OpenXM_contrib/gmp/mpn/generic/lshift.c - diff

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Diff for /OpenXM_contrib/gmp/mpn/generic/Attic/lshift.c between version 1.1.1.2 and 1.1.1.3

-version 1.1.1.2, 2000/09/09 14:12:25
+version 1.1.1.3, 2003/08/25 16:06:20
 Line 1
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  /* mpn_lshift -- Shift left low level.
- Copyright (C) 1991, 1993, 1994, 1996 Free Software Foundation, Inc.
+ Copyright 1991, 1993, 1994, 1996, 2000, 2001, 2002 Free Software Foundation,
+ Inc.
  This file is part of the GNU MP Library.
-Line 22  MA 02111-1307, USA. */
+Line 23  MA 02111-1307, USA. */
 Line 22  MA 02111-1307, USA. */
 Line 23  MA 02111-1307, USA. */
  #include "gmp.h"
  #include "gmp-impl.h"
- /* Shift U (pointed to by UP and USIZE digits long) CNT bits to the left
+ /* Shift U (pointed to by up and n limbs long) cnt bits to the left
-    and store the USIZE least significant digits of the result at WP.
+    and store the n least significant limbs of the result at rp.
-    Return the bits shifted out from the most significant digit.
+    Return the bits shifted out from the most significant limb.
     Argument constraints:
-. 0 < CNT < BITS_PER_MP_LIMB
+. 0 < cnt < GMP_NUMB_BITS.
-. If the result is to be written over the input, WP must be >= UP.
+. If the result is to be written over the input, rp must be >= up.
  */
  mp_limb_t
- #if __STDC__
+ mpn_lshift (mp_ptr rp, mp_srcptr up, mp_size_t n, unsigned int cnt)
- mpn_lshift (register mp_ptr wp,
-             register mp_srcptr up, mp_size_t usize,
-             register unsigned int cnt)
- #else
- mpn_lshift (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;
+   mp_limb_t high_limb, low_limb;
-   register unsigned sh_1, sh_2;
+   unsigned int tnc;
-   register mp_size_t i;
+   mp_size_t i;
    mp_limb_t retval;
- #ifdef DEBUG
+   ASSERT (n >= 1);
-   if (usize == 0 || cnt == 0)
+   ASSERT (cnt >= 1);
-     abort ();
+   ASSERT (cnt < GMP_NUMB_BITS);
- #endif
+   ASSERT (MPN_SAME_OR_DECR_P (rp, up, n));
-   sh_1 = cnt;
+   up += n;
- #if 0
+   rp += n;
-   if (sh_1 == 0)
-     {
-       if (wp != up)
-         {
-           /* Copy from high end to low end, to allow specified input/output
-              overlapping.  */
-           for (i = usize - 1; i >= 0; i--)
-             wp[i] = up[i];
-         }
-       return 0;
-     }
- #endif
-   wp += 1;
+   tnc = GMP_NUMB_BITS - cnt;
-   sh_2 = BITS_PER_MP_LIMB - sh_1;
+   low_limb = *--up;
-   i = usize - 1;
+   retval = low_limb >> tnc;
-   low_limb = up[i];
+   high_limb = (low_limb << cnt) & GMP_NUMB_MASK;
-   retval = low_limb >> sh_2;
-   high_limb = low_limb;
+   for (i = n - 1; i != 0; i--)
-   while (--i >= 0)
      {
-       low_limb = up[i];
+       low_limb = *--up;
-       wp[i] = (high_limb << sh_1) | (low_limb >> sh_2);
+       *--rp = high_limb | (low_limb >> tnc);
-       high_limb = low_limb;
+       high_limb = (low_limb << cnt) & GMP_NUMB_MASK;
      }
-   wp[i] = high_limb << sh_1;
+   *--rp = high_limb;
    return retval;
  }

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