--- a/hotspot/src/cpu/sparc/vm/templateInterpreter_sparc.cpp	Tue Apr 05 19:14:03 2011 -0700
+++ b/hotspot/src/cpu/sparc/vm/templateInterpreter_sparc.cpp	Thu Apr 07 09:53:20 2011 -0700
@@ -763,6 +763,87 @@
   return NULL;
 }
 
+// Method entry for java.lang.ref.Reference.get.
+address InterpreterGenerator::generate_Reference_get_entry(void) {
+#ifndef SERIALGC
+  // Code: _aload_0, _getfield, _areturn
+  // parameter size = 1
+  //
+  // The code that gets generated by this routine is split into 2 parts:
+  //    1. The "intrinsified" code for G1 (or any SATB based GC),
+  //    2. The slow path - which is an expansion of the regular method entry.
+  //
+  // Notes:-
+  // * In the G1 code we do not check whether we need to block for
+  //   a safepoint. If G1 is enabled then we must execute the specialized
+  //   code for Reference.get (except when the Reference object is null)
+  //   so that we can log the value in the referent field with an SATB
+  //   update buffer.
+  //   If the code for the getfield template is modified so that the
+  //   G1 pre-barrier code is executed when the current method is
+  //   Reference.get() then going through the normal method entry
+  //   will be fine.
+  // * The G1 code can, however, check the receiver object (the instance
+  //   of java.lang.Reference) and jump to the slow path if null. If the
+  //   Reference object is null then we obviously cannot fetch the referent
+  //   and so we don't need to call the G1 pre-barrier. Thus we can use the
+  //   regular method entry code to generate the NPE.
+  //
+  // This code is based on generate_accessor_enty.
+
+  address entry = __ pc();
+
+  const int referent_offset = java_lang_ref_Reference::referent_offset;
+  guarantee(referent_offset > 0, "referent offset not initialized");
+
+  if (UseG1GC) {
+     Label slow_path;
+
+    // In the G1 code we don't check if we need to reach a safepoint. We
+    // continue and the thread will safepoint at the next bytecode dispatch.
+
+    // Check if local 0 != NULL
+    // If the receiver is null then it is OK to jump to the slow path.
+    __ ld_ptr(Gargs, G0, Otos_i ); // get local 0
+    __ tst(Otos_i);  // check if local 0 == NULL and go the slow path
+    __ brx(Assembler::zero, false, Assembler::pn, slow_path);
+    __ delayed()->nop();
+
+
+    // Load the value of the referent field.
+    if (Assembler::is_simm13(referent_offset)) {
+      __ load_heap_oop(Otos_i, referent_offset, Otos_i);
+    } else {
+      __ set(referent_offset, G3_scratch);
+      __ load_heap_oop(Otos_i, G3_scratch, Otos_i);
+    }
+
+    // Generate the G1 pre-barrier code to log the value of
+    // the referent field in an SATB buffer. Note with
+    // these parameters the pre-barrier does not generate
+    // the load of the previous value
+
+    __ g1_write_barrier_pre(noreg /* obj */, noreg /* index */, 0 /* offset */,
+                            Otos_i /* pre_val */,
+                            G3_scratch /* tmp */,
+                            true /* preserve_o_regs */);
+
+    // _areturn
+    __ retl();                      // return from leaf routine
+    __ delayed()->mov(O5_savedSP, SP);
+
+    // Generate regular method entry
+    __ bind(slow_path);
+    (void) generate_normal_entry(false);
+    return entry;
+  }
+#endif // SERIALGC
+
+  // If G1 is not enabled then attempt to go through the accessor entry point
+  // Reference.get is an accessor
+  return generate_accessor_entry();
+}
+
 //
 // Interpreter stub for calling a native method. (asm interpreter)
 // This sets up a somewhat different looking stack for calling the native method