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/*

 * Copyright (c) 2002-2005 The TenDRA Project <http://www.tendra.org/>.

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are met:

 *

 * 1. Redistributions of source code must retain the above copyright notice,

 *    this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright notice,

 *    this list of conditions and the following disclaimer in the documentation

 *    and/or other materials provided with the distribution.

 * 3. Neither the name of The TenDRA Project nor the names of its contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific, prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS

 * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,

 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;

 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,

 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR

 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF

 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 *

 * $Id$

 */

/*

    		 Crown Copyright (c) 1997

    This TenDRA(r) Computer Program is subject to Copyright

    owned by the United Kingdom Secretary of State for Defence

    acting through the Defence Evaluation and Research Agency

    (DERA).  It is made available to Recipients with a

    royalty-free licence for its use, reproduction, transfer

    to other parties and amendment for any purpose not excluding

    product development provided that any such use et cetera

    shall be deemed to be acceptance of the following conditions:-

        (1) Its Recipients shall ensure that this Notice is

        reproduced upon any copies or amended versions of it;

        (2) Any amended version of it shall be clearly marked to

        show both the nature of and the organisation responsible

        for the relevant amendment or amendments;

        (3) Its onward transfer from a recipient to another

        party shall be deemed to be that party's acceptance of

        these conditions;

        (4) DERA gives no warranty or assurance as to its

        quality or suitability for any purpose and DERA accepts

        no liability whatsoever in relation to any use to which

        it may be put.

*/

/* 80x86/codec.c */

/**********************************************************************

$Author: release $

$Date: 1998/01/17 15:55:51 $

$Revision: 1.1.1.1 $

$Log: codec.c,v $

 * Revision 1.1.1.1  1998/01/17  15:55:51  release

 * First version to be checked into rolling release.

 *

 * Revision 1.28  1997/08/23  13:45:19  pwe

 * initial ANDF-DE

 *

 * Revision 1.27  1996/10/07  13:30:54  pwe

 * push make_value, and env_offset v id out_of_line

 *

 * Revision 1.26  1996/05/20  14:30:00  pwe

 * improved 64-bit handling

 *

 * Revision 1.25  1996/05/13  12:51:44  pwe

 * undo premature commit

 *

 * Revision 1.23  1996/02/01  09:34:31  pwe

 * PIC oddities for AVS

 *

 * Revision 1.22  1996/01/31  12:24:11  pwe

 * is_crc v is_opnd  &  end_contop must not preceed move_reg

 *

 * Revision 1.21  1995/12/01  10:48:31  pwe

 * PIC static variables

 *

 * Revision 1.20  1995/10/11  17:16:08  pwe

 * error treatment for remainder

 *

 * Revision 1.19  1995/09/19  15:42:41  pwe

 * round, fp overflow etc

 *

 * Revision 1.18  1995/09/13  14:25:04  pwe

 * tidy for gcc

 *

 * Revision 1.17  1995/08/30  16:06:12  pwe

 * prepare exception trapping

 *

 * Revision 1.16  1995/08/23  09:42:21  pwe

 * track fpu control word for trap etc

 *

 * Revision 1.15  1995/08/14  13:53:15  pwe

 * several corrections, tail calls and error jumps

 *

 * Revision 1.14  1995/08/04  08:28:53  pwe

 * 4.0 general procs implemented

 *

 * Revision 1.13  1995/03/07  14:00:12  pwe

 * offset_pad byte->bit conversion

 *

 * Revision 1.12  1995/02/24  16:11:03  pwe

 * dynamic offsets, including mixed bit/byte representations

 *

 * Revision 1.11  1995/02/23  11:05:26  pwe

 * offset_div change variety after 32_bit division

 *

 * Revision 1.10  1995/02/13  11:16:56  pwe

 * REM etc should ignore overflow flag

 *

 * Revision 1.9  1995/02/10  14:36:39  pwe

 * consequence of correct test(reff,..) etc

 *

 * Revision 1.8  1995/02/10  12:58:11  pwe

 * correct test(reff,..) etc

 *

 * Revision 1.7  1995/02/08  17:21:03  pwe

 * remove incorrect overflow test after div

 *

 * Revision 1.6  1995/02/06  15:15:18  pwe

 * correct fp overflow check

 *

 * Revision 1.5  1995/02/02  15:17:21  pwe

 * implement offset_max as max

 *

 * Revision 1.4  1995/01/30  12:55:57  pwe

 * Ownership -> PWE, tidy banners

 *

 * Revision 1.3  1994/11/24  14:11:50  jmf

 * Cleared cond1_set after retcells

 *

 * Revision 1.2  1994/11/08  10:06:58  jmf

 * Added power not implemented

 *

 * Revision 1.1  1994/10/27  14:15:22  jmf

 * Initial revision

 *

 * Revision 1.1  1994/07/12  14:26:39  jmf

 * Initial revision

 *

**********************************************************************/

/**********************************************************************

                            codec.c

   codec produces code for operations which produce values.

   e is the operation and dest is where the result is to be put.

**********************************************************************/

#include "config.h"

#include "common_types.h"

#include "expmacs.h"

#include "exp.h"

#include "instr386.h"

#include "tags.h"

#include "operand.h"

#include "shapemacs.h"

#include "instrmacs.h"

#include "basicread.h"

#include "flags.h"

#include "coder.h"

#include "install_fns.h"

#include "codermacs.h"

#include "instr.h"

#include "flpt.h"

#include "messages_8.h"

#include "reg_record.h"

#include "readglob.h"

#include "externs.h"

#include "codec.h"

/* PROCEDURES */

/* returns true if is_o(e) but not a possible 80386 operand */

int is_crc

(exp e)

{

		/* make sure (is_o && is_crc -> !is_opnd) */

  if (name(e) == name_tag) {

    if (isvar(son(e)))

      return(!isglob(son(e)) || PIC_code);

    /* else */

      return(son(son(e)) == nilexp ||

	(isglob(son(e)) && PIC_code && name(sh(son(e))) == prokhd &&

			!(brog(son(e)) -> dec_u.dec_val.extnamed)) ||

	(name(son(son(e))) == ident_tag && isparam(son(son(e)))));

  }

  if (name(e) == reff_tag || name(e) == field_tag)

    return 1;

  if (name(e)!= cont_tag)

    return 0;

  if (name(son(e)) == cont_tag)

    return 1;

  return name(son(e)) == reff_tag &&

	  name(son(son(e))) == cont_tag;

}

/* op is a procedure for encoding a unary

   operation. If a is a possible 80386

   operand, uop applies this operator to

   produce the code for a, leaving the

   result in dest. sha gives the shape for

   the operation. If a is not a possible

   80386 operand, then uop produces code

   for a to put it into eax (reg0) and

   then applies op to eax, putting the

   result into dest. */

void uop

(void(*op)(shape, where, where), shape sha, exp a, where dest, ash stack)

{

  if (!is_o(name(a)) || is_crc(a)) {

    where qw;

    if (!inmem(dest))

      qw.where_exp = copyexp(dest.where_exp);

    else

      qw.where_exp = copyexp(reg0.where_exp);

    sh(qw.where_exp) = sha;

    qw.where_off = 0;

    coder(qw, stack, a);

   (*op)(sha, qw, dest);

    retcell(qw.where_exp);

    cond1_set = 0;

    return;

  };

 (*op)(sha, mw(a, 0), dest);

  return;

}

static int no_reg_needed

(exp e)

{

  if (name(e) == val_tag)

    return 1;

  if (name(e) == cont_tag &&

	name(son(e)) == name_tag &&

	isvar(son(son(e))) &&

	ptno(son(son(e)))!= reg_pl)

    return 1;

  if (name(e) == name_tag &&

	!isvar(son(e)) &&

	ptno(son(e))!= reg_pl)

    return 1;

  return 0;

}

/* op is a procedure for encoding a binary

   operation. Not more than one of a and b

   will not be a possible 80386 operand.

   This has been ensured by scan2. If a

   and b are both possible 80386 operands,

   bop applies this operator to produce

   the code, leaving the result in dest.

   sha gives the shape for the operation.

   If either a or b is not a possible

   80386 operand, then bop produces code

   for it to put it into eax (reg0) and

   then applies op to eax and the other

   operand, putting the result into dest.

*/

void bop

(void(*op)(shape, where, where, where), shape sha, exp a, exp b, where dest, ash stack)

{

  where qw;

  if (!is_o(name(a)) || is_crc(a)) {

    if (!inmem(dest) && no_reg_needed(b))

      qw.where_exp = copyexp(dest.where_exp);

    else

      qw.where_exp = copyexp(reg0.where_exp);

    sh(qw.where_exp) = sha;

    qw.where_off = 0;

    coder(qw, stack, a);

   (*op)(sha, qw, mw(b, 0), dest);

    retcell(qw.where_exp);

    cond1_set = 0;

    return;

  };

  if (!is_o(name(b)) || is_crc(b)) {

    if (!inmem(dest) && no_reg_needed(a))

      qw.where_exp = copyexp(dest.where_exp);

    else

      qw.where_exp = copyexp(reg0.where_exp);

    sh(qw.where_exp) = sha;

    qw.where_off = 0;

    coder(qw, stack, b);

   (*op)(sha, mw(a, 0), qw, dest);

    retcell(qw.where_exp);

    cond1_set = 0;

    return;

  };

 (*op)(sha, mw(a, 0), mw(b, 0), dest);

  return;

}

/* process the binary logical operation

   exp. op is the compiling procedure for

   the operation. It is commutative and

   associative, the operation takes a

   variable number of arguments. It is

   therefore necessary to avoid the

   mistake of assigning to the destination

   (dest) inappropriately if its value is

   used in the expression. At most one of

   the arguments will not be a possible

   80386 operand. If there is such an

   argument, logop precomputes it, putting

   the value into reg0. */

static void logop

(void(*op)(shape, where, where, where), exp e, where dest, ash stack)

{

  exp arg1 = son(e);

  exp arg2 = bro(arg1);

  shape sha = sh(e);

  exp t, u;

  where qw;

  if (last(arg1)) {

    coder(dest, stack, arg1);

    return;

  };

  if (last (arg2)) {		/* just two arguments. */

    bop(op, sha, arg1, arg2, dest, stack);

    return;

  };

  /* need to take care about overlap between dest and args or to avoid

     extra push. So use reg0. */

  qw.where_exp = copyexp(reg0.where_exp);

  sh(qw.where_exp) = sha;

  qw.where_off = 0;

  t = arg1;

  /* now look for an argument which is not a possible 80386 operand */

  while (1) {

    if (!is_o(name(t)) || is_crc(t))

      break;

    if (last(t)) {

      t = nilexp;

      break;

    };

    t = bro(t);

  };

  if (t == nilexp) {		/* all arguments are possible 80386

				   operands */

   (*op)(sha, mw(arg1, 0), mw(arg2, 0), qw);

    t = bro(arg2);

    while (!last(t)) {

      (*op) (sha, mw (t, 0), qw, qw);/* encode operations in turn */

      t = bro(t);

    };

    (*op) (sha, mw (t, 0), qw, dest);/* encode final operation */

    retcell(qw.where_exp);

    cond1_set = 0;

    return;

  };

  coder (qw, stack, t);		/* encode the single argument which is not

				   a possible 80386 operend */

  u = arg1;

  /* now encode the remaining operations */

  while (1) {

    if (t != u) {

      if (last(u) || (bro(u) == t && last(bro(u))))

	(*op)(sha, mw(u, 0), qw, dest);

      else

	(*op)(sha, mw(u, 0), qw, qw);

    };

    if (last(u))

      break;

    u = bro(u);

  };

  retcell(qw.where_exp);

  cond1_set = 0;

  return;

}

/* process the multiply operation

   exp. op is the compiling procedure for

   the operation. It is commutative and

   associative, the operation takes a

   variable number of arguments. It is

   therefore necessary to avoid the

   mistake of assigning to the destination

   (dest) inappropriately if its value is

   used in the expression. At most one of

   the arguments will not be a possible

   80386 operand. If there is such an

   argument, it is precomputed, putting

   the value into reg0. */

static void multop

(void(*op)(shape, where, where, where), exp e, where dest, ash stack)

{

  exp arg1 = son(e);

  exp arg2 = bro(arg1);

  exp t, u;

  where qw;

  if (last(arg1)) {

    coder(dest, stack, arg1);

    return;

  };

  if (last (arg2)) {		/* just two arguments. */

    bop(op, sh(e), arg1, arg2, dest, stack);

    return;

  };

  /* need to take care about overlap between dest and args or to avoid

     extra push. So use reg0. */

  qw.where_exp = copyexp(reg0.where_exp);

  sh(qw.where_exp) = sh(e);

  qw.where_off = 0;

  t = arg1;

  /* now look for an argument which is not a possible 80386 operand */

  while (1) {

    if (!is_o(name(t)) || is_crc(t))

      break;

    if (last(t)) {

      t = nilexp;

      break;

    };

    t = bro(t);

  };

  if (t == nilexp) {		/* all arguments are possible 80386

				   operands */

   (*op)(sh(e), mw(arg1, 0), mw(arg2, 0), qw);

    t = bro(arg2);

    while (!last(t)) {

      (*op) (sh (e), mw (t, 0), qw, qw);/* encode operations in turn */

      t = bro(t);

    };

    (*op) (sh (e), mw (t, 0), qw, dest);/* encode final operation */

    retcell(qw.where_exp);

    cond1_set = 0;

    return;

  };

  coder (qw, stack, t);		/* encode the single argument which is not

				   a possible 80386 operend */

  u = arg1;

  /* now encode the remaining operations */

  while (1) {

    if (t != u) {

      if (last(u) || (bro(u) == t && last(bro(u))))

	(*op)(sh(e), mw(u, 0), qw, dest);

      else

	(*op)(sh(e), mw(u, 0), qw, qw);

    };

    if (last(u))

      break;

    u = bro(u);

  };

  retcell(qw.where_exp);

  cond1_set = 0;

  return;

}

/* if a is a negation form b-son(a)

   otherwise b+a in dest */

static void addsub

(shape sha, where a, where b, where dest, exp e)

{

  UNUSED(e);

  if (name(a.where_exp) == neg_tag)

    sub(sha, mw(son(a.where_exp), 0), b, dest);

  else

    add(sha, a, b, dest);

  return;

}

/***********************************************************************

   codec outputs the code which evaulates e and puts the result into

   dest.

 ***********************************************************************/

/* encode e, putting the result into dest.

   stack is the current stack level */

void codec

(where dest, ash stack, exp e)

{

  switch (name(e)) {

    case plus_tag:

      {				/* at most one of the arguments will not

				   be a possible 80386 operand */

	exp arg1 = son(e);

	exp arg2 = bro(arg1);

	exp t, u, v;

	where qw;

	exp old_overflow_e = overflow_e;

	if (last (arg1)) {	/* there is only one argument */

	  coder(dest, stack, arg1);

	  return;

	};

	if (!optop(e))

          overflow_e = e;

	if (last(arg2) && is_o(name(arg1)) && !is_crc(arg1) &&

	   ((is_o(name(arg2)) && !is_crc(arg2)) ||

	     (name(arg2) == neg_tag &&

	       !is_crc(son(arg2)) &&

	       is_o(name(son(arg2)))))) {

	  /* just two arguments. */

	  addsub(sh(e), mw(arg2, 0), mw(arg1, 0), dest, e);

          overflow_e = old_overflow_e;

	  return;

	};

	/* need to take care about overlap between dest and args or to

	   avoid extra push. So use reg0. */

	t = arg1;

	qw.where_exp = copyexp(reg0.where_exp);

	sh(qw.where_exp) = sh(e);

	qw.where_off = 0;

	/* now look for argument which is not a possible 80386 operand */

	while (1) {

	  if ((!is_o(name(t)) || is_crc(t)) &&

	     (name(t)!= neg_tag || !is_o(name(son(t))) ||

	       is_crc(son(t))))

	    break;

	  if (last(t)) {

	    t = nilexp;

	    break;

	  };

	  t = bro(t);

	};

	if (t == nilexp && name(arg1) == neg_tag &&

	    name(arg2) == neg_tag)

	  t = arg1;

	if (t == nilexp) {	/* all arguments are possible 80386

				   operands */

	  t = bro(arg2);

	  if (name(arg1) == neg_tag)

	    addsub(sh(e), mw(arg1, 0), mw(arg2, 0),

		(t == e)? dest : qw, e);

	  else

	    addsub(sh(e), mw(arg2, 0), mw(arg1, 0),

		(t == e)? dest : qw, e);

	  if (t == e)

           {

             overflow_e = old_overflow_e;

	     return;

           };

	  while (!last(t)) {

	    u = bro(t);

	    addsub(sh(e), mw(t, 0), qw, qw, e);

	    t = u;

	  };

	  addsub(sh(e), mw(t, 0), qw, dest, e);

          overflow_e = old_overflow_e;

	  return;

	};

	coder (qw, stack, t);	/* encode the argument which is not a

				   possible 80386 operand */

	u = arg1;

	/* now encode the remaining operations */

	while (1) {

	  v = bro(u);

	  if (t != u) {

	    if (last(u) || (v == t && last(v)))

	      addsub(sh(e), mw(u, 0), qw, dest, e);

	    else

	      addsub(sh(e), mw(u, 0), qw, qw, e);

	  };

	  if (last(u))

	    break;

	  u = v;

	};

	retcell(qw.where_exp);

        cond1_set = 0;

        overflow_e = old_overflow_e;

	return;

      };

    case addptr_tag: {		/* use index operation */

	mova(mw(e, 0), dest);

	return;

      };

    case chvar_tag: {

	exp a = son(e);

	exp old_overflow_e = overflow_e;

        if (!optop(e))

          overflow_e = e;

	if (!is_o(name(a)) || is_crc(a)) {

				/* argument is not a possible 80386

				   operand, so evaluate it in reg0 */

	  if (inmem(dest) ||

		(shape_size(sh(a)) == 8 && bad_from_reg(dest)) ||

		shape_size(sh(a)) == 64) {

	    where qw;

	    qw.where_exp = copyexp(reg0.where_exp);

	    sh(qw.where_exp) = sh(a);

	    qw.where_off = 0;

	    coder(qw, stack, a);

	    change_var_check(sh(e), qw, dest);

	    overflow_e = old_overflow_e;

	    retcell(qw.where_exp);

            cond1_set = 0;

	    return;

	  };

	  coder(dest, stack, a);

	  if (name(sh(e)) > name(sh(a)))

	    change_var_sh(sh(e), sh(a), dest, dest);

	  overflow_e = old_overflow_e;

	  return;

	};

	change_var_check(sh(e), mw(a, 0), dest);

	overflow_e = old_overflow_e;

	return;

      };

    case minus_tag:

      {

	exp old_overflow_e = overflow_e;

        if (!optop(e))

          overflow_e = e;

	bop(sub, sh(e), bro(son(e)), son(e), dest, stack);

	overflow_e = old_overflow_e;

	return;

      };

    case subptr_tag:

    case minptr_tag:

    case make_stack_limit_tag:

      {

	bop(sub, sh(e), bro(son(e)), son(e), dest, stack);

	return;

      };

    case mult_tag:

      {

        if (!optop(e))

          {

	    exp old_overflow_e = overflow_e;

            overflow_e = e;

	    multop(multiply, e, dest, stack);

            overflow_e = old_overflow_e;

          }

        else

	  multop(mult, e, dest, stack);

	return;

      };

    case div2_tag:

      {

	exp old_overflow_e = overflow_e;

        if (errhandle(e))

          overflow_e = e;

	bop(div2, sh(e), bro(son(e)), son(e), dest, stack);

	overflow_e = old_overflow_e;

	return;

      };

    case div1_tag:

      {

	exp old_overflow_e = overflow_e;

        if (errhandle(e))

          overflow_e = e;

	bop(div1, sh(e), bro(son(e)), son(e), dest, stack);

	overflow_e = old_overflow_e;

	return;

      };

    case div0_tag:

      {

	exp old_overflow_e = overflow_e;

        if (errhandle(e))

          overflow_e = e;

	bop(div0, sh(e), bro(son(e)), son(e), dest, stack);

	overflow_e = old_overflow_e;

	return;

      };

    case neg_tag:

      {

	exp old_overflow_e = overflow_e;

        if (!optop(e))

          overflow_e = e;

	uop(negate, sh(e), son(e), dest, stack);

	overflow_e = old_overflow_e;

	return;

      };

    case shl_tag:

      {

	exp old_overflow_e = overflow_e;

	overflow_e = e;

        if (!optop(e))

          overflow_e = e;

	bop(shiftl, sh(e), bro(son(e)), son(e), dest, stack);

	overflow_e = old_overflow_e;

	return;

      };

    case shr_tag:

      {

	bop(shiftr, sh(e), bro(son(e)), son(e), dest, stack);

	return;

      };

    case rotl_tag:

      {

	bop(rotatel, sh(e), bro(son(e)), son(e), dest, stack);

	return;

      };

    case rotr_tag:

      {

	bop(rotater, sh(e), bro(son(e)), son(e), dest, stack);

	return;

      };

    case mod_tag:

      {

	exp old_overflow_e = overflow_e;

        if (errhandle(e))

          overflow_e = e;

	bop(mod, sh(e), bro(son(e)), son(e), dest, stack);

	overflow_e = old_overflow_e;

	return;

      };

    case rem2_tag:

      {

	exp old_overflow_e = overflow_e;

        if (errhandle(e))

          overflow_e = e;

	bop(rem2, sh(e), bro(son(e)), son(e), dest, stack);

	overflow_e = old_overflow_e;

	return;

      };

    case rem0_tag:

      {

	exp old_overflow_e = overflow_e;

        if (errhandle(e))

          overflow_e = e;

	bop(rem0, sh(e), bro(son(e)), son(e), dest, stack);

	overflow_e = old_overflow_e;

	return;

      };

    case round_tag:

      {

	shape s = sh(e);

	where d;

	d = dest;

	if (shape_size(s) < 32) {

	  s = slongsh;

	  if (inmem(dest))

	    d = reg0;

	}

        setup_fl_ovfl(e);

	switch (round_number(e)) {

	  case 0:

		uop(frnd0, s, son(e), d, stack);

		break;

	  case 1:

		uop(frnd1, s, son(e), d, stack);

		break;

	  case 2:

		uop(frnd2, s, son(e), d, stack);

		break;

	  case 3:

		uop(frnd3, s, son(e), d, stack);

		break;

	  case 4:

		uop(frnd4, s, son(e), d, stack);

		break;

	};

        test_fl_ovfl(e, d);

	if (name(s)!= name(sh(e))) {

	  exp old_overflow_e = overflow_e;

          if (!optop(e))

            overflow_e = e;

	  change_var_sh(sh(e), s, d, dest);

	  overflow_e = old_overflow_e;

	}

	return;

      };

    case fplus_tag:

      {

        setup_fl_ovfl(e);

	fl_multop(fplus_tag, sh(e), son(e), dest);

        test_fl_ovfl(e, dest);

	return;

      };

    case fmult_tag:

      {

        setup_fl_ovfl(e);

	fl_multop(fmult_tag, sh(e), son(e), dest);

        test_fl_ovfl(e, dest);

	return;

      };

    case fminus_tag:

      {

        setup_fl_ovfl(e);

	fl_binop(fminus_tag, sh(e), mw(bro(son(e)), 0),

	    mw(son(e), 0), dest, bro(son(e)));

        test_fl_ovfl(e, dest);

	return;

      };

    case fdiv_tag:

      {

        setup_fl_ovfl(e);

	fl_binop(fdiv_tag, sh(e), mw(bro(son(e)), 0),

	      mw(son(e), 0), dest, bro(son(e)));

        test_fl_ovfl(e, dest);

	return;

      };

    case fneg_tag: {

        setup_fl_ovfl(e);

	fl_neg(sh(e), mw(son(e), 0), dest);

        test_fl_ovfl(e, dest);

	return;

      };

    case fabs_tag: {

        setup_fl_ovfl(e);

	fl_abs(sh(e), mw(son(e), 0), dest);