A Descriptor of the Real Type. More...

#include <AMReX_FabConv.H>

Public Member Functions
	RealDescriptor ()=default
	The default constructor. Does not build a proper RealDescriptor. This should only be used when you need to build a generic RealDescriptor in order to be able to read in a specific one from an istream.

	RealDescriptor (const Long fr_, const int ord_, int ordl_)
	Construct a specific RealDescriptor, passing in the format of the Real, the order of the Real, and the length of the array detailing the ordering.

const Long *	format () const &
	Returns the format array as a const Long*.

const Long *	format () &&=delete

const Vector< Long > &	formatarray () const &
	Returns const Vector<Long> reference to the format array.

const Vector< Long > &	formatarray () &&=delete

const int *	order () const &
	Returns the order array as a const int*.

const int *	order () &&=delete

const Vector< int > &	orderarray () const &
	Returns const Vector<int> reference to the order array.

const Vector< int > &	orderarray () &&=delete

int	numBytes () const
	Returns the number of bytes in the Real.

bool	operator== (const RealDescriptor &rd) const
	The equality operator.

bool	operator!= (const RealDescriptor &rd) const
	The inequality operator.

RealDescriptor *	clone () const
	Returns a copy of this RealDescriptor on the heap. The user is responsible for deletion.

Static Public Member Functions
static void	SetFixDenormals ()
	Set to always fix denormals when converting to native format.

static void	SetReadBufferSize (int rbs)
	Set read and write buffer sizes.

static void	SetWriteBufferSize (int wbs)

static RealDescriptor *	newRealDescriptor (int fmt, int prec, const char *systype, int ordering)
	Returns a RealDescriptor on the heap detailing requested floating-point type. Here format, precision, and ordering correspond to the enumerations in FABio. This is here to support reading "old" FABs. Do NOT use it in new code.

static void	convertToNativeFormat (Real out, Long nitems, void in, const RealDescriptor &id)
	Convert serialized bytes in descriptor format to native Real values.

static void	convertToNativeFormat (Real *out, Long nitems, std::istream &is, const RealDescriptor &id)
	Read descriptor-formatted bytes from a stream and convert them to native Reals.

static void	convertFromNativeFormat (std::ostream &os, Long nitems, const Real *in, const RealDescriptor &od)
	Serialize native Reals to descriptor format and write them to an ostream.

static void	convertFromNativeFormat (void out, Long nitems, const void in, const RealDescriptor &od)
	Serialize native Reals to descriptor format into a caller-provided buffer.

static void	convertFromNativeFloatFormat (std::ostream &os, Long nitems, const float *in, const RealDescriptor &od)
	Serialize single-precision values to descriptor format and write them to `os`.

static void	convertFromNativeDoubleFormat (std::ostream &os, Long nitems, const double *in, const RealDescriptor &od)
	Serialize double-precision values to descriptor format and write them to `os`.

static void	convertToNativeFloatFormat (float *out, Long nitems, std::istream &is, const RealDescriptor &id)
	Read descriptor-formatted bytes and convert them to native floats.

static void	convertToNativeDoubleFormat (double *out, Long nitems, std::istream &is, const RealDescriptor &id)
	Read descriptor-formatted bytes and convert them to native doubles.

Detailed Description

A Descriptor of the Real Type.

This class is meant to hold all information needed to completely describe the "Real" floating-point type on a machine. By "Real" here we mean either the "float" or "double" type that this version of AMReX was built with, which corresponds to whether BL_USE_FLOAT or BL_USE_DOUBLE was used to build the version of the library.

To describe a "Real" type two arrays are needed: one detailing the ordering of the bytes in the Real, relative to the canonical ordering 1 .. sizeof(Real) and the other detailing the format of the floating-point number.

The array detailing the format of a floating-point number is an eight-element array of longs containing the following information:

    format[0] = number of bits per number
    format[1] = number of bits in exponent
    format[2] = number of bits in mantissa
    format[3] = start bit of sign
    format[4] = start bit of exponent
    format[5] = start bit of mantissa
    format[6] = high order mantissa bit (CRAY needs this)
    format[7] = bias of exponent

This allows us to write out "Real"s in the native format on a machine, and then by also saving the IntDescriptor, we can read them back in on another machine and have enough information to construct the exact same "Real" values, provided the Reals have the same size on the two machines.

Constructor & Destructor Documentation

◆ RealDescriptor() [1/2]

amrex::RealDescriptor::RealDescriptor ( )

default

The default constructor. Does not build a proper RealDescriptor. This should only be used when you need to build a generic RealDescriptor in order to be able to read in a specific one from an istream.

◆ RealDescriptor() [2/2]

amrex::RealDescriptor::RealDescriptor	(	const Long *	fr_,
		const int *	ord_,
		int	ordl_
	)

Construct a specific RealDescriptor, passing in the format of the Real, the order of the Real, and the length of the array detailing the ordering.

Member Function Documentation

◆ clone()

RealDescriptor * amrex::RealDescriptor::clone ( ) const

Returns a copy of this RealDescriptor on the heap. The user is responsible for deletion.

◆ convertFromNativeDoubleFormat()

void amrex::RealDescriptor::convertFromNativeDoubleFormat	(	std::ostream &	os,
		Long	nitems,
		const double *	in,
		const RealDescriptor &	od
	)

static

Serialize double-precision values to descriptor format and write them to os.

Parameters

os	Output stream receiving the serialized bytes.
nitems	Number of entries to convert.
in	Pointer to `nitems` native double values.
od	Descriptor describing the target layout.

◆ convertFromNativeFloatFormat()

void amrex::RealDescriptor::convertFromNativeFloatFormat	(	std::ostream &	os,
		Long	nitems,
		const float *	in,
		const RealDescriptor &	od
	)

static

Serialize single-precision values to descriptor format and write them to os.

Parameters

os	Output stream receiving the serialized bytes.
nitems	Number of entries to convert.
in	Pointer to `nitems` native float values.
od	Descriptor describing the target layout.

◆ convertFromNativeFormat() [1/2]

void amrex::RealDescriptor::convertFromNativeFormat	(	std::ostream &	os,
		Long	nitems,
		const Real *	in,
		const RealDescriptor &	od
	)

static

Serialize native Reals to descriptor format and write them to an ostream.

Parameters

os	Output stream receiving the serialized bytes.
nitems	Number of entries to convert.
in	Pointer to native Real data.
od	Descriptor describing the target layout.

◆ convertFromNativeFormat() [2/2]

void amrex::RealDescriptor::convertFromNativeFormat	(	void *	out,
		Long	nitems,
		const void *	in,
		const RealDescriptor &	od
	)

static

Serialize native Reals to descriptor format into a caller-provided buffer.

Parameters

out	Destination buffer sized for the descriptor-formatted bytes.
nitems	Number of entries to convert.
in	Pointer to native Real data.
od	Descriptor describing the target layout.

◆ convertToNativeDoubleFormat()

void amrex::RealDescriptor::convertToNativeDoubleFormat	(	double *	out,
		Long	nitems,
		std::istream &	is,
		const RealDescriptor &	id
	)

static

Read descriptor-formatted bytes and convert them to native doubles.

Parameters

out	Destination array sized for `nitems` double values.
nitems	Number of entries to convert.
is	Input stream containing descriptor-formatted bytes.
id	Descriptor of the serialized input.

◆ convertToNativeFloatFormat()

void amrex::RealDescriptor::convertToNativeFloatFormat	(	float *	out,
		Long	nitems,
		std::istream &	is,
		const RealDescriptor &	id
	)

static

Read descriptor-formatted bytes and convert them to native floats.

Parameters

out	Destination array sized for `nitems` float values.
nitems	Number of entries to convert.
is	Input stream containing descriptor-formatted bytes.
id	Descriptor of the serialized input.

◆ convertToNativeFormat() [1/2]

void amrex::RealDescriptor::convertToNativeFormat	(	Real *	out,
		Long	nitems,
		std::istream &	is,
		const RealDescriptor &	id
	)

static

Read descriptor-formatted bytes from a stream and convert them to native Reals.

Parameters

out	Destination array sized for `nitems` native values.
nitems	Number of entries to translate.
is	Input stream containing descriptor-formatted bytes.
id	Descriptor describing the serialized byte order/format.

◆ convertToNativeFormat() [2/2]

void amrex::RealDescriptor::convertToNativeFormat	(	Real *	out,
		Long	nitems,
		void *	in,
		const RealDescriptor &	id
	)

static

Convert serialized bytes in descriptor format to native Real values.

Parameters

out	Destination array sized for `nitems` native values.
nitems	Number of entries to translate.
in	Pointer to the serialized payload laid out per `id`.
id	Descriptor describing the serialized byte order/format.

◆ format() [1/2]

const Long * amrex::RealDescriptor::format ( ) &&

delete

◆ format() [2/2]

const Long * amrex::RealDescriptor::format ( ) const &

Returns the format array as a const Long*.

◆ formatarray() [1/2]

const Vector< Long > & amrex::RealDescriptor::formatarray ( ) &&

delete

◆ formatarray() [2/2]

const Vector< Long > & amrex::RealDescriptor::formatarray ( ) const &

Returns const Vector<Long> reference to the format array.

◆ newRealDescriptor()

RealDescriptor * amrex::RealDescriptor::newRealDescriptor	(	int	fmt,
		int	prec,
		const char *	systype,
		int	ordering
	)

static

Returns a RealDescriptor on the heap detailing requested floating-point type. Here format, precision, and ordering correspond to the enumerations in FABio. This is here to support reading "old" FABs. Do NOT use it in new code.

◆ numBytes()

int amrex::RealDescriptor::numBytes ( ) const

Returns the number of bytes in the Real.

◆ operator!=()

bool amrex::RealDescriptor::operator!= ( const RealDescriptor & rd ) const

The inequality operator.

◆ operator==()

bool amrex::RealDescriptor::operator== ( const RealDescriptor & rd ) const

The equality operator.

◆ order() [1/2]

const int * amrex::RealDescriptor::order ( ) &&

delete

◆ order() [2/2]

const int * amrex::RealDescriptor::order ( ) const &

Returns the order array as a const int*.

◆ orderarray() [1/2]

const Vector< int > & amrex::RealDescriptor::orderarray ( ) &&

delete

◆ orderarray() [2/2]

const Vector< int > & amrex::RealDescriptor::orderarray ( ) const &

Returns const Vector<int> reference to the order array.

◆ SetFixDenormals()

void amrex::RealDescriptor::SetFixDenormals ( )

static

Set to always fix denormals when converting to native format.

◆ SetReadBufferSize()

void amrex::RealDescriptor::SetReadBufferSize ( int rbs )

static

Set read and write buffer sizes.

◆ SetWriteBufferSize()

void amrex::RealDescriptor::SetWriteBufferSize ( int wbs )

static

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

/home/runner/work/amrex/amrex/Src/Base/AMReX_FabConv.H
/home/runner/work/amrex/amrex/Src/Base/AMReX_FabConv.cpp

Public Member Functions

Static Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ RealDescriptor() [1/2]

◆ RealDescriptor() [2/2]

Member Function Documentation

◆ clone()

◆ convertFromNativeDoubleFormat()

◆ convertFromNativeFloatFormat()

◆ convertFromNativeFormat() [1/2]

◆ convertFromNativeFormat() [2/2]

◆ convertToNativeDoubleFormat()

◆ convertToNativeFloatFormat()

◆ convertToNativeFormat() [1/2]

◆ convertToNativeFormat() [2/2]

◆ format() [1/2]

◆ format() [2/2]

◆ formatarray() [1/2]

◆ formatarray() [2/2]

◆ newRealDescriptor()

◆ numBytes()

◆ operator!=()

◆ operator==()

◆ order() [1/2]

◆ order() [2/2]

◆ orderarray() [1/2]

◆ orderarray() [2/2]

◆ SetFixDenormals()

◆ SetReadBufferSize()

◆ SetWriteBufferSize()