> Hi,
>
> Looking into the behavior of profile count updating in PR 107925, I
> noticed that an option not considered possible was actually happening,
> and - with the guesswork in place to distribute unexplained counts -
> it simply can happen. Currently it is handled by dropping the counts
> to local estimated zero, whereas it is probably better to leave the
> count as they are but drop the category to GUESSED_GLOBAL0 - which is
> what profile_count::combine_with_ipa_count in a similar case (or so I
> hope :-)
>
> Profiled-LTO-bootstrapped and normally bootstrapped and tested on an
> x86_64-linux. OK for master once stage1 opens up? Or perhaps even now?
>
> Thanks,
>
> Martin
>
>
> gcc/ChangeLog:
>
> 2023-02-20 Martin Jambor <[email protected]>
>
> PR ipa/107925
> * ipa-cp.cc (update_profiling_info): Drop counts of orig_node to
> global0 instead of zeroing when it does not have as many counts as
> it should.
OK,
thanks!
Honza
> ---
> gcc/ipa-cp.cc | 29 ++++++++++++++++++++++-------
> 1 file changed, 22 insertions(+), 7 deletions(-)
>
> diff --git a/gcc/ipa-cp.cc b/gcc/ipa-cp.cc
> index 5a6b41cf2d6..6477bb840e5 100644
> --- a/gcc/ipa-cp.cc
> +++ b/gcc/ipa-cp.cc
> @@ -4969,10 +4969,20 @@ update_profiling_info (struct cgraph_node *orig_node,
> false);
> new_sum = stats.count_sum;
>
> + bool orig_edges_processed = false;
> if (new_sum > orig_node_count)
> {
> - /* TODO: Perhaps this should be gcc_unreachable ()? */
> - remainder = profile_count::zero ().guessed_local ();
> + /* TODO: Profile has alreay gone astray, keep what we have but lower it
> + to global0 category. */
> + remainder = orig_node->count.global0 ();
> +
> + for (cgraph_edge *cs = orig_node->callees; cs; cs = cs->next_callee)
> + cs->count = cs->count.global0 ();
> + for (cgraph_edge *cs = orig_node->indirect_calls;
> + cs;
> + cs = cs->next_callee)
> + cs->count = cs->count.global0 ();
> + orig_edges_processed = true;
> }
> else if (stats.rec_count_sum.nonzero_p ())
> {
> @@ -5070,11 +5080,16 @@ update_profiling_info (struct cgraph_node *orig_node,
> for (cgraph_edge *cs = new_node->indirect_calls; cs; cs = cs->next_callee)
> cs->count = cs->count.apply_scale (new_sum, orig_new_node_count);
>
> - profile_count::adjust_for_ipa_scaling (&remainder, &orig_node_count);
> - for (cgraph_edge *cs = orig_node->callees; cs; cs = cs->next_callee)
> - cs->count = cs->count.apply_scale (remainder, orig_node_count);
> - for (cgraph_edge *cs = orig_node->indirect_calls; cs; cs = cs->next_callee)
> - cs->count = cs->count.apply_scale (remainder, orig_node_count);
> + if (!orig_edges_processed)
> + {
> + profile_count::adjust_for_ipa_scaling (&remainder, &orig_node_count);
> + for (cgraph_edge *cs = orig_node->callees; cs; cs = cs->next_callee)
> + cs->count = cs->count.apply_scale (remainder, orig_node_count);
> + for (cgraph_edge *cs = orig_node->indirect_calls;
> + cs;
> + cs = cs->next_callee)
> + cs->count = cs->count.apply_scale (remainder, orig_node_count);
> + }
>
> if (dump_file)
> {
> --
> 2.39.1
>
