| /* 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 { |
| |
| extern "C" { double rint(double); } |
| |
| 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 */ |