Path: utzoo!attcan!uunet!husc6!bbn!rochester!pt.cs.cmu.edu!andrew.cmu.edu!jk3k+
From: jk3k+@andrew.cmu.edu (Joe Keane)
Newsgroups: comp.arch
Subject: Re: Why is the RT slow?
Message-ID: <cXU-XCy00V48ECDWt=@andrew.cmu.edu>
Date: 15 Nov 88 21:59:42 GMT
References: <5046@polya.Stanford.EDU>
Organization: Carnegie Mellon
Lines: 18
In-Reply-To: <5046@polya.Stanford.EDU>

I get the impression that they were paranoid about code space, giving a
too-complicated instruction set.  To wit:

*  Shift paired.  Where else do they pair registers?

*  `Absolute' branches, with 20 bits of target address.  Gross.

*  The `short' instructions.  No rhyme or reason other than that they save 2
bytes and do common things.

*  Non-execute branch instructions.  Can't just leave a NOP, can we?

*  Four and-immediate instructions.  How about better ways to make constants, so
everyone can benefit?

Just my opinion.

--Joe