Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10 5/3/83; site ucbcad.UUCP Path: utzoo!linus!decvax!tektronix!ucbcad!ucbesvax.turner From: ucbesvax.turner@ucbcad.UUCP Newsgroups: net.arch Subject: Re: Barrel Shifters - (nf) Message-ID: <239@ucbcad.UUCP> Date: Sun, 10-Jul-83 22:17:43 EDT Article-I.D.: ucbcad.239 Posted: Sun Jul 10 22:17:43 1983 Date-Received: Tue, 12-Jul-83 05:48:03 EDT Sender: notes@ucbcad.UUCP Organization: UC Berkeley, CAD Group Lines: 22 #R:turtleva:-20900:ucbesvax:12800004:000:808 ucbesvax!turner Jul 9 16:56:00 1983 Indeed, I was quite indignant when I discovered that 68000 shift/rotate timing was (sigh) a distinctly linear function of the number of shifts. I suppose barrel shifters do rather horrify the micron-hackers, since it's just a big array of simple switches. How can anything that clean-looking be useful? (Oh know, I don't really believe that they think things like that. How do you say in netspeak? ":-)") But yeah, 32 bits is a lotta bits. 32-bit machines almost *need* to be virtual, I think, since there's so many high order bits sitting around in memory being 0 or 1 most of their lives. Better bit-field support in high-level languages and the use of folding algorithms in loop optimization would both probably help a lot. From the Mental Blocks of Michael Turner, ucbvax!ucbesvax.turner