RFR: 8347009: Speed up parseInt and parseLong [v13]
Shaojin Wen
swen at openjdk.org
Sat Feb 1 10:07:25 UTC 2025
> 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 29 commits:
- Merge remote-tracking branch 'upstream/master' into optim_parse_int_long_202501
# Conflicts:
# src/java.base/share/classes/jdk/internal/util/DecimalDigits.java
- multiply 10
- copyright
- error message
- Merge remote-tracking branch 'upstream/master' into optim_parse_int_long_202501
# Conflicts:
# src/java.base/share/classes/jdk/internal/util/DecimalDigits.java
- use &
- from @rgiulietti
- remove unused
- Update src/java.base/share/classes/jdk/internal/util/DecimalDigits.java
Co-authored-by: Chen Liang <liach at openjdk.org>
- vector digit2
- ... and 19 more: https://git.openjdk.org/jdk/compare/651ac3cc...1fb40bb9
-------------
Changes: https://git.openjdk.org/jdk/pull/22919/files
Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22919&range=12
Stats: 196 lines in 5 files changed: 116 ins; 26 del; 54 mod
Patch: https://git.openjdk.org/jdk/pull/22919.diff
Fetch: git fetch https://git.openjdk.org/jdk.git pull/22919/head:pull/22919
PR: https://git.openjdk.org/jdk/pull/22919
More information about the core-libs-dev
mailing list