!Copyright © 1993, MadGoat Software.  All Rights Reserved.
COMPILETIME
    _FLD_CUR_BYT    = 0,
    _FLD_CUR_BIT    = 0,
    _FLD_SAV_BYT    = 0,
    _FLD_SAV_BIT    = 0,
    _FLD_WRK_SIZE   = 0,
    _FLD_WRK_BITS   = 0,
    _FLD_FLD_COUNT  = 0;

MACRO
    _DEF (NAM) =
    	%ASSIGN (_FLD_CUR_BYT, 0)
    	%ASSIGN (_FLD_CUR_BIT, 0)
    	%ASSIGN (_FLD_FLD_COUNT, 0)
    	FIELD
    	    %QUOTENAME (NAM, '_FIELDS') = SET
    %,

    _ENDDEF (NAM) =
    	TES;
    	%IF _FLD_CUR_BIT GTR 0 %THEN
    	    %ASSIGN (_FLD_CUR_BYT, _FLD_CUR_BYT + 1)
    	%FI
    	LITERAL %NAME (NAM, '_S_', NAM, 'DEF') = _FLD_CUR_BYT;
    	MACRO %NAME (NAM, 'DEF') =
    	    BLOCK [%NAME (NAM, '_S_', NAM, 'DEF'), BYTE]
    	    FIELD (%NAME (NAM, '_FIELDS')) %QUOTE %
    %,

    _FIELD (SIZ) =
    	%ASSIGN (_FLD_FLD_COUNT, _FLD_FLD_COUNT+1)
    	%ASSIGN (_FLD_WRK_BITS, %IF SIZ GTR 32 %THEN 0 %ELSE SIZ %FI)

    	[_FLD_CUR_BYT,_FLD_CUR_BIT,_FLD_WRK_BITS,0]

    	%ASSIGN (_FLD_WRK_BITS, _FLD_CUR_BYT * 8 + _FLD_CUR_BIT + SIZ)
    	%ASSIGN (_FLD_CUR_BYT, _FLD_WRK_BITS / 8)
    	%ASSIGN (_FLD_CUR_BIT, _FLD_WRK_BITS MOD 8)
    %,

    _BYTE = 
    	_ALIGN (BYTE)
    	_FIELD (8)
    %,

    _BYTES (COUNT) =
    	_ALIGN (BYTE)
    	_FIELD ((COUNT) * 8)
    %,

    _WORD =
    	_ALIGN (BYTE)
    	_FIELD (16)
    %,

    _LONG =
    	_ALIGN (BYTE)
    	_FIELD (32)
    %,

    _QUAD =
    	_ALIGN (BYTE)
    	_FIELD (64)
    %,

    _BIT =
    	_FIELD (1)
    %,

    _BITS (N) =
    	_FIELD ((N))
    %,

    _OVERLAY (NAM) =
    	%ASSIGN (_FLD_SAV_BYT, _FLD_CUR_BYT)
    	%ASSIGN (_FLD_SAV_BIT, _FLD_CUR_BIT)
    	%ASSIGN (_FLD_CUR_BYT, %FIELDEXPAND (NAM, 0))
    	%ASSIGN (_FLD_CUR_BIT, %FIELDEXPAND (NAM, 1))
    %,

    _ENDOVERLAY =
    	%ASSIGN (_FLD_CUR_BYT, _FLD_SAV_BYT)
    	%ASSIGN (_FLD_CUR_BIT, _FLD_SAV_BIT)
    %,

    _ALIGN (ATYPE) =
    	%ASSIGN (_FLD_WRK_BITS, 0)
    	%ASSIGN (_FLD_WRK_SIZE,
    	    %IF %IDENTICAL (ATYPE, BYTE) %THEN 1
    	    %ELSE %IF %IDENTICAL (ATYPE, WORD) %THEN 2
    	    %ELSE %IF %IDENTICAL (ATYPE, LONG) %THEN 4
    	    %ELSE %IF %IDENTICAL (ATYPE, QUAD) %THEN 8
    	    %ELSE ATYPE %FI %FI %FI %FI)

    	%IF _FLD_CUR_BIT NEQ 0 %THEN
    	    %ASSIGN (_FLD_WRK_BITS, 8 - _FLD_CUR_BIT)
    	    %IF _FLD_CUR_BYT+1 MOD _FLD_WRK_SIZE NEQ 0 %THEN
    	    	%ASSIGN (_FLD_WRK_BITS, _FLD_WRK_BITS +
    	    	    (_FLD_WRK_SIZE - (_FLD_CUR_BYT+1) MOD _FLD_WRK_SIZE) * 8)
    	    %FI
    	%ELSE
    	    %IF _FLD_CUR_BYT MOD _FLD_WRK_SIZE NEQ 0 %THEN
    	    	%ASSIGN (_FLD_WRK_BITS,
    	    	    (_FLD_WRK_SIZE - _FLD_CUR_BYT MOD _FLD_WRK_SIZE) * 8)
    	    %FI
    	%FI
    	%IF _FLD_WRK_BITS GTR 0 %THEN
    	    %ASSIGN (_FLD_WRK_BITS,
    	    	_FLD_CUR_BYT * 8 + _FLD_CUR_BIT + _FLD_WRK_BITS)
    	    %ASSIGN (_FLD_CUR_BYT, _FLD_WRK_BITS / 8)
    	    %ASSIGN (_FLD_CUR_BIT, 0)
    	%FI
    %;