================ @@ -0,0 +1,1458 @@ +//===- X86.cpp ------------------------------------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#include "llvm/ABI/ABIFunctionInfo.h" +#include "llvm/ABI/ABIInfo.h" +#include "llvm/ABI/TargetCodegenInfo.h" +#include "llvm/ABI/Types.h" +#include "llvm/ADT/DenseMap.h" +#include "llvm/IR/Type.h" +#include "llvm/Support/Alignment.h" +#include "llvm/Support/Casting.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/MathExtras.h" +#include "llvm/Support/TypeSize.h" +#include "llvm/TargetParser/Triple.h" +#include <algorithm> +#include <cassert> +#include <cstdint> + +namespace llvm { +namespace abi { + +static unsigned getNativeVectorSizeForAVXABI(X86AVXABILevel AVXLevel) { + switch (AVXLevel) { + case X86AVXABILevel::AVX512: + return 512; + case X86AVXABILevel::AVX: + return 256; + case X86AVXABILevel::None: + return 128; + } + llvm_unreachable("Unknown AVXLevel"); +} + +class X86_64ABIInfo : public ABIInfo { +public: + enum Class { + Integer = 0, + SSE, + SSEUp, + X87, + X87UP, + Complex_X87, + NoClass, + Memory + }; + +private: + TypeBuilder &TB; + X86AVXABILevel AVXLevel; + bool Has64BitPointers; + const llvm::Triple &TargetTriple; + + static Class merge(Class Accum, Class Field); + + void postMerge(unsigned AggregateSize, Class &Lo, Class &Hi) const; + + void classify(const Type *T, uint64_t OffsetBase, Class &Lo, Class &Hi, + bool IsNamedArg, bool IsRegCall = false) const; + + const Type *getIntegerTypeAtOffset(const Type *IRType, unsigned IROffset, + const Type *SourceTy, + unsigned SourceOffset, + bool InMemory = false) const; + + const Type *getSSETypeAtOffset(const Type *ABIType, unsigned ABIOffset, + const Type *SourceTy, + unsigned SourceOffset) const; + bool isIllegalVectorType(const Type *Ty) const; + bool containsMatrixField(const RecordType *RT) const; + + void computeInfo(ABIFunctionInfo &FI) const override; + ABIArgInfo getIndirectReturnResult(const Type *Ty) const; + const Type *getFPTypeAtOffset(const Type *Ty, unsigned Offset) const; + + const Type *isSingleElementStruct(const Type *Ty) const; + const Type *getByteVectorType(const Type *Ty) const; + + const Type *createPairType(const Type *Lo, const Type *Hi) const; + ABIArgInfo getIndirectResult(const Type *Ty, unsigned FreeIntRegs) const; + + ABIArgInfo classifyReturnType(const Type *RetTy) const; + const char *getClassName(Class C) const; + + ABIArgInfo classifyArgumentType(const Type *Ty, unsigned FreeIntRegs, + unsigned &NeededInt, unsigned &NeededSse, + bool IsNamedArg, + bool IsRegCall = false) const; + const Type *useFirstFieldIfTransparentUnion(const Type *Ty) const; + +public: + X86_64ABIInfo(TypeBuilder &TypeBuilder, const Triple &Triple, + X86AVXABILevel AVXABILevel, bool Has64BitPtrs, + const ABICompatInfo &Compat) + : ABIInfo(Compat), TB(TypeBuilder), AVXLevel(AVXABILevel), + Has64BitPointers(Has64BitPtrs), TargetTriple(Triple) {} + + bool has64BitPointers() const { return Has64BitPointers; } +}; + +// Gets the "best" type to represent the union. +static const Type *reduceUnionForX8664(const RecordType *UnionType, + TypeBuilder &TB) { + assert(UnionType->isUnion() && "Expected union type"); + + ArrayRef<FieldInfo> Fields = UnionType->getFields(); + if (Fields.empty()) { + return nullptr; + } + + const Type *StorageType = nullptr; + + for (const auto &Field : Fields) { + if (Field.IsBitField && Field.IsUnnamedBitfield && + Field.BitFieldWidth == 0) { + continue; + } + + const Type *FieldType = Field.FieldType; + + if (UnionType->isTransparentUnion() && !StorageType) { + StorageType = FieldType; + break; + } + + if (!StorageType || + FieldType->getAlignment() > StorageType->getAlignment() || + (FieldType->getAlignment() == StorageType->getAlignment() && + TypeSize::isKnownGT(FieldType->getSizeInBits(), + StorageType->getSizeInBits()))) { + StorageType = FieldType; + } + } + return StorageType; +} + +void X86_64ABIInfo::postMerge(unsigned AggregateSize, Class &Lo, + Class &Hi) const { + // AMD64-ABI 3.2.3p2: Rule 5. Then a post merger cleanup is done: + // + // (a) If one of the classes is Memory, the whole argument is passed in + // memory. + // + // (b) If X87UP is not preceded by X87, the whole argument is passed in + // memory. + // + // (c) If the size of the aggregate exceeds two eightbytes and the first + // eightbyte isn't SSE or any other eightbyte isn't SSEUP, the whole + // argument is passed in memory. NOTE: This is necessary to keep the + // ABI working for processors that don't support the __m256 type. + // + // (d) If SSEUP is not preceded by SSE or SSEUP, it is converted to SSE. + // + // Some of these are enforced by the merging logic. Others can arise + // only with unions; for example: + // union { _Complex double; unsigned; } + // + // Note that clauses (b) and (c) were added in 0.98. + + if (Hi == Memory) + Lo = Memory; + if (Hi == X87UP && Lo != X87 && getABICompatInfo().Flags.HonorsRevision98) + Lo = Memory; + if (AggregateSize > 128 && (Lo != SSE || Hi != SSEUp)) + Lo = Memory; + if (Hi == SSEUp && Lo != SSE) + Hi = SSE; +} +X86_64ABIInfo::Class X86_64ABIInfo::merge(Class Accum, Class Field) { + // AMD64-ABI 3.2.3p2: Rule 4. Each field of an object is + // classified recursively so that always two fields are + // considered. The resulting class is calculated according to + // the classes of the fields in the eightbyte: + // + // (a) If both classes are equal, this is the resulting class. + // + // (b) If one of the classes is NO_CLASS, the resulting class is + // the other class. + // + // (c) If one of the classes is MEMORY, the result is the MEMORY + // class. + // + // (d) If one of the classes is INTEGER, the result is the + // INTEGER. + // + // (e) If one of the classes is X87, X87UP, COMPLEX_X87 class, + // MEMORY is used as class. + // + // (f) Otherwise class SSE is used. + + // Accum should never be memory (we should have returned) or + // ComplexX87 (because this cannot be passed in a structure). + assert((Accum != Memory && Accum != Complex_X87) && + "Invalid accumulated classification during merge."); + + if (Accum == Field || Field == NoClass) + return Accum; + if (Accum == NoClass) + return Field; + if (Field == Memory) + return Memory; + if (Accum == Integer || Field == Integer) + return Integer; + if (Field == X87 || Field == X87UP || Field == Complex_X87 || Accum == X87 || + Accum == X87UP) + return Memory; + + return SSE; +} + +bool X86_64ABIInfo::containsMatrixField(const RecordType *RT) const { + for (const auto &Field : RT->getFields()) { + const Type *FieldType = Field.FieldType; + + if (const auto *AT = dyn_cast<ArrayType>(FieldType)) + return AT->isMatrixType(); + + if (const auto *NestedRT = dyn_cast<RecordType>(FieldType)) + return containsMatrixField(NestedRT); + } + return false; +} + +void X86_64ABIInfo::classify(const Type *T, uint64_t OffsetBase, Class &Lo, + Class &Hi, bool IsNamedArg, bool IsRegCall) const { + Lo = Hi = NoClass; + Class &Current = OffsetBase < 64 ? Lo : Hi; + Current = Memory; + + if (T->isVoid()) { + Current = NoClass; + return; + } + + if (const auto *IT = dyn_cast<IntegerType>(T)) { + auto BitWidth = IT->getSizeInBits().getFixedValue(); + + if (BitWidth == 128 || + (IT->isBitInt() && BitWidth > 64 && BitWidth <= 128)) { + Lo = Integer; + Hi = Integer; + } else if (BitWidth <= 64) + Current = Integer; + + return; + } + + if (const auto *FT = dyn_cast<FloatType>(T)) { + const auto *FltSem = FT->getSemantics(); + + if (FltSem == &llvm::APFloat::IEEEsingle() || + FltSem == &llvm::APFloat::IEEEdouble() || + FltSem == &llvm::APFloat::IEEEhalf() || + FltSem == &llvm::APFloat::BFloat()) { + Current = SSE; + } else if (FltSem == &llvm::APFloat::IEEEquad()) { + Lo = SSE; + Hi = SSEUp; + } else if (FltSem == &llvm::APFloat::x87DoubleExtended()) { + Lo = X87; + Hi = X87UP; + } else + Current = SSE; + return; + } + if (T->isPointer()) { + Current = Integer; + return; + } + + if (const auto *MPT = dyn_cast<MemberPointerType>(T)) { + if (MPT->isFunctionPointer()) { + if (Has64BitPointers) { + Lo = Hi = Integer; + } else { + uint64_t EbFuncPtr = OffsetBase / 64; + uint64_t EbThisAdj = (OffsetBase + 64 - 1) / 64; + if (EbFuncPtr != EbThisAdj) { + Lo = Hi = Integer; + } else + Current = Integer; + } + } else + Current = Integer; + return; + } + + if (const auto *VT = dyn_cast<VectorType>(T)) { + auto Size = VT->getSizeInBits().getFixedValue(); + const Type *ElementType = VT->getElementType(); + + if (Size == 1 || Size == 8 || Size == 16 || Size == 32) { + // gcc passes the following as integer: + // 4 bytes - <4 x char>, <2 x short>, <1 x int>, <1 x float> + // 2 bytes - <2 x char>, <1 x short> + // 1 byte - <1 x char> + Current = Integer; + // If this type crosses an eightbyte boundary, it should be + // split. + uint64_t EbLo = (OffsetBase) / 64; + uint64_t EbHi = (OffsetBase + Size - 1) / 64; + if (EbLo != EbHi) + Hi = Lo; + } else if (Size == 64) { + if (const auto *FT = dyn_cast<FloatType>(ElementType)) { + // gcc passes <1 x double> in memory. :( + if (FT->getSemantics() == &llvm::APFloat::IEEEdouble()) + return; + } + + // gcc passes <1 x long long> as SSE but clang used to unconditionally + // pass them as integer. For platforms where clang is the de facto + // platform compiler, we must continue to use integer. + if (const auto *IT = dyn_cast<IntegerType>(ElementType)) { + uint64_t ElemBits = IT->getSizeInBits().getFixedValue(); + if (!getABICompatInfo().Flags.ClassifyIntegerMMXAsSSE && + (ElemBits == 64 || ElemBits == 32)) { + Current = Integer; + } else + Current = SSE; + } else + Current = SSE; + // If this type crosses an eightbyte boundary, it should be + // split. + if (OffsetBase && OffsetBase != 64) + Hi = Lo; + } else if (Size == 128 || + (IsNamedArg && Size <= getNativeVectorSizeForAVXABI(AVXLevel))) { + if (const auto *IT = dyn_cast<IntegerType>(ElementType)) { + uint64_t ElemBits = IT->getSizeInBits().getFixedValue(); + // gcc passes 256 and 512 bit <X x __int128> vectors in memory. :( + if (getABICompatInfo().Flags.PassInt128VectorsInMem && Size != 128 && + ElemBits == 128) + return; + } + + // Arguments of 256-bits are split into four eightbyte chunks. The + // least significant one belongs to class SSE and all the others to class + // SSEUP. The original Lo and Hi design considers that types can't be + // greater than 128-bits, so a 64-bit split in Hi and Lo makes sense. + // This design isn't correct for 256-bits, but since there're no cases + // where the upper parts would need to be inspected, avoid adding + // complexity and just consider Hi to match the 64-256 part. + // + // Note that per 3.5.7 of AMD64-ABI, 256-bit args are only passed in + // registers if they are "named", i.e. not part of the "..." of a + // variadic function. + // + // Similarly, per 3.2.3. of the AVX512 draft, 512-bits ("named") args are + // split into eight eightbyte chunks, one SSE and seven SSEUP. + Lo = SSE; + Hi = SSEUp; + } + return; + } + + if (const auto *CT = dyn_cast<ComplexType>(T)) { + const Type *ElementType = CT->getElementType(); + uint64_t Size = T->getSizeInBits().getFixedValue(); + + if (isa<IntegerType>(ElementType)) { + if (Size <= 64) + Current = Integer; + else if (Size <= 128) + Lo = Hi = Integer; + } else if (const auto *EFT = dyn_cast<FloatType>(ElementType)) { + const auto *FltSem = EFT->getSemantics(); + if (FltSem == &llvm::APFloat::IEEEhalf() || + FltSem == &llvm::APFloat::IEEEsingle() || + FltSem == &llvm::APFloat::BFloat()) + Current = SSE; + else if (FltSem == &llvm::APFloat::IEEEquad()) + Current = Memory; + else if (FltSem == &llvm::APFloat::x87DoubleExtended()) + Current = Complex_X87; + else if (FltSem == &llvm::APFloat::IEEEdouble()) + Lo = Hi = SSE; + else + llvm_unreachable("Unexpected long double representation!"); + } + + uint64_t ElementSize = ElementType->getSizeInBits().getFixedValue(); + // If this complex type crosses an eightbyte boundary then it + // should be split. + uint64_t EbReal = OffsetBase / 64; + uint64_t EbImag = (OffsetBase + ElementSize) / 64; + if (Hi == NoClass && EbReal != EbImag) + Hi = Lo; + + return; + } + + if (const auto *AT = dyn_cast<ArrayType>(T)) { + uint64_t Size = AT->getSizeInBits().getFixedValue(); + + if (!IsRegCall && Size > 512) + return; + + const Type *ElementType = AT->getElementType(); + uint64_t ElemAlign = ElementType->getAlignment().value() * 8; + if (OffsetBase % ElemAlign) + return; + + Current = NoClass; + uint64_t EltSize = ElementType->getSizeInBits().getFixedValue(); + uint64_t ArraySize = AT->getNumElements(); + + if (Size > 128 && + (Size != EltSize || Size > getNativeVectorSizeForAVXABI(AVXLevel))) + return; + + for (uint64_t I = 0, Offset = OffsetBase; I < ArraySize; + ++I, Offset += EltSize) { + Class FieldLo, FieldHi; + classify(ElementType, Offset, FieldLo, FieldHi, IsNamedArg); + Lo = merge(Lo, FieldLo); + Hi = merge(Hi, FieldHi); + if (Lo == Memory || Hi == Memory) + break; + } + postMerge(Size, Lo, Hi); + assert((Hi != SSEUp || Lo == SSE) && "Invalid SSEUp array classification."); + return; + } + if (const auto *RT = dyn_cast<RecordType>(T)) { + uint64_t Size = RT->getSizeInBits().getFixedValue(); + + if (containsMatrixField(RT)) { + Lo = Memory; + return; + } + + // AMD64-ABI 3.2.3p2: Rule 1. If the size of an object is larger + // than eight eightbytes, ..., it has class MEMORY. + if (Size > 512) + return; + + // AMD64-ABI 3.2.3p2: Rule 2. If a C++ object has either a non-trivial + // copy constructor or a non-trivial destructor, it is passed by invisible + // reference. + if (getRecordArgABI(RT, RT->isCXXRecord())) + return; + + // Assume variable sized types are passed in memory. + if (RT->hasFlexibleArrayMember()) + return; + + // Reset Lo class, this will be recomputed. + Current = NoClass; + + // If this is a C++ record, classify the bases first. + if (RT->isCXXRecord()) { + for (const auto &Base : RT->getBaseClasses()) { + + // Classify this field. + // + // AMD64-ABI 3.2.3p2: Rule 3. If the size of the aggregate exceeds a + // single eightbyte, each is classified separately. Each eightbyte gets + // initialized to class NO_CLASS. + Class FieldLo, FieldHi; + uint64_t Offset = OffsetBase + Base.OffsetInBits; + classify(Base.FieldType, Offset, FieldLo, FieldHi, IsNamedArg); + Lo = merge(Lo, FieldLo); + Hi = merge(Hi, FieldHi); + + if (getABICompatInfo().Flags.ReturnCXXRecordGreaterThan128InMem && + (Size > 128 && + (Size != Base.FieldType->getSizeInBits().getFixedValue() || + Size > getNativeVectorSizeForAVXABI(AVXLevel)))) { + Lo = Memory; + postMerge(Size, Lo, Hi); + return; + } + + if (Lo == Memory || Hi == Memory) { + postMerge(Size, Lo, Hi); + return; + } + } + } + + // Classify the fields one at a time, merging the results. + + bool IsUnion = RT->isUnion() && !getABICompatInfo().Flags.Clang11Compat; + for (const auto &Field : RT->getFields()) { + uint64_t Offset = OffsetBase + Field.OffsetInBits; + bool BitField = Field.IsBitField; + + if (BitField && Field.IsUnnamedBitfield) + continue; + + if (Size > 128 && + ((!IsUnion && + Size != Field.FieldType->getSizeInBits().getFixedValue()) || + Size > getNativeVectorSizeForAVXABI(AVXLevel))) { + Lo = Memory; + postMerge(Size, Lo, Hi); + return; + } + + bool IsInMemory = Offset % (Field.FieldType->getAlignment().value() * 8); + if (!BitField && IsInMemory) { + Lo = Memory; + postMerge(Size, Lo, Hi); + return; + } + + Class FieldLo, FieldHi; + + if (BitField) { + uint64_t BitFieldSize = Field.BitFieldWidth; + uint64_t EbLo = Offset / 64; + uint64_t EbHi = (Offset + BitFieldSize - 1) / 64; + + if (EbLo) { + assert(EbHi == EbLo && "Invalid classification, type > 16 bytes."); + FieldLo = NoClass; + FieldHi = Integer; + } else { + FieldLo = Integer; + FieldHi = EbHi ? Integer : NoClass; + } + } else + classify(Field.FieldType, Offset, FieldLo, FieldHi, IsNamedArg); + + Lo = merge(Lo, FieldLo); + Hi = merge(Hi, FieldHi); + if (Lo == Memory || Hi == Memory) + break; + } + postMerge(Size, Lo, Hi); + return; + } + + Lo = Memory; + Hi = NoClass; +} + +const Type * +X86_64ABIInfo::useFirstFieldIfTransparentUnion(const Type *Ty) const { + if (const auto *RT = dyn_cast<RecordType>(Ty)) { + if (RT->isUnion() && RT->isTransparentUnion()) { + auto Fields = RT->getFields(); + assert(!Fields.empty() && "sema created an empty transparent union"); + return Fields.front().FieldType; + } + } + return Ty; +} + +ABIArgInfo +X86_64ABIInfo::classifyArgumentType(const Type *Ty, unsigned FreeIntRegs, + unsigned &NeededInt, unsigned &NeededSSE, + bool IsNamedArg, bool IsRegCall) const { + + Ty = useFirstFieldIfTransparentUnion(Ty); + + X86_64ABIInfo::Class Lo, Hi; + classify(Ty, 0, Lo, Hi, IsNamedArg, IsRegCall); + + // Check some invariants + assert((Hi != Memory || Lo == Memory) && "Invalid memory classification."); + assert((Hi != SSEUp || Lo == SSE) && "Invalid SSEUp classification."); + + NeededInt = 0; + NeededSSE = 0; + const Type *ResType = nullptr; + + switch (Lo) { + case NoClass: + if (Hi == NoClass) + return ABIArgInfo::getIgnore(); + // If the low part is just padding, it takes no register, leave ResType + // null. + assert((Hi == SSE || Hi == Integer || Hi == X87UP) && + "Unknown missing lo part"); + break; + + // AMD64-ABI 3.2.3p3: Rule 1. If the class is MEMORY, pass the argument + // on the stack. + case Memory: + // AMD64-ABI 3.2.3p3: Rule 5. If the class is X87, X87UP or + // COMPLEX_X87, it is passed in memory. + case X87: + case Complex_X87: + if (getRecordArgABI(dyn_cast<RecordType>(Ty)) == RAA_Indirect) + ++NeededInt; + return getIndirectResult(Ty, FreeIntRegs); + + case SSEUp: + case X87UP: + llvm_unreachable("Invalid classification for lo word."); + + // AMD64-ABI 3.2.3p3: Rule 2. If the class is INTEGER, the next + // available register of the sequence %rdi, %rsi, %rdx, %rcx, %r8 + // and %r9 is used. + case Integer: + ++NeededInt; + + // Pick an 8-byte type based on the preferred type. + ResType = getIntegerTypeAtOffset(Ty, 0, Ty, 0); + + // If we have a sign or zero extended integer, make sure to return Extend + // so that the parameter gets the right LLVM IR attributes. + if (Hi == NoClass && ResType->isInteger()) { + if (Ty->isInteger() && isPromotableInteger(cast<IntegerType>(Ty))) + return ABIArgInfo::getExtend(Ty); + } + + if (ResType->isInteger() && ResType->getSizeInBits() == 128) { + assert(Hi == Integer); + ++NeededInt; + return ABIArgInfo::getDirect(ResType); + } + break; + + // AMD64-ABI 3.2.3p3: Rule 3. If the class is SSE, the next + // available SSE register is used, the registers are taken in the + // order from %xmm0 to %xmm7. + case SSE: + ResType = getSSETypeAtOffset(Ty, 0, Ty, 0); + ++NeededSSE; + break; + } + + const Type *HighPart = nullptr; + switch (Hi) { + // Memory was handled previously, Complex_X87 and X87 should + // never occur as hi classes, and X87UP must be preceded by X87, + // which is passed in memory. + case Memory: + case X87: + case Complex_X87: + llvm_unreachable("Invalid classification for hi word."); + + case NoClass: + break; + + case Integer: + ++NeededInt; + // Pick an 8-byte type based on the preferred type. + HighPart = getIntegerTypeAtOffset(Ty, 8, Ty, 8); + + if (Lo == NoClass) // Pass HighPart at offset 8 in memory. + return ABIArgInfo::getDirect(HighPart, 8); + break; + + // X87UP generally doesn't occur here (long double is passed in + // memory), except in situations involving unions. + case X87UP: + case SSE: + ++NeededSSE; + HighPart = getSSETypeAtOffset(Ty, 8, Ty, 8); + + if (Lo == NoClass) // Pass HighPart at offset 8 in memory. + return ABIArgInfo::getDirect(HighPart, 8); + break; + + // AMD64-ABI 3.2.3p3: Rule 4. If the class is SSEUP, the + // eightbyte is passed in the upper half of the last used SSE + // register. This only happens when 128-bit vectors are passed. + case SSEUp: + assert(Lo == SSE && "Unexpected SSEUp classification"); + ResType = getByteVectorType(Ty); + break; + } + + // If a high part was specified, merge it together with the low part. It is + // known to pass in the high eightbyte of the result. We do this by forming a + // first class struct aggregate with the high and low part: {low, high} + if (HighPart) + ResType = createPairType(ResType, HighPart); + + return ABIArgInfo::getDirect(ResType); +} + +ABIArgInfo X86_64ABIInfo::classifyReturnType(const Type *RetTy) const { + // AMD64-ABI 3.2.3p4: Rule 1. Classify the return type with the + // classification algorithm. + + X86_64ABIInfo::Class Lo, Hi; + classify(RetTy, 0, Lo, Hi, /*isNamedArg*/ true); + + // Check some invariants + assert((Hi != Memory || Lo == Memory) && "Invalid memory classification."); + assert((Hi != SSEUp || Lo == SSE) && "Invalid SSEUp classification."); + + const Type *ResType = nullptr; + switch (Lo) { + case NoClass: + if (Hi == NoClass) + return ABIArgInfo::getIgnore(); + // If the low part is just padding, it takes no register, leave ResType + // null. + assert((Hi == SSE || Hi == Integer || Hi == X87UP) && + "Unknown missing lo part"); + break; + case SSEUp: + case X87UP: + llvm_unreachable("Invalid classification for lo word."); + + // AMD64-ABI 3.2.3p4: Rule 2. Types of class memory are returned via + // hidden argument. + case Memory: + return getIndirectReturnResult(RetTy); + + // AMD64-ABI 3.2.3p4: Rule 3. If the class is INTEGER, the next + // available register of the sequence %rax, %rdx is used. + case Integer: + ResType = getIntegerTypeAtOffset(RetTy, 0, RetTy, 0); + // If we have a sign or zero extended integer, make sure to return Extend + // so that the parameter gets the right LLVM IR attributes. + if (Hi == NoClass && ResType->isInteger()) { + if (const IntegerType *IntTy = dyn_cast<IntegerType>(RetTy)) { + if (isPromotableInteger(IntTy)) { + ABIArgInfo Info = ABIArgInfo::getExtend(RetTy); + return Info; + } + } + } + if (ResType->isInteger() && ResType->getSizeInBits() == 128) { + assert(Hi == Integer); + return ABIArgInfo::getDirect(ResType); + } + break; + + // AMD64-ABI 3.2.3p4: Rule 4. If the class is SSE, the next + // available SSE register of the sequence %xmm0, %xmm1 is used. + case SSE: + ResType = getSSETypeAtOffset(RetTy, 0, RetTy, 0); + break; + + // AMD64-ABI 3.2.3p4: Rule 6. If the class is X87, the value is + // returned on the X87 stack in %st0 as 80-bit x87 number. + case X87: + ResType = TB.getFloatType(APFloat::x87DoubleExtended(), Align(16)); + break; + + // AMD64-ABI 3.2.3p4: Rule 8. If the class is COMPLEX_X87, the real + // part of the value is returned in %st0 and the imaginary part in + // %st1. + case Complex_X87: + assert(Hi == Complex_X87 && "Unexpected ComplexX87 classification."); + { + const Type *X87Type = + TB.getFloatType(APFloat::x87DoubleExtended(), Align(16)); + FieldInfo Fields[] = {FieldInfo(X87Type, 0), FieldInfo(X87Type, 128)}; + ResType = + TB.getCoercedRecordType(Fields, TypeSize::getFixed(256), Align(16)); + } + break; + } + + const Type *HighPart = nullptr; + switch (Hi) { + // Memory was handled previously and X87 should + // never occur as a hi class. + case Memory: + case X87: + llvm_unreachable("Invalid classification for hi word."); + + case Complex_X87: + case NoClass: + break; + + case Integer: + HighPart = getIntegerTypeAtOffset(RetTy, 8, RetTy, 8); + if (Lo == NoClass) + return ABIArgInfo::getDirect(HighPart, 8); + break; + + case SSE: + HighPart = getSSETypeAtOffset(RetTy, 8, RetTy, 8); + if (Lo == NoClass) + return ABIArgInfo::getDirect(HighPart, 8); + break; + + // AMD64-ABI 3.2.3p4: Rule 5. If the class is SSEUP, the eightbyte + // is passed in the next available eightbyte chunk if the last used + // vector register. + // + // SSEUP should always be preceded by SSE, just widen. + case SSEUp: + assert(Lo == SSE && "Unexpected SSEUp classification."); + ResType = getByteVectorType(RetTy); + break; + + // AMD64-ABI 3.2.3p4: Rule 7. If the class is X87UP, the value is + // returned together with the previous X87 value in %st0. + case X87UP: + // If X87Up is preceded by X87, we don't need to do + // anything. However, in some cases with unions it may not be + // preceded by X87. In such situations we follow gcc and pass the + // extra bits in an SSE reg. + if (Lo != X87) { + HighPart = getSSETypeAtOffset(RetTy, 8, RetTy, 8); + if (Lo == NoClass) // Return HighPart at offset 8 in memory. + return ABIArgInfo::getDirect(HighPart, 8); + } + break; + } + + // If a high part was specified, merge it together with the low part. It is + // known to pass in the high eightbyte of the result. We do this by forming a + // first class struct aggregate with the high and low part: {low, high} + if (HighPart) + ResType = createPairType(ResType, HighPart); + + return ABIArgInfo::getDirect(ResType); +} + +/// Given a high and low type that can ideally +/// be used as elements of a two register pair to pass or return, return a +/// first class aggregate to represent them. For example, if the low part of +/// a by-value argument should be passed as i32* and the high part as float, +/// return {i32*, float}. +const Type *X86_64ABIInfo::createPairType(const Type *Lo, + const Type *Hi) const { + // In order to correctly satisfy the ABI, we need to the high part to start + // at offset 8. If the high and low parts we inferred are both 4-byte types + // (e.g. i32 and i32) then the resultant struct type ({i32,i32}) won't have + // the second element at offset 8. Check for this: + unsigned LoSize = (unsigned)Lo->getTypeAllocSize(); + Align HiAlign = Hi->getAlignment(); + unsigned HiStart = alignTo(LoSize, HiAlign); + + assert(HiStart != 0 && HiStart <= 8 && "Invalid x86-64 argument pair!"); + + // To handle this, we have to increase the size of the low part so that the + // second element will start at an 8 byte offset. We can't increase the size + // of the second element because it might make us access off the end of the + // struct. + const Type *AdjustedLo = Lo; + if (HiStart != 8) { + // There are usually two sorts of types the ABI generation code can produce + // for the low part of a pair that aren't 8 bytes in size: half, float or + // i8/i16/i32. This can also include pointers when they are 32-bit (X32 and + // NaCl). + // Promote these to a larger type. + if (Lo->isFloat()) { + const FloatType *FT = cast<FloatType>(Lo); + if (FT->getSemantics() == &APFloat::IEEEhalf() || + FT->getSemantics() == &APFloat::IEEEsingle() || + FT->getSemantics() == &APFloat::BFloat()) + AdjustedLo = TB.getFloatType(APFloat::IEEEdouble(), Align(8)); + } + // Promote integers and pointers to i64 + else if (Lo->isInteger() || Lo->isPointer()) + AdjustedLo = TB.getIntegerType(64, Align(8), /*Signed=*/false); + else + assert((Lo->isInteger() || Lo->isPointer()) && + "Invalid/unknown low type in pair"); + unsigned AdjustedLoSize = AdjustedLo->getSizeInBits().getFixedValue() / 8; + HiStart = alignTo(AdjustedLoSize, HiAlign); + } + + // Create the pair struct + FieldInfo Fields[] = {FieldInfo(AdjustedLo, 0), FieldInfo(Hi, HiStart * 8)}; + + // Verify the high part is at offset 8 + assert((8 * 8) == Fields[1].OffsetInBits && + "High part must be at offset 8 bytes"); + + return TB.getCoercedRecordType(Fields, TypeSize::getFixed(128), Align(8), + StructPacking::Default); +} + +static bool bitsContainNoUserData(const Type *Ty, unsigned StartBit, + unsigned EndBit) { + // If range is completely beyond type size, it's definitely padding + unsigned TySize = Ty->getSizeInBits().getFixedValue(); + if (TySize <= StartBit) + return true; + + // Handle arrays - check each element + if (const ArrayType *AT = dyn_cast<ArrayType>(Ty)) { + const Type *EltTy = AT->getElementType(); + unsigned EltSize = EltTy->getSizeInBits().getFixedValue(); + + for (unsigned I = 0; I < AT->getNumElements(); ++I) { + unsigned EltOffset = I * EltSize; + if (EltOffset >= EndBit) + break; + + unsigned EltStart = (EltOffset < StartBit) ? StartBit - EltOffset : 0; + if (!bitsContainNoUserData(EltTy, EltStart, EndBit - EltOffset)) + return false; + } + return true; + } + + // Handle structs - check all fields and base classes + if (const RecordType *RT = dyn_cast<RecordType>(Ty)) { + if (RT->isUnion()) { + for (const auto &Field : RT->getFields()) { + if (Field.IsUnnamedBitfield) + continue; + + unsigned FieldStart = + (Field.OffsetInBits < StartBit) ? StartBit - Field.OffsetInBits : 0; + unsigned FieldEnd = + FieldStart + Field.FieldType->getSizeInBits().getFixedValue(); + + // Check if field overlaps with the queried range + if (FieldStart < EndBit && FieldEnd > StartBit) { + // There's an overlap, so there is user data + unsigned RelativeStart = + (StartBit > FieldStart) ? StartBit - FieldStart : 0; + unsigned RelativeEnd = + (EndBit < FieldEnd) + ? EndBit - FieldStart + : Field.FieldType->getSizeInBits().getFixedValue(); + + if (!bitsContainNoUserData(Field.FieldType, RelativeStart, + RelativeEnd)) { + return false; + } + } + } + return true; + } + // Check base classes first (for C++ records) + if (RT->isCXXRecord()) { + for (unsigned I = 0; I < RT->getNumBaseClasses(); ++I) { + const FieldInfo &Base = RT->getBaseClasses()[I]; + if (Base.OffsetInBits >= EndBit) + continue; + + unsigned BaseStart = + (Base.OffsetInBits < StartBit) ? StartBit - Base.OffsetInBits : 0; + if (!bitsContainNoUserData(Base.FieldType, BaseStart, + EndBit - Base.OffsetInBits)) + return false; + } + } + + for (unsigned I = 0; I < RT->getNumFields(); ++I) { + const FieldInfo &Field = RT->getFields()[I]; + if (Field.OffsetInBits >= EndBit) + break; + + unsigned FieldStart = + (Field.OffsetInBits < StartBit) ? StartBit - Field.OffsetInBits : 0; + if (!bitsContainNoUserData(Field.FieldType, FieldStart, + EndBit - Field.OffsetInBits)) + return false; + } + return true; + } + + // For unions, vectors, and primitives - assume all bits are user data + return false; +} + +const Type *X86_64ABIInfo::getIntegerTypeAtOffset(const Type *ABIType, + unsigned ABIOffset, + const Type *SourceTy, + unsigned SourceOffset, + bool InMemory) const { + + const Type *WorkingType = ABIType; + if (InMemory && ABIType->isInteger()) { + const auto *IT = cast<IntegerType>(ABIType); + unsigned OriginalBitWidth = IT->getSizeInBits().getFixedValue(); + + unsigned WidenedBitWidth = OriginalBitWidth; + if (OriginalBitWidth <= 8) { + WidenedBitWidth = 8; + } else { + WidenedBitWidth = llvm::bit_ceil(OriginalBitWidth); + } + + if (WidenedBitWidth != OriginalBitWidth) { + WorkingType = TB.getIntegerType(WidenedBitWidth, ABIType->getAlignment(), + IT->isSigned()); + } + } + // If we're dealing with an un-offset ABI type, then it means that we're + // returning an 8-byte unit starting with it. See if we can safely use it. + if (ABIOffset == 0) { + // Pointers and int64's always fill the 8-byte unit. + if ((WorkingType->isPointer() && Has64BitPointers) || + (WorkingType->isInteger() && + cast<IntegerType>(WorkingType)->getSizeInBits() == 64)) + return ABIType; + + // If we have a 1/2/4-byte integer, we can use it only if the rest of the + // goodness in the source type is just tail padding. This is allowed to + // kick in for struct {double,int} on the int, but not on + // struct{double,int,int} because we wouldn't return the second int. We + // have to do this analysis on the source type because we can't depend on + // unions being lowered a specific way etc. + if ((WorkingType->isInteger() && + (cast<IntegerType>(WorkingType)->getSizeInBits() == 1 || + cast<IntegerType>(WorkingType)->getSizeInBits() == 8 || + cast<IntegerType>(WorkingType)->getSizeInBits() == 16 || + cast<IntegerType>(WorkingType)->getSizeInBits() == 32)) || + (WorkingType->isPointer() && !Has64BitPointers)) { + + unsigned BitWidth = WorkingType->isPointer() + ? 32 + : cast<IntegerType>(WorkingType)->getSizeInBits(); + + if (bitsContainNoUserData(SourceTy, SourceOffset * 8 + BitWidth, + SourceOffset * 8 + 64)) + return WorkingType; + } + } + + if (const auto *RTy = dyn_cast<RecordType>(ABIType)) { + if (RTy->isUnion()) { + const Type *ReducedType = reduceUnionForX8664(RTy, TB); + if (ReducedType) + return getIntegerTypeAtOffset(ReducedType, ABIOffset, SourceTy, + SourceOffset, true); + } + if (const FieldInfo *Element = + RTy->getElementContainingOffset(ABIOffset * 8)) { + + unsigned ElementOffsetBytes = Element->OffsetInBits / 8; + return getIntegerTypeAtOffset(Element->FieldType, + ABIOffset - ElementOffsetBytes, SourceTy, + SourceOffset, true); + } + } + + if (const auto *ATy = dyn_cast<ArrayType>(ABIType)) { + const Type *EltTy = ATy->getElementType(); + unsigned EltSize = EltTy->getSizeInBits() / 8; + if (EltSize > 0) { + unsigned EltOffset = (ABIOffset / EltSize) * EltSize; + return getIntegerTypeAtOffset(EltTy, ABIOffset - EltOffset, SourceTy, + SourceOffset, true); + } + } + + // If we have a 128-bit integer, we can pass it safely using an i128 + // so we return that + if (ABIType->isInteger() && ABIType->getSizeInBits() == 128) { + assert(ABIOffset == 0); + return ABIType; + } + + unsigned TySizeInBytes = + llvm::divideCeil(SourceTy->getSizeInBits().getFixedValue(), 8); + if (auto *IT = dyn_cast<IntegerType>(SourceTy)) { + if (IT->isBitInt()) + TySizeInBytes = + alignTo(SourceTy->getSizeInBits().getFixedValue(), 64) / 8; + } + assert(TySizeInBytes != SourceOffset && "Empty field?"); + unsigned AvailableSize = TySizeInBytes - SourceOffset; + return TB.getIntegerType(std::min(AvailableSize, 8U) * 8, Align(1), false); +} +/// Returns the floating point type at the specified offset within a type, or +/// nullptr if no floating point type is found at that offset. +const Type *X86_64ABIInfo::getFPTypeAtOffset(const Type *Ty, + unsigned Offset) const { + // Check for direct match at offset 0 + if (Offset == 0 && Ty->isFloat()) + return Ty; + + if (const ComplexType *CT = dyn_cast<ComplexType>(Ty)) { + const Type *ElementType = CT->getElementType(); + unsigned ElementSize = ElementType->getSizeInBits().getFixedValue() / 8; + + if (Offset == 0 || Offset == ElementSize) + return ElementType; + return nullptr; + } + + // Handle struct types by checking each field + if (const RecordType *RT = dyn_cast<RecordType>(Ty)) { + if (const FieldInfo *Element = RT->getElementContainingOffset(Offset * 8)) { + unsigned ElementOffsetBytes = Element->OffsetInBits / 8; + return getFPTypeAtOffset(Element->FieldType, Offset - ElementOffsetBytes); + } + } + + // Handle array types + if (const ArrayType *AT = dyn_cast<ArrayType>(Ty)) { + const Type *EltTy = AT->getElementType(); + unsigned EltSize = EltTy->getSizeInBits() / 8; + unsigned EltIndex = Offset / EltSize; + + return getFPTypeAtOffset(EltTy, Offset - (EltIndex * EltSize)); + } + + // No floating point type found at this offset + return nullptr; +} + +/// Helper to check if a floating point type matches specific semantics +static bool isFloatTypeWithSemantics(const Type *Ty, + const fltSemantics &Semantics) { + if (!Ty->isFloat()) + return false; + const FloatType *FT = cast<FloatType>(Ty); + return FT->getSemantics() == &Semantics; +} + +/// GetSSETypeAtOffset - Return a type that will be passed by the backend in the +/// low 8 bytes of an XMM register, corresponding to the SSE class. +const Type *X86_64ABIInfo::getSSETypeAtOffset(const Type *ABIType, + unsigned ABIOffset, + const Type *SourceTy, + unsigned SourceOffset) const { + + if (const auto *RTy = dyn_cast<RecordType>(ABIType)) { + if (RTy->isUnion()) { + const Type *ReducedType = reduceUnionForX8664(RTy, TB); + if (ReducedType) { + return getSSETypeAtOffset(ReducedType, ABIOffset, SourceTy, + SourceOffset); + } + } + } + + auto Is16bitFpTy = [](const Type *T) { + return isFloatTypeWithSemantics(T, APFloat::IEEEhalf()) || + isFloatTypeWithSemantics(T, APFloat::BFloat()); + }; + + // Get the floating point type at the requested offset + const Type *T0 = getFPTypeAtOffset(ABIType, ABIOffset); + if (!T0 || isFloatTypeWithSemantics(T0, APFloat::IEEEdouble())) + return TB.getFloatType(APFloat::IEEEdouble(), Align(8)); + + // Calculate remaining source size in bytes + unsigned SourceSize = + (SourceTy->getSizeInBits().getFixedValue() / 8) - SourceOffset; + + // Try to get adjacent FP type + const Type *T1 = nullptr; + unsigned T0Size = + alignTo(T0->getSizeInBits().getFixedValue(), T0->getAlignment().value()) / + 8; + if (SourceSize > T0Size) + T1 = getFPTypeAtOffset(ABIType, ABIOffset + T0Size); + + if (T1 == nullptr) { + if (Is16bitFpTy(T0) && SourceSize > 4) + T1 = getFPTypeAtOffset(ABIType, ABIOffset + 4); + + if (T1 == nullptr) + return T0; + } + // Handle vector cases + if (isFloatTypeWithSemantics(T0, APFloat::IEEEsingle()) && + isFloatTypeWithSemantics(T1, APFloat::IEEEsingle())) + return TB.getVectorType(T0, ElementCount::getFixed(2), Align(8)); + + if (Is16bitFpTy(T0) && Is16bitFpTy(T1)) { + const Type *T2 = nullptr; + if (SourceSize > 4) + T2 = getFPTypeAtOffset(ABIType, ABIOffset + 4); + if (!T2) + return TB.getVectorType(T0, ElementCount::getFixed(2), Align(8)); + return TB.getVectorType(T0, ElementCount::getFixed(4), Align(8)); + } + + // Mixed half-float cases + if (Is16bitFpTy(T0) || Is16bitFpTy(T1)) + return TB.getVectorType(TB.getFloatType(APFloat::IEEEhalf(), Align(2)), + ElementCount::getFixed(4), Align(8)); + + // Default to double + return TB.getFloatType(APFloat::IEEEdouble(), Align(8)); +} + +/// The ABI specifies that a value should be passed in a full vector XMM/YMM +/// register. Pick an LLVM IR type that will be passed as a vector register. +const Type *X86_64ABIInfo::getByteVectorType(const Type *Ty) const { + // Wrapper structs/arrays that only contain vectors are passed just like + // vectors; strip them off if present. + if (const Type *InnerTy = isSingleElementStruct(Ty)) + Ty = InnerTy; + + // Handle vector types + if (const VectorType *VT = dyn_cast<VectorType>(Ty)) { + // Don't pass vXi128 vectors in their native type, the backend can't + // legalize them. + if (getABICompatInfo().Flags.PassInt128VectorsInMem && + VT->getElementType()->isInteger() && + cast<IntegerType>(VT->getElementType())->getSizeInBits() == 128) { + unsigned Size = VT->getSizeInBits().getFixedValue(); + return TB.getVectorType(TB.getIntegerType(64, Align(8), /*Signed=*/false), + ElementCount::getFixed(Size / 64), + Align(Size / 8)); + } + return VT; + } + + // Handle fp128 + if (isFloatTypeWithSemantics(Ty, APFloat::IEEEquad())) + return Ty; + + // We couldn't find the preferred IR vector type for 'Ty'. + unsigned Size = Ty->getSizeInBits().getFixedValue(); + assert((Size == 128 || Size == 256 || Size == 512) && "Invalid vector size"); + + return TB.getVectorType(TB.getFloatType(APFloat::IEEEdouble(), Align(8)), + ElementCount::getFixed(Size / 64), Align(Size / 8)); +} + +// Returns the single element if this is a single-element struct wrapper +const Type *X86_64ABIInfo::isSingleElementStruct(const Type *Ty) const { + const auto *RT = dyn_cast<RecordType>(Ty); + if (!RT) + return nullptr; + + if (RT->isPolymorphic() || RT->hasNonTrivialCopyConstructor() || + RT->hasNonTrivialDestructor() || RT->hasFlexibleArrayMember() || + RT->getNumVirtualBaseClasses() != 0) + return nullptr; ---------------- vortex73 wrote:
Hmm maybe... I'll give it a try :) https://github.com/llvm/llvm-project/pull/140112 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
