| //===-- TargetData.cpp - Data size & alignment routines --------------------==// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file 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/Constants.h" |
| #include "llvm/DerivedTypes.h" |
| #include "llvm/Module.h" |
| #include "llvm/Support/GetElementPtrTypeIterator.h" |
| #include "llvm/Support/MathExtras.h" |
| #include "llvm/Support/ManagedStatic.h" |
| #include "llvm/Support/ErrorHandling.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include "llvm/Support/Mutex.h" |
| #include "llvm/ADT/DenseMap.h" |
| #include <algorithm> |
| #include <cstdlib> |
| using namespace llvm; |
| |
| // Handle the Pass registration stuff necessary to use TargetData's. |
| |
| // Register the default SparcV9 implementation... |
| INITIALIZE_PASS(TargetData, "targetdata", "Target Data Layout", false, true) |
| char TargetData::ID = 0; |
| |
| //===----------------------------------------------------------------------===// |
| // Support for StructLayout |
| //===----------------------------------------------------------------------===// |
| |
| StructLayout::StructLayout(StructType *ST, const TargetData &TD) { |
| assert(!ST->isOpaque() && "Cannot get layout of opaque structs"); |
| StructAlignment = 0; |
| StructSize = 0; |
| NumElements = ST->getNumElements(); |
| |
| // Loop over each of the elements, placing them in memory. |
| for (unsigned i = 0, e = NumElements; i != e; ++i) { |
| Type *Ty = ST->getElementType(i); |
| unsigned TyAlign = ST->isPacked() ? 1 : TD.getABITypeAlignment(Ty); |
| |
| // Add padding if necessary to align the data element properly. |
| if ((StructSize & (TyAlign-1)) != 0) |
| StructSize = TargetData::RoundUpAlignment(StructSize, TyAlign); |
| |
| // Keep track of maximum alignment constraint. |
| StructAlignment = std::max(TyAlign, StructAlignment); |
| |
| MemberOffsets[i] = StructSize; |
| StructSize += TD.getTypeAllocSize(Ty); // 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-1)) != 0) |
| StructSize = TargetData::RoundUpAlignment(StructSize, StructAlignment); |
| } |
| |
| |
| /// getElementContainingOffset - Given a valid offset into the structure, |
| /// return the structure index that contains it. |
| unsigned StructLayout::getElementContainingOffset(uint64_t Offset) const { |
| const uint64_t *SI = |
| std::upper_bound(&MemberOffsets[0], &MemberOffsets[NumElements], Offset); |
| assert(SI != &MemberOffsets[0] && "Offset not in structure type!"); |
| --SI; |
| assert(*SI <= Offset && "upper_bound didn't work"); |
| assert((SI == &MemberOffsets[0] || *(SI-1) <= Offset) && |
| (SI+1 == &MemberOffsets[NumElements] || *(SI+1) > Offset) && |
| "Upper bound didn't work!"); |
| |
| // Multiple fields can have the same offset if any of them are zero sized. |
| // For example, in { i32, [0 x i32], i32 }, searching for offset 4 will stop |
| // at the i32 element, because it is the last element at that offset. This is |
| // the right one to return, because anything after it will have a higher |
| // offset, implying that this element is non-empty. |
| return SI-&MemberOffsets[0]; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // TargetAlignElem, TargetAlign support |
| //===----------------------------------------------------------------------===// |
| |
| TargetAlignElem |
| TargetAlignElem::get(AlignTypeEnum align_type, unsigned abi_align, |
| unsigned pref_align, uint32_t bit_width) { |
| assert(abi_align <= pref_align && "Preferred alignment worse than ABI!"); |
| TargetAlignElem retval; |
| retval.AlignType = align_type; |
| retval.ABIAlign = abi_align; |
| retval.PrefAlign = pref_align; |
| retval.TypeBitWidth = bit_width; |
| return retval; |
| } |
| |
| bool |
| TargetAlignElem::operator==(const TargetAlignElem &rhs) const { |
| return (AlignType == rhs.AlignType |
| && ABIAlign == rhs.ABIAlign |
| && PrefAlign == rhs.PrefAlign |
| && TypeBitWidth == rhs.TypeBitWidth); |
| } |
| |
| const TargetAlignElem TargetData::InvalidAlignmentElem = |
| TargetAlignElem::get((AlignTypeEnum) -1, 0, 0, 0); |
| |
| //===----------------------------------------------------------------------===// |
| // TargetData Class Implementation |
| //===----------------------------------------------------------------------===// |
| |
| /// getInt - Get an integer ignoring errors. |
| static unsigned getInt(StringRef R) { |
| unsigned Result = 0; |
| R.getAsInteger(10, Result); |
| return Result; |
| } |
| |
| void TargetData::init(StringRef Desc) { |
| initializeTargetDataPass(*PassRegistry::getPassRegistry()); |
| |
| LayoutMap = 0; |
| LittleEndian = false; |
| PointerMemSize = 8; |
| PointerABIAlign = 8; |
| PointerPrefAlign = PointerABIAlign; |
| StackNaturalAlign = 0; |
| |
| // Default alignments |
| setAlignment(INTEGER_ALIGN, 1, 1, 1); // i1 |
| setAlignment(INTEGER_ALIGN, 1, 1, 8); // i8 |
| setAlignment(INTEGER_ALIGN, 2, 2, 16); // i16 |
| setAlignment(INTEGER_ALIGN, 4, 4, 32); // i32 |
| setAlignment(INTEGER_ALIGN, 4, 8, 64); // i64 |
| setAlignment(FLOAT_ALIGN, 4, 4, 32); // float |
| setAlignment(FLOAT_ALIGN, 8, 8, 64); // double |
| setAlignment(VECTOR_ALIGN, 8, 8, 64); // v2i32, v1i64, ... |
| setAlignment(VECTOR_ALIGN, 16, 16, 128); // v16i8, v8i16, v4i32, ... |
| setAlignment(AGGREGATE_ALIGN, 0, 8, 0); // struct |
| |
| while (!Desc.empty()) { |
| std::pair<StringRef, StringRef> Split = Desc.split('-'); |
| StringRef Token = Split.first; |
| Desc = Split.second; |
| |
| if (Token.empty()) |
| continue; |
| |
| Split = Token.split(':'); |
| StringRef Specifier = Split.first; |
| Token = Split.second; |
| |
| assert(!Specifier.empty() && "Can't be empty here"); |
| |
| switch (Specifier[0]) { |
| case 'E': |
| LittleEndian = false; |
| break; |
| case 'e': |
| LittleEndian = true; |
| break; |
| case 'p': |
| Split = Token.split(':'); |
| PointerMemSize = getInt(Split.first) / 8; |
| Split = Split.second.split(':'); |
| PointerABIAlign = getInt(Split.first) / 8; |
| Split = Split.second.split(':'); |
| PointerPrefAlign = getInt(Split.first) / 8; |
| if (PointerPrefAlign == 0) |
| PointerPrefAlign = PointerABIAlign; |
| break; |
| case 'i': |
| case 'v': |
| case 'f': |
| case 'a': |
| case 's': { |
| AlignTypeEnum AlignType; |
| switch (Specifier[0]) { |
| default: |
| case 'i': AlignType = INTEGER_ALIGN; break; |
| case 'v': AlignType = VECTOR_ALIGN; break; |
| case 'f': AlignType = FLOAT_ALIGN; break; |
| case 'a': AlignType = AGGREGATE_ALIGN; break; |
| case 's': AlignType = STACK_ALIGN; break; |
| } |
| unsigned Size = getInt(Specifier.substr(1)); |
| Split = Token.split(':'); |
| unsigned ABIAlign = getInt(Split.first) / 8; |
| |
| Split = Split.second.split(':'); |
| unsigned PrefAlign = getInt(Split.first) / 8; |
| if (PrefAlign == 0) |
| PrefAlign = ABIAlign; |
| setAlignment(AlignType, ABIAlign, PrefAlign, Size); |
| break; |
| } |
| case 'n': // Native integer types. |
| Specifier = Specifier.substr(1); |
| do { |
| if (unsigned Width = getInt(Specifier)) |
| LegalIntWidths.push_back(Width); |
| Split = Token.split(':'); |
| Specifier = Split.first; |
| Token = Split.second; |
| } while (!Specifier.empty() || !Token.empty()); |
| break; |
| case 'S': // Stack natural alignment. |
| StackNaturalAlign = getInt(Specifier.substr(1)); |
| StackNaturalAlign /= 8; |
| // FIXME: Should we really be truncating these alingments and |
| // sizes silently? |
| break; |
| default: |
| break; |
| } |
| } |
| } |
| |
| /// Default ctor. |
| /// |
| /// @note This has to exist, because this is a pass, but it should never be |
| /// used. |
| TargetData::TargetData() : ImmutablePass(ID) { |
| report_fatal_error("Bad TargetData ctor used. " |
| "Tool did not specify a TargetData to use?"); |
| } |
| |
| TargetData::TargetData(const Module *M) |
| : ImmutablePass(ID) { |
| init(M->getDataLayout()); |
| } |
| |
| void |
| TargetData::setAlignment(AlignTypeEnum align_type, unsigned abi_align, |
| unsigned pref_align, uint32_t bit_width) { |
| assert(abi_align <= pref_align && "Preferred alignment worse than ABI!"); |
| for (unsigned i = 0, e = Alignments.size(); i != e; ++i) { |
| if (Alignments[i].AlignType == align_type && |
| Alignments[i].TypeBitWidth == bit_width) { |
| // Update the abi, preferred alignments. |
| Alignments[i].ABIAlign = abi_align; |
| Alignments[i].PrefAlign = pref_align; |
| return; |
| } |
| } |
| |
| Alignments.push_back(TargetAlignElem::get(align_type, abi_align, |
| pref_align, bit_width)); |
| } |
| |
| /// getAlignmentInfo - Return the alignment (either ABI if ABIInfo = true or |
| /// preferred if ABIInfo = false) the target wants for the specified datatype. |
| unsigned TargetData::getAlignmentInfo(AlignTypeEnum AlignType, |
| uint32_t BitWidth, bool ABIInfo, |
| Type *Ty) const { |
| // Check to see if we have an exact match and remember the best match we see. |
| int BestMatchIdx = -1; |
| int LargestInt = -1; |
| for (unsigned i = 0, e = Alignments.size(); i != e; ++i) { |
| if (Alignments[i].AlignType == AlignType && |
| Alignments[i].TypeBitWidth == BitWidth) |
| return ABIInfo ? Alignments[i].ABIAlign : Alignments[i].PrefAlign; |
| |
| // The best match so far depends on what we're looking for. |
| if (AlignType == INTEGER_ALIGN && |
| Alignments[i].AlignType == INTEGER_ALIGN) { |
| // The "best match" for integers is the smallest size that is larger than |
| // the BitWidth requested. |
| if (Alignments[i].TypeBitWidth > BitWidth && (BestMatchIdx == -1 || |
| Alignments[i].TypeBitWidth < Alignments[BestMatchIdx].TypeBitWidth)) |
| BestMatchIdx = i; |
| // However, if there isn't one that's larger, then we must use the |
| // largest one we have (see below) |
| if (LargestInt == -1 || |
| Alignments[i].TypeBitWidth > Alignments[LargestInt].TypeBitWidth) |
| LargestInt = i; |
| } |
| } |
| |
| // Okay, we didn't find an exact solution. Fall back here depending on what |
| // is being looked for. |
| if (BestMatchIdx == -1) { |
| // If we didn't find an integer alignment, fall back on most conservative. |
| if (AlignType == INTEGER_ALIGN) { |
| BestMatchIdx = LargestInt; |
| } else { |
| assert(AlignType == VECTOR_ALIGN && "Unknown alignment type!"); |
| |
| // By default, use natural alignment for vector types. This is consistent |
| // with what clang and llvm-gcc do. |
| unsigned Align = getTypeAllocSize(cast<VectorType>(Ty)->getElementType()); |
| Align *= cast<VectorType>(Ty)->getNumElements(); |
| // If the alignment is not a power of 2, round up to the next power of 2. |
| // This happens for non-power-of-2 length vectors. |
| if (Align & (Align-1)) |
| Align = llvm::NextPowerOf2(Align); |
| return Align; |
| } |
| } |
| |
| // Since we got a "best match" index, just return it. |
| return ABIInfo ? Alignments[BestMatchIdx].ABIAlign |
| : Alignments[BestMatchIdx].PrefAlign; |
| } |
| |
| namespace { |
| |
| class StructLayoutMap { |
| typedef DenseMap<StructType*, StructLayout*> LayoutInfoTy; |
| LayoutInfoTy LayoutInfo; |
| |
| public: |
| virtual ~StructLayoutMap() { |
| // Remove any layouts. |
| for (LayoutInfoTy::iterator I = LayoutInfo.begin(), E = LayoutInfo.end(); |
| I != E; ++I) { |
| StructLayout *Value = I->second; |
| Value->~StructLayout(); |
| free(Value); |
| } |
| } |
| |
| StructLayout *&operator[](StructType *STy) { |
| return LayoutInfo[STy]; |
| } |
| |
| // for debugging... |
| virtual void dump() const {} |
| }; |
| |
| } // end anonymous namespace |
| |
| TargetData::~TargetData() { |
| delete static_cast<StructLayoutMap*>(LayoutMap); |
| } |
| |
| const StructLayout *TargetData::getStructLayout(StructType *Ty) const { |
| if (!LayoutMap) |
| LayoutMap = new StructLayoutMap(); |
| |
| StructLayoutMap *STM = static_cast<StructLayoutMap*>(LayoutMap); |
| StructLayout *&SL = (*STM)[Ty]; |
| if (SL) return SL; |
| |
| // Otherwise, create the struct layout. Because it is variable length, we |
| // malloc it, then use placement new. |
| int NumElts = Ty->getNumElements(); |
| StructLayout *L = |
| (StructLayout *)malloc(sizeof(StructLayout)+(NumElts-1) * sizeof(uint64_t)); |
| |
| // Set SL before calling StructLayout's ctor. The ctor could cause other |
| // entries to be added to TheMap, invalidating our reference. |
| SL = L; |
| |
| new (L) StructLayout(Ty, *this); |
| |
| return L; |
| } |
| |
| std::string TargetData::getStringRepresentation() const { |
| std::string Result; |
| raw_string_ostream OS(Result); |
| |
| OS << (LittleEndian ? "e" : "E") |
| << "-p:" << PointerMemSize*8 << ':' << PointerABIAlign*8 |
| << ':' << PointerPrefAlign*8 |
| << "-S" << StackNaturalAlign*8; |
| |
| for (unsigned i = 0, e = Alignments.size(); i != e; ++i) { |
| const TargetAlignElem &AI = Alignments[i]; |
| OS << '-' << (char)AI.AlignType << AI.TypeBitWidth << ':' |
| << AI.ABIAlign*8 << ':' << AI.PrefAlign*8; |
| } |
| |
| if (!LegalIntWidths.empty()) { |
| OS << "-n" << (unsigned)LegalIntWidths[0]; |
| |
| for (unsigned i = 1, e = LegalIntWidths.size(); i != e; ++i) |
| OS << ':' << (unsigned)LegalIntWidths[i]; |
| } |
| return OS.str(); |
| } |
| |
| |
| uint64_t TargetData::getTypeSizeInBits(Type *Ty) const { |
| assert(Ty->isSized() && "Cannot getTypeInfo() on a type that is unsized!"); |
| switch (Ty->getTypeID()) { |
| case Type::LabelTyID: |
| case Type::PointerTyID: |
| return getPointerSizeInBits(); |
| case Type::ArrayTyID: { |
| ArrayType *ATy = cast<ArrayType>(Ty); |
| return getTypeAllocSizeInBits(ATy->getElementType())*ATy->getNumElements(); |
| } |
| case Type::StructTyID: |
| // Get the layout annotation... which is lazily created on demand. |
| return getStructLayout(cast<StructType>(Ty))->getSizeInBits(); |
| case Type::IntegerTyID: |
| return cast<IntegerType>(Ty)->getBitWidth(); |
| case Type::VoidTyID: |
| return 8; |
| case Type::FloatTyID: |
| return 32; |
| case Type::DoubleTyID: |
| case Type::X86_MMXTyID: |
| return 64; |
| case Type::PPC_FP128TyID: |
| case Type::FP128TyID: |
| return 128; |
| // In memory objects this is always aligned to a higher boundary, but |
| // only 80 bits contain information. |
| case Type::X86_FP80TyID: |
| return 80; |
| case Type::VectorTyID: |
| return cast<VectorType>(Ty)->getBitWidth(); |
| default: |
| llvm_unreachable("TargetData::getTypeSizeInBits(): Unsupported type"); |
| break; |
| } |
| return 0; |
| } |
| |
| /*! |
| \param abi_or_pref Flag that determines which alignment is returned. true |
| returns the ABI alignment, false returns the preferred alignment. |
| \param Ty The underlying type for which alignment is determined. |
| |
| Get the ABI (\a abi_or_pref == true) or preferred alignment (\a abi_or_pref |
| == false) for the requested type \a Ty. |
| */ |
| unsigned TargetData::getAlignment(Type *Ty, bool abi_or_pref) const { |
| int AlignType = -1; |
| |
| assert(Ty->isSized() && "Cannot getTypeInfo() on a type that is unsized!"); |
| switch (Ty->getTypeID()) { |
| // Early escape for the non-numeric types. |
| case Type::LabelTyID: |
| case Type::PointerTyID: |
| return (abi_or_pref |
| ? getPointerABIAlignment() |
| : getPointerPrefAlignment()); |
| case Type::ArrayTyID: |
| return getAlignment(cast<ArrayType>(Ty)->getElementType(), abi_or_pref); |
| |
| case Type::StructTyID: { |
| // Packed structure types always have an ABI alignment of one. |
| if (cast<StructType>(Ty)->isPacked() && abi_or_pref) |
| return 1; |
| |
| // Get the layout annotation... which is lazily created on demand. |
| const StructLayout *Layout = getStructLayout(cast<StructType>(Ty)); |
| unsigned Align = getAlignmentInfo(AGGREGATE_ALIGN, 0, abi_or_pref, Ty); |
| return std::max(Align, Layout->getAlignment()); |
| } |
| case Type::IntegerTyID: |
| case Type::VoidTyID: |
| AlignType = INTEGER_ALIGN; |
| break; |
| case Type::FloatTyID: |
| case Type::DoubleTyID: |
| // PPC_FP128TyID and FP128TyID have different data contents, but the |
| // same size and alignment, so they look the same here. |
| case Type::PPC_FP128TyID: |
| case Type::FP128TyID: |
| case Type::X86_FP80TyID: |
| AlignType = FLOAT_ALIGN; |
| break; |
| case Type::X86_MMXTyID: |
| case Type::VectorTyID: |
| AlignType = VECTOR_ALIGN; |
| break; |
| default: |
| llvm_unreachable("Bad type for getAlignment!!!"); |
| break; |
| } |
| |
| return getAlignmentInfo((AlignTypeEnum)AlignType, getTypeSizeInBits(Ty), |
| abi_or_pref, Ty); |
| } |
| |
| unsigned TargetData::getABITypeAlignment(Type *Ty) const { |
| return getAlignment(Ty, true); |
| } |
| |
| /// getABIIntegerTypeAlignment - Return the minimum ABI-required alignment for |
| /// an integer type of the specified bitwidth. |
| unsigned TargetData::getABIIntegerTypeAlignment(unsigned BitWidth) const { |
| return getAlignmentInfo(INTEGER_ALIGN, BitWidth, true, 0); |
| } |
| |
| |
| unsigned TargetData::getCallFrameTypeAlignment(Type *Ty) const { |
| for (unsigned i = 0, e = Alignments.size(); i != e; ++i) |
| if (Alignments[i].AlignType == STACK_ALIGN) |
| return Alignments[i].ABIAlign; |
| |
| return getABITypeAlignment(Ty); |
| } |
| |
| unsigned TargetData::getPrefTypeAlignment(Type *Ty) const { |
| return getAlignment(Ty, false); |
| } |
| |
| unsigned TargetData::getPreferredTypeAlignmentShift(Type *Ty) const { |
| unsigned Align = getPrefTypeAlignment(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. |
| IntegerType *TargetData::getIntPtrType(LLVMContext &C) const { |
| return IntegerType::get(C, getPointerSizeInBits()); |
| } |
| |
| |
| uint64_t TargetData::getIndexedOffset(Type *ptrTy, |
| ArrayRef<Value *> Indices) const { |
| Type *Ty = ptrTy; |
| assert(Ty->isPointerTy() && "Illegal argument for getIndexedOffset()"); |
| uint64_t Result = 0; |
| |
| generic_gep_type_iterator<Value* const*> |
| TI = gep_type_begin(ptrTy, Indices); |
| for (unsigned CurIDX = 0, EndIDX = Indices.size(); CurIDX != EndIDX; |
| ++CurIDX, ++TI) { |
| if (StructType *STy = dyn_cast<StructType>(*TI)) { |
| assert(Indices[CurIDX]->getType() == |
| Type::getInt32Ty(ptrTy->getContext()) && |
| "Illegal struct idx"); |
| unsigned FieldNo = cast<ConstantInt>(Indices[CurIDX])->getZExtValue(); |
| |
| // Get structure layout information... |
| const StructLayout *Layout = getStructLayout(STy); |
| |
| // Add in the offset, as calculated by the structure layout info... |
| Result += Layout->getElementOffset(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. |
| if (int64_t arrayIdx = cast<ConstantInt>(Indices[CurIDX])->getSExtValue()) |
| Result += (uint64_t)arrayIdx * getTypeAllocSize(Ty); |
| } |
| } |
| |
| return Result; |
| } |
| |
| /// getPreferredAlignment - Return the preferred alignment of the specified |
| /// global. This includes an explicitly requested alignment (if the global |
| /// has one). |
| unsigned TargetData::getPreferredAlignment(const GlobalVariable *GV) const { |
| Type *ElemType = GV->getType()->getElementType(); |
| unsigned Alignment = getPrefTypeAlignment(ElemType); |
| unsigned GVAlignment = GV->getAlignment(); |
| if (GVAlignment >= Alignment) { |
| Alignment = GVAlignment; |
| } else if (GVAlignment != 0) { |
| Alignment = std::max(GVAlignment, getABITypeAlignment(ElemType)); |
| } |
| |
| if (GV->hasInitializer() && GVAlignment == 0) { |
| if (Alignment < 16) { |
| // If the global is not external, see if it is large. If so, give it a |
| // larger alignment. |
| if (getTypeSizeInBits(ElemType) > 128) |
| Alignment = 16; // 16-byte alignment. |
| } |
| } |
| return Alignment; |
| } |
| |
| /// getPreferredAlignmentLog - Return the preferred alignment of the |
| /// specified global, returned in log form. This includes an explicitly |
| /// requested alignment (if the global has one). |
| unsigned TargetData::getPreferredAlignmentLog(const GlobalVariable *GV) const { |
| return Log2_32(getPreferredAlignment(GV)); |
| } |