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| 1 /* ------------------------------------------------------------------ */ |
| 2 /* Decimal Context module */ |
| 3 /* ------------------------------------------------------------------ */ |
| 4 /* Copyright (c) IBM Corporation, 2000-2010. All rights reserved. */ |
| 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 |
| 28 /* compile-time endian tester [assumes sizeof(Int)>1] */ |
| 29 static const Int mfcone=1; /* constant 1 */ |
| 30 static const Flag *mfctop=(Flag *)&mfcone; /* -> top byte */ |
| 31 #define LITEND *mfctop /* named flag; 1=little-endian */ |
| 32 |
| 33 /* ------------------------------------------------------------------ */ |
| 34 /* round-for-reround digits */ |
| 35 /* ------------------------------------------------------------------ */ |
| 36 const uByte DECSTICKYTAB[10]={1,1,2,3,4,6,6,7,8,9}; /* used if sticky */ |
| 37 |
| 38 /* ------------------------------------------------------------------ */ |
| 39 /* Powers of ten (powers[n]==10**n, 0<=n<=9) */ |
| 40 /* ------------------------------------------------------------------ */ |
| 41 const uInt DECPOWERS[10]={1, 10, 100, 1000, 10000, 100000, 1000000, |
| 42 10000000, 100000000, 1000000000}; |
| 43 |
| 44 /* ------------------------------------------------------------------ */ |
| 45 /* decContextClearStatus -- clear bits in current status */ |
| 46 /* */ |
| 47 /* context is the context structure to be queried */ |
| 48 /* mask indicates the bits to be cleared (the status bit that */ |
| 49 /* corresponds to each 1 bit in the mask is cleared) */ |
| 50 /* returns context */ |
| 51 /* */ |
| 52 /* No error is possible. */ |
| 53 /* ------------------------------------------------------------------ */ |
| 54 U_CAPI decContext * U_EXPORT2 uprv_decContextClearStatus(decContext *context, uI
nt mask) { |
| 55 context->status&=~mask; |
| 56 return context; |
| 57 } /* decContextClearStatus */ |
| 58 |
| 59 /* ------------------------------------------------------------------ */ |
| 60 /* decContextDefault -- initialize a context structure */ |
| 61 /* */ |
| 62 /* context is the structure to be initialized */ |
| 63 /* kind selects the required set of default values, one of: */ |
| 64 /* DEC_INIT_BASE -- select ANSI X3-274 defaults */ |
| 65 /* DEC_INIT_DECIMAL32 -- select IEEE 754 defaults, 32-bit */ |
| 66 /* DEC_INIT_DECIMAL64 -- select IEEE 754 defaults, 64-bit */ |
| 67 /* DEC_INIT_DECIMAL128 -- select IEEE 754 defaults, 128-bit */ |
| 68 /* For any other value a valid context is returned, but with */ |
| 69 /* Invalid_operation set in the status field. */ |
| 70 /* returns a context structure with the appropriate initial values. */ |
| 71 /* ------------------------------------------------------------------ */ |
| 72 U_CAPI decContext * U_EXPORT2 uprv_decContextDefault(decContext *context, Int k
ind) { |
| 73 /* set defaults... */ |
| 74 context->digits=9; /* 9 digits */ |
| 75 context->emax=DEC_MAX_EMAX; /* 9-digit exponents */ |
| 76 context->emin=DEC_MIN_EMIN; /* .. balanced */ |
| 77 context->round=DEC_ROUND_HALF_UP; /* 0.5 rises */ |
| 78 context->traps=DEC_Errors; /* all but informational */ |
| 79 context->status=0; /* cleared */ |
| 80 context->clamp=0; /* no clamping */ |
| 81 #if DECSUBSET |
| 82 context->extended=0; /* cleared */ |
| 83 #endif |
| 84 switch (kind) { |
| 85 case DEC_INIT_BASE: |
| 86 /* [use defaults] */ |
| 87 break; |
| 88 case DEC_INIT_DECIMAL32: |
| 89 context->digits=7; /* digits */ |
| 90 context->emax=96; /* Emax */ |
| 91 context->emin=-95; /* Emin */ |
| 92 context->round=DEC_ROUND_HALF_EVEN; /* 0.5 to nearest even */ |
| 93 context->traps=0; /* no traps set */ |
| 94 context->clamp=1; /* clamp exponents */ |
| 95 #if DECSUBSET |
| 96 context->extended=1; /* set */ |
| 97 #endif |
| 98 break; |
| 99 case DEC_INIT_DECIMAL64: |
| 100 context->digits=16; /* digits */ |
| 101 context->emax=384; /* Emax */ |
| 102 context->emin=-383; /* Emin */ |
| 103 context->round=DEC_ROUND_HALF_EVEN; /* 0.5 to nearest even */ |
| 104 context->traps=0; /* no traps set */ |
| 105 context->clamp=1; /* clamp exponents */ |
| 106 #if DECSUBSET |
| 107 context->extended=1; /* set */ |
| 108 #endif |
| 109 break; |
| 110 case DEC_INIT_DECIMAL128: |
| 111 context->digits=34; /* digits */ |
| 112 context->emax=6144; /* Emax */ |
| 113 context->emin=-6143; /* Emin */ |
| 114 context->round=DEC_ROUND_HALF_EVEN; /* 0.5 to nearest even */ |
| 115 context->traps=0; /* no traps set */ |
| 116 context->clamp=1; /* clamp exponents */ |
| 117 #if DECSUBSET |
| 118 context->extended=1; /* set */ |
| 119 #endif |
| 120 break; |
| 121 |
| 122 default: /* invalid Kind */ |
| 123 /* use defaults, and .. */ |
| 124 uprv_decContextSetStatus(context, DEC_Invalid_operation); /* trap */ |
| 125 } |
| 126 |
| 127 return context;} /* decContextDefault */ |
| 128 |
| 129 /* ------------------------------------------------------------------ */ |
| 130 /* decContextGetRounding -- return current rounding mode */ |
| 131 /* */ |
| 132 /* context is the context structure to be queried */ |
| 133 /* returns the rounding mode */ |
| 134 /* */ |
| 135 /* No error is possible. */ |
| 136 /* ------------------------------------------------------------------ */ |
| 137 U_CAPI enum rounding U_EXPORT2 uprv_decContextGetRounding(decContext *context)
{ |
| 138 return context->round; |
| 139 } /* decContextGetRounding */ |
| 140 |
| 141 /* ------------------------------------------------------------------ */ |
| 142 /* decContextGetStatus -- return current status */ |
| 143 /* */ |
| 144 /* context is the context structure to be queried */ |
| 145 /* returns status */ |
| 146 /* */ |
| 147 /* No error is possible. */ |
| 148 /* ------------------------------------------------------------------ */ |
| 149 U_CAPI uInt U_EXPORT2 uprv_decContextGetStatus(decContext *context) { |
| 150 return context->status; |
| 151 } /* decContextGetStatus */ |
| 152 |
| 153 /* ------------------------------------------------------------------ */ |
| 154 /* decContextRestoreStatus -- restore bits in current status */ |
| 155 /* */ |
| 156 /* context is the context structure to be updated */ |
| 157 /* newstatus is the source for the bits to be restored */ |
| 158 /* mask indicates the bits to be restored (the status bit that */ |
| 159 /* corresponds to each 1 bit in the mask is set to the value of */ |
| 160 /* the correspnding bit in newstatus) */ |
| 161 /* returns context */ |
| 162 /* */ |
| 163 /* No error is possible. */ |
| 164 /* ------------------------------------------------------------------ */ |
| 165 U_CAPI decContext * U_EXPORT2 uprv_decContextRestoreStatus(decContext *context, |
| 166 uInt newstatus, uInt mask) { |
| 167 context->status&=~mask; /* clear the selected bits */ |
| 168 context->status|=(mask&newstatus); /* or in the new bits */ |
| 169 return context; |
| 170 } /* decContextRestoreStatus */ |
| 171 |
| 172 /* ------------------------------------------------------------------ */ |
| 173 /* decContextSaveStatus -- save bits in current status */ |
| 174 /* */ |
| 175 /* context is the context structure to be queried */ |
| 176 /* mask indicates the bits to be saved (the status bits that */ |
| 177 /* correspond to each 1 bit in the mask are saved) */ |
| 178 /* returns the AND of the mask and the current status */ |
| 179 /* */ |
| 180 /* No error is possible. */ |
| 181 /* ------------------------------------------------------------------ */ |
| 182 U_CAPI uInt U_EXPORT2 uprv_decContextSaveStatus(decContext *context, uInt mask)
{ |
| 183 return context->status&mask; |
| 184 } /* decContextSaveStatus */ |
| 185 |
| 186 /* ------------------------------------------------------------------ */ |
| 187 /* decContextSetRounding -- set current rounding mode */ |
| 188 /* */ |
| 189 /* context is the context structure to be updated */ |
| 190 /* newround is the value which will replace the current mode */ |
| 191 /* returns context */ |
| 192 /* */ |
| 193 /* No error is possible. */ |
| 194 /* ------------------------------------------------------------------ */ |
| 195 U_CAPI decContext * U_EXPORT2 uprv_decContextSetRounding(decContext *context, |
| 196 enum rounding newround) { |
| 197 context->round=newround; |
| 198 return context; |
| 199 } /* decContextSetRounding */ |
| 200 |
| 201 /* ------------------------------------------------------------------ */ |
| 202 /* decContextSetStatus -- set status and raise trap if appropriate */ |
| 203 /* */ |
| 204 /* context is the context structure to be updated */ |
| 205 /* status is the DEC_ exception code */ |
| 206 /* returns the context structure */ |
| 207 /* */ |
| 208 /* Control may never return from this routine, if there is a signal */ |
| 209 /* handler and it takes a long jump. */ |
| 210 /* ------------------------------------------------------------------ */ |
| 211 U_CAPI decContext * U_EXPORT2 uprv_decContextSetStatus(decContext *context, uIn
t status) { |
| 212 context->status|=status; |
| 213 if (status & context->traps) raise(SIGFPE); |
| 214 return context;} /* decContextSetStatus */ |
| 215 |
| 216 /* ------------------------------------------------------------------ */ |
| 217 /* decContextSetStatusFromString -- set status from a string + trap */ |
| 218 /* */ |
| 219 /* context is the context structure to be updated */ |
| 220 /* string is a string exactly equal to one that might be returned */ |
| 221 /* by decContextStatusToString */ |
| 222 /* */ |
| 223 /* The status bit corresponding to the string is set, and a trap */ |
| 224 /* is raised if appropriate. */ |
| 225 /* */ |
| 226 /* returns the context structure, unless the string is equal to */ |
| 227 /* DEC_Condition_MU or is not recognized. In these cases NULL is */ |
| 228 /* returned. */ |
| 229 /* ------------------------------------------------------------------ */ |
| 230 U_CAPI decContext * U_EXPORT2 uprv_decContextSetStatusFromString(decContext *co
ntext, |
| 231 const char *string) { |
| 232 if (strcmp(string, DEC_Condition_CS)==0) |
| 233 return uprv_decContextSetStatus(context, DEC_Conversion_syntax); |
| 234 if (strcmp(string, DEC_Condition_DZ)==0) |
| 235 return uprv_decContextSetStatus(context, DEC_Division_by_zero); |
| 236 if (strcmp(string, DEC_Condition_DI)==0) |
| 237 return uprv_decContextSetStatus(context, DEC_Division_impossible); |
| 238 if (strcmp(string, DEC_Condition_DU)==0) |
| 239 return uprv_decContextSetStatus(context, DEC_Division_undefined); |
| 240 if (strcmp(string, DEC_Condition_IE)==0) |
| 241 return uprv_decContextSetStatus(context, DEC_Inexact); |
| 242 if (strcmp(string, DEC_Condition_IS)==0) |
| 243 return uprv_decContextSetStatus(context, DEC_Insufficient_storage); |
| 244 if (strcmp(string, DEC_Condition_IC)==0) |
| 245 return uprv_decContextSetStatus(context, DEC_Invalid_context); |
| 246 if (strcmp(string, DEC_Condition_IO)==0) |
| 247 return uprv_decContextSetStatus(context, DEC_Invalid_operation); |
| 248 #if DECSUBSET |
| 249 if (strcmp(string, DEC_Condition_LD)==0) |
| 250 return uprv_decContextSetStatus(context, DEC_Lost_digits); |
| 251 #endif |
| 252 if (strcmp(string, DEC_Condition_OV)==0) |
| 253 return uprv_decContextSetStatus(context, DEC_Overflow); |
| 254 if (strcmp(string, DEC_Condition_PA)==0) |
| 255 return uprv_decContextSetStatus(context, DEC_Clamped); |
| 256 if (strcmp(string, DEC_Condition_RO)==0) |
| 257 return uprv_decContextSetStatus(context, DEC_Rounded); |
| 258 if (strcmp(string, DEC_Condition_SU)==0) |
| 259 return uprv_decContextSetStatus(context, DEC_Subnormal); |
| 260 if (strcmp(string, DEC_Condition_UN)==0) |
| 261 return uprv_decContextSetStatus(context, DEC_Underflow); |
| 262 if (strcmp(string, DEC_Condition_ZE)==0) |
| 263 return context; |
| 264 return NULL; /* Multiple status, or unknown */ |
| 265 } /* decContextSetStatusFromString */ |
| 266 |
| 267 /* ------------------------------------------------------------------ */ |
| 268 /* decContextSetStatusFromStringQuiet -- set status from a string */ |
| 269 /* */ |
| 270 /* context is the context structure to be updated */ |
| 271 /* string is a string exactly equal to one that might be returned */ |
| 272 /* by decContextStatusToString */ |
| 273 /* */ |
| 274 /* The status bit corresponding to the string is set; no trap is */ |
| 275 /* raised. */ |
| 276 /* */ |
| 277 /* returns the context structure, unless the string is equal to */ |
| 278 /* DEC_Condition_MU or is not recognized. In these cases NULL is */ |
| 279 /* returned. */ |
| 280 /* ------------------------------------------------------------------ */ |
| 281 U_CAPI decContext * U_EXPORT2 uprv_decContextSetStatusFromStringQuiet(decContex
t *context, |
| 282 const char *string) { |
| 283 if (strcmp(string, DEC_Condition_CS)==0) |
| 284 return uprv_decContextSetStatusQuiet(context, DEC_Conversion_syntax); |
| 285 if (strcmp(string, DEC_Condition_DZ)==0) |
| 286 return uprv_decContextSetStatusQuiet(context, DEC_Division_by_zero); |
| 287 if (strcmp(string, DEC_Condition_DI)==0) |
| 288 return uprv_decContextSetStatusQuiet(context, DEC_Division_impossible); |
| 289 if (strcmp(string, DEC_Condition_DU)==0) |
| 290 return uprv_decContextSetStatusQuiet(context, DEC_Division_undefined); |
| 291 if (strcmp(string, DEC_Condition_IE)==0) |
| 292 return uprv_decContextSetStatusQuiet(context, DEC_Inexact); |
| 293 if (strcmp(string, DEC_Condition_IS)==0) |
| 294 return uprv_decContextSetStatusQuiet(context, DEC_Insufficient_storage); |
| 295 if (strcmp(string, DEC_Condition_IC)==0) |
| 296 return uprv_decContextSetStatusQuiet(context, DEC_Invalid_context); |
| 297 if (strcmp(string, DEC_Condition_IO)==0) |
| 298 return uprv_decContextSetStatusQuiet(context, DEC_Invalid_operation); |
| 299 #if DECSUBSET |
| 300 if (strcmp(string, DEC_Condition_LD)==0) |
| 301 return uprv_decContextSetStatusQuiet(context, DEC_Lost_digits); |
| 302 #endif |
| 303 if (strcmp(string, DEC_Condition_OV)==0) |
| 304 return uprv_decContextSetStatusQuiet(context, DEC_Overflow); |
| 305 if (strcmp(string, DEC_Condition_PA)==0) |
| 306 return uprv_decContextSetStatusQuiet(context, DEC_Clamped); |
| 307 if (strcmp(string, DEC_Condition_RO)==0) |
| 308 return uprv_decContextSetStatusQuiet(context, DEC_Rounded); |
| 309 if (strcmp(string, DEC_Condition_SU)==0) |
| 310 return uprv_decContextSetStatusQuiet(context, DEC_Subnormal); |
| 311 if (strcmp(string, DEC_Condition_UN)==0) |
| 312 return uprv_decContextSetStatusQuiet(context, DEC_Underflow); |
| 313 if (strcmp(string, DEC_Condition_ZE)==0) |
| 314 return context; |
| 315 return NULL; /* Multiple status, or unknown */ |
| 316 } /* decContextSetStatusFromStringQuiet */ |
| 317 |
| 318 /* ------------------------------------------------------------------ */ |
| 319 /* decContextSetStatusQuiet -- set status without trap */ |
| 320 /* */ |
| 321 /* context is the context structure to be updated */ |
| 322 /* status is the DEC_ exception code */ |
| 323 /* returns the context structure */ |
| 324 /* */ |
| 325 /* No error is possible. */ |
| 326 /* ------------------------------------------------------------------ */ |
| 327 U_CAPI decContext * U_EXPORT2 uprv_decContextSetStatusQuiet(decContext *context
, uInt status) { |
| 328 context->status|=status; |
| 329 return context;} /* decContextSetStatusQuiet */ |
| 330 |
| 331 /* ------------------------------------------------------------------ */ |
| 332 /* decContextStatusToString -- convert status flags to a string */ |
| 333 /* */ |
| 334 /* context is a context with valid status field */ |
| 335 /* */ |
| 336 /* returns a constant string describing the condition. If multiple */ |
| 337 /* (or no) flags are set, a generic constant message is returned. */ |
| 338 /* ------------------------------------------------------------------ */ |
| 339 U_CAPI const char * U_EXPORT2 uprv_decContextStatusToString(const decContext *co
ntext) { |
| 340 Int status=context->status; |
| 341 |
| 342 /* test the five IEEE first, as some of the others are ambiguous when */ |
| 343 /* DECEXTFLAG=0 */ |
| 344 if (status==DEC_Invalid_operation ) return DEC_Condition_IO; |
| 345 if (status==DEC_Division_by_zero ) return DEC_Condition_DZ; |
| 346 if (status==DEC_Overflow ) return DEC_Condition_OV; |
| 347 if (status==DEC_Underflow ) return DEC_Condition_UN; |
| 348 if (status==DEC_Inexact ) return DEC_Condition_IE; |
| 349 |
| 350 if (status==DEC_Division_impossible ) return DEC_Condition_DI; |
| 351 if (status==DEC_Division_undefined ) return DEC_Condition_DU; |
| 352 if (status==DEC_Rounded ) return DEC_Condition_RO; |
| 353 if (status==DEC_Clamped ) return DEC_Condition_PA; |
| 354 if (status==DEC_Subnormal ) return DEC_Condition_SU; |
| 355 if (status==DEC_Conversion_syntax ) return DEC_Condition_CS; |
| 356 if (status==DEC_Insufficient_storage ) return DEC_Condition_IS; |
| 357 if (status==DEC_Invalid_context ) return DEC_Condition_IC; |
| 358 #if DECSUBSET |
| 359 if (status==DEC_Lost_digits ) return DEC_Condition_LD; |
| 360 #endif |
| 361 if (status==0 ) return DEC_Condition_ZE; |
| 362 return DEC_Condition_MU; /* Multiple errors */ |
| 363 } /* decContextStatusToString */ |
| 364 |
| 365 /* ------------------------------------------------------------------ */ |
| 366 /* decContextTestEndian -- test whether DECLITEND is set correctly */ |
| 367 /* */ |
| 368 /* quiet is 1 to suppress message; 0 otherwise */ |
| 369 /* returns 0 if DECLITEND is correct */ |
| 370 /* 1 if DECLITEND is incorrect and should be 1 */ |
| 371 /* -1 if DECLITEND is incorrect and should be 0 */ |
| 372 /* */ |
| 373 /* A message is displayed if the return value is not 0 and quiet==0. */ |
| 374 /* */ |
| 375 /* No error is possible. */ |
| 376 /* ------------------------------------------------------------------ */ |
| 377 U_CAPI Int U_EXPORT2 uprv_decContextTestEndian(Flag quiet) { |
| 378 Int res=0; /* optimist */ |
| 379 uInt dle=(uInt)DECLITEND; /* unsign */ |
| 380 if (dle>1) dle=1; /* ensure 0 or 1 */ |
| 381 |
| 382 if (LITEND!=DECLITEND) { |
| 383 const char *adj; |
| 384 if (!quiet) { |
| 385 if (LITEND) adj="little"; |
| 386 else adj="big"; |
| 387 printf("Warning: DECLITEND is set to %d, but this computer appears to be %
s-endian\n", |
| 388 DECLITEND, adj); |
| 389 } |
| 390 res=(Int)LITEND-dle; |
| 391 } |
| 392 return res; |
| 393 } /* decContextTestEndian */ |
| 394 |
| 395 /* ------------------------------------------------------------------ */ |
| 396 /* decContextTestSavedStatus -- test bits in saved status */ |
| 397 /* */ |
| 398 /* oldstatus is the status word to be tested */ |
| 399 /* mask indicates the bits to be tested (the oldstatus bits that */ |
| 400 /* correspond to each 1 bit in the mask are tested) */ |
| 401 /* returns 1 if any of the tested bits are 1, or 0 otherwise */ |
| 402 /* */ |
| 403 /* No error is possible. */ |
| 404 /* ------------------------------------------------------------------ */ |
| 405 U_CAPI uInt U_EXPORT2 uprv_decContextTestSavedStatus(uInt oldstatus, uInt mask)
{ |
| 406 return (oldstatus&mask)!=0; |
| 407 } /* decContextTestSavedStatus */ |
| 408 |
| 409 /* ------------------------------------------------------------------ */ |
| 410 /* decContextTestStatus -- test bits in current status */ |
| 411 /* */ |
| 412 /* context is the context structure to be updated */ |
| 413 /* mask indicates the bits to be tested (the status bits that */ |
| 414 /* correspond to each 1 bit in the mask are tested) */ |
| 415 /* returns 1 if any of the tested bits are 1, or 0 otherwise */ |
| 416 /* */ |
| 417 /* No error is possible. */ |
| 418 /* ------------------------------------------------------------------ */ |
| 419 U_CAPI uInt U_EXPORT2 uprv_decContextTestStatus(decContext *context, uInt mask)
{ |
| 420 return (context->status&mask)!=0; |
| 421 } /* decContextTestStatus */ |
| 422 |
| 423 /* ------------------------------------------------------------------ */ |
| 424 /* decContextZeroStatus -- clear all status bits */ |
| 425 /* */ |
| 426 /* context is the context structure to be updated */ |
| 427 /* returns context */ |
| 428 /* */ |
| 429 /* No error is possible. */ |
| 430 /* ------------------------------------------------------------------ */ |
| 431 U_CAPI decContext * U_EXPORT2 uprv_decContextZeroStatus(decContext *context) { |
| 432 context->status=0; |
| 433 return context; |
| 434 } /* decContextZeroStatus */ |
| 435 |
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Chromium Code Reviews
Issue 5516007:
Check in the pristine copy of ICU 4.6... (Closed)
Base URL: svn://chrome-svn/chrome/trunk/deps/third_party/