1 //===-- Unittests for modf ------------------------------------------------===//
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/modf.h"
11 #include "utils/FPUtil/BasicOperations.h"
12 #include "utils/FPUtil/BitPatterns.h"
13 #include "utils/FPUtil/FloatOperations.h"
14 #include "utils/FPUtil/FloatProperties.h"
15 #include "utils/FPUtil/NearestIntegerOperations.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<double>;
22 using Properties = __llvm_libc::fputil::FloatProperties<double>;
23 
24 TEST(ModfTest, SpecialNumbers) {
25   double integral;
26 
27   EXPECT_EQ(BitPatterns::aQuietNaN,
28             valueAsBits(__llvm_libc::modf(valueFromBits(BitPatterns::aQuietNaN),
29                                           &integral)));
30   EXPECT_EQ(BitPatterns::aNegativeQuietNaN,
31             valueAsBits(__llvm_libc::modf(
32                 valueFromBits(BitPatterns::aNegativeQuietNaN), &integral)));
33 
34   EXPECT_EQ(BitPatterns::aSignallingNaN,
35             valueAsBits(__llvm_libc::modf(
36                 valueFromBits(BitPatterns::aSignallingNaN), &integral)));
37   EXPECT_EQ(
38       BitPatterns::aNegativeSignallingNaN,
39       valueAsBits(__llvm_libc::modf(
40           valueFromBits(BitPatterns::aNegativeSignallingNaN), &integral)));
41 
42   EXPECT_EQ(BitPatterns::zero,
43             valueAsBits(
44                 __llvm_libc::modf(valueFromBits(BitPatterns::inf), &integral)));
45   EXPECT_EQ(valueAsBits(integral), BitPatterns::inf);
46 
47   EXPECT_EQ(BitPatterns::negZero,
48             valueAsBits(__llvm_libc::modf(valueFromBits(BitPatterns::negInf),
49                                           &integral)));
50   EXPECT_EQ(valueAsBits(integral), BitPatterns::negInf);
51 
52   EXPECT_EQ(BitPatterns::zero,
53             valueAsBits(__llvm_libc::modf(valueFromBits(BitPatterns::zero),
54                                           &integral)));
55   EXPECT_EQ(valueAsBits(integral), BitPatterns::zero);
56 
57   EXPECT_EQ(BitPatterns::negZero,
58             valueAsBits(__llvm_libc::modf(valueFromBits(BitPatterns::negZero),
59                                           &integral)));
60   EXPECT_EQ(valueAsBits(integral), BitPatterns::negZero);
61 }
62 
63 TEST(ModfTest, Integers) {
64   double integral;
65 
66   EXPECT_EQ(BitPatterns::zero, valueAsBits(__llvm_libc::modf(1.0, &integral)));
67   EXPECT_EQ(valueAsBits(integral), valueAsBits(1.0));
68 
69   EXPECT_EQ(BitPatterns::negZero,
70             valueAsBits(__llvm_libc::modf(-1.0, &integral)));
71   EXPECT_EQ(valueAsBits(integral), valueAsBits(-1.0));
72 
73   EXPECT_EQ(BitPatterns::zero, valueAsBits(__llvm_libc::modf(10.0, &integral)));
74   EXPECT_EQ(valueAsBits(integral), valueAsBits(10.0));
75 
76   EXPECT_EQ(BitPatterns::negZero,
77             valueAsBits(__llvm_libc::modf(-10.0, &integral)));
78   EXPECT_EQ(valueAsBits(integral), valueAsBits(-10.0));
79 
80   EXPECT_EQ(BitPatterns::zero,
81             valueAsBits(__llvm_libc::modf(12345.0, &integral)));
82   EXPECT_EQ(valueAsBits(integral), valueAsBits(12345.0));
83 
84   EXPECT_EQ(BitPatterns::negZero,
85             valueAsBits(__llvm_libc::modf(-12345.0, &integral)));
86   EXPECT_EQ(valueAsBits(integral), valueAsBits(-12345.0));
87 }
88 
89 TEST(ModfTest, Fractions) {
90   double integral;
91 
92   EXPECT_EQ(valueAsBits(0.5), valueAsBits(__llvm_libc::modf(1.5, &integral)));
93   EXPECT_EQ(valueAsBits(integral), valueAsBits(1.0));
94 
95   EXPECT_EQ(valueAsBits(-0.5), valueAsBits(__llvm_libc::modf(-1.5, &integral)));
96   EXPECT_EQ(valueAsBits(integral), valueAsBits(-1.0));
97 
98   EXPECT_EQ(valueAsBits(0.75),
99             valueAsBits(__llvm_libc::modf(10.75, &integral)));
100   EXPECT_EQ(valueAsBits(integral), valueAsBits(10.0));
101 
102   EXPECT_EQ(valueAsBits(-0.75),
103             valueAsBits(__llvm_libc::modf(-10.75, &integral)));
104   EXPECT_EQ(valueAsBits(integral), valueAsBits(-10.0));
105 
106   EXPECT_EQ(valueAsBits(0.125),
107             valueAsBits(__llvm_libc::modf(100.125, &integral)));
108   EXPECT_EQ(valueAsBits(integral), valueAsBits(100.0));
109 
110   EXPECT_EQ(valueAsBits(-0.125),
111             valueAsBits(__llvm_libc::modf(-100.125, &integral)));
112   EXPECT_EQ(valueAsBits(integral), valueAsBits(-100.0));
113 }
114 
115 TEST(ModfTest, InDoubleRange) {
116   using BitsType = Properties::BitsType;
117   constexpr BitsType count = 10000000;
118   constexpr BitsType step = UINT64_MAX / count;
119   for (BitsType i = 0, v = 0; i <= count; ++i, v += step) {
120     double x = valueFromBits(v);
121     if (isnan(x) || isinf(x) || x == 0.0) {
122       // These conditions have been tested in other tests.
123       continue;
124     }
125 
126     double integral;
127     double frac = __llvm_libc::modf(x, &integral);
128     ASSERT_TRUE(__llvm_libc::fputil::abs(frac) < 1.0);
129     ASSERT_TRUE(__llvm_libc::fputil::trunc(x) == integral);
130     ASSERT_TRUE(integral + frac == x);
131   }
132 }
133