/* -*-C-*-

$Id: object.h,v 9.59 2005/07/24 05:10:03 cph Exp $

Copyright 1986,1987,1988,1989,1990,1992 Massachusetts Institute of Technology
Copyright 1993,1995,1997,1998,2000,2001 Massachusetts Institute of Technology
Copyright 2003,2005 Massachusetts Institute of Technology

This file is part of MIT/GNU Scheme.

MIT/GNU Scheme is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or (at
your option) any later version.

MIT/GNU Scheme is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with MIT/GNU Scheme; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
USA.

*/

/* This file defines the macros which define and manipulate Scheme
   objects.  This is the lowest level of abstraction in this program. 
*/
#ifndef SCM_OBJECT_H
#define SCM_OBJECT_H

/* The value in "Wsize.c" for `TYPE_CODE_LENGTH' must match this!! */
#ifndef TYPE_CODE_LENGTH
#  define TYPE_CODE_LENGTH 8
#endif

#if defined(MIN_TYPE_CODE_LENGTH) && (TYPE_CODE_LENGTH < MIN_TYPE_CODE_LENGTH)
#  include "Inconsistency between object.h and types.h: MIN_TYPE_CODE_LENGTH"
#endif

#if (SIZEOF_UNSIGNED_LONG == 4)	/* 32 bit word versions */
#  if (TYPE_CODE_LENGTH == 8)
#    define MAX_TYPE_CODE	0xFF
#    define DATUM_LENGTH	24
#    define FIXNUM_LENGTH	23
#    define FIXNUM_SIGN_BIT	0x00800000
#    define SIGN_MASK		0xFF800000
#    define SMALLEST_FIXNUM	((long) 0xFF800000)
#    define BIGGEST_FIXNUM	((long) 0x007FFFFF)
#    define HALF_DATUM_LENGTH	12
#    define HALF_DATUM_MASK	0x00000FFF
#    define DATUM_MASK		0x00FFFFFF
#    define TYPE_CODE_MASK	0xFF000000
#  endif
#  if (TYPE_CODE_LENGTH == 6)
#    define MAX_TYPE_CODE	0x3F
#    define DATUM_LENGTH	26
#    define FIXNUM_LENGTH	25
#    define FIXNUM_SIGN_BIT	0x02000000
#    define SIGN_MASK		0xFE000000
#    define SMALLEST_FIXNUM	((long) 0xFE000000)
#    define BIGGEST_FIXNUM	((long) 0x01FFFFFF)
#    define HALF_DATUM_LENGTH	13
#    define HALF_DATUM_MASK	0x00001FFF
#    define DATUM_MASK		0x03FFFFFF
#    define TYPE_CODE_MASK	0XFC000000
#  endif
#endif

#ifndef DATUM_LENGTH		/* Safe versions */
#  define MAX_TYPE_CODE		((1 << TYPE_CODE_LENGTH) - 1)
#  define DATUM_LENGTH		(OBJECT_LENGTH - TYPE_CODE_LENGTH)
   /* FIXNUM_LENGTH does NOT include the sign bit! */
#  define FIXNUM_LENGTH		(DATUM_LENGTH - 1)
#  define FIXNUM_SIGN_BIT	(1L << FIXNUM_LENGTH)
#  define SIGN_MASK		((long) (-1L << FIXNUM_LENGTH))
#  define SMALLEST_FIXNUM	((long) (-1L << FIXNUM_LENGTH))
#  define BIGGEST_FIXNUM	((1L << FIXNUM_LENGTH) - 1)
#  define HALF_DATUM_LENGTH	(DATUM_LENGTH / 2)
#  define HALF_DATUM_MASK	((1L << HALF_DATUM_LENGTH) - 1)
#  define DATUM_MASK		((1L << DATUM_LENGTH) - 1)
#  define TYPE_CODE_MASK	(~ DATUM_MASK)
#endif

/* Basic object structure */

#ifndef OBJECT_TYPE
#ifdef UNSIGNED_SHIFT_BUG
/* This fixes bug in some compilers. */
#define OBJECT_TYPE(object) (((object) >> DATUM_LENGTH) & MAX_TYPE_CODE)
#else
/* Faster for logical shifts */
#define OBJECT_TYPE(object) ((object) >> DATUM_LENGTH)
#endif
#endif

#define OBJECT_DATUM(object) ((object) & DATUM_MASK)
#define OBJECT_ADDRESS(object) (DATUM_TO_ADDRESS ((object) & DATUM_MASK))

#define MAKE_OBJECT(type, datum)					\
  ((((unsigned long) (type)) << DATUM_LENGTH) | (datum))

#define OBJECT_NEW_DATUM(type_object, datum)				\
  (((type_object) & TYPE_CODE_MASK) | (datum))

#define OBJECT_NEW_TYPE(type, datum_object)				\
  (MAKE_OBJECT ((type), (OBJECT_DATUM (datum_object))))

#define MAKE_OBJECT_FROM_OBJECTS(type_object, datum_object)		\
  (((type_object) & TYPE_CODE_MASK) | ((datum_object) & DATUM_MASK))

#define MAKE_POINTER_OBJECT(type, address)				\
  (MAKE_OBJECT ((type), (ADDRESS_TO_DATUM (address))))

#define OBJECT_NEW_ADDRESS(object, address)				\
  (OBJECT_NEW_DATUM ((object), (ADDRESS_TO_DATUM (address))))

/* Machine dependencies */

#ifndef HEAP_MALLOC
#  define HEAP_MALLOC OS_malloc
#endif

#ifdef HEAP_IN_LOW_MEMORY	/* Storing absolute addresses */

typedef long relocation_type;	/* Used to relocate pointers on fasload */

#define ALLOCATE_HEAP_SPACE(space,low,high) do				\
{									\
  unsigned long _space = (space);					\
  SCHEME_OBJECT * _low							\
    = ((SCHEME_OBJECT *)						\
       (HEAP_MALLOC ((sizeof (SCHEME_OBJECT)) * _space)));		\
									\
  (low) = _low;								\
  (high) = (_low + _space);						\
} while (0)

#ifndef DATUM_TO_ADDRESS
#  define DATUM_TO_ADDRESS(datum) ((SCHEME_OBJECT *) (datum))
#endif

#ifndef ADDRESS_TO_DATUM
#  define ADDRESS_TO_DATUM(address) ((SCHEME_OBJECT) (address))
#endif

#else /* not HEAP_IN_LOW_MEMORY (portable version) */

/* Used to relocate pointers on fasload */

typedef SCHEME_OBJECT * relocation_type;

extern SCHEME_OBJECT * memory_base;

#define ALLOCATE_HEAP_SPACE(space,low,high) do				\
{									\
  unsigned long _space = (space);					\
  memory_base = ((SCHEME_OBJECT *)					\
		 (HEAP_MALLOC ((sizeof (SCHEME_OBJECT)) * _space)));	\
  (low) = memory_base;							\
  (high) = (memory_base + _space);					\
} while (0)

#ifndef DATUM_TO_ADDRESS
#  define DATUM_TO_ADDRESS(datum) ((SCHEME_OBJECT *) ((datum) + memory_base))
#endif

#ifndef ADDRESS_TO_DATUM
#  define ADDRESS_TO_DATUM(address) ((SCHEME_OBJECT) ((address) - memory_base))
#endif

#endif /* HEAP_IN_LOW_MEMORY */

#ifndef SCHEME_ADDR_TO_ADDR
  typedef SCHEME_OBJECT * SCHEME_ADDR;
# define SCHEME_ADDR_TO_ADDR(saddr) ((SCHEME_OBJECT *) (saddr))
# define ADDR_TO_SCHEME_ADDR(caddr) ((SCHEME_OBJECT) (caddr))
#endif /* SCHEME_ADDR_TO_ADDR */

/* Lots of type predicates */

#define FIXNUM_P(object) ((OBJECT_TYPE (object)) == TC_FIXNUM)
#define BIGNUM_P(object) ((OBJECT_TYPE (object)) == TC_BIG_FIXNUM)
#define FLONUM_P(object) ((OBJECT_TYPE (object)) == TC_BIG_FLONUM)
#define COMPLEX_P(object) ((OBJECT_TYPE (object)) == TC_COMPLEX)
#define CHARACTER_P(object) ((OBJECT_TYPE (object)) == TC_CHARACTER)
#define STRING_P(object) ((OBJECT_TYPE (object)) == TC_CHARACTER_STRING)
#define BIT_STRING_P(object) ((OBJECT_TYPE (object)) == TC_BIT_STRING)
#define CELL_P(object) ((OBJECT_TYPE (object)) == TC_CELL)
#define PAIR_P(object) ((OBJECT_TYPE (object)) == TC_LIST)
#define WEAK_PAIR_P(object) ((OBJECT_TYPE (object)) == TC_WEAK_CONS)
#define VECTOR_P(object) ((OBJECT_TYPE (object)) == TC_VECTOR)
#define RECORD_P(object) ((OBJECT_TYPE (object)) == TC_RECORD)
#define BOOLEAN_P(object) (((object) == SHARP_T) || ((object) == SHARP_F))
#define REFERENCE_TRAP_P(object) ((OBJECT_TYPE (object)) == TC_REFERENCE_TRAP)
#define PRIMITIVE_P(object) ((OBJECT_TYPE (object)) == TC_PRIMITIVE)
#define FUTURE_P(object) ((OBJECT_TYPE (object)) == TC_FUTURE)
#define PROMISE_P(object) ((OBJECT_TYPE (object)) == TC_DELAYED)
#define APPARENT_LIST_P(object) ((EMPTY_LIST_P (object)) || (PAIR_P (object)))
#define CONTROL_POINT_P(object) ((OBJECT_TYPE (object)) == TC_CONTROL_POINT)
#define BROKEN_HEART_P(object) ((OBJECT_TYPE (object)) == TC_BROKEN_HEART)
#define GC_NON_POINTER_P(object) ((GC_Type (object)) == GC_Non_Pointer)
#define GC_CELL_P(object) ((GC_Type (object)) == GC_Cell)
#define GC_PAIR_P(object) ((GC_Type (object)) == GC_Pair)
#define GC_TRIPLE_P(object) ((GC_Type (object)) == GC_Triple)
#define GC_QUADRUPLE_P(object) ((GC_Type (object)) == GC_Quadruple)
#define GC_VECTOR_P(object) ((GC_Type (object)) == GC_Vector)

#define COMPILED_CODE_ADDRESS_P(object)					\
  ((OBJECT_TYPE (object)) == TC_COMPILED_ENTRY)

#define STACK_ADDRESS_P(object)						\
  ((OBJECT_TYPE (object)) == TC_STACK_ENVIRONMENT)

#define NON_MARKED_VECTOR_P(object)					\
  ((OBJECT_TYPE (object)) == TC_NON_MARKED_VECTOR)

#define SYMBOL_P(object)						\
  (((OBJECT_TYPE (object)) == TC_INTERNED_SYMBOL) ||			\
   ((OBJECT_TYPE (object)) == TC_UNINTERNED_SYMBOL))

#define INTEGER_P(object)						\
  (((OBJECT_TYPE (object)) == TC_FIXNUM) ||				\
   ((OBJECT_TYPE (object)) == TC_BIG_FIXNUM))

#define REAL_P(object)							\
  (((OBJECT_TYPE (object)) == TC_FIXNUM) ||				\
   ((OBJECT_TYPE (object)) == TC_BIG_FIXNUM) ||				\
   ((OBJECT_TYPE (object)) == TC_BIG_FLONUM))

#define NUMBER_P(object)						\
  (((OBJECT_TYPE (object)) == TC_FIXNUM) ||				\
   ((OBJECT_TYPE (object)) == TC_BIG_FIXNUM) ||				\
   ((OBJECT_TYPE (object)) == TC_BIG_FLONUM)				\
   ((OBJECT_TYPE (object)) == TC_COMPLEX))

#define HUNK3_P(object)							\
  (((OBJECT_TYPE (object)) == TC_HUNK3_A) ||				\
   ((OBJECT_TYPE (object)) == TC_HUNK3_B))

#define INTERPRETER_APPLICABLE_P interpreter_applicable_p

#define ENVIRONMENT_P(env)						\
  (((OBJECT_TYPE (env)) == TC_ENVIRONMENT) || (GLOBAL_FRAME_P (env)))

/* Memory Operations */

/* The FAST_ operations are used only where the object is known to be
   immutable.  On a parallel processor they don't require atomic
   references. */

#define FAST_MEMORY_REF(object, offset)					\
  ((OBJECT_ADDRESS (object)) [(offset)])

#define FAST_MEMORY_SET(object, offset, value)				\
  ((OBJECT_ADDRESS (object)) [(offset)]) = (value)

#define MEMORY_LOC(object, offset)					\
  (& ((OBJECT_ADDRESS (object)) [(offset)]))

/* General case memory access requires atomicity for parallel processors. */

#define MEMORY_REF(object, offset)					\
  (MEMORY_FETCH ((OBJECT_ADDRESS (object)) [(offset)]))

#define MEMORY_SET(object, offset, value)				\
  MEMORY_STORE (((OBJECT_ADDRESS (object)) [(offset)]), (value))

/* Pair Operations */

#define FAST_PAIR_CAR(pair) (FAST_MEMORY_REF ((pair), CONS_CAR))
#define FAST_PAIR_CDR(pair) (FAST_MEMORY_REF ((pair), CONS_CDR))
#define FAST_SET_PAIR_CAR(pair, car) FAST_MEMORY_SET ((pair), CONS_CAR, (car))
#define FAST_SET_PAIR_CDR(pair, cdr) FAST_MEMORY_SET ((pair), CONS_CDR, (cdr))
#define PAIR_CAR_LOC(pair) (MEMORY_LOC ((pair), CONS_CAR))
#define PAIR_CDR_LOC(pair) (MEMORY_LOC ((pair), CONS_CDR))

#define PAIR_CAR(pair) (MEMORY_REF ((pair), CONS_CAR))
#define PAIR_CDR(pair) (MEMORY_REF ((pair), CONS_CDR))
#define SET_PAIR_CAR(pair, car) MEMORY_SET ((pair), CONS_CAR, (car))
#define SET_PAIR_CDR(pair, cdr) MEMORY_SET ((pair), CONS_CDR, (cdr))

/* Vector Operations */

#define VECTOR_LENGTH(vector) (OBJECT_DATUM (FAST_MEMORY_REF ((vector), 0)))

#define SET_VECTOR_LENGTH(vector, length)				\
  FAST_MEMORY_SET							\
    ((vector),								\
     0,									\
     (OBJECT_NEW_DATUM ((FAST_MEMORY_REF ((vector), 0)), (length))));

#define FAST_VECTOR_REF(vector, index)					\
  (FAST_MEMORY_REF ((vector), ((index) + 1)))

#define FAST_VECTOR_SET(vector, index, value)				\
  FAST_MEMORY_SET ((vector), ((index) + 1), (value))

#define VECTOR_LOC(vector, index) (MEMORY_LOC ((vector), ((index) + 1)))
#define VECTOR_REF(vector, index) (MEMORY_REF ((vector), ((index) + 1)))

#define VECTOR_SET(vector, index, value)				\
  MEMORY_SET ((vector), ((index) + 1), (value))

/* String Operations */

/* Add 1 byte to length to account for '\0' at end of string.
   Add 1 word to length to account for string header word. */
#define STRING_LENGTH_TO_GC_LENGTH(length)				\
  ((BYTES_TO_WORDS ((length) + 1)) + 1)

#define STRING_LENGTH(string)						\
  ((long) (MEMORY_REF ((string), STRING_LENGTH_INDEX)))

#define SET_STRING_LENGTH(string, length) do				\
{									\
  MEMORY_SET ((string), STRING_LENGTH_INDEX, (length));			\
  STRING_SET ((string), (length), '\0');				\
} while (0)

/* Subtract 1 to account for the fact that we maintain a '\0'
   at the end of the string. */
#define MAXIMUM_STRING_LENGTH(string)					\
  ((long) ((((VECTOR_LENGTH (string)) - 1) * (sizeof (SCHEME_OBJECT))) - 1))

#define SET_MAXIMUM_STRING_LENGTH(string, length)			\
  SET_VECTOR_LENGTH ((string), (STRING_LENGTH_TO_GC_LENGTH (length)))

#define STRING_LOC(string, index)					\
  (((unsigned char *) (MEMORY_LOC (string, STRING_CHARS))) + (index))

#define STRING_REF(string, index)					\
  ((int) (* (STRING_LOC ((string), (index)))))

#define STRING_SET(string, index, c_char)				\
  (* (STRING_LOC ((string), (index)))) = (c_char)

/* Character Operations */

#define ASCII_LENGTH CHAR_BIT	/* CHAR_BIT in config.h - 8 for unix  */
#define CODE_LENGTH 21
#define BITS_LENGTH 4
#define MIT_ASCII_LENGTH 25

#define CHAR_BITS_META 		0x1
#define CHAR_BITS_CONTROL 	0x2
#define CHAR_BITS_CONTROL_META	0x3

#define MAX_ASCII (1L << ASCII_LENGTH)
#define MAX_CODE (1L << CODE_LENGTH)
#define MAX_BITS (1L << BITS_LENGTH)
#define MAX_MIT_ASCII (1L << MIT_ASCII_LENGTH)

#define MASK_ASCII (MAX_ASCII - 1)
#define CHAR_MASK_CODE (MAX_CODE - 1)
#define CHAR_MASK_BITS (MAX_BITS - 1)
#define MASK_MIT_ASCII (MAX_MIT_ASCII - 1)

#define ASCII_TO_CHAR(ascii) (MAKE_OBJECT (TC_CHARACTER, (ascii)))
#define CHAR_TO_ASCII_P(object) ((OBJECT_DATUM (object)) < MAX_ASCII)
#define CHAR_TO_ASCII(object) ((object) & MASK_ASCII)

#define MAKE_CHAR(bucky_bits, code)					\
  (MAKE_OBJECT								\
   (TC_CHARACTER,							\
    (((unsigned long) (bucky_bits)) << (CODE_LENGTH)) | (code)))

#define CHAR_BITS(chr)						\
  ((((unsigned long) (OBJECT_DATUM (chr))) >> CODE_LENGTH) & CHAR_MASK_BITS)

#define CHAR_CODE(chr) ((OBJECT_DATUM (chr)) & CHAR_MASK_CODE)

/* Fixnum Operations */

#define FIXNUM_ZERO_P(fixnum) ((OBJECT_DATUM (fixnum)) == 0)
#define FIXNUM_NEGATIVE_P(fixnum) (((fixnum) & FIXNUM_SIGN_BIT) != 0)
#define UNSIGNED_FIXNUM_P(x) ((FIXNUM_P (x)) && (! (FIXNUM_NEGATIVE_P (x))))
#define FIXNUM_EQUAL_P(x, y) ((OBJECT_DATUM (x)) == (OBJECT_DATUM (y)))
#define FIXNUM_LESS_P(x, y) ((FIXNUM_TO_LONG (x)) < (FIXNUM_TO_LONG (y)))

#define FIXNUM_POSITIVE_P(fixnum)					\
  (! ((FIXNUM_ZERO_P (fixnum)) || (FIXNUM_NEGATIVE_P (fixnum))))

#define UNSIGNED_FIXNUM_TO_LONG(fixnum) ((long) (OBJECT_DATUM (fixnum)))
#define LONG_TO_UNSIGNED_FIXNUM_P(value) (((value) & SIGN_MASK) == 0)
#define LONG_TO_UNSIGNED_FIXNUM(value) (FIXNUM_ZERO + (value))
#define LONG_TO_FIXNUM(value) (OBJECT_NEW_TYPE (TC_FIXNUM, (value)))

#define LONG_TO_FIXNUM_P(value)						\
  ((((value) & SIGN_MASK) == 0) || (((value) & SIGN_MASK) == SIGN_MASK))

#define FIXNUM_TO_LONG(fixnum)						\
  ((((long) (fixnum)) ^ ((long) FIXNUM_SIGN_BIT))			\
   - ((long) ((((unsigned long) TC_FIXNUM) << DATUM_LENGTH)		\
	      | FIXNUM_SIGN_BIT)))

#define ULONG_TO_FIXNUM_P(value) (((value) & SIGN_MASK) == 0)
#define ULONG_TO_FIXNUM(value) (FIXNUM_ZERO + (value))
#define FIXNUM_TO_ULONG_P(fixnum) (((OBJECT_DATUM (fixnum)) & SIGN_MASK) == 0)
#define FIXNUM_TO_ULONG(fixnum) (OBJECT_DATUM (fixnum))

#define FIXNUM_TO_DOUBLE(fixnum) ((double) (FIXNUM_TO_LONG (fixnum)))

#define DOUBLE_TO_FIXNUM_P(number)					\
  (((number) > ((double) (SMALLEST_FIXNUM - 1)))			\
   && ((number) < ((double) (BIGGEST_FIXNUM + 1))))

#ifdef HAVE_DOUBLE_TO_LONG_BUG
#define DOUBLE_TO_FIXNUM double_to_fixnum
#else
#define DOUBLE_TO_FIXNUM(number) (LONG_TO_FIXNUM ((long) (number)))
#endif

/* Bignum Operations */

#define BIGNUM_ZERO_P(bignum)						\
  ((bignum_test (bignum)) == bignum_comparison_equal)

#define BIGNUM_NEGATIVE_P(bignum)					\
  ((bignum_test (bignum)) == bignum_comparison_less)

#define BIGNUM_POSITIVE_P(bignum)					\
  ((bignum_test (bignum)) == bignum_comparison_greater)

#define BIGNUM_LESS_P(x, y)						\
  ((bignum_compare ((x), (y))) == bignum_comparison_less)

#define BIGNUM_TO_LONG_P(bignum)					\
  (bignum_fits_in_word_p ((bignum), ((sizeof (long)) * CHAR_BIT), 1))

#define BIGNUM_TO_ULONG_P(bignum)					\
  (bignum_fits_in_word_p ((bignum), ((sizeof (unsigned long)) * CHAR_BIT), 0))

/* If precision should not be lost,
   compare to DBL_MANT_DIG instead. */
#define BIGNUM_TO_DOUBLE_P(bignum)					\
  (bignum_fits_in_word_p ((bignum), DBL_MAX_EXP, 0))

/* Flonum Operations */

#define FLONUM_SIZE (BYTES_TO_WORDS (sizeof (double)))

#define FLONUM_TO_DOUBLE(object)					\
  (* ((double *) (MEMORY_LOC ((object), 1))))

#define FLOAT_TO_FLONUM(expression)					\
  (double_to_flonum ((double) (expression)))

#define FLONUM_TRUNCATE(object)						\
  (double_to_flonum (double_truncate (FLONUM_TO_DOUBLE (object))))

/* Flonum-vector Operations */

#define FLOATING_VECTOR_LENGTH(vector)					\
  ((VECTOR_LENGTH (vector)) / FLONUM_SIZE)

#define FLOATING_VECTOR_LOC(vector, index)				\
  ((double *) (VECTOR_LOC ((vector), ((index) * FLONUM_SIZE))))

#define FLOATING_VECTOR_REF(vector, index)				\
  (* (FLOATING_VECTOR_LOC ((vector), (index))))

#define FLOATING_VECTOR_SET(vector, index, x)				\
  (* (FLOATING_VECTOR_LOC ((vector), (index)))) = ((double) (x))

/* Numeric Type Conversions */

#define BIGNUM_TO_FIXNUM_P(bignum)					\
  (bignum_fits_in_word_p ((bignum), (FIXNUM_LENGTH + 1), 1))

#define FIXNUM_TO_BIGNUM(fixnum) (long_to_bignum (FIXNUM_TO_LONG (fixnum)))
#define FIXNUM_TO_FLONUM(fixnum) (double_to_flonum (FIXNUM_TO_DOUBLE (fixnum)))
#define BIGNUM_TO_FIXNUM(bignum) (LONG_TO_FIXNUM (bignum_to_long (bignum)))
#define BIGNUM_TO_FLONUM_P BIGNUM_TO_DOUBLE_P
#define BIGNUM_TO_FLONUM(bignum) (double_to_flonum (bignum_to_double (bignum)))
#define FLONUM_TO_BIGNUM(flonum) (double_to_bignum (FLONUM_TO_DOUBLE (flonum)))
#define FLONUM_TO_INTEGER(x) (double_to_integer (FLONUM_TO_DOUBLE (x)))
#define INTEGER_TO_FLONUM_P integer_to_double_p
#define INTEGER_TO_FLONUM(n) (double_to_flonum (integer_to_double (n)))

#define BOOLEAN_TO_OBJECT(expression) ((expression) ? SHARP_T : SHARP_F)
#define OBJECT_TO_BOOLEAN(object) ((object) != SHARP_F)

#define MAKE_BROKEN_HEART(address)					\
  (BROKEN_HEART_ZERO + (ADDRESS_TO_DATUM (address)))

#define BYTES_TO_WORDS(nbytes)						\
  (((nbytes) + ((sizeof (SCHEME_OBJECT)) - 1)) / (sizeof (SCHEME_OBJECT)))

#define ADDRESS_CONSTANT_P(address)					\
  (((address) >= Constant_Space) && ((address) < Free_Constant))

#define ADDRESS_PURE_P(address)						\
  ((ADDRESS_CONSTANT_P (address)) && (Pure_Test (address)))

#define ADDRESS_HEAP_P(address)						\
  (((address) >= Heap_Bottom) && ((address) < Heap_Top))

#define SIDE_EFFECT_IMPURIFY(Old_Pointer, Will_Contain)			\
if ((ADDRESS_CONSTANT_P (OBJECT_ADDRESS (Old_Pointer))) &&		\
    (GC_Type (Will_Contain) != GC_Non_Pointer) &&			\
    (! (ADDRESS_CONSTANT_P (OBJECT_ADDRESS (Will_Contain)))) &&		\
    (Pure_Test (OBJECT_ADDRESS (Old_Pointer))))				\
  signal_error_from_primitive (ERR_WRITE_INTO_PURE_SPACE);		\

#ifndef FLOATING_ALIGNMENT
#  define FLOATING_ALIGNMENT 0
#endif

#define FLOATING_ALIGNED_P(ptr)						\
  ((((unsigned long) ((ptr) + 1)) & FLOATING_ALIGNMENT) == 0)

#define ALIGN_FLOAT(Where) do						\
{									\
  while (!FLOATING_ALIGNED_P (Where))					\
    (*(Where)++) = (MAKE_OBJECT (TC_MANIFEST_NM_VECTOR, 0));		\
} while (0)

#endif /* SCM_OBJECT_H */
