From 3491881522a4eafafea8acf8113f99468ead735c Mon Sep 17 00:00:00 2001
From: Yao Zhang <yaozhang@google.com>
Date: Mon, 11 Sep 2017 14:41:31 -0700
Subject: [PATCH] Enable fused batch norm, which is 15-20% faster for training
 and inference.

PiperOrigin-RevId: 168288154
---
 tensorflow/contrib/layers/python/layers/layers.py | 7 +------
 tensorflow/python/layers/normalization.py         | 8 +-------
 2 files changed, 2 insertions(+), 13 deletions(-)

diff --git a/tensorflow/contrib/layers/python/layers/layers.py b/tensorflow/contrib/layers/python/layers/layers.py
index 36421f86587..33c31262664 100644
--- a/tensorflow/contrib/layers/python/layers/layers.py
+++ b/tensorflow/contrib/layers/python/layers/layers.py
@@ -22,7 +22,6 @@ from __future__ import division
 from __future__ import print_function
 
 import functools
-import os
 import six
 
 from tensorflow.contrib.framework.python.ops import add_arg_scope
@@ -98,8 +97,6 @@ DATA_FORMAT_NCHW = 'NCHW'
 DATA_FORMAT_NHWC = 'NHWC'
 DATA_FORMAT_NCDHW = 'NCDHW'
 DATA_FORMAT_NDHWC = 'NDHWC'
-_FUSED_DEFAULT = os.getenv('TF_DEFAULT_USES_FUSED_BATCH_NORM',
-                           '').lower() in ('true', 't', '1')
 
 
 @add_arg_scope
@@ -549,10 +546,8 @@ def batch_norm(inputs,
     ValueError: If the rank of `inputs` is undefined.
     ValueError: If rank or channels dimension of `inputs` is undefined.
   """
-  # This environment variable is only used during the testing period of fused
-  # batch norm and will be removed after that.
   if fused is None:
-    fused = _FUSED_DEFAULT
+    fused = True
 
   # Only use _fused_batch_norm if all of the following three
   # conditions are true:
diff --git a/tensorflow/python/layers/normalization.py b/tensorflow/python/layers/normalization.py
index 62265dce3c5..222817cd3a3 100644
--- a/tensorflow/python/layers/normalization.py
+++ b/tensorflow/python/layers/normalization.py
@@ -20,7 +20,6 @@ from __future__ import absolute_import
 from __future__ import division
 from __future__ import print_function
 
-import os
 import six
 from six.moves import xrange  # pylint: disable=redefined-builtin
 import numpy as np
@@ -46,9 +45,6 @@ from tensorflow.python.ops import variables
 from tensorflow.python.layers import base
 from tensorflow.python.layers import utils
 
-_FUSED_DEFAULT = os.getenv('TF_DEFAULT_USES_FUSED_BATCH_NORM',
-                           '').lower() in ('true', 't', '1')
-
 
 class BatchNormalization(base.Layer):
   """Batch Normalization layer from http://arxiv.org/abs/1502.03167.
@@ -140,10 +136,8 @@ class BatchNormalization(base.Layer):
     self.beta_constraint = beta_constraint
     self.gamma_constraint = gamma_constraint
     self.renorm = renorm
-    # This environment variable is only used during the testing period of fused
-    # batch norm and will be removed after that.
     if fused is None:
-      fused = _FUSED_DEFAULT
+      fused = True
 
     self.fused = fused
     self._bessels_correction_test_only = True