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-rw-r--r--mpz/add_ui.c84
1 files changed, 84 insertions, 0 deletions
diff --git a/mpz/add_ui.c b/mpz/add_ui.c
new file mode 100644
index 000000000..a1e430631
--- /dev/null
+++ b/mpz/add_ui.c
@@ -0,0 +1,84 @@
+/* mpz_add_ui -- Add an mpz_t and an unsigned one-word integer.
+
+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"
+
+void
+#if __STDC__
+mpz_add_ui (mpz_ptr w, mpz_srcptr u, unsigned long int v)
+#else
+mpz_add_ui (w, u, v)
+ mpz_ptr w;
+ mpz_srcptr u;
+ unsigned long int v;
+#endif
+{
+ mp_srcptr up;
+ mp_ptr wp;
+ mp_size_t usize, wsize;
+ mp_size_t abs_usize;
+
+ usize = u->_mp_size;
+ abs_usize = ABS (usize);
+
+ /* 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 may be the same as W). */
+ up = u->_mp_d;
+ wp = w->_mp_d;
+
+ if (abs_usize == 0)
+ {
+ wp[0] = v;
+ w->_mp_size = v != 0;
+ return;
+ }
+
+ if (usize >= 0)
+ {
+ mp_limb_t cy;
+ cy = mpn_add_1 (wp, up, abs_usize, v);
+ wp[abs_usize] = cy;
+ wsize = abs_usize + cy;
+ }
+ else
+ {
+ /* The signs are different. Need exact comparison to determine
+ which operand to subtract from which. */
+ if (abs_usize == 1 && up[0] < v)
+ {
+ wp[0] = v - up[0];
+ wsize = 1;
+ }
+ else
+ {
+ mpn_sub_1 (wp, up, abs_usize, v);
+ /* Size can decrease with at most one limb. */
+ wsize = -(abs_usize - (wp[abs_usize - 1] == 0));
+ }
+ }
+
+ w->_mp_size = wsize;
+}