libgfortran/m4/in_pack.m4

   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 include(types.m4)dnl
  27 define(rtype_kind, regexp(file, `_.\([0-9]+\)\.', `\1'))dnl
  28 define(rtype_letter, regexp(file, `_\(.\)[0-9]+\.', `\1'))dnl
  29 define(rtype_code,rtype_letter`'rtype_name)dnl
  30 define(rtype,get_arraytype(rtype_letter,rtype_kind))dnl
  31 define(rtype_name, get_typename(rtype_letter, rtype_kind))dnl
  32
  33
  34 /* Allocates a block of memory with internal_malloc if the array needs
  35    repacking.  */
  36
  37 dnl Only the kind (ie size) is used to name the function.
  38 rtype_name *
  39 `internal_pack_'rtype_kind (rtype * source)
  40 {
  41   index_type count[GFC_MAX_DIMENSIONS - 1];
  42   index_type extent[GFC_MAX_DIMENSIONS - 1];
  43   index_type stride[GFC_MAX_DIMENSIONS - 1];
  44   index_type stride0;
  45   index_type dim;
  46   index_type ssize;
  47   const rtype_name *src;
  48   rtype_name *dest;
  49   rtype_name *destptr;
  50   int n;
  51   int packed;
  52
  53   if (source->dim[0].stride == 0)
  54     {
  55       source->dim[0].stride = 1;
  56       return source->data;
  57     }
  58
  59   dim = GFC_DESCRIPTOR_RANK (source);
  60   ssize = 1;
  61   packed = 1;
  62   for (n = 0; n < dim; n++)
  63     {
  64       count[n] = 0;
  65       stride[n] = source->dim[n].stride;
  66       extent[n] = source->dim[n].ubound + 1 - source->dim[n].lbound;
  67       if (extent[n] <= 0)
  68         {
  69           /* Do nothing.  */
  70           packed = 1;
  71           break;
  72         }
  73
  74       if (ssize != stride[n])
  75         packed = 0;
  76
  77       ssize *= extent[n];
  78     }
  79
  80   if (packed)
  81     return source->data;
  82
  83   /* Allocate storage for the destination.  */
  84   destptr = (rtype_name *)internal_malloc_size (ssize * rtype_kind);
  85   dest = destptr;
  86   src = source->data;
  87   stride0 = stride[0];
  88
  89
  90   while (src)
  91     {
  92       /* Copy the data.  */
  93       *(dest++) = *src;
  94       /* Advance to the next element.  */
  95       src += stride0;
  96       count[0]++;
  97       /* Advance to the next source element.  */
  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           src -= stride[n] * extent[n];
 107           n++;
 108           if (n == dim)
 109             {
 110               src = NULL;
 111               break;
 112             }
 113           else
 114             {
 115               count[n]++;
 116               src += stride[n];
 117             }
 118         }
 119     }
 120   return destptr;
 121 }
 122