I think cmp has some problems with handling signed (negative) integers. What am I doing wrong? The following code is for DOS:
org 100h
mov ecx,-3
neg ecx
mov edx,5
cmp ecx,edx
ja @f
mov ah,2
mov dl,1
int 21h
@@:
int 20h
If ecx is smaller than edx (-3 smaller than 5), the ASCII-Code 1 (a smiley
) will be drawn. This works, because actually it GETS drawn
But now, the with the following code, the smiley won't get drawn! I just changed -3 into -8.
org 100h
mov ecx,-8
neg ecx
mov edx,5
cmp ecx,edx
ja @f
mov ah,2
mov dl,1
int 21h
@@:
int 20h
So I think cmp cannot handle signed integers at all. Maybe the first code worked because even without the sign, 3 is still smaller than 5. But when the sign of -8 is taken away, 8 will be greater than 5.
So how to handle signed integervalues with cmp?
Thank you...
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> Main > Comparing signed integers
03 Feb 2005, 23:35
