locale/coll-lookup.c

   1 /* Copyright (C) 2000-2017 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Bruno Haible <haible@clisp.cons.org>, 2000.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <stdint.h>
  20
  21 /* Lookup in a table of int32_t, with default value 0.  */
  22 int32_t
  23 __collidx_table_lookup (const char *table, uint32_t wc)
  24 {
  25   uint32_t shift1 = ((const uint32_t *) table)[0];
  26   uint32_t index1 = wc >> shift1;
  27   uint32_t bound = ((const uint32_t *) table)[1];
  28   if (index1 < bound)
  29     {
  30       uint32_t lookup1 = ((const uint32_t *) table)[5 + index1];
  31       if (lookup1 != 0)
  32         {
  33           uint32_t shift2 = ((const uint32_t *) table)[2];
  34           uint32_t mask2 = ((const uint32_t *) table)[3];
  35           uint32_t index2 = (wc >> shift2) & mask2;
  36           uint32_t lookup2 = ((const uint32_t *)(table + lookup1))[index2];
  37           if (lookup2 != 0)
  38             {
  39               uint32_t mask3 = ((const uint32_t *) table)[4];
  40               uint32_t index3 = wc & mask3;
  41               int32_t lookup3 = ((const int32_t *)(table + lookup2))[index3];
  42
  43               return lookup3;
  44             }
  45         }
  46     }
  47   return 0;
  48 }
  49
  50
  51 /* Lookup in a table of uint32_t, with default value 0xffffffff.  */
  52 uint32_t
  53 __collseq_table_lookup (const char *table, uint32_t wc)
  54 {
  55   uint32_t shift1 = ((const uint32_t *) table)[0];
  56   uint32_t index1 = wc >> shift1;
  57   uint32_t bound = ((const uint32_t *) table)[1];
  58   if (index1 < bound)
  59     {
  60       uint32_t lookup1 = ((const uint32_t *) table)[5 + index1];
  61       if (lookup1 != 0)
  62         {
  63           uint32_t shift2 = ((const uint32_t *) table)[2];
  64           uint32_t mask2 = ((const uint32_t *) table)[3];
  65           uint32_t index2 = (wc >> shift2) & mask2;
  66           uint32_t lookup2 = ((const uint32_t *)(table + lookup1))[index2];
  67           if (lookup2 != 0)
  68             {
  69               uint32_t mask3 = ((const uint32_t *) table)[4];
  70               uint32_t index3 = wc & mask3;
  71               uint32_t lookup3 = ((const uint32_t *)(table + lookup2))[index3];
  72
  73               return lookup3;
  74             }
  75         }
  76     }
  77   return ~((uint32_t) 0);
  78 }