Some thoughts about steerring commitee work

[Dorit Nuzman]

> On Fri, Jun 15, 2007 at 06:21:53PM -0700, Ian Lance Taylor wrote:
> >
> > This is hardly a new thought, but I believe that for the i386 gcc is
> > handicapped by reload.  No matter how smart we are before reload, it
> > just take one poor decision by reload in an inner loop and we've lost
> > all the gains.  Reload has enormous complexities which are mostly
> > irrelevant for the i386.  And I think that the idea of doing register
> > allocation separately from spill code generation does not make sense
> > on the i386.
> >
>
> Why don't we turn on vectorizer at -O3 or even -O2, depending on
> ISA?

I think we want to make more progress on the cost model first, so that we
don't greedily vectorize unless we think it's worth while.

> I added -ftree-vectorize to BOOT_CFLAGS on x86-64. According to
> -ftree-vectorizer-verbose=1, there are 82 loops vectorized in
> gcc source. There are no regressions. There are not much changes
> in bootstrap time as well as "make check" time.
>

that's good to know,

dorit

>
> H.J.