integer wraparound

[ivan-pi]

With newer gfortran versions, integer wraparound should be enabled explicitly with the -fwrapv flag. See also,

• https://gcc.gnu.org/onlinedocs/gfortran/Behavior-on-integer-overflow.html#:~:text=The%20behavior%20of%20gfortran%20on,detect%20such%20code%20at%20runtime.
• https://fortran-lang.discourse.group/t/i-think-stdlib-should-have-printf-and-fprintf-with-c-style-formatting/6966/40?u=ivanpribec

[ivan-pi]

As discussed on Discord (https://discord.com/channels/465585922579103744/465586212804100106/1194229933216641114) I could also increase the register width and mask the result of certain instructions.