gcc/libdecnumber/decContext.h

/* Decimal Context module header for the decNumber C Library
   Copyright (C) 2005, 2006 Free Software Foundation, Inc.
   Contributed by IBM Corporation.  Author Mike Cowlishaw.

   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, 51 Franklin Street, Fifth Floor, Boston, MA
   02110-1301, USA.  */

/* ------------------------------------------------------------------ */
/*                                                                    */
/* Context must always be set correctly:                              */
/*                                                                    */
/*  digits   -- must be in the range 1 through 999999999              */
/*  emax     -- must be in the range 0 through 999999999              */
/*  emin     -- must be in the range 0 through -999999999             */
/*  round    -- must be one of the enumerated rounding modes          */
/*  traps    -- only defined bits may be set                          */
/*  status   -- [any bits may be cleared, but not set, by user]       */
/*  clamp    -- must be either 0 or 1                                 */
/*  extended -- must be either 0 or 1 [present only if DECSUBSET]     */
/*                                                                    */
/* ------------------------------------------------------------------ */

#if !defined(DECCONTEXT)
#define DECCONTEXT
#define DECCNAME     "decContext"	/* Short name */
#define DECCFULLNAME "Decimal Context Descriptor"	/* Verbose name */
#define DECCAUTHOR   "Mike Cowlishaw"	/* Who to blame */

#include "gstdint.h"		/* C99 standard integers */
#include <signal.h>		/* for traps */


  /* Conditional code flag -- set this to 0 for best performance */
#define DECSUBSET 0		/* 1 to enable subset arithmetic */

  /* Context for operations, with associated constants */
enum rounding
{
  DEC_ROUND_CEILING,		/* round towards +infinity */
  DEC_ROUND_UP,			/* round away from 0 */
  DEC_ROUND_HALF_UP,		/* 0.5 rounds up */
  DEC_ROUND_HALF_EVEN,		/* 0.5 rounds to nearest even */
  DEC_ROUND_HALF_DOWN,		/* 0.5 rounds down */
  DEC_ROUND_DOWN,		/* round towards 0 (truncate) */
  DEC_ROUND_FLOOR,		/* round towards -infinity */
  DEC_ROUND_MAX			/* enum must be less than this */
};

typedef struct
{
  int32_t digits;		/* working precision */
  int32_t emax;			/* maximum positive exponent */
  int32_t emin;			/* minimum negative exponent */
  enum rounding round;		/* rounding mode */
  uint32_t traps;		/* trap-enabler flags */
  uint32_t status;		/* status flags */
  uint8_t clamp;		/* flag: apply IEEE exponent clamp */
#if DECSUBSET
  uint8_t extended;		/* flag: special-values allowed */
#endif
} decContext;

  /* Maxima and Minima */
#define DEC_MAX_DIGITS 999999999
#define DEC_MIN_DIGITS         1
#define DEC_MAX_EMAX   999999999
#define DEC_MIN_EMAX           0
#define DEC_MAX_EMIN           0
#define DEC_MIN_EMIN  -999999999

  /* Trap-enabler and Status flags (exceptional conditions), and their names */
  /* Top byte is reserved for internal use */
#define DEC_Conversion_syntax    0x00000001
#define DEC_Division_by_zero     0x00000002
#define DEC_Division_impossible  0x00000004
#define DEC_Division_undefined   0x00000008
#define DEC_Insufficient_storage 0x00000010	/* [used if malloc fails] */
#define DEC_Inexact              0x00000020
#define DEC_Invalid_context      0x00000040
#define DEC_Invalid_operation    0x00000080
#if DECSUBSET
#define DEC_Lost_digits          0x00000100
#endif
#define DEC_Overflow             0x00000200
#define DEC_Clamped              0x00000400
#define DEC_Rounded              0x00000800
#define DEC_Subnormal            0x00001000
#define DEC_Underflow            0x00002000

  /* IEEE 854 groupings for the flags */
  /* [DEC_Clamped, DEC_Lost_digits, DEC_Rounded, and DEC_Subnormal are */
  /* not in IEEE 854] */
#define DEC_IEEE_854_Division_by_zero  (DEC_Division_by_zero)
#if DECSUBSET
#define DEC_IEEE_854_Inexact           (DEC_Inexact | DEC_Lost_digits)
#else
#define DEC_IEEE_854_Inexact           (DEC_Inexact)
#endif
#define DEC_IEEE_854_Invalid_operation (DEC_Conversion_syntax |     \
                                          DEC_Division_impossible |   \
                                          DEC_Division_undefined |    \
                                          DEC_Insufficient_storage |  \
                                          DEC_Invalid_context |       \
                                          DEC_Invalid_operation)
#define DEC_IEEE_854_Overflow          (DEC_Overflow)
#define DEC_IEEE_854_Underflow         (DEC_Underflow)

  /* flags which are normally errors (results are qNaN, infinite, or 0) */
#define DEC_Errors (DEC_IEEE_854_Division_by_zero |                 \
                      DEC_IEEE_854_Invalid_operation |                \
                      DEC_IEEE_854_Overflow | DEC_IEEE_854_Underflow)
  /* flags which cause a result to become qNaN */
#define DEC_NaNs    DEC_IEEE_854_Invalid_operation

  /* flags which are normally for information only (have finite results) */
#if DECSUBSET
#define DEC_Information (DEC_Clamped | DEC_Rounded | DEC_Inexact     \
                          | DEC_Lost_digits)
#else
#define DEC_Information (DEC_Clamped | DEC_Rounded | DEC_Inexact)
#endif

  /* name strings for the exceptional conditions */

#define DEC_Condition_CS "Conversion syntax"
#define DEC_Condition_DZ "Division by zero"
#define DEC_Condition_DI "Division impossible"
#define DEC_Condition_DU "Division undefined"
#define DEC_Condition_IE "Inexact"
#define DEC_Condition_IS "Insufficient storage"
#define DEC_Condition_IC "Invalid context"
#define DEC_Condition_IO "Invalid operation"
#if DECSUBSET
#define DEC_Condition_LD "Lost digits"
#endif
#define DEC_Condition_OV "Overflow"
#define DEC_Condition_PA "Clamped"
#define DEC_Condition_RO "Rounded"
#define DEC_Condition_SU "Subnormal"
#define DEC_Condition_UN "Underflow"
#define DEC_Condition_ZE "No status"
#define DEC_Condition_MU "Multiple status"
#define DEC_Condition_Length 21	/* length of the longest string, */
				   /* including terminator */

  /* Initialization descriptors, used by decContextDefault */
#define DEC_INIT_BASE         0
#define DEC_INIT_DECIMAL32   32
#define DEC_INIT_DECIMAL64   64
#define DEC_INIT_DECIMAL128 128

  /* decContext routines */
#ifdef IN_LIBGCC2
#define decContextDefault __decContextDefault
#define decContextSetStatus __decContextSetStatus
#define decContextStatusToString __decContextStatusToString
#define decContextSetStatusFromString __decContextSetStatusFromString
#endif
decContext *decContextDefault (decContext *, int32_t);
decContext *decContextSetStatus (decContext *, uint32_t);
const char *decContextStatusToString (decContext *);
decContext *decContextSetStatusFromString (decContext *, char *);

#endif