[clang][CodeGen] Factor out Swift ABI hooks (NFCI)

[barannikov88]

Summary

Swift calling conventions stands out in the way that they are lowered in
mostly target-independent manner, with very few customization points.
As such, swift-related methods of ABIInfo do not reference the rest of
ABIInfo and vice versa.
This change follows interface segregation principle; it removes
dependency of SwiftABIInfo on ABIInfo. Targets must now implement
SwiftABIInfo separately if they support Swift calling conventions.

Almost all targets implemented shouldPassIndirectly the same way. This
de-facto default implementation has been moved into the base class.

isSwiftErrorInRegister used to be virtual, now it is not. It didn't
accept any arguments which could have an effect on the returned value.
This is now a static property of the target ABI.

[barannikov88]

Reword commit message.

[barannikov88]

Kindly ping

[barannikov88]

Ping

[barannikov88]

Ping

[barannikov88]

Ping

[aaron.ballman]

This seems like a reasonable set of changes, but I'd prefer someone more well-versed in codegen make the final call.

clang/lib/CodeGen/TargetInfo.h

63

SwiftInfo isn't always initialized to a nonnull pointer; should this have an assert to help point out when someone's forgotten to initialize that properly?

[barannikov88]

clang/lib/CodeGen/TargetInfo.h

63

Good point, thank you

[barannikov88]

Rebase

[barannikov88]

Assert that Swift ABI info is initialized before accessing it.

[rusyaev-roman]

LGTM. Maybe in the future it's better to use SwiftABIInfo as mix-in like this

class ARMABIInfo : public ABIInfo, public SwiftABIInfo

[inclyc]

(Not a serious review) It seems like that your patch has already been accepted, so that I can commit this patch for you.

[barannikov88]

In D130394#3705047, @inclyc wrote:

(Not a serious review) It seems like that your patch has already been accepted, so that I can commit this patch for you.

It was very nice of you, thanks!

[inclyc]

I think in fact you are now fully qualified to apply for commit access. Don't worry, Lattner generally trusts all developers willing to contribute to LLVM.

clang/lib/CodeGen/ABIInfo.h

 
 namespace CodeGen {
   class ABIArgInfo;
   class Address;
   class CGCXXABI;
   class CGFunctionInfo;
   class CodeGenFunction;
   class CodeGenTypes;
-  class SwiftABIInfo;
 
   // FIXME: All of this stuff should be part of the target interface
   // somehow. It is currently here because it is not clear how to factor
   // the targets to support this, since the Targets currently live in a
   // layer below types n'stuff.
 
 
   /// ABIInfo - Target specific hooks for defining how a type should be
   /// passed or returned from functions.
   class ABIInfo {
-  public:
-    CodeGen::CodeGenTypes &CGT;
   protected:
+    CodeGen::CodeGenTypes &CGT;
     llvm::CallingConv::ID RuntimeCC;
   public:
     ABIInfo(CodeGen::CodeGenTypes &cgt)
         : CGT(cgt), RuntimeCC(llvm::CallingConv::C) {}
 
     virtual ~ABIInfo();
 
-    virtual bool supportsSwift() const { return false; }
-
     virtual bool allowBFloatArgsAndRet() const { return false; }
 
     CodeGen::CGCXXABI &getCXXABI() const;
     ASTContext &getContext() const;
     llvm::LLVMContext &getVMContext() const;
     const llvm::DataLayout &getDataLayout() const;
     const TargetInfo &getTarget() const;
     const CodeGenOptions &getCodeGenOpts() const;
public:
     /// expected alignment equal to the ABI alignment of the given type.
     CodeGen::ABIArgInfo
     getNaturalAlignIndirect(QualType Ty, bool ByVal = true,
                             bool Realign = false,
                             llvm::Type *Padding = nullptr) const;
 
     CodeGen::ABIArgInfo
     getNaturalAlignIndirectInReg(QualType Ty, bool Realign = false) const;
-
-
   };
 
-  /// A refining implementation of ABIInfo for targets that support swiftcall.
-  ///
-  /// If we find ourselves wanting multiple such refinements, they'll probably
-  /// be independent refinements, and we should probably find another way
-  /// to do it than simple inheritance.
-  class SwiftABIInfo : public ABIInfo {
-  public:
-    SwiftABIInfo(CodeGen::CodeGenTypes &cgt) : ABIInfo(cgt) {}
-
-    bool supportsSwift() const final { return true; }
+  /// Target specific hooks for defining how a type should be passed or returned
+  /// from functions with one of the Swift calling conventions.
+  class SwiftABIInfo {
+  protected:
+    CodeGenTypes &CGT;
+    bool SwiftErrorInRegister;
 
-    virtual bool shouldPassIndirectlyForSwift(ArrayRef<llvm::Type*> types,
-                                              bool asReturnValue) const = 0;
+  public:
+    SwiftABIInfo(CodeGen::CodeGenTypes &CGT, bool SwiftErrorInRegister)
+        : CGT(CGT), SwiftErrorInRegister(SwiftErrorInRegister) {}
 
-    virtual bool isLegalVectorTypeForSwift(CharUnits totalSize,
-                                           llvm::Type *eltTy,
-                                           unsigned elts) const;
+    virtual ~SwiftABIInfo();
 
-    virtual bool isSwiftErrorInRegister() const = 0;
+    /// Returns true if an aggregate which expands to the given type sequence
+    /// should be passed / returned indirectly.
+    virtual bool shouldPassIndirectly(ArrayRef<llvm::Type *> ComponentTys,
+                                      bool AsReturnValue) const;
+
+    /// Returns true if the given vector type is legal from Swift's calling
+    /// convention perspective.
+    virtual bool isLegalVectorType(CharUnits VectorSize, llvm::Type *EltTy,
+                                   unsigned NumElts) const;
 
-    static bool classof(const ABIInfo *info) {
-      return info->supportsSwift();
-    }
+    /// Returns true if swifterror is lowered to a register by the target ABI.
+    bool isSwiftErrorInRegister() const { return SwiftErrorInRegister; };
   };
 }  // end namespace CodeGen
 }  // end namespace clang
 
 #endif

clang/lib/CodeGen/SwiftCallingConv.cpp

 #include "TargetInfo.h"
 #include "clang/Basic/TargetInfo.h"
 
 using namespace clang;
 using namespace CodeGen;
 using namespace swiftcall;
 
 static const SwiftABIInfo &getSwiftABIInfo(CodeGenModule &CGM) {
-  return cast<SwiftABIInfo>(CGM.getTargetCodeGenInfo().getABIInfo());
+  return CGM.getTargetCodeGenInfo().getSwiftABIInfo();
 }
 
 static bool isPowerOf2(unsigned n) {
   return n == (n & -n);
 }
 
 /// Given two types with the same size, try to find a common type.
 static llvm::Type *getCommonType(llvm::Type *first, llvm::Type *second) {

 bool SwiftAggLowering::shouldPassIndirectly(bool asReturnValue) const {
   assert(Finished && "haven't yet finished lowering");
 
   // Empty types don't need to be passed indirectly.
   if (Entries.empty()) return false;
 
   // Avoid copying the array of types when there's just a single element.
   if (Entries.size() == 1) {
-    return getSwiftABIInfo(CGM).shouldPassIndirectlyForSwift(
-                                                           Entries.back().Type,
-                                                             asReturnValue);
+    return getSwiftABIInfo(CGM).shouldPassIndirectly(Entries.back().Type,
   }
 
   SmallVector<llvm::Type*, 8> componentTys;
   componentTys.reserve(Entries.size());
   for (auto &entry : Entries) {
     componentTys.push_back(entry.Type);
   }
-  return getSwiftABIInfo(CGM).shouldPassIndirectlyForSwift(componentTys,
-                                                           asReturnValue);
+  return getSwiftABIInfo(CGM).shouldPassIndirectly(componentTys, asReturnValue);
 }
 
 bool swiftcall::shouldPassIndirectly(CodeGenModule &CGM,
                                      ArrayRef<llvm::Type*> componentTys,
                                      bool asReturnValue) {
-  return getSwiftABIInfo(CGM).shouldPassIndirectlyForSwift(componentTys,
-                                                           asReturnValue);
+  return getSwiftABIInfo(CGM).shouldPassIndirectly(componentTys, asReturnValue);
 }
 
 CharUnits swiftcall::getMaximumVoluntaryIntegerSize(CodeGenModule &CGM) {
   // Currently always the size of an ordinary pointer.
   return CGM.getContext().toCharUnitsFromBits(
            CGM.getContext().getTargetInfo().getPointerWidth(0));
 }
 
bool swiftcall::isLegalVectorType(CodeGenModule &CGM, CharUnits vectorSize,
   return isLegalVectorType(
       CGM, vectorSize, vectorTy->getElementType(),
       cast<llvm::FixedVectorType>(vectorTy)->getNumElements());
 }
 
 bool swiftcall::isLegalVectorType(CodeGenModule &CGM, CharUnits vectorSize,
                                   llvm::Type *eltTy, unsigned numElts) {
   assert(numElts > 1 && "illegal vector length");
-  return getSwiftABIInfo(CGM)
-           .isLegalVectorTypeForSwift(vectorSize, eltTy, numElts);
+  return getSwiftABIInfo(CGM).isLegalVectorType(vectorSize, eltTy, numElts);
 }
 
 std::pair<llvm::Type*, unsigned>
 swiftcall::splitLegalVectorType(CodeGenModule &CGM, CharUnits vectorSize,
                                 llvm::VectorType *vectorTy) {
   auto numElts = cast<llvm::FixedVectorType>(vectorTy)->getNumElements();
   auto eltTy = vectorTy->getElementType();
 

clang/lib/CodeGen/TargetInfo.h

 namespace clang {
 class Decl;
 
 namespace CodeGen {
 class ABIInfo;
 class CallArgList;
 class CodeGenFunction;
 class CGBlockInfo;
+class SwiftABIInfo;
 
 /// TargetCodeGenInfo - This class organizes various target-specific
 /// codegeneration issues, like target-specific attributes, builtins and so
 /// on.
 class TargetCodeGenInfo {
   std::unique_ptr<ABIInfo> Info;
 
+protected:
+  // Target hooks supporting Swift calling conventions. The target must
+  // initialize this field if it claims to support these calling conventions
+  // by returning true from TargetInfo::checkCallingConvention for them.
+  std::unique_ptr<SwiftABIInfo> SwiftInfo;
+
 public:
   TargetCodeGenInfo(std::unique_ptr<ABIInfo> Info);
   virtual ~TargetCodeGenInfo();
 
   /// getABIInfo() - Returns ABI info helper for the target.
   const ABIInfo &getABIInfo() const { return *Info; }
 
+  /// Returns Swift ABI info helper for the target.
+  const SwiftABIInfo &getSwiftABIInfo() const {
+    assert(SwiftInfo && "Swift ABI info has not been initialized");
+    return *SwiftInfo;
+  }
+
   /// setTargetAttributes - Provides a convenient hook to handle extra
   /// target-specific attributes for the given global.
   virtual void setTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
                                    CodeGen::CodeGenModule &M) const {}
 
   /// emitTargetMetadata - Provides a convenient hook to handle extra
   /// target-specific metadata for the given globals.
   virtual void emitTargetMetadata(

clang/lib/CodeGen/TargetInfo.cpp

 #include "CGValue.h"
 #include "CodeGenFunction.h"
 #include "clang/AST/Attr.h"
 #include "clang/AST/RecordLayout.h"
 #include "clang/Basic/Builtins.h"
 #include "clang/Basic/CodeGenOptions.h"
 #include "clang/Basic/DiagnosticFrontend.h"
 #include "clang/CodeGen/CGFunctionInfo.h"
-#include "clang/CodeGen/SwiftCallingConv.h"
 #include "llvm/ADT/SmallBitVector.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/IntrinsicsNVPTX.h"
 #include "llvm/IR/IntrinsicsS390.h"
bool ABIInfo::isPromotableIntegerTypeForABI(QualType Ty) const {
 
   if (const auto *EIT = Ty->getAs<BitIntType>())
     if (EIT->getNumBits() < getContext().getTypeSize(getContext().IntTy))
       return true;
 
   return false;
 }
 
-ABIInfo::~ABIInfo() {}
+ABIInfo::~ABIInfo() = default;
+
+SwiftABIInfo::~SwiftABIInfo() = default;
 
 /// Does the given lowering require more than the given number of
 /// registers when expanded?
 ///
 /// This is intended to be the basis of a reasonable basic implementation
 /// of should{Pass,Return}IndirectlyForSwift.
 ///
 /// For most targets, a limit of four total registers is reasonable; this
if (type->isPointerTy()) {
       assert(type->isVectorTy() || type->isFloatingPointTy());
       fpCount++;
     }
   }
 
   return (intCount + fpCount > maxAllRegisters);
 }
 
-bool SwiftABIInfo::isLegalVectorTypeForSwift(CharUnits vectorSize,
-                                             llvm::Type *eltTy,
-                                             unsigned numElts) const {
+bool SwiftABIInfo::shouldPassIndirectly(ArrayRef<llvm::Type *> ComponentTys,
+                                        bool AsReturnValue) const {
+  return occupiesMoreThan(CGT, ComponentTys, /*total=*/4);
+}
+
+bool SwiftABIInfo::isLegalVectorType(CharUnits VectorSize, llvm::Type *EltTy,
+                                     unsigned NumElts) const {
   // The default implementation of this assumes that the target guarantees
   // 128-bit SIMD support but nothing more.
-  return (vectorSize.getQuantity() > 8 && vectorSize.getQuantity() <= 16);
+  return (VectorSize.getQuantity() > 8 && VectorSize.getQuantity() <= 16);
 }
 
 static CGCXXABI::RecordArgABI getRecordArgABI(const RecordType *RT,
                                               CGCXXABI &CXXABI) {
   const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl());
   if (!RD) {
     if (!RT->getDecl()->canPassInRegisters())
       return CGCXXABI::RAA_Indirect;

 }
 
 //===----------------------------------------------------------------------===//
 // WebAssembly ABI Implementation
 //
 // This is a very simple ABI that relies a lot on DefaultABIInfo.
 //===----------------------------------------------------------------------===//
 
-class WebAssemblyABIInfo final : public SwiftABIInfo {
+class WebAssemblyABIInfo final : public ABIInfo {
 public:
   enum ABIKind {
     MVP = 0,
     ExperimentalMV = 1,
   };
 
 private:
   DefaultABIInfo defaultInfo;
   ABIKind Kind;
 
 public:
   explicit WebAssemblyABIInfo(CodeGen::CodeGenTypes &CGT, ABIKind Kind)
-      : SwiftABIInfo(CGT), defaultInfo(CGT), Kind(Kind) {}
+      : ABIInfo(CGT), defaultInfo(CGT), Kind(Kind) {}
 
 private:
   ABIArgInfo classifyReturnType(QualType RetTy) const;
   ABIArgInfo classifyArgumentType(QualType Ty) const;
 
   // DefaultABIInfo's classifyReturnType and classifyArgumentType are
   // non-virtual, but computeInfo and EmitVAArg are virtual, so we
   // overload them.
   void computeInfo(CGFunctionInfo &FI) const override {
     if (!getCXXABI().classifyReturnType(FI))
       FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
     for (auto &Arg : FI.arguments())
       Arg.info = classifyArgumentType(Arg.type);
   }
 
   Address EmitVAArg(CodeGenFunction &CGF, Address VAListAddr,
                     QualType Ty) const override;
-
-  bool shouldPassIndirectlyForSwift(ArrayRef<llvm::Type*> scalars,
-                                    bool asReturnValue) const override {
-    return occupiesMoreThan(CGT, scalars, /*total*/ 4);
-  }
-
-  bool isSwiftErrorInRegister() const override {
-    return false;
-  }
 };
 
 class WebAssemblyTargetCodeGenInfo final : public TargetCodeGenInfo {
 public:
   explicit WebAssemblyTargetCodeGenInfo(CodeGen::CodeGenTypes &CGT,
                                         WebAssemblyABIInfo::ABIKind K)
-      : TargetCodeGenInfo(std::make_unique<WebAssemblyABIInfo>(CGT, K)) {}
+      : TargetCodeGenInfo(std::make_unique<WebAssemblyABIInfo>(CGT, K)) {
+    SwiftInfo =
+        std::make_unique<SwiftABIInfo>(CGT, /*SwiftErrorInRegister=*/false);
+  }
 
   void setTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
                            CodeGen::CodeGenModule &CGM) const override {
     TargetCodeGenInfo::setTargetAttributes(D, GV, CGM);
     if (const auto *FD = dyn_cast_or_null<FunctionDecl>(D)) {
       if (const auto *Attr = FD->getAttr<WebAssemblyImportModuleAttr>()) {
         llvm::Function *Fn = cast<llvm::Function>(GV);
         llvm::AttrBuilder B(GV->getContext());
struct CCState {
 
   llvm::SmallBitVector IsPreassigned;
   unsigned CC = CallingConv::CC_C;
   unsigned FreeRegs = 0;
   unsigned FreeSSERegs = 0;
 };
 
 /// X86_32ABIInfo - The X86-32 ABI information.
-class X86_32ABIInfo : public SwiftABIInfo {
+class X86_32ABIInfo : public ABIInfo {
   enum Class {
     Integer,
     Float
   };
 
   static const unsigned MinABIStackAlignInBytes = 4;
 
   bool IsDarwinVectorABI;
public:
 
   void computeInfo(CGFunctionInfo &FI) const override;
   Address EmitVAArg(CodeGenFunction &CGF, Address VAListAddr,
                     QualType Ty) const override;
 
   X86_32ABIInfo(CodeGen::CodeGenTypes &CGT, bool DarwinVectorABI,
                 bool RetSmallStructInRegABI, bool Win32StructABI,
                 unsigned NumRegisterParameters, bool SoftFloatABI)
-    : SwiftABIInfo(CGT), IsDarwinVectorABI(DarwinVectorABI),
+      : ABIInfo(CGT), IsDarwinVectorABI(DarwinVectorABI),
         IsRetSmallStructInRegABI(RetSmallStructInRegABI),
         IsWin32StructABI(Win32StructABI), IsSoftFloatABI(SoftFloatABI),
         IsMCUABI(CGT.getTarget().getTriple().isOSIAMCU()),
         IsLinuxABI(CGT.getTarget().getTriple().isOSLinux() ||
                    CGT.getTarget().getTriple().isOSCygMing()),
         DefaultNumRegisterParameters(NumRegisterParameters) {}
+};
 
-  bool shouldPassIndirectlyForSwift(ArrayRef<llvm::Type*> scalars,
-                                    bool asReturnValue) const override {
+class X86_32SwiftABIInfo : public SwiftABIInfo {
+public:
+  explicit X86_32SwiftABIInfo(CodeGenTypes &CGT)
+      : SwiftABIInfo(CGT, /*SwiftErrorInRegister=*/false) {}
+
+  bool shouldPassIndirectly(ArrayRef<llvm::Type *> ComponentTys,
+                            bool AsReturnValue) const override {
     // LLVM's x86-32 lowering currently only assigns up to three
     // integer registers and three fp registers.  Oddly, it'll use up to
     // four vector registers for vectors, but those can overlap with the
     // scalar registers.
-    return occupiesMoreThan(CGT, scalars, /*total*/ 3);
-  }
-
-  bool isSwiftErrorInRegister() const override {
-    // x86-32 lowering does not support passing swifterror in a register.
-    return false;
+    return occupiesMoreThan(CGT, ComponentTys, /*total=*/3);
   }
 };
 
 class X86_32TargetCodeGenInfo : public TargetCodeGenInfo {
 public:
   X86_32TargetCodeGenInfo(CodeGen::CodeGenTypes &CGT, bool DarwinVectorABI,
                           bool RetSmallStructInRegABI, bool Win32StructABI,
                           unsigned NumRegisterParameters, bool SoftFloatABI)
       : TargetCodeGenInfo(std::make_unique<X86_32ABIInfo>(
             CGT, DarwinVectorABI, RetSmallStructInRegABI, Win32StructABI,
-            NumRegisterParameters, SoftFloatABI)) {}
+            NumRegisterParameters, SoftFloatABI)) {
+    SwiftInfo = std::make_unique<X86_32SwiftABIInfo>(CGT);
+  }
 
   static bool isStructReturnInRegABI(
       const llvm::Triple &Triple, const CodeGenOptions &Opts);
 
   void setTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
                            CodeGen::CodeGenModule &CGM) const override;
 
   int getDwarfEHStackPointer(CodeGen::CodeGenModule &CGM) const override {
case X86AVXABILevel::AVX:
     return 256;
   case X86AVXABILevel::None:
     return 128;
   }
   llvm_unreachable("Unknown AVXLevel");
 }
 
 /// X86_64ABIInfo - The X86_64 ABI information.
-class X86_64ABIInfo : public SwiftABIInfo {
+class X86_64ABIInfo : public ABIInfo {
   enum Class {
     Integer = 0,
     SSE,
     SSEUp,
     X87,
     X87Up,
     ComplexX87,
     NoClass,
class X86_64ABIInfo : public ABIInfo {
   }
 
   X86AVXABILevel AVXLevel;
   // Some ABIs (e.g. X32 ABI and Native Client OS) use 32 bit pointers on
   // 64-bit hardware.
   bool Has64BitPointers;
 
 public:
-  X86_64ABIInfo(CodeGen::CodeGenTypes &CGT, X86AVXABILevel AVXLevel) :
-      SwiftABIInfo(CGT), AVXLevel(AVXLevel),
-      Has64BitPointers(CGT.getDataLayout().getPointerSize(0) == 8) {
-  }
+  X86_64ABIInfo(CodeGen::CodeGenTypes &CGT, X86AVXABILevel AVXLevel)
+      : ABIInfo(CGT), AVXLevel(AVXLevel),
+        Has64BitPointers(CGT.getDataLayout().getPointerSize(0) == 8) {}
 
   bool isPassedUsingAVXType(QualType type) const {
     unsigned neededInt, neededSSE;
     // The freeIntRegs argument doesn't matter here.
     ABIArgInfo info = classifyArgumentType(type, 0, neededInt, neededSSE,
                                            /*isNamedArg*/true);
     if (info.isDirect()) {
       llvm::Type *ty = info.getCoerceToType();
       if (llvm::VectorType *vectorTy = dyn_cast_or_null<llvm::VectorType>(ty))
         return vectorTy->getPrimitiveSizeInBits().getFixedSize() > 128;
     }
     return false;
   }
 
   void computeInfo(CGFunctionInfo &FI) const override;
 
   Address EmitVAArg(CodeGenFunction &CGF, Address VAListAddr,
                     QualType Ty) const override;
   Address EmitMSVAArg(CodeGenFunction &CGF, Address VAListAddr,
                       QualType Ty) const override;
 
   bool has64BitPointers() const {
     return Has64BitPointers;
   }
-
-  bool shouldPassIndirectlyForSwift(ArrayRef<llvm::Type*> scalars,
-                                    bool asReturnValue) const override {
-    return occupiesMoreThan(CGT, scalars, /*total*/ 4);
-  }
-  bool isSwiftErrorInRegister() const override {
-    return true;
-  }
 };
 
 /// WinX86_64ABIInfo - The Windows X86_64 ABI information.
-class WinX86_64ABIInfo : public SwiftABIInfo {
+class WinX86_64ABIInfo : public ABIInfo {
 public:
   WinX86_64ABIInfo(CodeGen::CodeGenTypes &CGT, X86AVXABILevel AVXLevel)
-      : SwiftABIInfo(CGT), AVXLevel(AVXLevel),
+      : ABIInfo(CGT), AVXLevel(AVXLevel),
         IsMingw64(getTarget().getTriple().isWindowsGNUEnvironment()) {}
 
   void computeInfo(CGFunctionInfo &FI) const override;
 
   Address EmitVAArg(CodeGenFunction &CGF, Address VAListAddr,
                     QualType Ty) const override;
 
   bool isHomogeneousAggregateBaseType(QualType Ty) const override {
     // FIXME: Assumes vectorcall is in use.
     return isX86VectorTypeForVectorCall(getContext(), Ty);
   }
 
   bool isHomogeneousAggregateSmallEnough(const Type *Ty,
                                          uint64_t NumMembers) const override {
     // FIXME: Assumes vectorcall is in use.
     return isX86VectorCallAggregateSmallEnough(NumMembers);
   }
 
-  bool shouldPassIndirectlyForSwift(ArrayRef<llvm::Type *> scalars,
-                                    bool asReturnValue) const override {
-    return occupiesMoreThan(CGT, scalars, /*total*/ 4);
-  }
-
-  bool isSwiftErrorInRegister() const override {
-    return true;
-  }
-
 private:
   ABIArgInfo classify(QualType Ty, unsigned &FreeSSERegs, bool IsReturnType,
                       bool IsVectorCall, bool IsRegCall) const;
   ABIArgInfo reclassifyHvaArgForVectorCall(QualType Ty, unsigned &FreeSSERegs,
                                            const ABIArgInfo &current) const;
 
   X86AVXABILevel AVXLevel;
 
   bool IsMingw64;
 };
 
 class X86_64TargetCodeGenInfo : public TargetCodeGenInfo {
 public:
   X86_64TargetCodeGenInfo(CodeGen::CodeGenTypes &CGT, X86AVXABILevel AVXLevel)
-      : TargetCodeGenInfo(std::make_unique<X86_64ABIInfo>(CGT, AVXLevel)) {}
+      : TargetCodeGenInfo(std::make_unique<X86_64ABIInfo>(CGT, AVXLevel)) {
+    SwiftInfo =
+        std::make_unique<SwiftABIInfo>(CGT, /*SwiftErrorInRegister=*/true);
+  }
 
   const X86_64ABIInfo &getABIInfo() const {
     return static_cast<const X86_64ABIInfo&>(TargetCodeGenInfo::getABIInfo());
   }
 
   /// Disable tail call on x86-64. The epilogue code before the tail jump blocks
   /// autoreleaseRV/retainRV and autoreleaseRV/unsafeClaimRV optimizations.
   bool markARCOptimizedReturnCallsAsNoTail() const override { return true; }
if (GV->isDeclaration())
     return;
   addStackProbeTargetAttributes(D, GV, CGM);
 }
 
 class WinX86_64TargetCodeGenInfo : public TargetCodeGenInfo {
 public:
   WinX86_64TargetCodeGenInfo(CodeGen::CodeGenTypes &CGT,
                              X86AVXABILevel AVXLevel)
-      : TargetCodeGenInfo(std::make_unique<WinX86_64ABIInfo>(CGT, AVXLevel)) {}
+      : TargetCodeGenInfo(std::make_unique<WinX86_64ABIInfo>(CGT, AVXLevel)) {
+    SwiftInfo =
+        std::make_unique<SwiftABIInfo>(CGT, /*SwiftErrorInRegister=*/true);
+  }
 
   void setTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
                            CodeGen::CodeGenModule &CGM) const override;
 
   int getDwarfEHStackPointer(CodeGen::CodeGenModule &CGM) const override {
     return 7;
   }
 
PPC32TargetCodeGenInfo::initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
   return PPC_initDwarfEHRegSizeTable(CGF, Address, /*Is64Bit*/ false,
                                      /*IsAIX*/ false);
 }
 
 // PowerPC-64
 
 namespace {
 /// PPC64_SVR4_ABIInfo - The 64-bit PowerPC ELF (SVR4) ABI information.
-class PPC64_SVR4_ABIInfo : public SwiftABIInfo {
+class PPC64_SVR4_ABIInfo : public ABIInfo {
 public:
   enum ABIKind {
     ELFv1 = 0,
     ELFv2
   };
 
 private:
   static const unsigned GPRBits = 64;
   ABIKind Kind;
   bool IsSoftFloatABI;
 
 public:
   PPC64_SVR4_ABIInfo(CodeGen::CodeGenTypes &CGT, ABIKind Kind,
                      bool SoftFloatABI)
-      : SwiftABIInfo(CGT), Kind(Kind), IsSoftFloatABI(SoftFloatABI) {}
+      : ABIInfo(CGT), Kind(Kind), IsSoftFloatABI(SoftFloatABI) {}
 
   bool isPromotableTypeForABI(QualType Ty) const;
   CharUnits getParamTypeAlignment(QualType Ty) const;
 
   ABIArgInfo classifyReturnType(QualType RetTy) const;
   ABIArgInfo classifyArgumentType(QualType Ty) const;
 
   bool isHomogeneousAggregateBaseType(QualType Ty) const override;
for (auto &I : FI.arguments()) {
         }
       }
       I.info = classifyArgumentType(I.type);
     }
   }
 
   Address EmitVAArg(CodeGenFunction &CGF, Address VAListAddr,
                     QualType Ty) const override;
-
-  bool shouldPassIndirectlyForSwift(ArrayRef<llvm::Type*> scalars,
-                                    bool asReturnValue) const override {
-    return occupiesMoreThan(CGT, scalars, /*total*/ 4);
-  }
-
-  bool isSwiftErrorInRegister() const override {
-    return false;
-  }
 };
 
 class PPC64_SVR4_TargetCodeGenInfo : public TargetCodeGenInfo {
 
 public:
   PPC64_SVR4_TargetCodeGenInfo(CodeGenTypes &CGT,
                                PPC64_SVR4_ABIInfo::ABIKind Kind,
                                bool SoftFloatABI)
       : TargetCodeGenInfo(
-            std::make_unique<PPC64_SVR4_ABIInfo>(CGT, Kind, SoftFloatABI)) {}
+            std::make_unique<PPC64_SVR4_ABIInfo>(CGT, Kind, SoftFloatABI)) {
+    SwiftInfo =
+        std::make_unique<SwiftABIInfo>(CGT, /*SwiftErrorInRegister=*/false);
+  }
 
   int getDwarfEHStackPointer(CodeGen::CodeGenModule &M) const override {
     // This is recovered from gcc output.
     return 1; // r1 is the dedicated stack pointer
   }
 
   bool initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
                                llvm::Value *Address) const override;

 }
 
 //===----------------------------------------------------------------------===//
 // AArch64 ABI Implementation
 //===----------------------------------------------------------------------===//
 
 namespace {
 
-class AArch64ABIInfo : public SwiftABIInfo {
+class AArch64ABIInfo : public ABIInfo {
 public:
   enum ABIKind {
     AAPCS = 0,
     DarwinPCS,
     Win64
   };
 
 private:
   ABIKind Kind;
 
 public:
-  AArch64ABIInfo(CodeGenTypes &CGT, ABIKind Kind)
-    : SwiftABIInfo(CGT), Kind(Kind) {}
+  AArch64ABIInfo(CodeGenTypes &CGT, ABIKind Kind) : ABIInfo(CGT), Kind(Kind) {}
 
 private:
   ABIKind getABIKind() const { return Kind; }
   bool isDarwinPCS() const { return Kind == DarwinPCS; }
 
   ABIArgInfo classifyReturnType(QualType RetTy, bool IsVariadic) const;
   ABIArgInfo classifyArgumentType(QualType RetTy, bool IsVariadic,
                                   unsigned CallingConvention) const;
Address EmitVAArg(CodeGenFunction &CGF, Address VAListAddr,
     return Kind == Win64 ? EmitMSVAArg(CGF, VAListAddr, Ty)
                          : isDarwinPCS() ? EmitDarwinVAArg(VAListAddr, Ty, CGF)
                                          : EmitAAPCSVAArg(VAListAddr, Ty, CGF);
   }
 
   Address EmitMSVAArg(CodeGenFunction &CGF, Address VAListAddr,
                       QualType Ty) const override;
 
-  bool shouldPassIndirectlyForSwift(ArrayRef<llvm::Type*> scalars,
-                                    bool asReturnValue) const override {
-    return occupiesMoreThan(CGT, scalars, /*total*/ 4);
-  }
-  bool isSwiftErrorInRegister() const override {
-    return true;
-  }
-
-  bool isLegalVectorTypeForSwift(CharUnits totalSize, llvm::Type *eltTy,
-                                 unsigned elts) const override;
-
   bool allowBFloatArgsAndRet() const override {
     return getTarget().hasBFloat16Type();
   }
 };
 
+class AArch64SwiftABIInfo : public SwiftABIInfo {
+public:
+  explicit AArch64SwiftABIInfo(CodeGenTypes &CGT)
+      : SwiftABIInfo(CGT, /*SwiftErrorInRegister=*/true) {}
+
+  bool isLegalVectorType(CharUnits VectorSize, llvm::Type *EltTy,
+                         unsigned NumElts) const override;
+};
+
 class AArch64TargetCodeGenInfo : public TargetCodeGenInfo {
 public:
   AArch64TargetCodeGenInfo(CodeGenTypes &CGT, AArch64ABIInfo::ABIKind Kind)
-      : TargetCodeGenInfo(std::make_unique<AArch64ABIInfo>(CGT, Kind)) {}
+      : TargetCodeGenInfo(std::make_unique<AArch64ABIInfo>(CGT, Kind)) {
+    SwiftInfo = std::make_unique<AArch64SwiftABIInfo>(CGT);
+  }
 
   StringRef getARCRetainAutoreleasedReturnValueMarker() const override {
     return "mov\tfp, fp\t\t// marker for objc_retainAutoreleaseReturnValue";
   }
 
   int getDwarfEHStackPointer(CodeGen::CodeGenModule &M) const override {
     return 31;
   }
if (Triple.getArch() == llvm::Triple::aarch64_32 &&
         Triple.isOSBinFormatMachO())
       return Size <= 32;
 
     return Size != 64 && (Size != 128 || NumElements == 1);
   }
   return false;
 }
 
-bool AArch64ABIInfo::isLegalVectorTypeForSwift(CharUnits totalSize,
-                                               llvm::Type *eltTy,
-                                               unsigned elts) const {
-  if (!llvm::isPowerOf2_32(elts))
+bool AArch64SwiftABIInfo::isLegalVectorType(CharUnits VectorSize,
+                                            llvm::Type *EltTy,
+                                            unsigned NumElts) const {
+  if (!llvm::isPowerOf2_32(NumElts))
     return false;
-  if (totalSize.getQuantity() != 8 &&
-      (totalSize.getQuantity() != 16 || elts == 1))
+  if (VectorSize.getQuantity() != 8 &&
+      (VectorSize.getQuantity() != 16 || NumElts == 1))
     return false;
   return true;
 }
 
 bool AArch64ABIInfo::isHomogeneousAggregateBaseType(QualType Ty) const {
   // Homogeneous aggregates for AAPCS64 must have base types of a floating
   // point type or a short-vector type. This is the same as the 32-bit ABI,
   // but with the difference that any floating-point type is allowed,

 }
 
 //===----------------------------------------------------------------------===//
 // ARM ABI Implementation
 //===----------------------------------------------------------------------===//
 
 namespace {
 
-class ARMABIInfo : public SwiftABIInfo {
+class ARMABIInfo : public ABIInfo {
 public:
   enum ABIKind {
     APCS = 0,
     AAPCS = 1,
     AAPCS_VFP = 2,
     AAPCS16_VFP = 3,
   };
 
 private:
   ABIKind Kind;
   bool IsFloatABISoftFP;
 
 public:
-  ARMABIInfo(CodeGenTypes &CGT, ABIKind _Kind)
-      : SwiftABIInfo(CGT), Kind(_Kind) {
+  ARMABIInfo(CodeGenTypes &CGT, ABIKind Kind) : ABIInfo(CGT), Kind(Kind) {
     setCCs();
     IsFloatABISoftFP = CGT.getCodeGenOpts().FloatABI == "softfp" ||
         CGT.getCodeGenOpts().FloatABI == ""; // default
   }
 
   bool isEABI() const {
     switch (getTarget().getTriple().getEnvironment()) {
     case llvm::Triple::Android:
private:
   void computeInfo(CGFunctionInfo &FI) const override;
 
   Address EmitVAArg(CodeGenFunction &CGF, Address VAListAddr,
                     QualType Ty) const override;
 
   llvm::CallingConv::ID getLLVMDefaultCC() const;
   llvm::CallingConv::ID getABIDefaultCC() const;
   void setCCs();
+};
 
-  bool shouldPassIndirectlyForSwift(ArrayRef<llvm::Type*> scalars,
-                                    bool asReturnValue) const override {
-    return occupiesMoreThan(CGT, scalars, /*total*/ 4);
-  }
-  bool isSwiftErrorInRegister() const override {
-    return true;
-  }
-  bool isLegalVectorTypeForSwift(CharUnits totalSize, llvm::Type *eltTy,
-                                 unsigned elts) const override;
+class ARMSwiftABIInfo : public SwiftABIInfo {
+public:
+  explicit ARMSwiftABIInfo(CodeGenTypes &CGT)
+      : SwiftABIInfo(CGT, /*SwiftErrorInRegister=*/true) {}
+
+  bool isLegalVectorType(CharUnits VectorSize, llvm::Type *EltTy,
+                         unsigned NumElts) const override;
 };
 
 class ARMTargetCodeGenInfo : public TargetCodeGenInfo {
 public:
   ARMTargetCodeGenInfo(CodeGenTypes &CGT, ARMABIInfo::ABIKind K)
-      : TargetCodeGenInfo(std::make_unique<ARMABIInfo>(CGT, K)) {}
+      : TargetCodeGenInfo(std::make_unique<ARMABIInfo>(CGT, K)) {
+    SwiftInfo = std::make_unique<ARMSwiftABIInfo>(CGT);
+  }
 
   const ARMABIInfo &getABIInfo() const {
     return static_cast<const ARMABIInfo&>(TargetCodeGenInfo::getABIInfo());
   }
 
   int getDwarfEHStackPointer(CodeGen::CodeGenModule &M) const override {
     return 13;
   }
if (const ConstantArrayType *AT = getContext().getAsConstantArrayType(Ty)) {
     if (const VectorType *VT = Ty->getAs<VectorType>())
       return (VT->getElementType()->isFloat16Type() ||
               VT->getElementType()->isBFloat16Type() ||
               VT->getElementType()->isHalfType());
     return false;
   }
 }
 
-bool ARMABIInfo::isLegalVectorTypeForSwift(CharUnits vectorSize,
-                                           llvm::Type *eltTy,
-                                           unsigned numElts) const {
-  if (!llvm::isPowerOf2_32(numElts))
+bool ARMSwiftABIInfo::isLegalVectorType(CharUnits VectorSize, llvm::Type *EltTy,
+                                        unsigned NumElts) const {
+  if (!llvm::isPowerOf2_32(NumElts))
     return false;
-  unsigned size = getDataLayout().getTypeStoreSizeInBits(eltTy);
+  unsigned size = CGT.getDataLayout().getTypeStoreSizeInBits(EltTy);
   if (size > 64)
     return false;
-  if (vectorSize.getQuantity() != 8 &&
-      (vectorSize.getQuantity() != 16 || numElts == 1))
+  if (VectorSize.getQuantity() != 8 &&
+      (VectorSize.getQuantity() != 16 || NumElts == 1))
     return false;
   return true;
 }
 
 bool ARMABIInfo::isHomogeneousAggregateBaseType(QualType Ty) const {
   // Homogeneous aggregates for AAPCS-VFP must have base types of float,
   // double, or 64-bit or 128-bit vectors.
   if (const BuiltinType *BT = Ty->getAs<BuiltinType>()) {

 }
 
 //===----------------------------------------------------------------------===//
 // SystemZ ABI Implementation
 //===----------------------------------------------------------------------===//
 
 namespace {
 
-class SystemZABIInfo : public SwiftABIInfo {
+class SystemZABIInfo : public ABIInfo {
   bool HasVector;
   bool IsSoftFloatABI;
 
 public:
   SystemZABIInfo(CodeGenTypes &CGT, bool HV, bool SF)
-    : SwiftABIInfo(CGT), HasVector(HV), IsSoftFloatABI(SF) {}
+      : ABIInfo(CGT), HasVector(HV), IsSoftFloatABI(SF) {}
 
   bool isPromotableIntegerTypeForABI(QualType Ty) const;
   bool isCompoundType(QualType Ty) const;
   bool isVectorArgumentType(QualType Ty) const;
   bool isFPArgumentType(QualType Ty) const;
   QualType GetSingleElementType(QualType Ty) const;
 
   ABIArgInfo classifyReturnType(QualType RetTy) const;
   ABIArgInfo classifyArgumentType(QualType ArgTy) const;
 
   void computeInfo(CGFunctionInfo &FI) const override {
     if (!getCXXABI().classifyReturnType(FI))
       FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
     for (auto &I : FI.arguments())
       I.info = classifyArgumentType(I.type);
   }
 
   Address EmitVAArg(CodeGenFunction &CGF, Address VAListAddr,
                     QualType Ty) const override;
-
-  bool shouldPassIndirectlyForSwift(ArrayRef<llvm::Type*> scalars,
-                                    bool asReturnValue) const override {
-    return occupiesMoreThan(CGT, scalars, /*total*/ 4);
-  }
-  bool isSwiftErrorInRegister() const override {
-    return false;
-  }
 };
 
 class SystemZTargetCodeGenInfo : public TargetCodeGenInfo {
 public:
   SystemZTargetCodeGenInfo(CodeGenTypes &CGT, bool HasVector, bool SoftFloatABI)
       : TargetCodeGenInfo(
-            std::make_unique<SystemZABIInfo>(CGT, HasVector, SoftFloatABI)) {}
+            std::make_unique<SystemZABIInfo>(CGT, HasVector, SoftFloatABI)) {
+    SwiftInfo =
+        std::make_unique<SwiftABIInfo>(CGT, /*SwiftErrorInRegister=*/false);
+  }
 
   llvm::Value *testFPKind(llvm::Value *V, unsigned BuiltinID,
                           CGBuilderTy &Builder,
                           CodeGenModule &CGM) const override {
     assert(V->getType()->isFloatingPointTy() && "V should have an FP type.");
     // Only use TDC in constrained FP mode.
     if (!Builder.getIsFPConstrained())
       return nullptr;