70. Universal Barrel Shifter

How do you plan to solve it?

module univ_barrel8 (
    input  [7:0] x,
    input  [2:0] sh,
    input  [2:0] mode,
    output [7:0] y
);

    // Explicit sign extension
    wire signed [8:0] sx_ext;
    assign sx_ext = {x[7], x};

    // Arithmetic shift result stored in a wire
    wire signed [8:0] asr_res;
    assign asr_res = sx_ext >>> sh;

    assign y =
        (mode == 3'b000) ? x :
        (mode == 3'b001) ? (x << sh) :
        (mode == 3'b010) ? (x >> sh) :
        (mode == 3'b011) ? asr_res[7:0] :   // ✅ now legal
        (mode == 3'b100) ? ((x << sh) | (x >> (8 - sh))) :
        (mode == 3'b101) ? ((x >> sh) | (x << (8 - sh))) :
                           x;               // reserved → PASS

endmodule