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/* origin: FreeBSD /usr/src/lib/msun/src/e_hypotf.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 "libm.h"
float hypotf(float x, float y)
{
float a,b,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;
}
a = fabsf(a);
b = fabsf(b);
if (ha - hb > 0xf000000) /* x/y > 2**30 */
return a+b;
k = 0;
if (ha > 0x58800000) { /* a > 2**50 */
if(ha >= 0x7f800000) { /* Inf or NaN */
/* Use original arg order iff result is NaN; quieten sNaNs. */
w = fabsf(x+0.0f) - fabsf(y+0.0f);
if (ha == 0x7f800000) w = a;
if (hb == 0x7f800000) w = b;
return w;
}
/* scale a and b by 2**-68 */
ha -= 0x22000000; hb -= 0x22000000; k += 68;
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, 0x7e800000); /* t1 = 2^126 */
b *= t1;
a *= t1;
k -= 126;
} else { /* scale a and b by 2^68 */
ha += 0x22000000; /* a *= 2^68 */
hb += 0x22000000; /* b *= 2^68 */
k -= 68;
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 = 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)&0xfffff000);
t2 = a - t1;
w = sqrtf(t1*y1-(w*(-w)-(t1*y2+t2*b)));
}
if (k)
w = scalbnf(w, k);
return w;
}
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