llvm/unittests/Support/EndianTest.cpp

   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 TEST(Endian, PacketEndianSpecificIntegralAsEnum) {
 204   enum class Test : uint16_t { ONETWO = 0x0102, TWOONE = 0x0201 };
 205   unsigned char bytes[] = {0x01, 0x02};
 206   using LittleTest = little_t<Test>;
 207   using BigTest = big_t<Test>;
 208   EXPECT_EQ(Test::TWOONE, *reinterpret_cast<LittleTest *>(bytes));
 209   EXPECT_EQ(Test::ONETWO, *reinterpret_cast<BigTest *>(bytes));
 210 }
 211
 212 } // end anon namespace