On Fri, 23 Oct 2015, Tom de Vries wrote:
> [ was: Re: [PATCH][PR67671] Handle restrict pointer references as restrict in
> AA ]
>
> On 22/09/15 16:02, Richard Biener wrote:
> > On Tue, 22 Sep 2015, Tom de Vries wrote:
> >
> > > >Hi,
> > > >
> > > >Consider this test-case:
> > > >...
> > > >struct ps
> > > >{
> > > > int *__restrict__ p;
> > > >};
> > > >
> > > >f (struct ps &__restrict__ ps1)
> > > >{
> > > > *(ps1.p) = 1;
> > > >}
> > > >...
> > > >
> > > >Atm (meaning after the fix for PR67666) for this test-case, we register
> > > two
> > > >clique/base annotations, one for the load of pointer ps1.p and one for
> > > the
> > > >store to that pointer:
> > > >...
> > > >void f(ps&) (struct psD.2252 & restrict ps1D.2255)
> > > >{
> > > > intD.9 * _3;
> > > >
> > > > # VUSE <.MEM_1(D)>
> > > > # PT = { D.2262 } (nonlocal)
> > > > _3 = MEM[(struct psD.2252 &)ps1_2(D) clique 1 base 1].pD.2254;
> > > >
> > > > # .MEM_4 = VDEF <.MEM_1(D)>
> > > > MEM[(intD.9 *)_3 clique 1 base 2] = 1;
> > > >...
> > > >
> > > >
> > > >If we rewrite the test-case by replacing the struct with its only field,
> > > we
> > > >get:
> > > >...
> > > >f (int *__restrict__ &__restrict__ p)
> > > >{
> > > > *p = 1;
> > > >}
> > > >...
> > > >
> > > >However, in this case, we register only one clique/base annotation, for
> > > the
> > > >load of pointer p, but not for the store to pointer p:
> > > >...
> > > >void f(int* __restrict__&) (intD.9 * restrict & restrict pD.2255)
> > > >{
> > > > intD.9 * _3;
> > > >
> > > > # VUSE <.MEM_1(D)>
> > > > # PT = nonlocal escaped
> > > > _3 = MEM[(intD.9 * restrict &)p_2(D) clique 1 base 1];
> > > >
> > > > # .MEM_4 = VDEF <.MEM_1(D)>
> > > > *_3 = 1;
> > > >...
> > > >
> > > >
> > > >This patch makes sure we register both clique/base annotations for the
> > > the
> > > >second example.
> > > >
> > > >Bootstrapped and reg-tested on x86_64.
> > > >
> > > >OK for trunk?
> > Ok.
>
> Hi,
>
> I think that after the committed change for PR67671, we arrive here in
> intra_create_variable_infos with p->only_restrict_pointers == 1 and p->next ==
> 0:
> ...
> if (POINTER_TYPE_P (TREE_TYPE (t))
> && TYPE_RESTRICT (TREE_TYPE (t)))
> make_constraint_from_global_restrict (p, "PARM_RESTRICT");
> ...
>
> In other words, we get the same effect if we enter the else branch:
> ...
> else
> {
> for (; p; p = vi_next (p))
> {
> if (p->only_restrict_pointers)
> make_constraint_from_global_restrict (p, "PARM_RESTRICT");
> else if (p->may_have_pointers)
> make_constraint_from (p, nonlocal_id);
> }
> }
> ...
>
> So, I think we can remove the if branch. Attached patch implements that.
>
> OK for trunk if bootstrap/reg-test succeeds?
Ok
Richard.
> Thanks,
> - Tom
>
>
--
Richard Biener <[email protected]>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
