From: acolvin@efunct.com   
      
   >> I found following intermediate codes are generated in gcc   
   >>   
   >> rx <- 0   
   >> ...   
   >> use rx   
   >> ...   
   >> ry <- 0   
   >> use ry   
   >> ...   
      
   This may be "rematerialization", which probably has other names.   
      
   Sometimes it's better to re-compute a common value than to tie up a   
   register. This may well be true for a constant 0 if there are few registers   
   (x86-32).   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)