[mirror_edk2.git] / StdLib / LibC / gdtoa / strtodg.c

/** @file\r
\r
  Copyright (c) 2012 - 2014, Intel Corporation. All rights reserved.<BR>\r
  This program and the accompanying materials are licensed and made available under\r
  the terms and conditions of the BSD License that accompanies this distribution.\r
  The full text of the license may be found at\r
  http://opensource.org/licenses/bsd-license.\r
\r
  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
\r
  *****************************************************************\r
\r
  The author of this software is David M. Gay.\r
\r
  Copyright (C) 1998-2001 by Lucent Technologies\r
  All Rights Reserved\r
\r
  Permission to use, copy, modify, and distribute this software and\r
  its documentation for any purpose and without fee is hereby\r
  granted, provided that the above copyright notice appear in all\r
  copies and that both that the copyright notice and this\r
  permission notice and warranty disclaimer appear in supporting\r
  documentation, and that the name of Lucent or any of its entities\r
  not be used in advertising or publicity pertaining to\r
  distribution of the software without specific, written prior\r
  permission.\r
\r
  LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,\r
  INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.\r
  IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY\r
  SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES\r
  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER\r
  IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,\r
  ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF\r
  THIS SOFTWARE.\r
\r
  Please send bug reports to David M. Gay (dmg at acm dot org,\r
  with " at " changed at "@" and " dot " changed to ".").\r
\r
  *****************************************************************\r
\r
  NetBSD: strtodg.c,v 1.5.14.1 2008/04/08 21:10:55 jdc Exp\r
**/\r
#include  <LibConfig.h>\r
\r
#include "gdtoaimp.h"\r
\r
#ifdef USE_LOCALE\r
#include "locale.h"\r
#endif\r
\r
#if defined(_MSC_VER)\r
  // Disable warnings about assignment within conditional expressions.\r
  #pragma warning ( disable : 4706 )\r
#endif\r
\r
 static CONST int\r
fivesbits[] = {  0,  3,  5,  7, 10, 12, 14, 17, 19, 21,\r
    24, 26, 28, 31, 33, 35, 38, 40, 42, 45,\r
    47, 49, 52\r
#ifdef VAX\r
    , 54, 56\r
#endif\r
    };\r
\r
 Bigint *\r
increment(Bigint *b)\r
{\r
  ULong *x, *xe;\r
  Bigint *b1;\r
#ifdef Pack_16\r
  ULong carry = 1, y;\r
#endif\r
\r
  x = b->x;\r
  xe = x + b->wds;\r
#ifdef Pack_32\r
  do {\r
    if (*x < (ULong)0xffffffffL) {\r
      ++*x;\r
      return b;\r
      }\r
    *x++ = 0;\r
    } while(x < xe);\r
#else\r
  do {\r
    y = *x + carry;\r
    carry = y >> 16;\r
    *x++ = y & 0xffff;\r
    if (!carry)\r
      return b;\r
    } while(x < xe);\r
  if (carry)\r
#endif\r
  {\r
    if (b->wds >= b->maxwds) {\r
      b1 = Balloc(b->k+1);\r
      if (b1 == NULL)\r
        return NULL;\r
      Bcopy(b1,b);\r
      Bfree(b);\r
      b = b1;\r
      }\r
    b->x[b->wds++] = 1;\r
    }\r
  return b;\r
  }\r
\r
 int\r
decrement(Bigint *b)\r
{\r
  ULong *x, *xe;\r
#ifdef Pack_16\r
  ULong borrow = 1, y;\r
#endif\r
\r
  x = b->x;\r
  xe = x + b->wds;\r
#ifdef Pack_32\r
  do {\r
    if (*x) {\r
      --*x;\r
      break;\r
      }\r
    *x++ = 0xffffffffUL;\r
    }\r
    while(x < xe);\r
#else\r
  do {\r
    y = *x - borrow;\r
    borrow = (y & 0x10000) >> 16;\r
    *x++ = y & 0xffff;\r
    } while(borrow && x < xe);\r
#endif\r
  return STRTOG_Inexlo;\r
  }\r
\r
 static int\r
all_on(CONST Bigint *b, int n)\r
{\r
  CONST ULong *x, *xe;\r
\r
  x = b->x;\r
  xe = x + ((unsigned int)n >> kshift);\r
  while(x < xe)\r
    if ((*x++ & ALL_ON) != ALL_ON)\r
      return 0;\r
  if (n &= kmask)\r
    return ((*x | (ALL_ON << n)) & ALL_ON) == ALL_ON;\r
  return 1;\r
  }\r
\r
 Bigint *\r
set_ones(Bigint *b, int n)\r
{\r
  int k;\r
  ULong *x, *xe;\r
\r
  k = (unsigned int)(n + ((1 << kshift) - 1)) >> kshift;\r
  if (b->k < k) {\r
    Bfree(b);\r
    b = Balloc(k);\r
    if (b == NULL)\r
      return NULL;\r
    }\r
  k = (unsigned int)n >> kshift;\r
  if (n &= kmask)\r
    k++;\r
  b->wds = k;\r
  x = b->x;\r
  xe = x + k;\r
  while(x < xe)\r
    *x++ = ALL_ON;\r
  if (n)\r
    x[-1] >>= ULbits - n;\r
  return b;\r
  }\r
\r
 static int\r
rvOK (\r
  double d, CONST FPI *fpi, Long *expt, ULong *bits, int exact, int rd, int *irv\r
)\r
{\r
  Bigint *b;\r
  ULong carry, inex, lostbits;\r
  int bdif, e, j, k, k1, nb, rv;\r
\r
  carry = rv = 0;\r
  b = d2b(d, &e, &bdif);\r
  bdif -= nb = fpi->nbits;\r
  e += bdif;\r
  if (bdif <= 0) {\r
    if (exact)\r
      goto trunc;\r
    goto ret;\r
    }\r
  if (P == nb) {\r
    if (\r
#ifndef IMPRECISE_INEXACT\r
      exact &&\r
#endif\r
      fpi->rounding ==\r
#ifdef RND_PRODQUOT\r
          FPI_Round_near\r
#else\r
          Flt_Rounds\r
#endif\r
      ) goto trunc;\r
    goto ret;\r
    }\r
  switch(rd) {\r
    case 1:\r
    goto trunc;\r
    case 2:\r
    break;\r
    default: /* round near */\r
    k = bdif - 1;\r
    if (!k) {\r
      if (!exact)\r
        goto ret;\r
      if (b->x[0] & 2)\r
        break;\r
      goto trunc;\r
      }\r
    if (b->x[(unsigned int)k>>kshift] & ((ULong)1 << (k & kmask)))\r
      break;\r
    goto trunc;\r
    }\r
  /* "break" cases: round up 1 bit, then truncate; bdif > 0 */\r
  carry = 1;\r
 trunc:\r
  inex = lostbits = 0;\r
  if (bdif > 0) {\r
    if ( (lostbits = any_on(b, bdif)) !=0)\r
      inex = STRTOG_Inexlo;\r
    rshift(b, bdif);\r
    if (carry) {\r
      inex = STRTOG_Inexhi;\r
      b = increment(b);\r
      if ( (j = nb & kmask) !=0)\r
        j = ULbits - j;\r
      if (hi0bits(b->x[b->wds - 1]) != j) {\r
        if (!lostbits)\r
          lostbits = b->x[0] & 1;\r
        rshift(b, 1);\r
        e++;\r
        }\r
      }\r
    }\r
  else if (bdif < 0)\r
    b = lshift(b, -bdif);\r
  if (e < fpi->emin) {\r
    k = fpi->emin - e;\r
    e = fpi->emin;\r
    if (k > nb || fpi->sudden_underflow) {\r
      inex = b->wds = 0;\r
      *irv = STRTOG_Underflow | STRTOG_Inexlo;\r
      }\r
    else {\r
      k1 = k - 1;\r
      if (k1 > 0 && !lostbits)\r
        lostbits = any_on(b, k1);\r
      if (!lostbits && !exact)\r
        goto ret;\r
      lostbits |=\r
        carry = b->x[(unsigned int)k1>>kshift] &\r
                     (ULong)(1 << ((unsigned int)k1 & kmask));\r
      rshift(b, k);\r
      *irv = STRTOG_Denormal;\r
      if (carry) {\r
        b = increment(b);\r
        inex = STRTOG_Inexhi | STRTOG_Underflow;\r
        }\r
      else if (lostbits)\r
        inex = STRTOG_Inexlo | STRTOG_Underflow;\r
      }\r
    }\r
  else if (e > fpi->emax) {\r
    e = fpi->emax + 1;\r
    *irv = STRTOG_Infinite | STRTOG_Overflow | STRTOG_Inexhi;\r
#ifndef NO_ERRNO\r
    errno = ERANGE;\r
#endif\r
    inex = b->wds = 0;\r
    }\r
  *expt = e;\r
  copybits(bits, nb, b);\r
  *irv |= inex;\r
  rv = 1;\r
 ret:\r
  Bfree(b);\r
  return rv;\r
  }\r
\r
 static int\r
mantbits(double d)\r
{\r
  ULong L;\r
  if ( (L = word1(d)) !=0)\r
    return P - lo0bits(&L);\r
  L = word0(d) | Exp_msk1;\r
  return P - 32 - lo0bits(&L);\r
  }\r
\r
 int\r
strtodg (\r
  CONST char *s00, char **se, CONST FPI *fpi, Long *expt, ULong *bits\r
)\r
{\r
  int abe = 0, abits = 0, asub;\r
  int bb0, bb2, bb5, bbe, bd2, bd5, bbbits, bs2, c, decpt, denorm;\r
  int dsign, e, e1, e2, emin, esign, finished, i, inex, irv;\r
  int j, k, nbits, nd, nd0, nf, nz, nz0, rd, rvbits, rve, rve1, sign;\r
  int sudden_underflow = 0; /* pacify gcc */\r
  CONST char *s, *s0, *s1;\r
  double adj, adj0, rv, tol;\r
  Long L;\r
  ULong y, z;\r
  Bigint *ab, *bb, *bb1, *bd, *bd0, *bs, *delta, *rvb, *rvb0;\r
\r
  e2 = 0; /* XXX gcc */\r
\r
  irv = STRTOG_Zero;\r
  denorm = sign = nz0 = nz = 0;\r
  dval(rv) = 0.;\r
  rvb = 0;\r
  nbits = fpi->nbits;\r
  for(s = s00;;s++) switch(*s) {\r
    case '-':\r
      sign = 1;\r
      /* FALLTHROUGH */\r
    case '+':\r
      if (*++s)\r
        goto break2;\r
      /* FALLTHROUGH */\r
    case 0:\r
      sign = 0;\r
      irv = STRTOG_NoNumber;\r
      s = s00;\r
      goto ret;\r
    case '\t':\r
    case '\n':\r
    case '\v':\r
    case '\f':\r
    case '\r':\r
    case ' ':\r
      continue;\r
    default:\r
      goto break2;\r
    }\r
 break2:\r
  if (*s == '0') {\r
#ifndef NO_HEX_FP\r
    switch(s[1]) {\r
      case 'x':\r
      case 'X':\r
      irv = gethex(&s, fpi, expt, &rvb, sign);\r
      if (irv == STRTOG_NoNumber) {\r
        s = s00;\r
        sign = 0;\r
        }\r
      goto ret;\r
      }\r
#endif\r
    nz0 = 1;\r
    while(*++s == '0') ;\r
    if (!*s)\r
      goto ret;\r
    }\r
  sudden_underflow = fpi->sudden_underflow;\r
  s0 = s;\r
  y = z = 0;\r
  for(decpt = nd = nf = 0; (c = *s) >= '0' && c <= '9'; nd++, s++)\r
    if (nd < 9)\r
      y = 10*y + c - '0';\r
    else if (nd < 16)\r
      z = 10*z + c - '0';\r
  nd0 = nd;\r
#ifdef USE_LOCALE\r
  if (c == *localeconv()->decimal_point)\r
#else\r
  if (c == '.')\r
#endif\r
    {\r
    decpt = 1;\r
    c = *++s;\r
    if (!nd) {\r
      for(; c == '0'; c = *++s)\r
        nz++;\r
      if (c > '0' && c <= '9') {\r
        s0 = s;\r
        nf += nz;\r
        nz = 0;\r
        goto have_dig;\r
        }\r
      goto dig_done;\r
      }\r
    for(; c >= '0' && c <= '9'; c = *++s) {\r
 have_dig:\r
      nz++;\r
      if (c -= '0') {\r
        nf += nz;\r
        for(i = 1; i < nz; i++)\r
          if (nd++ < 9)\r
            y *= 10;\r
          else if (nd <= DBL_DIG + 1)\r
            z *= 10;\r
        if (nd++ < 9)\r
          y = 10*y + c;\r
        else if (nd <= DBL_DIG + 1)\r
          z = 10*z + c;\r
        nz = 0;\r
        }\r
      }\r
    }\r
 dig_done:\r
  e = 0;\r
  if (c == 'e' || c == 'E') {\r
    if (!nd && !nz && !nz0) {\r
      irv = STRTOG_NoNumber;\r
      s = s00;\r
      goto ret;\r
      }\r
    s00 = s;\r
    esign = 0;\r
    switch(c = *++s) {\r
      case '-':\r
        esign = 1;\r
        /* FALLTHROUGH */\r
      case '+':\r
        c = *++s;\r
      }\r
    if (c >= '0' && c <= '9') {\r
      while(c == '0')\r
        c = *++s;\r
      if (c > '0' && c <= '9') {\r
        L = c - '0';\r
        s1 = s;\r
        while((c = *++s) >= '0' && c <= '9')\r
          L = 10*L + c - '0';\r
        if (s - s1 > 8 || L > 19999)\r
          /* Avoid confusion from exponents\r
           * so large that e might overflow.\r
           */\r
          e = 19999; /* safe for 16 bit ints */\r
        else\r
          e = (int)L;\r
        if (esign)\r
          e = -e;\r
        }\r
      else\r
        e = 0;\r
      }\r
    else\r
      s = s00;\r
    }\r
  if (!nd) {\r
    if (!nz && !nz0) {\r
#ifdef INFNAN_CHECK\r
      /* Check for Nan and Infinity */\r
      if (!decpt)\r
       switch(c) {\r
        case 'i':\r
        case 'I':\r
        if (match(&s,"nf")) {\r
          --s;\r
          if (!match(&s,"inity"))\r
            ++s;\r
          irv = STRTOG_Infinite;\r
          goto infnanexp;\r
          }\r
        break;\r
        case 'n':\r
        case 'N':\r
        if (match(&s, "an")) {\r
          irv = STRTOG_NaN;\r
          *expt = fpi->emax + 1;\r
#ifndef No_Hex_NaN\r
          if (*s == '(') /*)*/\r
            irv = hexnan(&s, fpi, bits);\r
#endif\r
          goto infnanexp;\r
          }\r
        }\r
#endif /* INFNAN_CHECK */\r
      irv = STRTOG_NoNumber;\r
      s = s00;\r
      }\r
    goto ret;\r
    }\r
\r
  irv = STRTOG_Normal;\r
  e1 = e -= nf;\r
  rd = 0;\r
  switch(fpi->rounding & 3) {\r
    case FPI_Round_up:\r
    rd = 2 - sign;\r
    break;\r
    case FPI_Round_zero:\r
    rd = 1;\r
    break;\r
    case FPI_Round_down:\r
    rd = 1 + sign;\r
    }\r
\r
  /* Now we have nd0 digits, starting at s0, followed by a\r
   * decimal point, followed by nd-nd0 digits.  The number we're\r
   * after is the integer represented by those digits times\r
   * 10**e */\r
\r
  if (!nd0)\r
    nd0 = nd;\r
  k = nd < DBL_DIG + 1 ? nd : DBL_DIG + 1;\r
  dval(rv) = (double)y;\r
  if (k > 9)\r
    dval(rv) = tens[k - 9] * dval(rv) + z;\r
  bd0 = 0;\r
  if (nbits <= P && nd <= DBL_DIG) {\r
    if (!e) {\r
      if (rvOK(dval(rv), fpi, expt, bits, 1, rd, &irv))\r
        goto ret;\r
      }\r
    else if (e > 0) {\r
      if (e <= Ten_pmax) {\r
        i = fivesbits[e] + mantbits(dval(rv)) <= P;\r
        /* rv = */ rounded_product(dval(rv), tens[e]);\r
        if (rvOK(dval(rv), fpi, expt, bits, i, rd, &irv))\r
          goto ret;\r
        e1 -= e;\r
        goto rv_notOK;\r
        }\r
      i = DBL_DIG - nd;\r
      if (e <= Ten_pmax + i) {\r
        /* A fancier test would sometimes let us do\r
         * this for larger i values.\r
         */\r
        e2 = e - i;\r
        e1 -= i;\r
        dval(rv) *= tens[i];\r
        /* rv = */ rounded_product(dval(rv), tens[e2]);\r
        if (rvOK(dval(rv), fpi, expt, bits, 0, rd, &irv))\r
          goto ret;\r
        e1 -= e2;\r
        }\r
      }\r
#ifndef Inaccurate_Divide\r
    else if (e >= -Ten_pmax) {\r
      /* rv = */ rounded_quotient(dval(rv), tens[-e]);\r
      if (rvOK(dval(rv), fpi, expt, bits, 0, rd, &irv))\r
        goto ret;\r
      e1 -= e;\r
      }\r
#endif\r
    }\r
 rv_notOK:\r
  e1 += nd - k;\r
\r
  /* Get starting approximation = rv * 10**e1 */\r
\r
  e2 = 0;\r
  if (e1 > 0) {\r
    if ( (i = e1 & 15) !=0)\r
      dval(rv) *= tens[i];\r
    if (e1 &= ~15) {\r
      e1 = (unsigned int)e1 >> 4;\r
      while(e1 >= (1 << (n_bigtens-1))) {\r
        e2 += (unsigned int)((word0(rv) & Exp_mask)\r
          >> Exp_shift1) - Bias;\r
        word0(rv) &= ~Exp_mask;\r
        word0(rv) |= Bias << Exp_shift1;\r
        dval(rv) *= bigtens[n_bigtens-1];\r
        e1 -= 1 << (n_bigtens-1);\r
        }\r
      e2 += (unsigned int)((word0(rv) & Exp_mask) >> Exp_shift1) - Bias;\r
      word0(rv) &= ~Exp_mask;\r
      word0(rv) |= Bias << Exp_shift1;\r
      for(j = 0; e1 > 0; j++, e1 = (unsigned int)e1 >> 1)\r
        if (e1 & 1)\r
          dval(rv) *= bigtens[j];\r
      }\r
    }\r
  else if (e1 < 0) {\r
    e1 = -e1;\r
    if ( (i = e1 & 15) !=0)\r
      dval(rv) /= tens[i];\r
    if (e1 &= ~15) {\r
      e1 = (unsigned int)e1 >> 4;\r
      while(e1 >= (1 << (n_bigtens-1))) {\r
        e2 += (unsigned int)((word0(rv) & Exp_mask)\r
          >> Exp_shift1) - Bias;\r
        word0(rv) &= ~Exp_mask;\r
        word0(rv) |= Bias << Exp_shift1;\r
        dval(rv) *= tinytens[n_bigtens-1];\r
        e1 -= 1 << (n_bigtens-1);\r
        }\r
      e2 += (unsigned int)((word0(rv) & Exp_mask) >> Exp_shift1) - Bias;\r
      word0(rv) &= ~Exp_mask;\r
      word0(rv) |= Bias << Exp_shift1;\r
      for(j = 0; e1 > 0; j++, e1 = (unsigned int)e1 >> 1)\r
        if (e1 & 1)\r
          dval(rv) *= tinytens[j];\r
      }\r
    }\r
  rvb = d2b(dval(rv), &rve, &rvbits); /* rv = rvb * 2^rve */\r
  if (rvb == NULL)\r
    return STRTOG_NoMemory;\r
  rve += e2;\r
  if ((j = rvbits - nbits) > 0) {\r
    rshift(rvb, j);\r
    rvbits = nbits;\r
    rve += j;\r
    }\r
  bb0 = 0;  /* trailing zero bits in rvb */\r
  e2 = rve + rvbits - nbits;\r
  if (e2 > fpi->emax + 1)\r
    goto huge;\r
  rve1 = rve + rvbits - nbits;\r
  if (e2 < (emin = fpi->emin)) {\r
    denorm = 1;\r
    j = rve - emin;\r
    if (j > 0) {\r
      rvb = lshift(rvb, j);\r
      rvbits += j;\r
      }\r
    else if (j < 0) {\r
      rvbits += j;\r
      if (rvbits <= 0) {\r
        if (rvbits < -1) {\r
 ufl:\r
          rvb->wds = 0;\r
          rvb->x[0] = 0;\r
          *expt = emin;\r
          irv = STRTOG_Underflow | STRTOG_Inexlo;\r
          goto ret;\r
          }\r
        rvb->x[0] = rvb->wds = rvbits = 1;\r
        }\r
      else\r
        rshift(rvb, -j);\r
      }\r
    rve = rve1 = emin;\r
    if (sudden_underflow && e2 + 1 < emin)\r
      goto ufl;\r
    }\r
\r
  /* Now the hard part -- adjusting rv to the correct value.*/\r
\r
  /* Put digits into bd: true value = bd * 10^e */\r
\r
  bd0 = s2b(s0, nd0, nd, y);\r
\r
  for(;;) {\r
    bd = Balloc(bd0->k);\r
    if (bd == NULL)\r
      return STRTOG_NoMemory;\r
    Bcopy(bd, bd0);\r
    bb = Balloc(rvb->k);\r
    if (bb == NULL)\r
      return STRTOG_NoMemory;\r
    Bcopy(bb, rvb);\r
    bbbits = rvbits - bb0;\r
    bbe = rve + bb0;\r
    bs = i2b(1);\r
    if (bs == NULL)\r
      return STRTOG_NoMemory;\r
\r
    if (e >= 0) {\r
      bb2 = bb5 = 0;\r
      bd2 = bd5 = e;\r
      }\r
    else {\r
      bb2 = bb5 = -e;\r
      bd2 = bd5 = 0;\r
      }\r
    if (bbe >= 0)\r
      bb2 += bbe;\r
    else\r
      bd2 -= bbe;\r
    bs2 = bb2;\r
    j = nbits + 1 - bbbits;\r
    i = bbe + bbbits - nbits;\r
    if (i < emin) /* denormal */\r
      j += i - emin;\r
    bb2 += j;\r
    bd2 += j;\r
    i = bb2 < bd2 ? bb2 : bd2;\r
    if (i > bs2)\r
      i = bs2;\r
    if (i > 0) {\r
      bb2 -= i;\r
      bd2 -= i;\r
      bs2 -= i;\r
      }\r
    if (bb5 > 0) {\r
      bs = pow5mult(bs, bb5);\r
      if (bs == NULL)\r
        return STRTOG_NoMemory;\r
      bb1 = mult(bs, bb);\r
      if (bb1 == NULL)\r
        return STRTOG_NoMemory;\r
      Bfree(bb);\r
      bb = bb1;\r
      }\r
    bb2 -= bb0;\r
    if (bb2 > 0) {\r
      bb = lshift(bb, bb2);\r
      if (bb == NULL)\r
        return STRTOG_NoMemory;\r
      }\r
    else if (bb2 < 0)\r
      rshift(bb, -bb2);\r
    if (bd5 > 0) {\r
      bd = pow5mult(bd, bd5);\r
      if (bd == NULL)\r
        return STRTOG_NoMemory;\r
      }\r
    if (bd2 > 0) {\r
      bd = lshift(bd, bd2);\r
      if (bd == NULL)\r
        return STRTOG_NoMemory;\r
      }\r
    if (bs2 > 0) {\r
      bs = lshift(bs, bs2);\r
      if (bs == NULL)\r
        return STRTOG_NoMemory;\r
      }\r
    asub = 1;\r
    inex = STRTOG_Inexhi;\r
    delta = diff(bb, bd);\r
    if (delta == NULL)\r
      return STRTOG_NoMemory;\r
    if (delta->wds <= 1 && !delta->x[0])\r
      break;\r
    dsign = delta->sign;\r
    delta->sign = finished = 0;\r
    L = 0;\r
    i = cmp(delta, bs);\r
    if (rd && i <= 0) {\r
      irv = STRTOG_Normal;\r
      if ( (finished = dsign ^ (rd&1)) !=0) {\r
        if (dsign != 0) {\r
          irv |= STRTOG_Inexhi;\r
          goto adj1;\r
          }\r
        irv |= STRTOG_Inexlo;\r
        if (rve1 == emin)\r
          goto adj1;\r
        for(i = 0, j = nbits; j >= ULbits;\r
            i++, j -= ULbits) {\r
          if (rvb->x[i] & ALL_ON)\r
            goto adj1;\r
          }\r
        if (j > 1 && lo0bits(rvb->x + i) < j - 1)\r
          goto adj1;\r
        rve = rve1 - 1;\r
        rvb = set_ones(rvb, rvbits = nbits);\r
        if (rvb == NULL)\r
          return STRTOG_NoMemory;\r
        break;\r
        }\r
      irv |= dsign ? STRTOG_Inexlo : STRTOG_Inexhi;\r
      break;\r
      }\r
    if (i < 0) {\r
      /* Error is less than half an ulp -- check for\r
       * special case of mantissa a power of two.\r
       */\r
      irv = dsign\r
        ? STRTOG_Normal | STRTOG_Inexlo\r
        : STRTOG_Normal | STRTOG_Inexhi;\r
      if (dsign || bbbits > 1 || denorm || rve1 == emin)\r
        break;\r
      delta = lshift(delta,1);\r
      if (delta == NULL)\r
        return STRTOG_NoMemory;\r
      if (cmp(delta, bs) > 0) {\r
        irv = STRTOG_Normal | STRTOG_Inexlo;\r
        goto drop_down;\r
        }\r
      break;\r
      }\r
    if (i == 0) {\r
      /* exactly half-way between */\r
      if (dsign) {\r
        if (denorm && all_on(rvb, rvbits)) {\r
          /*boundary case -- increment exponent*/\r
          rvb->wds = 1;\r
          rvb->x[0] = 1;\r
          rve = emin + nbits - (rvbits = 1);\r
          irv = STRTOG_Normal | STRTOG_Inexhi;\r
          denorm = 0;\r
          break;\r
          }\r
        irv = STRTOG_Normal | STRTOG_Inexlo;\r
        }\r
      else if (bbbits == 1) {\r
        irv = STRTOG_Normal;\r
 drop_down:\r
        /* boundary case -- decrement exponent */\r
        if (rve1 == emin) {\r
          irv = STRTOG_Normal | STRTOG_Inexhi;\r
          if (rvb->wds == 1 && rvb->x[0] == 1)\r
            sudden_underflow = 1;\r
          break;\r
          }\r
        rve -= nbits;\r
        rvb = set_ones(rvb, rvbits = nbits);\r
        if (rvb == NULL)\r
          return STRTOG_NoMemory;\r
        break;\r
        }\r
      else\r
        irv = STRTOG_Normal | STRTOG_Inexhi;\r
      if ((bbbits < nbits && !denorm) || !(rvb->x[0] & 1))\r
        break;\r
      if (dsign) {\r
        rvb = increment(rvb);\r
        if (rvb == NULL)\r
          return STRTOG_NoMemory;\r
        if ( (j = rvbits & kmask) !=0)\r
          j = ULbits - j;\r
        if (hi0bits(rvb->x[(unsigned int)(rvb->wds - 1)\r
               >> kshift])\r
            != j)\r
          rvbits++;\r
        irv = STRTOG_Normal | STRTOG_Inexhi;\r
        }\r
      else {\r
        if (bbbits == 1)\r
          goto undfl;\r
        decrement(rvb);\r
        irv = STRTOG_Normal | STRTOG_Inexlo;\r
        }\r
      break;\r
      }\r
    if ((dval(adj) = ratio(delta, bs)) <= 2.) {\r
 adj1:\r
      inex = STRTOG_Inexlo;\r
      if (dsign) {\r
        asub = 0;\r
        inex = STRTOG_Inexhi;\r
        }\r
      else if (denorm && bbbits <= 1) {\r
 undfl:\r
        rvb->wds = 0;\r
        rve = emin;\r
        irv = STRTOG_Underflow | STRTOG_Inexlo;\r
        break;\r
        }\r
      adj0 = dval(adj) = 1.;\r
      }\r
    else {\r
      adj0 = dval(adj) *= 0.5;\r
      if (dsign) {\r
        asub = 0;\r
        inex = STRTOG_Inexlo;\r
        }\r
      if (dval(adj) < 2147483647.) {\r
        L = (Long)adj0;\r
        adj0 -= L;\r
        switch(rd) {\r
          case 0:\r
          if (adj0 >= .5)\r
            goto inc_L;\r
          break;\r
          case 1:\r
          if (asub && adj0 > 0.)\r
            goto inc_L;\r
          break;\r
          case 2:\r
          if (!asub && adj0 > 0.) {\r
inc_L:\r
            L++;\r
            inex = STRTOG_Inexact - inex;\r
            }\r
          }\r
        dval(adj) = (double)L;\r
        }\r
      }\r
    y = rve + rvbits;\r
\r
    /* adj *= ulp(dval(rv)); */\r
    /* if (asub) rv -= adj; else rv += adj; */\r
\r
    if (!denorm && rvbits < nbits) {\r
      rvb = lshift(rvb, j = nbits - rvbits);\r
      if (rvb == NULL)\r
        return STRTOG_NoMemory;\r
      rve -= j;\r
      rvbits = nbits;\r
      }\r
    ab = d2b(dval(adj), &abe, &abits);\r
    if (ab == NULL)\r
      return STRTOG_NoMemory;\r
    if (abe < 0)\r
      rshift(ab, -abe);\r
    else if (abe > 0)\r
      ab = lshift(ab, abe);\r
    rvb0 = rvb;\r
    if (asub) {\r
      /* rv -= adj; */\r
      j = hi0bits(rvb->x[rvb->wds-1]);\r
      rvb = diff(rvb, ab);\r
      if (rvb == NULL)\r
        return STRTOG_NoMemory;\r
      k = rvb0->wds - 1;\r
      if (denorm)\r
        /* do nothing */;\r
      else if (rvb->wds <= k\r
        || hi0bits( rvb->x[k]) >\r
           hi0bits(rvb0->x[k])) {\r
        /* unlikely; can only have lost 1 high bit */\r
        if (rve1 == emin) {\r
          --rvbits;\r
          denorm = 1;\r
          }\r
        else {\r
          rvb = lshift(rvb, 1);\r
          if (rvb == NULL)\r
            return STRTOG_NoMemory;\r
          --rve;\r
          --rve1;\r
          L = finished = 0;\r
          }\r
        }\r
      }\r
    else {\r
      rvb = sum(rvb, ab);\r
      if (rvb == NULL)\r
        return STRTOG_NoMemory;\r
      k = rvb->wds - 1;\r
      if (k >= rvb0->wds\r
       || hi0bits(rvb->x[k]) < hi0bits(rvb0->x[k])) {\r
        if (denorm) {\r
          if (++rvbits == nbits)\r
            denorm = 0;\r
          }\r
        else {\r
          rshift(rvb, 1);\r
          rve++;\r
          rve1++;\r
          L = 0;\r
          }\r
        }\r
      }\r
    Bfree(ab);\r
    Bfree(rvb0);\r
    if (finished)\r
      break;\r
\r
    z = rve + rvbits;\r
    if (y == z && L) {\r
      /* Can we stop now? */\r
      tol = dval(adj) * 5e-16; /* > max rel error */\r
      dval(adj) = adj0 - .5;\r
      if (dval(adj) < -tol) {\r
        if (adj0 > tol) {\r
          irv |= inex;\r
          break;\r
          }\r
        }\r
      else if (dval(adj) > tol && adj0 < 1. - tol) {\r
        irv |= inex;\r
        break;\r
        }\r
      }\r
    bb0 = denorm ? 0 : trailz(rvb);\r
    Bfree(bb);\r
    Bfree(bd);\r
    Bfree(bs);\r
    Bfree(delta);\r
    }\r
  if (!denorm && (j = nbits - rvbits)) {\r
    if (j > 0)\r
      rvb = lshift(rvb, j);\r
    else\r
      rshift(rvb, -j);\r
    rve -= j;\r
    }\r
  *expt = rve;\r
  Bfree(bb);\r
  Bfree(bd);\r
  Bfree(bs);\r
  Bfree(bd0);\r
  Bfree(delta);\r
  if (rve > fpi->emax) {\r
 huge:\r
    rvb->wds = 0;\r
    irv = STRTOG_Infinite | STRTOG_Overflow | STRTOG_Inexhi;\r
#ifndef NO_ERRNO\r
    errno = ERANGE;\r
#endif\r
#ifdef INFNAN_CHECK\r
 infnanexp:\r
#endif\r
    *expt = fpi->emax + 1;\r
    }\r
 ret:\r
  if (denorm) {\r
    if (sudden_underflow) {\r
      rvb->wds = 0;\r
      irv = STRTOG_Underflow | STRTOG_Inexlo;\r
      }\r
    else  {\r
      irv = (irv & ~STRTOG_Retmask) |\r
        (rvb->wds > 0 ? STRTOG_Denormal : STRTOG_Zero);\r
      if (irv & STRTOG_Inexact)\r
        irv |= STRTOG_Underflow;\r
      }\r
    }\r
  if (se)\r
    *se = __UNCONST(s);\r
  if (sign)\r
    irv |= STRTOG_Neg;\r
  if (rvb) {\r
    copybits(bits, nbits, rvb);\r
    Bfree(rvb);\r
    }\r
  return irv;\r
  }\r