Index: /trunk/ccl/compiler/optimizers.lisp
===================================================================
--- /trunk/ccl/compiler/optimizers.lisp	(revision 4909)
+++ /trunk/ccl/compiler/optimizers.lisp	(revision 4910)
@@ -1535,4 +1535,7 @@
   `(eql (typecode ,n) ,(nx-lookup-target-uvector-subtag :macptr)))
 
+(define-compiler-macro basic-stream-p (n)
+  `(eql (typecode ,n) ,(nx-lookup-target-uvector-subtag :basic-stream)))
+
 (define-compiler-macro aref (&whole call a &rest subscripts &environment env)
   (let* ((ctype (if (nx-form-typep a 'array env)