github.com/aergoio/aergo@v1.3.1/libtool/src/gmp-6.1.2/mpz/cmp_si.c (about)

     1  /* mpz_cmp_si(u,v) -- Compare an integer U with a single-word int V.
     2     Return positive, zero, or negative based on if U > V, U == V, or U < V.
     3  
     4  Copyright 1991, 1993-1996, 2000-2002, 2012, 2013 Free Software Foundation, Inc.
     5  
     6  This file is part of the GNU MP Library.
     7  
     8  The GNU MP Library is free software; you can redistribute it and/or modify
     9  it under the terms of either:
    10  
    11    * the GNU Lesser General Public License as published by the Free
    12      Software Foundation; either version 3 of the License, or (at your
    13      option) any later version.
    14  
    15  or
    16  
    17    * the GNU General Public License as published by the Free Software
    18      Foundation; either version 2 of the License, or (at your option) any
    19      later version.
    20  
    21  or both in parallel, as here.
    22  
    23  The GNU MP Library is distributed in the hope that it will be useful, but
    24  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
    25  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    26  for more details.
    27  
    28  You should have received copies of the GNU General Public License and the
    29  GNU Lesser General Public License along with the GNU MP Library.  If not,
    30  see https://www.gnu.org/licenses/.  */
    31  
    32  #include "gmp.h"
    33  #include "gmp-impl.h"
    34  
    35  int
    36  _mpz_cmp_si (mpz_srcptr u, signed long int v_digit) __GMP_NOTHROW
    37  {
    38  #if GMP_NAIL_BITS != 0
    39    /* FIXME.  This isn't very pretty.  */
    40    mpz_t tmp;
    41    mp_limb_t tt[2];
    42    PTR(tmp) = tt;
    43    ALLOC(tmp) = 2;
    44    mpz_set_si (tmp, v_digit);
    45    return mpz_cmp (u, tmp);
    46  #else
    47  
    48    mp_size_t vsize, usize;
    49  
    50    usize = SIZ (u);
    51    vsize = (v_digit > 0) - (v_digit < 0);
    52  
    53    if ((usize == 0) | (usize != vsize))
    54      return usize - vsize;
    55    else {
    56      mp_limb_t u_digit, absv_digit;
    57  
    58      u_digit = PTR (u)[0];
    59      absv_digit = ABS_CAST (unsigned long, v_digit);
    60  
    61      if (u_digit == absv_digit)
    62        return 0;
    63  
    64      if (u_digit > absv_digit)
    65        return usize;
    66      else
    67        return -usize;
    68    }
    69  #endif
    70  }