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