You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
55 lines
1.7 KiB
55 lines
1.7 KiB
//===-- checksum.h ----------------------------------------------*- C++ -*-===//
|
|
//
|
|
// 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
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef SCUDO_CHECKSUM_H_
|
|
#define SCUDO_CHECKSUM_H_
|
|
|
|
#include "internal_defs.h"
|
|
|
|
// Hardware CRC32 is supported at compilation via the following:
|
|
// - for i386 & x86_64: -msse4.2
|
|
// - for ARM & AArch64: -march=armv8-a+crc or -mcrc
|
|
// An additional check must be performed at runtime as well to make sure the
|
|
// emitted instructions are valid on the target host.
|
|
|
|
#ifdef __SSE4_2__
|
|
#include <smmintrin.h>
|
|
#define CRC32_INTRINSIC FIRST_32_SECOND_64(_mm_crc32_u32, _mm_crc32_u64)
|
|
#endif
|
|
#ifdef __ARM_FEATURE_CRC32
|
|
#include <arm_acle.h>
|
|
#define CRC32_INTRINSIC FIRST_32_SECOND_64(__crc32cw, __crc32cd)
|
|
#endif
|
|
|
|
namespace scudo {
|
|
|
|
enum class Checksum : u8 {
|
|
BSD = 0,
|
|
HardwareCRC32 = 1,
|
|
};
|
|
|
|
// BSD checksum, unlike a software CRC32, doesn't use any array lookup. We save
|
|
// significantly on memory accesses, as well as 1K of CRC32 table, on platforms
|
|
// that do no support hardware CRC32. The checksum itself is 16-bit, which is at
|
|
// odds with CRC32, but enough for our needs.
|
|
inline u16 computeBSDChecksum(u16 Sum, uptr Data) {
|
|
for (u8 I = 0; I < sizeof(Data); I++) {
|
|
Sum = static_cast<u16>((Sum >> 1) | ((Sum & 1) << 15));
|
|
Sum = static_cast<u16>(Sum + (Data & 0xff));
|
|
Data >>= 8;
|
|
}
|
|
return Sum;
|
|
}
|
|
|
|
bool hasHardwareCRC32();
|
|
WEAK u32 computeHardwareCRC32(u32 Crc, uptr Data);
|
|
|
|
} // namespace scudo
|
|
|
|
#endif // SCUDO_CHECKSUM_H_
|