[project @ 1996-01-08 20:28:12 by partain]

[ghc-hetmet.git] / ghc / runtime / gmp / mpz_add_ui.c

diff --git a/ghc/runtime/gmp/mpz_add_ui.c b/ghc/runtime/gmp/mpz_add_ui.c
new file mode 100644 (file)
index 0000000..34f754b
--- /dev/null
+++ b/ghc/runtime/gmp/mpz_add_ui.c
@@ -0,0 +1,84 @@
+/* mpz_add_ui -- Add an MP_INT and an unsigned one-word integer.
+
+Copyright (C) 1991 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 General Public License as published by
+the Free Software Foundation; either version 2, 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 General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with the GNU MP Library; see the file COPYING.  If not, write to
+the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+#include "gmp.h"
+#include "gmp-impl.h"
+
+void
+#ifdef __STDC__
+mpz_add_ui (MP_INT *sum, const MP_INT *add1, mp_limb add2)
+#else
+mpz_add_ui (sum, add1, add2)
+     MP_INT *sum;
+     const MP_INT *add1;
+     mp_limb add2;
+#endif
+{
+  mp_srcptr add1p;
+  mp_ptr sump;
+  mp_size add1size, sumsize;
+  mp_size abs_add1size;
+
+  add1size = add1->size;
+  abs_add1size = ABS (add1size);
+
+  /* If not space for SUM (and possible carry), increase space.  */
+  sumsize = abs_add1size + 1;
+  if (sum->alloc < sumsize)
+    _mpz_realloc (sum, sumsize);
+
+  /* These must be after realloc (ADD1 may be the same as SUM).  */
+  add1p = add1->d;
+  sump = sum->d;
+
+  if (add2 == 0)
+    {
+      MPN_COPY (sump, add1p, abs_add1size);
+      sum->size = add1size;
+      return;
+    }
+  if (abs_add1size == 0)
+    {
+      sump[0] = add2;
+      sum->size = 1;
+      return;
+    }
+
+  if (add1size >= 0)
+    {
+      sumsize = mpn_add (sump, add1p, abs_add1size, &add2, 1);
+      if (sumsize != 0)
+       sump[abs_add1size] = 1;
+      sumsize = sumsize + abs_add1size;
+    }
+  else
+    {
+      /* The signs are different.  Need exact comparision to determine
+        which operand to subtract from which.  */
+      if (abs_add1size == 1 && add1p[0] < add2)
+       sumsize = (abs_add1size
+                  + mpn_sub (sump, &add2, 1, add1p, 1));
+      else
+       sumsize = -(abs_add1size
+                   + mpn_sub (sump, add1p, abs_add1size, &add2, 1));
+    }
+
+  sum->size = sumsize;
+}