1 //===-- TargetData.cpp - Data size & alignment routines --------------------==//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines target properties related to datatype size/offset/alignment
11 // information. It uses lazy annotations to cache information about how
12 // structure types are laid out and used.
14 // This structure should be created once, filled in if the defaults are not
15 // correct and then passed around by const&. None of the members functions
16 // require modification to the object.
18 //===----------------------------------------------------------------------===//
20 #include "llvm/Target/TargetData.h"
21 #include "llvm/Module.h"
22 #include "llvm/DerivedTypes.h"
23 #include "llvm/Constants.h"
26 // Handle the Pass registration stuff necessary to use TargetData's.
28 // Register the default SparcV9 implementation...
29 RegisterPass<TargetData> X("targetdata", "Target Data Layout");
32 static inline void getTypeInfo(const Type *Ty, const TargetData *TD,
33 uint64_t &Size, unsigned char &Alignment);
35 //===----------------------------------------------------------------------===//
36 // Support for StructLayout Annotation
37 //===----------------------------------------------------------------------===//
39 StructLayout::StructLayout(const StructType *ST, const TargetData &TD)
40 : Annotation(TD.getStructLayoutAID()) {
44 // Loop over each of the elements, placing them in memory...
45 for (StructType::element_iterator TI = ST->element_begin(),
46 TE = ST->element_end(); TI != TE; ++TI) {
51 getTypeInfo(Ty, &TD, TySize, A);
54 // Add padding if necessary to make the data element aligned properly...
55 if (StructSize % TyAlign != 0)
56 StructSize = (StructSize/TyAlign + 1) * TyAlign; // Add padding...
58 // Keep track of maximum alignment constraint
59 StructAlignment = std::max(TyAlign, StructAlignment);
61 MemberOffsets.push_back(StructSize);
62 StructSize += TySize; // Consume space for this data item
65 // Empty structures have alignment of 1 byte.
66 if (StructAlignment == 0) StructAlignment = 1;
68 // Add padding to the end of the struct so that it could be put in an array
69 // and all array elements would be aligned correctly.
70 if (StructSize % StructAlignment != 0)
71 StructSize = (StructSize/StructAlignment + 1) * StructAlignment;
74 Annotation *TargetData::TypeAnFactory(AnnotationID AID, const Annotable *T,
76 const TargetData &TD = *(const TargetData*)D;
77 assert(AID == TD.AID && "Target data annotation ID mismatch!");
78 const Type *Ty = cast<Type>((const Value *)T);
79 assert(isa<StructType>(Ty) &&
80 "Can only create StructLayout annotation on structs!");
81 return new StructLayout(cast<StructType>(Ty), TD);
84 //===----------------------------------------------------------------------===//
85 // TargetData Class Implementation
86 //===----------------------------------------------------------------------===//
88 TargetData::TargetData(const std::string &TargetName,
89 bool isLittleEndian, unsigned char PtrSize,
90 unsigned char PtrAl, unsigned char DoubleAl,
91 unsigned char FloatAl, unsigned char LongAl,
92 unsigned char IntAl, unsigned char ShortAl,
94 : AID(AnnotationManager::getID("TargetData::" + TargetName)) {
95 AnnotationManager::registerAnnotationFactory(AID, TypeAnFactory, this);
97 // If this assert triggers, a pass "required" TargetData information, but the
98 // top level tool did not provide once for it. We do not want to default
99 // construct, or else we might end up using a bad endianness or pointer size!
101 assert(!TargetName.empty() &&
102 "ERROR: Tool did not specify a target data to use!");
104 LittleEndian = isLittleEndian;
105 PointerSize = PtrSize;
106 PointerAlignment = PtrAl;
107 DoubleAlignment = DoubleAl;
108 assert(DoubleAlignment == PtrAl &&
109 "Double alignment and pointer alignment agree for now!");
110 FloatAlignment = FloatAl;
111 LongAlignment = LongAl;
112 IntAlignment = IntAl;
113 ShortAlignment = ShortAl;
114 ByteAlignment = ByteAl;
117 TargetData::TargetData(const std::string &ToolName, const Module *M)
118 : AID(AnnotationManager::getID("TargetData::" + ToolName)) {
119 AnnotationManager::registerAnnotationFactory(AID, TypeAnFactory, this);
121 LittleEndian = M->getEndianness() != Module::BigEndian;
122 PointerSize = M->getPointerSize() != Module::Pointer64 ? 4 : 8;
123 PointerAlignment = PointerSize;
124 DoubleAlignment = PointerSize;
132 TargetData::~TargetData() {
133 AnnotationManager::registerAnnotationFactory(AID, 0); // Deregister factory
136 static inline void getTypeInfo(const Type *Ty, const TargetData *TD,
137 uint64_t &Size, unsigned char &Alignment) {
138 assert(Ty->isSized() && "Cannot getTypeInfo() on a type that is unsized!");
139 switch (Ty->getPrimitiveID()) {
142 case Type::UByteTyID:
143 case Type::SByteTyID: Size = 1; Alignment = TD->getByteAlignment(); return;
144 case Type::UShortTyID:
145 case Type::ShortTyID: Size = 2; Alignment = TD->getShortAlignment(); return;
147 case Type::IntTyID: Size = 4; Alignment = TD->getIntAlignment(); return;
148 case Type::ULongTyID:
149 case Type::LongTyID: Size = 8; Alignment = TD->getLongAlignment(); return;
150 case Type::FloatTyID: Size = 4; Alignment = TD->getFloatAlignment(); return;
151 case Type::DoubleTyID: Size = 8; Alignment = TD->getDoubleAlignment(); return;
152 case Type::LabelTyID:
153 case Type::PointerTyID:
154 Size = TD->getPointerSize(); Alignment = TD->getPointerAlignment();
156 case Type::ArrayTyID: {
157 const ArrayType *ATy = (const ArrayType *)Ty;
158 getTypeInfo(ATy->getElementType(), TD, Size, Alignment);
159 Size *= ATy->getNumElements();
162 case Type::StructTyID: {
163 // Get the layout annotation... which is lazily created on demand.
164 const StructLayout *Layout = TD->getStructLayout((const StructType*)Ty);
165 Size = Layout->StructSize; Alignment = Layout->StructAlignment;
171 assert(0 && "Bad type for getTypeInfo!!!");
176 uint64_t TargetData::getTypeSize(const Type *Ty) const {
179 getTypeInfo(Ty, this, Size, Align);
183 unsigned char TargetData::getTypeAlignment(const Type *Ty) const {
186 getTypeInfo(Ty, this, Size, Align);
190 /// getIntPtrType - Return an unsigned integer type that is the same size or
191 /// greater to the host pointer size.
192 const Type *TargetData::getIntPtrType() const {
193 switch (getPointerSize()) {
194 default: assert(0 && "Unknown pointer size!");
195 case 2: return Type::UShortTy;
196 case 4: return Type::UIntTy;
197 case 8: return Type::ULongTy;
202 uint64_t TargetData::getIndexedOffset(const Type *ptrTy,
203 const std::vector<Value*> &Idx) const {
204 const Type *Ty = ptrTy;
205 assert(isa<PointerType>(Ty) && "Illegal argument for getIndexedOffset()");
208 for (unsigned CurIDX = 0; CurIDX != Idx.size(); ++CurIDX) {
209 if (Idx[CurIDX]->getType() == Type::LongTy) {
210 // Update Ty to refer to current element
211 Ty = cast<SequentialType>(Ty)->getElementType();
213 // Get the array index and the size of each array element.
214 int64_t arrayIdx = cast<ConstantSInt>(Idx[CurIDX])->getValue();
215 Result += arrayIdx * (int64_t)getTypeSize(Ty);
217 const StructType *STy = cast<StructType>(Ty);
218 assert(Idx[CurIDX]->getType() == Type::UByteTy && "Illegal struct idx");
219 unsigned FieldNo = cast<ConstantUInt>(Idx[CurIDX])->getValue();
221 // Get structure layout information...
222 const StructLayout *Layout = getStructLayout(STy);
224 // Add in the offset, as calculated by the structure layout info...
225 assert(FieldNo < Layout->MemberOffsets.size() &&"FieldNo out of range!");
226 Result += Layout->MemberOffsets[FieldNo];
228 // Update Ty to refer to current element
229 Ty = STy->getElementType(FieldNo);