[Bug tree-optimization/46590] [4.5/4.6 Regression] long compile time with -O2 and many loops

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46590

--- Comment #11 from Richard Guenther <rguenth at gcc dot gnu.org> 2010-11-22 
16:19:37 UTC ---
(In reply to comment #10)
> At -O1 we have
> 
>  tree SSA rewrite      :  23.32 (13%) usr   0.06 ( 3%) sys  22.80 (13%) wall  
>  
> 6392 kB ( 3%) ggc
>  tree SSA incremental  :  24.05 (14%) usr   0.07 ( 4%) sys  25.27 (14%) wall  
>  
> 3533 kB ( 2%) ggc

The above is almost completely loop header copying.