- ;; :stack-grows-downward, :stack-grows-downward
- ;; One of these two should be present in the features list of any
- ;; CPU supported as of sbcl-0.7.1.29. On the X86, the system stack
- ;; grows downward. On the other supported CPU architectures, the
- ;; system stack grows upward.
+ ;; :control-stack-grows-downward-not-upward
+ ;; On the X86, the Lisp control stack grows downward. On the
+ ;; other supported CPU architectures as of sbcl-0.7.1.40, the
+ ;; system stack grows upward.
+ ;; Note that there are other stack-related differences between the
+ ;; X86 port and the other ports. E.g. on the X86, the Lisp control
+ ;; stack coincides with the C stack, meaning that on the X86 there's
+ ;; stuff on the control stack that the Lisp-level debugger doesn't
+ ;; understand very well. As of sbcl-0.7.1.40 things like that are
+ ;; just parameterized by #!+X86, but it'd probably be better to
+ ;; use new flags like :CONTROL-STACK-CONTAINS-C-STACK.
+ ;;
+ ;; :stack-allocatable-closures
+ ;; The compiler can allocate dynamic-extent closures on stack.