[PATCH] Fixes for profile count/probability maintenance

[Eugene Rozenfeld <Eugene.Rozenfeld@microsoft.com>]

Verifier checks have recently been strengthened to check that
all counts and probabilities are initialized. The checks fired
during autoprofiledbootstrap build and this patch fixes it.

gcc/ChangeLog:

        * auto-profile.cc (afdo_calculate_branch_prob): Fix count comparisons
        * ipa-utils.cc (ipa_merge_profiles): Guard against zero count when
        computing probabilities
        * tree-vect-loop-manip.cc (vect_do_peeling): Guard against zero count
        when scaling loop profile

Tested on x86_64-pc-linux-gnu.

---
 gcc/auto-profile.cc         |  4 ++--
 gcc/ipa-utils.cc            | 16 +++++++++-------
 gcc/tree-vect-loop-manip.cc |  2 +-
 3 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/gcc/auto-profile.cc b/gcc/auto-profile.cc
index ff3b763945c..3e61f36c29b 100644
--- a/gcc/auto-profile.cc
+++ b/gcc/auto-profile.cc
@@ -1434,7 +1434,7 @@ afdo_calculate_branch_prob (bb_set *annotated_bb)
       else
         total_count += AFDO_EINFO (e)->get_count ();
     }
-    if (num_unknown_succ == 0 && total_count > profile_count::zero ())
+    if (num_unknown_succ == 0 && total_count > profile_count::zero ().afdo ())
       {
        FOR_EACH_EDGE (e, ei, bb->succs)
          e->probability
@@ -1571,7 +1571,7 @@ afdo_annotate_cfg (const stmt_set &promoted_stmts)
       DECL_SOURCE_LOCATION (current_function_decl));
   afdo_source_profile->mark_annotated (cfun->function_start_locus);
   afdo_source_profile->mark_annotated (cfun->function_end_locus);
-  if (max_count > profile_count::zero ())
+  if (max_count > profile_count::zero ().afdo ())
     {
       /* Calculate, propagate count and probability information on CFG.  */
       afdo_calculate_branch_prob (&annotated_bb);
diff --git a/gcc/ipa-utils.cc b/gcc/ipa-utils.cc
index 956c6294fd7..3aaf7e595df 100644
--- a/gcc/ipa-utils.cc
+++ b/gcc/ipa-utils.cc
@@ -651,13 +651,15 @@ ipa_merge_profiles (struct cgraph_node *dst,
                {
                  edge srce = EDGE_SUCC (srcbb, i);
                  edge dste = EDGE_SUCC (dstbb, i);
-                 dste->probability =
-                   dste->probability * dstbb->count.ipa ().probability_in
-                                                (dstbb->count.ipa ()
-                                                 + srccount.ipa ())
-                   + srce->probability * srcbb->count.ipa ().probability_in
-                                                (dstbb->count.ipa ()
-                                                 + srccount.ipa ());
+                 profile_count total = dstbb->count.ipa () + srccount.ipa ();
+                 if (total.nonzero_p ())
+                   {
+                     dste->probability =
+                       dste->probability * dstbb->count.ipa ().probability_in
+                                                                       (total)
+                       + srce->probability * srcbb->count.ipa ().probability_in
+                                                                       (total);
+                   }
                }
              dstbb->count = dstbb->count.ipa () + srccount.ipa ();
            }
diff --git a/gcc/tree-vect-loop-manip.cc b/gcc/tree-vect-loop-manip.cc
index 09641901ff1..2608c286e5d 100644
--- a/gcc/tree-vect-loop-manip.cc
+++ b/gcc/tree-vect-loop-manip.cc
@@ -3335,7 +3335,7 @@ vect_do_peeling (loop_vec_info loop_vinfo, tree niters, tree nitersm1,
              free (bbs);
              free (original_bbs);
            }
-         else
+         else if (old_count.nonzero_p ())
            scale_loop_profile (epilog, guard_to->count.probability_in (old_count), -1);

          /* Only need to handle basic block before epilog loop if it's not
--
2.25.1