1 files changed, 6 insertions, 0 deletions

diff --git a/contrib/llvm/lib/Support/Threading.cpp b/contrib/llvm/lib/Support/Threading.cpp
index ca7f3f64aa37..e8f5622d0e5c 100644
--- a/contrib/llvm/lib/Support/Threading.cpp
+++ b/contrib/llvm/lib/Support/Threading.cpp
@@ -16,6 +16,7 @@
 #include "llvm/Config/config.h"
 #include "llvm/Support/Atomic.h"
 #include "llvm/Support/Mutex.h"
+#include "llvm/Support/thread.h"
 #include <cassert>
 
 using namespace llvm;
@@ -71,6 +72,11 @@ void llvm::llvm_execute_on_thread(void (*Fn)(void*), void *UserData,
 #include "Windows/WindowsSupport.h"
 #include <process.h>
 
+// Windows will at times define MemoryFence.
+#ifdef MemoryFence
+#undef MemoryFence
+#endif
+
 struct ThreadInfo {
   void (*func)(void*);
   void *param;