[project @ 1998-06-05 14:38:04 by simonm]

[ghc-hetmet.git] / ghc / rts / gmp / mpz / set_d.c

diff --git a/ghc/rts/gmp/mpz/set_d.c b/ghc/rts/gmp/mpz/set_d.c
new file mode 100644 (file)
index 0000000..c09b1d9
--- /dev/null
+++ b/ghc/rts/gmp/mpz/set_d.c
@@ -0,0 +1,93 @@
+/* mpz_set_d(integer, val) -- Assign INTEGER with a double value VAL.
+
+Copyright (C) 1995 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_set_d (mpz_ptr r, double d)
+#else
+mpz_set_d (r, d)
+     mpz_ptr r;
+     double d;
+#endif
+{
+  int negative;
+  mp_size_t size;
+  mp_limb_t tp[3];
+  mp_ptr rp;
+
+  negative = d < 0;
+  d = ABS (d);
+
+  /* Handle small arguments quickly.  */
+  if (d < MP_BASE_AS_DOUBLE)
+    {
+      mp_limb_t tmp;
+      tmp = d;
+      PTR(r)[0] = tmp;
+      SIZ(r) = negative ? -(tmp != 0) : (tmp != 0);
+      return;
+    }
+
+  size = __gmp_extract_double (tp, d);
+
+  if (ALLOC(r) < size)
+    _mpz_realloc (r, size);
+
+  rp = PTR (r);
+
+#if BITS_PER_MP_LIMB == 32
+  switch (size)
+    {
+    default:
+      MPN_ZERO (rp, size - 3);
+      rp += size - 3;
+    case 3:
+      rp[2] = tp[2];
+      rp[1] = tp[1];
+      rp[0] = tp[0];
+      break;
+    case 2:
+      rp[1] = tp[2];
+      rp[0] = tp[1];
+      break;
+    case 1:
+      abort ();
+    }
+#else
+  switch (size)
+    {
+    default:
+      MPN_ZERO (rp, size - 2);
+      rp += size - 2;
+    case 2:
+      rp[1] = tp[1];
+      rp[0] = tp[0];
+      break;
+    case 1:
+      abort ();
+    }
+#endif
+
+  SIZ(r) = negative ? -size : size;
+}