On Sun, 5 Jan 2025 11:01:18 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: > > vector digit2 The performance is improved again by calculating two characters at a time in the DecimalDigit::digit2 method. The performance numbers are as follows: ## 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 f97093d324fbb7de322c86d52db11cafcff2de87 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 (master 5bb9644) -Longs.parseLong 500 avgt 15 3.539 ± 0.031 us/op -Integers.parseInt 500 avgt 15 3.270 ± 0.028 us/op +Benchmark (size) Mode Cnt Score Error Units (current f97093d) +Longs.parseLong 500 avgt 15 3.029 ± 0.033 us/op +16.83% +Integers.parseInt 500 avgt 15 3.120 ± 0.004 us/op +4.80% ## 3. aliyun_ecs_c8i_x64 (CPU Intel®Xeon®Emerald Rapids) -Benchmark (size) Mode Cnt Score Error Units (master 5bb9644) -Longs.parseLong 500 avgt 15 3.469 ± 0.011 us/op -Integers.parseInt 500 avgt 15 3.136 ± 0.005 us/op +Benchmark (size) Mode Cnt Score Error Units (current f97093d) +Longs.parseLong 500 avgt 15 2.999 ± 0.024 us/op +15.67% +Integers.parseInt 500 avgt 15 2.819 ± 0.004 us/op +11.24% ## 4. orange_pi5_aarch64 (CPU RK3588S) -Benchmark (size) Mode Cnt Score Error Units (master 5bb9644) -Longs.parseLong 500 avgt 15 9.903 ± 0.064 us/op -Integers.parseInt 500 avgt 15 9.527 ± 0.678 us/op +Benchmark (size) Mode Cnt Score Error Units (current f97093d) +Longs.parseLong 500 avgt 15 8.702 ± 1.287 us/op +13.80% +Integers.parseInt 500 avgt 15 6.117 ± 0.046 us/op +55.74% # 5. MacBook M1 Pro (aarch64) -Benchmark (size) Mode Cnt Score Error Units (master 5bb9644) -Longs.parseLong 500 avgt 15 2.617 ? 0.040 us/op -Integers.parseInt 500 avgt 15 2.344 ? 0.027 us/op +Benchmark (size) Mode Cnt Score Error Units (current f97093d) +Longs.parseLong 500 avgt 15 2.262 ? 0.014 us/op +15.69% +Integers.parseInt 500 avgt 15 2.033 ? 0.007 us/op +15.29% ------------- PR Comment: https://git.openjdk.org/jdk/pull/22919#issuecomment-2571595624
