--- old/src/hotspot/share/opto/superword.cpp	2018-03-12 17:44:11.495070392 -0700
+++ new/src/hotspot/share/opto/superword.cpp	2018-03-12 17:44:11.191069254 -0700
@@ -2325,8 +2325,11 @@
           vn = VectorNode::make(opc, in1, in2, vlen, velt_basic_type(n));
           vlen_in_bytes = vn->as_Vector()->length_in_bytes();
         }
-      } else if (opc == Op_SqrtF || opc == Op_SqrtD || opc == Op_AbsF || opc == Op_AbsD || opc == Op_NegF || opc == Op_NegD) {
-        // Promote operand to vector (Sqrt/Abs/Neg are 2 address instructions)
+      } else if (opc == Op_SqrtF || opc == Op_SqrtD ||
+                 opc == Op_AbsF || opc == Op_AbsD ||
+                 opc == Op_NegF || opc == Op_NegD ||
+                 opc == Op_PopCountI) {
+        assert(n->req() == 2, "only one input expected");
         Node* in = vector_opd(p, 1);
         vn = VectorNode::make(opc, in, NULL, vlen, velt_basic_type(n));
         vlen_in_bytes = vn->as_Vector()->length_in_bytes();