Fix a crash in the legalization of large vectors.

When truncating a result of a vector that is split we need
to use the result of the split vector, and not re-split the dead node.

llvm-svn: 160357

1 files changed, 3 insertions, 6 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
index 75b31f79ade..af90e1d26d5 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
@@ -592,14 +592,11 @@ SDValue DAGTypeLegalizer::PromoteIntRes_TRUNCATE(SDNode *N) {
     assert(isPowerOf2_32(NumElts) &&
            "Promoted vector type must be a power of two");
 
-    EVT HalfVT = EVT::getVectorVT(*DAG.getContext(), EltVT, NumElts/2);
+    SDValue EOp1, EOp2;
+    GetSplitVector(InOp, EOp1, EOp2);
+
     EVT HalfNVT = EVT::getVectorVT(*DAG.getContext(), NVT.getScalarType(),
                                    NumElts/2);
-
-    SDValue EOp1 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, HalfVT, InOp,
-                               DAG.getIntPtrConstant(0));
-    SDValue EOp2 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, HalfVT, InOp,
-                               DAG.getIntPtrConstant(NumElts/2));
     EOp1 = DAG.getNode(ISD::TRUNCATE, dl, HalfNVT, EOp1);
     EOp2 = DAG.getNode(ISD::TRUNCATE, dl, HalfNVT, EOp2);