(defmacro mfoo () '(lambda (z) (1+ z)))

;; f-macro has a function call to a compiled lambda in disassembly

(defun f-macro (x)
  (declare (optimize (speed 3) (safety 0) (debug 0)))
  (funcall (mfoo) x))

;; f-bare and f-flet-macro have the same disassembly, and both call
;; #'1+ directly

(defun f-bare (x)
  (declare (optimize (speed 3) (safety 0) (debug 0)))
  (funcall (lambda (z) (1+ z)) x))

(defun f-flet-macro (x)
  (declare (optimize (speed 3) (safety 0) (debug 0)))
  (flet ((f (x) (funcall (mfoo) x)))
    (funcall #'f x)))