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1 // © 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 /* ------------------------------------------------------------------ */
4 /* Decimal Context module header                                      */
5 /* ------------------------------------------------------------------ */
6 /* Copyright (c) IBM Corporation, 2000-2011.   All rights reserved.   */
7 /*                                                                    */
8 /* This software is made available under the terms of the             */
9 /* ICU License -- ICU 1.8.1 and later.                                */
10 /*                                                                    */
11 /* The description and User's Guide ("The decNumber C Library") for   */
12 /* this software is called decNumber.pdf.  This document is           */
13 /* available, together with arithmetic and format specifications,     */
14 /* testcases, and Web links, on the General Decimal Arithmetic page.  */
15 /*                                                                    */
16 /* Please send comments, suggestions, and corrections to the author:  */
17 /*   mfc@uk.ibm.com                                                   */
18 /*   Mike Cowlishaw, IBM Fellow                                       */
19 /*   IBM UK, PO Box 31, Birmingham Road, Warwick CV34 5JL, UK         */
20 /* ------------------------------------------------------------------ */
21 
22 /* Modified version, for use from within ICU.
23  *    Renamed public functions, to avoid an unwanted export of the
24  *    standard names from the ICU library.
25  *
26  *    Use ICU's uprv_malloc() and uprv_free()
27  *
28  *    Revert comment syntax to plain C
29  *
30  *    Remove a few compiler warnings.
31  */
32 #include "unicode/utypes.h"
33 #include "putilimp.h"
34 
35 /*                                                                    */
36 /* Context variables must always have valid values:                   */
37 /*                                                                    */
38 /*  status   -- [any bits may be cleared, but not set, by user]       */
39 /*  round    -- must be one of the enumerated rounding modes          */
40 /*                                                                    */
41 /* The following variables are implied for fixed size formats (i.e.,  */
42 /* they are ignored) but should still be set correctly in case used   */
43 /* with decNumber functions:                                          */
44 /*                                                                    */
45 /*  clamp    -- must be either 0 or 1                                 */
46 /*  digits   -- must be in the range 1 through 999999999              */
47 /*  emax     -- must be in the range 0 through 999999999              */
48 /*  emin     -- must be in the range 0 through -999999999             */
49 /*  extended -- must be either 0 or 1 [present only if DECSUBSET]     */
50 /*  traps    -- only defined bits may be set                          */
51 /*                                                                    */
52 /* ------------------------------------------------------------------ */
53 
54 #if !defined(DECCONTEXT)
55   #define DECCONTEXT
56   #define DECCNAME     "decContext"                     /* Short name */
57   #define DECCFULLNAME "Decimal Context Descriptor"   /* Verbose name */
58   #define DECCAUTHOR   "Mike Cowlishaw"               /* Who to blame */
59 
60   #if !defined(int32_t)
61 /* #include <stdint.h>   */         /* C99 standard integers           */
62   #endif
63   #include <stdio.h>               /* for printf, etc.                */
64   #include <signal.h>              /* for traps                       */
65 
66   /* Extended flags setting -- set this to 0 to use only IEEE flags   */
67   #if !defined(DECEXTFLAG)
68   #define DECEXTFLAG 1             /* 1=enable extended flags         */
69   #endif
70 
71   /* Conditional code flag -- set this to 0 for best performance      */
72   #if !defined(DECSUBSET)
73   #define DECSUBSET  0             /* 1=enable subset arithmetic      */
74   #endif
75 
76   /* Context for operations, with associated constants                */
77   enum rounding {
78     DEC_ROUND_CEILING,             /* round towards +infinity         */
79     DEC_ROUND_UP,                  /* round away from 0               */
80     DEC_ROUND_HALF_UP,             /* 0.5 rounds up                   */
81     DEC_ROUND_HALF_EVEN,           /* 0.5 rounds to nearest even      */
82     DEC_ROUND_HALF_DOWN,           /* 0.5 rounds down                 */
83     DEC_ROUND_DOWN,                /* round towards 0 (truncate)      */
84     DEC_ROUND_FLOOR,               /* round towards -infinity         */
85     DEC_ROUND_05UP,                /* round for reround               */
86     DEC_ROUND_MAX                  /* enum must be less than this     */
87     };
88   #define DEC_ROUND_DEFAULT DEC_ROUND_HALF_EVEN;
89 
90   typedef struct {
91     int32_t  digits;               /* working precision               */
92     int32_t  emax;                 /* maximum positive exponent       */
93     int32_t  emin;                 /* minimum negative exponent       */
94     enum     rounding round;       /* rounding mode                   */
95     uint32_t traps;                /* trap-enabler flags              */
96     uint32_t status;               /* status flags                    */
97     uint8_t  clamp;                /* flag: apply IEEE exponent clamp */
98     #if DECSUBSET
99     uint8_t  extended;             /* flag: special-values allowed    */
100     #endif
101     } decContext;
102 
103   /* Maxima and Minima for context settings                           */
104   #define DEC_MAX_DIGITS 999999999
105   #define DEC_MIN_DIGITS         1
106   #define DEC_MAX_EMAX   999999999
107   #define DEC_MIN_EMAX           0
108   #define DEC_MAX_EMIN           0
109   #define DEC_MIN_EMIN  -999999999
110   #define DEC_MAX_MATH      999999 /* max emax, etc., for math funcs. */
111 
112   /* Classifications for decimal numbers, aligned with 754 (note that */
113   /* 'normal' and 'subnormal' are meaningful only with a decContext   */
114   /* or a fixed size format).                                         */
115   enum decClass {
116     DEC_CLASS_SNAN,
117     DEC_CLASS_QNAN,
118     DEC_CLASS_NEG_INF,
119     DEC_CLASS_NEG_NORMAL,
120     DEC_CLASS_NEG_SUBNORMAL,
121     DEC_CLASS_NEG_ZERO,
122     DEC_CLASS_POS_ZERO,
123     DEC_CLASS_POS_SUBNORMAL,
124     DEC_CLASS_POS_NORMAL,
125     DEC_CLASS_POS_INF
126     };
127   /* Strings for the decClasses */
128   #define DEC_ClassString_SN  "sNaN"
129   #define DEC_ClassString_QN  "NaN"
130   #define DEC_ClassString_NI  "-Infinity"
131   #define DEC_ClassString_NN  "-Normal"
132   #define DEC_ClassString_NS  "-Subnormal"
133   #define DEC_ClassString_NZ  "-Zero"
134   #define DEC_ClassString_PZ  "+Zero"
135   #define DEC_ClassString_PS  "+Subnormal"
136   #define DEC_ClassString_PN  "+Normal"
137   #define DEC_ClassString_PI  "+Infinity"
138   #define DEC_ClassString_UN  "Invalid"
139 
140   /* Trap-enabler and Status flags (exceptional conditions), and      */
141   /* their names.  The top byte is reserved for internal use          */
142   #if DECEXTFLAG
143     /* Extended flags */
144     #define DEC_Conversion_syntax    0x00000001
145     #define DEC_Division_by_zero     0x00000002
146     #define DEC_Division_impossible  0x00000004
147     #define DEC_Division_undefined   0x00000008
148     #define DEC_Insufficient_storage 0x00000010 /* [when malloc fails]  */
149     #define DEC_Inexact              0x00000020
150     #define DEC_Invalid_context      0x00000040
151     #define DEC_Invalid_operation    0x00000080
152     #if DECSUBSET
153     #define DEC_Lost_digits          0x00000100
154     #endif
155     #define DEC_Overflow             0x00000200
156     #define DEC_Clamped              0x00000400
157     #define DEC_Rounded              0x00000800
158     #define DEC_Subnormal            0x00001000
159     #define DEC_Underflow            0x00002000
160   #else
161     /* IEEE flags only */
162     #define DEC_Conversion_syntax    0x00000010
163     #define DEC_Division_by_zero     0x00000002
164     #define DEC_Division_impossible  0x00000010
165     #define DEC_Division_undefined   0x00000010
166     #define DEC_Insufficient_storage 0x00000010 /* [when malloc fails]  */
167     #define DEC_Inexact              0x00000001
168     #define DEC_Invalid_context      0x00000010
169     #define DEC_Invalid_operation    0x00000010
170     #if DECSUBSET
171     #define DEC_Lost_digits          0x00000000
172     #endif
173     #define DEC_Overflow             0x00000008
174     #define DEC_Clamped              0x00000000
175     #define DEC_Rounded              0x00000000
176     #define DEC_Subnormal            0x00000000
177     #define DEC_Underflow            0x00000004
178   #endif
179 
180   /* IEEE 754 groupings for the flags                                 */
181   /* [DEC_Clamped, DEC_Lost_digits, DEC_Rounded, and DEC_Subnormal    */
182   /* are not in IEEE 754]                                             */
183   #define DEC_IEEE_754_Division_by_zero  (DEC_Division_by_zero)
184   #if DECSUBSET
185   #define DEC_IEEE_754_Inexact           (DEC_Inexact | DEC_Lost_digits)
186   #else
187   #define DEC_IEEE_754_Inexact           (DEC_Inexact)
188   #endif
189   #define DEC_IEEE_754_Invalid_operation (DEC_Conversion_syntax |     \
190                                           DEC_Division_impossible |   \
191                                           DEC_Division_undefined |    \
192                                           DEC_Insufficient_storage |  \
193                                           DEC_Invalid_context |       \
194                                           DEC_Invalid_operation)
195   #define DEC_IEEE_754_Overflow          (DEC_Overflow)
196   #define DEC_IEEE_754_Underflow         (DEC_Underflow)
197 
198   /* flags which are normally errors (result is qNaN, infinite, or 0) */
199   #define DEC_Errors (DEC_IEEE_754_Division_by_zero |                 \
200                       DEC_IEEE_754_Invalid_operation |                \
201                       DEC_IEEE_754_Overflow | DEC_IEEE_754_Underflow)
202   /* flags which cause a result to become qNaN                        */
203   #define DEC_NaNs    DEC_IEEE_754_Invalid_operation
204 
205   /* flags which are normally for information only (finite results)   */
206   #if DECSUBSET
207   #define DEC_Information (DEC_Clamped | DEC_Rounded | DEC_Inexact    \
208                           | DEC_Lost_digits)
209   #else
210   #define DEC_Information (DEC_Clamped | DEC_Rounded | DEC_Inexact)
211   #endif
212 
213   /* IEEE 854 names (for compatibility with older decNumber versions) */
214   #define DEC_IEEE_854_Division_by_zero  DEC_IEEE_754_Division_by_zero
215   #define DEC_IEEE_854_Inexact           DEC_IEEE_754_Inexact
216   #define DEC_IEEE_854_Invalid_operation DEC_IEEE_754_Invalid_operation
217   #define DEC_IEEE_854_Overflow          DEC_IEEE_754_Overflow
218   #define DEC_IEEE_854_Underflow         DEC_IEEE_754_Underflow
219 
220   /* Name strings for the exceptional conditions                      */
221   #define DEC_Condition_CS "Conversion syntax"
222   #define DEC_Condition_DZ "Division by zero"
223   #define DEC_Condition_DI "Division impossible"
224   #define DEC_Condition_DU "Division undefined"
225   #define DEC_Condition_IE "Inexact"
226   #define DEC_Condition_IS "Insufficient storage"
227   #define DEC_Condition_IC "Invalid context"
228   #define DEC_Condition_IO "Invalid operation"
229   #if DECSUBSET
230   #define DEC_Condition_LD "Lost digits"
231   #endif
232   #define DEC_Condition_OV "Overflow"
233   #define DEC_Condition_PA "Clamped"
234   #define DEC_Condition_RO "Rounded"
235   #define DEC_Condition_SU "Subnormal"
236   #define DEC_Condition_UN "Underflow"
237   #define DEC_Condition_ZE "No status"
238   #define DEC_Condition_MU "Multiple status"
239   #define DEC_Condition_Length 21  /* length of the longest string,   */
240                                    /* including terminator            */
241 
242   /* Initialization descriptors, used by decContextDefault            */
243   #define DEC_INIT_BASE         0
244   #define DEC_INIT_DECIMAL32   32
245   #define DEC_INIT_DECIMAL64   64
246   #define DEC_INIT_DECIMAL128 128
247   /* Synonyms */
248   #define DEC_INIT_DECSINGLE  DEC_INIT_DECIMAL32
249   #define DEC_INIT_DECDOUBLE  DEC_INIT_DECIMAL64
250   #define DEC_INIT_DECQUAD    DEC_INIT_DECIMAL128
251 
252   /* decContext routines                                              */
253   U_INTERNAL decContext  * U_EXPORT2 uprv_decContextClearStatus(decContext *, uint32_t);
254   U_INTERNAL decContext  * U_EXPORT2 uprv_decContextDefault(decContext *, int32_t);
255   U_INTERNAL enum rounding U_EXPORT2 uprv_decContextGetRounding(decContext *);
256   U_INTERNAL uint32_t      U_EXPORT2 uprv_decContextGetStatus(decContext *);
257   U_INTERNAL decContext  * U_EXPORT2 uprv_decContextRestoreStatus(decContext *, uint32_t, uint32_t);
258   U_INTERNAL uint32_t      U_EXPORT2 uprv_decContextSaveStatus(decContext *, uint32_t);
259   U_INTERNAL decContext  * U_EXPORT2 uprv_decContextSetRounding(decContext *, enum rounding);
260   U_INTERNAL decContext  * U_EXPORT2 uprv_decContextSetStatus(decContext *, uint32_t);
261   U_INTERNAL decContext  * U_EXPORT2 uprv_decContextSetStatusFromString(decContext *, const char *);
262   U_INTERNAL decContext  * U_EXPORT2 uprv_decContextSetStatusFromStringQuiet(decContext *, const char *);
263   U_INTERNAL decContext  * U_EXPORT2 uprv_decContextSetStatusQuiet(decContext *, uint32_t);
264   U_INTERNAL const char  * U_EXPORT2 uprv_decContextStatusToString(const decContext *);
265   U_INTERNAL int32_t       U_EXPORT2 uprv_decContextTestEndian(uint8_t);
266   U_INTERNAL uint32_t      U_EXPORT2 uprv_decContextTestSavedStatus(uint32_t, uint32_t);
267   U_INTERNAL uint32_t      U_EXPORT2 uprv_decContextTestStatus(decContext *, uint32_t);
268   U_INTERNAL decContext  * U_EXPORT2 uprv_decContextZeroStatus(decContext *);
269 
270 #endif
271