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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] */
30static const Int mfcone=1; /* constant 1 */
31static 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/* ------------------------------------------------------------------ */
45U_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/* ------------------------------------------------------------------ */
63U_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/* ------------------------------------------------------------------ */
128U_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/* ------------------------------------------------------------------ */
140U_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/* ------------------------------------------------------------------ */
156U_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/* ------------------------------------------------------------------ */
173U_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/* ------------------------------------------------------------------ */
186U_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/* ------------------------------------------------------------------ */
202U_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/* ------------------------------------------------------------------ */
223U_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/* ------------------------------------------------------------------ */
274U_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/* ------------------------------------------------------------------ */
320U_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/* ------------------------------------------------------------------ */
332U_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		 371U_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/* ------------------------------------------------------------------ */
400U_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/* ------------------------------------------------------------------ */
414U_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/* ------------------------------------------------------------------ */
426U_CAPI decContext * U_EXPORT2 uprv_decContextZeroStatus(decContext *context) {
427 context->status=0;
428 return context;
429 } /* decContextZeroStatus */
430
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