diff options
| author | Boris Kolpackov <boris@codesynthesis.com> | 2021-03-12 16:07:07 +0200 |
|---|---|---|
| committer | Boris Kolpackov <boris@codesynthesis.com> | 2021-03-12 16:07:07 +0200 |
| commit | 5956bce9b873b8cd481cb40cddef1bda882f5a3f (patch) | |
| tree | eae05187ee6f06f5c74f2784d8def38888a74ff3 | |
| parent | f4cd7abdd38aa3d14dcce98cb92dc1054fe97503 (diff) | |
Disable use of _tzcnt_u64() in lz4.c for Clang targeting MSVC version 9
| -rw-r--r-- | libbutl/lz4.cxx | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/libbutl/lz4.cxx b/libbutl/lz4.cxx index a69c9ad..6a91a12 100644 --- a/libbutl/lz4.cxx +++ b/libbutl/lz4.cxx @@ -396,9 +396,12 @@ namespace butl #define XXH_PRIVATE_API // Makes API static and includes xxhash.c. #include "xxhash.h" -// Clang 8 targeting MSVC does not have _tzcnt_u64(). +// Clang targeting MSVC prior to version 10 has difficulty with _tzcnt_u64() +// (see Clang bug 47099 for a potentially related issue). Including relevant +// headers (<immintrin.h>, <intrin.h>) does not appear to help. So for now we +// just disable the use of _tzcnt_u64(). // -#if defined(_MSC_VER) && defined(__clang__) && __clang_major__ <= 8 +#if defined(_MSC_VER) && defined(__clang__) && __clang_major__ < 10 # define LZ4_FORCE_SW_BITCOUNT #endif |