On Fri, 14 May 2021 07:14:27 GMT, Laurent Bourgès <lbour...@openjdk.org> wrote:
>> So the issue of not skipping passes was my fault in the translation process, >> so not something to worry about, though after [fixing >> that](https://github.com/richardstartin/radix-sort-benchmark/commit/ccbee984c6a0e0f50c30de59e1a5e9fbcad89510) >> the original implementation still has the edge because of the bounds checks >> on the `xor` not getting eliminated. >> >> >> Benchmark (bits) (padding) >> (scenario) (seed) (size) Mode Cnt Score Error Units >> RadixSortBenchmark.jdk 17 7 >> UNIFORM 0 1000000 avgt 5 10432.408 ± 87.024 us/op >> RadixSortBenchmark.jdk 23 7 >> UNIFORM 0 1000000 avgt 5 9465.990 ± 40.598 us/op >> RadixSortBenchmark.jdk 30 7 >> UNIFORM 0 1000000 avgt 5 11189.146 ± 50.972 us/op >> RadixSortBenchmark.unrollOnePassSkipLevelsSigned 17 7 >> UNIFORM 0 1000000 avgt 5 9546.963 ± 41.698 us/op >> RadixSortBenchmark.unrollOnePassSkipLevelsSigned 23 7 >> UNIFORM 0 1000000 avgt 5 9412.114 ± 43.081 us/op >> RadixSortBenchmark.unrollOnePassSkipLevelsSigned 30 7 >> UNIFORM 0 1000000 avgt 5 10823.618 ± 64.311 us/op > > Great analysis on C2, richard. > > maybe (x ^ 0x80) &0xFF would help C2 to eliminate bound checks... I don't know Laurent, I find the handling of signed order over-complicated. Subtracting `Integer.MIN_VALUE` is really cheap... ------------- PR: https://git.openjdk.java.net/jdk/pull/3938
