summaryrefslogtreecommitdiff
path: root/ghc/runtime/gmp/mpz_add.c
diff options
context:
space:
mode:
Diffstat (limited to 'ghc/runtime/gmp/mpz_add.c')
-rw-r--r--ghc/runtime/gmp/mpz_add.c121
1 files changed, 121 insertions, 0 deletions
diff --git a/ghc/runtime/gmp/mpz_add.c b/ghc/runtime/gmp/mpz_add.c
new file mode 100644
index 0000000000..52639cc99f
--- /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;
+}