mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-30 08:40:07 +00:00
88 lines
2.3 KiB
C
88 lines
2.3 KiB
C
|
/* e_hypotf.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.
|
||
|
|
* ====================================================
|
||
|
|
*/
|
||
|
|
|
||
|
|
#if defined(LIBM_SCCS) && !defined(lint)
|
||
|
|
static char rcsid[] = "$NetBSD: e_hypotf.c,v 1.5 1995/05/12 04:57:30 jtc Exp $";
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#include "math.h"
|
||
|
|
#include "math_private.h"
|
||
|
|
|
||
|
|
#ifdef __STDC__
|
||
|
|
float __ieee754_hypotf(float x, float y)
|
||
|
|
#else
|
||
|
|
float __ieee754_hypot(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 &= 0x7fffffff;
|
||
|
|
GET_FLOAT_WORD(hb,y);
|
||
|
|
hb &= 0x7fffffff;
|
||
|
|
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)>0xf000000) {return a+b;} /* x/y > 2**30 */
|
||
|
|
k=0;
|
||
|
|
if(ha > 0x58800000) { /* a>2**50 */
|
||
|
|
if(ha >= 0x7f800000) { /* Inf or NaN */
|
||
|
|
w = a+b; /* for sNaN */
|
||
|
|
if(ha == 0x7f800000) w = a;
|
||
|
|
if(hb == 0x7f800000) w = b;
|
||
|
|
return w;
|
||
|
|
}
|
||
|
|
/* scale a and b by 2**-60 */
|
||
|
|
ha -= 0x5d800000; hb -= 0x5d800000; k += 60;
|
||
|
|
SET_FLOAT_WORD(a,ha);
|
||
|
|
SET_FLOAT_WORD(b,hb);
|
||
|
|
}
|
||
|
|
if(hb < 0x26800000) { /* b < 2**-50 */
|
||
|
|
if(hb <= 0x007fffff) { /* subnormal b or 0 */
|
||
|
|
if(hb==0) return a;
|
||
|
|
SET_FLOAT_WORD(t1,0x3f000000); /* 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&0xfffff000);
|
||
|
|
t2 = a-t1;
|
||
|
|
w = __ieee754_sqrtf(t1*t1-(b*(-b)-t2*(a+t1)));
|
||
|
|
} else {
|
||
|
|
a = a+a;
|
||
|
|
SET_FLOAT_WORD(y1,hb&0xfffff000);
|
||
|
|
y2 = b - y1;
|
||
|
|
SET_FLOAT_WORD(t1,ha+0x00800000);
|
||
|
|
t2 = a - t1;
|
||
|
|
w = __ieee754_sqrtf(t1*y1-(w*(-w)-(t1*y2+t2*b)));
|
||
|
|
}
|
||
|
|
if(k!=0) {
|
||
|
|
SET_FLOAT_WORD(t1,0x3f800000+(k<<23));
|
||
|
|
return t1*w;
|
||
|
|
} else return w;
|
||
|
|
}
|