[857] | 1 | /* Boost interval/detail/msvc_rounding_control.hpp file
|
---|
| 2 | *
|
---|
| 3 | * Copyright 2000 Maarten Keijzer
|
---|
| 4 | * Copyright 2002 Hervé Brönnimann, Guillaume Melquiond, Sylvain Pion
|
---|
| 5 | *
|
---|
| 6 | * Distributed under the Boost Software License, Version 1.0.
|
---|
| 7 | * (See accompanying file LICENSE_1_0.txt or
|
---|
| 8 | * copy at http://www.boost.org/LICENSE_1_0.txt)
|
---|
| 9 | */
|
---|
| 10 |
|
---|
| 11 | #ifndef BOOST_NUMERIC_INTERVAL_DETAIL_MSVC_ROUNDING_CONTROL_HPP
|
---|
| 12 | #define BOOST_NUMERIC_INTERVAL_DETAIL_MSVC_ROUNDING_CONTROL_HPP
|
---|
| 13 |
|
---|
| 14 | #ifndef _MSC_VER
|
---|
| 15 | # error This header is only intended for MSVC, but might work for Borland as well
|
---|
| 16 | #endif
|
---|
| 17 |
|
---|
| 18 | #include <float.h> // MSVC rounding control
|
---|
| 19 |
|
---|
| 20 | namespace boost {
|
---|
| 21 | namespace numeric {
|
---|
| 22 | namespace interval_lib {
|
---|
| 23 | namespace detail {
|
---|
| 24 |
|
---|
| 25 | extern "C" { double rint(double); }
|
---|
| 26 |
|
---|
| 27 | struct x86_rounding
|
---|
| 28 | {
|
---|
| 29 | static unsigned int hard2msvc(unsigned short m) {
|
---|
| 30 | unsigned int n = 0;
|
---|
| 31 | if (m & 0x01) n |= _EM_INVALID;
|
---|
| 32 | if (m & 0x02) n |= _EM_DENORMAL;
|
---|
| 33 | if (m & 0x04) n |= _EM_ZERODIVIDE;
|
---|
| 34 | if (m & 0x08) n |= _EM_OVERFLOW;
|
---|
| 35 | if (m & 0x10) n |= _EM_UNDERFLOW;
|
---|
| 36 | if (m & 0x20) n |= _EM_INEXACT;
|
---|
| 37 | switch (m & 0x300) {
|
---|
| 38 | case 0x000: n |= _PC_24; break;
|
---|
| 39 | case 0x200: n |= _PC_53; break;
|
---|
| 40 | case 0x300: n |= _PC_64; break;
|
---|
| 41 | }
|
---|
| 42 | switch (m & 0xC00) {
|
---|
| 43 | case 0x000: n |= _RC_NEAR; break;
|
---|
| 44 | case 0x400: n |= _RC_DOWN; break;
|
---|
| 45 | case 0x800: n |= _RC_UP; break;
|
---|
| 46 | case 0xC00: n |= _RC_CHOP; break;
|
---|
| 47 | }
|
---|
| 48 | if (m & 0x1000) n |= _IC_AFFINE; // only useful on 287
|
---|
| 49 | return n;
|
---|
| 50 | }
|
---|
| 51 |
|
---|
| 52 | static unsigned short msvc2hard(unsigned int n) {
|
---|
| 53 | unsigned short m = 0;
|
---|
| 54 | if (n & _EM_INVALID) m |= 0x01;
|
---|
| 55 | if (n & _EM_DENORMAL) m |= 0x02;
|
---|
| 56 | if (n & _EM_ZERODIVIDE) m |= 0x04;
|
---|
| 57 | if (n & _EM_OVERFLOW) m |= 0x08;
|
---|
| 58 | if (n & _EM_UNDERFLOW) m |= 0x10;
|
---|
| 59 | if (n & _EM_INEXACT) m |= 0x20;
|
---|
| 60 | switch (n & _MCW_RC) {
|
---|
| 61 | case _RC_NEAR: m |= 0x000; break;
|
---|
| 62 | case _RC_DOWN: m |= 0x400; break;
|
---|
| 63 | case _RC_UP: m |= 0x800; break;
|
---|
| 64 | case _RC_CHOP: m |= 0xC00; break;
|
---|
| 65 | }
|
---|
| 66 | switch (n & _MCW_PC) {
|
---|
| 67 | case _PC_24: m |= 0x000; break;
|
---|
| 68 | case _PC_53: m |= 0x200; break;
|
---|
| 69 | case _PC_64: m |= 0x300; break;
|
---|
| 70 | }
|
---|
| 71 | if ((n & _MCW_IC) == _IC_AFFINE) m |= 0x1000;
|
---|
| 72 | return m;
|
---|
| 73 | }
|
---|
| 74 |
|
---|
| 75 | typedef unsigned short rounding_mode;
|
---|
| 76 | static void get_rounding_mode(rounding_mode& mode)
|
---|
| 77 | { mode = msvc2hard(_control87(0, 0)); }
|
---|
| 78 | static void set_rounding_mode(const rounding_mode mode)
|
---|
| 79 | { _control87(hard2msvc(mode), _MCW_EM | _MCW_RC | _MCW_PC | _MCW_IC); }
|
---|
| 80 | static double to_int(const double& x) { return rint(x); }
|
---|
| 81 | };
|
---|
| 82 |
|
---|
| 83 | } // namespace detail
|
---|
| 84 | } // namespace interval_lib
|
---|
| 85 | } // namespace numeric
|
---|
| 86 | } // namespace boost
|
---|
| 87 |
|
---|
| 88 | #endif /* BOOST_NUMERIC_INTERVAL_DETAIL_MSVC_ROUNDING_CONTROL_HPP */
|
---|