rapicornmath.hh

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/* Rapicorn
 * Copyright (C) 2006 Tim Janik
 *
 * This 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.
 *
 * This 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.
 *
 * A copy of the GNU Lesser General Public License should ship along
 * with this library; if not, see http://www.gnu.org/copyleft/.
 */
#ifndef __RAPICORN_MATH_HH__
#define __RAPICORN_MATH_HH__

#include <rcore/utilities.hh>
#include <math.h>

namespace Rapicorn {

/* --- double to integer --- */
inline int      dtoi32 (double d) RAPICORN_CONST;
inline int64    dtoi64 (double d) RAPICORN_CONST;
inline int64    iround (double d) RAPICORN_CONST;
inline int64    ifloor (double d) RAPICORN_CONST;
inline int64    iceil  (double d) RAPICORN_CONST;

/* --- implementation bits --- */
inline int RAPICORN_CONST
_dtoi32_generic (double d)
{
  /* this relies on the C++ behaviour of round-to-0 */
  return (int) (d < -0.0 ? d - 0.5 : d + 0.5);
}
inline int RAPICORN_CONST
dtoi32 (double d)
{
  /* this relies on the hardware default round-to-nearest */
#if defined __i386__ && defined __GNUC__
  int r;
  __asm__ volatile ("fistl %0"
                    : "=m" (r)
                    : "t" (d));
  return r;
#endif
  return _dtoi32_generic (d);
}
inline int64 RAPICORN_CONST
_dtoi64_generic (double d)
{
  /* this relies on the C++ behaviour of round-to-0 */
  return (int64) (d < -0.0 ? d - 0.5 : d + 0.5);
}
inline int64 RAPICORN_CONST
dtoi64 (double d)
{
  /* this relies on the hardware default round-to-nearest */
#if defined __i386__ && defined __GNUC__
  int64 r;
  __asm__ volatile ("fistpll %0"
                    : "=m" (r)
                    : "t" (d)
                    : "st");
  return r;
#endif
  return _dtoi64_generic (d);
}
inline int64 RAPICORN_CONST iround (double d) { return dtoi64 (round (d)); }
inline int64 RAPICORN_CONST ifloor (double d) { return dtoi64 (floor (d)); }
inline int64 RAPICORN_CONST iceil  (double d) { return dtoi64 (ceil (d)); }

} // Rapicorn

#endif /* __RAPICORN_MATH_HH__ */
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