INTCONSTSIGN

Message        <Context> conversion of the constant "<constant>" to
               <type> type will cause a change in sign.

Description    Either an unsigned type was assigned a negative
               constant value, or a signed type was assigned a
               positive contant value which will be evalated as a
               negative number after the assignment.  Note that this
               message is not output for assignments to 1-bit
               bitfields.  The message bitconstsign is generated in
               that case.

User Action    If this is what you intended, cast the constant to
               the desired type.  You might also want to change the
               constant to the correct signed or unsigned value in
               order to avoid the optional message intconcastsgn,
               which reports sign changes caused by casts.