Allow passing Visited set into Type::isScalableTy

Author: jayfoad

llvm/include/llvm/IR/DerivedTypes.h

@@ -290,7 +290,8 @@ class StructType : public Type {
   bool isSized(SmallPtrSetImpl<Type *> *Visited = nullptr) const;
 
   /// Returns true if this struct contains a scalable vector.
-  bool isScalableTy(SmallPtrSetImpl<Type *> *Visited = nullptr) const;
+  bool isScalableTy(SmallPtrSetImpl<Type *> &Visited) const;
+  using Type::isScalableTy;
 
   /// Returns true if this struct contains homogeneous scalable vector types.
   /// Note that the definition of homogeneous scalable vector type is not

llvm/include/llvm/IR/Type.h

@@ -206,6 +206,7 @@ class Type {
   bool isScalableTargetExtTy() const;
 
   /// Return true if this is a type whose size is a known multiple of vscale.
+  bool isScalableTy(SmallPtrSetImpl<Type *> &Visited) const;
   bool isScalableTy() const;
 
   /// Return true if this is a FP type or a vector of FP.

llvm/lib/IR/Type.cpp

@@ -58,16 +58,19 @@ bool Type::isIntegerTy(unsigned Bitwidth) const {
   return isIntegerTy() && cast<IntegerType>(this)->getBitWidth() == Bitwidth;
 }
 
-bool Type::isScalableTy() const {
+bool Type::isScalableTy(SmallPtrSetImpl<Type *> &Visited) const {
   if (const auto *ATy = dyn_cast<ArrayType>(this))
-    return ATy->getElementType()->isScalableTy();
-  if (const auto *STy = dyn_cast<StructType>(this)) {
-    SmallPtrSet<Type *, 4> Visited;
-    return STy->isScalableTy(&Visited);
-  }
+    return ATy->getElementType()->isScalableTy(Visited);
+  if (const auto *STy = dyn_cast<StructType>(this))
+    return STy->isScalableTy(Visited);
   return getTypeID() == ScalableVectorTyID || isScalableTargetExtTy();
 }
 
+bool Type::isScalableTy() const {
+  SmallPtrSet<Type *, 4> Visited;
+  return isScalableTy(Visited);
+}
+
 const fltSemantics &Type::getFltSemantics() const {
   switch (getTypeID()) {
   case HalfTyID: return APFloat::IEEEhalf();
@@ -394,14 +397,14 @@ StructType *StructType::get(LLVMContext &Context, ArrayRef<Type*> ETypes,
   return ST;
 }
 
-bool StructType::isScalableTy(SmallPtrSetImpl<Type *> *Visited) const {
+bool StructType::isScalableTy(SmallPtrSetImpl<Type *> &Visited) const {
   if ((getSubclassData() & SCDB_ContainsScalableVector) != 0)
     return true;
 
   if ((getSubclassData() & SCDB_NotContainsScalableVector) != 0)
     return false;
 
-  if (Visited && !Visited->insert(const_cast<StructType *>(this)).second)
+  if (!Visited.insert(const_cast<StructType *>(this)).second)
     return false;
 
   for (Type *Ty : elements()) {