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Diffstat (limited to 'mpi/mpih-shift.c')
-rw-r--r-- | mpi/mpih-shift.c | 94 |
1 files changed, 0 insertions, 94 deletions
diff --git a/mpi/mpih-shift.c b/mpi/mpih-shift.c deleted file mode 100644 index a8fe26aa2..000000000 --- a/mpi/mpih-shift.c +++ /dev/null @@ -1,94 +0,0 @@ -/* mpihelp-shift.c - MPI helper functions - * Copyright (c) 1997 by Werner Koch (dd9jn) - * - * This file is part of G10. - * - * G10 is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * G10 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 General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA - */ - -#include <config.h> -#include <stdio.h> -#include <stdlib.h> -#include "mpi-internal.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. - */ - -mpi_limb_t -mpihelp_lshift( mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize, - unsigned int cnt) -{ - mpi_limb_t high_limb, low_limb; - unsigned sh_1, sh_2; - mpi_size_t i; - mpi_limb_t retval; - - sh_1 = cnt; - wp += 1; - sh_2 = BITS_PER_MPI_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; -} - - -/* 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. - */ - -mpi_limb_t -mpihelp_rshift( mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize, unsigned cnt) -{ - mpi_limb_t high_limb, low_limb; - unsigned sh_1, sh_2; - mpi_size_t i; - mpi_limb_t retval; - - sh_1 = cnt; - wp -= 1; - sh_2 = BITS_PER_MPI_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; -} - |