1//===-- Unittests for erff ------------------------------------------------===//
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/math/erff.h"
12#include "test/UnitTest/FPMatcher.h"
13#include "test/UnitTest/Test.h"
14#include "utils/MPFRWrapper/MPFRUtils.h"
15
16#include <stdint.h>
17
18using LlvmLibcErffTest = LIBC_NAMESPACE::testing::FPTest<float>;
19
20namespace mpfr = LIBC_NAMESPACE::testing::mpfr;
21using LIBC_NAMESPACE::testing::tlog;
22
23TEST_F(LlvmLibcErffTest, SpecialNumbers) {
24 EXPECT_FP_EQ_ALL_ROUNDING(aNaN, LIBC_NAMESPACE::erff(aNaN));
25 EXPECT_FP_EQ_ALL_ROUNDING(1.0f, LIBC_NAMESPACE::erff(inf));
26 EXPECT_FP_EQ_ALL_ROUNDING(-1.0f, LIBC_NAMESPACE::erff(neg_inf));
27 EXPECT_FP_EQ_ALL_ROUNDING(zero, LIBC_NAMESPACE::erff(zero));
28 EXPECT_FP_EQ_ALL_ROUNDING(neg_zero, LIBC_NAMESPACE::erff(neg_zero));
29}
30
31TEST_F(LlvmLibcErffTest, TrickyInputs) {
32 constexpr int N = 2;
33 constexpr uint32_t INPUTS[N] = {
34 0x3f65'9229U, // |x| = 0x1.cb2452p-1f
35 0x4004'1e6aU, // |x| = 0x1.083cd4p+1f
36 };
37 for (int i = 0; i < N; ++i) {
38 float x = FPBits(INPUTS[i]).get_val();
39 EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Erf, x,
40 LIBC_NAMESPACE::erff(x), 0.5);
41 EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Erf, -x,
42 LIBC_NAMESPACE::erff(-x), 0.5);
43 }
44}
45
46TEST_F(LlvmLibcErffTest, InFloatRange) {
47 constexpr uint32_t COUNT = 234561;
48 constexpr uint32_t START = 0; // 0
49 constexpr uint32_t STOP = 0x4080'0000U; // 4.0f
50
51 constexpr uint64_t STEP = (STOP - START) / COUNT;
52
53 auto test = [&](mpfr::RoundingMode rounding_mode) {
54 mpfr::ForceRoundingMode __r(rounding_mode);
55 if (!__r.success)
56 return;
57
58 uint32_t fails = 0;
59 uint32_t count = 0;
60 uint32_t cc = 0;
61 float mx, mr = 0.0;
62 double tol = 0.5;
63
64 for (uint32_t i = 0, v = START; i <= COUNT; ++i, v += STEP) {
65 float x = FPBits(v).get_val();
66 if (FPBits(v).is_nan())
67 continue;
68
69 float result = LIBC_NAMESPACE::erff(x);
70 ++cc;
71 if (FPBits(result).is_nan())
72 continue;
73
74 ++count;
75 if (!TEST_MPFR_MATCH_ROUNDING_SILENTLY(mpfr::Operation::Erf, x, result,
76 0.5, rounding_mode)) {
77 ++fails;
78 while (!TEST_MPFR_MATCH_ROUNDING_SILENTLY(mpfr::Operation::Erf, x,
79 result, tol, rounding_mode)) {
80 mx = x;
81 mr = result;
82 tol *= 2.0;
83 }
84 }
85 }
86 tlog << " Log failed: " << fails << "/" << count << "/" << cc
87 << " tests.\n";
88 tlog << " Max ULPs is at most: " << static_cast<uint64_t>(tol) << ".\n";
89 if (fails) {
90 EXPECT_MPFR_MATCH(mpfr::Operation::Erf, mx, mr, 0.5, rounding_mode);
91 }
92 };
93
94 tlog << " Test Rounding To Nearest...\n";
95 test(mpfr::RoundingMode::Nearest);
96
97 tlog << " Test Rounding Downward...\n";
98 test(mpfr::RoundingMode::Downward);
99
100 tlog << " Test Rounding Upward...\n";
101 test(mpfr::RoundingMode::Upward);
102
103 tlog << " Test Rounding Toward Zero...\n";
104 test(mpfr::RoundingMode::TowardZero);
105}
106

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