8036667: "assert(adr->is_AddP() && adr->in(AddPNode::Offset)->is_Con())...

8036667: "assert(adr->is_AddP() && adr->in(AddPNode::Offset)->is_Con()) failed: offset is a constant" with FoldStableValues on
Reviewed-by: kvn

src/share/vm/opto/memnode.cpp

@@ -1593,9 +1593,9 @@ LoadNode::load_array_final_field(const TypeKlassPtr *tkls,
 
 // Try to constant-fold a stable array element.
 static const Type* fold_stable_ary_elem(const TypeAryPtr* ary, int off, BasicType loadbt) {
+  assert(ary->const_oop(), "array should be constant");
   assert(ary->is_stable(), "array should be stable");
 
-  if (ary->const_oop() != NULL) {
   // Decode the results of GraphKit::array_element_address.
   ciArray* aobj = ary->const_oop()->as_array();
   ciConstant con = aobj->element_value_by_offset(off);
@@ -1620,8 +1620,6 @@ static const Type* fold_stable_ary_elem(const TypeAryPtr* ary, int off, BasicTyp
       return con_type;
     }
   }
-  }
-
   return NULL;
 }
 
@@ -1641,7 +1639,7 @@ const Type *LoadNode::Value( PhaseTransform *phase ) const {
   // Try to guess loaded type from pointer type
   if (tp->isa_aryptr()) {
     const TypeAryPtr* ary = tp->is_aryptr();
-    const Type *t = ary->elem();
+    const Type* t = ary->elem();
 
     // Determine whether the reference is beyond the header or not, by comparing
     // the offset against the offset of the start of the array's data.
@@ -1653,10 +1651,9 @@ const Type *LoadNode::Value( PhaseTransform *phase ) const {
     const bool off_beyond_header = ((uint)off >= (uint)min_base_off);
 
     // Try to constant-fold a stable array element.
-    if (FoldStableValues && ary->is_stable()) {
-      // Make sure the reference is not into the header
-      if (off_beyond_header && off != Type::OffsetBot) {
-        assert(adr->is_AddP() && adr->in(AddPNode::Offset)->is_Con(), "offset is a constant");
+    if (FoldStableValues && ary->is_stable() && ary->const_oop() != NULL) {
+      // Make sure the reference is not into the header and the offset is constant
+      if (off_beyond_header && adr->is_AddP() && off != Type::OffsetBot) {
         const Type* con_type = fold_stable_ary_elem(ary, off, memory_type());
         if (con_type != NULL) {
           return con_type;