[FFmpeg-devel] [PATCH]doc/platform: Mention musl where x86_32 is not supported

Carl Eugen Hoyos ceffmpeg at gmail.com
Mon Oct 3 14:37:11 EEST 2016


2016-10-03 13:05 GMT+02:00 Guillaume POIRIER <poirierg at gmail.com>:
> Hello,
> On Mon, Oct 3, 2016 at 11:38 AM, Carl Eugen Hoyos <ceffmpeg at gmail.com> wrote:
>> 2016-10-03 3:52 GMT+02:00 Carl Eugen Hoyos <ceffmpeg at gmail.com>:
>>> New patch attached.
>>> +Compilation with @uref{http://www.musl-libc.org/, musl} on x86-64 is supposed
>>> +to work out-of-the-box.
>> Is this true or is it just working by accident?
> AMD64 dictates that float operations must occur with scalar SSE
> operations, so it's not working by accident. It works because float
> operations don't use x87 stack (which is shared with MMX)

Thank you for the explanation!

Ping on the patch:
We will not guard every asm call with emms_c() and Rich will not
change his alloc() implementation for us: Can't we just document
that it doesn't work and return to bugs that we can fix?

Or should we consider to guard the three calls to mallc(), realloc()
and free()?
This works here as expected with 32bit musl but likely does not
fix the underlying issue.

Carl Eugen

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