/* Implements a string hashing function.
  Copyright (C) 1995, 1997, 1998, 2000, 2003 Free Software Foundation, Inc.
  This file is part of the GNU C Library.

  The GNU C Library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.

  The GNU C Library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with the GNU C Library; if not, write to the Free
  Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  Boston, MA 02110-1301, USA.  */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

/* Specification.  */
#include "hash-string.h"


/* Defines the so called `hashpjw' function by P.J. Weinberger
  [see Aho/Sethi/Ullman, COMPILERS: Principles, Techniques and Tools,
  1986, 1987 Bell Telephone Laboratories, Inc.]  */
unsigned long int
__hash_string (const char *str_param)
{
 unsigned long int hval, g;
 const char *str = str_param;

 /* Compute the hash value for the given string.  */
 hval = 0;
 while (*str != '\0')
   {
     hval <<= 4;
     hval += (unsigned char) *str++;
     g = hval & ((unsigned long int) 0xf << (HASHWORDBITS - 4));
     if (g != 0)
       {
         hval ^= g >> (HASHWORDBITS - 8);
         hval ^= g;
       }
   }
 return hval;
}