// Do a quadratic search on all of the given stores and find
// all of the pairs of stores that follow each other.
+ SmallVector<unsigned, 16> IndexQueue;
for (unsigned i = 0, e = Stores.size(); i < e; ++i) {
- for (unsigned j = 0; j < e; ++j) {
- if (i == j)
- continue;
- const DataLayout &DL = Stores[i]->getModule()->getDataLayout();
- if (R.isConsecutiveAccess(Stores[i], Stores[j], DL)) {
- Tails.insert(Stores[j]);
+ const DataLayout &DL = Stores[i]->getModule()->getDataLayout();
+ IndexQueue.clear();
+ // If a store has multiple consecutive store candidates, search Stores
+ // array according to the sequence: from i+1 to e, then from i-1 to 0.
+ // This is because usually pairing with immediate succeeding or preceding
+ // candidate create the best chance to find slp vectorization opportunity.
+ unsigned j = 0;
+ for (j = i + 1; j < e; ++j)
+ IndexQueue.push_back(j);
+ for (j = i; j > 0; --j)
+ IndexQueue.push_back(j - 1);
+
+ for (auto &k : IndexQueue) {
+ if (R.isConsecutiveAccess(Stores[i], Stores[k], DL)) {
+ Tails.insert(Stores[k]);
Heads.insert(Stores[i]);
- ConsecutiveChain[Stores[i]] = Stores[j];
+ ConsecutiveChain[Stores[i]] = Stores[k];
+ break;
}
}
}