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

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

diff --git a/ghc/runtime/gmp/mpz_add.c b/ghc/runtime/gmp/mpz_add.c
new file mode 100644 (file)
index 0000000..52639cc
--- /dev/null
+++ b/ghc/runtime/gmp/mpz_add.c
@@ -0,0 +1,121 @@
+/* mpz_add -- Add two integers.
+
+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"
+
+#ifndef BERKELEY_MP
+void
+#ifdef __STDC__
+mpz_add (MP_INT *sum, const MP_INT *u, const MP_INT *v)
+#else
+mpz_add (sum, u, v)
+     MP_INT *sum;
+     const MP_INT *u;
+     const MP_INT *v;
+#endif
+#else /* BERKELEY_MP */
+void
+#ifdef __STDC__
+madd (const MP_INT *u, const MP_INT *v, MP_INT *sum)
+#else
+madd (u, v, sum)
+     const MP_INT *u;
+     const MP_INT *v;
+     MP_INT *sum;
+#endif
+#endif /* BERKELEY_MP */
+{
+  mp_srcptr up, vp;
+  mp_ptr sump;
+  mp_size usize, vsize, sumsize;
+  mp_size abs_usize;
+  mp_size abs_vsize;
+
+  usize = u->size;
+  vsize = v->size;
+  abs_usize = ABS (usize);
+  abs_vsize = ABS (vsize);
+
+  if (abs_usize < abs_vsize)
+    {
+      /* Swap U and V. */
+      {const MP_INT *t = u; u = v; v = t;}
+      {mp_size t = usize; usize = vsize; vsize = t;}
+      {mp_size t = abs_usize; abs_usize = abs_vsize; abs_vsize = t;}
+    }
+
+  /* True: abs(USIZE) >= abs(VSIZE) */
+
+  /* If not space for sum (and possible carry), increase space.  */
+  sumsize = abs_usize + 1;
+  if (sum->alloc < sumsize)
+    _mpz_realloc (sum, sumsize);
+
+  /* These must be after realloc (u or v may be the same as sum).  */
+  up = u->d;
+  vp = v->d;
+  sump = sum->d;
+
+  if (usize >= 0)
+    {
+      if (vsize >= 0)
+       {
+         sumsize = mpn_add (sump, up, abs_usize, vp, abs_vsize);
+         if (sumsize != 0)
+           sump[abs_usize] = 1;
+         sumsize = sumsize + abs_usize;
+       }
+      else
+       {
+         /* The signs are different.  Need exact comparision to determine
+            which operand to subtract from which.  */
+         if (abs_usize == abs_vsize && mpn_cmp (up, vp, abs_usize) < 0)
+           sumsize = -(abs_usize
+                       + mpn_sub (sump, vp, abs_usize, up, abs_usize));
+         else
+           sumsize = (abs_usize
+                      + mpn_sub (sump, up, abs_usize, vp, abs_vsize));
+       }
+    }
+  else
+    {
+      if (vsize >= 0)
+       {
+         /* The signs are different.  Need exact comparision to determine
+            which operand to subtract from which.  */
+         if (abs_usize == abs_vsize && mpn_cmp (up, vp, abs_usize) < 0)
+           sumsize = (abs_usize
+                      + mpn_sub (sump, vp, abs_usize, up, abs_usize));
+         else
+           sumsize = -(abs_usize
+                       + mpn_sub (sump, up, abs_usize, vp, abs_vsize));
+       }
+      else
+       {
+         sumsize = mpn_add (sump, up, abs_usize, vp, abs_vsize);
+         if (sumsize != 0)
+           sump[abs_usize] = 1;
+         sumsize = -(sumsize + abs_usize);
+       }
+    }
+
+  sum->size = sumsize;
+}