Re: FIG Forth's NEXT function confuses me slightly
Posted: Thu Aug 11, 2022 12:44 am
BruceRMcF wrote:
(2) Even if NEXT is in the Dictionary in the form of NOP, DROP is used a LOT more than NOP, so doing (1) and then just having "JMP NEXT" for the NOP code would be a simple speed optimization with very little code space impact.
With an ITC (Indirect Threaded Code) Forth, a primitive normally has a code field which points to its body, but not always. In my Forth, the high level no-op is called NOOP . Since my Forth is an ITC Forth, NOOP is not "JMP NEXT". NOOP has no body and its code field points to NEXT .
My Forth has LIT fall into NEXT but I'm writing an experimental kernel where (LOOP) would fall through into NEXT . The way my DO LOOP's are implemented, LEAVE and EXIT would also fall into NEXT .