diff --git a/llvm/lib/CodeGen/PostRASchedulerList.cpp b/llvm/lib/CodeGen/PostRASchedulerList.cpp
--- a/llvm/lib/CodeGen/PostRASchedulerList.cpp
+++ b/llvm/lib/CodeGen/PostRASchedulerList.cpp
@@ -534,8 +534,13 @@
   for (unsigned i = 0, e = SUnits.size(); i != e; ++i) {
     // It is available if it has no predecessors.
     if (!SUnits[i].NumPredsLeft && !SUnits[i].isAvailable) {
-      AvailableQueue.push(&SUnits[i]);
-      SUnits[i].isAvailable = true;
+      if (SUnits[i].getDepth() > 0) {
+        assert(SUnits[i].WeakPredsLeft > 0 && "Expected a weak predecessor");
+        PendingQueue.push_back(&SUnits[i]);
+      } else {
+        AvailableQueue.push(&SUnits[i]);
+        SUnits[i].isAvailable = true;
+      }
     }
   }