Difference between revisions of "Assembly Language IF ELSE"

From TRCCompSci - AQA Computer Science
Jump to: navigation, search
(Created page with "==C# example== <syntaxhighlight lang=csharp> int y = 0; int x = 0; if (y == 10) { x = 9; } else { y++ } </syntaxhighlight> ==Assembly Version== LDR R0, #0 L...")
 
(Assembly Version)
Line 16: Line 16:
 
==Assembly Version==
 
==Assembly Version==
  
     LDR R0, #0
+
     MOV R0, #0
     LDR R1, #0
+
     MOV R1, #0
 
     CMP R0, #10
 
     CMP R0, #10
 
     BNE .else
 
     BNE .else

Revision as of 12:17, 21 January 2020

C# example

int y = 0;
int x = 0;
if (y == 10)
{
    x = 9;
}
else
{
    y++
}

Assembly Version

   MOV R0, #0
   MOV R1, #0
   CMP R0, #10
   BNE .else
   MOV R1, #9
   B .endif
.else
   ADD R0, R0, #1
.endif


Line 1 sets the value of Register 0 to the value 0.
Line 2 sets the value of Register 1 to the value 0.
Line 3 compares the value in Register 0 with the value 10.
Line 4 will branch to the .else label if the previous compare was NOT EQUAL.
Line 5 will move the value 9 into Register 1.
Line 6 will branch always to the .endif label.
Line 7 is a label called .else and is used in a branch.
Line 8 will add together the value 1 with the current value in Register 0, the output will be stored back in Register 0.