Store the selector, not the type encoding, in slots.

objc/slot.h

@@ -31,8 +31,8 @@ struct objc_slot
 	 * to the same object and sharing a cached slot then it may also improve
 	 * cache hits.  Profiling is probably required here. */
 	Class cachedFor;
-	/** The type encoding for the method identified by this slot. */
+	/** The (typed) selector for the method identified by this slot. */
-	const char *types;
+	SEL selector;
 	/** The current version.  This changes if the method changes or if a
 	 * subclass overrides this method, potentially invalidating this cache. */
 	int version;

runtime.c

@@ -302,7 +302,7 @@ Method class_getInstanceMethod(Class aClass, SEL aSelector)
 	if (NULL == slot) { return NULL; }
 
 	// Now find the typed variant of the selector, with the correct types.
-	aSelector = sel_registerTypedName_np(sel_getName(aSelector), slot->types);
+	aSelector = slot->selector;
 	
 	// Then do the slow lookup to find the method.
 	return class_getInstanceMethodNonrecursive(slot->owner, aSelector);

sendmsg2.c

@@ -12,7 +12,7 @@ void objc_send_initialize(id object);
 
 static id nil_method(id self, SEL _cmd) { return nil; }
 
-static struct objc_slot nil_slot = { Nil, Nil, "", 1, (IMP)nil_method };
+static struct objc_slot nil_slot = { Nil, Nil, 0, 1, (IMP)nil_method };
 
 typedef struct objc_slot *Slot_t;
 

slot_pool.h

@@ -10,7 +10,7 @@ static inline struct objc_slot *new_slot_for_method_in_class(Method method,
 {
 	struct objc_slot *slot = slot_pool_alloc();
 	slot->owner = class;
-	slot->types = method->types;
+	slot->selector = method->selector;
 	slot->method = method->imp;
 	slot->version = 1;
 	return slot;