Language/OS - Multiplatform Resource Library/LANGUAGE OS.iso/prolog/modprolg/mod-prol.lha/Prolog/modlib/src/$dbcmpl.P

Text File | 1992-04-25 | 18.1 KB | 559 lines

/* modified with labels 32/33 in buff_code */
/************************************************************************
*                                    *
* The SB-Prolog System                            *
* Copyright SUNY at Stony Brook, 1986; University of Arizona, 1987    *
*                                    *
************************************************************************/

/*-----------------------------------------------------------------
SB-Prolog is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY.  No author or distributor
accepts responsibility to anyone for the consequences of using it
or for whether it serves any particular purpose or works at all,
unless he says so in writing.  Refer to the SB-Prolog General Public
License for full details.

Everyone is granted permission to copy, modify and redistribute
SB-Prolog, but only under the conditions described in the
SB-Prolog General Public License.   A copy of this license is
supposed to have been given to you along with SB-Prolog so you
can know your rights and responsibilities.  It should be in a
file named COPYING.  Among other things, the copyright notice
and this notice must be preserved on all copies.
------------------------------------------------------------------ */
/* $dbcmpl.P */

/* This file contains Prolog predicates that compiles a clause into a
buffer. It treats all rules as though they had a single literal on the
right-hand-side. Thus it compiles a clause with more than one literal
on the right-hand-side as a call to the predicate ,/2 */

$dbcmpl_export([$db_cmpl/5,$db_putbuffop/4,$db_putbuffbyte/4,
    $db_putbuffnum/4]).

% $dbcmpl_use : $buff, $bmeta, $bio

$db_putbuffop(Opn,Buff,Li,Lo) :-
    $buff_code(Buff, Li, 3 /*ps*/ ,Opn), Lo is Li+2.

$db_putbuffope(Opn,Buff,Li,Lo) :-
    $buff_code(Buff, Li,  3 /*ps*/ ,Opn), Li1 is Li+2,
    $buff_code(Buff, Li1, 3 /*ps*/ ,0),   Lo  is Li1+2.

$db_putbuffbyte(Num,Buff,Li,Lo) :-
    $buff_code(Buff, Li, 3 /*ps*/ ,Num), Lo is Li+2.

$db_putbuffnum(Num,Buff,Li,Lo) :-
    $buff_code(Buff, Li, 32 /*pn*/ ,Num), Lo is Li+4.

$db_putbuffloat(Num,Buff,Li,Lo) :-
    $buff_code(Buff, Li, 27 /*pf*/ ,Num), Lo is Li+4.

$db_putbuffptr(Num,Buff,Li,Lo) :-
    $buff_code(Buff, Li, 1 /*pppsc*/ ,Num), Lo is Li+4.

$db_putbuffpsc(Num,Buff,Li,Lo) :-
    $buff_code(Buff, Li, 0 /*ppsc*/ ,Num), Lo is Li+4.


/* $db_cmpl(Clause,Clref,Index,Where,Supbuff): where Clause is a fact or
rule. Clref is a variable through which is returned the Clref, and
Index is the argument to index on (0 if none). Where is 0 if the
buffer is to be allocated from the permanent area, and 2 if from a
superbuff, which is in Supbuff. */

$db_cmpl(Clause,Buff,Index,Where,Supbuff) :-
    $alloc_buff(10000,Buff,Where,Supbuff,_),    /* must return Buff */
    ((Clause ?= (_:-_) -> Clause=(Head:-Body); Clause=Head, Body=true),
     $arity(Head,Arity),
     Tempreg is Arity+1,
     $buff_code(Buff, 0, 14 /*ptv*/ ,Buff), /*set back pointer*/
         $opcode( noop, NoOp ),
     $db_putbuffop(NoOp, Buff, 12, _),
     $buff_code(Buff, 14, 3, 2),  /* skip next 2*2 = 4 bytes */
     $db_putbuffpsc(Head, Buff, 16, _),
     $db_gentop(Head,Arity,1,Tempreg,Freereg,Buff,20,Lhd,uniq),
     $db_flatten(Body,FBody,[],Unifs),
     $db_flcode(Unifs,Freereg,R0,Buff,Lhd,Lm0,uniq),
     $arity(FBody,Barity),
     $db_genbod(FBody,Barity,1,[],Mvl,R0,Maxreg,Buff,Lm0,Lm1,uniq),
     (Index > 0 -> $db_putbuffchain(Buff, Lm1, Length);
                Length = Lm1),
     (Length > 10000,!,
             $db_mfail('Asserted clause too long ',Length);
      Length =< 10000,
       (Maxreg > 255,!,
         $db_mfail('Assert: too many registers required ',Maxreg);
        Maxreg =< 255,
         $trimbuff(Length,Buff,Where,Supbuff), fail
       )
     )
    ;
     true
    ).


$db_mfail(Msg,Val) :-
    $telling(F),$tell(user),
    $writename(Msg),$writename(Val),$nl,
    $tell(F),fail.

$db_putbuffchain(Buff, Lin, Lout) :-
        /* put code at the end for chaining clauses in the same bucket  */
        $opcode( noop, NoopOp ),
        $opcode( jump, JmpOp ),
    $db_putbuffop(   NoopOp /* noop */, Buff, Lin, L1),
        $db_putbuffbyte(  2, Buff, L1, L2),   /* 2 noop's */
        $db_putbuffnum(   0, Buff, L2, L3),
        $db_putbuffope(  JmpOp /* jump */, Buff, L3, L4),
        $buff_code(Buff, 12, 33, EPADDR), /* get start address of the code*/
        $db_putbuffnum(EPADDR, Buff, L4, Lout).

$db_gentop(Fact,Arity,Argno,Ri,Ro,Buff,Li,Lo,U) :-
    Argno > Arity,
     Ri = Ro, Li=Lo
    ;
    Argno =< Arity, arg(Argno,Fact,T),
     $db_gentopinst(T,Argno,Ri,Rm,Buff,Li,Lm,U),
     Argno1 is Argno + 1,
     $db_gentop(Fact,Arity,Argno1,Rm,Ro,Buff,Lm,Lo,U).

$db_gentopinst(T,Argno,Ri,Ro,Buff,Li,Lo,U) :-
    var(T), T='$var'(Argno,U), Ri = Ro, Li = Lo
    ;
    nonvar(T),
     ($atom(T) ->
       ((T ?= [] ->
         ($opcode( getnil, GetNilOp ),
                  $db_putbuffop(GetNilOp,Buff,Li,Li1),  /* getnil(Argno) */
          $db_putbuffbyte(Argno,Buff,Li1,Lo)
           ) ;
         ($opcode( getcon, GetConOp ),
                  $db_putbuffop(GetConOp,Buff,Li,Li1),   /* getcon(T,Argno) */
             $db_putbuffbyte(Argno,Buff,Li1,Li2),
             $db_putbuffptr(T,Buff,Li2,Lo)
           )
        ),
        Ri = Ro
       ) ;
       (integer(T) ->             /* getnumcon(T,Argno) */
        ($opcode( getnumcon, GetNumOp ),
                 $db_putbuffop(GetNumOp,Buff,Li,Li1),
         $db_putbuffbyte(Argno,Buff,Li1,Li2),
         $db_putbuffnum(T,Buff,Li2,Lo),
         Ri = Ro
        ) ;
        (real(T) ->             /* getfloatcon(T,Argno) */
            ($opcode( getfloatcon, GetFltOp ),
                        $db_putbuffop(GetFltOp,Buff,Li,Li1),
             $db_putbuffbyte(Argno,Buff,Li1,Li2),
             $db_putbuffloat(T,Buff,Li2,Lo),
             Ri = Ro
            ) ;
            ((T='$var'(Rt,Un), nonvar(Un), Un=U ) ->
                     /* gettval(Rt,Argno) */
                ($opcode( gettval, GetTValOp ),
                                 $db_putbuffope(GetTValOp,Buff,Li,Li1),
                   $db_putbuffbyte(Rt,Buff,Li1,Li2),
                   $db_putbuffbyte(Argno,Buff,Li2,Lo),
                   Ri = Ro
                ) ;
                $db_genterms([Argno,T],Ri,Ro,Buff,Li,Lo,U)
            )
            )
        )
     ).

$db_genterms([],R,R,_,L,L,_).
$db_genterms([R,T|Ts],Ri,Ro,Buff,Li,Lo,U) :-
    $db_genstruc(T,R,Buff,Ri,Rm,Li,Lm2,Substrs,U),
    $db_genterms(Substrs,Rm,Rm2,Buff,Lm2,Lm3,U),
    $db_genterms(Ts,Rm2,Ro,Buff,Lm3,Lo,U).

$db_genstruc((A1,A2),R,Buff,Ri,Ro,Li,Lo,[],U) :-
    var(A1),var(A2),A1 \== A2,!,A1 = '$var'(Ri,U),
    Rm1 is Ri+1, A2 = '$var'(Rm1,U), Ro is Rm1+1,
    /* generate a getcomma_tvar_tvar */
    $opcode( getcomma_tvar_tvar, GetCTvTvOp ),
    $db_putbuffop( GetCTvTvOp,Buff,Li,Lm1),
    $db_putbuffbyte(R,Buff,Lm1,Lm2),
    $db_putbuffbyte(Ri,Buff,Lm2,Lm3),
    $db_putbuffbyte(Rm1,Buff,Lm3,Lo).

$db_genstruc([A1|A2],R,Buff,Ri,Ro,Li,Lo,[],U) :-
    var(A1),var(A2),not(A1==A2),!,A1 = '$var'(Ri,U),
    Rm1 is Ri+1, A2 = '$var'(Rm1,U), Ro is Rm1+1,
    /* generate a getlist_tvar_tvar */
    $opcode( getlist_tvar_tvar, GetLTvTvOp ),
    $db_putbuffop( GetLTvTvOp,Buff,Li,Lm1),
    $db_putbuffbyte(R,Buff,Lm1,Lm2),
    $db_putbuffbyte(Ri,Buff,Lm2,Lm3),
    $db_putbuffbyte(Rm1,Buff,Lm3,Lo).

$db_genstruc(T,R,Buff,Ri,Rm,Li,Lo,Substrs,U) :-
    $db_genget(T,R,Buff,Li,Lm1),$arity(T,Arity),
    $db_dosubs(T,0,Arity,Ri,Rm,Buff,Lm1,Lo,Substrs,[],U).


$db_genget([_|_],R,Buff,Li,Lo) :- !,
    /* getlist(R) */
    $opcode( getlist, GetLOp ),
    $db_putbuffop( GetLOp,Buff,Li,Li1),
    $db_putbuffbyte(R,Buff,Li1,Lo).

$db_genget((_,_),R,Buff,Li,Lo) :- /* not(T=[_|_]) */ !,
    /* getcomma(R) */
    $opcode( getcomma, GetCOp ),
    $db_putbuffop( GetCOp,Buff,Li,Li1),
    $db_putbuffbyte(R,Buff,Li1,Lo).

$db_genget(T,R,Buff,Li,Lo) :- /* not(T=(_,_)),not(T=[_|_]) */
    /* $functor(T,F,Arity), getstr((F,Arity),R) */
    $opcode( getstr, GetSOp ),
    $db_putbuffop( GetSOp,Buff,Li,Li1),
    $db_putbuffbyte(R,Buff,Li1,Li2),
    $db_putbuffpsc(T,Buff,Li2,Lo).

$db_dosubs(T,I,Arity,Ri,Ro,Buff,Li,Lo,Si,So,U) :-
    I < Arity, I1 is I+1, arg(I1,T,Sub),
     $db_geninst(Sub,Ri,Rm,Si,Sm,Buff,Li,Lm,U),
     $db_dosubs(T,I1,Arity,Rm,Ro,Buff,Lm,Lo,Sm,So,U)
    ;
    I >= Arity,        /* just to avoid having to lay down a CP */
     I = Arity,Ri = Ro,Li = Lo,Si = So.

$db_geninst(Sub,Ri,Ro,Si,So,Buff,Li,Lo,U) :-
    var(Sub), Si = So,
      Ro is Ri+1, Sub='$var'(Ri,U),     /* unitvar(Ri) */
          $opcode( unitvar, UniTvarOp1 ),
      $db_putbuffop(UniTvarOp1,Buff,Li,Li1),
      $db_putbuffbyte(Ri,Buff,Li1,Lo)
     ;
      nonvar(Sub),
         ($atom(Sub) ->
            ((Sub ?= [] ->
                 $opcode( uninil, UniNOp ),
                     $db_putbuffope(UniNOp,Buff,Li,Lo) ;   /* uninil */
                 ($opcode( unicon, UniCOp ),
                      $db_putbuffope(UniCOp,Buff,Li,Li1),  /* unicon(Sub) */
              $db_putbuffptr(Sub,Buff,Li1,Lo))
         ),
          Ri = Ro, Si = So) ;
        (integer(Sub) ->               /* uninumcon(Sub) */
              ($opcode( uninumcon, UniNCOp ),
                       $db_putbuffope(UniNCOp,Buff,Li,Li1),
               $db_putbuffnum(Sub,Buff,Li1,Lo),
               Ri = Ro, Si = So) ;
               (real(Sub) ->               /* unifloatcon(Sub) */
                      ($opcode( unifloatcon, UniFltOp ),
                             $db_putbuffope(UniFltOp,Buff,Li,Li1),
                        $db_putbuffloat(Sub,Buff,Li1,Lo),
                     Ri = Ro, Si = So) ;
                     ((Sub='$var'(R,Un),nonvar(Un),Un=U) ->
                            /* unitval(R) */
                    ($opcode( unitval, UniTvalOp ),
                                 $db_putbuffop(UniTvalOp,Buff,Li,Li1),
                      $db_putbuffbyte(R,Buff,Li1,Lo),
                      Ri = Ro, Si = So) ;
                    (Ro is Ri+1,        /* unitvar(Ri) */
                      Si = [Ri,Sub|So],
                                 $opcode( unitvar, UniTvarOp2 ),
                      $db_putbuffop(UniTvarOp2,Buff,Li,Li1),
                      $db_putbuffbyte(Ri,Buff,Li1,Lo))
                       )
            )
        )
         ).

$db_genbod(true,0,1,Mvlst,Mvlst,R,R,Buff,Li,Lo,U) :- !,
    $opcode( proceed, ProOp ),
    $db_putbuffope( ProOp /*proceed*/ ,Buff,Li,Lo).

$db_genbod(Body,Arity,Argno,Mvlst,Mvlsto,Ri,Ro,Buff,Locin,Locout,U) :-
    $db_genbo1(Body,Arity,Argno,Mvlst,Mvlsto,Ri,Ro,Buff,Locin,Locout,U).

$db_genbo1(Body,Arity,Argno,Mvlst,Mvlsto,Ri,Ro,Buff,Locin,Locout,U) :-
    Argno > Arity ->
     Mvlst=Mvlsto,
     $db_genmvs(Mvlst,Ri,Ro,Buff,Locin,Lm1),
     $functor(Body,Bodyn,Arity), /* wnl(execute(Bodyn,Arity)), */
         $opcode( execute, ExecOp ),
     $db_putbuffope( ExecOp,Buff,Lm1,Lm2),
     $db_putbuffpsc(Body,Buff,Lm2,Locout)
    ;
     arg(Argno,Body,T),
     $db_genaput(T,Argno,Mvlst,Mvlstm,Ri,Rm,Buff,Locin,Locm,U),
     Argno1 is Argno+1,
     $db_genbo1(Body,Arity,Argno1,Mvlstm,Mvlsto,Rm,Ro,Buff,Locm,Locout,U).

$db_genaput(T,Argno,Mvlst,Mvlsto,Ri,Ro,Buff,Locin,Locout,U) :-
    var(T) ->
     Ro is Ri+1,Locout=Locin,Mvlsto=[puttvar(Tempvar),Argno|Mvlst],
     T='$var'(Tempvar,U)
    ;
     (T='$var'(Rt,U) ->
       (var(Rt) -> Mvlsto=[puttvar(Rt),Argno|Mvlst];
               Mvlsto=[movreg(Rt),Argno|Mvlst]),
       Ro=Ri,Locout=Locin
      ;
       (integer(T) ->
         Mvlsto=[putnumcon(T),Argno|Mvlst],Ro=Ri,Locout=Locin
        ;
         (real(T) ->
           (Mvlsto=[putfloatcon(T),Argno|Mvlst],Ro=Ri,Locout=Locin)
          ;
          ($atom(T) ->
        (T ?= [] -> Mvlsto=[putnil,Argno|Mvlst];
             Mvlsto=[putcon(T),Argno|Mvlst]),
        Ro=Ri,Locout=Locin
          ;
        Mvlsto=[movreg(Ri),Argno|Mvlst],Rm is Ri+1,
            $db_putterm(Ri,T,Rm,Ro,Buff,Locin,Locout,U)
         )
       )
     )
    ).

$db_putterm(R,T,Ri,Ro,Buff,Li,Lo,U) :-
    $arity(T,Arity),
    $db_putsubstr(T,0,Arity,Ri,Rm,Buff,Li,Lm1,[],Subterms,U),
    $db_genputstr(T,R,Buff,Lm1,Lm2),
    $db_putsubs(Subterms,Rm,Ro,Buff,Lm2,Lo).

$db_genputstr([_|_],R,Buff,Li,Lo) :- !,
    /* wnl(putlist(R)), */
    $opcode( putlist, PutLOp ),
    $db_putbuffop(PutLOp,Buff,Li,Li1),
    $db_putbuffbyte(R,Buff,Li1,Lo).

$db_genputstr(T,R,Buff,Li,Lo) :- /* not(T=(_,_)),not(T=[_|_]) */
    /* $functor(T,F,Arity), wnl(putstr((F,Arity),R)), */
    $opcode( putstr, PutSOp ),
    $db_putbuffop(PutSOp,Buff,Li,Li1),
    $db_putbuffbyte(R,Buff,Li1,Li2),
    $db_putbuffpsc(T,Buff,Li2,Lo).

$db_putsubstr(T,I,Arity,Ri,Ro,Buff,Li,Lo,Si,So,U) :-
    I < Arity -> I1 is I+1, arg(I1,T,Sub),
     $db_bldsubs(Sub,Ri,Rm,Si,Sm,Buff,Li,Lm,U),
     $db_putsubstr(T,I1,Arity,Rm,Ro,Buff,Lm,Lo,Sm,So,U)
    ;
     I = Arity,Ri = Ro,Li = Lo,Si = So.

$db_bldsubs(Sub,Ri,Ro,Si,So,Buff,Li,Lo,U) :-
    var(Sub) -> So = [bldtvar(Ri)|Si],
      Ro is Ri+1, Li = Lo, Sub='$var'(Ri,U)     /* bldtvar(Ri) */
     ;
      ($atom(Sub) ->
         (Sub ?= [] -> So = [bldnil|Si];    /* bldnil */
            So = [bldcon(Sub)|Si]), /* bldcon(Sub) */
         Ri = Ro, Li = Lo
        ;
         (integer(Sub) ->               /* bldnumcon(Sub) */
        So = [bldnumcon(Sub)|Si], Ri = Ro, Li = Lo
          ;
            (real(Sub) ->               /* bldfloatcon(Sub) */
           (So = [bldfloatcon(Sub)|Si], Ri = Ro, Li = Lo) ;
           ((Sub='$var'(R,Un),nonvar(Un),Un=U) ->
              So = [bldtval(R)|Si],    /* bldtval(R) */
              Ri = Ro,Li = Lo
             ;
              Rm is Ri+1,        /* bldtvar(Ri) */
              So = [bldtval(Ri)|Si],
              $db_putterm(Ri,Sub,Rm,Ro,Buff,Li,Lo,U)
          )
        )
         )
      ).

$db_putsubs([],R,R,_,L,L).
$db_putsubs([Bld|Rest],Ri,Ro,Buff,Li,Lo) :-
    $db_putsubs(Rest,Ri,Ro,Buff,Li,Lm),
    $db_bldinst(Bld,Buff,Lm,Lo).

:- mode($db_bldinst,4,[c,d,d,d]).

$db_bldinst(bldtvar(R),Buff,Li,Lo) :-
    /* wnl(bldtvar(R)), */
    $opcode( bldtvar, BldOp ),
    $db_putbuffop(BldOp,Buff,Li,Li1),
    $db_putbuffbyte(R,Buff,Li1,Lo).
$db_bldinst(bldnil,Buff,Li,Lo) :-
    /* wnl(bldnil), */
    $opcode( bldnil, BldOp ),
    $db_putbuffope(BldOp,Buff,Li,Lo).
$db_bldinst(bldcon(Sub),Buff,Li,Lo) :-
    /* wnl(bldcon(Sub)), */
    $opcode( bldcon, BldOp ),
    $db_putbuffope(BldOp,Buff,Li,Li1),
    $db_putbuffptr(Sub,Buff,Li1,Lo).
$db_bldinst(bldnumcon(Sub),Buff,Li,Lo) :-
    /* wnl(bldnumcon(Sub)), */
    $opcode( bldnumcon, BldOp ),
    $db_putbuffope(BldOp,Buff,Li,Li1),
    $db_putbuffnum(Sub,Buff,Li1,Lo).
$db_bldinst(bldfloatcon(Sub),Buff,Li,Lo) :-
    /* wnl(bldfloatcon(Sub)), */
    $opcode( bldfloatcon, BldOp ),
    $db_putbuffope(BldOp,Buff,Li,Li1),
    $db_putbuffloat(Sub,Buff,Li1,Lo).
$db_bldinst(bldtval(R),Buff,Li,Lo) :-
    /* wnl(bldtval(R)), */
    $opcode( bldtval, BldOp ),
    $db_putbuffop(BldOp,Buff,Li,Li1),
    $db_putbuffbyte(R,Buff,Li1,Lo).


/* this is a simple routine to generate  a series  of instructions to
load a series of  registers with  constants or  from other registers.
It is  given a  list of  Source,Target pairs.   Target  is always a
register  number.  Source may be a putcon(con), putnumcon(num), putfloatcon(num),
puttvar(reg),  puttvar(Var),  or  movreg(reg).    The  registers  can
overlap in any way.  $db_genmvs tries to generate  a reasonably efficient
series  of  instructions  to  load  the indicated  registers with the
indicated values.  */

$db_genmvs([],R,R,B,L,L).
$db_genmvs([I,T|Rest],Ri,Ro,Buff,Li,Lo) :- $db_genmvs(I,T,Ri,Ro,Buff,Li,Lo,Rest).

:- mode($db_genmvs,8,[c,c,d,d,d,d,d,d]).

$db_genmvs(puttvar(R),T,Ri,Ro,Buff,Li,Lo,Rest) :-
    $db_genmvs(Rest,Ri,Ro,Buff,Li,Lm),
    (nonvar(R) ->
        /* wnl(movreg(R,T)), */
        $opcode( movreg, MovOp ),
                $db_putbuffope( MovOp,Buff,Lm,Lm1),
        $db_putbuffbyte(R,Buff,Lm1,Lm2),
        $db_putbuffbyte(T,Buff,Lm2,Lo)
      ;
        R=T, /* wnl(puttvar(R,R)), */
        $opcode( puttvar, PutOp ),
                $db_putbuffope(PutOp,Buff,Lm,Lm1),
        $db_putbuffbyte(R,Buff,Lm1,Lm2),
        $db_putbuffbyte(R,Buff,Lm2,Lo)
    ).

$db_genmvs(putcon(C),T,Ri,Ro,Buff,Li,Lo,Rest) :- !,
    $db_genmvs(Rest,Ri,Ro,Buff,Li,Lm),
    /* wnl(putcon(T,C)), */
    $opcode( putcon, PutOp ),
    $db_putbuffop(PutOp,Buff,Lm,Lm1),
    $db_putbuffbyte(T,Buff,Lm1,Lm2),
    $db_putbuffptr(C,Buff,Lm2,Lo).

$db_genmvs(putnil,T,Ri,Ro,Buff,Li,Lo,Rest) :- !,
    $db_genmvs(Rest,Ri,Ro,Buff,Li,Lm),
    /* wnl(putnil(T)), */
    $opcode( putnil, PutOp ),
    $db_putbuffop(PutOp,Buff,Lm,Lm1),
    $db_putbuffbyte(T,Buff,Lm1,Lo).

$db_genmvs(putnumcon(I),T,Ri,Ro,Buff,Li,Lo,Rest) :- !,
    $db_genmvs(Rest,Ri,Ro,Buff,Li,Lm),
    /* wnl(putnumcon(T,I)), */
    $opcode( putnumcon, PutOp ),
    $db_putbuffop(PutOp,Buff,Lm,Lm1),
    $db_putbuffbyte(T,Buff,Lm1,Lm2),
    $db_putbuffnum(I,Buff,Lm2,Lo).

$db_genmvs(putfloatcon(I),T,Ri,Ro,Buff,Li,Lo,Rest) :- !,
    $db_genmvs(Rest,Ri,Ro,Buff,Li,Lm),
    /* wnl(putfloatcon(T,I)), */
    $opcode( putfloatcon, PutOp ),
    $db_putbuffop(PutOp,Buff,Lm,Lm1),
    $db_putbuffbyte(T,Buff,Lm1,Lm2),
    $db_putbuffloat(I,Buff,Lm2,Lo).

$db_genmvs(movreg(R),R,Ri,Ro,Buff,Li,Lo,Rest) :- !,
    $db_genmvs(Rest,Ri,Ro,Buff,Li,Lo).

$db_genmvs(movreg(S),T,Ri,Ro,Buff,Li,Lo,Rest) :- not($dbcmpl_frstmem(T,Rest)),!,
    /* wnl(movreg(S,T)), */
    $opcode( movreg, MovOp ),
    $db_putbuffope( MovOp,Buff,Li,Lm1),
    $db_putbuffbyte(S,Buff,Lm1,Lm2),
    $db_putbuffbyte(T,Buff,Lm2,Lm),
    $db_genmvs(Rest,Ri,Ro,Buff,Lm,Lo).

$db_genmvs(movreg(S),T,Ri,Ro,Buff,Li,Lo,Rest) :-
    not($dbcmpl_scndmem(S,Rest)), !,
    $db_genmvs(Rest,Ri,Ro,Buff,Li,Lm),
    /* wnl(movreg(S,T)), */
    $opcode( movreg, MovOp ),
    $db_putbuffope( MovOp,Buff,Lm,Lm1),
    $db_putbuffbyte(S,Buff,Lm1,Lm2),
    $db_putbuffbyte(T,Buff,Lm2,Lo).

$db_genmvs(movreg(S),T,Ri,Ro,Buff,Li,Lo,Rest) :-
    /* wnl(movreg(S,Ri)), */
    $opcode( movreg, MovOp ),
    $db_putbuffope( MovOp,Buff,Li,Lm1),
    $db_putbuffbyte(S,Buff,Lm1,Lm2),
    $db_putbuffbyte(Ri,Buff,Lm2,Lm3),
    Rm is Ri+1,
    $db_genmvs(Rest,Rm,Ro,Buff,Lm3,Lm4),
    /* wnl(movreg(Ri,T)), */
    $db_putbuffope( MovOp,Buff,Lm4,Lm5),
    $db_putbuffbyte(Ri,Buff,Lm5,Lm6),
    $db_putbuffbyte(T,Buff,Lm6,Lo).


/* wnl(X) :- write(X),nl. */


$dbcmpl_frstmem(T,[movreg(T),_|_]).
$dbcmpl_frstmem(T,[_|Rest]) :- $dbcmpl_frstmem(T,Rest).


$dbcmpl_scndmem(S,[_,S|_]).
$dbcmpl_scndmem(S,[_|Rest]) :- $dbcmpl_scndmem(S,Rest).

/*  This is a kludge to fix up a problem with the depth-first
    traversal of arguments interacting in a bad way with the
    flattening of terms.  The problem is that when translating
    arguments in the body, the depth first traversal doesn't take
    into account the fact that subterms may move forward due to
    flattening, thereby changing "first" and "subsequent"
    occurrences of variables.  To make things work, though much
    less efficiently than before, I'm just going through an
    explicit flattening stage beforehand.  I don't doubt there
    are more elegant solutions, I'm just a user who wants to
    use assert to do other things. --skd, Sept. 1986        */

$db_flatten(Term,NewTerm,Si,So) :-
    $structure(Term) ->
        ($functor(Term,F,N),
         $functor(NewTerm,F,N),
         $db_flatten1(Term,0,N,NewTerm,Si,So)
        );
        (NewTerm = Term, Si = So).

$db_flatten1(Term,N,Arity,NewTerm,Si,So) :-
    (N =:= Arity) ->
        (Si = So) ;
        (ArgNo is N + 1,
         arg(ArgNo,Term,OldArg),
         arg(ArgNo,NewTerm,NewArg),
         (($structure(OldArg), OldArg \= '$var'(_,_)) ->
                   /* nested structure, needs flattening */
             (Sm0 = [NewArg,NewArg0|Si],
             $db_flatten(OldArg,NewArg0,Sm0,Sm1)
            ) ;
            (OldArg = NewArg, Sm1 = Si)
         ),
         N1 is N + 1,
         $db_flatten1(Term,N1,Arity,NewTerm,Sm1,So)
        ).

$db_flcode([],R,R,_Buff,Loc,Loc,_).
$db_flcode([Temp,Str|Rest],Ri,Ro,Buff,Li,Lo,U) :-
    Temp = '$var'(R,U),
    ((var(R), R = Ri, Rm0 is Ri+1) ;
     (nonvar(R), Rm0 = Ri)
    ),
    $db_putterm(R,Str,Rm0,Rm1,Buff,Li,Lm,U),
    $db_flcode(Rest,Rm1,Ro,Buff,Lm,Lo,U).