========================================
* Remove _then noop overhead for win32forth v4.2 0671. (by Lcc Wizard)

* Save about 5k space on win32for.img (1 cell per IF THEN),
  and lessen IF THEN overhead.

\ NCODE _THEN     ( -- )          \ "runtime" marker for the decompiler, a noop
\                next    c;
========================================
\ meta.f:
\ * replace then with:
T: THEN    ?>RESOLVE   T;
========================================
\ fkernel.f:
\ * replace then with:
: THEN   ?COMP  2 ?PAIRS >RESOLVE ; IMMEDIATE
========================================
\ see.f
\ * add:
: stk           ( stack-size -- ) create here , cells allot ;
: xpush         ( n stack -- ) 1 cells over +! @ ! ;
: xpop          ( stack -- n ) dup @ @ 1 cells negate rot +! ;
: xdrop         ( stack -- n ) xpop drop ;
: xdepth        ( stack -- n ) dup @ - negate 1 cells / ;
16 stk .then-stk
\ * modify:
: .execution-class  ( ip cfa -- ip' )
        ......
        ['] ?branch     of
                                d_cr ." IF      " +tab  cell+
                                dup @ over +  \ ." then addr=" dup .
                                .then-stk xpush
                                cell+ endof
        ['] branch      of
                                -tab d_cr ." ELSE    " +tab  cell+
                                dup @ over +  \ ." then addr=" dup .
                                .then-stk xdrop .then-stk xpush
                                cell+ endof
        ..... ;

: .PFA          ( cfa -- )
                .then-stk dup !
                tabing-on
                0TAB +TAB tab
                BEGIN
                        .then-stk xdepth 0 ?do
                                .then-stk xpop >r
                                dup @ ['] branch <>
                                over r@ >= and if
                                        -tab d_cr ." THEN    "  r> drop
                                else
                                        r> .then-stk xpush  leave
                                then
                        loop

                        14 ?line   DUP @ .EXECUTION-CLASS
                        DUP 0=
                        nuf? or
                UNTIL   DROP
                tabing-off ;