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hush3/src/snark/libsnark/algebra/fields/tests/test_bigint.cpp

97 lines
3.0 KiB
C++

/**
*****************************************************************************
* @author This file is part of libsnark, developed by SCIPR Lab
* and contributors (see AUTHORS).
* @copyright MIT license (see LICENSE file)
*****************************************************************************/
#include "algebra/fields/bigint.hpp"
#include <gtest/gtest.h>
using namespace libsnark;
TEST(algebra, bigint)
{
static_assert(GMP_NUMB_BITS == 64, "GMP limb not 64-bit");
const char *b1_decimal = "76749407";
const char *b2_decimal = "435020359732196472065729437602";
const char *b3_decimal = "33387554642372758038536799358397002014";
const char *b2_binary = "0000000000000000000000000000010101111101101000000110100001011010"
"1101101010001001000001101000101000100110011001110001111110100010";
bigint<1> b0 = bigint<1>(UINT64_C(0));
bigint<1> b1 = bigint<1>(b1_decimal);
bigint<2> b2 = bigint<2>(b2_decimal);
EXPECT_EQ(b0.as_uint64(), UINT64_C(0));
EXPECT_TRUE(b0.is_zero());
EXPECT_EQ(b1.as_uint64(), UINT64_C(76749407));
EXPECT_FALSE(b1.is_zero());
EXPECT_EQ(b2.as_uint64(), UINT64_C(15747124762497195938));
EXPECT_FALSE(b2.is_zero());
EXPECT_NE(b0, b1);
EXPECT_FALSE(b0 == b1);
EXPECT_EQ(b2.max_bits(), 128u);
EXPECT_EQ(b2.num_bits(), 99u);
for (size_t i = 0; i < 128; i++) {
EXPECT_EQ(b2.test_bit(i), (b2_binary[127-i] == '1'));
}
bigint<3> b3 = b2 * b1;
EXPECT_EQ(b3, bigint<3>(b3_decimal));
EXPECT_FALSE(b3.is_zero());
bigint<3> b3a { b3 };
EXPECT_EQ(b3a, bigint<3>(b3_decimal));
EXPECT_EQ(b3a, b3);
EXPECT_FALSE(b3a.is_zero());
mpz_t m3;
mpz_init(m3);
b3.to_mpz(m3);
bigint<3> b3b { m3 };
EXPECT_EQ(b3b, b3);
bigint<2> quotient;
bigint<2> remainder;
bigint<3>::div_qr(quotient, remainder, b3, b2);
EXPECT_LT(quotient.num_bits(), static_cast<size_t>(GMP_NUMB_BITS));
EXPECT_EQ(quotient.as_uint64(), b1.as_uint64());
bigint<1> b1inc = bigint<1>("76749408");
bigint<1> b1a = quotient.shorten(b1inc, "test");
EXPECT_EQ(b1a, b1);
EXPECT_TRUE(remainder.is_zero());
remainder.limit(b2, "test");
EXPECT_THROW((void)(quotient.shorten(b1, "test")), std::domain_error);
EXPECT_THROW(remainder.limit(remainder, "test"), std::domain_error);
bigint<1> br = bigint<1>("42");
b3 += br;
EXPECT_NE(b3, b3a);
EXPECT_GT(b3, b3a);
EXPECT_FALSE(b3a > b3);
bigint<3>::div_qr(quotient, remainder, b3, b2);
EXPECT_LT(quotient.num_bits(), static_cast<size_t>(GMP_NUMB_BITS));
EXPECT_EQ(quotient.as_uint64(), b1.as_uint64());
EXPECT_LT(remainder.num_bits(), static_cast<size_t>(GMP_NUMB_BITS));
EXPECT_EQ(remainder.as_uint64(), 42u);
b3a.clear();
EXPECT_TRUE(b3a.is_zero());
EXPECT_EQ(b3a.num_bits(), 0u);
EXPECT_FALSE(b3.is_zero());
bigint<4> bx = bigint<4>().randomize();
bigint<4> by = bigint<4>().randomize();
EXPECT_FALSE(bx == by);
// TODO: test serialization
}