--- MITgcm/model/inc/CPP_OPTIONS.h	2009/11/23 16:13:57	1.44
+++ MITgcm/model/inc/CPP_OPTIONS.h	2012/05/11 23:36:56	1.48
@@ -1,4 +1,4 @@
-C $Header: /home/ubuntu/mnt/e9_copy/MITgcm/model/inc/CPP_OPTIONS.h,v 1.44 2009/11/23 16:13:57 mlosch Exp $
+C $Header: /home/ubuntu/mnt/e9_copy/MITgcm/model/inc/CPP_OPTIONS.h,v 1.48 2012/05/11 23:36:56 jmc Exp $
 C $Name:  $
 
 #ifndef CPP_OPTIONS_H
@@ -28,8 +28,8 @@
 C o Include/exclude AdamsBashforth-3rd-Order code
 #undef ALLOW_ADAMSBASHFORTH_3
 
-C o Include/exclude code for single reduction cg-solver
-#undef ALLOW_SRCG
+C o Include/exclude code for single reduction Conjugate-Gradient solver
+#define ALLOW_SRCG
 
 C o Include/exclude nonHydrostatic code
 #undef ALLOW_NONHYDROSTATIC
@@ -57,6 +57,12 @@
 C   (3-D generalisation of oceanic real-fresh water flux)
 #undef ALLOW_ADDFLUID
 
+C o Choices for implicit solver routines solve_*diagonal.F
+C   The following has low memory footprint, but not suitable for AD
+#undef SOLVE_DIAGONAL_LOWMEMORY
+C   The following one suitable for AD but does not vectorize
+#undef SOLVE_DIAGONAL_KINNER
+
 C o ALLOW isotropic scaling of harmonic and bi-harmonic terms when
 C   using an locally isotropic spherical grid with (dlambda) x (dphi*cos(phi))
 C *only for use on a lat-lon grid*