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Diffstat (limited to 'lib/IR/Constants.cpp')
-rw-r--r-- | lib/IR/Constants.cpp | 2769 |
1 files changed, 2769 insertions, 0 deletions
diff --git a/lib/IR/Constants.cpp b/lib/IR/Constants.cpp new file mode 100644 index 0000000000..a97b620768 --- /dev/null +++ b/lib/IR/Constants.cpp @@ -0,0 +1,2769 @@ +//===-- Constants.cpp - Implement Constant nodes --------------------------===// +// +// 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 Constant* classes. +// +//===----------------------------------------------------------------------===// + +#include "llvm/Constants.h" +#include "ConstantFold.h" +#include "LLVMContextImpl.h" +#include "llvm/ADT/DenseMap.h" +#include "llvm/ADT/FoldingSet.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/ADT/SmallVector.h" +#include "llvm/ADT/StringExtras.h" +#include "llvm/ADT/StringMap.h" +#include "llvm/DerivedTypes.h" +#include "llvm/GlobalValue.h" +#include "llvm/Instructions.h" +#include "llvm/Module.h" +#include "llvm/Operator.h" +#include "llvm/Support/Compiler.h" +#include "llvm/Support/Debug.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/GetElementPtrTypeIterator.h" +#include "llvm/Support/ManagedStatic.h" +#include "llvm/Support/MathExtras.h" +#include "llvm/Support/raw_ostream.h" +#include <algorithm> +#include <cstdarg> +using namespace llvm; + +//===----------------------------------------------------------------------===// +// Constant Class +//===----------------------------------------------------------------------===// + +void Constant::anchor() { } + +bool Constant::isNegativeZeroValue() const { + // Floating point values have an explicit -0.0 value. + if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this)) + return CFP->isZero() && CFP->isNegative(); + + // Otherwise, just use +0.0. + return isNullValue(); +} + +bool Constant::isNullValue() const { + // 0 is null. + if (const ConstantInt *CI = dyn_cast<ConstantInt>(this)) + return CI->isZero(); + + // +0.0 is null. + if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this)) + return CFP->isZero() && !CFP->isNegative(); + + // constant zero is zero for aggregates and cpnull is null for pointers. + return isa<ConstantAggregateZero>(this) || isa<ConstantPointerNull>(this); +} + +bool Constant::isAllOnesValue() const { + // Check for -1 integers + if (const ConstantInt *CI = dyn_cast<ConstantInt>(this)) + return CI->isMinusOne(); + + // Check for FP which are bitcasted from -1 integers + if (const ConstantFP *CFP = dyn_cast<ConstantFP>(this)) + return CFP->getValueAPF().bitcastToAPInt().isAllOnesValue(); + + // Check for constant vectors which are splats of -1 values. + if (const ConstantVector *CV = dyn_cast<ConstantVector>(this)) + if (Constant *Splat = CV->getSplatValue()) + return Splat->isAllOnesValue(); + + // Check for constant vectors which are splats of -1 values. + if (const ConstantDataVector *CV = dyn_cast<ConstantDataVector>(this)) + if (Constant *Splat = CV->getSplatValue()) + return Splat->isAllOnesValue(); + + return false; +} + +// Constructor to create a '0' constant of arbitrary type... +Constant *Constant::getNullValue(Type *Ty) { + switch (Ty->getTypeID()) { + case Type::IntegerTyID: + return ConstantInt::get(Ty, 0); + case Type::HalfTyID: + return ConstantFP::get(Ty->getContext(), + APFloat::getZero(APFloat::IEEEhalf)); + case Type::FloatTyID: + return ConstantFP::get(Ty->getContext(), + APFloat::getZero(APFloat::IEEEsingle)); + case Type::DoubleTyID: + return ConstantFP::get(Ty->getContext(), + APFloat::getZero(APFloat::IEEEdouble)); + case Type::X86_FP80TyID: + return ConstantFP::get(Ty->getContext(), + APFloat::getZero(APFloat::x87DoubleExtended)); + case Type::FP128TyID: + return ConstantFP::get(Ty->getContext(), + APFloat::getZero(APFloat::IEEEquad)); + case Type::PPC_FP128TyID: + return ConstantFP::get(Ty->getContext(), + APFloat(APInt::getNullValue(128))); + case Type::PointerTyID: + return ConstantPointerNull::get(cast<PointerType>(Ty)); + case Type::StructTyID: + case Type::ArrayTyID: + case Type::VectorTyID: + return ConstantAggregateZero::get(Ty); + default: + // Function, Label, or Opaque type? + llvm_unreachable("Cannot create a null constant of that type!"); + } +} + +Constant *Constant::getIntegerValue(Type *Ty, const APInt &V) { + Type *ScalarTy = Ty->getScalarType(); + + // Create the base integer constant. + Constant *C = ConstantInt::get(Ty->getContext(), V); + + // Convert an integer to a pointer, if necessary. + if (PointerType *PTy = dyn_cast<PointerType>(ScalarTy)) + C = ConstantExpr::getIntToPtr(C, PTy); + + // Broadcast a scalar to a vector, if necessary. + if (VectorType *VTy = dyn_cast<VectorType>(Ty)) + C = ConstantVector::getSplat(VTy->getNumElements(), C); + + return C; +} + +Constant *Constant::getAllOnesValue(Type *Ty) { + if (IntegerType *ITy = dyn_cast<IntegerType>(Ty)) + return ConstantInt::get(Ty->getContext(), + APInt::getAllOnesValue(ITy->getBitWidth())); + + if (Ty->isFloatingPointTy()) { + APFloat FL = APFloat::getAllOnesValue(Ty->getPrimitiveSizeInBits(), + !Ty->isPPC_FP128Ty()); + return ConstantFP::get(Ty->getContext(), FL); + } + + VectorType *VTy = cast<VectorType>(Ty); + return ConstantVector::getSplat(VTy->getNumElements(), + getAllOnesValue(VTy->getElementType())); +} + +/// getAggregateElement - For aggregates (struct/array/vector) return the +/// constant that corresponds to the specified element if possible, or null if +/// not. This can return null if the element index is a ConstantExpr, or if +/// 'this' is a constant expr. +Constant *Constant::getAggregateElement(unsigned Elt) const { + if (const ConstantStruct *CS = dyn_cast<ConstantStruct>(this)) + return Elt < CS->getNumOperands() ? CS->getOperand(Elt) : 0; + + if (const ConstantArray *CA = dyn_cast<ConstantArray>(this)) + return Elt < CA->getNumOperands() ? CA->getOperand(Elt) : 0; + + if (const ConstantVector *CV = dyn_cast<ConstantVector>(this)) + return Elt < CV->getNumOperands() ? CV->getOperand(Elt) : 0; + + if (const ConstantAggregateZero *CAZ =dyn_cast<ConstantAggregateZero>(this)) + return CAZ->getElementValue(Elt); + + if (const UndefValue *UV = dyn_cast<UndefValue>(this)) + return UV->getElementValue(Elt); + + if (const ConstantDataSequential *CDS =dyn_cast<ConstantDataSequential>(this)) + return Elt < CDS->getNumElements() ? CDS->getElementAsConstant(Elt) : 0; + return 0; +} + +Constant *Constant::getAggregateElement(Constant *Elt) const { + assert(isa<IntegerType>(Elt->getType()) && "Index must be an integer"); + if (ConstantInt *CI = dyn_cast<ConstantInt>(Elt)) + return getAggregateElement(CI->getZExtValue()); + return 0; +} + + +void Constant::destroyConstantImpl() { + // When a Constant is destroyed, there may be lingering + // references to the constant by other constants in the constant pool. These + // constants are implicitly dependent on the module that is being deleted, + // but they don't know that. Because we only find out when the CPV is + // deleted, we must now notify all of our users (that should only be + // Constants) that they are, in fact, invalid now and should be deleted. + // + while (!use_empty()) { + Value *V = use_back(); +#ifndef NDEBUG // Only in -g mode... + if (!isa<Constant>(V)) { + dbgs() << "While deleting: " << *this + << "\n\nUse still stuck around after Def is destroyed: " + << *V << "\n\n"; + } +#endif + assert(isa<Constant>(V) && "References remain to Constant being destroyed"); + cast<Constant>(V)->destroyConstant(); + + // The constant should remove itself from our use list... + assert((use_empty() || use_back() != V) && "Constant not removed!"); + } + + // Value has no outstanding references it is safe to delete it now... + delete this; +} + +/// canTrap - Return true if evaluation of this constant could trap. This is +/// true for things like constant expressions that could divide by zero. +bool Constant::canTrap() const { + assert(getType()->isFirstClassType() && "Cannot evaluate aggregate vals!"); + // The only thing that could possibly trap are constant exprs. + const ConstantExpr *CE = dyn_cast<ConstantExpr>(this); + if (!CE) return false; + + // ConstantExpr traps if any operands can trap. + for (unsigned i = 0, e = getNumOperands(); i != e; ++i) + if (CE->getOperand(i)->canTrap()) + return true; + + // Otherwise, only specific operations can trap. + switch (CE->getOpcode()) { + default: + return false; + case Instruction::UDiv: + case Instruction::SDiv: + case Instruction::FDiv: + case Instruction::URem: + case Instruction::SRem: + case Instruction::FRem: + // Div and rem can trap if the RHS is not known to be non-zero. + if (!isa<ConstantInt>(CE->getOperand(1)) ||CE->getOperand(1)->isNullValue()) + return true; + return false; + } +} + +/// isThreadDependent - Return true if the value can vary between threads. +bool Constant::isThreadDependent() const { + SmallPtrSet<const Constant*, 64> Visited; + SmallVector<const Constant*, 64> WorkList; + WorkList.push_back(this); + Visited.insert(this); + + while (!WorkList.empty()) { + const Constant *C = WorkList.pop_back_val(); + + if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(C)) { + if (GV->isThreadLocal()) + return true; + } + + for (unsigned I = 0, E = C->getNumOperands(); I != E; ++I) { + const Constant *D = dyn_cast<Constant>(C->getOperand(I)); + if (!D) + continue; + if (Visited.insert(D)) + WorkList.push_back(D); + } + } + + return false; +} + +/// isConstantUsed - Return true if the constant has users other than constant +/// exprs and other dangling things. +bool Constant::isConstantUsed() const { + for (const_use_iterator UI = use_begin(), E = use_end(); UI != E; ++UI) { + const Constant *UC = dyn_cast<Constant>(*UI); + if (UC == 0 || isa<GlobalValue>(UC)) + return true; + + if (UC->isConstantUsed()) + return true; + } + return false; +} + + + +/// getRelocationInfo - This method classifies the entry according to +/// whether or not it may generate a relocation entry. This must be +/// conservative, so if it might codegen to a relocatable entry, it should say +/// so. The return values are: +/// +/// NoRelocation: This constant pool entry is guaranteed to never have a +/// relocation applied to it (because it holds a simple constant like +/// '4'). +/// LocalRelocation: This entry has relocations, but the entries are +/// guaranteed to be resolvable by the static linker, so the dynamic +/// linker will never see them. +/// GlobalRelocations: This entry may have arbitrary relocations. +/// +/// FIXME: This really should not be in IR. +Constant::PossibleRelocationsTy Constant::getRelocationInfo() const { + if (const GlobalValue *GV = dyn_cast<GlobalValue>(this)) { + if (GV->hasLocalLinkage() || GV->hasHiddenVisibility()) + return LocalRelocation; // Local to this file/library. + return GlobalRelocations; // Global reference. + } + + if (const BlockAddress *BA = dyn_cast<BlockAddress>(this)) + return BA->getFunction()->getRelocationInfo(); + + // While raw uses of blockaddress need to be relocated, differences between + // two of them don't when they are for labels in the same function. This is a + // common idiom when creating a table for the indirect goto extension, so we + // handle it efficiently here. + if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(this)) + if (CE->getOpcode() == Instruction::Sub) { + ConstantExpr *LHS = dyn_cast<ConstantExpr>(CE->getOperand(0)); + ConstantExpr *RHS = dyn_cast<ConstantExpr>(CE->getOperand(1)); + if (LHS && RHS && + LHS->getOpcode() == Instruction::PtrToInt && + RHS->getOpcode() == Instruction::PtrToInt && + isa<BlockAddress>(LHS->getOperand(0)) && + isa<BlockAddress>(RHS->getOperand(0)) && + cast<BlockAddress>(LHS->getOperand(0))->getFunction() == + cast<BlockAddress>(RHS->getOperand(0))->getFunction()) + return NoRelocation; + } + + PossibleRelocationsTy Result = NoRelocation; + for (unsigned i = 0, e = getNumOperands(); i != e; ++i) + Result = std::max(Result, + cast<Constant>(getOperand(i))->getRelocationInfo()); + + return Result; +} + +/// removeDeadUsersOfConstant - If the specified constantexpr is dead, remove +/// it. This involves recursively eliminating any dead users of the +/// constantexpr. +static bool removeDeadUsersOfConstant(const Constant *C) { + if (isa<GlobalValue>(C)) return false; // Cannot remove this + + while (!C->use_empty()) { + const Constant *User = dyn_cast<Constant>(C->use_back()); + if (!User) return false; // Non-constant usage; + if (!removeDeadUsersOfConstant(User)) + return false; // Constant wasn't dead + } + + const_cast<Constant*>(C)->destroyConstant(); + return true; +} + + +/// removeDeadConstantUsers - If there are any dead constant users dangling +/// off of this constant, remove them. This method is useful for clients +/// that want to check to see if a global is unused, but don't want to deal +/// with potentially dead constants hanging off of the globals. +void Constant::removeDeadConstantUsers() const { + Value::const_use_iterator I = use_begin(), E = use_end(); + Value::const_use_iterator LastNonDeadUser = E; + while (I != E) { + const Constant *User = dyn_cast<Constant>(*I); + if (User == 0) { + LastNonDeadUser = I; + ++I; + continue; + } + + if (!removeDeadUsersOfConstant(User)) { + // If the constant wasn't dead, remember that this was the last live use + // and move on to the next constant. + LastNonDeadUser = I; + ++I; + continue; + } + + // If the constant was dead, then the iterator is invalidated. + if (LastNonDeadUser == E) { + I = use_begin(); + if (I == E) break; + } else { + I = LastNonDeadUser; + ++I; + } + } +} + + + +//===----------------------------------------------------------------------===// +// ConstantInt +//===----------------------------------------------------------------------===// + +void ConstantInt::anchor() { } + +ConstantInt::ConstantInt(IntegerType *Ty, const APInt& V) + : Constant(Ty, ConstantIntVal, 0, 0), Val(V) { + assert(V.getBitWidth() == Ty->getBitWidth() && "Invalid constant for type"); +} + +ConstantInt *ConstantInt::getTrue(LLVMContext &Context) { + LLVMContextImpl *pImpl = Context.pImpl; + if (!pImpl->TheTrueVal) + pImpl->TheTrueVal = ConstantInt::get(Type::getInt1Ty(Context), 1); + return pImpl->TheTrueVal; +} + +ConstantInt *ConstantInt::getFalse(LLVMContext &Context) { + LLVMContextImpl *pImpl = Context.pImpl; + if (!pImpl->TheFalseVal) + pImpl->TheFalseVal = ConstantInt::get(Type::getInt1Ty(Context), 0); + return pImpl->TheFalseVal; +} + +Constant *ConstantInt::getTrue(Type *Ty) { + VectorType *VTy = dyn_cast<VectorType>(Ty); + if (!VTy) { + assert(Ty->isIntegerTy(1) && "True must be i1 or vector of i1."); + return ConstantInt::getTrue(Ty->getContext()); + } + assert(VTy->getElementType()->isIntegerTy(1) && + "True must be vector of i1 or i1."); + return ConstantVector::getSplat(VTy->getNumElements(), + ConstantInt::getTrue(Ty->getContext())); +} + +Constant *ConstantInt::getFalse(Type *Ty) { + VectorType *VTy = dyn_cast<VectorType>(Ty); + if (!VTy) { + assert(Ty->isIntegerTy(1) && "False must be i1 or vector of i1."); + return ConstantInt::getFalse(Ty->getContext()); + } + assert(VTy->getElementType()->isIntegerTy(1) && + "False must be vector of i1 or i1."); + return ConstantVector::getSplat(VTy->getNumElements(), + ConstantInt::getFalse(Ty->getContext())); +} + + +// Get a ConstantInt from an APInt. Note that the value stored in the DenseMap +// as the key, is a DenseMapAPIntKeyInfo::KeyTy which has provided the +// operator== and operator!= to ensure that the DenseMap doesn't attempt to +// compare APInt's of different widths, which would violate an APInt class +// invariant which generates an assertion. +ConstantInt *ConstantInt::get(LLVMContext &Context, const APInt &V) { + // Get the corresponding integer type for the bit width of the value. + IntegerType *ITy = IntegerType::get(Context, V.getBitWidth()); + // get an existing value or the insertion position + DenseMapAPIntKeyInfo::KeyTy Key(V, ITy); + ConstantInt *&Slot = Context.pImpl->IntConstants[Key]; + if (!Slot) Slot = new ConstantInt(ITy, V); + return Slot; +} + +Constant *ConstantInt::get(Type *Ty, uint64_t V, bool isSigned) { + Constant *C = get(cast<IntegerType>(Ty->getScalarType()), V, isSigned); + + // For vectors, broadcast the value. + if (VectorType *VTy = dyn_cast<VectorType>(Ty)) + return ConstantVector::getSplat(VTy->getNumElements(), C); + + return C; +} + +ConstantInt *ConstantInt::get(IntegerType *Ty, uint64_t V, + bool isSigned) { + return get(Ty->getContext(), APInt(Ty->getBitWidth(), V, isSigned)); +} + +ConstantInt *ConstantInt::getSigned(IntegerType *Ty, int64_t V) { + return get(Ty, V, true); +} + +Constant *ConstantInt::getSigned(Type *Ty, int64_t V) { + return get(Ty, V, true); +} + +Constant *ConstantInt::get(Type *Ty, const APInt& V) { + ConstantInt *C = get(Ty->getContext(), V); + assert(C->getType() == Ty->getScalarType() && + "ConstantInt type doesn't match the type implied by its value!"); + + // For vectors, broadcast the value. + if (VectorType *VTy = dyn_cast<VectorType>(Ty)) + return ConstantVector::getSplat(VTy->getNumElements(), C); + + return C; +} + +ConstantInt *ConstantInt::get(IntegerType* Ty, StringRef Str, + uint8_t radix) { + return get(Ty->getContext(), APInt(Ty->getBitWidth(), Str, radix)); +} + +//===----------------------------------------------------------------------===// +// ConstantFP +//===----------------------------------------------------------------------===// + +static const fltSemantics *TypeToFloatSemantics(Type *Ty) { + if (Ty->isHalfTy()) + return &APFloat::IEEEhalf; + if (Ty->isFloatTy()) + return &APFloat::IEEEsingle; + if (Ty->isDoubleTy()) + return &APFloat::IEEEdouble; + if (Ty->isX86_FP80Ty()) + return &APFloat::x87DoubleExtended; + else if (Ty->isFP128Ty()) + return &APFloat::IEEEquad; + + assert(Ty->isPPC_FP128Ty() && "Unknown FP format"); + return &APFloat::PPCDoubleDouble; +} + +void ConstantFP::anchor() { } + +/// get() - This returns a constant fp for the specified value in the +/// specified type. This should only be used for simple constant values like +/// 2.0/1.0 etc, that are known-valid both as double and as the target format. +Constant *ConstantFP::get(Type *Ty, double V) { + LLVMContext &Context = Ty->getContext(); + + APFloat FV(V); + bool ignored; + FV.convert(*TypeToFloatSemantics(Ty->getScalarType()), + APFloat::rmNearestTiesToEven, &ignored); + Constant *C = get(Context, FV); + + // For vectors, broadcast the value. + if (VectorType *VTy = dyn_cast<VectorType>(Ty)) + return ConstantVector::getSplat(VTy->getNumElements(), C); + + return C; +} + + +Constant *ConstantFP::get(Type *Ty, StringRef Str) { + LLVMContext &Context = Ty->getContext(); + + APFloat FV(*TypeToFloatSemantics(Ty->getScalarType()), Str); + Constant *C = get(Context, FV); + + // For vectors, broadcast the value. + if (VectorType *VTy = dyn_cast<VectorType>(Ty)) + return ConstantVector::getSplat(VTy->getNumElements(), C); + + return C; +} + + +ConstantFP *ConstantFP::getNegativeZero(Type *Ty) { + LLVMContext &Context = Ty->getContext(); + APFloat apf = cast<ConstantFP>(Constant::getNullValue(Ty))->getValueAPF(); + apf.changeSign(); + return get(Context, apf); +} + + +Constant *ConstantFP::getZeroValueForNegation(Type *Ty) { + Type *ScalarTy = Ty->getScalarType(); + if (ScalarTy->isFloatingPointTy()) { + Constant *C = getNegativeZero(ScalarTy); + if (VectorType *VTy = dyn_cast<VectorType>(Ty)) + return ConstantVector::getSplat(VTy->getNumElements(), C); + return C; + } + + return Constant::getNullValue(Ty); +} + + +// ConstantFP accessors. +ConstantFP* ConstantFP::get(LLVMContext &Context, const APFloat& V) { + DenseMapAPFloatKeyInfo::KeyTy Key(V); + + LLVMContextImpl* pImpl = Context.pImpl; + + ConstantFP *&Slot = pImpl->FPConstants[Key]; + + if (!Slot) { + Type *Ty; + if (&V.getSemantics() == &APFloat::IEEEhalf) + Ty = Type::getHalfTy(Context); + else if (&V.getSemantics() == &APFloat::IEEEsingle) + Ty = Type::getFloatTy(Context); + else if (&V.getSemantics() == &APFloat::IEEEdouble) + Ty = Type::getDoubleTy(Context); + else if (&V.getSemantics() == &APFloat::x87DoubleExtended) + Ty = Type::getX86_FP80Ty(Context); + else if (&V.getSemantics() == &APFloat::IEEEquad) + Ty = Type::getFP128Ty(Context); + else { + assert(&V.getSemantics() == &APFloat::PPCDoubleDouble && + "Unknown FP format"); + Ty = Type::getPPC_FP128Ty(Context); + } + Slot = new ConstantFP(Ty, V); + } + + return Slot; +} + +ConstantFP *ConstantFP::getInfinity(Type *Ty, bool Negative) { + const fltSemantics &Semantics = *TypeToFloatSemantics(Ty); + return ConstantFP::get(Ty->getContext(), + APFloat::getInf(Semantics, Negative)); +} + +ConstantFP::ConstantFP(Type *Ty, const APFloat& V) + : Constant(Ty, ConstantFPVal, 0, 0), Val(V) { + assert(&V.getSemantics() == TypeToFloatSemantics(Ty) && + "FP type Mismatch"); +} + +bool ConstantFP::isExactlyValue(const APFloat &V) const { + return Val.bitwiseIsEqual(V); +} + +//===----------------------------------------------------------------------===// +// ConstantAggregateZero Implementation +//===----------------------------------------------------------------------===// + +/// getSequentialElement - If this CAZ has array or vector type, return a zero +/// with the right element type. +Constant *ConstantAggregateZero::getSequentialElement() const { + return Constant::getNullValue(getType()->getSequentialElementType()); +} + +/// getStructElement - If this CAZ has struct type, return a zero with the +/// right element type for the specified element. +Constant *ConstantAggregateZero::getStructElement(unsigned Elt) const { + return Constant::getNullValue(getType()->getStructElementType(Elt)); +} + +/// getElementValue - Return a zero of the right value for the specified GEP +/// index if we can, otherwise return null (e.g. if C is a ConstantExpr). +Constant *ConstantAggregateZero::getElementValue(Constant *C) const { + if (isa<SequentialType>(getType())) + return getSequentialElement(); + return getStructElement(cast<ConstantInt>(C)->getZExtValue()); +} + +/// getElementValue - Return a zero of the right value for the specified GEP +/// index. +Constant *ConstantAggregateZero::getElementValue(unsigned Idx) const { + if (isa<SequentialType>(getType())) + return getSequentialElement(); + return getStructElement(Idx); +} + + +//===----------------------------------------------------------------------===// +// UndefValue Implementation +//===----------------------------------------------------------------------===// + +/// getSequentialElement - If this undef has array or vector type, return an +/// undef with the right element type. +UndefValue *UndefValue::getSequentialElement() const { + return UndefValue::get(getType()->getSequentialElementType()); +} + +/// getStructElement - If this undef has struct type, return a zero with the +/// right element type for the specified element. +UndefValue *UndefValue::getStructElement(unsigned Elt) const { + return UndefValue::get(getType()->getStructElementType(Elt)); +} + +/// getElementValue - Return an undef of the right value for the specified GEP +/// index if we can, otherwise return null (e.g. if C is a ConstantExpr). +UndefValue *UndefValue::getElementValue(Constant *C) const { + if (isa<SequentialType>(getType())) + return getSequentialElement(); + return getStructElement(cast<ConstantInt>(C)->getZExtValue()); +} + +/// getElementValue - Return an undef of the right value for the specified GEP +/// index. +UndefValue *UndefValue::getElementValue(unsigned Idx) const { + if (isa<SequentialType>(getType())) + return getSequentialElement(); + return getStructElement(Idx); +} + + + +//===----------------------------------------------------------------------===// +// ConstantXXX Classes +//===----------------------------------------------------------------------===// + +template <typename ItTy, typename EltTy> +static bool rangeOnlyContains(ItTy Start, ItTy End, EltTy Elt) { + for (; Start != End; ++Start) + if (*Start != Elt) + return false; + return true; +} + +ConstantArray::ConstantArray(ArrayType *T, ArrayRef<Constant *> V) + : Constant(T, ConstantArrayVal, + OperandTraits<ConstantArray>::op_end(this) - V.size(), + V.size()) { + assert(V.size() == T->getNumElements() && + "Invalid initializer vector for constant array"); + for (unsigned i = 0, e = V.size(); i != e; ++i) + assert(V[i]->getType() == T->getElementType() && + "Initializer for array element doesn't match array element type!"); + std::copy(V.begin(), V.end(), op_begin()); +} + +Constant *ConstantArray::get(ArrayType *Ty, ArrayRef<Constant*> V) { + // Empty arrays are canonicalized to ConstantAggregateZero. + if (V.empty()) + return ConstantAggregateZero::get(Ty); + + for (unsigned i = 0, e = V.size(); i != e; ++i) { + assert(V[i]->getType() == Ty->getElementType() && + "Wrong type in array element initializer"); + } + LLVMContextImpl *pImpl = Ty->getContext().pImpl; + + // If this is an all-zero array, return a ConstantAggregateZero object. If + // all undef, return an UndefValue, if "all simple", then return a + // ConstantDataArray. + Constant *C = V[0]; + if (isa<UndefValue>(C) && rangeOnlyContains(V.begin(), V.end(), C)) + return UndefValue::get(Ty); + + if (C->isNullValue() && rangeOnlyContains(V.begin(), V.end(), C)) + return ConstantAggregateZero::get(Ty); + + // Check to see if all of the elements are ConstantFP or ConstantInt and if + // the element type is compatible with ConstantDataVector. If so, use it. + if (ConstantDataSequential::isElementTypeCompatible(C->getType())) { + // We speculatively build the elements here even if it turns out that there + // is a constantexpr or something else weird in the array, since it is so + // uncommon for that to happen. + if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) { + if (CI->getType()->isIntegerTy(8)) { + SmallVector<uint8_t, 16> Elts; + for (unsigned i = 0, e = V.size(); i != e; ++i) + if (ConstantInt *CI = dyn_cast<ConstantInt>(V[i])) + Elts.push_back(CI->getZExtValue()); + else + break; + if (Elts.size() == V.size()) + return ConstantDataArray::get(C->getContext(), Elts); + } else if (CI->getType()->isIntegerTy(16)) { + SmallVector<uint16_t, 16> Elts; + for (unsigned i = 0, e = V.size(); i != e; ++i) + if (ConstantInt *CI = dyn_cast<ConstantInt>(V[i])) + Elts.push_back(CI->getZExtValue()); + else + break; + if (Elts.size() == V.size()) + return ConstantDataArray::get(C->getContext(), Elts); + } else if (CI->getType()->isIntegerTy(32)) { + SmallVector<uint32_t, 16> Elts; + for (unsigned i = 0, e = V.size(); i != e; ++i) + if (ConstantInt *CI = dyn_cast<ConstantInt>(V[i])) + Elts.push_back(CI->getZExtValue()); + else + break; + if (Elts.size() == V.size()) + return ConstantDataArray::get(C->getContext(), Elts); + } else if (CI->getType()->isIntegerTy(64)) { + SmallVector<uint64_t, 16> Elts; + for (unsigned i = 0, e = V.size(); i != e; ++i) + if (ConstantInt *CI = dyn_cast<ConstantInt>(V[i])) + Elts.push_back(CI->getZExtValue()); + else + break; + if (Elts.size() == V.size()) + return ConstantDataArray::get(C->getContext(), Elts); + } + } + + if (ConstantFP *CFP = dyn_cast<ConstantFP>(C)) { + if (CFP->getType()->isFloatTy()) { + SmallVector<float, 16> Elts; + for (unsigned i = 0, e = V.size(); i != e; ++i) + if (ConstantFP *CFP = dyn_cast<ConstantFP>(V[i])) + Elts.push_back(CFP->getValueAPF().convertToFloat()); + else + break; + if (Elts.size() == V.size()) + return ConstantDataArray::get(C->getContext(), Elts); + } else if (CFP->getType()->isDoubleTy()) { + SmallVector<double, 16> Elts; + for (unsigned i = 0, e = V.size(); i != e; ++i) + if (ConstantFP *CFP = dyn_cast<ConstantFP>(V[i])) + Elts.push_back(CFP->getValueAPF().convertToDouble()); + else + break; + if (Elts.size() == V.size()) + return ConstantDataArray::get(C->getContext(), Elts); + } + } + } + + // Otherwise, we really do want to create a ConstantArray. + return pImpl->ArrayConstants.getOrCreate(Ty, V); +} + +/// getTypeForElements - Return an anonymous struct type to use for a constant +/// with the specified set of elements. The list must not be empty. +StructType *ConstantStruct::getTypeForElements(LLVMContext &Context, + ArrayRef<Constant*> V, + bool Packed) { + unsigned VecSize = V.size(); + SmallVector<Type*, 16> EltTypes(VecSize); + for (unsigned i = 0; i != VecSize; ++i) + EltTypes[i] = V[i]->getType(); + + return StructType::get(Context, EltTypes, Packed); +} + + +StructType *ConstantStruct::getTypeForElements(ArrayRef<Constant*> V, + bool Packed) { + assert(!V.empty() && + "ConstantStruct::getTypeForElements cannot be called on empty list"); + return getTypeForElements(V[0]->getContext(), V, Packed); +} + + +ConstantStruct::ConstantStruct(StructType *T, ArrayRef<Constant *> V) + : Constant(T, ConstantStructVal, + OperandTraits<ConstantStruct>::op_end(this) - V.size(), + V.size()) { + assert(V.size() == T->getNumElements() && + "Invalid initializer vector for constant structure"); + for (unsigned i = 0, e = V.size(); i != e; ++i) + assert((T->isOpaque() || V[i]->getType() == T->getElementType(i)) && + "Initializer for struct element doesn't match struct element type!"); + std::copy(V.begin(), V.end(), op_begin()); +} + +// ConstantStruct accessors. +Constant *ConstantStruct::get(StructType *ST, ArrayRef<Constant*> V) { + assert((ST->isOpaque() || ST->getNumElements() == V.size()) && + "Incorrect # elements specified to ConstantStruct::get"); + + // Create a ConstantAggregateZero value if all elements are zeros. + bool isZero = true; + bool isUndef = false; + + if (!V.empty()) { + isUndef = isa<UndefValue>(V[0]); + isZero = V[0]->isNullValue(); + if (isUndef || isZero) { + for (unsigned i = 0, e = V.size(); i != e; ++i) { + if (!V[i]->isNullValue()) + isZero = false; + if (!isa<UndefValue>(V[i])) + isUndef = false; + } + } + } + if (isZero) + return ConstantAggregateZero::get(ST); + if (isUndef) + return UndefValue::get(ST); + + return ST->getContext().pImpl->StructConstants.getOrCreate(ST, V); +} + +Constant *ConstantStruct::get(StructType *T, ...) { + va_list ap; + SmallVector<Constant*, 8> Values; + va_start(ap, T); + while (Constant *Val = va_arg(ap, llvm::Constant*)) + Values.push_back(Val); + va_end(ap); + return get(T, Values); +} + +ConstantVector::ConstantVector(VectorType *T, ArrayRef<Constant *> V) + : Constant(T, ConstantVectorVal, + OperandTraits<ConstantVector>::op_end(this) - V.size(), + V.size()) { + for (size_t i = 0, e = V.size(); i != e; i++) + assert(V[i]->getType() == T->getElementType() && + "Initializer for vector element doesn't match vector element type!"); + std::copy(V.begin(), V.end(), op_begin()); +} + +// ConstantVector accessors. +Constant *ConstantVector::get(ArrayRef<Constant*> V) { + assert(!V.empty() && "Vectors can't be empty"); + VectorType *T = VectorType::get(V.front()->getType(), V.size()); + LLVMContextImpl *pImpl = T->getContext().pImpl; + + // If this is an all-undef or all-zero vector, return a + // ConstantAggregateZero or UndefValue. + Constant *C = V[0]; + bool isZero = C->isNullValue(); + bool isUndef = isa<UndefValue>(C); + + if (isZero || isUndef) { + for (unsigned i = 1, e = V.size(); i != e; ++i) + if (V[i] != C) { + isZero = isUndef = false; + break; + } + } + + if (isZero) + return ConstantAggregateZero::get(T); + if (isUndef) + return UndefValue::get(T); + + // Check to see if all of the elements are ConstantFP or ConstantInt and if + // the element type is compatible with ConstantDataVector. If so, use it. + if (ConstantDataSequential::isElementTypeCompatible(C->getType())) { + // We speculatively build the elements here even if it turns out that there + // is a constantexpr or something else weird in the array, since it is so + // uncommon for that to happen. + if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) { + if (CI->getType()->isIntegerTy(8)) { + SmallVector<uint8_t, 16> Elts; + for (unsigned i = 0, e = V.size(); i != e; ++i) + if (ConstantInt *CI = dyn_cast<ConstantInt>(V[i])) + Elts.push_back(CI->getZExtValue()); + else + break; + if (Elts.size() == V.size()) + return ConstantDataVector::get(C->getContext(), Elts); + } else if (CI->getType()->isIntegerTy(16)) { + SmallVector<uint16_t, 16> Elts; + for (unsigned i = 0, e = V.size(); i != e; ++i) + if (ConstantInt *CI = dyn_cast<ConstantInt>(V[i])) + Elts.push_back(CI->getZExtValue()); + else + break; + if (Elts.size() == V.size()) + return ConstantDataVector::get(C->getContext(), Elts); + } else if (CI->getType()->isIntegerTy(32)) { + SmallVector<uint32_t, 16> Elts; + for (unsigned i = 0, e = V.size(); i != e; ++i) + if (ConstantInt *CI = dyn_cast<ConstantInt>(V[i])) + Elts.push_back(CI->getZExtValue()); + else + break; + if (Elts.size() == V.size()) + return ConstantDataVector::get(C->getContext(), Elts); + } else if (CI->getType()->isIntegerTy(64)) { + SmallVector<uint64_t, 16> Elts; + for (unsigned i = 0, e = V.size(); i != e; ++i) + if (ConstantInt *CI = dyn_cast<ConstantInt>(V[i])) + Elts.push_back(CI->getZExtValue()); + else + break; + if (Elts.size() == V.size()) + return ConstantDataVector::get(C->getContext(), Elts);< |