blob: 25b6ff617f17bd20c6b3a69d544ba1a8f7e12ec3 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
|
/* 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 */
|
