|  | //===-- TargetData.cpp - Data size & alignment routines --------------------==// | 
|  | // | 
|  | //                     The LLVM Compiler Infrastructure | 
|  | // | 
|  | // This file was developed by the LLVM research group and 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. | 
|  | // | 
|  | // 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. | 
|  | // | 
|  | //===----------------------------------------------------------------------===// | 
|  |  | 
|  | #include "llvm/Target/TargetData.h" | 
|  | #include "llvm/Module.h" | 
|  | #include "llvm/DerivedTypes.h" | 
|  | #include "llvm/Constants.h" | 
|  | #include "llvm/Support/GetElementPtrTypeIterator.h" | 
|  | #include "llvm/Support/MathExtras.h" | 
|  | #include <algorithm> | 
|  | using namespace llvm; | 
|  |  | 
|  | // Handle the Pass registration stuff necessary to use TargetData's. | 
|  | namespace { | 
|  | // Register the default SparcV9 implementation... | 
|  | RegisterPass<TargetData> X("targetdata", "Target Data Layout"); | 
|  | } | 
|  |  | 
|  | static inline void getTypeInfo(const Type *Ty, const TargetData *TD, | 
|  | uint64_t &Size, unsigned char &Alignment); | 
|  |  | 
|  | //===----------------------------------------------------------------------===// | 
|  | // Support for StructLayout | 
|  | //===----------------------------------------------------------------------===// | 
|  |  | 
|  | StructLayout::StructLayout(const StructType *ST, const TargetData &TD) { | 
|  | StructAlignment = 0; | 
|  | StructSize = 0; | 
|  |  | 
|  | // Loop over each of the elements, placing them in memory... | 
|  | for (StructType::element_iterator TI = ST->element_begin(), | 
|  | TE = ST->element_end(); TI != TE; ++TI) { | 
|  | const Type *Ty = *TI; | 
|  | unsigned char A; | 
|  | unsigned TyAlign; | 
|  | uint64_t TySize; | 
|  | getTypeInfo(Ty, &TD, TySize, A); | 
|  | TyAlign = A; | 
|  |  | 
|  | // Add padding if necessary to make the data element aligned properly... | 
|  | if (StructSize % TyAlign != 0) | 
|  | StructSize = (StructSize/TyAlign + 1) * TyAlign;   // Add padding... | 
|  |  | 
|  | // Keep track of maximum alignment constraint | 
|  | StructAlignment = std::max(TyAlign, StructAlignment); | 
|  |  | 
|  | MemberOffsets.push_back(StructSize); | 
|  | StructSize += TySize;                 // Consume space for this data item | 
|  | } | 
|  |  | 
|  | // Empty structures have alignment of 1 byte. | 
|  | if (StructAlignment == 0) StructAlignment = 1; | 
|  |  | 
|  | // Add padding to the end of the struct so that it could be put in an array | 
|  | // and all array elements would be aligned correctly. | 
|  | if (StructSize % StructAlignment != 0) | 
|  | StructSize = (StructSize/StructAlignment + 1) * StructAlignment; | 
|  | } | 
|  |  | 
|  |  | 
|  | /// getElementContainingOffset - Given a valid offset into the structure, | 
|  | /// return the structure index that contains it. | 
|  | unsigned StructLayout::getElementContainingOffset(uint64_t Offset) const { | 
|  | std::vector<uint64_t>::const_iterator SI = | 
|  | std::upper_bound(MemberOffsets.begin(), MemberOffsets.end(), | 
|  | Offset); | 
|  | assert(SI != MemberOffsets.begin() && "Offset not in structure type!"); | 
|  | --SI; | 
|  | assert(*SI <= Offset && "upper_bound didn't work"); | 
|  | assert((SI == MemberOffsets.begin() || *(SI-1) < Offset) && | 
|  | (SI+1 == MemberOffsets.end() || *(SI+1) > Offset) && | 
|  | "Upper bound didn't work!"); | 
|  | return SI-MemberOffsets.begin(); | 
|  | } | 
|  |  | 
|  | //===----------------------------------------------------------------------===// | 
|  | //                       TargetData Class Implementation | 
|  | //===----------------------------------------------------------------------===// | 
|  |  | 
|  | TargetData::TargetData(const std::string &TargetName, | 
|  | bool isLittleEndian, unsigned char PtrSize, | 
|  | unsigned char PtrAl, unsigned char DoubleAl, | 
|  | unsigned char FloatAl, unsigned char LongAl, | 
|  | unsigned char IntAl, unsigned char ShortAl, | 
|  | unsigned char ByteAl, unsigned char BoolAl) { | 
|  |  | 
|  | // If this assert triggers, a pass "required" TargetData information, but the | 
|  | // top level tool did not provide one for it.  We do not want to default | 
|  | // construct, or else we might end up using a bad endianness or pointer size! | 
|  | // | 
|  | assert(!TargetName.empty() && | 
|  | "ERROR: Tool did not specify a target data to use!"); | 
|  |  | 
|  | LittleEndian     = isLittleEndian; | 
|  | PointerSize      = PtrSize; | 
|  | PointerAlignment = PtrAl; | 
|  | DoubleAlignment  = DoubleAl; | 
|  | FloatAlignment   = FloatAl; | 
|  | LongAlignment    = LongAl; | 
|  | IntAlignment     = IntAl; | 
|  | ShortAlignment   = ShortAl; | 
|  | ByteAlignment    = ByteAl; | 
|  | BoolAlignment    = BoolAl; | 
|  | } | 
|  |  | 
|  | TargetData::TargetData(const std::string &ToolName, const Module *M) { | 
|  | LittleEndian     = M->getEndianness() != Module::BigEndian; | 
|  | PointerSize      = M->getPointerSize() != Module::Pointer64 ? 4 : 8; | 
|  | PointerAlignment = PointerSize; | 
|  | DoubleAlignment  = PointerSize; | 
|  | FloatAlignment   = 4; | 
|  | LongAlignment    = PointerSize; | 
|  | IntAlignment     = 4; | 
|  | ShortAlignment   = 2; | 
|  | ByteAlignment    = 1; | 
|  | BoolAlignment    = 1; | 
|  | } | 
|  |  | 
|  | /// Layouts - The lazy cache of structure layout information maintained by | 
|  | /// TargetData. | 
|  | /// | 
|  | static std::map<std::pair<const TargetData*,const StructType*>, | 
|  | StructLayout> *Layouts = 0; | 
|  |  | 
|  |  | 
|  | TargetData::~TargetData() { | 
|  | if (Layouts) { | 
|  | // Remove any layouts for this TD. | 
|  | std::map<std::pair<const TargetData*, | 
|  | const StructType*>, StructLayout>::iterator | 
|  | I = Layouts->lower_bound(std::make_pair(this, (const StructType*)0)); | 
|  | while (I != Layouts->end() && I->first.first == this) | 
|  | Layouts->erase(I++); | 
|  | if (Layouts->empty()) { | 
|  | delete Layouts; | 
|  | Layouts = 0; | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | const StructLayout *TargetData::getStructLayout(const StructType *Ty) const { | 
|  | if (Layouts == 0) | 
|  | Layouts = new std::map<std::pair<const TargetData*,const StructType*>, | 
|  | StructLayout>(); | 
|  | std::map<std::pair<const TargetData*,const StructType*>, | 
|  | StructLayout>::iterator | 
|  | I = Layouts->lower_bound(std::make_pair(this, Ty)); | 
|  | if (I != Layouts->end() && I->first.first == this && I->first.second == Ty) | 
|  | return &I->second; | 
|  | else { | 
|  | return &Layouts->insert(I, std::make_pair(std::make_pair(this, Ty), | 
|  | StructLayout(Ty, *this)))->second; | 
|  | } | 
|  | } | 
|  |  | 
|  | /// 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 TargetData::InvalidateStructLayoutInfo(const StructType *Ty) const { | 
|  | if (!Layouts) return;  // No cache. | 
|  |  | 
|  | std::map<std::pair<const TargetData*,const StructType*>, | 
|  | StructLayout>::iterator I = Layouts->find(std::make_pair(this, Ty)); | 
|  | if (I != Layouts->end()) | 
|  | Layouts->erase(I); | 
|  | } | 
|  |  | 
|  |  | 
|  |  | 
|  | static inline void getTypeInfo(const Type *Ty, const TargetData *TD, | 
|  | uint64_t &Size, unsigned char &Alignment) { | 
|  | assert(Ty->isSized() && "Cannot getTypeInfo() on a type that is unsized!"); | 
|  | switch (Ty->getTypeID()) { | 
|  | case Type::BoolTyID:   Size = 1; Alignment = TD->getBoolAlignment(); return; | 
|  | case Type::VoidTyID: | 
|  | case Type::UByteTyID: | 
|  | case Type::SByteTyID:  Size = 1; Alignment = TD->getByteAlignment(); return; | 
|  | case Type::UShortTyID: | 
|  | case Type::ShortTyID:  Size = 2; Alignment = TD->getShortAlignment(); return; | 
|  | case Type::UIntTyID: | 
|  | case Type::IntTyID:    Size = 4; Alignment = TD->getIntAlignment(); return; | 
|  | case Type::ULongTyID: | 
|  | case Type::LongTyID:   Size = 8; Alignment = TD->getLongAlignment(); return; | 
|  | case Type::FloatTyID:  Size = 4; Alignment = TD->getFloatAlignment(); return; | 
|  | case Type::DoubleTyID: Size = 8; Alignment = TD->getDoubleAlignment(); return; | 
|  | case Type::LabelTyID: | 
|  | case Type::PointerTyID: | 
|  | Size = TD->getPointerSize(); Alignment = TD->getPointerAlignment(); | 
|  | return; | 
|  | case Type::ArrayTyID: { | 
|  | const ArrayType *ATy = cast<ArrayType>(Ty); | 
|  | getTypeInfo(ATy->getElementType(), TD, Size, Alignment); | 
|  | unsigned AlignedSize = (Size + Alignment - 1)/Alignment*Alignment; | 
|  | Size = AlignedSize*ATy->getNumElements(); | 
|  | return; | 
|  | } | 
|  | case Type::PackedTyID: { | 
|  | const PackedType *PTy = cast<PackedType>(Ty); | 
|  | getTypeInfo(PTy->getElementType(), TD, Size, Alignment); | 
|  | unsigned AlignedSize = (Size + Alignment - 1)/Alignment*Alignment; | 
|  | Size = AlignedSize*PTy->getNumElements(); | 
|  | return; | 
|  | } | 
|  | case Type::StructTyID: { | 
|  | // Get the layout annotation... which is lazily created on demand. | 
|  | const StructLayout *Layout = TD->getStructLayout(cast<StructType>(Ty)); | 
|  | Size = Layout->StructSize; Alignment = Layout->StructAlignment; | 
|  | return; | 
|  | } | 
|  |  | 
|  | default: | 
|  | assert(0 && "Bad type for getTypeInfo!!!"); | 
|  | return; | 
|  | } | 
|  | } | 
|  |  | 
|  | uint64_t TargetData::getTypeSize(const Type *Ty) const { | 
|  | uint64_t Size; | 
|  | unsigned char Align; | 
|  | getTypeInfo(Ty, this, Size, Align); | 
|  | return Size; | 
|  | } | 
|  |  | 
|  | unsigned char TargetData::getTypeAlignment(const Type *Ty) const { | 
|  | uint64_t Size; | 
|  | unsigned char Align; | 
|  | getTypeInfo(Ty, this, Size, Align); | 
|  | return Align; | 
|  | } | 
|  |  | 
|  | unsigned char TargetData::getTypeAlignmentShift(const Type *Ty) const { | 
|  | unsigned Align = getTypeAlignment(Ty); | 
|  | assert(!(Align & (Align-1)) && "Alignment is not a power of two!"); | 
|  | return Log2_32(Align); | 
|  | } | 
|  |  | 
|  | /// getIntPtrType - Return an unsigned integer type that is the same size or | 
|  | /// greater to the host pointer size. | 
|  | const Type *TargetData::getIntPtrType() const { | 
|  | switch (getPointerSize()) { | 
|  | default: assert(0 && "Unknown pointer size!"); | 
|  | case 2: return Type::UShortTy; | 
|  | case 4: return Type::UIntTy; | 
|  | case 8: return Type::ULongTy; | 
|  | } | 
|  | } | 
|  |  | 
|  |  | 
|  | uint64_t TargetData::getIndexedOffset(const Type *ptrTy, | 
|  | const std::vector<Value*> &Idx) const { | 
|  | const Type *Ty = ptrTy; | 
|  | assert(isa<PointerType>(Ty) && "Illegal argument for getIndexedOffset()"); | 
|  | uint64_t Result = 0; | 
|  |  | 
|  | generic_gep_type_iterator<std::vector<Value*>::const_iterator> | 
|  | TI = gep_type_begin(ptrTy, Idx.begin(), Idx.end()); | 
|  | for (unsigned CurIDX = 0; CurIDX != Idx.size(); ++CurIDX, ++TI) { | 
|  | if (const StructType *STy = dyn_cast<StructType>(*TI)) { | 
|  | assert(Idx[CurIDX]->getType() == Type::UIntTy && "Illegal struct idx"); | 
|  | unsigned FieldNo = cast<ConstantUInt>(Idx[CurIDX])->getValue(); | 
|  |  | 
|  | // Get structure layout information... | 
|  | const StructLayout *Layout = getStructLayout(STy); | 
|  |  | 
|  | // Add in the offset, as calculated by the structure layout info... | 
|  | assert(FieldNo < Layout->MemberOffsets.size() &&"FieldNo out of range!"); | 
|  | Result += Layout->MemberOffsets[FieldNo]; | 
|  |  | 
|  | // Update Ty to refer to current element | 
|  | Ty = STy->getElementType(FieldNo); | 
|  | } else { | 
|  | // Update Ty to refer to current element | 
|  | Ty = cast<SequentialType>(Ty)->getElementType(); | 
|  |  | 
|  | // Get the array index and the size of each array element. | 
|  | int64_t arrayIdx = cast<ConstantInt>(Idx[CurIDX])->getRawValue(); | 
|  | Result += arrayIdx * (int64_t)getTypeSize(Ty); | 
|  | } | 
|  | } | 
|  |  | 
|  | return Result; | 
|  | } | 
|  |  |