From be281e528967ed00ed52f50a476beef10ff0dec3 Mon Sep 17 00:00:00 2001
From: Jim Radford <radford@blackbean.org>
Date: Wed, 4 Jan 2017 14:43:56 -0800
Subject: [PATCH] LLT: avoid making a copy when decomposing in place

---
 Eigen/src/Cholesky/LLT.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Eigen/src/Cholesky/LLT.h b/Eigen/src/Cholesky/LLT.h
index 7f29dad9c..c7683232d 100644
--- a/Eigen/src/Cholesky/LLT.h
+++ b/Eigen/src/Cholesky/LLT.h
@@ -428,7 +428,8 @@ LLT<MatrixType,_UpLo>& LLT<MatrixType,_UpLo>::compute(const EigenBase<InputType>
   eigen_assert(a.rows()==a.cols());
   const Index size = a.rows();
   m_matrix.resize(size, size);
-  m_matrix = a.derived();
+  if (!internal::is_same_dense(m_matrix, a.derived()))
+    m_matrix = a.derived();
 
   // Compute matrix L1 norm = max abs column sum.
   m_l1_norm = RealScalar(0);