Improve BlockUtil#countUsedPositions #8910
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sopel39
approved these changes
Aug 18, 2021
martint
reviewed
Aug 23, 2021
| if (position) { | ||
| used++; | ||
| } | ||
| // Avoid branching by casting boolean to integer. |
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What evidence do we have that this is from branch mispredictions? Do we have a capture from JMH with the perf profiler that shows this?
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It's similar concept to: #8624
which was giving around 50% improvements in JMH:
Benchmark Mode Cnt Score Error Units
BenchmarkFoo.newPos thrpt 10 96730,342 ± 2154,841 ops/s
BenchmarkFoo.oldPos thrpt 10 50875,222 ± 1058,018 ops/s
I don't think @raunaqmorarka did microbenchmarks on this one though
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Understood, but it’s unclear whether it’s because of branch mispredictions or some other effect.
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Understood, but it’s unclear whether it’s because of branch mispredictions or some other effect.
I didn't look into assembly.
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