From 3b8985fb6e5e31ada5778e467445caf4f9bccf4b Mon Sep 17 00:00:00 2001
From: Mike Sheffler <msheffler@toyon.com>
Date: Tue, 11 Sep 2018 00:22:20 -0700
Subject: [PATCH] Test of AutoDiff wrapper in an expression modified so that
 the upAligned size of the relevant binary expression is tested against the 
 size of the expression in the AutoDiff wrapper. When the traceSize() of the
 expression containing the AutoDiff wrapper is computed, that value (the
 traceSize) will be computed such that an alignment (currently 16-bit) will be
 forced. It is thus necessary for the test to also upAlign the relevant binary
 expression. On x86_64 architectures, this test was accidentally passing
 because the relevant struct was already aligned on a 16-bit boundary. On
 AArch64 ('ARM64'), the alignment was *not* on a 16-bit boundary, and this
 test failed. Modifying the first argument to EXPECT_LONGS_EQUAL in this test
 to include upAlignment of the relevant binary expression makes the test pass
 in 'debug' and 'release' builds on both x86_64 and AArch64 architectures

---
 gtsam/nonlinear/tests/testAdaptAutoDiff.cpp | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/gtsam/nonlinear/tests/testAdaptAutoDiff.cpp b/gtsam/nonlinear/tests/testAdaptAutoDiff.cpp
index aa50ce73f..a85118c00 100644
--- a/gtsam/nonlinear/tests/testAdaptAutoDiff.cpp
+++ b/gtsam/nonlinear/tests/testAdaptAutoDiff.cpp
@@ -231,14 +231,22 @@ TEST(AdaptAutoDiff, AdaptAutoDiff) {
 /* ************************************************************************* */
 // Test AutoDiff wrapper in an expression
 TEST(AdaptAutoDiff, SnavelyExpression) {
+  typedef AdaptAutoDiff<SnavelyProjection, 2, 9, 3> Adaptor;
+
   Expression<Vector9> P(1);
   Expression<Vector3> X(2);
-  typedef AdaptAutoDiff<SnavelyProjection, 2, 9, 3> Adaptor;
+
   Expression<Vector2> expression(Adaptor(), P, X);
+
+  std::size_t RecordSize =
+    sizeof(internal::BinaryExpression<Vector2, Vector9, Vector3>::Record);
+
   EXPECT_LONGS_EQUAL(
-      sizeof(internal::BinaryExpression<Vector2, Vector9, Vector3>::Record),
-      expression.traceSize());
+    internal::upAligned(RecordSize) + P.traceSize() + X.traceSize(),
+    expression.traceSize());
+
   set<Key> expected = list_of(1)(2);
+
   EXPECT(expected == expression.keys());
 }