variable grid_type (internal to the FFTXlib routines, never referenced outside)
renamed fft_kind to better reflect its meaning.
unused file task_groups.f90 removed
three types of calls are possibles : 'Rho', 'Wave', 'tgWave'
In order to enable an fft-type for a given grid the corresponding clock_labels must be set.
One gives a name to desc%rho_clock_lable for 'Rho' type fft and a name to
desc%wave_clock_lable for 'Wave' and 'tgWave' types. Whether tg is
possible depends of the already defined value of desc%have_task_groups variable (mispell to be corrected soon).
definining
dffts%rho_clock_label='ffts', dffts%wave_clock_label='fftw',
dfftp%rho_clock_label='fft', dfftt%rho_clock_label='fftc' and
dfftt%wave_clock_label='fftcw'
and changing
'Dense'->'Rho', 'Smooth'->'Rho', 'Custom'->'Rho', 'CustomWave'->'Wave'
the same clock names and the same overall behavior as with the old interface is obtained.
In real space processors are organized in a 2D pattern.
Each processor owns data from a sub-set of Z-planes and a sub-set of Y-planes.
In reciprocal space each processor owns Z-columns that belong to a sub set of
X-values. This allows to split the processors in two sets for communication
in the YZ and XY planes.
In alternative, if the situation allows for it, a task group paralelization is used
(with ntg=nyfft) where complete XY planes of ntg wavefunctions are collected and Fourier
trasnformed in G space by different task-groups. This is preferable to the Z-proc + Y-proc
paralleization if task group can be used because a smaller number of larger ammounts of
data are transferred. Hence three types of fft are implemented:
!
!! ... isgn = +-1 : parallel 3d fft for rho and for the potential
!
!! ... isgn = +-2 : parallel 3d fft for wavefunctions
!
!! ... isgn = +-3 : parallel 3d fft for wavefunctions with task group
!
!! ... 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_yz)
!! ... fft along y using pencils (cft_1y)
!! ... transpose across nodes (fft_scatter_xy)
!! ... fft along x using pencils (cft_1x)
!
!! ... isgn = - : R-space to G-space, output = \int_R f(R)exp(-iG*R)/Omega
!! ... fft along x using pencils (cft_1x)
!! ... transpose across nodes (fft_scatter_xy)
!! ... fft along y using pencils (cft_1y)
!! ... transpose across nodes (fft_scatter_yz)
!! ... fft along z using pencils (cft_1z)
!
! If task_group_fft_is_active the FFT acts on a number of wfcs equal to
! dfft%nproc2, the number of Y-sections in which a plane is divided.
! Data are reshuffled by the fft_scatter_tg routine so that each of the
! dfft%nproc2 subgroups (made by dfft%nproc3 procs) deals with whole planes
! of a single wavefunciton.
!
fft_type module heavily modified, a number of variables renamed with more intuitive names
(at least to me), a number of more variables introduced for the Y-proc parallelization.
Task_group module made void. task_group management is now reduced to the logical component
fft_desc%have_task_groups of fft_type_descriptor type variable fft_desc.
In term of interfaces, the 'easy' calling sequences are
SUBROUTINE invfft/fwfft( grid_type, f, dfft, howmany )
!! where:
!!
!! **grid_type = 'Dense'** :
!! inverse/direct fourier transform of potentials and charge density f
!! on the dense grid (dfftp). On output, f is overwritten
!!
!! **grid_type = 'Smooth'** :
!! inverse/direct fourier transform of potentials and charge density f
!! on the smooth grid (dffts). On output, f is overwritten
!!
!! **grid_type = 'Wave'** :
!! inverse/direct fourier transform of wave functions f
!! on the smooth grid (dffts). On output, f is overwritten
!!
!! **grid_type = 'tgWave'** :
!! inverse/direct fourier transform of wave functions f with task group
!! on the smooth grid (dffts). On output, f is overwritten
!!
!! **grid_type = 'Custom'** :
!! inverse/direct fourier transform of potentials and charge density f
!! on a custom grid (dfft_exx). On output, f is overwritten
!!
!! **grid_type = 'CustomWave'** :
!! inverse/direct fourier transform of wave functions f
!! on a custom grid (dfft_exx). On output, f is overwritten
!!
!! **dfft = FFT descriptor**, IMPORTANT NOTICE: grid is specified only by dfft.
!! No check is performed on the correspondence between dfft and grid_type.
!! grid_type is now used only to distinguish cases 'Wave' / 'CustomWave'
!! from all other cases
Many more files modified.
git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@13676 c92efa57-630b-4861-b058-cf58834340f0
1) routines fwfft and invfft moved out of file fft_interfaces.f90 into new
file fft_fwinv.f90. Prevents massive recompilation if something changes
in the FFT routines.
2) machine-dependent fft_scalar.*.f90 are now modules with different names,
conditionally included into fft_scalar with a USE, no longer an #include.
Avoids trouble with dependencies, allow simplification of makedeps.sh.
All changes should be harmless, but I have tested only FFTW, FFTW3, DFTI.
Please let me know if there is any problem
git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@13185 c92efa57-630b-4861-b058-cf58834340f0
Paolo Giannozzi