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Re: Optimisation puzzle
> From: me
> Newsgroups: gmane.comp.gcc.help
> Subject: Re: Optimisation puzzle
> Date: Wed, 21 Mar 2007 05:24:15 +0100
[]
> Maybe this somehow linked to the fact, that parameter by value are always
> copied and there's no way for caller to know about what happened to that
> *copy*. E.g. "void q(const unsigned int b);" means b is read-only inside q,
> but any caller sets up b for q, i.e it create/change it.
Similar to semantics, described here:
<http://udrepper.livejournal.com/15119.html>
> q: _mtune=k8_ q: _mtune=nocona_
> ..LFB2: .LFB2:
> mov %edi, %edi *NOTE* movsd a(%rip), %xmm1
> movlpd a(%rip), %xmm1 mov %edi, %edi *NOTE*
This ones are still a puzzle (or need rtfm :)...
_____