hash.cc revision 58551 
1/*
2Copyright (C) 1990 Free Software Foundation
3    written by Doug Lea (dl@rocky.oswego.edu)
4
5This file is part of the GNU C++ Library.  This library is free
6software; you can redistribute it and/or modify it under the terms of
7the GNU Library General Public License as published by the Free
8Software Foundation; either version 2 of the License, or (at your
9option) any later version.  This library is distributed in the hope
10that it will be useful, but WITHOUT ANY WARRANTY; without even the
11implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
12PURPOSE.  See the GNU Library General Public License for more details.
13You should have received a copy of the GNU Library General Public
14License along with this library; if not, write to the Free Software
15Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
16*/
17
18#include <hash.h>
19
20/*
21 some useful hash functions
22*/
23
24unsigned int hashpjw (const char* x) // From Dragon book, p436
25{
26  unsigned int h = 0;
27  unsigned int g;
28
29  while (*x != 0)
30  {
31    h = (h << 4) + (unsigned char) *x++;
32    if ((g = h & 0xf0000000) != 0)
33      h = (h ^ (g >> 24)) ^ g;
34  }
35  return h;
36}
37