- ;; A continuation for which all control-related slots have the
- ;; default values. A continuation is unused during IR1 conversion
- ;; until it is assigned a block, and may be also be temporarily
- ;; unused during later manipulations of IR1. In a consistent
- ;; state there should never be any mention of :UNUSED
- ;; continuations. NEXT can have a non-null value if the next node
- ;; has already been determined.
- ;;
- ;; :DELETED
- ;; A continuation that has been deleted from IR1. Any pointers into
- ;; IR1 are cleared. There are two conditions under which a deleted
- ;; continuation may appear in code:
- ;; -- The CONT of the LAST node in a block may be a deleted
- ;; continuation when the original receiver of the continuation's
- ;; value was deleted. Note that DEST in a deleted continuation is
- ;; null, so it is easy to know not to attempt delivering any
- ;; values to the continuation.
- ;; -- Unreachable code that hasn't been deleted yet may receive
- ;; deleted continuations. All such code will be in blocks that
- ;; have DELETE-P set. All unreachable code is deleted by control
- ;; optimization, so the backend doesn't have to worry about this.
+ ;; A continuation for which all control-related slots have the
+ ;; default values. A continuation is unused during IR1 conversion
+ ;; until it is assigned a block, and may be also be temporarily
+ ;; unused during later manipulations of IR1. In a consistent
+ ;; state there should never be any mention of :UNUSED
+ ;; continuations. NEXT can have a non-null value if the next node
+ ;; has already been determined.