avoid unnecessary and expensive creation of FqName instances

core/descriptors/src/org/jetbrains/kotlin/builtins/KotlinBuiltIns.java

@@ -827,7 +827,9 @@ public class KotlinBuiltIns {
 
     private static boolean isConstructedFromGivenClass(@NotNull JetType type, @NotNull FqNameUnsafe fqName) {
         ClassifierDescriptor descriptor = type.getConstructor().getDeclarationDescriptor();
-        return descriptor != null && fqName.equals(getFqName(descriptor));
+        return descriptor != null &&
+               /* quick check to avoid creation of full FqName instance */ descriptor.getName().equals(fqName.shortName()) &&
+               fqName.equals(getFqName(descriptor));
     }
 
     private static boolean isNotNullConstructedFromGivenClass(@NotNull JetType type, @NotNull FqNameUnsafe fqName) {

core/descriptors/src/org/jetbrains/kotlin/types/AbstractClassTypeConstructor.java

@@ -23,9 +23,16 @@ import org.jetbrains.kotlin.name.FqNameUnsafe;
 import org.jetbrains.kotlin.resolve.DescriptorUtils;
 
 public abstract class AbstractClassTypeConstructor implements TypeConstructor {
+    private boolean hashCodeComputed;
+    private int hashCode;
+
     @Override
     public final int hashCode() {
-        return hashCode(this);
+        if (!hashCodeComputed) {
+            hashCodeComputed = true;
+            hashCode = hashCode(this);
+        }
+        return hashCode;
     }
 
     @Override