//
// 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 is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
-// This file implements the Value and User classes.
+// This file implements the Value, ValueHandle, and User classes.
//
//===----------------------------------------------------------------------===//
+#include "LLVMContextImpl.h"
#include "llvm/Constant.h"
+#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/InstrTypes.h"
+#include "llvm/Instructions.h"
+#include "llvm/Operator.h"
#include "llvm/Module.h"
#include "llvm/ValueSymbolTable.h"
+#include "llvm/ADT/SmallString.h"
#include "llvm/Support/Debug.h"
+#include "llvm/Support/GetElementPtrTypeIterator.h"
+#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/LeakDetector.h"
-#include "llvm/Constants.h"
-#include "llvm/InlineAsm.h"
-#include "llvm/Instructions.h"
-#include "llvm/IntrinsicInst.h"
-#include "llvm/InstrTypes.h"
+#include "llvm/Support/ManagedStatic.h"
+#include "llvm/Support/ValueHandle.h"
+#include "llvm/ADT/DenseMap.h"
#include <algorithm>
using namespace llvm;
// Value Class
//===----------------------------------------------------------------------===//
-static inline const Type *checkType(const Type *Ty) {
+static inline Type *checkType(Type *Ty) {
assert(Ty && "Value defined with a null type: Error!");
- return Ty;
+ return const_cast<Type*>(Ty);
}
-Value::Value(const Type *ty, unsigned scid)
- : SubclassID(scid), SubclassData(0), Ty(checkType(ty)),
+Value::Value(Type *ty, unsigned scid)
+ : SubclassID(scid), HasValueHandle(0),
+ SubclassOptionalData(0), SubclassData(0), VTy((Type*)checkType(ty)),
UseList(0), Name(0) {
- if (!isa<Constant>(this) && !isa<BasicBlock>(this))
- assert((Ty->isFirstClassType() || Ty == Type::VoidTy ||
- isa<OpaqueType>(ty)) &&
+ // FIXME: Why isn't this in the subclass gunk??
+ if (isa<CallInst>(this) || isa<InvokeInst>(this))
+ assert((VTy->isFirstClassType() || VTy->isVoidTy() || VTy->isStructTy()) &&
+ "invalid CallInst type!");
+ else if (!isa<Constant>(this) && !isa<BasicBlock>(this))
+ assert((VTy->isFirstClassType() || VTy->isVoidTy()) &&
"Cannot create non-first-class values except for constants!");
}
-Value::~Value()
-{
- switch(SubclassID)
- {
- case ArgumentVal:
- Argument::destroyThis(cast<Argument>(this));
- break;
- case BasicBlockVal:
- BasicBlock::destroyThis(cast<BasicBlock>(this));
- break;
- case FunctionVal:
- Function::destroyThis(cast<Function>(this));
- break;
- case GlobalAliasVal:
- GlobalAlias::destroyThis(cast<GlobalAlias>(this));
- break;
- case GlobalVariableVal:
- GlobalVariable::destroyThis(cast<GlobalVariable>(this));
- break;
- case UndefValueVal:
- UndefValue::destroyThis(cast<UndefValue>(this));
- break;
- case ConstantExprVal:
- {
- ConstantExpr* CE = dyn_cast<ConstantExpr>(this);
- if(CE->getOpcode() == Instruction::GetElementPtr)
- {
- GetElementPtrConstantExpr* GECE =
- dyn_cast<GetElementPtrConstantExpr>(CE);
- GetElementPtrConstantExpr::destroyThis(GECE);
- }
- else if(CE->getOpcode() == Instruction::ExtractElement)
- {
- ExtractElementConstantExpr* EECE =
- dyn_cast<ExtractElementConstantExpr>(CE);
- ExtractElementConstantExpr::destroyThis(EECE);
- }
- else if(CE->getOpcode() == Instruction::InsertElement)
- {
- InsertElementConstantExpr* IECE =
- dyn_cast<InsertElementConstantExpr>(CE);
- InsertElementConstantExpr::destroyThis(IECE);
- }
- else if(CE->getOpcode() == Instruction::Select)
- {
- SelectConstantExpr* SCE = dyn_cast<SelectConstantExpr>(CE);
- SelectConstantExpr::destroyThis(SCE);
- }
- else if(CE->getOpcode() == Instruction::ShuffleVector)
- {
- ShuffleVectorConstantExpr* SVCE =
- dyn_cast<ShuffleVectorConstantExpr>(CE);
- ShuffleVectorConstantExpr::destroyThis(SVCE);
- }
- else if(BinaryConstantExpr* BCE = dyn_cast<BinaryConstantExpr>(this))
- BinaryConstantExpr::destroyThis(BCE);
- else if(UnaryConstantExpr* UCE = dyn_cast<UnaryConstantExpr>(this))
- UnaryConstantExpr::destroyThis(UCE);
- else if(CompareConstantExpr* CCE = dyn_cast<CompareConstantExpr>(this))
- CompareConstantExpr::destroyThis(CCE);
- else
- assert(0 && "Unknown ConstantExpr-inherited class in ~Value.");
- }
- break;
- case ConstantAggregateZeroVal:
- ConstantAggregateZero::destroyThis(cast<ConstantAggregateZero>(this));
- break;
- case ConstantIntVal:
- ConstantInt::destroyThis(cast<ConstantInt>(this));
- break;
- case ConstantFPVal:
- ConstantFP::destroyThis(cast<ConstantFP>(this));
- break;
- case ConstantArrayVal:
- ConstantArray::destroyThis(cast<ConstantArray>(this));
- break;
- case ConstantStructVal:
- ConstantStruct::destroyThis(cast<ConstantStruct>(this));
- break;
- case ConstantVectorVal:
- ConstantVector::destroyThis(cast<ConstantVector>(this));
- break;
- case ConstantPointerNullVal:
- ConstantPointerNull::destroyThis(cast<ConstantPointerNull>(this));
- break;
- case InlineAsmVal:
- InlineAsm::destroyThis(cast<InlineAsm>(this));
- break;
-
- default:
- if (BinaryOperator *BO = dyn_cast<BinaryOperator>(this))
- BinaryOperator::destroyThis(BO);
- else if (CallInst *CI = dyn_cast<CallInst>(this))
- CallInst::destroyThis(CI);
- else if (CmpInst *CI = dyn_cast<CmpInst>(this))
- {
- if (FCmpInst *FCI = dyn_cast<FCmpInst>(CI))
- FCmpInst::destroyThis(FCI);
- else if (ICmpInst *ICI = dyn_cast<ICmpInst>(CI))
- ICmpInst::destroyThis(ICI);
- else
- assert(0 && "Unknown CmpInst-inherited class in ~Value.");
- }
- else if (ExtractElementInst *EEI = dyn_cast<ExtractElementInst>(this))
- ExtractElementInst::destroyThis(EEI);
- else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(this))
- GetElementPtrInst::destroyThis(GEP);
- else if (InsertElementInst* IE = dyn_cast<InsertElementInst>(this))
- InsertElementInst::destroyThis(IE);
- else if (PHINode *PN = dyn_cast<PHINode>(this))
- PHINode::destroyThis(PN);
- else if (SelectInst *SI = dyn_cast<SelectInst>(this))
- SelectInst::destroyThis(SI);
- else if (ShuffleVectorInst *SVI = dyn_cast<ShuffleVectorInst>(this))
- ShuffleVectorInst::destroyThis(SVI);
- else if (StoreInst *SI = dyn_cast<StoreInst>(this))
- StoreInst::destroyThis(SI);
- else if (TerminatorInst *TI = dyn_cast<TerminatorInst>(this))
- {
- if (BranchInst* BI = dyn_cast<BranchInst>(TI))
- BranchInst::destroyThis(BI);
- else if (InvokeInst* II = dyn_cast<InvokeInst>(TI))
- InvokeInst::destroyThis(II);
- else if (ReturnInst* RI = dyn_cast<ReturnInst>(TI))
- ReturnInst::destroyThis(RI);
- else if (SwitchInst *SI = dyn_cast<SwitchInst>(TI))
- SwitchInst::destroyThis(SI);
- else if (UnreachableInst *UI = dyn_cast<UnreachableInst>(TI))
- UnreachableInst::destroyThis(UI);
- else if (UnwindInst *UI = dyn_cast<UnwindInst>(TI))
- UnwindInst::destroyThis(UI);
- else
- assert(0 && "Unknown TerminatorInst-inherited class in ~Value.");
- } else if(UnaryInstruction* UI = dyn_cast<UnaryInstruction>(this)) {
- if(AllocationInst* AI = dyn_cast<AllocationInst>(UI)) {
- if(AllocaInst* AI = dyn_cast<AllocaInst>(UI))
- AllocaInst::destroyThis(AI);
- else if(MallocInst* MI = dyn_cast<MallocInst>(UI))
- MallocInst::destroyThis(MI);
- else
- assert(0 && "Unknown AllocationInst-inherited class in ~Value.");
- } else if(CastInst* CI = dyn_cast<CastInst>(this)) {
- if(BitCastInst* BCI = dyn_cast<BitCastInst>(CI))
- BitCastInst::destroyThis(BCI);
- else if(FPExtInst* FPEI = dyn_cast<FPExtInst>(CI))
- FPExtInst::destroyThis(FPEI);
- else if(FPToSIInst* FPSII = dyn_cast<FPToSIInst>(CI))
- FPToSIInst::destroyThis(FPSII);
- else if(FPToUIInst* FPUII = dyn_cast<FPToUIInst>(CI))
- FPToUIInst::destroyThis(FPUII);
- else if(FPTruncInst* FPTI = dyn_cast<FPTruncInst>(CI))
- FPTruncInst::destroyThis(FPTI);
- else if(IntToPtrInst* I2PI = dyn_cast<IntToPtrInst>(CI))
- IntToPtrInst::destroyThis(I2PI);
- else if(PtrToIntInst* P2II = dyn_cast<PtrToIntInst>(CI))
- PtrToIntInst::destroyThis(P2II);
- else if(SExtInst* SEI = dyn_cast<SExtInst>(CI))
- SExtInst::destroyThis(SEI);
- else if(SIToFPInst* SIFPI = dyn_cast<SIToFPInst>(CI))
- SIToFPInst::destroyThis(SIFPI);
- else if(TruncInst* TI = dyn_cast<TruncInst>(CI))
- TruncInst::destroyThis(TI);
- else if(UIToFPInst* UIFPI = dyn_cast<UIToFPInst>(CI))
- UIToFPInst::destroyThis(UIFPI);
- else if(ZExtInst* ZEI = dyn_cast<ZExtInst>(CI))
- ZExtInst::destroyThis(ZEI);
- else
- assert(0 && "Unknown CastInst-inherited class in ~Value.");
- }
- else if(FreeInst* FI = dyn_cast<FreeInst>(this))
- FreeInst::destroyThis(FI);
- else if(LoadInst* LI = dyn_cast<LoadInst>(this))
- LoadInst::destroyThis(LI);
- else if(VAArgInst* VAI = dyn_cast<VAArgInst>(this))
- VAArgInst::destroyThis(VAI);
- else
- assert(0 && "Unknown UnaryInstruction-inherited class in ~Value.");
- }
- else if (DummyInst *DI = dyn_cast<DummyInst>(this))
- DummyInst::destroyThis(DI);
- else
- assert(0 && "Unknown Instruction-inherited class in ~Value.");
- break;
- }
-}
+Value::~Value() {
+ // Notify all ValueHandles (if present) that this value is going away.
+ if (HasValueHandle)
+ ValueHandleBase::ValueIsDeleted(this);
-void Value::destroyThis(Value*v)
-{
#ifndef NDEBUG // Only in -g mode...
// Check to make sure that there are no uses of this value that are still
// around when the value is destroyed. If there are, then we have a dangling
// still being referenced. The value in question should be printed as
// a <badref>
//
- if (!v->use_empty()) {
- DOUT << "While deleting: " << *v->Ty << " %" << v->Name << "\n";
- for (use_iterator I = v->use_begin(), E = v->use_end(); I != E; ++I)
- DOUT << "Use still stuck around after Def is destroyed:"
+ if (!use_empty()) {
+ dbgs() << "While deleting: " << *VTy << " %" << getNameStr() << "\n";
+ for (use_iterator I = use_begin(), E = use_end(); I != E; ++I)
+ dbgs() << "Use still stuck around after Def is destroyed:"
<< **I << "\n";
}
#endif
- assert(v->use_empty() && "Uses remain when a value is destroyed!");
+ assert(use_empty() && "Uses remain when a value is destroyed!");
// If this value is named, destroy the name. This should not be in a symtab
// at this point.
- if (v->Name)
- v->Name->Destroy();
-
+ if (Name)
+ Name->Destroy();
+
// There should be no uses of this object anymore, remove it.
- LeakDetector::removeGarbageObject(v);
+ LeakDetector::removeGarbageObject(this);
}
/// hasNUses - Return true if this Value has exactly N users.
///
bool Value::hasNUses(unsigned N) const {
- use_const_iterator UI = use_begin(), E = use_end();
+ const_use_iterator UI = use_begin(), E = use_end();
for (; N; --N, ++UI)
if (UI == E) return false; // Too few.
/// logically equivalent to getNumUses() >= N.
///
bool Value::hasNUsesOrMore(unsigned N) const {
- use_const_iterator UI = use_begin(), E = use_end();
+ const_use_iterator UI = use_begin(), E = use_end();
for (; N; --N, ++UI)
if (UI == E) return false; // Too few.
return true;
}
+/// isUsedInBasicBlock - Return true if this value is used in the specified
+/// basic block.
+bool Value::isUsedInBasicBlock(const BasicBlock *BB) const {
+ for (const_use_iterator I = use_begin(), E = use_end(); I != E; ++I) {
+ const Instruction *User = dyn_cast<Instruction>(*I);
+ if (User && User->getParent() == BB)
+ return true;
+ }
+ return false;
+}
+
/// getNumUses - This method computes the number of uses of this Value. This
/// is a linear time operation. Use hasOneUse or hasNUses to check for specific
if (Function *PP = P->getParent())
ST = &PP->getValueSymbolTable();
} else if (BasicBlock *BB = dyn_cast<BasicBlock>(V)) {
- if (Function *P = BB->getParent())
+ if (Function *P = BB->getParent())
ST = &P->getValueSymbolTable();
} else if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
- if (Module *P = GV->getParent())
+ if (Module *P = GV->getParent())
ST = &P->getValueSymbolTable();
} else if (Argument *A = dyn_cast<Argument>(V)) {
- if (Function *P = A->getParent())
+ if (Function *P = A->getParent())
ST = &P->getValueSymbolTable();
- } else {
+ } else if (isa<MDString>(V))
+ return true;
+ else {
assert(isa<Constant>(V) && "Unknown value type!");
return true; // no name is setable for this.
}
return false;
}
-/// getNameStart - Return a pointer to a null terminated string for this name.
-/// Note that names can have null characters within the string as well as at
-/// their end. This always returns a non-null pointer.
-const char *Value::getNameStart() const {
- if (Name == 0) return "";
- return Name->getKeyData();
+StringRef Value::getName() const {
+ // Make sure the empty string is still a C string. For historical reasons,
+ // some clients want to call .data() on the result and expect it to be null
+ // terminated.
+ if (!Name) return StringRef("", 0);
+ return Name->getKey();
}
-/// getNameLen - Return the length of the string, correctly handling nul
-/// characters embedded into them.
-unsigned Value::getNameLen() const {
- return Name ? Name->getKeyLength() : 0;
+std::string Value::getNameStr() const {
+ return getName().str();
}
+void Value::setName(const Twine &NewName) {
+ // Fast path for common IRBuilder case of setName("") when there is no name.
+ if (NewName.isTriviallyEmpty() && !hasName())
+ return;
-std::string Value::getNameStr() const {
- if (Name == 0) return "";
- return std::string(Name->getKeyData(),
- Name->getKeyData()+Name->getKeyLength());
-}
+ SmallString<256> NameData;
+ StringRef NameRef = NewName.toStringRef(NameData);
-void Value::setName(const std::string &name) {
- setName(&name[0], name.size());
-}
+ // Name isn't changing?
+ if (getName() == NameRef)
+ return;
-void Value::setName(const char *Name) {
- setName(Name, Name ? strlen(Name) : 0);
-}
+ assert(!getType()->isVoidTy() && "Cannot assign a name to void values!");
-void Value::setName(const char *NameStr, unsigned NameLen) {
- if (NameLen == 0 && !hasName()) return;
- assert(getType() != Type::VoidTy && "Cannot assign a name to void values!");
-
// Get the symbol table to update for this object.
ValueSymbolTable *ST;
if (getSymTab(this, ST))
return; // Cannot set a name on this value (e.g. constant).
if (!ST) { // No symbol table to update? Just do the change.
- if (NameLen == 0) {
+ if (NameRef.empty()) {
// Free the name for this value.
Name->Destroy();
Name = 0;
return;
}
-
- if (Name) {
- // Name isn't changing?
- if (NameLen == Name->getKeyLength() &&
- !memcmp(Name->getKeyData(), NameStr, NameLen))
- return;
+
+ if (Name)
Name->Destroy();
- }
-
+
// NOTE: Could optimize for the case the name is shrinking to not deallocate
// then reallocated.
-
+
// Create the new name.
- Name = ValueName::Create(NameStr, NameStr+NameLen);
+ Name = ValueName::Create(NameRef.begin(), NameRef.end());
Name->setValue(this);
return;
}
-
+
// NOTE: Could optimize for the case the name is shrinking to not deallocate
// then reallocated.
if (hasName()) {
- // Name isn't changing?
- if (NameLen == Name->getKeyLength() &&
- !memcmp(Name->getKeyData(), NameStr, NameLen))
- return;
-
// Remove old name.
ST->removeValueName(Name);
Name->Destroy();
Name = 0;
- if (NameLen == 0)
+ if (NameRef.empty())
return;
}
// Name is changing to something new.
- Name = ST->createValueName(NameStr, NameLen, this);
+ Name = ST->createValueName(NameRef, this);
}
/// takeName - transfer the name from V to this value, setting V's name to
-/// empty. It is an error to call V->takeName(V).
+/// empty. It is an error to call V->takeName(V).
void Value::takeName(Value *V) {
ValueSymbolTable *ST = 0;
// If this value has a name, drop it.
if (getSymTab(this, ST)) {
// We can't set a name on this value, but we need to clear V's name if
// it has one.
- if (V->hasName()) V->setName(0, 0);
+ if (V->hasName()) V->setName("");
return; // Cannot set a name on this value (e.g. constant).
}
-
+
// Remove old name.
if (ST)
ST->removeValueName(Name);
Name->Destroy();
Name = 0;
- }
-
+ }
+
// Now we know that this has no name.
-
+
// If V has no name either, we're done.
if (!V->hasName()) return;
-
+
// Get this's symtab if we didn't before.
if (!ST) {
if (getSymTab(this, ST)) {
// Clear V's name.
- V->setName(0, 0);
+ V->setName("");
return; // Cannot set a name on this value (e.g. constant).
}
}
-
+
// Get V's ST, this should always succed, because V has a name.
ValueSymbolTable *VST;
bool Failure = getSymTab(V, VST);
- assert(!Failure && "V has a name, so it should have a ST!");
-
+ assert(!Failure && "V has a name, so it should have a ST!"); (void)Failure;
+
// If these values are both in the same symtab, we can do this very fast.
// This works even if both values have no symtab yet.
if (ST == VST) {
Name->setValue(this);
return;
}
-
+
// Otherwise, things are slightly more complex. Remove V's name from VST and
// then reinsert it into ST.
-
+
if (VST)
VST->removeValueName(V->Name);
Name = V->Name;
V->Name = 0;
Name->setValue(this);
-
+
if (ST)
ST->reinsertValue(this);
}
-// uncheckedReplaceAllUsesWith - This is exactly the same as replaceAllUsesWith,
-// except that it doesn't have all of the asserts. The asserts fail because we
-// are half-way done resolving types, which causes some types to exist as two
-// different Type*'s at the same time. This is a sledgehammer to work around
-// this problem.
-//
-void Value::uncheckedReplaceAllUsesWith(Value *New) {
+void Value::replaceAllUsesWith(Value *New) {
+ assert(New && "Value::replaceAllUsesWith(<null>) is invalid!");
+ assert(New != this && "this->replaceAllUsesWith(this) is NOT valid!");
+ assert(New->getType() == getType() &&
+ "replaceAllUses of value with new value of different type!");
+
+ // Notify all ValueHandles (if present) that this value is going away.
+ if (HasValueHandle)
+ ValueHandleBase::ValueIsRAUWd(this, New);
+
while (!use_empty()) {
Use &U = *UseList;
// Must handle Constants specially, we cannot call replaceUsesOfWith on a
U.set(New);
}
+
+ if (BasicBlock *BB = dyn_cast<BasicBlock>(this))
+ BB->replaceSuccessorsPhiUsesWith(cast<BasicBlock>(New));
}
-void Value::replaceAllUsesWith(Value *New) {
- assert(New && "Value::replaceAllUsesWith(<null>) is invalid!");
- assert(New != this && "this->replaceAllUsesWith(this) is NOT valid!");
- assert(New->getType() == getType() &&
- "replaceAllUses of value with new value of different type!");
+Value *Value::stripPointerCasts() {
+ if (!getType()->isPointerTy())
+ return this;
+
+ // Even though we don't look through PHI nodes, we could be called on an
+ // instruction in an unreachable block, which may be on a cycle.
+ SmallPtrSet<Value *, 4> Visited;
+
+ Value *V = this;
+ Visited.insert(V);
+ do {
+ if (GEPOperator *GEP = dyn_cast<GEPOperator>(V)) {
+ if (!GEP->hasAllZeroIndices())
+ return V;
+ V = GEP->getPointerOperand();
+ } else if (Operator::getOpcode(V) == Instruction::BitCast) {
+ V = cast<Operator>(V)->getOperand(0);
+ } else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V)) {
+ if (GA->mayBeOverridden())
+ return V;
+ V = GA->getAliasee();
+ } else {
+ return V;
+ }
+ assert(V->getType()->isPointerTy() && "Unexpected operand type!");
+ } while (Visited.insert(V));
+
+ return V;
+}
+
+/// isDereferenceablePointer - Test if this value is always a pointer to
+/// allocated and suitably aligned memory for a simple load or store.
+bool Value::isDereferenceablePointer() const {
+ // Note that it is not safe to speculate into a malloc'd region because
+ // malloc may return null.
+ // It's also not always safe to follow a bitcast, for example:
+ // bitcast i8* (alloca i8) to i32*
+ // would result in a 4-byte load from a 1-byte alloca. Some cases could
+ // be handled using TargetData to check sizes and alignments though.
+
+ // These are obviously ok.
+ if (isa<AllocaInst>(this)) return true;
+
+ // Global variables which can't collapse to null are ok.
+ if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(this))
+ return !GV->hasExternalWeakLinkage();
+
+ // byval arguments are ok.
+ if (const Argument *A = dyn_cast<Argument>(this))
+ return A->hasByValAttr();
+
+ // For GEPs, determine if the indexing lands within the allocated object.
+ if (const GEPOperator *GEP = dyn_cast<GEPOperator>(this)) {
+ // Conservatively require that the base pointer be fully dereferenceable.
+ if (!GEP->getOperand(0)->isDereferenceablePointer())
+ return false;
+ // Check the indices.
+ gep_type_iterator GTI = gep_type_begin(GEP);
+ for (User::const_op_iterator I = GEP->op_begin()+1,
+ E = GEP->op_end(); I != E; ++I) {
+ Value *Index = *I;
+ Type *Ty = *GTI++;
+ // Struct indices can't be out of bounds.
+ if (isa<StructType>(Ty))
+ continue;
+ ConstantInt *CI = dyn_cast<ConstantInt>(Index);
+ if (!CI)
+ return false;
+ // Zero is always ok.
+ if (CI->isZero())
+ continue;
+ // Check to see that it's within the bounds of an array.
+ ArrayType *ATy = dyn_cast<ArrayType>(Ty);
+ if (!ATy)
+ return false;
+ if (CI->getValue().getActiveBits() > 64)
+ return false;
+ if (CI->getZExtValue() >= ATy->getNumElements())
+ return false;
+ }
+ // Indices check out; this is dereferenceable.
+ return true;
+ }
+
+ // If we don't know, assume the worst.
+ return false;
+}
- uncheckedReplaceAllUsesWith(New);
+/// DoPHITranslation - If this value is a PHI node with CurBB as its parent,
+/// return the value in the PHI node corresponding to PredBB. If not, return
+/// ourself. This is useful if you want to know the value something has in a
+/// predecessor block.
+Value *Value::DoPHITranslation(const BasicBlock *CurBB,
+ const BasicBlock *PredBB) {
+ PHINode *PN = dyn_cast<PHINode>(this);
+ if (PN && PN->getParent() == CurBB)
+ return PN->getIncomingValueForBlock(PredBB);
+ return this;
}
+LLVMContext &Value::getContext() const { return VTy->getContext(); }
+
//===----------------------------------------------------------------------===//
-// User Class
+// ValueHandleBase Class
//===----------------------------------------------------------------------===//
-// replaceUsesOfWith - Replaces all references to the "From" definition with
-// references to the "To" definition.
-//
-void User::replaceUsesOfWith(Value *From, Value *To) {
- if (From == To) return; // Duh what?
-
- assert(!isa<Constant>(this) || isa<GlobalValue>(this) &&
- "Cannot call User::replaceUsesofWith on a constant!");
-
- for (unsigned i = 0, E = getNumOperands(); i != E; ++i)
- if (getOperand(i) == From) { // Is This operand is pointing to oldval?
- // The side effects of this setOperand call include linking to
- // "To", adding "this" to the uses list of To, and
- // most importantly, removing "this" from the use list of "From".
- setOperand(i, To); // Fix it now...
+/// AddToExistingUseList - Add this ValueHandle to the use list for VP, where
+/// List is known to point into the existing use list.
+void ValueHandleBase::AddToExistingUseList(ValueHandleBase **List) {
+ assert(List && "Handle list is null?");
+
+ // Splice ourselves into the list.
+ Next = *List;
+ *List = this;
+ setPrevPtr(List);
+ if (Next) {
+ Next->setPrevPtr(&Next);
+ assert(VP == Next->VP && "Added to wrong list?");
+ }
+}
+
+void ValueHandleBase::AddToExistingUseListAfter(ValueHandleBase *List) {
+ assert(List && "Must insert after existing node");
+
+ Next = List->Next;
+ setPrevPtr(&List->Next);
+ List->Next = this;
+ if (Next)
+ Next->setPrevPtr(&Next);
+}
+
+/// AddToUseList - Add this ValueHandle to the use list for VP.
+void ValueHandleBase::AddToUseList() {
+ assert(VP && "Null pointer doesn't have a use list!");
+
+ LLVMContextImpl *pImpl = VP->getContext().pImpl;
+
+ if (VP->HasValueHandle) {
+ // If this value already has a ValueHandle, then it must be in the
+ // ValueHandles map already.
+ ValueHandleBase *&Entry = pImpl->ValueHandles[VP];
+ assert(Entry != 0 && "Value doesn't have any handles?");
+ AddToExistingUseList(&Entry);
+ return;
+ }
+
+ // Ok, it doesn't have any handles yet, so we must insert it into the
+ // DenseMap. However, doing this insertion could cause the DenseMap to
+ // reallocate itself, which would invalidate all of the PrevP pointers that
+ // point into the old table. Handle this by checking for reallocation and
+ // updating the stale pointers only if needed.
+ DenseMap<Value*, ValueHandleBase*> &Handles = pImpl->ValueHandles;
+ const void *OldBucketPtr = Handles.getPointerIntoBucketsArray();
+
+ ValueHandleBase *&Entry = Handles[VP];
+ assert(Entry == 0 && "Value really did already have handles?");
+ AddToExistingUseList(&Entry);
+ VP->HasValueHandle = true;
+
+ // If reallocation didn't happen or if this was the first insertion, don't
+ // walk the table.
+ if (Handles.isPointerIntoBucketsArray(OldBucketPtr) ||
+ Handles.size() == 1) {
+ return;
+ }
+
+ // Okay, reallocation did happen. Fix the Prev Pointers.
+ for (DenseMap<Value*, ValueHandleBase*>::iterator I = Handles.begin(),
+ E = Handles.end(); I != E; ++I) {
+ assert(I->second && I->first == I->second->VP && "List invariant broken!");
+ I->second->setPrevPtr(&I->second);
+ }
+}
+
+/// RemoveFromUseList - Remove this ValueHandle from its current use list.
+void ValueHandleBase::RemoveFromUseList() {
+ assert(VP && VP->HasValueHandle && "Pointer doesn't have a use list!");
+
+ // Unlink this from its use list.
+ ValueHandleBase **PrevPtr = getPrevPtr();
+ assert(*PrevPtr == this && "List invariant broken");
+
+ *PrevPtr = Next;
+ if (Next) {
+ assert(Next->getPrevPtr() == &Next && "List invariant broken");
+ Next->setPrevPtr(PrevPtr);
+ return;
+ }
+
+ // If the Next pointer was null, then it is possible that this was the last
+ // ValueHandle watching VP. If so, delete its entry from the ValueHandles
+ // map.
+ LLVMContextImpl *pImpl = VP->getContext().pImpl;
+ DenseMap<Value*, ValueHandleBase*> &Handles = pImpl->ValueHandles;
+ if (Handles.isPointerIntoBucketsArray(PrevPtr)) {
+ Handles.erase(VP);
+ VP->HasValueHandle = false;
+ }
+}
+
+
+void ValueHandleBase::ValueIsDeleted(Value *V) {
+ assert(V->HasValueHandle && "Should only be called if ValueHandles present");
+
+ // Get the linked list base, which is guaranteed to exist since the
+ // HasValueHandle flag is set.
+ LLVMContextImpl *pImpl = V->getContext().pImpl;
+ ValueHandleBase *Entry = pImpl->ValueHandles[V];
+ assert(Entry && "Value bit set but no entries exist");
+
+ // We use a local ValueHandleBase as an iterator so that ValueHandles can add
+ // and remove themselves from the list without breaking our iteration. This
+ // is not really an AssertingVH; we just have to give ValueHandleBase a kind.
+ // Note that we deliberately do not the support the case when dropping a value
+ // handle results in a new value handle being permanently added to the list
+ // (as might occur in theory for CallbackVH's): the new value handle will not
+ // be processed and the checking code will mete out righteous punishment if
+ // the handle is still present once we have finished processing all the other
+ // value handles (it is fine to momentarily add then remove a value handle).
+ for (ValueHandleBase Iterator(Assert, *Entry); Entry; Entry = Iterator.Next) {
+ Iterator.RemoveFromUseList();
+ Iterator.AddToExistingUseListAfter(Entry);
+ assert(Entry->Next == &Iterator && "Loop invariant broken.");
+
+ switch (Entry->getKind()) {
+ case Assert:
+ break;
+ case Tracking:
+ // Mark that this value has been deleted by setting it to an invalid Value
+ // pointer.
+ Entry->operator=(DenseMapInfo<Value *>::getTombstoneKey());
+ break;
+ case Weak:
+ // Weak just goes to null, which will unlink it from the list.
+ Entry->operator=(0);
+ break;
+ case Callback:
+ // Forward to the subclass's implementation.
+ static_cast<CallbackVH*>(Entry)->deleted();
+ break;
}
+ }
+
+ // All callbacks, weak references, and assertingVHs should be dropped by now.
+ if (V->HasValueHandle) {
+#ifndef NDEBUG // Only in +Asserts mode...
+ dbgs() << "While deleting: " << *V->getType() << " %" << V->getNameStr()
+ << "\n";
+ if (pImpl->ValueHandles[V]->getKind() == Assert)
+ llvm_unreachable("An asserting value handle still pointed to this"
+ " value!");
+
+#endif
+ llvm_unreachable("All references to V were not removed?");
+ }
+}
+
+
+void ValueHandleBase::ValueIsRAUWd(Value *Old, Value *New) {
+ assert(Old->HasValueHandle &&"Should only be called if ValueHandles present");
+ assert(Old != New && "Changing value into itself!");
+
+ // Get the linked list base, which is guaranteed to exist since the
+ // HasValueHandle flag is set.
+ LLVMContextImpl *pImpl = Old->getContext().pImpl;
+ ValueHandleBase *Entry = pImpl->ValueHandles[Old];
+
+ assert(Entry && "Value bit set but no entries exist");
+
+ // We use a local ValueHandleBase as an iterator so that
+ // ValueHandles can add and remove themselves from the list without
+ // breaking our iteration. This is not really an AssertingVH; we
+ // just have to give ValueHandleBase some kind.
+ for (ValueHandleBase Iterator(Assert, *Entry); Entry; Entry = Iterator.Next) {
+ Iterator.RemoveFromUseList();
+ Iterator.AddToExistingUseListAfter(Entry);
+ assert(Entry->Next == &Iterator && "Loop invariant broken.");
+
+ switch (Entry->getKind()) {
+ case Assert:
+ // Asserting handle does not follow RAUW implicitly.
+ break;
+ case Tracking:
+ // Tracking goes to new value like a WeakVH. Note that this may make it
+ // something incompatible with its templated type. We don't want to have a
+ // virtual (or inline) interface to handle this though, so instead we make
+ // the TrackingVH accessors guarantee that a client never sees this value.
+
+ // FALLTHROUGH
+ case Weak:
+ // Weak goes to the new value, which will unlink it from Old's list.
+ Entry->operator=(New);
+ break;
+ case Callback:
+ // Forward to the subclass's implementation.
+ static_cast<CallbackVH*>(Entry)->allUsesReplacedWith(New);
+ break;
+ }
+ }
+
+#ifndef NDEBUG
+ // If any new tracking or weak value handles were added while processing the
+ // list, then complain about it now.
+ if (Old->HasValueHandle)
+ for (Entry = pImpl->ValueHandles[Old]; Entry; Entry = Entry->Next)
+ switch (Entry->getKind()) {
+ case Tracking:
+ case Weak:
+ dbgs() << "After RAUW from " << *Old->getType() << " %"
+ << Old->getNameStr() << " to " << *New->getType() << " %"
+ << New->getNameStr() << "\n";
+ llvm_unreachable("A tracking or weak value handle still pointed to the"
+ " old value!\n");
+ default:
+ break;
+ }
+#endif
}
+/// ~CallbackVH. Empty, but defined here to avoid emitting the vtable
+/// more than once.
+CallbackVH::~CallbackVH() {}
projects / oota-llvm.git / blobdiff