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/* mpfr_set_str_binary -- set a floating-point number from a binary string
Copyright 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
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 Lesser General Public License as published by
the Free Software Foundation; either version 2.1 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 Lesser General Public
License for more details.
You should have received a copy of the GNU Lesser 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 <stdlib.h>
#include <string.h>
#include <errno.h>
#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
mpfr_set_str_binary (mpfr_ptr x, const char *str)
{
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;
if (*str == '-')
{
negative = 1;
str++;
}
else if (*str == '+')
str++;
if (*str == 'N')
{
MPFR_SET_NAN(x);
__gmpfr_flags |= MPFR_FLAGS_NAN;
return;
}
if (*str == 'I')
{
MPFR_CLEAR_NAN(x);
MPFR_SET_INF(x);
if (MPFR_ISNEG(x) != negative)
MPFR_CHANGE_SIGN(x);
return;
}
MPFR_CLEAR_FLAGS(x);
str0 = str2 = (char *) (*__gmp_allocate_func) (alloc);
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')
{
char *end;
e = strtol (++str, &end, 10); /* signed exponent after 'e' or 'E' */
MPFR_ASSERTN (*end == '\0' && errno != ERANGE);
expn = k + e;
MPFR_ASSERTN (expn >= e);
}
else
expn = k;
endstr2 = str2;
l = endstr2 - str0; /* length of mantissa */
if (l == 0)
{ /* input is zero */
MPFR_SET_ZERO(x);
}
else
{
l = (l - 1) / BITS_PER_MP_LIMB + 1;
str2 = str0;
MPFR_ASSERTN (l <= xsize);
/* 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_SET_EXP (x, expn - cnt);
if (MPFR_ISNEG(x) != 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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