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729e4ab9 A |
1 | /* ------------------------------------------------------------------ */ |
2 | /* Decimal Context module */ | |
3 | /* ------------------------------------------------------------------ */ | |
51004dcb | 4 | /* Copyright (c) IBM Corporation, 2000-2012. All rights reserved. */ |
729e4ab9 A |
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 | /* This module comprises the routines for handling arithmetic */ | |
20 | /* context structures. */ | |
21 | /* ------------------------------------------------------------------ */ | |
22 | ||
23 | #include <string.h> /* for strcmp */ | |
24 | #include <stdio.h> /* for printf if DECCHECK */ | |
25 | #include "decContext.h" /* context and base types */ | |
26 | #include "decNumberLocal.h" /* decNumber local types, etc. */ | |
27 | ||
4388f060 | 28 | #if 0 /* ICU: No need to test endianness at runtime. */ |
729e4ab9 A |
29 | /* compile-time endian tester [assumes sizeof(Int)>1] */ |
30 | static const Int mfcone=1; /* constant 1 */ | |
31 | static const Flag *mfctop=(Flag *)&mfcone; /* -> top byte */ | |
32 | #define LITEND *mfctop /* named flag; 1=little-endian */ | |
4388f060 | 33 | #endif |
729e4ab9 | 34 | |
729e4ab9 A |
35 | /* ------------------------------------------------------------------ */ |
36 | /* decContextClearStatus -- clear bits in current status */ | |
37 | /* */ | |
38 | /* context is the context structure to be queried */ | |
39 | /* mask indicates the bits to be cleared (the status bit that */ | |
40 | /* corresponds to each 1 bit in the mask is cleared) */ | |
41 | /* returns context */ | |
42 | /* */ | |
43 | /* No error is possible. */ | |
44 | /* ------------------------------------------------------------------ */ | |
45 | U_CAPI decContext * U_EXPORT2 uprv_decContextClearStatus(decContext *context, uInt mask) { | |
46 | context->status&=~mask; | |
47 | return context; | |
48 | } /* decContextClearStatus */ | |
49 | ||
50 | /* ------------------------------------------------------------------ */ | |
51 | /* decContextDefault -- initialize a context structure */ | |
52 | /* */ | |
53 | /* context is the structure to be initialized */ | |
54 | /* kind selects the required set of default values, one of: */ | |
55 | /* DEC_INIT_BASE -- select ANSI X3-274 defaults */ | |
56 | /* DEC_INIT_DECIMAL32 -- select IEEE 754 defaults, 32-bit */ | |
57 | /* DEC_INIT_DECIMAL64 -- select IEEE 754 defaults, 64-bit */ | |
58 | /* DEC_INIT_DECIMAL128 -- select IEEE 754 defaults, 128-bit */ | |
59 | /* For any other value a valid context is returned, but with */ | |
60 | /* Invalid_operation set in the status field. */ | |
61 | /* returns a context structure with the appropriate initial values. */ | |
62 | /* ------------------------------------------------------------------ */ | |
63 | U_CAPI decContext * U_EXPORT2 uprv_decContextDefault(decContext *context, Int kind) { | |
64 | /* set defaults... */ | |
65 | context->digits=9; /* 9 digits */ | |
66 | context->emax=DEC_MAX_EMAX; /* 9-digit exponents */ | |
67 | context->emin=DEC_MIN_EMIN; /* .. balanced */ | |
68 | context->round=DEC_ROUND_HALF_UP; /* 0.5 rises */ | |
69 | context->traps=DEC_Errors; /* all but informational */ | |
70 | context->status=0; /* cleared */ | |
71 | context->clamp=0; /* no clamping */ | |
72 | #if DECSUBSET | |
73 | context->extended=0; /* cleared */ | |
74 | #endif | |
75 | switch (kind) { | |
76 | case DEC_INIT_BASE: | |
77 | /* [use defaults] */ | |
78 | break; | |
79 | case DEC_INIT_DECIMAL32: | |
80 | context->digits=7; /* digits */ | |
81 | context->emax=96; /* Emax */ | |
82 | context->emin=-95; /* Emin */ | |
83 | context->round=DEC_ROUND_HALF_EVEN; /* 0.5 to nearest even */ | |
84 | context->traps=0; /* no traps set */ | |
85 | context->clamp=1; /* clamp exponents */ | |
86 | #if DECSUBSET | |
87 | context->extended=1; /* set */ | |
88 | #endif | |
89 | break; | |
90 | case DEC_INIT_DECIMAL64: | |
91 | context->digits=16; /* digits */ | |
92 | context->emax=384; /* Emax */ | |
93 | context->emin=-383; /* Emin */ | |
94 | context->round=DEC_ROUND_HALF_EVEN; /* 0.5 to nearest even */ | |
95 | context->traps=0; /* no traps set */ | |
96 | context->clamp=1; /* clamp exponents */ | |
97 | #if DECSUBSET | |
98 | context->extended=1; /* set */ | |
99 | #endif | |
100 | break; | |
101 | case DEC_INIT_DECIMAL128: | |
102 | context->digits=34; /* digits */ | |
103 | context->emax=6144; /* Emax */ | |
104 | context->emin=-6143; /* Emin */ | |
105 | context->round=DEC_ROUND_HALF_EVEN; /* 0.5 to nearest even */ | |
106 | context->traps=0; /* no traps set */ | |
107 | context->clamp=1; /* clamp exponents */ | |
108 | #if DECSUBSET | |
109 | context->extended=1; /* set */ | |
110 | #endif | |
111 | break; | |
112 | ||
113 | default: /* invalid Kind */ | |
114 | /* use defaults, and .. */ | |
115 | uprv_decContextSetStatus(context, DEC_Invalid_operation); /* trap */ | |
116 | } | |
117 | ||
118 | return context;} /* decContextDefault */ | |
119 | ||
120 | /* ------------------------------------------------------------------ */ | |
121 | /* decContextGetRounding -- return current rounding mode */ | |
122 | /* */ | |
123 | /* context is the context structure to be queried */ | |
124 | /* returns the rounding mode */ | |
125 | /* */ | |
126 | /* No error is possible. */ | |
127 | /* ------------------------------------------------------------------ */ | |
128 | U_CAPI enum rounding U_EXPORT2 uprv_decContextGetRounding(decContext *context) { | |
129 | return context->round; | |
130 | } /* decContextGetRounding */ | |
131 | ||
132 | /* ------------------------------------------------------------------ */ | |
133 | /* decContextGetStatus -- return current status */ | |
134 | /* */ | |
135 | /* context is the context structure to be queried */ | |
136 | /* returns status */ | |
137 | /* */ | |
138 | /* No error is possible. */ | |
139 | /* ------------------------------------------------------------------ */ | |
140 | U_CAPI uInt U_EXPORT2 uprv_decContextGetStatus(decContext *context) { | |
141 | return context->status; | |
142 | } /* decContextGetStatus */ | |
143 | ||
144 | /* ------------------------------------------------------------------ */ | |
145 | /* decContextRestoreStatus -- restore bits in current status */ | |
146 | /* */ | |
147 | /* context is the context structure to be updated */ | |
148 | /* newstatus is the source for the bits to be restored */ | |
149 | /* mask indicates the bits to be restored (the status bit that */ | |
150 | /* corresponds to each 1 bit in the mask is set to the value of */ | |
151 | /* the correspnding bit in newstatus) */ | |
152 | /* returns context */ | |
153 | /* */ | |
154 | /* No error is possible. */ | |
155 | /* ------------------------------------------------------------------ */ | |
156 | U_CAPI decContext * U_EXPORT2 uprv_decContextRestoreStatus(decContext *context, | |
157 | uInt newstatus, uInt mask) { | |
158 | context->status&=~mask; /* clear the selected bits */ | |
159 | context->status|=(mask&newstatus); /* or in the new bits */ | |
160 | return context; | |
161 | } /* decContextRestoreStatus */ | |
162 | ||
163 | /* ------------------------------------------------------------------ */ | |
164 | /* decContextSaveStatus -- save bits in current status */ | |
165 | /* */ | |
166 | /* context is the context structure to be queried */ | |
167 | /* mask indicates the bits to be saved (the status bits that */ | |
168 | /* correspond to each 1 bit in the mask are saved) */ | |
169 | /* returns the AND of the mask and the current status */ | |
170 | /* */ | |
171 | /* No error is possible. */ | |
172 | /* ------------------------------------------------------------------ */ | |
173 | U_CAPI uInt U_EXPORT2 uprv_decContextSaveStatus(decContext *context, uInt mask) { | |
174 | return context->status&mask; | |
175 | } /* decContextSaveStatus */ | |
176 | ||
177 | /* ------------------------------------------------------------------ */ | |
178 | /* decContextSetRounding -- set current rounding mode */ | |
179 | /* */ | |
180 | /* context is the context structure to be updated */ | |
181 | /* newround is the value which will replace the current mode */ | |
182 | /* returns context */ | |
183 | /* */ | |
184 | /* No error is possible. */ | |
185 | /* ------------------------------------------------------------------ */ | |
186 | U_CAPI decContext * U_EXPORT2 uprv_decContextSetRounding(decContext *context, | |
187 | enum rounding newround) { | |
188 | context->round=newround; | |
189 | return context; | |
190 | } /* decContextSetRounding */ | |
191 | ||
192 | /* ------------------------------------------------------------------ */ | |
193 | /* decContextSetStatus -- set status and raise trap if appropriate */ | |
194 | /* */ | |
195 | /* context is the context structure to be updated */ | |
196 | /* status is the DEC_ exception code */ | |
197 | /* returns the context structure */ | |
198 | /* */ | |
199 | /* Control may never return from this routine, if there is a signal */ | |
200 | /* handler and it takes a long jump. */ | |
201 | /* ------------------------------------------------------------------ */ | |
202 | U_CAPI decContext * U_EXPORT2 uprv_decContextSetStatus(decContext *context, uInt status) { | |
203 | context->status|=status; | |
4388f060 | 204 | #if 0 /* ICU: Do not raise signals. */ |
729e4ab9 | 205 | if (status & context->traps) raise(SIGFPE); |
4388f060 | 206 | #endif |
729e4ab9 A |
207 | return context;} /* decContextSetStatus */ |
208 | ||
209 | /* ------------------------------------------------------------------ */ | |
210 | /* decContextSetStatusFromString -- set status from a string + trap */ | |
211 | /* */ | |
212 | /* context is the context structure to be updated */ | |
213 | /* string is a string exactly equal to one that might be returned */ | |
214 | /* by decContextStatusToString */ | |
215 | /* */ | |
216 | /* The status bit corresponding to the string is set, and a trap */ | |
217 | /* is raised if appropriate. */ | |
218 | /* */ | |
219 | /* returns the context structure, unless the string is equal to */ | |
220 | /* DEC_Condition_MU or is not recognized. In these cases NULL is */ | |
221 | /* returned. */ | |
222 | /* ------------------------------------------------------------------ */ | |
223 | U_CAPI decContext * U_EXPORT2 uprv_decContextSetStatusFromString(decContext *context, | |
224 | const char *string) { | |
225 | if (strcmp(string, DEC_Condition_CS)==0) | |
226 | return uprv_decContextSetStatus(context, DEC_Conversion_syntax); | |
227 | if (strcmp(string, DEC_Condition_DZ)==0) | |
228 | return uprv_decContextSetStatus(context, DEC_Division_by_zero); | |
229 | if (strcmp(string, DEC_Condition_DI)==0) | |
230 | return uprv_decContextSetStatus(context, DEC_Division_impossible); | |
231 | if (strcmp(string, DEC_Condition_DU)==0) | |
232 | return uprv_decContextSetStatus(context, DEC_Division_undefined); | |
233 | if (strcmp(string, DEC_Condition_IE)==0) | |
234 | return uprv_decContextSetStatus(context, DEC_Inexact); | |
235 | if (strcmp(string, DEC_Condition_IS)==0) | |
236 | return uprv_decContextSetStatus(context, DEC_Insufficient_storage); | |
237 | if (strcmp(string, DEC_Condition_IC)==0) | |
238 | return uprv_decContextSetStatus(context, DEC_Invalid_context); | |
239 | if (strcmp(string, DEC_Condition_IO)==0) | |
240 | return uprv_decContextSetStatus(context, DEC_Invalid_operation); | |
241 | #if DECSUBSET | |
242 | if (strcmp(string, DEC_Condition_LD)==0) | |
243 | return uprv_decContextSetStatus(context, DEC_Lost_digits); | |
244 | #endif | |
245 | if (strcmp(string, DEC_Condition_OV)==0) | |
246 | return uprv_decContextSetStatus(context, DEC_Overflow); | |
247 | if (strcmp(string, DEC_Condition_PA)==0) | |
248 | return uprv_decContextSetStatus(context, DEC_Clamped); | |
249 | if (strcmp(string, DEC_Condition_RO)==0) | |
250 | return uprv_decContextSetStatus(context, DEC_Rounded); | |
251 | if (strcmp(string, DEC_Condition_SU)==0) | |
252 | return uprv_decContextSetStatus(context, DEC_Subnormal); | |
253 | if (strcmp(string, DEC_Condition_UN)==0) | |
254 | return uprv_decContextSetStatus(context, DEC_Underflow); | |
255 | if (strcmp(string, DEC_Condition_ZE)==0) | |
256 | return context; | |
257 | return NULL; /* Multiple status, or unknown */ | |
258 | } /* decContextSetStatusFromString */ | |
259 | ||
260 | /* ------------------------------------------------------------------ */ | |
261 | /* decContextSetStatusFromStringQuiet -- set status from a string */ | |
262 | /* */ | |
263 | /* context is the context structure to be updated */ | |
264 | /* string is a string exactly equal to one that might be returned */ | |
265 | /* by decContextStatusToString */ | |
266 | /* */ | |
267 | /* The status bit corresponding to the string is set; no trap is */ | |
268 | /* raised. */ | |
269 | /* */ | |
270 | /* returns the context structure, unless the string is equal to */ | |
271 | /* DEC_Condition_MU or is not recognized. In these cases NULL is */ | |
272 | /* returned. */ | |
273 | /* ------------------------------------------------------------------ */ | |
274 | U_CAPI decContext * U_EXPORT2 uprv_decContextSetStatusFromStringQuiet(decContext *context, | |
275 | const char *string) { | |
276 | if (strcmp(string, DEC_Condition_CS)==0) | |
277 | return uprv_decContextSetStatusQuiet(context, DEC_Conversion_syntax); | |
278 | if (strcmp(string, DEC_Condition_DZ)==0) | |
279 | return uprv_decContextSetStatusQuiet(context, DEC_Division_by_zero); | |
280 | if (strcmp(string, DEC_Condition_DI)==0) | |
281 | return uprv_decContextSetStatusQuiet(context, DEC_Division_impossible); | |
282 | if (strcmp(string, DEC_Condition_DU)==0) | |
283 | return uprv_decContextSetStatusQuiet(context, DEC_Division_undefined); | |
284 | if (strcmp(string, DEC_Condition_IE)==0) | |
285 | return uprv_decContextSetStatusQuiet(context, DEC_Inexact); | |
286 | if (strcmp(string, DEC_Condition_IS)==0) | |
287 | return uprv_decContextSetStatusQuiet(context, DEC_Insufficient_storage); | |
288 | if (strcmp(string, DEC_Condition_IC)==0) | |
289 | return uprv_decContextSetStatusQuiet(context, DEC_Invalid_context); | |
290 | if (strcmp(string, DEC_Condition_IO)==0) | |
291 | return uprv_decContextSetStatusQuiet(context, DEC_Invalid_operation); | |
292 | #if DECSUBSET | |
293 | if (strcmp(string, DEC_Condition_LD)==0) | |
294 | return uprv_decContextSetStatusQuiet(context, DEC_Lost_digits); | |
295 | #endif | |
296 | if (strcmp(string, DEC_Condition_OV)==0) | |
297 | return uprv_decContextSetStatusQuiet(context, DEC_Overflow); | |
298 | if (strcmp(string, DEC_Condition_PA)==0) | |
299 | return uprv_decContextSetStatusQuiet(context, DEC_Clamped); | |
300 | if (strcmp(string, DEC_Condition_RO)==0) | |
301 | return uprv_decContextSetStatusQuiet(context, DEC_Rounded); | |
302 | if (strcmp(string, DEC_Condition_SU)==0) | |
303 | return uprv_decContextSetStatusQuiet(context, DEC_Subnormal); | |
304 | if (strcmp(string, DEC_Condition_UN)==0) | |
305 | return uprv_decContextSetStatusQuiet(context, DEC_Underflow); | |
306 | if (strcmp(string, DEC_Condition_ZE)==0) | |
307 | return context; | |
308 | return NULL; /* Multiple status, or unknown */ | |
309 | } /* decContextSetStatusFromStringQuiet */ | |
310 | ||
311 | /* ------------------------------------------------------------------ */ | |
312 | /* decContextSetStatusQuiet -- set status without trap */ | |
313 | /* */ | |
314 | /* context is the context structure to be updated */ | |
315 | /* status is the DEC_ exception code */ | |
316 | /* returns the context structure */ | |
317 | /* */ | |
318 | /* No error is possible. */ | |
319 | /* ------------------------------------------------------------------ */ | |
320 | U_CAPI decContext * U_EXPORT2 uprv_decContextSetStatusQuiet(decContext *context, uInt status) { | |
321 | context->status|=status; | |
322 | return context;} /* decContextSetStatusQuiet */ | |
323 | ||
324 | /* ------------------------------------------------------------------ */ | |
325 | /* decContextStatusToString -- convert status flags to a string */ | |
326 | /* */ | |
327 | /* context is a context with valid status field */ | |
328 | /* */ | |
329 | /* returns a constant string describing the condition. If multiple */ | |
330 | /* (or no) flags are set, a generic constant message is returned. */ | |
331 | /* ------------------------------------------------------------------ */ | |
332 | U_CAPI const char * U_EXPORT2 uprv_decContextStatusToString(const decContext *context) { | |
333 | Int status=context->status; | |
334 | ||
335 | /* test the five IEEE first, as some of the others are ambiguous when */ | |
336 | /* DECEXTFLAG=0 */ | |
337 | if (status==DEC_Invalid_operation ) return DEC_Condition_IO; | |
338 | if (status==DEC_Division_by_zero ) return DEC_Condition_DZ; | |
339 | if (status==DEC_Overflow ) return DEC_Condition_OV; | |
340 | if (status==DEC_Underflow ) return DEC_Condition_UN; | |
341 | if (status==DEC_Inexact ) return DEC_Condition_IE; | |
342 | ||
343 | if (status==DEC_Division_impossible ) return DEC_Condition_DI; | |
344 | if (status==DEC_Division_undefined ) return DEC_Condition_DU; | |
345 | if (status==DEC_Rounded ) return DEC_Condition_RO; | |
346 | if (status==DEC_Clamped ) return DEC_Condition_PA; | |
347 | if (status==DEC_Subnormal ) return DEC_Condition_SU; | |
348 | if (status==DEC_Conversion_syntax ) return DEC_Condition_CS; | |
349 | if (status==DEC_Insufficient_storage ) return DEC_Condition_IS; | |
350 | if (status==DEC_Invalid_context ) return DEC_Condition_IC; | |
351 | #if DECSUBSET | |
352 | if (status==DEC_Lost_digits ) return DEC_Condition_LD; | |
353 | #endif | |
354 | if (status==0 ) return DEC_Condition_ZE; | |
355 | return DEC_Condition_MU; /* Multiple errors */ | |
356 | } /* decContextStatusToString */ | |
357 | ||
358 | /* ------------------------------------------------------------------ */ | |
359 | /* decContextTestEndian -- test whether DECLITEND is set correctly */ | |
360 | /* */ | |
361 | /* quiet is 1 to suppress message; 0 otherwise */ | |
362 | /* returns 0 if DECLITEND is correct */ | |
363 | /* 1 if DECLITEND is incorrect and should be 1 */ | |
364 | /* -1 if DECLITEND is incorrect and should be 0 */ | |
365 | /* */ | |
366 | /* A message is displayed if the return value is not 0 and quiet==0. */ | |
367 | /* */ | |
368 | /* No error is possible. */ | |
369 | /* ------------------------------------------------------------------ */ | |
4388f060 | 370 | #if 0 /* ICU: Unused function. Anyway, do not call printf(). */ |
729e4ab9 A |
371 | U_CAPI Int U_EXPORT2 uprv_decContextTestEndian(Flag quiet) { |
372 | Int res=0; /* optimist */ | |
373 | uInt dle=(uInt)DECLITEND; /* unsign */ | |
374 | if (dle>1) dle=1; /* ensure 0 or 1 */ | |
375 | ||
376 | if (LITEND!=DECLITEND) { | |
377 | const char *adj; | |
378 | if (!quiet) { | |
379 | if (LITEND) adj="little"; | |
380 | else adj="big"; | |
381 | printf("Warning: DECLITEND is set to %d, but this computer appears to be %s-endian\n", | |
382 | DECLITEND, adj); | |
383 | } | |
384 | res=(Int)LITEND-dle; | |
385 | } | |
386 | return res; | |
387 | } /* decContextTestEndian */ | |
4388f060 | 388 | #endif |
729e4ab9 A |
389 | |
390 | /* ------------------------------------------------------------------ */ | |
391 | /* decContextTestSavedStatus -- test bits in saved status */ | |
392 | /* */ | |
393 | /* oldstatus is the status word to be tested */ | |
394 | /* mask indicates the bits to be tested (the oldstatus bits that */ | |
395 | /* correspond to each 1 bit in the mask are tested) */ | |
396 | /* returns 1 if any of the tested bits are 1, or 0 otherwise */ | |
397 | /* */ | |
398 | /* No error is possible. */ | |
399 | /* ------------------------------------------------------------------ */ | |
400 | U_CAPI uInt U_EXPORT2 uprv_decContextTestSavedStatus(uInt oldstatus, uInt mask) { | |
401 | return (oldstatus&mask)!=0; | |
402 | } /* decContextTestSavedStatus */ | |
403 | ||
404 | /* ------------------------------------------------------------------ */ | |
405 | /* decContextTestStatus -- test bits in current status */ | |
406 | /* */ | |
407 | /* context is the context structure to be updated */ | |
408 | /* mask indicates the bits to be tested (the status bits that */ | |
409 | /* correspond to each 1 bit in the mask are tested) */ | |
410 | /* returns 1 if any of the tested bits are 1, or 0 otherwise */ | |
411 | /* */ | |
412 | /* No error is possible. */ | |
413 | /* ------------------------------------------------------------------ */ | |
414 | U_CAPI uInt U_EXPORT2 uprv_decContextTestStatus(decContext *context, uInt mask) { | |
415 | return (context->status&mask)!=0; | |
416 | } /* decContextTestStatus */ | |
417 | ||
418 | /* ------------------------------------------------------------------ */ | |
419 | /* decContextZeroStatus -- clear all status bits */ | |
420 | /* */ | |
421 | /* context is the context structure to be updated */ | |
422 | /* returns context */ | |
423 | /* */ | |
424 | /* No error is possible. */ | |
425 | /* ------------------------------------------------------------------ */ | |
426 | U_CAPI decContext * U_EXPORT2 uprv_decContextZeroStatus(decContext *context) { | |
427 | context->status=0; | |
428 | return context; | |
429 | } /* decContextZeroStatus */ | |
430 |