// A helper function that explores sync dependents of TI.
void exploreSyncDependency(TerminatorInst *TI);
// Computes the influence region from Start to End. This region includes all
- // basic blocks on any path from Start to End.
+ // basic blocks on any simple path from Start to End.
void computeInfluenceRegion(BasicBlock *Start, BasicBlock *End,
DenseSet<BasicBlock *> &InfluenceRegion);
// Finds all users of I that are outside the influence region, and add these
}
}
+// A helper function for computeInfluenceRegion that adds successors of "ThisBB"
+// to the influence region.
+static void
+addSuccessorsToInfluenceRegion(BasicBlock *ThisBB, BasicBlock *End,
+ DenseSet<BasicBlock *> &InfluenceRegion,
+ std::vector<BasicBlock *> &InfluenceStack) {
+ for (BasicBlock *Succ : successors(ThisBB)) {
+ if (Succ != End && InfluenceRegion.insert(Succ).second)
+ InfluenceStack.push_back(Succ);
+ }
+}
+
void DivergencePropagator::computeInfluenceRegion(
BasicBlock *Start, BasicBlock *End,
DenseSet<BasicBlock *> &InfluenceRegion) {
assert(PDT.properlyDominates(End, Start) &&
"End does not properly dominate Start");
+
+ // The influence region starts from the end of "Start" to the beginning of
+ // "End". Therefore, "Start" should not be in the region unless "Start" is in
+ // a loop that doesn't contain "End".
std::vector<BasicBlock *> InfluenceStack;
- InfluenceStack.push_back(Start);
- InfluenceRegion.insert(Start);
+ addSuccessorsToInfluenceRegion(Start, End, InfluenceRegion, InfluenceStack);
while (!InfluenceStack.empty()) {
BasicBlock *BB = InfluenceStack.back();
InfluenceStack.pop_back();
- for (BasicBlock *Succ : successors(BB)) {
- if (End != Succ && InfluenceRegion.insert(Succ).second)
- InfluenceStack.push_back(Succ);
- }
+ addSuccessorsToInfluenceRegion(BB, End, InfluenceRegion, InfluenceStack);
}
}