Leo suggested: > $P0."recursion_limit"(10000) As it happens, a recursion limit of 10000 is enough to complete the Ackermann benchmark.
> Optimized build? Which runcore? Currently parrot -C may perform fastest. With Parrot 0.4.0, no optimizations, default runcore, Ack(3, 9) takes 233 seconds of CPU time. With "-C" this reduces to 205 seconds. I haven't tried an optimized Parrot build (so many things to do, so little time...). On the same machine, Python 2.4.1 computes Ack(3, 9) in 12 seconds, and SmartEiffel computes it in something under 0.05 second. I'm sure that this result reflects poor PIR generation by the Amber compiler, rather than the performance of the Parrot VM. I'm happy enough, at this stage, that the program prints the correct result. Regards, Roger Browne
