1//===-- Unittests for atan ------------------------------------------------===//
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 "src/__support/FPUtil/FPBits.h"
10#include "src/math/atan.h"
11#include "test/UnitTest/FPMatcher.h"
12#include "test/UnitTest/Test.h"
13#include "utils/MPFRWrapper/MPFRUtils.h"
14
15using LlvmLibcAtanTest = LIBC_NAMESPACE::testing::FPTest<double>;
16
17namespace mpfr = LIBC_NAMESPACE::testing::mpfr;
18
19using LIBC_NAMESPACE::testing::tlog;
20
21TEST_F(LlvmLibcAtanTest, InDoubleRange) {
22 constexpr uint64_t COUNT = 123'451;
23 uint64_t START = LIBC_NAMESPACE::fputil::FPBits<double>(0x1.0p-60).uintval();
24 uint64_t STOP = LIBC_NAMESPACE::fputil::FPBits<double>(0x1.0p60).uintval();
25 uint64_t STEP = (STOP - START) / COUNT;
26
27 auto test = [&](mpfr::RoundingMode rounding_mode) {
28 mpfr::ForceRoundingMode __r(rounding_mode);
29 if (!__r.success)
30 return;
31
32 uint64_t fails = 0;
33 uint64_t count = 0;
34 uint64_t cc = 0;
35 double mx, mr = 0.0;
36 double tol = 0.5;
37
38 for (uint64_t i = 0, v = START; i <= COUNT; ++i, v += STEP) {
39 double x = FPBits(v).get_val();
40 if (FPBits(v).is_nan() || FPBits(v).is_inf())
41 continue;
42 libc_errno = 0;
43 double result = LIBC_NAMESPACE::atan(x);
44 ++cc;
45 if (FPBits(result).is_nan() || FPBits(result).is_inf())
46 continue;
47
48 ++count;
49
50 if (!TEST_MPFR_MATCH_ROUNDING_SILENTLY(mpfr::Operation::Atan, x, result,
51 2.0, rounding_mode)) {
52 ++fails;
53 while (!TEST_MPFR_MATCH_ROUNDING_SILENTLY(mpfr::Operation::Atan, x,
54 result, tol, rounding_mode)) {
55 mx = x;
56 mr = result;
57
58 if (tol > 1000.0)
59 break;
60
61 tol *= 2.0;
62 }
63 }
64 }
65 if (fails) {
66 tlog << " Atan failed: " << fails << "/" << count << "/" << cc
67 << " tests.\n";
68 tlog << " Max ULPs is at most: " << static_cast<uint64_t>(tol) << ".\n";
69 EXPECT_MPFR_MATCH(mpfr::Operation::Atan, mx, mr, 0.5, rounding_mode);
70 }
71 };
72
73 tlog << " Test Rounding To Nearest...\n";
74 test(mpfr::RoundingMode::Nearest);
75
76 tlog << " Test Rounding Downward...\n";
77 test(mpfr::RoundingMode::Downward);
78
79 tlog << " Test Rounding Upward...\n";
80 test(mpfr::RoundingMode::Upward);
81
82 tlog << " Test Rounding Toward Zero...\n";
83 test(mpfr::RoundingMode::TowardZero);
84}
85

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