Xref: utzoo comp.lang.fortran:1524 comp.lang.misc:2180
Path: utzoo!attcan!uunet!husc6!mailrus!uflorida!ufqtp!bernhold
From: bernhold@qtp.ufl.edu (David E. Bernholdt)
Newsgroups: comp.lang.fortran,comp.lang.misc
Subject: Re: Branch frequencies (was Assembly or ....)
Message-ID: <391@red17.qtp.ufl.edu>
Date: 28 Nov 88 14:42:52 GMT
References: <4113@enea.se>
Reply-To: bernhold@red17 (David E. Bernholdt)
Organization: University of Florida Quantum Theory Project
Lines: 29

In article <4113@enea.se> sommar@enea.se (Erland Sommarskog) writes:
>If memory serves right the compiler Rubin wants exists, or
>at least it has existed. I recall a friend of mine told me
>that the very first Fortran compiler allowed you to give
>probabilities of on the IF statements. The compiler then used
>one of its passes to do a Monte Carlo simulation on the
>program for optimal optimising.
>
>"Frequently, unexpected errors are entirely unpredictable" - Digital Equipment


I too may be mistaken, but I believe that the compiler for the
Multiflow does things like this too: in order to schedule the "traces"
most efficiently, it will analyze the branch condition and try to
determine probabilities.  Furthermore, I believe you can automatically
instrument the executable during compilation and run a few jobs with
it - then feed the collected data back to the compiler to help it
optimize more efficiently.

Warning: I don't really know much about the machine, I just listened
to a Multiflow rep making his pitch to a large group of computation
chemists who ask good questions.  Sounds interesting nevertheless!

Dave
-- 
David Bernholdt			bernhold@qtp.ufl.edu
Quantum Theory Project		bernhold@ufpine.bitnet
University of Florida
Gainesville, FL  32611		904/392 9306