xref: /llvm-project/llvm/unittests/Support/EndianTest.cpp (revision 02f67c097de12dc9f6c97a68d9e180af79a2483b)
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,
27             (endian::read<int32_t, llvm::endianness::big, unaligned>(bigval)));
28   int32_t LittleAsHost = 0x02030400;
29   EXPECT_EQ(
30       LittleAsHost,
31       (endian::read<int32_t, llvm::endianness::little, unaligned>(littleval)));
32 
33   EXPECT_EQ(
34       (endian::read<int32_t, llvm::endianness::big, unaligned>(bigval + 1)),
35       (endian::read<int32_t, llvm::endianness::little, unaligned>(littleval +
36                                                                   1)));
37 }
38 
39 TEST(Endian, ReadBitAligned) {
40   // Simple test to make sure we properly pull out the 0x0 word.
41   unsigned char littleval[] = {0x3f, 0x00, 0x00, 0x00, 0xc0, 0xff, 0xff, 0xff};
42   unsigned char bigval[] = {0x00, 0x00, 0x00, 0x3f, 0xff, 0xff, 0xff, 0xc0};
43   EXPECT_EQ(
44       (endian::readAtBitAlignment<int, llvm::endianness::little, unaligned>(
45           &littleval[0], 6)),
46       0x0);
47   EXPECT_EQ((endian::readAtBitAlignment<int, llvm::endianness::big, unaligned>(
48                 &bigval[0], 6)),
49             0x0);
50   // Test to make sure that signed right shift of 0xf0000000 is masked
51   // properly.
52   unsigned char littleval2[] = {0x00, 0x00, 0x00, 0xf0, 0x00, 0x00, 0x00, 0x00};
53   unsigned char bigval2[] = {0xf0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
54   EXPECT_EQ(
55       (endian::readAtBitAlignment<int, llvm::endianness::little, unaligned>(
56           &littleval2[0], 4)),
57       0x0f000000);
58   EXPECT_EQ((endian::readAtBitAlignment<int, llvm::endianness::big, unaligned>(
59                 &bigval2[0], 4)),
60             0x0f000000);
61   // Test to make sure left shift of start bit doesn't overflow.
62   EXPECT_EQ(
63       (endian::readAtBitAlignment<int, llvm::endianness::little, unaligned>(
64           &littleval2[0], 1)),
65       0x78000000);
66   EXPECT_EQ((endian::readAtBitAlignment<int, llvm::endianness::big, unaligned>(
67                 &bigval2[0], 1)),
68             0x78000000);
69   // Test to make sure 64-bit int doesn't overflow.
70   unsigned char littleval3[] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf0,
71                                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
72   unsigned char bigval3[] = {0xf0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
73                              0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
74   EXPECT_EQ(
75       (endian::readAtBitAlignment<int64_t, llvm::endianness::little, unaligned>(
76           &littleval3[0], 4)),
77       0x0f00000000000000);
78   EXPECT_EQ(
79       (endian::readAtBitAlignment<int64_t, llvm::endianness::big, unaligned>(
80           &bigval3[0], 4)),
81       0x0f00000000000000);
82 }
83 
84 TEST(Endian, WriteBitAligned) {
85   // This test ensures that signed right shift of 0xffffaa is masked
86   // properly.
87   unsigned char bigval[8] = {0x00};
88   endian::writeAtBitAlignment<int32_t, llvm::endianness::big, unaligned>(
89       bigval, (int)0xffffaaaa, 4);
90   EXPECT_EQ(bigval[0], 0xff);
91   EXPECT_EQ(bigval[1], 0xfa);
92   EXPECT_EQ(bigval[2], 0xaa);
93   EXPECT_EQ(bigval[3], 0xa0);
94   EXPECT_EQ(bigval[4], 0x00);
95   EXPECT_EQ(bigval[5], 0x00);
96   EXPECT_EQ(bigval[6], 0x00);
97   EXPECT_EQ(bigval[7], 0x0f);
98 
99   unsigned char littleval[8] = {0x00};
100   endian::writeAtBitAlignment<int32_t, llvm::endianness::little, unaligned>(
101       littleval, (int)0xffffaaaa, 4);
102   EXPECT_EQ(littleval[0], 0xa0);
103   EXPECT_EQ(littleval[1], 0xaa);
104   EXPECT_EQ(littleval[2], 0xfa);
105   EXPECT_EQ(littleval[3], 0xff);
106   EXPECT_EQ(littleval[4], 0x0f);
107   EXPECT_EQ(littleval[5], 0x00);
108   EXPECT_EQ(littleval[6], 0x00);
109   EXPECT_EQ(littleval[7], 0x00);
110 
111   // This test makes sure 1<<31 doesn't overflow.
112   // Test to make sure left shift of start bit doesn't overflow.
113   unsigned char bigval2[8] = {0x00};
114   endian::writeAtBitAlignment<int32_t, llvm::endianness::big, unaligned>(
115       bigval2, (int)0xffffffff, 1);
116   EXPECT_EQ(bigval2[0], 0xff);
117   EXPECT_EQ(bigval2[1], 0xff);
118   EXPECT_EQ(bigval2[2], 0xff);
119   EXPECT_EQ(bigval2[3], 0xfe);
120   EXPECT_EQ(bigval2[4], 0x00);
121   EXPECT_EQ(bigval2[5], 0x00);
122   EXPECT_EQ(bigval2[6], 0x00);
123   EXPECT_EQ(bigval2[7], 0x01);
124 
125   unsigned char littleval2[8] = {0x00};
126   endian::writeAtBitAlignment<int32_t, llvm::endianness::little, unaligned>(
127       littleval2, (int)0xffffffff, 1);
128   EXPECT_EQ(littleval2[0], 0xfe);
129   EXPECT_EQ(littleval2[1], 0xff);
130   EXPECT_EQ(littleval2[2], 0xff);
131   EXPECT_EQ(littleval2[3], 0xff);
132   EXPECT_EQ(littleval2[4], 0x01);
133   EXPECT_EQ(littleval2[5], 0x00);
134   EXPECT_EQ(littleval2[6], 0x00);
135   EXPECT_EQ(littleval2[7], 0x00);
136 
137   // Test to make sure 64-bit int doesn't overflow.
138   unsigned char bigval64[16] = {0x00};
139   endian::writeAtBitAlignment<int64_t, llvm::endianness::big, unaligned>(
140       bigval64, (int64_t)0xffffffffffffffff, 1);
141   EXPECT_EQ(bigval64[0], 0xff);
142   EXPECT_EQ(bigval64[1], 0xff);
143   EXPECT_EQ(bigval64[2], 0xff);
144   EXPECT_EQ(bigval64[3], 0xff);
145   EXPECT_EQ(bigval64[4], 0xff);
146   EXPECT_EQ(bigval64[5], 0xff);
147   EXPECT_EQ(bigval64[6], 0xff);
148   EXPECT_EQ(bigval64[7], 0xfe);
149   EXPECT_EQ(bigval64[8], 0x00);
150   EXPECT_EQ(bigval64[9], 0x00);
151   EXPECT_EQ(bigval64[10], 0x00);
152   EXPECT_EQ(bigval64[11], 0x00);
153   EXPECT_EQ(bigval64[12], 0x00);
154   EXPECT_EQ(bigval64[13], 0x00);
155   EXPECT_EQ(bigval64[14], 0x00);
156   EXPECT_EQ(bigval64[15], 0x01);
157 
158   unsigned char littleval64[16] = {0x00};
159   endian::writeAtBitAlignment<int64_t, llvm::endianness::little, unaligned>(
160       littleval64, (int64_t)0xffffffffffffffff, 1);
161   EXPECT_EQ(littleval64[0], 0xfe);
162   EXPECT_EQ(littleval64[1], 0xff);
163   EXPECT_EQ(littleval64[2], 0xff);
164   EXPECT_EQ(littleval64[3], 0xff);
165   EXPECT_EQ(littleval64[4], 0xff);
166   EXPECT_EQ(littleval64[5], 0xff);
167   EXPECT_EQ(littleval64[6], 0xff);
168   EXPECT_EQ(littleval64[7], 0xff);
169   EXPECT_EQ(littleval64[8], 0x01);
170   EXPECT_EQ(littleval64[9], 0x00);
171   EXPECT_EQ(littleval64[10], 0x00);
172   EXPECT_EQ(littleval64[11], 0x00);
173   EXPECT_EQ(littleval64[12], 0x00);
174   EXPECT_EQ(littleval64[13], 0x00);
175   EXPECT_EQ(littleval64[14], 0x00);
176   EXPECT_EQ(littleval64[15], 0x00);
177 }
178 
179 TEST(Endian, Write) {
180   unsigned char data[5];
181   endian::write<int32_t, llvm::endianness::big, unaligned>(data, -1362446643);
182   EXPECT_EQ(data[0], 0xAE);
183   EXPECT_EQ(data[1], 0xCA);
184   EXPECT_EQ(data[2], 0xB6);
185   EXPECT_EQ(data[3], 0xCD);
186   endian::write<int32_t, llvm::endianness::big, unaligned>(data + 1,
187                                                            -1362446643);
188   EXPECT_EQ(data[1], 0xAE);
189   EXPECT_EQ(data[2], 0xCA);
190   EXPECT_EQ(data[3], 0xB6);
191   EXPECT_EQ(data[4], 0xCD);
192 
193   endian::write<int32_t, llvm::endianness::little, unaligned>(data,
194                                                               -1362446643);
195   EXPECT_EQ(data[0], 0xCD);
196   EXPECT_EQ(data[1], 0xB6);
197   EXPECT_EQ(data[2], 0xCA);
198   EXPECT_EQ(data[3], 0xAE);
199   endian::write<int32_t, llvm::endianness::little, unaligned>(data + 1,
200                                                               -1362446643);
201   EXPECT_EQ(data[1], 0xCD);
202   EXPECT_EQ(data[2], 0xB6);
203   EXPECT_EQ(data[3], 0xCA);
204   EXPECT_EQ(data[4], 0xAE);
205 }
206 
207 TEST(Endian, PackedEndianSpecificIntegral) {
208   // These are 5 bytes so we can be sure at least one of the reads is unaligned.
209   unsigned char big[] = {0x00, 0x01, 0x02, 0x03, 0x04};
210   unsigned char little[] = {0x00, 0x04, 0x03, 0x02, 0x01};
211   big32_t    *big_val    =
212     reinterpret_cast<big32_t *>(big + 1);
213   little32_t *little_val =
214     reinterpret_cast<little32_t *>(little + 1);
215 
216   EXPECT_EQ(*big_val, *little_val);
217 }
218 
219 TEST(Endian, PacketEndianSpecificIntegralAsEnum) {
220   enum class Test : uint16_t { ONETWO = 0x0102, TWOONE = 0x0201 };
221   unsigned char bytes[] = {0x01, 0x02};
222   using LittleTest = little_t<Test>;
223   using BigTest = big_t<Test>;
224   EXPECT_EQ(Test::TWOONE, *reinterpret_cast<LittleTest *>(bytes));
225   EXPECT_EQ(Test::ONETWO, *reinterpret_cast<BigTest *>(bytes));
226 }
227 
228 } // end anon namespace
229