glibc/sysdeps/powerpc/fpu/k_sinf.c

54 lines
1.7 KiB
C

/* k_sinf.c -- float version of k_sin.c
Copyright (C) 2011-2013 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Adhemerval Zanella <azanella@br.ibm.com>, 2011
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, see <http://www.gnu.org/licenses/>. */
#include <math.h>
#include <fenv.h>
#include <math_private.h>
static const float twom27 = 7.4505806000e-09;
static const float half = 5.0000000000e-01;
static const float S1 = -1.6666667163e-01;
static const float S2 = 8.3333337680e-03;
static const float S3 = -1.9841270114e-04;
static const float S4 = 2.7557314297e-06;
static const float S5 = -2.5050759689e-08;
static const float S6 = 1.5896910177e-10;
float
__kernel_sinf (float x, float y, int iy)
{
float z, r, v;
float ix;
ix = __builtin_fabsf (x);
if (ix < twom27)
{ /* |x| < 2**-27 */
__feraiseexcept (FE_INEXACT);
return x;
}
z = x * x;
v = z * x;
r = S2 + z * (S3 + z * (S4 + z * (S5 + z * S6)));
if (iy == 0)
return x + v * (S1 + z * r);
else
return x - ((z * (half * y - v * r) - y) - v * S1);
}