2 files changed, 11 insertions, 4 deletions

diff --git a/lisp/emacs-lisp/byte-run.el b/lisp/emacs-lisp/byte-run.el
index 8c16c172bed..8993a8169dd 100644
--- a/lisp/emacs-lisp/byte-run.el
+++ b/lisp/emacs-lisp/byte-run.el
@@ -258,6 +258,9 @@ The return value is undefined.
                (cons 'prog1 (cons def declarations))
              def))))))
 
+(defvar defun-last-function-name nil
+  "Last function name macroexpanded by `defun'.")
+
 ;; Now that we defined defmacro we can use it!
 (defmacro defun (name arglist &optional docstring &rest body)
   "Define NAME as a function.
@@ -280,6 +283,7 @@ The return value is undefined.
        (and (listp arglist)
             (null (delq t (mapcar #'symbolp arglist)))))
       (error "Malformed arglist: %s" arglist))
+  (setq defun-last-function-name name)
   (let ((decls (cond
                 ((eq (car-safe docstring) 'declare)
                  (prog1 (cdr docstring) (setq docstring nil)))
diff --git a/lisp/emacs-lisp/cl-macs.el b/lisp/emacs-lisp/cl-macs.el
index 75da0394067..235e7d0d75b 100644
--- a/lisp/emacs-lisp/cl-macs.el
+++ b/lisp/emacs-lisp/cl-macs.el
@@ -2374,10 +2374,13 @@ values.  For compatibility, (cl-values A B C) is a synonym for (list A B C).
                             '((0 nil) (1 t) (2 t) (3 t))))
                (safety (assq (nth 1 (assq 'safety (cdr spec)))
                              '((0 t) (1 t) (2 t) (3 nil)))))
-           (if speed (setq cl--optimize-speed (car speed)
-                           byte-optimize (nth 1 speed)))
-           (if safety (setq cl--optimize-safety (car safety)
-                            byte-compile-delete-errors (nth 1 safety)))))
+           (when speed
+             (setq cl--optimize-speed (car speed)
+                   byte-optimize (nth 1 speed))
+             (function-put defun-last-function-name 'speed cl--optimize-speed))
+           (when safety
+             (setq cl--optimize-safety (car safety)
+                   byte-compile-delete-errors (nth 1 safety)))))
 
         ((and (eq (car-safe spec) 'warn) (boundp 'byte-compile-warnings))
          (while (setq spec (cdr spec))