Math.min Math.max float

In a previous post, I explored ways to accomplish Math.min and max for integers with some bit twiddling
(http://guihaire.com/code/?p=549),
Today, we are going to explore ways to find the min or the max of 2 Numbers without using the infamous Math class.

Lets start with the min.
So the basic:

min = Math.min(i,j);

One way is to use the ternary operator ( cond ? a : b)

min = i<j ? i :j;

We could also use an interpolation method with the interpolant being a value = 0 when i>=j and 1 when i<j:

var m01:Number = Number(i<j);
min = i* m01 + j*(1-m01);					

We can rewritte it:

min = (i-j) * Number(i<j) + j;

Lets look at the generated code:
+1|-0 GetLocal(1)
+1|-0 GetLocal(2)
+1|-2 Subtract()
+1|-0 FindPropStrict(AbcQName(‘Number,AbcNamespace(22,’)))
+1|-0 GetLocal(1)
+1|-0 GetLocal(2)
+1|-2 LessThan()
+1|-2 CallProperty(AbcQName(‘Number,AbcNamespace(22,’)),1)
+1|-2 Multiply()
+1|-0 GetLocal(2)
+1|-2 Add()
+1|-1 ConvertDouble()
+0|-1 SetLocal(5)

Okay, lets try something a bit more compact without the CallProperty calls:

__asm(
						GetLocal(i),                          
						GetLocal(j),                          
						Subtract,   
						GetLocal(j),                          
						GetLocal(i),                          
						LessThan,
						ConvertDouble,
						Multiply,
						GetLocal(j),
						Add,
						SetLocal(max)						
);

Similar code can be done for the Math.max (see at the end)

results!

here the full code:

		private function minmaxFloatTest():void
		{
			var i:Number = 0;
			var j:Number = 0;
			var a:Number;			
			var b:Number;			
			var min:Number;
			var max:Number;
			var m01:Number;
			var iint:int = 0;
			var jint:int = 0;
			
			const REPS:Number = 100;
			const INC:Number = 0.1;
			
			var time1:uint = getTimer();			
			for(i= 0;i<REPS;i+=INC)
			{
				for(j= 0;j<REPS;j+=INC)
				{
					min = Math.min(i,j);
				}
			}
			var time2:uint = getTimer();			
			for(i= 0;i<REPS;i+=INC)
			{
				for(j= 0;j<REPS;j+=INC)
				{
					max = Math.max(i,j);
				}
			}
			var time3:uint = getTimer();			
			for(i= 0;i<REPS;i+=INC)
			{
				for(j= 0;j<REPS;j+=INC)
				{
					m01 = Number(i<j);
					min = i* m01 + j*(1-m01);					
				}
			}
			var time4:uint = getTimer();			
			for(i= 0;i<REPS;i+=INC)
			{
				for(j= 0;j<REPS;j+=INC)
				{
					m01 = Number(i>j);
					max = i* m01 + j*(1-m01);					
				}
			}
			var time5:uint = getTimer();			
			for(i= 0;i<REPS;i+=INC)
			{
				for(j= 0;j<REPS;j+=INC)
				{
					min = (i-j) * Number(i<j) + j;
				}
			}
			var time6:uint = getTimer();			
			for(i= 0;i<REPS;i+=INC)
			{
				for(j= 0;j<REPS;j+=INC)
				{
					max = (i-j) * Number(i>j) + j;
				}
			}
			var time7:uint = getTimer();			

			for(i= 0;i<REPS;i+=INC)
			{
				for(j= 0;j<REPS;j+=INC)
				{
					min = (i<j) ? i : j;
				}
			}
			var time8:uint = getTimer();
			for(i= 0;i<REPS;i+=INC)
			{
				for(j= 0;j<REPS;j+=INC)
				{
					max = (i<j) ? j : i;
				}
			}
			var time9:uint = getTimer();			
			for(i= 0;i<REPS;i+=INC)
			{
				for(j= 0;j<REPS;j+=INC)
				{
					__asm(
						GetLocal(i),                          
						GetLocal(j),                          
						Subtract,   
						GetLocal(i),                          
						GetLocal(j),                          
						LessThan,
						ConvertDouble,
						Multiply,
						GetLocal(j),
						Add,						
						SetLocal(min)						
					);
				}
			}
			var time10:uint = getTimer();			
			for(i= 0;i<REPS;i+=INC)
			{
				for(j= 0;j<REPS;j+=INC)
				{
					__asm(
						GetLocal(i),                          
						GetLocal(j),                          
						Subtract,   
						GetLocal(j),                          
						GetLocal(i),                          
						LessThan,
						ConvertDouble,
						Multiply,
						GetLocal(j),
						Add,
						SetLocal(max)						
					)					
				}
			}
			var time11:uint = getTimer();			
			
			startTest();
			setTest( "Math.min:"  	   , 	 	"float_min",  time2-time1 );
			setTest( "(i<j)?i:j"    ,   		"float_min",  time8-time7 );
			setTest( "min interp v1"   ,   		"float_min",  time4-time3 );			
			setTest( "min interp v2"   ,   		"float_min",  time6-time5 );
			setTest( "min asm"   	   ,   		"float_min",  time10-time9 );
			
			
			setTest( "Math.max:"  , 	 		"float_max",  time3-time2 );
			setTest( "(i<j)?j:i"   ,   		"float_max",  time9-time8 );
			setTest( "max interp v1"   ,   		"float_max",  time5-time4 );			
			setTest( "max interp v2"   ,   		"float_max",  time7-time6 );
			setTest( "max asm"   	   ,   		"float_max",  time11-time10 );
			
			endTest();
		}

What do you get ?