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
Materialize the pointer to the polling page in a register instead of using rip-relative addressing when the distance from the code cache is larger than disp32.
Reviewed-by: never, kvn
Copy small (<8) strings on stack if str+16 crosses a page boundary and load from stack into XMM. Back up pointer when loading string's tail.
Reviewed-by: never
Track allocated bytes in Thread's, update on TLAB retirement and direct allocation in Eden and tenured, add JNI methods for ThreadMXBean.
Reviewed-by: coleenp, kvn, dholmes, ysr
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
Incorrect code was being generated for the store operation in the null case of the aastore bytecode template. The bad code was generated by the store_heap_oop routine which takes a Register as its second argument. Passing NULL_WORD (0) as the second argument causes the value to be converted to Register(0), which is rax. Thus the generated store was "mov (dst), $rax" instead of "mov (dst), $0x0". Changed calls to store_heap_oop that pass NULL_WORD as the second argument to a new routine store_heap_oop_null.
Reviewed-by: kvn, twisti
6875866: Intrinsic for String.indexOf() is broken on x86 with SSE4.2
Modify String intrinsic methods to pass char[] pointers instead of string oops.
Reviewed-by: never
Use zero based compressed oops if java heap is below 32gb and unscaled compressed oops if java heap is below 4gb.
Reviewed-by: never, twisti, jcoomes, coleenp
Add a LoadUB (unsigned byte) and LoadUI (unsigned int) opcode class so we have these load optimizations in the first place and do not need to handle them in the matcher.
Reviewed-by: never, kvn
