estewart08 added a comment. In D99432#2726391 <https://reviews.llvm.org/D99432#2726391>, @ABataev wrote:
> In D99432#2726337 <https://reviews.llvm.org/D99432#2726337>, @estewart08 > wrote: > >> In D99432#2726060 <https://reviews.llvm.org/D99432#2726060>, @ABataev wrote: >> >>> In D99432#2726050 <https://reviews.llvm.org/D99432#2726050>, @estewart08 >>> wrote: >>> >>>> In D99432#2726025 <https://reviews.llvm.org/D99432#2726025>, @ABataev >>>> wrote: >>>> >>>>> In D99432#2726019 <https://reviews.llvm.org/D99432#2726019>, @estewart08 >>>>> wrote: >>>>> >>>>>> In reference to https://bugs.llvm.org/show_bug.cgi?id=48851, I do not >>>>>> see how this helps SPMD mode with team privatization of declarations >>>>>> in-between target teams and parallel regions. >>>>> >>>>> DiŠ² you try the reproducer with the applied patch? >>>> >>>> Yes, I still saw the test fail, although it was not with latest >>>> llvm-project. Are you saying the reproducer passes for you? >>> >>> I don't have CUDA installed but from what I see in the LLVM IR it shall >>> pass. Do you have a debug log, does it crashes or produces incorrect >>> results? >> >> This is on an AMDGPU but I assume the behavior would be similar for NVPTX. >> >> It produces incorrect/incomplete results in the dist[0] index after a manual >> reduction and in turn the final global gpu_results array is incorrect. >> When thread 0 does a reduction into dist[0] it has no knowledge of dist[1] >> having been updated by thread 1. Which tells me the array is still thread >> private. >> Adding some printfs, looking at one teams' output: >> >> SPMD >> >> Thread 0: dist[0]: 1 >> Thread 0: dist[1]: 0 // This should be 1 >> After reduction into dist[0]: 1 // This should be 2 >> gpu_results = [1,1] // [2,2] expected >> >> Generic Mode: >> >> Thread 0: dist[0]: 1 >> Thread 0: dist[1]: 1 >> After reduction into dist[0]: 2 >> gpu_results = [2,2] > > Hmm, I would expect a crash if the array was allocated in the local memory. > Could you try to add some more printfs (with data and addresses of the array) > to check the results? Maybe there is a data race somewhere in the code? As a reminder, each thread updates a unique index in the dist array and each team updates a unique index in gpu_results. SPMD - shows each thread has a unique address for dist array Team 0 Thread 1: dist[0]: 0, 0x7f92e24a8bf8 Team 0 Thread 1: dist[1]: 1, 0x7f92e24a8bfc Team 0 Thread 0: dist[0]: 1, 0x7f92e24a8bf0 Team 0 Thread 0: dist[1]: 0, 0x7f92e24a8bf4 Team 0 Thread 0: After reduction into dist[0]: 1 Team 0 Thread 0: gpu_results address: 0x7f92a5000000 -------------------------------------------------- Team 1 Thread 1: dist[0]: 0, 0x7f92f9ec5188 Team 1 Thread 1: dist[1]: 1, 0x7f92f9ec518c Team 1 Thread 0: dist[0]: 1, 0x7f92f9ec5180 Team 1 Thread 0: dist[1]: 0, 0x7f92f9ec5184 Team 1 Thread 0: After reduction into dist[0]: 1 Team 1 Thread 0: gpu_results address: 0x7f92a5000000 gpu_results[0]: 1 gpu_results[1]: 1 Generic - shows each team shares dist array address amongst threads Team 0 Thread 1: dist[0]: 1, 0x7fac01938880 Team 0 Thread 1: dist[1]: 1, 0x7fac01938884 Team 0 Thread 0: dist[0]: 1, 0x7fac01938880 Team 0 Thread 0: dist[1]: 1, 0x7fac01938884 Team 0 Thread 0: After reduction into dist[0]: 2 Team 0 Thread 0: gpu_results address: 0x7fabc5000000 -------------------------------------------------- Team 1 Thread 1: dist[0]: 1, 0x7fac19354e10 Team 1 Thread 1: dist[1]: 1, 0x7fac19354e14 Team 1 Thread 0: dist[0]: 1, 0x7fac19354e10 Team 1 Thread 0: dist[1]: 1, 0x7fac19354e14 Team 1 Thread 0: After reduction into dist[0]: 2 Team 1 Thread 0: gpu_results address: 0x7fabc5000000 Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D99432/new/ https://reviews.llvm.org/D99432 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
