//===-- llvm/Target/TargetData.h - Data size & alignment info ---*- C++ -*-===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file defines target 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_TARGET_TARGETDATA_H #define LLVM_TARGET_TARGETDATA_H #include "llvm/Pass.h" #include "llvm/Support/DataTypes.h" #include "llvm/ADT/SmallVector.h" #include <string> namespace llvm { class Value; class Type; class StructType; class StructLayout; class GlobalVariable; /// Enum used to categorize the alignment types stored by TargetAlignElem enum AlignTypeEnum { INTEGER_ALIGN = 'i', ///< Integer type alignment VECTOR_ALIGN = 'v', ///< Vector type alignment FLOAT_ALIGN = 'f', ///< Floating point type alignment AGGREGATE_ALIGN = 'a', ///< Aggregate alignment STACK_ALIGN = 's' ///< Stack objects alignment }; /// Target alignment element. /// /// Stores the alignment data associated with a given alignment type (pointer, /// 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 TargetAlignElem { AlignTypeEnum AlignType : 8; //< Alignment type (AlignTypeEnum) unsigned char ABIAlign; //< ABI alignment for this type/bitw unsigned char PrefAlign; //< Pref. alignment for this type/bitw uint32_t TypeBitWidth; //< Type bit width /// Initializer static TargetAlignElem get(AlignTypeEnum align_type, unsigned char abi_align, unsigned char pref_align, uint32_t bit_width); /// Equality predicate bool operator==(const TargetAlignElem &rhs) const; /// output stream operator std::ostream &dump(std::ostream &os) const; }; class TargetData : public ImmutablePass { private: bool LittleEndian; ///< Defaults to false unsigned char PointerMemSize; ///< Pointer size in bytes unsigned char PointerABIAlign; ///< Pointer ABI alignment unsigned char PointerPrefAlign; ///< Pointer preferred alignment //! Where the primitive type alignment data is stored. /*! @sa init(). @note Could support multiple size pointer alignments, e.g., 32-bit pointers vs. 64-bit pointers by extending TargetAlignment, but for now, we don't. */ SmallVector<TargetAlignElem, 16> Alignments; //! Alignment iterator shorthand typedef SmallVector<TargetAlignElem, 16>::iterator align_iterator; //! Constant alignment iterator shorthand typedef SmallVector<TargetAlignElem, 16>::const_iterator align_const_iterator; //! Invalid alignment. /*! This member is a signal that a requested alignment type and bit width were not found in the SmallVector. */ static const TargetAlignElem InvalidAlignmentElem; //! Set/initialize target alignments void setAlignment(AlignTypeEnum align_type, unsigned char abi_align, unsigned char pref_align, uint32_t bit_width); unsigned getAlignmentInfo(AlignTypeEnum align_type, uint32_t bit_width, bool ABIAlign, const Type *Ty) const; //! Internal helper method that returns requested alignment for type. unsigned char getAlignment(const Type *Ty, bool abi_or_pref) const; /// Valid alignment predicate. /// /// Predicate that tests a TargetAlignElem reference returned by get() against /// InvalidAlignmentElem. inline bool validAlignment(const TargetAlignElem &align) const { return (&align != &InvalidAlignmentElem); } public: /// Default ctor. /// /// @note This has to exist, because this is a pass, but it should never be /// used. TargetData() : ImmutablePass(&ID) { assert(0 && "ERROR: Bad TargetData ctor used. " "Tool did not specify a TargetData to use?"); abort(); } /// Constructs a TargetData from a specification string. See init(). explicit TargetData(const std::string &TargetDescription) : ImmutablePass(&ID) { init(TargetDescription); } /// Initialize target data from properties stored in the module. explicit TargetData(const Module *M); TargetData(const TargetData &TD) : ImmutablePass(&ID), LittleEndian(TD.isLittleEndian()), PointerMemSize(TD.PointerMemSize), PointerABIAlign(TD.PointerABIAlign), PointerPrefAlign(TD.PointerPrefAlign), Alignments(TD.Alignments) { } ~TargetData(); // Not virtual, do not subclass this class //! Parse a target data layout string and initialize TargetData alignments. void init(const std::string &TargetDescription); /// Target endianness... bool isLittleEndian() const { return LittleEndian; } bool isBigEndian() const { return !LittleEndian; } /// getStringRepresentation - Return the string representation of the /// TargetData. This representation is in the same format accepted by the /// string constructor above. std::string getStringRepresentation() const; /// Target pointer alignment unsigned char getPointerABIAlignment() const { return PointerABIAlign; } /// Return target's alignment for stack-based pointers unsigned char getPointerPrefAlignment() const { return PointerPrefAlign; } /// Target pointer size unsigned char getPointerSize() const { return PointerMemSize; } /// Target pointer size, in bits unsigned char getPointerSizeInBits() const { return 8*PointerMemSize; } /// getTypeSizeInBits - Return the number of bits necessary to hold the /// specified type. For example, returns 36 for i36 and 80 for x86_fp80. uint64_t getTypeSizeInBits(const Type* Ty) const; /// getTypeStoreSize - Return the maximum number of bytes that may be /// overwritten by storing the specified type. For example, returns 5 /// for i36 and 10 for x86_fp80. uint64_t getTypeStoreSize(const Type *Ty) const { return (getTypeSizeInBits(Ty)+7)/8; } /// getTypeStoreSizeInBits - Return the maximum number of bits that may be /// overwritten by storing the specified type; always a multiple of 8. For /// example, returns 40 for i36 and 80 for x86_fp80. uint64_t getTypeStoreSizeInBits(const Type *Ty) const { return 8*getTypeStoreSize(Ty); } /// getTypePaddedSize - Return the offset in bytes between successive objects /// of the specified type, including alignment padding. This is the amount /// that alloca reserves for this type. For example, returns 12 or 16 for /// x86_fp80, depending on alignment. uint64_t getTypePaddedSize(const Type* Ty) const { // Round up to the next alignment boundary. return RoundUpAlignment(getTypeStoreSize(Ty), getABITypeAlignment(Ty)); } /// getTypePaddedSizeInBits - Return the offset in bits between successive /// objects of the specified type, including alignment padding; always a /// multiple of 8. This is the amount that alloca reserves for this type. /// For example, returns 96 or 128 for x86_fp80, depending on alignment. uint64_t getTypePaddedSizeInBits(const Type* Ty) const { return 8*getTypePaddedSize(Ty); } /// getABITypeAlignment - Return the minimum ABI-required alignment for the /// specified type. unsigned char getABITypeAlignment(const Type *Ty) const; /// getCallFrameTypeAlignment - Return the minimum ABI-required alignment /// for the specified type when it is part of a call frame. unsigned char getCallFrameTypeAlignment(const Type *Ty) const; /// getPrefTypeAlignment - Return the preferred stack/global alignment for /// the specified type. This is always at least as good as the ABI alignment. unsigned char getPrefTypeAlignment(const Type *Ty) const; /// getPreferredTypeAlignmentShift - Return the preferred alignment for the /// specified type, returned as log2 of the value (a shift amount). /// unsigned char getPreferredTypeAlignmentShift(const Type *Ty) const; /// getIntPtrType - Return an unsigned integer type that is the same size or /// greater to the host pointer size. /// const Type *getIntPtrType() const; /// getIndexedOffset - return the offset from the beginning of the type for /// the specified indices. This is used to implement getelementptr. /// uint64_t getIndexedOffset(const Type *Ty, Value* const* Indices, unsigned NumIndices) const; /// getStructLayout - Return 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(const StructType *Ty) const; /// InvalidateStructLayoutInfo - TargetData speculatively caches StructLayout /// objects. If a TargetData object is alive when types are being refined and /// removed, this method must be called whenever a StructType is removed to /// avoid a dangling pointer in this cache. void InvalidateStructLayoutInfo(const StructType *Ty) const; /// getPreferredAlignment - Return the preferred alignment of the specified /// global. This includes an explicitly requested alignment (if the global /// has one). unsigned getPreferredAlignment(const GlobalVariable *GV) const; /// getPreferredAlignmentLog - Return the preferred alignment of the /// specified global, returned in log form. This includes an explicitly /// requested alignment (if the global has one). unsigned getPreferredAlignmentLog(const GlobalVariable *GV) const; /// RoundUpAlignment - Round the specified value up to the next alignment /// boundary specified by Alignment. For example, 7 rounded up to an /// alignment boundary of 4 is 8. 8 rounded up to the alignment boundary of 4 /// is 8 because it is already aligned. template <typename UIntTy> static UIntTy RoundUpAlignment(UIntTy Val, unsigned Alignment) { assert((Alignment & (Alignment-1)) == 0 && "Alignment must be power of 2!"); return (Val + (Alignment-1)) & ~UIntTy(Alignment-1); } static char ID; // Pass identification, replacement for typeid }; /// StructLayout - used to lazily calculate structure layout information for a /// target machine, based on the TargetData structure. /// class StructLayout { uint64_t StructSize; unsigned StructAlignment; unsigned NumElements; uint64_t MemberOffsets[1]; // variable sized array! public: uint64_t getSizeInBytes() const { return StructSize; } uint64_t getSizeInBits() const { return 8*StructSize; } unsigned getAlignment() const { return StructAlignment; } /// getElementContainingOffset - Given a valid offset into the structure, /// return the structure index that contains it. /// unsigned getElementContainingOffset(uint64_t Offset) const; uint64_t getElementOffset(unsigned Idx) const { assert(Idx < NumElements && "Invalid element idx!"); return MemberOffsets[Idx]; } uint64_t getElementOffsetInBits(unsigned Idx) const { return getElementOffset(Idx)*8; } private: friend class TargetData; // Only TargetData can create this class StructLayout(const StructType *ST, const TargetData &TD); }; } // End llvm namespace #endif