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                            gmx_bool                      bReproducible,
  47                            int                           nthreads)
  48 {
  49     int        rN      = ndata[2], M = ndata[1], K = ndata[0];
  50     int        flags   = FFT5D_REALCOMPLEX | FFT5D_ORDER_YZ; /* FFT5D_DEBUG */
  51     MPI_Comm   rcomm[] = {comm[1], comm[0]};
  52     int        Nb, Mb, Kb;                                   /* dimension for backtransform (in starting order) */
  53     t_complex *buf1, *buf2;                                  /*intermediate buffers - used internally.*/
  54
  55     snew(*pfft_setup, 1);
  56     if (bReproducible)
  57     {
  58         flags |= FFT5D_NOMEASURE;
  59     }
  60
  61     if (!(flags&FFT5D_ORDER_YZ))
  62     {
  63         Nb = M; Mb = K; Kb = rN;
  64     }
  65     else
  66     {
  67         Nb = K; Mb = rN; Kb = M;  /* currently always true because ORDER_YZ always set */
  68     }
  69
  70     (*pfft_setup)->p1 = fft5d_plan_3d(rN, M, K, rcomm, flags, (t_complex**)real_data, complex_data, &buf1, &buf2, nthreads);
  71
  72     (*pfft_setup)->p2 = fft5d_plan_3d(Nb, Mb, Kb, rcomm,
  73                                       (flags|FFT5D_BACKWARD|FFT5D_NOMALLOC)^FFT5D_ORDER_YZ, complex_data, (t_complex**)real_data, &buf1, &buf2, nthreads);
  74
  75     return (*pfft_setup)->p1 != 0 && (*pfft_setup)->p2 != 0;
  76 }
  77
  78
  79 static int
  80 fft5d_limits(fft5d_plan                p,
  81              ivec                      local_ndata,
  82              ivec                      local_offset,
  83              ivec                      local_size)
  84 {
  85     local_offset[2] = 0;
  86     local_offset[1] = p->oM[0];  /*=p->coor[0]*p->MG/p->P[0]; */
  87     local_offset[0] = p->oK[0];  /*=p->coor[1]*p->KG/p->P[1]; */
  88
  89     local_ndata[2] = p->rC[0];
  90     local_ndata[1] = p->pM[0];
  91     local_ndata[0] = p->pK[0];
  92
  93     if ((!(p->flags&FFT5D_BACKWARD)) && (p->flags&FFT5D_REALCOMPLEX))
  94     {
  95         //C is length in multiples of complex local_size in multiples of real
  96         local_size[2] = p->C[0]*2;
  97     }
  98     else
  99     {
 100         local_size[2] = p->C[0];
 101     }
 102     local_size[1] = p->pM[0];
 103     local_size[0] = p->pK[0];
 104     return 0;
 105 }
 106
 107 int
 108 gmx_parallel_3dfft_real_limits(gmx_parallel_3dfft_t      pfft_setup,
 109                                ivec                      local_ndata,
 110                                ivec                      local_offset,
 111                                ivec                      local_size)
 112 {
 113     return fft5d_limits(pfft_setup->p1, local_ndata, local_offset, local_size);
 114 }
 115
 116 static void reorder_ivec_yzx(ivec v)
 117 {
 118     real tmp;
 119
 120     tmp   = v[0];
 121     v[XX] = v[2];
 122     v[ZZ] = v[1];
 123     v[YY] = tmp;
 124 }
 125
 126 int
 127 gmx_parallel_3dfft_complex_limits(gmx_parallel_3dfft_t      pfft_setup,
 128                                   ivec                      complex_order,
 129                                   ivec                      local_ndata,
 130                                   ivec                      local_offset,
 131                                   ivec                      local_size)
 132 {
 133     int ret;
 134
 135     /* For now everything is in-order, but prepare to save communication by avoiding transposes */
 136     complex_order[0] = 0;
 137     complex_order[1] = 1;
 138     complex_order[2] = 2;
 139
 140     ret = fft5d_limits(pfft_setup->p2, local_ndata, local_offset, local_size);
 141
 142     reorder_ivec_yzx(local_ndata);
 143     reorder_ivec_yzx(local_offset);
 144     reorder_ivec_yzx(local_size);
 145
 146     return ret;
 147 }
 148
 149
 150 int
 151 gmx_parallel_3dfft_execute(gmx_parallel_3dfft_t    pfft_setup,
 152                            enum gmx_fft_direction  dir,
 153                            int                     thread,
 154                            gmx_wallcycle_t         wcycle)
 155 {
 156     if ((!(pfft_setup->p1->flags&FFT5D_REALCOMPLEX)) ^ (dir == GMX_FFT_FORWARD || dir == GMX_FFT_BACKWARD))
 157     {
 158         gmx_fatal(FARGS, "Invalid transform. Plan and execution don't match regarding reel/complex");
 159     }
 160     if (dir == GMX_FFT_FORWARD || dir == GMX_FFT_REAL_TO_COMPLEX)
 161     {
 162         fft5d_execute(pfft_setup->p1, thread, wcycle);
 163     }
 164     else
 165     {
 166         fft5d_execute(pfft_setup->p2, thread, wcycle);
 167     }
 168     return 0;
 169 }
 170
 171 int
 172 gmx_parallel_3dfft_destroy(gmx_parallel_3dfft_t    pfft_setup)
 173 {
 174     if (pfft_setup)
 175     {
 176         fft5d_destroy(pfft_setup->p2);
 177         fft5d_destroy(pfft_setup->p1);
 178         sfree(pfft_setup);
 179     }
 180     return 0;
 181 }