Line data    Source code

       1              : !--------------------------------------------------------------------------------------------------!
       2              : !   CP2K: A general program to perform molecular dynamics simulations                              !
       3              : !   Copyright 2000-2025 CP2K developers group <https://cp2k.org>                                   !
       4              : !                                                                                                  !
       5              : !   SPDX-License-Identifier: GPL-2.0-or-later                                                      !
       6              : !--------------------------------------------------------------------------------------------------!
       7              : 
       8              : ! **************************************************************************************************
       9              : !> \brief Type to store data about a (1D or 3D) FFT, including FFTW plan
      10              : !> \par History
      11              : !>      IAB 09-Jan-2009 : initial version
      12              : !>                        (c) The Numerical Algorithms Group (NAG) Ltd, 2009 on behalf of the HECToR project
      13              : !>      IAB 09-Oct-2009 : Added additional fields needed when using OpenMP
      14              : !>                        (c) The Numerical Algorithms Group (NAG) Ltd, 2009 on behalf of the HECToR project
      15              : !> \author JGH
      16              : ! **************************************************************************************************
      17              : 
      18              : MODULE fft_plan
      19              :    USE ISO_C_BINDING,                   ONLY: C_NULL_PTR,&
      20              :                                               C_PTR
      21              : 
      22              :    IMPLICIT NONE
      23              :    PRIVATE
      24              : 
      25              :    PUBLIC :: fft_plan_type
      26              : 
      27              :    TYPE fft_plan_type
      28              : 
      29              :       INTEGER                             :: fft_type = -1
      30              :       INTEGER                             :: fsign = 0
      31              :       LOGICAL                             :: trans = .FALSE., fft_in_place = .FALSE., valid = .FALSE., separated_plans = .FALSE.
      32              :       INTEGER                             :: n = -1, m = -1
      33              :       INTEGER, DIMENSION(3)               :: n_3d = -1
      34              : 
      35              : !   Handle for the FFTW plan
      36              :       TYPE(C_PTR)                         :: fftw_plan = C_NULL_PTR
      37              : 
      38              : !   Plan for the remaining rows for 1D FFT when number of threads does not divide the number of rows exactly
      39              : !$    TYPE(C_PTR)                         :: alt_fftw_plan = C_NULL_PTR
      40              : !$    LOGICAL                             :: need_alt_plan = .FALSE.
      41              : !$    INTEGER                             :: num_threads_needed = -1, num_rows = -1, alt_num_rows = -1
      42              : 
      43              : !   Individual plans (used by hand-optimised 3D FFT)
      44              :       TYPE(C_PTR)                     :: fftw_plan_nx = C_NULL_PTR, fftw_plan_ny = C_NULL_PTR, fftw_plan_nz = C_NULL_PTR
      45              : !   Plans for the remaining rows (when the number of threads does not divide the number of rows exactly)
      46              :       TYPE(C_PTR)                     :: fftw_plan_nx_r = C_NULL_PTR, fftw_plan_ny_r = C_NULL_PTR, fftw_plan_nz_r = C_NULL_PTR
      47              : 
      48              :    END TYPE fft_plan_type
      49              : 
      50            0 : END MODULE fft_plan