From c123129b95cada301c3b3e173877cf05263db2fb Mon Sep 17 00:00:00 2001
From: Slava Pestov <slava@slava-pestovs-macbook-pro.local>
Date: Sat, 10 May 2008 00:42:26 -0500
Subject: [PATCH] Faster GC

---
 vm/data_gc.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++--
 vm/layouts.h |  2 +-
 2 files changed, 54 insertions(+), 3 deletions(-)

diff --git a/vm/data_gc.c b/vm/data_gc.c
index 6e32e14991..a52f2490e9 100755
--- a/vm/data_gc.c
+++ b/vm/data_gc.c
@@ -648,12 +648,63 @@ void do_code_slots(CELL scan)
 	}
 }
 
+/* This function is performance-critical */
 CELL collect_next(CELL scan)
 {
-	do_slots(scan,copy_handle);
+	CELL *obj = (CELL *)scan;
+	CELL *end = (CELL *)(scan + binary_payload_start(scan));
+
+	obj++;
+
+	CELL newspace_start = newspace->start;
+	CELL newspace_end = newspace->end;
+
+	if(HAVE_NURSERY_P && collecting_gen == NURSERY)
+	{
+		CELL nursery_start = nursery.start;
+		CELL nursery_end = nursery.end;
+
+		for(; obj < end; obj++)
+		{
+			CELL pointer = *obj;
+
+			if(!immediate_p(pointer)
+				&& (pointer >= nursery_start && pointer < nursery_end))
+				*obj = copy_object(pointer);
+		}
+	}
+	else if(HAVE_AGING_P && collecting_gen == AGING)
+	{
+		F_ZONE *tenured = &data_heap->generations[TENURED];
+
+		CELL tenured_start = tenured->start;
+		CELL tenured_end = tenured->end;
+
+		for(; obj < end; obj++)
+		{
+			CELL pointer = *obj;
+
+			if(!immediate_p(pointer)
+				&& !(pointer >= newspace_start && pointer < newspace_end)
+				&& !(pointer >= tenured_start && pointer < tenured_end))
+				*obj = copy_object(pointer);
+		}
+	}
+	else if(collecting_gen == TENURED)
+	{
+		for(; obj < end; obj++)
+		{
+			CELL pointer = *obj;
+
+			if(!immediate_p(pointer)
+				&& !(pointer >= newspace_start && pointer < newspace_end))
+				*obj = copy_object(pointer);
+		}
 
-	if(collecting_gen == TENURED)
 		do_code_slots(scan);
+	}
+	else
+		critical_error("Bug in collect_next",0);
 
 	return scan + untagged_object_size(scan);
 }
diff --git a/vm/layouts.h b/vm/layouts.h
index ff938309e7..89af0a306c 100755
--- a/vm/layouts.h
+++ b/vm/layouts.h
@@ -64,7 +64,7 @@ typedef signed long long s64;
 
 INLINE bool immediate_p(CELL obj)
 {
-	return (TAG(obj) == FIXNUM_TYPE || obj == F);
+	return (obj == F || TAG(obj) == FIXNUM_TYPE);
 }
 
 INLINE F_FIXNUM untag_fixnum_fast(CELL tagged)