github.com/matrixorigin/matrixone@v0.7.0/cgo/external/decNumber/decimal32.c (about) 1 /* ------------------------------------------------------------------ */ 2 /* Decimal 32-bit format module */ 3 /* ------------------------------------------------------------------ */ 4 /* Copyright (c) IBM Corporation, 2000, 2008. 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 decimal32 format numbers. */ 20 /* Conversions are supplied to and from decNumber and String. */ 21 /* */ 22 /* This is used when decNumber provides operations, either for all */ 23 /* operations or as a proxy between decNumber and decSingle. */ 24 /* */ 25 /* Error handling is the same as decNumber (qv.). */ 26 /* ------------------------------------------------------------------ */ 27 #include <string.h> // [for memset/memcpy] 28 #include <stdio.h> // [for printf] 29 30 #define DECNUMDIGITS 7 // make decNumbers with space for 7 31 #include "decNumber.h" // base number library 32 #include "decNumberLocal.h" // decNumber local types, etc. 33 #include "decimal32.h" // our primary include 34 35 /* Utility tables and routines [in decimal64.c] */ 36 // DPD2BIN and the reverse are renamed to prevent link-time conflict 37 // if decQuad is also built in the same executable 38 #define DPD2BIN DPD2BINx 39 #define BIN2DPD BIN2DPDx 40 extern const uInt COMBEXP[32], COMBMSD[32]; 41 extern const uShort DPD2BIN[1024]; 42 extern const uShort BIN2DPD[1000]; 43 extern const uByte BIN2CHAR[4001]; 44 45 extern void decDigitsToDPD(const decNumber *, uInt *, Int); 46 extern void decDigitsFromDPD(decNumber *, const uInt *, Int); 47 48 #if DECTRACE || DECCHECK 49 void decimal32Show(const decimal32 *); // for debug 50 extern void decNumberShow(const decNumber *); // .. 51 #endif 52 53 /* Useful macro */ 54 // Clear a structure (e.g., a decNumber) 55 #define DEC_clear(d) memset(d, 0, sizeof(*d)) 56 57 /* ------------------------------------------------------------------ */ 58 /* decimal32FromNumber -- convert decNumber to decimal32 */ 59 /* */ 60 /* ds is the target decimal32 */ 61 /* dn is the source number (assumed valid) */ 62 /* set is the context, used only for reporting errors */ 63 /* */ 64 /* The set argument is used only for status reporting and for the */ 65 /* rounding mode (used if the coefficient is more than DECIMAL32_Pmax */ 66 /* digits or an overflow is detected). If the exponent is out of the */ 67 /* valid range then Overflow or Underflow will be raised. */ 68 /* After Underflow a subnormal result is possible. */ 69 /* */ 70 /* DEC_Clamped is set if the number has to be 'folded down' to fit, */ 71 /* by reducing its exponent and multiplying the coefficient by a */ 72 /* power of ten, or if the exponent on a zero had to be clamped. */ 73 /* ------------------------------------------------------------------ */ 74 decimal32 * decimal32FromNumber(decimal32 *d32, const decNumber *dn, 75 decContext *set) { 76 uInt status=0; // status accumulator 77 Int ae; // adjusted exponent 78 decNumber dw; // work 79 decContext dc; // .. 80 uInt comb, exp; // .. 81 uInt uiwork; // for macros 82 uInt targ=0; // target 32-bit 83 84 // If the number has too many digits, or the exponent could be 85 // out of range then reduce the number under the appropriate 86 // constraints. This could push the number to Infinity or zero, 87 // so this check and rounding must be done before generating the 88 // decimal32] 89 ae=dn->exponent+dn->digits-1; // [0 if special] 90 if (dn->digits>DECIMAL32_Pmax // too many digits 91 || ae>DECIMAL32_Emax // likely overflow 92 || ae<DECIMAL32_Emin) { // likely underflow 93 decContextDefault(&dc, DEC_INIT_DECIMAL32); // [no traps] 94 dc.round=set->round; // use supplied rounding 95 decNumberPlus(&dw, dn, &dc); // (round and check) 96 // [this changes -0 to 0, so enforce the sign...] 97 dw.bits|=dn->bits&DECNEG; 98 status=dc.status; // save status 99 dn=&dw; // use the work number 100 } // maybe out of range 101 102 if (dn->bits&DECSPECIAL) { // a special value 103 if (dn->bits&DECINF) targ=DECIMAL_Inf<<24; 104 else { // sNaN or qNaN 105 if ((*dn->lsu!=0 || dn->digits>1) // non-zero coefficient 106 && (dn->digits<DECIMAL32_Pmax)) { // coefficient fits 107 decDigitsToDPD(dn, &targ, 0); 108 } 109 if (dn->bits&DECNAN) targ|=DECIMAL_NaN<<24; 110 else targ|=DECIMAL_sNaN<<24; 111 } // a NaN 112 } // special 113 114 else { // is finite 115 if (decNumberIsZero(dn)) { // is a zero 116 // set and clamp exponent 117 if (dn->exponent<-DECIMAL32_Bias) { 118 exp=0; // low clamp 119 status|=DEC_Clamped; 120 } 121 else { 122 exp=dn->exponent+DECIMAL32_Bias; // bias exponent 123 if (exp>DECIMAL32_Ehigh) { // top clamp 124 exp=DECIMAL32_Ehigh; 125 status|=DEC_Clamped; 126 } 127 } 128 comb=(exp>>3) & 0x18; // msd=0, exp top 2 bits .. 129 } 130 else { // non-zero finite number 131 uInt msd; // work 132 Int pad=0; // coefficient pad digits 133 134 // the dn is known to fit, but it may need to be padded 135 exp=(uInt)(dn->exponent+DECIMAL32_Bias); // bias exponent 136 if (exp>DECIMAL32_Ehigh) { // fold-down case 137 pad=exp-DECIMAL32_Ehigh; 138 exp=DECIMAL32_Ehigh; // [to maximum] 139 status|=DEC_Clamped; 140 } 141 142 // fastpath common case 143 if (DECDPUN==3 && pad==0) { 144 targ=BIN2DPD[dn->lsu[0]]; 145 if (dn->digits>3) targ|=(uInt)(BIN2DPD[dn->lsu[1]])<<10; 146 msd=(dn->digits==7 ? dn->lsu[2] : 0); 147 } 148 else { // general case 149 decDigitsToDPD(dn, &targ, pad); 150 // save and clear the top digit 151 msd=targ>>20; 152 targ&=0x000fffff; 153 } 154 155 // create the combination field 156 if (msd>=8) comb=0x18 | ((exp>>5) & 0x06) | (msd & 0x01); 157 else comb=((exp>>3) & 0x18) | msd; 158 } 159 targ|=comb<<26; // add combination field .. 160 targ|=(exp&0x3f)<<20; // .. and exponent continuation 161 } // finite 162 163 if (dn->bits&DECNEG) targ|=0x80000000; // add sign bit 164 165 // now write to storage; this is endian 166 UBFROMUI(d32->bytes, targ); // directly store the int 167 168 if (status!=0) decContextSetStatus(set, status); // pass on status 169 // decimal32Show(d32); 170 return d32; 171 } // decimal32FromNumber 172 173 /* ------------------------------------------------------------------ */ 174 /* decimal32ToNumber -- convert decimal32 to decNumber */ 175 /* d32 is the source decimal32 */ 176 /* dn is the target number, with appropriate space */ 177 /* No error is possible. */ 178 /* ------------------------------------------------------------------ */ 179 decNumber * decimal32ToNumber(const decimal32 *d32, decNumber *dn) { 180 uInt msd; // coefficient MSD 181 uInt exp; // exponent top two bits 182 uInt comb; // combination field 183 uInt sour; // source 32-bit 184 uInt uiwork; // for macros 185 186 // load source from storage; this is endian 187 sour=UBTOUI(d32->bytes); // directly load the int 188 189 comb=(sour>>26)&0x1f; // combination field 190 191 decNumberZero(dn); // clean number 192 if (sour&0x80000000) dn->bits=DECNEG; // set sign if negative 193 194 msd=COMBMSD[comb]; // decode the combination field 195 exp=COMBEXP[comb]; // .. 196 197 if (exp==3) { // is a special 198 if (msd==0) { 199 dn->bits|=DECINF; 200 return dn; // no coefficient needed 201 } 202 else if (sour&0x02000000) dn->bits|=DECSNAN; 203 else dn->bits|=DECNAN; 204 msd=0; // no top digit 205 } 206 else { // is a finite number 207 dn->exponent=(exp<<6)+((sour>>20)&0x3f)-DECIMAL32_Bias; // unbiased 208 } 209 210 // get the coefficient 211 sour&=0x000fffff; // clean coefficient continuation 212 if (msd) { // non-zero msd 213 sour|=msd<<20; // prefix to coefficient 214 decDigitsFromDPD(dn, &sour, 3); // process 3 declets 215 return dn; 216 } 217 // msd=0 218 if (!sour) return dn; // easy: coefficient is 0 219 if (sour&0x000ffc00) // need 2 declets? 220 decDigitsFromDPD(dn, &sour, 2); // process 2 declets 221 else 222 decDigitsFromDPD(dn, &sour, 1); // process 1 declet 223 return dn; 224 } // decimal32ToNumber 225 226 /* ------------------------------------------------------------------ */ 227 /* to-scientific-string -- conversion to numeric string */ 228 /* to-engineering-string -- conversion to numeric string */ 229 /* */ 230 /* decimal32ToString(d32, string); */ 231 /* decimal32ToEngString(d32, string); */ 232 /* */ 233 /* d32 is the decimal32 format number to convert */ 234 /* string is the string where the result will be laid out */ 235 /* */ 236 /* string must be at least 24 characters */ 237 /* */ 238 /* No error is possible, and no status can be set. */ 239 /* ------------------------------------------------------------------ */ 240 char * decimal32ToEngString(const decimal32 *d32, char *string){ 241 decNumber dn; // work 242 decimal32ToNumber(d32, &dn); 243 decNumberToEngString(&dn, string); 244 return string; 245 } // decimal32ToEngString 246 247 char * decimal32ToString(const decimal32 *d32, char *string){ 248 uInt msd; // coefficient MSD 249 Int exp; // exponent top two bits or full 250 uInt comb; // combination field 251 char *cstart; // coefficient start 252 char *c; // output pointer in string 253 const uByte *u; // work 254 char *s, *t; // .. (source, target) 255 Int dpd; // .. 256 Int pre, e; // .. 257 uInt uiwork; // for macros 258 uInt sour; // source 32-bit 259 260 // load source from storage; this is endian 261 sour=UBTOUI(d32->bytes); // directly load the int 262 263 c=string; // where result will go 264 if (((Int)sour)<0) *c++='-'; // handle sign 265 266 comb=(sour>>26)&0x1f; // combination field 267 msd=COMBMSD[comb]; // decode the combination field 268 exp=COMBEXP[comb]; // .. 269 270 if (exp==3) { 271 if (msd==0) { // infinity 272 strcpy(c, "Inf"); 273 strcpy(c+3, "inity"); 274 return string; // easy 275 } 276 if (sour&0x02000000) *c++='s'; // sNaN 277 strcpy(c, "NaN"); // complete word 278 c+=3; // step past 279 if ((sour&0x000fffff)==0) return string; // zero payload 280 // otherwise drop through to add integer; set correct exp 281 exp=0; msd=0; // setup for following code 282 } 283 else exp=(exp<<6)+((sour>>20)&0x3f)-DECIMAL32_Bias; // unbiased 284 285 // convert 7 digits of significand to characters 286 cstart=c; // save start of coefficient 287 if (msd) *c++='0'+(char)msd; // non-zero most significant digit 288 289 // Now decode the declets. After extracting each one, it is 290 // decoded to binary and then to a 4-char sequence by table lookup; 291 // the 4-chars are a 1-char length (significant digits, except 000 292 // has length 0). This allows us to left-align the first declet 293 // with non-zero content, then remaining ones are full 3-char 294 // length. We use fixed-length memcpys because variable-length 295 // causes a subroutine call in GCC. (These are length 4 for speed 296 // and are safe because the array has an extra terminator byte.) 297 #define dpd2char u=&BIN2CHAR[DPD2BIN[dpd]*4]; \ 298 if (c!=cstart) {memcpy(c, u+1, 4); c+=3;} \ 299 else if (*u) {memcpy(c, u+4-*u, 4); c+=*u;} 300 301 dpd=(sour>>10)&0x3ff; // declet 1 302 dpd2char; 303 dpd=(sour)&0x3ff; // declet 2 304 dpd2char; 305 306 if (c==cstart) *c++='0'; // all zeros -- make 0 307 308 if (exp==0) { // integer or NaN case -- easy 309 *c='\0'; // terminate 310 return string; 311 } 312 313 /* non-0 exponent */ 314 e=0; // assume no E 315 pre=c-cstart+exp; 316 // [here, pre-exp is the digits count (==1 for zero)] 317 if (exp>0 || pre<-5) { // need exponential form 318 e=pre-1; // calculate E value 319 pre=1; // assume one digit before '.' 320 } // exponential form 321 322 /* modify the coefficient, adding 0s, '.', and E+nn as needed */ 323 s=c-1; // source (LSD) 324 if (pre>0) { // ddd.ddd (plain), perhaps with E 325 char *dotat=cstart+pre; 326 if (dotat<c) { // if embedded dot needed... 327 t=c; // target 328 for (; s>=dotat; s--, t--) *t=*s; // open the gap; leave t at gap 329 *t='.'; // insert the dot 330 c++; // length increased by one 331 } 332 333 // finally add the E-part, if needed; it will never be 0, and has 334 // a maximum length of 3 digits (E-101 case) 335 if (e!=0) { 336 *c++='E'; // starts with E 337 *c++='+'; // assume positive 338 if (e<0) { 339 *(c-1)='-'; // oops, need '-' 340 e=-e; // uInt, please 341 } 342 u=&BIN2CHAR[e*4]; // -> length byte 343 memcpy(c, u+4-*u, 4); // copy fixed 4 characters [is safe] 344 c+=*u; // bump pointer appropriately 345 } 346 *c='\0'; // add terminator 347 //printf("res %s\n", string); 348 return string; 349 } // pre>0 350 351 /* -5<=pre<=0: here for plain 0.ddd or 0.000ddd forms (can never have E) */ 352 t=c+1-pre; 353 *(t+1)='\0'; // can add terminator now 354 for (; s>=cstart; s--, t--) *t=*s; // shift whole coefficient right 355 c=cstart; 356 *c++='0'; // always starts with 0. 357 *c++='.'; 358 for (; pre<0; pre++) *c++='0'; // add any 0's after '.' 359 //printf("res %s\n", string); 360 return string; 361 } // decimal32ToString 362 363 /* ------------------------------------------------------------------ */ 364 /* to-number -- conversion from numeric string */ 365 /* */ 366 /* decimal32FromString(result, string, set); */ 367 /* */ 368 /* result is the decimal32 format number which gets the result of */ 369 /* the conversion */ 370 /* *string is the character string which should contain a valid */ 371 /* number (which may be a special value) */ 372 /* set is the context */ 373 /* */ 374 /* The context is supplied to this routine is used for error handling */ 375 /* (setting of status and traps) and for the rounding mode, only. */ 376 /* If an error occurs, the result will be a valid decimal32 NaN. */ 377 /* ------------------------------------------------------------------ */ 378 decimal32 * decimal32FromString(decimal32 *result, const char *string, 379 decContext *set) { 380 decContext dc; // work 381 decNumber dn; // .. 382 383 decContextDefault(&dc, DEC_INIT_DECIMAL32); // no traps, please 384 dc.round=set->round; // use supplied rounding 385 386 decNumberFromString(&dn, string, &dc); // will round if needed 387 decimal32FromNumber(result, &dn, &dc); 388 if (dc.status!=0) { // something happened 389 decContextSetStatus(set, dc.status); // .. pass it on 390 } 391 return result; 392 } // decimal32FromString 393 394 /* ------------------------------------------------------------------ */ 395 /* decimal32IsCanonical -- test whether encoding is canonical */ 396 /* d32 is the source decimal32 */ 397 /* returns 1 if the encoding of d32 is canonical, 0 otherwise */ 398 /* No error is possible. */ 399 /* ------------------------------------------------------------------ */ 400 uInt decimal32IsCanonical(const decimal32 *d32) { 401 decNumber dn; // work 402 decimal32 canon; // .. 403 decContext dc; // .. 404 decContextDefault(&dc, DEC_INIT_DECIMAL32); 405 decimal32ToNumber(d32, &dn); 406 decimal32FromNumber(&canon, &dn, &dc);// canon will now be canonical 407 return memcmp(d32, &canon, DECIMAL32_Bytes)==0; 408 } // decimal32IsCanonical 409 410 /* ------------------------------------------------------------------ */ 411 /* decimal32Canonical -- copy an encoding, ensuring it is canonical */ 412 /* d32 is the source decimal32 */ 413 /* result is the target (may be the same decimal32) */ 414 /* returns result */ 415 /* No error is possible. */ 416 /* ------------------------------------------------------------------ */ 417 decimal32 * decimal32Canonical(decimal32 *result, const decimal32 *d32) { 418 decNumber dn; // work 419 decContext dc; // .. 420 decContextDefault(&dc, DEC_INIT_DECIMAL32); 421 decimal32ToNumber(d32, &dn); 422 decimal32FromNumber(result, &dn, &dc);// result will now be canonical 423 return result; 424 } // decimal32Canonical 425 426 #if DECTRACE || DECCHECK 427 /* Macros for accessing decimal32 fields. These assume the argument 428 is a reference (pointer) to the decimal32 structure, and the 429 decimal32 is in network byte order (big-endian) */ 430 // Get sign 431 #define decimal32Sign(d) ((unsigned)(d)->bytes[0]>>7) 432 433 // Get combination field 434 #define decimal32Comb(d) (((d)->bytes[0] & 0x7c)>>2) 435 436 // Get exponent continuation [does not remove bias] 437 #define decimal32ExpCon(d) ((((d)->bytes[0] & 0x03)<<4) \ 438 | ((unsigned)(d)->bytes[1]>>4)) 439 440 // Set sign [this assumes sign previously 0] 441 #define decimal32SetSign(d, b) { \ 442 (d)->bytes[0]|=((unsigned)(b)<<7);} 443 444 // Set exponent continuation [does not apply bias] 445 // This assumes range has been checked and exponent previously 0; 446 // type of exponent must be unsigned 447 #define decimal32SetExpCon(d, e) { \ 448 (d)->bytes[0]|=(uByte)((e)>>4); \ 449 (d)->bytes[1]|=(uByte)(((e)&0x0F)<<4);} 450 451 /* ------------------------------------------------------------------ */ 452 /* decimal32Show -- display a decimal32 in hexadecimal [debug aid] */ 453 /* d32 -- the number to show */ 454 /* ------------------------------------------------------------------ */ 455 // Also shows sign/cob/expconfields extracted - valid bigendian only 456 void decimal32Show(const decimal32 *d32) { 457 char buf[DECIMAL32_Bytes*2+1]; 458 Int i, j=0; 459 460 if (DECLITEND) { 461 for (i=0; i<DECIMAL32_Bytes; i++, j+=2) { 462 sprintf(&buf[j], "%02x", d32->bytes[3-i]); 463 } 464 printf(" D32> %s [S:%d Cb:%02x Ec:%02x] LittleEndian\n", buf, 465 d32->bytes[3]>>7, (d32->bytes[3]>>2)&0x1f, 466 ((d32->bytes[3]&0x3)<<4)| (d32->bytes[2]>>4)); 467 } 468 else { 469 for (i=0; i<DECIMAL32_Bytes; i++, j+=2) { 470 sprintf(&buf[j], "%02x", d32->bytes[i]); 471 } 472 printf(" D32> %s [S:%d Cb:%02x Ec:%02x] BigEndian\n", buf, 473 decimal32Sign(d32), decimal32Comb(d32), decimal32ExpCon(d32)); 474 } 475 } // decimal32Show 476 #endif