[Bug middle-end/38518] Excessive compile time with -O3

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38518

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
With GCC 4.8 we see

 loop invariant motion   :  16.79 (32%) usr   0.02 ( 3%) sys  16.65 (31%) wall 
   148 kB ( 0%) ggc
 loop unswitching        :  10.43 (20%) usr   0.02 ( 3%) sys  10.42 (20%) wall 
     0 kB ( 0%) ggc
 TOTAL                 :  52.07             0.67            53.00            
363360 kB

which is RTL loop optimizers.