Improved the performance of tensor contractions and spatial convolutions on CPU:
 * Move some checks out of inner loops
 * Split the mapper in 2: a base mapper, and a sub-mapper. This reduces the number of variables that are contained in the base mapper and helps reduce register spills
Change: 112809881
diff --git a/WORKSPACE b/WORKSPACE
index 0abb8ac..c26bb52 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -21,8 +21,8 @@
 
 new_http_archive(
   name = "eigen_archive",
-  url = "https://bitbucket.org/eigen/eigen/get/d861b41.tar.gz",
-  sha256 = "8a22dd6597243592a6cb9e5aaed3c16b94848f0f6742312c45e3bbb35d33935d",
+  url = "https://bitbucket.org/eigen/eigen/get/fb2fa05.tar.gz",
+  sha256 = "8aacd8065d52528af1a22d6b72925dbb6b9fb8f25e46769481dd06d3edf63bbd",
   build_file = "eigen.BUILD",
 )