Messages in this thread | | | Date | Fri, 10 Sep 1999 00:39:53 +0200 | From | Artur Skawina <> | Subject | Re: [patch] longstanding chksum patch |
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mingo@chiara.csoma.elte.hu wrote: > > On Thu, 9 Sep 1999, Andrea Arcangeli wrote: > > > - testl %esi, %esi > > + clc > > you've just slowed the code down. clc does not pair. testl %esi, %esi > does.
minor correction - actually, as this is 686 code, it does. (i remember playing with this too, and mingo _is_ right - it comes out slower anyway (depending on aligment etc). Actually it's even more interesting -- you can time the difference when using different registers as testl arguments (the testl only has to clear CF so you can just pick one))
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