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binutils-gdb/opcodes/cgen-bitset.c

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/* CGEN generic opcode support.
Copyright (C) 2002-2017 Free Software Foundation, Inc.
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This file is part of libopcodes.
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This library is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3, or (at your option)
any later version.
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It 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, write to the Free Software Foundation, Inc.,
51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */
/* Functions for manipulating CGEN_BITSET. */
#include "libiberty.h"
#include "cgen/bitset.h"
#include <string.h>
/* Create a bit mask. */
CGEN_BITSET *
cgen_bitset_create (unsigned bit_count)
{
CGEN_BITSET * mask = xmalloc (sizeof (* mask));
cgen_bitset_init (mask, bit_count);
return mask;
}
/* Initialize an existing bit mask. */
void
cgen_bitset_init (CGEN_BITSET * mask, unsigned bit_count)
{
if (! mask)
return;
mask->length = (bit_count / 8) + 1;
mask->bits = xmalloc (mask->length);
cgen_bitset_clear (mask);
}
/* Clear the bits of a bit mask. */
void
cgen_bitset_clear (CGEN_BITSET * mask)
{
unsigned i;
if (! mask)
return;
for (i = 0; i < mask->length; ++i)
mask->bits[i] = 0;
}
/* Add a bit to a bit mask. */
void
cgen_bitset_add (CGEN_BITSET * mask, unsigned bit_num)
{
int byte_ix, bit_ix;
int bit_mask;
if (! mask)
return;
byte_ix = bit_num / 8;
bit_ix = bit_num % 8;
bit_mask = 1 << (7 - bit_ix);
mask->bits[byte_ix] |= bit_mask;
}
/* Set a bit mask. */
void
cgen_bitset_set (CGEN_BITSET * mask, unsigned bit_num)
{
if (! mask)
return;
cgen_bitset_clear (mask);
cgen_bitset_add (mask, bit_num);
}
/* Test for a bit in a bit mask.
Returns 1 if the bit is found */
int
cgen_bitset_contains (CGEN_BITSET * mask, unsigned bit_num)
{
int byte_ix, bit_ix;
int bit_mask;
if (! mask)
return 1; /* No bit restrictions. */
byte_ix = bit_num / 8;
bit_ix = 7 - (bit_num % 8);
bit_mask = 1 << bit_ix;
return (mask->bits[byte_ix] & bit_mask) >> bit_ix;
}
/* Compare two bit masks for equality.
Returns 0 if they are equal. */
int
cgen_bitset_compare (CGEN_BITSET * mask1, CGEN_BITSET * mask2)
{
if (mask1 == mask2)
return 0;
if (! mask1 || ! mask2)
return 1;
if (mask1->length != mask2->length)
return 1;
return memcmp (mask1->bits, mask2->bits, mask1->length);
}
/* Test two bit masks for common bits.
Returns 1 if a common bit is found. */
int
cgen_bitset_intersect_p (CGEN_BITSET * mask1, CGEN_BITSET * mask2)
{
unsigned i, limit;
if (mask1 == mask2)
return 1;
if (! mask1 || ! mask2)
return 0;
limit = mask1->length < mask2->length ? mask1->length : mask2->length;
for (i = 0; i < limit; ++i)
if ((mask1->bits[i] & mask2->bits[i]))
return 1;
return 0;
}
/* Make a copy of a bit mask. */
CGEN_BITSET *
cgen_bitset_copy (CGEN_BITSET * mask)
{
CGEN_BITSET* newmask;
if (! mask)
return NULL;
newmask = cgen_bitset_create ((mask->length * 8) - 1);
memcpy (newmask->bits, mask->bits, mask->length);
return newmask;
}
/* Combine two bit masks. */
void
cgen_bitset_union (CGEN_BITSET * mask1, CGEN_BITSET * mask2,
CGEN_BITSET * result)
{
unsigned i;
if (! mask1 || ! mask2 || ! result
|| mask1->length != mask2->length
|| mask1->length != result->length)
return;
for (i = 0; i < result->length; ++i)
result->bits[i] = mask1->bits[i] | mask2->bits[i];
}