Introduction to x64 Assembly

Could you please try the following (enable/disable global optimization at the function/macro level). I'm not sure about macro but theoretically it should definitely work.

#pragma optimize( "g", off )
// Macro goes here
#pragma optimize( "g", on )

Another option would be to enable optimization profiling, (MSVC has one of the worst optimization profiler I've ever seen!) so that you can pinpoint the specific transformation that is getting exercised by the compiler, then you can selectively disable or at least tweak that optimization accordingly which is I'm guessing it's most likely to be inlining!