From: Haojian Wu <hokein@google.com>
Date: Tue, 20 Jun 2017 09:29:43 +0000 (+0000)
Subject: [SelectionDAG] Fix an use-after-free issue introduced in r305775.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=921867e7f1d8da7a6afa4fa591ff2600c6979c44;p=llvm

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

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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@305785 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
index c90747943f5..70b1fa77a09 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
@@ -1888,10 +1888,10 @@ CalcNodeSethiUllmanNumber(const SUnit *SU, std::vector<unsigned> &SUNumbers) {
         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;
       }
     }