--- old/src/share/vm/opto/compile.cpp 2011-03-28 10:10:25.663475000 -0700 +++ new/src/share/vm/opto/compile.cpp 2011-03-28 10:10:25.436774000 -0700 @@ -629,7 +629,7 @@ initial_gvn()->transform_no_reclaim(top()); // Set up tf(), start(), and find a CallGenerator. - CallGenerator* cg; + CallGenerator* cg = NULL; if (is_osr_compilation()) { const TypeTuple *domain = StartOSRNode::osr_domain(); const TypeTuple *range = TypeTuple::make_range(method()->signature()); @@ -644,9 +644,24 @@ StartNode* s = new (this, 2) StartNode(root(), tf()->domain()); initial_gvn()->set_type_bottom(s); init_start(s); - float past_uses = method()->interpreter_invocation_count(); - float expected_uses = past_uses; - cg = CallGenerator::for_inline(method(), expected_uses); + if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) { + // With java.lang.ref.reference.get() we must go through the + // intrinsic when G1 is enabled - even when get() is the root + // method of the compile - so that, if necessary, the value in + // the referent field of the reference object gets recorded by + // the pre-barrier code. + // Specifically, if G1 is enabled, the value in the referent + // field is recorded by the G1 SATB pre barrier. This will + // result in the referent being marked live and the reference + // object removed from the list of discovered references during + // reference processing. + cg = find_intrinsic(method(), false); + } + if (cg == NULL) { + float past_uses = method()->interpreter_invocation_count(); + float expected_uses = past_uses; + cg = CallGenerator::for_inline(method(), expected_uses); + } } if (failing()) return; if (cg == NULL) {