VMS Help CC, Messages, SHIFTCOUNT  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 Message        <Context> the shift count "<number>" is negative or
                is greater than or equal to the promoted size of the
                operand "<expression>".

 Description    The compiler has detected a shift count that is
                negative or is greater than or equal to the promoted
                size of the operand to be shifted.  This behavior is
                undefined.

 User Action    Correct the shift count.