xref: /llvm-project/llvm/unittests/Support/EndianTest.cpp (revision 2946cd701067404b99c39fb29dc9c74bd7193eb3)
1 //===- unittests/Support/EndianTest.cpp - Endian.h tests ------------------===//
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 "llvm/Support/Endian.h"
10 #include "llvm/Support/DataTypes.h"
11 #include "gtest/gtest.h"
12 #include <cstdlib>
13 #include <ctime>
14 using namespace llvm;
15 using namespace support;
16 
17 #undef max
18 
19 namespace {
20 
21 TEST(Endian, Read) {
22   // These are 5 bytes so we can be sure at least one of the reads is unaligned.
23   unsigned char bigval[] = {0x00, 0x01, 0x02, 0x03, 0x04};
24   unsigned char littleval[] = {0x00, 0x04, 0x03, 0x02, 0x01};
25   int32_t BigAsHost = 0x00010203;
26   EXPECT_EQ(BigAsHost, (endian::read<int32_t, big, unaligned>(bigval)));
27   int32_t LittleAsHost = 0x02030400;
28   EXPECT_EQ(LittleAsHost,(endian::read<int32_t, little, unaligned>(littleval)));
29 
30   EXPECT_EQ((endian::read<int32_t, big, unaligned>(bigval + 1)),
31             (endian::read<int32_t, little, unaligned>(littleval + 1)));
32 }
33 
34 TEST(Endian, ReadBitAligned) {
35   // Simple test to make sure we properly pull out the 0x0 word.
36   unsigned char littleval[] = {0x3f, 0x00, 0x00, 0x00, 0xc0, 0xff, 0xff, 0xff};
37   unsigned char bigval[] = {0x00, 0x00, 0x00, 0x3f, 0xff, 0xff, 0xff, 0xc0};
38   EXPECT_EQ(
39       (endian::readAtBitAlignment<int, little, unaligned>(&littleval[0], 6)),
40       0x0);
41   EXPECT_EQ((endian::readAtBitAlignment<int, big, unaligned>(&bigval[0], 6)),
42             0x0);
43   // Test to make sure that signed right shift of 0xf0000000 is masked
44   // properly.
45   unsigned char littleval2[] = {0x00, 0x00, 0x00, 0xf0, 0x00, 0x00, 0x00, 0x00};
46   unsigned char bigval2[] = {0xf0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
47   EXPECT_EQ(
48       (endian::readAtBitAlignment<int, little, unaligned>(&littleval2[0], 4)),
49       0x0f000000);
50   EXPECT_EQ((endian::readAtBitAlignment<int, big, unaligned>(&bigval2[0], 4)),
51             0x0f000000);
52   // Test to make sure left shift of start bit doesn't overflow.
53   EXPECT_EQ(
54       (endian::readAtBitAlignment<int, little, unaligned>(&littleval2[0], 1)),
55       0x78000000);
56   EXPECT_EQ((endian::readAtBitAlignment<int, big, unaligned>(&bigval2[0], 1)),
57             0x78000000);
58   // Test to make sure 64-bit int doesn't overflow.
59   unsigned char littleval3[] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf0,
60                                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
61   unsigned char bigval3[] = {0xf0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
62                              0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
63   EXPECT_EQ((endian::readAtBitAlignment<int64_t, little, unaligned>(
64                 &littleval3[0], 4)),
65             0x0f00000000000000);
66   EXPECT_EQ(
67       (endian::readAtBitAlignment<int64_t, big, unaligned>(&bigval3[0], 4)),
68       0x0f00000000000000);
69 }
70 
71 TEST(Endian, WriteBitAligned) {
72   // This test ensures that signed right shift of 0xffffaa is masked
73   // properly.
74   unsigned char bigval[8] = {0x00};
75   endian::writeAtBitAlignment<int32_t, big, unaligned>(bigval, (int)0xffffaaaa,
76                                                        4);
77   EXPECT_EQ(bigval[0], 0xff);
78   EXPECT_EQ(bigval[1], 0xfa);
79   EXPECT_EQ(bigval[2], 0xaa);
80   EXPECT_EQ(bigval[3], 0xa0);
81   EXPECT_EQ(bigval[4], 0x00);
82   EXPECT_EQ(bigval[5], 0x00);
83   EXPECT_EQ(bigval[6], 0x00);
84   EXPECT_EQ(bigval[7], 0x0f);
85 
86   unsigned char littleval[8] = {0x00};
87   endian::writeAtBitAlignment<int32_t, little, unaligned>(littleval,
88                                                           (int)0xffffaaaa, 4);
89   EXPECT_EQ(littleval[0], 0xa0);
90   EXPECT_EQ(littleval[1], 0xaa);
91   EXPECT_EQ(littleval[2], 0xfa);
92   EXPECT_EQ(littleval[3], 0xff);
93   EXPECT_EQ(littleval[4], 0x0f);
94   EXPECT_EQ(littleval[5], 0x00);
95   EXPECT_EQ(littleval[6], 0x00);
96   EXPECT_EQ(littleval[7], 0x00);
97 
98   // This test makes sure 1<<31 doesn't overflow.
99   // Test to make sure left shift of start bit doesn't overflow.
100   unsigned char bigval2[8] = {0x00};
101   endian::writeAtBitAlignment<int32_t, big, unaligned>(bigval2, (int)0xffffffff,
102                                                        1);
103   EXPECT_EQ(bigval2[0], 0xff);
104   EXPECT_EQ(bigval2[1], 0xff);
105   EXPECT_EQ(bigval2[2], 0xff);
106   EXPECT_EQ(bigval2[3], 0xfe);
107   EXPECT_EQ(bigval2[4], 0x00);
108   EXPECT_EQ(bigval2[5], 0x00);
109   EXPECT_EQ(bigval2[6], 0x00);
110   EXPECT_EQ(bigval2[7], 0x01);
111 
112   unsigned char littleval2[8] = {0x00};
113   endian::writeAtBitAlignment<int32_t, little, unaligned>(littleval2,
114                                                           (int)0xffffffff, 1);
115   EXPECT_EQ(littleval2[0], 0xfe);
116   EXPECT_EQ(littleval2[1], 0xff);
117   EXPECT_EQ(littleval2[2], 0xff);
118   EXPECT_EQ(littleval2[3], 0xff);
119   EXPECT_EQ(littleval2[4], 0x01);
120   EXPECT_EQ(littleval2[5], 0x00);
121   EXPECT_EQ(littleval2[6], 0x00);
122   EXPECT_EQ(littleval2[7], 0x00);
123 
124   // Test to make sure 64-bit int doesn't overflow.
125   unsigned char bigval64[16] = {0x00};
126   endian::writeAtBitAlignment<int64_t, big, unaligned>(
127       bigval64, (int64_t)0xffffffffffffffff, 1);
128   EXPECT_EQ(bigval64[0], 0xff);
129   EXPECT_EQ(bigval64[1], 0xff);
130   EXPECT_EQ(bigval64[2], 0xff);
131   EXPECT_EQ(bigval64[3], 0xff);
132   EXPECT_EQ(bigval64[4], 0xff);
133   EXPECT_EQ(bigval64[5], 0xff);
134   EXPECT_EQ(bigval64[6], 0xff);
135   EXPECT_EQ(bigval64[7], 0xfe);
136   EXPECT_EQ(bigval64[8], 0x00);
137   EXPECT_EQ(bigval64[9], 0x00);
138   EXPECT_EQ(bigval64[10], 0x00);
139   EXPECT_EQ(bigval64[11], 0x00);
140   EXPECT_EQ(bigval64[12], 0x00);
141   EXPECT_EQ(bigval64[13], 0x00);
142   EXPECT_EQ(bigval64[14], 0x00);
143   EXPECT_EQ(bigval64[15], 0x01);
144 
145   unsigned char littleval64[16] = {0x00};
146   endian::writeAtBitAlignment<int64_t, little, unaligned>(
147       littleval64, (int64_t)0xffffffffffffffff, 1);
148   EXPECT_EQ(littleval64[0], 0xfe);
149   EXPECT_EQ(littleval64[1], 0xff);
150   EXPECT_EQ(littleval64[2], 0xff);
151   EXPECT_EQ(littleval64[3], 0xff);
152   EXPECT_EQ(littleval64[4], 0xff);
153   EXPECT_EQ(littleval64[5], 0xff);
154   EXPECT_EQ(littleval64[6], 0xff);
155   EXPECT_EQ(littleval64[7], 0xff);
156   EXPECT_EQ(littleval64[8], 0x01);
157   EXPECT_EQ(littleval64[9], 0x00);
158   EXPECT_EQ(littleval64[10], 0x00);
159   EXPECT_EQ(littleval64[11], 0x00);
160   EXPECT_EQ(littleval64[12], 0x00);
161   EXPECT_EQ(littleval64[13], 0x00);
162   EXPECT_EQ(littleval64[14], 0x00);
163   EXPECT_EQ(littleval64[15], 0x00);
164 }
165 
166 TEST(Endian, Write) {
167   unsigned char data[5];
168   endian::write<int32_t, big, unaligned>(data, -1362446643);
169   EXPECT_EQ(data[0], 0xAE);
170   EXPECT_EQ(data[1], 0xCA);
171   EXPECT_EQ(data[2], 0xB6);
172   EXPECT_EQ(data[3], 0xCD);
173   endian::write<int32_t, big, unaligned>(data + 1, -1362446643);
174   EXPECT_EQ(data[1], 0xAE);
175   EXPECT_EQ(data[2], 0xCA);
176   EXPECT_EQ(data[3], 0xB6);
177   EXPECT_EQ(data[4], 0xCD);
178 
179   endian::write<int32_t, little, unaligned>(data, -1362446643);
180   EXPECT_EQ(data[0], 0xCD);
181   EXPECT_EQ(data[1], 0xB6);
182   EXPECT_EQ(data[2], 0xCA);
183   EXPECT_EQ(data[3], 0xAE);
184   endian::write<int32_t, little, unaligned>(data + 1, -1362446643);
185   EXPECT_EQ(data[1], 0xCD);
186   EXPECT_EQ(data[2], 0xB6);
187   EXPECT_EQ(data[3], 0xCA);
188   EXPECT_EQ(data[4], 0xAE);
189 }
190 
191 TEST(Endian, PackedEndianSpecificIntegral) {
192   // These are 5 bytes so we can be sure at least one of the reads is unaligned.
193   unsigned char big[] = {0x00, 0x01, 0x02, 0x03, 0x04};
194   unsigned char little[] = {0x00, 0x04, 0x03, 0x02, 0x01};
195   big32_t    *big_val    =
196     reinterpret_cast<big32_t *>(big + 1);
197   little32_t *little_val =
198     reinterpret_cast<little32_t *>(little + 1);
199 
200   EXPECT_EQ(*big_val, *little_val);
201 }
202 
203 } // end anon namespace
204