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 "src/math/frexpl.h"
10 #include "utils/FPUtil/BasicOperations.h"
11 #include "utils/FPUtil/FPBits.h"
12 #include "utils/MPFRWrapper/MPFRUtils.h"
13 #include "utils/UnitTest/Test.h"
14 #include <math.h>
15 
16 typedef long double LD;
17 using FPBits = __llvm_libc::fputil::FPBits<long double>;
18 
19 namespace mpfr = __llvm_libc::testing::mpfr;
20 
21 TEST(LlvmLibcFrexplTest, SpecialNumbers) {
22   int exponent;
23 
24   EXPECT_TRUE(LD(FPBits::inf()) ==
25               __llvm_libc::frexpl(LD(FPBits::inf()), &exponent));
26   EXPECT_TRUE(LD(FPBits::negInf()) ==
27               __llvm_libc::frexpl(LD(FPBits::negInf()), &exponent));
28 
29   EXPECT_TRUE(LD(FPBits::zero()) ==
30               __llvm_libc::frexpl(LD(FPBits::zero()), &exponent));
31   EXPECT_EQ(exponent, 0);
32 
33   EXPECT_TRUE(LD(FPBits::negZero()) ==
34               __llvm_libc::frexpl(LD(FPBits::negZero()), &exponent));
35   EXPECT_EQ(exponent, 0);
36 
37   EXPECT_TRUE(
38       FPBits(__llvm_libc::frexpl(LD(FPBits::buildNaN(1)), &exponent)).isNaN());
39 }
40 
41 TEST(LlvmLibcFrexplTest, PowersOfTwo) {
42   int exponent;
43 
44   EXPECT_TRUE(0.5l == __llvm_libc::frexpl(1.0l, &exponent));
45   EXPECT_EQ(exponent, 1);
46   EXPECT_TRUE(-0.5l == __llvm_libc::frexpl(-1.0l, &exponent));
47   EXPECT_EQ(exponent, 1);
48 
49   EXPECT_TRUE(0.5l == __llvm_libc::frexpl(2.0l, &exponent));
50   EXPECT_EQ(exponent, 2);
51   EXPECT_TRUE(-0.5l == __llvm_libc::frexpl(-2.0l, &exponent));
52   EXPECT_EQ(exponent, 2);
53 
54   EXPECT_TRUE(0.5l == __llvm_libc::frexpl(4.0l, &exponent));
55   EXPECT_EQ(exponent, 3);
56   EXPECT_TRUE(-0.5l == __llvm_libc::frexpl(-4.0l, &exponent));
57   EXPECT_EQ(exponent, 3);
58 
59   EXPECT_TRUE(0.5l == __llvm_libc::frexpl(8.0l, &exponent));
60   EXPECT_EQ(exponent, 4);
61   EXPECT_TRUE(-0.5l == __llvm_libc::frexpl(-8.0l, &exponent));
62   EXPECT_EQ(exponent, 4);
63 
64   EXPECT_TRUE(0.5l == __llvm_libc::frexpl(16.0l, &exponent));
65   EXPECT_EQ(exponent, 5);
66   EXPECT_TRUE(-0.5l == __llvm_libc::frexpl(-16.0l, &exponent));
67   EXPECT_EQ(exponent, 5);
68 
69   EXPECT_TRUE(0.5l == __llvm_libc::frexpl(32.0l, &exponent));
70   EXPECT_EQ(exponent, 6);
71   EXPECT_TRUE(-0.5l == __llvm_libc::frexpl(-32.0l, &exponent));
72   EXPECT_EQ(exponent, 6);
73 }
74 
75 TEST(LlvmLibcFrexplTest, SomeIntegers) {
76   int exponent;
77 
78   EXPECT_TRUE(0.75l == __llvm_libc::frexpl(24.0l, &exponent));
79   EXPECT_EQ(exponent, 5);
80   EXPECT_TRUE(-0.75l == __llvm_libc::frexpl(-24.0l, &exponent));
81   EXPECT_EQ(exponent, 5);
82 
83   EXPECT_TRUE(0.625l == __llvm_libc::frexpl(40.0l, &exponent));
84   EXPECT_EQ(exponent, 6);
85   EXPECT_TRUE(-0.625l == __llvm_libc::frexpl(-40.0l, &exponent));
86   EXPECT_EQ(exponent, 6);
87 
88   EXPECT_TRUE(0.78125l == __llvm_libc::frexpl(800.0l, &exponent));
89   EXPECT_EQ(exponent, 10);
90   EXPECT_TRUE(-0.78125l == __llvm_libc::frexpl(-800.0l, &exponent));
91   EXPECT_EQ(exponent, 10);
92 }
93 
94 TEST(LlvmLibcFrexplTest, LongDoubleRange) {
95   using UIntType = FPBits::UIntType;
96   constexpr UIntType count = 10000000;
97   constexpr UIntType step = UIntType(-1) / count;
98   for (UIntType i = 0, v = 0; i <= count; ++i, v += step) {
99     long double x = static_cast<long double>(FPBits(v));
100     if (isnan(x) || isinf(x) || x == 0.0l)
101       continue;
102 
103     mpfr::BinaryOutput<long double> result;
104     result.f = __llvm_libc::frexpl(x, &result.i);
105 
106     ASSERT_TRUE(__llvm_libc::fputil::abs(result.f) < 1.0);
107     ASSERT_TRUE(__llvm_libc::fputil::abs(result.f) >= 0.5);
108     ASSERT_MPFR_MATCH(mpfr::Operation::Frexp, x, result, 0.0);
109   }
110 }
111