On Sat, 4 Jan 2025 12:09:04 GMT, Shaojin Wen <s...@openjdk.org> wrote:
>> This is an optimization for decimal Integer.parseInt and Long.parseLong, >> which improves performance by about 10%. The optimization includes: >> 1. Improve performance by parsing 2 numbers at a time, which has performance >> improvements for numbers with length >= 3. >> 2. It uses charAt(0) for the first number. Assuming that the optimization >> can eliminate boundary checks, this will be more friendly to parsing numbers >> with length 1. >> 3. It removes the reliance on the Character.digit method and eliminates the >> reliance on the CharacterDataLatin1#DIGITS cache array, which avoids >> performance degradation caused by cache misses. > > Shaojin Wen has updated the pull request incrementally with one additional > commit since the last revision: > > use String::value Below are the performance numbers on each platform ## 1. Script git remote add wenshao g...@github.com:wenshao/jdk.git git fetch wenshao #master git checkout 5bb9644202a8b961faad02439c95a81ca6862168 make test TEST="micro:java.lang.Longs.parseLong" make test TEST="micro:java.lang.Integers.parseInt" # current git checkout 9ea084555792fb3c870f6393ce53873e9bde73e6 make test TEST="micro:java.lang.Longs.parseLong" make test TEST="micro:java.lang.Integers.parseInt" ## 2. aliyun_ecs_c8a_x64 (CPU AMD EPYC™ Genoa) -Benchmark (size) Mode Cnt Score Error Units -Longs.parseLong 500 avgt 15 3.542 ± 0.022 us/op -Integers.parseInt 500 avgt 15 3.269 ± 0.015 us/op +Benchmark (size) Mode Cnt Score Error Units +Longs.parseLong 500 avgt 15 3.240 ± 0.037 us/op +9.32% +Integers.parseInt 500 avgt 15 3.208 ± 0.004 us/op +1.90% ## 3. aliyun_ecs_c8i_x64 (CPU Intel®Xeon®Emerald Rapids) -Benchmark (size) Mode Cnt Score Error Units -Longs.parseLong 500 avgt 15 3.477 ± 0.009 us/op -Integers.parseInt 500 avgt 15 3.138 ± 0.006 us/op +Benchmark (size) Mode Cnt Score Error Units +Longs.parseLong 500 avgt 15 3.023 ± 0.028 us/op +15.01% +Integers.parseInt 500 avgt 15 2.847 ± 0.005 us/op +10.22% ## 4. aliyun_ecs_c8y_aarch64 (CPU Aliyun Yitian 710 ARM) -Benchmark (size) Mode Cnt Score Error Units -Longs.parseLong 500 avgt 15 3.819 ± 0.044 us/op -Integers.parseInt 500 avgt 15 3.639 ± 0.075 us/op +Benchmark (size) Mode Cnt Score Error Units +Longs.parseLong 500 avgt 15 3.347 ± 0.015 us/op +14.10% +Integers.parseInt 500 avgt 15 3.192 ± 0.010 us/op +14.03% ## 5. MacBook M1 Pro (aarch64) -Benchmark (size) Mode Cnt Score Error Units -Longs.parseLong 500 avgt 15 2.608 ? 0.035 us/op -Integers.parseInt 500 avgt 15 2.325 ? 0.005 us/op +Benchmark (size) Mode Cnt Score Error Units +Longs.parseLong 500 avgt 15 2.291 ? 0.018 us/op +13.83% +Integers.parseInt 500 avgt 15 2.079 ? 0.011 us/op +11.83% ------------- PR Comment: https://git.openjdk.org/jdk/pull/22919#issuecomment-2571272942
