🚀 go-pugleaf

In article <1992Dec14.124529@cs.utwente.nl> fijma@cs.utwente.nl (Duco Fijma) writes:
>|> it's up to the called routine.  It's this difference that gives the Pascal 
>|> convention the edge:  every time you call a C-convention routine you need to 
>|> fix up the stack afterward, while a Pascal-convention routine does 
>|> it in just one place.  On a PC, there's even a special form of RET to 
>|> support the Pascal convention.  
>
>Waht difference does this make for execution time? The cleanup code has to be
>executed for every invocation, whether it is included with the callers or the
>called code. Of course it does make difference for the code size.

A Pascal routine with 20 bytes of parameters can return and clean up with 
the single instruction:

     retf 20

On all 80x86 cpus, this takes the same time (plus or minus a cycle) as the 
plain retf.  The advantage comes because that's all that's needed; a return 
from a C convention routine must be followed by manual adjustment of 
the stack pointer.

Duncan Murdoch