Extra Fortran_FLAGS in `flags.make` with arm64: Should I have them?

I’ve recently been experimenting with getting a climate model I work on working on M1 Mac. Thanks to the GCC folks, I got it to run! However, one thing I noticed as I was experimenting is that when I build on my M1 Mac, at the end of the flags.make (for one file/target I randomly picked):

Fortran_FLAGSarm64 = -O2 -march=armv8-a ...

Fortran_FLAGS = -O2 -march=armv8-a ...

where the two lines seem to be identical.

But, on my Intel Mac, in flags.make I only see a Fortran_FLAGS line. No “Fortran_FLAGSx86_64” or whatever the relevant arch would be.

Is this expected with CMake+Make on M1? I’ve been staring at the CMake in my model and I don’t think I ever define any sort of flag variable that is suffixed with arm64 or the machine arch.

It seems that this comes from a loop which sets a <LANG>_FLAGS<ARCH> variable in the makefiles per arch present in the target’s OSX_ARCHITECTURES property (with per-config variants). If unset, it uses an internal variable for the arches. I don’t think there’s much to worry about.

@ben.boeckel Thanks! I figured it wasn’t too crucial, just wanted to make sure there wasn’t a weird extra set of flags I should be setting!