Implement GetGroupWaveIndex and GetGroupWaveCount

[JoeCitizen]

Implement Group Wave Index and Group Wave Count as proposed by:
https://github.com/microsoft/hlsl-specs/blob/main/proposals/0048-group-wave-index.md

Added two new intrinsics:

• GetGroupWaveIndex - returns the index of the wave in the thread group
• GetGroupWaveCount - returns the number of waves in the thread group

Limited to Shader Model 6.10 and Compute, Mesh, Node and Amp. shaders.

Added basic test.

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[damyanp]

Could you add something to ReleaseNotes.md please?

[damyanp]

Seems to LGTM, but I'm not an expert in this area.

@tex3d - do we need to wait for #7947 to land before merging this?

[tex3d]

We have several SM 6.10 features staged in PRs now. In order to reduce conflicts, I'd like to suggest we make a separate PR reserving the HLSL Intrinsics and the experimental DXIL ops ahead of the rest of the changes.

This means a PR with just the additions to gen_intrin_main.txt, hctdb.py, nullptr , generated changes (hlsl_intrinsic_opcodes.json, DxilConstants.h, DXIL.rst, DxilInstructions.h, DxilOperations.cpp), and initial EmptyLower table entries for gLowerTable in HLOperationLower.cpp.

Of course, this will also depend on getting #7947 in first.

[tex3d]

I've put a PR up for reserving these operations here: #7995.

Once that's merged, this should be rebased onto main, but you won't want some of your changes here.

You don't need the changes in the generated files, or the addition of the HLSL instrinsics in gen_intrin_main.txt or DXIL ops in hctdb.py, or the HL op reservations in hlsl_intrinsic_opcodes.json.

You'll want to take what's in main for HLOperationLower.cpp's gLowerTable, then update the lowering function to TranslateWaveToVal.

[tex3d]

I did a rebase and a test update, while catching a fault with the ordering of the lowering table entries in the opcode reservation change. Since it's not based on this branch (it's a rebase), I put the branch up here:
https://github.com/tex3d/DirectXShaderCompiler/tree/Group-Wave-Intrinsics

You can reset your branch to this and iterate from there to save a bunch of work.

[tex3d]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[s-perron]

The SPIR-V changes look good. I did not review the rest.

[tex3d]

Yeah, this mechanism is a bit of a backstop, and doesn't provide very clear diagnostic. I still think it would be beneficial to have a dedicated check and message for this case, especially since there is no front-end diagnostic that will catch it. But it's not critical that we add that at this time.

[tex3d]

Looks good. I had a minor comment about a dedicated diagnostic for thread-launch node shader, but it's not absolutely necessary to do that.