Sign Flipping Twiddling!

to reverse the sign or an integer variable:
var a:int = -i;

can we perform the same operation faster?
with ~ operator:
var a:int = ~i +1;

with XOR operator
var a:int = (i ^ -1) + 1;

which one is the fastest ?

Unbelievable !

What do you get ?

here the code used to profile:

		var i:int;
			var a:int;			
			var val:int;
			
			
			var time1:uint = getTimer();
			
			for(i= 0;i<5000000;i++)
			{
				val = i-2500000;
				a = -val;
				a = -val;
				a = -val;
				a = -val;
				a = -val;
				a = -val;
				a = -val;
				a = -val;
				a = -val;
				a = -val;							
			}

			var time2:uint = getTimer();
			for(i= 0;i<5000000;i++)
			{
				val = i-2500000;
				a = ~val + 1;
				a = ~val + 1;
				a = ~val + 1;
				a = ~val + 1;
				a = ~val + 1;
				a = ~val + 1;
				a = ~val + 1;
				a = ~val + 1;
				a = ~val + 1;
				a = ~val + 1;
			}
			
			var time3:uint = getTimer();
			for(i= 0;i<5000000;i++)
			{
				val = i-2500000;
				a = (val ^ -1) + 1;
				a = (val ^ -1) + 1;
				a = (val ^ -1) + 1;
				a = (val ^ -1) + 1;
				a = (val ^ -1) + 1;
				a = (val ^ -1) + 1;
				a = (val ^ -1) + 1;
				a = (val ^ -1) + 1;
				a = (val ^ -1) + 1;
				a = (val ^ -1) + 1;
			}
			
			var time4:uint = getTimer();