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Annotation of OpenXM/src/kan96xx/gmp-2.0.2-ssh-2/mpf/set_str.c, Revision 1.1.1.1

1.1       takayama    1: /* mpf_set_str (dest, string, base) -- Convert the string STRING
                      2:    in base BASE to a float in dest.  If BASE is zero, the leading characters
                      3:    of STRING is used to figure out the base.
                      4:
                      5: Copyright (C) 1993, 1994, 1995, 1996 Free Software Foundation, Inc.
                      6:
                      7: This file is part of the GNU MP Library.
                      8:
                      9: The GNU MP Library is free software; you can redistribute it and/or modify
                     10: it under the terms of the GNU Library General Public License as published by
                     11: the Free Software Foundation; either version 2 of the License, or (at your
                     12: option) any later version.
                     13:
                     14: The GNU MP Library is distributed in the hope that it will be useful, but
                     15: WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
                     16: or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
                     17: License for more details.
                     18:
                     19: You should have received a copy of the GNU Library General Public License
                     20: along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
                     21: the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
                     22: MA 02111-1307, USA. */
                     23:
                     24: #include <string.h>
                     25: #include <ctype.h>
                     26: #include "gmp.h"
                     27: #include "gmp-impl.h"
                     28: #include "longlong.h"
                     29:
                     30: long int strtol _PROTO ((const char *, char **ptr, int));
                     31:
                     32: static int
                     33: digit_value_in_base (c, base)
                     34:      int c;
                     35:      int base;
                     36: {
                     37:   int digit;
                     38:
                     39:   if (isdigit (c))
                     40:     digit = c - '0';
                     41:   else if (islower (c))
                     42:     digit = c - 'a' + 10;
                     43:   else if (isupper (c))
                     44:     digit = c - 'A' + 10;
                     45:   else
                     46:     return -1;
                     47:
                     48:   if (digit < base)
                     49:     return digit;
                     50:   return -1;
                     51: }
                     52:
                     53: int
                     54: #if __STDC__
                     55: mpf_set_str (mpf_ptr x, const char *str, int base)
                     56: #else
                     57: mpf_set_str (x, str, base)
                     58:      mpf_ptr x;
                     59:      const char *str;
                     60:      int base;
                     61: #endif
                     62: {
                     63:   size_t str_size;
                     64:   char *s, *begs;
                     65:   size_t i;
                     66:   mp_size_t xsize;
                     67:   int c;
                     68:   int negative;
                     69:   char *dotpos = 0;
                     70:   int expflag;
                     71:   int decimal_exponent_flag;
                     72:   TMP_DECL (marker);
                     73:
                     74:   TMP_MARK (marker);
                     75:
                     76:   c = *str;
                     77:
                     78:   /* Skip whitespace.  */
                     79:   while (isspace (c))
                     80:     c = *++str;
                     81:
                     82:   negative = 0;
                     83:   if (c == '-')
                     84:     {
                     85:       negative = 1;
                     86:       c = *++str;
                     87:     }
                     88:
                     89:   decimal_exponent_flag = base < 0;
                     90:   base = ABS (base);
                     91:
                     92:   if (digit_value_in_base (c, base == 0 ? 10 : base) < 0)
                     93:     return -1;                 /* error if no digits */
                     94:
                     95:   /* If BASE is 0, try to find out the base by looking at the initial
                     96:      characters.  */
                     97:   if (base == 0)
                     98:     {
                     99:       base = 10;
                    100: #if 0
                    101:       if (c == '0')
                    102:        {
                    103:          base = 8;
                    104:          c = *++str;
                    105:          if (c == 'x' || c == 'X')
                    106:            base = 16;
                    107:        }
                    108: #endif
                    109:     }
                    110:
                    111:   expflag = 0;
                    112:   str_size = strlen (str);
                    113:   for (i = 0; i < str_size; i++)
                    114:     {
                    115:       c = str[i];
                    116:       if (c == '@' || (base <= 10 && (c == 'e' || c == 'E')))
                    117:        {
                    118:          expflag = 1;
                    119:          str_size = i;
                    120:          break;
                    121:        }
                    122:
                    123:     }
                    124:
                    125:   s = begs = (char *) TMP_ALLOC (str_size + 1);
                    126:
                    127:   for (i = 0; i < str_size; i++)
                    128:     {
                    129:       c = *str;
                    130:       if (!isspace (c))
                    131:        {
                    132:          int dig;
                    133:
                    134:          if (c == '.')
                    135:            {
                    136:              if (dotpos != 0)
                    137:                {
                    138:                  TMP_FREE (marker);
                    139:                  return -1;
                    140:                }
                    141:              dotpos = s;
                    142:            }
                    143:          else
                    144:            {
                    145:              dig = digit_value_in_base (c, base);
                    146:              if (dig < 0)
                    147:                {
                    148:                  TMP_FREE (marker);
                    149:                  return -1;
                    150:                }
                    151:              *s++ = dig;
                    152:            }
                    153:        }
                    154:       c = *++str;
                    155:     }
                    156:
                    157:   str_size = s - begs;
                    158:
                    159:   xsize = str_size / __mp_bases[base].chars_per_limb + 2;
                    160:   {
                    161:     long exp_in_base;
                    162:     mp_size_t rsize, msize;
                    163:     int cnt, i;
                    164:     mp_ptr mp, xp, tp, rp;
                    165:     mp_limb_t cy;
                    166:     mp_exp_t exp_in_limbs;
                    167:     mp_size_t prec = x->_mp_prec;
                    168:     int divflag;
                    169:     mp_size_t xxx = 0;
                    170:
                    171:     mp = (mp_ptr) TMP_ALLOC (xsize * BYTES_PER_MP_LIMB);
                    172:     msize = mpn_set_str (mp, (unsigned char *) begs, str_size, base);
                    173:
                    174:     if (msize == 0)
                    175:       {
                    176:        x->_mp_size = 0;
                    177:        x->_mp_exp = 0;
                    178:        TMP_FREE (marker);
                    179:        return 0;
                    180:       }
                    181:
                    182:     if (expflag != 0)
                    183:       exp_in_base = strtol (str + 1, (char **) 0,
                    184:                            decimal_exponent_flag ? 10 : base);
                    185:     else
                    186:       exp_in_base = 0;
                    187:     if (dotpos != 0)
                    188:       exp_in_base -= s - dotpos;
                    189:     divflag = exp_in_base < 0;
                    190:     exp_in_base = ABS (exp_in_base);
                    191:
                    192:     if (exp_in_base == 0)
                    193:       {
                    194:        MPN_COPY (x->_mp_d, mp, msize);
                    195:        x->_mp_size = negative ? -msize : msize;
                    196:        x->_mp_exp = msize;
                    197:        TMP_FREE (marker);
                    198:        return 0;
                    199:       }
                    200:
                    201: #if 1
                    202:     rsize = (((mp_size_t) (exp_in_base / __mp_bases[base].chars_per_bit_exactly))
                    203:             / BITS_PER_MP_LIMB + 3);
                    204: #else
                    205:     count_leading_zeros (cnt, (mp_limb_t) base);
                    206:     rsize = exp_in_base - cnt * exp_in_base / BITS_PER_MP_LIMB + 1;
                    207: #endif
                    208:     rp = (mp_ptr) TMP_ALLOC (rsize * BYTES_PER_MP_LIMB);
                    209:     tp = (mp_ptr) TMP_ALLOC (rsize * BYTES_PER_MP_LIMB);
                    210:
                    211:     rp[0] = base;
                    212:     rsize = 1;
                    213:
                    214:     count_leading_zeros (cnt, exp_in_base);
                    215:
                    216:     for (i = BITS_PER_MP_LIMB - cnt - 2; i >= 0; i--)
                    217:       {
                    218:        mpn_mul_n (tp, rp, rp, rsize);
                    219:        rsize = 2 * rsize;
                    220:        rsize -= tp[rsize - 1] == 0;
                    221:        xp = tp; tp = rp; rp = xp;
                    222:
                    223:        if (((exp_in_base >> i) & 1) != 0)
                    224:          {
                    225:            cy = mpn_mul_1 (rp, rp, rsize, (mp_limb_t) base);
                    226:            rp[rsize] = cy;
                    227:            rsize += cy != 0;
                    228:          }
                    229:       }
                    230:
                    231:     if (rsize > prec)
                    232:       {
                    233:        xxx += rsize - prec;
                    234:        rp += rsize - prec;
                    235:        rsize = prec;
                    236:       }
                    237: #if 0
                    238:     if (msize > prec)
                    239:       {
                    240:        xxx -= msize - prec;
                    241:        mp += msize - prec;
                    242:        msize = prec;
                    243:       }
                    244: #endif
                    245:     if (divflag)
                    246:       {
                    247:        mp_ptr qp;
                    248:        mp_limb_t qflag;
                    249:        mp_size_t xtra;
                    250:        if (msize <= rsize)
                    251:          {
                    252:            /* Allocate extra limb for current divrem sematics. */
                    253:            mp_ptr tmp = (mp_ptr) TMP_ALLOC ((rsize + 1) * BYTES_PER_MP_LIMB);
                    254:            MPN_ZERO (tmp, rsize - msize);
                    255:            MPN_COPY (tmp + rsize - msize, mp, msize);
                    256:            mp = tmp;
                    257:            xxx += rsize - msize;
                    258:            msize = rsize;
                    259:          }
                    260:        count_leading_zeros (cnt, rp[rsize - 1]);
                    261:        if (cnt != 0)
                    262:          {
                    263:            mpn_lshift (rp, rp, rsize, cnt);
                    264:            cy = mpn_lshift (mp, mp, msize, cnt);
                    265:            if (cy)
                    266:              mp[msize++] = cy;
                    267:          }
                    268:        qp = (mp_ptr) TMP_ALLOC ((prec + 1) * BYTES_PER_MP_LIMB);
                    269:        xtra = prec - (msize - rsize);
                    270:        qflag = mpn_divrem (qp, xtra, mp, msize, rp, rsize);
                    271:        qp[prec] = qflag;
                    272:        tp = qp;
                    273:        rsize = prec + qflag;
                    274:        exp_in_limbs = rsize - xtra - xxx;
                    275:       }
                    276:     else
                    277:       {
                    278:        tp = (mp_ptr) TMP_ALLOC ((rsize + msize) * BYTES_PER_MP_LIMB);
                    279:        if (rsize > msize)
                    280:          mpn_mul (tp, rp, rsize, mp, msize);
                    281:        else
                    282:          mpn_mul (tp, mp, msize, rp, rsize);
                    283:        rsize += msize;
                    284:        rsize -= tp[rsize - 1] == 0;
                    285:        exp_in_limbs = rsize + xxx;
                    286:
                    287:        if (rsize > prec)
                    288:          {
                    289:            xxx = rsize - prec;
                    290:            tp += rsize - prec;
                    291:            rsize = prec;
                    292:            exp_in_limbs += 0;
                    293:          }
                    294:       }
                    295:
                    296:     MPN_COPY (x->_mp_d, tp, rsize);
                    297:     x->_mp_size = negative ? -rsize : rsize;
                    298:     x->_mp_exp = exp_in_limbs;
                    299:     TMP_FREE (marker);
                    300:     return 0;
                    301:   }
                    302: }

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