libgfortran/runtime/in_pack_generic.c

   1 /* Generic helper function for repacking arrays.
   2    Copyright 2003, 2004, 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 <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];
  44   index_type extent[GFC_MAX_DIMENSIONS];
  45   index_type stride[GFC_MAX_DIMENSIONS];
  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   int type;
  56
  57   if (source->dim[0].stride == 0)
  58     {
  59       source->dim[0].stride = 1;
  60       return source->data;
  61     }
  62
  63   type = GFC_DESCRIPTOR_TYPE (source);
  64   size = GFC_DESCRIPTOR_SIZE (source);
  65   switch (type)
  66     {
  67     case GFC_DTYPE_INTEGER:
  68     case GFC_DTYPE_LOGICAL:
  69     case GFC_DTYPE_REAL:
  70       switch (size)
  71         {
  72         case 4:
  73           return internal_pack_4 ((gfc_array_i4 *)source);
  74
  75         case 8:
  76           return internal_pack_8 ((gfc_array_i8 *)source);
  77         }
  78       break;
  79
  80     case GFC_DTYPE_COMPLEX:
  81       switch (size)
  82         {
  83         case 8:
  84           return internal_pack_c4 ((gfc_array_c4 *)source);
  85
  86         case 16:
  87           return internal_pack_c8 ((gfc_array_c8 *)source);
  88         }
  89       break;
  90
  91     default:
  92       break;
  93     }
  94
  95   dim = GFC_DESCRIPTOR_RANK (source);
  96   ssize = 1;
  97   packed = 1;
  98   for (n = 0; n < dim; n++)
  99     {
 100       count[n] = 0;
 101       stride[n] = source->dim[n].stride;
 102       extent[n] = source->dim[n].ubound + 1 - source->dim[n].lbound;
 103       if (extent[n] <= 0)
 104         {
 105           /* Do nothing.  */
 106           packed = 1;
 107           break;
 108         }
 109
 110       if (ssize != stride[n])
 111         packed = 0;
 112
 113       ssize *= extent[n];
 114     }
 115
 116   if (packed)
 117     return source->data;
 118
 119    /* Allocate storage for the destination.  */
 120   destptr = internal_malloc_size (ssize * size);
 121   dest = (char *)destptr;
 122   src = source->data;
 123   stride0 = stride[0] * size;
 124
 125   while (src)
 126     {
 127       /* Copy the data.  */
 128       memcpy(dest, src, size);
 129       /* Advance to the next element.  */
 130       dest += size;
 131       src += stride0;
 132       count[0]++;
 133       /* Advance to the next source element.  */
 134       n = 0;
 135       while (count[n] == extent[n])
 136         {
 137           /* When we get to the end of a dimension, reset it and increment
 138              the next dimension.  */
 139           count[n] = 0;
 140           /* We could precalculate these products, but this is a less
 141              frequently used path so proabably not worth it.  */
 142           src -= stride[n] * extent[n] * size;
 143           n++;
 144           if (n == dim)
 145             {
 146               src = NULL;
 147               break;
 148             }
 149           else
 150             {
 151               count[n]++;
 152               src += stride[n] * size;
 153             }
 154         }
 155     }
 156   return destptr;
 157 }