On Thu, 18 Dec 2025 07:31:30 GMT, Tobias Hartmann <[email protected]> wrote:
> C2 will now remove the slow call to > `ValueObjectMethods::isSubstitutable(Alt)` whenever it's able to determine > the layout of one of the operands. It will then emit code to directly compare > the fields. > > This patch also contains an intrinsic for `_getFieldMap` that will be used by > the new core-libs implementation of the substitutability check > ([JDK-8370450](https://bugs.openjdk.org/browse/JDK-8370450)) that's used by > the interpreter / C1 and as a slow path in C2. > > When browsing code, I marked a few rough edges in unrelated code for > follow-up cleanups with the corresponding bug numbers. > > Testing: tier1-tier6 + valhalla-comp-stress > > Thanks, > Tobias This pull request has now been integrated. Changeset: b63e3bef Author: Tobias Hartmann <[email protected]> URL: https://git.openjdk.org/valhalla/commit/b63e3bef28559b26360b8bce2a90322a1fddcc85 Stats: 1506 lines in 30 files changed: 1269 ins; 106 del; 131 mod 8228361: [lworld] Optimize the substitutability check in C2 Reviewed-by: chagedorn, mhaessig ------------- PR: https://git.openjdk.org/valhalla/pull/1823
