libgfortran/generated/in_pack_c4.c

   1 /* Helper function for repacking arrays.
   2    Copyright 2003, 2006, 2007, 2009 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 3 of the License, or (at your option) any later version.
  11
  12 Libgfortran 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 General Public License for more details.
  16
  17 Under Section 7 of GPL version 3, you are granted additional
  18 permissions described in the GCC Runtime Library Exception, version
  19 3.1, as published by the Free Software Foundation.
  20
  21 You should have received a copy of the GNU General Public License and
  22 a copy of the GCC Runtime Library Exception along with this program;
  23 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24 <http://www.gnu.org/licenses/>.  */
  25
  26 #include "libgfortran.h"
  27 #include <stdlib.h>
  28 #include <assert.h>
  29
  30
  31 #if defined (HAVE_GFC_COMPLEX_4)
  32
  33 /* Allocates a block of memory with internal_malloc if the array needs
  34    repacking.  */
  35
  36 GFC_COMPLEX_4 *
  37 internal_pack_c4 (gfc_array_c4 * source)
  38 {
  39   index_type count[GFC_MAX_DIMENSIONS];
  40   index_type extent[GFC_MAX_DIMENSIONS];
  41   index_type stride[GFC_MAX_DIMENSIONS];
  42   index_type stride0;
  43   index_type dim;
  44   index_type ssize;
  45   const GFC_COMPLEX_4 *src;
  46   GFC_COMPLEX_4 * restrict dest;
  47   GFC_COMPLEX_4 *destptr;
  48   int n;
  49   int packed;
  50
  51   /* TODO: Investigate how we can figure out if this is a temporary
  52      since the stride=0 thing has been removed from the frontend.  */
  53
  54   dim = GFC_DESCRIPTOR_RANK (source);
  55   ssize = 1;
  56   packed = 1;
  57   for (n = 0; n < dim; n++)
  58     {
  59       count[n] = 0;
  60       stride[n] = GFC_DESCRIPTOR_STRIDE(source,n);
  61       extent[n] = GFC_DESCRIPTOR_EXTENT(source,n);
  62       if (extent[n] <= 0)
  63         {
  64           /* Do nothing.  */
  65           packed = 1;
  66           break;
  67         }
  68
  69       if (ssize != stride[n])
  70         packed = 0;
  71
  72       ssize *= extent[n];
  73     }
  74
  75   if (packed)
  76     return source->data;
  77
  78   /* Allocate storage for the destination.  */
  79   destptr = (GFC_COMPLEX_4 *)internal_malloc_size (ssize * sizeof (GFC_COMPLEX_4));
  80   dest = destptr;
  81   src = source->data;
  82   stride0 = stride[0];
  83
  84
  85   while (src)
  86     {
  87       /* Copy the data.  */
  88       *(dest++) = *src;
  89       /* Advance to the next element.  */
  90       src += stride0;
  91       count[0]++;
  92       /* Advance to the next source element.  */
  93       n = 0;
  94       while (count[n] == extent[n])
  95         {
  96           /* When we get to the end of a dimension, reset it and increment
  97              the next dimension.  */
  98           count[n] = 0;
  99           /* We could precalculate these products, but this is a less
 100              frequently used path so probably not worth it.  */
 101           src -= stride[n] * extent[n];
 102           n++;
 103           if (n == dim)
 104             {
 105               src = NULL;
 106               break;
 107             }
 108           else
 109             {
 110               count[n]++;
 111               src += stride[n];
 112             }
 113         }
 114     }
 115   return destptr;
 116 }
 117
 118 #endif
 119