aboutsummaryrefslogtreecommitdiffstats
path: root/lib/librte_sched/rte_sched_common.h
blob: aed144ba2f71cf9b1dd93a587c3e7584b2ab4270 (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
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
/*-
 *   BSD LICENSE
 *
 *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
 *   All rights reserved.
 *
 *   Redistribution and use in source and binary forms, with or without
 *   modification, are permitted provided that the following conditions
 *   are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *     * Neither the name of Intel Corporation nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef __INCLUDE_RTE_SCHED_COMMON_H__
#define __INCLUDE_RTE_SCHED_COMMON_H__

#ifdef __cplusplus
extern "C" {
#endif

#include <stdint.h>
#include <sys/types.h>

#define __rte_aligned_16 __attribute__((__aligned__(16)))

static inline uint32_t
rte_sched_min_val_2_u32(uint32_t x, uint32_t y)
{
	return (x < y)? x : y;
}

#if 0
static inline uint32_t
rte_min_pos_4_u16(uint16_t *x)
{
	uint32_t pos0, pos1;

	pos0 = (x[0] <= x[1])? 0 : 1;
	pos1 = (x[2] <= x[3])? 2 : 3;

	return (x[pos0] <= x[pos1])? pos0 : pos1;
}

#else

/* simplified version to remove branches with CMOV instruction */
static inline uint32_t
rte_min_pos_4_u16(uint16_t *x)
{
	uint32_t pos0 = 0;
	uint32_t pos1 = 2;

	if (x[1] <= x[0]) pos0 = 1;
	if (x[3] <= x[2]) pos1 = 3;
	if (x[pos1] <= x[pos0]) pos0 = pos1;

	return pos0;
}

#endif

/*
 * Compute the Greatest Common Divisor (GCD) of two numbers.
 * This implementation uses Euclid's algorithm:
 *    gcd(a, 0) = a
 *    gcd(a, b) = gcd(b, a mod b)
 *
 */
static inline uint32_t
rte_get_gcd(uint32_t a, uint32_t b)
{
	uint32_t c;

	if (a == 0)
		return b;
	if (b == 0)
		return a;

	if (a < b) {
		c = a;
		a = b;
		b = c;
	}

	while (b != 0) {
		c = a % b;
		a = b;
		b = c;
	}

	return a;
}

/*
 * Compute the Lowest Common Denominator (LCD) of two numbers.
 * This implementation computes GCD first:
 *    LCD(a, b) = (a * b) / GCD(a, b)
 *
 */
static inline uint32_t
rte_get_lcd(uint32_t a, uint32_t b)
{
	return (a * b) / rte_get_gcd(a, b);
}

#ifdef __cplusplus
}
#endif

#endif /* __INCLUDE_RTE_SCHED_COMMON_H__ */