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/* mpfr_set_str_raw -- set a floating-point number from a binary string
Copyright (C) 1999 Free Software Foundation.
This file is part of the MPFR Library.
The MPFR Library is free software; you can redistribute it and/or modify
it under the terms of the GNU Library General Public License as published by
the Free Software Foundation; either version 2 of the License, or (at your
option) any later version.
The MPFR Library 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 Library General Public
License for more details.
You should have received a copy of the GNU Library General Public License
along with the MPFR Library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA. */
#include <stdio.h>
#include <stdlib.h>
#ifdef HAS_STRING_H
#include <string.h>
#else
#include <strings.h>
#endif
#include "gmp.h"
#include "gmp-impl.h"
#include "longlong.h"
#include "mpfr.h"
#include "mpfr-impl.h"
/* Currently the number should be of the form +/- xxxx.xxxxxxEyy, with
decimal exponent. The mantissa of x is supposed to be large enough
to hold all the bits of str. */
void
#if __STDC__
mpfr_set_str_raw (mpfr_ptr x, char *str)
#else
mpfr_set_str_raw (x, str)
mpfr_ptr x;
char *str;
#endif
{
char *str2, *str0, negative = 0;
unsigned long j, l, k = 0, xsize, cnt, alloc; mp_limb_t *xp;
long expn = 0, e; char *endstr2;
xp = MPFR_MANT(x);
xsize = 1 + (MPFR_PREC(x)-1)/BITS_PER_MP_LIMB;
alloc = (strlen(str)+1) * sizeof(char);
str0 = str2 = (char *) (*__gmp_allocate_func) (alloc);
if (*str == '-') { negative = 1; str++; }
else if (*str == '+') str++;
if (*str == 'I')
{
MPFR_SET_INF(x);
if (MPFR_ISNEG(x) != negative) MPFR_CHANGE_SIGN(x);
return;
}
if (*str == 'N')
{
MPFR_SET_NAN(x);
return;
}
MPFR_CLEAR_FLAGS(x);
while (*str == '0') { str++; }
while (*str == '0' || *str == '1')
{ *(str2++) = *(str++); k++; }
if (*str == '.')
{
str++;
while (*str == '0' || *str == '1')
{ *(str2++) = *(str++); }
if (*str == '[') { while (*str != ']') str++; }
}
if (*str == '[') { while (*str != ']') str++; }
if (*str == 'e' || *str == 'E')
{
e = atol(++str); /* signed exponent after 'e' or 'E' */
expn = k + e;
if (expn < e)
fprintf(stderr, "Warning: overflow in exponent in Str -> mpfr\n");
}
else expn=k;
endstr2 = str2;
*str2 = (char) 0; /* end of string */
l = (strlen(str0) - 1) / BITS_PER_MP_LIMB + 1; str2 = str0;
if (l > xsize) {
fprintf (stderr, "Error: mantissa larger than precision of destination variable in mpfr_set_str_raw\n");
exit (1);
}
/* str2[0]..endstr2[-1] contains the mantissa */
for (k = 1; k <= l; k++)
{
j = 0;
xp[xsize - k] = 0;
while (str2<endstr2 && j < BITS_PER_MP_LIMB)
{
xp[xsize - k] = (xp[xsize - k] << 1) + (*str2 - '0');
str2++; j++;
}
xp[xsize - k] <<= (BITS_PER_MP_LIMB - j);
}
for (; k <= xsize; k++) { xp[xsize - k] = 0; }
count_leading_zeros(cnt, xp[xsize - 1]);
if (cnt) mpn_lshift(xp, xp, xsize, cnt);
MPFR_EXP(x) = expn - cnt;
MPFR_SIZE(x) = xsize; if (negative) MPFR_CHANGE_SIGN(x);
(*__gmp_free_func) (str0, alloc);
/* May change to take into account : syntax errors, overflow in exponent,
string truncated because of size of x */
}
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