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@luciechoi luciechoi commented Oct 17, 2025

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

Addresses llvm/llvm-project#136930

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luciechoi commented Oct 21, 2025

@s-perron @Keenuts

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

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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.

@luciechoi luciechoi force-pushed the maximal_reconvergence branch from 557f48f to 1251f6e Compare October 22, 2025 17:00
@luciechoi luciechoi requested a review from s-perron October 22, 2025 17:02
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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.

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spall commented Oct 23, 2025

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?

Co-authored-by: Steven Perron <stevenperron@google.com>
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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 ]

# XFAIL: Clang && Vulkan

# BUG: https://github.com/llvm/offload-test-suite/issues/490
# XFAIL: DirectX && WARP
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This test works on WARP. It only fails when clang is used.

# XFAIL: DirectX && WARP

# BUG: https://github.com/llvm/llvm-project/issues/165288
# XFAIL: Clang && DirectX
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Looks like clang mtl is failing at well (both tests). It is probably the same issue. XFAIL that one as well.

# XFAIL: DirectX && WARP

# BUG: https://github.com/llvm/llvm-project/issues/165288
# XFAIL: Clang && DirectX
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XFAIL for mtl and clang as well.

@luciechoi luciechoi force-pushed the maximal_reconvergence branch 2 times, most recently from d8b8c05 to 99aac0b Compare October 27, 2025 20:18
@luciechoi luciechoi force-pushed the maximal_reconvergence branch from 99aac0b to dec04ff Compare October 27, 2025 20:21
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