tree 6b8d4effae4bcd44cd708e6b234da79f625e992b
parent 857c18ace09ab8becaf3406b917f9cd13921d2bf
author Sameer Agarwal <sameeragarwal@google.com> 1428268872 -0700
committer Sameer Agarwal <sameeragarwal@google.com> 1428299441 -0700

Allow using Eigen's LDLT factorization instead of LLT factorization

It seems that Eigen's LLT factorization is broken on ARM.
This patch enables the use of LDLT factorization instead of LLT
factorization. The switch is controlled at compile time using a
preprocessor define - CERES_USE_EIGEN_LDLT.

By default we continue to use LLT factorization though.

To make the switching easier without introducing the Cholesky factorization
based inversion and linear system solve routines have been abstracted into
two new functions.

Android.mk has been updated to enable the LDLT factorization, but
the cmake file has not been updated as I will leave it to Alex's
capable hands to do proper detection of ARM as a target platform.

Change-Id: Iffe3abd2ce894de2a388b454df3da909b482d5e5