libgfortran/intrinsics/pack_generic.c

   1 /* Generic implementation of the RESHAPE 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 (libgfor).
   6
   7 Libgfor 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 Ligbfor 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 <assert.h>
  25 #include <string.h>
  26 #include "libgfortran.h"
  27
  28 void
  29 __pack (const gfc_array_char * ret, const gfc_array_char * array,
  30     const gfc_array_l4 * mask, const gfc_array_char * vector)
  31 {
  32   /* r.* indicates the return array.  */
  33   index_type rstride0;
  34   char *rptr;
  35   /* s.* indicates the source array.  */
  36   index_type sstride[GFC_MAX_DIMENSIONS];
  37   index_type sstride0;
  38   const char *sptr;
  39   /* m.* indicates the mask array.  */
  40   index_type mstride[GFC_MAX_DIMENSIONS];
  41   index_type mstride0;
  42   const GFC_LOGICAL_4 *mptr;
  43
  44   index_type count[GFC_MAX_DIMENSIONS];
  45   index_type extent[GFC_MAX_DIMENSIONS];
  46   index_type n;
  47   index_type dim;
  48   index_type size;
  49   index_type nelem;
  50
  51   size = GFC_DESCRIPTOR_SIZE (array);
  52   dim = GFC_DESCRIPTOR_RANK (array);
  53   for (n = 0; n < dim; n++)
  54     {
  55       count[n] = 0;
  56       extent[n] = array->dim[n].ubound + 1 - array->dim[n].lbound;
  57       sstride[n] = array->dim[n].stride * size;
  58       mstride[n] = mask->dim[n].stride;
  59     }
  60   if (sstride[0] == 0)
  61     sstride[0] = size;
  62   if (mstride[0] == 0)
  63     mstride[0] = 1;
  64
  65   rstride0 = ret->dim[0].stride * size;
  66   if (rstride0 == 0)
  67     rstride0 = size;
  68   sstride0 = sstride[0];
  69   mstride0 = mstride[0];
  70   rptr = ret->data;
  71   sptr = array->data;
  72   mptr = mask->data;
  73
  74   /* Use the same loop for both logical types. */
  75   if (GFC_DESCRIPTOR_SIZE (mask) != 4)
  76     {
  77       if (GFC_DESCRIPTOR_SIZE (mask) != 8)
  78         runtime_error ("Funny sized logical array");
  79       for (n = 0; n < dim; n++)
  80         mstride[n] <<= 1;
  81       mstride0 <<= 1;
  82       mptr = GFOR_POINTER_L8_TO_L4 (mptr);
  83     }
  84
  85   while (sptr)
  86     {
  87       /* Test this element.  */
  88       if (*mptr)
  89         {
  90           /* Add it.  */
  91           memcpy (rptr, sptr, size);
  92           rptr += rstride0;
  93         }
  94       /* Advance to the next element.  */
  95       sptr += sstride0;
  96       mptr += mstride0;
  97       count[0]++;
  98       n = 0;
  99       while (count[n] == extent[n])
 100         {
 101           /* When we get to the end of a dimension, reset it and increment
 102              the next dimension.  */
 103           count[n] = 0;
 104           /* We could precalculate these products, but this is a less
 105              frequently used path so proabably not worth it.  */
 106           sptr -= sstride[n] * extent[n];
 107           mptr -= mstride[n] * extent[n];
 108           n++;
 109           if (n >= dim)
 110             {
 111               /* Break out of the loop.  */
 112               sptr = NULL;
 113               break;
 114             }
 115           else
 116             {
 117               count[n]++;
 118               sptr += sstride[n];
 119               mptr += mstride[n];
 120             }
 121         }
 122     }
 123
 124   /* Add any remaining elements from VECTOR.  */
 125   if (vector)
 126     {
 127       n = vector->dim[0].ubound + 1 - vector->dim[0].lbound;
 128       nelem = ((rptr - ret->data) / rstride0);
 129       if (n > nelem)
 130         {
 131           sstride0 = vector->dim[0].stride * size;
 132           if (sstride0 == 0)
 133             sstride0 = size;
 134
 135           sptr = vector->data + sstride0 * nelem;
 136           n -= nelem;
 137           while (n--)
 138             {
 139               memcpy (rptr, sptr, size);
 140               rptr += rstride0;
 141               sptr += sstride0;
 142             }
 143         }
 144     }
 145 }
 146