libgfortran/generated/pack_i4.c

   1 /* Specific implementation of the PACK intrinsic
   2    Copyright (C) 2002-2015 Free Software Foundation, Inc.
   3    Contributed by Paul Brook <paul@nowt.org>
   4
   5 This file is part of the GNU Fortran 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 Ligbfortran 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 #include <string.h>
  30
  31
  32 #if defined (HAVE_GFC_INTEGER_4)
  33
  34 /* PACK is specified as follows:
  35
  36    13.14.80 PACK (ARRAY, MASK, [VECTOR])
  37
  38    Description: Pack an array into an array of rank one under the
  39    control of a mask.
  40
  41    Class: Transformational function.
  42
  43    Arguments:
  44       ARRAY   may be of any type. It shall not be scalar.
  45       MASK    shall be of type LOGICAL. It shall be conformable with ARRAY.
  46       VECTOR  (optional) shall be of the same type and type parameters
  47               as ARRAY. VECTOR shall have at least as many elements as
  48               there are true elements in MASK. If MASK is a scalar
  49               with the value true, VECTOR shall have at least as many
  50               elements as there are in ARRAY.
  51
  52    Result Characteristics: The result is an array of rank one with the
  53    same type and type parameters as ARRAY. If VECTOR is present, the
  54    result size is that of VECTOR; otherwise, the result size is the
  55    number /t/ of true elements in MASK unless MASK is scalar with the
  56    value true, in which case the result size is the size of ARRAY.
  57
  58    Result Value: Element /i/ of the result is the element of ARRAY
  59    that corresponds to the /i/th true element of MASK, taking elements
  60    in array element order, for /i/ = 1, 2, ..., /t/. If VECTOR is
  61    present and has size /n/ > /t/, element /i/ of the result has the
  62    value VECTOR(/i/), for /i/ = /t/ + 1, ..., /n/.
  63
  64    Examples: The nonzero elements of an array M with the value
  65    | 0 0 0 |
  66    | 9 0 0 | may be "gathered" by the function PACK. The result of
  67    | 0 0 7 |
  68    PACK (M, MASK = M.NE.0) is [9,7] and the result of PACK (M, M.NE.0,
  69    VECTOR = (/ 2,4,6,8,10,12 /)) is [9,7,6,8,10,12].
  70
  71 There are two variants of the PACK intrinsic: one, where MASK is
  72 array valued, and the other one where MASK is scalar.  */
  73
  74 void
  75 pack_i4 (gfc_array_i4 *ret, const gfc_array_i4 *array,
  76                const gfc_array_l1 *mask, const gfc_array_i4 *vector)
  77 {
  78   /* r.* indicates the return array.  */
  79   index_type rstride0;
  80   GFC_INTEGER_4 * restrict rptr;
  81   /* s.* indicates the source array.  */
  82   index_type sstride[GFC_MAX_DIMENSIONS];
  83   index_type sstride0;
  84   const GFC_INTEGER_4 *sptr;
  85   /* m.* indicates the mask array.  */
  86   index_type mstride[GFC_MAX_DIMENSIONS];
  87   index_type mstride0;
  88   const GFC_LOGICAL_1 *mptr;
  89
  90   index_type count[GFC_MAX_DIMENSIONS];
  91   index_type extent[GFC_MAX_DIMENSIONS];
  92   int zero_sized;
  93   index_type n;
  94   index_type dim;
  95   index_type nelem;
  96   index_type total;
  97   int mask_kind;
  98
  99   dim = GFC_DESCRIPTOR_RANK (array);
 100
 101   mptr = mask->base_addr;
 102
 103   /* Use the same loop for all logical types, by using GFC_LOGICAL_1
 104      and using shifting to address size and endian issues.  */
 105
 106   mask_kind = GFC_DESCRIPTOR_SIZE (mask);
 107
 108   if (mask_kind == 1 || mask_kind == 2 || mask_kind == 4 || mask_kind == 8
 109 #ifdef HAVE_GFC_LOGICAL_16
 110       || mask_kind == 16
 111 #endif
 112       )
 113     {
 114       /*  Do not convert a NULL pointer as we use test for NULL below.  */
 115       if (mptr)
 116         mptr = GFOR_POINTER_TO_L1 (mptr, mask_kind);
 117     }
 118   else
 119     runtime_error ("Funny sized logical array");
 120
 121   zero_sized = 0;
 122   for (n = 0; n < dim; n++)
 123     {
 124       count[n] = 0;
 125       extent[n] = GFC_DESCRIPTOR_EXTENT(array,n);
 126       if (extent[n] <= 0)
 127        zero_sized = 1;
 128       sstride[n] = GFC_DESCRIPTOR_STRIDE(array,n);
 129       mstride[n] = GFC_DESCRIPTOR_STRIDE_BYTES(mask,n);
 130     }
 131   if (sstride[0] == 0)
 132     sstride[0] = 1;
 133   if (mstride[0] == 0)
 134     mstride[0] = mask_kind;
 135
 136   if (zero_sized)
 137     sptr = NULL;
 138   else
 139     sptr = array->base_addr;
 140
 141   if (ret->base_addr == NULL || unlikely (compile_options.bounds_check))
 142     {
 143       /* Count the elements, either for allocating memory or
 144          for bounds checking.  */
 145
 146       if (vector != NULL)
 147         {
 148           /* The return array will have as many
 149              elements as there are in VECTOR.  */
 150           total = GFC_DESCRIPTOR_EXTENT(vector,0);
 151           if (total < 0)
 152             {
 153               total = 0;
 154               vector = NULL;
 155             }
 156         }
 157       else
 158         {
 159           /* We have to count the true elements in MASK.  */
 160           total = count_0 (mask);
 161         }
 162
 163       if (ret->base_addr == NULL)
 164         {
 165           /* Setup the array descriptor.  */
 166           GFC_DIMENSION_SET(ret->dim[0], 0, total-1, 1);
 167
 168           ret->offset = 0;
 169
 170           /* xmallocarray allocates a single byte for zero size.  */
 171           ret->base_addr = xmallocarray (total, sizeof (GFC_INTEGER_4));
 172
 173           if (total == 0)
 174             return;
 175         }
 176       else
 177         {
 178           /* We come here because of range checking.  */
 179           index_type ret_extent;
 180
 181           ret_extent = GFC_DESCRIPTOR_EXTENT(ret,0);
 182           if (total != ret_extent)
 183             runtime_error ("Incorrect extent in return value of PACK intrinsic;"
 184                            " is %ld, should be %ld", (long int) total,
 185                            (long int) ret_extent);
 186         }
 187     }
 188
 189   rstride0 = GFC_DESCRIPTOR_STRIDE(ret,0);
 190   if (rstride0 == 0)
 191     rstride0 = 1;
 192   sstride0 = sstride[0];
 193   mstride0 = mstride[0];
 194   rptr = ret->base_addr;
 195
 196   while (sptr && mptr)
 197     {
 198       /* Test this element.  */
 199       if (*mptr)
 200         {
 201           /* Add it.  */
 202           *rptr = *sptr;
 203           rptr += rstride0;
 204         }
 205       /* Advance to the next element.  */
 206       sptr += sstride0;
 207       mptr += mstride0;
 208       count[0]++;
 209       n = 0;
 210       while (count[n] == extent[n])
 211         {
 212           /* When we get to the end of a dimension, reset it and increment
 213              the next dimension.  */
 214           count[n] = 0;
 215           /* We could precalculate these products, but this is a less
 216              frequently used path so probably not worth it.  */
 217           sptr -= sstride[n] * extent[n];
 218           mptr -= mstride[n] * extent[n];
 219           n++;
 220           if (n >= dim)
 221             {
 222               /* Break out of the loop.  */
 223               sptr = NULL;
 224               break;
 225             }
 226           else
 227             {
 228               count[n]++;
 229               sptr += sstride[n];
 230               mptr += mstride[n];
 231             }
 232         }
 233     }
 234
 235   /* Add any remaining elements from VECTOR.  */
 236   if (vector)
 237     {
 238       n = GFC_DESCRIPTOR_EXTENT(vector,0);
 239       nelem = ((rptr - ret->base_addr) / rstride0);
 240       if (n > nelem)
 241         {
 242           sstride0 = GFC_DESCRIPTOR_STRIDE(vector,0);
 243           if (sstride0 == 0)
 244             sstride0 = 1;
 245
 246           sptr = vector->base_addr + sstride0 * nelem;
 247           n -= nelem;
 248           while (n--)
 249             {
 250               *rptr = *sptr;
 251               rptr += rstride0;
 252               sptr += sstride0;
 253             }
 254         }
 255     }
 256 }
 257
 258 #endif
 259