On Wed, 28 Jun 2023 17:06:56 GMT, 温绍锦 <d...@openjdk.org> wrote:
> Speed up Integer.toString with a precomputed cache array of length 1000, use > division by 1000, so that each iteration can calculate three digits. > > this optimization can also be used in StringBuilder#appent(int) and > Long#toString. > > # Benchmark Result > > > make test TEST="micro:java.lang.Integers.toString*" > > > ## > [aliyun_ecs_c8i.xlarge](https://help.aliyun.com/document_detail/25378.html#c8i) > * cpu : intel xeon sapphire rapids (x64) > ``` diff > -Benchmark (size) Mode Cnt Score Error Units (baseline) > -Integers.toStringBig 500 avgt 15 6.811 ± 0.016 us/op > -Integers.toStringSmall 500 avgt 15 4.794 ± 0.011 us/op > -Integers.toStringTiny 500 avgt 15 3.752 ± 0.065 us/op > > +Benchmark (size) Mode Cnt Score Error Units (PR) > +Integers.toStringBig 500 avgt 15 5.164 ± 0.052 us/op +31.89% > +Integers.toStringSmall 500 avgt 15 3.844 ± 0.025 us/op +24.71% > +Integers.toStringTiny 500 avgt 15 3.453 ± 0.027 us/op +8.65% > > > ### > [aliyun_ecs_c8a.xlarge](https://help.aliyun.com/document_detail/25378.html#c8a) > * cpu : amd epc genoa (x64) > ``` diff > -Benchmark (size) Mode Cnt Score Error Units (baseline) > -Integers.toStringBig 500 avgt 15 6.762 ± 0.018 us/op > -Integers.toStringSmall 500 avgt 15 4.481 ± 0.004 us/op > -Integers.toStringTiny 500 avgt 15 2.761 ± 0.012 us/op > > +Benchmark (size) Mode Cnt Score Error Units (PR) > +Integers.toStringBig 500 avgt 15 5.063 ± 0.175 us/op +33.55% > +Integers.toStringSmall 500 avgt 15 3.498 ± 0.123 us/op +28.10% > +Integers.toStringTiny 500 avgt 15 2.743 ± 0.147 us/op +0.65% > > > ## > [aliyun_ecs_c8y.xlarge](https://help.aliyun.com/document_detail/25378.html#c8y) > * cpu : aliyun yitian 710 (aarch64) > ``` diff > -Benchmark (size) Mode Cnt Score Error Units (baseline) > -Integers.toStringBig 500 avgt 15 12.081 ± 0.377 us/op > -Integers.toStringSmall 500 avgt 15 7.119 ± 0.177 us/op > -Integers.toStringTiny 500 avgt 15 6.323 ± 0.239 us/op > > +Benchmark (size) Mode Cnt Score Error Units (PR) > +Integers.toStringBig 500 avgt 15 8.157 ± 0.274 us/op +48.10% > +Integers.toStringSmall 500 avgt 15 7.207 ± 0.330 us/op -1.22% > +Integers.toStringTiny 500 avgt 15 6.912 ± 0.199 us/op -8.52% Although this method is `IntrinsicCandidate`, in reality it will only be optimized in the fluent-chain of `StringBuilder`/`StringBuffer`, so optimizing its Java implementation is meaningful. ------------- PR Comment: https://git.openjdk.org/jdk/pull/14699#issuecomment-1611961052
