src/cpu/arm/vm/templateInterpreterGenerator_arm.cpp

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

@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 2008, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 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.

@@ -1238,32 +1238,29 @@
   __ str_32(__ zero_register(Rtemp), Address(R3, JNIHandleBlock::top_offset_in_bytes()));
   if (CheckJNICalls) {
     __ str(__ zero_register(Rtemp), Address(Rthread, JavaThread::pending_jni_exception_check_fn_offset()));
   }
 
-  // Unbox if the result is non-zero object
-#ifdef AARCH64
+  // Unbox oop result, e.g. JNIHandles::resolve result if it's an oop.
   {
-    Label L, Lnull;
+    Label Lnot_oop;
+#ifdef AARCH64
     __ mov_slow(Rtemp, AbstractInterpreter::result_handler(T_OBJECT));
     __ cmp(Rresult_handler, Rtemp);
-    __ b(L, ne);
-    __ cbz(Rsaved_result, Lnull);
-    __ ldr(Rsaved_result, Address(Rsaved_result));
-    __ bind(Lnull);
-    // Store oop on the stack for GC
-    __ str(Rsaved_result, Address(FP, frame::interpreter_frame_oop_temp_offset * wordSize));
-    __ bind(L);
+    __ b(Lnot_oop, ne);
+#else // !AARCH64
+    // For ARM32, Rresult_handler is -1 for oop result, 0 otherwise.
+    __ cbz(Rresult_handler, Lnot_oop);
+#endif // !AARCH64
+    Register value = AARCH64_ONLY(Rsaved_result) NOT_AARCH64(Rsaved_result_lo);
+    __ resolve_jobject(value,   // value
+                       Rtemp,   // tmp1
+                       R1_tmp); // tmp2
+    // Store resolved result in frame for GC visibility.
+    __ str(value, Address(FP, frame::interpreter_frame_oop_temp_offset * wordSize));
+    __ bind(Lnot_oop);
   }
-#else
-  __ tst(Rsaved_result_lo, Rresult_handler);
-  __ ldr(Rsaved_result_lo, Address(Rsaved_result_lo), ne);
-
-  // Store oop on the stack for GC
-  __ cmp(Rresult_handler, 0);
-  __ str(Rsaved_result_lo, Address(FP, frame::interpreter_frame_oop_temp_offset * wordSize), ne);
-#endif // AARCH64
 
 #ifdef AARCH64
   // Restore SP (drop native parameters area), to keep SP in sync with extended_sp in frame
   __ restore_sp_after_call(Rtemp);
   __ check_stack_top();