| 1 | //===- llvm/unittest/Support/CRCTest.cpp - CRC tests ----------------------===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | // |
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| 9 | // This file implements unit tests for CRC calculation functions. |
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| 10 | // |
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| 11 | //===----------------------------------------------------------------------===// |
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| 12 | |
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| 13 | #include "llvm/Support/CRC.h" |
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| 14 | #include "llvm/ADT/StringExtras.h" |
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| 15 | #include "gtest/gtest.h" |
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| 16 | #include <stdlib.h> |
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| 17 | |
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| 18 | using namespace llvm; |
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| 19 | |
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| 20 | namespace { |
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| 21 | |
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| 22 | TEST(CRCTest, CRC32) { |
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| 23 | EXPECT_EQ(0x414FA339U, llvm::crc32(arrayRefFromStringRef( |
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| 24 | "The quick brown fox jumps over the lazy dog" ))); |
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| 25 | |
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| 26 | // CRC-32/ISO-HDLC test vector |
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| 27 | // http://reveng.sourceforge.net/crc-catalogue/17plus.htm#crc.cat.crc-32c |
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| 28 | EXPECT_EQ(0xCBF43926U, llvm::crc32(arrayRefFromStringRef("123456789" ))); |
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| 29 | |
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| 30 | // Check the CRC-32 of each byte value, exercising all of CRCTable. |
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| 31 | for (int i = 0; i < 256; i++) { |
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| 32 | // Compute CRCTable[i] using Hacker's Delight (2nd ed.) Figure 14-7. |
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| 33 | uint32_t crc = i; |
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| 34 | for (int j = 7; j >= 0; j--) { |
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| 35 | uint32_t mask = -(crc & 1); |
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| 36 | crc = (crc >> 1) ^ (0xEDB88320 & mask); |
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| 37 | } |
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| 38 | |
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| 39 | // CRCTable[i] is the CRC-32 of i without the initial and final bit flips. |
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| 40 | uint8_t byte = i; |
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| 41 | EXPECT_EQ(crc, ~llvm::crc32(0xFFFFFFFFU, byte)); |
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| 42 | } |
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| 43 | |
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| 44 | EXPECT_EQ(0x00000000U, llvm::crc32(arrayRefFromStringRef("" ))); |
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| 45 | } |
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| 46 | |
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| 47 | #if (SIZE_MAX > UINT32_MAX) && defined(EXPENSIVE_CHECKS) |
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| 48 | TEST(CRCTest, LargeCRC32) { |
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| 49 | // Check that crc32 can handle inputs with sizes larger than 32 bits. |
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| 50 | size_t TestSize = (size_t)UINT32_MAX + 42; |
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| 51 | uint8_t *TestData = (uint8_t*)calloc(TestSize, 1); |
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| 52 | if (!TestData) |
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| 53 | GTEST_SKIP(); |
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| 54 | |
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| 55 | // Test expectation generated with: |
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| 56 | // $ truncate --size=`echo 2^32-1+42 | bc` /tmp/foo |
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| 57 | // $ crc32 /tmp/foo |
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| 58 | EXPECT_EQ(0xE46F28FBU, llvm::crc32(ArrayRef(TestData, TestSize))); |
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| 59 | |
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| 60 | free(TestData); |
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| 61 | } |
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| 62 | #endif |
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| 63 | |
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| 64 | } // end anonymous namespace |
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| 65 | |
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