Fix another variant of PR 7191. Also add a testcase

[oota-llvm.git] / cmake / modules / CheckAtomic.cmake

diff --git a/cmake/modules/CheckAtomic.cmake b/cmake/modules/CheckAtomic.cmake
index 27bbaba6998c99416a56a151ffd8cbf697216d17..f40ff4dfbd3123e4ab3fc29de1ddc3595eed1e43 100644 (file)
--- a/cmake/modules/CheckAtomic.cmake
+++ b/cmake/modules/CheckAtomic.cmake
@@ -1,14 +1,25 @@
 # atomic builtins are required for threading support.
 
 INCLUDE(CheckCXXSourceCompiles)
-       
+
 CHECK_CXX_SOURCE_COMPILES("
+#ifdef _MSC_VER
+#include <windows.h>
+#endif
 int main() {
+#ifdef _MSC_VER
+        volatile LONG val = 1;
+        MemoryBarrier();
+        InterlockedCompareExchange(&val, 0, 1);
+        InterlockedIncrement(&val);
+        InterlockedDecrement(&val);
+#else
         volatile unsigned long val = 1;
         __sync_synchronize();
         __sync_val_compare_and_swap(&val, 1, 0);
         __sync_add_and_fetch(&val, 1);
         __sync_sub_and_fetch(&val, 1);
+#endif
         return 0;
       }
 " LLVM_MULTITHREADED)