libgfortran/generated/matmul_r8.c

   1 /* Implementation of the MATMUL intrinsic
   2    Copyright 2002, 2005 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 General Public
   9 License as published by the Free Software Foundation; either
  10 version 2 of the License, or (at your option) any later version.
  11
  12 In addition to the permissions in the GNU General Public License, the
  13 Free Software Foundation gives you unlimited permission to link the
  14 compiled version of this file into combinations with other programs,
  15 and to distribute those combinations without any restriction coming
  16 from the use of this file.  (The General Public License restrictions
  17 do apply in other respects; for example, they cover modification of
  18 the file, and distribution when not linked into a combine
  19 executable.)
  20
  21 Libgfortran is distributed in the hope that it will be useful,
  22 but WITHOUT ANY WARRANTY; without even the implied warranty of
  23 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24 GNU General Public License for more details.
  25
  26 You should have received a copy of the GNU General Public
  27 License along with libgfortran; see the file COPYING.  If not,
  28 write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  29 Boston, MA 02110-1301, USA.  */
  30
  31 #include "config.h"
  32 #include <stdlib.h>
  33 #include <string.h>
  34 #include <assert.h>
  35 #include "libgfortran.h"
  36
  37 /* This is a C version of the following fortran pseudo-code. The key
  38    point is the loop order -- we access all arrays column-first, which
  39    improves the performance enough to boost galgel spec score by 50%.
  40
  41    DIMENSION A(M,COUNT), B(COUNT,N), C(M,N)
  42    C = 0
  43    DO J=1,N
  44      DO K=1,COUNT
  45        DO I=1,M
  46          C(I,J) = C(I,J)+A(I,K)*B(K,J)
  47 */
  48
  49 extern void matmul_r8 (gfc_array_r8 * retarray, gfc_array_r8 * a, gfc_array_r8 * b);
  50 export_proto(matmul_r8);
  51
  52 void
  53 matmul_r8 (gfc_array_r8 * retarray, gfc_array_r8 * a, gfc_array_r8 * b)
  54 {
  55   GFC_REAL_8 *abase;
  56   GFC_REAL_8 *bbase;
  57   GFC_REAL_8 *dest;
  58
  59   index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
  60   index_type x, y, n, count, xcount, ycount;
  61
  62   assert (GFC_DESCRIPTOR_RANK (a) == 2
  63           || GFC_DESCRIPTOR_RANK (b) == 2);
  64
  65 /* C[xcount,ycount] = A[xcount, count] * B[count,ycount]
  66
  67    Either A or B (but not both) can be rank 1:
  68
  69    o One-dimensional argument A is implicitly treated as a row matrix
  70      dimensioned [1,count], so xcount=1.
  71
  72    o One-dimensional argument B is implicitly treated as a column matrix
  73      dimensioned [count, 1], so ycount=1.
  74   */
  75
  76   if (retarray->data == NULL)
  77     {
  78       if (GFC_DESCRIPTOR_RANK (a) == 1)
  79         {
  80           retarray->dim[0].lbound = 0;
  81           retarray->dim[0].ubound = b->dim[1].ubound - b->dim[1].lbound;
  82           retarray->dim[0].stride = 1;
  83         }
  84       else if (GFC_DESCRIPTOR_RANK (b) == 1)
  85         {
  86           retarray->dim[0].lbound = 0;
  87           retarray->dim[0].ubound = a->dim[0].ubound - a->dim[0].lbound;
  88           retarray->dim[0].stride = 1;
  89         }
  90       else
  91         {
  92           retarray->dim[0].lbound = 0;
  93           retarray->dim[0].ubound = a->dim[0].ubound - a->dim[0].lbound;
  94           retarray->dim[0].stride = 1;
  95
  96           retarray->dim[1].lbound = 0;
  97           retarray->dim[1].ubound = b->dim[1].ubound - b->dim[1].lbound;
  98           retarray->dim[1].stride = retarray->dim[0].ubound+1;
  99         }
 100
 101       retarray->data
 102         = internal_malloc_size (sizeof (GFC_REAL_8) * size0 ((array_t *) retarray));
 103       retarray->offset = 0;
 104     }
 105
 106   abase = a->data;
 107   bbase = b->data;
 108   dest = retarray->data;
 109
 110   if (retarray->dim[0].stride == 0)
 111     retarray->dim[0].stride = 1;
 112   if (a->dim[0].stride == 0)
 113     a->dim[0].stride = 1;
 114   if (b->dim[0].stride == 0)
 115     b->dim[0].stride = 1;
 116
 117
 118   if (GFC_DESCRIPTOR_RANK (retarray) == 1)
 119     {
 120       /* One-dimensional result may be addressed in the code below
 121          either as a row or a column matrix. We want both cases to
 122          work. */
 123       rxstride = rystride = retarray->dim[0].stride;
 124     }
 125   else
 126     {
 127       rxstride = retarray->dim[0].stride;
 128       rystride = retarray->dim[1].stride;
 129     }
 130
 131
 132   if (GFC_DESCRIPTOR_RANK (a) == 1)
 133     {
 134       /* Treat it as a a row matrix A[1,count]. */
 135       axstride = a->dim[0].stride;
 136       aystride = 1;
 137
 138       xcount = 1;
 139       count = a->dim[0].ubound + 1 - a->dim[0].lbound;
 140     }
 141   else
 142     {
 143       axstride = a->dim[0].stride;
 144       aystride = a->dim[1].stride;
 145
 146       count = a->dim[1].ubound + 1 - a->dim[1].lbound;
 147       xcount = a->dim[0].ubound + 1 - a->dim[0].lbound;
 148     }
 149
 150   assert(count == b->dim[0].ubound + 1 - b->dim[0].lbound);
 151
 152   if (GFC_DESCRIPTOR_RANK (b) == 1)
 153     {
 154       /* Treat it as a column matrix B[count,1] */
 155       bxstride = b->dim[0].stride;
 156
 157       /* bystride should never be used for 1-dimensional b.
 158          in case it is we want it to cause a segfault, rather than
 159          an incorrect result. */
 160       bystride = 0xDEADBEEF;
 161       ycount = 1;
 162     }
 163   else
 164     {
 165       bxstride = b->dim[0].stride;
 166       bystride = b->dim[1].stride;
 167       ycount = b->dim[1].ubound + 1 - b->dim[1].lbound;
 168     }
 169
 170   abase = a->data;
 171   bbase = b->data;
 172   dest = retarray->data;
 173
 174   if (rxstride == 1 && axstride == 1 && bxstride == 1)
 175     {
 176       GFC_REAL_8 *bbase_y;
 177       GFC_REAL_8 *dest_y;
 178       GFC_REAL_8 *abase_n;
 179       GFC_REAL_8 bbase_yn;
 180
 181       if (rystride == ycount)
 182         memset (dest, 0, (sizeof (GFC_REAL_8) * size0((array_t *) retarray)));
 183       else
 184         {
 185           for (y = 0; y < ycount; y++)
 186             for (x = 0; x < xcount; x++)
 187               dest[x + y*rystride] = (GFC_REAL_8)0;
 188         }
 189
 190       for (y = 0; y < ycount; y++)
 191         {
 192           bbase_y = bbase + y*bystride;
 193           dest_y = dest + y*rystride;
 194           for (n = 0; n < count; n++)
 195             {
 196               abase_n = abase + n*aystride;
 197               bbase_yn = bbase_y[n];
 198               for (x = 0; x < xcount; x++)
 199                 {
 200                   dest_y[x] += abase_n[x] * bbase_yn;
 201                 }
 202             }
 203         }
 204     }
 205   else
 206     {
 207       for (y = 0; y < ycount; y++)
 208         for (x = 0; x < xcount; x++)
 209           dest[x*rxstride + y*rystride] = (GFC_REAL_8)0;
 210
 211       for (y = 0; y < ycount; y++)
 212         for (n = 0; n < count; n++)
 213           for (x = 0; x < xcount; x++)
 214             /* dest[x,y] += a[x,n] * b[n,y] */
 215             dest[x*rxstride + y*rystride] += abase[x*axstride + n*aystride] * bbase[n*bxstride + y*bystride];
 216     }
 217 }