Tom Rodriguez

Are the gate failures actual problems? It would be good to see a clean gate. Also, we should squash the history before committing.

Yes this is something I mentioned in our slack discussions. Moving `WriteBarrierAdditionPhase` after `LowTierLoweringPhase` creates problems for GCs that still use snippets since they expect to be lowered by LowTierLoweringPhase....

It would be easy to convert the HotSpot serial barrier to LIR but native image uses snippets for its barriers and its serial barrier is non-trivial. So we'll need to...

Thanks. I'll see whether that works ok in our full gate. I'd tried something slightly different but the `StageFlags` makes it hard to be super flexible about when these phases...

Your fix works though I don't love some of the details. I'll just put comments on those places. I was able to get a clean internal gate with just minor...

Overall I think this looks good. I've only lightly reviewed the actual shenandoah parts since I don't really know anything about how the collector works. A high level JavaDoc comment...

I've started doing some gate testing and found one problem. ``` mx benchmark renaissance:finagle-http -- -XX:+UseShenandoahGC -Xmx8g ``` throws a lot of exceptions like this and never completes ``` [finagle/netty4-2-23]...

`mx unittest -XX:+UseShenandoahGC jdk.graal.compiler.hotspot.test.GCBarrierEmissionTest` shows several problems. On aarch there's a cbnz with size 8 but it should be 32 I think. ``` java.lang.AssertionError: 8 at jdk.graal.compiler/jdk.graal.compiler.asm.aarch64.AArch64MacroAssembler.cbnz(AArch64MacroAssembler.java:1768) at jdk.graal.compiler/jdk.graal.compiler.hotspot.aarch64.shenandoah.AArch64HotSpotShenandoahLoadRefBarrierOp.lambda$emitCode$0(AArch64HotSpotShenandoahLoadRefBarrierOp.java:192) at...

One ugly missing piece is support for the fast truffle dispatch in the truffle implementation of `EntryPointDecorator.emitEntryPoint`. That code performs an explicit read of an obj in the method prologue...

Thanks for updates. There are various style problems that need to be fixed. Unused imports, guarantee should use `%s` and missing copyrights. This is my script to run the minimal...