sbcl optimization bug

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

;; f-macro, f-symb-macro, f-macrolet have a function call to a compiled lambda in disassembly

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

(defun f-symb-macro (x)
  (declare (optimize (speed 3) (safety 0) (debug 0)))
  (symbol-macrolet ((mfoo-new (lambda (z) (1+ z))))
    (funcall mfoo-new x)))

(defun f-macrolet (x)
  (declare (optimize (speed 3) (safety 0) (debug 0)))
  (macrolet ((mfoo-new () '(lambda (z) (1+ z))))
    (funcall (mfoo-new) 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)))