[cfe-commits] [patch] Make ARM NEON polynomial types unsigned

[Tim Northover]

Hi Bob,

> What is the motivation for switching to unsigned?

I personally believe it's a more sane for a polynomial, by quite a
margin. For example it means that casting a poly8_t to a poly16_t will
use the natural embedding rather than converting (say) x^7 into x^15 +
x^14 + ... + x^7.

> Is there something different about AArch64 that makes you
> want to diverge from the de facto standard for those types?

I wouldn't call 2/3 a de facto standard, just a mess.

> If not, it really sounds to me like it might be best to just
> switch everything (including your AArch64 ABI) to use
> signed poly types.

That's not really a viable option at this stage. We're fixing bugs
(not that we expect any, fingers crossed), but not changing the ABI
for things like this.

Cheers.

Tim.