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f5bc1778 | 1 | /* Decimal context module for the decNumber C Library. |
168a2f77 | 2 | Copyright (C) 2005, 2007, 2009 Free Software Foundation, Inc. |
f5bc1778 DJ |
3 | Contributed by IBM Corporation. Author Mike Cowlishaw. |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it under | |
8 | the terms of the GNU General Public License as published by the Free | |
168a2f77 | 9 | Software Foundation; either version 3, or (at your option) any later |
f5bc1778 DJ |
10 | version. |
11 | ||
f5bc1778 DJ |
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
16 | ||
168a2f77 DD |
17 | Under Section 7 of GPL version 3, you are granted additional |
18 | permissions described in the GCC Runtime Library Exception, version | |
19 | 3.1, as published by the Free Software Foundation. | |
20 | ||
21 | You should have received a copy of the GNU General Public License and | |
22 | a copy of the GCC Runtime Library Exception along with this program; | |
23 | see the files COPYING3 and COPYING.RUNTIME respectively. If not, see | |
24 | <http://www.gnu.org/licenses/>. */ | |
f5bc1778 DJ |
25 | |
26 | /* ------------------------------------------------------------------ */ | |
27 | /* Decimal Context module */ | |
28 | /* ------------------------------------------------------------------ */ | |
29 | /* This module comprises the routines for handling arithmetic */ | |
30 | /* context structures. */ | |
31 | /* ------------------------------------------------------------------ */ | |
32 | ||
33 | #include <string.h> /* for strcmp */ | |
34 | #include <stdio.h> /* for printf if DECCHECK */ | |
5f5dfcbe | 35 | #include "dconfig.h" /* for GCC definitions */ |
87d32bb7 | 36 | #include "decContext.h" /* context and base types */ |
f5bc1778 DJ |
37 | #include "decNumberLocal.h" /* decNumber local types, etc. */ |
38 | ||
f5bc1778 DJ |
39 | /* compile-time endian tester [assumes sizeof(Int)>1] */ |
40 | static const Int mfcone=1; /* constant 1 */ | |
87d32bb7 | 41 | static const Flag *mfctop=(const Flag *)&mfcone; /* -> top byte */ |
f5bc1778 | 42 | #define LITEND *mfctop /* named flag; 1=little-endian */ |
f5bc1778 DJ |
43 | |
44 | /* ------------------------------------------------------------------ */ | |
45 | /* round-for-reround digits */ | |
46 | /* ------------------------------------------------------------------ */ | |
47 | const uByte DECSTICKYTAB[10]={1,1,2,3,4,6,6,7,8,9}; /* used if sticky */ | |
48 | ||
49 | /* ------------------------------------------------------------------ */ | |
50 | /* Powers of ten (powers[n]==10**n, 0<=n<=9) */ | |
51 | /* ------------------------------------------------------------------ */ | |
52 | const uInt DECPOWERS[10]={1, 10, 100, 1000, 10000, 100000, 1000000, | |
53 | 10000000, 100000000, 1000000000}; | |
54 | ||
55 | /* ------------------------------------------------------------------ */ | |
56 | /* decContextClearStatus -- clear bits in current status */ | |
57 | /* */ | |
58 | /* context is the context structure to be queried */ | |
59 | /* mask indicates the bits to be cleared (the status bit that */ | |
87d32bb7 | 60 | /* corresponds to each 1 bit in the mask is cleared) */ |
f5bc1778 DJ |
61 | /* returns context */ |
62 | /* */ | |
63 | /* No error is possible. */ | |
64 | /* ------------------------------------------------------------------ */ | |
65 | decContext *decContextClearStatus(decContext *context, uInt mask) { | |
66 | context->status&=~mask; | |
67 | return context; | |
68 | } /* decContextClearStatus */ | |
69 | ||
70 | /* ------------------------------------------------------------------ */ | |
71 | /* decContextDefault -- initialize a context structure */ | |
72 | /* */ | |
73 | /* context is the structure to be initialized */ | |
74 | /* kind selects the required set of default values, one of: */ | |
75 | /* DEC_INIT_BASE -- select ANSI X3-274 defaults */ | |
87d32bb7 DD |
76 | /* DEC_INIT_DECIMAL32 -- select IEEE 754 defaults, 32-bit */ |
77 | /* DEC_INIT_DECIMAL64 -- select IEEE 754 defaults, 64-bit */ | |
78 | /* DEC_INIT_DECIMAL128 -- select IEEE 754 defaults, 128-bit */ | |
f5bc1778 DJ |
79 | /* For any other value a valid context is returned, but with */ |
80 | /* Invalid_operation set in the status field. */ | |
81 | /* returns a context structure with the appropriate initial values. */ | |
82 | /* ------------------------------------------------------------------ */ | |
83 | decContext * decContextDefault(decContext *context, Int kind) { | |
84 | /* set defaults... */ | |
85 | context->digits=9; /* 9 digits */ | |
86 | context->emax=DEC_MAX_EMAX; /* 9-digit exponents */ | |
87 | context->emin=DEC_MIN_EMIN; /* .. balanced */ | |
88 | context->round=DEC_ROUND_HALF_UP; /* 0.5 rises */ | |
89 | context->traps=DEC_Errors; /* all but informational */ | |
90 | context->status=0; /* cleared */ | |
91 | context->clamp=0; /* no clamping */ | |
92 | #if DECSUBSET | |
93 | context->extended=0; /* cleared */ | |
94 | #endif | |
95 | switch (kind) { | |
96 | case DEC_INIT_BASE: | |
97 | /* [use defaults] */ | |
98 | break; | |
99 | case DEC_INIT_DECIMAL32: | |
100 | context->digits=7; /* digits */ | |
87d32bb7 | 101 | context->emax=96; /* Emax */ |
f5bc1778 DJ |
102 | context->emin=-95; /* Emin */ |
103 | context->round=DEC_ROUND_HALF_EVEN; /* 0.5 to nearest even */ | |
87d32bb7 DD |
104 | context->traps=0; /* no traps set */ |
105 | context->clamp=1; /* clamp exponents */ | |
f5bc1778 DJ |
106 | #if DECSUBSET |
107 | context->extended=1; /* set */ | |
108 | #endif | |
109 | break; | |
110 | case DEC_INIT_DECIMAL64: | |
111 | context->digits=16; /* digits */ | |
112 | context->emax=384; /* Emax */ | |
113 | context->emin=-383; /* Emin */ | |
114 | context->round=DEC_ROUND_HALF_EVEN; /* 0.5 to nearest even */ | |
87d32bb7 DD |
115 | context->traps=0; /* no traps set */ |
116 | context->clamp=1; /* clamp exponents */ | |
f5bc1778 DJ |
117 | #if DECSUBSET |
118 | context->extended=1; /* set */ | |
119 | #endif | |
120 | break; | |
121 | case DEC_INIT_DECIMAL128: | |
122 | context->digits=34; /* digits */ | |
123 | context->emax=6144; /* Emax */ | |
124 | context->emin=-6143; /* Emin */ | |
125 | context->round=DEC_ROUND_HALF_EVEN; /* 0.5 to nearest even */ | |
87d32bb7 DD |
126 | context->traps=0; /* no traps set */ |
127 | context->clamp=1; /* clamp exponents */ | |
f5bc1778 DJ |
128 | #if DECSUBSET |
129 | context->extended=1; /* set */ | |
130 | #endif | |
131 | break; | |
132 | ||
133 | default: /* invalid Kind */ | |
134 | /* use defaults, and .. */ | |
135 | decContextSetStatus(context, DEC_Invalid_operation); /* trap */ | |
136 | } | |
137 | ||
f5bc1778 DJ |
138 | return context;} /* decContextDefault */ |
139 | ||
140 | /* ------------------------------------------------------------------ */ | |
141 | /* decContextGetRounding -- return current rounding mode */ | |
142 | /* */ | |
143 | /* context is the context structure to be queried */ | |
144 | /* returns the rounding mode */ | |
145 | /* */ | |
146 | /* No error is possible. */ | |
147 | /* ------------------------------------------------------------------ */ | |
148 | enum rounding decContextGetRounding(decContext *context) { | |
149 | return context->round; | |
150 | } /* decContextGetRounding */ | |
151 | ||
152 | /* ------------------------------------------------------------------ */ | |
87d32bb7 | 153 | /* decContextGetStatus -- return current status */ |
f5bc1778 DJ |
154 | /* */ |
155 | /* context is the context structure to be queried */ | |
156 | /* returns status */ | |
157 | /* */ | |
158 | /* No error is possible. */ | |
159 | /* ------------------------------------------------------------------ */ | |
160 | uInt decContextGetStatus(decContext *context) { | |
161 | return context->status; | |
162 | } /* decContextGetStatus */ | |
163 | ||
164 | /* ------------------------------------------------------------------ */ | |
165 | /* decContextRestoreStatus -- restore bits in current status */ | |
166 | /* */ | |
167 | /* context is the context structure to be updated */ | |
87d32bb7 DD |
168 | /* newstatus is the source for the bits to be restored */ |
169 | /* mask indicates the bits to be restored (the status bit that */ | |
f5bc1778 DJ |
170 | /* corresponds to each 1 bit in the mask is set to the value of */ |
171 | /* the correspnding bit in newstatus) */ | |
172 | /* returns context */ | |
173 | /* */ | |
174 | /* No error is possible. */ | |
175 | /* ------------------------------------------------------------------ */ | |
176 | decContext *decContextRestoreStatus(decContext *context, | |
177 | uInt newstatus, uInt mask) { | |
178 | context->status&=~mask; /* clear the selected bits */ | |
179 | context->status|=(mask&newstatus); /* or in the new bits */ | |
180 | return context; | |
181 | } /* decContextRestoreStatus */ | |
182 | ||
183 | /* ------------------------------------------------------------------ */ | |
184 | /* decContextSaveStatus -- save bits in current status */ | |
185 | /* */ | |
186 | /* context is the context structure to be queried */ | |
187 | /* mask indicates the bits to be saved (the status bits that */ | |
188 | /* correspond to each 1 bit in the mask are saved) */ | |
189 | /* returns the AND of the mask and the current status */ | |
190 | /* */ | |
191 | /* No error is possible. */ | |
192 | /* ------------------------------------------------------------------ */ | |
193 | uInt decContextSaveStatus(decContext *context, uInt mask) { | |
194 | return context->status&mask; | |
195 | } /* decContextSaveStatus */ | |
196 | ||
197 | /* ------------------------------------------------------------------ */ | |
198 | /* decContextSetRounding -- set current rounding mode */ | |
199 | /* */ | |
200 | /* context is the context structure to be updated */ | |
201 | /* newround is the value which will replace the current mode */ | |
202 | /* returns context */ | |
203 | /* */ | |
204 | /* No error is possible. */ | |
205 | /* ------------------------------------------------------------------ */ | |
206 | decContext *decContextSetRounding(decContext *context, | |
207 | enum rounding newround) { | |
208 | context->round=newround; | |
209 | return context; | |
210 | } /* decContextSetRounding */ | |
211 | ||
212 | /* ------------------------------------------------------------------ */ | |
213 | /* decContextSetStatus -- set status and raise trap if appropriate */ | |
214 | /* */ | |
215 | /* context is the context structure to be updated */ | |
216 | /* status is the DEC_ exception code */ | |
217 | /* returns the context structure */ | |
218 | /* */ | |
219 | /* Control may never return from this routine, if there is a signal */ | |
220 | /* handler and it takes a long jump. */ | |
221 | /* ------------------------------------------------------------------ */ | |
222 | decContext * decContextSetStatus(decContext *context, uInt status) { | |
223 | context->status|=status; | |
224 | if (status & context->traps) raise(SIGFPE); | |
225 | return context;} /* decContextSetStatus */ | |
226 | ||
227 | /* ------------------------------------------------------------------ */ | |
228 | /* decContextSetStatusFromString -- set status from a string + trap */ | |
229 | /* */ | |
230 | /* context is the context structure to be updated */ | |
231 | /* string is a string exactly equal to one that might be returned */ | |
232 | /* by decContextStatusToString */ | |
233 | /* */ | |
234 | /* The status bit corresponding to the string is set, and a trap */ | |
235 | /* is raised if appropriate. */ | |
236 | /* */ | |
237 | /* returns the context structure, unless the string is equal to */ | |
238 | /* DEC_Condition_MU or is not recognized. In these cases NULL is */ | |
87d32bb7 | 239 | /* returned. */ |
f5bc1778 DJ |
240 | /* ------------------------------------------------------------------ */ |
241 | decContext * decContextSetStatusFromString(decContext *context, | |
242 | const char *string) { | |
243 | if (strcmp(string, DEC_Condition_CS)==0) | |
244 | return decContextSetStatus(context, DEC_Conversion_syntax); | |
245 | if (strcmp(string, DEC_Condition_DZ)==0) | |
246 | return decContextSetStatus(context, DEC_Division_by_zero); | |
247 | if (strcmp(string, DEC_Condition_DI)==0) | |
248 | return decContextSetStatus(context, DEC_Division_impossible); | |
249 | if (strcmp(string, DEC_Condition_DU)==0) | |
250 | return decContextSetStatus(context, DEC_Division_undefined); | |
251 | if (strcmp(string, DEC_Condition_IE)==0) | |
252 | return decContextSetStatus(context, DEC_Inexact); | |
253 | if (strcmp(string, DEC_Condition_IS)==0) | |
254 | return decContextSetStatus(context, DEC_Insufficient_storage); | |
255 | if (strcmp(string, DEC_Condition_IC)==0) | |
256 | return decContextSetStatus(context, DEC_Invalid_context); | |
257 | if (strcmp(string, DEC_Condition_IO)==0) | |
258 | return decContextSetStatus(context, DEC_Invalid_operation); | |
259 | #if DECSUBSET | |
260 | if (strcmp(string, DEC_Condition_LD)==0) | |
261 | return decContextSetStatus(context, DEC_Lost_digits); | |
262 | #endif | |
263 | if (strcmp(string, DEC_Condition_OV)==0) | |
264 | return decContextSetStatus(context, DEC_Overflow); | |
265 | if (strcmp(string, DEC_Condition_PA)==0) | |
266 | return decContextSetStatus(context, DEC_Clamped); | |
267 | if (strcmp(string, DEC_Condition_RO)==0) | |
268 | return decContextSetStatus(context, DEC_Rounded); | |
269 | if (strcmp(string, DEC_Condition_SU)==0) | |
270 | return decContextSetStatus(context, DEC_Subnormal); | |
271 | if (strcmp(string, DEC_Condition_UN)==0) | |
272 | return decContextSetStatus(context, DEC_Underflow); | |
273 | if (strcmp(string, DEC_Condition_ZE)==0) | |
274 | return context; | |
275 | return NULL; /* Multiple status, or unknown */ | |
276 | } /* decContextSetStatusFromString */ | |
277 | ||
278 | /* ------------------------------------------------------------------ */ | |
279 | /* decContextSetStatusFromStringQuiet -- set status from a string */ | |
280 | /* */ | |
281 | /* context is the context structure to be updated */ | |
282 | /* string is a string exactly equal to one that might be returned */ | |
283 | /* by decContextStatusToString */ | |
284 | /* */ | |
285 | /* The status bit corresponding to the string is set; no trap is */ | |
286 | /* raised. */ | |
287 | /* */ | |
288 | /* returns the context structure, unless the string is equal to */ | |
289 | /* DEC_Condition_MU or is not recognized. In these cases NULL is */ | |
87d32bb7 | 290 | /* returned. */ |
f5bc1778 DJ |
291 | /* ------------------------------------------------------------------ */ |
292 | decContext * decContextSetStatusFromStringQuiet(decContext *context, | |
293 | const char *string) { | |
294 | if (strcmp(string, DEC_Condition_CS)==0) | |
295 | return decContextSetStatusQuiet(context, DEC_Conversion_syntax); | |
296 | if (strcmp(string, DEC_Condition_DZ)==0) | |
297 | return decContextSetStatusQuiet(context, DEC_Division_by_zero); | |
298 | if (strcmp(string, DEC_Condition_DI)==0) | |
299 | return decContextSetStatusQuiet(context, DEC_Division_impossible); | |
300 | if (strcmp(string, DEC_Condition_DU)==0) | |
301 | return decContextSetStatusQuiet(context, DEC_Division_undefined); | |
302 | if (strcmp(string, DEC_Condition_IE)==0) | |
303 | return decContextSetStatusQuiet(context, DEC_Inexact); | |
304 | if (strcmp(string, DEC_Condition_IS)==0) | |
305 | return decContextSetStatusQuiet(context, DEC_Insufficient_storage); | |
306 | if (strcmp(string, DEC_Condition_IC)==0) | |
307 | return decContextSetStatusQuiet(context, DEC_Invalid_context); | |
308 | if (strcmp(string, DEC_Condition_IO)==0) | |
309 | return decContextSetStatusQuiet(context, DEC_Invalid_operation); | |
310 | #if DECSUBSET | |
311 | if (strcmp(string, DEC_Condition_LD)==0) | |
312 | return decContextSetStatusQuiet(context, DEC_Lost_digits); | |
313 | #endif | |
314 | if (strcmp(string, DEC_Condition_OV)==0) | |
315 | return decContextSetStatusQuiet(context, DEC_Overflow); | |
316 | if (strcmp(string, DEC_Condition_PA)==0) | |
317 | return decContextSetStatusQuiet(context, DEC_Clamped); | |
318 | if (strcmp(string, DEC_Condition_RO)==0) | |
319 | return decContextSetStatusQuiet(context, DEC_Rounded); | |
320 | if (strcmp(string, DEC_Condition_SU)==0) | |
321 | return decContextSetStatusQuiet(context, DEC_Subnormal); | |
322 | if (strcmp(string, DEC_Condition_UN)==0) | |
323 | return decContextSetStatusQuiet(context, DEC_Underflow); | |
324 | if (strcmp(string, DEC_Condition_ZE)==0) | |
325 | return context; | |
326 | return NULL; /* Multiple status, or unknown */ | |
327 | } /* decContextSetStatusFromStringQuiet */ | |
328 | ||
329 | /* ------------------------------------------------------------------ */ | |
330 | /* decContextSetStatusQuiet -- set status without trap */ | |
331 | /* */ | |
332 | /* context is the context structure to be updated */ | |
333 | /* status is the DEC_ exception code */ | |
334 | /* returns the context structure */ | |
335 | /* */ | |
336 | /* No error is possible. */ | |
337 | /* ------------------------------------------------------------------ */ | |
338 | decContext * decContextSetStatusQuiet(decContext *context, uInt status) { | |
339 | context->status|=status; | |
340 | return context;} /* decContextSetStatusQuiet */ | |
341 | ||
342 | /* ------------------------------------------------------------------ */ | |
87d32bb7 | 343 | /* decContextStatusToString -- convert status flags to a string */ |
f5bc1778 DJ |
344 | /* */ |
345 | /* context is a context with valid status field */ | |
346 | /* */ | |
87d32bb7 | 347 | /* returns a constant string describing the condition. If multiple */ |
f5bc1778 DJ |
348 | /* (or no) flags are set, a generic constant message is returned. */ |
349 | /* ------------------------------------------------------------------ */ | |
350 | const char *decContextStatusToString(const decContext *context) { | |
351 | Int status=context->status; | |
352 | ||
353 | /* test the five IEEE first, as some of the others are ambiguous when */ | |
354 | /* DECEXTFLAG=0 */ | |
355 | if (status==DEC_Invalid_operation ) return DEC_Condition_IO; | |
356 | if (status==DEC_Division_by_zero ) return DEC_Condition_DZ; | |
357 | if (status==DEC_Overflow ) return DEC_Condition_OV; | |
358 | if (status==DEC_Underflow ) return DEC_Condition_UN; | |
359 | if (status==DEC_Inexact ) return DEC_Condition_IE; | |
360 | ||
361 | if (status==DEC_Division_impossible ) return DEC_Condition_DI; | |
362 | if (status==DEC_Division_undefined ) return DEC_Condition_DU; | |
363 | if (status==DEC_Rounded ) return DEC_Condition_RO; | |
364 | if (status==DEC_Clamped ) return DEC_Condition_PA; | |
365 | if (status==DEC_Subnormal ) return DEC_Condition_SU; | |
366 | if (status==DEC_Conversion_syntax ) return DEC_Condition_CS; | |
367 | if (status==DEC_Insufficient_storage ) return DEC_Condition_IS; | |
368 | if (status==DEC_Invalid_context ) return DEC_Condition_IC; | |
369 | #if DECSUBSET | |
370 | if (status==DEC_Lost_digits ) return DEC_Condition_LD; | |
371 | #endif | |
87d32bb7 | 372 | if (status==0 ) return DEC_Condition_ZE; |
f5bc1778 DJ |
373 | return DEC_Condition_MU; /* Multiple errors */ |
374 | } /* decContextStatusToString */ | |
375 | ||
87d32bb7 DD |
376 | /* ------------------------------------------------------------------ */ |
377 | /* decContextTestEndian -- test whether DECLITEND is set correctly */ | |
378 | /* */ | |
379 | /* quiet is 1 to suppress message; 0 otherwise */ | |
380 | /* returns 0 if DECLITEND is correct */ | |
381 | /* 1 if DECLITEND is incorrect and should be 1 */ | |
382 | /* -1 if DECLITEND is incorrect and should be 0 */ | |
383 | /* */ | |
384 | /* A message is displayed if the return value is not 0 and quiet==0. */ | |
385 | /* */ | |
386 | /* No error is possible. */ | |
387 | /* ------------------------------------------------------------------ */ | |
388 | Int decContextTestEndian(Flag quiet) { | |
389 | Int res=0; /* optimist */ | |
390 | uInt dle=(uInt)DECLITEND; /* unsign */ | |
391 | if (dle>1) dle=1; /* ensure 0 or 1 */ | |
392 | ||
393 | if (LITEND!=DECLITEND) { | |
394 | const char *adj; | |
395 | if (!quiet) { | |
396 | if (LITEND) adj="little"; | |
397 | else adj="big"; | |
398 | printf("Warning: DECLITEND is set to %d, but this computer appears to be %s-endian\n", | |
399 | DECLITEND, adj); | |
400 | } | |
401 | res=(Int)LITEND-dle; | |
402 | } | |
403 | return res; | |
404 | } /* decContextTestEndian */ | |
405 | ||
f5bc1778 DJ |
406 | /* ------------------------------------------------------------------ */ |
407 | /* decContextTestSavedStatus -- test bits in saved status */ | |
408 | /* */ | |
409 | /* oldstatus is the status word to be tested */ | |
410 | /* mask indicates the bits to be tested (the oldstatus 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 | uInt decContextTestSavedStatus(uInt oldstatus, uInt mask) { | |
417 | return (oldstatus&mask)!=0; | |
418 | } /* decContextTestSavedStatus */ | |
419 | ||
420 | /* ------------------------------------------------------------------ */ | |
421 | /* decContextTestStatus -- test bits in current status */ | |
422 | /* */ | |
423 | /* context is the context structure to be updated */ | |
424 | /* mask indicates the bits to be tested (the status bits that */ | |
425 | /* correspond to each 1 bit in the mask are tested) */ | |
426 | /* returns 1 if any of the tested bits are 1, or 0 otherwise */ | |
427 | /* */ | |
428 | /* No error is possible. */ | |
429 | /* ------------------------------------------------------------------ */ | |
430 | uInt decContextTestStatus(decContext *context, uInt mask) { | |
431 | return (context->status&mask)!=0; | |
432 | } /* decContextTestStatus */ | |
433 | ||
434 | /* ------------------------------------------------------------------ */ | |
435 | /* decContextZeroStatus -- clear all status bits */ | |
436 | /* */ | |
437 | /* context is the context structure to be updated */ | |
438 | /* returns context */ | |
439 | /* */ | |
440 | /* No error is possible. */ | |
441 | /* ------------------------------------------------------------------ */ | |
442 | decContext *decContextZeroStatus(decContext *context) { | |
443 | context->status=0; | |
444 | return context; | |
445 | } /* decContextZeroStatus */ | |
446 |