[Mesa-dev] [PATCH] nir/linker: Add nir_link_uniforms()

[Timothy Arceri]

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I'll reply to the above snipped section in a separate email.

>>
>> Ignoring the above issue I'm fairly certain adding a dependency on 
>> core mesa GL to NIR is a no no so either way these files don't belong 
>> in src/compiler/nir
> 
> But we already have that dependency, right? I mean gl_program have a 
> reference to nir_shader for some time now.

This is largely historical when NIR was created we had no Vulkan drivers 
and it originally lived in src/glsl/nir I have a feeling we can get rid 
of most of these old dependencies by moving some GL only helpers out of 
the src/compiler/nir dir, I might give this a go.

> 
> And in any case, the implementation of ARB_gl_spirv is based on NIR, as 
> right now we don't have an alternative to process SPIR-V. So for 
> example, the following patch (already merged on master) [3]:
>    mesa/glspirv: Add a _mesa_spirv_to_nir() function
>    This is basically a wrapper around spirv_to_nir() that includes 
> arguments setup and post-conversion validation.
> 
> Is at main/glspirv.c, and calls directly spirv_to_nir.
> 
> Although it is true that code would not be called unless the extension 
> is enabled, it depends on NIR and it is included on core mesa 
> (main/gl_spirv.c).
> 
> Well, unless I'm misunderstanding what do you mean for core mesa. I'm 
> including mesa/main as core mesa too.

A dependency on NIR from Mesa is fine, I'm saying NIR (the core library) 
shouldn't have dependencies on core Mesa.

> 
> In any case, I'm not against moving those files to a different directory 
> if needed, just trying to understand why doesn't belong there.

In patch 12 & 16 you are creating a "util" so you can call things from 
the helpers you are placing in the nir dir but these are GL only 
concepts. The util is not a real util that is shared by the vulkan and 
gl compiler but rather you are working around a dependency problem you 
have created by locating the uniform linker and other helpers inside the 
nir directory. You are simply bundling code into builds of Vulkan 
drivers that will never be used.

If you simply put these files inside src/compiler/glsl/ then you don't 
need this util at all. It would probably make more sense now that this 
extension has come along if the dir was actually src/compiler/gl/ but 
its not worth the hassle of changing that.

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