Provide optimised bn_clzw() for aarch64.

1 files changed, 15 insertions, 1 deletions

diff --git a/src/lib/libcrypto/bn/arch/aarch64/bn_arch.h b/src/lib/libcrypto/bn/arch/aarch64/bn_arch.h
index aa780e09e9..66de3682d4 100644
--- a/src/lib/libcrypto/bn/arch/aarch64/bn_arch.h
+++ b/src/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