re PR tree-optimization/81462 (ICE in estimate_bb_frequencies at gcc/predict.c:3546)

	PR middle-end/81462
	* predict.c (set_even_probabilities): Cleanup; do not affect
	probabilities that are already known.
	(combine_predictions_for_bb): Call even when count is set.

	* g++.dg/torture/pr81462.C: New testcase.

From-SVN: r250310

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 1d11ab5b95e89b9e952b9c8cdbc9f857a483ca0c..892c0258534c60ccb2c5dedc2d791d493a19b535 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2017-07-18  Jan Hubicka  <hubicka@ucw.cz>
+
+       PR middle-end/81462
+       * predict.c (set_even_probabilities): Cleanup; do not affect
+       probabilities that are already known.
+       (combine_predictions_for_bb): Call even when count is set.
+
 2017-07-18  Nathan Sidwell  <nathan@acm.org>
 
        * tree-parloops.c (try_transform_to_exit_first_loop_alt): Use

diff --git a/gcc/predict.c b/gcc/predict.c
index 310d9b0acedd88a522e4a01ac7bfbcef74d031e9..1e2e11d71f00e8b35cfbb7c3fb4b67d4d590e768 100644 (file)
--- a/gcc/predict.c
+++ b/gcc/predict.c
@@ -817,16 +817,25 @@ static void
 set_even_probabilities (basic_block bb,
                        hash_set<edge> *unlikely_edges = NULL)
 {
-  unsigned nedges = 0;
+  unsigned nedges = 0, unlikely_count = 0;
   edge e = NULL;
   edge_iterator ei;
+  profile_probability all = profile_probability::always ();
 
   FOR_EACH_EDGE (e, ei, bb->succs)
-    if (!unlikely_executed_edge_p (e))
-      nedges ++;
+    if (e->probability.initialized_p ())
+      all -= e->probability;
+    else if (!unlikely_executed_edge_p (e))
+      {
+        nedges ++;
+        if (unlikely_edges != NULL && unlikely_edges->contains (e))
+         {
+           all -= profile_probability::very_unlikely ();
+           unlikely_count++;
+         }
+      }
 
   /* Make the distribution even if all edges are unlikely.  */
-  unsigned unlikely_count = unlikely_edges ? unlikely_edges->elements () : 0;
   if (unlikely_count == nedges)
     {
       unlikely_edges = NULL;
@@ -836,13 +845,14 @@ set_even_probabilities (basic_block bb,
   unsigned c = nedges - unlikely_count;
 
   FOR_EACH_EDGE (e, ei, bb->succs)
-    if (!unlikely_executed_edge_p (e))
+    if (e->probability.initialized_p ())
+      ;
+    else if (!unlikely_executed_edge_p (e))
       {
        if (unlikely_edges != NULL && unlikely_edges->contains (e))
          e->probability = profile_probability::very_unlikely ();
        else
-         e->probability = profile_probability::guessed_always ()
-                               .apply_scale (1, c);
+         e->probability = all.apply_scale (1, c).guessed ();
       }
     else
       e->probability = profile_probability::never ();
@@ -1151,7 +1161,7 @@ combine_predictions_for_bb (basic_block bb, bool dry_run)
          if (pred->ep_probability <= PROB_VERY_UNLIKELY)
            unlikely_edges.add (pred->ep_edge);
 
-      if (!bb->count.initialized_p () && !dry_run)
+      if (!dry_run)
        set_even_probabilities (bb, &unlikely_edges);
       clear_bb_predictions (bb);
       if (dump_file)

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 91aa26c0cbce94352946c0f583f1a6557dbb0a4b..01f24abca7cd3454d4bc5091fc5aed1c019b7e09 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2017-07-18  Jan Hubicka  <hubicka@ucw.cz>
+
+       PR middle-end/81462
+       * g++.dg/torture/pr81462.C: New testcase.
+
 2017-07-18  Bin Cheng  <bin.cheng@arm.com>
 
        PR target/81408

diff --git a/gcc/testsuite/g++.dg/torture/pr81462.C b/gcc/testsuite/g++.dg/torture/pr81462.C
new file mode 100644 (file)
index 0000000..044c8b7
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/pr81462.C
@@ -0,0 +1,17 @@
+// { dg-do compile }
+// { dg-options "-O1 -fno-ipa-pure-const" }
+struct B {
+        B* self;
+        B() : self( this ) { self->f(); }
+        virtual void f() = 0;
+    };
+
+    struct D : B
+    {
+        void f() {}
+    };
+
+    int main()
+    {
+        D d;
+    }