Daniel Berlin wrote: > i'm not sure what nop does > Does it really output a nop to the instruction stream? It appears to just throw its arguments away http://msdn.microsoft.com/library/en-us/vclang/html/vcref__noop.asp The __noop intrinsic specifies that a function should be ignored and the argument list unevaluated. It is intended for use in global debug functions that take a variable number of arguments. I'm not a preprocessor guru (or a GCC-builtins guru) so I don't know what to suggest :-/ Rup.