diff --git a/thiersort.h b/thiersort.h
index 8caceb0..d3f7a85 100644
--- a/thiersort.h
+++ b/thiersort.h
@@ -451,6 +451,7 @@ static inline void thiersort8_internal(
 #ifdef TS_SSE2
 	// TODO: implement with SSE2
 #else
+	/* TODO: We can go both down and upwards here to increase ILP! */
 	/* Occurence counting O(n) */
 	for(TSU32 i = 0; i < length; ++i) {
 		++radics[ts_radixi(arr[i].key, isint, isunsigned, isfloat)];