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/* Copyright (C) 2007, 2009  Free Software Foundation, Inc.

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it under

the terms of the GNU General Public License as published by the Free

Software Foundation; either version 3, or (at your option) any later

version.

GCC is distributed in the hope that it will be useful, but WITHOUT ANY

WARRANTY; without even the implied warranty of MERCHANTABILITY or

FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

for more details.

Under Section 7 of GPL version 3, you are granted additional

permissions described in the GCC Runtime Library Exception, version

3.1, as published by the Free Software Foundation.

You should have received a copy of the GNU General Public License and

a copy of the GCC Runtime Library Exception along with this program;

see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see

<http://www.gnu.org/licenses/>.  */

#include <ctype.h>

#include "bid_internal.h"

#include "bid128_2_str.h"

#include "bid128_2_str_macros.h"

#define MAX_FORMAT_DIGITS     16

#define DECIMAL_EXPONENT_BIAS 398

#define MAX_DECIMAL_EXPONENT  767

#if DECIMAL_CALL_BY_REFERENCE

void

bid64_to_string (char *ps, UINT64 * px

                 _EXC_FLAGS_PARAM _EXC_MASKS_PARAM _EXC_INFO_PARAM) {

  UINT64 x;

#else

void

bid64_to_string (char *ps, UINT64 x

                 _EXC_FLAGS_PARAM _EXC_MASKS_PARAM _EXC_INFO_PARAM) {

#endif

// the destination string (pointed to by ps) must be pre-allocated

  UINT64 sign_x, coefficient_x, D, ER10;

  int istart, exponent_x, j, digits_x, bin_expon_cx;

  int_float tempx;

  UINT32 MiDi[12], *ptr;

  UINT64 HI_18Dig, LO_18Dig, Tmp;

  char *c_ptr_start, *c_ptr;

  int midi_ind, k_lcv, len;

  unsigned int save_fpsf;

#if DECIMAL_CALL_BY_REFERENCE

  x = *px;

#endif

  save_fpsf = *pfpsf; // place holder only

  // unpack arguments, check for NaN or Infinity

  if (!unpack_BID64 (&sign_x, &exponent_x, &coefficient_x, x)) {

    // x is Inf. or NaN or 0

    // Inf or NaN?

    if ((x & 0x7800000000000000ull) == 0x7800000000000000ull) {

      if ((x & 0x7c00000000000000ull) == 0x7c00000000000000ull) {

    ps[0] = (sign_x) ? '-' : '+';

    ps[1] = ((x & MASK_SNAN) == MASK_SNAN)? 'S':'Q';

        ps[2] = 'N';

        ps[3] = 'a';

        ps[4] = 'N';

        ps[5] = 0;

        return;

      }

      // x is Inf

      ps[0] = (sign_x) ? '-' : '+';

      ps[1] = 'I';

      ps[2] = 'n';

      ps[3] = 'f';

      ps[4] = 0;

      return;

    }

    // 0

    istart = 0;

    if (sign_x) {

      ps[istart++] = '-';

    }

    ps[istart++] = '0';

    ps[istart++] = 'E';

    exponent_x -= 398;

    if (exponent_x < 0) {

      ps[istart++] = '-';

      exponent_x = -exponent_x;

    } else

      ps[istart++] = '+';

    if (exponent_x) {

      // get decimal digits in coefficient_x

      tempx.d = (float) exponent_x;

      bin_expon_cx = ((tempx.i >> 23) & 0xff) - 0x7f;

      digits_x = estimate_decimal_digits[bin_expon_cx];

      if ((UINT64)exponent_x >= power10_table_128[digits_x].w[0])

        digits_x++;

      j = istart + digits_x - 1;

      istart = j + 1;

      // 2^32/10

      ER10 = 0x1999999a;

      while (exponent_x > 9) {

        D = (UINT64) exponent_x *ER10;

        D >>= 32;

        exponent_x = exponent_x - (D << 1) - (D << 3);

        ps[j--] = '0' + (char) exponent_x;

        exponent_x = D;

      }

      ps[j] = '0' + (char) exponent_x;

    } else {

      ps[istart++] = '0';

    }

    ps[istart] = 0;

    return;

  }

  // convert expon, coeff to ASCII

  exponent_x -= DECIMAL_EXPONENT_BIAS;

  ER10 = 0x1999999a;

  istart = 0;

  if (sign_x) {

    ps[0] = '-';

    istart = 1;

  }

  // if zero or non-canonical, set coefficient to '0'

  if ((coefficient_x > 9999999999999999ull) ||  // non-canonical

      ((coefficient_x == 0))     // significand is zero

    ) {

    ps[istart++] = '0';

  } else {

    /* ****************************************************

       This takes a bid coefficient in C1.w[1],C1.w[0]

       and put the converted character sequence at location

       starting at &(str[k]). The function returns the number

       of MiDi returned. Note that the character sequence

       does not have leading zeros EXCEPT when the input is of

       zero value. It will then output 1 character '0'

       The algorithm essentailly tries first to get a sequence of

       Millenial Digits "MiDi" and then uses table lookup to get the

       character strings of these MiDis.

       **************************************************** */

    /* Algorithm first decompose possibly 34 digits in hi and lo

       18 digits. (The high can have at most 16 digits). It then

       uses macro that handle 18 digit portions.

       The first step is to get hi and lo such that

       2^(64) C1.w[1] + C1.w[0] = hi * 10^18  + lo,   0 <= lo < 10^18.

       We use a table lookup method to obtain the hi and lo 18 digits.

       [C1.w[1],C1.w[0]] = c_8 2^(107) + c_7 2^(101) + ... + c_0 2^(59) + d

       where 0 <= d < 2^59 and each c_j has 6 bits. Because d fits in

       18 digits,  we set hi = 0, and lo = d to begin with.

       We then retrieve from a table, for j = 0, 1, ..., 8

       that gives us A and B where c_j 2^(59+6j) = A * 10^18 + B.

       hi += A ; lo += B; After each accumulation into lo, we normalize

       immediately. So at the end, we have the decomposition as we need. */

    Tmp = coefficient_x >> 59;

    LO_18Dig = (coefficient_x << 5) >> 5;

    HI_18Dig = 0;

    k_lcv = 0;

    while (Tmp) {

      midi_ind = (int) (Tmp & 0x000000000000003FLL);

      midi_ind <<= 1;

      Tmp >>= 6;

      HI_18Dig += mod10_18_tbl[k_lcv][midi_ind++];

      LO_18Dig += mod10_18_tbl[k_lcv++][midi_ind];

      __L0_Normalize_10to18 (HI_18Dig, LO_18Dig);

    }

    ptr = MiDi;

    __L1_Split_MiDi_6_Lead (LO_18Dig, ptr);

    len = ptr - MiDi;

    c_ptr_start = &(ps[istart]);

    c_ptr = c_ptr_start;

    /* now convert the MiDi into character strings */

    __L0_MiDi2Str_Lead (MiDi[0], c_ptr);

    for (k_lcv = 1; k_lcv < len; k_lcv++) {

      __L0_MiDi2Str (MiDi[k_lcv], c_ptr);

    }

    istart = istart + (c_ptr - c_ptr_start);

  }

  ps[istart++] = 'E';

  if (exponent_x < 0) {

    ps[istart++] = '-';

    exponent_x = -exponent_x;

  } else

    ps[istart++] = '+';

  if (exponent_x) {

    // get decimal digits in coefficient_x

    tempx.d = (float) exponent_x;

    bin_expon_cx = ((tempx.i >> 23) & 0xff) - 0x7f;

    digits_x = estimate_decimal_digits[bin_expon_cx];

    if ((UINT64)exponent_x >= power10_table_128[digits_x].w[0])

      digits_x++;

    j = istart + digits_x - 1;

    istart = j + 1;

    // 2^32/10

    ER10 = 0x1999999a;

    while (exponent_x > 9) {

      D = (UINT64) exponent_x *ER10;

      D >>= 32;

      exponent_x = exponent_x - (D << 1) - (D << 3);

      ps[j--] = '0' + (char) exponent_x;

      exponent_x = D;

    }

    ps[j] = '0' + (char) exponent_x;

  } else {

    ps[istart++] = '0';

  }

  ps[istart] = 0;

  return;

}

#if DECIMAL_CALL_BY_REFERENCE

void

bid64_from_string (UINT64 * pres, char *ps

                   _RND_MODE_PARAM _EXC_FLAGS_PARAM

                   _EXC_MASKS_PARAM _EXC_INFO_PARAM) {

#else

UINT64

bid64_from_string (char *ps

                   _RND_MODE_PARAM _EXC_FLAGS_PARAM

                   _EXC_MASKS_PARAM _EXC_INFO_PARAM) {

#endif

  UINT64 sign_x, coefficient_x = 0, rounded = 0, res;

  int expon_x = 0, sgn_expon, ndigits, add_expon = 0, midpoint =

    0, rounded_up = 0;

  int dec_expon_scale = 0, right_radix_leading_zeros = 0, rdx_pt_enc =

    0;

  unsigned fpsc;

  char c;

  unsigned int save_fpsf;

#if DECIMAL_CALL_BY_REFERENCE

#if !DECIMAL_GLOBAL_ROUNDING

  _IDEC_round rnd_mode = *prnd_mode;

#endif

#endif

  save_fpsf = *pfpsf; // place holder only

  // eliminate leading whitespace

  while (((*ps == ' ') || (*ps == '\t')) && (*ps))

    ps++;

  // get first non-whitespace character

  c = *ps;

  // detect special cases (INF or NaN)

  if (!c || (c != '.' && c != '-' && c != '+' && (c < '0' || c > '9'))) {

    // Infinity?

    if ((tolower_macro (ps[0]) == 'i' && tolower_macro (ps[1]) == 'n' &&

        tolower_macro (ps[2]) == 'f') && (!ps[3] ||

        (tolower_macro (ps[3]) == 'i' &&

        tolower_macro (ps[4]) == 'n' && tolower_macro (ps[5]) == 'i' &&

        tolower_macro (ps[6]) == 't' && tolower_macro (ps[7]) == 'y' &&

        !ps[8]))) {

      res = 0x7800000000000000ull;

      BID_RETURN (res);

    }

    // return sNaN

    if (tolower_macro (ps[0]) == 's' && tolower_macro (ps[1]) == 'n' &&

        tolower_macro (ps[2]) == 'a' && tolower_macro (ps[3]) == 'n') {

        // case insensitive check for snan

      res = 0x7e00000000000000ull;

      BID_RETURN (res);

    } else {

      // return qNaN

      res = 0x7c00000000000000ull;

      BID_RETURN (res);

    }

  }

  // detect +INF or -INF

  if ((tolower_macro (ps[1]) == 'i' && tolower_macro (ps[2]) == 'n' &&

      tolower_macro (ps[3]) == 'f') && (!ps[4] ||

      (tolower_macro (ps[4]) == 'i' && tolower_macro (ps[5]) == 'n' &&

      tolower_macro (ps[6]) == 'i' && tolower_macro (ps[7]) == 't' &&

      tolower_macro (ps[8]) == 'y' && !ps[9]))) {

    if (c == '+')

      res = 0x7800000000000000ull;

    else if (c == '-')

      res = 0xf800000000000000ull;

    else

      res = 0x7c00000000000000ull;

    BID_RETURN (res);

  }

  // if +sNaN, +SNaN, -sNaN, or -SNaN

  if (tolower_macro (ps[1]) == 's' && tolower_macro (ps[2]) == 'n'

      && tolower_macro (ps[3]) == 'a' && tolower_macro (ps[4]) == 'n') {

    if (c == '-')

      res = 0xfe00000000000000ull;

    else

      res = 0x7e00000000000000ull;

    BID_RETURN (res);

  }

  // determine sign

  if (c == '-')

    sign_x = 0x8000000000000000ull;

  else

    sign_x = 0;

  // get next character if leading +/- sign

  if (c == '-' || c == '+') {

    ps++;

    c = *ps;

  }

  // if c isn't a decimal point or a decimal digit, return NaN

  if (c != '.' && (c < '0' || c > '9')) {

    // return NaN

    res = 0x7c00000000000000ull | sign_x;

    BID_RETURN (res);

  }

  rdx_pt_enc = 0;

  // detect zero (and eliminate/ignore leading zeros)

  if (*(ps) == '0' || *(ps) == '.') {

    if (*(ps) == '.') {

      rdx_pt_enc = 1;

      ps++;

    }

    // if all numbers are zeros (with possibly 1 radix point, the number is zero

    // should catch cases such as: 000.0

    while (*ps == '0') {

      ps++;

      // for numbers such as 0.0000000000000000000000000000000000001001, 

      // we want to count the leading zeros

      if (rdx_pt_enc) {

        right_radix_leading_zeros++;

      }

      // if this character is a radix point, make sure we haven't already 

      // encountered one

      if (*(ps) == '.') {

        if (rdx_pt_enc == 0) {

          rdx_pt_enc = 1;

          // if this is the first radix point, and the next character is NULL, 

          // we have a zero

          if (!*(ps + 1)) {

            res =

              ((UINT64) (398 - right_radix_leading_zeros) << 53) |

              sign_x;

            BID_RETURN (res);

          }

          ps = ps + 1;

        } else {

          // if 2 radix points, return NaN

          res = 0x7c00000000000000ull | sign_x;

          BID_RETURN (res);

        }

      } else if (!*(ps)) {

        //pres->w[1] = 0x3040000000000000ull | sign_x;

        res =

          ((UINT64) (398 - right_radix_leading_zeros) << 53) | sign_x;

        BID_RETURN (res);

      }

    }

  }

  c = *ps;

  ndigits = 0;

  while ((c >= '0' && c <= '9') || c == '.') {

    if (c == '.') {

      if (rdx_pt_enc) {

        // return NaN

        res = 0x7c00000000000000ull | sign_x;

        BID_RETURN (res);

      }

      rdx_pt_enc = 1;

      ps++;

      c = *ps;

      continue;

    }

    dec_expon_scale += rdx_pt_enc;

    ndigits++;

    if (ndigits <= 16) {

      coefficient_x = (coefficient_x << 1) + (coefficient_x << 3);

      coefficient_x += (UINT64) (c - '0');

    } else if (ndigits == 17) {

      // coefficient rounding

                switch(rnd_mode){

        case ROUNDING_TO_NEAREST:

      midpoint = (c == '5' && !(coefficient_x & 1)) ? 1 : 0;

          // if coefficient is even and c is 5, prepare to round up if 

          // subsequent digit is nonzero

      // if str[MAXDIG+1] > 5, we MUST round up

      // if str[MAXDIG+1] == 5 and coefficient is ODD, ROUND UP!

      if (c > '5' || (c == '5' && (coefficient_x & 1))) {

        coefficient_x++;

        rounded_up = 1;

        break;

        case ROUNDING_DOWN:

                if(sign_x) { coefficient_x++; rounded_up=1; }

                break;

        case ROUNDING_UP:

                if(!sign_x) { coefficient_x++; rounded_up=1; }

                break;

        case ROUNDING_TIES_AWAY:

                if(c>='5') { coefficient_x++; rounded_up=1; }

                break;

          }

        if (coefficient_x == 10000000000000000ull) {

          coefficient_x = 1000000000000000ull;

          add_expon = 1;

        }

      }

      if (c > '0')

        rounded = 1;

      add_expon += 1;

    } else { // ndigits > 17

      add_expon++;

      if (midpoint && c > '0') {

        coefficient_x++;

        midpoint = 0;

        rounded_up = 1;

      }

      if (c > '0')

        rounded = 1;

    }

    ps++;

    c = *ps;

  }

  add_expon -= (dec_expon_scale + right_radix_leading_zeros);

  if (!c) {

    res =

      fast_get_BID64_check_OF (sign_x,

                               add_expon + DECIMAL_EXPONENT_BIAS,

                               coefficient_x, 0, &fpsc);

    BID_RETURN (res);

  }

  if (c != 'E' && c != 'e') {

    // return NaN

    res = 0x7c00000000000000ull | sign_x;

    BID_RETURN (res);

  }

  ps++;

  c = *ps;

  sgn_expon = (c == '-') ? 1 : 0;

  if (c == '-' || c == '+') {

    ps++;

    c = *ps;

  }

  if (!c || c < '0' || c > '9') {

    // return NaN

    res = 0x7c00000000000000ull | sign_x;

    BID_RETURN (res);

  }

  while (c >= '0' && c <= '9') {

    expon_x = (expon_x << 1) + (expon_x << 3);

    expon_x += (int) (c - '0');

    ps++;

    c = *ps;

  }

  if (c) {

    // return NaN

    res = 0x7c00000000000000ull | sign_x;

    BID_RETURN (res);

  }

  if (sgn_expon)

    expon_x = -expon_x;

  expon_x += add_expon + DECIMAL_EXPONENT_BIAS;

  if (expon_x < 0) {

    if (rounded_up)

      coefficient_x--;

    rnd_mode = 0;

    res =

      get_BID64_UF (sign_x, expon_x, coefficient_x, rounded, rnd_mode,

                    &fpsc);

    BID_RETURN (res);

  }

  res = get_BID64 (sign_x, expon_x, coefficient_x, rnd_mode, &fpsc);

  BID_RETURN (res);

}