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Diffstat (limited to 'lib/IR/Function.cpp')
-rw-r--r-- | lib/IR/Function.cpp | 670 |
1 files changed, 670 insertions, 0 deletions
diff --git a/lib/IR/Function.cpp b/lib/IR/Function.cpp new file mode 100644 index 0000000000..cd35aff161 --- /dev/null +++ b/lib/IR/Function.cpp @@ -0,0 +1,670 @@ +//===-- Function.cpp - Implement the Global object classes ----------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file implements the Function class for the IR library. +// +//===----------------------------------------------------------------------===// + +#include "llvm/IR/Function.h" +#include "SymbolTableListTraitsImpl.h" +#include "llvm/ADT/DenseMap.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/ADT/StringExtras.h" +#include "llvm/CodeGen/ValueTypes.h" +#include "llvm/IR/DerivedTypes.h" +#include "llvm/IR/IntrinsicInst.h" +#include "llvm/IR/LLVMContext.h" +#include "llvm/IR/Module.h" +#include "llvm/Support/CallSite.h" +#include "llvm/Support/InstIterator.h" +#include "llvm/Support/LeakDetector.h" +#include "llvm/Support/ManagedStatic.h" +#include "llvm/Support/RWMutex.h" +#include "llvm/Support/StringPool.h" +#include "llvm/Support/Threading.h" +using namespace llvm; + +// Explicit instantiations of SymbolTableListTraits since some of the methods +// are not in the public header file... +template class llvm::SymbolTableListTraits<Argument, Function>; +template class llvm::SymbolTableListTraits<BasicBlock, Function>; + +//===----------------------------------------------------------------------===// +// Argument Implementation +//===----------------------------------------------------------------------===// + +void Argument::anchor() { } + +Argument::Argument(Type *Ty, const Twine &Name, Function *Par) + : Value(Ty, Value::ArgumentVal) { + Parent = 0; + + // Make sure that we get added to a function + LeakDetector::addGarbageObject(this); + + if (Par) + Par->getArgumentList().push_back(this); + setName(Name); +} + +void Argument::setParent(Function *parent) { + if (getParent()) + LeakDetector::addGarbageObject(this); + Parent = parent; + if (getParent()) + LeakDetector::removeGarbageObject(this); +} + +/// getArgNo - Return the index of this formal argument in its containing +/// function. For example in "void foo(int a, float b)" a is 0 and b is 1. +unsigned Argument::getArgNo() const { + const Function *F = getParent(); + assert(F && "Argument is not in a function"); + + Function::const_arg_iterator AI = F->arg_begin(); + unsigned ArgIdx = 0; + for (; &*AI != this; ++AI) + ++ArgIdx; + + return ArgIdx; +} + +/// hasByValAttr - Return true if this argument has the byval attribute on it +/// in its containing function. +bool Argument::hasByValAttr() const { + if (!getType()->isPointerTy()) return false; + return getParent()->getAttributes(). + hasAttribute(getArgNo()+1, Attribute::ByVal); +} + +unsigned Argument::getParamAlignment() const { + assert(getType()->isPointerTy() && "Only pointers have alignments"); + return getParent()->getParamAlignment(getArgNo()+1); + +} + +/// hasNestAttr - Return true if this argument has the nest attribute on +/// it in its containing function. +bool Argument::hasNestAttr() const { + if (!getType()->isPointerTy()) return false; + return getParent()->getAttributes(). + hasAttribute(getArgNo()+1, Attribute::Nest); +} + +/// hasNoAliasAttr - Return true if this argument has the noalias attribute on +/// it in its containing function. +bool Argument::hasNoAliasAttr() const { + if (!getType()->isPointerTy()) return false; + return getParent()->getAttributes(). + hasAttribute(getArgNo()+1, Attribute::NoAlias); +} + +/// hasNoCaptureAttr - Return true if this argument has the nocapture attribute +/// on it in its containing function. +bool Argument::hasNoCaptureAttr() const { + if (!getType()->isPointerTy()) return false; + return getParent()->getAttributes(). + hasAttribute(getArgNo()+1, Attribute::NoCapture); +} + +/// hasSRetAttr - Return true if this argument has the sret attribute on +/// it in its containing function. +bool Argument::hasStructRetAttr() const { + if (!getType()->isPointerTy()) return false; + if (this != getParent()->arg_begin()) + return false; // StructRet param must be first param + return getParent()->getAttributes(). + hasAttribute(1, Attribute::StructRet); +} + +/// addAttr - Add a Attribute to an argument +void Argument::addAttr(Attribute attr) { + getParent()->addAttribute(getArgNo() + 1, attr); +} + +/// removeAttr - Remove a Attribute from an argument +void Argument::removeAttr(Attribute attr) { + getParent()->removeAttribute(getArgNo() + 1, attr); +} + + +//===----------------------------------------------------------------------===// +// Helper Methods in Function +//===----------------------------------------------------------------------===// + +LLVMContext &Function::getContext() const { + return getType()->getContext(); +} + +FunctionType *Function::getFunctionType() const { + return cast<FunctionType>(getType()->getElementType()); +} + +bool Function::isVarArg() const { + return getFunctionType()->isVarArg(); +} + +Type *Function::getReturnType() const { + return getFunctionType()->getReturnType(); +} + +void Function::removeFromParent() { + getParent()->getFunctionList().remove(this); +} + +void Function::eraseFromParent() { + getParent()->getFunctionList().erase(this); +} + +//===----------------------------------------------------------------------===// +// Function Implementation +//===----------------------------------------------------------------------===// + +Function::Function(FunctionType *Ty, LinkageTypes Linkage, + const Twine &name, Module *ParentModule) + : GlobalValue(PointerType::getUnqual(Ty), + Value::FunctionVal, 0, 0, Linkage, name) { + assert(FunctionType::isValidReturnType(getReturnType()) && + "invalid return type"); + SymTab = new ValueSymbolTable(); + + // If the function has arguments, mark them as lazily built. + if (Ty->getNumParams()) + setValueSubclassData(1); // Set the "has lazy arguments" bit. + + // Make sure that we get added to a function + LeakDetector::addGarbageObject(this); + + if (ParentModule) + ParentModule->getFunctionList().push_back(this); + + // Ensure intrinsics have the right parameter attributes. + if (unsigned IID = getIntrinsicID()) + setAttributes(Intrinsic::getAttributes(getContext(), Intrinsic::ID(IID))); + +} + +Function::~Function() { + dropAllReferences(); // After this it is safe to delete instructions. + + // Delete all of the method arguments and unlink from symbol table... + ArgumentList.clear(); + delete SymTab; + + // Remove the function from the on-the-side GC table. + clearGC(); +} + +void Function::BuildLazyArguments() const { + // Create the arguments vector, all arguments start out unnamed. + FunctionType *FT = getFunctionType(); + for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i) { + assert(!FT->getParamType(i)->isVoidTy() && + "Cannot have void typed arguments!"); + ArgumentList.push_back(new Argument(FT->getParamType(i))); + } + + // Clear the lazy arguments bit. + unsigned SDC = getSubclassDataFromValue(); + const_cast<Function*>(this)->setValueSubclassData(SDC &= ~1); +} + +size_t Function::arg_size() const { + return getFunctionType()->getNumParams(); +} +bool Function::arg_empty() const { + return getFunctionType()->getNumParams() == 0; +} + +void Function::setParent(Module *parent) { + if (getParent()) + LeakDetector::addGarbageObject(this); + Parent = parent; + if (getParent()) + LeakDetector::removeGarbageObject(this); +} + +// dropAllReferences() - This function causes all the subinstructions to "let +// go" of all references that they are maintaining. This allows one to +// 'delete' a whole class at a time, even though there may be circular +// references... first all references are dropped, and all use counts go to +// zero. Then everything is deleted for real. Note that no operations are +// valid on an object that has "dropped all references", except operator +// delete. +// +void Function::dropAllReferences() { + for (iterator I = begin(), E = end(); I != E; ++I) + I->dropAllReferences(); + + // Delete all basic blocks. They are now unused, except possibly by + // blockaddresses, but BasicBlock's destructor takes care of those. + while (!BasicBlocks.empty()) + BasicBlocks.begin()->eraseFromParent(); +} + +void Function::addAttribute(unsigned i, Attribute attr) { + AttributeSet PAL = getAttributes(); + PAL = PAL.addAttr(getContext(), i, attr); + setAttributes(PAL); +} + +void Function::removeAttribute(unsigned i, Attribute attr) { + AttributeSet PAL = getAttributes(); + PAL = PAL.removeAttr(getContext(), i, attr); + setAttributes(PAL); +} + +// Maintain the GC name for each function in an on-the-side table. This saves +// allocating an additional word in Function for programs which do not use GC +// (i.e., most programs) at the cost of increased overhead for clients which do +// use GC. +static DenseMap<const Function*,PooledStringPtr> *GCNames; +static StringPool *GCNamePool; +static ManagedStatic<sys::SmartRWMutex<true> > GCLock; + +bool Function::hasGC() const { + sys::SmartScopedReader<true> Reader(*GCLock); + return GCNames && GCNames->count(this); +} + +const char *Function::getGC() const { + assert(hasGC() && "Function has no collector"); + sys::SmartScopedReader<true> Reader(*GCLock); + return *(*GCNames)[this]; +} + +void Function::setGC(const char *Str) { + sys::SmartScopedWriter<true> Writer(*GCLock); + if (!GCNamePool) + GCNamePool = new StringPool(); + if (!GCNames) + GCNames = new DenseMap<const Function*,PooledStringPtr>(); + (*GCNames)[this] = GCNamePool->intern(Str); +} + +void Function::clearGC() { + sys::SmartScopedWriter<true> Writer(*GCLock); + if (GCNames) { + GCNames->erase(this); + if (GCNames->empty()) { + delete GCNames; + GCNames = 0; + if (GCNamePool->empty()) { + delete GCNamePool; + GCNamePool = 0; + } + } + } +} + +/// copyAttributesFrom - copy all additional attributes (those not needed to +/// create a Function) from the Function Src to this one. +void Function::copyAttributesFrom(const GlobalValue *Src) { + assert(isa<Function>(Src) && "Expected a Function!"); + GlobalValue::copyAttributesFrom(Src); + const Function *SrcF = cast<Function>(Src); + setCallingConv(SrcF->getCallingConv()); + setAttributes(SrcF->getAttributes()); + if (SrcF->hasGC()) + setGC(SrcF->getGC()); + else + clearGC(); +} + +/// getIntrinsicID - This method returns the ID number of the specified +/// function, or Intrinsic::not_intrinsic if the function is not an +/// intrinsic, or if the pointer is null. This value is always defined to be +/// zero to allow easy checking for whether a function is intrinsic or not. The +/// particular intrinsic functions which correspond to this value are defined in +/// llvm/Intrinsics.h. +/// +unsigned Function::getIntrinsicID() const { + const ValueName *ValName = this->getValueName(); + if (!ValName || !isIntrinsic()) + return 0; + unsigned Len = ValName->getKeyLength(); + const char *Name = ValName->getKeyData(); + +#define GET_FUNCTION_RECOGNIZER +#include "llvm/IR/Intrinsics.gen" +#undef GET_FUNCTION_RECOGNIZER + return 0; +} + +std::string Intrinsic::getName(ID id, ArrayRef<Type*> Tys) { + assert(id < num_intrinsics && "Invalid intrinsic ID!"); + static const char * const Table[] = { + "not_intrinsic", +#define GET_INTRINSIC_NAME_TABLE +#include "llvm/IR/Intrinsics.gen" +#undef GET_INTRINSIC_NAME_TABLE + }; + if (Tys.empty()) + return Table[id]; + std::string Result(Table[id]); + for (unsigned i = 0; i < Tys.size(); ++i) { + if (PointerType* PTyp = dyn_cast<PointerType>(Tys[i])) { + Result += ".p" + llvm::utostr(PTyp->getAddressSpace()) + + EVT::getEVT(PTyp->getElementType()).getEVTString(); + } + else if (Tys[i]) + Result += "." + EVT::getEVT(Tys[i]).getEVTString(); + } + return Result; +} + + +/// IIT_Info - These are enumerators that describe the entries returned by the +/// getIntrinsicInfoTableEntries function. +/// +/// NOTE: This must be kept in synch with the copy in TblGen/IntrinsicEmitter! +enum IIT_Info { + // Common values should be encoded with 0-15. + IIT_Done = 0, + IIT_I1 = 1, + IIT_I8 = 2, + IIT_I16 = 3, + IIT_I32 = 4, + IIT_I64 = 5, + IIT_F16 = 6, + IIT_F32 = 7, + IIT_F64 = 8, + IIT_V2 = 9, + IIT_V4 = 10, + IIT_V8 = 11, + IIT_V16 = 12, + IIT_V32 = 13, + IIT_PTR = 14, + IIT_ARG = 15, + + // Values from 16+ are only encodable with the inefficient encoding. + IIT_MMX = 16, + IIT_METADATA = 17, + IIT_EMPTYSTRUCT = 18, + IIT_STRUCT2 = 19, + IIT_STRUCT3 = 20, + IIT_STRUCT4 = 21, + IIT_STRUCT5 = 22, + IIT_EXTEND_VEC_ARG = 23, + IIT_TRUNC_VEC_ARG = 24, + IIT_ANYPTR = 25 +}; + + +static void DecodeIITType(unsigned &NextElt, ArrayRef<unsigned char> Infos, + SmallVectorImpl<Intrinsic::IITDescriptor> &OutputTable) { + IIT_Info Info = IIT_Info(Infos[NextElt++]); + unsigned StructElts = 2; + using namespace Intrinsic; + + switch (Info) { + case IIT_Done: + OutputTable.push_back(IITDescriptor::get(IITDescriptor::Void, 0)); + return; + case IIT_MMX: + OutputTable.push_back(IITDescriptor::get(IITDescriptor::MMX, 0)); + return; + case IIT_METADATA: + OutputTable.push_back(IITDescriptor::get(IITDescriptor::Metadata, 0)); + return; + case IIT_F16: + OutputTable.push_back(IITDescriptor::get(IITDescriptor::Half, 0)); + return; + case IIT_F32: + OutputTable.push_back(IITDescriptor::get(IITDescriptor::Float, 0)); + return; + case IIT_F64: + OutputTable.push_back(IITDescriptor::get(IITDescriptor::Double, 0)); + return; + case IIT_I1: + OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 1)); + return; + case IIT_I8: + OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 8)); + return; + case IIT_I16: + OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer,16)); + return; + case IIT_I32: + OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 32)); + return; + case IIT_I64: + OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 64)); + return; + case IIT_V2: + OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 2)); + DecodeIITType(NextElt, Infos, OutputTable); + return; + case IIT_V4: + OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 4)); + DecodeIITType(NextElt, Infos, OutputTable); + return; + case IIT_V8: + OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 8)); + DecodeIITType(NextElt, Infos, OutputTable); + return; + case IIT_V16: + OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 16)); + DecodeIITType(NextElt, Infos, OutputTable); + return; + case IIT_V32: + OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 32)); + DecodeIITType(NextElt, Infos, OutputTable); + return; + case IIT_PTR: + OutputTable.push_back(IITDescriptor::get(IITDescriptor::Pointer, 0)); + DecodeIITType(NextElt, Infos, OutputTable); + return; + case IIT_ANYPTR: { // [ANYPTR addrspace, subtype] + OutputTable.push_back(IITDescriptor::get(IITDescriptor::Pointer, + Infos[NextElt++])); + DecodeIITType(NextElt, Infos, OutputTable); + return; + } + case IIT_ARG: { + unsigned ArgInfo = (NextElt == Infos.size() ? 0 : Infos[NextElt++]); + OutputTable.push_back(IITDescriptor::get(IITDescriptor::Argument, ArgInfo)); + return; + } + case IIT_EXTEND_VEC_ARG: { + unsigned ArgInfo = (NextElt == Infos.size() ? 0 : Infos[NextElt++]); + OutputTable.push_back(IITDescriptor::get(IITDescriptor::ExtendVecArgument, + ArgInfo)); + return; + } + case IIT_TRUNC_VEC_ARG: { + unsigned ArgInfo = (NextElt == Infos.size() ? 0 : Infos[NextElt++]); + OutputTable.push_back(IITDescriptor::get(IITDescriptor::TruncVecArgument, + ArgInfo)); + return; + } + case IIT_EMPTYSTRUCT: + OutputTable.push_back(IITDescriptor::get(IITDescriptor::Struct, 0)); + return; + case IIT_STRUCT5: ++StructElts; // FALL THROUGH. + case IIT_STRUCT4: ++StructElts; // FALL THROUGH. + case IIT_STRUCT3: ++StructElts; // FALL THROUGH. + case IIT_STRUCT2: { + OutputTable.push_back(IITDescriptor::get(IITDescriptor::Struct,StructElts)); + + for (unsigned i = 0; i != StructElts; ++i) + DecodeIITType(NextElt, Infos, OutputTable); + return; + } + } + llvm_unreachable("unhandled"); +} + + +#define GET_INTRINSIC_GENERATOR_GLOBAL +#include "llvm/IR/Intrinsics.gen" +#undef GET_INTRINSIC_GENERATOR_GLOBAL + +void Intrinsic::getIntrinsicInfoTableEntries(ID id, + SmallVectorImpl<IITDescriptor> &T){ + // Check to see if the intrinsic's type was expressible by the table. + unsigned TableVal = IIT_Table[id-1]; + + // Decode the TableVal into an array of IITValues. + SmallVector<unsigned char, 8> IITValues; + ArrayRef<unsigned char> IITEntries; + unsigned NextElt = 0; + if ((TableVal >> 31) != 0) { + // This is an offset into the IIT_LongEncodingTable. + IITEntries = IIT_LongEncodingTable; + + // Strip sentinel bit. + NextElt = (TableVal << 1) >> 1; + } else { + // Decode the TableVal into an array of IITValues. If the entry was encoded + // into a single word in the table itself, decode it now. + do { + IITValues.push_back(TableVal & 0xF); + TableVal >>= 4; + } while (TableVal); + + IITEntries = IITValues; + NextElt = 0; + } + + // Okay, decode the table into the output vector of IITDescriptors. + DecodeIITType(NextElt, IITEntries, T); + while (NextElt != IITEntries.size() && IITEntries[NextElt] != 0) + DecodeIITType(NextElt, IITEntries, T); +} + + +static Type *DecodeFixedType(ArrayRef<Intrinsic::IITDescriptor> &Infos, + ArrayRef<Type*> Tys, LLVMContext &Context) { + using namespace Intrinsic; + IITDescriptor D = Infos.front(); + Infos = Infos.slice(1); + + switch (D.Kind) { + case IITDescriptor::Void: return Type::getVoidTy(Context); + case IITDescriptor::MMX: return Type::getX86_MMXTy(Context); + case IITDescriptor::Metadata: return Type::getMetadataTy(Context); + case IITDescriptor::Half: return Type::getHalfTy(Context); + case IITDescriptor::Float: return Type::getFloatTy(Context); + case IITDescriptor::Double: return Type::getDoubleTy(Context); + + case IITDescriptor::Integer: + return IntegerType::get(Context, D.Integer_Width); + case IITDescriptor::Vector: + return VectorType::get(DecodeFixedType(Infos, Tys, Context),D.Vector_Width); + case IITDescriptor::Pointer: + return PointerType::get(DecodeFixedType(Infos, Tys, Context), + D.Pointer_AddressSpace); + case IITDescriptor::Struct: { + Type *Elts[5]; + assert(D.Struct_NumElements <= 5 && "Can't handle this yet"); + for (unsigned i = 0, e = D.Struct_NumElements; i != e; ++i) + Elts[i] = DecodeFixedType(Infos, Tys, Context); + return StructType::get(Context, ArrayRef<Type*>(Elts,D.Struct_NumElements)); + } + + case IITDescriptor::Argument: + return Tys[D.getArgumentNumber()]; + case IITDescriptor::ExtendVecArgument: + return VectorType::getExtendedElementVectorType(cast<VectorType>( + Tys[D.getArgumentNumber()])); + + case IITDescriptor::TruncVecArgument: + return VectorType::getTruncatedElementVectorType(cast<VectorType>( + Tys[D.getArgumentNumber()])); + } + llvm_unreachable("unhandled"); +} + + + +FunctionType *Intrinsic::getType(LLVMContext &Context, + ID id, ArrayRef<Type*> Tys) { + SmallVector<IITDescriptor, 8> Table; + getIntrinsicInfoTableEntries(id, Table); + + ArrayRef<IITDescriptor> TableRef = Table; + Type *ResultTy = DecodeFixedType(TableRef, Tys, Context); + + SmallVector<Type*, 8> ArgTys; + while (!TableRef.empty()) + ArgTys.push_back(DecodeFixedType(TableRef, Tys, Context)); + + return FunctionType::get(ResultTy, ArgTys, false); +} + +bool Intrinsic::isOverloaded(ID id) { +#define GET_INTRINSIC_OVERLOAD_TABLE +#include "llvm/IR/Intrinsics.gen" +#undef GET_INTRINSIC_OVERLOAD_TABLE +} + +/// This defines the "Intrinsic::getAttributes(ID id)" method. +#define GET_INTRINSIC_ATTRIBUTES +#include "llvm/IR/Intrinsics.gen" +#undef GET_INTRINSIC_ATTRIBUTES + +Function *Intrinsic::getDeclaration(Module *M, ID id, ArrayRef<Type*> Tys) { + // There can never be multiple globals with the same name of different types, + // because intrinsics must be a specific type. + return + cast<Function>(M->getOrInsertFunction(getName(id, Tys), + getType(M->getContext(), id, Tys))); +} + +// This defines the "Intrinsic::getIntrinsicForGCCBuiltin()" method. +#define GET_LLVM_INTRINSIC_FOR_GCC_BUILTIN +#include "llvm/IR/Intrinsics.gen" +#undef GET_LLVM_INTRINSIC_FOR_GCC_BUILTIN + +/// hasAddressTaken - returns true if there are any uses of this function +/// other than direct calls or invokes to it. +bool Function::hasAddressTaken(const User* *PutOffender) const { + for (Value::const_use_iterator I = use_begin(), E = use_end(); I != E; ++I) { + const User *U = *I; + if (isa<BlockAddress>(U)) + continue; + if (!isa<CallInst>(U) && !isa<InvokeInst>(U)) + return PutOffender ? (*PutOffender = U, true) : true; + ImmutableCallSite CS(cast<Instruction>(U)); + if (!CS.isCallee(I)) + return PutOffender ? (*PutOffender = U, true) : true; + } + return false; +} + +bool Function::isDefTriviallyDead() const { + // Check the linkage + if (!hasLinkOnceLinkage() && !hasLocalLinkage() && + !hasAvailableExternallyLinkage()) + return false; + + // Check if the function is used by anything other than a blockaddress. + for (Value::const_use_iterator I = use_begin(), E = use_end(); I != E; ++I) + if (!isa<BlockAddress>(*I)) + return false; + + return true; +} + +/// callsFunctionThatReturnsTwice - Return true if the function has a call to +/// setjmp or other function that gcc recognizes as "returning twice". +bool Function::callsFunctionThatReturnsTwice() const { + for (const_inst_iterator + I = inst_begin(this), E = inst_end(this); I != E; ++I) { + const CallInst* callInst = dyn_cast<CallInst>(&*I); + if (!callInst) + continue; + if (callInst->canReturnTwice()) + return true; + } + + return false; +} + |