Subversion Repositories openrisc_2011-10-31

/* 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/>.  */

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

 *    BID128_to_string

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

#define BID_128RES

#include <stdio.h>

#include "bid_internal.h"

#include "bid128_2_str.h"

#include "bid128_2_str_macros.h"

extern int bid128_coeff_2_string (UINT64 X_hi, UINT64 X_lo,

                                  char *char_ptr);

#if DECIMAL_CALL_BY_REFERENCE

void

bid128_to_string (char *str,

                  UINT128 *

                  px _EXC_FLAGS_PARAM _EXC_MASKS_PARAM

                  _EXC_INFO_PARAM) {

  UINT128 x;

#else

void

bid128_to_string (char *str, UINT128 x

    _EXC_FLAGS_PARAM _EXC_MASKS_PARAM _EXC_INFO_PARAM) {

#endif

  UINT64 x_sign;

  UINT64 x_exp;

  int exp;      // unbiased exponent

  // Note: C1.w[1], C1.w[0] represent x_signif_hi, x_signif_lo (all are UINT64)

  int ind;

  UINT128 C1;

  unsigned int k = 0; // pointer in the string

  unsigned int d0, d123;

  UINT64 HI_18Dig, LO_18Dig, Tmp;

  UINT32 MiDi[12], *ptr;

  char *c_ptr_start, *c_ptr;

  int midi_ind, k_lcv, len;

#if DECIMAL_CALL_BY_REFERENCE

  x = *px;

#endif

  BID_SWAP128(x);

  // check for NaN or Infinity

  if ((x.w[1] & MASK_SPECIAL) == MASK_SPECIAL) {

    // x is special

    if ((x.w[1] & MASK_NAN) == MASK_NAN) { // x is NAN

      if ((x.w[1] & MASK_SNAN) == MASK_SNAN) { // x is SNAN

        // set invalid flag

    str[0] = ((SINT64)x.w[1]<0)? '-':'+';

        str[1] = 'S';

        str[2] = 'N';

        str[3] = 'a';

        str[4] = 'N';

        str[5] = '\0';

      } else { // x is QNaN

    str[0] = ((SINT64)x.w[1]<0)? '-':'+';

        str[1] = 'Q';

        str[2] = 'N';

        str[3] = 'a';

        str[4] = 'N';

        str[5] = '\0';

      }

    } else { // x is not a NaN, so it must be infinity

      if ((x.w[1] & MASK_SIGN) == 0x0ull) { // x is +inf

        str[0] = '+';

        str[1] = 'I';

        str[2] = 'n';

        str[3] = 'f';

        str[4] = '\0';

      } else { // x is -inf 

        str[0] = '-';

        str[1] = 'I';

        str[2] = 'n';

        str[3] = 'f';

        str[4] = '\0';

      }

    }

    return;

  } else if (((x.w[1] & MASK_COEFF) == 0x0ull) && (x.w[0] == 0x0ull)) {

    // x is 0

    len = 0;

    //determine if +/-

    if (x.w[1] & MASK_SIGN)

      str[len++] = '-';

    else

      str[len++] = '+';

    str[len++] = '0';

    str[len++] = 'E';

    // extract the exponent and print

    exp = (int) (((x.w[1] & MASK_EXP) >> 49) - 6176);

        if(exp > (((0x5ffe)>>1) - (6176))) {

                exp = (int) ((((x.w[1]<<2) & MASK_EXP) >> 49) - 6176);

        }

    if (exp >= 0) {

      str[len++] = '+';

      len += sprintf (str + len, "%u", exp);// should not use sprintf (should 

      // use sophisticated algorithm, since we know range of exp is limited)

      str[len++] = '\0';

    } else {

      len += sprintf (str + len, "%d", exp);// should not use sprintf (should 

      // use sophisticated algorithm, since we know range of exp is limited)

      str[len++] = '\0';

    }

    return;

  } else { // x is not special and is not zero

    // unpack x

    x_sign = x.w[1] & MASK_SIGN;// 0 for positive, MASK_SIGN for negative

    x_exp = x.w[1] & MASK_EXP;// biased and shifted left 49 bit positions

    if ((x.w[1] & 0x6000000000000000ull) == 0x6000000000000000ull)

       x_exp = (x.w[1]<<2) & MASK_EXP;// biased and shifted left 49 bit positions

    C1.w[1] = x.w[1] & MASK_COEFF;

    C1.w[0] = x.w[0];

    exp = (x_exp >> 49) - 6176;

    // determine sign's representation as a char

    if (x_sign)

      str[k++] = '-';// negative number

    else

      str[k++] = '+';// positive number

    // determine coefficient's representation as a decimal string

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

    if ((C1.w[1] > 0x0001ed09bead87c0ull) ||

        (C1.w[1] == 0x0001ed09bead87c0ull &&

        (C1.w[0] > 0x378d8e63ffffffffull)) ||

        ((x.w[1] & 0x6000000000000000ull) == 0x6000000000000000ull) ||

        ((C1.w[1] == 0) && (C1.w[0] == 0))) {

      str[k++] = '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 = C1.w[0] >> 59;

      LO_18Dig = (C1.w[0] << 5) >> 5;

      Tmp += (C1.w[1] << 5);

      HI_18Dig = 0;

      k_lcv = 0;

      // Tmp = {C1.w[1]{49:0}, C1.w[0]{63:59}}

      // Lo_18Dig = {C1.w[0]{58:0}}

      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;

      if (HI_18Dig == 0LL) {

        __L1_Split_MiDi_6_Lead (LO_18Dig, ptr);

      } else {

        __L1_Split_MiDi_6_Lead (HI_18Dig, ptr);

        __L1_Split_MiDi_6 (LO_18Dig, ptr);

      }

      len = ptr - MiDi;

      c_ptr_start = &(str[k]);

      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);

      }

      k = k + (c_ptr - c_ptr_start);

    }

    // print E and sign of exponent

    str[k++] = 'E';

    if (exp < 0) {

      exp = -exp;

      str[k++] = '-';

    } else {

      str[k++] = '+';

    }

    // determine exponent's representation as a decimal string

    // d0 = exp / 1000;

    // Use Property 1

    d0 = (exp * 0x418a) >> 24;// 0x418a * 2^-24 = (10^(-3))RP,15

    d123 = exp - 1000 * d0;

    if (d0) { // 1000 <= exp <= 6144 => 4 digits to return

      str[k++] = d0 + 0x30;// ASCII for decimal digit d0

      ind = 3 * d123;

      str[k++] = char_table3[ind];

      str[k++] = char_table3[ind + 1];

      str[k++] = char_table3[ind + 2];

    } else { // 0 <= exp <= 999 => d0 = 0

      if (d123 < 10) { // 0 <= exp <= 9 => 1 digit to return

        str[k++] = d123 + 0x30;// ASCII

      } else if (d123 < 100) { // 10 <= exp <= 99 => 2 digits to return

        ind = 2 * (d123 - 10);

        str[k++] = char_table2[ind];

        str[k++] = char_table2[ind + 1];

      } else { // 100 <= exp <= 999 => 3 digits to return

        ind = 3 * d123;

        str[k++] = char_table3[ind];

        str[k++] = char_table3[ind + 1];

        str[k++] = char_table3[ind + 2];

      }

    }

    str[k] = '\0';

  }

  return;

}

#define MAX_FORMAT_DIGITS_128   34

#define MAX_STRING_DIGITS_128   100

#define MAX_SEARCH              MAX_STRING_DIGITS_128-MAX_FORMAT_DIGITS_128-1

#if DECIMAL_CALL_BY_REFERENCE

void

bid128_from_string (UINT128 * pres,

                    char *ps _RND_MODE_PARAM _EXC_FLAGS_PARAM

                    _EXC_MASKS_PARAM _EXC_INFO_PARAM) {

#else

UINT128

bid128_from_string (char *ps _RND_MODE_PARAM _EXC_FLAGS_PARAM

                    _EXC_MASKS_PARAM _EXC_INFO_PARAM) {

#endif

  UINT128 CX, res;

  UINT64 sign_x, coeff_high, coeff_low, coeff2, coeff_l2, carry = 0x0ull,

    scale_high, right_radix_leading_zeros;

  int ndigits_before, ndigits_after, ndigits_total, dec_expon, sgn_exp,

    i, d2, rdx_pt_enc;

  char c, buffer[MAX_STRING_DIGITS_128];

  int save_rnd_mode;

  int save_fpsf;

#if DECIMAL_CALL_BY_REFERENCE

#if !DECIMAL_GLOBAL_ROUNDING

  _IDEC_round rnd_mode = *prnd_mode;

#endif

#endif

  save_rnd_mode = rnd_mode; // dummy

  save_fpsf = *pfpsf; // dummy

  right_radix_leading_zeros = rdx_pt_enc = 0;

  // if null string, return NaN

  if (!ps) {

    res.w[1] = 0x7c00000000000000ull;

    res.w[0] = 0;

    BID_RETURN (res);

  }

  // eliminate leading white space

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

    ps++;

  // c gets first character

  c = *ps;

  // if c is null or not equal to a (radix point, negative sign, 

  // positive sign, or number) it might be SNaN, sNaN, Infinity

  if (!c

      || (c != '.' && c != '-' && c != '+'

          && ((unsigned) (c - '0') > 9))) {

    res.w[0] = 0;

    // 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.w[1] = 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.w[1] = 0x7e00000000000000ull;

      BID_RETURN (res);

    } else {

      // return qNaN

      res.w[1] = 0x7c00000000000000ull;

      BID_RETURN (res);

    }

  }

  // if +Inf, -Inf, +Infinity, or -Infinity (case insensitive check for 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]))) { // ci check for infinity

    res.w[0] = 0;

    if (c == '+')

      res.w[1] = 0x7800000000000000ull;

    else if (c == '-')

      res.w[1] = 0xf800000000000000ull;

    else

      res.w[1] = 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') {

    res.w[0] = 0;

    if (c == '-')

      res.w[1] = 0xfe00000000000000ull;

    else

      res.w[1] = 0x7e00000000000000ull;

    BID_RETURN (res);

  }

  // set up sign_x to be OR'ed with the upper word later

  if (c == '-')

    sign_x = 0x8000000000000000ull;

  else

    sign_x = 0;

  // go to 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 != '.' && ((unsigned) (c - '0') > 9)) {

    res.w[1] = 0x7c00000000000000ull | sign_x;

    res.w[0] = 0;

    BID_RETURN (res);

  }

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

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

    // 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.w[1] =

              (0x3040000000000000ull -

               (right_radix_leading_zeros << 49)) | sign_x;

            res.w[0] = 0;

            BID_RETURN (res);

          }

          ps = ps + 1;

        } else {

          // if 2 radix points, return NaN

          res.w[1] = 0x7c00000000000000ull | sign_x;

          res.w[0] = 0;

          BID_RETURN (res);

        }

      } else if (!*(ps)) {

        //res.w[1] = 0x3040000000000000ull | sign_x;

        res.w[1] =

          (0x3040000000000000ull -

           (right_radix_leading_zeros << 49)) | sign_x;

        res.w[0] = 0;

        BID_RETURN (res);

      }

    }

  }

  c = *ps;

  // initialize local variables

  ndigits_before = ndigits_after = ndigits_total = 0;

  sgn_exp = 0;

  // pstart_coefficient = ps;

  if (!rdx_pt_enc) {

    // investigate string (before radix point)

    while ((unsigned) (c - '0') <= 9

           && ndigits_before < MAX_STRING_DIGITS_128) {

      buffer[ndigits_before] = c;

      ps++;

      c = *ps;

      ndigits_before++;

    }

    ndigits_total = ndigits_before;

    if (c == '.') {

      ps++;

      if ((c = *ps)) {

        // investigate string (after radix point)

        while ((unsigned) (c - '0') <= 9

               && ndigits_total < MAX_STRING_DIGITS_128) {

          buffer[ndigits_total] = c;

          ps++;

          c = *ps;

          ndigits_total++;

        }

        ndigits_after = ndigits_total - ndigits_before;

      }

    }

  } else {

    // we encountered a radix point while detecting zeros

    //if (c = *ps){

    c = *ps;

    ndigits_total = 0;

    // investigate string (after radix point)

    while ((unsigned) (c - '0') <= 9

           && ndigits_total < MAX_STRING_DIGITS_128) {

      buffer[ndigits_total] = c;

      ps++;

      c = *ps;

      ndigits_total++;

    }

    ndigits_after = ndigits_total - ndigits_before;

  }

  // get exponent

  dec_expon = 0;

  if (ndigits_total < MAX_STRING_DIGITS_128) {

    if (c) {

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

        // return NaN

        res.w[1] = 0x7c00000000000000ull;

        res.w[0] = 0;

        BID_RETURN (res);

      }

      ps++;

      c = *ps;

      if (((unsigned) (c - '0') > 9)

          && ((c != '+' && c != '-') || (unsigned) (ps[1] - '0') > 9)) {

        // return NaN

        res.w[1] = 0x7c00000000000000ull;

        res.w[0] = 0;

        BID_RETURN (res);

      }

      if (c == '-') {

        sgn_exp = -1;

        ps++;

        c = *ps;

      } else if (c == '+') {

        ps++;

        c = *ps;

      }

      dec_expon = c - '0';

      i = 1;

      ps++;

      c = *ps - '0';

      while (((unsigned) c) <= 9 && i < 7) {

        d2 = dec_expon + dec_expon;

        dec_expon = (d2 << 2) + d2 + c;

        ps++;

        c = *ps - '0';

        i++;

      }

    }

    dec_expon = (dec_expon + sgn_exp) ^ sgn_exp;

  }

  if (ndigits_total <= MAX_FORMAT_DIGITS_128) {

    dec_expon +=

      DECIMAL_EXPONENT_BIAS_128 - ndigits_after -

      right_radix_leading_zeros;

    if (dec_expon < 0) {

      res.w[1] = 0 | sign_x;

      res.w[0] = 0;

    }

    if (ndigits_total == 0) {

      CX.w[0] = 0;

      CX.w[1] = 0;

    } else if (ndigits_total <= 19) {

      coeff_high = buffer[0] - '0';

      for (i = 1; i < ndigits_total; i++) {

        coeff2 = coeff_high + coeff_high;

        coeff_high = (coeff2 << 2) + coeff2 + buffer[i] - '0';

      }

      CX.w[0] = coeff_high;

      CX.w[1] = 0;

    } else {

      coeff_high = buffer[0] - '0';

      for (i = 1; i < ndigits_total - 17; i++) {

        coeff2 = coeff_high + coeff_high;

        coeff_high = (coeff2 << 2) + coeff2 + buffer[i] - '0';

      }

      coeff_low = buffer[i] - '0';

      i++;

      for (; i < ndigits_total; i++) {

        coeff_l2 = coeff_low + coeff_low;

        coeff_low = (coeff_l2 << 2) + coeff_l2 + buffer[i] - '0';

      }

      // now form the coefficient as coeff_high*10^19+coeff_low+carry

      scale_high = 100000000000000000ull;

      __mul_64x64_to_128_fast (CX, coeff_high, scale_high);

      CX.w[0] += coeff_low;

      if (CX.w[0] < coeff_low)

        CX.w[1]++;

    }

    get_BID128 (&res, sign_x, dec_expon, CX,&rnd_mode,pfpsf);

    BID_RETURN (res);

  } else {

    // simply round using the digits that were read

    dec_expon +=

      ndigits_before + DECIMAL_EXPONENT_BIAS_128 -

      MAX_FORMAT_DIGITS_128 - right_radix_leading_zeros;

    if (dec_expon < 0) {

      res.w[1] = 0 | sign_x;

      res.w[0] = 0;

    }

    coeff_high = buffer[0] - '0';

    for (i = 1; i < MAX_FORMAT_DIGITS_128 - 17; i++) {

      coeff2 = coeff_high + coeff_high;

      coeff_high = (coeff2 << 2) + coeff2 + buffer[i] - '0';

    }

    coeff_low = buffer[i] - '0';

    i++;

    for (; i < MAX_FORMAT_DIGITS_128; i++) {

      coeff_l2 = coeff_low + coeff_low;

      coeff_low = (coeff_l2 << 2) + coeff_l2 + buffer[i] - '0';

    }

        switch(rnd_mode) {

        case ROUNDING_TO_NEAREST:

    carry = ((unsigned) ('4' - buffer[i])) >> 31;

    if ((buffer[i] == '5' && !(coeff_low & 1)) || dec_expon < 0) {

      if (dec_expon >= 0) {

        carry = 0;