uint32_t lookup(Value *V) const;
uint32_t lookup_or_add_cmp(unsigned Opcode, CmpInst::Predicate Pred,
Value *LHS, Value *RHS);
+ bool exists(Value *V) const;
void add(Value *V, uint32_t num);
void clear();
void erase(Value *v);
}
}
+/// Returns true if a value number exists for the specified value.
+bool ValueTable::exists(Value *V) const { return valueNumbering.count(V) != 0; }
+
/// lookup_or_add - Returns the value number for the specified value, assigning
/// it a new number if it did not have one before.
uint32_t ValueTable::lookup_or_add(Value *V) {
SSAUpdater SSAUpdate(&NewPHIs);
SSAUpdate.Initialize(LI->getType(), LI->getName());
- for (unsigned i = 0, e = ValuesPerBlock.size(); i != e; ++i) {
- const AvailableValueInBlock &AV = ValuesPerBlock[i];
+ for (const AvailableValueInBlock &AV : ValuesPerBlock) {
BasicBlock *BB = AV.BB;
if (SSAUpdate.HasValueForBlock(BB))
// that we only have to insert *one* load (which means we're basically moving
// the load, not inserting a new one).
- SmallPtrSet<BasicBlock *, 4> Blockers;
- for (unsigned i = 0, e = UnavailableBlocks.size(); i != e; ++i)
- Blockers.insert(UnavailableBlocks[i]);
+ SmallPtrSet<BasicBlock *, 4> Blockers(UnavailableBlocks.begin(),
+ UnavailableBlocks.end());
// Let's find the first basic block with more than one predecessor. Walk
// backwards through predecessors if needed.
// available.
MapVector<BasicBlock *, Value *> PredLoads;
DenseMap<BasicBlock*, char> FullyAvailableBlocks;
- for (unsigned i = 0, e = ValuesPerBlock.size(); i != e; ++i)
- FullyAvailableBlocks[ValuesPerBlock[i].BB] = true;
- for (unsigned i = 0, e = UnavailableBlocks.size(); i != e; ++i)
- FullyAvailableBlocks[UnavailableBlocks[i]] = false;
+ for (const AvailableValueInBlock &AV : ValuesPerBlock)
+ FullyAvailableBlocks[AV.BB] = true;
+ for (BasicBlock *UnavailableBB : UnavailableBlocks)
+ FullyAvailableBlocks[UnavailableBB] = false;
SmallVector<BasicBlock *, 4> CriticalEdgePred;
- for (pred_iterator PI = pred_begin(LoadBB), E = pred_end(LoadBB);
- PI != E; ++PI) {
- BasicBlock *Pred = *PI;
+ for (BasicBlock *Pred : predecessors(LoadBB)) {
+ // If any predecessor block is an EH pad that does not allow non-PHI
+ // instructions before the terminator, we can't PRE the load.
+ if (Pred->getTerminator()->isEHPad()) {
+ DEBUG(dbgs()
+ << "COULD NOT PRE LOAD BECAUSE OF AN EH PAD PREDECESSOR '"
+ << Pred->getName() << "': " << *LI << '\n');
+ return false;
+ }
+
if (IsValueFullyAvailableInBlock(Pred, FullyAvailableBlocks, 0)) {
continue;
}
<< *NewInsts.back() << '\n');
// Assign value numbers to the new instructions.
- for (unsigned i = 0, e = NewInsts.size(); i != e; ++i) {
+ for (Instruction *I : NewInsts) {
// FIXME: We really _ought_ to insert these value numbers into their
// parent's availability map. However, in doing so, we risk getting into
// ordering issues. If a block hasn't been processed yet, we would be
// marking a value as AVAIL-IN, which isn't what we intend.
- VN.lookup_or_add(NewInsts[i]);
+ VN.lookup_or_add(I);
}
for (const auto &PredLoad : PredLoads) {
if (Tags)
NewLoad->setAAMetadata(Tags);
+ if (auto *MD = LI->getMetadata(LLVMContext::MD_invariant_load))
+ NewLoad->setMetadata(LLVMContext::MD_invariant_load, MD);
if (auto *InvGroupMD = LI->getMetadata(LLVMContext::MD_invariant_group))
NewLoad->setMetadata(LLVMContext::MD_invariant_group, InvGroupMD);
/// Attempt to eliminate a load whose dependencies are
/// non-local by performing PHI construction.
bool GVN::processNonLocalLoad(LoadInst *LI) {
+ // non-local speculations are not allowed under asan.
+ if (LI->getParent()->getParent()->hasFnAttribute(Attribute::SanitizeAddress))
+ return false;
+
// Step 1: Find the non-local dependencies of the load.
LoadDepVect Deps;
MD->getNonLocalPointerDependency(LI, Deps);
Value *Op = Instr->getOperand(i);
if (isa<Argument>(Op) || isa<Constant>(Op) || isa<GlobalValue>(Op))
continue;
-
+ // This could be a newly inserted instruction, in which case, we won't
+ // find a value number, and should give up before we hurt ourselves.
+ // FIXME: Rewrite the infrastructure to let it easier to value number
+ // and process newly inserted instructions.
+ if (!VN.exists(Op)) {
+ success = false;
+ break;
+ }
if (Value *V = findLeader(Pred, VN.lookup(Op))) {
Instr->setOperand(i, V);
} else {
BasicBlock *CurrentBlock = CurInst->getParent();
predMap.clear();
- for (pred_iterator PI = pred_begin(CurrentBlock), PE = pred_end(CurrentBlock);
- PI != PE; ++PI) {
- BasicBlock *P = *PI;
+ for (BasicBlock *P : predecessors(CurrentBlock)) {
// We're not interested in PRE where the block is its
// own predecessor, or in blocks with predecessors
// that are not reachable.
BE = CurrentBlock->end();
BI != BE;) {
Instruction *CurInst = &*BI++;
- Changed = performScalarPRE(CurInst);
+ Changed |= performScalarPRE(CurInst);
}
}
DeadBlocks.insert(Dom.begin(), Dom.end());
// Figure out the dominance-frontier(D).
- for (SmallVectorImpl<BasicBlock *>::iterator I = Dom.begin(),
- E = Dom.end(); I != E; I++) {
- BasicBlock *B = *I;
- for (succ_iterator SI = succ_begin(B), SE = succ_end(B); SI != SE; SI++) {
- BasicBlock *S = *SI;
+ for (BasicBlock *B : Dom) {
+ for (BasicBlock *S : successors(B)) {
if (DeadBlocks.count(S))
continue;
bool AllPredDead = true;
- for (pred_iterator PI = pred_begin(S), PE = pred_end(S); PI != PE; PI++)
- if (!DeadBlocks.count(*PI)) {
+ for (BasicBlock *P : predecessors(S))
+ if (!DeadBlocks.count(P)) {
AllPredDead = false;
break;
}
continue;
SmallVector<BasicBlock *, 4> Preds(pred_begin(B), pred_end(B));
- for (SmallVectorImpl<BasicBlock *>::iterator PI = Preds.begin(),
- PE = Preds.end(); PI != PE; PI++) {
- BasicBlock *P = *PI;
-
+ for (BasicBlock *P : Preds) {
if (!DeadBlocks.count(P))
continue;
// instructions, it makes more sense just to "fabricate" a val-number for the
// dead code than checking if instruction involved is dead or not.
void GVN::assignValNumForDeadCode() {
- for (SetVector<BasicBlock *>::iterator I = DeadBlocks.begin(),
- E = DeadBlocks.end(); I != E; I++) {
- BasicBlock *BB = *I;
- for (BasicBlock::iterator II = BB->begin(), EE = BB->end();
- II != EE; II++) {
- Instruction *Inst = &*II;
- unsigned ValNum = VN.lookup_or_add(Inst);
- addToLeaderTable(ValNum, Inst, BB);
+ for (BasicBlock *BB : DeadBlocks) {
+ for (Instruction &Inst : *BB) {
+ unsigned ValNum = VN.lookup_or_add(&Inst);
+ addToLeaderTable(ValNum, &Inst, BB);
}
}
}