bool LoopReroll::DAGRootTracker::collectUsedInstructions(SmallInstructionSet &PossibleRedSet) {
// Populate the MapVector with all instructions in the block, in order first,
// so we can iterate over the contents later in perfect order.
for (auto &I : *L->getHeader()) {
Uses[&I].resize(IL_End);
}
SmallInstructionSet Exclude;
Exclude.insert(Roots.begin(), Roots.end());
Exclude.insert(LoopIncs.begin(), LoopIncs.end());
DenseSet<Instruction*> VBase;
collectInLoopUserSet(IV, Exclude, PossibleRedSet, VBase);
for (auto *I : VBase) {
Uses[I].set(0);
}
unsigned Idx = 1;
for (auto *Root : Roots) {
DenseSet<Instruction*> V;
collectInLoopUserSet(Root, Exclude, PossibleRedSet, V);
// While we're here, check the use sets are the same size.
if (V.size() != VBase.size()) {
DEBUG(dbgs() << "LRR: Aborting - use sets are different sizes\n");
return false;
}
for (auto *I : V) {
Uses[I].set(Idx);
}
++Idx;
}
// Make sure the loop increments are also accounted for.
Exclude.clear();
Exclude.insert(Roots.begin(), Roots.end());
DenseSet<Instruction*> V;
collectInLoopUserSet(LoopIncs, Exclude, PossibleRedSet, V);
for (auto *I : V) {
Uses[I].set(IL_LoopIncIdx);
}
if (IV != RealIV)
Uses[RealIV].set(IL_LoopIncIdx);
return true;
}
