| /**************************************************************** |
| * |
| * The author of this software is David M. Gay. |
| * |
| * Copyright (c) 1991 by AT&T. |
| * |
| * Permission to use, copy, modify, and distribute this software for any |
| * purpose without fee is hereby granted, provided that this entire notice |
| * is included in all copies of any software which is or includes a copy |
| * or modification of this software and in all copies of the supporting |
| * documentation for such software. |
| * |
| * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED |
| * WARRANTY. IN PARTICULAR, NEITHER THE AUTHOR NOR AT&T MAKES ANY |
| * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY |
| * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE. |
| * |
| ***************************************************************/ |
| |
| /* Please send bug reports to |
| David M. Gay |
| AT&T Bell Laboratories, Room 2C-463 |
| 600 Mountain Avenue |
| Murray Hill, NJ 07974-2070 |
| U.S.A. |
| dmg@research.att.com or research!dmg |
| */ |
| |
| #include "mprec.h" |
| #include <string.h> |
| |
| static int |
| _DEFUN (quorem, |
| (b, S), |
| _Jv_Bigint * b _AND _Jv_Bigint * S) |
| { |
| int n; |
| long borrow, y; |
| unsigned long carry, q, ys; |
| unsigned long *bx, *bxe, *sx, *sxe; |
| #ifdef Pack_32 |
| long z; |
| unsigned long si, zs; |
| #endif |
| |
| n = S->_wds; |
| #ifdef DEBUG |
| /*debug*/ if (b->_wds > n) |
| /*debug*/ Bug ("oversize b in quorem"); |
| #endif |
| if (b->_wds < n) |
| return 0; |
| sx = S->_x; |
| sxe = sx + --n; |
| bx = b->_x; |
| bxe = bx + n; |
| q = *bxe / (*sxe + 1); /* ensure q <= true quotient */ |
| #ifdef DEBUG |
| /*debug*/ if (q > 9) |
| /*debug*/ Bug ("oversized quotient in quorem"); |
| #endif |
| if (q) |
| { |
| borrow = 0; |
| carry = 0; |
| do |
| { |
| #ifdef Pack_32 |
| si = *sx++; |
| ys = (si & 0xffff) * q + carry; |
| zs = (si >> 16) * q + (ys >> 16); |
| carry = zs >> 16; |
| y = (*bx & 0xffff) - (ys & 0xffff) + borrow; |
| borrow = y >> 16; |
| Sign_Extend (borrow, y); |
| z = (*bx >> 16) - (zs & 0xffff) + borrow; |
| borrow = z >> 16; |
| Sign_Extend (borrow, z); |
| Storeinc (bx, z, y); |
| #else |
| ys = *sx++ * q + carry; |
| carry = ys >> 16; |
| y = *bx - (ys & 0xffff) + borrow; |
| borrow = y >> 16; |
| Sign_Extend (borrow, y); |
| *bx++ = y & 0xffff; |
| #endif |
| } |
| while (sx <= sxe); |
| if (!*bxe) |
| { |
| bx = b->_x; |
| while (--bxe > bx && !*bxe) |
| --n; |
| b->_wds = n; |
| } |
| } |
| if (cmp (b, S) >= 0) |
| { |
| q++; |
| borrow = 0; |
| carry = 0; |
| bx = b->_x; |
| sx = S->_x; |
| do |
| { |
| #ifdef Pack_32 |
| si = *sx++; |
| ys = (si & 0xffff) + carry; |
| zs = (si >> 16) + (ys >> 16); |
| carry = zs >> 16; |
| y = (*bx & 0xffff) - (ys & 0xffff) + borrow; |
| borrow = y >> 16; |
| Sign_Extend (borrow, y); |
| z = (*bx >> 16) - (zs & 0xffff) + borrow; |
| borrow = z >> 16; |
| Sign_Extend (borrow, z); |
| Storeinc (bx, z, y); |
| #else |
| ys = *sx++ + carry; |
| carry = ys >> 16; |
| y = *bx - (ys & 0xffff) + borrow; |
| borrow = y >> 16; |
| Sign_Extend (borrow, y); |
| *bx++ = y & 0xffff; |
| #endif |
| } |
| while (sx <= sxe); |
| bx = b->_x; |
| bxe = bx + n; |
| if (!*bxe) |
| { |
| while (--bxe > bx && !*bxe) |
| --n; |
| b->_wds = n; |
| } |
| } |
| return q; |
| } |
| |
| #ifdef DEBUG |
| #include <stdio.h> |
| |
| void |
| print (_Jv_Bigint * b) |
| { |
| int i, wds; |
| unsigned long *x, y; |
| wds = b->_wds; |
| x = b->_x+wds; |
| i = 0; |
| do |
| { |
| x--; |
| fprintf (stderr, "%08x", *x); |
| } |
| while (++i < wds); |
| fprintf (stderr, "\n"); |
| } |
| #endif |
| |
| /* 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 * |
| _DEFUN (_dtoa_r, |
| (ptr, _d, mode, ndigits, decpt, sign, rve, float_type), |
| struct _Jv_reent *ptr _AND |
| double _d _AND |
| int mode _AND |
| int ndigits _AND |
| int *decpt _AND |
| int *sign _AND |
| char **rve _AND |
| int float_type) |
| { |
| /* |
| float_type == 0 for double precision, 1 for float. |
| |
| 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. |
| 4-9 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). |
| |
| > 16 ==> Floating-point arg is treated as single precision. |
| |
| 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, ilim, ilim0, ilim1, j, j1, k, k0, |
| k_check, leftright, m2, m5, s2, s5, spec_case, try_quick; |
| union double_union d, d2, eps; |
| long L; |
| #ifndef Sudden_Underflow |
| int denorm; |
| unsigned long x; |
| #endif |
| _Jv_Bigint *b, *b1, *delta, *mlo, *mhi, *S; |
| double ds; |
| char *s, *s0; |
| |
| d.d = _d; |
| |
| if (ptr->_result) |
| { |
| ptr->_result->_k = ptr->_result_k; |
| ptr->_result->_maxwds = 1 << ptr->_result_k; |
| Bfree (ptr, ptr->_result); |
| ptr->_result = 0; |
| } |
| |
| 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; |
| s = |
| #ifdef IEEE_Arith |
| !word1 (d) && !(word0 (d) & 0xfffff) ? "Infinity" : |
| #endif |
| "NaN"; |
| if (rve) |
| *rve = |
| #ifdef IEEE_Arith |
| s[3] ? s + 8 : |
| #endif |
| s + 3; |
| return s; |
| } |
| #endif |
| #ifdef IBM |
| d.d += 0; /* normalize */ |
| #endif |
| if (!d.d) |
| { |
| *decpt = 1; |
| s = "0"; |
| if (rve) |
| *rve = s + 1; |
| return s; |
| } |
| |
| b = d2b (ptr, d.d, &be, &bbits); |
| #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)))) |
| { |
| #endif |
| d2.d = d.d; |
| word0 (d2) &= Frac_mask1; |
| word0 (d2) |= Exp_11; |
| #ifdef IBM |
| if (j = 11 - hi0bits (word0 (d2) & Frac_mask)) |
| d2.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.) |
| */ |
| |
| 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); |
| d2.d = x; |
| word0 (d2) -= 31 * Exp_msk1; /* adjust exponent */ |
| i -= (Bias + (P - 1) - 1) + 1; |
| denorm = 1; |
| } |
| #endif |
| ds = (d2.d - 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 (d.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 = 18; |
| 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; |
| } |
| j = sizeof (unsigned long); |
| for (ptr->_result_k = 0; (int) (sizeof (_Jv_Bigint) - sizeof (unsigned long)) + j <= i; |
| j <<= 1) |
| ptr->_result_k++; |
| ptr->_result = Balloc (ptr, ptr->_result_k); |
| s = s0 = (char *) ptr->_result; |
| |
| if (ilim >= 0 && ilim <= Quick_max && try_quick) |
| { |
| /* Try to get by with floating-point arithmetic. */ |
| |
| i = 0; |
| d2.d = d.d; |
| 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; |
| d.d /= bigtens[n_bigtens - 1]; |
| ieps++; |
| } |
| for (; j; j >>= 1, i++) |
| if (j & 1) |
| { |
| ieps++; |
| ds *= bigtens[i]; |
| } |
| d.d /= ds; |
| } |
| else if ((j1 = -k)) |
| { |
| d.d *= tens[j1 & 0xf]; |
| for (j = j1 >> 4; j; j >>= 1, i++) |
| if (j & 1) |
| { |
| ieps++; |
| d.d *= bigtens[i]; |
| } |
| } |
| if (k_check && d.d < 1. && ilim > 0) |
| { |
| if (ilim1 <= 0) |
| goto fast_failed; |
| ilim = ilim1; |
| k--; |
| d.d *= 10.; |
| ieps++; |
| } |
| eps.d = ieps * d.d + 7.; |
| word0 (eps) -= (P - 1) * Exp_msk1; |
| if (ilim == 0) |
| { |
| S = mhi = 0; |
| d.d -= 5.; |
| if (d.d > eps.d) |
| goto one_digit; |
| if (d.d < -eps.d) |
| goto no_digits; |
| goto fast_failed; |
| } |
| #ifndef No_leftright |
| if (leftright) |
| { |
| /* Use Steele & White method of only |
| * generating digits needed. |
| */ |
| eps.d = 0.5 / tens[ilim - 1] - eps.d; |
| for (i = 0;;) |
| { |
| L = d.d; |
| d.d -= L; |
| *s++ = '0' + (int) L; |
| if (d.d < eps.d) |
| goto ret1; |
| if (1. - d.d < eps.d) |
| goto bump_up; |
| if (++i >= ilim) |
| break; |
| eps.d *= 10.; |
| d.d *= 10.; |
| } |
| } |
| else |
| { |
| #endif |
| /* Generate ilim digits, then fix them up. */ |
| eps.d *= tens[ilim - 1]; |
| for (i = 1;; i++, d.d *= 10.) |
| { |
| L = d.d; |
| d.d -= L; |
| *s++ = '0' + (int) L; |
| if (i == ilim) |
| { |
| if (d.d > 0.5 + eps.d) |
| goto bump_up; |
| else if (d.d < 0.5 - eps.d) |
| { |
| while (*--s == '0'); |
| s++; |
| goto ret1; |
| } |
| break; |
| } |
| } |
| #ifndef No_leftright |
| } |
| #endif |
| fast_failed: |
| s = s0; |
| d.d = d2.d; |
| 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 || d.d <= 5 * ds) |
| goto no_digits; |
| goto one_digit; |
| } |
| for (i = 1;; i++) |
| { |
| L = d.d / ds; |
| d.d -= L * ds; |
| #ifdef Check_FLT_ROUNDS |
| /* If FLT_ROUNDS == 2, L will usually be high by 1 */ |
| if (d.d < 0) |
| { |
| L--; |
| d.d += ds; |
| } |
| #endif |
| *s++ = '0' + (int) L; |
| if (i == ilim) |
| { |
| d.d += d.d; |
| if (d.d > ds || (d.d == ds && L & 1)) |
| { |
| bump_up: |
| while (*--s == '9') |
| if (s == s0) |
| { |
| k++; |
| *s = '0'; |
| break; |
| } |
| ++*s++; |
| } |
| break; |
| } |
| if (!(d.d *= 10.)) |
| break; |
| } |
| goto ret1; |
| } |
| |
| m2 = b2; |
| m5 = b5; |
| mhi = mlo = 0; |
| if (leftright) |
| { |
| if (mode < 2) |
| { |
| 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 |
| } |
| 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 (ptr, 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 (ptr, mhi, m5); |
| b1 = mult (ptr, mhi, b); |
| Bfree (ptr, b); |
| b = b1; |
| } |
| if ((j = b5 - m5)) |
| b = pow5mult (ptr, b, j); |
| } |
| else |
| b = pow5mult (ptr, b, b5); |
| } |
| S = i2b (ptr, 1); |
| if (s5 > 0) |
| S = pow5mult (ptr, S, s5); |
| |
| /* Check for special case that d is a normalized power of 2. */ |
| |
| if (mode < 2) |
| { |
| if (!word1 (d) && !(word0 (d) & Bndry_mask) |
| #ifndef Sudden_Underflow |
| && word0(d) & Exp_mask |
| #endif |
| ) |
| { |
| /* The special case */ |
| b2 += Log2P; |
| s2 += Log2P; |
| spec_case = 1; |
| } |
| else |
| spec_case = 0; |
| } |
| |
| /* 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)) |
| i = 32 - i; |
| #else |
| if ((i = ((s5 ? 32 - hi0bits (S->_x[S->_wds - 1]) : 1) + s2) & 0xf)) |
| 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 (ptr, b, b2); |
| if (s2 > 0) |
| S = lshift (ptr, S, s2); |
| if (k_check) |
| { |
| if (cmp (b, S) < 0) |
| { |
| k--; |
| b = multadd (ptr, b, 10, 0); /* we botched the k estimate */ |
| if (leftright) |
| mhi = multadd (ptr, mhi, 10, 0); |
| ilim = ilim1; |
| } |
| } |
| if (ilim <= 0 && mode > 2) |
| { |
| if (ilim < 0 || cmp (b, S = multadd (ptr, 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 (ptr, mhi, m2); |
| |
| /* Single precision case, */ |
| if (float_type) |
| mhi = lshift (ptr, mhi, 29); |
| |
| /* Compute mlo -- check for special case |
| * that d is a normalized power of 2. |
| */ |
| |
| mlo = mhi; |
| if (spec_case) |
| { |
| mhi = Balloc (ptr, mhi->_k); |
| Bcopy (mhi, mlo); |
| mhi = lshift (ptr, mhi, Log2P); |
| } |
| |
| 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 (ptr, S, mhi); |
| j1 = delta->_sign ? 1 : cmp (b, delta); |
| Bfree (ptr, delta); |
| #ifndef ROUND_BIASED |
| if (j1 == 0 && !mode && !(word1 (d) & 1)) |
| { |
| if (dig == '9') |
| goto round_9_up; |
| if (j > 0) |
| dig++; |
| *s++ = dig; |
| goto ret; |
| } |
| #endif |
| if (j < 0 || (j == 0 && !mode |
| #ifndef ROUND_BIASED |
| && !(word1 (d) & 1) |
| #endif |
| )) |
| { |
| if (j1 > 0) |
| { |
| b = lshift (ptr, b, 1); |
| j1 = cmp (b, S); |
| if ((j1 > 0 || (j1 == 0 && dig & 1)) |
| && dig++ == '9') |
| goto round_9_up; |
| } |
| *s++ = dig; |
| goto ret; |
| } |
| if (j1 > 0) |
| { |
| if (dig == '9') |
| { /* possible if i == 1 */ |
| round_9_up: |
| *s++ = '9'; |
| goto roundoff; |
| } |
| *s++ = dig + 1; |
| goto ret; |
| } |
| *s++ = dig; |
| if (i == ilim) |
| break; |
| b = multadd (ptr, b, 10, 0); |
| if (mlo == mhi) |
| mlo = mhi = multadd (ptr, mhi, 10, 0); |
| else |
| { |
| mlo = multadd (ptr, mlo, 10, 0); |
| mhi = multadd (ptr, mhi, 10, 0); |
| } |
| } |
| } |
| else |
| for (i = 1;; i++) |
| { |
| *s++ = dig = quorem (b, S) + '0'; |
| if (i >= ilim) |
| break; |
| b = multadd (ptr, b, 10, 0); |
| } |
| |
| /* Round off last digit */ |
| |
| b = lshift (ptr, 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 |
| { |
| while (*--s == '0'); |
| s++; |
| } |
| ret: |
| Bfree (ptr, S); |
| if (mhi) |
| { |
| if (mlo && mlo != mhi) |
| Bfree (ptr, mlo); |
| Bfree (ptr, mhi); |
| } |
| ret1: |
| Bfree (ptr, b); |
| *s = 0; |
| *decpt = k + 1; |
| if (rve) |
| *rve = s; |
| return s0; |
| } |
| |
| |
| _VOID |
| _DEFUN (_dtoa, |
| (_d, mode, ndigits, decpt, sign, rve, buf, float_type), |
| double _d _AND |
| int mode _AND |
| int ndigits _AND |
| int *decpt _AND |
| int *sign _AND |
| char **rve _AND |
| char *buf _AND |
| int float_type) |
| { |
| struct _Jv_reent reent; |
| char *p; |
| memset (&reent, 0, sizeof reent); |
| |
| p = _dtoa_r (&reent, _d, mode, ndigits, decpt, sign, rve, float_type); |
| strcpy (buf, p); |
| |
| return; |
| } |