Cache declarations

Author: asl

lib/AST/ASTContext.cpp

@@ -343,6 +343,12 @@ struct ASTContext::Implementation {
   /// The declaration of Swift.Optional<T>.None.
   EnumElementDecl *OptionalNoneDecl = nullptr;
 
+  /// The declaration of Optional<T>.TangentVector.init
+  ConstructorDecl *OptionalTanInitDecl = nullptr;
+
+  /// The declaration of Optional<T>.TangentVector.value
+  VarDecl *OptionalTanValueDecl = nullptr;
+  
   /// The declaration of Swift.Void.
   TypeAliasDecl *VoidDecl = nullptr;
 
@@ -2246,41 +2252,49 @@ void ASTContext::loadObjCMethods(
 }
 
 ConstructorDecl *ASTContext::getOptionalTanInitDecl(CanType optionalTanType) {
-  auto *optionalTanDecl = optionalTanType.getNominalOrBoundGenericNominal();
-  // Look up the `Optional<T>.TangentVector.init` declaration.
-  auto initLookup =
-    optionalTanDecl->lookupDirect(DeclBaseName::createConstructor());
-  ConstructorDecl *constructorDecl = nullptr;
-  for (auto *candidate : initLookup) {
-    auto candidateModule = candidate->getModuleContext();
-    if (candidateModule->getName() == Id_Differentiation ||
-        candidateModule->isStdlibModule()) {
-      assert(!constructorDecl && "Multiple `Optional.TangentVector.init`s");
-      constructorDecl = cast<ConstructorDecl>(candidate);
+  if (!getImpl().OptionalTanInitDecl) {
+    auto *optionalTanDecl = optionalTanType.getNominalOrBoundGenericNominal();
+    // Look up the `Optional<T>.TangentVector.init` declaration.
+    auto initLookup =
+      optionalTanDecl->lookupDirect(DeclBaseName::createConstructor());
+    ConstructorDecl *constructorDecl = nullptr;
+    for (auto *candidate : initLookup) {
+      auto candidateModule = candidate->getModuleContext();
+      if (candidateModule->getName() == Id_Differentiation ||
+          candidateModule->isStdlibModule()) {
+        assert(!constructorDecl && "Multiple `Optional.TangentVector.init`s");
+        constructorDecl = cast<ConstructorDecl>(candidate);
 #ifdef NDEBUG
-      break;
+        break;
 #endif
+      }
     }
+    assert(constructorDecl && "No `Optional.TangentVector.init`");
+
+    getImpl().OptionalTanInitDecl = constructorDecl;
   }
-  assert(constructorDecl && "No `Optional.TangentVector.init`");
 
-  return constructorDecl;
+  return getImpl().OptionalTanInitDecl;
 }
 
 VarDecl *ASTContext::getOptionalTanValueDecl(CanType optionalTanType) {
-  // TODO: Maybe it would be better to have getters / setters here that we
-  // can call and hide this implementation detail?
-  StructDecl *optStructDecl = optionalTanType.getStructOrBoundGenericStruct();
-  assert(optStructDecl && "Unexpected type of Optional.TangentVector");
+  if (!getImpl().OptionalTanValueDecl) {
+    // TODO: Maybe it would be better to have getters / setters here that we
+    // can call and hide this implementation detail?
+    StructDecl *optStructDecl = optionalTanType.getStructOrBoundGenericStruct();
+    assert(optStructDecl && "Unexpected type of Optional.TangentVector");
 
-  ArrayRef<VarDecl *> properties = optStructDecl->getStoredProperties();
-  assert(properties.size() == 1 && "Unexpected type of Optional.TangentVector");
-  VarDecl *wrappedValueVar = properties[0];
+    ArrayRef<VarDecl *> properties = optStructDecl->getStoredProperties();
+    assert(properties.size() == 1 && "Unexpected type of Optional.TangentVector");
+    VarDecl *wrappedValueVar = properties[0];
 
-  assert(wrappedValueVar->getTypeInContext()->getEnumOrBoundGenericEnum() ==
-         getOptionalDecl() && "Unexpected type of Optional.TangentVector");
+    assert(wrappedValueVar->getTypeInContext()->getEnumOrBoundGenericEnum() ==
+           getOptionalDecl() && "Unexpected type of Optional.TangentVector");
+
+    getImpl().OptionalTanValueDecl = wrappedValueVar;
+  }
 
-  return wrappedValueVar;
+  return getImpl().OptionalTanValueDecl;
 }
 
 void ASTContext::loadDerivativeFunctionConfigurations(