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      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   // Test to make sure left shift of start bit doesn't overflow.
     54   EXPECT_EQ(
     55       (endian::readAtBitAlignment<int, little, unaligned>(&littleval2[0], 1)),
     56       0x78000000);
     57   EXPECT_EQ((endian::readAtBitAlignment<int, big, unaligned>(&bigval2[0], 1)),
     58             0x78000000);
     59   // Test to make sure 64-bit int doesn't overflow.
     60   unsigned char littleval3[] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf0,
     61                                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
     62   unsigned char bigval3[] = {0xf0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
     63                              0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
     64   EXPECT_EQ((endian::readAtBitAlignment<int64_t, little, unaligned>(
     65                 &littleval3[0], 4)),
     66             0x0f00000000000000);
     67   EXPECT_EQ(
     68       (endian::readAtBitAlignment<int64_t, big, unaligned>(&bigval3[0], 4)),
     69       0x0f00000000000000);
     70 }
     71 
     72 TEST(Endian, WriteBitAligned) {
     73   // This test ensures that signed right shift of 0xffffaa is masked
     74   // properly.
     75   unsigned char bigval[8] = {0x00};
     76   endian::writeAtBitAlignment<int32_t, big, unaligned>(bigval, (int)0xffffaaaa,
     77                                                        4);
     78   EXPECT_EQ(bigval[0], 0xff);
     79   EXPECT_EQ(bigval[1], 0xfa);
     80   EXPECT_EQ(bigval[2], 0xaa);
     81   EXPECT_EQ(bigval[3], 0xa0);
     82   EXPECT_EQ(bigval[4], 0x00);
     83   EXPECT_EQ(bigval[5], 0x00);
     84   EXPECT_EQ(bigval[6], 0x00);
     85   EXPECT_EQ(bigval[7], 0x0f);
     86 
     87   unsigned char littleval[8] = {0x00};
     88   endian::writeAtBitAlignment<int32_t, little, unaligned>(littleval,
     89                                                           (int)0xffffaaaa, 4);
     90   EXPECT_EQ(littleval[0], 0xa0);
     91   EXPECT_EQ(littleval[1], 0xaa);
     92   EXPECT_EQ(littleval[2], 0xfa);
     93   EXPECT_EQ(littleval[3], 0xff);
     94   EXPECT_EQ(littleval[4], 0x0f);
     95   EXPECT_EQ(littleval[5], 0x00);
     96   EXPECT_EQ(littleval[6], 0x00);
     97   EXPECT_EQ(littleval[7], 0x00);
     98 
     99   // This test makes sure 1<<31 doesn't overflow.
    100   // Test to make sure left shift of start bit doesn't overflow.
    101   unsigned char bigval2[8] = {0x00};
    102   endian::writeAtBitAlignment<int32_t, big, unaligned>(bigval2, (int)0xffffffff,
    103                                                        1);
    104   EXPECT_EQ(bigval2[0], 0xff);
    105   EXPECT_EQ(bigval2[1], 0xff);
    106   EXPECT_EQ(bigval2[2], 0xff);
    107   EXPECT_EQ(bigval2[3], 0xfe);
    108   EXPECT_EQ(bigval2[4], 0x00);
    109   EXPECT_EQ(bigval2[5], 0x00);
    110   EXPECT_EQ(bigval2[6], 0x00);
    111   EXPECT_EQ(bigval2[7], 0x01);
    112 
    113   unsigned char littleval2[8] = {0x00};
    114   endian::writeAtBitAlignment<int32_t, little, unaligned>(littleval2,
    115                                                           (int)0xffffffff, 1);
    116   EXPECT_EQ(littleval2[0], 0xfe);
    117   EXPECT_EQ(littleval2[1], 0xff);
    118   EXPECT_EQ(littleval2[2], 0xff);
    119   EXPECT_EQ(littleval2[3], 0xff);
    120   EXPECT_EQ(littleval2[4], 0x01);
    121   EXPECT_EQ(littleval2[5], 0x00);
    122   EXPECT_EQ(littleval2[6], 0x00);
    123   EXPECT_EQ(littleval2[7], 0x00);
    124 
    125   // Test to make sure 64-bit int doesn't overflow.
    126   unsigned char bigval64[16] = {0x00};
    127   endian::writeAtBitAlignment<int64_t, big, unaligned>(
    128       bigval64, (int64_t)0xffffffffffffffff, 1);
    129   EXPECT_EQ(bigval64[0], 0xff);
    130   EXPECT_EQ(bigval64[1], 0xff);
    131   EXPECT_EQ(bigval64[2], 0xff);
    132   EXPECT_EQ(bigval64[3], 0xff);
    133   EXPECT_EQ(bigval64[4], 0xff);
    134   EXPECT_EQ(bigval64[5], 0xff);
    135   EXPECT_EQ(bigval64[6], 0xff);
    136   EXPECT_EQ(bigval64[7], 0xfe);
    137   EXPECT_EQ(bigval64[8], 0x00);
    138   EXPECT_EQ(bigval64[9], 0x00);
    139   EXPECT_EQ(bigval64[10], 0x00);
    140   EXPECT_EQ(bigval64[11], 0x00);
    141   EXPECT_EQ(bigval64[12], 0x00);
    142   EXPECT_EQ(bigval64[13], 0x00);
    143   EXPECT_EQ(bigval64[14], 0x00);
    144   EXPECT_EQ(bigval64[15], 0x01);
    145 
    146   unsigned char littleval64[16] = {0x00};
    147   endian::writeAtBitAlignment<int64_t, little, unaligned>(
    148       littleval64, (int64_t)0xffffffffffffffff, 1);
    149   EXPECT_EQ(littleval64[0], 0xfe);
    150   EXPECT_EQ(littleval64[1], 0xff);
    151   EXPECT_EQ(littleval64[2], 0xff);
    152   EXPECT_EQ(littleval64[3], 0xff);
    153   EXPECT_EQ(littleval64[4], 0xff);
    154   EXPECT_EQ(littleval64[5], 0xff);
    155   EXPECT_EQ(littleval64[6], 0xff);
    156   EXPECT_EQ(littleval64[7], 0xff);
    157   EXPECT_EQ(littleval64[8], 0x01);
    158   EXPECT_EQ(littleval64[9], 0x00);
    159   EXPECT_EQ(littleval64[10], 0x00);
    160   EXPECT_EQ(littleval64[11], 0x00);
    161   EXPECT_EQ(littleval64[12], 0x00);
    162   EXPECT_EQ(littleval64[13], 0x00);
    163   EXPECT_EQ(littleval64[14], 0x00);
    164   EXPECT_EQ(littleval64[15], 0x00);
    165 }
    166 
    167 TEST(Endian, Write) {
    168   unsigned char data[5];
    169   endian::write<int32_t, big, unaligned>(data, -1362446643);
    170   EXPECT_EQ(data[0], 0xAE);
    171   EXPECT_EQ(data[1], 0xCA);
    172   EXPECT_EQ(data[2], 0xB6);
    173   EXPECT_EQ(data[3], 0xCD);
    174   endian::write<int32_t, big, unaligned>(data + 1, -1362446643);
    175   EXPECT_EQ(data[1], 0xAE);
    176   EXPECT_EQ(data[2], 0xCA);
    177   EXPECT_EQ(data[3], 0xB6);
    178   EXPECT_EQ(data[4], 0xCD);
    179 
    180   endian::write<int32_t, little, unaligned>(data, -1362446643);
    181   EXPECT_EQ(data[0], 0xCD);
    182   EXPECT_EQ(data[1], 0xB6);
    183   EXPECT_EQ(data[2], 0xCA);
    184   EXPECT_EQ(data[3], 0xAE);
    185   endian::write<int32_t, little, unaligned>(data + 1, -1362446643);
    186   EXPECT_EQ(data[1], 0xCD);
    187   EXPECT_EQ(data[2], 0xB6);
    188   EXPECT_EQ(data[3], 0xCA);
    189   EXPECT_EQ(data[4], 0xAE);
    190 }
    191 
    192 TEST(Endian, PackedEndianSpecificIntegral) {
    193   // These are 5 bytes so we can be sure at least one of the reads is unaligned.
    194   unsigned char big[] = {0x00, 0x01, 0x02, 0x03, 0x04};
    195   unsigned char little[] = {0x00, 0x04, 0x03, 0x02, 0x01};
    196   big32_t    *big_val    =
    197     reinterpret_cast<big32_t *>(big + 1);
    198   little32_t *little_val =
    199     reinterpret_cast<little32_t *>(little + 1);
    200 
    201   EXPECT_EQ(*big_val, *little_val);
    202 }
    203 
    204 } // end anon namespace
    205