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 <errno.h>
17#include <stdint.h>
18
19using LlvmLibcErffTest = LIBC_NAMESPACE::testing::FPTest<float>;
20
21namespace mpfr = LIBC_NAMESPACE::testing::mpfr;
22using LIBC_NAMESPACE::testing::tlog;
23
24TEST_F(LlvmLibcErffTest, SpecialNumbers) {
25 EXPECT_FP_EQ_ALL_ROUNDING(aNaN, LIBC_NAMESPACE::erff(aNaN));
26 EXPECT_FP_EQ_ALL_ROUNDING(1.0f, LIBC_NAMESPACE::erff(inf));
27 EXPECT_FP_EQ_ALL_ROUNDING(-1.0f, LIBC_NAMESPACE::erff(neg_inf));
28 EXPECT_FP_EQ_ALL_ROUNDING(zero, LIBC_NAMESPACE::erff(zero));
29 EXPECT_FP_EQ_ALL_ROUNDING(neg_zero, LIBC_NAMESPACE::erff(neg_zero));
30}
31
32TEST_F(LlvmLibcErffTest, TrickyInputs) {
33 constexpr int N = 2;
34 constexpr uint32_t INPUTS[N] = {
35 0x3f65'9229U, // |x| = 0x1.cb2452p-1f
36 0x4004'1e6aU, // |x| = 0x1.083cd4p+1f
37 };
38 for (int i = 0; i < N; ++i) {
39 float x = FPBits(INPUTS[i]).get_val();
40 EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Erf, x,
41 LIBC_NAMESPACE::erff(x), 0.5);
42 EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Erf, -x,
43 LIBC_NAMESPACE::erff(-x), 0.5);
44 }
45}
46
47TEST_F(LlvmLibcErffTest, InFloatRange) {
48 constexpr uint32_t COUNT = 234561;
49 constexpr uint32_t START = 0; // 0
50 constexpr uint32_t STOP = 0x4080'0000U; // 4.0f
51
52 constexpr uint64_t STEP = (STOP - START) / COUNT;
53
54 auto test = [&](mpfr::RoundingMode rounding_mode) {
55 mpfr::ForceRoundingMode __r(rounding_mode);
56 if (!__r.success)
57 return;
58
59 uint32_t fails = 0;
60 uint32_t count = 0;
61 uint32_t cc = 0;
62 float mx, mr = 0.0;
63 double tol = 0.5;
64
65 for (uint32_t i = 0, v = START; i <= COUNT; ++i, v += STEP) {
66 float x = FPBits(v).get_val();
67 if (isnan(x: x))
68 continue;
69
70 float result = LIBC_NAMESPACE::erff(x);
71 ++cc;
72 if (isnan(x: result))
73 continue;
74
75 ++count;
76 if (!TEST_MPFR_MATCH_ROUNDING_SILENTLY(mpfr::Operation::Erf, x, result,
77 0.5, rounding_mode)) {
78 ++fails;
79 while (!TEST_MPFR_MATCH_ROUNDING_SILENTLY(mpfr::Operation::Erf, x,
80 result, tol, rounding_mode)) {
81 mx = x;
82 mr = result;
83 tol *= 2.0;
84 }
85 }
86 }
87 tlog << " Log failed: " << fails << "/" << count << "/" << cc
88 << " tests.\n";
89 tlog << " Max ULPs is at most: " << static_cast<uint64_t>(tol) << ".\n";
90 if (fails) {
91 EXPECT_MPFR_MATCH(mpfr::Operation::Erf, mx, mr, 0.5, rounding_mode);
92 }
93 };
94
95 tlog << " Test Rounding To Nearest...\n";
96 test(mpfr::RoundingMode::Nearest);
97
98 tlog << " Test Rounding Downward...\n";
99 test(mpfr::RoundingMode::Downward);
100
101 tlog << " Test Rounding Upward...\n";
102 test(mpfr::RoundingMode::Upward);
103
104 tlog << " Test Rounding Toward Zero...\n";
105 test(mpfr::RoundingMode::TowardZero);
106}
107

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