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

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

diff --git a/ghc/runtime/gmp/mpz_mul.c b/ghc/runtime/gmp/mpz_mul.c
new file mode 100644 (file)
index 0000000..7bb2b90
--- /dev/null
+++ b/ghc/runtime/gmp/mpz_mul.c
@@ -0,0 +1,114 @@
+/* mpz_mul -- Multiply 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_mul (MP_INT *w, const MP_INT *u, const MP_INT *v)
+#else
+mpz_mul (w, u, v)
+     MP_INT *w;
+     const MP_INT *u;
+     const MP_INT *v;
+#endif
+#else /* BERKELEY_MP */
+void
+#ifdef __STDC__
+mult (const MP_INT *u, const MP_INT *v, MP_INT *w)
+#else
+mult (u, v, w)
+     const MP_INT *u;
+     const MP_INT *v;
+     MP_INT *w;
+#endif
+#endif /* BERKELEY_MP */
+{
+  mp_size usize = u->size;
+  mp_size vsize = v->size;
+  mp_size wsize;
+  mp_size sign_product;
+  mp_ptr up, vp;
+  mp_ptr wp;
+  mp_ptr free_me = NULL;
+  size_t free_me_size;
+
+  sign_product = usize ^ vsize;
+  usize = ABS (usize);
+  vsize = ABS (vsize);
+
+  if (usize < vsize)
+    {
+      /* Swap U and V.  */
+      {const MP_INT *t = u; u = v; v = t;}
+      {mp_size t = usize; usize = vsize; vsize = t;}
+    }
+
+  up = u->d;
+  vp = v->d;
+  wp = w->d;
+
+  /* Ensure W has space enough to store the result.  */
+  wsize = usize + vsize;
+  if (w->alloc < wsize)
+    {
+      if (wp == up || wp == vp)
+       {
+         free_me = wp;
+         free_me_size = w->alloc;
+       }
+      else
+       (*_mp_free_func) (wp, w->alloc * BYTES_PER_MP_LIMB);
+
+      w->alloc = wsize;
+      wp = (mp_ptr) (*_mp_allocate_func) (wsize * BYTES_PER_MP_LIMB);
+      w->d = wp;
+    }
+  else
+    {
+      /* Make U and V not overlap with W.  */
+      if (wp == up)
+       {
+         /* W and U are identical.  Allocate temporary space for U.  */
+         up = (mp_ptr) alloca (usize * BYTES_PER_MP_LIMB);
+         /* Is V identical too?  Keep it identical with U.  */
+         if (wp == vp)
+           vp = up;
+         /* Copy to the temporary space.  */
+         MPN_COPY (up, wp, usize);
+       }
+      else if (wp == vp)
+       {
+         /* W and V are identical.  Allocate temporary space for V.  */
+         vp = (mp_ptr) alloca (vsize * BYTES_PER_MP_LIMB);
+         /* Copy to the temporary space.  */
+         MPN_COPY (vp, wp, vsize);
+       }
+    }
+
+  wsize = mpn_mul (wp, up, usize, vp, vsize);
+  w->size = sign_product < 0 ? -wsize : wsize;
+  if (free_me != NULL)
+    (*_mp_free_func) (free_me, free_me_size * BYTES_PER_MP_LIMB);
+
+  alloca (0);
+}