dtfft_pencil – dtFFT

This module describes private pencil and public dtfft_pencil_t classes

Uses

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Used by

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Graph Key

Nodes of different colours represent the following:

Solid arrows point from a submodule to the (sub)module which it is descended from. Dashed arrows point from a module or program unit to modules which it uses.
Where possible, edges connecting nodes are given different colours to make them easier to distinguish in large graphs.

Interfaces

public interface dtfft_pencil_t

Type bound constuctor for dtfft_pencil_t

private function create_pencil_t(starts, counts)

Creates pencil object, that can be used to create dtFFT plans

Arguments

Type	Intent	Optional	Attributes		Name
integer(kind=int32),	intent(in)			::	starts(:)	Local starts, starting from 0 for both C and Fortran
integer(kind=int32),	intent(in)			::	counts(:)	Local counts of data, in elements

Return Value type(dtfft_pencil_t)

Derived Types

type, public :: dtfft_pencil_t

Structure to hold pencil decomposition info

Components

Type	Visibility	Attributes		Name		Initial
integer(kind=int8),	public		::	dim			Aligned dimension id
integer(kind=int8),	public		::	ndims	=	0	Number of dimensions
integer(kind=int32),	public,	allocatable	::	starts(:)			Local starts, starting from 0 for both C and Fortran
integer(kind=int32),	public,	allocatable	::	counts(:)			Local counts of data, in elements
integer(kind=int64),	public		::	size			Total number of elements in a pencil
logical,	private		::	is_created	=	.false.	Is pencil created

Constructor

Type bound constuctor for dtfft_pencil_t

private function create_pencil_t (starts, counts)	Creates pencil object, that can be used to create dtFFT plans

Type-Bound Procedures

procedure, private, pass(self) :: destroy => destroy_pencil_t_private	../../ Destroys pencil

type, public, bind(C) :: dtfft_pencil_c

Structure to hold pencil decomposition info

Components

Type	Visibility		Name
integer(kind=c_int8_t),	public	::	dim	Aligned dimension id
integer(kind=c_int8_t),	public	::	ndims	Number of dimensions
integer(kind=c_int32_t),	public	::	starts(3)	Local starts, starting from 0 for both C and Fortran
integer(kind=c_int32_t),	public	::	counts(3)	Local counts of data, in elements
integer(kind=c_size_t),	public	::	size	Total number of elements in a pencil

type, public :: pencil

Class that describes information about data layout

Components

Type	Visibility	Attributes		Name
integer(kind=int8),	public		::	aligned_dim	Position of aligned dimension. For example: X pencil aligned_dim = 1, Z pencil aligned_dim = 3
integer(kind=int8),	public		::	rank	Rank of buffer: 2 or 3
integer(kind=int32),	public,	allocatable	::	starts(:)	Local starts, starting from 0 for both C and Fortran
integer(kind=int32),	public,	allocatable	::	counts(:)	Local counts of data, in elements
logical,	public		::	is_even	Is data evenly distributed across processes

Type-Bound Procedures

procedure, public, pass(self) :: create	../../ Creates pencil
procedure, public, pass(self) :: destroy	../../ Destroys pencil
procedure, public, pass(self) :: make_public	../../ Creates public object that users can use to create own FFT backends

type, public :: pencil_init

Class that describes information about data layout

Components

Type	Visibility	Attributes		Name
type(MPI_Comm),	public,	allocatable	::	comms(:)	1D communicators for each dimension
integer(kind=int32),	public,	allocatable	::	starts(:)	Local starts
integer(kind=int32),	public,	allocatable	::	counts(:)	Local counts
integer(kind=int32),	public,	allocatable	::	dims(:)	Global dimensions of entire region

Type-Bound Procedures

procedure, public, pass(self) :: create => create_pencil_init	../../ Creates and validates pencil passed by user to plan constructors
procedure, public, pass(self) :: destroy => destroy_pencil_init	../../ Destroys pencil_init

Functions

public pure function get_transpose_type(send, recv) result(transpose_type)

Determines transpose ID based on pencils

Arguments

Type	Intent	Optional	Attributes		Name
type(pencil),	intent(in)			::	send	Send pencil
type(pencil),	intent(in)			::	recv	Receive pencil

Return Value type(dtfft_transpose_t)

Transpose ID

private function check_if_even(count, comm)

Checks if data is evenly distributed across processes

Arguments

Type	Intent	Optional	Attributes		Name
integer(kind=int32),	intent(in)			::	count	Local count
type(MPI_Comm),	intent(in)			::	comm	Grid communicator

Return Value logical

private function make_public(self)

Creates public object that users can use to create own FFT backends

Arguments

Type	Intent	Optional	Attributes		Name
class(pencil),	intent(in)			::	self	Pencil

Return Value type(dtfft_pencil_t)

private function create_pencil_t(starts, counts)

Creates pencil object, that can be used to create dtFFT plans

Arguments

Type	Intent	Optional	Attributes		Name
integer(kind=int32),	intent(in)			::	starts(:)	Local starts, starting from 0 for both C and Fortran
integer(kind=int32),	intent(in)			::	counts(:)	Local counts of data, in elements

Return Value type(dtfft_pencil_t)

private function create_pencil_init(self, pencil, comm) result(error_code)

Creates and validates pencil passed by user to plan constructors

Arguments

Type	Intent		Name
class(pencil_init),	intent(inout)	::	self	Internal pencil representation based on dtfft_pencil_t
type(dtfft_pencil_t),	intent(in)	::	pencil	Pencil passed by user to plan constructors
type(MPI_Comm),	intent(in)	::	comm	MPI Communicator passed to plan constructors

Return Value integer(kind=int32)

Error code

private pure function check_overlap(lbounds1, sizes1, lbounds2, sizes2, ndims)

Check if two pencols overlap in ndims-dimensional space

Arguments

Type	Intent		Name
integer(kind=int32),	intent(in)	::	lbounds1(:)	Lower bounds of first pencil
integer(kind=int32),	intent(in)	::	sizes1(:)	Sizes of first pencil
integer(kind=int32),	intent(in)	::	lbounds2(:)	Lower bounds of second pencil
integer(kind=int32),	intent(in)	::	sizes2(:)	Sizes of second pencil
integer(kind=int32),	intent(in)	::	ndims	Number of dimensions

Return Value logical

private function check_continuity(all_lbounds, all_sizes, global_dims, comm_size)

Check if the local pencils cover the global space without gaps

Arguments

Type	Intent		Name
integer(kind=int32),	intent(in)	::	all_lbounds(:,:)	Lower bounds of local pencils for each process
integer(kind=int32),	intent(in)	::	all_sizes(:,:)	Sizes of local pencils for each process
integer(kind=int32),	intent(in)	::	global_dims(:)	Global dimensions of the problem
integer(kind=int32),	intent(in)	::	comm_size	Number of processes in the communicator

Return Value logical

private function get_varying_dim(fixed_dims, total_dims) result(varying_dim)

Arguments

Type	Intent	Optional	Attributes		Name
integer(kind=int32),	intent(in)			::	fixed_dims(:)
integer(kind=int32),	intent(in)			::	total_dims

Return Value integer(kind=int32)

Subroutines

public subroutine pencil_f2c(pencil, c_pencil)

Converts Fortran pencil to C pencil

Arguments

Type	Intent	Optional	Attributes		Name
type(dtfft_pencil_t),	intent(in)			::	pencil	Fortran pencil
type(dtfft_pencil_c),	intent(out)			::	c_pencil	C pencil

public subroutine pencil_c2f(c_pencil, pencil, error_code)

Converts C pencil to Fortran pencil

Arguments

Type	Intent		Name
type(dtfft_pencil_c),	intent(in)	::	c_pencil	C pencil
type(dtfft_pencil_t),	intent(out)	::	pencil	Fortran pencil
integer(kind=int32),	intent(out)	::	error_code	Error code

public subroutine get_local_sizes(pencils, in_starts, in_counts, out_starts, out_counts, alloc_size, is_y_slab)

Obtain local starts and counts in real and fourier spaces

Arguments

Type	Intent	Optional		Name
type(pencil),	intent(in)		::	pencils(:)	Array of pencils
integer(kind=int32),	intent(out),	optional	::	in_starts(:)	Start indexes in `real` space (0-based)
integer(kind=int32),	intent(out),	optional	::	in_counts(:)	Number of elements in `real` space
integer(kind=int32),	intent(out),	optional	::	out_starts(:)	Start indexes in `fourier` space (0-based)
integer(kind=int32),	intent(out),	optional	::	out_counts(:)	Number of elements in `fourier` space
integer(kind=int64),	intent(out),	optional	::	alloc_size	Minimal number of elements required to execute plan
logical,	intent(in),	optional	::	is_y_slab	Is Y-slab optimization used

private subroutine create(self, rank, aligned_dim, counts, comms, lstarts, lcounts, order)

Creates pencil

Arguments

Type	Intent	Optional		Name
class(pencil),	intent(inout)		::	self	Pencil
integer(kind=int8),	intent(in)		::	rank	Rank of buffer
integer(kind=int8),	intent(in)		::	aligned_dim	Position of aligned dimension
integer(kind=int32),	intent(in)		::	counts(:)	Global counts
type(MPI_Comm),	intent(in)		::	comms(:)	Grid communicators
integer(kind=int32),	intent(in),	optional	::	lstarts(:)	Local starts
integer(kind=int32),	intent(in),	optional	::	lcounts(:)	Local counts
integer(kind=int8),	intent(in),	optional	::	order(:)	Order of dimensions

private subroutine destroy(self)

Destroys pencil

Arguments

Type	Intent	Optional	Attributes		Name
class(pencil),	intent(inout)			::	self	Pencil

private subroutine get_local_size(n_global, comm, start, count, start_to_keep, size_to_keep)

Computes local portions of data based on global count and position inside grid communicator

Arguments

Type	Intent	Optional		Name
integer(kind=int32),	intent(in)		::	n_global	Global number of points
type(MPI_Comm),	intent(in)		::	comm	Grid communicator
integer(kind=int32),	intent(out)		::	start	Local start
integer(kind=int32),	intent(out)		::	count	Local count
integer(kind=int32),	intent(in),	optional	::	start_to_keep	Start to keep in case of user defined decomposition
integer(kind=int32),	intent(in),	optional	::	size_to_keep	Size to keep in case of user defined decomposition

private subroutine destroy_pencil_t_private(self)

Destroys pencil

Arguments

Type	Intent	Optional	Attributes		Name
class(dtfft_pencil_t),	intent(inout)			::	self	Public pencil

private subroutine destroy_pencil_t(self)

Destroys pencil

Arguments

Type	Intent	Optional	Attributes		Name
type(dtfft_pencil_t),	intent(inout)			::	self	Public pencil

private subroutine destroy_pencil_init(self)

Destroys pencil_init

Arguments

Type	Intent	Optional	Attributes		Name
class(pencil_init),	intent(inout)			::	self	Internal pencil representation based on dtfft_pencil_t

private subroutine sort_by_varying_dim(ranks, coords)

Arguments

Type	Intent	Optional	Attributes		Name
integer(kind=int32),	intent(inout)			::	ranks(:)
integer(kind=int32),	intent(in)			::	coords(:)

private subroutine create_1d_comm(lbounds, all_lbounds, fixed_dims, comm, new_comm)

Creates a new 1D communicator based on the fixed dimensions of the current pencil

Arguments

Type	Intent		Name
integer(kind=int32),	intent(in)	::	lbounds(:)	Local starts of the current pencil
integer(kind=int32),	intent(in)	::	all_lbounds(:,:)	Local starts of all processes
integer(kind=int32),	intent(in)	::	fixed_dims(:)	Indices of fixed coordinates
type(MPI_Comm),	intent(in)	::	comm	Original MPI communicator
type(MPI_Comm),	intent(out)	::	new_comm	New 1D MPI communicator

dtfft_pencil Module

Contents

Interfaces

Derived Types

Functions

Subroutines

Uses

Used by

Interfaces

public interface dtfft_pencil_t

private function create_pencil_t(starts, counts)

Arguments

Return Value type(dtfft_pencil_t)

Derived Types

type, public :: dtfft_pencil_t

Components

Constructor

Type-Bound Procedures

type, public, bind(C) :: dtfft_pencil_c

Components

type, public :: pencil

Components

Type-Bound Procedures

type, public :: pencil_init

Components

Type-Bound Procedures

Functions

public pure function get_transpose_type(send, recv) result(transpose_type)

Arguments

Return Value type(dtfft_transpose_t)

private function check_if_even(count, comm)

Arguments

Return Value logical

private function make_public(self)

Arguments

Return Value type(dtfft_pencil_t)

private function create_pencil_t(starts, counts)

Arguments

Return Value type(dtfft_pencil_t)

private function create_pencil_init(self, pencil, comm) result(error_code)

Arguments

Return Value integer(kind=int32)

private pure function check_overlap(lbounds1, sizes1, lbounds2, sizes2, ndims)

Arguments

Return Value logical

private function check_continuity(all_lbounds, all_sizes, global_dims, comm_size)

Arguments

Return Value logical

private function get_varying_dim(fixed_dims, total_dims) result(varying_dim)

Arguments

Return Value integer(kind=int32)

Subroutines

public subroutine pencil_f2c(pencil, c_pencil)

Arguments

public subroutine pencil_c2f(c_pencil, pencil, error_code)

Arguments

public subroutine get_local_sizes(pencils, in_starts, in_counts, out_starts, out_counts, alloc_size, is_y_slab)

Arguments

private subroutine create(self, rank, aligned_dim, counts, comms, lstarts, lcounts, order)

Arguments

private subroutine destroy(self)

Arguments

private subroutine get_local_size(n_global, comm, start, count, start_to_keep, size_to_keep)

Arguments

private subroutine destroy_pencil_t_private(self)

Arguments

private subroutine destroy_pencil_t(self)

Arguments

private subroutine destroy_pencil_init(self)

Arguments

private subroutine sort_by_varying_dim(ranks, coords)

Arguments

private subroutine create_1d_comm(lbounds, all_lbounds, fixed_dims, comm, new_comm)

Arguments