Squashed 'third_party/eigen/' content from commit 61d72f6

Change-Id: Iccc90fa0b55ab44037f018046d2fcffd90d9d025
git-subtree-dir: third_party/eigen
git-subtree-split: 61d72f6383cfa842868c53e30e087b0258177257
diff --git a/test/first_aligned.cpp b/test/first_aligned.cpp
new file mode 100644
index 0000000..467f945
--- /dev/null
+++ b/test/first_aligned.cpp
@@ -0,0 +1,51 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra.
+//
+// Copyright (C) 2009 Benoit Jacob <jacob.benoit.1@gmail.com>
+//
+// This Source Code Form is subject to the terms of the Mozilla
+// Public License v. 2.0. If a copy of the MPL was not distributed
+// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#include "main.h"
+
+template<typename Scalar>
+void test_first_aligned_helper(Scalar *array, int size)
+{
+  const int packet_size = sizeof(Scalar) * internal::packet_traits<Scalar>::size;
+  VERIFY(((size_t(array) + sizeof(Scalar) * internal::first_aligned(array, size)) % packet_size) == 0);
+}
+
+template<typename Scalar>
+void test_none_aligned_helper(Scalar *array, int size)
+{
+  EIGEN_UNUSED_VARIABLE(array);
+  EIGEN_UNUSED_VARIABLE(size);
+  VERIFY(internal::packet_traits<Scalar>::size == 1 || internal::first_aligned(array, size) == size);
+}
+
+struct some_non_vectorizable_type { float x; };
+
+void test_first_aligned()
+{
+  EIGEN_ALIGN16 float array_float[100];
+  test_first_aligned_helper(array_float, 50);
+  test_first_aligned_helper(array_float+1, 50);
+  test_first_aligned_helper(array_float+2, 50);
+  test_first_aligned_helper(array_float+3, 50);
+  test_first_aligned_helper(array_float+4, 50);
+  test_first_aligned_helper(array_float+5, 50);
+  
+  EIGEN_ALIGN16 double array_double[100];
+  test_first_aligned_helper(array_double, 50);
+  test_first_aligned_helper(array_double+1, 50);
+  test_first_aligned_helper(array_double+2, 50);
+  
+  double *array_double_plus_4_bytes = (double*)(size_t(array_double)+4);
+  test_none_aligned_helper(array_double_plus_4_bytes, 50);
+  test_none_aligned_helper(array_double_plus_4_bytes+1, 50);
+  
+  some_non_vectorizable_type array_nonvec[100];
+  test_first_aligned_helper(array_nonvec, 100);
+  test_none_aligned_helper(array_nonvec, 100);
+}