Update documentation

include/mxnet/c_api.h

@@ -274,6 +274,9 @@ MXNET_DLL int MXRandomSeedContext(int seed, int dev_type, int dev_id);
 
 /*!
  * \brief Change floating-point calculations when dealing with denormalized values.
+ * Currently this option is only supported in CPU backend.
+ * Flushing denormalized values to zero is enabled by default.
+ *
  * \param value state of flush-to-zero and denormals-are-zero to set.
  * \param prev_state state of flush-to-zero and denormals-are-zero before setting new state.
  * \return 0 when success, -1 when failure happens.

python/mxnet/util.py

@@ -1208,11 +1208,17 @@ def set_flush_denorms(value):
        (exponent is the smallest possible value).
        Flushing denormalized values to 0 can speedup calculations if such values occurs,
        but if fulfilling whole IEEE 754 standard is required this option should be disabled.
+       Flushing denormalized values is enabled in MXNet by default.
 
     Parameters
     ----------
     value : bool
         State of flush-to-zero and denormals-are-zero in MXCSR register
+
+    Returns
+    -------
+    prev_state : bool
+        Previous state of flush-to-zero in MXCSR register
     """
     ret = ctypes.c_bool()
     passed_value = ctypes.c_bool(value)