Index: llvm/trunk/cmake/config-ix.cmake
===================================================================
--- llvm/trunk/cmake/config-ix.cmake
+++ llvm/trunk/cmake/config-ix.cmake
@@ -17,7 +17,7 @@
 
 if( UNIX AND NOT (BEOS OR HAIKU) )
   # Used by check_symbol_exists:
-  set(CMAKE_REQUIRED_LIBRARIES m)
+  list(APPEND CMAKE_REQUIRED_LIBRARIES "m")
 endif()
 # x86_64 FreeBSD 9.2 requires libcxxrt to be specified explicitly.
 if( CMAKE_SYSTEM MATCHES "FreeBSD-9.2-RELEASE" AND
Index: llvm/trunk/cmake/modules/CheckAtomic.cmake
===================================================================
--- llvm/trunk/cmake/modules/CheckAtomic.cmake
+++ llvm/trunk/cmake/modules/CheckAtomic.cmake
@@ -8,7 +8,7 @@
 
 function(check_working_cxx_atomics varname)
   set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
-  set(CMAKE_REQUIRED_FLAGS "-std=c++11")
+  set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -std=c++11")
   CHECK_CXX_SOURCE_COMPILES("
 #include <atomic>
 std::atomic<int> x;
Index: llvm/trunk/cmake/modules/CheckCompilerVersion.cmake
===================================================================
--- llvm/trunk/cmake/modules/CheckCompilerVersion.cmake
+++ llvm/trunk/cmake/modules/CheckCompilerVersion.cmake
@@ -28,7 +28,7 @@
         # bug in libstdc++4.6 that is fixed in libstdc++4.7.
         set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
         set(OLD_CMAKE_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES})
-        set(CMAKE_REQUIRED_FLAGS "-std=c++0x")
+        set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -std=c++0x")
         check_cxx_source_compiles("
 #include <atomic>
 std::atomic<float> x(0.0f);