Richard Startin prompted me to have a look at a case where java.time underperforms relative to joda time (https://twitter.com/richardstartin/status/1506975932271190017).
It seems the java.time test of his suffer from heavy allocations due ZoneOffset::getRules allocating a new ZoneRules object every time and escape analysis failing to do the thing in his test. The patch here adds a simple specialization so that when creating ZonedDateTimes using a ZoneOffset we don't query the rules at all. This removes the risk of extra allocations and slightly speeds up ZonedDateTime creation for both ZoneOffset (+14%) and ZoneRegion (+5%) even when EA works like it should (the case in the here provided microbenchmark). ------------- Commit messages: - Fix names, typos - Avoid going through ZoneRules for ZoneOffsets Changes: https://git.openjdk.java.net/jdk/pull/7957/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=7957&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8283681 Stats: 126 lines in 5 files changed: 123 ins; 2 del; 1 mod Patch: https://git.openjdk.java.net/jdk/pull/7957.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/7957/head:pull/7957 PR: https://git.openjdk.java.net/jdk/pull/7957
