[Bug c/117266] RFE: builtins for N*N -> 2N multiplication and 2N/N -> N div/mod

[hpa at zytor dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117266

--- Comment #7 from H. Peter Anvin <hpa at zytor dot com> ---
> _BitInt(sizeof(foo_t)*CHAR_BIT)

Should of course have been _BitInt(sizeof(foo_t)*CHAR_BIT*2) ...

        -hpa