optimising recursive functions

[Robert Dewar]

skaller wrote:

> So I am guessing the Felix version is lucky there are
> no gratuitous temporaries to be saved when this happens,
> and the C code is unlucky and there are.
> 
> Maybe someone who knows how the optimiser works can comment?

One problem with departing from the ABI even on a local level
like this is that it wipes out lots of tools that depend on
ABI compliance for the entire call chain. I suspect the overall
gain is too small to be worth this hit.