Re: [PATCH v18 0/5] MR564: vkd3d-shader/ir: Transform clip/cull signature elements into an array.

[Zebediah Figura (＠zfigura)]

On Fri Feb 23 13:38:55 2024 +0000, Conor McCarthy wrote:
> Indeed it's a bit fragile. It could instead copy up to four components
> to the temp, if available, just in case, but I don't like the idea of
> doing that each time a scalar is loaded. It's pretty spammy in SPIR-V
> code, and the temp is often used for other purposes later, where the
> written values could still be floating around if not overwritten. That's
> unlikely to interfere with optimisation, but I'm not sure.

It's a fair concern. Although if it only matters for clip/cull—not even stores, but *loads*—maybe we don't need to worry about optimization anyway? I'd be (naïvely) surprised if those are frequent.

Longer term we should think about storing this information in a friendlier format at parse time...

I would at least advocate for not using an empty default: case like that; vsir is awfully extensible and we should have a FIXME for unhandled instructions.