AltiVec support

[Gelbpunkt]

Hi there, thanks a lot for this awesome crate! I was wondering if it would be possible for you to add AltiVec/VSX support for accelerated UTF-8 validation on PowerPC. This is nightly-only, similar to the ARMv7 NEON.

[hkratz]

I will have a look. I guess I can test it using qemu. @Gelbpunkt Do you have access to actual hardware and would you be willing to test/benchmark once I have a prototypical implementation?

[Gelbpunkt]

I will have a look. I guess I can test it using qemu. @Gelbpunkt Do you have access to actual hardware and would you be willing to test/benchmark once I have a prototypical implementation?

Yes, I have a POWER8 server and would happily run benchmarks for you.

[Gelbpunkt]

Hi @hkratz, just letting you know that I can provide you with a temporary VM on POWER hardware and SSH access if you'd like to develop and test on actual hardware - just let me know if that'd help and I can get you hooked up :) (temporary as in until you're done, and after that I can offer hosting a GitHub actions runner for you)