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
src/java.base/share/classes/java/lang/Integer.java line 581:
> 579: }
> 580:
> 581: static boolean isDigitLatin2(int ch) {
Unused, should be removed
src/java.base/share/classes/jdk/internal/util/DecimalDigits.java line 154:
> 152: Here we are doing a 2-Byte Vector operation on the short
> type.
> 153:
> 154: x & 0xF0 != 0xC0
Suggestion:
x & 0xF0 != 0x30
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/22919#discussion_r1915043154
PR Review Comment: https://git.openjdk.org/jdk/pull/22919#discussion_r1915038981
