DPDK  20.08.0
rte_sched_common.h
2  * Copyright(c) 2010-2014 Intel Corporation
3  */
4
5 #ifndef __INCLUDE_RTE_SCHED_COMMON_H__
6 #define __INCLUDE_RTE_SCHED_COMMON_H__
7
8 #ifdef __cplusplus
9 extern "C" {
10 #endif
11
12 #include <stdint.h>
13 #include <sys/types.h>
14
15 #define __rte_aligned_16 __rte_aligned(16)
16
17 #if 0
18 static inline uint32_t
19 rte_min_pos_4_u16(uint16_t *x)
20 {
21  uint32_t pos0, pos1;
22
23  pos0 = (x[0] <= x[1])? 0 : 1;
24  pos1 = (x[2] <= x[3])? 2 : 3;
25
26  return (x[pos0] <= x[pos1])? pos0 : pos1;
27 }
28
29 #else
30
31 /* simplified version to remove branches with CMOV instruction */
32 static inline uint32_t
33 rte_min_pos_4_u16(uint16_t *x)
34 {
35  uint32_t pos0 = 0;
36  uint32_t pos1 = 2;
37
38  if (x[1] <= x[0]) pos0 = 1;
39  if (x[3] <= x[2]) pos1 = 3;
40  if (x[pos1] <= x[pos0]) pos0 = pos1;
41
42  return pos0;
43 }
44
45 #endif
46
47 /*
48  * Compute the Greatest Common Divisor (GCD) of two numbers.
49  * This implementation uses Euclid's algorithm:
50  * gcd(a, 0) = a
51  * gcd(a, b) = gcd(b, a mod b)
52  *
53  */
54 static inline uint32_t
55 rte_get_gcd(uint32_t a, uint32_t b)
56 {
57  uint32_t c;
58
59  if (a == 0)
60  return b;
61  if (b == 0)
62  return a;
63
64  if (a < b) {
65  c = a;
66  a = b;
67  b = c;
68  }
69
70  while (b != 0) {
71  c = a % b;
72  a = b;
73  b = c;
74  }
75
76  return a;
77 }
78
79 /*
80  * Compute the Lowest Common Denominator (LCD) of two numbers.
81  * This implementation computes GCD first:
82  * LCD(a, b) = (a * b) / GCD(a, b)
83  *
84  */
85 static inline uint32_t
86 rte_get_lcd(uint32_t a, uint32_t b)
87 {
88  return (a * b) / rte_get_gcd(a, b);
89 }
90
91 #ifdef __cplusplus
92 }
93 #endif
94
95 #endif /* __INCLUDE_RTE_SCHED_COMMON_H__ */