[MVT] Add v256i1 to MachineValueType

This type can show up when lowering some HVX vector code on Hexagon.

llvm-svn: 372403

1 files changed, 14 insertions, 7 deletions

diff --git a/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp b/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp
index ac70b4db86e..66b6e11bb07 100644
--- a/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp
@@ -1864,26 +1864,33 @@ bool HexagonTargetLowering::isShuffleMaskLegal(ArrayRef<int> Mask,
 
 TargetLoweringBase::LegalizeTypeAction
 HexagonTargetLowering::getPreferredVectorAction(MVT VT) const {
-  if (VT.getVectorNumElements() == 1 || VT.isScalableVector())
-    return TargetLoweringBase::TypeScalarizeVector;
-
-  // Always widen vectors of i1.
+  unsigned VecLen = VT.getVectorNumElements();
   MVT ElemTy = VT.getVectorElementType();
-  if (ElemTy == MVT::i1)
-    return TargetLoweringBase::TypeWidenVector;
+
+  if (VecLen == 1 || VT.isScalableVector())
+    return TargetLoweringBase::TypeScalarizeVector;
 
   if (Subtarget.useHVXOps()) {
+    unsigned HwLen = Subtarget.getVectorLength();
     // If the size of VT is at least half of the vector length,
     // widen the vector. Note: the threshold was not selected in
     // any scientific way.
     ArrayRef<MVT> Tys = Subtarget.getHVXElementTypes();
     if (llvm::find(Tys, ElemTy) != Tys.end()) {
-      unsigned HwWidth = 8*Subtarget.getVectorLength();
+      unsigned HwWidth = 8*HwLen;
       unsigned VecWidth = VT.getSizeInBits();
       if (VecWidth >= HwWidth/2 && VecWidth < HwWidth)
         return TargetLoweringBase::TypeWidenVector;
     }
+    // Split vectors of i1 that correspond to (byte) vector pairs.
+    if (ElemTy == MVT::i1 && VecLen == 2*HwLen)
+      return TargetLoweringBase::TypeSplitVector;
   }
+
+  // Always widen (remaining) vectors of i1.
+  if (ElemTy == MVT::i1)
+    return TargetLoweringBase::TypeWidenVector;
+
   return TargetLoweringBase::TypeSplitVector;
 }