1 | /* Decimal 128-bit format module for the decNumber C Library. |
2 | Copyright (C) 2005-2024 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 3, or (at your option) any later |
10 | version. |
11 | |
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
15 | for more details. |
16 | |
17 | Under Section 7 of GPL version 3, you are granted additional |
18 | permissions described in the GCC Runtime Library Exception, version |
19 | 3.1, as published by the Free Software Foundation. |
20 | |
21 | You should have received a copy of the GNU General Public License and |
22 | a copy of the GCC Runtime Library Exception along with this program; |
23 | see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
24 | <http://www.gnu.org/licenses/>. */ |
25 | |
26 | /* ------------------------------------------------------------------ */ |
27 | /* Decimal 128-bit format module */ |
28 | /* ------------------------------------------------------------------ */ |
29 | /* This module comprises the routines for decimal128 format numbers. */ |
30 | /* Conversions are supplied to and from decNumber and String. */ |
31 | /* */ |
32 | /* This is used when decNumber provides operations, either for all */ |
33 | /* operations or as a proxy between decNumber and decSingle. */ |
34 | /* */ |
35 | /* Error handling is the same as decNumber (qv.). */ |
36 | /* ------------------------------------------------------------------ */ |
37 | #include <string.h> /* [for memset/memcpy] */ |
38 | #include <stdio.h> /* [for printf] */ |
39 | |
40 | #include "dconfig.h" /* GCC definitions */ |
41 | #define DECNUMDIGITS 34 /* make decNumbers with space for 34 */ |
42 | #include "decNumber.h" /* base number library */ |
43 | #include "decNumberLocal.h" /* decNumber local types, etc. */ |
44 | #include "decimal128.h" /* our primary include */ |
45 | |
46 | /* Utility routines and tables [in decimal64.c] */ |
47 | extern const uInt COMBEXP[32], COMBMSD[32]; |
48 | extern const uShort DPD2BIN[1024]; |
49 | extern const uShort BIN2DPD[1000]; /* [not used] */ |
50 | extern const uByte BIN2CHAR[4001]; |
51 | |
52 | extern void decDigitsFromDPD(decNumber *, const uInt *, Int); |
53 | extern void decDigitsToDPD(const decNumber *, uInt *, Int); |
54 | |
55 | #if DECTRACE || DECCHECK |
56 | void decimal128Show(const decimal128 *); /* for debug */ |
57 | extern void decNumberShow(const decNumber *); /* .. */ |
58 | #endif |
59 | |
60 | /* Useful macro */ |
61 | /* Clear a structure (e.g., a decNumber) */ |
62 | #define DEC_clear(d) memset(d, 0, sizeof(*d)) |
63 | |
64 | /* ------------------------------------------------------------------ */ |
65 | /* decimal128FromNumber -- convert decNumber to decimal128 */ |
66 | /* */ |
67 | /* ds is the target decimal128 */ |
68 | /* dn is the source number (assumed valid) */ |
69 | /* set is the context, used only for reporting errors */ |
70 | /* */ |
71 | /* The set argument is used only for status reporting and for the */ |
72 | /* rounding mode (used if the coefficient is more than DECIMAL128_Pmax*/ |
73 | /* digits or an overflow is detected). If the exponent is out of the */ |
74 | /* valid range then Overflow or Underflow will be raised. */ |
75 | /* After Underflow a subnormal result is possible. */ |
76 | /* */ |
77 | /* DEC_Clamped is set if the number has to be 'folded down' to fit, */ |
78 | /* by reducing its exponent and multiplying the coefficient by a */ |
79 | /* power of ten, or if the exponent on a zero had to be clamped. */ |
80 | /* ------------------------------------------------------------------ */ |
81 | decimal128 * decimal128FromNumber(decimal128 *d128, const decNumber *dn, |
82 | decContext *set) { |
83 | uInt status=0; /* status accumulator */ |
84 | Int ae; /* adjusted exponent */ |
85 | decNumber dw; /* work */ |
86 | decContext dc; /* .. */ |
87 | uInt comb, exp; /* .. */ |
88 | uInt uiwork; /* for macros */ |
89 | uInt targar[4]={0,0,0,0}; /* target 128-bit */ |
90 | #define targhi targar[3] /* name the word with the sign */ |
91 | #define targmh targar[2] /* name the words */ |
92 | #define targml targar[1] /* .. */ |
93 | #define targlo targar[0] /* .. */ |
94 | |
95 | /* If the number has too many digits, or the exponent could be */ |
96 | /* out of range then reduce the number under the appropriate */ |
97 | /* constraints. This could push the number to Infinity or zero, */ |
98 | /* so this check and rounding must be done before generating the */ |
99 | /* decimal128] */ |
100 | ae=dn->exponent+dn->digits-1; /* [0 if special] */ |
101 | if (dn->digits>DECIMAL128_Pmax /* too many digits */ |
102 | || ae>DECIMAL128_Emax /* likely overflow */ |
103 | || ae<DECIMAL128_Emin) { /* likely underflow */ |
104 | decContextDefault(&dc, DEC_INIT_DECIMAL128); /* [no traps] */ |
105 | dc.round=set->round; /* use supplied rounding */ |
106 | decNumberPlus(&dw, dn, &dc); /* (round and check) */ |
107 | /* [this changes -0 to 0, so enforce the sign...] */ |
108 | dw.bits|=dn->bits&DECNEG; |
109 | status=dc.status; /* save status */ |
110 | dn=&dw; /* use the work number */ |
111 | } /* maybe out of range */ |
112 | |
113 | if (dn->bits&DECSPECIAL) { /* a special value */ |
114 | if (dn->bits&DECINF) targhi=DECIMAL_Inf<<24; |
115 | else { /* sNaN or qNaN */ |
116 | if ((*dn->lsu!=0 || dn->digits>1) /* non-zero coefficient */ |
117 | && (dn->digits<DECIMAL128_Pmax)) { /* coefficient fits */ |
118 | decDigitsToDPD(dn, targar, 0); |
119 | } |
120 | if (dn->bits&DECNAN) targhi|=DECIMAL_NaN<<24; |
121 | else targhi|=DECIMAL_sNaN<<24; |
122 | } /* a NaN */ |
123 | } /* special */ |
124 | |
125 | else { /* is finite */ |
126 | if (decNumberIsZero(dn)) { /* is a zero */ |
127 | /* set and clamp exponent */ |
128 | if (dn->exponent<-DECIMAL128_Bias) { |
129 | exp=0; /* low clamp */ |
130 | status|=DEC_Clamped; |
131 | } |
132 | else { |
133 | exp=dn->exponent+DECIMAL128_Bias; /* bias exponent */ |
134 | if (exp>DECIMAL128_Ehigh) { /* top clamp */ |
135 | exp=DECIMAL128_Ehigh; |
136 | status|=DEC_Clamped; |
137 | } |
138 | } |
139 | comb=(exp>>9) & 0x18; /* msd=0, exp top 2 bits .. */ |
140 | } |
141 | else { /* non-zero finite number */ |
142 | uInt msd; /* work */ |
143 | Int pad=0; /* coefficient pad digits */ |
144 | |
145 | /* the dn is known to fit, but it may need to be padded */ |
146 | exp=(uInt)(dn->exponent+DECIMAL128_Bias); /* bias exponent */ |
147 | if (exp>DECIMAL128_Ehigh) { /* fold-down case */ |
148 | pad=exp-DECIMAL128_Ehigh; |
149 | exp=DECIMAL128_Ehigh; /* [to maximum] */ |
150 | status|=DEC_Clamped; |
151 | } |
152 | |
153 | /* [fastpath for common case is not a win, here] */ |
154 | decDigitsToDPD(dn, targar, pad); |
155 | /* save and clear the top digit */ |
156 | msd=targhi>>14; |
157 | targhi&=0x00003fff; |
158 | |
159 | /* create the combination field */ |
160 | if (msd>=8) comb=0x18 | ((exp>>11) & 0x06) | (msd & 0x01); |
161 | else comb=((exp>>9) & 0x18) | msd; |
162 | } |
163 | targhi|=comb<<26; /* add combination field .. */ |
164 | targhi|=(exp&0xfff)<<14; /* .. and exponent continuation */ |
165 | } /* finite */ |
166 | |
167 | if (dn->bits&DECNEG) targhi|=0x80000000; /* add sign bit */ |
168 | |
169 | /* now write to storage; this is endian */ |
170 | if (DECLITEND) { |
171 | /* lo -> hi */ |
172 | UBFROMUI(d128->bytes, targlo); |
173 | UBFROMUI(d128->bytes+4, targml); |
174 | UBFROMUI(d128->bytes+8, targmh); |
175 | UBFROMUI(d128->bytes+12, targhi); |
176 | } |
177 | else { |
178 | /* hi -> lo */ |
179 | UBFROMUI(d128->bytes, targhi); |
180 | UBFROMUI(d128->bytes+4, targmh); |
181 | UBFROMUI(d128->bytes+8, targml); |
182 | UBFROMUI(d128->bytes+12, targlo); |
183 | } |
184 | |
185 | if (status!=0) decContextSetStatus(set, status); /* pass on status */ |
186 | /* decimal128Show(d128); */ |
187 | return d128; |
188 | } /* decimal128FromNumber */ |
189 | |
190 | /* ------------------------------------------------------------------ */ |
191 | /* decimal128ToNumber -- convert decimal128 to decNumber */ |
192 | /* d128 is the source decimal128 */ |
193 | /* dn is the target number, with appropriate space */ |
194 | /* No error is possible. */ |
195 | /* ------------------------------------------------------------------ */ |
196 | decNumber * decimal128ToNumber(const decimal128 *d128, decNumber *dn) { |
197 | uInt msd; /* coefficient MSD */ |
198 | uInt exp; /* exponent top two bits */ |
199 | uInt comb; /* combination field */ |
200 | Int need; /* work */ |
201 | uInt uiwork; /* for macros */ |
202 | uInt sourar[4]; /* source 128-bit */ |
203 | #define sourhi sourar[3] /* name the word with the sign */ |
204 | #define sourmh sourar[2] /* and the mid-high word */ |
205 | #define sourml sourar[1] /* and the mod-low word */ |
206 | #define sourlo sourar[0] /* and the lowest word */ |
207 | |
208 | /* load source from storage; this is endian */ |
209 | if (DECLITEND) { |
210 | sourlo=UBTOUI(d128->bytes ); /* directly load the low int */ |
211 | sourml=UBTOUI(d128->bytes+4 ); /* then the mid-low */ |
212 | sourmh=UBTOUI(d128->bytes+8 ); /* then the mid-high */ |
213 | sourhi=UBTOUI(d128->bytes+12); /* then the high int */ |
214 | } |
215 | else { |
216 | sourhi=UBTOUI(d128->bytes ); /* directly load the high int */ |
217 | sourmh=UBTOUI(d128->bytes+4 ); /* then the mid-high */ |
218 | sourml=UBTOUI(d128->bytes+8 ); /* then the mid-low */ |
219 | sourlo=UBTOUI(d128->bytes+12); /* then the low int */ |
220 | } |
221 | |
222 | comb=(sourhi>>26)&0x1f; /* combination field */ |
223 | |
224 | decNumberZero(dn); /* clean number */ |
225 | if (sourhi&0x80000000) dn->bits=DECNEG; /* set sign if negative */ |
226 | |
227 | msd=COMBMSD[comb]; /* decode the combination field */ |
228 | exp=COMBEXP[comb]; /* .. */ |
229 | |
230 | if (exp==3) { /* is a special */ |
231 | if (msd==0) { |
232 | dn->bits|=DECINF; |
233 | return dn; /* no coefficient needed */ |
234 | } |
235 | else if (sourhi&0x02000000) dn->bits|=DECSNAN; |
236 | else dn->bits|=DECNAN; |
237 | msd=0; /* no top digit */ |
238 | } |
239 | else { /* is a finite number */ |
240 | dn->exponent=(exp<<12)+((sourhi>>14)&0xfff)-DECIMAL128_Bias; /* unbiased */ |
241 | } |
242 | |
243 | /* get the coefficient */ |
244 | sourhi&=0x00003fff; /* clean coefficient continuation */ |
245 | if (msd) { /* non-zero msd */ |
246 | sourhi|=msd<<14; /* prefix to coefficient */ |
247 | need=12; /* process 12 declets */ |
248 | } |
249 | else { /* msd=0 */ |
250 | if (sourhi) need=11; /* declets to process */ |
251 | else if (sourmh) need=10; |
252 | else if (sourml) need=7; |
253 | else if (sourlo) need=4; |
254 | else return dn; /* easy: coefficient is 0 */ |
255 | } /*msd=0 */ |
256 | |
257 | decDigitsFromDPD(dn, sourar, need); /* process declets */ |
258 | /* decNumberShow(dn); */ |
259 | return dn; |
260 | } /* decimal128ToNumber */ |
261 | |
262 | /* ------------------------------------------------------------------ */ |
263 | /* to-scientific-string -- conversion to numeric string */ |
264 | /* to-engineering-string -- conversion to numeric string */ |
265 | /* */ |
266 | /* decimal128ToString(d128, string); */ |
267 | /* decimal128ToEngString(d128, string); */ |
268 | /* */ |
269 | /* d128 is the decimal128 format number to convert */ |
270 | /* string is the string where the result will be laid out */ |
271 | /* */ |
272 | /* string must be at least 24 characters */ |
273 | /* */ |
274 | /* No error is possible, and no status can be set. */ |
275 | /* ------------------------------------------------------------------ */ |
276 | char * decimal128ToEngString(const decimal128 *d128, char *string){ |
277 | decNumber dn; /* work */ |
278 | decimal128ToNumber(d128, dn: &dn); |
279 | decNumberToEngString(&dn, string); |
280 | return string; |
281 | } /* decimal128ToEngString */ |
282 | |
283 | char * decimal128ToString(const decimal128 *d128, char *string){ |
284 | uInt msd; /* coefficient MSD */ |
285 | Int exp; /* exponent top two bits or full */ |
286 | uInt comb; /* combination field */ |
287 | char *cstart; /* coefficient start */ |
288 | char *c; /* output pointer in string */ |
289 | const uByte *u; /* work */ |
290 | char *s, *t; /* .. (source, target) */ |
291 | Int dpd; /* .. */ |
292 | Int pre, e; /* .. */ |
293 | uInt uiwork; /* for macros */ |
294 | |
295 | uInt sourar[4]; /* source 128-bit */ |
296 | #define sourhi sourar[3] /* name the word with the sign */ |
297 | #define sourmh sourar[2] /* and the mid-high word */ |
298 | #define sourml sourar[1] /* and the mod-low word */ |
299 | #define sourlo sourar[0] /* and the lowest word */ |
300 | |
301 | /* load source from storage; this is endian */ |
302 | if (DECLITEND) { |
303 | sourlo=UBTOUI(d128->bytes ); /* directly load the low int */ |
304 | sourml=UBTOUI(d128->bytes+4 ); /* then the mid-low */ |
305 | sourmh=UBTOUI(d128->bytes+8 ); /* then the mid-high */ |
306 | sourhi=UBTOUI(d128->bytes+12); /* then the high int */ |
307 | } |
308 | else { |
309 | sourhi=UBTOUI(d128->bytes ); /* directly load the high int */ |
310 | sourmh=UBTOUI(d128->bytes+4 ); /* then the mid-high */ |
311 | sourml=UBTOUI(d128->bytes+8 ); /* then the mid-low */ |
312 | sourlo=UBTOUI(d128->bytes+12); /* then the low int */ |
313 | } |
314 | |
315 | c=string; /* where result will go */ |
316 | if (((Int)sourhi)<0) *c++='-'; /* handle sign */ |
317 | |
318 | comb=(sourhi>>26)&0x1f; /* combination field */ |
319 | msd=COMBMSD[comb]; /* decode the combination field */ |
320 | exp=COMBEXP[comb]; /* .. */ |
321 | |
322 | if (exp==3) { |
323 | if (msd==0) { /* infinity */ |
324 | strcpy(dest: c, src: "Inf" ); |
325 | strcpy(dest: c+3, src: "inity" ); |
326 | return string; /* easy */ |
327 | } |
328 | if (sourhi&0x02000000) *c++='s'; /* sNaN */ |
329 | strcpy(dest: c, src: "NaN" ); /* complete word */ |
330 | c+=3; /* step past */ |
331 | if (sourlo==0 && sourml==0 && sourmh==0 |
332 | && (sourhi&0x0003ffff)==0) return string; /* zero payload */ |
333 | /* otherwise drop through to add integer; set correct exp */ |
334 | exp=0; msd=0; /* setup for following code */ |
335 | } |
336 | else exp=(exp<<12)+((sourhi>>14)&0xfff)-DECIMAL128_Bias; /* unbiased */ |
337 | |
338 | /* convert 34 digits of significand to characters */ |
339 | cstart=c; /* save start of coefficient */ |
340 | if (msd) *c++='0'+(char)msd; /* non-zero most significant digit */ |
341 | |
342 | /* Now decode the declets. After extracting each one, it is */ |
343 | /* decoded to binary and then to a 4-char sequence by table lookup; */ |
344 | /* the 4-chars are a 1-char length (significant digits, except 000 */ |
345 | /* has length 0). This allows us to left-align the first declet */ |
346 | /* with non-zero content, then remaining ones are full 3-char */ |
347 | /* length. We use fixed-length memcpys because variable-length */ |
348 | /* causes a subroutine call in GCC. (These are length 4 for speed */ |
349 | /* and are safe because the array has an extra terminator byte.) */ |
350 | #define dpd2char u=&BIN2CHAR[DPD2BIN[dpd]*4]; \ |
351 | if (c!=cstart) {memcpy(c, u+1, 4); c+=3;} \ |
352 | else if (*u) {memcpy(c, u+4-*u, 4); c+=*u;} |
353 | dpd=(sourhi>>4)&0x3ff; /* declet 1 */ |
354 | dpd2char; |
355 | dpd=((sourhi&0xf)<<6) | (sourmh>>26); /* declet 2 */ |
356 | dpd2char; |
357 | dpd=(sourmh>>16)&0x3ff; /* declet 3 */ |
358 | dpd2char; |
359 | dpd=(sourmh>>6)&0x3ff; /* declet 4 */ |
360 | dpd2char; |
361 | dpd=((sourmh&0x3f)<<4) | (sourml>>28); /* declet 5 */ |
362 | dpd2char; |
363 | dpd=(sourml>>18)&0x3ff; /* declet 6 */ |
364 | dpd2char; |
365 | dpd=(sourml>>8)&0x3ff; /* declet 7 */ |
366 | dpd2char; |
367 | dpd=((sourml&0xff)<<2) | (sourlo>>30); /* declet 8 */ |
368 | dpd2char; |
369 | dpd=(sourlo>>20)&0x3ff; /* declet 9 */ |
370 | dpd2char; |
371 | dpd=(sourlo>>10)&0x3ff; /* declet 10 */ |
372 | dpd2char; |
373 | dpd=(sourlo)&0x3ff; /* declet 11 */ |
374 | dpd2char; |
375 | |
376 | if (c==cstart) *c++='0'; /* all zeros -- make 0 */ |
377 | |
378 | if (exp==0) { /* integer or NaN case -- easy */ |
379 | *c='\0'; /* terminate */ |
380 | return string; |
381 | } |
382 | |
383 | /* non-0 exponent */ |
384 | e=0; /* assume no E */ |
385 | pre=c-cstart+exp; |
386 | /* [here, pre-exp is the digits count (==1 for zero)] */ |
387 | if (exp>0 || pre<-5) { /* need exponential form */ |
388 | e=pre-1; /* calculate E value */ |
389 | pre=1; /* assume one digit before '.' */ |
390 | } /* exponential form */ |
391 | |
392 | /* modify the coefficient, adding 0s, '.', and E+nn as needed */ |
393 | s=c-1; /* source (LSD) */ |
394 | if (pre>0) { /* ddd.ddd (plain), perhaps with E */ |
395 | char *dotat=cstart+pre; |
396 | if (dotat<c) { /* if embedded dot needed... */ |
397 | t=c; /* target */ |
398 | for (; s>=dotat; s--, t--) *t=*s; /* open the gap; leave t at gap */ |
399 | *t='.'; /* insert the dot */ |
400 | c++; /* length increased by one */ |
401 | } |
402 | |
403 | /* finally add the E-part, if needed; it will never be 0, and has */ |
404 | /* a maximum length of 4 digits */ |
405 | if (e!=0) { |
406 | *c++='E'; /* starts with E */ |
407 | *c++='+'; /* assume positive */ |
408 | if (e<0) { |
409 | *(c-1)='-'; /* oops, need '-' */ |
410 | e=-e; /* uInt, please */ |
411 | } |
412 | if (e<1000) { /* 3 (or fewer) digits case */ |
413 | u=&BIN2CHAR[e*4]; /* -> length byte */ |
414 | memcpy(dest: c, src: u+4-*u, n: 4); /* copy fixed 4 characters [is safe] */ |
415 | c+=*u; /* bump pointer appropriately */ |
416 | } |
417 | else { /* 4-digits */ |
418 | Int thou=((e>>3)*1049)>>17; /* e/1000 */ |
419 | Int rem=e-(1000*thou); /* e%1000 */ |
420 | *c++='0'+(char)thou; |
421 | u=&BIN2CHAR[rem*4]; /* -> length byte */ |
422 | memcpy(dest: c, src: u+1, n: 4); /* copy fixed 3+1 characters [is safe] */ |
423 | c+=3; /* bump pointer, always 3 digits */ |
424 | } |
425 | } |
426 | *c='\0'; /* add terminator */ |
427 | /*printf("res %s\n", string); */ |
428 | return string; |
429 | } /* pre>0 */ |
430 | |
431 | /* -5<=pre<=0: here for plain 0.ddd or 0.000ddd forms (can never have E) */ |
432 | t=c+1-pre; |
433 | *(t+1)='\0'; /* can add terminator now */ |
434 | for (; s>=cstart; s--, t--) *t=*s; /* shift whole coefficient right */ |
435 | c=cstart; |
436 | *c++='0'; /* always starts with 0. */ |
437 | *c++='.'; |
438 | for (; pre<0; pre++) *c++='0'; /* add any 0's after '.' */ |
439 | /*printf("res %s\n", string); */ |
440 | return string; |
441 | } /* decimal128ToString */ |
442 | |
443 | /* ------------------------------------------------------------------ */ |
444 | /* to-number -- conversion from numeric string */ |
445 | /* */ |
446 | /* decimal128FromString(result, string, set); */ |
447 | /* */ |
448 | /* result is the decimal128 format number which gets the result of */ |
449 | /* the conversion */ |
450 | /* *string is the character string which should contain a valid */ |
451 | /* number (which may be a special value) */ |
452 | /* set is the context */ |
453 | /* */ |
454 | /* The context is supplied to this routine is used for error handling */ |
455 | /* (setting of status and traps) and for the rounding mode, only. */ |
456 | /* If an error occurs, the result will be a valid decimal128 NaN. */ |
457 | /* ------------------------------------------------------------------ */ |
458 | decimal128 * decimal128FromString(decimal128 *result, const char *string, |
459 | decContext *set) { |
460 | decContext dc; /* work */ |
461 | decNumber dn; /* .. */ |
462 | |
463 | decContextDefault(&dc, DEC_INIT_DECIMAL128); /* no traps, please */ |
464 | dc.round=set->round; /* use supplied rounding */ |
465 | |
466 | decNumberFromString(&dn, string, &dc); /* will round if needed */ |
467 | decimal128FromNumber(d128: result, dn: &dn, set: &dc); |
468 | if (dc.status!=0) { /* something happened */ |
469 | decContextSetStatus(set, dc.status); /* .. pass it on */ |
470 | } |
471 | return result; |
472 | } /* decimal128FromString */ |
473 | |
474 | /* ------------------------------------------------------------------ */ |
475 | /* decimal128IsCanonical -- test whether encoding is canonical */ |
476 | /* d128 is the source decimal128 */ |
477 | /* returns 1 if the encoding of d128 is canonical, 0 otherwise */ |
478 | /* No error is possible. */ |
479 | /* ------------------------------------------------------------------ */ |
480 | uInt decimal128IsCanonical(const decimal128 *d128) { |
481 | decNumber dn; /* work */ |
482 | decimal128 canon; /* .. */ |
483 | decContext dc; /* .. */ |
484 | decContextDefault(&dc, DEC_INIT_DECIMAL128); |
485 | decimal128ToNumber(d128, dn: &dn); |
486 | decimal128FromNumber(d128: &canon, dn: &dn, set: &dc);/* canon will now be canonical */ |
487 | return memcmp(s1: d128, s2: &canon, DECIMAL128_Bytes)==0; |
488 | } /* decimal128IsCanonical */ |
489 | |
490 | /* ------------------------------------------------------------------ */ |
491 | /* decimal128Canonical -- copy an encoding, ensuring it is canonical */ |
492 | /* d128 is the source decimal128 */ |
493 | /* result is the target (may be the same decimal128) */ |
494 | /* returns result */ |
495 | /* No error is possible. */ |
496 | /* ------------------------------------------------------------------ */ |
497 | decimal128 * decimal128Canonical(decimal128 *result, const decimal128 *d128) { |
498 | decNumber dn; /* work */ |
499 | decContext dc; /* .. */ |
500 | decContextDefault(&dc, DEC_INIT_DECIMAL128); |
501 | decimal128ToNumber(d128, dn: &dn); |
502 | decimal128FromNumber(d128: result, dn: &dn, set: &dc);/* result will now be canonical */ |
503 | return result; |
504 | } /* decimal128Canonical */ |
505 | |
506 | #if DECTRACE || DECCHECK |
507 | /* Macros for accessing decimal128 fields. These assume the argument |
508 | is a reference (pointer) to the decimal128 structure, and the |
509 | decimal128 is in network byte order (big-endian) */ |
510 | /* Get sign */ |
511 | #define decimal128Sign(d) ((unsigned)(d)->bytes[0]>>7) |
512 | |
513 | /* Get combination field */ |
514 | #define decimal128Comb(d) (((d)->bytes[0] & 0x7c)>>2) |
515 | |
516 | /* Get exponent continuation [does not remove bias] */ |
517 | #define decimal128ExpCon(d) ((((d)->bytes[0] & 0x03)<<10) \ |
518 | | ((unsigned)(d)->bytes[1]<<2) \ |
519 | | ((unsigned)(d)->bytes[2]>>6)) |
520 | |
521 | /* Set sign [this assumes sign previously 0] */ |
522 | #define decimal128SetSign(d, b) { \ |
523 | (d)->bytes[0]|=((unsigned)(b)<<7);} |
524 | |
525 | /* Set exponent continuation [does not apply bias] */ |
526 | /* This assumes range has been checked and exponent previously 0; */ |
527 | /* type of exponent must be unsigned */ |
528 | #define decimal128SetExpCon(d, e) { \ |
529 | (d)->bytes[0]|=(uByte)((e)>>10); \ |
530 | (d)->bytes[1] =(uByte)(((e)&0x3fc)>>2); \ |
531 | (d)->bytes[2]|=(uByte)(((e)&0x03)<<6);} |
532 | |
533 | /* ------------------------------------------------------------------ */ |
534 | /* decimal128Show -- display a decimal128 in hexadecimal [debug aid] */ |
535 | /* d128 -- the number to show */ |
536 | /* ------------------------------------------------------------------ */ |
537 | /* Also shows sign/cob/expconfields extracted */ |
538 | void decimal128Show(const decimal128 *d128) { |
539 | char buf[DECIMAL128_Bytes*2+1]; |
540 | Int i, j=0; |
541 | |
542 | if (DECLITEND) { |
543 | for (i=0; i<DECIMAL128_Bytes; i++, j+=2) { |
544 | sprintf(&buf[j], "%02x" , d128->bytes[15-i]); |
545 | } |
546 | printf(" D128> %s [S:%d Cb:%02x Ec:%02x] LittleEndian\n" , buf, |
547 | d128->bytes[15]>>7, (d128->bytes[15]>>2)&0x1f, |
548 | ((d128->bytes[15]&0x3)<<10)|(d128->bytes[14]<<2)| |
549 | (d128->bytes[13]>>6)); |
550 | } |
551 | else { |
552 | for (i=0; i<DECIMAL128_Bytes; i++, j+=2) { |
553 | sprintf(&buf[j], "%02x" , d128->bytes[i]); |
554 | } |
555 | printf(" D128> %s [S:%d Cb:%02x Ec:%02x] BigEndian\n" , buf, |
556 | decimal128Sign(d128), decimal128Comb(d128), |
557 | decimal128ExpCon(d128)); |
558 | } |
559 | } /* decimal128Show */ |
560 | #endif |
561 | |