[Intel MKL] Fixing bfloat16 build failure in MklRelu
diff --git a/tensorflow/core/kernels/mkl_relu_op.cc b/tensorflow/core/kernels/mkl_relu_op.cc
index 5d52742..126ca4c 100644
--- a/tensorflow/core/kernels/mkl_relu_op.cc
+++ b/tensorflow/core/kernels/mkl_relu_op.cc
@@ -19,7 +19,6 @@
 #include <unordered_map>
 
 #include "mkldnn.hpp"
-#include "third_party/eigen3/unsupported/Eigen/CXX11/Tensor"
 #include "tensorflow/core/framework/numeric_op.h"
 #include "tensorflow/core/framework/op_kernel.h"
 #include "tensorflow/core/framework/register_types.h"
@@ -27,6 +26,7 @@
 #include "tensorflow/core/lib/core/errors.h"
 #include "tensorflow/core/util/mkl_types.h"
 #include "tensorflow/core/util/mkl_util.h"
+#include "third_party/eigen3/unsupported/Eigen/CXX11/Tensor"
 
 using mkldnn::algorithm;
 using mkldnn::eltwise_forward;
@@ -924,7 +924,7 @@
     // return exp(feature) - 1 if feature > 0; feature otherwise
     T feature = (static_cast<T*>(user_i))[0];
     if (feature < static_cast<T>(0))
-      (static_cast<T*>(out_o))[0] = std::exp(feature);
+      (static_cast<T*>(out_o))[0] = Eigen::numext::exp(feature);
     else
       (static_cast<T*>(out_o))[0] = feature;
     return;
@@ -966,7 +966,7 @@
     if (feature > static_cast<T>(0)) {
       (static_cast<T*>(out_o))[0] = (static_cast<T*>(user_g))[0];
     } else {
-      T elu = std::exp(feature) - static_cast<T>(1);
+      T elu = Eigen::numext::exp(feature) - static_cast<T>(1);
       (static_cast<T*>(out_o))[0] =
           (static_cast<T*>(user_g))[0] * (elu + static_cast<T>(1));
     }
@@ -1004,8 +1004,8 @@
     void* out_o = static_cast<void*>(dst_tensor->flat<T>().data());
     // tanh(x) = (e^x - e^(-x))/ (e^x + e^(-x))
     T feature = (static_cast<T*>(user_i))[0];
-    T e1 = std::exp(feature);
-    T e2 = std::exp(-feature);
+    T e1 = Eigen::numext::exp(feature);
+    T e2 = Eigen::numext::exp(-feature);
     (static_cast<T*>(out_o))[0] = (e1 - e2) / (e1 + e2);
     return;
   }