RFR: 8286446: PPC64: fix crashes after JDK-8284161 (virtual threads preview)

[Coleen Phillimore]

On Mon, 9 May 2022 22:45:49 GMT, Richard Reingruber <rrich at openjdk.org> wrote:

> With this change `java -version` succeeds with the devkit build also the standard build on a ppc64le box does not crash anymore.
> 
> Also tier1 tests don't look too bad.

Thanks for fixing PPC.  The changes look like the riscv ones.

src/hotspot/cpu/ppc/stubGenerator_ppc.cpp line 4545:

> 4543: 
> 4544:     address start = __ pc();
> 4545:     __ unimplemented(FILE_AND_LINE);

If this is going to call unimplemented(), you might have to not define JFR_HAVE_INTRINSICS for PPC.

src/hotspot/cpu/ppc/stubGenerator_ppc.cpp line 4701:

> 4699:     } else {
> 4700:       generate_all();
> 4701:     }

Does this fix this assert?
        # guarantee(_table_length < _table_max_length) failed: Incorrect UnsafeCopyMemory::_table_max_length
I tried to trace through source code to see why and failed to do so.

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Marked as reviewed by coleenp (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/8617