Merged in mfigurnov/eigen (pull request PR-400)

Exponentially scaled modified Bessel functions of order zero and one.

Approved-by: Benoit Steiner <benoit.steiner.goog@gmail.com>

CMakeLists.txt

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5245b29..91545bd 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -41,10 +41,13 @@
 set(EIGEN_MINOR_VERSION "${CMAKE_MATCH_1}")
 set(EIGEN_VERSION_NUMBER ${EIGEN_WORLD_VERSION}.${EIGEN_MAJOR_VERSION}.${EIGEN_MINOR_VERSION})
 
-# if the mercurial program is absent, this will leave the EIGEN_HG_CHANGESET string empty,
-# but won't stop CMake.
-execute_process(COMMAND hg tip -R ${CMAKE_SOURCE_DIR} OUTPUT_VARIABLE EIGEN_HGTIP_OUTPUT)
-execute_process(COMMAND hg branch -R ${CMAKE_SOURCE_DIR} OUTPUT_VARIABLE EIGEN_BRANCH_OUTPUT)
+# if we are not in a mercurial clone
+if(IS_DIRECTORY ${CMAKE_SOURCE_DIR}/.hg)
+  # if the mercurial program is absent or this will leave the EIGEN_HG_CHANGESET string empty,
+  # but won't stop CMake.
+  execute_process(COMMAND hg tip -R ${CMAKE_SOURCE_DIR} OUTPUT_VARIABLE EIGEN_HGTIP_OUTPUT)
+  execute_process(COMMAND hg branch -R ${CMAKE_SOURCE_DIR} OUTPUT_VARIABLE EIGEN_BRANCH_OUTPUT)
+endif()
 
 # if this is the default (aka development) branch, extract the mercurial changeset number from the hg tip output...
 if(EIGEN_BRANCH_OUTPUT MATCHES "default")

unsupported/Eigen/CXX11/src/Tensor/TensorDeviceThreadPool.h

diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorDeviceThreadPool.h b/unsupported/Eigen/CXX11/src/Tensor/TensorDeviceThreadPool.h
index ec6802e..ca9ba40 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorDeviceThreadPool.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorDeviceThreadPool.h
@@ -169,7 +169,7 @@
 
   // parallelFor executes f with [0, n) arguments in parallel and waits for
   // completion. F accepts a half-open interval [first, last).
-  // Block size is choosen based on the iteration cost and resulting parallel
+  // Block size is chosen based on the iteration cost and resulting parallel
   // efficiency. If block_align is not nullptr, it is called to round up the
   // block size.
   void parallelFor(Index n, const TensorOpCost& cost,
@@ -261,6 +261,9 @@
     parallelFor(n, cost, nullptr, std::move(f));
   }
 
+  // Thread pool accessor.
+  ThreadPoolInterface* getPool() const { return pool_; }
+
  private:
   ThreadPoolInterface* pool_;
   int num_threads_;