[Bug middle-end/37491] [4.4 Regression] Revision 140257 causes vectorizer tests failures

["rguenther at suse dot de" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #10 from rguenther at suse dot de  2008-09-15 09:39 -------
Subject: Re:  [4.4 Regression] Revision 140257 causes
 vectorizer tests failures

On Mon, 15 Sep 2008, irar at il dot ibm dot com wrote:

> 
> 
> ------- Comment #9 from irar at il dot ibm dot com  2008-09-15 09:35 -------
> (In reply to comment #8)
> > Well, I think the ICE happens because for stores we call 
> > vect_create_data_ref_ptr with an explicit vector type which is based on
> > the rhs, not the lhs.  The ICE should never occur if we based the
> > vector type on the lhs.
> 
> No, no. The ICE occurs when we base the vector type on the lhs! 
>   vector void (*<T48f>) (int) * ivtmp.30;
>   vector void (*<T49a>) (int_t) vect_cst_.23;
> 
>   *ivtmp.30_13 = vect_cst_.23_9;
> The rhs and the lhs are not the same (and do not alias).

The rhs ans the lhs do not need to alias.  The important thing is that
the *ivtmp.30_13 aliases the original scalar store - if *ivtmp.30_13
is based on the scalar lhs type this will be always the case.

I am going to have a look myself (not right now, but somewhen this
week) - feel free to assign this bug to me for now.

Thanks,
Richard.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37491