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