+void InstrInfoEmitter::DetectRegisterClassBarriers(std::vector<Record*> &Defs,
+ const std::vector<CodeGenRegisterClass> &RCs,
+ std::vector<Record*> &Barriers) {
+ std::set<Record*> DefSet;
+ unsigned NumDefs = Defs.size();
+ for (unsigned i = 0; i < NumDefs; ++i)
+ DefSet.insert(Defs[i]);
+
+ for (unsigned i = 0, e = RCs.size(); i != e; ++i) {
+ const CodeGenRegisterClass &RC = RCs[i];
+ unsigned NumRegs = RC.Elements.size();
+ if (NumRegs > NumDefs)
+ continue; // Can't possibly clobber this RC.
+
+ bool Clobber = true;
+ for (unsigned j = 0; j < NumRegs; ++j) {
+ Record *Reg = RC.Elements[j];
+ if (!DefSet.count(Reg)) {
+ Clobber = false;
+ break;
+ }
+ }
+ if (Clobber)
+ Barriers.push_back(RC.TheDef);
+ }
+}
+