A referent object that is only weakly reachable at the start of concurrent marking but is re-attached to the strongly reachable object graph during marking may not be marked as live. This can cause the reference object to be processed prematurely and leave dangling pointers to the referent object. Implement a read barrier for the java.lang.ref.Reference::referent field by intrinsifying the Reference.get() method, and intercepting accesses though JNI, reflection, and Unsafe, so that when a non-null referent object is read it is also logged in an SATB buffer.
Reviewed-by: kvn, iveresov, never, tonyp, dholmes
This change implements compressed oops for C1 for x64 and sparc. The changes are mostly on the codegen level, with a few exceptions when we do access things outside of the heap that are uncompressed from the IR. Compressed oops are now also enabled with tiered.
Reviewed-by: twisti, kvn, never, phh
Fixes an historical oddity in C1 with inlining where all of the expression stacks are kept in the topmost ValueStack instead of being in their respective ValueStacks.
Reviewed-by: never
The Address class on SPARC currently handles both, addresses and address literals, what makes the Address class more complicated than it has to be.
Reviewed-by: never, kvn
