def p_BIT_ix(p):
    """ asm : bitop expr COMMA reg8_I
            | bitop pexpr COMMA reg8_I
    """
    bit = p[2].eval()
    if bit < 0 or bit > 7:
        error(p.lineno(3), 'Invalid bit position %i. Must be in [0..7]' % bit)
        p[0] = None
        return

    p[0] = Asm(p.lineno(3), '%s %i,%s' % (p[1], bit, p[4][0]), p[4][1])
asm : bitop expr COMMA reg8_I
            | bitop pexpr COMMA reg8_I