1 files changed, 8 insertions, 0 deletions
diff --git a/kernel/hashmap.h b/kernel/hashmap.h
index 729b4916c..431e8122e 100644
--- a/kernel/hashmap.h
+++ b/kernel/hashmap.h
@@ -25,10 +25,18 @@
 
 #define YOSYS_HASHTABLE_SIZE_FACTOR 3
 
+// The XOR version of DJB2
+// (traditionally 5381 is used as starting value for the djb2 hash)
 inline unsigned int mkhash(unsigned int a, unsigned int b) {
 	return ((a << 5) + a) ^ b;
 }
 
+// The ADD version of DJB2
+// (use this version as last call for cache locality in b)
+inline unsigned int mkhash_add(unsigned int a, unsigned int b) {
+	return ((a << 5) + a) + b;
+}
+
 template<typename T> struct hash_ops {
 	bool cmp(const T &a, const T &b) const {
 		return a == b;