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llvm-project/llvm/lib/VMCore/Constants.cpp

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//===-- Constants.cpp - Implement Constant nodes -----------------*- C++ -*--=//
//
// This file implements the Constant* classes...
//
//===----------------------------------------------------------------------===//
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/iMemory.h"
#include "llvm/SymbolTable.h"
#include "llvm/Module.h"
#include "llvm/SlotCalculator.h"
#include "Support/StringExtras.h"
#include <algorithm>
using std::map;
using std::pair;
using std::make_pair;
using std::vector;
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 dependant 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 constructor to create a '0' constant of arbitrary type...
Constant *Constant::getNullValue(const Type *Ty) {
switch (Ty->getPrimitiveID()) {
case Type::BoolTyID: return ConstantBool::get(false);
case Type::SByteTyID:
case Type::ShortTyID:
case Type::IntTyID:
case Type::LongTyID: return ConstantSInt::get(Ty, 0);
case Type::UByteTyID:
case Type::UShortTyID:
case Type::UIntTyID:
case Type::ULongTyID: return ConstantUInt::get(Ty, 0);
case Type::FloatTyID:
case Type::DoubleTyID: return ConstantFP::get(Ty, 0);
case Type::PointerTyID:
return ConstantPointerNull::get(cast<PointerType>(Ty));
default:
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;
}
}
//===----------------------------------------------------------------------===//
// 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());
Operands.push_back(Use(V[i], this));
}
}
ConstantStruct::ConstantStruct(const StructType *T,
const std::vector<Constant*> &V) : Constant(T) {
const StructType::ElementTypes &ETypes = T->getElementTypes();
assert(V.size() == ETypes.size() &&
"Invalid initializer vector for constant structure");
Operands.reserve(V.size());
for (unsigned i = 0, e = V.size(); i != e; ++i) {
assert(V[i]->getType() == ETypes[i]);
Operands.push_back(Use(V[i], this));
}
}
ConstantPointerRef::ConstantPointerRef(GlobalValue *GV)
: ConstantPointer(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));
}
ConstantExpr::ConstantExpr(unsigned Opcode, Constant *C1, Constant *C2)
: Constant(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 ConstantPointer::classof(const Constant *CPV) {
return (isa<PointerType>(CPV->getType()) && !isa<ConstantExpr>(CPV));
}
//===----------------------------------------------------------------------===//
// 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:
/*
return (Val <= UINT8_MAX);
*/
case Type::DoubleTyID:
return true; // This is the largest type...
}
};
//===----------------------------------------------------------------------===//
// replaceUsesOfWithOnConstant implementations
void ConstantArray::replaceUsesOfWithOnConstant(Value *From, Value *To) {
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);
}
ConstantArray *Replacement = ConstantArray::get(getType(), Values);
assert(Replacement != this && "I didn't contain From!");
// Everyone using this now uses the replacement...
replaceAllUsesWith(Replacement);
// Delete the old constant!
destroyConstant();
}
void ConstantStruct::replaceUsesOfWithOnConstant(Value *From, Value *To) {
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);
}
ConstantStruct *Replacement = ConstantStruct::get(getType(), Values);
assert(Replacement != this && "I didn't contain From!");
// Everyone using this now uses the replacement...
replaceAllUsesWith(Replacement);
// Delete the old constant!
destroyConstant();
}
void ConstantPointerRef::replaceUsesOfWithOnConstant(Value *From, Value *To) {
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...
replaceAllUsesWith(Replacement);
// Delete the old constant!
destroyConstant();
} else {
// Just replace ourselves with the To value specified.
replaceAllUsesWith(To);
// Delete the old constant!
destroyConstant();
}
}
void ConstantExpr::replaceUsesOfWithOnConstant(Value *From, Value *To) {
assert(isa<Constant>(To) && "Cannot make Constant refer to non-constant!");
ConstantExpr *Replacement = 0;
if (getOpcode() == Instruction::GetElementPtr) {
std::vector<Constant*> Indices;
Constant *Pointer = cast<Constant>(getOperand(0));
Indices.reserve(getNumOperands()-1);
if (Pointer == From) Pointer = cast<Constant>(To);
for (unsigned i = 1, e = getNumOperands(); i != e; ++i) {
Constant *Val = cast<Constant>(getOperand(i));
if (Val == From) Val = cast<Constant>(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(cast<Constant>(To), getType());
} else if (getNumOperands() == 2) {
Constant *C1 = cast<Constant>(getOperand(0));
Constant *C2 = cast<Constant>(getOperand(1));
if (C1 == From) C1 = cast<Constant>(To);
if (C2 == From) C2 = cast<Constant>(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...
replaceAllUsesWith(Replacement);
// Delete the old constant!
destroyConstant();
}
//===----------------------------------------------------------------------===//
// Factory Function Implementation
template<class ValType, class ConstantClass>
struct ValueMap {
typedef pair<const Type*, ValType> ConstHashKey;
map<ConstHashKey, ConstantClass *> Map;
inline ConstantClass *get(const Type *Ty, ValType V) {
typename map<ConstHashKey,ConstantClass *>::iterator I =
Map.find(ConstHashKey(Ty, V));
return (I != Map.end()) ? I->second : 0;
}
inline void add(const Type *Ty, ValType V, ConstantClass *CP) {
Map.insert(make_pair(ConstHashKey(Ty, V), CP));
}
inline void remove(ConstantClass *CP) {
for (typename map<ConstHashKey,ConstantClass *>::iterator I = Map.begin(),
E = Map.end(); I != E;++I)
if (I->second == CP) {
Map.erase(I);
return;
}
}
};
//---- ConstantUInt::get() and ConstantSInt::get() implementations...
//
static ValueMap<uint64_t, ConstantInt> IntConstants;
ConstantSInt *ConstantSInt::get(const Type *Ty, int64_t V) {
ConstantSInt *Result = (ConstantSInt*)IntConstants.get(Ty, (uint64_t)V);
if (!Result) // If no preexisting value, create one now...
IntConstants.add(Ty, V, Result = new ConstantSInt(Ty, V));
return Result;
}
ConstantUInt *ConstantUInt::get(const Type *Ty, uint64_t V) {
ConstantUInt *Result = (ConstantUInt*)IntConstants.get(Ty, V);
if (!Result) // If no preexisting value, create one now...
IntConstants.add(Ty, V, Result = new ConstantUInt(Ty, V));
return Result;
}
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...
//
static ValueMap<double, ConstantFP> FPConstants;
ConstantFP *ConstantFP::get(const Type *Ty, double V) {
ConstantFP *Result = FPConstants.get(Ty, V);
if (!Result) // If no preexisting value, create one now...
FPConstants.add(Ty, V, Result = new ConstantFP(Ty, V));
return Result;
}
//---- ConstantArray::get() implementation...
//
static ValueMap<std::vector<Constant*>, ConstantArray> ArrayConstants;
ConstantArray *ConstantArray::get(const ArrayType *Ty,
const std::vector<Constant*> &V) {
ConstantArray *Result = ArrayConstants.get(Ty, V);
if (!Result) // If no preexisting value, create one now...
ArrayConstants.add(Ty, V, Result = new ConstantArray(Ty, V));
return Result;
}
// 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);
}
// destroyConstant - Remove the constant from the constant table...
//
void ConstantArray::destroyConstant() {
ArrayConstants.remove(this);
destroyConstantImpl();
}
// 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 {
std::string Result;
if (getType()->getElementType() == Type::SByteTy)
for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
Result += (char)cast<ConstantSInt>(getOperand(i))->getValue();
else {
assert(getType()->getElementType() == Type::UByteTy && "Not a string!");
for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
Result += (char)cast<ConstantUInt>(getOperand(i))->getValue();
}
return Result;
}
//---- ConstantStruct::get() implementation...
//
static ValueMap<std::vector<Constant*>, ConstantStruct> StructConstants;
ConstantStruct *ConstantStruct::get(const StructType *Ty,
const std::vector<Constant*> &V) {
ConstantStruct *Result = StructConstants.get(Ty, V);
if (!Result) // If no preexisting value, create one now...
StructConstants.add(Ty, V, Result = new ConstantStruct(Ty, V));
return Result;
}
// destroyConstant - Remove the constant from the constant table...
//
void ConstantStruct::destroyConstant() {
StructConstants.remove(this);
destroyConstantImpl();
}
//---- ConstantPointerNull::get() implementation...
//
static ValueMap<char, ConstantPointerNull> NullPtrConstants;
ConstantPointerNull *ConstantPointerNull::get(const PointerType *Ty) {
ConstantPointerNull *Result = NullPtrConstants.get(Ty, 0);
if (!Result) // If no preexisting value, create one now...
NullPtrConstants.add(Ty, 0, Result = new ConstantPointerNull(Ty));
return Result;
}
// 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 pair<unsigned, vector<Constant*> > ExprMapKeyType;
static ValueMap<const ExprMapKeyType, ConstantExpr> ExprConstants;
ConstantExpr *ConstantExpr::getCast(Constant *C, const Type *Ty) {
// Look up the constant in the table first to ensure uniqueness
vector<Constant*> argVec(1, C);
const ExprMapKeyType &Key = make_pair(Instruction::Cast, argVec);
ConstantExpr *Result = ExprConstants.get(Ty, Key);
if (Result) return Result;
// Its not in the table so create a new one and put it in the table.
Result = new ConstantExpr(Instruction::Cast, C, Ty);
ExprConstants.add(Ty, Key, Result);
return Result;
}
ConstantExpr *ConstantExpr::get(unsigned Opcode, Constant *C1, Constant *C2) {
// Look up the constant in the table first to ensure uniqueness
vector<Constant*> argVec(1, C1); argVec.push_back(C2);
const ExprMapKeyType &Key = make_pair(Opcode, argVec);
ConstantExpr *Result = ExprConstants.get(C1->getType(), Key);
if (Result) return Result;
// Its not in the table so create a new one and put it in the table.
// 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");
Result = new ConstantExpr(Opcode, C1, C2);
ExprConstants.add(C1->getType(), Key, Result);
return Result;
}
ConstantExpr *ConstantExpr::getGetElementPtr(Constant *C,
const std::vector<Constant*> &IdxList) {
const Type *Ty = C->getType();
// Look up the constant in the table first to ensure uniqueness
vector<Constant*> argVec(1, C);
argVec.insert(argVec.end(), IdxList.begin(), IdxList.end());
const ExprMapKeyType &Key = make_pair(Instruction::GetElementPtr, argVec);
ConstantExpr *Result = ExprConstants.get(Ty, Key);
if (Result) return Result;
// Its not in the table so create a new one and put it in the table.
// Check the operands for consistency first
//
assert(isa<PointerType>(Ty) &&
"Non-pointer type for constant GelElementPtr expression");
// Check that the indices list is valid...
std::vector<Value*> ValIdxList(IdxList.begin(), IdxList.end());
const Type *DestTy = GetElementPtrInst::getIndexedType(Ty, ValIdxList, true);
assert(DestTy && "Invalid index list for constant GelElementPtr expression");
Result = new ConstantExpr(C, IdxList, PointerType::get(DestTy));
ExprConstants.add(Ty, Key, Result);
return Result;
}
// 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!");
OldGV->getParent()->mutateConstantPointerRef(OldGV, NewGV);
Operands[0] = 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;
}
}
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