[lworld] RFR: 8336845: [lworld] Virtual threads don't support the value class calling convention

[Coleen Phillimore]

On Thu, 11 Sep 2025 14:26:08 GMT, Patricio Chilano Mateo <pchilanomate at openjdk.org> wrote:

>> src/hotspot/cpu/x86/stackChunkFrameStream_x86.inline.hpp line 54:
>> 
>>> 52:                         RegisterMap::WalkContinuation::skip);
>>> 53:         frame caller = to_frame().sender(&map);
>>> 54:         assert(caller.is_compiled_frame() && caller.cb()->as_nmethod()->is_compiled_by_c2(), "");
>> 
>> All these asserts with no messages could be precond().  Or they could have strings why these conditions are expected.
>
> If the c2 frame needs stack repair but was not extended, then caller should be c2 compiled too, i.e. there was no need to extend it. How about adding "needs stack repair but was not extended with c1/interpreter caller"?

I think that sounds good.  The strings in these asserts (there are a few that you added) might help with understanding this code.

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PR Review Comment: https://git.openjdk.org/valhalla/pull/1556#discussion_r2342112498