libgfortran/generated/pack_i8.c

   1 /* Specific implementation of the PACK intrinsic
   2    Copyright (C) 2002, 2004, 2005, 2006, 2007, 2008, 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 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_8)
  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_i8 (gfc_array_i8 *ret, const gfc_array_i8 *array,
  76                const gfc_array_l1 *mask, const gfc_array_i8 *vector)
  77 {
  78   /* r.* indicates the return array.  */
  79   index_type rstride0;
  80   GFC_INTEGER_8 * restrict rptr;
  81   /* s.* indicates the source array.  */
  82   index_type sstride[GFC_MAX_DIMENSIONS];
  83   index_type sstride0;
  84   const GFC_INTEGER_8 *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->data;
 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->data;
 140
 141   if (ret->data == NULL || 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
 161           /* TODO: We could speed up pack easily in the case of only
 162              few .TRUE. entries in MASK, by keeping track of where we
 163              would be in the source array during the initial traversal
 164              of MASK, and caching the pointers to those elements. Then,
 165              supposed the number of elements is small enough, we would
 166              only have to traverse the list, and copy those elements
 167              into the result array. In the case of datatypes which fit
 168              in one of the integer types we could also cache the
 169              value instead of a pointer to it.
 170              This approach might be bad from the point of view of
 171              cache behavior in the case where our cache is not big
 172              enough to hold all elements that have to be copied.  */
 173
 174           const GFC_LOGICAL_1 *m = mptr;
 175
 176           total = 0;
 177           if (zero_sized)
 178             m = NULL;
 179
 180           while (m)
 181             {
 182               /* Test this element.  */
 183               if (*m)
 184                 total++;
 185
 186               /* Advance to the next element.  */
 187               m += mstride[0];
 188               count[0]++;
 189               n = 0;
 190               while (count[n] == extent[n])
 191                 {
 192                   /* When we get to the end of a dimension, reset it
 193                      and increment the next dimension.  */
 194                   count[n] = 0;
 195                   /* We could precalculate this product, but this is a
 196                      less frequently used path so probably not worth
 197                      it.  */
 198                   m -= mstride[n] * extent[n];
 199                   n++;
 200                   if (n >= dim)
 201                     {
 202                       /* Break out of the loop.  */
 203                       m = NULL;
 204                       break;
 205                     }
 206                   else
 207                     {
 208                       count[n]++;
 209                       m += mstride[n];
 210                     }
 211                 }
 212             }
 213         }
 214
 215       if (ret->data == NULL)
 216         {
 217           /* Setup the array descriptor.  */
 218           GFC_DIMENSION_SET(ret->dim[0], 0, total-1, 1);
 219
 220           ret->offset = 0;
 221           if (total == 0)
 222             {
 223               /* In this case, nothing remains to be done.  */
 224               ret->data = internal_malloc_size (1);
 225               return;
 226             }
 227           else
 228             ret->data = internal_malloc_size (sizeof (GFC_INTEGER_8) * total);
 229         }
 230       else
 231         {
 232           /* We come here because of range checking.  */
 233           index_type ret_extent;
 234
 235           ret_extent = GFC_DESCRIPTOR_EXTENT(ret,0);
 236           if (total != ret_extent)
 237             runtime_error ("Incorrect extent in return value of PACK intrinsic;"
 238                            " is %ld, should be %ld", (long int) total,
 239                            (long int) ret_extent);
 240         }
 241     }
 242
 243   rstride0 = GFC_DESCRIPTOR_STRIDE(ret,0);
 244   if (rstride0 == 0)
 245     rstride0 = 1;
 246   sstride0 = sstride[0];
 247   mstride0 = mstride[0];
 248   rptr = ret->data;
 249
 250   while (sptr && mptr)
 251     {
 252       /* Test this element.  */
 253       if (*mptr)
 254         {
 255           /* Add it.  */
 256           *rptr = *sptr;
 257           rptr += rstride0;
 258         }
 259       /* Advance to the next element.  */
 260       sptr += sstride0;
 261       mptr += mstride0;
 262       count[0]++;
 263       n = 0;
 264       while (count[n] == extent[n])
 265         {
 266           /* When we get to the end of a dimension, reset it and increment
 267              the next dimension.  */
 268           count[n] = 0;
 269           /* We could precalculate these products, but this is a less
 270              frequently used path so probably not worth it.  */
 271           sptr -= sstride[n] * extent[n];
 272           mptr -= mstride[n] * extent[n];
 273           n++;
 274           if (n >= dim)
 275             {
 276               /* Break out of the loop.  */
 277               sptr = NULL;
 278               break;
 279             }
 280           else
 281             {
 282               count[n]++;
 283               sptr += sstride[n];
 284               mptr += mstride[n];
 285             }
 286         }
 287     }
 288
 289   /* Add any remaining elements from VECTOR.  */
 290   if (vector)
 291     {
 292       n = GFC_DESCRIPTOR_EXTENT(vector,0);
 293       nelem = ((rptr - ret->data) / rstride0);
 294       if (n > nelem)
 295         {
 296           sstride0 = GFC_DESCRIPTOR_STRIDE(vector,0);
 297           if (sstride0 == 0)
 298             sstride0 = 1;
 299
 300           sptr = vector->data + sstride0 * nelem;
 301           n -= nelem;
 302           while (n--)
 303             {
 304               *rptr = *sptr;
 305               rptr += rstride0;
 306               sptr += sstride0;
 307             }
 308         }
 309     }
 310 }
 311
 312 #endif
 313