implementing find interface for RootSignatureAnalysisWrapper

Author: joaosaffran

llvm/lib/Target/DirectX/DXContainerGlobals.cpp

@@ -164,17 +164,16 @@ void DXContainerGlobals::addRootSignature(Module &M,
 
   auto &RSA = getAnalysis<RootSignatureAnalysisWrapper>();
   const Function *EntryFunction = MMI.EntryPropertyVec[0].Entry;
-  const std::optional<RootSignatureDesc> &MaybeRS =
-      RSA.getForFunction(EntryFunction);
+  const auto &FuncRs = RSA.find(EntryFunction);
 
-  if (!MaybeRS.has_value())
+  if (FuncRs == RSA.end())
     return;
 
-  const RootSignatureDesc &RSH = MaybeRS.value();
+  const RootSignatureDesc &RS = FuncRs->getSecond();
   SmallString<256> Data;
   raw_svector_ostream OS(Data);
 
-  RSH.write(OS);
+  RS.write(OS);
 
   Constant *Constant =
       ConstantDataArray::getString(M.getContext(), Data, /*AddNull*/ false);

llvm/lib/Target/DirectX/DXILRootSignature.h

@@ -51,12 +51,12 @@ class RootSignatureAnalysisWrapper : public ModulePass {
 
   RootSignatureAnalysisWrapper() : ModulePass(ID) {}
 
-  std::optional<mcdxbc::RootSignatureDesc> getForFunction(const Function *F) {
-    auto Lookup = FuncToRsMap.find(F);
-    if (Lookup == FuncToRsMap.end())
-      return std::nullopt;
-    return Lookup->second;
-  }
+  using iterator =
+      SmallDenseMap<const Function *, mcdxbc::RootSignatureDesc>::iterator;
+
+  iterator find(const Function *F) { return FuncToRsMap.find(F); }
+
+  iterator end() { return FuncToRsMap.end(); }
 
   bool runOnModule(Module &M) override;