[flac-dev] 1.21 vs 1.3 encoding speed

Miroslav Lichvar
Tue, 29 Jul 2014 10:27:41 -0000

On Tue, Jul 29, 2014 at 07:47:33PM +1000, Erik de Castro Lopo
wrote:
> Miroslav Lichvar wrote:
>
> > Well, this reverts the commit 18e0154. How is the user supposed to set
> > CFLAGS without getting -O3 -funroll-loops there? (e.g. to minimize the
> > size of the compiled binaries)
>
> Is it -O3 or -funroll-loops that you have a problem with? Or both?
> What would you prefer to see as the default optimisation level?

The -funroll-loops option improves the encoding speed, but it seems to
increase the size significantly. I'm not suggesting to remove it from
the default CFLAGS, just have an option to fully override them.

> I'm sure there is a solution to this. Lets find it.

It would be nice if -funroll-loops was used only for the
stream_encoder.c file, that's where it seems to matter most.

I'm not sure if there is a better way to do this in automake, in the
Fedora flac package I used this patch:

http://pkgs.fedoraproject.org/cgit/flac.git/plain/flac-1.2.1-cflags.patch?id=66a59af0bdc5ae4a719aac5d4a8c41817906a01f

--
Miroslav Lichvar