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author | Thiago Macieira <thiago.macieira@intel.com> | 2015-12-03 17:37:02 -0800 |
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committer | Thiago Macieira <thiago.macieira@intel.com> | 2015-12-05 00:11:28 +0000 |
commit | f5f47987ce369aa3f7553e6c0da509461a1ddf1a (patch) | |
tree | aa2687fdc9cdfff5756ccbdf28098932277823e6 /src/sql/drivers/mysql/qsql_mysql.cpp | |
parent | 2fb42eb4af3444b11e7b1210323637937ef0b005 (diff) |
qCount{Leading,Trailing}ZeroBits: Use __builtin_clzs for 16-bit
If possible.
The BSF/BSR/TZCNT/LZCNT Intel instruction does not exist for 8-bit. And
it's a good idea to use the 32-bit instruction instead of the 16-bit one
for that case, to avoid the Length Changing Prefix (LCP).
GCC doesn't allow us to use __builtin_cl[tz]s unless BMI is active,
while ICC generates the same code either way (Clang understands
__has_builtin).
Change-Id: I8de47ed6c7be4847b99bffff141c91603c7024dc
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@theqtcompany.com>
Diffstat (limited to 'src/sql/drivers/mysql/qsql_mysql.cpp')
0 files changed, 0 insertions, 0 deletions