1 /* Copyright (C) 2011-2016 Free Software Foundation, Inc.
2    This file is part of the GNU C Library.
3    Contributed by Ulrich Drepper <drepper@gmail.com>, 2011.
4 
5    The GNU C Library is free software; you can redistribute it and/or
6    modify it under the terms of the GNU Lesser General Public
7    License as published by the Free Software Foundation; either
8    version 2.1 of the License, or (at your option) any later version.
9 
10    The GNU C Library is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13    Lesser General Public License for more details.
14 
15    You should have received a copy of the GNU Lesser General Public
16    License along with the GNU C Library; if not, see
17    <http://www.gnu.org/licenses/>.  */
18 
19 /*
20  * wrapper atan2(y,x)
21  */
22 
23 #include <math.h>
24 #include "math_private.h"
25 #if defined(__UCLIBC_HAS_FENV__)
26 #include <errno.h>
27 #endif
28 
29 double
atan2(double y,double x)30 atan2 (double y, double x)
31 {
32 #if defined(__UCLIBC_HAS_FENV__)
33   double z;
34 
35   if (__builtin_expect (x == 0.0 && y == 0.0, 0) && _LIB_VERSION == _SVID_)
36     return __kernel_standard (y, x, 3); /* atan2(+-0,+-0) */
37 
38   z = __ieee754_atan2 (y, x);
39   if (__builtin_expect (z == 0.0 && y != 0.0 && isfinite (x),0))
40     __set_errno (ERANGE);
41   return z;
42 #else
43   return __ieee754_atan2 (y, x);
44 #endif
45 }
46 libm_hidden_def(atan2)
47