src/share/vm/opto/parse3.cpp

*** 175,184 ****
--- 175,186 ----
      }
    }
  
    ciType* field_klass = field->type();
    bool is_vol = field->is_volatile();
+   // TODO change this when we support non-flattened value type fields that are non-static
+   bool flattened = (bt == T_VALUETYPE) && !field->is_static();
  
    // Compute address and memory type.
    int offset = field->offset_in_bytes();
    const TypePtr* adr_type = C->alias_type(field)->adr_type();
    Node *adr = basic_plus_adr(obj, obj, offset);
*** 202,211 ****
--- 204,228 ----
          type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
        }
        assert(type != NULL, "field singleton type must be consistent");
      } else {
        type = TypeOopPtr::make_from_klass(field_klass->as_klass());
+       if (bt == T_VALUETYPE && !flattened) {
+         // A non-flattened value type field may be NULL
+         bool maybe_null = true;
+         if (field->is_static()) {
+           // Check if static field is already initialized
+           ciInstance* mirror = field->holder()->java_mirror();
+           ciObject* val = mirror->field_value(field).as_object();
+           if (!val->is_null_object()) {
+             maybe_null = false;
+           }
+         }
+         if (maybe_null) {
+           type = type->is_valuetypeptr()->cast_to_ptr_type(TypePtr::BotPTR);
+         }
+       }
      }
    } else {
      type = Type::get_const_basic_type(bt);
    }
    if (support_IRIW_for_not_multiple_copy_atomic_cpu && field->is_volatile()) {
*** 215,226 ****
    // Build the load.
    //
    MemNode::MemOrd mo = is_vol ? MemNode::acquire : MemNode::unordered;
    bool needs_atomic_access = is_vol || AlwaysAtomicAccesses;
    Node* ld = NULL;
!    if (bt == T_VALUETYPE && !field->is_static()) {
!     // Load flattened value type from non-static field
      ld = ValueTypeNode::make(_gvn, field_klass->as_value_klass(), map()->memory(), obj, obj, field->holder(), offset);
    } else {
      ld = make_load(NULL, adr, type, bt, adr_type, mo, LoadNode::DependsOnlyOnTest, needs_atomic_access);
    }
  
--- 232,243 ----
    // Build the load.
    //
    MemNode::MemOrd mo = is_vol ? MemNode::acquire : MemNode::unordered;
    bool needs_atomic_access = is_vol || AlwaysAtomicAccesses;
    Node* ld = NULL;
!    if (flattened) {
!     // Load flattened value type
      ld = ValueTypeNode::make(_gvn, field_klass->as_value_klass(), map()->memory(), obj, obj, field->holder(), offset);
    } else {
      ld = make_load(NULL, adr, type, bt, adr_type, mo, LoadNode::DependsOnlyOnTest, needs_atomic_access);
    }