source/texk/web2c/mplibdir/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 /* Context variables must always have valid values:                   */
  21 /*                                                                    */
  22 /*  status   -- [any bits may be cleared, but not set, by user]       */
  23 /*  round    -- must be one of the enumerated rounding modes          */
  24 /*                                                                    */
  25 /* The following variables are implied for fixed size formats (i.e.,  */
  26 /* they are ignored) but should still be set correctly in case used   */
  27 /* with decNumber functions:                                          */
  28 /*                                                                    */
  29 /*  clamp    -- must be either 0 or 1                                 */
  30 /*  digits   -- must be in the range 1 through 999999999              */
  31 /*  emax     -- must be in the range 0 through 999999999              */
  32 /*  emin     -- must be in the range 0 through -999999999             */
  33 /*  extended -- must be either 0 or 1 [present only if DECSUBSET]     */
  34 /*  traps    -- only defined bits may be set                          */
  35 /*                                                                    */
  36 /* ------------------------------------------------------------------ */
  37
  38 #if !defined(DECCONTEXT)
  39   #define DECCONTEXT
  40   #define DECCNAME     "decContext"                     /* Short name */
  41   #define DECCFULLNAME "Decimal Context Descriptor"   /* Verbose name */
  42   #define DECCAUTHOR   "Mike Cowlishaw"               /* Who to blame */
  43
  44   #if !defined(int32_t)
  45     #include <stdint.h>            /* C99 standard integers           */
  46   #endif
  47   #include <stdio.h>               /* for printf, etc.                */
  48   #include <signal.h>              /* for traps                       */
  49
  50   /* Extended flags setting -- set this to 0 to use only IEEE flags   */
  51   #if !defined(DECEXTFLAG)
  52   #define DECEXTFLAG 1             /* 1=enable extended flags         */
  53   #endif
  54
  55   /* Conditional code flag -- set this to 0 for best performance      */
  56   #if !defined(DECSUBSET)
  57   #define DECSUBSET  0             /* 1=enable subset arithmetic      */
  58   #endif
  59
  60   /* Context for operations, with associated constants                */
  61   enum rounding {
  62     DEC_ROUND_CEILING,             /* round towards +infinity         */
  63     DEC_ROUND_UP,                  /* round away from 0               */
  64     DEC_ROUND_HALF_UP,             /* 0.5 rounds up                   */
  65     DEC_ROUND_HALF_EVEN,           /* 0.5 rounds to nearest even      */
  66     DEC_ROUND_HALF_DOWN,           /* 0.5 rounds down                 */
  67     DEC_ROUND_DOWN,                /* round towards 0 (truncate)      */
  68     DEC_ROUND_FLOOR,               /* round towards -infinity         */
  69     DEC_ROUND_05UP,                /* round for reround               */
  70     DEC_ROUND_MAX                  /* enum must be less than this     */
  71     };
  72   #define DEC_ROUND_DEFAULT DEC_ROUND_HALF_EVEN;
  73
  74   typedef struct {
  75     int32_t  digits;               /* working precision               */
  76     int32_t  emax;                 /* maximum positive exponent       */
  77     int32_t  emin;                 /* minimum negative exponent       */
  78     enum     rounding round;       /* rounding mode                   */
  79     uint32_t traps;                /* trap-enabler flags              */
  80     uint32_t status;               /* status flags                    */
  81     uint8_t  clamp;                /* flag: apply IEEE exponent clamp */
  82     #if DECSUBSET
  83     uint8_t  extended;             /* flag: special-values allowed    */
  84     #endif
  85     } decContext;
  86
  87   /* Maxima and Minima for context settings                           */
  88   #define DEC_MAX_DIGITS 999999999
  89   #define DEC_MIN_DIGITS         1
  90   #define DEC_MAX_EMAX   999999999
  91   #define DEC_MIN_EMAX           0
  92   #define DEC_MAX_EMIN           0
  93   #define DEC_MIN_EMIN  -999999999
  94   #define DEC_MAX_MATH      999999 /* max emax, etc., for math funcs. */
  95
  96   /* Classifications for decimal numbers, aligned with 754 (note that */
  97   /* 'normal' and 'subnormal' are meaningful only with a decContext   */
  98   /* or a fixed size format).                                         */
  99   enum decClass {
 100     DEC_CLASS_SNAN,
 101     DEC_CLASS_QNAN,
 102     DEC_CLASS_NEG_INF,
 103     DEC_CLASS_NEG_NORMAL,
 104     DEC_CLASS_NEG_SUBNORMAL,
 105     DEC_CLASS_NEG_ZERO,
 106     DEC_CLASS_POS_ZERO,
 107     DEC_CLASS_POS_SUBNORMAL,
 108     DEC_CLASS_POS_NORMAL,
 109     DEC_CLASS_POS_INF
 110     };
 111   /* Strings for the decClasses */
 112   #define DEC_ClassString_SN  "sNaN"
 113   #define DEC_ClassString_QN  "NaN"
 114   #define DEC_ClassString_NI  "-Infinity"
 115   #define DEC_ClassString_NN  "-Normal"
 116   #define DEC_ClassString_NS  "-Subnormal"
 117   #define DEC_ClassString_NZ  "-Zero"
 118   #define DEC_ClassString_PZ  "+Zero"
 119   #define DEC_ClassString_PS  "+Subnormal"
 120   #define DEC_ClassString_PN  "+Normal"
 121   #define DEC_ClassString_PI  "+Infinity"
 122   #define DEC_ClassString_UN  "Invalid"
 123
 124   /* Trap-enabler and Status flags (exceptional conditions), and      */
 125   /* their names.  The top byte is reserved for internal use          */
 126   #if DECEXTFLAG
 127     /* Extended flags */
 128     #define DEC_Conversion_syntax    0x00000001
 129     #define DEC_Division_by_zero     0x00000002
 130     #define DEC_Division_impossible  0x00000004
 131     #define DEC_Division_undefined   0x00000008
 132     #define DEC_Insufficient_storage 0x00000010 /* [when malloc fails]  */
 133     #define DEC_Inexact              0x00000020
 134     #define DEC_Invalid_context      0x00000040
 135     #define DEC_Invalid_operation    0x00000080
 136     #if DECSUBSET
 137     #define DEC_Lost_digits          0x00000100
 138     #endif
 139     #define DEC_Overflow             0x00000200
 140     #define DEC_Clamped              0x00000400
 141     #define DEC_Rounded              0x00000800
 142     #define DEC_Subnormal            0x00001000
 143     #define DEC_Underflow            0x00002000
 144   #else
 145     /* IEEE flags only */
 146     #define DEC_Conversion_syntax    0x00000010
 147     #define DEC_Division_by_zero     0x00000002
 148     #define DEC_Division_impossible  0x00000010
 149     #define DEC_Division_undefined   0x00000010
 150     #define DEC_Insufficient_storage 0x00000010 /* [when malloc fails]  */
 151     #define DEC_Inexact              0x00000001
 152     #define DEC_Invalid_context      0x00000010
 153     #define DEC_Invalid_operation    0x00000010
 154     #if DECSUBSET
 155     #define DEC_Lost_digits          0x00000000
 156     #endif
 157     #define DEC_Overflow             0x00000008
 158     #define DEC_Clamped              0x00000000
 159     #define DEC_Rounded              0x00000000
 160     #define DEC_Subnormal            0x00000000
 161     #define DEC_Underflow            0x00000004
 162   #endif
 163
 164   /* IEEE 754 groupings for the flags                                 */
 165   /* [DEC_Clamped, DEC_Lost_digits, DEC_Rounded, and DEC_Subnormal    */
 166   /* are not in IEEE 754]                                             */
 167   #define DEC_IEEE_754_Division_by_zero  (DEC_Division_by_zero)
 168   #if DECSUBSET
 169   #define DEC_IEEE_754_Inexact           (DEC_Inexact | DEC_Lost_digits)
 170   #else
 171   #define DEC_IEEE_754_Inexact           (DEC_Inexact)
 172   #endif
 173   #define DEC_IEEE_754_Invalid_operation (DEC_Conversion_syntax |     \
 174                                           DEC_Division_impossible |   \
 175                                           DEC_Division_undefined |    \
 176                                           DEC_Insufficient_storage |  \
 177                                           DEC_Invalid_context |       \
 178                                           DEC_Invalid_operation)
 179   #define DEC_IEEE_754_Overflow          (DEC_Overflow)
 180   #define DEC_IEEE_754_Underflow         (DEC_Underflow)
 181
 182   /* flags which are normally errors (result is qNaN, infinite, or 0) */
 183   #define DEC_Errors (DEC_IEEE_754_Division_by_zero |                 \
 184                       DEC_IEEE_754_Invalid_operation |                \
 185                       DEC_IEEE_754_Overflow | DEC_IEEE_754_Underflow)
 186   /* flags which cause a result to become qNaN                        */
 187   #define DEC_NaNs    DEC_IEEE_754_Invalid_operation
 188
 189   /* flags which are normally for information only (finite results)   */
 190   #if DECSUBSET
 191   #define DEC_Information (DEC_Clamped | DEC_Rounded | DEC_Inexact    \
 192                           | DEC_Lost_digits)
 193   #else
 194   #define DEC_Information (DEC_Clamped | DEC_Rounded | DEC_Inexact)
 195   #endif
 196
 197   /* IEEE 854 names (for compatibility with older decNumber versions) */
 198   #define DEC_IEEE_854_Division_by_zero  DEC_IEEE_754_Division_by_zero
 199   #define DEC_IEEE_854_Inexact           DEC_IEEE_754_Inexact
 200   #define DEC_IEEE_854_Invalid_operation DEC_IEEE_754_Invalid_operation
 201   #define DEC_IEEE_854_Overflow          DEC_IEEE_754_Overflow
 202   #define DEC_IEEE_854_Underflow         DEC_IEEE_754_Underflow
 203
 204   /* Name strings for the exceptional conditions                      */
 205   #define DEC_Condition_CS "Conversion syntax"
 206   #define DEC_Condition_DZ "Division by zero"
 207   #define DEC_Condition_DI "Division impossible"
 208   #define DEC_Condition_DU "Division undefined"
 209   #define DEC_Condition_IE "Inexact"
 210   #define DEC_Condition_IS "Insufficient storage"
 211   #define DEC_Condition_IC "Invalid context"
 212   #define DEC_Condition_IO "Invalid operation"
 213   #if DECSUBSET
 214   #define DEC_Condition_LD "Lost digits"
 215   #endif
 216   #define DEC_Condition_OV "Overflow"
 217   #define DEC_Condition_PA "Clamped"
 218   #define DEC_Condition_RO "Rounded"
 219   #define DEC_Condition_SU "Subnormal"
 220   #define DEC_Condition_UN "Underflow"
 221   #define DEC_Condition_ZE "No status"
 222   #define DEC_Condition_MU "Multiple status"
 223   #define DEC_Condition_Length 21  /* length of the longest string,   */
 224                                    /* including terminator            */
 225
 226   /* Initialization descriptors, used by decContextDefault            */
 227   #define DEC_INIT_BASE         0
 228   #define DEC_INIT_DECIMAL32   32
 229   #define DEC_INIT_DECIMAL64   64
 230   #define DEC_INIT_DECIMAL128 128
 231   /* Synonyms */
 232   #define DEC_INIT_DECSINGLE  DEC_INIT_DECIMAL32
 233   #define DEC_INIT_DECDOUBLE  DEC_INIT_DECIMAL64
 234   #define DEC_INIT_DECQUAD    DEC_INIT_DECIMAL128
 235
 236   /* decContext routines                                              */
 237   extern decContext  * decContextClearStatus(decContext *, uint32_t);
 238   extern decContext  * decContextDefault(decContext *, int32_t);
 239   extern enum rounding decContextGetRounding(decContext *);
 240   extern uint32_t      decContextGetStatus(decContext *);
 241   extern decContext  * decContextRestoreStatus(decContext *, uint32_t, uint32_t);
 242   extern uint32_t      decContextSaveStatus(decContext *, uint32_t);
 243   extern decContext  * decContextSetRounding(decContext *, enum rounding);
 244   extern decContext  * decContextSetStatus(decContext *, uint32_t);
 245   extern decContext  * decContextSetStatusFromString(decContext *, const char *);
 246   extern decContext  * decContextSetStatusFromStringQuiet(decContext *, const char *);
 247   extern decContext  * decContextSetStatusQuiet(decContext *, uint32_t);
 248   extern const char  * decContextStatusToString(const decContext *);
 249   extern int32_t       decContextTestEndian(uint8_t);
 250   extern uint32_t      decContextTestSavedStatus(uint32_t, uint32_t);
 251   extern uint32_t      decContextTestStatus(decContext *, uint32_t);
 252   extern decContext  * decContextZeroStatus(decContext *);
 253
 254 #endif