FieldAXPY< Field > Class Template Reference

FieldAXPY object. More...

#include <field-axpy.h>

Public Types
typedef Field::Element	Element
	Definition of element type.

Public Member Functions
	FieldAXPY (const Field &F)
	Constructor. More...
	FieldAXPY (const FieldAXPY< Field > &faxpy)
	Copy constructor. More...
FieldAXPY< Field > &	operator= (const FieldAXPY< Field > &faxpy)
	Assignment operator. More...
Element &	mulacc (const Element &a, const Element &x)
	Add a*x to y y += a*x. More...
Element &	get (Element &y) const
	Retrieve y. More...
void	reset ()
	reset value to zero.

Protected Attributes
const Field *	_field
	Field in which arithmetic is done.
Abnormal	_y
	Accumulator, unnormalized field element.

Detailed Description

template<class Field>
class LinBox::FieldAXPY< Field >

FieldAXPY object.

A fieldAXPY is an accumulator, allowing to add a number of field elements or products in an unnormalized state, delaying modular reduction as long as possible. This class containse a value y and wraps the operations y = y + a * x and y = y + a.

This default instance does no optimization, no delayed modular reduction. Through the use of template specialization, objects of this type can be used to speed up operations such as vector dot product operations. In particular, for finite fields, dividing by the modulus and taking the remainder is expensive. In many cases, this can be postponed until the end of the dot product operation, thus vastly improving performance.

FieldAXPY<Fld> is an assignable type. It is constructed from a field instance. The methods are mulacc(), accumulate(), operator=(), reset(), get(), and field(). Of a const instance you can access get() and field(). [Note: get() may renormalize the value, but it remains constant as a field element.]

Parameters

Field

LinBox field

Constructor & Destructor Documentation

FieldAXPY() [1/2]

FieldAXPY ( const Field &  F )

inline

Constructor.

Parameters

F	field F in which arithmetic is done

FieldAXPY() [2/2]

FieldAXPY ( const FieldAXPY< Field > &  faxpy )

inline

Copy constructor.

Parameters

faxpy

Member Function Documentation

operator=()

FieldAXPY<Field>& operator= ( const FieldAXPY< Field > &  faxpy )

inline

Assignment operator.

Parameters

faxpy

mulacc()

Element& mulacc ( const Element &  a, const Element &  x  )

inline

Add a*x to y y += a*x.

Parameters

a	constant reference to element a
x	constant reference to element x

get()

Element& get ( Element &  y ) const

inline

Retrieve y.

Performs the delayed modding out if necessary

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

• modular-byte.h
• field-axpy.h