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Diffstat (limited to 'lib/CodeGen/TargetInfo.cpp')
| -rw-r--r-- | lib/CodeGen/TargetInfo.cpp | 1904 |
1 files changed, 1904 insertions, 0 deletions
diff --git a/lib/CodeGen/TargetInfo.cpp b/lib/CodeGen/TargetInfo.cpp new file mode 100644 index 000000000000..e5fd47ec2d16 --- /dev/null +++ b/lib/CodeGen/TargetInfo.cpp @@ -0,0 +1,1904 @@ +//===---- TargetInfo.cpp - Encapsulate target details -----------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// These classes wrap the information about a call or function +// definition used to handle ABI compliancy. +// +//===----------------------------------------------------------------------===// + +#include "TargetInfo.h" +#include "ABIInfo.h" +#include "CodeGenFunction.h" +#include "clang/AST/RecordLayout.h" +#include "llvm/Type.h" +#include "llvm/ADT/StringExtras.h" +#include "llvm/ADT/Triple.h" +#include "llvm/Support/raw_ostream.h" +using namespace clang; +using namespace CodeGen; + +ABIInfo::~ABIInfo() {} + +void ABIArgInfo::dump() const { + llvm::raw_ostream &OS = llvm::errs(); + OS << "(ABIArgInfo Kind="; + switch (TheKind) { + case Direct: + OS << "Direct"; + break; + case Extend: + OS << "Extend"; + break; + case Ignore: + OS << "Ignore"; + break; + case Coerce: + OS << "Coerce Type="; + getCoerceToType()->print(OS); + break; + case Indirect: + OS << "Indirect Align=" << getIndirectAlign(); + break; + case Expand: + OS << "Expand"; + break; + } + OS << ")\n"; +} + +TargetCodeGenInfo::~TargetCodeGenInfo() { delete Info; } + +static bool isEmptyRecord(ASTContext &Context, QualType T, bool AllowArrays); + +/// isEmptyField - Return true iff a the field is "empty", that is it +/// is an unnamed bit-field or an (array of) empty record(s). +static bool isEmptyField(ASTContext &Context, const FieldDecl *FD, + bool AllowArrays) { + if (FD->isUnnamedBitfield()) + return true; + + QualType FT = FD->getType(); + + // Constant arrays of empty records count as empty, strip them off. + if (AllowArrays) + while (const ConstantArrayType *AT = Context.getAsConstantArrayType(FT)) + FT = AT->getElementType(); + + return isEmptyRecord(Context, FT, AllowArrays); +} + +/// isEmptyRecord - Return true iff a structure contains only empty +/// fields. Note that a structure with a flexible array member is not +/// considered empty. +static bool isEmptyRecord(ASTContext &Context, QualType T, bool AllowArrays) { + const RecordType *RT = T->getAs<RecordType>(); + if (!RT) + return 0; + const RecordDecl *RD = RT->getDecl(); + if (RD->hasFlexibleArrayMember()) + return false; + for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end(); + i != e; ++i) + if (!isEmptyField(Context, *i, AllowArrays)) + return false; + return true; +} + +/// hasNonTrivialDestructorOrCopyConstructor - Determine if a type has either +/// a non-trivial destructor or a non-trivial copy constructor. +static bool hasNonTrivialDestructorOrCopyConstructor(const RecordType *RT) { + const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()); + if (!RD) + return false; + + return !RD->hasTrivialDestructor() || !RD->hasTrivialCopyConstructor(); +} + +/// isRecordWithNonTrivialDestructorOrCopyConstructor - Determine if a type is +/// a record type with either a non-trivial destructor or a non-trivial copy +/// constructor. +static bool isRecordWithNonTrivialDestructorOrCopyConstructor(QualType T) { + const RecordType *RT = T->getAs<RecordType>(); + if (!RT) + return false; + + return hasNonTrivialDestructorOrCopyConstructor(RT); +} + +/// isSingleElementStruct - Determine if a structure is a "single +/// element struct", i.e. it has exactly one non-empty field or +/// exactly one field which is itself a single element +/// struct. Structures with flexible array members are never +/// considered single element structs. +/// +/// \return The field declaration for the single non-empty field, if +/// it exists. +static const Type *isSingleElementStruct(QualType T, ASTContext &Context) { + const RecordType *RT = T->getAsStructureType(); + if (!RT) + return 0; + + const RecordDecl *RD = RT->getDecl(); + if (RD->hasFlexibleArrayMember()) + return 0; + + const Type *Found = 0; + for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end(); + i != e; ++i) { + const FieldDecl *FD = *i; + QualType FT = FD->getType(); + + // Ignore empty fields. + if (isEmptyField(Context, FD, true)) + continue; + + // If we already found an element then this isn't a single-element + // struct. + if (Found) + return 0; + + // Treat single element arrays as the element. + while (const ConstantArrayType *AT = Context.getAsConstantArrayType(FT)) { + if (AT->getSize().getZExtValue() != 1) + break; + FT = AT->getElementType(); + } + + if (!CodeGenFunction::hasAggregateLLVMType(FT)) { + Found = FT.getTypePtr(); + } else { + Found = isSingleElementStruct(FT, Context); + if (!Found) + return 0; + } + } + + return Found; +} + +static bool is32Or64BitBasicType(QualType Ty, ASTContext &Context) { + if (!Ty->getAs<BuiltinType>() && !Ty->isAnyPointerType() && + !Ty->isAnyComplexType() && !Ty->isEnumeralType() && + !Ty->isBlockPointerType()) + return false; + + uint64_t Size = Context.getTypeSize(Ty); + return Size == 32 || Size == 64; +} + +/// canExpandIndirectArgument - Test whether an argument type which is to be +/// passed indirectly (on the stack) would have the equivalent layout if it was +/// expanded into separate arguments. If so, we prefer to do the latter to avoid +/// inhibiting optimizations. +/// +// FIXME: This predicate is missing many cases, currently it just follows +// llvm-gcc (checks that all fields are 32-bit or 64-bit primitive types). We +// should probably make this smarter, or better yet make the LLVM backend +// capable of handling it. +static bool canExpandIndirectArgument(QualType Ty, ASTContext &Context) { + // We can only expand structure types. + const RecordType *RT = Ty->getAs<RecordType>(); + if (!RT) + return false; + + // We can only expand (C) structures. + // + // FIXME: This needs to be generalized to handle classes as well. + const RecordDecl *RD = RT->getDecl(); + if (!RD->isStruct() || isa<CXXRecordDecl>(RD)) + return false; + + for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end(); + i != e; ++i) { + const FieldDecl *FD = *i; + + if (!is32Or64BitBasicType(FD->getType(), Context)) + return false; + + // FIXME: Reject bit-fields wholesale; there are two problems, we don't know + // how to expand them yet, and the predicate for telling if a bitfield still + // counts as "basic" is more complicated than what we were doing previously. + if (FD->isBitField()) + return false; + } + + return true; +} + +static bool typeContainsSSEVector(const RecordDecl *RD, ASTContext &Context) { + for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end(); + i != e; ++i) { + const FieldDecl *FD = *i; + + if (FD->getType()->isVectorType() && + Context.getTypeSize(FD->getType()) >= 128) + return true; + + if (const RecordType* RT = FD->getType()->getAs<RecordType>()) + if (typeContainsSSEVector(RT->getDecl(), Context)) + return true; + } + + return false; +} + +namespace { +/// DefaultABIInfo - The default implementation for ABI specific +/// details. This implementation provides information which results in +/// self-consistent and sensible LLVM IR generation, but does not +/// conform to any particular ABI. +class DefaultABIInfo : public ABIInfo { + ABIArgInfo classifyReturnType(QualType RetTy, + ASTContext &Context, + llvm::LLVMContext &VMContext) const; + + ABIArgInfo classifyArgumentType(QualType RetTy, + ASTContext &Context, + llvm::LLVMContext &VMContext) const; + + virtual void computeInfo(CGFunctionInfo &FI, ASTContext &Context, + llvm::LLVMContext &VMContext) const { + FI.getReturnInfo() = classifyReturnType(FI.getReturnType(), Context, + VMContext); + for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end(); + it != ie; ++it) + it->info = classifyArgumentType(it->type, Context, VMContext); + } + + virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty, + CodeGenFunction &CGF) const; +}; + +class DefaultTargetCodeGenInfo : public TargetCodeGenInfo { +public: + DefaultTargetCodeGenInfo():TargetCodeGenInfo(new DefaultABIInfo()) {}; +}; + +llvm::Value *DefaultABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty, + CodeGenFunction &CGF) const { + return 0; +} + +ABIArgInfo DefaultABIInfo::classifyArgumentType(QualType Ty, + ASTContext &Context, + llvm::LLVMContext &VMContext) const { + if (CodeGenFunction::hasAggregateLLVMType(Ty)) { + return ABIArgInfo::getIndirect(0); + } else { + return (Ty->isPromotableIntegerType() ? + ABIArgInfo::getExtend() : ABIArgInfo::getDirect()); + } +} + +/// X86_32ABIInfo - The X86-32 ABI information. +class X86_32ABIInfo : public ABIInfo { + ASTContext &Context; + bool IsDarwinVectorABI; + bool IsSmallStructInRegABI; + + static bool isRegisterSize(unsigned Size) { + return (Size == 8 || Size == 16 || Size == 32 || Size == 64); + } + + static bool shouldReturnTypeInRegister(QualType Ty, ASTContext &Context); + + static unsigned getIndirectArgumentAlignment(QualType Ty, + ASTContext &Context); + +public: + ABIArgInfo classifyReturnType(QualType RetTy, + ASTContext &Context, + llvm::LLVMContext &VMContext) const; + + ABIArgInfo classifyArgumentType(QualType RetTy, + ASTContext &Context, + llvm::LLVMContext &VMContext) const; + + virtual void computeInfo(CGFunctionInfo &FI, ASTContext &Context, + llvm::LLVMContext &VMContext) const { + FI.getReturnInfo() = classifyReturnType(FI.getReturnType(), Context, + VMContext); + for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end(); + it != ie; ++it) + it->info = classifyArgumentType(it->type, Context, VMContext); + } + + virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty, + CodeGenFunction &CGF) const; + + X86_32ABIInfo(ASTContext &Context, bool d, bool p) + : ABIInfo(), Context(Context), IsDarwinVectorABI(d), + IsSmallStructInRegABI(p) {} +}; + +class X86_32TargetCodeGenInfo : public TargetCodeGenInfo { +public: + X86_32TargetCodeGenInfo(ASTContext &Context, bool d, bool p) + :TargetCodeGenInfo(new X86_32ABIInfo(Context, d, p)) {}; +}; + +} + +/// shouldReturnTypeInRegister - Determine if the given type should be +/// passed in a register (for the Darwin ABI). +bool X86_32ABIInfo::shouldReturnTypeInRegister(QualType Ty, + ASTContext &Context) { + uint64_t Size = Context.getTypeSize(Ty); + + // Type must be register sized. + if (!isRegisterSize(Size)) + return false; + + if (Ty->isVectorType()) { + // 64- and 128- bit vectors inside structures are not returned in + // registers. + if (Size == 64 || Size == 128) + return false; + + return true; + } + + // If this is a builtin, pointer, enum, or complex type, it is ok. + if (Ty->getAs<BuiltinType>() || Ty->isAnyPointerType() || + Ty->isAnyComplexType() || Ty->isEnumeralType() || + Ty->isBlockPointerType()) + return true; + + // Arrays are treated like records. + if (const ConstantArrayType *AT = Context.getAsConstantArrayType(Ty)) + return shouldReturnTypeInRegister(AT->getElementType(), Context); + + // Otherwise, it must be a record type. + const RecordType *RT = Ty->getAs<RecordType>(); + if (!RT) return false; + + // Structure types are passed in register if all fields would be + // passed in a register. + for (RecordDecl::field_iterator i = RT->getDecl()->field_begin(), + e = RT->getDecl()->field_end(); i != e; ++i) { + const FieldDecl *FD = *i; + + // Empty fields are ignored. + if (isEmptyField(Context, FD, true)) + continue; + + // Check fields recursively. + if (!shouldReturnTypeInRegister(FD->getType(), Context)) + return false; + } + + return true; +} + +ABIArgInfo X86_32ABIInfo::classifyReturnType(QualType RetTy, + ASTContext &Context, + llvm::LLVMContext &VMContext) const { + if (RetTy->isVoidType()) { + return ABIArgInfo::getIgnore(); + } else if (const VectorType *VT = RetTy->getAs<VectorType>()) { + // On Darwin, some vectors are returned in registers. + if (IsDarwinVectorABI) { + uint64_t Size = Context.getTypeSize(RetTy); + + // 128-bit vectors are a special case; they are returned in + // registers and we need to make sure to pick a type the LLVM + // backend will like. + if (Size == 128) + return ABIArgInfo::getCoerce(llvm::VectorType::get( + llvm::Type::getInt64Ty(VMContext), 2)); + + // Always return in register if it fits in a general purpose + // register, or if it is 64 bits and has a single element. + if ((Size == 8 || Size == 16 || Size == 32) || + (Size == 64 && VT->getNumElements() == 1)) + return ABIArgInfo::getCoerce(llvm::IntegerType::get(VMContext, Size)); + + return ABIArgInfo::getIndirect(0); + } + + return ABIArgInfo::getDirect(); + } else if (CodeGenFunction::hasAggregateLLVMType(RetTy)) { + if (const RecordType *RT = RetTy->getAsStructureType()) { + // Structures with either a non-trivial destructor or a non-trivial + // copy constructor are always indirect. + if (hasNonTrivialDestructorOrCopyConstructor(RT)) + return ABIArgInfo::getIndirect(0, /*ByVal=*/false); + + // Structures with flexible arrays are always indirect. + if (RT->getDecl()->hasFlexibleArrayMember()) + return ABIArgInfo::getIndirect(0); + } + + // If specified, structs and unions are always indirect. + if (!IsSmallStructInRegABI && !RetTy->isAnyComplexType()) + return ABIArgInfo::getIndirect(0); + + // Classify "single element" structs as their element type. + if (const Type *SeltTy = isSingleElementStruct(RetTy, Context)) { + if (const BuiltinType *BT = SeltTy->getAs<BuiltinType>()) { + if (BT->isIntegerType()) { + // We need to use the size of the structure, padding + // bit-fields can adjust that to be larger than the single + // element type. + uint64_t Size = Context.getTypeSize(RetTy); + return ABIArgInfo::getCoerce( + llvm::IntegerType::get(VMContext, (unsigned) Size)); + } else if (BT->getKind() == BuiltinType::Float) { + assert(Context.getTypeSize(RetTy) == Context.getTypeSize(SeltTy) && + "Unexpect single element structure size!"); + return ABIArgInfo::getCoerce(llvm::Type::getFloatTy(VMContext)); + } else if (BT->getKind() == BuiltinType::Double) { + assert(Context.getTypeSize(RetTy) == Context.getTypeSize(SeltTy) && + "Unexpect single element structure size!"); + return ABIArgInfo::getCoerce(llvm::Type::getDoubleTy(VMContext)); + } + } else if (SeltTy->isPointerType()) { + // FIXME: It would be really nice if this could come out as the proper + // pointer type. + const llvm::Type *PtrTy = llvm::Type::getInt8PtrTy(VMContext); + return ABIArgInfo::getCoerce(PtrTy); + } else if (SeltTy->isVectorType()) { + // 64- and 128-bit vectors are never returned in a + // register when inside a structure. + uint64_t Size = Context.getTypeSize(RetTy); + if (Size == 64 || Size == 128) + return ABIArgInfo::getIndirect(0); + + return classifyReturnType(QualType(SeltTy, 0), Context, VMContext); + } + } + + // Small structures which are register sized are generally returned + // in a register. + if (X86_32ABIInfo::shouldReturnTypeInRegister(RetTy, Context)) { + uint64_t Size = Context.getTypeSize(RetTy); + return ABIArgInfo::getCoerce(llvm::IntegerType::get(VMContext, Size)); + } + + return ABIArgInfo::getIndirect(0); + } else { + return (RetTy->isPromotableIntegerType() ? + ABIArgInfo::getExtend() : ABIArgInfo::getDirect()); + } +} + +unsigned X86_32ABIInfo::getIndirectArgumentAlignment(QualType Ty, + ASTContext &Context) { + unsigned Align = Context.getTypeAlign(Ty); + if (Align < 128) return 0; + if (const RecordType* RT = Ty->getAs<RecordType>()) + if (typeContainsSSEVector(RT->getDecl(), Context)) + return 16; + return 0; +} + +ABIArgInfo X86_32ABIInfo::classifyArgumentType(QualType Ty, + ASTContext &Context, + llvm::LLVMContext &VMContext) const { + // FIXME: Set alignment on indirect arguments. + if (CodeGenFunction::hasAggregateLLVMType(Ty)) { + // Structures with flexible arrays are always indirect. + if (const RecordType *RT = Ty->getAsStructureType()) + if (RT->getDecl()->hasFlexibleArrayMember()) + return ABIArgInfo::getIndirect(getIndirectArgumentAlignment(Ty, + Context)); + + // Ignore empty structs. + if (Ty->isStructureType() && Context.getTypeSize(Ty) == 0) + return ABIArgInfo::getIgnore(); + + // Expand small (<= 128-bit) record types when we know that the stack layout + // of those arguments will match the struct. This is important because the + // LLVM backend isn't smart enough to remove byval, which inhibits many + // optimizations. + if (Context.getTypeSize(Ty) <= 4*32 && + canExpandIndirectArgument(Ty, Context)) + return ABIArgInfo::getExpand(); + + return ABIArgInfo::getIndirect(getIndirectArgumentAlignment(Ty, Context)); + } else { + return (Ty->isPromotableIntegerType() ? + ABIArgInfo::getExtend() : ABIArgInfo::getDirect()); + } +} + +llvm::Value *X86_32ABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty, + CodeGenFunction &CGF) const { + const llvm::Type *BP = llvm::Type::getInt8PtrTy(CGF.getLLVMContext()); + const llvm::Type *BPP = llvm::PointerType::getUnqual(BP); + + CGBuilderTy &Builder = CGF.Builder; + llvm::Value *VAListAddrAsBPP = Builder.CreateBitCast(VAListAddr, BPP, + "ap"); + llvm::Value *Addr = Builder.CreateLoad(VAListAddrAsBPP, "ap.cur"); + llvm::Type *PTy = + llvm::PointerType::getUnqual(CGF.ConvertType(Ty)); + llvm::Value *AddrTyped = Builder.CreateBitCast(Addr, PTy); + + uint64_t Offset = + llvm::RoundUpToAlignment(CGF.getContext().getTypeSize(Ty) / 8, 4); + llvm::Value *NextAddr = + Builder.CreateGEP(Addr, llvm::ConstantInt::get( + llvm::Type::getInt32Ty(CGF.getLLVMContext()), Offset), + "ap.next"); + Builder.CreateStore(NextAddr, VAListAddrAsBPP); + + return AddrTyped; +} + +namespace { +/// X86_64ABIInfo - The X86_64 ABI information. +class X86_64ABIInfo : public ABIInfo { + enum Class { + Integer = 0, + SSE, + SSEUp, + X87, + X87Up, + ComplexX87, + NoClass, + Memory + }; + + /// merge - Implement the X86_64 ABI merging algorithm. + /// + /// Merge an accumulating classification \arg Accum with a field + /// classification \arg Field. + /// + /// \param Accum - The accumulating classification. This should + /// always be either NoClass or the result of a previous merge + /// call. In addition, this should never be Memory (the caller + /// should just return Memory for the aggregate). + Class merge(Class Accum, Class Field) const; + + /// classify - Determine the x86_64 register classes in which the + /// given type T should be passed. + /// + /// \param Lo - The classification for the parts of the type + /// residing in the low word of the containing object. + /// + /// \param Hi - The classification for the parts of the type + /// residing in the high word of the containing object. + /// + /// \param OffsetBase - The bit offset of this type in the + /// containing object. Some parameters are classified different + /// depending on whether they straddle an eightbyte boundary. + /// + /// If a word is unused its result will be NoClass; if a type should + /// be passed in Memory then at least the classification of \arg Lo + /// will be Memory. + /// + /// The \arg Lo class will be NoClass iff the argument is ignored. + /// + /// If the \arg Lo class is ComplexX87, then the \arg Hi class will + /// also be ComplexX87. + void classify(QualType T, ASTContext &Context, uint64_t OffsetBase, + Class &Lo, Class &Hi) const; + + /// getCoerceResult - Given a source type \arg Ty and an LLVM type + /// to coerce to, chose the best way to pass Ty in the same place + /// that \arg CoerceTo would be passed, but while keeping the + /// emitted code as simple as possible. + /// + /// FIXME: Note, this should be cleaned up to just take an enumeration of all + /// the ways we might want to pass things, instead of constructing an LLVM + /// type. This makes this code more explicit, and it makes it clearer that we + /// are also doing this for correctness in the case of passing scalar types. + ABIArgInfo getCoerceResult(QualType Ty, + const llvm::Type *CoerceTo, + ASTContext &Context) const; + + /// getIndirectResult - Give a source type \arg Ty, return a suitable result + /// such that the argument will be passed in memory. + ABIArgInfo getIndirectResult(QualType Ty, + ASTContext &Context) const; + + ABIArgInfo classifyReturnType(QualType RetTy, + ASTContext &Context, + llvm::LLVMContext &VMContext) const; + + ABIArgInfo classifyArgumentType(QualType Ty, + ASTContext &Context, + llvm::LLVMContext &VMContext, + unsigned &neededInt, + unsigned &neededSSE) const; + +public: + virtual void computeInfo(CGFunctionInfo &FI, ASTContext &Context, + llvm::LLVMContext &VMContext) const; + + virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty, + CodeGenFunction &CGF) const; +}; + +class X86_64TargetCodeGenInfo : public TargetCodeGenInfo { +public: + X86_64TargetCodeGenInfo():TargetCodeGenInfo(new X86_64ABIInfo()) {}; +}; + +} + +X86_64ABIInfo::Class X86_64ABIInfo::merge(Class Accum, + Class Field) const { + // 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 != ComplexX87) && + "Invalid accumulated classification during merge."); + if (Accum == Field || Field == NoClass) + return Accum; + else if (Field == Memory) + return Memory; + else if (Accum == NoClass) + return Field; + else if (Accum == Integer || Field == Integer) + return Integer; + else if (Field == X87 || Field == X87Up || Field == ComplexX87 || + Accum == X87 || Accum == X87Up) + return Memory; + else + return SSE; +} + +void X86_64ABIInfo::classify(QualType Ty, + ASTContext &Context, + uint64_t OffsetBase, + Class &Lo, Class &Hi) const { + // FIXME: This code can be simplified by introducing a simple value class for + // Class pairs with appropriate constructor methods for the various + // situations. + + // FIXME: Some of the split computations are wrong; unaligned vectors + // shouldn't be passed in registers for example, so there is no chance they + // can straddle an eightbyte. Verify & simplify. + + Lo = Hi = NoClass; + + Class &Current = OffsetBase < 64 ? Lo : Hi; + Current = Memory; + + if (const BuiltinType *BT = Ty->getAs<BuiltinType>()) { + BuiltinType::Kind k = BT->getKind(); + + if (k == BuiltinType::Void) { + Current = NoClass; + } else if (k == BuiltinType::Int128 || k == BuiltinType::UInt128) { + Lo = Integer; + Hi = Integer; + } else if (k >= BuiltinType::Bool && k <= BuiltinType::LongLong) { + Current = Integer; + } else if (k == BuiltinType::Float || k == BuiltinType::Double) { + Current = SSE; + } else if (k == BuiltinType::LongDouble) { + Lo = X87; + Hi = X87Up; + } + // FIXME: _Decimal32 and _Decimal64 are SSE. + // FIXME: _float128 and _Decimal128 are (SSE, SSEUp). + } else if (const EnumType *ET = Ty->getAs<EnumType>()) { + // Classify the underlying integer type. + classify(ET->getDecl()->getIntegerType(), Context, OffsetBase, Lo, Hi); + } else if (Ty->hasPointerRepresentation()) { + Current = Integer; + } else if (const VectorType *VT = Ty->getAs<VectorType>()) { + uint64_t Size = Context.getTypeSize(VT); + if (Size == 32) { + // gcc passes all <4 x char>, <2 x short>, <1 x int>, <1 x + // float> as integer. + Current = Integer; + + // If this type crosses an eightbyte boundary, it should be + // split. + uint64_t EB_Real = (OffsetBase) / 64; + uint64_t EB_Imag = (OffsetBase + Size - 1) / 64; + if (EB_Real != EB_Imag) + Hi = Lo; + } else if (Size == 64) { + // gcc passes <1 x double> in memory. :( + if (VT->getElementType()->isSpecificBuiltinType(BuiltinType::Double)) + return; + + // gcc passes <1 x long long> as INTEGER. + if (VT->getElementType()->isSpecificBuiltinType(BuiltinType::LongLong)) + Current = Integer; + else + Current = SSE; + + // If this type crosses an eightbyte boundary, it should be + // split. + if (OffsetBase && OffsetBase != 64) + Hi = Lo; + } else if (Size == 128) { + Lo = SSE; + Hi = SSEUp; + } + } else if (const ComplexType *CT = Ty->getAs<ComplexType>()) { + QualType ET = Context.getCanonicalType(CT->getElementType()); + + uint64_t Size = Context.getTypeSize(Ty); + if (ET->isIntegralType()) { + if (Size <= 64) + Current = Integer; + else if (Size <= 128) + Lo = Hi = Integer; + } else if (ET == Context.FloatTy) + Current = SSE; + else if (ET == Context.DoubleTy) + Lo = Hi = SSE; + else if (ET == Context.LongDoubleTy) + Current = ComplexX87; + + // If this complex type crosses an eightbyte boundary then it + // should be split. + uint64_t EB_Real = (OffsetBase) / 64; + uint64_t EB_Imag = (OffsetBase + Context.getTypeSize(ET)) / 64; + if (Hi == NoClass && EB_Real != EB_Imag) + Hi = Lo; + } else if (const ConstantArrayType *AT = Context.getAsConstantArrayType(Ty)) { + // Arrays are treated like structures. + + uint64_t Size = Context.getTypeSize(Ty); + + // AMD64-ABI 3.2.3p2: Rule 1. If the size of an object is larger + // than two eightbytes, ..., it has class MEMORY. + if (Size > 128) + return; + + // AMD64-ABI 3.2.3p2: Rule 1. If ..., or it contains unaligned + // fields, it has class MEMORY. + // + // Only need to check alignment of array base. + if (OffsetBase % Context.getTypeAlign(AT->getElementType())) + return; + + // Otherwise implement simplified merge. We could be smarter about + // this, but it isn't worth it and would be harder to verify. + Current = NoClass; + uint64_t EltSize = Context.getTypeSize(AT->getElementType()); + uint64_t ArraySize = AT->getSize().getZExtValue(); + for (uint64_t i=0, Offset=OffsetBase; i<ArraySize; ++i, Offset += EltSize) { + Class FieldLo, FieldHi; + classify(AT->getElementType(), Context, Offset, FieldLo, FieldHi); + Lo = merge(Lo, FieldLo); + Hi = merge(Hi, FieldHi); + if (Lo == Memory || Hi == Memory) + break; + } + + // Do post merger cleanup (see below). Only case we worry about is Memory. + if (Hi == Memory) + Lo = Memory; + assert((Hi != SSEUp || Lo == SSE) && "Invalid SSEUp array classification."); + } else if (const RecordType *RT = Ty->getAs<RecordType>()) { + uint64_t Size = Context.getTypeSize(Ty); + + // AMD64-ABI 3.2.3p2: Rule 1. If the size of an object is larger + // than two eightbytes, ..., it has class MEMORY. + if (Size > 128) + 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 (hasNonTrivialDestructorOrCopyConstructor(RT)) + return; + + const RecordDecl *RD = RT->getDecl(); + + // Assume variable sized types are passed in memory. + if (RD->hasFlexibleArrayMember()) + return; + + const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD); + + // Reset Lo class, this will be recomputed. + Current = NoClass; + + // If this is a C++ record, classify the bases first. + if (const CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(RD)) { + for (CXXRecordDecl::base_class_const_iterator i = CXXRD->bases_begin(), + e = CXXRD->bases_end(); i != e; ++i) { + assert(!i->isVirtual() && !i->getType()->isDependentType() && + "Unexpected base class!"); + const CXXRecordDecl *Base = + cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl()); + + // 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 + Layout.getBaseClassOffset(Base); + classify(i->getType(), Context, Offset, FieldLo, FieldHi); + Lo = merge(Lo, FieldLo); + Hi = merge(Hi, FieldHi); + if (Lo == Memory || Hi == Memory) + break; + } + + // If this record has no fields but isn't empty, classify as INTEGER. + if (RD->field_empty() && Size) + Current = Integer; + } + + // Classify the fields one at a time, merging the results. + unsigned idx = 0; + for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end(); + i != e; ++i, ++idx) { + uint64_t Offset = OffsetBase + Layout.getFieldOffset(idx); + bool BitField = i->isBitField(); + + // AMD64-ABI 3.2.3p2: Rule 1. If ..., or it contains unaligned + // fields, it has class MEMORY. + // + // Note, skip this test for bit-fields, see below. + if (!BitField && Offset % Context.getTypeAlign(i->getType())) { + Lo = Memory; + return; + } + + // 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; + + // Bit-fields require special handling, they do not force the + // structure to be passed in memory even if unaligned, and + // therefore they can straddle an eightbyte. + if (BitField) { + // Ignore padding bit-fields. + if (i->isUnnamedBitfield()) + continue; + + uint64_t Offset = OffsetBase + Layout.getFieldOffset(idx); + uint64_t Size = i->getBitWidth()->EvaluateAsInt(Context).getZExtValue(); + + uint64_t EB_Lo = Offset / 64; + uint64_t EB_Hi = (Offset + Size - 1) / 64; + FieldLo = FieldHi = NoClass; + if (EB_Lo) { + assert(EB_Hi == EB_Lo && "Invalid classification, type > 16 bytes."); + FieldLo = NoClass; + FieldHi = Integer; + } else { + FieldLo = Integer; + FieldHi = EB_Hi ? Integer : NoClass; + } + } else + classify(i->getType(), Context, Offset, FieldLo, FieldHi); + Lo = merge(Lo, FieldLo); + Hi = merge(Hi, FieldHi); + if (Lo == Memory || Hi == Memory) + break; + } + + // 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 SSEUP is not preceeded by SSE, it is converted to SSE. + + // The first of these conditions is guaranteed by how we implement + // the merge (just bail). + // + // The second condition occurs in the case of unions; for example + // union { _Complex double; unsigned; }. + if (Hi == Memory) + Lo = Memory; + if (Hi == SSEUp && Lo != SSE) + Hi = SSE; + } +} + +ABIArgInfo X86_64ABIInfo::getCoerceResult(QualType Ty, + const llvm::Type *CoerceTo, + ASTContext &Context) const { + if (CoerceTo == llvm::Type::getInt64Ty(CoerceTo->getContext())) { + // Integer and pointer types will end up in a general purpose + // register. + if (Ty->isIntegralType() || Ty->hasPointerRepresentation()) + return (Ty->isPromotableIntegerType() ? + ABIArgInfo::getExtend() : ABIArgInfo::getDirect()); + } else if (CoerceTo == llvm::Type::getDoubleTy(CoerceTo->getContext())) { + // FIXME: It would probably be better to make CGFunctionInfo only map using + // canonical types than to canonize here. + QualType CTy = Context.getCanonicalType(Ty); + + // Float and double end up in a single SSE reg. + if (CTy == Context.FloatTy || CTy == Context.DoubleTy) + return ABIArgInfo::getDirect(); + + } + + return ABIArgInfo::getCoerce(CoerceTo); +} + +ABIArgInfo X86_64ABIInfo::getIndirectResult(QualType Ty, + ASTContext &Context) const { + // If this is a scalar LLVM value then assume LLVM will pass it in the right + // place naturally. + if (!CodeGenFunction::hasAggregateLLVMType(Ty)) + return (Ty->isPromotableIntegerType() ? + ABIArgInfo::getExtend() : ABIArgInfo::getDirect()); + + bool ByVal = !isRecordWithNonTrivialDestructorOrCopyConstructor(Ty); + + // FIXME: Set alignment correctly. + return ABIArgInfo::getIndirect(0, ByVal); +} + +ABIArgInfo X86_64ABIInfo::classifyReturnType(QualType RetTy, + ASTContext &Context, + llvm::LLVMContext &VMContext) const { + // AMD64-ABI 3.2.3p4: Rule 1. Classify the return type with the + // classification algorithm. + X86_64ABIInfo::Class Lo, Hi; + classify(RetTy, Context, 0, Lo, Hi); + + // Check some invariants. + assert((Hi != Memory || Lo == Memory) && "Invalid memory classification."); + assert((Lo != NoClass || Hi == NoClass) && "Invalid null classification."); + assert((Hi != SSEUp || Lo == SSE) && "Invalid SSEUp classification."); + + const llvm::Type *ResType = 0; + switch (Lo) { + case NoClass: + return ABIArgInfo::getIgnore(); + + case SSEUp: + case X87Up: + assert(0 && "Invalid classification for lo word."); + + // AMD64-ABI 3.2.3p4: Rule 2. Types of class memory are returned via + // hidden argument. + case Memory: + return getIndirectResult(RetTy, Context); + + // 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 = llvm::Type::getInt64Ty(VMContext); 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 = llvm::Type::getDoubleTy(VMContext); 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 = llvm::Type::getX86_FP80Ty(VMContext); 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 ComplexX87: + assert(Hi == ComplexX87 && "Unexpected ComplexX87 classification."); + ResType = llvm::StructType::get(VMContext, llvm::Type::getX86_FP80Ty(VMContext), + llvm::Type::getX86_FP80Ty(VMContext), + NULL); + break; + } + + switch (Hi) { + // Memory was handled previously and X87 should + // never occur as a hi class. + case Memory: + case X87: + assert(0 && "Invalid classification for hi word."); + + case ComplexX87: // Previously handled. + case NoClass: break; + + case Integer: + ResType = llvm::StructType::get(VMContext, ResType, + llvm::Type::getInt64Ty(VMContext), NULL); + break; + case SSE: + ResType = llvm::StructType::get(VMContext, ResType, + llvm::Type::getDoubleTy(VMContext), NULL); + break; + + // AMD64-ABI 3.2.3p4: Rule 5. If the class is SSEUP, the eightbyte + // is passed in the upper half of the last used SSE register. + // + // SSEUP should always be preceeded by SSE, just widen. + case SSEUp: + assert(Lo == SSE && "Unexpected SSEUp classification."); + ResType = llvm::VectorType::get(llvm::Type::getDoubleTy(VMContext), 2); + 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 preceeded by X87, we don't need to do + // anything. However, in some cases with unions it may not be + // preceeded by X87. In such situations we follow gcc and pass the + // extra bits in an SSE reg. + if (Lo != X87) + ResType = llvm::StructType::get(VMContext, ResType, + llvm::Type::getDoubleTy(VMContext), NULL); + break; + } + + return getCoerceResult(RetTy, ResType, Context); +} + +ABIArgInfo X86_64ABIInfo::classifyArgumentType(QualType Ty, ASTContext &Context, + llvm::LLVMContext &VMContext, + unsigned &neededInt, + unsigned &neededSSE) const { + X86_64ABIInfo::Class Lo, Hi; + classify(Ty, Context, 0, Lo, Hi); + + // Check some invariants. + // FIXME: Enforce these by construction. + assert((Hi != Memory || Lo == Memory) && "Invalid memory classification."); + assert((Lo != NoClass || Hi == NoClass) && "Invalid null classification."); + assert((Hi != SSEUp || Lo == SSE) && "Invalid SSEUp classification."); + + neededInt = 0; + neededSSE = 0; + const llvm::Type *ResType = 0; + switch (Lo) { + case NoClass: + return ABIArgInfo::getIgnore(); + + // 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 ComplexX87: + return getIndirectResult(Ty, Context); + + case SSEUp: + case X87Up: + assert(0 && "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; + ResType = llvm::Type::getInt64Ty(VMContext); + 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: + ++neededSSE; + ResType = llvm::Type::getDoubleTy(VMContext); + break; + } + + switch (Hi) { + // Memory was handled previously, ComplexX87 and X87 should + // never occur as hi classes, and X87Up must be preceed by X87, + // which is passed in memory. + case Memory: + case X87: + case ComplexX87: + assert(0 && "Invalid classification for hi word."); + break; + + case NoClass: break; + case Integer: + ResType = llvm::StructType::get(VMContext, ResType, + llvm::Type::getInt64Ty(VMContext), NULL); + ++neededInt; + break; + + // X87Up generally doesn't occur here (long double is passed in + // memory), except in situations involving unions. + case X87Up: + case SSE: + ResType = llvm::StructType::get(VMContext, ResType, + llvm::Type::getDoubleTy(VMContext), NULL); + ++neededSSE; + 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. + case SSEUp: + assert(Lo == SSE && "Unexpected SSEUp classification."); + ResType = llvm::VectorType::get(llvm::Type::getDoubleTy(VMContext), 2); + break; + } + + return getCoerceResult(Ty, ResType, Context); +} + +void X86_64ABIInfo::computeInfo(CGFunctionInfo &FI, ASTContext &Context, + llvm::LLVMContext &VMContext) const { + FI.getReturnInfo() = classifyReturnType(FI.getReturnType(), + Context, VMContext); + + // Keep track of the number of assigned registers. + unsigned freeIntRegs = 6, freeSSERegs = 8; + + // If the return value is indirect, then the hidden argument is consuming one + // integer register. + if (FI.getReturnInfo().isIndirect()) + --freeIntRegs; + + // AMD64-ABI 3.2.3p3: Once arguments are classified, the registers + // get assigned (in left-to-right order) for passing as follows... + for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end(); + it != ie; ++it) { + unsigned neededInt, neededSSE; + it->info = classifyArgumentType(it->type, Context, VMContext, + neededInt, neededSSE); + + // AMD64-ABI 3.2.3p3: If there are no registers available for any + // eightbyte of an argument, the whole argument is passed on the + // stack. If registers have already been assigned for some + // eightbytes of such an argument, the assignments get reverted. + if (freeIntRegs >= neededInt && freeSSERegs >= neededSSE) { + freeIntRegs -= neededInt; + freeSSERegs -= neededSSE; + } else { + it->info = getIndirectResult(it->type, Context); + } + } +} + +static llvm::Value *EmitVAArgFromMemory(llvm::Value *VAListAddr, + QualType Ty, + CodeGenFunction &CGF) { + llvm::Value *overflow_arg_area_p = + CGF.Builder.CreateStructGEP(VAListAddr, 2, "overflow_arg_area_p"); + llvm::Value *overflow_arg_area = + CGF.Builder.CreateLoad(overflow_arg_area_p, "overflow_arg_area"); + + // AMD64-ABI 3.5.7p5: Step 7. Align l->overflow_arg_area upwards to a 16 + // byte boundary if alignment needed by type exceeds 8 byte boundary. + uint64_t Align = CGF.getContext().getTypeAlign(Ty) / 8; + if (Align > 8) { + // Note that we follow the ABI & gcc here, even though the type + // could in theory have an alignment greater than 16. This case + // shouldn't ever matter in practice. + + // overflow_arg_area = (overflow_arg_area + 15) & ~15; + llvm::Value *Offset = + llvm::ConstantInt::get(llvm::Type::getInt32Ty(CGF.getLLVMContext()), 15); + overflow_arg_area = CGF.Builder.CreateGEP(overflow_arg_area, Offset); + llvm::Value *AsInt = CGF.Builder.CreatePtrToInt(overflow_arg_area, + llvm::Type::getInt64Ty(CGF.getLLVMContext())); + llvm::Value *Mask = llvm::ConstantInt::get( + llvm::Type::getInt64Ty(CGF.getLLVMContext()), ~15LL); + overflow_arg_area = + CGF.Builder.CreateIntToPtr(CGF.Builder.CreateAnd(AsInt, Mask), + overflow_arg_area->getType(), + "overflow_arg_area.align"); + } + + // AMD64-ABI 3.5.7p5: Step 8. Fetch type from l->overflow_arg_area. + const llvm::Type *LTy = CGF.ConvertTypeForMem(Ty); + llvm::Value *Res = + CGF.Builder.CreateBitCast(overflow_arg_area, + llvm::PointerType::getUnqual(LTy)); + + // AMD64-ABI 3.5.7p5: Step 9. Set l->overflow_arg_area to: + // l->overflow_arg_area + sizeof(type). + // AMD64-ABI 3.5.7p5: Step 10. Align l->overflow_arg_area upwards to + // an 8 byte boundary. + + uint64_t SizeInBytes = (CGF.getContext().getTypeSize(Ty) + 7) / 8; + llvm::Value *Offset = + llvm::ConstantInt::get(llvm::Type::getInt32Ty(CGF.getLLVMContext()), + (SizeInBytes + 7) & ~7); + overflow_arg_area = CGF.Builder.CreateGEP(overflow_arg_area, Offset, + "overflow_arg_area.next"); + CGF.Builder.CreateStore(overflow_arg_area, overflow_arg_area_p); + + // AMD64-ABI 3.5.7p5: Step 11. Return the fetched type. + return Res; +} + +llvm::Value *X86_64ABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty, + CodeGenFunction &CGF) const { + llvm::LLVMContext &VMContext = CGF.getLLVMContext(); + const llvm::Type *i32Ty = llvm::Type::getInt32Ty(VMContext); + const llvm::Type *DoubleTy = llvm::Type::getDoubleTy(VMContext); + + // Assume that va_list type is correct; should be pointer to LLVM type: + // struct { + // i32 gp_offset; + // i32 fp_offset; + // i8* overflow_arg_area; + // i8* reg_save_area; + // }; + unsigned neededInt, neededSSE; + ABIArgInfo AI = classifyArgumentType(Ty, CGF.getContext(), VMContext, + neededInt, neededSSE); + + // AMD64-ABI 3.5.7p5: Step 1. Determine whether type may be passed + // in the registers. If not go to step 7. + if (!neededInt && !neededSSE) + return EmitVAArgFromMemory(VAListAddr, Ty, CGF); + + // AMD64-ABI 3.5.7p5: Step 2. Compute num_gp to hold the number of + // general purpose registers needed to pass type and num_fp to hold + // the number of floating point registers needed. + + // AMD64-ABI 3.5.7p5: Step 3. Verify whether arguments fit into + // registers. In the case: l->gp_offset > 48 - num_gp * 8 or + // l->fp_offset > 304 - num_fp * 16 go to step 7. + // + // NOTE: 304 is a typo, there are (6 * 8 + 8 * 16) = 176 bytes of + // register save space). + + llvm::Value *InRegs = 0; + llvm::Value *gp_offset_p = 0, *gp_offset = 0; + llvm::Value *fp_offset_p = 0, *fp_offset = 0; + if (neededInt) { + gp_offset_p = CGF.Builder.CreateStructGEP(VAListAddr, 0, "gp_offset_p"); + gp_offset = CGF.Builder.CreateLoad(gp_offset_p, "gp_offset"); + InRegs = + CGF.Builder.CreateICmpULE(gp_offset, + llvm::ConstantInt::get(i32Ty, + 48 - neededInt * 8), + "fits_in_gp"); + } + + if (neededSSE) { + fp_offset_p = CGF.Builder.CreateStructGEP(VAListAddr, 1, "fp_offset_p"); + fp_offset = CGF.Builder.CreateLoad(fp_offset_p, "fp_offset"); + llvm::Value *FitsInFP = + CGF.Builder.CreateICmpULE(fp_offset, + llvm::ConstantInt::get(i32Ty, + 176 - neededSSE * 16), + "fits_in_fp"); + InRegs = InRegs ? CGF.Builder.CreateAnd(InRegs, FitsInFP) : FitsInFP; + } + + llvm::BasicBlock *InRegBlock = CGF.createBasicBlock("vaarg.in_reg"); + llvm::BasicBlock *InMemBlock = CGF.createBasicBlock("vaarg.in_mem"); + llvm::BasicBlock *ContBlock = CGF.createBasicBlock("vaarg.end"); + CGF.Builder.CreateCondBr(InRegs, InRegBlock, InMemBlock); + + // Emit code to load the value if it was passed in registers. + + CGF.EmitBlock(InRegBlock); + + // AMD64-ABI 3.5.7p5: Step 4. Fetch type from l->reg_save_area with + // an offset of l->gp_offset and/or l->fp_offset. This may require + // copying to a temporary location in case the parameter is passed + // in different register classes or requires an alignment greater + // than 8 for general purpose registers and 16 for XMM registers. + // + // FIXME: This really results in shameful code when we end up needing to + // collect arguments from different places; often what should result in a + // simple assembling of a structure from scattered addresses has many more + // loads than necessary. Can we clean this up? + const llvm::Type *LTy = CGF.ConvertTypeForMem(Ty); + llvm::Value *RegAddr = + CGF.Builder.CreateLoad(CGF.Builder.CreateStructGEP(VAListAddr, 3), + "reg_save_area"); + if (neededInt && neededSSE) { + // FIXME: Cleanup. + assert(AI.isCoerce() && "Unexpected ABI info for mixed regs"); + const llvm::StructType *ST = cast<llvm::StructType>(AI.getCoerceToType()); + llvm::Value *Tmp = CGF.CreateTempAlloca(ST); + assert(ST->getNumElements() == 2 && "Unexpected ABI info for mixed regs"); + const llvm::Type *TyLo = ST->getElementType(0); + const llvm::Type *TyHi = ST->getElementType(1); + assert((TyLo->isFloatingPoint() ^ TyHi->isFloatingPoint()) && + "Unexpected ABI info for mixed regs"); + const llvm::Type *PTyLo = llvm::PointerType::getUnqual(TyLo); + const llvm::Type *PTyHi = llvm::PointerType::getUnqual(TyHi); + llvm::Value *GPAddr = CGF.Builder.CreateGEP(RegAddr, gp_offset); + llvm::Value *FPAddr = CGF.Builder.CreateGEP(RegAddr, fp_offset); + llvm::Value *RegLoAddr = TyLo->isFloatingPoint() ? FPAddr : GPAddr; + llvm::Value *RegHiAddr = TyLo->isFloatingPoint() ? GPAddr : FPAddr; + llvm::Value *V = + CGF.Builder.CreateLoad(CGF.Builder.CreateBitCast(RegLoAddr, PTyLo)); + CGF.Builder.CreateStore(V, CGF.Builder.CreateStructGEP(Tmp, 0)); + V = CGF.Builder.CreateLoad(CGF.Builder.CreateBitCast(RegHiAddr, PTyHi)); + CGF.Builder.CreateStore(V, CGF.Builder.CreateStructGEP(Tmp, 1)); + + RegAddr = CGF.Builder.CreateBitCast(Tmp, + llvm::PointerType::getUnqual(LTy)); + } else if (neededInt) { + RegAddr = CGF.Builder.CreateGEP(RegAddr, gp_offset); + RegAddr = CGF.Builder.CreateBitCast(RegAddr, + llvm::PointerType::getUnqual(LTy)); + } else { + if (neededSSE == 1) { + RegAddr = CGF.Builder.CreateGEP(RegAddr, fp_offset); + RegAddr = CGF.Builder.CreateBitCast(RegAddr, + llvm::PointerType::getUnqual(LTy)); + } else { + assert(neededSSE == 2 && "Invalid number of needed registers!"); + // SSE registers are spaced 16 bytes apart in the register save + // area, we need to collect the two eightbytes together. + llvm::Value *RegAddrLo = CGF.Builder.CreateGEP(RegAddr, fp_offset); + llvm::Value *RegAddrHi = + CGF.Builder.CreateGEP(RegAddrLo, + llvm::ConstantInt::get(i32Ty, 16)); + const llvm::Type *DblPtrTy = + llvm::PointerType::getUnqual(DoubleTy); + const llvm::StructType *ST = llvm::StructType::get(VMContext, DoubleTy, + DoubleTy, NULL); + llvm::Value *V, *Tmp = CGF.CreateTempAlloca(ST); + V = CGF.Builder.CreateLoad(CGF.Builder.CreateBitCast(RegAddrLo, + DblPtrTy)); + CGF.Builder.CreateStore(V, CGF.Builder.CreateStructGEP(Tmp, 0)); + V = CGF.Builder.CreateLoad(CGF.Builder.CreateBitCast(RegAddrHi, + DblPtrTy)); + CGF.Builder.CreateStore(V, CGF.Builder.CreateStructGEP(Tmp, 1)); + RegAddr = CGF.Builder.CreateBitCast(Tmp, + llvm::PointerType::getUnqual(LTy)); + } + } + + // AMD64-ABI 3.5.7p5: Step 5. Set: + // l->gp_offset = l->gp_offset + num_gp * 8 + // l->fp_offset = l->fp_offset + num_fp * 16. + if (neededInt) { + llvm::Value *Offset = llvm::ConstantInt::get(i32Ty, neededInt * 8); + CGF.Builder.CreateStore(CGF.Builder.CreateAdd(gp_offset, Offset), + gp_offset_p); + } + if (neededSSE) { + llvm::Value *Offset = llvm::ConstantInt::get(i32Ty, neededSSE * 16); + CGF.Builder.CreateStore(CGF.Builder.CreateAdd(fp_offset, Offset), + fp_offset_p); + } + CGF.EmitBranch(ContBlock); + + // Emit code to load the value if it was passed in memory. + + CGF.EmitBlock(InMemBlock); + llvm::Value *MemAddr = EmitVAArgFromMemory(VAListAddr, Ty, CGF); + + // Return the appropriate result. + + CGF.EmitBlock(ContBlock); + llvm::PHINode *ResAddr = CGF.Builder.CreatePHI(RegAddr->getType(), + "vaarg.addr"); + ResAddr->reserveOperandSpace(2); + ResAddr->addIncoming(RegAddr, InRegBlock); + ResAddr->addIncoming(MemAddr, InMemBlock); + + return ResAddr; +} + +// PIC16 ABI Implementation + +namespace { + +class PIC16ABIInfo : public ABIInfo { + ABIArgInfo classifyReturnType(QualType RetTy, + ASTContext &Context, + llvm::LLVMContext &VMContext) const; + + ABIArgInfo classifyArgumentType(QualType RetTy, + ASTContext &Context, + llvm::LLVMContext &VMContext) const; + + virtual void computeInfo(CGFunctionInfo &FI, ASTContext &Context, + llvm::LLVMContext &VMContext) const { + FI.getReturnInfo() = classifyReturnType(FI.getReturnType(), Context, + VMContext); + for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end(); + it != ie; ++it) + it->info = classifyArgumentType(it->type, Context, VMContext); + } + + virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty, + CodeGenFunction &CGF) const; +}; + +class PIC16TargetCodeGenInfo : public TargetCodeGenInfo { +public: + PIC16TargetCodeGenInfo():TargetCodeGenInfo(new PIC16ABIInfo()) {}; +}; + +} + +ABIArgInfo PIC16ABIInfo::classifyReturnType(QualType RetTy, + ASTContext &Context, + llvm::LLVMContext &VMContext) const { + if (RetTy->isVoidType()) { + return ABIArgInfo::getIgnore(); + } else { + return ABIArgInfo::getDirect(); + } +} + +ABIArgInfo PIC16ABIInfo::classifyArgumentType(QualType Ty, + ASTContext &Context, + llvm::LLVMContext &VMContext) const { + return ABIArgInfo::getDirect(); +} + +llvm::Value *PIC16ABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty, + CodeGenFunction &CGF) const { + return 0; +} + +// ARM ABI Implementation + +namespace { + +class ARMABIInfo : public ABIInfo { +public: + enum ABIKind { + APCS = 0, + AAPCS = 1, + AAPCS_VFP + }; + +private: + ABIKind Kind; + +public: + ARMABIInfo(ABIKind _Kind) : Kind(_Kind) {} + +private: + ABIKind getABIKind() const { return Kind; } + + ABIArgInfo classifyReturnType(QualType RetTy, + ASTContext &Context, + llvm::LLVMContext &VMCOntext) const; + + ABIArgInfo classifyArgumentType(QualType RetTy, + ASTContext &Context, + llvm::LLVMContext &VMContext) const; + + virtual void computeInfo(CGFunctionInfo &FI, ASTContext &Context, + llvm::LLVMContext &VMContext) const; + + virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty, + CodeGenFunction &CGF) const; +}; + +class ARMTargetCodeGenInfo : public TargetCodeGenInfo { +public: + ARMTargetCodeGenInfo(ARMABIInfo::ABIKind K) + :TargetCodeGenInfo(new ARMABIInfo(K)) {}; +}; + +} + +void ARMABIInfo::computeInfo(CGFunctionInfo &FI, ASTContext &Context, + llvm::LLVMContext &VMContext) const { + FI.getReturnInfo() = classifyReturnType(FI.getReturnType(), Context, + VMContext); + for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end(); + it != ie; ++it) { + it->info = classifyArgumentType(it->type, Context, VMContext); + } + + // ARM always overrides the calling convention. + switch (getABIKind()) { + case APCS: + FI.setEffectiveCallingConvention(llvm::CallingConv::ARM_APCS); + break; + + case AAPCS: + FI.setEffectiveCallingConvention(llvm::CallingConv::ARM_AAPCS); + break; + + case AAPCS_VFP: + FI.setEffectiveCallingConvention(llvm::CallingConv::ARM_AAPCS_VFP); + break; + } +} + +ABIArgInfo ARMABIInfo::classifyArgumentType(QualType Ty, + ASTContext &Context, + llvm::LLVMContext &VMContext) const { + if (!CodeGenFunction::hasAggregateLLVMType(Ty)) + return (Ty->isPromotableIntegerType() ? + ABIArgInfo::getExtend() : ABIArgInfo::getDirect()); + + // Ignore empty records. + if (isEmptyRecord(Context, Ty, true)) + return ABIArgInfo::getIgnore(); + + // FIXME: This is kind of nasty... but there isn't much choice because the ARM + // backend doesn't support byval. + // FIXME: This doesn't handle alignment > 64 bits. + const llvm::Type* ElemTy; + unsigned SizeRegs; + if (Context.getTypeAlign(Ty) > 32) { + ElemTy = llvm::Type::getInt64Ty(VMContext); + SizeRegs = (Context.getTypeSize(Ty) + 63) / 64; + } else { + ElemTy = llvm::Type::getInt32Ty(VMContext); + SizeRegs = (Context.getTypeSize(Ty) + 31) / 32; + } + std::vector<const llvm::Type*> LLVMFields; + LLVMFields.push_back(llvm::ArrayType::get(ElemTy, SizeRegs)); + const llvm::Type* STy = llvm::StructType::get(VMContext, LLVMFields, true); + return ABIArgInfo::getCoerce(STy); +} + +static bool isIntegerLikeType(QualType Ty, + ASTContext &Context, + llvm::LLVMContext &VMContext) { + // APCS, C Language Calling Conventions, Non-Simple Return Values: A structure + // is called integer-like if its size is less than or equal to one word, and + // the offset of each of its addressable sub-fields is zero. + + uint64_t Size = Context.getTypeSize(Ty); + + // Check that the type fits in a word. + if (Size > 32) + return false; + + // FIXME: Handle vector types! + if (Ty->isVectorType()) + return false; + + // Float types are never treated as "integer like". + if (Ty->isRealFloatingType()) + return false; + + // If this is a builtin or pointer type then it is ok. + if (Ty->getAs<BuiltinType>() || Ty->isPointerType()) + return true; + + // Complex types "should" be ok by the definition above, but they are not. + if (Ty->isAnyComplexType()) + return false; + + // Single element and zero sized arrays should be allowed, by the definition + // above, but they are not. + + // Otherwise, it must be a record type. + const RecordType *RT = Ty->getAs<RecordType>(); + if (!RT) return false; + + // Ignore records with flexible arrays. + const RecordDecl *RD = RT->getDecl(); + if (RD->hasFlexibleArrayMember()) + return false; + + // Check that all sub-fields are at offset 0, and are themselves "integer + // like". + const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD); + + bool HadField = false; + unsigned idx = 0; + for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end(); + i != e; ++i, ++idx) { + const FieldDecl *FD = *i; + + // Check if this field is at offset 0. + uint64_t Offset = Layout.getFieldOffset(idx); + if (Offset != 0) { + // Allow padding bit-fields, but only if they are all at the end of the + // structure (despite the wording above, this matches gcc). + if (FD->isBitField() && + !FD->getBitWidth()->EvaluateAsInt(Context).getZExtValue()) { + for (; i != e; ++i) + if (!i->isBitField() || + i->getBitWidth()->EvaluateAsInt(Context).getZExtValue()) + return false; + + // All remaining fields are padding, allow this. + return true; + } + + return false; + } + + if (!isIntegerLikeType(FD->getType(), Context, VMContext)) + return false; + + // Only allow at most one field in a structure. Again this doesn't match the + // wording above, but follows gcc. + if (!RD->isUnion()) { + if (HadField) + return false; + + HadField = true; + } + } + + return true; +} + +ABIArgInfo ARMABIInfo::classifyReturnType(QualType RetTy, + ASTContext &Context, + llvm::LLVMContext &VMContext) const { + if (RetTy->isVoidType()) + return ABIArgInfo::getIgnore(); + + if (!CodeGenFunction::hasAggregateLLVMType(RetTy)) + return (RetTy->isPromotableIntegerType() ? + ABIArgInfo::getExtend() : ABIArgInfo::getDirect()); + + // Are we following APCS? + if (getABIKind() == APCS) { + if (isEmptyRecord(Context, RetTy, false)) + return ABIArgInfo::getIgnore(); + + // Integer like structures are returned in r0. + if (isIntegerLikeType(RetTy, Context, VMContext)) { + // Return in the smallest viable integer type. + uint64_t Size = Context.getTypeSize(RetTy); + if (Size <= 8) + return ABIArgInfo::getCoerce(llvm::Type::getInt8Ty(VMContext)); + if (Size <= 16) + return ABIArgInfo::getCoerce(llvm::Type::getInt16Ty(VMContext)); + return ABIArgInfo::getCoerce(llvm::Type::getInt32Ty(VMContext)); + } + + // Otherwise return in memory. + return ABIArgInfo::getIndirect(0); + } + + // Otherwise this is an AAPCS variant. + + if (isEmptyRecord(Context, RetTy, true)) + return ABIArgInfo::getIgnore(); + + // Aggregates <= 4 bytes are returned in r0; other aggregates + // are returned indirectly. + uint64_t Size = Context.getTypeSize(RetTy); + if (Size <= 32) { + // Return in the smallest viable integer type. + if (Size <= 8) + return ABIArgInfo::getCoerce(llvm::Type::getInt8Ty(VMContext)); + if (Size <= 16) + return ABIArgInfo::getCoerce(llvm::Type::getInt16Ty(VMContext)); + return ABIArgInfo::getCoerce(llvm::Type::getInt32Ty(VMContext)); + } + + return ABIArgInfo::getIndirect(0); +} + +llvm::Value *ARMABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty, + CodeGenFunction &CGF) const { + // FIXME: Need to handle alignment + const llvm::Type *BP = llvm::Type::getInt8PtrTy(CGF.getLLVMContext()); + const llvm::Type *BPP = llvm::PointerType::getUnqual(BP); + + CGBuilderTy &Builder = CGF.Builder; + llvm::Value *VAListAddrAsBPP = Builder.CreateBitCast(VAListAddr, BPP, + "ap"); + llvm::Value *Addr = Builder.CreateLoad(VAListAddrAsBPP, "ap.cur"); + llvm::Type *PTy = + llvm::PointerType::getUnqual(CGF.ConvertType(Ty)); + llvm::Value *AddrTyped = Builder.CreateBitCast(Addr, PTy); + + uint64_t Offset = + llvm::RoundUpToAlignment(CGF.getContext().getTypeSize(Ty) / 8, 4); + llvm::Value *NextAddr = + Builder.CreateGEP(Addr, llvm::ConstantInt::get( + llvm::Type::getInt32Ty(CGF.getLLVMContext()), Offset), + "ap.next"); + Builder.CreateStore(NextAddr, VAListAddrAsBPP); + + return AddrTyped; +} + +ABIArgInfo DefaultABIInfo::classifyReturnType(QualType RetTy, + ASTContext &Context, + llvm::LLVMContext &VMContext) const { + if (RetTy->isVoidType()) { + return ABIArgInfo::getIgnore(); + } else if (CodeGenFunction::hasAggregateLLVMType(RetTy)) { + return ABIArgInfo::getIndirect(0); + } else { + return (RetTy->isPromotableIntegerType() ? + ABIArgInfo::getExtend() : ABIArgInfo::getDirect()); + } +} + +// SystemZ ABI Implementation + +namespace { + +class SystemZABIInfo : public ABIInfo { + bool isPromotableIntegerType(QualType Ty) const; + + ABIArgInfo classifyReturnType(QualType RetTy, ASTContext &Context, + llvm::LLVMContext &VMContext) const; + + ABIArgInfo classifyArgumentType(QualType RetTy, ASTContext &Context, + llvm::LLVMContext &VMContext) const; + + virtual void computeInfo(CGFunctionInfo &FI, ASTContext &Context, + llvm::LLVMContext &VMContext) const { + FI.getReturnInfo() = classifyReturnType(FI.getReturnType(), + Context, VMContext); + for (CGFunctionInfo::arg_iterator it = FI.arg_begin(), ie = FI.arg_end(); + it != ie; ++it) + it->info = classifyArgumentType(it->type, Context, VMContext); + } + + virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty, + CodeGenFunction &CGF) const; +}; + +class SystemZTargetCodeGenInfo : public TargetCodeGenInfo { +public: + SystemZTargetCodeGenInfo():TargetCodeGenInfo(new SystemZABIInfo()) {}; +}; + +} + +bool SystemZABIInfo::isPromotableIntegerType(QualType Ty) const { + // SystemZ ABI requires all 8, 16 and 32 bit quantities to be extended. + if (const BuiltinType *BT = Ty->getAs<BuiltinType>()) + switch (BT->getKind()) { + case BuiltinType::Bool: + case BuiltinType::Char_S: + case BuiltinType::Char_U: + case BuiltinType::SChar: + case BuiltinType::UChar: + case BuiltinType::Short: + case BuiltinType::UShort: + case BuiltinType::Int: + case BuiltinType::UInt: + return true; + default: + return false; + } + return false; +} + +llvm::Value *SystemZABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty, + CodeGenFunction &CGF) const { + // FIXME: Implement + return 0; +} + + +ABIArgInfo SystemZABIInfo::classifyReturnType(QualType RetTy, + ASTContext &Context, + llvm::LLVMContext &VMContext) const { + if (RetTy->isVoidType()) { + return ABIArgInfo::getIgnore(); + } else if (CodeGenFunction::hasAggregateLLVMType(RetTy)) { + return ABIArgInfo::getIndirect(0); + } else { + return (isPromotableIntegerType(RetTy) ? + ABIArgInfo::getExtend() : ABIArgInfo::getDirect()); + } +} + +ABIArgInfo SystemZABIInfo::classifyArgumentType(QualType Ty, + ASTContext &Context, + llvm::LLVMContext &VMContext) const { + if (CodeGenFunction::hasAggregateLLVMType(Ty)) { + return ABIArgInfo::getIndirect(0); + } else { + return (isPromotableIntegerType(Ty) ? + ABIArgInfo::getExtend() : ABIArgInfo::getDirect()); + } +} + +// MSP430 ABI Implementation + +namespace { + +class MSP430TargetCodeGenInfo : public TargetCodeGenInfo { +public: + MSP430TargetCodeGenInfo():TargetCodeGenInfo(new DefaultABIInfo()) {}; + void SetTargetAttributes(const Decl *D, llvm::GlobalValue *GV, + CodeGen::CodeGenModule &M) const; +}; + +} + +void MSP430TargetCodeGenInfo::SetTargetAttributes(const Decl *D, + llvm::GlobalValue *GV, + CodeGen::CodeGenModule &M) const { + if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { + if (const MSP430InterruptAttr *attr = FD->getAttr<MSP430InterruptAttr>()) { + // Handle 'interrupt' attribute: + llvm::Function *F = cast<llvm::Function>(GV); + + // Step 1: Set ISR calling convention. + F->setCallingConv(llvm::CallingConv::MSP430_INTR); + + // Step 2: Add attributes goodness. + F->addFnAttr(llvm::Attribute::NoInline); + + // Step 3: Emit ISR vector alias. + unsigned Num = attr->getNumber() + 0xffe0; + new llvm::GlobalAlias(GV->getType(), llvm::Function::ExternalLinkage, + "vector_" + + llvm::LowercaseString(llvm::utohexstr(Num)), + GV, &M.getModule()); + } + } +} + +const TargetCodeGenInfo &CodeGenModule::getTargetCodeGenInfo() const { + if (TheTargetCodeGenInfo) + return *TheTargetCodeGenInfo; + + // For now we just cache the TargetCodeGenInfo in CodeGenModule and don't + // free it. + + const llvm::Triple &Triple(getContext().Target.getTriple()); + switch (Triple.getArch()) { + default: + return *(TheTargetCodeGenInfo = new DefaultTargetCodeGenInfo); + + case llvm::Triple::arm: + case llvm::Triple::thumb: + // FIXME: We want to know the float calling convention as well. + if (strcmp(getContext().Target.getABI(), "apcs-gnu") == 0) + return *(TheTargetCodeGenInfo = + new ARMTargetCodeGenInfo(ARMABIInfo::APCS)); + + return *(TheTargetCodeGenInfo = + new ARMTargetCodeGenInfo(ARMABIInfo::AAPCS)); + + case llvm::Triple::pic16: + return *(TheTargetCodeGenInfo = new PIC16TargetCodeGenInfo()); + + case llvm::Triple::systemz: + return *(TheTargetCodeGenInfo = new SystemZTargetCodeGenInfo()); + + case llvm::Triple::msp430: + return *(TheTargetCodeGenInfo = new MSP430TargetCodeGenInfo()); + + case llvm::Triple::x86: + switch (Triple.getOS()) { + case llvm::Triple::Darwin: + return *(TheTargetCodeGenInfo = + new X86_32TargetCodeGenInfo(Context, true, true)); + case llvm::Triple::Cygwin: + case llvm::Triple::MinGW32: + case llvm::Triple::MinGW64: + case llvm::Triple::AuroraUX: + case llvm::Triple::DragonFly: + case llvm::Triple::FreeBSD: + case llvm::Triple::OpenBSD: + return *(TheTargetCodeGenInfo = + new X86_32TargetCodeGenInfo(Context, false, true)); + + default: + return *(TheTargetCodeGenInfo = + new X86_32TargetCodeGenInfo(Context, false, false)); + } + + case llvm::Triple::x86_64: + return *(TheTargetCodeGenInfo = new X86_64TargetCodeGenInfo()); + } +} |