Assembly Part 7

Question 1

Arrays store multiple data objects of______ _______

Answer 1

Same type

Question 2

Store sequentially, often accessed as an offset from a pointer which points to _______

Answer 2

Beginning of array

Question 3

T A[L]

Continuously allocation region of ________ bytes in memory

Answer 3

L*sizeof(T) in memory

Question 4

Static isn’t array[30];
Static int x = array[25]

$ in assembly language with a label gives an address. Array and x must have been define in the ______ section (.data) of the program

Answer 4

Data

Question 5

In x86-64, memory to memory moves are _____ allowed

Answer 5

NOT

Question 6

Int data[20];
How to allocate space for this on the stack??

Answer 6

Subq $80, %rsp. //allocate space on the stack
Leaq (%rsp), %rax //using rax as the base register for the array. So rax stores address of first element in array

Question 7

Stack clean up before return example

Question 8

How to allocate space of the stack

Answer 8

We need to subtract the size of the array from the stack
Then we need to store the address of top of the array to some other register (Leaq (%rsp), %rax)

Question 9

What happens if an array holds elements larger than 1 byte? Ex: array of structures were each structure is 20 bytes
Want to access 5th element

Answer 9

Movq $5, %rcx
Imulq $20, %rax, %rax

Suppose we want &arr[5]
Leaq (%rbx, %rax), %rdx