Re: kernel + gcc 4.1 = several problems

From: Linus Torvalds
Date: Wed Jan 03 2007 - 15:31:26 EST




On Wed, 3 Jan 2007, Tim Schmielau wrote:
>
> Well, on a P4 (which is supposed to be soo bad) I get:

Interesting. My P4 gets basically exactly the same timings for the cmov
and branch cases. And my Core 2 is consistently faster (something like
15%) for the branch version.

Btw, the test-case should be the best possible one for cmov, since there
are no data-dependencies except for ALU operations, and everything is
totally independent (the actual values have no data dependencies at all,
since they are constants). So the critical path issue never show up.

Linus
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