Differing range values for same callsite/param

Hello,

When looking at the smatch database, I see the following:

kernel/sys.c|prctl_set_mm|find_vma|556035|0|8017|1|$|0-s32max[c]
kernel/sys.c|prctl_set_mm|find_vma|556035|0|1001|1|$|0-18446744073709551614

and:

mm/mmap.c|__do_munmap|find_vma|607602|0|8017|1|$|1-u32max[c]
mm/mmap.c|__do_munmap|find_vma|607602|0|1001|1|$|1-u64max

I didn't expect the value ranges for the same callsite to be different, is
this a bug - or is there something I'm not understanding?

Thanks,

Andrew Murray