eb5636e879
This patch adds new function that compute the greatest common divisor of 64 bits, also changes the original 32 bits function to call this new 64-bit version. Cc: stable@dpdk.org Signed-off-by: Xueming Li <xuemingl@nvidia.com> Acked-by: Kevin Traynor <ktraynor@redhat.com>
105 lines
1.6 KiB
C
105 lines
1.6 KiB
C
/* SPDX-License-Identifier: BSD-3-Clause
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* Copyright(c) 2010-2014 Intel Corporation
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*/
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#ifndef __INCLUDE_RTE_SCHED_COMMON_H__
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#define __INCLUDE_RTE_SCHED_COMMON_H__
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#ifdef __cplusplus
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extern "C" {
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#endif
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#include <stdint.h>
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#include <sys/types.h>
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#define __rte_aligned_16 __rte_aligned(16)
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#if 0
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static inline uint32_t
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rte_min_pos_4_u16(uint16_t *x)
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{
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uint32_t pos0, pos1;
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pos0 = (x[0] <= x[1])? 0 : 1;
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pos1 = (x[2] <= x[3])? 2 : 3;
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return (x[pos0] <= x[pos1])? pos0 : pos1;
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}
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#else
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/* simplified version to remove branches with CMOV instruction */
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static inline uint32_t
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rte_min_pos_4_u16(uint16_t *x)
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{
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uint32_t pos0 = 0;
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uint32_t pos1 = 2;
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if (x[1] <= x[0]) pos0 = 1;
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if (x[3] <= x[2]) pos1 = 3;
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if (x[pos1] <= x[pos0]) pos0 = pos1;
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return pos0;
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}
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#endif
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/*
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* Compute the Greatest Common Divisor (GCD) of two numbers.
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* This implementation uses Euclid's algorithm:
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* gcd(a, 0) = a
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* gcd(a, b) = gcd(b, a mod b)
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*
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*/
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static inline uint64_t
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rte_get_gcd64(uint64_t a, uint64_t b)
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{
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uint64_t c;
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if (a == 0)
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return b;
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if (b == 0)
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return a;
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if (a < b) {
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c = a;
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a = b;
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b = c;
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}
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while (b != 0) {
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c = a % b;
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a = b;
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b = c;
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}
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return a;
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}
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/*
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* 32-bit version of Greatest Common Divisor (GCD).
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*/
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static inline uint32_t
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rte_get_gcd(uint32_t a, uint32_t b)
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{
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return rte_get_gcd64(a, b);
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}
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/*
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* Compute the Lowest Common Denominator (LCD) of two numbers.
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* This implementation computes GCD first:
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* LCD(a, b) = (a * b) / GCD(a, b)
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*
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*/
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static inline uint32_t
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rte_get_lcd(uint32_t a, uint32_t b)
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{
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return (a * b) / rte_get_gcd(a, b);
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}
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#ifdef __cplusplus
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}
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#endif
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#endif /* __INCLUDE_RTE_SCHED_COMMON_H__ */
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