Index: include/llvm/IR/Intrinsics.h
===================================================================
--- include/llvm/IR/Intrinsics.h
+++ include/llvm/IR/Intrinsics.h
@@ -100,7 +100,7 @@
       Integer, Vector, Pointer, Struct,
       Argument, ExtendArgument, TruncArgument, HalfVecArgument,
       SameVecWidthArgument, PtrToArgument, PtrToElt, VecOfAnyPtrsToElt,
-      VecElementArgument
+      VecElementArgument, ScalableVecArgument
     } Kind;
 
     union {
Index: lib/IR/Function.cpp
===================================================================
--- lib/IR/Function.cpp
+++ lib/IR/Function.cpp
@@ -611,9 +611,11 @@
       Result += "vararg";
     // Ensure nested function types are distinguishable.
     Result += "f";
-  } else if (isa<VectorType>(Ty)) {
-    Result += "v" + utostr(Ty->getVectorNumElements()) +
-      getMangledTypeStr(Ty->getVectorElementType());
+  } else if (VectorType* VTy = dyn_cast<VectorType>(Ty)) {
+    if (VTy->isScalable())
+      Result += "nx";
+    Result += "v" + utostr(VTy->getVectorNumElements()) +
+      getMangledTypeStr(VTy->getVectorElementType());
   } else if (Ty) {
     switch (Ty->getTypeID()) {
     default: llvm_unreachable("Unhandled type");
@@ -700,7 +702,8 @@
   IIT_STRUCT7 = 39,
   IIT_STRUCT8 = 40,
   IIT_F128 = 41,
-  IIT_VEC_ELEMENT = 42
+  IIT_VEC_ELEMENT = 42,
+  IIT_SCALABLE_VEC = 43
 };
 
 static void DecodeIITType(unsigned &NextElt, ArrayRef<unsigned char> Infos,
@@ -871,6 +874,12 @@
                                              ArgInfo));
     return;
   }
+  case IIT_SCALABLE_VEC: {
+    OutputTable.push_back(IITDescriptor::get(IITDescriptor::ScalableVecArgument,
+                                             0));
+    DecodeIITType(NextElt, Infos, OutputTable);
+    return;
+  }
   }
   llvm_unreachable("unhandled");
 }
@@ -992,6 +1001,11 @@
   case IITDescriptor::VecOfAnyPtrsToElt:
     // Return the overloaded type (which determines the pointers address space)
     return Tys[D.getOverloadArgNumber()];
+  case IITDescriptor::ScalableVecArgument: {
+    Type *Ty = DecodeFixedType(Infos, Tys, Context);
+    return VectorType::get(Ty->getVectorElementType(),
+                           { Ty->getVectorNumElements(), true });
+  }
   }
   llvm_unreachable("unhandled");
 }
@@ -1255,6 +1269,13 @@
       auto *ReferenceType = dyn_cast<VectorType>(ArgTys[D.getArgumentNumber()]);
       return !ReferenceType || Ty != ReferenceType->getElementType();
     }
+    case IITDescriptor::ScalableVecArgument: {
+      VectorType *VTy = dyn_cast<VectorType>(Ty);
+      if (!VTy || !VTy->isScalable())
+        return true;
+      return matchIntrinsicType(VTy, Infos, ArgTys, DeferredChecks,
+                                IsDeferredCheck);
+    }
   }
   llvm_unreachable("unhandled");
 }
Index: utils/TableGen/IntrinsicEmitter.cpp
===================================================================
--- utils/TableGen/IntrinsicEmitter.cpp
+++ utils/TableGen/IntrinsicEmitter.cpp
@@ -220,7 +220,8 @@
   IIT_STRUCT7 = 39,
   IIT_STRUCT8 = 40,
   IIT_F128 = 41,
-  IIT_VEC_ELEMENT = 42
+  IIT_VEC_ELEMENT = 42,
+  IIT_SCALABLE_VEC = 43
 };
 
 static void EncodeFixedValueType(MVT::SimpleValueType VT,
@@ -339,6 +340,8 @@
 
   if (MVT(VT).isVector()) {
     MVT VVT = VT;
+    if (VVT.isScalableVector())
+      Sig.push_back(IIT_SCALABLE_VEC);
     switch (VVT.getVectorNumElements()) {
     default: PrintFatalError("unhandled vector type width in intrinsic!");
     case 1: Sig.push_back(IIT_V1); break;