//===- llvm/unittest/Support/CRCTest.cpp - CRC tests ----------------------===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// // // This file implements unit tests for CRC calculation functions. // //===----------------------------------------------------------------------===// #include "llvm/Support/CRC.h" #include "llvm/ADT/StringExtras.h" #include "gtest/gtest.h" #include using namespace llvm; namespace { TEST(CRCTest, CRC32) { EXPECT_EQ(0x414FA339U, llvm::crc32(arrayRefFromStringRef( "The quick brown fox jumps over the lazy dog"))); // CRC-32/ISO-HDLC test vector // http://reveng.sourceforge.net/crc-catalogue/17plus.htm#crc.cat.crc-32c EXPECT_EQ(0xCBF43926U, llvm::crc32(arrayRefFromStringRef("123456789"))); // Check the CRC-32 of each byte value, exercising all of CRCTable. for (int i = 0; i < 256; i++) { // Compute CRCTable[i] using Hacker's Delight (2nd ed.) Figure 14-7. uint32_t crc = i; for (int j = 7; j >= 0; j--) { uint32_t mask = -(crc & 1); crc = (crc >> 1) ^ (0xEDB88320 & mask); } // CRCTable[i] is the CRC-32 of i without the initial and final bit flips. uint8_t byte = i; EXPECT_EQ(crc, ~llvm::crc32(0xFFFFFFFFU, byte)); } EXPECT_EQ(0x00000000U, llvm::crc32(arrayRefFromStringRef(""))); } #if (SIZE_MAX > UINT32_MAX) && defined(EXPENSIVE_CHECKS) TEST(CRCTest, LargeCRC32) { // Check that crc32 can handle inputs with sizes larger than 32 bits. size_t TestSize = (size_t)UINT32_MAX + 42; uint8_t *TestData = (uint8_t*)calloc(TestSize, 1); if (!TestData) return; // Test expectation generated with: // $ truncate --size=`echo 2^32-1+42 | bc` /tmp/foo // $ crc32 /tmp/foo EXPECT_EQ(0xE46F28FBU, llvm::crc32(makeArrayRef(TestData, TestSize))); free(TestData); } #endif } // end anonymous namespace