sysdeps/generic/add_1.c

   1 /* mpn_add_1 --
   2
   3 Copyright (C) 1993, 1994 Free Software Foundation, Inc.
   4
   5 This file is part of the GNU MP Library.
   6
   7 The GNU MP Library is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU Library General Public License as published by
   9 the Free Software Foundation; either version 2 of the License, or (at your
  10 option) any later version.
  11
  12 The GNU MP Library is distributed in the hope that it will be useful, but
  13 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  14 or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
  15 License for more details.
  16
  17 You should have received a copy of the GNU Library General Public License
  18 along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
  19 the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
  20
  21 #define __mpn_add_1 __noname
  22 #include "gmp.h"
  23 #undef __mpn_add_1
  24
  25 #include "gmp-impl.h"
  26
  27 mp_limb
  28 __mpn_add_1 (res_ptr, s1_ptr, s1_size, s2_limb)
  29      register mp_ptr res_ptr;
  30      register mp_srcptr s1_ptr;
  31      register mp_size_t s1_size;
  32      register mp_limb s2_limb;
  33 {
  34   register mp_limb x;
  35
  36   x = *s1_ptr++;
  37   s2_limb = x + s2_limb;
  38   *res_ptr++ = s2_limb;
  39   if (s2_limb < x)
  40     {
  41       while (--s1_size != 0)
  42         {
  43           x = *s1_ptr++ + 1;
  44           *res_ptr++ = x;
  45           if (x != 0)
  46             goto fin;
  47         }
  48
  49       return 1;
  50     }
  51
  52  fin:
  53   if (res_ptr != s1_ptr)
  54     {
  55       mp_size_t i;
  56       for (i = 0; i < s1_size - 1; i++)
  57         res_ptr[i] = s1_ptr[i];
  58     }
  59
  60   return 0;
  61 }