libgfortran/generated/in_pack_i4.c

   1 /* Helper function for repacking arrays.
   2    Copyright 2003 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 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 libgfortran; 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 "libgfortran.h"
  26
  27 /* Allocates a block of memory with internal_malloc if the array needs
  28    repacking.  */
  29
  30 GFC_INTEGER_4 *
  31 internal_pack_4 (gfc_array_i4 * source)
  32 {
  33   index_type count[GFC_MAX_DIMENSIONS - 1];
  34   index_type extent[GFC_MAX_DIMENSIONS - 1];
  35   index_type stride[GFC_MAX_DIMENSIONS - 1];
  36   index_type stride0;
  37   index_type dim;
  38   index_type ssize;
  39   const GFC_INTEGER_4 *src;
  40   GFC_INTEGER_4 *dest;
  41   GFC_INTEGER_4 *destptr;
  42   int n;
  43   int packed;
  44
  45   if (source->dim[0].stride == 0)
  46     {
  47       source->dim[0].stride = 1;
  48       return source->data;
  49     }
  50
  51   dim = GFC_DESCRIPTOR_RANK (source);
  52   ssize = 1;
  53   packed = 1;
  54   for (n = 0; n < dim; n++)
  55     {
  56       count[n] = 0;
  57       stride[n] = source->dim[n].stride;
  58       extent[n] = source->dim[n].ubound + 1 - source->dim[n].lbound;
  59       if (extent[n] <= 0)
  60         {
  61           /* Do nothing.  */
  62           packed = 1;
  63           break;
  64         }
  65
  66       if (ssize != stride[n])
  67         packed = 0;
  68
  69       ssize *= extent[n];
  70     }
  71
  72   if (packed)
  73     return source->data;
  74
  75   /* Allocate storage for the destination.  */
  76   destptr = (GFC_INTEGER_4 *)internal_malloc_size (ssize * 4);
  77   dest = destptr;
  78   src = source->data;
  79   stride0 = stride[0];
  80
  81
  82   while (src)
  83     {
  84       /* Copy the data.  */
  85       *(dest++) = *src;
  86       /* Advance to the next element.  */
  87       src += stride0;
  88       count[0]++;
  89       /* Advance to the next source element.  */
  90       n = 0;
  91       while (count[n] == extent[n])
  92         {
  93           /* When we get to the end of a dimension, reset it and increment
  94              the next dimension.  */
  95           count[n] = 0;
  96           /* We could precalculate these products, but this is a less
  97              frequently used path so proabably not worth it.  */
  98           src -= stride[n] * extent[n];
  99           n++;
 100           if (n == dim)
 101             {
 102               src = NULL;
 103               break;
 104             }
 105           else
 106             {
 107               count[n]++;
 108               src += stride[n];
 109             }
 110         }
 111     }
 112   return destptr;
 113 }
 114