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path: root/src/liblzma/check/crc_clmul.c (follow)
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2024-01-11liblzma: Avoid extern lzma_crc32_clmul() and lzma_crc64_clmul().Lasse Collin1-369/+0
A CLMUL-only build will have the crcxx_clmul() inlined into lzma_crcxx(). Previously a jump to the extern lzma_crcxx_clmul() was needed. Notes about shared liblzma on ELF platforms: - On platforms that support ifunc and -fvisibility=hidden, this was silly because CLMUL-only build would have that single extra jump instruction of extra overhead. - On platforms that support neither -fvisibility=hidden nor linker version script (liblzma*.map), jumping to lzma_crcxx_clmul() would go via PLT so a few more instructions of overhead (still not a big issue but silly nevertheless). There was a downside with static liblzma too: if an application only needs lzma_crc64(), static linking would make the linker include the CLMUL code for both CRC32 and CRC64 from crc_x86_clmul.o even though the CRC32 code wouldn't be needed, thus increasing code size of the executable (assuming that -ffunction-sections isn't used). Also, now compilers are likely to inline crc_simd_body() even if they don't support the always_inline attribute (or MSVC's __forceinline). Quite possibly all compilers that build the code do support such an attribute. But now it likely isn't a problem even if the attribute wasn't supported. Now all x86-specific stuff is in crc_x86_clmul.h. If other archs The other archs can then have their own headers with their own is_clmul_supported() and crcxx_clmul(). Another bonus is that the build system doesn't need to care if crc_clmul.c is needed. is_clmul_supported() stays as inline function as it's not needed when doing a CLMUL-only build (avoids a warning about unused function).
2024-01-11liblzma: crc_clmul.c: Add crc_attr_target macro.Lasse Collin1-14/+16
This reduces the number of the complex #if directives.
2024-01-11liblzma: Simplify existing cases with lzma_attr_no_sanitize_address.Lasse Collin1-9/+3
2024-01-10liblzma: CRC: Add empty lines.Lasse Collin1-1/+0
And remove one too.
2024-01-10liblzma: crc_clmul.c: Tidy up the location of MSVC pragma.Lasse Collin1-2/+2
It makes no difference in practice.
2023-10-21liblzma: Move is_clmul_supported() back to crc_common.h.Jia Tan1-45/+0
This partially reverts creating crc_clmul.c (8c0f9376f58c0696d5d6719705164d35542dd891) where is_clmul_supported() was moved, extern'ed, and renamed to lzma_is_clmul_supported(). This caused a problem when the function call to lzma_is_clmul_supported() results in a call through the PLT. ifunc resolvers run very early in the dynamic loading sequence, so the PLT may not be setup properly at this point. Whether the PLT is used or not for lzma_is_clmul_supported() depened upon the compiler-toolchain used and flags. In liblzma compiled with GCC, for instance, GCC will go through the PLT for function calls internal to liblzma if the version scripts and symbol visibility hiding are not used. If lazy-binding is disabled, then it would have made any program linked with liblzma fail during dynamic loading in the ifunc resolver.
2023-10-19liblzma: Fix -fsanitize=address failure with crc_clmul functions.Jia Tan1-0/+6
After forcing crc_simd_body() to always be inlined it caused -fsanitize=address to fail for lzma_crc32_clmul() and lzma_crc64_clmul(). The __no_sanitize_address__ attribute was added to lzma_crc32_clmul() and lzma_crc64_clmul(), but not removed from crc_simd_body(). ASAN and inline functions behavior has changed over the years for GCC specifically, so while strictly required we will keep __attribute__((__no_sanitize_address__)) on crc_simd_body() in case this becomes a requirement in the future. Older GCC versions refuse to inline a function with ASAN if the caller and callee do not agree on sanitization flags (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89124#c3). If the function was forced to be inlined, it will not compile if the callee function has __no_sanitize_address__ but the caller doesn't.
2023-10-18liblzma: Set the MSVC optimization fix to only cover lzma_crc64_clmul().Jia Tan1-15/+15
After testing a 32-bit Release build on MSVC, only lzma_crc64_clmul() has the bug. crc_simd_body() and lzma_crc32_clmul() do not need the optimizations disabled.
2023-10-18liblzma: Include common.h in crc_common.h.Lasse Collin1-1/+0
crc_common.h depends on common.h. The headers include common.h except when there is a reason to not do so.
2023-10-18liblzma: Add the crc_always_inline macro to crc_simd_body().Jia Tan1-1/+1
Forcing this to be inline has a significant speed improvement at the cost of a few repeated instructions. The compilers tested on did not inline this function since it is large and is used twice in the same translation unit.
2023-10-18liblzma: Create crc_clmul.c.Jia Tan1-0/+414
Both crc32_clmul() and crc64_clmul() are now exported from crc32_clmul.c as lzma_crc32_clmul() and lzma_crc64_clmul(). This ensures that is_clmul_supported() (now lzma_is_clmul_supported()) is not duplicated between crc32_fast.c and crc64_fast.c. Also, it encapsulates the complexity of the CLMUL implementations into a single file and reduces the complexity of crc32_fast.c and crc64_fast.c. Before, CLMUL code was present in crc32_fast.c, crc64_fast.c, and crc_common.h. During the conversion, various cleanups were applied to code (thanks to Lasse Collin) including: - Require using semicolons with MASK_/L/H/LH macros. - Variable typing and const handling improvements. - Improvements to comments. - Fixes to the pragmas used. - Removed unneeded variables. - Whitespace improvements. - Fixed CRC_USE_GENERIC_FOR_SMALL_INPUTS handling. - Silenced warnings and removed the need for some #pragmas