[gcc r14-4522] Fixes for profile count/probability maintenance

[Eugene Rozenfeld]

https://gcc.gnu.org/g:cc50337215535e17f1caa5eae34eaa650223c96b

commit r14-4522-gcc50337215535e17f1caa5eae34eaa650223c96b
Author: Eugene Rozenfeld <erozen@microsoft.com>
Date:   Fri Sep 15 18:12:47 2023 -0700

    Fixes for profile count/probability maintenance
    
    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.
    
    Tested on x86_64-pc-linux-gnu.
    
    gcc/ChangeLog:
            * auto-profile.cc (afdo_calculate_branch_prob): Fix count comparisons
            * tree-vect-loop-manip.cc (vect_do_peeling): Guard against zero count
            when scaling loop profile

Diff:
---
 gcc/auto-profile.cc         | 4 ++--
 gcc/tree-vect-loop-manip.cc | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/gcc/auto-profile.cc b/gcc/auto-profile.cc
index ff3b763945c..e75b0469374 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.nonzero_p())
       {
 	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.nonzero_p())
     {
       /* Calculate, propagate count and probability information on CFG.  */
       afdo_calculate_branch_prob (&annotated_bb);
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