Rotates all bits of the register one place left through the C (carry)
        bit. This is a 9-bit rotation.

        source code forms: ROL Q; ROLA; ROLB

        CC bits "HNZVC": -aaas

def ROL(self, a):
        """
        Rotates all bits of the register one place left through the C (carry)
        bit. This is a 9-bit rotation.

        source code forms: ROL Q; ROLA; ROLB

        CC bits "HNZVC": -aaas
        """
        r = (a << 1) | self.C
        self.clear_NZVC()
        self.update_NZVC_8(a, a, r)
        return r