Looks like what he really wants is to use Ada which has had much better support for low-level programming than C.

Example:

Word : constant := 4; -- storage element is byte, 4 bytes per word

type State is (A,M,W,P); type Mode is (Fix, Dec, Exp, Signif);

type Byte_Mask is array (0..7) of Boolean; type State_Mask is array (State) of Boolean; type Mode_Mask is array (Mode) of Boolean;

type Program_Status_Word is record System_Mask : Byte_Mask;

       Protection_Key     : Integer range 0 .. 3;

       Machine_State      : State_Mask;

       Interrupt_Cause    : Interruption_Code;

       Ilc                : Integer range 0 .. 3;

       Cc                 : Integer range 0 .. 3;

       Program_Mask       : Mode_Mask;

       Inst_Address       : Address;

 end record;

 for Program_Status_Word use

   record
       System_Mask      at 0*Word range 0  .. 7;

       Protection_Key   at 0*Word range 10 .. 11; -- bits 8,9 unused

       Machine_State    at 0*Word range 12 .. 15;

       Interrupt_Cause  at 0*Word range 16 .. 31;

       Ilc              at 1*Word range 0  .. 1;  -- second word

       Cc               at 1*Word range 2  .. 3;

       Program_Mask     at 1*Word range 4  .. 7;

       Inst_Address     at 1*Word range 8  .. 31;

   end record;

 for Program_Status_Word'Size use 8*System.Storage_Unit;

 for Program_Status_Word'Alignment use 8;

More info: https://www.adaic.org/resources/add_content/standards/05aarm...