On Thu, 13 Nov 2025, Andrew Pinski wrote:
> On Thu, Nov 13, 2025 at 12:17 PM Andrew Pinski
> <[email protected]> wrote:
> >
> > On Thu, Nov 13, 2025 at 6:01 AM Richard Biener <[email protected]> wrote:
> > >
> > > We currently remove stmts inside of a FOR_EACH_IMM_USE_STMT iteration
> > > which can be problematical. The following adjusts purge_all_uses
> > > to gather all stmts to remove and remove them in reverse order
> > > afterwards which also better deals with debug stmt generation.
> > >
> > > Bootstrapped and tested on x86_64-unknown-linux-gnu.
> > >
> > > OK?
> >
> > LGTM but I can't approve it.
>
> Just FYI, I added a smallish (23 lines) testcase to the bug report
> which should be small enough to add to the testsuite too.
Now pushed with that added as testcase.
Richard.
> Thanks,
> Andrew
>
> >
> > >
> > > Thanks,
> > > Richard.
> > >
> > > PR ipa/122663
> > > * ipa-param-manipulation.cc (purge_all_uses): Collect
> > > stmts to remove and process that list in reverse.
> > > ---
> > > gcc/ipa-param-manipulation.cc | 13 +++++++++++--
> > > 1 file changed, 11 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/gcc/ipa-param-manipulation.cc b/gcc/ipa-param-manipulation.cc
> > > index 11f843c48d1..96ab125dee1 100644
> > > --- a/gcc/ipa-param-manipulation.cc
> > > +++ b/gcc/ipa-param-manipulation.cc
> > > @@ -636,6 +636,7 @@ purge_all_uses (tree name, hash_set <tree>
> > > *killed_ssas)
> > > imm_use_iterator imm_iter;
> > > gimple *stmt;
> > > auto_vec <tree, 4> worklist;
> > > + auto_vec <gimple *, 4> kill_list;
> > >
> > > worklist.safe_push (name);
> > > while (!worklist.is_empty ())
> > > @@ -664,11 +665,19 @@ purge_all_uses (tree name, hash_set <tree>
> > > *killed_ssas)
> > > if (!killed_ssas->add (lhs))
> > > {
> > > worklist.safe_push (lhs);
> > > - gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
> > > - gsi_remove (&gsi, true);
> > > + kill_list.safe_push (stmt);
> > > }
> > > }
> > > }
> > > +
> > > + /* Remove stmts in reverse and afterwards to properly handle debug stmt
> > > + generation and to not interfere with immediate use iteration. */
> > > + while (!kill_list.is_empty ())
> > > + {
> > > + stmt = kill_list.pop ();
> > > + gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
> > > + gsi_remove (&gsi, true);
> > > + }
> > > }
> > >
> > > /* Modify actual arguments of a function call in statement currently
> > > belonging
> > > --
> > > 2.51.0
>
--
Richard Biener <[email protected]>
SUSE Software Solutions Germany GmbH,
Frankenstrasse 146, 90461 Nuernberg, Germany;
GF: Jochen Jaser, Andrew McDonald, Werner Knoblich; (HRB 36809, AG Nuernberg)
