IKVM.Internal.CodeEmitter.EmitNullCheck C# (CSharp) Method

        internal void EmitNullCheck()
        {
            // I think this is the most efficient way to generate a NullReferenceException if the reference is null
            Emit(OpCodes.Ldvirtftn, objectToString);
            Emit(OpCodes.Pop);
        }

 private static bool Object_getClass(DynamicTypeWrapper.FinishContext context, CodeEmitter ilgen, MethodWrapper method, MethodAnalyzer ma, int opcodeIndex, MethodWrapper caller, ClassFile classFile, Instruction[] code, InstructionFlags[] flags)
 {
     // this is the null-check idiom that javac uses (both in its own source and in the code it generates)
     if (code[opcodeIndex + 1].NormalizedOpCode == NormalizedByteCode.__pop)
     {
         ilgen.Emit(OpCodes.Dup);
         ilgen.EmitNullCheck();
         return(true);
     }
     // this optimizes obj1.getClass() ==/!= obj2.getClass()
     else if (opcodeIndex + 3 < code.Length &&
              (flags[opcodeIndex + 1] & InstructionFlags.BranchTarget) == 0 &&
              (flags[opcodeIndex + 2] & InstructionFlags.BranchTarget) == 0 &&
              (flags[opcodeIndex + 3] & InstructionFlags.BranchTarget) == 0 &&
              code[opcodeIndex + 1].NormalizedOpCode == NormalizedByteCode.__aload &&
              code[opcodeIndex + 2].NormalizedOpCode == NormalizedByteCode.__invokevirtual &&
              (code[opcodeIndex + 3].NormalizedOpCode == NormalizedByteCode.__if_acmpeq || code[opcodeIndex + 3].NormalizedOpCode == NormalizedByteCode.__if_acmpne) &&
              (IsSafeForGetClassOptimization(ma.GetStackTypeWrapper(opcodeIndex, 0)) || IsSafeForGetClassOptimization(ma.GetStackTypeWrapper(opcodeIndex + 2, 0))))
     {
         ClassFile.ConstantPoolItemMI cpi = classFile.GetMethodref(code[opcodeIndex + 2].Arg1);
         if (cpi.Class == "java.lang.Object" && cpi.Name == "getClass" && cpi.Signature == "()Ljava.lang.Class;")
         {
             // we can't patch the current opcode, so we have to emit the first call to GetTypeHandle here
             ilgen.Emit(OpCodes.Callvirt, Compiler.getTypeMethod);
             code[opcodeIndex + 2].PatchOpCode(NormalizedByteCode.__intrinsic_gettype);
             return(true);
         }
     }
     return(false);
 }