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xz/src/liblzma/check/crc64_fast.c
Lasse Collin c5fd88dfc3
liblzma: Remove MSVC hack from CLMUL CRC
It's not enough with MSVC 19.29 (VS 2019) even if the hack was also
applied to the CRC32 code. The tests crash when built for 32-bit x86.
2025-04-07 22:36:58 +03:00

162 lines
3.4 KiB
C

// SPDX-License-Identifier: 0BSD
///////////////////////////////////////////////////////////////////////////////
//
/// \file crc64.c
/// \brief CRC64 calculation
//
// Authors: Lasse Collin
// Ilya Kurdyukov
//
///////////////////////////////////////////////////////////////////////////////
#include "check.h"
#include "crc_common.h"
#if defined(CRC_X86_CLMUL)
# define BUILDING_CRC_CLMUL 64
# include "crc_x86_clmul.h"
#endif
#ifdef CRC64_GENERIC
/////////////////////////////////
// Generic slice-by-four CRC64 //
/////////////////////////////////
#if defined(WORDS_BIGENDIAN)
# include "crc64_table_be.h"
#else
# include "crc64_table_le.h"
#endif
#ifdef HAVE_CRC_X86_ASM
extern uint64_t lzma_crc64_generic(
const uint8_t *buf, size_t size, uint64_t crc);
#else
#ifdef WORDS_BIGENDIAN
# define A1(x) ((x) >> 56)
#else
# define A1 A
#endif
// See the comments in crc32_fast.c. They aren't duplicated here.
static uint64_t
lzma_crc64_generic(const uint8_t *buf, size_t size, uint64_t crc)
{
crc = ~crc;
#ifdef WORDS_BIGENDIAN
crc = byteswap64(crc);
#endif
if (size > 4) {
while ((uintptr_t)(buf) & 3) {
crc = lzma_crc64_table[0][*buf++ ^ A1(crc)] ^ S8(crc);
--size;
}
const uint8_t *const limit = buf + (size & ~(size_t)(3));
size &= (size_t)(3);
while (buf < limit) {
#ifdef WORDS_BIGENDIAN
const uint32_t tmp = (uint32_t)(crc >> 32)
^ aligned_read32ne(buf);
#else
const uint32_t tmp = (uint32_t)crc
^ aligned_read32ne(buf);
#endif
buf += 4;
crc = lzma_crc64_table[3][A(tmp)]
^ lzma_crc64_table[2][B(tmp)]
^ S32(crc)
^ lzma_crc64_table[1][C(tmp)]
^ lzma_crc64_table[0][D(tmp)];
}
}
while (size-- != 0)
crc = lzma_crc64_table[0][*buf++ ^ A1(crc)] ^ S8(crc);
#ifdef WORDS_BIGENDIAN
crc = byteswap64(crc);
#endif
return ~crc;
}
#endif // HAVE_CRC_X86_ASM
#endif // CRC64_GENERIC
#if defined(CRC64_GENERIC) && defined(CRC64_ARCH_OPTIMIZED)
//////////////////////////
// Function dispatching //
//////////////////////////
// If both the generic and arch-optimized implementations are usable, then
// the function that is used is selected at runtime. See crc32_fast.c.
typedef uint64_t (*crc64_func_type)(
const uint8_t *buf, size_t size, uint64_t crc);
static crc64_func_type
crc64_resolve(void)
{
return is_arch_extension_supported()
? &crc64_arch_optimized : &lzma_crc64_generic;
}
#ifdef HAVE_FUNC_ATTRIBUTE_CONSTRUCTOR
# define CRC64_SET_FUNC_ATTR __attribute__((__constructor__))
static crc64_func_type crc64_func;
#else
# define CRC64_SET_FUNC_ATTR
static uint64_t crc64_dispatch(const uint8_t *buf, size_t size, uint64_t crc);
static crc64_func_type crc64_func = &crc64_dispatch;
#endif
CRC64_SET_FUNC_ATTR
static void
crc64_set_func(void)
{
crc64_func = crc64_resolve();
return;
}
#ifndef HAVE_FUNC_ATTRIBUTE_CONSTRUCTOR
static uint64_t
crc64_dispatch(const uint8_t *buf, size_t size, uint64_t crc)
{
crc64_set_func();
return crc64_func(buf, size, crc);
}
#endif
#endif
extern LZMA_API(uint64_t)
lzma_crc64(const uint8_t *buf, size_t size, uint64_t crc)
{
#if defined(CRC64_GENERIC) && defined(CRC64_ARCH_OPTIMIZED)
return crc64_func(buf, size, crc);
#elif defined(CRC64_ARCH_OPTIMIZED)
// If arch-optimized version is used unconditionally without runtime
// CPU detection then omitting the generic version and its 8 KiB
// lookup table makes the library smaller.
return crc64_arch_optimized(buf, size, crc);
#else
return lzma_crc64_generic(buf, size, crc);
#endif
}