X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcompiler%2Fknownfun.lisp;h=e12181513dec21e881f2fc81d37c0c566883ff17;hb=f3491f128307938cc56367f739b8fbf9e5d503b6;hp=863dbb395e5e0ece6f2ddbc569bc62a18de73277;hpb=5d04a95274c9ddaebbcd6ddffc5d646e2c25598c;p=sbcl.git

diff --git a/src/compiler/knownfun.lisp b/src/compiler/knownfun.lisp
index 863dbb3..e121815 100644
--- a/src/compiler/knownfun.lisp
+++ b/src/compiler/knownfun.lisp
@@ -131,7 +131,10 @@
   (templates nil :type list)
   ;; If non-null, then this function is a unary type predicate for
   ;; this type.
-  (predicate-type nil :type (or ctype null)))
+  (predicate-type nil :type (or ctype null))
+  ;; If non-null, the index of the argument which becomes the result
+  ;; of the function.
+  (result-arg nil :type (or index null)))
 
 (defprinter (fun-info)
   (attributes :test (not (zerop attributes))
@@ -197,15 +200,17 @@
 (declaim (ftype (function (list list attributes &key
                                 (:derive-type (or function null))
                                 (:optimizer (or function null))
-                                (:destroyed-constant-args (or function null)))
+                                (:destroyed-constant-args (or function null))
+                                (:result-arg (or index null)))
                           *)
                 %defknown))
-(defun %defknown (names type attributes &key derive-type optimizer destroyed-constant-args)
+(defun %defknown (names type attributes &key derive-type optimizer destroyed-constant-args result-arg)
   (let ((ctype (specifier-type type))
         (info (make-fun-info :attributes attributes
                              :derive-type derive-type
                              :optimizer optimizer
-                             :destroyed-constant-args destroyed-constant-args))
+                             :destroyed-constant-args destroyed-constant-args
+                             :result-arg result-arg))
         (target-env *info-environment*))
     (dolist (name names)
       (let ((old-fun-info (info :function :info name)))