diff --git a/ChangeLog b/ChangeLog
index 0934788b7..b1bf7be5e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+Sun Oct 25 08:00:00 1998  Richard Frith-Macdonald <richard@brainstorm.co.uk>
+
+	src/NSObject.m: Cache implementation for adding object to autorelease
+	pool to avoid objc runtime messaging overhead.
+	src/NSAutoreleasePool.m: Cache implementation for adding object to
+	src/NSAutoreleasePool.m: Cache implementation for adding object to
+	autorelease pool to avoid objc runtime messaging overhead.
+	src/NSGCString.m: Implemented ([+allocWithZone:])
+	src/NSGString.m: Implemented ([+allocWithZone:])
+
 Sat Oct 24 11:30:00 1998  Richard Frith-Macdonald <richard@brainstorm.co.uk>
 
 	src/NSArchiver.m: New implementation
diff --git a/Source/NSGCString.m b/Source/NSGCString.m
index edced3b1c..e7ff46653 100644
--- a/Source/NSGCString.m
+++ b/Source/NSGCString.m
@@ -40,6 +40,11 @@
 
 @implementation NSGCString
 
++ allocWithZone: (NSZone*)z
+{
+  return NSAllocateObject (self, 0, z);
+}
+
 - (void)dealloc
 {
     if (_zone) {
@@ -479,6 +484,11 @@
 
 @implementation NSGMutableCString
 
++ allocWithZone: (NSZone*)z
+{
+  return NSAllocateObject (self, 0, z);
+}
+
 + (void) initialize
 {
   static int done = 0;
diff --git a/Source/NSGString.m b/Source/NSGString.m
index 771e8fc5f..c4d0522fe 100644
--- a/Source/NSGString.m
+++ b/Source/NSGString.m
@@ -48,6 +48,11 @@
 
 @implementation NSGString
 
++ allocWithZone: (NSZone*)z
+{
+  return NSAllocateObject (self, 0, z);
+}
+
 - (void)dealloc
 {
   if (_zone)
@@ -319,6 +324,11 @@
 
 // @protocol NSMutableString <NSString>
 
++ allocWithZone: (NSZone*)z
+{
+  return NSAllocateObject (self, 0, z);
+}
+
 + (void) initialize
 {
   static int done = 0;
diff --git a/Source/NSObject.m b/Source/NSObject.m
index ebaf45601..23dadab64 100644
--- a/Source/NSObject.m
+++ b/Source/NSObject.m
@@ -346,6 +346,8 @@ NSShouldRetainWithZone (NSObject *anObject, NSZone *requestedZone)
    need mutex protection, since it is simply a pointer that gets read
    and set. */
 static id autorelease_class = nil;
+static SEL autorelease_sel = @selector(addObject:);
+static IMP autorelease_imp = 0;
 
 /* When this is `YES', every call to release/autorelease, checks to
    make sure isn't being set up to release itself too many times.
@@ -367,6 +369,7 @@ static BOOL double_release_check_enabled = NO;
       retain_counts_gate = objc_mutex_allocate ();
 #endif
       autorelease_class = [NSAutoreleasePool class];
+      autorelease_imp = [autorelease_class methodForSelector: autorelease_sel];
       _fastBuildCache();
     }
   return;
@@ -594,7 +597,7 @@ static BOOL double_release_check_enabled = NO;
 	  @"%d release(s) versus %d retain(s)", release_count, retain_count];
     }
 
-  [autorelease_class addObject:self];
+  (*autorelease_imp)(autorelease_class, autorelease_sel, self);
   return self;
 }
 
@@ -921,6 +924,7 @@ static BOOL double_release_check_enabled = NO;
 + (void) setAutoreleaseClass: (Class)aClass
 {
   autorelease_class = aClass;
+  autorelease_imp = [self instanceMethodForSelector: autorelease_sel];
 }
 
 + (Class) autoreleaseClass