114 lines
3.6 KiB
Plaintext
114 lines
3.6 KiB
Plaintext
/* Boost interval/detail/alpha_rounding_control.hpp file
|
|
*
|
|
* Copyright 2005 Felix Höfling, 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_ALPHA_ROUNDING_CONTROL_HPP
|
|
#define BOOST_NUMERIC_INTERVAL_DETAIL_ALPHA_ROUNDING_CONTROL_HPP
|
|
|
|
#if !defined(alpha) && !defined(__alpha__)
|
|
#error This header only works on Alpha CPUs.
|
|
#endif
|
|
|
|
#if defined(__GNUC__) || defined(__digital__) || defined(__DECCXX)
|
|
|
|
#include <float.h> // write_rnd() and read_rnd()
|
|
|
|
namespace boost {
|
|
namespace numeric {
|
|
namespace interval_lib {
|
|
|
|
namespace detail {
|
|
#if defined(__GNUC__ )
|
|
typedef union {
|
|
::boost::long_long_type imode;
|
|
double dmode;
|
|
} rounding_mode_struct;
|
|
|
|
// set bits 59-58 (DYN),
|
|
// clear all exception bits and disable overflow (51) and inexact exceptions (62)
|
|
static const rounding_mode_struct mode_upward = { 0x4C08000000000000LL };
|
|
static const rounding_mode_struct mode_downward = { 0x4408000000000000LL };
|
|
static const rounding_mode_struct mode_to_nearest = { 0x4808000000000000LL };
|
|
static const rounding_mode_struct mode_toward_zero = { 0x4008000000000000LL };
|
|
|
|
struct alpha_rounding_control
|
|
{
|
|
typedef double rounding_mode;
|
|
|
|
static void set_rounding_mode(const rounding_mode mode)
|
|
{ __asm__ __volatile__ ("mt_fpcr %0" : : "f"(mode)); }
|
|
|
|
static void get_rounding_mode(rounding_mode& mode)
|
|
{ __asm__ __volatile__ ("mf_fpcr %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); }
|
|
};
|
|
#elif defined(__digital__) || defined(__DECCXX)
|
|
|
|
#if defined(__DECCXX) && !(defined(__FLT_ROUNDS) && __FLT_ROUNDS == -1)
|
|
#error Dynamic rounding mode not enabled. See cxx man page for details.
|
|
#endif
|
|
|
|
struct alpha_rounding_control
|
|
{
|
|
typedef unsigned int rounding_mode;
|
|
|
|
static void set_rounding_mode(const rounding_mode& mode) { write_rnd(mode); }
|
|
static void get_rounding_mode(rounding_mode& mode) { mode = read_rnd(); }
|
|
|
|
static void downward() { set_rounding_mode(FP_RND_RM); }
|
|
static void upward() { set_rounding_mode(FP_RND_RP); }
|
|
static void to_nearest() { set_rounding_mode(FP_RND_RN); }
|
|
static void toward_zero() { set_rounding_mode(FP_RND_RZ); }
|
|
};
|
|
#endif
|
|
} // namespace detail
|
|
|
|
extern "C" {
|
|
float rintf(float);
|
|
double rint(double);
|
|
long double rintl(long double);
|
|
}
|
|
|
|
template<>
|
|
struct rounding_control<float>:
|
|
detail::alpha_rounding_control
|
|
{
|
|
static float force_rounding(const float r)
|
|
{ volatile float _r = r; return _r; }
|
|
static float to_int(const float& x) { return rintf(x); }
|
|
};
|
|
|
|
template<>
|
|
struct rounding_control<double>:
|
|
detail::alpha_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::alpha_rounding_control
|
|
{
|
|
static const long double & force_rounding(const long double& r) { return r; }
|
|
static long double to_int(const long double& r) { return rintl(r); }
|
|
};
|
|
|
|
} // namespace interval_lib
|
|
} // namespace numeric
|
|
} // namespace boost
|
|
|
|
#undef BOOST_NUMERIC_INTERVAL_NO_HARDWARE
|
|
#endif
|
|
|
|
#endif /* BOOST_NUMERIC_INTERVAL_DETAIL_ALPHA_ROUNDING_CONTROL_HPP */
|