icuSources/i18n/decContext.h

   1 /* ------------------------------------------------------------------ */
   2 /* Decimal Context module header                                      */
   3 /* ------------------------------------------------------------------ */
   4 /* Copyright (c) IBM Corporation, 2000-2010.   All rights reserved.   */
   5 /*                                                                    */
   6 /* This software is made available under the terms of the             */
   7 /* ICU License -- ICU 1.8.1 and later.                                */
   8 /*                                                                    */
   9 /* The description and User's Guide ("The decNumber C Library") for   */
  10 /* this software is called decNumber.pdf.  This document is           */
  11 /* available, together with arithmetic and format specifications,     */
  12 /* testcases, and Web links, on the General Decimal Arithmetic page.  */
  13 /*                                                                    */
  14 /* Please send comments, suggestions, and corrections to the author:  */
  15 /*   mfc@uk.ibm.com                                                   */
  16 /*   Mike Cowlishaw, IBM Fellow                                       */
  17 /*   IBM UK, PO Box 31, Birmingham Road, Warwick CV34 5JL, UK         */
  18 /* ------------------------------------------------------------------ */
  19
  20 /* Modified version, for use from within ICU.
  21  *    Renamed public functions, to avoid an unwanted export of the
  22  *    standard names from the ICU library.
  23  *
  24  *    Use ICU's uprv_malloc() and uprv_free()
  25  *
  26  *    Revert comment syntax to plain C
  27  *
  28  *    Remove a few compiler warnings.
  29  */
  30 #include "unicode/utypes.h"
  31
  32 /*                                                                    */
  33 /* Context variables must always have valid values:                   */
  34 /*                                                                    */
  35 /*  status   -- [any bits may be cleared, but not set, by user]       */
  36 /*  round    -- must be one of the enumerated rounding modes          */
  37 /*                                                                    */
  38 /* The following variables are implied for fixed size formats (i.e.,  */
  39 /* they are ignored) but should still be set correctly in case used   */
  40 /* with decNumber functions:                                          */
  41 /*                                                                    */
  42 /*  clamp    -- must be either 0 or 1                                 */
  43 /*  digits   -- must be in the range 1 through 999999999              */
  44 /*  emax     -- must be in the range 0 through 999999999              */
  45 /*  emin     -- must be in the range 0 through -999999999             */
  46 /*  extended -- must be either 0 or 1 [present only if DECSUBSET]     */
  47 /*  traps    -- only defined bits may be set                          */
  48 /*                                                                    */
  49 /* ------------------------------------------------------------------ */
  50
  51 #if !defined(DECCONTEXT)
  52   #define DECCONTEXT
  53   #define DECCNAME     "decContext"                     /* Short name */
  54   #define DECCFULLNAME "Decimal Context Descriptor"   /* Verbose name */
  55   #define DECCAUTHOR   "Mike Cowlishaw"               /* Who to blame */
  56
  57   #if !defined(int32_t)
  58 /* #include <stdint.h>   */         /* C99 standard integers           */
  59   #endif
  60   #include <stdio.h>               /* for printf, etc.                */
  61   #include <signal.h>              /* for traps                       */
  62
  63   /* Extended flags setting -- set this to 0 to use only IEEE flags   */
  64   #if !defined(DECEXTFLAG)
  65   #define DECEXTFLAG 1             /* 1=enable extended flags         */
  66   #endif
  67
  68   /* Conditional code flag -- set this to 0 for best performance      */
  69   #if !defined(DECSUBSET)
  70   #define DECSUBSET  0             /* 1=enable subset arithmetic      */
  71   #endif
  72
  73   /* Context for operations, with associated constants                */
  74   enum rounding {
  75     DEC_ROUND_CEILING,             /* round towards +infinity         */
  76     DEC_ROUND_UP,                  /* round away from 0               */
  77     DEC_ROUND_HALF_UP,             /* 0.5 rounds up                   */
  78     DEC_ROUND_HALF_EVEN,           /* 0.5 rounds to nearest even      */
  79     DEC_ROUND_HALF_DOWN,           /* 0.5 rounds down                 */
  80     DEC_ROUND_DOWN,                /* round towards 0 (truncate)      */
  81     DEC_ROUND_FLOOR,               /* round towards -infinity         */
  82     DEC_ROUND_05UP,                /* round for reround               */
  83     DEC_ROUND_MAX                  /* enum must be less than this     */
  84     };
  85   #define DEC_ROUND_DEFAULT DEC_ROUND_HALF_EVEN;
  86
  87   typedef struct {
  88     int32_t  digits;               /* working precision               */
  89     int32_t  emax;                 /* maximum positive exponent       */
  90     int32_t  emin;                 /* minimum negative exponent       */
  91     enum     rounding round;       /* rounding mode                   */
  92     uint32_t traps;                /* trap-enabler flags              */
  93     uint32_t status;               /* status flags                    */
  94     uint8_t  clamp;                /* flag: apply IEEE exponent clamp */
  95     #if DECSUBSET
  96     uint8_t  extended;             /* flag: special-values allowed    */
  97     #endif
  98     } decContext;
  99
 100   /* Maxima and Minima for context settings                           */
 101   #define DEC_MAX_DIGITS 999999999
 102   #define DEC_MIN_DIGITS         1
 103   #define DEC_MAX_EMAX   999999999
 104   #define DEC_MIN_EMAX           0
 105   #define DEC_MAX_EMIN           0
 106   #define DEC_MIN_EMIN  -999999999
 107   #define DEC_MAX_MATH      999999 /* max emax, etc., for math funcs. */
 108
 109   /* Classifications for decimal numbers, aligned with 754 (note that */
 110   /* 'normal' and 'subnormal' are meaningful only with a decContext   */
 111   /* or a fixed size format).                                         */
 112   enum decClass {
 113     DEC_CLASS_SNAN,
 114     DEC_CLASS_QNAN,
 115     DEC_CLASS_NEG_INF,
 116     DEC_CLASS_NEG_NORMAL,
 117     DEC_CLASS_NEG_SUBNORMAL,
 118     DEC_CLASS_NEG_ZERO,
 119     DEC_CLASS_POS_ZERO,
 120     DEC_CLASS_POS_SUBNORMAL,
 121     DEC_CLASS_POS_NORMAL,
 122     DEC_CLASS_POS_INF
 123     };
 124   /* Strings for the decClasses */
 125   #define DEC_ClassString_SN  "sNaN"
 126   #define DEC_ClassString_QN  "NaN"
 127   #define DEC_ClassString_NI  "-Infinity"
 128   #define DEC_ClassString_NN  "-Normal"
 129   #define DEC_ClassString_NS  "-Subnormal"
 130   #define DEC_ClassString_NZ  "-Zero"
 131   #define DEC_ClassString_PZ  "+Zero"
 132   #define DEC_ClassString_PS  "+Subnormal"
 133   #define DEC_ClassString_PN  "+Normal"
 134   #define DEC_ClassString_PI  "+Infinity"
 135   #define DEC_ClassString_UN  "Invalid"
 136
 137   /* Trap-enabler and Status flags (exceptional conditions), and      */
 138   /* their names.  The top byte is reserved for internal use          */
 139   #if DECEXTFLAG
 140     /* Extended flags */
 141     #define DEC_Conversion_syntax    0x00000001
 142     #define DEC_Division_by_zero     0x00000002
 143     #define DEC_Division_impossible  0x00000004
 144     #define DEC_Division_undefined   0x00000008
 145     #define DEC_Insufficient_storage 0x00000010 /* [when malloc fails]  */
 146     #define DEC_Inexact              0x00000020
 147     #define DEC_Invalid_context      0x00000040
 148     #define DEC_Invalid_operation    0x00000080
 149     #if DECSUBSET
 150     #define DEC_Lost_digits          0x00000100
 151     #endif
 152     #define DEC_Overflow             0x00000200
 153     #define DEC_Clamped              0x00000400
 154     #define DEC_Rounded              0x00000800
 155     #define DEC_Subnormal            0x00001000
 156     #define DEC_Underflow            0x00002000
 157   #else
 158     /* IEEE flags only */
 159     #define DEC_Conversion_syntax    0x00000010
 160     #define DEC_Division_by_zero     0x00000002
 161     #define DEC_Division_impossible  0x00000010
 162     #define DEC_Division_undefined   0x00000010
 163     #define DEC_Insufficient_storage 0x00000010 /* [when malloc fails]  */
 164     #define DEC_Inexact              0x00000001
 165     #define DEC_Invalid_context      0x00000010
 166     #define DEC_Invalid_operation    0x00000010
 167     #if DECSUBSET
 168     #define DEC_Lost_digits          0x00000000
 169     #endif
 170     #define DEC_Overflow             0x00000008
 171     #define DEC_Clamped              0x00000000
 172     #define DEC_Rounded              0x00000000
 173     #define DEC_Subnormal            0x00000000
 174     #define DEC_Underflow            0x00000004
 175   #endif
 176
 177   /* IEEE 754 groupings for the flags                                 */
 178   /* [DEC_Clamped, DEC_Lost_digits, DEC_Rounded, and DEC_Subnormal    */
 179   /* are not in IEEE 754]                                             */
 180   #define DEC_IEEE_754_Division_by_zero  (DEC_Division_by_zero)
 181   #if DECSUBSET
 182   #define DEC_IEEE_754_Inexact           (DEC_Inexact | DEC_Lost_digits)
 183   #else
 184   #define DEC_IEEE_754_Inexact           (DEC_Inexact)
 185   #endif
 186   #define DEC_IEEE_754_Invalid_operation (DEC_Conversion_syntax |     \
 187                                           DEC_Division_impossible |   \
 188                                           DEC_Division_undefined |    \
 189                                           DEC_Insufficient_storage |  \
 190                                           DEC_Invalid_context |       \
 191                                           DEC_Invalid_operation)
 192   #define DEC_IEEE_754_Overflow          (DEC_Overflow)
 193   #define DEC_IEEE_754_Underflow         (DEC_Underflow)
 194
 195   /* flags which are normally errors (result is qNaN, infinite, or 0) */
 196   #define DEC_Errors (DEC_IEEE_754_Division_by_zero |                 \
 197                       DEC_IEEE_754_Invalid_operation |                \
 198                       DEC_IEEE_754_Overflow | DEC_IEEE_754_Underflow)
 199   /* flags which cause a result to become qNaN                        */
 200   #define DEC_NaNs    DEC_IEEE_754_Invalid_operation
 201
 202   /* flags which are normally for information only (finite results)   */
 203   #if DECSUBSET
 204   #define DEC_Information (DEC_Clamped | DEC_Rounded | DEC_Inexact    \
 205                           | DEC_Lost_digits)
 206   #else
 207   #define DEC_Information (DEC_Clamped | DEC_Rounded | DEC_Inexact)
 208   #endif
 209
 210   /* IEEE 854 names (for compatibility with older decNumber versions) */
 211   #define DEC_IEEE_854_Division_by_zero  DEC_IEEE_754_Division_by_zero
 212   #define DEC_IEEE_854_Inexact           DEC_IEEE_754_Inexact
 213   #define DEC_IEEE_854_Invalid_operation DEC_IEEE_754_Invalid_operation
 214   #define DEC_IEEE_854_Overflow          DEC_IEEE_754_Overflow
 215   #define DEC_IEEE_854_Underflow         DEC_IEEE_754_Underflow
 216
 217   /* Name strings for the exceptional conditions                      */
 218   #define DEC_Condition_CS "Conversion syntax"
 219   #define DEC_Condition_DZ "Division by zero"
 220   #define DEC_Condition_DI "Division impossible"
 221   #define DEC_Condition_DU "Division undefined"
 222   #define DEC_Condition_IE "Inexact"
 223   #define DEC_Condition_IS "Insufficient storage"
 224   #define DEC_Condition_IC "Invalid context"
 225   #define DEC_Condition_IO "Invalid operation"
 226   #if DECSUBSET
 227   #define DEC_Condition_LD "Lost digits"
 228   #endif
 229   #define DEC_Condition_OV "Overflow"
 230   #define DEC_Condition_PA "Clamped"
 231   #define DEC_Condition_RO "Rounded"
 232   #define DEC_Condition_SU "Subnormal"
 233   #define DEC_Condition_UN "Underflow"
 234   #define DEC_Condition_ZE "No status"
 235   #define DEC_Condition_MU "Multiple status"
 236   #define DEC_Condition_Length 21  /* length of the longest string,   */
 237                                    /* including terminator            */
 238
 239   /* Initialization descriptors, used by decContextDefault            */
 240   #define DEC_INIT_BASE         0
 241   #define DEC_INIT_DECIMAL32   32
 242   #define DEC_INIT_DECIMAL64   64
 243   #define DEC_INIT_DECIMAL128 128
 244   /* Synonyms */
 245   #define DEC_INIT_DECSINGLE  DEC_INIT_DECIMAL32
 246   #define DEC_INIT_DECDOUBLE  DEC_INIT_DECIMAL64
 247   #define DEC_INIT_DECQUAD    DEC_INIT_DECIMAL128
 248
 249   /* decContext routines                                              */
 250   U_INTERNAL decContext  * U_EXPORT2 uprv_decContextClearStatus(decContext *, uint32_t);
 251   U_INTERNAL decContext  * U_EXPORT2 uprv_decContextDefault(decContext *, int32_t);
 252   U_INTERNAL enum rounding U_EXPORT2 uprv_decContextGetRounding(decContext *);
 253   U_INTERNAL uint32_t      U_EXPORT2 uprv_decContextGetStatus(decContext *);
 254   U_INTERNAL decContext  * U_EXPORT2 uprv_decContextRestoreStatus(decContext *, uint32_t, uint32_t);
 255   U_INTERNAL uint32_t      U_EXPORT2 uprv_decContextSaveStatus(decContext *, uint32_t);
 256   U_INTERNAL decContext  * U_EXPORT2 uprv_decContextSetRounding(decContext *, enum rounding);
 257   U_INTERNAL decContext  * U_EXPORT2 uprv_decContextSetStatus(decContext *, uint32_t);
 258   U_INTERNAL decContext  * U_EXPORT2 uprv_decContextSetStatusFromString(decContext *, const char *);
 259   U_INTERNAL decContext  * U_EXPORT2 uprv_decContextSetStatusFromStringQuiet(decContext *, const char *);
 260   U_INTERNAL decContext  * U_EXPORT2 uprv_decContextSetStatusQuiet(decContext *, uint32_t);
 261   U_INTERNAL const char  * U_EXPORT2 uprv_decContextStatusToString(const decContext *);
 262   U_INTERNAL int32_t       U_EXPORT2 uprv_decContextTestEndian(uint8_t);
 263   U_INTERNAL uint32_t      U_EXPORT2 uprv_decContextTestSavedStatus(uint32_t, uint32_t);
 264   U_INTERNAL uint32_t      U_EXPORT2 uprv_decContextTestStatus(decContext *, uint32_t);
 265   U_INTERNAL decContext  * U_EXPORT2 uprv_decContextZeroStatus(decContext *);
 266
 267 #endif