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 "src/__support/CPP/limits.h" // INT_MAX
13#include "src/__support/FPUtil/FPBits.h"
14#include "src/__support/FPUtil/ManipulationFunctions.h"
15#include "test/UnitTest/FEnvSafeTest.h"
16#include "test/UnitTest/Test.h"
17
18template <typename OutType, typename InType>
19class LlvmLibcILogbTest : public LIBC_NAMESPACE::testing::FEnvSafeTest {
20 using FPBits = LIBC_NAMESPACE::fputil::FPBits<InType>;
21 using StorageType = typename FPBits::StorageType;
22
23public:
24 typedef OutType (*Func)(InType);
25
26 void test_special_numbers(Func func) {
27 EXPECT_EQ(LIBC_NAMESPACE::fputil::IntLogbConstants<OutType>::FP_LOGB0,
28 func(FPBits::zero(Sign::POS).get_val()));
29 EXPECT_EQ(LIBC_NAMESPACE::fputil::IntLogbConstants<OutType>::FP_LOGB0,
30 func(FPBits::zero(Sign::NEG).get_val()));
31 EXPECT_EQ(LIBC_NAMESPACE::fputil::IntLogbConstants<OutType>::FP_LOGBNAN,
32 func(FPBits::quiet_nan().get_val()));
33 EXPECT_EQ(LIBC_NAMESPACE::fputil::IntLogbConstants<OutType>::T_MAX,
34 func(FPBits::inf(Sign::POS).get_val()));
35 EXPECT_EQ(LIBC_NAMESPACE::fputil::IntLogbConstants<OutType>::T_MAX,
36 func(FPBits::inf(Sign::NEG).get_val()));
37 }
38
39 void test_powers_of_two(Func func) {
40 EXPECT_EQ(OutType(0), func(InType(1.0)));
41 EXPECT_EQ(OutType(0), func(InType(-1.0)));
42
43 EXPECT_EQ(OutType(1), func(InType(2.0)));
44 EXPECT_EQ(OutType(1), func(InType(-2.0)));
45
46 EXPECT_EQ(OutType(2), func(InType(4.0)));
47 EXPECT_EQ(OutType(2), func(InType(-4.0)));
48
49 EXPECT_EQ(OutType(3), func(InType(8.0)));
50 EXPECT_EQ(OutType(3), func(-8.0));
51
52 EXPECT_EQ(OutType(4), func(16.0));
53 EXPECT_EQ(OutType(4), func(-16.0));
54
55 EXPECT_EQ(OutType(5), func(32.0));
56 EXPECT_EQ(OutType(5), func(-32.0));
57 }
58
59 void test_some_integers(Func func) {
60 EXPECT_EQ(OutType(1), func(InType(3.0)));
61 EXPECT_EQ(OutType(1), func(InType(-3.0)));
62
63 EXPECT_EQ(OutType(2), func(InType(7.0)));
64 EXPECT_EQ(OutType(2), func(InType(-7.0)));
65
66 EXPECT_EQ(OutType(3), func(InType(10.0)));
67 EXPECT_EQ(OutType(3), func(InType(-10.0)));
68
69 EXPECT_EQ(OutType(4), func(InType(31.0)));
70 EXPECT_EQ(OutType(4), func(-31.0));
71
72 EXPECT_EQ(OutType(5), func(55.0));
73 EXPECT_EQ(OutType(5), func(-55.0));
74 }
75
76 void test_subnormal_range(Func func) {
77 constexpr StorageType MIN_SUBNORMAL = FPBits::min_subnormal().uintval();
78 constexpr StorageType MAX_SUBNORMAL = FPBits::max_subnormal().uintval();
79 constexpr StorageType COUNT = 10'001;
80 constexpr StorageType STEP = (MAX_SUBNORMAL - MIN_SUBNORMAL) / COUNT;
81 for (StorageType v = MIN_SUBNORMAL; v <= MAX_SUBNORMAL; v += STEP) {
82 FPBits x_bits = FPBits(v);
83 if (x_bits.is_zero() || x_bits.is_inf_or_nan())
84 continue;
85
86 InType x = x_bits.get_val();
87
88 int exponent;
89 LIBC_NAMESPACE::fputil::frexp(x, exponent);
90 ASSERT_EQ(static_cast<OutType>(exponent), func(x) + OutType(1));
91 }
92 }
93
94 void test_normal_range(Func func) {
95 constexpr StorageType MIN_NORMAL = FPBits::min_normal().uintval();
96 constexpr StorageType MAX_NORMAL = FPBits::max_normal().uintval();
97 constexpr StorageType COUNT = 10'001;
98 constexpr StorageType STEP = (MAX_NORMAL - MIN_NORMAL) / COUNT;
99 for (StorageType v = MIN_NORMAL; v <= MAX_NORMAL; v += STEP) {
100 FPBits x_bits = FPBits(v);
101 if (x_bits.is_zero() || x_bits.is_inf_or_nan())
102 continue;
103
104 InType x = x_bits.get_val();
105
106 int exponent;
107 LIBC_NAMESPACE::fputil::frexp(x, exponent);
108 ASSERT_EQ(static_cast<OutType>(exponent), func(x) + OutType(1));
109 }
110 }
111};
112
113#define LIST_INTLOGB_TESTS(OutType, InType, Func) \
114 using LlvmLibcIntLogbTest = LlvmLibcILogbTest<OutType, InType>; \
115 TEST_F(LlvmLibcIntLogbTest, SpecialNumbers) { test_special_numbers(&Func); } \
116 TEST_F(LlvmLibcIntLogbTest, PowersOfTwo) { test_powers_of_two(&Func); } \
117 TEST_F(LlvmLibcIntLogbTest, SomeIntegers) { test_some_integers(&Func); } \
118 TEST_F(LlvmLibcIntLogbTest, SubnormalRange) { test_subnormal_range(&Func); } \
119 TEST_F(LlvmLibcIntLogbTest, NormalRange) { test_normal_range(&Func); } \
120 static_assert(true)
121
122#endif // LLVM_LIBC_TEST_SRC_MATH_ILOGBTEST_H
123

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