This option makes bitfields of type int signed or unsigned.
The C Standard specifies that if the type specifier used in declaring a bitfield is either int, or a typedef name defined as int, then whether the bitfield is signed or unsigned is dependent on the implementation.
The default is
if you specify an ARM Linux configuration file on the command line
and you use
the default is
The AAPCS requirement for bitfields to default to unsigned on ARM, is relaxed in version 2.03 of the standard.