quantum-espresso/Modules/fft_parallel.f90

333 lines
9.4 KiB
Fortran

!
! Copyright (C) 2001-2009 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 .
!
!=---------------------------------------------------------------------==!
!
!
! Parallel 3D FFT high level Driver
! ( Charge density and Wave Functions )
!
! Written and maintained by Carlo Cavazzoni
! Last update Apr. 2009
!
!=---------------------------------------------------------------------==!
!
MODULE fft_parallel
!
IMPLICIT NONE
SAVE
!
CONTAINS
!
! General purpose driver, including Task groups parallelization
!
!----------------------------------------------------------------------------
SUBROUTINE tg_cft3s( f, dfft, isgn, use_task_groups )
!----------------------------------------------------------------------------
!
! ... isgn = +-1 : parallel 3d fft for rho and for the potential
! NOT IMPLEMENTED WITH TASK GROUPS
! ... isgn = +-2 : parallel 3d fft for wavefunctions
!
! ... isgn = + : G-space to R-space, output = \sum_G f(G)exp(+iG*R)
! ... fft along z using pencils (cft_1z)
! ... transpose across nodes (fft_scatter)
! ... and reorder
! ... fft along y (using planes) and x (cft_2xy)
! ... isgn = - : R-space to G-space, output = \int_R f(R)exp(-iG*R)/Omega
! ... fft along x and y(using planes) (cft_2xy)
! ... transpose across nodes (fft_scatter)
! ... and reorder
! ... fft along z using pencils (cft_1z)
!
! ... The array "planes" signals whether a fft is needed along y :
! ... planes(i)=0 : column f(i,*,*) empty , don't do fft along y
! ... planes(i)=1 : column f(i,*,*) filled, fft along y needed
! ... "empty" = no active components are present in f(i,*,*)
! ... after (isgn>0) or before (isgn<0) the fft on z direction
!
! ... Note that if isgn=+/-1 (fft on rho and pot.) all fft's are needed
! ... and all planes(i) are set to 1
!
! This driver is based on code written by Stefano de Gironcoli for PWSCF.
! Task Group added by Costas Bekas, Oct. 2005, adapted from the CPMD code
! (Alessandro Curioni) and revised by Carlo Cavazzoni 2007.
!
USE fft_scalar, ONLY : cft_1z, cft_2xy
USE fft_base, ONLY : fft_scatter
USE kinds, ONLY : DP
USE fft_types, ONLY : fft_dlay_descriptor
USE parallel_include
!
IMPLICIT NONE
!
COMPLEX(DP), INTENT(inout) :: f( : ) ! array containing data to be transformed
TYPE (fft_dlay_descriptor), INTENT(in) :: dfft
! descriptor of fft data layout
INTEGER, INTENT(in) :: isgn ! fft direction
LOGICAL, OPTIONAL, INTENT(in) :: use_task_groups
! specify if you want to use task groups parallelization
!
INTEGER :: me_p
INTEGER :: n1, n2, n3, nx1, nx2, nx3
COMPLEX(DP), ALLOCATABLE :: yf(:), aux (:)
INTEGER :: planes( dfft%nr1x )
LOGICAL :: use_tg
!
!
IF( present( use_task_groups ) ) THEN
use_tg = use_task_groups
ELSE
use_tg = .false.
ENDIF
!
IF( use_tg .and. .not. dfft%have_task_groups ) &
CALL errore( ' tg_cft3s ', ' call requiring task groups for a descriptor without task groups ', 1 )
!
n1 = dfft%nr1
n2 = dfft%nr2
n3 = dfft%nr3
nx1 = dfft%nr1x
nx2 = dfft%nr2x
nx3 = dfft%nr3x
!
IF( use_tg ) THEN
ALLOCATE( aux( dfft%nogrp * dfft%tg_nnr ) )
ALLOCATE( YF ( dfft%nogrp * dfft%tg_nnr ) )
ELSE
ALLOCATE( aux( dfft%tg_nnr ) )
ENDIF
!
me_p = dfft%mype + 1
!
IF ( isgn > 0 ) THEN
!
IF ( isgn /= 2 ) THEN
!
IF( use_tg ) &
CALL errore( ' tg_cft3s ', ' task groups on large mesh not implemented ', 1 )
!
CALL cft_1z( f, dfft%nsp( me_p ), n3, nx3, isgn, aux )
!
planes = dfft%iplp
!
ELSE
!
CALL pack_group_sticks()
!
IF( use_tg ) THEN
CALL cft_1z( yf, dfft%tg_nsw( me_p ), n3, nx3, isgn, aux )
ELSE
CALL cft_1z( f, dfft%nsw( me_p ), n3, nx3, isgn, aux )
ENDIF
!
planes = dfft%iplw
!
ENDIF
!
CALL fw_scatter( isgn ) ! forwart scatter from stick to planes
!
IF( use_tg ) THEN
CALL cft_2xy( f, dfft%tg_npp( me_p ), n1, n2, nx1, nx2, isgn, planes )
ELSE
CALL cft_2xy( f, dfft%npp( me_p ), n1, n2, nx1, nx2, isgn, planes )
ENDIF
!
ELSE
!
IF ( isgn /= -2 ) THEN
!
IF( use_tg ) &
CALL errore( ' tg_cft3s ', ' task groups on large mesh not implemented ', 1 )
!
planes = dfft%iplp
!
ELSE
!
planes = dfft%iplw
!
ENDIF
IF( use_tg ) THEN
CALL cft_2xy( f, dfft%tg_npp( me_p ), n1, n2, nx1, nx2, isgn, planes )
ELSE
CALL cft_2xy( f, dfft%npp( me_p ), n1, n2, nx1, nx2, isgn, planes)
ENDIF
!
CALL bw_scatter( isgn )
!
IF ( isgn /= -2 ) THEN
!
CALL cft_1z( aux, dfft%nsp( me_p ), n3, nx3, isgn, f )
!
ELSE
!
IF( use_tg ) THEN
CALL cft_1z( aux, dfft%tg_nsw( me_p ), n3, nx3, isgn, yf )
ELSE
CALL cft_1z( aux, dfft%nsw( me_p ), n3, nx3, isgn, f )
ENDIF
!
CALL unpack_group_sticks()
!
ENDIF
!
ENDIF
!
DEALLOCATE( aux )
!
IF( use_tg ) THEN
DEALLOCATE( yf )
ENDIF
!
RETURN
!
CONTAINS
!
SUBROUTINE pack_group_sticks()
INTEGER :: ierr
!
IF( .not. use_tg ) RETURN
!
IF( dfft%tg_rdsp(dfft%nogrp) + dfft%tg_rcv(dfft%nogrp) > size( yf ) ) THEN
CALL errore( 'pack_group_sticks' , ' inconsistent size ', 1 )
ENDIF
IF( dfft%tg_psdsp(dfft%nogrp) + dfft%tg_snd(dfft%nogrp) > size( f ) ) THEN
CALL errore( 'pack_group_sticks', ' inconsistent size ', 2 )
ENDIF
CALL start_clock( 'ALLTOALL' )
!
! Collect all the sticks of the different states,
! in "yf" processors will have all the sticks of the OGRP
#if defined __MPI
CALL MPI_ALLTOALLV( f(1), dfft%tg_snd, dfft%tg_psdsp, MPI_DOUBLE_COMPLEX, yf(1), dfft%tg_rcv, &
& dfft%tg_rdsp, MPI_DOUBLE_COMPLEX, dfft%ogrp_comm, IERR)
IF( ierr /= 0 ) THEN
CALL errore( 'pack_group_sticks', ' alltoall error 1 ', abs(ierr) )
ENDIF
#endif
CALL stop_clock( 'ALLTOALL' )
!
!YF Contains all ( ~ NOGRP*dfft%nsw(me) ) Z-sticks
!
RETURN
END SUBROUTINE pack_group_sticks
!
SUBROUTINE unpack_group_sticks()
!
! Bring pencils back to their original distribution
!
INTEGER :: ierr
!
IF( .not. use_tg ) RETURN
!
IF( dfft%tg_usdsp(dfft%nogrp) + dfft%tg_snd(dfft%nogrp) > size( f ) ) THEN
CALL errore( 'unpack_group_sticks', ' inconsistent size ', 3 )
ENDIF
IF( dfft%tg_rdsp(dfft%nogrp) + dfft%tg_rcv(dfft%nogrp) > size( yf ) ) THEN
CALL errore( 'unpack_group_sticks', ' inconsistent size ', 4 )
ENDIF
CALL start_clock( 'ALLTOALL' )
#if defined __MPI
CALL MPI_Alltoallv( yf(1), &
dfft%tg_rcv, dfft%tg_rdsp, MPI_DOUBLE_COMPLEX, f(1), &
dfft%tg_snd, dfft%tg_usdsp, MPI_DOUBLE_COMPLEX, dfft%ogrp_comm, IERR)
IF( ierr /= 0 ) THEN
CALL errore( 'unpack_group_sticks', ' alltoall error 2 ', abs(ierr) )
ENDIF
#endif
CALL stop_clock( 'ALLTOALL' )
RETURN
END SUBROUTINE unpack_group_sticks
!
SUBROUTINE fw_scatter( iopt )
!Transpose data for the 2-D FFT on the x-y plane
!
!NOGRP*dfft%nnr: The length of aux and f
!nr3x: The length of each Z-stick
!aux: input - output
!f: working space
!isgn: type of scatter
!dfft%nsw(me) holds the number of Z-sticks proc. me has.
!dfft%npp: number of planes per processor
!
!
USE fft_base, ONLY: fft_scatter
!
INTEGER, INTENT(in) :: iopt
!
IF( iopt == 2 ) THEN
!
IF( use_tg ) THEN
!
CALL fft_scatter( dfft, aux, nx3, dfft%nogrp*dfft%tg_nnr, f, dfft%tg_nsw, dfft%tg_npp, iopt, use_tg )
!
ELSE
!
CALL fft_scatter( dfft, aux, nx3, dfft%nnr, f, dfft%nsw, dfft%npp, iopt )
!
ENDIF
!
ELSEIF( iopt == 1 ) THEN
!
CALL fft_scatter( dfft, aux, nx3, dfft%nnr, f, dfft%nsp, dfft%npp, iopt )
!
ENDIF
!
RETURN
END SUBROUTINE fw_scatter
!
SUBROUTINE bw_scatter( iopt )
!
USE fft_base, ONLY: fft_scatter
!
INTEGER, INTENT(in) :: iopt
!
IF( iopt == -2 ) THEN
!
IF( use_tg ) THEN
!
CALL fft_scatter( dfft, aux, nx3, dfft%nogrp*dfft%tg_nnr, f, dfft%tg_nsw, dfft%tg_npp, iopt, use_tg )
!
ELSE
!
CALL fft_scatter( dfft, aux, nx3, dfft%nnr, f, dfft%nsw, dfft%npp, iopt )
!
ENDIF
!
ELSEIF( iopt == -1 ) THEN
!
CALL fft_scatter( dfft, aux, nx3, dfft%nnr, f, dfft%nsp, dfft%npp, iopt )
!
ENDIF
!
RETURN
END SUBROUTINE bw_scatter
!
END SUBROUTINE tg_cft3s
!
END MODULE fft_parallel