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Diff for /OpenXM_contrib/gmp/mpn/generic/Attic/lshift.c between version 1.1 and 1.1.1.3

version 1.1, 2000/01/10 15:35:23

version 1.1.1.3, 2003/08/25 16:06:20

Line 1

/* mpn_lshift -- Shift left low level.

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 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:

1. 0 < CNT < BITS_PER_MP_LIMB

1. 0 < cnt < GMP_NUMB_BITS.

2. If the result is to be written over the input, WP must be >= UP.

2. 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,

#else

mpn_lshift (wp, up, usize, cnt)

mp_size_t usize;

#endif

{

mp_limb_t high_limb, low_limb;

unsigned int tnc;

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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