| /* s_cosf.c -- float version of s_cos.c. |
| Copyright (C) 2011-2014 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 <errno.h> |
| #include <math.h> |
| #include <math_private.h> |
| |
| static const float one = 1.0; |
| static const float pio4 = 7.8539801e-1; |
| |
| float |
| __cosf (float x) |
| { |
| float y[2], z = 0.0; |
| float ix; |
| int32_t n; |
| |
| ix = __builtin_fabsf (x); |
| |
| /* |x| ~< pi/4 */ |
| if (ix <= pio4) |
| { |
| return __kernel_cosf (x, z); |
| /* cos(Inf or NaN) is NaN */ |
| } |
| else if (isnanf (ix)) |
| { |
| return x - x; |
| } |
| else if (isinff (ix)) |
| { |
| __set_errno (EDOM); |
| return x - x; |
| } |
| |
| /* argument reduction needed */ |
| else |
| { |
| n = __ieee754_rem_pio2f (x, y); |
| switch (n & 3) |
| { |
| case 0: |
| return __kernel_cosf (y[0], y[1]); |
| case 1: |
| return -__kernel_sinf (y[0], y[1], 1); |
| case 2: |
| return -__kernel_cosf (y[0], y[1]); |
| default: |
| return __kernel_sinf (y[0], y[1], 1); |
| } |
| } |
| } |
| |
| weak_alias (__cosf, cosf) |
