0.pre7.86.flaky7.23:

[sbcl.git] / src / compiler / node.lisp

diff --git a/src/compiler/node.lisp b/src/compiler/node.lisp
index abda10b..dcb0a69 100644 (file)
--- a/src/compiler/node.lisp
+++ b/src/compiler/node.lisp
@@ -84,7 +84,7 @@
   ;; cached type of this continuation's value. If NIL, then this must
   ;; be recomputed: see CONTINUATION-DERIVED-TYPE.
   (%derived-type nil :type (or ctype null))
-  ;; Node where this continuation is used, if unique. This is always
+  ;; the node where this continuation is used, if unique. This is always
   ;; null in :DELETED and :UNUSED continuations, and is never null in
   ;; :INSIDE-BLOCK continuations. In a :BLOCK-START continuation, the
   ;; Block's START-USES indicate whether NIL means no uses or more
@@ -323,6 +323,14 @@
 ;;; A COMPONENT structure provides a handle on a connected piece of
 ;;; the flow graph. Most of the passes in the compiler operate on
 ;;; COMPONENTs rather than on the entire flow graph.
+;;;
+;;; According to the CMU CL internals/front.tex, the reason for
+;;; separating compilation into COMPONENTs is
+;;;   to increase the efficiency of large block compilations. In
+;;;   addition to improving locality of reference and reducing the
+;;;   size of flow analysis problems, this allows back-end data
+;;;   structures to be reclaimed after the compilation of each
+;;;   component.
 (defstruct (component (:copier nil))
   ;; the kind of component
   ;;
@@ -488,7 +496,7 @@
 ;;; TNs, or eventually stack slots and registers). -- WHN 2001-09-29
 (defstruct (physenv (:copier nil))
   ;; the function that allocates this physical environment
-  (function (missing-arg) :type clambda)
+  (lambda (missing-arg) :type clambda :read-only t)
   #| ; seems not to be used as of sbcl-0.pre7.51
   ;; a list of all the lambdas that allocate variables in this
   ;; physical environment
@@ -508,7 +516,7 @@
   ;; some kind of info used by the back end
   (info nil))
 (defprinter (physenv :identity t)
-  function
+  lambda
   (closure :test closure)
   (nlx-info :test nlx-info))
 
@@ -914,6 +922,14 @@
   ;; (or one of its LETs) using a non-LET local call. This may include
   ;; deleted functions because nobody bothers to clear them out.
   (calls () :type list)
+  ;; a list of all the LAMBDA-VARs directly referred to from this
+  ;; function (or one of its LETs). This may include deleted variables
+  ;; because nobody bothers to clean them out.
+  ;;
+  ;; FIXME: This is completely analogous to the CALLS slot, except the
+  ;; elements here are LAMBDA-VARs instead of FUNCTIONALs. Maybe the
+  ;; two lists should be merged into a single list.
+  (refers-to-vars () :type list)
   ;; the TAIL-SET that this LAMBDA is in. This is null during creation.
   ;;
   ;; In CMU CL, and old SBCL, this was also NILed out when LET
@@ -1046,8 +1062,8 @@
 ;;; LAMBDA-VARs with no REFs are considered to be deleted; physical
 ;;; environment analysis isn't done on these variables, so the back
 ;;; end must check for and ignore unreferenced variables. Note that a
-;;; deleted lambda-var may have sets; in this case the back end is
-;;; still responsible for propagating the Set-Value to the set's Cont.
+;;; deleted LAMBDA-VAR may have sets; in this case the back end is
+;;; still responsible for propagating the SET-VALUE to the set's CONT.
 (def!struct (lambda-var (:include basic-var))
   ;; true if this variable has been declared IGNORE
   (ignorep nil :type boolean)