[vector-select] Address one of the issues in pr10902. EXTRACT_VECTOR_ELEMENT

SDNodes may return values which are wider than the incoming element types. In
this patch we fix the integer promotion of these nodes.

Fixes spill-q.ll when running -promote-elements.

llvm-svn: 140471

1 files changed, 7 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
index fc9a41ecaa9..80857e154af 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
@@ -2987,8 +2987,13 @@ SDValue DAGTypeLegalizer::PromoteIntOp_EXTRACT_VECTOR_ELT(SDNode *N) {
   SDValue Ext = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl,
     V0->getValueType(0).getScalarType(), V0, V1);
 
-  return DAG.getNode(ISD::TRUNCATE, dl, N->getValueType(0), Ext);
-
+  // EXTRACT_VECTOR_ELT can return types which are wider than the incoming
+  // element types (see PromoteIntRes_EXTRACT_VECTOR_ELT). If this is the case
+  // then we need to expand the outgoing value and not truncate it.
+  bool trunc = (N->getValueType(0).getSizeInBits() <
+                Ext.getValueType().getSizeInBits());
+  return DAG.getNode(trunc ? ISD::TRUNCATE : ISD::ANY_EXTEND,
+                     dl, N->getValueType(0), Ext);
 }
 
 SDValue DAGTypeLegalizer::PromoteIntOp_CONCAT_VECTORS(SDNode *N) {