/*--------------------------------------------------------------------

 *© Portions copyright (c) 2006 Nokia Corporation.  All rights reserved.

 *--------------------------------------------------------------------

*/

/*

 * From: @(#)s_ilogb.c 5.1 93/09/24

 * ====================================================

 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.

 *

 * Developed at SunPro, a Sun Microsystems, Inc. business.

 * Permission to use, copy, modify, and distribute this

 * software is freely granted, provided that this notice

 * is preserved.

 * ====================================================

 */

#ifndef __SYMBIAN32__

#ifndef lint

static char rcsid[] = "$FreeBSD: src/lib/msun/src/s_ilogbl.c,v 1.1 2004/10/11 18:13:52 stefanf Exp $";

#endif

#endif //__SYMBIAN32__

#include <float.h>

#include <limits.h>

#include <math.h>

#include "fpmath.h"

EXPORT_C int

ilogbl(long double x)

{

	union IEEEl2bits u;

	unsigned long m;

	int b;

	u.e = x;

	if (u.bits.exp == 0) {

		if ((u.bits.manl | u.bits.manh) == 0)

			return (FP_ILOGB0);

		/* denormalized */

		if (u.bits.manh == 0) {

			m = 1lu << (LDBL_MANL_SIZE - 1);

			for (b = LDBL_MANH_SIZE; !(u.bits.manl & m); m >>= 1)

				b++;

		} else {

			m = 1lu << (LDBL_MANH_SIZE - 1);

			for (b = 0; !(u.bits.manh & m); m >>= 1)

				b++;

		}

#ifdef LDBL_IMPLICIT_NBIT

		b++;

#endif

		return (LDBL_MIN_EXP - b - 1);

	} else if (u.bits.exp < (LDBL_MAX_EXP << 1) - 1)

		return (u.bits.exp - LDBL_MAX_EXP + 1);

	else if (u.bits.manl != 0 || u.bits.manh != 0)

		return (FP_ILOGBNAN);

	else

		return (INT_MAX);

}