Messages in this thread | | | From | Matteo Croce <> | Date | Tue, 10 Nov 2009 23:01:26 +0100 | Subject | Re: i686 quirk for AMD Geode |
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On Tue, Nov 10, 2009 at 9:54 PM, Pavel Machek <pavel@ucw.cz> wrote: > Hi! > >> Indeed, but there is a difference between [cmpxchg, bswap, cmov, nopl] >> on one side and [sse*] on the other : distros are built assuming the >> former are always available while they are not always. And the >> distro > > Well, fix the distros...
$ objdump -d libflashplayer.so |grep cmov -c 10
and ask the companies to fix their binaries too?
>> which make the difference have to provide an dedicated build for earlier >> systems just for compatibility. SSE*, 3dnow* etc... are only used by a >> handful of media players/converters/encoders which are able to detect >> themselves what to use and already have the necessary fallbacks because >> these instruction sets vary too much between processors and vendors. >> >> One could argue that cmpxchg/bswap/xadd are supported by 486 and that >> implementing them for 386 is almost useless now (though it costs almost >> nothing to provide them, I did a few years ago). >> >> CMOV/NOPL are rarely used, thus have no reason to cause a massive >> performance drop, but are frequent enough (at least cmov) for almost > > *One* CMOV in the inner loop will make your performance go down 20x.
Still better than a browser crashing for a SIGILL
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