diff --git a/TESTBENCH/barrel_shifter_tb.v b/TESTBENCH/barrel_shifter_tb.v
index 1121999..3a08dbb 100644
--- a/TESTBENCH/barrel_shifter_tb.v
+++ b/TESTBENCH/barrel_shifter_tb.v
@@ -18,7 +18,7 @@ reg LnR;
 wire [31:0] Y;
 
 integer reg_idx;
-reg [`DATA_INDEX_LIMIT:0] result[0:63];
+reg [`DATA_INDEX_LIMIT:0] result[0:123];
 
 integer i, e;
 integer no_of_test=0;
@@ -33,7 +33,7 @@ D=32'ha5a5a5a5;
 S=32'h00000000;
 LnR=1'b1; // left shift
 
-for(i=1; i<33; i=i+1)
+for(i=1; i<63; i=i+1)
 begin
 #5 
 no_of_test = no_of_test + 1;
@@ -51,7 +51,7 @@ end
 
 #5 LnR=1'b0; // right shift
 
-for(i=1; i<33; i=i+1)
+for(i=1; i<63; i=i+1)
 begin
 #5 
 no_of_test = no_of_test + 1;
diff --git a/alu.v b/alu.v
index c4792ea..a488d62 100644
--- a/alu.v
+++ b/alu.v
@@ -31,11 +31,12 @@ input [`ALU_OPRN_INDEX_LIMIT:0] OPRN; // operation code
 output [`DATA_INDEX_LIMIT:0] OUT; // result of the operation.
 output ZERO;
 
-wire [31:0] res,
+wire [31:0] //res,
             res_addsub, res_slt,
             res_shift,
             res_mul,
             res_and, res_or, res_nor;
+wire [31:0] res;
 
 // add = xx0001
 // sub = xx0010
@@ -71,16 +72,10 @@ MUX32_16x1 out(.Y(res), .S(OPRN[3:0]),
 );
 
 // or bits of result for zero flag
-wire nzf [31:0];
-buf (nzf[0], res[0]);
-genvar i;
-generate
-    for (i = 1; i < 32; i = i + 1) begin : zf_gen
-        or (nzf[i], nzf[i-1], res[i]);
-    end
-endgenerate
+wire nzf;
+or (nzf, res[24:0]);
 
-not (ZERO, nzf[31]);
+not (ZERO, nzf);
 buf res_out [31:0] (OUT, res);
 
 endmodule
diff --git a/barrel_shifter.v b/barrel_shifter.v
index db6cb85..44c20e7 100644
--- a/barrel_shifter.v
+++ b/barrel_shifter.v
@@ -22,20 +22,14 @@ input [31:0] S;
 input LnR;
 
 // check if upper bits are nonzero
-wire oob [31:5];
-buf (oob[5], S[5]);
-genvar i;
-generate
-    for (i = 6; i < 32; i = i + 1) begin : shift_oob_gen
-        or (oob[i], oob[i-1], S[i]);
-    end
-endgenerate
+wire oob;
+or (oob, S[31:5]);
 
 wire [31:0] shifted;
 BARREL_SHIFTER32 shifter(shifted, D, S[4:0], LnR);
 
 // return 0 if S >= 32
-MUX32_2x1 mux_oob(Y, shifted, 32'b0, oob[31]);
+MUX32_2x1 mux_oob(Y, shifted, 32'b0, oob);
 
 endmodule