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
@@ -591,8 +591,7 @@
   // Do not perform canonicalization if minmax pattern is found (to avoid
   // infinite loop).
   Type *Dummy;
-  if (!Ty->isIntegerTy() && Ty->isSized() &&
-      !(Ty->isVectorTy() && cast<VectorType>(Ty)->isScalable()) &&
+  if (!Ty->isIntegerTy() && Ty->isSized() && !isa<ScalableVectorType>(Ty) &&
       DL.isLegalInteger(DL.getTypeStoreSizeInBits(Ty)) &&
       DL.typeSizeEqualsStoreSize(Ty) && !DL.isNonIntegralPointerType(Ty) &&
       !isMinMaxWithLoads(
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
@@ -1740,16 +1740,15 @@
   SmallVector<Value*, 8> Ops(GEP.op_begin(), GEP.op_end());
   Type *GEPType = GEP.getType();
   Type *GEPEltType = GEP.getSourceElementType();
-  bool IsGEPSrcEleScalable =
-      GEPEltType->isVectorTy() && cast<VectorType>(GEPEltType)->isScalable();
+  bool IsGEPSrcEleScalable = isa<ScalableVectorType>(GEPEltType);
   if (Value *V = SimplifyGEPInst(GEPEltType, Ops, SQ.getWithInstruction(&GEP)))
     return replaceInstUsesWith(GEP, V);
 
   // For vector geps, use the generic demanded vector support.
   // Skip if GEP return type is scalable. The number of elements is unknown at
   // compile-time.
-  if (GEPType->isVectorTy() && !cast<VectorType>(GEPType)->isScalable()) {
-    auto VWidth = cast<VectorType>(GEPType)->getNumElements();
+  if (auto *GEPFVTy = dyn_cast<FixedVectorType>(GEPType)) {
+    auto VWidth = GEPFVTy->getNumElements();
     APInt UndefElts(VWidth, 0);
     APInt AllOnesEltMask(APInt::getAllOnesValue(VWidth));
     if (Value *V = SimplifyDemandedVectorElts(&GEP, AllOnesEltMask,
diff --git a/llvm/lib/Transforms/Instrumentation/PoisonChecking.cpp b/llvm/lib/Transforms/Instrumentation/PoisonChecking.cpp
--- a/llvm/lib/Transforms/Instrumentation/PoisonChecking.cpp
+++ b/llvm/lib/Transforms/Instrumentation/PoisonChecking.cpp
@@ -198,8 +198,8 @@
     break;
   case Instruction::ExtractElement: {
     Value *Vec = I.getOperand(0);
-    auto *VecVTy = cast<VectorType>(Vec->getType());
-    if (VecVTy->isScalable())
+    auto *VecVTy = dyn_cast<FixedVectorType>(Vec->getType());
+    if (!VecVTy)
       break;
     Value *Idx = I.getOperand(1);
     unsigned NumElts = VecVTy->getNumElements();
@@ -211,8 +211,8 @@
   }
   case Instruction::InsertElement: {
     Value *Vec = I.getOperand(0);
-    auto *VecVTy = cast<VectorType>(Vec->getType());
-    if (VecVTy->isScalable())
+    auto *VecVTy = dyn_cast<FixedVectorType>(Vec->getType());
+    if (!VecVTy)
       break;
     Value *Idx = I.getOperand(2);
     unsigned NumElts = VecVTy->getNumElements();
diff --git a/llvm/lib/Transforms/Scalar/SROA.cpp b/llvm/lib/Transforms/Scalar/SROA.cpp
--- a/llvm/lib/Transforms/Scalar/SROA.cpp
+++ b/llvm/lib/Transforms/Scalar/SROA.cpp
@@ -4482,8 +4482,7 @@
 
   // Skip alloca forms that this analysis can't handle.
   auto *AT = AI.getAllocatedType();
-  if (AI.isArrayAllocation() || !AT->isSized() ||
-      (isa<VectorType>(AT) && cast<VectorType>(AT)->isScalable()) ||
+  if (AI.isArrayAllocation() || !AT->isSized() || isa<ScalableVectorType>(AT) ||
       DL.getTypeAllocSize(AT).getFixedSize() == 0)
     return false;
 
@@ -4605,8 +4604,7 @@
   for (BasicBlock::iterator I = EntryBB.begin(), E = std::prev(EntryBB.end());
        I != E; ++I) {
     if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) {
-      if (isa<VectorType>(AI->getAllocatedType()) &&
-          cast<VectorType>(AI->getAllocatedType())->isScalable()) {
+      if (isa<ScalableVectorType>(AI->getAllocatedType())) {
         if (isAllocaPromotable(AI))
           PromotableAllocas.push_back(AI);
       } else {
diff --git a/llvm/lib/Transforms/Utils/VNCoercion.cpp b/llvm/lib/Transforms/Utils/VNCoercion.cpp
--- a/llvm/lib/Transforms/Utils/VNCoercion.cpp
+++ b/llvm/lib/Transforms/Utils/VNCoercion.cpp
@@ -11,8 +11,7 @@
 namespace VNCoercion {
 
 static bool isFirstClassAggregateOrScalableType(Type *Ty) {
-  return Ty->isStructTy() || Ty->isArrayTy() ||
-         (Ty->isVectorTy() && cast<VectorType>(Ty)->isScalable());
+  return Ty->isStructTy() || Ty->isArrayTy() || isa<ScalableVectorType>(Ty);
 }
 
 /// Return true if coerceAvailableValueToLoadType will succeed.