Hi,
On Sat, Jul 25 2020, Sergei Trofimovich wrote:
> From: Sergei Trofimovich <siarh...@google.com>
>
> In PR ipa/96291 the test contained an SCC with one
> unoptimized function. This tricked ipa-cp into NULL dereference.
>
> has_undead_caller_from_outside_scc_p() did not take into account
> that unoptimized funtions don't have IPA summary analysis. and
> dereferenced NULL pointer causing an ICE.
>
> PR ipa/96291
> * ipa-cp.c (has_undead_caller_from_outside_scc_p): Consider
> unoptimized callers as undead.
> ---
> gcc/ipa-cp.c | 12 +++++++++---
> 1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/gcc/ipa-cp.c b/gcc/ipa-cp.c
> index b0c8f405260..d5082576962 100644
> --- a/gcc/ipa-cp.c
> +++ b/gcc/ipa-cp.c
> @@ -5666,9 +5666,15 @@ has_undead_caller_from_outside_scc_p (struct
> cgraph_node *node,
> && cs->caller->call_for_symbol_thunks_and_aliases
> (has_undead_caller_from_outside_scc_p, NULL, true))
> return true;
> - else if (!ipa_edge_within_scc (cs)
> - && !IPA_NODE_REF (cs->caller)->node_dead)
> - return true;
> + else if (!ipa_edge_within_scc (cs))
> + {
> + /* Unoptimized callers don't have IPA information.
> + Conservatively assume callers are undead. */
> + if (!IPA_NODE_REF (cs->caller))
> + return true;
> + if (!IPA_NODE_REF (cs->caller)->node_dead)
> + return true;
I'd prefer a single condition, i.e.:
else if (!ipa_edge_within_scc (cs)
&& (!IPA_NODE_REF (cs->caller)
|| !IPA_NODE_REF (cs->caller)->node_dead))
return true;
so OK with that change.
Thanks a lot for looking into this.
Martin
