CUDA: fix race condition in FA vector kernels #13742
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This reverts commit ffd0eae.
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Fixes #13733 .
Looking at the code I added in #13584 again, I think I accidentally introduced a race condition. The mask is being written to shared memory anyways, so the synchronization between warps is achieved by each warp just checking all of the mask values, and then reducing
skipwithin the warp. Each warp will come to the same conclusion regarding whether or not to execute thecontinue. However, warps are not guaranteed to execute thecontinueat the same time, and after they do they will write new values tomaskf_sharedwhich can in turn influence whether other warps will execute thecontinue, potentially causing the warps to become desynchronized.