quantum-espresso/Modules/fft_wave.f90

257 lines
7.5 KiB
Fortran

!
! Copyright (C) Quantum ESPRESSO group
!
! This file is distributed under the terms of the
! GNU General Public License. See the file `License'
! in the root directory of the present distribution,
! or http://www.gnu.org/copyleft/gpl.txt .
!
!=---------------------------------------------------------------------------=!
!
MODULE fft_wave
!
!! This module contains wrappers to FFT and inverse FFTs of the wave function,
!! which it enclose the calls to g-vect/FFT-grid transposition routines too.
!
USE kinds, ONLY: DP
USE fft_interfaces, ONLY: fwfft, invfft
USE fft_types, ONLY: fft_type_descriptor
USE control_flags, ONLY: gamma_only
!
IMPLICIT NONE
!
PRIVATE
!
PUBLIC :: wave_r2g, wave_g2r, tgwave_r2g, tgwave_g2r
!
!
CONTAINS
!
!----------------------------------------------------------------------
SUBROUTINE wave_r2g( f_in, f_out, dfft, igk, howmany_set )
!--------------------------------------------------------------------
!! Wave function FFT from R to G-space.
!
USE fft_helper_subroutines, ONLY: fftx_psi2c_gamma, fftx_psi2c_k
!
IMPLICIT NONE
!
TYPE(fft_type_descriptor), INTENT(IN) :: dfft
!! FFT descriptor
COMPLEX(DP) :: f_in(:)
!! input: r-space wave-function
COMPLEX(DP), INTENT(OUT) :: f_out(:,:)
!! output: g-space wave-function
INTEGER, OPTIONAL, INTENT(IN) :: igk(:)
!! index of G corresponding to a given index of k+G
INTEGER, OPTIONAL, INTENT(IN) :: howmany_set(3)
!! gpu-enabled only (many_fft>1 case):
!! (1) group_size;
!! (2) true dimension of psi;
!! (3) howmany (if gamma) or group_size (if k).
!
! ... local variables
INTEGER :: dim1, dim2
!
dim1 = SIZE(f_in(:))
dim2 = SIZE(f_out(1,:))
!
!$acc data present_or_copyin(f_in) present_or_copyout(f_out)
!
!$acc host_data use_device(f_in)
IF (PRESENT(howmany_set)) THEN
CALL fwfft( 'Wave', f_in, dfft, howmany=howmany_set(3) )
ELSE
CALL fwfft( 'Wave', f_in, dfft )
ENDIF
!$acc end host_data
!
IF (gamma_only) THEN
IF (PRESENT(howmany_set)) THEN
CALL fftx_psi2c_gamma( dfft, f_in, f_out, howmany_set=howmany_set(1:2) )
ELSE
IF (dim2==1) CALL fftx_psi2c_gamma( dfft, f_in, f_out(:,1:1) )
IF (dim2==2) CALL fftx_psi2c_gamma( dfft, f_in, f_out(:,1:1), &
vout2=f_out(:,2) )
ENDIF
ELSE
!$acc data present_or_copyin(igk)
IF (PRESENT(howmany_set)) THEN
CALL fftx_psi2c_k( dfft, f_in, f_out, igk, howmany_set(1:2) )
ELSE
CALL fftx_psi2c_k( dfft, f_in, f_out(:,1:1), igk )
ENDIF
!$acc end data
ENDIF
!
!$acc end data
!
RETURN
!
END SUBROUTINE wave_r2g
!
!
!----------------------------------------------------------------------
SUBROUTINE wave_g2r( f_in, f_out, dfft, igk, howmany_set )
!--------------------------------------------------------------------
!! Wave function FFT from G to R-space.
!
USE fft_helper_subroutines, ONLY: fftx_c2psi_gamma, fftx_c2psi_k
!
IMPLICIT NONE
!
TYPE(fft_type_descriptor), INTENT(IN) :: dfft
!! FFT wave descriptor
COMPLEX(DP), INTENT(IN) :: f_in(:,:)
!! input: g-space wave-function
COMPLEX(DP) :: f_out(:)
!! output: r-space wave-function
INTEGER, OPTIONAL, INTENT(IN) :: igk(:)
!! index of G corresponding to a given index of k+G
INTEGER, OPTIONAL, INTENT(IN) :: howmany_set(3)
!! gpu-enabled only (many_fft>1 case):
!! (1) group_size;
!! (2) true dimension of psi;
!! (3) howmany (if gamma) or group_size (if k).
!
! ... local variables
INTEGER :: npw, dim2
!
!$acc data present_or_copyin(f_in) present_or_copyout(f_out)
!
npw = SIZE(f_in(:,1))
dim2 = SIZE(f_in(1,:))
!
IF (gamma_only) THEN
!
IF (PRESENT(howmany_set)) THEN
CALL fftx_c2psi_gamma( dfft, f_out, f_in, howmany_set=howmany_set(1:2) )
ELSE
IF (dim2/=2) CALL fftx_c2psi_gamma( dfft, f_out, f_in(:,1:1) )
IF (dim2==2) CALL fftx_c2psi_gamma( dfft, f_out, f_in(:,1:1), ca=f_in(:,2) )
ENDIF
!
ELSE
!
!$acc data present_or_copyin(igk)
IF (PRESENT(howmany_set)) THEN !only when ACC is active
npw = howmany_set(2)
CALL fftx_c2psi_k( dfft, f_out, f_in, igk, npw, howmany_set(1) )
ELSE
CALL fftx_c2psi_k( dfft, f_out, f_in, igk, npw )
ENDIF
!$acc end data
!
ENDIF
!
!$acc host_data use_device( f_out )
IF (PRESENT(howmany_set)) THEN
CALL invfft( 'Wave', f_out, dfft, howmany=howmany_set(3) )
ELSE
CALL invfft( 'Wave', f_out, dfft )
ENDIF
!$acc end host_data
!
!$acc end data
!
RETURN
!
END SUBROUTINE wave_g2r
!
!
!----------------------------------------------------------------------
SUBROUTINE tgwave_g2r( f_in, f_out, dfft, n, igk )
!--------------------------------------------------------------------
!! Wave function FFT from G to R-space. Task-group version.
!
USE fft_helper_subroutines, ONLY: fftx_c2psi_gamma_tg, fftx_c2psi_k_tg
!
IMPLICIT NONE
!
TYPE(fft_type_descriptor), INTENT(IN) :: dfft
!! FFT descriptor
COMPLEX(DP) :: f_in(:,:)
!! input: wave in g-space - task group chunk
COMPLEX(DP) :: f_out(:)
!! output: wave in r-space - task group chunk
INTEGER, INTENT(IN) :: n
!! true dimension of f_in
INTEGER, OPTIONAL, INTENT(IN) :: igk(:)
!! index of G corresponding to a given index of k+G
!
! ... local variables
INTEGER :: npw, dbnd
!
!$acc data present_or_copyin(f_in,igk) present_or_copyout(f_out)
!
npw = SIZE(f_in(:,1))
dbnd = SIZE(f_in(1,:))
IF (n/=npw) npw = n
!
!$acc kernels
f_out(:) = (0.D0,0.D0)
!$acc end kernels
!
IF (gamma_only) THEN
CALL fftx_c2psi_gamma_tg( dfft, f_out, f_in, npw, dbnd )
ELSE
CALL fftx_c2psi_k_tg( dfft, f_out, f_in, igk, npw, dbnd )
ENDIF
!
!$acc host_data use_device(f_out)
CALL invfft( 'tgWave', f_out, dfft )
!$acc end host_data
!
!$acc end data
!
RETURN
!
END SUBROUTINE tgwave_g2r
!
!
!----------------------------------------------------------------------
SUBROUTINE tgwave_r2g( f_in, f_out, dfft, n, igk )
!--------------------------------------------------------------------
!! Wave function FFT from R to G-space. Task-group version.
!
USE fft_helper_subroutines, ONLY: fftx_psi2c_gamma_tg, fftx_psi2c_k_tg
!
IMPLICIT NONE
!
TYPE(fft_type_descriptor), INTENT(IN) :: dfft
!! FFT descriptor
COMPLEX(DP) :: f_in(:)
!! input: wave in g-space - task group chunk
COMPLEX(DP), INTENT(OUT) :: f_out(:,:)
!! output: wave in r-space - task group chunk
INTEGER, INTENT(IN) :: n
!! true dimension of f_out
INTEGER, OPTIONAL, INTENT(IN) :: igk(:)
!! index of G corresponding to a given index of k+G
!
! ... local variables
INTEGER :: dbnd
!
dbnd = SIZE(f_out(1,:))
!
!$acc data present_or_copyin(f_in) present_or_copyout(f_out)
!
!$acc host_data use_device(f_in)
CALL fwfft( 'tgWave', f_in, dfft )
!$acc end host_data
!
IF (gamma_only) THEN
CALL fftx_psi2c_gamma_tg( dfft, f_in, f_out, n, dbnd )
ELSE
CALL fftx_psi2c_k_tg( dfft, f_in, f_out, igk, n, dbnd )
ENDIF
!
!$acc end data
!
RETURN
!
END SUBROUTINE tgwave_r2g
!
!
END MODULE fft_wave