Added all Testbenches to Modelsim and confirmed working operation

ModelSim/shifter.sv

@@ -0,0 +1,19 @@
+`ifndef SHIFTER_H_SV
+`define SHIFTER_H_SV
+module shifter #(width=8)(input logic [2:0] op,
+    input logic[width-1:0] A, input logic[width-1:0] C, input logic[$clog2(width)-1:0] B,
+    output logic[width-1:0] OUT_1);
+
+    always_comb begin
+        case (op)
+            3'b000: OUT_1 = A << C;
+            3'b001: OUT_1 = A >> C;
+            3'b011: OUT_1 = $signed(A) >>> C;
+            3'b100: OUT_1 = A << B;
+            3'b101: OUT_1 = A >> B;
+            3'b111: OUT_1 = $signed(A) >>> B;
+            default:OUT_1 = A;
+        endcase
+    end    
+endmodule
+`endif