Routines, row decomposition, data structures and communication for the 3D-FFT. More...

#include "fft.hpp"
#include "vector.hpp"
#include "p3m/packing.hpp"
#include <utils/Vector.hpp>
#include <utils/index.hpp>
#include <utils/math/permute_ifield.hpp>
#include <utils/mpi/cart_comm.hpp>
#include <boost/mpi/communicator.hpp>
#include <boost/serialization/vector.hpp>
#include <fftw3.h>
#include <algorithm>
#include <cmath>
#include <cstddef>
#include <cstdio>
#include <cstring>
#include <optional>
#include <span>
#include <stdexcept>
#include <utility>
#include <vector>

Include dependency graph for fft.cpp:

Go to the source code of this file.

Classes
struct	fft::fftw< FloatType >

struct	fft::fftw< float >

Namespaces
namespace	fft

namespace	fft::anonymous_namespace{fft.cpp}

Macros
MPI tags for FFT communication
#define	REQ_FFT_FORW 301
	Tag for communication in forw_grid_comm()

#define	REQ_FFT_BACK 302
	Tag for communication in back_grid_comm()

Functions
template<typename T >
static void	fft_sendrecv (T const const sendbuf, int scount, int dest, T const recvbuf, int rcount, int source, boost::mpi::communicator const &comm, int tag)

std::optional< std::vector< int > >	fft::find_comm_groups (Utils::Vector3i const &grid1, Utils::Vector3i const &grid2, std::span< int const > node_list1, std::span< int > node_list2, std::span< int > pos, std::span< int > my_pos, int rank)
	This ugly function does the bookkeeping: which nodes have to communicate to each other, when you change the node grid.

int	fft::anonymous_namespace{fft.cpp}::calc_local_mesh (const int n_pos, const int n_grid, const int mesh, const double mesh_off, int loc_mesh, int start)
	Calculate the local fft mesh.

int	fft::anonymous_namespace{fft.cpp}::calc_send_block (const int pos1, const int grid1, const int pos2, const int grid2, const int mesh, const double mesh_off, int *block)
	Calculate a send (or recv.) block for grid communication during a decomposition change.

template<typename FloatType >
void	fft::anonymous_namespace{fft.cpp}::pack_block_permute1 (FloatType const const in, FloatType const out, const int start, const int size, const int *dim, int element)
	Pack a block with dimensions `size[0] * size[1] * size[2]` starting at `start` of an input 3D-grid with dimension `dim` into an output 3D-grid with dimensions `size[2] * size[0] * size[1]` with a simultaneous one-fold permutation of the indices.

template<typename FloatType >
void	fft::anonymous_namespace{fft.cpp}::pack_block_permute2 (FloatType const const in, FloatType const out, const int start, const int size, const int *dim, int element)
	Pack a block with dimensions `size[0] * size[1] * size[2]` starting at `start` of an input 3D-grid with dimension `dim` into an output 3D-grid with dimensions `size[2] * size[0] * size[1]` with a simultaneous two-fold permutation of the indices.

int	fft::map_3don2d_grid (int const g3d[3], int g2d[3])
	Calculate 'best' mapping between a 2D and 3D grid.

void	fft::calc_2d_grid (int n, int grid[3])
	Calculate most square 2D grid.

Detailed Description

Routines, row decomposition, data structures and communication for the 3D-FFT.

Definition in file fft.cpp.

Macro Definition Documentation

◆ REQ_FFT_BACK

#define REQ_FFT_BACK 302

Tag for communication in back_grid_comm()

Definition at line 65 of file fft.cpp.

◆ REQ_FFT_FORW

#define REQ_FFT_FORW 301

Tag for communication in forw_grid_comm()

Definition at line 63 of file fft.cpp.

Function Documentation

◆ fft_sendrecv()

template<typename T >

static void fft_sendrecv	(	T const *const	sendbuf,
		int	scount,
		int	dest,
		T *const	recvbuf,
		int	rcount,
		int	source,
		boost::mpi::communicator const &	comm,
		int	tag
	)

static

Definition at line 69 of file fft.cpp.

References stream.

Classes

Namespaces