Question

I need to implement the following while loop in assembly:

i = 1;

while (i <= 50) {

A[i] = i;

i++;

}

With the array of integers A stored at memory location x+200, where x is the address of the memory location where the assembly program is loaded.

I can only use following commands; LOAD, STORE, ARITHMETIC (ADD, SUB, MUL, DIV, INC), SKIP, BRANCHING (BLT, BGT, BLEQ, BGEQ, BEQ), READ and WRITE, and HALT

Answer 1

Code in C++:-

int i = 1;

int A[51];

while (i <= 50) {

A[i] = i;

i++;

}

Code in Assembaly:-

#Refer Comments for better understanding:-

push rbp

mov rbp, rsp #Setting up stack pointers and base poiniters

sub rsp, 96

mov DWORD PTR [rbp-212], edi #Loading array base address

mov DWORD PTR [rbp-4], 1   #Initialisation of variable i.

.L3:

cmp DWORD PTR [rbp-4], 50 # Condition inside while loop.

jg .L4

mov eax, DWORD PTR [rbp-4]   

cdqe

mov edx, DWORD PTR [rbp-4] #Loading variable i into register edx.

mov DWORD PTR [rbp-208+rax*4], edx   #Assignment at array location A[i]=i.

add DWORD PTR [rbp-4], 1 #Increment of variable i.

jmp .L3 #continue with next iteration.

.L4:

nop

leave

ret