1//===-- Utility class to test different flavors of ilogb --------*- C++ -*-===//
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#ifndef LLVM_LIBC_TEST_SRC_MATH_ILOGBTEST_H
10#define LLVM_LIBC_TEST_SRC_MATH_ILOGBTEST_H
11
12#include "hdr/math_macros.h"
13#include "src/__support/CPP/limits.h" // INT_MAX
14#include "src/__support/FPUtil/FPBits.h"
15#include "src/__support/FPUtil/ManipulationFunctions.h"
16#include "test/UnitTest/FEnvSafeTest.h"
17#include "test/UnitTest/Test.h"
18
19using LIBC_NAMESPACE::Sign;
20
21class LlvmLibcILogbTest : public LIBC_NAMESPACE::testing::FEnvSafeTest {
22public:
23 template <typename T> struct ILogbFunc {
24 typedef int (*Func)(T);
25 };
26
27 template <typename T>
28 void test_special_numbers(typename ILogbFunc<T>::Func func) {
29 using FPBits = LIBC_NAMESPACE::fputil::FPBits<T>;
30
31 EXPECT_EQ(FP_ILOGB0, func(FPBits::zero(Sign::POS).get_val()));
32 EXPECT_EQ(FP_ILOGB0, func(FPBits::zero(Sign::NEG).get_val()));
33 EXPECT_EQ(FP_ILOGBNAN, func(FPBits::quiet_nan().get_val()));
34 EXPECT_EQ(INT_MAX, func(FPBits::inf(Sign::POS).get_val()));
35 EXPECT_EQ(INT_MAX, func(FPBits::inf(Sign::NEG).get_val()));
36 }
37
38 template <typename T>
39 void test_powers_of_two(typename ILogbFunc<T>::Func func) {
40 EXPECT_EQ(0, func(T(1.0)));
41 EXPECT_EQ(0, func(T(-1.0)));
42
43 EXPECT_EQ(1, func(T(2.0)));
44 EXPECT_EQ(1, func(T(-2.0)));
45
46 EXPECT_EQ(2, func(T(4.0)));
47 EXPECT_EQ(2, func(T(-4.0)));
48
49 EXPECT_EQ(3, func(T(8.0)));
50 EXPECT_EQ(3, func(-8.0));
51
52 EXPECT_EQ(4, func(16.0));
53 EXPECT_EQ(4, func(-16.0));
54
55 EXPECT_EQ(5, func(32.0));
56 EXPECT_EQ(5, func(-32.0));
57 }
58
59 template <typename T>
60 void test_some_integers(typename ILogbFunc<T>::Func func) {
61 EXPECT_EQ(1, func(T(3.0)));
62 EXPECT_EQ(1, func(T(-3.0)));
63
64 EXPECT_EQ(2, func(T(7.0)));
65 EXPECT_EQ(2, func(T(-7.0)));
66
67 EXPECT_EQ(3, func(T(10.0)));
68 EXPECT_EQ(3, func(T(-10.0)));
69
70 EXPECT_EQ(4, func(T(31.0)));
71 EXPECT_EQ(4, func(-31.0));
72
73 EXPECT_EQ(5, func(55.0));
74 EXPECT_EQ(5, func(-55.0));
75 }
76
77 template <typename T>
78 void test_subnormal_range(typename ILogbFunc<T>::Func func) {
79 using FPBits = LIBC_NAMESPACE::fputil::FPBits<T>;
80 using StorageType = typename FPBits::StorageType;
81 constexpr StorageType MIN_SUBNORMAL = FPBits::min_subnormal().uintval();
82 constexpr StorageType MAX_SUBNORMAL = FPBits::max_subnormal().uintval();
83 constexpr StorageType COUNT = 10'001;
84 constexpr StorageType STEP = (MAX_SUBNORMAL - MIN_SUBNORMAL) / COUNT;
85 for (StorageType v = MIN_SUBNORMAL; v <= MAX_SUBNORMAL; v += STEP) {
86 T x = FPBits(v).get_val();
87 if (FPBits(v).is_nan() || FPBits(v).is_inf() || x == 0.0)
88 continue;
89
90 int exponent;
91 LIBC_NAMESPACE::fputil::frexp(x, exponent);
92 ASSERT_EQ(exponent, func(x) + 1);
93 }
94 }
95
96 template <typename T>
97 void test_normal_range(typename ILogbFunc<T>::Func func) {
98 using FPBits = LIBC_NAMESPACE::fputil::FPBits<T>;
99 using StorageType = typename FPBits::StorageType;
100 constexpr StorageType MIN_NORMAL = FPBits::min_normal().uintval();
101 constexpr StorageType MAX_NORMAL = FPBits::max_normal().uintval();
102 constexpr StorageType COUNT = 10'001;
103 constexpr StorageType STEP = (MAX_NORMAL - MIN_NORMAL) / COUNT;
104 for (StorageType v = MIN_NORMAL; v <= MAX_NORMAL; v += STEP) {
105 T x = FPBits(v).get_val();
106 if (FPBits(v).is_nan() || FPBits(v).is_inf() || x == 0.0)
107 continue;
108
109 int exponent;
110 LIBC_NAMESPACE::fputil::frexp(x, exponent);
111 ASSERT_EQ(exponent, func(x) + 1);
112 }
113 }
114};
115
116#endif // LLVM_LIBC_TEST_SRC_MATH_ILOGBTEST_H
117

source code of libc/test/src/math/ILogbTest.h