`define compile error

Model Technology ModelSim ALTERA vlog 10.1d Compiler 2012.11 Nov  2 2012
-- Compiling module cordic_atan
** Error: cordic_atanp2.sv(146): near "[": syntax error, unexpected '[', expecting ')'

`define ATAN_ITER(x)     cordicatan_micro  #(                         
                                        .wid            (wi)                   
                                    ,   .wa             (wo)                   
                                    ,   .ITER_SHIFT     (x)           
                                    ,   .ITER_ATAN      (atan_``x )   
                                )  cordicatan_iter``x  (              
                                          .i_clk        (clk)                  
                                    ,     .i_enable     (e[x])        
                                    ,     .i_xold       (x[x])        
                                    ,     .i_yold       (y[x])        
                                    ,     .i_aold       (z[x])        
                                    ,     .o_nxt_en     (e[x+1])      
                                    ,     .o_xnew       (x[x+1])      
                                    ,     .o_ynew       (y[x+1])      
                                    ,     .o_anew       (z[x+1])      
                                );

note x[x]

that 's why