[857] | 1 | /* Boost interval/detail/ppc_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 | * Copyright 2005 Guillaume Melquiond
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| 6 | *
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| 7 | * Distributed under the Boost Software License, Version 1.0.
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| 8 | * (See accompanying file LICENSE_1_0.txt or
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| 9 | * copy at http://www.boost.org/LICENSE_1_0.txt)
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| 10 | */
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| 11 |
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| 12 | #ifndef BOOST_NUMERIC_INTERVAL_DETAIL_PPC_ROUNDING_CONTROL_HPP
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| 13 | #define BOOST_NUMERIC_INTERVAL_DETAIL_PPC_ROUNDING_CONTROL_HPP
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| 14 |
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| 15 | #if !defined(powerpc) && !defined(__powerpc__) && !defined(__ppc__)
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| 16 | #error This header only works on PPC CPUs.
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| 17 | #endif
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| 18 |
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| 19 | #if defined(__GNUC__ ) || (__IBMCPP__ >= 700)
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| 20 |
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| 21 | namespace boost {
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| 22 | namespace numeric {
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| 23 | namespace interval_lib {
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| 24 | namespace detail {
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| 25 |
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| 26 | typedef union {
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| 27 | ::boost::long_long_type imode;
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| 28 | double dmode;
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| 29 | } rounding_mode_struct;
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| 30 |
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| 31 | static const rounding_mode_struct mode_upward = { 0xFFF8000000000002LL };
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| 32 | static const rounding_mode_struct mode_downward = { 0xFFF8000000000003LL };
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| 33 | static const rounding_mode_struct mode_to_nearest = { 0xFFF8000000000001LL };
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| 34 | static const rounding_mode_struct mode_toward_zero = { 0xFFF8000000000000LL };
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| 35 |
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| 36 | struct ppc_rounding_control
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| 37 | {
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| 38 | typedef double rounding_mode;
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| 39 |
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| 40 | static void set_rounding_mode(const rounding_mode mode)
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| 41 | { __asm__ __volatile__ ("mtfsf 255,%0" : : "f"(mode)); }
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| 42 |
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| 43 | static void get_rounding_mode(rounding_mode& mode)
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| 44 | { __asm__ __volatile__ ("mffs %0" : "=f"(mode)); }
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| 45 |
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| 46 | static void downward() { set_rounding_mode(mode_downward.dmode); }
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| 47 | static void upward() { set_rounding_mode(mode_upward.dmode); }
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| 48 | static void to_nearest() { set_rounding_mode(mode_to_nearest.dmode); }
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| 49 | static void toward_zero() { set_rounding_mode(mode_toward_zero.dmode); }
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| 50 | };
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| 51 |
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| 52 | } // namespace detail
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| 53 |
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| 54 | extern "C" {
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| 55 | float rintf(float);
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| 56 | double rint(double);
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| 57 | }
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| 58 |
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| 59 | template<>
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| 60 | struct rounding_control<float>:
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| 61 | detail::ppc_rounding_control
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| 62 | {
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| 63 | static float force_rounding(const float r)
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| 64 | {
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| 65 | float tmp;
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| 66 | __asm__ __volatile__ ("frsp %0, %1" : "=f" (tmp) : "f" (r));
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| 67 | return tmp;
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| 68 | }
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| 69 | static float to_int(const float& x) { return rintf(x); }
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| 70 | };
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| 71 |
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| 72 | template<>
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| 73 | struct rounding_control<double>:
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| 74 | detail::ppc_rounding_control
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| 75 | {
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| 76 | static const double & force_rounding(const double& r) { return r; }
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| 77 | static double to_int(const double& r) { return rint(r); }
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| 78 | };
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| 79 |
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| 80 | template<>
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| 81 | struct rounding_control<long double>:
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| 82 | detail::ppc_rounding_control
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| 83 | {
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| 84 | static const long double & force_rounding(const long double& r) { return r; }
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| 85 | static long double to_int(const long double& r) { return rint(r); }
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| 86 | };
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| 87 |
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| 88 | } // namespace interval_lib
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| 89 | } // namespace numeric
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| 90 | } // namespace boost
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| 91 |
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| 92 | #undef BOOST_NUMERIC_INTERVAL_NO_HARDWARE
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| 93 | #endif
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| 94 |
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| 95 | #endif /* BOOST_NUMERIC_INTERVAL_DETAIL_PPC_ROUNDING_CONTROL_HPP */
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