AttributeSet AttributeSet::get(LLVMContext &C, ArrayRef<AttributeSet> Attrs) {
if (Attrs.empty()) return AttributeSet();
+ if (Attrs.size() == 1) return Attrs[0];
SmallVector<std::pair<unsigned, AttributeSetNode*>, 8> AttrNodeVec;
- for (unsigned I = 0, E = Attrs.size(); I != E; ++I) {
+ AttributeSetImpl *A0 = Attrs[0].pImpl;
+ if (A0)
+ AttrNodeVec.append(A0->getNode(0), A0->getNode(A0->getNumAttributes()));
+ // Copy all attributes from Attrs into AttrNodeVec while keeping AttrNodeVec
+ // ordered by index. Because we know that each list in Attrs is ordered by
+ // index we only need to merge each successive list in rather than doing a
+ // full sort.
+ for (unsigned I = 1, E = Attrs.size(); I != E; ++I) {
AttributeSetImpl *AS = Attrs[I].pImpl;
if (!AS) continue;
- AttrNodeVec.append(AS->getNode(0), AS->getNode(AS->getNumAttributes()));
+ SmallVector<std::pair<unsigned, AttributeSetNode *>, 8>::iterator
+ ANVI = AttrNodeVec.begin(), ANVE;
+ for (const AttributeSetImpl::IndexAttrPair
+ *AI = AS->getNode(0),
+ *AE = AS->getNode(AS->getNumAttributes());
+ AI != AE; ++AI) {
+ ANVE = AttrNodeVec.end();
+ while (ANVI != ANVE && ANVI->first <= AI->first)
+ ++ANVI;
+ ANVI = AttrNodeVec.insert(ANVI, *AI) + 1;
+ }
}
return getImpl(C, AttrNodeVec);