Path: utzoo!utgpu!bnr-vpa!bnr-rsc!crick
From: crick@bnr-rsc.UUCP (Bill Crick)
Newsgroups: comp.arch
Subject: reusing registers
Keywords: three addresses
Message-ID: <634@bnr-rsc.UUCP>
Date: 10 Mar 88 21:58:51 GMT
Organization: Bell-Northern Research, Ottawa, Canada
Lines: 12


Regarding the issue of two or three address machines: The whole idea
of the large register sets and load/store machines is to keep the live
variables in registers as much as possible. This implies that you want to
reuse operands, which means you would want a three address machine. A two
address machine requires that you copy or stomp an operand every time?
This doesn't seem to be the best way to keep register lives as long as 
possible. I seem to remember an alternate definition of RISC in which
the "R" stood for REUSE of operands. Well? 
  Bill Crick      Bell Northern Research

Computo, Ergo Sum! (V Pbzchgr, Gurersber, V Nz!)