what is the different between * and IP core multiplier

This post is timely, because I have been having an issue related to it. For larger multipliers, lpm_mult creates logic that is much faster. In my case of a signed 32x32 multiply, lpm_mult is double the speed of using "*" in Verilog. For a reference, here is my code:

module mult_test(
	input						CLK,
	input	signed 	IN_A,
	input signed 	IN_B,
	output signed  OUT_C
);
	
	//Verilog version
	reg signed  IN_A_d1;
	reg signed  IN_B_d1;	
	reg signed  mult_result;
	
	assign mult_result = IN_A_d1 * IN_B_d1;
	
	always @(posedge CLK) begin
		IN_A_d1 <= IN_A;
		IN_B_d1 <= IN_B;
		OUT_C <= mult_result;
	end
	
	
	/*
	//Altera LPM Megafunction version
    //Created as signed 32x32 -> 64-bit multiply with 2 cycles of latency
	wire signed  mult_result;
	assign OUT_C = mult_result;
	
	megafunction_mult	megafunction_mult_inst (
		.clock (CLK),
		.dataa (IN_A),
		.datab (IN_B),
		.result (mult_result)
	);*/
endmodule