src/gromacs/mdlib/gmx_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 #ifdef GMX_LIB_MPI
  27 #include <mpi.h>
  28 #endif
  29 #ifdef GMX_THREAD_MPI
  30 #include "tmpi.h"
  31 #endif
  32
  33 #include "smalloc.h"
  34 #include "gmx_parallel_3dfft.h"
  35 #include "gmx_fft.h"
  36 #include "gmxcomplex.h"
  37 #include "gmx_fatal.h"
  38
  39 #include "fft5d.h"
  40
  41 struct gmx_parallel_3dfft  {
  42     fft5d_plan p1, p2;
  43 };
  44
  45 int
  46 gmx_parallel_3dfft_init   (gmx_parallel_3dfft_t     *    pfft_setup,
  47                            ivec                          ndata,
  48                            real     **                   real_data,
  49                            t_complex     **              complex_data,
  50                            MPI_Comm                      comm[2],
  51                            int     *                     slab2index_major,
  52                            int     *                     slab2index_minor,
  53                            gmx_bool                      bReproducible,
  54                            int                           nthreads)
  55 {
  56     int        rN      = ndata[2], M = ndata[1], K = ndata[0];
  57     int        flags   = FFT5D_REALCOMPLEX | FFT5D_ORDER_YZ; /* FFT5D_DEBUG */
  58     MPI_Comm   rcomm[] = {comm[1], comm[0]};
  59     int        Nb, Mb, Kb;                                   /* dimension for backtransform (in starting order) */
  60     t_complex *buf1, *buf2;                                  /*intermediate buffers - used internally.*/
  61
  62     snew(*pfft_setup, 1);
  63     if (bReproducible)
  64     {
  65         flags |= FFT5D_NOMEASURE;
  66     }
  67
  68     if (!(flags&FFT5D_ORDER_YZ))
  69     {
  70         Nb = M; Mb = K; Kb = rN;
  71     }
  72     else
  73     {
  74         Nb = K; Mb = rN; Kb = M;  /* currently always true because ORDER_YZ always set */
  75     }
  76
  77     (*pfft_setup)->p1 = fft5d_plan_3d(rN, M, K, rcomm, flags, (t_complex**)real_data, complex_data, &buf1, &buf2, nthreads);
  78
  79     (*pfft_setup)->p2 = fft5d_plan_3d(Nb, Mb, Kb, rcomm,
  80                                       (flags|FFT5D_BACKWARD|FFT5D_NOMALLOC)^FFT5D_ORDER_YZ, complex_data, (t_complex**)real_data, &buf1, &buf2, nthreads);
  81
  82     return (*pfft_setup)->p1 != 0 && (*pfft_setup)->p2 != 0;
  83 }
  84
  85
  86 static int
  87 fft5d_limits(fft5d_plan                p,
  88              ivec                      local_ndata,
  89              ivec                      local_offset,
  90              ivec                      local_size)
  91 {
  92     local_offset[2] = 0;
  93     local_offset[1] = p->oM[0];  /*=p->coor[0]*p->MG/p->P[0]; */
  94     local_offset[0] = p->oK[0];  /*=p->coor[1]*p->KG/p->P[1]; */
  95
  96     local_ndata[2] = p->rC[0];
  97     local_ndata[1] = p->pM[0];
  98     local_ndata[0] = p->pK[0];
  99
 100     if ((!(p->flags&FFT5D_BACKWARD)) && (p->flags&FFT5D_REALCOMPLEX))
 101     {
 102         //C is length in multiples of complex local_size in multiples of real
 103         local_size[2] = p->C[0]*2;
 104     }
 105     else
 106     {
 107         local_size[2] = p->C[0];
 108     }
 109     local_size[1] = p->pM[0];
 110     local_size[0] = p->pK[0];
 111     return 0;
 112 }
 113
 114 int
 115 gmx_parallel_3dfft_real_limits(gmx_parallel_3dfft_t      pfft_setup,
 116                                ivec                      local_ndata,
 117                                ivec                      local_offset,
 118                                ivec                      local_size)
 119 {
 120     return fft5d_limits(pfft_setup->p1, local_ndata, local_offset, local_size);
 121 }
 122
 123 static void reorder_ivec_yzx(ivec v)
 124 {
 125     real tmp;
 126
 127     tmp   = v[0];
 128     v[XX] = v[2];
 129     v[ZZ] = v[1];
 130     v[YY] = tmp;
 131 }
 132
 133 int
 134 gmx_parallel_3dfft_complex_limits(gmx_parallel_3dfft_t      pfft_setup,
 135                                   ivec                      complex_order,
 136                                   ivec                      local_ndata,
 137                                   ivec                      local_offset,
 138                                   ivec                      local_size)
 139 {
 140     int ret;
 141
 142     /* For now everything is in-order, but prepare to save communication by avoiding transposes */
 143     complex_order[0] = 0;
 144     complex_order[1] = 1;
 145     complex_order[2] = 2;
 146
 147     ret = fft5d_limits(pfft_setup->p2, local_ndata, local_offset, local_size);
 148
 149     reorder_ivec_yzx(local_ndata);
 150     reorder_ivec_yzx(local_offset);
 151     reorder_ivec_yzx(local_size);
 152
 153     return ret;
 154 }
 155
 156
 157 int
 158 gmx_parallel_3dfft_execute(gmx_parallel_3dfft_t    pfft_setup,
 159                            enum gmx_fft_direction  dir,
 160                            void *                  in_data,
 161                            void *                  out_data,
 162                            int                     thread,
 163                            gmx_wallcycle_t         wcycle)
 164 {
 165     if ((!(pfft_setup->p1->flags&FFT5D_REALCOMPLEX)) ^ (dir == GMX_FFT_FORWARD || dir == GMX_FFT_BACKWARD))
 166     {
 167         gmx_fatal(FARGS, "Invalid transform. Plan and execution don't match regarding reel/complex");
 168     }
 169     if (dir == GMX_FFT_FORWARD || dir == GMX_FFT_REAL_TO_COMPLEX)
 170     {
 171         fft5d_execute(pfft_setup->p1, thread, wcycle);
 172     }
 173     else
 174     {
 175         fft5d_execute(pfft_setup->p2, thread, wcycle);
 176     }
 177     return 0;
 178 }
 179
 180 int
 181 gmx_parallel_3dfft_destroy(gmx_parallel_3dfft_t    pfft_setup)
 182 {
 183     if (pfft_setup)
 184     {
 185         fft5d_destroy(pfft_setup->p2);
 186         fft5d_destroy(pfft_setup->p1);
 187         sfree(pfft_setup);
 188     }
 189     return 0;
 190 }