RFR: 8287901: Loom: Failures with -XX:+VerifyStack [v2]

[Coleen Phillimore]

On Wed, 8 Jun 2022 16:30:37 GMT, Ron Pressler <rpressler at openjdk.org> wrote:

>> Please review the following change.
>> 
>> Debugging information added to `frame::describe` (used by `JavaThread::print_frame_layout`) was inaccurate, but proved fatal with `VerifyStack`, which uses the same information for verification.
>> 
>> The location of a caller frame's return address and spilled fp, which are located in the callee, were recorded by the caller frame. In the case of the special frame `Continuation.enterSpecial`, those locations were recorded incorrectly. The fix is to record the information while describing the callee frame, rather than the caller.
>> 
>> Passes tier1
>
> Ron Pressler has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Fix locations for interpreted frames

I have one question about the test.

test/jdk/jdk/internal/vm/Continuation/Basic.java line 50:

> 48: *
> 49: * @run testng/othervm --enable-preview -XX:+VerifyStack -Xint Basic
> 50: * @run testng/othervm --enable-preview -XX:+VerifyStack -Xcomp -XX:TieredStopAtLevel=3 -XX:CompileOnly=jdk/internal/vm/Continuation,Basic Basic

Why 3?  Isn't C1 only equivalent to -XX:TieredStopAtLevel=1 ?

-------------

Marked as reviewed by coleenp (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/9066