[SelectionDAG] Teach the vector scalarizer about TRUNCATE.

When a truncate node defines a legal vector type but uses an illegal
vector type, the legalization process was splitting the vector until
<1 x vector> type, but then it was failing to scalarize the node because
it did not know how to handle TRUNCATE.

<rdar://problem/14989896>

llvm-svn: 190830

2 files changed, 4 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.h b/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.h
index 97d28f0ff35..5085380cbb6 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.h
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.h
@@ -537,7 +537,7 @@ private:
   // Vector Operand Scalarization: <1 x ty> -> ty.
   bool ScalarizeVectorOperand(SDNode *N, unsigned OpNo);
   SDValue ScalarizeVecOp_BITCAST(SDNode *N);
-  SDValue ScalarizeVecOp_EXTEND(SDNode *N);
+  SDValue ScalarizeVecOp_UnaryOp(SDNode *N);
   SDValue ScalarizeVecOp_CONCAT_VECTORS(SDNode *N);
   SDValue ScalarizeVecOp_EXTRACT_VECTOR_ELT(SDNode *N);
   SDValue ScalarizeVecOp_STORE(StoreSDNode *N, unsigned OpNo);
diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
index 3032de626cf..472c5ca9890 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
@@ -371,7 +371,8 @@ bool DAGTypeLegalizer::ScalarizeVectorOperand(SDNode *N, unsigned OpNo) {
     case ISD::ANY_EXTEND:
     case ISD::ZERO_EXTEND:
     case ISD::SIGN_EXTEND:
-      Res = ScalarizeVecOp_EXTEND(N);
+    case ISD::TRUNCATE:
+      Res = ScalarizeVecOp_UnaryOp(N);
       break;
     case ISD::CONCAT_VECTORS:
       Res = ScalarizeVecOp_CONCAT_VECTORS(N);
@@ -410,7 +411,7 @@ SDValue DAGTypeLegalizer::ScalarizeVecOp_BITCAST(SDNode *N) {
 
 /// ScalarizeVecOp_EXTEND - If the value to extend is a vector that needs
 /// to be scalarized, it must be <1 x ty>.  Extend the element instead.
-SDValue DAGTypeLegalizer::ScalarizeVecOp_EXTEND(SDNode *N) {
+SDValue DAGTypeLegalizer::ScalarizeVecOp_UnaryOp(SDNode *N) {
   assert(N->getValueType(0).getVectorNumElements() == 1 &&
          "Unexected vector type!");
   SDValue Elt = GetScalarizedVector(N->getOperand(0));