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2533577f JJ |
1 | /* Decimal 128-bit format module for the decNumber C Library. |
2 | Copyright (C) 2005, 2007 Free Software Foundation, Inc. | |
473a74b9 BE |
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 | ||
9d1d1cd4 BE |
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 | ||
473a74b9 BE |
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 | |
c0173136 BE |
28 | Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA |
29 | 02110-1301, USA. */ | |
473a74b9 | 30 | |
2533577f JJ |
31 | /* ------------------------------------------------------------------ */ |
32 | /* Decimal 128-bit format module */ | |
473a74b9 BE |
33 | /* ------------------------------------------------------------------ */ |
34 | /* This module comprises the routines for decimal128 format numbers. */ | |
2533577f JJ |
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.). */ | |
473a74b9 | 41 | /* ------------------------------------------------------------------ */ |
2533577f JJ |
42 | #include <string.h> /* [for memset/memcpy] */ |
43 | #include <stdio.h> /* [for printf] */ | |
44 | ||
45 | #include "config.h" /* GCC definitions */ | |
46 | #define DECNUMDIGITS 34 /* make decNumbers with space for 34 */ | |
47 | #include "decNumber.h" /* base number library */ | |
48 | #include "decNumberLocal.h" /* decNumber local types, etc. */ | |
49 | #include "decimal128.h" /* our primary include */ | |
473a74b9 | 50 | |
2533577f | 51 | /* Utility routines and tables [in decimal64.c] */ |
2533577f JJ |
52 | extern const uInt COMBEXP[32], COMBMSD[32]; |
53 | extern const uShort DPD2BIN[1024]; | |
54 | extern const uShort BIN2DPD[1000]; /* [not used] */ | |
55 | extern const uByte BIN2CHAR[4001]; | |
56 | ||
57 | extern void decDigitsFromDPD(decNumber *, const uInt *, Int); | |
58 | extern void decDigitsToDPD(const decNumber *, uInt *, Int); | |
473a74b9 BE |
59 | |
60 | #if DECTRACE || DECCHECK | |
2533577f JJ |
61 | void decimal128Show(const decimal128 *); /* for debug */ |
62 | extern void decNumberShow(const decNumber *); /* .. */ | |
473a74b9 BE |
63 | #endif |
64 | ||
65 | /* Useful macro */ | |
66 | /* Clear a structure (e.g., a decNumber) */ | |
67 | #define DEC_clear(d) memset(d, 0, sizeof(*d)) | |
68 | ||
69 | /* ------------------------------------------------------------------ */ | |
2533577f JJ |
70 | /* decimal128FromNumber -- convert decNumber to decimal128 */ |
71 | /* */ | |
72 | /* ds is the target decimal128 */ | |
73 | /* dn is the source number (assumed valid) */ | |
74 | /* set is the context, used only for reporting errors */ | |
75 | /* */ | |
473a74b9 BE |
76 | /* The set argument is used only for status reporting and for the */ |
77 | /* rounding mode (used if the coefficient is more than DECIMAL128_Pmax*/ | |
2533577f JJ |
78 | /* digits or an overflow is detected). If the exponent is out of the */ |
79 | /* valid range then Overflow or Underflow will be raised. */ | |
80 | /* After Underflow a subnormal result is possible. */ | |
81 | /* */ | |
473a74b9 BE |
82 | /* DEC_Clamped is set if the number has to be 'folded down' to fit, */ |
83 | /* by reducing its exponent and multiplying the coefficient by a */ | |
84 | /* power of ten, or if the exponent on a zero had to be clamped. */ | |
85 | /* ------------------------------------------------------------------ */ | |
2533577f JJ |
86 | decimal128 * decimal128FromNumber(decimal128 *d128, const decNumber *dn, |
87 | decContext *set) { | |
88 | uInt status=0; /* status accumulator */ | |
89 | Int ae; /* adjusted exponent */ | |
90 | decNumber dw; /* work */ | |
91 | decContext dc; /* .. */ | |
92 | uInt *pu; /* .. */ | |
93 | uInt comb, exp; /* .. */ | |
94 | uInt targar[4]={0,0,0,0}; /* target 128-bit */ | |
95 | #define targhi targar[3] /* name the word with the sign */ | |
96 | #define targmh targar[2] /* name the words */ | |
97 | #define targml targar[1] /* .. */ | |
98 | #define targlo targar[0] /* .. */ | |
99 | ||
100 | /* If the number has too many digits, or the exponent could be */ | |
101 | /* out of range then reduce the number under the appropriate */ | |
102 | /* constraints. This could push the number to Infinity or zero, */ | |
103 | /* so this check and rounding must be done before generating the */ | |
104 | /* decimal128] */ | |
105 | ae=dn->exponent+dn->digits-1; /* [0 if special] */ | |
106 | if (dn->digits>DECIMAL128_Pmax /* too many digits */ | |
107 | || ae>DECIMAL128_Emax /* likely overflow */ | |
108 | || ae<DECIMAL128_Emin) { /* likely underflow */ | |
109 | decContextDefault(&dc, DEC_INIT_DECIMAL128); /* [no traps] */ | |
110 | dc.round=set->round; /* use supplied rounding */ | |
111 | decNumberPlus(&dw, dn, &dc); /* (round and check) */ | |
112 | /* [this changes -0 to 0, so enforce the sign...] */ | |
113 | dw.bits|=dn->bits&DECNEG; | |
114 | status=dc.status; /* save status */ | |
115 | dn=&dw; /* use the work number */ | |
116 | } /* maybe out of range */ | |
473a74b9 | 117 | |
2533577f JJ |
118 | if (dn->bits&DECSPECIAL) { /* a special value */ |
119 | if (dn->bits&DECINF) targhi=DECIMAL_Inf<<24; | |
120 | else { /* sNaN or qNaN */ | |
121 | if ((*dn->lsu!=0 || dn->digits>1) /* non-zero coefficient */ | |
122 | && (dn->digits<DECIMAL128_Pmax)) { /* coefficient fits */ | |
123 | decDigitsToDPD(dn, targar, 0); | |
473a74b9 | 124 | } |
2533577f JJ |
125 | if (dn->bits&DECNAN) targhi|=DECIMAL_NaN<<24; |
126 | else targhi|=DECIMAL_sNaN<<24; | |
127 | } /* a NaN */ | |
128 | } /* special */ | |
129 | ||
130 | else { /* is finite */ | |
131 | if (decNumberIsZero(dn)) { /* is a zero */ | |
473a74b9 | 132 | /* set and clamp exponent */ |
2533577f JJ |
133 | if (dn->exponent<-DECIMAL128_Bias) { |
134 | exp=0; /* low clamp */ | |
135 | status|=DEC_Clamped; | |
473a74b9 | 136 | } |
2533577f JJ |
137 | else { |
138 | exp=dn->exponent+DECIMAL128_Bias; /* bias exponent */ | |
139 | if (exp>DECIMAL128_Ehigh) { /* top clamp */ | |
140 | exp=DECIMAL128_Ehigh; | |
141 | status|=DEC_Clamped; | |
142 | } | |
473a74b9 | 143 | } |
2533577f JJ |
144 | comb=(exp>>9) & 0x18; /* msd=0, exp top 2 bits .. */ |
145 | } | |
146 | else { /* non-zero finite number */ | |
147 | uInt msd; /* work */ | |
148 | Int pad=0; /* coefficient pad digits */ | |
473a74b9 | 149 | |
2533577f JJ |
150 | /* the dn is known to fit, but it may need to be padded */ |
151 | exp=(uInt)(dn->exponent+DECIMAL128_Bias); /* bias exponent */ | |
152 | if (exp>DECIMAL128_Ehigh) { /* fold-down case */ | |
153 | pad=exp-DECIMAL128_Ehigh; | |
154 | exp=DECIMAL128_Ehigh; /* [to maximum] */ | |
155 | status|=DEC_Clamped; | |
156 | } | |
473a74b9 | 157 | |
2533577f JJ |
158 | /* [fastpath for common case is not a win, here] */ |
159 | decDigitsToDPD(dn, targar, pad); | |
473a74b9 | 160 | /* save and clear the top digit */ |
2533577f JJ |
161 | msd=targhi>>14; |
162 | targhi&=0x00003fff; | |
473a74b9 BE |
163 | |
164 | /* create the combination field */ | |
2533577f JJ |
165 | if (msd>=8) comb=0x18 | ((exp>>11) & 0x06) | (msd & 0x01); |
166 | else comb=((exp>>9) & 0x18) | msd; | |
167 | } | |
168 | targhi|=comb<<26; /* add combination field .. */ | |
169 | targhi|=(exp&0xfff)<<14; /* .. and exponent continuation */ | |
170 | } /* finite */ | |
473a74b9 | 171 | |
2533577f | 172 | if (dn->bits&DECNEG) targhi|=0x80000000; /* add sign bit */ |
473a74b9 | 173 | |
2533577f JJ |
174 | /* now write to storage; this is endian */ |
175 | pu=(uInt *)d128->bytes; /* overlay */ | |
176 | if (DECLITEND) { | |
177 | pu[0]=targlo; /* directly store the low int */ | |
178 | pu[1]=targml; /* then the mid-low */ | |
179 | pu[2]=targmh; /* then the mid-high */ | |
180 | pu[3]=targhi; /* then the high int */ | |
181 | } | |
182 | else { | |
183 | pu[0]=targhi; /* directly store the high int */ | |
184 | pu[1]=targmh; /* then the mid-high */ | |
185 | pu[2]=targml; /* then the mid-low */ | |
186 | pu[3]=targlo; /* then the low int */ | |
187 | } | |
188 | ||
189 | if (status!=0) decContextSetStatus(set, status); /* pass on status */ | |
473a74b9 BE |
190 | /* decimal128Show(d128); */ |
191 | return d128; | |
2533577f | 192 | } /* decimal128FromNumber */ |
473a74b9 BE |
193 | |
194 | /* ------------------------------------------------------------------ */ | |
2533577f JJ |
195 | /* decimal128ToNumber -- convert decimal128 to decNumber */ |
196 | /* d128 is the source decimal128 */ | |
197 | /* dn is the target number, with appropriate space */ | |
198 | /* No error is possible. */ | |
473a74b9 | 199 | /* ------------------------------------------------------------------ */ |
2533577f JJ |
200 | decNumber * decimal128ToNumber(const decimal128 *d128, decNumber *dn) { |
201 | uInt msd; /* coefficient MSD */ | |
202 | uInt exp; /* exponent top two bits */ | |
203 | uInt comb; /* combination field */ | |
204 | const uInt *pu; /* work */ | |
205 | Int need; /* .. */ | |
206 | uInt sourar[4]; /* source 128-bit */ | |
207 | #define sourhi sourar[3] /* name the word with the sign */ | |
208 | #define sourmh sourar[2] /* and the mid-high word */ | |
209 | #define sourml sourar[1] /* and the mod-low word */ | |
210 | #define sourlo sourar[0] /* and the lowest word */ | |
211 | ||
212 | /* load source from storage; this is endian */ | |
213 | pu=(const uInt *)d128->bytes; /* overlay */ | |
214 | if (DECLITEND) { | |
215 | sourlo=pu[0]; /* directly load the low int */ | |
216 | sourml=pu[1]; /* then the mid-low */ | |
217 | sourmh=pu[2]; /* then the mid-high */ | |
218 | sourhi=pu[3]; /* then the high int */ | |
473a74b9 | 219 | } |
2533577f JJ |
220 | else { |
221 | sourhi=pu[0]; /* directly load the high int */ | |
222 | sourmh=pu[1]; /* then the mid-high */ | |
223 | sourml=pu[2]; /* then the mid-low */ | |
224 | sourlo=pu[3]; /* then the low int */ | |
473a74b9 BE |
225 | } |
226 | ||
2533577f JJ |
227 | comb=(sourhi>>26)&0x1f; /* combination field */ |
228 | ||
229 | decNumberZero(dn); /* clean number */ | |
230 | if (sourhi&0x80000000) dn->bits=DECNEG; /* set sign if negative */ | |
231 | ||
232 | msd=COMBMSD[comb]; /* decode the combination field */ | |
233 | exp=COMBEXP[comb]; /* .. */ | |
234 | ||
235 | if (exp==3) { /* is a special */ | |
236 | if (msd==0) { | |
237 | dn->bits|=DECINF; | |
238 | return dn; /* no coefficient needed */ | |
239 | } | |
240 | else if (sourhi&0x02000000) dn->bits|=DECSNAN; | |
241 | else dn->bits|=DECNAN; | |
242 | msd=0; /* no top digit */ | |
243 | } | |
244 | else { /* is a finite number */ | |
245 | dn->exponent=(exp<<12)+((sourhi>>14)&0xfff)-DECIMAL128_Bias; /* unbiased */ | |
473a74b9 BE |
246 | } |
247 | ||
2533577f JJ |
248 | /* get the coefficient */ |
249 | sourhi&=0x00003fff; /* clean coefficient continuation */ | |
250 | if (msd) { /* non-zero msd */ | |
251 | sourhi|=msd<<14; /* prefix to coefficient */ | |
252 | need=12; /* process 12 declets */ | |
253 | } | |
254 | else { /* msd=0 */ | |
255 | if (sourhi) need=11; /* declets to process */ | |
256 | else if (sourmh) need=10; | |
257 | else if (sourml) need=7; | |
258 | else if (sourlo) need=4; | |
259 | else return dn; /* easy: coefficient is 0 */ | |
260 | } /*msd=0 */ | |
261 | ||
262 | decDigitsFromDPD(dn, sourar, need); /* process declets */ | |
473a74b9 BE |
263 | /* decNumberShow(dn); */ |
264 | return dn; | |
2533577f | 265 | } /* decimal128ToNumber */ |
473a74b9 BE |
266 | |
267 | /* ------------------------------------------------------------------ */ | |
2533577f JJ |
268 | /* to-scientific-string -- conversion to numeric string */ |
269 | /* to-engineering-string -- conversion to numeric string */ | |
270 | /* */ | |
271 | /* decimal128ToString(d128, string); */ | |
272 | /* decimal128ToEngString(d128, string); */ | |
273 | /* */ | |
274 | /* d128 is the decimal128 format number to convert */ | |
275 | /* string is the string where the result will be laid out */ | |
276 | /* */ | |
277 | /* string must be at least 24 characters */ | |
278 | /* */ | |
279 | /* No error is possible, and no status can be set. */ | |
473a74b9 | 280 | /* ------------------------------------------------------------------ */ |
2533577f JJ |
281 | char * decimal128ToEngString(const decimal128 *d128, char *string){ |
282 | decNumber dn; /* work */ | |
283 | decimal128ToNumber(d128, &dn); | |
284 | decNumberToEngString(&dn, string); | |
473a74b9 | 285 | return string; |
2533577f JJ |
286 | } /* decimal128ToEngString */ |
287 | ||
288 | char * decimal128ToString(const decimal128 *d128, char *string){ | |
289 | uInt msd; /* coefficient MSD */ | |
290 | Int exp; /* exponent top two bits or full */ | |
291 | uInt comb; /* combination field */ | |
292 | char *cstart; /* coefficient start */ | |
293 | char *c; /* output pointer in string */ | |
294 | const uInt *pu; /* work */ | |
295 | char *s, *t; /* .. (source, target) */ | |
296 | Int dpd; /* .. */ | |
297 | Int pre, e; /* .. */ | |
298 | const uByte *u; /* .. */ | |
299 | ||
300 | uInt sourar[4]; /* source 128-bit */ | |
301 | #define sourhi sourar[3] /* name the word with the sign */ | |
302 | #define sourmh sourar[2] /* and the mid-high word */ | |
303 | #define sourml sourar[1] /* and the mod-low word */ | |
304 | #define sourlo sourar[0] /* and the lowest word */ | |
305 | ||
306 | /* load source from storage; this is endian */ | |
307 | pu=(const uInt *)d128->bytes; /* overlay */ | |
308 | if (DECLITEND) { | |
309 | sourlo=pu[0]; /* directly load the low int */ | |
310 | sourml=pu[1]; /* then the mid-low */ | |
311 | sourmh=pu[2]; /* then the mid-high */ | |
312 | sourhi=pu[3]; /* then the high int */ | |
313 | } | |
314 | else { | |
315 | sourhi=pu[0]; /* directly load the high int */ | |
316 | sourmh=pu[1]; /* then the mid-high */ | |
317 | sourml=pu[2]; /* then the mid-low */ | |
318 | sourlo=pu[3]; /* then the low int */ | |
319 | } | |
320 | ||
321 | c=string; /* where result will go */ | |
322 | if (((Int)sourhi)<0) *c++='-'; /* handle sign */ | |
323 | ||
324 | comb=(sourhi>>26)&0x1f; /* combination field */ | |
325 | msd=COMBMSD[comb]; /* decode the combination field */ | |
326 | exp=COMBEXP[comb]; /* .. */ | |
327 | ||
328 | if (exp==3) { | |
329 | if (msd==0) { /* infinity */ | |
330 | strcpy(c, "Inf"); | |
331 | strcpy(c+3, "inity"); | |
332 | return string; /* easy */ | |
333 | } | |
334 | if (sourhi&0x02000000) *c++='s'; /* sNaN */ | |
335 | strcpy(c, "NaN"); /* complete word */ | |
336 | c+=3; /* step past */ | |
337 | if (sourlo==0 && sourml==0 && sourmh==0 | |
338 | && (sourhi&0x0003ffff)==0) return string; /* zero payload */ | |
339 | /* otherwise drop through to add integer; set correct exp */ | |
340 | exp=0; msd=0; /* setup for following code */ | |
341 | } | |
342 | else exp=(exp<<12)+((sourhi>>14)&0xfff)-DECIMAL128_Bias; /* unbiased */ | |
343 | ||
344 | /* convert 34 digits of significand to characters */ | |
345 | cstart=c; /* save start of coefficient */ | |
346 | if (msd) *c++='0'+(char)msd; /* non-zero most significant digit */ | |
347 | ||
348 | /* Now decode the declets. After extracting each one, it is */ | |
349 | /* decoded to binary and then to a 4-char sequence by table lookup; */ | |
350 | /* the 4-chars are a 1-char length (significant digits, except 000 */ | |
351 | /* has length 0). This allows us to left-align the first declet */ | |
352 | /* with non-zero content, then remaining ones are full 3-char */ | |
353 | /* length. We use fixed-length memcpys because variable-length */ | |
354 | /* causes a subroutine call in GCC. (These are length 4 for speed */ | |
355 | /* and are safe because the array has an extra terminator byte.) */ | |
356 | #define dpd2char u=&BIN2CHAR[DPD2BIN[dpd]*4]; \ | |
357 | if (c!=cstart) {memcpy(c, u+1, 4); c+=3;} \ | |
358 | else if (*u) {memcpy(c, u+4-*u, 4); c+=*u;} | |
359 | dpd=(sourhi>>4)&0x3ff; /* declet 1 */ | |
360 | dpd2char; | |
361 | dpd=((sourhi&0xf)<<6) | (sourmh>>26); /* declet 2 */ | |
362 | dpd2char; | |
363 | dpd=(sourmh>>16)&0x3ff; /* declet 3 */ | |
364 | dpd2char; | |
365 | dpd=(sourmh>>6)&0x3ff; /* declet 4 */ | |
366 | dpd2char; | |
367 | dpd=((sourmh&0x3f)<<4) | (sourml>>28); /* declet 5 */ | |
368 | dpd2char; | |
369 | dpd=(sourml>>18)&0x3ff; /* declet 6 */ | |
370 | dpd2char; | |
371 | dpd=(sourml>>8)&0x3ff; /* declet 7 */ | |
372 | dpd2char; | |
373 | dpd=((sourml&0xff)<<2) | (sourlo>>30); /* declet 8 */ | |
374 | dpd2char; | |
375 | dpd=(sourlo>>20)&0x3ff; /* declet 9 */ | |
376 | dpd2char; | |
377 | dpd=(sourlo>>10)&0x3ff; /* declet 10 */ | |
378 | dpd2char; | |
379 | dpd=(sourlo)&0x3ff; /* declet 11 */ | |
380 | dpd2char; | |
381 | ||
382 | if (c==cstart) *c++='0'; /* all zeros -- make 0 */ | |
383 | ||
384 | if (exp==0) { /* integer or NaN case -- easy */ | |
385 | *c='\0'; /* terminate */ | |
386 | return string; | |
387 | } | |
388 | ||
389 | /* non-0 exponent */ | |
390 | e=0; /* assume no E */ | |
391 | pre=c-cstart+exp; | |
392 | /* [here, pre-exp is the digits count (==1 for zero)] */ | |
393 | if (exp>0 || pre<-5) { /* need exponential form */ | |
394 | e=pre-1; /* calculate E value */ | |
395 | pre=1; /* assume one digit before '.' */ | |
396 | } /* exponential form */ | |
397 | ||
398 | /* modify the coefficient, adding 0s, '.', and E+nn as needed */ | |
399 | s=c-1; /* source (LSD) */ | |
400 | if (pre>0) { /* ddd.ddd (plain), perhaps with E */ | |
401 | char *dotat=cstart+pre; | |
402 | if (dotat<c) { /* if embedded dot needed... */ | |
403 | t=c; /* target */ | |
404 | for (; s>=dotat; s--, t--) *t=*s; /* open the gap; leave t at gap */ | |
405 | *t='.'; /* insert the dot */ | |
406 | c++; /* length increased by one */ | |
407 | } | |
408 | ||
409 | /* finally add the E-part, if needed; it will never be 0, and has */ | |
410 | /* a maximum length of 4 digits */ | |
411 | if (e!=0) { | |
412 | *c++='E'; /* starts with E */ | |
413 | *c++='+'; /* assume positive */ | |
414 | if (e<0) { | |
415 | *(c-1)='-'; /* oops, need '-' */ | |
416 | e=-e; /* uInt, please */ | |
417 | } | |
418 | if (e<1000) { /* 3 (or fewer) digits case */ | |
419 | u=&BIN2CHAR[e*4]; /* -> length byte */ | |
420 | memcpy(c, u+4-*u, 4); /* copy fixed 4 characters [is safe] */ | |
421 | c+=*u; /* bump pointer appropriately */ | |
422 | } | |
423 | else { /* 4-digits */ | |
424 | Int thou=((e>>3)*1049)>>17; /* e/1000 */ | |
425 | Int rem=e-(1000*thou); /* e%1000 */ | |
426 | *c++='0'+(char)thou; | |
427 | u=&BIN2CHAR[rem*4]; /* -> length byte */ | |
428 | memcpy(c, u+1, 4); /* copy fixed 3+1 characters [is safe] */ | |
429 | c+=3; /* bump pointer, always 3 digits */ | |
430 | } | |
431 | } | |
432 | *c='\0'; /* add terminator */ | |
433 | /*printf("res %s\n", string); */ | |
434 | return string; | |
435 | } /* pre>0 */ | |
436 | ||
437 | /* -5<=pre<=0: here for plain 0.ddd or 0.000ddd forms (can never have E) */ | |
438 | t=c+1-pre; | |
439 | *(t+1)='\0'; /* can add terminator now */ | |
440 | for (; s>=cstart; s--, t--) *t=*s; /* shift whole coefficient right */ | |
441 | c=cstart; | |
442 | *c++='0'; /* always starts with 0. */ | |
443 | *c++='.'; | |
444 | for (; pre<0; pre++) *c++='0'; /* add any 0's after '.' */ | |
445 | /*printf("res %s\n", string); */ | |
473a74b9 | 446 | return string; |
2533577f | 447 | } /* decimal128ToString */ |
473a74b9 BE |
448 | |
449 | /* ------------------------------------------------------------------ */ | |
2533577f JJ |
450 | /* to-number -- conversion from numeric string */ |
451 | /* */ | |
452 | /* decimal128FromString(result, string, set); */ | |
453 | /* */ | |
473a74b9 | 454 | /* result is the decimal128 format number which gets the result of */ |
2533577f | 455 | /* the conversion */ |
473a74b9 | 456 | /* *string is the character string which should contain a valid */ |
2533577f JJ |
457 | /* number (which may be a special value) */ |
458 | /* set is the context */ | |
459 | /* */ | |
473a74b9 BE |
460 | /* The context is supplied to this routine is used for error handling */ |
461 | /* (setting of status and traps) and for the rounding mode, only. */ | |
462 | /* If an error occurs, the result will be a valid decimal128 NaN. */ | |
463 | /* ------------------------------------------------------------------ */ | |
2533577f JJ |
464 | decimal128 * decimal128FromString(decimal128 *result, const char *string, |
465 | decContext *set) { | |
466 | decContext dc; /* work */ | |
467 | decNumber dn; /* .. */ | |
468 | ||
469 | decContextDefault(&dc, DEC_INIT_DECIMAL128); /* no traps, please */ | |
470 | dc.round=set->round; /* use supplied rounding */ | |
471 | ||
472 | decNumberFromString(&dn, string, &dc); /* will round if needed */ | |
473 | decimal128FromNumber(result, &dn, &dc); | |
474 | if (dc.status!=0) { /* something happened */ | |
475 | decContextSetStatus(set, dc.status); /* .. pass it on */ | |
473a74b9 BE |
476 | } |
477 | return result; | |
2533577f JJ |
478 | } /* decimal128FromString */ |
479 | ||
480 | /* ------------------------------------------------------------------ */ | |
481 | /* decimal128IsCanonical -- test whether encoding is canonical */ | |
482 | /* d128 is the source decimal128 */ | |
483 | /* returns 1 if the encoding of d128 is canonical, 0 otherwise */ | |
484 | /* No error is possible. */ | |
485 | /* ------------------------------------------------------------------ */ | |
486 | uint32_t decimal128IsCanonical(const decimal128 *d128) { | |
487 | decNumber dn; /* work */ | |
488 | decimal128 canon; /* .. */ | |
489 | decContext dc; /* .. */ | |
490 | decContextDefault(&dc, DEC_INIT_DECIMAL128); | |
491 | decimal128ToNumber(d128, &dn); | |
492 | decimal128FromNumber(&canon, &dn, &dc);/* canon will now be canonical */ | |
493 | return memcmp(d128, &canon, DECIMAL128_Bytes)==0; | |
494 | } /* decimal128IsCanonical */ | |
473a74b9 | 495 | |
2533577f JJ |
496 | /* ------------------------------------------------------------------ */ |
497 | /* decimal128Canonical -- copy an encoding, ensuring it is canonical */ | |
498 | /* d128 is the source decimal128 */ | |
499 | /* result is the target (may be the same decimal128) */ | |
500 | /* returns result */ | |
501 | /* No error is possible. */ | |
502 | /* ------------------------------------------------------------------ */ | |
503 | decimal128 * decimal128Canonical(decimal128 *result, const decimal128 *d128) { | |
504 | decNumber dn; /* work */ | |
505 | decContext dc; /* .. */ | |
506 | decContextDefault(&dc, DEC_INIT_DECIMAL128); | |
507 | decimal128ToNumber(d128, &dn); | |
508 | decimal128FromNumber(result, &dn, &dc);/* result will now be canonical */ | |
509 | return result; | |
510 | } /* decimal128Canonical */ | |
473a74b9 BE |
511 | |
512 | #if DECTRACE || DECCHECK | |
2533577f JJ |
513 | /* Macros for accessing decimal128 fields. These assume the argument |
514 | is a reference (pointer) to the decimal128 structure, and the | |
515 | decimal128 is in network byte order (big-endian) */ | |
516 | /* Get sign */ | |
517 | #define decimal128Sign(d) ((unsigned)(d)->bytes[0]>>7) | |
518 | ||
519 | /* Get combination field */ | |
520 | #define decimal128Comb(d) (((d)->bytes[0] & 0x7c)>>2) | |
521 | ||
522 | /* Get exponent continuation [does not remove bias] */ | |
523 | #define decimal128ExpCon(d) ((((d)->bytes[0] & 0x03)<<10) \ | |
524 | | ((unsigned)(d)->bytes[1]<<2) \ | |
525 | | ((unsigned)(d)->bytes[2]>>6)) | |
526 | ||
527 | /* Set sign [this assumes sign previously 0] */ | |
528 | #define decimal128SetSign(d, b) { \ | |
529 | (d)->bytes[0]|=((unsigned)(b)<<7);} | |
530 | ||
531 | /* Set exponent continuation [does not apply bias] */ | |
532 | /* This assumes range has been checked and exponent previously 0; */ | |
533 | /* type of exponent must be unsigned */ | |
534 | #define decimal128SetExpCon(d, e) { \ | |
535 | (d)->bytes[0]|=(uint8_t)((e)>>10); \ | |
536 | (d)->bytes[1] =(uint8_t)(((e)&0x3fc)>>2); \ | |
537 | (d)->bytes[2]|=(uint8_t)(((e)&0x03)<<6);} | |
538 | ||
473a74b9 | 539 | /* ------------------------------------------------------------------ */ |
2533577f JJ |
540 | /* decimal128Show -- display a decimal128 in hexadecimal [debug aid] */ |
541 | /* d128 -- the number to show */ | |
473a74b9 BE |
542 | /* ------------------------------------------------------------------ */ |
543 | /* Also shows sign/cob/expconfields extracted */ | |
2533577f JJ |
544 | void decimal128Show(const decimal128 *d128) { |
545 | char buf[DECIMAL128_Bytes*2+1]; | |
546 | Int i, j=0; | |
547 | ||
548 | if (DECLITEND) { | |
549 | for (i=0; i<DECIMAL128_Bytes; i++, j+=2) { | |
550 | sprintf(&buf[j], "%02x", d128->bytes[15-i]); | |
551 | } | |
552 | printf(" D128> %s [S:%d Cb:%02x Ec:%02x] LittleEndian\n", buf, | |
553 | d128->bytes[15]>>7, (d128->bytes[15]>>2)&0x1f, | |
554 | ((d128->bytes[15]&0x3)<<10)|(d128->bytes[14]<<2)| | |
555 | (d128->bytes[13]>>6)); | |
556 | } | |
557 | else { | |
558 | for (i=0; i<DECIMAL128_Bytes; i++, j+=2) { | |
559 | sprintf(&buf[j], "%02x", d128->bytes[i]); | |
560 | } | |
561 | printf(" D128> %s [S:%d Cb:%02x Ec:%02x] BigEndian\n", buf, | |
562 | decimal128Sign(d128), decimal128Comb(d128), | |
563 | decimal128ExpCon(d128)); | |
473a74b9 | 564 | } |
2533577f | 565 | } /* decimal128Show */ |
473a74b9 | 566 | #endif |