Section 3 with Remik (rz33@cornell.edu) 
Meeting #3 Notes
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Administrivia:  Include headers for each file submitted, otherwise 1 point deduction per file
		Grading scale will be 100 point based (not 7 as I alluded to last week)
		Get the grades from the CSUGLAB grades link (find on course website)
Review:		High level language compiled to Sam
		-	The JUMP(C) instruction
		-	If, else statements
		-	do, while loops
		Bring together with syntactic sugar example: for loop
		-	explain equivalency
		- 	Sam code example

JUMPC and the 'if' statement
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Bali program:	main()
			int x;
			x := 98;
			if ( (x < 99) )
				x := (x + 1);
			else
				x := 100;
			return x;

SAM equivalent:	ADDSP 2		// rv & x variables
		PUSHIMM 98	
		STOREOFF 1	// initialize x
		PUSHOFF 1
		PUSHIMM 99
		LESS		// precondition
		JUMPC true

		false:		// test failed; label used for illustrative purposes
		PUSHIMM 100
		STOREOFF 1	// x := 100

		true:		// test passed
		PUSHIMM 1
		PUSHOFF 1
		ADD		// x := x + 1
		STOREOFF 0
		ADDSP -1
		STOP

Syntactic Sugar Employing JUMPC: the 'for' loop statement
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The 'for' loop is just a 'while' loop rewritten in a more
concise, precondition/postcondition form.  For example,
we might have a loop with a general structure as follows:

	int counter, googol;
	counter := 0;
	googol := 10;
	while (counter < 100)
	{
		googol := (googol * 10);
		counter := (counter + 1);
	}

which is equivalent to 

	int counter, googol;
	for(	counter := 0, googol := 10;	// initialize
		(counter < 100); 		// test
		counter := (counter + 1)	// increment
	   )
	{
		googol := (googol * 10);
	}

In SAM we would have:
	ADDSP 3		// rv, counter & googol
	PUSHIMM 0	
	STOREOFF 1	// counter
	PUSHIMM 10
	STOREOFF 2	// googol

	looptest:
	PUSHOFF 1
	PUSHIMM 100
	LESS
	JUMPC true
	JUMP exitloop	// we've calculated googol

	true:
	PUSHOFF 2
	PUSHIMM 10
	TIMES
	STOREOFF 2	// googol = googol * 10
	PUSHOFF 1	
	PUSHIMM 1
	ADD
	STOREOFF 1	// counter = counter + 1
	JUMP looptest	// try to loop again

	exitloop:	// code following loop
	PUSHOFF 2
	STOREOFF 0
	ADDSP -2
	STOP		// what's the final answer? should be non-sense :)