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 getTypeInfoABI(const Type *Ty, const TargetData *TD,
38 uint64_t &Size, unsigned char &Alignment);
40 static inline void getTypeInfoPref(const Type *Ty, const TargetData *TD,
41 uint64_t &Size, unsigned char &Alignment);
43 //===----------------------------------------------------------------------===//
44 // Support for StructLayout
45 //===----------------------------------------------------------------------===//
47 StructLayout::StructLayout(const StructType *ST, const TargetData &TD) {
51 // Loop over each of the elements, placing them in memory...
52 for (StructType::element_iterator TI = ST->element_begin(),
53 TE = ST->element_end(); TI != TE; ++TI) {
58 getTypeInfoABI(Ty, &TD, TySize, A);
59 TyAlign = ST->isPacked() ? 1 : A;
61 // Add padding if necessary to make the data element aligned properly...
62 if (StructSize % TyAlign != 0)
63 StructSize = (StructSize/TyAlign + 1) * TyAlign; // Add padding...
65 // Keep track of maximum alignment constraint
66 StructAlignment = std::max(TyAlign, StructAlignment);
68 MemberOffsets.push_back(StructSize);
69 StructSize += TySize; // Consume space for this data item
72 // Empty structures have alignment of 1 byte.
73 if (StructAlignment == 0) StructAlignment = 1;
75 // Add padding to the end of the struct so that it could be put in an array
76 // and all array elements would be aligned correctly.
77 if (StructSize % StructAlignment != 0)
78 StructSize = (StructSize/StructAlignment + 1) * StructAlignment;
82 /// getElementContainingOffset - Given a valid offset into the structure,
83 /// return the structure index that contains it.
84 unsigned StructLayout::getElementContainingOffset(uint64_t Offset) const {
85 std::vector<uint64_t>::const_iterator SI =
86 std::upper_bound(MemberOffsets.begin(), MemberOffsets.end(), Offset);
87 assert(SI != MemberOffsets.begin() && "Offset not in structure type!");
89 assert(*SI <= Offset && "upper_bound didn't work");
90 assert((SI == MemberOffsets.begin() || *(SI-1) < Offset) &&
91 (SI+1 == MemberOffsets.end() || *(SI+1) > Offset) &&
92 "Upper bound didn't work!");
93 return SI-MemberOffsets.begin();
96 //===----------------------------------------------------------------------===//
97 // TargetData Class Implementation
98 //===----------------------------------------------------------------------===//
100 void TargetData::init(const std::string &TargetDescription) {
101 std::string temp = TargetDescription;
103 LittleEndian = false;
105 PointerABIAlignment = 8;
106 DoubleABIAlignment = 0;
107 FloatABIAlignment = 4;
108 LongABIAlignment = 0;
110 ShortABIAlignment = 2;
111 ByteABIAlignment = 1;
112 BoolABIAlignment = 1;
113 BoolPrefAlignment = BoolABIAlignment;
114 BytePrefAlignment = ByteABIAlignment;
115 ShortPrefAlignment = ShortABIAlignment;
116 IntPrefAlignment = IntABIAlignment;
117 LongPrefAlignment = 8;
118 FloatPrefAlignment = FloatABIAlignment;
119 DoublePrefAlignment = 8;
120 PointerPrefAlignment = PointerABIAlignment;
121 AggMinPrefAlignment = 0;
123 while (!temp.empty()) {
124 std::string token = getToken(temp, "-");
126 char signal = getToken(token, ":")[0];
130 LittleEndian = false;
136 PointerMemSize = atoi(getToken(token,":").c_str()) / 8;
137 PointerABIAlignment = atoi(getToken(token,":").c_str()) / 8;
138 PointerPrefAlignment = atoi(getToken(token,":").c_str()) / 8;
139 if (PointerPrefAlignment == 0)
140 PointerPrefAlignment = PointerABIAlignment;
143 DoubleABIAlignment = atoi(getToken(token,":").c_str()) / 8;
144 DoublePrefAlignment = atoi(getToken(token,":").c_str()) / 8;
145 if (DoublePrefAlignment == 0)
146 DoublePrefAlignment = DoubleABIAlignment;
149 FloatABIAlignment = atoi(getToken(token, ":").c_str()) / 8;
150 FloatPrefAlignment = atoi(getToken(token,":").c_str()) / 8;
151 if (FloatPrefAlignment == 0)
152 FloatPrefAlignment = FloatABIAlignment;
155 LongABIAlignment = atoi(getToken(token, ":").c_str()) / 8;
156 LongPrefAlignment = atoi(getToken(token,":").c_str()) / 8;
157 if (LongPrefAlignment == 0)
158 LongPrefAlignment = LongABIAlignment;
161 IntABIAlignment = atoi(getToken(token, ":").c_str()) / 8;
162 IntPrefAlignment = atoi(getToken(token,":").c_str()) / 8;
163 if (IntPrefAlignment == 0)
164 IntPrefAlignment = IntABIAlignment;
167 ShortABIAlignment = atoi(getToken(token, ":").c_str()) / 8;
168 ShortPrefAlignment = atoi(getToken(token,":").c_str()) / 8;
169 if (ShortPrefAlignment == 0)
170 ShortPrefAlignment = ShortABIAlignment;
173 ByteABIAlignment = atoi(getToken(token, ":").c_str()) / 8;
174 BytePrefAlignment = atoi(getToken(token,":").c_str()) / 8;
175 if (BytePrefAlignment == 0)
176 BytePrefAlignment = ByteABIAlignment;
179 BoolABIAlignment = atoi(getToken(token, ":").c_str()) / 8;
180 BoolPrefAlignment = atoi(getToken(token,":").c_str()) / 8;
181 if (BoolPrefAlignment == 0)
182 BoolPrefAlignment = BoolABIAlignment;
185 AggMinPrefAlignment = atoi(getToken(token,":").c_str()) / 8;
192 // Unless explicitly specified, the alignments for longs and doubles is
193 // capped by pointer size.
194 if (LongABIAlignment == 0)
195 LongABIAlignment = LongPrefAlignment = PointerMemSize;
196 if (DoubleABIAlignment == 0)
197 DoubleABIAlignment = DoublePrefAlignment = PointerMemSize;
200 TargetData::TargetData(const Module *M) {
201 init(M->getDataLayout());
204 /// Layouts - The lazy cache of structure layout information maintained by
207 static std::map<std::pair<const TargetData*,const StructType*>,
208 StructLayout> *Layouts = 0;
211 TargetData::~TargetData() {
213 // Remove any layouts for this TD.
214 std::map<std::pair<const TargetData*,
215 const StructType*>, StructLayout>::iterator
216 I = Layouts->lower_bound(std::make_pair(this, (const StructType*)0));
217 while (I != Layouts->end() && I->first.first == this)
219 if (Layouts->empty()) {
226 std::string TargetData::getStringRepresentation() const {
227 std::stringstream repr;
234 repr << "-p:" << (PointerMemSize * 8) << ":" << (PointerABIAlignment * 8);
235 repr << "-d:" << (DoubleABIAlignment * 8) << ":"
236 << (DoublePrefAlignment * 8);
237 repr << "-f:" << (FloatABIAlignment * 8) << ":"
238 << (FloatPrefAlignment * 8);
239 repr << "-l:" << (LongABIAlignment * 8) << ":"
240 << (LongPrefAlignment * 8);
241 repr << "-i:" << (IntABIAlignment * 8) << ":"
242 << (IntPrefAlignment * 8);
243 repr << "-s:" << (ShortABIAlignment * 8) << ":"
244 << (ShortPrefAlignment * 8);
245 repr << "-b:" << (ByteABIAlignment * 8) << ":"
246 << (BytePrefAlignment * 8);
247 repr << "-B:" << (BoolABIAlignment * 8) << ":"
248 << (BoolPrefAlignment * 8);
249 repr << "-A:" << (AggMinPrefAlignment * 8);
254 const StructLayout *TargetData::getStructLayout(const StructType *Ty) const {
256 Layouts = new std::map<std::pair<const TargetData*,const StructType*>,
258 std::map<std::pair<const TargetData*,const StructType*>,
259 StructLayout>::iterator
260 I = Layouts->lower_bound(std::make_pair(this, Ty));
261 if (I != Layouts->end() && I->first.first == this && I->first.second == Ty)
264 return &Layouts->insert(I, std::make_pair(std::make_pair(this, Ty),
265 StructLayout(Ty, *this)))->second;
269 /// InvalidateStructLayoutInfo - TargetData speculatively caches StructLayout
270 /// objects. If a TargetData object is alive when types are being refined and
271 /// removed, this method must be called whenever a StructType is removed to
272 /// avoid a dangling pointer in this cache.
273 void TargetData::InvalidateStructLayoutInfo(const StructType *Ty) const {
274 if (!Layouts) return; // No cache.
276 std::map<std::pair<const TargetData*,const StructType*>,
277 StructLayout>::iterator I = Layouts->find(std::make_pair(this, Ty));
278 if (I != Layouts->end())
284 static inline void getTypeInfoABI(const Type *Ty, const TargetData *TD,
285 uint64_t &Size, unsigned char &Alignment) {
286 assert(Ty->isSized() && "Cannot getTypeInfo() on a type that is unsized!");
287 switch (Ty->getTypeID()) {
288 case Type::IntegerTyID: {
289 unsigned BitWidth = cast<IntegerType>(Ty)->getBitWidth();
291 Size = 1; Alignment = TD->getByteABIAlignment();
292 } else if (BitWidth <= 16) {
293 Size = 2; Alignment = TD->getShortABIAlignment();
294 } else if (BitWidth <= 32) {
295 Size = 4; Alignment = TD->getIntABIAlignment();
296 } else if (BitWidth <= 64) {
297 Size = 8; Alignment = TD->getLongABIAlignment();
299 Size = ((BitWidth + 7) / 8) & ~1;
300 Alignment = TD->getLongABIAlignment();
304 case Type::VoidTyID: Size = 1; Alignment = TD->getByteABIAlignment(); return;
305 case Type::FloatTyID: Size = 4; Alignment = TD->getFloatABIAlignment(); return;
306 case Type::DoubleTyID: Size = 8; Alignment = TD->getDoubleABIAlignment(); return;
307 case Type::LabelTyID:
308 case Type::PointerTyID:
309 Size = TD->getPointerSize(); Alignment = TD->getPointerABIAlignment();
311 case Type::ArrayTyID: {
312 const ArrayType *ATy = cast<ArrayType>(Ty);
313 getTypeInfoABI(ATy->getElementType(), TD, Size, Alignment);
314 unsigned AlignedSize = (Size + Alignment - 1)/Alignment*Alignment;
315 Size = AlignedSize*ATy->getNumElements();
318 case Type::PackedTyID: {
319 const PackedType *PTy = cast<PackedType>(Ty);
320 getTypeInfoABI(PTy->getElementType(), TD, Size, Alignment);
321 unsigned AlignedSize = (Size + Alignment - 1)/Alignment*Alignment;
322 Size = AlignedSize*PTy->getNumElements();
323 // FIXME: The alignments of specific packed types are target dependent.
324 // For now, just set it to be equal to Size.
328 case Type::StructTyID: {
329 // Get the layout annotation... which is lazily created on demand.
330 const StructLayout *Layout = TD->getStructLayout(cast<StructType>(Ty));
331 Size = Layout->StructSize; Alignment = Layout->StructAlignment;
336 assert(0 && "Bad type for getTypeInfo!!!");
341 static inline void getTypeInfoPref(const Type *Ty, const TargetData *TD,
342 uint64_t &Size, unsigned char &Alignment) {
343 assert(Ty->isSized() && "Cannot getTypeInfoPref() on a type that is unsized!");
344 switch (Ty->getTypeID()) {
345 case Type::IntegerTyID: {
346 unsigned BitWidth = cast<IntegerType>(Ty)->getBitWidth();
348 Size = 1; Alignment = TD->getBytePrefAlignment();
349 } else if (BitWidth <= 16) {
350 Size = 2; Alignment = TD->getShortPrefAlignment();
351 } else if (BitWidth <= 32) {
352 Size = 4; Alignment = TD->getIntPrefAlignment();
353 } else if (BitWidth <= 64) {
354 Size = 8; Alignment = TD->getLongPrefAlignment();
356 assert(0 && "Integer types > 64 bits not supported.");
360 Size = 1; Alignment = TD->getBytePrefAlignment();
362 case Type::FloatTyID:
363 Size = 4; Alignment = TD->getFloatPrefAlignment();
365 case Type::DoubleTyID:
366 Size = 8; Alignment = TD->getDoublePrefAlignment();
368 case Type::LabelTyID:
369 case Type::PointerTyID:
370 Size = TD->getPointerSize(); Alignment = TD->getPointerPrefAlignment();
372 case Type::ArrayTyID: {
373 const ArrayType *ATy = cast<ArrayType>(Ty);
374 getTypeInfoPref(ATy->getElementType(), TD, Size, Alignment);
375 unsigned AlignedSize = (Size + Alignment - 1)/Alignment*Alignment;
376 Size = AlignedSize*ATy->getNumElements();
379 case Type::PackedTyID: {
380 const PackedType *PTy = cast<PackedType>(Ty);
381 getTypeInfoPref(PTy->getElementType(), TD, Size, Alignment);
382 unsigned AlignedSize = (Size + Alignment - 1)/Alignment*Alignment;
383 Size = AlignedSize*PTy->getNumElements();
384 // FIXME: The alignments of specific packed types are target dependent.
385 // For now, just set it to be equal to Size.
389 case Type::StructTyID: {
390 // Get the layout annotation... which is lazily created on demand;
391 // enforce minimum aggregate alignment.
392 const StructLayout *Layout = TD->getStructLayout(cast<StructType>(Ty));
393 Size = Layout->StructSize;
394 Alignment = std::max(Layout->StructAlignment,
395 (const unsigned int) TD->getAggMinPrefAlignment());
400 assert(0 && "Bad type for getTypeInfoPref!!!");
406 uint64_t TargetData::getTypeSize(const Type *Ty) const {
409 getTypeInfoABI(Ty, this, Size, Align);
413 uint64_t TargetData::getTypeSizeInBits(const Type *Ty) const {
415 return cast<IntegerType>(Ty)->getBitWidth();
419 getTypeInfoABI(Ty, this, Size, Align);
423 unsigned char TargetData::getTypeAlignmentABI(const Type *Ty) const {
426 getTypeInfoABI(Ty, this, Size, Align);
430 unsigned char TargetData::getTypeAlignmentPref(const Type *Ty) const {
433 getTypeInfoPref(Ty, this, Size, Align);
437 unsigned char TargetData::getPreferredTypeAlignmentShift(const Type *Ty) const {
438 unsigned Align = getTypeAlignmentPref(Ty);
439 assert(!(Align & (Align-1)) && "Alignment is not a power of two!");
440 return Log2_32(Align);
443 /// getIntPtrType - Return an unsigned integer type that is the same size or
444 /// greater to the host pointer size.
445 const Type *TargetData::getIntPtrType() const {
446 switch (getPointerSize()) {
447 default: assert(0 && "Unknown pointer size!");
448 case 2: return Type::Int16Ty;
449 case 4: return Type::Int32Ty;
450 case 8: return Type::Int64Ty;
455 uint64_t TargetData::getIndexedOffset(const Type *ptrTy,
456 const std::vector<Value*> &Idx) const {
457 const Type *Ty = ptrTy;
458 assert(isa<PointerType>(Ty) && "Illegal argument for getIndexedOffset()");
461 generic_gep_type_iterator<std::vector<Value*>::const_iterator>
462 TI = gep_type_begin(ptrTy, Idx.begin(), Idx.end());
463 for (unsigned CurIDX = 0; CurIDX != Idx.size(); ++CurIDX, ++TI) {
464 if (const StructType *STy = dyn_cast<StructType>(*TI)) {
465 assert(Idx[CurIDX]->getType() == Type::Int32Ty && "Illegal struct idx");
466 unsigned FieldNo = cast<ConstantInt>(Idx[CurIDX])->getZExtValue();
468 // Get structure layout information...
469 const StructLayout *Layout = getStructLayout(STy);
471 // Add in the offset, as calculated by the structure layout info...
472 assert(FieldNo < Layout->MemberOffsets.size() &&"FieldNo out of range!");
473 Result += Layout->MemberOffsets[FieldNo];
475 // Update Ty to refer to current element
476 Ty = STy->getElementType(FieldNo);
478 // Update Ty to refer to current element
479 Ty = cast<SequentialType>(Ty)->getElementType();
481 // Get the array index and the size of each array element.
482 int64_t arrayIdx = cast<ConstantInt>(Idx[CurIDX])->getSExtValue();
483 Result += arrayIdx * (int64_t)getTypeSize(Ty);
490 /// getPreferredAlignmentLog - Return the preferred alignment of the
491 /// specified global, returned in log form. This includes an explicitly
492 /// requested alignment (if the global has one).
493 unsigned TargetData::getPreferredAlignmentLog(const GlobalVariable *GV) const {
494 const Type *ElemType = GV->getType()->getElementType();
495 unsigned Alignment = getPreferredTypeAlignmentShift(ElemType);
496 if (GV->getAlignment() > (1U << Alignment))
497 Alignment = Log2_32(GV->getAlignment());
499 if (GV->hasInitializer()) {
501 // If the global is not external, see if it is large. If so, give it a
503 if (getTypeSize(ElemType) > 128)
504 Alignment = 4; // 16-byte alignment.