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/* See the import.pl script for potential modifications */
/* e_atan2f.c -- Simple version of e_atan2.c.
* Conversion to Simple 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_atan2f.c,v 1.4f 1995/05/10 20:44:53 jtc Exp $";
#endif
#include "SMath.h"
#include "math_private.h"
namespace streflop_libm {
#ifdef __STDC__
static const Simple
#else
static Simple
#endif
tiny = 1.0e-30f,
zero = 0.0f,
pi_o_4 = 7.8539818525e-01f, /* 0x3f490fdb */
pi_o_2 = 1.5707963705e+00f, /* 0x3fc90fdb */
pi = 3.1415927410e+00f, /* 0x40490fdb */
pi_lo = -8.7422776573e-08f; /* 0xb3bbbd2e */
#ifdef __STDC__
Simple __ieee754_atan2f(Simple y, Simple x)
#else
Simple __ieee754_atan2f(y,x)
Simple y,x;
#endif
{
Simple z;
int32_t k,m,hx,hy,ix,iy;
GET_FLOAT_WORD(hx,x);
ix = hx&0x7fffffff;
GET_FLOAT_WORD(hy,y);
iy = hy&0x7fffffff;
if((ix>0x7f800000)||
(iy>0x7f800000)) /* x or y is NaN */
return x+y;
if(hx==0x3f800000) return __atanf(y); /* x=1.0f */
m = ((hy>>31)&1)|((hx>>30)&2); /* 2*sign(x)+sign(y) */
/* when y = 0 */
if(iy==0) {
switch(m) {
case 0:
case 1: return y; /* atan(+-0,+anything)=+-0 */
case 2: return pi+tiny;/* atan(+0,-anything) = pi */
case 3: return -pi-tiny;/* atan(-0,-anything) =-pi */
}
}
/* when x = 0 */
if(ix==0) return (hy<0)? -pi_o_2-tiny: pi_o_2+tiny;
/* when x is INF */
if(ix==0x7f800000) {
if(iy==0x7f800000) {
switch(m) {
case 0: return pi_o_4+tiny;/* atan(+INF,+INF) */
case 1: return -pi_o_4-tiny;/* atan(-INF,+INF) */
case 2: return (Simple)3.0f*pi_o_4+tiny;/*atan(+INF,-INF)*/
case 3: return (Simple)-3.0f*pi_o_4-tiny;/*atan(-INF,-INF)*/
}
} else {
switch(m) {
case 0: return zero ; /* atan(+...,+INF) */
case 1: return -zero ; /* atan(-...,+INF) */
case 2: return pi+tiny ; /* atan(+...,-INF) */
case 3: return -pi-tiny ; /* atan(-...,-INF) */
}
}
}
/* when y is INF */
if(iy==0x7f800000) return (hy<0)? -pi_o_2-tiny: pi_o_2+tiny;
/* compute y/x */
k = (iy-ix)>>23;
if(k > 60) z=pi_o_2+(Simple)0.5f*pi_lo; /* |y/x| > 2**60 */
else if(hx<0&&k<-60) z=0.0f; /* |y|/x < -2**60 */
else z=__atanf(fabsf(y/x)); /* safe to do y/x */
switch (m) {
case 0: return z ; /* atan(+,+) */
case 1: {
u_int32_t zh;
GET_FLOAT_WORD(zh,z);
SET_FLOAT_WORD(z,zh ^ 0x80000000);
}
return z ; /* atan(-,+) */
case 2: return pi-(z-pi_lo);/* atan(+,-) */
default: /* case 3 */
return (z-pi_lo)-pi;/* atan(-,-) */
}
}
}
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