Updates OSS Eigen version to get bug fix for negative arguments to sqrt.

Adds unit tests for handling negative arguments to tf.sqrt.
Followup to cl/135111959.
Change: 136665526

tensorflow/python/kernel_tests/cwise_ops_test.py

@@ -1738,6 +1738,25 @@ class IsFiniteInfNanTest(tf.test.TestCase):
   def testDouble(self):
     self._testDtype(np.float64)
 
+  def testSqrt(self):
+    for dtype in [np.float16, np.float32, np.float64]:
+      fi = np.finfo(dtype)
+      for size in [1, 3, 4, 7, 8, 63, 64, 65]:
+        # For float32 Eigen uses Carmack's fast vectorized sqrt algorithm.
+        # It is not accurate for very large arguments, so we test for
+        # fi.max/100 instead of fi.max here.
+        for value in [fi.min, -2, -1, 0, fi.tiny, 1, 2, 1000, fi.max/100]:
+          x = np.full((size,), value, dtype=dtype)
+          np_y = np.sqrt(x)
+          np_nan = np.isnan(np_y)
+          with self.test_session(use_gpu=True):
+            tf_y = tf.sqrt(x)
+            tf_nan = tf.is_nan(tf_y)
+            if value < 0:
+              self.assertAllEqual(np_nan, tf_nan.eval())
+            else:
+              self.assertAllCloseAccordingToType(np_y, tf_y.eval())
+
 
 class RoundingTest(tf.test.TestCase):
 

tensorflow/workspace.bzl

@@ -14,8 +14,8 @@ def tf_workspace(path_prefix = "", tf_repo_name = ""):
   # These lines need to be changed when updating Eigen. They are parsed from
   # this file by the cmake and make builds to determine the eigen version and
   # hash.
-  eigen_version = "f6508f52a798"
-  eigen_sha256 = "9824d3beea839455e496ea472e4dcf05f7e25ec01dfb68e540fbfe522b609f72"
+  eigen_version = "1c7159a65db4"
+  eigen_sha256 = "b089a6eae493c32703c6beb5fdae9d64a7667c3a5440bae00ac8e517cc822e62"
 
   native.new_http_archive(
     name = "eigen_archive",