tests/opt/opt_share_add_sub.v - third_party/yosys - Git at Google

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

   assign res = {sel ? a + b : a - b};

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

	assign res = {sel ? a + b : a - b};

	endmodule