Fix reference to cached end iterator invalidated by an erase operation.

Uncovered by _GLIBCXX_DEBUG.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37795 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 3 insertions, 1 deletions

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 224006106b..6251d381be 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -1700,7 +1700,9 @@ unsigned SelectionDAGLowering::Clusterify(CaseVector& Cases,
 
   // Merge case into clusters
   if (Cases.size()>=2)
-    for (CaseItr I=Cases.begin(), J=++(Cases.begin()), E=Cases.end(); J!=E; ) {
+    // Cray [dag]: Must recompute end() each iteration because it may
+    // be invalidated by erase if we hold on to it
+    for (CaseItr I=Cases.begin(), J=++(Cases.begin()); J!=Cases.end(); ) {
       int64_t nextValue = cast<ConstantInt>(J->Low)->getSExtValue();
       int64_t currentValue = cast<ConstantInt>(I->High)->getSExtValue();
       MachineBasicBlock* nextBB = J->BB;