[gcc r13-6666] ipa-cp: Fix various issues in update_specialized_profile (PR 107925)

[Martin Jambor]

https://gcc.gnu.org/g:68ba253bda74d6c6e77726d98184a6faee5e7337

commit r13-6666-g68ba253bda74d6c6e77726d98184a6faee5e7337
Author: Martin Jambor <mjambor@suse.cz>
Date:   Tue Mar 14 18:53:16 2023 +0100

    ipa-cp: Fix various issues in update_specialized_profile (PR 107925)
    
    The patch below fixes various issues in function
    update_specialized_profile.  The main is removal of the assert which
    is bogus in the case of recursive cloning.  The division of
    unexplained counts is guesswork, which then leads to updates of counts
    of recursive edges, which then can be redirected to the new clone and
    their count subtracted from the count and there simply may not be
    enough left in the count of the original node - especially when we
    clone a lot because of using --param ipa-cp-eval-threshold=1.
    
    The other issue was omission to drop the count of the original node to
    ipa count.  And when calculating the remainder, we should use
    lenient_count_portion_handling to account for partial train runs.
    Finally, the patch adds dumping of the original count which I think
    is useful.
    
    gcc/ChangeLog:
    
    2023-02-17  Martin Jambor  <mjambor@suse.cz>
    
            PR ipa/107925
            * ipa-cp.cc (update_specialized_profile): Drop orig_node_count to
            ipa count, remove assert, lenient_count_portion_handling, dump
            also orig_node_count.

Diff:
---
 gcc/ipa-cp.cc | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/gcc/ipa-cp.cc b/gcc/ipa-cp.cc
index 4b8dedc0c51..5a6b41cf2d6 100644
--- a/gcc/ipa-cp.cc
+++ b/gcc/ipa-cp.cc
@@ -5093,22 +5093,24 @@ update_specialized_profile (struct cgraph_node *new_node,
 			    profile_count redirected_sum)
 {
   struct cgraph_edge *cs;
-  profile_count new_node_count, orig_node_count = orig_node->count;
+  profile_count new_node_count, orig_node_count = orig_node->count.ipa ();
 
   if (dump_file)
     {
       fprintf (dump_file, "    the sum of counts of redirected  edges is ");
       redirected_sum.dump (dump_file);
+      fprintf (dump_file, "\n    old ipa count of the original node is ");
+      orig_node_count.dump (dump_file);
       fprintf (dump_file, "\n");
     }
   if (!(orig_node_count > profile_count::zero ()))
     return;
 
-  gcc_assert (orig_node_count >= redirected_sum);
-
   new_node_count = new_node->count;
   new_node->count += redirected_sum;
-  orig_node->count -= redirected_sum;
+  orig_node->count
+    = lenient_count_portion_handling (orig_node->count - redirected_sum,
+				      orig_node);
 
   for (cs = new_node->callees; cs; cs = cs->next_callee)
     cs->count += cs->count.apply_scale (redirected_sum, new_node_count);