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/* CGEN generic opcode support.

   Copyright 2002, 2005, 2007, 2009

   Free Software Foundation, Inc.

   This file is part of libopcodes.

   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

   the Free Software Foundation; either version 3, or (at your option)

   any later version.

   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];

}