From 7aa052b9ed5b31966692c38a17af20c28e5206ac Mon Sep 17 00:00:00 2001
From: jsing <jsing@openbsd.org>
Date: Wed, 21 Jun 2023 07:56:43 +0000
Subject: [PATCH] Provide optimised bn_clzw() for aarch64.

---
 lib/libcrypto/bn/arch/aarch64/bn_arch.h | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/lib/libcrypto/bn/arch/aarch64/bn_arch.h b/lib/libcrypto/bn/arch/aarch64/bn_arch.h
index aa780e09e91..66de3682d4c 100644
--- a/lib/libcrypto/bn/arch/aarch64/bn_arch.h
+++ b/lib/libcrypto/bn/arch/aarch64/bn_arch.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: bn_arch.h,v 1.11 2023/06/17 15:40:46 jsing Exp $ */
+/*	$OpenBSD: bn_arch.h,v 1.12 2023/06/21 07:56:43 jsing Exp $ */
 /*
  * Copyright (c) 2023 Joel Sing <jsing@openbsd.org>
  *
@@ -24,6 +24,20 @@
 
 #if defined(__GNUC__)
 
+#define HAVE_BN_CLZW
+
+static inline int
+bn_clzw(BN_ULONG w)
+{
+	BN_ULONG n;
+
+	__asm__ ("clz   %[n], %[w]"
+	    : [n]"=r"(n)
+	    : [w]"r"(w));
+
+	return n;
+}
+
 #define HAVE_BN_ADDW
 
 static inline void
-- 
2.20.1