InterlockedIncrement64 Available?

In wdm.h, i’ve found these:

   #define InterlockedIncrement64 _InterlockedIncrement64
   InterlockedIncrement64 (
       _Inout_ _Interlocked_operand_ LONG64 volatile *Addend

But after some search “InterlockedIncrement” ( is the only one documented which takes a LONG argument:

  LONG CDECL_NON_WVMPURE InterlockedIncrement(
    [in, out] LONG volatile *Addend

So what is the proper way to increment a 64bit argument ? Should we just call InterlockedIncrement64 directly?

That’s what I would do. I’d also file a bug on the docs, indicating the 64-bit variant is undocumented. I’m sure the doc writers will appreciate this, and if there happens to be some strange reason the decision to not doc the function is intentional, they’ll telll you.


note also that modern compilers implement these as intrinsics and emit the lock instructions directly. That may be why they aren’t in this part of the documentation