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-rw-r--r--contrib/libgmp/mpz/add.c120
1 files changed, 120 insertions, 0 deletions
diff --git a/contrib/libgmp/mpz/add.c b/contrib/libgmp/mpz/add.c
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+/* mpz_add -- Add two integers.
+
+Copyright (C) 1991, 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"
+
+#ifndef BERKELEY_MP
+void
+#if __STDC__
+mpz_add (mpz_ptr w, mpz_srcptr u, mpz_srcptr v)
+#else
+mpz_add (w, u, v)
+ mpz_ptr w;
+ mpz_srcptr u;
+ mpz_srcptr v;
+#endif
+#else /* BERKELEY_MP */
+void
+#if __STDC__
+madd (mpz_srcptr u, mpz_srcptr v, mpz_ptr w)
+#else
+madd (u, v, w)
+ mpz_srcptr u;
+ mpz_srcptr v;
+ mpz_ptr w;
+#endif
+#endif /* BERKELEY_MP */
+{
+ mp_srcptr up, vp;
+ mp_ptr wp;
+ mp_size_t usize, vsize, wsize;
+ mp_size_t abs_usize;
+ mp_size_t abs_vsize;
+
+ usize = u->_mp_size;
+ vsize = v->_mp_size;
+ abs_usize = ABS (usize);
+ abs_vsize = ABS (vsize);
+
+ if (abs_usize < abs_vsize)
+ {
+ /* Swap U and V. */
+ {const __mpz_struct *t = u; u = v; v = t;}
+ {mp_size_t t = usize; usize = vsize; vsize = t;}
+ {mp_size_t t = abs_usize; abs_usize = abs_vsize; abs_vsize = t;}
+ }
+
+ /* True: ABS_USIZE >= ABS_VSIZE. */
+
+ /* If not space for w (and possible carry), increase space. */
+ wsize = abs_usize + 1;
+ if (w->_mp_alloc < wsize)
+ _mpz_realloc (w, wsize);
+
+ /* These must be after realloc (u or v may be the same as w). */
+ up = u->_mp_d;
+ vp = v->_mp_d;
+ wp = w->_mp_d;
+
+ if ((usize ^ vsize) < 0)
+ {
+ /* U and V have different sign. Need to compare them to determine
+ which operand to subtract from which. */
+
+ /* This test is right since ABS_USIZE >= ABS_VSIZE. */
+ if (abs_usize != abs_vsize)
+ {
+ mpn_sub (wp, up, abs_usize, vp, abs_vsize);
+ wsize = abs_usize;
+ MPN_NORMALIZE (wp, wsize);
+ if (usize < 0)
+ wsize = -wsize;
+ }
+ else if (mpn_cmp (up, vp, abs_usize) < 0)
+ {
+ mpn_sub_n (wp, vp, up, abs_usize);
+ wsize = abs_usize;
+ MPN_NORMALIZE (wp, wsize);
+ if (usize >= 0)
+ wsize = -wsize;
+ }
+ else
+ {
+ mpn_sub_n (wp, up, vp, abs_usize);
+ wsize = abs_usize;
+ MPN_NORMALIZE (wp, wsize);
+ if (usize < 0)
+ wsize = -wsize;
+ }
+ }
+ else
+ {
+ /* U and V have same sign. Add them. */
+ mp_limb_t cy_limb = mpn_add (wp, up, abs_usize, vp, abs_vsize);
+ wp[abs_usize] = cy_limb;
+ wsize = abs_usize + cy_limb;
+ if (usize < 0)
+ wsize = -wsize;
+ }
+
+ w->_mp_size = wsize;
+}
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