RFR: 8331558: AArch64: optimize integer remainder
Jin Guojie
duke at openjdk.org
Thu May 30 05:37:30 UTC 2024
On some Arm processors, a separate multiply/subtract is actually faster than the combined instruction.
(1) The following test has passed, which shows performance improvement.
make test TEST="micro:java.lang.IntegerDivMod"
make test TEST="micro:java.lang.LongDivMod"
* IntegerDivMod.testDivideRemainderUnsigned baseline(ns/ops) 2223 with this pacth(ns/ops) 1885 improvement(%) 17.93%
* IntegerDivMod.testRemainderUnsigned baseline(ns/ops) 2225 with this pacth(ns/ops) 1885 improvement(%) 18.03%
* LongDivMod.testDivideRemainderUnsigned baseline(ns/ops) 2231 with this pacth(ns/ops) 1894 improvement(%) 17.79%
* LongDivMod.testRemainderUnsigned baseline(ns/ops) 2232 with this pacth(ns/ops) 1891 improvement(%) 18.03%
(2) jtreg test has passed
make run-test TEST=tier1
-------------
Commit messages:
- 8331558: AArch64: optimize integer remainder
Changes: https://git.openjdk.org/jdk/pull/19471/files
Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=19471&range=00
Issue: https://bugs.openjdk.org/browse/JDK-8331558
Stats: 73 lines in 4 files changed: 58 ins; 9 del; 6 mod
Patch: https://git.openjdk.org/jdk/pull/19471.diff
Fetch: git fetch https://git.openjdk.org/jdk.git pull/19471/head:pull/19471
PR: https://git.openjdk.org/jdk/pull/19471
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