OpenXM_contrib/gmp/mpf/set_prc.c - diff

Return to set_prc.c CVS log

Up to [local] / OpenXM_contrib / gmp / mpf

Diff for /OpenXM_contrib/gmp/mpf/Attic/set_prc.c between version 1.1.1.1 and 1.1.1.3

-version 1.1.1.1, 2000/01/10 15:35:22
+version 1.1.1.3, 2003/08/25 16:06:35
 Line 1
 Line 1
 Line 1
  /* mpf_set_prec(x) -- Change the precision of x.
- Copyright (C) 1993, 1994, 1995 Free Software Foundation, Inc.
+ Copyright 1993, 1994, 1995, 2000, 2001 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
+ it under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 2 of the License, or (at your
+ the Free Software Foundation; either version 2.1 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
+ or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  License for more details.
- You should have received a copy of the GNU Library General Public License
+ You should have received a copy of the GNU Lesser 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. */
 Line 22  MA 02111-1307, USA. */
 Line 22  MA 02111-1307, USA. */
 Line 22  MA 02111-1307, USA. */
  #include "gmp.h"
  #include "gmp-impl.h"
+ /* A full new_prec+1 limbs are always retained, even though just new_prec
+    would satisfy the requested precision.  If size==new_prec+1 then
+    certainly new_prec+1 should be kept since no copying is needed in that
+    case.  If just new_prec was kept for size>new_prec+1 it'd be a bit
+    inconsistent.  */
  void
- #if __STDC__
+ mpf_set_prec (mpf_ptr x, unsigned long int new_prec_in_bits)
- mpf_set_prec (mpf_ptr x, unsigned long int prec_in_bits)
- #else
- mpf_set_prec (x, prec_in_bits)
-      mpf_ptr x;
-      unsigned long int prec_in_bits;
- #endif
  {
-   mp_size_t prec;
+   mp_size_t  old_prec, new_prec, new_prec_plus1;
-   mp_size_t size = ABS (x->_mp_size);
+   mp_size_t  size, sign;
+   mp_ptr     xp;
-   prec = (MAX (53, prec_in_bits) + 2 * BITS_PER_MP_LIMB - 1)/BITS_PER_MP_LIMB;
+   new_prec = __GMPF_BITS_TO_PREC (new_prec_in_bits);
+   old_prec = PREC(x);
-   /* We want the most significant limbs, so move the limbs down if we are
+   /* do nothing if already the right precision */
-      about to truncate the value.  */
+   if (new_prec == old_prec)
-   if (size > prec + 1)
+     return;
-     {
-       mp_size_t offset = size - (prec + 1);
-       mp_ptr xp = x->_mp_d;
-       MPN_COPY (xp, xp + offset, prec + 1);
+   PREC(x) = new_prec;
+   new_prec_plus1 = new_prec + 1;
+   /* retain most significant limbs */
+   sign = SIZ(x);
+   size = ABS (sign);
+   xp = PTR(x);
+   if (size > new_prec_plus1)
+     {
+       SIZ(x) = (sign >= 0 ? new_prec_plus1 : -new_prec_plus1);
+       MPN_COPY_INCR (xp, xp + size - new_prec_plus1, new_prec_plus1);
      }
-   x->_mp_d = (mp_ptr) (*_mp_reallocate_func)
+   PTR(x) = __GMP_REALLOCATE_FUNC_LIMBS (xp, old_prec+1, new_prec_plus1);
-     (x->_mp_d,
-      (x->_mp_prec + 1) * BYTES_PER_MP_LIMB, (prec + 1) * BYTES_PER_MP_LIMB);
-   x->_mp_prec = prec;
-   /* If the precision decreased, truncate the number.  */
-   if (size > prec + 1)
-     x->_mp_size = x->_mp_size >= 0 ? (prec + 1) : -(prec + 1);
  }

FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>