8307625: Redundant receiver null check in LibraryCallKit::generate_method_call

Reviewed-by: thartmann, chagedorn

Author: enothum

src/hotspot/share/opto/library_call.cpp

@@ -3982,6 +3982,7 @@ bool LibraryCallKit::inline_unsafe_newArray(bool uninitialized) {
   Node* mirror;
   Node* count_val;
   if (uninitialized) {
+    null_check_receiver();
     mirror    = argument(1);
     count_val = argument(2);
   } else {
@@ -4278,7 +4279,7 @@ LibraryCallKit::generate_method_call(vmIntrinsics::ID method_id, bool is_virtual
     slow_call = new CallStaticJavaNode(C, tf,
                            SharedRuntime::get_resolve_static_call_stub(), method);
   } else if (is_virtual) {
-    null_check_receiver();
+    assert(!gvn().type(argument(0))->maybe_null(), "should not be null");
     int vtable_index = Method::invalid_vtable_index;
     if (UseInlineCaches) {
       // Suppress the vtable call
@@ -4294,7 +4295,7 @@ LibraryCallKit::generate_method_call(vmIntrinsics::ID method_id, bool is_virtual
                           SharedRuntime::get_resolve_virtual_call_stub(),
                           method, vtable_index);
   } else {  // neither virtual nor static:  opt_virtual
-    null_check_receiver();
+    assert(!gvn().type(argument(0))->maybe_null(), "should not be null");
     slow_call = new CallStaticJavaNode(C, tf,
                                 SharedRuntime::get_resolve_opt_virtual_call_stub(), method);
     slow_call->set_optimized_virtual(true);