diff -r b5b3db42efca -r d109bda16490 src/share/vm/c1/c1_LIRGenerator.cpp
--- a/src/share/vm/c1/c1_LIRGenerator.cpp	Tue Mar 29 23:01:10 2016 +0100
+++ b/src/share/vm/c1/c1_LIRGenerator.cpp	Tue Apr 05 08:55:39 2016 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2016, 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
@@ -3646,3 +3646,26 @@
     }
   }
 }
+
+LIR_Opr LIRGenerator::maybe_mask_boolean(StoreIndexed* x, LIR_Opr array, LIR_Opr value, CodeEmitInfo*& null_check_info) {
+  if (x->check_boolean()) {
+    LIR_Opr value_fixed = rlock_byte(T_BYTE);
+    if (TwoOperandLIRForm) {
+      __ move(value, value_fixed);
+      __ logical_and(value_fixed, LIR_OprFact::intConst(1), value_fixed);
+    } else {
+      __ logical_and(value, LIR_OprFact::intConst(1), value_fixed);
+    }
+    LIR_Opr klass = new_register(T_METADATA);
+    __ move(new LIR_Address(array, oopDesc::klass_offset_in_bytes(), T_ADDRESS), klass, null_check_info);
+    null_check_info = NULL;
+    LIR_Opr layout = new_register(T_INT);
+    __ move(new LIR_Address(klass, in_bytes(Klass::layout_helper_offset()), T_INT), layout);
+    int diffbit = Klass::layout_helper_boolean_diffbit();
+    __ logical_and(layout, LIR_OprFact::intConst(diffbit), layout);
+    __ cmp(lir_cond_notEqual, layout, LIR_OprFact::intConst(0));
+    __ cmove(lir_cond_notEqual, value_fixed, value, value_fixed, T_BYTE);
+    value = value_fixed;
+  }
+  return value;
+}