63 lines
1.8 KiB
C
63 lines
1.8 KiB
C
/* mpn_add_n -- Add two limb vectors of equal, non-zero length.
|
|
|
|
Copyright (C) 1992, 1993, 1994, 1996 Free Software Foundation, Inc.
|
|
|
|
This file is part of the GNU MP Library.
|
|
|
|
The GNU MP Library is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU Library General Public License as published by
|
|
the Free Software Foundation; either version 2 of the License, or (at your
|
|
option) any later version.
|
|
|
|
The GNU MP Library is distributed in the hope that it will be useful, but
|
|
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
|
|
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
|
|
License for more details.
|
|
|
|
You should have received a copy of the GNU Library General Public License
|
|
along with the GNU MP Library; see the file COPYING.LIB. If not, write to
|
|
the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
|
|
MA 02111-1307, USA. */
|
|
|
|
#include "gmp.h"
|
|
#include "gmp-impl.h"
|
|
|
|
mp_limb_t
|
|
#if __STDC__
|
|
mpn_add_n (mp_ptr res_ptr, mp_srcptr s1_ptr, mp_srcptr s2_ptr, mp_size_t size)
|
|
#else
|
|
mpn_add_n (res_ptr, s1_ptr, s2_ptr, size)
|
|
register mp_ptr res_ptr;
|
|
register mp_srcptr s1_ptr;
|
|
register mp_srcptr s2_ptr;
|
|
mp_size_t size;
|
|
#endif
|
|
{
|
|
register mp_limb_t x, y, cy;
|
|
register mp_size_t j;
|
|
|
|
/* The loop counter and index J goes from -SIZE to -1. This way
|
|
the loop becomes faster. */
|
|
j = -size;
|
|
|
|
/* Offset the base pointers to compensate for the negative indices. */
|
|
s1_ptr -= j;
|
|
s2_ptr -= j;
|
|
res_ptr -= j;
|
|
|
|
cy = 0;
|
|
do
|
|
{
|
|
y = s2_ptr[j];
|
|
x = s1_ptr[j];
|
|
y += cy; /* add previous carry to one addend */
|
|
cy = (y < cy); /* get out carry from that addition */
|
|
y = x + y; /* add other addend */
|
|
cy = (y < x) + cy; /* get out carry from that add, combine */
|
|
res_ptr[j] = y;
|
|
}
|
|
while (++j != 0);
|
|
|
|
return cy;
|
|
}
|