sh Configure -des -Duse64bitall -Dprefix=/home/sisyphus/perl-5.33.2-d -Uversiononly -Dusedevel -Dd_Gconvert='sprintf((b),"%.*g",(n),(x))' && make ..... Everything is up to date. Type 'make test' to run test suite. $ ./perl -I./lib -le 'printf "%.54g\n", 0.3;' 0.299999999999999988897769753748434595763683319091796875 sisyphus@sisyphus5-desktop:~/comp/perl-5.33.2$ ./perl -I./lib -le 'printf "%.254g\n", 1.7e+251;' 170000000000000005663803942337610846894847225021019179335346179174180972159540155311382167019190199683710077065416340563770116163493829917269156963879713199669324593796274292160502793413259915141049236539345853734303029546817799537579060533492478640128