Add tests for maximal reconvergence.

[luciechoi]

Added 2 tests based on the article, subgroup uniform control flow and loop peeling.

Addresses llvm/llvm-project#136930

[luciechoi]

@s-perron @Keenuts

🤔 I don't think the GPUs here have the maximal reconvergence extension Looks all GPUs except for Intel have the extension!

[s-perron]

This is a good couple tests to starts testing convergence. However, the feature checks need to be improved to make sure they run for DirectX as well.

[s-perron]

Looks like Feature/MaximalReconvergence/subgroup_uniform_control_flow.test failing for DirectX in different way.

Intel clang DirectX: Data: [ 8, 9, 8, 9, 14, 7, 7, 7 ]
Intel DXC DirectX: Data: passed
Warp All DirectX: [ 8, 9, 8, 9, 14, 7, 7, 7 ]
MacOS clang: [ 8, 9, 8, 9, 14, 7, 7, 7 ]
MacOS dxc: passed

@spall What is the best way to handle this failure? I'm guessing there are two problems. One in warp and one in the clang compiler.

[spall]

Looks like Feature/MaximalReconvergence/subgroup_uniform_control_flow.test failing for DirectX in different way.

Intel clang DirectX: Data: [ 8, 9, 8, 9, 14, 7, 7, 7 ] Intel DXC DirectX: Data: passed Warp All DirectX: [ 8, 9, 8, 9, 14, 7, 7, 7 ] MacOS clang: [ 8, 9, 8, 9, 14, 7, 7, 7 ] MacOS dxc: passed

@spall What is the best way to handle this failure? I'm guessing there are two problems. One in warp and one in the clang compiler.

so dxc and clang have different results and its determined that the dxc results are correct? Also warp is wrong always? I guess we file an issue on Clang and Warp. @llvm-beanz how should we file an issue on warp for this?

[luciechoi]

	Subgroup Uniform Control Flow	Loop Peeling
windows-intel, check-hlsl-d3d12	✅	✅
windows-intel, check-hlsl-clang-d3d12	[ 8, 9, 8, 9, 14, 7, 7, 7 ]	[ 7, 7, 7, 7, 7, 7, 7, 7 ]
windows-intel, check-hlsl-warp-d3d12	[ 8, 9, 8, 9, 14, 7, 7, 7 ]	✅
windows-intel, check-hlsl-clang-warp-d3d12	[ 8, 9, 8, 9, 14, 7, 7, 7 ]	[ 3, 3, 3, 3, 7, 7, 7, 7 ]
windows-intel, check-hlsl-vk	Unsupported	Unsupported
windows-intel, check-hlsl-clang-vk	Unsupported	Unsupported
windows-qc, check-hlsl-warp-d3d12	[ 8, 9, 8, 9, 14, 7, 7, 7 ]	✅
windows-qc, check-hlsl-clang-warp-d3d12	Build Error	Build Error
macos, check-hlsl-mtl	✅	✅
macos, check-hlsl-clang-mtl	[ 8, 9, 8, 9, 14, 7, 7, 7 ]	[ 7, 7, 7, 7, 7, 7, 7, 7 ]