glibc/sysdeps/ieee754/dbl-64/s_sincos.c
Ulrich Drepper abfbdde177 Update.
1999-07-14 00:54:57 +00:00

79 lines
2.0 KiB
C

/* Compute sine and cosine of argument.
Copyright (C) 1997 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <math.h>
#include "math_private.h"
void
__sincos (double x, double *sinx, double *cosx)
{
int32_t ix;
/* High word of x. */
GET_HIGH_WORD (ix, x);
/* |x| ~< pi/4 */
ix &= 0x7fffffff;
if (ix <= 0x3fe921fb)
{
*sinx = __kernel_sin (x, 0.0, 0);
*cosx = __kernel_cos (x, 0.0);
}
else if (ix>=0x7ff00000)
{
/* sin(Inf or NaN) is NaN */
*sinx = *cosx = x - x;
}
else
{
/* Argument reduction needed. */
double y[2];
int n;
n = __ieee754_rem_pio2 (x, y);
switch (n & 3)
{
case 0:
*sinx = __kernel_sin (y[0], y[1], 1);
*cosx = __kernel_cos (y[0], y[1]);
break;
case 1:
*sinx = __kernel_cos (y[0], y[1]);
*cosx = -__kernel_sin (y[0], y[1], 1);
break;
case 2:
*sinx = -__kernel_sin (y[0], y[1], 1);
*cosx = -__kernel_cos (y[0], y[1]);
break;
default:
*sinx = -__kernel_cos (y[0], y[1]);
*cosx = __kernel_sin (y[0], y[1], 1);
break;
}
}
}
weak_alias (__sincos, sincos)
#ifdef NO_LONG_DOUBLE
strong_alias (__sincos, __sincosl)
weak_alias (__sincos, sincosl)
#endif