root/xz
1
0
Fork 0
mirror of https://git.tukaani.org/xz.git synced 2025-04-13 11:10:51 +00:00
Code Issues Releases Wiki Activity

liblzma: Disable CLMUL CRC on old MSVC targeting 32-bit x86

Browse Source 
On GitHub runners, VS 2019 16.11 (MSVC 19.29.30158) results in
test failures. VS 2022 17.13 (MSVC 19.43.34808) works.

In xz 5.6.x there was a #pragma-based workaround for MSVC builds for
32-bit x86. Another method was thought to work with the new rewritten
CLMUL CRC. Apparently it doesn't. Keep it simple and disable CLMUL CRC
with any non-recent MSVC when building for 32-bit x86.

Fixes: 54eaea5ea49b ("liblzma: x86 CLMUL CRC: Rewrite")
Fixes: https://github.com/tukaani-project/xz/issues/171
Reported-by: Andrew Murray
This commit is contained in:
Lasse Collin 2025-04-07 22:36:58 +03:00
parent c5fd88dfc3
commit b5a5d9e3f7
No known key found for this signature in database
GPG Key ID: 38EE757D69184620
1 changed files with 13 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
src/liblzma/check/crc_common.h
View File

@ -134,10 +134,20 @@ extern const uint64_t lzma_crc64_table[4][256];
// 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.
// - The unconditional use doesn't work with MSVC as I don't know
// how to detect the features here.
//
# if (defined(__SSSE3__) && defined(__SSE4_1__) && defined(__PCLMUL__) \
// Don't enable CLMUL at all on old MSVC that targets 32-bit x86.
// There seems to be a compiler bug that produces broken code
// in optimized (Release) builds. It results in crashing tests.
// It is known that VS 2019 16.11 (MSVC 19.29.30158) is broken
// and that VS 2022 17.13 (MSVC 19.43.34808) works.
# if defined(_MSC_FULL_VER) && _MSC_FULL_VER < 194334808 \
&& !defined(__INTEL_COMPILER) && !defined(__clang__) \
&& defined(_M_IX86)
// Old MSVC targeting 32-bit x86: Don't enable CLMUL at all.
# elif (defined(__SSSE3__) && defined(__SSE4_1__) \
&& defined(__PCLMUL__) \
&& !defined(HAVE_CRC_X86_ASM)) \
|| (defined(__e2k__) && __iset__ >= 6)
# define CRC32_ARCH_OPTIMIZED 1