llvm-project/compiler-rt/lib/scudo/scudo_crc32.h

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[scudo] CRC32 optimizations Summary: This change optimizes several aspects of the checksum used for chunk headers. First, there is no point in checking the weak symbol `computeHardwareCRC32` everytime, it will either be there or not when we start, so check it once during initialization and set the checksum type accordingly. Then, the loading of `HashAlgorithm` for SSE versions (and ARM equivalent) was not optimized out, while not necessary. So I reshuffled that part of the code, which duplicates a tiny bit of code, but ends up in a much cleaner assembly (and faster as we avoid an extraneous load and some calls). The following code is the checksum at the end of `scudoMalloc` for x86_64 with full SSE 4.2, before: ``` mov rax, 0FFFFFFFFFFFFFFh shl r10, 38h mov edi, dword ptr cs:_ZN7__scudoL6CookieE ; __scudo::Cookie and r14, rax lea rsi, [r13-10h] movzx eax, cs:_ZN7__scudoL13HashAlgorithmE ; __scudo::HashAlgorithm or r14, r10 mov rbx, r14 xor bx, bx call _ZN7__scudo20computeHardwareCRC32Ejm ; __scudo::computeHardwareCRC32(uint,ulong) mov rsi, rbx mov edi, eax call _ZN7__scudo20computeHardwareCRC32Ejm ; __scudo::computeHardwareCRC32(uint,ulong) mov r14w, ax mov rax, r13 mov [r13-10h], r14 ``` After: ``` mov rax, cs:_ZN7__scudoL6CookieE ; __scudo::Cookie lea rcx, [rbx-10h] mov rdx, 0FFFFFFFFFFFFFFh and r14, rdx shl r9, 38h or r14, r9 crc32 eax, rcx mov rdx, r14 xor dx, dx mov eax, eax crc32 eax, rdx mov r14w, ax mov rax, rbx mov [rbx-10h], r14 ``` Reviewers: dvyukov, alekseyshl, kcc Reviewed By: alekseyshl Subscribers: aemerson, rengolin, llvm-commits Differential Revision: https://reviews.llvm.org/D32971 llvm-svn: 302538
2017-05-09 23:12:38 +08:00
//===-- scudo_crc32.h -------------------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// Scudo chunk header checksum related definitions.
///
//===----------------------------------------------------------------------===//
#ifndef SCUDO_CRC32_H_
#define SCUDO_CRC32_H_
#include "sanitizer_common/sanitizer_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.
#if defined(__SSE4_2__) || defined(__ARM_FEATURE_CRC32)
# 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
#endif // defined(__SSE4_2__) || defined(__ARM_FEATURE_CRC32)
namespace __scudo {
enum : u8 {
CRC32Software = 0,
CRC32Hardware = 1,
};
static const u32 CRC32Table[] = {
[scudo] CRC32 optimizations Summary: This change optimizes several aspects of the checksum used for chunk headers. First, there is no point in checking the weak symbol `computeHardwareCRC32` everytime, it will either be there or not when we start, so check it once during initialization and set the checksum type accordingly. Then, the loading of `HashAlgorithm` for SSE versions (and ARM equivalent) was not optimized out, while not necessary. So I reshuffled that part of the code, which duplicates a tiny bit of code, but ends up in a much cleaner assembly (and faster as we avoid an extraneous load and some calls). The following code is the checksum at the end of `scudoMalloc` for x86_64 with full SSE 4.2, before: ``` mov rax, 0FFFFFFFFFFFFFFh shl r10, 38h mov edi, dword ptr cs:_ZN7__scudoL6CookieE ; __scudo::Cookie and r14, rax lea rsi, [r13-10h] movzx eax, cs:_ZN7__scudoL13HashAlgorithmE ; __scudo::HashAlgorithm or r14, r10 mov rbx, r14 xor bx, bx call _ZN7__scudo20computeHardwareCRC32Ejm ; __scudo::computeHardwareCRC32(uint,ulong) mov rsi, rbx mov edi, eax call _ZN7__scudo20computeHardwareCRC32Ejm ; __scudo::computeHardwareCRC32(uint,ulong) mov r14w, ax mov rax, r13 mov [r13-10h], r14 ``` After: ``` mov rax, cs:_ZN7__scudoL6CookieE ; __scudo::Cookie lea rcx, [rbx-10h] mov rdx, 0FFFFFFFFFFFFFFh and r14, rdx shl r9, 38h or r14, r9 crc32 eax, rcx mov rdx, r14 xor dx, dx mov eax, eax crc32 eax, rdx mov r14w, ax mov rax, rbx mov [rbx-10h], r14 ``` Reviewers: dvyukov, alekseyshl, kcc Reviewed By: alekseyshl Subscribers: aemerson, rengolin, llvm-commits Differential Revision: https://reviews.llvm.org/D32971 llvm-svn: 302538
2017-05-09 23:12:38 +08:00
0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2,
0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c,
0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423,
0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106,
0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d,
0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7,
0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa,
0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84,
0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e,
0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55,
0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28,
0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f,
0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69,
0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc,
0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693,
0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
};
INLINE u32 computeSoftwareCRC32(u32 Crc, uptr Data) {
for (uptr i = 0; i < sizeof(Data); i++) {
Crc = CRC32Table[(Crc ^ Data) & 0xff] ^ (Crc >> 8);
Data >>= 8;
}
return Crc;
}
SANITIZER_WEAK_ATTRIBUTE u32 computeHardwareCRC32(u32 Crc, uptr Data);
} // namespace __scudo
#endif // SCUDO_CRC32_H_