- //===- llvm/DataLayout.h - Data size & alignment info -----------*- C++ -*-===// 
- // 
- // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 
- // See https://llvm.org/LICENSE.txt for license information. 
- // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 
- // 
- //===----------------------------------------------------------------------===// 
- // 
- // This file defines layout properties related to datatype size/offset/alignment 
- // information.  It uses lazy annotations to cache information about how 
- // structure types are laid out and used. 
- // 
- // This structure should be created once, filled in if the defaults are not 
- // correct and then passed around by const&.  None of the members functions 
- // require modification to the object. 
- // 
- //===----------------------------------------------------------------------===// 
-   
- #ifndef LLVM_IR_DATALAYOUT_H 
- #define LLVM_IR_DATALAYOUT_H 
-   
- #include "llvm/ADT/APInt.h" 
- #include "llvm/ADT/ArrayRef.h" 
- #include "llvm/ADT/STLExtras.h" 
- #include "llvm/ADT/SmallVector.h" 
- #include "llvm/ADT/StringRef.h" 
- #include "llvm/IR/DerivedTypes.h" 
- #include "llvm/IR/Type.h" 
- #include "llvm/Support/Alignment.h" 
- #include "llvm/Support/Casting.h" 
- #include "llvm/Support/Compiler.h" 
- #include "llvm/Support/ErrorHandling.h" 
- #include "llvm/Support/MathExtras.h" 
- #include "llvm/Support/TrailingObjects.h" 
- #include "llvm/Support/TypeSize.h" 
- #include <cassert> 
- #include <cstdint> 
- #include <string> 
-   
- // This needs to be outside of the namespace, to avoid conflict with llvm-c 
- // decl. 
- using LLVMTargetDataRef = struct LLVMOpaqueTargetData *; 
-   
- namespace llvm { 
-   
- class GlobalVariable; 
- class LLVMContext; 
- class Module; 
- class StructLayout; 
- class Triple; 
- class Value; 
-   
- /// Enum used to categorize the alignment types stored by LayoutAlignElem 
- enum AlignTypeEnum { 
-   INVALID_ALIGN = 0, 
-   INTEGER_ALIGN = 'i', 
-   VECTOR_ALIGN = 'v', 
-   FLOAT_ALIGN = 'f', 
-   AGGREGATE_ALIGN = 'a' 
- }; 
-   
- // FIXME: Currently the DataLayout string carries a "preferred alignment" 
- // for types. As the DataLayout is module/global, this should likely be 
- // sunk down to an FTTI element that is queried rather than a global 
- // preference. 
-   
- /// Layout alignment element. 
- /// 
- /// Stores the alignment data associated with a given alignment type (integer, 
- /// vector, float) and type bit width. 
- /// 
- /// \note The unusual order of elements in the structure attempts to reduce 
- /// padding and make the structure slightly more cache friendly. 
- struct LayoutAlignElem { 
-   /// Alignment type from \c AlignTypeEnum 
-   unsigned AlignType : 8; 
-   unsigned TypeBitWidth : 24; 
-   Align ABIAlign; 
-   Align PrefAlign; 
-   
-   static LayoutAlignElem get(AlignTypeEnum align_type, Align abi_align, 
-                              Align pref_align, uint32_t bit_width); 
-   
-   bool operator==(const LayoutAlignElem &rhs) const; 
- }; 
-   
- /// Layout pointer alignment element. 
- /// 
- /// Stores the alignment data associated with a given pointer and address space. 
- /// 
- /// \note The unusual order of elements in the structure attempts to reduce 
- /// padding and make the structure slightly more cache friendly. 
- struct PointerAlignElem { 
-   Align ABIAlign; 
-   Align PrefAlign; 
-   uint32_t TypeBitWidth; 
-   uint32_t AddressSpace; 
-   uint32_t IndexBitWidth; 
-   
-   /// Initializer 
-   static PointerAlignElem getInBits(uint32_t AddressSpace, Align ABIAlign, 
-                                     Align PrefAlign, uint32_t TypeBitWidth, 
-                                     uint32_t IndexBitWidth); 
-   
-   bool operator==(const PointerAlignElem &rhs) const; 
- }; 
-   
- /// A parsed version of the target data layout string in and methods for 
- /// querying it. 
- /// 
- /// The target data layout string is specified *by the target* - a frontend 
- /// generating LLVM IR is required to generate the right target data for the 
- /// target being codegen'd to. 
- class DataLayout { 
- public: 
-   enum class FunctionPtrAlignType { 
-     /// The function pointer alignment is independent of the function alignment. 
-     Independent, 
-     /// The function pointer alignment is a multiple of the function alignment. 
-     MultipleOfFunctionAlign, 
-   }; 
- private: 
-   /// Defaults to false. 
-   bool BigEndian; 
-   
-   unsigned AllocaAddrSpace; 
-   MaybeAlign StackNaturalAlign; 
-   unsigned ProgramAddrSpace; 
-   unsigned DefaultGlobalsAddrSpace; 
-   
-   MaybeAlign FunctionPtrAlign; 
-   FunctionPtrAlignType TheFunctionPtrAlignType; 
-   
-   enum ManglingModeT { 
-     MM_None, 
-     MM_ELF, 
-     MM_MachO, 
-     MM_WinCOFF, 
-     MM_WinCOFFX86, 
-     MM_GOFF, 
-     MM_Mips, 
-     MM_XCOFF 
-   }; 
-   ManglingModeT ManglingMode; 
-   
-   SmallVector<unsigned char, 8> LegalIntWidths; 
-   
-   /// Primitive type alignment data. This is sorted by type and bit 
-   /// width during construction. 
-   using AlignmentsTy = SmallVector<LayoutAlignElem, 16>; 
-   AlignmentsTy Alignments; 
-   
-   AlignmentsTy::const_iterator 
-   findAlignmentLowerBound(AlignTypeEnum AlignType, uint32_t BitWidth) const { 
-     return const_cast<DataLayout *>(this)->findAlignmentLowerBound(AlignType, 
-                                                                    BitWidth); 
-   } 
-   
-   AlignmentsTy::iterator 
-   findAlignmentLowerBound(AlignTypeEnum AlignType, uint32_t BitWidth); 
-   
-   /// The string representation used to create this DataLayout 
-   std::string StringRepresentation; 
-   
-   using PointersTy = SmallVector<PointerAlignElem, 8>; 
-   PointersTy Pointers; 
-   
-   const PointerAlignElem &getPointerAlignElem(uint32_t AddressSpace) const; 
-   
-   // The StructType -> StructLayout map. 
-   mutable void *LayoutMap = nullptr; 
-   
-   /// Pointers in these address spaces are non-integral, and don't have a 
-   /// well-defined bitwise representation. 
-   SmallVector<unsigned, 8> NonIntegralAddressSpaces; 
-   
-   /// Attempts to set the alignment of the given type. Returns an error 
-   /// description on failure. 
-   Error setAlignment(AlignTypeEnum align_type, Align abi_align, 
-                      Align pref_align, uint32_t bit_width); 
-   
-   /// Attempts to set the alignment of a pointer in the given address space. 
-   /// Returns an error description on failure. 
-   Error setPointerAlignmentInBits(uint32_t AddrSpace, Align ABIAlign, 
-                                   Align PrefAlign, uint32_t TypeBitWidth, 
-                                   uint32_t IndexBitWidth); 
-   
-   /// Internal helper to get alignment for integer of given bitwidth. 
-   Align getIntegerAlignment(uint32_t BitWidth, bool abi_or_pref) const; 
-   
-   /// Internal helper method that returns requested alignment for type. 
-   Align getAlignment(Type *Ty, bool abi_or_pref) const; 
-   
-   /// Attempts to parse a target data specification string and reports an error 
-   /// if the string is malformed. 
-   Error parseSpecifier(StringRef Desc); 
-   
-   // Free all internal data structures. 
-   void clear(); 
-   
- public: 
-   /// Constructs a DataLayout from a specification string. See reset(). 
-   explicit DataLayout(StringRef LayoutDescription) { 
-     reset(LayoutDescription); 
-   } 
-   
-   /// Initialize target data from properties stored in the module. 
-   explicit DataLayout(const Module *M); 
-   
-   DataLayout(const DataLayout &DL) { *this = DL; } 
-   
-   ~DataLayout(); // Not virtual, do not subclass this class 
-   
-   DataLayout &operator=(const DataLayout &DL) { 
-     clear(); 
-     StringRepresentation = DL.StringRepresentation; 
-     BigEndian = DL.isBigEndian(); 
-     AllocaAddrSpace = DL.AllocaAddrSpace; 
-     StackNaturalAlign = DL.StackNaturalAlign; 
-     FunctionPtrAlign = DL.FunctionPtrAlign; 
-     TheFunctionPtrAlignType = DL.TheFunctionPtrAlignType; 
-     ProgramAddrSpace = DL.ProgramAddrSpace; 
-     DefaultGlobalsAddrSpace = DL.DefaultGlobalsAddrSpace; 
-     ManglingMode = DL.ManglingMode; 
-     LegalIntWidths = DL.LegalIntWidths; 
-     Alignments = DL.Alignments; 
-     Pointers = DL.Pointers; 
-     NonIntegralAddressSpaces = DL.NonIntegralAddressSpaces; 
-     return *this; 
-   } 
-   
-   bool operator==(const DataLayout &Other) const; 
-   bool operator!=(const DataLayout &Other) const { return !(*this == Other); } 
-   
-   void init(const Module *M); 
-   
-   /// Parse a data layout string (with fallback to default values). 
-   void reset(StringRef LayoutDescription); 
-   
-   /// Parse a data layout string and return the layout. Return an error 
-   /// description on failure. 
-   static Expected<DataLayout> parse(StringRef LayoutDescription); 
-   
-   /// Layout endianness... 
-   bool isLittleEndian() const { return !BigEndian; } 
-   bool isBigEndian() const { return BigEndian; } 
-   
-   /// Returns the string representation of the DataLayout. 
-   /// 
-   /// This representation is in the same format accepted by the string 
-   /// constructor above. This should not be used to compare two DataLayout as 
-   /// different string can represent the same layout. 
-   const std::string &getStringRepresentation() const { 
-     return StringRepresentation; 
-   } 
-   
-   /// Test if the DataLayout was constructed from an empty string. 
-   bool isDefault() const { return StringRepresentation.empty(); } 
-   
-   /// Returns true if the specified type is known to be a native integer 
-   /// type supported by the CPU. 
-   /// 
-   /// For example, i64 is not native on most 32-bit CPUs and i37 is not native 
-   /// on any known one. This returns false if the integer width is not legal. 
-   /// 
-   /// The width is specified in bits. 
-   bool isLegalInteger(uint64_t Width) const { 
-     return llvm::is_contained(LegalIntWidths, Width); 
-   } 
-   
-   bool isIllegalInteger(uint64_t Width) const { return !isLegalInteger(Width); } 
-   
-   /// Returns true if the given alignment exceeds the natural stack alignment. 
-   bool exceedsNaturalStackAlignment(Align Alignment) const { 
-     return StackNaturalAlign && (Alignment > *StackNaturalAlign); 
-   } 
-   
-   Align getStackAlignment() const { 
-     assert(StackNaturalAlign && "StackNaturalAlign must be defined"); 
-     return *StackNaturalAlign; 
-   } 
-   
-   unsigned getAllocaAddrSpace() const { return AllocaAddrSpace; } 
-   
-   /// Returns the alignment of function pointers, which may or may not be 
-   /// related to the alignment of functions. 
-   /// \see getFunctionPtrAlignType 
-   MaybeAlign getFunctionPtrAlign() const { return FunctionPtrAlign; } 
-   
-   /// Return the type of function pointer alignment. 
-   /// \see getFunctionPtrAlign 
-   FunctionPtrAlignType getFunctionPtrAlignType() const { 
-     return TheFunctionPtrAlignType; 
-   } 
-   
-   unsigned getProgramAddressSpace() const { return ProgramAddrSpace; } 
-   unsigned getDefaultGlobalsAddressSpace() const { 
-     return DefaultGlobalsAddrSpace; 
-   } 
-   
-   bool hasMicrosoftFastStdCallMangling() const { 
-     return ManglingMode == MM_WinCOFFX86; 
-   } 
-   
-   /// Returns true if symbols with leading question marks should not receive IR 
-   /// mangling. True for Windows mangling modes. 
-   bool doNotMangleLeadingQuestionMark() const { 
-     return ManglingMode == MM_WinCOFF || ManglingMode == MM_WinCOFFX86; 
-   } 
-   
-   bool hasLinkerPrivateGlobalPrefix() const { return ManglingMode == MM_MachO; } 
-   
-   StringRef getLinkerPrivateGlobalPrefix() const { 
-     if (ManglingMode == MM_MachO) 
-       return "l"; 
-     return ""; 
-   } 
-   
-   char getGlobalPrefix() const { 
-     switch (ManglingMode) { 
-     case MM_None: 
-     case MM_ELF: 
-     case MM_GOFF: 
-     case MM_Mips: 
-     case MM_WinCOFF: 
-     case MM_XCOFF: 
-       return '\0'; 
-     case MM_MachO: 
-     case MM_WinCOFFX86: 
-       return '_'; 
-     } 
-     llvm_unreachable("invalid mangling mode"); 
-   } 
-   
-   StringRef getPrivateGlobalPrefix() const { 
-     switch (ManglingMode) { 
-     case MM_None: 
-       return ""; 
-     case MM_ELF: 
-     case MM_WinCOFF: 
-       return ".L"; 
-     case MM_GOFF: 
-       return "@"; 
-     case MM_Mips: 
-       return "$"; 
-     case MM_MachO: 
-     case MM_WinCOFFX86: 
-       return "L"; 
-     case MM_XCOFF: 
-       return "L.."; 
-     } 
-     llvm_unreachable("invalid mangling mode"); 
-   } 
-   
-   static const char *getManglingComponent(const Triple &T); 
-   
-   /// Returns true if the specified type fits in a native integer type 
-   /// supported by the CPU. 
-   /// 
-   /// For example, if the CPU only supports i32 as a native integer type, then 
-   /// i27 fits in a legal integer type but i45 does not. 
-   bool fitsInLegalInteger(unsigned Width) const { 
-     for (unsigned LegalIntWidth : LegalIntWidths) 
-       if (Width <= LegalIntWidth) 
-         return true; 
-     return false; 
-   } 
-   
-   /// Layout pointer alignment 
-   Align getPointerABIAlignment(unsigned AS) const; 
-   
-   /// Return target's alignment for stack-based pointers 
-   /// FIXME: The defaults need to be removed once all of 
-   /// the backends/clients are updated. 
-   Align getPointerPrefAlignment(unsigned AS = 0) const; 
-   
-   /// Layout pointer size in bytes, rounded up to a whole 
-   /// number of bytes. 
-   /// FIXME: The defaults need to be removed once all of 
-   /// the backends/clients are updated. 
-   unsigned getPointerSize(unsigned AS = 0) const; 
-   
-   /// Returns the maximum index size over all address spaces. 
-   unsigned getMaxIndexSize() const; 
-   
-   // Index size in bytes used for address calculation, 
-   /// rounded up to a whole number of bytes. 
-   unsigned getIndexSize(unsigned AS) const; 
-   
-   /// Return the address spaces containing non-integral pointers.  Pointers in 
-   /// this address space don't have a well-defined bitwise representation. 
-   ArrayRef<unsigned> getNonIntegralAddressSpaces() const { 
-     return NonIntegralAddressSpaces; 
-   } 
-   
-   bool isNonIntegralAddressSpace(unsigned AddrSpace) const { 
-     ArrayRef<unsigned> NonIntegralSpaces = getNonIntegralAddressSpaces(); 
-     return is_contained(NonIntegralSpaces, AddrSpace); 
-   } 
-   
-   bool isNonIntegralPointerType(PointerType *PT) const { 
-     return isNonIntegralAddressSpace(PT->getAddressSpace()); 
-   } 
-   
-   bool isNonIntegralPointerType(Type *Ty) const { 
-     auto *PTy = dyn_cast<PointerType>(Ty); 
-     return PTy && isNonIntegralPointerType(PTy); 
-   } 
-   
-   /// Layout pointer size, in bits 
-   /// FIXME: The defaults need to be removed once all of 
-   /// the backends/clients are updated. 
-   unsigned getPointerSizeInBits(unsigned AS = 0) const { 
-     return getPointerAlignElem(AS).TypeBitWidth; 
-   } 
-   
-   /// Returns the maximum index size over all address spaces. 
-   unsigned getMaxIndexSizeInBits() const { 
-     return getMaxIndexSize() * 8; 
-   } 
-   
-   /// Size in bits of index used for address calculation in getelementptr. 
-   unsigned getIndexSizeInBits(unsigned AS) const { 
-     return getPointerAlignElem(AS).IndexBitWidth; 
-   } 
-   
-   /// Layout pointer size, in bits, based on the type.  If this function is 
-   /// called with a pointer type, then the type size of the pointer is returned. 
-   /// If this function is called with a vector of pointers, then the type size 
-   /// of the pointer is returned.  This should only be called with a pointer or 
-   /// vector of pointers. 
-   unsigned getPointerTypeSizeInBits(Type *) const; 
-   
-   /// Layout size of the index used in GEP calculation. 
-   /// The function should be called with pointer or vector of pointers type. 
-   unsigned getIndexTypeSizeInBits(Type *Ty) const; 
-   
-   unsigned getPointerTypeSize(Type *Ty) const { 
-     return getPointerTypeSizeInBits(Ty) / 8; 
-   } 
-   
-   /// Size examples: 
-   /// 
-   /// Type        SizeInBits  StoreSizeInBits  AllocSizeInBits[*] 
-   /// ----        ----------  ---------------  --------------- 
-   ///  i1            1           8                8 
-   ///  i8            8           8                8 
-   ///  i19          19          24               32 
-   ///  i32          32          32               32 
-   ///  i100        100         104              128 
-   ///  i128        128         128              128 
-   ///  Float        32          32               32 
-   ///  Double       64          64               64 
-   ///  X86_FP80     80          80               96 
-   /// 
-   /// [*] The alloc size depends on the alignment, and thus on the target. 
-   ///     These values are for x86-32 linux. 
-   
-   /// Returns the number of bits necessary to hold the specified type. 
-   /// 
-   /// If Ty is a scalable vector type, the scalable property will be set and 
-   /// the runtime size will be a positive integer multiple of the base size. 
-   /// 
-   /// For example, returns 36 for i36 and 80 for x86_fp80. The type passed must 
-   /// have a size (Type::isSized() must return true). 
-   TypeSize getTypeSizeInBits(Type *Ty) const; 
-   
-   /// Returns the maximum number of bytes that may be overwritten by 
-   /// storing the specified type. 
-   /// 
-   /// If Ty is a scalable vector type, the scalable property will be set and 
-   /// the runtime size will be a positive integer multiple of the base size. 
-   /// 
-   /// For example, returns 5 for i36 and 10 for x86_fp80. 
-   TypeSize getTypeStoreSize(Type *Ty) const { 
-     TypeSize BaseSize = getTypeSizeInBits(Ty); 
-     return {divideCeil(BaseSize.getKnownMinValue(), 8), BaseSize.isScalable()}; 
-   } 
-   
-   /// Returns the maximum number of bits that may be overwritten by 
-   /// storing the specified type; always a multiple of 8. 
-   /// 
-   /// If Ty is a scalable vector type, the scalable property will be set and 
-   /// the runtime size will be a positive integer multiple of the base size. 
-   /// 
-   /// For example, returns 40 for i36 and 80 for x86_fp80. 
-   TypeSize getTypeStoreSizeInBits(Type *Ty) const { 
-     return 8 * getTypeStoreSize(Ty); 
-   } 
-   
-   /// Returns true if no extra padding bits are needed when storing the 
-   /// specified type. 
-   /// 
-   /// For example, returns false for i19 that has a 24-bit store size. 
-   bool typeSizeEqualsStoreSize(Type *Ty) const { 
-     return getTypeSizeInBits(Ty) == getTypeStoreSizeInBits(Ty); 
-   } 
-   
-   /// Returns the offset in bytes between successive objects of the 
-   /// specified type, including alignment padding. 
-   /// 
-   /// If Ty is a scalable vector type, the scalable property will be set and 
-   /// the runtime size will be a positive integer multiple of the base size. 
-   /// 
-   /// This is the amount that alloca reserves for this type. For example, 
-   /// returns 12 or 16 for x86_fp80, depending on alignment. 
-   TypeSize getTypeAllocSize(Type *Ty) const { 
-     // Round up to the next alignment boundary. 
-     return alignTo(getTypeStoreSize(Ty), getABITypeAlign(Ty).value()); 
-   } 
-   
-   /// Returns the offset in bits between successive objects of the 
-   /// specified type, including alignment padding; always a multiple of 8. 
-   /// 
-   /// If Ty is a scalable vector type, the scalable property will be set and 
-   /// the runtime size will be a positive integer multiple of the base size. 
-   /// 
-   /// This is the amount that alloca reserves for this type. For example, 
-   /// returns 96 or 128 for x86_fp80, depending on alignment. 
-   TypeSize getTypeAllocSizeInBits(Type *Ty) const { 
-     return 8 * getTypeAllocSize(Ty); 
-   } 
-   
-   /// Returns the minimum ABI-required alignment for the specified type. 
-   /// FIXME: Deprecate this function once migration to Align is over. 
-   LLVM_DEPRECATED("use getABITypeAlign instead", "getABITypeAlign") 
-   uint64_t getABITypeAlignment(Type *Ty) const; 
-   
-   /// Returns the minimum ABI-required alignment for the specified type. 
-   Align getABITypeAlign(Type *Ty) const; 
-   
-   /// Helper function to return `Alignment` if it's set or the result of 
-   /// `getABITypeAlignment(Ty)`, in any case the result is a valid alignment. 
-   inline Align getValueOrABITypeAlignment(MaybeAlign Alignment, 
-                                           Type *Ty) const { 
-     return Alignment ? *Alignment : getABITypeAlign(Ty); 
-   } 
-   
-   /// Returns the minimum ABI-required alignment for an integer type of 
-   /// the specified bitwidth. 
-   Align getABIIntegerTypeAlignment(unsigned BitWidth) const { 
-     return getIntegerAlignment(BitWidth, /* abi_or_pref */ true); 
-   } 
-   
-   /// Returns the preferred stack/global alignment for the specified 
-   /// type. 
-   /// 
-   /// This is always at least as good as the ABI alignment. 
-   /// FIXME: Deprecate this function once migration to Align is over. 
-   LLVM_DEPRECATED("use getPrefTypeAlign instead", "getPrefTypeAlign") 
-   uint64_t getPrefTypeAlignment(Type *Ty) const; 
-   
-   /// Returns the preferred stack/global alignment for the specified 
-   /// type. 
-   /// 
-   /// This is always at least as good as the ABI alignment. 
-   Align getPrefTypeAlign(Type *Ty) const; 
-   
-   /// Returns an integer type with size at least as big as that of a 
-   /// pointer in the given address space. 
-   IntegerType *getIntPtrType(LLVMContext &C, unsigned AddressSpace = 0) const; 
-   
-   /// Returns an integer (vector of integer) type with size at least as 
-   /// big as that of a pointer of the given pointer (vector of pointer) type. 
-   Type *getIntPtrType(Type *) const; 
-   
-   /// Returns the smallest integer type with size at least as big as 
-   /// Width bits. 
-   Type *getSmallestLegalIntType(LLVMContext &C, unsigned Width = 0) const; 
-   
-   /// Returns the largest legal integer type, or null if none are set. 
-   Type *getLargestLegalIntType(LLVMContext &C) const { 
-     unsigned LargestSize = getLargestLegalIntTypeSizeInBits(); 
-     return (LargestSize == 0) ? nullptr : Type::getIntNTy(C, LargestSize); 
-   } 
-   
-   /// Returns the size of largest legal integer type size, or 0 if none 
-   /// are set. 
-   unsigned getLargestLegalIntTypeSizeInBits() const; 
-   
-   /// Returns the type of a GEP index. 
-   /// If it was not specified explicitly, it will be the integer type of the 
-   /// pointer width - IntPtrType. 
-   Type *getIndexType(Type *PtrTy) const; 
-   
-   /// Returns the offset from the beginning of the type for the specified 
-   /// indices. 
-   /// 
-   /// Note that this takes the element type, not the pointer type. 
-   /// This is used to implement getelementptr. 
-   int64_t getIndexedOffsetInType(Type *ElemTy, ArrayRef<Value *> Indices) const; 
-   
-   /// Get GEP indices to access Offset inside ElemTy. ElemTy is updated to be 
-   /// the result element type and Offset to be the residual offset. 
-   SmallVector<APInt> getGEPIndicesForOffset(Type *&ElemTy, APInt &Offset) const; 
-   
-   /// Get single GEP index to access Offset inside ElemTy. Returns std::nullopt 
-   /// if index cannot be computed, e.g. because the type is not an aggregate. 
-   /// ElemTy is updated to be the result element type and Offset to be the 
-   /// residual offset. 
-   std::optional<APInt> getGEPIndexForOffset(Type *&ElemTy, APInt &Offset) const; 
-   
-   /// Returns a StructLayout object, indicating the alignment of the 
-   /// struct, its size, and the offsets of its fields. 
-   /// 
-   /// Note that this information is lazily cached. 
-   const StructLayout *getStructLayout(StructType *Ty) const; 
-   
-   /// Returns the preferred alignment of the specified global. 
-   /// 
-   /// This includes an explicitly requested alignment (if the global has one). 
-   Align getPreferredAlign(const GlobalVariable *GV) const; 
- }; 
-   
- inline DataLayout *unwrap(LLVMTargetDataRef P) { 
-   return reinterpret_cast<DataLayout *>(P); 
- } 
-   
- inline LLVMTargetDataRef wrap(const DataLayout *P) { 
-   return reinterpret_cast<LLVMTargetDataRef>(const_cast<DataLayout *>(P)); 
- } 
-   
- /// Used to lazily calculate structure layout information for a target machine, 
- /// based on the DataLayout structure. 
- class StructLayout final : public TrailingObjects<StructLayout, uint64_t> { 
-   uint64_t StructSize; 
-   Align StructAlignment; 
-   unsigned IsPadded : 1; 
-   unsigned NumElements : 31; 
-   
- public: 
-   uint64_t getSizeInBytes() const { return StructSize; } 
-   
-   uint64_t getSizeInBits() const { return 8 * StructSize; } 
-   
-   Align getAlignment() const { return StructAlignment; } 
-   
-   /// Returns whether the struct has padding or not between its fields. 
-   /// NB: Padding in nested element is not taken into account. 
-   bool hasPadding() const { return IsPadded; } 
-   
-   /// Given a valid byte offset into the structure, returns the structure 
-   /// index that contains it. 
-   unsigned getElementContainingOffset(uint64_t Offset) const; 
-   
-   MutableArrayRef<uint64_t> getMemberOffsets() { 
-     return llvm::MutableArrayRef(getTrailingObjects<uint64_t>(), 
-                                      NumElements); 
-   } 
-   
-   ArrayRef<uint64_t> getMemberOffsets() const { 
-     return llvm::ArrayRef(getTrailingObjects<uint64_t>(), NumElements); 
-   } 
-   
-   uint64_t getElementOffset(unsigned Idx) const { 
-     assert(Idx < NumElements && "Invalid element idx!"); 
-     return getMemberOffsets()[Idx]; 
-   } 
-   
-   uint64_t getElementOffsetInBits(unsigned Idx) const { 
-     return getElementOffset(Idx) * 8; 
-   } 
-   
- private: 
-   friend class DataLayout; // Only DataLayout can create this class 
-   
-   StructLayout(StructType *ST, const DataLayout &DL); 
-   
-   size_t numTrailingObjects(OverloadToken<uint64_t>) const { 
-     return NumElements; 
-   } 
- }; 
-   
- // The implementation of this method is provided inline as it is particularly 
- // well suited to constant folding when called on a specific Type subclass. 
- inline TypeSize DataLayout::getTypeSizeInBits(Type *Ty) const { 
-   assert(Ty->isSized() && "Cannot getTypeInfo() on a type that is unsized!"); 
-   switch (Ty->getTypeID()) { 
-   case Type::LabelTyID: 
-     return TypeSize::Fixed(getPointerSizeInBits(0)); 
-   case Type::PointerTyID: 
-     return TypeSize::Fixed(getPointerSizeInBits(Ty->getPointerAddressSpace())); 
-   case Type::ArrayTyID: { 
-     ArrayType *ATy = cast<ArrayType>(Ty); 
-     return ATy->getNumElements() * 
-            getTypeAllocSizeInBits(ATy->getElementType()); 
-   } 
-   case Type::StructTyID: 
-     // Get the layout annotation... which is lazily created on demand. 
-     return TypeSize::Fixed( 
-                         getStructLayout(cast<StructType>(Ty))->getSizeInBits()); 
-   case Type::IntegerTyID: 
-     return TypeSize::Fixed(Ty->getIntegerBitWidth()); 
-   case Type::HalfTyID: 
-   case Type::BFloatTyID: 
-     return TypeSize::Fixed(16); 
-   case Type::FloatTyID: 
-     return TypeSize::Fixed(32); 
-   case Type::DoubleTyID: 
-   case Type::X86_MMXTyID: 
-     return TypeSize::Fixed(64); 
-   case Type::PPC_FP128TyID: 
-   case Type::FP128TyID: 
-     return TypeSize::Fixed(128); 
-   case Type::X86_AMXTyID: 
-     return TypeSize::Fixed(8192); 
-   // In memory objects this is always aligned to a higher boundary, but 
-   // only 80 bits contain information. 
-   case Type::X86_FP80TyID: 
-     return TypeSize::Fixed(80); 
-   case Type::FixedVectorTyID: 
-   case Type::ScalableVectorTyID: { 
-     VectorType *VTy = cast<VectorType>(Ty); 
-     auto EltCnt = VTy->getElementCount(); 
-     uint64_t MinBits = EltCnt.getKnownMinValue() * 
-                        getTypeSizeInBits(VTy->getElementType()).getFixedValue(); 
-     return TypeSize(MinBits, EltCnt.isScalable()); 
-   } 
-   case Type::TargetExtTyID: { 
-     Type *LayoutTy = cast<TargetExtType>(Ty)->getLayoutType(); 
-     return getTypeSizeInBits(LayoutTy); 
-   } 
-   default: 
-     llvm_unreachable("DataLayout::getTypeSizeInBits(): Unsupported type"); 
-   } 
- } 
-   
- } // end namespace llvm 
-   
- #endif // LLVM_IR_DATALAYOUT_H 
-