/* k_cosf.c -- float version of k_cos.c

   Copyright (C) 2011-2018 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   = 7.4505806e-09;

static const float dot3     = 3.0000001e-01;

static const float dot78125 = 7.8125000e-01;

static const float one =  1.0000000000e+00;

static const float C1  =  4.1666667908e-02;

static const float C2  = -1.3888889225e-03;

static const float C3  =  2.4801587642e-05;

static const float C4  = -2.7557314297e-07;

static const float C5  =  2.0875723372e-09;

static const float C6  = -1.1359647598e-11;

float

__kernel_cosf (float x, float y)

{

  float a, hz, z, r, qx;

  float ix;

  ix = __builtin_fabsf (x);

  if (ix < twom27)

    {				/* |x| < 2**-27 */

      __feraiseexcept (FE_INEXACT);

      return one;

    }

  z = x * x;

  r = z * (C1 + z * (C2 + z * (C3 + z * (C4 + z * (C5 + z * C6)))));

  if (ix < dot3)		/* if |x| < 0.3 */

    return one - ((float) 0.5 * z - (z * r - x * y));

  else

    {

      if (ix > dot78125)

	{			/* x > 0.78125 */

	  qx = (float) 0.28125;

	}

      else

	{

	  qx = ix / 4.0;

	}

      hz = (float) 0.5 *z - qx;

      a = one - qx;

      return a - (hz - (z * r - x * y));

    }

}