1 //===-- Unittests for logb ------------------------------------------------===//
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 "src/math/logb.h"
10 #include "utils/FPUtil/BitPatterns.h"
11 #include "utils/FPUtil/FloatOperations.h"
12 #include "utils/FPUtil/FloatProperties.h"
13 #include "utils/FPUtil/ManipulationFunctions.h"
14 #include "utils/UnitTest/Test.h"
15 #include <math.h>
16
17 using __llvm_libc::fputil::valueAsBits;
18 using __llvm_libc::fputil::valueFromBits;
19
20 using BitPatterns = __llvm_libc::fputil::BitPatterns<double>;
21 using Properties = __llvm_libc::fputil::FloatProperties<double>;
22
TEST(LogbTest,SpecialNumbers)23 TEST(LogbTest, SpecialNumbers) {
24 EXPECT_EQ(
25 BitPatterns::aQuietNaN,
26 valueAsBits(__llvm_libc::logb(valueFromBits(BitPatterns::aQuietNaN))));
27 EXPECT_EQ(BitPatterns::aNegativeQuietNaN,
28 valueAsBits(__llvm_libc::logb(
29 valueFromBits(BitPatterns::aNegativeQuietNaN))));
30
31 EXPECT_EQ(BitPatterns::aSignallingNaN,
32 valueAsBits(
33 __llvm_libc::logb(valueFromBits(BitPatterns::aSignallingNaN))));
34 EXPECT_EQ(BitPatterns::aNegativeSignallingNaN,
35 valueAsBits(__llvm_libc::logb(
36 valueFromBits(BitPatterns::aNegativeSignallingNaN))));
37
38 EXPECT_EQ(BitPatterns::inf,
39 valueAsBits(__llvm_libc::logb(valueFromBits(BitPatterns::inf))));
40 EXPECT_EQ(BitPatterns::inf,
41 valueAsBits(__llvm_libc::logb(valueFromBits(BitPatterns::negInf))));
42
43 EXPECT_EQ(BitPatterns::negInf,
44 valueAsBits(__llvm_libc::logb(valueFromBits(BitPatterns::zero))));
45 EXPECT_EQ(BitPatterns::negInf, valueAsBits(__llvm_libc::logb(
46 valueFromBits(BitPatterns::negZero))));
47 }
48
TEST(LogbTest,PowersOfTwo)49 TEST(LogbTest, PowersOfTwo) {
50 EXPECT_EQ(valueAsBits(0.0), valueAsBits(__llvm_libc::logb(1.0)));
51 EXPECT_EQ(valueAsBits(0.0), valueAsBits(__llvm_libc::logb(-1.0)));
52
53 EXPECT_EQ(valueAsBits(1.0), valueAsBits(__llvm_libc::logb(2.0)));
54 EXPECT_EQ(valueAsBits(1.0), valueAsBits(__llvm_libc::logb(-2.0)));
55
56 EXPECT_EQ(valueAsBits(2.0), valueAsBits(__llvm_libc::logb(4.0)));
57 EXPECT_EQ(valueAsBits(2.0), valueAsBits(__llvm_libc::logb(-4.0)));
58
59 EXPECT_EQ(valueAsBits(3.0), valueAsBits(__llvm_libc::logb(8.0)));
60 EXPECT_EQ(valueAsBits(3.0), valueAsBits(__llvm_libc::logb(-8.0)));
61
62 EXPECT_EQ(valueAsBits(4.0), valueAsBits(__llvm_libc::logb(16.0)));
63 EXPECT_EQ(valueAsBits(4.0), valueAsBits(__llvm_libc::logb(-16.0)));
64
65 EXPECT_EQ(valueAsBits(5.0), valueAsBits(__llvm_libc::logb(32.0)));
66 EXPECT_EQ(valueAsBits(5.0), valueAsBits(__llvm_libc::logb(-32.0)));
67 }
68
TEST(LogbTest,SomeIntegers)69 TEST(LogbTest, SomeIntegers) {
70 EXPECT_EQ(valueAsBits(1.0), valueAsBits(__llvm_libc::logb(3.0)));
71 EXPECT_EQ(valueAsBits(1.0), valueAsBits(__llvm_libc::logb(-3.0)));
72
73 EXPECT_EQ(valueAsBits(2.0), valueAsBits(__llvm_libc::logb(7.0)));
74 EXPECT_EQ(valueAsBits(2.0), valueAsBits(__llvm_libc::logb(-7.0)));
75
76 EXPECT_EQ(valueAsBits(3.0), valueAsBits(__llvm_libc::logb(10.0)));
77 EXPECT_EQ(valueAsBits(3.0), valueAsBits(__llvm_libc::logb(-10.0)));
78
79 EXPECT_EQ(valueAsBits(4.0), valueAsBits(__llvm_libc::logb(31.0)));
80 EXPECT_EQ(valueAsBits(4.0), valueAsBits(__llvm_libc::logb(-31.0)));
81
82 EXPECT_EQ(valueAsBits(5.0), valueAsBits(__llvm_libc::logb(55.0)));
83 EXPECT_EQ(valueAsBits(5.0), valueAsBits(__llvm_libc::logb(-55.0)));
84 }
85
TEST(LogbTest,InDoubleRange)86 TEST(LogbTest, InDoubleRange) {
87 using BitsType = Properties::BitsType;
88 constexpr BitsType count = 10000000;
89 constexpr BitsType step = UINT64_MAX / count;
90 for (BitsType i = 0, v = 0; i <= count; ++i, v += step) {
91 double x = valueFromBits(v);
92 if (isnan(x) || isinf(x) || x == 0.0)
93 continue;
94
95 int exponent;
96 __llvm_libc::fputil::frexp(x, exponent);
97 ASSERT_TRUE(double(exponent) == __llvm_libc::logb(x) + 1.0);
98 }
99 }
100