xref: /aosp_15_r20/external/llvm-libc/test/src/math/smoke/ILogbTest.h (revision 71db0c75aadcf003ffe3238005f61d7618a3fead)
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/algorithm.h"
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 
18 using LIBC_NAMESPACE::Sign;
19 
20 template <typename OutType, typename InType>
21 class LlvmLibcILogbTest : public LIBC_NAMESPACE::testing::FEnvSafeTest {
22   using FPBits = LIBC_NAMESPACE::fputil::FPBits<InType>;
23   using StorageType = typename FPBits::StorageType;
24 
25 public:
26   typedef OutType (*Func)(InType);
27 
test_special_numbers(Func func)28   void test_special_numbers(Func func) {
29     EXPECT_EQ(LIBC_NAMESPACE::fputil::IntLogbConstants<OutType>::FP_LOGB0,
30               func(FPBits::zero(Sign::POS).get_val()));
31     EXPECT_EQ(LIBC_NAMESPACE::fputil::IntLogbConstants<OutType>::FP_LOGB0,
32               func(FPBits::zero(Sign::NEG).get_val()));
33     EXPECT_EQ(LIBC_NAMESPACE::fputil::IntLogbConstants<OutType>::FP_LOGBNAN,
34               func(FPBits::quiet_nan().get_val()));
35     EXPECT_EQ(LIBC_NAMESPACE::fputil::IntLogbConstants<OutType>::T_MAX,
36               func(FPBits::inf(Sign::POS).get_val()));
37     EXPECT_EQ(LIBC_NAMESPACE::fputil::IntLogbConstants<OutType>::T_MAX,
38               func(FPBits::inf(Sign::NEG).get_val()));
39   }
40 
test_powers_of_two(Func func)41   void test_powers_of_two(Func func) {
42     EXPECT_EQ(OutType(0), func(InType(1.0)));
43     EXPECT_EQ(OutType(0), func(InType(-1.0)));
44 
45     EXPECT_EQ(OutType(1), func(InType(2.0)));
46     EXPECT_EQ(OutType(1), func(InType(-2.0)));
47 
48     EXPECT_EQ(OutType(2), func(InType(4.0)));
49     EXPECT_EQ(OutType(2), func(InType(-4.0)));
50 
51     EXPECT_EQ(OutType(3), func(InType(8.0)));
52     EXPECT_EQ(OutType(3), func(InType(-8.0)));
53 
54     EXPECT_EQ(OutType(4), func(InType(16.0)));
55     EXPECT_EQ(OutType(4), func(InType(-16.0)));
56 
57     EXPECT_EQ(OutType(5), func(InType(32.0)));
58     EXPECT_EQ(OutType(5), func(InType(-32.0)));
59   }
60 
test_some_integers(Func func)61   void test_some_integers(Func func) {
62     EXPECT_EQ(OutType(1), func(InType(3.0)));
63     EXPECT_EQ(OutType(1), func(InType(-3.0)));
64 
65     EXPECT_EQ(OutType(2), func(InType(7.0)));
66     EXPECT_EQ(OutType(2), func(InType(-7.0)));
67 
68     EXPECT_EQ(OutType(3), func(InType(10.0)));
69     EXPECT_EQ(OutType(3), func(InType(-10.0)));
70 
71     EXPECT_EQ(OutType(4), func(InType(31.0)));
72     EXPECT_EQ(OutType(4), func(InType(-31.0)));
73 
74     EXPECT_EQ(OutType(5), func(InType(55.0)));
75     EXPECT_EQ(OutType(5), func(InType(-55.0)));
76   }
77 
test_subnormal_range(Func func)78   void test_subnormal_range(Func func) {
79     constexpr StorageType MIN_SUBNORMAL = FPBits::min_subnormal().uintval();
80     constexpr StorageType MAX_SUBNORMAL = FPBits::max_subnormal().uintval();
81     constexpr int COUNT = 10'001;
82     constexpr StorageType STEP = LIBC_NAMESPACE::cpp::max(
83         static_cast<StorageType>((MAX_SUBNORMAL - MIN_SUBNORMAL) / COUNT),
84         StorageType(1));
85     for (StorageType v = MIN_SUBNORMAL; v <= MAX_SUBNORMAL; v += STEP) {
86       FPBits x_bits(v);
87       if (x_bits.is_zero() || x_bits.is_inf_or_nan())
88         continue;
89 
90       InType x = x_bits.get_val();
91 
92       int exponent;
93       LIBC_NAMESPACE::fputil::frexp(x, exponent);
94       ASSERT_EQ(static_cast<OutType>(exponent), func(x) + OutType(1));
95     }
96   }
97 
98   void test_normal_range(Func func) {
99     constexpr StorageType MIN_NORMAL = FPBits::min_normal().uintval();
100     constexpr StorageType MAX_NORMAL = FPBits::max_normal().uintval();
101     constexpr int COUNT = 10'001;
102     constexpr StorageType STEP = LIBC_NAMESPACE::cpp::max(
103         static_cast<StorageType>((MAX_NORMAL - MIN_NORMAL) / COUNT),
104         StorageType(1));
105     for (StorageType v = MIN_NORMAL; v <= MAX_NORMAL; v += STEP) {
106       FPBits x_bits(v);
107       if (x_bits.is_zero() || x_bits.is_inf_or_nan())
108         continue;
109 
110       InType x = x_bits.get_val();
111 
112       int exponent;
113       LIBC_NAMESPACE::fputil::frexp(x, exponent);
114       ASSERT_EQ(static_cast<OutType>(exponent), func(x) + OutType(1));
115     }
116   }
117 };
118 
119 #define LIST_INTLOGB_TESTS(OutType, InType, Func)                              \
120   using LlvmLibcIntLogbTest = LlvmLibcILogbTest<OutType, InType>;              \
121   TEST_F(LlvmLibcIntLogbTest, SpecialNumbers) { test_special_numbers(&Func); } \
122   TEST_F(LlvmLibcIntLogbTest, PowersOfTwo) { test_powers_of_two(&Func); }      \
123   TEST_F(LlvmLibcIntLogbTest, SomeIntegers) { test_some_integers(&Func); }     \
124   TEST_F(LlvmLibcIntLogbTest, SubnormalRange) { test_subnormal_range(&Func); } \
125   TEST_F(LlvmLibcIntLogbTest, NormalRange) { test_normal_range(&Func); }       \
126   static_assert(true)
127 
128 #endif // LLVM_LIBC_TEST_SRC_MATH_ILOGBTEST_H
129