From b557a84123a0bc9dec4dc3178301fd9a67a6c709 Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Fri, 23 Jun 2023 15:31:54 -0600
Subject: [PATCH] [algs] Speed up fasthash for aligned uint64_t

---
 src/hb-algs.hh | 26 ++++++++++++++++++++++----
 1 file changed, 22 insertions(+), 4 deletions(-)

diff --git a/src/hb-algs.hh b/src/hb-algs.hh
index 86414866f..c8a3a216d 100644
--- a/src/hb-algs.hh
+++ b/src/hb-algs.hh
@@ -297,10 +297,28 @@ static inline uint64_t fasthash64(const void *buf, size_t len, uint64_t seed)
 	uint64_t h = seed ^ (len * m);
 	uint64_t v;
 
-	while (pos != end) {
-		v  = pos++->v;
-		h ^= mix(v);
-		h *= m;
+#ifndef HB_OPTIMIZE_SIZE
+	if (((uintptr_t) pos & 7) == 0)
+	{
+	  while (pos != end)
+	  {
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wcast-align"
+	    v  = * (const uint64_t *) (pos++);
+#pragma GCC diagnostic pop
+	    h ^= mix(v);
+	    h *= m;
+	  }
+	}
+	else
+#endif
+	{
+	  while (pos != end)
+	  {
+	    v  = pos++->v;
+	    h ^= mix(v);
+	    h *= m;
+	  }
 	}
 
 	pos2 = (const unsigned char*)pos;