On Fri, 30 Jun 2023 01:03:30 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 >> >> >> bash configure --with-jmh=build/jmh/jars >> make test TEST="micro:java.lang.Integers.toString*" >> >> >> ## 1. >> [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 Update >> 01 3355d211) >> +Integers.toStringBig 500 avgt 15 5.148 ± 0.044 us/op (+32.30%) >> +Integers.toStringSmall 500 avgt 15 3.820 ± 0.016 us/op (+25.48%) >> +Integers.toStringTiny 500 avgt 15 3.426 ± 0.010 us/op (+9.51%) >> >> +Benchmark (size) Mode Cnt Score Error Units (PR Update >> 02 62b499d6) >> +Integers.toStringBig 500 avgt 15 5.971 ± 0.014 us/op (+14.06%) >> +Integers.toStringSmall 500 avgt 15 4.346 ± 0.016 us/op (+10.30%) >> +Integers.toStringTiny 500 avgt 15 3.671 ± 0.019 us/op (+2.20%) >> >> >> ## 2. >> [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 Update >> 01 3355d211) >> +Integers.toStringBig 500 avgt 15 4.901 ± 0.005 us/op (+37.97%) >> +Integers.toStringSmall 500 avgt 15 3.515 ± 0.204 us/op (+27.48%) >> +Integers.toStringTiny 500 avgt 15 2.698 ± 0.190 us/op (+2.33%) >> >> +Benchmark (size) Mode Cnt Score Error Units (PR Update >> 02 62b499d6) >> +Integers.toStringBig 500 avgt 15 5.493 ± 0.007 us/op (+23.10%) >> +Integers.toStringSmall 500 avgt 15 3.714 ± 0.006 us/op (+20.65%) >> +Integers.toStringTiny 500 avgt 15 2.786 ± 0.015 us/op (-0.89... > > 温绍锦 has updated the pull request incrementally with one additional commit > since the last revision: > > improve based on getChars Changes requested by liach (Author). src/java.base/share/classes/java/lang/Integer.java line 552: > 550: i = q; > 551: charPos -= 2; > 552: Unsafe.getUnsafe().putShortUnaligned(buf, > Unsafe.ARRAY_BYTE_BASE_OFFSET + charPos, DigitPacks[r]); Suggestion: Unsafe.getUnsafe().putShortUnaligned(buf, Unsafe.ARRAY_BYTE_BASE_OFFSET + charPos, DigitPacks[r], false); You should explicitly specify the endianness, which is platform dependent. ------------- PR Review: https://git.openjdk.org/jdk/pull/14699#pullrequestreview-1506384387 PR Review Comment: https://git.openjdk.org/jdk/pull/14699#discussion_r1247350891
