Is There a 64 Bit or 32 Bit Calling Convention?

There's a comment here that's apparently a something like vector call or some sort of pragma. I is something it worked differently on x 86. On x 86 it could go just directly to the register. That's probably ununduable. There's a compiler explorer lynx for a 64 bit and 32 bit. So i take it there's probably not much they can do here though, without changing the 64 bit calling convention. Talk about an a b eybreak.That's ye.