Path: utzoo!attcan!uunet!husc6!yale!cs.utexas.edu!usc!apple!baum
From: baum@Apple.COM (Allen J. Baum)
Newsgroups: comp.arch
Subject: Re: Register Allocation and Aliasing
Message-ID: <42805@apple.Apple.COM>
Date: 9 Jul 90 17:17:41 GMT
References: <1990Jul9.073203.3358@xavax.com>
Reply-To: baum@apple.UUCP (Allen Baum)
Organization: Apple Computer, Inc.
Lines: 19

[]
>In article <1990Jul9.073203.3358@xavax.com> alvitar@xavax.com (Phillip Harbison) writes:
....
>This sounds like an interesting idea.  What if we just added a tag
>to each register in the CPU.  The tag would store the address which
>the register represents.

Then again, why not just use ATT CRISP chips? Their 'register' file is
really a 'top-of-stack' cache. CRISP is a memory-to-memory architecture,
so there really are no registers, but one of its four addressing modes
is stack-pointer-relative, with a 5 bit displacement, which effectively
gives you 32 registers. If you go indirect through these 'registers', and
it hits in the cache, it gets it from the 'registers' automagically.
Procedure calls can advance the stack pointer, which gives you variable
size register windows.

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