Instruction* dependency,
SetVector<Instruction*>& possiblyDead);
bool handleEndBlock(BasicBlock& BB, SetVector<Instruction*>& possiblyDead);
- bool RemoveUndeadPointers(Value* pointer,
+ bool RemoveUndeadPointers(Value* pointer, uint64_t killPointerSize,
BasicBlock::iterator& BBI,
SmallPtrSet<Value*, 64>& deadPointers,
SetVector<Instruction*>& possiblyDead);
}
Value* killPointer = 0;
+ uint64_t killPointerSize = ~0UL;
// If we encounter a use of the pointer, it is no longer considered dead
if (LoadInst* L = dyn_cast<LoadInst>(BBI)) {
// However, if this load is unused, we can go ahead and remove it, and
// not have to worry about it making our pointer undead!
- if (L->getNumUses() == 0) {
+ if (L->use_empty()) {
MD.removeInstruction(L);
// DCE instructions only used to calculate that load
killPointer = L->getPointerOperand();
} else if (VAArgInst* V = dyn_cast<VAArgInst>(BBI)) {
killPointer = V->getOperand(0);
+ } else if (isa<MemCpyInst>(BBI) &&
+ isa<ConstantInt>(cast<MemCpyInst>(BBI)->getLength())) {
+ killPointer = cast<MemCpyInst>(BBI)->getSource();
+ killPointerSize = cast<ConstantInt>(
+ cast<MemCpyInst>(BBI)->getLength())->getZExtValue();
} else if (AllocaInst* A = dyn_cast<AllocaInst>(BBI)) {
deadPointers.erase(A);
// Dead alloca's can be DCE'd when we reach them
- if (A->getNumUses() == 0) {
+ if (A->use_empty()) {
MD.removeInstruction(A);
// DCE instructions only used to calculate that load
} else {
// For any non-memory-affecting non-terminators, DCE them as we reach them
Instruction *CI = BBI;
- if (!CI->isTerminator() && CI->getNumUses() == 0) {
+ if (!CI->isTerminator() && CI->use_empty() && !isa<FreeInst>(CI)) {
// DCE instructions only used to calculate that load
for (Instruction::op_iterator OI = CI->op_begin(), OE = CI->op_end();
TranslatePointerBitCasts(killPointer);
// Deal with undead pointers
- MadeChange |= RemoveUndeadPointers(killPointer, BBI,
+ MadeChange |= RemoveUndeadPointers(killPointer, killPointerSize, BBI,
deadPointers, possiblyDead);
}
/// RemoveUndeadPointers - check for uses of a pointer that make it
/// undead when scanning for dead stores to alloca's.
-bool DSE::RemoveUndeadPointers(Value* killPointer,
+bool DSE::RemoveUndeadPointers(Value* killPointer, uint64_t killPointerSize,
BasicBlock::iterator& BBI,
SmallPtrSet<Value*, 64>& deadPointers,
SetVector<Instruction*>& possiblyDead) {
// See if this pointer could alias it
AliasAnalysis::AliasResult A = AA.alias(*I, pointerSize,
- killPointer, ~0U);
+ killPointer, killPointerSize);
// If it must-alias and a store, we can delete it
if (isa<StoreInst>(BBI) && A == AliasAnalysis::MustAlias) {