Re: [lno] Avoid use of rewrite_ssa_into_ssa in loop header copying

[Daniel Berlin <dberlin at dberlin dot org>]

On Jul 17, 2004, at 10:02 PM, Zdenek Dvorak wrote:

> Hello,
>
> > > > > I almost think this is a bug in your code rather than PRE.
> > > >
> > > > 	This is a bug in Zdenek's code.
> > >
> > > an you know that how?
> > >
> > > > Zdenek, please do not commit your patch to the LNO branch.
> > >
> > > I already did.  If someone says me where the bug is, I will be happy 
> > > to
> > > fix it (and since the patch does not cause any problems except with
> > > PRE which nobody on works on on LNO branch, I am not going to revert
> > > it).
> >
> > Yes, I also think this is okay.  Maybe we should merge into LNO the
> > changes from mainline where PRE has changed quite well in the last
> > time...  Hopefully the merge will fix the problems with PRE.
>
> probably not; Steven helped me already to merge the mainline changes
> the last time there were the problems with the PRE.

When was this?
The old value numbering was somewhat broken in some odd corner cases, 
and is no longer.
The stuff on the lno branch still uses the old value numbering.

>  Unfortunately the
> new PRE problem seems to be in part written by Daniel with that Steven
> is not familiar (and he is quite busy at the moment), so it may take 
> him
> some time to analyze the problem.


I'll try to analyze it.
Do you have a .i file i can use?


> Zdenek