blob: 2a80191daaca8a720a8398b65a836f08333a1a7b [file] [log] [blame]
//===- 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 <stdlib.h>
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)
GTEST_SKIP();
// Test expectation generated with:
// $ truncate --size=`echo 2^32-1+42 | bc` /tmp/foo
// $ crc32 /tmp/foo
EXPECT_EQ(0xE46F28FBU, llvm::crc32(ArrayRef(TestData, TestSize)));
free(TestData);
}
#endif
} // end anonymous namespace