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kc3-lang/libtommath/demo/demo.c

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  • Author : Francois Perrad
    Date : 2018-12-27 09:38:26
    Hash : ab074176
    Message : explicit condition

  • demo/demo.c
  • #include <string.h>
    #include <time.h>
    
    /*
     * Configuration
     */
    #ifndef LTM_DEMO_TEST_VS_MTEST
    #define LTM_DEMO_TEST_VS_MTEST 1
    #endif
    
    #ifndef LTM_DEMO_TEST_REDUCE_2K_L
    /* This test takes a moment so we disable it by default, but it can be:
     * 0 to disable testing
     * 1 to make the test with P = 2^1024 - 0x2A434 B9FDEC95 D8F9D550 FFFFFFFF FFFFFFFF
     * 2 to make the test with P = 2^2048 - 0x1 00000000 00000000 00000000 00000000 4945DDBF 8EA2A91D 5776399B B83E188F
     */
    #define LTM_DEMO_TEST_REDUCE_2K_L 0
    #endif
    
    #ifdef LTM_DEMO_REAL_RAND
    #define LTM_DEMO_RAND_SEED  time(NULL)
    #else
    #define LTM_DEMO_RAND_SEED  23
    #endif
    
    #include "tommath.h"
    
    static void ndraw(mp_int *a, const char *name)
    {
       char buf[16000];
    
       printf("%s: ", name);
       mp_toradix(a, buf, 10);
       printf("%s\n", buf);
       mp_toradix(a, buf, 16);
       printf("0x%s\n", buf);
    }
    
    #if LTM_DEMO_TEST_VS_MTEST != 0
    static void draw(mp_int *a)
    {
       ndraw(a, "");
    }
    #endif
    
    #if defined(LTM_DEMO_REAL_RAND) && !defined(_WIN32)
    static FILE *fd_urandom;
    #endif
    #if LTM_DEMO_TEST_VS_MTEST == 0
    static int myrng(unsigned char *dst, int len, void *dat)
    {
       int x;
       (void)dat;
    #if defined(LTM_DEMO_REAL_RAND)
       if (!fd_urandom) {
    #   if !defined(_WIN32)
          fprintf(stderr, "\nno /dev/urandom\n");
    #   endif
       } else {
          return fread(dst, 1uL, len, fd_urandom);
       }
    #endif
       for (x = 0; x < len;) {
          unsigned int r = (unsigned int)rand();
          do {
             dst[x++] = r & 0xFFu;
             r >>= 8;
          } while ((r != 0u) && (x < len));
       }
       return len;
    }
    #endif
    
    #if LTM_DEMO_TEST_VS_MTEST != 0
    static void _panic(int l)
    {
       fprintf(stderr, "\n%d: fgets failed\n", l);
       exit(EXIT_FAILURE);
    }
    
    #define FGETS(str, size, stream) \
       { \
          char *ret = fgets(str, size, stream); \
          if (!ret) { _panic(__LINE__); } \
       }
    #endif
    
    static mp_int a, b, c, d, e, f;
    
    static void _cleanup(void)
    {
       mp_clear_multi(&a, &b, &c, &d, &e, &f, NULL);
       printf("\n");
    
    #ifdef LTM_DEMO_REAL_RAND
       if (fd_urandom)
          fclose(fd_urandom);
    #endif
    }
    #if LTM_DEMO_TEST_VS_MTEST == 0
    struct mp_sqrtmod_prime_st {
       unsigned long p;
       unsigned long n;
       mp_digit r;
    };
    static struct mp_sqrtmod_prime_st sqrtmod_prime[] = {
       { 5, 14, 3 },
       { 7, 9, 4 },
       { 113, 2, 62 }
    };
    struct mp_jacobi_st {
       unsigned long n;
       int c[16];
    };
    static struct mp_jacobi_st jacobi[] = {
       { 3, {  1, -1,  0,  1, -1,  0,  1, -1,  0,  1, -1,  0,  1, -1,  0,  1 } },
       { 5, {  0,  1, -1, -1,  1,  0,  1, -1, -1,  1,  0,  1, -1, -1,  1,  0 } },
       { 7, {  1, -1,  1, -1, -1,  0,  1,  1, -1,  1, -1, -1,  0,  1,  1, -1 } },
       { 9, { -1,  1,  0,  1,  1,  0,  1,  1,  0,  1,  1,  0,  1,  1,  0,  1 } },
    };
    
    struct mp_kronecker_st {
       long n;
       int c[21];
    };
    static struct mp_kronecker_st kronecker[] = {
       /*-10, -9, -8, -7,-6, -5, -4, -3, -2, -1, 0, 1,  2,  3, 4,  5,  6,  7,  8, 9, 10*/
       { -10, {  0, -1,  0, -1, 0,  0,  0,  1,  0, -1, 0, 1,  0, -1, 0,  0,  0,  1,  0, 1,  0  } },
       {  -9, { -1,  0, -1,  1, 0, -1, -1,  0, -1, -1, 0, 1,  1,  0, 1,  1,  0, -1,  1, 0,  1  } },
       {  -8, {  0, -1,  0,  1, 0,  1,  0, -1,  0, -1, 0, 1,  0,  1, 0, -1,  0, -1,  0, 1,  0  } },
       {  -7, {  1, -1, -1,  0, 1,  1, -1,  1, -1, -1, 0, 1,  1, -1, 1, -1, -1,  0,  1, 1, -1  } },
       {  -6, {  0,  0,  0, -1, 0, -1,  0,  0,  0, -1, 0, 1,  0,  0, 0,  1,  0,  1,  0, 0,  0  } },
       {  -5, {  0, -1,  1, -1, 1,  0, -1, -1,  1, -1, 0, 1, -1,  1, 1,  0, -1,  1, -1, 1,  0  } },
       {  -4, {  0, -1,  0,  1, 0, -1,  0,  1,  0, -1, 0, 1,  0, -1, 0,  1,  0, -1,  0, 1,  0  } },
       {  -3, { -1,  0,  1, -1, 0,  1, -1,  0,  1, -1, 0, 1, -1,  0, 1, -1,  0,  1, -1, 0,  1  } },
       {  -2, {  0, -1,  0,  1, 0,  1,  0, -1,  0, -1, 0, 1,  0,  1, 0, -1,  0, -1,  0, 1,  0  } },
       {  -1, { -1, -1, -1,  1, 1, -1, -1,  1, -1, -1, 1, 1,  1, -1, 1,  1, -1, -1,  1, 1,  1  } },
       {   0, {  0,  0,  0,  0, 0,  0,  0,  0,  0,  1, 0, 1,  0,  0, 0,  0,  0,  0,  0, 0,  0  } },
       {   1, {  1,  1,  1,  1, 1,  1,  1,  1,  1,  1, 1, 1,  1,  1, 1,  1,  1,  1,  1, 1,  1  } },
       {   2, {  0,  1,  0,  1, 0, -1,  0, -1,  0,  1, 0, 1,  0, -1, 0, -1,  0,  1,  0, 1,  0  } },
       {   3, {  1,  0, -1, -1, 0, -1,  1,  0, -1,  1, 0, 1, -1,  0, 1, -1,  0, -1, -1, 0,  1  } },
       {   4, {  0,  1,  0,  1, 0,  1,  0,  1,  0,  1, 0, 1,  0,  1, 0,  1,  0,  1,  0, 1,  0  } },
       {   5, {  0,  1, -1, -1, 1,  0,  1, -1, -1,  1, 0, 1, -1, -1, 1,  0,  1, -1, -1, 1,  0  } },
       {   6, {  0,  0,  0, -1, 0,  1,  0,  0,  0,  1, 0, 1,  0,  0, 0,  1,  0, -1,  0, 0,  0  } },
       {   7, { -1,  1,  1,  0, 1, -1,  1,  1,  1,  1, 0, 1,  1,  1, 1, -1,  1,  0,  1, 1, -1  } },
       {   8, {  0,  1,  0,  1, 0, -1,  0, -1,  0,  1, 0, 1,  0, -1, 0, -1,  0,  1,  0, 1,  0  } },
       {   9, {  1,  0,  1,  1, 0,  1,  1,  0,  1,  1, 0, 1,  1,  0, 1,  1,  0,  1,  1, 0,  1  } },
       {  10, {  0,  1,  0, -1, 0,  0,  0,  1,  0,  1, 0, 1,  0,  1, 0,  0,  0, -1,  0, 1,  0  } }
    };
    #endif
    
    #if LTM_DEMO_TEST_VS_MTEST != 0
    static char cmd[4096];
    #endif
    static char buf[4096];
    int main(void)
    {
       unsigned rr;
       int ix;
    #if LTM_DEMO_TEST_VS_MTEST != 0
       unsigned long expt_n, add_n, sub_n, mul_n, div_n, sqr_n, mul2d_n, div2d_n,
                gcd_n, lcm_n, inv_n, div2_n, mul2_n, add_d_n, sub_d_n;
    #else
       unsigned long s, t;
       long k, m;
       unsigned long long q, r;
       mp_digit mp;
       int i, n, err, should, cnt;
    #endif
    
       if (mp_init_multi(&a, &b, &c, &d, &e, &f, NULL)!= MP_OKAY)
          return EXIT_FAILURE;
    
       atexit(_cleanup);
    
    #if defined(LTM_DEMO_REAL_RAND)
       if (!fd_urandom) {
          fd_urandom = fopen("/dev/urandom", "r");
          if (!fd_urandom) {
    #   if !defined(_WIN32)
             fprintf(stderr, "\ncould not open /dev/urandom\n");
    #   endif
          }
       }
    #endif
       srand(LTM_DEMO_RAND_SEED);
    
    #ifdef MP_8BIT
       printf("Digit size 8 Bit \n");
    #endif
    #ifdef MP_16BIT
       printf("Digit size 16 Bit \n");
    #endif
    #ifdef MP_32BIT
       printf("Digit size 32 Bit \n");
    #endif
    #ifdef MP_64BIT
       printf("Digit size 64 Bit \n");
    #endif
       printf("Size of mp_digit: %u\n", (unsigned int)sizeof(mp_digit));
       printf("Size of mp_word: %u\n", (unsigned int)sizeof(mp_word));
       printf("DIGIT_BIT: %d\n", DIGIT_BIT);
       printf("MP_PREC: %d\n", MP_PREC);
    
    #if LTM_DEMO_TEST_VS_MTEST == 0
       /* trivial stuff */
       /* a: 0->5 */
       mp_set_int(&a, 5);
       /* a: 5-> b: -5 */
       mp_neg(&a, &b);
       if (mp_cmp(&a, &b) != MP_GT) {
          return EXIT_FAILURE;
       }
       if (mp_cmp(&b, &a) != MP_LT) {
          return EXIT_FAILURE;
       }
       /* a: 5-> a: -5 */
       mp_neg(&a, &a);
       if (mp_cmp(&b, &a) != MP_EQ) {
          return EXIT_FAILURE;
       }
       /* a: -5-> b: 5 */
       mp_abs(&a, &b);
       if (mp_isneg(&b) != MP_NO) {
          return EXIT_FAILURE;
       }
       /* a: -5-> b: -4 */
       mp_add_d(&a, 1uL, &b);
       if (mp_isneg(&b) != MP_YES) {
          return EXIT_FAILURE;
       }
       if (mp_get_int(&b) != 4) {
          return EXIT_FAILURE;
       }
       /* a: -5-> b: 1 */
       mp_add_d(&a, 6uL, &b);
       if (mp_get_int(&b) != 1) {
          return EXIT_FAILURE;
       }
       /* a: -5-> a: 1 */
       mp_add_d(&a, 6uL, &a);
       if (mp_get_int(&a) != 1) {
          return EXIT_FAILURE;
       }
       mp_zero(&a);
       /* a: 0-> a: 6 */
       mp_add_d(&a, 6uL, &a);
       if (mp_get_int(&a) != 6) {
          return EXIT_FAILURE;
       }
    
       mp_set_int(&a, 42);
       mp_set_int(&b, 1);
       mp_neg(&b, &b);
       mp_set_int(&c, 1);
       mp_exptmod(&a, &b, &c, &d);
    
       mp_set_int(&c, 7);
       mp_exptmod(&a, &b, &c, &d);
    
    
       mp_set_int(&a, 0);
       mp_set_int(&b, 1);
       if ((err = mp_jacobi(&a, &b, &i)) != MP_OKAY) {
          printf("Failed executing mp_jacobi(0 | 1) %s.\n", mp_error_to_string(err));
          return EXIT_FAILURE;
       }
       if (i != 1) {
          printf("Failed trivial mp_jacobi(0 | 1) %d != 1\n", i);
          return EXIT_FAILURE;
       }
       for (cnt = 0; cnt < (int)(sizeof(jacobi)/sizeof(jacobi[0])); ++cnt) {
          mp_set_int(&b, jacobi[cnt].n);
          /* only test positive values of a */
          for (n = -5; n <= 10; ++n) {
             mp_set_int(&a, abs(n));
             should = MP_OKAY;
             if (n < 0) {
                mp_neg(&a, &a);
                /* Until #44 is fixed the negative a's must fail */
                should = MP_VAL;
             }
             if ((err = mp_jacobi(&a, &b, &i)) != should) {
                printf("Failed executing mp_jacobi(%d | %lu) %s.\n", n, jacobi[cnt].n, mp_error_to_string(err));
                return EXIT_FAILURE;
             }
             if ((err == MP_OKAY) && (i != jacobi[cnt].c[n + 5])) {
                printf("Failed trivial mp_jacobi(%d | %lu) %d != %d\n", n, jacobi[cnt].n, i, jacobi[cnt].c[n + 5]);
                return EXIT_FAILURE;
             }
          }
       }
    
    
       mp_set_int(&a, 0);
       mp_set_int(&b, 1u);
       if ((err = mp_kronecker(&a, &b, &i)) != MP_OKAY) {
          printf("Failed executing mp_kronecker(0 | 1) %s.\n", mp_error_to_string(err));
          return EXIT_FAILURE;
       }
       if (i != 1) {
          printf("Failed trivial mp_kronecker(0 | 1) %d != 1\n", i);
          return EXIT_FAILURE;
       }
       for (cnt = 0; cnt < (int)(sizeof(kronecker)/sizeof(kronecker[0])); ++cnt) {
          k = kronecker[cnt].n;
          if (k < 0) {
             mp_set_int(&a, (unsigned long)(-k));
             mp_neg(&a, &a);
          } else {
             mp_set_int(&a, (unsigned long) k);
          }
          /* only test positive values of a */
          for (m = -10; m <= 10; m++) {
             if (m < 0) {
                mp_set_int(&b,(unsigned long)(-m));
                mp_neg(&b, &b);
             } else {
                mp_set_int(&b, (unsigned long) m);
             }
             if ((err = mp_kronecker(&a, &b, &i)) != MP_OKAY) {
                printf("Failed executing mp_kronecker(%ld | %ld) %s.\n", kronecker[cnt].n, m, mp_error_to_string(err));
                return EXIT_FAILURE;
             }
             if ((err == MP_OKAY) && (i != kronecker[cnt].c[m + 10])) {
                printf("Failed trivial mp_kronecker(%ld | %ld) %d != %d\n", kronecker[cnt].n, m, i, kronecker[cnt].c[m + 10]);
                return EXIT_FAILURE;
             }
          }
       }
       /* test mp_complement */
       printf("\n\nTesting: mp_complement");
       for (i = 0; i < 1000; ++i) {
          int l = (rand() * rand() + 1) * (rand() % 1 ? -1 : 1);
          mp_set_int(&a, labs(l));
          if (l < 0)
             mp_neg(&a, &a);
          mp_complement(&a, &b);
    
          l = ~l;
          mp_set_int(&c, labs(l));
          if (l < 0)
             mp_neg(&c, &c);
    
          if (mp_cmp(&b, &c) != MP_EQ) {
             printf("\nmp_complement() bad result!");
             return EXIT_FAILURE;
          }
       }
    
       /* test mp_tc_div_2d */
       printf("\n\nTesting: mp_tc_div_2d");
       for (i = 0; i < 1000; ++i) {
          int l, em;
    
          l = (rand() * rand() + 1) * (rand() % 1 ? -1 : 1);
          mp_set_int(&a, labs(l));
          if (l < 0)
             mp_neg(&a, &a);
    
          em = rand() % 32;
    
          mp_set_int(&d, labs(l >> em));
          if ((l >> em) < 0)
             mp_neg(&d, &d);
    
          mp_tc_div_2d(&a, em, &b);
          if (mp_cmp(&b, &d) != MP_EQ) {
             printf("\nmp_tc_div_2d() bad result!");
             return EXIT_FAILURE;
          }
       }
    
       /* test mp_tc_xor */
       printf("\n\nTesting: mp_tc_xor");
       for (i = 0; i < 1000; ++i) {
          int l, em;
    
          l = (rand() * rand() + 1) * (rand() % 1 ? -1 : 1);
          mp_set_int(&a, labs(l));
          if (l < 0)
             mp_neg(&a, &a);
    
          em = (rand() * rand() + 1) * (rand() % 1 ? -1 : 1);
          mp_set_int(&b, labs(em));
          if (em < 0)
             mp_neg(&b, &b);
    
          mp_set_int(&d, labs(l ^ em));
          if ((l ^ em) < 0)
             mp_neg(&d, &d);
    
          mp_tc_xor(&a, &b, &c);
          if (mp_cmp(&c, &d) != MP_EQ) {
             printf("\nmp_tc_xor() bad result!");
             return EXIT_FAILURE;
          }
       }
    
       /* test mp_tc_or */
       printf("\n\nTesting: mp_tc_or");
       for (i = 0; i < 1000; ++i) {
          int l, em;
    
          l = (rand() * rand() + 1) * (rand() % 1 ? -1 : 1);
          mp_set_int(&a, labs(l));
          if (l < 0)
             mp_neg(&a, &a);
    
          em = (rand() * rand() + 1) * (rand() % 1 ? -1 : 1);
          mp_set_int(&b, labs(em));
          if (em < 0)
             mp_neg(&b, &b);
    
          mp_set_int(&d, labs(l | em));
          if ((l | em) < 0)
             mp_neg(&d, &d);
    
          mp_tc_or(&a, &b, &c);
          if (mp_cmp(&c, &d) != MP_EQ) {
             printf("\nmp_tc_or() bad result!");
             return EXIT_FAILURE;
          }
       }
    
       /* test mp_tc_and */
       printf("\n\nTesting: mp_tc_and");
       for (i = 0; i < 1000; ++i) {
          int l, em;
    
          l = (rand() * rand() + 1) * (rand() % 1 ? -1 : 1);
          mp_set_int(&a, labs(l));
          if (l < 0)
             mp_neg(&a, &a);
    
          em = (rand() * rand() + 1) * (rand() % 1 ? -1 : 1);
          mp_set_int(&b, labs(em));
          if (em < 0)
             mp_neg(&b, &b);
    
          mp_set_int(&d, labs(l & em));
          if ((l & em) < 0)
             mp_neg(&d, &d);
    
          mp_tc_and(&a, &b, &c);
          if (mp_cmp(&c, &d) != MP_EQ) {
             printf("\nmp_tc_and() bad result!");
             return EXIT_FAILURE;
          }
       }
    
       /* mp_invmod corner-case of https://github.com/libtom/libtommath/issues/118 */
       printf("\n\nTesting: mp_invmod");
       {
          const char *a_ = "47182BB8DF0FFE9F61B1F269BACC066B48BA145D35137D426328DC3F88A5EA44";
          const char *b_ = "FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF00000000FFFFFFFFFFFFFFFF";
          const char *should_ = "0521A82E10376F8E4FDEF9A32A427AC2A0FFF686E00290D39E3E4B5522409596";
    
          if (mp_read_radix(&a, a_, 16) != MP_OKAY) {
             printf("\nmp_read_radix(a) failed!");
             return EXIT_FAILURE;
          }
          if (mp_read_radix(&b, b_, 16) != MP_OKAY) {
             printf("\nmp_read_radix(b) failed!");
             return EXIT_FAILURE;
          }
          if (mp_read_radix(&c, should_, 16) != MP_OKAY) {
             printf("\nmp_read_radix(should) failed!");
             return EXIT_FAILURE;
          }
    
          if (mp_invmod(&a, &b, &d) != MP_OKAY) {
             printf("\nmp_invmod() failed!");
             return EXIT_FAILURE;
          }
    
          if (mp_cmp(&c, &d) != MP_EQ) {
             printf("\nmp_invmod() bad result!");
             return EXIT_FAILURE;
          }
       }
    
       /* test mp_get_double/mp_set_double */
    #if defined(__STDC_IEC_559__) || defined(__GCC_IEC_559)
       printf("\n\nTesting: mp_get_double");
       if (mp_set_double(&a, +1.0/0.0) != MP_VAL) {
          printf("\nmp_set_double should return MP_VAL for +inf");
          return EXIT_FAILURE;
       }
       if (mp_set_double(&a, -1.0/0.0) != MP_VAL) {
          printf("\nmp_set_double should return MP_VAL for -inf");
          return EXIT_FAILURE;
       }
       if (mp_set_double(&a, +0.0/0.0) != MP_VAL) {
          printf("\nmp_set_double should return MP_VAL for NaN");
          return EXIT_FAILURE;
       }
       if (mp_set_double(&a, -0.0/0.0) != MP_VAL) {
          printf("\nmp_set_double should return MP_VAL for NaN");
          return EXIT_FAILURE;
       }
    
       for (i = 0; i < 1000; ++i) {
          int tmp = rand();
          double dbl = (double)tmp * rand() + 1;
          if (mp_set_double(&a, dbl) != MP_OKAY) {
             printf("\nmp_set_double() failed");
             return EXIT_FAILURE;
          }
          if (dbl != mp_get_double(&a)) {
             printf("\nmp_get_double() bad result!");
             return EXIT_FAILURE;
          }
          if (mp_set_double(&a, -dbl) != MP_OKAY) {
             printf("\nmp_set_double() failed");
             return EXIT_FAILURE;
          }
          if (-dbl != mp_get_double(&a)) {
             printf("\nmp_get_double() bad result!");
             return EXIT_FAILURE;
          }
       }
    #endif
    
       /* test mp_get_int */
       printf("\n\nTesting: mp_get_int");
       for (i = 0; i < 1000; ++i) {
          t = (unsigned long)(rand() * rand() + 1) & 0xFFFFFFFFuL;
          mp_set_int(&a, t);
          if (t != mp_get_int(&a)) {
             printf("\nmp_get_int() bad result!");
             return EXIT_FAILURE;
          }
       }
       mp_set_int(&a, 0);
       if (mp_get_int(&a) != 0) {
          printf("\nmp_get_int() bad result!");
          return EXIT_FAILURE;
       }
       mp_set_int(&a, 0xFFFFFFFFuL);
       if (mp_get_int(&a) != 0xFFFFFFFFuL) {
          printf("\nmp_get_int() bad result!");
          return EXIT_FAILURE;
       }
    
       printf("\n\nTesting: mp_get_long\n");
       for (i = 0; i < ((int)(sizeof(unsigned long)*CHAR_BIT) - 1); ++i) {
          t = (1ULL << (i+1)) - 1;
          if (!t)
             t = -1;
          printf(" t = 0x%lx i = %d\r", t, i);
          do {
             if (mp_set_long(&a, t) != MP_OKAY) {
                printf("\nmp_set_long() error!");
                return EXIT_FAILURE;
             }
             s = mp_get_long(&a);
             if (s != t) {
                printf("\nmp_get_long() bad result! 0x%lx != 0x%lx", s, t);
                return EXIT_FAILURE;
             }
             t <<= 1;
          } while (t != 0uL);
       }
    
       printf("\n\nTesting: mp_get_long_long\n");
       for (i = 0; i < ((int)(sizeof(unsigned long long)*CHAR_BIT) - 1); ++i) {
          r = (1ULL << (i+1)) - 1;
          if (!r)
             r = -1;
          printf(" r = 0x%llx i = %d\r", r, i);
          do {
             if (mp_set_long_long(&a, r) != MP_OKAY) {
                printf("\nmp_set_long_long() error!");
                return EXIT_FAILURE;
             }
             q = mp_get_long_long(&a);
             if (q != r) {
                printf("\nmp_get_long_long() bad result! 0x%llx != 0x%llx", q, r);
                return EXIT_FAILURE;
             }
             r <<= 1;
          } while (r != 0uLL);
       }
    
       /* test mp_sqrt */
       printf("\n\nTesting: mp_sqrt\n");
       for (i = 0; i < 1000; ++i) {
          printf("%6d\r", i);
          fflush(stdout);
          n = (rand() & 15) + 1;
          mp_rand(&a, n);
          if (mp_sqrt(&a, &b) != MP_OKAY) {
             printf("\nmp_sqrt() error!");
             return EXIT_FAILURE;
          }
          mp_n_root_ex(&a, 2, &c, 0);
          mp_n_root_ex(&a, 2, &d, 1);
          if (mp_cmp_mag(&c, &d) != MP_EQ) {
             printf("\nmp_n_root_ex() bad result!");
             return EXIT_FAILURE;
          }
          if (mp_cmp_mag(&b, &c) != MP_EQ) {
             printf("mp_sqrt() bad result!\n");
             return EXIT_FAILURE;
          }
       }
    
       printf("\n\nTesting: mp_is_square\n");
       for (i = 0; i < 1000; ++i) {
          printf("%6d\r", i);
          fflush(stdout);
    
          /* test mp_is_square false negatives */
          n = (rand() & 7) + 1;
          mp_rand(&a, n);
          mp_sqr(&a, &a);
          if (mp_is_square(&a, &n) != MP_OKAY) {
             printf("\nfn:mp_is_square() error!");
             return EXIT_FAILURE;
          }
          if (n == 0) {
             printf("\nfn:mp_is_square() bad result!");
             return EXIT_FAILURE;
          }
    
          /* test for false positives */
          mp_add_d(&a, 1uL, &a);
          if (mp_is_square(&a, &n) != MP_OKAY) {
             printf("\nfp:mp_is_square() error!");
             return EXIT_FAILURE;
          }
          if (n == 1) {
             printf("\nfp:mp_is_square() bad result!");
             return EXIT_FAILURE;
          }
    
       }
       printf("\n\n");
    
       /* r^2 = n (mod p) */
       for (i = 0; i < (int)(sizeof(sqrtmod_prime)/sizeof(sqrtmod_prime[0])); ++i) {
          mp_set_int(&a, sqrtmod_prime[i].p);
          mp_set_int(&b, sqrtmod_prime[i].n);
          if (mp_sqrtmod_prime(&b, &a, &c) != MP_OKAY) {
             printf("Failed executing %d. mp_sqrtmod_prime\n", (i+1));
             return EXIT_FAILURE;
          }
          if (mp_cmp_d(&c, sqrtmod_prime[i].r) != MP_EQ) {
             printf("Failed %d. trivial mp_sqrtmod_prime\n", (i+1));
             ndraw(&c, "r");
             return EXIT_FAILURE;
          }
       }
    
       /* test for size */
       for (ix = 10; ix < 128; ix++) {
          printf("Testing (not safe-prime): %9d bits    \r", ix);
          fflush(stdout);
          err = mp_prime_random_ex(&a, 8, ix,
                                   (rand() & 1) ? 0 : LTM_PRIME_2MSB_ON, myrng,
                                   NULL);
          if (err != MP_OKAY) {
             printf("failed with err code %d\n", err);
             return EXIT_FAILURE;
          }
          if (mp_count_bits(&a) != ix) {
             printf("Prime is %d not %d bits!!!\n", mp_count_bits(&a), ix);
             return EXIT_FAILURE;
          }
       }
       printf("\n");
    
    
       /* strong Miller-Rabin pseudoprime to the first 200 primes (F. Arnault) */
       puts("Testing mp_prime_is_prime() with Arnault's pseudoprime  803...901 \n");
       mp_read_radix(&a,
                     "91xLNF3roobhzgTzoFIG6P13ZqhOVYSN60Fa7Cj2jVR1g0k89zdahO9/kAiRprpfO1VAp1aBHucLFV/qLKLFb+zonV7R2Vxp1K13ClwUXStpV0oxTNQVjwybmFb5NBEHImZ6V7P6+udRJuH8VbMEnS0H8/pSqQrg82OoQQ2fPpAk6G1hkjqoCv5s/Yr",
                     64);
       mp_prime_is_prime(&a, 8, &cnt);
       if (cnt == MP_YES) {
          printf("Arnault's pseudoprime is not prime but mp_prime_is_prime says it is.\n");
          return EXIT_FAILURE;
       }
       /* About the same size as Arnault's pseudoprime */
       puts("Testing mp_prime_is_prime() with certified prime 2^1119 + 53\n");
       mp_set(&a,1u);
       mp_mul_2d(&a,1119,&a);
       mp_add_d(&a,53,&a);
       mp_prime_is_prime(&a, 8, &cnt);
       if (cnt == MP_NO) {
          printf("A certified prime is a prime but mp_prime_is_prime says it not.\n");
          return EXIT_FAILURE;
       }
       for (ix = 16; ix < 128; ix++) {
          printf("Testing (    safe-prime): %9d bits    \r", ix);
          fflush(stdout);
          err = mp_prime_random_ex(
                   &a, 8, ix, ((rand() & 1) ? 0 : LTM_PRIME_2MSB_ON) | LTM_PRIME_SAFE,
                   myrng, NULL);
          if (err != MP_OKAY) {
             printf("failed with err code %d\n", err);
             return EXIT_FAILURE;
          }
          if (mp_count_bits(&a) != ix) {
             printf("Prime is %d not %d bits!!!\n", mp_count_bits(&a), ix);
             return EXIT_FAILURE;
          }
          /* let's see if it's really a safe prime */
          mp_sub_d(&a, 1uL, &a);
          mp_div_2(&a, &a);
          mp_prime_is_prime(&a, 8, &cnt);
          if (cnt != MP_YES) {
             printf("sub is not prime!\n");
             return EXIT_FAILURE;
          }
       }
    
       printf("\n\n");
    
       /* test montgomery */
       printf("Testing: montgomery...\n");
       for (i = 1; i <= 10; i++) {
          if (i == 10)
             i = 1000;
          printf(" digit size: %2d\r", i);
          fflush(stdout);
          for (n = 0; n < 1000; n++) {
             mp_rand(&a, i);
             a.dp[0] |= 1;
    
             /* let's see if R is right */
             mp_montgomery_calc_normalization(&b, &a);
             mp_montgomery_setup(&a, &mp);
    
             /* now test a random reduction */
             for (ix = 0; ix < 100; ix++) {
                mp_rand(&c, 1 + abs(rand()) % (2*i));
                mp_copy(&c, &d);
                mp_copy(&c, &e);
    
                mp_mod(&d, &a, &d);
                mp_montgomery_reduce(&c, &a, mp);
                mp_mulmod(&c, &b, &a, &c);
    
                if (mp_cmp(&c, &d) != MP_EQ) {
    /* *INDENT-OFF* */
                   printf("d = e mod a, c = e MOD a\n");
                   mp_todecimal(&a, buf); printf("a = %s\n", buf);
                   mp_todecimal(&e, buf); printf("e = %s\n", buf);
                   mp_todecimal(&d, buf); printf("d = %s\n", buf);
                   mp_todecimal(&c, buf); printf("c = %s\n", buf);
                   printf("compare no compare!\n"); return EXIT_FAILURE;
    /* *INDENT-ON* */
                }
                /* only one big montgomery reduction */
                if (i > 10) {
                   n = 1000;
                   ix = 100;
                }
             }
          }
       }
    
       printf("\n\n");
    
       mp_read_radix(&a, "123456", 10);
       mp_toradix_n(&a, buf, 10, 3);
       printf("a == %s\n", buf);
       mp_toradix_n(&a, buf, 10, 4);
       printf("a == %s\n", buf);
       mp_toradix_n(&a, buf, 10, 30);
       printf("a == %s\n", buf);
    
    
    #if 0
       for (;;) {
          fgets(buf, sizeof(buf), stdin);
          mp_read_radix(&a, buf, 10);
          mp_prime_next_prime(&a, 5, 1);
          mp_toradix(&a, buf, 10);
          printf("%s, %lu\n", buf, a.dp[0] & 3);
       }
    #endif
    
       /* test mp_cnt_lsb */
       printf("\n\nTesting: mp_cnt_lsb");
       mp_set(&a, 1uL);
       for (ix = 0; ix < 1024; ix++) {
          if (mp_cnt_lsb(&a) != ix) {
             printf("Failed at %d, %d\n", ix, mp_cnt_lsb(&a));
             return EXIT_FAILURE;
          }
          mp_mul_2(&a, &a);
       }
    
       /* test mp_reduce_2k */
       printf("\n\nTesting: mp_reduce_2k\n");
       for (cnt = 3; cnt <= 128; ++cnt) {
          mp_digit tmp;
    
          mp_2expt(&a, cnt);
          mp_sub_d(&a, 2uL, &a);  /* a = 2**cnt - 2 */
    
          printf("\r %4d bits", cnt);
          printf("(%d)", mp_reduce_is_2k(&a));
          mp_reduce_2k_setup(&a, &tmp);
          printf("(%lu)", (unsigned long) tmp);
          for (ix = 0; ix < 1000; ix++) {
             if (!(ix & 127)) {
                printf(".");
                fflush(stdout);
             }
             mp_rand(&b, (cnt / DIGIT_BIT + 1) * 2);
             mp_copy(&c, &b);
             mp_mod(&c, &a, &c);
             mp_reduce_2k(&b, &a, 2uL);
             if (mp_cmp(&c, &b) != MP_EQ) {
                printf("FAILED\n");
                return EXIT_FAILURE;
             }
          }
       }
    
       /* test mp_div_3  */
       printf("\n\nTesting: mp_div_3...\n");
       mp_set(&d, 3uL);
       for (cnt = 0; cnt < 10000;) {
          mp_digit r2;
    
          if (!(++cnt & 127)) {
             printf("%9d\r", cnt);
             fflush(stdout);
          }
          mp_rand(&a, abs(rand()) % 128 + 1);
          mp_div(&a, &d, &b, &e);
          mp_div_3(&a, &c, &r2);
    
          if (mp_cmp(&b, &c) || mp_cmp_d(&e, r2)) {
             printf("\nmp_div_3 => Failure\n");
          }
       }
       printf("\nPassed div_3 testing");
    
       /* test the DR reduction */
       printf("\n\nTesting: mp_dr_reduce...\n");
       for (cnt = 2; cnt < 32; cnt++) {
          printf("\r%d digit modulus", cnt);
          mp_grow(&a, cnt);
          mp_zero(&a);
          for (ix = 1; ix < cnt; ix++) {
             a.dp[ix] = MP_MASK;
          }
          a.used = cnt;
          a.dp[0] = 3;
    
          mp_rand(&b, cnt - 1);
          mp_copy(&b, &c);
    
          rr = 0;
          do {
             if (!(rr & 127)) {
                printf(".");
                fflush(stdout);
             }
             mp_sqr(&b, &b);
             mp_add_d(&b, 1uL, &b);
             mp_copy(&b, &c);
    
             mp_mod(&b, &a, &b);
             mp_dr_setup(&a, &mp);
             mp_dr_reduce(&c, &a, mp);
    
             if (mp_cmp(&b, &c) != MP_EQ) {
                printf("Failed on trial %u\n", rr);
                return EXIT_FAILURE;
             }
          } while (++rr < 500);
          printf(" passed");
          fflush(stdout);
       }
    
    #   if LTM_DEMO_TEST_REDUCE_2K_L
       /* test the mp_reduce_2k_l code */
    #      if LTM_DEMO_TEST_REDUCE_2K_L == 1
       /* first load P with 2^1024 - 0x2A434 B9FDEC95 D8F9D550 FFFFFFFF FFFFFFFF */
       mp_2expt(&a, 1024);
       mp_read_radix(&b, "2A434B9FDEC95D8F9D550FFFFFFFFFFFFFFFF", 16);
       mp_sub(&a, &b, &a);
    #      elif LTM_DEMO_TEST_REDUCE_2K_L == 2
       /*  p = 2^2048 - 0x1 00000000 00000000 00000000 00000000 4945DDBF 8EA2A91D 5776399B B83E188F  */
       mp_2expt(&a, 2048);
       mp_read_radix(&b,
                     "1000000000000000000000000000000004945DDBF8EA2A91D5776399BB83E188F",
                     16);
       mp_sub(&a, &b, &a);
    #      else
    #         error oops
    #      endif
    
       mp_todecimal(&a, buf);
       printf("\n\np==%s\n", buf);
       /* now mp_reduce_is_2k_l() should return */
       if (mp_reduce_is_2k_l(&a) != 1) {
          printf("mp_reduce_is_2k_l() return 0, should be 1\n");
          return EXIT_FAILURE;
       }
       mp_reduce_2k_setup_l(&a, &d);
       /* now do a million square+1 to see if it varies */
       mp_rand(&b, 64);
       mp_mod(&b, &a, &b);
       mp_copy(&b, &c);
       printf("Testing: mp_reduce_2k_l...");
       fflush(stdout);
       for (cnt = 0; cnt < (int)(1UL << 20); cnt++) {
          mp_sqr(&b, &b);
          mp_add_d(&b, 1uL, &b);
          mp_reduce_2k_l(&b, &a, &d);
          mp_sqr(&c, &c);
          mp_add_d(&c, 1uL, &c);
          mp_mod(&c, &a, &c);
          if (mp_cmp(&b, &c) != MP_EQ) {
             printf("mp_reduce_2k_l() failed at step %d\n", cnt);
             mp_tohex(&b, buf);
             printf("b == %s\n", buf);
             mp_tohex(&c, buf);
             printf("c == %s\n", buf);
             return EXIT_FAILURE;
          }
       }
       printf("...Passed\n");
    #   endif /* LTM_DEMO_TEST_REDUCE_2K_L */
    
    #else
       div2_n = mul2_n = inv_n = expt_n = lcm_n = gcd_n = add_n =
                                             sub_n = mul_n = div_n = sqr_n = mul2d_n = div2d_n = add_d_n = sub_d_n = 0;
    
       /* force KARA and TOOM to enable despite cutoffs */
       KARATSUBA_SQR_CUTOFF = KARATSUBA_MUL_CUTOFF = 8;
       TOOM_SQR_CUTOFF = TOOM_MUL_CUTOFF = 16;
    
       for (;;) {
          /* randomly clear and re-init one variable, this has the affect of triming the alloc space */
          switch (abs(rand()) % 7) {
          case 0:
             mp_clear(&a);
             mp_init(&a);
             break;
          case 1:
             mp_clear(&b);
             mp_init(&b);
             break;
          case 2:
             mp_clear(&c);
             mp_init(&c);
             break;
          case 3:
             mp_clear(&d);
             mp_init(&d);
             break;
          case 4:
             mp_clear(&e);
             mp_init(&e);
             break;
          case 5:
             mp_clear(&f);
             mp_init(&f);
             break;
          case 6:
             break;        /* don't clear any */
          }
    
    
          printf("%4lu/%4lu/%4lu/%4lu/%4lu/%4lu/%4lu/%4lu/%4lu/%4lu/%4lu/%4lu/%4lu/%4lu/%4lu ",
                 add_n, sub_n, mul_n, div_n, sqr_n, mul2d_n, div2d_n, gcd_n, lcm_n,
                 expt_n, inv_n, div2_n, mul2_n, add_d_n, sub_d_n);
          FGETS(cmd, 4095, stdin);
          cmd[strlen(cmd) - 1u] = '\0';
          printf("%-6s ]\r", cmd);
          fflush(stdout);
          if (strcmp(cmd, "mul2d") == 0) {
             ++mul2d_n;
             FGETS(buf, 4095, stdin);
             mp_read_radix(&a, buf, 64);
             FGETS(buf, 4095, stdin);
             sscanf(buf, "%u", &rr);
             FGETS(buf, 4095, stdin);
             mp_read_radix(&b, buf, 64);
    
             mp_mul_2d(&a, rr, &a);
             a.sign = b.sign;
             if (mp_cmp(&a, &b) != MP_EQ) {
                printf("mul2d failed, rr == %u\n", rr);
                draw(&a);
                draw(&b);
                return EXIT_FAILURE;
             }
          } else if (strcmp(cmd, "div2d") == 0) {
             ++div2d_n;
             FGETS(buf, 4095, stdin);
             mp_read_radix(&a, buf, 64);
             FGETS(buf, 4095, stdin);
             sscanf(buf, "%u", &rr);
             FGETS(buf, 4095, stdin);
             mp_read_radix(&b, buf, 64);
    
             mp_div_2d(&a, rr, &a, &e);
             a.sign = b.sign;
             if ((a.used == b.used) && (a.used == 0)) {
                a.sign = b.sign = MP_ZPOS;
             }
             if (mp_cmp(&a, &b) != MP_EQ) {
                printf("div2d failed, rr == %u\n", rr);
                draw(&a);
                draw(&b);
                return EXIT_FAILURE;
             }
          } else if (strcmp(cmd, "add") == 0) {
             ++add_n;
             FGETS(buf, 4095, stdin);
             mp_read_radix(&a, buf, 64);
             FGETS(buf, 4095, stdin);
             mp_read_radix(&b, buf, 64);
             FGETS(buf, 4095, stdin);
             mp_read_radix(&c, buf, 64);
             mp_copy(&a, &d);
             mp_add(&d, &b, &d);
             if (mp_cmp(&c, &d) != MP_EQ) {
                printf("add %lu failure!\n", add_n);
                draw(&a);
                draw(&b);
                draw(&c);
                draw(&d);
                return EXIT_FAILURE;
             }
    
             /* test the sign/unsigned storage functions */
    
             rr = mp_signed_bin_size(&c);
             mp_to_signed_bin(&c, (unsigned char *) cmd);
             memset(cmd + rr, rand() & 0xFFu, sizeof(cmd) - rr);
             mp_read_signed_bin(&d, (unsigned char *) cmd, rr);
             if (mp_cmp(&c, &d) != MP_EQ) {
                printf("mp_signed_bin failure!\n");
                draw(&c);
                draw(&d);
                return EXIT_FAILURE;
             }
    
    
             rr = mp_unsigned_bin_size(&c);
             mp_to_unsigned_bin(&c, (unsigned char *) cmd);
             memset(cmd + rr, rand() & 0xFFu, sizeof(cmd) - rr);
             mp_read_unsigned_bin(&d, (unsigned char *) cmd, rr);
             if (mp_cmp_mag(&c, &d) != MP_EQ) {
                printf("mp_unsigned_bin failure!\n");
                draw(&c);
                draw(&d);
                return EXIT_FAILURE;
             }
    
          } else if (strcmp(cmd, "sub") == 0) {
             ++sub_n;
             FGETS(buf, 4095, stdin);
             mp_read_radix(&a, buf, 64);
             FGETS(buf, 4095, stdin);
             mp_read_radix(&b, buf, 64);
             FGETS(buf, 4095, stdin);
             mp_read_radix(&c, buf, 64);
             mp_copy(&a, &d);
             mp_sub(&d, &b, &d);
             if (mp_cmp(&c, &d) != MP_EQ) {
                printf("sub %lu failure!\n", sub_n);
                draw(&a);
                draw(&b);
                draw(&c);
                draw(&d);
                return EXIT_FAILURE;
             }
          } else if (strcmp(cmd, "mul") == 0) {
             ++mul_n;
             FGETS(buf, 4095, stdin);
             mp_read_radix(&a, buf, 64);
             FGETS(buf, 4095, stdin);
             mp_read_radix(&b, buf, 64);
             FGETS(buf, 4095, stdin);
             mp_read_radix(&c, buf, 64);
             mp_copy(&a, &d);
             mp_mul(&d, &b, &d);
             if (mp_cmp(&c, &d) != MP_EQ) {
                printf("mul %lu failure!\n", mul_n);
                draw(&a);
                draw(&b);
                draw(&c);
                draw(&d);
                return EXIT_FAILURE;
             }
          } else if (strcmp(cmd, "div") == 0) {
             ++div_n;
             FGETS(buf, 4095, stdin);
             mp_read_radix(&a, buf, 64);
             FGETS(buf, 4095, stdin);
             mp_read_radix(&b, buf, 64);
             FGETS(buf, 4095, stdin);
             mp_read_radix(&c, buf, 64);
             FGETS(buf, 4095, stdin);
             mp_read_radix(&d, buf, 64);
    
             mp_div(&a, &b, &e, &f);
             if ((mp_cmp(&c, &e) != MP_EQ) || (mp_cmp(&d, &f) != MP_EQ)) {
                printf("div %lu %d, %d, failure!\n", div_n, mp_cmp(&c, &e),
                       mp_cmp(&d, &f));
                draw(&a);
                draw(&b);
                draw(&c);
                draw(&d);
                draw(&e);
                draw(&f);
                return EXIT_FAILURE;
             }
    
          } else if (strcmp(cmd, "sqr") == 0) {
             ++sqr_n;
             FGETS(buf, 4095, stdin);
             mp_read_radix(&a, buf, 64);
             FGETS(buf, 4095, stdin);
             mp_read_radix(&b, buf, 64);
             mp_copy(&a, &c);
             mp_sqr(&c, &c);
             if (mp_cmp(&b, &c) != MP_EQ) {
                printf("sqr %lu failure!\n", sqr_n);
                draw(&a);
                draw(&b);
                draw(&c);
                return EXIT_FAILURE;
             }
          } else if (strcmp(cmd, "gcd") == 0) {
             ++gcd_n;
             FGETS(buf, 4095, stdin);
             mp_read_radix(&a, buf, 64);
             FGETS(buf, 4095, stdin);
             mp_read_radix(&b, buf, 64);
             FGETS(buf, 4095, stdin);
             mp_read_radix(&c, buf, 64);
             mp_copy(&a, &d);
             mp_gcd(&d, &b, &d);
             d.sign = c.sign;
             if (mp_cmp(&c, &d) != MP_EQ) {
                printf("gcd %lu failure!\n", gcd_n);
                draw(&a);
                draw(&b);
                draw(&c);
                draw(&d);
                return EXIT_FAILURE;
             }
          } else if (strcmp(cmd, "lcm") == 0) {
             ++lcm_n;
             FGETS(buf, 4095, stdin);
             mp_read_radix(&a, buf, 64);
             FGETS(buf, 4095, stdin);
             mp_read_radix(&b, buf, 64);
             FGETS(buf, 4095, stdin);
             mp_read_radix(&c, buf, 64);
             mp_copy(&a, &d);
             mp_lcm(&d, &b, &d);
             d.sign = c.sign;
             if (mp_cmp(&c, &d) != MP_EQ) {
                printf("lcm %lu failure!\n", lcm_n);
                draw(&a);
                draw(&b);
                draw(&c);
                draw(&d);
                return EXIT_FAILURE;
             }
          } else if (strcmp(cmd, "expt") == 0) {
             ++expt_n;
             FGETS(buf, 4095, stdin);
             mp_read_radix(&a, buf, 64);
             FGETS(buf, 4095, stdin);
             mp_read_radix(&b, buf, 64);
             FGETS(buf, 4095, stdin);
             mp_read_radix(&c, buf, 64);
             FGETS(buf, 4095, stdin);
             mp_read_radix(&d, buf, 64);
             mp_copy(&a, &e);
             mp_exptmod(&e, &b, &c, &e);
             if (mp_cmp(&d, &e) != MP_EQ) {
                printf("expt %lu failure!\n", expt_n);
                draw(&a);
                draw(&b);
                draw(&c);
                draw(&d);
                draw(&e);
                return EXIT_FAILURE;
             }
          } else if (strcmp(cmd, "invmod") == 0) {
             ++inv_n;
             FGETS(buf, 4095, stdin);
             mp_read_radix(&a, buf, 64);
             FGETS(buf, 4095, stdin);
             mp_read_radix(&b, buf, 64);
             FGETS(buf, 4095, stdin);
             mp_read_radix(&c, buf, 64);
             mp_invmod(&a, &b, &d);
             mp_mulmod(&d, &a, &b, &e);
             if (mp_cmp_d(&e, 1uL) != MP_EQ) {
                printf("inv [wrong value from MPI?!] failure\n");
                draw(&a);
                draw(&b);
                draw(&c);
                draw(&d);
                draw(&e);
                mp_gcd(&a, &b, &e);
                draw(&e);
                return EXIT_FAILURE;
             }
    
          } else if (strcmp(cmd, "div2") == 0) {
             ++div2_n;
             FGETS(buf, 4095, stdin);
             mp_read_radix(&a, buf, 64);
             FGETS(buf, 4095, stdin);
             mp_read_radix(&b, buf, 64);
             mp_div_2(&a, &c);
             if (mp_cmp(&c, &b) != MP_EQ) {
                printf("div_2 %lu failure\n", div2_n);
                draw(&a);
                draw(&b);
                draw(&c);
                return EXIT_FAILURE;
             }
          } else if (strcmp(cmd, "mul2") == 0) {
             ++mul2_n;
             FGETS(buf, 4095, stdin);
             mp_read_radix(&a, buf, 64);
             FGETS(buf, 4095, stdin);
             mp_read_radix(&b, buf, 64);
             mp_mul_2(&a, &c);
             if (mp_cmp(&c, &b) != MP_EQ) {
                printf("mul_2 %lu failure\n", mul2_n);
                draw(&a);
                draw(&b);
                draw(&c);
                return EXIT_FAILURE;
             }
          } else if (strcmp(cmd, "add_d") == 0) {
             ++add_d_n;
             FGETS(buf, 4095, stdin);
             mp_read_radix(&a, buf, 64);
             FGETS(buf, 4095, stdin);
             sscanf(buf, "%d", &ix);
             FGETS(buf, 4095, stdin);
             mp_read_radix(&b, buf, 64);
             mp_add_d(&a, ix, &c);
             if (mp_cmp(&b, &c) != MP_EQ) {
                printf("add_d %lu failure\n", add_d_n);
                draw(&a);
                draw(&b);
                draw(&c);
                printf("d == %d\n", ix);
                return EXIT_FAILURE;
             }
          } else if (strcmp(cmd, "sub_d") == 0) {
             ++sub_d_n;
             FGETS(buf, 4095, stdin);
             mp_read_radix(&a, buf, 64);
             FGETS(buf, 4095, stdin);
             sscanf(buf, "%d", &ix);
             FGETS(buf, 4095, stdin);
             mp_read_radix(&b, buf, 64);
             mp_sub_d(&a, ix, &c);
             if (mp_cmp(&b, &c) != MP_EQ) {
                printf("sub_d %lu failure\n", sub_d_n);
                draw(&a);
                draw(&b);
                draw(&c);
                printf("d == %d\n", ix);
                return EXIT_FAILURE;
             }
          } else if (strcmp(cmd, "exit") == 0) {
             printf("\nokay, exiting now\n");
             break;
          }
       }
    #endif
       return 0;
    }
    
    /* ref:         $Format:%D$ */
    /* git commit:  $Format:%H$ */
    /* commit time: $Format:%ai$ */