disabled compiler flag hcc 4.0 for half support

Change-Id: I32175113f4c05d43310b3a05c2a14e12f6d48b09

include/hip/hcc_detail/hip_fp16.h

@@ -27,7 +27,16 @@ THE SOFTWARE.
 
 #define __CLANG_VERSION__ __clang_major__ * 10 + __clang_minor__
 
-#if __CLANG_VERSION__ == 35
+#ifdef HIP_HALF_HW_SUPPORT
+
+typedef __fp16 __half;
+extern "C" __half __hip_hadd_clang40_gfx803(__half a, __half b);
+
+__device__ inline __half __hadd(__half a, __half b){
+  return __hip_hadd_clang40_gfx803(a, b);
+}
+
+#else
 
 typedef struct{
   unsigned x: 16;
@@ -178,16 +187,5 @@ __device__ __half2 __lowhigh2highlow(const __half2 a);
 
 __device__ __half2 __low2half2(const __half2 a, const __half2 b);
 
-#endif
-
-#if __CLANG_VERSION__ == 40
-
-typedef __fp16 __half;
-extern "C" __half __hip_hadd_clang40_gfx803(__half a, __half b);
-
-__device__ inline __half __hadd(__half a, __half b){
-  return __hip_hadd_clang40_gfx803(a, b);
-}
-
 #endif
 #endif