On 2/18/07, Daniel Berlin <[EMAIL PROTECTED]> wrote:
On 2/17/07, H. J. Lu <[EMAIL PROTECTED]> wrote:
> On Sat, Feb 17, 2007 at 01:35:28PM +0300, Vladimir Sysoev wrote:
> > Hello, Daniel
> >
> > It looks like your changeset listed bellow makes performance
> > regression ~40% on SPEC2006/leslie3d. I will try to create minimal
> > test for this issue this week and update you in any case.
> >
>
> That is a known issue:
>
> http://gcc.gnu.org/ml/gcc/2007-01/msg00408.html
Yes, it is something we sadly cannot do anything about without doing a
very large number of backports.
There were some seriously broken things in 4.2's aliasing that got
fixed properly in 4.3.
The price of fixing them in 4.2 was a serious performance drop.
There's the option of un-fixing them to get back to the state of 4.1 declaring
them fixed in 4.3 earliest.
Richard.
