llvm/lib/VMCore/Constants.cpp
2004-02-15 04:07:32 +00:00

1118 lines
37 KiB
C++

//===-- Constants.cpp - Implement Constant nodes --------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and 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 "ConstantFolding.h"
#include "llvm/DerivedTypes.h"
#include "llvm/iMemory.h"
#include "llvm/SymbolTable.h"
#include "llvm/Module.h"
#include "Support/StringExtras.h"
#include <algorithm>
using namespace llvm;
ConstantBool *ConstantBool::True = new ConstantBool(true);
ConstantBool *ConstantBool::False = new ConstantBool(false);
//===----------------------------------------------------------------------===//
// Constant Class
//===----------------------------------------------------------------------===//
// Specialize setName to take care of symbol table majik
void Constant::setName(const std::string &Name, SymbolTable *ST) {
assert(ST && "Type::setName - Must provide symbol table argument!");
if (Name.size()) ST->insert(Name, this);
}
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))
std::cerr << "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");
Constant *CPV = cast<Constant>(V);
CPV->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;
}
static std::map<const Type *, Constant*> NullValues;
// Static constructor to create a '0' constant of arbitrary type...
Constant *Constant::getNullValue(const Type *Ty) {
switch (Ty->getPrimitiveID()) {
case Type::BoolTyID: {
static Constant *NullBool = ConstantBool::get(false);
return NullBool;
}
case Type::SByteTyID: {
static Constant *NullSByte = ConstantSInt::get(Type::SByteTy, 0);
return NullSByte;
}
case Type::UByteTyID: {
static Constant *NullUByte = ConstantUInt::get(Type::UByteTy, 0);
return NullUByte;
}
case Type::ShortTyID: {
static Constant *NullShort = ConstantSInt::get(Type::ShortTy, 0);
return NullShort;
}
case Type::UShortTyID: {
static Constant *NullUShort = ConstantUInt::get(Type::UShortTy, 0);
return NullUShort;
}
case Type::IntTyID: {
static Constant *NullInt = ConstantSInt::get(Type::IntTy, 0);
return NullInt;
}
case Type::UIntTyID: {
static Constant *NullUInt = ConstantUInt::get(Type::UIntTy, 0);
return NullUInt;
}
case Type::LongTyID: {
static Constant *NullLong = ConstantSInt::get(Type::LongTy, 0);
return NullLong;
}
case Type::ULongTyID: {
static Constant *NullULong = ConstantUInt::get(Type::ULongTy, 0);
return NullULong;
}
case Type::FloatTyID: {
static Constant *NullFloat = ConstantFP::get(Type::FloatTy, 0);
return NullFloat;
}
case Type::DoubleTyID: {
static Constant *NullDouble = ConstantFP::get(Type::DoubleTy, 0);
return NullDouble;
}
case Type::PointerTyID:
return ConstantPointerNull::get(cast<PointerType>(Ty));
case Type::StructTyID: {
if (!Ty->isAbstract())
if (Constant *V = NullValues[Ty])
return V;
const StructType *ST = cast<StructType>(Ty);
std::vector<Constant*> Elements;
Elements.resize(ST->getNumElements());
for (unsigned i = 0, e = ST->getNumElements(); i != e; ++i)
Elements[i] = Constant::getNullValue(ST->getElementType(i));
Constant *Ret = ConstantStruct::get(ST, Elements);
if (!Ty->isAbstract())
NullValues[Ty] = Ret;
return Ret;
}
case Type::ArrayTyID: {
if (!Ty->isAbstract())
if (Constant *V = NullValues[Ty])
return V;
const ArrayType *AT = cast<ArrayType>(Ty);
Constant *El = Constant::getNullValue(AT->getElementType());
unsigned NumElements = AT->getNumElements();
Constant *Ret = ConstantArray::get(AT,
std::vector<Constant*>(NumElements, El));
if (!Ty->isAbstract())
NullValues[Ty] = Ret;
return Ret;
}
default:
// Function, Type, Label, or Opaque type?
assert(0 && "Cannot create a null constant of that type!");
return 0;
}
}
// Static constructor to create the maximum constant of an integral type...
ConstantIntegral *ConstantIntegral::getMaxValue(const Type *Ty) {
switch (Ty->getPrimitiveID()) {
case Type::BoolTyID: return ConstantBool::True;
case Type::SByteTyID:
case Type::ShortTyID:
case Type::IntTyID:
case Type::LongTyID: {
// Calculate 011111111111111...
unsigned TypeBits = Ty->getPrimitiveSize()*8;
int64_t Val = INT64_MAX; // All ones
Val >>= 64-TypeBits; // Shift out unwanted 1 bits...
return ConstantSInt::get(Ty, Val);
}
case Type::UByteTyID:
case Type::UShortTyID:
case Type::UIntTyID:
case Type::ULongTyID: return getAllOnesValue(Ty);
default: return 0;
}
}
// Static constructor to create the minimum constant for an integral type...
ConstantIntegral *ConstantIntegral::getMinValue(const Type *Ty) {
switch (Ty->getPrimitiveID()) {
case Type::BoolTyID: return ConstantBool::False;
case Type::SByteTyID:
case Type::ShortTyID:
case Type::IntTyID:
case Type::LongTyID: {
// Calculate 1111111111000000000000
unsigned TypeBits = Ty->getPrimitiveSize()*8;
int64_t Val = -1; // All ones
Val <<= TypeBits-1; // Shift over to the right spot
return ConstantSInt::get(Ty, Val);
}
case Type::UByteTyID:
case Type::UShortTyID:
case Type::UIntTyID:
case Type::ULongTyID: return ConstantUInt::get(Ty, 0);
default: return 0;
}
}
// Static constructor to create an integral constant with all bits set
ConstantIntegral *ConstantIntegral::getAllOnesValue(const Type *Ty) {
switch (Ty->getPrimitiveID()) {
case Type::BoolTyID: return ConstantBool::True;
case Type::SByteTyID:
case Type::ShortTyID:
case Type::IntTyID:
case Type::LongTyID: return ConstantSInt::get(Ty, -1);
case Type::UByteTyID:
case Type::UShortTyID:
case Type::UIntTyID:
case Type::ULongTyID: {
// Calculate ~0 of the right type...
unsigned TypeBits = Ty->getPrimitiveSize()*8;
uint64_t Val = ~0ULL; // All ones
Val >>= 64-TypeBits; // Shift out unwanted 1 bits...
return ConstantUInt::get(Ty, Val);
}
default: return 0;
}
}
bool ConstantUInt::isAllOnesValue() const {
unsigned TypeBits = getType()->getPrimitiveSize()*8;
uint64_t Val = ~0ULL; // All ones
Val >>= 64-TypeBits; // Shift out inappropriate bits
return getValue() == Val;
}
//===----------------------------------------------------------------------===//
// ConstantXXX Classes
//===----------------------------------------------------------------------===//
//===----------------------------------------------------------------------===//
// Normal Constructors
ConstantBool::ConstantBool(bool V) : ConstantIntegral(Type::BoolTy) {
Val = V;
}
ConstantInt::ConstantInt(const Type *Ty, uint64_t V) : ConstantIntegral(Ty) {
Val.Unsigned = V;
}
ConstantSInt::ConstantSInt(const Type *Ty, int64_t V) : ConstantInt(Ty, V) {
assert(Ty->isInteger() && Ty->isSigned() &&
"Illegal type for unsigned integer constant!");
assert(isValueValidForType(Ty, V) && "Value too large for type!");
}
ConstantUInt::ConstantUInt(const Type *Ty, uint64_t V) : ConstantInt(Ty, V) {
assert(Ty->isInteger() && Ty->isUnsigned() &&
"Illegal type for unsigned integer constant!");
assert(isValueValidForType(Ty, V) && "Value too large for type!");
}
ConstantFP::ConstantFP(const Type *Ty, double V) : Constant(Ty) {
assert(isValueValidForType(Ty, V) && "Value too large for type!");
Val = V;
}
ConstantArray::ConstantArray(const ArrayType *T,
const std::vector<Constant*> &V) : Constant(T) {
Operands.reserve(V.size());
for (unsigned i = 0, e = V.size(); i != e; ++i) {
assert(V[i]->getType() == T->getElementType() ||
(T->isAbstract() &&
V[i]->getType()->getPrimitiveID() ==
T->getElementType()->getPrimitiveID()));
Operands.push_back(Use(V[i], this));
}
}
ConstantStruct::ConstantStruct(const StructType *T,
const std::vector<Constant*> &V) : Constant(T) {
assert(V.size() == T->getNumElements() &&
"Invalid initializer vector for constant structure");
Operands.reserve(V.size());
for (unsigned i = 0, e = V.size(); i != e; ++i) {
assert((V[i]->getType() == T->getElementType(i) ||
((T->getElementType(i)->isAbstract() ||
V[i]->getType()->isAbstract()) &&
T->getElementType(i)->getPrimitiveID() ==
V[i]->getType()->getPrimitiveID())) &&
"Initializer for struct element doesn't match struct element type!");
Operands.push_back(Use(V[i], this));
}
}
ConstantPointerRef::ConstantPointerRef(GlobalValue *GV)
: Constant(GV->getType()) {
Operands.push_back(Use(GV, this));
}
ConstantExpr::ConstantExpr(unsigned Opcode, Constant *C, const Type *Ty)
: Constant(Ty), iType(Opcode) {
Operands.push_back(Use(C, this));
}
static bool isSetCC(unsigned Opcode) {
return Opcode == Instruction::SetEQ || Opcode == Instruction::SetNE ||
Opcode == Instruction::SetLT || Opcode == Instruction::SetGT ||
Opcode == Instruction::SetLE || Opcode == Instruction::SetGE;
}
ConstantExpr::ConstantExpr(unsigned Opcode, Constant *C1, Constant *C2)
: Constant(isSetCC(Opcode) ? Type::BoolTy : C1->getType()), iType(Opcode) {
Operands.push_back(Use(C1, this));
Operands.push_back(Use(C2, this));
}
ConstantExpr::ConstantExpr(Constant *C, const std::vector<Constant*> &IdxList,
const Type *DestTy)
: Constant(DestTy), iType(Instruction::GetElementPtr) {
Operands.reserve(1+IdxList.size());
Operands.push_back(Use(C, this));
for (unsigned i = 0, E = IdxList.size(); i != E; ++i)
Operands.push_back(Use(IdxList[i], this));
}
//===----------------------------------------------------------------------===//
// classof implementations
bool ConstantIntegral::classof(const Constant *CPV) {
return CPV->getType()->isIntegral() && !isa<ConstantExpr>(CPV);
}
bool ConstantInt::classof(const Constant *CPV) {
return CPV->getType()->isInteger() && !isa<ConstantExpr>(CPV);
}
bool ConstantSInt::classof(const Constant *CPV) {
return CPV->getType()->isSigned() && !isa<ConstantExpr>(CPV);
}
bool ConstantUInt::classof(const Constant *CPV) {
return CPV->getType()->isUnsigned() && !isa<ConstantExpr>(CPV);
}
bool ConstantFP::classof(const Constant *CPV) {
const Type *Ty = CPV->getType();
return ((Ty == Type::FloatTy || Ty == Type::DoubleTy) &&
!isa<ConstantExpr>(CPV));
}
bool ConstantArray::classof(const Constant *CPV) {
return isa<ArrayType>(CPV->getType()) && !isa<ConstantExpr>(CPV);
}
bool ConstantStruct::classof(const Constant *CPV) {
return isa<StructType>(CPV->getType()) && !isa<ConstantExpr>(CPV);
}
bool ConstantPointerNull::classof(const Constant *CPV) {
return isa<PointerType>(CPV->getType()) && !isa<ConstantExpr>(CPV) &&
CPV->getNumOperands() == 0;
}
bool ConstantPointerRef::classof(const Constant *CPV) {
return isa<PointerType>(CPV->getType()) && !isa<ConstantExpr>(CPV) &&
CPV->getNumOperands() == 1;
}
//===----------------------------------------------------------------------===//
// isValueValidForType implementations
bool ConstantSInt::isValueValidForType(const Type *Ty, int64_t Val) {
switch (Ty->getPrimitiveID()) {
default:
return false; // These can't be represented as integers!!!
// Signed types...
case Type::SByteTyID:
return (Val <= INT8_MAX && Val >= INT8_MIN);
case Type::ShortTyID:
return (Val <= INT16_MAX && Val >= INT16_MIN);
case Type::IntTyID:
return (Val <= INT32_MAX && Val >= INT32_MIN);
case Type::LongTyID:
return true; // This is the largest type...
}
assert(0 && "WTF?");
return false;
}
bool ConstantUInt::isValueValidForType(const Type *Ty, uint64_t Val) {
switch (Ty->getPrimitiveID()) {
default:
return false; // These can't be represented as integers!!!
// Unsigned types...
case Type::UByteTyID:
return (Val <= UINT8_MAX);
case Type::UShortTyID:
return (Val <= UINT16_MAX);
case Type::UIntTyID:
return (Val <= UINT32_MAX);
case Type::ULongTyID:
return true; // This is the largest type...
}
assert(0 && "WTF?");
return false;
}
bool ConstantFP::isValueValidForType(const Type *Ty, double Val) {
switch (Ty->getPrimitiveID()) {
default:
return false; // These can't be represented as floating point!
// TODO: Figure out how to test if a double can be cast to a float!
case Type::FloatTyID:
case Type::DoubleTyID:
return true; // This is the largest type...
}
};
//===----------------------------------------------------------------------===//
// replaceUsesOfWithOnConstant implementations
void ConstantArray::replaceUsesOfWithOnConstant(Value *From, Value *To,
bool DisableChecking) {
assert(isa<Constant>(To) && "Cannot make Constant refer to non-constant!");
std::vector<Constant*> Values;
Values.reserve(getValues().size()); // Build replacement array...
for (unsigned i = 0, e = getValues().size(); i != e; ++i) {
Constant *Val = cast<Constant>(getValues()[i]);
if (Val == From) Val = cast<Constant>(To);
Values.push_back(Val);
}
Constant *Replacement = ConstantArray::get(getType(), Values);
assert(Replacement != this && "I didn't contain From!");
// Everyone using this now uses the replacement...
if (DisableChecking)
uncheckedReplaceAllUsesWith(Replacement);
else
replaceAllUsesWith(Replacement);
// Delete the old constant!
destroyConstant();
}
void ConstantStruct::replaceUsesOfWithOnConstant(Value *From, Value *To,
bool DisableChecking) {
assert(isa<Constant>(To) && "Cannot make Constant refer to non-constant!");
std::vector<Constant*> Values;
Values.reserve(getValues().size());
for (unsigned i = 0, e = getValues().size(); i != e; ++i) {
Constant *Val = cast<Constant>(getValues()[i]);
if (Val == From) Val = cast<Constant>(To);
Values.push_back(Val);
}
Constant *Replacement = ConstantStruct::get(getType(), Values);
assert(Replacement != this && "I didn't contain From!");
// Everyone using this now uses the replacement...
if (DisableChecking)
uncheckedReplaceAllUsesWith(Replacement);
else
replaceAllUsesWith(Replacement);
// Delete the old constant!
destroyConstant();
}
void ConstantPointerRef::replaceUsesOfWithOnConstant(Value *From, Value *To,
bool DisableChecking) {
if (isa<GlobalValue>(To)) {
assert(From == getOperand(0) && "Doesn't contain from!");
ConstantPointerRef *Replacement =
ConstantPointerRef::get(cast<GlobalValue>(To));
// Everyone using this now uses the replacement...
if (DisableChecking)
uncheckedReplaceAllUsesWith(Replacement);
else
replaceAllUsesWith(Replacement);
} else {
// Just replace ourselves with the To value specified.
if (DisableChecking)
uncheckedReplaceAllUsesWith(To);
else
replaceAllUsesWith(To);
}
// Delete the old constant!
destroyConstant();
}
void ConstantExpr::replaceUsesOfWithOnConstant(Value *From, Value *ToV,
bool DisableChecking) {
assert(isa<Constant>(ToV) && "Cannot make Constant refer to non-constant!");
Constant *To = cast<Constant>(ToV);
Constant *Replacement = 0;
if (getOpcode() == Instruction::GetElementPtr) {
std::vector<Constant*> Indices;
Constant *Pointer = getOperand(0);
Indices.reserve(getNumOperands()-1);
if (Pointer == From) Pointer = To;
for (unsigned i = 1, e = getNumOperands(); i != e; ++i) {
Constant *Val = getOperand(i);
if (Val == From) Val = To;
Indices.push_back(Val);
}
Replacement = ConstantExpr::getGetElementPtr(Pointer, Indices);
} else if (getOpcode() == Instruction::Cast) {
assert(getOperand(0) == From && "Cast only has one use!");
Replacement = ConstantExpr::getCast(To, getType());
} else if (getNumOperands() == 2) {
Constant *C1 = getOperand(0);
Constant *C2 = getOperand(1);
if (C1 == From) C1 = To;
if (C2 == From) C2 = To;
Replacement = ConstantExpr::get(getOpcode(), C1, C2);
} else {
assert(0 && "Unknown ConstantExpr type!");
return;
}
assert(Replacement != this && "I didn't contain From!");
// Everyone using this now uses the replacement...
if (DisableChecking)
uncheckedReplaceAllUsesWith(Replacement);
else
replaceAllUsesWith(Replacement);
// Delete the old constant!
destroyConstant();
}
//===----------------------------------------------------------------------===//
// Factory Function Implementation
// ConstantCreator - A class that is used to create constants by
// ValueMap*. This class should be partially specialized if there is
// something strange that needs to be done to interface to the ctor for the
// constant.
//
namespace llvm {
template<class ConstantClass, class TypeClass, class ValType>
struct ConstantCreator {
static ConstantClass *create(const TypeClass *Ty, const ValType &V) {
return new ConstantClass(Ty, V);
}
};
template<class ConstantClass, class TypeClass>
struct ConvertConstantType {
static void convert(ConstantClass *OldC, const TypeClass *NewTy) {
assert(0 && "This type cannot be converted!\n");
abort();
}
};
}
namespace {
template<class ValType, class TypeClass, class ConstantClass>
class ValueMap : public AbstractTypeUser {
typedef std::pair<const TypeClass*, ValType> MapKey;
typedef std::map<MapKey, ConstantClass *> MapTy;
typedef typename MapTy::iterator MapIterator;
MapTy Map;
typedef std::map<const TypeClass*, MapIterator> AbstractTypeMapTy;
AbstractTypeMapTy AbstractTypeMap;
public:
// getOrCreate - Return the specified constant from the map, creating it if
// necessary.
ConstantClass *getOrCreate(const TypeClass *Ty, const ValType &V) {
MapKey Lookup(Ty, V);
MapIterator I = Map.lower_bound(Lookup);
if (I != Map.end() && I->first == Lookup)
return I->second; // Is it in the map?
// If no preexisting value, create one now...
ConstantClass *Result =
ConstantCreator<ConstantClass,TypeClass,ValType>::create(Ty, V);
/// FIXME: why does this assert fail when loading 176.gcc?
//assert(Result->getType() == Ty && "Type specified is not correct!");
I = Map.insert(I, std::make_pair(MapKey(Ty, V), Result));
// If the type of the constant is abstract, make sure that an entry exists
// for it in the AbstractTypeMap.
if (Ty->isAbstract()) {
typename AbstractTypeMapTy::iterator TI =
AbstractTypeMap.lower_bound(Ty);
if (TI == AbstractTypeMap.end() || TI->first != Ty) {
// Add ourselves to the ATU list of the type.
cast<DerivedType>(Ty)->addAbstractTypeUser(this);
AbstractTypeMap.insert(TI, std::make_pair(Ty, I));
}
}
return Result;
}
void remove(ConstantClass *CP) {
// FIXME: This should not use a linear scan. If this gets to be a
// performance problem, someone should look at this.
MapIterator I = Map.begin();
for (MapIterator E = Map.end(); I != E && I->second != CP; ++I)
/* empty */;
assert(I != Map.end() && "Constant not found in constant table!");
// Now that we found the entry, make sure this isn't the entry that
// the AbstractTypeMap points to.
const TypeClass *Ty = I->first.first;
if (Ty->isAbstract()) {
assert(AbstractTypeMap.count(Ty) &&
"Abstract type not in AbstractTypeMap?");
MapIterator &ATMEntryIt = AbstractTypeMap[Ty];
if (ATMEntryIt == I) {
// Yes, we are removing the representative entry for this type.
// See if there are any other entries of the same type.
MapIterator TmpIt = ATMEntryIt;
// First check the entry before this one...
if (TmpIt != Map.begin()) {
--TmpIt;
if (TmpIt->first.first != Ty) // Not the same type, move back...
++TmpIt;
}
// If we didn't find the same type, try to move forward...
if (TmpIt == ATMEntryIt) {
++TmpIt;
if (TmpIt == Map.end() || TmpIt->first.first != Ty)
--TmpIt; // No entry afterwards with the same type
}
// If there is another entry in the map of the same abstract type,
// update the AbstractTypeMap entry now.
if (TmpIt != ATMEntryIt) {
ATMEntryIt = TmpIt;
} else {
// Otherwise, we are removing the last instance of this type
// from the table. Remove from the ATM, and from user list.
cast<DerivedType>(Ty)->removeAbstractTypeUser(this);
AbstractTypeMap.erase(Ty);
}
}
}
Map.erase(I);
}
void refineAbstractType(const DerivedType *OldTy, const Type *NewTy) {
typename AbstractTypeMapTy::iterator I =
AbstractTypeMap.find(cast<TypeClass>(OldTy));
assert(I != AbstractTypeMap.end() &&
"Abstract type not in AbstractTypeMap?");
// Convert a constant at a time until the last one is gone. The last one
// leaving will remove() itself, causing the AbstractTypeMapEntry to be
// eliminated eventually.
do {
ConvertConstantType<ConstantClass,
TypeClass>::convert(I->second->second,
cast<TypeClass>(NewTy));
I = AbstractTypeMap.find(cast<TypeClass>(OldTy));
} while (I != AbstractTypeMap.end());
}
// If the type became concrete without being refined to any other existing
// type, we just remove ourselves from the ATU list.
void typeBecameConcrete(const DerivedType *AbsTy) {
AbsTy->removeAbstractTypeUser(this);
}
void dump() const {
std::cerr << "Constant.cpp: ValueMap\n";
}
};
}
//---- ConstantUInt::get() and ConstantSInt::get() implementations...
//
static ValueMap< int64_t, Type, ConstantSInt> SIntConstants;
static ValueMap<uint64_t, Type, ConstantUInt> UIntConstants;
ConstantSInt *ConstantSInt::get(const Type *Ty, int64_t V) {
return SIntConstants.getOrCreate(Ty, V);
}
ConstantUInt *ConstantUInt::get(const Type *Ty, uint64_t V) {
return UIntConstants.getOrCreate(Ty, V);
}
ConstantInt *ConstantInt::get(const Type *Ty, unsigned char V) {
assert(V <= 127 && "Can only be used with very small positive constants!");
if (Ty->isSigned()) return ConstantSInt::get(Ty, V);
return ConstantUInt::get(Ty, V);
}
//---- ConstantFP::get() implementation...
//
namespace llvm {
template<>
struct ConstantCreator<ConstantFP, Type, uint64_t> {
static ConstantFP *create(const Type *Ty, uint64_t V) {
assert(Ty == Type::DoubleTy);
union {
double F;
uint64_t I;
} T;
T.I = V;
return new ConstantFP(Ty, T.F);
}
};
template<>
struct ConstantCreator<ConstantFP, Type, uint32_t> {
static ConstantFP *create(const Type *Ty, uint32_t V) {
assert(Ty == Type::FloatTy);
union {
float F;
uint32_t I;
} T;
T.I = V;
return new ConstantFP(Ty, T.F);
}
};
}
static ValueMap<uint64_t, Type, ConstantFP> DoubleConstants;
static ValueMap<uint32_t, Type, ConstantFP> FloatConstants;
ConstantFP *ConstantFP::get(const Type *Ty, double V) {
if (Ty == Type::FloatTy) {
// Force the value through memory to normalize it.
union {
float F;
uint32_t I;
} T;
T.F = (float)V;
return FloatConstants.getOrCreate(Ty, T.I);
} else {
assert(Ty == Type::DoubleTy);
union {
double F;
uint64_t I;
} T;
T.F = V;
return DoubleConstants.getOrCreate(Ty, T.I);
}
}
//---- ConstantArray::get() implementation...
//
namespace llvm {
template<>
struct ConvertConstantType<ConstantArray, ArrayType> {
static void convert(ConstantArray *OldC, const ArrayType *NewTy) {
// Make everyone now use a constant of the new type...
std::vector<Constant*> C;
for (unsigned i = 0, e = OldC->getNumOperands(); i != e; ++i)
C.push_back(cast<Constant>(OldC->getOperand(i)));
Constant *New = ConstantArray::get(NewTy, C);
assert(New != OldC && "Didn't replace constant??");
OldC->uncheckedReplaceAllUsesWith(New);
OldC->destroyConstant(); // This constant is now dead, destroy it.
}
};
}
static ValueMap<std::vector<Constant*>, ArrayType,
ConstantArray> ArrayConstants;
ConstantArray *ConstantArray::get(const ArrayType *Ty,
const std::vector<Constant*> &V) {
return ArrayConstants.getOrCreate(Ty, V);
}
// destroyConstant - Remove the constant from the constant table...
//
void ConstantArray::destroyConstant() {
ArrayConstants.remove(this);
destroyConstantImpl();
}
// ConstantArray::get(const string&) - Return an array that is initialized to
// contain the specified string. A null terminator is added to the specified
// string so that it may be used in a natural way...
//
ConstantArray *ConstantArray::get(const std::string &Str) {
std::vector<Constant*> ElementVals;
for (unsigned i = 0; i < Str.length(); ++i)
ElementVals.push_back(ConstantSInt::get(Type::SByteTy, Str[i]));
// Add a null terminator to the string...
ElementVals.push_back(ConstantSInt::get(Type::SByteTy, 0));
ArrayType *ATy = ArrayType::get(Type::SByteTy, Str.length()+1);
return ConstantArray::get(ATy, ElementVals);
}
/// isString - This method returns true if the array is an array of sbyte or
/// ubyte, and if the elements of the array are all ConstantInt's.
bool ConstantArray::isString() const {
// Check the element type for sbyte or ubyte...
if (getType()->getElementType() != Type::UByteTy &&
getType()->getElementType() != Type::SByteTy)
return false;
// Check the elements to make sure they are all integers, not constant
// expressions.
for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
if (!isa<ConstantInt>(getOperand(i)))
return false;
return true;
}
// getAsString - If the sub-element type of this array is either sbyte or ubyte,
// then this method converts the array to an std::string and returns it.
// Otherwise, it asserts out.
//
std::string ConstantArray::getAsString() const {
assert(isString() && "Not a string!");
std::string Result;
for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
Result += (char)cast<ConstantInt>(getOperand(i))->getRawValue();
return Result;
}
//---- ConstantStruct::get() implementation...
//
namespace llvm {
template<>
struct ConvertConstantType<ConstantStruct, StructType> {
static void convert(ConstantStruct *OldC, const StructType *NewTy) {
// Make everyone now use a constant of the new type...
std::vector<Constant*> C;
for (unsigned i = 0, e = OldC->getNumOperands(); i != e; ++i)
C.push_back(cast<Constant>(OldC->getOperand(i)));
Constant *New = ConstantStruct::get(NewTy, C);
assert(New != OldC && "Didn't replace constant??");
OldC->uncheckedReplaceAllUsesWith(New);
OldC->destroyConstant(); // This constant is now dead, destroy it.
}
};
}
static ValueMap<std::vector<Constant*>, StructType,
ConstantStruct> StructConstants;
ConstantStruct *ConstantStruct::get(const StructType *Ty,
const std::vector<Constant*> &V) {
return StructConstants.getOrCreate(Ty, V);
}
// destroyConstant - Remove the constant from the constant table...
//
void ConstantStruct::destroyConstant() {
StructConstants.remove(this);
destroyConstantImpl();
}
//---- ConstantPointerNull::get() implementation...
//
namespace llvm {
// ConstantPointerNull does not take extra "value" argument...
template<class ValType>
struct ConstantCreator<ConstantPointerNull, PointerType, ValType> {
static ConstantPointerNull *create(const PointerType *Ty, const ValType &V){
return new ConstantPointerNull(Ty);
}
};
template<>
struct ConvertConstantType<ConstantPointerNull, PointerType> {
static void convert(ConstantPointerNull *OldC, const PointerType *NewTy) {
// Make everyone now use a constant of the new type...
Constant *New = ConstantPointerNull::get(NewTy);
assert(New != OldC && "Didn't replace constant??");
OldC->uncheckedReplaceAllUsesWith(New);
OldC->destroyConstant(); // This constant is now dead, destroy it.
}
};
}
static ValueMap<char, PointerType, ConstantPointerNull> NullPtrConstants;
ConstantPointerNull *ConstantPointerNull::get(const PointerType *Ty) {
return NullPtrConstants.getOrCreate(Ty, 0);
}
// destroyConstant - Remove the constant from the constant table...
//
void ConstantPointerNull::destroyConstant() {
NullPtrConstants.remove(this);
destroyConstantImpl();
}
//---- ConstantPointerRef::get() implementation...
//
ConstantPointerRef *ConstantPointerRef::get(GlobalValue *GV) {
assert(GV->getParent() && "Global Value must be attached to a module!");
// The Module handles the pointer reference sharing...
return GV->getParent()->getConstantPointerRef(GV);
}
// destroyConstant - Remove the constant from the constant table...
//
void ConstantPointerRef::destroyConstant() {
getValue()->getParent()->destroyConstantPointerRef(this);
destroyConstantImpl();
}
//---- ConstantExpr::get() implementations...
//
typedef std::pair<unsigned, std::vector<Constant*> > ExprMapKeyType;
namespace llvm {
template<>
struct ConstantCreator<ConstantExpr, Type, ExprMapKeyType> {
static ConstantExpr *create(const Type *Ty, const ExprMapKeyType &V) {
if (V.first == Instruction::Cast)
return new ConstantExpr(Instruction::Cast, V.second[0], Ty);
if ((V.first >= Instruction::BinaryOpsBegin &&
V.first < Instruction::BinaryOpsEnd) ||
V.first == Instruction::Shl || V.first == Instruction::Shr)
return new ConstantExpr(V.first, V.second[0], V.second[1]);
assert(V.first == Instruction::GetElementPtr && "Invalid ConstantExpr!");
std::vector<Constant*> IdxList(V.second.begin()+1, V.second.end());
return new ConstantExpr(V.second[0], IdxList, Ty);
}
};
template<>
struct ConvertConstantType<ConstantExpr, Type> {
static void convert(ConstantExpr *OldC, const Type *NewTy) {
Constant *New;
switch (OldC->getOpcode()) {
case Instruction::Cast:
New = ConstantExpr::getCast(OldC->getOperand(0), NewTy);
break;
case Instruction::Shl:
case Instruction::Shr:
New = ConstantExpr::getShiftTy(NewTy, OldC->getOpcode(),
OldC->getOperand(0), OldC->getOperand(1));
break;
default:
assert(OldC->getOpcode() >= Instruction::BinaryOpsBegin &&
OldC->getOpcode() < Instruction::BinaryOpsEnd);
New = ConstantExpr::getTy(NewTy, OldC->getOpcode(), OldC->getOperand(0),
OldC->getOperand(1));
break;
case Instruction::GetElementPtr:
// Make everyone now use a constant of the new type...
std::vector<Constant*> C;
for (unsigned i = 1, e = OldC->getNumOperands(); i != e; ++i)
C.push_back(cast<Constant>(OldC->getOperand(i)));
New = ConstantExpr::getGetElementPtrTy(NewTy, OldC->getOperand(0), C);
break;
}
assert(New != OldC && "Didn't replace constant??");
OldC->uncheckedReplaceAllUsesWith(New);
OldC->destroyConstant(); // This constant is now dead, destroy it.
}
};
} // end namespace llvm
static ValueMap<ExprMapKeyType, Type, ConstantExpr> ExprConstants;
Constant *ConstantExpr::getCast(Constant *C, const Type *Ty) {
assert(Ty->isFirstClassType() && "Cannot cast to an aggregate type!");
if (Constant *FC = ConstantFoldCastInstruction(C, Ty))
return FC; // Fold a few common cases...
// Look up the constant in the table first to ensure uniqueness
std::vector<Constant*> argVec(1, C);
ExprMapKeyType Key = std::make_pair(Instruction::Cast, argVec);
return ExprConstants.getOrCreate(Ty, Key);
}
Constant *ConstantExpr::getTy(const Type *ReqTy, unsigned Opcode,
Constant *C1, Constant *C2) {
if (Opcode == Instruction::Shl || Opcode == Instruction::Shr)
return getShiftTy(ReqTy, Opcode, C1, C2);
// Check the operands for consistency first
assert((Opcode >= Instruction::BinaryOpsBegin &&
Opcode < Instruction::BinaryOpsEnd) &&
"Invalid opcode in binary constant expression");
assert(C1->getType() == C2->getType() &&
"Operand types in binary constant expression should match");
if (ReqTy == C1->getType())
if (Constant *FC = ConstantFoldBinaryInstruction(Opcode, C1, C2))
return FC; // Fold a few common cases...
std::vector<Constant*> argVec(1, C1); argVec.push_back(C2);
ExprMapKeyType Key = std::make_pair(Opcode, argVec);
return ExprConstants.getOrCreate(ReqTy, Key);
}
/// getShiftTy - Return a shift left or shift right constant expr
Constant *ConstantExpr::getShiftTy(const Type *ReqTy, unsigned Opcode,
Constant *C1, Constant *C2) {
// Check the operands for consistency first
assert((Opcode == Instruction::Shl ||
Opcode == Instruction::Shr) &&
"Invalid opcode in binary constant expression");
assert(C1->getType()->isIntegral() && C2->getType() == Type::UByteTy &&
"Invalid operand types for Shift constant expr!");
if (Constant *FC = ConstantFoldBinaryInstruction(Opcode, C1, C2))
return FC; // Fold a few common cases...
// Look up the constant in the table first to ensure uniqueness
std::vector<Constant*> argVec(1, C1); argVec.push_back(C2);
ExprMapKeyType Key = std::make_pair(Opcode, argVec);
return ExprConstants.getOrCreate(ReqTy, Key);
}
Constant *ConstantExpr::getGetElementPtrTy(const Type *ReqTy, Constant *C,
const std::vector<Constant*> &IdxList) {
if (Constant *FC = ConstantFoldGetElementPtr(C, IdxList))
return FC; // Fold a few common cases...
assert(isa<PointerType>(C->getType()) &&
"Non-pointer type for constant GetElementPtr expression");
// Look up the constant in the table first to ensure uniqueness
std::vector<Constant*> argVec(1, C);
argVec.insert(argVec.end(), IdxList.begin(), IdxList.end());
const ExprMapKeyType &Key = std::make_pair(Instruction::GetElementPtr,argVec);
return ExprConstants.getOrCreate(ReqTy, Key);
}
Constant *ConstantExpr::getGetElementPtr(Constant *C,
const std::vector<Constant*> &IdxList){
// Get the result type of the getelementptr!
std::vector<Value*> VIdxList(IdxList.begin(), IdxList.end());
const Type *Ty = GetElementPtrInst::getIndexedType(C->getType(), VIdxList,
true);
assert(Ty && "GEP indices invalid!");
if (C->isNullValue()) {
bool isNull = true;
for (unsigned i = 0, e = IdxList.size(); i != e; ++i)
if (!IdxList[i]->isNullValue()) {
isNull = false;
break;
}
if (isNull) return ConstantPointerNull::get(PointerType::get(Ty));
}
return getGetElementPtrTy(PointerType::get(Ty), C, IdxList);
}
// destroyConstant - Remove the constant from the constant table...
//
void ConstantExpr::destroyConstant() {
ExprConstants.remove(this);
destroyConstantImpl();
}
const char *ConstantExpr::getOpcodeName() const {
return Instruction::getOpcodeName(getOpcode());
}
unsigned Constant::mutateReferences(Value *OldV, Value *NewV) {
// Uses of constant pointer refs are global values, not constants!
if (ConstantPointerRef *CPR = dyn_cast<ConstantPointerRef>(this)) {
GlobalValue *NewGV = cast<GlobalValue>(NewV);
GlobalValue *OldGV = CPR->getValue();
assert(OldGV == OldV && "Cannot mutate old value if I'm not using it!");
Operands[0] = NewGV;
OldGV->getParent()->mutateConstantPointerRef(OldGV, NewGV);
return 1;
} else {
Constant *NewC = cast<Constant>(NewV);
unsigned NumReplaced = 0;
for (unsigned i = 0, N = getNumOperands(); i != N; ++i)
if (Operands[i] == OldV) {
++NumReplaced;
Operands[i] = NewC;
}
return NumReplaced;
}
}