Re: Patches ping

[Zdenek Dvorak <rakdver at atrey dot karlin dot mff dot cuni dot cz>]

Hello,

> >>>I don't know what the issue was. You can see it yourself if you  
> >>>apply
> >>>the patch. basically, at the end of the vectorizing pass, there are
> >>>statements which if you call update_stmt() on them, they get a
> >>>different
> >>>set of operands. This means they needed to be updated during the  
> >>>pass
> >>>because they are out of date when the pass is over.
> >>>
> >>
> >>I thought this was addressed by,
> >>    http://gcc.gnu.org/ml/gcc/2005-04/msg00848.html
> >>
> >>This thread started at
> >>    Semi-Latent Bug in tree vectorizer
> >>    http://gcc.gnu.org/ml/gcc/2005-04/msg00382.html
> >>
> >
> >obviously, that was a different bug.
> 
> Well, I wanted to know what is "the known problem for about a month" ?
> This was the only thing I knew and it looked similar. So, I appreciate
> pointers for earlier discussions you referred above.

http://gcc.gnu.org/ml/gcc-patches/2005-04/msg01360.html

I did not really try to analyze the problem very much.  I just looked at
the problem, noticed that it is different from the one fixed by the
Jeff's patch (because it was not fixed by the patch and the symptoms are
quite different -- there are no "forgotten" virtual operands, just the
aliasing info on pointers is set up in a wrong way), and that I don't
immediatelly see where precisely is the problem in vectorizer (although
I suspect that the cause is that it somewhere just calls
copy_virtual_operands instead of updating the statement properly).

http://gcc.gnu.org/ml/gcc-patches/2005-04/msg01567.html

So I wrote the verifier and hoped that someone who understands the way
vectorizer is trying to update the virtual operands will fix that.

Zdenek