locale/coll-lookup.c

   1 /* Copyright (C) 2000-2022 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <stdint.h>
  19
  20 /* Lookup in a table of int32_t, with default value 0.  */
  21 int32_t
  22 __collidx_table_lookup (const char *table, uint32_t wc)
  23 {
  24   uint32_t shift1 = ((const uint32_t *) table)[0];
  25   uint32_t index1 = wc >> shift1;
  26   uint32_t bound = ((const uint32_t *) table)[1];
  27   if (index1 < bound)
  28     {
  29       uint32_t lookup1 = ((const uint32_t *) table)[5 + index1];
  30       if (lookup1 != 0)
  31         {
  32           uint32_t shift2 = ((const uint32_t *) table)[2];
  33           uint32_t mask2 = ((const uint32_t *) table)[3];
  34           uint32_t index2 = (wc >> shift2) & mask2;
  35           uint32_t lookup2 = ((const uint32_t *)(table + lookup1))[index2];
  36           if (lookup2 != 0)
  37             {
  38               uint32_t mask3 = ((const uint32_t *) table)[4];
  39               uint32_t index3 = wc & mask3;
  40               int32_t lookup3 = ((const int32_t *)(table + lookup2))[index3];
  41
  42               return lookup3;
  43             }
  44         }
  45     }
  46   return 0;
  47 }
  48
  49
  50 /* Lookup in a table of uint32_t, with default value 0xffffffff.  */
  51 uint32_t
  52 __collseq_table_lookup (const char *table, uint32_t wc)
  53 {
  54   uint32_t shift1 = ((const uint32_t *) table)[0];
  55   uint32_t index1 = wc >> shift1;
  56   uint32_t bound = ((const uint32_t *) table)[1];
  57   if (index1 < bound)
  58     {
  59       uint32_t lookup1 = ((const uint32_t *) table)[5 + index1];
  60       if (lookup1 != 0)
  61         {
  62           uint32_t shift2 = ((const uint32_t *) table)[2];
  63           uint32_t mask2 = ((const uint32_t *) table)[3];
  64           uint32_t index2 = (wc >> shift2) & mask2;
  65           uint32_t lookup2 = ((const uint32_t *)(table + lookup1))[index2];
  66           if (lookup2 != 0)
  67             {
  68               uint32_t mask3 = ((const uint32_t *) table)[4];
  69               uint32_t index3 = wc & mask3;
  70               uint32_t lookup3 = ((const uint32_t *)(table + lookup2))[index3];
  71
  72               return lookup3;
  73             }
  74         }
  75     }
  76   return ~((uint32_t) 0);
  77 }