https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91893
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution|--- |DUPLICATE
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Actually this is a dup of PR 88731.
Comment #2 of that PR explains it nicely:
GCC makes the integer type of the bit-field in question "unsigned:4".
See DR#315 (also, see the line of C90 DRs that led to the wording changes
in C99 relating to types of bit-fields, references in
<https://gcc.gnu.org/ml/gcc/2017-10/msg00192.html>).
---- CUT ----
So it is a bit more complex than just integer promotions going on here and it
is implementation defined behavior due to the types.
*** This bug has been marked as a duplicate of bug 88731 ***
