RFR: 8347009: Speed up parseInt and parseLong [v25]
Shaojin Wen
swen at openjdk.org
Thu Jan 22 01:31:27 UTC 2026
> 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 44 commits:
- Merge branch 'master' into optim_parse_int_long_202501
- remove unsafe
- Merge remote-tracking branch 'upstream/master' into optim_parse_int_long_202501
- Merge remote-tracking branch 'origin/optim_parse_int_long_202501' into optim_parse_int_long_202501
- 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
- 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
- remove ForceInline
- fix comments
- fix comments
- ... and 34 more: https://git.openjdk.org/jdk/compare/a0ac5b34...90778ed9
-------------
Changes: https://git.openjdk.org/jdk/pull/22919/files
Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22919&range=24
Stats: 146 lines in 6 files changed: 68 ins; 26 del; 52 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
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