On Tue, 9 Sep 2025 08:38:06 GMT, Tobias Hartmann <[email protected]> wrote:
> In some benchmarks we hit an endless deopt/recompilation cycle because of > this bailout in C2 when we compile a method with an unloaded return type: > https://github.com/openjdk/valhalla/blob/858be30119bd5bc37a69d16042523f53bea71a36/src/hotspot/share/ci/ciTypeFlow.cpp#L766-L772 > > It's a regression / limitation from > [JDK-8301007](https://bugs.openjdk.org/browse/JDK-8301007) that I had planned > to fix later with [JDK-8284443](https://bugs.openjdk.org/browse/JDK-8284443) > because I thought it wouldn't have an impact on performance. Turns out it > does, so I'll fix it with this issue similar to what we do in > `PhaseMacroExpand::expand_mh_intrinsic_return`. > > For testing, I added a new `PreloadClasses` debug flag that's enabled by > default. Disabling it will disable preloading of all classes from the > LoadableDescriptors attributes. Running testing with this caught some more > issues that I fixed in this PR as well. I'll add it to our (internal) stress > testing job separately. > > I also fixed some inconsistency in the preload logging and adjusted the > corresponding tests. > > Thanks, > Tobias This pull request has now been integrated. Changeset: 9014ec21 Author: Tobias Hartmann <[email protected]> URL: https://git.openjdk.org/valhalla/commit/9014ec219423a83cf1fb63c496b86fca05c40a8f Stats: 319 lines in 27 files changed: 207 ins; 18 del; 94 mod 8366973: [lworld] Deopt/recompilation cycle due to call to method with unloaded return type ------------- PR: https://git.openjdk.org/valhalla/pull/1554
