add exp_bench.c.

src/exp_bench.c

@@ -0,0 +1,46 @@
+#include <assert.h>
+#include <stdio.h>
+
+#include <gmp.h>
+
+#include "entropy.h"
+#include "group.h"
+#include "timeit.h"
+
+int main()
+{
+  mpz_entropy_init();
+  group_init();
+  mpz_t test, expected, base;
+  uint64_t exp;
+  mpz_inits(test, expected, base, NULL);
+
+  mpz_t expected_mod;
+  mpz_inits(expected_mod, NULL);
+
+
+  mpz_urandomm(base, _rstate, p);
+  mpz_powm_ui(expected_mod, base, 2, p);
+  mpz_pow_ui(test, base, 2);
+  remp(test);
+  // gmp_printf("%Zx\n%Zx\n", test, expected_mod);
+  assert(!mpz_cmp(test, expected_mod));
+  mpz_clear(expected_mod);
+
+  INIT_TIMEIT(CLOCK_PROCESS_CPUTIME_ID);
+  for (int i = 0; i < (int) 1e4; i++) {
+    getrandom(&exp, 4, GRND_NONBLOCK);
+    mpz_urandomm(base, _rstate, p);
+
+    mpz_powm_ui(expected, base, exp, p);
+    mpz_set(test, base);
+    START_TIMEIT();
+    powmp_ui(test, test, exp);
+    END_TIMEIT();
+
+    assert(!mpz_cmp(test, expected));
+  }
+
+  printf(TIMEIT_FORMAT "\n", GET_TIMEIT());
+  mpz_clears(test, expected, base, NULL);
+}