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| 1 | +// Copyright (c) 2014-2020 The Bitcoin Core developers |
| 2 | +// Distributed under the MIT software license, see the accompanying |
| 3 | +// file COPYING or http://www.opensource.org/licenses/mit-license.php. |
| 4 | + |
| 5 | +#include <hash.h> |
| 6 | +#include <test/util/setup_common.h> |
| 7 | +#include <util/serfloat.h> |
| 8 | +#include <serialize.h> |
| 9 | +#include <streams.h> |
| 10 | + |
| 11 | +#include <boost/test/unit_test.hpp> |
| 12 | + |
| 13 | +#include <cmath> |
| 14 | +#include <limits> |
| 15 | + |
| 16 | +BOOST_FIXTURE_TEST_SUITE(serfloat_tests, BasicTestingSetup) |
| 17 | + |
| 18 | +namespace { |
| 19 | + |
| 20 | +uint64_t TestDouble(double f) { |
| 21 | + uint64_t i = EncodeDouble(f); |
| 22 | + double f2 = DecodeDouble(i); |
| 23 | + if (std::isnan(f)) { |
| 24 | + // NaN is not guaranteed to round-trip exactly. |
| 25 | + BOOST_CHECK(std::isnan(f2)); |
| 26 | + } else { |
| 27 | + // Everything else is. |
| 28 | + BOOST_CHECK(!std::isnan(f2)); |
| 29 | + uint64_t i2 = EncodeDouble(f2); |
| 30 | + BOOST_CHECK_EQUAL(f, f2); |
| 31 | + BOOST_CHECK_EQUAL(i, i2); |
| 32 | + } |
| 33 | + return i; |
| 34 | +} |
| 35 | + |
| 36 | +} // namespace |
| 37 | + |
| 38 | +BOOST_AUTO_TEST_CASE(double_serfloat_tests) { |
| 39 | + BOOST_CHECK_EQUAL(TestDouble(0.0), 0); |
| 40 | + BOOST_CHECK_EQUAL(TestDouble(-0.0), 0x8000000000000000); |
| 41 | + BOOST_CHECK_EQUAL(TestDouble(std::numeric_limits<double>::infinity()), 0x7ff0000000000000); |
| 42 | + BOOST_CHECK_EQUAL(TestDouble(-std::numeric_limits<double>::infinity()), 0xfff0000000000000); |
| 43 | + BOOST_CHECK_EQUAL(TestDouble(0.5), 0x3fe0000000000000ULL); |
| 44 | + BOOST_CHECK_EQUAL(TestDouble(1.0), 0x3ff0000000000000ULL); |
| 45 | + BOOST_CHECK_EQUAL(TestDouble(2.0), 0x4000000000000000ULL); |
| 46 | + BOOST_CHECK_EQUAL(TestDouble(4.0), 0x4010000000000000ULL); |
| 47 | + BOOST_CHECK_EQUAL(TestDouble(785.066650390625), 0x4088888880000000ULL); |
| 48 | + |
| 49 | + // Roundtrip test on IEC559-compatible systems |
| 50 | + if (std::numeric_limits<double>::is_iec559) { |
| 51 | + BOOST_CHECK_EQUAL(sizeof(double), 8); |
| 52 | + BOOST_CHECK_EQUAL(sizeof(uint64_t), 8); |
| 53 | + // Test extreme values |
| 54 | + TestDouble(std::numeric_limits<double>::min()); |
| 55 | + TestDouble(-std::numeric_limits<double>::min()); |
| 56 | + TestDouble(std::numeric_limits<double>::max()); |
| 57 | + TestDouble(-std::numeric_limits<double>::max()); |
| 58 | + TestDouble(std::numeric_limits<double>::lowest()); |
| 59 | + TestDouble(-std::numeric_limits<double>::lowest()); |
| 60 | + TestDouble(std::numeric_limits<double>::quiet_NaN()); |
| 61 | + TestDouble(-std::numeric_limits<double>::quiet_NaN()); |
| 62 | + TestDouble(std::numeric_limits<double>::signaling_NaN()); |
| 63 | + TestDouble(-std::numeric_limits<double>::signaling_NaN()); |
| 64 | + TestDouble(std::numeric_limits<double>::denorm_min()); |
| 65 | + TestDouble(-std::numeric_limits<double>::denorm_min()); |
| 66 | + // Test exact encoding: on currently supported platforms, EncodeDouble |
| 67 | + // should produce exactly the same as the in-memory representation for non-NaN. |
| 68 | + for (int j = 0; j < 1000; ++j) { |
| 69 | + // Iterate over 9 specific bits exhaustively; the others are chosen randomly. |
| 70 | + // These specific bits are the sign bit, and the 2 top and bottom bits of |
| 71 | + // exponent and mantissa in the IEEE754 binary64 format. |
| 72 | + for (int x = 0; x < 512; ++x) { |
| 73 | + uint64_t v = InsecureRandBits(64); |
| 74 | + v &= ~(uint64_t{1} << 0); |
| 75 | + if (x & 1) v |= (uint64_t{1} << 0); |
| 76 | + v &= ~(uint64_t{1} << 1); |
| 77 | + if (x & 2) v |= (uint64_t{1} << 1); |
| 78 | + v &= ~(uint64_t{1} << 50); |
| 79 | + if (x & 4) v |= (uint64_t{1} << 50); |
| 80 | + v &= ~(uint64_t{1} << 51); |
| 81 | + if (x & 8) v |= (uint64_t{1} << 51); |
| 82 | + v &= ~(uint64_t{1} << 52); |
| 83 | + if (x & 16) v |= (uint64_t{1} << 52); |
| 84 | + v &= ~(uint64_t{1} << 53); |
| 85 | + if (x & 32) v |= (uint64_t{1} << 53); |
| 86 | + v &= ~(uint64_t{1} << 61); |
| 87 | + if (x & 64) v |= (uint64_t{1} << 61); |
| 88 | + v &= ~(uint64_t{1} << 62); |
| 89 | + if (x & 128) v |= (uint64_t{1} << 62); |
| 90 | + v &= ~(uint64_t{1} << 63); |
| 91 | + if (x & 256) v |= (uint64_t{1} << 63); |
| 92 | + double f; |
| 93 | + memcpy(&f, &v, 8); |
| 94 | + uint64_t v2 = TestDouble(f); |
| 95 | + if (!std::isnan(f)) BOOST_CHECK_EQUAL(v, v2); |
| 96 | + } |
| 97 | + } |
| 98 | + } |
| 99 | +} |
| 100 | + |
| 101 | +/* |
| 102 | +Python code to generate the below hashes: |
| 103 | +
|
| 104 | + def reversed_hex(x): |
| 105 | + return binascii.hexlify(''.join(reversed(x))) |
| 106 | + def dsha256(x): |
| 107 | + return hashlib.sha256(hashlib.sha256(x).digest()).digest() |
| 108 | +
|
| 109 | + reversed_hex(dsha256(''.join(struct.pack('<d', x) for x in range(0,1000)))) == '43d0c82591953c4eafe114590d392676a01585d25b25d433557f0d7878b23f96' |
| 110 | +*/ |
| 111 | +BOOST_AUTO_TEST_CASE(doubles) |
| 112 | +{ |
| 113 | + CDataStream ss(SER_DISK, 0); |
| 114 | + // encode |
| 115 | + for (int i = 0; i < 1000; i++) { |
| 116 | + ss << EncodeDouble(i); |
| 117 | + } |
| 118 | + BOOST_CHECK(Hash(ss) == uint256S("43d0c82591953c4eafe114590d392676a01585d25b25d433557f0d7878b23f96")); |
| 119 | + |
| 120 | + // decode |
| 121 | + for (int i = 0; i < 1000; i++) { |
| 122 | + uint64_t val; |
| 123 | + ss >> val; |
| 124 | + double j = DecodeDouble(val); |
| 125 | + BOOST_CHECK_MESSAGE(i == j, "decoded:" << j << " expected:" << i); |
| 126 | + } |
| 127 | +} |
| 128 | + |
| 129 | +BOOST_AUTO_TEST_SUITE_END() |
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