From: Toon Moene <toon@moene.indiv.nluug.nl>
To: egcs@cygnus.com
Subject: Re: [EGCS] Re: double alignment patch for x86
Date: Sun, 17 Aug 1997 21:48:08 -0000 [thread overview]
Message-ID: <9708172035.AA19136@moene.indiv.nluug.nl> (raw)
In-Reply-To: [EGCS] Re: double alignment patch for x86
Marc,
> It takes 2 additional cycles per double access.. this
> can sum up to 30% runtime penalty on important algorithms
> like matrix multiply...
This is on a Pentium ? My brother did some experiments on his PPro
180 for me with a code that had almost all DOUBLE PRECISION data in
COMMON BLOCKS.
Without -malign-double, the code took 18 seconds, with
-malign-double 10 seconds, i.e. a factor of almost 2.
> It was a actually physicist that actually pointed this
> out to me (and H.J.Lu for the libc, I believe).
We're both actual physicists :-)
Cheers,
Toon.
next reply other threads:[~1997-08-17 21:48 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
1997-08-17 21:48 Toon Moene [this message]
-- strict thread matches above, loose matches on Subject: below --
1997-08-19 19:45 Marc Lehmann
1998-02-09 2:10 ` Jeffrey A Law
1997-08-18 8:22 2 (small?) problems Thomas Hiller
1997-08-18 13:29 ` [EGCS] Re: double alignment patch for x86 Dave Love
1997-08-17 21:48 Marc Lehmann
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