ceph/src/boost/libs/numeric/interval/include/boost/numeric/interval/detail/x86_rounding_control.hpp

   1 /* Boost interval/detail/x86_rounding_control.hpp file
   2  *
   3  * Copyright 2000 Jens Maurer
   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_X86_ROUNDING_CONTROL_HPP
  12 #define BOOST_NUMERIC_INTERVAL_DETAIL_X86_ROUNDING_CONTROL_HPP
  13
  14 #ifdef __GNUC__
  15 #  include <boost/numeric/interval/detail/x86gcc_rounding_control.hpp>
  16 #elif defined(__BORLANDC__)
  17 #  include <boost/numeric/interval/detail/bcc_rounding_control.hpp>
  18 #elif defined(_MSC_VER)
  19 #  include <boost/numeric/interval/detail/msvc_rounding_control.hpp>
  20 #elif defined(__MWERKS__) || defined(__ICC) || defined (__SUNPRO_CC)
  21 #  define BOOST_NUMERIC_INTERVAL_USE_C99_SUBSYSTEM
  22 #  include <boost/numeric/interval/detail/c99sub_rounding_control.hpp>
  23 #else
  24 #  error Unsupported C++ compiler.
  25 #endif
  26
  27 namespace boost {
  28 namespace numeric {
  29 namespace interval_lib {
  30
  31 namespace detail {
  32
  33 #ifdef BOOST_NUMERIC_INTERVAL_USE_C99_SUBSYSTEM
  34 typedef c99_rounding_control x86_rounding_control;
  35 #undef BOOST_NUMERIC_INTERVAL_USE_C99_SUBSYSTEM
  36 #else
  37 struct fpu_rounding_modes
  38 {
  39   unsigned short to_nearest;
  40   unsigned short downward;
  41   unsigned short upward;
  42   unsigned short toward_zero;
  43 };
  44
  45 // exceptions masked, extended precision
  46 // hardware default is 0x037f (0x1000 only has a meaning on 287)
  47 static const fpu_rounding_modes rnd_mode = { 0x137f, 0x177f, 0x1b7f, 0x1f7f };
  48
  49 struct x86_rounding_control: x86_rounding
  50 {
  51   static void to_nearest()  { set_rounding_mode(rnd_mode.to_nearest);  }
  52   static void downward()    { set_rounding_mode(rnd_mode.downward);    }
  53   static void upward()      { set_rounding_mode(rnd_mode.upward);      }
  54   static void toward_zero() { set_rounding_mode(rnd_mode.toward_zero); }
  55 };
  56 #endif // BOOST_NUMERIC_INTERVAL_USE_C99_SUBSYSTEM
  57
  58 } // namespace detail
  59
  60 template<>
  61 struct rounding_control<float>: detail::x86_rounding_control
  62 {
  63   static float force_rounding(const float& r)
  64   { volatile float r_ = r; return r_; }
  65 };
  66
  67 template<>
  68 struct rounding_control<double>: detail::x86_rounding_control
  69 {
  70   /*static double force_rounding(double r)
  71   { asm volatile ("" : "+m"(r) : ); return r; }*/
  72   static double force_rounding(const double& r)
  73   { volatile double r_ = r; return r_; }
  74 };
  75
  76 namespace detail {
  77
  78 template<bool>
  79 struct x86_rounding_control_long_double;
  80
  81 template<>
  82 struct x86_rounding_control_long_double<false>: x86_rounding_control
  83 {
  84   static long double force_rounding(long double const &r)
  85   { volatile long double r_ = r; return r_; }
  86 };
  87
  88 template<>
  89 struct x86_rounding_control_long_double<true>: x86_rounding_control
  90 {
  91   static long double const &force_rounding(long double const &r)
  92   { return r; }
  93 };
  94
  95 } // namespace detail
  96
  97 template<>
  98 struct rounding_control<long double>:
  99   detail::x86_rounding_control_long_double< (sizeof(long double) >= 10) >
 100 {};
 101
 102 } // namespace interval_lib
 103 } // namespace numeric
 104 } // namespace boost
 105
 106 #undef BOOST_NUMERIC_INTERVAL_NO_HARDWARE
 107
 108 #endif /* BOOST_NUMERIC_INTERVAL_DETAIL_X86_ROUNDING_CONTROL_HPP */