ut::fast_modulo_t Class Reference

Allows to execute x % mod for a specified mod in a fast way, without using a slow operation of division. More...

#include <ut0math.h>

Public Member Functions
	fast_modulo_t ()=default
	fast_modulo_t (uint64_t mod)
	fast_modulo_t (uint64_t mod, uint64_t inv)
uint64_t	compute (uint64_t x) const
	Computes the value of x % mod. More...
uint64_t	get_inverse () const
	Gets the precomputed value of inverse. More...
uint64_t	get_mod () const
	Gets the modulo value. More...

Static Public Member Functions
static uint64_t	precompute_inv (uint64_t mod)
	Precomputes the inverse needed for fast modulo operations. More...

Private Attributes
uint64_t	m_mod {0}
uint64_t	m_inv {0}

Detailed Description

Allows to execute x % mod for a specified mod in a fast way, without using a slow operation of division.

The additional cost is hidden in constructor to preprocess the mod constant.

Constructor & Destructor Documentation

fast_modulo_t() [1/3]

ut::fast_modulo_t::fast_modulo_t ( )

default

fast_modulo_t() [2/3]

ut::fast_modulo_t::fast_modulo_t ( uint64_t  mod )

inlineexplicit

fast_modulo_t() [3/3]

ut::fast_modulo_t::fast_modulo_t ( uint64_t  mod, uint64_t  inv  )

inlineexplicit

Member Function Documentation

compute()

uint64_t ut::fast_modulo_t::compute ( uint64_t  x ) const

inline

Computes the value of x % mod.

get_inverse()

uint64_t ut::fast_modulo_t::get_inverse ( ) const

inline

Gets the precomputed value of inverse.

get_mod()

uint64_t ut::fast_modulo_t::get_mod ( ) const

inline

Gets the modulo value.

precompute_inv()

static uint64_t ut::fast_modulo_t::precompute_inv ( uint64_t  mod )

inlinestatic

Precomputes the inverse needed for fast modulo operations.

Member Data Documentation

m_inv

uint64_t ut::fast_modulo_t::m_inv {0}

private

m_mod

uint64_t ut::fast_modulo_t::m_mod {0}

private

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The documentation for this class was generated from the following file:

• storage/innobase/include/ut0math.h