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/* origin: FreeBSD /usr/src/lib/msun/src/s_sin.c */
/*
* ====================================================
* 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.
* ====================================================
*/
#define _GNU_SOURCE
#include "libm.h"
void sincos(double x, double *sin, double *cos)
{
double y[2], s, c;
uint32_t ix;
unsigned n;
GET_HIGH_WORD(ix, x);
ix &= 0x7fffffff;
/* |x| ~< pi/4 */
if (ix <= 0x3fe921fb) {
/* if |x| < 2**-27 * sqrt(2) */
if (ix < 0x3e46a09e) {
/* raise inexact if x!=0 and underflow if subnormal */
FORCE_EVAL(ix < 0x00100000 ? x/0x1p120f : x+0x1p120f);
*sin = x;
*cos = 1.0;
return;
}
*sin = __sin(x, 0.0, 0);
*cos = __cos(x, 0.0);
return;
}
/* sincos(Inf or NaN) is NaN */
if (ix >= 0x7ff00000) {
*sin = *cos = x - x;
return;
}
/* argument reduction needed */
n = __rem_pio2(x, y);
s = __sin(y[0], y[1], 1);
c = __cos(y[0], y[1]);
switch (n&3) {
case 0:
*sin = s;
*cos = c;
break;
case 1:
*sin = c;
*cos = -s;
break;
case 2:
*sin = -s;
*cos = -c;
break;
case 3:
default:
*sin = -c;
*cos = s;
break;
}
}
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