> 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 :)... _____
