Unrolled loop in NODES-LINKED?

diff --git a/v8/src/compiler/midend/dataflow.scm b/v8/src/compiler/midend/dataflow.scm
index 94ea0032e523a73374b20c230d5b209bcd9985fd..61d6cb20ec52f9879cdcb6d25cfbd2d97d68a1d1 100644 (file)
--- a/v8/src/compiler/midend/dataflow.scm
+++ b/v8/src/compiler/midend/dataflow.scm
@@ -1,6 +1,6 @@
 #| -*-Scheme-*-
 
-$Id: dataflow.scm,v 1.11 1995/03/22 01:06:49 adams Exp $
+$Id: dataflow.scm,v 1.12 1995/04/08 21:00:17 adams Exp $
 
 Copyright (c) 1994 Massachusetts Institute of Technology
 
@@ -2122,6 +2122,29 @@ MIT in each case. |#
                        (eq? from (vector-ref set (fix:- i 1)))
                        (loop (fix:- i 2)))))))))
 
+(define (nodes-linked? from to)
+  (or (eq? from to)
+      (let ((set  (node/links-in to)))
+       (and set
+            (let unrolled-loop ((i  (vector-ref set 0)))
+              (if (fix:>= i 8)
+                  (or (eq? from (vector-ref set i))
+                      (eq? from (vector-ref set (fix:- i 1)))
+                      (eq? from (vector-ref set (fix:- i 2)))
+                      (eq? from (vector-ref set (fix:- i 3)))
+                      (eq? from (vector-ref set (fix:- i 4)))
+                      (eq? from (vector-ref set (fix:- i 5)))
+                      (eq? from (vector-ref set (fix:- i 6)))
+                      (eq? from (vector-ref set (fix:- i 7)))
+                      (unrolled-loop (fix:- i 8)))
+                  (let end-loop ((i i))
+                    (and (fix:> i 0)
+                         ;; Loop unrolled 1 time is safe because the zero slot
+                         ;; contains a fixnum that will never match a node
+                         (or (eq? from (vector-ref set i))
+                             (eq? from (vector-ref set (fix:- i 1)))
+                             (end-loop (fix:- i 2)))))))))))
+
 
 (define (make-empty-node-set)
   '#F)