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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 */
5 : /* ------------------------------------------------------------------ */
6 : /* Copyright (c) IBM Corporation, 2000-2012. 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 : /* This module comprises the routines for handling arithmetic */
22 : /* context structures. */
23 : /* ------------------------------------------------------------------ */
24 :
25 : #include <string.h> /* for strcmp */
26 : #include <stdio.h> /* for printf if DECCHECK */
27 : #include "decContext.h" /* context and base types */
28 : #include "decNumberLocal.h" /* decNumber local types, etc. */
29 :
30 : #if 0 /* ICU: No need to test endianness at runtime. */
31 : /* compile-time endian tester [assumes sizeof(Int)>1] */
32 : static const Int mfcone=1; /* constant 1 */
33 : static const Flag *mfctop=(Flag *)&mfcone; /* -> top byte */
34 : #define LITEND *mfctop /* named flag; 1=little-endian */
35 : #endif
36 :
37 : /* ------------------------------------------------------------------ */
38 : /* decContextClearStatus -- clear bits in current status */
39 : /* */
40 : /* context is the context structure to be queried */
41 : /* mask indicates the bits to be cleared (the status bit that */
42 : /* corresponds to each 1 bit in the mask is cleared) */
43 : /* returns context */
44 : /* */
45 : /* No error is possible. */
46 : /* ------------------------------------------------------------------ */
47 0 : U_CAPI decContext * U_EXPORT2 uprv_decContextClearStatus(decContext *context, uInt mask) {
48 0 : context->status&=~mask;
49 0 : return context;
50 : } /* decContextClearStatus */
51 :
52 : /* ------------------------------------------------------------------ */
53 : /* decContextDefault -- initialize a context structure */
54 : /* */
55 : /* context is the structure to be initialized */
56 : /* kind selects the required set of default values, one of: */
57 : /* DEC_INIT_BASE -- select ANSI X3-274 defaults */
58 : /* DEC_INIT_DECIMAL32 -- select IEEE 754 defaults, 32-bit */
59 : /* DEC_INIT_DECIMAL64 -- select IEEE 754 defaults, 64-bit */
60 : /* DEC_INIT_DECIMAL128 -- select IEEE 754 defaults, 128-bit */
61 : /* For any other value a valid context is returned, but with */
62 : /* Invalid_operation set in the status field. */
63 : /* returns a context structure with the appropriate initial values. */
64 : /* ------------------------------------------------------------------ */
65 0 : U_CAPI decContext * U_EXPORT2 uprv_decContextDefault(decContext *context, Int kind) {
66 : /* set defaults... */
67 0 : context->digits=9; /* 9 digits */
68 0 : context->emax=DEC_MAX_EMAX; /* 9-digit exponents */
69 0 : context->emin=DEC_MIN_EMIN; /* .. balanced */
70 0 : context->round=DEC_ROUND_HALF_UP; /* 0.5 rises */
71 0 : context->traps=DEC_Errors; /* all but informational */
72 0 : context->status=0; /* cleared */
73 0 : context->clamp=0; /* no clamping */
74 : #if DECSUBSET
75 : context->extended=0; /* cleared */
76 : #endif
77 0 : switch (kind) {
78 : case DEC_INIT_BASE:
79 : /* [use defaults] */
80 0 : break;
81 : case DEC_INIT_DECIMAL32:
82 0 : context->digits=7; /* digits */
83 0 : context->emax=96; /* Emax */
84 0 : context->emin=-95; /* Emin */
85 0 : context->round=DEC_ROUND_HALF_EVEN; /* 0.5 to nearest even */
86 0 : context->traps=0; /* no traps set */
87 0 : context->clamp=1; /* clamp exponents */
88 : #if DECSUBSET
89 : context->extended=1; /* set */
90 : #endif
91 0 : break;
92 : case DEC_INIT_DECIMAL64:
93 0 : context->digits=16; /* digits */
94 0 : context->emax=384; /* Emax */
95 0 : context->emin=-383; /* Emin */
96 0 : context->round=DEC_ROUND_HALF_EVEN; /* 0.5 to nearest even */
97 0 : context->traps=0; /* no traps set */
98 0 : context->clamp=1; /* clamp exponents */
99 : #if DECSUBSET
100 : context->extended=1; /* set */
101 : #endif
102 0 : break;
103 : case DEC_INIT_DECIMAL128:
104 0 : context->digits=34; /* digits */
105 0 : context->emax=6144; /* Emax */
106 0 : context->emin=-6143; /* Emin */
107 0 : context->round=DEC_ROUND_HALF_EVEN; /* 0.5 to nearest even */
108 0 : context->traps=0; /* no traps set */
109 0 : context->clamp=1; /* clamp exponents */
110 : #if DECSUBSET
111 : context->extended=1; /* set */
112 : #endif
113 0 : break;
114 :
115 : default: /* invalid Kind */
116 : /* use defaults, and .. */
117 0 : uprv_decContextSetStatus(context, DEC_Invalid_operation); /* trap */
118 : }
119 :
120 0 : return context;} /* decContextDefault */
121 :
122 : /* ------------------------------------------------------------------ */
123 : /* decContextGetRounding -- return current rounding mode */
124 : /* */
125 : /* context is the context structure to be queried */
126 : /* returns the rounding mode */
127 : /* */
128 : /* No error is possible. */
129 : /* ------------------------------------------------------------------ */
130 0 : U_CAPI enum rounding U_EXPORT2 uprv_decContextGetRounding(decContext *context) {
131 0 : return context->round;
132 : } /* decContextGetRounding */
133 :
134 : /* ------------------------------------------------------------------ */
135 : /* decContextGetStatus -- return current status */
136 : /* */
137 : /* context is the context structure to be queried */
138 : /* returns status */
139 : /* */
140 : /* No error is possible. */
141 : /* ------------------------------------------------------------------ */
142 0 : U_CAPI uInt U_EXPORT2 uprv_decContextGetStatus(decContext *context) {
143 0 : return context->status;
144 : } /* decContextGetStatus */
145 :
146 : /* ------------------------------------------------------------------ */
147 : /* decContextRestoreStatus -- restore bits in current status */
148 : /* */
149 : /* context is the context structure to be updated */
150 : /* newstatus is the source for the bits to be restored */
151 : /* mask indicates the bits to be restored (the status bit that */
152 : /* corresponds to each 1 bit in the mask is set to the value of */
153 : /* the correspnding bit in newstatus) */
154 : /* returns context */
155 : /* */
156 : /* No error is possible. */
157 : /* ------------------------------------------------------------------ */
158 0 : U_CAPI decContext * U_EXPORT2 uprv_decContextRestoreStatus(decContext *context,
159 : uInt newstatus, uInt mask) {
160 0 : context->status&=~mask; /* clear the selected bits */
161 0 : context->status|=(mask&newstatus); /* or in the new bits */
162 0 : return context;
163 : } /* decContextRestoreStatus */
164 :
165 : /* ------------------------------------------------------------------ */
166 : /* decContextSaveStatus -- save bits in current status */
167 : /* */
168 : /* context is the context structure to be queried */
169 : /* mask indicates the bits to be saved (the status bits that */
170 : /* correspond to each 1 bit in the mask are saved) */
171 : /* returns the AND of the mask and the current status */
172 : /* */
173 : /* No error is possible. */
174 : /* ------------------------------------------------------------------ */
175 0 : U_CAPI uInt U_EXPORT2 uprv_decContextSaveStatus(decContext *context, uInt mask) {
176 0 : return context->status&mask;
177 : } /* decContextSaveStatus */
178 :
179 : /* ------------------------------------------------------------------ */
180 : /* decContextSetRounding -- set current rounding mode */
181 : /* */
182 : /* context is the context structure to be updated */
183 : /* newround is the value which will replace the current mode */
184 : /* returns context */
185 : /* */
186 : /* No error is possible. */
187 : /* ------------------------------------------------------------------ */
188 0 : U_CAPI decContext * U_EXPORT2 uprv_decContextSetRounding(decContext *context,
189 : enum rounding newround) {
190 0 : context->round=newround;
191 0 : return context;
192 : } /* decContextSetRounding */
193 :
194 : /* ------------------------------------------------------------------ */
195 : /* decContextSetStatus -- set status and raise trap if appropriate */
196 : /* */
197 : /* context is the context structure to be updated */
198 : /* status is the DEC_ exception code */
199 : /* returns the context structure */
200 : /* */
201 : /* Control may never return from this routine, if there is a signal */
202 : /* handler and it takes a long jump. */
203 : /* ------------------------------------------------------------------ */
204 0 : U_CAPI decContext * U_EXPORT2 uprv_decContextSetStatus(decContext *context, uInt status) {
205 0 : context->status|=status;
206 : #if 0 /* ICU: Do not raise signals. */
207 : if (status & context->traps) raise(SIGFPE);
208 : #endif
209 0 : return context;} /* decContextSetStatus */
210 :
211 : /* ------------------------------------------------------------------ */
212 : /* decContextSetStatusFromString -- set status from a string + trap */
213 : /* */
214 : /* context is the context structure to be updated */
215 : /* string is a string exactly equal to one that might be returned */
216 : /* by decContextStatusToString */
217 : /* */
218 : /* The status bit corresponding to the string is set, and a trap */
219 : /* is raised if appropriate. */
220 : /* */
221 : /* returns the context structure, unless the string is equal to */
222 : /* DEC_Condition_MU or is not recognized. In these cases NULL is */
223 : /* returned. */
224 : /* ------------------------------------------------------------------ */
225 0 : U_CAPI decContext * U_EXPORT2 uprv_decContextSetStatusFromString(decContext *context,
226 : const char *string) {
227 0 : if (strcmp(string, DEC_Condition_CS)==0)
228 0 : return uprv_decContextSetStatus(context, DEC_Conversion_syntax);
229 0 : if (strcmp(string, DEC_Condition_DZ)==0)
230 0 : return uprv_decContextSetStatus(context, DEC_Division_by_zero);
231 0 : if (strcmp(string, DEC_Condition_DI)==0)
232 0 : return uprv_decContextSetStatus(context, DEC_Division_impossible);
233 0 : if (strcmp(string, DEC_Condition_DU)==0)
234 0 : return uprv_decContextSetStatus(context, DEC_Division_undefined);
235 0 : if (strcmp(string, DEC_Condition_IE)==0)
236 0 : return uprv_decContextSetStatus(context, DEC_Inexact);
237 0 : if (strcmp(string, DEC_Condition_IS)==0)
238 0 : return uprv_decContextSetStatus(context, DEC_Insufficient_storage);
239 0 : if (strcmp(string, DEC_Condition_IC)==0)
240 0 : return uprv_decContextSetStatus(context, DEC_Invalid_context);
241 0 : if (strcmp(string, DEC_Condition_IO)==0)
242 0 : return uprv_decContextSetStatus(context, DEC_Invalid_operation);
243 : #if DECSUBSET
244 : if (strcmp(string, DEC_Condition_LD)==0)
245 : return uprv_decContextSetStatus(context, DEC_Lost_digits);
246 : #endif
247 0 : if (strcmp(string, DEC_Condition_OV)==0)
248 0 : return uprv_decContextSetStatus(context, DEC_Overflow);
249 0 : if (strcmp(string, DEC_Condition_PA)==0)
250 0 : return uprv_decContextSetStatus(context, DEC_Clamped);
251 0 : if (strcmp(string, DEC_Condition_RO)==0)
252 0 : return uprv_decContextSetStatus(context, DEC_Rounded);
253 0 : if (strcmp(string, DEC_Condition_SU)==0)
254 0 : return uprv_decContextSetStatus(context, DEC_Subnormal);
255 0 : if (strcmp(string, DEC_Condition_UN)==0)
256 0 : return uprv_decContextSetStatus(context, DEC_Underflow);
257 0 : if (strcmp(string, DEC_Condition_ZE)==0)
258 0 : return context;
259 0 : return NULL; /* Multiple status, or unknown */
260 : } /* decContextSetStatusFromString */
261 :
262 : /* ------------------------------------------------------------------ */
263 : /* decContextSetStatusFromStringQuiet -- set status from a string */
264 : /* */
265 : /* context is the context structure to be updated */
266 : /* string is a string exactly equal to one that might be returned */
267 : /* by decContextStatusToString */
268 : /* */
269 : /* The status bit corresponding to the string is set; no trap is */
270 : /* raised. */
271 : /* */
272 : /* returns the context structure, unless the string is equal to */
273 : /* DEC_Condition_MU or is not recognized. In these cases NULL is */
274 : /* returned. */
275 : /* ------------------------------------------------------------------ */
276 0 : U_CAPI decContext * U_EXPORT2 uprv_decContextSetStatusFromStringQuiet(decContext *context,
277 : const char *string) {
278 0 : if (strcmp(string, DEC_Condition_CS)==0)
279 0 : return uprv_decContextSetStatusQuiet(context, DEC_Conversion_syntax);
280 0 : if (strcmp(string, DEC_Condition_DZ)==0)
281 0 : return uprv_decContextSetStatusQuiet(context, DEC_Division_by_zero);
282 0 : if (strcmp(string, DEC_Condition_DI)==0)
283 0 : return uprv_decContextSetStatusQuiet(context, DEC_Division_impossible);
284 0 : if (strcmp(string, DEC_Condition_DU)==0)
285 0 : return uprv_decContextSetStatusQuiet(context, DEC_Division_undefined);
286 0 : if (strcmp(string, DEC_Condition_IE)==0)
287 0 : return uprv_decContextSetStatusQuiet(context, DEC_Inexact);
288 0 : if (strcmp(string, DEC_Condition_IS)==0)
289 0 : return uprv_decContextSetStatusQuiet(context, DEC_Insufficient_storage);
290 0 : if (strcmp(string, DEC_Condition_IC)==0)
291 0 : return uprv_decContextSetStatusQuiet(context, DEC_Invalid_context);
292 0 : if (strcmp(string, DEC_Condition_IO)==0)
293 0 : return uprv_decContextSetStatusQuiet(context, DEC_Invalid_operation);
294 : #if DECSUBSET
295 : if (strcmp(string, DEC_Condition_LD)==0)
296 : return uprv_decContextSetStatusQuiet(context, DEC_Lost_digits);
297 : #endif
298 0 : if (strcmp(string, DEC_Condition_OV)==0)
299 0 : return uprv_decContextSetStatusQuiet(context, DEC_Overflow);
300 0 : if (strcmp(string, DEC_Condition_PA)==0)
301 0 : return uprv_decContextSetStatusQuiet(context, DEC_Clamped);
302 0 : if (strcmp(string, DEC_Condition_RO)==0)
303 0 : return uprv_decContextSetStatusQuiet(context, DEC_Rounded);
304 0 : if (strcmp(string, DEC_Condition_SU)==0)
305 0 : return uprv_decContextSetStatusQuiet(context, DEC_Subnormal);
306 0 : if (strcmp(string, DEC_Condition_UN)==0)
307 0 : return uprv_decContextSetStatusQuiet(context, DEC_Underflow);
308 0 : if (strcmp(string, DEC_Condition_ZE)==0)
309 0 : return context;
310 0 : return NULL; /* Multiple status, or unknown */
311 : } /* decContextSetStatusFromStringQuiet */
312 :
313 : /* ------------------------------------------------------------------ */
314 : /* decContextSetStatusQuiet -- set status without trap */
315 : /* */
316 : /* context is the context structure to be updated */
317 : /* status is the DEC_ exception code */
318 : /* returns the context structure */
319 : /* */
320 : /* No error is possible. */
321 : /* ------------------------------------------------------------------ */
322 0 : U_CAPI decContext * U_EXPORT2 uprv_decContextSetStatusQuiet(decContext *context, uInt status) {
323 0 : context->status|=status;
324 0 : return context;} /* decContextSetStatusQuiet */
325 :
326 : /* ------------------------------------------------------------------ */
327 : /* decContextStatusToString -- convert status flags to a string */
328 : /* */
329 : /* context is a context with valid status field */
330 : /* */
331 : /* returns a constant string describing the condition. If multiple */
332 : /* (or no) flags are set, a generic constant message is returned. */
333 : /* ------------------------------------------------------------------ */
334 0 : U_CAPI const char * U_EXPORT2 uprv_decContextStatusToString(const decContext *context) {
335 0 : Int status=context->status;
336 :
337 : /* test the five IEEE first, as some of the others are ambiguous when */
338 : /* DECEXTFLAG=0 */
339 0 : if (status==DEC_Invalid_operation ) return DEC_Condition_IO;
340 0 : if (status==DEC_Division_by_zero ) return DEC_Condition_DZ;
341 0 : if (status==DEC_Overflow ) return DEC_Condition_OV;
342 0 : if (status==DEC_Underflow ) return DEC_Condition_UN;
343 0 : if (status==DEC_Inexact ) return DEC_Condition_IE;
344 :
345 0 : if (status==DEC_Division_impossible ) return DEC_Condition_DI;
346 0 : if (status==DEC_Division_undefined ) return DEC_Condition_DU;
347 0 : if (status==DEC_Rounded ) return DEC_Condition_RO;
348 0 : if (status==DEC_Clamped ) return DEC_Condition_PA;
349 0 : if (status==DEC_Subnormal ) return DEC_Condition_SU;
350 0 : if (status==DEC_Conversion_syntax ) return DEC_Condition_CS;
351 0 : if (status==DEC_Insufficient_storage ) return DEC_Condition_IS;
352 0 : if (status==DEC_Invalid_context ) return DEC_Condition_IC;
353 : #if DECSUBSET
354 : if (status==DEC_Lost_digits ) return DEC_Condition_LD;
355 : #endif
356 0 : if (status==0 ) return DEC_Condition_ZE;
357 0 : return DEC_Condition_MU; /* Multiple errors */
358 : } /* decContextStatusToString */
359 :
360 : /* ------------------------------------------------------------------ */
361 : /* decContextTestEndian -- test whether DECLITEND is set correctly */
362 : /* */
363 : /* quiet is 1 to suppress message; 0 otherwise */
364 : /* returns 0 if DECLITEND is correct */
365 : /* 1 if DECLITEND is incorrect and should be 1 */
366 : /* -1 if DECLITEND is incorrect and should be 0 */
367 : /* */
368 : /* A message is displayed if the return value is not 0 and quiet==0. */
369 : /* */
370 : /* No error is possible. */
371 : /* ------------------------------------------------------------------ */
372 : #if 0 /* ICU: Unused function. Anyway, do not call printf(). */
373 : U_CAPI Int U_EXPORT2 uprv_decContextTestEndian(Flag quiet) {
374 : Int res=0; /* optimist */
375 : uInt dle=(uInt)DECLITEND; /* unsign */
376 : if (dle>1) dle=1; /* ensure 0 or 1 */
377 :
378 : if (LITEND!=DECLITEND) {
379 : const char *adj;
380 : if (!quiet) {
381 : if (LITEND) adj="little";
382 : else adj="big";
383 : printf("Warning: DECLITEND is set to %d, but this computer appears to be %s-endian\n",
384 : DECLITEND, adj);
385 : }
386 : res=(Int)LITEND-dle;
387 : }
388 : return res;
389 : } /* decContextTestEndian */
390 : #endif
391 :
392 : /* ------------------------------------------------------------------ */
393 : /* decContextTestSavedStatus -- test bits in saved status */
394 : /* */
395 : /* oldstatus is the status word to be tested */
396 : /* mask indicates the bits to be tested (the oldstatus bits that */
397 : /* correspond to each 1 bit in the mask are tested) */
398 : /* returns 1 if any of the tested bits are 1, or 0 otherwise */
399 : /* */
400 : /* No error is possible. */
401 : /* ------------------------------------------------------------------ */
402 0 : U_CAPI uInt U_EXPORT2 uprv_decContextTestSavedStatus(uInt oldstatus, uInt mask) {
403 0 : return (oldstatus&mask)!=0;
404 : } /* decContextTestSavedStatus */
405 :
406 : /* ------------------------------------------------------------------ */
407 : /* decContextTestStatus -- test bits in current status */
408 : /* */
409 : /* context is the context structure to be updated */
410 : /* mask indicates the bits to be tested (the status bits that */
411 : /* correspond to each 1 bit in the mask are tested) */
412 : /* returns 1 if any of the tested bits are 1, or 0 otherwise */
413 : /* */
414 : /* No error is possible. */
415 : /* ------------------------------------------------------------------ */
416 0 : U_CAPI uInt U_EXPORT2 uprv_decContextTestStatus(decContext *context, uInt mask) {
417 0 : return (context->status&mask)!=0;
418 : } /* decContextTestStatus */
419 :
420 : /* ------------------------------------------------------------------ */
421 : /* decContextZeroStatus -- clear all status bits */
422 : /* */
423 : /* context is the context structure to be updated */
424 : /* returns context */
425 : /* */
426 : /* No error is possible. */
427 : /* ------------------------------------------------------------------ */
428 0 : U_CAPI decContext * U_EXPORT2 uprv_decContextZeroStatus(decContext *context) {
429 0 : context->status=0;
430 0 : return context;
431 : } /* decContextZeroStatus */
432 :
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