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From: Stefan Monnier <monnier@iro.umontreal.ca>
Newsgroups: comp.arch
Subject: Re: Computer architects leaving Intel...
Date: Tue, 10 Sep 2024 15:09:41 -0400
Organization: A noiseless patient Spider
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> Again - sometimes a compiler will recognise a particular hand-optimised
> pattern, turn it back to something logically simpler, then optimise from
> there.  But you cannot /expect/ that.

You might even consider those as performance bugs, since the
hand-optimized code is sometimes chosen specifically to try and impose
a particular kind of code.  Compiler's "optimizations" are usually just
heuristics so compilers are often better off not being "too clever" so
as to allow manual-optimization to override the heuristics: if
programmers want to use the heuristics, they should write
simple&clear code.


        Stefan