diff options
| author | Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com> | 2020-03-26 13:13:31 +1100 |
|---|---|---|
| committer | Anel Husakovic <anel@mariadb.org> | 2020-04-02 07:31:27 +0200 |
| commit | cc5462567487054f47b380062f4303f83c902b66 (patch) | |
| tree | 8a1dc986ccd72fc04f4ace57b4dd4c756839b9ab | |
| parent | b40b3720cbba133ee76ef336bf89bbf5c03ac403 (diff) | |
| download | mariadb-git-bb-10.3-anel-PR1477.tar.gz | |
MDEV-21984: POWER crc32 acceleration - fix clang's behavior on versions >= 7bb-10.3-anel-PR1477
Clang 7 changed the behavior of vec_xxpermdi in order to match GCC's
behavior. After this change, code that used to work on Clang 6 stopped
to work on Clang >= 7.
Tested on Clang 6, 7, 8 and 9.
Reference: https://bugs.llvm.org/show_bug.cgi?id=38192
Upstream fix: https://github.com/antonblanchard/crc32-vpmsum/commit/361aaf77a599995e23acd50c9c50d48d30c69241
PR 1477
| -rw-r--r-- | extra/crc32-vpmsum/clang_workaround.h | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/extra/crc32-vpmsum/clang_workaround.h b/extra/crc32-vpmsum/clang_workaround.h index b5e7dae011c..915f7e5282f 100644 --- a/extra/crc32-vpmsum/clang_workaround.h +++ b/extra/crc32-vpmsum/clang_workaround.h @@ -39,7 +39,12 @@ __vector unsigned long long __builtin_pack_vector (unsigned long __a, return __v; } -#ifndef vec_xxpermdi +/* + * Clang 7 changed the behavior of vec_xxpermdi in order to provide the same + * behavior of GCC. That means code adapted to Clang >= 7 does not work on + * Clang <= 6. So, fallback to __builtin_unpack_vector() on Clang <= 6. + */ +#if !defined vec_xxpermdi || __clang_major__ <= 6 static inline unsigned long __builtin_unpack_vector (__vector unsigned long long __v, @@ -62,9 +67,9 @@ static inline unsigned long __builtin_unpack_vector_0 (__vector unsigned long long __v) { #if defined(__BIG_ENDIAN__) - return vec_xxpermdi(__v, __v, 0x0)[1]; - #else return vec_xxpermdi(__v, __v, 0x0)[0]; + #else + return vec_xxpermdi(__v, __v, 0x3)[0]; #endif } @@ -72,9 +77,9 @@ static inline unsigned long __builtin_unpack_vector_1 (__vector unsigned long long __v) { #if defined(__BIG_ENDIAN__) - return vec_xxpermdi(__v, __v, 0x3)[1]; - #else return vec_xxpermdi(__v, __v, 0x3)[0]; + #else + return vec_xxpermdi(__v, __v, 0x0)[0]; #endif } #endif /* vec_xxpermdi */ |