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From: yodaiken@chelm.cs.umass.edu (victor yodaiken)
Newsgroups: comp.arch
Subject: Re: Register Count
Keywords: superoptimizer, code paths, complexity
Message-ID: <25151@dime.cs.umass.edu>
Date: 15 Jan 91 19:44:52 GMT
References: <11566@pt.cs.cmu.edu> <1991Jan14.163739.10786@rice.edu> <25090@dime.cs.umass.edu> <1991Jan14.191057.14242@rice.edu> <25106@dime.cs.umass.edu> <1991Jan15.165940.2545@news.nd.edu>
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Reply-To: yodaiken@chelm.cs.umass.edu (victor yodaiken)
Organization: University of Massachusetts, Amherst
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In article <1991Jan15.165940.2545@news.nd.edu> przemek@liszt.helios.nd.edu (Przemek Klosowski) writes:
>In article <25106@dime.cs.umass.edu> yodaiken@chelm.cs.umass.edu (victor yodaiken) writes:
>>In article <1991Jan14.191057.14242@rice.edu> preston@ariel.rice.edu (Preston Briggs) writes:
>>>>>especially since optimal choices by the compiler are undecidable.
>>>
>>>and yodaiken@chelm.cs.umass.edu (victor yodaiken) writes:
>>>>How's that? The compiler is allocating a finite set of resources. How
>>
>>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. 
>
>Normally you compile the program in order to run it. If you use the exhaustive
>strategy you propose, there is no need to run the program at all---the compiler
>would actually run the program, and instead of producing the executable it 
>might as well give the program's output...
>	
>--
>			przemek klosowski (przemek@ndcvx.cc.nd.edu)
>			Physics Dept
>			University of Notre Dame IN 46556

I did not propose the exhaustive strategy as a practical engineering
device. Instead, I wanted to argue  that Turing undecidability
has little to do with compilation.