yosys/tests/opt/opt_share_mux_tree.v

module opt_share_test(
	input [15:0] 			a,
	input [15:0] 			b,
	input [15:0] 			c,
	input [1:0] 			sel,
	output reg [15:0] res
	);

	always @* begin
		case(sel)
			0: res = a + b;
			1: res = a - b;
			2: res = a + c;
			default: res = 16'bx;
		endcase
	end

endmodule