Performance vs Raku

[philiprbrenan]

Please tell me why Perl is so much slower then Raku in this instance?

time raku test.raku >/dev/null

real    0m0.640s
user    0m0.674s
sys     0m0.028s

time perl -Mbigint test.raku >/dev/null

real    0m15.599s
user    0m15.597s
sys     0m0.000s

cat test.raku
my ($prev, $current) = (1, 0);

for (0..100_000) {
    ($prev, $current) = ($current, $prev + $current);
}
print $current;

[xenu]

It's slow because by default it's using a pure-perl backend (Math::BigInt::Calc). If you want to make it run faster, use some XS backend.

For example, this will use Math::BigInt::GMP:
perl -M'bigint=only,GMP' test.raku

and this Math::BigInt::Pari:
perl -M'bigint=only,Pari' test.raku

Anyway, bigint is maintained on CPAN (as a part of the bignum distribution), so any issues with it should be reported on its bugtracker, which is located here.

[eserte]

On my system, GMP and raku's bigint implementation are comparable. Pari is somewhat slower:

$ time perl5.32.0 -Mbigint=only,Pari test.raku >/dev/null
perl5.32.0 -Mbigint=only,Pari test.raku > /dev/null  0.81s user 0.01s system 99% cpu 0.818 total

$ time perl5.32.0 -Mbigint=only,GMP test.raku >/dev/null
perl5.32.0 -Mbigint=only,GMP test.raku > /dev/null  0.66s user 0.00s system 99% cpu 0.662 total

$ time ~/rakudo/bin/raku test.raku >/dev/null 
~/rakudo/bin/raku test.raku > /dev/null  0.71s user 0.03s system 109% cpu 0.677 total