Refine isnan builtin.

Signed-off-by: Yang Rong <rong.r.yang@intel.com>
Reviewed-by: Zhigang Gong <zhigang.gong@intel.com>

diff --git a/backend/src/ocl_stdlib.tmpl.h b/backend/src/ocl_stdlib.tmpl.h
index 555c63c..851a9aa 100644 (file)
--- a/backend/src/ocl_stdlib.tmpl.h
+++ b/backend/src/ocl_stdlib.tmpl.h
@@ -248,9 +248,7 @@ INLINE_OVERLOADABLE int isinf(float x) {
   return (u.u & 0x7FFFFFFF) == 0x7F800000;
 }
 INLINE_OVERLOADABLE int isnan(float x) {
-  union { uint u; float f; } u;
-  u.f = x;
-  return (u.u & 0x7FFFFFFF) > 0x7F800000;
+  return x != x;
 }
 INLINE_OVERLOADABLE int isnormal(float x) {
   union { uint u; float f; } u;