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general_proc.c

/*
             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/general_proc.c,v 1.1.1.1 1998/01/17 15:55:49 release Exp $
--------------------------------------------------------------------------
$Log: general_proc.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  1997/11/09 14:08:39  ma
Added preseve stack.

Revision 1.3  1997/10/29 10:22:14  ma
Replaced use_alloca with has_alloca.

Revision 1.2  1997/10/17 12:13:57  ma
Cleaned up.

Revision 1.1.1.1  1997/10/13 12:42:52  ma
First version.

Revision 1.6  1997/10/13 11:43:36  ma
Declared scan2.h

Revision 1.5  1997/10/13 08:49:29  ma
Made all pl_tests for general proc & exception handling pass.

Revision 1.4  1997/09/25 06:45:05  ma
All general_proc tests passed

Revision 1.3  1997/06/24 10:56:02  ma
Added changes for "Plumhall Patch"

Revision 1.2  1997/06/18 10:09:31  ma
Checking in before merging with Input Baseline changes.

--------------------------------------------------------------------------
*/


#include "config.h"
#include <limits.h>
#include "common_types.h"
#include "check.h"
#include "exp.h"
#include "expmacs.h"
#include "flags.h"
#include "shapemacs.h"
#include "externs.h"
#include "install_fns.h"
#include "spec.h"
#include "mach.h"
#include "where.h"
#include "tags.h"
#include "codec.h"
#include "coder.h"
#include "operations.h"
#include "ops_shared.h"
#include "mach_ins.h"
#include "mach_op.h"
#include "instr.h"
#include "codex.h"
#include "output.h"
#include "instrs.h"
#include "peephole.h"
#include "szs_als.h"
#include "tests.h"
#include "utility.h"
#include "weights.h"
#include "translate.h"
#include "general_proc.h"
#include "68k_globals.h"
#include "installglob.h"
#include "special_exps.h"

/* externals */

void scan2 PROTO_S ( ( bool sto, exp to, exp e ) ) ;
extern bool just_ret ;
extern mach_ins *prologue_ins ;

static void code_postlude PROTO_S ((exp postlude, exp callers, ash stack, long post_offset)) ;
static bool test_push_args PROTO_S ((exp args, ash* args_size )) ;
static void push_args PROTO_S ((where w, ash stack, exp args )) ;
static void place_arguments PROTO_S ((exp args, ash stack, long start )) ;

/************************************************************************
    GCPROC

    This routine encodes a procedure call.  The procedure is named pname
    with oname as an alternative (used with diagnostics).  The actual
    body of the procedure is p.
 ************************************************************************/

/* coder.c & codex.c */
extern ast add_shape_to_stack PROTO_S ((ash stack, shape s ));
extern void prologue PROTO_S ((void));
extern void out_profile PROTO_S (( bool save_a1 ));
extern int do_peephole ;
extern int do_pic ;

void gcproc
    PROTO_N ( ( p, pname, cname, is_ext, reg_res, di) )
    PROTO_T ( exp p X char *pname X long cname X int is_ext X int reg_res X diag_global *di )
{
  exp t ;
  ash stack ;
  ash param_pos ;

  mach_op *op1, *op2 ;
  static long crt_proc_no = 0 ;

  bool has_callers = 0;
  bool has_checkstack = 0;
  bool uses_callers_pointer = 0;
  cur_proc_callees_size = 0;

  /* find out if the call has tail_call or same_callees constructs */
  cur_proc_has_tail_call = 0;
  cur_proc_use_same_callees = 0;
  scan2(1, p, p);
  comp_weights ( p ) ;

  /* Set up flags, register masks, stack etc. */
  has_alloca = proc_has_alloca(p);
  must_use_bp = has_alloca || proc_has_lv(p) || proc_uses_crt_env (p) ;
  bigregs = 0 ;
  crt_ret_lab = next_lab () ;
  extra_stack = 0 ;
  have_cond = 0 ;
  max_stack = 0 ;
  no_calls = 0 ;
  regsinproc = 0 ;
  regsinuse = 0 ;
  reuseables = 0 ;
  regsindec = 0 ;
  stack = 0 ;
  special_no = crt_proc_no++ ;
  stack_dec = 0 ;
  stack_size = 0 ;
  used_ldisp = 0 ;
  used_stack = do_profile || diagnose || must_use_bp ;

  /* Mark procedure body */
  ptno ( p ) = par_pl ;
  no ( p ) = 0 ;

  /* Mark procedure parameters */
  param_pos = 0 ;

  /* the callees are encoded first. Scan to first callee if any */

  t = son ( p ) ;
  while ( name ( t ) == ident_tag && isparam ( t ) &&
          name ( son ( t ) ) != formal_callee_tag ) {
    t = bro(son(t)) ;
    has_callers = 1 ;
  }

  cur_proc_has_vcallees = proc_has_vcallees(p) ;
  uses_callers_pointer = cur_proc_has_vcallees && has_callers ;

  if (uses_callers_pointer) {
    /* ok callers are accessed by use of a5 */
    regsinproc |= regmsk ( REG_A5 ) ;
    regsinuse  |= regmsk ( REG_A5 ) ;
  }


  /* do we have any callees? */
  if (name(t) == ident_tag && name(son(t)) == formal_callee_tag) {
    while(name(t) == ident_tag && name(son(t)) == formal_callee_tag) {
      ast a ;
      a = add_shape_to_stack ( param_pos, sh ( son ( t ) ) ) ;
      no ( t ) = a.astoff + a.astadj + (cur_proc_has_vcallees ? 4*8 : 0);
      param_pos = a.astash ;
      ptno ( t ) = par_pl ;

      make_visible( t ) ;

      t = bro ( son ( t ) ) ;
    }
    cur_proc_callees_size = param_pos ;
  }


  /* encode the caller parameters */
  {
    exp caller = son ( p ) ;
    int location_id = par_pl ;
    if ( uses_callers_pointer ) {
      location_id = par2_pl ;
      param_pos = 0 ;
    }
    while (name(caller) == ident_tag && isparam (caller) &&
           name(son(caller)) != formal_callee_tag ) {

      ast a;
      a = add_shape_to_stack ( param_pos, sh ( son ( caller ) ) ) ;
      ptno ( caller ) = location_id ;
      no ( caller ) = a.astoff + a.astadj ;
      param_pos = a.astash ;

      make_visible( caller ) ;

      caller = bro ( son ( caller ) ) ;
    }
  }

  /* calculate callers size */
  cur_proc_callers_size = param_pos ;
  if ( ! uses_callers_pointer )
  cur_proc_callers_size -= cur_proc_callees_size ;

  /* Output procedure name(s) */
  area ( ptext ) ;
  make_instr ( m_as_align4, null, null, 0 ) ;
  if ( is_ext && pname ) {
     if ( strcmp ( pname, "_cmppt" ) == 0 ) {
        /* Hack to get alignments right */
      make_instr ( m_nop, null, null, 0 ) ;
      make_instr ( m_nop, null, null, 0 ) ;
    }
    op1 = make_extern_data ( pname, 0 ) ;
    make_instr ( m_as_global, op1, null, 0 ) ;
  }
  if ( cname == -1 ) {
    make_external_label ( pname ) ;
  } else {
     make_label ( cname ) ;
  }

  if (! strcmp (pname, "_main")) {
     make_comment("Do Dynamic Initialization");
     op1 = make_extern_ind("___TDF_main",0);
     make_instr(m_call,op1,null,0);
  }

  /* Output profiling information if required */
  if ( do_profile ) {
    out_profile ( !reg_res ) ;
    used_stack = 1 ;
  }

  if ( proc_has_checkstack(p) ) {
     /* check that there is room for env_size(<this proc>) */
     /* since callers, callees & return address are pushed */
     /* we only check for the rest */
     long already_allocated = cur_proc_callers_size + cur_proc_callees_size + 32 ;
     where w;
     w = mw (get_env_size(cur_proc_dec), - already_allocated);
     checkalloc_stack (w, 0);
     has_checkstack = 1 ;
  }


  /* Set up procedure prologue */
  prologue () ;

  /* Diagnostics for start of procedure */
#if have_diagnostics
  if ( di ) xdb_diag_proc_begin ( di, p, pname, cname, is_ext ) ;
#endif

  /* Allow for procedures which return compound results */
  if ( !reg_res ) {
    /* Save A1 on the stack */
    ast newstack ;
    newstack = add_shape_to_stack ( stack, slongsh ) ;
    stack = newstack.astash ;
    max_stack = 32 ;
    used_stack = 1 ;
    op1 = make_register ( REG_A1 ) ;
    op2 = make_indirect ( REG_AP, -4 ) ;
    make_instr ( m_movl, op1, op2, 0 ) ;
  }
  need_preserve_stack = 0;

  if (proc_uses_crt_env(p) && proc_has_lv(p) && has_alloca) {
     need_preserve_stack = 1 ;
     stack += 32 ;
     max_stack += 32 ;
     save_stack () ;
  };


  /* Encode the procedure body */
#if have_diagnostics
  if ( diagnose ) {
    dnt_begin () ;
    coder ( zero, stack, t ) ;
    dnt_end () ;
  } else
#endif
    coder ( zero, stack, t ) ;

  /* Output the procedure epilogue */
  general_epilogue (uses_callers_pointer, has_checkstack) ;

  /* Apply peephole optimizations and return */
  if ( do_peephole ) peephole () ;

  /* Diagnostics for end of procedure */
#if have_diagnostics
  if ( di ) xdb_diag_proc_end ( di ) ;
#endif

  return  ;
}


/************************************************************************
  restore_regs_subsribers is used by restore_regs.
  It is a list of places to put insructions to restore registers.
I If untidy is true, it means that sp shall not be restored.
*/

typedef struct rrs_tag {
  mach_ins* ins ;
  restore_type_t restore_type  ;
  struct rrs_tag* next ;
} rrs;

rrs* restore_regs_subsribers = 0 ;


/************************************************************************
 RESTORE_REGS

 Subscribe on code to restore registers. See restore_regs_output below.
 Restore_type is one of: ALL, NOT_SP, NOT_A6_OR_SP
 ************************************************************************/

void restore_regs
    PROTO_N ( ( typ ) )
    PROTO_T ( restore_type_t typ )
{
  rrs* p = (rrs*) xmalloc(sizeof(rrs)) ;
  p->ins  = current_ins ;
  p->next = restore_regs_subsribers ;
  p->restore_type = typ ;
  restore_regs_subsribers = p ;
}
/************************************************************************/
/* used by restore_regs_output below */

rrs* pop_restore_regs_subsriber
    PROTO_Z ()
{
   rrs* p = restore_regs_subsribers ;

   if (p != 0) {
      restore_regs_subsribers = p->next ;
   }

   return p ;
}

/************************************************************************
  RESTORE_REGS_OUTPUT

  Output instructions to restore registers.
  This is done in all places where the restore_regs call has been made.

  This procedure is called by epilogue after installing the body of a
  General Procedure. First then we know which registers to restore.

  rmsk is the set of normal regs to restore from AP - st
  fmsk is the set of floating point regs to restore from AP - st1

  side effect: current_ins is changed
 ************************************************************************/

void restore_regs_output
    PROTO_N ( ( rmsk, fmsk, st, st1, uses_link ) )
    PROTO_T ( bitpattern rmsk X bitpattern fmsk X long st X long st1 X bool uses_link )
{
   rrs* p ;
   while ( ( p = pop_restore_regs_subsriber () ) ) {
      mach_op *op1, *op2 ;
      current_ins = p->ins ;

      make_comment("Restore Registers") ;

      /* Restore floating-point registers from the stack */
      if ( fmsk ) {
         just_ret = 0 ;
         op1 = make_indirect ( REG_AP, -st1 ) ;
         op2 = make_hex_value ( fmsk ) ;
         make_instr ( m_fmovemx, op1, op2, fmsk ) ;
      }

      /* Restore registers from the stack */
      if ( rmsk ) {
         just_ret = 0 ;
         if ( must_use_bp ) {
            op1 = make_indirect ( REG_AP, -st ) ;
         } else {
            op1 = make_indirect ( REG_SP, 0 ) ;
         }
         op2 = make_hex_value ( rmsk ) ;
         make_instr ( m_moveml, op1, op2, rmsk ) ;
      }

      if ( uses_link ) {
         just_ret = 0 ;

         switch ( p->restore_type ){
         case ALL:
            /* Output unlink instruction */
            op1 = make_register ( REG_AP ) ;
            make_instr ( m_unlk, op1, null, regmsk ( REG_AP ) ) ;
            break;
         case NOT_SP:
            make_comment("untidy return => Restore A6, but not SP");
            op1 = make_indirect ( REG_AP, 0 ) ;
            op2 = make_register ( REG_AP ) ;
            make_instr ( m_movl, op1, op2, regmsk ( REG_AP ) ) ;
            break;
         case NOT_A6_OR_SP:
            make_comment("exit with long jump => Don't restore A6 or SP");
            break;
         default:
            error("wrong restore type");
         }
      }
   }
}

/************************************************************************
  CLEANUP_BT

  Cleanup before a tail call is performed. Used by tail_call.
  Restore registers and frees callees stack room and return address.
  ************************************************************************/

void cleanup_bt
    PROTO_N ( ( save_ret, rg ) )
    PROTO_T ( bool save_ret X int rg )
{
   mach_op *op1, *op2 ;

   make_comment ( "Cleanup before tail call ..." );

   /* save callees size in scratch register if needed */
   if (cur_proc_has_vcallees) {
      make_comment ( "save old callees size" );
      op1 = make_indirect ( REG_AP, 8 ) ;
      op2 = make_register ( REG_D0 ) ;
      make_instr ( m_movl, op1, op2, regmsk ( REG_D0 ) ) ;
   }

   /* subscribe on code to restore registers */
   restore_regs(ALL) ;

   if ( save_ret ) {
      make_comment ( "save return address in register" );
      op1 = make_indirect ( REG_SP, 0 ) ;
      op2 = make_register ( rg ) ;
      make_instr ( m_movl, op1, op2, regmsk ( rg ) ) ;
   }

   if ( cur_proc_has_vcallees ) {
      make_comment("cleanup variable callees and return address");
      op1 = make_register ( REG_D0 ) ;
      op2 = make_register ( REG_SP );
      make_instr ( m_addl, op1, op2, regmsk ( REG_SP ) );

      op1 = make_value ( 8 ) ;  /* size of callers pointer & ret.addr. */
      op2 = make_register ( REG_SP );
      make_instr ( m_addl, op1, op2, regmsk ( REG_SP ) );
   }
   else {
      make_comment("cleanup static callees and return address");
      op1 = make_value ( cur_proc_callees_size / 8 + 4 ) ;
      op2 = make_register ( REG_SP );
      make_instr ( m_addl, op1, op2, regmsk ( REG_SP ) );
   }
   make_comment ( "Cleanup before tail call done" );
}

/************************************************************************
  CLEANUP

  Restore registers and frees callees stack room, just before return from
  a procedure. Used by general_epilogue.
  The return address is restored.
  ************************************************************************/

void cleanup
    PROTO_Z ()
{
   mach_op *op1, *op2 ;
   bool callees_to_clean = cur_proc_has_vcallees || cur_proc_callees_size ;

   make_comment ( "Cleanup before return ..." );

   /* save callees size in scratch register if needed */
   if ( cur_proc_has_vcallees ) {
      make_comment ( "save callees size" );
      op1 = make_indirect ( REG_AP, 8 ) ;
      op2 = make_register ( REG_A0 ) ;
      make_instr ( m_movl, op1, op2, regmsk ( REG_A0 ) ) ;
   }

   /* subscribe on code to restore registers */
   restore_regs(ALL) ;

   if ( callees_to_clean ) {
      make_comment ( "save return address in register" );
      op1 = make_indirect ( REG_SP, 0 ) ;
      op2 = make_register ( REG_A1 ) ;
      make_instr ( m_movl, op1, op2, regmsk ( REG_A1 ) ) ;

      if ( cur_proc_has_vcallees ) {
         make_comment("cleanup variable callees and return address");
         op1 = make_register ( REG_A0 ) ;
         op2 = make_register ( REG_SP );
         make_instr ( m_addl, op1, op2, regmsk ( REG_SP ) );

         op1 = make_value ( 4 ) ; /* size of callers pointer */
         op2 = make_register ( REG_SP );
         make_instr ( m_addl, op1, op2, regmsk ( REG_SP ) );
      }
      else {
         make_comment("cleanup static callees");
         op1 = make_value ( cur_proc_callees_size / 8 ) ;
         op2 = make_register ( REG_SP );
         make_instr ( m_addl, op1, op2, regmsk ( REG_SP ) );
      }

      make_comment("put return address back on the stack");
      op1 = make_register ( REG_A1 ) ;
      op2 = make_indirect ( REG_SP, 0 ) ;
      make_instr ( m_movl, op1, op2, 0 ) ;
   }
   make_comment ( "Cleanup before return done" );
}

/************************************************************************
  PUSH_RANGE

  Push memory in the range [start, end] on the stack. (start > end).
  (modifies start, end, SP)
  ************************************************************************/

void push_range
    PROTO_N ( ( start, end ) )
    PROTO_T ( int start X int end )
{
   mach_op *op1, *op2 ;
   long lb ;

   make_comment("Push range");

   lb = next_lab () ;
   make_label ( lb ) ;

   op1 = make_predec ( start ) ;
   op2 = make_dec_sp () ;
   make_instr ( m_movw, op1, op2, regmsk ( REG_SP ) ) ;

   op1 = make_register ( start ) ;
   op2 = make_register ( end ) ;
   make_instr ( m_cmpl, op1, op2, 0 ) ;

   make_jump ( m_bne, lb ) ;
}

/************************************************************************
  MAKE_CALLEES_SIZE

  Returns an operand specifying the size of the callees for
  the current procedure.
  ************************************************************************/

mach_op* make_callees_size
    PROTO_Z ()
{
   /* Is it a run time value ? */
   if ( cur_proc_has_vcallees )
   return make_indirect ( REG_AP, 8 ) ;

   /* or compile time value ? */
   return make_value ( cur_proc_callees_size / 8 ) ;
}

/************************************************************************
  PUSH_SAME_CALLEES

  Used by apply_general_proc to push the same callees
  (modifies A0,D0,D1,SP)
  ************************************************************************/

void push_same_callees
    PROTO_N ( ( var_callees ) )
    PROTO_T ( bool var_callees )
{
   mach_op *op1, *op2 ;

   /* do we have any callees to push ? */
   if ( cur_proc_has_vcallees || cur_proc_callees_size ) {
      make_comment("Push same callees");
      make_comment("end of callees");
      op1 = make_register ( REG_AP ) ;
      op2 = make_register ( REG_D1 ) ;
      make_instr ( m_movl, op1, op2, regmsk ( REG_D1 ) ) ;

      /* add sizeof(ret-addr)+sizeof(preincrement) ?+sizeof(callees size)? */
      op1 = make_value( ( cur_proc_has_vcallees )? 12 : 8 ) ;
      op2 = make_register ( REG_D1 ) ;
      make_instr ( m_addl, op1, op2, regmsk ( REG_D1 ) ) ;

      make_comment("start of callees");
      op1 = make_register ( REG_D1 ) ;
      op2 = make_register ( REG_A0 ) ;
      make_instr ( m_movl, op1, op2, regmsk ( REG_A0 ) ) ;

      op1 = make_callees_size() ;
      op2 = make_register ( REG_A0 ) ;
      make_instr ( m_addl, op1, op2, regmsk ( REG_A0 ) ) ;

      push_range ( REG_A0, REG_D1 ) ;
   }

   if (var_callees) {
      make_comment("push size of callees on the stack");
      op1 = make_callees_size () ;
      op2 = make_dec_sp();
      make_instr ( m_movl, op1, op2, regmsk ( REG_SP )) ;

      stack_size -= 32 ;
   }
}

/************************************************************************
  PUSH_DYNAMIC_CALLEES

  Used by apply_general_proc to push dynamic callees
  Callees size is available in D1 afterwards.
  (modifies A0,D0,D1,SP)
  ************************************************************************/

void push_dynamic_callees
    PROTO_N ( ( pcallees, stack ) )
    PROTO_T ( exp pcallees X ash stack )
{
   mach_op *op1, *op2 ;
   exp ptr = son ( pcallees ) ;
   exp sze = bro ( ptr ) ;
   exp ident, ident_def ;
   bool const_compound_shape = 0 ;
   long total_size = 0 ;

   make_comment("Push dynamic callees");

   coder ( A1, stack, ptr ) ;
   coder ( D1, stack, sze ) ;

   /* are callees of compond shape ? */
   if ( name ( ptr ) == name_tag) {
      ident = son ( ptr ) ;
      ident_def = son ( ident ) ;
      if ( name ( ident_def ) == compound_tag ) {
         const_compound_shape = ! ( isvar ( ident ) ) ;
      }
   }

   if ( const_compound_shape ) {
      long value ;
      exp pair = son ( ident_def ) ;
      if ( pair ) for (;;) {
         pair = bro ( pair ) ;
         value = no ( pair ) ;

         op1 = make_value ( value ) ;
         op2 = make_dec_sp () ;
         make_instr ( m_movl, op1, op2, regmsk ( REG_SP ) ) ;
         total_size += 4 ;

         if ( last ( pair ) ) break ;
         pair = bro ( pair ) ;
      }
   }
   else {
      /* Let A0 point to end of callees */
      op1 = make_register ( REG_A1 ) ;
      op2 = make_register ( REG_A0 ) ;
      make_instr ( m_movl, op1, op2, regmsk ( REG_A0 ) ) ;

      op1 = make_register ( REG_D1 ) ;
      op2 = make_register ( REG_A0 ) ;
      make_instr ( m_addl, op1, op2, regmsk ( REG_A0 ) ) ;

      push_range ( REG_A0, REG_A1 ) ;
   }

   if ( call_has_vcallees(pcallees) ) {
      make_comment("push size of dynamic callees on the stack");
      if ( const_compound_shape ) {
         op1 = make_value ( total_size ) ;
      }
      else {
         op1 = make_register ( REG_D1 ) ;
      }
      op2 = make_dec_sp();
      make_instr ( m_movl, op1, op2, regmsk ( REG_SP )) ;

      stack_size -= 32 ;
   }
   else {
       debug_warning("call with dynamic callees requires var_callees PROCPROPS");
   }
}

/************************************************************************
  PUSH_DYNAMIC_CALLEES_BT

  Used by tail_call to push dynamic callees
  (modifies A0,A1,D0,D1,SP)
  ************************************************************************/

void push_dynamic_callees_bt
    PROTO_N ( ( pcallees, stack ) )
    PROTO_T ( exp pcallees X ash stack )
{
   mach_op *op1, *op2 ;

   push_dynamic_callees ( pcallees, stack );

   make_comment("push return address");
   op1 = make_indirect ( REG_AP, 4 ) ;
   op2 = make_dec_sp();
   make_instr ( m_movl, op1, op2, regmsk ( REG_SP ) ) ;

   make_comment("put end of callees, size & return address in A1");
   op1 = make_register ( REG_SP ) ;
   op2 = make_register ( REG_A1 ) ;
   make_instr ( m_movl, op1, op2, regmsk ( REG_A1 ) ) ;

   make_comment("put start of callees in A0");
   op1 = make_register ( REG_A1 ) ;
   op2 = make_register ( REG_A0 ) ;
   make_instr ( m_movl, op1, op2, regmsk ( REG_A0 ) ) ;

   /* add size of callee from D1 */
   op1 = make_register ( REG_D1 ) ;
   op2 = make_register ( REG_A0 ) ;
   make_instr ( m_addl, op1, op2, regmsk ( REG_A0 ) ) ;

   /* add size of return address and size of callees size if needed */
   op1 = make_value ((call_has_vcallees(pcallees)) ? 8 : 4) ;
   op2 = make_register ( REG_A0 ) ;
   make_instr ( m_addl, op1, op2, regmsk ( REG_A0 ) ) ;

   cleanup_bt (0, 0) ;

   push_range ( REG_A0, REG_A1 ) ;
}

/************************************************************************
  A1_RESULT_POINTER

  For results which do not fit into registers a pointer to
  where the result is to be put is passed in A1
  ************************************************************************/

void A1_result_pointer
    PROTO_N ( ( comp_size, longs, start_stack, dest ) )
    PROTO_T ( long comp_size X long longs X long start_stack X where dest )
{
   if ( comp_size ) {
      /* Find the space allocated for unwanted results */
      where w ;
      w = mnw ( longs / 8 ) ;
      make_comment("let A1 point to unwanted compund result") ;
      add ( slongsh, SP, w, A1 ) ;
   } else {
      long doff ;
      /* Find the address of where the result is to be put */
      tmp_reg_prefer = REG_A1 ;
      if ( apply_tag_flag ) {
         /* For recursive use of apply_proc or apply_general
            we need to be very careful if the result is itself
            to be a procedure argument to get the right stack offset. */

         /* push old value */
         long ex = extra_stack ;
         extra_stack += start_stack ;

         if ( (dest.wh_exp == SP_p.wh_exp) && (dest.wh_is == SP_p.wh_is) ) {
            /* Careful! */

            /* push where offset */
            doff = dest.wh_off ;

            dest.wh_off = doff + extra_stack ;

            make_comment("let A1 point to compund result used as procedure argument") ;
            mova ( dest, A1 ) ;

            /* pop where offset */
            dest.wh_off = doff ;

         } else {
            /* Easy */
            make_comment("let A1 point to compund result from eval. of call par.") ;
            mova ( dest, A1 ) ;
         }

         /* pop value after call */
         extra_stack = ex  ;
      }
      else {
         /* Otherwise (easy) ... */
         make_comment("let A1 point to compund result") ;
         mova ( dest, A1 ) ;
      }
   }
   /* Make sure we don't reuse A1 accidently */
   avoid_tmp_reg ( REG_A1 ) ;
   regsinproc |= regmsk ( REG_A1 ) ;
}

/************************************************************************
  POSTLUDE_HAS_CODE

  Returns true if postlude has code
  ************************************************************************/

static bool postlude_has_code
    PROTO_N ( ( postlude ) )
    PROTO_T ( exp postlude )
{
   while ( name( postlude ) == ident_tag && name(son( postlude )) == caller_name_tag) {
      postlude = bro( son( postlude ) );
   }
   return ( name( postlude ) != top_tag ) ;
}


/************************************************************************
  APPLY_GENERAL_PROC

  Code a General Procedure Call.
  ************************************************************************/

void apply_general_proc
    PROTO_N ( ( e, dest, stack ) )
    PROTO_T ( exp e X where dest X ash stack )
{

   /* Procedure applications */
   exp t ;
   ash st ;
   where tmp_dest;
   mach_op *op1, *op2 ;
   long comp_size = 0 ;
   long longs = 0, stkdec ;
   long start_stack = stack_dec ;
   long callers_size = 0, callees_size = 0 ; /* size of parameters on the stack */
   long size_size = 0 ;                      /* size of callees size */
   long callees_size_total = 0 ;             /* size of callees and callees size */
   long result_size = 0 ;                    /* size of result */

   bool push_result = 0, use_push = 1, reg_res ;
   bool has_postlude = 0, has_checkstack = 0, is_untidy = 0 ;

   exp proc, caller_args, pcallees = 0, postlude = 0, callee_args = 0 ;

   make_comment("Apply Proc");

   /* Find the procedure and the arguments */

   tmp_dest = dest ;
   proc = son ( e ) ;
   caller_args = (!last(proc)) ? bro (proc) : nilexp;

   if ( name(e) == apply_general_tag) {
      pcallees     = bro ( caller_args ) ;
      postlude    = bro ( pcallees );
      callee_args = son ( pcallees ) ;
      caller_args = son ( caller_args );

      is_untidy = call_is_untidy(e);
      has_checkstack = call_has_checkstack(e);
      has_postlude = postlude_has_code( postlude ) ;
   }

   /* calculate length of callers and see if we can push them */

   if (! test_push_args(caller_args, &callers_size) ) use_push = 0;

   if ( pcallees ) {
      if ( name( pcallees ) == make_callee_list_tag ) {
         /* calculate length of callees and see if we can push them */
         if (! test_push_args(callee_args, &callees_size) ) use_push = 0;
      }
      size_size = ( ( call_has_vcallees(pcallees) )?32:0 ) ;
      callees_size_total = callees_size + size_size ;
   }

   /* total parameter space */
   longs = callers_size + callees_size_total ;

   /* Does the result go into a register? */
   reg_res = result_in_reg ( sh ( e ) ) ;
   if ( !reg_res ) {
      if ( eq_where ( dest, zero ) ) {
         /* Calculate size of ignored compound result */
         comp_size = round ( shape_size ( sh ( e ) ), param_align ) ;
      }
   }

   /* Find total amount of stack decrease */
   stkdec = longs + comp_size ;

   if ( has_checkstack ) {
      /* check if there is room for parameters and return address on the stack */
      checkalloc_stack( mnw( stkdec / 8 + 4 ), 0);
   }

   /* Put arguments onto stack */
   if ( use_push ) {
      if ( comp_size ) {
         /* Make room for unwanted compound result */
         dec_stack ( comp_size ) ;
         stack_dec -= comp_size ;
      }

      if ( caller_args ) {
         make_comment("Push callers");
         push_args ( zw ( e ), stack, caller_args ) ;
      }

      if ( pcallees ) {
         if ( name(pcallees) == make_dynamic_callee_tag ) {
            push_dynamic_callees ( pcallees, stack ) ;
            stack_dec -= callees_size_total ;
         }
         else if ( name(pcallees) == same_callees_tag ) {
            push_same_callees(call_has_vcallees(pcallees)) ;
            stack_dec -= callees_size_total ;
         }
         else {
            if ( callee_args ) {
               make_comment("Push static callees");
               push_args ( zw ( e ), stack, callee_args ) ;
            }
            if ( call_has_vcallees(pcallees) ) {
               make_comment("push size of callees on the stack");
               stack_dec -= 32 ;
               stack_size -= 32 ;

               op1 = make_value ( callees_size / 8 ) ;
               op2 = make_dec_sp();
               make_instr ( m_movl, op1, op2, regmsk ( REG_SP )) ;
            }
         }
      }
   }
   else {
      /* Can't just use push => Decrease stack instead */
      dec_stack ( stkdec ) ;
      stack_dec -= stkdec ;

      if ( caller_args ) {
         make_comment("Place callers on the stack");
         place_arguments(caller_args, stack, callees_size_total);
      }
      if ( pcallees ) {
         if ( name(pcallees) == make_dynamic_callee_tag ) {
            push_dynamic_callees ( pcallees, stack ) ;
         }
         else if ( name(pcallees) == same_callees_tag ) {
            push_same_callees(call_has_vcallees(pcallees)) ;
         }
         else {
            if ( callee_args ) {
               make_comment("Place static callees on the stack");
               place_arguments(callee_args, stack, size_size);
            }
            if ( call_has_vcallees(pcallees) ) {
               make_comment("push size of callees on the stack");
               op1 = make_value ( callees_size / 8 ) ;
               op2 = make_indirect ( REG_SP, 0 ) ;
               make_instr ( m_movl, op1, op2, regmsk ( REG_SP )) ;
            }
         }
      }
   }

   start_stack -= stack_dec ;

   if ( !reg_res )
   A1_result_pointer(comp_size, longs, start_stack, dest) ;

   /* Output the call instruction */
   callins ( 0, proc ) ;

   if ( is_untidy ) {
      stack_dec = 0; /* We can't keep track of it any longer */
      if (need_preserve_stack)
      save_stack ();
   }
   else {
      /* callees has now been cleaned up by called proc. */
      stack_dec += callees_size_total ;
      stack_size += callees_size_total ;
   }

   /* can we cleanup callers now ? */
   if ( ! ( has_postlude || is_untidy ) ) {
      /* Clean up of callers and room for ignored compund result. */
      stack_dec += callers_size + comp_size ;
      dec_stack ( - callers_size - comp_size );
   }

   /* Move the result into place */
   if ( comp_size ) {
      make_comment("(unwanted compound result)");
   }
   else
   if ( eq_where ( dest, zero ) ) {
      make_comment("(unwanted simple result)");
   }
   else {
      /* ok the result is needed */
      if ( has_postlude ) {
         /* we need to preserve result on stack */
         result_size = rounder (shape_size(sh(e)), param_align);
         dec_stack ( result_size ) ;
         stack_dec -= result_size;
         tmp_dest = SP_p ;
         push_result = 1 ;
      }
      if ( reg_res ) {
         if ( shape_size ( sh ( e ) ) <= 32 ) {
            /* Small register results are in D0 */
            move ( sh ( e ), D0, tmp_dest ) ;
         } else {
            /* Larger register results are in D0 and D1 */
#ifdef SYSV_ABI
            move ( sh ( e ), FP0, tmp_dest ) ;
#else
            move ( sh ( e ), D0_D1, tmp_dest ) ;
            regsinproc |= regmsk ( REG_D1 ) ;
#endif
         }
      } else {
         make_comment("(compound result)");
         if ( has_postlude ) {
            make_comment("save compound result before postlude...") ;
            move ( sh ( e ), dest, tmp_dest ) ;
            make_comment("save compound result before postlude done") ;
         }

         /* Compound results should already have been copied to
            the position pointed to by A1 by the called procedure
            and returned by it in D0, so no further action should
            be required by the calling procedure.  Unfortunately
            cc doesn't always get this right for union results. */
#ifdef OLD_SPEC
         if ( cc_conventions && name ( sh ( e ) ) == unhd ) {
            regsinproc |= regmsk ( REG_A0 ) ;
            move ( slongsh, D0, A0 ) ;
            move ( sh ( e ), A0_p, dest ) ;
         }
#endif
      }
   }

   if ( has_postlude ) {
      code_postlude(postlude, caller_args, stack, result_size ) ;

      /* put return value back in register */
      if ( push_result ) {
         make_comment("restore result after postlude...") ;
         move(sh(e), SP_p, dest);
         make_comment("restore result after postlude done") ;
         dec_stack ( -result_size ) ;
         stack_dec += result_size;
      }

      /* Delayed clean up of callers and room for ignored compund result.
         callees are cleaned by the called proc. */
      if ( ! is_untidy ) {
         stack_dec += callers_size + comp_size ;
         dec_stack ( - callers_size - comp_size );
      }
   }
}

/************************************************************************
  TEST_PUSH_ARGS

  The total stack space requiered by the arguments is returned in args_size.

  Returns true if all arguments (args) can be pushed to the stack.

  The args_size is also used if false is returned.

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

static bool test_push_args
    PROTO_N ( (args, args_size) )
    PROTO_T ( exp args X ash* args_size )
{

   /* See if we can push all the arguments */

   bool use_push = 1 ;
   exp arg = args, formal ;
   ash stack = 0 ;
   ast stack_add_res;

   while ( arg != nilexp ) {
      formal = ( name ( arg ) == caller_tag) ? son ( arg ) : arg ;

      if ( cpd_param ( sh ( formal ) ) ) use_push = 0 ;
      if ((name(sh(formal)) == s64hd) || (name(sh(formal)) == u64hd)) use_push = 0;
      if (! push_arg ( formal ) ) use_push = 0 ;

      stack_add_res = add_shape_to_stack ( stack, sh ( formal ) ) ;
      stack = stack_add_res.astash ;

      /* information used by code_postlude */
      if ( name ( arg ) == caller_tag)
      no ( arg ) = stack_add_res.astoff + stack_add_res.astadj ;

      arg = ( last ( arg ) ? nilexp : bro ( arg ) ) ;
   }

   (* args_size) = stack ;


   return use_push ;
}


/************************************************************************
  PLACE_ARGUMENTS

  Encodes procedure arguments on the stack.
  ************************************************************************/

static void place_arguments
    PROTO_N ( (args, stack, start) )
    PROTO_T ( exp args X ash stack X long start )
{
   exp arg = args ;
   ast stack_add_res ;
   where stack_pointer ;
   long adj ;
   long st = start ;

   /* Indicate recursive calls */
   apply_tag_flag ++ ;

   /* Encode the arguments onto the stack */
   while (arg != nilexp) {
      exp formal = ( name ( arg ) == caller_tag) ? son ( arg ) : arg ;

      char nc = name ( sh ( formal ) ) ;
      if ( nc == scharhd || nc == ucharhd ) adj = 24 ;
      else
      if ( nc == swordhd || nc == uwordhd ) adj = 16 ;
      else adj = 0 ;

      stack_pointer = mw ( SP_p.wh_exp, st + adj ) ;
      coder ( stack_pointer, stack, formal ) ;
      stack_add_res = add_shape_to_stack ( st, sh ( formal ) ) ;
      st = stack_add_res.astash ;

      arg = ( last ( arg ) ? nilexp : bro ( arg ) ) ;
   }

   apply_tag_flag -- ;
}

/************************************************************************
  PUSH A SET OF PROCEDURE ARGUMENTS

  The arguments are given by a bro-list t.
  They are coded in reverse order.
  ************************************************************************/

static void push_args
    PROTO_N ( ( w, stack, args ) )
    PROTO_T ( where w X ash stack X exp args )
{
   long sz = shape_size ( sh ( args ) ) ;
   exp formal ;

   if ( last ( args ) ) {
      /* Code last argument */
      formal = ( name ( args ) == caller_tag) ? son ( args ) : args ;
      coder ( w, stack, formal ) ;
      stack_dec -= rounder ( sz, param_align ) ;
   } else {
      /* Code the following arguments */
      push_args ( w, stack, bro ( args ) ) ;
      /* And then this one */
      formal = ( name ( args ) == caller_tag) ? son ( args ) : args ;
      coder ( w, stack, formal ) ;
      stack_dec -= rounder ( sz, param_align  ) ;
   }
   return ;
}

/************************************************************************
  TAIL_CALL

  Code a tail call.
  ************************************************************************/

void tail_call
    PROTO_N ( ( e, dest, stack ) )
    PROTO_T ( exp e X where dest X ash stack )
{
   exp proc        = son ( e );
   exp pcallees     = bro( proc );
   exp callee_args = son ( pcallees );
   int longs;
   mach_op *op1, *op2 ;
   long new_callees_size ;
   bool use_push = 1 ;

   make_comment("Tail Call");

   update_stack() ;

   if ( name(pcallees) == make_dynamic_callee_tag ) {
      /* A0 and A1 are used by cleanup. We are just about to make the tail
         call with shape bottom, so they are free */
      push_dynamic_callees_bt ( pcallees, stack ) ;
      jmpins(proc) ;
      return ;
   }

   /* same callees ? */

   if ( name(pcallees) == same_callees_tag ) {
      restore_regs(ALL) ;

      if ( ! cur_proc_has_vcallees  && call_has_vcallees(pcallees) ) {
         make_comment("push size of same static callees and ret.addr. on the stack");
         op1 = make_indirect ( REG_SP, 0 ) ;
         op2 = make_register ( REG_D0 );
         make_instr ( m_movl, op1, op2, regmsk ( REG_SP )) ;

         op1 = make_callees_size () ;
         op2 = make_indirect ( REG_SP, 0 ) ;
         make_instr ( m_movl, op1, op2, regmsk ( REG_SP )) ;

         op1 = make_register ( REG_D0 );
         op2 = make_dec_sp () ;
         make_instr ( m_movl, op1, op2, regmsk ( REG_SP )) ;
      }
      else if ( cur_proc_has_vcallees  && ! call_has_vcallees(pcallees) ) {
         make_comment("remove size of same static callees from the stack");
         op1 = make_inc_sp () ;
         op2 = make_indirect ( REG_SP, 0 ) ;
         make_instr ( m_movl, op1, op2, regmsk ( REG_SP )) ;
      }
      jmpins(proc) ;
      return ;
   }

   /* nothing more than same calleers ? */

   if (! (callee_args || cur_proc_has_vcallees || call_has_vcallees(pcallees))) {
      restore_regs(ALL) ;
      jmpins(proc) ;
      return ;
   }

   /* no callees ? */

   if ( ! callee_args ) {
      make_comment("save return address");
      op1 = make_indirect ( REG_AP, 4 ) ;
      op2 = make_register ( REG_A1 ) ;
      make_instr ( m_movl, op1, op2, regmsk ( REG_D0 ) ) ;

      cleanup_bt(0,0);

      if ( call_has_vcallees( pcallees ) ) {
         make_comment("push zero size of callees on the stack");
         op1 = make_value ( 0 ) ;
         op2 = make_dec_sp();
         make_instr ( m_movl, op1, op2, regmsk ( REG_SP )) ;
      }

      make_comment("push return address back");
      op1 = make_register ( REG_A1 ) ;
      op2 = make_dec_sp();
      make_instr ( m_movl, op1, op2, regmsk ( REG_SP )) ;

      jmpins(proc) ;
      return ;
   }

   /* new callees ! */

   if (! test_push_args(callee_args, &new_callees_size) ) use_push = 0;

   if ( use_push ) {
      make_comment("Push callees");
      push_args ( zw ( e ), stack, callee_args ) ;
   }
   else {
      /* Decrease stack */
      dec_stack ( new_callees_size ) ;
      stack_dec -= new_callees_size ;
      place_arguments(callee_args, stack, 0) ;
   }

   if ( call_has_vcallees(pcallees) ) {
      make_comment("push size of new callees on the stack");
      op1 = make_value ( new_callees_size / 8 ) ;
      op2 = make_dec_sp();
      make_instr ( m_movl, op1, op2, regmsk ( REG_SP )) ;
   }

   make_comment("push return address");
   op1 = make_indirect ( REG_AP, 4 ) ;
   op2 = make_dec_sp();
   make_instr ( m_movl, op1, op2, regmsk ( REG_SP ) ) ;

   /*
      Setup source, dest and end mark for push_range
      We will use D1 & A0.
      */

   make_comment("save end of new callees and return address");
   op1 = make_register ( REG_SP ) ;
   op2 = make_register ( REG_D1 ) ;
   make_instr ( m_movl, op1, op2, regmsk ( REG_D1 ) ) ;

   make_comment("save start of new callees and return address");
   op1 = make_register ( REG_SP ) ;
   op2 = make_register ( REG_A0 ) ;
   make_instr ( m_movl, op1, op2, regmsk ( REG_A0 ) ) ;

   /* add sizeof(new calless) sizeof(ret-addr) + ?+sizeof(callees size)? */
   op1 = make_value(new_callees_size/8+4+(call_has_vcallees(pcallees)?4:0));
   op2 = make_register ( REG_A0 ) ;
   make_instr ( m_addl, op1, op2, regmsk ( REG_A0 ) ) ;

   cleanup_bt(0,0) ;

   make_comment("push the new callees");
   push_range ( REG_A0, REG_D1 ) ;

   /* make the jump instruction */
   jmpins(proc) ;
}


/************************************************************************
  GENERAL PURPOSE PROCEDURE EPILOGUE

  The registers used in the procedure and the space used on the stack
  are analysed and used to form the procedure epilogue.
  There is some testing to see if D1, A0, A1 and FP1 can be put to
  better use.
  ************************************************************************/

void general_epilogue
    PROTO_N ( ( uses_callers_pointer, has_checkstack ) )
    PROTO_T ( bool uses_callers_pointer X bool has_checkstack )
{
   int r, instruction_id ;
   bitpattern m ;
   long st, st1 ;
   mach_op *op1, *op2 ;
   mach_ins * save_ins_pointer ;

   int tmp_d1 = -1, tmp_a0 = -1, tmp_a1 = -1 ;

   bitpattern rmsk = regs ( regsinproc & save_msk ) ;
   bitpattern smsk = rmsk ;
   bitpattern cmsk = 0 ;
   bitpattern fmsk = 0 ;
   bitpattern fsmsk = fregs ( regsinproc & save_msk ) ;
   bool d1_free ;
   bool save_d1 = 0 ;
   bool uses_link = 0 ;

   make_comment("Epilogue");

   /* restore the default floating point rounding mode */
   reset_round_mode();

   for ( r = REG_FP7, m = 1 ; r >= REG_FP2 ; r--, m <<= 1 ) {
      if ( regsinproc & regmsk ( r ) ) fmsk |= m ;
   }

   /* any calls? */
   if ( no_calls > 0 ) {
      if (uses_callers_pointer) {
         /* Variable number of calles => A5 used as pointer to first caller */
         smsk &= ~regmsk ( REG_A5 ) ;
      }

      smsk &= ~bigregs ;
      fsmsk &= ~bigregs ;
   }

   make_label ( crt_ret_lab ) ;

#if have_diagnostics
   if ( diagnose ) xdb_diag_proc_return () ;
#endif

   d1_free = !( regsinproc & regmsk ( REG_D1 ) ) ;

   /* Use D1 if not already used */
   if ( d1_free ) {
      m = smsk & dreg_msk ;     /* m = set of D'regs */
      if ( m ) {
         /* Replace a used D-register by D1 */
         r = reg ( m ) ;        /* get the first free register number in the set */
         reg_names [r] = reg_names [ REG_D1 ] ;
         rmsk &= ~regmsk ( r ) ;
         smsk &= ~regmsk ( r ) ;
         cmsk |= regmsk ( r ) ;
         d1_free = 0 ;
      }
   }

   /* Use A0 if not already used */
   if ( !( regsinproc & regmsk ( REG_A0 ) ) ) {
      m = smsk & areg_msk ;
      if ( m ) {
         /* Replace a used A-register by A0 */
         r = reg ( m ) ;
         reg_names [r] = reg_names [ REG_A0 ] ;
         rmsk &= ~regmsk ( r ) ;
         smsk &= ~regmsk ( r ) ;
         cmsk |= regmsk ( r ) ;
      } else if ( no_calls == 0 ) {
         m = rmsk & dreg_msk ;
         if ( m ) {
            /* Move a used D-register into A0 */
            tmp_a0 = reg ( m ) ;
            rmsk &= ~regmsk ( tmp_a0 ) ;
            smsk = rmsk ;
            op1 = make_register ( REG_A0 ) ;
            op2 = make_register ( tmp_a0 ) ;
            make_instr ( m_movl, op1, op2, regmsk ( tmp_a0 ) ) ;
            just_ret = 0 ;
         }
      }
   }

   /* Use A1 if not already used */
   if ( !( regsinproc & regmsk ( REG_A1 ) ) ) {
      m = smsk & areg_msk ;
      if ( m ) {
         /* Replace a used A-register by A1 */
         r = reg ( m ) ;
         reg_names [r] = reg_names [ REG_A1 ] ;
         rmsk &= ~regmsk ( r ) ;
         smsk &= ~regmsk ( r ) ;
         cmsk |= regmsk ( r ) ;
      } else if ( no_calls == 0 ) {
         m = rmsk & dreg_msk ;
         if ( m ) {
            /* Move a used D-register into A1 */
            tmp_a1 = reg ( m ) ;
            rmsk &= ~regmsk ( tmp_a1 ) ;
            smsk = rmsk ;
            op1 = make_register ( REG_A1 ) ;
            op2 = make_register ( tmp_a1 ) ;
            make_instr ( m_movl, op1, op2, regmsk ( tmp_a1 ) ) ;
            just_ret = 0 ;
         }
      }
   }

   /* Use FP1 if not already used */
   if ( fsmsk && !( regsinproc & regmsk ( REG_FP1 ) ) ) {
      for ( r = REG_FP7, m = 1 ; r >= REG_FP2 ; r--, m <<= 1 ) {
         if ( fsmsk & regmsk ( r ) ) {
            reg_names [r] = reg_names [ REG_FP1 ] ;
            fmsk &= ~m ;
            fsmsk &= ~regmsk ( r ) ;
            cmsk |= regmsk ( r ) ;
            r = REG_FP1 ;
         }
      }
   }

   if ( d1_free && no_calls == 0 ) {
      m = rmsk & areg_msk ;
      if ( m ) {
         /* Move a used A-register into D1 */
         tmp_d1 = reg ( m ) ;
         rmsk &= ~regmsk ( tmp_d1 ) ;
         op1 = make_register ( REG_D1 ) ;
         op2 = make_register ( tmp_d1 ) ;
         make_instr ( m_movl, op1, op2, regmsk ( tmp_d1 ) ) ;
         just_ret = 0 ;
      }
   }

   /* Calculate stack displacements */
   st1 = round ( max_stack, 32 ) / 8 + 16 * bits_in ( fmsk ) ;
   st = st1 + 4 * bits_in ( rmsk ) ;

   if ( st1 || st || used_stack || must_use_bp || cur_proc_has_vcallees ) uses_link = 1 ;

   cleanup() ;

   /* Output return instruction */
   make_instr ( m_rts, null, null, 0 ) ;

   /* Output instructions to restore registers */
   save_ins_pointer = current_ins ;
   restore_regs_output(rmsk, fmsk, st, st1, uses_link) ;

   /* Go back to the prologue position */
   current_ins = prologue_ins ;

   /* Calculate the offset between procedure args and sp */
   ldisp = (uses_link ? st + 4 : st ) ;

   /* Calculate env_size ( ldisp + sizeof(return address) + sizeof(params) )*/
   cur_proc_env_size = ldisp + 4 + (cur_proc_callers_size + cur_proc_callees_size)/8 ;
#if 0
   if ( has_checkstack )
   cur_proc_env_size += 1024 ; /* room for exception handler */
#endif

   if ( uses_link ) {
      /* Output link instruction */
      /* push AP; AP = SP; sp=sp-st */
      instruction_id = ( -st > 0x7fff ? m_linkl : m_linkw ) ;
      op1 = make_register ( REG_AP ) ;
      op2 = make_value ( -st ) ;
      make_instr ( instruction_id, op1, op2, regmsk ( REG_AP ) | regmsk ( REG_SP ) ) ;
   }

   /* Save register in D1 if necessary */
   if ( tmp_d1 >= 0 ) {
      op1 = make_register ( tmp_d1 ) ;
      op2 = make_register ( REG_D1 ) ;
      make_instr ( m_movl, op1, op2, regmsk ( REG_D1 ) ) ;
   }

   /* Save register in A0 if necessary */
   if ( tmp_a0 >= 0 ) {
      op1 = make_register ( tmp_a0 ) ;
      op2 = make_register ( REG_A0 ) ;
      make_instr ( m_movl, op1, op2, regmsk ( REG_A0 ) ) ;
   }

   /* Save register in A1 if necessary */
   if ( tmp_a1 >= 0 ) {
      op1 = make_register ( tmp_a1 ) ;
      op2 = make_register ( REG_A1 ) ;
      make_instr ( m_movl, op1, op2, regmsk ( REG_A1 ) ) ;
   }

   /* Put registers onto the stack */
   if ( rmsk ) {
      op1 = make_hex_value ( rmsk ) ;
      op2 = make_indirect ( REG_SP, 0 ) ;
      make_instr ( m_moveml, op1, op2, 0 ) ;
   }

   /* Put floating-point registers onto the stack */
   if ( fmsk ) {
      op1 = make_hex_value ( fmsk ) ;
      op2 = make_indirect ( REG_AP, -st1 ) ;
      make_instr ( m_fmovemx, op1, op2, 0 ) ;
   }

   if (uses_callers_pointer){
      make_comment("Variable callees => Get address of first caller");

      regsinproc |= regmsk ( REG_A5 ) ;

      op1 = make_register ( REG_AP ) ;
      op2 = make_register ( REG_A5 ) ;
      make_instr ( m_movl, op1, op2, regmsk ( REG_A5 ) ) ;

      /* A5 = AP + cur_proc_callees_size */
      /* AP points to the first parameter, callees size is before */
      op1 = make_callees_size () ;
      op2 = make_register ( REG_A5 ) ;
      make_instr ( m_addl, op1, op2, regmsk ( REG_A5 ) ) ;

      op1 = make_value ( 12 ) ;
      op2 = make_register ( REG_A5 ) ;
      make_instr ( m_addl, op1, op2, regmsk ( REG_A5 ) ) ;
   }


   /* Return to previous position */
   current_ins = save_ins_pointer ;

   callmsk = cmsk ;
   have_cond = 0 ;
   return ;
}

/************************************************************************
  CODE_POSTLUDE
  The postlude parameters positions on the stack are setup, and coder
  is called with the postlude body.

  ************************************************************************/
static void code_postlude
    PROTO_N ( ( postlude, callers, stack, post_offset ) )
    PROTO_T ( exp postlude X exp callers X ash stack X long post_offset )
{
   make_comment("Postlude ...");

   /* mark parameters by use of the values calculated by gcproc */
   while ( name( postlude ) == ident_tag && name(son( postlude )) == caller_name_tag) {
      int n = no(son( postlude ));
      exp a = callers;
      while (n != 0) {
         a = bro(a);
         n--;
      }
      if (name(a) != caller_tag)
      error("Bad postlude") ;

      ptno( postlude ) = par3_pl;
      no( postlude ) = no(a) + stack_dec + post_offset ;

      postlude = bro( son( postlude ) );
   }

   /* code the postlude */
   coder ( zero, stack, postlude ) ;

   make_comment("Postlude done");
}

/************************************************************************
  Makes code for untidy return
  ************************************************************************/

void untidy_return
    PROTO_Z ()
{
   mach_op *op1, *op2 ;

   make_comment("untidy return") ;

   make_comment("push return address");
   op1 = make_indirect ( REG_AP, 4 ) ;
   op2 = make_dec_sp();
   make_instr ( m_movl, op1, op2, regmsk ( REG_SP ) ) ;

   restore_regs(NOT_SP) ;
   /* Output return instruction */
   make_instr ( m_rts, null, null, 0 ) ;
}

/************************************************************************
  Make a label with named after the address of e and the value of the
  env offset from e (an ident_tag) to the application pointer.
  ************************************************************************/

void make_visible
    PROTO_N ( ( e ) )
    PROTO_T ( exp e )
{
   mach_op *op1, *op2 ;
   long offval ;

   /* Does it need to be visible? */

   if (! ((isvis(e)) || (isenvoff(e))) ) return ;

   setismarked(e) ;

   switch ( ptno( e ) ) {
   case var_pl:
      offval = -no(e)/8;
      break;
   case par2_pl:
      offval = no(e)/8;
      break;
   case par3_pl:
   case par_pl:
   default:
      offval = no(e)/8 + 4;
      if(used_stack) offval += 4;
   }
   op1 = make_lab_data ((long)e, 0) ;
   op2 = make_int_data (offval) ;
   make_instr_aux ( m_as_assign, op1, op2, 0, 0 ) ;
}


/************************************************************************
  If a caller parameter is accessed from a framepointer with variable
  callees we need to transform the pointer in the addptr expression to
  callers pointer.
  ************************************************************************/

void fix_addptr
    PROTO_N ( ( addptr ) )
    PROTO_T ( exp addptr )
{
   exp pointer  = son ( addptr ) ;
   exp offset   = bro ( pointer ) ;
   exp E1,E2,E3,E4,E5;
   shape pc_sh;

   /* access of a caller param. relative to an environment with variable? */

   if (! ((frame_al_of_ptr(sh(pointer)) & al_includes_vcallees) &&
          (frame_al1_of_offset(sh(offset)) & al_includes_caller_args)) ) return;


   /*
      exchange application pointer with callers pointer:

      addptr(pointer, offset) --> addptr(pointer2, offset)
      where pointer2 = reff(addptr( pointer, cont( reff( pointer, 8*8) ) ), 12*8)


                         addptr
                           |
                           |(son)   bro(son)
                           |-------------|
                     E5  reff(8*8)     offset
                           |(son)
                           |
                     E4  addptr
                           |(son)   bro(son)
                           |----------|
                        pointer  E3  cont
                                      |(son)
                                      |
                                 E2  reff(12*8)
                                      |(son)
                                      |
                                 E1  pointer (copy)


      */

   pc_sh = f_pointer(f_callers_alignment(0));

   E1 = copyexp(pointer) ;
   E2 = getexp (pc_sh, 0, 0, E1, 0, 0, 8*8, reff_tag);
   E3 = getexp (pc_sh, 0, 0, E2, 0, 0, 0, cont_tag);
   E4 = getexp (pc_sh, 0, 0, pointer, 0, 0, 0, addptr_tag);
   E5 = getexp (pc_sh, 0, 0, E4, 0, 0, 12*8, reff_tag);
   son(addptr) = E5;

   /* Terminate each bro list */
   setfather (E2, E1);
   setfather (E3, E2);
   setfather (E4, E3);
   setfather (E5, E4);

   bro (pointer) = E3;
   bro (E5) = offset;
}

/************************************************************************
  Transforms an entire exp recursively.
  ************************************************************************/
static void transform
    PROTO_N ( ( e ) )
    PROTO_T ( exp e )
{
   exp s = son(e) ;

   /* Transform the childs (if any) */
   if ( s && (name(e) != name_tag) && (name(e) != env_offset_tag) && (name(e) != case_tag) )
   for (; s && s!=e; s=bro(s)) {
      transform(s);
   }

   /* Transform this one */
   switch ( name( e ) ) {
   case addptr_tag:
      fix_addptr(e);
      break;
   default:
      /* nothing to do */
      break;
   }
}

/************************************************************************
  Scan through the declarations and apply transform
  called from trans.
  ************************************************************************/
void make_transformations
    PROTO_Z ()
{
   dec *d = top_def ;

   while ( d ) {
      exp e = son ( d->dec_u.dec_val.dec_exp ) ;
      if ( e ) transform ( e ) ;
      d = d->def_next ;
   }
}
/************************************************************************
  Make a label with:
  value: env_size ( proc )
  name:  L<value of procedure declaration pointer)
  ************************************************************************/

void output_env_size
    PROTO_N ( ( proc, envsize ) )
    PROTO_T ( dec* proc X long envsize )
{
   mach_op *op1, *op2 ;
   long offval ;

   make_comment("env_size comes here:");
   op1 = make_lab_data ((long)proc, 0) ;
   op2 = make_int_data (envsize) ;
   make_instr_aux ( m_as_assign, op1, op2, 0, 0 ) ;
}


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