diff --git a/contrib/platform/win32/ConfigFiles/mpi.h.cmake b/contrib/platform/win32/ConfigFiles/mpi.h.cmake
index df1afc46ba..d7877e00af 100644
--- a/contrib/platform/win32/ConfigFiles/mpi.h.cmake
+++ b/contrib/platform/win32/ConfigFiles/mpi.h.cmake
@@ -10,6 +10,7 @@
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
  * Copyright (c) 2007-2008 Cisco Systems, Inc.  All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc.  All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -476,15 +477,15 @@ enum {
 /*
  * NULL handles
  */
-#define MPI_GROUP_NULL (&ompi_mpi_group_null)
-#define MPI_COMM_NULL (&ompi_mpi_comm_null)
-#define MPI_REQUEST_NULL (&ompi_request_null)
-#define MPI_OP_NULL (&ompi_mpi_op_null)
-#define MPI_ERRHANDLER_NULL (&ompi_mpi_errhandler_null)
-#define MPI_INFO_NULL (&ompi_mpi_info_null)
-#define MPI_WIN_NULL (&ompi_mpi_win_null)
+#define MPI_GROUP_NULL (((MPI_Group)&(ompi_mpi_group_null)))
+#define MPI_COMM_NULL (((MPI_Comm)&(ompi_mpi_comm_null)))
+#define MPI_REQUEST_NULL (((MPI_Request)&(ompi_request_null)))
+#define MPI_OP_NULL (((MPI_Op)&(ompi_mpi_op_null)))
+#define MPI_ERRHANDLER_NULL (((MPI_Errhandler)&(ompi_mpi_errhandler_null)))
+#define MPI_INFO_NULL (((MPI_Info)&(ompi_mpi_info_null)))
+#define MPI_WIN_NULL (((MPI_Win)&(ompi_mpi_win_null)))
 #if OMPI_PROVIDE_MPI_FILE_INTERFACE
-#define MPI_FILE_NULL (&ompi_mpi_file_null)
+#define MPI_FILE_NULL (((MPI_File)&(ompi_mpi_file_null)))
 #endif
 
 #define MPI_STATUS_IGNORE ((MPI_Status *) 0)
@@ -596,107 +597,111 @@ OMPI_DECLSPEC int OMPI_C_MPI_WIN_DUP_FN( MPI_Win window, int win_keyval,
 /*
  * External variables
  */
-OMPI_DECLSPEC extern struct ompi_communicator_t ompi_mpi_comm_world;
-OMPI_DECLSPEC extern struct ompi_communicator_t ompi_mpi_comm_self;
-OMPI_DECLSPEC extern struct ompi_communicator_t ompi_mpi_comm_null;
+OMPI_DECLSPEC extern union ompi_predefined_communicator_t ompi_mpi_comm_world;
+OMPI_DECLSPEC extern union ompi_predefined_communicator_t ompi_mpi_comm_self;
+OMPI_DECLSPEC extern union ompi_predefined_communicator_t ompi_mpi_comm_null;
 
-OMPI_DECLSPEC extern struct ompi_group_t ompi_mpi_group_empty;
-OMPI_DECLSPEC extern struct ompi_group_t ompi_mpi_group_null;
+OMPI_DECLSPEC extern union ompi_predefined_group_t ompi_mpi_group_empty;
+OMPI_DECLSPEC extern union ompi_predefined_group_t ompi_mpi_group_null;
 
-OMPI_DECLSPEC extern struct ompi_request_t ompi_request_null;
+OMPI_DECLSPEC extern union ompi_predefined_request_t ompi_request_null;
 
-OMPI_DECLSPEC extern struct ompi_op_t ompi_mpi_op_null;
-OMPI_DECLSPEC extern struct ompi_op_t ompi_mpi_op_max, ompi_mpi_op_min;
-OMPI_DECLSPEC extern struct ompi_op_t ompi_mpi_op_sum, ompi_mpi_op_prod;
-OMPI_DECLSPEC extern struct ompi_op_t ompi_mpi_op_land, ompi_mpi_op_band;
-OMPI_DECLSPEC extern struct ompi_op_t ompi_mpi_op_lor, ompi_mpi_op_bor;
-OMPI_DECLSPEC extern struct ompi_op_t ompi_mpi_op_lxor, ompi_mpi_op_bxor;
-OMPI_DECLSPEC extern struct ompi_op_t ompi_mpi_op_maxloc, ompi_mpi_op_minloc;
-OMPI_DECLSPEC extern struct ompi_op_t ompi_mpi_op_replace;
+OMPI_DECLSPEC extern union ompi_predefined_op_t ompi_mpi_op_null;
+OMPI_DECLSPEC extern union ompi_predefined_op_t ompi_mpi_op_max, ompi_mpi_op_min;
+OMPI_DECLSPEC extern union ompi_predefined_op_t ompi_mpi_op_sum;
+OMPI_DECLSPEC extern union ompi_predefined_op_t ompi_mpi_op_prod;
+OMPI_DECLSPEC extern union ompi_predefined_op_t ompi_mpi_op_land;
+OMPI_DECLSPEC extern union ompi_predefined_op_t ompi_mpi_op_band;
+OMPI_DECLSPEC extern union ompi_predefined_op_t ompi_mpi_op_lor, ompi_mpi_op_bor;
+OMPI_DECLSPEC extern union ompi_predefined_op_t ompi_mpi_op_lxor;
+OMPI_DECLSPEC extern union ompi_predefined_op_t ompi_mpi_op_bxor;
+OMPI_DECLSPEC extern union ompi_predefined_op_t ompi_mpi_op_maxloc;
+OMPI_DECLSPEC extern union ompi_predefined_op_t ompi_mpi_op_minloc;
+OMPI_DECLSPEC extern union ompi_predefined_op_t ompi_mpi_op_replace;
 
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_char, ompi_mpi_byte;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_int, ompi_mpi_logic;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_short, ompi_mpi_long;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_float, ompi_mpi_double;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_long_double;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_cplex, ompi_mpi_packed;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_signed_char;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_unsigned_char;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_unsigned_short;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_unsigned, ompi_mpi_datatype_null;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_unsigned_long, ompi_mpi_ldblcplex;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_ub, ompi_mpi_lb;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_float_int, ompi_mpi_double_int;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_long_int, ompi_mpi_2int;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_short_int, ompi_mpi_dblcplex;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_integer, ompi_mpi_real;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_dblprec, ompi_mpi_character;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_2real, ompi_mpi_2dblprec;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_2integer, ompi_mpi_longdbl_int;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_wchar, ompi_mpi_long_long_int;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_unsigned_long_long;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_cxx_cplex, ompi_mpi_cxx_dblcplex;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_cxx_ldblcplex;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_cxx_bool;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_2cplex, ompi_mpi_2dblcplex;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_char, ompi_mpi_byte;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_int, ompi_mpi_logic;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_short, ompi_mpi_long;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_float, ompi_mpi_double;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_long_double;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_cplex, ompi_mpi_packed;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_signed_char;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_unsigned_char;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_unsigned_short;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_unsigned, ompi_mpi_datatype_null;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_unsigned_long, ompi_mpi_ldblcplex;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_ub, ompi_mpi_lb;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_float_int, ompi_mpi_double_int;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_long_int, ompi_mpi_2int;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_short_int, ompi_mpi_dblcplex;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_integer, ompi_mpi_real;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_dblprec, ompi_mpi_character;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_2real, ompi_mpi_2dblprec;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_2integer, ompi_mpi_longdbl_int;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_wchar, ompi_mpi_long_long_int;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_unsigned_long_long;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_cxx_cplex, ompi_mpi_cxx_dblcplex;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_cxx_ldblcplex;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_cxx_bool;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_2cplex, ompi_mpi_2dblcplex;
 /* other MPI2 datatypes */
 #if OMPI_HAVE_FORTRAN_LOGICAL1
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_logical1;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_logical1;
 #endif
 #if OMPI_HAVE_FORTRAN_LOGICAL2
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_logical2;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_logical2;
 #endif
 #if OMPI_HAVE_FORTRAN_LOGICAL4
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_logical4;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_logical4;
 #endif
 #if OMPI_HAVE_FORTRAN_LOGICAL8
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_logical8;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_logical8;
 #endif
 #if OMPI_HAVE_FORTRAN_INTEGER1
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_integer1;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_integer1;
 #endif
 #if OMPI_HAVE_FORTRAN_INTEGER2
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_integer2;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_integer2;
 #endif
 #if OMPI_HAVE_FORTRAN_INTEGER4
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_integer4;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_integer4;
 #endif
 #if OMPI_HAVE_FORTRAN_INTEGER8
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_integer8;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_integer8;
 #endif
 #if OMPI_HAVE_FORTRAN_INTEGER16
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_integer16;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_integer16;
 #endif
 #if OMPI_HAVE_FORTRAN_REAL2
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_real2;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_real2;
 #endif
 #if OMPI_HAVE_FORTRAN_REAL4
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_real4; 
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_real4; 
 #endif
 #if OMPI_HAVE_FORTRAN_REAL8
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_real8;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_real8;
 #endif
 #if OMPI_HAVE_FORTRAN_REAL16
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_real16;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_real16;
 #endif
 #if OMPI_HAVE_FORTRAN_REAL4
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_complex8;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_complex8;
 #endif
 #if OMPI_HAVE_FORTRAN_REAL8
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_complex16;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_complex16;
 #endif
 #if OMPI_HAVE_FORTRAN_REAL16
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_complex32;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_complex32;
 #endif
 
-OMPI_DECLSPEC extern struct ompi_errhandler_t ompi_mpi_errhandler_null;
-OMPI_DECLSPEC extern struct ompi_errhandler_t ompi_mpi_errors_are_fatal;
-OMPI_DECLSPEC extern struct ompi_errhandler_t ompi_mpi_errors_return;
+OMPI_DECLSPEC extern union ompi_predefined_errhandler_t ompi_mpi_errhandler_null;
+OMPI_DECLSPEC extern union ompi_predefined_errhandler_t ompi_mpi_errors_are_fatal;
+OMPI_DECLSPEC extern union ompi_predefined_errhandler_t ompi_mpi_errors_return;
 
-OMPI_DECLSPEC extern struct ompi_win_t ompi_mpi_win_null;
-OMPI_DECLSPEC extern struct ompi_file_t ompi_mpi_file_null;
+OMPI_DECLSPEC extern union ompi_predefined_win_t ompi_mpi_win_null;
+OMPI_DECLSPEC extern union ompi_predefined_file_t ompi_mpi_file_null;
 
-OMPI_DECLSPEC extern struct ompi_info_t ompi_mpi_info_null;
+OMPI_DECLSPEC extern union ompi_predefined_info_t ompi_mpi_info_null;
 
 OMPI_DECLSPEC extern MPI_Fint *MPI_F_STATUS_IGNORE;
 OMPI_DECLSPEC extern MPI_Fint *MPI_F_STATUSES_IGNORE;
@@ -704,117 +709,117 @@ OMPI_DECLSPEC extern MPI_Fint *MPI_F_STATUSES_IGNORE;
 /*
  * MPI predefined handles
  */
-#define MPI_COMM_WORLD (&ompi_mpi_comm_world)
-#define MPI_COMM_SELF (&ompi_mpi_comm_self)
+#define MPI_COMM_WORLD (((MPI_Comm)&(ompi_mpi_comm_world)))
+#define MPI_COMM_SELF (((MPI_Comm)&(ompi_mpi_comm_self)))
 
-#define MPI_GROUP_EMPTY (&ompi_mpi_group_empty)
+#define MPI_GROUP_EMPTY (((MPI_Group)&(ompi_mpi_group_empty)))
 
-#define MPI_MAX (&ompi_mpi_op_max)
-#define MPI_MIN (&ompi_mpi_op_min)
-#define MPI_SUM (&ompi_mpi_op_sum)
-#define MPI_PROD (&ompi_mpi_op_prod)
-#define MPI_LAND (&ompi_mpi_op_land)
-#define MPI_BAND (&ompi_mpi_op_band)
-#define MPI_LOR (&ompi_mpi_op_lor)
-#define MPI_BOR (&ompi_mpi_op_bor)
-#define MPI_LXOR (&ompi_mpi_op_lxor)
-#define MPI_BXOR (&ompi_mpi_op_bxor)
-#define MPI_MAXLOC (&ompi_mpi_op_maxloc)
-#define MPI_MINLOC (&ompi_mpi_op_minloc)
-#define MPI_REPLACE (&ompi_mpi_op_replace)
+#define MPI_MAX (((MPI_Op)&(ompi_mpi_op_max)))
+#define MPI_MIN (((MPI_Op)&(ompi_mpi_op_min)))
+#define MPI_SUM (((MPI_Op)&(ompi_mpi_op_sum)))
+#define MPI_PROD (((MPI_Op)&(ompi_mpi_op_prod)))
+#define MPI_LAND (((MPI_Op)&(ompi_mpi_op_land)))
+#define MPI_BAND (((MPI_Op)&(ompi_mpi_op_band)))
+#define MPI_LOR (((MPI_Op)&(ompi_mpi_op_lor)))
+#define MPI_BOR (((MPI_Op)&(ompi_mpi_op_bor)))
+#define MPI_LXOR (((MPI_Op)&(ompi_mpi_op_lxor)))
+#define MPI_BXOR (((MPI_Op)&(ompi_mpi_op_bxor)))
+#define MPI_MAXLOC (((MPI_Op)&(ompi_mpi_op_maxloc)))
+#define MPI_MINLOC (((MPI_Op)&(ompi_mpi_op_minloc)))
+#define MPI_REPLACE (((MPI_Op)&(ompi_mpi_op_replace)))
 
 /* C datatypes */
-#define MPI_DATATYPE_NULL (&ompi_mpi_datatype_null)
-#define MPI_BYTE (&ompi_mpi_byte)
-#define MPI_PACKED (&ompi_mpi_packed)
-#define MPI_CHAR (&ompi_mpi_char)
-#define MPI_SHORT (&ompi_mpi_short)
-#define MPI_INT (&ompi_mpi_int)
-#define MPI_LONG (&ompi_mpi_long)
-#define MPI_FLOAT (&ompi_mpi_float)
-#define MPI_DOUBLE (&ompi_mpi_double)
-#define MPI_LONG_DOUBLE (&ompi_mpi_long_double)
-#define MPI_UNSIGNED_CHAR (&ompi_mpi_unsigned_char)
-#define MPI_SIGNED_CHAR (&ompi_mpi_signed_char)
-#define MPI_UNSIGNED_SHORT (&ompi_mpi_unsigned_short)
-#define MPI_UNSIGNED_LONG (&ompi_mpi_unsigned_long)
-#define MPI_UNSIGNED (&ompi_mpi_unsigned)
-#define MPI_FLOAT_INT (&ompi_mpi_float_int)
-#define MPI_DOUBLE_INT (&ompi_mpi_double_int)
-#define MPI_LONG_DOUBLE_INT (&ompi_mpi_longdbl_int)
-#define MPI_LONG_INT (&ompi_mpi_long_int)
-#define MPI_SHORT_INT (&ompi_mpi_short_int)
-#define MPI_2INT (&ompi_mpi_2int)
-#define MPI_UB (&ompi_mpi_ub)
-#define MPI_LB (&ompi_mpi_lb)
-#define MPI_WCHAR (&ompi_mpi_wchar)
+#define MPI_DATATYPE_NULL (((MPI_Datatype)&(ompi_mpi_datatype_null)))
+#define MPI_BYTE (((MPI_Datatype)&(ompi_mpi_byte)))
+#define MPI_PACKED (((MPI_Datatype)&(ompi_mpi_packed)))
+#define MPI_CHAR (((MPI_Datatype)&(ompi_mpi_char)))
+#define MPI_SHORT (((MPI_Datatype)&(ompi_mpi_short)))
+#define MPI_INT (((MPI_Datatype)&(ompi_mpi_int)))
+#define MPI_LONG (((MPI_Datatype)&(ompi_mpi_long)))
+#define MPI_FLOAT (((MPI_Datatype)&(ompi_mpi_float)))
+#define MPI_DOUBLE (((MPI_Datatype)&(ompi_mpi_double)))
+#define MPI_LONG_DOUBLE (((MPI_Datatype)&(ompi_mpi_long_double)))
+#define MPI_UNSIGNED_CHAR (((MPI_Datatype)&(ompi_mpi_unsigned_char)))
+#define MPI_SIGNED_CHAR (((MPI_Datatype)&(ompi_mpi_signed_char)))
+#define MPI_UNSIGNED_SHORT (((MPI_Datatype)&(ompi_mpi_unsigned_short)))
+#define MPI_UNSIGNED_LONG (((MPI_Datatype)&(ompi_mpi_unsigned_long)))
+#define MPI_UNSIGNED (((MPI_Datatype)&(ompi_mpi_unsigned)))
+#define MPI_FLOAT_INT (((MPI_Datatype)&(ompi_mpi_float_int)))
+#define MPI_DOUBLE_INT (((MPI_Datatype)&(ompi_mpi_double_int)))
+#define MPI_LONG_DOUBLE_INT (((MPI_Datatype)&(ompi_mpi_longdbl_int)))
+#define MPI_LONG_INT (((MPI_Datatype)&(ompi_mpi_long_int)))
+#define MPI_SHORT_INT (((MPI_Datatype)&(ompi_mpi_short_int)))
+#define MPI_2INT (((MPI_Datatype)&(ompi_mpi_2int)))
+#define MPI_UB (((MPI_Datatype)&(ompi_mpi_ub)))
+#define MPI_LB (((MPI_Datatype)&(ompi_mpi_lb)))
+#define MPI_WCHAR (((MPI_Datatype)&(ompi_mpi_wchar)))
 #if OMPI_HAVE_LONG_LONG
-#define MPI_LONG_LONG_INT (&ompi_mpi_long_long_int)
-#define MPI_LONG_LONG (&ompi_mpi_long_long_int)
-#define MPI_UNSIGNED_LONG_LONG (&ompi_mpi_unsigned_long_long)
+#define MPI_LONG_LONG_INT (((MPI_Datatype)&(ompi_mpi_long_long_int)))
+#define MPI_LONG_LONG (((MPI_Datatype)&(ompi_mpi_long_long_int)))
+#define MPI_UNSIGNED_LONG_LONG (((MPI_Datatype)&(ompi_mpi_unsigned_long_long)))
 #endif  /* OMPI_HAVE_LONG_LONG */
-#define MPI_2COMPLEX (&ompi_mpi_2cplex)
-#define MPI_2DOUBLE_COMPLEX (&ompi_mpi_2dblcplex)
+#define MPI_2COMPLEX (((MPI_Datatype)&(ompi_mpi_2cplex)))
+#define MPI_2DOUBLE_COMPLEX (((MPI_Datatype)&(ompi_mpi_2dblcplex)))
 
 /* Fortran datatype bindings */
-#define MPI_CHARACTER (&ompi_mpi_character)
-#define MPI_LOGICAL (&ompi_mpi_logic)
+#define MPI_CHARACTER (((MPI_Datatype)&(ompi_mpi_character)))
+#define MPI_LOGICAL (((MPI_Datatype)&(ompi_mpi_logic)))
 #if OMPI_HAVE_FORTRAN_LOGICAL1
-#define MPI_LOGICAL1 (&ompi_mpi_logical1)
+#define MPI_LOGICAL1 (((MPI_Datatype)&(ompi_mpi_logical1)))
 #endif
 #if OMPI_HAVE_FORTRAN_LOGICAL2
-#define MPI_LOGICAL2 (&ompi_mpi_logical2)
+#define MPI_LOGICAL2 (((MPI_Datatype)&(ompi_mpi_logical2)))
 #endif
 #if OMPI_HAVE_FORTRAN_LOGICAL4
-#define MPI_LOGICAL4 (&ompi_mpi_logical4)
+#define MPI_LOGICAL4 (((MPI_Datatype)&(ompi_mpi_logical4)))
 #endif
 #if OMPI_HAVE_FORTRAN_LOGICAL8
-#define MPI_LOGICAL8 (&ompi_mpi_logical8)
+#define MPI_LOGICAL8 (((MPI_Datatype)&(ompi_mpi_logical8)))
 #endif
-#define MPI_INTEGER (&ompi_mpi_integer)
+#define MPI_INTEGER (((MPI_Datatype)&(ompi_mpi_integer)))
 #if OMPI_HAVE_FORTRAN_INTEGER1
-#define MPI_INTEGER1 (&ompi_mpi_integer1)
+#define MPI_INTEGER1 (((MPI_Datatype)&(ompi_mpi_integer1)))
 #endif
 #if OMPI_HAVE_FORTRAN_INTEGER2
-#define MPI_INTEGER2 (&ompi_mpi_integer2)
+#define MPI_INTEGER2 (((MPI_Datatype)&(ompi_mpi_integer2)))
 #endif
 #if OMPI_HAVE_FORTRAN_INTEGER4
-#define MPI_INTEGER4 (&ompi_mpi_integer4)
+#define MPI_INTEGER4 (((MPI_Datatype)&(ompi_mpi_integer4)))
 #endif
 #if OMPI_HAVE_FORTRAN_INTEGER8
-#define MPI_INTEGER8 (&ompi_mpi_integer8)
+#define MPI_INTEGER8 (((MPI_Datatype)&(ompi_mpi_integer8)))
 #endif
 #if OMPI_HAVE_FORTRAN_INTEGER16
-#define MPI_INTEGER16 (&ompi_mpi_integer16)
+#define MPI_INTEGER16 (((MPI_Datatype)&(ompi_mpi_integer16)))
 #endif
-#define MPI_REAL (&ompi_mpi_real)
+#define MPI_REAL (((MPI_Datatype)&(ompi_mpi_real)))
 #if OMPI_HAVE_FORTRAN_REAL4
-#define MPI_REAL4 (&ompi_mpi_real4)
+#define MPI_REAL4 (((MPI_Datatype)&(ompi_mpi_real4)))
 #endif
 #if OMPI_HAVE_FORTRAN_REAL8
-#define MPI_REAL8 (&ompi_mpi_real8)
+#define MPI_REAL8 (((MPI_Datatype)&(ompi_mpi_real8)))
 #endif
 #if OMPI_HAVE_FORTRAN_REAL16
-#define MPI_REAL16 (&ompi_mpi_real16)
+#define MPI_REAL16 (((MPI_Datatype)&(ompi_mpi_real16)))
 #endif
-#define MPI_DOUBLE_PRECISION (&ompi_mpi_dblprec)
-#define MPI_COMPLEX (&ompi_mpi_cplex)
+#define MPI_DOUBLE_PRECISION (((MPI_Datatype)&(ompi_mpi_dblprec)))
+#define MPI_COMPLEX (((MPI_Datatype)&(ompi_mpi_cplex)))
 #if OMPI_HAVE_FORTRAN_REAL4
-#define MPI_COMPLEX8 (&ompi_mpi_complex8)
+#define MPI_COMPLEX8 (((MPI_Datatype)&(ompi_mpi_complex8)))
 #endif
 #if OMPI_HAVE_FORTRAN_REAL8
-#define MPI_COMPLEX16 (&ompi_mpi_complex16)
+#define MPI_COMPLEX16 (((MPI_Datatype)&(ompi_mpi_complex16)))
 #endif
 #if OMPI_HAVE_FORTRAN_REAL16
-#define MPI_COMPLEX32 (&ompi_mpi_complex32)
+#define MPI_COMPLEX32 (((MPI_Datatype)&(ompi_mpi_complex32)))
 #endif
-#define MPI_DOUBLE_COMPLEX (&ompi_mpi_dblcplex)
-#define MPI_2REAL (&ompi_mpi_2real)
-#define MPI_2DOUBLE_PRECISION (&ompi_mpi_2dblprec)
-#define MPI_2INTEGER (&ompi_mpi_2integer)
+#define MPI_DOUBLE_COMPLEX (((MPI_Datatype)&(ompi_mpi_dblcplex)))
+#define MPI_2REAL (((MPI_Datatype)&(ompi_mpi_2real)))
+#define MPI_2DOUBLE_PRECISION (((MPI_Datatype)&(ompi_mpi_2dblprec)))
+#define MPI_2INTEGER (((MPI_Datatype)&(ompi_mpi_2integer)))
 
-#define MPI_ERRORS_ARE_FATAL (&ompi_mpi_errors_are_fatal)
-#define MPI_ERRORS_RETURN (&ompi_mpi_errors_return)
+#define MPI_ERRORS_ARE_FATAL (((MPI_Errhandler)&(ompi_mpi_errors_are_fatal)))
+#define MPI_ERRORS_RETURN (((MPI_Errhandler)&(ompi_mpi_errors_return)))
 
 /* Typeclass definition for MPI_Type_match_size */
 #define MPI_TYPECLASS_INTEGER    1
diff --git a/ompi/communicator/comm.c b/ompi/communicator/comm.c
index 937ded09b5..53d075c453 100644
--- a/ompi/communicator/comm.c
+++ b/ompi/communicator/comm.c
@@ -11,6 +11,7 @@
  *                         All rights reserved.
  * Copyright (c) 2007-2008 University of Houston. All rights reserved.
  * Copyright (c) 2007-2008 Cisco Systems, Inc. All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc.  All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -960,7 +961,7 @@ int ompi_comm_free ( ompi_communicator_t **comm )
        COMM_NULL.  This is according to MPI-2:88-89. */
 
     if (*comm == ompi_mpi_comm_parent && comm != &ompi_mpi_comm_parent) {
-        ompi_mpi_comm_parent = &ompi_mpi_comm_null;
+        ompi_mpi_comm_parent = &ompi_mpi_comm_null.comm;
     }
 
     /* Release the communicator */
diff --git a/ompi/communicator/comm_cid.c b/ompi/communicator/comm_cid.c
index cdee170425..cccffe59b4 100644
--- a/ompi/communicator/comm_cid.c
+++ b/ompi/communicator/comm_cid.c
@@ -13,6 +13,7 @@
  * Copyright (c) 2007      Cisco Systems, Inc.  All rights reserved.
  * Copyright (c) 2007      Voltaire All rights reserved.
  * Copyright (c) 2006-2008 University of Houston.  All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc.  All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -26,6 +27,7 @@
 #include "opal/util/convert.h"
 #include "orte/types.h"
 #include "ompi/communicator/communicator.h"
+#include "ompi/op/op.h"
 #include "ompi/proc/proc.h"
 #include "ompi/constants.h"
 #include "opal/class/opal_pointer_array.h"
@@ -497,8 +499,8 @@ static int ompi_comm_allreduce_inter ( int *inbuf, int *outbuf,
     int *rcounts=NULL, scount=0;
     int *rdisps=NULL;
 
-    if ( &ompi_mpi_op_sum != op && &ompi_mpi_op_prod != op &&
-         &ompi_mpi_op_max != op && &ompi_mpi_op_min  != op ) {
+    if ( &ompi_mpi_op_sum.op != op && &ompi_mpi_op_prod.op != op &&
+         &ompi_mpi_op_max.op != op && &ompi_mpi_op_min.op  != op ) {
         return MPI_ERR_OP;
     }
 
@@ -552,22 +554,22 @@ static int ompi_comm_allreduce_inter ( int *inbuf, int *outbuf,
             goto exit;
         }
 
-        if ( &ompi_mpi_op_max == op ) {
+        if ( &ompi_mpi_op_max.op == op ) {
             for ( i = 0 ; i < count; i++ ) {
                 if (tmpbuf[i] > outbuf[i]) outbuf[i] = tmpbuf[i];
             }
         }
-        else if ( &ompi_mpi_op_min == op ) {
+        else if ( &ompi_mpi_op_min.op == op ) {
             for ( i = 0 ; i < count; i++ ) {
                 if (tmpbuf[i] < outbuf[i]) outbuf[i] = tmpbuf[i];
             }
         }
-        else if ( &ompi_mpi_op_sum == op ) {
+        else if ( &ompi_mpi_op_sum.op == op ) {
             for ( i = 0 ; i < count; i++ ) {
                 outbuf[i] += tmpbuf[i];
             }
         }
-        else if ( &ompi_mpi_op_prod == op ) {
+        else if ( &ompi_mpi_op_prod.op == op ) {
             for ( i = 0 ; i < count; i++ ) {
                 outbuf[i] *= tmpbuf[i];
             }
@@ -620,8 +622,8 @@ static int ompi_comm_allreduce_intra_bridge (int *inbuf, int *outbuf,
     local_leader  = (*((int*)lleader));
     remote_leader = (*((int*)rleader));
 
-    if ( &ompi_mpi_op_sum != op && &ompi_mpi_op_prod != op &&
-         &ompi_mpi_op_max != op && &ompi_mpi_op_min  != op ) {
+    if ( &ompi_mpi_op_sum.op != op && &ompi_mpi_op_prod.op != op &&
+         &ompi_mpi_op_max.op != op && &ompi_mpi_op_min.op  != op ) {
         return MPI_ERR_OP;
     }
     
@@ -659,22 +661,22 @@ static int ompi_comm_allreduce_intra_bridge (int *inbuf, int *outbuf,
             goto exit;
         }
 
-        if ( &ompi_mpi_op_max == op ) {
+        if ( &ompi_mpi_op_max.op == op ) {
             for ( i = 0 ; i < count; i++ ) {
                 if (tmpbuf[i] > outbuf[i]) outbuf[i] = tmpbuf[i];
             }
         }
-        else if ( &ompi_mpi_op_min == op ) {
+        else if ( &ompi_mpi_op_min.op == op ) {
             for ( i = 0 ; i < count; i++ ) {
                 if (tmpbuf[i] < outbuf[i]) outbuf[i] = tmpbuf[i];
             }
         }
-        else if ( &ompi_mpi_op_sum == op ) {
+        else if ( &ompi_mpi_op_sum.op == op ) {
             for ( i = 0 ; i < count; i++ ) {
                 outbuf[i] += tmpbuf[i];
             }
         }
-        else if ( &ompi_mpi_op_prod == op ) {
+        else if ( &ompi_mpi_op_prod.op == op ) {
             for ( i = 0 ; i < count; i++ ) {
                 outbuf[i] *= tmpbuf[i];
             }
@@ -718,8 +720,8 @@ static int ompi_comm_allreduce_intra_oob (int *inbuf, int *outbuf,
     remote_leader = (orte_process_name_t*)rleader;
     size_count = count;
 
-    if ( &ompi_mpi_op_sum != op && &ompi_mpi_op_prod != op &&
-         &ompi_mpi_op_max != op && &ompi_mpi_op_min  != op ) {
+    if ( &ompi_mpi_op_sum.op != op && &ompi_mpi_op_prod.op != op &&
+         &ompi_mpi_op_max.op != op && &ompi_mpi_op_min.op  != op ) {
         return MPI_ERR_OP;
     }
     
@@ -773,22 +775,22 @@ static int ompi_comm_allreduce_intra_oob (int *inbuf, int *outbuf,
         OBJ_RELEASE(rbuf);
         count = (int)size_count;
 
-        if ( &ompi_mpi_op_max == op ) {
+        if ( &ompi_mpi_op_max.op == op ) {
             for ( i = 0 ; i < count; i++ ) {
                 if (tmpbuf[i] > outbuf[i]) outbuf[i] = tmpbuf[i];
             }
         }
-        else if ( &ompi_mpi_op_min == op ) {
+        else if ( &ompi_mpi_op_min.op == op ) {
             for ( i = 0 ; i < count; i++ ) {
                 if (tmpbuf[i] < outbuf[i]) outbuf[i] = tmpbuf[i];
             }
         }
-        else if ( &ompi_mpi_op_sum == op ) {
+        else if ( &ompi_mpi_op_sum.op == op ) {
             for ( i = 0 ; i < count; i++ ) {
                 outbuf[i] += tmpbuf[i];
             }
         }
-        else if ( &ompi_mpi_op_prod == op ) {
+        else if ( &ompi_mpi_op_prod.op == op ) {
             for ( i = 0 ; i < count; i++ ) {
                 outbuf[i] *= tmpbuf[i];
             }
diff --git a/ompi/communicator/comm_init.c b/ompi/communicator/comm_init.c
index aeeab417ef..3a6a00bb3a 100644
--- a/ompi/communicator/comm_init.c
+++ b/ompi/communicator/comm_init.c
@@ -12,6 +12,7 @@
  *                         All rights reserved.
  * Copyright (c) 2006-2007 University of Houston. All rights reserved.
  * Copyright (c) 2007      Cisco Systems, Inc. All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc. All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -43,9 +44,9 @@
 */
 opal_pointer_array_t ompi_mpi_communicators; 
 
-ompi_communicator_t  ompi_mpi_comm_world;
-ompi_communicator_t  ompi_mpi_comm_self;
-ompi_communicator_t  ompi_mpi_comm_null;
+ompi_predefined_communicator_t  ompi_mpi_comm_world;
+ompi_predefined_communicator_t  ompi_mpi_comm_self;
+ompi_predefined_communicator_t  ompi_mpi_comm_null;
 ompi_communicator_t  *ompi_mpi_comm_parent;
 
 static void ompi_comm_construct(ompi_communicator_t* comm);
@@ -84,31 +85,31 @@ int ompi_comm_init(void)
     ompi_set_group_rank(group, ompi_proc_local());
     ompi_group_increment_proc_count (group);
 
-    ompi_mpi_comm_world.c_contextid    = 0;
-    ompi_mpi_comm_world.c_id_start_index = 4;
-    ompi_mpi_comm_world.c_id_available = 4;
-    ompi_mpi_comm_world.c_f_to_c_index = 0;
-    ompi_mpi_comm_world.c_my_rank      = group->grp_my_rank;
-    ompi_mpi_comm_world.c_local_group  = group;
-    ompi_mpi_comm_world.c_remote_group = group;
-    OBJ_RETAIN(ompi_mpi_comm_world.c_remote_group);
-    ompi_mpi_comm_world.c_cube_dim     = opal_cube_dim((int)size);
-    ompi_mpi_comm_world.error_handler  = &ompi_mpi_errors_are_fatal;
-    OBJ_RETAIN( &ompi_mpi_errors_are_fatal );
-    OMPI_COMM_SET_PML_ADDED(&ompi_mpi_comm_world);
+    ompi_mpi_comm_world.comm.c_contextid    = 0;
+    ompi_mpi_comm_world.comm.c_id_start_index = 4;
+    ompi_mpi_comm_world.comm.c_id_available = 4;
+    ompi_mpi_comm_world.comm.c_f_to_c_index = 0;
+    ompi_mpi_comm_world.comm.c_my_rank      = group->grp_my_rank;
+    ompi_mpi_comm_world.comm.c_local_group  = group;
+    ompi_mpi_comm_world.comm.c_remote_group = group;
+    OBJ_RETAIN(ompi_mpi_comm_world.comm.c_remote_group);
+    ompi_mpi_comm_world.comm.c_cube_dim     = opal_cube_dim((int)size);
+    ompi_mpi_comm_world.comm.error_handler  = &ompi_mpi_errors_are_fatal.eh;
+    OBJ_RETAIN( &ompi_mpi_errors_are_fatal.eh );
+    OMPI_COMM_SET_PML_ADDED(&ompi_mpi_comm_world.comm);
     opal_pointer_array_set_item (&ompi_mpi_communicators, 0, &ompi_mpi_comm_world);
 
-    MEMCHECKER (memset (ompi_mpi_comm_world.c_name, 0, MPI_MAX_OBJECT_NAME));
-    strncpy (ompi_mpi_comm_world.c_name, "MPI_COMM_WORLD",
+    MEMCHECKER (memset (ompi_mpi_comm_world.comm.c_name, 0, MPI_MAX_OBJECT_NAME));
+    strncpy (ompi_mpi_comm_world.comm.c_name, "MPI_COMM_WORLD",
              strlen("MPI_COMM_WORLD")+1 );
-    ompi_mpi_comm_world.c_flags |= OMPI_COMM_NAMEISSET;
-    ompi_mpi_comm_world.c_flags |= OMPI_COMM_INTRINSIC;
+    ompi_mpi_comm_world.comm.c_flags |= OMPI_COMM_NAMEISSET;
+    ompi_mpi_comm_world.comm.c_flags |= OMPI_COMM_INTRINSIC;
 
     /* We have to create a hash (although it is legal to leave this
        filed NULL -- the attribute accessor functions will intepret
        this as "there are no attributes cached on this object")
        because MPI_COMM_WORLD has some predefined attributes. */
-    ompi_attr_hash_init(&ompi_mpi_comm_world.c_keyhash);
+    ompi_attr_hash_init(&ompi_mpi_comm_world.comm.c_keyhash);
 
     /* Setup MPI_COMM_SELF */
     OBJ_CONSTRUCT(&ompi_mpi_comm_self, ompi_communicator_t);
@@ -119,54 +120,54 @@ int ompi_comm_init(void)
     OMPI_GROUP_SET_INTRINSIC (group);
     OMPI_GROUP_SET_DENSE (group);
     
-    ompi_mpi_comm_self.c_contextid    = 1;
-    ompi_mpi_comm_self.c_f_to_c_index = 1;
-    ompi_mpi_comm_self.c_id_start_index = 20;
-    ompi_mpi_comm_self.c_id_available = 20;
-    ompi_mpi_comm_self.c_my_rank      = group->grp_my_rank;
-    ompi_mpi_comm_self.c_local_group  = group;
-    ompi_mpi_comm_self.c_remote_group = group;
-    OBJ_RETAIN(ompi_mpi_comm_self.c_remote_group);
-    ompi_mpi_comm_self.error_handler  = &ompi_mpi_errors_are_fatal;
-    OBJ_RETAIN( &ompi_mpi_errors_are_fatal );
-    OMPI_COMM_SET_PML_ADDED(&ompi_mpi_comm_self);
+    ompi_mpi_comm_self.comm.c_contextid    = 1;
+    ompi_mpi_comm_self.comm.c_f_to_c_index = 1;
+    ompi_mpi_comm_self.comm.c_id_start_index = 20;
+    ompi_mpi_comm_self.comm.c_id_available = 20;
+    ompi_mpi_comm_self.comm.c_my_rank      = group->grp_my_rank;
+    ompi_mpi_comm_self.comm.c_local_group  = group;
+    ompi_mpi_comm_self.comm.c_remote_group = group;
+    OBJ_RETAIN(ompi_mpi_comm_self.comm.c_remote_group);
+    ompi_mpi_comm_self.comm.error_handler  = &ompi_mpi_errors_are_fatal.eh;
+    OBJ_RETAIN( &ompi_mpi_errors_are_fatal.eh );
+    OMPI_COMM_SET_PML_ADDED(&ompi_mpi_comm_self.comm);
     opal_pointer_array_set_item (&ompi_mpi_communicators, 1, &ompi_mpi_comm_self);
 
-    MEMCHECKER (memset (ompi_mpi_comm_self.c_name, 0, MPI_MAX_OBJECT_NAME));
-    strncpy(ompi_mpi_comm_self.c_name,"MPI_COMM_SELF",strlen("MPI_COMM_SELF")+1);
-    ompi_mpi_comm_self.c_flags |= OMPI_COMM_NAMEISSET;
-    ompi_mpi_comm_self.c_flags |= OMPI_COMM_INTRINSIC;
+    MEMCHECKER (memset (ompi_mpi_comm_self.comm.c_name, 0, MPI_MAX_OBJECT_NAME));
+    strncpy(ompi_mpi_comm_self.comm.c_name,"MPI_COMM_SELF",strlen("MPI_COMM_SELF")+1);
+    ompi_mpi_comm_self.comm.c_flags |= OMPI_COMM_NAMEISSET;
+    ompi_mpi_comm_self.comm.c_flags |= OMPI_COMM_INTRINSIC;
 
     /* We can set MPI_COMM_SELF's keyhash to NULL because it has no
        predefined attributes.  If a user defines an attribute on
        MPI_COMM_SELF, the keyhash will automatically be created. */
-    ompi_mpi_comm_self.c_keyhash = NULL;
+    ompi_mpi_comm_self.comm.c_keyhash = NULL;
 
     /* Setup MPI_COMM_NULL */
     OBJ_CONSTRUCT(&ompi_mpi_comm_null, ompi_communicator_t);
-    ompi_mpi_comm_null.c_local_group  = &ompi_mpi_group_null;
-    ompi_mpi_comm_null.c_remote_group = &ompi_mpi_group_null;
-    OBJ_RETAIN(&ompi_mpi_group_null); 
-    OBJ_RETAIN(&ompi_mpi_group_null);
+    ompi_mpi_comm_null.comm.c_local_group  = &ompi_mpi_group_null.group;
+    ompi_mpi_comm_null.comm.c_remote_group = &ompi_mpi_group_null.group;
+    OBJ_RETAIN(&ompi_mpi_group_null.group); 
+    OBJ_RETAIN(&ompi_mpi_group_null.group);
 
-    ompi_mpi_comm_null.c_contextid    = 2;
-    ompi_mpi_comm_null.c_f_to_c_index = 2;
-    ompi_mpi_comm_null.c_my_rank      = MPI_PROC_NULL;
+    ompi_mpi_comm_null.comm.c_contextid    = 2;
+    ompi_mpi_comm_null.comm.c_f_to_c_index = 2;
+    ompi_mpi_comm_null.comm.c_my_rank      = MPI_PROC_NULL;
 
-    ompi_mpi_comm_null.error_handler  = &ompi_mpi_errors_are_fatal;
-    OBJ_RETAIN( &ompi_mpi_errors_are_fatal );
+    ompi_mpi_comm_null.comm.error_handler  = &ompi_mpi_errors_are_fatal.eh;
+    OBJ_RETAIN( &ompi_mpi_errors_are_fatal.eh );
     opal_pointer_array_set_item (&ompi_mpi_communicators, 2, &ompi_mpi_comm_null);
 
-    MEMCHECKER (memset (ompi_mpi_comm_null.c_name, 0, MPI_MAX_OBJECT_NAME));
-    strncpy(ompi_mpi_comm_null.c_name,"MPI_COMM_NULL",strlen("MPI_COMM_NULL")+1);
-    ompi_mpi_comm_null.c_flags |= OMPI_COMM_NAMEISSET;
-    ompi_mpi_comm_null.c_flags |= OMPI_COMM_INTRINSIC;
+    MEMCHECKER (memset (ompi_mpi_comm_null.comm.c_name, 0, MPI_MAX_OBJECT_NAME));
+    strncpy(ompi_mpi_comm_null.comm.c_name,"MPI_COMM_NULL",strlen("MPI_COMM_NULL")+1);
+    ompi_mpi_comm_null.comm.c_flags |= OMPI_COMM_NAMEISSET;
+    ompi_mpi_comm_null.comm.c_flags |= OMPI_COMM_INTRINSIC;
 
     /* Initialize the parent communicator to MPI_COMM_NULL */
-    ompi_mpi_comm_parent = &ompi_mpi_comm_null;
+    ompi_mpi_comm_parent = &ompi_mpi_comm_null.comm;
     OBJ_RETAIN(&ompi_mpi_comm_null);
-    OBJ_RETAIN(&ompi_mpi_group_null);
-    OBJ_RETAIN(&ompi_mpi_errors_are_fatal);
+    OBJ_RETAIN(&ompi_mpi_group_null.group);
+    OBJ_RETAIN(&ompi_mpi_errors_are_fatal.eh);
 
     /* initialize the comm_reg stuff for multi-threaded comm_cid
        allocation */
@@ -216,7 +217,7 @@ int ompi_comm_finalize(void)
     OBJ_DESTRUCT( &ompi_mpi_comm_world );
 
     /* Shut down the parent communicator, if it exists */
-    if( ompi_mpi_comm_parent != &ompi_mpi_comm_null ) {
+    if( ompi_mpi_comm_parent != &ompi_mpi_comm_null.comm ) {
         /* Note that we pass ompi_mpi_comm_parent here
            (vs. &ompi_mpi_comm_parent) because it is of type
            (ompi_communicator_t*), *NOT* (ompi_communicator_t).  This
diff --git a/ompi/communicator/communicator.h b/ompi/communicator/communicator.h
index 3eb86b6db0..48d8de16d2 100644
--- a/ompi/communicator/communicator.h
+++ b/ompi/communicator/communicator.h
@@ -12,6 +12,7 @@
  *                         All rights reserved.
  * Copyright (c) 2006      Cisco Systems, Inc.  All rights reserved.
  * Copyright (c) 2006-2008 University of Houston.  All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc. All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -104,7 +105,7 @@ struct ompi_communicator_t {
     int c_id_available; /* the currently available Cid for allocation 
                to a child*/
     int c_id_start_index; /* the starting index of the block of cids 
-                 allocated to tthis communicator*/
+                 allocated to this communicator*/
 
     ompi_group_t        *c_local_group;
     ompi_group_t       *c_remote_group;
@@ -156,8 +157,79 @@ struct ompi_communicator_t {
     mca_coll_base_comm_coll_t c_coll;
 };
 typedef struct ompi_communicator_t ompi_communicator_t;
+
+/**
+ * Padded struct to maintain back compatibiltiy.
+ *
+ * The following ompi_predefined_xxx_t structure is used to maintain
+ * backwards binary compatibility for MPI applications compiled
+ * against one version of OMPI library but dynamically linked at
+ * runtime with another.  The issue is between versions the actual
+ * structure may change in size (even between debug and optimized
+ * compilation -- the structure contents change, and therefore the
+ * overall size changes).
+ *
+ * This is problematic with predefined handles because the storage of
+ * the structure ends up being located to an application's BSS.  This
+ * causes problems because if one version has the predefined as size X
+ * and then the application is dynamically linked with a version that
+ * has a size of Y (where X != Y) then the application will
+ * unintentionally overrun the memory initially allocated for the
+ * structure.
+ *
+ * The solution we are using below creates a parent structure
+ * (ompi_predefined_xxx_t) that contains the base structure
+ * (ompi_xxx_t) followed by a character padding that is the size of
+ * the total size we choose to preallocate for the structure minus the
+ * amount used by the base structure.  In this way, we've normalized
+ * the size of each predefined handle across multiple versions and
+ * configurations of Open MPI (e.g., MPI_COMM_WORLD will refer to a
+ * back-end struct that is X bytes long, even if we change the
+ * back-end ompi_communicator_t between version A.B and version C.D in
+ * Open MPI).  When we come close to filling up the the padding we can
+ * add a pointer at the back end of the base structure to point to an
+ * extension of the type.  Or we can just increase the padding and
+ * break backwards binary compatibility.
+ * 
+ * The above method was decided after several failed attempts
+ * described below.
+ *
+ * - Original implementation - suffered that the base structure seemed
+ *   to always change in size between Open MPI versions and/or
+ *   configurations (e.g., optimized vs. debugging build).
+ *
+ * - Convert all predefined handles to run-time-assigned pointers
+ *   (i.e., global variables) - This worked except in cases where an MPI
+ *   application wanted to assign the predefined handle value to a
+ *   global variable -- we could not guarantee to have the global
+ *   variable filled until MPI_INIT was called (recall that MPI
+ *   predefined handles must be assignable before MPI_INIT; e.g.,
+ *   "MPI_Comm foo = MPI_COMM_WORLD").
+ *
+ * - union of struct and padding - Similar to current implementation
+ *   except using a union for the parent.  This worked except in cases
+ *   where the compilers did not support C99 union static initalizers.
+ *   It would have been a pain to convert a bunch of the code to use
+ *   non-static initializers (e.g., MPI datatypes).
+ */
+
+/* Define for the preallocated size of the predefined handle.  
+ * Note that we are using a pointer type as the base memory chunk
+ * size so when the bitness changes the size of the handle changes.
+ * This is done so we don't end up needing a structure that is
+ * incredibly larger than necessary because of the bitness.
+ */
+#define PREDEFINED_COMMUNICATOR_PAD (sizeof(void*) * 96)
+
+struct ompi_predefined_communicator_t {
+    struct ompi_communicator_t comm;
+    char padding[PREDEFINED_COMMUNICATOR_PAD - sizeof(ompi_communicator_t)];
+};
+typedef struct ompi_predefined_communicator_t ompi_predefined_communicator_t;
+
 OMPI_DECLSPEC extern ompi_communicator_t *ompi_mpi_comm_parent;
-OMPI_DECLSPEC extern ompi_communicator_t ompi_mpi_comm_null;
+OMPI_DECLSPEC extern ompi_predefined_communicator_t ompi_mpi_comm_null;
+
 
 
 /**
diff --git a/ompi/datatype/datatype.h b/ompi/datatype/datatype.h
index c9e8927be5..0bf94411b9 100644
--- a/ompi/datatype/datatype.h
+++ b/ompi/datatype/datatype.h
@@ -12,6 +12,7 @@
  *                         All rights reserved.
  * Copyright (c) 2007      Los Alamos National Security, LLC.  All rights
  *                         reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc.  All rights reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -95,15 +96,15 @@ typedef struct dt_type_desc {
  */
 typedef struct ompi_datatype_t {
     opal_object_t      super;    /**< basic superclass */
+    uint16_t           flags;    /**< the flags */
+    uint16_t           id;       /**< data id, normally the index in the data array. */
     size_t             size;     /**< total size in bytes of the memory used by the data if
-                                  * the data is put on a contiguous buffer */
-    uint32_t           align;    /**< data should be aligned to */
+                                      the data is put on a contiguous buffer */
     ptrdiff_t          true_lb;
     ptrdiff_t          true_ub;  /**< the true ub of the data without user defined lb and ub */
     ptrdiff_t          lb;       /**< lower bound in memory */
     ptrdiff_t          ub;       /**< upper bound in memory */
-    uint16_t           flags;    /**< the flags */
-    uint16_t           id;       /**< data id, normally the index in the data array. */
+    uint32_t           align;    /**< data should be aligned to */
     uint32_t           nbElems;  /**< total number of elements inside the datatype */
     uint64_t           bdt_used; /**< which basic datatypes are used in the data description */
 
@@ -124,6 +125,25 @@ typedef struct ompi_datatype_t {
 
 OMPI_DECLSPEC OBJ_CLASS_DECLARATION( ompi_datatype_t );
 
+/**
+ * Padded struct to maintain back compatibiltiy.
+ * See ompi/communicator/communicator.h comments with struct ompi_communicator_t
+ * for full explanation why we chose the following padding construct for predefines.
+ */
+
+/* Using set constant for padding of the DATATYPE handles because the size of
+ * base structure is very close to being the same no matter the bitness.
+ */
+#define PREDEFINED_DATATYPE_PAD (512)
+
+struct ompi_predefined_datatype_t {
+    struct ompi_datatype_t dt;
+    char padding[PREDEFINED_DATATYPE_PAD - sizeof(ompi_datatype_t)];
+};
+
+typedef struct ompi_predefined_datatype_t ompi_predefined_datatype_t;
+
+
 int ompi_ddt_register_params(void);
 OMPI_DECLSPEC int32_t ompi_ddt_init( void );
 OMPI_DECLSPEC int32_t ompi_ddt_finalize( void );
diff --git a/ompi/datatype/dt_create_dup.c b/ompi/datatype/dt_create_dup.c
index d789f9f9c5..1907172ec4 100644
--- a/ompi/datatype/dt_create_dup.c
+++ b/ompi/datatype/dt_create_dup.c
@@ -10,6 +10,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2006 The Regents of the University of California.
  *                         All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc. All rights reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -75,7 +76,7 @@ int32_t ompi_ddt_create_contiguous( int count, const ompi_datatype_t* oldType,
 
     if( 0 == count ) {
         pdt = ompi_ddt_create( 0 );
-        ompi_ddt_add( pdt, &ompi_mpi_datatype_null, 0, 0, 0 );
+        ompi_ddt_add( pdt, &ompi_mpi_datatype_null.dt, 0, 0, 0 );
     } else {
         pdt = ompi_ddt_create( oldType->desc.used + 2 );
         ompi_ddt_add( pdt, oldType, count, 0, (oldType->ub - oldType->lb) );
diff --git a/ompi/datatype/dt_create_indexed.c b/ompi/datatype/dt_create_indexed.c
index ef810cf62d..b67e6116bd 100644
--- a/ompi/datatype/dt_create_indexed.c
+++ b/ompi/datatype/dt_create_indexed.c
@@ -10,6 +10,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2006 The Regents of the University of California.
  *                         All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc. All rights reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -31,7 +32,7 @@ int32_t ompi_ddt_create_indexed( int count, const int* pBlockLength, const int*
 
     if( 0 == count ) {
         *newType = ompi_ddt_create( 0 );
-        ompi_ddt_add( *newType, &ompi_mpi_datatype_null, 0, 0, 0);
+        ompi_ddt_add( *newType, &ompi_mpi_datatype_null.dt, 0, 0, 0);
         return OMPI_SUCCESS;
     }
 
@@ -73,7 +74,7 @@ int32_t ompi_ddt_create_hindexed( int count, const int* pBlockLength, const MPI_
 
     if( 0 == count ) {
         *newType = ompi_ddt_create( 0 );
-        ompi_ddt_add( *newType, &ompi_mpi_datatype_null, 0, 0, 0);
+        ompi_ddt_add( *newType, &ompi_mpi_datatype_null.dt, 0, 0, 0);
         return OMPI_SUCCESS;
     }
 
@@ -114,7 +115,7 @@ int32_t ompi_ddt_create_indexed_block( int count, int bLength, const int* pDisp,
    if( (count == 0) || (bLength == 0) ) {
       *newType = ompi_ddt_create(1);
       if( 0 == count )
-          ompi_ddt_add( *newType, &ompi_mpi_datatype_null, 0, 0, 0 );
+          ompi_ddt_add( *newType, &ompi_mpi_datatype_null.dt, 0, 0, 0 );
       else
           ompi_ddt_add( *newType, oldType, 0, pDisp[0] * extent, extent );
       return OMPI_SUCCESS;
diff --git a/ompi/datatype/dt_create_struct.c b/ompi/datatype/dt_create_struct.c
index 42a43b0e19..241d714360 100644
--- a/ompi/datatype/dt_create_struct.c
+++ b/ompi/datatype/dt_create_struct.c
@@ -10,6 +10,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2006 The Regents of the University of California.
  *                         All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc. All rights reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -31,7 +32,7 @@ int32_t ompi_ddt_create_struct( int count, const int* pBlockLength, const MPI_Ai
 
     if( 0 == count ) {
         *newType = ompi_ddt_create( 0 );
-        ompi_ddt_add( *newType, &ompi_mpi_datatype_null, 0, 0, 0);
+        ompi_ddt_add( *newType, &ompi_mpi_datatype_null.dt, 0, 0, 0);
         return OMPI_SUCCESS;
     }
 
diff --git a/ompi/datatype/dt_create_vector.c b/ompi/datatype/dt_create_vector.c
index 8782285518..5af0525598 100644
--- a/ompi/datatype/dt_create_vector.c
+++ b/ompi/datatype/dt_create_vector.c
@@ -10,6 +10,8 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2006 The Regents of the University of California.
  *                         All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc. All rights reserved.
+
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -35,7 +37,7 @@ int32_t ompi_ddt_create_vector( int count, int bLength, int stride,
 
     if( 0 == count ) {
         *newType = ompi_ddt_create( 0 );
-        ompi_ddt_add( *newType, &ompi_mpi_datatype_null, 0, 0, 0);
+        ompi_ddt_add( *newType, &ompi_mpi_datatype_null.dt, 0, 0, 0);
         return OMPI_SUCCESS;
     }
 
@@ -65,7 +67,7 @@ int32_t ompi_ddt_create_hvector( int count, int bLength, MPI_Aint stride,
 
     if( 0 == count ) {
         *newType = ompi_ddt_create( 0 );
-        ompi_ddt_add( *newType, &ompi_mpi_datatype_null, 0, 0, 0);
+        ompi_ddt_add( *newType, &ompi_mpi_datatype_null.dt, 0, 0, 0);
         return OMPI_SUCCESS;
     }
 
diff --git a/ompi/datatype/dt_match_size.c b/ompi/datatype/dt_match_size.c
index f339fa8310..8fd976ddf6 100644
--- a/ompi/datatype/dt_match_size.c
+++ b/ompi/datatype/dt_match_size.c
@@ -10,6 +10,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2006 The Regents of the University of California.
  *                         All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc. All rights reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -47,5 +48,5 @@ ompi_ddt_match_size( int size, uint16_t datakind, uint16_t datalang )
             return datatype;
         }
     }
-    return &ompi_mpi_datatype_null;
+    return &ompi_mpi_datatype_null.dt;
 }
diff --git a/ompi/datatype/dt_module.c b/ompi/datatype/dt_module.c
index 042b1dde15..1f5fbafe8b 100644
--- a/ompi/datatype/dt_module.c
+++ b/ompi/datatype/dt_module.c
@@ -11,6 +11,7 @@
  * Copyright (c) 2004-2006 The Regents of the University of California.
  *                         All rights reserved.
  * Copyright (c) 2007      Cisco Systems, Inc.  All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc.  All rights reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -53,37 +54,35 @@ int ompi_ddt_dfd = -1;
  * correct information. This macro should be used for all composed types.
  */
 #define INIT_BASIC_TYPE( TYPE, NAME )                                        \
-    { BASEOBJ_DATA, 0/*size*/, 0 /*align*/, 0/*true_lb*/, 0/*true_ub*/,      \
-            0/*lb*/, 0/*ub*/, DT_FLAG_PREDEFINED, TYPE, 1,                   \
+    { BASEOBJ_DATA, DT_FLAG_PREDEFINED, TYPE, 0/*size*/,                     \
+            0/*true_lb*/, 0/*true_ub*/, 0/*lb*/, 0/*ub*/, 0 /* align */, 1,  \
       (((uint64_t)1)<<(TYPE)), EMPTY_DATA(NAME) }
 
-#define INIT_BASIC_DATA( TYPE, ALIGN, NAME, FLAGS )                                \
-    { BASEOBJ_DATA, sizeof(TYPE), ALIGN, 0, sizeof(TYPE),                          \
-            0, sizeof(TYPE), DT_FLAG_BASIC | (FLAGS),                              \
-            DT_##NAME, 1, (((uint64_t)1)<<(DT_##NAME)), EMPTY_DATA(NAME) }
+#define INIT_BASIC_DATA( TYPE, ALIGN, NAME, FLAGS )                          \
+    { BASEOBJ_DATA, DT_FLAG_BASIC | (FLAGS), DT_##NAME, sizeof(TYPE), 0,     \
+            sizeof(TYPE), 0, sizeof(TYPE), (ALIGN),                          \
+            1, (((uint64_t)1)<<(DT_##NAME)), EMPTY_DATA(NAME) }
 
-#define INIT_BASIC_DATA_WITH_NAME( TYPE, ALIGN, INTERNAL_NAME, NAME, FLAGS )       \
-    { BASEOBJ_DATA, sizeof(TYPE), ALIGN, 0, sizeof(TYPE),                          \
-            0, sizeof(TYPE), DT_FLAG_BASIC | (FLAGS),                              \
-            DT_##INTERNAL_NAME, 1, (((uint64_t)1)<<(DT_##INTERNAL_NAME)),          \
-            EMPTY_DATA(NAME) }
+#define INIT_BASIC_DATA_WITH_NAME( TYPE, ALIGN, INTERNAL_NAME, NAME, FLAGS )  \
+    { BASEOBJ_DATA, DT_FLAG_BASIC | (FLAGS),DT_##INTERNAL_NAME, sizeof(TYPE), \
+            0, sizeof(TYPE), 0, sizeof(TYPE), (ALIGN),                        \
+            1, (((uint64_t)1)<<(DT_##INTERNAL_NAME)), EMPTY_DATA(NAME) }
 
 #define INIT_UNAVAILABLE_DATA( NAME )                                           \
-    { BASEOBJ_DATA, 0, 0, 0, 0, 0, 0, DT_FLAG_UNAVAILABLE | DT_FLAG_PREDEFINED, \
-            DT_UNAVAILABLE, 1, 0, EMPTY_DATA( "UNAVAILABLE_" # NAME ) }
+    { BASEOBJ_DATA, DT_FLAG_UNAVAILABLE | DT_FLAG_PREDEFINED, DT_UNAVAILABLE, 0,\
+            0, 0, 0, 0, 0, 1, 0, EMPTY_DATA( "UNAVAILABLE_" # NAME ) }
 
 /* The upper bound and the true UB are set to the size of the datatype.
  * If it's not the case then they should be modified in the initialization
  * function.
  */
 #if OMPI_WANT_F77_BINDINGS
-#define INIT_BASIC_FORTRAN_TYPE( TYPE, NAME, SIZE, ALIGN, FLAGS )                                  \
-    { BASEOBJ_DATA, SIZE, ALIGN, 0/*true_lb*/, SIZE/*true_ub*/,                                    \
-            0/*lb*/, SIZE/*ub*/,                                                                   \
-            DT_FLAG_BASIC | DT_FLAG_DATA_FORTRAN | (FLAGS), \
-            (TYPE), 1, (((uint64_t)1)<<(TYPE)), EMPTY_DATA(NAME) }
+#define INIT_BASIC_FORTRAN_TYPE( TYPE, NAME, SIZE, ALIGN, FLAGS )             \
+    { BASEOBJ_DATA, DT_FLAG_BASIC | DT_FLAG_DATA_FORTRAN | (FLAGS),           \
+            (TYPE), SIZE, 0/*true_lb*/, SIZE/*true_ub*/, 0/*lb*/, SIZE/*ub*/, \
+            (ALIGN), 1, (((uint64_t)1)<<(TYPE)), EMPTY_DATA(NAME) }
 #else
-#define INIT_BASIC_FORTRAN_TYPE( TYPE, NAME, SIZE, ALIGN, FLAGS )                                          \
+#define INIT_BASIC_FORTRAN_TYPE( TYPE, NAME, SIZE, ALIGN, FLAGS )             \
     INIT_BASIC_TYPE( TYPE, NAME )
 #endif  /* OMPI_WANT_F77_BINDINGS */
 
@@ -93,170 +92,169 @@ int ompi_ddt_dfd = -1;
  */
 int32_t ompi_ddt_number_of_predefined_data = 0;
 
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_datatype_null =
-    { BASEOBJ_DATA, 0, 0, 0, 0,
-      0, 0, DT_FLAG_PREDEFINED, 0, 1,
-      ((long long)0), EMPTY_DATA(DATATYPE_NULL) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_datatype_null = {
+    { BASEOBJ_DATA, DT_FLAG_PREDEFINED, 0, 0, 0, 0,
+      0, 0, 0, 1, ((long long)0), EMPTY_DATA(DATATYPE_NULL) }};
 
 OMPI_DECLSPEC ompi_datatype_t ompi_mpi_loop = INIT_BASIC_TYPE( DT_LOOP, LOOP );
 OMPI_DECLSPEC ompi_datatype_t ompi_mpi_end_loop = INIT_BASIC_TYPE( DT_END_LOOP, END_LOOP );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_ub = INIT_BASIC_TYPE( DT_UB, UB );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_lb = INIT_BASIC_TYPE( DT_LB, LB );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_char = INIT_BASIC_DATA( char, OMPI_ALIGNMENT_CHAR, CHAR, DT_FLAG_DATA_C );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_character = INIT_BASIC_DATA( char, OMPI_ALIGNMENT_CHAR, CHARACTER, DT_FLAG_DATA_FORTRAN );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_unsigned_char = INIT_BASIC_DATA( unsigned char, OMPI_ALIGNMENT_CHAR, UNSIGNED_CHAR, DT_FLAG_DATA_C );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_signed_char = INIT_BASIC_DATA( signed char, OMPI_ALIGNMENT_CHAR, SIGNED_CHAR, DT_FLAG_DATA_C | DT_FLAG_DATA_INT );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_byte = INIT_BASIC_DATA( unsigned char, OMPI_ALIGNMENT_CHAR, BYTE, DT_FLAG_DATA_C | DT_FLAG_DATA_INT );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_short = INIT_BASIC_DATA( short, OMPI_ALIGNMENT_SHORT, SHORT, DT_FLAG_DATA_C | DT_FLAG_DATA_INT );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_unsigned_short = INIT_BASIC_DATA( unsigned short, OMPI_ALIGNMENT_SHORT, UNSIGNED_SHORT, DT_FLAG_DATA_C | DT_FLAG_DATA_INT );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_int = INIT_BASIC_DATA( int, OMPI_ALIGNMENT_INT, INT, DT_FLAG_DATA_C | DT_FLAG_DATA_INT );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_unsigned = INIT_BASIC_DATA_WITH_NAME( unsigned int, OMPI_ALIGNMENT_INT, UNSIGNED_INT, UNSIGNED, DT_FLAG_DATA_C | DT_FLAG_DATA_INT );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_long = INIT_BASIC_DATA( long, OMPI_ALIGNMENT_LONG, LONG, DT_FLAG_DATA_C | DT_FLAG_DATA_INT );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_unsigned_long = INIT_BASIC_DATA( unsigned long, OMPI_ALIGNMENT_LONG, UNSIGNED_LONG, DT_FLAG_DATA_C | DT_FLAG_DATA_INT );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_ub = { INIT_BASIC_TYPE( DT_UB, UB) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_lb = { INIT_BASIC_TYPE( DT_LB, LB) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_char = { INIT_BASIC_DATA( char, OMPI_ALIGNMENT_CHAR, CHAR, DT_FLAG_DATA_C ) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_character = { INIT_BASIC_DATA( char, OMPI_ALIGNMENT_CHAR, CHARACTER, DT_FLAG_DATA_FORTRAN) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_unsigned_char = { INIT_BASIC_DATA( unsigned char, OMPI_ALIGNMENT_CHAR, UNSIGNED_CHAR, DT_FLAG_DATA_C) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_signed_char = { INIT_BASIC_DATA( signed char, OMPI_ALIGNMENT_CHAR, SIGNED_CHAR, DT_FLAG_DATA_C | DT_FLAG_DATA_INT) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_byte = { INIT_BASIC_DATA( unsigned char, OMPI_ALIGNMENT_CHAR, BYTE, DT_FLAG_DATA_C | DT_FLAG_DATA_INT ) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_short = { INIT_BASIC_DATA( short, OMPI_ALIGNMENT_SHORT, SHORT, DT_FLAG_DATA_C | DT_FLAG_DATA_INT) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_unsigned_short = { INIT_BASIC_DATA( unsigned short, OMPI_ALIGNMENT_SHORT, UNSIGNED_SHORT, DT_FLAG_DATA_C | DT_FLAG_DATA_INT) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_int = { INIT_BASIC_DATA( int, OMPI_ALIGNMENT_INT, INT, DT_FLAG_DATA_C | DT_FLAG_DATA_INT) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_unsigned = { INIT_BASIC_DATA_WITH_NAME( unsigned int, OMPI_ALIGNMENT_INT, UNSIGNED_INT, UNSIGNED, DT_FLAG_DATA_C | DT_FLAG_DATA_INT) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_long = { INIT_BASIC_DATA( long, OMPI_ALIGNMENT_LONG, LONG, DT_FLAG_DATA_C | DT_FLAG_DATA_INT) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_unsigned_long = { INIT_BASIC_DATA( unsigned long, OMPI_ALIGNMENT_LONG, UNSIGNED_LONG, DT_FLAG_DATA_C | DT_FLAG_DATA_INT) };
 #if HAVE_LONG_LONG
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_long_long_int = INIT_BASIC_DATA_WITH_NAME( long long, OMPI_ALIGNMENT_LONG_LONG, LONG_LONG_INT, LONG_LONG, DT_FLAG_DATA_C | DT_FLAG_DATA_INT );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_unsigned_long_long = INIT_BASIC_DATA( unsigned long long, OMPI_ALIGNMENT_LONG_LONG, UNSIGNED_LONG_LONG, DT_FLAG_DATA_C | DT_FLAG_DATA_INT );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_long_long_int = { INIT_BASIC_DATA_WITH_NAME( long long, OMPI_ALIGNMENT_LONG_LONG, LONG_LONG_INT, LONG_LONG, DT_FLAG_DATA_C | DT_FLAG_DATA_INT) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_unsigned_long_long = { INIT_BASIC_DATA( unsigned long long, OMPI_ALIGNMENT_LONG_LONG, UNSIGNED_LONG_LONG, DT_FLAG_DATA_C | DT_FLAG_DATA_INT) };
 #else
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_long_long_int = INIT_UNAVAILABLE_DATA( LONG_LONG_INT );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_unsigned_long_long = INIT_UNAVAILABLE_DATA( UNIGNED_LONG_LONG );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_long_long_int = { INIT_UNAVAILABLE_DATA( LONG_LONG_INT) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_unsigned_long_long = { INIT_UNAVAILABLE_DATA( UNIGNED_LONG_LONG) };
 #endif  /* HAVE_LONG_LONG */
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_float = INIT_BASIC_DATA( float, OMPI_ALIGNMENT_FLOAT, FLOAT, DT_FLAG_DATA_C | DT_FLAG_DATA_FLOAT );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_double = INIT_BASIC_DATA( double, OMPI_ALIGNMENT_DOUBLE, DOUBLE, DT_FLAG_DATA_C | DT_FLAG_DATA_FLOAT );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_float = { INIT_BASIC_DATA( float, OMPI_ALIGNMENT_FLOAT, FLOAT, DT_FLAG_DATA_C | DT_FLAG_DATA_FLOAT) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_double = { INIT_BASIC_DATA( double, OMPI_ALIGNMENT_DOUBLE, DOUBLE, DT_FLAG_DATA_C | DT_FLAG_DATA_FLOAT) };
 #if HAVE_LONG_DOUBLE
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_long_double = INIT_BASIC_DATA( long double, OMPI_ALIGNMENT_LONG_DOUBLE, LONG_DOUBLE, DT_FLAG_DATA_C | DT_FLAG_DATA_FLOAT );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_long_double = { INIT_BASIC_DATA( long double, OMPI_ALIGNMENT_LONG_DOUBLE, LONG_DOUBLE, DT_FLAG_DATA_C | DT_FLAG_DATA_FLOAT) };
 #else
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_long_double = INIT_UNAVAILABLE_DATA( LONG_DOUBLE );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_long_double = { INIT_UNAVAILABLE_DATA( LONG_DOUBLE) };
 #endif  /* HAVE_LONG_DOUBLE */
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_packed = INIT_BASIC_DATA( char, OMPI_ALIGNMENT_CHAR, PACKED, 0 );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_packed = { INIT_BASIC_DATA( char, OMPI_ALIGNMENT_CHAR, PACKED, 0) };
 #if OMPI_ALIGNMENT_WCHAR != 0
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_wchar = INIT_BASIC_DATA( wchar_t, OMPI_ALIGNMENT_WCHAR, WCHAR, DT_FLAG_DATA_C );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_wchar = { INIT_BASIC_DATA( wchar_t, OMPI_ALIGNMENT_WCHAR, WCHAR, DT_FLAG_DATA_C) };
 #else
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_wchar = INIT_UNAVAILABLE_DATA( WCHAR );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_wchar = { INIT_UNAVAILABLE_DATA( WCHAR) };
 #endif  /* OMPI_ALIGNMENT_WCHAR */
 
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_cxx_bool = INIT_BASIC_DATA( bool, OMPI_ALIGNMENT_CXX_BOOL, CXX_BOOL, DT_FLAG_DATA_CPP );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_logic = INIT_BASIC_FORTRAN_TYPE( DT_LOGIC, LOGIC, OMPI_SIZEOF_FORTRAN_LOGICAL, OMPI_ALIGNMENT_FORTRAN_LOGICAL, 0 );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_integer = INIT_BASIC_FORTRAN_TYPE( DT_INTEGER, INTEGER, OMPI_SIZEOF_FORTRAN_INTEGER, OMPI_ALIGNMENT_FORTRAN_INTEGER, DT_FLAG_DATA_INT );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_real = INIT_BASIC_FORTRAN_TYPE( DT_REAL, REAL, OMPI_SIZEOF_FORTRAN_REAL, OMPI_ALIGNMENT_FORTRAN_REAL, DT_FLAG_DATA_FLOAT );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_dblprec = INIT_BASIC_FORTRAN_TYPE( DT_DBLPREC, DOUBLE_PRECISION, OMPI_SIZEOF_FORTRAN_DOUBLE_PRECISION, OMPI_ALIGNMENT_FORTRAN_DOUBLE_PRECISION, DT_FLAG_DATA_FLOAT );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_cxx_bool = { INIT_BASIC_DATA( bool, OMPI_ALIGNMENT_CXX_BOOL, CXX_BOOL, DT_FLAG_DATA_CPP) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_logic = { INIT_BASIC_FORTRAN_TYPE( DT_LOGIC, LOGIC, OMPI_SIZEOF_FORTRAN_LOGICAL, OMPI_ALIGNMENT_FORTRAN_LOGICAL, 0) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_integer = { INIT_BASIC_FORTRAN_TYPE( DT_INTEGER, INTEGER, OMPI_SIZEOF_FORTRAN_INTEGER, OMPI_ALIGNMENT_FORTRAN_INTEGER, DT_FLAG_DATA_INT) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_real = { INIT_BASIC_FORTRAN_TYPE( DT_REAL, REAL, OMPI_SIZEOF_FORTRAN_REAL, OMPI_ALIGNMENT_FORTRAN_REAL, DT_FLAG_DATA_FLOAT) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_dblprec = { INIT_BASIC_FORTRAN_TYPE( DT_DBLPREC, DOUBLE_PRECISION, OMPI_SIZEOF_FORTRAN_DOUBLE_PRECISION, OMPI_ALIGNMENT_FORTRAN_DOUBLE_PRECISION, DT_FLAG_DATA_FLOAT) };
 
 #if HAVE_LONG_DOUBLE
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_ldblcplex = INIT_BASIC_DATA( ompi_complex_long_double_t, OMPI_ALIGNMENT_LONG_DOUBLE, COMPLEX_LONG_DOUBLE, DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_COMPLEX );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_ldblcplex = { INIT_BASIC_DATA( ompi_complex_long_double_t, OMPI_ALIGNMENT_LONG_DOUBLE, COMPLEX_LONG_DOUBLE, DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_COMPLEX) };
 #else
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_ldblcplex = INIT_UNAVAILABLE_DATA( COMPLEX_LONG_DOUBLE );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_ldblcplex = { INIT_UNAVAILABLE_DATA( COMPLEX_LONG_DOUBLE) };
 #endif  /* HAVE_LONG_DOUBLE */
 
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_cplex = INIT_BASIC_DATA( ompi_complex_float_t, OMPI_ALIGNMENT_FLOAT, COMPLEX_FLOAT, DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_COMPLEX );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_dblcplex = INIT_BASIC_DATA( ompi_complex_double_t, OMPI_ALIGNMENT_DOUBLE, COMPLEX_DOUBLE, DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_COMPLEX );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_float_int = INIT_BASIC_TYPE( DT_FLOAT_INT, FLOAT_INT );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_double_int = INIT_BASIC_TYPE( DT_DOUBLE_INT, DOUBLE_INT );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_cplex = { INIT_BASIC_DATA( ompi_complex_float_t, OMPI_ALIGNMENT_FLOAT, COMPLEX_FLOAT, DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_COMPLEX) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_dblcplex = { INIT_BASIC_DATA( ompi_complex_double_t, OMPI_ALIGNMENT_DOUBLE, COMPLEX_DOUBLE, DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_COMPLEX) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_float_int = { INIT_BASIC_TYPE( DT_FLOAT_INT, FLOAT_INT) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_double_int = { INIT_BASIC_TYPE( DT_DOUBLE_INT, DOUBLE_INT) };
 #if HAVE_LONG_DOUBLE
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_longdbl_int = INIT_BASIC_TYPE( DT_LONG_DOUBLE_INT, LONG_DOUBLE_INT );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_longdbl_int = { INIT_BASIC_TYPE( DT_LONG_DOUBLE_INT, LONG_DOUBLE_INT) };
 #else
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_longdbl_int = INIT_UNAVAILABLE_DATA( LONG_DOUBLE_INT );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_longdbl_int = { INIT_UNAVAILABLE_DATA( LONG_DOUBLE_INT) };
 #endif  /* HAVE_LONG_DOUBLE */
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_long_int = INIT_BASIC_TYPE( DT_LONG_INT, LONG_INT );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_short_int = INIT_BASIC_TYPE( DT_SHORT_INT, SHORT_INT );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_long_int = { INIT_BASIC_TYPE( DT_LONG_INT, LONG_INT) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_short_int = { INIT_BASIC_TYPE( DT_SHORT_INT, SHORT_INT) };
 
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_2int = INIT_BASIC_TYPE( DT_2INT, 2INT );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_2real = INIT_BASIC_TYPE( DT_2REAL, 2REAL );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_2dblprec = INIT_BASIC_TYPE( DT_2DBLPREC, 2DBLPREC );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_2integer = INIT_BASIC_TYPE( DT_2INTEGER, 2INTEGER );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_2int = { INIT_BASIC_TYPE( DT_2INT, 2INT) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_2real = { INIT_BASIC_TYPE( DT_2REAL, 2REAL) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_2dblprec = { INIT_BASIC_TYPE( DT_2DBLPREC, 2DBLPREC) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_2integer = { INIT_BASIC_TYPE( DT_2INTEGER, 2INTEGER) };
 
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_cxx_cplex = INIT_BASIC_DATA( ompi_complex_float_t, OMPI_ALIGNMENT_FLOAT, COMPLEX_FLOAT, DT_FLAG_DATA_CPP | DT_FLAG_DATA_COMPLEX );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_cxx_dblcplex = INIT_BASIC_DATA( ompi_complex_double_t, OMPI_ALIGNMENT_DOUBLE, COMPLEX_DOUBLE, DT_FLAG_DATA_CPP | DT_FLAG_DATA_COMPLEX );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_cxx_cplex = { INIT_BASIC_DATA( ompi_complex_float_t, OMPI_ALIGNMENT_FLOAT, COMPLEX_FLOAT, DT_FLAG_DATA_CPP | DT_FLAG_DATA_COMPLEX) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_cxx_dblcplex = { INIT_BASIC_DATA( ompi_complex_double_t, OMPI_ALIGNMENT_DOUBLE, COMPLEX_DOUBLE, DT_FLAG_DATA_CPP | DT_FLAG_DATA_COMPLEX) };
 #if HAVE_LONG_DOUBLE
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_cxx_ldblcplex = INIT_BASIC_DATA( ompi_complex_long_double_t, OMPI_ALIGNMENT_LONG_DOUBLE, COMPLEX_LONG_DOUBLE, DT_FLAG_DATA_CPP | DT_FLAG_DATA_COMPLEX );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_cxx_ldblcplex = { INIT_BASIC_DATA( ompi_complex_long_double_t, OMPI_ALIGNMENT_LONG_DOUBLE, COMPLEX_LONG_DOUBLE, DT_FLAG_DATA_CPP | DT_FLAG_DATA_COMPLEX) };
 #else
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_cxx_ldblcplex = INIT_UNAVAILABLE_DATA( COMPLEX_LONG_DOUBLE );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_cxx_ldblcplex = { INIT_UNAVAILABLE_DATA( COMPLEX_LONG_DOUBLE) };
 #endif  /* HAVE_LONG_DOUBLE */
 
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_2cplex = INIT_BASIC_TYPE( DT_2COMPLEX, 2COMPLEX );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_2dblcplex = INIT_BASIC_TYPE( DT_2DOUBLE_COMPLEX, 2DOUBLE_COMPLEX );
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_unavailable = INIT_UNAVAILABLE_DATA( UNAVAILABLE );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_2cplex = { INIT_BASIC_TYPE( DT_2COMPLEX, 2COMPLEX) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_2dblcplex = { INIT_BASIC_TYPE( DT_2DOUBLE_COMPLEX, 2DOUBLE_COMPLEX) };
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_unavailable = { INIT_UNAVAILABLE_DATA( UNAVAILABLE) };
 
 #if OMPI_HAVE_FORTRAN_LOGICAL1
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_logical1 = INIT_BASIC_FORTRAN_TYPE( DT_LOGIC, LOGICAL1, OMPI_SIZEOF_FORTRAN_LOGICAL1, OMPI_ALIGNMENT_FORTRAN_LOGICAL1, 0 );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_logical1 = { INIT_BASIC_FORTRAN_TYPE( DT_LOGIC, LOGICAL1, OMPI_SIZEOF_FORTRAN_LOGICAL1, OMPI_ALIGNMENT_FORTRAN_LOGICAL1, 0) };
 #else
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_logical1 = INIT_UNAVAILABLE_DATA( LOGICAL1 );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_logical1 = { INIT_UNAVAILABLE_DATA( LOGICAL1) };
 #endif  /* OMPI_HAVE_FORTRAN_LOGICAL1 */
 #if OMPI_HAVE_FORTRAN_LOGICAL2
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_logical2 = INIT_BASIC_FORTRAN_TYPE( DT_LOGIC, LOGICAL2, OMPI_SIZEOF_FORTRAN_LOGICAL2, OMPI_ALIGNMENT_FORTRAN_LOGICAL2, 0 );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_logical2 = { INIT_BASIC_FORTRAN_TYPE( DT_LOGIC, LOGICAL2, OMPI_SIZEOF_FORTRAN_LOGICAL2, OMPI_ALIGNMENT_FORTRAN_LOGICAL2, 0) };
 #else
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_logical2 = INIT_UNAVAILABLE_DATA( LOGICAL2 );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_logical2 = { INIT_UNAVAILABLE_DATA( LOGICAL2) };
 #endif  /* OMPI_HAVE_FORTRAN_LOGICAL2 */
 #if OMPI_HAVE_FORTRAN_LOGICAL4
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_logical4 = INIT_BASIC_FORTRAN_TYPE( DT_LOGIC, LOGICAL4, OMPI_SIZEOF_FORTRAN_LOGICAL4, OMPI_ALIGNMENT_FORTRAN_LOGICAL4, 0 );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_logical4 = { INIT_BASIC_FORTRAN_TYPE( DT_LOGIC, LOGICAL4, OMPI_SIZEOF_FORTRAN_LOGICAL4, OMPI_ALIGNMENT_FORTRAN_LOGICAL4, 0) };
 #else
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_logical4 = INIT_UNAVAILABLE_DATA( LOGICAL4 );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_logical4 = { INIT_UNAVAILABLE_DATA( LOGICAL4) };
 #endif  /* OMPI_HAVE_FORTRAN_LOGICAL4 */
 #if OMPI_HAVE_FORTRAN_LOGICAL8
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_logical8 = INIT_BASIC_FORTRAN_TYPE( DT_LOGIC, LOGICAL8, OMPI_SIZEOF_FORTRAN_LOGICAL8, OMPI_ALIGNMENT_FORTRAN_LOGICAL8, 0 );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_logical8 = { INIT_BASIC_FORTRAN_TYPE( DT_LOGIC, LOGICAL8, OMPI_SIZEOF_FORTRAN_LOGICAL8, OMPI_ALIGNMENT_FORTRAN_LOGICAL8, 0) };
 #else
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_logical8 = INIT_UNAVAILABLE_DATA( LOGICAL8 );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_logical8 = { INIT_UNAVAILABLE_DATA( LOGICAL8) };
 #endif  /* OMPI_HAVE_FORTRAN_LOGICAL8 */
 
 #if OMPI_HAVE_FORTRAN_REAL2
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_real2 = INIT_BASIC_FORTRAN_TYPE( DT_FLOAT, REAL2, OMPI_SIZEOF_FORTRAN_REAL2, OMPI_ALIGNMENT_FORTRAN_REAL2, DT_FLAG_DATA_FLOAT );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_real2 = { INIT_BASIC_FORTRAN_TYPE( DT_FLOAT, REAL2, OMPI_SIZEOF_FORTRAN_REAL2, OMPI_ALIGNMENT_FORTRAN_REAL2, DT_FLAG_DATA_FLOAT) };
 #else
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_real2 = INIT_UNAVAILABLE_DATA( REAL2 );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_real2 = { INIT_UNAVAILABLE_DATA( REAL2) };
 #endif
 #if OMPI_HAVE_FORTRAN_REAL4
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_real4 = INIT_BASIC_FORTRAN_TYPE( DT_FLOAT, REAL4, OMPI_SIZEOF_FORTRAN_REAL4, OMPI_ALIGNMENT_FORTRAN_REAL4, DT_FLAG_DATA_FLOAT );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_real4 = { INIT_BASIC_FORTRAN_TYPE( DT_FLOAT, REAL4, OMPI_SIZEOF_FORTRAN_REAL4, OMPI_ALIGNMENT_FORTRAN_REAL4, DT_FLAG_DATA_FLOAT) };
 #else
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_real4 = INIT_UNAVAILABLE_DATA( REAL4 );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_real4 = { INIT_UNAVAILABLE_DATA( REAL4) };
 #endif
 #if OMPI_HAVE_FORTRAN_REAL8
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_real8 = INIT_BASIC_FORTRAN_TYPE( DT_DOUBLE, REAL8, OMPI_SIZEOF_FORTRAN_REAL8, OMPI_ALIGNMENT_FORTRAN_REAL8, DT_FLAG_DATA_FLOAT );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_real8 = { INIT_BASIC_FORTRAN_TYPE( DT_DOUBLE, REAL8, OMPI_SIZEOF_FORTRAN_REAL8, OMPI_ALIGNMENT_FORTRAN_REAL8, DT_FLAG_DATA_FLOAT) };
 #else
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_real8 = INIT_UNAVAILABLE_DATA( REAL8 );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_real8 = { INIT_UNAVAILABLE_DATA( REAL8) };
 #endif
 #if OMPI_HAVE_FORTRAN_REAL16 && OMPI_REAL16_MATCHES_C
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_real16 = INIT_BASIC_FORTRAN_TYPE( DT_LONG_DOUBLE, REAL16, OMPI_SIZEOF_FORTRAN_REAL16, OMPI_ALIGNMENT_FORTRAN_REAL16, DT_FLAG_DATA_FLOAT );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_real16 = { INIT_BASIC_FORTRAN_TYPE( DT_LONG_DOUBLE, REAL16, OMPI_SIZEOF_FORTRAN_REAL16, OMPI_ALIGNMENT_FORTRAN_REAL16, DT_FLAG_DATA_FLOAT) };
 #else
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_real16 = INIT_UNAVAILABLE_DATA( REAL16 );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_real16 = { INIT_UNAVAILABLE_DATA( REAL16) };
 #endif
 
 #if OMPI_HAVE_FORTRAN_INTEGER1
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_integer1 = INIT_BASIC_FORTRAN_TYPE( DT_CHAR, INTEGER1, OMPI_SIZEOF_FORTRAN_INTEGER1, OMPI_ALIGNMENT_FORTRAN_INTEGER1, DT_FLAG_DATA_INT );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_integer1 = { INIT_BASIC_FORTRAN_TYPE( DT_CHAR, INTEGER1, OMPI_SIZEOF_FORTRAN_INTEGER1, OMPI_ALIGNMENT_FORTRAN_INTEGER1, DT_FLAG_DATA_INT) };
 #else
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_integer1 = INIT_UNAVAILABLE_DATA( INTEGER1 );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_integer1 = { INIT_UNAVAILABLE_DATA( INTEGER1) };
 #endif
 #if OMPI_HAVE_FORTRAN_INTEGER2
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_integer2 = INIT_BASIC_FORTRAN_TYPE( DT_SHORT, INTEGER2, OMPI_SIZEOF_FORTRAN_INTEGER2, OMPI_ALIGNMENT_FORTRAN_INTEGER2, DT_FLAG_DATA_INT );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_integer2 = { INIT_BASIC_FORTRAN_TYPE( DT_SHORT, INTEGER2, OMPI_SIZEOF_FORTRAN_INTEGER2, OMPI_ALIGNMENT_FORTRAN_INTEGER2, DT_FLAG_DATA_INT) };
 #else
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_integer2 = INIT_UNAVAILABLE_DATA( INTEGER2 );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_integer2 = { INIT_UNAVAILABLE_DATA( INTEGER2) };
 #endif
 #if OMPI_HAVE_FORTRAN_INTEGER4
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_integer4 = INIT_BASIC_FORTRAN_TYPE( DT_INT, INTEGER4, OMPI_SIZEOF_FORTRAN_INTEGER4, OMPI_ALIGNMENT_FORTRAN_INTEGER4, DT_FLAG_DATA_INT );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_integer4 = { INIT_BASIC_FORTRAN_TYPE( DT_INT, INTEGER4, OMPI_SIZEOF_FORTRAN_INTEGER4, OMPI_ALIGNMENT_FORTRAN_INTEGER4, DT_FLAG_DATA_INT) };
 #else
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_integer4 = INIT_UNAVAILABLE_DATA( INTEGER4 );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_integer4 = { INIT_UNAVAILABLE_DATA( INTEGER4) };
 #endif
 #if OMPI_HAVE_FORTRAN_INTEGER8
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_integer8 = INIT_BASIC_FORTRAN_TYPE( DT_LONG_LONG_INT, INTEGER8, OMPI_SIZEOF_FORTRAN_INTEGER8, OMPI_ALIGNMENT_FORTRAN_INTEGER8, DT_FLAG_DATA_INT );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_integer8 = { INIT_BASIC_FORTRAN_TYPE( DT_LONG_LONG_INT, INTEGER8, OMPI_SIZEOF_FORTRAN_INTEGER8, OMPI_ALIGNMENT_FORTRAN_INTEGER8, DT_FLAG_DATA_INT) };
 #else
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_integer8 = INIT_UNAVAILABLE_DATA( INTEGER8 );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_integer8 = { INIT_UNAVAILABLE_DATA( INTEGER8) };
 #endif
 #if OMPI_HAVE_FORTRAN_INTEGER16
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_integer16 = INIT_BASIC_FORTRAN_TYPE( DT_LONG_LONG_INT, INTEGER16, OMPI_SIZEOF_FORTRAN_INTEGER16, OMPI_ALIGNMENT_FORTRAN_INTEGER16, DT_FLAG_DATA_INT );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_integer16 = { INIT_BASIC_FORTRAN_TYPE( DT_LONG_LONG_INT, INTEGER16, OMPI_SIZEOF_FORTRAN_INTEGER16, OMPI_ALIGNMENT_FORTRAN_INTEGER16, DT_FLAG_DATA_INT) };
 #else
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_integer16 = INIT_UNAVAILABLE_DATA( INTEGER16 );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_integer16 = { INIT_UNAVAILABLE_DATA( INTEGER16) };
 #endif
 
 #if OMPI_HAVE_FORTRAN_REAL4 && OMPI_HAVE_FORTRAN_COMPLEX8
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_complex8 = INIT_BASIC_FORTRAN_TYPE( DT_COMPLEX_FLOAT, COMPLEX8, OMPI_SIZEOF_FORTRAN_COMPLEX, OMPI_ALIGNMENT_FORTRAN_REAL, DT_FLAG_DATA_COMPLEX );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_complex8 = { INIT_BASIC_FORTRAN_TYPE( DT_COMPLEX_FLOAT, COMPLEX8, OMPI_SIZEOF_FORTRAN_COMPLEX, OMPI_ALIGNMENT_FORTRAN_REAL, DT_FLAG_DATA_COMPLEX) };
 #else
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_complex8 = INIT_UNAVAILABLE_DATA( COMPLEX8 );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_complex8 = { INIT_UNAVAILABLE_DATA( COMPLEX8) };
 #endif
 #if OMPI_HAVE_FORTRAN_REAL8 && OMPI_HAVE_FORTRAN_COMPLEX16
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_complex16 = INIT_BASIC_FORTRAN_TYPE( DT_COMPLEX_DOUBLE, COMPLEX16, OMPI_SIZEOF_FORTRAN_COMPLEX16, OMPI_ALIGNMENT_FORTRAN_COMPLEX16, DT_FLAG_DATA_COMPLEX );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_complex16 = { INIT_BASIC_FORTRAN_TYPE( DT_COMPLEX_DOUBLE, COMPLEX16, OMPI_SIZEOF_FORTRAN_COMPLEX16, OMPI_ALIGNMENT_FORTRAN_COMPLEX16, DT_FLAG_DATA_COMPLEX) };
 #else
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_complex16 = INIT_UNAVAILABLE_DATA( COMPLEX16 );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_complex16 = { INIT_UNAVAILABLE_DATA( COMPLEX16) };
 #endif
 #if OMPI_HAVE_FORTRAN_REAL16 && OMPI_HAVE_FORTRAN_COMPLEX32 && OMPI_REAL16_MATCHES_C
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_complex32 = INIT_BASIC_FORTRAN_TYPE( DT_COMPLEX_LONG_DOUBLE, COMPLEX32, OMPI_SIZEOF_FORTRAN_COMPLEX32, OMPI_ALIGNMENT_FORTRAN_COMPLEX32, DT_FLAG_DATA_COMPLEX );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_complex32 = { INIT_BASIC_FORTRAN_TYPE( DT_COMPLEX_LONG_DOUBLE, COMPLEX32, OMPI_SIZEOF_FORTRAN_COMPLEX32, OMPI_ALIGNMENT_FORTRAN_COMPLEX32, DT_FLAG_DATA_COMPLEX) };
 #else
-OMPI_DECLSPEC ompi_datatype_t ompi_mpi_complex32 = INIT_UNAVAILABLE_DATA( COMPLEX32 );
+OMPI_DECLSPEC ompi_predefined_datatype_t ompi_mpi_complex32 = { INIT_UNAVAILABLE_DATA( COMPLEX32) };
 #endif
 
 /*
@@ -266,46 +264,46 @@ OMPI_DECLSPEC ompi_datatype_t ompi_mpi_complex32 = INIT_UNAVAILABLE_DATA( COMPLE
 const ompi_datatype_t* ompi_ddt_basicDatatypes[DT_MAX_PREDEFINED] = {
     &ompi_mpi_loop,
     &ompi_mpi_end_loop,
-    &ompi_mpi_lb,
-    &ompi_mpi_ub,
-    &ompi_mpi_char,
-    &ompi_mpi_character,
-    &ompi_mpi_unsigned_char,
-    &ompi_mpi_signed_char,
-    &ompi_mpi_byte,
-    &ompi_mpi_short,
-    &ompi_mpi_unsigned_short,
-    &ompi_mpi_int,
-    &ompi_mpi_unsigned,
-    &ompi_mpi_long,
-    &ompi_mpi_unsigned_long,
-    &ompi_mpi_long_long_int,
-    &ompi_mpi_unsigned_long_long,
-    &ompi_mpi_float,
-    &ompi_mpi_double,
-    &ompi_mpi_long_double,
-    &ompi_mpi_packed,
-    &ompi_mpi_wchar,
-    &ompi_mpi_cxx_bool,
-    &ompi_mpi_logic,
-    &ompi_mpi_integer,
-    &ompi_mpi_real,
-    &ompi_mpi_dblprec,
-    &ompi_mpi_cplex,
-    &ompi_mpi_dblcplex,
-    &ompi_mpi_ldblcplex,
-    &ompi_mpi_2int,
-    &ompi_mpi_2integer,
-    &ompi_mpi_2real,
-    &ompi_mpi_2dblprec,
-    &ompi_mpi_2cplex,
-    &ompi_mpi_2dblcplex,
-    &ompi_mpi_float_int,
-    &ompi_mpi_double_int,
-    &ompi_mpi_longdbl_int,
-    &ompi_mpi_long_int,
-    &ompi_mpi_short_int,
-    &ompi_mpi_unavailable
+    &ompi_mpi_lb.dt,
+    &ompi_mpi_ub.dt,
+    &ompi_mpi_char.dt,
+    &ompi_mpi_character.dt,
+    &ompi_mpi_unsigned_char.dt,
+    &ompi_mpi_signed_char.dt,
+    &ompi_mpi_byte.dt,
+    &ompi_mpi_short.dt,
+    &ompi_mpi_unsigned_short.dt,
+    &ompi_mpi_int.dt,
+    &ompi_mpi_unsigned.dt,
+    &ompi_mpi_long.dt,
+    &ompi_mpi_unsigned_long.dt,
+    &ompi_mpi_long_long_int.dt,
+    &ompi_mpi_unsigned_long_long.dt,
+    &ompi_mpi_float.dt,
+    &ompi_mpi_double.dt,
+    &ompi_mpi_long_double.dt,
+    &ompi_mpi_packed.dt,
+    &ompi_mpi_wchar.dt,
+    &ompi_mpi_cxx_bool.dt,
+    &ompi_mpi_logic.dt,
+    &ompi_mpi_integer.dt,
+    &ompi_mpi_real.dt,
+    &ompi_mpi_dblprec.dt,
+    &ompi_mpi_cplex.dt,
+    &ompi_mpi_dblcplex.dt,
+    &ompi_mpi_ldblcplex.dt,
+    &ompi_mpi_2int.dt,
+    &ompi_mpi_2integer.dt,
+    &ompi_mpi_2real.dt,
+    &ompi_mpi_2dblprec.dt,
+    &ompi_mpi_2cplex.dt,
+    &ompi_mpi_2dblcplex.dt,
+    &ompi_mpi_float_int.dt,
+    &ompi_mpi_double_int.dt,
+    &ompi_mpi_longdbl_int.dt,
+    &ompi_mpi_long_int.dt,
+    &ompi_mpi_short_int.dt,
+    &ompi_mpi_unavailable.dt
 };
 
 opal_pointer_array_t ompi_datatype_f_to_c_table;
@@ -314,14 +312,14 @@ size_t ompi_ddt_local_sizes[DT_MAX_PREDEFINED];
 
 #define COPY_DATA_DESC( PDST, PSRC )                                    \
     do {                                                                \
+        (PDST)->flags    = (PSRC)->flags;                               \
+        (PDST)->id       = (PSRC)->id;                                  \
         (PDST)->size     = (PSRC)->size;                                \
         (PDST)->true_lb  = (PSRC)->true_lb;                             \
         (PDST)->true_ub  = (PSRC)->true_ub;                             \
-        (PDST)->align    = (PSRC)->align;                               \
         (PDST)->lb       = (PSRC)->lb;                                  \
         (PDST)->ub       = (PSRC)->ub;                                  \
-        (PDST)->flags    = (PSRC)->flags;                               \
-        (PDST)->id       = (PSRC)->id;                                  \
+        (PDST)->align    = (PSRC)->align;                               \
         (PDST)->nbElems  = (PSRC)->nbElems;                             \
         (PDST)->bdt_used = (PSRC)->bdt_used;                            \
         if( NULL != (PDST)->desc.desc )                                 \
@@ -467,41 +465,41 @@ int32_t ompi_ddt_init( void )
      */
 
     /* the 2 complex datatypes (float and double) */
-    DECLARE_MPI2_COMPOSED_STRUCT_DDT( &ompi_mpi_cplex, DT_COMPLEX_FLOAT, "MPI_COMPLEX",
+    DECLARE_MPI2_COMPOSED_STRUCT_DDT( &ompi_mpi_cplex.dt, DT_COMPLEX_FLOAT, "MPI_COMPLEX",
 				      float, float, DT_FLOAT, DT_FLOAT,
 				      DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_FLOAT );
-    DECLARE_MPI2_COMPOSED_STRUCT_DDT( &ompi_mpi_dblcplex, DT_COMPLEX_DOUBLE, "MPI_DOUBLE_COMPLEX",
+    DECLARE_MPI2_COMPOSED_STRUCT_DDT( &ompi_mpi_dblcplex.dt, DT_COMPLEX_DOUBLE, "MPI_DOUBLE_COMPLEX",
 				      double, double, DT_DOUBLE, DT_DOUBLE,
 				      DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_FLOAT );
 #if HAVE_LONG_DOUBLE
-    DECLARE_MPI2_COMPOSED_STRUCT_DDT( &ompi_mpi_ldblcplex, DT_COMPLEX_LONG_DOUBLE, "MPI_LONG_DOUBLE_COMPLEX",
+    DECLARE_MPI2_COMPOSED_STRUCT_DDT( &ompi_mpi_ldblcplex.dt, DT_COMPLEX_LONG_DOUBLE, "MPI_LONG_DOUBLE_COMPLEX",
 				      long double, long double, DT_LONG_DOUBLE, DT_LONG_DOUBLE,
 				      DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_FLOAT );
 #endif  /* HAVE_LONG_DOUBLE */
 
     /* Now the predefined MPI2 datatypes (they should last forever!) */
-    DECLARE_MPI2_COMPOSED_STRUCT_DDT( &ompi_mpi_float_int, DT_FLOAT_INT, "MPI_FLOAT_INT",
+    DECLARE_MPI2_COMPOSED_STRUCT_DDT( &ompi_mpi_float_int.dt, DT_FLOAT_INT, "MPI_FLOAT_INT",
 				      float, int, DT_FLOAT, DT_INT, DT_FLAG_DATA_C );
-    DECLARE_MPI2_COMPOSED_STRUCT_DDT( &ompi_mpi_double_int, DT_DOUBLE_INT, "MPI_DOUBLE_INT",
+    DECLARE_MPI2_COMPOSED_STRUCT_DDT( &ompi_mpi_double_int.dt, DT_DOUBLE_INT, "MPI_DOUBLE_INT",
 				      double, int, DT_DOUBLE, DT_INT, DT_FLAG_DATA_C );
-    DECLARE_MPI2_COMPOSED_STRUCT_DDT( &ompi_mpi_long_int, DT_LONG_INT, "MPI_LONG_INT",
+    DECLARE_MPI2_COMPOSED_STRUCT_DDT( &ompi_mpi_long_int.dt, DT_LONG_INT, "MPI_LONG_INT",
 				      long, int, DT_LONG, DT_INT, DT_FLAG_DATA_C | DT_FLAG_DATA_INT );
-    DECLARE_MPI2_COMPOSED_STRUCT_DDT( &ompi_mpi_short_int, DT_SHORT_INT, "MPI_SHORT_INT",
+    DECLARE_MPI2_COMPOSED_STRUCT_DDT( &ompi_mpi_short_int.dt, DT_SHORT_INT, "MPI_SHORT_INT",
 				      short, int, DT_SHORT, DT_INT, DT_FLAG_DATA_C | DT_FLAG_DATA_INT );
-    DECLARE_MPI2_COMPOSED_STRUCT_DDT( &ompi_mpi_longdbl_int, DT_LONG_DOUBLE_INT, "MPI_LONG_DOUBLE_INT",
+    DECLARE_MPI2_COMPOSED_STRUCT_DDT( &ompi_mpi_longdbl_int.dt, DT_LONG_DOUBLE_INT, "MPI_LONG_DOUBLE_INT",
 				      long double, int, DT_LONG_DOUBLE, DT_INT, DT_FLAG_DATA_C );
 
-    DECLARE_MPI2_COMPOSED_BLOCK_DDT( &ompi_mpi_2int, DT_2INT, "MPI_2INT", DT_INT,
+    DECLARE_MPI2_COMPOSED_BLOCK_DDT( &ompi_mpi_2int.dt, DT_2INT, "MPI_2INT", DT_INT,
 				     DT_FLAG_DATA_C | DT_FLAG_DATA_INT );
-    DECLARE_MPI2_COMPOSED_BLOCK_DDT( &ompi_mpi_2integer, DT_2INTEGER, "MPI_2INTEGER", DT_INT,
+    DECLARE_MPI2_COMPOSED_BLOCK_DDT( &ompi_mpi_2integer.dt, DT_2INTEGER, "MPI_2INTEGER", DT_INT,
 				     DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_INT);
-    DECLARE_MPI2_COMPOSED_BLOCK_DDT( &ompi_mpi_2real, DT_2REAL, "MPI_2REAL", DT_FLOAT,
+    DECLARE_MPI2_COMPOSED_BLOCK_DDT( &ompi_mpi_2real.dt, DT_2REAL, "MPI_2REAL", DT_FLOAT,
 				     DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_FLOAT );
-    DECLARE_MPI2_COMPOSED_BLOCK_DDT( &ompi_mpi_2dblprec, DT_2DBLPREC, "MPI_2DOUBLE_PRECISION", DT_DOUBLE,
+    DECLARE_MPI2_COMPOSED_BLOCK_DDT( &ompi_mpi_2dblprec.dt, DT_2DBLPREC, "MPI_2DOUBLE_PRECISION", DT_DOUBLE,
 				     DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_FLOAT );
-    DECLARE_MPI2_COMPOSED_BLOCK_DDT( &ompi_mpi_2cplex, DT_2COMPLEX, "MPI_2COMPLEX", DT_COMPLEX_FLOAT,
+    DECLARE_MPI2_COMPOSED_BLOCK_DDT( &ompi_mpi_2cplex.dt, DT_2COMPLEX, "MPI_2COMPLEX", DT_COMPLEX_FLOAT,
 				     DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_FLOAT);
-    DECLARE_MPI2_COMPOSED_BLOCK_DDT( &ompi_mpi_2dblcplex, DT_2DOUBLE_COMPLEX, "MPI_2DOUBLE_COMPLEX",
+    DECLARE_MPI2_COMPOSED_BLOCK_DDT( &ompi_mpi_2dblcplex.dt, DT_2DOUBLE_COMPLEX, "MPI_2DOUBLE_COMPLEX",
                                      DT_COMPLEX_DOUBLE, DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_FLOAT );
 
     for( i = 0; i < DT_MAX_PREDEFINED; ++i ) {
@@ -512,206 +510,206 @@ int32_t ompi_ddt_init( void )
        the synonym types */
 
     /* C++ complex types */
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_cxx_cplex, "MPI_CXX_COMPLEX", &ompi_mpi_cplex );
-    ompi_mpi_cxx_cplex.flags |= DT_FLAG_DATA_CPP | DT_FLAG_DATA_COMPLEX;
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_cxx_dblcplex, "MPI_CXX_DOUBLE_COMPLEX", &ompi_mpi_dblcplex );
-    ompi_mpi_cxx_dblcplex.flags |= DT_FLAG_DATA_CPP | DT_FLAG_DATA_COMPLEX;
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_cxx_cplex.dt, "MPI_CXX_COMPLEX", &ompi_mpi_cplex.dt );
+    ompi_mpi_cxx_cplex.dt.flags |= DT_FLAG_DATA_CPP | DT_FLAG_DATA_COMPLEX;
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_cxx_dblcplex.dt, "MPI_CXX_DOUBLE_COMPLEX", &ompi_mpi_dblcplex.dt );
+    ompi_mpi_cxx_dblcplex.dt.flags |= DT_FLAG_DATA_CPP | DT_FLAG_DATA_COMPLEX;
 #if HAVE_LONG_DOUBLE
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_cxx_ldblcplex, "MPI_CXX_LONG_DOUBLE_COMPLEX", &ompi_mpi_ldblcplex );
-    ompi_mpi_cxx_ldblcplex.flags |= DT_FLAG_DATA_CPP | DT_FLAG_DATA_COMPLEX;
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_cxx_ldblcplex.dt, "MPI_CXX_LONG_DOUBLE_COMPLEX", &ompi_mpi_ldblcplex.dt );
+    ompi_mpi_cxx_ldblcplex.dt.flags |= DT_FLAG_DATA_CPP | DT_FLAG_DATA_COMPLEX;
 #endif  /* HAVE_LONG_DOUBLE */
 
     /* Optional Fortran LOGICAL types */
 #if OMPI_HAVE_FORTRAN_LOGICAL1
 #if (OMPI_SIZEOF_FORTRAN_LOGICAL1 == SIZEOF_CHAR)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_logical1, "MPI_LOGICAL1", &ompi_mpi_char );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_logical1.dt, "MPI_LOGICAL1", &ompi_mpi_char.dt );
 #elif (OMPI_SIZEOF_FORTRAN_LOGICAL1 == SIZEOF_SHORT)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_logical1, "MPI_LOGICAL1", &ompi_mpi_short );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_logical1.dt, "MPI_LOGICAL1", &ompi_mpi_short.dt );
 #elif (OMPI_SIZEOF_FORTRAN_LOGICAL1 == SIZEOF_INT)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_logical1, "MPI_LOGICAL1", &ompi_mpi_int );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_logical1.dt, "MPI_LOGICAL1", &ompi_mpi_int.dt );
 #else
 #   warning "No proper C type found for LOGICAL1"
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_logical1, "MPI_LOGICAL1", &ompi_mpi_unavailable );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_logical1.dt, "MPI_LOGICAL1", &ompi_mpi_unavailable.dt );
 #endif
-    ompi_mpi_logical1.flags |= DT_FLAG_DATA_FORTRAN;
+    ompi_mpi_logical1.dt.flags |= DT_FLAG_DATA_FORTRAN;
 #endif /* OMPI_HAVE_FORTRAN_LOGICAL1 */
 
 #if OMPI_HAVE_FORTRAN_LOGICAL2
 #if (OMPI_SIZEOF_FORTRAN_LOGICAL2 == SIZEOF_SHORT)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_logical2, "MPI_LOGICAL2", &ompi_mpi_short );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_logical2.dt, "MPI_LOGICAL2", &ompi_mpi_short.dt );
 #elif (OMPI_SIZEOF_FORTRAN_LOGICAL2 == SIZEOF_INT)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_logical2, "MPI_LOGICAL2", &ompi_mpi_int );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_logical2.dt, "MPI_LOGICAL2", &ompi_mpi_int.dt );
 #else
 #   warning "No proper C type found for LOGICAL2"
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_logical2, "MPI_LOGICAL2", &ompi_mpi_unavailable );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_logical2.dt, "MPI_LOGICAL2", &ompi_mpi_unavailable.dt );
 #endif
-    ompi_mpi_logical2.flags |= DT_FLAG_DATA_FORTRAN;
+    ompi_mpi_logical2.dt.flags |= DT_FLAG_DATA_FORTRAN;
 #endif /* OMPI_HAVE_FORTRAN_LOGICAL2 */
 
 #if OMPI_HAVE_FORTRAN_LOGICAL4
 #if (OMPI_SIZEOF_FORTRAN_LOGICAL4 == SIZEOF_INT)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_logical4, "MPI_LOGICAL4", &ompi_mpi_int );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_logical4.dt, "MPI_LOGICAL4", &ompi_mpi_int.dt );
 #elif (OMPI_SIZEOF_FORTRAN_LOGICAL4 == SIZEOF_LONG)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_logical4, "MPI_LOGICAL4", &ompi_mpi_long );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_logical4.dt, "MPI_LOGICAL4", &ompi_mpi_long.dt );
 #else
 #   warning "No proper C type found for LOGICAL4"
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_logical4, "MPI_LOGICAL4", &ompi_mpi_unavailable );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_logical4.dt, "MPI_LOGICAL4", &ompi_mpi_unavailable.dt );
 #endif
-    ompi_mpi_logical4.flags |= DT_FLAG_DATA_FORTRAN;
+    ompi_mpi_logical4.dt.flags |= DT_FLAG_DATA_FORTRAN;
 #endif /* OMPI_HAVE_FORTRAN_LOGICAL4 */
 
 #if OMPI_HAVE_FORTRAN_LOGICAL8
 #if (OMPI_SIZEOF_FORTRAN_LOGICAL8 == SIZEOF_LONG)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_logical8, "MPI_LOGICAL8", &ompi_mpi_long );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_logical8.dt, "MPI_LOGICAL8", &ompi_mpi_long.dt );
 #elif (OMPI_SIZEOF_FORTRAN_LOGICAL8 == SIZEOF_LONG_LONG)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_logical8, "MPI_LOGICAL8", &ompi_mpi_long_long_int );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_logical8.dt, "MPI_LOGICAL8", &ompi_mpi_long_long_int.dt );
 #else
 #   warning "No proper C type found for LOGICAL8"
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_logical8, "MPI_LOGICAL8", &ompi_mpi_unavailable );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_logical8.dt, "MPI_LOGICAL8", &ompi_mpi_unavailable.dt );
 #endif
-    ompi_mpi_logical8.flags |= DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_INT;
+    ompi_mpi_logical8.dt.flags |= DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_INT;
 #endif /* OMPI_HAVE_FORTRAN_INTEGER8 */
 
     /* Optional Fortran REAL types */
 
 #if OMPI_HAVE_FORTRAN_REAL2
 #if (OMPI_SIZEOF_FORTRAN_REAL2 == SIZEOF_FLOAT)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_real2, "MPI_REAL2", &ompi_mpi_float );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_real2.dt, "MPI_REAL2", &ompi_mpi_float.dt );
 #else
 #   warning "No proper C type found for REAL2"
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_real2, "MPI_REAL2", &ompi_mpi_unavailable );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_real2.dt, "MPI_REAL2", &ompi_mpi_unavailable.dt );
 #endif
-    ompi_mpi_real2.flags |= DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_FLOAT;
+    ompi_mpi_real2.dt.flags |= DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_FLOAT;
 #endif /* OMPI_HAVE_FORTRAN_REAL2 */
 
 #if OMPI_HAVE_FORTRAN_REAL4
 #if (OMPI_SIZEOF_FORTRAN_REAL4 == SIZEOF_FLOAT)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_real4, "MPI_REAL4", &ompi_mpi_float );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_real4.dt, "MPI_REAL4", &ompi_mpi_float.dt );
 #else
 #   warning "No proper C type found for REAL4"
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_real4, "MPI_REAL4", &ompi_mpi_unavailable );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_real4.dt, "MPI_REAL4", &ompi_mpi_unavailable.dt );
 #endif
-    ompi_mpi_real4.flags |= DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_FLOAT;
+    ompi_mpi_real4.dt.flags |= DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_FLOAT;
 #endif /* OMPI_HAVE_FORTRAN_REAL4 */
 
 #if OMPI_HAVE_FORTRAN_REAL8
 #if (OMPI_SIZEOF_FORTRAN_REAL8 == SIZEOF_FLOAT)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_real8, "MPI_REAL8", &ompi_mpi_float );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_real8.dt, "MPI_REAL8", &ompi_mpi_float.dt );
 #elif (OMPI_SIZEOF_FORTRAN_REAL8 == SIZEOF_DOUBLE)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_real8, "MPI_REAL8", &ompi_mpi_double );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_real8.dt, "MPI_REAL8", &ompi_mpi_double.dt );
 #elif (OMPI_SIZEOF_FORTRAN_REAL8 == SIZEOF_LONG_DOUBLE)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_real8, "MPI_REAL8", &ompi_mpi_long_double );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_real8.dt, "MPI_REAL8", &ompi_mpi_long_double.dt );
 #else
 #   warning "No proper C type found for REAL8"
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_real8, "MPI_REAL8", &ompi_mpi_unavailable );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_real8.dt, "MPI_REAL8", &ompi_mpi_unavailable.dt );
 #endif
-    ompi_mpi_real8.flags |= DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_FLOAT;
+    ompi_mpi_real8.dt.flags |= DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_FLOAT;
 #endif /* OMPI_HAVE_FORTRAN_REAL8 */
 
 #if OMPI_HAVE_FORTRAN_REAL16
 #if (OMPI_SIZEOF_FORTRAN_REAL16 == SIZEOF_LONG_DOUBLE)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_real16, "MPI_REAL16", &ompi_mpi_long_double );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_real16.dt, "MPI_REAL16", &ompi_mpi_long_double.dt );
 #else
 #   warning "No proper C type found for REAL16"
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_real16, "MPI_REAL16", &ompi_mpi_unavailable );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_real16.dt, "MPI_REAL16", &ompi_mpi_unavailable.dt );
 #endif
-    ompi_mpi_real16.flags |= DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_FLOAT;
+    ompi_mpi_real16.dt.flags |= DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_FLOAT;
 #endif /* OMPI_HAVE_FORTRAN_REAL16 */
 
     /* Optional Fortran INTEGER types */
 
 #if OMPI_HAVE_FORTRAN_INTEGER1
 #if (OMPI_SIZEOF_FORTRAN_INTEGER1 == SIZEOF_CHAR)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer1, "MPI_INTEGER1", &ompi_mpi_char );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer1.dt, "MPI_INTEGER1", &ompi_mpi_char.dt );
 #elif (OMPI_SIZEOF_FORTRAN_INTEGER1 == SIZEOF_SHORT)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer1, "MPI_INTEGER1", &ompi_mpi_short );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer1.dt, "MPI_INTEGER1", &ompi_mpi_short.dt );
 #elif (OMPI_SIZEOF_FORTRAN_INTEGER1 == SIZEOF_INT)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer1, "MPI_INTEGER1", &ompi_mpi_int );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer1.dt, "MPI_INTEGER1", &ompi_mpi_int.dt );
 #else
 #   warning "No proper C type found for INTEGER1"
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer1, "MPI_INTEGER1", &ompi_mpi_unavailable );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer1.dt, "MPI_INTEGER1", &ompi_mpi_unavailable.dt );
 #endif
-    ompi_mpi_integer1.flags |= DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_INT;
+    ompi_mpi_integer1.dt.flags |= DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_INT;
 #endif /* OMPI_HAVE_FORTRAN_INTEGER1 */
 
 #if OMPI_HAVE_FORTRAN_INTEGER2
 #if (OMPI_SIZEOF_FORTRAN_INTEGER2 == SIZEOF_SHORT)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer2, "MPI_INTEGER2", &ompi_mpi_short );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer2.dt, "MPI_INTEGER2", &ompi_mpi_short.dt );
 #elif (OMPI_SIZEOF_FORTRAN_INTEGER2 == SIZEOF_INT)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer2, "MPI_INTEGER2", &ompi_mpi_int );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer2.dt, "MPI_INTEGER2", &ompi_mpi_int.dt );
 #else
 #   warning "No proper C type found for INTEGER2"
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer2, "MPI_INTEGER2", &ompi_mpi_unavailable );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer2.dt, "MPI_INTEGER2", &ompi_mpi_unavailable.dt );
 #endif
-    ompi_mpi_integer2.flags |= DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_INT;
+    ompi_mpi_integer2.dt.flags |= DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_INT;
 #endif /* OMPI_HAVE_FORTRAN_INTEGER2 */
 
 #if OMPI_HAVE_FORTRAN_INTEGER4
 #if (OMPI_SIZEOF_FORTRAN_INTEGER4 == SIZEOF_INT)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer4, "MPI_INTEGER4", &ompi_mpi_int );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer4.dt, "MPI_INTEGER4", &ompi_mpi_int.dt );
 #elif (OMPI_SIZEOF_FORTRAN_INTEGER4 == SIZEOF_LONG)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer4, "MPI_INTEGER4", &ompi_mpi_long );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer4.dt, "MPI_INTEGER4", &ompi_mpi_long.dt );
 #else
 #   warning "No proper C type found for INTEGER4"
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer4, "MPI_INTEGER4", &ompi_mpi_unavailable );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer4.dt, "MPI_INTEGER4", &ompi_mpi_unavailable.dt );
 #endif
-    ompi_mpi_integer4.flags |= DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_INT;
+    ompi_mpi_integer4.dt.flags |= DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_INT;
 #endif /* OMPI_HAVE_FORTRAN_INTEGER4 */
 
 #if OMPI_HAVE_FORTRAN_INTEGER8
 #if (OMPI_SIZEOF_FORTRAN_INTEGER8 == SIZEOF_LONG)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer8, "MPI_INTEGER8", &ompi_mpi_long );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer8.dt, "MPI_INTEGER8", &ompi_mpi_long.dt );
 #elif (OMPI_SIZEOF_FORTRAN_INTEGER8 == SIZEOF_LONG_LONG)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer8, "MPI_INTEGER8", &ompi_mpi_long_long_int );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer8.dt, "MPI_INTEGER8", &ompi_mpi_long_long_int.dt );
 #else
 #   warning "No proper C type found for INTEGER8"
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer8, "MPI_INTEGER8", &ompi_mpi_unavailable );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer8.dt, "MPI_INTEGER8", &ompi_mpi_unavailable.dt );
 #endif
-    ompi_mpi_integer8.flags |= DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_INT;
+    ompi_mpi_integer8.dt.flags |= DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_INT;
 #endif /* OMPI_HAVE_FORTRAN_INTEGER8 */
 
 #if OMPI_HAVE_FORTRAN_INTEGER16
 #if (OMPI_SIZEOF_FORTRAN_INTEGER16 == SIZEOF_LONG_LONG)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer16, "MPI_INTEGER16", &ompi_mpi_long_long_int );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer16.dt, "MPI_INTEGER16", &ompi_mpi_long_long_int.dt );
 #else
 #   warning "No proper C type found for INTEGER16"
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer16, "MPI_INTEGER16", &ompi_mpi_unavailable );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_integer16.dt, "MPI_INTEGER16", &ompi_mpi_unavailable.dt );
 #endif
-    ompi_mpi_integer16.flags |= DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_INT;
+    ompi_mpi_integer16.dt.flags |= DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_INT;
 #endif /* OMPI_HAVE_FORTRAN_INTEGER16 */
 
     /* Optional Fortran COMPLEX types */
 
 #if OMPI_HAVE_FORTRAN_COMPLEX8
 #if (OMPI_SIZEOF_FORTRAN_COMPLEX8 == 2*SIZEOF_FLOAT)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_complex8, "MPI_COMPLEX8", &ompi_mpi_cplex );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_complex8.dt, "MPI_COMPLEX8", &ompi_mpi_cplex.dt );
 #else
 #   warning "No proper C type found for COMPLEX8"
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_complex8, "MPI_COMPLEX8", &ompi_mpi_unavailable );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_complex8.dt, "MPI_COMPLEX8", &ompi_mpi_unavailable.dt );
 #endif
-    ompi_mpi_complex8.flags |= DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_COMPLEX;
+    ompi_mpi_complex8.dt.flags |= DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_COMPLEX;
 #endif /* OMPI_HAVE_FORTRAN_COMPLEX8 */
 
 #if OMPI_HAVE_FORTRAN_COMPLEX16
 #if (OMPI_SIZEOF_FORTRAN_COMPLEX16 == 2*SIZEOF_FLOAT)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_complex16, "MPI_COMPLEX16", &ompi_mpi_cplex );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_complex16.dt, "MPI_COMPLEX16", &ompi_mpi_cplex.dt );
 #elif (OMPI_SIZEOF_FORTRAN_COMPLEX16 == 2*SIZEOF_DOUBLE)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_complex16, "MPI_COMPLEX16", &ompi_mpi_dblcplex );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_complex16.dt, "MPI_COMPLEX16", &ompi_mpi_dblcplex.dt );
 #else
 #   warning "No proper C type found for COMPLEX16"
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_complex16, "MPI_COMPLEX16", &ompi_mpi_unavailable );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_complex16.dt, "MPI_COMPLEX16", &ompi_mpi_unavailable.dt );
 #endif
-    ompi_mpi_complex16.flags |= DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_COMPLEX;
+    ompi_mpi_complex16.dt.flags |= DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_COMPLEX;
 #endif /* OMPI_HAVE_FORTRAN_COMPLEX16 */
 
 #if OMPI_HAVE_FORTRAN_COMPLEX32
 #if OMPI_REAL16_MATCHES_C && (OMPI_SIZEOF_FORTRAN_COMPLEX32 == 2*SIZEOF_LONG_DOUBLE)
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_complex32, "MPI_COMPLEX32", &ompi_mpi_ldblcplex );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_complex32.dt, "MPI_COMPLEX32", &ompi_mpi_ldblcplex.dt );
 #else
 #   warning "No proper C type found for COMPLEX32"
-    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_complex32, "MPI_COMPLEX32", &ompi_mpi_unavailable );
+    DECLARE_MPI_SYNONYM_DDT( &ompi_mpi_complex32.dt, "MPI_COMPLEX32", &ompi_mpi_unavailable.dt );
 #endif
-    ompi_mpi_complex32.flags |= DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_COMPLEX;
+    ompi_mpi_complex32.dt.flags |= DT_FLAG_DATA_FORTRAN | DT_FLAG_DATA_COMPLEX;
 #endif /* OMPI_HAVE_FORTRAN_COMPLEX32 */
 
     /* Start to populate the f2c index translation table */
@@ -726,10 +724,10 @@ int32_t ompi_ddt_init( void )
 
 #define MOOG(name)                                                      \
     {                                                                   \
-        ompi_mpi_##name.d_f_to_c_index =                                \
+        ompi_mpi_##name.dt.d_f_to_c_index =                                \
             opal_pointer_array_add(&ompi_datatype_f_to_c_table, &ompi_mpi_##name); \
-        if( ompi_ddt_number_of_predefined_data < (ompi_mpi_##name).d_f_to_c_index ) \
-            ompi_ddt_number_of_predefined_data = (ompi_mpi_##name).d_f_to_c_index; \
+        if( ompi_ddt_number_of_predefined_data < (ompi_mpi_##name).dt.d_f_to_c_index ) \
+            ompi_ddt_number_of_predefined_data = (ompi_mpi_##name).dt.d_f_to_c_index; \
     }
 
     /*
@@ -803,7 +801,7 @@ int32_t ompi_ddt_init( void )
     MOOG(cxx_dblcplex);
     MOOG(cxx_ldblcplex);
 
-    for( i = 0; i < ompi_mpi_cxx_ldblcplex.d_f_to_c_index; i++ ) {
+    for( i = 0; i < ompi_mpi_cxx_ldblcplex.dt.d_f_to_c_index; i++ ) {
         ompi_datatype_t* datatype = (ompi_datatype_t*)opal_pointer_array_get_item(&ompi_datatype_f_to_c_table, i );
 
         if( (datatype->ub - datatype->lb) == (ptrdiff_t)datatype->size ) {
diff --git a/ompi/errhandler/errhandler.c b/ompi/errhandler/errhandler.c
index 327ecac7ba..7dbb61256f 100644
--- a/ompi/errhandler/errhandler.c
+++ b/ompi/errhandler/errhandler.c
@@ -11,6 +11,7 @@
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
  * Copyright (c) 2008      Cisco Systems, Inc.  All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc.  All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -48,10 +49,10 @@ OBJ_CLASS_INSTANCE(ompi_errhandler_t, opal_object_t, ompi_errhandler_construct,
                    ompi_errhandler_destruct);
 
 
-ompi_errhandler_t ompi_mpi_errhandler_null;
-ompi_errhandler_t ompi_mpi_errors_are_fatal;
-ompi_errhandler_t ompi_mpi_errors_return;
-ompi_errhandler_t ompi_mpi_errors_throw_exceptions;
+ompi_predefined_errhandler_t ompi_mpi_errhandler_null;
+ompi_predefined_errhandler_t ompi_mpi_errors_are_fatal;
+ompi_predefined_errhandler_t ompi_mpi_errors_return;
+ompi_predefined_errhandler_t ompi_mpi_errors_throw_exceptions;
 
 /*
  * Local state to know when the three intrinsics have been freed; see
@@ -77,41 +78,41 @@ int ompi_errhandler_init(void)
   }
 
   /* Initialize the predefined error handlers */
-  OBJ_CONSTRUCT( &ompi_mpi_errhandler_null, ompi_errhandler_t );
-  if( ompi_mpi_errhandler_null.eh_f_to_c_index != OMPI_ERRHANDLER_NULL_FORTRAN )
+  OBJ_CONSTRUCT( &ompi_mpi_errhandler_null.eh, ompi_errhandler_t );
+  if( ompi_mpi_errhandler_null.eh.eh_f_to_c_index != OMPI_ERRHANDLER_NULL_FORTRAN )
       return OMPI_ERROR;
-  ompi_mpi_errhandler_null.eh_mpi_object_type = OMPI_ERRHANDLER_TYPE_PREDEFINED;
-  ompi_mpi_errhandler_null.eh_lang = OMPI_ERRHANDLER_LANG_C;
-  ompi_mpi_errhandler_null.eh_comm_fn = NULL;
-  ompi_mpi_errhandler_null.eh_file_fn = NULL;
-  ompi_mpi_errhandler_null.eh_win_fn  = NULL ;
-  ompi_mpi_errhandler_null.eh_fort_fn = NULL;
-  strncpy (ompi_mpi_errhandler_null.eh_name, "MPI_ERRHANDLER_NULL", 
+  ompi_mpi_errhandler_null.eh.eh_mpi_object_type = OMPI_ERRHANDLER_TYPE_PREDEFINED;
+  ompi_mpi_errhandler_null.eh.eh_lang = OMPI_ERRHANDLER_LANG_C;
+  ompi_mpi_errhandler_null.eh.eh_comm_fn = NULL;
+  ompi_mpi_errhandler_null.eh.eh_file_fn = NULL;
+  ompi_mpi_errhandler_null.eh.eh_win_fn  = NULL ;
+  ompi_mpi_errhandler_null.eh.eh_fort_fn = NULL;
+  strncpy (ompi_mpi_errhandler_null.eh.eh_name, "MPI_ERRHANDLER_NULL", 
 	   strlen("MPI_ERRHANDLER_NULL")+1 );
 
 
-  OBJ_CONSTRUCT( &ompi_mpi_errors_are_fatal, ompi_errhandler_t );
-  if( ompi_mpi_errors_are_fatal.eh_f_to_c_index != OMPI_ERRORS_ARE_FATAL_FORTRAN )
+  OBJ_CONSTRUCT( &ompi_mpi_errors_are_fatal.eh, ompi_errhandler_t );
+  if( ompi_mpi_errors_are_fatal.eh.eh_f_to_c_index != OMPI_ERRORS_ARE_FATAL_FORTRAN )
       return OMPI_ERROR;
-  ompi_mpi_errors_are_fatal.eh_mpi_object_type = OMPI_ERRHANDLER_TYPE_PREDEFINED;
-  ompi_mpi_errors_are_fatal.eh_lang = OMPI_ERRHANDLER_LANG_C;
-  ompi_mpi_errors_are_fatal.eh_comm_fn = ompi_mpi_errors_are_fatal_comm_handler;
-  ompi_mpi_errors_are_fatal.eh_file_fn = ompi_mpi_errors_are_fatal_file_handler;
-  ompi_mpi_errors_are_fatal.eh_win_fn  = ompi_mpi_errors_are_fatal_win_handler ;
-  ompi_mpi_errors_are_fatal.eh_fort_fn = NULL;
-  strncpy (ompi_mpi_errors_are_fatal.eh_name, "MPI_ERRORS_ARE_FATAL", 
+  ompi_mpi_errors_are_fatal.eh.eh_mpi_object_type = OMPI_ERRHANDLER_TYPE_PREDEFINED;
+  ompi_mpi_errors_are_fatal.eh.eh_lang = OMPI_ERRHANDLER_LANG_C;
+  ompi_mpi_errors_are_fatal.eh.eh_comm_fn = ompi_mpi_errors_are_fatal_comm_handler;
+  ompi_mpi_errors_are_fatal.eh.eh_file_fn = ompi_mpi_errors_are_fatal_file_handler;
+  ompi_mpi_errors_are_fatal.eh.eh_win_fn  = ompi_mpi_errors_are_fatal_win_handler ;
+  ompi_mpi_errors_are_fatal.eh.eh_fort_fn = NULL;
+  strncpy (ompi_mpi_errors_are_fatal.eh.eh_name, "MPI_ERRORS_ARE_FATAL", 
 	   strlen("MPI_ERRORS_ARE_FATAL")+1 );
   
-  OBJ_CONSTRUCT( &ompi_mpi_errors_return, ompi_errhandler_t );
-  if( ompi_mpi_errors_return.eh_f_to_c_index != OMPI_ERRORS_RETURN_FORTRAN )
+  OBJ_CONSTRUCT( &ompi_mpi_errors_return.eh, ompi_errhandler_t );
+  if( ompi_mpi_errors_return.eh.eh_f_to_c_index != OMPI_ERRORS_RETURN_FORTRAN )
       return OMPI_ERROR;
-  ompi_mpi_errors_return.eh_mpi_object_type  = OMPI_ERRHANDLER_TYPE_PREDEFINED;
-  ompi_mpi_errors_return.eh_lang = OMPI_ERRHANDLER_LANG_C;
-  ompi_mpi_errors_return.eh_comm_fn = ompi_mpi_errors_return_comm_handler;
-  ompi_mpi_errors_return.eh_file_fn = ompi_mpi_errors_return_file_handler;
-  ompi_mpi_errors_return.eh_win_fn  = ompi_mpi_errors_return_win_handler;
-  ompi_mpi_errors_return.eh_fort_fn = NULL;
-  strncpy (ompi_mpi_errors_return.eh_name, "MPI_ERRORS_RETURN", 
+  ompi_mpi_errors_return.eh.eh_mpi_object_type  = OMPI_ERRHANDLER_TYPE_PREDEFINED;
+  ompi_mpi_errors_return.eh.eh_lang = OMPI_ERRHANDLER_LANG_C;
+  ompi_mpi_errors_return.eh.eh_comm_fn = ompi_mpi_errors_return_comm_handler;
+  ompi_mpi_errors_return.eh.eh_file_fn = ompi_mpi_errors_return_file_handler;
+  ompi_mpi_errors_return.eh.eh_win_fn  = ompi_mpi_errors_return_win_handler;
+  ompi_mpi_errors_return.eh.eh_fort_fn = NULL;
+  strncpy (ompi_mpi_errors_return.eh.eh_name, "MPI_ERRORS_RETURN", 
 	   strlen("MPI_ERRORS_RETURN")+1 );
 
   /* If we're going to use C++, functions will be fixed up during
@@ -119,19 +120,18 @@ int ompi_errhandler_init(void)
      the dispatch function is in C (although in libmpi_cxx); the
      conversion from C handles to C++ handles happens in that dispatch
      function -- not the errhandler_invoke.c stuff here in libmpi. */
-  OBJ_CONSTRUCT( &ompi_mpi_errors_throw_exceptions, ompi_errhandler_t );
-  ompi_mpi_errors_throw_exceptions.eh_mpi_object_type = 
+  OBJ_CONSTRUCT( &ompi_mpi_errors_throw_exceptions.eh, ompi_errhandler_t );
+  ompi_mpi_errors_throw_exceptions.eh.eh_mpi_object_type = 
       OMPI_ERRHANDLER_TYPE_PREDEFINED;
-  ompi_mpi_errors_throw_exceptions.eh_lang = OMPI_ERRHANDLER_LANG_C;
-  ompi_mpi_errors_throw_exceptions.eh_comm_fn = 
+  ompi_mpi_errors_throw_exceptions.eh.eh_lang = OMPI_ERRHANDLER_LANG_C;
+  ompi_mpi_errors_throw_exceptions.eh.eh_comm_fn = 
       ompi_mpi_errors_are_fatal_comm_handler;
-  ompi_mpi_errors_throw_exceptions.eh_file_fn = 
+  ompi_mpi_errors_throw_exceptions.eh.eh_file_fn = 
       ompi_mpi_errors_are_fatal_file_handler;
-  ompi_mpi_errors_throw_exceptions.eh_win_fn  = 
+  ompi_mpi_errors_throw_exceptions.eh.eh_win_fn  = 
       ompi_mpi_errors_are_fatal_win_handler ;
-  ompi_mpi_errors_throw_exceptions.eh_fort_fn = NULL;
-  strncpy (ompi_mpi_errors_throw_exceptions.eh_name,
-           "MPI_ERRORS_THROW_EXCEPTIONS", 
+  ompi_mpi_errors_throw_exceptions.eh.eh_fort_fn = NULL;
+  strncpy (ompi_mpi_errors_throw_exceptions.eh.eh_name, "MPI_ERRORS_THROW_EXCEPTIONS", 
 	   strlen("MPI_ERRORS_THROW_EXCEPTIONS")+1 );
 
   /* All done */
@@ -154,16 +154,16 @@ int ompi_errhandler_finalize(void)
        freed. */
 
     while (!null_freed) {
-        OBJ_DESTRUCT(&ompi_mpi_errhandler_null);
+        OBJ_DESTRUCT(&ompi_mpi_errhandler_null.eh);
     }
     while (!fatal_freed) {
-        OBJ_DESTRUCT(&ompi_mpi_errors_are_fatal);
+        OBJ_DESTRUCT(&ompi_mpi_errors_are_fatal.eh);
     }
     while (!return_freed) {
-        OBJ_DESTRUCT(&ompi_mpi_errors_return);
+        OBJ_DESTRUCT(&ompi_mpi_errors_return.eh);
     }
     while (!throw_freed) {
-        OBJ_DESTRUCT(&ompi_mpi_errors_throw_exceptions);
+        OBJ_DESTRUCT(&ompi_mpi_errors_throw_exceptions.eh);
     }
   
     /* JMS Add stuff here checking for unreleased errorhandlers,
@@ -281,13 +281,13 @@ static void ompi_errhandler_destruct(ompi_errhandler_t *errhandler)
   /* Reset the static state if we're releasing one of the
      intrinsics */
 
-  if (&ompi_mpi_errhandler_null == errhandler) {
+  if (&ompi_mpi_errhandler_null.eh == errhandler) {
       null_freed = true;
-  } else if (&ompi_mpi_errors_are_fatal == errhandler) {
+  } else if (&ompi_mpi_errors_are_fatal.eh == errhandler) {
       fatal_freed = true;
-  } else if (&ompi_mpi_errors_return == errhandler) {
+  } else if (&ompi_mpi_errors_return.eh == errhandler) {
       return_freed = true;
-  } else if (&ompi_mpi_errors_throw_exceptions == errhandler) {
+  } else if (&ompi_mpi_errors_throw_exceptions.eh == errhandler) {
       throw_freed = true;
   }
 }
diff --git a/ompi/errhandler/errhandler.h b/ompi/errhandler/errhandler.h
index a08fb94692..04f3e0c0f8 100644
--- a/ompi/errhandler/errhandler.h
+++ b/ompi/errhandler/errhandler.h
@@ -11,7 +11,7 @@
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
  * Copyright (c) 2008      Cisco Systems, Inc.  All rights reserved.
- * Copyright (c) 2008      Sun Microsystems, Inc.  All rights reserved.
+ * Copyright (c) 2008-2009 Sun Microsystems, Inc.  All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -127,27 +127,41 @@ struct ompi_errhandler_t {
 };
 typedef struct ompi_errhandler_t ompi_errhandler_t;
 
+/**
+ * Padded struct to maintain back compatibiltiy.
+ * See ompi/communicator/communicator.h comments with struct ompi_communicator_t
+ * for full explanation why we chose the following padding construct for predefines.
+ */
+#define PREDEFINED_ERRHANDLER_PAD 1024
+
+struct ompi_predefined_errhandler_t {
+    struct ompi_errhandler_t eh;
+    char padding[PREDEFINED_ERRHANDLER_PAD - sizeof(ompi_errhandler_t)];
+};
+
+typedef struct ompi_predefined_errhandler_t ompi_predefined_errhandler_t;
+
 
 /**
  * Global variable for MPI_ERRHANDLER_NULL
  */
-OMPI_DECLSPEC extern ompi_errhandler_t ompi_mpi_errhandler_null;
+OMPI_DECLSPEC extern ompi_predefined_errhandler_t ompi_mpi_errhandler_null;
 
 /**
  * Global variable for MPI_ERRORS_ARE_FATAL
  */
-OMPI_DECLSPEC extern ompi_errhandler_t ompi_mpi_errors_are_fatal;
+OMPI_DECLSPEC extern ompi_predefined_errhandler_t ompi_mpi_errors_are_fatal;
 
 /**
  * Global variable for MPI_ERRORS_RETURN
  */
-OMPI_DECLSPEC extern ompi_errhandler_t ompi_mpi_errors_return;
+OMPI_DECLSPEC extern ompi_predefined_errhandler_t ompi_mpi_errors_return;
 
 /**
  * Global variable for MPI::ERRORS_THROW_EXCEPTIONS.  Will abort if
  * MPI_INIT wasn't called as MPI::INIT
  */
-OMPI_DECLSPEC extern ompi_errhandler_t ompi_mpi_errors_throw_exceptions;
+OMPI_DECLSPEC extern ompi_predefined_errhandler_t ompi_mpi_errors_throw_exceptions;
 
 /**
  * Table for Fortran <-> C errhandler handle conversion
diff --git a/ompi/errhandler/errhandler_predefined.c b/ompi/errhandler/errhandler_predefined.c
index fc9cff12cb..a666b27c43 100644
--- a/ompi/errhandler/errhandler_predefined.c
+++ b/ompi/errhandler/errhandler_predefined.c
@@ -11,6 +11,7 @@
  *                         All rights reserved.
  * Copyright (c) 2006      University of Houston. All rights reserved.
  * Copyright (c) 2008      Cisco Systems, Inc.  All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc.  All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -292,7 +293,7 @@ static void backend_fatal(char *type, struct ompi_communicator_t *comm,
     /* Should we do something more intelligent than just using
        COMM_SELF? */
     if (comm == NULL) {
-        comm = &ompi_mpi_comm_self;
+        comm = &ompi_mpi_comm_self.comm;
     }
 
     if (NULL != error_code) {
diff --git a/ompi/file/file.c b/ompi/file/file.c
index fd3c729b45..3195d514ab 100644
--- a/ompi/file/file.c
+++ b/ompi/file/file.c
@@ -10,7 +10,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
- * Copyright (c) 2008      Sun Microsystems, Inc.  All rights reserved.
+ * Copyright (c) 2008-2009 Sun Microsystems, Inc.  All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -20,6 +20,7 @@
 
 #include "ompi_config.h"
 
+#include "ompi/communicator/communicator.h"
 #include "ompi/file/file.h"
 #include "opal/class/opal_list.h"
 #include "opal/util/output.h"
@@ -35,7 +36,7 @@ opal_pointer_array_t ompi_file_f_to_c_table;
 /*
  * MPI_FILE_NULL
  */
-ompi_file_t  ompi_mpi_file_null;
+ompi_predefined_file_t  ompi_mpi_file_null;
 
 
 /*
@@ -70,12 +71,12 @@ int ompi_file_init(void)
     /* Setup MPI_FILE_NULL.  Note that it will have the default error
        handler of MPI_ERRORS_RETURN, per MPI-2:9.7 (p265).  */
 
-    OBJ_CONSTRUCT(&ompi_mpi_file_null, ompi_file_t);
-    ompi_mpi_file_null.f_comm = &ompi_mpi_comm_null;
-    OBJ_RETAIN(ompi_mpi_file_null.f_comm);
-    ompi_mpi_file_null.f_f_to_c_index = 0;
+    OBJ_CONSTRUCT(&ompi_mpi_file_null.file, ompi_file_t);
+    ompi_mpi_file_null.file.f_comm = &ompi_mpi_comm_null.comm;
+    OBJ_RETAIN(ompi_mpi_file_null.file.f_comm);
+    ompi_mpi_file_null.file.f_f_to_c_index = 0;
     opal_pointer_array_set_item(&ompi_file_f_to_c_table, 0,
-                                &ompi_mpi_file_null);
+                                &ompi_mpi_file_null.file);
 
     /* All done */
 
@@ -145,7 +146,7 @@ int ompi_file_close(ompi_file_t **file)
     mca_io_base_component_del(&((*file)->f_io_selected_component));
     mca_io_base_request_return(*file);
     OBJ_RELEASE(*file);
-    *file = &ompi_mpi_file_null;
+    *file = &ompi_mpi_file_null.file;
 
     return OMPI_SUCCESS;
 }
@@ -164,7 +165,7 @@ int ompi_file_finalize(void)
        report on it.  Plus, it's statically allocated, so we don't want
      to call OBJ_RELEASE on it. */
 
-    OBJ_DESTRUCT(&ompi_mpi_file_null);
+    OBJ_DESTRUCT(&ompi_mpi_file_null.file);
     opal_pointer_array_set_item(&ompi_file_f_to_c_table, 0, NULL);
 
     /* Iterate through all the file handles and destroy them.  Note
@@ -239,10 +240,10 @@ static void file_constructor(ompi_file_t *file)
        MPI_FILE_NULL). */
 
     file->errhandler_type = OMPI_ERRHANDLER_TYPE_FILE;
-    if (file != &ompi_mpi_file_null) {
-        file->error_handler = ompi_mpi_file_null.error_handler;
+    if (file != &ompi_mpi_file_null.file) {
+        file->error_handler = ompi_mpi_file_null.file.error_handler;
     } else {
-        file->error_handler = &ompi_mpi_errors_return;
+        file->error_handler = &ompi_mpi_errors_return.eh;
     }
     OBJ_RETAIN(file->error_handler);
 
diff --git a/ompi/file/file.h b/ompi/file/file.h
index aa75751adf..815cb907a5 100644
--- a/ompi/file/file.h
+++ b/ompi/file/file.h
@@ -10,6 +10,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc.  All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -96,11 +97,23 @@ struct ompi_file_t {
  */
 typedef struct ompi_file_t ompi_file_t;
 
+/**
+ * Padded struct to maintain back compatibiltiy.
+ * See ompi/communicator/communicator.h comments with struct ompi_communicator_t
+ * for full explanation why we chose the following padding construct for predefines.
+ */
+#define PREDEFINED_FILE_PAD (sizeof(void*) * 192)
+
+struct ompi_predefined_file_t {
+    struct ompi_file_t file;
+    char padding[PREDEFINED_FILE_PAD - sizeof(ompi_file_t)];
+};
+typedef struct ompi_predefined_file_t ompi_predefined_file_t;
 
 /**
  * Back-end instances for MPI_FILE_NULL
  */
-OMPI_DECLSPEC extern ompi_file_t  ompi_mpi_file_null;
+OMPI_DECLSPEC extern ompi_predefined_file_t  ompi_mpi_file_null;
 
 
 /**
@@ -193,7 +206,7 @@ int ompi_file_finalize(void);
 static inline bool ompi_file_invalid(ompi_file_t *file)
 {
     return (NULL == file ||
-            &ompi_mpi_file_null == file ||
+            &ompi_mpi_file_null.file == file ||
             0 != (file->f_flags & OMPI_FILE_ISCLOSED));
 }
 
diff --git a/ompi/group/group.h b/ompi/group/group.h
index e8d80decad..86ca625c18 100644
--- a/ompi/group/group.h
+++ b/ompi/group/group.h
@@ -12,6 +12,7 @@
  *                         All rights reserved.
  * Copyright (c) 2006-2007 University of Houston. All rights reserved.
  * Copyright (c) 2007      Cisco Systems, Inc. All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc. All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -96,6 +97,19 @@ struct ompi_group_t {
 typedef struct ompi_group_t ompi_group_t;
 OMPI_DECLSPEC OBJ_CLASS_DECLARATION(ompi_group_t);
 
+/**
+ * Padded struct to maintain back compatibiltiy.
+ * See ompi/communicator/communicator.h comments with struct ompi_communicator_t
+ * for full explanation why we chose the following padding construct for predefines.
+ */
+#define PREDEFINED_GROUP_PAD (sizeof(void*) * 32)
+
+struct ompi_predefined_group_t {
+    struct ompi_group_t group;
+    char padding[PREDEFINED_GROUP_PAD - sizeof(ompi_group_t)];
+};
+
+typedef struct ompi_predefined_group_t ompi_predefined_group_t;
 
 /* Some definitions for the flags */
 #define OMPI_GROUP_ISFREED       0x00000001
@@ -122,11 +136,12 @@ OMPI_DECLSPEC OBJ_CLASS_DECLARATION(ompi_group_t);
  * Table for Fortran <-> C group handle conversion
  */
 OMPI_DECLSPEC extern struct opal_pointer_array_t ompi_group_f_to_c_table;
-OMPI_DECLSPEC extern ompi_group_t ompi_mpi_group_null;
+OMPI_DECLSPEC extern struct ompi_predefined_group_t ompi_mpi_group_null;
 
 
 /*
- * function prototypes
+ * function prototype
+s
  */
 
 /**
diff --git a/ompi/group/group_init.c b/ompi/group/group_init.c
index 1dcf730607..c157c6e191 100644
--- a/ompi/group/group_init.c
+++ b/ompi/group/group_init.c
@@ -12,6 +12,7 @@
  *                         All rights reserved.
  * Copyright (c) 2006-2007 University of Houston. All rights reserved.
  * Copyright (c) 2007      Cisco Systems, Inc. All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc. All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -41,8 +42,8 @@ opal_pointer_array_t ompi_group_f_to_c_table;
 /*
  * Predefined group objects
  */
-ompi_group_t ompi_mpi_group_empty;
-ompi_group_t ompi_mpi_group_null;
+ompi_predefined_group_t ompi_mpi_group_empty;
+ompi_predefined_group_t ompi_mpi_group_null;
 
 
 /*
@@ -313,19 +314,19 @@ int ompi_group_init(void)
     
     /* add MPI_GROUP_NULL to table */
     OBJ_CONSTRUCT(&ompi_mpi_group_null, ompi_group_t);
-    ompi_mpi_group_null.grp_proc_count        = 0;
-    ompi_mpi_group_null.grp_my_rank           = MPI_PROC_NULL;
-    ompi_mpi_group_null.grp_proc_pointers     = NULL;
-    ompi_mpi_group_null.grp_flags            |= OMPI_GROUP_DENSE;
-    ompi_mpi_group_null.grp_flags            |= OMPI_GROUP_INTRINSIC;
+    ompi_mpi_group_null.group.grp_proc_count        = 0;
+    ompi_mpi_group_null.group.grp_my_rank           = MPI_PROC_NULL;
+    ompi_mpi_group_null.group.grp_proc_pointers     = NULL;
+    ompi_mpi_group_null.group.grp_flags            |= OMPI_GROUP_DENSE;
+    ompi_mpi_group_null.group.grp_flags            |= OMPI_GROUP_INTRINSIC;
         
     /* add MPI_GROUP_EMPTRY to table */
     OBJ_CONSTRUCT(&ompi_mpi_group_empty, ompi_group_t);
-    ompi_mpi_group_empty.grp_proc_count        = 0;
-    ompi_mpi_group_empty.grp_my_rank           = MPI_UNDEFINED;
-    ompi_mpi_group_empty.grp_proc_pointers     = NULL;
-    ompi_mpi_group_empty.grp_flags            |= OMPI_GROUP_DENSE;
-    ompi_mpi_group_empty.grp_flags            |= OMPI_GROUP_INTRINSIC;
+    ompi_mpi_group_empty.group.grp_proc_count        = 0;
+    ompi_mpi_group_empty.group.grp_my_rank           = MPI_UNDEFINED;
+    ompi_mpi_group_empty.group.grp_proc_pointers     = NULL;
+    ompi_mpi_group_empty.group.grp_flags            |= OMPI_GROUP_DENSE;
+    ompi_mpi_group_empty.group.grp_flags            |= OMPI_GROUP_INTRINSIC;
         
     return OMPI_SUCCESS;
 }
@@ -336,10 +337,10 @@ int ompi_group_init(void)
  */
 int ompi_group_finalize(void)
 {
-    ompi_mpi_group_null.grp_flags = 0;
+    ompi_mpi_group_null.group.grp_flags = 0;
     OBJ_DESTRUCT(&ompi_mpi_group_null);
 
-    ompi_mpi_group_null.grp_flags = 0;
+    ompi_mpi_group_null.group.grp_flags = 0;
     OBJ_DESTRUCT(&ompi_mpi_group_empty);
 
     OBJ_DESTRUCT(&ompi_group_f_to_c_table);
diff --git a/ompi/include/mpi.h.in b/ompi/include/mpi.h.in
index fe0c66ab4e..a0db404c82 100644
--- a/ompi/include/mpi.h.in
+++ b/ompi/include/mpi.h.in
@@ -10,7 +10,7 @@
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
  * Copyright (c) 2007-2009 Cisco Systems, Inc.  All rights reserved.
- * Copyright (c) 2008      Sun Microsystems, Inc.  All rights reserved.
+ * Copyright (c) 2008-2009 Sun Microsystems, Inc.  All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -480,15 +480,15 @@ enum {
 /*
  * NULL handles
  */
-#define MPI_GROUP_NULL (&ompi_mpi_group_null)
-#define MPI_COMM_NULL (&ompi_mpi_comm_null)
-#define MPI_REQUEST_NULL (&ompi_request_null)
-#define MPI_OP_NULL (&ompi_mpi_op_null)
-#define MPI_ERRHANDLER_NULL (&ompi_mpi_errhandler_null)
-#define MPI_INFO_NULL (&ompi_mpi_info_null)
-#define MPI_WIN_NULL (&ompi_mpi_win_null)
+#define MPI_GROUP_NULL (((MPI_Group)&(ompi_mpi_group_null)))
+#define MPI_COMM_NULL (((MPI_Comm)&(ompi_mpi_comm_null)))
+#define MPI_REQUEST_NULL (((MPI_Request)&(ompi_request_null)))
+#define MPI_OP_NULL (((MPI_Op)&(ompi_mpi_op_null)))
+#define MPI_ERRHANDLER_NULL (((MPI_Errhandler)&(ompi_mpi_errhandler_null)))
+#define MPI_INFO_NULL (((MPI_Info)&(ompi_mpi_info_null)))
+#define MPI_WIN_NULL (((MPI_Win)&(ompi_mpi_win_null)))
 #if OMPI_PROVIDE_MPI_FILE_INTERFACE
-#define MPI_FILE_NULL (&ompi_mpi_file_null)
+#define MPI_FILE_NULL (((MPI_File)&(ompi_mpi_file_null)))
 #endif
 
 #define MPI_STATUS_IGNORE ((MPI_Status *) 0)
@@ -596,111 +596,119 @@ OMPI_DECLSPEC int OMPI_C_MPI_WIN_DUP_FN( MPI_Win window, int win_keyval,
                                          void* attribute_val_out,
                                          int* flag );
 
-
 /*
  * External variables
+ *
+ * The below externs use the ompi_predefined_xxx_t structures to maintain
+ * back compatibility between MPI library versions.
+ * See ompi/communicator/communicator.h comments with struct ompi_communicator_t
+ * for full explanation why we chose to use the ompi_predefined_xxx_t structure.
  */
-OMPI_DECLSPEC extern struct ompi_communicator_t ompi_mpi_comm_world;
-OMPI_DECLSPEC extern struct ompi_communicator_t ompi_mpi_comm_self;
-OMPI_DECLSPEC extern struct ompi_communicator_t ompi_mpi_comm_null;
+OMPI_DECLSPEC extern struct ompi_predefined_communicator_t ompi_mpi_comm_world;
+OMPI_DECLSPEC extern struct ompi_predefined_communicator_t ompi_mpi_comm_self;
+OMPI_DECLSPEC extern struct ompi_predefined_communicator_t ompi_mpi_comm_null;
 
-OMPI_DECLSPEC extern struct ompi_group_t ompi_mpi_group_empty;
-OMPI_DECLSPEC extern struct ompi_group_t ompi_mpi_group_null;
+OMPI_DECLSPEC extern struct ompi_predefined_group_t ompi_mpi_group_empty;
+OMPI_DECLSPEC extern struct ompi_predefined_group_t ompi_mpi_group_null;
 
-OMPI_DECLSPEC extern struct ompi_request_t ompi_request_null;
+OMPI_DECLSPEC extern struct ompi_predefined_request_t ompi_request_null;
 
-OMPI_DECLSPEC extern struct ompi_op_t ompi_mpi_op_null;
-OMPI_DECLSPEC extern struct ompi_op_t ompi_mpi_op_max, ompi_mpi_op_min;
-OMPI_DECLSPEC extern struct ompi_op_t ompi_mpi_op_sum, ompi_mpi_op_prod;
-OMPI_DECLSPEC extern struct ompi_op_t ompi_mpi_op_land, ompi_mpi_op_band;
-OMPI_DECLSPEC extern struct ompi_op_t ompi_mpi_op_lor, ompi_mpi_op_bor;
-OMPI_DECLSPEC extern struct ompi_op_t ompi_mpi_op_lxor, ompi_mpi_op_bxor;
-OMPI_DECLSPEC extern struct ompi_op_t ompi_mpi_op_maxloc, ompi_mpi_op_minloc;
-OMPI_DECLSPEC extern struct ompi_op_t ompi_mpi_op_replace;
+OMPI_DECLSPEC extern struct ompi_predefined_op_t ompi_mpi_op_null;
+OMPI_DECLSPEC extern struct ompi_predefined_op_t ompi_mpi_op_max, ompi_mpi_op_min;
+OMPI_DECLSPEC extern struct ompi_predefined_op_t ompi_mpi_op_sum;
+OMPI_DECLSPEC extern struct ompi_predefined_op_t ompi_mpi_op_prod;
+OMPI_DECLSPEC extern struct ompi_predefined_op_t ompi_mpi_op_land;
+OMPI_DECLSPEC extern struct ompi_predefined_op_t ompi_mpi_op_band;
+OMPI_DECLSPEC extern struct ompi_predefined_op_t ompi_mpi_op_lor, ompi_mpi_op_bor;
+OMPI_DECLSPEC extern struct ompi_predefined_op_t ompi_mpi_op_lxor;
+OMPI_DECLSPEC extern struct ompi_predefined_op_t ompi_mpi_op_bxor;
+OMPI_DECLSPEC extern struct ompi_predefined_op_t ompi_mpi_op_maxloc;
+OMPI_DECLSPEC extern struct ompi_predefined_op_t ompi_mpi_op_minloc;
+OMPI_DECLSPEC extern struct ompi_predefined_op_t ompi_mpi_op_replace;
 
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_char, ompi_mpi_byte;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_int, ompi_mpi_logic;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_short, ompi_mpi_long;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_float, ompi_mpi_double;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_long_double;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_cplex, ompi_mpi_packed;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_signed_char;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_unsigned_char;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_unsigned_short;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_unsigned, ompi_mpi_datatype_null;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_unsigned_long, ompi_mpi_ldblcplex;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_ub, ompi_mpi_lb;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_float_int, ompi_mpi_double_int;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_long_int, ompi_mpi_2int;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_short_int, ompi_mpi_dblcplex;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_integer, ompi_mpi_real;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_dblprec, ompi_mpi_character;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_2real, ompi_mpi_2dblprec;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_2integer, ompi_mpi_longdbl_int;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_wchar, ompi_mpi_long_long_int;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_unsigned_long_long;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_cxx_cplex, ompi_mpi_cxx_dblcplex;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_cxx_ldblcplex;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_cxx_bool;
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_2cplex, ompi_mpi_2dblcplex;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_char, ompi_mpi_byte;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_int, ompi_mpi_logic;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_short, ompi_mpi_long;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_float, ompi_mpi_double;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_long_double;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_cplex, ompi_mpi_packed;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_signed_char;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_unsigned_char;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_unsigned_short;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_unsigned, ompi_mpi_datatype_null;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_unsigned_long, ompi_mpi_ldblcplex;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_ub, ompi_mpi_lb;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_float_int, ompi_mpi_double_int;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_long_int, ompi_mpi_2int;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_short_int, ompi_mpi_dblcplex;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_integer, ompi_mpi_real;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_dblprec, ompi_mpi_character;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_2real, ompi_mpi_2dblprec;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_2integer, ompi_mpi_longdbl_int;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_wchar, ompi_mpi_long_long_int;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_unsigned_long_long;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_cxx_cplex, ompi_mpi_cxx_dblcplex;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_cxx_ldblcplex;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_cxx_bool;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_2cplex, ompi_mpi_2dblcplex;
 /* other MPI2 datatypes */
 #if OMPI_HAVE_FORTRAN_LOGICAL1
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_logical1;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_logical1;
 #endif
 #if OMPI_HAVE_FORTRAN_LOGICAL2
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_logical2;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_logical2;
 #endif
 #if OMPI_HAVE_FORTRAN_LOGICAL4
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_logical4;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_logical4;
 #endif
 #if OMPI_HAVE_FORTRAN_LOGICAL8
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_logical8;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_logical8;
 #endif
 #if OMPI_HAVE_FORTRAN_INTEGER1
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_integer1;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_integer1;
 #endif
 #if OMPI_HAVE_FORTRAN_INTEGER2
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_integer2;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_integer2;
 #endif
 #if OMPI_HAVE_FORTRAN_INTEGER4
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_integer4;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_integer4;
 #endif
 #if OMPI_HAVE_FORTRAN_INTEGER8
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_integer8;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_integer8;
 #endif
 #if OMPI_HAVE_FORTRAN_INTEGER16
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_integer16;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_integer16;
 #endif
 #if OMPI_HAVE_FORTRAN_REAL2
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_real2;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_real2;
 #endif
 #if OMPI_HAVE_FORTRAN_REAL4
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_real4; 
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_real4; 
 #endif
 #if OMPI_HAVE_FORTRAN_REAL8
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_real8;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_real8;
 #endif
 #if OMPI_HAVE_FORTRAN_REAL16
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_real16;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_real16;
 #endif
 #if OMPI_HAVE_FORTRAN_REAL4
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_complex8;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_complex8;
 #endif
 #if OMPI_HAVE_FORTRAN_REAL8
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_complex16;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_complex16;
 #endif
 #if OMPI_HAVE_FORTRAN_REAL16
-OMPI_DECLSPEC extern struct ompi_datatype_t ompi_mpi_complex32;
+OMPI_DECLSPEC extern struct ompi_predefined_datatype_t ompi_mpi_complex32;
 #endif
 
-OMPI_DECLSPEC extern struct ompi_errhandler_t ompi_mpi_errhandler_null;
-OMPI_DECLSPEC extern struct ompi_errhandler_t ompi_mpi_errors_are_fatal;
-OMPI_DECLSPEC extern struct ompi_errhandler_t ompi_mpi_errors_return;
+OMPI_DECLSPEC extern struct ompi_predefined_errhandler_t ompi_mpi_errhandler_null;
+OMPI_DECLSPEC extern struct ompi_predefined_errhandler_t ompi_mpi_errors_are_fatal;
+OMPI_DECLSPEC extern struct ompi_predefined_errhandler_t ompi_mpi_errors_return;
 
-OMPI_DECLSPEC extern struct ompi_win_t ompi_mpi_win_null;
-OMPI_DECLSPEC extern struct ompi_file_t ompi_mpi_file_null;
+OMPI_DECLSPEC extern struct ompi_predefined_win_t ompi_mpi_win_null;
+OMPI_DECLSPEC extern struct ompi_predefined_file_t ompi_mpi_file_null;
 
-OMPI_DECLSPEC extern struct ompi_info_t ompi_mpi_info_null;
+OMPI_DECLSPEC extern struct ompi_predefined_info_t ompi_mpi_info_null;
 
 OMPI_DECLSPEC extern MPI_Fint *MPI_F_STATUS_IGNORE;
 OMPI_DECLSPEC extern MPI_Fint *MPI_F_STATUSES_IGNORE;
@@ -708,117 +716,117 @@ OMPI_DECLSPEC extern MPI_Fint *MPI_F_STATUSES_IGNORE;
 /*
  * MPI predefined handles
  */
-#define MPI_COMM_WORLD (&ompi_mpi_comm_world)
-#define MPI_COMM_SELF (&ompi_mpi_comm_self)
+#define MPI_COMM_WORLD (((MPI_Comm)&(ompi_mpi_comm_world)))
+#define MPI_COMM_SELF (((MPI_Comm)&(ompi_mpi_comm_self)))
 
-#define MPI_GROUP_EMPTY (&ompi_mpi_group_empty)
+#define MPI_GROUP_EMPTY (((MPI_Group)&(ompi_mpi_group_empty)))
 
-#define MPI_MAX (&ompi_mpi_op_max)
-#define MPI_MIN (&ompi_mpi_op_min)
-#define MPI_SUM (&ompi_mpi_op_sum)
-#define MPI_PROD (&ompi_mpi_op_prod)
-#define MPI_LAND (&ompi_mpi_op_land)
-#define MPI_BAND (&ompi_mpi_op_band)
-#define MPI_LOR (&ompi_mpi_op_lor)
-#define MPI_BOR (&ompi_mpi_op_bor)
-#define MPI_LXOR (&ompi_mpi_op_lxor)
-#define MPI_BXOR (&ompi_mpi_op_bxor)
-#define MPI_MAXLOC (&ompi_mpi_op_maxloc)
-#define MPI_MINLOC (&ompi_mpi_op_minloc)
-#define MPI_REPLACE (&ompi_mpi_op_replace)
+#define MPI_MAX (((MPI_Op)&(ompi_mpi_op_max)))
+#define MPI_MIN (((MPI_Op)&(ompi_mpi_op_min)))
+#define MPI_SUM (((MPI_Op)&(ompi_mpi_op_sum)))
+#define MPI_PROD (((MPI_Op)&(ompi_mpi_op_prod)))
+#define MPI_LAND (((MPI_Op)&(ompi_mpi_op_land)))
+#define MPI_BAND (((MPI_Op)&(ompi_mpi_op_band)))
+#define MPI_LOR (((MPI_Op)&(ompi_mpi_op_lor)))
+#define MPI_BOR (((MPI_Op)&(ompi_mpi_op_bor)))
+#define MPI_LXOR (((MPI_Op)&(ompi_mpi_op_lxor)))
+#define MPI_BXOR (((MPI_Op)&(ompi_mpi_op_bxor)))
+#define MPI_MAXLOC (((MPI_Op)&(ompi_mpi_op_maxloc)))
+#define MPI_MINLOC (((MPI_Op)&(ompi_mpi_op_minloc)))
+#define MPI_REPLACE (((MPI_Op)&(ompi_mpi_op_replace)))
 
 /* C datatypes */
-#define MPI_DATATYPE_NULL (&ompi_mpi_datatype_null)
-#define MPI_BYTE (&ompi_mpi_byte)
-#define MPI_PACKED (&ompi_mpi_packed)
-#define MPI_CHAR (&ompi_mpi_char)
-#define MPI_SHORT (&ompi_mpi_short)
-#define MPI_INT (&ompi_mpi_int)
-#define MPI_LONG (&ompi_mpi_long)
-#define MPI_FLOAT (&ompi_mpi_float)
-#define MPI_DOUBLE (&ompi_mpi_double)
-#define MPI_LONG_DOUBLE (&ompi_mpi_long_double)
-#define MPI_UNSIGNED_CHAR (&ompi_mpi_unsigned_char)
-#define MPI_SIGNED_CHAR (&ompi_mpi_signed_char)
-#define MPI_UNSIGNED_SHORT (&ompi_mpi_unsigned_short)
-#define MPI_UNSIGNED_LONG (&ompi_mpi_unsigned_long)
-#define MPI_UNSIGNED (&ompi_mpi_unsigned)
-#define MPI_FLOAT_INT (&ompi_mpi_float_int)
-#define MPI_DOUBLE_INT (&ompi_mpi_double_int)
-#define MPI_LONG_DOUBLE_INT (&ompi_mpi_longdbl_int)
-#define MPI_LONG_INT (&ompi_mpi_long_int)
-#define MPI_SHORT_INT (&ompi_mpi_short_int)
-#define MPI_2INT (&ompi_mpi_2int)
-#define MPI_UB (&ompi_mpi_ub)
-#define MPI_LB (&ompi_mpi_lb)
-#define MPI_WCHAR (&ompi_mpi_wchar)
+#define MPI_DATATYPE_NULL (((MPI_Datatype)&(ompi_mpi_datatype_null)))
+#define MPI_BYTE (((MPI_Datatype)&(ompi_mpi_byte)))
+#define MPI_PACKED (((MPI_Datatype)&(ompi_mpi_packed)))
+#define MPI_CHAR (((MPI_Datatype)&(ompi_mpi_char)))
+#define MPI_SHORT (((MPI_Datatype)&(ompi_mpi_short)))
+#define MPI_INT (((MPI_Datatype)&(ompi_mpi_int)))
+#define MPI_LONG (((MPI_Datatype)&(ompi_mpi_long)))
+#define MPI_FLOAT (((MPI_Datatype)&(ompi_mpi_float)))
+#define MPI_DOUBLE (((MPI_Datatype)&(ompi_mpi_double)))
+#define MPI_LONG_DOUBLE (((MPI_Datatype)&(ompi_mpi_long_double)))
+#define MPI_UNSIGNED_CHAR (((MPI_Datatype)&(ompi_mpi_unsigned_char)))
+#define MPI_SIGNED_CHAR (((MPI_Datatype)&(ompi_mpi_signed_char)))
+#define MPI_UNSIGNED_SHORT (((MPI_Datatype)&(ompi_mpi_unsigned_short)))
+#define MPI_UNSIGNED_LONG (((MPI_Datatype)&(ompi_mpi_unsigned_long)))
+#define MPI_UNSIGNED (((MPI_Datatype)&(ompi_mpi_unsigned)))
+#define MPI_FLOAT_INT (((MPI_Datatype)&(ompi_mpi_float_int)))
+#define MPI_DOUBLE_INT (((MPI_Datatype)&(ompi_mpi_double_int)))
+#define MPI_LONG_DOUBLE_INT (((MPI_Datatype)&(ompi_mpi_longdbl_int)))
+#define MPI_LONG_INT (((MPI_Datatype)&(ompi_mpi_long_int)))
+#define MPI_SHORT_INT (((MPI_Datatype)&(ompi_mpi_short_int)))
+#define MPI_2INT (((MPI_Datatype)&(ompi_mpi_2int)))
+#define MPI_UB (((MPI_Datatype)&(ompi_mpi_ub)))
+#define MPI_LB (((MPI_Datatype)&(ompi_mpi_lb)))
+#define MPI_WCHAR (((MPI_Datatype)&(ompi_mpi_wchar)))
 #if OMPI_HAVE_LONG_LONG
-#define MPI_LONG_LONG_INT (&ompi_mpi_long_long_int)
-#define MPI_LONG_LONG (&ompi_mpi_long_long_int)
-#define MPI_UNSIGNED_LONG_LONG (&ompi_mpi_unsigned_long_long)
+#define MPI_LONG_LONG_INT (((MPI_Datatype)&(ompi_mpi_long_long_int)))
+#define MPI_LONG_LONG (((MPI_Datatype)&(ompi_mpi_long_long_int)))
+#define MPI_UNSIGNED_LONG_LONG (((MPI_Datatype)&(ompi_mpi_unsigned_long_long)))
 #endif  /* OMPI_HAVE_LONG_LONG */
-#define MPI_2COMPLEX (&ompi_mpi_2cplex)
-#define MPI_2DOUBLE_COMPLEX (&ompi_mpi_2dblcplex)
+#define MPI_2COMPLEX (((MPI_Datatype)&(ompi_mpi_2cplex)))
+#define MPI_2DOUBLE_COMPLEX (((MPI_Datatype)&(ompi_mpi_2dblcplex)))
 
 /* Fortran datatype bindings */
-#define MPI_CHARACTER (&ompi_mpi_character)
-#define MPI_LOGICAL (&ompi_mpi_logic)
+#define MPI_CHARACTER (((MPI_Datatype)&(ompi_mpi_character)))
+#define MPI_LOGICAL (((MPI_Datatype)&(ompi_mpi_logic)))
 #if OMPI_HAVE_FORTRAN_LOGICAL1
-#define MPI_LOGICAL1 (&ompi_mpi_logical1)
+#define MPI_LOGICAL1 (((MPI_Datatype)&(ompi_mpi_logical1)))
 #endif
 #if OMPI_HAVE_FORTRAN_LOGICAL2
-#define MPI_LOGICAL2 (&ompi_mpi_logical2)
+#define MPI_LOGICAL2 (((MPI_Datatype)&(ompi_mpi_logical2)))
 #endif
 #if OMPI_HAVE_FORTRAN_LOGICAL4
-#define MPI_LOGICAL4 (&ompi_mpi_logical4)
+#define MPI_LOGICAL4 (((MPI_Datatype)&(ompi_mpi_logical4)))
 #endif
 #if OMPI_HAVE_FORTRAN_LOGICAL8
-#define MPI_LOGICAL8 (&ompi_mpi_logical8)
+#define MPI_LOGICAL8 (((MPI_Datatype)&(ompi_mpi_logical8)))
 #endif
-#define MPI_INTEGER (&ompi_mpi_integer)
+#define MPI_INTEGER (((MPI_Datatype)&(ompi_mpi_integer)))
 #if OMPI_HAVE_FORTRAN_INTEGER1
-#define MPI_INTEGER1 (&ompi_mpi_integer1)
+#define MPI_INTEGER1 (((MPI_Datatype)&(ompi_mpi_integer1)))
 #endif
 #if OMPI_HAVE_FORTRAN_INTEGER2
-#define MPI_INTEGER2 (&ompi_mpi_integer2)
+#define MPI_INTEGER2 (((MPI_Datatype)&(ompi_mpi_integer2)))
 #endif
 #if OMPI_HAVE_FORTRAN_INTEGER4
-#define MPI_INTEGER4 (&ompi_mpi_integer4)
+#define MPI_INTEGER4 (((MPI_Datatype)&(ompi_mpi_integer4)))
 #endif
 #if OMPI_HAVE_FORTRAN_INTEGER8
-#define MPI_INTEGER8 (&ompi_mpi_integer8)
+#define MPI_INTEGER8 (((MPI_Datatype)&(ompi_mpi_integer8)))
 #endif
 #if OMPI_HAVE_FORTRAN_INTEGER16
-#define MPI_INTEGER16 (&ompi_mpi_integer16)
+#define MPI_INTEGER16 (((MPI_Datatype)&(ompi_mpi_integer16)))
 #endif
-#define MPI_REAL (&ompi_mpi_real)
+#define MPI_REAL (((MPI_Datatype)&(ompi_mpi_real)))
 #if OMPI_HAVE_FORTRAN_REAL4
-#define MPI_REAL4 (&ompi_mpi_real4)
+#define MPI_REAL4 (((MPI_Datatype)&(ompi_mpi_real4)))
 #endif
 #if OMPI_HAVE_FORTRAN_REAL8
-#define MPI_REAL8 (&ompi_mpi_real8)
+#define MPI_REAL8 (((MPI_Datatype)&(ompi_mpi_real8)))
 #endif
 #if OMPI_HAVE_FORTRAN_REAL16
-#define MPI_REAL16 (&ompi_mpi_real16)
+#define MPI_REAL16 (((MPI_Datatype)&(ompi_mpi_real16)))
 #endif
-#define MPI_DOUBLE_PRECISION (&ompi_mpi_dblprec)
-#define MPI_COMPLEX (&ompi_mpi_cplex)
+#define MPI_DOUBLE_PRECISION (((MPI_Datatype)&(ompi_mpi_dblprec)))
+#define MPI_COMPLEX (((MPI_Datatype)&(ompi_mpi_cplex)))
 #if OMPI_HAVE_FORTRAN_REAL4
-#define MPI_COMPLEX8 (&ompi_mpi_complex8)
+#define MPI_COMPLEX8 (((MPI_Datatype)&(ompi_mpi_complex8)))
 #endif
 #if OMPI_HAVE_FORTRAN_REAL8
-#define MPI_COMPLEX16 (&ompi_mpi_complex16)
+#define MPI_COMPLEX16 (((MPI_Datatype)&(ompi_mpi_complex16)))
 #endif
 #if OMPI_HAVE_FORTRAN_REAL16
-#define MPI_COMPLEX32 (&ompi_mpi_complex32)
+#define MPI_COMPLEX32 (((MPI_Datatype)&(ompi_mpi_complex32)))
 #endif
-#define MPI_DOUBLE_COMPLEX (&ompi_mpi_dblcplex)
-#define MPI_2REAL (&ompi_mpi_2real)
-#define MPI_2DOUBLE_PRECISION (&ompi_mpi_2dblprec)
-#define MPI_2INTEGER (&ompi_mpi_2integer)
+#define MPI_DOUBLE_COMPLEX (((MPI_Datatype)&(ompi_mpi_dblcplex)))
+#define MPI_2REAL (((MPI_Datatype)&(ompi_mpi_2real)))
+#define MPI_2DOUBLE_PRECISION (((MPI_Datatype)&(ompi_mpi_2dblprec)))
+#define MPI_2INTEGER (((MPI_Datatype)&(ompi_mpi_2integer)))
 
-#define MPI_ERRORS_ARE_FATAL (&ompi_mpi_errors_are_fatal)
-#define MPI_ERRORS_RETURN (&ompi_mpi_errors_return)
+#define MPI_ERRORS_ARE_FATAL (((MPI_Errhandler)&(ompi_mpi_errors_are_fatal)))
+#define MPI_ERRORS_RETURN (((MPI_Errhandler)&(ompi_mpi_errors_return)))
 
 /* Typeclass definition for MPI_Type_match_size */
 #define MPI_TYPECLASS_INTEGER    1
@@ -992,7 +1000,7 @@ OMPI_DECLSPEC  int MPI_File_get_byte_offset(MPI_File fh, MPI_Offset offset,
 OMPI_DECLSPEC  int MPI_File_read_shared(MPI_File fh, void *buf, int count,
                                         MPI_Datatype datatype, MPI_Status *status);
 OMPI_DECLSPEC  int MPI_File_write_shared(MPI_File fh, void *buf, int count,
-                                         MPI_Datatype datatype, MPI_Status *status);
+					 MPI_Datatype datatype, MPI_Status *status);
 OMPI_DECLSPEC  int MPI_File_iread_shared(MPI_File fh, void *buf, int count,
                                          MPI_Datatype datatype, MPI_Request *request);
 OMPI_DECLSPEC  int MPI_File_iwrite_shared(MPI_File fh, void *buf, int count,
diff --git a/ompi/info/info.c b/ompi/info/info.c
index 5f158ade94..0b2484611c 100644
--- a/ompi/info/info.c
+++ b/ompi/info/info.c
@@ -11,6 +11,7 @@
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
  * Copyright (c) 2007      Cisco Systems, Inc.  All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc.  All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -39,7 +40,7 @@
 /*
  * Global variables
  */
-ompi_info_t ompi_mpi_info_null;
+ompi_predefined_info_t ompi_mpi_info_null;
 
 
 /*
@@ -89,8 +90,8 @@ int ompi_info_init(void)
 
     /* Create MPI_INFO_NULL */
 
-    OBJ_CONSTRUCT(&ompi_mpi_info_null, ompi_info_t);
-    ompi_mpi_info_null.i_f_to_c_index = 0;
+    OBJ_CONSTRUCT(&ompi_mpi_info_null.info, ompi_info_t);
+    ompi_mpi_info_null.info.i_f_to_c_index = 0;
 
     /* All done */
 
@@ -348,7 +349,7 @@ int ompi_info_finalize(void)
        leak report on it.  Plus, it's statically allocated, so we
        don't want to call OBJ_RELEASE on it. */
     
-    OBJ_DESTRUCT(&ompi_mpi_info_null);
+    OBJ_DESTRUCT(&ompi_mpi_info_null.info);
     opal_pointer_array_set_item(&ompi_info_f_to_c_table, 0, NULL);
     
     /* Go through the f2c table and see if anything is left.  Free them
diff --git a/ompi/info/info.h b/ompi/info/info.h
index b2408b731d..24135c913c 100644
--- a/ompi/info/info.h
+++ b/ompi/info/info.h
@@ -11,6 +11,7 @@
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
  * Copyright (c) 2007      Cisco Systems, Inc.  All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc.  All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -52,6 +53,20 @@ struct ompi_info_t {
  */
 typedef struct ompi_info_t ompi_info_t;
 
+/**
+ * Padded struct to maintain back compatibiltiy.
+ * See ompi/communicator/communicator.h comments with struct ompi_communicator_t
+ * for full explanation why we chose the following padding construct for predefines.
+ */
+#define PREDEFINED_INFO_PAD (sizeof(void*) * 32)
+
+struct ompi_predefined_info_t {
+    struct ompi_info_t info;
+    char padding[PREDEFINED_INFO_PAD - sizeof(ompi_info_t)];
+};
+typedef struct ompi_predefined_info_t ompi_predefined_info_t;
+
+
 /**
  * \internal
  *
@@ -81,7 +96,7 @@ extern opal_pointer_array_t ompi_info_f_to_c_table;
 /**
  * Global instance for MPI_INFO_NULL
  */
-OMPI_DECLSPEC extern ompi_info_t ompi_mpi_info_null;
+OMPI_DECLSPEC extern ompi_predefined_info_t ompi_mpi_info_null;
 
 /**
  * \internal
diff --git a/ompi/mca/coll/tuned/coll_tuned_module.c b/ompi/mca/coll/tuned/coll_tuned_module.c
index 36eff0eb12..29256bbe1d 100644
--- a/ompi/mca/coll/tuned/coll_tuned_module.c
+++ b/ompi/mca/coll/tuned/coll_tuned_module.c
@@ -261,7 +261,7 @@ tuned_module_enable(mca_coll_base_module_t *module,
     }
 
 
-    if (&ompi_mpi_comm_world==comm) {
+    if (&ompi_mpi_comm_world.comm==comm) {
         if (ompi_coll_tuned_use_dynamic_rules) {
             OPAL_OUTPUT((ompi_coll_tuned_stream,"coll:tuned:module_init MCW & Dynamic"));
             if (ompi_coll_tuned_dynamic_rules_filename) {
diff --git a/ompi/mca/dpm/orte/dpm_orte.c b/ompi/mca/dpm/orte/dpm_orte.c
index 9a654c3d8e..1eb1a42b9a 100644
--- a/ompi/mca/dpm/orte/dpm_orte.c
+++ b/ompi/mca/dpm/orte/dpm_orte.c
@@ -11,6 +11,7 @@
  *                         All rights reserved.
  * Copyright (c) 2007      Cisco Systems, Inc.  All rights reserved.
  * Copyright (c) 2006-2008 University of Houston.  All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc.  All rights reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -42,6 +43,7 @@
 #include "orte/runtime/orte_wait.h"
 
 #include "ompi/communicator/communicator.h"
+#include "ompi/group/group.h"
 #include "ompi/proc/proc.h"
 #include "ompi/mca/pml/pml.h"
 #include "ompi/info/info.h"
@@ -931,11 +933,11 @@ static int dyn_init(void)
      * objects
      */
     
-    oldcomm = &ompi_mpi_comm_null;
+    oldcomm = &ompi_mpi_comm_null.comm;
     OBJ_RELEASE(oldcomm);
-    group = &ompi_mpi_group_null;
+    group = &ompi_mpi_group_null.group;
     OBJ_RELEASE(group);
-    errhandler = &ompi_mpi_errors_are_fatal;
+    errhandler = &ompi_mpi_errors_are_fatal.eh;
     OBJ_RELEASE(errhandler);
     
     /* Set name for debugging purposes */
diff --git a/ompi/mca/mpool/base/mpool_base_alloc.c b/ompi/mca/mpool/base/mpool_base_alloc.c
index 89c87e0a89..d0805c8627 100644
--- a/ompi/mca/mpool/base/mpool_base_alloc.c
+++ b/ompi/mca/mpool/base/mpool_base_alloc.c
@@ -9,6 +9,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc.  All rights reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -125,7 +126,7 @@ void *mca_mpool_base_alloc(size_t size, ompi_info_t *info)
     mpool_tree_item->num_bytes = size;
     mpool_tree_item->count = 0;
     
-    if(&ompi_mpi_info_null == info)
+    if(&ompi_mpi_info_null.info == info)
     {
         for(item = opal_list_get_first(&mca_mpool_base_modules);
             item != opal_list_get_end(&mca_mpool_base_modules);
diff --git a/ompi/mca/osc/base/osc_base_obj_convert.c b/ompi/mca/osc/base/osc_base_obj_convert.c
index ee29a919b0..01b744c6a6 100644
--- a/ompi/mca/osc/base/osc_base_obj_convert.c
+++ b/ompi/mca/osc/base/osc_base_obj_convert.c
@@ -9,6 +9,7 @@
  *                         All rights reserved.
  * Copyright (c) 2007      Los Alamos National Security, LLC.  All rights
  *                         reserved. 
+ * Copyright (c) 2009      Sun Microsystems, Inc. All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -187,7 +188,7 @@ ompi_osc_base_process_op(void *outbuf,
                          int count,
                          ompi_op_t *op)
 {
-    if (op == &ompi_mpi_op_replace) {
+    if (op == &ompi_mpi_op_replace.op) {
         return OMPI_ERR_NOT_SUPPORTED;
     }
 
diff --git a/ompi/mca/osc/pt2pt/osc_pt2pt_data_move.c b/ompi/mca/osc/pt2pt/osc_pt2pt_data_move.c
index 986cb84f47..b6447a80ac 100644
--- a/ompi/mca/osc/pt2pt/osc_pt2pt_data_move.c
+++ b/ompi/mca/osc/pt2pt/osc_pt2pt_data_move.c
@@ -7,7 +7,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
- * Copyright (c) 2008      Sun Microsystems, Inc.  All rights reserved.
+ * Copyright (c) 2008-2009 Sun Microsystems, Inc.  All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -28,6 +28,7 @@
 #include "opal/sys/atomic.h"
 #include "ompi/mca/pml/pml.h"
 #include "ompi/datatype/datatype.h"
+#include "ompi/op/op.h"
 #include "ompi/mca/osc/base/base.h"
 #include "ompi/mca/osc/base/osc_base_obj_convert.h"
 #include "ompi/memchecker.h"
@@ -660,7 +661,7 @@ ompi_osc_pt2pt_sendreq_recv_accum_long_cb(ompi_osc_pt2pt_mpireq_t *mpireq)
     /* lock the window for accumulates */
     OPAL_THREAD_LOCK(&longreq->req_module->p2p_acc_lock);
 
-    if (longreq->req_op == &ompi_mpi_op_replace) {
+    if (longreq->req_op == &ompi_mpi_op_replace.op) {
         ompi_convertor_t convertor;
         struct iovec iov;
         uint32_t iov_count = 1;
@@ -750,7 +751,7 @@ ompi_osc_pt2pt_sendreq_recv_accum(ompi_osc_pt2pt_module_t *module,
         /* lock the window for accumulates */
         OPAL_THREAD_LOCK(&module->p2p_acc_lock);
 
-        if (op == &ompi_mpi_op_replace) {
+        if (op == &ompi_mpi_op_replace.op) {
             ompi_convertor_t convertor;
             struct iovec iov;
             uint32_t iov_count = 1;
diff --git a/ompi/mca/osc/rdma/osc_rdma_data_move.c b/ompi/mca/osc/rdma/osc_rdma_data_move.c
index 4c9ba97c48..1d3d8a4da3 100644
--- a/ompi/mca/osc/rdma/osc_rdma_data_move.c
+++ b/ompi/mca/osc/rdma/osc_rdma_data_move.c
@@ -9,6 +9,7 @@
  *                         All rights reserved.
  * Copyright (c) 2007      Los Alamos National Security, LLC.  All rights
  *                         reserved. 
+ * Copyright (c) 2009      Sun Microsystems, Inc.  All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -33,6 +34,7 @@
 #include "ompi/mca/osc/base/base.h"
 #include "ompi/mca/osc/base/osc_base_obj_convert.h"
 #include "ompi/datatype/datatype.h"
+#include "ompi/op/op.h"
 #include "ompi/memchecker.h"
 
 static inline int32_t
@@ -918,7 +920,7 @@ ompi_osc_rdma_sendreq_recv_accum_long_cb(ompi_osc_rdma_longreq_t *longreq)
     /* lock the window for accumulates */
     OPAL_THREAD_LOCK(&longreq->req_module->m_acc_lock);
 
-    if (longreq->req_op == &ompi_mpi_op_replace) {
+    if (longreq->req_op == &ompi_mpi_op_replace.op) {
         ompi_convertor_t convertor;
         struct iovec iov;
         uint32_t iov_count = 1;
@@ -1008,7 +1010,7 @@ ompi_osc_rdma_sendreq_recv_accum(ompi_osc_rdma_module_t *module,
         /* lock the window for accumulates */
         OPAL_THREAD_LOCK(&module->m_acc_lock);
 
-        if (op == &ompi_mpi_op_replace) {
+        if (op == &ompi_mpi_op_replace.op) {
             ompi_convertor_t convertor;
             struct iovec iov;
             uint32_t iov_count = 1;
diff --git a/ompi/mca/pml/dr/pml_dr_iprobe.c b/ompi/mca/pml/dr/pml_dr_iprobe.c
index 2063c54c1c..019b592962 100644
--- a/ompi/mca/pml/dr/pml_dr_iprobe.c
+++ b/ompi/mca/pml/dr/pml_dr_iprobe.c
@@ -9,6 +9,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2006 The Regents of the University of California.
  *                         All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc. All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -33,7 +34,7 @@ int mca_pml_dr_iprobe(int src,
     recvreq.req_recv.req_base.req_ompi.req_type = OMPI_REQUEST_PML;
     recvreq.req_recv.req_base.req_type = MCA_PML_REQUEST_IPROBE;
 
-    MCA_PML_DR_RECV_REQUEST_INIT(&recvreq, NULL, 0, &ompi_mpi_char, src, tag, comm, true);
+    MCA_PML_DR_RECV_REQUEST_INIT(&recvreq, NULL, 0, &ompi_mpi_char.dt, src, tag, comm, true);
     MCA_PML_DR_RECV_REQUEST_START(&recvreq);
 
     if( recvreq.req_recv.req_base.req_ompi.req_complete == true ) {
@@ -61,7 +62,7 @@ int mca_pml_dr_probe(int src,
     recvreq.req_recv.req_base.req_ompi.req_type = OMPI_REQUEST_PML;
     recvreq.req_recv.req_base.req_type = MCA_PML_REQUEST_PROBE;
 
-    MCA_PML_DR_RECV_REQUEST_INIT(&recvreq, NULL, 0, &ompi_mpi_char, src, tag, comm, true);
+    MCA_PML_DR_RECV_REQUEST_INIT(&recvreq, NULL, 0, &ompi_mpi_char.dt, src, tag, comm, true);
     MCA_PML_DR_RECV_REQUEST_START(&recvreq);
 
     ompi_request_wait_completion(&recvreq.req_recv.req_base.req_ompi);
diff --git a/ompi/mca/pml/ob1/pml_ob1_iprobe.c b/ompi/mca/pml/ob1/pml_ob1_iprobe.c
index c86f1c74df..b2f1d69613 100644
--- a/ompi/mca/pml/ob1/pml_ob1_iprobe.c
+++ b/ompi/mca/pml/ob1/pml_ob1_iprobe.c
@@ -9,6 +9,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc. All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -33,7 +34,7 @@ int mca_pml_ob1_iprobe(int src,
     recvreq.req_recv.req_base.req_ompi.req_type = OMPI_REQUEST_PML;
     recvreq.req_recv.req_base.req_type = MCA_PML_REQUEST_IPROBE;
 
-    MCA_PML_OB1_RECV_REQUEST_INIT(&recvreq, NULL, 0, &ompi_mpi_char, src, tag, comm, true);
+    MCA_PML_OB1_RECV_REQUEST_INIT(&recvreq, NULL, 0, &ompi_mpi_char.dt, src, tag, comm, true);
     MCA_PML_OB1_RECV_REQUEST_START(&recvreq);
 
     if( recvreq.req_recv.req_base.req_ompi.req_complete == true ) {
@@ -61,7 +62,7 @@ int mca_pml_ob1_probe(int src,
     recvreq.req_recv.req_base.req_ompi.req_type = OMPI_REQUEST_PML;
     recvreq.req_recv.req_base.req_type = MCA_PML_REQUEST_PROBE;
 
-    MCA_PML_OB1_RECV_REQUEST_INIT(&recvreq, NULL, 0, &ompi_mpi_char, src, tag, comm, true);
+    MCA_PML_OB1_RECV_REQUEST_INIT(&recvreq, NULL, 0, &ompi_mpi_char.dt, src, tag, comm, true);
     MCA_PML_OB1_RECV_REQUEST_START(&recvreq);
 
     ompi_request_wait_completion(&recvreq.req_recv.req_base.req_ompi);
diff --git a/ompi/mpi/c/accumulate.c b/ompi/mpi/c/accumulate.c
index c13f53e8d5..6ffa8a8a40 100644
--- a/ompi/mpi/c/accumulate.c
+++ b/ompi/mpi/c/accumulate.c
@@ -9,6 +9,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
+ * Copyright (c) 2009      Sun Microsystmes, Inc.  All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -17,7 +18,6 @@
  */
 #include "ompi_config.h"
 #include <stdio.h>
-
 #include "ompi/mpi/c/bindings.h"
 #include "ompi/win/win.h"
 #include "ompi/mca/osc/osc.h"
@@ -81,7 +81,7 @@ int MPI_Accumulate(void *origin_addr, int origin_count, MPI_Datatype origin_data
                    for other reduction operators, we don't require such
                    behaivor, as checking for it is expensive here and we don't
                    care in implementation.. */
-                if (op != &ompi_mpi_op_replace) {
+                if (op != &ompi_mpi_op_replace.op) {
                     ompi_datatype_t *op_check_dt, *origin_check_dt;
                     char *msg;
 
@@ -169,7 +169,7 @@ int MPI_Accumulate(void *origin_addr, int origin_count, MPI_Datatype origin_data
            for other reduction operators, we don't require such
            behaivor, as checking for it is expensive here and we don't
            care in implementation.. */
-        if (op != &ompi_mpi_op_replace) {
+        if (op != &ompi_mpi_op_replace.op) {
             ompi_datatype_t *op_check_dt;
             char *msg;
 
diff --git a/ompi/mpi/c/type_create_darray.c b/ompi/mpi/c/type_create_darray.c
index 506634ee5c..22f5e77a22 100644
--- a/ompi/mpi/c/type_create_darray.c
+++ b/ompi/mpi/c/type_create_darray.c
@@ -11,6 +11,7 @@
  *                         All rights reserved.
  * Copyright (c) 2007      Los Alamos National Security, LLC.  All rights
  *                         reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc. All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -108,7 +109,7 @@ int MPI_Type_create_darray(int size,
         /* Don't just return MPI_DATATYPE_NULL as that can't be
            MPI_TYPE_FREE()ed, and that seems bad */
         *newtype = ompi_ddt_create(0);
-        ompi_ddt_add(*newtype, &ompi_mpi_datatype_null, 0, 0, 0);
+        ompi_ddt_add(*newtype, &ompi_mpi_datatype_null.dt, 0, 0, 0);
         OPAL_CR_EXIT_LIBRARY();
         return MPI_SUCCESS;
     }
diff --git a/ompi/mpi/c/type_create_f90_complex.c b/ompi/mpi/c/type_create_f90_complex.c
index 3093675bc9..9f7a5c6bcb 100644
--- a/ompi/mpi/c/type_create_f90_complex.c
+++ b/ompi/mpi/c/type_create_f90_complex.c
@@ -9,7 +9,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
- * Copyright (c) 2006      Sun Microsystems, Inc.  All rights reserved.
+ * Copyright (c) 2006-2009 Sun Microsystems, Inc.  All rights reserved.
  * Copyright (c) 2008      Cisco Systems, Inc.  All rights reserved.
  * $COPYRIGHT$
  * 
@@ -69,12 +69,12 @@ int MPI_Type_create_f90_complex(int p, int r, MPI_Datatype *newtype)
      * cache.
      */
 
-    if( (LDBL_DIG < p) || (LDBL_MAX_10_EXP < r) )    *newtype = &ompi_mpi_datatype_null;
-    else if( (DBL_DIG < p) || (DBL_MAX_10_EXP < r) ) *newtype = &ompi_mpi_ldblcplex;
-    else if( (FLT_DIG < p) || (FLT_MAX_10_EXP < r) ) *newtype = &ompi_mpi_dblcplex;
-    else                                             *newtype = &ompi_mpi_cplex;
+    if( (LDBL_DIG < p) || (LDBL_MAX_10_EXP < r) )    *newtype = &ompi_mpi_datatype_null.dt;
+    else if( (DBL_DIG < p) || (DBL_MAX_10_EXP < r) ) *newtype = &ompi_mpi_ldblcplex.dt;
+    else if( (FLT_DIG < p) || (FLT_MAX_10_EXP < r) ) *newtype = &ompi_mpi_dblcplex.dt;
+    else                                             *newtype = &ompi_mpi_cplex.dt;
 
-    if( *newtype != &ompi_mpi_datatype_null ) {
+    if( *newtype != &ompi_mpi_datatype_null.dt ) {
         ompi_datatype_t* datatype;
         int* a_i[2];
         int rc;
diff --git a/ompi/mpi/c/type_create_f90_integer.c b/ompi/mpi/c/type_create_f90_integer.c
index 080b2b8e43..9097ac4daf 100644
--- a/ompi/mpi/c/type_create_f90_integer.c
+++ b/ompi/mpi/c/type_create_f90_integer.c
@@ -9,7 +9,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
- * Copyright (c) 2006      Sun Microsystems, Inc.  All rights reserved.
+ * Copyright (c) 2006-2009 Sun Microsystems, Inc.  All rights reserved.
  * Copyright (c) 2008      Cisco Systems, Inc.  All rights reserved.
  * $COPYRIGHT$
  * 
@@ -56,26 +56,26 @@ int MPI_Type_create_f90_integer(int r, MPI_Datatype *newtype)
      * cache.
      */
 
-    if      (r > 38) *newtype = &ompi_mpi_datatype_null;
+    if      (r > 38) *newtype = &ompi_mpi_datatype_null.dt;
 #if OMPI_HAVE_F90_INTEGER16
-    else if (r > 18) *newtype = &ompi_mpi_long_long_int;
+    else if (r > 18) *newtype = &ompi_mpi_long_long_int.dt;
 #else
-    else if (r > 18) *newtype = &ompi_mpi_datatype_null;
+    else if (r > 18) *newtype = &ompi_mpi_datatype_null.dt;
 #endif  /* OMPI_HAVE_F90_INTEGER16 */
 #if SIZEOF_LONG > SIZEOF_INT
-    else if (r >  9) *newtype = &ompi_mpi_long;
+    else if (r >  9) *newtype = &ompi_mpi_long.dt;
 #else
 #if SIZEOF_LONG_LONG > SIZEOF_INT
-    else if (r >  9) *newtype = &ompi_mpi_long_long_int;
+    else if (r >  9) *newtype = &ompi_mpi_long_long_int.dt;
 #else
-    else if (r >  9) *newtype = &ompi_mpi_datatype_null;
+    else if (r >  9) *newtype = &ompi_mpi_datatype_null.dt;
 #endif  /* SIZEOF_LONG_LONG > SIZEOF_INT */
 #endif  /* SIZEOF_LONG > SIZEOF_INT */
-    else if (r >  4) *newtype = &ompi_mpi_int;
-    else if (r >  2) *newtype = &ompi_mpi_short;
-    else             *newtype = &ompi_mpi_byte;
+    else if (r >  4) *newtype = &ompi_mpi_int.dt;
+    else if (r >  2) *newtype = &ompi_mpi_short.dt;
+    else             *newtype = &ompi_mpi_byte.dt;
 
-    if( *newtype != &ompi_mpi_datatype_null ) {
+    if( *newtype != &ompi_mpi_datatype_null.dt ) {
         ompi_datatype_t* datatype;
         int* a_i[1];
         int rc;
diff --git a/ompi/mpi/c/type_create_f90_real.c b/ompi/mpi/c/type_create_f90_real.c
index 86e774500d..3252b16063 100644
--- a/ompi/mpi/c/type_create_f90_real.c
+++ b/ompi/mpi/c/type_create_f90_real.c
@@ -9,7 +9,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
- * Copyright (c) 2006      Sun Microsystems, Inc.  All rights reserved.
+ * Copyright (c) 2006-2009 Sun Microsystems, Inc.  All rights reserved.
  * Copyright (c) 2008      Cisco Systems, Inc.  All rights reserved.
  * $COPYRIGHT$
  * 
@@ -70,12 +70,12 @@ int MPI_Type_create_f90_real(int p, int r, MPI_Datatype *newtype)
      * cache.
      */
 
-    if( (LDBL_DIG < p) || (LDBL_MAX_10_EXP < r) )    *newtype = &ompi_mpi_datatype_null;
-    else if( (DBL_DIG < p) || (DBL_MAX_10_EXP < r) ) *newtype = &ompi_mpi_long_double;
-    else if( (FLT_DIG < p) || (FLT_MAX_10_EXP < r) ) *newtype = &ompi_mpi_double;
-    else                                             *newtype = &ompi_mpi_float;
+    if( (LDBL_DIG < p) || (LDBL_MAX_10_EXP < r) )    *newtype = &ompi_mpi_datatype_null.dt;
+    else if( (DBL_DIG < p) || (DBL_MAX_10_EXP < r) ) *newtype = &ompi_mpi_long_double.dt;
+    else if( (FLT_DIG < p) || (FLT_MAX_10_EXP < r) ) *newtype = &ompi_mpi_double.dt;
+    else                                             *newtype = &ompi_mpi_float.dt;
 
-    if( *newtype != &ompi_mpi_datatype_null ) {
+    if( *newtype != &ompi_mpi_datatype_null.dt ) {
         ompi_datatype_t* datatype;
         int* a_i[2];
         int rc;
diff --git a/ompi/mpi/c/type_create_subarray.c b/ompi/mpi/c/type_create_subarray.c
index c297019348..3bb3a093c1 100644
--- a/ompi/mpi/c/type_create_subarray.c
+++ b/ompi/mpi/c/type_create_subarray.c
@@ -9,6 +9,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc. All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -77,7 +78,7 @@ int MPI_Type_create_subarray(int ndims,
     /* If the ndims is zero then return the NULL datatype */
     if( ndims < 2 ) {
         if( 0 == ndims ) {
-            *newtype = &ompi_mpi_datatype_null;
+            *newtype = &ompi_mpi_datatype_null.dt;
             OPAL_CR_EXIT_LIBRARY();
             return MPI_SUCCESS;
         }
diff --git a/ompi/mpi/c/type_match_size.c b/ompi/mpi/c/type_match_size.c
index 72db3a179d..72db821e6d 100644
--- a/ompi/mpi/c/type_match_size.c
+++ b/ompi/mpi/c/type_match_size.c
@@ -9,6 +9,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc. All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -51,11 +52,11 @@ int MPI_Type_match_size(int typeclass, int size, MPI_Datatype *type)
         *type = (MPI_Datatype)ompi_ddt_match_size( size, DT_FLAG_DATA_COMPLEX, DT_FLAG_DATA_FORTRAN );
         break;
     default:
-        *type = &ompi_mpi_datatype_null;
+        *type = &ompi_mpi_datatype_null.dt;
     }
 
     OPAL_CR_EXIT_LIBRARY();
-    if( *type != &ompi_mpi_datatype_null ) {
+    if( *type != &ompi_mpi_datatype_null.dt ) {
         return MPI_SUCCESS;
     }
 
diff --git a/ompi/mpi/cxx/intercepts.cc b/ompi/mpi/cxx/intercepts.cc
index b497ff6fc2..fde907d9a8 100644
--- a/ompi/mpi/cxx/intercepts.cc
+++ b/ompi/mpi/cxx/intercepts.cc
@@ -11,6 +11,7 @@
 // Copyright (c) 2004-2005 The Regents of the University of California.
 //                         All rights reserved.
 // Copyright (c) 2006-2008 Cisco Systems, Inc.  All rights reserved.
+// Copyright (c) 2009      Sun Microsystems, Inc.  All rights reserved.
 // $COPYRIGHT$
 // 
 // Additional copyrights may follow
@@ -78,13 +79,13 @@ void ompi_mpi_cxx_win_throw_excptn_fctn(MPI_Win *, int *errcode, ...)
 void
 MPI::InitializeIntercepts()
 {
-    ompi_mpi_errors_throw_exceptions.eh_comm_fn = 
+    ompi_mpi_errors_throw_exceptions.eh.eh_comm_fn = 
         ompi_mpi_cxx_comm_throw_excptn_fctn;
 #if OMPI_PROVIDE_MPI_FILE_INTERFACE
-    ompi_mpi_errors_throw_exceptions.eh_file_fn = 
+    ompi_mpi_errors_throw_exceptions.eh.eh_file_fn = 
         ompi_mpi_cxx_file_throw_excptn_fctn;
 #endif
-    ompi_mpi_errors_throw_exceptions.eh_win_fn = 
+    ompi_mpi_errors_throw_exceptions.eh.eh_win_fn = 
         ompi_mpi_cxx_win_throw_excptn_fctn;
 }
 
diff --git a/ompi/mpi/cxx/mpicxx.cc b/ompi/mpi/cxx/mpicxx.cc
index 2c87c78986..e5428e35ba 100644
--- a/ompi/mpi/cxx/mpicxx.cc
+++ b/ompi/mpi/cxx/mpicxx.cc
@@ -46,9 +46,9 @@ void* const BOTTOM = (void*) MPI_BOTTOM;
 void* const IN_PLACE = (void*) MPI_IN_PLACE;
 
 // error-handling specifiers
-const Errhandler  ERRORS_ARE_FATAL(&ompi_mpi_errors_are_fatal);
-const Errhandler  ERRORS_RETURN(&ompi_mpi_errors_return);
-const Errhandler  ERRORS_THROW_EXCEPTIONS(&ompi_mpi_errors_throw_exceptions);
+const Errhandler  ERRORS_ARE_FATAL((MPI_Errhandler)&(ompi_mpi_errors_are_fatal));
+const Errhandler  ERRORS_RETURN((MPI_Errhandler)&(ompi_mpi_errors_return));
+const Errhandler  ERRORS_THROW_EXCEPTIONS((MPI_Errhandler)&(ompi_mpi_errors_throw_exceptions));
 
 // elementary datatypes
 const Datatype CHAR(MPI_CHAR);
@@ -77,25 +77,25 @@ const Datatype LONG_DOUBLE_INT(MPI_LONG_DOUBLE);
 
 #if OMPI_WANT_F77_BINDINGS
 // elementary datatype (Fortran)
-const Datatype REAL(&ompi_mpi_real);
-const Datatype INTEGER(&ompi_mpi_integer);
-const Datatype DOUBLE_PRECISION(&ompi_mpi_dblprec);
-const Datatype F_COMPLEX(&ompi_mpi_cplex);
-const Datatype LOGICAL(&ompi_mpi_logic);
-const Datatype CHARACTER(&ompi_mpi_character);
+const Datatype REAL((MPI_Datatype)&(ompi_mpi_real));
+const Datatype INTEGER((MPI_Datatype)&(ompi_mpi_integer));
+const Datatype DOUBLE_PRECISION((MPI_Datatype)&(ompi_mpi_dblprec));
+const Datatype F_COMPLEX((MPI_Datatype)&(ompi_mpi_cplex));
+const Datatype LOGICAL((MPI_Datatype)&(ompi_mpi_logic));
+const Datatype CHARACTER((MPI_Datatype)&(ompi_mpi_character));
 
 // datatype for reduction functions (Fortran)
-const Datatype TWOREAL(&ompi_mpi_2real);
-const Datatype TWODOUBLE_PRECISION(&ompi_mpi_2dblprec);
-const Datatype TWOINTEGER(&ompi_mpi_2integer);
+const Datatype TWOREAL((MPI_Datatype)&(ompi_mpi_2real));
+const Datatype TWODOUBLE_PRECISION((MPI_Datatype)&(ompi_mpi_2dblprec));
+const Datatype TWOINTEGER((MPI_Datatype)&(ompi_mpi_2integer));
 
 // optional datatypes (Fortran)
-const Datatype INTEGER2(&ompi_mpi_integer);
-const Datatype REAL2(&ompi_mpi_real);
-const Datatype INTEGER1(&ompi_mpi_char);
-const Datatype INTEGER4(&ompi_mpi_short);
-const Datatype REAL4(&ompi_mpi_real);
-const Datatype REAL8(&ompi_mpi_double);
+const Datatype INTEGER2((MPI_Datatype)&(ompi_mpi_integer));
+const Datatype REAL2((MPI_Datatype)&(ompi_mpi_real));
+const Datatype INTEGER1((MPI_Datatype)&(ompi_mpi_char));
+const Datatype INTEGER4((MPI_Datatype)&(ompi_mpi_short));
+const Datatype REAL4((MPI_Datatype)&(ompi_mpi_real));
+const Datatype REAL8((MPI_Datatype)&(ompi_mpi_double));
 
 #endif // OMPI_WANT_f77_BINDINGS
 
@@ -104,10 +104,10 @@ const Datatype UNSIGNED_LONG_LONG(MPI_UNSIGNED_LONG_LONG);
 const Datatype LONG_LONG(MPI_LONG_LONG);
 
 // c++ types
-const Datatype BOOL(&ompi_mpi_cxx_bool);
-const Datatype COMPLEX(&ompi_mpi_cxx_cplex);
-const Datatype DOUBLE_COMPLEX(&ompi_mpi_cxx_dblcplex);
-const Datatype LONG_DOUBLE_COMPLEX(&ompi_mpi_cxx_ldblcplex);
+const Datatype BOOL((MPI_Datatype)&(ompi_mpi_cxx_bool));
+const Datatype COMPLEX((MPI_Datatype)&(ompi_mpi_cxx_cplex));
+const Datatype DOUBLE_COMPLEX((MPI_Datatype)&(ompi_mpi_cxx_dblcplex));
+const Datatype LONG_DOUBLE_COMPLEX((MPI_Datatype)&(ompi_mpi_cxx_ldblcplex));
 
 // reserved communicators
 Intracomm COMM_WORLD(MPI_COMM_WORLD);
diff --git a/ompi/mpi/f77/type_match_size_f.c b/ompi/mpi/f77/type_match_size_f.c
index 5d8c9f09a5..1200f7c5fa 100644
--- a/ompi/mpi/f77/type_match_size_f.c
+++ b/ompi/mpi/f77/type_match_size_f.c
@@ -9,6 +9,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc. All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -87,10 +88,10 @@ void mpi_type_match_size_f(MPI_Fint *typeclass, MPI_Fint *size, MPI_Fint *type,
         c_type = (MPI_Datatype)ompi_ddt_match_size( c_size, DT_FLAG_DATA_COMPLEX, DT_FLAG_DATA_FORTRAN );
         break;
     default:
-        c_type = &ompi_mpi_datatype_null;
+        c_type = &ompi_mpi_datatype_null.dt;
     }
     *type = MPI_Type_c2f( c_type );
-    if ( c_type != &ompi_mpi_datatype_null ) {
+    if ( c_type != &ompi_mpi_datatype_null.dt ) {
         *ierr = OMPI_INT_2_FINT( MPI_SUCCESS );
     } else {
         *ierr = OMPI_INT_2_FINT( MPI_ERR_ARG );
diff --git a/ompi/op/op.c b/ompi/op/op.c
index 83be1631f9..093c157da9 100644
--- a/ompi/op/op.c
+++ b/ompi/op/op.c
@@ -11,6 +11,7 @@
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
  * Copyright (c) 2007-2009 Cisco Systems, Inc.  All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc.  All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -57,20 +58,20 @@ OBJ_CLASS_INSTANCE(ompi_op_t, opal_object_t,
 /*
  * Intrinsic MPI_Op objects
  */
-ompi_op_t ompi_mpi_op_null;
-ompi_op_t ompi_mpi_op_max;
-ompi_op_t ompi_mpi_op_min;
-ompi_op_t ompi_mpi_op_sum;
-ompi_op_t ompi_mpi_op_prod;
-ompi_op_t ompi_mpi_op_land;
-ompi_op_t ompi_mpi_op_band;
-ompi_op_t ompi_mpi_op_lor;
-ompi_op_t ompi_mpi_op_bor;
-ompi_op_t ompi_mpi_op_lxor;
-ompi_op_t ompi_mpi_op_bxor;
-ompi_op_t ompi_mpi_op_maxloc;
-ompi_op_t ompi_mpi_op_minloc;
-ompi_op_t ompi_mpi_op_replace;
+ompi_predefined_op_t ompi_mpi_op_null;
+ompi_predefined_op_t ompi_mpi_op_max;
+ompi_predefined_op_t ompi_mpi_op_min;
+ompi_predefined_op_t ompi_mpi_op_sum;
+ompi_predefined_op_t ompi_mpi_op_prod;
+ompi_predefined_op_t ompi_mpi_op_land;
+ompi_predefined_op_t ompi_mpi_op_band;
+ompi_predefined_op_t ompi_mpi_op_lor;
+ompi_predefined_op_t ompi_mpi_op_bor;
+ompi_predefined_op_t ompi_mpi_op_lxor;
+ompi_predefined_op_t ompi_mpi_op_bxor;
+ompi_predefined_op_t ompi_mpi_op_maxloc;
+ompi_predefined_op_t ompi_mpi_op_minloc;
+ompi_predefined_op_t ompi_mpi_op_replace;
 
 /*
  * Map from ddt->id to position in op function pointer array
@@ -139,46 +140,46 @@ int ompi_op_init(void)
     /* Create the intrinsic ops */
 
     if (OMPI_SUCCESS != 
-        add_intrinsic(&ompi_mpi_op_null, OMPI_OP_BASE_FORTRAN_NULL,
+        add_intrinsic(&ompi_mpi_op_null.op, OMPI_OP_BASE_FORTRAN_NULL,
                       FLAGS, "MPI_OP_NULL") ||
         OMPI_SUCCESS != 
-        add_intrinsic(&ompi_mpi_op_max, OMPI_OP_BASE_FORTRAN_MAX,
+        add_intrinsic(&ompi_mpi_op_max.op, OMPI_OP_BASE_FORTRAN_MAX,
                       FLAGS, "MPI_OP_MAX") ||
         OMPI_SUCCESS != 
-        add_intrinsic(&ompi_mpi_op_min, OMPI_OP_BASE_FORTRAN_MIN,
+        add_intrinsic(&ompi_mpi_op_min.op, OMPI_OP_BASE_FORTRAN_MIN,
                       FLAGS, "MPI_OP_MIN") ||
         OMPI_SUCCESS != 
-        add_intrinsic(&ompi_mpi_op_sum, OMPI_OP_BASE_FORTRAN_SUM,
+        add_intrinsic(&ompi_mpi_op_sum.op, OMPI_OP_BASE_FORTRAN_SUM,
                       FLAGS_NO_FLOAT, "MPI_OP_SUM") ||
         OMPI_SUCCESS != 
-        add_intrinsic(&ompi_mpi_op_prod, OMPI_OP_BASE_FORTRAN_PROD,
+        add_intrinsic(&ompi_mpi_op_prod.op, OMPI_OP_BASE_FORTRAN_PROD,
                       FLAGS_NO_FLOAT, "MPI_OP_PROD") ||
         OMPI_SUCCESS != 
-        add_intrinsic(&ompi_mpi_op_land, OMPI_OP_BASE_FORTRAN_LAND,
+        add_intrinsic(&ompi_mpi_op_land.op, OMPI_OP_BASE_FORTRAN_LAND,
                       FLAGS, "MPI_OP_LAND") ||
         OMPI_SUCCESS != 
-        add_intrinsic(&ompi_mpi_op_band, OMPI_OP_BASE_FORTRAN_BAND,
+        add_intrinsic(&ompi_mpi_op_band.op, OMPI_OP_BASE_FORTRAN_BAND,
                       FLAGS, "MPI_OP_BAND") ||
         OMPI_SUCCESS != 
-        add_intrinsic(&ompi_mpi_op_lor, OMPI_OP_BASE_FORTRAN_LOR,
+        add_intrinsic(&ompi_mpi_op_lor.op, OMPI_OP_BASE_FORTRAN_LOR,
                       FLAGS, "MPI_OP_LOR") ||
         OMPI_SUCCESS != 
-        add_intrinsic(&ompi_mpi_op_bor, OMPI_OP_BASE_FORTRAN_BOR,
+        add_intrinsic(&ompi_mpi_op_bor.op, OMPI_OP_BASE_FORTRAN_BOR,
                       FLAGS, "MPI_OP_BOR") ||
         OMPI_SUCCESS != 
-        add_intrinsic(&ompi_mpi_op_lxor, OMPI_OP_BASE_FORTRAN_LXOR,
+        add_intrinsic(&ompi_mpi_op_lxor.op, OMPI_OP_BASE_FORTRAN_LXOR,
                       FLAGS, "MPI_OP_LXOR") ||
         OMPI_SUCCESS != 
-        add_intrinsic(&ompi_mpi_op_bxor, OMPI_OP_BASE_FORTRAN_BXOR,
+        add_intrinsic(&ompi_mpi_op_bxor.op, OMPI_OP_BASE_FORTRAN_BXOR,
                       FLAGS, "MPI_OP_BXOR") ||
         OMPI_SUCCESS != 
-        add_intrinsic(&ompi_mpi_op_maxloc, OMPI_OP_BASE_FORTRAN_MAXLOC,
+        add_intrinsic(&ompi_mpi_op_maxloc.op, OMPI_OP_BASE_FORTRAN_MAXLOC,
                       FLAGS, "MPI_OP_MAXLOC") ||
         OMPI_SUCCESS != 
-        add_intrinsic(&ompi_mpi_op_minloc, OMPI_OP_BASE_FORTRAN_MINLOC,
+        add_intrinsic(&ompi_mpi_op_minloc.op, OMPI_OP_BASE_FORTRAN_MINLOC,
                       FLAGS, "MPI_OP_MINLOC") ||
         OMPI_SUCCESS != 
-        add_intrinsic(&ompi_mpi_op_replace, OMPI_OP_BASE_FORTRAN_REPLACE,
+        add_intrinsic(&ompi_mpi_op_replace.op, OMPI_OP_BASE_FORTRAN_REPLACE,
                       FLAGS, "MPI_OP_REPLACE")) {
         return OMPI_ERROR;
     }
diff --git a/ompi/op/op.h b/ompi/op/op.h
index db069caad9..d42986b610 100644
--- a/ompi/op/op.h
+++ b/ompi/op/op.h
@@ -12,6 +12,7 @@
  *                         All rights reserved.
  * Copyright (c) 2008      UT-Battelle, LLC
  * Copyright (c) 2008-2009 Cisco Systems, Inc.  All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc.  All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -145,6 +146,20 @@ struct ompi_op_t {
 typedef struct ompi_op_t ompi_op_t;
 OMPI_DECLSPEC OBJ_CLASS_DECLARATION(ompi_op_t);
 
+/**
+ * Padded struct to maintain back compatibiltiy.
+ * See ompi/communicator/communicator.h comments with struct ompi_communicator_t
+ * for full explanation why we chose the following padding construct for predefines.
+ */
+#define PREDEFINED_OP_PAD (sizeof(void*) * 256)
+
+struct ompi_predefined_op_t {
+    struct ompi_op_t op;
+    char padding[PREDEFINED_OP_PAD - sizeof(ompi_op_t)];
+};
+
+typedef struct ompi_predefined_op_t ompi_predefined_op_t;
+
 /**
  * Array to map ddt->id values to the corresponding position in the op
  * function array.
@@ -179,72 +194,72 @@ OMPI_DECLSPEC extern int ompi_op_ddt_map[DT_MAX_PREDEFINED];
 /**
  * Global variable for MPI_OP_NULL
  */
-OMPI_DECLSPEC extern ompi_op_t ompi_mpi_op_null;
+OMPI_DECLSPEC extern ompi_predefined_op_t ompi_mpi_op_null;
 
 /**
  * Global variable for MPI_MAX
  */
-OMPI_DECLSPEC extern ompi_op_t ompi_mpi_op_max;
+OMPI_DECLSPEC extern ompi_predefined_op_t ompi_mpi_op_max;
 
 /**
  * Global variable for MPI_MIN
  */
-OMPI_DECLSPEC extern ompi_op_t ompi_mpi_op_min;
+OMPI_DECLSPEC extern ompi_predefined_op_t ompi_mpi_op_min;
 
 /**
  * Global variable for MPI_SUM
  */
-OMPI_DECLSPEC extern ompi_op_t ompi_mpi_op_sum;
+OMPI_DECLSPEC extern ompi_predefined_op_t ompi_mpi_op_sum;
 
 /**
  * Global variable for MPI_PROD
  */
-OMPI_DECLSPEC extern ompi_op_t ompi_mpi_op_prod;
+OMPI_DECLSPEC extern ompi_predefined_op_t ompi_mpi_op_prod;
 
 /**
  * Global variable for MPI_LAND
  */
-OMPI_DECLSPEC extern ompi_op_t ompi_mpi_op_land;
+OMPI_DECLSPEC extern ompi_predefined_op_t ompi_mpi_op_land;
 
 /**
  * Global variable for MPI_BAND
  */
-OMPI_DECLSPEC extern ompi_op_t ompi_mpi_op_band;
+OMPI_DECLSPEC extern ompi_predefined_op_t ompi_mpi_op_band;
 
 /**
  * Global variable for MPI_LOR
  */
-OMPI_DECLSPEC extern ompi_op_t ompi_mpi_op_lor;
+OMPI_DECLSPEC extern ompi_predefined_op_t ompi_mpi_op_lor;
 
 /**
  * Global variable for MPI_BOR
  */
-OMPI_DECLSPEC extern ompi_op_t ompi_mpi_op_bor;
+OMPI_DECLSPEC extern ompi_predefined_op_t ompi_mpi_op_bor;
 
 /**
  * Global variable for MPI_LXOR
  */
-OMPI_DECLSPEC extern ompi_op_t ompi_mpi_op_lxor;
+OMPI_DECLSPEC extern ompi_predefined_op_t ompi_mpi_op_lxor;
 
 /**
  * Global variable for MPI_BXOR
  */
-OMPI_DECLSPEC extern ompi_op_t ompi_mpi_op_bxor;
+OMPI_DECLSPEC extern ompi_predefined_op_t ompi_mpi_op_bxor;
 
 /**
  * Global variable for MPI_MAXLOC
  */
-OMPI_DECLSPEC extern ompi_op_t ompi_mpi_op_maxloc;
+OMPI_DECLSPEC extern ompi_predefined_op_t ompi_mpi_op_maxloc;
 
 /**
  * Global variable for MPI_MINLOC
  */
-OMPI_DECLSPEC extern ompi_op_t ompi_mpi_op_minloc;
+OMPI_DECLSPEC extern ompi_predefined_op_t ompi_mpi_op_minloc;
 
 /**
  * Global variable for MPI_REPLACE
  */
-OMPI_DECLSPEC extern ompi_op_t ompi_mpi_op_replace;
+OMPI_DECLSPEC extern ompi_predefined_op_t ompi_mpi_op_replace;
 
 
 /**
diff --git a/ompi/request/grequest.c b/ompi/request/grequest.c
index 7bd237f650..78d1bf7cd7 100644
--- a/ompi/request/grequest.c
+++ b/ompi/request/grequest.c
@@ -10,6 +10,7 @@
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
  * Copyright (c) 2006      Cisco Systems, Inc.  All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc.  All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -18,6 +19,7 @@
  */
 
 #include "ompi_config.h"
+#include "ompi/communicator/communicator.h"
 #include "ompi/request/grequest.h"
 #include "ompi/mpi/f77/fint_2_int.h"
 
@@ -64,7 +66,7 @@ static void ompi_grequest_construct(ompi_grequest_t* greq)
     greq->greq_base.req_free     = ompi_grequest_free;
     greq->greq_base.req_cancel   = ompi_grequest_cancel;
     greq->greq_base.req_type = OMPI_REQUEST_GEN;
-    greq->greq_base.req_mpi_object.comm = &ompi_mpi_comm_world;
+    greq->greq_base.req_mpi_object.comm = &(ompi_mpi_comm_world.comm);
     /* Set the function pointers to C here; the F77 MPI API will
        override this value if the gen request was created from
        Fortran */
diff --git a/ompi/request/request.c b/ompi/request/request.c
index 50cdac3248..7d5ef32c5c 100644
--- a/ompi/request/request.c
+++ b/ompi/request/request.c
@@ -11,6 +11,7 @@
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
  * Copyright (c) 2006      Cisco Systems, Inc.  All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc.  All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -20,6 +21,7 @@
 
 #include "ompi_config.h"
 
+#include "ompi/communicator/communicator.h"
 #include "opal/class/opal_object.h"
 #include "ompi/request/request.h"
 #include "ompi/request/request_default.h"
@@ -30,7 +32,7 @@ size_t                           ompi_request_waiting = 0;
 size_t                           ompi_request_completed = 0;
 opal_mutex_t                     ompi_request_lock;
 opal_condition_t                 ompi_request_cond;
-ompi_request_t                   ompi_request_null;
+ompi_predefined_request_t        ompi_request_null;
 ompi_request_t                   ompi_request_empty;
 ompi_status_public_t             ompi_status_empty;
 ompi_request_fns_t               ompi_request_functions = {
@@ -72,7 +74,7 @@ static int ompi_request_null_cancel(ompi_request_t* request, int flag)
 
 static int ompi_request_empty_free(ompi_request_t** request)
 {
-    *request = &ompi_request_null;
+    *request = &ompi_request_null.request;
     return OMPI_SUCCESS;
 }
 
@@ -81,7 +83,7 @@ int ompi_request_persistent_proc_null_free(ompi_request_t** request)
     OMPI_REQUEST_FINI(*request);
     (*request)->req_state = OMPI_REQUEST_INVALID;
     OBJ_RELEASE(*request);
-    *request = &ompi_request_null;
+    *request = &ompi_request_null.request;
     return OMPI_SUCCESS;
 }
 
@@ -104,23 +106,23 @@ int ompi_request_init(void)
                                                 0, OMPI_FORTRAN_HANDLE_MAX, 64) ) {
         return OMPI_ERROR;
     }
-    ompi_request_null.req_type = OMPI_REQUEST_NULL;
-    ompi_request_null.req_status.MPI_SOURCE = MPI_PROC_NULL;
-    ompi_request_null.req_status.MPI_TAG = MPI_ANY_TAG;
-    ompi_request_null.req_status.MPI_ERROR = MPI_SUCCESS;
-    ompi_request_null.req_status._count = 0;
-    ompi_request_null.req_status._cancelled = 0;
+    ompi_request_null.request.req_type = OMPI_REQUEST_NULL;
+    ompi_request_null.request.req_status.MPI_SOURCE = MPI_PROC_NULL;
+    ompi_request_null.request.req_status.MPI_TAG = MPI_ANY_TAG;
+    ompi_request_null.request.req_status.MPI_ERROR = MPI_SUCCESS;
+    ompi_request_null.request.req_status._count = 0;
+    ompi_request_null.request.req_status._cancelled = 0;
 
-    ompi_request_null.req_complete = true;
-    ompi_request_null.req_state = OMPI_REQUEST_INACTIVE;
-    ompi_request_null.req_persistent = false;
-    ompi_request_null.req_f_to_c_index =
+    ompi_request_null.request.req_complete = true;
+    ompi_request_null.request.req_state = OMPI_REQUEST_INACTIVE;
+    ompi_request_null.request.req_persistent = false;
+    ompi_request_null.request.req_f_to_c_index =
         opal_pointer_array_add(&ompi_request_f_to_c_table, &ompi_request_null);
-    ompi_request_null.req_free = ompi_request_null_free;
-    ompi_request_null.req_cancel = ompi_request_null_cancel;
-    ompi_request_null.req_mpi_object.comm = &ompi_mpi_comm_world;
+    ompi_request_null.request.req_free = ompi_request_null_free;
+    ompi_request_null.request.req_cancel = ompi_request_null_cancel;
+    ompi_request_null.request.req_mpi_object.comm = &ompi_mpi_comm_world.comm;
 
-    if (0 != ompi_request_null.req_f_to_c_index) {
+    if (0 != ompi_request_null.request.req_f_to_c_index) {
         return OMPI_ERR_REQUEST;
     }
 
@@ -150,7 +152,7 @@ int ompi_request_init(void)
         opal_pointer_array_add(&ompi_request_f_to_c_table, &ompi_request_empty);
     ompi_request_empty.req_free = ompi_request_empty_free;
     ompi_request_empty.req_cancel = ompi_request_null_cancel;
-    ompi_request_empty.req_mpi_object.comm = &ompi_mpi_comm_world;
+    ompi_request_empty.req_mpi_object.comm = &ompi_mpi_comm_world.comm;
 
     if (1 != ompi_request_empty.req_f_to_c_index) {
         return OMPI_ERR_REQUEST;
@@ -168,8 +170,8 @@ int ompi_request_init(void)
 
 int ompi_request_finalize(void)
 {
-    OMPI_REQUEST_FINI( &ompi_request_null );
-    OBJ_DESTRUCT( &ompi_request_null );
+    OMPI_REQUEST_FINI( &ompi_request_null.request );
+    OBJ_DESTRUCT( &ompi_request_null.request );
     OMPI_REQUEST_FINI( &ompi_request_empty );
     OBJ_DESTRUCT( &ompi_request_empty );
     OBJ_DESTRUCT( &ompi_request_cond );
diff --git a/ompi/request/request.h b/ompi/request/request.h
index 4805118c9b..843c3a0c7d 100644
--- a/ompi/request/request.h
+++ b/ompi/request/request.h
@@ -11,6 +11,7 @@
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
  * Copyright (c) 2006      Cisco Systems, Inc.  All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc.  All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -131,6 +132,19 @@ struct ompi_request_t {
  */
 typedef struct ompi_request_t ompi_request_t;
 
+/**
+ * Padded struct to maintain back compatibiltiy.
+ * See ompi/communicator/communicator.h comments with struct ompi_communicator_t
+ * for full explanation why we chose the following padding construct for predefines.
+ */
+#define PREDEFINED_REQUEST_PAD (sizeof(void*) * 32)
+
+struct ompi_predefined_request_t {
+    struct ompi_request_t request;
+    char padding[PREDEFINED_REQUEST_PAD - sizeof(ompi_request_t)];
+};
+
+typedef struct ompi_predefined_request_t ompi_predefined_request_t;
 
 /**
  * Initialize a request.  This is a macro to avoid function call
@@ -312,7 +326,7 @@ OMPI_DECLSPEC extern size_t                ompi_request_completed;
 OMPI_DECLSPEC extern int32_t               ompi_request_poll;
 OMPI_DECLSPEC extern opal_mutex_t          ompi_request_lock;
 OMPI_DECLSPEC extern opal_condition_t      ompi_request_cond;
-OMPI_DECLSPEC extern ompi_request_t        ompi_request_null;
+OMPI_DECLSPEC extern ompi_predefined_request_t        ompi_request_null;
 OMPI_DECLSPEC extern ompi_request_t        ompi_request_empty;
 OMPI_DECLSPEC extern ompi_status_public_t  ompi_status_empty;
 OMPI_DECLSPEC extern ompi_request_fns_t    ompi_request_functions;
diff --git a/ompi/runtime/ompi_mpi_finalize.c b/ompi/runtime/ompi_mpi_finalize.c
index b637df6f6c..76f81f21d0 100644
--- a/ompi/runtime/ompi_mpi_finalize.c
+++ b/ompi/runtime/ompi_mpi_finalize.c
@@ -14,6 +14,7 @@
  * Copyright (c) 2006      Los Alamos National Security, LLC.  All rights
  *                         reserved. 
  * Copyright (c) 2006      University of Houston. All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc.  All rights reserved.
  *
  * $COPYRIGHT$
  * 
@@ -119,11 +120,11 @@ int ompi_mpi_finalize(void)
        anything else in MPI_FINALIZE (to include setting up such that
        MPI_FINALIZED will return true). */
 
-    if (NULL != ompi_mpi_comm_self.c_keyhash) {
+    if (NULL != ompi_mpi_comm_self.comm.c_keyhash) {
         ompi_attr_delete_all(COMM_ATTR, &ompi_mpi_comm_self,
-                             ompi_mpi_comm_self.c_keyhash);
-        OBJ_RELEASE(ompi_mpi_comm_self.c_keyhash);
-        ompi_mpi_comm_self.c_keyhash = NULL;
+                             ompi_mpi_comm_self.comm.c_keyhash);
+        OBJ_RELEASE(ompi_mpi_comm_self.comm.c_keyhash);
+        ompi_mpi_comm_self.comm.c_keyhash = NULL;
     }
 
     /* Proceed with MPI_FINALIZE */
diff --git a/ompi/runtime/ompi_mpi_init.c b/ompi/runtime/ompi_mpi_init.c
index f62f932b23..1d16d5a9a1 100644
--- a/ompi/runtime/ompi_mpi_init.c
+++ b/ompi/runtime/ompi_mpi_init.c
@@ -13,7 +13,7 @@
  * Copyright (c) 2006-2007 Los Alamos National Security, LLC.  All rights
  *                         reserved. 
  * Copyright (c) 2006      University of Houston. All rights reserved.
- * Copyright (c) 2008      Sun Microsystems, Inc.  All rights reserved.
+ * Copyright (c) 2008-2009 Sun Microsystems, Inc.  All rights reserved.
  *
  * $COPYRIGHT$
  * 
@@ -136,7 +136,7 @@ static void warn_fork_cb(void)
     if (ompi_mpi_initialized && !ompi_mpi_finalized && !fork_warning_issued) {
         orte_show_help("help-mpi-runtime.txt", "mpi_init:warn-fork", true,
                        orte_process_info.nodename, getpid(),
-                       ompi_mpi_comm_world.c_my_rank);
+                       ompi_mpi_comm_world.comm.c_my_rank);
         fork_warning_issued = true;
     }
 }
@@ -688,15 +688,15 @@ int ompi_mpi_init(int argc, char **argv, int requested, int *provided)
         goto error;
     }
 
-    MCA_PML_CALL(add_comm(&ompi_mpi_comm_world));
-    MCA_PML_CALL(add_comm(&ompi_mpi_comm_self));
+    MCA_PML_CALL(add_comm(&ompi_mpi_comm_world.comm));
+    MCA_PML_CALL(add_comm(&ompi_mpi_comm_self.comm));
 
 
     /*
      * Dump all MCA parameters if requested
      */
     if (ompi_mpi_show_mca_params) {
-       ompi_show_all_mca_params(ompi_mpi_comm_world.c_my_rank, 
+       ompi_show_all_mca_params(ompi_mpi_comm_world.comm.c_my_rank, 
                                 nprocs, 
                                 orte_process_info.nodename);
     }
diff --git a/ompi/win/win.c b/ompi/win/win.c
index 44bd208256..e0b266063f 100644
--- a/ompi/win/win.c
+++ b/ompi/win/win.c
@@ -10,6 +10,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc. All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -36,7 +37,7 @@
  */
 opal_pointer_array_t ompi_mpi_windows; 
 
-ompi_win_t ompi_mpi_win_null;
+ompi_predefined_win_t ompi_mpi_win_null;
 
 static void ompi_win_construct(ompi_win_t *win);
 static void ompi_win_destruct(ompi_win_t *win);
@@ -55,12 +56,12 @@ ompi_win_init(void)
     }
 
     /* Setup MPI_WIN_NULL */
-    OBJ_CONSTRUCT(&ompi_mpi_win_null, ompi_win_t);
-    ompi_mpi_win_null.w_flags = OMPI_WIN_INVALID;
-    ompi_mpi_win_null.w_group = &ompi_mpi_group_null;
+    OBJ_CONSTRUCT(&ompi_mpi_win_null.win, ompi_win_t);
+    ompi_mpi_win_null.win.w_flags = OMPI_WIN_INVALID;
+    ompi_mpi_win_null.win.w_group = &ompi_mpi_group_null.group;
     OBJ_RETAIN(&ompi_mpi_group_null);
-    ompi_win_set_name(&ompi_mpi_win_null, "MPI_WIN_NULL");
-    opal_pointer_array_set_item(&ompi_mpi_windows, 0, &ompi_mpi_win_null);
+    ompi_win_set_name(&ompi_mpi_win_null.win, "MPI_WIN_NULL");
+    opal_pointer_array_set_item(&ompi_mpi_windows, 0, &ompi_mpi_win_null.win);
 
     return OMPI_SUCCESS;
 }
@@ -69,7 +70,7 @@ ompi_win_init(void)
 int
 ompi_win_finalize(void)
 {
-    OBJ_DESTRUCT(&ompi_mpi_win_null);
+    OBJ_DESTRUCT(&ompi_mpi_win_null.win);
     OBJ_DESTRUCT(&ompi_mpi_windows);
 
     return OMPI_SUCCESS;
@@ -208,8 +209,8 @@ ompi_win_construct(ompi_win_t *win)
 
     /* every new window defaults to MPI_ERRORS_ARE_FATAL (MPI-2 6.6.1,
        pg. 137) */
-    OBJ_RETAIN(&ompi_mpi_errors_are_fatal);
-    win->error_handler = &ompi_mpi_errors_are_fatal;
+    OBJ_RETAIN(&ompi_mpi_errors_are_fatal.eh);
+    win->error_handler = &ompi_mpi_errors_are_fatal.eh;
     win->errhandler_type = OMPI_ERRHANDLER_TYPE_WIN;
 
     win->w_disp_unit = 0;
diff --git a/ompi/win/win.h b/ompi/win/win.h
index f312bf38aa..aea5d2ce65 100644
--- a/ompi/win/win.h
+++ b/ompi/win/win.h
@@ -11,6 +11,7 @@
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
  * Copyright (c) 2006      Cisco Systems, Inc.  All rights reserved.
+ * Copyright (c) 2009      Sun Microsystems, Inc.  All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -93,7 +94,20 @@ struct ompi_win_t {
 typedef struct ompi_win_t ompi_win_t;
 OMPI_DECLSPEC OBJ_CLASS_DECLARATION(ompi_win_t);
 
-OMPI_DECLSPEC extern ompi_win_t ompi_mpi_win_null;
+/**
+ * Padded struct to maintain back compatibiltiy.
+ * See ompi/communicator/communicator.h comments with struct ompi_communicator_t
+ * for full explanation why we chose the following padding construct for predefines.
+ */
+#define PREDEFINED_WIN_PAD (sizeof(void*) * 64)
+
+struct ompi_predefined_win_t {
+    struct ompi_win_t win;
+    char padding[PREDEFINED_WIN_PAD - sizeof(ompi_win_t)];
+};
+typedef struct ompi_predefined_win_t ompi_predefined_win_t;
+
+OMPI_DECLSPEC extern ompi_predefined_win_t ompi_mpi_win_null;
 
 int ompi_win_init(void);
 int ompi_win_finalize(void);
diff --git a/test/Makefile.am b/test/Makefile.am
index e76c9a5091..404e2491d8 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -9,6 +9,7 @@
 #                         University of Stuttgart.  All rights reserved.
 # Copyright (c) 2004-2005 The Regents of the University of California.
 #                         All rights reserved.
+# Copyright (c) 2009      Sun Microsystems, Inc. All rights reserved.
 # $COPYRIGHT$
 # 
 # Additional copyrights may follow
@@ -16,8 +17,9 @@
 # $HEADER$
 #
 
-
-
 # support needs to be first for dependencies
 SUBDIRS = support asm class threads peruse datatype
 DIST_SUBDIRS = event $(SUBDIRS)
+
+TESTS =
+include predefined/Makefile.inc
diff --git a/test/predefined/Makefile.inc b/test/predefined/Makefile.inc
new file mode 100644
index 0000000000..79191cb2c7
--- /dev/null
+++ b/test/predefined/Makefile.inc
@@ -0,0 +1,22 @@
+# -*- makefile -*-
+#
+# Copyright (c) 2009      Sun Microsystems, Inc. All rights reserved.
+# Copyright (c) 2009      Cisco Systems, Inc. All rights reserved.
+# $COPYRIGHT$
+# 
+# Additional copyrights may follow
+# 
+# $HEADER$
+#
+
+
+check_PROGRAMS = \
+	predefined/ompi_predefined
+
+predefined_ompi_predefined_SOURCES = predefined/ompi_predefined.c
+predefined_ompi_predefined_LDADD = \
+	$(top_builddir)/ompi/libmpi.la \
+	$(top_builddir)/orte/libopen-rte.la \
+	$(top_builddir)/opal/libopen-pal.la 
+predefined_ompi_predefined_DEPENDENCIES = $(ompi_predefined_LDADD)
+
diff --git a/test/predefined/ompi_predefined.c b/test/predefined/ompi_predefined.c
new file mode 100644
index 0000000000..1124819e67
--- /dev/null
+++ b/test/predefined/ompi_predefined.c
@@ -0,0 +1,161 @@
+/*   
+ * Copyright (c) 2009      Sun Microsystems, Inc  All rights reserved.
+ * Copyright (c) 2009      Cisco Systems, Inc  All rights reserved.
+ * $COPYRIGHT$
+ * 
+ * Additional copyrights may follow
+ * 
+ * $HEADER$
+ */
+
+#include "ompi_config.h"
+#include "ompi/communicator/communicator.h"
+#include "ompi/group/group.h"
+#include "ompi/request/request.h"
+#include "ompi/op/op.h"
+#include "ompi/datatype/datatype.h"
+#include "ompi/win/win.h"
+#include "ompi/info/info.h"
+#include "ompi/file/file.h"
+
+#include <stdlib.h>
+
+#define GAP_CHECK(NAME, BASE, F1, F2, CGAP) {      \
+   offset = (size_t)&BASE.F1 - (size_t)&BASE;       \
+   exp_offset = ((size_t)&BASE.F2 - (size_t)&BASE) + sizeof(BASE.F2);	\
+   printf(NAME" = %lu, %lu ", offset, sizeof(BASE.F1)); \
+   if (CGAP && offset != exp_offset) printf("***"); \
+   printf("\n"); \
+   }
+
+
+int main(int argc, char **argv) {
+    ompi_communicator_t test_comm;
+    ompi_group_t test_group;
+    ompi_request_t test_req;
+    ompi_op_t test_op;
+    ompi_win_t test_win;
+    ompi_info_t test_info;
+    ompi_file_t test_file;
+    size_t exp_offset, offset;
+
+    /* Test Predefined communicator sizes */
+    printf("ompi_predefined_communicator_t = %lu bytes\n", sizeof(ompi_predefined_communicator_t));
+    printf("ompi_communicator_t = %lu bytes\n", sizeof(ompi_communicator_t));
+    GAP_CHECK("c_base", test_comm, c_base, c_base, 0);
+    GAP_CHECK("c_lock", test_comm, c_lock, c_base, 1);
+    GAP_CHECK("c_name", test_comm, c_name, c_lock, 1);
+    GAP_CHECK("c_contextid", test_comm, c_contextid, c_name, 1);
+    GAP_CHECK("c_my_rank", test_comm, c_my_rank, c_contextid, 1);
+    GAP_CHECK("c_flags", test_comm, c_flags, c_my_rank, 1);
+    GAP_CHECK("c_id_available", test_comm, c_id_available, c_flags, 1);
+    GAP_CHECK("c_id_start_index", test_comm, c_id_start_index, c_id_available,  1);
+    GAP_CHECK("c_remote_group", test_comm, c_remote_group, c_local_group, 1);
+    GAP_CHECK("c_local_comm", test_comm, c_local_comm,  c_remote_group,  1);
+    GAP_CHECK("c_keyhash", test_comm, c_keyhash, c_local_comm,  1);
+    GAP_CHECK("c_cube_dim", test_comm, c_cube_dim, c_keyhash,  1);
+    GAP_CHECK("c_topo_component", test_comm, c_topo_component, c_cube_dim,  1);
+    GAP_CHECK("c_topo", test_comm, c_topo, c_topo_component,  1);
+    GAP_CHECK("c_topo_comm", test_comm, c_topo_comm, c_topo,  1);
+    GAP_CHECK("c_topo_module", test_comm, c_topo_module, c_topo_comm,  1);
+    GAP_CHECK("c_f_to_c_index", test_comm, c_f_to_c_index, c_topo_module, 1);
+#ifdef OMPI_WANT_PERUSE
+    GAP_CHECK("c_peruse_handles", test_comm, c_peruse_handles, c_f_to_c_index, 1);
+    GAP_CHECK("error_handler", test_comm, error_handler, c_peruse_handles, 1);
+#else
+    GAP_CHECK("error_handler", test_comm, error_handler, c_f_to_c_index, 1);
+#endif
+    GAP_CHECK("errhandler_type", test_comm, errhandler_type, error_handler, 1);
+    GAP_CHECK("c_pml_comm", test_comm, c_pml_comm, errhandler_type, 1);
+    GAP_CHECK("c_coll", test_comm, c_coll, c_pml_comm, 1);
+
+    /* Test Predefined group sizes */
+    printf("=============================================\n");
+    printf("ompi_predefined_group_t = %lu bytes\n", sizeof(ompi_predefined_group_t));
+    printf("ompi_group_t = %lu bytes\n", sizeof(ompi_group_t));
+    GAP_CHECK("grp_proc_count", test_group, grp_proc_count, grp_proc_count, 0);
+    GAP_CHECK("grp_my_rank", test_group, grp_my_rank, grp_proc_count, 1);
+    GAP_CHECK("grp_f_to_c_index", test_group, grp_f_to_c_index, grp_my_rank, 1);
+    GAP_CHECK("grp_proc_pointers", test_group, grp_proc_pointers, grp_f_to_c_index, 1);
+    GAP_CHECK("grp_flags", test_group, grp_flags, grp_proc_pointers, 1);
+    GAP_CHECK("grp_parent_group_ptr", test_group, grp_parent_group_ptr, grp_flags, 1);
+
+    /* Test Predefined request sizes */
+    printf("=============================================\n");
+    printf("ompi_predefined_request_t = %lu bytes\n", sizeof(ompi_predefined_request_t));
+    printf("ompi_request_t = %lu bytes\n", sizeof(ompi_request_t));
+    GAP_CHECK("super", test_req, super, super, 0);
+    GAP_CHECK("req_type", test_req, req_type, super, 1);
+    GAP_CHECK("req_status", test_req, req_status, req_type, 1);
+    GAP_CHECK("req_complete", test_req, req_complete, req_status, 1);
+    GAP_CHECK("req_state", test_req, req_state, req_complete, 1);
+    GAP_CHECK("req_persistent", test_req, req_persistent, req_state, 1);
+    GAP_CHECK("req_f_to_c_index", test_req, req_f_to_c_index, req_persistent, 1);
+    GAP_CHECK("req_free", test_req, req_free, req_f_to_c_index, 1);
+
+    /* Test Predefined op sizes */
+    printf("=============================================\n");
+    printf("ompi_predefined_op_t = %lu bytes\n", sizeof(ompi_predefined_op_t));
+    printf("ompi_op_t = %lu bytes\n", sizeof(ompi_op_t));
+    GAP_CHECK("super", test_op, super, super, 0)
+    GAP_CHECK("o_name", test_op, o_name, super, 1)
+    GAP_CHECK("o_flags", test_op, o_flags, o_name, 1)
+    GAP_CHECK("o_f_to_c_index", test_op, o_f_to_c_index, o_flags, 1)
+    GAP_CHECK("o_func", test_op, o_func, o_f_to_c_index, 1)
+    GAP_CHECK("o_3buff_instrinsic", test_op, o_3buff_intrinsic, o_func, 1)
+
+    /* Test Predefined datatype sizes */
+    printf("=============================================\n");
+    printf("ompi_predefined_datatype_t = %lu bytes\n", sizeof(ompi_predefined_datatype_t));
+    printf("ompi_datatype_t = %lu bytes\n", sizeof(ompi_datatype_t));
+
+    /* Test Predefined win sizes */
+    printf("=============================================\n");
+    printf("ompi_predefined_win_t = %lu bytes\n", sizeof(ompi_predefined_win_t));
+    printf("ompi_win_t = %lu bytes\n", sizeof(ompi_win_t));
+    GAP_CHECK("w_base", test_win, w_base, w_base, 0);
+    GAP_CHECK("w_lock", test_win, w_lock, w_base, 1);
+    GAP_CHECK("w_name", test_win, w_name, w_lock, 1);
+    GAP_CHECK("w_group", test_win, w_group, w_name, 1);
+    GAP_CHECK("w_flags", test_win, w_flags, w_group, 1);
+    GAP_CHECK("w_keyhash", test_win, w_keyhash, w_flags, 1);
+    GAP_CHECK("w_f_to_c_index", test_win, w_f_to_c_index, w_keyhash, 1);
+    GAP_CHECK("error_handler", test_win, error_handler, w_f_to_c_index, 1);
+    GAP_CHECK("errhandler_type", test_win, errhandler_type, error_handler, 1);
+    GAP_CHECK("w_disp_unit", test_win, w_disp_unit, errhandler_type, 1);
+    GAP_CHECK("w_baseptr", test_win, w_baseptr, w_disp_unit, 1);
+    GAP_CHECK("w_size", test_win, w_size, w_baseptr, 1);
+    GAP_CHECK("w_mode", test_win, w_mode, w_size, 1);
+    GAP_CHECK("w_osc_module", test_win, w_osc_module, w_size, 1);
+
+    /* Test Predefined info sizes */
+    printf("=============================================\n");
+    printf("ompi_predefined_info_t = %lu bytes\n", sizeof(ompi_predefined_info_t));
+    printf("ompi_info_t = %lu bytes\n", sizeof(ompi_info_t));
+    GAP_CHECK("super", test_info, super, super, 0);
+    GAP_CHECK("i_f_to_c_index", test_info, i_f_to_c_index, super, 1);
+    GAP_CHECK("i_lock", test_info, i_lock, i_f_to_c_index, 1);
+    GAP_CHECK("i_freed", test_info, i_freed, i_lock, 1);
+
+    /* Test Predefined file sizes */
+    printf("=============================================\n");
+    printf("ompi_predefined_file_t = %lu bytes\n", sizeof(ompi_predefined_file_t));
+    printf("ompi_file_t = %lu bytes\n", sizeof(ompi_file_t));
+    GAP_CHECK("super", test_file, super, super, 0);
+    GAP_CHECK("f_comm", test_file, f_comm, super, 1);
+    GAP_CHECK("f_filename", test_file, f_filename, f_comm, 1);
+    GAP_CHECK("f_amode", test_file, f_amode,  f_filename, 1);
+    GAP_CHECK("f_info", test_file, f_info, f_amode,  1);
+    GAP_CHECK("f_flags", test_file, f_flags, f_info,  1);
+    GAP_CHECK("f_f_to_c_index", test_file, f_f_to_c_index, f_flags, 1);
+    GAP_CHECK("error_handler", test_file, error_handler, f_f_to_c_index, 1);
+    GAP_CHECK("errhandler_type", test_file, errhandler_type, error_handler, 1);
+    GAP_CHECK("f_io_version", test_file, f_io_version, errhandler_type, 1);
+    GAP_CHECK("f_io_selected_component", test_file, f_io_selected_component, f_io_version, 1);
+    GAP_CHECK("f_io_selected_module", test_file, f_io_selected_module, f_io_selected_component, 1);
+    GAP_CHECK("f_io_selected_data", test_file, f_io_selected_data, f_io_selected_module, 1);
+    GAP_CHECK("f_io_requests", test_file, f_io_requests, f_io_selected_data, 1);
+    GAP_CHECK("f_io_requests_lock", test_file, f_io_requests_lock, f_io_requests, 1);
+    
+    return 0;
+}