[Bug c/94631] Wrong codegen for arithmetic on bitfields

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94631

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Rich Felker from comment #2)
> So basically the outcome of DR120 was allowing the GCC behavior? It still
> seems like a bad thing, not required, and likely to produce exploitable bugs
> (due to truncation of arithmetic) as well as very poor-performance code (due
> to constant masking).

Note this only matters when the size of the bit-field is less than the size of
int.