Path: utzoo!attcan!uunet!decwrl!megatest!djones
From: djones@megatest.UUCP (Dave Jones)
Newsgroups: comp.lang.c
Subject: Re: general hash functions for text: SUMMARY!
Message-ID: <14308@goofy.megatest.UUCP>
Date: 25 Oct 90 03:41:07 GMT
References: <1990Oct19.040234.20794@watmath.waterloo.edu>
Organization: Megatest Corporation, San Jose, Ca
Lines: 20

I just now popped in to comp.lang.c for a peek. See that string-hashing
is the hot topic. For years I've been using the following hash-function
for tables whose sizes are a power of two. (Dividing by primes is
*slowwww*. Never did understand what it gains.) This is the best I could come
up with for mc68000's. I don't expect that SPARCification will cause me
to change it.

int
String_hash(str)
  	register char *str;
{
  register int retval = 0;
  while(*str)
     retval += retval + (unsigned char)(*str++);
  return retval;
}


I've got an original scheme for rehashing that I just love to show off.
Later maybe.