Hi Martin,
> Honza, is it OK for trunk? Tamar, can you please double check it fixes
> your problem with perlbench?
>
Thanks for working on this! Yes it does seem to fix the regression as well.
Cheers,
Tamar
> Thanks,
>
> Martin
>
>
> ipa-cp: Avoid wrongly gathering self-recursive edges (PR 93707)
>
> 2020-02-18 Martin Jambor <mjam...@suse.cz>
> Feng Xue <f...@os.amperecomputing.com>
>
> PR ipa/93707
> * ipa-cp.c (same_node_or_its_all_contexts_clone_p): Replaced with
> new function calls_same_node_or_its_all_contexts_clone_p.
> (cgraph_edge_brings_value_p): Use it. Fix comment.
> (cgraph_edge_brings_value_p): Likewise.
>
> testsuite/
> * gcc.dg/ipa/pr93707.c: New test.
> ---
> gcc/ChangeLog | 9 +++++++++
> gcc/ipa-cp.c | 29 ++++++++++++++---------------
> gcc/testsuite/ChangeLog | 6 ++++++
> gcc/testsuite/gcc.dg/ipa/pr93707.c | 29
> +++++++++++++++++++++++++++++
> 4 files changed, 58 insertions(+), 15 deletions(-)
> create mode 100644 gcc/testsuite/gcc.dg/ipa/pr93707.c
>
> diff --git a/gcc/ipa-cp.c b/gcc/ipa-cp.c
> index 4f5b72e6994..4609375bf8d 100644
> --- a/gcc/ipa-cp.c
> +++ b/gcc/ipa-cp.c
> @@ -4033,15 +4033,23 @@ edge_clone_summary_t::duplicate
> (cgraph_edge *src_edge, cgraph_edge *dst_edge,
> src_data->next_clone = dst_edge;
> }
>
> -/* Return true is NODE is DEST or its clone for all contexts. */
> +/* Return true is CS calls DEST or its clone for all contexts, except for
> + self-recursive nodes in which it has to be DEST itself. */
>
> static bool
> -same_node_or_its_all_contexts_clone_p (cgraph_node *node,
> cgraph_node *dest)
> +calls_same_node_or_its_all_contexts_clone_p (cgraph_edge *cs,
> cgraph_node *dest)
> {
> - if (node == dest)
> + enum availability availability;
> + cgraph_node *callee = cs->callee->function_symbol (&availability);
> +
> + if (availability <= AVAIL_INTERPOSABLE)
> + return false;
> + if (callee == dest)
> return true;
> + if (cs->caller == callee)
> + return false;
>
> - class ipa_node_params *info = IPA_NODE_REF (node);
> + class ipa_node_params *info = IPA_NODE_REF (callee);
> return info->is_all_contexts_clone && info->ipcp_orig_node == dest;
> }
>
> @@ -4053,11 +4061,8 @@ cgraph_edge_brings_value_p (cgraph_edge *cs,
> ipcp_value_source<tree> *src,
> cgraph_node *dest, ipcp_value<tree> *dest_val)
> {
> class ipa_node_params *caller_info = IPA_NODE_REF (cs->caller);
> - enum availability availability;
> - cgraph_node *real_dest = cs->callee->function_symbol (&availability);
>
> - if (availability <= AVAIL_INTERPOSABLE
> - || !same_node_or_its_all_contexts_clone_p (real_dest, dest)
> + if (!calls_same_node_or_its_all_contexts_clone_p (cs, dest)
> || caller_info->node_dead)
> return false;
>
> @@ -4076,9 +4081,6 @@ cgraph_edge_brings_value_p (cgraph_edge *cs,
> ipcp_value_source<tree> *src,
> }
> else
> {
> - /* At the moment we do not propagate over arithmetic jump functions in
> - SCCs, so it is safe to detect self-feeding recursive calls in this
> - way. */
> if (src->val == dest_val)
> return true;
>
> @@ -4113,11 +4115,8 @@ cgraph_edge_brings_value_p (cgraph_edge *cs,
> ipcp_value<ipa_polymorphic_call_context> *)
> {
> class ipa_node_params *caller_info = IPA_NODE_REF (cs->caller);
> - enum availability avail;
> - cgraph_node *real_dest = cs->callee->function_symbol (&avail);
>
> - if (avail <= AVAIL_INTERPOSABLE
> - || !same_node_or_its_all_contexts_clone_p (real_dest, dest)
> + if (!calls_same_node_or_its_all_contexts_clone_p (cs, dest)
> || caller_info->node_dead)
> return false;
> if (!src->val)
> diff --git a/gcc/testsuite/gcc.dg/ipa/pr93707.c
> b/gcc/testsuite/gcc.dg/ipa/pr93707.c
> new file mode 100644
> index 00000000000..e200a3a432b
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/ipa/pr93707.c
> @@ -0,0 +1,29 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O3 --param ipa-cp-eval-threshold=1" } */
> +
> +int foo();
> +int data[100];
> +
> +__attribute__((noinline)) static int recur_fn (int i, int j, int depth)
> +{
> + if (depth > 10)
> + return 1;
> +
> + data[i + j]++;
> +
> + if (depth & 3)
> + recur_fn (i, 1, depth + 1);
> + else
> + recur_fn (i, j & 1, depth + 1);
> +
> + foo();
> +
> + return i + j;
> +}
> +
> +int caller (int v, int depth)
> +{
> + recur_fn (1, v, depth);
> +
> + return 0;
> +}
> --
> 2.25.0
