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1 | /* Decimal 64-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 64-bit format module */ | |
33 | /* ------------------------------------------------------------------ */ | |
34 | /* This module comprises the routines for decimal64 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 | /* ------------------------------------------------------------------ */ | |
42 | #include <string.h> /* [for memset/memcpy] */ | |
43 | #include <stdio.h> /* [for printf] */ | |
44 | ||
45 | #include "config.h" /* GCC definitions */ | |
46 | #define DECNUMDIGITS 16 /* make decNumbers with space for 16 */ | |
47 | #include "decNumber.h" /* base number library */ | |
48 | #include "decNumberLocal.h" /* decNumber local types, etc. */ | |
49 | #include "decimal64.h" /* our primary include */ | |
50 | ||
51 | /* Utility routines and tables [in decimal64.c]; externs for C++ */ | |
52 | /* DPD2BIN and the reverse are renamed to prevent link-time conflict */ | |
53 | /* if decQuad is also built in the same executable */ | |
54 | #define DPD2BIN DPD2BINx | |
55 | #define BIN2DPD BIN2DPDx | |
56 | extern const uInt COMBEXP[32], COMBMSD[32]; | |
57 | extern const uShort DPD2BIN[1024]; | |
58 | extern const uShort BIN2DPD[1000]; | |
59 | extern const uByte BIN2CHAR[4001]; | |
60 | ||
61 | extern void decDigitsFromDPD(decNumber *, const uInt *, Int); | |
62 | extern void decDigitsToDPD(const decNumber *, uInt *, Int); | |
63 | ||
64 | #if DECTRACE || DECCHECK | |
65 | void decimal64Show(const decimal64 *); /* for debug */ | |
66 | extern void decNumberShow(const decNumber *); /* .. */ | |
67 | #endif | |
68 | ||
69 | /* Useful macro */ | |
70 | /* Clear a structure (e.g., a decNumber) */ | |
71 | #define DEC_clear(d) memset(d, 0, sizeof(*d)) | |
72 | ||
73 | /* define and include the tables to use for conversions */ | |
74 | #define DEC_BIN2CHAR 1 | |
75 | #define DEC_DPD2BIN 1 | |
76 | #define DEC_BIN2DPD 1 /* used for all sizes */ | |
77 | #include "decDPD.h" /* lookup tables */ | |
78 | ||
79 | /* ------------------------------------------------------------------ */ | |
80 | /* decimal64FromNumber -- convert decNumber to decimal64 */ | |
81 | /* */ | |
82 | /* ds is the target decimal64 */ | |
83 | /* dn is the source number (assumed valid) */ | |
84 | /* set is the context, used only for reporting errors */ | |
85 | /* */ | |
86 | /* The set argument is used only for status reporting and for the */ | |
87 | /* rounding mode (used if the coefficient is more than DECIMAL64_Pmax */ | |
88 | /* digits or an overflow is detected). If the exponent is out of the */ | |
89 | /* valid range then Overflow or Underflow will be raised. */ | |
90 | /* After Underflow a subnormal result is possible. */ | |
91 | /* */ | |
92 | /* DEC_Clamped is set if the number has to be 'folded down' to fit, */ | |
93 | /* by reducing its exponent and multiplying the coefficient by a */ | |
94 | /* power of ten, or if the exponent on a zero had to be clamped. */ | |
95 | /* ------------------------------------------------------------------ */ | |
96 | decimal64 * decimal64FromNumber(decimal64 *d64, const decNumber *dn, | |
97 | decContext *set) { | |
98 | uInt status=0; /* status accumulator */ | |
99 | Int ae; /* adjusted exponent */ | |
100 | decNumber dw; /* work */ | |
101 | decContext dc; /* .. */ | |
102 | uInt *pu; /* .. */ | |
103 | uInt comb, exp; /* .. */ | |
104 | uInt targar[2]={0, 0}; /* target 64-bit */ | |
105 | #define targhi targar[1] /* name the word with the sign */ | |
106 | #define targlo targar[0] /* and the other */ | |
107 | ||
108 | /* If the number has too many digits, or the exponent could be */ | |
109 | /* out of range then reduce the number under the appropriate */ | |
110 | /* constraints. This could push the number to Infinity or zero, */ | |
111 | /* so this check and rounding must be done before generating the */ | |
112 | /* decimal64] */ | |
113 | ae=dn->exponent+dn->digits-1; /* [0 if special] */ | |
114 | if (dn->digits>DECIMAL64_Pmax /* too many digits */ | |
115 | || ae>DECIMAL64_Emax /* likely overflow */ | |
116 | || ae<DECIMAL64_Emin) { /* likely underflow */ | |
117 | decContextDefault(&dc, DEC_INIT_DECIMAL64); /* [no traps] */ | |
118 | dc.round=set->round; /* use supplied rounding */ | |
119 | decNumberPlus(&dw, dn, &dc); /* (round and check) */ | |
120 | /* [this changes -0 to 0, so enforce the sign...] */ | |
121 | dw.bits|=dn->bits&DECNEG; | |
122 | status=dc.status; /* save status */ | |
123 | dn=&dw; /* use the work number */ | |
124 | } /* maybe out of range */ | |
125 | ||
126 | if (dn->bits&DECSPECIAL) { /* a special value */ | |
127 | if (dn->bits&DECINF) targhi=DECIMAL_Inf<<24; | |
128 | else { /* sNaN or qNaN */ | |
129 | if ((*dn->lsu!=0 || dn->digits>1) /* non-zero coefficient */ | |
130 | && (dn->digits<DECIMAL64_Pmax)) { /* coefficient fits */ | |
131 | decDigitsToDPD(dn, targar, 0); | |
132 | } | |
133 | if (dn->bits&DECNAN) targhi|=DECIMAL_NaN<<24; | |
134 | else targhi|=DECIMAL_sNaN<<24; | |
135 | } /* a NaN */ | |
136 | } /* special */ | |
137 | ||
138 | else { /* is finite */ | |
139 | if (decNumberIsZero(dn)) { /* is a zero */ | |
140 | /* set and clamp exponent */ | |
141 | if (dn->exponent<-DECIMAL64_Bias) { | |
142 | exp=0; /* low clamp */ | |
143 | status|=DEC_Clamped; | |
144 | } | |
145 | else { | |
146 | exp=dn->exponent+DECIMAL64_Bias; /* bias exponent */ | |
147 | if (exp>DECIMAL64_Ehigh) { /* top clamp */ | |
148 | exp=DECIMAL64_Ehigh; | |
149 | status|=DEC_Clamped; | |
150 | } | |
151 | } | |
152 | comb=(exp>>5) & 0x18; /* msd=0, exp top 2 bits .. */ | |
153 | } | |
154 | else { /* non-zero finite number */ | |
155 | uInt msd; /* work */ | |
156 | Int pad=0; /* coefficient pad digits */ | |
157 | ||
158 | /* the dn is known to fit, but it may need to be padded */ | |
159 | exp=(uInt)(dn->exponent+DECIMAL64_Bias); /* bias exponent */ | |
160 | if (exp>DECIMAL64_Ehigh) { /* fold-down case */ | |
161 | pad=exp-DECIMAL64_Ehigh; | |
162 | exp=DECIMAL64_Ehigh; /* [to maximum] */ | |
163 | status|=DEC_Clamped; | |
164 | } | |
165 | ||
166 | /* fastpath common case */ | |
167 | if (DECDPUN==3 && pad==0) { | |
168 | uInt dpd[6]={0,0,0,0,0,0}; | |
169 | uInt i; | |
170 | Int d=dn->digits; | |
171 | for (i=0; d>0; i++, d-=3) dpd[i]=BIN2DPD[dn->lsu[i]]; | |
172 | targlo =dpd[0]; | |
173 | targlo|=dpd[1]<<10; | |
174 | targlo|=dpd[2]<<20; | |
175 | if (dn->digits>6) { | |
176 | targlo|=dpd[3]<<30; | |
177 | targhi =dpd[3]>>2; | |
178 | targhi|=dpd[4]<<8; | |
179 | } | |
180 | msd=dpd[5]; /* [did not really need conversion] */ | |
181 | } | |
182 | else { /* general case */ | |
183 | decDigitsToDPD(dn, targar, pad); | |
184 | /* save and clear the top digit */ | |
185 | msd=targhi>>18; | |
186 | targhi&=0x0003ffff; | |
187 | } | |
188 | ||
189 | /* create the combination field */ | |
190 | if (msd>=8) comb=0x18 | ((exp>>7) & 0x06) | (msd & 0x01); | |
191 | else comb=((exp>>5) & 0x18) | msd; | |
192 | } | |
193 | targhi|=comb<<26; /* add combination field .. */ | |
194 | targhi|=(exp&0xff)<<18; /* .. and exponent continuation */ | |
195 | } /* finite */ | |
196 | ||
197 | if (dn->bits&DECNEG) targhi|=0x80000000; /* add sign bit */ | |
198 | ||
199 | /* now write to storage; this is now always endian */ | |
200 | pu=(uInt *)d64->bytes; /* overlay */ | |
201 | if (DECLITEND) { | |
202 | pu[0]=targar[0]; /* directly store the low int */ | |
203 | pu[1]=targar[1]; /* then the high int */ | |
204 | } | |
205 | else { | |
206 | pu[0]=targar[1]; /* directly store the high int */ | |
207 | pu[1]=targar[0]; /* then the low int */ | |
208 | } | |
209 | ||
210 | if (status!=0) decContextSetStatus(set, status); /* pass on status */ | |
211 | /* decimal64Show(d64); */ | |
212 | return d64; | |
213 | } /* decimal64FromNumber */ | |
214 | ||
215 | /* ------------------------------------------------------------------ */ | |
216 | /* decimal64ToNumber -- convert decimal64 to decNumber */ | |
217 | /* d64 is the source decimal64 */ | |
218 | /* dn is the target number, with appropriate space */ | |
219 | /* No error is possible. */ | |
220 | /* ------------------------------------------------------------------ */ | |
221 | decNumber * decimal64ToNumber(const decimal64 *d64, decNumber *dn) { | |
222 | uInt msd; /* coefficient MSD */ | |
223 | uInt exp; /* exponent top two bits */ | |
224 | uInt comb; /* combination field */ | |
225 | const uInt *pu; /* work */ | |
226 | Int need; /* .. */ | |
227 | uInt sourar[2]; /* source 64-bit */ | |
228 | #define sourhi sourar[1] /* name the word with the sign */ | |
229 | #define sourlo sourar[0] /* and the lower word */ | |
230 | ||
231 | /* load source from storage; this is endian */ | |
232 | pu=(const uInt *)d64->bytes; /* overlay */ | |
233 | if (DECLITEND) { | |
234 | sourlo=pu[0]; /* directly load the low int */ | |
235 | sourhi=pu[1]; /* then the high int */ | |
236 | } | |
237 | else { | |
238 | sourhi=pu[0]; /* directly load the high int */ | |
239 | sourlo=pu[1]; /* then the low int */ | |
240 | } | |
241 | ||
242 | comb=(sourhi>>26)&0x1f; /* combination field */ | |
243 | ||
244 | decNumberZero(dn); /* clean number */ | |
245 | if (sourhi&0x80000000) dn->bits=DECNEG; /* set sign if negative */ | |
246 | ||
247 | msd=COMBMSD[comb]; /* decode the combination field */ | |
248 | exp=COMBEXP[comb]; /* .. */ | |
249 | ||
250 | if (exp==3) { /* is a special */ | |
251 | if (msd==0) { | |
252 | dn->bits|=DECINF; | |
253 | return dn; /* no coefficient needed */ | |
254 | } | |
255 | else if (sourhi&0x02000000) dn->bits|=DECSNAN; | |
256 | else dn->bits|=DECNAN; | |
257 | msd=0; /* no top digit */ | |
258 | } | |
259 | else { /* is a finite number */ | |
260 | dn->exponent=(exp<<8)+((sourhi>>18)&0xff)-DECIMAL64_Bias; /* unbiased */ | |
261 | } | |
262 | ||
263 | /* get the coefficient */ | |
264 | sourhi&=0x0003ffff; /* clean coefficient continuation */ | |
265 | if (msd) { /* non-zero msd */ | |
266 | sourhi|=msd<<18; /* prefix to coefficient */ | |
267 | need=6; /* process 6 declets */ | |
268 | } | |
269 | else { /* msd=0 */ | |
270 | if (!sourhi) { /* top word 0 */ | |
271 | if (!sourlo) return dn; /* easy: coefficient is 0 */ | |
272 | need=3; /* process at least 3 declets */ | |
273 | if (sourlo&0xc0000000) need++; /* process 4 declets */ | |
274 | /* [could reduce some more, here] */ | |
275 | } | |
276 | else { /* some bits in top word, msd=0 */ | |
277 | need=4; /* process at least 4 declets */ | |
278 | if (sourhi&0x0003ff00) need++; /* top declet!=0, process 5 */ | |
279 | } | |
280 | } /*msd=0 */ | |
281 | ||
282 | decDigitsFromDPD(dn, sourar, need); /* process declets */ | |
283 | return dn; | |
284 | } /* decimal64ToNumber */ | |
285 | ||
286 | ||
287 | /* ------------------------------------------------------------------ */ | |
288 | /* to-scientific-string -- conversion to numeric string */ | |
289 | /* to-engineering-string -- conversion to numeric string */ | |
290 | /* */ | |
291 | /* decimal64ToString(d64, string); */ | |
292 | /* decimal64ToEngString(d64, string); */ | |
293 | /* */ | |
294 | /* d64 is the decimal64 format number to convert */ | |
295 | /* string is the string where the result will be laid out */ | |
296 | /* */ | |
297 | /* string must be at least 24 characters */ | |
298 | /* */ | |
299 | /* No error is possible, and no status can be set. */ | |
300 | /* ------------------------------------------------------------------ */ | |
301 | char * decimal64ToEngString(const decimal64 *d64, char *string){ | |
302 | decNumber dn; /* work */ | |
303 | decimal64ToNumber(d64, &dn); | |
304 | decNumberToEngString(&dn, string); | |
305 | return string; | |
306 | } /* decimal64ToEngString */ | |
307 | ||
308 | char * decimal64ToString(const decimal64 *d64, char *string){ | |
309 | uInt msd; /* coefficient MSD */ | |
310 | Int exp; /* exponent top two bits or full */ | |
311 | uInt comb; /* combination field */ | |
312 | char *cstart; /* coefficient start */ | |
313 | char *c; /* output pointer in string */ | |
314 | const uInt *pu; /* work */ | |
315 | char *s, *t; /* .. (source, target) */ | |
316 | Int dpd; /* .. */ | |
317 | Int pre, e; /* .. */ | |
318 | const uByte *u; /* .. */ | |
319 | ||
320 | uInt sourar[2]; /* source 64-bit */ | |
321 | #define sourhi sourar[1] /* name the word with the sign */ | |
322 | #define sourlo sourar[0] /* and the lower word */ | |
323 | ||
324 | /* load source from storage; this is endian */ | |
325 | pu=(const uInt *)d64->bytes; /* overlay */ | |
326 | if (DECLITEND) { | |
327 | sourlo=pu[0]; /* directly load the low int */ | |
328 | sourhi=pu[1]; /* then the high int */ | |
329 | } | |
330 | else { | |
331 | sourhi=pu[0]; /* directly load the high int */ | |
332 | sourlo=pu[1]; /* then the low int */ | |
333 | } | |
334 | ||
335 | c=string; /* where result will go */ | |
336 | if (((Int)sourhi)<0) *c++='-'; /* handle sign */ | |
337 | ||
338 | comb=(sourhi>>26)&0x1f; /* combination field */ | |
339 | msd=COMBMSD[comb]; /* decode the combination field */ | |
340 | exp=COMBEXP[comb]; /* .. */ | |
341 | ||
342 | if (exp==3) { | |
343 | if (msd==0) { /* infinity */ | |
344 | strcpy(c, "Inf"); | |
345 | strcpy(c+3, "inity"); | |
346 | return string; /* easy */ | |
347 | } | |
348 | if (sourhi&0x02000000) *c++='s'; /* sNaN */ | |
349 | strcpy(c, "NaN"); /* complete word */ | |
350 | c+=3; /* step past */ | |
351 | if (sourlo==0 && (sourhi&0x0003ffff)==0) return string; /* zero payload */ | |
352 | /* otherwise drop through to add integer; set correct exp */ | |
353 | exp=0; msd=0; /* setup for following code */ | |
354 | } | |
355 | else exp=(exp<<8)+((sourhi>>18)&0xff)-DECIMAL64_Bias; | |
356 | ||
357 | /* convert 16 digits of significand to characters */ | |
358 | cstart=c; /* save start of coefficient */ | |
359 | if (msd) *c++='0'+(char)msd; /* non-zero most significant digit */ | |
360 | ||
361 | /* Now decode the declets. After extracting each one, it is */ | |
362 | /* decoded to binary and then to a 4-char sequence by table lookup; */ | |
363 | /* the 4-chars are a 1-char length (significant digits, except 000 */ | |
364 | /* has length 0). This allows us to left-align the first declet */ | |
365 | /* with non-zero content, then remaining ones are full 3-char */ | |
366 | /* length. We use fixed-length memcpys because variable-length */ | |
367 | /* causes a subroutine call in GCC. (These are length 4 for speed */ | |
368 | /* and are safe because the array has an extra terminator byte.) */ | |
369 | #define dpd2char u=&BIN2CHAR[DPD2BIN[dpd]*4]; \ | |
370 | if (c!=cstart) {memcpy(c, u+1, 4); c+=3;} \ | |
371 | else if (*u) {memcpy(c, u+4-*u, 4); c+=*u;} | |
372 | ||
373 | dpd=(sourhi>>8)&0x3ff; /* declet 1 */ | |
374 | dpd2char; | |
375 | dpd=((sourhi&0xff)<<2) | (sourlo>>30); /* declet 2 */ | |
376 | dpd2char; | |
377 | dpd=(sourlo>>20)&0x3ff; /* declet 3 */ | |
378 | dpd2char; | |
379 | dpd=(sourlo>>10)&0x3ff; /* declet 4 */ | |
380 | dpd2char; | |
381 | dpd=(sourlo)&0x3ff; /* declet 5 */ | |
382 | dpd2char; | |
383 | ||
384 | if (c==cstart) *c++='0'; /* all zeros -- make 0 */ | |
385 | ||
386 | if (exp==0) { /* integer or NaN case -- easy */ | |
387 | *c='\0'; /* terminate */ | |
388 | return string; | |
389 | } | |
390 | ||
391 | /* non-0 exponent */ | |
392 | e=0; /* assume no E */ | |
393 | pre=c-cstart+exp; | |
394 | /* [here, pre-exp is the digits count (==1 for zero)] */ | |
395 | if (exp>0 || pre<-5) { /* need exponential form */ | |
396 | e=pre-1; /* calculate E value */ | |
397 | pre=1; /* assume one digit before '.' */ | |
398 | } /* exponential form */ | |
399 | ||
400 | /* modify the coefficient, adding 0s, '.', and E+nn as needed */ | |
401 | s=c-1; /* source (LSD) */ | |
402 | if (pre>0) { /* ddd.ddd (plain), perhaps with E */ | |
403 | char *dotat=cstart+pre; | |
404 | if (dotat<c) { /* if embedded dot needed... */ | |
405 | t=c; /* target */ | |
406 | for (; s>=dotat; s--, t--) *t=*s; /* open the gap; leave t at gap */ | |
407 | *t='.'; /* insert the dot */ | |
408 | c++; /* length increased by one */ | |
409 | } | |
410 | ||
411 | /* finally add the E-part, if needed; it will never be 0, and has */ | |
412 | /* a maximum length of 3 digits */ | |
413 | if (e!=0) { | |
414 | *c++='E'; /* starts with E */ | |
415 | *c++='+'; /* assume positive */ | |
416 | if (e<0) { | |
417 | *(c-1)='-'; /* oops, need '-' */ | |
418 | e=-e; /* uInt, please */ | |
419 | } | |
420 | u=&BIN2CHAR[e*4]; /* -> length byte */ | |
421 | memcpy(c, u+4-*u, 4); /* copy fixed 4 characters [is safe] */ | |
422 | c+=*u; /* bump pointer appropriately */ | |
423 | } | |
424 | *c='\0'; /* add terminator */ | |
425 | /*printf("res %s\n", string); */ | |
426 | return string; | |
427 | } /* pre>0 */ | |
428 | ||
429 | /* -5<=pre<=0: here for plain 0.ddd or 0.000ddd forms (can never have E) */ | |
430 | t=c+1-pre; | |
431 | *(t+1)='\0'; /* can add terminator now */ | |
432 | for (; s>=cstart; s--, t--) *t=*s; /* shift whole coefficient right */ | |
433 | c=cstart; | |
434 | *c++='0'; /* always starts with 0. */ | |
435 | *c++='.'; | |
436 | for (; pre<0; pre++) *c++='0'; /* add any 0's after '.' */ | |
437 | /*printf("res %s\n", string); */ | |
438 | return string; | |
439 | } /* decimal64ToString */ | |
440 | ||
441 | /* ------------------------------------------------------------------ */ | |
442 | /* to-number -- conversion from numeric string */ | |
443 | /* */ | |
444 | /* decimal64FromString(result, string, set); */ | |
445 | /* */ | |
446 | /* result is the decimal64 format number which gets the result of */ | |
447 | /* the conversion */ | |
448 | /* *string is the character string which should contain a valid */ | |
449 | /* number (which may be a special value) */ | |
450 | /* set is the context */ | |
451 | /* */ | |
452 | /* The context is supplied to this routine is used for error handling */ | |
453 | /* (setting of status and traps) and for the rounding mode, only. */ | |
454 | /* If an error occurs, the result will be a valid decimal64 NaN. */ | |
455 | /* ------------------------------------------------------------------ */ | |
456 | decimal64 * decimal64FromString(decimal64 *result, const char *string, | |
457 | decContext *set) { | |
458 | decContext dc; /* work */ | |
459 | decNumber dn; /* .. */ | |
460 | ||
461 | decContextDefault(&dc, DEC_INIT_DECIMAL64); /* no traps, please */ | |
462 | dc.round=set->round; /* use supplied rounding */ | |
463 | ||
464 | decNumberFromString(&dn, string, &dc); /* will round if needed */ | |
465 | ||
466 | decimal64FromNumber(result, &dn, &dc); | |
467 | if (dc.status!=0) { /* something happened */ | |
468 | decContextSetStatus(set, dc.status); /* .. pass it on */ | |
469 | } | |
470 | return result; | |
471 | } /* decimal64FromString */ | |
472 | ||
473 | /* ------------------------------------------------------------------ */ | |
474 | /* decimal64IsCanonical -- test whether encoding is canonical */ | |
475 | /* d64 is the source decimal64 */ | |
476 | /* returns 1 if the encoding of d64 is canonical, 0 otherwise */ | |
477 | /* No error is possible. */ | |
478 | /* ------------------------------------------------------------------ */ | |
479 | uint32_t decimal64IsCanonical(const decimal64 *d64) { | |
480 | decNumber dn; /* work */ | |
481 | decimal64 canon; /* .. */ | |
482 | decContext dc; /* .. */ | |
483 | decContextDefault(&dc, DEC_INIT_DECIMAL64); | |
484 | decimal64ToNumber(d64, &dn); | |
485 | decimal64FromNumber(&canon, &dn, &dc);/* canon will now be canonical */ | |
486 | return memcmp(d64, &canon, DECIMAL64_Bytes)==0; | |
487 | } /* decimal64IsCanonical */ | |
488 | ||
489 | /* ------------------------------------------------------------------ */ | |
490 | /* decimal64Canonical -- copy an encoding, ensuring it is canonical */ | |
491 | /* d64 is the source decimal64 */ | |
492 | /* result is the target (may be the same decimal64) */ | |
493 | /* returns result */ | |
494 | /* No error is possible. */ | |
495 | /* ------------------------------------------------------------------ */ | |
496 | decimal64 * decimal64Canonical(decimal64 *result, const decimal64 *d64) { | |
497 | decNumber dn; /* work */ | |
498 | decContext dc; /* .. */ | |
499 | decContextDefault(&dc, DEC_INIT_DECIMAL64); | |
500 | decimal64ToNumber(d64, &dn); | |
501 | decimal64FromNumber(result, &dn, &dc);/* result will now be canonical */ | |
502 | return result; | |
503 | } /* decimal64Canonical */ | |
504 | ||
505 | #if DECTRACE || DECCHECK | |
506 | /* Macros for accessing decimal64 fields. These assume the | |
507 | argument is a reference (pointer) to the decimal64 structure, | |
508 | and the decimal64 is in network byte order (big-endian) */ | |
509 | /* Get sign */ | |
510 | #define decimal64Sign(d) ((unsigned)(d)->bytes[0]>>7) | |
511 | ||
512 | /* Get combination field */ | |
513 | #define decimal64Comb(d) (((d)->bytes[0] & 0x7c)>>2) | |
514 | ||
515 | /* Get exponent continuation [does not remove bias] */ | |
516 | #define decimal64ExpCon(d) ((((d)->bytes[0] & 0x03)<<6) \ | |
517 | | ((unsigned)(d)->bytes[1]>>2)) | |
518 | ||
519 | /* Set sign [this assumes sign previously 0] */ | |
520 | #define decimal64SetSign(d, b) { \ | |
521 | (d)->bytes[0]|=((unsigned)(b)<<7);} | |
522 | ||
523 | /* Set exponent continuation [does not apply bias] */ | |
524 | /* This assumes range has been checked and exponent previously 0; */ | |
525 | /* type of exponent must be unsigned */ | |
526 | #define decimal64SetExpCon(d, e) { \ | |
527 | (d)->bytes[0]|=(uint8_t)((e)>>6); \ | |
528 | (d)->bytes[1]|=(uint8_t)(((e)&0x3F)<<2);} | |
529 | ||
530 | /* ------------------------------------------------------------------ */ | |
531 | /* decimal64Show -- display a decimal64 in hexadecimal [debug aid] */ | |
532 | /* d64 -- the number to show */ | |
533 | /* ------------------------------------------------------------------ */ | |
534 | /* Also shows sign/cob/expconfields extracted */ | |
535 | void decimal64Show(const decimal64 *d64) { | |
536 | char buf[DECIMAL64_Bytes*2+1]; | |
537 | Int i, j=0; | |
538 | ||
539 | if (DECLITEND) { | |
540 | for (i=0; i<DECIMAL64_Bytes; i++, j+=2) { | |
541 | sprintf(&buf[j], "%02x", d64->bytes[7-i]); | |
542 | } | |
543 | printf(" D64> %s [S:%d Cb:%02x Ec:%02x] LittleEndian\n", buf, | |
544 | d64->bytes[7]>>7, (d64->bytes[7]>>2)&0x1f, | |
545 | ((d64->bytes[7]&0x3)<<6)| (d64->bytes[6]>>2)); | |
546 | } | |
547 | else { /* big-endian */ | |
548 | for (i=0; i<DECIMAL64_Bytes; i++, j+=2) { | |
549 | sprintf(&buf[j], "%02x", d64->bytes[i]); | |
550 | } | |
551 | printf(" D64> %s [S:%d Cb:%02x Ec:%02x] BigEndian\n", buf, | |
552 | decimal64Sign(d64), decimal64Comb(d64), decimal64ExpCon(d64)); | |
553 | } | |
554 | } /* decimal64Show */ | |
555 | #endif | |
556 | ||
557 | /* ================================================================== */ | |
558 | /* Shared utility routines and tables */ | |
559 | /* ================================================================== */ | |
560 | /* define and include the conversion tables to use for shared code */ | |
561 | #if DECDPUN==3 | |
562 | #define DEC_DPD2BIN 1 | |
563 | #else | |
564 | #define DEC_DPD2BCD 1 | |
565 | #endif | |
566 | #include "decDPD.h" /* lookup tables */ | |
567 | ||
568 | /* The maximum number of decNumberUnits needed for a working copy of */ | |
569 | /* the units array is the ceiling of digits/DECDPUN, where digits is */ | |
570 | /* the maximum number of digits in any of the formats for which this */ | |
571 | /* is used. decimal128.h must not be included in this module, so, as */ | |
572 | /* a very special case, that number is defined as a literal here. */ | |
573 | #define DECMAX754 34 | |
574 | #define DECMAXUNITS ((DECMAX754+DECDPUN-1)/DECDPUN) | |
575 | ||
576 | /* ------------------------------------------------------------------ */ | |
577 | /* Combination field lookup tables (uInts to save measurable work) */ | |
578 | /* */ | |
579 | /* COMBEXP - 2-bit most-significant-bits of exponent */ | |
580 | /* [11 if an Infinity or NaN] */ | |
581 | /* COMBMSD - 4-bit most-significant-digit */ | |
582 | /* [0=Infinity, 1=NaN if COMBEXP=11] */ | |
583 | /* */ | |
584 | /* Both are indexed by the 5-bit combination field (0-31) */ | |
585 | /* ------------------------------------------------------------------ */ | |
586 | const uInt COMBEXP[32]={0, 0, 0, 0, 0, 0, 0, 0, | |
587 | 1, 1, 1, 1, 1, 1, 1, 1, | |
588 | 2, 2, 2, 2, 2, 2, 2, 2, | |
589 | 0, 0, 1, 1, 2, 2, 3, 3}; | |
590 | const uInt COMBMSD[32]={0, 1, 2, 3, 4, 5, 6, 7, | |
591 | 0, 1, 2, 3, 4, 5, 6, 7, | |
592 | 0, 1, 2, 3, 4, 5, 6, 7, | |
593 | 8, 9, 8, 9, 8, 9, 0, 1}; | |
594 | ||
595 | /* ------------------------------------------------------------------ */ | |
596 | /* decDigitsToDPD -- pack coefficient into DPD form */ | |
597 | /* */ | |
598 | /* dn is the source number (assumed valid, max DECMAX754 digits) */ | |
599 | /* targ is 1, 2, or 4-element uInt array, which the caller must */ | |
600 | /* have cleared to zeros */ | |
601 | /* shift is the number of 0 digits to add on the right (normally 0) */ | |
602 | /* */ | |
603 | /* The coefficient must be known small enough to fit. The full */ | |
604 | /* coefficient is copied, including the leading 'odd' digit. This */ | |
605 | /* digit is retrieved and packed into the combination field by the */ | |
606 | /* caller. */ | |
607 | /* */ | |
608 | /* The target uInts are altered only as necessary to receive the */ | |
609 | /* digits of the decNumber. When more than one uInt is needed, they */ | |
610 | /* are filled from left to right (that is, the uInt at offset 0 will */ | |
611 | /* end up with the least-significant digits). */ | |
612 | /* */ | |
613 | /* shift is used for 'fold-down' padding. */ | |
614 | /* */ | |
615 | /* No error is possible. */ | |
616 | /* ------------------------------------------------------------------ */ | |
617 | #if DECDPUN<=4 | |
618 | /* Constant multipliers for divide-by-power-of five using reciprocal */ | |
619 | /* multiply, after removing powers of 2 by shifting, and final shift */ | |
620 | /* of 17 [we only need up to **4] */ | |
621 | static const uInt multies[]={131073, 26215, 5243, 1049, 210}; | |
622 | /* QUOT10 -- macro to return the quotient of unit u divided by 10**n */ | |
623 | #define QUOT10(u, n) ((((uInt)(u)>>(n))*multies[n])>>17) | |
624 | #endif | |
625 | void decDigitsToDPD(const decNumber *dn, uInt *targ, Int shift) { | |
626 | Int cut; /* work */ | |
627 | Int n; /* output bunch counter */ | |
628 | Int digits=dn->digits; /* digit countdown */ | |
629 | uInt dpd; /* densely packed decimal value */ | |
630 | uInt bin; /* binary value 0-999 */ | |
631 | uInt *uout=targ; /* -> current output uInt */ | |
632 | uInt uoff=0; /* -> current output offset [from right] */ | |
633 | const Unit *inu=dn->lsu; /* -> current input unit */ | |
634 | Unit uar[DECMAXUNITS]; /* working copy of units, iff shifted */ | |
635 | #if DECDPUN!=3 /* not fast path */ | |
636 | Unit in; /* current unit */ | |
637 | #endif | |
638 | ||
639 | if (shift!=0) { /* shift towards most significant required */ | |
640 | /* shift the units array to the left by pad digits and copy */ | |
641 | /* [this code is a special case of decShiftToMost, which could */ | |
642 | /* be used instead if exposed and the array were copied first] */ | |
643 | const Unit *source; /* .. */ | |
644 | Unit *target, *first; /* .. */ | |
645 | uInt next=0; /* work */ | |
646 | ||
647 | source=dn->lsu+D2U(digits)-1; /* where msu comes from */ | |
648 | target=uar+D2U(digits)-1+D2U(shift);/* where upper part of first cut goes */ | |
649 | cut=DECDPUN-MSUDIGITS(shift); /* where to slice */ | |
650 | if (cut==0) { /* unit-boundary case */ | |
651 | for (; source>=dn->lsu; source--, target--) *target=*source; | |
652 | } | |
653 | else { | |
654 | first=uar+D2U(digits+shift)-1; /* where msu will end up */ | |
655 | for (; source>=dn->lsu; source--, target--) { | |
656 | /* split the source Unit and accumulate remainder for next */ | |
657 | #if DECDPUN<=4 | |
658 | uInt quot=QUOT10(*source, cut); | |
659 | uInt rem=*source-quot*DECPOWERS[cut]; | |
660 | next+=quot; | |
661 | #else | |
662 | uInt rem=*source%DECPOWERS[cut]; | |
663 | next+=*source/DECPOWERS[cut]; | |
664 | #endif | |
665 | if (target<=first) *target=(Unit)next; /* write to target iff valid */ | |
666 | next=rem*DECPOWERS[DECDPUN-cut]; /* save remainder for next Unit */ | |
667 | } | |
668 | } /* shift-move */ | |
669 | /* propagate remainder to one below and clear the rest */ | |
670 | for (; target>=uar; target--) { | |
671 | *target=(Unit)next; | |
672 | next=0; | |
673 | } | |
674 | digits+=shift; /* add count (shift) of zeros added */ | |
675 | inu=uar; /* use units in working array */ | |
676 | } | |
677 | ||
678 | /* now densely pack the coefficient into DPD declets */ | |
679 | ||
680 | #if DECDPUN!=3 /* not fast path */ | |
681 | in=*inu; /* current unit */ | |
682 | cut=0; /* at lowest digit */ | |
683 | bin=0; /* [keep compiler quiet] */ | |
684 | #endif | |
685 | ||
686 | for(n=0; digits>0; n++) { /* each output bunch */ | |
687 | #if DECDPUN==3 /* fast path, 3-at-a-time */ | |
688 | bin=*inu; /* 3 digits ready for convert */ | |
689 | digits-=3; /* [may go negative] */ | |
690 | inu++; /* may need another */ | |
691 | ||
692 | #else /* must collect digit-by-digit */ | |
693 | Unit dig; /* current digit */ | |
694 | Int j; /* digit-in-declet count */ | |
695 | for (j=0; j<3; j++) { | |
696 | #if DECDPUN<=4 | |
697 | Unit temp=(Unit)((uInt)(in*6554)>>16); | |
698 | dig=(Unit)(in-X10(temp)); | |
699 | in=temp; | |
700 | #else | |
701 | dig=in%10; | |
702 | in=in/10; | |
703 | #endif | |
704 | if (j==0) bin=dig; | |
705 | else if (j==1) bin+=X10(dig); | |
706 | else /* j==2 */ bin+=X100(dig); | |
707 | digits--; | |
708 | if (digits==0) break; /* [also protects *inu below] */ | |
709 | cut++; | |
710 | if (cut==DECDPUN) {inu++; in=*inu; cut=0;} | |
711 | } | |
712 | #endif | |
713 | /* here there are 3 digits in bin, or have used all input digits */ | |
714 | ||
715 | dpd=BIN2DPD[bin]; | |
716 | ||
717 | /* write declet to uInt array */ | |
718 | *uout|=dpd<<uoff; | |
719 | uoff+=10; | |
720 | if (uoff<32) continue; /* no uInt boundary cross */ | |
721 | uout++; | |
722 | uoff-=32; | |
723 | *uout|=dpd>>(10-uoff); /* collect top bits */ | |
724 | } /* n declets */ | |
725 | return; | |
726 | } /* decDigitsToDPD */ | |
727 | ||
728 | /* ------------------------------------------------------------------ */ | |
729 | /* decDigitsFromDPD -- unpack a format's coefficient */ | |
730 | /* */ | |
731 | /* dn is the target number, with 7, 16, or 34-digit space. */ | |
732 | /* sour is a 1, 2, or 4-element uInt array containing only declets */ | |
733 | /* declets is the number of (right-aligned) declets in sour to */ | |
734 | /* be processed. This may be 1 more than the obvious number in */ | |
735 | /* a format, as any top digit is prefixed to the coefficient */ | |
736 | /* continuation field. It also may be as small as 1, as the */ | |
737 | /* caller may pre-process leading zero declets. */ | |
738 | /* */ | |
739 | /* When doing the 'extra declet' case care is taken to avoid writing */ | |
740 | /* extra digits when there are leading zeros, as these could overflow */ | |
741 | /* the units array when DECDPUN is not 3. */ | |
742 | /* */ | |
743 | /* The target uInts are used only as necessary to process declets */ | |
744 | /* declets into the decNumber. When more than one uInt is needed, */ | |
745 | /* they are used from left to right (that is, the uInt at offset 0 */ | |
746 | /* provides the least-significant digits). */ | |
747 | /* */ | |
748 | /* dn->digits is set, but not the sign or exponent. */ | |
749 | /* No error is possible [the redundant 888 codes are allowed]. */ | |
750 | /* ------------------------------------------------------------------ */ | |
751 | void decDigitsFromDPD(decNumber *dn, const uInt *sour, Int declets) { | |
752 | ||
753 | uInt dpd; /* collector for 10 bits */ | |
754 | Int n; /* counter */ | |
755 | Unit *uout=dn->lsu; /* -> current output unit */ | |
756 | Unit *last=uout; /* will be unit containing msd */ | |
757 | const uInt *uin=sour; /* -> current input uInt */ | |
758 | uInt uoff=0; /* -> current input offset [from right] */ | |
759 | ||
760 | #if DECDPUN!=3 | |
761 | uInt bcd; /* BCD result */ | |
762 | uInt nibble; /* work */ | |
763 | Unit out=0; /* accumulator */ | |
764 | Int cut=0; /* power of ten in current unit */ | |
765 | #endif | |
766 | #if DECDPUN>4 | |
767 | uInt const *pow; /* work */ | |
768 | #endif | |
769 | ||
770 | /* Expand the densely-packed integer, right to left */ | |
771 | for (n=declets-1; n>=0; n--) { /* count down declets of 10 bits */ | |
772 | dpd=*uin>>uoff; | |
773 | uoff+=10; | |
774 | if (uoff>32) { /* crossed uInt boundary */ | |
775 | uin++; | |
776 | uoff-=32; | |
777 | dpd|=*uin<<(10-uoff); /* get waiting bits */ | |
778 | } | |
779 | dpd&=0x3ff; /* clear uninteresting bits */ | |
780 | ||
781 | #if DECDPUN==3 | |
782 | if (dpd==0) *uout=0; | |
783 | else { | |
784 | *uout=DPD2BIN[dpd]; /* convert 10 bits to binary 0-999 */ | |
785 | last=uout; /* record most significant unit */ | |
786 | } | |
787 | uout++; | |
788 | } /* n */ | |
789 | ||
790 | #else /* DECDPUN!=3 */ | |
791 | if (dpd==0) { /* fastpath [e.g., leading zeros] */ | |
792 | /* write out three 0 digits (nibbles); out may have digit(s) */ | |
793 | cut++; | |
794 | if (cut==DECDPUN) {*uout=out; if (out) {last=uout; out=0;} uout++; cut=0;} | |
795 | if (n==0) break; /* [as below, works even if MSD=0] */ | |
796 | cut++; | |
797 | if (cut==DECDPUN) {*uout=out; if (out) {last=uout; out=0;} uout++; cut=0;} | |
798 | cut++; | |
799 | if (cut==DECDPUN) {*uout=out; if (out) {last=uout; out=0;} uout++; cut=0;} | |
800 | continue; | |
801 | } | |
802 | ||
803 | bcd=DPD2BCD[dpd]; /* convert 10 bits to 12 bits BCD */ | |
804 | ||
805 | /* now accumulate the 3 BCD nibbles into units */ | |
806 | nibble=bcd & 0x00f; | |
807 | if (nibble) out=(Unit)(out+nibble*DECPOWERS[cut]); | |
808 | cut++; | |
809 | if (cut==DECDPUN) {*uout=out; if (out) {last=uout; out=0;} uout++; cut=0;} | |
810 | bcd>>=4; | |
811 | ||
812 | /* if this is the last declet and the remaining nibbles in bcd */ | |
813 | /* are 00 then process no more nibbles, because this could be */ | |
814 | /* the 'odd' MSD declet and writing any more Units would then */ | |
815 | /* overflow the unit array */ | |
816 | if (n==0 && !bcd) break; | |
817 | ||
818 | nibble=bcd & 0x00f; | |
819 | if (nibble) out=(Unit)(out+nibble*DECPOWERS[cut]); | |
820 | cut++; | |
821 | if (cut==DECDPUN) {*uout=out; if (out) {last=uout; out=0;} uout++; cut=0;} | |
822 | bcd>>=4; | |
823 | ||
824 | nibble=bcd & 0x00f; | |
825 | if (nibble) out=(Unit)(out+nibble*DECPOWERS[cut]); | |
826 | cut++; | |
827 | if (cut==DECDPUN) {*uout=out; if (out) {last=uout; out=0;} uout++; cut=0;} | |
828 | } /* n */ | |
829 | if (cut!=0) { /* some more left over */ | |
830 | *uout=out; /* write out final unit */ | |
831 | if (out) last=uout; /* and note if non-zero */ | |
832 | } | |
833 | #endif | |
834 | ||
835 | /* here, last points to the most significant unit with digits; */ | |
836 | /* inspect it to get the final digits count -- this is essentially */ | |
837 | /* the same code as decGetDigits in decNumber.c */ | |
838 | dn->digits=(last-dn->lsu)*DECDPUN+1; /* floor of digits, plus */ | |
839 | /* must be at least 1 digit */ | |
840 | #if DECDPUN>1 | |
841 | if (*last<10) return; /* common odd digit or 0 */ | |
842 | dn->digits++; /* must be 2 at least */ | |
843 | #if DECDPUN>2 | |
844 | if (*last<100) return; /* 10-99 */ | |
845 | dn->digits++; /* must be 3 at least */ | |
846 | #if DECDPUN>3 | |
847 | if (*last<1000) return; /* 100-999 */ | |
848 | dn->digits++; /* must be 4 at least */ | |
849 | #if DECDPUN>4 | |
850 | for (pow=&DECPOWERS[4]; *last>=*pow; pow++) dn->digits++; | |
851 | #endif | |
852 | #endif | |
853 | #endif | |
854 | #endif | |
855 | return; | |
856 | } /*decDigitsFromDPD */ |