Serious performance regression -- some tree optimizer questions

[Daniel Berlin]

On Wed, 12 Jan 2005, Daniel Berlin wrote:

>
>
> On Wed, 12 Jan 2005, Ulrich Weigand wrote:
>
>> Daniel Berlin <dberlin@dberlin.org> wrote on 12/20/2004 01:25:49 AM:
>> 
>>> If you find it helps other testcases, or whatever, i'm happy to try to
>>> explore making that patch usable.
>> 
>> OK, the current situation w.r.t. mgrid is as follows:
>> 
>> With unmodified GCC, mgrid on 31-bit generates bad code due to a
>> combination of the problem fixed by your patch and IV selection
>> issues.  On 64-bit, the problem addressed by your patch doesn't
>> occur, but we have problems due to IV sign-extension (and also
>> IV selection issues).
>
> Ivopts is become large.
<...>

Even with all of these caveats, however, i should note that i still 
believe the various patches to fix these performance regressions very 
much need to be considered for 4.0.