Re: [PATCH 0/1] MR74: vkd3d-shader/hlsl: Support dot() for SM1.

[Francisco Casas (＠fcasas)]

On Mon Jan 30 14:57:33 2023 +0000, Henri Verbeet wrote:
> There is of course another option: translate this to mul+mad. And that's
> something we'd have to do anyway; dp2add is only supported in shader
> model 2 and up for pixel shaders, and not at all for vertex shaders.

This would need to be a lowering pass, because otherwise you would have to add a new temp in the bytecode. It can work but I am not sure if there will be discrepancies in precision, or if they would matter.

I would go for creating the new `DP2ADD` op (maybe it should be called `HLSL_OP3_DP2ADD`?) and adding the lowering pass for SM1.