ch1_mpi 1
ch1_mpi 2 * Modified by No Such Labs. (C) 2015. See README.
ch1_mpi 3 *
ch1_mpi 4 * This file was originally part of Gnu Privacy Guard (GPG), ver. 1.4.10,
ch1_mpi 5 * SHA256(gnupg-1.4.10.tar.gz):
ch1_mpi 6 * 0bfd74660a2f6cedcf7d8256db4a63c996ffebbcdc2cf54397bfb72878c5a85a
ch1_mpi 7 * (C) 1994-2005 Free Software Foundation, Inc.
ch1_mpi 8 *
ch1_mpi 9 * This program is free software: you can redistribute it and/or modify
ch1_mpi 10 * it under the terms of the GNU General Public License as published by
ch1_mpi 11 * the Free Software Foundation, either version 3 of the License, or
ch1_mpi 12 * (at your option) any later version.
ch1_mpi 13 *
ch1_mpi 14 * This program is distributed in the hope that it will be useful,
ch1_mpi 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
ch1_mpi 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
ch1_mpi 17 * GNU General Public License for more details.
ch1_mpi 18 *
ch1_mpi 19 * You should have received a copy of the GNU General Public License
ch1_mpi 20 * along with this program. If not, see <http:
ch1_mpi 21 */
ch1_mpi 22
ch1_mpi 23 #include <stdio.h>
ch1_mpi 24 #include <stdlib.h>
ch1_mpi 25
ch1_mpi 26 #include "knobs.h"
ch1_mpi 27 #include "mpi-internal.h"
ch1_mpi 28
ch1_mpi 29
ch1_mpi 30
ch1_mpi 31 * and store the USIZE least significant limbs of the result at WP.
ch1_mpi 32 * The bits shifted out to the right are returned.
ch1_mpi 33 *
ch1_mpi 34 * Argument constraints:
ch1_mpi 35 * 1. 0 < CNT < BITS_PER_MP_LIMB
ch1_mpi 36 * 2. If the result is to be written over the input, WP must be <= UP.
ch1_mpi 37 */
ch1_mpi 38
ch1_mpi 39 mpi_limb_t
ch1_mpi 40 mpihelp_rshift( mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize, unsigned cnt)
ch1_mpi 41 {
ch1_mpi 42 mpi_limb_t high_limb, low_limb;
ch1_mpi 43 unsigned sh_1, sh_2;
ch1_mpi 44 mpi_size_t i;
ch1_mpi 45 mpi_limb_t retval;
ch1_mpi 46
ch1_mpi 47 sh_1 = cnt;
ch1_mpi 48 wp -= 1;
ch1_mpi 49 sh_2 = BITS_PER_MPI_LIMB - sh_1;
ch1_mpi 50 high_limb = up[0];
ch1_mpi 51 retval = high_limb << sh_2;
ch1_mpi 52 low_limb = high_limb;
ch1_mpi 53 for( i=1; i < usize; i++) {
ch1_mpi 54 high_limb = up[i];
ch1_mpi 55 wp[i] = (low_limb >> sh_1) | (high_limb << sh_2);
ch1_mpi 56 low_limb = high_limb;
ch1_mpi 57 }
ch1_mpi 58 wp[i] = low_limb >> sh_1;
ch1_mpi 59
ch1_mpi 60 return retval;
ch1_mpi 61 }
ch1_mpi 62