libgfortran/intrinsics/cshift0.c

   1 /* Generic implementation of the CSHIFT intrinsic
   2    Copyright 2003 Free Software Foundation, Inc.
   3    Contributed by Feng Wang <wf_cs@yahoo.com>
   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 2 of the License, or (at your option) any later version.
  11
  12 In addition to the permissions in the GNU General Public License, the
  13 Free Software Foundation gives you unlimited permission to link the
  14 compiled version of this file into combinations with other programs,
  15 and to distribute those combinations without any restriction coming
  16 from the use of this file.  (The General Public License restrictions
  17 do apply in other respects; for example, they cover modification of
  18 the file, and distribution when not linked into a combine
  19 executable.)
  20
  21 Libgfortran is distributed in the hope that it will be useful,
  22 but WITHOUT ANY WARRANTY; without even the implied warranty of
  23 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24 GNU General Public License for more details.
  25
  26 You should have received a copy of the GNU General Public
  27 License along with libgfortran; see the file COPYING.  If not,
  28 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  29 Boston, MA 02111-1307, USA.  */
  30
  31 #include "config.h"
  32 #include <stdlib.h>
  33 #include <assert.h>
  34 #include <string.h>
  35 #include "libgfortran.h"
  36
  37
  38 /* "Templatized" helper function for the inner shift loop.  */
  39
  40 #define DEF_COPY_LOOP(NAME, TYPE)                                       \
  41 static inline void                                                      \
  42 copy_loop_##NAME (void *xdest, const void *xsrc,                        \
  43                   size_t roff, size_t soff,                             \
  44                   index_type len, index_type shift)                     \
  45 {                                                                       \
  46   TYPE *dest = xdest;                                                   \
  47   const TYPE *src;                                                      \
  48   index_type i;                                                         \
  49                                                                         \
  50   roff /= sizeof (TYPE);                                                \
  51   soff /= sizeof (TYPE);                                                \
  52                                                                         \
  53   src = xsrc;                                                           \
  54   src += shift * soff;                                                  \
  55   for (i = 0; i < len - shift; ++i)                                     \
  56     {                                                                   \
  57       *dest = *src;                                                     \
  58       dest += roff;                                                     \
  59       src += soff;                                                      \
  60     }                                                                   \
  61                                                                         \
  62   src = xsrc;                                                           \
  63   for (i = 0; i < shift; ++i)                                           \
  64     {                                                                   \
  65       *dest = *src;                                                     \
  66       dest += roff;                                                     \
  67       src += soff;                                                      \
  68     }                                                                   \
  69 }
  70
  71 DEF_COPY_LOOP(int, int)
  72 DEF_COPY_LOOP(long, long)
  73 DEF_COPY_LOOP(double, double)
  74 DEF_COPY_LOOP(ldouble, long double)
  75
  76
  77 static void
  78 cshift0 (gfc_array_char * ret, const gfc_array_char * array,
  79          ssize_t shift, int which)
  80 {
  81   /* r.* indicates the return array.  */
  82   index_type rstride[GFC_MAX_DIMENSIONS - 1];
  83   index_type rstride0;
  84   index_type roffset;
  85   char *rptr;
  86
  87   /* s.* indicates the source array.  */
  88   index_type sstride[GFC_MAX_DIMENSIONS - 1];
  89   index_type sstride0;
  90   index_type soffset;
  91   const char *sptr;
  92
  93   index_type count[GFC_MAX_DIMENSIONS - 1];
  94   index_type extent[GFC_MAX_DIMENSIONS - 1];
  95   index_type dim;
  96   index_type size;
  97   index_type len;
  98   index_type n;
  99
 100   if (which < 1 || which > GFC_DESCRIPTOR_RANK (array))
 101     runtime_error ("Argument 'DIM' is out of range in call to 'CSHIFT'");
 102
 103   size = GFC_DESCRIPTOR_SIZE (ret);
 104
 105   which = which - 1;
 106
 107   extent[0] = 1;
 108   count[0] = 0;
 109   size = GFC_DESCRIPTOR_SIZE (array);
 110   n = 0;
 111
 112   /* Initialized for avoiding compiler warnings.  */
 113   roffset = size;
 114   soffset = size;
 115   len = 0;
 116
 117   if (ret->data == NULL)
 118     {
 119       int i;
 120
 121       ret->data = internal_malloc_size (size * size0 ((array_t *)array));
 122       ret->base = 0;
 123       ret->dtype = array->dtype;
 124       for (i = 0; i < GFC_DESCRIPTOR_RANK (array); i++)
 125         {
 126           ret->dim[i].lbound = 0;
 127           ret->dim[i].ubound = array->dim[i].ubound - array->dim[i].lbound;
 128
 129           if (i == 0)
 130             ret->dim[i].stride = 1;
 131           else
 132             ret->dim[i].stride = (ret->dim[i-1].ubound + 1) * ret->dim[i-1].stride;
 133         }
 134     }
 135
 136   for (dim = 0; dim < GFC_DESCRIPTOR_RANK (array); dim++)
 137     {
 138       if (dim == which)
 139         {
 140           roffset = ret->dim[dim].stride * size;
 141           if (roffset == 0)
 142             roffset = size;
 143           soffset = array->dim[dim].stride * size;
 144           if (soffset == 0)
 145             soffset = size;
 146           len = array->dim[dim].ubound + 1 - array->dim[dim].lbound;
 147         }
 148       else
 149         {
 150           count[n] = 0;
 151           extent[n] = array->dim[dim].ubound + 1 - array->dim[dim].lbound;
 152           rstride[n] = ret->dim[dim].stride * size;
 153           sstride[n] = array->dim[dim].stride * size;
 154           n++;
 155         }
 156     }
 157   if (sstride[0] == 0)
 158     sstride[0] = size;
 159   if (rstride[0] == 0)
 160     rstride[0] = size;
 161
 162   dim = GFC_DESCRIPTOR_RANK (array);
 163   rstride0 = rstride[0];
 164   sstride0 = sstride[0];
 165   rptr = ret->data;
 166   sptr = array->data;
 167
 168   shift = shift % (ssize_t)len;
 169   if (shift < 0)
 170     shift += len;
 171
 172   while (rptr)
 173     {
 174       /* Do the shift for this dimension.  */
 175
 176       /* If elements are contiguous, perform the operation
 177          in two block moves.  */
 178       if (soffset == size && roffset == size)
 179         {
 180           size_t len1 = shift * size;
 181           size_t len2 = (len - shift) * size;
 182           memcpy (rptr, sptr + len1, len2);
 183           memcpy (rptr + len2, sptr, len1);
 184         }
 185       else
 186         {
 187           /* Otherwise, we'll have to perform the copy one element at
 188              a time.  We can speed this up a tad for common cases of
 189              fundamental types.  */
 190           if (size == sizeof(int))
 191             copy_loop_int (rptr, sptr, roffset, soffset, len, shift);
 192           else if (size == sizeof(long))
 193             copy_loop_long (rptr, sptr, roffset, soffset, len, shift);
 194           else if (size == sizeof(double))
 195             copy_loop_double (rptr, sptr, roffset, soffset, len, shift);
 196           else if (size == sizeof(long double))
 197             copy_loop_ldouble (rptr, sptr, roffset, soffset, len, shift);
 198           else
 199             {
 200               char *dest = rptr;
 201               const char *src = &sptr[shift * soffset];
 202
 203               for (n = 0; n < len - shift; n++)
 204                 {
 205                   memcpy (dest, src, size);
 206                   dest += roffset;
 207                   src += soffset;
 208                 }
 209               for (src = sptr, n = 0; n < shift; n++)
 210                 {
 211                   memcpy (dest, src, size);
 212                   dest += roffset;
 213                   src += soffset;
 214                 }
 215             }
 216         }
 217
 218       /* Advance to the next section.  */
 219       rptr += rstride0;
 220       sptr += sstride0;
 221       count[0]++;
 222       n = 0;
 223       while (count[n] == extent[n])
 224         {
 225           /* When we get to the end of a dimension, reset it and increment
 226              the next dimension.  */
 227           count[n] = 0;
 228           /* We could precalculate these products, but this is a less
 229              frequently used path so proabably not worth it.  */
 230           rptr -= rstride[n] * extent[n];
 231           sptr -= sstride[n] * extent[n];
 232           n++;
 233           if (n >= dim - 1)
 234             {
 235               /* Break out of the loop.  */
 236               rptr = NULL;
 237               break;
 238             }
 239           else
 240             {
 241               count[n]++;
 242               rptr += rstride[n];
 243               sptr += sstride[n];
 244             }
 245         }
 246     }
 247 }
 248
 249
 250 extern void cshift0_1 (gfc_array_char *, const gfc_array_char *,
 251                        const GFC_INTEGER_1 *, const GFC_INTEGER_1 *);
 252 export_proto(cshift0_1);
 253
 254 void
 255 cshift0_1 (gfc_array_char *ret, const gfc_array_char *array,
 256            const GFC_INTEGER_1 *pshift, const GFC_INTEGER_1 *pdim)
 257 {
 258   cshift0 (ret, array, *pshift, pdim ? *pdim : 1);
 259 }
 260
 261
 262 extern void cshift0_2 (gfc_array_char *, const gfc_array_char *,
 263                        const GFC_INTEGER_2 *, const GFC_INTEGER_2 *);
 264 export_proto(cshift0_2);
 265
 266 void
 267 cshift0_2 (gfc_array_char *ret, const gfc_array_char *array,
 268            const GFC_INTEGER_2 *pshift, const GFC_INTEGER_2 *pdim)
 269 {
 270   cshift0 (ret, array, *pshift, pdim ? *pdim : 1);
 271 }
 272
 273
 274 extern void cshift0_4 (gfc_array_char *, const gfc_array_char *,
 275                        const GFC_INTEGER_4 *, const GFC_INTEGER_4 *);
 276 export_proto(cshift0_4);
 277
 278 void
 279 cshift0_4 (gfc_array_char *ret, const gfc_array_char *array,
 280            const GFC_INTEGER_4 *pshift, const GFC_INTEGER_4 *pdim)
 281 {
 282   cshift0 (ret, array, *pshift, pdim ? *pdim : 1);
 283 }
 284
 285
 286 extern void cshift0_8 (gfc_array_char *, const gfc_array_char *,
 287                        const GFC_INTEGER_8 *, const GFC_INTEGER_8 *);
 288 export_proto(cshift0_8);
 289
 290 void
 291 cshift0_8 (gfc_array_char *ret, const gfc_array_char *array,
 292            const GFC_INTEGER_8 *pshift, const GFC_INTEGER_8 *pdim)
 293 {
 294   cshift0 (ret, array, *pshift, pdim ? *pdim : 1);
 295 }
 296