X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FVMCore%2FValue.cpp;h=2fa5f08a3e7f05b3b99f74fb1ab3f5a60531c9fa;hb=23946fcaaefaf3c1a9d1ef86a3786f622c005f1a;hp=826e8a10b5e465902541cd71de79b66dc5a96a55;hpb=c4775e4b973aaf6695dc00a3403b8b64f5257568;p=oota-llvm.git diff --git a/lib/VMCore/Value.cpp b/lib/VMCore/Value.cpp index 826e8a10b5e..2fa5f08a3e7 100644 --- a/lib/VMCore/Value.cpp +++ b/lib/VMCore/Value.cpp @@ -19,10 +19,10 @@ #include "llvm/Instructions.h" #include "llvm/Operator.h" #include "llvm/Module.h" -#include "llvm/Metadata.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/Support/ManagedStatic.h" @@ -35,33 +35,25 @@ 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(Ty); } -Value::Value(const Type *ty, unsigned scid) - : SubclassID(scid), HasValueHandle(0), HasMetadata(0), - SubclassOptionalData(0), SubclassData(0), VTy(checkType(ty)), +Value::Value(Type *ty, unsigned scid) + : SubclassID(scid), HasValueHandle(0), + SubclassOptionalData(0), SubclassData(0), VTy((Type*)checkType(ty)), UseList(0), Name(0) { + // FIXME: Why isn't this in the subclass gunk?? if (isa(this) || isa(this)) - assert((VTy->isFirstClassType() || - VTy == Type::getVoidTy(ty->getContext()) || - isa(ty) || VTy->getTypeID() == Type::StructTyID) && - "invalid CallInst type!"); + assert((VTy->isFirstClassType() || VTy->isVoidTy() || VTy->isStructTy()) && + "invalid CallInst type!"); else if (!isa(this) && !isa(this)) - assert((VTy->isFirstClassType() || - VTy == Type::getVoidTy(ty->getContext()) || - isa(ty)) && + assert((VTy->isFirstClassType() || VTy->isVoidTy()) && "Cannot create non-first-class values except for constants!"); } Value::~Value() { - if (HasMetadata) { - LLVMContext &Context = getContext(); - Context.pImpl->TheMetadata.ValueIsDeleted(this); - } - // Notify all ValueHandles (if present) that this value is going away. if (HasValueHandle) ValueHandleBase::ValueIsDeleted(this); @@ -74,9 +66,9 @@ Value::~Value() { // a // if (!use_empty()) { - errs() << "While deleting: " << *VTy << " %" << getNameStr() << "\n"; + dbgs() << "While deleting: " << *VTy << " %" << getNameStr() << "\n"; for (use_iterator I = use_begin(), E = use_end(); I != E; ++I) - errs() << "Use still stuck around after Def is destroyed:" + dbgs() << "Use still stuck around after Def is destroyed:" << **I << "\n"; } #endif @@ -94,7 +86,7 @@ Value::~Value() { /// 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. @@ -105,7 +97,7 @@ bool Value::hasNUses(unsigned N) const { /// 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. @@ -116,7 +108,7 @@ bool Value::hasNUsesOrMore(unsigned N) const { /// isUsedInBasicBlock - Return true if this value is used in the specified /// basic block. bool Value::isUsedInBasicBlock(const BasicBlock *BB) const { - for (use_const_iterator I = use_begin(), E = use_end(); I != E; ++I) { + for (const_use_iterator I = use_begin(), E = use_end(); I != E; ++I) { const Instruction *User = dyn_cast(*I); if (User && User->getParent() == BB) return true; @@ -147,10 +139,6 @@ static bool getSymTab(Value *V, ValueSymbolTable *&ST) { } else if (Argument *A = dyn_cast(V)) { if (Function *P = A->getParent()) ST = &P->getValueSymbolTable(); - } else if (NamedMDNode *N = dyn_cast(V)) { - if (Module *P = N->getParent()) { - ST = &P->getValueSymbolTable(); - } } else if (isa(V)) return true; else { @@ -178,17 +166,13 @@ void Value::setName(const Twine &NewName) { return; SmallString<256> NameData; - NewName.toVector(NameData); - - const char *NameStr = NameData.data(); - unsigned NameLen = NameData.size(); + StringRef NameRef = NewName.toStringRef(NameData); // Name isn't changing? - if (getName() == StringRef(NameStr, NameLen)) + if (getName() == NameRef) return; - assert(getType() != Type::getVoidTy(getContext()) && - "Cannot assign a name to void values!"); + assert(!getType()->isVoidTy() && "Cannot assign a name to void values!"); // Get the symbol table to update for this object. ValueSymbolTable *ST; @@ -196,7 +180,7 @@ void Value::setName(const Twine &NewName) { 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; @@ -210,7 +194,7 @@ void Value::setName(const Twine &NewName) { // then reallocated. // Create the new name. - Name = ValueName::Create(NameStr, NameStr+NameLen); + Name = ValueName::Create(NameRef.begin(), NameRef.end()); Name->setValue(this); return; } @@ -223,12 +207,12 @@ void Value::setName(const Twine &NewName) { Name->Destroy(); Name = 0; - if (NameLen == 0) + if (NameRef.empty()) return; } // Name is changing to something new. - Name = ST->createValueName(StringRef(NameStr, NameLen), this); + Name = ST->createValueName(NameRef, this); } @@ -270,7 +254,7 @@ void Value::takeName(Value *V) { // 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!"); Failure=Failure; + 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. @@ -296,21 +280,16 @@ void Value::takeName(Value *V) { } -// 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() 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); - if (HasMetadata) { - LLVMContext &Context = getContext(); - Context.pImpl->TheMetadata.ValueIsRAUWd(this, New); - } - + while (!use_empty()) { Use &U = *UseList; // Must handle Constants specially, we cannot call replaceUsesOfWith on a @@ -321,24 +300,24 @@ void Value::uncheckedReplaceAllUsesWith(Value *New) { continue; } } - + U.set(New); } -} - -void Value::replaceAllUsesWith(Value *New) { - assert(New && "Value::replaceAllUsesWith() is invalid!"); - assert(New != this && "this->replaceAllUsesWith(this) is NOT valid!"); - assert(New->getType() == getType() && - "replaceAllUses of value with new value of different type!"); - - uncheckedReplaceAllUsesWith(New); + + if (BasicBlock *BB = dyn_cast(this)) + BB->replaceSuccessorsPhiUsesWith(cast(New)); } Value *Value::stripPointerCasts() { - if (!isa(getType())) + 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 Visited; + Value *V = this; + Visited.insert(V); do { if (GEPOperator *GEP = dyn_cast(V)) { if (!GEP->hasAllZeroIndices()) @@ -353,30 +332,68 @@ Value *Value::stripPointerCasts() { } else { return V; } - assert(isa(V->getType()) && "Unexpected operand type!"); - } while (1); + assert(V->getType()->isPointerTy() && "Unexpected operand type!"); + } while (Visited.insert(V)); + + return V; } -Value *Value::getUnderlyingObject() { - if (!isa(getType())) - return this; - Value *V = this; - unsigned MaxLookup = 6; - do { - if (GEPOperator *GEP = dyn_cast(V)) { - V = GEP->getPointerOperand(); - } else if (Operator::getOpcode(V) == Instruction::BitCast) { - V = cast(V)->getOperand(0); - } else if (GlobalAlias *GA = dyn_cast(V)) { - if (GA->mayBeOverridden()) - return V; - V = GA->getAliasee(); - } else { - 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(this)) return true; + + // Global variables which can't collapse to null are ok. + if (const GlobalVariable *GV = dyn_cast(this)) + return !GV->hasExternalWeakLinkage(); + + // byval arguments are ok. + if (const Argument *A = dyn_cast(this)) + return A->hasByValAttr(); + + // For GEPs, determine if the indexing lands within the allocated object. + if (const GEPOperator *GEP = dyn_cast(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(Ty)) + continue; + ConstantInt *CI = dyn_cast(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(Ty); + if (!ATy) + return false; + if (CI->getValue().getActiveBits() > 64) + return false; + if (CI->getZExtValue() >= ATy->getNumElements()) + return false; } - assert(isa(V->getType()) && "Unexpected operand type!"); - } while (--MaxLookup); - return V; + // Indices check out; this is dereferenceable. + return true; + } + + // If we don't know, assume the worst. + return false; } /// DoPHITranslation - If this value is a PHI node with CurBB as its parent, @@ -501,10 +518,15 @@ void ValueHandleBase::ValueIsDeleted(Value *V) { 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 some kind. + // 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); @@ -532,7 +554,7 @@ void ValueHandleBase::ValueIsDeleted(Value *V) { // All callbacks, weak references, and assertingVHs should be dropped by now. if (V->HasValueHandle) { #ifndef NDEBUG // Only in +Asserts mode... - errs() << "While deleting: " << *V->getType() << " %" << V->getNameStr() + dbgs() << "While deleting: " << *V->getType() << " %" << V->getNameStr() << "\n"; if (pImpl->ValueHandles[V]->getKind() == Assert) llvm_unreachable("An asserting value handle still pointed to this" @@ -585,31 +607,26 @@ void ValueHandleBase::ValueIsRAUWd(Value *Old, Value *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() {} - - -//===----------------------------------------------------------------------===// -// User 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(this) || isa(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... - } -}