;; in the safe code. If a function MUST signal errors, then it is
;; not unsafely-flushable even if it is movable or foldable.
unsafely-flushable
+ ;; return value is important, and ignoring it is probably a mistake.
+ ;; Unlike the other attributes, this is used only for style
+ ;; warnings and has no effect on optimization.
+ important-result
;; may be moved with impunity. Has no side effects except possibly
;; consing, and is affected only by its arguments.
;;