[Shootout-list] ackermann, fibonacci and takfp benchmarks

[Daniel South]

Einar Karttunen wrote:
| "¤WildCard¤" <WildCard_25@HotMail.Com> writes:
||
|| Easy to add to existing programs. At the start of each function.
|| recursion += 1;
|| depth +=1;
|| if (depth > maxdepth) {maxdepth = depth;}
|
| This is actually more expensive than recursion in many languages.

Not really, generally, allocating a new stack frame is more expensive 
than a comparison. The difference will be that global scope variables 
will be changed on every call and *then* compared to, making it harder 
to for the compiler to optimise out the recursion ie. it rely has to 
recurse and not just use a cached value. This will of course impact the 
languages that had been optimising out the recursions, but the whole 
point is to test the cost of calling the function, not to test how well 
the compiler optimises. Tail recursion optimisation should not be 
affected, just the caching.

As a side note: in what languages would a register comparison be more 
expensive than stack frame allocation?

Daniel South