diff --git a/API b/API
index a65c0be3..0b0cd551 100644
--- a/API
+++ b/API
@@ -88,7 +88,7 @@ follows.
 	unsigned total = sel_copyTypes_np("alloc", types, total);
 	if (total > 16)
 	{
-		types = calloc(sizeof(char*), total);
+		types = calloc(total, sizeof(char*));
 		sel_copyTypes_np("alloc", types, total);
 	}
 	// Do stuff with the types.
diff --git a/Test/BoxedForeignException.m b/Test/BoxedForeignException.m
index 7ef5863b..1505d727 100644
--- a/Test/BoxedForeignException.m
+++ b/Test/BoxedForeignException.m
@@ -16,7 +16,7 @@
 
 int throw(void)
 {
-	struct foreign_exception *foreign_exception = calloc(sizeof(struct foreign_exception), 1);
+	struct foreign_exception *foreign_exception = calloc(1, sizeof(struct foreign_exception));
 	foreign_exception->header.exception_class = 42;
 	foreign_exception->x = 12;
 	_Unwind_RaiseException(&foreign_exception->header);
diff --git a/arc.mm b/arc.mm
index fbba14c0..502ab450 100644
--- a/arc.mm
+++ b/arc.mm
@@ -134,7 +134,7 @@ - (void)release;
 template<typename T>
 static inline T* new_zeroed()
 {
-	return static_cast<T*>(calloc(sizeof(T), 1));
+	return static_cast<T*>(calloc(1, sizeof(T)));
 }
 
 static inline struct arc_tls* getARCThreadData(void)
@@ -737,7 +737,7 @@ void deallocate(T* p, std::size_t)
   * exists.
   */
 __attribute__((always_inline))
-static BOOL loadWeakPointer(id *addr, id *obj, WeakRef **ref)
+static inline BOOL loadWeakPointer(id *addr, id *obj, WeakRef **ref)
 {
 	id oldObj = *addr;
 	if (oldObj == nil)
@@ -779,40 +779,37 @@ static BOOL setObjectHasWeakRefs(id obj)
 	if (obj && cls && objc_test_class_flag(cls, objc_class_flag_fast_arc))
 	{
 		uintptr_t *refCount = ((uintptr_t*)obj) - 1;
-		if (obj)
-		{
-			uintptr_t refCountVal = __sync_fetch_and_add(refCount, 0);
-			uintptr_t newVal = refCountVal;
-			do {
-				refCountVal = newVal;
-				size_t realCount = refCountVal & refcount_mask;
-				// If this object has already been deallocated (or is in the
-				// process of being deallocated) then don't bother storing it.
-				if (realCount == refcount_mask)
-				{
-					obj = nil;
-					cls = Nil;
-					break;
-				}
-				// The weak ref flag is monotonic (it is set, never cleared) so
-				// don't bother trying to re-set it.
-				if ((refCountVal & weak_mask) == weak_mask)
-				{
-					break;
-				}
-				// Set the flag in the reference count to indicate that a weak
-				// reference has been taken.
-				//
-				// We currently hold the weak ref lock, so another thread
-				// racing to deallocate this object will have to wait to do so
-				// if we manage to do the reference count update first.  This
-				// shouldn't be possible, because `obj` should be a strong
-				// reference and so it shouldn't be possible to deallocate it
-				// while we're assigning it.
-				uintptr_t updated = ((uintptr_t)realCount | weak_mask);
-				newVal = __sync_val_compare_and_swap(refCount, refCountVal, updated);
-			} while (newVal != refCountVal);
-		}
+		uintptr_t refCountVal = __sync_fetch_and_add(refCount, 0);
+		uintptr_t newVal = refCountVal;
+		do {
+			refCountVal = newVal;
+			size_t realCount = refCountVal & refcount_mask;
+			// If this object has already been deallocated (or is in the
+			// process of being deallocated) then don't bother storing it.
+			if (realCount == refcount_mask)
+			{
+				obj = nil;
+				cls = Nil;
+				break;
+			}
+			// The weak ref flag is monotonic (it is set, never cleared) so
+			// don't bother trying to re-set it.
+			if ((refCountVal & weak_mask) == weak_mask)
+			{
+				break;
+			}
+			// Set the flag in the reference count to indicate that a weak
+			// reference has been taken.
+			//
+			// We currently hold the weak ref lock, so another thread
+			// racing to deallocate this object will have to wait to do so
+			// if we manage to do the reference count update first.  This
+			// shouldn't be possible, because `obj` should be a strong
+			// reference and so it shouldn't be possible to deallocate it
+			// while we're assigning it.
+			uintptr_t updated = ((uintptr_t)realCount | weak_mask);
+			newVal = __sync_val_compare_and_swap(refCount, refCountVal, updated);
+		} while (newVal != refCountVal);
 	}
 	return isGlobalObject;
 }
diff --git a/class_table.c b/class_table.c
index 128af53e..4d5e6c47 100644
--- a/class_table.c
+++ b/class_table.c
@@ -525,7 +525,7 @@ int objc_getClassList(Class *buffer, int bufferLen)
 Class *objc_copyClassList(unsigned int *outCount)
 {
 	int count = class_table->table_used;
-	Class *buffer = calloc(sizeof(Class), count);
+	Class *buffer = calloc(count, sizeof(Class));
 	if (NULL != outCount)
 	{
 		*outCount = count;
diff --git a/dtable.c b/dtable.c
index a2cdc08c..fb7b1bd7 100644
--- a/dtable.c
+++ b/dtable.c
@@ -655,11 +655,6 @@ PRIVATE void objc_resize_dtables(uint32_t newSize)
 	}
 }
 
-PRIVATE dtable_t objc_copy_dtable_for_class(dtable_t old, Class cls)
-{
-	return SparseArrayCopy(old);
-}
-
 PRIVATE void free_dtable(dtable_t dtable)
 {
 	SparseArrayDestroy(dtable);
diff --git a/gc_none.c b/gc_none.c
index f263f37b..3f95348f 100644
--- a/gc_none.c
+++ b/gc_none.c
@@ -16,7 +16,7 @@ static id allocate_class(Class cls, size_t extraBytes)
 		_aligned_malloc(size, 32);
 	memset(addr, 0, size);
 #else
-		calloc(size, 1);
+		calloc(1, size);
 #endif
 	return (id)(addr + 1);
 }
@@ -32,7 +32,7 @@ static void free_object(id obj)
 
 static void *alloc(size_t size)
 {
-	return calloc(size, 1);
+	return calloc(1, size);
 }
 
 void objc_registerThreadWithCollector(void) {}
diff --git a/legacy.c b/legacy.c
index 1ef1b810..61728e5d 100644
--- a/legacy.c
+++ b/legacy.c
@@ -146,7 +146,7 @@ static struct objc_method_list *upgradeMethodList(struct objc_method_list_gcc *o
 	{
 		return NULL;
 	}
-	struct objc_method_list *l = calloc(sizeof(struct objc_method_list) + old->count * sizeof(struct objc_method), 1);
+	struct objc_method_list *l = calloc(1, sizeof(struct objc_method_list) + old->count * sizeof(struct objc_method));
 	l->count = old->count;
 	if (old->next)
 	{
@@ -343,7 +343,7 @@ PRIVATE struct objc_class_gsv1* objc_legacy_class_for_class(Class cls)
 
 PRIVATE Class objc_upgrade_class(struct objc_class_gsv1 *oldClass)
 {
-	Class cls = calloc(sizeof(struct objc_class), 1);
+	Class cls = calloc(1, sizeof(struct objc_class));
 	cls->isa = oldClass->isa;
 	// super_class is left nil and we upgrade it later.
 	cls->name = oldClass->name;
diff --git a/properties.m b/properties.m
index 7c3dcc31..46b2e7f8 100644
--- a/properties.m
+++ b/properties.m
@@ -285,7 +285,7 @@ objc_property_t class_getProperty(Class cls, const char *name)
 	{
 		return NULL;
 	}
-	objc_property_t *list = calloc(sizeof(objc_property_t), count);
+	objc_property_t *list = calloc(count, sizeof(objc_property_t));
 	unsigned int out = 0;
 	for (struct objc_property_list *l=properties ; NULL!=l ; l=l->next)
 	{
@@ -423,7 +423,7 @@ objc_property_t class_getProperty(Class cls, const char *name)
 		}
 		count++;
 	}
-	objc_property_attribute_t *propAttrs = calloc(sizeof(objc_property_attribute_t), count);
+	objc_property_attribute_t *propAttrs = calloc(count, sizeof(objc_property_attribute_t));
 	memcpy(propAttrs, attrs, count * sizeof(objc_property_attribute_t));
 	if (NULL != outCount)
 	{
diff --git a/protocol.c b/protocol.c
index 2c2a9d5f..3028ea27 100644
--- a/protocol.c
+++ b/protocol.c
@@ -316,7 +316,7 @@ struct objc_method_description *protocol_copyMethodDescriptionList(Protocol *p,
 
 	*count = list->count;
 	struct objc_method_description *out =
-		calloc(sizeof(struct objc_method_description), list->count);
+		calloc(list->count, sizeof(struct objc_method_description));
 	for (int i=0 ; i < (list->count) ; i++)
 	{
 		out[i].name = protocol_method_at_index(list, i)->selector;
@@ -335,7 +335,7 @@ Protocol*__unsafe_unretained* protocol_copyProtocolList(Protocol *p, unsigned in
 	}
 
 	*count  = p->protocol_list->count;
-	Protocol **out = calloc(sizeof(Protocol*), p->protocol_list->count);
+	Protocol **out = calloc(p->protocol_list->count, sizeof(Protocol*));
 	for (int i=0 ; i<p->protocol_list->count ; i++)
 	{
 		out[i] = (Protocol*)p->protocol_list->list[i];
@@ -370,7 +370,7 @@ objc_property_t *protocol_copyPropertyList2(Protocol *p, unsigned int *outCount,
 	{
 		return NULL;
 	}
-	objc_property_t *list = calloc(sizeof(objc_property_t), count);
+	objc_property_t *list = calloc(count, sizeof(objc_property_t));
 	unsigned int out = 0;
 	for (struct objc_property_list *l=properties ; l!=NULL ; l=l->next)
 	{
@@ -506,7 +506,7 @@ Protocol*__unsafe_unretained* objc_copyProtocolList(unsigned int *outCount)
 {
 	LOCK_FOR_SCOPE(&protocol_table_lock);
 	unsigned int total = known_protocol_table->table_used;
-	Protocol **p = calloc(sizeof(Protocol*), known_protocol_table->table_used);
+	Protocol **p = calloc(known_protocol_table->table_used, sizeof(Protocol*));
 
 	struct protocol_table_enumerator *e = NULL;
 	Protocol *next;
diff --git a/sarray2.c b/sarray2.c
index 5f50f6d7..b356edee 100644
--- a/sarray2.c
+++ b/sarray2.c
@@ -183,7 +183,7 @@ PRIVATE void SparseArrayInsert(SparseArray * sarray, uint32_t index, void *value
 
 PRIVATE SparseArray *SparseArrayCopy(SparseArray * sarray)
 {
-	SparseArray *copy = calloc(sizeof(SparseArray), 1);
+	SparseArray *copy = calloc(1, sizeof(SparseArray));
 	memcpy(copy, sarray, sizeof(SparseArray));
 	copy->refCount = 1;
 	// If the sarray has children, increase their refcounts and link them