[FFmpeg-devel] [PATCH] Add cpu flag "c3-2" to configure

Måns Rullgård mans
Tue Feb 26 15:10:25 CET 2008


Zuxy Meng wrote:
> Hi,
>
> 2008/2/26, M?ns Rullg?rd <mans at mansr.com>:
>>
>> Enrico wrote:
>> > Hi, the attached patch adds support for configure cpu flag "c3-2",
>> > which is the gcc flag i'm using compiling for a VIA Nehemiah cpu.
>> >
>> > It is added in the targets that support cmov
>>
>> What is the latency of the cmov instruction on this CPU?  Is it correct
>> to set fast_cmov?
>
> IIRC C3-2 is of an in-order core and cmov should be at least faster
> than a conditional jump.

The question is which of the two alternatives at cabac.h:472 is faster.
Neither uses a branch.

-- 
M?ns Rullg?rd
mans at mansr.com




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