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[/] [openrisc/] [trunk/] [gnu-src/] [gdb-7.1/] [libdecnumber/] [decCommon.c] - Blame information for rev 227

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1 227 jeremybenn
/* Common code for fixed-size types in the decNumber C Library.
2
   Copyright (C) 2007, 2009 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
/* decCommon.c -- common code for all three fixed-size types          */
28
/* ------------------------------------------------------------------ */
29
/* This module comprises code that is shared between all the formats  */
30
/* (decSingle, decDouble, and decQuad); it includes set and extract   */
31
/* of format components, widening, narrowing, and string conversions. */
32
/*                                                                    */
33
/* Unlike decNumber, parameterization takes place at compile time     */
34
/* rather than at runtime.  The parameters are set in the decDouble.c */
35
/* (etc.) files, which then include this one to produce the compiled  */
36
/* code.  The functions here, therefore, are code shared between      */
37
/* multiple formats.                                                  */
38
/* ------------------------------------------------------------------ */
39
/* Names here refer to decFloat rather than to decDouble, etc., and */
40
/* the functions are in strict alphabetical order. */
41
/* Constants, tables, and debug function(s) are included only for QUAD */
42
/* (which will always be compiled if DOUBLE or SINGLE are used). */
43
/* */
44
/* Whenever a decContext is used, only the status may be set (using */
45
/* OR) or the rounding mode read; all other fields are ignored and */
46
/* untouched. */
47
 
48
#include "decCommonSymbols.h"
49
 
50
/* names for simpler testing and default context */
51
#if DECPMAX==7
52
  #define SINGLE     1
53
  #define DOUBLE     0
54
  #define QUAD       0
55
  #define DEFCONTEXT DEC_INIT_DECIMAL32
56
#elif DECPMAX==16
57
  #define SINGLE     0
58
  #define DOUBLE     1
59
  #define QUAD       0
60
  #define DEFCONTEXT DEC_INIT_DECIMAL64
61
#elif DECPMAX==34
62
  #define SINGLE     0
63
  #define DOUBLE     0
64
  #define QUAD       1
65
  #define DEFCONTEXT DEC_INIT_DECIMAL128
66
#else
67
  #error Unexpected DECPMAX value
68
#endif
69
 
70
/* Assertions */
71
 
72
#if DECPMAX!=7 && DECPMAX!=16 && DECPMAX!=34
73
  #error Unexpected Pmax (DECPMAX) value for this module
74
#endif
75
 
76
/* Assert facts about digit characters, etc. */
77
#if ('9'&0x0f)!=9
78
  #error This module assumes characters are of the form 0b....nnnn
79
  /* where .... are don't care 4 bits and nnnn is 0000 through 1001 */
80
#endif
81
#if ('9'&0xf0)==('.'&0xf0)
82
  #error This module assumes '.' has a different mask than a digit
83
#endif
84
 
85
/* Assert ToString lay-out conditions */
86
#if DECSTRING<DECPMAX+9
87
  #error ToString needs at least 8 characters for lead-in and dot
88
#endif
89
#if DECPMAX+DECEMAXD+5 > DECSTRING
90
  #error Exponent form can be too long for ToString to lay out safely
91
#endif
92
#if DECEMAXD > 4
93
  #error Exponent form is too long for ToString to lay out
94
  /* Note: code for up to 9 digits exists in archives [decOct] */
95
#endif
96
 
97
/* Private functions used here and possibly in decBasic.c, etc. */
98
static decFloat * decFinalize(decFloat *, bcdnum *, decContext *);
99
static Flag decBiStr(const char *, const char *, const char *);
100
 
101
/* Macros and private tables; those which are not format-dependent    */
102
/* are only included if decQuad is being built.                       */
103
 
104
/* ------------------------------------------------------------------ */
105
/* Combination field lookup tables (uInts to save measurable work)    */
106
/*                                                                    */
107
/*   DECCOMBEXP  - 2 most-significant-bits of exponent (00, 01, or    */
108
/*                 10), shifted left for format, or DECFLOAT_Inf/NaN  */
109
/*   DECCOMBWEXP - The same, for the next-wider format (unless QUAD)  */
110
/*   DECCOMBMSD  - 4-bit most-significant-digit                       */
111
/*                 [0 if the index is a special (Infinity or NaN)]    */
112
/*   DECCOMBFROM - 5-bit combination field from EXP top bits and MSD  */
113
/*                 (placed in uInt so no shift is needed)             */
114
/*                                                                    */
115
/* DECCOMBEXP, DECCOMBWEXP, and DECCOMBMSD are indexed by the sign    */
116
/*   and 5-bit combination field (0-63, the second half of the table  */
117
/*   identical to the first half)                                     */
118
/* DECCOMBFROM is indexed by expTopTwoBits*16 + msd                   */
119
/*                                                                    */
120
/* DECCOMBMSD and DECCOMBFROM are not format-dependent and so are     */
121
/* only included once, when QUAD is being built                       */
122
/* ------------------------------------------------------------------ */
123
static const uInt DECCOMBEXP[64]={
124
  0, 0, 0, 0, 0, 0, 0, 0,
125
  1<<DECECONL, 1<<DECECONL, 1<<DECECONL, 1<<DECECONL,
126
  1<<DECECONL, 1<<DECECONL, 1<<DECECONL, 1<<DECECONL,
127
  2<<DECECONL, 2<<DECECONL, 2<<DECECONL, 2<<DECECONL,
128
  2<<DECECONL, 2<<DECECONL, 2<<DECECONL, 2<<DECECONL,
129
  0,            0,            1<<DECECONL, 1<<DECECONL,
130
  2<<DECECONL, 2<<DECECONL, DECFLOAT_Inf, DECFLOAT_NaN,
131
  0, 0, 0, 0, 0, 0, 0, 0,
132
  1<<DECECONL, 1<<DECECONL, 1<<DECECONL, 1<<DECECONL,
133
  1<<DECECONL, 1<<DECECONL, 1<<DECECONL, 1<<DECECONL,
134
  2<<DECECONL, 2<<DECECONL, 2<<DECECONL, 2<<DECECONL,
135
  2<<DECECONL, 2<<DECECONL, 2<<DECECONL, 2<<DECECONL,
136
  0,            0,            1<<DECECONL, 1<<DECECONL,
137
  2<<DECECONL, 2<<DECECONL, DECFLOAT_Inf, DECFLOAT_NaN};
138
#if !QUAD
139
static const uInt DECCOMBWEXP[64]={
140
  0, 0, 0, 0, 0, 0, 0, 0,
141
  1<<DECWECONL, 1<<DECWECONL, 1<<DECWECONL, 1<<DECWECONL,
142
  1<<DECWECONL, 1<<DECWECONL, 1<<DECWECONL, 1<<DECWECONL,
143
  2<<DECWECONL, 2<<DECWECONL, 2<<DECWECONL, 2<<DECWECONL,
144
  2<<DECWECONL, 2<<DECWECONL, 2<<DECWECONL, 2<<DECWECONL,
145
  0,             0,             1<<DECWECONL, 1<<DECWECONL,
146
  2<<DECWECONL, 2<<DECWECONL, DECFLOAT_Inf, DECFLOAT_NaN,
147
  0, 0, 0, 0, 0, 0, 0, 0,
148
  1<<DECWECONL, 1<<DECWECONL, 1<<DECWECONL, 1<<DECWECONL,
149
  1<<DECWECONL, 1<<DECWECONL, 1<<DECWECONL, 1<<DECWECONL,
150
  2<<DECWECONL, 2<<DECWECONL, 2<<DECWECONL, 2<<DECWECONL,
151
  2<<DECWECONL, 2<<DECWECONL, 2<<DECWECONL, 2<<DECWECONL,
152
  0,             0,             1<<DECWECONL, 1<<DECWECONL,
153
  2<<DECWECONL, 2<<DECWECONL, DECFLOAT_Inf, DECFLOAT_NaN};
154
#endif
155
 
156
#if QUAD
157
const uInt DECCOMBMSD[64]={
158
  0, 1, 2, 3, 4, 5, 6, 7, 0, 1, 2, 3, 4, 5, 6, 7,
159
  0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 8, 9, 8, 9, 0, 0,
160
  0, 1, 2, 3, 4, 5, 6, 7, 0, 1, 2, 3, 4, 5, 6, 7,
161
  0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 8, 9, 8, 9, 0, 0};
162
 
163
const uInt DECCOMBFROM[48]={
164
  0x00000000, 0x04000000, 0x08000000, 0x0C000000, 0x10000000, 0x14000000,
165
  0x18000000, 0x1C000000, 0x60000000, 0x64000000, 0x00000000, 0x00000000,
166
  0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x20000000, 0x24000000,
167
  0x28000000, 0x2C000000, 0x30000000, 0x34000000, 0x38000000, 0x3C000000,
168
  0x68000000, 0x6C000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
169
  0x00000000, 0x00000000, 0x40000000, 0x44000000, 0x48000000, 0x4C000000,
170
  0x50000000, 0x54000000, 0x58000000, 0x5C000000, 0x70000000, 0x74000000,
171
  0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000};
172
 
173
/* ------------------------------------------------------------------ */
174
/* Request and include the tables to use for conversions              */
175
/* ------------------------------------------------------------------ */
176
#define DEC_BCD2DPD  1        /* 0-0x999 -> DPD */
177
#define DEC_BIN2DPD  1        /* 0-999 -> DPD */
178
#define DEC_BIN2BCD8 1        /* 0-999 -> ddd, len */
179
#define DEC_DPD2BCD8 1        /* DPD -> ddd, len */
180
#define DEC_DPD2BIN  1        /* DPD -> 0-999 */
181
#define DEC_DPD2BINK 1        /* DPD -> 0-999000 */
182
#define DEC_DPD2BINM 1        /* DPD -> 0-999000000 */
183
#include "decDPD.h"           /* source of the lookup tables */
184
 
185
#endif
186
 
187
/* ----------------------------------------------------------------- */
188
/* decBiStr -- compare string with pairwise options                  */
189
/*                                                                   */
190
/*   targ is the string to compare                                   */
191
/*   str1 is one of the strings to compare against (length may be 0) */
192
/*   str2 is the other; it must be the same length as str1           */
193
/*                                                                   */
194
/*   returns 1 if strings compare equal, (that is, targ is the same  */
195
/*   length as str1 and str2, and each character of targ is in one   */
196
/*   of str1 or str2 in the corresponding position), or 0 otherwise  */
197
/*                                                                   */
198
/* This is used for generic caseless compare, including the awkward  */
199
/* case of the Turkish dotted and dotless Is.  Use as (for example): */
200
/*   if (decBiStr(test, "mike", "MIKE")) ...                         */
201
/* ----------------------------------------------------------------- */
202
static Flag decBiStr(const char *targ, const char *str1, const char *str2) {
203
  for (;;targ++, str1++, str2++) {
204
    if (*targ!=*str1 && *targ!=*str2) return 0;
205
    /* *targ has a match in one (or both, if terminator) */
206
    if (*targ=='\0') break;
207
    } /* forever */
208
  return 1;
209
  } /* decBiStr */
210
 
211
/* ------------------------------------------------------------------ */
212
/* decFinalize -- adjust and store a final result                     */
213
/*                                                                    */
214
/*  df  is the decFloat format number which gets the final result     */
215
/*  num is the descriptor of the number to be checked and encoded     */
216
/*         [its values, including the coefficient, may be modified]   */
217
/*  set is the context to use                                         */
218
/*  returns df                                                        */
219
/*                                                                    */
220
/* The num descriptor may point to a bcd8 string of any length; this  */
221
/* string may have leading insignificant zeros.  If it has more than  */
222
/* DECPMAX digits then the final digit can be a round-for-reround     */
223
/* digit (i.e., it may include a sticky bit residue).                 */
224
/*                                                                    */
225
/* The exponent (q) may be one of the codes for a special value and   */
226
/* can be up to 999999999 for conversion from string.                 */
227
/*                                                                    */
228
/* No error is possible, but Inexact, Underflow, and/or Overflow may  */
229
/* be set.                                                            */
230
/* ------------------------------------------------------------------ */
231
/* Constant whose size varies with format; also the check for surprises */
232
static uByte allnines[DECPMAX]=
233
#if SINGLE
234
  {9, 9, 9, 9, 9, 9, 9};
235
#elif DOUBLE
236
  {9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9};
237
#elif QUAD
238
  {9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
239
   9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9};
240
#endif
241
 
242
static decFloat * decFinalize(decFloat *df, bcdnum *num,
243
                              decContext *set) {
244
  uByte *ub;                  /* work */
245
  uInt   dpd;                 /* .. */
246
  uInt   uiwork;              /* for macros */
247
  uByte *umsd=num->msd;       /* local copy */
248
  uByte *ulsd=num->lsd;       /* .. */
249
  uInt   encode;              /* encoding accumulator */
250
  Int    length;              /* coefficient length */
251
 
252
  #if DECCHECK
253
  Int clen=ulsd-umsd+1;
254
  #if QUAD
255
    #define COEXTRA 2                        /* extra-long coefficent */
256
  #else
257
    #define COEXTRA 0
258
  #endif
259
  if (clen<1 || clen>DECPMAX*3+2+COEXTRA)
260
    printf("decFinalize: suspect coefficient [length=%ld]\n", (LI)clen);
261
  if (num->sign!=0 && num->sign!=DECFLOAT_Sign)
262
    printf("decFinalize: bad sign [%08lx]\n", (LI)num->sign);
263
  if (!EXPISSPECIAL(num->exponent)
264
      && (num->exponent>1999999999 || num->exponent<-1999999999))
265
    printf("decFinalize: improbable exponent [%ld]\n", (LI)num->exponent);
266
  /* decShowNum(num, "final"); */
267
  #endif
268
 
269
  /* A special will have an 'exponent' which is very positive and a */
270
  /* coefficient < DECPMAX */
271
  length=(uInt)(ulsd-umsd+1);                /* coefficient length */
272
 
273
  if (!NUMISSPECIAL(num)) {
274
    Int   drop;                              /* digits to be dropped */
275
    /* skip leading insignificant zeros to calculate an exact length */
276
    /* [this is quite expensive] */
277
    if (*umsd==0) {
278
      for (; umsd+3<ulsd && UBTOUI(umsd)==0;) umsd+=4;
279
      for (; *umsd==0 && umsd<ulsd;) umsd++;
280
      length=ulsd-umsd+1;                    /* recalculate */
281
      }
282
    drop=MAXI(length-DECPMAX, DECQTINY-num->exponent);
283
    /* drop can now be > digits for bottom-clamp (subnormal) cases */
284
    if (drop>0) {                             /* rounding needed */
285
      /* (decFloatQuantize has very similar code to this, so any */
286
      /* changes may need to be made there, too) */
287
      uByte *roundat;                        /* -> re-round digit */
288
      uByte reround;                         /* reround value */
289
      /* printf("Rounding; drop=%ld\n", (LI)drop); */
290
 
291
      num->exponent+=drop;                   /* always update exponent */
292
 
293
      /* Three cases here: */
294
      /*   1. new LSD is in coefficient (almost always) */
295
      /*   2. new LSD is digit to left of coefficient (so MSD is */
296
      /*      round-for-reround digit) */
297
      /*   3. new LSD is to left of case 2 (whole coefficient is sticky) */
298
      /* [duplicate check-stickies code to save a test] */
299
      /* [by-digit check for stickies as runs of zeros are rare] */
300
      if (drop<length) {                     /* NB lengths not addresses */
301
        roundat=umsd+length-drop;
302
        reround=*roundat;
303
        for (ub=roundat+1; ub<=ulsd; ub++) {
304
          if (*ub!=0) {               /* non-zero to be discarded */
305
            reround=DECSTICKYTAB[reround];   /* apply sticky bit */
306
            break;                           /* [remainder don't-care] */
307
            }
308
          } /* check stickies */
309
        ulsd=roundat-1;                      /* new LSD */
310
        }
311
       else {                                /* edge case */
312
        if (drop==length) {
313
          roundat=umsd;
314
          reround=*roundat;
315
          }
316
         else {
317
          roundat=umsd-1;
318
          reround=0;
319
          }
320
        for (ub=roundat+1; ub<=ulsd; ub++) {
321
          if (*ub!=0) {               /* non-zero to be discarded */
322
            reround=DECSTICKYTAB[reround];   /* apply sticky bit */
323
            break;                           /* [remainder don't-care] */
324
            }
325
          } /* check stickies */
326
        *umsd=0;                      /* coefficient is a 0 */
327
        ulsd=umsd;                           /* .. */
328
        }
329
 
330
      if (reround!=0) {               /* discarding non-zero */
331
        uInt bump=0;
332
        set->status|=DEC_Inexact;
333
        /* if adjusted exponent [exp+digits-1] is < EMIN then num is */
334
        /* subnormal -- so raise Underflow */
335
        if (num->exponent<DECEMIN && (num->exponent+(ulsd-umsd+1)-1)<DECEMIN)
336
          set->status|=DEC_Underflow;
337
 
338
        /* next decide whether increment of the coefficient is needed */
339
        if (set->round==DEC_ROUND_HALF_EVEN) {    /* fastpath slowest case */
340
          if (reround>5) bump=1;                  /* >0.5 goes up */
341
           else if (reround==5)                   /* exactly 0.5000 .. */
342
            bump=*ulsd & 0x01;                    /* .. up iff [new] lsd is odd */
343
          } /* r-h-e */
344
         else switch (set->round) {
345
          case DEC_ROUND_DOWN: {
346
            /* no change */
347
            break;} /* r-d */
348
          case DEC_ROUND_HALF_DOWN: {
349
            if (reround>5) bump=1;
350
            break;} /* r-h-d */
351
          case DEC_ROUND_HALF_UP: {
352
            if (reround>=5) bump=1;
353
            break;} /* r-h-u */
354
          case DEC_ROUND_UP: {
355
            if (reround>0) bump=1;
356
            break;} /* r-u */
357
          case DEC_ROUND_CEILING: {
358
            /* same as _UP for positive numbers, and as _DOWN for negatives */
359
            if (!num->sign && reround>0) bump=1;
360
            break;} /* r-c */
361
          case DEC_ROUND_FLOOR: {
362
            /* same as _UP for negative numbers, and as _DOWN for positive */
363
            /* [negative reround cannot occur on 0] */
364
            if (num->sign && reround>0) bump=1;
365
            break;} /* r-f */
366
          case DEC_ROUND_05UP: {
367
            if (reround>0) { /* anything out there is 'sticky' */
368
              /* bump iff lsd=0 or 5; this cannot carry so it could be */
369
              /* effected immediately with no bump -- but the code */
370
              /* is clearer if this is done the same way as the others */
371
              if (*ulsd==0 || *ulsd==5) bump=1;
372
              }
373
            break;} /* r-r */
374
          default: {      /* e.g., DEC_ROUND_MAX */
375
            set->status|=DEC_Invalid_context;
376
            #if DECCHECK
377
            printf("Unknown rounding mode: %ld\n", (LI)set->round);
378
            #endif
379
            break;}
380
          } /* switch (not r-h-e) */
381
        /* printf("ReRound: %ld  bump: %ld\n", (LI)reround, (LI)bump); */
382
 
383
        if (bump!=0) {                        /* need increment */
384
          /* increment the coefficient; this might end up with 1000... */
385
          /* (after the all nines case) */
386
          ub=ulsd;
387
          for(; ub-3>=umsd && UBTOUI(ub-3)==0x09090909; ub-=4)  {
388
            UBFROMUI(ub-3, 0);                /* to 00000000 */
389
            }
390
          /* [note ub could now be to left of msd, and it is not safe */
391
          /* to write to the the left of the msd] */
392
          /* now at most 3 digits left to non-9 (usually just the one) */
393
          for (; ub>=umsd; *ub=0, ub--) {
394
            if (*ub==9) continue;            /* carry */
395
            *ub+=1;
396
            break;
397
            }
398
          if (ub<umsd) {                     /* had all-nines */
399
            *umsd=1;                         /* coefficient to 1000... */
400
            /* usually the 1000... coefficient can be used as-is */
401
            if ((ulsd-umsd+1)==DECPMAX) {
402
              num->exponent++;
403
              }
404
             else {
405
              /* if coefficient is shorter than Pmax then num is */
406
              /* subnormal, so extend it; this is safe as drop>0 */
407
              /* (or, if the coefficient was supplied above, it could */
408
              /* not be 9); this may make the result normal. */
409
              ulsd++;
410
              *ulsd=0;
411
              /* [exponent unchanged] */
412
              #if DECCHECK
413
              if (num->exponent!=DECQTINY) /* sanity check */
414
                printf("decFinalize: bad all-nines extend [^%ld, %ld]\n",
415
                       (LI)num->exponent, (LI)(ulsd-umsd+1));
416
              #endif
417
              } /* subnormal extend */
418
            } /* had all-nines */
419
          } /* bump needed */
420
        } /* inexact rounding */
421
 
422
      length=ulsd-umsd+1;               /* recalculate (may be <DECPMAX) */
423
      } /* need round (drop>0) */
424
 
425
    /* The coefficient will now fit and has final length unless overflow */
426
    /* decShowNum(num, "rounded"); */
427
 
428
    /* if exponent is >=emax may have to clamp, overflow, or fold-down */
429
    if (num->exponent>DECEMAX-(DECPMAX-1)) { /* is edge case */
430
      /* printf("overflow checks...\n"); */
431
      if (*ulsd==0 && ulsd==umsd) {      /* have zero */
432
        num->exponent=DECEMAX-(DECPMAX-1); /* clamp to max */
433
        }
434
       else if ((num->exponent+length-1)>DECEMAX) { /* > Nmax */
435
        /* Overflow -- these could go straight to encoding, here, but */
436
        /* instead num is adjusted to keep the code cleaner */
437
        Flag needmax=0;          /* 1 for finite result */
438
        set->status|=(DEC_Overflow | DEC_Inexact);
439
        switch (set->round) {
440
          case DEC_ROUND_DOWN: {
441
            needmax=1;                  /* never Infinity */
442
            break;} /* r-d */
443
          case DEC_ROUND_05UP: {
444
            needmax=1;                  /* never Infinity */
445
            break;} /* r-05 */
446
          case DEC_ROUND_CEILING: {
447
            if (num->sign) needmax=1;   /* Infinity iff non-negative */
448
            break;} /* r-c */
449
          case DEC_ROUND_FLOOR: {
450
            if (!num->sign) needmax=1;  /* Infinity iff negative */
451
            break;} /* r-f */
452
          default: break;               /* Infinity in all other cases */
453
          }
454
        if (!needmax) {                 /* easy .. set Infinity */
455
          num->exponent=DECFLOAT_Inf;
456
          *umsd=0;                       /* be clean: coefficient to 0 */
457
          ulsd=umsd;                    /* .. */
458
          }
459
         else {                         /* return Nmax */
460
          umsd=allnines;                /* use constant array */
461
          ulsd=allnines+DECPMAX-1;
462
          num->exponent=DECEMAX-(DECPMAX-1);
463
          }
464
        }
465
       else { /* no overflow but non-zero and may have to fold-down */
466
        Int shift=num->exponent-(DECEMAX-(DECPMAX-1));
467
        if (shift>0) {                   /* fold-down needed */
468
          /* fold down needed; must copy to buffer in order to pad */
469
          /* with zeros safely; fortunately this is not the worst case */
470
          /* path because cannot have had a round */
471
          uByte buffer[ROUNDUP(DECPMAX+3, 4)]; /* [+3 allows uInt padding] */
472
          uByte *s=umsd;                /* source */
473
          uByte *t=buffer;              /* safe target */
474
          uByte *tlsd=buffer+(ulsd-umsd)+shift; /* target LSD */
475
          /* printf("folddown shift=%ld\n", (LI)shift); */
476
          for (; s<=ulsd; s+=4, t+=4) UBFROMUI(t, UBTOUI(s));
477
          for (t=tlsd-shift+1; t<=tlsd; t+=4) UBFROMUI(t, 0);  /* pad 0s */
478
          num->exponent-=shift;
479
          umsd=buffer;
480
          ulsd=tlsd;
481
          }
482
        } /* fold-down? */
483
      length=ulsd-umsd+1;               /* recalculate length */
484
      } /* high-end edge case */
485
    } /* finite number */
486
 
487
  /*------------------------------------------------------------------*/
488
  /* At this point the result will properly fit the decFloat          */
489
  /* encoding, and it can be encoded with no possibility of error     */
490
  /*------------------------------------------------------------------*/
491
  /* Following code does not alter coefficient (could be allnines array) */
492
 
493
  /* fast path possible when DECPMAX digits */
494
  if (length==DECPMAX) {
495
    return decFloatFromBCD(df, num->exponent, umsd, num->sign);
496
    } /* full-length */
497
 
498
  /* slower path when not a full-length number; must care about length */
499
  /* [coefficient length here will be < DECPMAX] */
500
  if (!NUMISSPECIAL(num)) {             /* is still finite */
501
    /* encode the combination field and exponent continuation */
502
    uInt uexp=(uInt)(num->exponent+DECBIAS); /* biased exponent */
503
    uInt code=(uexp>>DECECONL)<<4;      /* top two bits of exp */
504
    /* [msd==0] */
505
    /* look up the combination field and make high word */
506
    encode=DECCOMBFROM[code];           /* indexed by (0-2)*16+msd */
507
    encode|=(uexp<<(32-6-DECECONL)) & 0x03ffffff; /* exponent continuation */
508
    }
509
   else encode=num->exponent;           /* special [already in word] */
510
  encode|=num->sign;                    /* add sign */
511
 
512
  /* private macro to extract a declet, n (where 0<=n<DECLETS and 0 */
513
  /* refers to the declet from the least significant three digits) */
514
  /* and put the corresponding DPD code into dpd.  Access to umsd and */
515
  /* ulsd (pointers to the most and least significant digit of the */
516
  /* variable-length coefficient) is assumed, along with use of a */
517
  /* working pointer, uInt *ub. */
518
  /* As not full-length then chances are there are many leading zeros */
519
  /* [and there may be a partial triad] */
520
  #define getDPDt(dpd, n) ub=ulsd-(3*(n))-2;                          \
521
    if (ub<umsd-2) dpd=0;                                              \
522
     else if (ub>=umsd) dpd=BCD2DPD[(*ub*256)+(*(ub+1)*16)+*(ub+2)];  \
523
     else {dpd=*(ub+2); if (ub+1==umsd) dpd+=*(ub+1)*16; dpd=BCD2DPD[dpd];}
524
 
525
  /* place the declets in the encoding words and copy to result (df), */
526
  /* according to endianness; in all cases complete the sign word */
527
  /* first */
528
  #if DECPMAX==7
529
    getDPDt(dpd, 1);
530
    encode|=dpd<<10;
531
    getDPDt(dpd, 0);
532
    encode|=dpd;
533
    DFWORD(df, 0)=encode;     /* just the one word */
534
 
535
  #elif DECPMAX==16
536
    getDPDt(dpd, 4); encode|=dpd<<8;
537
    getDPDt(dpd, 3); encode|=dpd>>2;
538
    DFWORD(df, 0)=encode;
539
    encode=dpd<<30;
540
    getDPDt(dpd, 2); encode|=dpd<<20;
541
    getDPDt(dpd, 1); encode|=dpd<<10;
542
    getDPDt(dpd, 0); encode|=dpd;
543
    DFWORD(df, 1)=encode;
544
 
545
  #elif DECPMAX==34
546
    getDPDt(dpd,10); encode|=dpd<<4;
547
    getDPDt(dpd, 9); encode|=dpd>>6;
548
    DFWORD(df, 0)=encode;
549
 
550
    encode=dpd<<26;
551
    getDPDt(dpd, 8); encode|=dpd<<16;
552
    getDPDt(dpd, 7); encode|=dpd<<6;
553
    getDPDt(dpd, 6); encode|=dpd>>4;
554
    DFWORD(df, 1)=encode;
555
 
556
    encode=dpd<<28;
557
    getDPDt(dpd, 5); encode|=dpd<<18;
558
    getDPDt(dpd, 4); encode|=dpd<<8;
559
    getDPDt(dpd, 3); encode|=dpd>>2;
560
    DFWORD(df, 2)=encode;
561
 
562
    encode=dpd<<30;
563
    getDPDt(dpd, 2); encode|=dpd<<20;
564
    getDPDt(dpd, 1); encode|=dpd<<10;
565
    getDPDt(dpd, 0); encode|=dpd;
566
    DFWORD(df, 3)=encode;
567
  #endif
568
 
569
  /* printf("Status: %08lx\n", (LI)set->status); */
570
  /* decFloatShow(df, "final2"); */
571
  return df;
572
  } /* decFinalize */
573
 
574
/* ------------------------------------------------------------------ */
575
/* decFloatFromBCD -- set decFloat from exponent, BCD8, and sign      */
576
/*                                                                    */
577
/*  df is the target decFloat                                         */
578
/*  exp is the in-range unbiased exponent, q, or a special value in   */
579
/*    the form returned by decFloatGetExponent                        */
580
/*  bcdar holds DECPMAX digits to set the coefficient from, one       */
581
/*    digit in each byte (BCD8 encoding); the first (MSD) is ignored  */
582
/*    if df is a NaN; all are ignored if df is infinite.              */
583
/*    All bytes must be in 0-9; results are undefined otherwise.      */
584
/*  sig is DECFLOAT_Sign to set the sign bit, 0 otherwise             */
585
/*  returns df, which will be canonical                               */
586
/*                                                                    */
587
/* No error is possible, and no status will be set.                   */
588
/* ------------------------------------------------------------------ */
589
decFloat * decFloatFromBCD(decFloat *df, Int exp, const uByte *bcdar,
590
                           Int sig) {
591
  uInt encode, dpd;                     /* work */
592
  const uByte *ub;                      /* .. */
593
 
594
  if (EXPISSPECIAL(exp)) encode=exp|sig;/* specials already encoded */
595
   else {                               /* is finite */
596
    /* encode the combination field and exponent continuation */
597
    uInt uexp=(uInt)(exp+DECBIAS);      /* biased exponent */
598
    uInt code=(uexp>>DECECONL)<<4;      /* top two bits of exp */
599
    code+=bcdar[0];                      /* add msd */
600
    /* look up the combination field and make high word */
601
    encode=DECCOMBFROM[code]|sig;       /* indexed by (0-2)*16+msd */
602
    encode|=(uexp<<(32-6-DECECONL)) & 0x03ffffff; /* exponent continuation */
603
    }
604
 
605
  /* private macro to extract a declet, n (where 0<=n<DECLETS and 0 */
606
  /* refers to the declet from the least significant three digits) */
607
  /* and put the corresponding DPD code into dpd. */
608
  /* Use of a working pointer, uInt *ub, is assumed. */
609
 
610
  #define getDPDb(dpd, n) ub=bcdar+DECPMAX-1-(3*(n))-2;     \
611
    dpd=BCD2DPD[(*ub*256)+(*(ub+1)*16)+*(ub+2)];
612
 
613
  /* place the declets in the encoding words and copy to result (df), */
614
  /* according to endianness; in all cases complete the sign word */
615
  /* first */
616
  #if DECPMAX==7
617
    getDPDb(dpd, 1);
618
    encode|=dpd<<10;
619
    getDPDb(dpd, 0);
620
    encode|=dpd;
621
    DFWORD(df, 0)=encode;     /* just the one word */
622
 
623
  #elif DECPMAX==16
624
    getDPDb(dpd, 4); encode|=dpd<<8;
625
    getDPDb(dpd, 3); encode|=dpd>>2;
626
    DFWORD(df, 0)=encode;
627
    encode=dpd<<30;
628
    getDPDb(dpd, 2); encode|=dpd<<20;
629
    getDPDb(dpd, 1); encode|=dpd<<10;
630
    getDPDb(dpd, 0); encode|=dpd;
631
    DFWORD(df, 1)=encode;
632
 
633
  #elif DECPMAX==34
634
    getDPDb(dpd,10); encode|=dpd<<4;
635
    getDPDb(dpd, 9); encode|=dpd>>6;
636
    DFWORD(df, 0)=encode;
637
 
638
    encode=dpd<<26;
639
    getDPDb(dpd, 8); encode|=dpd<<16;
640
    getDPDb(dpd, 7); encode|=dpd<<6;
641
    getDPDb(dpd, 6); encode|=dpd>>4;
642
    DFWORD(df, 1)=encode;
643
 
644
    encode=dpd<<28;
645
    getDPDb(dpd, 5); encode|=dpd<<18;
646
    getDPDb(dpd, 4); encode|=dpd<<8;
647
    getDPDb(dpd, 3); encode|=dpd>>2;
648
    DFWORD(df, 2)=encode;
649
 
650
    encode=dpd<<30;
651
    getDPDb(dpd, 2); encode|=dpd<<20;
652
    getDPDb(dpd, 1); encode|=dpd<<10;
653
    getDPDb(dpd, 0); encode|=dpd;
654
    DFWORD(df, 3)=encode;
655
  #endif
656
  /* decFloatShow(df, "fromB"); */
657
  return df;
658
  } /* decFloatFromBCD */
659
 
660
/* ------------------------------------------------------------------ */
661
/* decFloatFromPacked -- set decFloat from exponent and packed BCD    */
662
/*                                                                    */
663
/*  df is the target decFloat                                         */
664
/*  exp is the in-range unbiased exponent, q, or a special value in   */
665
/*    the form returned by decFloatGetExponent                        */
666
/*  packed holds DECPMAX packed decimal digits plus a sign nibble     */
667
/*    (all 6 codes are OK); the first (MSD) is ignored if df is a NaN */
668
/*    and all except sign are ignored if df is infinite.  For DOUBLE  */
669
/*    and QUAD the first (pad) nibble is also ignored in all cases.   */
670
/*    All coefficient nibbles must be in 0-9 and sign in A-F; results */
671
/*    are undefined otherwise.                                        */
672
/*  returns df, which will be canonical                               */
673
/*                                                                    */
674
/* No error is possible, and no status will be set.                   */
675
/* ------------------------------------------------------------------ */
676
decFloat * decFloatFromPacked(decFloat *df, Int exp, const uByte *packed) {
677
  uByte bcdar[DECPMAX+2];               /* work [+1 for pad, +1 for sign] */
678
  const uByte *ip;                      /* .. */
679
  uByte *op;                            /* .. */
680
  Int   sig=0;                           /* sign */
681
 
682
  /* expand coefficient and sign to BCDAR */
683
  #if SINGLE
684
  op=bcdar+1;                           /* no pad digit */
685
  #else
686
  op=bcdar;                             /* first (pad) digit ignored */
687
  #endif
688
  for (ip=packed; ip<packed+((DECPMAX+2)/2); ip++) {
689
    *op++=*ip>>4;
690
    *op++=(uByte)(*ip&0x0f);            /* [final nibble is sign] */
691
    }
692
  op--;                                 /* -> sign byte */
693
  if (*op==DECPMINUS || *op==DECPMINUSALT) sig=DECFLOAT_Sign;
694
 
695
  if (EXPISSPECIAL(exp)) {              /* Infinity or NaN */
696
    if (!EXPISINF(exp)) bcdar[1]=0;      /* a NaN: ignore MSD */
697
     else memset(bcdar+1, 0, DECPMAX);   /* Infinite: coefficient to 0 */
698
    }
699
  return decFloatFromBCD(df, exp, bcdar+1, sig);
700
  } /* decFloatFromPacked */
701
 
702
/* ------------------------------------------------------------------ */
703
/* decFloatFromPackedChecked -- set from exponent and packed; checked */
704
/*                                                                    */
705
/*  df is the target decFloat                                         */
706
/*  exp is the in-range unbiased exponent, q, or a special value in   */
707
/*    the form returned by decFloatGetExponent                        */
708
/*  packed holds DECPMAX packed decimal digits plus a sign nibble     */
709
/*    (all 6 codes are OK); the first (MSD) must be 0 if df is a NaN  */
710
/*    and all digits must be 0 if df is infinite.  For DOUBLE and     */
711
/*    QUAD the first (pad) nibble must be 0.                          */
712
/*    All coefficient nibbles must be in 0-9 and sign in A-F.         */
713
/*  returns df, which will be canonical or NULL if any of the         */
714
/*    requirements are not met (if this case df is unchanged); that   */
715
/*    is, the input data must be as returned by decFloatToPacked,     */
716
/*    except that all six sign codes are acccepted.                   */
717
/*                                                                    */
718
/* No status will be set.                                             */
719
/* ------------------------------------------------------------------ */
720
decFloat * decFloatFromPackedChecked(decFloat *df, Int exp,
721
                                     const uByte *packed) {
722
  uByte bcdar[DECPMAX+2];               /* work [+1 for pad, +1 for sign] */
723
  const uByte *ip;                      /* .. */
724
  uByte *op;                            /* .. */
725
  Int   sig=0;                           /* sign */
726
 
727
  /* expand coefficient and sign to BCDAR */
728
  #if SINGLE
729
  op=bcdar+1;                           /* no pad digit */
730
  #else
731
  op=bcdar;                             /* first (pad) digit here */
732
  #endif
733
  for (ip=packed; ip<packed+((DECPMAX+2)/2); ip++) {
734
    *op=*ip>>4;
735
    if (*op>9) return NULL;
736
    op++;
737
    *op=(uByte)(*ip&0x0f);              /* [final nibble is sign] */
738
    if (*op>9 && ip<packed+((DECPMAX+2)/2)-1) return NULL;
739
    op++;
740
    }
741
  op--;                                 /* -> sign byte */
742
  if (*op<=9) return NULL;              /* bad sign */
743
  if (*op==DECPMINUS || *op==DECPMINUSALT) sig=DECFLOAT_Sign;
744
 
745
  #if !SINGLE
746
  if (bcdar[0]!=0) return NULL;   /* bad pad nibble */
747
  #endif
748
 
749
  if (EXPISNAN(exp)) {                  /* a NaN */
750
    if (bcdar[1]!=0) return NULL;        /* bad msd */
751
    } /* NaN */
752
   else if (EXPISINF(exp)) {            /* is infinite */
753
    Int i;
754
    for (i=0; i<DECPMAX; i++) {
755
      if (bcdar[i+1]!=0) return NULL;    /* should be all zeros */
756
      }
757
    } /* infinity */
758
   else {                               /* finite */
759
    /* check the exponent is in range */
760
    if (exp>DECEMAX-DECPMAX+1) return NULL;
761
    if (exp<DECEMIN-DECPMAX+1) return NULL;
762
    }
763
  return decFloatFromBCD(df, exp, bcdar+1, sig);
764
  } /* decFloatFromPacked */
765
 
766
/* ------------------------------------------------------------------ */
767
/* decFloatFromString -- conversion from numeric string               */
768
/*                                                                    */
769
/*  result  is the decFloat format number which gets the result of    */
770
/*          the conversion                                            */
771
/*  *string is the character string which should contain a valid      */
772
/*          number (which may be a special value), \0-terminated      */
773
/*          If there are too many significant digits in the           */
774
/*          coefficient it will be rounded.                           */
775
/*  set     is the context                                            */
776
/*  returns result                                                    */
777
/*                                                                    */
778
/* The length of the coefficient and the size of the exponent are     */
779
/* checked by this routine, so the correct error (Underflow or        */
780
/* Overflow) can be reported or rounding applied, as necessary.       */
781
/*                                                                    */
782
/* There is no limit to the coefficient length for finite inputs;     */
783
/* NaN payloads must be integers with no more than DECPMAX-1 digits.  */
784
/* Exponents may have up to nine significant digits.                  */
785
/*                                                                    */
786
/* If bad syntax is detected, the result will be a quiet NaN.         */
787
/* ------------------------------------------------------------------ */
788
decFloat * decFloatFromString(decFloat *result, const char *string,
789
                              decContext *set) {
790
  Int    digits;                   /* count of digits in coefficient */
791
  const  char *dotchar=NULL;       /* where dot was found [NULL if none] */
792
  const  char *cfirst=string;      /* -> first character of decimal part */
793
  const  char *c;                  /* work */
794
  uByte *ub;                       /* .. */
795
  uInt   uiwork;                   /* for macros */
796
  bcdnum num;                      /* collects data for finishing */
797
  uInt   error=DEC_Conversion_syntax;   /* assume the worst */
798
  uByte  buffer[ROUNDUP(DECSTRING+11, 8)]; /* room for most coefficents, */
799
                                   /* some common rounding, +3, & pad */
800
  #if DECTRACE
801
  /* printf("FromString %s ...\n", string); */
802
  #endif
803
 
804
  for(;;) {                             /* once-only 'loop' */
805
    num.sign=0;                  /* assume non-negative */
806
    num.msd=buffer;                     /* MSD is here always */
807
 
808
    /* detect and validate the coefficient, including any leading, */
809
    /* trailing, or embedded '.' */
810
    /* [could test four-at-a-time here (saving 10% for decQuads), */
811
    /* but that risks storage violation because the position of the */
812
    /* terminator is unknown] */
813
    for (c=string;; c++) {              /* -> input character */
814
      if (((unsigned)(*c-'0'))<=9) continue; /* '0' through '9' is good */
815
      if (*c=='\0') break;              /* most common non-digit */
816
      if (*c=='.') {
817
        if (dotchar!=NULL) break;       /* not first '.' */
818
        dotchar=c;                      /* record offset into decimal part */
819
        continue;}
820
      if (c==string) {                  /* first in string... */
821
        if (*c=='-') {                  /* valid - sign */
822
          cfirst++;
823
          num.sign=DECFLOAT_Sign;
824
          continue;}
825
        if (*c=='+') {                  /* valid + sign */
826
          cfirst++;
827
          continue;}
828
        }
829
      /* *c is not a digit, terminator, or a valid +, -, or '.' */
830
      break;
831
      } /* c loop */
832
 
833
    digits=(uInt)(c-cfirst);            /* digits (+1 if a dot) */
834
 
835
    if (digits>0) {                      /* had digits and/or dot */
836
      const char *clast=c-1;            /* note last coefficient char position */
837
      Int exp=0;                 /* exponent accumulator */
838
      if (*c!='\0') {                   /* something follows the coefficient */
839
        uInt edig;                      /* unsigned work */
840
        /* had some digits and more to come; expect E[+|-]nnn now */
841
        const char *firstexp;           /* exponent first non-zero */
842
        if (*c!='E' && *c!='e') break;
843
        c++;                            /* to (optional) sign */
844
        if (*c=='-' || *c=='+') c++;    /* step over sign (c=clast+2) */
845
        if (*c=='\0') break;            /* no digits!  (e.g., '1.2E') */
846
        for (; *c=='0';) c++;           /* skip leading zeros [even last] */
847
        firstexp=c;                     /* remember start [maybe '\0'] */
848
        /* gather exponent digits */
849
        edig=(uInt)*c-(uInt)'0';
850
        if (edig<=9) {                  /* [check not bad or terminator] */
851
          exp+=edig;                    /* avoid initial X10 */
852
          c++;
853
          for (;; c++) {
854
            edig=(uInt)*c-(uInt)'0';
855
            if (edig>9) break;
856
            exp=exp*10+edig;
857
            }
858
          }
859
        /* if not now on the '\0', *c must not be a digit */
860
        if (*c!='\0') break;
861
 
862
        /* (this next test must be after the syntax checks) */
863
        /* if definitely more than the possible digits for format then */
864
        /* the exponent may have wrapped, so simply set it to a certain */
865
        /* over/underflow value */
866
        if (c>firstexp+DECEMAXD) exp=DECEMAX*2;
867
        if (*(clast+2)=='-') exp=-exp;  /* was negative */
868
        } /* digits>0 */
869
 
870
      if (dotchar!=NULL) {              /* had a '.' */
871
        digits--;                       /* remove from digits count */
872
        if (digits==0) break;            /* was dot alone: bad syntax */
873
        exp-=(Int)(clast-dotchar);      /* adjust exponent */
874
        /* [the '.' can now be ignored] */
875
        }
876
      num.exponent=exp;                 /* exponent is good; store it */
877
 
878
      /* Here when whole string has been inspected and syntax is good */
879
      /* cfirst->first digit or dot, clast->last digit or dot */
880
      error=0;                           /* no error possible now */
881
 
882
      /* if the number of digits in the coefficient will fit in buffer */
883
      /* then it can simply be converted to bcd8 and copied -- decFinalize */
884
      /* will take care of leading zeros and rounding; the buffer is big */
885
      /* enough for all canonical coefficients, including 0.00000nn... */
886
      ub=buffer;
887
      if (digits<=(Int)(sizeof(buffer)-3)) { /* [-3 allows by-4s copy] */
888
        c=cfirst;
889
        if (dotchar!=NULL) {                 /* a dot to worry about */
890
          if (*(c+1)=='.') {                 /* common canonical case */
891
            *ub++=(uByte)(*c-'0');           /* copy leading digit */
892
            c+=2;                            /* prepare to handle rest */
893
            }
894
           else for (; c<=clast;) {          /* '.' could be anywhere */
895
            /* as usual, go by fours when safe; NB it has been asserted */
896
            /* that a '.' does not have the same mask as a digit */
897
            if (c<=clast-3                             /* safe for four */
898
             && (UBTOUI(c)&0xf0f0f0f0)==CHARMASK) {    /* test four */
899
              UBFROMUI(ub, UBTOUI(c)&0x0f0f0f0f);      /* to BCD8 */
900
              ub+=4;
901
              c+=4;
902
              continue;
903
              }
904
            if (*c=='.') {                   /* found the dot */
905
              c++;                           /* step over it .. */
906
              break;                         /* .. and handle the rest */
907
              }
908
            *ub++=(uByte)(*c++-'0');
909
            }
910
          } /* had dot */
911
        /* Now no dot; do this by fours (where safe) */
912
        for (; c<=clast-3; c+=4, ub+=4) UBFROMUI(ub, UBTOUI(c)&0x0f0f0f0f);
913
        for (; c<=clast; c++, ub++) *ub=(uByte)(*c-'0');
914
        num.lsd=buffer+digits-1;             /* record new LSD */
915
        } /* fits */
916
 
917
       else {                                /* too long for buffer */
918
        /* [This is a rare and unusual case; arbitrary-length input] */
919
        /* strip leading zeros [but leave final 0 if all 0's] */
920
        if (*cfirst=='.') cfirst++;          /* step past dot at start */
921
        if (*cfirst=='0') {                  /* [cfirst always -> digit] */
922
          for (; cfirst<clast; cfirst++) {
923
            if (*cfirst!='0') {              /* non-zero found */
924
              if (*cfirst=='.') continue;    /* [ignore] */
925
              break;                         /* done */
926
              }
927
            digits--;                        /* 0 stripped */
928
            } /* cfirst */
929
          } /* at least one leading 0 */
930
 
931
        /* the coefficient is now as short as possible, but may still */
932
        /* be too long; copy up to Pmax+1 digits to the buffer, then */
933
        /* just record any non-zeros (set round-for-reround digit) */
934
        for (c=cfirst; c<=clast && ub<=buffer+DECPMAX; c++) {
935
          /* (see commentary just above) */
936
          if (c<=clast-3                          /* safe for four */
937
           && (UBTOUI(c)&0xf0f0f0f0)==CHARMASK) { /* four digits */
938
            UBFROMUI(ub, UBTOUI(c)&0x0f0f0f0f);   /* to BCD8 */
939
            ub+=4;
940
            c+=3;                            /* [will become 4] */
941
            continue;
942
            }
943
          if (*c=='.') continue;             /* [ignore] */
944
          *ub++=(uByte)(*c-'0');
945
          }
946
        ub--;                                /* -> LSD */
947
        for (; c<=clast; c++) {              /* inspect remaining chars */
948
          if (*c!='0') {                     /* sticky bit needed */
949
            if (*c=='.') continue;           /* [ignore] */
950
            *ub=DECSTICKYTAB[*ub];           /* update round-for-reround */
951
            break;                           /* no need to look at more */
952
            }
953
          }
954
        num.lsd=ub;                          /* record LSD */
955
        /* adjust exponent for dropped digits */
956
        num.exponent+=digits-(Int)(ub-buffer+1);
957
        } /* too long for buffer */
958
      } /* digits or dot */
959
 
960
     else {                             /* no digits or dot were found */
961
      if (*c=='\0') break;              /* nothing to come is bad */
962
      /* only Infinities and NaNs are allowed, here */
963
      buffer[0]=0;                        /* default a coefficient of 0 */
964
      num.lsd=buffer;                   /* .. */
965
      if (decBiStr(c, "infinity", "INFINITY")
966
       || decBiStr(c, "inf", "INF")) num.exponent=DECFLOAT_Inf;
967
       else {                           /* should be a NaN */
968
        num.exponent=DECFLOAT_qNaN;     /* assume quiet NaN */
969
        if (*c=='s' || *c=='S') {       /* probably an sNaN */
970
          c++;
971
          num.exponent=DECFLOAT_sNaN;   /* assume is in fact sNaN */
972
          }
973
        if (*c!='N' && *c!='n') break;  /* check caseless "NaN" */
974
        c++;
975
        if (*c!='a' && *c!='A') break;  /* .. */
976
        c++;
977
        if (*c!='N' && *c!='n') break;  /* .. */
978
        c++;
979
        /* now either nothing, or nnnn payload (no dots), expected */
980
        /* -> start of integer, and skip leading 0s [including plain 0] */
981
        for (cfirst=c; *cfirst=='0';) cfirst++;
982
        if (*cfirst!='\0') {            /* not empty or all-0, payload */
983
          /* payload found; check all valid digits and copy to buffer as bcd8 */
984
          ub=buffer;
985
          for (c=cfirst;; c++, ub++) {
986
            if ((unsigned)(*c-'0')>9) break; /* quit if not 0-9 */
987
            if (c-cfirst==DECPMAX-1) break;  /* too many digits */
988
            *ub=(uByte)(*c-'0');        /* good bcd8 */
989
            }
990
          if (*c!='\0') break;          /* not all digits, or too many */
991
          num.lsd=ub-1;                 /* record new LSD */
992
          }
993
        } /* NaN or sNaN */
994
      error=0;                           /* syntax is OK */
995
      break;                            /* done with specials */
996
      } /* digits=0 (special expected) */
997
    break;
998
    }                                   /* [for(;;) break] */
999
 
1000
  /* decShowNum(&num, "fromStr"); */
1001
 
1002
  if (error!=0) {
1003
    set->status|=error;
1004
    num.exponent=DECFLOAT_qNaN;         /* set up quiet NaN */
1005
    num.sign=0;                  /* .. with 0 sign */
1006
    buffer[0]=0;                  /* .. and coefficient */
1007
    num.lsd=buffer;                     /* .. */
1008
    /* decShowNum(&num, "oops"); */
1009
    }
1010
 
1011
  /* decShowNum(&num, "dffs"); */
1012
  decFinalize(result, &num, set);       /* round, check, and lay out */
1013
  /* decFloatShow(result, "fromString"); */
1014
  return result;
1015
  } /* decFloatFromString */
1016
 
1017
/* ------------------------------------------------------------------ */
1018
/* decFloatFromWider -- conversion from next-wider format             */
1019
/*                                                                    */
1020
/*  result  is the decFloat format number which gets the result of    */
1021
/*          the conversion                                            */
1022
/*  wider   is the decFloatWider format number which will be narrowed */
1023
/*  set     is the context                                            */
1024
/*  returns result                                                    */
1025
/*                                                                    */
1026
/* Narrowing can cause rounding, overflow, etc., but not Invalid      */
1027
/* operation (sNaNs are copied and do not signal).                    */
1028
/* ------------------------------------------------------------------ */
1029
/* narrow-to is not possible for decQuad format numbers; simply omit */
1030
#if !QUAD
1031
decFloat * decFloatFromWider(decFloat *result, const decFloatWider *wider,
1032
                             decContext *set) {
1033
  bcdnum num;                           /* collects data for finishing */
1034
  uByte  bcdar[DECWPMAX];               /* room for wider coefficient */
1035
  uInt   widerhi=DFWWORD(wider, 0);      /* top word */
1036
  Int    exp;
1037
 
1038
  GETWCOEFF(wider, bcdar);
1039
 
1040
  num.msd=bcdar;                        /* MSD is here always */
1041
  num.lsd=bcdar+DECWPMAX-1;             /* LSD is here always */
1042
  num.sign=widerhi&0x80000000;          /* extract sign [DECFLOAT_Sign=Neg] */
1043
 
1044
  /* decode the wider combination field to exponent */
1045
  exp=DECCOMBWEXP[widerhi>>26];         /* decode from wider combination field */
1046
  /* if it is a special there's nothing to do unless sNaN; if it's */
1047
  /* finite then add the (wider) exponent continuation and unbias */
1048
  if (EXPISSPECIAL(exp)) exp=widerhi&0x7e000000; /* include sNaN selector */
1049
   else exp+=GETWECON(wider)-DECWBIAS;
1050
  num.exponent=exp;
1051
 
1052
  /* decShowNum(&num, "dffw"); */
1053
  return decFinalize(result, &num, set);/* round, check, and lay out */
1054
  } /* decFloatFromWider */
1055
#endif
1056
 
1057
/* ------------------------------------------------------------------ */
1058
/* decFloatGetCoefficient -- get coefficient as BCD8                  */
1059
/*                                                                    */
1060
/*  df is the decFloat from which to extract the coefficient          */
1061
/*  bcdar is where DECPMAX bytes will be written, one BCD digit in    */
1062
/*    each byte (BCD8 encoding); if df is a NaN the first byte will   */
1063
/*    be zero, and if it is infinite they will all be zero            */
1064
/*  returns the sign of the coefficient (DECFLOAT_Sign if negative,   */
1065
/*    0 otherwise)                                                    */
1066
/*                                                                    */
1067
/* No error is possible, and no status will be set.  If df is a       */
1068
/* special value the array is set to zeros (for Infinity) or to the   */
1069
/* payload of a qNaN or sNaN.                                         */
1070
/* ------------------------------------------------------------------ */
1071
Int decFloatGetCoefficient(const decFloat *df, uByte *bcdar) {
1072
  if (DFISINF(df)) memset(bcdar, 0, DECPMAX);
1073
   else {
1074
    GETCOEFF(df, bcdar);           /* use macro */
1075
    if (DFISNAN(df)) bcdar[0]=0;   /* MSD needs correcting */
1076
    }
1077
  return DFISSIGNED(df);
1078
  } /* decFloatGetCoefficient */
1079
 
1080
/* ------------------------------------------------------------------ */
1081
/* decFloatGetExponent -- get unbiased exponent                       */
1082
/*                                                                    */
1083
/*  df is the decFloat from which to extract the exponent             */
1084
/*  returns the exponent, q.                                          */
1085
/*                                                                    */
1086
/* No error is possible, and no status will be set.  If df is a       */
1087
/* special value the first seven bits of the decFloat are returned,   */
1088
/* left adjusted and with the first (sign) bit set to 0 (followed by  */
1089
/* 25 0 bits).  e.g., -sNaN would return 0x7e000000 (DECFLOAT_sNaN).  */
1090
/* ------------------------------------------------------------------ */
1091
Int decFloatGetExponent(const decFloat *df) {
1092
  if (DFISSPECIAL(df)) return DFWORD(df, 0)&0x7e000000;
1093
  return GETEXPUN(df);
1094
  } /* decFloatGetExponent */
1095
 
1096
/* ------------------------------------------------------------------ */
1097
/* decFloatSetCoefficient -- set coefficient from BCD8                */
1098
/*                                                                    */
1099
/*  df is the target decFloat (and source of exponent/special value)  */
1100
/*  bcdar holds DECPMAX digits to set the coefficient from, one       */
1101
/*    digit in each byte (BCD8 encoding); the first (MSD) is ignored  */
1102
/*    if df is a NaN; all are ignored if df is infinite.              */
1103
/*  sig is DECFLOAT_Sign to set the sign bit, 0 otherwise             */
1104
/*  returns df, which will be canonical                               */
1105
/*                                                                    */
1106
/* No error is possible, and no status will be set.                   */
1107
/* ------------------------------------------------------------------ */
1108
decFloat * decFloatSetCoefficient(decFloat *df, const uByte *bcdar,
1109
                                  Int sig) {
1110
  uInt exp;                        /* for exponent */
1111
  uByte bcdzero[DECPMAX];          /* for infinities */
1112
 
1113
  /* Exponent/special code is extracted from df */
1114
  if (DFISSPECIAL(df)) {
1115
    exp=DFWORD(df, 0)&0x7e000000;
1116
    if (DFISINF(df)) {
1117
      memset(bcdzero, 0, DECPMAX);
1118
      return decFloatFromBCD(df, exp, bcdzero, sig);
1119
      }
1120
    }
1121
   else exp=GETEXPUN(df);
1122
  return decFloatFromBCD(df, exp, bcdar, sig);
1123
  } /* decFloatSetCoefficient */
1124
 
1125
/* ------------------------------------------------------------------ */
1126
/* decFloatSetExponent -- set exponent or special value               */
1127
/*                                                                    */
1128
/*  df  is the target decFloat (and source of coefficient/payload)    */
1129
/*  set is the context for reporting status                           */
1130
/*  exp is the unbiased exponent, q, or a special value in the form   */
1131
/*    returned by decFloatGetExponent                                 */
1132
/*  returns df, which will be canonical                               */
1133
/*                                                                    */
1134
/* No error is possible, but Overflow or Underflow might occur.       */
1135
/* ------------------------------------------------------------------ */
1136
decFloat * decFloatSetExponent(decFloat *df, decContext *set, Int exp) {
1137
  uByte  bcdcopy[DECPMAX];         /* for coefficient */
1138
  bcdnum num;                      /* work */
1139
  num.exponent=exp;
1140
  num.sign=decFloatGetCoefficient(df, bcdcopy); /* extract coefficient */
1141
  if (DFISSPECIAL(df)) {           /* MSD or more needs correcting */
1142
    if (DFISINF(df)) memset(bcdcopy, 0, DECPMAX);
1143
    bcdcopy[0]=0;
1144
    }
1145
  num.msd=bcdcopy;
1146
  num.lsd=bcdcopy+DECPMAX-1;
1147
  return decFinalize(df, &num, set);
1148
  } /* decFloatSetExponent */
1149
 
1150
/* ------------------------------------------------------------------ */
1151
/* decFloatRadix -- returns the base (10)                             */
1152
/*                                                                    */
1153
/*   df is any decFloat of this format                                */
1154
/* ------------------------------------------------------------------ */
1155
uInt decFloatRadix(const decFloat *df) {
1156
  if (df) return 10;                         /* to placate compiler */
1157
  return 10;
1158
  } /* decFloatRadix */
1159
 
1160
#if (DECCHECK || DECTRACE)
1161
/* ------------------------------------------------------------------ */
1162
/* decFloatShow -- printf a decFloat in hexadecimal and decimal       */
1163
/*   df  is the decFloat to show                                      */
1164
/*   tag is a tag string displayed with the number                    */
1165
/*                                                                    */
1166
/* This is a debug aid; the precise format of the string may change.  */
1167
/* ------------------------------------------------------------------ */
1168
void decFloatShow(const decFloat *df, const char *tag) {
1169
  char hexbuf[DECBYTES*2+DECBYTES/4+1]; /* NB blank after every fourth */
1170
  char buff[DECSTRING];                 /* for value in decimal */
1171
  Int i, j=0;
1172
 
1173
  for (i=0; i<DECBYTES; i++) {
1174
    #if DECLITEND
1175
      sprintf(&hexbuf[j], "%02x", df->bytes[DECBYTES-1-i]);
1176
    #else
1177
      sprintf(&hexbuf[j], "%02x", df->bytes[i]);
1178
    #endif
1179
    j+=2;
1180
    /* the next line adds blank (and terminator) after final pair, too */
1181
    if ((i+1)%4==0) {strcpy(&hexbuf[j], " "); j++;}
1182
    }
1183
  decFloatToString(df, buff);
1184
  printf(">%s> %s [big-endian]  %s\n", tag, hexbuf, buff);
1185
  return;
1186
  } /* decFloatShow */
1187
#endif
1188
 
1189
/* ------------------------------------------------------------------ */
1190
/* decFloatToBCD -- get sign, exponent, and BCD8 from a decFloat      */
1191
/*                                                                    */
1192
/*  df is the source decFloat                                         */
1193
/*  exp will be set to the unbiased exponent, q, or to a special      */
1194
/*    value in the form returned by decFloatGetExponent               */
1195
/*  bcdar is where DECPMAX bytes will be written, one BCD digit in    */
1196
/*    each byte (BCD8 encoding); if df is a NaN the first byte will   */
1197
/*    be zero, and if it is infinite they will all be zero            */
1198
/*  returns the sign of the coefficient (DECFLOAT_Sign if negative,   */
1199
/*    0 otherwise)                                                    */
1200
/*                                                                    */
1201
/* No error is possible, and no status will be set.                   */
1202
/* ------------------------------------------------------------------ */
1203
Int decFloatToBCD(const decFloat *df, Int *exp, uByte *bcdar) {
1204
  if (DFISINF(df)) {
1205
    memset(bcdar, 0, DECPMAX);
1206
    *exp=DFWORD(df, 0)&0x7e000000;
1207
    }
1208
   else {
1209
    GETCOEFF(df, bcdar);           /* use macro */
1210
    if (DFISNAN(df)) {
1211
      bcdar[0]=0;            /* MSD needs correcting */
1212
      *exp=DFWORD(df, 0)&0x7e000000;
1213
      }
1214
     else {                        /* finite */
1215
      *exp=GETEXPUN(df);
1216
      }
1217
    }
1218
  return DFISSIGNED(df);
1219
  } /* decFloatToBCD */
1220
 
1221
/* ------------------------------------------------------------------ */
1222
/* decFloatToEngString -- conversion to numeric string, engineering   */
1223
/*                                                                    */
1224
/*  df is the decFloat format number to convert                       */
1225
/*  string is the string where the result will be laid out            */
1226
/*                                                                    */
1227
/* string must be at least DECPMAX+9 characters (the worst case is    */
1228
/* "-0.00000nnn...nnn\0", which is as long as the exponent form when  */
1229
/* DECEMAXD<=4); this condition is asserted above                     */
1230
/*                                                                    */
1231
/* No error is possible, and no status will be set                    */
1232
/* ------------------------------------------------------------------ */
1233
char * decFloatToEngString(const decFloat *df, char *string){
1234
  uInt msd;                        /* coefficient MSD */
1235
  Int  exp;                        /* exponent top two bits or full */
1236
  uInt comb;                       /* combination field */
1237
  char *cstart;                    /* coefficient start */
1238
  char *c;                         /* output pointer in string */
1239
  char *s, *t;                     /* .. (source, target) */
1240
  Int  pre, e;                     /* work */
1241
  const uByte *u;                  /* .. */
1242
  uInt  uiwork;                    /* for macros [one compiler needs */
1243
                                   /* volatile here to avoid bug, but */
1244
                                   /* that doubles execution time] */
1245
 
1246
  /* Source words; macro handles endianness */
1247
  uInt sourhi=DFWORD(df, 0);        /* word with sign */
1248
  #if DECPMAX==16
1249
  uInt sourlo=DFWORD(df, 1);
1250
  #elif DECPMAX==34
1251
  uInt sourmh=DFWORD(df, 1);
1252
  uInt sourml=DFWORD(df, 2);
1253
  uInt sourlo=DFWORD(df, 3);
1254
  #endif
1255
 
1256
  c=string;                        /* where result will go */
1257
  if (((Int)sourhi)<0) *c++='-';   /* handle sign */
1258
  comb=sourhi>>26;                 /* sign+combination field */
1259
  msd=DECCOMBMSD[comb];            /* decode the combination field */
1260
  exp=DECCOMBEXP[comb];            /* .. */
1261
 
1262
  if (EXPISSPECIAL(exp)) {         /* special */
1263
    if (exp==DECFLOAT_Inf) {       /* infinity */
1264
      strcpy(c,   "Inf");
1265
      strcpy(c+3, "inity");
1266
      return string;               /* easy */
1267
      }
1268
    if (sourhi&0x02000000) *c++='s'; /* sNaN */
1269
    strcpy(c, "NaN");              /* complete word */
1270
    c+=3;                          /* step past */
1271
    /* quick exit if the payload is zero */
1272
    #if DECPMAX==7
1273
    if ((sourhi&0x000fffff)==0) return string;
1274
    #elif DECPMAX==16
1275
    if (sourlo==0 && (sourhi&0x0003ffff)==0) return string;
1276
    #elif DECPMAX==34
1277
    if (sourlo==0 && sourml==0 && sourmh==0
1278
     && (sourhi&0x00003fff)==0) return string;
1279
    #endif
1280
    /* otherwise drop through to add integer; set correct exp etc. */
1281
    exp=0; msd=0;            /* setup for following code */
1282
    }
1283
   else { /* complete exponent; top two bits are in place */
1284
    exp+=GETECON(df)-DECBIAS;      /* .. + continuation and unbias */
1285
    }
1286
 
1287
  /* convert the digits of the significand to characters */
1288
  cstart=c;                        /* save start of coefficient */
1289
  if (msd) *c++=(char)('0'+(char)msd);  /* non-zero most significant digit */
1290
 
1291
  /* Decode the declets.  After extracting each declet, it is */
1292
  /* decoded to a 4-uByte sequence by table lookup; the four uBytes */
1293
  /* are the three encoded BCD8 digits followed by a 1-byte length */
1294
  /* (significant digits, except that 000 has length 0).  This allows */
1295
  /* us to left-align the first declet with non-zero content, then */
1296
  /* the remaining ones are full 3-char length.  Fixed-length copies */
1297
  /* are used because variable-length memcpy causes a subroutine call */
1298
  /* in at least two compilers.  (The copies are length 4 for speed */
1299
  /* and are safe because the last item in the array is of length */
1300
  /* three and has the length byte following.) */
1301
  #define dpd2char(dpdin) u=&DPD2BCD8[((dpdin)&0x3ff)*4];        \
1302
         if (c!=cstart) {UBFROMUI(c, UBTOUI(u)|CHARMASK); c+=3;} \
1303
          else if (*(u+3)) {                                     \
1304
           UBFROMUI(c, UBTOUI(u+3-*(u+3))|CHARMASK); c+=*(u+3);}
1305
 
1306
  #if DECPMAX==7
1307
  dpd2char(sourhi>>10);                 /* declet 1 */
1308
  dpd2char(sourhi);                     /* declet 2 */
1309
 
1310
  #elif DECPMAX==16
1311
  dpd2char(sourhi>>8);                  /* declet 1 */
1312
  dpd2char((sourhi<<2) | (sourlo>>30)); /* declet 2 */
1313
  dpd2char(sourlo>>20);                 /* declet 3 */
1314
  dpd2char(sourlo>>10);                 /* declet 4 */
1315
  dpd2char(sourlo);                     /* declet 5 */
1316
 
1317
  #elif DECPMAX==34
1318
  dpd2char(sourhi>>4);                  /* declet 1 */
1319
  dpd2char((sourhi<<6) | (sourmh>>26)); /* declet 2 */
1320
  dpd2char(sourmh>>16);                 /* declet 3 */
1321
  dpd2char(sourmh>>6);                  /* declet 4 */
1322
  dpd2char((sourmh<<4) | (sourml>>28)); /* declet 5 */
1323
  dpd2char(sourml>>18);                 /* declet 6 */
1324
  dpd2char(sourml>>8);                  /* declet 7 */
1325
  dpd2char((sourml<<2) | (sourlo>>30)); /* declet 8 */
1326
  dpd2char(sourlo>>20);                 /* declet 9 */
1327
  dpd2char(sourlo>>10);                 /* declet 10 */
1328
  dpd2char(sourlo);                     /* declet 11 */
1329
  #endif
1330
 
1331
  if (c==cstart) *c++='0';         /* all zeros, empty -- make "0" */
1332
 
1333
  if (exp==0) {             /* integer or NaN case -- easy */
1334
    *c='\0';                       /* terminate */
1335
    return string;
1336
    }
1337
  /* non-0 exponent */
1338
 
1339
  e=0;                              /* assume no E */
1340
  pre=(Int)(c-cstart)+exp;         /* length+exp  [c->LSD+1] */
1341
  /* [here, pre-exp is the digits count (==1 for zero)] */
1342
 
1343
  if (exp>0 || pre<-5) {    /* need exponential form */
1344
    e=pre-1;                       /* calculate E value */
1345
    pre=1;                         /* assume one digit before '.' */
1346
    if (e!=0) {             /* engineering: may need to adjust */
1347
      Int adj;                     /* adjustment */
1348
      /* The C remainder operator is undefined for negative numbers, so */
1349
      /* a positive remainder calculation must be used here */
1350
      if (e<0) {
1351
        adj=(-e)%3;
1352
        if (adj!=0) adj=3-adj;
1353
        }
1354
       else { /* e>0 */
1355
        adj=e%3;
1356
        }
1357
      e=e-adj;
1358
      /* if dealing with zero still produce an exponent which is a */
1359
      /* multiple of three, as expected, but there will only be the */
1360
      /* one zero before the E, still.  Otherwise note the padding. */
1361
      if (!DFISZERO(df)) pre+=adj;
1362
       else {  /* is zero */
1363
        if (adj!=0) {               /* 0.00Esnn needed */
1364
          e=e+3;
1365
          pre=-(2-adj);
1366
          }
1367
        } /* zero */
1368
      } /* engineering adjustment */
1369
    } /* exponential form */
1370
  /* printf("e=%ld pre=%ld exp=%ld\n", (LI)e, (LI)pre, (LI)exp); */
1371
 
1372
  /* modify the coefficient, adding 0s, '.', and E+nn as needed */
1373
  if (pre>0) {                      /* ddd.ddd (plain), perhaps with E */
1374
                                   /* or dd00 padding for engineering */
1375
    char *dotat=cstart+pre;
1376
    if (dotat<c) {                      /* if embedded dot needed... */
1377
      /* move by fours; there must be space for junk at the end */
1378
      /* because there is still space for exponent */
1379
      s=dotat+ROUNDDOWN4(c-dotat);      /* source */
1380
      t=s+1;                            /* target */
1381
      /* open the gap [cannot use memcpy] */
1382
      for (; s>=dotat; s-=4, t-=4) UBFROMUI(t, UBTOUI(s));
1383
      *dotat='.';
1384
      c++;                              /* length increased by one */
1385
      } /* need dot? */
1386
     else for (; c<dotat; c++) *c='0';  /* pad for engineering */
1387
    } /* pre>0 */
1388
   else {
1389
    /* -5<=pre<=0: here for plain 0.ddd or 0.000ddd forms (may have
1390
       E, but only for 0.00E+3 kind of case -- with plenty of spare
1391
       space in this case */
1392
    pre=-pre+2;                         /* gap width, including "0." */
1393
    t=cstart+ROUNDDOWN4(c-cstart)+pre;  /* preferred first target point */
1394
    /* backoff if too far to the right */
1395
    if (t>string+DECSTRING-5) t=string+DECSTRING-5; /* adjust to fit */
1396
    /* now shift the entire coefficient to the right, being careful not */
1397
    /* to access to the left of string [cannot use memcpy] */
1398
    for (s=t-pre; s>=string; s-=4, t-=4) UBFROMUI(t, UBTOUI(s));
1399
    /* for Quads and Singles there may be a character or two left... */
1400
    s+=3;                               /* where next would come from */
1401
    for(; s>=cstart; s--, t--) *(t+3)=*(s);
1402
    /* now have fill 0. through 0.00000; use overlaps to avoid tests */
1403
    if (pre>=4) {
1404
      memcpy(cstart+pre-4, "0000", 4);
1405
      memcpy(cstart, "0.00", 4);
1406
      }
1407
     else { /* 2 or 3 */
1408
      *(cstart+pre-1)='0';
1409
      memcpy(cstart, "0.", 2);
1410
      }
1411
    c+=pre;                             /* to end */
1412
    }
1413
 
1414
  /* finally add the E-part, if needed; it will never be 0, and has */
1415
  /* a maximum length of 3 or 4 digits (asserted above) */
1416
  if (e!=0) {
1417
    memcpy(c, "E+", 2);                 /* starts with E, assume + */
1418
    c++;
1419
    if (e<0) {
1420
      *c='-';                           /* oops, need '-' */
1421
      e=-e;                             /* uInt, please */
1422
      }
1423
    c++;
1424
    /* Three-character exponents are easy; 4-character a little trickier */
1425
    #if DECEMAXD<=3
1426
      u=&BIN2BCD8[e*4];                 /* -> 3 digits + length byte */
1427
      /* copy fixed 4 characters [is safe], starting at non-zero */
1428
      /* and with character mask to convert BCD to char */
1429
      UBFROMUI(c, UBTOUI(u+3-*(u+3))|CHARMASK);
1430
      c+=*(u+3);                        /* bump pointer appropriately */
1431
    #elif DECEMAXD==4
1432
      if (e<1000) {                     /* 3 (or fewer) digits case */
1433
        u=&BIN2BCD8[e*4];               /* -> 3 digits + length byte */
1434
        UBFROMUI(c, UBTOUI(u+3-*(u+3))|CHARMASK); /* [as above] */
1435
        c+=*(u+3);                      /* bump pointer appropriately */
1436
        }
1437
       else {                           /* 4-digits */
1438
        Int thou=((e>>3)*1049)>>17;     /* e/1000 */
1439
        Int rem=e-(1000*thou);          /* e%1000 */
1440
        *c++=(char)('0'+(char)thou);    /* the thousands digit */
1441
        u=&BIN2BCD8[rem*4];             /* -> 3 digits + length byte */
1442
        UBFROMUI(c, UBTOUI(u)|CHARMASK);/* copy fixed 3+1 characters [is safe] */
1443
        c+=3;                           /* bump pointer, always 3 digits */
1444
        }
1445
    #endif
1446
    }
1447
  *c='\0';                              /* terminate */
1448
  /*printf("res %s\n", string); */
1449
  return string;
1450
  } /* decFloatToEngString */
1451
 
1452
/* ------------------------------------------------------------------ */
1453
/* decFloatToPacked -- convert decFloat to Packed decimal + exponent  */
1454
/*                                                                    */
1455
/*  df is the source decFloat                                         */
1456
/*  exp will be set to the unbiased exponent, q, or to a special      */
1457
/*    value in the form returned by decFloatGetExponent               */
1458
/*  packed is where DECPMAX nibbles will be written with the sign as  */
1459
/*    final nibble (0x0c for +, 0x0d for -); a NaN has a first nibble */
1460
/*    of zero, and an infinity is all zeros. decDouble and decQuad    */
1461
/*    have a additional leading zero nibble, leading to result        */
1462
/*    lengths of 4, 9, and 18 bytes.                                  */
1463
/*  returns the sign of the coefficient (DECFLOAT_Sign if negative,   */
1464
/*    0 otherwise)                                                    */
1465
/*                                                                    */
1466
/* No error is possible, and no status will be set.                   */
1467
/* ------------------------------------------------------------------ */
1468
Int decFloatToPacked(const decFloat *df, Int *exp, uByte *packed) {
1469
  uByte bcdar[DECPMAX+2];          /* work buffer */
1470
  uByte *ip=bcdar, *op=packed;     /* work pointers */
1471
  if (DFISINF(df)) {
1472
    memset(bcdar, 0, DECPMAX+2);
1473
    *exp=DECFLOAT_Inf;
1474
    }
1475
   else {
1476
    GETCOEFF(df, bcdar+1);         /* use macro */
1477
    if (DFISNAN(df)) {
1478
      bcdar[1]=0;                   /* MSD needs clearing */
1479
      *exp=DFWORD(df, 0)&0x7e000000;
1480
      }
1481
     else {                        /* finite */
1482
      *exp=GETEXPUN(df);
1483
      }
1484
    }
1485
  /* now pack; coefficient currently at bcdar+1 */
1486
  #if SINGLE
1487
    ip++;                          /* ignore first byte */
1488
  #else
1489
    *ip=0;                          /* need leading zero */
1490
  #endif
1491
  /* set final byte to Packed BCD sign value */
1492
  bcdar[DECPMAX+1]=(DFISSIGNED(df) ? DECPMINUS : DECPPLUS);
1493
  /* pack an even number of bytes... */
1494
  for (; op<packed+((DECPMAX+2)/2); op++, ip+=2) {
1495
    *op=(uByte)((*ip<<4)+*(ip+1));
1496
    }
1497
  return (bcdar[DECPMAX+1]==DECPMINUS ? DECFLOAT_Sign : 0);
1498
  } /* decFloatToPacked */
1499
 
1500
/* ------------------------------------------------------------------ */
1501
/* decFloatToString -- conversion to numeric string                   */
1502
/*                                                                    */
1503
/*  df is the decFloat format number to convert                       */
1504
/*  string is the string where the result will be laid out            */
1505
/*                                                                    */
1506
/* string must be at least DECPMAX+9 characters (the worst case is    */
1507
/* "-0.00000nnn...nnn\0", which is as long as the exponent form when  */
1508
/* DECEMAXD<=4); this condition is asserted above                     */
1509
/*                                                                    */
1510
/* No error is possible, and no status will be set                    */
1511
/* ------------------------------------------------------------------ */
1512
char * decFloatToString(const decFloat *df, char *string){
1513
  uInt msd;                        /* coefficient MSD */
1514
  Int  exp;                        /* exponent top two bits or full */
1515
  uInt comb;                       /* combination field */
1516
  char *cstart;                    /* coefficient start */
1517
  char *c;                         /* output pointer in string */
1518
  char *s, *t;                     /* .. (source, target) */
1519
  Int  pre, e;                     /* work */
1520
  const uByte *u;                  /* .. */
1521
  uInt  uiwork;                    /* for macros [one compiler needs */
1522
                                   /* volatile here to avoid bug, but */
1523
                                   /* that doubles execution time] */
1524
 
1525
  /* Source words; macro handles endianness */
1526
  uInt sourhi=DFWORD(df, 0);        /* word with sign */
1527
  #if DECPMAX==16
1528
  uInt sourlo=DFWORD(df, 1);
1529
  #elif DECPMAX==34
1530
  uInt sourmh=DFWORD(df, 1);
1531
  uInt sourml=DFWORD(df, 2);
1532
  uInt sourlo=DFWORD(df, 3);
1533
  #endif
1534
 
1535
  c=string;                        /* where result will go */
1536
  if (((Int)sourhi)<0) *c++='-';   /* handle sign */
1537
  comb=sourhi>>26;                 /* sign+combination field */
1538
  msd=DECCOMBMSD[comb];            /* decode the combination field */
1539
  exp=DECCOMBEXP[comb];            /* .. */
1540
 
1541
  if (!EXPISSPECIAL(exp)) {        /* finite */
1542
    /* complete exponent; top two bits are in place */
1543
    exp+=GETECON(df)-DECBIAS;      /* .. + continuation and unbias */
1544
    }
1545
   else {                          /* IS special */
1546
    if (exp==DECFLOAT_Inf) {       /* infinity */
1547
      strcpy(c, "Infinity");
1548
      return string;               /* easy */
1549
      }
1550
    if (sourhi&0x02000000) *c++='s'; /* sNaN */
1551
    strcpy(c, "NaN");              /* complete word */
1552
    c+=3;                          /* step past */
1553
    /* quick exit if the payload is zero */
1554
    #if DECPMAX==7
1555
    if ((sourhi&0x000fffff)==0) return string;
1556
    #elif DECPMAX==16
1557
    if (sourlo==0 && (sourhi&0x0003ffff)==0) return string;
1558
    #elif DECPMAX==34
1559
    if (sourlo==0 && sourml==0 && sourmh==0
1560
     && (sourhi&0x00003fff)==0) return string;
1561
    #endif
1562
    /* otherwise drop through to add integer; set correct exp etc. */
1563
    exp=0; msd=0;            /* setup for following code */
1564
    }
1565
 
1566
  /* convert the digits of the significand to characters */
1567
  cstart=c;                        /* save start of coefficient */
1568
  if (msd) *c++=(char)('0'+(char)msd);  /* non-zero most significant digit */
1569
 
1570
  /* Decode the declets.  After extracting each declet, it is */
1571
  /* decoded to a 4-uByte sequence by table lookup; the four uBytes */
1572
  /* are the three encoded BCD8 digits followed by a 1-byte length */
1573
  /* (significant digits, except that 000 has length 0).  This allows */
1574
  /* us to left-align the first declet with non-zero content, then */
1575
  /* the remaining ones are full 3-char length.  Fixed-length copies */
1576
  /* are used because variable-length memcpy causes a subroutine call */
1577
  /* in at least two compilers.  (The copies are length 4 for speed */
1578
  /* and are safe because the last item in the array is of length */
1579
  /* three and has the length byte following.) */
1580
  #define dpd2char(dpdin) u=&DPD2BCD8[((dpdin)&0x3ff)*4];        \
1581
         if (c!=cstart) {UBFROMUI(c, UBTOUI(u)|CHARMASK); c+=3;} \
1582
          else if (*(u+3)) {                                     \
1583
           UBFROMUI(c, UBTOUI(u+3-*(u+3))|CHARMASK); c+=*(u+3);}
1584
 
1585
  #if DECPMAX==7
1586
  dpd2char(sourhi>>10);                 /* declet 1 */
1587
  dpd2char(sourhi);                     /* declet 2 */
1588
 
1589
  #elif DECPMAX==16
1590
  dpd2char(sourhi>>8);                  /* declet 1 */
1591
  dpd2char((sourhi<<2) | (sourlo>>30)); /* declet 2 */
1592
  dpd2char(sourlo>>20);                 /* declet 3 */
1593
  dpd2char(sourlo>>10);                 /* declet 4 */
1594
  dpd2char(sourlo);                     /* declet 5 */
1595
 
1596
  #elif DECPMAX==34
1597
  dpd2char(sourhi>>4);                  /* declet 1 */
1598
  dpd2char((sourhi<<6) | (sourmh>>26)); /* declet 2 */
1599
  dpd2char(sourmh>>16);                 /* declet 3 */
1600
  dpd2char(sourmh>>6);                  /* declet 4 */
1601
  dpd2char((sourmh<<4) | (sourml>>28)); /* declet 5 */
1602
  dpd2char(sourml>>18);                 /* declet 6 */
1603
  dpd2char(sourml>>8);                  /* declet 7 */
1604
  dpd2char((sourml<<2) | (sourlo>>30)); /* declet 8 */
1605
  dpd2char(sourlo>>20);                 /* declet 9 */
1606
  dpd2char(sourlo>>10);                 /* declet 10 */
1607
  dpd2char(sourlo);                     /* declet 11 */
1608
  #endif
1609
 
1610
  if (c==cstart) *c++='0';         /* all zeros, empty -- make "0" */
1611
 
1612
  /*[This fast path is valid but adds 3-5 cycles to worst case length] */
1613
  /*if (exp==0) {                  // integer or NaN case -- easy */
1614
  /*  *c='\0';                     // terminate */
1615
  /*  return string; */
1616
  /*  } */
1617
 
1618
  e=0;                              /* assume no E */
1619
  pre=(Int)(c-cstart)+exp;         /* length+exp  [c->LSD+1] */
1620
  /* [here, pre-exp is the digits count (==1 for zero)] */
1621
 
1622
  if (exp>0 || pre<-5) {    /* need exponential form */
1623
    e=pre-1;                       /* calculate E value */
1624
    pre=1;                         /* assume one digit before '.' */
1625
    } /* exponential form */
1626
 
1627
  /* modify the coefficient, adding 0s, '.', and E+nn as needed */
1628
  if (pre>0) {                      /* ddd.ddd (plain), perhaps with E */
1629
    char *dotat=cstart+pre;
1630
    if (dotat<c) {                      /* if embedded dot needed... */
1631
      /* [memmove is a disaster, here] */
1632
      /* move by fours; there must be space for junk at the end */
1633
      /* because exponent is still possible */
1634
      s=dotat+ROUNDDOWN4(c-dotat);      /* source */
1635
      t=s+1;                            /* target */
1636
      /* open the gap [cannot use memcpy] */
1637
      for (; s>=dotat; s-=4, t-=4) UBFROMUI(t, UBTOUI(s));
1638
      *dotat='.';
1639
      c++;                              /* length increased by one */
1640
      } /* need dot? */
1641
 
1642
    /* finally add the E-part, if needed; it will never be 0, and has */
1643
    /* a maximum length of 3 or 4 digits (asserted above) */
1644
    if (e!=0) {
1645
      memcpy(c, "E+", 2);               /* starts with E, assume + */
1646
      c++;
1647
      if (e<0) {
1648
        *c='-';                         /* oops, need '-' */
1649
        e=-e;                           /* uInt, please */
1650
        }
1651
      c++;
1652
      /* Three-character exponents are easy; 4-character a little trickier */
1653
      #if DECEMAXD<=3
1654
        u=&BIN2BCD8[e*4];               /* -> 3 digits + length byte */
1655
        /* copy fixed 4 characters [is safe], starting at non-zero */
1656
        /* and with character mask to convert BCD to char */
1657
        UBFROMUI(c, UBTOUI(u+3-*(u+3))|CHARMASK);
1658
        c+=*(u+3);                      /* bump pointer appropriately */
1659
      #elif DECEMAXD==4
1660
        if (e<1000) {                   /* 3 (or fewer) digits case */
1661
          u=&BIN2BCD8[e*4];             /* -> 3 digits + length byte */
1662
          UBFROMUI(c, UBTOUI(u+3-*(u+3))|CHARMASK); /* [as above] */
1663
          c+=*(u+3);                    /* bump pointer appropriately */
1664
          }
1665
         else {                         /* 4-digits */
1666
          Int thou=((e>>3)*1049)>>17;   /* e/1000 */
1667
          Int rem=e-(1000*thou);        /* e%1000 */
1668
          *c++=(char)('0'+(char)thou);  /* the thousands digit */
1669
          u=&BIN2BCD8[rem*4];           /* -> 3 digits + length byte */
1670
          UBFROMUI(c, UBTOUI(u)|CHARMASK); /* copy fixed 3+1 characters [is safe] */
1671
          c+=3;                         /* bump pointer, always 3 digits */
1672
          }
1673
      #endif
1674
      }
1675
    *c='\0';                            /* add terminator */
1676
    /*printf("res %s\n", string); */
1677
    return string;
1678
    } /* pre>0 */
1679
 
1680
  /* -5<=pre<=0: here for plain 0.ddd or 0.000ddd forms (can never have E) */
1681
  /* Surprisingly, this is close to being the worst-case path, so the */
1682
  /* shift is done by fours; this is a little tricky because the */
1683
  /* rightmost character to be written must not be beyond where the */
1684
  /* rightmost terminator could be -- so backoff to not touch */
1685
  /* terminator position if need be (this can make exact alignments */
1686
  /* for full Doubles, but in some cases needs care not to access too */
1687
  /* far to the left) */
1688
 
1689
  pre=-pre+2;                           /* gap width, including "0." */
1690
  t=cstart+ROUNDDOWN4(c-cstart)+pre;    /* preferred first target point */
1691
  /* backoff if too far to the right */
1692
  if (t>string+DECSTRING-5) t=string+DECSTRING-5; /* adjust to fit */
1693
  /* now shift the entire coefficient to the right, being careful not */
1694
  /* to access to the left of string [cannot use memcpy] */
1695
  for (s=t-pre; s>=string; s-=4, t-=4) UBFROMUI(t, UBTOUI(s));
1696
  /* for Quads and Singles there may be a character or two left... */
1697
  s+=3;                                 /* where next would come from */
1698
  for(; s>=cstart; s--, t--) *(t+3)=*(s);
1699
  /* now have fill 0. through 0.00000; use overlaps to avoid tests */
1700
  if (pre>=4) {
1701
    memcpy(cstart+pre-4, "0000", 4);
1702
    memcpy(cstart, "0.00", 4);
1703
    }
1704
   else { /* 2 or 3 */
1705
    *(cstart+pre-1)='0';
1706
    memcpy(cstart, "0.", 2);
1707
    }
1708
  *(c+pre)='\0';                        /* terminate */
1709
  return string;
1710
  } /* decFloatToString */
1711
 
1712
/* ------------------------------------------------------------------ */
1713
/* decFloatToWider -- conversion to next-wider format                 */
1714
/*                                                                    */
1715
/*  source  is the decFloat format number which gets the result of    */
1716
/*          the conversion                                            */
1717
/*  wider   is the decFloatWider format number which will be narrowed */
1718
/*  returns wider                                                     */
1719
/*                                                                    */
1720
/* Widening is always exact; no status is set (sNaNs are copied and   */
1721
/* do not signal).  The result will be canonical if the source is,    */
1722
/* and may or may not be if the source is not.                        */
1723
/* ------------------------------------------------------------------ */
1724
/* widening is not possible for decQuad format numbers; simply omit */
1725
#if !QUAD
1726
decFloatWider * decFloatToWider(const decFloat *source, decFloatWider *wider) {
1727
  uInt msd;
1728
 
1729
  /* Construct and copy the sign word */
1730
  if (DFISSPECIAL(source)) {
1731
    /* copy sign, combination, and first bit of exponent (sNaN selector) */
1732
    DFWWORD(wider, 0)=DFWORD(source, 0)&0xfe000000;
1733
    msd=0;
1734
    }
1735
   else { /* is finite number */
1736
    uInt exp=GETEXPUN(source)+DECWBIAS; /* get unbiased exponent and rebias */
1737
    uInt code=(exp>>DECWECONL)<<29;     /* set two bits of exp [msd=0] */
1738
    code|=(exp<<(32-6-DECWECONL)) & 0x03ffffff; /* add exponent continuation */
1739
    code|=DFWORD(source, 0)&0x80000000; /* add sign */
1740
    DFWWORD(wider, 0)=code;              /* .. and place top word in wider */
1741
    msd=GETMSD(source);                 /* get source coefficient MSD [0-9] */
1742
    }
1743
  /* Copy the coefficient and clear any 'unused' words to left */
1744
  #if SINGLE
1745
    DFWWORD(wider, 1)=(DFWORD(source, 0)&0x000fffff)|(msd<<20);
1746
  #elif DOUBLE
1747
    DFWWORD(wider, 2)=(DFWORD(source, 0)&0x0003ffff)|(msd<<18);
1748
    DFWWORD(wider, 3)=DFWORD(source, 1);
1749
    DFWWORD(wider, 1)=0;
1750
  #endif
1751
  return wider;
1752
  } /* decFloatToWider */
1753
#endif
1754
 
1755
/* ------------------------------------------------------------------ */
1756
/* decFloatVersion -- return package version string                   */
1757
/*                                                                    */
1758
/*  returns a constant string describing this package                 */
1759
/* ------------------------------------------------------------------ */
1760
const char *decFloatVersion(void) {
1761
  return DECVERSION;
1762
  } /* decFloatVersion */
1763
 
1764
/* ------------------------------------------------------------------ */
1765
/* decFloatZero -- set to canonical (integer) zero                    */
1766
/*                                                                    */
1767
/*  df is the decFloat format number to integer +0 (q=0, c=+0)        */
1768
/*  returns df                                                        */
1769
/*                                                                    */
1770
/* No error is possible, and no status can be set.                    */
1771
/* ------------------------------------------------------------------ */
1772
decFloat * decFloatZero(decFloat *df){
1773
  DFWORD(df, 0)=ZEROWORD;     /* set appropriate top word */
1774
  #if DOUBLE || QUAD
1775
    DFWORD(df, 1)=0;
1776
    #if QUAD
1777
      DFWORD(df, 2)=0;
1778
      DFWORD(df, 3)=0;
1779
    #endif
1780
  #endif
1781
  /* decFloatShow(df, "zero"); */
1782
  return df;
1783
  } /* decFloatZero */
1784
 
1785
/* ------------------------------------------------------------------ */
1786
/* Private generic function (not format-specific) for development use */
1787
/* ------------------------------------------------------------------ */
1788
/* This is included once only, for all to use */
1789
#if QUAD && (DECCHECK || DECTRACE)
1790
  /* ---------------------------------------------------------------- */
1791
  /* decShowNum -- display bcd8 number in debug form                  */
1792
  /*                                                                  */
1793
  /*   num is the bcdnum to display                                   */
1794
  /*   tag is a string to label the display                           */
1795
  /* ---------------------------------------------------------------- */
1796
  void decShowNum(const bcdnum *num, const char *tag) {
1797
    const char *csign="+";              /* sign character */
1798
    uByte *ub;                          /* work */
1799
    uInt  uiwork;                       /* for macros */
1800
    if (num->sign==DECFLOAT_Sign) csign="-";
1801
 
1802
    printf(">%s> ", tag);
1803
    if (num->exponent==DECFLOAT_Inf) printf("%sInfinity", csign);
1804
    else if (num->exponent==DECFLOAT_qNaN) printf("%sqNaN", csign);
1805
    else if (num->exponent==DECFLOAT_sNaN) printf("%ssNaN", csign);
1806
    else {                              /* finite */
1807
     char qbuf[10];                     /* for right-aligned q */
1808
     char *c;                           /* work */
1809
     const uByte *u;                    /* .. */
1810
     Int e=num->exponent;               /* .. exponent */
1811
     strcpy(qbuf, "q=");
1812
     c=&qbuf[2];                        /* where exponent will go */
1813
     /* lay out the exponent */
1814
     if (e<0) {
1815
       *c++='-';                        /* add '-' */
1816
       e=-e;                            /* uInt, please */
1817
       }
1818
     #if DECEMAXD>4
1819
       #error Exponent form is too long for ShowNum to lay out
1820
     #endif
1821
     if (e==0) *c++='0';         /* 0-length case */
1822
      else if (e<1000) {                /* 3 (or fewer) digits case */
1823
       u=&BIN2BCD8[e*4];                /* -> 3 digits + length byte */
1824
       UBFROMUI(c, UBTOUI(u+3-*(u+3))|CHARMASK); /* [as above] */
1825
       c+=*(u+3);                       /* bump pointer appropriately */
1826
       }
1827
      else {                            /* 4-digits */
1828
       Int thou=((e>>3)*1049)>>17;      /* e/1000 */
1829
       Int rem=e-(1000*thou);           /* e%1000 */
1830
       *c++=(char)('0'+(char)thou);     /* the thousands digit */
1831
       u=&BIN2BCD8[rem*4];              /* -> 3 digits + length byte */
1832
       UBFROMUI(c, UBTOUI(u)|CHARMASK); /* copy fixed 3+1 characters [is safe] */
1833
       c+=3;                            /* bump pointer, always 3 digits */
1834
       }
1835
     *c='\0';                           /* add terminator */
1836
     printf("%7s c=%s", qbuf, csign);
1837
     }
1838
 
1839
    if (!EXPISSPECIAL(num->exponent) || num->msd!=num->lsd || *num->lsd!=0) {
1840
      for (ub=num->msd; ub<=num->lsd; ub++) { /* coefficient... */
1841
        printf("%1x", *ub);
1842
        if ((num->lsd-ub)%3==0 && ub!=num->lsd) printf(" "); /* 4-space */
1843
        }
1844
      }
1845
    printf("\n");
1846
    } /* decShowNum */
1847
#endif

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