[llvm] r305785 - [SelectionDAG] Fix an use-after-free issue introduced in r305775.

[Haojian Wu via llvm-commits]

Author: hokein
Date: Tue Jun 20 04:29:43 2017
New Revision: 305785

URL: http://llvm.org/viewvc/llvm-project?rev=305785&view=rev
Log:
[SelectionDAG] Fix an use-after-free issue introduced in r305775.

vector.back() will be invalidated when memory reallocation happens.

Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp?rev=305785&r1=305784&r2=305785&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp Tue Jun 20 04:29:43 2017
@@ -1888,10 +1888,10 @@ CalcNodeSethiUllmanNumber(const SUnit *S
         for (auto It : WorkList)
           assert(It.SU != PredSU && "Trying to push an element twice?");
 #endif
-        WorkList.push_back(PredSU);
-        AllPredsKnown = false;
         // Next time start processing this one starting from the next pred.
         Temp.PredsProcessed = P + 1;
+        WorkList.push_back(PredSU);
+        AllPredsKnown = false;
         break;
       }
     }