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smg_comms_c_wrappers    1 /* mpihelp-add_2.c  -  MPI helper functions
smg_comms_c_wrappers    2  * Modified by No Such Labs. (C) 2015. See README.
smg_comms_c_wrappers    3  *
smg_comms_c_wrappers    4  * This file was originally part of Gnu Privacy Guard (GPG), ver. 1.4.10,
smg_comms_c_wrappers    5  * SHA256(gnupg-1.4.10.tar.gz):
smg_comms_c_wrappers    6  *        0bfd74660a2f6cedcf7d8256db4a63c996ffebbcdc2cf54397bfb72878c5a85a
smg_comms_c_wrappers    7  * (C) 1994-2005 Free Software Foundation, Inc.
smg_comms_c_wrappers    8  *
smg_comms_c_wrappers    9  * This program is free software: you can redistribute it and/or modify
smg_comms_c_wrappers   10  * it under the terms of the GNU General Public License as published by
smg_comms_c_wrappers   11  * the Free Software Foundation, either version 3 of the License, or
smg_comms_c_wrappers   12  * (at your option) any later version.
smg_comms_c_wrappers   13  *
smg_comms_c_wrappers   14  * This program is distributed in the hope that it will be useful,
smg_comms_c_wrappers   15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
smg_comms_c_wrappers   16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
smg_comms_c_wrappers   17  * GNU General Public License for more details.
smg_comms_c_wrappers   18  *
smg_comms_c_wrappers   19  * You should have received a copy of the GNU General Public License
smg_comms_c_wrappers   20  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
smg_comms_c_wrappers   21  */
smg_comms_c_wrappers   22 
smg_comms_c_wrappers   23 #include <stdio.h>
smg_comms_c_wrappers   24 #include <stdlib.h>
smg_comms_c_wrappers   25 
smg_comms_c_wrappers   26 #include "knobs.h"
smg_comms_c_wrappers   27 #include "mpi-internal.h"
smg_comms_c_wrappers   28 #include "longlong.h"
smg_comms_c_wrappers   29 
smg_comms_c_wrappers   30 mpi_limb_t
smg_comms_c_wrappers   31 mpihelp_sub_n( mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
smg_comms_c_wrappers   32 				  mpi_ptr_t s2_ptr, mpi_size_t size)
smg_comms_c_wrappers   33 {
smg_comms_c_wrappers   34     mpi_limb_t x, y, cy;
smg_comms_c_wrappers   35     mpi_size_t j;
smg_comms_c_wrappers   36 
smg_comms_c_wrappers   37     /* The loop counter and index J goes from -SIZE to -1.  This way
smg_comms_c_wrappers   38        the loop becomes faster.  */
smg_comms_c_wrappers   39     j = -size;
smg_comms_c_wrappers   40 
smg_comms_c_wrappers   41     /* Offset the base pointers to compensate for the negative indices.  */
smg_comms_c_wrappers   42     s1_ptr -= j;
smg_comms_c_wrappers   43     s2_ptr -= j;
smg_comms_c_wrappers   44     res_ptr -= j;
smg_comms_c_wrappers   45 
smg_comms_c_wrappers   46     cy = 0;
smg_comms_c_wrappers   47     do {
smg_comms_c_wrappers   48 	y = s2_ptr[j];
smg_comms_c_wrappers   49 	x = s1_ptr[j];
smg_comms_c_wrappers   50 	y += cy;		  /* add previous carry to subtrahend */
smg_comms_c_wrappers   51 	cy = y < cy;		  /* get out carry from that addition */
smg_comms_c_wrappers   52 	y = x - y;		  /* main subtract */
smg_comms_c_wrappers   53 	cy += y > x;		  /* get out carry from the subtract, combine */
smg_comms_c_wrappers   54 	res_ptr[j] = y;
smg_comms_c_wrappers   55     } while( ++j );
smg_comms_c_wrappers   56 
smg_comms_c_wrappers   57     return cy;
smg_comms_c_wrappers   58 }
smg_comms_c_wrappers   59 
smg_comms_c_wrappers   60