/*
 *	UCW Library -- Bit Array Operations
 *
 *	(c) 2003--2006 Martin Mares <mj@ucw.cz>
 *	(c) 2012 Pavel Charvat <pchar@ucw.cz>
 *
 *	This software may be freely distributed and used according to the terms
 *	of the GNU Lesser General Public License.
 */

#ifndef _UCW_BITARRAY_H
#define _UCW_BITARRAY_H

#include <string.h>

#ifdef CONFIG_UCW_CLEAN_ABI
#define bit_array_count_bits ucw_bit_array_count_bits
#define bit_array_xrealloc ucw_bit_array_xrealloc
#endif

typedef u32 *bitarray_t; // Must be initialized by bit_array_xmalloc(), bit_array_zero() or bit_array_set_all()

#define BIT_ARRAY_WORDS(n) (((n)+31)/32)
#define BIT_ARRAY_BYTES(n) (4*BIT_ARRAY_WORDS(n))
#define BIT_ARRAY(name,size) u32 name[BIT_ARRAY_WORDS(size)]

static inline bitarray_t bit_array_xmalloc(uint n)
{
  return xmalloc(BIT_ARRAY_BYTES(n));
}

bitarray_t bit_array_xrealloc(bitarray_t a, uint old_n, uint new_n);

static inline bitarray_t bit_array_xmalloc_zero(uint n)
{
  return xmalloc_zero(BIT_ARRAY_BYTES(n));
}

static inline void bit_array_zero(bitarray_t a, uint n)
{
  bzero(a, BIT_ARRAY_BYTES(n));
}

static inline void bit_array_set_all(bitarray_t a, uint n)
{
  uint w = n / 32;
  memset(a, 255, w * 4);
  uint m = n & 31;
  if (m)
    a[w] = (1U << m) - 1;
}

static inline void bit_array_set(bitarray_t a, uint i)
{
  a[i/32] |= (1 << (i%32));
}

static inline void bit_array_clear(bitarray_t a, uint i)
{
  a[i/32] &= ~(1 << (i%32));
}

static inline void bit_array_assign(bitarray_t a, uint i, uint x)
{
  if (x)
    bit_array_set(a, i);
  else
    bit_array_clear(a, i);
}

static inline uint bit_array_isset(bitarray_t a, uint i)
{
  return a[i/32] & (1 << (i%32));
}

static inline uint bit_array_get(bitarray_t a, uint i)
{
  return !! bit_array_isset(a, i);
}

static inline uint bit_array_test_and_set(bitarray_t a, uint i)
{
  uint t = bit_array_isset(a, i);
  bit_array_set(a, i);
  return t;
}

static inline uint bit_array_test_and_clear(bitarray_t a, uint i)
{
  uint t = bit_array_isset(a, i);
  bit_array_clear(a, i);
  return t;
}

uint bit_array_count_bits(bitarray_t a, uint n);

/* Iterate over all set bits */
#define BIT_ARRAY_FISH_BITS_BEGIN(var,ary,size)					\
  for (uint var##_hi=0; var##_hi < BIT_ARRAY_WORDS(size); var##_hi++)		\
    {										\
      u32 var##_cur = ary[var##_hi];						\
      for (uint var = 32 * var##_hi; var##_cur; var++, var##_cur >>= 1)		\
        if (var##_cur & 1)							\
	  do

#define BIT_ARRAY_FISH_BITS_END							\
	  while (0);								\
    }

#endif