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From: yodaiken@chelm.cs.umass.edu (victor yodaiken)
Newsgroups: comp.arch
Subject: Re: Register Count
Message-ID: <25118@dime.cs.umass.edu>
Date: 15 Jan 91 01:40:15 GMT
References: <25090@dime.cs.umass.edu> <1991Jan14.191057.14242@rice.edu> <25106@dime.cs.umass.edu> <1991Jan14.233249.21161@rice.edu>
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In article <1991Jan14.233249.21161@rice.edu> foo@erfordia.rice.edu (Mark Hall) writes:
>In article <25106@dime.cs.umass.edu> yodaiken@chelm.cs.umass.edu (victor yodaiken) writes:
>)>Because the path actually taken through the code can't, in general,
>)>be known at compile-time.
>)>
>)>Preston Briggs
>)
>)Still don't see it.  The system state, i.e. contents of store and registers,
>)appears to determine the path taken through a piece of code. 
>
>   I think preston is referring to programs which read input in the 
> phrase "in general".
> 
>   Can you predict the state of registers for all possible 
> (possibly infinite) inputs streams? 
>

Not personally, but in principle, it can be done. The input streams 
comprise a regular language. Thus, we have a finite representation, and 
we have some k, so that any input stream of length greater than k repeats
state.