libgfortran/generated/matmul_r4.c

   1 /* Implementation of the MATMUL intrinsic
   2    Copyright 2002 Free Software Foundation, Inc.
   3    Contributed by Paul Brook <paul@nowt.org>
   4
   5 This file is part of the GNU Fortran 95 runtime library (libgfortran).
   6
   7 Libgfortran is free software; you can redistribute it and/or
   8 modify it under the terms of the GNU Lesser General Public
   9 License as published by the Free Software Foundation; either
  10 version 2.1 of the License, or (at your option) any later version.
  11
  12 Libgfortran is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU Lesser General Public License for more details.
  16
  17 You should have received a copy of the GNU Lesser General Public
  18 License along with libgfor; see the file COPYING.LIB.  If not,
  19 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22 #include "config.h"
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <assert.h>
  26 #include "libgfortran.h"
  27
  28 /* This is a C version of the following fortran pseudo-code. The key
  29    point is the loop order -- we access all arrays column-first, which
  30    improves the performance enough to boost galgel spec score by 50%.
  31
  32    DIMENSION A(M,COUNT), B(COUNT,N), C(M,N)
  33    C = 0
  34    DO J=1,N
  35      DO K=1,COUNT
  36        DO I=1,M
  37          C(I,J) = C(I,J)+A(I,K)*B(K,J)
  38 */
  39
  40 extern void matmul_r4 (gfc_array_r4 * retarray, gfc_array_r4 * a, gfc_array_r4 * b);
  41 export_proto(matmul_r4);
  42
  43 void
  44 matmul_r4 (gfc_array_r4 * retarray, gfc_array_r4 * a, gfc_array_r4 * b)
  45 {
  46   GFC_REAL_4 *abase;
  47   GFC_REAL_4 *bbase;
  48   GFC_REAL_4 *dest;
  49
  50   index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
  51   index_type x, y, n, count, xcount, ycount;
  52
  53   assert (GFC_DESCRIPTOR_RANK (a) == 2
  54           || GFC_DESCRIPTOR_RANK (b) == 2);
  55
  56 /* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
  57
  58    Either A or B (but not both) can be rank 1:
  59
  60    o One-dimensional argument A is implicitly treated as a row matrix
  61      dimensioned [1,count], so xcount=1.
  62
  63    o One-dimensional argument B is implicitly treated as a column matrix
  64      dimensioned [count, 1], so ycount=1.
  65   */
  66
  67   if (retarray->data == NULL)
  68     {
  69       if (GFC_DESCRIPTOR_RANK (a) == 1)
  70         {
  71           retarray->dim[0].lbound = 0;
  72           retarray->dim[0].ubound = b->dim[1].ubound - b->dim[1].lbound;
  73           retarray->dim[0].stride = 1;
  74         }
  75       else if (GFC_DESCRIPTOR_RANK (b) == 1)
  76         {
  77           retarray->dim[0].lbound = 0;
  78           retarray->dim[0].ubound = a->dim[0].ubound - a->dim[0].lbound;
  79           retarray->dim[0].stride = 1;
  80         }
  81       else
  82         {
  83           retarray->dim[0].lbound = 0;
  84           retarray->dim[0].ubound = a->dim[0].ubound - a->dim[0].lbound;
  85           retarray->dim[0].stride = 1;
  86
  87           retarray->dim[1].lbound = 0;
  88           retarray->dim[1].ubound = b->dim[1].ubound - b->dim[1].lbound;
  89           retarray->dim[1].stride = retarray->dim[0].ubound+1;
  90         }
  91
  92       retarray->data
  93         = internal_malloc_size (sizeof (GFC_REAL_4) * size0 (retarray));
  94       retarray->base = 0;
  95     }
  96
  97   abase = a->data;
  98   bbase = b->data;
  99   dest = retarray->data;
 100
 101   if (retarray->dim[0].stride == 0)
 102     retarray->dim[0].stride = 1;
 103   if (a->dim[0].stride == 0)
 104     a->dim[0].stride = 1;
 105   if (b->dim[0].stride == 0)
 106     b->dim[0].stride = 1;
 107
 108
 109   if (GFC_DESCRIPTOR_RANK (retarray) == 1)
 110     {
 111       /* One-dimensional result may be addressed in the code below
 112          either as a row or a column matrix. We want both cases to
 113          work. */
 114       rxstride = rystride = retarray->dim[0].stride;
 115     }
 116   else
 117     {
 118       rxstride = retarray->dim[0].stride;
 119       rystride = retarray->dim[1].stride;
 120     }
 121
 122
 123   if (GFC_DESCRIPTOR_RANK (a) == 1)
 124     {
 125       /* Treat it as a a row matrix A[1,count]. */
 126       axstride = a->dim[0].stride;
 127       aystride = 1;
 128
 129       xcount = 1;
 130       count = a->dim[0].ubound + 1 - a->dim[0].lbound;
 131     }
 132   else
 133     {
 134       axstride = a->dim[0].stride;
 135       aystride = a->dim[1].stride;
 136
 137       count = a->dim[1].ubound + 1 - a->dim[1].lbound;
 138       xcount = a->dim[0].ubound + 1 - a->dim[0].lbound;
 139     }
 140
 141   assert(count == b->dim[0].ubound + 1 - b->dim[0].lbound);
 142
 143   if (GFC_DESCRIPTOR_RANK (b) == 1)
 144     {
 145       /* Treat it as a column matrix B[count,1] */
 146       bxstride = b->dim[0].stride;
 147
 148       /* bystride should never be used for 1-dimensional b.
 149          in case it is we want it to cause a segfault, rather than
 150          an incorrect result. */
 151       bystride = 0xDEADBEEF;
 152       ycount = 1;
 153     }
 154   else
 155     {
 156       bxstride = b->dim[0].stride;
 157       bystride = b->dim[1].stride;
 158       ycount = b->dim[1].ubound + 1 - b->dim[1].lbound;
 159     }
 160
 161   assert (a->base == 0);
 162   assert (b->base == 0);
 163   assert (retarray->base == 0);
 164
 165   abase = a->data;
 166   bbase = b->data;
 167   dest = retarray->data;
 168
 169   if (rxstride == 1 && axstride == 1 && bxstride == 1)
 170     {
 171       GFC_REAL_4 *bbase_y;
 172       GFC_REAL_4 *dest_y;
 173       GFC_REAL_4 *abase_n;
 174       GFC_REAL_4 bbase_yn;
 175
 176       memset (dest, 0, (sizeof (GFC_REAL_4) * size0(retarray)));
 177
 178       for (y = 0; y < ycount; y++)
 179         {
 180           bbase_y = bbase + y*bystride;
 181           dest_y = dest + y*rystride;
 182           for (n = 0; n < count; n++)
 183             {
 184               abase_n = abase + n*aystride;
 185               bbase_yn = bbase_y[n];
 186               for (x = 0; x < xcount; x++)
 187                 {
 188                   dest_y[x] += abase_n[x] * bbase_yn;
 189                 }
 190             }
 191         }
 192     }
 193   else
 194     {
 195       for (y = 0; y < ycount; y++)
 196         for (x = 0; x < xcount; x++)
 197           dest[x*rxstride + y*rystride] = (GFC_REAL_4)0;
 198
 199       for (y = 0; y < ycount; y++)
 200         for (n = 0; n < count; n++)
 201           for (x = 0; x < xcount; x++)
 202             /* dest[x,y] += a[x,n] * b[n,y] */
 203             dest[x*rxstride + y*rystride] += abase[x*axstride + n*aystride] * bbase[n*bxstride + y*bystride];
 204     }
 205 }