8256478: C2 compilation fails with assert(t1->isa_long()) failed: Type must be a long

Reviewed-by: roland, chagedorn, kvn

Author: TobiHartmann

src/hotspot/share/opto/mulnode.cpp

@@ -1490,13 +1490,13 @@ const Type* RotateLeftNode::Value(PhaseGVN* phase) const {
 }
 
 Node* RotateLeftNode::Ideal(PhaseGVN *phase, bool can_reshape) {
-  const Type *t1 = phase->type(in(1));
-  const Type *t2 = phase->type(in(2));
+  const Type* t1 = phase->type(in(1));
+  const Type* t2 = phase->type(in(2));
   if (t2->isa_int() && t2->is_int()->is_con()) {
     if (t1->isa_int()) {
       int lshift = t2->is_int()->get_con() & 31;
       return new RotateRightNode(in(1), phase->intcon(32 - (lshift & 31)), TypeInt::INT);
-    } else {
+    } else if (t1 != Type::TOP) {
       assert(t1->isa_long(), "Type must be a long");
       int lshift = t2->is_int()->get_con() & 63;
       return new RotateRightNode(in(1), phase->intcon(64 - (lshift & 63)), TypeLong::LONG);