bpf, docs: Add Clang note about BPF_ALU

Add Clang note about BPF_ALU.

Signed-off-by: Dave Thaler <dthaler@microsoft.com>
Link: https://lore.kernel.org/r/20220927185958.14995-4-dthaler1968@googlemail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Dave Thaler 2022-09-27 18:59:47 +00:00 committed by Alexei Starovoitov
parent 6c7aaffb24
commit ee159bdbdb

View file

@ -14,6 +14,12 @@ Clang defined "CPU" versions, where a CPU version of 3 corresponds to the curren
Clang can select the eBPF ISA version using ``-mcpu=v3`` for example to select version 3.
Arithmetic instructions
=======================
For CPU versions prior to 3, Clang v7.0 and later can enable ``BPF_ALU`` support with
``-Xclang -target-feature -Xclang +alu32``. In CPU version 3, support is automatically included.
Atomic operations
=================