RFR: 8343745: Only update Last Value Assertion Predicates in Loop Unrolling
Christian Hagedorn
chagedorn at openjdk.org
Fri Nov 8 07:19:16 UTC 2024
(Note: This is a dependent PR on https://github.com/openjdk/jdk/pull/21944 which is fully reviewed but I'd prefer to integrate it on Monday and run again some testing over the weekend)
This is a follow-up feature to https://github.com/openjdk/jdk/pull/21944 which updated Loop Unrolling to use a new predicate visitor and enables this patch.
In Loop Unrolling, we only update the stride and not the init value of a loop. Thus, we actually only require to update the Last Value Assertion Predicates because the Init Value Assertion Predicates do not use `OpaqueLoopStride`. So, we also would not be required to kill the old Init Value Initialized Assertion Predicates. This patch implements that improvement.
To make this work, we need to query the associated `AssertionPredicateType` of an Assertion Predicate which is stored in the `If/RangeCheckNode` (I guess it's okay to have this additional node field in product). This was guarded by `NOT_PRODUCT` before. For this patch, I make this information available in product builds and use it to implement this feature.
Thanks,
Christian
-------------
Depends on: https://git.openjdk.org/jdk/pull/21944
Commit messages:
- 8343745: Only update Last Value Assertion Predicates in Loop Unrolling
Changes: https://git.openjdk.org/jdk/pull/21969/files
Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21969&range=00
Issue: https://bugs.openjdk.org/browse/JDK-8343745
Stats: 101 lines in 7 files changed: 16 ins; 13 del; 72 mod
Patch: https://git.openjdk.org/jdk/pull/21969.diff
Fetch: git fetch https://git.openjdk.org/jdk.git pull/21969/head:pull/21969
PR: https://git.openjdk.org/jdk/pull/21969
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