[Flac-dev] last minute changes

Miroslav Lichvar lichvarm at phoenix.inf.upol.cz
Thu Nov 15 10:53:06 PST 2001

On Wed, Nov 14, 2001 at 09:37:47AM -0800, Josh Coalson wrote:
> cpu support for 3dnow and sse can be easily detected at
> runtime.  I turned off 3dnow by default because it is
> implicated in some crashes.

Hmm, i never have any crash. Can i get more informations about these
crases? Or you are talking about that ones posted in this list about
month ago?

> sse also requires operating system support.  thanks to
> intel's brilliant design, the only real way to do this
> at flac runtime is for the library to fork() itself,
> run some sse instructions in the new process, and watch
> if it crashes.  quietly forking in a library is bad
> since some library users may not want to fork (like
> if their process image is huge) for such a simple
> thing.

Another possible way is in using threads instead of fork/vfork (at
least on UNIX systems). But linking flac with pthread library only for
this stupid detection is ugly.

BTW, line 394 in stream_encoder.c setting 3dnow function is still
disabled. So configure --enable-use-3dnow in fact doesn't enable it.

Miroslav Lichvar
lichvarm at phoenix.inf.upol.cz

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