From ee159bdbdbce293e66d7b9249208f367faff5d81 Mon Sep 17 00:00:00 2001 From: Dave Thaler Date: Tue, 27 Sep 2022 18:59:47 +0000 Subject: 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 --- Documentation/bpf/clang-notes.rst | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'Documentation/bpf/clang-notes.rst') 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 ================= -- cgit v1.2.3-59-g8ed1b