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
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
|
/*
* Copyright © 2015 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#ifndef _ROUNDING_H
#define _ROUNDING_H
#include "c99_math.h"
#include <limits.h>
#include <stdint.h>
#if defined(__SSE__) || defined(_MSC_VER)
/* MSVC always has SSE nowadays */
#include <xmmintrin.h>
#include <emmintrin.h>
#endif
#ifdef __SSE4_1__
#include <smmintrin.h>
#endif
/* The C standard library has functions round()/rint()/nearbyint() that round
* their arguments according to the rounding mode set in the floating-point
* control register. While there are trunc()/ceil()/floor() functions that do
* a specific operation without modifying the rounding mode, there is no
* roundeven() in any version of C.
*
* Technical Specification 18661 (ISO/IEC TS 18661-1:2014) adds roundeven(),
* but it's unfortunately not implemented by glibc.
*
* This implementation differs in that it does not raise the inexact exception.
*
* We use rint() to implement these functions, with the assumption that the
* floating-point rounding mode has not been changed from the default Round
* to Nearest.
*/
/**
* \brief Rounds \c x to the nearest integer, with ties to the even integer.
*/
static inline float
_mesa_roundevenf(float x)
{
#ifdef __SSE4_1__
float ret;
__m128 m = _mm_load_ss(&x);
m = _mm_round_ss(m, m, _MM_FROUND_CUR_DIRECTION | _MM_FROUND_NO_EXC);
_mm_store_ss(&ret, m);
return ret;
#else
return rintf(x);
#endif
}
/**
* \brief Rounds \c x to the nearest integer, with ties to the even integer.
*/
static inline double
_mesa_roundeven(double x)
{
#ifdef __SSE4_1__
double ret;
__m128d m = _mm_load_sd(&x);
m = _mm_round_sd(m, m, _MM_FROUND_CUR_DIRECTION | _MM_FROUND_NO_EXC);
_mm_store_sd(&ret, m);
return ret;
#else
return rint(x);
#endif
}
/**
* \brief Rounds \c x to the nearest integer, with ties to the even integer,
* and returns the value as a long int.
*/
static inline long
_mesa_lroundevenf(float x)
{
#if defined(__SSE__) || defined(_MSC_VER)
#if LONG_MAX == INT64_MAX
return _mm_cvtss_si64(_mm_load_ss(&x));
#elif LONG_MAX == INT32_MAX
return _mm_cvtss_si32(_mm_load_ss(&x));
#else
#error "Unsupported long size"
#endif
#else
return lrintf(x);
#endif
}
/**
* \brief Rounds \c x to the nearest integer, with ties to the even integer,
* and returns the value as a long int.
*/
static inline long
_mesa_lroundeven(double x)
{
#if defined(__SSE__) || defined(_MSC_VER)
#if LONG_MAX == INT64_MAX
return _mm_cvtsd_si64(_mm_load_sd(&x));
#elif LONG_MAX == INT32_MAX
return _mm_cvtsd_si32(_mm_load_sd(&x));
#else
#error "Unsupported long size"
#endif
#else
return lrint(x);
#endif
}
#endif
|
