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Annotation of OpenXM_contrib/gmp/mpfr/set_str_raw.c, Revision 1.1.1.2

1.1       maekawa     1: /* mpfr_set_str_raw -- set a floating-point number from a binary string
                      2:
1.1.1.2 ! ohara       3: Copyright 1999, 2000, 2001 Free Software Foundation, Inc.
1.1       maekawa     4:
                      5: This file is part of the MPFR Library.
                      6:
                      7: The MPFR Library is free software; you can redistribute it and/or modify
1.1.1.2 ! ohara       8: it under the terms of the GNU Lesser General Public License as published by
        !             9: the Free Software Foundation; either version 2.1 of the License, or (at your
1.1       maekawa    10: option) any later version.
                     11:
                     12: The MPFR Library is distributed in the hope that it will be useful, but
                     13: WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
1.1.1.2 ! ohara      14: or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
1.1       maekawa    15: License for more details.
                     16:
1.1.1.2 ! ohara      17: You should have received a copy of the GNU Lesser General Public License
1.1       maekawa    18: along with the MPFR Library; see the file COPYING.LIB.  If not, write to
                     19: the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
                     20: MA 02111-1307, USA. */
                     21:
                     22: #include <stdio.h>
                     23: #include <stdlib.h>
                     24: #include <string.h>
                     25: #include "gmp.h"
                     26: #include "gmp-impl.h"
                     27: #include "longlong.h"
                     28: #include "mpfr.h"
1.1.1.2 ! ohara      29: #include "mpfr-impl.h"
1.1       maekawa    30:
                     31: /* Currently the number should be of the form +/- xxxx.xxxxxxEyy, with
                     32:    decimal exponent. The mantissa of x is supposed to be large enough
                     33:    to hold all the bits of str. */
                     34:
                     35: void
1.1.1.2 ! ohara      36: mpfr_set_str_raw (mpfr_ptr x, char *str)
1.1       maekawa    37: {
                     38:   char *str2, *str0, negative = 0;
1.1.1.2 ! ohara      39:   unsigned long j, l, k = 0, xsize, cnt, alloc; mp_limb_t *xp;
1.1       maekawa    40:   long expn = 0, e; char *endstr2;
                     41:
1.1.1.2 ! ohara      42:   xp = MPFR_MANT(x);
        !            43:   xsize = 1 + (MPFR_PREC(x) - 1) / BITS_PER_MP_LIMB;
        !            44:   alloc = (strlen(str) + 1) * sizeof(char);
1.1       maekawa    45:
1.1.1.2 ! ohara      46:   if (*str == '-')
        !            47:     {
        !            48:       negative = 1;
        !            49:       str++;
        !            50:     }
        !            51:   else if (*str == '+')
        !            52:     str++;
        !            53:
        !            54:   if (*str == 'N')
        !            55:     {
        !            56:       MPFR_SET_NAN(x);
        !            57:       __mpfr_flags |= MPFR_FLAGS_NAN;
        !            58:       return;
        !            59:     }
        !            60:
        !            61:   if (*str == 'I')
        !            62:     {
        !            63:       MPFR_CLEAR_NAN(x);
        !            64:       MPFR_SET_INF(x);
        !            65:       if (MPFR_ISNEG(x) != negative)
        !            66:        MPFR_CHANGE_SIGN(x);
        !            67:       return;
        !            68:     }
        !            69:
        !            70:   MPFR_CLEAR_FLAGS(x);
        !            71:
        !            72:   str0 = str2 = (char *) (*__gmp_allocate_func) (alloc);
1.1       maekawa    73:
                     74:   while (*str == '0') { str++; }
                     75:
                     76:   while (*str == '0' || *str == '1')
                     77:     { *(str2++) = *(str++); k++; }
                     78:
                     79:   if (*str == '.')
                     80:     {
                     81:       str++;
                     82:       while (*str == '0' || *str == '1')
                     83:        { *(str2++) = *(str++); }
                     84:
                     85:       if (*str == '[') { while (*str != ']') str++; }
                     86:     }
                     87:
                     88:   if (*str == '[') { while (*str != ']') str++; }
                     89:
                     90:   if (*str == 'e' || *str == 'E')
                     91:     {
                     92:       e = atol(++str); /* signed exponent after 'e' or 'E' */
                     93:       expn = k + e;
                     94:       if (expn < e)
                     95:          fprintf(stderr, "Warning: overflow in exponent in Str -> mpfr\n");
                     96:     }
                     97:   else expn=k;
                     98:
                     99:   endstr2 = str2;
1.1.1.2 ! ohara     100:   l = endstr2 - str0; /* length of mantissa */
        !           101:   if (l == 0) { /* input is zero */
        !           102:     MPFR_SET_ZERO(x);
        !           103:   }
        !           104:   else {
        !           105:     l = (l - 1) / BITS_PER_MP_LIMB + 1;
        !           106:     str2 = str0;
        !           107:
        !           108:     if (l > xsize) {
        !           109:       fprintf (stderr, "Error: mantissa larger than precision of destination variable in mpfr_set_str_raw\n");
        !           110:       exit (1);
1.1       maekawa   111:     }
                    112:
1.1.1.2 ! ohara     113:     /* str2[0]..endstr2[-1] contains the mantissa */
        !           114:     for (k = 1; k <= l; k++)
        !           115:       {
        !           116:        j = 0;
        !           117:        xp[xsize - k] = 0;
        !           118:        while ((str2 < endstr2) && (j < BITS_PER_MP_LIMB))
        !           119:          {
        !           120:            xp[xsize - k] = (xp[xsize - k] << 1) + (*str2 - '0');
        !           121:            str2++; j++;
        !           122:          }
        !           123:        xp[xsize - k] <<= (BITS_PER_MP_LIMB - j);
        !           124:       }
        !           125:
        !           126:     for (; k <= xsize; k++) { xp[xsize - k] = 0; }
        !           127:
        !           128:     count_leading_zeros(cnt, xp[xsize - 1]);
        !           129:     if (cnt) mpn_lshift(xp, xp, xsize, cnt);
        !           130:
        !           131:     MPFR_EXP(x) = expn - cnt;
        !           132:     if (MPFR_ISNEG(x) != negative)
        !           133:       MPFR_CHANGE_SIGN(x);
        !           134:   }
1.1       maekawa   135:
1.1.1.2 ! ohara     136:   (*__gmp_free_func) (str0, alloc);
1.1       maekawa   137:
                    138:   /* May change to take into account : syntax errors, overflow in exponent,
                    139:      string truncated because of size of x */
                    140: }