[Pixman] iOS support for ARM NEON

Luca Barbato lu_zero at gentoo.org
Mon Dec 12 16:39:22 PST 2011

On 13/12/11 01:12, Bobby Salazar wrote:
> With hundreds and hundreds of millions of iOS devices sold worldwide
> (all having ARM processors, and the majority having ARMv7 NEON
> support), it would be great to be able to use the ARM NEON fast paths
> in pixman on these platforms.
> Unfortunately, it seems the ARM NEON fast paths are implemented using
> .S assembly files instead of compiler intrinsics. Normally this
> wouldn't be a problem, except that it seems that these .S files
> utilize gcc directives not supported by the Apple version of gcc
> (forked long ago) or even the newer Apple LLVM compiler.

The problem is that the gnu-as provided is ancient.

> I would try to fix this myself, but I just don't understand ARM
> assembly or ARM NEON instructions.
> Is there anyone here who would be willing to work with me to produce a
> version of the .S files compatible with both the normal/modern gcc and
> the Apple versions of gcc? I'm willing to spend the time to compile
> and test the code on these platforms, but I need someone to help edit
> the code, ideally someone who understands it.



It is used to build libav since a long time and is usually up to date.

It should work for pixman as well.



Luca Barbato

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