libgfortran/generated/pack_i4.c

   1 /* Specific implementation of the PACK intrinsic
   2    Copyright (C) 2002, 2004, 2005, 2006, 2007, 2008, 2009, 2012
   3    Free Software Foundation, Inc.
   4    Contributed by Paul Brook <paul@nowt.org>
   5
   6 This file is part of the GNU Fortran runtime library (libgfortran).
   7
   8 Libgfortran is free software; you can redistribute it and/or
   9 modify it under the terms of the GNU General Public
  10 License as published by the Free Software Foundation; either
  11 version 3 of the License, or (at your option) any later version.
  12
  13 Ligbfortran is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 Under Section 7 of GPL version 3, you are granted additional
  19 permissions described in the GCC Runtime Library Exception, version
  20 3.1, as published by the Free Software Foundation.
  21
  22 You should have received a copy of the GNU General Public License and
  23 a copy of the GCC Runtime Library Exception along with this program;
  24 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  25 <http://www.gnu.org/licenses/>.  */
  26
  27 #include "libgfortran.h"
  28 #include <stdlib.h>
  29 #include <assert.h>
  30 #include <string.h>
  31
  32
  33 #if defined (HAVE_GFC_INTEGER_4)
  34
  35 /* PACK is specified as follows:
  36
  37    13.14.80 PACK (ARRAY, MASK, [VECTOR])
  38
  39    Description: Pack an array into an array of rank one under the
  40    control of a mask.
  41
  42    Class: Transformational function.
  43
  44    Arguments:
  45       ARRAY   may be of any type. It shall not be scalar.
  46       MASK    shall be of type LOGICAL. It shall be conformable with ARRAY.
  47       VECTOR  (optional) shall be of the same type and type parameters
  48               as ARRAY. VECTOR shall have at least as many elements as
  49               there are true elements in MASK. If MASK is a scalar
  50               with the value true, VECTOR shall have at least as many
  51               elements as there are in ARRAY.
  52
  53    Result Characteristics: The result is an array of rank one with the
  54    same type and type parameters as ARRAY. If VECTOR is present, the
  55    result size is that of VECTOR; otherwise, the result size is the
  56    number /t/ of true elements in MASK unless MASK is scalar with the
  57    value true, in which case the result size is the size of ARRAY.
  58
  59    Result Value: Element /i/ of the result is the element of ARRAY
  60    that corresponds to the /i/th true element of MASK, taking elements
  61    in array element order, for /i/ = 1, 2, ..., /t/. If VECTOR is
  62    present and has size /n/ > /t/, element /i/ of the result has the
  63    value VECTOR(/i/), for /i/ = /t/ + 1, ..., /n/.
  64
  65    Examples: The nonzero elements of an array M with the value
  66    | 0 0 0 |
  67    | 9 0 0 | may be "gathered" by the function PACK. The result of
  68    | 0 0 7 |
  69    PACK (M, MASK = M.NE.0) is [9,7] and the result of PACK (M, M.NE.0,
  70    VECTOR = (/ 2,4,6,8,10,12 /)) is [9,7,6,8,10,12].
  71
  72 There are two variants of the PACK intrinsic: one, where MASK is
  73 array valued, and the other one where MASK is scalar.  */
  74
  75 void
  76 pack_i4 (gfc_array_i4 *ret, const gfc_array_i4 *array,
  77                const gfc_array_l1 *mask, const gfc_array_i4 *vector)
  78 {
  79   /* r.* indicates the return array.  */
  80   index_type rstride0;
  81   GFC_INTEGER_4 * restrict rptr;
  82   /* s.* indicates the source array.  */
  83   index_type sstride[GFC_MAX_DIMENSIONS];
  84   index_type sstride0;
  85   const GFC_INTEGER_4 *sptr;
  86   /* m.* indicates the mask array.  */
  87   index_type mstride[GFC_MAX_DIMENSIONS];
  88   index_type mstride0;
  89   const GFC_LOGICAL_1 *mptr;
  90
  91   index_type count[GFC_MAX_DIMENSIONS];
  92   index_type extent[GFC_MAX_DIMENSIONS];
  93   int zero_sized;
  94   index_type n;
  95   index_type dim;
  96   index_type nelem;
  97   index_type total;
  98   int mask_kind;
  99
 100   dim = GFC_DESCRIPTOR_RANK (array);
 101
 102   mptr = mask->base_addr;
 103
 104   /* Use the same loop for all logical types, by using GFC_LOGICAL_1
 105      and using shifting to address size and endian issues.  */
 106
 107   mask_kind = GFC_DESCRIPTOR_SIZE (mask);
 108
 109   if (mask_kind == 1 || mask_kind == 2 || mask_kind == 4 || mask_kind == 8
 110 #ifdef HAVE_GFC_LOGICAL_16
 111       || mask_kind == 16
 112 #endif
 113       )
 114     {
 115       /*  Do not convert a NULL pointer as we use test for NULL below.  */
 116       if (mptr)
 117         mptr = GFOR_POINTER_TO_L1 (mptr, mask_kind);
 118     }
 119   else
 120     runtime_error ("Funny sized logical array");
 121
 122   zero_sized = 0;
 123   for (n = 0; n < dim; n++)
 124     {
 125       count[n] = 0;
 126       extent[n] = GFC_DESCRIPTOR_EXTENT(array,n);
 127       if (extent[n] <= 0)
 128        zero_sized = 1;
 129       sstride[n] = GFC_DESCRIPTOR_STRIDE(array,n);
 130       mstride[n] = GFC_DESCRIPTOR_STRIDE_BYTES(mask,n);
 131     }
 132   if (sstride[0] == 0)
 133     sstride[0] = 1;
 134   if (mstride[0] == 0)
 135     mstride[0] = mask_kind;
 136
 137   if (zero_sized)
 138     sptr = NULL;
 139   else
 140     sptr = array->base_addr;
 141
 142   if (ret->base_addr == NULL || unlikely (compile_options.bounds_check))
 143     {
 144       /* Count the elements, either for allocating memory or
 145          for bounds checking.  */
 146
 147       if (vector != NULL)
 148         {
 149           /* The return array will have as many
 150              elements as there are in VECTOR.  */
 151           total = GFC_DESCRIPTOR_EXTENT(vector,0);
 152           if (total < 0)
 153             {
 154               total = 0;
 155               vector = NULL;
 156             }
 157         }
 158       else
 159         {
 160           /* We have to count the true elements in MASK.  */
 161           total = count_0 (mask);
 162         }
 163
 164       if (ret->base_addr == NULL)
 165         {
 166           /* Setup the array descriptor.  */
 167           GFC_DIMENSION_SET(ret->dim[0], 0, total-1, 1);
 168
 169           ret->offset = 0;
 170
 171           /* xmalloc allocates a single byte for zero size.  */
 172           ret->base_addr = xmalloc (sizeof (GFC_INTEGER_4) * total);
 173
 174           if (total == 0)
 175             return;
 176         }
 177       else
 178         {
 179           /* We come here because of range checking.  */
 180           index_type ret_extent;
 181
 182           ret_extent = GFC_DESCRIPTOR_EXTENT(ret,0);
 183           if (total != ret_extent)
 184             runtime_error ("Incorrect extent in return value of PACK intrinsic;"
 185                            " is %ld, should be %ld", (long int) total,
 186                            (long int) ret_extent);
 187         }
 188     }
 189
 190   rstride0 = GFC_DESCRIPTOR_STRIDE(ret,0);
 191   if (rstride0 == 0)
 192     rstride0 = 1;
 193   sstride0 = sstride[0];
 194   mstride0 = mstride[0];
 195   rptr = ret->base_addr;
 196
 197   while (sptr && mptr)
 198     {
 199       /* Test this element.  */
 200       if (*mptr)
 201         {
 202           /* Add it.  */
 203           *rptr = *sptr;
 204           rptr += rstride0;
 205         }
 206       /* Advance to the next element.  */
 207       sptr += sstride0;
 208       mptr += mstride0;
 209       count[0]++;
 210       n = 0;
 211       while (count[n] == extent[n])
 212         {
 213           /* When we get to the end of a dimension, reset it and increment
 214              the next dimension.  */
 215           count[n] = 0;
 216           /* We could precalculate these products, but this is a less
 217              frequently used path so probably not worth it.  */
 218           sptr -= sstride[n] * extent[n];
 219           mptr -= mstride[n] * extent[n];
 220           n++;
 221           if (n >= dim)
 222             {
 223               /* Break out of the loop.  */
 224               sptr = NULL;
 225               break;
 226             }
 227           else
 228             {
 229               count[n]++;
 230               sptr += sstride[n];
 231               mptr += mstride[n];
 232             }
 233         }
 234     }
 235
 236   /* Add any remaining elements from VECTOR.  */
 237   if (vector)
 238     {
 239       n = GFC_DESCRIPTOR_EXTENT(vector,0);
 240       nelem = ((rptr - ret->base_addr) / rstride0);
 241       if (n > nelem)
 242         {
 243           sstride0 = GFC_DESCRIPTOR_STRIDE(vector,0);
 244           if (sstride0 == 0)
 245             sstride0 = 1;
 246
 247           sptr = vector->base_addr + sstride0 * nelem;
 248           n -= nelem;
 249           while (n--)
 250             {
 251               *rptr = *sptr;
 252               rptr += rstride0;
 253               sptr += sstride0;
 254             }
 255         }
 256     }
 257 }
 258
 259 #endif
 260