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glibc  2.9
Functions
weight.h File Reference

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Functions

auto int32_t __attribute ((always_inline)) findidx(const unsigned char **cpp)

Function Documentation

auto int32_t __attribute ( (always_inline)  ) const [inline]

Definition at line 22 of file weight.h.

{
  int_fast32_t i = table[*(*cpp)++];
  const unsigned char *cp;
  const unsigned char *usrc;

  if (i >= 0)
    /* This is an index into the weight table.  Cool.  */
    return i;

  /* Oh well, more than one sequence starting with this byte.
     Search for the correct one.  */
  cp = &extra[-i];
  usrc = *cpp;
  while (1)
    {
      size_t nhere;

      /* The first thing is the index.  */
      i = *((const int32_t *) cp);
      cp += sizeof (int32_t);

      /* Next is the length of the byte sequence.  These are always
        short byte sequences so there is no reason to call any
        function (even if they are inlined).  */
      nhere = *cp++;

      if (i >= 0)
       {
         /* It is a single character.  If it matches we found our
            index.  Note that at the end of each list there is an
            entry of length zero which represents the single byte
            sequence.  The first (and here only) byte was tested
            already.  */
         size_t cnt;

         for (cnt = 0; cnt < nhere; ++cnt)
           if (cp[cnt] != usrc[cnt])
             break;

         if (cnt == nhere)
           {
             /* Found it.  */
             *cpp += nhere;
             return i;
           }

         /* Up to the next entry.  */
         cp += nhere;
         if ((1 + nhere) % __alignof__ (int32_t) != 0)
           cp += __alignof__ (int32_t) - (1 + nhere) % __alignof__ (int32_t);
       }
      else
       {
         /* This is a range of characters.  First decide whether the
            current byte sequence lies in the range.  */
         size_t cnt;
         size_t offset = 0;

         for (cnt = 0; cnt < nhere; ++cnt)
           if (cp[cnt] != usrc[cnt])
             break;

         if (cnt != nhere)
           {
             if (cp[cnt] > usrc[cnt])
              {
                /* Cannot be in this range.  */
                cp += 2 * nhere;
                if ((1 + 2 * nhere) % __alignof__ (int32_t) != 0)
                  cp += (__alignof__ (int32_t)
                        - (1 + 2 * nhere) % __alignof__ (int32_t));
                continue;
              }

             /* Test against the end of the range.  */
             for (cnt = 0; cnt < nhere; ++cnt)
              if (cp[nhere + cnt] != usrc[cnt])
                break;

             if (cnt != nhere && cp[nhere + cnt] < usrc[cnt])
              {
                /* Cannot be in this range.  */
                cp += 2 * nhere;
                if ((1 + 2 * nhere) % __alignof__ (int32_t) != 0)
                  cp += (__alignof__ (int32_t)
                        - (1 + 2 * nhere) % __alignof__ (int32_t));
                continue;
              }

             /* This range matches the next characters.  Now find
               the offset in the indirect table.  */
             for (cnt = 0; cp[cnt] == usrc[cnt]; ++cnt);

             do
              {
                offset <<= 8;
                offset += usrc[cnt] - cp[cnt];
              }
             while (++cnt < nhere);
           }

         *cpp += nhere;
         return indirect[-i + offset];
       }
    }

  /* NOTREACHED */
  return 0x43219876;
}