f-stack/dpdk/lib/librte_sched/rte_approx.h

76 lines
2.6 KiB
C

/*-
* 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
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*
* * 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
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*/
#ifndef __INCLUDE_RTE_APPROX_H__
#define __INCLUDE_RTE_APPROX_H__
#ifdef __cplusplus
extern "C" {
#endif
/**
* @file
* RTE Rational Approximation
*
* Given a rational number alpha with 0 < alpha < 1 and a precision d, the goal
* is to find positive integers p, q such that alpha - d < p/q < alpha + d, and
* q is minimal.
*
***/
#include <stdint.h>
/**
* Find best rational approximation
*
* @param alpha
* Rational number to approximate
* @param d
* Precision for the rational approximation
* @param p
* Pointer to pre-allocated space where the numerator of the rational
* approximation will be stored when operation is successful
* @param q
* Pointer to pre-allocated space where the denominator of the rational
* approximation will be stored when operation is successful
* @return
* 0 upon success, error code otherwise
*/
int rte_approx(double alpha, double d, uint32_t *p, uint32_t *q);
#ifdef __cplusplus
}
#endif
#endif /* __INCLUDE_RTE_APPROX_H__ */