65 lines · cpp
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-exception6//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 18using namespace llvm;19 20namespace {21 22TEST(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 vector27 // http://reveng.sourceforge.net/crc-catalogue/17plus.htm#crc.cat.crc-32c28 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)48TEST(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 GTEST_SKIP();54 55 // Test expectation generated with:56 // $ truncate --size=`echo 2^32-1+42 | bc` /tmp/foo57 // $ crc32 /tmp/foo58 EXPECT_EQ(0xE46F28FBU, llvm::crc32(ArrayRef(TestData, TestSize)));59 60 free(TestData);61}62#endif63 64} // end anonymous namespace65