#include "LLVMContextImpl.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallString.h"
+#include "llvm/IR/CallSite.h"
#include "llvm/IR/Constant.h"
#include "llvm/IR/Constants.h"
+#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/GetElementPtrTypeIterator.h"
#include "llvm/IR/InstrTypes.h"
#include "llvm/IR/Instructions.h"
+#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Operator.h"
+#include "llvm/IR/Statepoint.h"
+#include "llvm/IR/ValueHandle.h"
#include "llvm/IR/ValueSymbolTable.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
-#include "llvm/Support/GetElementPtrTypeIterator.h"
-#include "llvm/Support/LeakDetector.h"
#include "llvm/Support/ManagedStatic.h"
-#include "llvm/Support/ValueHandle.h"
+#include "llvm/Support/raw_ostream.h"
#include <algorithm>
using namespace llvm;
//===----------------------------------------------------------------------===//
// Value Class
//===----------------------------------------------------------------------===//
+const unsigned Value::NumUserOperandsBits;
static inline Type *checkType(Type *Ty) {
assert(Ty && "Value defined with a null type: Error!");
- return const_cast<Type*>(Ty);
+ return Ty;
}
Value::Value(Type *ty, unsigned scid)
- : SubclassID(scid), HasValueHandle(0),
- SubclassOptionalData(0), SubclassData(0), VTy((Type*)checkType(ty)),
- UseList(0), Name(0) {
+ : VTy(checkType(ty)), UseList(nullptr), SubclassID(scid),
+ HasValueHandle(0), SubclassOptionalData(0), SubclassData(0),
+ NumUserOperands(0), IsUsedByMD(false), HasName(false) {
// FIXME: Why isn't this in the subclass gunk??
// Note, we cannot call isa<CallInst> before the CallInst has been
// constructed.
// Notify all ValueHandles (if present) that this value is going away.
if (HasValueHandle)
ValueHandleBase::ValueIsDeleted(this);
+ if (isUsedByMetadata())
+ ValueAsMetadata::handleDeletion(this);
#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
- // reference and something is wrong. This code is here to print out what is
- // still being referenced. The value in question should be printed as
- // a <badref>
+ // reference and something is wrong. This code is here to print out where
+ // the value is still being referenced.
//
if (!use_empty()) {
dbgs() << "While deleting: " << *VTy << " %" << getName() << "\n";
- for (use_iterator I = use_begin(), E = use_end(); I != E; ++I)
- dbgs() << "Use still stuck around after Def is destroyed:"
- << **I << "\n";
+ for (auto *U : users())
+ dbgs() << "Use still stuck around after Def is destroyed:" << *U << "\n";
}
#endif
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 (Name && SubclassID != MDStringVal)
- Name->Destroy();
+ destroyValueName();
+}
- // There should be no uses of this object anymore, remove it.
- LeakDetector::removeGarbageObject(this);
+void Value::destroyValueName() {
+ ValueName *Name = getValueName();
+ if (Name)
+ Name->Destroy();
+ setValueName(nullptr);
}
-/// hasNUses - Return true if this Value has exactly N users.
-///
bool Value::hasNUses(unsigned N) const {
const_use_iterator UI = use_begin(), E = use_end();
return UI == E;
}
-/// hasNUsesOrMore - Return true if this value has N users or more. This is
-/// logically equivalent to getNumUses() >= N.
-///
bool Value::hasNUsesOrMore(unsigned N) const {
const_use_iterator UI = use_begin(), E = use_end();
return true;
}
-/// isUsedInBasicBlock - Return true if this value is used in the specified
-/// basic block.
bool Value::isUsedInBasicBlock(const BasicBlock *BB) const {
- // Start by scanning over the instructions looking for a use before we start
- // the expensive use iteration.
- unsigned MaxBlockSize = 3;
- for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
- if (std::find(I->op_begin(), I->op_end(), this) != I->op_end())
+ // This can be computed either by scanning the instructions in BB, or by
+ // scanning the use list of this Value. Both lists can be very long, but
+ // usually one is quite short.
+ //
+ // Scan both lists simultaneously until one is exhausted. This limits the
+ // search to the shorter list.
+ BasicBlock::const_iterator BI = BB->begin(), BE = BB->end();
+ const_user_iterator UI = user_begin(), UE = user_end();
+ for (; BI != BE && UI != UE; ++BI, ++UI) {
+ // Scan basic block: Check if this Value is used by the instruction at BI.
+ if (std::find(BI->op_begin(), BI->op_end(), this) != BI->op_end())
return true;
- if (--MaxBlockSize == 0) // If the block is larger fall back to use_iterator
- break;
- }
-
- if (MaxBlockSize != 0) // We scanned the entire block and found no use.
- return false;
-
- for (const_use_iterator I = use_begin(), E = use_end(); I != E; ++I) {
- const Instruction *User = dyn_cast<Instruction>(*I);
+ // Scan use list: Check if the use at UI is in BB.
+ const Instruction *User = dyn_cast<Instruction>(*UI);
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
-/// values.
unsigned Value::getNumUses() const {
return (unsigned)std::distance(use_begin(), use_end());
}
static bool getSymTab(Value *V, ValueSymbolTable *&ST) {
- ST = 0;
+ ST = nullptr;
if (Instruction *I = dyn_cast<Instruction>(V)) {
if (BasicBlock *P = I->getParent())
if (Function *PP = P->getParent())
} else if (Argument *A = dyn_cast<Argument>(V)) {
if (Function *P = A->getParent())
ST = &P->getValueSymbolTable();
- } else if (isa<MDString>(V))
- return true;
- else {
+ } else {
assert(isa<Constant>(V) && "Unknown value type!");
return true; // no name is setable for this.
}
return false;
}
+ValueName *Value::getValueName() const {
+ if (!HasName) return nullptr;
+
+ LLVMContext &Ctx = getContext();
+ auto I = Ctx.pImpl->ValueNames.find(this);
+ assert(I != Ctx.pImpl->ValueNames.end() &&
+ "No name entry found!");
+
+ return I->second;
+}
+
+void Value::setValueName(ValueName *VN) {
+ LLVMContext &Ctx = getContext();
+
+ assert(HasName == Ctx.pImpl->ValueNames.count(this) &&
+ "HasName bit out of sync!");
+
+ if (!VN) {
+ if (HasName)
+ Ctx.pImpl->ValueNames.erase(this);
+ HasName = false;
+ return;
+ }
+
+ HasName = true;
+ Ctx.pImpl->ValueNames[this] = VN;
+}
+
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();
+ if (!hasName())
+ return StringRef("", 0);
+ return getValueName()->getKey();
}
-void Value::setName(const Twine &NewName) {
- assert(SubclassID != MDStringVal &&
- "Cannot set the name of MDString with this method!");
-
+void Value::setNameImpl(const Twine &NewName) {
// Fast path for common IRBuilder case of setName("") when there is no name.
if (NewName.isTriviallyEmpty() && !hasName())
return;
SmallString<256> NameData;
StringRef NameRef = NewName.toStringRef(NameData);
+ assert(NameRef.find_first_of(0) == StringRef::npos &&
+ "Null bytes are not allowed in names");
// Name isn't changing?
if (getName() == NameRef)
if (getSymTab(this, ST))
return; // Cannot set a name on this value (e.g. constant).
- if (Function *F = dyn_cast<Function>(this))
- getContext().pImpl->IntrinsicIDCache.erase(F);
-
if (!ST) { // No symbol table to update? Just do the change.
if (NameRef.empty()) {
// Free the name for this value.
- Name->Destroy();
- Name = 0;
+ destroyValueName();
return;
}
- if (Name)
- Name->Destroy();
-
// NOTE: Could optimize for the case the name is shrinking to not deallocate
// then reallocated.
+ destroyValueName();
// Create the new name.
- Name = ValueName::Create(NameRef.begin(), NameRef.end());
- Name->setValue(this);
+ setValueName(ValueName::Create(NameRef));
+ getValueName()->setValue(this);
return;
}
// then reallocated.
if (hasName()) {
// Remove old name.
- ST->removeValueName(Name);
- Name->Destroy();
- Name = 0;
+ ST->removeValueName(getValueName());
+ destroyValueName();
if (NameRef.empty())
return;
}
// Name is changing to something new.
- Name = ST->createValueName(NameRef, this);
+ setValueName(ST->createValueName(NameRef, this));
}
+void Value::setName(const Twine &NewName) {
+ setNameImpl(NewName);
+ if (Function *F = dyn_cast<Function>(this))
+ F->recalculateIntrinsicID();
+}
-/// takeName - transfer the name from V to this value, setting V's name to
-/// empty. It is an error to call V->takeName(V).
void Value::takeName(Value *V) {
- assert(SubclassID != MDStringVal && "Cannot take the name of an MDString!");
-
- ValueSymbolTable *ST = 0;
+ ValueSymbolTable *ST = nullptr;
// If this value has a name, drop it.
if (hasName()) {
// Get the symtab this is in.
// Remove old name.
if (ST)
- ST->removeValueName(Name);
- Name->Destroy();
- Name = 0;
+ ST->removeValueName(getValueName());
+ destroyValueName();
}
// Now we know that this has no name.
// This works even if both values have no symtab yet.
if (ST == VST) {
// Take the name!
- Name = V->Name;
- V->Name = 0;
- Name->setValue(this);
+ setValueName(V->getValueName());
+ V->setValueName(nullptr);
+ getValueName()->setValue(this);
return;
}
// then reinsert it into ST.
if (VST)
- VST->removeValueName(V->Name);
- Name = V->Name;
- V->Name = 0;
- Name->setValue(this);
+ VST->removeValueName(V->getValueName());
+ setValueName(V->getValueName());
+ V->setValueName(nullptr);
+ getValueName()->setValue(this);
if (ST)
ST->reinsertValue(this);
}
+#ifndef NDEBUG
+static bool contains(SmallPtrSetImpl<ConstantExpr *> &Cache, ConstantExpr *Expr,
+ Constant *C) {
+ if (!Cache.insert(Expr).second)
+ return false;
+
+ for (auto &O : Expr->operands()) {
+ if (O == C)
+ return true;
+ auto *CE = dyn_cast<ConstantExpr>(O);
+ if (!CE)
+ continue;
+ if (contains(Cache, CE, C))
+ return true;
+ }
+ return false;
+}
+
+static bool contains(Value *Expr, Value *V) {
+ if (Expr == V)
+ return true;
+
+ auto *C = dyn_cast<Constant>(V);
+ if (!C)
+ return false;
+
+ auto *CE = dyn_cast<ConstantExpr>(Expr);
+ if (!CE)
+ return false;
+
+ SmallPtrSet<ConstantExpr *, 4> Cache;
+ return contains(Cache, CE, C);
+}
+#endif
void Value::replaceAllUsesWith(Value *New) {
assert(New && "Value::replaceAllUsesWith(<null>) is invalid!");
- assert(New != this && "this->replaceAllUsesWith(this) is NOT valid!");
+ assert(!contains(New, this) &&
+ "this->replaceAllUsesWith(expr(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 (isUsedByMetadata())
+ ValueAsMetadata::handleRAUW(this, New);
while (!use_empty()) {
Use &U = *UseList;
// Must handle Constants specially, we cannot call replaceUsesOfWith on a
// constant because they are uniqued.
- if (Constant *C = dyn_cast<Constant>(U.getUser())) {
+ if (auto *C = dyn_cast<Constant>(U.getUser())) {
if (!isa<GlobalValue>(C)) {
C->replaceUsesOfWithOnConstant(this, New, &U);
continue;
BB->replaceSuccessorsPhiUsesWith(cast<BasicBlock>(New));
}
+// Like replaceAllUsesWith except it does not handle constants or basic blocks.
+// This routine leaves uses within BB.
+void Value::replaceUsesOutsideBlock(Value *New, BasicBlock *BB) {
+ assert(New && "Value::replaceUsesOutsideBlock(<null>, BB) is invalid!");
+ assert(!contains(New, this) &&
+ "this->replaceUsesOutsideBlock(expr(this), BB) is NOT valid!");
+ assert(New->getType() == getType() &&
+ "replaceUses of value with new value of different type!");
+ assert(BB && "Basic block that may contain a use of 'New' must be defined\n");
+
+ use_iterator UI = use_begin(), E = use_end();
+ for (; UI != E;) {
+ Use &U = *UI;
+ ++UI;
+ auto *Usr = dyn_cast<Instruction>(U.getUser());
+ if (Usr && Usr->getParent() == BB)
+ continue;
+ U.set(New);
+ }
+ return;
+}
+
namespace {
// Various metrics for how much to strip off of pointers.
enum PointerStripKind {
break;
}
V = GEP->getPointerOperand();
- } else if (Operator::getOpcode(V) == Instruction::BitCast) {
+ } else if (Operator::getOpcode(V) == Instruction::BitCast ||
+ Operator::getOpcode(V) == Instruction::AddrSpaceCast) {
V = cast<Operator>(V)->getOperand(0);
} else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V)) {
if (StripKind == PSK_ZeroIndices || GA->mayBeOverridden())
return V;
}
assert(V->getType()->isPointerTy() && "Unexpected operand type!");
- } while (Visited.insert(V));
+ } while (Visited.insert(V).second);
return V;
}
return stripPointerCastsAndOffsets<PSK_InBoundsConstantIndices>(this);
}
-Value *Value::stripInBoundsOffsets() {
- return stripPointerCastsAndOffsets<PSK_InBounds>(this);
-}
+Value *Value::stripAndAccumulateInBoundsConstantOffsets(const DataLayout &DL,
+ APInt &Offset) {
+ if (!getType()->isPointerTy())
+ return this;
-/// isDereferenceablePointer - Test if this value is always a pointer to
-/// allocated and suitably aligned memory for a simple load or store.
-static bool isDereferenceablePointer(const Value *V,
- SmallPtrSet<const Value *, 32> &Visited) {
- // 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 DataLayout to check sizes and alignments though.
-
- // These are obviously ok.
- if (isa<AllocaInst>(V)) return true;
-
- // Global variables which can't collapse to null are ok.
- if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(V))
- return !GV->hasExternalWeakLinkage();
-
- // byval arguments are ok.
- if (const Argument *A = dyn_cast<Argument>(V))
- return A->hasByValAttr();
-
- // For GEPs, determine if the indexing lands within the allocated object.
- if (const GEPOperator *GEP = dyn_cast<GEPOperator>(V)) {
- // Conservatively require that the base pointer be fully dereferenceable.
- if (!Visited.insert(GEP->getOperand(0)))
- return false;
- if (!isDereferenceablePointer(GEP->getOperand(0), Visited))
- 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;
+ assert(Offset.getBitWidth() == DL.getPointerSizeInBits(cast<PointerType>(
+ getType())->getAddressSpace()) &&
+ "The offset must have exactly as many bits as our pointer.");
+
+ // 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;
+ Visited.insert(this);
+ Value *V = this;
+ do {
+ if (GEPOperator *GEP = dyn_cast<GEPOperator>(V)) {
+ if (!GEP->isInBounds())
+ return V;
+ APInt GEPOffset(Offset);
+ if (!GEP->accumulateConstantOffset(DL, GEPOffset))
+ return V;
+ Offset = GEPOffset;
+ V = GEP->getPointerOperand();
+ } else if (Operator::getOpcode(V) == Instruction::BitCast ||
+ Operator::getOpcode(V) == Instruction::AddrSpaceCast) {
+ V = cast<Operator>(V)->getOperand(0);
+ } else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V)) {
+ V = GA->getAliasee();
+ } else {
+ return V;
}
- // Indices check out; this is dereferenceable.
- return true;
- }
+ assert(V->getType()->isPointerTy() && "Unexpected operand type!");
+ } while (Visited.insert(V).second);
- // If we don't know, assume the worst.
- return false;
+ 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 {
- SmallPtrSet<const Value *, 32> Visited;
- return ::isDereferenceablePointer(this, Visited);
+Value *Value::stripInBoundsOffsets() {
+ return stripPointerCastsAndOffsets<PSK_InBounds>(this);
}
-/// 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);
LLVMContext &Value::getContext() const { return VTy->getContext(); }
+void Value::reverseUseList() {
+ if (!UseList || !UseList->Next)
+ // No need to reverse 0 or 1 uses.
+ return;
+
+ Use *Head = UseList;
+ Use *Current = UseList->Next;
+ Head->Next = nullptr;
+ while (Current) {
+ Use *Next = Current->Next;
+ Current->Next = Head;
+ Head->setPrev(&Current->Next);
+ Head = Current;
+ Current = Next;
+ }
+ UseList = Head;
+ Head->setPrev(&UseList);
+}
+
//===----------------------------------------------------------------------===//
// ValueHandleBase Class
//===----------------------------------------------------------------------===//
-/// 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?");
setPrevPtr(List);
if (Next) {
Next->setPrevPtr(&Next);
- assert(VP.getPointer() == Next->VP.getPointer() && "Added to wrong list?");
+ assert(V == Next->V && "Added to wrong list?");
}
}
Next->setPrevPtr(&Next);
}
-/// AddToUseList - Add this ValueHandle to the use list for VP.
void ValueHandleBase::AddToUseList() {
- assert(VP.getPointer() && "Null pointer doesn't have a use list!");
+ assert(V && "Null pointer doesn't have a use list!");
- LLVMContextImpl *pImpl = VP.getPointer()->getContext().pImpl;
+ LLVMContextImpl *pImpl = V->getContext().pImpl;
- if (VP.getPointer()->HasValueHandle) {
+ if (V->HasValueHandle) {
// If this value already has a ValueHandle, then it must be in the
// ValueHandles map already.
- ValueHandleBase *&Entry = pImpl->ValueHandles[VP.getPointer()];
- assert(Entry != 0 && "Value doesn't have any handles?");
+ ValueHandleBase *&Entry = pImpl->ValueHandles[V];
+ assert(Entry && "Value doesn't have any handles?");
AddToExistingUseList(&Entry);
return;
}
DenseMap<Value*, ValueHandleBase*> &Handles = pImpl->ValueHandles;
const void *OldBucketPtr = Handles.getPointerIntoBucketsArray();
- ValueHandleBase *&Entry = Handles[VP.getPointer()];
- assert(Entry == 0 && "Value really did already have handles?");
+ ValueHandleBase *&Entry = Handles[V];
+ assert(!Entry && "Value really did already have handles?");
AddToExistingUseList(&Entry);
- VP.getPointer()->HasValueHandle = true;
+ V->HasValueHandle = true;
// If reallocation didn't happen or if this was the first insertion, don't
// walk the table.
// 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.getPointer() &&
+ assert(I->second && I->first == I->second->V &&
"List invariant broken!");
I->second->setPrevPtr(&I->second);
}
}
-/// RemoveFromUseList - Remove this ValueHandle from its current use list.
void ValueHandleBase::RemoveFromUseList() {
- assert(VP.getPointer() && VP.getPointer()->HasValueHandle &&
+ assert(V && V->HasValueHandle &&
"Pointer doesn't have a use list!");
// Unlink this from its use list.
// 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.getPointer()->getContext().pImpl;
+ LLVMContextImpl *pImpl = V->getContext().pImpl;
DenseMap<Value*, ValueHandleBase*> &Handles = pImpl->ValueHandles;
if (Handles.isPointerIntoBucketsArray(PrevPtr)) {
- Handles.erase(VP.getPointer());
- VP.getPointer()->HasValueHandle = false;
+ Handles.erase(V);
+ V->HasValueHandle = false;
}
}
break;
case Weak:
// Weak just goes to null, which will unlink it from the list.
- Entry->operator=(0);
+ Entry->operator=(nullptr);
break;
case Callback:
// Forward to the subclass's implementation.
void ValueHandleBase::ValueIsRAUWd(Value *Old, Value *New) {
assert(Old->HasValueHandle &&"Should only be called if ValueHandles present");
assert(Old != New && "Changing value into itself!");
+ assert(Old->getType() == New->getType() &&
+ "replaceAllUses of value with new value of different type!");
// Get the linked list base, which is guaranteed to exist since the
// HasValueHandle flag is set.
#endif
}
-// Default implementation for CallbackVH.
-void CallbackVH::allUsesReplacedWith(Value *) {}
-
-void CallbackVH::deleted() {
- setValPtr(NULL);
-}
+// Pin the vtable to this file.
+void CallbackVH::anchor() {}