RFR: 8347009: Speed ​​up parseInt and parseLong [v21]

[Shaojin Wen]

On Fri, 2 May 2025 03:53:23 GMT, Shaojin Wen <swen at 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 with a new target base due to a merge or a rebase. The pull request now contains 39 commits:
> 
>  - Merge remote-tracking branch 'upstream/master' into optim_parse_int_long_202501
>    
>    # Conflicts:
>    #	src/java.base/share/classes/java/lang/Integer.java
>    #	src/java.base/share/classes/java/lang/Long.java
>  - Merge remote-tracking branch 'upstream/master' into optim_parse_int_long_202501
>  - remove ForceInline
>  - fix comments
>  - fix comments
>  - Update src/java.base/share/classes/jdk/internal/util/DecimalDigits.java
>    
>    Co-authored-by: Raffaello Giulietti <raffaello.giulietti at oracle.com>
>  - copyright
>  - fix JdbExprTest
>  - Update src/java.base/share/classes/java/lang/Long.java
>    
>    Co-authored-by: Raffaello Giulietti <raffaello.giulietti at oracle.com>
>  - Update src/java.base/share/classes/java/lang/Integer.java
>    
>    Co-authored-by: Raffaello Giulietti <raffaello.giulietti at oracle.com>
>  - ... and 29 more: https://git.openjdk.org/jdk/compare/bd7c7789...047e1709

keep alive

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PR Comment: https://git.openjdk.org/jdk/pull/22919#issuecomment-2957461147