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

[Roland Westrelin]

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.