llvm/lib/VMCore/Constants.cpp
2002-04-07 22:32:25 +00:00

530 lines
17 KiB
C++

//===-- ConstantVals.cpp - Implement Constant nodes --------------*- C++ -*--=//
//
// This file implements the Constant* classes...
//
//===----------------------------------------------------------------------===//
#define __STDC_LIMIT_MACROS // Get defs for INT64_MAX and friends...
#include "llvm/ConstantVals.h"
#include "llvm/DerivedTypes.h"
#include "llvm/SymbolTable.h"
#include "llvm/GlobalValue.h"
#include "llvm/Module.h"
#include "llvm/Analysis/SlotCalculator.h"
#include "Support/StringExtras.h"
#include <algorithm>
using std::map;
using std::pair;
using std::make_pair;
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);
}
// Static constructor to create a '0' constant of arbitrary type...
Constant *Constant::getNullConstant(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;
}
}
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: ";
dump();
std::cerr << "\nUse still stuck around after Def is destroyed: ";
V->dump();
std::cerr << "\n";
}
#endif
assert(isa<Constant>(V) && "References remain to ConstantPointerRef!");
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;
}
//===----------------------------------------------------------------------===//
// ConstantXXX Classes
//===----------------------------------------------------------------------===//
//===----------------------------------------------------------------------===//
// Normal Constructors
ConstantBool::ConstantBool(bool V) : Constant(Type::BoolTy) {
Val = V;
}
ConstantInt::ConstantInt(const Type *Ty, uint64_t V) : Constant(Ty) {
Val.Unsigned = V;
}
ConstantSInt::ConstantSInt(const Type *Ty, int64_t V) : ConstantInt(Ty, V) {
assert(isValueValidForType(Ty, V) && "Value too large for type!");
}
ConstantUInt::ConstantUInt(const Type *Ty, uint64_t V) : ConstantInt(Ty, V) {
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) {
for (unsigned i = 0; i < V.size(); 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();
for (unsigned i = 0; i < V.size(); 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));
}
//===----------------------------------------------------------------------===//
// getStrValue implementations
std::string ConstantBool::getStrValue() const {
return Val ? "true" : "false";
}
std::string ConstantSInt::getStrValue() const {
return itostr(Val.Signed);
}
std::string ConstantUInt::getStrValue() const {
return utostr(Val.Unsigned);
}
// ConstantFP::getStrValue - We would like to output the FP constant value in
// exponential notation, but we cannot do this if doing so will lose precision.
// Check here to make sure that we only output it in exponential format if we
// can parse the value back and get the same value.
//
std::string ConstantFP::getStrValue() const {
std::string StrVal = ftostr(Val);
// Check to make sure that the stringized number is not some string like "Inf"
// or NaN, that atof will accept, but the lexer will not. Check that the
// string matches the "[-+]?[0-9]" regex.
//
if ((StrVal[0] >= '0' && StrVal[0] <= '9') ||
((StrVal[0] == '-' || StrVal[0] == '+') &&
(StrVal[0] >= '0' && StrVal[0] <= '9'))) {
double TestVal = atof(StrVal.c_str()); // Reparse stringized version!
if (TestVal == Val)
return StrVal;
}
// Otherwise we could not reparse it to exactly the same value, so we must
// output the string in hexadecimal format!
//
// Behave nicely in the face of C TBAA rules... see:
// http://www.nullstone.com/htmls/category/aliastyp.htm
//
char *Ptr = (char*)&Val;
assert(sizeof(double) == sizeof(uint64_t) && sizeof(double) == 8 &&
"assuming that double is 64 bits!");
return "0x"+utohexstr(*(uint64_t*)Ptr);
}
std::string ConstantArray::getStrValue() const {
std::string Result;
// As a special case, print the array as a string if it is an array of
// ubytes or an array of sbytes with positive values.
//
const Type *ETy = cast<ArrayType>(getType())->getElementType();
bool isString = (ETy == Type::SByteTy || ETy == Type::UByteTy);
if (ETy == Type::SByteTy) {
for (unsigned i = 0; i < Operands.size(); ++i)
if (ETy == Type::SByteTy &&
cast<ConstantSInt>(Operands[i])->getValue() < 0) {
isString = false;
break;
}
}
if (isString) {
Result = "c\"";
for (unsigned i = 0; i < Operands.size(); ++i) {
unsigned char C = (ETy == Type::SByteTy) ?
(unsigned char)cast<ConstantSInt>(Operands[i])->getValue() :
(unsigned char)cast<ConstantUInt>(Operands[i])->getValue();
if (isprint(C)) {
Result += C;
} else {
Result += '\\';
Result += ( C/16 < 10) ? ( C/16 +'0') : ( C/16 -10+'A');
Result += ((C&15) < 10) ? ((C&15)+'0') : ((C&15)-10+'A');
}
}
Result += "\"";
} else {
Result = "[";
if (Operands.size()) {
Result += " " + Operands[0]->getType()->getDescription() +
" " + cast<Constant>(Operands[0])->getStrValue();
for (unsigned i = 1; i < Operands.size(); i++)
Result += ", " + Operands[i]->getType()->getDescription() +
" " + cast<Constant>(Operands[i])->getStrValue();
}
Result += " ]";
}
return Result;
}
std::string ConstantStruct::getStrValue() const {
std::string Result = "{";
if (Operands.size()) {
Result += " " + Operands[0]->getType()->getDescription() +
" " + cast<Constant>(Operands[0])->getStrValue();
for (unsigned i = 1; i < Operands.size(); i++)
Result += ", " + Operands[i]->getType()->getDescription() +
" " + cast<Constant>(Operands[i])->getStrValue();
}
return Result + " }";
}
std::string ConstantPointerNull::getStrValue() const {
return "null";
}
std::string ConstantPointerRef::getStrValue() const {
const GlobalValue *V = getValue();
if (V->hasName()) return "%" + V->getName();
SlotCalculator *Table = new SlotCalculator(V->getParent(), true);
int Slot = Table->getValSlot(V);
delete Table;
if (Slot >= 0) return std::string(" %") + itostr(Slot);
else return "<pointer reference badref>";
}
//===----------------------------------------------------------------------===//
// classof implementations
bool ConstantInt::classof(const Constant *CPV) {
return CPV->getType()->isIntegral();
}
bool ConstantSInt::classof(const Constant *CPV) {
return CPV->getType()->isSigned();
}
bool ConstantUInt::classof(const Constant *CPV) {
return CPV->getType()->isUnsigned();
}
bool ConstantFP::classof(const Constant *CPV) {
const Type *Ty = CPV->getType();
return Ty == Type::FloatTy || Ty == Type::DoubleTy;
}
bool ConstantArray::classof(const Constant *CPV) {
return isa<ArrayType>(CPV->getType());
}
bool ConstantStruct::classof(const Constant *CPV) {
return isa<StructType>(CPV->getType());
}
bool ConstantPointer::classof(const Constant *CPV) {
return isa<PointerType>(CPV->getType());
}
//===----------------------------------------------------------------------===//
// 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...
}
};
//===----------------------------------------------------------------------===//
// Hash Function Implementations
#if 0
unsigned ConstantSInt::hash(const Type *Ty, int64_t V) {
return unsigned(Ty->getPrimitiveID() ^ V);
}
unsigned ConstantUInt::hash(const Type *Ty, uint64_t V) {
return unsigned(Ty->getPrimitiveID() ^ V);
}
unsigned ConstantFP::hash(const Type *Ty, double V) {
return Ty->getPrimitiveID() ^ unsigned(V);
}
unsigned ConstantArray::hash(const ArrayType *Ty,
const std::vector<Constant*> &V) {
unsigned Result = (Ty->getUniqueID() << 5) ^ (Ty->getUniqueID() * 7);
for (unsigned i = 0; i < V.size(); ++i)
Result ^= V[i]->getHash() << (i & 7);
return Result;
}
unsigned ConstantStruct::hash(const StructType *Ty,
const std::vector<Constant*> &V) {
unsigned Result = (Ty->getUniqueID() << 5) ^ (Ty->getUniqueID() * 7);
for (unsigned i = 0; i < V.size(); ++i)
Result ^= V[i]->getHash() << (i & 7);
return Result;
}
#endif
//===----------------------------------------------------------------------===//
// 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) {
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 (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();
}
//---- 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;
}
//---- 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);
}
void ConstantPointerRef::mutateReference(GlobalValue *NewGV) {
getValue()->getParent()->mutateConstantPointerRef(getValue(), NewGV);
Operands[0] = NewGV;
}