Passing small structs in C

Hi prog. Got a C89 problem.

I want to pass small (less than 64B) structs throught functions that I can't inline because they are used several times elsewhere and are quite big. But it still need it to be very fast.

Should I pass the structs directly (thus copying them) or use a pointer (and getting a dereference penalty) ?

>>6
There's no need to be mean. But if they are hidden functions they don't need to adhere to a calling convention, so >>6 doesn't contradict >>5.