source/libs/gmp/gmp-src/mpz/cmpabs_ui.c

   1 /* mpz_cmpabs_ui.c -- Compare an mpz_t a with an mp_limb_t b.  Return positive,
   2   zero, or negative based on if a > b, a == b, or a < b.
   3
   4 Copyright 1991, 1993-1995, 1997, 2000-2002 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_cmpabs_ui (mpz_srcptr u, unsigned long int v_digit) __GMP_NOTHROW
  37 {
  38   mp_ptr up;
  39   mp_size_t un;
  40   mp_limb_t ul;
  41
  42   up = PTR(u);
  43   un = SIZ(u);
  44
  45   if (un == 0)
  46     return -(v_digit != 0);
  47
  48   un = ABS (un);
  49
  50   if (un == 1)
  51     {
  52       ul = up[0];
  53       if (ul > v_digit)
  54         return 1;
  55       if (ul < v_digit)
  56         return -1;
  57       return 0;
  58     }
  59
  60 #if GMP_NAIL_BITS != 0
  61   if (v_digit > GMP_NUMB_MAX)
  62     {
  63       if (un == 2)
  64         {
  65           ul = up[0] + (up[1] << GMP_NUMB_BITS);
  66
  67           if (ul > v_digit)
  68             return 1;
  69           if (ul < v_digit)
  70             return -1;
  71           return 0;
  72         }
  73     }
  74 #endif
  75
  76   return 1;
  77 }