diff mbox series

Fix backward propagation of unlikely BBs

Message ID 20180113193256.GA21808@kam.mff.cuni.cz
State New
Headers show
Series Fix backward propagation of unlikely BBs | expand

Commit Message

Jan Hubicka Jan. 13, 2018, 7:32 p.m. UTC 
hi,
this patch fixes bug in backward propagation where some BBs can be marked
unlikely for incorrect reason.

Bootstrapped/regtested x86_64-linux,comitted.

Honza

	* predict.c (determine_unlikely_bbs): Handle correctly BBs
	which appears in the queue multiple times.
diff mbox series

Patch

Index: predict.c
===================================================================
--- predict.c	(revision 256604)
+++ predict.c	(working copy)
@@ -3565,6 +3566,8 @@  determine_unlikely_bbs ()
   while (worklist.length () > 0)
     {
       bb = worklist.pop ();
+      if (bb->count == profile_count::zero ())
+	continue;
       if (bb != ENTRY_BLOCK_PTR_FOR_FN (cfun))
 	{
 	  bool found = false;
@@ -3583,8 +3586,7 @@  determine_unlikely_bbs ()
 	  if (found)
 	    continue;
 	}
-      if (!(bb->count == profile_count::zero ())
-	  && (dump_file && (dump_flags & TDF_DETAILS)))
+      if (dump_file && (dump_flags & TDF_DETAILS))
 	fprintf (dump_file,
 		 "Basic block %i is marked unlikely by backward prop\n",
 		 bb->index);
@@ -3594,6 +3596,7 @@  determine_unlikely_bbs ()
 	  {
 	    if (!(e->src->count == profile_count::zero ()))
 	      {
+		gcc_checking_assert (nsuccs[e->src->index] > 0);
 	        nsuccs[e->src->index]--;
 	        if (!nsuccs[e->src->index])
 		  worklist.safe_push (e->src);