aboutsummaryrefslogblamecommitdiffstats
path: root/erts/emulator/beam/erl_term.h
blob: 25d12bf16ea712ecd553f51d33836a4601cd7313 (plain) (tree)
1
2
3
4
5
6
7
8
9
10

                   


                                                        




                                                                      
  



                                                                         
  





                    
                                            










                                                   

                                                                   











                                               

















                                                                 
                                                                                    






















































































































                                                                                                  
                 
                                                                                 




                                                         
                                                        
                                                                                 
                                             



                                                                             
                                       



                                                                                
                                                                                    
                                            


                                                        
                                                                               
                                            


                                                                              
                                          





                                                                               




                                            
                                                                                
                                           








                                                           
                                                                              




                                                                       
                                      















                                                                                                              
                                            

                                                                       
                                          





















                                                                                
                                        





                                                                            
                                            






                                                                                  
                                        




                                                                    
                                              

                                                                   
                                            




























                                                                                                     
                                            















                                                                                 
                                         






                                                                             
                                            

                                                      


                                                          
                                                          
      





                                                                                                 
                                                   

                                                                   
                                                  

                                                                            
                                                   





                                                                             
                                         


                                                      
                                      







                                                                           
                                           










                                                  
                                      



               
                                      




























                                                                          
                                           









































































































































                                                                             
                                                 


                                                             
                                                              


















































                                                                              
                                                  




                                                                      
                                                               



































































                                                                            
                                      




















                                                          
                                      


















































                                                                             
                                                  



                                                             
                                                       


                                                                                
                                                    


                                                             
                                                              
































































































                                                                              
                                              








                                                                          
                                                   









                                                                                 
                                                       


                                                                         
                                                 


                                                                     
                                                              






                                                                   
                                                        


                                                                           
                                                  


                                                                      
                                                               





                                                                      
                                                       


                                                                                       
                                                    


                                                                     
                                                              


















                                                                    
                                                             
                                              




                                              

                                                                





                                                                       
                                         




























                                                                           
                                           


                                                         
                                           




                                                   
                                          


                                                  
                                          

















































                                                                         
/*
 * %CopyrightBegin%
 *
 * Copyright Ericsson AB 2000-2010. All Rights Reserved.
 *
 * The contents of this file are subject to the Erlang Public License,
 * Version 1.1, (the "License"); you may not use this file except in
 * compliance with the License. You should have received a copy of the
 * Erlang Public License along with this software. If not, it can be
 * retrieved online at http://www.erlang.org/.
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 * the License for the specific language governing rights and limitations
 * under the License.
 *
 * %CopyrightEnd%
 */

#ifndef __ERL_TERM_H
#define __ERL_TERM_H

#include "sys.h" /* defines HALFWORD_HEAP */

#if HALFWORD_HEAP
#  define HEAP_ON_C_STACK 0
#  if HALFWORD_ASSERT
#    ifdef ET_DEBUG
#      undef ET_DEBUG
#    endif
#    define ET_DEBUG 1
#  endif
#  if 1
#    define CHECK_POINTER_MASK 0xFFFFFFFF00000000UL
#    define COMPRESS_POINTER(APointer) ((Eterm) (UWord) (APointer))
#    define EXPAND_POINTER(AnEterm) ((UWord) (AnEterm))
#  else
#    define CHECK_POINTER_MASK 0x0UL
#    define COMPRESS_POINTER(AnUint) (AnUint)
#    define EXPAND_POINTER(APointer) (APointer)
#  endif
#else
#  define HEAP_ON_C_STACK 1
#  define CHECK_POINTER_MASK 0x0UL
#  define COMPRESS_POINTER(AnUint) (AnUint)
#  define EXPAND_POINTER(APointer) (APointer)
#endif

struct erl_node_; /* Declared in erl_node_tables.h */

/*
 * Defining ET_DEBUG to 1 causes all type-specific data access
 * macros to perform runtime type checking. This is very useful
 * during development but reduces performance, so ET_DEBUG should
 * be disabled during benchmarking or release.
 */
/* #define ET_DEBUG 1 */
#ifndef ET_DEBUG
#  ifdef DEBUG
#    define ET_DEBUG 1
#  else
#    define ET_DEBUG 0
#  endif
#endif

#if ET_DEBUG
#define _ET_DECLARE_CHECKED(TF,F,TX) extern TF checked_##F(TX,const char*,unsigned);
#define _ET_APPLY(F,X)	checked_##F(X,__FILE__,__LINE__)
#else
#define _ET_DECLARE_CHECKED(TF,F,TX)
#define _ET_APPLY(F,X)	_unchecked_##F(X)
#endif

#define _TAG_PRIMARY_SIZE	2
#define _TAG_PRIMARY_MASK	0x3
#define TAG_PRIMARY_HEADER	0x0
#define TAG_PRIMARY_LIST	0x1
#define TAG_PRIMARY_BOXED	0x2
#define TAG_PRIMARY_IMMED1	0x3

#define primary_tag(x)	((x) & _TAG_PRIMARY_MASK)

#define _TAG_IMMED1_SIZE	4
#define _TAG_IMMED1_MASK	0xF
#define _TAG_IMMED1_PID		((0x0 << _TAG_PRIMARY_SIZE) | TAG_PRIMARY_IMMED1)
#define _TAG_IMMED1_PORT	((0x1 << _TAG_PRIMARY_SIZE) | TAG_PRIMARY_IMMED1)
#define _TAG_IMMED1_IMMED2	((0x2 << _TAG_PRIMARY_SIZE) | TAG_PRIMARY_IMMED1)
#define _TAG_IMMED1_SMALL	((0x3 << _TAG_PRIMARY_SIZE) | TAG_PRIMARY_IMMED1)

#define _TAG_IMMED2_SIZE	6
#define _TAG_IMMED2_MASK	0x3F
#define _TAG_IMMED2_ATOM	((0x0 << _TAG_IMMED1_SIZE) | _TAG_IMMED1_IMMED2)
#define _TAG_IMMED2_CATCH	((0x1 << _TAG_IMMED1_SIZE) | _TAG_IMMED1_IMMED2)
#define _TAG_IMMED2_NIL		((0x3 << _TAG_IMMED1_SIZE) | _TAG_IMMED1_IMMED2)

/*
 * HEADER representation:
 *
 *	aaaaaaaaaaaaaaaaaaaaaaaaaatttt00	arity:26, tag:4
 *
 * HEADER tags:
 *
 *	0000	ARITYVAL
 *      0001    BINARY_AGGREGATE                |
 *	001x	BIGNUM with sign bit		|
 *	0100	REF				|
 *	0101	FUN				| THINGS
 *	0110	FLONUM				|
 *      0111    EXPORT                          |
 *	1000	REFC_BINARY	|		|
 *	1001	HEAP_BINARY	| BINARIES	|
 *	1010	SUB_BINARY	|		|
 *      1011    Not used
 *      1100    EXTERNAL_PID  |                 |
 *      1101    EXTERNAL_PORT | EXTERNAL THINGS |
 *      1110    EXTERNAL_REF  |                 |
 *      1111    Not used
 *
 * COMMENTS:
 *
 * - The tag is zero for arityval and non-zero for thing headers.
 * - A single bit differentiates between positive and negative bignums.
 * - If more tags are needed, the REF and and EXTERNAL_REF tags could probably
 *   be combined to one tag.
 *
 * XXX: globally replace XXX_SUBTAG with TAG_HEADER_XXX
 */
#define ARITYVAL_SUBTAG		(0x0 << _TAG_PRIMARY_SIZE) /* TUPLE */
#define BIN_MATCHSTATE_SUBTAG	(0x1 << _TAG_PRIMARY_SIZE) 
#define POS_BIG_SUBTAG		(0x2 << _TAG_PRIMARY_SIZE) /* BIG: tags 2&3 */
#define NEG_BIG_SUBTAG		(0x3 << _TAG_PRIMARY_SIZE) /* BIG: tags 2&3 */
#define _BIG_SIGN_BIT		(0x1 << _TAG_PRIMARY_SIZE)
#define REF_SUBTAG		(0x4 << _TAG_PRIMARY_SIZE) /* REF */
#define FUN_SUBTAG		(0x5 << _TAG_PRIMARY_SIZE) /* FUN */
#define FLOAT_SUBTAG		(0x6 << _TAG_PRIMARY_SIZE) /* FLOAT */
#define EXPORT_SUBTAG	(0x7 << _TAG_PRIMARY_SIZE) /* FLOAT */
#define _BINARY_XXX_MASK	(0x3 << _TAG_PRIMARY_SIZE)
#define REFC_BINARY_SUBTAG	(0x8 << _TAG_PRIMARY_SIZE) /* BINARY */
#define HEAP_BINARY_SUBTAG	(0x9 << _TAG_PRIMARY_SIZE) /* BINARY */
#define SUB_BINARY_SUBTAG	(0xA << _TAG_PRIMARY_SIZE) /* BINARY */
#define EXTERNAL_PID_SUBTAG	(0xC << _TAG_PRIMARY_SIZE) /* EXTERNAL_PID */
#define EXTERNAL_PORT_SUBTAG	(0xD << _TAG_PRIMARY_SIZE) /* EXTERNAL_PORT */
#define EXTERNAL_REF_SUBTAG	(0xE << _TAG_PRIMARY_SIZE) /* EXTERNAL_REF */


#define _TAG_HEADER_ARITYVAL	(TAG_PRIMARY_HEADER|ARITYVAL_SUBTAG)
#define _TAG_HEADER_FUN		(TAG_PRIMARY_HEADER|FUN_SUBTAG)
#define _TAG_HEADER_POS_BIG	(TAG_PRIMARY_HEADER|POS_BIG_SUBTAG)
#define _TAG_HEADER_NEG_BIG	(TAG_PRIMARY_HEADER|NEG_BIG_SUBTAG)
#define _TAG_HEADER_FLOAT	(TAG_PRIMARY_HEADER|FLOAT_SUBTAG)
#define _TAG_HEADER_EXPORT	(TAG_PRIMARY_HEADER|EXPORT_SUBTAG)
#define _TAG_HEADER_REF		(TAG_PRIMARY_HEADER|REF_SUBTAG)
#define _TAG_HEADER_REFC_BIN	(TAG_PRIMARY_HEADER|REFC_BINARY_SUBTAG)
#define _TAG_HEADER_HEAP_BIN	(TAG_PRIMARY_HEADER|HEAP_BINARY_SUBTAG)
#define _TAG_HEADER_SUB_BIN	(TAG_PRIMARY_HEADER|SUB_BINARY_SUBTAG)
#define _TAG_HEADER_EXTERNAL_PID  (TAG_PRIMARY_HEADER|EXTERNAL_PID_SUBTAG)
#define _TAG_HEADER_EXTERNAL_PORT (TAG_PRIMARY_HEADER|EXTERNAL_PORT_SUBTAG)
#define _TAG_HEADER_EXTERNAL_REF  (TAG_PRIMARY_HEADER|EXTERNAL_REF_SUBTAG)
#define _TAG_HEADER_BIN_MATCHSTATE (TAG_PRIMARY_HEADER|BIN_MATCHSTATE_SUBTAG)


#define _TAG_HEADER_MASK	0x3F
#define _HEADER_SUBTAG_MASK	0x3C	/* 4 bits for subtag */
#define _HEADER_ARITY_OFFS	6

#define header_is_transparent(x) \
 (((x) & (_HEADER_SUBTAG_MASK)) == ARITYVAL_SUBTAG)
#define header_is_arityval(x)	(((x) & _HEADER_SUBTAG_MASK) == ARITYVAL_SUBTAG)
#define header_is_thing(x)	(!header_is_transparent((x)))
#define header_is_bin_matchstate(x)	((((x) & (_HEADER_SUBTAG_MASK)) == BIN_MATCHSTATE_SUBTAG))

#define _CPMASK		0x3

/* immediate object access methods */
#define is_immed(x)		(((x) & _TAG_PRIMARY_MASK) == TAG_PRIMARY_IMMED1)
#define is_not_immed(x)		(!is_immed((x)))
#define IS_CONST(x)		is_immed((x))
#if TAG_PRIMARY_IMMED1 == _TAG_PRIMARY_MASK
#define is_both_immed(x,y)	is_immed(((x)&(y)))
#else
#define is_both_immed(x,y)	(is_immed((x)) && is_immed((y)))
#endif
#define is_not_both_immed(x,y)	(!is_both_immed((x),(y)))


/* boxed object access methods */
#if HALFWORD_HEAP
#define _is_taggable_pointer(x)	 (((UWord)(x) & (CHECK_POINTER_MASK | 0x3)) == 0)
#define _boxed_precond(x)        (is_boxed(x))
#else
#define _is_taggable_pointer(x)	 (((Uint)(x) & 0x3) == 0)
#define  _boxed_precond(x)       (is_boxed(x))
#endif
#define _is_aligned(x)		(((Uint)(x) & 0x3) == 0)
#define _unchecked_make_boxed(x) ((Uint) COMPRESS_POINTER(x) + TAG_PRIMARY_BOXED)
_ET_DECLARE_CHECKED(Eterm,make_boxed,Eterm*);
#define make_boxed(x)		_ET_APPLY(make_boxed,(x))
#if 1
#define _is_not_boxed(x)	((x) & (_TAG_PRIMARY_MASK-TAG_PRIMARY_BOXED))
#define _unchecked_is_boxed(x)	(!_is_not_boxed((x)))
_ET_DECLARE_CHECKED(int,is_boxed,Eterm)
#define is_boxed(x)		_ET_APPLY(is_boxed,(x))
#else
#define is_boxed(x)		(((x) & _TAG_PRIMARY_MASK) == TAG_PRIMARY_BOXED)
#endif
#define _unchecked_boxed_val(x) ((Eterm*) EXPAND_POINTER(((x) - TAG_PRIMARY_BOXED)))
_ET_DECLARE_CHECKED(Eterm*,boxed_val,Eterm);
#define boxed_val(x)		_ET_APPLY(boxed_val,(x))

/* cons cell ("list") access methods */
#define _unchecked_make_list(x)	((Uint) COMPRESS_POINTER(x) + TAG_PRIMARY_LIST)
_ET_DECLARE_CHECKED(Eterm,make_list,Eterm*);
#define make_list(x)		_ET_APPLY(make_list,(x))
#if 1
#define _unchecked_is_not_list(x) ((x) & (_TAG_PRIMARY_MASK-TAG_PRIMARY_LIST))
_ET_DECLARE_CHECKED(int,is_not_list,Eterm)
#define is_not_list(x)		_ET_APPLY(is_not_list,(x))
#define is_list(x)		(!is_not_list((x)))
#else
#define is_list(x)		(((x) & _TAG_PRIMARY_MASK) == TAG_PRIMARY_LIST)
#define is_not_list(x)		(!is_list((x)))
#endif
#if HALFWORD_HEAP
#define _list_precond(x)        (is_list(x))
#else
#define _list_precond(x)       (is_list(x))
#endif
#define _unchecked_list_val(x) ((Eterm*) EXPAND_POINTER((x) - TAG_PRIMARY_LIST))
_ET_DECLARE_CHECKED(Eterm*,list_val,Eterm);
#define list_val(x)		_ET_APPLY(list_val,(x))

#define CONS(hp, car, cdr) \
        (CAR(hp)=(car), CDR(hp)=(cdr), make_list(hp))

#define CAR(x)  ((x)[0])
#define CDR(x)  ((x)[1])

/* generic tagged pointer (boxed or list) access methods */
#define _unchecked_ptr_val(x)	((Eterm*) EXPAND_POINTER((x) & ~((Uint) 0x3)))
#define ptr_val(x)		_unchecked_ptr_val((x))	/*XXX*/
#define _unchecked_offset_ptr(x,offs)	((x)+((offs)*sizeof(Eterm)))
#define offset_ptr(x,offs)	_unchecked_offset_ptr(x,offs)	/*XXX*/

/* fixnum ("small") access methods */
#if defined(ARCH_64) && !HALFWORD_HEAP
#define SMALL_BITS	(64-4)
#define SMALL_DIGITS	(17)
#else
#define SMALL_BITS	(28)
#define SMALL_DIGITS	(8)
#endif
#define MAX_SMALL	((1L << (SMALL_BITS-1))-1)
#define MIN_SMALL	(-(1L << (SMALL_BITS-1)))
#define make_small(x)	(((Uint)(x) << _TAG_IMMED1_SIZE) + _TAG_IMMED1_SMALL)
#define is_small(x)	(((x) & _TAG_IMMED1_MASK) == _TAG_IMMED1_SMALL)
#define is_not_small(x)	(!is_small((x)))
#define is_byte(x)	(((x) & ((~(Uint)0 << (_TAG_IMMED1_SIZE+8)) + _TAG_IMMED1_MASK)) == _TAG_IMMED1_SMALL)
#define is_valid_bit_size(x) (((Sint)(x)) >= 0 && ((x) & 0x7F) == _TAG_IMMED1_SMALL)
#define is_not_valid_bit_size(x) (!is_valid_bit_size((x)))
#define MY_IS_SSMALL(x) (((Uint) (((x) >> (SMALL_BITS-1)) + 1)) < 2)
#define _unchecked_unsigned_val(x)	((x) >> _TAG_IMMED1_SIZE)
_ET_DECLARE_CHECKED(Uint,unsigned_val,Eterm)
#define unsigned_val(x)	_ET_APPLY(unsigned_val,(x))
#define _unchecked_signed_val(x)	((Sint)(x) >> _TAG_IMMED1_SIZE)
_ET_DECLARE_CHECKED(Sint,signed_val,Eterm)
#define signed_val(x)	_ET_APPLY(signed_val,(x))

#if _TAG_IMMED1_SMALL == 0x0F
#define is_both_small(x,y) (((x) & (y) & _TAG_IMMED1_MASK) == _TAG_IMMED1_SMALL)
#elif _TAG_IMMED1_SMALL == 0x00
#define is_both_small(x,y) ((((x)|(y)) & _TAG_IMMED1_MASK) == _TAG_IMMED1_SMALL)
#else
#define is_both_small(x,y) (is_small(x) && is_small(y))
#endif

/* NIL access methods */
#define NIL		((~((Uint) 0) << _TAG_IMMED2_SIZE) | _TAG_IMMED2_NIL)
#define is_nil(x)	((x) == NIL)
#define is_not_nil(x)	((x) != NIL)

#define MAX_ATOM_INDEX (~(~((Uint) 0) << (sizeof(Uint)*8 - _TAG_IMMED2_SIZE)))

/* atom access methods */
#define make_atom(x)  ((Eterm)(((x) << _TAG_IMMED2_SIZE) + _TAG_IMMED2_ATOM))
#define is_atom(x)	(((x) & _TAG_IMMED2_MASK) == _TAG_IMMED2_ATOM)
#define is_not_atom(x)	(!is_atom(x))
#define _unchecked_atom_val(x)	((x) >> _TAG_IMMED2_SIZE)
_ET_DECLARE_CHECKED(Uint,atom_val,Eterm)
#define atom_val(x)	_ET_APPLY(atom_val,(x))

/* header (arityval or thing) access methods */
#define _make_header(sz,tag)  ((Uint)(((sz) << _HEADER_ARITY_OFFS) + (tag)))
#define is_header(x)	(((x) & _TAG_PRIMARY_MASK) == TAG_PRIMARY_HEADER)
#define _unchecked_header_arity(x)	((x) >> _HEADER_ARITY_OFFS)
_ET_DECLARE_CHECKED(Uint,header_arity,Eterm)
#define header_arity(x)	_ET_APPLY(header_arity,(x))

/* arityval access methods */
#define make_arityval(sz)	_make_header((sz),_TAG_HEADER_ARITYVAL)
#define is_arity_value(x)	(((x) & _TAG_HEADER_MASK) == _TAG_HEADER_ARITYVAL)
#define is_not_arity_value(x)	(!is_arity_value((x)))
#define _unchecked_arityval(x)	_unchecked_header_arity((x))
_ET_DECLARE_CHECKED(Uint,arityval,Eterm)
#define arityval(x)		_ET_APPLY(arityval,(x))

/* thing access methods */
#define is_thing(x)	(is_header((x)) && header_is_thing((x)))
#define _unchecked_thing_arityval(x)	_unchecked_header_arity((x))
_ET_DECLARE_CHECKED(Uint,thing_arityval,Eterm)
#define thing_arityval(x)	_ET_APPLY(thing_arityval,(x))
#define _unchecked_thing_subtag(x)	((x) & _HEADER_SUBTAG_MASK)
_ET_DECLARE_CHECKED(Uint,thing_subtag,Eterm)
#define thing_subtag(x)		_ET_APPLY(thing_subtag,(x))

/*
 * Magic non-value object.
 * Used as function return error and "absent value" indicator
 * in the original runtime system. The new runtime system also
 * uses it as forwarding marker for CONS cells.
 *
 * This value is 0 in the original runtime system, which unfortunately
 * promotes sloppy programming practices. It also prevents some useful
 * tag assignment schemes, e.g. using a 2-bit tag 00 for FIXNUM.
 *
 * To help find code which makes unwarranted assumptions about zero,
 * we now use a non-zero bit-pattern in debug mode.
 */
#if ET_DEBUG
#define THE_NON_VALUE	_make_header(0,_TAG_HEADER_FLOAT)
#else
#define THE_NON_VALUE	(0)
#endif
#define is_non_value(x)	((x) == THE_NON_VALUE)
#define is_value(x)	((x) != THE_NON_VALUE)

/* binary object access methods */
#define is_binary_header(x)	(((x) & (_TAG_HEADER_MASK-_BINARY_XXX_MASK)) == _TAG_HEADER_REFC_BIN)
#define make_binary(x)	make_boxed((Eterm*)(x))
#define is_binary(x)	(is_boxed((x)) && is_binary_header(*boxed_val((x))))
#define is_not_binary(x) (!is_binary((x)))
#define _unchecked_binary_val(x) _unchecked_boxed_val((x))
_ET_DECLARE_CHECKED(Eterm*,binary_val,Eterm)
#define binary_val(x)	_ET_APPLY(binary_val,(x))

/* process binaries stuff (special case of binaries) */
#define HEADER_PROC_BIN	_make_header(PROC_BIN_SIZE-1,_TAG_HEADER_REFC_BIN)

/* fun & export objects */
#define is_any_fun(x)   (is_fun((x)) || is_export((x)))
#define is_not_any_fun(x) (!is_any_fun((x)))

/* fun objects */
#define HEADER_FUN		_make_header(ERL_FUN_SIZE-2,_TAG_HEADER_FUN)
#define is_fun_header(x)	((x) == HEADER_FUN)
#define make_fun(x)		make_boxed((Eterm*)(x))
#define is_fun(x)		(is_boxed((x)) && is_fun_header(*boxed_val((x))))
#define is_not_fun(x)		(!is_fun((x)))
#define _unchecked_fun_val(x)   _unchecked_boxed_val((x))
_ET_DECLARE_CHECKED(Eterm*,fun_val,Eterm)
#define fun_val(x)		_ET_APPLY(fun_val,(x))

/* export access methods */
#define make_export(x)	 make_boxed((x))
#define is_export(x)     (is_boxed((x)) && is_export_header(*boxed_val((x))))
#define is_not_export(x) (!is_export((x)))
#define _unchecked_export_val(x)   _unchecked_boxed_val(x)
_ET_DECLARE_CHECKED(Eterm*,export_val,Eterm)
#define export_val(x)	_ET_APPLY(export_val,(x))
#define is_export_header(x)	((x) == HEADER_EXPORT)
#if HALFWORD_HEAP
#define HEADER_EXPORT   _make_header(2,_TAG_HEADER_EXPORT)
#else
#define HEADER_EXPORT   _make_header(1,_TAG_HEADER_EXPORT)
#endif

/* bignum access methods */
#define make_pos_bignum_header(sz)	_make_header((sz),_TAG_HEADER_POS_BIG)
#define make_neg_bignum_header(sz)	_make_header((sz),_TAG_HEADER_NEG_BIG)
#define _is_bignum_header(x)	(((x) & (_TAG_HEADER_MASK-_BIG_SIGN_BIT)) == _TAG_HEADER_POS_BIG)
#define _unchecked_bignum_header_is_neg(x)	((x) & _BIG_SIGN_BIT)
_ET_DECLARE_CHECKED(int,bignum_header_is_neg,Eterm)
#define bignum_header_is_neg(x)	_ET_APPLY(bignum_header_is_neg,(x))
#define _unchecked_bignum_header_neg(x)	((x) | _BIG_SIGN_BIT)
_ET_DECLARE_CHECKED(Eterm,bignum_header_neg,Eterm)
#define bignum_header_neg(x)	_ET_APPLY(bignum_header_neg,(x))
#define _unchecked_bignum_header_arity(x)	_unchecked_header_arity((x))
_ET_DECLARE_CHECKED(Uint,bignum_header_arity,Eterm)
#define bignum_header_arity(x)	_ET_APPLY(bignum_header_arity,(x))
#define BIG_ARITY_MAX		((1 << 19)-1)
#define make_big(x)	make_boxed((x))
#define is_big(x)	(is_boxed((x)) && _is_bignum_header(*boxed_val((x))))
#define is_not_big(x)	(!is_big((x)))
#define _unchecked_big_val(x)	_unchecked_boxed_val((x))
_ET_DECLARE_CHECKED(Eterm*,big_val,Eterm)
#define big_val(x)		_ET_APPLY(big_val,(x))

/* flonum ("float") access methods */
#if defined(ARCH_64) && !HALFWORD_HEAP
#define HEADER_FLONUM   _make_header(1,_TAG_HEADER_FLOAT)
#else
#define HEADER_FLONUM	_make_header(2,_TAG_HEADER_FLOAT)
#endif
#define make_float(x)	make_boxed((x))
#define is_float(x)	(is_boxed((x)) && *boxed_val((x)) == HEADER_FLONUM)
#define is_not_float(x)	(!is_float(x))
#define _unchecked_float_val(x)	_unchecked_boxed_val((x))
_ET_DECLARE_CHECKED(Eterm*,float_val,Eterm)
#define float_val(x)	_ET_APPLY(float_val,(x))

/* Float definition for byte and word access */
typedef double ieee754_8;

typedef union float_def
{
    ieee754_8 fd;
    byte   fb[sizeof(ieee754_8)];
    Uint16 fs[sizeof(ieee754_8) / sizeof(Uint16)];
    Uint32 fw[sizeof(ieee754_8) / sizeof(Uint32)];
#if defined(ARCH_64) && !HALFWORD_HEAP
    Uint   fdw;
#endif
} FloatDef;

#if defined(ARCH_64) && !HALFWORD_HEAP
#define GET_DOUBLE(x, f) (f).fdw = *(float_val(x)+1)

#define PUT_DOUBLE(f, x)  *(x) = HEADER_FLONUM, \
                          *((x)+1) = (f).fdw
#define GET_DOUBLE_DATA(p, f) (f).fdw = *((Uint *) (p))
#define PUT_DOUBLE_DATA(f,p) *((Uint *) (p)) = (f).fdw
#else
#define GET_DOUBLE(x, f) (f).fw[0] = *(float_val(x)+1), \
                         (f).fw[1] = *(float_val(x)+2)

#define PUT_DOUBLE(f, x)  *(x) = HEADER_FLONUM, \
                          *((x)+1) = (f).fw[0], \
			  *((x)+2) = (f).fw[1]
#define GET_DOUBLE_DATA(p, f) (f).fw[0] = *((Uint *) (p)),\
                              (f).fw[1] = *(((Uint *) (p))+1)
#define PUT_DOUBLE_DATA(f,p) *((Uint *) (p)) = (f).fw[0],\
                             *(((Uint *) (p))+1) = (f).fw[1]
#endif
#define DOUBLE_DATA_WORDS (sizeof(ieee754_8)/sizeof(Eterm))
#define FLOAT_SIZE_OBJECT (DOUBLE_DATA_WORDS+1)

/* tuple access methods */
#define make_tuple(x)	make_boxed((x))
#define is_tuple(x)	(is_boxed((x)) && is_arity_value(*boxed_val((x))))
#define is_not_tuple(x)	(!is_tuple((x)))
#define is_tuple_arity(x, a) \
   (is_boxed((x)) && *boxed_val((x)) == make_arityval((a)))
#define is_not_tuple_arity(x, a) (!is_tuple_arity((x),(a)))
#define _unchecked_tuple_val(x)	_unchecked_boxed_val(x)
_ET_DECLARE_CHECKED(Eterm*,tuple_val,Eterm)
#define tuple_val(x)	_ET_APPLY(tuple_val,(x))

#define TUPLE0(t) \
        ((t)[0] = make_arityval(0), \
        make_tuple(t))
#define TUPLE1(t,e1) \
        ((t)[0] = make_arityval(1), \
        (t)[1] = (e1), \
        make_tuple(t))
#define TUPLE2(t,e1,e2) \
        ((t)[0] = make_arityval(2), \
        (t)[1] = (e1), \
        (t)[2] = (e2), \
        make_tuple(t))
#define TUPLE3(t,e1,e2,e3) \
        ((t)[0] = make_arityval(3), \
        (t)[1] = (e1), \
        (t)[2] = (e2), \
        (t)[3] = (e3), \
        make_tuple(t))
#define TUPLE4(t,e1,e2,e3,e4) \
        ((t)[0] = make_arityval(4), \
        (t)[1] = (e1), \
        (t)[2] = (e2), \
        (t)[3] = (e3), \
        (t)[4] = (e4), \
        make_tuple(t))
#define TUPLE5(t,e1,e2,e3,e4,e5) \
        ((t)[0] = make_arityval(5), \
        (t)[1] = (e1), \
        (t)[2] = (e2), \
        (t)[3] = (e3), \
        (t)[4] = (e4), \
        (t)[5] = (e5), \
        make_tuple(t))
#define TUPLE6(t,e1,e2,e3,e4,e5,e6) \
        ((t)[0] = make_arityval(6), \
        (t)[1] = (e1), \
        (t)[2] = (e2), \
        (t)[3] = (e3), \
        (t)[4] = (e4), \
        (t)[5] = (e5), \
	(t)[6] = (e6), \
        make_tuple(t))

#define TUPLE7(t,e1,e2,e3,e4,e5,e6,e7) \
        ((t)[0] = make_arityval(7), \
        (t)[1] = (e1), \
        (t)[2] = (e2), \
        (t)[3] = (e3), \
        (t)[4] = (e4), \
        (t)[5] = (e5), \
	(t)[6] = (e6), \
	(t)[7] = (e7), \
        make_tuple(t))

#define TUPLE8(t,e1,e2,e3,e4,e5,e6,e7,e8) \
        ((t)[0] = make_arityval(8), \
        (t)[1] = (e1), \
        (t)[2] = (e2), \
        (t)[3] = (e3), \
        (t)[4] = (e4), \
        (t)[5] = (e5), \
	(t)[6] = (e6), \
	(t)[7] = (e7), \
	(t)[8] = (e8), \
        make_tuple(t))

/* This macro get Size bits starting at low order position Pos
   and adjusts the bits to the right 
   bits are numbered from 0 - (sizeof(Uint)*8-1) */

#define _GETBITS(X,Pos,Size) (((X) >> (Pos)) & ~(~((Uint) 0) << (Size)))

/*
 * Observe! New layout for pids, ports and references in R9 (see also note
 * in erl_node_container_utils.h).
 */


/*
 * Creation in node specific data (pids, ports, refs)
 */

#define _CRE_SIZE  		2

/* MAX value for the creation field in pid, port and reference */
#define MAX_CREATION	(1 << _CRE_SIZE)

/*
 *  PID layout (internal pids):
 *
 *   |3 3 2 2 2 2 2 2|2 2 2 2 1 1 1 1|1 1 1 1 1 1    |               |
 *   |1 0 9 8 7 6 5 4|3 2 1 0 9 8 7 6|5 4 3 2 1 0 9 8|7 6 5 4 3 2 1 0|
 *   |               |               |               |               |
 *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *   |n n n n n n n n n n n n n n n n n n n n n n n n n n n n|0 0|1 1|
 *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 *  n : number
 *
 *  Old pid layout:
 *
 *   |3 3 2 2 2 2 2 2|2 2 2 2 1 1 1 1|1 1 1 1 1 1    |               |
 *   |1 0 9 8 7 6 5 4|3 2 1 0 9 8 7 6|5 4 3 2 1 0 9 8|7 6 5 4 3 2 1 0|
 *   |               |               |               |               |
 *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *   |s s s|n n n n n n n n n n n n n n n|N N N N N N N N|c c|0 0|1 1|
 *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 *  s : serial
 *  n : number
 *  c : creation
 *  N : node number
 *
 */

#define _PID_R9_SER_SIZE	3
#define _PID_SER_SIZE		(_PID_DATA_SIZE - _PID_NUM_SIZE)
#define _PID_NUM_SIZE 		15

#define _PID_DATA_SIZE		28
#define _PID_DATA_SHIFT		(_TAG_IMMED1_SIZE)

#define _GET_PID_DATA(X)	_GETBITS((X),_PID_DATA_SHIFT,_PID_DATA_SIZE)
#define _GET_PID_NUM(X)		_GETBITS((X),0,_PID_NUM_SIZE)
#define _GET_PID_SER(X)		_GETBITS((X),_PID_NUM_SIZE,_PID_SER_SIZE)

#define make_pid_data(Ser, Num) \
  ((Uint) ((Ser) << _PID_NUM_SIZE | (Num)))

#define make_internal_pid(X) \
  ((Eterm) (((X) << _PID_DATA_SHIFT) | _TAG_IMMED1_PID))

#define is_internal_pid(x)	(((x) & _TAG_IMMED1_MASK) == _TAG_IMMED1_PID)
#define is_not_internal_pid(x)	(!is_internal_pid((x)))

#define _unchecked_internal_pid_data(x) _GET_PID_DATA((x))
_ET_DECLARE_CHECKED(Uint,internal_pid_data,Eterm)
#define internal_pid_data(x) _ET_APPLY(internal_pid_data,(x))

#define _unchecked_internal_pid_node(x) erts_this_node
_ET_DECLARE_CHECKED(struct erl_node_*,internal_pid_node,Eterm)
#define internal_pid_node(x) _ET_APPLY(internal_pid_node,(x))

#define internal_pid_number(x) _GET_PID_NUM(internal_pid_data((x)))
#define internal_pid_serial(x) _GET_PID_SER(internal_pid_data((x)))

#define internal_pid_data_words(x) (1)

/* 
 *  PORT layout (internal ports):
 *
 *  |3 3 2 2 2 2 2 2|2 2 2 2 1 1 1 1|1 1 1 1 1 1    |               |
 *  |1 0 9 8 7 6 5 4|3 2 1 0 9 8 7 6|5 4 3 2 1 0 9 8|7 6 5 4 3 2 1 0|
 *  |               |               |               |               |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |n n n n n n n n n n n n n n n n n n n n n n n n n n n n|0 1|1 1|
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 *  n : number
 *
 * Old port layout:
 *
 *  |3 3 2 2 2 2 2 2|2 2 2 2 1 1 1 1|1 1 1 1 1 1    |               |
 *  |1 0 9 8 7 6 5 4|3 2 1 0 9 8 7 6|5 4 3 2 1 0 9 8|7 6 5 4 3 2 1 0|
 *  |               |               |               |               |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |N N N N N N N N|n n n n n n n n n n n n n n n n n n|c c|0 1|1 1|
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 *  s : serial
 *  n : number
 *  c : creation
 *  N : node number
 *
 */
#define _PORT_R9_NUM_SIZE	18
#define _PORT_NUM_SIZE		_PORT_DATA_SIZE

#define _PORT_DATA_SIZE		28
#define _PORT_DATA_SHIFT	(_TAG_IMMED1_SIZE)

#define _GET_PORT_DATA(X)	_GETBITS((X),_PORT_DATA_SHIFT,_PORT_DATA_SIZE)
#define _GET_PORT_NUM(X)	_GETBITS((X), 0, _PORT_NUM_SIZE)


#define make_internal_port(X) \
  ((Eterm) (((X) << _PORT_DATA_SHIFT) | _TAG_IMMED1_PORT))

#define is_internal_port(x)	(((x) & _TAG_IMMED1_MASK) == _TAG_IMMED1_PORT)
#define is_not_internal_port(x)	(!is_internal_port(x))

#define _unchecked_internal_port_data(x) _GET_PORT_DATA((x))
_ET_DECLARE_CHECKED(Uint,internal_port_data,Eterm)
#define internal_port_data(x) _ET_APPLY(internal_port_data,(x))

#define internal_port_number(x) _GET_PORT_NUM(internal_port_data((x)))

#define _unchecked_internal_port_node(x) erts_this_node
_ET_DECLARE_CHECKED(struct erl_node_*,internal_port_node,Eterm)
#define internal_port_node(x) _ET_APPLY(internal_port_node,(x))

#define internal_port_data_words(x) (1)
/*
 *  Ref layout (internal references):
 *
 *  |3 3 2 2 2 2 2 2|2 2 2 2 1 1 1 1|1 1 1 1 1 1    |               |
 *  |1 0 9 8 7 6 5 4|3 2 1 0 9 8 7 6|5 4 3 2 1 0 9 8|7 6 5 4 3 2 1 0|
 *  |               |               |               |               |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1|0 1 0 0|0 0| Thing
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |0 0 0 0 0 0 0 0 0 0 0 0 0 0|r r r r r r r r r r r r r r r r r r| Data 0
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r| Data 1
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r| Data 2
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 *
 *  r : reference number
 *  c : creation
 *
 *
 * Old "heap ref" layout:
 *
 *
 *  |3 3 2 2 2 2 2 2|2 2 2 2 1 1 1 1|1 1 1 1 1 1    |               |
 *  |1 0 9 8 7 6 5 4|3 2 1 0 9 8 7 6|5 4 3 2 1 0 9 8|7 6 5 4 3 2 1 0|
 *  |               |               |               |               |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1|0 1 0 0|0 0| Thing
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |N N N N N N N N|0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0|c c|0 1 1 1| Head
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |0 0 0 0 0 0 0 0 0 0 0 0 0 0|r r r r r r r r r r r r r r r r r r| Word 0
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r| Word 1
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r| Word 2
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 *  r : reference number
 *  c : creation
 *  N : node index
 *
 * Old "one-word ref" layout:
 *
 *  |3 3 2 2 2 2 2 2|2 2 2 2 1 1 1 1|1 1 1 1 1 1    |               |
 *  |1 0 9 8 7 6 5 4|3 2 1 0 9 8 7 6|5 4 3 2 1 0 9 8|7 6 5 4 3 2 1 0|
 *  |               |               |               |               |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |N N N N N N N N|r r r r r r r r r r r r r r r r r r|c c|T T T T|
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 *  r : reference number
 *  c : creation
 *  N : node index
 *
 */
#define _REF_NUM_SIZE		18

/* Old maximum number of references in the system */
#define MAX_REFERENCE		(1 << _REF_NUM_SIZE)
#define REF_MASK		(~(~((Uint)0) << _REF_NUM_SIZE))
#define ERTS_MAX_REF_NUMBERS	3
#define ERTS_REF_NUMBERS	ERTS_MAX_REF_NUMBERS

#if defined(ARCH_64) && !HALFWORD_HEAP
#  define ERTS_REF_WORDS	(ERTS_REF_NUMBERS/2 + 1)
#  define ERTS_REF_32BIT_WORDS  (ERTS_REF_NUMBERS+1)
#else
#  define ERTS_REF_WORDS	ERTS_REF_NUMBERS
#  define ERTS_REF_32BIT_WORDS  ERTS_REF_NUMBERS
#endif

typedef struct {
    Eterm      header;
    union {
	Uint32 ui32[ERTS_REF_32BIT_WORDS];
	Uint   ui[ERTS_REF_WORDS];
    } data;
} RefThing;

#define REF_THING_SIZE (sizeof(RefThing)/sizeof(Uint))
#define REF_THING_HEAD_SIZE (sizeof(Eterm)/sizeof(Uint))

#define make_ref_thing_header(DW) \
  _make_header((DW)+REF_THING_HEAD_SIZE-1,_TAG_HEADER_REF)

#if defined(ARCH_64) && !HALFWORD_HEAP

/*
 * Ref layout on a 64-bit little endian machine:
 *
 * 63             31             0
 * +--------------+--------------+
 * |         Thing word          |
 * +--------------+--------------+
 * |  Data 0      | 32-bit arity |
 * +--------------+--------------+
 * |  Data 2      | Data 1       |
 * +--------------+--------------+
 *
 * Data is stored as an Uint32 array with 32-bit arity as first number.
 */

#define write_ref_thing(Hp, R0, R1, R2)					\
do {									\
  ((RefThing *) (Hp))->header  = make_ref_thing_header(ERTS_REF_WORDS);	\
  ((RefThing *) (Hp))->data.ui32[0] = ERTS_REF_NUMBERS;			\
  ((RefThing *) (Hp))->data.ui32[1] = (R0);				\
  ((RefThing *) (Hp))->data.ui32[2] = (R1);				\
  ((RefThing *) (Hp))->data.ui32[3] = (R2);				\
} while (0)

#else

#define write_ref_thing(Hp, R0, R1, R2)					\
do {									\
  ((RefThing *) (Hp))->header  = make_ref_thing_header(ERTS_REF_WORDS);	\
  ((RefThing *) (Hp))->data.ui32[0] = (R0);				\
  ((RefThing *) (Hp))->data.ui32[1] = (R1);				\
  ((RefThing *) (Hp))->data.ui32[2] = (R2);				\
} while (0)

#endif

#define is_ref_thing_header(x)	(((x) & _TAG_HEADER_MASK) == _TAG_HEADER_REF)
#define make_internal_ref(x)	make_boxed((Eterm*)(x))

#define _unchecked_ref_thing_ptr(x) \
  ((RefThing*) _unchecked_internal_ref_val(x))
#define ref_thing_ptr(x) \
  ((RefThing*) internal_ref_val(x))

#define is_internal_ref(x) \
  (_unchecked_is_boxed((x)) && is_ref_thing_header(*boxed_val((x))))
#define is_not_internal_ref(x) \
  (!is_internal_ref((x)))

#define _unchecked_internal_ref_val(x) _unchecked_boxed_val((x))
_ET_DECLARE_CHECKED(Eterm*,internal_ref_val,Eterm)
#define internal_ref_val(x) _ET_APPLY(internal_ref_val,(x))

#define _unchecked_internal_ref_data_words(x) \
 (_unchecked_thing_arityval(*_unchecked_internal_ref_val(x)))
_ET_DECLARE_CHECKED(Uint,internal_ref_data_words,Eterm)
#define internal_ref_data_words(x) _ET_APPLY(internal_ref_data_words,(x))

#define _unchecked_internal_ref_data(x) (_unchecked_ref_thing_ptr(x)->data.ui32)
_ET_DECLARE_CHECKED(Uint32*,internal_ref_data,Eterm)
#define internal_ref_data(x) _ET_APPLY(internal_ref_data,(x))

#define _unchecked_internal_ref_node(x) erts_this_node
_ET_DECLARE_CHECKED(struct erl_node_*,internal_ref_node,Eterm)
#define internal_ref_node(x) _ET_APPLY(internal_ref_node,(x))

/*
 *
 *  External thing layout (external pids, ports, and refs):
 *
 *  |3 3 2 2 2 2 2 2|2 2 2 2 1 1 1 1|1 1 1 1 1 1    |               |
 *  |1 0 9 8 7 6 5 4|3 2 1 0 9 8 7 6|5 4 3 2 1 0 9 8|7 6 5 4 3 2 1 0|
 *  |               |               |               |               |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |A A A A A A A A A A A A A A A A A A A A A A A A A A|t t t t|0 0| Thing
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N| Next
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E| ErlNode
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X| Data 0
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  .                                                               .   .
 *  .                                                               .   .
 *  .                                                               .   .
 *
 *  A : Arity
 *  t : External pid thing tag  (1100)
 *  t : External port thing tag (1101)
 *  t : External ref thing tag  (1110)
 *  N : Next (external thing) pointer
 *  E : ErlNode pointer
 *  X : Type specific data
 *
 *  External pid and port layout:
 *    External pids and ports only have one data word (Data 0) which has
 *    the same layout as internal pids resp. internal ports.
 *
 *  External refs layout:
 *    External refs has the same layout for the data words as in the internal
 *    ref. 
 *
 */

typedef struct external_thing_ {
    /*                                 ----+                        */
    Eterm                   header;     /* |                        */
    struct external_thing_ *next;       /*  > External thing head   */
    struct erl_node_       *node;       /* |                        */
    /*                                 ----+                        */
    union {
	Uint32              ui32[1];
	Uint                ui[1];
    } data;
} ExternalThing;

#define EXTERNAL_THING_HEAD_SIZE (sizeof(ExternalThing)/sizeof(Uint) - 1)

#define make_external_pid_header(DW) \
  _make_header((DW)+EXTERNAL_THING_HEAD_SIZE-1,_TAG_HEADER_EXTERNAL_PID)
#define is_external_pid_header(x) \
  (((x) & _TAG_HEADER_MASK) == _TAG_HEADER_EXTERNAL_PID)

#define make_external_port_header(DW) \
  _make_header((DW)+EXTERNAL_THING_HEAD_SIZE-1,_TAG_HEADER_EXTERNAL_PORT)
#define is_external_port_header(x) \
  (((x) & _TAG_HEADER_MASK) == _TAG_HEADER_EXTERNAL_PORT)

#define make_external_ref_header(DW) \
  _make_header((DW)+EXTERNAL_THING_HEAD_SIZE-1,_TAG_HEADER_EXTERNAL_REF)
#define is_external_ref_header(x) \
  (((x) & _TAG_HEADER_MASK) == _TAG_HEADER_EXTERNAL_REF)

#define is_external_header(x) \
  (((x) & (_TAG_HEADER_MASK-_BINARY_XXX_MASK)) == _TAG_HEADER_EXTERNAL_PID)

#define is_external(x) \
  (is_boxed((x)) && is_external_header(*boxed_val((x))))
#define is_external_pid(x) \
  (is_boxed((x)) && is_external_pid_header(*boxed_val((x))))
#define is_external_port(x) \
  (is_boxed((x)) && is_external_port_header(*boxed_val((x))))
#define is_external_ref(x) \
  (_unchecked_is_boxed((x)) && is_external_ref_header(*boxed_val((x))))

#define _unchecked_is_external(x) \
  (_unchecked_is_boxed((x)) && is_external_header(*_unchecked_boxed_val((x))))

#define is_not_external(x)	(!is_external((x)))
#define is_not_external_pid(x)	(!is_external_pid((x)))
#define is_not_external_port(x)	(!is_external_port((x)))
#define is_not_external_ref(x)	(!is_external_ref((x)))


#define make_external(x)		make_boxed((Eterm *) (x))

#define make_external_pid		make_external
#define make_external_port		make_external
#define make_external_ref		make_external

#define _unchecked_external_val(x) _unchecked_boxed_val((x))
_ET_DECLARE_CHECKED(Eterm*,external_val,Eterm)
#define external_val(x) _ET_APPLY(external_val,(x))

#define external_thing_ptr(x) ((ExternalThing *) external_val((x)))
#define _unchecked_external_thing_ptr(x) \
  ((ExternalThing *) _unchecked_external_val((x)))

#define _unchecked_external_data_words(x) \
  (_unchecked_thing_arityval(_unchecked_external_thing_ptr((x))->header) \
   + (1 - EXTERNAL_THING_HEAD_SIZE))
_ET_DECLARE_CHECKED(Uint,external_data_words,Eterm)
#define external_data_words(x) _ET_APPLY(external_data_words,(x))

#define _unchecked_external_data(x) (_unchecked_external_thing_ptr((x))->data.ui)
#define _unchecked_external_node(x) (_unchecked_external_thing_ptr((x))->node)

#define external_data(x) (external_thing_ptr((x))->data.ui)
#define external_node(x) (external_thing_ptr((x))->node)

#define _unchecked_external_pid_data_words(x) \
  _unchecked_external_data_words((x))
_ET_DECLARE_CHECKED(Uint,external_pid_data_words,Eterm)
#define external_pid_data_words(x) _ET_APPLY(external_pid_data_words,(x))

#define _unchecked_external_pid_data(x) _unchecked_external_data((x))[0]
_ET_DECLARE_CHECKED(Uint,external_pid_data,Eterm)
#define external_pid_data(x) _ET_APPLY(external_pid_data,(x))

#define _unchecked_external_pid_node(x) _unchecked_external_node((x))
_ET_DECLARE_CHECKED(struct erl_node_*,external_pid_node,Eterm)
#define external_pid_node(x) _ET_APPLY(external_pid_node,(x))

#define external_pid_number(x) _GET_PID_NUM(external_pid_data((x)))
#define external_pid_serial(x) _GET_PID_SER(external_pid_data((x)))

#define _unchecked_external_port_data_words(x) \
  _unchecked_external_data_words((x))
_ET_DECLARE_CHECKED(Uint,external_port_data_words,Eterm)
#define external_port_data_words(x) _ET_APPLY(external_port_data_words,(x))

#define _unchecked_external_port_data(x) _unchecked_external_data((x))[0]
_ET_DECLARE_CHECKED(Uint,external_port_data,Eterm)
#define external_port_data(x) _ET_APPLY(external_port_data,(x))

#define _unchecked_external_port_node(x) _unchecked_external_node((x))
_ET_DECLARE_CHECKED(struct erl_node_*,external_port_node,Eterm)
#define external_port_node(x) _ET_APPLY(external_port_node,(x))

#define external_port_number(x) _GET_PORT_NUM(external_port_data((x)))

#define _unchecked_external_ref_data_words(x) \
  _unchecked_external_data_words((x))
_ET_DECLARE_CHECKED(Uint,external_ref_data_words,Eterm)
#define external_ref_data_words(x) _ET_APPLY(external_ref_data_words,(x))

#define _unchecked_external_ref_data(x) (_unchecked_external_thing_ptr((x))->data.ui32)
_ET_DECLARE_CHECKED(Uint32*,external_ref_data,Eterm)
#define external_ref_data(x) _ET_APPLY(external_ref_data,(x))

#define _unchecked_external_ref_node(x) _unchecked_external_node((x))
_ET_DECLARE_CHECKED(struct erl_node_*,external_ref_node,Eterm)
#define external_ref_node(x) _ET_APPLY(external_ref_node,(x))

/* number tests */

#define is_integer(x)		(is_small(x) || is_big(x))
#define is_not_integer(x)	(!is_integer(x))
#define is_number(x)		(is_integer(x) || is_float(x))

#define SMALL_MINUS_ONE	make_small(-1)
#define SMALL_ZERO	make_small(0)
#define SMALL_ONE	make_small(1)

#define ENULL		0

/* on some architectures CP contains labels which are not aligned */
#ifdef NOT_ALIGNED
#error "fix yer arch, like"
#endif

#define _unchecked_make_cp(x)	((Eterm) COMPRESS_POINTER(x))
_ET_DECLARE_CHECKED(Eterm,make_cp,BeamInstr*);
#define make_cp(x)	_ET_APPLY(make_cp,(x))

#define is_not_CP(x)	((x) & _CPMASK)
#define is_CP(x)	(!is_not_CP(x))

#define _unchecked_cp_val(x)	((BeamInstr*) EXPAND_POINTER(x))
_ET_DECLARE_CHECKED(BeamInstr*,cp_val,Eterm);
#define cp_val(x)	_ET_APPLY(cp_val,(x))

#define make_catch(x)	(((x) << _TAG_IMMED2_SIZE) | _TAG_IMMED2_CATCH)
#define is_catch(x)	(((x) & _TAG_IMMED2_MASK) == _TAG_IMMED2_CATCH)
#define is_not_catch(x)	(!is_catch(x))
#define _unchecked_catch_val(x)	((x) >> _TAG_IMMED2_SIZE)
_ET_DECLARE_CHECKED(Uint,catch_val,Eterm)
#define catch_val(x)	_ET_APPLY(catch_val,(x))

#define make_blank(X)	((X) = NIL)

/*
 * Overloaded tags.
 *
 * SMALL = 15
 * ATOM/NIL=7
 *
 * Note that the two least significant bits in SMALL/ATOM/NIL always are 3;
 * thus, we can distinguish register from literals by looking at only these
 * two bits.
 */

#define X_REG_DEF	0
#define Y_REG_DEF	1
#define R_REG_DEF	2

#define beam_reg_tag(x)	((x) & 3)

#define make_rreg()	R_REG_DEF
#define make_xreg(ix)	(((ix) * sizeof(Eterm)) | X_REG_DEF)
#define make_yreg(ix)	(((ix) * sizeof(Eterm)) | Y_REG_DEF)

#define _is_xreg(x)	(beam_reg_tag(x) == X_REG_DEF)
#define _is_yreg(x)	(beam_reg_tag(x) == Y_REG_DEF)

#define _unchecked_x_reg_offset(R)	((R) - X_REG_DEF)
_ET_DECLARE_CHECKED(Uint,x_reg_offset,Uint)
#define x_reg_offset(R)	_ET_APPLY(x_reg_offset,(R))

#define _unchecked_y_reg_offset(R)	((R) - Y_REG_DEF)
_ET_DECLARE_CHECKED(Uint,y_reg_offset,Uint)
#define y_reg_offset(R)	_ET_APPLY(y_reg_offset,(R))

#define reg_index(R) ((R) / sizeof(Eterm))

#define _unchecked_x_reg_index(R)	((R) >> 2)
_ET_DECLARE_CHECKED(Uint,x_reg_index,Uint)
#define x_reg_index(R)	_ET_APPLY(x_reg_index,(R))

#define _unchecked_y_reg_index(R)	((R) >> 2)
_ET_DECLARE_CHECKED(Uint,y_reg_index,Uint)
#define y_reg_index(R)	_ET_APPLY(y_reg_index,(R))

/*
 * Backwards compatibility definitions:
 * - #define virtal *_DEF constants with values that fit term order:
 *   number < atom < ref < fun < port < pid < tuple < nil < cons < binary
 * - tag_val_def() function generates virtual _DEF tag
 * - not_eq_tags() and NUMBER_CODE() defined in terms
 *   of the tag_val_def() function
 */

#define BINARY_DEF		0x0
#define LIST_DEF		0x1
#define NIL_DEF			0x2
#define TUPLE_DEF		0x3
#define PID_DEF			0x4
#define EXTERNAL_PID_DEF	0x5
#define PORT_DEF		0x6
#define EXTERNAL_PORT_DEF	0x7
#define EXPORT_DEF		0x8
#define FUN_DEF			0x9
#define REF_DEF			0xa
#define EXTERNAL_REF_DEF	0xb
#define ATOM_DEF		0xc
#define FLOAT_DEF		0xd
#define BIG_DEF			0xe
#define SMALL_DEF		0xf

#if ET_DEBUG
extern unsigned tag_val_def_debug(Eterm, const char*, unsigned);
#define tag_val_def(x)	tag_val_def_debug((x),__FILE__,__LINE__)
#else
extern unsigned tag_val_def(Eterm);
#endif
#define not_eq_tags(X,Y)	(tag_val_def((X)) ^ tag_val_def((Y)))

#define NUMBER_CODE(x,y)	((tag_val_def(x) << 4) | tag_val_def(y))
#define _NUMBER_CODE(TX,TY)	((TX << 4) | TY)
#define SMALL_SMALL	_NUMBER_CODE(SMALL_DEF,SMALL_DEF)
#define SMALL_BIG 	_NUMBER_CODE(SMALL_DEF,BIG_DEF)
#define SMALL_FLOAT 	_NUMBER_CODE(SMALL_DEF,FLOAT_DEF)
#define BIG_SMALL 	_NUMBER_CODE(BIG_DEF,SMALL_DEF)
#define BIG_BIG 	_NUMBER_CODE(BIG_DEF,BIG_DEF)
#define BIG_FLOAT 	_NUMBER_CODE(BIG_DEF,FLOAT_DEF)
#define FLOAT_SMALL 	_NUMBER_CODE(FLOAT_DEF,SMALL_DEF)
#define FLOAT_BIG 	_NUMBER_CODE(FLOAT_DEF,BIG_DEF)
#define FLOAT_FLOAT	_NUMBER_CODE(FLOAT_DEF,FLOAT_DEF)

#endif	/* __ERL_TERM_H */