This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: [RFC] Enabling loop unrolls at -O3?
On Sunday 06 November 2005 01:12, Robert Dewar wrote:
> Giovanni Bajo wrote:
> > Steven Bosscher <stevenb@suse.de> wrote:
> >>>I guess the issue is what does "huge" mean, it is hard to discuss based
> >>>on loaded adjectives taking the place of data :-)
> >>
> >>Huge here means 15-20% on x86* hosts.
> >
> > I don't consider this huge for -O3. I think -O3 can be slower if it
> > achieves better code, and -funroll-loops makes it do just that.
>
> I would certainly agree, I am not sure I even find it huge for -O2.
> After all 20% compile time represents a couple of months advance
> in computer hardware (and that is true across the board, even if
> you are talking about upgrading 1990 hardware to 1991 hardware :-))
You must not have been paying attention to one of the most frequent
complaints about gcc, which is that it is dog slow already ;-)
Gr.
Steven