Newsgroups: sci.math.num-analysis,comp.lang.c
From: Joe Keane <jgk@netcom.com>
Subject: Re: How to compute a # Modulo-63 ???
Message-ID: <jgkDBFw1L.DK2@netcom.com>
Date: Sun, 9 Jul 1995 08:10:33 GMT

Here's some code:
				
int mod63(unsigned long x)	/* x < 2^32 */
{
    unsigned t;

    t = (((x >> 12) + x) >> 10) + (x << 2);
    t = ((t >> 6) + t + 3) & 0xFF;
    return (t - (t >> 6)) >> 2;
}

Why does it work?

--
Joe Keane, amateur mathematician