1 /****************************************************************
2 *
3 * The author of this software is David M. Gay.
4 *
5 * Copyright (c) 1991 by AT&T.
6 *
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose without fee is hereby granted, provided that this entire notice
9 * is included in all copies of any software which is or includes a copy
10 * or modification of this software and in all copies of the supporting
11 * documentation for such software.
12 *
13 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
14 * WARRANTY. IN PARTICULAR, NEITHER THE AUTHOR NOR AT&T MAKES ANY
15 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
16 * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
17 *
18 ***************************************************************/
19
20 /* Please send bug reports to
21 David M. Gay
22 AT&T Bell Laboratories, Room 2C-463
23 600 Mountain Avenue
24 Murray Hill, NJ 07974-2070
25 U.S.A.
26 dmg@research.att.com or research!dmg
27 */
28
29 #define _DEFAULT_SOURCE
30 #include <_ansi.h>
31 #include <stdlib.h>
32 #include <string.h>
33 #include "mprec.h"
34
35 static int
quorem(_Bigint * b,_Bigint * S)36 quorem (_Bigint * b, _Bigint * S)
37 {
38 int n;
39 __Long borrow, y;
40 __ULong carry, q, ys;
41 __ULong *bx, *bxe, *sx, *sxe;
42 #ifdef Pack_32
43 __Long z;
44 __ULong si, zs;
45 #endif
46
47 if (!b || !S)
48 return 0;
49
50 n = S->_wds;
51 #ifdef DEBUG
52 /*debug*/ if (b->_wds > n)
53 /*debug*/ Bug ("oversize b in quorem");
54 #endif
55 if (b->_wds < n)
56 return 0;
57 sx = S->_x;
58 sxe = sx + --n;
59 bx = b->_x;
60 bxe = bx + n;
61 q = *bxe / (*sxe + 1); /* ensure q <= true quotient */
62 #ifdef DEBUG
63 /*debug*/ if (q > 9)
64 /*debug*/ Bug ("oversized quotient in quorem");
65 #endif
66 if (q)
67 {
68 borrow = 0;
69 carry = 0;
70 do
71 {
72 #ifdef Pack_32
73 si = *sx++;
74 ys = (si & 0xffff) * q + carry;
75 zs = (si >> 16) * q + (ys >> 16);
76 carry = zs >> 16;
77 y = (*bx & 0xffff) - (ys & 0xffff) + borrow;
78 borrow = y >> 16;
79 Sign_Extend (borrow, y);
80 z = (*bx >> 16) - (zs & 0xffff) + borrow;
81 borrow = z >> 16;
82 Sign_Extend (borrow, z);
83 Storeinc (bx, z, y);
84 #else
85 ys = *sx++ * q + carry;
86 carry = ys >> 16;
87 y = *bx - (ys & 0xffff) + borrow;
88 borrow = y >> 16;
89 Sign_Extend (borrow, y);
90 *bx++ = y & 0xffff;
91 #endif
92 }
93 while (sx <= sxe);
94 if (!*bxe)
95 {
96 bx = b->_x;
97 while (--bxe > bx && !*bxe)
98 --n;
99 b->_wds = n;
100 }
101 }
102 if (cmp (b, S) >= 0)
103 {
104 q++;
105 borrow = 0;
106 carry = 0;
107 bx = b->_x;
108 sx = S->_x;
109 do
110 {
111 #ifdef Pack_32
112 si = *sx++;
113 ys = (si & 0xffff) + carry;
114 zs = (si >> 16) + (ys >> 16);
115 carry = zs >> 16;
116 y = (*bx & 0xffff) - (ys & 0xffff) + borrow;
117 borrow = y >> 16;
118 Sign_Extend (borrow, y);
119 z = (*bx >> 16) - (zs & 0xffff) + borrow;
120 borrow = z >> 16;
121 Sign_Extend (borrow, z);
122 Storeinc (bx, z, y);
123 #else
124 ys = *sx++ + carry;
125 carry = ys >> 16;
126 y = *bx - (ys & 0xffff) + borrow;
127 borrow = y >> 16;
128 Sign_Extend (borrow, y);
129 *bx++ = y & 0xffff;
130 #endif
131 }
132 while (sx <= sxe);
133 bx = b->_x;
134 bxe = bx + n;
135 if (!*bxe)
136 {
137 while (--bxe > bx && !*bxe)
138 --n;
139 b->_wds = n;
140 }
141 }
142 return q;
143 }
144
145 /* dtoa for IEEE arithmetic (dmg): convert double to ASCII string.
146 *
147 * Inspired by "How to Print Floating-Point Numbers Accurately" by
148 * Guy L. Steele, Jr. and Jon L. White [Proc. ACM SIGPLAN '90, pp. 92-101].
149 *
150 * Modifications:
151 * 1. Rather than iterating, we use a simple numeric overestimate
152 * to determine k = floor(log10(d)). We scale relevant
153 * quantities using O(log2(k)) rather than O(k) multiplications.
154 * 2. For some modes > 2 (corresponding to ecvt and fcvt), we don't
155 * try to generate digits strictly left to right. Instead, we
156 * compute with fewer bits and propagate the carry if necessary
157 * when rounding the final digit up. This is often faster.
158 * 3. Under the assumption that input will be rounded nearest,
159 * mode 0 renders 1e23 as 1e23 rather than 9.999999999999999e22.
160 * That is, we allow equality in stopping tests when the
161 * round-nearest rule will give the same floating-point value
162 * as would satisfaction of the stopping test with strict
163 * inequality.
164 * 4. We remove common factors of powers of 2 from relevant
165 * quantities.
166 * 5. When converting floating-point integers less than 1e16,
167 * we use floating-point arithmetic rather than resorting
168 * to multiple-precision integers.
169 * 6. When asked to produce fewer than 15 digits, we first try
170 * to get by with floating-point arithmetic; we resort to
171 * multiple-precision integer arithmetic only if we cannot
172 * guarantee that the floating-point calculation has given
173 * the correctly rounded result. For k requested digits and
174 * "uniformly" distributed input, the probability is
175 * something like 10^(k-15) that we must resort to the long
176 * calculation.
177 */
178
179
180 char *
__dtoa(double _d,int mode,int ndigits,int * decpt,int * sign,char ** rve)181 __dtoa (
182 double _d,
183 int mode,
184 int ndigits,
185 int *decpt,
186 int *sign,
187 char **rve)
188 {
189 /* Arguments ndigits, decpt, sign are similar to those
190 of ecvt and fcvt; trailing zeros are suppressed from
191 the returned string. If not null, *rve is set to point
192 to the end of the return value. If d is +-Infinity or NaN,
193 then *decpt is set to 9999.
194
195 mode:
196 0 ==> shortest string that yields d when read in
197 and rounded to nearest.
198 1 ==> like 0, but with Steele & White stopping rule;
199 e.g. with IEEE P754 arithmetic , mode 0 gives
200 1e23 whereas mode 1 gives 9.999999999999999e22.
201 2 ==> max(1,ndigits) significant digits. This gives a
202 return value similar to that of ecvt, except
203 that trailing zeros are suppressed.
204 3 ==> through ndigits past the decimal point. This
205 gives a return value similar to that from fcvt,
206 except that trailing zeros are suppressed, and
207 ndigits can be negative.
208 4-9 should give the same return values as 2-3, i.e.,
209 4 <= mode <= 9 ==> same return as mode
210 2 + (mode & 1). These modes are mainly for
211 debugging; often they run slower but sometimes
212 faster than modes 2-3.
213 4,5,8,9 ==> left-to-right digit generation.
214 6-9 ==> don't try fast floating-point estimate
215 (if applicable).
216
217 Values of mode other than 0-9 are treated as mode 0.
218
219 Sufficient space is allocated to the return value
220 to hold the suppressed trailing zeros.
221 */
222
223 int bbits, b2, b5, be, dig, i, ieps, ilim, ilim0, ilim1, j, j1, k, k0,
224 k_check, leftright, m2, m5, s2, s5, spec_case, try_quick;
225 union double_union d, d2, eps;
226 __Long L;
227 #ifndef Sudden_Underflow
228 int denorm;
229 __ULong x;
230 #endif
231 _Bigint *b, *b1, *delta, *mlo = NULL, *mhi, *S;
232 double ds;
233 char *s, *s0;
234
235 d.d = _d;
236
237 if (word0 (d) & Sign_bit)
238 {
239 /* set sign for everything, including 0's and NaNs */
240 *sign = 1;
241 word0 (d) &= ~Sign_bit; /* clear sign bit */
242 }
243 else
244 *sign = 0;
245
246 #if defined(IEEE_Arith) + defined(VAX)
247 #ifdef IEEE_Arith
248 if ((word0 (d) & Exp_mask) == Exp_mask)
249 #else
250 if (word0 (d) == 0x8000)
251 #endif
252 {
253 /* Infinity or NaN */
254 *decpt = 9999;
255 s =
256 #ifdef IEEE_Arith
257 !word1 (d) && !(word0 (d) & 0xfffff) ? "Infinity" :
258 #endif
259 "NaN";
260 if (rve)
261 *rve =
262 #ifdef IEEE_Arith
263 s[3] ? s + 8 :
264 #endif
265 s + 3;
266 return s;
267 }
268 #endif
269 #ifdef IBM
270 d.d += 0; /* normalize */
271 #endif
272 if (!d.d)
273 {
274 *decpt = 1;
275 s = "0";
276 if (rve)
277 *rve = s + 1;
278 return s;
279 }
280
281 b = d2b (d.d, &be, &bbits);
282 if (!b)
283 return NULL;
284 #ifdef Sudden_Underflow
285 i = (int) (word0 (d) >> Exp_shift1 & (Exp_mask >> Exp_shift1));
286 #else
287 if ((i = (int) (word0 (d) >> Exp_shift1 & (Exp_mask >> Exp_shift1))) != 0)
288 {
289 #endif
290 d2.d = d.d;
291 word0 (d2) &= Frac_mask1;
292 word0 (d2) |= Exp_11;
293 #ifdef IBM
294 if (j = 11 - hi0bits (word0 (d2) & Frac_mask))
295 d2.d /= 1 << j;
296 #endif
297
298 /* log(x) ~=~ log(1.5) + (x-1.5)/1.5
299 * log10(x) = log(x) / log(10)
300 * ~=~ log(1.5)/log(10) + (x-1.5)/(1.5*log(10))
301 * log10(d) = (i-Bias)*log(2)/log(10) + log10(d2)
302 *
303 * This suggests computing an approximation k to log10(d) by
304 *
305 * k = (i - Bias)*0.301029995663981
306 * + ( (d2-1.5)*0.289529654602168 + 0.176091259055681 );
307 *
308 * We want k to be too large rather than too small.
309 * The error in the first-order Taylor series approximation
310 * is in our favor, so we just round up the constant enough
311 * to compensate for any error in the multiplication of
312 * (i - Bias) by 0.301029995663981; since |i - Bias| <= 1077,
313 * and 1077 * 0.30103 * 2^-52 ~=~ 7.2e-14,
314 * adding 1e-13 to the constant term more than suffices.
315 * Hence we adjust the constant term to 0.1760912590558.
316 * (We could get a more accurate k by invoking log10,
317 * but this is probably not worthwhile.)
318 */
319
320 i -= Bias;
321 #ifdef IBM
322 i <<= 2;
323 i += j;
324 #endif
325 #ifndef Sudden_Underflow
326 denorm = 0;
327 }
328 else
329 {
330 /* d is denormalized */
331
332 i = bbits + be + (Bias + (P - 1) - 1);
333 #if defined (_DOUBLE_IS_32BITS)
334 x = word0 (d) << (32 - i);
335 #else
336 x = (i > 32) ? (word0 (d) << (64 - i)) | (word1 (d) >> (i - 32))
337 : (word1 (d) << (32 - i));
338 #endif
339 d2.d = x;
340 word0 (d2) -= 31 * Exp_msk1; /* adjust exponent */
341 i -= (Bias + (P - 1) - 1) + 1;
342 denorm = 1;
343 }
344 #endif
345 #if defined (_DOUBLE_IS_32BITS)
346 ds = (d2.d - 1.5) * 0.289529651 + 0.176091269 + i * 0.30103001;
347 #else
348 ds = (d2.d - 1.5) * 0.289529654602168 + 0.1760912590558 + i * 0.301029995663981;
349 #endif
350 k = (int) ds;
351 if (ds < 0. && ds != k)
352 k--; /* want k = floor(ds) */
353 k_check = 1;
354 if (k >= 0 && k <= Ten_pmax)
355 {
356 if (d.d < tens[k])
357 k--;
358 k_check = 0;
359 }
360 j = bbits - i - 1;
361 if (j >= 0)
362 {
363 b2 = 0;
364 s2 = j;
365 }
366 else
367 {
368 b2 = -j;
369 s2 = 0;
370 }
371 if (k >= 0)
372 {
373 b5 = 0;
374 s5 = k;
375 s2 += k;
376 }
377 else
378 {
379 b2 -= k;
380 b5 = -k;
381 s5 = 0;
382 }
383 if (mode < 0 || mode > 9)
384 mode = 0;
385 try_quick = 1;
386 if (mode > 5)
387 {
388 mode -= 4;
389 try_quick = 0;
390 }
391 leftright = 1;
392 ilim = ilim1 = -1;
393 switch (mode)
394 {
395 case 0:
396 case 1:
397 i = 18;
398 ndigits = 0;
399 break;
400 case 2:
401 leftright = 0;
402 FALLTHROUGH;
403 case 4:
404 if (ndigits <= 0)
405 ndigits = 1;
406 ilim = ilim1 = i = ndigits;
407 break;
408 case 3:
409 leftright = 0;
410 FALLTHROUGH;
411 case 5:
412 i = ndigits + k + 1;
413 ilim = i;
414 ilim1 = i - 1;
415 if (i <= 0)
416 i = 1;
417 }
418 s = s0 = __alloc_dtoa_result(i);
419 if (!s) {
420 Bfree(b);
421 return NULL;
422 }
423
424 if (ilim >= 0 && ilim <= Quick_max && try_quick)
425 {
426 /* Try to get by with floating-point arithmetic. */
427
428 i = 0;
429 d2.d = d.d;
430 k0 = k;
431 ilim0 = ilim;
432 ieps = 2; /* conservative */
433 if (k > 0)
434 {
435 ds = tens[k & 0xf];
436 j = k >> 4;
437 if (j & Bletch)
438 {
439 /* prevent overflows */
440 j &= Bletch - 1;
441 d.d /= bigtens[n_bigtens - 1];
442 ieps++;
443 }
444 for (; j; j >>= 1, i++)
445 if (j & 1)
446 {
447 ieps++;
448 ds *= bigtens[i];
449 }
450 d.d /= ds;
451 }
452 else if ((j1 = -k) != 0)
453 {
454 d.d *= tens[j1 & 0xf];
455 for (j = j1 >> 4; j; j >>= 1, i++)
456 if (j & 1)
457 {
458 ieps++;
459 d.d *= bigtens[i];
460 }
461 }
462 if (k_check && d.d < 1. && ilim > 0)
463 {
464 if (ilim1 <= 0)
465 goto fast_failed;
466 ilim = ilim1;
467 k--;
468 d.d *= 10.;
469 ieps++;
470 }
471 eps.d = ieps * d.d + 7.;
472 word0 (eps) -= (P - 1) * Exp_msk1;
473 if (ilim == 0)
474 {
475 S = mhi = 0;
476 d.d -= 5.;
477 if (d.d > eps.d)
478 goto one_digit;
479 if (d.d < -eps.d)
480 goto no_digits;
481 goto fast_failed;
482 }
483 #ifndef No_leftright
484 if (leftright)
485 {
486 /* Use Steele & White method of only
487 * generating digits needed.
488 */
489 eps.d = 0.5 / tens[ilim - 1] - eps.d;
490 for (i = 0;;)
491 {
492 L = d.d;
493 d.d -= L;
494 *s++ = '0' + (int) L;
495 if (d.d < eps.d)
496 goto ret1;
497 if (1. - d.d < eps.d)
498 goto bump_up;
499 if (++i >= ilim)
500 break;
501 eps.d *= 10.;
502 d.d *= 10.;
503 }
504 }
505 else
506 {
507 #endif
508 /* Generate ilim digits, then fix them up. */
509 eps.d *= tens[ilim - 1];
510 for (i = 1;; i++, d.d *= 10.)
511 {
512 L = d.d;
513 d.d -= L;
514 *s++ = '0' + (int) L;
515 if (i == ilim)
516 {
517 if (d.d > 0.5 + eps.d)
518 goto bump_up;
519 else if (d.d < 0.5 - eps.d)
520 {
521 while (*--s == '0');
522 s++;
523 goto ret1;
524 }
525 break;
526 }
527 }
528 #ifndef No_leftright
529 }
530 #endif
531 fast_failed:
532 s = s0;
533 d.d = d2.d;
534 k = k0;
535 ilim = ilim0;
536 }
537
538 /* Do we have a "small" integer? */
539
540 if (be >= 0 && k <= Int_max)
541 {
542 /* Yes. */
543 ds = tens[k];
544 if (ndigits < 0 && ilim <= 0)
545 {
546 S = mhi = 0;
547 if (ilim < 0 || d.d <= 5 * ds)
548 goto no_digits;
549 goto one_digit;
550 }
551 for (i = 1;; i++)
552 {
553 L = d.d / ds;
554 d.d -= L * ds;
555 #ifdef Check_FLT_ROUNDS
556 /* If FLT_ROUNDS == 2, L will usually be high by 1 */
557 if (d.d < 0)
558 {
559 L--;
560 d.d += ds;
561 }
562 #endif
563 *s++ = '0' + (int) L;
564 if (i == ilim)
565 {
566 d.d += d.d;
567 if ((d.d > ds) || ((d.d == ds) && (L & 1)))
568 {
569 bump_up:
570 while (*--s == '9')
571 if (s == s0)
572 {
573 k++;
574 *s = '0';
575 break;
576 }
577 ++*s++;
578 }
579 break;
580 }
581 if (!(d.d *= 10.))
582 break;
583 }
584 goto ret1;
585 }
586
587 m2 = b2;
588 m5 = b5;
589 mhi = mlo = 0;
590 if (leftright)
591 {
592 if (mode < 2)
593 {
594 i =
595 #ifndef Sudden_Underflow
596 denorm ? be + (Bias + (P - 1) - 1 + 1) :
597 #endif
598 #ifdef IBM
599 1 + 4 * P - 3 - bbits + ((bbits + be - 1) & 3);
600 #else
601 1 + P - bbits;
602 #endif
603 }
604 else
605 {
606 j = ilim - 1;
607 if (m5 >= j)
608 m5 -= j;
609 else
610 {
611 s5 += j -= m5;
612 b5 += j;
613 m5 = 0;
614 }
615 if ((i = ilim) < 0)
616 {
617 m2 -= i;
618 i = 0;
619 }
620 }
621 b2 += i;
622 s2 += i;
623 mhi = i2b (1);
624 }
625 if (m2 > 0 && s2 > 0)
626 {
627 i = m2 < s2 ? m2 : s2;
628 b2 -= i;
629 m2 -= i;
630 s2 -= i;
631 }
632 if (b5 > 0)
633 {
634 if (leftright)
635 {
636 if (m5 > 0)
637 {
638 mhi = pow5mult (mhi, m5);
639 b1 = mult (mhi, b);
640 Bfree (b);
641 b = b1;
642 }
643 if ((j = b5 - m5) != 0)
644 b = pow5mult (b, j);
645 }
646 else
647 b = pow5mult (b, b5);
648 }
649 S = i2b (1);
650 if (s5 > 0)
651 S = pow5mult (S, s5);
652 if (!S)
653 goto ret;
654
655 /* Check for special case that d is a normalized power of 2. */
656
657 spec_case = 0;
658 if (mode < 2)
659 {
660 if (!word1 (d) && !(word0 (d) & Bndry_mask)
661 #ifndef Sudden_Underflow
662 && word0 (d) & Exp_mask
663 #endif
664 )
665 {
666 /* The special case */
667 b2 += Log2P;
668 s2 += Log2P;
669 spec_case = 1;
670 }
671 }
672
673 /* Arrange for convenient computation of quotients:
674 * shift left if necessary so divisor has 4 leading 0 bits.
675 *
676 * Perhaps we should just compute leading 28 bits of S once
677 * and for all and pass them and a shift to quorem, so it
678 * can do shifts and ors to compute the numerator for q.
679 */
680
681 #ifdef Pack_32
682 if ((i = ((s5 ? 32 - hi0bits (S->_x[S->_wds - 1]) : 1) + s2) & 0x1f) != 0)
683 i = 32 - i;
684 #else
685 if ((i = ((s5 ? 32 - hi0bits (S->_x[S->_wds - 1]) : 1) + s2) & 0xf) != 0)
686 i = 16 - i;
687 #endif
688 if (i > 4)
689 {
690 i -= 4;
691 b2 += i;
692 m2 += i;
693 s2 += i;
694 }
695 else if (i < 4)
696 {
697 i += 28;
698 b2 += i;
699 m2 += i;
700 s2 += i;
701 }
702 if (b2 > 0)
703 b = lshift (b, b2);
704 if (s2 > 0)
705 S = lshift (S, s2);
706 if (k_check)
707 {
708 if (cmp (b, S) < 0)
709 {
710 k--;
711 b = multadd (b, 10, 0); /* we botched the k estimate */
712 if (leftright)
713 mhi = multadd (mhi, 10, 0);
714 ilim = ilim1;
715 }
716 }
717 if (ilim <= 0 && mode > 2)
718 {
719 if (ilim < 0 || cmp (b, S = multadd (S, 5, 0)) <= 0)
720 {
721 /* no digits, fcvt style */
722 no_digits:
723 k = -1 - ndigits;
724 goto ret;
725 }
726 one_digit:
727 *s++ = '1';
728 k++;
729 goto ret;
730 }
731 if (leftright)
732 {
733 if (m2 > 0)
734 mhi = lshift (mhi, m2);
735
736 /* Compute mlo -- check for special case
737 * that d is a normalized power of 2.
738 */
739
740 mlo = mhi;
741 if (spec_case)
742 {
743 mhi = Balloc (mhi->_k);
744 if (!mhi) {
745 Bfree(mlo);
746 return NULL;
747 }
748 Bcopy (mhi, mlo);
749 mhi = lshift (mhi, Log2P);
750 }
751
752 for (i = 1;; i++)
753 {
754 dig = quorem (b, S) + '0';
755 /* Do we yet have the shortest decimal string
756 * that will round to d?
757 */
758 j = cmp (b, mlo);
759 delta = diff (S, mhi);
760 j1 = delta->_sign ? 1 : cmp (b, delta);
761 Bfree (delta);
762 #ifndef ROUND_BIASED
763 if (j1 == 0 && !mode && !(word1 (d) & 1))
764 {
765 if (dig == '9')
766 goto round_9_up;
767 if (j > 0)
768 dig++;
769 *s++ = dig;
770 goto ret;
771 }
772 #endif
773 if ((j < 0) || ((j == 0) && !mode
774 #ifndef ROUND_BIASED
775 && !(word1 (d) & 1)
776 #endif
777 ))
778 {
779 if (j1 > 0)
780 {
781 b = lshift (b, 1);
782 j1 = cmp (b, S);
783 if (((j1 > 0) || ((j1 == 0) && (dig & 1)))
784 && dig++ == '9')
785 goto round_9_up;
786 }
787 *s++ = dig;
788 goto ret;
789 }
790 if (j1 > 0)
791 {
792 if (dig == '9')
793 { /* possible if i == 1 */
794 round_9_up:
795 *s++ = '9';
796 goto roundoff;
797 }
798 *s++ = dig + 1;
799 goto ret;
800 }
801 *s++ = dig;
802 if (i == ilim)
803 break;
804 b = multadd (b, 10, 0);
805 if (mlo == mhi)
806 mlo = mhi = multadd (mhi, 10, 0);
807 else
808 {
809 mlo = multadd (mlo, 10, 0);
810 mhi = multadd (mhi, 10, 0);
811 }
812 }
813 }
814 else
815 for (i = 1;; i++)
816 {
817 *s++ = dig = quorem (b, S) + '0';
818 if (i >= ilim)
819 break;
820 b = multadd (b, 10, 0);
821 }
822
823 /* Round off last digit */
824
825 b = lshift (b, 1);
826 j = cmp (b, S);
827 if ((j > 0) || ((j == 0) && (dig & 1)))
828 {
829 roundoff:
830 while (*--s == '9')
831 if (s == s0)
832 {
833 k++;
834 *s++ = '1';
835 goto ret;
836 }
837 ++*s++;
838 }
839 else
840 {
841 while (*--s == '0');
842 s++;
843 }
844 ret:
845 Bfree (S);
846 if (mhi)
847 {
848 if (mlo && mlo != mhi)
849 Bfree (mlo);
850 Bfree (mhi);
851 }
852 ret1:
853 Bfree (b);
854 *s = 0;
855 *decpt = k + 1;
856 if (rve)
857 *rve = s;
858 return s0;
859 }
860
