Wave-fucntions in the FFT-friendly distribution. More...

#include <wave_functions.hpp>

Inherits sirius::wf::Wave_functions_base< T >.

Public Member Functions
	Wave_functions_fft ()
	Constructor. More...

	Wave_functions_fft (std::shared_ptr< fft::Gvec_fft > gkvec_fft__, Wave_functions< T > &wf__, spin_index s__, band_range br__, unsigned int shuffle_flag___)
	Constructor. More...

Wave_functions_fft &	operator= (Wave_functions_fft &&src__)
	Move assignment operator. More...

	~Wave_functions_fft ()
	Destructor. More...

int	num_wf_local () const
	Return local number of wave-functions. More...

auto	spl_num_wf () const
	Return the split index for the number of wave-functions. More...

std::complex< T > &	pw_coeffs (int ig__, band_index b__)
	Return reference to the plane-wave coefficient. More...

T *	pw_coeffs_spfft (sddk::memory_t mem__, band_index b__)
	Return pointer to the beginning of wave-functions casted to real type as required by the SpFFT library. More...

auto	on_device () const
	Return true if data is avaliable on the device memory. More...

std::complex< T > const *	at (sddk::memory_t mem__, int i__, band_index b__) const
	Return const pointer to the data for a given plane-wave and band indices. More...

auto	at (sddk::memory_t mem__, int i__, band_index b__)
	Return pointer to the data for a given plane-wave and band indices. More...

Public Member Functions inherited from sirius::wf::Wave_functions_base< T >
	Wave_functions_base ()
	Constructor. More...

	Wave_functions_base (int num_pw__, int num_mt__, num_mag_dims num_md__, num_bands num_wf__, sddk::memory_t default_mem__)
	Constructor. More...

auto	memory_guard (sddk::memory_t mem__, wf::copy_to copy_to__=copy_to::none) const
	Return an instance of the memory guard. More...

auto	num_sc () const
	Return number of spin components. More...

auto	num_md () const
	Return number of magnetic dimensions. More...

auto	num_wf () const
	Return number of wave-functions. More...

auto	ld () const
	Return leading dimensions of the wave-functions coefficients array. More...

auto	actual_spin_index (spin_index s__) const
	Return the actual spin index of the wave-functions. More...

void	zero (sddk::memory_t mem__, spin_index s__, band_range br__)
	Zero a spin component of the wave-functions in a band range. More...

void	zero (sddk::memory_t mem__)
	Zero all wave-functions. More...

std::complex< T > const *	at (sddk::memory_t mem__, int i__, spin_index s__, band_index b__) const
	Return const pointer to the wave-function coefficient at a given index, spin and band. More...

auto	at (sddk::memory_t mem__, int i__, spin_index s__, band_index b__)
	Return pointer to the wave-function coefficient at a given index, spin and band. More...

void	allocate (sddk::memory_t mem__)
	Allocate wave-functions. More...

void	deallocate (sddk::memory_t mem__)
	Deallocate wave-functions. More...

void	copy_to (sddk::memory_t mem__)
	Copy date to host or device. More...

Private Member Functions
auto	grid_layout (int n__)
	Return COSTA grd layout description. More...

void	shuffle_to_fft_layout (spin_index ispn__, band_range b__)
	Shuffle wave-function to the FFT distribution. More...

void	shuffle_to_wf_layout (spin_index ispn__, band_range b__)
	Shuffle wave-function to the original slab layout. More...

Private Attributes
std::shared_ptr< fft::Gvec_fft >	gkvec_fft_
	Pointer to FFT-friendly G+k vector deistribution. More...

splindex_block	spl_num_wf_
	Split number of wave-functions between column communicator. More...

Wave_functions< T > *	wf_ {nullptr}
	Pointer to the original wave-functions. More...

spin_index	s_ {0}
	Spin-index of the wave-function component. More...

band_range	br_ {0}
	Range of bands in the input wave-functions to be swapped. More...

unsigned int	shuffle_flag_ {0}
	Direction of the reshuffling: to FFT layout or back to WF layout or both. More...

bool	on_device_ {false}
	True if the FFT wave-functions are also available on the device. More...

Additional Inherited Members
Protected Attributes inherited from sirius::wf::Wave_functions_base< T >
int	num_pw_ {0}
	Local number of plane-wave coefficients. More...

int	num_mt_ {0}
	Local number of muffin-tin coefficients. More...

num_mag_dims	num_md_ {0}
	Number of magnetic dimensions (0, 1, or 3). More...

num_bands	num_wf_ {0}
	Total number of wave-functions. More...

num_spins	num_sc_ {0}
	Number of spin components (1 or 2). More...

std::array< sddk::mdarray< std::complex< T >, 2 >, 2 >	data_
	Data storage for the wave-functions. More...

Detailed Description

template<typename T>
class sirius::wf::Wave_functions_fft< T >

Wave-fucntions in the FFT-friendly distribution.

To reduce the FFT MPI communication volume, it is often beneficial to redistribute wave-functions from a default slab layout to a FFT-friendly layout. Often this is a full swap from G-vector to band distribution. In general this is a redistribution of data from [N x 1] to [M x K] MPI grids.

                 band index               band index               band index
              ┌──────────────┐          ┌───────┬──────┐          ┌───┬───┬───┬──┐
              │              │          │       │      │          │   │   │   │  │
              │              │          │       │      │          │   │   │   │  │
              ├──────────────┤          │       │      │          │   │   │   │  │
              │              │          │       │      │          │   │   │   │  │
              │              │ partial  │       │      │   full   │   │   │   │  │
              │              │  swap    │       │      │   swap   │   │   │   │  │
  G+k index   ├──────────────┤    ->    ├───────┼──────┤    ->    ├───┼───┼───┼──┤
(distributed) │              │          │       │      │          │   │   │   │  │
              │              │          │       │      │          │   │   │   │  │
              │              │          │       │      │          │   │   │   │  │
              ├──────────────┤          │       │      │          │   │   │   │  │
              │              │          │       │      │          │   │   │   │  │
              │              │          │       │      │          │   │   │   │  │
              └──────────────┘          └───────┴──────┘          └───┴───┴───┴──┘

Wave-functions in FFT distribution are scalar with only one spin component.

Template Parameters

T	Precision type of the wave-functions (double or float).

Definition at line 838 of file wave_functions.hpp.

Constructor & Destructor Documentation

◆ Wave_functions_fft() [1/2]

template<typename T >

sirius::wf::Wave_functions_fft< T >::Wave_functions_fft ( )

inline

Constructor.

Definition at line 1062 of file wave_functions.hpp.

◆ Wave_functions_fft() [2/2]

template<typename T >

sirius::wf::Wave_functions_fft< T >::Wave_functions_fft	(	std::shared_ptr< fft::Gvec_fft >	gkvec_fft__,
		Wave_functions< T > &	wf__,
		spin_index	s__,
		band_range	br__,
		unsigned int	shuffle_flag___
	)

inline

Constructor.

Definition at line 1067 of file wave_functions.hpp.

◆ ~Wave_functions_fft()

template<typename T >

sirius::wf::Wave_functions_fft< T >::~Wave_functions_fft ( )

inline

Destructor.

Definition at line 1138 of file wave_functions.hpp.

Member Function Documentation

◆ grid_layout()

template<typename T >

auto sirius::wf::Wave_functions_fft< T >::grid_layout ( int n__ )

inlineprivate

Return COSTA grd layout description.

Definition at line 857 of file wave_functions.hpp.

◆ shuffle_to_fft_layout()

template<typename T >

void sirius::wf::Wave_functions_fft< T >::shuffle_to_fft_layout	(	spin_index	ispn__,
		band_range	b__
	)

inlineprivate

Shuffle wave-function to the FFT distribution.

Definition at line 891 of file wave_functions.hpp.

◆ shuffle_to_wf_layout()

template<typename T >

void sirius::wf::Wave_functions_fft< T >::shuffle_to_wf_layout	(	spin_index	ispn__,
		band_range	b__
	)

inlineprivate

Shuffle wave-function to the original slab layout.

Definition at line 968 of file wave_functions.hpp.

◆ operator=()

template<typename T >

Wave_functions_fft & sirius::wf::Wave_functions_fft< T >::operator= ( Wave_functions_fft< T > && src__ )

inline

Move assignment operator.

Definition at line 1114 of file wave_functions.hpp.

◆ num_wf_local()

template<typename T >

int sirius::wf::Wave_functions_fft< T >::num_wf_local ( ) const

inline

Return local number of wave-functions.

Wave-function band index is distributed over the columns of MPI grid. Each group of FFT communiators is working on its local set of wave-functions.

Definition at line 1158 of file wave_functions.hpp.

◆ spl_num_wf()

template<typename T >

auto sirius::wf::Wave_functions_fft< T >::spl_num_wf ( ) const

inline

Return the split index for the number of wave-functions.

Definition at line 1164 of file wave_functions.hpp.

◆ pw_coeffs()

template<typename T >

std::complex< T > & sirius::wf::Wave_functions_fft< T >::pw_coeffs	(	int	ig__,
		band_index	b__
	)

inline

Return reference to the plane-wave coefficient.

Definition at line 1170 of file wave_functions.hpp.

◆ pw_coeffs_spfft()

template<typename T >

T * sirius::wf::Wave_functions_fft< T >::pw_coeffs_spfft	(	sddk::memory_t	mem__,
		band_index	b__
	)

inline

Return pointer to the beginning of wave-functions casted to real type as required by the SpFFT library.

Definition at line 1176 of file wave_functions.hpp.

◆ on_device()

template<typename T >

auto sirius::wf::Wave_functions_fft< T >::on_device ( ) const

inline

Return true if data is avaliable on the device memory.

Definition at line 1182 of file wave_functions.hpp.

◆ at() [1/2]

template<typename T >

std::complex< T > const * sirius::wf::Wave_functions_fft< T >::at	(	sddk::memory_t	mem__,
		int	i__,
		band_index	b__
	)		const

inline

Return const pointer to the data for a given plane-wave and band indices.

Definition at line 1189 of file wave_functions.hpp.

◆ at() [2/2]

template<typename T >

auto sirius::wf::Wave_functions_fft< T >::at	(	sddk::memory_t	mem__,
		int	i__,
		band_index	b__
	)

bool sirius::wf::Wave_functions_fft< T >::on_device_ {false}

private

True if the FFT wave-functions are also available on the device.

Definition at line 854 of file wave_functions.hpp.

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

wave_functions.hpp

Public Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ Wave_functions_fft() [1/2]

◆ Wave_functions_fft() [2/2]

◆ ~Wave_functions_fft()

Member Function Documentation

◆ grid_layout()

◆ shuffle_to_fft_layout()

◆ shuffle_to_wf_layout()

◆ operator=()

◆ num_wf_local()

◆ spl_num_wf()

◆ pw_coeffs()

◆ pw_coeffs_spfft()

◆ on_device()

◆ at() [1/2]

◆ at() [2/2]

Member Data Documentation

◆ gkvec_fft_

◆ spl_num_wf_

◆ wf_

◆ s_

◆ br_

◆ shuffle_flag_

◆ on_device_