>perl -e"CORE::say $^X"
C:\progs\sp5302x64\perl\bin\perl.exe

>perl -v | find "This is"
This is perl 5, version 30, subversion 2 (v5.30.2) built for MSWin32-x64-multi-thread

>perl -V:nvsize
nvsize='8';

>perl -V:ccflags
ccflags=' -s -O2 -DWIN32 -DWIN64 -DCONSERVATIVE -D__USE_MINGW_ANSI_STDIO -DPERL_TEXTMODE_SCRIPTS -DPERL_IMPLICIT_CONTEXT -DPERL_IMPLICIT_SYS -DUSE_PERLIO -fwrapv -fno-strict-aliasing -mms-bitfields';

>perl -e"CORE::say sprintf '%.20g', 0.1"
0.10000000000000000555