Blame mpf/cmp_ui.c

Packit 5c3484
/* mpf_cmp_ui -- Compare a float with an unsigned integer.
Packit 5c3484
Packit 5c3484
Copyright 1993-1995, 1999, 2001, 2002, 2015 Free Software Foundation, Inc.
Packit 5c3484
Packit 5c3484
This file is part of the GNU MP Library.
Packit 5c3484
Packit 5c3484
The GNU MP Library is free software; you can redistribute it and/or modify
Packit 5c3484
it under the terms of either:
Packit 5c3484
Packit 5c3484
  * the GNU Lesser General Public License as published by the Free
Packit 5c3484
    Software Foundation; either version 3 of the License, or (at your
Packit 5c3484
    option) any later version.
Packit 5c3484
Packit 5c3484
or
Packit 5c3484
Packit 5c3484
  * the GNU General Public License as published by the Free Software
Packit 5c3484
    Foundation; either version 2 of the License, or (at your option) any
Packit 5c3484
    later version.
Packit 5c3484
Packit 5c3484
or both in parallel, as here.
Packit 5c3484
Packit 5c3484
The GNU MP Library is distributed in the hope that it will be useful, but
Packit 5c3484
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
Packit 5c3484
or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
Packit 5c3484
for more details.
Packit 5c3484
Packit 5c3484
You should have received copies of the GNU General Public License and the
Packit 5c3484
GNU Lesser General Public License along with the GNU MP Library.  If not,
Packit 5c3484
see https://www.gnu.org/licenses/.  */
Packit 5c3484
Packit 5c3484
#include "gmp.h"
Packit 5c3484
#include "gmp-impl.h"
Packit 5c3484
Packit 5c3484
int
Packit 5c3484
mpf_cmp_ui (mpf_srcptr u, unsigned long int vval) __GMP_NOTHROW
Packit 5c3484
{
Packit 5c3484
  mp_srcptr up;
Packit 5c3484
  mp_size_t usize;
Packit 5c3484
  mp_exp_t uexp;
Packit 5c3484
  mp_limb_t ulimb;
Packit 5c3484
Packit 5c3484
  usize = SIZ (u);
Packit 5c3484
Packit 5c3484
  /* 1. Is U negative?  */
Packit 5c3484
  if (usize < 0)
Packit 5c3484
    return -1;
Packit 5c3484
  /* We rely on usize being non-negative in the code that follows.  */
Packit 5c3484
Packit 5c3484
  if (vval == 0)
Packit 5c3484
    return usize != 0;
Packit 5c3484
Packit 5c3484
  /* 2. Are the exponents different (V's exponent == 1)?  */
Packit 5c3484
  uexp = EXP (u);
Packit 5c3484
Packit 5c3484
#if GMP_NAIL_BITS != 0
Packit 5c3484
  if (uexp != 1 + (vval > GMP_NUMB_MAX))
Packit 5c3484
    return (uexp < 1 + (vval > GMP_NUMB_MAX)) ? -1 : 1;
Packit 5c3484
#else
Packit 5c3484
  if (uexp != 1)
Packit 5c3484
    return (uexp < 1) ? -1 : 1;
Packit 5c3484
#endif
Packit 5c3484
Packit 5c3484
  up = PTR (u);
Packit 5c3484
Packit 5c3484
  ASSERT (usize > 0);
Packit 5c3484
  ulimb = up[--usize];
Packit 5c3484
#if GMP_NAIL_BITS != 0
Packit 5c3484
  if (uexp == 2)
Packit 5c3484
    {
Packit 5c3484
      if ((ulimb >> GMP_NAIL_BITS) != 0)
Packit 5c3484
	return 1;
Packit 5c3484
      ulimb = (ulimb << GMP_NUMB_BITS);
Packit 5c3484
      if (usize != 0) ulimb |= up[--usize];
Packit 5c3484
    }
Packit 5c3484
#endif
Packit 5c3484
Packit 5c3484
  /* 3. Compare the most significant mantissa limb with V.  */
Packit 5c3484
  if (ulimb != vval)
Packit 5c3484
    return (ulimb < vval) ? -1 : 1;
Packit 5c3484
Packit 5c3484
  /* Ignore zeroes at the low end of U.  */
Packit 5c3484
  for (; *up == 0; ++up)
Packit 5c3484
    --usize;
Packit 5c3484
Packit 5c3484
  /* 4. Now, if the number of limbs are different, we have a difference
Packit 5c3484
     since we have made sure the trailing limbs are not zero.  */
Packit 5c3484
  return (usize > 0);
Packit 5c3484
}