On Thu, 21 Nov 2019 at 13:42, Richard Biener <rguent...@suse.de> wrote:
>
> On Thu, 21 Nov 2019, Prathamesh Kulkarni wrote:
>
> > Hi,
> > The issue seems to happen with -O1, because header only contains phi:
> >
> > <bb 3> [local count: 118111600]:
> > # iter.12_9 = PHI <0(2), iter.12_10(10)>
> >
> > and thus we hit segfault in following hunk in find_loop_guard:
> > else
> > {
> > cond = dyn_cast <gcond *> (last_stmt (header));
> > if (! cond)
> > return NULL;
> > extract_true_false_edges_from_block (header, &te, &fe);
> >
> > since last_stmt (header) returns NULL.
> >
> > The attached patch, simply punts if last_stmt returns NULL, which
> > avoids the segfault.
> > Does it look OK ?
>
> Please add the testcase from the PR to gcc.dg/torture
> with dg-additional-options -funswitch-loops.
>
> else
> {
> - cond = dyn_cast <gcond *> (last_stmt (header));
> + gimple *last = last_stmt (header);
> + if (!last)
> + return NULL;
> + cond = dyn_cast <gcond *> (last);
> if (! cond)
> return NULL;
>
> Please simply use safe_dyn_cast <gcond *> (last_stmt (header))
> which appropriately deals with a NULL input.
>
> OK with those changes.
Thanks for the suggestions, I committed the patch in r278598 with the
above changes
and verifying bootstrap+test passes on x86_64-unknown-linux-gnu.
Thanks,
Prathamesh
> Richard.
