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[/] [openrisc/] [trunk/] [gnu-src/] [gdb-6.8/] [libdecnumber/] [dpd/] [decimal128.c] - Blame information for rev 300

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1 24 jeremybenn
/* Decimal 128-bit format module for the decNumber C Library.
2
   Copyright (C) 2005, 2007 Free Software Foundation, Inc.
3
   Contributed by IBM Corporation.  Author Mike Cowlishaw.
4
 
5
   This file is part of GCC.
6
 
7
   GCC is free software; you can redistribute it and/or modify it under
8
   the terms of the GNU General Public License as published by the Free
9
   Software Foundation; either version 2, or (at your option) any later
10
   version.
11
 
12
   In addition to the permissions in the GNU General Public License,
13
   the Free Software Foundation gives you unlimited permission to link
14
   the compiled version of this file into combinations with other
15
   programs, and to distribute those combinations without any
16
   restriction coming from the use of this file.  (The General Public
17
   License restrictions do apply in other respects; for example, they
18
   cover modification of the file, and distribution when not linked
19
   into a combine executable.)
20
 
21
   GCC is distributed in the hope that it will be useful, but WITHOUT ANY
22
   WARRANTY; without even the implied warranty of MERCHANTABILITY or
23
   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
24
   for more details.
25
 
26
   You should have received a copy of the GNU General Public License
27
   along with GCC; see the file COPYING.  If not, write to the Free
28
   Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
29
   02110-1301, USA.  */
30
 
31
/* ------------------------------------------------------------------ */
32
/* Decimal 128-bit format module                                      */
33
/* ------------------------------------------------------------------ */
34
/* This module comprises the routines for decimal128 format numbers.  */
35
/* Conversions are supplied to and from decNumber and String.         */
36
/*                                                                    */
37
/* This is used when decNumber provides operations, either for all    */
38
/* operations or as a proxy between decNumber and decSingle.          */
39
/*                                                                    */
40
/* Error handling is the same as decNumber (qv.).                     */
41
/* ------------------------------------------------------------------ */
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 */
50
 
51
/* Utility routines and tables [in decimal64.c] */
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);
59
 
60
#if DECTRACE || DECCHECK
61
void decimal128Show(const decimal128 *);          /* for debug */
62
extern void decNumberShow(const decNumber *);     /* .. */
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
/* ------------------------------------------------------------------ */
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
/*                                                                    */
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*/
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
/*                                                                    */
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
/* ------------------------------------------------------------------ */
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 */
117
 
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);
124
        }
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 */
132
      /* set and clamp exponent */
133
      if (dn->exponent<-DECIMAL128_Bias) {
134
        exp=0;                                /* low clamp */
135
        status|=DEC_Clamped;
136
        }
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
          }
143
        }
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 */
149
 
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
        }
157
 
158
      /* [fastpath for common case is not a win, here] */
159
      decDigitsToDPD(dn, targar, pad);
160
      /* save and clear the top digit */
161
      msd=targhi>>14;
162
      targhi&=0x00003fff;
163
 
164
      /* create the combination field */
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 */
171
 
172
  if (dn->bits&DECNEG) targhi|=0x80000000; /* add sign bit */
173
 
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 */
190
  /* decimal128Show(d128); */
191
  return d128;
192
  } /* decimal128FromNumber */
193
 
194
/* ------------------------------------------------------------------ */
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.                                              */
199
/* ------------------------------------------------------------------ */
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 */
219
    }
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 */
225
    }
226
 
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 */
246
    }
247
 
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 */
263
  /* decNumberShow(dn); */
264
  return dn;
265
  } /* decimal128ToNumber */
266
 
267
/* ------------------------------------------------------------------ */
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.                   */
280
/* ------------------------------------------------------------------ */
281
char * decimal128ToEngString(const decimal128 *d128, char *string){
282
  decNumber dn;                         /* work */
283
  decimal128ToNumber(d128, &dn);
284
  decNumberToEngString(&dn, string);
285
  return string;
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); */
446
  return string;
447
  } /* decimal128ToString */
448
 
449
/* ------------------------------------------------------------------ */
450
/* to-number -- conversion from numeric string                        */
451
/*                                                                    */
452
/*   decimal128FromString(result, string, set);                       */
453
/*                                                                    */
454
/*  result  is the decimal128 format number which gets the result of  */
455
/*          the conversion                                            */
456
/*  *string is the character string which should contain a valid      */
457
/*          number (which may be a special value)                     */
458
/*  set     is the context                                            */
459
/*                                                                    */
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
/* ------------------------------------------------------------------ */
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 */
476
    }
477
  return result;
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 */
495
 
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 */
511
 
512
#if DECTRACE || DECCHECK
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
 
539
/* ------------------------------------------------------------------ */
540
/* decimal128Show -- display a decimal128 in hexadecimal [debug aid]  */
541
/*   d128 -- the number to show                                       */
542
/* ------------------------------------------------------------------ */
543
/* Also shows sign/cob/expconfields extracted */
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));
564
    }
565
  } /* decimal128Show */
566
#endif

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