diff --git a/llvm/include/llvm/Transforms/InstCombine/InstCombiner.h b/llvm/include/llvm/Transforms/InstCombine/InstCombiner.h
--- a/llvm/include/llvm/Transforms/InstCombine/InstCombiner.h
+++ b/llvm/include/llvm/Transforms/InstCombine/InstCombiner.h
@@ -335,7 +335,7 @@
       }
     }
     assert(SafeC && "Must have safe constant for binop");
-    unsigned NumElts = InVTy->getNumElements();
+    unsigned NumElts = cast<FixedVectorType>(InVTy)->getNumElements();
     SmallVector<Constant *, 16> Out(NumElts);
     for (unsigned i = 0; i != NumElts; ++i) {
       Constant *C = In->getAggregateElement(i);
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
--- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -1706,7 +1706,7 @@
 
   if (C->getType()->isVectorTy()) {
     // Check each element of a constant vector.
-    unsigned NumElts = cast<VectorType>(C->getType())->getNumElements();
+    unsigned NumElts = cast<FixedVectorType>(C->getType())->getNumElements();
     for (unsigned i = 0; i != NumElts; ++i) {
       Constant *Elt = C->getAggregateElement(i);
       if (!Elt)
@@ -2199,7 +2199,7 @@
 
 /// If all elements of two constant vectors are 0/-1 and inverses, return true.
 static bool areInverseVectorBitmasks(Constant *C1, Constant *C2) {
-  unsigned NumElts = cast<VectorType>(C1->getType())->getNumElements();
+  unsigned NumElts = cast<FixedVectorType>(C1->getType())->getNumElements();
   for (unsigned i = 0; i != NumElts; ++i) {
     Constant *EltC1 = C1->getAggregateElement(i);
     Constant *EltC2 = C2->getAggregateElement(i);
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -538,7 +538,7 @@
   if (!C)
     return nullptr;
 
-  auto *VecTy = cast<VectorType>(II.getType());
+  auto *VecTy = cast<FixedVectorType>(II.getType());
   unsigned NumElts = VecTy->getNumElements();
 
   // Only perform this transformation for <8 x i8> vector types.
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp
--- a/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp
@@ -875,7 +875,7 @@
   //   extractelement <8 x i32> (bitcast <4 x i64> %X to <8 x i32>), i32 0
   Value *VecOp;
   if (match(Src, m_OneUse(m_ExtractElt(m_Value(VecOp), m_ConstantInt(Cst))))) {
-    auto *VecOpTy = cast<VectorType>(VecOp->getType());
+    auto *VecOpTy = cast<FixedVectorType>(VecOp->getType());
     unsigned VecNumElts = VecOpTy->getNumElements();
 
     // A badly fit destination size would result in an invalid cast.
@@ -1538,7 +1538,7 @@
 
   Type *MinType = nullptr;
 
-  unsigned NumElts = CVVTy->getNumElements();
+  unsigned NumElts = cast<FixedVectorType>(CVVTy)->getNumElements();
   for (unsigned i = 0; i != NumElts; ++i) {
     auto *CFP = dyn_cast_or_null<ConstantFP>(CV->getAggregateElement(i));
     if (!CFP)
@@ -1942,7 +1942,8 @@
     if (auto *VecTy = dyn_cast<VectorType>(Ty)) {
       // Handle vectors of pointers.
       // FIXME: what should happen for scalable vectors?
-      IntPtrTy = FixedVectorType::get(IntPtrTy, VecTy->getNumElements());
+      IntPtrTy = FixedVectorType::get(
+          IntPtrTy, cast<FixedVectorType>(VecTy)->getNumElements());
     }
 
     Value *P = Builder.CreatePtrToInt(SrcOp, IntPtrTy);
@@ -1997,13 +1998,14 @@
       return nullptr;
 
     SrcTy =
-        FixedVectorType::get(DestTy->getElementType(), SrcTy->getNumElements());
+        FixedVectorType::get(DestTy->getElementType(),
+                             cast<FixedVectorType>(SrcTy)->getNumElements());
     InVal = IC.Builder.CreateBitCast(InVal, SrcTy);
   }
 
   bool IsBigEndian = IC.getDataLayout().isBigEndian();
-  unsigned SrcElts = SrcTy->getNumElements();
-  unsigned DestElts = DestTy->getNumElements();
+  unsigned SrcElts = cast<FixedVectorType>(SrcTy)->getNumElements();
+  unsigned DestElts = cast<FixedVectorType>(DestTy)->getNumElements();
 
   assert(SrcElts != DestElts && "Element counts should be different.");
 
@@ -2182,7 +2184,7 @@
 /// Into two insertelements that do "buildvector{%inc, %inc5}".
 static Value *optimizeIntegerToVectorInsertions(BitCastInst &CI,
                                                 InstCombinerImpl &IC) {
-  VectorType *DestVecTy = cast<VectorType>(CI.getType());
+  auto *DestVecTy = cast<FixedVectorType>(CI.getType());
   Value *IntInput = CI.getOperand(0);
 
   SmallVector<Value*, 8> Elements(DestVecTy->getNumElements());
@@ -2222,7 +2224,8 @@
   if (!VectorType::isValidElementType(DestType))
     return nullptr;
 
-  unsigned NumElts = ExtElt->getVectorOperandType()->getNumElements();
+  unsigned NumElts =
+      cast<FixedVectorType>(ExtElt->getVectorOperandType())->getNumElements();
   auto *NewVecType = FixedVectorType::get(DestType, NumElts);
   auto *NewBC = IC.Builder.CreateBitCast(ExtElt->getVectorOperand(),
                                          NewVecType, "bc");
@@ -2289,7 +2292,8 @@
   if (auto *CondVTy = dyn_cast<VectorType>(CondTy)) {
     if (!DestTy->isVectorTy())
       return nullptr;
-    if (cast<VectorType>(DestTy)->getNumElements() != CondVTy->getNumElements())
+    if (cast<FixedVectorType>(DestTy)->getNumElements() !=
+        cast<FixedVectorType>(CondVTy)->getNumElements())
       return nullptr;
   }
 
@@ -2625,11 +2629,12 @@
     // a bitcast to a vector with the same # elts.
     Value *ShufOp0 = Shuf->getOperand(0);
     Value *ShufOp1 = Shuf->getOperand(1);
-    unsigned NumShufElts = Shuf->getType()->getNumElements();
+    unsigned NumShufElts =
+        cast<FixedVectorType>(Shuf->getType())->getNumElements();
     unsigned NumSrcVecElts =
-        cast<VectorType>(ShufOp0->getType())->getNumElements();
+        cast<FixedVectorType>(ShufOp0->getType())->getNumElements();
     if (Shuf->hasOneUse() && DestTy->isVectorTy() &&
-        cast<VectorType>(DestTy)->getNumElements() == NumShufElts &&
+        cast<FixedVectorType>(DestTy)->getNumElements() == NumShufElts &&
         NumShufElts == NumSrcVecElts) {
       BitCastInst *Tmp;
       // If either of the operands is a cast from CI.getType(), then
@@ -2697,7 +2702,8 @@
     if (VectorType *VT = dyn_cast<VectorType>(CI.getType())) {
       // Handle vectors of pointers.
       // FIXME: what should happen for scalable vectors?
-      MidTy = FixedVectorType::get(MidTy, VT->getNumElements());
+      MidTy = FixedVectorType::get(MidTy,
+                                   cast<FixedVectorType>(VT)->getNumElements());
     }
 
     Value *NewBitCast = Builder.CreateBitCast(Src, MidTy);
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -898,7 +898,7 @@
     // For vectors, we apply the same reasoning on a per-lane basis.
     auto *Base = GEPLHS->getPointerOperand();
     if (GEPLHS->getType()->isVectorTy() && Base->getType()->isPointerTy()) {
-      int NumElts = cast<VectorType>(GEPLHS->getType())->getNumElements();
+      int NumElts = cast<FixedVectorType>(GEPLHS->getType())->getNumElements();
       Base = Builder.CreateVectorSplat(NumElts, Base);
     }
     return new ICmpInst(Cond, Base,
@@ -1886,7 +1886,8 @@
     if (ExactLogBase2 != -1 && DL.isLegalInteger(ExactLogBase2 + 1)) {
       Type *NTy = IntegerType::get(Cmp.getContext(), ExactLogBase2 + 1);
       if (auto *AndVTy = dyn_cast<VectorType>(And->getType()))
-        NTy = FixedVectorType::get(NTy, AndVTy->getNumElements());
+        NTy = FixedVectorType::get(
+            NTy, cast<FixedVectorType>(AndVTy)->getNumElements());
       Value *Trunc = Builder.CreateTrunc(X, NTy);
       auto NewPred = Cmp.getPredicate() == CmpInst::ICMP_EQ ? CmpInst::ICMP_SGE
                                                             : CmpInst::ICMP_SLT;
@@ -2192,7 +2193,8 @@
       DL.isLegalInteger(TypeBits - Amt)) {
     Type *TruncTy = IntegerType::get(Cmp.getContext(), TypeBits - Amt);
     if (auto *ShVTy = dyn_cast<VectorType>(ShType))
-      TruncTy = FixedVectorType::get(TruncTy, ShVTy->getNumElements());
+      TruncTy = FixedVectorType::get(
+          TruncTy, cast<FixedVectorType>(ShVTy)->getNumElements());
     Constant *NewC =
         ConstantInt::get(TruncTy, C.ashr(*ShiftAmt).trunc(TypeBits - Amt));
     return new ICmpInst(Pred, Builder.CreateTrunc(X, TruncTy), NewC);
@@ -2826,7 +2828,8 @@
 
           Type *NewType = Builder.getIntNTy(XType->getScalarSizeInBits());
           if (auto *XVTy = dyn_cast<VectorType>(XType))
-            NewType = FixedVectorType::get(NewType, XVTy->getNumElements());
+            NewType = FixedVectorType::get(
+                NewType, cast<FixedVectorType>(XVTy)->getNumElements());
           Value *NewBitcast = Builder.CreateBitCast(X, NewType);
           if (TrueIfSigned)
             return new ICmpInst(ICmpInst::ICMP_SLT, NewBitcast,
@@ -3391,7 +3394,7 @@
   Type *OpTy = M->getType();
   auto *VecC = dyn_cast<Constant>(M);
   if (OpTy->isVectorTy() && VecC && VecC->containsUndefElement()) {
-    auto *OpVTy = cast<VectorType>(OpTy);
+    auto *OpVTy = cast<FixedVectorType>(OpTy);
     Constant *SafeReplacementConstant = nullptr;
     for (unsigned i = 0, e = OpVTy->getNumElements(); i != e; ++i) {
       if (!isa<UndefValue>(VecC->getAggregateElement(i))) {
@@ -5241,7 +5244,7 @@
     if (!ConstantIsOk(CI))
       return llvm::None;
   } else if (auto *VTy = dyn_cast<VectorType>(Type)) {
-    unsigned NumElts = VTy->getNumElements();
+    unsigned NumElts = cast<FixedVectorType>(VTy)->getNumElements();
     for (unsigned i = 0; i != NumElts; ++i) {
       Constant *Elt = C->getAggregateElement(i);
       if (!Elt)
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
--- a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
@@ -1065,11 +1065,11 @@
     return nullptr;
   }
   if (auto *AT = dyn_cast<ArrayType>(VT)) {
-    if (AT->getNumElements() != UT->getNumElements())
+    if (AT->getNumElements() != cast<FixedVectorType>(UT)->getNumElements())
       return nullptr;
   } else {
     auto *ST = cast<StructType>(VT);
-    if (ST->getNumElements() != UT->getNumElements())
+    if (ST->getNumElements() != cast<FixedVectorType>(UT)->getNumElements())
       return nullptr;
     for (const auto *EltT : ST->elements()) {
       if (EltT != UT->getElementType())
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
--- a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
@@ -1516,7 +1516,7 @@
   // If it's a constant vector, flip any negative values positive.
   if (isa<ConstantVector>(Op1) || isa<ConstantDataVector>(Op1)) {
     Constant *C = cast<Constant>(Op1);
-    unsigned VWidth = cast<VectorType>(C->getType())->getNumElements();
+    unsigned VWidth = cast<FixedVectorType>(C->getType())->getNumElements();
 
     bool hasNegative = false;
     bool hasMissing = false;
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
--- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -305,8 +305,8 @@
     if (auto *CondVTy = dyn_cast<VectorType>(CondTy)) {
       if (!FIOpndTy->isVectorTy())
         return nullptr;
-      if (CondVTy->getNumElements() !=
-          cast<VectorType>(FIOpndTy)->getNumElements())
+      if (cast<FixedVectorType>(CondVTy)->getNumElements() !=
+          cast<FixedVectorType>(FIOpndTy)->getNumElements())
         return nullptr;
 
       // TODO: If the backend knew how to deal with casts better, we could
@@ -1971,7 +1971,8 @@
   if (!CondVal->getType()->isVectorTy() || !match(CondVal, m_Constant(CondC)))
     return nullptr;
 
-  unsigned NumElts = cast<VectorType>(CondVal->getType())->getNumElements();
+  unsigned NumElts =
+      cast<FixedVectorType>(CondVal->getType())->getNumElements();
   SmallVector<int, 16> Mask;
   Mask.reserve(NumElts);
   for (unsigned i = 0; i != NumElts; ++i) {
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
--- a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
@@ -392,7 +392,8 @@
     if (VectorType *DstVTy = dyn_cast<VectorType>(I->getType())) {
       if (VectorType *SrcVTy =
             dyn_cast<VectorType>(I->getOperand(0)->getType())) {
-        if (DstVTy->getNumElements() != SrcVTy->getNumElements())
+        if (cast<FixedVectorType>(DstVTy)->getNumElements() !=
+            cast<FixedVectorType>(SrcVTy)->getNumElements())
           // Don't touch a bitcast between vectors of different element counts.
           return nullptr;
       } else
@@ -1186,8 +1187,8 @@
     assert(Shuffle->getOperand(0)->getType() ==
            Shuffle->getOperand(1)->getType() &&
            "Expected shuffle operands to have same type");
-    unsigned OpWidth =
-        cast<VectorType>(Shuffle->getOperand(0)->getType())->getNumElements();
+    unsigned OpWidth = cast<FixedVectorType>(Shuffle->getOperand(0)->getType())
+                           ->getNumElements();
     // Handle trivial case of a splat. Only check the first element of LHS
     // operand.
     if (all_of(Shuffle->getShuffleMask(), [](int Elt) { return Elt == 0; }) &&
@@ -1288,7 +1289,8 @@
     // this constant vector to single insertelement instruction.
     // shufflevector V, C, <v1, v2, .., ci, .., vm> ->
     // insertelement V, C[ci], ci-n
-    if (OpWidth == Shuffle->getType()->getNumElements()) {
+    if (OpWidth ==
+        cast<FixedVectorType>(Shuffle->getType())->getNumElements()) {
       Value *Op = nullptr;
       Constant *Value = nullptr;
       unsigned Idx = -1u;
@@ -1375,7 +1377,7 @@
     // Vector->vector casts only.
     VectorType *VTy = dyn_cast<VectorType>(I->getOperand(0)->getType());
     if (!VTy) break;
-    unsigned InVWidth = VTy->getNumElements();
+    unsigned InVWidth = cast<FixedVectorType>(VTy)->getNumElements();
     APInt InputDemandedElts(InVWidth, 0);
     UndefElts2 = APInt(InVWidth, 0);
     unsigned Ratio;
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp b/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
--- a/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
@@ -185,15 +185,19 @@
   // extelt (bitcast VecX), IndexC --> bitcast X[IndexC]
   auto *SrcTy = cast<VectorType>(X->getType());
   Type *DestTy = Ext.getType();
-  unsigned NumSrcElts = SrcTy->getNumElements();
-  unsigned NumElts = Ext.getVectorOperandType()->getNumElements();
+  ElementCount NumSrcElts = SrcTy->getElementCount();
+  ElementCount NumElts =
+      cast<VectorType>(Ext.getVectorOperandType())->getElementCount();
   if (NumSrcElts == NumElts)
     if (Value *Elt = findScalarElement(X, ExtIndexC))
       return new BitCastInst(Elt, DestTy);
 
+  assert(NumSrcElts.isScalable() == NumElts.isScalable() &&
+         "Src and Dst must be the same sort of vector type");
+
   // If the source elements are wider than the destination, try to shift and
   // truncate a subset of scalar bits of an insert op.
-  if (NumSrcElts < NumElts) {
+  if (NumSrcElts.getKnownMinValue() < NumElts.getKnownMinValue()) {
     Value *Scalar;
     uint64_t InsIndexC;
     if (!match(X, m_InsertElt(m_Value(), m_Value(Scalar),
@@ -204,7 +208,7 @@
     // into. Example: if we inserted element 1 of a <2 x i64> and we are
     // extracting an i16 (narrowing ratio = 4), then this extract must be from 1
     // of elements 4-7 of the bitcasted vector.
-    unsigned NarrowingRatio = NumElts / NumSrcElts;
+    unsigned NarrowingRatio = NumElts.getKnownMinValue() / NumSrcElts.getKnownMinValue();
     if (ExtIndexC / NarrowingRatio != InsIndexC)
       return nullptr;
 
@@ -266,7 +270,7 @@
 
 /// Find elements of V demanded by UserInstr.
 static APInt findDemandedEltsBySingleUser(Value *V, Instruction *UserInstr) {
-  unsigned VWidth = cast<VectorType>(V->getType())->getNumElements();
+  unsigned VWidth = cast<FixedVectorType>(V->getType())->getNumElements();
 
   // Conservatively assume that all elements are needed.
   APInt UsedElts(APInt::getAllOnesValue(VWidth));
@@ -284,7 +288,7 @@
   case Instruction::ShuffleVector: {
     ShuffleVectorInst *Shuffle = cast<ShuffleVectorInst>(UserInstr);
     unsigned MaskNumElts =
-        cast<VectorType>(UserInstr->getType())->getNumElements();
+        cast<FixedVectorType>(UserInstr->getType())->getNumElements();
 
     UsedElts = APInt(VWidth, 0);
     for (unsigned i = 0; i < MaskNumElts; i++) {
@@ -310,7 +314,7 @@
 /// no user demands an element of V, then the corresponding bit
 /// remains unset in the returned value.
 static APInt findDemandedEltsByAllUsers(Value *V) {
-  unsigned VWidth = cast<VectorType>(V->getType())->getNumElements();
+  unsigned VWidth = cast<FixedVectorType>(V->getType())->getNumElements();
 
   APInt UnionUsedElts(VWidth, 0);
   for (const Use &U : V->uses()) {
@@ -467,7 +471,7 @@
                                          SmallVectorImpl<int> &Mask) {
   assert(LHS->getType() == RHS->getType() &&
          "Invalid CollectSingleShuffleElements");
-  unsigned NumElts = cast<VectorType>(V->getType())->getNumElements();
+  unsigned NumElts = cast<FixedVectorType>(V->getType())->getNumElements();
 
   if (isa<UndefValue>(V)) {
     Mask.assign(NumElts, -1);
@@ -509,7 +513,7 @@
         unsigned ExtractedIdx =
         cast<ConstantInt>(EI->getOperand(1))->getZExtValue();
         unsigned NumLHSElts =
-            cast<VectorType>(LHS->getType())->getNumElements();
+            cast<FixedVectorType>(LHS->getType())->getNumElements();
 
         // This must be extracting from either LHS or RHS.
         if (EI->getOperand(0) == LHS || EI->getOperand(0) == RHS) {
@@ -539,8 +543,8 @@
 static void replaceExtractElements(InsertElementInst *InsElt,
                                    ExtractElementInst *ExtElt,
                                    InstCombinerImpl &IC) {
-  VectorType *InsVecType = InsElt->getType();
-  VectorType *ExtVecType = ExtElt->getVectorOperandType();
+  auto *InsVecType = cast<FixedVectorType>(InsElt->getType());
+  auto *ExtVecType = cast<FixedVectorType>(ExtElt->getVectorOperandType());
   unsigned NumInsElts = InsVecType->getNumElements();
   unsigned NumExtElts = ExtVecType->getNumElements();
 
@@ -668,7 +672,7 @@
           }
 
           unsigned NumLHSElts =
-              cast<VectorType>(RHS->getType())->getNumElements();
+              cast<FixedVectorType>(RHS->getType())->getNumElements();
           Mask[InsertedIdx % NumElts] = NumLHSElts + ExtractedIdx;
           return std::make_pair(LR.first, RHS);
         }
@@ -677,7 +681,8 @@
           // We've gone as far as we can: anything on the other side of the
           // extractelement will already have been converted into a shuffle.
           unsigned NumLHSElts =
-              cast<VectorType>(EI->getOperand(0)->getType())->getNumElements();
+              cast<FixedVectorType>(EI->getOperand(0)->getType())
+                  ->getNumElements();
           for (unsigned i = 0; i != NumElts; ++i)
             Mask.push_back(i == InsertedIdx ? ExtractedIdx : NumLHSElts + i);
           return std::make_pair(EI->getOperand(0), PermittedRHS);
@@ -1147,7 +1152,8 @@
   // For example:
   // inselt (shuf (inselt undef, X, 0), undef, <0,undef,0,undef>), X, 1
   //   --> shuf (inselt undef, X, 0), undef, <0,0,0,undef>
-  unsigned NumMaskElts = Shuf->getType()->getNumElements();
+  unsigned NumMaskElts =
+      cast<FixedVectorType>(Shuf->getType())->getNumElements();
   SmallVector<int, 16> NewMask(NumMaskElts);
   for (unsigned i = 0; i != NumMaskElts; ++i)
     NewMask[i] = i == IdxC ? 0 : Shuf->getMaskValue(i);
@@ -1185,7 +1191,8 @@
   // that same index value.
   // For example:
   // inselt (shuf X, IdMask), (extelt X, IdxC), IdxC --> shuf X, IdMask'
-  unsigned NumMaskElts = Shuf->getType()->getNumElements();
+  unsigned NumMaskElts =
+      cast<FixedVectorType>(Shuf->getType())->getNumElements();
   SmallVector<int, 16> NewMask(NumMaskElts);
   ArrayRef<int> OldMask = Shuf->getShuffleMask();
   for (unsigned i = 0; i != NumMaskElts; ++i) {
@@ -1515,7 +1522,7 @@
       // longer vector ops, but that may result in more expensive codegen.
       Type *ITy = I->getType();
       if (ITy->isVectorTy() &&
-          Mask.size() > cast<VectorType>(ITy)->getNumElements())
+          Mask.size() > cast<FixedVectorType>(ITy)->getNumElements())
         return false;
       for (Value *Operand : I->operands()) {
         if (!canEvaluateShuffled(Operand, Mask, Depth - 1))
@@ -1673,7 +1680,8 @@
     case Instruction::GetElementPtr: {
       SmallVector<Value*, 8> NewOps;
       bool NeedsRebuild =
-          (Mask.size() != cast<VectorType>(I->getType())->getNumElements());
+          (Mask.size() !=
+           cast<FixedVectorType>(I->getType())->getNumElements());
       for (int i = 0, e = I->getNumOperands(); i != e; ++i) {
         Value *V;
         // Recursively call evaluateInDifferentElementOrder on vector arguments
@@ -1728,7 +1736,7 @@
 static bool isShuffleExtractingFromLHS(ShuffleVectorInst &SVI,
                                        ArrayRef<int> Mask) {
   unsigned LHSElems =
-      cast<VectorType>(SVI.getOperand(0)->getType())->getNumElements();
+      cast<FixedVectorType>(SVI.getOperand(0)->getType())->getNumElements();
   unsigned MaskElems = Mask.size();
   unsigned BegIdx = Mask.front();
   unsigned EndIdx = Mask.back();
@@ -1860,7 +1868,8 @@
   // For example:
   // shuf (inselt undef, X, 2), undef, <2,2,undef>
   //   --> shuf (inselt undef, X, 0), undef, <0,0,undef>
-  unsigned NumMaskElts = Shuf.getType()->getNumElements();
+  unsigned NumMaskElts =
+      cast<FixedVectorType>(Shuf.getType())->getNumElements();
   SmallVector<int, 16> NewMask(NumMaskElts, 0);
   for (unsigned i = 0; i != NumMaskElts; ++i)
     if (Mask[i] == UndefMaskElem)
@@ -1878,7 +1887,7 @@
 
   // Canonicalize to choose from operand 0 first unless operand 1 is undefined.
   // Commuting undef to operand 0 conflicts with another canonicalization.
-  unsigned NumElts = Shuf.getType()->getNumElements();
+  unsigned NumElts = cast<FixedVectorType>(Shuf.getType())->getNumElements();
   if (!isa<UndefValue>(Shuf.getOperand(1)) &&
       Shuf.getMaskValue(0) >= (int)NumElts) {
     // TODO: Can we assert that both operands of a shuffle-select are not undef
@@ -2013,8 +2022,8 @@
   // and the source element type must be larger than the shuffle element type.
   Type *SrcType = X->getType();
   if (!SrcType->isVectorTy() || !SrcType->isIntOrIntVectorTy() ||
-      cast<VectorType>(SrcType)->getNumElements() !=
-          cast<VectorType>(DestType)->getNumElements() ||
+      cast<FixedVectorType>(SrcType)->getNumElements() !=
+          cast<FixedVectorType>(DestType)->getNumElements() ||
       SrcType->getScalarSizeInBits() % DestType->getScalarSizeInBits() != 0)
     return nullptr;
 
@@ -2058,10 +2067,11 @@
 
   // We need a narrow condition value. It must be extended with undef elements
   // and have the same number of elements as this shuffle.
-  unsigned NarrowNumElts = Shuf.getType()->getNumElements();
+  unsigned NarrowNumElts =
+      cast<FixedVectorType>(Shuf.getType())->getNumElements();
   Value *NarrowCond;
   if (!match(Cond, m_OneUse(m_Shuffle(m_Value(NarrowCond), m_Undef()))) ||
-      cast<VectorType>(NarrowCond->getType())->getNumElements() !=
+      cast<FixedVectorType>(NarrowCond->getType())->getNumElements() !=
           NarrowNumElts ||
       !cast<ShuffleVectorInst>(Cond)->isIdentityWithPadding())
     return nullptr;
@@ -2101,7 +2111,7 @@
   // new shuffle mask. Otherwise, copy the original mask element. Example:
   //   shuf (shuf X, Y, <C0, C1, C2, undef, C4>), undef, <0, undef, 2, 3> -->
   //   shuf X, Y, <C0, undef, C2, undef>
-  unsigned NumElts = Shuf.getType()->getNumElements();
+  unsigned NumElts = cast<FixedVectorType>(Shuf.getType())->getNumElements();
   SmallVector<int, 16> NewMask(NumElts);
   assert(NumElts < Mask.size() &&
          "Identity with extract must have less elements than its inputs");
@@ -2126,7 +2136,7 @@
   // TODO: This restriction could be removed if the insert has only one use
   //       (because the transform would require a new length-changing shuffle).
   int NumElts = Mask.size();
-  if (NumElts != (int)(cast<VectorType>(V0->getType())->getNumElements()))
+  if (NumElts != (int)(cast<FixedVectorType>(V0->getType())->getNumElements()))
     return nullptr;
 
   // This is a specialization of a fold in SimplifyDemandedVectorElts. We may
@@ -2221,9 +2231,10 @@
   Value *X = Shuffle0->getOperand(0);
   Value *Y = Shuffle1->getOperand(0);
   if (X->getType() != Y->getType() ||
-      !isPowerOf2_32(Shuf.getType()->getNumElements()) ||
-      !isPowerOf2_32(Shuffle0->getType()->getNumElements()) ||
-      !isPowerOf2_32(cast<VectorType>(X->getType())->getNumElements()) ||
+      !isPowerOf2_32(cast<FixedVectorType>(Shuf.getType())->getNumElements()) ||
+      !isPowerOf2_32(
+          cast<FixedVectorType>(Shuffle0->getType())->getNumElements()) ||
+      !isPowerOf2_32(cast<FixedVectorType>(X->getType())->getNumElements()) ||
       isa<UndefValue>(X) || isa<UndefValue>(Y))
     return nullptr;
   assert(isa<UndefValue>(Shuffle0->getOperand(1)) &&
@@ -2234,8 +2245,8 @@
   // operands directly by adjusting the shuffle mask to account for the narrower
   // types:
   // shuf (widen X), (widen Y), Mask --> shuf X, Y, Mask'
-  int NarrowElts = cast<VectorType>(X->getType())->getNumElements();
-  int WideElts = Shuffle0->getType()->getNumElements();
+  int NarrowElts = cast<FixedVectorType>(X->getType())->getNumElements();
+  int WideElts = cast<FixedVectorType>(Shuffle0->getType())->getNumElements();
   assert(WideElts > NarrowElts && "Unexpected types for identity with padding");
 
   ArrayRef<int> Mask = Shuf.getShuffleMask();
@@ -2276,9 +2287,13 @@
                                           SVI.getType(), ShufQuery))
     return replaceInstUsesWith(SVI, V);
 
+  // Bail out for scalable vectors
+  if (isa<ScalableVectorType>(LHS->getType()))
+    return nullptr;
+
   // shuffle x, x, mask --> shuffle x, undef, mask'
-  unsigned VWidth = SVI.getType()->getNumElements();
-  unsigned LHSWidth = cast<VectorType>(LHS->getType())->getNumElements();
+  unsigned VWidth = cast<FixedVectorType>(SVI.getType())->getNumElements();
+  unsigned LHSWidth = cast<FixedVectorType>(LHS->getType())->getNumElements();
   ArrayRef<int> Mask = SVI.getShuffleMask();
   Type *Int32Ty = Type::getInt32Ty(SVI.getContext());
 
@@ -2292,7 +2307,7 @@
   if (match(LHS, m_BitCast(m_Value(X))) && match(RHS, m_Undef()) &&
       X->getType()->isVectorTy() && VWidth == LHSWidth) {
     // Try to create a scaled mask constant.
-    auto *XType = cast<VectorType>(X->getType());
+    auto *XType = cast<FixedVectorType>(X->getType());
     unsigned XNumElts = XType->getNumElements();
     SmallVector<int, 16> ScaledMask;
     if (XNumElts >= VWidth) {
@@ -2400,7 +2415,7 @@
   if (isShuffleExtractingFromLHS(SVI, Mask)) {
     Value *V = LHS;
     unsigned MaskElems = Mask.size();
-    VectorType *SrcTy = cast<VectorType>(V->getType());
+    auto *SrcTy = cast<FixedVectorType>(V->getType());
     unsigned VecBitWidth = SrcTy->getPrimitiveSizeInBits().getFixedSize();
     unsigned SrcElemBitWidth = DL.getTypeSizeInBits(SrcTy->getElementType());
     assert(SrcElemBitWidth && "vector elements must have a bitwidth");
@@ -2518,11 +2533,11 @@
   if (LHSShuffle) {
     LHSOp0 = LHSShuffle->getOperand(0);
     LHSOp1 = LHSShuffle->getOperand(1);
-    LHSOp0Width = cast<VectorType>(LHSOp0->getType())->getNumElements();
+    LHSOp0Width = cast<FixedVectorType>(LHSOp0->getType())->getNumElements();
   }
   if (RHSShuffle) {
     RHSOp0 = RHSShuffle->getOperand(0);
-    RHSOp0Width = cast<VectorType>(RHSOp0->getType())->getNumElements();
+    RHSOp0Width = cast<FixedVectorType>(RHSOp0->getType())->getNumElements();
   }
   Value* newLHS = LHS;
   Value* newRHS = RHS;
diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
--- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -956,7 +956,8 @@
       return nullptr;
 
     // If vectors, verify that they have the same number of elements.
-    if (SrcTy && SrcTy->getNumElements() != DestTy->getNumElements())
+    if (SrcTy && cast<FixedVectorType>(SrcTy)->getNumElements() !=
+                     cast<FixedVectorType>(DestTy)->getNumElements())
       return nullptr;
   }
 
@@ -2368,7 +2369,7 @@
     // gep (bitcast [c x ty]* X to <c x ty>*), Y, Z --> gep X, Y, Z
     auto areMatchingArrayAndVecTypes = [](Type *ArrTy, Type *VecTy,
                                           const DataLayout &DL) {
-      auto *VecVTy = cast<VectorType>(VecTy);
+      auto *VecVTy = cast<FixedVectorType>(VecTy);
       return ArrTy->getArrayElementType() == VecVTy->getElementType() &&
              ArrTy->getArrayNumElements() == VecVTy->getNumElements() &&
              DL.getTypeAllocSize(ArrTy) == DL.getTypeAllocSize(VecTy);