RIGHTSHIFTOVR

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

Description    The compiler has detected a right shift count that is
               greater than or equal to the size of the operand to
               be shifted (before application of the integral
               promotions).  This might not be what you intended, as
               the result contains none of the original bits of the
               operand.  For an unsigned operand, the result is
               always 0.  For a signed operand, the result is either
               0 or -1, depending on whether or not the operand had
               a negative value.  The same result would be achieved
               by shifting a signed operand one fewer bits.

User Action    Correct the shift count (or replace the expression by
               0 if appropriate).