-w        ! enable warnings
-u        ! enable usage checking
-O207     ! hollerith constant warning
-O276     ! data type conversion
-O76      ! mixed mode arithmetic
-O261     ! initializer data type converted
-Ttrim    ! make TRIM the default tree format
--t       ! default is to NOT output tree
-Xno_unreferenced_parameters
-Xno_unused_common_variables
--x       ! default is to NOT output xref