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764 lines
17 KiB
764 lines
17 KiB
/**************************************************************** |
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|
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The author of this software is David M. Gay. |
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|
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Copyright (C) 1998, 1999 by Lucent Technologies |
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All Rights Reserved |
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|
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Permission to use, copy, modify, and distribute this software and |
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its documentation for any purpose and without fee is hereby |
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granted, provided that the above copyright notice appear in all |
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copies and that both that the copyright notice and this |
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permission notice and warranty disclaimer appear in supporting |
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documentation, and that the name of Lucent or any of its entities |
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not be used in advertising or publicity pertaining to |
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distribution of the software without specific, written prior |
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permission. |
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|
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LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, |
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INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. |
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IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY |
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SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
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WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER |
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IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, |
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ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF |
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THIS SOFTWARE. |
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|
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****************************************************************/ |
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|
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/* Please send bug reports to |
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David M. Gay |
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Bell Laboratories, Room 2C-463 |
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600 Mountain Avenue |
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Murray Hill, NJ 07974-0636 |
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U.S.A. |
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dmg@bell-labs.com |
|
*/ |
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|
|
#include "gdtoaimp.h" |
|
|
|
static Bigint * |
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#ifdef KR_headers |
|
bitstob(bits, nbits, bbits) ULong *bits; int nbits; int *bbits; |
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#else |
|
bitstob(ULong *bits, int nbits, int *bbits) |
|
#endif |
|
{ |
|
int i, k; |
|
Bigint *b; |
|
ULong *be, *x, *x0; |
|
|
|
i = ULbits; |
|
k = 0; |
|
while(i < nbits) { |
|
i <<= 1; |
|
k++; |
|
} |
|
#ifndef Pack_32 |
|
if (!k) |
|
k = 1; |
|
#endif |
|
b = Balloc(k); |
|
be = bits + ((nbits - 1) >> kshift); |
|
x = x0 = b->x; |
|
do { |
|
*x++ = *bits & ALL_ON; |
|
#ifdef Pack_16 |
|
*x++ = (*bits >> 16) & ALL_ON; |
|
#endif |
|
} while(++bits <= be); |
|
i = x - x0; |
|
while(!x0[--i]) |
|
if (!i) { |
|
b->wds = 0; |
|
*bbits = 0; |
|
goto ret; |
|
} |
|
b->wds = i + 1; |
|
*bbits = i*ULbits + 32 - hi0bits(b->x[i]); |
|
ret: |
|
return b; |
|
} |
|
|
|
/* 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. 92-101]. |
|
* |
|
* 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. |
|
*/ |
|
|
|
char * |
|
gdtoa |
|
#ifdef KR_headers |
|
(fpi, be, bits, kindp, mode, ndigits, decpt, rve) |
|
FPI *fpi; int be; ULong *bits; |
|
int *kindp, mode, ndigits, *decpt; char **rve; |
|
#else |
|
(FPI *fpi, int be, ULong *bits, int *kindp, int mode, int ndigits, int *decpt, char **rve) |
|
#endif |
|
{ |
|
/* Arguments ndigits and decpt are similar to the second and third |
|
arguments 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. |
|
4-9 should give the same return values as 2-3, i.e., |
|
4 <= mode <= 9 ==> same return as mode |
|
2 + (mode & 1). These modes are mainly for |
|
debugging; often they run slower but sometimes |
|
faster than modes 2-3. |
|
4,5,8,9 ==> left-to-right digit generation. |
|
6-9 ==> 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, be0, dig, i, ieps, ilim, ilim0, ilim1, inex; |
|
int j, j1, k, k0, k_check, kind, leftright, m2, m5, nbits; |
|
int rdir, s2, s5, spec_case, try_quick; |
|
Long L; |
|
Bigint *b, *b1, *delta, *mlo, *mhi, *mhi1, *S; |
|
double d, d2, ds, eps; |
|
char *s, *s0; |
|
|
|
#ifndef MULTIPLE_THREADS |
|
if (dtoa_result) { |
|
freedtoa(dtoa_result); |
|
dtoa_result = 0; |
|
} |
|
#endif |
|
inex = 0; |
|
kind = *kindp &= ~STRTOG_Inexact; |
|
switch(kind & STRTOG_Retmask) { |
|
case STRTOG_Zero: |
|
goto ret_zero; |
|
case STRTOG_Normal: |
|
case STRTOG_Denormal: |
|
break; |
|
case STRTOG_Infinite: |
|
*decpt = -32768; |
|
return nrv_alloc("Infinity", rve, 8); |
|
case STRTOG_NaN: |
|
*decpt = -32768; |
|
return nrv_alloc("NaN", rve, 3); |
|
default: |
|
return 0; |
|
} |
|
b = bitstob(bits, nbits = fpi->nbits, &bbits); |
|
be0 = be; |
|
if ( (i = trailz(b)) !=0) { |
|
rshift(b, i); |
|
be += i; |
|
bbits -= i; |
|
} |
|
if (!b->wds) { |
|
Bfree(b); |
|
ret_zero: |
|
*decpt = 1; |
|
return nrv_alloc("0", rve, 1); |
|
} |
|
|
|
dval(d) = b2d(b, &i); |
|
i = be + bbits - 1; |
|
word0(d) &= Frac_mask1; |
|
word0(d) |= Exp_11; |
|
#ifdef IBM |
|
if ( (j = 11 - hi0bits(word0(d) & Frac_mask)) !=0) |
|
dval(d) /= 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.) |
|
*/ |
|
#ifdef IBM |
|
i <<= 2; |
|
i += j; |
|
#endif |
|
ds = (dval(d)-1.5)*0.289529654602168 + 0.1760912590558 + i*0.301029995663981; |
|
|
|
/* correct assumption about exponent range */ |
|
if ((j = i) < 0) |
|
j = -j; |
|
if ((j -= 1077) > 0) |
|
ds += j * 7e-17; |
|
|
|
k = (int)ds; |
|
if (ds < 0. && ds != k) |
|
k--; /* want k = floor(ds) */ |
|
k_check = 1; |
|
#ifdef IBM |
|
j = be + bbits - 1; |
|
if ( (j1 = j & 3) !=0) |
|
dval(d) *= 1 << j1; |
|
word0(d) += j << Exp_shift - 2 & Exp_mask; |
|
#else |
|
word0(d) += (be + bbits - 1) << Exp_shift; |
|
#endif |
|
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; |
|
try_quick = 1; |
|
if (mode > 5) { |
|
mode -= 4; |
|
try_quick = 0; |
|
} |
|
leftright = 1; |
|
switch(mode) { |
|
case 0: |
|
case 1: |
|
ilim = ilim1 = -1; |
|
i = (int)(nbits * .30103) + 3; |
|
ndigits = 0; |
|
break; |
|
case 2: |
|
leftright = 0; |
|
/* no break */ |
|
case 4: |
|
if (ndigits <= 0) |
|
ndigits = 1; |
|
ilim = ilim1 = i = ndigits; |
|
break; |
|
case 3: |
|
leftright = 0; |
|
/* no break */ |
|
case 5: |
|
i = ndigits + k + 1; |
|
ilim = i; |
|
ilim1 = i - 1; |
|
if (i <= 0) |
|
i = 1; |
|
} |
|
s = s0 = rv_alloc(i); |
|
|
|
if ( (rdir = fpi->rounding - 1) !=0) { |
|
if (rdir < 0) |
|
rdir = 2; |
|
if (kind & STRTOG_Neg) |
|
rdir = 3 - rdir; |
|
} |
|
|
|
/* Now rdir = 0 ==> round near, 1 ==> round up, 2 ==> round down. */ |
|
|
|
if (ilim >= 0 && ilim <= Quick_max && try_quick && !rdir |
|
#ifndef IMPRECISE_INEXACT |
|
&& k == 0 |
|
#endif |
|
) { |
|
|
|
/* Try to get by with floating-point arithmetic. */ |
|
|
|
i = 0; |
|
d2 = dval(d); |
|
#ifdef IBM |
|
if ( (j = 11 - hi0bits(word0(d) & Frac_mask)) !=0) |
|
dval(d) /= 1 << j; |
|
#endif |
|
k0 = k; |
|
ilim0 = ilim; |
|
ieps = 2; /* conservative */ |
|
if (k > 0) { |
|
ds = tens[k&0xf]; |
|
j = k >> 4; |
|
if (j & Bletch) { |
|
/* prevent overflows */ |
|
j &= Bletch - 1; |
|
dval(d) /= bigtens[n_bigtens-1]; |
|
ieps++; |
|
} |
|
for(; j; j >>= 1, i++) |
|
if (j & 1) { |
|
ieps++; |
|
ds *= bigtens[i]; |
|
} |
|
} |
|
else { |
|
ds = 1.; |
|
if ( (j1 = -k) !=0) { |
|
dval(d) *= tens[j1 & 0xf]; |
|
for(j = j1 >> 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) = ds*0.5/tens[ilim-1] - dval(eps); |
|
for(i = 0;;) { |
|
L = (Long)(dval(d)/ds); |
|
dval(d) -= L*ds; |
|
*s++ = '0' + (int)L; |
|
if (dval(d) < dval(eps)) { |
|
if (dval(d)) |
|
inex = STRTOG_Inexlo; |
|
goto ret1; |
|
} |
|
if (ds - 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.) { |
|
if ( (L = (Long)(dval(d)/ds)) !=0) |
|
dval(d) -= L*ds; |
|
*s++ = '0' + (int)L; |
|
if (i == ilim) { |
|
ds *= 0.5; |
|
if (dval(d) > ds + dval(eps)) |
|
goto bump_up; |
|
else if (dval(d) < ds - dval(eps)) { |
|
while(*--s == '0'){} |
|
s++; |
|
if (dval(d)) |
|
inex = STRTOG_Inexlo; |
|
goto ret1; |
|
} |
|
break; |
|
} |
|
} |
|
#ifndef No_leftright |
|
} |
|
#endif |
|
fast_failed: |
|
s = s0; |
|
dval(d) = 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 = 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++ = '0' + (int)L; |
|
if (dval(d) == 0.) |
|
break; |
|
if (i == ilim) { |
|
if (rdir) { |
|
if (rdir == 1) |
|
goto bump_up; |
|
inex = STRTOG_Inexlo; |
|
goto ret1; |
|
} |
|
dval(d) += dval(d); |
|
if (dval(d) > ds || dval(d) == ds && L & 1) { |
|
bump_up: |
|
inex = STRTOG_Inexhi; |
|
while(*--s == '9') |
|
if (s == s0) { |
|
k++; |
|
*s = '0'; |
|
break; |
|
} |
|
++*s++; |
|
} |
|
else |
|
inex = STRTOG_Inexlo; |
|
break; |
|
} |
|
} |
|
goto ret1; |
|
} |
|
|
|
m2 = b2; |
|
m5 = b5; |
|
mhi = mlo = 0; |
|
if (leftright) { |
|
if (mode < 2) { |
|
i = nbits - bbits; |
|
if (be - i++ < fpi->emin) |
|
/* denormal */ |
|
i = be - fpi->emin + 1; |
|
} |
|
else { |
|
j = ilim - 1; |
|
if (m5 >= j) |
|
m5 -= j; |
|
else { |
|
s5 += j -= m5; |
|
b5 += j; |
|
m5 = 0; |
|
} |
|
if ((i = ilim) < 0) { |
|
m2 -= i; |
|
i = 0; |
|
} |
|
} |
|
b2 += i; |
|
s2 += i; |
|
mhi = i2b(1); |
|
} |
|
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); |
|
b1 = mult(mhi, b); |
|
Bfree(b); |
|
b = b1; |
|
} |
|
if ( (j = b5 - m5) !=0) |
|
b = pow5mult(b, j); |
|
} |
|
else |
|
b = pow5mult(b, b5); |
|
} |
|
S = i2b(1); |
|
if (s5 > 0) |
|
S = pow5mult(S, s5); |
|
|
|
/* Check for special case that d is a normalized power of 2. */ |
|
|
|
spec_case = 0; |
|
if (mode < 2) { |
|
if (bbits == 1 && be0 > fpi->emin + 1) { |
|
/* The special case */ |
|
b2++; |
|
s2++; |
|
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 (s2 > 0) |
|
S = lshift(S, s2); |
|
if (k_check) { |
|
if (cmp(b,S) < 0) { |
|
k--; |
|
b = multadd(b, 10, 0); /* we botched the k estimate */ |
|
if (leftright) |
|
mhi = multadd(mhi, 10, 0); |
|
ilim = ilim1; |
|
} |
|
} |
|
if (ilim <= 0 && mode > 2) { |
|
if (ilim < 0 || cmp(b,S = multadd(S,5,0)) <= 0) { |
|
/* no digits, fcvt style */ |
|
no_digits: |
|
k = -1 - ndigits; |
|
inex = STRTOG_Inexlo; |
|
goto ret; |
|
} |
|
one_digit: |
|
inex = STRTOG_Inexhi; |
|
*s++ = '1'; |
|
k++; |
|
goto ret; |
|
} |
|
if (leftright) { |
|
if (m2 > 0) |
|
mhi = lshift(mhi, m2); |
|
|
|
/* Compute mlo -- check for special case |
|
* that d is a normalized power of 2. |
|
*/ |
|
|
|
mlo = mhi; |
|
if (spec_case) { |
|
mhi = Balloc(mhi->k); |
|
Bcopy(mhi, mlo); |
|
mhi = lshift(mhi, 1); |
|
} |
|
|
|
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); |
|
j1 = delta->sign ? 1 : cmp(b, delta); |
|
Bfree(delta); |
|
#ifndef ROUND_BIASED |
|
if (j1 == 0 && !mode && !(bits[0] & 1) && !rdir) { |
|
if (dig == '9') |
|
goto round_9_up; |
|
if (j <= 0) { |
|
if (b->wds > 1 || b->x[0]) |
|
inex = STRTOG_Inexlo; |
|
} |
|
else { |
|
dig++; |
|
inex = STRTOG_Inexhi; |
|
} |
|
*s++ = dig; |
|
goto ret; |
|
} |
|
#endif |
|
if (j < 0 || j == 0 && !mode |
|
#ifndef ROUND_BIASED |
|
&& !(bits[0] & 1) |
|
#endif |
|
) { |
|
if (rdir && (b->wds > 1 || b->x[0])) { |
|
if (rdir == 2) { |
|
inex = STRTOG_Inexlo; |
|
goto accept; |
|
} |
|
while (cmp(S,mhi) > 0) { |
|
*s++ = dig; |
|
mhi1 = multadd(mhi, 10, 0); |
|
if (mlo == mhi) |
|
mlo = mhi1; |
|
mhi = mhi1; |
|
b = multadd(b, 10, 0); |
|
dig = quorem(b,S) + '0'; |
|
} |
|
if (dig++ == '9') |
|
goto round_9_up; |
|
inex = STRTOG_Inexhi; |
|
goto accept; |
|
} |
|
if (j1 > 0) { |
|
b = lshift(b, 1); |
|
j1 = cmp(b, S); |
|
if ((j1 > 0 || j1 == 0 && dig & 1) |
|
&& dig++ == '9') |
|
goto round_9_up; |
|
inex = STRTOG_Inexhi; |
|
} |
|
if (b->wds > 1 || b->x[0]) |
|
inex = STRTOG_Inexlo; |
|
accept: |
|
*s++ = dig; |
|
goto ret; |
|
} |
|
if (j1 > 0 && rdir != 2) { |
|
if (dig == '9') { /* possible if i == 1 */ |
|
round_9_up: |
|
*s++ = '9'; |
|
inex = STRTOG_Inexhi; |
|
goto roundoff; |
|
} |
|
inex = STRTOG_Inexhi; |
|
*s++ = dig + 1; |
|
goto ret; |
|
} |
|
*s++ = dig; |
|
if (i == ilim) |
|
break; |
|
b = multadd(b, 10, 0); |
|
if (mlo == mhi) |
|
mlo = mhi = multadd(mhi, 10, 0); |
|
else { |
|
mlo = multadd(mlo, 10, 0); |
|
mhi = multadd(mhi, 10, 0); |
|
} |
|
} |
|
} |
|
else |
|
for(i = 1;; i++) { |
|
*s++ = dig = quorem(b,S) + '0'; |
|
if (i >= ilim) |
|
break; |
|
b = multadd(b, 10, 0); |
|
} |
|
|
|
/* Round off last digit */ |
|
|
|
if (rdir) { |
|
if (rdir == 2 || b->wds <= 1 && !b->x[0]) |
|
goto chopzeros; |
|
goto roundoff; |
|
} |
|
b = lshift(b, 1); |
|
j = cmp(b, S); |
|
if (j > 0 || j == 0 && dig & 1) { |
|
roundoff: |
|
inex = STRTOG_Inexhi; |
|
while(*--s == '9') |
|
if (s == s0) { |
|
k++; |
|
*s++ = '1'; |
|
goto ret; |
|
} |
|
++*s++; |
|
} |
|
else { |
|
chopzeros: |
|
if (b->wds > 1 || b->x[0]) |
|
inex = STRTOG_Inexlo; |
|
while(*--s == '0'){} |
|
s++; |
|
} |
|
ret: |
|
Bfree(S); |
|
if (mhi) { |
|
if (mlo && mlo != mhi) |
|
Bfree(mlo); |
|
Bfree(mhi); |
|
} |
|
ret1: |
|
Bfree(b); |
|
*s = 0; |
|
*decpt = k + 1; |
|
if (rve) |
|
*rve = s; |
|
*kindp |= inex; |
|
return s0; |
|
}
|
|
|