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