Subversion Repositories or1k

/* ef_hypot.c -- float version of e_hypot.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"

#ifdef __STDC__

        float __ieee754_hypotf(float x, float y)

#else

        float __ieee754_hypotf(x,y)

        float x, y;

#endif

{

        float a=x,b=y,t1,t2,y1,y2,w;

        __int32_t j,k,ha,hb;

        GET_FLOAT_WORD(ha,x);

        ha &= 0x7fffffffL;

        GET_FLOAT_WORD(hb,y);

        hb &= 0x7fffffffL;

        if(hb > ha) {a=y;b=x;j=ha; ha=hb;hb=j;} else {a=x;b=y;}

        SET_FLOAT_WORD(a,ha);   /* a <- |a| */

        SET_FLOAT_WORD(b,hb);   /* b <- |b| */

        if((ha-hb)>0xf000000L) {return a+b;} /* x/y > 2**30 */

        k=0;

        if(ha > 0x58800000L) {  /* a>2**50 */

           if(ha >= 0x7f800000L) {      /* Inf or NaN */

               w = a+b;                 /* for sNaN */

               if(ha == 0x7f800000L) w = a;

               if(hb == 0x7f800000L) w = b;

               return w;

           }

           /* scale a and b by 2**-60 */

           ha -= 0x5d800000L; hb -= 0x5d800000L;        k += 60;

           SET_FLOAT_WORD(a,ha);

           SET_FLOAT_WORD(b,hb);

        }

        if(hb < 0x26800000L) {  /* b < 2**-50 */

            if(hb <= 0x007fffffL) {     /* subnormal b or 0 */

                if(hb==0) return a;

                SET_FLOAT_WORD(t1,0x3f000000L); /* t1=2^126 */

                b *= t1;

                a *= t1;

                k -= 126;

            } else {            /* scale a and b by 2^60 */

                ha += 0x5d800000;       /* a *= 2^60 */

                hb += 0x5d800000;       /* b *= 2^60 */

                k -= 60;

                SET_FLOAT_WORD(a,ha);

                SET_FLOAT_WORD(b,hb);

            }

        }

    /* medium size a and b */

        w = a-b;

        if (w>b) {

            SET_FLOAT_WORD(t1,ha&0xfffff000L);

            t2 = a-t1;

            w  = __ieee754_sqrtf(t1*t1-(b*(-b)-t2*(a+t1)));

        } else {

            a  = a+a;

            SET_FLOAT_WORD(y1,hb&0xfffff000L);

            y2 = b - y1;

            SET_FLOAT_WORD(t1,ha+0x00800000L);

            t2 = a - t1;

            w  = __ieee754_sqrtf(t1*y1-(w*(-w)-(t1*y2+t2*b)));

        }

        if(k!=0) {

            SET_FLOAT_WORD(t1,0x3f800000L+(k<<23));

            return t1*w;

        } else return w;

}