AST: Early return from substOpaqueTypesWithUnderlyingTypes() overloads if nothing to do

Author: slavapestov

lib/AST/SubstitutionMap.cpp

@@ -620,6 +620,18 @@ bool SubstitutionMap::isIdentity() const {
 
 SubstitutionMap swift::substOpaqueTypesWithUnderlyingTypes(
     SubstitutionMap subs, TypeExpansionContext context) {
+  if (!context.shouldLookThroughOpaqueTypeArchetypes())
+    return subs;
+
+  if (!subs.getRecursiveProperties().hasOpaqueArchetype() &&
+      !llvm::any_of(subs.getConformances(),
+                    [&](ProtocolConformanceRef ref) {
+                      return (!ref.isInvalid() &&
+                              ref.getType()->hasOpaqueArchetype());
+                    })) {
+    return subs;
+  }
+
   ReplaceOpaqueTypesWithUnderlyingTypes replacer(
       context.getContext(), context.getResilienceExpansion(),
       context.isWholeModuleContext());

lib/AST/TypeSubstitution.cpp

@@ -1089,6 +1089,13 @@ swift::substOpaqueTypesWithUnderlyingTypes(CanType ty,
 
 ProtocolConformanceRef swift::substOpaqueTypesWithUnderlyingTypes(
     ProtocolConformanceRef ref, TypeExpansionContext context) {
+  if (ref.isInvalid())
+    return ref;
+
+  if (!context.shouldLookThroughOpaqueTypeArchetypes() ||
+      !ref.getType()->hasOpaqueArchetype())
+    return ref;
+
   ReplaceOpaqueTypesWithUnderlyingTypes replacer(
       context.getContext(), context.getResilienceExpansion(),
       context.isWholeModuleContext());