1//===-- Unittests for log1p -----------------------------------------------===//
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/log1p.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 LlvmLibcLog1pTest = LIBC_NAMESPACE::testing::FPTest<double>;
20
21namespace mpfr = LIBC_NAMESPACE::testing::mpfr;
22using LIBC_NAMESPACE::testing::tlog;
23
24TEST_F(LlvmLibcLog1pTest, SpecialNumbers) {
25 EXPECT_FP_EQ(aNaN, LIBC_NAMESPACE::log1p(aNaN));
26 EXPECT_FP_EQ(inf, LIBC_NAMESPACE::log1p(inf));
27 EXPECT_FP_IS_NAN_WITH_EXCEPTION(LIBC_NAMESPACE::log1p(neg_inf), FE_INVALID);
28 EXPECT_FP_IS_NAN_WITH_EXCEPTION(LIBC_NAMESPACE::log1p(-2.0), FE_INVALID);
29 EXPECT_FP_EQ(zero, LIBC_NAMESPACE::log1p(0.0));
30 EXPECT_FP_EQ(neg_zero, LIBC_NAMESPACE::log1p(-0.0));
31 EXPECT_FP_EQ_WITH_EXCEPTION(neg_inf, LIBC_NAMESPACE::log1p(-1.0),
32 FE_DIVBYZERO);
33}
34
35TEST_F(LlvmLibcLog1pTest, TrickyInputs) {
36 constexpr int N = 42;
37 constexpr uint64_t INPUTS[N] = {
38 0x3ff0000000000000, // x = 1.0
39 0x4024000000000000, // x = 10.0
40 0x4059000000000000, // x = 10^2
41 0x408f400000000000, // x = 10^3
42 0x40c3880000000000, // x = 10^4
43 0x40f86a0000000000, // x = 10^5
44 0x412e848000000000, // x = 10^6
45 0x416312d000000000, // x = 10^7
46 0x4197d78400000000, // x = 10^8
47 0x41cdcd6500000000, // x = 10^9
48 0x4202a05f20000000, // x = 10^10
49 0x42374876e8000000, // x = 10^11
50 0x426d1a94a2000000, // x = 10^12
51 0x42a2309ce5400000, // x = 10^13
52 0x42d6bcc41e900000, // x = 10^14
53 0x430c6bf526340000, // x = 10^15
54 0x4341c37937e08000, // x = 10^16
55 0x4376345785d8a000, // x = 10^17
56 0x43abc16d674ec800, // x = 10^18
57 0x43e158e460913d00, // x = 10^19
58 0x4415af1d78b58c40, // x = 10^20
59 0x444b1ae4d6e2ef50, // x = 10^21
60 0x4480f0cf064dd592, // x = 10^22
61 0x3fefffffffef06ad, 0x3fefde0f22c7d0eb, 0x225e7812faadb32f,
62 0x3fee1076964c2903, 0x3fdfe93fff7fceb0, 0x3ff012631ad8df10,
63 0x3fefbfdaa448ed98, 0x3fd00a8cefe9a5f8, 0x3fd0b4d870eb22f8,
64 0x3c90c40cef04efb5, 0x449d2ccad399848e, 0x4aa12ccdffd9d2ec,
65 0x5656f070b92d36ce, 0x6db06dcb74f76bcc, 0x7f1954e72ffd4596,
66 0x5671e2f1628093e4, 0x73dac56e2bf1a951, 0x8001bc6879ea14c5,
67 0x45ca5f497ec291df, // x = 0x1.a5f497ec291dfp+93
68 };
69 for (int i = 0; i < N; ++i) {
70 double x = FPBits(INPUTS[i]).get_val();
71 EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Log1p, x,
72 LIBC_NAMESPACE::log1p(x), 0.5);
73 }
74}
75
76TEST_F(LlvmLibcLog1pTest, AllExponents) {
77 double x = 0x1.0p-1074;
78 for (int i = -1074; i < 1024; ++i, x *= 2.0) {
79 ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Log1p, x,
80 LIBC_NAMESPACE::log1p(x), 0.5);
81 }
82}
83
84TEST_F(LlvmLibcLog1pTest, InDoubleRange) {
85 constexpr uint64_t COUNT = 4501;
86
87 auto test = [&](uint64_t start, uint64_t stop,
88 mpfr::RoundingMode rounding_mode) {
89 mpfr::ForceRoundingMode __r(rounding_mode);
90 if (!__r.success)
91 return;
92
93 uint64_t fails = 0;
94 uint64_t count = 0;
95 uint64_t cc = 0;
96 double mx, mr = 0.0;
97 double tol = 0.5;
98
99 uint64_t step = (stop - start) / COUNT;
100
101 for (uint64_t i = 0, v = start; i <= COUNT; ++i, v += step) {
102 double x = FPBits(v).get_val();
103 if (FPBits(v).is_nan() || FPBits(v).is_inf() || x < 0.0)
104 continue;
105 libc_errno = 0;
106 double result = LIBC_NAMESPACE::log1p(x);
107 ++cc;
108 if (FPBits(result).is_nan() || FPBits(result).is_inf())
109 continue;
110
111 ++count;
112 // ASSERT_MPFR_MATCH(mpfr::Operation::Log1p, x, result, 0.5);
113 if (!TEST_MPFR_MATCH_ROUNDING_SILENTLY(mpfr::Operation::Log1p, x, result,
114 0.5, rounding_mode)) {
115 ++fails;
116 while (!TEST_MPFR_MATCH_ROUNDING_SILENTLY(mpfr::Operation::Log1p, x,
117 result, tol, rounding_mode)) {
118 mx = x;
119 mr = result;
120 tol *= 2.0;
121 }
122 }
123 }
124 tlog << " Log1p failed: " << fails << "/" << count << "/" << cc
125 << " tests.\n";
126 tlog << " Max ULPs is at most: " << static_cast<uint64_t>(tol) << ".\n";
127 if (fails) {
128 EXPECT_MPFR_MATCH(mpfr::Operation::Log1p, mx, mr, 0.5, rounding_mode);
129 }
130 };
131
132 auto test_all_rounding = [&](uint64_t start, uint64_t stop,
133 const char *start_str, const char *stop_str) {
134 tlog << "\n=== Test in range [" << start_str << ", " << stop_str
135 << "] ===\n";
136
137 tlog << "\n Test Rounding To Nearest...\n";
138 test(start, stop, mpfr::RoundingMode::Nearest);
139
140 tlog << "\n Test Rounding Downward...\n";
141 test(start, stop, mpfr::RoundingMode::Downward);
142
143 tlog << "\n Test Rounding Upward...\n";
144 test(start, stop, mpfr::RoundingMode::Upward);
145
146 tlog << "\n Test Rounding Toward Zero...\n";
147 test(start, stop, mpfr::RoundingMode::TowardZero);
148 };
149
150 test_all_rounding(0x0000'0000'0000'0001ULL, 0x0010'0000'0000'0000ULL,
151 "2^-1074", "2^-1022");
152
153 test_all_rounding(0x39B0'0000'0000'0000ULL, 0x3A50'0000'0000'0000ULL,
154 "2^-100", "2^-90");
155
156 test_all_rounding(0x3CD0'0000'0000'0000ULL, 0x3D20'0000'0000'0000ULL, "2^-50",
157 "2^-45");
158
159 test_all_rounding(0x3E10'0000'0000'0000ULL, 0x3E40'0000'0000'0000ULL, "2^-30",
160 "2^-27");
161
162 test_all_rounding(0x3FD0'0000'0000'0000ULL, 0x4010'0000'0000'0000ULL, "0.25",
163 "4.0");
164
165 test_all_rounding(0x4630'0000'0000'0000ULL, 0x4670'0000'0000'0000ULL, "2^100",
166 "2^104");
167
168 test_all_rounding(0x7FD0'0000'0000'0000ULL, 0x7FF0'0000'0000'0000ULL,
169 "2^1022", "2^1024");
170}
171

source code of libc/test/src/math/log1p_test.cpp