4 files changed, 22 insertions, 9 deletions

diff --git a/llvm/lib/IR/AsmWriter.cpp b/llvm/lib/IR/AsmWriter.cpp
index a5adfd9c8a6..eb5760daecb 100644
--- a/llvm/lib/IR/AsmWriter.cpp
+++ b/llvm/lib/IR/AsmWriter.cpp
@@ -620,7 +620,10 @@ void TypePrinting::print(Type *Ty, raw_ostream &OS) {
   }
   case Type::VectorTyID: {
     VectorType *PTy = cast<VectorType>(Ty);
-    OS << "<" << PTy->getNumElements() << " x ";
+    OS << "<";
+    if (PTy->isScalable())
+      OS << "vscale x ";
+    OS << PTy->getNumElements() << " x ";
     print(PTy->getElementType(), OS);
     OS << '>';
     return;
diff --git a/llvm/lib/IR/LLVMContextImpl.h b/llvm/lib/IR/LLVMContextImpl.h
index 4560617624e..78cf707e0e7 100644
--- a/llvm/lib/IR/LLVMContextImpl.h
+++ b/llvm/lib/IR/LLVMContextImpl.h
@@ -1334,7 +1334,7 @@ public:
   unsigned NamedStructTypesUniqueID = 0;
 
   DenseMap<std::pair<Type *, uint64_t>, ArrayType*> ArrayTypes;
-  DenseMap<std::pair<Type *, unsigned>, VectorType*> VectorTypes;
+  DenseMap<std::pair<Type *, ElementCount>, VectorType*> VectorTypes;
   DenseMap<Type*, PointerType*> PointerTypes;  // Pointers in AddrSpace = 0
   DenseMap<std::pair<Type*, unsigned>, PointerType*> ASPointerTypes;
 
diff --git a/llvm/lib/IR/Type.cpp b/llvm/lib/IR/Type.cpp
index 4016bb10ba3..8ece7f223dd 100644
--- a/llvm/lib/IR/Type.cpp
+++ b/llvm/lib/IR/Type.cpp
@@ -504,6 +504,8 @@ StringRef StructType::getName() const {
 }
 
 bool StructType::isValidElementType(Type *ElemTy) {
+  if (auto *VTy = dyn_cast<VectorType>(ElemTy))
+    return !VTy->isScalable();
   return !ElemTy->isVoidTy() && !ElemTy->isLabelTy() &&
          !ElemTy->isMetadataTy() && !ElemTy->isFunctionTy() &&
          !ElemTy->isTokenTy();
@@ -590,6 +592,8 @@ ArrayType *ArrayType::get(Type *ElementType, uint64_t NumElements) {
 }
 
 bool ArrayType::isValidElementType(Type *ElemTy) {
+  if (auto *VTy = dyn_cast<VectorType>(ElemTy))
+    return !VTy->isScalable();
   return !ElemTy->isVoidTy() && !ElemTy->isLabelTy() &&
          !ElemTy->isMetadataTy() && !ElemTy->isFunctionTy() &&
          !ElemTy->isTokenTy();
@@ -599,21 +603,20 @@ bool ArrayType::isValidElementType(Type *ElemTy) {
 //                          VectorType Implementation
 //===----------------------------------------------------------------------===//
 
-VectorType::VectorType(Type *ElType, unsigned NumEl)
-  : SequentialType(VectorTyID, ElType, NumEl) {}
+VectorType::VectorType(Type *ElType, ElementCount EC)
+  : SequentialType(VectorTyID, ElType, EC.Min), Scalable(EC.Scalable) {}
 
-VectorType *VectorType::get(Type *ElementType, unsigned NumElements) {
-  assert(NumElements > 0 && "#Elements of a VectorType must be greater than 0");
+VectorType *VectorType::get(Type *ElementType, ElementCount EC) {
+  assert(EC.Min > 0 && "#Elements of a VectorType must be greater than 0");
   assert(isValidElementType(ElementType) && "Element type of a VectorType must "
                                             "be an integer, floating point, or "
                                             "pointer type.");
 
   LLVMContextImpl *pImpl = ElementType->getContext().pImpl;
   VectorType *&Entry = ElementType->getContext().pImpl
-    ->VectorTypes[std::make_pair(ElementType, NumElements)];
-
+                                 ->VectorTypes[std::make_pair(ElementType, EC)];
   if (!Entry)
-    Entry = new (pImpl->Alloc) VectorType(ElementType, NumElements);
+    Entry = new (pImpl->Alloc) VectorType(ElementType, EC);
   return Entry;
 }
 
diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index 0ab421e057d..b0464346557 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -691,6 +691,13 @@ void Verifier::visitGlobalVariable(const GlobalVariable &GV) {
                       "DIGlobalVariableExpression");
   }
 
+  // Scalable vectors cannot be global variables, since we don't know
+  // the runtime size. If the global is a struct or an array containing
+  // scalable vectors, that will be caught by the isValidElementType methods
+  // in StructType or ArrayType instead.
+  if (auto *VTy = dyn_cast<VectorType>(GV.getValueType()))
+    Assert(!VTy->isScalable(), "Globals cannot contain scalable vectors", &GV);
+
   if (!GV.hasInitializer()) {
     visitGlobalValue(GV);
     return;