Subversion Repositories openrisc_2011-10-31

/* sf_ilogb.c -- float version of s_ilogb.c.

 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.

 */

/*

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

 * 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.

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

 */

#include "fdlibm.h"

#include <limits.h>

#ifdef __STDC__

        int ilogbf(float x)

#else

        int ilogbf(x)

        float x;

#endif

{

        __int32_t hx,ix;

        GET_FLOAT_WORD(hx,x);

        hx &= 0x7fffffff;

        if(FLT_UWORD_IS_ZERO(hx))

            return - INT_MAX;   /* ilogb(0) = 0x80000001 */

        if(FLT_UWORD_IS_SUBNORMAL(hx)) {

            for (ix = -126,hx<<=8; hx>0; hx<<=1) ix -=1;

            return ix;

        }

        else if (!FLT_UWORD_IS_FINITE(hx)) return INT_MAX;

        else return (hx>>23)-127;

}

#ifdef _DOUBLE_IS_32BITS

#ifdef __STDC__

        int ilogb(double x)

#else

        int ilogb(x)

        double x;

#endif

{

        return ilogbf((float) x);

}

#endif /* defined(_DOUBLE_IS_32BITS) */