This is the mail archive of the
mailing list for the GCC project.
Re: [tree-ssa]: Dominator opts change LHS without changing VDEF's
On Sun, 10 Aug 2003, Diego Novillo wrote:
> On Sun, 2003-08-10 at 16:35, Daniel Berlin wrote:
> > Diego, this is the bitmap.i problem i sent you.
> > This is only visible with points-to on, because it better disambiguates.
> > The problem is that dominator opts changes:
> > # MT.564_34 = VDEF <MT.564_33>;
> > # VUSE <bitmap_free_32>;
> > elt_29->next = (struct bitmap_element_def *)bitmap_free
> > into
> > elt_7->next = (struct bitmap_element_def *)bitmap_free
> > This causes the vdef's to changes, because the memory tag for elt isn't
> > the same as elt.
> They aren't?
> Both variables are aliased, are they not?
They also have different aliasing properties.
Variable: elt, memory tag: MT.564, may point to global memory, is stored
Variable: elt, memory tag: MT.558, may point to global memory
> If so, they
> should have the same memory tag.
You wrote this stuff, not me.