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Re: tree-ssa/lno compute_may_aliases failure
- From: Dorit Naishlos <DORIT at il dot ibm dot com>
- To: Diego Novillo <dnovillo at redhat dot com>
- Cc: Daniel Berlin <dberlin at dberlin dot org>, "gcc at gcc dot gnu dot org" <gcc at gcc dot gnu dot org>
- Date: Thu, 20 May 2004 23:40:01 +0300
- Subject: Re: tree-ssa/lno compute_may_aliases failure
> > (PTA is a prerequisite for compute_may_alias pass).
> >
> No, it is not. Only if you are doing -fpoints-to=andersen. The
> compute_may_alias pass will build flow-sensitive points-to information
> using the SSA form.
So the PROP_pta here is wrong?:
struct tree_opt_pass pass_may_alias =
{
"alias", /* name */
NULL, /* gate */
compute_may_aliases, /* execute */
NULL, /* sub */
NULL, /* next */
0, /* static_pass_number */
TV_TREE_MAY_ALIAS, /* tv_id */
PROP_cfg | PROP_ssa | PROP_pta, /* properties_required */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
TODO_dump_func | TODO_rename_vars
| TODO_ggc_collect | TODO_verify_ssa /* todo_flags_finish */
};
dorit
Diego Novillo
<dnovillo@redhat. To: Dorit Naishlos/Haifa/IBM@IBMIL
com> cc: "gcc@gcc.gnu.org" <gcc@gcc.gnu.org>, Daniel Berlin <dberlin@dberlin.org>
Subject: Re: tree-ssa/lno compute_may_aliases failure
20/05/2004 22:00
On Thu, 2004-05-20 at 14:40, Dorit Naishlos wrote:
> > IIRC PTA cannot be applied once we are in SSA form. That's why you see
> > it sequenced before pass_build_ssa (Dan, has that changed?).
>
> In that case, maybe I should instead postpone delete_pta pass to after
the
> second invocation of compute_may_aliases? (PTA is a prerequisite for
> compute_may_alias pass).
>
No, it is not. Only if you are doing -fpoints-to=andersen. The
compute_may_alias pass will build flow-sensitive points-to information
using the SSA form.
Diego.