From: terje.mathisen@nospicedham.tmsw.no   
      
   Melzzzzz wrote:   
   > I have following code snippet:   
   >   
   >     cmp r9,1   
   >     je .one   
   >     add rdi,r9   
   >     sub rdx,r9   
   >     jmp .L0   
   > .one:   
   >     inc rdi   
   >     dec rdx   
   >     jmp .L0   
   >   
   > For some reason I did it like that and it seems that doesn't hurt, but   
   > gives significant boost in some cases?   
   > Am I doing it wrong or is this good practice?   
   >   
   That looks _really_ bad!   
      
   You must be hitting some weird interations, maybe with cache line   
   alignments?   
      
   The ADD and SUB instructions should never take more than a single cycle,   
   while the branch can miss and INC/DEC could also be slower than ADD/SUB   
   due to the need to specialcase the carry flag. (But no cpu version I   
   know about will actually run INC/DEC slower...)   
      
   Terje   
      
   --   
   -    
   "almost all programming can be viewed as an exercise in caching"   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)