🚀 go-pugleaf

In article <1992Aug13.130618.18871@odin.diku.dk> torbenm@diku.dk
(Torben AEgidius Mogensen) writes:

>Afeature I have sorely missed in compilers for C etc. is a cheap
>tail-call: if the last thing you do in a procedure or function is to
>call a procedure or function, this can be implemented as a goto rather
>than a general procedure/function call. Also, the local variables of
>the calling procedure need not be saved before the call, as they will
>never be used again. Note that this is not a laguage feature, but a
>compiler feature. This requires a callee-saves-registers strategy, but
>that is often the simplest anyway.
>

It's curious that this should be posted in an Acorn newgroup, since the Acorn
C compiler does indeed do (indeed, has always done) conversion of tail-calls
branches, except when
   the calling function contains a call to setjmp
or the calling function takes the address of an argument
or when compilation is using the -g flag (to avoid confusing the poor user).

It's true that lots of compilers don't do this but, bearing in mind the
background of the compiler's original authors in functional programming, it's
unsurprising that the Aconr compiler does.

Harry Meekings