diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
--- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -10,6 +10,8 @@
 // Details of the algorithm:
 //  https://github.com/google/sanitizers/wiki/AddressSanitizerAlgorithm
 //
+// FIXME: This sanitizer does not yet handle scalable vectors
+//
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Transforms/Instrumentation/AddressSanitizer.h"
@@ -1504,8 +1506,8 @@
                                         unsigned Granularity, uint32_t TypeSize,
                                         bool IsWrite, Value *SizeArgument,
                                         bool UseCalls, uint32_t Exp) {
-  auto *VTy =
-      cast<VectorType>(cast<PointerType>(Addr->getType())->getElementType());
+  auto *VTy = cast<FixedVectorType>(
+      cast<PointerType>(Addr->getType())->getElementType());
   uint64_t ElemTypeSize = DL.getTypeStoreSizeInBits(VTy->getScalarType());
   unsigned Num = VTy->getNumElements();
   auto Zero = ConstantInt::get(IntptrTy, 0);
diff --git a/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp b/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
--- a/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
@@ -137,6 +137,9 @@
 ///
 ///  KernelMemorySanitizer only supports X86_64 at the moment.
 ///
+//
+// FIXME: This sanitizer does not yet handle scalable vectors
+//
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Transforms/Instrumentation/MemorySanitizer.h"
@@ -1355,7 +1358,7 @@
     if (VectorType *VT = dyn_cast<VectorType>(OrigTy)) {
       uint32_t EltSize = DL.getTypeSizeInBits(VT->getElementType());
       return FixedVectorType::get(IntegerType::get(*MS.C, EltSize),
-                                  VT->getNumElements());
+                                  cast<FixedVectorType>(VT)->getNumElements());
     }
     if (ArrayType *AT = dyn_cast<ArrayType>(OrigTy)) {
       return ArrayType::get(getShadowTy(AT->getElementType()),
@@ -2077,7 +2080,7 @@
   size_t VectorOrPrimitiveTypeSizeInBits(Type *Ty) {
     assert(!(Ty->isVectorTy() && Ty->getScalarType()->isPointerTy()) &&
            "Vector of pointers is not a valid shadow type");
-    return Ty->isVectorTy() ? cast<VectorType>(Ty)->getNumElements() *
+    return Ty->isVectorTy() ? cast<FixedVectorType>(Ty)->getNumElements() *
                                   Ty->getScalarSizeInBits()
                             : Ty->getPrimitiveSizeInBits();
   }
@@ -2095,8 +2098,8 @@
     if (dstTy->isIntegerTy() && srcTy->isIntegerTy())
       return IRB.CreateIntCast(V, dstTy, Signed);
     if (dstTy->isVectorTy() && srcTy->isVectorTy() &&
-        cast<VectorType>(dstTy)->getNumElements() ==
-            cast<VectorType>(srcTy)->getNumElements())
+        cast<FixedVectorType>(dstTy)->getNumElements() ==
+            cast<FixedVectorType>(srcTy)->getNumElements())
       return IRB.CreateIntCast(V, dstTy, Signed);
     Value *V1 = IRB.CreateBitCast(V, Type::getIntNTy(*MS.C, srcSizeInBits));
     Value *V2 =
@@ -2141,7 +2144,7 @@
     Constant *ShadowMul;
     Type *Ty = ConstArg->getType();
     if (auto *VTy = dyn_cast<VectorType>(Ty)) {
-      unsigned NumElements = VTy->getNumElements();
+      unsigned NumElements = cast<FixedVectorType>(VTy)->getNumElements();
       Type *EltTy = VTy->getElementType();
       SmallVector<Constant *, 16> Elements;
       for (unsigned Idx = 0; Idx < NumElements; ++Idx) {
@@ -2969,8 +2972,8 @@
 
         Value *Acc = IRB.CreateExtractElement(
             MaskedPassThruShadow, ConstantInt::get(IRB.getInt32Ty(), 0));
-        for (int i = 1,
-                 N = cast<VectorType>(PassThru->getType())->getNumElements();
+        for (int i = 1, N = cast<FixedVectorType>(PassThru->getType())
+                                ->getNumElements();
              i < N; ++i) {
           Value *More = IRB.CreateExtractElement(
               MaskedPassThruShadow, ConstantInt::get(IRB.getInt32Ty(), i));
@@ -3030,7 +3033,7 @@
     IRBuilder<> IRB(&I);
     Type *ShadowTy = getShadowTy(&I);
     unsigned Width =
-        cast<VectorType>(I.getArgOperand(0)->getType())->getNumElements();
+        cast<FixedVectorType>(I.getArgOperand(0)->getType())->getNumElements();
     assert(isa<ConstantInt>(I.getArgOperand(2)) &&
            "pclmul 3rd operand must be a constant");
     unsigned Imm = cast<ConstantInt>(I.getArgOperand(2))->getZExtValue();