freebsd-src/contrib/gperf/lib/hash.cc
2000-03-25 07:45:29 +00:00

37 lines
1.1 KiB
C++

/*
Copyright (C) 1990 Free Software Foundation
written by Doug Lea (dl@rocky.oswego.edu)
This file is part of the GNU C++ Library. This library is free
software; you can redistribute it and/or modify it under the terms of
the GNU Library General Public License as published by the Free
Software Foundation; either version 2 of the License, or (at your
option) any later version. This 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 Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free Software
Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <hash.h>
/*
some useful hash functions
*/
unsigned int hashpjw (const char* x) // From Dragon book, p436
{
unsigned int h = 0;
unsigned int g;
while (*x != 0)
{
h = (h << 4) + (unsigned char) *x++;
if ((g = h & 0xf0000000) != 0)
h = (h ^ (g >> 24)) ^ g;
}
return h;
}