[MPlayer-dev-eng] [PATCH] fast_cmov should be set on x86_64

Zuxy Meng zuxy.meng at gmail.com
Wed Dec 24 10:47:54 CET 2008


2008/12/23 Reimar Döffinger <Reimar.Doeffinger at stud.uni-karlsruhe.de>:
> Hello,
> going by what I read by Intel, cmov should be used on everything but the
> P4s - since the 64 bit case currently does not explicitly detect them,
> only very few with 64 bit support exist, and their performance is horrible
> for multimedia anyway I suggest changing the default:
>
> Index: configure
> ===================================================================
> --- configure   (revision 28181)
> +++ configure   (working copy)
> @@ -1935,6 +1938,7 @@
>     else
>        cpuopt=-mcpu
>     fi
> +    test $_fast_cmov = "auto" && _fast_cmov=yes
>     if test "$_runtime_cpudetection" = no ; then
>       case "$pvendor" in
>       AuthenticAMD)
> @@ -1946,7 +1950,6 @@
>           # 64-bit prescotts exist, but as far as GCC is concerned they
>           # have the same capabilities as a nocona.
>           proc=nocona
> -          test $_fast_cmov = "auto" && _fast_cmov=no
>           ;;
>         esac
>         ;;

Hmmm so we don't care for those who bought a 64-bit P4.

-- 
Zuxy
Beauty is truth,
While truth is beauty.
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