include/gmx_parallel_3dfft.h

   1 /* -*- mode: c; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; c-file-style: "stroustrup"; -*-
   2  *
   3  *
   4  * Gromacs                               Copyright (c) 1991-2005
   5  * David van der Spoel, Erik Lindahl, University of Groningen.
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   9  * as published by the Free Software Foundation; either version 2
  10  * of the License, or (at your option) any later version.
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  18
  19 #ifndef _gmx_parallel_3dfft_h_
  20 #define _gmx_parallel_3dfft_h_
  21
  22
  23 #include "types/simple.h"
  24 #include "types/commrec.h"
  25 #include "gmxcomplex.h"
  26 #include "gmx_fft.h"
  27
  28 typedef struct gmx_parallel_3dfft *
  29 gmx_parallel_3dfft_t;
  30
  31
  32
  33 /*! \brief Initialize parallel MPI-based 3D-FFT.
  34  *
  35  *  This routine performs real-to-complex and complex-to-real parallel 3D FFTs,
  36  *  but not complex-to-complex.
  37  *
  38  *  The routine is optimized for small-to-medium size FFTs used for PME and
  39  *  PPPM algorithms, and do allocate extra workspace whenever it might improve
  40  *  performance.
  41  *
  42  *  \param pfft_setup     Pointer to parallel 3dfft setup structure, previously
  43  *                        allocated or with automatic storage.
  44  *  \param ngridx         Global number of grid cells in the x direction. Must be
  45  *                        divisible by the number of nodes.
  46  *  \param ngridy         Global number of grid cells in the y direction. Must be
  47  *                        divisible by the number of nodes.
  48  *  \param ngridz         Global number of grid cells in the z direction.
  49  *  \param node2slab      Node id to slab index array, can be NULL.
  50  *  \param slab2grid_x    Slab index to grid_x array (nnodes+1), can be NULL.
  51  *  \param comm           MPI communicator, must have been initialized.
  52  *  \param bReproducible  Try to avoid FFT timing optimizations and other stuff
  53  *                        that could make results differ for two runs with
  54  *                        identical input (reproducibility for debugging).
  55  *
  56  *  \return 0 or a standard error code.
  57  */
  58 int
  59 gmx_parallel_3dfft_init   (gmx_parallel_3dfft_t *    pfft_setup,
  60                            ivec                      ndata,
  61                                                    real **                   real_data,
  62                                                    t_complex **              complex_data,
  63                            MPI_Comm                  comm[2],
  64                            int *                     slab2index_major,
  65                            int *                     slab2index_minor,
  66                            gmx_bool                      bReproducible);
  67
  68
  69
  70
  71
  72 /*! \brief Get direct space grid index limits
  73  */
  74 int
  75 gmx_parallel_3dfft_real_limits(gmx_parallel_3dfft_t      pfft_setup,
  76                                                            ivec                      local_ndata,
  77                                                            ivec                      local_offset,
  78                                                            ivec                      local_size);
  79
  80
  81 /*! \brief Get reciprocal space grid index limits
  82  */
  83 int
  84 gmx_parallel_3dfft_complex_limits(gmx_parallel_3dfft_t      pfft_setup,
  85                                   ivec                      complex_order,
  86                                                                   ivec                      local_ndata,
  87                                                                   ivec                      local_offset,
  88                                                                   ivec                      local_size);
  89
  90
  91 int
  92 gmx_parallel_3dfft_execute(gmx_parallel_3dfft_t    pfft_setup,
  93                                                    enum gmx_fft_direction  dir,
  94                                                    void *                  in_data,
  95                                                    void *                  out_data);
  96
  97
  98 /*! \brief Release all data in parallel fft setup
  99  *
 100  *  All temporary storage and FFT plans are released. The structure itself
 101  *  is not released, but the contents is invalid after this call.
 102  *
 103  *  \param pfft_setup Parallel 3dfft setup.
 104  *
 105  *  \return 0 or a standard error code.
 106  */
 107 int
 108 gmx_parallel_3dfft_destroy(gmx_parallel_3dfft_t    pfft_setup);
 109
 110
 111
 112
 113 #endif /* _gmx_parallel_3dfft_h_ */
 114