/* oaddn.c: Addition modulo an integer N
Copyright 2003 Bjoern Butscher, Hendrik Weimer
This file is part of libquantum
libquantum 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 3 of the License,
or (at your option) any later version.
libquantum 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 libquantum; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
MA 02110-1301, USA
*/
#include
#include
#include
#include "matrix.h"
#include "measure.h"
#include "defs.h"
#include "gates.h"
#include "qureg.h"
#include "config.h"
/* if bit "compare" - the global enable bit - is set, test_sums
checks, if the sum of the c-number and the q-number in register
add_sum is greater than n and sets the next lower bit to "compare" */
void
test_sum(int compare, int width, quantum_reg *reg)
{
int i;
if (compare & ((MAX_UNSIGNED) 1 << (width - 1)))
{
quantum_cnot(2*width-1, width-1, reg);
quantum_sigma_x(2*width-1, reg);
quantum_cnot(2*width-1, 0, reg);
}
else
{
quantum_sigma_x(2*width-1, reg);
quantum_cnot(2*width-1,width-1, reg);
}
for (i = (width-2);i>0;i--)
{
if (compare & (1<*=0; i--){
if((1<*