jpc_math.h

/*
 * Copyright (c) 2001-2002 Michael David Adams.
 * All rights reserved.
 */

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#ifndef	JPC_MATH_H
#define	JPC_MATH_H

/******************************************************************************\
* Includes
\******************************************************************************/

#include	<assert.h>

/******************************************************************************\
* Macros
\******************************************************************************/

/* Compute the floor of the quotient of two integers. */
#define	JPC_FLOORDIV(x, y)	((x) / (y))

/* Compute the ceiling of the quotient of two integers. */
#define	JPC_CEILDIV(x, y)	(((x) + (y) - 1) / (y))

/* Compute the floor of (x / 2^y). */
#define	JPC_FLOORDIVPOW2(x, y)	((x) >> (y))

/* Compute the ceiling of (x / 2^y). */
#define	JPC_CEILDIVPOW2(x, y)	(((x) + (1 << (y)) - 1) >> (y))

/******************************************************************************\
* Functions.
\******************************************************************************/

/* Calculate the bit position of the first leading one in a nonnegative
  integer. */
int jpc_firstone(int x);

/* Calculate the integer quantity floor(log2(x)), where x is a positive
  integer. */
int jpc_floorlog2(int x);

#endif