boost/numeric/interval/detail/x86_rounding_control.hpp
/* Boost interval/detail/x86_rounding_control.hpp file
*
* Copyright Jens Maurer 2000
* Copyright Herv� Br�nnimann, Guillaume Melquiond, Sylvain Pion 2002
* Permission to use, copy, modify, sell, and distribute this software
* is hereby granted without fee provided that the above copyright notice
* appears in all copies and that both that copyright notice and this
* permission notice appear in supporting documentation,
*
* None of the above authors nor Polytechnic University make any
* representation about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
* $Id: x86_rounding_control.hpp,v 1.6 2003/05/30 13:54:58 gmelquio Exp $
*/
#ifndef BOOST_NUMERIC_INTERVAL_DETAIL_X86_ROUNDING_CONTROL_HPP
#define BOOST_NUMERIC_INTERVAL_DETAIL_X86_ROUNDING_CONTROL_HPP
#ifdef __GNUC__
# include <boost/numeric/interval/detail/x86gcc_rounding_control.hpp>
#elif defined(__BORLANDC__)
# include <boost/numeric/interval/detail/bcc_rounding_control.hpp>
#elif defined(_MSC_VER)
# include <boost/numeric/interval/detail/msvc_rounding_control.hpp>
#elif defined(__MWERKS__) || defined(__ICC)
# define BOOST_NUMERIC_INTERVAL_USE_C99_SUBSYSTEM
# include <boost/numeric/interval/detail/c99sub_rounding_control.hpp>
#else
# error Unsupported C++ compiler.
#endif
namespace boost {
namespace numeric {
namespace interval_lib {
namespace detail {
#ifdef BOOST_NUMERIC_INTERVAL_USE_C99_SUBSYSTEM
typedef c99_rounding x86_rounding_control;
#undef BOOST_NUMERIC_INTERVAL_USE_C99_SUBSYSTEM
#else
struct fpu_rounding_modes
{
unsigned short to_nearest;
unsigned short downward;
unsigned short upward;
unsigned short toward_zero;
};
// exceptions masked, extended precision
// hardware default is 0x037f (0x1000 only has a meaning on 287)
static const fpu_rounding_modes rnd_mode = { 0x137f, 0x177f, 0x1b7f, 0x1f7f };
struct x86_rounding_control: x86_rounding
{
static void to_nearest() { set_rounding_mode(rnd_mode.to_nearest); }
static void downward() { set_rounding_mode(rnd_mode.downward); }
static void upward() { set_rounding_mode(rnd_mode.upward); }
static void toward_zero() { set_rounding_mode(rnd_mode.toward_zero); }
};
#endif // BOOST_NUMERIC_INTERVAL_USE_C99_SUBSYSTEM
} // namespace detail
template<>
struct rounding_control<float>: detail::x86_rounding_control
{
static float force_rounding(const float& r)
{ volatile float r_ = r; return r_; }
};
template<>
struct rounding_control<double>: detail::x86_rounding_control
{
/*static double force_rounding(double r)
{ asm volatile ("" : "+m"(r) : ); return r; }*/
static double force_rounding(const double& r)
{ volatile double r_ = r; return r_; }
};
template<>
struct rounding_control<long double>: detail::x86_rounding_control
{
static const long double& force_rounding(const long double& r) { return r; }
};
} // namespace interval_lib
} // namespace numeric
} // namespace boost
#endif /* BOOST_NUMERIC_INTERVAL_DETAIL_X86_ROUNDING_CONTROL_HPP */