/* General bitsets.
Copyright (C) 2002-2006, 2009-2012 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
it under the terms of the GNU General Public License as published by
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,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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, see <http://www.gnu.org/licenses/>. */
#include <config.h>
#include "bitset.h"
#include <stdlib.h>
#include <string.h>
#include "abitset.h"
#include "lbitset.h"
#include "ebitset.h"
#include "vbitset.h"
#include "bitset_stats.h"
#include "obstack.h"
const char * const bitset_type_names[] = BITSET_TYPE_NAMES;
/* Return number of bytes required to create a N_BIT bitset
of TYPE. The bitset may grow to require more bytes than this. */
size_t
bitset_bytes (enum bitset_type type, bitset_bindex n_bits)
{
size_t bytes;
if (bitset_stats_enabled)
return bitset_stats_bytes ();
switch (type)
{
default:
abort ();
case BITSET_ARRAY:
bytes = abitset_bytes (n_bits);
break;
case BITSET_LIST:
bytes = lbitset_bytes (n_bits);
break;
case BITSET_TABLE:
bytes = ebitset_bytes (n_bits);
break;
case BITSET_VARRAY:
bytes = vbitset_bytes (n_bits);
break;
}
return bytes;
}
/* Initialise bitset BSET of TYPE for N_BITS. */
bitset
bitset_init (bitset bset, bitset_bindex n_bits, enum bitset_type type)
{
if (bitset_stats_enabled)
return bitset_stats_init (bset, n_bits, type);
switch (type)
{
default:
abort ();
case BITSET_ARRAY:
return abitset_init (bset, n_bits);
case BITSET_LIST:
return lbitset_init (bset, n_bits);
case BITSET_TABLE:
return ebitset_init (bset, n_bits);
case BITSET_VARRAY:
return vbitset_init (bset, n_bits);
}
}
/* Select a bitset type for a set of N_BITS and with attribute hints
specified by ATTR. For variable size bitsets, N_BITS is only a
hint and may be zero. */
enum bitset_type
bitset_type_choose (bitset_bindex n_bits ATTRIBUTE_UNUSED, unsigned int attr)
{
/* Check attributes. */
if (attr & BITSET_FIXED && attr & BITSET_VARIABLE)
abort ();
if (attr & BITSET_SPARSE && attr & BITSET_DENSE)
abort ();
/* Choose the type of bitset. Note that sometimes we will be asked
for a zero length fixed size bitset. */
/* If no attributes selected, choose a good compromise. */
if (!attr)
return BITSET_VARRAY;
if (attr & BITSET_SPARSE)
return BITSET_LIST;
if (attr & BITSET_FIXED)
return BITSET_ARRAY;
if (attr & BITSET_GREEDY)
return BITSET_TABLE;
return BITSET_VARRAY;
}
/* Create a bitset of N_BITS of type TYPE. */
bitset
bitset_alloc (bitset_bindex n_bits, enum bitset_type type)
{
size_t bytes;
bitset bset;
bytes = bitset_bytes (type, n_bits);
bset = xcalloc (1, bytes);
/* The cache is disabled until some elements are allocated. If we
have variable length arrays, then we may need to allocate a dummy
element. */
return bitset_init (bset, n_bits, type);
}
/* Create a bitset of N_BITS of type TYPE. */
bitset
bitset_obstack_alloc (struct obstack *bobstack,
bitset_bindex n_bits, enum bitset_type type)
{
size_t bytes;
bitset bset;
bytes = bitset_bytes (type, n_bits);
bset = obstack_alloc (bobstack, bytes);
memset (bset, 0, bytes);
return bitset_init (bset, n_bits, type);
}
/* Create a bitset of N_BITS and with attribute hints specified by
ATTR. */
bitset
bitset_create (bitset_bindex n_bits, unsigned int attr)
{
enum bitset_type type;
type = bitset_type_choose (n_bits, attr);
return bitset_alloc (n_bits, type);
}
/* Free bitset BSET. */
void
bitset_free (bitset bset)
{
BITSET_FREE_ (bset);
free (bset);
}
/* Free bitset BSET allocated on obstack. */
void
bitset_obstack_free (bitset bset)
{
BITSET_FREE_ (bset);
}
/* Return bitset type. */
enum bitset_type
bitset_type_get (bitset bset)
{
enum bitset_type type;
type = BITSET_TYPE_ (bset);
if (type != BITSET_STATS)
return type;
return bitset_stats_type_get (bset);
}
/* Return name of bitset type. */
const char *
bitset_type_name_get (bitset bset)
{
enum bitset_type type;
type = bitset_type_get (bset);
return bitset_type_names[type];
}
/* Find next bit set in SRC starting from and including BITNO.
Return BITSET_BINDEX_MAX if SRC empty. */
bitset_bindex
bitset_next (bitset src, bitset_bindex bitno)
{
bitset_bindex val;
bitset_bindex next = bitno;
if (!bitset_list (src, &val, 1, &next))
return BITSET_BINDEX_MAX;
return val;
}
/* Return true if both bitsets are of the same type and size. */
extern bool
bitset_compatible_p (bitset bset1, bitset bset2)
{
return BITSET_COMPATIBLE_ (bset1, bset2);
}
/* Find previous bit set in SRC starting from and including BITNO.
Return BITSET_BINDEX_MAX if SRC empty. */
bitset_bindex
bitset_prev (bitset src, bitset_bindex bitno)
{
bitset_bindex val;
bitset_bindex next = bitno;
if (!bitset_list_reverse (src, &val, 1, &next))
return BITSET_BINDEX_MAX;
return val;
}
/* Find first set bit. */
bitset_bindex
bitset_first (bitset src)
{
return bitset_next (src, 0);
}
/* Find last set bit. */
bitset_bindex
bitset_last (bitset src)
{
return bitset_prev (src, 0);
}
/* Is BITNO in SRC the only set bit? */
bool
bitset_only_set_p (bitset src, bitset_bindex bitno)
{
bitset_bindex val[2];
bitset_bindex next = 0;
if (bitset_list (src, val, 2, &next) != 1)
return false;
return val[0] == bitno;
}
/* Print contents of bitset BSET to FILE. */
static void
bitset_print (FILE *file, bitset bset, bool verbose)
{
unsigned int pos;
bitset_bindex i;
bitset_iterator iter;
if (verbose)
fprintf (file, "n_bits = %lu, set = {",
(unsigned long int) bitset_size (bset));
pos = 30;
BITSET_FOR_EACH (iter, bset, i, 0)
{
if (pos > 70)
{
fprintf (file, "\n");
pos = 0;
}
fprintf (file, "%lu ", (unsigned long int) i);
pos += 1 + (i >= 10) + (i >= 100);
};
if (verbose)
fprintf (file, "}\n");
}
/* Dump bitset BSET to FILE. */
void
bitset_dump (FILE *file, bitset bset)
{
bitset_print (file, bset, false);
}
/* Release memory associated with bitsets. */
void
bitset_release_memory (void)
{
lbitset_release_memory ();
ebitset_release_memory ();
}
/* Toggle bit BITNO in bitset BSET and the new value of the bit. */
bool
bitset_toggle_ (bitset bset, bitset_bindex bitno)
{
/* This routine is for completeness. It could be optimized if
required. */
if (bitset_test (bset, bitno))
{
bitset_reset (bset, bitno);
return false;
}
else
{
bitset_set (bset, bitno);
return true;
}
}
/* Return number of bits in bitset SRC. */
bitset_bindex
bitset_size_ (bitset src)
{
return BITSET_NBITS_ (src);
}
/* Return number of bits set in bitset SRC. */
bitset_bindex
bitset_count_ (bitset src)
{
bitset_bindex list[BITSET_LIST_SIZE];
bitset_bindex next;
bitset_bindex num;
bitset_bindex count;
/* This could be greatly sped up by adding a count method for each
bitset implementation that uses a direct technique (based on
masks) for counting the number of bits set in a word. */
next = 0;
for (count = 0; (num = bitset_list (src, list, BITSET_LIST_SIZE, &next));
count += num)
continue;
return count;
}
/* DST = SRC. Return true if DST != SRC.
This is a fallback for the case where SRC and DST are different
bitset types. */
bool
bitset_copy_ (bitset dst, bitset src)
{
bitset_bindex i;
bitset_iterator iter;
/* Convert bitset types. We assume that the DST bitset
is large enough to hold the SRC bitset. */
bitset_zero (dst);
BITSET_FOR_EACH (iter, src, i, 0)
{
bitset_set (dst, i);
};
return true;
}
/* This is a fallback for implementations that do not support
four operand operations. */
static inline bool
bitset_op4_cmp (bitset dst, bitset src1, bitset src2, bitset src3,
enum bitset_ops op)
{
bool changed = false;
bool stats_enabled_save;
bitset tmp;
/* Create temporary bitset. */
stats_enabled_save = bitset_stats_enabled;
bitset_stats_enabled = false;
tmp = bitset_alloc (0, bitset_type_get (dst));
bitset_stats_enabled = stats_enabled_save;
switch (op)
{
default:
abort ();
case BITSET_OP_OR_AND:
bitset_or (tmp, src1, src2);
changed = bitset_and_cmp (dst, src3, tmp);
break;
case BITSET_OP_AND_OR:
bitset_and (tmp, src1, src2);
changed = bitset_or_cmp (dst, src3, tmp);
break;
case BITSET_OP_ANDN_OR:
bitset_andn (tmp, src1, src2);
changed = bitset_or_cmp (dst, src3, tmp);
break;
}
bitset_free (tmp);
return changed;
}
/* DST = (SRC1 & SRC2) | SRC3. */
void
bitset_and_or_ (bitset dst, bitset src1, bitset src2, bitset src3)
{
bitset_and_or_cmp_ (dst, src1, src2, src3);
}
/* DST = (SRC1 & SRC2) | SRC3. Return non-zero if
DST != (SRC1 & SRC2) | SRC3. */
bool
bitset_and_or_cmp_ (bitset dst, bitset src1, bitset src2, bitset src3)
{
return bitset_op4_cmp (dst, src1, src2, src3, BITSET_OP_AND_OR);
}
/* DST = (SRC1 & ~SRC2) | SRC3. */
void
bitset_andn_or_ (bitset dst, bitset src1, bitset src2, bitset src3)
{
bitset_andn_or_cmp_ (dst, src1, src2, src3);
}
/* DST = (SRC1 & ~SRC2) | SRC3. Return non-zero if
DST != (SRC1 & ~SRC2) | SRC3. */
bool
bitset_andn_or_cmp_ (bitset dst, bitset src1, bitset src2, bitset src3)
{
return bitset_op4_cmp (dst, src1, src2, src3, BITSET_OP_ANDN_OR);
}
/* DST = (SRC1 | SRC2) & SRC3. */
void
bitset_or_and_ (bitset dst, bitset src1, bitset src2, bitset src3)
{
bitset_or_and_cmp_ (dst, src1, src2, src3);
}
/* DST = (SRC1 | SRC2) & SRC3. Return non-zero if
DST != (SRC1 | SRC2) & SRC3. */
bool
bitset_or_and_cmp_ (bitset dst, bitset src1, bitset src2, bitset src3)
{
return bitset_op4_cmp (dst, src1, src2, src3, BITSET_OP_OR_AND);
}
/* Function to be called from debugger to print bitset. */
void
debug_bitset (bitset bset)
{
if (bset)
bitset_print (stderr, bset, true);
}