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authorSimon Marlow <simonmar@microsoft.com>2006-04-07 02:05:11 +0000
committerSimon Marlow <simonmar@microsoft.com>2006-04-07 02:05:11 +0000
commit0065d5ab628975892cea1ec7303f968c3338cbe1 (patch)
tree8e2afe0ab48ee33cf95009809d67c9649573ef92 /rts/gmp/mpn/generic/rshift.c
parent28a464a75e14cece5db40f2765a29348273ff2d2 (diff)
downloadhaskell-0065d5ab628975892cea1ec7303f968c3338cbe1.tar.gz
Reorganisation of the source tree
Most of the other users of the fptools build system have migrated to Cabal, and with the move to darcs we can now flatten the source tree without losing history, so here goes. The main change is that the ghc/ subdir is gone, and most of what it contained is now at the top level. The build system now makes no pretense at being multi-project, it is just the GHC build system. No doubt this will break many things, and there will be a period of instability while we fix the dependencies. A straightforward build should work, but I haven't yet fixed binary/source distributions. Changes to the Building Guide will follow, too.
Diffstat (limited to 'rts/gmp/mpn/generic/rshift.c')
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1 files changed, 88 insertions, 0 deletions
diff --git a/rts/gmp/mpn/generic/rshift.c b/rts/gmp/mpn/generic/rshift.c
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+/* mpn_rshift -- Shift right a low-level natural-number integer.
+
+Copyright (C) 1991, 1993, 1994, 1996 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 Lesser General Public License as published by
+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 Lesser General Public
+License for more details.
+
+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. */
+
+#include "gmp.h"
+#include "gmp-impl.h"
+
+/* Shift U (pointed to by UP and USIZE limbs long) CNT bits to the right
+ and store the USIZE least significant limbs of the result at WP.
+ The bits shifted out to the right are returned.
+
+ Argument constraints:
+ 1. 0 < CNT < BITS_PER_MP_LIMB
+ 2. If the result is to be written over the input, WP must be <= UP.
+*/
+
+mp_limb_t
+#if __STDC__
+mpn_rshift (register mp_ptr wp,
+ register mp_srcptr up, mp_size_t usize,
+ register unsigned int cnt)
+#else
+mpn_rshift (wp, up, usize, cnt)
+ register mp_ptr wp;
+ register mp_srcptr up;
+ mp_size_t usize;
+ register unsigned int cnt;
+#endif
+{
+ register mp_limb_t high_limb, low_limb;
+ register unsigned sh_1, sh_2;
+ register mp_size_t i;
+ mp_limb_t retval;
+
+#ifdef DEBUG
+ if (usize == 0 || cnt == 0)
+ abort ();
+#endif
+
+ sh_1 = cnt;
+
+#if 0
+ if (sh_1 == 0)
+ {
+ if (wp != up)
+ {
+ /* Copy from low end to high end, to allow specified input/output
+ overlapping. */
+ for (i = 0; i < usize; i++)
+ wp[i] = up[i];
+ }
+ return usize;
+ }
+#endif
+
+ wp -= 1;
+ sh_2 = BITS_PER_MP_LIMB - sh_1;
+ high_limb = up[0];
+ retval = high_limb << sh_2;
+ low_limb = high_limb;
+
+ for (i = 1; i < usize; i++)
+ {
+ high_limb = up[i];
+ wp[i] = (low_limb >> sh_1) | (high_limb << sh_2);
+ low_limb = high_limb;
+ }
+ wp[i] = low_limb >> sh_1;
+
+ return retval;
+}