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/*
                 Crown Copyright (c) 1996

    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.
*/
/*
                            VERSION INFORMATION
                            ===================

--------------------------------------------------------------------------
$Header: /u/g/release/CVSROOT/Source/src/installers/680x0/common/instr.c,v 1.1.1.1 1998/01/17 15:55:49 release Exp $
--------------------------------------------------------------------------
$Log: instr.c,v $
 * Revision 1.1.1.1  1998/01/17  15:55:49  release
 * First version to be checked into rolling release.
 *
Revision 1.4  1997/11/13 08:27:12  ma
All avs test passed (except add_to_ptr).

Revision 1.3  1997/11/09 14:10:04  ma
Added comment.

Revision 1.2  1997/10/29 10:22:18  ma
Replaced use_alloca with has_alloca.

Revision 1.1.1.1  1997/10/13 12:42:54  ma
First version.

Revision 1.6  1997/10/13 08:49:32  ma
Made all pl_tests for general proc & exception handling pass.

Revision 1.5  1997/09/25 06:45:09  ma
All general_proc tests passed

Revision 1.4  1997/06/18 12:04:54  ma
Merged with Input Baseline changes.

Revision 1.3  1997/06/18 10:09:34  ma
Checking in before merging with Input Baseline changes.

Revision 1.2  1997/04/20 11:30:29  ma
Introduced gcproc.c & general_proc.[ch].
Added cases for apply_general_proc next to apply_proc in all files.

Revision 1.1.1.1  1997/03/14 07:50:13  ma
Imported from DRA

 * Revision 1.1.1.1  1996/09/20  10:57:00  john
 *
 * Revision 1.3  1996/07/30  16:31:02  john
 * Removed offset conversion
 *
 * Revision 1.2  1996/07/05  14:20:49  john
 * Changes for spec 3.1
 *
 * Revision 1.1.1.1  1996/03/26  15:45:12  john
 *
 * Revision 1.3  94/02/21  15:59:15  15:59:15  ra (Robert Andrews)
 * Make a couple of integer literals into longs.
 *
 * Revision 1.2  93/11/19  16:21:50  16:21:50  ra (Robert Andrews)
 * Added proc_tag case.
 *
 * Revision 1.1  93/02/22  17:15:50  17:15:50  ra (Robert Andrews)
 * Initial revision
 *
--------------------------------------------------------------------------
*/


#include "config.h"
#include "common_types.h"
#include "exp.h"
#include "expmacs.h"
#include "install_fns.h"
#include "externs.h"
#include "shapemacs.h"
#include "tags.h"
#include "instrs.h"
#include "mach.h"
#include "mach_ins.h"
#include "mach_op.h"
#include "codex.h"
#include "evaluate.h"
#include "utility.h"
#include "where.h"
#include "coder.h"
#include "instr.h"
#include "translate.h"


/*
    FIND THE EXTERNAL NAME OF AN OPERAND

    The expression e, representing an external, is looked up in the main_globals
    table, and its external name is returned.
*/

static char *extname
    PROTO_N ( ( e ) )
    PROTO_T ( exp e )
{
    dec *d = brog ( e ) ;
#if 0
    if ( d->dec_u.dec_val.external_register ) {
        error ( "External registers not yet implemented" ) ;
        return ( "????" ) ;
    }
#endif
    return ( d->dec_u.dec_val.dec_id ) ;
}


/*
    MACROS

    These macros are used as convenient shorthands in operand.
*/

#define  make_ind( X, Y )       make_indirect ( reg ( X ), ( Y ) / 8 )
#define  make_ext( X, Y )       make_extern ( extname ( X ), ( Y ) / 8 )
#define  make_ext_ind( X, Y )   make_extern_ind ( extname ( X ), ( Y ) / 8 )


/*
    TRANSLATE AN INDEX OPERAND

    The operand corresponding to w1 indexed by w2 times sf is translated into
    a mach_op.
*/

static mach_op *index_opnd
    PROTO_N ( ( w1, w2, sf ) )
    PROTO_T ( where w1 X where w2 X int sf )
{
    mach_op *op1, *op2 ;
    if ( name ( w2.wh_exp ) != name_tag ) {
        error ( "Illegal index operand" ) ;
        return ( null ) ;
    }
    op1 = operand ( L32, w1 ) ;
    op2 = operand ( L32, w2 ) ;
    return ( make_index_op ( op1, op2, sf ) ) ;
}


/*
    ERROR MESSAGE

    In debugging mode a little extra information is always useful.
*/

#ifdef EBUG
static char *illegal_operand = "Illegal operand, case %d" ;
#else
static char *illegal_operand = "Illegal operand" ;
#endif


/*
    TRANSLATE A TDF OPERAND INTO A MACHINE OPERAND

    The value wh of size sz is converted into a mach_op.
*/

mach_op *operand
    PROTO_N ( ( sz, wh ) )
    PROTO_T ( long sz X where wh )
{
    long d ;
    mach_op *op ;
    exp w = wh.wh_exp ;
    long off = wh.wh_off ;

    switch ( name ( w ) ) {

        case val_tag : {
            long k = no ( w ) + off ;
            if ( is_offset ( w ) ) k /= 8 ;
            if ( sz == 8 ) k &= 0xff ;
            if ( sz == 16 ) k &= 0xffff ;
            return ( make_value ( k ) ) ;
        }

        case ident_tag :
        case labst_tag : {
            switch ( ptno ( w ) ) {
                case var_pl : {
                    d = no ( w ) - off ;
                    return ( make_rel_ap ( -( d / 8 ) ) ) ;
                }
#ifndef tdf3
                case par2_pl : {
                    d = no ( w ) + off ;
                    return ( make_rel_ap2 ( d / 8 ) ) ;
                }
                case par3_pl : {
                    d = no ( w ) + off ;
                    return ( make_rel_sp ( d / 8 ) ) ;
                }
#endif
                case par_pl : {
                    d = no ( w ) + off + 32 ;
                    return ( make_rel_ap ( d / 8 ) ) ;
                }
                case reg_pl : {
                    return ( make_register ( reg ( no ( w ) ) ) ) ;
                }
                default : {
                    error ( illegal_operand, 0 ) ;
                    return ( null ) ;
                }
            }
        }

        case name_tag : {
            exp id = son ( w ) ;
            long d1 = no ( w ) + off ;
            long d2 = no ( id ) ;

            if ( isglob ( id ) ) {
              if(name(sh(w)) == prokhd){
#if 1
                  if(( son ( id ) == nilexp ||
                      name ( son ( id ) ) == proc_tag ||
                        name(son(id)) == general_proc_tag) )
#endif
                    return ( make_ext ( id, d1 ) );

                }
                return ( make_ext_ind ( id, d1 ) ) ;
            }

            switch ( ptno ( id ) ) {
#ifndef tdf3
                case par2_pl : {
                    return ( make_rel_ap2 ( ( d1 + d2  ) / 8 ) ) ;
                }
                case par3_pl : {
                    return ( make_rel_sp ( ( d1 + d2  ) / 8 ) ) ;
                }
#endif

                case par_pl : {
                    return ( make_rel_ap ( ( d1 + d2 + 32 ) / 8 ) ) ;
                }
                case var_pl : {
                    return ( make_rel_ap ( ( d1 - d2 ) / 8 ) ) ;
                }
                case reg_pl : {
                    return ( make_register ( reg ( d2 ) ) ) ;
                }
                default : {
                    error ( illegal_operand, 1 ) ;
                    return ( null ) ;
                }
            }
        }

        case cont_tag :
        case ass_tag : {
            exp r = son ( w ) ;
            switch ( name ( r ) ) {

                case name_tag : {
                    exp id = son ( r ) ;
                    if ( !isvar ( id ) ) {
                        if ( isglob ( id ) ) {
                            int ra ;
                            if ( name ( sh ( w ) ) == prokhd ) {
                                if ( off ) error ( illegal_operand, 2 ) ;
                                return ( make_ext_ind ( id, no ( r ) ) ) ;
                            }
                            op = make_ext_ind ( id, off ) ;
                            ra = tmp_reg ( m_movl, op ) ;
                            return ( make_indirect ( ra, no ( r ) / 8 ) ) ;
                        }
                        switch ( ptno ( id ) ) {
                            case par_pl : {
                                d = no ( id ) + no ( r ) + 32 ;
                                op = make_ind_rel_ap ( d / 8, off / 8 ) ;
                                return ( op ) ;
                            }
#ifndef tdf3
                            case par2_pl : {
                                d = no ( id ) + no ( r ) ;
                                op = make_ind_rel_ap2 ( d / 8, off / 8 ) ;
                                return ( op ) ;
                            }
                            case par3_pl : {
                                d = no ( id ) + no ( r ) ;
                                op = make_ind_rel_ap3 ( d / 8, off / 8 ) ;
                                return ( op ) ;
                            }
#endif
                            case var_pl : {
                                d = -( no ( id ) ) + no ( r ) ;
                                op = make_ind_rel_ap ( d / 8, off / 8 ) ;
                                return ( op ) ;
                            }
                            case reg_pl : {
                                return ( make_ind ( no ( id ), off ) ) ;
                            }
                            default : {
                                error ( illegal_operand, 4 ) ;
                                return ( null ) ;
                            }
                        }
                    } else {
                        where new_w ;
                        new_w.wh_exp = r ;
                        new_w.wh_off = off ;
                        return ( operand ( sz, new_w ) ) ;
                    }
                }

                case cont_tag : {
                    exp rr = son ( r ) ;
                    int roff = 0;
                    if (name (rr) == reff_tag){
                      rr = son(rr);
                      roff = no(rr);
                    }
                    switch ( name ( rr ) ) {

                        case name_tag : {
                            exp id = son ( rr ) ;
#if 0
                            if ( !isvar ( id ) ) {
                                error ( illegal_operand, 5 ) ;
                                return ( null ) ;
                            }
#endif
                            if ( isglob ( id ) ) {
                                int ra ;
                                op = make_ext_ind ( id, no ( rr ) ) ;
                                ra = tmp_reg ( m_movl, op ) ;
                                return ( make_indirect ( ra, off / 8 ) ) ;
                            }
                            switch ( ptno ( id ) ) {
                                case par_pl : {
                                    d = no ( id ) + no ( rr ) + 32 + roff ;
                                    op = make_ind_rel_ap ( d / 8, off / 8 ) ;
                                    return ( op ) ;
                                }
#ifndef tdf3
                                case par2_pl : {
                                    d = no ( id ) + no ( rr ) ;
                                    op = make_ind_rel_ap2 ( d / 8, off / 8 ) ;
                                    return ( op ) ;
                                }
                                case par3_pl : {
                                    d = no ( id ) + no ( rr ) ;
                                    op = make_ind_rel_ap3 ( d / 8, off / 8 ) ;
                                    return ( op ) ;
                                }
#endif
                                case var_pl : {
                                    d = -( no ( id ) ) + no ( rr ) + roff ;
                                    op = make_ind_rel_ap ( d / 8, off / 8 ) ;
                                    return ( op ) ;
                                }
                                case reg_pl : {
                                    return ( make_ind ( no ( id ), off ) ) ;
                                }
                                default : {
                                    error ( illegal_operand, 6 ) ;
                                    return ( null ) ;
                                }
                            }
                        }

                        default : {
                            error ( illegal_operand, 7 ) ;
                            return ( null ) ;
                        }
                    }
                }

                case reff_tag : {
                    exp rr = son ( r ) ;
                    switch ( name ( rr ) ) {

                        case name_tag : {
                            exp id = son ( rr ) ;
                            if ( isglob ( id ) ) {
                                int ra ;
                                op = make_ext_ind ( id, 0 ) ;
                                ra = tmp_reg ( m_movl, op ) ;
                                return ( make_indirect ( ra, no ( r ) / 8 ) ) ;
                            }
                            switch ( ptno ( id ) ) {
                                case reg_pl : {
                                    d = no ( r ) + off ;
                                    return ( make_ind ( no ( id ), d ) ) ;
                                }
                                case par2_pl:
                                case par3_pl:
                                case par_pl : {
                                    int ra ;
                                    where new_w ;
                                    new_w.wh_exp = id ;
                                    new_w.wh_off = 0 ;
                                    op = operand ( L32, new_w ) ;
                                    ra = tmp_reg ( m_movl, op ) ;
                                    d = no ( r ) + off ;
                                    return ( make_indirect ( ra, d / 8 ) ) ;
                                }
                                case var_pl : {
                                    int ra ;
                                    where new_w ;
                                    new_w.wh_exp = id ;
                                    new_w.wh_off = 0 ;
                                    op = operand ( L32, new_w ) ;
                                    ra = tmp_reg ( m_movl, op ) ;
                                    d = no ( r ) + off ;
                                    return ( make_indirect ( ra, d / 8 ) ) ;
                                }
                                default : {
                                    error ( illegal_operand, 8 ) ;
                                    return ( null ) ;
                                }
                            }
                        }

                        case cont_tag : {
                            exp rrr = son ( rr ) ;
                            exp id = son ( rrr ) ;
                            if ( ptno ( id ) == reg_pl ) {
                                d = no ( r ) + off ;
                                return ( make_ind ( no ( id ), d ) ) ;
                            }
                            if ( ptno ( id ) == var_pl ) {
                                int ra ;
                                where new_w ;
                                new_w.wh_exp = id ;
                                new_w.wh_off = 0 ;
                                op = operand ( L32, new_w ) ;
                                ra = tmp_reg ( m_movl, op ) ;
                                d = no ( r ) + off ;
                                return ( make_indirect ( ra, d / 8 ) ) ;
                            }
                            error ( illegal_operand, 9 ) ;
                            return ( null ) ;
                        }

                        case addptr_tag : {
                            where new_w ;
                            new_w.wh_exp = rr ;
                            new_w.wh_off = no ( r ) + off ;
                            return ( operand ( sz, new_w ) ) ;
                        }

                        default : {
                            error ( illegal_operand, 10 ) ;
                            return ( null ) ;
                        }
                    }
                }

                case addptr_tag : {
                    where wb, wc ;
                    exp rr = son ( r ) ;
                    exp eb = bro ( rr ) ;
                    exp ec = simple_exp ( cont_tag ) ;
                    son ( ec ) = rr ;
                    wb.wh_exp = eb ;
                    wb.wh_off = 0 ;
                    wc.wh_exp = ec ;
                    wc.wh_off = off ;
                    switch ( name ( eb ) ) {

                        case name_tag :
                        case cont_tag : {
                            return ( index_opnd ( wc, wb, 1 ) ) ;
                        }

                        case offset_mult_tag : {
                            long k = no ( bro ( son ( eb ) ) ) / 8 ;
                            if ( sz == 8 * k ) {
                                wb.wh_exp = son ( eb ) ;
                                wb.wh_off = 0 ;
                                return ( index_opnd ( wc, wb, ( int ) k ) ) ;
                            }
                            error ( illegal_operand, 11 ) ;
                            return ( null ) ;
                        }

                        default : {
                            error ( illegal_operand, 12 ) ;
                            return ( null ) ;
                        }
                    }
                }

                default : {
                    error ( illegal_operand, 14 ) ;
                    return ( null ) ;
                }
            }
        }

        case dummy_tag : {
            exp r = son ( w ) ;
            switch ( name ( r ) ) {

                case ident_tag : {
                    /* This is used by m_lea */
                    switch ( ptno ( r ) ) {
                        case reg_pl : {
                            return ( make_ind ( no ( r ), no ( w ) ) ) ;
                        }
                        case var_pl : {
                            int ra ;
                            where new_w ;
                            new_w.wh_exp = r ;
                            new_w.wh_off = 0 ;
                            op = operand ( L32, new_w ) ;
                            ra = tmp_reg ( m_movl, op ) ;
                            d = no ( w ) ;
                            return ( make_indirect ( ra, d / 8 ) ) ;
                        }
                        default : {
                            error ( illegal_operand, 15 ) ;
                            return ( null ) ;
                        }
                    }
                }

                case name_tag : {
                    exp id = son ( r ) ;
                    if ( isglob ( id ) ) {
                        return ( make_ext_ind ( id, no ( w ) ) ) ;
                    }
                    switch ( ptno ( id ) ) {
                        case reg_pl : {
                            return ( make_ind ( no ( id ), no ( w ) ) ) ;
                        }
                        case var_pl : {
                            int ra ;
                            where new_w ;
                            new_w.wh_exp = id ;
                            new_w.wh_off = 0 ;
                            op = operand ( L32, new_w ) ;
                            ra = tmp_reg ( m_movl, op ) ;
                            d = no ( w ) ;
                            return ( make_indirect ( ra, d / 8 ) ) ;
                        }
                        default : {
                            error ( illegal_operand, 16 ) ;
                            return ( null ) ;
                        }
                    }
                }

                case cont_tag :
                case ass_tag : {
                    exp rr = son ( r ) ;
                    exp id = son ( rr ) ;
                    if ( isglob ( id ) ) {
                        return ( make_ext_ind ( id, no ( w ) ) ) ;
                    }
                    switch ( ptno ( id ) ) {
                        case reg_pl : {
                            return ( make_ind ( no ( id ), no ( w ) ) ) ;
                        }
                        case var_pl : {
                            int ra ;
                            where new_w ;
                            new_w.wh_exp = id ;
                            new_w.wh_off = 0 ;
                            op = operand ( L32, new_w ) ;
                            ra = tmp_reg ( m_movl, op ) ;
                            d = no ( w ) ;
                            return ( make_indirect ( ra, d / 8 ) ) ;
                        }
                        default : {
                            error ( illegal_operand, 17 ) ;
                            return ( null ) ;
                        }
                    }
                }

                case addptr_tag : {
                    where new_w ;
                    new_w.wh_exp = r ;
                    new_w.wh_off = no ( w ) + off ;
                    return ( operand ( sz, new_w ) ) ;
                }

                default : {
                    error ( illegal_operand, 18 ) ;
                    return ( null ) ;
                }
            }
        }

        case reff_tag : {
            exp r = son ( w ) ;
            switch ( name ( r ) ) {

                case name_tag : {
                    exp id = son ( r ) ;
                    if ( isglob ( id ) ) {
                        return ( make_ext ( id, no ( w ) ) ) ;
                    }
                    switch ( ptno ( id ) ) {
                        case reg_pl : {
                            if ( no ( w ) ) {
                                int ra = reg ( no ( id ) ) ;
                                if ( is_dreg ( ra ) ) {
                                    op = make_register ( ra ) ;
                                    ra = tmp_reg ( m_movl, op ) ;
                                    add_to_reg ( ra, no ( w ) / 8 ) ;
                                } else {
                                    op = make_indirect ( ra, no ( w ) / 8 ) ;
                                    ra = tmp_reg ( m_lea, op ) ;
                                }
                                return ( make_register ( ra ) ) ;
                            }
                            d = no ( id ) ;
                            return ( make_register ( reg ( d ) ) ) ;
                        }
                        default : {
                            error ( illegal_operand, 19 ) ;
                            return ( null ) ;
                        }
                    }
                }

                case cont_tag :
                case ass_tag : {
                    exp rr = son ( r ) ;
                    exp id = son ( rr ) ;
                    if ( isglob ( id ) ) {
                        if ( no ( w ) ) {
                            int ra ;
                            op = make_ext_ind ( id, 0 ) ;
                            ra = tmp_reg ( m_movl, op ) ;
                            add_to_reg ( ra, no ( w ) / 8 ) ;
                            return ( make_register ( ra ) ) ;
                        }
                        return ( make_ext_ind ( id, 0 ) ) ;
                    }
                    switch ( ptno ( id ) ) {
                        case reg_pl : {
                            debug_warning ( "reff - untested case" ) ;
                            return ( make_ind ( no ( id ), no ( w ) ) ) ;
                        }
                        case var_pl : {
                            int ra ;
                            where new_w ;
                            new_w.wh_exp = id ;
                            new_w.wh_off = 0 ;
                            op = operand ( L32, new_w ) ;
                            ra = tmp_reg ( m_movl, op ) ;
                            if ( no ( w ) ) add_to_reg ( ra, no ( w ) / 8 ) ;
                            return ( make_register ( ra ) ) ;
                        }
                        default : {
                            error ( illegal_operand, 20 ) ;
                            return ( null ) ;
                        }
                    }
                }

                case addptr_tag : {
                    where new_w ;
                    debug_warning ( "reff - untested case" ) ;
                    new_w.wh_exp = r ;
                    new_w.wh_off = 0 ;
                    return ( operand ( sz, new_w ) ) ;
                }

                default : {
                    error ( illegal_operand, 21 ) ;
                    return ( null ) ;
                }
            }
        }

        case addptr_tag : {
            where wb, wc ;
            exp r = son ( w ) ;
            exp eb = bro ( r ) ;
            exp ec = simple_exp ( cont_tag ) ;
            son ( ec ) = r ;
            wb.wh_exp = eb ;
            wb.wh_off = 0 ;
            wc.wh_exp = ec ;
            wc.wh_off = off ;
            switch ( name ( eb ) ) {

                case name_tag :
                case cont_tag : {
                    return ( index_opnd ( wc, wb, 1 ) ) ;
                }

                case offset_mult_tag : {
                    long k = no ( bro ( son ( eb ) ) ) / 8 ;
                    wb.wh_exp = son ( eb ) ;
                    wb.wh_off = 0 ;
                    return ( index_opnd ( wc, wb, ( int ) k ) ) ;
                }

                default : {
                    error ( illegal_operand, 22 ) ;
                    return ( null ) ;
                }
            }
        }
        case general_proc_tag:

        case proc_tag : {
            long lb = next_lab () ;
            make_constant ( lb, w ) ;
            return ( make_lab ( lb, 0 ) ) ;
        }

        case real_tag :
        case string_tag : {
            long lb ;
            if ( off == 0 ) {
                lb = next_lab () ;
                make_constant ( lb, w ) ;
                return ( make_lab_ind ( lb, 0 ) ) ;
            }
            debug_warning ( "Offset from label" ) ;
            return ( make_lab_ind ( no ( const_list ) + 1, off / 8 ) ) ;
        }

        case res_tag : {
            return ( make_lab_ind ( no ( w ), 0 ) ) ;
        }

        case null_tag : {
            return ( make_value ( 0 ) ) ;
        }
#ifndef tdf3
        case apply_general_tag :
        case tail_call_tag :
#endif
        case apply_tag : {
            return ( make_dec_sp () ) ;
        }

        case field_tag : {
            where new_w ;
            new_w.wh_exp = son ( w ) ;
            new_w.wh_off = no ( w ) + off ;
            return ( operand ( sz, new_w ) ) ;
        }

        case current_env_tag : {
            return ( make_register ( REG_AP ) ) ;
        }

#ifndef tdf3
        case env_size_tag : {
           dec* dp = brog( son( son( w ) ) ) ;
           return  make_lab ( (long) dp, 0 ) ;
        }

        case env_offset_tag : {
           exp ident_exp = son ( w ) ;
           return  make_lab ( (long) ident_exp, 0 ) ;
        }
#else
        case env_offset_tag : {
            exp id = son ( w ) ;
            switch ( ptno ( id ) ) {
                case var_pl : {
                    d = no ( id ) - off ;
                    return ( make_value ( -( d / 8 ) ) ) ;
                }

                case par2_pl :  {
                    d = no ( id ) + off ;
                    return ( make_value ( d / 8 ) ) ;
                }
                case par3_pl :

                case par_pl : {
                    d = no ( id ) + off + 32 ;
                    if(used_stack){
                      d += 32;
                    }
                    return ( make_value ( d / 8 ) ) ;
                }
            }
            error ( illegal_operand, 23 ) ;
            return ( null ) ;
        }
#endif
        case make_lv_tag : {
            return ( make_lab ( ptno ( pt ( son ( pt ( w ) ) ) ), 0 ) ) ;
        }

        case local_free_all_tag : {
            return ( make_special_data ( "PA" ) ) ;
        }

        case internal_tag : {
            return ( make_lab_ind ( no ( w ), off / 8 ) ) ;
        }

        default : {
            error ( illegal_operand, 24 ) ;
            return ( null ) ;
        }
    }
}


/*
    FIND WHICH REGISTERS ARE CHANGED IN AN OPERAND

    This routine returns the bitmask of all the registers changed in the
    operand op.  c is true to indicate that the operand is being assigned
    to.  If c is false, the only way op can change a register is if it is
    a pre-decrement or post-increment.
*/

bitpattern regs_changed
    PROTO_N ( ( op, c ) )
    PROTO_T ( mach_op *op X int c )
{
    int t = op->type ;
    if ( t == MACH_DEC || t == MACH_INC ) return ( regmsk ( op->def.num ) ) ;
    if ( !c ) return ( 0 ) ;
    if ( t == MACH_REG ) return ( regmsk ( op->def.num ) ) ;
    if ( t == MACH_RPAIR ) {
        return ( regmsk ( op->def.num ) | regmsk ( op->plus->def.num ) ) ;
    }
    return ( 0 ) ;
}


/*
    OUTPUT AN INSTRUCTION WITH NO OPERANDS

    The instruction instr is created.
*/

void ins0
    PROTO_N ( ( instr ) )
    PROTO_T ( int instr )
{
    make_instr ( instr, null, null, 0 ) ;
    return ;
}


/*
    OUTPUT AN INSTRUCTION WITH ONE OPERAND

    The instruction instr with a single operand, a, of size asz is created.
    a_changed is true to indicate that a is assigned to.
*/

void ins1
    PROTO_N ( ( instr, asz, a, a_changed ) )
    PROTO_T ( int instr X long asz X where a X int a_changed )
{
    mach_op *op = operand ( asz, a ) ;
    bitpattern ch = regs_changed ( op, a_changed ) ;
    make_instr ( instr, op, null, ch ) ;
    return ;
}


/*
    OUTPUT AN INSTRUCTION WITH TWO OPERANDS

    The instruction instr with a two operands, a of size asz and b of size bsz,
    is created.  b_changed is true to indicate that b is assigned to.
*/

void ins2
    PROTO_N ( ( instr, asz, bsz, a, b, b_changed ) )
    PROTO_T ( int instr X long asz X long bsz X where a X where b X int b_changed )
{
    bitpattern ch ;
    mach_op *opa = operand ( asz, a ) ;
    mach_op *opb = operand ( bsz, b ) ;
    ch = ( regs_changed ( opa, 0 ) | regs_changed ( opb, b_changed ) ) ;
    make_instr ( instr, opa, opb, ch ) ;
    return ;
}


/*
    OUTPUT AN INSTRUCTION WITH TWO OPERANDS, ONE A CONSTANT

    The instruction instr with a two operands, a constant c and a of size asz,
    is created.  a_changed is true to indicate that a is assigned to.
*/

void ins2n
    PROTO_N ( ( instr, c, asz, a, a_changed ) )
    PROTO_T ( int instr X long c X long asz X where a X int a_changed )
{
    mach_op *opc = make_value ( c ) ;
    mach_op *opa = operand ( asz, a ) ;
    bitpattern ch = regs_changed ( opa, a_changed ) ;
    make_instr ( instr, opc, opa, ch ) ;
    return ;
}


/*
    OUTPUT AN INSTRUCTION WITH TWO OPERANDS, ONE A HEX CONSTANT

    The instruction instr with a two operands, a constant c and a of size asz,
    is created.  a_changed is true to indicate that a is assigned to.  This
    routine only differs from ins2n in that the constant will be output in
    hex rather than decimal.
*/

void ins2h
    PROTO_N ( ( instr, c, asz, a, a_changed ) )
    PROTO_T ( int instr X long c X long asz X where a X int a_changed )
{
    mach_op *opc = make_hex_value ( c ) ;
    mach_op *opa = operand ( asz, a ) ;
    bitpattern ch = regs_changed ( opa, a_changed ) ;
    make_instr ( instr, opc, opa, ch ) ;
    return ;
}

void save_stack
    PROTO_Z ()
{
  if (extra_stack || stack_dec)
    error ("unclean stack");
  make_comment("Save stack pointer");
  ins2 (m_movl, 32, 32, SP, firstlocal, 1);
}

void restore_stack
    PROTO_Z ()
{
  if (extra_stack || stack_dec)
    error ("unclean stack");
  make_comment("Restore stack pointer");
  ins2 (m_movl, 32, 32, firstlocal, SP, 1);
}