LXR dpdk/lib/sched/rte_sched

   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
   9extern "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
  18static inline uint32_t
  19rte_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 */
  32static inline uint32_t
  33rte_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 */
  54static inline uint64_t
  55rte_get_gcd64(uint64_t a, uint64_t b)
  56{
  57        uint64_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 * 32-bit version of Greatest Common Divisor (GCD).
  81 */
  82static inline uint32_t
  83rte_get_gcd(uint32_t a, uint32_t b)
  84{
  85        return rte_get_gcd64(a, b);
  86}
  87
  88/*
  89 * Compute the Lowest Common Denominator (LCD) of two numbers.
  90 * This implementation computes GCD first:
  91 *    LCD(a, b) = (a * b) / GCD(a, b)
  92 *
  93 */
  94static inline uint32_t
  95rte_get_lcd(uint32_t a, uint32_t b)
  96{
  97        return (a * b) / rte_get_gcd(a, b);
  98}
  99
 100#ifdef __cplusplus
 101}
 102#endif
 103
 104#endif /* __INCLUDE_RTE_SCHED_COMMON_H__ */
 105