Re: PATCH: PR 16590

[Mark Mitchell <mark at codesourcery dot com>]

Jeffrey A Law wrote:

> On Tue, 2004-08-31 at 00:31, Mark Mitchell wrote:
>  
>
> > Jeffrey A Law wrote:
> >
> >    
> >
> > > On Sun, 2004-08-29 at 13:41, Mark Mitchell wrote:
> > >
> > >
> > >      
> > >
> > > > This PR is a case where GCSE creates an invalid REG_EQUAL note.  (More
> > > > details are in the audit trail.)  I asked Jeff Law for his thoughts on
> > > > this patch about ten days ago, but haven't heard back, so I'm going
> > > > ahead and checking this in.
> > > >
> > > > Tested on i686-pc-linux-gnu, applied on the 3.4 branch and on the
> > > > mainline.
> > > >   
> > > >
> > > >        
> > > Sorry, I didn't expect the cross-town move to leave me without an
> > > internet connection for so long.
> > >
> > > I haven't followed all the changes to gcse which arrange for it
> > > to create REG_EQUAL notes.  However, I do know most of those changes
> > > were done in an attempt to improve later optimizations, so it's
> > > possible your change is pessimizing code in some ways.
> > >
> > > But more importantly, I don't see how that REG_EQUAL note is
> > > incorrect.
> > >
> > >      
> > OK, I have reverted the patch on the 3.4 branch and on the mainline.
> >    
> Funny -- the store motion code already has all the bits to find and
> remove REG_EQUAL notes which have become invalid.  A minor bug in
> that code is preventing us from finding the bogus note in this
> particular case.
>
> It'll take several hours to fully test the patch, but I do not
> expect any problems.
>  
Great, thanks.

--
Mark Mitchell
CodeSourcery, LLC
(916) 791-8304
mark@codesourcery.com