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f5bc1778 DJ |
1 | /* Decimal context module for the decNumber C Library. |
2 | Copyright (C) 2005, 2007 Free Software Foundation, Inc. | |
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 | |
9 | Software Foundation; either version 2, or (at your option) any later | |
10 | version. | |
11 | ||
12 | In addition to the permissions in the GNU General Public License, | |
13 | the Free Software Foundation gives you unlimited permission to link | |
14 | the compiled version of this file into combinations with other | |
15 | programs, and to distribute those combinations without any | |
16 | restriction coming from the use of this file. (The General Public | |
17 | License restrictions do apply in other respects; for example, they | |
18 | cover modification of the file, and distribution when not linked | |
19 | into a combine executable.) | |
20 | ||
21 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
22 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
23 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
24 | for more details. | |
25 | ||
26 | You should have received a copy of the GNU General Public License | |
27 | along with GCC; see the file COPYING. If not, write to the Free | |
28 | Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA | |
29 | 02110-1301, USA. */ | |
30 | ||
31 | /* ------------------------------------------------------------------ */ | |
32 | /* Decimal Context module */ | |
33 | /* ------------------------------------------------------------------ */ | |
34 | /* This module comprises the routines for handling arithmetic */ | |
35 | /* context structures. */ | |
36 | /* ------------------------------------------------------------------ */ | |
37 | ||
38 | #include <string.h> /* for strcmp */ | |
39 | #include <stdio.h> /* for printf if DECCHECK */ | |
5f5dfcbe | 40 | #include "dconfig.h" /* for GCC definitions */ |
87d32bb7 | 41 | #include "decContext.h" /* context and base types */ |
f5bc1778 DJ |
42 | #include "decNumberLocal.h" /* decNumber local types, etc. */ |
43 | ||
f5bc1778 DJ |
44 | /* compile-time endian tester [assumes sizeof(Int)>1] */ |
45 | static const Int mfcone=1; /* constant 1 */ | |
87d32bb7 | 46 | static const Flag *mfctop=(const Flag *)&mfcone; /* -> top byte */ |
f5bc1778 | 47 | #define LITEND *mfctop /* named flag; 1=little-endian */ |
f5bc1778 DJ |
48 | |
49 | /* ------------------------------------------------------------------ */ | |
50 | /* round-for-reround digits */ | |
51 | /* ------------------------------------------------------------------ */ | |
52 | const uByte DECSTICKYTAB[10]={1,1,2,3,4,6,6,7,8,9}; /* used if sticky */ | |
53 | ||
54 | /* ------------------------------------------------------------------ */ | |
55 | /* Powers of ten (powers[n]==10**n, 0<=n<=9) */ | |
56 | /* ------------------------------------------------------------------ */ | |
57 | const uInt DECPOWERS[10]={1, 10, 100, 1000, 10000, 100000, 1000000, | |
58 | 10000000, 100000000, 1000000000}; | |
59 | ||
60 | /* ------------------------------------------------------------------ */ | |
61 | /* decContextClearStatus -- clear bits in current status */ | |
62 | /* */ | |
63 | /* context is the context structure to be queried */ | |
64 | /* mask indicates the bits to be cleared (the status bit that */ | |
87d32bb7 | 65 | /* corresponds to each 1 bit in the mask is cleared) */ |
f5bc1778 DJ |
66 | /* returns context */ |
67 | /* */ | |
68 | /* No error is possible. */ | |
69 | /* ------------------------------------------------------------------ */ | |
70 | decContext *decContextClearStatus(decContext *context, uInt mask) { | |
71 | context->status&=~mask; | |
72 | return context; | |
73 | } /* decContextClearStatus */ | |
74 | ||
75 | /* ------------------------------------------------------------------ */ | |
76 | /* decContextDefault -- initialize a context structure */ | |
77 | /* */ | |
78 | /* context is the structure to be initialized */ | |
79 | /* kind selects the required set of default values, one of: */ | |
80 | /* DEC_INIT_BASE -- select ANSI X3-274 defaults */ | |
87d32bb7 DD |
81 | /* DEC_INIT_DECIMAL32 -- select IEEE 754 defaults, 32-bit */ |
82 | /* DEC_INIT_DECIMAL64 -- select IEEE 754 defaults, 64-bit */ | |
83 | /* DEC_INIT_DECIMAL128 -- select IEEE 754 defaults, 128-bit */ | |
f5bc1778 DJ |
84 | /* For any other value a valid context is returned, but with */ |
85 | /* Invalid_operation set in the status field. */ | |
86 | /* returns a context structure with the appropriate initial values. */ | |
87 | /* ------------------------------------------------------------------ */ | |
88 | decContext * decContextDefault(decContext *context, Int kind) { | |
89 | /* set defaults... */ | |
90 | context->digits=9; /* 9 digits */ | |
91 | context->emax=DEC_MAX_EMAX; /* 9-digit exponents */ | |
92 | context->emin=DEC_MIN_EMIN; /* .. balanced */ | |
93 | context->round=DEC_ROUND_HALF_UP; /* 0.5 rises */ | |
94 | context->traps=DEC_Errors; /* all but informational */ | |
95 | context->status=0; /* cleared */ | |
96 | context->clamp=0; /* no clamping */ | |
97 | #if DECSUBSET | |
98 | context->extended=0; /* cleared */ | |
99 | #endif | |
100 | switch (kind) { | |
101 | case DEC_INIT_BASE: | |
102 | /* [use defaults] */ | |
103 | break; | |
104 | case DEC_INIT_DECIMAL32: | |
105 | context->digits=7; /* digits */ | |
87d32bb7 | 106 | context->emax=96; /* Emax */ |
f5bc1778 DJ |
107 | context->emin=-95; /* Emin */ |
108 | context->round=DEC_ROUND_HALF_EVEN; /* 0.5 to nearest even */ | |
87d32bb7 DD |
109 | context->traps=0; /* no traps set */ |
110 | context->clamp=1; /* clamp exponents */ | |
f5bc1778 DJ |
111 | #if DECSUBSET |
112 | context->extended=1; /* set */ | |
113 | #endif | |
114 | break; | |
115 | case DEC_INIT_DECIMAL64: | |
116 | context->digits=16; /* digits */ | |
117 | context->emax=384; /* Emax */ | |
118 | context->emin=-383; /* Emin */ | |
119 | context->round=DEC_ROUND_HALF_EVEN; /* 0.5 to nearest even */ | |
87d32bb7 DD |
120 | context->traps=0; /* no traps set */ |
121 | context->clamp=1; /* clamp exponents */ | |
f5bc1778 DJ |
122 | #if DECSUBSET |
123 | context->extended=1; /* set */ | |
124 | #endif | |
125 | break; | |
126 | case DEC_INIT_DECIMAL128: | |
127 | context->digits=34; /* digits */ | |
128 | context->emax=6144; /* Emax */ | |
129 | context->emin=-6143; /* Emin */ | |
130 | context->round=DEC_ROUND_HALF_EVEN; /* 0.5 to nearest even */ | |
87d32bb7 DD |
131 | context->traps=0; /* no traps set */ |
132 | context->clamp=1; /* clamp exponents */ | |
f5bc1778 DJ |
133 | #if DECSUBSET |
134 | context->extended=1; /* set */ | |
135 | #endif | |
136 | break; | |
137 | ||
138 | default: /* invalid Kind */ | |
139 | /* use defaults, and .. */ | |
140 | decContextSetStatus(context, DEC_Invalid_operation); /* trap */ | |
141 | } | |
142 | ||
f5bc1778 DJ |
143 | return context;} /* decContextDefault */ |
144 | ||
145 | /* ------------------------------------------------------------------ */ | |
146 | /* decContextGetRounding -- return current rounding mode */ | |
147 | /* */ | |
148 | /* context is the context structure to be queried */ | |
149 | /* returns the rounding mode */ | |
150 | /* */ | |
151 | /* No error is possible. */ | |
152 | /* ------------------------------------------------------------------ */ | |
153 | enum rounding decContextGetRounding(decContext *context) { | |
154 | return context->round; | |
155 | } /* decContextGetRounding */ | |
156 | ||
157 | /* ------------------------------------------------------------------ */ | |
87d32bb7 | 158 | /* decContextGetStatus -- return current status */ |
f5bc1778 DJ |
159 | /* */ |
160 | /* context is the context structure to be queried */ | |
161 | /* returns status */ | |
162 | /* */ | |
163 | /* No error is possible. */ | |
164 | /* ------------------------------------------------------------------ */ | |
165 | uInt decContextGetStatus(decContext *context) { | |
166 | return context->status; | |
167 | } /* decContextGetStatus */ | |
168 | ||
169 | /* ------------------------------------------------------------------ */ | |
170 | /* decContextRestoreStatus -- restore bits in current status */ | |
171 | /* */ | |
172 | /* context is the context structure to be updated */ | |
87d32bb7 DD |
173 | /* newstatus is the source for the bits to be restored */ |
174 | /* mask indicates the bits to be restored (the status bit that */ | |
f5bc1778 DJ |
175 | /* corresponds to each 1 bit in the mask is set to the value of */ |
176 | /* the correspnding bit in newstatus) */ | |
177 | /* returns context */ | |
178 | /* */ | |
179 | /* No error is possible. */ | |
180 | /* ------------------------------------------------------------------ */ | |
181 | decContext *decContextRestoreStatus(decContext *context, | |
182 | uInt newstatus, uInt mask) { | |
183 | context->status&=~mask; /* clear the selected bits */ | |
184 | context->status|=(mask&newstatus); /* or in the new bits */ | |
185 | return context; | |
186 | } /* decContextRestoreStatus */ | |
187 | ||
188 | /* ------------------------------------------------------------------ */ | |
189 | /* decContextSaveStatus -- save bits in current status */ | |
190 | /* */ | |
191 | /* context is the context structure to be queried */ | |
192 | /* mask indicates the bits to be saved (the status bits that */ | |
193 | /* correspond to each 1 bit in the mask are saved) */ | |
194 | /* returns the AND of the mask and the current status */ | |
195 | /* */ | |
196 | /* No error is possible. */ | |
197 | /* ------------------------------------------------------------------ */ | |
198 | uInt decContextSaveStatus(decContext *context, uInt mask) { | |
199 | return context->status&mask; | |
200 | } /* decContextSaveStatus */ | |
201 | ||
202 | /* ------------------------------------------------------------------ */ | |
203 | /* decContextSetRounding -- set current rounding mode */ | |
204 | /* */ | |
205 | /* context is the context structure to be updated */ | |
206 | /* newround is the value which will replace the current mode */ | |
207 | /* returns context */ | |
208 | /* */ | |
209 | /* No error is possible. */ | |
210 | /* ------------------------------------------------------------------ */ | |
211 | decContext *decContextSetRounding(decContext *context, | |
212 | enum rounding newround) { | |
213 | context->round=newround; | |
214 | return context; | |
215 | } /* decContextSetRounding */ | |
216 | ||
217 | /* ------------------------------------------------------------------ */ | |
218 | /* decContextSetStatus -- set status and raise trap if appropriate */ | |
219 | /* */ | |
220 | /* context is the context structure to be updated */ | |
221 | /* status is the DEC_ exception code */ | |
222 | /* returns the context structure */ | |
223 | /* */ | |
224 | /* Control may never return from this routine, if there is a signal */ | |
225 | /* handler and it takes a long jump. */ | |
226 | /* ------------------------------------------------------------------ */ | |
227 | decContext * decContextSetStatus(decContext *context, uInt status) { | |
228 | context->status|=status; | |
229 | if (status & context->traps) raise(SIGFPE); | |
230 | return context;} /* decContextSetStatus */ | |
231 | ||
232 | /* ------------------------------------------------------------------ */ | |
233 | /* decContextSetStatusFromString -- set status from a string + trap */ | |
234 | /* */ | |
235 | /* context is the context structure to be updated */ | |
236 | /* string is a string exactly equal to one that might be returned */ | |
237 | /* by decContextStatusToString */ | |
238 | /* */ | |
239 | /* The status bit corresponding to the string is set, and a trap */ | |
240 | /* is raised if appropriate. */ | |
241 | /* */ | |
242 | /* returns the context structure, unless the string is equal to */ | |
243 | /* DEC_Condition_MU or is not recognized. In these cases NULL is */ | |
87d32bb7 | 244 | /* returned. */ |
f5bc1778 DJ |
245 | /* ------------------------------------------------------------------ */ |
246 | decContext * decContextSetStatusFromString(decContext *context, | |
247 | const char *string) { | |
248 | if (strcmp(string, DEC_Condition_CS)==0) | |
249 | return decContextSetStatus(context, DEC_Conversion_syntax); | |
250 | if (strcmp(string, DEC_Condition_DZ)==0) | |
251 | return decContextSetStatus(context, DEC_Division_by_zero); | |
252 | if (strcmp(string, DEC_Condition_DI)==0) | |
253 | return decContextSetStatus(context, DEC_Division_impossible); | |
254 | if (strcmp(string, DEC_Condition_DU)==0) | |
255 | return decContextSetStatus(context, DEC_Division_undefined); | |
256 | if (strcmp(string, DEC_Condition_IE)==0) | |
257 | return decContextSetStatus(context, DEC_Inexact); | |
258 | if (strcmp(string, DEC_Condition_IS)==0) | |
259 | return decContextSetStatus(context, DEC_Insufficient_storage); | |
260 | if (strcmp(string, DEC_Condition_IC)==0) | |
261 | return decContextSetStatus(context, DEC_Invalid_context); | |
262 | if (strcmp(string, DEC_Condition_IO)==0) | |
263 | return decContextSetStatus(context, DEC_Invalid_operation); | |
264 | #if DECSUBSET | |
265 | if (strcmp(string, DEC_Condition_LD)==0) | |
266 | return decContextSetStatus(context, DEC_Lost_digits); | |
267 | #endif | |
268 | if (strcmp(string, DEC_Condition_OV)==0) | |
269 | return decContextSetStatus(context, DEC_Overflow); | |
270 | if (strcmp(string, DEC_Condition_PA)==0) | |
271 | return decContextSetStatus(context, DEC_Clamped); | |
272 | if (strcmp(string, DEC_Condition_RO)==0) | |
273 | return decContextSetStatus(context, DEC_Rounded); | |
274 | if (strcmp(string, DEC_Condition_SU)==0) | |
275 | return decContextSetStatus(context, DEC_Subnormal); | |
276 | if (strcmp(string, DEC_Condition_UN)==0) | |
277 | return decContextSetStatus(context, DEC_Underflow); | |
278 | if (strcmp(string, DEC_Condition_ZE)==0) | |
279 | return context; | |
280 | return NULL; /* Multiple status, or unknown */ | |
281 | } /* decContextSetStatusFromString */ | |
282 | ||
283 | /* ------------------------------------------------------------------ */ | |
284 | /* decContextSetStatusFromStringQuiet -- set status from a string */ | |
285 | /* */ | |
286 | /* context is the context structure to be updated */ | |
287 | /* string is a string exactly equal to one that might be returned */ | |
288 | /* by decContextStatusToString */ | |
289 | /* */ | |
290 | /* The status bit corresponding to the string is set; no trap is */ | |
291 | /* raised. */ | |
292 | /* */ | |
293 | /* returns the context structure, unless the string is equal to */ | |
294 | /* DEC_Condition_MU or is not recognized. In these cases NULL is */ | |
87d32bb7 | 295 | /* returned. */ |
f5bc1778 DJ |
296 | /* ------------------------------------------------------------------ */ |
297 | decContext * decContextSetStatusFromStringQuiet(decContext *context, | |
298 | const char *string) { | |
299 | if (strcmp(string, DEC_Condition_CS)==0) | |
300 | return decContextSetStatusQuiet(context, DEC_Conversion_syntax); | |
301 | if (strcmp(string, DEC_Condition_DZ)==0) | |
302 | return decContextSetStatusQuiet(context, DEC_Division_by_zero); | |
303 | if (strcmp(string, DEC_Condition_DI)==0) | |
304 | return decContextSetStatusQuiet(context, DEC_Division_impossible); | |
305 | if (strcmp(string, DEC_Condition_DU)==0) | |
306 | return decContextSetStatusQuiet(context, DEC_Division_undefined); | |
307 | if (strcmp(string, DEC_Condition_IE)==0) | |
308 | return decContextSetStatusQuiet(context, DEC_Inexact); | |
309 | if (strcmp(string, DEC_Condition_IS)==0) | |
310 | return decContextSetStatusQuiet(context, DEC_Insufficient_storage); | |
311 | if (strcmp(string, DEC_Condition_IC)==0) | |
312 | return decContextSetStatusQuiet(context, DEC_Invalid_context); | |
313 | if (strcmp(string, DEC_Condition_IO)==0) | |
314 | return decContextSetStatusQuiet(context, DEC_Invalid_operation); | |
315 | #if DECSUBSET | |
316 | if (strcmp(string, DEC_Condition_LD)==0) | |
317 | return decContextSetStatusQuiet(context, DEC_Lost_digits); | |
318 | #endif | |
319 | if (strcmp(string, DEC_Condition_OV)==0) | |
320 | return decContextSetStatusQuiet(context, DEC_Overflow); | |
321 | if (strcmp(string, DEC_Condition_PA)==0) | |
322 | return decContextSetStatusQuiet(context, DEC_Clamped); | |
323 | if (strcmp(string, DEC_Condition_RO)==0) | |
324 | return decContextSetStatusQuiet(context, DEC_Rounded); | |
325 | if (strcmp(string, DEC_Condition_SU)==0) | |
326 | return decContextSetStatusQuiet(context, DEC_Subnormal); | |
327 | if (strcmp(string, DEC_Condition_UN)==0) | |
328 | return decContextSetStatusQuiet(context, DEC_Underflow); | |
329 | if (strcmp(string, DEC_Condition_ZE)==0) | |
330 | return context; | |
331 | return NULL; /* Multiple status, or unknown */ | |
332 | } /* decContextSetStatusFromStringQuiet */ | |
333 | ||
334 | /* ------------------------------------------------------------------ */ | |
335 | /* decContextSetStatusQuiet -- set status without trap */ | |
336 | /* */ | |
337 | /* context is the context structure to be updated */ | |
338 | /* status is the DEC_ exception code */ | |
339 | /* returns the context structure */ | |
340 | /* */ | |
341 | /* No error is possible. */ | |
342 | /* ------------------------------------------------------------------ */ | |
343 | decContext * decContextSetStatusQuiet(decContext *context, uInt status) { | |
344 | context->status|=status; | |
345 | return context;} /* decContextSetStatusQuiet */ | |
346 | ||
347 | /* ------------------------------------------------------------------ */ | |
87d32bb7 | 348 | /* decContextStatusToString -- convert status flags to a string */ |
f5bc1778 DJ |
349 | /* */ |
350 | /* context is a context with valid status field */ | |
351 | /* */ | |
87d32bb7 | 352 | /* returns a constant string describing the condition. If multiple */ |
f5bc1778 DJ |
353 | /* (or no) flags are set, a generic constant message is returned. */ |
354 | /* ------------------------------------------------------------------ */ | |
355 | const char *decContextStatusToString(const decContext *context) { | |
356 | Int status=context->status; | |
357 | ||
358 | /* test the five IEEE first, as some of the others are ambiguous when */ | |
359 | /* DECEXTFLAG=0 */ | |
360 | if (status==DEC_Invalid_operation ) return DEC_Condition_IO; | |
361 | if (status==DEC_Division_by_zero ) return DEC_Condition_DZ; | |
362 | if (status==DEC_Overflow ) return DEC_Condition_OV; | |
363 | if (status==DEC_Underflow ) return DEC_Condition_UN; | |
364 | if (status==DEC_Inexact ) return DEC_Condition_IE; | |
365 | ||
366 | if (status==DEC_Division_impossible ) return DEC_Condition_DI; | |
367 | if (status==DEC_Division_undefined ) return DEC_Condition_DU; | |
368 | if (status==DEC_Rounded ) return DEC_Condition_RO; | |
369 | if (status==DEC_Clamped ) return DEC_Condition_PA; | |
370 | if (status==DEC_Subnormal ) return DEC_Condition_SU; | |
371 | if (status==DEC_Conversion_syntax ) return DEC_Condition_CS; | |
372 | if (status==DEC_Insufficient_storage ) return DEC_Condition_IS; | |
373 | if (status==DEC_Invalid_context ) return DEC_Condition_IC; | |
374 | #if DECSUBSET | |
375 | if (status==DEC_Lost_digits ) return DEC_Condition_LD; | |
376 | #endif | |
87d32bb7 | 377 | if (status==0 ) return DEC_Condition_ZE; |
f5bc1778 DJ |
378 | return DEC_Condition_MU; /* Multiple errors */ |
379 | } /* decContextStatusToString */ | |
380 | ||
87d32bb7 DD |
381 | /* ------------------------------------------------------------------ */ |
382 | /* decContextTestEndian -- test whether DECLITEND is set correctly */ | |
383 | /* */ | |
384 | /* quiet is 1 to suppress message; 0 otherwise */ | |
385 | /* returns 0 if DECLITEND is correct */ | |
386 | /* 1 if DECLITEND is incorrect and should be 1 */ | |
387 | /* -1 if DECLITEND is incorrect and should be 0 */ | |
388 | /* */ | |
389 | /* A message is displayed if the return value is not 0 and quiet==0. */ | |
390 | /* */ | |
391 | /* No error is possible. */ | |
392 | /* ------------------------------------------------------------------ */ | |
393 | Int decContextTestEndian(Flag quiet) { | |
394 | Int res=0; /* optimist */ | |
395 | uInt dle=(uInt)DECLITEND; /* unsign */ | |
396 | if (dle>1) dle=1; /* ensure 0 or 1 */ | |
397 | ||
398 | if (LITEND!=DECLITEND) { | |
399 | const char *adj; | |
400 | if (!quiet) { | |
401 | if (LITEND) adj="little"; | |
402 | else adj="big"; | |
403 | printf("Warning: DECLITEND is set to %d, but this computer appears to be %s-endian\n", | |
404 | DECLITEND, adj); | |
405 | } | |
406 | res=(Int)LITEND-dle; | |
407 | } | |
408 | return res; | |
409 | } /* decContextTestEndian */ | |
410 | ||
f5bc1778 DJ |
411 | /* ------------------------------------------------------------------ */ |
412 | /* decContextTestSavedStatus -- test bits in saved status */ | |
413 | /* */ | |
414 | /* oldstatus is the status word to be tested */ | |
415 | /* mask indicates the bits to be tested (the oldstatus bits that */ | |
416 | /* correspond to each 1 bit in the mask are tested) */ | |
417 | /* returns 1 if any of the tested bits are 1, or 0 otherwise */ | |
418 | /* */ | |
419 | /* No error is possible. */ | |
420 | /* ------------------------------------------------------------------ */ | |
421 | uInt decContextTestSavedStatus(uInt oldstatus, uInt mask) { | |
422 | return (oldstatus&mask)!=0; | |
423 | } /* decContextTestSavedStatus */ | |
424 | ||
425 | /* ------------------------------------------------------------------ */ | |
426 | /* decContextTestStatus -- test bits in current status */ | |
427 | /* */ | |
428 | /* context is the context structure to be updated */ | |
429 | /* mask indicates the bits to be tested (the status bits that */ | |
430 | /* correspond to each 1 bit in the mask are tested) */ | |
431 | /* returns 1 if any of the tested bits are 1, or 0 otherwise */ | |
432 | /* */ | |
433 | /* No error is possible. */ | |
434 | /* ------------------------------------------------------------------ */ | |
435 | uInt decContextTestStatus(decContext *context, uInt mask) { | |
436 | return (context->status&mask)!=0; | |
437 | } /* decContextTestStatus */ | |
438 | ||
439 | /* ------------------------------------------------------------------ */ | |
440 | /* decContextZeroStatus -- clear all status bits */ | |
441 | /* */ | |
442 | /* context is the context structure to be updated */ | |
443 | /* returns context */ | |
444 | /* */ | |
445 | /* No error is possible. */ | |
446 | /* ------------------------------------------------------------------ */ | |
447 | decContext *decContextZeroStatus(decContext *context) { | |
448 | context->status=0; | |
449 | return context; | |
450 | } /* decContextZeroStatus */ | |
451 |