[MPlayer-users] Re: Strange option. -O4

[Anssi Saari]

On Wed, Dec 25, 2002 at 01:56:12PM +0100, Jens Axboe wrote:

> > if -O3 enables all possible opts, then -O4 probably enables impossible ones
> > too :)
> 
> has any benchmarking been done whether that is truly a good idea or not?
> levels above 2 does automatic loop unrolling 

Does it really? At least my understanding of the gcc manual isn't that. 
It seems to me one would always need to enable loop unrolling with 
-funroll-loops or -funroll-all-loops.