xref: /aosp_15_r20/external/llvm-libc/test/src/math/log10_test.cpp (revision 71db0c75aadcf003ffe3238005f61d7618a3fead)
1 //===-- Unittests for log10 -----------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "hdr/math_macros.h"
10 #include "src/__support/FPUtil/FPBits.h"
11 #include "src/errno/libc_errno.h"
12 #include "src/math/log10.h"
13 #include "test/UnitTest/FPMatcher.h"
14 #include "test/UnitTest/Test.h"
15 #include "utils/MPFRWrapper/MPFRUtils.h"
16 
17 #include <stdint.h>
18 
19 using LlvmLibcLog10Test = LIBC_NAMESPACE::testing::FPTest<double>;
20 
21 namespace mpfr = LIBC_NAMESPACE::testing::mpfr;
22 using LIBC_NAMESPACE::testing::tlog;
23 
TEST_F(LlvmLibcLog10Test,SpecialNumbers)24 TEST_F(LlvmLibcLog10Test, SpecialNumbers) {
25   EXPECT_FP_EQ(aNaN, LIBC_NAMESPACE::log10(aNaN));
26   EXPECT_FP_EQ(inf, LIBC_NAMESPACE::log10(inf));
27   EXPECT_FP_IS_NAN_WITH_EXCEPTION(LIBC_NAMESPACE::log10(neg_inf), FE_INVALID);
28   EXPECT_FP_EQ_WITH_EXCEPTION(neg_inf, LIBC_NAMESPACE::log10(0.0),
29                               FE_DIVBYZERO);
30   EXPECT_FP_EQ_WITH_EXCEPTION(neg_inf, LIBC_NAMESPACE::log10(-0.0),
31                               FE_DIVBYZERO);
32   EXPECT_FP_IS_NAN_WITH_EXCEPTION(LIBC_NAMESPACE::log10(-1.0), FE_INVALID);
33   EXPECT_FP_EQ_ALL_ROUNDING(zero, LIBC_NAMESPACE::log10(1.0));
34 }
35 
TEST_F(LlvmLibcLog10Test,TrickyInputs)36 TEST_F(LlvmLibcLog10Test, TrickyInputs) {
37   constexpr int N = 36;
38   constexpr uint64_t INPUTS[N] = {
39       0x3ff0000000000000, // x = 1.0
40       0x4024000000000000, // x = 10.0
41       0x4059000000000000, // x = 10^2
42       0x408f400000000000, // x = 10^3
43       0x40c3880000000000, // x = 10^4
44       0x40f86a0000000000, // x = 10^5
45       0x412e848000000000, // x = 10^6
46       0x416312d000000000, // x = 10^7
47       0x4197d78400000000, // x = 10^8
48       0x41cdcd6500000000, // x = 10^9
49       0x4202a05f20000000, // x = 10^10
50       0x42374876e8000000, // x = 10^11
51       0x426d1a94a2000000, // x = 10^12
52       0x42a2309ce5400000, // x = 10^13
53       0x42d6bcc41e900000, // x = 10^14
54       0x430c6bf526340000, // x = 10^15
55       0x4341c37937e08000, // x = 10^16
56       0x4376345785d8a000, // x = 10^17
57       0x43abc16d674ec800, // x = 10^18
58       0x43e158e460913d00, // x = 10^19
59       0x4415af1d78b58c40, // x = 10^20
60       0x444b1ae4d6e2ef50, // x = 10^21
61       0x4480f0cf064dd592, // x = 10^22
62       0x3fefffffffef06ad, 0x3fefde0f22c7d0eb, 0x225e7812faadb32f,
63       0x3fee1076964c2903, 0x3fdfe93fff7fceb0, 0x3ff012631ad8df10,
64       0x3fefbfdaa448ed98, 0x44b0c9705a25ce02, 0x2c88d301065c7f9b,
65       0x30160580e7268a99, 0x5ca04103b7eaa345, 0x19ad77dc4a40093f,
66       0x0000449fb5c8a96e};
67   for (int i = 0; i < N; ++i) {
68     double x = FPBits(INPUTS[i]).get_val();
69     EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Log10, x,
70                                    LIBC_NAMESPACE::log10(x), 0.5);
71   }
72 }
73 
TEST_F(LlvmLibcLog10Test,AllExponents)74 TEST_F(LlvmLibcLog10Test, AllExponents) {
75   double x = 0x1.0p-1074;
76   for (int i = -1074; i < 1024; ++i, x *= 2.0) {
77     ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Log10, x,
78                                    LIBC_NAMESPACE::log10(x), 0.5);
79   }
80 }
81 
TEST_F(LlvmLibcLog10Test,InDoubleRange)82 TEST_F(LlvmLibcLog10Test, InDoubleRange) {
83   constexpr uint64_t COUNT = 1'001;
84   constexpr uint64_t START = 0x3FD0'0000'0000'0000ULL; // 0.25
85   constexpr uint64_t STOP = 0x4010'0000'0000'0000ULL;  // 4.0
86   // constexpr uint64_t START = 0x3FF0'0000'0000'0000ULL;  // 1.0
87   // constexpr uint64_t STOP = 0x4000'0000'0000'0000ULL;   // 2.0
88   constexpr uint64_t STEP = (STOP - START) / COUNT;
89 
90   auto test = [&](mpfr::RoundingMode rounding_mode) {
91     mpfr::ForceRoundingMode __r(rounding_mode);
92     if (!__r.success)
93       return;
94     uint64_t fails = 0;
95     uint64_t count = 0;
96     uint64_t cc = 0;
97     double mx, mr = 0.0;
98     double tol = 0.5;
99 
100     for (uint64_t i = 0, v = START; i <= COUNT; ++i, v += STEP) {
101       double x = FPBits(v).get_val();
102       if (FPBits(v).is_nan() || FPBits(v).is_inf() || x < 0.0)
103         continue;
104       LIBC_NAMESPACE::libc_errno = 0;
105       double result = LIBC_NAMESPACE::log10(x);
106       ++cc;
107       if (FPBits(result).is_nan() || FPBits(result).is_inf())
108         continue;
109 
110       ++count;
111       // ASSERT_MPFR_MATCH(mpfr::Operation::Log10, x, result, 0.5);
112       if (!TEST_MPFR_MATCH_ROUNDING_SILENTLY(mpfr::Operation::Log10, x, result,
113                                              0.5, rounding_mode)) {
114         ++fails;
115         while (!TEST_MPFR_MATCH_ROUNDING_SILENTLY(mpfr::Operation::Log10, x,
116                                                   result, tol, rounding_mode)) {
117           mx = x;
118           mr = result;
119           tol *= 2.0;
120         }
121       }
122     }
123     tlog << " Log10 failed: " << fails << "/" << count << "/" << cc
124          << " tests.\n";
125     tlog << "   Max ULPs is at most: " << static_cast<uint64_t>(tol) << ".\n";
126     if (fails) {
127       EXPECT_MPFR_MATCH(mpfr::Operation::Log10, mx, mr, 0.5, rounding_mode);
128     }
129   };
130 
131   tlog << " Test Rounding To Nearest...\n";
132   test(mpfr::RoundingMode::Nearest);
133 
134   tlog << " Test Rounding Downward...\n";
135   test(mpfr::RoundingMode::Downward);
136 
137   tlog << " Test Rounding Upward...\n";
138   test(mpfr::RoundingMode::Upward);
139 
140   tlog << " Test Rounding Toward Zero...\n";
141   test(mpfr::RoundingMode::TowardZero);
142 }
143