Add a bunch of calls to RemoveDeadNode in LegalizeDAG, so legalization doesn't get confused by CSE later on. Fixes PR11318.
Re-commit of r144034, with an extra fix so that RemoveDeadNode doesn't blow up.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144055 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 010a740..b3f94a4 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -564,6 +564,12 @@
void SelectionDAG::RemoveDeadNode(SDNode *N, DAGUpdateListener *UpdateListener){
SmallVector<SDNode*, 16> DeadNodes(1, N);
+
+ // Create a dummy node that adds a reference to the root node, preventing
+ // it from being deleted. (This matters if the root is an operand of the
+ // dead node.)
+ HandleSDNode Dummy(getRoot());
+
RemoveDeadNodes(DeadNodes, UpdateListener);
}