GCChelper.h

/*

  RealLib, a library for efficient exact real computation
  Copyright (C) 2006 Branimir Lambov

  This library is licensed under the Apache License, Version 2.0 (the "License");
  you may not use this library except in compliance with the License.
  You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
 */

#ifndef FILE_GCCHELPER_H
#define FILE_GCCHELPER_H

#include <math.h>
#include <stdio.h>
#include <stdlib.h>

namespace RealLib {

/* Return values for fpclass. */
#define  _FPCLASS_SNAN  0x0001  /* Signaling "Not a Number" */
#define  _FPCLASS_QNAN  0x0002  /* Quiet "Not a Number" */
#define  _FPCLASS_NINF  0x0004  /* Negative Infinity */
#define  _FPCLASS_NN  0x0008  /* Negative Normal */
#define  _FPCLASS_ND  0x0010  /* Negative Denormal */
#define  _FPCLASS_NZ  0x0020  /* Negative Zero */
#define  _FPCLASS_PZ  0x0040  /* Positive Zero */
#define  _FPCLASS_PD  0x0080  /* Positive Denormal */
#define  _FPCLASS_PN  0x0100  /* Positive Normal */
#define  _FPCLASS_PINF  0x0200  /* Positive Infinity */

static inline bool __isnan(const double x)
{
    using namespace std;
    return isnan(x);
}

static inline bool __isinf(const double x)
{
    using namespace std;
    return isinf(x);
}

static inline bool _finite(const double x)
{
    return finite(x);
}

static inline int _fpclass(const double x)
{
    if (__isnan(x)) return _FPCLASS_QNAN;
    else if (__isinf(x)) return x > 0 ? _FPCLASS_PINF : _FPCLASS_NINF;
    else if (x == 0.0) return _FPCLASS_PZ;
    else return x > 0 ? _FPCLASS_PN : _FPCLASS_NN;
}

} // namespace

#endif