util::math::ConstantDivisor< uint32_t > Class Reference

Division and modulus using uint32_t numerators and denominators. More...

#include <constant_divisor.h>

Inheritance diagram for util::math::ConstantDivisor< uint32_t >:

Public Types
using	value_type = uint32_t
typedef uint32_t	value_type
Public Types inherited from util::math::internal::ConstantDivisorBase< uint32_t, uint64_t, ConstantDivisor< uint32_t > >
using	value_type

Public Member Functions
	ConstantDivisor (value_type denominator)
	REQUIRES: denominator > 1.
value_type	div (value_type numerator) const
	ConstantDivisor (value_type denominator)
value_type	div (value_type n) const
value_type	mod (value_type n) const
Public Member Functions inherited from util::math::internal::ConstantDivisorBase< uint32_t, uint64_t, ConstantDivisor< uint32_t > >
	ConstantDivisorBase (uint64_t magic, value_type denominator)
value_type	mod (value_type numerator) const
value_type	denominator () const

Friends
value_type	operator/ (value_type a, const ConstantDivisor &b)
value_type	operator% (value_type a, const ConstantDivisor &b)

Additional Inherited Members
Protected Types inherited from util::math::internal::ConstantDivisorBase< uint32_t, uint64_t, ConstantDivisor< uint32_t > >
using	MagicValueType
Protected Attributes inherited from util::math::internal::ConstantDivisorBase< uint32_t, uint64_t, ConstantDivisor< uint32_t > >
uint64_t	magic_

Detailed Description

Division and modulus using uint32_t numerators and denominators.

Definition at line 137 of file constant_divisor.h.

Member Typedef Documentation

value_type [1/2]

typedef uint32_t util::math::ConstantDivisor< uint32_t >::value_type

Definition at line 59 of file constant_divisor.h.

value_type [2/2]

using util::math::ConstantDivisor< uint32_t >::value_type = uint32_t

Definition at line 141 of file constant_divisor.h.

Constructor & Destructor Documentation

ConstantDivisor() [1/2]

util::math::ConstantDivisor< uint32_t >::ConstantDivisor ( value_type d )

explicit

REQUIRES: denominator > 1.

If we hardcode shift_amount to 32, the 32-bit formula is: magic_number = 2 ^ 64 / d value / d = value * magic_number >> 64

One caveat is that for d == 1, magic_number takes 65 bits overflowing a uint64_t. So, we again disallow inputs with d == 1.

Definition at line 39 of file constant_divisor.cc.

ConstantDivisor() [2/2]

util::math::ConstantDivisor< uint32_t >::ConstantDivisor ( value_type denominator )

inlineexplicit

Definition at line 61 of file constant_divisor.h.

Member Function Documentation

div() [1/2]

value_type util::math::ConstantDivisor< uint32_t >::div ( value_type n ) const

inline

Definition at line 64 of file constant_divisor.h.

div() [2/2]

value_type util::math::ConstantDivisor< uint32_t >::div ( value_type numerator ) const

inline

Definition at line 146 of file constant_divisor.h.

mod()

value_type util::math::ConstantDivisor< uint32_t >::mod ( value_type n ) const

inline

Definition at line 66 of file constant_divisor.h.

Friends And Related Symbol Documentation

operator%

value_type operator% ( value_type a, const ConstantDivisor< uint32_t > & b )

friend

Definition at line 72 of file constant_divisor.h.

operator/

value_type operator/ ( value_type a, const ConstantDivisor< uint32_t > & b )

friend

Definition at line 68 of file constant_divisor.h.

---

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

• ortools/base/constant_divisor.h
• ortools/base/constant_divisor.cc