/* Round to integer generic implementation.

   Copyright (C) 2019 Free Software Foundation, Inc.

   This file is part of the GNU C Library

   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/>.  */

#ifndef _ROUND_TO_INTEGER_H

#define _ROUND_TO_INTEGER_H

#include <fenv_private.h>

enum round_mode

{

  CEIL

};

static inline void

set_fenv_mode (enum round_mode mode)

{

  int rmode;

  switch (mode)

  {

  case CEIL:  rmode = FE_UPWARD; break;

  default:    rmode = FE_TONEAREST; break;

  }

  __fesetround_inline_nocheck (rmode);

}

static inline float

round_to_integer_float (enum round_mode mode, float x)

{

  /* Ensure sNaN input is converted to qNaN.  */

  if (__glibc_unlikely (isnan (x)))

    return x + x;

  if (fabs (x) > 0x1p+23)

    return x;

  float r = x;

  /* Save current FPU rounding mode and inexact state.  */

  fenv_t fe = fegetenv_register ();

  set_fenv_mode (mode);

  if (x > 0.0)

    {

      r += 0x1p+23;

      r -= 0x1p+23;

      r = fabs (r);

    }

  else if (x < 0.0)

    {

      r -= 0x1p+23;

      r += 0x1p+23;

      r = -fabs (r);

    }

  __builtin_mtfsf (0xff, fe);

  return r;

}

static inline double

round_to_integer_double (enum round_mode mode, double x)

{

  /* Ensure sNaN input is converted to qNaN.  */

  if (__glibc_unlikely (isnan (x)))

    return x + x;

  if (fabs (x) > 0x1p+52)

    return x;

  double r = x;

  /* Save current FPU rounding mode and inexact state.  */

  fenv_t fe = fegetenv_register ();

  set_fenv_mode (mode);

  if (x > 0.0)

    {

      r += 0x1p+52;

      r -= 0x1p+52;

      r = fabs (r);

    }

  else if (x < 0.0)

    {

      r -= 0x1p+52;

      r += 0x1p+52;

      r = -fabs (r);

    }

  __builtin_mtfsf (0xff, fe);

  return r;

}

#endif