Remove CompositeType class.

The existence of the class is more confusing than helpful, I think; the
commonality is mostly just "GEP is legal", which can be queried using
APIs on GetElementPtrInst.

Differential Revision: https://reviews.llvm.org/D75660

Author: efriedma-quic

clang/unittests/CodeGen/CodeGenExternalTest.cpp

@@ -199,7 +199,7 @@ static void test_codegen_fns(MyASTConsumer *my) {
           dbgs() << "\n";
         }
 
-        llvm::CompositeType* structTy = dyn_cast<CompositeType>(llvmTy);
+        auto* structTy = dyn_cast<llvm::StructType>(llvmTy);
         ASSERT_TRUE(structTy != NULL);
 
         // Check getLLVMFieldNumber

llvm/include/llvm/IR/Constants.h

@@ -392,7 +392,7 @@ class ConstantAggregateZero final : public ConstantData {
 /// use operands.
 class ConstantAggregate : public Constant {
 protected:
-  ConstantAggregate(CompositeType *T, ValueTy VT, ArrayRef<Constant *> V);
+  ConstantAggregate(Type *T, ValueTy VT, ArrayRef<Constant *> V);
 
 public:
   /// Transparently provide more efficient getOperand methods.

llvm/include/llvm/IR/DerivedTypes.h

@@ -195,26 +195,6 @@ class FunctionCallee {
   Value *Callee = nullptr;
 };
 
-/// Common super class of ArrayType, StructType and VectorType.
-class CompositeType : public Type {
-protected:
-  explicit CompositeType(LLVMContext &C, TypeID tid) : Type(C, tid) {}
-
-public:
-  /// Given an index value into the type, return the type of the element.
-  Type *getTypeAtIndex(const Value *V) const;
-  Type *getTypeAtIndex(unsigned Idx) const;
-  bool indexValid(const Value *V) const;
-  bool indexValid(unsigned Idx) const;
-
-  /// Methods for support type inquiry through isa, cast, and dyn_cast.
-  static bool classof(const Type *T) {
-    return T->getTypeID() == ArrayTyID ||
-           T->getTypeID() == StructTyID ||
-           T->getTypeID() == VectorTyID;
-  }
-};
-
 /// Class to represent struct types. There are two different kinds of struct
 /// types: Literal structs and Identified structs.
 ///
@@ -235,8 +215,8 @@ class CompositeType : public Type {
 /// elements as defined by DataLayout (which is required to match what the code
 /// generator for a target expects).
 ///
-class StructType : public CompositeType {
-  StructType(LLVMContext &C) : CompositeType(C, StructTyID) {}
+class StructType : public Type {
+  StructType(LLVMContext &C) : Type(C, StructTyID) {}
 
   enum {
     /// This is the contents of the SubClassData field.
@@ -350,6 +330,11 @@ class StructType : public CompositeType {
     assert(N < NumContainedTys && "Element number out of range!");
     return ContainedTys[N];
   }
+  /// Given an index value into the type, return the type of the element.
+  Type *getTypeAtIndex(const Value *V) const;
+  Type *getTypeAtIndex(unsigned N) const { return getElementType(N); }
+  bool indexValid(const Value *V) const;
+  bool indexValid(unsigned Idx) const { return Idx < getNumElements(); }
 
   /// Methods for support type inquiry through isa, cast, and dyn_cast.
   static bool classof(const Type *T) {
@@ -375,14 +360,14 @@ Type *Type::getStructElementType(unsigned N) const {
 /// for use of SIMD instructions. SequentialType holds the common features of
 /// both, which stem from the fact that both lay their components out in memory
 /// identically.
-class SequentialType : public CompositeType {
+class SequentialType : public Type {
   Type *ContainedType;               ///< Storage for the single contained type.
   uint64_t NumElements;
 
 protected:
   SequentialType(TypeID TID, Type *ElType, uint64_t NumElements)
-    : CompositeType(ElType->getContext(), TID), ContainedType(ElType),
-      NumElements(NumElements) {
+      : Type(ElType->getContext(), TID), ContainedType(ElType),
+        NumElements(NumElements) {
     ContainedTys = &ContainedType;
     NumContainedTys = 1;
   }

llvm/include/llvm/IR/Instructions.h

@@ -1008,16 +1008,23 @@ class GetElementPtrInst : public Instruction {
     return getPointerAddressSpace();
   }
 
-  /// Returns the type of the element that would be loaded with
-  /// a load instruction with the specified parameters.
+  /// Returns the result type of a getelementptr with the given source
+  /// element type and indexes.
   ///
   /// Null is returned if the indices are invalid for the specified
-  /// pointer type.
-  ///
+  /// source element type.
   static Type *getIndexedType(Type *Ty, ArrayRef<Value *> IdxList);
   static Type *getIndexedType(Type *Ty, ArrayRef<Constant *> IdxList);
   static Type *getIndexedType(Type *Ty, ArrayRef<uint64_t> IdxList);
 
+  /// Return the type of the element at the given index of an indexable
+  /// type.  This is equivalent to "getIndexedType(Agg, {Zero, Idx})".
+  ///
+  /// Returns null if the type can't be indexed, or the given index is not
+  /// legal for the given type.
+  static Type *getTypeAtIndex(Type *Ty, Value *Idx);
+  static Type *getTypeAtIndex(Type *Ty, uint64_t Idx);
+
   inline op_iterator       idx_begin()       { return op_begin()+1; }
   inline const_op_iterator idx_begin() const { return op_begin()+1; }
   inline op_iterator       idx_end()         { return op_end(); }

llvm/lib/CodeGen/Analysis.cpp

@@ -395,7 +395,7 @@ static bool slotOnlyDiscardsData(const Value *RetVal, const Value *CallVal,
 
 /// For an aggregate type, determine whether a given index is within bounds or
 /// not.
-static bool indexReallyValid(CompositeType *T, unsigned Idx) {
+static bool indexReallyValid(Type *T, unsigned Idx) {
   if (ArrayType *AT = dyn_cast<ArrayType>(T))
     return Idx < AT->getNumElements();
 
@@ -419,7 +419,7 @@ static bool indexReallyValid(CompositeType *T, unsigned Idx) {
 /// function again on a finished iterator will repeatedly return
 /// false. SubTypes.back()->getTypeAtIndex(Path.back()) is either an empty
 /// aggregate or a non-aggregate
-static bool advanceToNextLeafType(SmallVectorImpl<CompositeType *> &SubTypes,
+static bool advanceToNextLeafType(SmallVectorImpl<Type *> &SubTypes,
                                   SmallVectorImpl<unsigned> &Path) {
   // First march back up the tree until we can successfully increment one of the
   // coordinates in Path.
@@ -435,16 +435,16 @@ static bool advanceToNextLeafType(SmallVectorImpl<CompositeType *> &SubTypes,
   // We know there's *some* valid leaf now, so march back down the tree picking
   // out the left-most element at each node.
   ++Path.back();
-  Type *DeeperType = SubTypes.back()->getTypeAtIndex(Path.back());
+  Type *DeeperType =
+      ExtractValueInst::getIndexedType(SubTypes.back(), Path.back());
   while (DeeperType->isAggregateType()) {
-    CompositeType *CT = cast<CompositeType>(DeeperType);
-    if (!indexReallyValid(CT, 0))
+    if (!indexReallyValid(DeeperType, 0))
       return true;
 
-    SubTypes.push_back(CT);
+    SubTypes.push_back(DeeperType);
     Path.push_back(0);
 
-    DeeperType = CT->getTypeAtIndex(0U);
+    DeeperType = ExtractValueInst::getIndexedType(DeeperType, 0);
   }
 
   return true;
@@ -460,17 +460,15 @@ static bool advanceToNextLeafType(SmallVectorImpl<CompositeType *> &SubTypes,
 /// For example, if Next was {[0 x i64], {{}, i32, {}}, i32} then we would setup
 /// Path as [1, 1] and SubTypes as [Next, {{}, i32, {}}] to represent the first
 /// i32 in that type.
-static bool firstRealType(Type *Next,
-                          SmallVectorImpl<CompositeType *> &SubTypes,
+static bool firstRealType(Type *Next, SmallVectorImpl<Type *> &SubTypes,
                           SmallVectorImpl<unsigned> &Path) {
   // First initialise the iterator components to the first "leaf" node
   // (i.e. node with no valid sub-type at any index, so {} does count as a leaf
   // despite nominally being an aggregate).
-  while (Next->isAggregateType() &&
-         indexReallyValid(cast<CompositeType>(Next), 0)) {
-    SubTypes.push_back(cast<CompositeType>(Next));
+  while (Type *FirstInner = ExtractValueInst::getIndexedType(Next, 0)) {
+    SubTypes.push_back(Next);
     Path.push_back(0);
-    Next = cast<CompositeType>(Next)->getTypeAtIndex(0U);
+    Next = FirstInner;
   }
 
   // If there's no Path now, Next was originally scalar already (or empty
@@ -480,7 +478,8 @@ static bool firstRealType(Type *Next,
 
   // Otherwise, use normal iteration to keep looking through the tree until we
   // find a non-aggregate type.
-  while (SubTypes.back()->getTypeAtIndex(Path.back())->isAggregateType()) {
+  while (ExtractValueInst::getIndexedType(SubTypes.back(), Path.back())
+             ->isAggregateType()) {
     if (!advanceToNextLeafType(SubTypes, Path))
       return false;
   }
@@ -490,14 +489,15 @@ static bool firstRealType(Type *Next,
 
 /// Set the iterator data-structures to the next non-empty, non-aggregate
 /// subtype.
-static bool nextRealType(SmallVectorImpl<CompositeType *> &SubTypes,
+static bool nextRealType(SmallVectorImpl<Type *> &SubTypes,
                          SmallVectorImpl<unsigned> &Path) {
   do {
     if (!advanceToNextLeafType(SubTypes, Path))
       return false;
 
     assert(!Path.empty() && "found a leaf but didn't set the path?");
-  } while (SubTypes.back()->getTypeAtIndex(Path.back())->isAggregateType());
+  } while (ExtractValueInst::getIndexedType(SubTypes.back(), Path.back())
+               ->isAggregateType());
 
   return true;
 }
@@ -669,7 +669,7 @@ bool llvm::returnTypeIsEligibleForTailCall(const Function *F,
   }
 
   SmallVector<unsigned, 4> RetPath, CallPath;
-  SmallVector<CompositeType *, 4> RetSubTypes, CallSubTypes;
+  SmallVector<Type *, 4> RetSubTypes, CallSubTypes;
 
   bool RetEmpty = !firstRealType(RetVal->getType(), RetSubTypes, RetPath);
   bool CallEmpty = !firstRealType(CallVal->getType(), CallSubTypes, CallPath);
@@ -692,7 +692,8 @@ bool llvm::returnTypeIsEligibleForTailCall(const Function *F,
       // We've exhausted the values produced by the tail call instruction, the
       // rest are essentially undef. The type doesn't really matter, but we need
       // *something*.
-      Type *SlotType = RetSubTypes.back()->getTypeAtIndex(RetPath.back());
+      Type *SlotType =
+          ExtractValueInst::getIndexedType(RetSubTypes.back(), RetPath.back());
       CallVal = UndefValue::get(SlotType);
     }
 

llvm/lib/FuzzMutate/Operations.cpp

@@ -244,20 +244,24 @@ static SourcePred matchScalarInAggregate() {
 
 static SourcePred validInsertValueIndex() {
   auto Pred = [](ArrayRef<Value *> Cur, const Value *V) {
-    auto *CTy = cast<CompositeType>(Cur[0]->getType());
     if (auto *CI = dyn_cast<ConstantInt>(V))
-      if (CI->getBitWidth() == 32 &&
-          CTy->getTypeAtIndex(CI->getZExtValue()) == Cur[1]->getType())
-        return true;
+      if (CI->getBitWidth() == 32) {
+        Type *Indexed = ExtractValueInst::getIndexedType(Cur[0]->getType(),
+                                                         CI->getZExtValue());
+        return Indexed == Cur[1]->getType();
+      }
     return false;
   };
   auto Make = [](ArrayRef<Value *> Cur, ArrayRef<Type *> Ts) {
     std::vector<Constant *> Result;
     auto *Int32Ty = Type::getInt32Ty(Cur[0]->getContext());
-    auto *CTy = cast<CompositeType>(Cur[0]->getType());
-    for (int I = 0, E = getAggregateNumElements(CTy); I < E; ++I)
-      if (CTy->getTypeAtIndex(I) == Cur[1]->getType())
+    auto *BaseTy = Cur[0]->getType();
+    int I = 0;
+    while (Type *Indexed = ExtractValueInst::getIndexedType(BaseTy, I)) {
+      if (Indexed == Cur[1]->getType())
         Result.push_back(ConstantInt::get(Int32Ty, I));
+      ++I;
+    }
     return Result;
   };
   return {Pred, Make};

llvm/lib/IR/ConstantFold.cpp

@@ -2389,10 +2389,11 @@ Constant *llvm::ConstantFoldGetElementPtr(Type *PointeeTy, Constant *C,
   SmallVector<Constant *, 8> NewIdxs;
   Type *Ty = PointeeTy;
   Type *Prev = C->getType();
+  auto GEPIter = gep_type_begin(PointeeTy, Idxs);
   bool Unknown =
       !isa<ConstantInt>(Idxs[0]) && !isa<ConstantDataVector>(Idxs[0]);
   for (unsigned i = 1, e = Idxs.size(); i != e;
-       Prev = Ty, Ty = cast<CompositeType>(Ty)->getTypeAtIndex(Idxs[i]), ++i) {
+       Prev = Ty, Ty = (++GEPIter).getIndexedType(), ++i) {
     if (!isa<ConstantInt>(Idxs[i]) && !isa<ConstantDataVector>(Idxs[i])) {
       // We don't know if it's in range or not.
       Unknown = true;

llvm/lib/IR/Constants.cpp

@@ -1047,19 +1047,20 @@ static Constant *getSequenceIfElementsMatch(Constant *C,
   return nullptr;
 }
 
-ConstantAggregate::ConstantAggregate(CompositeType *T, ValueTy VT,
+ConstantAggregate::ConstantAggregate(Type *T, ValueTy VT,
                                      ArrayRef<Constant *> V)
     : Constant(T, VT, OperandTraits<ConstantAggregate>::op_end(this) - V.size(),
                V.size()) {
   llvm::copy(V, op_begin());
 
   // Check that types match, unless this is an opaque struct.
-  if (auto *ST = dyn_cast<StructType>(T))
+  if (auto *ST = dyn_cast<StructType>(T)) {
     if (ST->isOpaque())
       return;
-  for (unsigned I = 0, E = V.size(); I != E; ++I)
-    assert(V[I]->getType() == T->getTypeAtIndex(I) &&
-           "Initializer for composite element doesn't match!");
+    for (unsigned I = 0, E = V.size(); I != E; ++I)
+      assert(V[I]->getType() == ST->getTypeAtIndex(I) &&
+             "Initializer for struct element doesn't match!");
+  }
 }
 
 ConstantArray::ConstantArray(ArrayType *T, ArrayRef<Constant *> V)

llvm/lib/IR/Instructions.cpp

@@ -1659,35 +1659,44 @@ GetElementPtrInst::GetElementPtrInst(const GetElementPtrInst &GEPI)
   SubclassOptionalData = GEPI.SubclassOptionalData;
 }
 
-/// getIndexedType - Returns the type of the element that would be accessed with
-/// a gep instruction with the specified parameters.
-///
-/// The Idxs pointer should point to a continuous piece of memory containing the
-/// indices, either as Value* or uint64_t.
-///
-/// A null type is returned if the indices are invalid for the specified
-/// pointer type.
-///
-template <typename IndexTy>
-static Type *getIndexedTypeInternal(Type *Agg, ArrayRef<IndexTy> IdxList) {
-  // Handle the special case of the empty set index set, which is always valid.
-  if (IdxList.empty())
-    return Agg;
-
-  // If there is at least one index, the top level type must be sized, otherwise
-  // it cannot be 'stepped over'.
-  if (!Agg->isSized())
+Type *GetElementPtrInst::getTypeAtIndex(Type *Ty, Value *Idx) {
+  if (auto Struct = dyn_cast<StructType>(Ty)) {
+    if (!Struct->indexValid(Idx))
+      return nullptr;
+    return Struct->getTypeAtIndex(Idx);
+  }
+  if (!Idx->getType()->isIntOrIntVectorTy())
     return nullptr;
+  if (auto Array = dyn_cast<ArrayType>(Ty))
+    return Array->getElementType();
+  if (auto Vector = dyn_cast<VectorType>(Ty))
+    return Vector->getElementType();
+  return nullptr;
+}
 
-  unsigned CurIdx = 1;
-  for (; CurIdx != IdxList.size(); ++CurIdx) {
-    CompositeType *CT = dyn_cast<CompositeType>(Agg);
-    if (!CT || CT->isPointerTy()) return nullptr;
-    IndexTy Index = IdxList[CurIdx];
-    if (!CT->indexValid(Index)) return nullptr;
-    Agg = CT->getTypeAtIndex(Index);
+Type *GetElementPtrInst::getTypeAtIndex(Type *Ty, uint64_t Idx) {
+  if (auto Struct = dyn_cast<StructType>(Ty)) {
+    if (Idx >= Struct->getNumElements())
+      return nullptr;
+    return Struct->getElementType(Idx);
   }
-  return CurIdx == IdxList.size() ? Agg : nullptr;
+  if (auto Array = dyn_cast<ArrayType>(Ty))
+    return Array->getElementType();
+  if (auto Vector = dyn_cast<VectorType>(Ty))
+    return Vector->getElementType();
+  return nullptr;
+}
+
+template <typename IndexTy>
+static Type *getIndexedTypeInternal(Type *Ty, ArrayRef<IndexTy> IdxList) {
+  if (IdxList.empty())
+    return Ty;
+  for (IndexTy V : IdxList.slice(1)) {
+    Ty = GetElementPtrInst::getTypeAtIndex(Ty, V);
+    if (!Ty)
+      return Ty;
+  }
+  return Ty;
 }
 
 Type *GetElementPtrInst::getIndexedType(Type *Ty, ArrayRef<Value *> IdxList) {
@@ -2220,15 +2229,15 @@ Type *ExtractValueInst::getIndexedType(Type *Agg,
     if (ArrayType *AT = dyn_cast<ArrayType>(Agg)) {
       if (Index >= AT->getNumElements())
         return nullptr;
+      Agg = AT->getElementType();
     } else if (StructType *ST = dyn_cast<StructType>(Agg)) {
       if (Index >= ST->getNumElements())
         return nullptr;
+      Agg = ST->getElementType(Index);
     } else {
       // Not a valid type to index into.
       return nullptr;
     }
-
-    Agg = cast<CompositeType>(Agg)->getTypeAtIndex(Index);
   }
   return const_cast<Type*>(Agg);
 }