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Re: optimizing predictable branches on x86

From: "J.C. Pizarro" <jcpiza at gmail dot com>
To: "Nick Piggin" <nickpiggin at yahoo dot com dot au>, GCC <gcc at gcc dot gnu dot org>, "Jan Hubicka" <hubicka at ucw dot cz>
Date: Tue, 26 Feb 2008 18:26:14 +0100
Subject: Re: optimizing predictable branches on x86
References: <998d0e4a0802260806i5d5b1becn2e630770b8579bf8@mail.gmail.com> <998d0e4a0802260832y50904422k6feb8a1b1475fe93@mail.gmail.com>

It's a final summary for good performance of the tested machines:

  + unpredictable: * don't use conditional jmp (the worst).
 /                 * use cmov or C version.
/
\                 + no deps: * use cmov or C version.
 \               /
  + predictable: \
                  + has deps: * don't use cmov (the worst).
                              * use conditional jmp (the best).

Follow-Ups:
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References:
- Re: optimizing predictable branches on x86
  - From: J.C. Pizarro
- Re: optimizing predictable branches on x86
  - From: J.C. Pizarro

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