RFR(M): 8210887: Tweak C2 gc api for arraycopy

[Vladimir Kozlov]

gc/epsilon/TestManyThreads.java test failed on SPARC
I add information and replay file to bug report.

Vladimir

On 9/27/18 6:58 AM, Roland Westrelin wrote:
> 
> Hi Vladimir,
> 
> Thanks for the review and the testing.
> 
>> A LOT tests failed.
> 
> I did some last minute code refactoring after running tests and managed
> to break something. Sorry about that.
> 
> The fix is:
> 
> diff --git a/src/hotspot/share/gc/shared/c2/barrierSetC2.cpp b/src/hotspot/share/gc/shared/c2/barrierSetC2.cpp
> --- a/src/hotspot/share/gc/shared/c2/barrierSetC2.cpp
> +++ b/src/hotspot/share/gc/shared/c2/barrierSetC2.cpp
> @@ -598,6 +598,7 @@
>     ac->set_clonebasic();
>     Node* n = kit->gvn().transform(ac);
>     if (n == ac) {
> +    ac->_adr_type = TypeRawPtr::BOTTOM;
>       kit->set_predefined_output_for_runtime_call(ac, ac->in(TypeFunc::Memory), raw_adr_type);
>     } else {
>       kit->set_all_memory(n);
> 
> 
> New webrev:
> 
> http://cr.openjdk.java.net/~roland/8210887/webrev.01/
> 
> Roland.
>