Using the Vector API to access SIMD instructions

[Kartik Ohri]

Hi!

> * or switching over the underlying preferred species size and write 3
> specializations for LongVector.SPECIES_[64,128,256], hoping that 2 of
> them are seen as dead code by the runtime compiler's constant folding
> over SPECIES_PREFERRED.
>
> Similarly for the last 4 lines above but on IntVector.SPECIES_[64,128].
>
According to my observations, The JIT is able to do this. For example see:
https://github.com/AugustNagro/utf8.java/pull/5 .

Regards,
Kartik