/* Boost interval/detail/msvc_rounding_control.hpp file | |
* | |
* Copyright 2000 Maarten Keijzer | |
* Copyright 2002 Hervé Brönnimann, Guillaume Melquiond, Sylvain Pion | |
* | |
* Distributed under the Boost Software License, Version 1.0. | |
* (See accompanying file LICENSE_1_0.txt or | |
* copy at http://www.boost.org/LICENSE_1_0.txt) | |
*/ | |
#ifndef BOOST_NUMERIC_INTERVAL_DETAIL_MSVC_ROUNDING_CONTROL_HPP | |
#define BOOST_NUMERIC_INTERVAL_DETAIL_MSVC_ROUNDING_CONTROL_HPP | |
#ifndef _MSC_VER | |
# error This header is only intended for MSVC, but might work for Borland as well | |
#endif | |
#include <float.h> // MSVC rounding control | |
// Although the function is called _control87, it seems to work for | |
// other FPUs too, so it does not have to be changed to _controlfp. | |
namespace boost { | |
namespace numeric { | |
namespace interval_lib { | |
namespace detail { | |
#if BOOST_MSVC < 1400 || defined(WIN64) | |
extern "C" { double rint(double); } | |
#else | |
inline double rint(double x) | |
{ | |
_asm FLD [x] ; | |
_asm FRNDINT ; | |
//_asm RET ; | |
} | |
#endif | |
struct x86_rounding | |
{ | |
static unsigned int hard2msvc(unsigned short m) { | |
unsigned int n = 0; | |
if (m & 0x01) n |= _EM_INVALID; | |
if (m & 0x02) n |= _EM_DENORMAL; | |
if (m & 0x04) n |= _EM_ZERODIVIDE; | |
if (m & 0x08) n |= _EM_OVERFLOW; | |
if (m & 0x10) n |= _EM_UNDERFLOW; | |
if (m & 0x20) n |= _EM_INEXACT; | |
switch (m & 0x300) { | |
case 0x000: n |= _PC_24; break; | |
case 0x200: n |= _PC_53; break; | |
case 0x300: n |= _PC_64; break; | |
} | |
switch (m & 0xC00) { | |
case 0x000: n |= _RC_NEAR; break; | |
case 0x400: n |= _RC_DOWN; break; | |
case 0x800: n |= _RC_UP; break; | |
case 0xC00: n |= _RC_CHOP; break; | |
} | |
if (m & 0x1000) n |= _IC_AFFINE; // only useful on 287 | |
return n; | |
} | |
static unsigned short msvc2hard(unsigned int n) { | |
unsigned short m = 0; | |
if (n & _EM_INVALID) m |= 0x01; | |
if (n & _EM_DENORMAL) m |= 0x02; | |
if (n & _EM_ZERODIVIDE) m |= 0x04; | |
if (n & _EM_OVERFLOW) m |= 0x08; | |
if (n & _EM_UNDERFLOW) m |= 0x10; | |
if (n & _EM_INEXACT) m |= 0x20; | |
switch (n & _MCW_RC) { | |
case _RC_NEAR: m |= 0x000; break; | |
case _RC_DOWN: m |= 0x400; break; | |
case _RC_UP: m |= 0x800; break; | |
case _RC_CHOP: m |= 0xC00; break; | |
} | |
switch (n & _MCW_PC) { | |
case _PC_24: m |= 0x000; break; | |
case _PC_53: m |= 0x200; break; | |
case _PC_64: m |= 0x300; break; | |
} | |
if ((n & _MCW_IC) == _IC_AFFINE) m |= 0x1000; | |
return m; | |
} | |
typedef unsigned short rounding_mode; | |
static void get_rounding_mode(rounding_mode& mode) | |
{ mode = msvc2hard(_control87(0, 0)); } | |
static void set_rounding_mode(const rounding_mode mode) | |
{ _control87(hard2msvc(mode), _MCW_EM | _MCW_RC | _MCW_PC | _MCW_IC); } | |
static double to_int(const double& x) { return rint(x); } | |
}; | |
} // namespace detail | |
} // namespace interval_lib | |
} // namespace numeric | |
} // namespace boost | |
#endif /* BOOST_NUMERIC_INTERVAL_DETAIL_MSVC_ROUNDING_CONTROL_HPP */ |