time /opt/perl-5.26.1/bin/perl -Mntheory=:all -E 'say Pi(1e6)' | wc -c
1000002

 0m  1.524s  using system gmp libraries
 0m  1.168s  using gmp libraries from /opt/perl-5.26.1/lib

time /opt/perl-5.26.1/bin/perl -Mntheory=:all -E 'say Pi(1e9)' | wc -c
1000000002

91m  7.581s  using system gmp libraries
67m 40.951s  using gmp libraries from /opt/perl-5.26.1/lib