unittests/Support/EndianTest.cpp

   1 //===- unittests/Support/EndianTest.cpp - Endian.h tests ------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "llvm/Support/Endian.h"
  11 #include "llvm/Support/DataTypes.h"
  12 #include "gtest/gtest.h"
  13 #include <cstdlib>
  14 #include <ctime>
  15 using namespace llvm;
  16 using namespace support;
  17
  18 #undef max
  19
  20 namespace {
  21
  22 TEST(Endian, Read) {
  23   // These are 5 bytes so we can be sure at least one of the reads is unaligned.
  24   unsigned char bigval[] = {0x00, 0x01, 0x02, 0x03, 0x04};
  25   unsigned char littleval[] = {0x00, 0x04, 0x03, 0x02, 0x01};
  26   int32_t BigAsHost = 0x00010203;
  27   EXPECT_EQ(BigAsHost, (endian::read<int32_t, big, unaligned>(bigval)));
  28   int32_t LittleAsHost = 0x02030400;
  29   EXPECT_EQ(LittleAsHost,(endian::read<int32_t, little, unaligned>(littleval)));
  30
  31   EXPECT_EQ((endian::read<int32_t, big, unaligned>(bigval + 1)),
  32             (endian::read<int32_t, little, unaligned>(littleval + 1)));
  33 }
  34
  35 TEST(Endian, ReadBitAligned) {
  36   // Simple test to make sure we properly pull out the 0x0 word.
  37   unsigned char littleval[] = {0x3f, 0x00, 0x00, 0x00, 0xc0, 0xff, 0xff, 0xff};
  38   unsigned char bigval[] = {0x00, 0x00, 0x00, 0x3f, 0xff, 0xff, 0xff, 0xc0};
  39   EXPECT_EQ(
  40       (endian::readAtBitAlignment<int, little, unaligned>(&littleval[0], 6)),
  41       0x0);
  42   EXPECT_EQ((endian::readAtBitAlignment<int, big, unaligned>(&bigval[0], 6)),
  43             0x0);
  44   // Test to make sure that signed right shift of 0xf0000000 is masked
  45   // properly.
  46   unsigned char littleval2[] = {0x00, 0x00, 0x00, 0xf0, 0x00, 0x00, 0x00, 0x00};
  47   unsigned char bigval2[] = {0xf0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
  48   EXPECT_EQ(
  49       (endian::readAtBitAlignment<int, little, unaligned>(&littleval2[0], 4)),
  50       0x0f000000);
  51   EXPECT_EQ((endian::readAtBitAlignment<int, big, unaligned>(&bigval2[0], 4)),
  52             0x0f000000);
  53 }
  54
  55 TEST(Endian, WriteBitAligned) {
  56   // This test ensures that signed right shift of 0xffffaa is masked
  57   // properly.
  58   unsigned char bigval[8] = {0x00};
  59   endian::writeAtBitAlignment<int32_t, big, unaligned>(bigval, (int)0xffffaaaa,
  60                                                        4);
  61   EXPECT_EQ(bigval[0], 0xff);
  62   EXPECT_EQ(bigval[1], 0xfa);
  63   EXPECT_EQ(bigval[2], 0xaa);
  64   EXPECT_EQ(bigval[3], 0xa0);
  65   EXPECT_EQ(bigval[4], 0x00);
  66   EXPECT_EQ(bigval[5], 0x00);
  67   EXPECT_EQ(bigval[6], 0x00);
  68   EXPECT_EQ(bigval[7], 0x0f);
  69
  70   unsigned char littleval[8] = {0x00};
  71   endian::writeAtBitAlignment<int32_t, little, unaligned>(littleval,
  72                                                           (int)0xffffaaaa, 4);
  73   EXPECT_EQ(littleval[0], 0xa0);
  74   EXPECT_EQ(littleval[1], 0xaa);
  75   EXPECT_EQ(littleval[2], 0xfa);
  76   EXPECT_EQ(littleval[3], 0xff);
  77   EXPECT_EQ(littleval[4], 0x0f);
  78   EXPECT_EQ(littleval[5], 0x00);
  79   EXPECT_EQ(littleval[6], 0x00);
  80   EXPECT_EQ(littleval[7], 0x00);
  81 }
  82
  83 TEST(Endian, Write) {
  84   unsigned char data[5];
  85   endian::write<int32_t, big, unaligned>(data, -1362446643);
  86   EXPECT_EQ(data[0], 0xAE);
  87   EXPECT_EQ(data[1], 0xCA);
  88   EXPECT_EQ(data[2], 0xB6);
  89   EXPECT_EQ(data[3], 0xCD);
  90   endian::write<int32_t, big, unaligned>(data + 1, -1362446643);
  91   EXPECT_EQ(data[1], 0xAE);
  92   EXPECT_EQ(data[2], 0xCA);
  93   EXPECT_EQ(data[3], 0xB6);
  94   EXPECT_EQ(data[4], 0xCD);
  95
  96   endian::write<int32_t, little, unaligned>(data, -1362446643);
  97   EXPECT_EQ(data[0], 0xCD);
  98   EXPECT_EQ(data[1], 0xB6);
  99   EXPECT_EQ(data[2], 0xCA);
 100   EXPECT_EQ(data[3], 0xAE);
 101   endian::write<int32_t, little, unaligned>(data + 1, -1362446643);
 102   EXPECT_EQ(data[1], 0xCD);
 103   EXPECT_EQ(data[2], 0xB6);
 104   EXPECT_EQ(data[3], 0xCA);
 105   EXPECT_EQ(data[4], 0xAE);
 106 }
 107
 108 TEST(Endian, PackedEndianSpecificIntegral) {
 109   // These are 5 bytes so we can be sure at least one of the reads is unaligned.
 110   unsigned char big[] = {0x00, 0x01, 0x02, 0x03, 0x04};
 111   unsigned char little[] = {0x00, 0x04, 0x03, 0x02, 0x01};
 112   big32_t    *big_val    =
 113     reinterpret_cast<big32_t *>(big + 1);
 114   little32_t *little_val =
 115     reinterpret_cast<little32_t *>(little + 1);
 116
 117   EXPECT_EQ(*big_val, *little_val);
 118 }
 119
 120 } // end anon namespace