From f854bfc7b7fd14c09a71bd84cb56bcf647664e55 Mon Sep 17 00:00:00 2001 From: Micah Villmow Date: Thu, 4 Oct 2012 20:06:07 +0000 Subject: [PATCH] (no commit message) llvm-svn: 165243 --- llvm/lib/VMCore/DataLayout.cpp | 665 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 665 insertions(+) create mode 100644 llvm/lib/VMCore/DataLayout.cpp diff --git a/llvm/lib/VMCore/DataLayout.cpp b/llvm/lib/VMCore/DataLayout.cpp new file mode 100644 index 0000000..0040147 --- /dev/null +++ b/llvm/lib/VMCore/DataLayout.cpp @@ -0,0 +1,665 @@ +//===-- 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 +#include +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 = { (AlignTypeEnum)0xFF, 0, 0, 0 }; + +//===----------------------------------------------------------------------===// +// TargetData Class Implementation +//===----------------------------------------------------------------------===// + +/// getInt - Get an integer ignoring errors. +static int getInt(StringRef R) { + int Result = 0; + R.getAsInteger(10, Result); + return Result; +} + +void TargetData::init() { + 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, 2, 2, 16); // half + setAlignment(FLOAT_ALIGN, 4, 4, 32); // float + setAlignment(FLOAT_ALIGN, 8, 8, 64); // double + setAlignment(FLOAT_ALIGN, 16, 16, 128); // ppcf128, quad, ... + setAlignment(VECTOR_ALIGN, 8, 8, 64); // v2i32, v1i64, ... + setAlignment(VECTOR_ALIGN, 16, 16, 128); // v16i8, v8i16, v4i32, ... + setAlignment(AGGREGATE_ALIGN, 0, 8, 0); // struct +} + +std::string TargetData::parseSpecifier(StringRef Desc, TargetData *td) { + + if (td) + td->init(); + + while (!Desc.empty()) { + std::pair 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': + if (td) + td->LittleEndian = false; + break; + case 'e': + if (td) + td->LittleEndian = true; + break; + case 'p': { + // Pointer size. + Split = Token.split(':'); + int PointerMemSizeBits = getInt(Split.first); + if (PointerMemSizeBits < 0 || PointerMemSizeBits % 8 != 0) + return "invalid pointer size, must be a positive 8-bit multiple"; + if (td) + td->PointerMemSize = PointerMemSizeBits / 8; + + // Pointer ABI alignment. + Split = Split.second.split(':'); + int PointerABIAlignBits = getInt(Split.first); + if (PointerABIAlignBits < 0 || PointerABIAlignBits % 8 != 0) { + return "invalid pointer ABI alignment, " + "must be a positive 8-bit multiple"; + } + if (td) + td->PointerABIAlign = PointerABIAlignBits / 8; + + // Pointer preferred alignment. + Split = Split.second.split(':'); + int PointerPrefAlignBits = getInt(Split.first); + if (PointerPrefAlignBits < 0 || PointerPrefAlignBits % 8 != 0) { + return "invalid pointer preferred alignment, " + "must be a positive 8-bit multiple"; + } + if (td) { + td->PointerPrefAlign = PointerPrefAlignBits / 8; + if (td->PointerPrefAlign == 0) + td->PointerPrefAlign = td->PointerABIAlign; + } + break; + } + case 'i': + case 'v': + case 'f': + case 'a': + case 's': { + AlignTypeEnum AlignType; + char field = Specifier[0]; + switch (field) { + 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; + } + int Size = getInt(Specifier.substr(1)); + if (Size < 0) { + return std::string("invalid ") + field + "-size field, " + "must be positive"; + } + + Split = Token.split(':'); + int ABIAlignBits = getInt(Split.first); + if (ABIAlignBits < 0 || ABIAlignBits % 8 != 0) { + return std::string("invalid ") + field +"-abi-alignment field, " + "must be a positive 8-bit multiple"; + } + unsigned ABIAlign = ABIAlignBits / 8; + + Split = Split.second.split(':'); + + int PrefAlignBits = getInt(Split.first); + if (PrefAlignBits < 0 || PrefAlignBits % 8 != 0) { + return std::string("invalid ") + field +"-preferred-alignment field, " + "must be a positive 8-bit multiple"; + } + unsigned PrefAlign = PrefAlignBits / 8; + if (PrefAlign == 0) + PrefAlign = ABIAlign; + + if (td) + td->setAlignment(AlignType, ABIAlign, PrefAlign, Size); + break; + } + case 'n': // Native integer types. + Specifier = Specifier.substr(1); + do { + int Width = getInt(Specifier); + if (Width <= 0) { + return std::string("invalid native integer size \'") + Specifier.str() + + "\', must be a positive integer."; + } + if (td && Width != 0) + td->LegalIntWidths.push_back(Width); + Split = Token.split(':'); + Specifier = Split.first; + Token = Split.second; + } while (!Specifier.empty() || !Token.empty()); + break; + case 'S': { // Stack natural alignment. + int StackNaturalAlignBits = getInt(Specifier.substr(1)); + if (StackNaturalAlignBits < 0 || StackNaturalAlignBits % 8 != 0) { + return "invalid natural stack alignment (S-field), " + "must be a positive 8-bit multiple"; + } + if (td) + td->StackNaturalAlign = StackNaturalAlignBits / 8; + break; + } + default: + break; + } + } + + return ""; +} + +/// 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) { + std::string errMsg = parseSpecifier(M->getDataLayout(), this); + assert(errMsg == "" && "Module M has malformed target data layout string."); + (void)errMsg; +} + +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!"); + assert(pref_align < (1 << 16) && "Alignment doesn't fit in bitfield"); + assert(bit_width < (1 << 24) && "Bit width doesn't fit in bitfield"); + 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(Ty)->getElementType()); + Align *= cast(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 = 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 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(LayoutMap); +} + +const StructLayout *TargetData::getStructLayout(StructType *Ty) const { + if (!LayoutMap) + LayoutMap = new StructLayoutMap(); + + StructLayoutMap *STM = static_cast(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(Ty); + return getTypeAllocSizeInBits(ATy->getElementType())*ATy->getNumElements(); + } + case Type::StructTyID: + // Get the layout annotation... which is lazily created on demand. + return getStructLayout(cast(Ty))->getSizeInBits(); + case Type::IntegerTyID: + return cast(Ty)->getBitWidth(); + case Type::VoidTyID: + return 8; + case Type::HalfTyID: + return 16; + 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(Ty)->getBitWidth(); + default: + llvm_unreachable("TargetData::getTypeSizeInBits(): Unsupported type"); + } +} + +/*! + \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(Ty)->getElementType(), abi_or_pref); + + case Type::StructTyID: { + // Packed structure types always have an ABI alignment of one. + if (cast(Ty)->isPacked() && abi_or_pref) + return 1; + + // Get the layout annotation... which is lazily created on demand. + const StructLayout *Layout = getStructLayout(cast(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::HalfTyID: + 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!!!"); + } + + 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 Indices) const { + Type *Ty = ptrTy; + assert(Ty->isPointerTy() && "Illegal argument for getIndexedOffset()"); + uint64_t Result = 0; + + generic_gep_type_iterator + TI = gep_type_begin(ptrTy, Indices); + for (unsigned CurIDX = 0, EndIDX = Indices.size(); CurIDX != EndIDX; + ++CurIDX, ++TI) { + if (StructType *STy = dyn_cast(*TI)) { + assert(Indices[CurIDX]->getType() == + Type::getInt32Ty(ptrTy->getContext()) && + "Illegal struct idx"); + unsigned FieldNo = cast(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(Ty)->getElementType(); + + // Get the array index and the size of each array element. + if (int64_t arrayIdx = cast(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)); +} -- 2.7.4