i.MX6 - mfpu=vfpv3-d16 vs -mfpu=neon

[WarheadsSE]

While compiling pcsx_rearmed I set the option to enable neon.

$this->bbcode_second_pass_code('', './configure --platform=libretro --enable-neon')

This produced countless errors. I did some research and found out that the issue has to do with how I'm setting the mfpu in the CFLAGS. I changed the mfpu to NEON and recompiled. I received no errors this time.

From what I understand, mfpu=vfpv3-d16 was used since it's the lowest common denominator among ARMv7 cpus. I'm wondering if i'm missing out on any performance enhancements due to the base system and installed packages being compiled without neon enabled. Are there any packages I should go back and specifically recompile?

A better formed question: Is there any way to query and find a list of packages that take advantage of neon?

Thanks

[SinOjos]

I have not compiled with arch, but have some experience with using gentoo with imx6. Something in the list might help you out a bit.

http://community.arm.com/groups/tools/b ... mand-lines
http://www.arm.com/products/processors/ ... s/neon.php
http://www.arm.com/products/processors/ ... p-simd.php
http://infocenter.arm.com/help/index.js ... IIFHA.html
https://gcc.gnu.org/onlinedocs/gcc-4.8. ... RM-Options

Your cflags are very important when compiling. Best to be as conservative as possible, and only enabling what you really need. Also watching the compiling text, you will see warning and errors, if something is not right. If you are compiling a lot, setup a distcc cross compiling environment with faster amd64 or x86 computers.

Since Gentoo is compiled from source, you will find a lot of stuff on the Gentoo website and wiki, that will help you considerably for understanding compile settings.