michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include <stdio.h>
michael@0: #include <stdlib.h>
michael@0: #include "mpi.h"
michael@0: #include "mpprime.h"
michael@0: #include <sys/types.h>
michael@0: #include <time.h>
michael@0: 
michael@0: #define MAX_PREC (4096 / MP_DIGIT_BIT)
michael@0: 
michael@0: mp_err identity_test(void)
michael@0: {
michael@0:   mp_size       preca, precb;
michael@0:   mp_err        res;
michael@0:   mp_int        a, b;
michael@0:   mp_int        t1, t2, t3, t4, t5;
michael@0: 
michael@0:   preca = (rand() % MAX_PREC) + 1;
michael@0:   precb = (rand() % MAX_PREC) + 1;
michael@0: 
michael@0:   MP_DIGITS(&a) = 0;
michael@0:   MP_DIGITS(&b) = 0;
michael@0:   MP_DIGITS(&t1) = 0;
michael@0:   MP_DIGITS(&t2) = 0;
michael@0:   MP_DIGITS(&t3) = 0;
michael@0:   MP_DIGITS(&t4) = 0;
michael@0:   MP_DIGITS(&t5) = 0;
michael@0: 
michael@0:   MP_CHECKOK( mp_init(&a)  );
michael@0:   MP_CHECKOK( mp_init(&b)  );
michael@0:   MP_CHECKOK( mp_init(&t1) );
michael@0:   MP_CHECKOK( mp_init(&t2) );
michael@0:   MP_CHECKOK( mp_init(&t3) );
michael@0:   MP_CHECKOK( mp_init(&t4) );
michael@0:   MP_CHECKOK( mp_init(&t5) );
michael@0: 
michael@0:   MP_CHECKOK( mpp_random_size(&a, preca) );
michael@0:   MP_CHECKOK( mpp_random_size(&b, precb) );
michael@0: 
michael@0:   if (mp_cmp(&a, &b) < 0)
michael@0:     mp_exch(&a, &b);
michael@0: 
michael@0:   MP_CHECKOK( mp_mod(&a, &b, &t1) );       /* t1 = a%b */
michael@0:   MP_CHECKOK( mp_div(&a, &b, &t2, NULL) ); /* t2 = a/b */
michael@0:   MP_CHECKOK( mp_mul(&b, &t2, &t3) );      /* t3 = (a/b)*b */
michael@0:   MP_CHECKOK( mp_add(&t1, &t3, &t4) );     /* t4 = a%b + (a/b)*b */
michael@0:   MP_CHECKOK( mp_sub(&t4, &a, &t5) );      /* t5 = a%b + (a/b)*b - a */
michael@0:   if (mp_cmp_z(&t5) != 0) {
michael@0:     res = MP_UNDEF;
michael@0:     goto CLEANUP;
michael@0:   }
michael@0: 
michael@0: CLEANUP:
michael@0:   mp_clear(&t5);
michael@0:   mp_clear(&t4);
michael@0:   mp_clear(&t3);
michael@0:   mp_clear(&t2);
michael@0:   mp_clear(&t1);
michael@0:   mp_clear(&b);
michael@0:   mp_clear(&a);
michael@0:   return res;
michael@0: }
michael@0: 
michael@0: int
michael@0: main(void)
michael@0: {
michael@0:   unsigned int  seed = (unsigned int)time(NULL);
michael@0:   unsigned long count = 0;
michael@0:   mp_err        res;
michael@0: 
michael@0:   srand(seed);
michael@0: 
michael@0:   while (MP_OKAY == (res = identity_test())) {
michael@0:      if ((++count % 100) == 0)
michael@0:        fputc('.', stderr);
michael@0:   }
michael@0: 
michael@0:   fprintf(stderr, "\ntest failed, err %d\n", res);
michael@0:   return res;
michael@0: }