From ca5ffc07433103273357059f39b9a3cf13711d4f Mon Sep 17 00:00:00 2001
From: Sean Parkinson <sean@wolfssl.com>
Date: Thu, 19 Nov 2020 09:44:58 +1000
Subject: [PATCH] AESNI compile flags: clang can't have -msse4

Setting the SSE4 architecture with clang creates executables that can't
run on old machines.
---
 configure.ac | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/configure.ac b/configure.ac
index 8f277be6f..db1ddd4b1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1383,11 +1383,18 @@ then
         AM_CFLAGS="$AM_CFLAGS -DWOLFSSL_AESNI"
         if test "$GCC" = "yes"
         then
-            # GCC needs these flags, icc doesn't
-            # opt levels greater than 2 may cause problems on systems w/o aesni
-            if test "$CC" != "icc"
+            # clang needs these flags
+            if test "$CC" = "clang"
             then
-                AM_CFLAGS="$AM_CFLAGS -maes -msse4 -mpclmul"
+                AM_CFLAGS="$AM_CFLAGS -maes -mpclmul"
+            else
+                # GCC needs these flags, icc doesn't
+                # opt levels greater than 2 may cause problems on systems w/o
+                # aesni
+                if test "$CC" != "icc"
+                then
+                    AM_CFLAGS="$AM_CFLAGS -maes -msse4 -mpclmul"
+                fi
             fi
         fi
         AS_IF([test "x$ENABLED_AESGCM" != "xno"],[AM_CCASFLAGS="$AM_CCASFLAGS -DHAVE_AESGCM"])