Index: sys/sys/pctrie.h
===================================================================
--- sys/sys/pctrie.h
+++ sys/sys/pctrie.h
@@ -71,11 +71,14 @@
 static __inline struct type *						\
 name##_PCTRIE_VAL2PTR(uint64_t *val)					\
 {									\
+	struct type *ptr;						\
 									\
 	if (val == NULL)						\
 		return (NULL);						\
-	return (struct type *)						\
+	ptr = (struct type *)						\
 	    ((uintptr_t)val - __offsetof(struct type, field));		\
+	__builtin_assume(ptr != NULL);					\
+	return (ptr);							\
 }									\
 									\
 static __inline uint64_t *						\