libgfortran/runtime/in_pack_generic.c

   1 /* Generic 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 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., 59 Temple Place - Suite 330,
  29 Boston, MA 02111-1307, USA.  */
  30
  31 #include "config.h"
  32 #include <stdlib.h>
  33 #include <assert.h>
  34 #include <string.h>
  35 #include "libgfortran.h"
  36
  37 extern void *internal_pack (gfc_array_char *);
  38 export_proto(internal_pack);
  39
  40 void *
  41 internal_pack (gfc_array_char * source)
  42 {
  43   index_type count[GFC_MAX_DIMENSIONS - 1];
  44   index_type extent[GFC_MAX_DIMENSIONS - 1];
  45   index_type stride[GFC_MAX_DIMENSIONS - 1];
  46   index_type stride0;
  47   index_type dim;
  48   index_type ssize;
  49   const char *src;
  50   char *dest;
  51   void *destptr;
  52   int n;
  53   int packed;
  54   index_type size;
  55
  56   if (source->dim[0].stride == 0)
  57     {
  58       source->dim[0].stride = 1;
  59       return source->data;
  60     }
  61
  62   size = GFC_DESCRIPTOR_SIZE (source);
  63   switch (size)
  64     {
  65     case 4:
  66       return internal_pack_4 ((gfc_array_i4 *)source);
  67
  68     case 8:
  69       return internal_pack_8 ((gfc_array_i8 *)source);
  70     }
  71
  72   dim = GFC_DESCRIPTOR_RANK (source);
  73   ssize = 1;
  74   packed = 1;
  75   for (n = 0; n < dim; n++)
  76     {
  77       count[n] = 0;
  78       stride[n] = source->dim[n].stride;
  79       extent[n] = source->dim[n].ubound + 1 - source->dim[n].lbound;
  80       if (extent[n] <= 0)
  81         {
  82           /* Do nothing.  */
  83           packed = 1;
  84           break;
  85         }
  86
  87       if (ssize != stride[n])
  88         packed = 0;
  89
  90       ssize *= extent[n];
  91     }
  92
  93   if (packed)
  94     return source->data;
  95
  96    /* Allocate storage for the destination.  */
  97   destptr = internal_malloc_size (ssize * size);
  98   dest = (char *)destptr;
  99   src = source->data;
 100   stride0 = stride[0] * size;
 101
 102   while (src)
 103     {
 104       /* Copy the data.  */
 105       memcpy(dest, src, size);
 106       /* Advance to the next element.  */
 107       dest += size;
 108       src += stride0;
 109       count[0]++;
 110       /* Advance to the next source element.  */
 111       n = 0;
 112       while (count[n] == extent[n])
 113         {
 114           /* When we get to the end of a dimension, reset it and increment
 115              the next dimension.  */
 116           count[n] = 0;
 117           /* We could precalculate these products, but this is a less
 118              frequently used path so proabably not worth it.  */
 119           src -= stride[n] * extent[n] * size;
 120           n++;
 121           if (n == dim)
 122             {
 123               src = NULL;
 124               break;
 125             }
 126           else
 127             {
 128               count[n]++;
 129               src += stride[n] * size;
 130             }
 131         }
 132     }
 133   return destptr;
 134 }