/home/jaouen/pok_official/pok/trunk/libpok/libm/powf.c

/*
 *                               POK header
 * 
 * The following file is a part of the POK project. Any modification should
 * made according to the POK licence. You CANNOT use this file or a part of
 * this file is this part of a file for your own project
 *
 * For more information on the POK licence, please see our LICENCE FILE
 *
 * Please follow the coding guidelines described in doc/CODING_GUIDELINES
 *
 *                                      Copyright (c) 2007-2009 POK team 
 *
 * Created by julien on Fri Jan 30 14:41:34 2009 
 */

/* w_powf.c -- float version of w_pow.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.
 * ====================================================
 */

#ifdef POK_NEEDS_LIBMATH

/*
 * wrapper powf(x,y) return x**y
 */

#include <libm.h>
#include "math_private.h"


float
powf(float x, float y)  /* wrapper powf */
{
#ifdef _IEEE_LIBM
        return  __ieee754_powf(x,y);
#else
        float z;
        z=__ieee754_powf(x,y);
        if(_LIB_VERSION == _IEEE_|| isnanf(y)) return z;
        if(isnanf(x)) {
            if(y==(float)0.0)
                /* powf(NaN,0.0) */
                return (float)__kernel_standard((double)x,(double)y,142);
            else
                return z;
        }
        if(x==(float)0.0){
            if(y==(float)0.0)
                /* powf(0.0,0.0) */
                return (float)__kernel_standard((double)x,(double)y,120);
            if(finitef(y)&&y<(float)0.0)
                /* powf(0.0,negative) */
                return (float)__kernel_standard((double)x,(double)y,123);
            return z;
        }
        if(!finitef(z)) {
            if(finitef(x)&&finitef(y)) {
                if(isnanf(z))
                    /* powf neg**non-int */
                    return (float)__kernel_standard((double)x,(double)y,124);
                else
                    /* powf overflow */
                    return (float)__kernel_standard((double)x,(double)y,121);
            }
        }
        if(z==(float)0.0&&finitef(x)&&finitef(y))
            /* powf underflow */
            return (float)__kernel_standard((double)x,(double)y,122);
        return z;
#endif
}

#endif