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/* mpf_cmp_ui -- Compare a float with an unsigned integer.
Copyright 1993-1995, 1999, 2001, 2002 Free Software Foundation, Inc.
This file is part of the GNU MP Library.
The GNU MP 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 3 of the License, or (at your
option) any later version.
The GNU MP 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 GNU MP Library. If not, see https://www.gnu.org/licenses/. */
#include "gmp.h"
#include "gmp-impl.h"
int
mpf_cmp_ui (mpf_srcptr u, unsigned long int vval) __GMP_NOTHROW
{
mp_srcptr up;
mp_size_t usize;
mp_exp_t uexp;
mp_limb_t ulimb;
uexp = u->_mp_exp;
usize = u->_mp_size;
/* 1. Is U negative? */
if (usize < 0)
return -1;
/* We rely on usize being non-negative in the code that follows. */
if (vval == 0)
return usize != 0;
/* 2. Are the exponents different (V's exponent == 1)? */
#if GMP_NAIL_BITS != 0
if (uexp > 1 + (vval > GMP_NUMB_MAX))
return 1;
if (uexp < 1 + (vval > GMP_NUMB_MAX))
return -1;
#else
if (uexp > 1)
return 1;
if (uexp < 1)
return -1;
#endif
up = u->_mp_d;
ulimb = up[usize - 1];
#if GMP_NAIL_BITS != 0
if (usize >= 2 && uexp == 2)
{
if ((ulimb >> GMP_NAIL_BITS) != 0)
return 1;
ulimb = (ulimb << GMP_NUMB_BITS) | up[usize - 2];
usize--;
}
#endif
usize--;
/* 3. Compare the most significant mantissa limb with V. */
if (ulimb > vval)
return 1;
else if (ulimb < vval)
return -1;
/* Ignore zeroes at the low end of U. */
while (*up == 0)
{
up++;
usize--;
}
/* 4. Now, if the number of limbs are different, we have a difference
since we have made sure the trailing limbs are not zero. */
if (usize > 0)
return 1;
/* Wow, we got zero even if we tried hard to avoid it. */
return 0;
}
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