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Diffstat (limited to 'src/s3select/rapidjson/test/unittest/strtodtest.cpp')
-rw-r--r-- | src/s3select/rapidjson/test/unittest/strtodtest.cpp | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/src/s3select/rapidjson/test/unittest/strtodtest.cpp b/src/s3select/rapidjson/test/unittest/strtodtest.cpp new file mode 100644 index 000000000..66167a4a3 --- /dev/null +++ b/src/s3select/rapidjson/test/unittest/strtodtest.cpp @@ -0,0 +1,132 @@ +// Tencent is pleased to support the open source community by making RapidJSON available. +// +// Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip. +// +// Licensed under the MIT License (the "License"); you may not use this file except +// in compliance with the License. You may obtain a copy of the License at +// +// http://opensource.org/licenses/MIT +// +// Unless required by applicable law or agreed to in writing, software distributed +// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR +// CONDITIONS OF ANY KIND, either express or implied. See the License for the +// specific language governing permissions and limitations under the License. + +#include "unittest.h" + +#include "rapidjson/internal/strtod.h" + +#ifdef __clang__ +RAPIDJSON_DIAG_PUSH +RAPIDJSON_DIAG_OFF(unreachable-code) +#endif + +#define BIGINTEGER_LITERAL(s) BigInteger(s, sizeof(s) - 1) + +using namespace rapidjson::internal; + +TEST(Strtod, CheckApproximationCase) { + static const int kSignificandSize = 52; + static const int kExponentBias = 0x3FF; + static const uint64_t kExponentMask = RAPIDJSON_UINT64_C2(0x7FF00000, 0x00000000); + static const uint64_t kSignificandMask = RAPIDJSON_UINT64_C2(0x000FFFFF, 0xFFFFFFFF); + static const uint64_t kHiddenBit = RAPIDJSON_UINT64_C2(0x00100000, 0x00000000); + + // http://www.exploringbinary.com/using-integers-to-check-a-floating-point-approximation/ + // Let b = 0x1.465a72e467d88p-149 + // = 5741268244528520 x 2^-201 + union { + double d; + uint64_t u; + }u; + u.u = 0x465a72e467d88 | ((static_cast<uint64_t>(-149 + kExponentBias)) << kSignificandSize); + const double b = u.d; + const uint64_t bInt = (u.u & kSignificandMask) | kHiddenBit; + const int bExp = static_cast<int>(((u.u & kExponentMask) >> kSignificandSize) - kExponentBias - kSignificandSize); + EXPECT_DOUBLE_EQ(1.7864e-45, b); + EXPECT_EQ(RAPIDJSON_UINT64_C2(0x001465a7, 0x2e467d88), bInt); + EXPECT_EQ(-201, bExp); + + // Let d = 17864 x 10-49 + const char dInt[] = "17864"; + const int dExp = -49; + + // Let h = 2^(bExp-1) + const int hExp = bExp - 1; + EXPECT_EQ(-202, hExp); + + int dS_Exp2 = 0; + int dS_Exp5 = 0; + int bS_Exp2 = 0; + int bS_Exp5 = 0; + int hS_Exp2 = 0; + int hS_Exp5 = 0; + + // Adjust for decimal exponent + if (dExp >= 0) { + dS_Exp2 += dExp; + dS_Exp5 += dExp; + } + else { + bS_Exp2 -= dExp; + bS_Exp5 -= dExp; + hS_Exp2 -= dExp; + hS_Exp5 -= dExp; + } + + // Adjust for binary exponent + if (bExp >= 0) + bS_Exp2 += bExp; + else { + dS_Exp2 -= bExp; + hS_Exp2 -= bExp; + } + + // Adjust for half ulp exponent + if (hExp >= 0) + hS_Exp2 += hExp; + else { + dS_Exp2 -= hExp; + bS_Exp2 -= hExp; + } + + // Remove common power of two factor from all three scaled values + int common_Exp2 = (std::min)(dS_Exp2, (std::min)(bS_Exp2, hS_Exp2)); + dS_Exp2 -= common_Exp2; + bS_Exp2 -= common_Exp2; + hS_Exp2 -= common_Exp2; + + EXPECT_EQ(153, dS_Exp2); + EXPECT_EQ(0, dS_Exp5); + EXPECT_EQ(1, bS_Exp2); + EXPECT_EQ(49, bS_Exp5); + EXPECT_EQ(0, hS_Exp2); + EXPECT_EQ(49, hS_Exp5); + + BigInteger dS = BIGINTEGER_LITERAL(dInt); + dS.MultiplyPow5(static_cast<unsigned>(dS_Exp5)) <<= static_cast<size_t>(dS_Exp2); + + BigInteger bS(bInt); + bS.MultiplyPow5(static_cast<unsigned>(bS_Exp5)) <<= static_cast<size_t>(bS_Exp2); + + BigInteger hS(1); + hS.MultiplyPow5(static_cast<unsigned>(hS_Exp5)) <<= static_cast<size_t>(hS_Exp2); + + EXPECT_TRUE(BIGINTEGER_LITERAL("203970822259994138521801764465966248930731085529088") == dS); + EXPECT_TRUE(BIGINTEGER_LITERAL("203970822259994122305215569213032722473144531250000") == bS); + EXPECT_TRUE(BIGINTEGER_LITERAL("17763568394002504646778106689453125") == hS); + + EXPECT_EQ(1, dS.Compare(bS)); + + BigInteger delta(0); + EXPECT_FALSE(dS.Difference(bS, &delta)); + EXPECT_TRUE(BIGINTEGER_LITERAL("16216586195252933526457586554279088") == delta); + EXPECT_TRUE(bS.Difference(dS, &delta)); + EXPECT_TRUE(BIGINTEGER_LITERAL("16216586195252933526457586554279088") == delta); + + EXPECT_EQ(-1, delta.Compare(hS)); +} + +#ifdef __clang__ +RAPIDJSON_DIAG_POP +#endif |