Cache _MaxBuiltinFloatType

period

Author: Azoy

include/swift/AST/ASTContext.h

@@ -530,6 +530,9 @@ class ASTContext final {
 
   // Retrieve the declaration of Swift._stdlib_isOSVersionAtLeast.
   FuncDecl *getIsOSVersionAtLeastDecl() const;
+
+  // Retrieve the declaration of Swift._MaxBuiltinFloatType.
+  TypeAliasDecl *getMaxBuiltinFloatTypeDecl() const;
 
   /// Look for the declaration with the given name within the
   /// Swift module.

lib/AST/ASTContext.cpp

@@ -206,6 +206,9 @@ FOR_KNOWN_FOUNDATION_TYPES(CACHE_FOUNDATION_DECL)
   //    -> Builtin.Int1
   FuncDecl *IsOSVersionAtLeastDecl = nullptr;
 
+  /// typealias Swift._MaxBuiltinFloatType
+  TypeAliasDecl *MaxBuiltinFloatTypeDecl = nullptr;
+
   /// The set of known protocols, lazily populated as needed.
   ProtocolDecl *KnownProtocols[NumKnownProtocols] = { };
 
@@ -1177,6 +1180,25 @@ FuncDecl *ASTContext::getIsOSVersionAtLeastDecl() const {
   return decl;
 }
 
+TypeAliasDecl *ASTContext::getMaxBuiltinFloatTypeDecl() const {
+  if (getImpl().MaxBuiltinFloatTypeDecl)
+    return getImpl().MaxBuiltinFloatTypeDecl;
+
+  // Go find '_MaxBuiltinFloatType' in the Swift module.
+  SmallVector<ValueDecl *, 1> results;
+  lookupInSwiftModule("_MaxBuiltinFloatType", results);
+
+  if (results.size() != 1)
+    return nullptr;
+
+  if (auto typeAlias = dyn_cast<TypeAliasDecl>(results.front())) {
+    getImpl().MaxBuiltinFloatTypeDecl = typeAlias;
+    return typeAlias;
+  }
+
+  return nullptr;
+}
+
 static bool isHigherPrecedenceThan(PrecedenceGroupDecl *a,
                                    PrecedenceGroupDecl *b) {
   assert(a != b && "exact match should already have been filtered");

lib/Sema/CSApply.cpp

@@ -1834,8 +1834,6 @@ namespace {
     Expr *forceBridgeFromObjectiveC(Expr *object, Type valueType) {
       return bridgeFromObjectiveC(object, valueType, false);
     }
-
-    TypeAliasDecl *MaxFloatTypeDecl = nullptr;
 
   public:
     ExprRewriter(ConstraintSystem &cs, const Solution &solution,
@@ -2002,25 +2000,18 @@ namespace {
           type = defaultType;
       }
 
-      // Find the maximum-sized builtin float type.
-      // FIXME: Cache name lookup.
-      if (!MaxFloatTypeDecl) {
-        SmallVector<ValueDecl *, 1> lookupResults;
-        tc.getStdlibModule(dc)->lookupValue(/*AccessPath=*/{},
-                                            tc.Context.Id_MaxBuiltinFloatType,
-                                            NLKind::QualifiedLookup,
-                                            lookupResults);
-        if (lookupResults.size() == 1)
-          MaxFloatTypeDecl = dyn_cast<TypeAliasDecl>(lookupResults.front());
-      }
-      if (!MaxFloatTypeDecl ||
-          !MaxFloatTypeDecl->hasInterfaceType() ||
-          !MaxFloatTypeDecl->getDeclaredInterfaceType()->is<BuiltinFloatType>()) {
+      // Get the _MaxBuiltinFloatType decl, or look for it if it's not cached.
+      auto maxFloatTypeDecl = tc.Context.getMaxBuiltinFloatTypeDecl();
+
+      if (!maxFloatTypeDecl ||
+          !maxFloatTypeDecl->hasInterfaceType() ||
+          !maxFloatTypeDecl->getDeclaredInterfaceType()->is<BuiltinFloatType>()) {
         tc.diagnose(expr->getLoc(), diag::no_MaxBuiltinFloatType_found);
         return nullptr;
       }
-      tc.validateDecl(MaxFloatTypeDecl);
-      auto maxType = MaxFloatTypeDecl->getUnderlyingTypeLoc().getType();
+
+      tc.validateDecl(maxFloatTypeDecl);
+      auto maxType = maxFloatTypeDecl->getUnderlyingTypeLoc().getType();
 
       DeclName initName(tc.Context, DeclBaseName::createConstructor(),
                         { tc.Context.Id_floatLiteral });