aboutsummaryrefslogtreecommitdiff
path: root/libc/test/src/math/log1p_test.cpp
blob: b677e7b416e1a6cade12524fa861500ed4df8df9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
//===-- Unittests for log1p -----------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#include "src/__support/FPUtil/FPBits.h"
#include "src/errno/libc_errno.h"
#include "src/math/log1p.h"
#include "test/UnitTest/FPMatcher.h"
#include "test/UnitTest/Test.h"
#include "utils/MPFRWrapper/MPFRUtils.h"
#include <math.h>

#include <errno.h>
#include <stdint.h>

namespace mpfr = LIBC_NAMESPACE::testing::mpfr;
using LIBC_NAMESPACE::testing::tlog;

DECLARE_SPECIAL_CONSTANTS(double)

TEST(LlvmLibcLog1pTest, SpecialNumbers) {
  EXPECT_FP_EQ(aNaN, LIBC_NAMESPACE::log1p(aNaN));
  EXPECT_FP_EQ(inf, LIBC_NAMESPACE::log1p(inf));
  EXPECT_FP_IS_NAN_WITH_EXCEPTION(LIBC_NAMESPACE::log1p(neg_inf), FE_INVALID);
  EXPECT_FP_IS_NAN_WITH_EXCEPTION(LIBC_NAMESPACE::log1p(-2.0), FE_INVALID);
  EXPECT_FP_EQ(zero, LIBC_NAMESPACE::log1p(0.0));
  EXPECT_FP_EQ(neg_zero, LIBC_NAMESPACE::log1p(-0.0));
  EXPECT_FP_EQ_WITH_EXCEPTION(neg_inf, LIBC_NAMESPACE::log1p(-1.0),
                              FE_DIVBYZERO);
}

TEST(LlvmLibcLog1pTest, TrickyInputs) {
  constexpr int N = 41;
  constexpr uint64_t INPUTS[N] = {
      0x3ff0000000000000, // x = 1.0
      0x4024000000000000, // x = 10.0
      0x4059000000000000, // x = 10^2
      0x408f400000000000, // x = 10^3
      0x40c3880000000000, // x = 10^4
      0x40f86a0000000000, // x = 10^5
      0x412e848000000000, // x = 10^6
      0x416312d000000000, // x = 10^7
      0x4197d78400000000, // x = 10^8
      0x41cdcd6500000000, // x = 10^9
      0x4202a05f20000000, // x = 10^10
      0x42374876e8000000, // x = 10^11
      0x426d1a94a2000000, // x = 10^12
      0x42a2309ce5400000, // x = 10^13
      0x42d6bcc41e900000, // x = 10^14
      0x430c6bf526340000, // x = 10^15
      0x4341c37937e08000, // x = 10^16
      0x4376345785d8a000, // x = 10^17
      0x43abc16d674ec800, // x = 10^18
      0x43e158e460913d00, // x = 10^19
      0x4415af1d78b58c40, // x = 10^20
      0x444b1ae4d6e2ef50, // x = 10^21
      0x4480f0cf064dd592, // x = 10^22
      0x3fefffffffef06ad, 0x3fefde0f22c7d0eb, 0x225e7812faadb32f,
      0x3fee1076964c2903, 0x3fdfe93fff7fceb0, 0x3ff012631ad8df10,
      0x3fefbfdaa448ed98, 0x3fd00a8cefe9a5f8, 0x3fd0b4d870eb22f8,
      0x3c90c40cef04efb5, 0x449d2ccad399848e, 0x4aa12ccdffd9d2ec,
      0x5656f070b92d36ce, 0x6db06dcb74f76bcc, 0x7f1954e72ffd4596,
      0x5671e2f1628093e4, 0x73dac56e2bf1a951, 0x8001bc6879ea14c5,
  };
  for (int i = 0; i < N; ++i) {
    double x = double(FPBits(INPUTS[i]));
    EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Log1p, x,
                                   LIBC_NAMESPACE::log1p(x), 0.5);
  }
}

TEST(LlvmLibcLog1pTest, AllExponents) {
  double x = 0x1.0p-1074;
  for (int i = -1074; i < 1024; ++i, x *= 2.0) {
    ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Log1p, x,
                                   LIBC_NAMESPACE::log1p(x), 0.5);
  }
}

TEST(LlvmLibcLog1pTest, InDoubleRange) {
  constexpr uint64_t COUNT = 4501;

  auto test = [&](uint64_t start, uint64_t stop,
                  mpfr::RoundingMode rounding_mode) {
    mpfr::ForceRoundingMode __r(rounding_mode);
    if (!__r.success)
      return;

    uint64_t fails = 0;
    uint64_t count = 0;
    uint64_t cc = 0;
    double mx, mr = 0.0;
    double tol = 0.5;

    uint64_t step = (stop - start) / COUNT;

    for (uint64_t i = 0, v = start; i <= COUNT; ++i, v += step) {
      double x = FPBits(v).get_val();
      if (isnan(x) || isinf(x) || x < 0.0)
        continue;
      libc_errno = 0;
      double result = LIBC_NAMESPACE::log1p(x);
      ++cc;
      if (isnan(result) || isinf(result))
        continue;

      ++count;
      // ASSERT_MPFR_MATCH(mpfr::Operation::Log1p, x, result, 0.5);
      if (!TEST_MPFR_MATCH_ROUNDING_SILENTLY(mpfr::Operation::Log1p, x, result,
                                             0.5, rounding_mode)) {
        ++fails;
        while (!TEST_MPFR_MATCH_ROUNDING_SILENTLY(mpfr::Operation::Log1p, x,
                                                  result, tol, rounding_mode)) {
          mx = x;
          mr = result;
          tol *= 2.0;
        }
      }
    }
    tlog << " Log1p failed: " << fails << "/" << count << "/" << cc
         << " tests.\n";
    tlog << "   Max ULPs is at most: " << static_cast<uint64_t>(tol) << ".\n";
    if (fails) {
      EXPECT_MPFR_MATCH(mpfr::Operation::Log1p, mx, mr, 0.5, rounding_mode);
    }
  };

  auto test_all_rounding = [&](uint64_t start, uint64_t stop,
                               const char *start_str, const char *stop_str) {
    tlog << "\n=== Test in range [" << start_str << ", " << stop_str
         << "] ===\n";

    tlog << "\n Test Rounding To Nearest...\n";
    test(start, stop, mpfr::RoundingMode::Nearest);

    tlog << "\n Test Rounding Downward...\n";
    test(start, stop, mpfr::RoundingMode::Downward);

    tlog << "\n Test Rounding Upward...\n";
    test(start, stop, mpfr::RoundingMode::Upward);

    tlog << "\n Test Rounding Toward Zero...\n";
    test(start, stop, mpfr::RoundingMode::TowardZero);
  };

  test_all_rounding(0x0000'0000'0000'0001ULL, 0x0010'0000'0000'0000ULL,
                    "2^-1074", "2^-1022");

  test_all_rounding(0x39B0'0000'0000'0000ULL, 0x3A50'0000'0000'0000ULL,
                    "2^-100", "2^-90");

  test_all_rounding(0x3CD0'0000'0000'0000ULL, 0x3D20'0000'0000'0000ULL, "2^-50",
                    "2^-45");

  test_all_rounding(0x3E10'0000'0000'0000ULL, 0x3E40'0000'0000'0000ULL, "2^-30",
                    "2^-27");

  test_all_rounding(0x3FD0'0000'0000'0000ULL, 0x4010'0000'0000'0000ULL, "0.25",
                    "4.0");

  test_all_rounding(0x4630'0000'0000'0000ULL, 0x4670'0000'0000'0000ULL, "2^100",
                    "2^104");

  test_all_rounding(0x7FD0'0000'0000'0000ULL, 0x7FF0'0000'0000'0000ULL,
                    "2^1022", "2^1024");
}