SmallVector<Instruction *, 8> Worklist;
SmallPtrSet<Instruction *, 16> DeadInstructions;
+ // We keep a very small set of operands that we use to de-duplicate things
+ // when inserting into the worklist. This lets us handle duplicates within
+ // a single instruction's operands without buring lots of memory on the
+ // worklist.
+ SmallPtrSet<Instruction *, 4> OperandSet;
+
// Start by initializing worklist with simplified instructions.
for (auto &FoldedKeyValue : SimplifiedValues)
if (auto *FoldedInst = dyn_cast<Instruction>(FoldedKeyValue.first)) {
// Add each instruction operand of this dead instruction to the
// worklist.
+ OperandSet.clear();
for (auto *Op : FoldedInst->operand_values())
if (auto *OpI = dyn_cast<Instruction>(Op))
- Worklist.push_back(OpI);
+ if (OperandSet.insert(OpI).second)
+ Worklist.push_back(OpI);
}
// If a definition of an insn is only used by simplified or dead
if (AllUsersFolded) {
NumberOfOptimizedInstructions += TTI.getUserCost(I);
DeadInstructions.insert(I);
+ OperandSet.clear();
for (auto *Op : I->operand_values())
if (auto *OpI = dyn_cast<Instruction>(Op))
- Worklist.push_back(OpI);
+ if (OperandSet.insert(OpI).second)
+ Worklist.push_back(OpI);
}
}
return NumberOfOptimizedInstructions;