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/*

    		 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/operand.c */

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

$Author: pwe $

$Date: 1998/02/18 11:22:05 $

$Revision: 1.2 $

$Log: operand.c,v $

 * Revision 1.2  1998/02/18  11:22:05  pwe

 * test corrections

 *

 * Revision 1.1.1.1  1998/01/17  15:55:52  release

 * First version to be checked into rolling release.

 *

 * Revision 1.12  1996/04/19  16:14:05  pwe

 * simplified use of global id = id, correcting linux call problem

 *

 * Revision 1.11  1995/08/30  16:06:50  pwe

 * prepare exception trapping

 *

 * Revision 1.10  1995/08/23  09:42:58  pwe

 * track fpu control word for trap etc

 *

 * Revision 1.9  1995/08/04  08:29:41  pwe

 * 4.0 general procs implemented

 *

 * Revision 1.8  1995/04/05  12:35:18  pwe

 * operator precedence in eq_where_exp

 *

 * Revision 1.7  1995/04/03  08:30:24  pwe

 * invalidate regs if overlap, eg if bitfield on byte boundaries

 *

 * Revision 1.6  1995/03/24  09:21:39  pwe

 * global proc renaming avoided for SCO

 *

 * Revision 1.5  1995/03/03  10:12:36  pwe

 * makeval is legal but arbitrary operand (for C)

 *

 * Revision 1.4  1995/02/24  16:11:12  pwe

 * dynamic offsets, including mixed bit/byte representations

 *

 * Revision 1.3  1995/02/21  11:47:59  pwe

 * Corrected move(offset) for movecont

 *

 * Revision 1.2  1995/01/30  12:56:36  pwe

 * Ownership -> PWE, tidy banners

 *

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

 * Initial revision

 *

 * Revision 1.1  1994/07/12  14:38:12  jmf

 * Initial revision

 *

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

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

                              operand.c

  operand outputs a 80386 operand, given a "where" and the number of

  bits the operand occupies.

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

#include "config.h"

#include "common_types.h"

#include "tags.h"

#include "basicread.h"

#include "expmacs.h"

#include "exp.h"

#include "shapemacs.h"

#include "flpt.h"

#include "coder.h"

#include "instr.h"

#include "out.h"

#include "check.h"

#include "codermacs.h"

#include "externs.h"

#include "install_fns.h"

#include "table_fns.h"

#include "flags.h"

#include "instr386.h"

#include "machine.h"

#include "localflags.h"

#include "assembler.h"

#include "messages_8.h"

#include "diag_fns.h"

#include "operand.h"

/* VARIABLES */

/* All variables initialised */

int  crt_proc_id;	/* init by cproc */

int  stack_dec;		/* init by cproc */

			/* current stack decrement */

exp const_list;		/* init by init_all */

			/* list of constants belonging to current

				   procedure */

/* PROCEDURES */

/* turns an exp and an offset (in bits)

   into a where */

where mw

    PROTO_N ( (e, off) )

    PROTO_T ( exp e X int off )

{

  where w;

  w.where_exp = e;

  w.where_off = off;

  return (w);

}

/* compares wheres for equality of operand.

   This is also used by equiv_reg to detect

   invalidity of register copy, in which case

   we need to detect overlaps, this case

   determined by 'overlap' */

int eq_where_exp

    PROTO_N ( (a, b, first, overlap) )

    PROTO_T ( exp a X exp b X int first X int overlap )

{

  unsigned char  na;

  unsigned char  nb;

rept:

  na = name(a);

  nb = name(b);

  if (a == b)

    return (1);

  if (na == nb) {		/* same kind of operation "equal names" */

    if (na == val_tag && !isbigval(a) && !isbigval(b))

      return (no (a) == no (b));

    if (na == ident_tag) {

      int good = son(a) != nilexp && son(b) != nilexp &&

          bro(son(a)) != nilexp && bro(son(b)) != nilexp;

      if (good) {

        exp bsa = bro(son(a));

        exp bsb = bro(son(b));

        if (name (bsa) == name_tag && son (bsa) == a &&

	    name (bsb) == name_tag && son (bsb) == b) {

	  a = son(a);

	  b = son(b);

	  first = 0;

	  goto rept;

        };

        if (name (bsa) == reff_tag &&

	    name (bsb) == reff_tag &&

	    (overlap ? (no (bsa) & -32) == (no (bsb) & -32) : no (bsa) == no (bsb)) &&

	    name (son (bsa)) == name_tag &&

	    son (son (bsa)) == a &&

	    name (son (bsb)) == name_tag &&

	    son (son (bsb)) == b) {

	  a = son(a);

	  b = son(b);

	  first = 0;

	  goto rept;

        };

      };

      if (isglob(a) || isglob(b))

        return 0;

      return (pt (a) == pt (b) &&

	      (overlap ? (no (a) & -32) == (no (b) & -32) : no (a) == no (b)));

    };

    if (na == name_tag) {

      if ((overlap ? (no (a) & -32) != (no (b) & -32) : no (a) != no (b)) ||

	  (isvar (son (a)) != isvar (son (b))))

	return (0);

      a = son(a);

      b = son(b);

      first = 0;

      goto rept;

    };

    if (na == cont_tag || na == ass_tag) {

      a = son(a);

      b = son(b);

      first = 0;

      goto rept;

    };

    if (na == field_tag || na == reff_tag) {

      if (overlap ? (no (a) & -32) != (no (b) & -32) : no (a) != no (b))

	return (0);

      a = son(a);

      b = son(b);

      first = 0;

      goto rept;

    };

    if (na == real_tag && name (sh (a)) == name (sh (b))) {

      flt fa, fb;

      int  i;

      int is_zero = 1;

      fa = flptnos[no (a)];

      fb = flptnos[no (b)];

      for (i = 0; i < MANT_SIZE && (fa.mant)[i] == (fb.mant)[i];

	  i++) {

	if ((fa.mant)[i] != 0)

	  is_zero = 0;

      };

      return (i == MANT_SIZE &&

	  (is_zero || (fa.exp == fb.exp &&

	      fa.sign == fb.sign)));

    };

    return (0);

  };				/* end equal names */

  if (na == name_tag && nb == ident_tag && first) {

    if (overlap ? (no (a) & -32) != 0 : no (a) != 0)

      return (0);

    a = son(a);

    first = 0;

    goto rept;

  };

  if (na == ident_tag && nb == name_tag && first) {

    if (overlap ? (no (b) & -32) != 0 : no (b) != 0)

      return (0);

    b = son(b);

    first = 0;

    goto rept;

  };

  if (na == cont_tag && name(son(a)) == name_tag &&

         isvar(son(son(a))) && nb == ident_tag && first) {

    if (overlap ? (no (son(a)) & -32) != 0 : no (son(a)) != 0)

      return (0);

    a = son(son(a));

    first = 0;

    goto rept;

  };

  if (na == ident_tag && nb == cont_tag && name(son(b)) == name_tag

            && isvar(son(son(b))) && first) {

    if (overlap ? (no (son(b)) & -32) != 0 : no (son(b)) != 0)

      return (0);

    b = son(b);

    first = 0;

    goto rept;

  };

  if ((na == cont_tag || na == ass_tag) &&

      name (son (a)) == name_tag &&

      isvar (son (son (a))) && nb == name_tag && !isvar (son (b))) {

    if (overlap ? (no (son(a)) & -32) != (no (b) & -32) : no (son(a)) != no (b))

      return (0);

    a = son (son (a));

    b = son (b);

    first = 0;

    goto rept;

  };

  if ((nb == cont_tag || nb == ass_tag) &&

      name (son (b)) == name_tag &&

      isvar (son (son (b))) && na == name_tag && !isvar (son (a))) {

    if (overlap ? (no (son(b)) & -32) != (no (a) & -32) : no (son(b)) != no (a))

      return (0);

    a = son (a);

    b = son (son (b));

    first = 0;

    goto rept;

  };

  if ((na == ass_tag && nb == cont_tag) ||

      (nb == ass_tag && na == cont_tag)) {

    a = son(a);

    b = son(b);

    first = 0;

    goto rept;

  };

  return (0);

}

/* compares wheres for equality of operand */

int eq_where

    PROTO_N ( (wa, wb) )

    PROTO_T ( where wa X where wb )

{

  exp a = wa.where_exp;

  exp b = wb.where_exp;

  if (a == nilexp || b == nilexp)

     return 0;

  if (wa.where_off != wb.where_off)

    return (0);

  return eq_where_exp (a, b, 1, 0);

}

/* find the first register in the register bit pattern r */

frr first_reg

    PROTO_N ( (r) )

    PROTO_T ( int r )

{

  frr t;

  t.regno = 1;

  t.fr_no = 0;

  if (r == 0)

    failer (BAD_REGISTER);

  else {

    while (!(t.regno & r)) {

      t.regno = t.regno << 1;

      ++t.fr_no;

    }

  };

  return (t);

}

/* output operand,  wh is a where Note

   that the pt field of a declaration now

   hold a code for the position of the

   value (eg. reg_pl for in a register,

   local_pl for relative to sp etc.). The

   no field hold the location, bit pattern

   for register, offset (in bits) for

   local etc. stack_dec hold the amount

   the stack is decremented from its

   position at the start of the procedure

   (ie the place where no is measured

   from). This is to allow for push

   operations. b is passed to extn to

   control whether a bracket is output

   (index instructions). addr is true if

   we need a literal address. */

void operand

    PROTO_N ( (le, wh, b, addr) )

    PROTO_T ( int le X where wh X int b X int addr )

{

  exp w = wh.where_exp;

  int  off = wh.where_off;

  unsigned char  n = name (w);

  if (n == val_tag && !isbigval(w)) {		/* integer constant */

    int  k = no (w) + off;

    if (name(sh(w)) == offsethd && al2(sh(w)) != 1)

      k = k / 8;

    int_operand (k, le);

    return;

  };

  if (n == ident_tag || n == labst_tag) {/* can only be dest */

    switch (ptno (w)) {

      case local_pl: {

	  rel_sp ((no (w) + off - stack_dec) / 8, b);

	  return;

	};

      case reg_pl: {

	  regn (no (w), off, w, le);

	  return;

	};

      default: {

	  failer (BAD_OPND);

	  return;

	};

    };

  };

  if (n == name_tag) {

    exp ident = son (w);

    int  noff = no (w) + off;

    int  ni = no (ident);

    if (isglob (ident)) {

      if (name (sh (w)) == prokhd)	/* special treatment for procedures */

        {

          const_extn (ident, noff);

          return;

        };

      if (isvar (ident))

	const_extn (ident, noff);

      else

	extn (ident, noff, b);

      return;

    };

    switch (ptno (ident)) {

      case local_pl: {		/* local so relative to stack pointer or fp */

	  rel_sp ((ni + noff - stack_dec) / 8, b);

	  return;

	};

      case callstack_pl: {	/* caller arg so relative to stack pointer */

	  rel_cp ((ni + noff - stack_dec) / 8, b);

	  return;

	};

      case par_pl: {		/* parameter so relative to fp */

	  rel_ap ((ni + noff + 32) / 8, b);

	  return;

	};

      case reg_pl: {		/* in a register */

	  regn (ni, noff, w, le);

	  return;

	};

      case ferr_pl: {		/* relative to fp, depending on push space */

	  rel_ap1 ((ni + noff) / 8, b);

	  return;

	};

      default: {		/* doesnt happen */

	  failer (BAD_OPND);

	  return;

	};

    };

  };

  if (n == cont_tag || n == ass_tag) {

    exp ref = son (w);

    unsigned char  s = name (ref);

    if (addr) {

      operand (le, mw (son (w), 0), b, 0);

      return;

    };

    if (s == name_tag) {	/* content of id */

      if (!isvar (son (ref))) {

	exp ident = son (ref);

	if (ptno (ident) != reg_pl && off != 0) {

	  failer (BAD_OPND);

	};

	if (isglob (ident)) {

	  if (name (sh (w)) != prokhd)

	    failer (BAD_OPND);

	  else

           {

	     if (PIC_code)

	       proc_extn (ident, no(ref));

             else

               extn (ident, no (ref), b);

           };

	  return;

	};

	switch (ptno (ident)) {

	  case reg_pl: {	/* indirect from register */

	      ind_reg (no (ident), no (ref), off, ref, b);

	      return;

	    };

	  default: {

	      failer (BAD_OPND);

	      return;

	    };

	};

      }

      else {			/* variable */

	exp ident = son (ref);

	int  noff = no (ref) + off;

	int  ni = no (ident);

	if (isglob (ident)) {

	  extn (ident, noff, b);

	  return;

	};

	switch (ptno (ident)) {

	  case local_pl: {

	      /* local so relative to stack pointer or fp */

	      rel_sp ((ni + noff - stack_dec) / 8, b);

	      return;

	    };

	  case callstack_pl: {

	      /* caller arg so relative to stack pointer */

	      rel_cp ((ni + noff - stack_dec) / 8, b);

	      return;

	    };

	  case par_pl: {	/* parameter so relative to fp */

	      rel_ap ((ni + noff + 32) / 8, b);

	      return;

	    };

	  case reg_pl: {	/* in a register */

	      regn (ni, noff, ref, le);

	      return;

	    };

	  default: {		/* doesnt happen */

	      failer (BAD_OPND);

	      return;

	    };

	};

      };

    };				/* end of cont(name) */

    if (s == cont_tag && name (son (ref)) == name_tag &&

	isvar (son (son (ref)))) {

      exp ident = son (son (ref));

      if (ptno (ident) != reg_pl && off != 0) {

	failer (BAD_OPND);

      };

      if (isglob (ident)) {

	if (name (sh (w)) != prokhd)

	  failer (BAD_OPND);

	else

	  extn (ident, no (son (ref)), b);

	return;

      };

      switch (ptno (ident)) {

	case reg_pl: {		/* indirect from register */

	    ind_reg (no (ident), no (son (ref)), off, ref, b);

	    return;

	  };

	default: {

	    failer (BAD_OPND);

	    return;

	  };

      };

    };				/* end of cont(cont(var)) */

    if (s == reff_tag) {

      exp et = son (ref);

      unsigned char  t = name (et);

      if (t == name_tag) {

	if (isglob (son (et))) {

	  extn (son (et), no (ref), b);

	  return;

	};

	switch (ptno (son (et))) {

	  case reg_pl: {

	      ind_reg (no (son (et)), no (et), (no (ref) + off), et, b);

	      return;

	    };

	  default: {

	      failer (BAD_OPND);

	      return;

	    };

	};

      };			/* end of cont(reff(name)) */

      if (t == cont_tag) {

	switch (ptno (son (son (et)))) {

	  case reg_pl: {

	      ind_reg (no (son (son (et))), no (son (et)),

		  (no (ref) + off), son (et), b);

	      return;

	    };

	  default: {

	      failer (BAD_OPND);

	      return;

	    };

	};

      };			/* end of cont(ref(cont())) */

      if (t == addptr_tag) {

	where new_w;

	new_w.where_exp = et;

	new_w.where_off = off + no (ref);

	operand (le, new_w, b, 0);

	return;

      };			/* end of cont(reff(addptr())) */

      failer (BAD_OPND);

    };				/* end of cont(reff()) */

    if (s == addptr_tag) {

      exp u = bro (son (ref));

      exp c = getexp (f_bottom, nilexp, 0, son (ref), nilexp,

	  0, 0, cont_tag);

      where wc, wu;

      wc.where_exp = c;

      wc.where_off = off;

      wu.where_exp = u;

      wu.where_off = 0;

      if (name (u) == name_tag || name (u) == cont_tag) {

	index_opnd (wc, wu, 1);

	return;

      };			/* end of cont(addptr(-, name)) */

      if (name (u) == offset_mult_tag) {

	int  k = no (bro (son (u)))/8;	/* cannot be bitfield */

	wu.where_exp = son (u);

	index_opnd (wc, wu, k);

	return;

      };			/* end of cont(addptr(-, mult)) */

    };				/* end of cont(addptr()) */

  };				/* end of cont */

  if (n == reff_tag) {

    exp se = son (w);

    unsigned char  s = name (se);

    if (s == name_tag) {

      if (isglob (son (se))) {

	extn (son (se), no (w), b);

	return;

      };

      switch (ptno (son (se))) {

	case reg_pl: {

	    ind_reg (no (son (se)), no (son (se)), no (w), se, b);

	    return;

	  };

	default: {

	    failer (BAD_OPND);

	    return;

	  };

      };

    };				/* end of reff(name)  */

    if (s == cont_tag) {

      if (isglob (son (son (se)))) {

	extn (son (son (se)), no (w), b);

	return;

      };

      switch (ptno (son (son (se)))) {

	case reg_pl: {

	    ind_reg (no (son (son (se))), no (son (se)),

		no (w), son (se), b);

	    return;

	  };

	default: {

	    failer (BAD_OPND);

	    return;

	  };

      };

    };				/* end of reff(cont()) */

    if (s == addptr_tag) {

      where ww;

      ww.where_exp = se;

      ww.where_off = off + no (w);

      operand (le, ww, b, 0);

      return;

    };				/* end of reff(addptr()) */

  };				/* end of reff() */

  if (n == addptr_tag) {

    exp u = bro (son (w));

    exp c = getexp (f_bottom, nilexp, 0, son (w), nilexp, 0, 0, cont_tag);

    where wc, wu;

    wc.where_exp = c;

    wc.where_off = off;

    wu.where_exp = u;

    wu.where_off = 0;

    if (name (u) == name_tag || name (u) == cont_tag) {

      index_opnd (wc, wu, 1);

      return;

    };				/* end of addptr(-, name)  */

    if (name (u) == offset_mult_tag) {

      int  k = no (bro (son (u)))/8;	/* cannot be bitfield */

      wu.where_exp = son (u);

      index_opnd (wc, wu, k);

      return;

    };				/* end of addptr(-, mult) */

  };				/* end of addptr() */

  if (n == real_tag || n == val_tag || n == string_tag ||

	n == proc_tag || n == general_proc_tag) {

    int  ln;

    if (off == 0 || addr) {

      ln = next_lab ();

      const_list = getexp (f_bottom, const_list, 0, w, nilexp, 0, ln, 0);

      const_intnl ((addr || n == proc_tag || n == general_proc_tag), ln, 0);

      return;

    };

    /* assumes this is only used just after using the first part of the

       constant */

    const_intnl (0, no (const_list), off);

    return;

  };

  if (n == res_tag) {

    const_intnl (0, no (w), off);

    return;

  };

  if (n == null_tag) {

    int_operand (no(w), le);

    return;

  };

  if (n == field_tag) {

    operand (le, mw (son (w), off + no (w)), b, addr);

    return;

  };

  if (n == make_lv_tag) {

    label_operand(w);

    return;

  };

  if (n == current_env_tag) {

    outbp();

    return;

  };

  if (n == env_offset_tag) {

    if (name(son(w))==0) {	/* must be caller arg with var_callees */

      int_operand(no(son(w))/8, le);

      return;

    }

    outs("$");

    envoff_operand(son(w), no(w));

    return;

  };

  if (n == env_size_tag) {

    outs("$");

    envsize_operand(son(son(w)));

    return;

  };

  if (n == local_free_all_tag) {

    ldisp();

    return;

  };

  if (n == clear_tag) {

	/* any legal operand will do! */

    if (name(sh(w)) >= shrealhd && name(sh(w)) <= doublehd) {

      outs("%st");

      return;

    }

    switch (shape_size(sh(w))) {

      case 8:

	outs("%al");

	return;

      case 16:

	outs("%ax");

	return;

      default:

	outs("%eax");

	return;

    };

  };

  failer (BAD_OPND);

  return;

}