| Current Path : /usr/src/contrib/gperf/lib/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
| Current File : //usr/src/contrib/gperf/lib/hash.cc |
/*
Copyright (C) 1990, 2000, 2002 Free Software Foundation
written by Doug Lea <dl@rocky.oswego.edu>
*/
#include <hash.h>
/*
Some useful hash function.
It's not a particularly good hash function (<< 5 would be better than << 4),
but people believe in it because it comes from Dragon book.
*/
unsigned int
hashpjw (const unsigned char *x, unsigned int len) // From Dragon book, p436
{
unsigned int h = 0;
unsigned int g;
for (; len > 0; len--)
{
h = (h << 4) + *x++;
if ((g = h & 0xf0000000) != 0)
h = (h ^ (g >> 24)) ^ g;
}
return h;
}