/* mpn_lshift -- Shift left low level. 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 modifyit under the terms of the GNU Lesser General Public License as published bythe Free Software Foundation; either version 2.1 of the License, or (at youroption) any later version. The GNU MP Library is distributed in the hope that it will be useful, butWITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITYor FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General PublicLicense for more details. You should have received a copy of the GNU Lesser General Public Licensealong with the GNU MP Library; see the file COPYING.LIB.  If not, write tothe Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,MA 02111-1307, USA. */ #include <config.h>#include "gmp-impl.h" /* Shift U (pointed to by UP and USIZE digits long) CNT bits to the left   and store the USIZE least significant digits of the result at WP.   Return the bits shifted out from the most significant digit.    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_lshift (register mp_ptr wp,	    register mp_srcptr up, mp_size_t usize,	    register unsigned int cnt)#elsempn_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;  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 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;  sh_2 = BITS_PER_MP_LIMB - sh_1;  i = usize - 1;  low_limb = up[i];  retval = low_limb >> sh_2;  high_limb = low_limb;  while (--i >= 0)    {      low_limb = up[i];      wp[i] = (high_limb << sh_1) | (low_limb >> sh_2);      high_limb = low_limb;    }  wp[i] = high_limb << sh_1;   return retval;}