CS220 Week 6 Homework Due Mar 18, 2016

Name:

1. What is the difference between a return value and a return address?
     
2. Assuming full data alignment is enforced, given the following code...
   
	   struct shape {
	   	enum color {red, green, blue} shapeColor;
		int width;
		int height;
		int depth;
	   } shapeA[5];
	   printf("Shape matrix starts at %p\n",shapeA);
	   printf("The shapeA[1] starts at %p\n",shapeA+1);
	   
    If the first message prints out: "Shape matrix starts at 0x5fcad0"
    What will the second message print?
	   
3. Given the following C code...

	enum strikers { Giroux, Bony, Rooney, Hazard, Aguero, Costa, Kane } player;
	enum teams { Arsenal, ManCity, ManU, Chelsea, Tottenham } team;
	
   Would the following C code compile without error?
	
	if (player==Giroux) team=Arsenal;
	else if (player==Bony) team=ManCity;
	else if (player==Rooney) team=ManU;
	
  
4. Given the following C code...

	int isDenormal(float x) {
		union {
			float xf;
			int xi;
		} in;
		if (x==0 || x==INFINITY || x==-INFINITY) return 0;
		in.xf=x; // Copy float parameter to union as float
		if (0== (in.xi & 0b01111111100000000000000000000000)) return 1;
		return 0;
	}
	
   a. Would the isDenormal function work correctly without the "union" statement?  Why or why not?
   
   b. What will be returned for isDenormal(1.3e-30)?  What will be returned for isDenormal(1.3e-44)?	   
   
5. Given the following x86 Assembler code:

			cmpl	8(%ebp),$100
			jle	L21
			addl	$1,8(%ebp)
			jmp	L22
		L21	subl	$1,8(%ebp)
		L22	movl	8(%ebp),%eax
			…	
			
    Which of the following lines of C code caused the above assembler code to be generated?
	
	a.	while(arg1<100) { arg1++; }
		arg1--;
		x = arg1;

	b.	for(arg1=100; arg<=100; arg1++) { arg1--; }
		x = arg1;

	c.	if (arg1>100) arg1++;
		else arg1--;
		x = arg1;

	d.	do { arg1--} while(arg1>100);
		arg1++;
		x = arg1;

	e.	if (arg1<=100) arg1++;
		else arg1--;