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| 72ac97cd TM |
1 | /* Decimal 128-bit format 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 128-bit format module */ | |
| 33 | /* ------------------------------------------------------------------ */ | |
| 34 | /* This module comprises the routines for decimal128 format numbers. */ | |
| 35 | /* Conversions are supplied to and from decNumber and String. */ | |
| 36 | /* */ | |
| 37 | /* This is used when decNumber provides operations, either for all */ | |
| 38 | /* operations or as a proxy between decNumber and decSingle. */ | |
| 39 | /* */ | |
| 40 | /* Error handling is the same as decNumber (qv.). */ | |
| 41 | /* ------------------------------------------------------------------ */ | |
| 7a4e543d | 42 | #include "qemu/osdep.h" |
| 72ac97cd | 43 | |
| 0f2d3732 | 44 | #include "libdecnumber/dconfig.h" |
| 72ac97cd | 45 | #define DECNUMDIGITS 34 /* make decNumbers with space for 34 */ |
| 0f2d3732 TM |
46 | #include "libdecnumber/decNumber.h" |
| 47 | #include "libdecnumber/decNumberLocal.h" | |
| 48 | #include "libdecnumber/dpd/decimal128.h" | |
| 72ac97cd TM |
49 | |
| 50 | /* Utility routines and tables [in decimal64.c] */ | |
| 51 | extern const uInt COMBEXP[32], COMBMSD[32]; | |
| 72ac97cd TM |
52 | extern const uByte BIN2CHAR[4001]; |
| 53 | ||
| 54 | extern void decDigitsFromDPD(decNumber *, const uInt *, Int); | |
| 55 | extern void decDigitsToDPD(const decNumber *, uInt *, Int); | |
| 56 | ||
| 57 | #if DECTRACE || DECCHECK | |
| 58 | void decimal128Show(const decimal128 *); /* for debug */ | |
| 59 | extern void decNumberShow(const decNumber *); /* .. */ | |
| 60 | #endif | |
| 61 | ||
| 62 | /* Useful macro */ | |
| 63 | /* Clear a structure (e.g., a decNumber) */ | |
| 64 | #define DEC_clear(d) memset(d, 0, sizeof(*d)) | |
| 65 | ||
| 66 | /* ------------------------------------------------------------------ */ | |
| 67 | /* decimal128FromNumber -- convert decNumber to decimal128 */ | |
| 68 | /* */ | |
| 69 | /* ds is the target decimal128 */ | |
| 70 | /* dn is the source number (assumed valid) */ | |
| 71 | /* set is the context, used only for reporting errors */ | |
| 72 | /* */ | |
| 73 | /* The set argument is used only for status reporting and for the */ | |
| 74 | /* rounding mode (used if the coefficient is more than DECIMAL128_Pmax*/ | |
| 75 | /* digits or an overflow is detected). If the exponent is out of the */ | |
| 76 | /* valid range then Overflow or Underflow will be raised. */ | |
| 77 | /* After Underflow a subnormal result is possible. */ | |
| 78 | /* */ | |
| 79 | /* DEC_Clamped is set if the number has to be 'folded down' to fit, */ | |
| 80 | /* by reducing its exponent and multiplying the coefficient by a */ | |
| 81 | /* power of ten, or if the exponent on a zero had to be clamped. */ | |
| 82 | /* ------------------------------------------------------------------ */ | |
| 83 | decimal128 * decimal128FromNumber(decimal128 *d128, const decNumber *dn, | |
| 84 | decContext *set) { | |
| 85 | uInt status=0; /* status accumulator */ | |
| 86 | Int ae; /* adjusted exponent */ | |
| 87 | decNumber dw; /* work */ | |
| 88 | decContext dc; /* .. */ | |
| 89 | uInt *pu; /* .. */ | |
| 90 | uInt comb, exp; /* .. */ | |
| 91 | uInt targar[4]={0,0,0,0}; /* target 128-bit */ | |
| 92 | #define targhi targar[3] /* name the word with the sign */ | |
| 93 | #define targmh targar[2] /* name the words */ | |
| 94 | #define targml targar[1] /* .. */ | |
| 95 | #define targlo targar[0] /* .. */ | |
| 96 | ||
| 97 | /* If the number has too many digits, or the exponent could be */ | |
| 98 | /* out of range then reduce the number under the appropriate */ | |
| 99 | /* constraints. This could push the number to Infinity or zero, */ | |
| 100 | /* so this check and rounding must be done before generating the */ | |
| 101 | /* decimal128] */ | |
| 102 | ae=dn->exponent+dn->digits-1; /* [0 if special] */ | |
| 103 | if (dn->digits>DECIMAL128_Pmax /* too many digits */ | |
| 104 | || ae>DECIMAL128_Emax /* likely overflow */ | |
| 105 | || ae<DECIMAL128_Emin) { /* likely underflow */ | |
| 106 | decContextDefault(&dc, DEC_INIT_DECIMAL128); /* [no traps] */ | |
| 107 | dc.round=set->round; /* use supplied rounding */ | |
| 108 | decNumberPlus(&dw, dn, &dc); /* (round and check) */ | |
| 109 | /* [this changes -0 to 0, so enforce the sign...] */ | |
| 110 | dw.bits|=dn->bits&DECNEG; | |
| 111 | status=dc.status; /* save status */ | |
| 112 | dn=&dw; /* use the work number */ | |
| 113 | } /* maybe out of range */ | |
| 114 | ||
| 115 | if (dn->bits&DECSPECIAL) { /* a special value */ | |
| 116 | if (dn->bits&DECINF) targhi=DECIMAL_Inf<<24; | |
| 117 | else { /* sNaN or qNaN */ | |
| 118 | if ((*dn->lsu!=0 || dn->digits>1) /* non-zero coefficient */ | |
| 119 | && (dn->digits<DECIMAL128_Pmax)) { /* coefficient fits */ | |
| 120 | decDigitsToDPD(dn, targar, 0); | |
| 121 | } | |
| 122 | if (dn->bits&DECNAN) targhi|=DECIMAL_NaN<<24; | |
| 123 | else targhi|=DECIMAL_sNaN<<24; | |
| 124 | } /* a NaN */ | |
| 125 | } /* special */ | |
| 126 | ||
| 127 | else { /* is finite */ | |
| 128 | if (decNumberIsZero(dn)) { /* is a zero */ | |
| 129 | /* set and clamp exponent */ | |
| 130 | if (dn->exponent<-DECIMAL128_Bias) { | |
| 131 | exp=0; /* low clamp */ | |
| 132 | status|=DEC_Clamped; | |
| 133 | } | |
| 134 | else { | |
| 135 | exp=dn->exponent+DECIMAL128_Bias; /* bias exponent */ | |
| 136 | if (exp>DECIMAL128_Ehigh) { /* top clamp */ | |
| 137 | exp=DECIMAL128_Ehigh; | |
| 138 | status|=DEC_Clamped; | |
| 139 | } | |
| 140 | } | |
| 141 | comb=(exp>>9) & 0x18; /* msd=0, exp top 2 bits .. */ | |
| 142 | } | |
| 143 | else { /* non-zero finite number */ | |
| 144 | uInt msd; /* work */ | |
| 145 | Int pad=0; /* coefficient pad digits */ | |
| 146 | ||
| 147 | /* the dn is known to fit, but it may need to be padded */ | |
| 148 | exp=(uInt)(dn->exponent+DECIMAL128_Bias); /* bias exponent */ | |
| 149 | if (exp>DECIMAL128_Ehigh) { /* fold-down case */ | |
| 150 | pad=exp-DECIMAL128_Ehigh; | |
| 151 | exp=DECIMAL128_Ehigh; /* [to maximum] */ | |
| 152 | status|=DEC_Clamped; | |
| 153 | } | |
| 154 | ||
| 155 | /* [fastpath for common case is not a win, here] */ | |
| 156 | decDigitsToDPD(dn, targar, pad); | |
| 157 | /* save and clear the top digit */ | |
| 158 | msd=targhi>>14; | |
| 159 | targhi&=0x00003fff; | |
| 160 | ||
| 161 | /* create the combination field */ | |
| 162 | if (msd>=8) comb=0x18 | ((exp>>11) & 0x06) | (msd & 0x01); | |
| 163 | else comb=((exp>>9) & 0x18) | msd; | |
| 164 | } | |
| 165 | targhi|=comb<<26; /* add combination field .. */ | |
| 166 | targhi|=(exp&0xfff)<<14; /* .. and exponent continuation */ | |
| 167 | } /* finite */ | |
| 168 | ||
| 169 | if (dn->bits&DECNEG) targhi|=0x80000000; /* add sign bit */ | |
| 170 | ||
| 171 | /* now write to storage; this is endian */ | |
| 172 | pu=(uInt *)d128->bytes; /* overlay */ | |
| 173 | if (DECLITEND) { | |
| 174 | pu[0]=targlo; /* directly store the low int */ | |
| 175 | pu[1]=targml; /* then the mid-low */ | |
| 176 | pu[2]=targmh; /* then the mid-high */ | |
| 177 | pu[3]=targhi; /* then the high int */ | |
| 178 | } | |
| 179 | else { | |
| 180 | pu[0]=targhi; /* directly store the high int */ | |
| 181 | pu[1]=targmh; /* then the mid-high */ | |
| 182 | pu[2]=targml; /* then the mid-low */ | |
| 183 | pu[3]=targlo; /* then the low int */ | |
| 184 | } | |
| 185 | ||
| 186 | if (status!=0) decContextSetStatus(set, status); /* pass on status */ | |
| 187 | /* decimal128Show(d128); */ | |
| 188 | return d128; | |
| 189 | } /* decimal128FromNumber */ | |
| 190 | ||
| 191 | /* ------------------------------------------------------------------ */ | |
| 192 | /* decimal128ToNumber -- convert decimal128 to decNumber */ | |
| 193 | /* d128 is the source decimal128 */ | |
| 194 | /* dn is the target number, with appropriate space */ | |
| 195 | /* No error is possible. */ | |
| 196 | /* ------------------------------------------------------------------ */ | |
| 197 | decNumber * decimal128ToNumber(const decimal128 *d128, decNumber *dn) { | |
| 198 | uInt msd; /* coefficient MSD */ | |
| 199 | uInt exp; /* exponent top two bits */ | |
| 200 | uInt comb; /* combination field */ | |
| 201 | const uInt *pu; /* work */ | |
| 202 | Int need; /* .. */ | |
| 203 | uInt sourar[4]; /* source 128-bit */ | |
| 204 | #define sourhi sourar[3] /* name the word with the sign */ | |
| 205 | #define sourmh sourar[2] /* and the mid-high word */ | |
| 206 | #define sourml sourar[1] /* and the mod-low word */ | |
| 207 | #define sourlo sourar[0] /* and the lowest word */ | |
| 208 | ||
| 209 | /* load source from storage; this is endian */ | |
| 210 | pu=(const uInt *)d128->bytes; /* overlay */ | |
| 211 | if (DECLITEND) { | |
| 212 | sourlo=pu[0]; /* directly load the low int */ | |
| 213 | sourml=pu[1]; /* then the mid-low */ | |
| 214 | sourmh=pu[2]; /* then the mid-high */ | |
| 215 | sourhi=pu[3]; /* then the high int */ | |
| 216 | } | |
| 217 | else { | |
| 218 | sourhi=pu[0]; /* directly load the high int */ | |
| 219 | sourmh=pu[1]; /* then the mid-high */ | |
| 220 | sourml=pu[2]; /* then the mid-low */ | |
| 221 | sourlo=pu[3]; /* then the low int */ | |
| 222 | } | |
| 223 | ||
| 224 | comb=(sourhi>>26)&0x1f; /* combination field */ | |
| 225 | ||
| 226 | decNumberZero(dn); /* clean number */ | |
| 227 | if (sourhi&0x80000000) dn->bits=DECNEG; /* set sign if negative */ | |
| 228 | ||
| 229 | msd=COMBMSD[comb]; /* decode the combination field */ | |
| 230 | exp=COMBEXP[comb]; /* .. */ | |
| 231 | ||
| 232 | if (exp==3) { /* is a special */ | |
| 233 | if (msd==0) { | |
| 234 | dn->bits|=DECINF; | |
| 235 | return dn; /* no coefficient needed */ | |
| 236 | } | |
| 237 | else if (sourhi&0x02000000) dn->bits|=DECSNAN; | |
| 238 | else dn->bits|=DECNAN; | |
| 239 | msd=0; /* no top digit */ | |
| 240 | } | |
| 241 | else { /* is a finite number */ | |
| 242 | dn->exponent=(exp<<12)+((sourhi>>14)&0xfff)-DECIMAL128_Bias; /* unbiased */ | |
| 243 | } | |
| 244 | ||
| 245 | /* get the coefficient */ | |
| 246 | sourhi&=0x00003fff; /* clean coefficient continuation */ | |
| 247 | if (msd) { /* non-zero msd */ | |
| 248 | sourhi|=msd<<14; /* prefix to coefficient */ | |
| 249 | need=12; /* process 12 declets */ | |
| 250 | } | |
| 251 | else { /* msd=0 */ | |
| 252 | if (sourhi) need=11; /* declets to process */ | |
| 253 | else if (sourmh) need=10; | |
| 254 | else if (sourml) need=7; | |
| 255 | else if (sourlo) need=4; | |
| 256 | else return dn; /* easy: coefficient is 0 */ | |
| 257 | } /*msd=0 */ | |
| 258 | ||
| 259 | decDigitsFromDPD(dn, sourar, need); /* process declets */ | |
| 260 | /* decNumberShow(dn); */ | |
| 261 | return dn; | |
| 262 | } /* decimal128ToNumber */ | |
| 263 | ||
| 264 | /* ------------------------------------------------------------------ */ | |
| 265 | /* to-scientific-string -- conversion to numeric string */ | |
| 266 | /* to-engineering-string -- conversion to numeric string */ | |
| 267 | /* */ | |
| 268 | /* decimal128ToString(d128, string); */ | |
| 269 | /* decimal128ToEngString(d128, string); */ | |
| 270 | /* */ | |
| 271 | /* d128 is the decimal128 format number to convert */ | |
| 272 | /* string is the string where the result will be laid out */ | |
| 273 | /* */ | |
| 274 | /* string must be at least 24 characters */ | |
| 275 | /* */ | |
| 276 | /* No error is possible, and no status can be set. */ | |
| 277 | /* ------------------------------------------------------------------ */ | |
| 278 | char * decimal128ToEngString(const decimal128 *d128, char *string){ | |
| 279 | decNumber dn; /* work */ | |
| 280 | decimal128ToNumber(d128, &dn); | |
| 281 | decNumberToEngString(&dn, string); | |
| 282 | return string; | |
| 283 | } /* decimal128ToEngString */ | |
| 284 | ||
| 285 | char * decimal128ToString(const decimal128 *d128, char *string){ | |
| 286 | uInt msd; /* coefficient MSD */ | |
| 287 | Int exp; /* exponent top two bits or full */ | |
| 288 | uInt comb; /* combination field */ | |
| 289 | char *cstart; /* coefficient start */ | |
| 290 | char *c; /* output pointer in string */ | |
| 291 | const uInt *pu; /* work */ | |
| 292 | char *s, *t; /* .. (source, target) */ | |
| 293 | Int dpd; /* .. */ | |
| 294 | Int pre, e; /* .. */ | |
| 295 | const uByte *u; /* .. */ | |
| 296 | ||
| 297 | uInt sourar[4]; /* source 128-bit */ | |
| 298 | #define sourhi sourar[3] /* name the word with the sign */ | |
| 299 | #define sourmh sourar[2] /* and the mid-high word */ | |
| 300 | #define sourml sourar[1] /* and the mod-low word */ | |
| 301 | #define sourlo sourar[0] /* and the lowest word */ | |
| 302 | ||
| 303 | /* load source from storage; this is endian */ | |
| 304 | pu=(const uInt *)d128->bytes; /* overlay */ | |
| 305 | if (DECLITEND) { | |
| 306 | sourlo=pu[0]; /* directly load the low int */ | |
| 307 | sourml=pu[1]; /* then the mid-low */ | |
| 308 | sourmh=pu[2]; /* then the mid-high */ | |
| 309 | sourhi=pu[3]; /* then the high int */ | |
| 310 | } | |
| 311 | else { | |
| 312 | sourhi=pu[0]; /* directly load the high int */ | |
| 313 | sourmh=pu[1]; /* then the mid-high */ | |
| 314 | sourml=pu[2]; /* then the mid-low */ | |
| 315 | sourlo=pu[3]; /* then the low int */ | |
| 316 | } | |
| 317 | ||
| 318 | c=string; /* where result will go */ | |
| 319 | if (((Int)sourhi)<0) *c++='-'; /* handle sign */ | |
| 320 | ||
| 321 | comb=(sourhi>>26)&0x1f; /* combination field */ | |
| 322 | msd=COMBMSD[comb]; /* decode the combination field */ | |
| 323 | exp=COMBEXP[comb]; /* .. */ | |
| 324 | ||
| 325 | if (exp==3) { | |
| 326 | if (msd==0) { /* infinity */ | |
| 327 | strcpy(c, "Inf"); | |
| 328 | strcpy(c+3, "inity"); | |
| 329 | return string; /* easy */ | |
| 330 | } | |
| 331 | if (sourhi&0x02000000) *c++='s'; /* sNaN */ | |
| 332 | strcpy(c, "NaN"); /* complete word */ | |
| 333 | c+=3; /* step past */ | |
| 334 | if (sourlo==0 && sourml==0 && sourmh==0 | |
| 335 | && (sourhi&0x0003ffff)==0) return string; /* zero payload */ | |
| 336 | /* otherwise drop through to add integer; set correct exp */ | |
| 337 | exp=0; msd=0; /* setup for following code */ | |
| 338 | } | |
| 339 | else exp=(exp<<12)+((sourhi>>14)&0xfff)-DECIMAL128_Bias; /* unbiased */ | |
| 340 | ||
| 341 | /* convert 34 digits of significand to characters */ | |
| 342 | cstart=c; /* save start of coefficient */ | |
| 343 | if (msd) *c++='0'+(char)msd; /* non-zero most significant digit */ | |
| 344 | ||
| 345 | /* Now decode the declets. After extracting each one, it is */ | |
| 346 | /* decoded to binary and then to a 4-char sequence by table lookup; */ | |
| 347 | /* the 4-chars are a 1-char length (significant digits, except 000 */ | |
| 348 | /* has length 0). This allows us to left-align the first declet */ | |
| 349 | /* with non-zero content, then remaining ones are full 3-char */ | |
| 350 | /* length. We use fixed-length memcpys because variable-length */ | |
| 351 | /* causes a subroutine call in GCC. (These are length 4 for speed */ | |
| 352 | /* and are safe because the array has an extra terminator byte.) */ | |
| 353 | #define dpd2char u=&BIN2CHAR[DPD2BIN[dpd]*4]; \ | |
| 354 | if (c!=cstart) {memcpy(c, u+1, 4); c+=3;} \ | |
| 355 | else if (*u) {memcpy(c, u+4-*u, 4); c+=*u;} | |
| 356 | dpd=(sourhi>>4)&0x3ff; /* declet 1 */ | |
| 357 | dpd2char; | |
| 358 | dpd=((sourhi&0xf)<<6) | (sourmh>>26); /* declet 2 */ | |
| 359 | dpd2char; | |
| 360 | dpd=(sourmh>>16)&0x3ff; /* declet 3 */ | |
| 361 | dpd2char; | |
| 362 | dpd=(sourmh>>6)&0x3ff; /* declet 4 */ | |
| 363 | dpd2char; | |
| 364 | dpd=((sourmh&0x3f)<<4) | (sourml>>28); /* declet 5 */ | |
| 365 | dpd2char; | |
| 366 | dpd=(sourml>>18)&0x3ff; /* declet 6 */ | |
| 367 | dpd2char; | |
| 368 | dpd=(sourml>>8)&0x3ff; /* declet 7 */ | |
| 369 | dpd2char; | |
| 370 | dpd=((sourml&0xff)<<2) | (sourlo>>30); /* declet 8 */ | |
| 371 | dpd2char; | |
| 372 | dpd=(sourlo>>20)&0x3ff; /* declet 9 */ | |
| 373 | dpd2char; | |
| 374 | dpd=(sourlo>>10)&0x3ff; /* declet 10 */ | |
| 375 | dpd2char; | |
| 376 | dpd=(sourlo)&0x3ff; /* declet 11 */ | |
| 377 | dpd2char; | |
| 378 | ||
| 379 | if (c==cstart) *c++='0'; /* all zeros -- make 0 */ | |
| 380 | ||
| 381 | if (exp==0) { /* integer or NaN case -- easy */ | |
| 382 | *c='\0'; /* terminate */ | |
| 383 | return string; | |
| 384 | } | |
| 385 | ||
| 386 | /* non-0 exponent */ | |
| 387 | e=0; /* assume no E */ | |
| 388 | pre=c-cstart+exp; | |
| 389 | /* [here, pre-exp is the digits count (==1 for zero)] */ | |
| 390 | if (exp>0 || pre<-5) { /* need exponential form */ | |
| 391 | e=pre-1; /* calculate E value */ | |
| 392 | pre=1; /* assume one digit before '.' */ | |
| 393 | } /* exponential form */ | |
| 394 | ||
| 395 | /* modify the coefficient, adding 0s, '.', and E+nn as needed */ | |
| 396 | s=c-1; /* source (LSD) */ | |
| 397 | if (pre>0) { /* ddd.ddd (plain), perhaps with E */ | |
| 398 | char *dotat=cstart+pre; | |
| 399 | if (dotat<c) { /* if embedded dot needed... */ | |
| 400 | t=c; /* target */ | |
| 401 | for (; s>=dotat; s--, t--) *t=*s; /* open the gap; leave t at gap */ | |
| 402 | *t='.'; /* insert the dot */ | |
| 403 | c++; /* length increased by one */ | |
| 404 | } | |
| 405 | ||
| 406 | /* finally add the E-part, if needed; it will never be 0, and has */ | |
| 407 | /* a maximum length of 4 digits */ | |
| 408 | if (e!=0) { | |
| 409 | *c++='E'; /* starts with E */ | |
| 410 | *c++='+'; /* assume positive */ | |
| 411 | if (e<0) { | |
| 412 | *(c-1)='-'; /* oops, need '-' */ | |
| 413 | e=-e; /* uInt, please */ | |
| 414 | } | |
| 415 | if (e<1000) { /* 3 (or fewer) digits case */ | |
| 416 | u=&BIN2CHAR[e*4]; /* -> length byte */ | |
| 417 | memcpy(c, u+4-*u, 4); /* copy fixed 4 characters [is safe] */ | |
| 418 | c+=*u; /* bump pointer appropriately */ | |
| 419 | } | |
| 420 | else { /* 4-digits */ | |
| 421 | Int thou=((e>>3)*1049)>>17; /* e/1000 */ | |
| 422 | Int rem=e-(1000*thou); /* e%1000 */ | |
| 423 | *c++='0'+(char)thou; | |
| 424 | u=&BIN2CHAR[rem*4]; /* -> length byte */ | |
| 425 | memcpy(c, u+1, 4); /* copy fixed 3+1 characters [is safe] */ | |
| 426 | c+=3; /* bump pointer, always 3 digits */ | |
| 427 | } | |
| 428 | } | |
| 429 | *c='\0'; /* add terminator */ | |
| 430 | /*printf("res %s\n", string); */ | |
| 431 | return string; | |
| 432 | } /* pre>0 */ | |
| 433 | ||
| 434 | /* -5<=pre<=0: here for plain 0.ddd or 0.000ddd forms (can never have E) */ | |
| 435 | t=c+1-pre; | |
| 436 | *(t+1)='\0'; /* can add terminator now */ | |
| 437 | for (; s>=cstart; s--, t--) *t=*s; /* shift whole coefficient right */ | |
| 438 | c=cstart; | |
| 439 | *c++='0'; /* always starts with 0. */ | |
| 440 | *c++='.'; | |
| 441 | for (; pre<0; pre++) *c++='0'; /* add any 0's after '.' */ | |
| 442 | /*printf("res %s\n", string); */ | |
| 443 | return string; | |
| 444 | } /* decimal128ToString */ | |
| 445 | ||
| 446 | /* ------------------------------------------------------------------ */ | |
| 447 | /* to-number -- conversion from numeric string */ | |
| 448 | /* */ | |
| 449 | /* decimal128FromString(result, string, set); */ | |
| 450 | /* */ | |
| 451 | /* result is the decimal128 format number which gets the result of */ | |
| 452 | /* the conversion */ | |
| 453 | /* *string is the character string which should contain a valid */ | |
| 454 | /* number (which may be a special value) */ | |
| 455 | /* set is the context */ | |
| 456 | /* */ | |
| 457 | /* The context is supplied to this routine is used for error handling */ | |
| 458 | /* (setting of status and traps) and for the rounding mode, only. */ | |
| 459 | /* If an error occurs, the result will be a valid decimal128 NaN. */ | |
| 460 | /* ------------------------------------------------------------------ */ | |
| 461 | decimal128 * decimal128FromString(decimal128 *result, const char *string, | |
| 462 | decContext *set) { | |
| 463 | decContext dc; /* work */ | |
| 464 | decNumber dn; /* .. */ | |
| 465 | ||
| 466 | decContextDefault(&dc, DEC_INIT_DECIMAL128); /* no traps, please */ | |
| 467 | dc.round=set->round; /* use supplied rounding */ | |
| 468 | ||
| 469 | decNumberFromString(&dn, string, &dc); /* will round if needed */ | |
| 470 | decimal128FromNumber(result, &dn, &dc); | |
| 471 | if (dc.status!=0) { /* something happened */ | |
| 472 | decContextSetStatus(set, dc.status); /* .. pass it on */ | |
| 473 | } | |
| 474 | return result; | |
| 475 | } /* decimal128FromString */ | |
| 476 | ||
| 477 | /* ------------------------------------------------------------------ */ | |
| 478 | /* decimal128IsCanonical -- test whether encoding is canonical */ | |
| 479 | /* d128 is the source decimal128 */ | |
| 480 | /* returns 1 if the encoding of d128 is canonical, 0 otherwise */ | |
| 481 | /* No error is possible. */ | |
| 482 | /* ------------------------------------------------------------------ */ | |
| 483 | uint32_t decimal128IsCanonical(const decimal128 *d128) { | |
| 484 | decNumber dn; /* work */ | |
| 485 | decimal128 canon; /* .. */ | |
| 486 | decContext dc; /* .. */ | |
| 487 | decContextDefault(&dc, DEC_INIT_DECIMAL128); | |
| 488 | decimal128ToNumber(d128, &dn); | |
| 489 | decimal128FromNumber(&canon, &dn, &dc);/* canon will now be canonical */ | |
| 490 | return memcmp(d128, &canon, DECIMAL128_Bytes)==0; | |
| 491 | } /* decimal128IsCanonical */ | |
| 492 | ||
| 493 | /* ------------------------------------------------------------------ */ | |
| 494 | /* decimal128Canonical -- copy an encoding, ensuring it is canonical */ | |
| 495 | /* d128 is the source decimal128 */ | |
| 496 | /* result is the target (may be the same decimal128) */ | |
| 497 | /* returns result */ | |
| 498 | /* No error is possible. */ | |
| 499 | /* ------------------------------------------------------------------ */ | |
| 500 | decimal128 * decimal128Canonical(decimal128 *result, const decimal128 *d128) { | |
| 501 | decNumber dn; /* work */ | |
| 502 | decContext dc; /* .. */ | |
| 503 | decContextDefault(&dc, DEC_INIT_DECIMAL128); | |
| 504 | decimal128ToNumber(d128, &dn); | |
| 505 | decimal128FromNumber(result, &dn, &dc);/* result will now be canonical */ | |
| 506 | return result; | |
| 507 | } /* decimal128Canonical */ | |
| 508 | ||
| 509 | #if DECTRACE || DECCHECK | |
| 510 | /* Macros for accessing decimal128 fields. These assume the argument | |
| 511 | is a reference (pointer) to the decimal128 structure, and the | |
| 512 | decimal128 is in network byte order (big-endian) */ | |
| 513 | /* Get sign */ | |
| 514 | #define decimal128Sign(d) ((unsigned)(d)->bytes[0]>>7) | |
| 515 | ||
| 516 | /* Get combination field */ | |
| 517 | #define decimal128Comb(d) (((d)->bytes[0] & 0x7c)>>2) | |
| 518 | ||
| 519 | /* Get exponent continuation [does not remove bias] */ | |
| 520 | #define decimal128ExpCon(d) ((((d)->bytes[0] & 0x03)<<10) \ | |
| 521 | | ((unsigned)(d)->bytes[1]<<2) \ | |
| 522 | | ((unsigned)(d)->bytes[2]>>6)) | |
| 523 | ||
| 524 | /* Set sign [this assumes sign previously 0] */ | |
| 525 | #define decimal128SetSign(d, b) { \ | |
| 526 | (d)->bytes[0]|=((unsigned)(b)<<7);} | |
| 527 | ||
| 528 | /* Set exponent continuation [does not apply bias] */ | |
| 529 | /* This assumes range has been checked and exponent previously 0; */ | |
| 530 | /* type of exponent must be unsigned */ | |
| 531 | #define decimal128SetExpCon(d, e) { \ | |
| 532 | (d)->bytes[0]|=(uint8_t)((e)>>10); \ | |
| 533 | (d)->bytes[1] =(uint8_t)(((e)&0x3fc)>>2); \ | |
| 534 | (d)->bytes[2]|=(uint8_t)(((e)&0x03)<<6);} | |
| 535 | ||
| 536 | /* ------------------------------------------------------------------ */ | |
| 537 | /* decimal128Show -- display a decimal128 in hexadecimal [debug aid] */ | |
| 538 | /* d128 -- the number to show */ | |
| 539 | /* ------------------------------------------------------------------ */ | |
| 540 | /* Also shows sign/cob/expconfields extracted */ | |
| 541 | void decimal128Show(const decimal128 *d128) { | |
| 542 | char buf[DECIMAL128_Bytes*2+1]; | |
| 543 | Int i, j=0; | |
| 544 | ||
| 545 | if (DECLITEND) { | |
| 546 | for (i=0; i<DECIMAL128_Bytes; i++, j+=2) { | |
| 547 | sprintf(&buf[j], "%02x", d128->bytes[15-i]); | |
| 548 | } | |
| 549 | printf(" D128> %s [S:%d Cb:%02x Ec:%02x] LittleEndian\n", buf, | |
| 550 | d128->bytes[15]>>7, (d128->bytes[15]>>2)&0x1f, | |
| 551 | ((d128->bytes[15]&0x3)<<10)|(d128->bytes[14]<<2)| | |
| 552 | (d128->bytes[13]>>6)); | |
| 553 | } | |
| 554 | else { | |
| 555 | for (i=0; i<DECIMAL128_Bytes; i++, j+=2) { | |
| 556 | sprintf(&buf[j], "%02x", d128->bytes[i]); | |
| 557 | } | |
| 558 | printf(" D128> %s [S:%d Cb:%02x Ec:%02x] BigEndian\n", buf, | |
| 559 | decimal128Sign(d128), decimal128Comb(d128), | |
| 560 | decimal128ExpCon(d128)); | |
| 561 | } | |
| 562 | } /* decimal128Show */ | |
| 563 | #endif |