Fixed a bug in X86TargetLowering::LowerVectorIntExtend() (assertion failure).

Added a test.

llvm-svn: 175144

1 files changed, 17 insertions, 3 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 55de3d3c98a..dbc0e016f85 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -6662,9 +6662,10 @@ X86TargetLowering::LowerVectorIntExtend(SDValue Op, SelectionDAG &DAG) const {
       return SDValue();
   }
 
+  LLVMContext *Context = DAG.getContext();
   unsigned NBits = VT.getVectorElementType().getSizeInBits() << Shift;
-  EVT NeVT = EVT::getIntegerVT(*DAG.getContext(), NBits);
-  EVT NVT = EVT::getVectorVT(*DAG.getContext(), NeVT, NumElems >> Shift);
+  EVT NeVT = EVT::getIntegerVT(*Context, NBits);
+  EVT NVT = EVT::getVectorVT(*Context, NeVT, NumElems >> Shift);
 
   if (!isTypeLegal(NVT))
     return SDValue();
@@ -6683,8 +6684,21 @@ X86TargetLowering::LowerVectorIntExtend(SDValue Op, SelectionDAG &DAG) const {
     // If it's foldable, i.e. normal load with single use, we will let code
     // selection to fold it. Otherwise, we will short the conversion sequence.
     if (CIdx && CIdx->getZExtValue() == 0 &&
-        (!ISD::isNormalLoad(V.getNode()) || !V.hasOneUse()))
+        (!ISD::isNormalLoad(V.getNode()) || !V.hasOneUse())) {
+      if (V.getValueSizeInBits() > V1.getValueSizeInBits()) {
+        // The "ext_vec_elt" node is wider than the result node.
+        // In this case we should extract subvector from V.
+        // (bitcast (sclr2vec (ext_vec_elt x))) -> (bitcast (extract_subvector x)).
+        unsigned Ratio = V.getValueSizeInBits() / V1.getValueSizeInBits();
+        EVT FullVT = V.getValueType();
+        EVT SubVecVT = EVT::getVectorVT(*Context, 
+                                        FullVT.getVectorElementType(),
+                                        FullVT.getVectorNumElements()/Ratio);
+        V = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, SubVecVT, V, 
+                        DAG.getIntPtrConstant(0));
+      }
       V1 = DAG.getNode(ISD::BITCAST, DL, V1.getValueType(), V);
+    }
   }
 
   return DAG.getNode(ISD::BITCAST, DL, VT,