Ensure that newspace is the space in front when dumping an image the

prevent relocation on startup.

scheme/vm/heap.scm

@@ -59,6 +59,9 @@
   (swap! *newspace-begin* *oldspace-begin*)
   (swap! *newspace-end*   *oldspace-end*))
 
+(define (s48-newspace<oldspace?)
+  (address< s48-*limit* *oldspace-limit*))
+
 ;----------------
 
 (define (s48-available? cells)

scheme/vm/interfaces.scm

@@ -135,6 +135,7 @@
 (define-interface heap-interface
   (export s48-available
 	  s48-heap-size
+	  s48-newspace<oldspace?
 
 	  s48-find-all
 	  s48-find-all-records

scheme/vm/no-gc-package-defs.scm

@@ -19,6 +19,8 @@
 (define-structure heap heap-interface
   (open prescheme)
   (begin
+    (define s48-newspace<oldspace?
+      (external "s48_newspaceLoldspaceP" (=> () boolean)))
     (define s48-available
       (external "s48_available" (=> () integer)))
     (define s48-heap-size

scheme/vm/package-defs.scm

@@ -83,7 +83,7 @@
 	interpreter-internal
 	channel-io vmio
 	memory data struct
-	images interpreter-gc
+	images interpreter-gc heap
 	symbols external-opcodes
 	stack			;pop
 	stob)			;immutable

scheme/vm/prim-io.scm

@@ -414,6 +414,16 @@
 		(let ((status (write-string (extract-string comment-string) port)))
 		  (if (error? status)
 		      (port-lose (enum exception os-error) status port)
+		      ;; little hack for faster startup:
+		      ;; trigger a GC to ensure newspace is behind oldspace
+		      ;; write-image will also GC and thereby move newspace 
+		      ;; to the front. 
+		      ;; We can't do this in s48-write-image because it doesn't 
+		      ;; know collect-saving-temp.
+		      (let ((resume-proc
+			     (if (s48-newspace<oldspace?)
+				 (collect-saving-temp resume-proc)
+				 resume-proc)))
 			(let ((status (s48-write-image resume-proc port)))
 			  (if (error? status)
 			      (port-lose (enum exception os-error) status port)
@@ -430,7 +440,7 @@
 				      resume-proc
 				      comment-string
 				      undumpables
-				      (enter-fixnum undumpable-count))))))))))))))))
+				      (enter-fixnum undumpable-count)))))))))))))))))
 
 ; READ-IMAGE needs to protect some values against GCs (this can't be with
 ; READ-IMAGE as that is compiled separately.)