src/gromacs/fft/parallel_3dfft.c

   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.
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; either version 2
  10  * of the License, or (at your option) any later version.
  11  *
  12  * To help us fund GROMACS development, we humbly ask that you cite
  13  * the research papers on the package. Check out http://www.gromacs.org
  14  *
  15  * And Hey:
  16  * Gnomes, ROck Monsters And Chili Sauce
  17  */
  18 #ifdef HAVE_CONFIG_H
  19 #include <config.h>
  20 #endif
  21
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <errno.h>
  25
  26 #include "gromacs/fft/parallel_3dfft.h"
  27 #include "gromacs/fft/fft.h"
  28 #include "gromacs/utility/gmxmpi.h"
  29
  30 #include "smalloc.h"
  31 #include "gmxcomplex.h"
  32 #include "gmx_fatal.h"
  33
  34 #include "fft5d.h"
  35
  36 struct gmx_parallel_3dfft  {
  37     fft5d_plan p1, p2;
  38 };
  39
  40 int
  41 gmx_parallel_3dfft_init   (gmx_parallel_3dfft_t     *    pfft_setup,
  42                            ivec                          ndata,
  43                            real     **                   real_data,
  44                            t_complex     **              complex_data,
  45                            MPI_Comm                      comm[2],
  46                            int     *                     slab2index_major,
  47                            int     *                     slab2index_minor,
  48                            gmx_bool                      bReproducible,
  49                            int                           nthreads)
  50 {
  51     int        rN      = ndata[2], M = ndata[1], K = ndata[0];
  52     int        flags   = FFT5D_REALCOMPLEX | FFT5D_ORDER_YZ; /* FFT5D_DEBUG */
  53     MPI_Comm   rcomm[] = {comm[1], comm[0]};
  54     int        Nb, Mb, Kb;                                   /* dimension for backtransform (in starting order) */
  55     t_complex *buf1, *buf2;                                  /*intermediate buffers - used internally.*/
  56
  57     snew(*pfft_setup, 1);
  58     if (bReproducible)
  59     {
  60         flags |= FFT5D_NOMEASURE;
  61     }
  62
  63     if (!(flags&FFT5D_ORDER_YZ))
  64     {
  65         Nb = M; Mb = K; Kb = rN;
  66     }
  67     else
  68     {
  69         Nb = K; Mb = rN; Kb = M;  /* currently always true because ORDER_YZ always set */
  70     }
  71
  72     (*pfft_setup)->p1 = fft5d_plan_3d(rN, M, K, rcomm, flags, (t_complex**)real_data, complex_data, &buf1, &buf2, nthreads);
  73
  74     (*pfft_setup)->p2 = fft5d_plan_3d(Nb, Mb, Kb, rcomm,
  75                                       (flags|FFT5D_BACKWARD|FFT5D_NOMALLOC)^FFT5D_ORDER_YZ, complex_data, (t_complex**)real_data, &buf1, &buf2, nthreads);
  76
  77     return (*pfft_setup)->p1 != 0 && (*pfft_setup)->p2 != 0;
  78 }
  79
  80
  81 static int
  82 fft5d_limits(fft5d_plan                p,
  83              ivec                      local_ndata,
  84              ivec                      local_offset,
  85              ivec                      local_size)
  86 {
  87     local_offset[2] = 0;
  88     local_offset[1] = p->oM[0];  /*=p->coor[0]*p->MG/p->P[0]; */
  89     local_offset[0] = p->oK[0];  /*=p->coor[1]*p->KG/p->P[1]; */
  90
  91     local_ndata[2] = p->rC[0];
  92     local_ndata[1] = p->pM[0];
  93     local_ndata[0] = p->pK[0];
  94
  95     if ((!(p->flags&FFT5D_BACKWARD)) && (p->flags&FFT5D_REALCOMPLEX))
  96     {
  97         //C is length in multiples of complex local_size in multiples of real
  98         local_size[2] = p->C[0]*2;
  99     }
 100     else
 101     {
 102         local_size[2] = p->C[0];
 103     }
 104     local_size[1] = p->pM[0];
 105     local_size[0] = p->pK[0];
 106     return 0;
 107 }
 108
 109 int
 110 gmx_parallel_3dfft_real_limits(gmx_parallel_3dfft_t      pfft_setup,
 111                                ivec                      local_ndata,
 112                                ivec                      local_offset,
 113                                ivec                      local_size)
 114 {
 115     return fft5d_limits(pfft_setup->p1, local_ndata, local_offset, local_size);
 116 }
 117
 118 static void reorder_ivec_yzx(ivec v)
 119 {
 120     real tmp;
 121
 122     tmp   = v[0];
 123     v[XX] = v[2];
 124     v[ZZ] = v[1];
 125     v[YY] = tmp;
 126 }
 127
 128 int
 129 gmx_parallel_3dfft_complex_limits(gmx_parallel_3dfft_t      pfft_setup,
 130                                   ivec                      complex_order,
 131                                   ivec                      local_ndata,
 132                                   ivec                      local_offset,
 133                                   ivec                      local_size)
 134 {
 135     int ret;
 136
 137     /* For now everything is in-order, but prepare to save communication by avoiding transposes */
 138     complex_order[0] = 0;
 139     complex_order[1] = 1;
 140     complex_order[2] = 2;
 141
 142     ret = fft5d_limits(pfft_setup->p2, local_ndata, local_offset, local_size);
 143
 144     reorder_ivec_yzx(local_ndata);
 145     reorder_ivec_yzx(local_offset);
 146     reorder_ivec_yzx(local_size);
 147
 148     return ret;
 149 }
 150
 151
 152 int
 153 gmx_parallel_3dfft_execute(gmx_parallel_3dfft_t    pfft_setup,
 154                            enum gmx_fft_direction  dir,
 155                            void *                  in_data,
 156                            void *                  out_data,
 157                            int                     thread,
 158                            gmx_wallcycle_t         wcycle)
 159 {
 160     if ((!(pfft_setup->p1->flags&FFT5D_REALCOMPLEX)) ^ (dir == GMX_FFT_FORWARD || dir == GMX_FFT_BACKWARD))
 161     {
 162         gmx_fatal(FARGS, "Invalid transform. Plan and execution don't match regarding reel/complex");
 163     }
 164     if (dir == GMX_FFT_FORWARD || dir == GMX_FFT_REAL_TO_COMPLEX)
 165     {
 166         fft5d_execute(pfft_setup->p1, thread, wcycle);
 167     }
 168     else
 169     {
 170         fft5d_execute(pfft_setup->p2, thread, wcycle);
 171     }
 172     return 0;
 173 }
 174
 175 int
 176 gmx_parallel_3dfft_destroy(gmx_parallel_3dfft_t    pfft_setup)
 177 {
 178     if (pfft_setup)
 179     {
 180         fft5d_destroy(pfft_setup->p2);
 181         fft5d_destroy(pfft_setup->p1);
 182         sfree(pfft_setup);
 183     }
 184     return 0;
 185 }