uclibc-ng/libm/w_atan2f.c

/* Copyright (C) 2011-2016 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@gmail.com>, 2011.

   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/>.  */

/*
 * wrapper atan2f(y,x)
 */


#include <math.h>
#include "math_private.h"
#if defined(__UCLIBC_HAS_FENV__)
#include <errno.h>
#endif

float
atan2f (float y, float x)
{
#if defined(__UCLIBC_HAS_FENV__)
  float z;

  if (__builtin_expect (x == 0.0f && y == 0.0f, 0) && _LIB_VERSION == _SVID_)
    return __kernel_standard_f (y, x, 103); /* atan2(+-0,+-0) */

  z = (float) __ieee754_atan2 ((double) y, (double) x);
  if (__builtin_expect (z == 0.0f && y != 0.0f && isfinite (x), 0))
    __set_errno (ERANGE);
  return z;
#else
  return (float) __ieee754_atan2 ((double) y, (double) x);
#endif
}