Instead of markers, I like to use typedefs instead. Here's an example how this would look like in a HPC related program. Basically, if you know Fortran, you know where this is coming from.
typedef const double * const __restrict__ IN;
typedef double * const __restrict__ OUT;
typedef const int INT_VALUE;
typedef const double FP_VALUE;
void diffuse_c(
OUT runtime_total_s,
OUT runtime_boundary_s,
OUT thermal_energy_updated,
IN thermal_energy,
INT_VALUE nx,
INT_VALUE ny,
INT_VALUE nz
);
You're right, I have been thinking about this naming as well. I think in this context, "INT_PARAM" would be better. I like to typedef it because this way it's easier to replace with a hardware specific integer type later on if I decide to do so. Anyways, the "VALUE" naming is coming from Fortran, which is by default pass-by-reference, so you use it to get pass-by-value.
Edit: Thinking about it some more, "INT_VALUE" still makes sense - it makes it clear that this specific symbol should be accessed as a value, not as a pointer. Doing this reminds me that I'm (probably) imposing more register pressure by passing by value. In general I'd probably pass a const int * const pointer here, but in this specific case I needed values because of some CUDA specific limitation.
