1 | /* Boost interval/detail/x86_rounding_control.hpp file |
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2 | * |
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3 | * Copyright 2000 Jens Maurer |
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4 | * Copyright 2002 Hervé Brönnimann, Guillaume Melquiond, Sylvain Pion |
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5 | * |
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6 | * Distributed under the Boost Software License, Version 1.0. |
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7 | * (See accompanying file LICENSE_1_0.txt or |
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8 | * copy at http://www.boost.org/LICENSE_1_0.txt) |
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9 | */ |
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10 | |
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11 | #ifndef BOOST_NUMERIC_INTERVAL_DETAIL_X86_ROUNDING_CONTROL_HPP |
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12 | #define BOOST_NUMERIC_INTERVAL_DETAIL_X86_ROUNDING_CONTROL_HPP |
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13 | |
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14 | #ifdef __GNUC__ |
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15 | # include <boost/numeric/interval/detail/x86gcc_rounding_control.hpp> |
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16 | #elif defined(__BORLANDC__) |
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17 | # include <boost/numeric/interval/detail/bcc_rounding_control.hpp> |
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18 | #elif defined(_MSC_VER) |
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19 | # include <boost/numeric/interval/detail/msvc_rounding_control.hpp> |
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20 | #elif defined(__MWERKS__) || defined(__ICC) |
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21 | # define BOOST_NUMERIC_INTERVAL_USE_C99_SUBSYSTEM |
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22 | # include <boost/numeric/interval/detail/c99sub_rounding_control.hpp> |
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23 | #else |
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24 | # error Unsupported C++ compiler. |
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25 | #endif |
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26 | |
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27 | namespace boost { |
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28 | namespace numeric { |
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29 | namespace interval_lib { |
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30 | |
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31 | namespace detail { |
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32 | |
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33 | #ifdef BOOST_NUMERIC_INTERVAL_USE_C99_SUBSYSTEM |
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34 | typedef c99_rounding x86_rounding_control; |
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35 | #undef BOOST_NUMERIC_INTERVAL_USE_C99_SUBSYSTEM |
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36 | #else |
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37 | struct fpu_rounding_modes |
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38 | { |
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39 | unsigned short to_nearest; |
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40 | unsigned short downward; |
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41 | unsigned short upward; |
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42 | unsigned short toward_zero; |
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43 | }; |
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44 | |
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45 | // exceptions masked, extended precision |
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46 | // hardware default is 0x037f (0x1000 only has a meaning on 287) |
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47 | static const fpu_rounding_modes rnd_mode = { 0x137f, 0x177f, 0x1b7f, 0x1f7f }; |
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48 | |
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49 | struct x86_rounding_control: x86_rounding |
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50 | { |
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51 | static void to_nearest() { set_rounding_mode(rnd_mode.to_nearest); } |
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52 | static void downward() { set_rounding_mode(rnd_mode.downward); } |
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53 | static void upward() { set_rounding_mode(rnd_mode.upward); } |
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54 | static void toward_zero() { set_rounding_mode(rnd_mode.toward_zero); } |
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55 | }; |
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56 | #endif // BOOST_NUMERIC_INTERVAL_USE_C99_SUBSYSTEM |
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57 | |
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58 | } // namespace detail |
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59 | |
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60 | template<> |
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61 | struct rounding_control<float>: detail::x86_rounding_control |
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62 | { |
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63 | static float force_rounding(const float& r) |
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64 | { volatile float r_ = r; return r_; } |
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65 | }; |
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66 | |
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67 | template<> |
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68 | struct rounding_control<double>: detail::x86_rounding_control |
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69 | { |
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70 | /*static double force_rounding(double r) |
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71 | { asm volatile ("" : "+m"(r) : ); return r; }*/ |
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72 | static double force_rounding(const double& r) |
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73 | { volatile double r_ = r; return r_; } |
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74 | }; |
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75 | |
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76 | namespace detail { |
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77 | |
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78 | template<bool> |
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79 | struct x86_rounding_control_long_double; |
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80 | |
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81 | template<> |
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82 | struct x86_rounding_control_long_double<false>: x86_rounding_control |
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83 | { |
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84 | static long double force_rounding(long double const &r) |
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85 | { volatile long double r_ = r; return r_; } |
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86 | }; |
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87 | |
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88 | template<> |
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89 | struct x86_rounding_control_long_double<true>: x86_rounding_control |
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90 | { |
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91 | static long double const &force_rounding(long double const &r) |
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92 | { return r; } |
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93 | }; |
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94 | |
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95 | } // namespace detail |
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96 | |
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97 | template<> |
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98 | struct rounding_control<long double>: |
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99 | detail::x86_rounding_control_long_double< (sizeof(long double) >= 10) > |
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100 | {}; |
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101 | |
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102 | } // namespace interval_lib |
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103 | } // namespace numeric |
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104 | } // namespace boost |
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105 | |
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106 | #undef BOOST_NUMERIC_INTERVAL_NO_HARDWARE |
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107 | |
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108 | #endif /* BOOST_NUMERIC_INTERVAL_DETAIL_X86_ROUNDING_CONTROL_HPP */ |
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