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
13 // This structure should be created once, filled in if the defaults are not
14 // correct and then passed around by const&. None of the members functions
15 // require modification to the object.
17 //===----------------------------------------------------------------------===//
19 #include "llvm/Target/TargetData.h"
20 #include "llvm/Module.h"
21 #include "llvm/DerivedTypes.h"
22 #include "llvm/Constants.h"
23 #include "llvm/Support/GetElementPtrTypeIterator.h"
24 #include "llvm/Support/MathExtras.h"
25 #include "llvm/ADT/StringExtras.h"
31 // Handle the Pass registration stuff necessary to use TargetData's.
33 // Register the default SparcV9 implementation...
34 RegisterPass<TargetData> X("targetdata", "Target Data Layout");
37 static inline void getTypeInfo(const Type *Ty, const TargetData *TD,
38 uint64_t &Size, unsigned char &Alignment);
40 //===----------------------------------------------------------------------===//
41 // Support for StructLayout
42 //===----------------------------------------------------------------------===//
44 StructLayout::StructLayout(const StructType *ST, const TargetData &TD) {
48 // Loop over each of the elements, placing them in memory...
49 for (StructType::element_iterator TI = ST->element_begin(),
50 TE = ST->element_end(); TI != TE; ++TI) {
55 getTypeInfo(Ty, &TD, TySize, A);
58 // Add padding if necessary to make the data element aligned properly...
59 if (StructSize % TyAlign != 0)
60 StructSize = (StructSize/TyAlign + 1) * TyAlign; // Add padding...
62 // Keep track of maximum alignment constraint
63 StructAlignment = std::max(TyAlign, StructAlignment);
65 MemberOffsets.push_back(StructSize);
66 StructSize += TySize; // Consume space for this data item
69 // Empty structures have alignment of 1 byte.
70 if (StructAlignment == 0) StructAlignment = 1;
72 // Add padding to the end of the struct so that it could be put in an array
73 // and all array elements would be aligned correctly.
74 if (StructSize % StructAlignment != 0)
75 StructSize = (StructSize/StructAlignment + 1) * StructAlignment;
79 /// getElementContainingOffset - Given a valid offset into the structure,
80 /// return the structure index that contains it.
81 unsigned StructLayout::getElementContainingOffset(uint64_t Offset) const {
82 std::vector<uint64_t>::const_iterator SI =
83 std::upper_bound(MemberOffsets.begin(), MemberOffsets.end(),
85 assert(SI != MemberOffsets.begin() && "Offset not in structure type!");
87 assert(*SI <= Offset && "upper_bound didn't work");
88 assert((SI == MemberOffsets.begin() || *(SI-1) < Offset) &&
89 (SI+1 == MemberOffsets.end() || *(SI+1) > Offset) &&
90 "Upper bound didn't work!");
91 return SI-MemberOffsets.begin();
94 //===----------------------------------------------------------------------===//
95 // TargetData Class Implementation
96 //===----------------------------------------------------------------------===//
98 TargetData::TargetData(const std::string &TargetName,
99 bool isLittleEndian, unsigned char PtrSize,
100 unsigned char PtrAl, unsigned char DoubleAl,
101 unsigned char FloatAl, unsigned char LongAl,
102 unsigned char IntAl, unsigned char ShortAl,
103 unsigned char ByteAl, unsigned char BoolAl) {
105 // If this assert triggers, a pass "required" TargetData information, but the
106 // top level tool did not provide one for it. We do not want to default
107 // construct, or else we might end up using a bad endianness or pointer size!
109 assert(!TargetName.empty() &&
110 "ERROR: Tool did not specify a target data to use!");
112 LittleEndian = isLittleEndian;
113 PointerSize = PtrSize;
114 PointerAlignment = PtrAl;
115 DoubleAlignment = DoubleAl;
116 FloatAlignment = FloatAl;
117 LongAlignment = LongAl;
118 IntAlignment = IntAl;
119 ShortAlignment = ShortAl;
120 ByteAlignment = ByteAl;
121 BoolAlignment = BoolAl;
124 TargetData::TargetData(const std::string &TargetName,
125 const std::string &TargetDescription) {
126 std::string temp = TargetDescription;
128 LittleEndian = false;
130 PointerAlignment = 8;
139 while (temp.length() > 0) {
140 std::string token = getToken(temp, "-");
144 LittleEndian = false;
150 PointerSize = atoi(getToken(token,":").c_str()) / 8;
151 PointerAlignment = atoi(getToken(token,":").c_str()) / 8;
154 token = getToken(token,":"); //Ignore the size
155 DoubleAlignment = atoi(getToken(token,":").c_str()) / 8;
158 token = getToken(token, ":"); //Ignore the size
159 FloatAlignment = atoi(getToken(token, ":").c_str()) / 8;
162 token = getToken(token, ":"); //Ignore the size
163 LongAlignment = atoi(getToken(token, ":").c_str()) / 8;
166 token = getToken(token, ":"); //Ignore the size
167 IntAlignment = atoi(getToken(token, ":").c_str()) / 8;
170 token = getToken(token, ":"); //Ignore the size
171 ShortAlignment = atoi(getToken(token, ":").c_str()) / 8;
174 token = getToken(token, ":"); //Ignore the size
175 ByteAlignment = atoi(getToken(token, ":").c_str()) / 8;
178 token = getToken(token, ":"); //Ignore the size
179 BoolAlignment = atoi(getToken(token, ":").c_str()) / 8;
187 TargetData::TargetData(const std::string &ToolName, const Module *M) {
188 LittleEndian = M->getEndianness() != Module::BigEndian;
189 PointerSize = M->getPointerSize() != Module::Pointer64 ? 4 : 8;
190 PointerAlignment = PointerSize;
191 DoubleAlignment = PointerSize;
193 LongAlignment = PointerSize;
200 /// Layouts - The lazy cache of structure layout information maintained by
203 static std::map<std::pair<const TargetData*,const StructType*>,
204 StructLayout> *Layouts = 0;
207 TargetData::~TargetData() {
209 // Remove any layouts for this TD.
210 std::map<std::pair<const TargetData*,
211 const StructType*>, StructLayout>::iterator
212 I = Layouts->lower_bound(std::make_pair(this, (const StructType*)0));
213 while (I != Layouts->end() && I->first.first == this)
215 if (Layouts->empty()) {
222 std::string TargetData::getStringRepresentation() const {
223 std::stringstream repr;
230 repr << "-p:" << (PointerSize * 8) << ":" << (PointerAlignment * 8);
231 repr << "-d:64:" << (DoubleAlignment * 8);
232 repr << "-f:32:" << (FloatAlignment * 8);
233 repr << "-l:64:" << (LongAlignment * 8);
234 repr << "-i:32:" << (IntAlignment * 8);
235 repr << "-s:16:" << (ShortAlignment * 8);
236 repr << "-b:8:" << (ByteAlignment * 8);
237 repr << "-B:8:" << (BoolAlignment * 8);
242 const StructLayout *TargetData::getStructLayout(const StructType *Ty) const {
244 Layouts = new std::map<std::pair<const TargetData*,const StructType*>,
246 std::map<std::pair<const TargetData*,const StructType*>,
247 StructLayout>::iterator
248 I = Layouts->lower_bound(std::make_pair(this, Ty));
249 if (I != Layouts->end() && I->first.first == this && I->first.second == Ty)
252 return &Layouts->insert(I, std::make_pair(std::make_pair(this, Ty),
253 StructLayout(Ty, *this)))->second;
257 /// InvalidateStructLayoutInfo - TargetData speculatively caches StructLayout
258 /// objects. If a TargetData object is alive when types are being refined and
259 /// removed, this method must be called whenever a StructType is removed to
260 /// avoid a dangling pointer in this cache.
261 void TargetData::InvalidateStructLayoutInfo(const StructType *Ty) const {
262 if (!Layouts) return; // No cache.
264 std::map<std::pair<const TargetData*,const StructType*>,
265 StructLayout>::iterator I = Layouts->find(std::make_pair(this, Ty));
266 if (I != Layouts->end())
272 static inline void getTypeInfo(const Type *Ty, const TargetData *TD,
273 uint64_t &Size, unsigned char &Alignment) {
274 assert(Ty->isSized() && "Cannot getTypeInfo() on a type that is unsized!");
275 switch (Ty->getTypeID()) {
276 case Type::BoolTyID: Size = 1; Alignment = TD->getBoolAlignment(); return;
278 case Type::UByteTyID:
279 case Type::SByteTyID: Size = 1; Alignment = TD->getByteAlignment(); return;
280 case Type::UShortTyID:
281 case Type::ShortTyID: Size = 2; Alignment = TD->getShortAlignment(); return;
283 case Type::IntTyID: Size = 4; Alignment = TD->getIntAlignment(); return;
284 case Type::ULongTyID:
285 case Type::LongTyID: Size = 8; Alignment = TD->getLongAlignment(); return;
286 case Type::FloatTyID: Size = 4; Alignment = TD->getFloatAlignment(); return;
287 case Type::DoubleTyID: Size = 8; Alignment = TD->getDoubleAlignment(); return;
288 case Type::LabelTyID:
289 case Type::PointerTyID:
290 Size = TD->getPointerSize(); Alignment = TD->getPointerAlignment();
292 case Type::ArrayTyID: {
293 const ArrayType *ATy = cast<ArrayType>(Ty);
294 getTypeInfo(ATy->getElementType(), TD, Size, Alignment);
295 unsigned AlignedSize = (Size + Alignment - 1)/Alignment*Alignment;
296 Size = AlignedSize*ATy->getNumElements();
299 case Type::PackedTyID: {
300 const PackedType *PTy = cast<PackedType>(Ty);
301 getTypeInfo(PTy->getElementType(), TD, Size, Alignment);
302 unsigned AlignedSize = (Size + Alignment - 1)/Alignment*Alignment;
303 Size = AlignedSize*PTy->getNumElements();
304 // FIXME: The alignments of specific packed types are target dependent.
305 // For now, just set it to be equal to Size.
309 case Type::StructTyID: {
310 // Get the layout annotation... which is lazily created on demand.
311 const StructLayout *Layout = TD->getStructLayout(cast<StructType>(Ty));
312 Size = Layout->StructSize; Alignment = Layout->StructAlignment;
317 assert(0 && "Bad type for getTypeInfo!!!");
322 uint64_t TargetData::getTypeSize(const Type *Ty) const {
325 getTypeInfo(Ty, this, Size, Align);
329 unsigned char TargetData::getTypeAlignment(const Type *Ty) const {
332 getTypeInfo(Ty, this, Size, Align);
336 unsigned char TargetData::getTypeAlignmentShift(const Type *Ty) const {
337 unsigned Align = getTypeAlignment(Ty);
338 assert(!(Align & (Align-1)) && "Alignment is not a power of two!");
339 return Log2_32(Align);
342 /// getIntPtrType - Return an unsigned integer type that is the same size or
343 /// greater to the host pointer size.
344 const Type *TargetData::getIntPtrType() const {
345 switch (getPointerSize()) {
346 default: assert(0 && "Unknown pointer size!");
347 case 2: return Type::UShortTy;
348 case 4: return Type::UIntTy;
349 case 8: return Type::ULongTy;
354 uint64_t TargetData::getIndexedOffset(const Type *ptrTy,
355 const std::vector<Value*> &Idx) const {
356 const Type *Ty = ptrTy;
357 assert(isa<PointerType>(Ty) && "Illegal argument for getIndexedOffset()");
360 generic_gep_type_iterator<std::vector<Value*>::const_iterator>
361 TI = gep_type_begin(ptrTy, Idx.begin(), Idx.end());
362 for (unsigned CurIDX = 0; CurIDX != Idx.size(); ++CurIDX, ++TI) {
363 if (const StructType *STy = dyn_cast<StructType>(*TI)) {
364 assert(Idx[CurIDX]->getType() == Type::UIntTy && "Illegal struct idx");
365 unsigned FieldNo = cast<ConstantUInt>(Idx[CurIDX])->getValue();
367 // Get structure layout information...
368 const StructLayout *Layout = getStructLayout(STy);
370 // Add in the offset, as calculated by the structure layout info...
371 assert(FieldNo < Layout->MemberOffsets.size() &&"FieldNo out of range!");
372 Result += Layout->MemberOffsets[FieldNo];
374 // Update Ty to refer to current element
375 Ty = STy->getElementType(FieldNo);
377 // Update Ty to refer to current element
378 Ty = cast<SequentialType>(Ty)->getElementType();
380 // Get the array index and the size of each array element.
381 int64_t arrayIdx = cast<ConstantInt>(Idx[CurIDX])->getRawValue();
382 Result += arrayIdx * (int64_t)getTypeSize(Ty);