libm/w_atan2f.c

   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 atan2f(y,x)
  21  */
  22
  23
  24 #include <math.h>
  25 #include "math_private.h"
  26 #if defined(__UCLIBC_HAS_FENV__)
  27 #include <errno.h>
  28 #endif
  29
  30 float
  31 atan2f (float y, float x)
  32 {
  33 #if defined(__UCLIBC_HAS_FENV__)
  34   float z;
  35
  36   if (__builtin_expect (x == 0.0f && y == 0.0f, 0) && _LIB_VERSION == _SVID_)
  37     return __kernel_standard_f (y, x, 103); /* atan2(+-0,+-0) */
  38
  39   z = (float) __ieee754_atan2 ((double) y, (double) x);
  40   if (__builtin_expect (z == 0.0f && y != 0.0f && isfinite (x), 0))
  41     __set_errno (ERANGE);
  42   return z;
  43 #else
  44   return (float) __ieee754_atan2 ((double) y, (double) x);
  45 #endif
  46 }