From:	"Alexei A. Frounze" <dummy_addressee AT hotmail DOT com>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: either I'm stupid or GCC once again has random behaviour
Date:	Fri, 5 Jan 2001 16:13:08 -0500
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does this really has to do anything with memset() ?

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Alexei A. Frounze
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frounze [AT] ece [DOT] rochester [DOT] edu
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"Damian Yerrick" <Bullcr_pd_yerrick AT hotmail DOT comRemoveBullcr_p> wrote in
message news:tcmb5t4e6r50eidnqsfp6kkkqrgsc5qta7 AT 4ax DOT com...
> On Tue, 2 Jan 2001 17:41:07 -0500, "Alexei A. Frounze"
> <dummy_addressee AT hotmail DOT com> wrote:
>
> >Why unrolling? There is a perfect instruction REP STOSB/W/D.
> >What do you mean?
>
> On modern x86 CPUs a loop of simple instructions (which can be split
> among the U and V (and W in PII) pipelines) is actually _faster_ than
> the string instructions (which are complex, run in microcode, and can
> fit only in U).  To fit code into the pipeline without time-consuming
> branching, unrolling loops is a necessity.

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