Commit Graph

8 Commits

Author SHA1 Message Date
Lasse Collin 93d144f093 liblzma: CRC: Add empty lines.
And remove one too.
2024-01-10 17:19:03 +02:00
Lasse Collin 0c7e854ffd liblzma: crc_clmul.c: Tidy up the location of MSVC pragma.
It makes no difference in practice.
2024-01-10 17:19:03 +02:00
Jia Tan 988e09f27b liblzma: Move is_clmul_supported() back to crc_common.h.
This partially reverts creating crc_clmul.c
(8c0f9376f5) 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.
2023-10-21 00:01:29 +08:00
Jia Tan c60b25569d liblzma: Fix -fsanitize=address failure with crc_clmul functions.
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.
2023-10-19 01:15:20 +08:00
Jia Tan 1c8884f0af liblzma: Set the MSVC optimization fix to only cover lzma_crc64_clmul().
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.
2023-10-18 23:54:41 +08:00
Lasse Collin 2773538049 liblzma: Include common.h in crc_common.h.
crc_common.h depends on common.h. The headers include common.h except
when there is a reason to not do so.
2023-10-18 23:54:41 +08:00
Jia Tan 40abd88afc liblzma: Add the crc_always_inline macro to crc_simd_body().
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.
2023-10-18 23:54:41 +08:00
Jia Tan 8c0f9376f5 liblzma: Create crc_clmul.c.
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
2023-10-18 23:54:36 +08:00