1//===-- Unittests for log -------------------------------------------------===//
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/__support/libc_errno.h"
12#include "src/math/log.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
19using LlvmLibcLogTest = LIBC_NAMESPACE::testing::FPTest<double>;
20
21namespace mpfr = LIBC_NAMESPACE::testing::mpfr;
22using LIBC_NAMESPACE::testing::tlog;
23
24TEST_F(LlvmLibcLogTest, SpecialNumbers) {
25 EXPECT_FP_EQ(aNaN, LIBC_NAMESPACE::log(aNaN));
26 EXPECT_FP_EQ(inf, LIBC_NAMESPACE::log(inf));
27 EXPECT_FP_IS_NAN_WITH_EXCEPTION(LIBC_NAMESPACE::log(neg_inf), FE_INVALID);
28 EXPECT_FP_EQ_WITH_EXCEPTION(neg_inf, LIBC_NAMESPACE::log(0.0), FE_DIVBYZERO);
29 EXPECT_FP_EQ_WITH_EXCEPTION(neg_inf, LIBC_NAMESPACE::log(-0.0), FE_DIVBYZERO);
30 EXPECT_FP_IS_NAN_WITH_EXCEPTION(LIBC_NAMESPACE::log(-1.0), FE_INVALID);
31 EXPECT_FP_EQ_ALL_ROUNDING(zero, LIBC_NAMESPACE::log(1.0));
32}
33
34TEST_F(LlvmLibcLogTest, TrickyInputs) {
35 constexpr int N = 30;
36 constexpr uint64_t INPUTS[N] = {
37 0x3ff0000000000000, // x = 1.0
38 0x4024000000000000, // x = 10.0
39 0x4059000000000000, // x = 10^2
40 0x408f400000000000, // x = 10^3
41 0x40c3880000000000, // x = 10^4
42 0x40f86a0000000000, // x = 10^5
43 0x412e848000000000, // x = 10^6
44 0x416312d000000000, // x = 10^7
45 0x4197d78400000000, // x = 10^8
46 0x41cdcd6500000000, // x = 10^9
47 0x4202a05f20000000, // x = 10^10
48 0x42374876e8000000, // x = 10^11
49 0x426d1a94a2000000, // x = 10^12
50 0x42a2309ce5400000, // x = 10^13
51 0x42d6bcc41e900000, // x = 10^14
52 0x430c6bf526340000, // x = 10^15
53 0x4341c37937e08000, // x = 10^16
54 0x4376345785d8a000, // x = 10^17
55 0x43abc16d674ec800, // x = 10^18
56 0x43e158e460913d00, // x = 10^19
57 0x4415af1d78b58c40, // x = 10^20
58 0x444b1ae4d6e2ef50, // x = 10^21
59 0x4480f0cf064dd592, // x = 10^22
60 0x3fefffffffef06ad, 0x3fefde0f22c7d0eb, 0x225e7812faadb32f,
61 0x3fee1076964c2903, 0x3fdfe93fff7fceb0, 0x3ff012631ad8df10,
62 0x3fefbfdaa448ed98,
63 };
64 for (int i = 0; i < N; ++i) {
65 double x = FPBits(INPUTS[i]).get_val();
66 EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Log, x,
67 LIBC_NAMESPACE::log(x), 0.5);
68 }
69}
70
71TEST_F(LlvmLibcLogTest, AllExponents) {
72 double x = 0x1.0p-1074;
73 for (int i = -1074; i < 1024; ++i, x *= 2.0) {
74 ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Log, x,
75 LIBC_NAMESPACE::log(x), 0.5);
76 }
77}
78
79TEST_F(LlvmLibcLogTest, InDoubleRange) {
80 constexpr uint64_t COUNT = 234561;
81 constexpr uint64_t START = 0x3FD0'0000'0000'0000ULL; // 0.25
82 constexpr uint64_t STOP = 0x4010'0000'0000'0000ULL; // 4.0
83 // constexpr uint64_t START = 0x3FF0'0000'0000'0000ULL; // 1.0
84 // constexpr uint64_t STOP = 0x4000'0000'0000'0000ULL; // 2.0
85 constexpr uint64_t STEP = (STOP - START) / COUNT;
86
87 auto test = [&](mpfr::RoundingMode rounding_mode) {
88 mpfr::ForceRoundingMode __r(rounding_mode);
89 if (!__r.success)
90 return;
91
92 uint64_t fails = 0;
93 uint64_t count = 0;
94 uint64_t cc = 0;
95 double mx, mr = 0.0;
96 double tol = 0.5;
97
98 for (uint64_t i = 0, v = START; i <= COUNT; ++i, v += STEP) {
99 double x = FPBits(v).get_val();
100 if (FPBits(v).is_nan() || FPBits(v).is_inf() || x < 0.0)
101 continue;
102 libc_errno = 0;
103 double result = LIBC_NAMESPACE::log(x);
104 ++cc;
105 if (FPBits(result).is_nan() || FPBits(result).is_inf())
106 continue;
107
108 ++count;
109 // ASSERT_MPFR_MATCH(mpfr::Operation::Log, x, result, 0.5);
110 if (!TEST_MPFR_MATCH_ROUNDING_SILENTLY(mpfr::Operation::Log, x, result,
111 0.5, rounding_mode)) {
112 ++fails;
113 while (!TEST_MPFR_MATCH_ROUNDING_SILENTLY(mpfr::Operation::Log, x,
114 result, tol, rounding_mode)) {
115 mx = x;
116 mr = result;
117 tol *= 2.0;
118 }
119 }
120 }
121 tlog << " Log failed: " << fails << "/" << count << "/" << cc
122 << " tests.\n";
123 tlog << " Max ULPs is at most: " << static_cast<uint64_t>(tol) << ".\n";
124 if (fails) {
125 EXPECT_MPFR_MATCH(mpfr::Operation::Log, mx, mr, 0.5, rounding_mode);
126 }
127 };
128
129 tlog << " Test Rounding To Nearest...\n";
130 test(mpfr::RoundingMode::Nearest);
131
132 tlog << " Test Rounding Downward...\n";
133 test(mpfr::RoundingMode::Downward);
134
135 tlog << " Test Rounding Upward...\n";
136 test(mpfr::RoundingMode::Upward);
137
138 tlog << " Test Rounding Toward Zero...\n";
139 test(mpfr::RoundingMode::TowardZero);
140}
141

source code of libc/test/src/math/log_test.cpp