Chris@16: /* Boost interval/detail/ppc_rounding_control.hpp file
Chris@16:  *
Chris@16:  * Copyright 2000 Jens Maurer
Chris@16:  * Copyright 2002 Hervé Brönnimann, Guillaume Melquiond, Sylvain Pion
Chris@16:  * Copyright 2005 Guillaume Melquiond
Chris@16:  *
Chris@16:  * Distributed under the Boost Software License, Version 1.0.
Chris@16:  * (See accompanying file LICENSE_1_0.txt or
Chris@16:  * copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16:  */
Chris@16: 
Chris@16: #ifndef BOOST_NUMERIC_INTERVAL_DETAIL_PPC_ROUNDING_CONTROL_HPP
Chris@16: #define BOOST_NUMERIC_INTERVAL_DETAIL_PPC_ROUNDING_CONTROL_HPP
Chris@16: 
Chris@16: #if !defined(powerpc) && !defined(__powerpc__) && !defined(__ppc__)
Chris@16: #error This header only works on PPC CPUs.
Chris@16: #endif
Chris@16: 
Chris@16: #if defined(__GNUC__ ) || (__IBMCPP__ >= 700)
Chris@16: 
Chris@16: namespace boost {
Chris@16: namespace numeric {
Chris@16: namespace interval_lib {
Chris@16: namespace detail {
Chris@16: 
Chris@16: typedef union {
Chris@16:    ::boost::long_long_type imode;
Chris@16:   double dmode;
Chris@16: } rounding_mode_struct;
Chris@16: 
Chris@16: static const rounding_mode_struct mode_upward      = { 0xFFF8000000000002LL };
Chris@16: static const rounding_mode_struct mode_downward    = { 0xFFF8000000000003LL };
Chris@16: static const rounding_mode_struct mode_to_nearest  = { 0xFFF8000000000000LL };
Chris@16: static const rounding_mode_struct mode_toward_zero = { 0xFFF8000000000001LL };
Chris@16: 
Chris@16: struct ppc_rounding_control
Chris@16: {
Chris@16:   typedef double rounding_mode;
Chris@16: 
Chris@16:   static void set_rounding_mode(const rounding_mode mode)
Chris@16:   { __asm__ __volatile__ ("mtfsf 255,%0" : : "f"(mode)); }
Chris@16: 
Chris@16:   static void get_rounding_mode(rounding_mode& mode)
Chris@16:   { __asm__ __volatile__ ("mffs %0" : "=f"(mode)); }
Chris@16: 
Chris@16:   static void downward()    { set_rounding_mode(mode_downward.dmode);    }
Chris@16:   static void upward()      { set_rounding_mode(mode_upward.dmode);      }
Chris@16:   static void to_nearest()  { set_rounding_mode(mode_to_nearest.dmode);  }
Chris@16:   static void toward_zero() { set_rounding_mode(mode_toward_zero.dmode); }
Chris@16: };
Chris@16: 
Chris@16: } // namespace detail
Chris@16: 
Chris@16: // Do not declare the following C99 symbols if <math.h> provides them.
Chris@16: // Otherwise, conflicts may occur, due to differences between prototypes.
Chris@16: #if !defined(_ISOC99_SOURCE) && !defined(__USE_ISOC99)
Chris@16: extern "C" {
Chris@16:   float rintf(float);
Chris@16:   double rint(double);
Chris@16: }
Chris@16: #endif
Chris@16: 
Chris@16: template<>
Chris@16: struct rounding_control<float>:
Chris@16:   detail::ppc_rounding_control
Chris@16: {
Chris@16:   static float force_rounding(const float r)
Chris@16:   {
Chris@16:     float tmp;
Chris@16:     __asm__ __volatile__ ("frsp %0, %1" : "=f" (tmp) : "f" (r));
Chris@16:     return tmp;
Chris@16:   }
Chris@16:   static float to_int(const float& x) { return rintf(x); }
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct rounding_control<double>:
Chris@16:   detail::ppc_rounding_control
Chris@16: {
Chris@16:   static const double & force_rounding(const double& r) { return r; }
Chris@16:   static double to_int(const double& r) { return rint(r); }
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct rounding_control<long double>:
Chris@16:   detail::ppc_rounding_control
Chris@16: {
Chris@16:   static const long double & force_rounding(const long double& r) { return r; }
Chris@16:   static long double to_int(const long double& r) { return rint(r); }
Chris@16: };
Chris@16: 
Chris@16: } // namespace interval_lib
Chris@16: } // namespace numeric
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #undef BOOST_NUMERIC_INTERVAL_NO_HARDWARE
Chris@16: #endif
Chris@16: 
Chris@16: #endif /* BOOST_NUMERIC_INTERVAL_DETAIL_PPC_ROUNDING_CONTROL_HPP */