From 888b7b5dcea20a3f7a4753ad982925860684521c Mon Sep 17 00:00:00 2001
From: Jonathan G Rennison <j.g.rennison@gmail.com>
Date: Thu, 18 Jan 2024 01:11:10 +0000
Subject: [PATCH] Add a simple 64 bit to 64 bit hash (from MurmurHash3)

---
 src/core/hash_func.hpp | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/core/hash_func.hpp b/src/core/hash_func.hpp
index 28d09ad46e..eb35ea4382 100644
--- a/src/core/hash_func.hpp
+++ b/src/core/hash_func.hpp
@@ -25,4 +25,19 @@ inline uint32_t SimpleHash32(uint32_t h)
 	return h;
 }
 
+/**
+ * Simple 64 bit to 64 bit hash
+ * From MurmurHash3
+ */
+inline uint64_t SimpleHash64(uint64_t h)
+{
+	h ^= h >> 33;
+	h *= 0xff51afd7ed558ccdULL;
+	h ^= h >> 33;
+	h *= 0xc4ceb9fe1a85ec53ULL;
+	h ^= h >> 33;
+
+	return h;
+}
+
 #endif /* HASH_FUNC_HPP */