On Wed, 15 Mar 2023 12:28:05 GMT, Eirik Bjorsnos <d...@openjdk.org> wrote:
>>> `if (ch && 0xFFFFFF00 == 0) {`
>>
>> This seems to perform similar to baseline:
>>
>>
>> Benchmark (codePoint) Mode Cnt Score Error Units
>> Characters.isDigit 48 avgt 15 0.890 ± 0.025 ns/op
>> Characters.isDigit 1632 avgt 15 2.174 ± 0.011 ns/op
>>
>>
>> Would be interesting to check the performance on non-Intel architectures. If
>> you want to give it a spin on your M1, here's the benchmark command I used:
>>
>> `make test TEST='micro:java.lang.Characters.isDigit' MICRO="OPTIONS=-p
>> codePoint=48,1632"`
>
>> It seems reasonable to keep these two in sync, yes. (`CharacterData.of`
>> could even call into `StringLatin1.canEncode`, unless that's cause for some
>> performance anomaly)
>
> If I update `StringLatin1.canEncode` and call into that from
> `CharacterData.of`, I observe no regression for the Latin1 case, but a
> significant regression for the non-Latin1 case. I have no idea how to explain
> that:
>
>
> Benchmark (codePoint) Mode Cnt Score Error Units
> Characters.isDigit 48 avgt 15 0.675 ± 0.029 ns/op
> Characters.isDigit 1632 avgt 15 2.435 ± 0.032 ns/op
Can you check what happen adding much more inputs to the dataset that includes
non-latin chars as well and use `-prof perfnorm` to check what `perf` report re
branches/branch-misses?
You can use SplittableRandom to pre-populate an array of inputs which sequence
is "random" but still allow deterministic benchmarking and feed the benchmark
method cycling the pre-computed inputs
-------------
PR: https://git.openjdk.org/jdk/pull/13040
