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