EE553 Quiz August 8 2015  Name ____________________________________  Student ID __________________

1. Encode MIPS instruction

sll $8, $9, 4

a) 00084902 
b) 00084903 
c) 00094100 
d) 00094102 
e) 00094103 

2. Disassemble MIPS instruction

01084025 		

a) sltu $10, $9, $8 
b) bltz $8, 1f      
c) lb $8, ($8)    
d) srav $9, $8, $10 
e) or $8, $8, $8  

3. What is the result of the following MIPS program execution?

	li	$8, 12
	li	$9, 13
	li	$10, 14
	addu	$8, $9, $10

a) $8=0x0000000c, $9=0x0000000d, $10=00000019
b) $8=0x0000000c, $9=0x0000001a, $10=0000000e
c) $8=0x00000014, $9=0x00000012, $10=00000019
d) $8=0x0000001b, $9=0x0000000d, $10=0000000e
e) $8=0x0000000c, $9=0x0000001a, $10=0000000e

4. What is the result of the following MIPS program execution?

	.data
a1:	.word	0x12345678
	.word	0x9abcdef0
	.word	0x11111111
	.word	0x22222222
	.word	0x33333333
	.text
ld1:	la	$8, a1
	or	$9, $8, $8
	lw	$8, ($8)
	sw	$8, 8 ($9)

a) $8=0x00000056
b) $8=0x12345678
c) $8=0x00000012
d) $8=0xffffff9a
e) $8=0x9abcdef0

5. What is the result of the following MIPS program execution?

bne1:	li	$8, 12
	li	$9, 13
	bne	$8, $9, 1f
	li	$10, 14
	li	$10, 15
1:

a) $10 = 12
b) $10 = 13
c) $10 = 14
d) $10 = 15
e) $10 = 0x1f

6. What is the purpose of using program stack in assembly (and any other) programming?

a) Stack is needed to store return addresses for the nested function calls
b) Stack is used to pass function parameters when there is no place on registers
c) Stack is used to allocate space for temporary variables when there is no place on registers
d) Stack is used to save some temporary registers when calling a function
e) All the above

7. What MIPS assembly code corresponds to the following C code?

int e;

void f (int a, int b, int mask)
{
    e = (a & mask) | (b & ~ mask);
}

////////// a //////////

f:
	li	$3,1
	beq	$4,$3,.L3
	li	$3,2

	beq	$4,$3,.L6
	nop

	bne	$4,$0,.L9
	nop

	lw	$2,%gp_rel(a)($28)
	j	$31
	sltu	$2,$0,$2

.L3:
	li	$2,2
	lw	$3,%gp_rel(b)($28)
	j	$31
	movz	$2,$0,$3

.L6:
	move	$2,$0
.L9:
	j	$31
	nop

////////// b //////////

f:
	addiu	$sp,$sp,-24
	sw	$31,20($sp)
	sw	$16,16($sp)
	move	$16,$4
	beq	$4,$0,.L2
	li	$2,1

	jal	f
	addiu	$4,$4,-1

	mul	$2,$2,$16
.L2:
	lw	$31,20($sp)
	lw	$16,16($sp)
	j	$31
	addiu	$sp,$sp,24

////////// c //////////

f:
	slt	$3,$5,$4
	bne	$3,$0,.L5
	nop

	addu	$2,$2,$4
.L4:
	addiu	$4,$4,1
	slt	$3,$5,$4
	beq	$3,$0,.L4
	addu	$2,$2,$4

	subu	$2,$2,$4
.L5:
	j	$31
	nop

////////// d //////////

f:
	nor	$2,$0,$6
	and	$5,$2,$5
	and	$4,$4,$6
	or	$2,$5,$4
	j	$31
	sw	$2,%gp_rel(e)($28)

////////// e //////////

f:
	lui	$3,%hi(a)
	addiu	$3,$3,%lo(a)
	addiu	$5,$3,40
.L3:
	lw	$4,0($3)
	addiu	$3,$3,4
	bne	$3,$5,.L3
	addu	$2,$2,$4

	j	$31
	nop

///////////////////////

Quiz is created by Yuri Panchul