#include "llvm/IR/Constant.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/GetElementPtrTypeIterator.h"
#include "llvm/IR/InstrTypes.h"
#include "llvm/IR/Instructions.h"
+#include "llvm/IR/LeakDetector.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Operator.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 <algorithm>
using namespace llvm;
Value::Value(Type *ty, unsigned scid)
: SubclassID(scid), HasValueHandle(0),
SubclassOptionalData(0), SubclassData(0), VTy((Type*)checkType(ty)),
- UseList(0), Name(0) {
+ UseList(nullptr), Name(nullptr) {
// FIXME: Why isn't this in the subclass gunk??
// Note, we cannot call isa<CallInst> before the CallInst has been
// constructed.
/// 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;
}
}
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())
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 (NameRef.empty()) {
// Free the name for this value.
Name->Destroy();
- Name = 0;
+ Name = nullptr;
return;
}
// Remove old name.
ST->removeValueName(Name);
Name->Destroy();
- Name = 0;
+ Name = nullptr;
if (NameRef.empty())
return;
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.
if (ST)
ST->removeValueName(Name);
Name->Destroy();
- Name = 0;
+ Name = nullptr;
}
// Now we know that this has no name.
if (ST == VST) {
// Take the name!
Name = V->Name;
- V->Name = 0;
+ V->Name = nullptr;
Name->setValue(this);
return;
}
if (VST)
VST->removeValueName(V->Name);
Name = V->Name;
- V->Name = 0;
+ V->Name = nullptr;
Name->setValue(this);
if (ST)
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 stripPointerCastsAndOffsets<PSK_InBoundsConstantIndices>(this);
}
+Value *Value::stripAndAccumulateInBoundsConstantOffsets(const DataLayout &DL,
+ APInt &Offset) {
+ if (!getType()->isPointerTy())
+ return this;
+
+ 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) {
+ V = cast<Operator>(V)->getOperand(0);
+ } else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V)) {
+ V = GA->getAliasee();
+ } else {
+ return V;
+ }
+ assert(V->getType()->isPointerTy() && "Unexpected operand type!");
+ } while (Visited.insert(V));
+
+ return V;
+}
+
Value *Value::stripInBoundsOffsets() {
return stripPointerCastsAndOffsets<PSK_InBounds>(this);
}
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.
#endif
}
-// Default implementation for CallbackVH.
-void CallbackVH::allUsesReplacedWith(Value *) {}
-
-void CallbackVH::deleted() {
- setValPtr(NULL);
-}
+// Pin the vtable to this file.
+void CallbackVH::anchor() {}
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