1 //===-- TargetData.cpp - Data size & alignment routines --------------------==//
3 // This file defines target properties related to datatype size/offset/alignment
4 // information. It uses lazy annotations to cache information about how
5 // structure types are laid out and used.
7 // This structure should be created once, filled in if the defaults are not
8 // correct and then passed around by const&. None of the members functions
9 // require modification to the object.
11 //===----------------------------------------------------------------------===//
13 #include "llvm/Target/TargetData.h"
14 #include "llvm/DerivedTypes.h"
15 #include "llvm/Constants.h"
17 // Handle the Pass registration stuff neccesary to use TargetData's.
19 // Register the default SparcV9 implementation...
20 RegisterPass<TargetData> X("targetdata", "Target Data Layout");
24 static inline void getTypeInfo(const Type *Ty, const TargetData *TD,
25 uint64_t &Size, unsigned char &Alignment);
27 //===----------------------------------------------------------------------===//
28 // Support for StructLayout Annotation
29 //===----------------------------------------------------------------------===//
31 StructLayout::StructLayout(const StructType *ST, const TargetData &TD)
32 : Annotation(TD.getStructLayoutAID()) {
36 // Loop over each of the elements, placing them in memory...
37 for (StructType::ElementTypes::const_iterator
38 TI = ST->getElementTypes().begin(),
39 TE = ST->getElementTypes().end(); TI != TE; ++TI) {
44 getTypeInfo(Ty, &TD, TySize, A);
47 // Add padding if neccesary to make the data element aligned properly...
48 if (StructSize % TyAlign != 0)
49 StructSize = (StructSize/TyAlign + 1) * TyAlign; // Add padding...
51 // Keep track of maximum alignment constraint
52 StructAlignment = std::max(TyAlign, StructAlignment);
54 MemberOffsets.push_back(StructSize);
55 StructSize += TySize; // Consume space for this data item
58 // Add padding to the end of the struct so that it could be put in an array
59 // and all array elements would be aligned correctly.
60 if (StructSize % StructAlignment != 0)
61 StructSize = (StructSize/StructAlignment + 1) * StructAlignment;
63 if (StructSize == 0) {
64 StructSize = 1; // Empty struct is 1 byte
69 Annotation *TargetData::TypeAnFactory(AnnotationID AID, const Annotable *T,
71 const TargetData &TD = *(const TargetData*)D;
72 assert(AID == TD.AID && "Target data annotation ID mismatch!");
73 const Type *Ty = cast<const Type>((const Value *)T);
74 assert(isa<StructType>(Ty) &&
75 "Can only create StructLayout annotation on structs!");
76 return new StructLayout((const StructType *)Ty, TD);
79 //===----------------------------------------------------------------------===//
80 // TargetData Class Implementation
81 //===----------------------------------------------------------------------===//
83 TargetData::TargetData(const std::string &TargetName,
85 unsigned char IntRegSize, unsigned char PtrSize,
86 unsigned char PtrAl, unsigned char DoubleAl,
87 unsigned char FloatAl, unsigned char LongAl,
88 unsigned char IntAl, unsigned char ShortAl,
90 : AID(AnnotationManager::getID("TargetData::" + TargetName)) {
91 AnnotationManager::registerAnnotationFactory(AID, TypeAnFactory, this);
93 LittleEndian = isLittleEndian;
94 IntegerRegSize = IntRegSize;
95 PointerSize = PtrSize;
96 PointerAlignment = PtrAl;
97 DoubleAlignment = DoubleAl;
98 FloatAlignment = FloatAl;
99 LongAlignment = LongAl;
100 IntAlignment = IntAl;
101 ShortAlignment = ShortAl;
102 ByteAlignment = ByteAl;
105 TargetData::~TargetData() {
106 AnnotationManager::registerAnnotationFactory(AID, 0); // Deregister factory
109 static inline void getTypeInfo(const Type *Ty, const TargetData *TD,
110 uint64_t &Size, unsigned char &Alignment) {
111 assert(Ty->isSized() && "Cannot getTypeInfo() on a type that is unsized!");
112 switch (Ty->getPrimitiveID()) {
115 case Type::UByteTyID:
116 case Type::SByteTyID: Size = 1; Alignment = TD->getByteAlignment(); return;
117 case Type::UShortTyID:
118 case Type::ShortTyID: Size = 2; Alignment = TD->getShortAlignment(); return;
120 case Type::IntTyID: Size = 4; Alignment = TD->getIntAlignment(); return;
121 case Type::ULongTyID:
122 case Type::LongTyID: Size = 8; Alignment = TD->getLongAlignment(); return;
123 case Type::FloatTyID: Size = 4; Alignment = TD->getFloatAlignment(); return;
124 case Type::DoubleTyID: Size = 8; Alignment = TD->getDoubleAlignment(); return;
125 case Type::LabelTyID:
126 case Type::PointerTyID:
127 Size = TD->getPointerSize(); Alignment = TD->getPointerAlignment();
129 case Type::ArrayTyID: {
130 const ArrayType *ATy = (const ArrayType *)Ty;
131 getTypeInfo(ATy->getElementType(), TD, Size, Alignment);
132 Size *= ATy->getNumElements();
135 case Type::StructTyID: {
136 // Get the layout annotation... which is lazily created on demand.
137 const StructLayout *Layout = TD->getStructLayout((const StructType*)Ty);
138 Size = Layout->StructSize; Alignment = Layout->StructAlignment;
144 assert(0 && "Bad type for getTypeInfo!!!");
149 uint64_t TargetData::getTypeSize(const Type *Ty) const {
152 getTypeInfo(Ty, this, Size, Align);
156 unsigned char TargetData::getTypeAlignment(const Type *Ty) const {
159 getTypeInfo(Ty, this, Size, Align);
163 uint64_t TargetData::getIndexedOffset(const Type *ptrTy,
164 const std::vector<Value*> &Idx) const {
165 const Type *Ty = ptrTy;
166 assert(isa<PointerType>(Ty) && "Illegal argument for getIndexedOffset()");
169 for (unsigned CurIDX = 0; CurIDX != Idx.size(); ++CurIDX) {
170 if (Idx[CurIDX]->getType() == Type::LongTy) {
171 // Update Ty to refer to current element
172 Ty = cast<SequentialType>(Ty)->getElementType();
174 // Get the array index and the size of each array element.
175 // Both must be known constants, or the index shd be 0; else this fails.
176 int64_t arrayIdx = cast<ConstantSInt>(Idx[CurIDX])->getValue();
177 Result += arrayIdx == 0? 0
178 : (uint64_t) (arrayIdx * (int64_t) getTypeSize(Ty));
180 } else if (const StructType *STy = dyn_cast<const StructType>(Ty)) {
181 assert(Idx[CurIDX]->getType() == Type::UByteTy && "Illegal struct idx");
182 unsigned FieldNo = cast<ConstantUInt>(Idx[CurIDX])->getValue();
184 // Get structure layout information...
185 const StructLayout *Layout = getStructLayout(STy);
187 // Add in the offset, as calculated by the structure layout info...
188 assert(FieldNo < Layout->MemberOffsets.size() &&"FieldNo out of range!");
189 Result += Layout->MemberOffsets[FieldNo];
191 // Update Ty to refer to current element
192 Ty = STy->getElementTypes()[FieldNo];
194 } else if (isa<const ArrayType>(Ty)) {
195 assert(0 && "Loading from arrays not implemented yet!");
197 assert(0 && "Indexing type that is not struct or array?");
198 return 0; // Load directly through ptr