locale/weightwc.h

   1 /* Copyright (C) 1996-2016 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Written by Ulrich Drepper, <drepper@cygnus.com>.
   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 #ifndef _WEIGHTWC_H_
  20 #define _WEIGHTWC_H_    1
  21
  22 /* Find index of weight.  */
  23 static inline int32_t __attribute__ ((always_inline))
  24 findidx (const int32_t *table,
  25          const int32_t *indirect,
  26          const wint_t *extra,
  27          const wint_t **cpp, size_t len)
  28 {
  29   wint_t ch = *(*cpp)++;
  30   int32_t i = __collidx_table_lookup ((const char *) table, ch);
  31
  32   if (i >= 0)
  33     /* This is an index into the weight table.  Cool.  */
  34     return i;
  35
  36   /* Oh well, more than one sequence starting with this byte.
  37      Search for the correct one.  */
  38   const int32_t *cp = (const int32_t *) &extra[-i];
  39   --len;
  40   while (1)
  41     {
  42       size_t nhere;
  43       const int32_t *usrc = (const int32_t *) *cpp;
  44
  45       /* The first thing is the index.  */
  46       i = *cp++;
  47
  48       /* Next is the length of the byte sequence.  These are always
  49          short byte sequences so there is no reason to call any
  50          function (even if they are inlined).  */
  51       nhere = *cp++;
  52
  53       if (i >= 0)
  54         {
  55           /* It is a single character.  If it matches we found our
  56              index.  Note that at the end of each list there is an
  57              entry of length zero which represents the single byte
  58              sequence.  The first (and here only) byte was tested
  59              already.  */
  60           size_t cnt;
  61
  62           for (cnt = 0; cnt < nhere && cnt < len; ++cnt)
  63             if (cp[cnt] != usrc[cnt])
  64               break;
  65
  66           if (cnt == nhere)
  67             {
  68               /* Found it.  */
  69               *cpp += nhere;
  70               return i;
  71             }
  72
  73           /* Up to the next entry.  */
  74           cp += nhere;
  75         }
  76       else
  77         {
  78           /* This is a range of characters.  First decide whether the
  79              current byte sequence lies in the range.  */
  80           size_t cnt;
  81           size_t offset;
  82
  83           for (cnt = 0; cnt < nhere - 1 && cnt < len; ++cnt)
  84             if (cp[cnt] != usrc[cnt])
  85               break;
  86
  87           if (cnt < nhere - 1)
  88             {
  89               cp += 2 * nhere;
  90               continue;
  91             }
  92
  93           if (cp[nhere - 1] > usrc[nhere -1])
  94             {
  95               cp += 2 * nhere;
  96               continue;
  97             }
  98
  99           if (cp[2 * nhere - 1] < usrc[nhere -1])
 100             {
 101               cp += 2 * nhere;
 102               continue;
 103             }
 104
 105           /* This range matches the next characters.  Now find
 106              the offset in the indirect table.  */
 107           offset = usrc[nhere - 1] - cp[nhere - 1];
 108           *cpp += nhere;
 109
 110           return indirect[-i + offset];
 111         }
 112     }
 113
 114   /* NOTREACHED */
 115   return 0x43219876;
 116 }
 117
 118 #endif  /* weightwc.h */