On Fri, 23 Jan 2026 03:42:47 GMT, Shaojin Wen <[email protected]> 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:
>
> from @liach
src/java.base/share/classes/java/lang/Integer.java line 496:
> 494: }
> 495: int len;
> 496: if ((len = s.length()) == 0) {
`parseInt(s, begiNIndex, endIndex, radix)` already checks for an empty string
and calls `NumberformatException.forInputString("", radix)`
See Integer:555.
src/java.base/share/classes/java/lang/Long.java line 531:
> 529: if ((len = s.length()) == 0) {
> 530: throw NumberFormatException.forInputString(s);
> 531: }
Duplicate check for empty string, already checked in Long:583.
src/java.base/share/classes/java/lang/NumberFormatException.java line 58:
> 56:
> 57: /**
> 58: * Factory method for making a {@code NumberFormatException}
Should document it is for radix = 10.
This method doesn't add much value over calling the version with the radix.
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/22919#discussion_r2729632002
PR Review Comment: https://git.openjdk.org/jdk/pull/22919#discussion_r2729683484
PR Review Comment: https://git.openjdk.org/jdk/pull/22919#discussion_r2729690061
