Editing Loop unrolling (section)

=== Unrolling WHILE loops ===
Consider a pseudocode WHILE loop similar to the following:

{| class="wikitable"
!Normal loop
!After loop unrolling
!Unrolled & "tweaked" loop
|-style="vertical-align:top"
|
 WHILE (condition) DO
     action
 ENDWHILE
 .
 .
 .
 .
 .
 .
|
 WHILE (condition) DO
     action
     IF NOT(condition) THEN GOTO break
     action
     IF NOT(condition) THEN GOTO break
     action
 ENDWHILE
 LABEL break:
 .
|
 IF (condition) THEN
     REPEAT
         action
         IF NOT(condition) THEN GOTO break
         action
         IF NOT(condition) THEN GOTO break
         action
     WHILE (condition)
 LABEL break:
|}
In this case, unrolling is faster because the ENDWHILE (a jump to the start of the loop) will be executed 66% less often.

Even better, the "tweaked" pseudocode example, that may be performed automatically by some optimizing compilers, eliminating unconditional jumps altogether.