For-loop in
C:
for(int x = 0; x<=3;
x++)
{
//Do
something!
}
The same
loop in 8086 assembler:
xor cx,cx ;
cx-register is the counter, set to 0
loop1 nop ; Whatever you wanna do goes
here, should not change cx
inc cx ; Increment
cmp cx,3 ; Compare
cx to the limit
jle loop1 ; Loop while less or
equal
That is the loop if you
need to access your index (cx). If you just wanna to something 0-3=4 times but you do
not need the index, this would be easier:
mov cx,4 ; 4 iterations
loop1 nop ; Whatever you wanna do goes here, should
not change cx
loop loop1 ; loop instruction decrements cx and jumps to label
if not 0
If you just want to
perform a very simple instruction a constant amount of times, you could also use an
assembler-directive which will just hardcore that
instruction
times 4
nop
Do-while-loop in
C:
int x=1;
do{
//Do
something!
}
while(x==1)
The
same loop in assembler:
mov
ax,1
loop1 nop ; Whatever you wanna do goes here
cmp ax,1 ; Check
wether cx is 1
je loop1 ; And loop if
equal
While-loop in
C:
while(x==1){
//Do
something
}
The same
loop in assembler:
jmp loop1 ; Jump to
condition first
cloop1 nop ; Execute the content of the loop
loop1
cmp ax,1 ; Check the condition
je cloop1 ; Jump to content of the loop if
met
For the for-loops you should
take the cx-register because it is pretty much standard. For the other loop conditions
you can take a register of your liking. Of course replace the no-operation instruction
with all the instructions you wanna perform in the loop.
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