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      1 /* mpn_add_n -- Add equal length limb vectors.
      2 
      3 Copyright 1992-1994, 1996, 2000, 2002, 2009 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 either:
      9 
     10   * the GNU Lesser General Public License as published by the Free
     11     Software Foundation; either version 3 of the License, or (at your
     12     option) any later version.
     13 
     14 or
     15 
     16   * the GNU General Public License as published by the Free Software
     17     Foundation; either version 2 of the License, or (at your option) any
     18     later version.
     19 
     20 or both in parallel, as here.
     21 
     22 The GNU MP Library is distributed in the hope that it will be useful, but
     23 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
     24 or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
     25 for more details.
     26 
     27 You should have received copies of the GNU General Public License and the
     28 GNU Lesser General Public License along with the GNU MP Library.  If not,
     29 see https://www.gnu.org/licenses/.  */
     30 
     31 #include "gmp-impl.h"
     32 
     33 
     34 #if GMP_NAIL_BITS == 0
     35 
     36 mp_limb_t
     37 mpn_add_n (mp_ptr rp, mp_srcptr up, mp_srcptr vp, mp_size_t n)
     38 {
     39   mp_limb_t ul, vl, sl, rl, cy, cy1, cy2;
     40 
     41   ASSERT (n >= 1);
     42   ASSERT (MPN_SAME_OR_INCR_P (rp, up, n));
     43   ASSERT (MPN_SAME_OR_INCR_P (rp, vp, n));
     44 
     45   cy = 0;
     46   do
     47     {
     48       ul = *up++;
     49       vl = *vp++;
     50       sl = ul + vl;
     51       cy1 = sl < ul;
     52       rl = sl + cy;
     53       cy2 = rl < sl;
     54       cy = cy1 | cy2;
     55       *rp++ = rl;
     56     }
     57   while (--n != 0);
     58 
     59   return cy;
     60 }
     61 
     62 #endif
     63 
     64 #if GMP_NAIL_BITS >= 1
     65 
     66 mp_limb_t
     67 mpn_add_n (mp_ptr rp, mp_srcptr up, mp_srcptr vp, mp_size_t n)
     68 {
     69   mp_limb_t ul, vl, rl, cy;
     70 
     71   ASSERT (n >= 1);
     72   ASSERT (MPN_SAME_OR_INCR_P (rp, up, n));
     73   ASSERT (MPN_SAME_OR_INCR_P (rp, vp, n));
     74 
     75   cy = 0;
     76   do
     77     {
     78       ul = *up++;
     79       vl = *vp++;
     80       rl = ul + vl + cy;
     81       cy = rl >> GMP_NUMB_BITS;
     82       *rp++ = rl & GMP_NUMB_MASK;
     83     }
     84   while (--n != 0);
     85 
     86   return cy;
     87 }
     88 
     89 #endif
     90