Futhark.CodeGen.ImpGen.Kernels.SegGenRed

Our compilation strategy for SegGenRed is based around avoiding bin conflicts. We do this by splitting the input into chunks, and for each chunk computing a single subhistogram. Then we combine the subhistograms using an ordinary segmented reduction (SegRed).

There are some branches around to efficiently handle the case where we use only a single subhistogram (because it's large), so that we respect the asymptotics, and do not copy the destination array.

Documentation

compileSegGenRed :: Pattern ExplicitMemory -> KernelSpace -> [GenReduceOp InKernel] -> Body InKernel -> CallKernelGen ()