1 //===- llvm/unittest/Support/CRCTest.cpp - CRC 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 // This file implements unit tests for CRC calculation functions. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "llvm/Support/CRC.h" 14 #include "llvm/ADT/StringExtras.h" 15 #include "gtest/gtest.h" 16 #include <stdlib.h> 17 18 using namespace llvm; 19 20 namespace { 21 22 TEST(CRCTest, CRC32) { 23 EXPECT_EQ(0x414FA339U, llvm::crc32(arrayRefFromStringRef( 24 "The quick brown fox jumps over the lazy dog"))); 25 26 // CRC-32/ISO-HDLC test vector 27 // http://reveng.sourceforge.net/crc-catalogue/17plus.htm#crc.cat.crc-32c 28 EXPECT_EQ(0xCBF43926U, llvm::crc32(arrayRefFromStringRef("123456789"))); 29 30 // Check the CRC-32 of each byte value, exercising all of CRCTable. 31 for (int i = 0; i < 256; i++) { 32 // Compute CRCTable[i] using Hacker's Delight (2nd ed.) Figure 14-7. 33 uint32_t crc = i; 34 for (int j = 7; j >= 0; j--) { 35 uint32_t mask = -(crc & 1); 36 crc = (crc >> 1) ^ (0xEDB88320 & mask); 37 } 38 39 // CRCTable[i] is the CRC-32 of i without the initial and final bit flips. 40 uint8_t byte = i; 41 EXPECT_EQ(crc, ~llvm::crc32(0xFFFFFFFFU, byte)); 42 } 43 44 EXPECT_EQ(0x00000000U, llvm::crc32(arrayRefFromStringRef(""))); 45 } 46 47 #if (SIZE_MAX > UINT32_MAX) && defined(EXPENSIVE_CHECKS) 48 TEST(CRCTest, LargeCRC32) { 49 // Check that crc32 can handle inputs with sizes larger than 32 bits. 50 size_t TestSize = (size_t)UINT32_MAX + 42; 51 uint8_t *TestData = (uint8_t*)calloc(TestSize, 1); 52 if (!TestData) 53 return; 54 55 // Test expectation generated with: 56 // $ truncate --size=`echo 2^32-1+42 | bc` /tmp/foo 57 // $ crc32 /tmp/foo 58 EXPECT_EQ(0xE46F28FBU, llvm::crc32(makeArrayRef(TestData, TestSize))); 59 60 free(TestData); 61 } 62 #endif 63 64 } // end anonymous namespace 65