Popcnt instruction can be used to speedup hash computation on processors with POPCNT support.
Signed-off-by: Bhanuprakash Bodireddy <[email protected]> --- Documentation/intro/install/general.rst | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/Documentation/intro/install/general.rst b/Documentation/intro/install/general.rst index 1485bdc..718e5c2 100644 --- a/Documentation/intro/install/general.rst +++ b/Documentation/intro/install/general.rst @@ -265,6 +265,12 @@ intrinsics can be used by passing ``-msse4.2``:: $ ./configure CFLAGS="-g -O2 -msse4.2"` +Also builtin popcnt instruction can be used to speedup the counting of the +bits set in an integer. For example on X86_64 with POPCNT support, it can be +enabled by passing ``-mpopcnt``:: + + $ ./configure CFLAGS="-g -O2 -mpopcnt"` + If you are on a different processor and don't know what flags to choose, it is recommended to use ``-march=native`` settings:: -- 2.4.11 _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
