src/cpu/x86/vm/sharedRuntime_x86_64.cpp

rev 12692 : 8176100: [REDO][REDO] G1 Needs pre barrier on dereference of weak JNI handles
Reviewed-by:

@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 2003, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2017, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.

@@ -2577,18 +2577,15 @@
     restore_native_result(masm, ret_type, stack_slots);
   }
 
   __ reset_last_Java_frame(false);
 
-  // Unpack oop result
+  // Unbox oop result, e.g. JNIHandles::resolve value.
   if (ret_type == T_OBJECT || ret_type == T_ARRAY) {
-      Label L;
-      __ testptr(rax, rax);
-      __ jcc(Assembler::zero, L);
-      __ movptr(rax, Address(rax, 0));
-      __ bind(L);
-      __ verify_oop(rax);
+    __ resolve_jobject(rax /* value */,
+                       r15_thread /* thread */,
+                       rcx /* tmp */);
   }
 
   if (CheckJNICalls) {
     // clear_pending_jni_exception_check
     __ movptr(Address(r15_thread, JavaThread::pending_jni_exception_check_fn_offset()), NULL_WORD);