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
268