Apply cuda::barrier and elect_one feedback#6344
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bernhardmgruber merged 2 commits intoNVIDIA:mainfrom Oct 30, 2025
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bernhardmgruber
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ahendriksen
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| const auto uniform_warp_id = __shfl_sync(~0, warp_id, 0); // broadcast from lane 0 | ||
| return uniform_warp_id == 0 && cuda::ptx::elect_sync(~0); // elect a leader thread among warp 0 | ||
| ), | ||
| (::cuda::device::__cuda_elect_sync_is_not_supported_before_SM_90__(); _CCCL_UNREACHABLE();)); |
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Shouldn't the
return threadIdx.x == 0;
go in the else here?
AFAIK PTX ISA is CTK 12.0. CCCL support 12.0 and up, so there is no need for the __cccl_ptx_isa ifdef.
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Then I would need to add it twice, as else branch of the NV_IF_TARGET and as else branch of the _CCCL_CUDA_COMPILATION() && __cccl_ptx_isa >= 800
Regarding PTX ISA. I don't know whether the clang CUDA versions we test already support __cccl_ptx_isa >= 800
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ok, let's just try
miscco
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This is a follow-up to NVIDIA#6329 after feedback from ahendriksen
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This is a follow-up to #6329 after feedback from @ahendriksen