This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [patch] Disable tree-ssa DSE for now


On Tue, 2005-01-18 at 22:44 -0800, Mark Mitchell wrote:
> Jeffrey A Law wrote:
> 
> >>I agree.  If the optimizer experts agree that this pass is ineffective, 
> >>Steven's patch should be applied.
> > 
> > It largely depends on what one considers ineffective.  I can say with
> > absolute confidence that the current implementation is able to eliminate
> > stores that the RTL implementation is unable to eliminate.
> 
> That doesn't sound all that ineffective to me, then.  I'm not eager to 
> disable stuff that's doing some good.
Right.  I don't think any of the cases where it's eliminating stores in
GCC itself are on critical paths, but they may be in other codes.  I'll
also note there are some simple things that can be done to make the
existing implementation more effective.

Long term, as Dan mentions, using GVN on the reverse CFG may be a better
solution.

jeff


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]