src/share/vm/gc_implementation/g1/g1ParScanThreadState.inline.hpp

rev 7471 : 8060025: Object copy time regressions after JDK-8031323 and JDK-8057536
Summary: Evaluate and improve object copy time by micro-optimizations and splitting out slow and fast paths aggressively.
Reviewed-by:
Contributed-by: Tony Printezis <tprintezis@twitter.com>, Thomas Schatzl <thomas.schatzl@oracle.com>

*** 36,60 ****
  
    // Although we never intentionally push references outside of the collection
    // set, due to (benign) races in the claim mechanism during RSet scanning more
    // than one thread might claim the same card. So the same card may be
    // processed multiple times. So redo this check.
!   G1CollectedHeap::in_cset_state_t in_cset_state = _g1h->in_cset_state(obj);
!   if (in_cset_state == G1CollectedHeap::InCSet) {
      oop forwardee;
      markOop m = obj->mark();
      if (m->is_marked()) {
        forwardee = (oop) m->decode_pointer();
      } else {
!       forwardee = copy_to_survivor_space(obj, m);
      }
      oopDesc::encode_store_heap_oop(p, forwardee);
!   } else if (in_cset_state == G1CollectedHeap::IsHumongous) {
      _g1h->set_humongous_is_live(obj);
    } else {
!     assert(in_cset_state == G1CollectedHeap::InNeither,
!            err_msg("In_cset_state must be InNeither here, but is %d", in_cset_state));
    }
  
    assert(obj != NULL, "Must be");
    update_rs(from, p, queue_num());
  }
--- 36,60 ----
  
    // Although we never intentionally push references outside of the collection
    // set, due to (benign) races in the claim mechanism during RSet scanning more
    // than one thread might claim the same card. So the same card may be
    // processed multiple times. So redo this check.
!   const in_cset_state_t in_cset_state = _g1h->in_cset_state(obj);
!   if (InCSetState::is_in_cset(in_cset_state)) {
      oop forwardee;
      markOop m = obj->mark();
      if (m->is_marked()) {
        forwardee = (oop) m->decode_pointer();
      } else {
!       forwardee = copy_to_survivor_space(in_cset_state, obj, m);
      }
      oopDesc::encode_store_heap_oop(p, forwardee);
!   } else if (InCSetState::is_humongous(in_cset_state)) {
      _g1h->set_humongous_is_live(obj);
    } else {
!     assert(InCSetState::is_not_in_cset(in_cset_state),
!            err_msg("In_cset_state must be NotInCSet here, but is %d", in_cset_state));
    }
  
    assert(obj != NULL, "Must be");
    update_rs(from, p, queue_num());
  }