From 3e9a8d9fcdffa7617175d76e2642e0150acfe488 Mon Sep 17 00:00:00 2001
From: Edward Diener <eldlistmailingz@tropicsoft.com>
Date: Fri, 17 Apr 2020 05:49:29 -0400
Subject: [PATCH] Atomic exchange for 16 bytes does not work for Embarcadero
 C++ clang-based compilers.

---
 include/boost/config/compiler/codegear.hpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/include/boost/config/compiler/codegear.hpp b/include/boost/config/compiler/codegear.hpp
index bdb43f03..3fdaa97a 100644
--- a/include/boost/config/compiler/codegear.hpp
+++ b/include/boost/config/compiler/codegear.hpp
@@ -35,6 +35,10 @@
 #undef BOOST_HAS_FLOAT128
 #endif
 
+// The clang-based compilers can not do 128 atomic exchanges
+
+#define BOOST_ATOMIC_NO_CMPXCHG16B
+
 // 32 functions are missing from the current RTL in cwchar, so it really can not be used even if it exists
 
 #  define BOOST_NO_CWCHAR