/* Definitions of floating-point access for GNU compiler.
   Copyright (C) 1989, 1991, 1994, 1996, 1997, 1998,
   1999, 2000, 2002 Free Software Foundation, Inc.

   This file is part of GCC.

   GCC 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, or (at your option) any later
   version.

   GCC 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 GCC; see the file COPYING.  If not, write to the Free
   Software Foundation, 59 Temple Place - Suite 330, Boston, MA
   02111-1307, USA.  */

#ifndef GCC_REAL_H
#define GCC_REAL_H

#include "machmode.h"

/* REAL_VALUE_TYPE is an array of the minimum number of HOST_WIDE_INTs
   required to hold a 128-bit floating point type.  This is true even
   if the maximum precision floating point type on the target is smaller.

   The extra 32 bits are for storing the mode of the float.  Ideally
   we'd keep this elsewhere, but that's too drastic a change all at once.  */

#define REAL_VALUE_TYPE_SIZE (128 + 32)
#define REAL_WIDTH \
  (REAL_VALUE_TYPE_SIZE/HOST_BITS_PER_WIDE_INT \
   + (REAL_VALUE_TYPE_SIZE%HOST_BITS_PER_WIDE_INT ? 1 : 0)) /* round up */

struct realvaluetype GTY(()) {
  HOST_WIDE_INT r[REAL_WIDTH];
};

/* Various headers condition prototypes on #ifdef REAL_VALUE_TYPE, so it needs
   to be a macro.  realvaluetype cannot be a typedef as this interferes with
   other headers declaring opaque pointers to it.  */
#define REAL_VALUE_TYPE struct realvaluetype

/* Calculate the format for CONST_DOUBLE.  We need as many slots as
   are necessary to overlay a REAL_VALUE_TYPE on them.  This could be
   as many as four (32-bit HOST_WIDE_INT, 128-bit REAL_VALUE_TYPE).

   A number of places assume that there are always at least two 'w'
   slots in a CONST_DOUBLE, so we provide them even if one would suffice.  */

#if REAL_WIDTH == 1
# define CONST_DOUBLE_FORMAT	 "ww"
#else
# if REAL_WIDTH == 2
#  define CONST_DOUBLE_FORMAT	 "ww"
# else
#  if REAL_WIDTH == 3
#   define CONST_DOUBLE_FORMAT	 "www"
#  else
#   if REAL_WIDTH == 4
#    define CONST_DOUBLE_FORMAT	 "wwww"
#   else
#    if REAL_WIDTH == 5
#     define CONST_DOUBLE_FORMAT "wwwww"
#    else
      #error "REAL_WIDTH > 5 not supported"
#    endif
#   endif
#  endif
# endif
#endif

/* Declare functions in real.c.  */

/* Initialize the emulator.  */
extern void init_real_once	PARAMS ((void));

/* Binary or unary arithmetic on tree_code.  */
extern void real_arithmetic	PARAMS ((REAL_VALUE_TYPE *, int,
					 const REAL_VALUE_TYPE *,
					 const REAL_VALUE_TYPE *));

/* Compare reals by tree_code.  */
extern bool real_compare	PARAMS ((int, const REAL_VALUE_TYPE *,
					 const REAL_VALUE_TYPE *));

/* Determine whether a floating-point value X is infinite.  */
extern bool real_isinf		PARAMS ((const REAL_VALUE_TYPE *));

/* Determine whether a floating-point value X is a NaN.  */
extern bool real_isnan		PARAMS ((const REAL_VALUE_TYPE *));

/* Determine whether a floating-point value X is negative.  */
extern bool real_isneg		PARAMS ((const REAL_VALUE_TYPE *));

/* Determine whether a floating-point value X is minus zero.  */
extern bool real_isnegzero	PARAMS ((const REAL_VALUE_TYPE *));

/* Compare two floating-point objects for bitwise identity.  */
extern bool real_identical	PARAMS ((const REAL_VALUE_TYPE *,
					 const REAL_VALUE_TYPE *));

/* Extend or truncate to a new mode.  */
extern void real_convert	PARAMS ((REAL_VALUE_TYPE *,
					 enum machine_mode,
					 const REAL_VALUE_TYPE *));

/* Return true if truncating to NEW is exact.  */
extern bool exact_real_truncate PARAMS ((enum machine_mode,
					 const REAL_VALUE_TYPE *));

/* Render R as a decimal floating point constant.  */
extern void real_to_decimal	PARAMS ((char *, const REAL_VALUE_TYPE *,
					 int));

/* Render R as a hexadecimal floating point constant.  */
extern void real_to_hexadecimal	PARAMS ((char *, const REAL_VALUE_TYPE *,
					 int));

/* Render R as an integer.  */
extern HOST_WIDE_INT real_to_integer PARAMS ((const REAL_VALUE_TYPE *));
extern void real_to_integer2 PARAMS ((HOST_WIDE_INT *, HOST_WIDE_INT *,
				      const REAL_VALUE_TYPE *));

/* Initialize R from a decimal or hexadecimal string.  */
extern void real_from_string	PARAMS ((REAL_VALUE_TYPE *, const char *));

/* Initialize R from an integer pair HIGH/LOW.  */
extern void real_from_integer	PARAMS ((REAL_VALUE_TYPE *,
					 enum machine_mode,
					 unsigned HOST_WIDE_INT,
					 HOST_WIDE_INT, int));

extern long real_to_target	PARAMS ((long *, const REAL_VALUE_TYPE *,
					 enum machine_mode));

extern void real_from_target	PARAMS ((REAL_VALUE_TYPE *, const long *,
					 enum machine_mode));

extern void real_inf		PARAMS ((REAL_VALUE_TYPE *));

extern bool real_nan		PARAMS ((REAL_VALUE_TYPE *, const char *,
					 int, enum machine_mode));

extern void real_2expN		PARAMS ((REAL_VALUE_TYPE *, int));

/* ====================================================================== */
/* Crap.  */

/* Define codes for all the float formats that we know of.  */
#define UNKNOWN_FLOAT_FORMAT 0
#define IEEE_FLOAT_FORMAT 1
#define VAX_FLOAT_FORMAT 2
#define IBM_FLOAT_FORMAT 3
#define C4X_FLOAT_FORMAT 4

/* Default to IEEE float if not specified.  Nearly all machines use it.  */

#ifndef TARGET_FLOAT_FORMAT
#define	TARGET_FLOAT_FORMAT	IEEE_FLOAT_FORMAT
#endif

#define REAL_ARITHMETIC(value, code, d1, d2) \
  real_arithmetic (&(value), code, &(d1), &(d2))

#define REAL_VALUES_IDENTICAL(x, y)	real_identical (&(x), &(y))
#define REAL_VALUES_EQUAL(x, y)		real_compare (EQ_EXPR, &(x), &(y))
#define REAL_VALUES_LESS(x, y)		real_compare (LT_EXPR, &(x), &(y))

/* Determine whether a floating-point value X is infinite.  */
#define REAL_VALUE_ISINF(x)		real_isinf (&(x))

/* Determine whether a floating-point value X is a NaN.  */
#define REAL_VALUE_ISNAN(x)		real_isnan (&(x))

/* Determine whether a floating-point value X is negative.  */
#define REAL_VALUE_NEGATIVE(x)		real_isneg (&(x))

/* Determine whether a floating-point value X is minus zero.  */
#define REAL_VALUE_MINUS_ZERO(x)	real_isnegzero (&(x))

/* IN is a REAL_VALUE_TYPE.  OUT is an array of longs.  */
#define REAL_VALUE_TO_TARGET_LONG_DOUBLE(IN, OUT)			\
  real_to_target (OUT, &(IN),						\
		  mode_for_size (LONG_DOUBLE_TYPE_SIZE, MODE_FLOAT, 0))

#define REAL_VALUE_TO_TARGET_DOUBLE(IN, OUT) \
  real_to_target (OUT, &(IN), mode_for_size (64, MODE_FLOAT, 0))

/* IN is a REAL_VALUE_TYPE.  OUT is a long.  */
#define REAL_VALUE_TO_TARGET_SINGLE(IN, OUT) \
  ((OUT) = real_to_target (NULL, &(IN), mode_for_size (32, MODE_FLOAT, 0)))

#define REAL_VALUE_TO_DECIMAL(r, s, dig) \
  real_to_decimal (s, &(r), dig)

#define REAL_VALUE_FROM_INT(r, lo, hi, mode) \
  real_from_integer (&(r), mode, lo, hi, 0)

#define REAL_VALUE_FROM_UNSIGNED_INT(r, lo, hi, mode) \
  real_from_integer (&(r), mode, lo, hi, 1)

extern REAL_VALUE_TYPE real_value_truncate PARAMS ((enum machine_mode,
						    REAL_VALUE_TYPE));

#define REAL_VALUE_TO_INT(plow, phigh, r) \
  real_to_integer2 (plow, phigh, &(r))

extern REAL_VALUE_TYPE real_arithmetic2 PARAMS ((int, const REAL_VALUE_TYPE *,
						 const REAL_VALUE_TYPE *));

#define REAL_VALUE_NEGATE(X) \
  real_arithmetic2 (NEGATE_EXPR, &(X), NULL)

#define REAL_VALUE_ABS(X) \
  real_arithmetic2 (ABS_EXPR, &(X), NULL)

extern int significand_size PARAMS ((enum machine_mode));

extern REAL_VALUE_TYPE real_from_string2 PARAMS ((const char *,
						  enum machine_mode));

#define REAL_VALUE_ATOF(s, m) \
  real_from_string2 (s, m)

#define CONST_DOUBLE_ATOF(s, m) \
  CONST_DOUBLE_FROM_REAL_VALUE (real_from_string2 (s, m), m)

#define REAL_VALUE_FIX(r) \
  real_to_integer (&(r))

/* ??? Not quite right.  */
#define REAL_VALUE_UNSIGNED_FIX(r) \
  real_to_integer (&(r))

/* ??? These were added for Paranoia support.  */

/* Return floor log2(R).  */
extern int real_exponent	PARAMS ((const REAL_VALUE_TYPE *));

/* R = A * 2**EXP.  */
extern void real_ldexp		PARAMS ((REAL_VALUE_TYPE *,
					 const REAL_VALUE_TYPE *, int));

/* **** End of software floating point emulator interface macros **** */

/* Constant real values 0, 1, 2, and -1.  */

extern REAL_VALUE_TYPE dconst0;
extern REAL_VALUE_TYPE dconst1;
extern REAL_VALUE_TYPE dconst2;
extern REAL_VALUE_TYPE dconstm1;

/* Function to return a real value (not a tree node)
   from a given integer constant.  */
REAL_VALUE_TYPE real_value_from_int_cst	PARAMS ((union tree_node *,
						 union tree_node *));

/* Given a CONST_DOUBLE in FROM, store into TO the value it represents.  */
#define REAL_VALUE_FROM_CONST_DOUBLE(to, from) \
  memcpy (&(to), &CONST_DOUBLE_LOW ((from)), sizeof (REAL_VALUE_TYPE))

/* Return a CONST_DOUBLE with value R and mode M.  */
#define CONST_DOUBLE_FROM_REAL_VALUE(r, m) \
  const_double_from_real_value (r, m)
extern rtx const_double_from_real_value PARAMS ((REAL_VALUE_TYPE,
						 enum machine_mode));

/* Replace R by 1/R in the given machine mode, if the result is exact.  */
extern bool exact_real_inverse	PARAMS ((enum machine_mode, REAL_VALUE_TYPE *));

/* In tree.c: wrap up a REAL_VALUE_TYPE in a tree node.  */
extern tree build_real			PARAMS ((tree, REAL_VALUE_TYPE));


#endif /* ! GCC_REAL_H */