Re: [Chicken-users] News from the Barnyard

[Felix Winkelmann]

Joerg F. Wittenberger wrote:
> Anyway: rscheme uses (to my understanding) a register file (vector of
> values) for parameters.  If I keep calling functions, which all have
> the same signature and only modify a few of the parameters, the
> rscheme compiler seems to feed mostly /* NOOP */ to C (except for the
> modified parameters) - hardly beatable in runtime.  Chicken seems to
> fill yet another stack frame.  Am I right?

Yes, right. Peter Keller had an interesting idea about "re-using" stack
frames (or better: using statically allocated ones), but this seems
to break the garbage collector... We have to look more into that.

> Keep in mind: that's a wild guess.  There is also the fact that the
> Scheme interpreter in rscheme apparently compiles into byte code,
> which the one in Askemos does not.  I have no idea, which one would be
> faster.  (Bytecompile effort doesn't really count, the Askemos caches
> quite a few things, also calls to 'eval'.)

Yes, Chicken uses a "closure tree" for interpretation (as in that
paper by Feeley et. al) which is extremely elegant and quite simple
to implement. But a byte-compiler is still much faster, though.
Unfortunately, it's rather tricky to use normal direct-style
byte-compilation in a CPS environment (like Chicken's compiled
code representation) (I tried).


cheers,
felix