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liblzma: Tidy up crc_common.h 

Prefix ARM64_RUNTIME_DETECTION with CRC_ and reorder it to be with
the other ARM64-specific lines. That macro isn't used outside this
file.

ARM64 CLMUL implementation doesn't exist yet and thus CRC64_ARM64_CLMUL
isn't used anywhere yet.

It's not ideal that the single-letter CRC utility macros are here
as they pollute the namespace of the LZ encoder files. Those could
be moved their own crc_macros.h like they were in 5.2.x but in practice
this is fine enough already.
This commit is contained in:
Lasse Collin 2024-06-23 15:35:35 +03:00
parent 7484d37538
commit fe77c4e130
1 changed files with 42 additions and 20 deletions
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62
src/liblzma/check/crc_common.h
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@ -3,7 +3,7 @@
///////////////////////////////////////////////////////////////////////////////
//
/// \file crc_common.h
/// \brief Some functions and macros for CRC32 and CRC64
/// \brief Macros and declarations for CRC32 and CRC64
//
// Authors: Lasse Collin
// Ilya Kurdyukov
@ -18,6 +18,10 @@
#include "common.h"
/////////////
// Generic //
/////////////
#ifdef WORDS_BIGENDIAN
# define A(x) ((x) >> 24)
# define B(x) (((x) >> 16) & 0xFF)
@ -56,26 +60,39 @@ extern const uint64_t lzma_crc64_table[4][256];
#endif
// Keep this in sync with changes to crc32_arm64.h
#if defined(_WIN32) || defined(HAVE_GETAUXVAL) \
|| defined(HAVE_ELF_AUX_INFO) \
|| defined(HAVE_CPU_ID_AA64ISAR0) \
|| (defined(__APPLE__) && defined(HAVE_SYSCTLBYNAME))
# define ARM64_RUNTIME_DETECTION 1
#endif
///////////////////
// Configuration //
///////////////////
// NOTE: This config isn't used if HAVE_SMALL is defined!
// These are defined if the generic slicing-by-n implementations and their
// lookup tables are built.
#undef CRC32_GENERIC
#undef CRC64_GENERIC
// These are defined if an arch-specific version is built. If both this
// and matching _GENERIC is defined then runtime detection must be used.
#undef CRC32_ARCH_OPTIMIZED
#undef CRC64_ARCH_OPTIMIZED
// The x86 CLMUL is used for both CRC32 and CRC64.
#undef CRC_X86_CLMUL
// Many ARM64 processor have CRC32 instructions.
// CRC64 could be done with CLMUL but it's not implemented yet.
#undef CRC32_ARM64
#undef CRC64_ARM64_CLMUL
// ARM64
//
// Keep this in sync with changes to crc32_arm64.h
#if defined(_WIN32) || defined(HAVE_GETAUXVAL) \
|| defined(HAVE_ELF_AUX_INFO) \
|| defined(HAVE_CPU_ID_AA64ISAR0) \
|| (defined(__APPLE__) && defined(HAVE_SYSCTLBYNAME))
# define CRC_ARM64_RUNTIME_DETECTION 1
#endif
// ARM64 CRC32 instruction is only useful for CRC32. Currently, only
// little endian is supported since we were unable to test on a big
@ -87,24 +104,26 @@ extern const uint64_t lzma_crc64_table[4][256];
# if defined(__ARM_FEATURE_CRC32)
# define CRC32_ARCH_OPTIMIZED 1
# define CRC32_ARM64 1
# elif defined(ARM64_RUNTIME_DETECTION)
# elif defined(CRC_ARM64_RUNTIME_DETECTION)
# define CRC32_ARCH_OPTIMIZED 1
# define CRC32_ARM64 1
# define CRC32_GENERIC 1
# endif
#endif
// x86 and E2K
#if defined(HAVE_USABLE_CLMUL)
// If CLMUL is allowed unconditionally in the compiler options then the
// generic version and the tables can be omitted. Exceptions:
//
// - If 32-bit x86 assembly files are enabled then those are always
// built and runtime detection is used even if compiler flags
// were set to allow CLMUL unconditionally.
//
// - This doesn't work with MSVC as I don't know how to detect
// the features here.
//
// If CLMUL is allowed unconditionally in the compiler options then
// the generic version and the tables can be omitted. Exceptions:
//
// - If 32-bit x86 assembly files are enabled then those are always
// built and runtime detection is used even if compiler flags
// were set to allow CLMUL unconditionally.
//
// - This doesn't work with MSVC as I don't know how to detect
// the features here.
//
# if (defined(__SSSE3__) && defined(__SSE4_1__) && defined(__PCLMUL__) \
&& !defined(HAVE_CRC_X86_ASM)) \
|| (defined(__e2k__) && __iset__ >= 6)
@ -120,6 +139,9 @@ extern const uint64_t lzma_crc64_table[4][256];
# endif
#endif
// Fallback configuration
//
// For CRC32 use the generic slice-by-eight implementation if no optimized
// version is available.
#if !defined(CRC32_ARCH_OPTIMIZED) && !defined(CRC32_GENERIC)