The macOS vm system supports large pages, or "superpages" as they call it. It is a native citizen in the mach_vm_map API, and various large page sizes can be passed in with the VM_FLAGS_SUPERPAGE family of flags.

Conveniently, for anonymous mmap memory, these superpage flags that would normally go to the mach_vm_map API, can also be passed into the file descriptor argument of mmap.