1 //===-- Unittests for frexpl ----------------------------------------------===//
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 "include/math.h"
10 #include "src/math/frexpl.h"
11 #include "utils/FPUtil/BasicOperations.h"
12 #include "utils/FPUtil/FPBits.h"
13 #include "utils/UnitTest/Test.h"
14 
15 #include <iostream>
16 
17 using FPBits = __llvm_libc::fputil::FPBits<long double>;
18 
19 TEST(FrexplTest, SpecialNumbers) {
20   int exponent;
21 
22   EXPECT_TRUE(FPBits::inf() == __llvm_libc::frexpl(FPBits::inf(), &exponent));
23   EXPECT_TRUE(FPBits::negInf() ==
24               __llvm_libc::frexpl(FPBits::negInf(), &exponent));
25 
26   EXPECT_TRUE(FPBits::zero() == __llvm_libc::frexpl(FPBits::zero(), &exponent));
27   EXPECT_EQ(exponent, 0);
28 
29   EXPECT_TRUE(FPBits::negZero() ==
30               __llvm_libc::frexpl(FPBits::negZero(), &exponent));
31   EXPECT_EQ(exponent, 0);
32 
33   EXPECT_TRUE(
34       FPBits(__llvm_libc::frexpl(FPBits::buildNaN(1), &exponent)).isNaN());
35 }
36 
37 TEST(FrexplTest, PowersOfTwo) {
38   int exponent;
39 
40   EXPECT_TRUE(0.5l == __llvm_libc::frexpl(1.0l, &exponent));
41   EXPECT_EQ(exponent, 1);
42   EXPECT_TRUE(-0.5l == __llvm_libc::frexpl(-1.0l, &exponent));
43   EXPECT_EQ(exponent, 1);
44 
45   EXPECT_TRUE(0.5l == __llvm_libc::frexpl(2.0l, &exponent));
46   EXPECT_EQ(exponent, 2);
47   EXPECT_TRUE(-0.5l == __llvm_libc::frexpl(-2.0l, &exponent));
48   EXPECT_EQ(exponent, 2);
49 
50   EXPECT_TRUE(0.5l == __llvm_libc::frexpl(4.0l, &exponent));
51   EXPECT_EQ(exponent, 3);
52   EXPECT_TRUE(-0.5l == __llvm_libc::frexpl(-4.0l, &exponent));
53   EXPECT_EQ(exponent, 3);
54 
55   EXPECT_TRUE(0.5l == __llvm_libc::frexpl(8.0l, &exponent));
56   EXPECT_EQ(exponent, 4);
57   EXPECT_TRUE(-0.5l == __llvm_libc::frexpl(-8.0l, &exponent));
58   EXPECT_EQ(exponent, 4);
59 
60   EXPECT_TRUE(0.5l == __llvm_libc::frexpl(16.0l, &exponent));
61   EXPECT_EQ(exponent, 5);
62   EXPECT_TRUE(-0.5l == __llvm_libc::frexpl(-16.0l, &exponent));
63   EXPECT_EQ(exponent, 5);
64 
65   EXPECT_TRUE(0.5l == __llvm_libc::frexpl(32.0l, &exponent));
66   EXPECT_EQ(exponent, 6);
67   EXPECT_TRUE(-0.5l == __llvm_libc::frexpl(-32.0l, &exponent));
68   EXPECT_EQ(exponent, 6);
69 }
70 
71 TEST(FrexplTest, SomeIntegers) {
72   int exponent;
73 
74   EXPECT_TRUE(0.75l == __llvm_libc::frexpl(24.0l, &exponent));
75   EXPECT_EQ(exponent, 5);
76   EXPECT_TRUE(-0.75l == __llvm_libc::frexpl(-24.0l, &exponent));
77   EXPECT_EQ(exponent, 5);
78 
79   EXPECT_TRUE(0.625l == __llvm_libc::frexpl(40.0l, &exponent));
80   EXPECT_EQ(exponent, 6);
81   EXPECT_TRUE(-0.625l == __llvm_libc::frexpl(-40.0l, &exponent));
82   EXPECT_EQ(exponent, 6);
83 
84   EXPECT_TRUE(0.78125l == __llvm_libc::frexpl(800.0l, &exponent));
85   EXPECT_EQ(exponent, 10);
86   EXPECT_TRUE(-0.78125l == __llvm_libc::frexpl(-800.0l, &exponent));
87   EXPECT_EQ(exponent, 10);
88 }
89 
90 TEST(FrexplTest, LongDoubleRange) {
91   using UIntType = FPBits::UIntType;
92   constexpr UIntType count = 10000000;
93   constexpr UIntType step = UIntType(-1) / count;
94   for (UIntType i = 0, v = 0; i <= count; ++i, v += step) {
95     long double x = FPBits(v);
96     if (isnan(x) || isinf(x) || x == 0.0l)
97       continue;
98 
99     int exponent;
100     long double frac = __llvm_libc::frexpl(x, &exponent);
101 
102     ASSERT_TRUE(__llvm_libc::fputil::abs(frac) < 1.0l);
103     ASSERT_TRUE(__llvm_libc::fputil::abs(frac) >= 0.5l);
104   }
105 }
106