1 /* SPDX-License-Identifier: BSD-3-Clause 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 static inline uint64_t 54 rte_get_gcd64(uint64_t a, uint64_t b) 55 { 56 uint64_t c; 57 58 if (a == 0) 59 return b; 60 if (b == 0) 61 return a; 62 63 if (a < b) { 64 c = a; 65 a = b; 66 b = c; 67 } 68 69 while (b != 0) { 70 c = a % b; 71 a = b; 72 b = c; 73 } 74 75 return a; 76 } 77 78 /* 79 * 32-bit version of Greatest Common Divisor (GCD). 80 */ 81 static inline uint32_t 82 rte_get_gcd(uint32_t a, uint32_t b) 83 { 84 return rte_get_gcd64(a, b); 85 } 86 87 /* 88 * Compute the Lowest Common Denominator (LCD) of two numbers. 89 * This implementation computes GCD first: 90 * LCD(a, b) = (a * b) / GCD(a, b) 91 */ 92 static inline uint32_t 93 rte_get_lcd(uint32_t a, uint32_t b) 94 { 95 return (a * b) / rte_get_gcd(a, b); 96 } 97 98 #ifdef __cplusplus 99 } 100 #endif 101 102 #endif /* __INCLUDE_RTE_SCHED_COMMON_H__ */ 103