> Is it a problem if all the files are compiled with -march=pentium3 > ? The patch that we sent in already detects in the configure.in script > which system you are on and sets a define correctly, i.e. _USE_SSE.Well, if what you want is auto-detection, turning on -march=pentium3 means that the code will crash on anything lower than a pentium3. Not really useful. Of course, you can make it auto-detect at compile-time, but that means you can't use the same binary on SSE and non-SSE machines. Jean-Marc -- Jean-Marc Valin, M.Sc.A., ing. jr. LABORIUS (http://www.gel.usherb.ca/laborius) Université de Sherbrooke, Québec, Canada -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 190 bytes Desc: Ceci est une partie de message numériquement signée. Url : http://lists.xiph.org/pipermail/speex-dev/attachments/20040121/47a4e499/signature-0001.pgp
> Am I right with the assumption, that currently you have to enable > processor specific optimizations with compile/configure options? > > How difficult would it be to add support for runtime CPU detection? > Is this a feature you might consider adding?Pretty complicated because of some annoying decisions taken by the gcc team. The problem is that gcc won't let you use intrinsics unless the file is compiled with -march=pentium3 (or higher). Unfortunately, this means you have to put all the SSE stuff in another file, which is complicated for some of the Speex files. Also, you have to find a portable way to get the build system use different compilation switches for different files. Last thing, it also makes the detection function less trivial. Jean-Marc -- Jean-Marc Valin, M.Sc.A., ing. jr. LABORIUS (http://www.gel.usherb.ca/laborius) Université de Sherbrooke, Québec, Canada -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 190 bytes Desc: Ceci est une partie de message numériquement signée. Url : http://lists.xiph.org/pipermail/speex-dev/attachments/20040121/43f1fe97/signature-0001.pgp
Jean-Marc,
Is it a problem if all the files are compiled with -march=pentium3
? The patch that we sent in already detects in the configure.in script
which system you are on and sets a define correctly, i.e. _USE_SSE.
Aron Rosenberg
SightSpeed
At 11:05 AM 1/21/2004, you wrote:> > Am I right with the assumption, that currently you have to enable
> > processor specific optimizations with compile/configure options?
> >
> > How difficult would it be to add support for runtime CPU detection?
> > Is this a feature you might consider adding?
>
>Pretty complicated because of some annoying decisions taken by the gcc
>team. The problem is that gcc won't let you use intrinsics unless the
>file is compiled with -march=pentium3 (or higher). Unfortunately, this
>means you have to put all the SSE stuff in another file, which is
>complicated for some of the Speex files. Also, you have to find a
>portable way to get the build system use different compilation switches
>for different files. Last thing, it also makes the detection function
>less trivial.
>
> Jean-Marc
>
>--
>Jean-Marc Valin, M.Sc.A., ing. jr.
>LABORIUS (http://www.gel.usherb.ca/laborius)
>Université de Sherbrooke, Québec, Canada
<p>--- >8 ----
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