glibc/sysdeps/ieee754/dbl-64/s_sincos.c

114 lines
2.6 KiB
C

/* Compute sine and cosine of argument.
Copyright (C) 1997-2017 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 Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <math.h>
#include <math_private.h>
#define __sin __sin_local
#define __cos __cos_local
#define IN_SINCOS 1
#include "s_sin.c"
/* Consolidated version of reduce_and_compute in s_sin.c that does range
reduction only once and computes sin and cos together. */
static inline void
__always_inline
reduce_and_compute_sincos (double x, double *sinx, double *cosx)
{
double a, da;
unsigned int n = __branred (x, &a, &da);
n = n & 3;
if (n == 1 || n == 2)
{
a = -a;
da = -da;
}
if (n & 1)
{
double *temp = cosx;
cosx = sinx;
sinx = temp;
}
if (a * a < 0.01588)
*sinx = bsloww (a, da, x, n);
else
*sinx = bsloww1 (a, da, x, n);
*cosx = bsloww2 (a, da, x, n);
}
void
__sincos (double x, double *sinx, double *cosx)
{
mynumber u;
int k;
SET_RESTORE_ROUND_53BIT (FE_TONEAREST);
u.x = x;
k = 0x7fffffff & u.i[HIGH_HALF];
if (k < 0x400368fd)
{
*sinx = __sin_local (x);
*cosx = __cos_local (x);
return;
}
if (k < 0x419921FB)
{
double a, da;
int4 n = reduce_sincos_1 (x, &a, &da);
*sinx = do_sincos_1 (a, da, x, n, false);
*cosx = do_sincos_1 (a, da, x, n, true);
return;
}
if (k < 0x42F00000)
{
double a, da;
int4 n = reduce_sincos_2 (x, &a, &da);
*sinx = do_sincos_2 (a, da, x, n, false);
*cosx = do_sincos_2 (a, da, x, n, true);
return;
}
if (k < 0x7ff00000)
{
reduce_and_compute_sincos (x, sinx, cosx);
return;
}
if (isinf (x))
__set_errno (EDOM);
*sinx = *cosx = x / x;
}
weak_alias (__sincos, sincos)
#ifdef NO_LONG_DOUBLE
strong_alias (__sincos, __sincosl)
weak_alias (__sincos, sincosl)
#endif