[lno] "no flow-sensitive alias info" warning to vectorizer

[Zdenek Dvorak]

Hello,

> > > > for the following vectorized tree sequence:
> > > > 
> > > > 1  vect_pX.1_11 = &X;
> > > > 2  vect_iv_.3_12 = vect_iv_.2_15;
> > > > 3  vect_iv_.4_13 = vect_iv_.3_12 * 16;
> > > > 4  vect_pX.5_14 = vect_pX.1_11 + vect_iv_.4_13;
> > > > 5  *vect_pX.5_14 = vect_cst_.6_18;
> > > > 
> > > > Currently, I only set 'type_mem_tag' to vectorizer generated pointers,
> > > > using:
> > > > 
> > > > get_var_ann (ptr)->type_mem_tag = array_base;
> > > > 
> > > Hmm, it would be better if you can call the alias analyzer to set memory
> > > tags.
> > 
> > how exactly?  I also use similar hacks on about two places.
> > 
> As I said at the end of my message, by scheduling another
> compute_may_aliases pass.  Let me know if you run into trouble or things
> don't work as expected.  In theory it should just work, but I still
> haven't tested multiple passes of the alias analyzer.

would not there be some simpler possibility?  I do not really change
anything that should concern aliasing, I just change the way the address
of the memory reference is computed (in strength reduction).

Zdenek