Assembly Part 1

Question 1

The format and behavior of a machine level program is defined by the ________, defining the processor state, the format of the instructions, and the effect these instructions have on the state.

Answer 1

Instruction set architecture

Question 2

The ______ (commonly referred to as the PC and called %rip) indicate the address of the next instruction to be executed

Answer 2

Program counter

Question 3

The integer _____ contains 16 name location storing 64-bit values. These registers can hold _____ (corresponding to C pointers) or _____ data

Answer 3

Register file, addresses, integer

Question 4

The ____ hold status information about the most recently executed arithmetic or logical instruction. These are used to implement conditional changes in control or data flow such as is required to implement if and while statements

Answer 4

Condition code registers

Question 5

Assembly code suffix for char (1 byte)

Answer 5

B

Question 6

Assembly code suffix for short (2 bytes)

Answer 6

W

Question 7

Assembly code suffix for int

Answer 7

L

Question 8

Assembly code suffix for long

Answer 8

Q

Question 9

Assembly code suffix for char *

Answer 9

Q

Question 10

Assmebly code suffix for float

Answer 10

S

Question 11

Assembly code suffix for double (8 bytes)

Answer 11

L

Question 12

An x86-64 central processing unit (CPU) contains a set of ____ general purpose registers storing ____ bit values

Answer 12

16, 64

Question 13

All of the x86 register we can use expect ____ and ____

Answer 13

Rsp and rbp

Question 14

Rsp and rbp are _____ registers and should not be used for any other purpose

Answer 14

Stack management

Question 15

Rsp is the address of the _____ of the stack (it points to the last value pushed on the stack)

Answer 15

Top

Question 16

Rbp is a frame pointer: it points to the _____ of the stack frame of the function which is currently executing

Answer 16

Bottom

Question 17

The ____ instruction copies a value from one location (operant 1) to another location (operand 2)

Answer 17

Mov

Question 18

The instruction _____, the size of operand 1 and the size of operand 2 must all match

Answer 18

Suffix

Question 19

______: constant integer data. Prefixed with _____

Answer 19

Immediate, $

Question 20

_______: one of the 16 integer ____

Answer 20

Register, registers

Question 21

____: 8 consecutive bytes of memory at address given by register. ____ means read from the address specified in register. (I.e, use value in register as pointer)

Answer 21

Memory, parentheses

(%rax)

Question 22

Memory addressing mode 1

Mem[Reg[R]]

Movq(%rcx), %rax =

Answer 22

Register R specifies a memory address

Rax = *rcx

Question 23

Memory Addressing mode 2

Imm(R) =
Movq 8(%rbp), %rdx =

Answer 23

Mem[Imm+Reg[R]]
Rdx = *(rbp+8)

Question 24

What is size of memory address of coelinux

Answer 24

8 bytes

Question 25

What is the only suffix we should be using when we are calculating/ moving addresses

Answer 25

Q

Question 26

What size register should be use when we are calculating addresses

Answer 26

Rax, rax, red, rdx, r12, etc

Question 27

Is this valid instruction Movq (%ecx), %eax

Answer 27

No, must use rcx not ecx because we are accessing the value at the memory address stored in rcx

Question 28

Is this instruction valid Movb (%rax), %al

Answer 28

Yes

Question 29

Imm(Rb, Ri, S)

Answer 29

Mem[Imm + Reg[Rb] + Reg[Ri]*S]

Question 30

Immediate

Answer 30

Can be an constant value (constant displacement)

Question 31

Rb

Answer 31

Base register, can be any of the 16 registers

Question 32

Ri

Answer 32

Index register

Question 33

Ri can be any of the register except ____

Answer 33

%rsp

Question 34

S

Answer 34

Scale, can only be 1,2,4,8

Question 35

%rdx contains start address of array (0x600400) %rcx contains index into ar1 (e.g 15) What if we want to access arr1[15]

Answer 35

Movl (%rdx,%rcx,4), %eax

Question 36

(Rb,Ri)

Answer 36

Mem[Reg[Rb] + Reg[Ri]]

Question 37

Imm(Rb,Ri)

Answer 37

Mem[Reg[Rb] + Reg[Ri] + Imm]

Question 38

(Rb, Ri, S)

Answer 38

Mem[Reg[Rb] + s*Reg[Ri]]

Question 39

Imm(,Ri,S)

Answer 39

Mem[Imm + Reg[Ri]*S]

Question 40

Imm

Answer 40

Mem[Imm]

Question 41

Suffix and ______ register size must match (on a read from memory). Address calculations are always 8 bytes

Answer 41

Destination

Question 42

Suffix and ______ register size (on a write to memory) must match. Address calculations are always 8 bytes

Answer 42

Source

Question 43

Address computation instruction

Answer 43

Leaq src, dst

Question 44

Leaq computes address without ______

Answer 44

Memory reference

Question 45

Leaq does not affect ______

Answer 45

Condition codes

Question 46

Interpret Leaq 24(%rax, %rcx, 4), %rdx

Answer 46

Compute a 8-byte value: (%rax + 4*%rcx + 24) and store in %rdx

Question 48

Is this valid Leal 24(%eax, %ecx, 4), %edx

Answer 48

Yes

Question 49

Only ___ and ___ suffix work with lea instruction in x86-64

Answer 49

Q,l

Question 51

What registers are valid for Rob (base register)

Answer 51

Any of the 16 registers