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