum bitset_ops op)
dstp = dtmp->words;
switch (op)
{
+ default:
+ abort ();
+
case BITSET_OP_OR:
for (i = 0; i < LBITSET_ELT_WORDS; i++, dstp++)
{
@@ -1134,9 +1168,6 @@ lbitset_op3_cmp (bitset dst, bitset src1, bitset src2, enum bitset_ops op)
}
}
break;
-
- default:
- abort ();
}
if (!lbitset_elt_zero_p (dtmp))
@@ -1280,7 +1311,8 @@ struct bitset_vtable lbitset_vtable = {
lbitset_reset,
bitset_toggle_,
lbitset_test,
- lbitset_size,
+ lbitset_resize,
+ bitset_size_,
bitset_count_,
lbitset_empty_p,
lbitset_ones,
@@ -1323,6 +1355,7 @@ lbitset_bytes (bitset_bindex n_bits ATTRIBUTE_UNUSED)
bitset
lbitset_init (bitset bset, bitset_bindex n_bits ATTRIBUTE_UNUSED)
{
+ BITSET_NBITS_ (bset) = n_bits;
bset->b.vtable = &lbitset_vtable;
return bset;
}
@@ -1352,7 +1385,7 @@ debug_lbitset (bitset bset)
for (elt = LBITSET_HEAD (bset); elt; elt = elt->next)
{
- fprintf (stderr, "Elt %lu\n", (unsigned long) elt->index);
+ fprintf (stderr, "Elt %lu\n", (unsigned long int) elt->index);
for (i = 0; i < LBITSET_ELT_WORDS; i++)
{
unsigned int j;