From 7adb06ef209e35c385750dd00e99d57c98063bab Mon Sep 17 00:00:00 2001
From: marxin <mliska@suse.cz>
Date: Fri, 11 Aug 2017 14:04:37 +0200
Subject: [PATCH] Patch candidate.

---
 gcc/predict.c                          | 44 ++++++++++++++++++----------------
 gcc/testsuite/gcc.dg/torture/pr81318.c | 13 ++++++++++
 2 files changed, 37 insertions(+), 20 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/torture/pr81318.c

diff --git a/gcc/predict.c b/gcc/predict.c
index 80c2c1966d8..198fa919d74 100644
--- a/gcc/predict.c
+++ b/gcc/predict.c
@@ -747,8 +747,10 @@ dump_prediction (FILE *file, enum br_predictor predictor, int probability,
 	{
 	  fprintf (file, " hit ");
 	  e->count.dump (file);
-	  fprintf (file, " (%.1f%%)", e->count.to_gcov_type() * 100.0
-		   / bb->count.to_gcov_type ());
+
+	  if (e->count.initialized_p ())
+	    fprintf (file, " (%.1f%%)", e->count.to_gcov_type() * 100.0
+		     / bb->count.to_gcov_type ());
 	}
     }
 
@@ -3446,7 +3448,7 @@ determine_unlikely_bbs ()
           if (dump_file && (dump_flags & TDF_DETAILS))
 	    fprintf (dump_file, "Basic block %i is locally unlikely\n",
 		     bb->index);
-	  bb->count = profile_count::zero ();
+	  bb->count = profile_count::guessed_zero ();
 	}
 
       if (bb->count == profile_count::zero ())
@@ -3463,7 +3465,7 @@ determine_unlikely_bbs ()
             if (dump_file && (dump_flags & TDF_DETAILS))
 	      fprintf (dump_file, "Edge %i->%i is locally unlikely\n",
 		       bb->index, e->dest->index);
-	    e->count = profile_count::zero ();
+	    e->count = profile_count::guessed_zero ();
 	  }
 
       gcc_checking_assert (!bb->aux);
@@ -3503,23 +3505,25 @@ determine_unlikely_bbs ()
 	  if (found)
 	    continue;
 	}
-      if (!(bb->count == profile_count::zero ())
-	  && (dump_file && (dump_flags & TDF_DETAILS)))
-	fprintf (dump_file,
-		 "Basic block %i is marked unlikely by backward prop\n",
-		 bb->index);
-      bb->count = profile_count::zero ();
-      bb->frequency = 0;
-      FOR_EACH_EDGE (e, ei, bb->preds)
-	if (!(e->count == profile_count::zero ()))
+      if (!(bb->count == profile_count::zero ()))
 	  {
-	    e->count = profile_count::zero ();
-	    if (!(e->src->count == profile_count::zero ()))
-	      {
-	        nsuccs[e->src->index]--;
-	        if (!nsuccs[e->src->index])
-		  worklist.safe_push (e->src);
-	      }
+	    if (dump_file && (dump_flags & TDF_DETAILS))
+	      fprintf (dump_file,
+		       "Basic block %i is marked unlikely by backward prop\n",
+		       bb->index);
+	    bb->count = profile_count::guessed_zero ();
+	    bb->frequency = 0;
+	    FOR_EACH_EDGE (e, ei, bb->preds)
+	      if (!(e->count == profile_count::zero ()))
+		{
+		  e->count = profile_count::guessed_zero ();
+		  if (!(e->src->count == profile_count::zero ()))
+		    {
+		      nsuccs[e->src->index]--;
+		      if (!nsuccs[e->src->index])
+			worklist.safe_push (e->src);
+		    }
+		}
 	  }
     }
 }
diff --git a/gcc/testsuite/gcc.dg/torture/pr81318.c b/gcc/testsuite/gcc.dg/torture/pr81318.c
new file mode 100644
index 00000000000..d6f005235bb
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr81318.c
@@ -0,0 +1,13 @@
+/* PR middle-end/81318 */
+
+__attribute__((__cold__)) void a();
+int d(void);
+int e(void);
+
+void b() { a(); }
+
+void c() {
+  b();
+  if (d())
+    e();
+}
-- 
2.13.3