🚀 go-pugleaf

kers@hplb.hpl.hp.com (Chris Dollin) writes:
>   And remember that Acorn's C compiler (the ARM proc. call std.?) is clever
>   enough to notice when you call a function that does not call another (a
>   leaf function), and does not bother with most of the context-storing
>   operations involved in normal function calls.

>I'm not sure you said what you meant. There's no cleverness involved in calling
>a leaf function (after all, who's to know that it *is* a leaf function?), it's
			     ^^^^^^^^^^^^^ Mr. Compiler knows.

>just that leaf functions don't need to carry all the baggage of a full function
>call -- it's the code of the leaf that ``does not bother with most of the
>context-storing operations''. [They don't carry the baggage because there's
>very little that can go wrong inside them, so they don't need to record who
>they are in case something does.]

Actually, I thought that they didn't bother stacking anything because the
compiler *knows* they are leaf-functions. Leaf functions being defined as
functions which do not call any other functions; this means that you *know*
the function doesn't call anyone else, so you *know* that you don't need to
bother with stacking stuff that you would otherwise need to restore context
on return from a called function.
-- 
_________________  "I'd like to answer this question in two ways:
  /____ _ _/_ __       First in my normal voice, and then
 // / //_//_ /_/       in a silly, high-pitched whine." (Monty Python)