libgfortran/intrinsics/eoshift0.c

   1 /* Generic implementation of the EOSHIFT intrinsic
   2    Copyright (C) 2002-2014 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 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 #include <string.h>
  30
  31 /* TODO: make this work for large shifts when
  32    sizeof(int) < sizeof (index_type).  */
  33
  34 static void
  35 eoshift0 (gfc_array_char * ret, const gfc_array_char * array,
  36           int shift, const char * pbound, int which, index_type size,
  37           const char *filler, index_type filler_len)
  38 {
  39   /* r.* indicates the return array.  */
  40   index_type rstride[GFC_MAX_DIMENSIONS];
  41   index_type rstride0;
  42   index_type roffset;
  43   char * restrict rptr;
  44   char *dest;
  45   /* s.* indicates the source array.  */
  46   index_type sstride[GFC_MAX_DIMENSIONS];
  47   index_type sstride0;
  48   index_type soffset;
  49   const char *sptr;
  50   const char *src;
  51
  52   index_type count[GFC_MAX_DIMENSIONS];
  53   index_type extent[GFC_MAX_DIMENSIONS];
  54   index_type dim;
  55   index_type len;
  56   index_type n;
  57   index_type arraysize;
  58
  59   /* The compiler cannot figure out that these are set, initialize
  60      them to avoid warnings.  */
  61   len = 0;
  62   soffset = 0;
  63   roffset = 0;
  64
  65   arraysize = size0 ((array_t *) array);
  66
  67   if (ret->base_addr == NULL)
  68     {
  69       int i;
  70
  71       ret->offset = 0;
  72       ret->dtype = array->dtype;
  73       for (i = 0; i < GFC_DESCRIPTOR_RANK (array); i++)
  74         {
  75           index_type ub, str;
  76
  77           ub = GFC_DESCRIPTOR_EXTENT(array,i) - 1;
  78
  79           if (i == 0)
  80             str = 1;
  81           else
  82             str = GFC_DESCRIPTOR_EXTENT(ret,i-1)
  83               * GFC_DESCRIPTOR_STRIDE(ret,i-1);
  84
  85           GFC_DIMENSION_SET(ret->dim[i], 0, ub, str);
  86
  87         }
  88
  89       /* xmallocarray allocates a single byte for zero size.  */
  90       ret->base_addr = xmallocarray (arraysize, size);
  91     }
  92   else if (unlikely (compile_options.bounds_check))
  93     {
  94       bounds_equal_extents ((array_t *) ret, (array_t *) array,
  95                                  "return value", "EOSHIFT");
  96     }
  97
  98   if (arraysize == 0)
  99     return;
 100
 101   which = which - 1;
 102
 103   extent[0] = 1;
 104   count[0] = 0;
 105   sstride[0] = -1;
 106   rstride[0] = -1;
 107   n = 0;
 108   for (dim = 0; dim < GFC_DESCRIPTOR_RANK (array); dim++)
 109     {
 110       if (dim == which)
 111         {
 112           roffset = GFC_DESCRIPTOR_STRIDE_BYTES(ret,dim);
 113           if (roffset == 0)
 114             roffset = size;
 115           soffset = GFC_DESCRIPTOR_STRIDE_BYTES(array,dim);
 116           if (soffset == 0)
 117             soffset = size;
 118           len = GFC_DESCRIPTOR_EXTENT(array,dim);
 119         }
 120       else
 121         {
 122           count[n] = 0;
 123           extent[n] = GFC_DESCRIPTOR_EXTENT(array,dim);
 124           rstride[n] = GFC_DESCRIPTOR_STRIDE_BYTES(ret,dim);
 125           sstride[n] = GFC_DESCRIPTOR_STRIDE_BYTES(array,dim);
 126           n++;
 127         }
 128     }
 129   if (sstride[0] == 0)
 130     sstride[0] = size;
 131   if (rstride[0] == 0)
 132     rstride[0] = size;
 133
 134   dim = GFC_DESCRIPTOR_RANK (array);
 135   rstride0 = rstride[0];
 136   sstride0 = sstride[0];
 137   rptr = ret->base_addr;
 138   sptr = array->base_addr;
 139
 140   if ((shift >= 0 ? shift : -shift) > len)
 141     {
 142       shift = len;
 143       len = 0;
 144     }
 145   else
 146     {
 147       if (shift > 0)
 148         len = len - shift;
 149       else
 150         len = len + shift;
 151     }
 152
 153   while (rptr)
 154     {
 155       /* Do the shift for this dimension.  */
 156       if (shift > 0)
 157         {
 158           src = &sptr[shift * soffset];
 159           dest = rptr;
 160         }
 161       else
 162         {
 163           src = sptr;
 164           dest = &rptr[-shift * roffset];
 165         }
 166       for (n = 0; n < len; n++)
 167         {
 168           memcpy (dest, src, size);
 169           dest += roffset;
 170           src += soffset;
 171         }
 172       if (shift >= 0)
 173         {
 174           n = shift;
 175         }
 176       else
 177         {
 178           dest = rptr;
 179           n = -shift;
 180         }
 181
 182       if (pbound)
 183         while (n--)
 184           {
 185             memcpy (dest, pbound, size);
 186             dest += roffset;
 187           }
 188       else
 189         while (n--)
 190           {
 191             index_type i;
 192
 193             if (filler_len == 1)
 194               memset (dest, filler[0], size);
 195             else
 196               for (i = 0; i < size ; i += filler_len)
 197                 memcpy (&dest[i], filler, filler_len);
 198
 199             dest += roffset;
 200           }
 201
 202       /* Advance to the next section.  */
 203       rptr += rstride0;
 204       sptr += sstride0;
 205       count[0]++;
 206       n = 0;
 207       while (count[n] == extent[n])
 208         {
 209           /* When we get to the end of a dimension, reset it and increment
 210              the next dimension.  */
 211           count[n] = 0;
 212           /* We could precalculate these products, but this is a less
 213              frequently used path so probably not worth it.  */
 214           rptr -= rstride[n] * extent[n];
 215           sptr -= sstride[n] * extent[n];
 216           n++;
 217           if (n >= dim - 1)
 218             {
 219               /* Break out of the loop.  */
 220               rptr = NULL;
 221               break;
 222             }
 223           else
 224             {
 225               count[n]++;
 226               rptr += rstride[n];
 227               sptr += sstride[n];
 228             }
 229         }
 230     }
 231 }
 232
 233
 234 #define DEFINE_EOSHIFT(N)                                                     \
 235   extern void eoshift0_##N (gfc_array_char *, const gfc_array_char *,         \
 236                             const GFC_INTEGER_##N *, const char *,            \
 237                             const GFC_INTEGER_##N *);                         \
 238   export_proto(eoshift0_##N);                                                 \
 239                                                                               \
 240   void                                                                        \
 241   eoshift0_##N (gfc_array_char *ret, const gfc_array_char *array,             \
 242                 const GFC_INTEGER_##N *pshift, const char *pbound,            \
 243                 const GFC_INTEGER_##N *pdim)                                  \
 244   {                                                                           \
 245     eoshift0 (ret, array, *pshift, pbound, pdim ? *pdim : 1,                  \
 246               GFC_DESCRIPTOR_SIZE (array), "\0", 1);                          \
 247   }                                                                           \
 248                                                                               \
 249   extern void eoshift0_##N##_char (gfc_array_char *, GFC_INTEGER_4,           \
 250                                    const gfc_array_char *,                    \
 251                                    const GFC_INTEGER_##N *, const char *,     \
 252                                    const GFC_INTEGER_##N *, GFC_INTEGER_4,    \
 253                                    GFC_INTEGER_4);                            \
 254   export_proto(eoshift0_##N##_char);                                          \
 255                                                                               \
 256   void                                                                        \
 257   eoshift0_##N##_char (gfc_array_char *ret,                                   \
 258                        GFC_INTEGER_4 ret_length __attribute__((unused)),      \
 259                        const gfc_array_char *array,                           \
 260                        const GFC_INTEGER_##N *pshift,                         \
 261                        const char *pbound,                                    \
 262                        const GFC_INTEGER_##N *pdim,                           \
 263                        GFC_INTEGER_4 array_length,                            \
 264                        GFC_INTEGER_4 bound_length __attribute__((unused)))    \
 265   {                                                                           \
 266     eoshift0 (ret, array, *pshift, pbound, pdim ? *pdim : 1,                  \
 267               array_length, " ", 1);                                          \
 268   }                                                                           \
 269                                                                               \
 270   extern void eoshift0_##N##_char4 (gfc_array_char *, GFC_INTEGER_4,          \
 271                                     const gfc_array_char *,                   \
 272                                     const GFC_INTEGER_##N *, const char *,    \
 273                                     const GFC_INTEGER_##N *, GFC_INTEGER_4,   \
 274                                     GFC_INTEGER_4);                           \
 275   export_proto(eoshift0_##N##_char4);                                         \
 276                                                                               \
 277   void                                                                        \
 278   eoshift0_##N##_char4 (gfc_array_char *ret,                                  \
 279                         GFC_INTEGER_4 ret_length __attribute__((unused)),     \
 280                         const gfc_array_char *array,                          \
 281                         const GFC_INTEGER_##N *pshift,                        \
 282                         const char *pbound,                                   \
 283                         const GFC_INTEGER_##N *pdim,                          \
 284                         GFC_INTEGER_4 array_length,                           \
 285                         GFC_INTEGER_4 bound_length __attribute__((unused)))   \
 286   {                                                                           \
 287     static const gfc_char4_t space = (unsigned char) ' ';                     \
 288     eoshift0 (ret, array, *pshift, pbound, pdim ? *pdim : 1,                  \
 289               array_length * sizeof (gfc_char4_t), (const char *) &space,     \
 290               sizeof (gfc_char4_t));                                          \
 291   }
 292
 293 DEFINE_EOSHIFT (1);
 294 DEFINE_EOSHIFT (2);
 295 DEFINE_EOSHIFT (4);
 296 DEFINE_EOSHIFT (8);
 297 #ifdef HAVE_GFC_INTEGER_16
 298 DEFINE_EOSHIFT (16);
 299 #endif