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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:45:59 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:45:59 +0000
commit19fcec84d8d7d21e796c7624e521b60d28ee21ed (patch)
tree42d26aa27d1e3f7c0b8bd3fd14e7d7082f5008dc /src/rapidjson/test/unittest/strtodtest.cpp
parentInitial commit. (diff)
downloadceph-upstream/16.2.11+ds.tar.xz
ceph-upstream/16.2.11+ds.zip
Adding upstream version 16.2.11+ds.upstream/16.2.11+dsupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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diff --git a/src/rapidjson/test/unittest/strtodtest.cpp b/src/rapidjson/test/unittest/strtodtest.cpp
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+// 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. All rights reserved.
+//
+// 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