mirror of
https://github.com/jart/cosmopolitan.git
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Clean up gdtoa code
This commit is contained in:
Justine Tunney
parent
7341336b1a
commit
da45c7c80b
48 changed files with 2808 additions and 4721 deletions
587
third_party/gdtoa/dtoa.c
vendored
587
third_party/gdtoa/dtoa.c
vendored
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@ -1,36 +1,37 @@
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/*-*- mode:c;indent-tabs-mode:t;c-basic-offset:8;tab-width:8;coding:utf-8 -*-│
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│vi: set et ft=c ts=8 tw=8 fenc=utf-8 :vi│
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╚──────────────────────────────────────────────────────────────────────────────╝
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│ │
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│ The author of this software is David M. Gay. │
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│ Please send bug reports to David M. Gay <dmg@acm.org> │
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│ or Justine Tunney <jtunney@gmail.com> │
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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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#include "libc/runtime/fenv.h"
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#include "third_party/gdtoa/gdtoa.internal.h"
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/* clang-format off */
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/****************************************************************
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The author of this software is David M. Gay.
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Copyright (C) 1998, 1999 by Lucent Technologies
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All Rights Reserved
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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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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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/* Please send bug reports to David M. Gay (dmg at acm dot org,
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* with " at " changed at "@" and " dot " changed to "."). */
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/* dtoa for IEEE arithmetic (dmg): convert double to ASCII string.
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*
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@ -66,149 +67,86 @@ THIS SOFTWARE.
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* calculation.
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*/
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#ifdef Honor_FLT_ROUNDS
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#undef Check_FLT_ROUNDS
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#define Check_FLT_ROUNDS
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#else
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#define Rounding Flt_Rounds
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#endif
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char *
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dtoa(double d0, int mode, int ndigits, int *decpt, int *sign, char **rve)
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{
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/* Arguments ndigits, decpt, sign are similar to those
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of ecvt and fcvt; trailing zeros are suppressed from
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the returned string. If not null, *rve is set to point
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to the end of the return value. If d is +-Infinity or NaN,
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then *decpt is set to 9999.
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/* Arguments ndigits, decpt, sign are similar to those
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of ecvt and fcvt; trailing zeros are suppressed from
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the returned string. If not null, *rve is set to point
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to the end of the return value. If d is +-Infinity or NaN,
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then *decpt is set to 9999.
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mode:
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mode:
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0 ==> shortest string that yields d when read in
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and rounded to nearest.
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and rounded to nearest.
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1 ==> like 0, but with Steele & White stopping rule;
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e.g. with IEEE P754 arithmetic , mode 0 gives
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1e23 whereas mode 1 gives 9.999999999999999e22.
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e.g. with IEEE P754 arithmetic , mode 0 gives
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1e23 whereas mode 1 gives 9.999999999999999e22.
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2 ==> max(1,ndigits) significant digits. This gives a
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return value similar to that of ecvt, except
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that trailing zeros are suppressed.
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return value similar to that of ecvt, except
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that trailing zeros are suppressed.
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3 ==> through ndigits past the decimal point. This
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gives a return value similar to that from fcvt,
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except that trailing zeros are suppressed, and
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ndigits can be negative.
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gives a return value similar to that from fcvt,
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except that trailing zeros are suppressed, and
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ndigits can be negative.
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4,5 ==> similar to 2 and 3, respectively, but (in
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round-nearest mode) with the tests of mode 0 to
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possibly return a shorter string that rounds to d.
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With IEEE arithmetic and compilation with
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-DHonor_FLT_ROUNDS, modes 4 and 5 behave the same
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as modes 2 and 3 when FLT_ROUNDS != 1.
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round-nearest mode) with the tests of mode 0 to
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possibly return a shorter string that rounds to d.
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With IEEE arithmetic and compilation with
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-DHonor_FLT_ROUNDS, modes 4 and 5 behave the same
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as modes 2 and 3 when FLT_ROUNDS != 1.
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6-9 ==> Debugging modes similar to mode - 4: don't try
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fast floating-point estimate (if applicable).
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fast floating-point estimate (if applicable).
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Values of mode other than 0-9 are treated as mode 0.
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Sufficient space is allocated to the return value
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to hold the suppressed trailing zeros.
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*/
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#ifdef MULTIPLE_THREADS
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ThInfo *TI = 0;
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#endif
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int bbits, b2, b5, be, dig, i, ieps, ilim, ilim0, ilim1,
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j, j1, k, k0, k_check, leftright, m2, m5, s2, s5,
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spec_case, try_quick;
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Long L;
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#ifndef Sudden_Underflow
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int denorm;
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ULong x;
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#endif
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Bigint *b, *b1, *delta, *mlo, *mhi, *S;
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U d, d2, eps, eps1;
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double ds;
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char *s, *s0;
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#ifdef SET_INEXACT
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int inexact, oldinexact;
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#endif
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#ifdef Honor_FLT_ROUNDS /*{*/
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int Rounding;
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#ifdef Trust_FLT_ROUNDS /*{{ only define this if FLT_ROUNDS really works! */
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Rounding = Flt_Rounds;
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#else /*}{*/
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Rounding = 1;
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switch(fegetround()) {
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case FE_TOWARDZERO: Rounding = 0; break;
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case FE_UPWARD: Rounding = 2; break;
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case FE_DOWNWARD: Rounding = 3;
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}
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#endif /*}}*/
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#endif /*}*/
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#ifndef MULTIPLE_THREADS
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if (dtoa_result) {
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freedtoa(dtoa_result);
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dtoa_result = 0;
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}
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#endif
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Rounding = FLT_ROUNDS;
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d.d = d0;
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if (word0(&d) & Sign_bit) {
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/* set sign for everything, including 0's and NaNs */
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*sign = 1;
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word0(&d) &= ~Sign_bit; /* clear sign bit */
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}
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}
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else
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*sign = 0;
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#if defined(IEEE_Arith) + defined(VAX)
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#ifdef IEEE_Arith
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if ((word0(&d) & Exp_mask) == Exp_mask)
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#else
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if (word0(&d) == 0x8000)
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#endif
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{
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{
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/* Infinity or NaN */
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*decpt = 9999;
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#ifdef IEEE_Arith
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if (!word1(&d) && !(word0(&d) & 0xfffff))
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return nrv_alloc("Infinity", rve, 8 MTb);
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#endif
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return nrv_alloc("NaN", rve, 3 MTb);
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}
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#endif
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#ifdef IBM
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dval(&d) += 0; /* normalize */
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#endif
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return nrv_alloc("Infinity", rve, 8);
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return nrv_alloc("NaN", rve, 3);
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}
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if (!dval(&d)) {
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*decpt = 1;
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return nrv_alloc("0", rve, 1 MTb);
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}
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#ifdef SET_INEXACT
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try_quick = oldinexact = get_inexact();
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inexact = 1;
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#endif
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#ifdef Honor_FLT_ROUNDS
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return nrv_alloc("0", rve, 1);
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}
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if (Rounding >= 2) {
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if (*sign)
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Rounding = Rounding == 2 ? 0 : 2;
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else
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if (Rounding != 2)
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Rounding = 0;
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}
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#endif
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b = d2b(dval(&d), &be, &bbits MTb);
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#ifdef Sudden_Underflow
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i = (int)(word0(&d) >> Exp_shift1 & (Exp_mask>>Exp_shift1));
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#else
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}
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b = d2b(dval(&d), &be, &bbits);
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if (( i = (int)(word0(&d) >> Exp_shift1 & (Exp_mask>>Exp_shift1)) )!=0) {
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#endif
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dval(&d2) = dval(&d);
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word0(&d2) &= Frac_mask1;
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word0(&d2) |= Exp_11;
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#ifdef IBM
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if (( j = 11 - hi0bits(word0(&d2) & Frac_mask) )!=0)
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dval(&d2) /= 1 << j;
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#endif
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/* log(x) ~=~ log(1.5) + (x-1.5)/1.5
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* log10(x) = log(x) / log(10)
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* ~=~ log(1.5)/log(10) + (x-1.5)/(1.5*log(10))
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@ -230,27 +168,19 @@ dtoa(double d0, int mode, int ndigits, int *decpt, int *sign, char **rve)
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* (We could get a more accurate k by invoking log10,
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* but this is probably not worthwhile.)
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*/
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i -= Bias;
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#ifdef IBM
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i <<= 2;
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i += j;
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#endif
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#ifndef Sudden_Underflow
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denorm = 0;
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}
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}
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else {
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/* d is denormalized */
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i = bbits + be + (Bias + (P-1) - 1);
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x = i > 32 ? word0(&d) << (64 - i) | word1(&d) >> (i - 32)
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: word1(&d) << (32 - i);
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: word1(&d) << (32 - i);
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dval(&d2) = x;
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word0(&d2) -= 31*Exp_msk1; /* adjust exponent */
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i -= (Bias + (P-1) - 1) + 1;
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denorm = 1;
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}
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#endif
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}
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ds = (dval(&d2)-1.5)*0.289529654602168 + 0.1760912590558 + i*0.301029995663981;
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k = (int)ds;
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if (ds < 0. && ds != k)
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@ -260,79 +190,66 @@ dtoa(double d0, int mode, int ndigits, int *decpt, int *sign, char **rve)
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if (dval(&d) < tens[k])
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k--;
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k_check = 0;
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}
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}
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j = bbits - i - 1;
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if (j >= 0) {
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b2 = 0;
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s2 = j;
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}
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}
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else {
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b2 = -j;
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s2 = 0;
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}
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}
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if (k >= 0) {
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b5 = 0;
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s5 = k;
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s2 += k;
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}
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}
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else {
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b2 -= k;
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b5 = -k;
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s5 = 0;
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}
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}
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if (mode < 0 || mode > 9)
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mode = 0;
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#ifndef SET_INEXACT
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#ifdef Check_FLT_ROUNDS
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try_quick = Rounding == 1;
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#else
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try_quick = 1;
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#endif
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#endif /*SET_INEXACT*/
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if (mode > 5) {
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mode -= 4;
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try_quick = 0;
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}
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}
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leftright = 1;
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ilim = ilim1 = -1; /* Values for cases 0 and 1; done here to */
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/* silence erroneous "gcc -Wall" warning. */
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switch(mode) {
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case 0:
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case 1:
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i = 18;
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ndigits = 0;
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break;
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case 2:
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leftright = 0;
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/* no break */
|
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case 4:
|
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if (ndigits <= 0)
|
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ndigits = 1;
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ilim = ilim1 = i = ndigits;
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break;
|
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case 3:
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leftright = 0;
|
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/* no break */
|
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case 5:
|
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i = ndigits + k + 1;
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ilim = i;
|
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ilim1 = i - 1;
|
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if (i <= 0)
|
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i = 1;
|
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}
|
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s = s0 = rv_alloc(i MTb);
|
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|
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#ifdef Honor_FLT_ROUNDS
|
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case 0:
|
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case 1:
|
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i = 18;
|
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ndigits = 0;
|
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break;
|
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case 2:
|
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leftright = 0;
|
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/* no break */
|
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case 4:
|
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if (ndigits <= 0)
|
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ndigits = 1;
|
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ilim = ilim1 = i = ndigits;
|
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break;
|
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case 3:
|
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leftright = 0;
|
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/* no break */
|
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case 5:
|
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i = ndigits + k + 1;
|
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ilim = i;
|
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ilim1 = i - 1;
|
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if (i <= 0)
|
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i = 1;
|
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}
|
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s = s0 = rv_alloc(i);
|
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if (mode > 1 && Rounding != 1)
|
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leftright = 0;
|
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#endif
|
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|
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if (ilim >= 0 && ilim <= Quick_max && try_quick) {
|
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|
||||
/* Try to get by with floating-point arithmetic. */
|
||||
|
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i = 0;
|
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j1 = 0;
|
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dval(&d2) = dval(&d);
|
||||
|
|
@ -347,22 +264,22 @@ dtoa(double d0, int mode, int ndigits, int *decpt, int *sign, char **rve)
|
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j &= Bletch - 1;
|
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dval(&d) /= bigtens[n_bigtens-1];
|
||||
ieps++;
|
||||
}
|
||||
}
|
||||
for(; j; j >>= 1, i++)
|
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if (j & 1) {
|
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ieps++;
|
||||
ds *= bigtens[i];
|
||||
}
|
||||
}
|
||||
dval(&d) /= ds;
|
||||
}
|
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}
|
||||
else if (( j1 = -k )!=0) {
|
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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;
|
||||
|
|
@ -370,7 +287,7 @@ dtoa(double d0, int mode, int ndigits, int *decpt, int *sign, char **rve)
|
|||
k--;
|
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dval(&d) *= 10.;
|
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ieps++;
|
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}
|
||||
}
|
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dval(&eps) = ieps*dval(&d) + 7.;
|
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word0(&eps) -= (P-1)*Exp_msk1;
|
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if (ilim == 0) {
|
||||
|
|
@ -381,8 +298,7 @@ dtoa(double d0, int mode, int ndigits, int *decpt, int *sign, char **rve)
|
|||
if (dval(&d) < -dval(&eps))
|
||||
goto no_digits;
|
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goto fast_failed;
|
||||
}
|
||||
#ifndef No_leftright
|
||||
}
|
||||
if (leftright) {
|
||||
/* Use Steele & White method of only
|
||||
* generating digits needed.
|
||||
|
|
@ -402,8 +318,8 @@ dtoa(double d0, int mode, int ndigits, int *decpt, int *sign, char **rve)
|
|||
*s++ = '1';
|
||||
++k;
|
||||
goto ret1;
|
||||
}
|
||||
}
|
||||
}
|
||||
for(i = 0;;) {
|
||||
L = dval(&d);
|
||||
dval(&d) -= L;
|
||||
|
|
@ -416,10 +332,9 @@ dtoa(double d0, int mode, int ndigits, int *decpt, int *sign, char **rve)
|
|||
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.) {
|
||||
|
|
@ -433,20 +348,17 @@ dtoa(double d0, int mode, int ndigits, int *decpt, int *sign, char **rve)
|
|||
else if (dval(&d) < 0.5 - dval(&eps))
|
||||
goto retc;
|
||||
break;
|
||||
}
|
||||
}
|
||||
#ifndef No_leftright
|
||||
}
|
||||
#endif
|
||||
fast_failed:
|
||||
}
|
||||
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];
|
||||
|
|
@ -455,114 +367,85 @@ dtoa(double d0, int mode, int ndigits, int *decpt, int *sign, char **rve)
|
|||
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++ = '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 retc;
|
||||
case 2: goto bump_up;
|
||||
}
|
||||
#endif
|
||||
switch(Rounding) {
|
||||
case 0: goto retc;
|
||||
case 2: goto bump_up;
|
||||
}
|
||||
dval(&d) += dval(&d);
|
||||
#ifdef ROUND_BIASED
|
||||
if (dval(&d) >= ds)
|
||||
#else
|
||||
if (dval(&d) > ds || (dval(&d) == ds && L & 1))
|
||||
#endif
|
||||
{
|
||||
bump_up:
|
||||
if (dval(&d) > ds || (dval(&d) == ds && L & 1)) {
|
||||
bump_up:
|
||||
while(*--s == '9')
|
||||
if (s == s0) {
|
||||
k++;
|
||||
*s = '0';
|
||||
break;
|
||||
}
|
||||
}
|
||||
++*s++;
|
||||
}
|
||||
break;
|
||||
}
|
||||
break;
|
||||
}
|
||||
goto retc;
|
||||
}
|
||||
|
||||
goto retc;
|
||||
}
|
||||
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
|
||||
i = denorm ? be + (Bias + (P-1) - 1 + 1) : 1 + P - bbits;
|
||||
b2 += i;
|
||||
s2 += i;
|
||||
mhi = i2b(1 MTb);
|
||||
}
|
||||
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 MTb);
|
||||
b1 = mult(mhi, b MTb);
|
||||
Bfree(b MTb);
|
||||
mhi = pow5mult(mhi, m5);
|
||||
b1 = mult(mhi, b);
|
||||
Bfree(b);
|
||||
b = b1;
|
||||
}
|
||||
if (( j = b5 - m5 )!=0)
|
||||
b = pow5mult(b, j MTb);
|
||||
}
|
||||
else
|
||||
b = pow5mult(b, b5 MTb);
|
||||
if (( j = b5 - m5 )!=0)
|
||||
b = pow5mult(b, j);
|
||||
}
|
||||
S = i2b(1 MTb);
|
||||
else
|
||||
b = pow5mult(b, b5);
|
||||
}
|
||||
S = i2b(1);
|
||||
if (s5 > 0)
|
||||
S = pow5mult(S, s5 MTb);
|
||||
S = pow5mult(S, s5);
|
||||
|
||||
/* 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
|
||||
) {
|
||||
if ((mode < 2 || leftright) && Rounding == 1) {
|
||||
if (!word1(&d) && !(word0(&d) & Bndry_mask) &&
|
||||
word0(&d) & (Exp_mask & ~Exp_msk1)) {
|
||||
/* 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.
|
||||
|
|
@ -571,225 +454,169 @@ dtoa(double d0, int mode, int ndigits, int *decpt, int *sign, char **rve)
|
|||
* 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 MTb);
|
||||
b = lshift(b, b2);
|
||||
if (s2 > 0)
|
||||
S = lshift(S, s2 MTb);
|
||||
S = lshift(S, s2);
|
||||
if (k_check) {
|
||||
if (cmp(b,S) < 0) {
|
||||
k--;
|
||||
b = multadd(b, 10, 0 MTb); /* we botched the k estimate */
|
||||
b = multadd(b, 10, 0); /* we botched the k estimate */
|
||||
if (leftright)
|
||||
mhi = multadd(mhi, 10, 0 MTb);
|
||||
mhi = multadd(mhi, 10, 0);
|
||||
ilim = ilim1;
|
||||
}
|
||||
}
|
||||
}
|
||||
if (ilim <= 0 && (mode == 3 || mode == 5)) {
|
||||
if (ilim < 0 || cmp(b,S = multadd(S,5,0 MTb)) <= 0) {
|
||||
if (ilim < 0 || cmp(b,S = multadd(S,5,0)) <= 0) {
|
||||
/* no digits, fcvt style */
|
||||
no_digits:
|
||||
no_digits:
|
||||
k = -1 - ndigits;
|
||||
goto ret;
|
||||
}
|
||||
one_digit:
|
||||
}
|
||||
one_digit:
|
||||
*s++ = '1';
|
||||
k++;
|
||||
goto ret;
|
||||
}
|
||||
}
|
||||
if (leftright) {
|
||||
if (m2 > 0)
|
||||
mhi = lshift(mhi, m2 MTb);
|
||||
|
||||
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 MTb);
|
||||
mhi = Balloc(mhi->k);
|
||||
Bcopy(mhi, mlo);
|
||||
mhi = lshift(mhi, Log2P MTb);
|
||||
}
|
||||
|
||||
mhi = lshift(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(S, mhi MTb);
|
||||
delta = diff(S, mhi);
|
||||
j1 = delta->sign ? 1 : cmp(b, delta);
|
||||
Bfree(delta MTb);
|
||||
#ifndef ROUND_BIASED
|
||||
if (j1 == 0 && mode != 1 && !(word1(&d) & 1)
|
||||
#ifdef Honor_FLT_ROUNDS
|
||||
&& Rounding >= 1
|
||||
#endif
|
||||
) {
|
||||
Bfree(delta);
|
||||
if (j1 == 0 && mode != 1 && !(word1(&d) & 1) && Rounding >= 1) {
|
||||
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++ = dig;
|
||||
goto ret;
|
||||
}
|
||||
#endif
|
||||
if (j < 0 || (j == 0 && mode != 1
|
||||
#ifndef ROUND_BIASED
|
||||
&& !(word1(&d) & 1)
|
||||
#endif
|
||||
)) {
|
||||
}
|
||||
if (j < 0 || (j == 0 && mode != 1 && !(word1(&d) & 1)
|
||||
)) {
|
||||
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 (j1 > 0) {
|
||||
b = lshift(b, 1 MTb);
|
||||
j1 = cmp(b, S);
|
||||
#ifdef ROUND_BIASED
|
||||
if (j1 >= 0 /*)*/
|
||||
#else
|
||||
if ((j1 > 0 || (j1 == 0 && dig & 1))
|
||||
#endif
|
||||
&& dig++ == '9')
|
||||
goto round_9_up;
|
||||
switch(Rounding) {
|
||||
case 0: goto accept_dig;
|
||||
case 2: goto keep_dig;
|
||||
}
|
||||
accept_dig:
|
||||
if (j1 > 0) {
|
||||
b = lshift(b, 1);
|
||||
j1 = cmp(b, S);
|
||||
if ((j1 > 0 || (j1 == 0 && dig & 1))
|
||||
&& dig++ == '9')
|
||||
goto round_9_up;
|
||||
}
|
||||
accept_dig:
|
||||
*s++ = dig;
|
||||
goto ret;
|
||||
}
|
||||
}
|
||||
if (j1 > 0) {
|
||||
#ifdef Honor_FLT_ROUNDS
|
||||
if (!Rounding && mode > 1)
|
||||
goto accept_dig;
|
||||
#endif
|
||||
if (dig == '9') { /* possible if i == 1 */
|
||||
round_9_up:
|
||||
round_9_up:
|
||||
*s++ = '9';
|
||||
goto roundoff;
|
||||
}
|
||||
}
|
||||
*s++ = dig + 1;
|
||||
goto ret;
|
||||
}
|
||||
#ifdef Honor_FLT_ROUNDS
|
||||
keep_dig:
|
||||
#endif
|
||||
}
|
||||
keep_dig:
|
||||
*s++ = dig;
|
||||
if (i == ilim)
|
||||
break;
|
||||
b = multadd(b, 10, 0 MTb);
|
||||
b = multadd(b, 10, 0);
|
||||
if (mlo == mhi)
|
||||
mlo = mhi = multadd(mhi, 10, 0 MTb);
|
||||
mlo = mhi = multadd(mhi, 10, 0);
|
||||
else {
|
||||
mlo = multadd(mlo, 10, 0 MTb);
|
||||
mhi = multadd(mhi, 10, 0 MTb);
|
||||
}
|
||||
mlo = multadd(mlo, 10, 0);
|
||||
mhi = multadd(mhi, 10, 0);
|
||||
}
|
||||
}
|
||||
else
|
||||
}
|
||||
else {
|
||||
for(i = 1;; i++) {
|
||||
*s++ = dig = 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 MTb);
|
||||
}
|
||||
b = multadd(b, 10, 0);
|
||||
}
|
||||
}
|
||||
|
||||
/* Round off last digit */
|
||||
|
||||
#ifdef Honor_FLT_ROUNDS
|
||||
switch(Rounding) {
|
||||
case 0: goto trimzeros;
|
||||
case 2: goto roundoff;
|
||||
}
|
||||
#endif
|
||||
b = lshift(b, 1 MTb);
|
||||
case 0: goto trimzeros;
|
||||
case 2: goto roundoff;
|
||||
}
|
||||
b = lshift(b, 1);
|
||||
j = cmp(b, S);
|
||||
#ifdef ROUND_BIASED
|
||||
if (j >= 0)
|
||||
#else
|
||||
if (j > 0 || (j == 0 && dig & 1))
|
||||
#endif
|
||||
{
|
||||
roundoff:
|
||||
{
|
||||
roundoff:
|
||||
while(*--s == '9')
|
||||
if (s == s0) {
|
||||
k++;
|
||||
*s++ = '1';
|
||||
goto ret;
|
||||
}
|
||||
}
|
||||
++*s++;
|
||||
}
|
||||
}
|
||||
else {
|
||||
#ifdef Honor_FLT_ROUNDS
|
||||
trimzeros:
|
||||
#endif
|
||||
trimzeros:
|
||||
while(*--s == '0');
|
||||
s++;
|
||||
}
|
||||
ret:
|
||||
Bfree(S MTb);
|
||||
}
|
||||
ret:
|
||||
Bfree(S);
|
||||
if (mhi) {
|
||||
if (mlo && mlo != mhi)
|
||||
Bfree(mlo MTb);
|
||||
Bfree(mhi MTb);
|
||||
}
|
||||
retc:
|
||||
Bfree(mlo);
|
||||
Bfree(mhi);
|
||||
}
|
||||
retc:
|
||||
while(s > s0 && s[-1] == '0')
|
||||
--s;
|
||||
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 MTb);
|
||||
ret1:
|
||||
Bfree(b);
|
||||
*s = 0;
|
||||
*decpt = k + 1;
|
||||
if (rve)
|
||||
*rve = s;
|
||||
return s0;
|
||||
}
|
||||
}
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue