Re: [PATCH v2 3/4] libav.inc: duplicate armv7a over-rides for armv7ve

Phil Blundell
2016-01-12T09:42:45Z

On Mon, 2016-01-11 at 14:58 -0800, Khem Raj wrote:
> it came into ffmpeg circa 2008 and proliferated into related components primarily to support vectorization and neon
> which was quite nascent for ARM architecture in those days in gcc. Today if you were to configure libav with default options
> then it uses mainly -fomit-frame-pointer-O3 -fno-math-errno -fno-signed-zeros -fno-tree-vectorize
>
> which is primarily -Ofast -fno-tree-vectorize

I think -fno-tree-vectorize is just there as a workaround for old
compilers. It sounds like you're saying that ffmpeg basically just
wants "-Ofast", and by implication it wants this on all architectures.
So in that case there is no need for a FULL_OPTIMIZATION override on
arm, let alone armv7a specifically.

Whether ffmpeg ought to be forcing its own FULL_OPTIMIZATION at all
versus leaving it up to the distro is another question. Personally I
think that individual recipes have no business setting those variables,
and ffmpeg is no exception, but I don't have a particularly strong
opinion either way.

p.