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Re: GCC 4.1.0 Released


On Wed, Mar 01, 2006 at 04:05:16PM -0800, H. J. Lu wrote:
> On Wed, Mar 01, 2006 at 03:06:46PM -0800, Mark Mitchell wrote:
> > H. J. Lu wrote:
> > 
> > > Here are diffs of "-O2 -mtune=nocona -ffast-math" vs
> > > "-O2 -mtune=generic -ffast-math" on Nocona:
> > 
> > A 1.5% performance improvement, while certainly significant for some
> > users, is not worth taking any serious risks on a release branch.  The
> 
> You are comparing apply with orange. If a user uses -O2, he/she will
> see much more than that.

I meant to say "comparing apple with orange".

> 
> > 
> > The first step is to address regressions on the mainline.  I have not
> > myself verified the claim, but there has been a suggestion that there is
> > at least one open regression due to the patch.  If there are any known
> > regressions from the patch, it's certainly not eligible for a backport.
> 
> I am only aware of
> 
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26146
> 
> and I have a patch. BTW, I don't think it is a real regression, just
> a latent bug. I doubt
> 
> # configure i[456]86-pc-solaris2.10
> # onfigure --with-cpu=i[3456]86 i386-pc-solaris2.10
> 
> had ever worked.
> 
> In any case, please CC me any -mtune=generic patch.

Let me rephrase, please CC me any -mtune=generic related bugs.


H.J.


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