From: Dave Thaler Date: Tue, 27 Sep 2022 18:59:47 +0000 (+0000) Subject: bpf, docs: Add Clang note about BPF_ALU X-Git-Tag: block-6.1-2022-13-10~73^2~10^2~10 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=ee159bdbdbce293e66d7b9249208f367faff5d81;p=linux-block.git bpf, docs: Add Clang note about BPF_ALU Add Clang note about BPF_ALU. Signed-off-by: Dave Thaler Link: https://lore.kernel.org/r/20220927185958.14995-4-dthaler1968@googlemail.com Signed-off-by: Alexei Starovoitov --- diff --git a/Documentation/bpf/clang-notes.rst b/Documentation/bpf/clang-notes.rst index b15179cb5117..528feddf2db9 100644 --- a/Documentation/bpf/clang-notes.rst +++ b/Documentation/bpf/clang-notes.rst @@ -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 =================