1 //===-- Unittests for frexpf
2 //-----------------------------------------------===//
3 //
4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5 // See https://llvm.org/LICENSE.txt for license information.
6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "include/math.h"
11 #include "src/math/frexpf.h"
12 #include "utils/FPUtil/BasicOperations.h"
13 #include "utils/FPUtil/BitPatterns.h"
14 #include "utils/FPUtil/ClassificationFunctions.h"
15 #include "utils/FPUtil/FloatOperations.h"
16 #include "utils/FPUtil/FloatProperties.h"
17 #include "utils/MPFRWrapper/MPFRUtils.h"
18 #include "utils/UnitTest/Test.h"
19 
20 using __llvm_libc::fputil::valueAsBits;
21 using __llvm_libc::fputil::valueFromBits;
22 
23 using BitPatterns = __llvm_libc::fputil::BitPatterns<float>;
24 using Properties = __llvm_libc::fputil::FloatProperties<float>;
25 
26 TEST(FrexpfTest, SpecialNumbers) {
27   int exponent;
28 
29   EXPECT_EQ(BitPatterns::aQuietNaN,
30             valueAsBits(__llvm_libc::frexpf(
31                 valueFromBits(BitPatterns::aQuietNaN), &exponent)));
32   EXPECT_EQ(BitPatterns::aNegativeQuietNaN,
33             valueAsBits(__llvm_libc::frexpf(
34                 valueFromBits(BitPatterns::aNegativeQuietNaN), &exponent)));
35 
36   EXPECT_EQ(BitPatterns::aSignallingNaN,
37             valueAsBits(__llvm_libc::frexpf(
38                 valueFromBits(BitPatterns::aSignallingNaN), &exponent)));
39   EXPECT_EQ(
40       BitPatterns::aNegativeSignallingNaN,
41       valueAsBits(__llvm_libc::frexpf(
42           valueFromBits(BitPatterns::aNegativeSignallingNaN), &exponent)));
43 
44   EXPECT_EQ(BitPatterns::inf, valueAsBits(__llvm_libc::frexpf(
45                                   valueFromBits(BitPatterns::inf), &exponent)));
46   EXPECT_EQ(BitPatterns::negInf,
47             valueAsBits(__llvm_libc::frexpf(valueFromBits(BitPatterns::negInf),
48                                             &exponent)));
49 
50   EXPECT_EQ(BitPatterns::zero,
51             valueAsBits(__llvm_libc::frexpf(valueFromBits(BitPatterns::zero),
52                                             &exponent)));
53   EXPECT_EQ(exponent, 0);
54   EXPECT_EQ(BitPatterns::negZero,
55             valueAsBits(__llvm_libc::frexpf(valueFromBits(BitPatterns::negZero),
56                                             &exponent)));
57   EXPECT_EQ(exponent, 0);
58 }
59 
60 TEST(FrexpfTest, PowersOfTwo) {
61   int exponent;
62 
63   EXPECT_EQ(valueAsBits(0.5f),
64             valueAsBits(__llvm_libc::frexpf(1.0f, &exponent)));
65   EXPECT_EQ(exponent, 1);
66   EXPECT_EQ(valueAsBits(-0.5f),
67             valueAsBits(__llvm_libc::frexpf(-1.0f, &exponent)));
68   EXPECT_EQ(exponent, 1);
69 
70   EXPECT_EQ(valueAsBits(0.5f),
71             valueAsBits(__llvm_libc::frexpf(2.0f, &exponent)));
72   EXPECT_EQ(exponent, 2);
73   EXPECT_EQ(valueAsBits(-0.5f),
74             valueAsBits(__llvm_libc::frexpf(-2.0f, &exponent)));
75   EXPECT_EQ(exponent, 2);
76 
77   EXPECT_EQ(valueAsBits(0.5f),
78             valueAsBits(__llvm_libc::frexpf(4.0f, &exponent)));
79   EXPECT_EQ(exponent, 3);
80   EXPECT_EQ(valueAsBits(-0.5f),
81             valueAsBits(__llvm_libc::frexpf(-4.0f, &exponent)));
82   EXPECT_EQ(exponent, 3);
83 
84   EXPECT_EQ(valueAsBits(0.5f),
85             valueAsBits(__llvm_libc::frexpf(8.0f, &exponent)));
86   EXPECT_EQ(exponent, 4);
87   EXPECT_EQ(valueAsBits(-0.5f),
88             valueAsBits(__llvm_libc::frexpf(-8.0f, &exponent)));
89   EXPECT_EQ(exponent, 4);
90 
91   EXPECT_EQ(valueAsBits(0.5f),
92             valueAsBits(__llvm_libc::frexpf(16.0f, &exponent)));
93   EXPECT_EQ(exponent, 5);
94   EXPECT_EQ(valueAsBits(-0.5f),
95             valueAsBits(__llvm_libc::frexpf(-16.0f, &exponent)));
96   EXPECT_EQ(exponent, 5);
97 
98   EXPECT_EQ(valueAsBits(0.5f),
99             valueAsBits(__llvm_libc::frexpf(32.0f, &exponent)));
100   EXPECT_EQ(exponent, 6);
101   EXPECT_EQ(valueAsBits(-0.5f),
102             valueAsBits(__llvm_libc::frexpf(-32.0f, &exponent)));
103   EXPECT_EQ(exponent, 6);
104 
105   EXPECT_EQ(valueAsBits(0.5f),
106             valueAsBits(__llvm_libc::frexpf(64.0f, &exponent)));
107   EXPECT_EQ(exponent, 7);
108   EXPECT_EQ(valueAsBits(-0.5f),
109             valueAsBits(__llvm_libc::frexpf(-64.0f, &exponent)));
110   EXPECT_EQ(exponent, 7);
111 }
112 
113 TEST(FrexpTest, SomeIntegers) {
114   int exponent;
115 
116   EXPECT_EQ(valueAsBits(0.75f),
117             valueAsBits(__llvm_libc::frexpf(24.0f, &exponent)));
118   EXPECT_EQ(exponent, 5);
119   EXPECT_EQ(valueAsBits(-0.75f),
120             valueAsBits(__llvm_libc::frexpf(-24.0f, &exponent)));
121   EXPECT_EQ(exponent, 5);
122 
123   EXPECT_EQ(valueAsBits(0.625f),
124             valueAsBits(__llvm_libc::frexpf(40.0f, &exponent)));
125   EXPECT_EQ(exponent, 6);
126   EXPECT_EQ(valueAsBits(-0.625f),
127             valueAsBits(__llvm_libc::frexpf(-40.0f, &exponent)));
128   EXPECT_EQ(exponent, 6);
129 
130   EXPECT_EQ(valueAsBits(0.78125f),
131             valueAsBits(__llvm_libc::frexpf(800.0f, &exponent)));
132   EXPECT_EQ(exponent, 10);
133   EXPECT_EQ(valueAsBits(-0.78125f),
134             valueAsBits(__llvm_libc::frexpf(-800.0f, &exponent)));
135   EXPECT_EQ(exponent, 10);
136 }
137 
138 TEST(FrexpfTest, InFloatRange) {
139   using BitsType = Properties::BitsType;
140   constexpr BitsType count = 1000000;
141   constexpr BitsType step = UINT32_MAX / count;
142   for (BitsType i = 0, v = 0; i <= count; ++i, v += step) {
143     float x = valueFromBits(v);
144     if (isnan(x) || isinf(x) || x == 0.0)
145       continue;
146     int exponent;
147     float frac = __llvm_libc::frexpf(x, &exponent);
148 
149     ASSERT_TRUE(__llvm_libc::fputil::abs(frac) < 1.0f);
150     ASSERT_TRUE(__llvm_libc::fputil::abs(frac) >= 0.5f);
151   }
152 }
153