On Wed, 19 Oct 2016, kugan wrote:
> Hi Richard,
>
>
> On 19/10/16 19:23, Richard Biener wrote:
> > On Wed, 19 Oct 2016, kugan wrote:
> >
> > > Hi,
> > >
> > > While computing jump function value range for pointer, I am wondering if
> > > we
> > > can assume that any tree with ADDR_EXPR will be nonnull.
> > >
> > > That is, in cases like:
> > >
> > > int arr[10];
> > > foo (&arr[1]);
> > >
> > > OR
> > >
> > > struct st
> > > {
> > > int a;
> > > int b;
> > > };
> > > struct st s2;
> > > foo (&s2.a);
> > >
> > > Attached patch tries to do this. I am not sure if this can be wrong. Any
> > > thoughts?
> >
> > It can be wrong for weak symbols for example.
> Would excluding weak symbols (I believe I can check DECL_WEAK for this) good
> enough. Or looking for acceptable subset would work?
I think we should add a symtab helper to tell if address_nonzero_p (if
that doesn't aleady exist).
Richard.
> Thanks,
> Kugan
>
> >
> > Richard.
> >
> > > Attached patch bootstraps and regression testing didn't introduce any new
> > > regressions.
> > >
> > > Thanks,
> > > Kugan
> > >
> > >
> > > gcc/ChangeLog:
> > >
> > > 2016-10-19 Kugan Vivekanandarajah <kug...@linaro.org>
> > >
> > > * ipa-prop.c (ipa_compute_jump_functions_for_edge): Set
> > > value range to nonull for ADDR_EXPR.
> > >
> > > gcc/testsuite/ChangeLog:
> > >
> > > 2016-10-19 Kugan Vivekanandarajah <kug...@linaro.org>
> > >
> > > * gcc.dg/ipa/vrp5.c: New test.
> > > * gcc.dg/ipa/vrp6.c: New test.
> > >
> >
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
