--- a/src/share/vm/opto/memnode.cpp	Tue Apr 07 11:20:51 2015 +0200
+++ b/src/share/vm/opto/memnode.cpp	Tue Apr 07 14:58:49 2015 +0200
@@ -859,6 +859,10 @@
 
 
 //=============================================================================
+// Should LoadNode::Ideal() attempt to remove control edges?
+bool LoadNode::can_remove_control() const {
+  return true;
+}
 uint LoadNode::size_of() const { return sizeof(*this); }
 uint LoadNode::cmp( const Node &n ) const
 { return !Type::cmp( _type, ((LoadNode&)n)._type ); }
@@ -1251,6 +1255,16 @@
               result = new (phase->C) ConvI2LNode(phase->transform(result));
             }
 #endif
+            // Boxing/unboxing can be done from signed & unsigned loads (e.g. LoadUB -> ... -> LoadB pair).
+            // Need to preserve unboxing load type if it is unsigned.
+            switch(this->Opcode()) {
+              case Op_LoadUB:
+                result = new (phase->C) AndINode(phase->transform(result), phase->intcon(0xFF));
+                break;
+              case Op_LoadUS:
+                result = new (phase->C) AndINode(phase->transform(result), phase->intcon(0xFFFF));
+                break;
+            }
             return result;
           }
         }
@@ -1455,7 +1469,7 @@
 }
 
 //------------------------------Ideal------------------------------------------
-// If the load is from Field memory and the pointer is non-null, we can
+// If the load is from Field memory and the pointer is non-null, it might be possible to
 // zero out the control input.
 // If the offset is constant and the base is an object allocation,
 // try to hook me up to the exact initializing store.
@@ -1480,6 +1494,7 @@
       && phase->C->get_alias_index(phase->type(address)->is_ptr()) != Compile::AliasIdxRaw) {
     // Check for useless control edge in some common special cases
     if (in(MemNode::Control) != NULL
+        && can_remove_control()
         && phase->type(base)->higher_equal(TypePtr::NOTNULL)
         && all_controls_dominate(base, phase->C->start())) {
       // A method-invariant, non-null address (constant or 'this' argument).
@@ -2007,9 +2022,8 @@
 //=============================================================================
 //----------------------------LoadKlassNode::make------------------------------
 // Polymorphic factory method:
-Node *LoadKlassNode::make( PhaseGVN& gvn, Node *mem, Node *adr, const TypePtr* at, const TypeKlassPtr *tk ) {
+Node* LoadKlassNode::make(PhaseGVN& gvn, Node* ctl, Node *mem, Node *adr, const TypePtr* at, const TypeKlassPtr *tk) {
   Compile* C = gvn.C;
-  Node *ctl = NULL;
   // sanity check the alias category against the created node type
   const TypePtr *adr_type = adr->bottom_type()->isa_ptr();
   assert(adr_type != NULL, "expecting TypeKlassPtr");
@@ -2029,6 +2043,12 @@
   return klass_value_common(phase);
 }
 
+// In most cases, LoadKlassNode does not have the control input set. If the control
+// input is set, it must not be removed (by LoadNode::Ideal()).
+bool LoadKlassNode::can_remove_control() const {
+  return false;
+}
+
 const Type *LoadNode::klass_value_common( PhaseTransform *phase ) const {
   // Either input is TOP ==> the result is TOP
   const Type *t1 = phase->type( in(MemNode::Memory) );