diff options
Diffstat (limited to 'StdLib/LibC/gdtoa/dtoa.c')
| -rw-r--r-- | StdLib/LibC/gdtoa/dtoa.c | 821 |
1 files changed, 821 insertions, 0 deletions
diff --git a/StdLib/LibC/gdtoa/dtoa.c b/StdLib/LibC/gdtoa/dtoa.c new file mode 100644 index 0000000000..42098426fd --- /dev/null +++ b/StdLib/LibC/gdtoa/dtoa.c @@ -0,0 +1,821 @@ +/* $NetBSD: dtoa.c,v 1.3.4.1.4.1 2008/04/08 21:10:55 jdc Exp $ */
+
+/****************************************************************
+
+The author of this software is David M. Gay.
+
+Copyright (C) 1998, 1999 by Lucent Technologies
+All Rights Reserved
+
+Permission to use, copy, modify, and distribute this software and
+its documentation for any purpose and without fee is hereby
+granted, provided that the above copyright notice appear in all
+copies and that both that the copyright notice and this
+permission notice and warranty disclaimer appear in supporting
+documentation, and that the name of Lucent or any of its entities
+not be used in advertising or publicity pertaining to
+distribution of the software without specific, written prior
+permission.
+
+LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
+IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
+SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
+IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
+ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
+THIS SOFTWARE.
+
+****************************************************************/
+
+/* Please send bug reports to David M. Gay (dmg at acm dot org,
+ * with " at " changed at "@" and " dot " changed to "."). */
+#include <LibConfig.h>
+
+#include "gdtoaimp.h"
+
+/* dtoa for IEEE arithmetic (dmg): convert double to ASCII string.
+ *
+ * Inspired by "How to Print Floating-Point Numbers Accurately" by
+ * Guy L. Steele, Jr. and Jon L. White [Proc. ACM SIGPLAN '90, pp. 112-126].
+ *
+ * Modifications:
+ * 1. Rather than iterating, we use a simple numeric overestimate
+ * to determine k = floor(log10(d)). We scale relevant
+ * quantities using O(log2(k)) rather than O(k) multiplications.
+ * 2. For some modes > 2 (corresponding to ecvt and fcvt), we don't
+ * try to generate digits strictly left to right. Instead, we
+ * compute with fewer bits and propagate the carry if necessary
+ * when rounding the final digit up. This is often faster.
+ * 3. Under the assumption that input will be rounded nearest,
+ * mode 0 renders 1e23 as 1e23 rather than 9.999999999999999e22.
+ * That is, we allow equality in stopping tests when the
+ * round-nearest rule will give the same floating-point value
+ * as would satisfaction of the stopping test with strict
+ * inequality.
+ * 4. We remove common factors of powers of 2 from relevant
+ * quantities.
+ * 5. When converting floating-point integers less than 1e16,
+ * we use floating-point arithmetic rather than resorting
+ * to multiple-precision integers.
+ * 6. When asked to produce fewer than 15 digits, we first try
+ * to get by with floating-point arithmetic; we resort to
+ * multiple-precision integer arithmetic only if we cannot
+ * guarantee that the floating-point calculation has given
+ * the correctly rounded result. For k requested digits and
+ * "uniformly" distributed input, the probability is
+ * something like 10^(k-15) that we must resort to the Long
+ * calculation.
+ */
+
+#ifdef Honor_FLT_ROUNDS
+#define Rounding rounding
+#undef Check_FLT_ROUNDS
+#define Check_FLT_ROUNDS
+#else
+#define Rounding Flt_Rounds
+#endif
+
+#if defined(_MSC_VER) /* Handle Microsoft VC++ compiler specifics. */
+// Disable: warning C4700: uninitialized local variable 'xx' used
+#pragma warning ( disable : 4700 )
+#endif /* defined(_MSC_VER) */
+
+ char *
+dtoa
+#ifdef KR_headers
+ (d, mode, ndigits, decpt, sign, rve)
+ double d; int mode, ndigits, *decpt, *sign; char **rve;
+#else
+ (double d, int mode, int ndigits, int *decpt, int *sign, char **rve)
+#endif
+{
+ /* Arguments ndigits, decpt, sign are similar to those
+ of ecvt and fcvt; trailing zeros are suppressed from
+ the returned string. If not null, *rve is set to point
+ to the end of the return value. If d is +-Infinity or NaN,
+ then *decpt is set to 9999.
+
+ mode:
+ 0 ==> shortest string that yields d when read in
+ and rounded to nearest.
+ 1 ==> like 0, but with Steele & White stopping rule;
+ e.g. with IEEE P754 arithmetic , mode 0 gives
+ 1e23 whereas mode 1 gives 9.999999999999999e22.
+ 2 ==> max(1,ndigits) significant digits. This gives a
+ return value similar to that of ecvt, except
+ that trailing zeros are suppressed.
+ 3 ==> through ndigits past the decimal point. This
+ gives a return value similar to that from fcvt,
+ except that trailing zeros are suppressed, and
+ ndigits can be negative.
+ 4,5 ==> similar to 2 and 3, respectively, but (in
+ round-nearest mode) with the tests of mode 0 to
+ possibly return a shorter string that rounds to d.
+ With IEEE arithmetic and compilation with
+ -DHonor_FLT_ROUNDS, modes 4 and 5 behave the same
+ as modes 2 and 3 when FLT_ROUNDS != 1.
+ 6-9 ==> Debugging modes similar to mode - 4: don't try
+ fast floating-point estimate (if applicable).
+
+ Values of mode other than 0-9 are treated as mode 0.
+
+ Sufficient space is allocated to the return value
+ to hold the suppressed trailing zeros.
+ */
+
+ int bbits, b2, b5, be, dig, i, ieps, ilim0,
+ j, jj1, k, k0, k_check, leftright, m2, m5, s2, s5,
+ spec_case, try_quick;
+ int ilim = 0, ilim1 = 0; /* pacify gcc */
+ Long L;
+#ifndef Sudden_Underflow
+ int denorm;
+ ULong x;
+#endif
+ Bigint *b, *b1, *delta, *mhi, *S;
+ Bigint *mlo = NULL; /* pacify gcc */
+ double d2, ds, eps;
+ char *s, *s0;
+#ifdef Honor_FLT_ROUNDS
+ int rounding;
+#endif
+#ifdef SET_INEXACT
+ int inexact, oldinexact;
+#endif
+
+#ifndef MULTIPLE_THREADS
+ if (dtoa_result) {
+ freedtoa(dtoa_result);
+ dtoa_result = 0;
+ }
+#endif
+
+ if (word0(d) & Sign_bit) {
+ /* set sign for everything, including 0's and NaNs */
+ *sign = 1;
+ word0(d) &= ~Sign_bit; /* clear sign bit */
+ }
+ else
+ *sign = 0;
+
+#if defined(IEEE_Arith) + defined(VAX)
+#ifdef IEEE_Arith
+ if ((word0(d) & Exp_mask) == Exp_mask)
+#else
+ if (word0(d) == 0x8000)
+#endif
+ {
+ /* Infinity or NaN */
+ *decpt = 9999;
+#ifdef IEEE_Arith
+ if (!word1(d) && !(word0(d) & 0xfffff))
+ return nrv_alloc("Infinity", rve, 8);
+#endif
+ return nrv_alloc("NaN", rve, 3);
+ }
+#endif
+#ifdef IBM
+ dval(d) += 0; /* normalize */
+#endif
+ if (!dval(d)) {
+ *decpt = 1;
+ return nrv_alloc("0", rve, 1);
+ }
+
+#ifdef SET_INEXACT
+ try_quick = oldinexact = get_inexact();
+ inexact = 1;
+#endif
+#ifdef Honor_FLT_ROUNDS
+ if ((rounding = Flt_Rounds) >= 2) {
+ if (*sign)
+ rounding = rounding == 2 ? 0 : 2;
+ else
+ if (rounding != 2)
+ rounding = 0;
+ }
+#endif
+
+ b = d2b(dval(d), &be, &bbits);
+ if (b == NULL)
+ return NULL;
+#ifdef Sudden_Underflow
+ i = (int)(word0(d) >> Exp_shift1 & (Exp_mask>>Exp_shift1));
+#else
+ if (( i = (int)(word0(d) >> Exp_shift1 & (Exp_mask>>Exp_shift1)) )!=0) {
+#endif
+ dval(d2) = dval(d);
+ word0(d2) &= Frac_mask1;
+ word0(d2) |= Exp_11;
+#ifdef IBM
+ if (( j = 11 - hi0bits(word0(d2) & Frac_mask) )!=0)
+ dval(d2) /= 1 << j;
+#endif
+
+ /* log(x) ~=~ log(1.5) + (x-1.5)/1.5
+ * log10(x) = log(x) / log(10)
+ * ~=~ log(1.5)/log(10) + (x-1.5)/(1.5*log(10))
+ * log10(d) = (i-Bias)*log(2)/log(10) + log10(d2)
+ *
+ * This suggests computing an approximation k to log10(d) by
+ *
+ * k = (i - Bias)*0.301029995663981
+ * + ( (d2-1.5)*0.289529654602168 + 0.176091259055681 );
+ *
+ * We want k to be too large rather than too small.
+ * The error in the first-order Taylor series approximation
+ * is in our favor, so we just round up the constant enough
+ * to compensate for any error in the multiplication of
+ * (i - Bias) by 0.301029995663981; since |i - Bias| <= 1077,
+ * and 1077 * 0.30103 * 2^-52 ~=~ 7.2e-14,
+ * adding 1e-13 to the constant term more than suffices.
+ * Hence we adjust the constant term to 0.1760912590558.
+ * (We could get a more accurate k by invoking log10,
+ * but this is probably not worthwhile.)
+ */
+
+ i -= Bias;
+#ifdef IBM
+ i <<= 2;
+ i += j;
+#endif
+#ifndef Sudden_Underflow
+ denorm = 0;
+ }
+ else {
+ /* d is denormalized */
+
+ i = bbits + be + (Bias + (P-1) - 1);
+ x = i > 32 ? word0(d) << (64 - i) | word1(d) >> (i - 32)
+ : word1(d) << (32 - i);
+ dval(d2) = (double)x;
+ word0(d2) -= 31*Exp_msk1; /* adjust exponent */
+ i -= (Bias + (P-1) - 1) + 1;
+ denorm = 1;
+ }
+#endif
+ ds = (dval(d2)-1.5)*0.289529654602168 + 0.1760912590558 + i*0.301029995663981;
+ k = (int)ds;
+ if (ds < 0. && ds != k)
+ k--; /* want k = floor(ds) */
+ k_check = 1;
+ if (k >= 0 && k <= Ten_pmax) {
+ if (dval(d) < tens[k])
+ k--;
+ k_check = 0;
+ }
+ j = bbits - i - 1;
+ if (j >= 0) {
+ b2 = 0;
+ s2 = j;
+ }
+ else {
+ b2 = -j;
+ s2 = 0;
+ }
+ if (k >= 0) {
+ b5 = 0;
+ s5 = k;
+ s2 += k;
+ }
+ else {
+ b2 -= k;
+ b5 = -k;
+ s5 = 0;
+ }
+ if (mode < 0 || mode > 9)
+ mode = 0;
+
+#ifndef SET_INEXACT
+#ifdef Check_FLT_ROUNDS
+ try_quick = Rounding == 1;
+#else
+ try_quick = 1;
+#endif
+#endif /*SET_INEXACT*/
+
+ if (mode > 5) {
+ mode -= 4;
+ try_quick = 0;
+ }
+ leftright = 1;
+ switch(mode) {
+ case 0:
+ case 1:
+ ilim = ilim1 = -1;
+ i = 18;
+ ndigits = 0;
+ break;
+ case 2:
+ leftright = 0;
+ /* FALLTHROUGH */
+ case 4:
+ if (ndigits <= 0)
+ ndigits = 1;
+ ilim = ilim1 = i = ndigits;
+ break;
+ case 3:
+ leftright = 0;
+ /* FALLTHROUGH */
+ case 5:
+ i = ndigits + k + 1;
+ ilim = i;
+ ilim1 = i - 1;
+ if (i <= 0)
+ i = 1;
+ }
+ s = s0 = rv_alloc((size_t)i);
+ if (s == NULL)
+ return NULL;
+
+#ifdef Honor_FLT_ROUNDS
+ if (mode > 1 && rounding != 1)
+ leftright = 0;
+#endif
+
+ if (ilim >= 0 && ilim <= Quick_max && try_quick) {
+
+ /* Try to get by with floating-point arithmetic. */
+
+ i = 0;
+ dval(d2) = dval(d);
+ k0 = k;
+ ilim0 = ilim;
+ ieps = 2; /* conservative */
+ if (k > 0) {
+ ds = tens[k&0xf];
+ j = (unsigned int)k >> 4;
+ if (j & Bletch) {
+ /* prevent overflows */
+ j &= Bletch - 1;
+ dval(d) /= bigtens[n_bigtens-1];
+ ieps++;
+ }
+ for(; j; j = (unsigned int)j >> 1, i++)
+ if (j & 1) {
+ ieps++;
+ ds *= bigtens[i];
+ }
+ dval(d) /= ds;
+ }
+ else if (( jj1 = -k )!=0) {
+ dval(d) *= tens[jj1 & 0xf];
+ for(j = jj1 >> 4; j; j >>= 1, i++)
+ if (j & 1) {
+ ieps++;
+ dval(d) *= bigtens[i];
+ }
+ }
+ if (k_check && dval(d) < 1. && ilim > 0) {
+ if (ilim1 <= 0)
+ goto fast_failed;
+ ilim = ilim1;
+ k--;
+ dval(d) *= 10.;
+ ieps++;
+ }
+ dval(eps) = ieps*dval(d) + 7.;
+ word0(eps) -= (P-1)*Exp_msk1;
+ if (ilim == 0) {
+ S = mhi = 0;
+ dval(d) -= 5.;
+ if (dval(d) > dval(eps))
+ goto one_digit;
+ if (dval(d) < -dval(eps))
+ goto no_digits;
+ goto fast_failed;
+ }
+#ifndef No_leftright
+ if (leftright) {
+ /* Use Steele & White method of only
+ * generating digits needed.
+ */
+ dval(eps) = 0.5/tens[ilim-1] - dval(eps);
+ for(i = 0;;) {
+ L = (INT32)dval(d);
+ dval(d) -= L;
+ *s++ = (char)('0' + (int)L);
+ if (dval(d) < dval(eps))
+ goto ret1;
+ if (1. - dval(d) < dval(eps))
+ goto bump_up;
+ if (++i >= ilim)
+ break;
+ dval(eps) *= 10.;
+ dval(d) *= 10.;
+ }
+ }
+ else {
+#endif
+ /* Generate ilim digits, then fix them up. */
+ dval(eps) *= tens[ilim-1];
+ for(i = 1;; i++, dval(d) *= 10.) {
+ L = (Long)(dval(d));
+ if (!(dval(d) -= L))
+ ilim = i;
+ *s++ = (char)('0' + (int)L);
+ if (i == ilim) {
+ if (dval(d) > 0.5 + dval(eps))
+ goto bump_up;
+ else if (dval(d) < 0.5 - dval(eps)) {
+ while(*--s == '0');
+ s++;
+ goto ret1;
+ }
+ break;
+ }
+ }
+#ifndef No_leftright
+ }
+#endif
+ fast_failed:
+ s = s0;
+ dval(d) = dval(d2);
+ k = k0;
+ ilim = ilim0;
+ }
+
+ /* Do we have a "small" integer? */
+
+ if (be >= 0 && k <= Int_max) {
+ /* Yes. */
+ ds = tens[k];
+ if (ndigits < 0 && ilim <= 0) {
+ S = mhi = 0;
+ if (ilim < 0 || dval(d) <= 5*ds)
+ goto no_digits;
+ goto one_digit;
+ }
+ for(i = 1;; i++, dval(d) *= 10.) {
+ L = (Long)(dval(d) / ds);
+ dval(d) -= L*ds;
+#ifdef Check_FLT_ROUNDS
+ /* If FLT_ROUNDS == 2, L will usually be high by 1 */
+ if (dval(d) < 0) {
+ L--;
+ dval(d) += ds;
+ }
+#endif
+ *s++ = (char)('0' + (int)L);
+ if (!dval(d)) {
+#ifdef SET_INEXACT
+ inexact = 0;
+#endif
+ break;
+ }
+ if (i == ilim) {
+#ifdef Honor_FLT_ROUNDS
+ if (mode > 1)
+ switch(rounding) {
+ case 0: goto ret1;
+ case 2: goto bump_up;
+ }
+#endif
+ dval(d) += dval(d);
+ if (dval(d) > ds || (dval(d) == ds && L & 1)) {
+ bump_up:
+ while(*--s == '9')
+ if (s == s0) {
+ k++;
+ *s = '0';
+ break;
+ }
+ ++*s++;
+ }
+ break;
+ }
+ }
+ goto ret1;
+ }
+
+ m2 = b2;
+ m5 = b5;
+ mhi = mlo = 0;
+ if (leftright) {
+ i =
+#ifndef Sudden_Underflow
+ denorm ? be + (Bias + (P-1) - 1 + 1) :
+#endif
+#ifdef IBM
+ 1 + 4*P - 3 - bbits + ((bbits + be - 1) & 3);
+#else
+ 1 + P - bbits;
+#endif
+ b2 += i;
+ s2 += i;
+ mhi = i2b(1);
+ if (mhi == NULL)
+ return NULL;
+ }
+ if (m2 > 0 && s2 > 0) {
+ i = m2 < s2 ? m2 : s2;
+ b2 -= i;
+ m2 -= i;
+ s2 -= i;
+ }
+ if (b5 > 0) {
+ if (leftright) {
+ if (m5 > 0) {
+ mhi = pow5mult(mhi, m5);
+ if (mhi == NULL)
+ return NULL;
+ b1 = mult(mhi, b);
+ if (b1 == NULL)
+ return NULL;
+ Bfree(b);
+ b = b1;
+ }
+ if (( j = b5 - m5 )!=0)
+ b = pow5mult(b, j);
+ if (b == NULL)
+ return NULL;
+ }
+ else
+ b = pow5mult(b, b5);
+ if (b == NULL)
+ return NULL;
+ }
+ S = i2b(1);
+ if (S == NULL)
+ return NULL;
+ if (s5 > 0) {
+ S = pow5mult(S, s5);
+ if (S == NULL)
+ return NULL;
+ }
+
+ /* Check for special case that d is a normalized power of 2. */
+
+ spec_case = 0;
+ if ((mode < 2 || leftright)
+#ifdef Honor_FLT_ROUNDS
+ && rounding == 1
+#endif
+ ) {
+ if (!word1(d) && !(word0(d) & Bndry_mask)
+#ifndef Sudden_Underflow
+ && word0(d) & (Exp_mask & ~Exp_msk1)
+#endif
+ ) {
+ /* The special case */
+ b2 += Log2P;
+ s2 += Log2P;
+ spec_case = 1;
+ }
+ }
+
+ /* Arrange for convenient computation of quotients:
+ * shift left if necessary so divisor has 4 leading 0 bits.
+ *
+ * Perhaps we should just compute leading 28 bits of S once
+ * and for all and pass them and a shift to quorem, so it
+ * can do shifts and ors to compute the numerator for q.
+ */
+#ifdef Pack_32
+ if (( i = ((s5 ? 32 - hi0bits(S->x[S->wds-1]) : 1) + s2) & 0x1f )!=0)
+ i = 32 - i;
+#else
+ if (( i = ((s5 ? 32 - hi0bits(S->x[S->wds-1]) : 1) + s2) & 0xf )!=0)
+ i = 16 - i;
+#endif
+ if (i > 4) {
+ i -= 4;
+ b2 += i;
+ m2 += i;
+ s2 += i;
+ }
+ else if (i < 4) {
+ i += 28;
+ b2 += i;
+ m2 += i;
+ s2 += i;
+ }
+ if (b2 > 0) {
+ b = lshift(b, b2);
+ if (b == NULL)
+ return NULL;
+ }
+ if (s2 > 0) {
+ S = lshift(S, s2);
+ if (S == NULL)
+ return NULL;
+ }
+ if (k_check) {
+ if (cmp(b,S) < 0) {
+ k--;
+ b = multadd(b, 10, 0); /* we botched the k estimate */
+ if (b == NULL)
+ return NULL;
+ if (leftright) {
+ mhi = multadd(mhi, 10, 0);
+ if (mhi == NULL)
+ return NULL;
+ }
+ ilim = ilim1;
+ }
+ }
+ if (ilim <= 0 && (mode == 3 || mode == 5)) {
+ if (ilim < 0 || cmp(b,S = multadd(S,5,0)) <= 0) {
+ /* no digits, fcvt style */
+ no_digits:
+ k = -1 - ndigits;
+ goto ret;
+ }
+ one_digit:
+ *s++ = '1';
+ k++;
+ goto ret;
+ }
+ if (leftright) {
+ if (m2 > 0) {
+ mhi = lshift(mhi, m2);
+ if (mhi == NULL)
+ return NULL;
+ }
+
+ /* Compute mlo -- check for special case
+ * that d is a normalized power of 2.
+ */
+
+ mlo = mhi;
+ if (spec_case) {
+ mhi = Balloc(mhi->k);
+ if (mhi == NULL)
+ return NULL;
+ Bcopy(mhi, mlo);
+ mhi = lshift(mhi, Log2P);
+ if (mhi == NULL)
+ return NULL;
+ }
+
+ for(i = 1;;i++) {
+ dig = quorem(b,S) + '0';
+ /* Do we yet have the shortest decimal string
+ * that will round to d?
+ */
+ j = cmp(b, mlo);
+ delta = diff(S, mhi);
+ if (delta == NULL)
+ return NULL;
+ jj1 = delta->sign ? 1 : cmp(b, delta);
+ Bfree(delta);
+#ifndef ROUND_BIASED
+ if (jj1 == 0 && mode != 1 && !(word1(d) & 1)
+#ifdef Honor_FLT_ROUNDS
+ && rounding >= 1
+#endif
+ ) {
+ if (dig == '9')
+ goto round_9_up;
+ if (j > 0)
+ dig++;
+#ifdef SET_INEXACT
+ else if (!b->x[0] && b->wds <= 1)
+ inexact = 0;
+#endif
+ *s++ = (char)dig;
+ goto ret;
+ }
+#endif
+ if (j < 0 || (j == 0 && mode != 1
+#ifndef ROUND_BIASED
+ && !(word1(d) & 1)
+#endif
+ )) {
+ if (!b->x[0] && b->wds <= 1) {
+#ifdef SET_INEXACT
+ inexact = 0;
+#endif
+ goto accept_dig;
+ }
+#ifdef Honor_FLT_ROUNDS
+ if (mode > 1)
+ switch(rounding) {
+ case 0: goto accept_dig;
+ case 2: goto keep_dig;
+ }
+#endif /*Honor_FLT_ROUNDS*/
+ if (jj1 > 0) {
+ b = lshift(b, 1);
+ if (b == NULL)
+ return NULL;
+ jj1 = cmp(b, S);
+ if ((jj1 > 0 || (jj1 == 0 && dig & 1))
+ && dig++ == '9')
+ goto round_9_up;
+ }
+ accept_dig:
+ *s++ = (char)dig;
+ goto ret;
+ }
+ if (jj1 > 0) {
+#ifdef Honor_FLT_ROUNDS
+ if (!rounding)
+ goto accept_dig;
+#endif
+ if (dig == '9') { /* possible if i == 1 */
+ round_9_up:
+ *s++ = '9';
+ goto roundoff;
+ }
+ *s++ = (char)(dig + 1);
+ goto ret;
+ }
+#ifdef Honor_FLT_ROUNDS
+ keep_dig:
+#endif
+ *s++ = (char)dig;
+ if (i == ilim)
+ break;
+ b = multadd(b, 10, 0);
+ if (b == NULL)
+ return NULL;
+ if (mlo == mhi) {
+ mlo = mhi = multadd(mhi, 10, 0);
+ if (mlo == NULL)
+ return NULL;
+ }
+ else {
+ mlo = multadd(mlo, 10, 0);
+ if (mlo == NULL)
+ return NULL;
+ mhi = multadd(mhi, 10, 0);
+ if (mhi == NULL)
+ return NULL;
+ }
+ }
+ }
+ else
+ for(i = 1;; i++) {
+ *s++ = (char)(dig = (int)(quorem(b,S) + '0'));
+ if (!b->x[0] && b->wds <= 1) {
+#ifdef SET_INEXACT
+ inexact = 0;
+#endif
+ goto ret;
+ }
+ if (i >= ilim)
+ break;
+ b = multadd(b, 10, 0);
+ if (b == NULL)
+ return NULL;
+ }
+
+ /* Round off last digit */
+
+#ifdef Honor_FLT_ROUNDS
+ switch(rounding) {
+ case 0: goto trimzeros;
+ case 2: goto roundoff;
+ }
+#endif
+ b = lshift(b, 1);
+ j = cmp(b, S);
+ if (j > 0 || (j == 0 && dig & 1)) {
+ roundoff:
+ while(*--s == '9')
+ if (s == s0) {
+ k++;
+ *s++ = '1';
+ goto ret;
+ }
+ ++*s++;
+ }
+ else {
+#ifdef Honor_FLT_ROUNDS
+ trimzeros:
+#endif
+ while(*--s == '0');
+ s++;
+ }
+ ret:
+ Bfree(S);
+ if (mhi) {
+ if (mlo && mlo != mhi)
+ Bfree(mlo);
+ Bfree(mhi);
+ }
+ ret1:
+#ifdef SET_INEXACT
+ if (inexact) {
+ if (!oldinexact) {
+ word0(d) = Exp_1 + (70 << Exp_shift);
+ word1(d) = 0;
+ dval(d) += 1.;
+ }
+ }
+ else if (!oldinexact)
+ clear_inexact();
+#endif
+ Bfree(b);
+ if (s == s0) { /* don't return empty string */
+ *s++ = '0';
+ k = 0;
+ }
+ *s = 0;
+ *decpt = k + 1;
+ if (rve)
+ *rve = s;
+ return s0;
+ }
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